TANGLE: Two-Level Support Vector Regression Approach for Protein Backbone Torsion Angle Prediction from Primary Sequences

PubMed Central

Song, Jiangning; Tan, Hao; Wang, Mingjun; Webb, Geoffrey I.; Akutsu, Tatsuya

2012-01-01

Protein backbone torsion angles (Phi) and (Psi) involve two rotation angles rotating around the Cα-N bond (Phi) and the Cα-C bond (Psi). Due to the planarity of the linked rigid peptide bonds, these two angles can essentially determine the backbone geometry of proteins. Accordingly, the accurate prediction of protein backbone torsion angle from sequence information can assist the prediction of protein structures. In this study, we develop a new approach called TANGLE (Torsion ANGLE predictor) to predict the protein backbone torsion angles from amino acid sequences. TANGLE uses a two-level support vector regression approach to perform real-value torsion angle prediction using a variety of features derived from amino acid sequences, including the evolutionary profiles in the form of position-specific scoring matrices, predicted secondary structure, solvent accessibility and natively disordered region as well as other global sequence features. When evaluated based on a large benchmark dataset of 1,526 non-homologous proteins, the mean absolute errors (MAEs) of the Phi and Psi angle prediction are 27.8° and 44.6°, respectively, which are 1% and 3% respectively lower than that using one of the state-of-the-art prediction tools ANGLOR. Moreover, the prediction of TANGLE is significantly better than a random predictor that was built on the amino acid-specific basis, with the p-value<1.46e-147 and 7.97e-150, respectively by the Wilcoxon signed rank test. As a complementary approach to the current torsion angle prediction algorithms, TANGLE should prove useful in predicting protein structural properties and assisting protein fold recognition by applying the predicted torsion angles as useful restraints. TANGLE is freely accessible at http://sunflower.kuicr.kyoto-u.ac.jp/~sjn/TANGLE/. PMID:22319565

Heteroclinic tangle phenomena in nanomagnets subject to time-harmonic excitations

NASA Astrophysics Data System (ADS)

Serpico, C.; Quercia, A.; Bertotti, G.; d'Aquino, M.; Mayergoyz, I.; Perna, S.; Ansalone, P.

2015-05-01

Magnetization dynamics in uniformly magnetized nanomagnets excited by time-harmonic (AC) external fields or spin-polarized injected currents is considered. The analysis is focused on the behaviour of the AC-excited dynamics near saddle equilibria. It turns out that this dynamics has a chaotic character at moderately low power level. This chaotic and fractal nature is due to the phenomenon of heteroclinic tangle which is produced by the combined effect of AC-excitations and saddle type dynamics. By using the perturbation technique based on Melnikov function, analytical formulas for the threshold AC excitation amplitudes necessary to create the heteroclinic tangle are derived. Both the cases of AC applied fields and AC spin-polarized injected currents are treated. Then, by means of numerical simulations, we show how heteroclinic tangle is accompanied by the erosion of the safe basin around the stable regimes.

Discursive Psychology and Educational Technology: Beyond the Cognitive Revolution

ERIC Educational Resources Information Center

Friesen, Norm

2009-01-01

As an alternative to dominant cognitive-constructivist approaches to educational technology, this article makes the case for what has been termed a discursive, or postcognitive, psychological research paradigm. It does so by adapting discursive psychological analyses of conversational activity to the study of educational technology use. It applies…

Power/Knowledge: The Discursive Construction of an Author

ERIC Educational Resources Information Center

Olsson, Michael

2007-01-01

This article reports the findings of a study examining the social/discursive construction of an author (Brenda Dervin) by an international community of researchers (information behavior researchers). A crucial conceptual starting point for the study was Michel Foucault's work on the discursive construction of power/knowledge. The study represents…

Language, Metaphor, and Creativity in Discursive Prose.

ERIC Educational Resources Information Center

Ross, William T.

1978-01-01

Traces the denigration of discursive prose back through the "New Criticism" to Romanticism and Samuel Taylor Coleridge, who saw poetry as special and separate from other rhetoric. Notes that discursive prose can be just as creative and interesting as poetry. Urges composition teachers to shift their point of view accordingly. (RL)

Interaction of Neuritic Plaques and Education Predicts Dementia

PubMed Central

Roe, Catherine M.; Xiong, Chengjie; Miller, J. Phillip; Cairns, Nigel J.; Morris, John C.

2009-01-01

In exploring the cognitive reserve hypothesis in persons with substantial Alzheimer disease neuropathology, we aimed to determine the extent to which educational attainment and densities of diffuse plaques, neuritic plaques, and neurofibrillary tangles predict dementia. Participants were 1563 individuals aged 65 years or above who were assessed for dementia within 1 year of death. Generalized linear mixed models were used to examine whether education and density ratings of diffuse plaques and neuritic plaques, and neurofibrillary tangle stage were associated with a dementia diagnosis. Education interacted with densities of neuritic plaques to predict dementia. Tangle density independently predicted dementia, but did not interact with education. Diffuse plaque density was unrelated to dementia when adjusted for densities of neuritic plaques and tangles. Among individuals with Alzheimer disease neuropathology, educational attainment, as a surrogate of cognitive reserve, modifies the influence of neuritic, but not diffuse, plaque neuropathology on the expression of dementia. PMID:18525294

Formation of the Foreign Language Discursive Competence of Pedagogical Faculties Students in the Process of Intercultural Dialogue

ERIC Educational Resources Information Center

Ponomarenko, Larisa N.; Zlobina, Irina S.; Galitskih, Elena O.; Rublyova, Olga S.

2017-01-01

The article presents the main ideas of concept of foreign language discursive competence formation among university and secondary school students by means of intercultural dialogue. The concept includes fundamental principles, activity stages of educational process, and criteria of foreign language discursive competence formation. Innovation of…

Discursive Hierarchical Patterning in Economics Cases

ERIC Educational Resources Information Center

Lung, Jane

2011-01-01

This paper attempts to apply Lung's (2008) model of the discursive hierarchical patterning of cases to a closer and more specific study of Economics cases and proposes a model of the distinct discursive hierarchical patterning of the same. It examines a corpus of 150 Economics cases with a view to uncovering the patterns of discourse construction.…

Fonctions Discursives et Communication Ecrite (Discursive Functions and Written Communication). Melanges Pedagogiques, 1974.

ERIC Educational Resources Information Center

Duda, R.

This article describes discursive functions in the three major areas of non-literary written communication: (1) official or personal correspondence; (2) technical reading or editing; and (3) the press. Illocutionary acts are examined under their three aspects: graphic, lexical, enunciative. This description is intended to result in training…

Communicating Organizational Change Reactions: Downsizing Survivors' Discursive Constructions of Flexible Identities

ERIC Educational Resources Information Center

Aggerholm, Helle Kryger

2014-01-01

The aim of this article is to study employees' discursive construction of disparate survivor responses. The analysis reveals how employees position themselves simultaneously within different types of categories by use of discursive actions. Drawing on various discourses, the actors reject having one solid core of identity and instead signal the…

Struggling to care: A discursive-material analysis of negotiating agency among HIV-positive MSM.

PubMed

Canoy, Nico A; Ofreneo, Mira Alexis P

2017-11-01

A discursive-materialist framework of agency asserts the mutual constitution of agency within cultural discursive, economic, and embodied material structures. Understanding how HIV-positive men who have sex with men in the Philippines negotiate agency vis-a-vis wider social structures, we utilized Foucault's care of the self to locate agency in relationships with the self, others, and the broader world. Using data from narratives of 20 Filipino HIV-positive men who have sex with men, we analyzed the negotiation of agency as HIV-positive as embedded in the unique discursive terrain of Roman Catholicism and the economic materiality of a developing country. Three main processes of negotiating agency are elaborated: (1) questioning the spiritual self and the sexual body in the relationship with the self, (2) navigating interpersonal limits to care giving in the relationship with others, and (3) reclaiming human dignity in health care in the relationship with the broader world. Theoretical insights on the discursive and material constitution of healing in light of discursive and material challenges are discussed.

Imagine: towards an integrated and applied social psychology.

PubMed

Abell, Jackie; Walton, Chris

2010-12-01

This commentary does not aim to engage with the epistemological and ontological technicalities of the discursive psychology maintained by epistemological constructionism and discursive psychology reliant on ontological constructionism approaches that form the basis of the two papers under discussion; other commentators, both in this issue and in the future, are likely to do that. Instead, this commentary aims to situate both papers within a broader frame of contemporary, primarily British social psychology, to ponder the circumstances that gave rise to them and their implications for social psychologists, discursive and non-discursive, alike. We have organized this commentary into two parts. The first part considers two simple questions. First, why does Corcoran critique DPEC for failing to do things that other discursive approaches provide for? And, second, why does Corcoran take DPEC research to task for having too little potential for or made too little contribution to improving the lives and subjectivities of people in general? These two questions are not unrelated, but for clarity's sake we will try to answer them separately. The second part of this commentary will consider the influence of discursive psychology on social psychology more generally.

Selective Neurodegeneration, Without Neurofibrillary Tangles, in a Mouse Model of Niemann-Pick C Disease

PubMed Central

German, Dwight C.; Quintero, E. Matthew; Liang, Chang-Lin; Ng, Benton; Punia, Surender; Xie, Chonglun; Dietschy, John M.

2012-01-01

The BALB/c mouse model of Niemann-Pick type C (NPC) disease exhibits neuropathological similarities to the human condition. There is an age-related cerebral atrophy, demyelination of the corpus callosum, and degeneration of cerebellar Purkinje cells in the NPC mouse. In human NPC, many cortical and subcortical neurons contain neurofibrillary tangles, which are thought by some investigators to play an important role in the neurodegenerative process. The purpose of the present study was to determine whether neurodegeneration occurs in the NPC mouse, in brain regions other than the cerebellum and whether the degeneration is related to the presence of neurofibrillary tangles. Using light microscopic methods with immunohistochemistry, electron microscopy, and cell counting methods, 11-week-old NPC+/+ and NPC−/− animals were examined. In the NPC−/− mice, there were 96% fewer Purkinje cells, 28% fewer neurons in the prefrontal cortex, 20% fewer neurons in the thalamus, and 63% fewer glial cells in the corpus callosum. On the other hand, previous studies indicate normal numbers of neurons and glial cells in these same neuroanatomical regions in young NPC−/− mice. There were normal numbers of cholinergic neurons in sections assessed in the striatum and basal forebrain in the 11-week-old animals and no evidence of neurofibrillary tangles within cells. The present data indicate that both neurons and glial cells die in the NPC mouse but that all cells are not equally vulnerable. There was no evidence for neurofibrillary tangles in the NPC mouse, and therefore the degenerative process in the mouse is unrelated to the neurofibrillary tangle. PMID:11298365

Reconnection Dynamics and Mutual Friction in Quantum Turbulence

NASA Astrophysics Data System (ADS)

Laurie, Jason; Baggaley, Andrew W.

2015-07-01

We investigate the behaviour of the mutual friction force in finite temperature quantum turbulence in He, paying particular attention to the role of quantized vortex reconnections. Through the use of the vortex filament model, we produce three experimentally relevant types of vortex tangles in steady-state conditions, and examine through statistical analysis, how local properties of the tangle influence the mutual friction force. Finally, by monitoring reconnection events, we present evidence to indicate that vortex reconnections are the dominant mechanism for producing areas of high curvature and velocity leading to regions of high mutual friction, particularly for homogeneous and isotropic vortex tangles.

Protease inhibitors and indoleamines selectively inhibit cholinesterases in the histopathologic structures of Alzheimer disease.

PubMed Central

Wright, C I; Guela, C; Mesulam, M M

1993-01-01

Neurofibrillary tangles and amyloid plaques express acetylcholinesterase and butyrylcholinesterase activity in Alzheimer disease. We previously reported that traditional acetylcholinesterase inhibitors such as BW284C51, tacrine, and physostigmine were more potent inhibitors of the acetylcholinesterase in normal axons and cell bodies than of the acetylcholinesterase in plaques and tangles. We now report that the reverse pattern is seen with indoleamines (such as serotonin and its precursor 5-hydroxytryptophan), carboxypeptidase inhibitor, and the nonspecific protease inhibitor bacitracin. These substances are more potent inhibitors of the cholinesterases in plaques and tangles than of those in normal axons and cell bodies. These results show that the enzymatic properties of plaque and tangle-associated cholinesterases diverge from those of normal axons and cell bodies. The selective susceptibility to bacitracin and carboxypeptidase inhibitor indicates that the catalytic sites of plaque and tangle-bound cholinesterases are more closely associated with peptidase or protease-like properties than the catalytic sites of cholinesterases in normal axons and cell bodies. This shift in enzymatic affinity may lead to the abnormal protein processing that is thought to play a major role in the pathogenesis of Alzheimer disease. The availability of pharmacological and dietary means for altering brain indoleamines raises therapeutic possibilities for inhibiting the abnormal cholinesterase activity associated with Alzheimer disease. Images PMID:8421706

Second nature.

PubMed

Corcoran, Tim

2009-06-01

Are ontological meanings somehow sacrosanct in arguments concerning psychology - particularly those scored by discursive accounts of human being? Or is the purposeful deferment of ontological concerns in discursive psychology (DP) another instance of method-fetishism (Koch, 1981)? Shotter's (1995) understanding of joint action and Chouliaraki's (2002) critical realist account of social action combine to support an alternate position to the predominant discursive psychological approach informed by epistemological constructionism (DPEC). The DPEC position is here contrasted with a discursive psychological approach informed by ontological constructionism (DPOC). Via this distinction, a path for future discursive psychological studies is charted, one which values understanding the kinds of practical-moral knowledges (Shotter, 1993) available to people in accounting for themselves and their actions as psychosocial agents. Contrary to claims that the DPEC/DPOC distinction is supercilious (Edley, 2001) or oxymoronic (Drewery, 2000), the importance of debating what ontology can mean for psychology is herein seen as central to the pursuit of personal, relational and collective wellness in contemporary life.

Scientific Literacy and Discursive Identity: A Theoretical Framework for Understanding Science Learning

ERIC Educational Resources Information Center

Brown, Bryan A.; Reveles, John M.; Kelly, Gregory J.

2005-01-01

In this paper we propose the construct of discursive identity as a way to examine student discourse. We drew from the work of Gee (2001, Review of Research in Education, 25, 99-125) and Nasir and Saxe (2003, Educational Researcher, 32(5), 14-18) to consider the multiple contexts and developmental timescales of student discursive identity…

Reification in the Learning of Square Roots in a Ninth Grade Classroom: Combining Semiotic and Discursive Approaches

ERIC Educational Resources Information Center

Shinno, Yusuke

2018-01-01

This paper reports on combining semiotic and discursive approaches to reification in classroom interactions. It focuses on the discursive characteristics and semiotic processes involved in the teaching and learning of square roots in a ninth grade classroom in Japan. The purpose of this study is to characterize the development of mathematical…

"But at School … I Became a Bit Shy": Korean Immigrant Adolescents' Discursive Participation in Science Classrooms

ERIC Educational Resources Information Center

Ryu, Minjung

2013-01-01

In reform-based science curricula, students' discursive participation is highly encouraged as a means of science learning as well as a goal of science education. However, Asian immigrant students are perceived to be quiet and passive in classroom discursive situations, and this reticence implies that they may face challenges in discourse-rich…

A new TAO kinase inhibitor reduces tau phosphorylation at sites associated with neurodegeneration in human tauopathies.

PubMed

Giacomini, Caterina; Koo, Chuay-Yeng; Yankova, Natalia; Tavares, Ignatius A; Wray, Selina; Noble, Wendy; Hanger, Diane P; Morris, Jonathan D H

2018-05-07

In Alzheimer's disease (AD) and related tauopathies, the microtubule-associated protein tau is highly phosphorylated and aggregates to form neurofibrillary tangles that are characteristic of these neurodegenerative diseases. Our previous work has demonstrated that the thousand-and-one amino acid kinases (TAOKs) 1 and 2 phosphorylate tau on more than 40 residues in vitro. Here we show that TAOKs are phosphorylated and active in AD brain sections displaying mild (Braak stage II), intermediate (Braak stage IV) and advanced (Braak stage VI) tau pathology and that active TAOKs co-localise with both pre-tangle and tangle structures. TAOK activity is also enriched in pathological tau containing sarkosyl-insoluble extracts prepared from AD brain. Two new phosphorylated tau residues (T123 and T427) were identified in AD brain, which appear to be targeted specifically by TAOKs. A new small molecule TAOK inhibitor (Compound 43) reduced tau phosphorylation on T123 and T427 and also on additional pathological sites (S262/S356 and S202/T205/S208) in vitro and in cell models. The TAOK inhibitor also decreased tau phosphorylation in differentiated primary cortical neurons without affecting markers of synapse and neuron health. Notably, TAOK activity also co-localised with tangles in post-mortem frontotemporal lobar degeneration (FTLD) brain tissue. Furthermore, the TAOK inhibitor decreased tau phosphorylation in induced pluripotent stem cell derived neurons from FTLD patients, as well as cortical neurons from a transgenic mouse model of tauopathy (Tau35 mice). Our results demonstrate that abnormal TAOK activity is present at pre-tangles and tangles in tauopathies and that TAOK inhibition effectively decreases tau phosphorylation on pathological sites. Thus, TAOKs may represent a novel target to reduce or prevent tau-associated neurodegeneration in tauopathies.

Molecular and Genetic Investigation of Tau in Chronic Traumatic Encephalopthy

DTIC Science & Technology

2016-10-01

Very wide blood vessels, but no gliosis, macrophages, or tangles. 6 Controls Heavy retraction around vessels and high amounts of cell shrinkage...neocortical pyramidal neuron. (B) This neuron contains a mature intracellular tangle. (C) In the white matter, scattered small granular retraction balls

Stability of knotted vortices in wave chaos

NASA Astrophysics Data System (ADS)

Taylor, Alexander; Dennis, Mark

Large scale tangles of disordered filaments occur in many diverse physical systems, from turbulent superfluids to optical volume speckle to liquid crystal phases. They can exhibit particular large scale random statistics despite very different local physics. We have previously used the topological statistics of knotting and linking to characterise the large scale tangling, using the vortices of three-dimensional wave chaos as a universal model system whose physical lengthscales are set only by the wavelength. Unlike geometrical quantities, the statistics of knotting depend strongly on the physical system and boundary conditions. Although knotting patterns characterise different systems, the topology of vortices is highly unstable to perturbation, under which they may reconnect with one another. In systems of constructed knots, these reconnections generally rapidly destroy the knot, but for vortex tangles the topological statistics must be stable. Using large scale simulations of chaotic eigenfunctions, we numerically investigate the prevalence and impact of reconnection events, and their effect on the topology of the tangle.

Alzheimer's disease: neuritic plaques and neurofibrillary tangles in human brain identified by FTIR spectroscopy

NASA Astrophysics Data System (ADS)

Choo, Lin-P'ing; Jackson, Michael; Halliday, William C.; Mantsch, Henry H.

1994-01-01

The abnormal abundance of (beta) -amyloid plaques and neurofibrillary tangles are the hallmark of Alzheimer's disease (AD). Human central nervous system (CNS) grey matter was probed for characteristics arising from these pathological features. In AD but not normal grey matter, an IR band at 1615 cm-1 is seen, characteristic of a protein in an aggregated state. We speculate that this band arises from (beta) A4-amyloid protein. AD, and 18q- grey matter spectra show increased intensity of phosphate bands in accordance with known hyperphosphorylation of proteins found in neurofibrillary tangles. These spectral features may be useful in the diagnosis of AD.

Preservice elementary teachers' use of a discursive model of meaning making in the co-construction of science understanding

NASA Astrophysics Data System (ADS)

Boyer, Elisebeth C.

This research investigates how three preservice elementary teachers were prepared to teach science using a Discursive Model of Meaning Making. The research is divided into two parts. The first consists of the nature of the participants’ learning experiences in a science methods course within a school-university Professional Development School partnership. This part of the investigation used Constant Comparative Analysis of field notes gathered through participant observation of the methods course. The analysis investigated how the methods instructors employed productive questioning, talk moves, and a coherent research based Teaching Science as Argument Framework. The second part of the study consisted of an investigation into how the participants applied what they experienced during the methods course in their initial science teaching experiences, as well as how the participants made sense of their initial science teaching. Data consisted of teaching videos of the participants during their initial science teaching experiences and self-analysis videos created by the participants. This part of the research used Discourse Analysis of the teaching and self-analysis videos. These inquiries provide insight into what aspects of the methods course were taken up by the participants and how they made sense of their practices. Findings are: 1) Throughout the methods course, instructors modeled how the Teaching Science as Argument Framework can be used to negotiate scientific understanding by employing a Discursive Model of Meaning Making. 2) During lesson plan conferences the Discursive Model was emphasized as participants planned classroom discussion and explored possible student responses enabling them to anticipate how they could attempt to increase student understanding. 3) Participants displayed three distinct patterns of adoption of the Teaching Science as Argument Framework (TSAF), involving different discursive practices. They were, • Detached Discursive Approach: Use of some discursive strategies without an apparent connection to the TSAF. • Connected Approach with a Focus on Student Thinking: Intentional use of the Discursive Model informed by aspects of the TSAF. • TSAF Approach: Priority is given to the TSAF supported by substantial application of the Discursive Model. 4) The evidence participants chose to highlight in their self-analysis videos is reflective of their patterns of adoption of the Teaching Science as Argument Framework and their differing discursive practices. Analysis led to the formation of the middle theory that when learning to teach science in the elementary school, teacher commitment to the discourse and practices of science is constructed through participation in a learning community where a discursive model of meaning making is the norm. Curricular and methodological implications, as well as implications for future research are presented.

Academic Careers and the Valuation of Academics. A Discursive Perspective on Status Categories and Academic Salaries in France as Compared to the U.S., Germany and Great Britain

ERIC Educational Resources Information Center

Angermuller, Johannes

2017-01-01

Academic careers are social processes which involve many members of large populations over long periods of time. This paper outlines a discursive perspective which looks into how academics are categorized in academic systems. From a discursive view, academic careers are organized by categories which can define who academics are (subjectivation)…

The American Society's Constructed Image of Deaf People as Drawn from Discursive Constructions of Deaf People in Major U.S. Newspaper Articles on Cochlear Implantation

ERIC Educational Resources Information Center

Fleischer, Flavia Samella

2011-01-01

This study will explore the constructed image of deaf people in the American society as drawn through analyses of discursive structures in articles on cochlear implantation in major U.S. newspapers published between 2006-2009. To analyze discursive structures of newspaper articles, the approach of Critical Discourse Analysis (CDA) will be…

Applying discursive approaches to health psychology.

PubMed

Seymour-Smith, Sarah

2015-04-01

The aim of this paper is to outline the contribution of two strands of discursive research, glossed as 'macro' and 'micro,' to the field of health psychology. A further goal is to highlight some contemporary debates in methodology associated with the use of interview data versus more naturalistic data in qualitative health research. Discursive approaches provide a way of analyzing talk as a social practice that considers how descriptions are put together and what actions they achieve. A selection of recent examples of discursive research from one applied area of health psychology, studies of diet and obesity, are drawn upon in order to illustrate the specifics of both strands. 'Macro' discourse work in psychology incorporates a Foucauldian focus on the way that discourses regulate subjectivities, whereas the concept of interpretative repertoires affords more agency to the individual: both are useful for identifying the cultural context of talk. Both 'macro' and 'micro' strands focus on accountability to varying degrees. 'Micro' Discursive Psychology, however, pays closer attention to the sequential organization of constructions and focuses on naturalistic settings that allow for the inclusion of an analysis of the health professional. Diets are typically depicted as an individual responsibility in mainstream health psychology, but discursive research highlights how discourses are collectively produced and bound up with social practices. (c) 2015 APA, all rights reserved).

Tangled Threads: Mentoring within a Community of Practice

ERIC Educational Resources Information Center

Tarr, Patricia

2010-01-01

Tangled Threads, a case study of a group of women art educators, examines the nature of mentoring relationships within the context of a professional association. Grounded in literature on "community of practice," relational and peer mentoring, and an ethic of care, the study uncovers the complex interconnections between women's professional and…

Narrating sexual identities in Kenya: "Choice," value, and visibility.

PubMed

Zingsheim, Jason; Goltz, Dustin Bradley; Murphy, Alexandra G; Mastin, Teresa

2017-04-03

This article examines the discursive construction of female same-sex sexual identities in Nairobi. We identify the discursive forces of "choice," devaluation, and invisibility as influential within Kenyan media representations of lesbian, gay, bisexual, transgender, and intersex citizens. Using creative focus groups and participant observation, we demonstrate how same-sex attracted women in Nairobi resist and rearticulate these discursive forces to assert their identity and agency as individuals and as a queer community.

Scientific literacy and discursive identity: A theoretical framework for understanding science learning

NASA Astrophysics Data System (ADS)

Brown, Bryan A.; Reveles, John M.; Kelly, Gregory J.

2005-09-01

In this paper we propose the construct of discursive identity as a way to examine student discourse. We drew from the work of Gee (2001, Review of Research in Education, 25, 99-125) and Nasir and Saxe (2003, Educational Researcher, 32(5), 14-18) to consider the multiple contexts and developmental timescales of student discursive identity development. We argue that theories of scientific literacy need to consider the sociocultural contexts of language use in order to examine fully affiliation and alienation associated with appropriation of scientific discourse. As an illustrative case, we apply discursive identity to series of short exchanges in a fifth-grade classroom of African-American students. The discussion examines potential co-construction of student identity and scientific literacy.

Neuropil threads occur in dendrites of tangle-bearing nerve cells.

PubMed

Braak, H; Braak, E

1988-01-01

Transparent Golgi preparations counterstained for Alzheimer's neurofibrillary changes rendered possible the demonstration of neuropil threads in defined cellular processes. Only dendrites of tangle-bearing cortical nerve cells were found to contain neuropil threads. Processes of glial cells as well as axons present in the material were devoid of neuropil threads.

Tangled Narratives and Wicked Problems: A Complex Case of Positioning and Politics in a Diverse School Community

ERIC Educational Resources Information Center

Nguyen, Thu Suong Thi; Scribner, Samantha M. Paredes; Crow, Gary M.

2012-01-01

The case of Allen Elementary School presents tangled narratives and wicked problems describing the multidimensionality of school community work. Using multiple converging and diverging vignettes, the case points to the distinctiveness of individual experience in schools; the ways institutionalized organizational narratives become cultural…

Principal Facts for 463 Gravity Stations in the Vicinity of Tangle Lakes, East-Central Alaska

USGS Publications Warehouse

Morin, Robert L.; Glen, Jonathan M.G.

2002-01-01

During the summer of 2001, a gravity survey was conducted in the vicinity of Tangle Lakes, east-central Alaska. Measurements of 87 gravity stations were made. The Tangle Lakes area is located about 25 km west of Paxson and north of the Denali Highway. The gravity survey is located on the southwest corner of the Mt. Hayes and the northwest corner of the Gulkana 1:250,000 scale USGS topographic maps. The boundaries of the study area are 62 deg 30' to 63 deg 30' N. latitude and 145 deg 30' to 147 deg 00' W. longitude. A map showing the location of the study area is shown in figure 1. One gravity base station was used for control for this survey. This base station, TLIN is located at the Tangle Lakes Inn. The observed gravity of this station was calculated based on multiple ties to base stations ANCU in Anchorage, PALH in Palmer, BD27 in Gulkana, and base stations D42, and D57 along the Denali Highway.

Symplectic homoclinic tangles of the ideal separatrix of the DIII-D from type I ELMs

NASA Astrophysics Data System (ADS)

Punjabi, Alkesh; Ali, Halima

2012-10-01

The ideal separatrix of the divertor tokamaks is a degenerate manifold where both the stable and unstable manifolds coincide. Non-axisymmetric magnetic perturbations remove the degeneracy; and split the separatrix manifold. This creates an extremely complex topological structure, called homoclinic tangles. The unstable manifold intersects the stable manifold and creates alternating inner and outer lobes at successive homoclinic points. The Hamiltonian system must preserve the symplectic topological invariance, and this controls the size and radial extent of the lobes. Very recently, lobes near the X-point have been experimentally observed in MAST [A. Kirk et al, PRL 108, 255003 (2012)]. We have used the DIII-D map [A. Punjabi, NF 49, 115020 (2009)] to calculate symplectic homoclinic tangles of the ideal separatrix of the DIII-D from the type I ELMs represented by the peeling-ballooning modes (m,n)=(30,10)+(40,10). The DIII-D map is symplectic, accurate, and is in natural canonical coordinates which are invertible to physical coordinates [A. Punjabi and H. Ali, POP 15, 122502 (2008)]. To our knowledge, we are the first to symplectically calculate these tangles in physical space. Homoclinic tangles of separatrix can cause radial displacement of mobile passing electrons and create sheared radial electric fields and currents, resulting in radial flows, drifts, differential spinning, and reduction in turbulence, and other effects. This work is supported by the grants DE-FG02-01ER54624 and DE-FG02-04ER54793.

Amyloid mediates the association of apolipoprotein E e4 allele to cognitive function in older people

PubMed Central

Bennett, D; Schneider, J; Wilson, R; Bienias, J; Berry-Kravis, E; Arnold, S

2005-01-01

Background: The neurobiological changes underlying the association of the apolipoprotein E (APOE) e4 allele with level of cognition are poorly understood. Objective: To test the hypothesis that amyloid load can account for (mediate) the association of the APOE e4 allele with level of cognition assessed proximate to death. Methods: There were 44 subjects with clinically diagnosed Alzheimer's disease and 50 without dementia, who had participated in the Religious Orders Study. They underwent determination of APOE allele status, had comprehensive cognitive testing in the last year of life, and brain autopsy at death. The percentage area of cortex occupied by amyloid beta and the density of tau positive neurofibrillary tangles were quantified from six brain regions and averaged to yield summary measures of amyloid load and neurofibrillary tangles. Multiple regression analyses were used to examine whether amyloid load could account for the effect of allele status on level of cognition, controlling for age, sex, and education. Results: Possession of at least one APOE e4 allele was associated with lower level of cognitive function proximate to death (p = 0.04). The effect of the e4 allele was reduced by nearly 60% and was no longer significant after controlling for the effect of amyloid load, whereas there was a robust inverse association between amyloid and cognition (p = 0.001). Because prior work had suggested that neurofibrillary tangles could account for the association of amyloid on cognition, we next examined whether amyloid could account for the effect of allele status on tangles. In a series of regression analyses, e4 was associated with density of tangles (p = 0.002), but the effect of the e4 allele was reduced by more than 50% and was no longer significant after controlling for the effect of amyloid load. Conclusion: These findings are consistent with a sequence of events whereby the e4 allele works through amyloid deposition and subsequent tangle formation to cause cognitive impairment. PMID:16107349

Talking about taste: using a discursive psychological approach to examine challenges to food evaluations.

PubMed

Wiggins, Sally

2004-08-01

This study is concerned with developing the interdisciplinary nature of food research, and with examining eating practices as they occur in everyday situations. The aim is to demonstrate how discursive approaches may contribute to eating research using a specific analytical example. A discursive psychological approach is used to examine mealtime conversations from 10 families with the analysis focusing on how food evaluations are challenged in interaction-for example, asking someone to justify what they think is 'wrong' with the food. Data are presented with 7 examples of the 30 challenges that were found within the data corpus. The analysis demonstrates how people may be held accountable for their expressed taste preferences when being challenged, and how this contributes to our understanding of eating as primarily an individual and embodied experience. It is argued that a specific and detailed analysis of eating interactions provides an alternative way of conceptualising food evaluations as discursive rather than mentalistic concepts. A discursive approach also opens up practical ways in which the social and familial aspects of eating may be examined as they occur as part of food practices.

Tangled Hierarchies: Teachers as Professionals and the Management of School. The Jossey-Bass Education Series.

ERIC Educational Resources Information Center

Shedd, Joseph B.; Bacharach, Samuel B.

Teachers need flexibility to adapt to the uncertain situations and unique needs they confront in their classrooms. Most efforts to reform public education address the needs of teachers at the expense of administration--and vice versa--reinforcing the tangled relationships and patterns of compromise and conflict they are meant to solve. This book…

Analysis of the effect of attachment point bias during large space debris removal using a tethered space tug

NASA Astrophysics Data System (ADS)

Chu, Zhongyi; Di, Jingnan; Cui, Jing

2017-10-01

Space debris occupies a valuable orbital resource and is an inevitable and urgent problem, especially for large space debris because of its high risk and the possible crippling effects of a collision. Space debris has attracted much attention in recent years. A tethered system used in an active debris removal scenario is a promising method to de-orbit large debris in a safe manner. In a tethered system, the flexibility of the tether used in debris removal can possibly induce tangling, which is dangerous and should be avoided. In particular, attachment point bias due to capture error can significantly affect the motion of debris relative to the tether and increase the tangling risk. Hence, in this paper, the effect of attachment point bias on the tethered system is studied based on a dynamic model established based on a Newtonian approach. Next, a safety metric of avoiding a tangle when a tether is tensioned with attachment point bias is designed to analyse the tangling risk of the tethered system. Finally, several numerical cases are established and simulated to validate the effects of attachment point bias on a space tethered system.

Habits and customs of crab catchers in southern Bahia, Brazil.

PubMed

Firmo, Angélica M S; Tognella, Mônica M P; Tenório, Gabrielle D; Barboza, Raynner R D; Alves, Rômulo R N

2017-08-23

Brazilian mangrove forests are widely distributed along the coast and exploited by groups of people with customs and habits as diverse as the biology of the mangrove ecosystems. This study identifies different methods of extracting crabs that inhabit the mangrove belts; some of these activities, such as catching individual crabs by hand, are aimed at maintaining natural stocks of this species in Mucuri (south Bahia), Brazil. In the studied community, illegal hunting activities that violate Brazilian legislation limiting the use of tangle-netting in mangrove ecosystem were observed. According to our observations, fishermen, to catch individual crabs, use the tangle-netting technique seeking to increase income and are from families that have no tradition of extraction. This analysis leads us to conclude that catchers from economically marginalised social groups enter mangroves for purposes of survival rather than for purposes of subsistence, because the catching by tangle-netting is a predatory technique. Tangle-netting  technique increase caught but also increases their mortality rate. We emphasise that traditional catching methods are unique to Brazil and that manual capturing of crab should be preserved through public policies aimed at maintaining the crab population.

Optical Coherence Tomography Angiography Reveals Mature, Tangled Vascular Networks in Eyes With Neovascular Age-Related Macular Degeneration Showing Resistance to Geographic Atrophy.

PubMed

Dansingani, Kunal K; Freund, K Bailey

2015-10-01

To demonstrate a vascular pattern seen on optical coherence tomography angiography (OCTA) that appears to correlate with reduced rates of geographic atrophy (GA) in eyes receiving long-term anti-vascular endothelial growth factor (VEGF) treatment for neovascular age-related macular degeneration (AMD). Non-consecutive, retrospective cohort study. Patients were included if they had received more than 50 anti-VEGF injections during a period of at least 4 years for neovascular AMD in at least one eye, with absence or minimal progression of GA. Clinical charts and imaging were reviewed retrospectively; study eyes underwent OCTA. Nine eyes of eight patients were included. Mean age was 82 years, and mean follow-up of study eyes 9.1 years; study eyes received a mean of 65.8 injections. OCTA revealed tangled networks of neovessels associated with type 1 lesions. With prolonged anti-VEGF treatment, GA appears to occur less commonly in eyes with type 1 neovascularization. OCTA shows mature tangled vessels with substantial flow within type 1 lesions. Mature, tangled networks may be associated with a decreased likelihood of developing GA despite the presence of choriocapillaris atrophy. Copyright 2015, SLACK Incorporated.

Homoclinic tangle of the ideal separatrix in the DIII-D tokamak from (30, 10) + (40, 10) perturbation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Punjabi, Alkesh

Trajectories of magnetic field lines are a 1½ degree of freedom Hamiltonian system. The perturbed separatrix in a divertor tokamak is radically different from the unperturbed one. This is because magnetic asymmetries cause the separatrix to form extremely complicated structures called homoclinic tangles. The shape of flux surfaces in the edge region of divertor tokamaks such as the DIII (J. L. Luxon and L. G. Davis, Fusion Technol. 8, 441 (1985)) is fundamentally different from near-circular. Recently, a new method is developed to calculate the homoclinic tangle and lobes of the separatrix of divertor tokamaks in physical space (A. Punjabimore » and A. Boozer, Phys. Lett. A 378, 2410 (2014)). This method is based on three elements: preservation of the two invariants—symplectic and topological neighborhood—and a new set of canonical coordinates called the natural canonical coordinates. The very complicated shape of edge surfaces can be represented very accurately and very realistically in these new coordinates (A. Punjabi and H. Ali, Phys. Plasmas 15, 122502 (2008); A. Punjabi, Nucl. Fusion 49, 115020 (2009)). A symplectic map in the new coordinates can advance the separatrix manifold forward and backward in time. Every time the two manifolds meet in a fixed poloidal plane, they intersect and form homoclinic tangle to preserve the two invariants. The new coordinates can be mapped to physical space and the dynamical evolution of the homoclinic tangle can be seen and pictured in physical space. Here, the new method is applied to the DIII-D tokamak to study the basic features of the homoclinic tangle of the unperturbed separatrix from two Fourier components, which represent the peeling-ballooning modes of equal amplitude and no radial dependence, and the results are analyzed. Homoclinic tangle has a very complicated structure and becomes extremely complicated for as the lines take more toroidal turns, especially near the X-point. Homoclinic tangle is the most complicated near the X-point and forms the largest lobes there. On average, the field lines cover a distance of about 9 m per turn. Poloidal rotation of the lines has large gradients in the poloidal direction. The average normal displacement of the lines on the separatrix varies from 5 mm to 7 cm. Average outward displacement of the lines is considerably larger than the inward displacement; however, on the average more lines are displaced inside than outside of the separatrix. The field line diffusion normal to the separatrix has extremely wide variation and very large poloidal gradients. Half of all the lines are lost in less than 6 turns. Complicated electric potentials will be required to maintain the neutrality of the plasma, and the E × B drifts from these fields can modify plasma confinement and influence the edge physics (A. Punjabi and A. Boozer, Phys. Lett. A 378, 2410 (2014))« less

Homoclinic tangle of the ideal separatrix in the DIII-D tokamak from (30, 10) + (40, 10) perturbation

NASA Astrophysics Data System (ADS)

Punjabi, Alkesh

2014-12-01

Trajectories of magnetic field lines are a 1½ degree of freedom Hamiltonian system. The perturbed separatrix in a divertor tokamak is radically different from the unperturbed one. This is because magnetic asymmetries cause the separatrix to form extremely complicated structures called homoclinic tangles. The shape of flux surfaces in the edge region of divertor tokamaks such as the DIII (J. L. Luxon and L. G. Davis, Fusion Technol. 8, 441 (1985)) is fundamentally different from near-circular. Recently, a new method is developed to calculate the homoclinic tangle and lobes of the separatrix of divertor tokamaks in physical space (A. Punjabi and A. Boozer, Phys. Lett. A 378, 2410 (2014)). This method is based on three elements: preservation of the two invariants—symplectic and topological neighborhood—and a new set of canonical coordinates called the natural canonical coordinates. The very complicated shape of edge surfaces can be represented very accurately and very realistically in these new coordinates (A. Punjabi and H. Ali, Phys. Plasmas 15, 122502 (2008); A. Punjabi, Nucl. Fusion 49, 115020 (2009)). A symplectic map in the new coordinates can advance the separatrix manifold forward and backward in time. Every time the two manifolds meet in a fixed poloidal plane, they intersect and form homoclinic tangle to preserve the two invariants. The new coordinates can be mapped to physical space and the dynamical evolution of the homoclinic tangle can be seen and pictured in physical space. Here, the new method is applied to the DIII-D tokamak to study the basic features of the homoclinic tangle of the unperturbed separatrix from two Fourier components, which represent the peeling-ballooning modes of equal amplitude and no radial dependence, and the results are analyzed. Homoclinic tangle has a very complicated structure and becomes extremely complicated for as the lines take more toroidal turns, especially near the X-point. Homoclinic tangle is the most complicated near the X-point and forms the largest lobes there. On average, the field lines cover a distance of about 9 m per turn. Poloidal rotation of the lines has large gradients in the poloidal direction. The average normal displacement of the lines on the separatrix varies from 5 mm to 7 cm. Average outward displacement of the lines is considerably larger than the inward displacement; however, on the average more lines are displaced inside than outside of the separatrix. The field line diffusion normal to the separatrix has extremely wide variation and very large poloidal gradients. Half of all the lines are lost in less than 6 turns. Complicated electric potentials will be required to maintain the neutrality of the plasma, and the E × B drifts from these fields can modify plasma confinement and influence the edge physics (A. Punjabi and A. Boozer, Phys. Lett. A 378, 2410 (2014)).

Constructions relatives et articulations discursives (Relative Constructions and Discursive Articulations)

ERIC Educational Resources Information Center

Henry, Paul

1975-01-01

Contrasts classical grammar, which concerned itself with the causal relationships of thought, universal order, and language, with modern linguistics, which tends to entirely absorb the matter of discourse. (Text is in French.) (Author/MSE)

"United We Stand": Framing Myalgic Encephalomyelitis in a Virtual Symbolic Community.

PubMed

Lian, Olaug S; Nettleton, Sarah

2015-10-01

In this article, we report on a study that seeks to explore how the contested chronic condition myalgic encephalomyelitis (ME), one of the current medical diagnoses for medically unexplained long-term exhaustion, is negotiated within the context of Norwegian internet sites. From an analysis of discussions on 14 internet forums sustained by and for people living with ME, we seek to understand how their online activity sustains a virtual symbolic community (VSC). After exploring the content on these sites, we identified four discursive domains, or fields of conversation, that are demarcated by a discursive frame, or norms, values, and goals that define and reinforce the boundaries of the community. Interpreting discursive domains and their discursive frame provides insight not only to the culture of the ME VSC but also to its role in an international social health movement, including its potential for becoming politically influential. © The Author(s) 2014.

The discursive production of classroom mathematics

NASA Astrophysics Data System (ADS)

Smith, Kim; Hodson, Elaine; Brown, Tony

2013-09-01

School mathematics is a function of its discursive environment where the language being used formats mathematical activity. The paper explores this theme through an extended example in which the conduct of mathematical teaching and learning is restricted by regulative educational policies. It considers how mathematics is discursively produced by student teachers within an employment-based model of teacher education in England where there is a low university input. It is argued that teacher reflections on mathematical learning and teaching within the course are patterned discursively in line with formal curriculum framings, assessment requirements and the local demands of their placement school. Both teachers and students are subject to regulative discourses that shape their actions and as a consequence this regulation influences the forms of mathematical activity that can take place. It is shown how university sessions can provide a limited critical platform from which to interrogate these restrictions and renegotiate them.

Rapid Neurofibrillary Tangle Formation after Localized Gene Transfer of Mutated Tau

PubMed Central

Klein, Ronald L.; Lin, Wen-Lang; Dickson, Dennis W.; Lewis, Jada; Hutton, Michael; Duff, Karen; Meyer, Edwin M.; King, Michael A.

2004-01-01

Neurofibrillary pathology was produced in the brains of adult rats after localized gene transfer of human tau carrying the P301L mutation, which is associated with frontotemporal dementia with parkinsonism. Within 1 month of in situ transfection of the basal forebrain region of normal rats, tau-immunoreactive and argyrophilic neuronal lesions formed. The fibrillar lesions had features of neurofibrillary tangles and tau immunoreactivity at light and electron microscopic levels. In addition to neurofibrillary tangles, other tau pathology, including pretangles and neuropil threads, was abundant and widespread. Tau gene transfer to the hippocampal region of amyloid-depositing transgenic mice produced pretangles and threads, as well as intensely tau-immunoreactive neurites in amyloid plaques. The ability to produce neurofibrillary pathology in adult rodents makes this a useful method to study tau-related neurodegeneration. PMID:14695347

Design, synthesis and biological evaluation of trimethine cyanine dyes as fluorescent probes for the detection of tau fibrils in Alzheimer's disease brain and olfactory epithelium.

PubMed

Gu, Jiamin; Anumala, Upendra Rao; Heyny-von Haußen, Roland; Hölzer, Jana; Goetschy-Meyer, Valérie; Mall, Gerhard; Hilger, Ingrid; Czech, Christian; Schmidt, Boris

2013-06-01

Shedding light on grey matter: Fluorescent trimethine cyanines were evaluated as imaging probes for neurofibrillary tangles in post-mortem brain sections of Alzheimer's disease patients. These probes bind to neurofibrillary tangles with high contrast and selectivity over amyloid β plaques. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Materials for Adaptive Structural Acoustic Control. Volume 1

DTIC Science & Technology

1993-04-06

FOLLOWING PAGE 14. SUBJECT TERMS 15. NUMBER OF PAGES 16. PRICE CODE 17. SECURITY CLASSIFICATION 18. SECURITY CLASSIFICATION 19. SECURITY CLASSIFICATION 20...375 Rubber is a highly nonlinear clastic medium. In the unstressed compliant state, the molecules ate coiled and tangled . but under stress the molecules...one-dimensional system, \\\\here tangle (solid dots) and the oblique (open circle) states are the shaded area represents the level of thermal energy

Chapter Four: Discursive Resources

ERIC Educational Resources Information Center

Young, Richard F.

2008-01-01

In this chapter, the focus of attention moves from the contexts described in chapter 3 to the verbal, nonverbal, and interactional resources that participants employ in discursive practices. These resources are discussed within the frame of participation status and participation framework proposed by Goffman. Verbal resources employed by…

Employing Discourse: Universities and Graduate "Employability"

ERIC Educational Resources Information Center

Boden, Rebecca; Nedeva, Maria

2010-01-01

What constitutes graduate employability is discursively framed. In this paper we argue that whilst universities in the UK have long had an involvement in producing useful and productive citizens, the ongoing neoliberalisation of higher education has engendered a discursive shift in definitions of employability. Traditionally, universities regarded…

Neuropathological Alterations in Alzheimer Disease

PubMed Central

Serrano-Pozo, Alberto; Frosch, Matthew P.; Masliah, Eliezer; Hyman, Bradley T.

2011-01-01

The neuropathological hallmarks of Alzheimer disease (AD) include “positive” lesions such as amyloid plaques and cerebral amyloid angiopathy, neurofibrillary tangles, and glial responses, and “negative” lesions such as neuronal and synaptic loss. Despite their inherently cross-sectional nature, postmortem studies have enabled the staging of the progression of both amyloid and tangle pathologies, and, consequently, the development of diagnostic criteria that are now used worldwide. In addition, clinicopathological correlation studies have been crucial to generate hypotheses about the pathophysiology of the disease, by establishing that there is a continuum between “normal” aging and AD dementia, and that the amyloid plaque build-up occurs primarily before the onset of cognitive deficits, while neurofibrillary tangles, neuron loss, and particularly synaptic loss, parallel the progression of cognitive decline. Importantly, these cross-sectional neuropathological data have been largely validated by longitudinal in vivo studies using modern imaging biomarkers such as amyloid PET and volumetric MRI. PMID:22229116

Ultrastructural localization of acetylcholinesterase in neurofibrillary tangles, neuropil threads and senile plaques in aged and Alzheimer's brain.

PubMed

Gomez-Ramos, P; Mufson, E J; Moran, M A

1992-01-13

Acetylcholinesterase (AChE) histochemistry was used to evaluate the accumulation of this enzyme in senile plaques, neurofibrillary tangles and neuropil threads using light and electron microscopy in Alzheimer's disease as well as non-demented aged brains. Under the electron microscope, a crystalline-like AChE precipitate was localized over paired helical filaments and straight filaments in both neurofibrillary tangles and neuropil threads. AChE reaction product also decorated the amyloid fibrils in diffuse plaques as well as the halo and the heavy accumulation of amyloid which forms the core of classical plaques. In both diffuse plaques and the halo of classical plaques, we found AChE-positive structures resembling cell processes, which in some cases appeared to contain amyloid fibrils. The possible origin and significance of AChE localized over paired helical filaments, straight filaments and amyloid is discussed.

Ising Model on Tangled Chain, Some Thermodynamic Properties

NASA Astrophysics Data System (ADS)

Mejdani, R.

1996-09-01

In this paper we consider an Ising model on tangled chain, where some additional bonds compared to a pure Ising chain are presented. To understand the behavior of this system and the competition between ferromagnetic bonds J along the chain and antiferromagnetic bonds J' across the chain, we have studied in detail analytically and iteratively some of the thermodynamic quantities. Particularly interesting is, in the zero-field and zero-temperature limit, the behavior of the magnetization and the susceptibility closely related to the ground-state configurations and their degeneracies. This degeneracy, presented at the condition J' ≤ -J between J and J', explains, also, the existence of nonzero entropy at zero temperature. This model applied as a lattice gas model defined on a tangled chain could be also useful for the experimental investigations in studying the saturation curves for the enzyme kinetics or the melting curves for DNA-denaturation.

Vortex knots in tangled quantum eigenfunctions

PubMed Central

Taylor, Alexander J.; Dennis, Mark R.

2016-01-01

Tangles of string typically become knotted, from macroscopic twine down to long-chain macromolecules such as DNA. Here, we demonstrate that knotting also occurs in quantum wavefunctions, where the tangled filaments are vortices (nodal lines/phase singularities). The probability that a vortex loop is knotted is found to increase with its length, and a wide gamut of knots from standard tabulations occur. The results follow from computer simulations of random superpositions of degenerate eigenstates of three simple quantum systems: a cube with periodic boundaries, the isotropic three-dimensional harmonic oscillator and the 3-sphere. In the latter two cases, vortex knots occur frequently, even in random eigenfunctions at relatively low energy, and are constrained by the spatial symmetries of the modes. The results suggest that knotted vortex structures are generic in complex three-dimensional wave systems, establishing a topological commonality between wave chaos, polymers and turbulent Bose–Einstein condensates. PMID:27468801

Clinicopathologic and 11C-Pittsburgh compound B implications of Thal amyloid phase across the Alzheimer’s disease spectrum

PubMed Central

Lowe, Val J.; Graff-Radford, Neill R.; Liesinger, Amanda M.; Cannon, Ashley; Przybelski, Scott A.; Rawal, Bhupendra; Parisi, Joseph E.; Petersen, Ronald C.; Kantarci, Kejal; Ross, Owen A.; Duara, Ranjan; Knopman, David S.; Jack, Clifford R.; Dickson, Dennis W.

2015-01-01

Thal amyloid phase, which describes the pattern of progressive amyloid-β plaque deposition in Alzheimer’s disease, was incorporated into the latest National Institute of Ageing – Alzheimer’s Association neuropathologic assessment guidelines. Amyloid biomarkers (positron emission tomography and cerebrospinal fluid) were included in clinical diagnostic guidelines for Alzheimer’s disease dementia published by the National Institute of Ageing – Alzheimer’s Association and the International Work group. Our first goal was to evaluate the correspondence of Thal amyloid phase to Braak tangle stage and ante-mortem clinical characteristics in a large autopsy cohort. Second, we examined the relevance of Thal amyloid phase in a prospectively-followed autopsied cohort who underwent ante-mortem 11C-Pittsburgh compound B imaging; using the large autopsy cohort to broaden our perspective of 11C-Pittsburgh compound B results. The Mayo Clinic Jacksonville Brain Bank case series (n = 3618) was selected regardless of ante-mortem clinical diagnosis and neuropathologic co-morbidities, and all assigned Thal amyloid phase and Braak tangle stage using thioflavin-S fluorescent microscopy. 11C-Pittsburgh compound B studies from Mayo Clinic Rochester were available for 35 participants scanned within 2 years of death. Cortical 11C-Pittsburgh compound B values were calculated as a standard uptake value ratio normalized to cerebellum grey/white matter. In the high likelihood Alzheimer’s disease brain bank cohort (n = 1375), cases with lower Thal amyloid phases were older at death, had a lower Braak tangle stage, and were less frequently APOE-ε4 positive. Regression modelling in these Alzheimer’s disease cases, showed that Braak tangle stage, but not Thal amyloid phase predicted age at onset, disease duration, and final Mini-Mental State Examination score. In contrast, Thal amyloid phase, but not Braak tangle stage or cerebral amyloid angiopathy predicted 11C-Pittsburgh compound B standard uptake value ratio. In the 35 cases with ante-mortem amyloid imaging, a transition between Thal amyloid phases 1 to 2 seemed to correspond to 11C-Pittsburgh compound B standard uptake value ratio of 1.4, which when using our pipeline is the cut-off point for detection of clear amyloid-positivity regardless of clinical diagnosis. Alzheimer’s disease cases who were older and were APOE-ε4 negative tended to have lower amyloid phases. Although Thal amyloid phase predicted clinical characteristics of Alzheimer’s disease patients, the pre-mortem clinical status was driven by Braak tangle stage. Thal amyloid phase correlated best with 11C-Pittsburgh compound B values, but not Braak tangle stage or cerebral amyloid angiopathy. The 11C-Pittsburgh compound B cut-off point value of 1.4 was approximately equivalent to a Thal amyloid phase of 1–2. PMID:25805643

Discursive Tactical Negotiations within and across Literacy Coaching Interactions

ERIC Educational Resources Information Center

Hunt, Carolyn S.

2013-01-01

In this dissertation, the researcher employed de Certeau's theoretical insights into cultural production in everyday life to examine how literacy coaches and teachers discursively negotiated issues of identity, power, and positioning during coaching interactions. The study also explored how literacy coaches and teachers enacted emotions within…

College English Learners' Discursive Motivation Construction in China

ERIC Educational Resources Information Center

Gu, Mingyue

2009-01-01

There are abundant studies of second/foreign language learning motivation. However, there appears to be insufficient research into how language learners' discourses mediate the construction of their learning/motivation. This paper investigated the discursive construction of two English language learners' motivation in a comprehensive university in…

Michel Foucault's Theory of Rhetoric as Epistemic.

ERIC Educational Resources Information Center

Foss, Sandra K.; Gill, Ann

1987-01-01

Formulates a middle-level theory that explains the process by which rhetroic is epistemic, using Foucault's notion of the discursive formation as a starting point. Discusses five theoretical units derived from Foucault--discursive practices, rules, roles, power, and knowledge--and relationships among them. Analyzes Disneyland, using Foucault's…

Literacy at Calhoun Colored School, 1892-1945.

ERIC Educational Resources Information Center

Willis, Arlette Ingram

2002-01-01

Examines the historical experiences and struggles of African Americans seeking literacy access during the post Reconstruction Era. Reveals interconnections of power/knowledge relations and discursive practices of the Hampton-Tuskegee model of education that shaped literacy access and opportunity; and these discursive practices framed the school's…

The Discursive Enactment of Hegemony: Sexual Harassment and Academic Organizing.

ERIC Educational Resources Information Center

Townsley, Nikki C.; Geist, Patricia

2000-01-01

Contributes to scholarship advancing the understanding of human communication, illustrating the discursive enactment of hegemony through organizational responses to sexual harassment. Analyzes stories from both victims of sexual harassment and administrators who manage sexual harassment complaints at a major United States university. Argues that…

Ion Viscosity Mediated by Tangled Magnetic Fields: An Application to Black Hole Accretion Disks

NASA Technical Reports Server (NTRS)

Subramanian, Prasad; Becker, Peter A.; Kafatos, Menas

1996-01-01

We examine the viscosity associated with the shear stress exerted by ions in the presence of a tangled magnetic field. As an application, we consider the effect of this mechanism on the structure of black hole accretion disks. We do not attempt to include a self-consistent description of the magnetic field. Instead, we assume the existence of a tangled field with coherence length lambda(sub coh), which is the average distance between the magnetic 'kinks' that scatter the particles. For simplicity, we assume that the field is self-similar, and take lambda(sub coh) to be a fixed fraction zeta of the local disk height H. Ion viscosity in the presence of magnetic fields is generally taken to be the cross-field viscosity, wherein the effective mean free path is the ion Larmor radius lambda(sub L), which is much less than the ion-ion Coulomb mean free path A(sub ii) in hot accretion disks. However, we arrive at a formulation for a 'hybrid' viscosity in which the tangled magnetic field acts as an intermediary in the transfer of momentum between different layers in the shear flow. The hybrid viscosity greatly exceeds the standard cross-field viscosity when (lambda/lambda(sub L)) much greater than (lambda(sub L)/lambda(sub ii)), where lambda = ((lambda(sub ii)(sup -1) + lambda(sub (coh)(sup -1))(sup -1) is the effective mean free path for the ions. This inequality is well satisfied in hot accretion disks, which suggests that the ions may play a much larger role in the momentum transfer process in the presence of magnetic fields than was previously thought. The effect of the hybrid viscosity on the structure of a steady-state, two-temperature, quasi-Keplerian accretion disk is analyzed. The hybrid viscosity is influenced by the degree to which the magnetic field is tangled (represented by zeta = lambda(sub coh)), and also by the relative accretion rate M/M(sub E), where M(sub E) = L(sub E)/c(sup 2) and L(sub E) is the Eddington luminosity. We find that ion viscosity in the presence of magnetic fields (hybrid viscosity) can dominate over conventional magnetic viscosity for fields that are tangled on sufficiently small scales.

Co-Authoring Gender-Queer Youth Identities: Discursive "Tellings" and "Retellings"

ERIC Educational Resources Information Center

Saltzburg, Susan; Davis, Tamara S.

2010-01-01

For youth who challenge the culturally fixed gender dichotomy through nonconventional gender expression, societal reaction can be harsh. Uncovering these youth voices as they pioneer new gender frontiers through pathways of language and social dialogue provides the focus for this manuscript. Drawing from discursive, narrative practices, we sat in…

Curious Hybrids: Creating "Not-Quite" Beings to Explore Possible Childhoods

ERIC Educational Resources Information Center

Knight, Linda

2016-01-01

Communications between adults and young children can expose different ideas and opinions. Adults and children have different capacities to speak, these discursive spaces can become filled with assumptions, stereotyping and conventional thinking about power and agency. If communication shifts away from the purely discursive, what might be exposed…

Stratification of Environmental Education and Education for Sustainable Development in Australia: An Analysis of Positions Vacant Advertisements

ERIC Educational Resources Information Center

Hardy, Joy

2008-01-01

Positions vacant advertisements discursively construct employment sectors, employers and employees. This paper uses content analysis, systemic functional linguistics and critical discourse analysis to investigate the discursive construction of environmental education and education for sustainable development through positions vacant advertisements…

Humanism and Autonomy in the Neoliberal Reform of Teacher Training

ERIC Educational Resources Information Center

Kascak, Ondrej; Pupala, Branislav; Petrova, Zuzana

2011-01-01

This article analyses the discursive unities which make possible the current transformation of teacher training and our understanding of teaching as a profession, while focusing particularly on European educational policy and the situation in Slovakia. Using Foucault's archaeological method, we reconstruct the discursive link points between the…

Discursive Constructions of Literacies: Shifting Sands in Aotearoa New Zealand

ERIC Educational Resources Information Center

Sandretto, Susan; Tilson, Jane

2017-01-01

Literacy policy and pedagogy in Aotearoa New Zealand have a strong discursive heritage of traditional literacies, which emphasise code breaking and meaning making with linguistic codes and conventions over other possible modes of communication. In a rapidly evolving landscape where changes in communication technologies give birth to new literacies…

Positioning Personal Discourse Professionally.

ERIC Educational Resources Information Center

McGann, Patrick

Although a Ph.D. candidate feels pressured to take sides in the discursive war in academe between social-epistemics and expressionists, he finds it difficult to do so. W. Ross Winterowd, a "spokesperson" for social-epistemic rhetoric, makes distinctions between the two camps, maintaining a discursive dichotomy between what he calls the…

A Discursive Construction of Homosexual Males in a Muslim-Dominant Community

ERIC Educational Resources Information Center

Shamsudin, Zainon; Ghazali, Kamila

2011-01-01

This paper addresses the issue of identity construction of four young Malay homosexual men in Malaysia. Through narrative discourse of their lifeworlds (Habermas, Theory of communicative action, Polity Press, 1987), this study explores the participants' linguistic repertoire and discursive strategies in the formation, negotiation and establishment…

The Discursive Practice of Participation in an Elementary Classroom Community

ERIC Educational Resources Information Center

Kovalainen, Minna; Kumpulainen, Kristiina

2005-01-01

This study examines the discursive practice of participation in an elementary classroom community aiming towards collective meaning-making and joint creation of knowledge. The theoretical and methodological basis of the study is shaped by the sociocultural and socio-linguistic approaches. Through examining the communicative practices and…

Discursive Essentializing in a Woman-Owned Business: Gendered Stereotypes and Strategic Subordination.

ERIC Educational Resources Information Center

Edley, Paige P.

2000-01-01

Illustrates how the cultural practice of discursive essentializing in a woman-owned and operated business accomplished simultaneous agendas of power and resistance. Shows how the performance of gendered stereotypes, rather than having expected negative consequences, allowed organizational members to suppress conflict and to reproduce the owners'…

The Helms-Burton Act: A Strategic Critique.

DTIC Science & Technology

1998-03-31

Sänger, "U.S.- Canadian Split on Cuba Tangles Wal-Mart’s Pajamas ," The New York Times, 6 March 1997, Sec. A, pi. An unintended consequence of the...organizational framework; without strategy, tactics, or historical perspective; without a language, library, data bank , complete intelligence...Sänger, David E. "U.S.-Canadian Split on Cuba Tangles Wal-Mart’s Pajamas ." The New York Times, Sec. A, pi. "Saying Boo to Helms-Burton." The

The influence of phospho-τ on dendritic spines of cortical pyramidal neurons in patients with Alzheimer's disease.

PubMed

Merino-Serrais, Paula; Benavides-Piccione, Ruth; Blazquez-Llorca, Lidia; Kastanauskaite, Asta; Rábano, Alberto; Avila, Jesús; DeFelipe, Javier

2013-06-01

The dendritic spines on pyramidal cells represent the main postsynaptic elements of cortical excitatory synapses and they are fundamental structures in memory, learning and cognition. In the present study, we used intracellular injections of Lucifer yellow in fixed tissue to analyse over 19 500 dendritic spines that were completely reconstructed in three dimensions along the length of the basal dendrites of pyramidal neurons in the parahippocampal cortex and CA1 of patients with Alzheimer's disease. Following intracellular injection, sections were immunostained for anti-Lucifer yellow and with tau monoclonal antibodies AT8 and PHF-1, which recognize tau phosphorylated at Ser202/Thr205 and at Ser396/404, respectively. We observed that the diffuse accumulation of phospho-tau in a putative pre-tangle state did not induce changes in the dendrites of pyramidal neurons, whereas the presence of tau aggregates forming intraneuronal neurofibrillary tangles was associated with progressive alteration of dendritic spines (loss of dendritic spines and changes in their morphology) and dendrite atrophy, depending on the degree of tangle development. Thus, the presence of phospho-tau in neurons does not necessarily mean that they suffer severe and irreversible effects as thought previously but rather, the characteristic cognitive impairment in Alzheimer's disease is likely to depend on the relative number of neurons that have well developed tangles.

Dynamics of the density of quantized vortex lines in counterflow turbulence: Experimental investigation

NASA Astrophysics Data System (ADS)

Varga, E.; Skrbek, L.

2018-02-01

Recently the interest in thermal counterflow of superfluid 4He, the most extensively studied form of quantum turbulence, has been renewed. Particularly, an intense theoretical debate has arisen about what form, if any, of the so-called Vinen equation accurately captures the dynamics of vortex line density, L . We address this problem experimentally, in a 21 cm long channel of square 7 ×7 mm2 cross section. Based on large statistics of second-sound data measured in nonequilibrium square-wave modulated thermally induced counterflow we investigate the phase portrait of the general form of the governing dynamical equation and conclude that for sparse tangles (L ≲105cm-2) all proposed forms of this equation based on the concept of a homogeneous random tangle of quantized vortices provide equally adequate descriptions of the growth of L , while for dense tangles (L >105cm-2) none of them is satisfactory or able to account for the significant slow-down in tangle growth rate as the steady state is approached. We claim, however, that agreement with theory is recovered if the geometrical parameter c2 introduced in numerical studies by K. W. Schwarz [Phys. Rev. B 38, 2398 (1988), 10.1103/PhysRevB.38.2398] is allowed to vary with vortex line density which also greatly improves the prediction of the observed early decay rate.

Review: Tau in biofluids - relation to pathology, imaging and clinical features.

PubMed

Zetterberg, H

2017-04-01

Tau is a microtubule-binding protein that is important for the stability of neuronal axons. It is normally expressed within neurons and is also secreted into the brain interstitial fluid that communicates freely with cerebrospinal fluid (CSF) and, in a more restricted manner, blood via the glymphatic clearance system of the brain. In Alzheimer's disease (AD), neuroaxonal degeneration results in increased release of tau from neurons. Furthermore, tau is truncated and phosphorylated, which leads to aggregation of tau in neurofibrillary tangles of the proximal axoplasm. Neuroaxonal degeneration and tangle formation are reflected by increased concentrations of total tau (T-tau, measured using assays that detect most forms of tau) and phospho-tau (P-tau, measured using assays with antibodies specific to phosphorylated forms of tau). In AD CSF, both T-tau and P-tau concentrations are increased. In stroke and other CNS disorders with neuroaxonal injury but without tangles, T-tau is selectively increased, whereas P-tau concentration often stays normal. In tauopathies (diseases with both neurodegeneration and neurofibrillary tangles) other than AD, CSF T-tau and P-tau concentrations are typically unaltered, which is a puzzling result that warrants further investigation. In the current review, I discuss the association of T-tau and P-tau concentrations in body fluids with neuropathological changes, imaging findings and clinical features in AD and other CNS diseases. © 2017 British Neuropathological Society.

Tau proteins in the cerebrospinal fluid of patients with subacute sclerosing panencephalitis.

PubMed

Yuksel, Deniz; Yilmaz, Deniz; Uyar, Neval Y; Senbil, Nesrin; Gurer, Yavuz; Anlar, Banu

2010-06-01

Neurodegenerative diseases characterized by cytoskeletal deformation and neurofibrillary tangles are associated with altered levels of tau and related proteins in cerebrospinal fluid (CSF). Neuronal or glial fibrillary tangles have been shown in 20% of subacute sclerosing panencephalitis (SSPE) patients. We therefore investigated CSF samples from 60 newly diagnosed SSPE and 31 neurological control patients for total tau (t-tau), phosphorylated tau (p-tau), and S100-B levels by ELISA. There was no difference between patient and control groups in t-tau and S100-B levels. p-Tau was lower in the SSPE group (p=0.009). Past history of measles infection, measles immunization status, latent period between measles and onset of SSPE, duration of symptoms, frequency of myoclonia, neurological deficit index, stage and progression rate of the disease, CSF glucose levels and cell counts, CSF and serum measles IgG titer, distribution of lesions on brain magnetic resonance imaging were not related to t-tau, p-tau and S100-B levels. Mental status and age were negatively correlated with t-tau, and male gender and EEG abnormalities were associated with higher t-tau levels. The levels of tau proteins in our patients suggest there is no, or only scarce and immature, neurofibrillary tangle formation in SSPE. Autopsy studies showing neurofibrillary tangles might have examined older patients with longer disease and more parenchymal involvement. Copyright (c) 2009 Elsevier B.V. All rights reserved.

Preservice Teacher Agency Concerning Education for Sustainability (EfS): A Discursive Psychological Approach

ERIC Educational Resources Information Center

Martin, Jenny; Carter, Lyn

2015-01-01

In this paper, we utilize a discursive psychological approach to further explore agency and structure in science education research. The aim of our research is to understand how we can provide opportunities for marginalized students in preservice elementary teacher education in an Australian university to become agentic concerning environmental…

The "Ofcourseness" of Functional Literacy: Ideologies in Adult Literacy

ERIC Educational Resources Information Center

Perry, Kristen H.; Shaw, Donita M.; Ivanyuk, Lyudmyla; Tham, Yuen San Sarah

2018-01-01

We used metastudy and metasynthesis techniques to conduct a discursive review of 101 recent publications on the topic of adult functional literacy (FL). Our purpose was to understand the ideologies shaping current definitions and conceptualizations of FL, as well as how and why FL is researched and assessed as it is. Using discursive review…

A Review of Modeling Pedagogies: Pedagogical Functions, Discursive Acts, and Technology in Modeling Instruction

ERIC Educational Resources Information Center

Campbell, Todd; Oh, Phil Seok; Maughn, Milo; Kiriazis, Nick; Zuwallack, Rebecca

2015-01-01

The current review examined modeling literature in top science education journals to better understand the pedagogical functions of modeling instruction reported over the last decade. Additionally, the review sought to understand the extent to which different modeling pedagogies were employed, the discursive acts that were identified as important,…

The Literacies of Things: Reconfiguring the Material-Discursive Production of Race and Class in an Informal Learning Centre

ERIC Educational Resources Information Center

Thiel, Jaye Johnson; Jones, Stephanie

2017-01-01

Drawing on our documentation of transforming an informal learning centre (the Playhouse) in a multilingual, working-class neighbourhood, this paper presents significant and deliberate material-discursive changes at the Playhouse that produced unpredictable shifts in belongings among young children. More specifically, this paper entwines our…

Whose Literacy? Discursive Constructions of Life and Objectivity

ERIC Educational Resources Information Center

Fendler, Lynn; Tuckey, Steven F.

2006-01-01

Drawing from literature in the social studies of science, this paper historicizes two pivotal concepts in science literacy: the definition of life and the assumption of objectivity. In this paper we suggest that an understanding of the historical, discursive production of scientific knowledge affects the meaning of scientific literacy in at least…

Writer Identity Construction in Mexican Students of Applied Linguistics

ERIC Educational Resources Information Center

Mora, Alberto

2017-01-01

The paper examines the connection between discursive and non-discursive features and the construction of writer identity. In particular, the paper compares and contrasts the writer identity development of two groups of undergraduate students of applied linguistics in the Mexican context, one made up of locally educated ones and the other composed…

Process and Post-Process: A Discursive History.

ERIC Educational Resources Information Center

Matsuda, Paul Kei

2003-01-01

Examines the history of process and post-process in composition studies, focusing on ways in which terms, such as "current-traditional rhetoric,""process," and "post-process" have contributed to the discursive construction of reality. Argues that use of the term post-process in the context of second language writing needs to be guided by a…

Discursive Battles about the Meaning of University: The Case of Danish University Reform and Its Academics

ERIC Educational Resources Information Center

Krejsler, John

2006-01-01

The meaning of university and, subsequently, academics' working conditions are rapidly changing as knowledge economy and globalisation discourses continue to deepen across the Western world. Higher education and research agendas are increasingly staged in the discursive universe of knowledge economy language: common strategies and harmonisation…

Ethnicity and Education in China and Vietnam: Discursive Formations of Inequality

ERIC Educational Resources Information Center

DeJaeghere, Joan; Wu, Xinyi; Vu, Lisa

2015-01-01

This article aims to understand how ethnicity is discursively framed in national policies in China and Vietnam and argues that policy discourses affect how the "problem" of ethnicity and educational inequalities is framed and how these inequalities can be addressed. The analysis shows how both Marxist and market-economy governing…

Discursive "Policy Logics" of Mergers in US Higher Education: Strategy or Tragedy?

ERIC Educational Resources Information Center

Stephenson, Sandria S.

2011-01-01

Mergers are part of the historical fabric of US higher education. However, the current economic recession and other policy issues have experts and academicians predicting an increase in higher education mergers in the USA. Consequently, this study analysed the discursive "policy logics" surrounding merger negotiations in US higher…

Linguistic Legitimation of Political Events in Newspaper Discourse

ERIC Educational Resources Information Center

Ali, Marwah Kareem; Christopher, Anne A.; Nordin, Munif Zarirruddin Fikri B.

2016-01-01

This paper examines the discursive structures employed in legitimizing the event of U.S. forces withdrawal from Iraq and identifies them in relation to linguistic features. It attempts to describe the relation between language use and legitimation discursive structures in depicting political events. The paper focuses on the political event of U.S.…

Discursive Institutionalism: Towards a Framework for Analysing the Relation between Policy and Curriculum

ERIC Educational Resources Information Center

Wahlström, Ninni; Sundberg, Daniel

2018-01-01

Discourse approaches in education policy analysis have gained prominence in the last decade. However, though the literature on policy discourses is growing, different conceptions of the "discursive" dimension and its potential for empirical analysis related to the field of curriculum policy have not yet been fully researched. To address…

Ethnic Minority Students from South Asia in Hong Kong: Language Ideologies and Discursive Identity Construction

ERIC Educational Resources Information Center

Gu, Mingyue Michelle; Mak, Barley; Qu, Xiaoyuan

2017-01-01

This article explores how ethnic minority students in Hong Kong secondary schools discursively construct their identities in relation to culture, heritage, and social discourse. It finds that the ethnic minority students negotiate their identities within multiple positioning from parents, school, and the broader social discourse on minority…

The "Illusion of Life" Rhetorical Perspective: An Integrated Approach to the Study of Music as Communication.

ERIC Educational Resources Information Center

Sellnow, Deanna; Sellnow, Timothy

2001-01-01

Suggests the "illusion of life" rhetorical perspective increases understanding about how discursive linguistic symbols and non-discursive aesthetic symbols function together to communicate and persuade in didactic music. Argues that lyrics and music work together to offer messages comprised of both conceptual and emotional content…

Disruptive Events: Elite Education and the Discursive Production of Violence

ERIC Educational Resources Information Center

Saltmarsh, Sue

2008-01-01

This paper considers the discursive production of violence in the context of educational markets. Drawing on a larger study of sexually violent incidents that occurred in an elite private boys' school in Sydney, Australia, in 2000, the paper examines disciplinary traditions and communicative practices surrounding these events. Insights from Michel…

Humor-ing the Local: Multivocal Performance in Stand-Up Comedy in Hawai'i

ERIC Educational Resources Information Center

Furukawa, Toshiaki

2011-01-01

This dissertation takes a discursive approach to Hawai'i stand-up comedy, which is a highly dramaturgical genre, and it examines the cultural specificity of Hawaii comedy in an explicitly interactional context. This culturally-specific performative genre is a discursive site where comedians and their audiences jointly construct multivocal humor…

Discursive Shadowing in Linguistic Ethnography. Situated Practices and Circulating Discourses in Multilingual Schools

ERIC Educational Resources Information Center

Dewilde, Joke; Creese, Angela

2016-01-01

We consider discursive shadowing as methodology in linguistic ethnography and how it refines our analyses of participants' situated practices. In addition to the constant and extended company the researcher and key participant keep with one another in the field, shadowing in a linguistic ethnographic approach includes the ubiquitous…

Discursive Strategies in Corporate Image Building of Monsanto

ERIC Educational Resources Information Center

Koca-Helvaci, Zeynep Cihan

2017-01-01

Since the public's awareness and interest in the usage of biotechnology in agriculture has increased drastically, this study seeks to discover the macro and micro discursive strategies in corporate image building by Monsanto, which is not only the leader but also happens to be the most criticized company of the agribusiness market (Mitchell,…

Discursive Power and Creativity in Inter-Professional Work

ERIC Educational Resources Information Center

Paloniemi, Susanna; Collin, Kaija

2012-01-01

This paper discusses how discursive power and creativity are found to be inter-related in a context not traditionally associated with creative work; the operating theatre of a hospital. Here, it is proposed that creativity relies on socio-cultural factors emphasizing the practical nature of creativity, and highlighting the fact that a large part…

Language Policy, In-Migration and Discursive Debates in Wales

ERIC Educational Resources Information Center

Edwards, Catrin Wyn

2017-01-01

Drawing on theory from critical language policy literature, this article explores the impact of discourses on in-migration on Welsh language policy. By focussing on discursive debates surrounding the subject of in-migration, the article analyses how a range of actors produce and reproduce discourses on in-migration in Wales and how these…

The Discursive Framing of International Education Programs in British Columbia

ERIC Educational Resources Information Center

Cover, Dwayne

2016-01-01

This study examines how international education programs in British Columbia have been discursively framed by government and media sources. Over the past two decades, international education programs have expanded in number and scale in the province, a phenomenon that has been interpreted by some education researchers and media sources as…

Deliberative Teacher Education beyond Boundaries: Discursive Practices for Eliciting Gender Awareness

ERIC Educational Resources Information Center

Mooney Simmie, Geraldine; Lang, Manfred

2018-01-01

This study uses boundary crossing in activity theory as one normative framework for opening a deliberative inquiry in new discursive spaces to elicit "gender awareness" in teachers' practices. We illustrate this framework by drawing from data in one European teacher education project. Seven case studies were conducted and data were…

Discursive Obstruction and Elite Opposition to Environmental Activism in the Czech Republic

ERIC Educational Resources Information Center

Shriver, Thomas E.; Adams, Alison E.; Cable, Sherry

2013-01-01

Extant research on social movements has highlighted activists' discursive tactics to challenge the state, yet little analytical attention focuses on elite efforts to dominate the discourse arena through the deployment of oppositional frames. This paper analyzes elite oppositional framing surrounding the placement of a highway bypass in the Czech…

Discursive Construction of Social Presence and Identity Positions in an International Bilingual Collaboration

ERIC Educational Resources Information Center

Walker, Ute

2017-01-01

This article examines the discursive construction of social presence and identity in a bilingual collaboration between tertiary distance learners of German in New Zealand and Academic English students in Germany. Drawing on positioning theory, this small-scale study investigated the collaborative practices of a group of students, whose synchronous…

Normative Beliefs, Discursive Claims, and Implementation of Reform-Based Science Standards

ERIC Educational Resources Information Center

Veal, William R.; Riley Lloyd, Mary E.; Howell, Malia R.; Peters, John

2016-01-01

Reform-based science instruction is guided by teachers' normative beliefs. Discursive claims are how teachers say they teach science. Previous research has studied the change in teachers' beliefs and how beliefs influence intended practice and action in the classroom. Few studies have connected what teachers believe, how they say they teach, and…

Education, Justice, and Discursive Agency: Toward an Educationally Responsive Discourse Ethics

ERIC Educational Resources Information Center

Martin, Christopher

2016-01-01

Jürgen Habermas argues that principles of justice should be decided through rational agreement as opposed to force or coercion. Christopher Martin argues in this essay that the success of such a project presupposes sufficiently developed capacities for discursive agency equally distributed within a diverse public sphere. This epistemic…

On Making the I Universal: From Langer to Britton to Kinneavy.

ERIC Educational Resources Information Center

Golson, Emily Becker; Kirscht, Judith

According to S. K. Langer, people create meaning through presentational and discursive symbolism. Presentational symbolism, Langer suggests, is an abstracted sense of experienced life, while discursive symbolism is a series of subordinating or coordinating positions that set in motion the relation of ideas and permits the discussion of causation.…

The discursive self-construction of suicidal help seekers in computer-mediated discourse.

PubMed

Kupferberg, Irit; Gilat, Izhak

2012-01-01

The study focuses on the discursive self-construction of suicidal help seekers in an open computer-mediated forum for mental help. Our theoretical framework is inspired by a functionalist approach to discourse, which emphasizes that language resources are self-displaying. It also espouses discursive psychology, which prioritizes the study of psychological and social phenomena in discursive processes. In addition, we adopt the Four World Approach to the analysis of positioning. Qualitative and quantitative analyses show that the density of 'irrealis' (i.e. negation, future and wishes) units and figurative forms was significantly higher in the suicidal messages compared with the messages of other troubled selves, who produced more 'realis' units (i.e. specific and generic stories) and information questions. We interpret these findings as showing that in their attempt to conceptualize conflict and pain, suicidal help-seekers shied away from the narration of past experience and focused instead on the construction of death. The other troubled help seekers used realis units and questions in order to describe their experience to guarantee that help would be provided.

Non-Back-Drivable, Freewheeling Coupling

NASA Technical Reports Server (NTRS)

Llewellin, W.

1986-01-01

Cables reeled in and out with less risk of tangling. Opposing teeth engage with clockwise rotation and disengage with clockwise rotation of crank. Driving plate moves axially with respect to driven plate on ball points to engage and disengage. Clutch developed for reeling and unreeling tether line used to link astronaut to space vehicle. Allows line pulled out freely and helps to prevent line from tangling in reel housing when crank is turned backward. New clutch concept also applicable to fishing reels, toys, and safety-line mechanisms.

Decision making on fitness landscapes

NASA Astrophysics Data System (ADS)

Arthur, R.; Sibani, P.

2017-04-01

We discuss fitness landscapes and how they can be modified to account for co-evolution. We are interested in using the landscape as a way to model rational decision making in a toy economic system. We develop a model very similar to the Tangled Nature Model of Christensen et al. that we call the Tangled Decision Model. This is a natural setting for our discussion of co-evolutionary fitness landscapes. We use a Monte Carlo step to simulate decision making and investigate two different decision making procedures.

Undisciplined beginnings, academic success, and discursive psychology.

PubMed

Billig, Michael

2012-09-01

This paper reflects on the conditions under which Discourse and social psychology, Common knowledge, and the author's Arguing and thinking were written. These books, which were independently conceived, were not specifically written as contributions to 'discursive psychology', for discursive psychology did not exist at that time. Their authors were rejecting conventional approaches to doing psychological research. The paper discusses what it takes for a new academic movement, such as discursive psychology, to be successfully established in the current climate of 'academic capitalism'. Two requirements are particularly mentioned: the necessity for a label and the necessity for adherents to be recruited. Of the three books, only Discourse and social psychology was outwardly recruiting its readers to a new way of doing social psychology. Arguing and thinking, with its celebration of ancient rhetoric, was much more ambiguous in its aims. It was turning away from present usefulness towards the past. By claiming to be 'an antiquarian psychologist' the author was rejecting disciplinary thinking. The paper also considers the intellectual costs of establishing a new specialism or sub-discipline. The 'first generation' may have freedom, but success can bring about a narrowing of perspectives and the development of orthodoxies for subsequent academic generations. This applies as much to the development of experimental social psychology as to discursive psychology. These processes are particular enhanced in the present socio-economic situation of contemporary universities, which make it more difficult for young academics to become, in the words of William James, 'undisciplinables'. ©2012 The British Psychological Society.

Discursive constructions of youth cancer: findings from creative methods research with healthy young people.

PubMed

Mooney-Somers, Julie; Lewis, Peter; Kerridge, Ian

2016-06-01

As part of work to understand the experiences of young people who had cancer, we were keen to examine the perspectives of peers who share their social worlds. Our study aimed to examine how cancer in young people, young people with cancer and young cancer survivors are represented through language, metaphor and performance. We generated data using creative activities and focus group discussions with three high school drama classes and used Foucauldian discourse analysis to identify the discursive constructions of youth cancer. Our analysis identified two prevailing discursive constructions: youth cancer as an inevitable decline towards death and as overwhelming personhood by reducing the young person with cancer to 'cancer victim'. If we are to understand life after cancer treatment and how to support young people who have been treated for cancer, we need a sophisticated understanding of the social contexts they return to. Discourses shape the way young people talk and think about youth cancer; cancer as an inevitable decline towards death and as overwhelming personhood is a key discursive construction that young people draw on when a friend discloses cancer. The way cancer is constructed shapes how friends react to and relate to a young person with cancer. These constructions are likely to shape challenging social dynamics, such as bullying, that many young cancer survivors experience. Awareness of these discursive constructions can better equip young cancer survivors, their family and health professionals negotiate life after cancer.

Motor cortex embeds muscle-like commands in an untangled population response

PubMed Central

Russo, Abigail A.; Bittner, Sean R.; Perkins, Sean M.; Seely, Jeffrey S.; London, Brian M.; Lara, Antonio H.; Miri, Andrew; Marshall, Najja J.; Kohn, Adam; Jessell, Thomas M.; Abbott, Laurence F.; Cunningham, John P.; Churchland, Mark M.

2018-01-01

Summary Primate motor cortex projects to spinal interneurons and motor neurons, suggesting that motor cortex activity may be dominated by muscle-like commands. Extensive observations during reaching lend support to this view, but evidence remains ambiguous and much-debated. To provide a different perspective, we employed a novel behavioral paradigm that affords extensive comparison between time-evolving neural and muscle activity. We found that single motor cortex neurons displayed many muscle-like properties, but the structure of population activity was not muscle-like. Unlike muscle activity, neural activity was structured to avoid ‘tangling’: moments where similar activity patterns led to dissimilar future patterns. Avoidance of tangling was present across tasks and species. Network models revealed a potential reason for this consistent feature: low tangling confers noise robustness. Finally, we were able to predict motor cortex activity from muscle activity alone, by leveraging the hypothesis that muscle-like commands are embedded in additional structure that yields low tangling. PMID:29398358

Memory complaints are related to Alzheimer disease pathology in older persons.

PubMed

Barnes, L L; Schneider, J A; Boyle, P A; Bienias, J L; Bennett, D A

2006-11-14

To study the relationship between Alzheimer disease (AD) pathology and memory complaints proximate to death. A group of 90 older persons underwent detailed clinical evaluations and brain autopsy at death. The evaluations included administration of questions on subjective memory complaints and clinical classification of dementia and AD. On postmortem examination, neuritic plaques, diffuse plaques, and neurofibrillary tangles in tissue samples from five cortical regions were counted, and a summary measure of overall AD pathology was derived. In addition, amyloid load and tau tangles were quantified in eight regions. In multiple linear regression models adjusted for age, sex, and education, memory complaints were associated with AD pathology, including both amyloid and tau tangles. Subsequent analyses demonstrated that the relationship between memory complaints and AD pathology was present in those with and without dementia, and could not be explained by the potentially confounding effects of depressive symptoms or coexisting common chronic health problems. Memory complaints in older persons may indicate self awareness of a degenerative process.

A Note on the Propagation of Quantized Vortex Rings Through a Quantum Turbulence Tangle: Energy Transport or Energy Dissipation?

NASA Astrophysics Data System (ADS)

Laurie, Jason; Baggaley, Andrew W.

2015-07-01

We investigate quantum vortex ring dynamics at scales smaller than the inter-vortex spacing in quantum turbulence. Through geometrical arguments and high-resolution numerical simulations, we examine the validity of simple estimates for the mean free path and the structure of vortex rings post-reconnection. We find that a large proportion of vortex rings remain coherent objects where approximately of their energy is preserved. This leads us to consider the effectiveness of energy transport in turbulent tangles. Moreover, we show that in low density tangles, appropriate for the ultra-quantum regime, ring emission cannot be ruled out as an important mechanism for energy dissipation. However at higher vortex line densities, typically associated with the quasi-classical regime, loop emission is expected to make a negligible contribution to energy dissipation, even allowing for the fact that our work shows rings can survive multiple reconnection events. Hence the Kelvin wave cascade seems the most plausible mechanism leading to energy dissipation.

Magnetospheric Multiscale Satellites Observations of Parallel Electric Fields Associated with Magnetic Reconnection

NASA Technical Reports Server (NTRS)

Ergun, R. E.; Goodrich, K. A.; Wilder, F. D.; Holmes, J. C.; Stawarz, J. E.; Eriksson, S.; Sturner, A. P.; Malaspina, D. M.; Usanova, M. E.; Torbert, R. B.;

Tangle-Free Finite Element Mesh Motion for Ablation Problems

NASA Technical Reports Server (NTRS)

Droba, Justin

2016-01-01

Mesh motion is the process by which a computational domain is updated in time to reflect physical changes in the material the domain represents. Such a technique is needed in the study of the thermal response of ablative materials, which erode when strong heating is applied to the boundary. Traditionally, the thermal solver is coupled with a linear elastic or biharmonic system whose sole purpose is to update mesh node locations in response to altering boundary heating. Simple mesh motion algorithms rely on boundary surface normals. In such schemes, evolution in time will eventually cause the mesh to intersect and "tangle" with itself, causing failure. Furthermore, such schemes are greatly limited in the problems geometries on which they will be successful. This paper presents a comprehensive and sophisticated scheme that tailors the directions of motion based on context. By choosing directions for each node smartly, the inevitable tangle can be completely avoided and mesh motion on complex geometries can be modeled accurately.

Cdk5: one of the links between senile plaques and neurofibrillary tangles?

PubMed

Lee, Ming-Sum; Tsai, Li-Huei

2003-04-01

The relationship between amyloid plaques and neurofibrillary tangles, the two pathologic hallmarks of Alzheimer's disease (AD), is an unknown and controversial subject. However, emerging evidence from genetic and biochemical studies suggests that accumulation of amyloid beta peptides may play a causative role in AD pathogenesis. This led to the amyloid hypothesis, which proposes that amyloid beta peptides disrupt neuronal metabolic and ionic homeostasis and cause aberrant activation of kinases and/or inhibition of phosphatases. The resulting alteration in kinase and phosphatase activities ultimately leads to hyperphosphorylation of tau and formation of neurofibrillary tangles. Cyclin-dependent kinase 5 (Cdk5) is a tau kinase whose activity is induced by amyloid beta peptides. Its deregulation may represent one of the signal transduction pathways that connect amyloid beta toxicity to tau hyperphosphorylation. This article reviews the functions and regulation of Cdk5. Evidence that suggests deregulation of Cdk5 activity in AD by virtue of calpain cleavage of its activator p35 to p25 will be discussed.

Magnetospheric Multiscale Satellites Observations of Parallel Electric Fields Associated with Magnetic Reconnection.

PubMed

Ergun, R E; Goodrich, K A; Wilder, F D; Holmes, J C; Stawarz, J E; Eriksson, S; Sturner, A P; Malaspina, D M; Usanova, M E; Torbert, R B; Lindqvist, P-A; Khotyaintsev, Y; Burch, J L; Strangeway, R J; Russell, C T; Pollock, C J; Giles, B L; Hesse, M; Chen, L J; Lapenta, G; Goldman, M V; Newman, D L; Schwartz, S J; Eastwood, J P; Phan, T D; Mozer, F S; Drake, J; Shay, M A; Cassak, P A; Nakamura, R; Marklund, G

2016-06-10

We report observations from the Magnetospheric Multiscale satellites of parallel electric fields (E_{∥}) associated with magnetic reconnection in the subsolar region of the Earth's magnetopause. E_{∥} events near the electron diffusion region have amplitudes on the order of 100  mV/m, which are significantly larger than those predicted for an antiparallel reconnection electric field. This Letter addresses specific types of E_{∥} events, which appear as large-amplitude, near unipolar spikes that are associated with tangled, reconnected magnetic fields. These E_{∥} events are primarily in or near a current layer near the separatrix and are interpreted to be double layers that may be responsible for secondary reconnection in tangled magnetic fields or flux ropes. These results are telling of the three-dimensional nature of magnetopause reconnection and indicate that magnetopause reconnection may be often patchy and/or drive turbulence along the separatrix that results in flux ropes and/or tangled magnetic fields.

Persistent tangled vortex rings in generic excitable media.

PubMed

Winfree, A T

1994-09-15

Excitable media are exemplified by a range of living systems, such as mammalian heart muscle and its cells and Xenopus eggs. They also occur in non-living systems such as the autocatalytic Belousov-Zhabotinsky reaction. In most of these systems, activity patterns, such as concentration waves, typically radiate as spiral waves from a vortex of excitation created by some nonuniform stimulus. In three-dimensional systems, the vortex is commonly a line, and these vortex lines can form linked and knotted rings which contract into compact, particle-like bundles. In most previous work these stable 'organizing centres' have been found to be symmetrical and can be classified topologically. Here I show through numerical studies of a generic excitable medium that the more general configuration of vortex lines is a turbulent tangle, which is robust against changes in the parameters of the system or perturbations to it. In view of their stability, I suggest that these turbulent tangles should be observable in any of the many known excitable media.

Rapunzel Loves Merida: Melodramatic Expressions of Lesbian Girlhood and Teen Romance in Tangled, Brave, and Femslash.

PubMed

Kapurch, Katie

2015-01-01

This article explores the melodramatic expression of lesbian girlhood and teen romance in Disney's Tangled (2010) and Disney Pixar's Brave (2012), as well as "Meripunzel" femslash, fan-authored romantic pairings of the animations' female protagonists. First, Anne Sexton's poem, "Rapunzel," offers a literary precedent for exploring lesbian themes in the fairy tale. The next section shows how Tangled and Brave invoke the narrative conventions of the family melodrama. This generic association reveals the films' uses of rhetoric familiar to youth coming-out narratives, as well as other visual and aural coding suggestive of queer styles. The last section shows how Meripunzel femslash taps into the films' existing melodramatic narrative forms and visual aesthetics, rehearsing their coming-out rhetoric while addressing the pleasures of and problems facing lesbian teen romance. I conclude by problematizing the often conventional expressions of lesbian girlhood in femslash, ultimately arguing for their empowering potential, especially as they indicate revised definitions of "princess."

The Discursive Constitution of the UK Alcohol Problem in "Safe, Sensible, Social": A Discussion of Policy Implications

ERIC Educational Resources Information Center

Hackley, Chris; Bengry-Howell, Andrew; Griffin, Christine; Mistral, Willm; Szmigin, Isabelle

2008-01-01

In this article, we critically reflect on the constitution of the UK's alcohol problem in the government's "Safe, Social, Sensible" policy document, referring to findings from a 3-year ESRC funded study on young people, alcohol and identity. We suggest that discursive themes running throughout "Safe, Sensible, Social" include…

Changing Teachers' Practices through Exploratory Talk in Mathematics: A Discursive Pedagogical Perspective

ERIC Educational Resources Information Center

Murphy, Carol

2015-01-01

This paper presents data collected as part of an intervention research project to develop exploratory talk and collaborative group work with six and seven year-old students in mathematics. A discursive approach was used to analyse and interpret variations in the way that three case-study teachers, involved in the project, managed the group work…

A Meta-Discursive Analysis of Online Comments of Chinese Netizens on Huang Xiaoming's Appropriation of English

ERIC Educational Resources Information Center

Yan, Xi

2014-01-01

This paper explores the ideologies of English in China through a meta-discursive analysis of Chinese netizens' comments on the performance of English by Huang Xiaoming, a famous Chinese actor. By applying Park and Wee's framework for analysing ideological evaluations of appropriation (i.e. ideologies of allegiance, competence, and authenticity) to…

Interrupting Gendered Discursive Practices in Classroom Talk About Texts: Easy To Think About, Difficult To Do.

ERIC Educational Resources Information Center

Alvermann, Donna E.; Commeyras, Michelle; Young, Josephine P.; Randall, Sally; Hinson, David

1997-01-01

Focuses on university- and school-based teacher researchers attempting to alter or interrupt certain gendered discursive practices that threatened to reproduce some of the same inequities in classroom talk about texts that were noted in the past, but were not challenged. Finds four types of interactions: self-deprecating, discriminatory, and…

Rubrics and Reflection: A Discursive Analysis of Observation Debrief Conversations between Novice Teach for America Teachers and Mentors

ERIC Educational Resources Information Center

Gabriel, Rachael

2017-01-01

Drawing upon discursive psychology as a theoretical and methodological framework, the author analyzes a set of five postobservation debrief conversations between novice teachers and their mentors. The author presents analysis and findings by highlighting how the interpretative repertoires of the rubric and protocol documents may be used to shape…

Problems in place: Using discursive social psychology to investigate the meanings of seasonal homes

Treesearch

Susan R. Van Patten; Daniel R. Williams

2008-01-01

Researchers continue to explore the nature of place meanings and especially how these meanings are created, disseminated and contested. This paper uses the conceptual framework of discursive social psychology to identify varying interpretive frames homeowners use to characterize the meaning and significance of their seasonal homes as vacation and recreation residences...

Chapter One: What Is Discursive Practice?

ERIC Educational Resources Information Center

Young, Richard F.

2008-01-01

Practice is not meant to be understood as the opposite of theory, DeKeyser wrote; instead, practice involves specific activities in an L2 that learners engage in, deliberately, with the goal of developing knowledge of and skills in the L2. In the book "Discursive Practice in Language Learning and Teaching," by "practice" the author means something…

"Being Healthy": The Discursive Construction of Health in New Zealand Children's Responses to the National Education Monitoring Project

ERIC Educational Resources Information Center

Wright, Jan; Burrows, Lisette

2004-01-01

In this paper we examine the discursive resources that year 4 and year 8 students draw on to construct meanings for health. Drawing on students' responses to tasks in the New Zealand National Monitoring Project (Crooks & Flockton, "Health & Physical Education", University of Otago Educational Assessment Research Unit, 1999) we…

The Complexity of Bodily Events through an Ethnographer's Gaze: Focusing on the Youngest Children in Preschool

ERIC Educational Resources Information Center

Rossholt, Nina

2009-01-01

This article discusses theoretical, methodological and analytical strategies for researching the material subject. The discussion relates to discursive practices in a preschool setting with children of one and two years of age, where the material subject includes both bodily and discursive practices. Using critical ethnography research, the author…

Talk in Blended-Space Speech Communities: An Exploration of Discursive Practices of a Professional Development Group

ERIC Educational Resources Information Center

Garvin, Tabitha Ann

2011-01-01

This study is an exploration of alternative teacher professional development. While using symbolic interactionism for a research lens, it characterizes the discursive practices commonly found in formal, informal, and blended-space speech communities based on the talk within a leadership-development program comprised of five female, church-based…

"It's Actually Very Normal That I'm Different". How Physically Disabled Youth Discursively Construct and Position Their Body/Self

ERIC Educational Resources Information Center

van Amsterdam, Noortje; Knoppers, Annelies; Jongmans, Marian

2015-01-01

In this paper, we explore how physically disabled youth who participate in mainstream education discursively construct and position themselves in relation to dominant discourses about sport and physicality that mark their bodies as "abnormal" and "deviant". We employ a feminist poststructuralist perspective to analyze the…

Discursive Contestations and Pluriversal Futures: A Decolonial Analysis of Educational Policies in the United Arab Emirates

ERIC Educational Resources Information Center

Aydarova, Elena

2017-01-01

Most research on global transformations in education has focused on the actions of political and economic elites. As a result, attempts to contest and subvert globally circulated policies at subnational levels have received less attention. To address this gap, this study focuses on discursive contestations around educational reforms in the United…

The Organic Foods System: Its Discursive Achievements and Prospects

ERIC Educational Resources Information Center

Nowacek, David M.; Nowacek, Rebecca S.

2008-01-01

Taking the emergence of the organic foods system as a case study, the authors aim to demonstrate both how the discursive richness of the organic foods system offers a challenge to the traditional operations of the market and how activity systems theory as understood in English studies can productively be tied to and enriched by theories of social…

"Shut up and Calculate": The Available Discursive Positions in Quantum Physics Courses

ERIC Educational Resources Information Center

Johansson, Anders; Andersson, Staffan; Salminen-Karlsson, Minna; Elmgren, Maja

2018-01-01

Educating new generations of physicists is often seen as a matter of attracting good students, teaching them physics and making sure that they stay at the university. Sometimes, questions are also raised about what could be done to increase diversity in recruitment. Using a discursive perspective, in this study of three introductory quantum…

The End of Innocence: Historiography and Representation in the Discursive Practice of LD

ERIC Educational Resources Information Center

Artiles, Alfredo J.

2004-01-01

In this article, I discuss two interrelated sets of challenges that the discursive practice of learning disability (LD) will need to address, namely, issues associated with the development of a historiography of special education and a more complex understanding of representation issues. I use social theory to address these challenges and raise…

Dipeptidyl Peptidase 10 (DPP10789): A Voltage Gated Potassium Channel Associated Protein Is Abnormally Expressed in Alzheimer's and Other Neurodegenerative Diseases

PubMed Central

Gai, Wei-Ping; Abbott, Catherine A.

2014-01-01

The neuropathological features associated with Alzheimer's disease (AD) include the presence of extracellular amyloid-β peptide-containing plaques and intracellular tau positive neurofibrillary tangles and the loss of synapses and neurons in defined regions of the brain. Dipeptidyl peptidase 10 (DPP10) is a protein that facilitates Kv4 channel surface expression and neuronal excitability. This study aims to explore DPP10789 protein distribution in human brains and its contribution to the neurofibrillary pathology of AD and other tauopathies. Immunohistochemical analysis revealed predominant neuronal staining of DPP10789 in control brains, and the CA1 region of the hippocampus contained strong reactivity in the distal dendrites of the pyramidal cells. In AD brains, robust DPP10789 reactivity was detected in neurofibrillary tangles and plaque-associated dystrophic neurites, most of which colocalized with the doubly phosphorylated Ser-202/Thr-205 tau epitope. DPP10789 positive neurofibrillary tangles and plaque-associated dystrophic neurites also appeared in other neurodegenerative diseases such as frontotemporal lobar degeneration, diffuse Lewy body disease, and progressive supranuclear palsy. Occasional DPP10789 positive neurofibrillary tangles and neurites were seen in some aged control brains. Western blot analysis showed both full length and truncated DPP10789 fragments with the later increasing significantly in AD brains compared to control brains. Our results suggest that DPP10789 is involved in the pathology of AD and other neurodegenerative diseases. PMID:25025038

Tangled nonlinear driven chain reactions of all optical singularities

NASA Astrophysics Data System (ADS)

Vasil'ev, V. I.; Soskin, M. S.

2012-03-01

Dynamics of polarization optical singularities chain reactions in generic elliptically polarized speckle fields created in photorefractive crystal LiNbO3 was investigated in details Induced speckle field develops in the tens of minutes scale due to photorefractive 'optical damage effect' induced by incident beam of He-Ne laser. It was shown that polarization singularities develop through topological chain reactions of developing speckle fields driven by photorefractive nonlinearities induced by incident laser beam. All optical singularities (C points, optical vortices, optical diabolos,) are defined by instantaneous topological structure of the output wavefront and are tangled by singular optics lows. Therefore, they have develop in tangled way by six topological chain reactions driven by nonlinear processes in used nonlinear medium (photorefractive LiNbO3:Fe in our case): C-points and optical diabolos for right (left) polarized components domains with orthogonally left (right) polarized optical vortices underlying them. All elements of chain reactions consist from loop and chain links when nucleated singularities annihilated directly or with alien singularities in 1:9 ratio. The topological reason of statistics was established by low probability of far enough separation of born singularities pair from existing neighbor singularities during loop trajectories. Topology of developing speckle field was measured and analyzed by dynamic stokes polarimetry with few seconds' resolution. The hierarchy of singularities govern scenario of tangled chain reactions was defined. The useful space-time data about peculiarities of optical damage evolution were obtained from existence and parameters of 'islands of stability' in developing speckle fields.

Catalytic ionic hydrogenation of ketones using tungsten or molybdenum organometallic species

DOEpatents

Voges, Mark; Bullock, R. Morris

2000-01-01

The present invention is a process for the catalytic hydrogenation of ketones and aldehydes to alcohols at low temperatures and pressures using organometallic molybdenum and tungsten complexes. The functional group is selected from groups represented by the formulas R(C.dbd.O)R' and R(C.dbd.O)H, wherein R and R' are selected from hydrogen or any alkyl or aryl group. The active catalyst for the process has the form: [CpM(CO).sub.2 (PR*.sub.3) L].sup.+ A.sup.-, where Cp=.eta..sup.5 -R.sup..tangle-solidup..sub.m C.sub.5 H.sub.5-m and R.sup..tangle-solidup. represents an alkyl group or a halogen (F, Cl, Br, I) or R.sup..tangle-solidup. =OR' (where R'=H, an alkyl group or an aryl group) or R.sup..tangle-solidup. =CO.sub.2 R' (where R'=H, an alkyl group or an aryl group) and m=0 to 5; M represents a molybdenum atom or a tungsten atom; R*.sub.3 represents three hydrocarbon groups selected from a cyclohexyl group (C.sub.6 H.sub.11), a methyl group (CH.sub.3), and a phenyl group (C.sub.6 H.sub.5) and all three R* groups can be the same or different or two of the three groups can be the same; L represents a ligand; and A.sup.- represents an anion. In another embodiment, one, two or three of the R* groups can be an OR*.

Ultralow contact angle hysteresis and no-aging effects in superhydrophobic tangled nanofiber structures generated by controlling the pore size of a 99.5% aluminum foil

NASA Astrophysics Data System (ADS)

Lee, Sangmin; Hwang, Woonbong

2009-03-01

Superhydrophobic surfaces designed to improve hydrophobicity have high advancing contact angles corresponding to the Cassie state, but these surfaces also exhibit high contact angle hysteresis. We report here a simple and inexpensive method for fabricating superhydrophobic tangled nanofiber structures with ultralow contact angle hysteresis and no-aging degradation, based on a widening process. The resulting nanostructures are suitable for diverse applications including microfluidic devices for biological studies and industrial self-cleaning products for automobiles, ships and houses.

Upper bound on three-tangles of reduced states of four-qubit pure states

NASA Astrophysics Data System (ADS)

Sharma, S. Shelly; Sharma, N. K.

2017-06-01

Closed formulas for upper bounds on three-tangles of three-qubit reduced states in terms of three-qubit-invariant polynomials of pure four-qubit states are obtained. Our results offer tighter constraints on total three-way entanglement of a given qubit with the rest of the system than those used by Regula et al. [Phys. Rev. Lett. 113, 110501 (2014), 10.1103/PhysRevLett.113.110501 and Phys. Rev. Lett. 116, 049902(E) (2016)], 10.1103/PhysRevLett.116.049902 to verify monogamy of four-qubit quantum entanglement.

"Is It Really for Talking?": The Implications of Associating a Minority Language with the School

ERIC Educational Resources Information Center

Smith-Christmas, Cassie

2017-01-01

This paper examines how caregivers in a bilingual family discursively link Gaelic to a school context when interacting with Maggie, an eight year-old who is currently enrolled in Gaelic Medium Education on the Isle of Skye, Scotland. The paper argues that the caregivers achieve this discursive framing primarily through treating Gaelic as a…

English Education for Young Children in South Korea: Not Just a Collective Neurosis of English Fever!

ERIC Educational Resources Information Center

Jahng, Kyung Eun

2011-01-01

The aim of this article is to rethink English education for young children in South Korea through exploring a great variety of complex, interrelated terrains in terms of its emergence and popularity in an era of globalisation. I critically examine the relevance of discursive and non-discursive conditions derived from social, political, economic,…

Enactments of Discursive Empowerment in Narratives of Medium of Education by North Indian Women

ERIC Educational Resources Information Center

Sandhu, Priti

2010-01-01

In this study I examine how women in a north Indian city narratively construct their identities in relation to medium of education (MoE)--English only (EME), Hindi only (HME), and a combination of both. I specifically analyze how the participants discursively articulate empowerment or disempowerment while narrating stories connected to their MoEs.…

Preservice Elementary Teachers' Use of a Discursive Model of Meaning Making in the Co-Construction of Science Understanding

ERIC Educational Resources Information Center

Boyer, Elisebeth C.

2012-01-01

This research investigates how three preservice elementary teachers were prepared to teach science using a Discursive Model of Meaning Making. The research is divided into two parts. The first consists of the nature of the participants' learning experiences in a science methods course within a school-university Professional Development School…

What Do We Learn in Smethwick Village? Computer Games, Media Learning and Discursive Confusion

ERIC Educational Resources Information Center

McDougall, Julian

2007-01-01

This article presents findings from research exploring the intervention made by the introduction of computer games as an object of study in Media Studies at AS level in England. The outcome is a range of discursive data in the form of teachers and students from two English colleges talking about their experiences of this curriculum encounter. This…

Performing Academic Practice: Using the Master Class to Build Postgraduate Discursive Competences

ERIC Educational Resources Information Center

Baerenholdt, Jorgen Ole; Gregson, Nicky; Everts, Jonathan; Granas, Brynhild; Healey, Ruth L.

2010-01-01

How can we find ways of training PhD students in academic practices, while reflexively analysing how academic practices are performed? The paper's answer to this question is based on evaluations from a British-Nordic master class. The paper discusses how master classes can be used to train the discursive skills required for academic discussion,…

"Us" and "Them": The Discursive Construction of "the Other" in Greenmarket Square, Cape Town

ERIC Educational Resources Information Center

Dyers, Charlyn; Wankah, Foncha John

2012-01-01

This paper is based on research done on intercultural communication at Greenmarket Square in the heart of Cape Town, South Africa. The Square is well known as a market for informal traders (mainly from other parts of Africa), local people and tourists from all over the world. Using originally collected discursive evidence from market traders, the…

Cyber-Communic@tion Etiquette: The Interplay between Social Distance, Gender and Discursive Features of Student-Faculty Email Interactions

ERIC Educational Resources Information Center

Boshrabadi, Abbas Mehrabi; Sarabi, Sepideh Bataghva

2016-01-01

Purpose: Research has shown that the discursive patterns students use in their email interactions with their teachers are not linguistically and socio-culturally appropriate. Accordingly, the purpose of this paper is to try to explore how socio-cultural conventions influence the Iranian English as a foreign language (EFL) learners' choices of…

Spaces for Geometric Work: Figural, Instrumental, and Discursive Geneses of Reasoning in a Technological Environment

ERIC Educational Resources Information Center

Gómez-Chacón, Inés Ma; Kuzniak, Alain

2015-01-01

The main goal of this research was to assess the effect of a dynamic environment on relationships between the three geneses (figural, instrumental, and discursive) of Spaces for Geometric Work. More specifically, it was to determine whether the interactive geometry program GeoGebra could play a specific role in the geometric work of future…

Achieving Ethnic Minority Students’ Inclusion: A Flemish School’s Discursive Practices Countering the Quasi-Market Pressure to Exclude

ERIC Educational Resources Information Center

Zanoni, Patrizia; Mampaey, Jelle

2013-01-01

The purpose of this paper is to identify how ethnically diverse schools can discursively maintain a good reputation. Reputation allows attracting the mixed student population necessary to achieve inclusion or closing the gap between the attainment of ethnic majority and minority students. In semi-market educational systems where students are free…

Men's experiences of sexuality after cancer: a material discursive intra-psychic approach.

PubMed

Gilbert, Emilee; Ussher, Jane M; Perz, Janette; Wong, W K Tim; Hobbs, Kim; Mason, Catherine

2013-01-01

Men can experience significant changes to their sexuality following the onset of cancer. However, research on men's sexuality post-cancer has focused almost exclusively on those with prostate and testicular cancer, despite evidence that the diagnosis and treatment for most cancers can impact on men's sexuality. This Australian qualitative study explores the experiences of changes to sexuality for 21 men across a range of cancer types and stages, sexual orientations and relationship contexts. Semi-structured interviews were analysed with theoretical thematic analysis guided by a material discursive intra-psychic approach, recognising the materiality of sexual changes, men's intrapsychic experience of such changes within a relational context and the influence of the discursive construction of masculine sexuality. Material changes included erectile difficulty, decreased desire, and difficulty with orgasm. The use of medical aids to minimise the impact of erectile difficulties was shaped by discursive constructions of 'normal' masculine sexuality. The majority of men reported accepting the changes to their sexuality post-cancer and normalised them as part of the natural ageing process. Men's relationship status and context played a key role managing the changes to their sexuality. We conclude by discussing the implications for clinical practice.

Writing Prozāk Diaries in Tehran: Generational Anomie and Psychiatric Subjectivities.

PubMed

Behrouzan, Orkideh

2015-09-01

I explore the historical and cultural shifts that underlie the normalization of the term dépréshen and the emergence of public psychiatric discourses in 1990s Iran. I do this by investigating the cultural sensibilities of a particular generation, the self-identified 1980s generation, and the ways they situate what is perceived as dépréshen in social anomie and the memories of the Iran-Iraq war. I argue that psychiatrization of psychological distress in Iran was not simply a de-politicizing hegemonic biomedical discourse, but that the contemporary Iranian discourses of psychological pathology and social loss evolved in public, hand-in-hand, through the medicalization of post-war loss. Psychiatric subjectivity describes conditions where individuals internalize psychiatry as a mode of thinking, and performatively articulate not only their desires, hopes, and anxieties, but also historical losses as embodied in individual and collective brains. I underscore my interlocutors' simultaneous historicization and medicalization of their dépréshen, arguing that psychiatrically medicalized individuals are performative actors in the discursive formation of both biomedical and social truth. Dépréshen, in the larger sense of the word, has become one way to navigate ruptured pasts, slippery presents, and uncertain futures.

“End-Stage” Neurofibrillary Tangle Pathology in Preclinical Alzheimer's Disease: Fact or Fiction?

PubMed Central

Abner, Erin L.; Kryscio, Richard J.; Schmitt, Frederick A.; SantaCruz, Karen S.; Jicha, Gregory A.; Lin, Yushun; Neltner, Janna M.; Smith, Charles D.; Van Eldik, Linda J.; Nelson, Peter T.

2011-01-01

Among individuals who were cognitively intact before death, autopsies may reveal some Alzheimer's disease-type pathology. The presence of end-stage pathology in cognitively intact persons would support the hypothesis that pathological markers are epiphenomena. We assessed advanced neurofibrillary (Braak stages V and VI) pathology focusing on nondemented individuals. Data from the National Alzheimer's Coordinating Center database (n = 4,690 included initially) and from the Nun Study (n = 526 included initially) were analyzed, with antemortem information about global cognition and careful postmortem studies available from each case. Global cognition (final Mini-Mental State Examination scores [MMSE] and clinical ‘dementia’ status) was correlated with neuropathology, including the severity of neurofibrillary pathology (Braak stages and neurofibrillary tangle counts in cerebral neocortex). Analyses support three major findings: 1. Braak stage V cases and Braak VI cases are significantly different from each other in terms of associated antemortem cognition; 2. There is an appreciable range of pathology within the category of Braak stage VI based on tangle counts such that brains with the most neurofibrillary tangles in neocortex always had profound antemortem cognitive impairment; and 3. There was no nondemented case with final MMSE score of 30 within a year of life and Braak stage VI pathology. It may be inappropriate to combine Braak stages V and VI cases, particularly in patients with early cognitive dysfunction, since the two pathological stages appear to differ dramatically in terms of both pathological severity and antemortem cognitive status. There is no documented example of truly end-stage neurofibrillary pathology coexisting with intact cognition. PMID:21471646

Discursive Silences: Using Critical Linguistic and Qualitative Analysis to Explore the Continued Absence of Pleasure in Sex and Relationships Education in England

ERIC Educational Resources Information Center

Sundaram, Vanita; Sauntson, Helen

2016-01-01

In this paper, we present an analysis of "pleasure" in sex and relationships education (SRE) in England. Drawing together two distinct sources of data and different but complementary analytical frameworks, we argue that pleasure is largely absent within SRE and that this discursive silence serves to produce highly gendered and…

Discursive Mechanisms and Human Agency in Language Policy Formation: Negotiating Bilingualism and Parallel Language Use at a Swedish University

ERIC Educational Resources Information Center

Källkvist, Marie; Hult, Francis M.

2016-01-01

In the wake of the enactment of Sweden's Language Act in 2009 and in the face of the growing presence of English, Swedish universities have been called upon by the Swedish Higher Education Authority to craft their own language policy documents. This study focuses on the discursive negotiation of institutional bilingualism by a language policy…

The Interactional Accomplishment of Not Knowing in Elementary School Science and Mathematics: Implications for Classroom Performance Assessment Practices

ERIC Educational Resources Information Center

Reis, Giuliano; Barwell, Richard

2013-01-01

The day-to-day business of being a science or mathematics teacher involves the continuous assessment of students. This, in turn, is an inherently discursive process. The aim of the present study is to examine some of the specific discursive practices through which science and mathematics knowing is jointly produced through classroom interaction.…

"'I Don't Care What's under Your Clothes": The Discursive Positioning of Educators Working with Trans and Gender-Nonconforming Students

ERIC Educational Resources Information Center

Frohard-Dourlent, Hélène

2016-01-01

This paper examines the meanings educators produce about their experiences working with trans and gender-nonconforming students, and the effects of this discursive process. In this paper, I draw on 62 interviews with school staff conducted in British Columbia to examine how educators understand their role in an institutional context (a school)…

Homophobic Slurs and Public Apologies: The Discursive Struggle over "Fag/Maricon" in Public Discourse

ERIC Educational Resources Information Center

Cashman, Holly R.

2012-01-01

A handful of recent incidents hints at an ideological struggle over the use of the English word "fag(got)" and the Spanish word "maricon" in public discourse. This article examines the discursive and ideological struggle over the terms through the comparison of two cases in which Spanish/English bilingual Latinos in the U. S. use what might be…

Universal statistics of vortex tangles in three-dimensional random waves

NASA Astrophysics Data System (ADS)

Taylor, Alexander J.

2018-02-01

The tangled nodal lines (wave vortices) in random, three-dimensional wavefields are studied as an exemplar of a fractal loop soup. Their statistics are a three-dimensional counterpart to the characteristic random behaviour of nodal domains in quantum chaos, but in three dimensions the filaments can wind around one another to give distinctly different large scale behaviours. By tracing numerically the structure of the vortices, their conformations are shown to follow recent analytical predictions for random vortex tangles with periodic boundaries, where the local disorder of the model ‘averages out’ to produce large scale power law scaling relations whose universality classes do not depend on the local physics. These results explain previous numerical measurements in terms of an explicit effect of the periodic boundaries, where the statistics of the vortices are strongly affected by the large scale connectedness of the system even at arbitrarily high energies. The statistics are investigated primarily for static (monochromatic) wavefields, but the analytical results are further shown to directly describe the reconnection statistics of vortices evolving in certain dynamic systems, or occurring during random perturbations of the static configuration.

“All of Those Things We Don't Eat”: A Culture-Centered Approach to Dietary Health Meanings for Asian Indians Living in the United States

PubMed Central

Koenig, Christopher J.; Dutta, Mohan J.; Kandula, Namratha; Palaniappan, Latha

2015-01-01

This article applies a culture-centered approach to analyze the dietary health meanings for Asian Indians living in the United States. The data were collected as part of a health promotion program evaluation designed to help Asian Indians reduce their risk of chronic disease. Community members who used two aspects of the program participated in two focus groups to learn about their health care experiences and to engage them in dialogue about how culture impacts their overall health. Using constructionist grounded theory, we demonstrate that one aspect of culture, the discourses around routine dietary choice, is an important, but under-recognized, aspect of culture that influences community members’ experiences with health care. We theorize community members’ dietary health meanings operate discursively through a dialectic tension between homogeneity and heterogeneity, situated amid culture, structure, and agency. Participants enacted discursive homogeneity when they affirmed dietary health meanings around diet as an important means through which members of the community maintain a sense of continuity of their identity while differentiating them from others. Participants enacted discursive heterogeneity when they voiced dietary health meanings that differentiated community members from one another due to unique life-course trajectories and other membership affiliations. Through this dialectic, community members manage unique Asian Indian identities and create meanings of health and illness in and through their discourses around routine dietary choice. Through making these discursive health meanings audible, we foreground how community members’ agency is discursively enacted and to make understandable how discourses of dietary practice influence the therapeutic alliance between primary care providers and members of a minority community. PMID:22364189

"All of those things we don't eat": a culture-centered approach to dietary health meanings for Asian Indians living in the United States.

PubMed

Koenig, Christopher J; Dutta, Mohan J; Kandula, Namratha; Palaniappan, Latha

2012-01-01

This article applies a culture-centered approach to analyze the dietary health meanings for Asian Indians living in the United States. The data were collected as part of a health promotion program evaluation designed to help Asian Indians reduce their risk of chronic disease. Community members who used two aspects of the program participated in two focus groups to learn about their health care experiences and to engage them in dialogue about how culture impacts their overall health. Using constructionist grounded theory, we demonstrate that one aspect of culture, the discourses around routine dietary choice, is an important, but underrecognized, aspect of culture that influences community members' experiences with health care. We theorize community members' dietary health meanings operate discursively through a dialectic tension between homogeneity and heterogeneity, situated amid culture, structure, and agency. Participants enacted discursive homogeneity when they affirmed dietary health meanings around diet as an important means through which members of the community maintain a sense of continuity of their identity while differentiating them from others. Participants enacted discursive heterogeneity when they voiced dietary health meanings that differentiated community members from one another due to unique life-course trajectories and other membership affiliations. Through this dialectic, community members manage unique Asian Indian identities and create meanings of health and illness in and through their discourses around routine dietary choice. Through making these discursive health meanings audible, we foreground how community members' agency is discursively enacted and to make understandable how discourses of dietary practice influence the therapeutic alliance between primary care providers and members of a minority community.

'My sexual self, I stifled it': sexual subjectivities among young Portuguese women.

PubMed

Costa, Cecía; Nogueira, Conceição; López, Félix

2009-05-01

Recent research has examined young women's sexual subjectivities and desires, yet has neglected the ways women in their twenties account for their sexual selves. The present study focuses on the discourses and discursive constructions available for young Portuguese women when talking about their sexual subjectivity. Data were collected through six focus group discussions with young Portuguese women. The goal was to analyse discursive constructions and their potential implications for sexual empowerment and resistance. In the course of the work, it was possible to identify several different discursive devices, the most pervasive of which were Pandora's Box, Protocol and Process. Each of these constructions tended to be negative or contain negative judgements about women's sexuality. Even in contexts where a positive discourse on women's sexual desires emerged, significant constraints were encountered in achieving of a fulfilling and positive sexual experience.

Socio-environmental cooperation and conflict? A discursive understanding and its application to the case of Israel and Palestine

NASA Astrophysics Data System (ADS)

Ide, T.; Fröhlich, C.

2015-10-01

The existing literature faces difficulties when accounting for the simultaneity of socio-environmental conflict and cooperation. We suggest that this puzzle can be solved by more recent constructivist works, which argue that conflictive or cooperative behavior is driven by discursively constructed interests, identities and situation assessments. Based on a literature review and field interviews, we analyze and compare the dominant water discourses in Israel and Palestine with the discourse dominant among the activists of a water cooperation project between communities from Israel and the West Bank. Our main result is that discourses are indeed crucial for understanding water-related conflict and cooperation. This finding highlights the relevance of constructivist approaches in the study of socio-environmental conflict and cooperation as well as of practices of bottom-up discursive conflict transformation.

Visualizing Pure Quantum Turbulence in Superfluid 3He: Andreev Reflection and its Spectral Properties.

PubMed

Baggaley, A W; Tsepelin, V; Barenghi, C F; Fisher, S N; Pickett, G R; Sergeev, Y A; Suramlishvili, N

2015-07-03

Superfluid 3He-B in the zero-temperature limit offers a unique means of studying quantum turbulence by the Andreev reflection of quasiparticle excitations by the vortex flow fields. We validate the experimental visualization of turbulence in 3He-B by showing the relation between the vortex-line density and the Andreev reflectance of the vortex tangle in the first simulations of the Andreev reflectance by a realistic 3D vortex tangle, and comparing the results with the first experimental measurements able to probe quantum turbulence on length scales smaller than the intervortex separation.

Tempo and mode of evolution in the tangled nature model.

PubMed

Jones, Dominic; Jensen, Henrik Jeldtoft; Sibani, Paolo

2010-09-01

The fossil record has been interpreted as exhibiting a gradual decrease in the extinction rate. We use the individual based Tangled Nature model of evolutionary ecology to study the mechanisms behind this kind of nonstationary macrodynamics. We demonstrate that the long time aging in the system (manifested as a slowing down of the rate of large jumps, or quakes, that the system undergoes) is related to decreasing fluctuations in the offspring probability. The scenario is reminiscent of relaxation in a quenched spin glass but purely dynamical in nature since no energy barriers can be defined.

Oh what a tangled web it weaves: BRCA1 and DNA decatenation.

PubMed

Ashworth, Alan

2005-08-01

BRCA1 has significant roles in DNA repair and cell cycle checkpoint control, and is important in the maintenance of genomic stability. Defects in these pathways likely underpin the cancer susceptibility of BRCA1 mutation carriers. Now, a new function for BRCA1 in DNA decatenation--removing the tangles introduced into chromosomes as a consequence of DNA replication--is suggested in a new paper by Lou et al. (2005) in Nature Structural and Molecular Biology. Ineffective DNA decatenation may lead to chromosome breakage and inappropriate repair, adding to the roll call of defects in BRCA1 mutant cells.

Holocene pollen and sediment record from the tangle lakes area, central Alaska

USGS Publications Warehouse

Ager, Thomas A.; Sims, John D.

1981-01-01

Pollen and sediments have been analyzed from a 5.5 meter‐length core of lacustrine sediments from Tangle Lakes, in the Gulkana Upland south of the Alaska Range (63 ° 01 ‘ 46”; N. latitude, 146° 03 ‘ 48 “ W. longitude). Radiocarbon ages indicate that the core spans the last 4700 years. The core sediments are sandy silt and silty clay; the core shows distinct rhythmic laminations in the lower 398 cm. The laminae appear to be normally graded; peat fibers and macerated plant debris are more abundant near the tops of the laminae. Six volcanic‐ash layers are present in the upper 110 cm of the core.Present‐day vegetation of the Tangle Lakes area is mesic shrub tundra and open spruce woodland, with scattered patches of shrub willow (Salix), balsam poplar (P. balsamifera), spruce (Picea), paper birch (Betula papyrifera), and alder (Alnus). Pollen analysis of 27 core samples suggests that this vegetation type has persisted throughout the past 4700 years, except for an apparently substantial increase in Picea beginning about 3500 years B.P. Percentages of Picea pollen are very low (generally 1–3 percent) in the lower 2 meters of core (ca. 4700 to 3500 years B.P.), but rise to 13–18 percent in the upper 3.4 meters (ca. 3500 years B.P. to present). Previously reported data from this area indicate that Picea trees initially arrived in the Tangle Lakes area about 9100 years B.P., at least 2.5 to 3 thousand years after deglaciation of the region. The present investigation suggests that Picea trees became locally scarce or died out sometime after about 9000 years B.P. but before 4700 years B.P., then reinvaded the area about 3500 years B.P. If this extrapolated age for the Picea reinvasion is accurate it suggests that local expansion of the Picea population coincides with the onset of a Neoglacial interval of cooler, moister climate. This is an unexpected result, because intervals of cooler climate generally coincide with lowering of the altitudinal limit of trees. In this case, improved moisture conditions may have promoted spruce growth and reproduction in spite of somewhat cooler temperatures.Previous pollen records from Alaska suggest that Artemisia pollen contributed little to the pollen rain of most taiga and tundra sites during Holocene time. The pollen record from Tangle Lakes, however shows rather high percentages (7–13 percent) of Artemisia deposited during the approximate time interval 4700 to 3500 years B.P. Local habitats that have well‐drained soils derived from glacial deposits support patches of Artemisia telesii and other Artemisia species. These local habitats may account for the source of Artemisiapollen deposited in the Tangle Lakes area during Holocene time.

In and out of Place: Exploring the Discursive Effects of Teachers' Talk about Outdoor Education in Secondary Schools in New Zealand

ERIC Educational Resources Information Center

Mikaels, Jonas; Backman, Erik; Lundvall, Suzanne

2016-01-01

The purpose of this article is to explore and problematise teachers' talk about outdoor education in New Zealand. The focus is on what can be said, how it is said and the discursive effects of such ways of speaking. The inquiry draws on Foucauldian theoretical insights to analyse interview transcripts derived from semi-structured interviews with…

"You've Got to Teach People that Racism Is Wrong and Then They Won't Be Racist": Curricular Representations and Young People&'s Understandings of "Race" and Racism

ERIC Educational Resources Information Center

Bryan, Audrey

2012-01-01

This paper critically examines the discursive (mis) representation of "race" and racism in the formal curriculum. Combining qualitative data derived from interviews with 35 young people who were enrolled in a Dublin-based, ethnically diverse secondary school, with a critical discursive analysis of 20 textbooks, the paper explores…

Contesting the 'national interest' and maintaining 'our lifestyle': a discursive analysis of political rhetoric around climate change.

PubMed

Kurz, Tim; Augoustinos, Martha; Crabb, Shona

2010-09-01

The release of the fourth United Nations Intergovernmental Panel on Climate Change (IPCC) report in February 2007 prompted a flood of responses from political leaders around the globe. Perhaps nowhere was this more apparent than in Australia, where its release coincided with the first sitting week of the Australian Parliament, in an election year. The current study involves a discursive analysis of climate change rhetoric produced by politicians from the major Australian political parties in the period following the release of the IPCC leading up to the national election. Data include both transcripts of parliamentary debate and statements directly broadcast in the media. The analysis focuses on the various ways in which the issue of climate change was invoked and rhetorically managed by each of the two parties in the lead up to the election. In particular, it focuses on the ways in which appeals to the 'national interest' and 'lifestyle maintenance', both regular features of political rhetoric, were mobilized by both parties to discursively manage their positions on the climate change issue. Implications of the ways in which such appeals were constructed are discussed in relation to the discursive limits of the ways in which the issue of climate change is constructed in public debate.

A three-dimensional human neural cell culture model of Alzheimer's disease.

PubMed

Choi, Se Hoon; Kim, Young Hye; Hebisch, Matthias; Sliwinski, Christopher; Lee, Seungkyu; D'Avanzo, Carla; Chen, Hechao; Hooli, Basavaraj; Asselin, Caroline; Muffat, Julien; Klee, Justin B; Zhang, Can; Wainger, Brian J; Peitz, Michael; Kovacs, Dora M; Woolf, Clifford J; Wagner, Steven L; Tanzi, Rudolph E; Kim, Doo Yeon

2014-11-13

Alzheimer's disease is the most common form of dementia, characterized by two pathological hallmarks: amyloid-β plaques and neurofibrillary tangles. The amyloid hypothesis of Alzheimer's disease posits that the excessive accumulation of amyloid-β peptide leads to neurofibrillary tangles composed of aggregated hyperphosphorylated tau. However, to date, no single disease model has serially linked these two pathological events using human neuronal cells. Mouse models with familial Alzheimer's disease (FAD) mutations exhibit amyloid-β-induced synaptic and memory deficits but they do not fully recapitulate other key pathological events of Alzheimer's disease, including distinct neurofibrillary tangle pathology. Human neurons derived from Alzheimer's disease patients have shown elevated levels of toxic amyloid-β species and phosphorylated tau but did not demonstrate amyloid-β plaques or neurofibrillary tangles. Here we report that FAD mutations in β-amyloid precursor protein and presenilin 1 are able to induce robust extracellular deposition of amyloid-β, including amyloid-β plaques, in a human neural stem-cell-derived three-dimensional (3D) culture system. More importantly, the 3D-differentiated neuronal cells expressing FAD mutations exhibited high levels of detergent-resistant, silver-positive aggregates of phosphorylated tau in the soma and neurites, as well as filamentous tau, as detected by immunoelectron microscopy. Inhibition of amyloid-β generation with β- or γ-secretase inhibitors not only decreased amyloid-β pathology, but also attenuated tauopathy. We also found that glycogen synthase kinase 3 (GSK3) regulated amyloid-β-mediated tau phosphorylation. We have successfully recapitulated amyloid-β and tau pathology in a single 3D human neural cell culture system. Our unique strategy for recapitulating Alzheimer's disease pathology in a 3D neural cell culture model should also serve to facilitate the development of more precise human neural cell models of other neurodegenerative disorders.

Fine tangled pili expressed by Haemophilus ducreyi are a novel class of pili.

PubMed Central

Brentjens, R J; Ketterer, M; Apicella, M A; Spinola, S M

1996-01-01

Haemophilus ducreyi synthesizes fine, tangled pili composed predominantly of a protein whose apparent molecular weight is 24,000 (24K). A hybridoma, 2D8, produced a monoclonal antibody (MAb) that bound to a 24K protein in H. ducreyi strains isolated from diverse geographic locations. A lambda gt11 H. ducreyi library was screened with MAb 2D8. A 3.5-kb chromosomal insert from one reactive plaque was amplified and ligated into the pCRII vector. The recombinant plasmid, designated pHD24, expressed a 24K protein in Escherichia coli INV alpha F that bound MAb 2D8. The coding sequence of the 24K gene was localized by exonuclease III digestion. The insert contained a 570-bp open reading frame, designated ftpA (fine, tangled pili). Translation of ftpA predicted a polypeptide with a molecular weight of 21.1K. The predicted N-terminal amino acid sequence of the polypeptide encoded by ftpA was identical to the N-terminal amino acid sequence of purified pilin and lacked a cleavable signal sequence. Primer extension analysis of ftpA confirmed the lack of a leader peptide. The predicted amino acid sequence lacked homology to known pilin sequences but shared homology with the sequences of E. coli Dps and Treponema pallidum antigen TpF1 or 4D, proteins which associate to form ordered rings. An isogenic pilin mutant, H. ducreyi 35000ftpA::mTn3(Cm), was constructed by shuttle mutagenesis and did not contain pili when examined by electron microscopy. We conclude that H. ducreyi synthesizes fine, tangled pili that are composed of a unique major subunit, which may be exported by a signal sequence independent mechanism. PMID:8550517

Framework for Analysis of Mitigation in Courts

DTIC Science & Technology

2005-01-01

present a framework for a pragmatic analysis of mitigation in courts. The study focuses on discursive acts and aspects of discursive acts the purpose...use it is associated with coping (Lazarus, 1999) with (inevitable) negative events or experiences. It is also linked to studies of pragmatics...The concept of ‘hedges’ or ‘metalinguistic operators’ such as ‘more or less’, ‘like’, ‘sort of’ etc. in turn originated in studies on the fuzzy-set

Acting discursively: the development of UK organic food and farming policy networks.

PubMed

TOMLINSON, Isobel Jane

2010-01-01

This paper documents the early evolution of UK organic food and farming policy networks and locates this empirical focus in a theoretical context concerned with understanding the contemporary policy-making process. While policy networks have emerged as a widely acknowledged empirical manifestation of governance, debate continues as to the concept's explanatory utility and usefulness in situations of network and policy transformation since, historically, policy networks have been applied to "static" circumstances. Recognizing this criticism, and in drawing on an interpretivist perspective, this paper sees policy networks as enacted by individual actors whose beliefs and actions construct the nature of the network. It seeks to make links between the characteristics of the policy network and the policy outcomes through the identification of discursively constructed "storylines" that form a tool for consensus building in networks. This study analyses the functioning of the organic policy networks through the discursive actions of policy-network actors.

Standards and Stories: The Interactional Work of Informed Choice in Ontario Midwifery Care

PubMed Central

Spoel, Philippa; Mckenzie, Pamela; James, Susan; Hobberlin, Jessica

2013-01-01

This paper uses a discourse-rhetorical approach to analyze how Ontario midwives and their clients interactionally accomplish the healthcare communicative process of «informed choice.» Working with four excerpts from recorded visits between Ontario midwives and women, the analysis focuses on the discursive rendering during informed choice conversations of two contrasting kinds of evidence — professional standards and story-telling — related to potential interventions during labour. We draw on the concepts of discursive hybridity (Sarangi and Roberts 1999) and recontextualization (Linell 1998; Sarangi 1998) to trace the complex and creative ways in which the conversational participants reconstruct the meanings of these evidentiary sources to address their particular care contexts. This analysis shows how, though very different in their forms, both modes of evidence function as hybrid and flexible discursive resources that perform both instrumental and social-relational healthcare work. PMID:24289941

Anisotropic Invariance and the Distribution of Quantum Correlations.

PubMed

Cheng, Shuming; Hall, Michael J W

2017-01-06

We report the discovery of two new invariants for three-qubit states which, similarly to the three-tangle, are invariant under local unitary transformations and permutations of the parties. These quantities have a direct interpretation in terms of the anisotropy of pairwise spin correlations. Applications include a universal ordering of pairwise quantum correlation measures for pure three-qubit states; trade-off relations for anisotropy, three-tangle and Bell nonlocality; strong monogamy relations for Bell inequalities, Einstein-Podolsky-Rosen steering inequalities, geometric discord and fidelity of remote state preparation (including results for arbitrary three-party states); and a statistical and reference-frame-independent form of quantum secret sharing.

Cosmic microwave background polarization signals from tangled magnetic fields.

PubMed

Seshadri, T R; Subramanian, K

2001-09-03

Tangled, primordial cosmic magnetic fields create small rotational velocity perturbations on the last scattering surface of the cosmic microwave background radiation. For fields which redshift to a present value of B0 = 3 x 10(-9) G, these vector modes are shown to generate polarization anisotropies of order 0.1-4 microK on small angular scales (500

Anisotropic Invariance and the Distribution of Quantum Correlations

NASA Astrophysics Data System (ADS)

Cheng, Shuming; Hall, Michael J. W.

2017-01-01

We report the discovery of two new invariants for three-qubit states which, similarly to the three-tangle, are invariant under local unitary transformations and permutations of the parties. These quantities have a direct interpretation in terms of the anisotropy of pairwise spin correlations. Applications include a universal ordering of pairwise quantum correlation measures for pure three-qubit states; trade-off relations for anisotropy, three-tangle and Bell nonlocality; strong monogamy relations for Bell inequalities, Einstein-Podolsky-Rosen steering inequalities, geometric discord and fidelity of remote state preparation (including results for arbitrary three-party states); and a statistical and reference-frame-independent form of quantum secret sharing.

The role of curvature in entanglement

NASA Astrophysics Data System (ADS)

Buck, Gregory

2015-10-01

Which tangles more readily: curly hair or straight hair? A perhaps natural thought, supported by some theoretical evidence, is to associate curvature and entanglement, and assume that they would grow together-that an increase in one fosters an increase in the other. However we have biological examples such as DNA in the chromosome, and mechanical examples such as coiled telephone cords, in which much more curvature is employed than is required for the packing, and in which tangling is presumably detrimental. We offer a resolution to this conundrum. We show, that at least for simple but generally applicable models, the relationship between curvature and entanglement is subtle: if we keep filament density constant and increase curvature, the entanglement initially increases, passes through a maximum, then decreases, so there is a regime where increasing curvature increases entanglement, and there is also a regime where increasing curvature decreases entanglement. This has implications for filament packing in many circumstances, and in particular for the compaction structure of DNA in the cell-it provides a straightforward argument for the view that one purpose of DNA coiling and supercoiling is to inhibit entanglement. It also tells us to expect that wavy hair-neither the straightest nor the curliest-tangles most readily.

Stochastic local operations and classical communication (SLOCC) and local unitary operations (LU) classifications of n qubits via ranks and singular values of the spin-flipping matrices

NASA Astrophysics Data System (ADS)

Li, Dafa

2018-06-01

We construct ℓ -spin-flipping matrices from the coefficient matrices of pure states of n qubits and show that the ℓ -spin-flipping matrices are congruent and unitary congruent whenever two pure states of n qubits are SLOCC and LU equivalent, respectively. The congruence implies the invariance of ranks of the ℓ -spin-flipping matrices under SLOCC and then permits a reduction of SLOCC classification of n qubits to calculation of ranks of the ℓ -spin-flipping matrices. The unitary congruence implies the invariance of singular values of the ℓ -spin-flipping matrices under LU and then permits a reduction of LU classification of n qubits to calculation of singular values of the ℓ -spin-flipping matrices. Furthermore, we show that the invariance of singular values of the ℓ -spin-flipping matrices Ω 1^{(n)} implies the invariance of the concurrence for even n qubits and the invariance of the n-tangle for odd n qubits. Thus, the concurrence and the n-tangle can be used for LU classification and computing the concurrence and the n-tangle only performs additions and multiplications of coefficients of states.

Tangle-Free Finite Element Mesh Motion for Ablation Problems

NASA Technical Reports Server (NTRS)

Droba, Justin

2016-01-01

In numerical simulations involving boundaries that evolve in time, the primary challenge is updating the computational mesh to reflect the physical changes in the domain. In particular, the fundamental objective for any such \\mesh motion" scheme is to maintain mesh quality and suppress unphysical geometric anamolies and artifacts. External to a physical process of interest, mesh motion is an added component that determines the specifics of how to move the mesh given certain limited information from the main system. This paper develops a set of boundary conditions designed to eliminate tangling and internal collision within the context of PDE-based mesh motion (linear elasticity). These boundary conditions are developed for two- and three-dimensional meshes. The paper presents detailed algorithms for commonly occuring topological scenarios and explains how to apply them appropriately. Notably, the techniques discussed herein make use of none of the specifics of any particular formulation of mesh motion and thus are more broadly applicable. The two-dimensional algorithms are validated by an extensive verification procedure. Finally, many examples of diverse geometries in both two- and three-dimensions are shown to showcase the capabilities of the tangle-free boundary conditions.

A mitocentric view of Alzheimer's disease suggests multi-faceted treatments.

PubMed

Gibson, Gary E; Shi, Qingli

2010-01-01

Alzheimer's disease (AD) is defined by senile plaques made of amyloid-beta peptide (Abeta), neurofibrillary tangles made of hyperphosphorylated tau proteins, and memory deficits. Thus, the events initiating the cascade leading to these end points may be more effective therapeutic targets than treating each facet individually. In the small percentage of cases of AD that are genetic (or animal models that reflect this form of AD), the factor initiating AD is clear (e.g., genetic mutations lead to high Abeta1-42 or hyperphosphorylated tau proteins). In the vast majority of AD cases, the cause is unknown. Substantial evidence now suggests that abnormalities in glucose metabolism/mitochondrial function/oxidative stress (GMO) are an invariant feature of AD and occur at an early stage of the disease process in both genetic and non-genetic forms of AD. Indeed, decreases in brain glucose utilization are diagnostic for AD. Changes in calcium homeostasis also precede clinical manifestations of AD. Abnormal GMO can lead to plaques, tangles, and the calcium abnormalities that accompany AD. Abnormalities in GMO diminish the ability of the brain to adapt. Therapies targeting mitochondria may ameliorate abnormalities in plaques, tangles, calcium homeostasis, and cognition that comprise AD.

The crooked timber of identity: Integrating discursive, critical, and psychosocial analysis.

PubMed

Kaposi, David

2013-06-01

This paper seeks to contribute to the growing band of constructionist approaches within the field of identity studies (Wetherell & Moharty, 2010). First, it will review the developments that have taken place since the emergence of these approaches in the 1980s, identifying a state of fragmentation into local discursive, political-moral, and psychosocial levels of analysis. Second, and in order to challenge this fragmentation, it will present a rhetorical psychological (Billig, 1987, 1999a) analysis of the classic exchange of public letters between Israeli historian of Judaism Gershom Scholem and American political theorist Hannah Arendt in the wake of the latter's book Eichmann in Jerusalem (Arendt, 1994a). The analysis will proceed from local discursive action, through political-moral frameworks, to the nature of the writers' investment in these constructions. It will show that while the participants' implicitly occasioning of extreme identity categories (such as the 'Jewish anti-Semite' and the totalitarian-style religious Zionist ideologue) is a function of apparently incommensurable political-moral discourses, the nature of investment into such constructions may be understood in a mutual commitment to the absolute inalienability of Jewishness. Third, therefore, the paper will conclude that, rather than constituting separate 'levels', local discursive action, political-moral intelligibilities, and psychosocial qualities are mutually constitutive of each other. It is only through recognizing their inter-dependent nature that the complexity of identity may properly be addressed. ©2011 The British Psychological Society.

"Shut up and calculate": the available discursive positions in quantum physics courses

NASA Astrophysics Data System (ADS)

Johansson, Anders; Andersson, Staffan; Salminen-Karlsson, Minna; Elmgren, Maja

2018-03-01

Educating new generations of physicists is often seen as a matter of attracting good students, teaching them physics and making sure that they stay at the university. Sometimes, questions are also raised about what could be done to increase diversity in recruitment. Using a discursive perspective, in this study of three introductory quantum physics courses at two Swedish universities, we instead ask what it means to become a physicist, and whether certain ways of becoming a physicist and doing physics is privileged in this process. Asking the question of what discursive positions are made accessible to students, we use observations of lectures and problem solving sessions together with interviews with students to characterize the discourse in the courses. Many students seem to have high expectations for the quantum physics course and generally express that they appreciate the course more than other courses. Nevertheless, our analysis shows that the ways of being a "good quantum physics student" are limited by the dominating focus on calculating quantum physics in the courses. We argue that this could have negative consequences both for the education of future physicists and the discipline of physics itself, in that it may reproduce an instrumental "shut up and calculate"-culture of physics, as well as an elitist physics education. Additionally, many students who take the courses are not future physicists, and the limitation of discursive positions may also affect these students significantly.

Systematically reviewing and synthesizing evidence from conversation analytic and related discursive research to inform healthcare communication practice and policy: an illustrated guide

PubMed Central

2013-01-01

Background Healthcare delivery is largely accomplished in and through conversations between people, and healthcare quality and effectiveness depend enormously upon the communication practices employed within these conversations. An important body of evidence about these practices has been generated by conversation analysis and related discourse analytic approaches, but there has been very little systematic reviewing of this evidence. Methods We developed an approach to reviewing evidence from conversation analytic and related discursive research through the following procedures: • reviewing existing systematic review methods and our own prior experience of applying these • clarifying distinctive features of conversation analytic and related discursive work which must be taken into account when reviewing • holding discussions within a review advisory team that included members with expertise in healthcare research, conversation analytic research, and systematic reviewing • attempting and then refining procedures through conducting an actual review which examined evidence about how people talk about difficult future issues including illness progression and dying Results We produced a step-by-step guide which we describe here in terms of eight stages, and which we illustrate from our ‘Review of Future Talk’. The guide incorporates both established procedures for systematic reviewing, and new techniques designed for working with conversation analytic evidence. Conclusions The guide is designed to inform systematic reviews of conversation analytic and related discursive evidence on specific domains and topics. Whilst we designed it for reviews that aim at informing healthcare practice and policy, it is flexible and could be used for reviews with other aims, for instance those aiming to underpin research programmes and projects. We advocate systematically reviewing conversation analytic and related discursive findings using this approach in order to translate them into a form that is credible and useful to healthcare practitioners, educators and policy-makers. PMID:23721181

'Man up!' Discursive constructions of non-drinkers among UK undergraduates.

PubMed

Conroy, Dominic; de Visser, Richard

2013-11-01

This study adopted a discursive approach to explore how not drinking alcohol (non-drinking) is construed in relation to masculine identity among 12 undergraduate interviewees. Three prominent discourses were revealed. First, non-drinking was constructed as something strange requiring explanation. Second, contradictory discourses constructed non-drinking as, simultaneously, unsociable yet reflective of greater sociability. Third, non-drinking was constructed as something which has greater negative social consequences for men than for women. Opportunities for challenging traditional gender role expectations are considered.

"But at school … I became a bit shy": Korean immigrant adolescents' discursive participation in science classrooms

NASA Astrophysics Data System (ADS)

Ryu, Minjung

2013-09-01

In reform-based science curricula, students' discursive participation is highly encouraged as a means of science learning as well as a goal of science education. However, Asian immigrant students are perceived to be quiet and passive in classroom discursive situations, and this reticence implies that they may face challenges in discourse-rich science classroom learning environments. Given this potentially conflicting situation, the present study aims to understand how and why Asian immigrant students participate in science classroom discourse. Findings from interviews with seven Korean immigrant adolescents illustrate that they are indeed hesitant to speak up in classrooms. Drawing upon cultural historical perspectives on identity and agency, this study shows how immigrant experiences shaped the participants' othered identity and influenced their science classroom participation, as well as how they negotiated their identities and situations to participate in science classroom and peer communities. I will discuss implications of this study for science education research and science teacher education to support classroom participation of immigrant students.

Normalizing ideological food choice and eating practices. Identity work in online discussions on veganism.

PubMed

Sneijder, Petra; Te Molder, Hedwig

2009-06-01

In this paper we use discursive psychology to explore the relation between ideologically based food choice and identity in an online forum on veganism. The discursive psychological perspective underlines the notion of identities being part of social actions performed in talk, and thus designed and deployed for different interactional purposes. It is demonstrated that participants draw on specific discursive devices to (1) define vegan meals as ordinary and easy to prepare and (2) construct methods of preventing vitamin deficiency, such as taking supplements, as routine procedures. In 'doing being ordinary', participants systematically resist the notion that being a vegan is complicated--in other words, that it is both difficult to compose a meal and to protect your health. In this way, 'ordinariness' helps to construct and protect veganism as an ideology. We point out similarities and differences with other studies on eating or healthy lifestyles and argue, more broadly, that identities and their category-bound features are part and parcel of participants' highly flexible negotiation package.

3D printed cat tongue is a self-cleaning, tangle-teasing brush

NASA Astrophysics Data System (ADS)

Noel, Alexis; Hu, David

A cat's tongue is covered in an array of spines called papillae. These spines are thought to be used in grooming and rasping meat from bones of prey, although no mechanism has been given. We use high-speed video to film a cat grooming. We show that the spines on the tongue act as low pass filters for tangles in hair. The tongue itself is highly elastic, while the spines are rigid. We 3D print a cat tongue mimic and show that the nonlinear force applied by the spines helps to increase efficacy of grooming. The tongue also provides frictional anisotropy with backward-facing spines, allowing for self-cleaning properties post-groom.

Discursive geographies in science: space, identity, and scientific discourse among indigenous women in higher education

NASA Astrophysics Data System (ADS)

Brandt, Carol B.

2008-09-01

Despite completing undergraduate degrees in the life sciences, few Indigenous women choose to pursue careers in scientific research. To help us understand how American Indian students engage with science, this ethnographic research describes (1) how four Navajo women identified with science, and (2) the narratives they offered when we discussed their experiences with scientific discourse. Using intensive case studies to describe the experiences of these women, my research focused on their final year of undergraduate study in the life sciences at a university in southwestern US. I point to the processes by which the participants align themselves with ideas, practices, groups, or people in science. As each participant recounted her experiences with scientific discourse, they recreated for me a discursive geography of their lives on the reservation, at home, at community colleges (in some cases), and on the university campus. In the construction and analysis of the narratives for this research, mapping this geography was critical to understanding each participant's discursive relationship with science. In these discursive spaces, I observed productive "locations of possibility" in which students and their instructors: valued connected knowing; acknowledged each other's history, culture, and knowledge; began to speak to each other subject-to-subject; and challenged normative views of schooling. I argue that this space, as a location of possibility, has the power to transform the crushing impersonalized schooling that often characterizes "rigorous" scientific programs in a research institution.

Correlation of Alzheimer Disease Neuropathologic Changes With Cognitive Status: A Review of the Literature

PubMed Central

Nelson, Peter T.; Alafuzoff, Irina; Bigio, Eileen H.; Bouras, Constantin; Braak, Heiko; Cairns, Nigel J.; Castellani, Rudolph J.; Crain, Barbara J.; Davies, Peter; Del Tredici, Kelly; Duyckaerts, Charles; Frosch, Matthew P.; Haroutunian, Vahram; Hof, Patrick R.; Hulette, Christine M.; Hyman, Bradley T.; Iwatsubo, Takeshi; Jellinger, Kurt A.; Jicha, Gregory A.; Kövari, Enikö; Kukull, Walter A.; Leverenz, James B.; Love, Seth; Mackenzie, Ian R.; Mann, David M.; Masliah, Eliezer; McKee, Ann C.; Montine, Thomas J.; Morris, John C.; Schneider, Julie A.; Sonnen, Joshua A.; Thal, Dietmar R.; Trojanowski, John Q.; Troncoso, Juan C.; Wisniewski, Thomas; Woltjer, Randall L.; Beach, Thomas G.

2013-01-01

Clinicopathologic correlation studies are critically important for the field of Alzheimer disease (AD) research. Studies on human subjects with autopsy confirmation entail numerous potential biases that affect both their general applicability and the validity of the correlations. Many sources of data variability can weaken the apparent correlation between cognitive status and AD neuropathologic changes. Indeed, most persons in advanced old age have significant non-AD brain lesions that may alter cognition independently of AD. Worldwide research efforts have evaluated thousands of human subjects to assess the causes of cognitive impairment in the elderly, and these studies have been interpreted in different ways. We review the literature focusing on the correlation of AD neuropathologic changes (i.e. β-amyloid plaques and neurofibrillary tangles) with cognitive impairment. We discuss the various patterns of brain changes that have been observed in elderly individuals to provide a perspective for understanding AD clinicopathologic correlation and conclude that evidence from many independent research centers strongly supports the existence of a specific disease, as defined by the presence of Aβ plaques and neurofibrillary tangles. Although Aβ plaques may play a key role in AD pathogenesis, the severity of cognitive impairment correlates best with the burden of neocortical neurofibrillary tangles. PMID:22487856

Indexing and retrieving motions of characters in close contact.

PubMed

Ho, Edmond S L; Komura, Taku

2009-01-01

Human motion indexing and retrieval are important for animators due to the need to search for motions in the database which can be blended and concatenated. Most of the previous researches of human motion indexing and retrieval compute the Euclidean distance of joint angles or joint positions. Such approaches are difficult to apply for cases in which multiple characters are closely interacting with each other, as the relationships of the characters are not encoded in the representation. In this research, we propose a topology-based approach to index the motions of two human characters in close contact. We compute and encode how the two bodies are tangled based on the concept of rational tangles. The encoded relationships, which we define as TangleList, are used to determine the similarity of the pairs of postures. Using our method, we can index and retrieve motions such as one person piggy-backing another, one person assisting another in walking, and two persons dancing / wrestling. Our method is useful to manage a motion database of multiple characters. We can also produce motion graph structures of two characters closely interacting with each other by interpolating and concatenating topologically similar postures and motion clips, which are applicable to 3D computer games and computer animation.

Abnormal tau phosphorylation in the thorny excrescences of CA3 hippocampal neurons in patients with Alzheimer's disease.

PubMed

Blazquez-Llorca, Lidia; Garcia-Marin, Virginia; Merino-Serrais, Paula; Ávila, Jesús; DeFelipe, Javier

2011-01-01

A key symptom in the early stages of Alzheimer's disease (AD) is the loss of declarative memory. The anatomical substrate that supports this kind of memory involves the neural circuits of the medial temporal lobe, and in particular, of the hippocampal formation and adjacent cortex. A main feature of AD is the abnormal phosphorylation of the tau protein and the presence of tangles. The sequence of cellular changes related to tau phosphorylation and tangle formation has been studied with an antibody that binds to diffuse phosphotau (AT8). Moreover, another tau antibody (PHF-1) has been used to follow the pathway of neurofibrillary (tau aggregation) degeneration in AD. We have used a variety of quantitative immunocytochemical techniques and confocal microscopy to visualize and characterize neurons labeled with AT8 and PHF-1 antibodies. We present here the rather unexpected discovery that in AD, there is conspicuous abnormal phosphorylation of the tau protein in a selective subset of dendritic spines. We identified these spines as the typical thorny excrescences of hippocampal CA3 neurons in a pre-tangle state. Since thorny excrescences represent a major synaptic target of granule cell axons (mossy fibers), such aberrant phosphorylation may play an essential role in the memory impairment typical of AD patients.

Plastic Deformation Behavior of Ti Foil Under Ultrasonic Vibration in Tension

NASA Astrophysics Data System (ADS)

Jiang, Shaosong; Jia, Yong; Zhang, Hongbin; Du, Zhihao; Lu, Zhen; Zhang, Kaifeng; He, Yushi; Wang, Ruizhuo

2017-04-01

The benefits of ultrasonic vibration auxiliary metal forming have been shown by many studies. In this study, a series of experiments were carried out to investigate the deformation behavior of Ti foils under ultrasonic vibration in tension, and the tensile properties of Ti foils with/without the application of ultrasonic vibration were investigated. Then, the microstructure of different tensile samples was analyzed by transmission electron microscopy (TEM). The results of the tensile experiments showed that the tensile strength of tensile samples was reduced when ultrasonic vibration was applied, while the elongation of these samples increased. The flow stress increased with increasing strain without applying ultrasonic vibration, while it decreased steeply when the ultrasonic vibration was applied, and this reduction of flow stress demonstrated the effect of acoustic softening on the properties of the material. Additionally, the range of flow stress reduction was inversely proportional to the time for which ultrasonic vibration was applied. The TEM images showed that there were remarkable differences in dislocation distribution and tangles with/without ultrasonic vibration. The dislocation distribution was inhomogeneous, and copious dislocation tangles were discovered without ultrasonic vibration. When it was applied, the parallel re-arrangement of dislocations could be observed and the mass of dislocation tangles was mostly absent.

Tangle-Free Mesh Motion for Ablation Simulations

NASA Technical Reports Server (NTRS)

Droba, Justin

2016-01-01

Problems involving mesh motion-which should not be mistakenly associated with moving mesh methods, a class of adaptive mesh redistribution techniques-are of critical importance in numerical simulations of the thermal response of melting and ablative materials. Ablation is the process by which material vaporizes or otherwise erodes due to strong heating. Accurate modeling of such materials is of the utmost importance in design of passive thermal protection systems ("heatshields") for spacecraft, the layer of the vehicle that ensures survival of crew and craft during re-entry. In an explicit mesh motion approach, a complete thermal solve is first performed. Afterwards, the thermal response is used to determine surface recession rates. These values are then used to generate boundary conditions for an a posteriori correction designed to update the location of the mesh nodes. Most often, linear elastic or biharmonic equations are used to model this material response, traditionally in a finite element framework so that complex geometries can be simulated. A simple scheme for moving the boundary nodes involves receding along the surface normals. However, for all but the simplest problem geometries, evolution in time following such a scheme will eventually bring the mesh to intersect and "tangle" with itself, inducing failure. This presentation demonstrates a comprehensive and sophisticated scheme that analyzes the local geometry of each node with help from user-provided clues to eliminate the tangle and enable simulations on a wide-class of difficult problem geometries. The method developed is demonstrated for linear elastic equations but is general enough that it may be adapted to other modeling equations. The presentation will explicate the inner workings of the tangle-free mesh motion algorithm for both two and three-dimensional meshes. It will show abstract examples of the method's success, including a verification problem that demonstrates its accuracy and correctness. The focus of the presentation will be on the algorithm; specifics on how the techniques may be used in spacecraft design will be not discussed.

At-vessel mortality of skates (Rajidae) taken in coastal fisheries and evidence of longer-term survival.

PubMed

Ellis, J R; Burt, G J; Grilli, G; McCully Phillips, S R; Catchpole, T L; Maxwell, D L

2018-06-01

Data on the vigour and at-vessel mortality (AVM) of 6798 skates (comprising Raja clavata n = 6295; R. brachyura n = 208; R. undulata n = 185, R. montagui n = 98 and R. microocellata n = 12) captured by commercial fishing vessels in the inshore waters of the southern North Sea and English Channel were recorded. AVM in longline fisheries averaged 0·44% across five vessels (0-1·47%), although skates were usually unhooked manually and did not usually pass through a bait-stripper. AVM in otter trawls averaged 0·76% (0-2·35%), from four vessels fishing with tow durations of <1·5 h (southern North Sea) or 1-4 h (English Channel). No AVM was noted for skates taken as a by-catch in drift trammel nets (soak times <4 h). Anchored tangle nets resulted in an overall AVM of 2·0-2·7%, but increased from 1·47% (13-28 h soak time) to 6·16% (42-53 h soak time). There were significant differences in the vigour of skates between gears, with R. clavata caught by longline and tangle nets in better condition than those captured by otter trawl or drift trammel net. Similarly, R. undulata caught by tangle net were in better condition than those caught by otter trawl. The vigour of R. undulata was also found to be higher than other skate species for both trawl and tangle net. In total, 5283 skates were tagged with Petersen discs and released, with recapture rates for the various combinations of vessel and gear ranging up to 24·8% for R. clavata. Whilst confirming a degree of post-release survival, quantitative estimates of post-release mortality for skates remain unknown. © 2018 Crown Copyright. Journal of Fish Biology © 2018 The Fisheries Society of the British Isles.

[F-18]-AV-1451 binding correlates with postmortem neurofibrillary tangle Braak staging.

PubMed

Marquié, Marta; Siao Tick Chong, Michael; Antón-Fernández, Alejandro; Verwer, Eline E; Sáez-Calveras, Nil; Meltzer, Avery C; Ramanan, Prianca; Amaral, Ana C; Gonzalez, Jose; Normandin, Marc D; Frosch, Matthew P; Gómez-Isla, Teresa

2017-10-01

[F-18]-AV-1451, a PET tracer specifically developed to detect brain neurofibrillary tau pathology, has the potential to facilitate accurate diagnosis of Alzheimer's disease (AD), staging of brain tau burden and monitoring disease progression. Recent PET studies show that patients with mild cognitive impairment and AD dementia exhibit significantly higher in vivo [F-18]-AV-1451 retention than cognitively normal controls. Importantly, PET patterns of [F-18]-AV-1451 correlate well with disease severity and seem to match the predicted topographic Braak staging of neurofibrillary tangles (NFTs) in AD, although this awaits confirmation. We studied the correlation of autoradiographic binding patterns of [F-18]-AV-1451 and the stereotypical spatiotemporal pattern of progression of NFTs using legacy postmortem brain samples representing different Braak NFT stages (I-VI). We performed [F-18]-AV-1451 phosphor-screen autoradiography and quantitative tau measurements (stereologically based NFT counts and biochemical analysis of tau pathology) in three brain regions (entorhinal cortex, superior temporal sulcus and visual cortex) in a total of 22 cases: low Braak (I-II, n = 6), intermediate Braak (III-IV, n = 7) and high Braak (V-VI, n = 9). Strong and selective [F-18]-AV-1451 binding was detected in all tangle-containing regions matching precisely the observed pattern of PHF-tau immunostaining across the different Braak stages. As expected, no signal was detected in the white matter or other non-tangle containing regions. Quantification of [F-18]-AV-1451 binding was very significantly correlated with the number of NFTs present in each brain region and with the total tau and phospho-tau content as reported by Western blot and ELISA. [F-18]-AV-1451 is a promising biomarker for in vivo quantification of brain tau burden in AD. Neuroimaging-pathologic studies conducted on postmortem material from individuals imaged while alive are now needed to confirm these observations.

A sequence of cytoskeleton changes related to the formation of neurofibrillary tangles and neuropil threads.

PubMed

Braak, E; Braak, H; Mandelkow, E M

1994-01-01

Frontal sections of the temporal lobe including the transentorhinal/entorhinal region, amygdala, and/or hippocampus from human adult brains are studied for cytoskeleton changes using immunostaining with the antibodies AT8 and Alz-50 and selective silver impregnation methods for neurofibrillary changes of the Alzheimer type. For the purpose of correlation, the two methods are carried out one after the other on the same section. Layer pre-alpha in the transentorhinal/entorhinal region harbours nerve cells which are among the first nerve cells in the entire brain to show the development of neurofibrillary changes. This presents the opportunity for study of both early events in the destruction of the cytoskeleton in individual neurons, and to relate changes which occur in the neuronal processes in the absence of alterations in their immediate surroundings to those happening in the soma. Immunoreactions with the AT8 antibody in particular reveal a clear sequence of changes in the neuronal cytoskeleton. Group 1 neurons present initial cytoskeleton changes in that the soma, dendrites, and axon are completely marked by granular AT8 immunoreactive material. These neurons appear quite normal and turn out to be devoid of argyrophilic material when observed in silver-stained sections. Group 2 neurons show changes in the cellular processes. The terminal tuft of the apical dendrite is replaced by tortuous varicose fibres and coarse granules. The distal portions of the dendrites are curved and show appendages and thickened portions. Intensely homogeneously immunostained rod-like inclusions are encountered in these thickened portions and in the soma. A number of these rod-like inclusions are visible after silver staining, as well. Group 3 neurons display even more pronounced alterations of their distal--most dendritic portions. The intermediate dendritic parts lose immunoreactivity, but the soma is homogeneously immunostained. Silver staining reveals in most of the distal dendritic parts neuropil threads, and in the soma a classic neurofibrillary tangle. Group 4 structures are marked by accumulations of coarse AT8-immunoreactive granules. Silver staining provides evidence that the fibrillary material has become an extraneuronal, "early" ghost tangle. Finally, group 5 structures present "late" ghost tangles in silver-stained sections but fail to demonstrate AT8 immunoreactivity. It is suggested that the altered tau protein shown by the antibody AT8 represents an early cytoskeleton change which eventually leads to the formation of argyrophilic neurofibrillary tangles and neuropil threads.

ApoE and Sex Bias in Cerebrovascular Aging of Men and Mice

PubMed Central

Finch, Caleb E.; Shams, Sara

2016-01-01

Alzheimer disease (AD) research has mainly focused on neurodegenerative processes associated with the classic neuropathologic markers of senile plaques and neurofibrillary tangles. Additionally, cerebrovascular contributions to dementia are increasingly recognized, particularly from cerebral small vessel disease (SVD). Remarkably, in AD brains, the ApoE ε4 allele shows male excess for cerebral microbleeds (CMB), a marker of SVD, which is opposite to the female excess of plaques and tangles. Mouse transgenic models add further complexities to sex-ApoE ε4 allele interactions, with female excess of CMBs and brain amyloid. We conclude that brain aging and AD pathogenesis cannot be understood in humans without addressing major gaps in the extent of sex differences in cerebrovascular pathology. PMID:27546867

Distribution of lead in the brain tissues from DNTC patients using synchrotron radiation microbeams

NASA Astrophysics Data System (ADS)

Ide-Ektessabi, Ari; Ota, Yukihide; Ishihara, Ryoko; Mizuno, Yutaka; Takeuchi, Tohru

2005-12-01

Diffuse neurofibrillary tangles with calcification (DNTC) is a form of dementia with certain characteristics. Its pathology is characterized by cerebrum atrophy, calcification on globus pallidus and dentate nucleus and diffuse neurofibrillary tangles without senile plaques. In the present study brain tissues were prepared from patients with patients DNTC, calcified and non-calcified Alzheimer's disease (AD) patients. The brain tissues were examined non-destructively by X-ray fluorescence (XRF) spectroscopy using synchrotron radiation (SR) microbeams for trace metallic elements Ca, Fe, Cu, Zn and Pb. The XRF analysis showed that there were Pb concentrations in the calcified areas in the brain tissues with both DNTC and AD but there was none in those with non-calcified AD.

Phylogenetic tree and community structure from a Tangled Nature model.

PubMed

Canko, Osman; Taşkın, Ferhat; Argın, Kamil

2015-10-07

In evolutionary biology, the taxonomy and origination of species are widely studied subjects. An estimation of the evolutionary tree can be done via available DNA sequence data. The calculation of the tree is made by well-known and frequently used methods such as maximum likelihood and neighbor-joining. In order to examine the results of these methods, an evolutionary tree is pursued computationally by a mathematical model, called Tangled Nature. A relatively small genome space is investigated due to computational burden and it is found that the actual and predicted trees are in reasonably good agreement in terms of shape. Moreover, the speciation and the resulting community structure of the food-web are investigated by modularity. Copyright © 2015 Elsevier Ltd. All rights reserved.

Time-dependent extinction rate and species abundance in a tangled-nature model of biological evolution.

PubMed

Hall, Matt; Christensen, Kim; di Collobiano, Simone A; Jensen, Henrik Jeldtoft

2002-07-01

We present a model of evolutionary ecology consisting of a web of interacting individuals, a tangle-nature model. The reproduction rate of individuals characterized by their genome depends on the composition of the population in genotype space. Ecological features such as the taxonomy and the macroevolutionary mode of the dynamics are emergent properties. The macrodynamics exhibit intermittent two-mode switching with a gradually decreasing extinction rate. The generated ecologies become gradually better adapted as well as more complex in a collective sense. The form of the species abundance curve compares well with observed functional forms. The model's error threshold can be understood in terms of the characteristics of the two dynamical modes of the system.

Negativity and strong monogamy of multiparty quantum entanglement beyond qubits

NASA Astrophysics Data System (ADS)

Choi, Jin Hyuk; Kim, Jeong San

2015-10-01

We propose the square of convex-roof extended negativity (SCREN) as a powerful candidate to characterize strong monogamy of multiparty quantum entanglement. We first provide a strong monogamy inequality of multiparty entanglement using SCREN and show that the tangle-based multiqubit strong-monogamy inequality can be rephrased by SCREN. We further show that the SCREN strong-monogamy inequality is still true for the counterexamples that violate tangle-based the strong-monogamy inequality in higher-dimensional quantum systems other than qubits. We also analytically show that SCREN strong-monogamy inequality is true for a large class of multiqudit states, a superposition of multiqudit generalized W -class states and vacuums. Thus SCREN is a good alternative to characterize the strong monogamy of entanglement even in multiqudit systems.

Responsible men, blameworthy women: Black heterosexual men's discursive constructions of safer sex and masculinity.

PubMed

Bowleg, Lisa; Heckert, Andrea L; Brown, Tia L; Massie, Jenné S

2015-04-01

Although Black heterosexual men (BHM) in the United States rank among those most affected by HIV, research about how safer sex messages shape their safer sex behaviors is rare, highlighting the need for innovative qualitative methodologies such as critical discursive psychology (CDP). This CDP study examined how: (a) BHM construct safer sex and masculinity; (b) BHM positioned themselves in relation to conventional masculinity; and (c) discursive context (individual interview vs. focus group) shaped talk about safer sex and masculinity. Data included individual interviews (n = 30) and 4 focus groups (n = 26) conducted with 56 self-identified Black/African American heterosexual men, ages 18 to 44. Analyses highlighted 5 main constructions: (a) condoms as signifiers of "safe" women; (b) blaming women for STI/responsibility for safer sex; (c) relationship/trust/knowledge; (d) condom mandates; and (e) public health safer sex. Discourses positioned BHM in terms of conventional masculinity when talk denied men's agency for safer sex and/or contraception, or positioned women as deceitful, or apathetic about sexual risk and/or pregnancy. Notably, discourses also spotlighted alternative masculinities relevant to taking responsibility for safer sex or sexual exclusivity. Discursive context, namely the homosocial nature of focus group discussions, shaped how participants conversed about safer sex, and masculinity but not the content of that talk. In denying BHM's responsibility for safer sex, BHM's discourses about safer sex and masculinity often mirror public health messages, underscoring a critical need to sync these discourses to reduce sexual risk, and develop gender-transformative safer sex interventions for BHM. (c) 2015 APA, all rights reserved).

The discursive production of professionals about humanizing health: singularity, rights and ethics1

PubMed Central

Silva, Rose Mary Costa Rosa Andrade; de Oliveira, Denize Cristina; Pereira, Eliane Ramos

2015-01-01

Objective: to describe the discursive production of professionals about the humanization of health. Method: qualitative study of descriptive approach, inspired by the social representation theory, with 24 professionals in the healthcare field, working in a university hospital with the established humanization policy. The selection of participants was conducted according to criteria of adequacy and diversity for an intentional sample. Data collection was conducted by semi-structured interviews. Results: through content analysis, three categories emerged, around which the analyses were conducted: "humanizing health as an act of accepting the other as unique", "humanizing health as a matter of right" and "humanizing health as an ethical issue". The discursive production of professionals is based on a perspective which is based on the humanist prospect with socio-historical bias. Conclusion: healthcare professionals must know the National Humanization Policy in order to provide quality care, promoting the meeting, welcoming and recognition of oneself, others and their profession in the political and socio-historical scenario of their country as a citizen, not only of rights, but also of obligations. PMID:26487145

Examination of the Clinicopathologic Continuum of Alzheimer Disease in the Autopsy Cohort of the National Alzheimer Coordinating Center

PubMed Central

Serrano-Pozo, Alberto; Qian, Jing; Monsell, Sarah E.; Frosch, Matthew P.; Betensky, Rebecca A.; Hyman, Bradley T.

2014-01-01

To test the hypothesis that Alzheimer disease (AD) is a clinical and pathologic continuum between normal aging and end-stage dementia, we selected a convenience sample of subjects from the National Alzheimer Coordinating Center 2005 to 2012 autopsy cohort (n = 2,083) with the last clinical evaluation within 2 years before autopsy and no other primary neuropathologic diagnosis. Demographic and neuropathologic characteristics were correlated with the Clinical Dementia Rating–Sum of Boxes in the 835 subjects meeting these criteria. Both neuritic plaques and neurofibrillary tangles independently predicted Clinical Dementia Rating–Sum of Boxes. Severe small-vessel disease, severe amyloid angiopathy, and hippocampal sclerosis were also independently associated with the degree of cognitive impairment. By contrast, education was a strong independent protective factor against cognitive deficits. The cause of mild to moderate dementia remained uncertain in 14% of the patients. Inverse probability weighting suggests the generalizability of these results to nonautopsied cohorts. These data indicate that plaques and tangles independently contribute to cognitive impairment, that concurrent vascular disease strongly correlates with cognitive dysfunction even in a sample selected to represent the AD pathologic continuum, and that education further modifies clinical expression. Thus, multiple concomitant etiologies of brain damage and premorbid characteristics contribute to the uncertainty of AD clinicopathologic correlations based only on tangles and plaques. PMID:24226270

Association of Cancer History with Alzheimer's Disease Dementia and Neuropathology.

PubMed

Yarchoan, Mark; James, Bryan D; Shah, Raj C; Arvanitakis, Zoe; Wilson, Robert S; Schneider, Julie; Bennett, David A; Arnold, Steven E

2017-01-01

Cancer and Alzheimer's disease (AD) are common diseases of aging and share many risk factors. Surprisingly, however, epidemiologic data from several recent independent cohort studies suggest that there may be an inverse association between these diseases. To determine the relationship between history of cancer and odds of dementia proximate to death and neuropathological indices of AD. Using data from two separate clinical-pathologic cohort studies of aging and AD, the Religious Orders Study (ROS) and the Rush Memory and Aging Project (MAP), we compared odds of AD dementia proximate to death among participants with and without a history of cancer. We then examined the relation of history of cancer with measures of AD pathology at autopsy, i.e., paired helical filament tau (PHFtau) neurofibrillary tangles and amyloid-β load. Participants reporting a history of cancer had significantly lower odds of AD (OR 0.70 [0.55-0.89], p = 0.0040) proximate to death as compared to participants reporting no prior history of cancer. The results remained significant after adjusting for multiple risk factors including age, sex, race, education, and presence of an APOEɛ4 allele. At autopsy, participants with a history of cancer had significantly fewer PHFtau tangles (p < 0.001) than participants without a history of cancer, but similar levels of amyloid-β. Cancer survivors have reduced odds of developing AD and a lower burden of neurofibrillary tangle deposition.

Examination of the clinicopathologic continuum of Alzheimer disease in the autopsy cohort of the National Alzheimer Coordinating Center.

PubMed

Serrano-Pozo, Alberto; Qian, Jing; Monsell, Sarah E; Frosch, Matthew P; Betensky, Rebecca A; Hyman, Bradley T

2013-12-01

To test the hypothesis that Alzheimer disease (AD) is a clinical and pathologic continuum between normal aging and end-stage dementia, we selected a convenience sample of subjects from the National Alzheimer Coordinating Center 2005 to 2012 autopsy cohort (n = 2,083) with the last clinical evaluation within 2 years before autopsy and no other primary neuropathologic diagnosis. Demographic and neuropathologic characteristics were correlated with the Clinical Dementia Rating-Sum of Boxes in the 835 subjects meeting these criteria. Both neuritic plaques and neurofibrillary tangles independently predicted Clinical Dementia Rating-Sum of Boxes. Severe small-vessel disease, severe amyloid angiopathy, and hippocampal sclerosis were also independently associated with the degree of cognitive impairment. By contrast, education was a strong independent protective factor against cognitive deficits. The cause of mild to moderate dementia remained uncertain in 14% of the patients. Inverse probability weighting suggests the generalizability of these results to nonautopsied cohorts. These data indicate that plaques and tangles independently contribute to cognitive impairment, that concurrent vascular disease strongly correlates with cognitive dysfunction even in a sample selected to represent the AD pathologic continuum, and that education further modifies clinical expression. Thus, multiple concomitant etiologies of brain damage and premorbid characteristics contribute to the uncertainty of AD clinicopathologic correlations based only on tangles and plaques.

Altered expression levels of the protein phosphatase 2A ABalphaC enzyme are associated with Alzheimer disease pathology.

PubMed

Sontag, Estelle; Luangpirom, Ampa; Hladik, Christa; Mudrak, Ingrid; Ogris, Egon; Speciale, Samuel; White, Charles L

2004-04-01

The formation of amyloid-containing senile plaques and tau-rich neurofibrillary tangles are central events in Alzheimer disease (AD) pathogenesis. Significantly, ABalphaC, a major protein phosphatase 2A (PP2A) holoenzyme, specifically binds to and dephosphorylates tau. Deregulation of PP2A results in tau hyperphosphorylation in vivo. Here, we compared the expression levels and distribution of PP2A subunits in various brain regions from autopsy cases of AD and aged controls with or without histological evidence of age-related neurofibrillary degeneration. Immunoblotting analyses revealed that there was a significant reduction in the total amounts of ABalphaC in AD frontal and temporal cortices that matched the decrease in PP2A activity measured in the same brain homogenates. Immunohistochemical studies showed that neuronal ABalphaC expression levels were significantly and selectively decreased in AD-affected regions and in tangle-bearing neurons, but not in AD cerebellum and in non-AD dementias. Reduced neuronal ABalphaC immunoreactivity closely correlated with tangle load, but not plaque burden, suggesting that ABalphaC dysfunction contributes to AD tau pathology. Glial cells within senile plaques were also positive for ABalphaC. Increased glial PP2A immunoreactivity was observed in both AD and non-AD cases and may play a role in the brain's response to general inflammatory processes and amyloidogenesis.

Investigating Interventions in Alzheimer's Disease with Computer Simulation Models

PubMed Central

Proctor, Carole J.; Boche, Delphine; Gray, Douglas A.; Nicoll, James A. R.

2013-01-01

Progress in the development of therapeutic interventions to treat or slow the progression of Alzheimer's disease has been hampered by lack of efficacy and unforeseen side effects in human clinical trials. This setback highlights the need for new approaches for pre-clinical testing of possible interventions. Systems modelling is becoming increasingly recognised as a valuable tool for investigating molecular and cellular mechanisms involved in ageing and age-related diseases. However, there is still a lack of awareness of modelling approaches in many areas of biomedical research. We previously developed a stochastic computer model to examine some of the key pathways involved in the aggregation of amyloid-beta (Aβ) and the micro-tubular binding protein tau. Here we show how we extended this model to include the main processes involved in passive and active immunisation against Aβ and then demonstrate the effects of this intervention on soluble Aβ, plaques, phosphorylated tau and tangles. The model predicts that immunisation leads to clearance of plaques but only results in small reductions in levels of soluble Aβ, phosphorylated tau and tangles. The behaviour of this model is supported by neuropathological observations in Alzheimer patients immunised against Aβ. Since, soluble Aβ, phosphorylated tau and tangles more closely correlate with cognitive decline than plaques, our model suggests that immunotherapy against Aβ may not be effective unless it is performed very early in the disease process or combined with other therapies. PMID:24098635

Towards Legitimate Nursing Work? Historical Discursive Constructions of Abortion in The Canadian Nurse, 1950-1965.

PubMed

Haney, Catherine

2014-01-01

To the detriment of women's health, the abortion work of nurses in Canada has gone largely unexamined and is not well understood. This historical discourse analysis examines discursive constructions of nurses' abortion work and ongoing renegotiations of professional identity in The Canadian Nurse from 1950 to 1965. By investigating what has shaped and continues to inform nurses' understandings and enactment of abortion work over time, I hope to contribute to a foundation from which to evaluate contemporary abortion services and to foster conditions that support nurses in providing safe abortion care.

Extracellular neurofibrillary tangles associated with degenerating neurites and neuropil threads in Alzheimer-type dementia.

PubMed

Yamaguchi, H; Nakazato, Y; Kawarabayashi, T; Ishiguro, K; Ihara, Y; Morimatsu, M; Hirai, S

1991-01-01

We examined the cellular components of extracellular neurofibrillary tangles (E-NFT) in the hippocampal areas in cases with Alzheimer-type dementia. Immunohistochemically, the E-NFT were labeled for the C terminus of tau and glial fibrillary acidic protein. Moreover, the majority of the E-NFT was associated with intensely argyrophilic rods and with tau- and ubiquitin-immunoreactive dots. Ultrastructurally, the E-NFT consisted mainly of extracellular paired helical filaments (PHF) and astroglial processes. The extracellular PHF tended to be straighter and thinner. One third of the E-NFT was associated with small degenerating neurites containing many dense bodies and with neuropil threads containing PHF. These findings suggested that extracellular PHF promote both intense astroglial reaction and neuritic alteration, and that the E-NFT are continuously changing their morphology.

Computational Study of Pseudo-phosphorylation of the Microtubule associated Protein Tau

NASA Astrophysics Data System (ADS)

Prokopovich, Dmitriy; Larini, Luca

This computational study focuses on the effect of pseudo-phosphorylation on the aggregation of the microtubule associated protein tau. In the axon of the neuron, tau regulates the assembly of microtubules in the cytoskeleton. This is important for both stabilization of and transport across the microtubules. One of the hallmarks of the Alzheimer's disease is that tau is hyper-phosphorylated and aggregates into neurofibrillary tangles that lay waste to the neurons. It is not known if hyper-phosphorylation directly causes the aggregation of tau into tangles. Experimentally, pseudo-phosphorylation mimics the effects of phosphorylation by mutating certain residues of the protein chain into charged residues. In this study, we will consider the fragment called PHF43 that belongs to the microtubule binding region and has been shown to readily aggregate.

Experimental verification of a new Bell-type inequality

NASA Astrophysics Data System (ADS)

Zhao, Jia-Qiang; Cao, Lian-Zhen; Yang, Yang; Li, Ying-De; Lu, Huai-Xin

2018-05-01

Arpan Das et al. proposed a set of new Bell inequalities (Das et al., 2017 [16]) for a three-qubit system and claimed that each inequality within this set is violated by all generalized Greenberger-Horne-Zeilinger (GGHZ) states. We investigate experimentally the new inequalities in the three-photon GGHZ class states. Since the inequalities are symmetric under the identical particles system, we chose one Bell-type inequality from the set arbitrarily. The experimental data well verified the theoretical prediction. Moreover, the experimental results show that the amount of violation of the new Bell inequality against locality realism increases monotonically following the increase of the tangle of the GGHZ state. The most profound physical essence revealed by the results is that the nonlocality of GGHZ state correlate with three tangles directly.

Apolipoprotein E and Sex Bias in Cerebrovascular Aging of Men and Mice.

PubMed

Finch, Caleb E; Shams, Sara

2016-09-01

Alzheimer disease (AD) research has mainly focused on neurodegenerative processes associated with the classic neuropathologic markers of senile plaques and neurofibrillary tangles. Additionally, cerebrovascular contributions to dementia are increasingly recognized, particularly from cerebral small vessel disease (SVD). Remarkably, in AD brains, the apolipoprotein E (ApoE) ɛ4 allele shows male excess for cerebral microbleeds (CMBs), a marker of SVD, which is opposite to the female excess of plaques and tangles. Mouse transgenic models add further complexities to sex-ApoE ɛ4 allele interactions, with female excess of both CMBs and brain amyloid. We conclude that brain aging and AD pathogenesis cannot be understood in humans without addressing major gaps in the extent of sex differences in cerebrovascular pathology. Copyright © 2016 Elsevier Ltd. All rights reserved.

γ-Aminobutyric Acid (GABA) Production and Angiotensin-I Converting Enzyme (ACE) Inhibitory Activity of Fermented Soybean Containing Sea Tangle by the Co-Culture of Lactobacillus brevis with Aspergillus oryzae.

PubMed

Jang, Eun Kyeong; Kim, Nam Yeun; Ahn, Hyung Jin; Ji, Geun Eog

2015-08-01

To enhance the γ-aminobutyric acid (GABA) content, the optimized fermentation of soybean with added sea tangle extract was evaluated at 30°C and pH 5.0. The medium was first inoculated with Aspergillus oryzae strain FMB S46471 and fermented for 3 days, followed by the subsequent inoculation with Lactobacillus brevis GABA 100. After fermentation for 7 days, the fermented soybean showed approximately 1.9 g/kg GABA and exhibited higher ACE inhibitory activity than the traditional soybean product. Furthermore, several peptides in the fraction containing the highest ACE inhibitory activity were identified. The novel fermented soybean enriched with GABA and ACE inhibitory components has great pharmaceutical and functional food values.

Forecasting transitions in systems with high-dimensional stochastic complex dynamics: a linear stability analysis of the tangled nature model.

PubMed

Cairoli, Andrea; Piovani, Duccio; Jensen, Henrik Jeldtoft

2014-12-31

We propose a new procedure to monitor and forecast the onset of transitions in high-dimensional complex systems. We describe our procedure by an application to the tangled nature model of evolutionary ecology. The quasistable configurations of the full stochastic dynamics are taken as input for a stability analysis by means of the deterministic mean-field equations. Numerical analysis of the high-dimensional stability matrix allows us to identify unstable directions associated with eigenvalues with a positive real part. The overlap of the instantaneous configuration vector of the full stochastic system with the eigenvectors of the unstable directions of the deterministic mean-field approximation is found to be a good early warning of the transitions occurring intermittently.

Pathological conformations involving the amino terminus of tau occur early in Alzheimer’s disease and are differentially detected by monoclonal antibodies

PubMed Central

Combs, Benjamin; Hamel, Chelsey; Kanaan, Nicholas M.

2016-01-01

Conformational changes involving the amino terminus of the tau protein are among the earliest alterations associated with tau pathology in Alzheimer’s disease and other tauopathies. This region of tau contains a phosphatase-activating domain (PAD) that is aberrantly exposed in pathological forms of the protein, an event that is associated with disruptions in anterograde fast axonal transport. We utilized four antibodies that recognize the amino terminus of tau, TNT1, TNT2 (a novel antibody), Tau12, and Tau13, to further study this important region. Using scanning alanine mutations in recombinant tau proteins, we refined the epitopes of each antibody. We examined the antibodies’ relative abilities to specifically label pathological tau in non-denaturing and denaturing assays to gain insight into some of the mechanistic details of PAD exposure. We then determined the pattern of tau pathology labeled by each antibody in human hippocampal sections at various disease stages in order to characterize PAD exposure in the context of disease progression. The characteristics of reactivity for the antibodies fell into two groups. TNT1 and TNT2 recognized epitopes within amino acids 7–12 and specifically identified recombinant tau aggregates and pathological tau from Alzheimer’s disease brains in a conformation-dependent manner. These antibodies labeled early pre-tangle pathology from neurons in early Braak stages and colocalized with thiazine red, a marker of fibrillar pathology, in classic neurofibrillary tangles. However, late tangles were negative for TNT1 and TNT2 indicating a loss of the epitope in later stages of tangle evolution. In contrast, Tau12 and Tau13 both identified discontinuous epitopes in the amino terminus and were unable to differentiate between normal and pathological tau in biochemical and tissue immunohistological assays. Despite the close proximity of these epitopes, the antibodies demonstrated remarkably different abilities to identify pathological changes in tau indicating that detection of conformational alterations involving PAD exposure is not achieved by all N-terminal tau antibodies and that a relatively discrete region of the N-terminus (i.e., amino acids 7–12, the TNT1 and TNT2 epitope) is central to the differences between normal and pathological tau. The appearance of PAD in early tau pathology and its disappearance in late-stage tangles suggest that toxic forms of tau are associated with the earliest forms of tau deposits. Collectively, these findings demonstrate that the TNT antibodies are useful markers for early conformational display of PAD and provide information regarding conformational changes that have potential implications in the toxic mechanisms of tau pathology. PMID:27260838

Sensitizing events as trigger for discursive renewal and institutional change in Flanders’ environmental health approach, 1970s-1990s

PubMed Central

2013-01-01

Background Sensitizing events may trigger and stimulate discursive renewal. From a discursive institutional perspective, changing discourses are the driving force behind the institutional dynamics of policy domains. Theoretically informed by discursive institutionalism, this article assesses the impact of a series of four sensitizing events that triggered serious environmental health concerns in Flanders between the 1970s till the 1990s, and led onto the gradual institutionalization of a Flemish environmental health arrangement. Methods The Policy Arrangement Approach is used as the analytical framework to structure the empirical results of the historical analysis based on document analysis and in-depth interviews. Results Until the 1990s, environmental health was characterized as an ad hoc policy field in Flanders, where agenda setting was based on sensitizing events – also referred to as incident-driven. Each of these events contributed to a gradual rethinking of the epistemological discourses about environmental health risks and uncertainties. These new discourses were the driving forces behind institutional dynamics as they gradually resulted in an increased need for: 1) long-term, policy-oriented, interdisciplinary environmental health research; 2) policy coordination and integration between the environmental and public health policy fields; and 3) new forms of science-policy interactions based on mutual learning. These changes are desirable in order to detect environmental health problems as fast as possible, to react immediately and communicate appropriately. Conclusions The series of four events that triggered serious environmental health concerns in Flanders provided the opportunity to rethink and re-organize the current affairs concerning environmental health and gradually resulted into the institutionalization of a Flemish environmental health arrangement. PMID:23758822

Handling the Dilemma of Self-Determination and Dementia: A Study of Case Managers' Discursive Strategies in Assessment Meetings.

PubMed

Österholm, Johannes H; Taghizadeh Larsson, Annika; Olaison, Anna

2015-01-01

In assessment meetings concerning care services for people with dementia, Swedish case managers face a dilemma. On the one hand, according to the law, the right to self-determination of every adult citizen must be respected, but on the other hand cognitive disabilities make it difficult to fulfill obligations of being a full-fledged citizen. In this article, we examine 15 assessment meetings to identify discursive strategies used by case managers to handle this dilemma. We also examine how these affect the participation of persons with dementia, and indicate implications of our study for social work practice and research.

Sarah was a butch: sexual identity, gender practices, and Sarah's place as mother in the Jewish National Pantheon.

PubMed

Kalev, Henriette Dahan

2012-01-01

Three fields of discourse regarding a masculine-like woman connect at a point that the queer field calls intersex, medical practice calls a sexual disorder, and rabbinic literature terms aylonit. The queer discursive field focuses on the freedom to choose an identity, but not the freedom from choosing one. The medical field focuses on sexual practice as the source of determining "normal" sexuality. In the discursive field of Jewish law there are no demands, because the Halakhic authority determines gender identity on behalf of the individual, maintaining ambiguity. Copyright © Taylor & Francis Group, LLC

Queer blindfolding: a case study on difference "blindness" toward persons who identify as lesbian, gay, bisexual, and transgender.

PubMed

Smith, Lance C; Shin, Richard Q

2014-01-01

The purpose of this article is to introduce and explore the narrative strategy of queer blindfolding. Utilizing psycho-discursive qualitative methodology, the authors will draw from a case study to demonstrate how some beneficent, well-intended persons who identify as heterosexual adopt the narrative strategy of queer blindfolding as they negotiate the discourse of heteronormativity. We will map this narrative strategy, compare and contrast it to racial colorblindness, and unpack the accompanying intra-psychic conflict and defense mechanisms that are utilized by the participant in the case study. We will also demonstrate how this discursive strategy positions participants within systemic heterosexism.

How Ending Impunity for Conflict-Related Sexual Violence Overwhelmed the UN Women, Peace, and Security Agenda: A Discursive Genealogy.

PubMed

Reilly, Niamh

2018-05-01

The recent unprecedented focus on ending impunity for conflict-related sexual violence (CRSV) is positive in many respects. However, it has narrowed the scope of Security Council Resolution 1325 and the women, peace, and security (WPS) agenda it established in 2000. Through a critical discursive genealogy of the interrelation of two UN agendas-protection of civilians in armed conflict and women, peace, and security-the author traces how CRSV emerged as the defining issue of the latter while the transformative imperative of making women's participation central to every UN endeavor for peace and security has failed to gain traction.

"You" and "I," "us " and them: a systemic-discursive approach to the study of ethnic stereotypes in the context of British-Greek heterosexual couple relationships.

PubMed

Tseliou, Eleftheria; Eisler, Ivan

2007-12-01

Systemic family therapy accounts of ethnic stereotypes in the context of ethnically mixed couple relationships have tended to focus on the interpersonal-psychological realm of the couple relationship. Discourse analytic research, on the other hand, has highlighted the role of such stereotypes in the construction of national identity and has stressed the importance of a historical and ideological approach. In this article, we will present our attempt to develop a systemic-discursive approach to the study of stereotypes in the particular context of British-Greek heterosexual couple relationships by building on both fields.

Amoral, im/moral and dis/loyal: Children's moral status in child welfare.

PubMed

Knezevic, Zlatana

2017-11-01

This article is a discursive examination of children's status as knowledgeable moral agents within the Swedish child welfare system and in the widely used assessment framework BBIC. Departing from Fricker's concept of epistemic injustice, three discursive positions of children's moral status are identified: amoral, im/moral and dis/loyal. The findings show the undoubtedly moral child as largely missing and children's agency as diminished, deviant or rendered ambiguous. Epistemic injustice applies particularly to disadvantaged children with difficult experiences who run the risk of being othered, or positioned as reproducing or accommodating to the very same social problems they may be victimised by.

Supporting pre-service elementary teachers in their understanding of inquiry teaching through the construction of a third discursive space

NASA Astrophysics Data System (ADS)

Greca, Ileana M.

2016-03-01

Several international reports promote the use of the inquiry teaching methodology for improvements in science education at elementary school. Nevertheless, research indicates that pre-service elementary teachers have insufficient experience with this methodology and when they try to implement it, the theory they learnt in their university education clashes with the classroom practice they observe, a problem that has also been noted with other innovative methodologies. So, it appears essential for pre-service teachers to conduct supportive reflective practice during their education to integrate theory and practice, which various studies suggest is not usually done. Our study shows how opening up a third discursive space can assist this supportive reflective practice. The third discursive space appears when pre-service teachers are involved in specific activities that allow them to contrast the discourses of theoretical knowledge taught at university with practical knowledge arising from their ideas on science and science teaching and their observations during classroom practice. The case study of three pre-service teachers shows that this strategy was fundamental in helping them to integrate theory and practice, resulting in a better understanding of the inquiry methodology and its application in the classroom.

Untroubling abortion: A discourse analysis of women’s accounts

PubMed Central

2017-01-01

In this paper, I highlight key differences between a discourse analytic approach to women’s accounts of abortion and that taken by the growing body of research that seeks to explore and measure women’s experiences of abortion stigma. Drawing on critical analyses of the conceptualisation of stigma in other fields of healthcare, I suggest that research on abortion stigma often risks reifying it by failing to consider how identities are continually re-negotiated through language-use. In contrast, by attending to language as a form of social action, discursive psychology makes it possible to emphasise speakers’ capacity to construct “untroubled” (i.e. non-stigmatised) identities, while acknowledging that this process is constrained by the contexts in which talk takes place. My analysis applies these insights to interviews with women concerning their experiences of having an abortion in England. I highlight three forms of discursive work through which women navigate “trouble” in their accounts of abortion, and critically consider the resources available for meaning-making within this particular context of talk. In doing so, I aim to provoke reflection about the discursive frameworks through which women’s accounts of abortion are solicited and explored. PMID:28546656

A reconsideration of the gendered mechanisms of support in online interactions about testicular implants: a discursive approach.

PubMed

Seymour-Smith, Sarah

2013-01-01

Researchers have observed gender differences in the frequency of emotion language used in cancer forums, with men more likely to seek medical information and women more likely to seek social and emotional support (Blank, Schmidt, Vangsness, Monteiro, & Santagata, 2010; Seale, Ziebland, & Charteris-Black, 2006). The aim of this article was to investigate Internet support groups to examine the support mechanisms that men employed when deciding whether or not to have a testicular implant. The four longest threads about prostheses were taken from four separate testicular cancer online support forums (totaling a number of 129 posts). A discursive approach (Edwards & Potter, 2001) was employed in order to consider what support mechanisms were employed by men. Findings illustrate that men employed a number of discursive strategies in "doing" support, including assessments, attending to issues of accountability, humor, providing alternative information, constructing decisions as personal choices, reconstituting normality, and sanctioning "emotional" talk. The psychological benefits of online homosocial support are discussed, and it is suggested that clinicians recommend Internet support groups to men with testicular cancer in order to start the psychological healing process. PsycINFO Database Record (c) 2013 APA, all rights reserved.

Caring to death: the murder of patients by nurses.

PubMed

Field, John; Pearson, Alan

2010-06-01

Beyond the initial 'shock-horror' reaction in the mass media, little attention is paid by nurses or the public to nurses who murder patients. This study used discursive inquiry to uncover social constructions of this phenomenon and their implications for the definition and treatment of such murders. The mass media and professional literature were searched for commentary on cases of nurses who had been convicted of murder between 1980 and 2006. The retrieved texts were subjected to discursive analysis. Discursive constructions included the profile of murderous nurses; types of murders; contexts in which murder occurs; factors that aid detection and apprehension; legal processes and punishment; and reactions of the public, profession, regulators and families. The findings imply that murder of a patient by a nurse might occur in any setting in which nurses care for vulnerable patients--the old, the young, the sick and the disabled. Trust in nurses assists a nurse to murder. Nurses have a responsibility to understand how their workplaces can form crucibles in which murder can take place. The profession needs to acknowledge the possibility of nurses who murder patients and to commence a discussion about what might be done to limit the harm they do.

Analyzing psychotherapy process as intersubjective sensemaking: an approach based on discourse analysis and neural networks.

PubMed

Nitti, Mariangela; Ciavolino, Enrico; Salvatore, Sergio; Gennaro, Alessandro

2010-09-01

The authors propose a method for analyzing the psychotherapy process: discourse flow analysis (DFA). DFA is a technique representing the verbal interaction between therapist and patient as a discourse network, aimed at measuring the therapist-patient discourse ability to generate new meanings through time. DFA assumes that the main function of psychotherapy is to produce semiotic novelty. DFA is applied to the verbatim transcript of the psychotherapy. It defines the main meanings active within the therapeutic discourse by means of the combined use of text analysis and statistical techniques. Subsequently, it represents the dynamic interconnections among these meanings in terms of a "discursive network." The dynamic and structural indexes of the discursive network have been shown to provide a valid representation of the patient-therapist communicative flow as well as an estimation of its clinical quality. Finally, a neural network is designed specifically to identify patterns of functioning of the discursive network and to verify the clinical validity of these patterns in terms of their association with specific phases of the psychotherapy process. An application of the DFA to a case of psychotherapy is provided to illustrate the method and the kinds of results it produces.

Genuine four tangle for four qubit states

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sharma, S. Shelly; Sharma, N. K.

We report a four qubit polynomial invariant that quantifies genuine four-body correlations. The four qubit invariants are obtained from transformation properties of three qubit invariants under a local unitary on the fourth qubit.

2-Styrylindolium based fluorescent probes visualize neurofibrillary tangles in Alzheimer's disease.

PubMed

Gu, Jiamin; Anumala, Upendra Rao; Lo Monte, Fabio; Kramer, Thomas; Heyny von Haußen, Roland; Hölzer, Jana; Goetschy-Meyer, Valérie; Mall, Gerhard; Hilger, Ingrid; Czech, Christian; Schmidt, Boris

2012-12-15

We evaluated 2-styrylindolium derivatives (6-11) as novel and selective probes for neurofibrillary tangles (NFTs) on brain sections of AD patients. The staining experiments indicated that these compounds may bind selectively to NFTs in the presence of ß-amyloid (Aß) plaques. Cell free binding assays confirmed that 2-[2-[4-(1-pyrrolidinyl)phenyl]ethenyl]-1,3,3-trimethyl-3H-indolium iodide (9) and 2-[2-[4-(diethylamino)phenyl]ethenyl]-1-butyl-3,3-dimethyl-3H-indolium iodide (11) display excellent affinities to Tau-aggregates (IC(50) values of 5.1 and 1.4 nM, respectively) in the displacement of Thiazin Red R. These probes have good solubility in distilled water and low or no cytotoxicity in zebrafish embryo and liver hepatocellular carcinoma cell assays. Copyright © 2012 Elsevier Ltd. All rights reserved.

Nanoflare Heating of Solar and Stellar Coronae

NASA Technical Reports Server (NTRS)

Klimchuk, James A.

2010-01-01

A combination of observational and theoretical evidence suggests that much, and perhaps most, of the Sun's corona is heated by small unresolved bursts of energy called nanoflares. It seems likely that stellar coronae are heated in a similar fashion. Kanoflares are here taken to mean any impulsive heating that occurs within a magnetic flux strand. Many mechanisms have this property, including waves, but we prefer Parker's picture of tangled magnetic fields. The tangling is caused by turbulent convection at the stellar surface, and magnetic energy is released when the stresses reach a critical level. We suggest that the mechanism of energy release is the "secondary instability" of electric current sheets that are present at the boundaries between misaligned strands. I will discuss the collective evidence for solar and stellar nanoflares and hopefully present new results from the Solar Dynamics Observatory that was just launched.

Camelid single-domain antibodies: A versatile tool for in vivo imaging of extracellular and intracellular brain targets.

PubMed

Li, Tengfei; Vandesquille, Matthias; Koukouli, Fani; Dudeffant, Clémence; Youssef, Ihsen; Lenormand, Pascal; Ganneau, Christelle; Maskos, Uwe; Czech, Christian; Grueninger, Fiona; Duyckaerts, Charles; Dhenain, Marc; Bay, Sylvie; Delatour, Benoît; Lafaye, Pierre

2016-12-10

Detection of intracerebral targets with imaging probes is challenging due to the non-permissive nature of blood-brain barrier (BBB). The present work describes two novel single-domain antibodies (VHHs or nanobodies) that specifically recognize extracellular amyloid deposits and intracellular tau neurofibrillary tangles, the two core lesions of Alzheimer's disease (AD). Following intravenous administration in transgenic mouse models of AD, in vivo real-time two-photon microscopy showed gradual extravasation of the VHHs across the BBB, diffusion in the parenchyma and labeling of amyloid deposits and neurofibrillary tangles. Our results demonstrate that VHHs can be used as specific BBB-permeable probes for both extracellular and intracellular brain targets and suggest new avenues for therapeutic and diagnostic applications in neurology. Copyright © 2016 Elsevier B.V. All rights reserved.

Frequent coexistence of Lewy bodies and neurofibrillary tangles in the same neurons of patients with diffuse Lewy body disease.

PubMed

Iseki, E; Marui, W; Kosaka, K; Uéda, K

1999-04-09

We examined the frequency of neurons with coexistent Lewy bodies (LB) and neurofibrillary tangles (NFT) in diffuse Lewy body disease brains, by a double-immunostaining method using MDV2 and Human tau. Double-positive neurons were frequently observed in the limbic areas. These neurons mostly revealed the feature of intermingled MDV2- and Human tau-positive substances. Immunoelectron microscopically, the MDV2-positive components were not in continuity with the MDV2-negative paired helical filaments (PHF). The MDV2-positive LB were surrounded by the small PHF bundles, frequently accompanied by the randomly oriented PHF within LB. In the intermingled neurons, MDV2-positive non-filamentous components without LB were found among the large PHF bundles. These non-filamentous components may represent the early stage of LB formation.

Improvements in Alzheimer's disease diagnosis using principle components analysis (PCA) in combination with Raman spectroscopy

NASA Astrophysics Data System (ADS)

Archer, John K. J.; Sudworth, Caroline D.; Williams, Rachel; How, Thien; Stone, Nicholas; Mann, David; Black, Richard A.

2007-07-01

The significant achievements of medical science over the last century are evident in the increasing age of the global population, however this now brings new problems, the most prominent being the growth in the number of people suffering from dementia. Over half the people with dementia in the UK are sufferers of Alzheimer's disease, a condition in which intraneuronal neurofibrillary tangles and extraneuronal senile tangles take over neurons prompting their death. A definitive diagnosis is still only currently available post-mortem, whilst current symptom based processes of elimination are far from perfect, especially when the only treatments available are symptom inhibiting drugs. Principal component analysis (PCA) of the Raman spectra taken from brain tissue has proved to be a potential tool in the diagnosis. However, this work now has to be refined in order to progress to tissue less associated with the symptoms of Alzheimer's disease. The first step of this has already been taken in progressing from frontal tissue to occipital tissue point spectra taken at random positions from bulk tissue. Now we present initial work into acquiring Raman spectral maps from across a tissue area, in pursuit of identifying unique plaque and tangle spectra. These spectra are presented alongside synthetic β-Amyloid spectra, in a study of the role that the peptide plays in the biomarker spectra, and how this information can aid the PCA of bulk tissue, and point towards a Raman spectroscopic test on less sensitive tissue, such as blood.

Principal facts for 408 gravity stations in the vicinity of the Talkeetna Mountains, south-central Alaska

USGS Publications Warehouse

Morin, Robert L.; Glen, Jonathan M.G.

2003-01-01

Gravity data were collected between 1999 and 2002 along transects in the Talkeetna Mountains of south-central Alaska as part of a geological and geophysical study of the framework geology of the region. The study area lies between 61° 30’ and 63° 45’ N. latitude and 145° and 151° W. longitude. This data set includes 408 gravity stations. These data, combined with the pre-existing 3,286 stations, brings the total data in this area to 3,694 gravity stations. Principal facts for the 408 new gravity stations and the 15 gravity base stations used for control are listed in this report. During the summer of 1999, a gravity survey was conducted in the western Talkeetna Mountains. Measurements at 55 gravity stations were made. One gravity base station was used for control for this survey. This base station, STEP, is located at the Stephan Lake Lodge on Stephan Lake. The observed gravity of this station was calculated based on an indirect tie to base station ANCL in Anchorage. The temporary base used to tie between STEP and ANCL was REGL in Anchorage. During the summer of 2000, a gravity survey was conducted in the western Talkeetna Mountains. Measurements at 56 gravity stations were made. One gravity base station was used for control for this survey. This base station, GRHS, is located at the Gracious House Lodge on the Denali Highway. The observed gravity of this station was calculated based on multiple ties to base stations D87, and D57 along the Denali Highway. During the summer of 2001, a gravity survey was conducted in the western Talkeetna Mountains. Measurements at 90 gravity stations were made. One gravity base station was used for control for this survey. This base station, HLML, is located at the High Lake Lodge. The observed gravity of this station was calculated based on multiple ties to base stations ANCU in Anchorage, PALH in Palmer, WASA in Wasilla, and TLKM in Talkeetna. Also during the summer of 2001, a gravity survey was conducted in the vicinity of Tangle Lakes. Measurements at 86 gravity stations were made. The Tangle Lakes area is located about 25 km west of Paxson and north of the Denali Highway. One gravity base station was used for control for this survey. This base station, TLIN, is located at the Tangle Lakes Inn. The observed gravity of this station was calculated based on multiple ties to base stations ANCU in Anchorage, PALH in Palmer, BD27 in Gulkana, B-07 on the Richardson Highway, and base stations D42, and D57 along the Denali Highway. During the summer of 2002, measurements at an additional 107 gravity stations were made in the vicinity of Tangle Lakes. Base station TLIN at the Tangle Lakes Inn was again used for control. Additional ties to base stations ANCU and B-07 were made.

Lexical shifts, substantive changes, and continuity in State of the Union discourse, 1790–2014

PubMed Central

Rule, Alix; Cointet, Jean-Philippe; Bearman, Peter S.

2015-01-01

This study reveals that the entry into World War I in 1917 indexed the decisive transition to the modern period in American political consciousness, ushering in new objects of political discourse, a more rapid pace of change of those objects, and a fundamental reframing of the main tasks of governance. We develop a strategy for identifying meaningful categories in textual corpora that span long historic durées, where terms, concepts, and language use changes. Our approach is able to account for the fluidity of discursive categories over time, and to analyze their continuity by identifying the discursive stream as the object of interest. PMID:26261302

'Health should not have to be a problem': talking health and accountability in an internet forum on veganism.

PubMed

Sneijder, Petra; te Molder, Hedwig F M

2004-07-01

This article draws upon insights from discursive psychology to examine how participants in an Internet forum on veganism orient to the relationship between food choice, health and accountability. First, we explore the ways in which participants ascribe responsibility for health problems like vitamin deficiency to individual recipients. By suggesting individual practices as a cause for problems, speakers undermine the notion that problems arise through veganism as a matter of principle. Second, we show how participants construct solutions to individual health problems as involving mundane and simple actions. Both discursive procedures enable speakers to resist negative assumptions about the potentially complicated nature of veganism in relation to health protection.

Amoral, im/moral and dis/loyal: Children’s moral status in child welfare

PubMed Central

Knezevic, Zlatana

2017-01-01

This article is a discursive examination of children’s status as knowledgeable moral agents within the Swedish child welfare system and in the widely used assessment framework BBIC. Departing from Fricker’s concept of epistemic injustice, three discursive positions of children’s moral status are identified: amoral, im/moral and dis/loyal. The findings show the undoubtedly moral child as largely missing and children’s agency as diminished, deviant or rendered ambiguous. Epistemic injustice applies particularly to disadvantaged children with difficult experiences who run the risk of being othered, or positioned as reproducing or accommodating to the very same social problems they may be victimised by. PMID:29187776

The Computational Fluid Dynamics Rupture Challenge 2013—Phase I: prediction of rupture status in intracranial aneurysms.

PubMed

Janiga, G; Berg, P; Sugiyama, S; Kono, K; Steinman, D A

2015-03-01

Rupture risk assessment for intracranial aneurysms remains challenging, and risk factors, including wall shear stress, are discussed controversially. The primary purpose of the presented challenge was to determine how consistently aneurysm rupture status and rupture site could be identified on the basis of computational fluid dynamics. Two geometrically similar MCA aneurysms were selected, 1 ruptured, 1 unruptured. Participating computational fluid dynamics groups were blinded as to which case was ruptured. Participants were provided with digitally segmented lumen geometries and, for this phase of the challenge, were free to choose their own flow rates, blood rheologies, and so forth. Participants were asked to report which case had ruptured and the likely site of rupture. In parallel, lumen geometries were provided to a group of neurosurgeons for their predictions of rupture status and site. Of 26 participating computational fluid dynamics groups, 21 (81%) correctly identified the ruptured case. Although the known rupture site was associated with low and oscillatory wall shear stress, most groups identified other sites, some of which also experienced low and oscillatory shear. Of the 43 participating neurosurgeons, 39 (91%) identified the ruptured case. None correctly identified the rupture site. Geometric or hemodynamic considerations favor identification of rupture status; however, retrospective identification of the rupture site remains a challenge for both engineers and clinicians. A more precise understanding of the hemodynamic factors involved in aneurysm wall pathology is likely required for computational fluid dynamics to add value to current clinical decision-making regarding rupture risk. © 2015 by American Journal of Neuroradiology.

The Impact of Interpersonal Style on Ruptures and Repairs in the Therapeutic Alliance Between Offenders and Therapists in Sex Offender Treatment.

PubMed

Watson, Rachael; Thomas, Stuart; Daffern, Michael

2017-10-01

The therapeutic relationship is a critical component of psychological treatment. Strain can occur in the relationship, particularly when working with offenders, and more specifically, those offenders with interpersonal difficulties; strain can lead to a rupture, which may affect treatment participation and performance. This study examined ruptures in the therapeutic relationship in sexual offenders participating in offense-focused group treatment. Fifty-four sex offenders rated the therapeutic alliance at the commencement and completion of treatment; at the completion of treatment, they also reported on the occurrence of ruptures and whether they believed these ruptures were repaired. Ruptures were separated by type, according to severity-Each relationship was therefore characterized as experiencing no rupture, a minor rupture, or a major rupture. Offender characteristics including interpersonal style (IPS) and psychopathy were assessed at the commencement of treatment; their relationship with ruptures was examined. Results revealed that more than half of the offenders (approximately 55%) experienced a rupture in the therapeutic alliance, with one in four of these ruptures remaining unresolved. Offenders who did not report a rupture rated the therapeutic alliance significantly higher at the end of treatment compared with those offenders who reported a rupture that was not repaired. Offenders who reported a major rupture in the therapeutic relationship were higher in interpersonal hostility and hostile-dominance. No interpersonal or offense-specific factors affected the likelihood of a rupture repair.

Class, Gender, and Mobility: Unraveling the "Tangled Things."

ERIC Educational Resources Information Center

Cookson, Peter W., Jr.

1990-01-01

Reviews Sara Delamont's "Knowledgeable Women: Structuralism and the Reproduction of Elites" (1989), a feminist examination of the education of elite women which provides many insights into how gender and class operate within the dominant classes. (DM)

Mechanisms of Protein Seeding in Neurodegenerative Diseases

PubMed Central

Walker, Lary C.; Diamond, Marc I.; Duff, Karen E.; Hyman, Bradley T.

2013-01-01

Most age-associated neurodegenerative diseases involve the aggregation of specific proteins within the nervous system. In Alzheimer’s disease, the insidious pathogenic process begins many years before the symptoms emerge, and the lesions that characterize the disease – senile plaques and neurofibrillary tangles – ramify systematically through the brain. We review evidence that the β-amyloid and tau proteins, which aggregate to form senile plaques and neurofibrillary tangles, respectively, are induced to misfold and self-assemble by a process of templated conformational change that amplifies a toxic species. Recent data also indicate that the spread of these lesions from one site to another is mediated by the cellular uptake, transport and release of endogenous seeds formed by the cognate proteins. This simple pathogenic principle suggests that the formation, trafficking and metabolism of pathogenic protein seeds are promising therapeutic targets for Alzheimer’s disease and other neurodegenerative disorders. PMID:23599928

Hydrodynamical model of anisotropic, polarized turbulent superfluids. I: constraints for the fluxes

NASA Astrophysics Data System (ADS)

Mongiovì, Maria Stella; Restuccia, Liliana

2018-02-01

This work is the first of a series of papers devoted to the study of the influence of the anisotropy and polarization of the tangle of quantized vortex lines in superfluid turbulence. A thermodynamical model of inhomogeneous superfluid turbulence previously formulated is here extended, to take into consideration also these effects. The model chooses as thermodynamic state vector the density, the velocity, the energy density, the heat flux, and a complete vorticity tensor field, including its symmetric traceless part and its antisymmetric part. The relations which constrain the constitutive quantities are deduced from the second principle of thermodynamics using the Liu procedure. The results show that the presence of anisotropy and polarization in the vortex tangle affects in a substantial way the dynamics of the heat flux, and allow us to give a physical interpretation of the vorticity tensor here introduced, and to better describe the internal structure of a turbulent superfluid.

Quantum teleportation and Birman-Murakami-Wenzl algebra

NASA Astrophysics Data System (ADS)

Zhang, Kun; Zhang, Yong

2017-02-01

In this paper, we investigate the relationship of quantum teleportation in quantum information science and the Birman-Murakami-Wenzl (BMW) algebra in low-dimensional topology. For simplicity, we focus on the two spin-1/2 representation of the BMW algebra, which is generated by both the Temperley-Lieb projector and the Yang-Baxter gate. We describe quantum teleportation using the Temperley-Lieb projector and the Yang-Baxter gate, respectively, and study teleportation-based quantum computation using the Yang-Baxter gate. On the other hand, we exploit the extended Temperley-Lieb diagrammatical approach to clearly show that the tangle relations of the BMW algebra have a natural interpretation of quantum teleportation. Inspired by this interpretation, we construct a general representation of the tangle relations of the BMW algebra and obtain interesting representations of the BMW algebra. Therefore, our research sheds a light on a link between quantum information science and low-dimensional topology.

A New Probe of Line-of-sight Magnetic Field Tangling

NASA Astrophysics Data System (ADS)

Clark, S. E.

2018-04-01

The Galactic neutral hydrogen (H I ) sky at high Galactic latitudes is suffused with linear structure. Particularly prominent in narrow spectral intervals, these linear H I features are well aligned with the plane-of-sky magnetic field orientation as measured with optical starlight polarization and polarized thermal dust emission. We analyze the coherence of the orientation of these features with respect to line-of-sight velocity, and propose a new metric to quantify this H I coherence. We show that H I coherence is linearly correlated with the polarization fraction of 353 GHz dust emission. H I coherence constitutes a novel method for measuring the degree of magnetic field tangling along the line of sight in the diffuse interstellar medium. We propose applications of this property for H I -based models of the polarized dust emission in diffuse regions, and for studies of frequency decorrelation in the polarized dust foreground to the cosmic microwave background (CMB).

Anisotropic Formation of Quantum Turbulence Generated by a Vibrating Wire in Superfluid {}4{He}

NASA Astrophysics Data System (ADS)

Yano, H.; Ogawa, K.; Chiba, Y.; Obara, K.; Ishikawa, O.

2017-06-01

To investigate the formation of quantum turbulence in superfluid {}4{He}, we have studied the emission of vortex rings with a ring size of larger than 38 μm in diameter from turbulence generated by a vibrating wire. The emission rate of vortex rings from a turbulent region remains low until the beginning of high-rate emissions, suggesting that some of the vortex lines produced by the wire combine to form a vortex tangle, until an equilibrium is established between the rate of vortex line combination with the tangle and dissociation. The formation times of equilibrium turbulence are proportional to ɛ ^{-1.2} and ɛ ^{-0.6} in the directions perpendicular and parallel to the vibrating direction of the generator, respectively, indicating the anisotropic formation of turbulence. Here, ɛ is the generation power of the turbulence. This power dependence may be associated with the characteristics of quantum turbulence with a constant energy flux.

Tau Pathology Induces Excitatory Neuron Loss, Grid Cell Dysfunction and Spatial Memory Deficits Reminiscent of Early Alzheimer's Disease

PubMed Central

Fu, Hongjun; Rodriguez, Gustavo A.; Herman, Mathieu; Emrani, Sheina; Nahmani, Eden; Barrett, Geoffrey; Figueroa, Helen Y.; Goldberg, Eliana

2017-01-01

Summary The earliest stages of Alzheimer's disease (AD) are characterized by the formation of mature tangles in the entorhinal cortex and disorientation and confusion navigating familiar places. The medial entorhinal cortex (MEC) contains specialized neurons called grid cells that form part of the spatial navigation system. Here we show in a transgenic mouse model expressing mutant human tau predominantly in the EC that the formation of mature tangles in old mice was associated with excitatory cell loss and deficits in grid cell function, including destabilized grid fields and reduced firing rates, as well as altered network activity. Overt tau pathology in the aged mice was accompanied by spatial memory deficits. Therefore, tau pathology initiated in the entorhinal cortex could lead to deficits in grid cell firing and underlie the deterioration of spatial cognition seen in human AD. PMID:28111080

Brachistochrone of entanglement for spin chains

NASA Astrophysics Data System (ADS)

Carlini, Alberto; Koike, Tatsuhiko

2017-03-01

We analytically investigate the role of entanglement in time-optimal state evolution as an application of the quantum brachistochrone, a general method for obtaining the optimal time-dependent Hamiltonian for reaching a target quantum state. As a model, we treat two qubits indirectly coupled through an intermediate qubit that is directly controllable, which represents a typical situation in quantum information processing. We find the time-optimal unitary evolution law and quantify residual entanglement by the two-tangle between the indirectly coupled qubits, for all possible sets of initial pure quantum states of a tripartite system. The integrals of the motion of the brachistochrone are determined by fixing the minimal time at which the residual entanglement is maximized. Entanglement plays a role for W and Greenberger-Horne-Zeilinger (GHz) initial quantum states, and for the bi-separable initial state in which the indirectly coupled qubits have a nonzero value of the 2-tangle.

Tripartite entanglement versus tripartite nonlocality in three-qubit Greenberger-Horne-Zeilinger-class states.

PubMed

Ghose, S; Sinclair, N; Debnath, S; Rungta, P; Stock, R

2009-06-26

We analyze the relationship between tripartite entanglement and genuine tripartite nonlocality for three-qubit pure states in the Greenberger-Horne-Zeilinger class. We consider a family of states known as the generalized Greenberger-Horne-Zeilinger states and derive an analytical expression relating the three-tangle, which quantifies tripartite entanglement, to the Svetlichny inequality, which is a Bell-type inequality that is violated only when all three qubits are nonlocally correlated. We show that states with three-tangle less than 1/2 do not violate the Svetlichny inequality. On the other hand, a set of states known as the maximal slice states does violate the Svetlichny inequality, and exactly analogous to the two-qubit case, the amount of violation is directly related to the degree of tripartite entanglement. We discuss further interesting properties of the generalized Greenberger-Horne-Zeilinger and maximal slice states.

Provider ambivalence about using forensic medical evaluation to respond to child abuse: A content and discourse analysis.

PubMed

Morris, Marian; Rivaux, Stephanie; Faulkner, Monica

2017-03-01

Forensic medical evaluation rates for child abuse victims in Texas are low relative to national rates. In exploring reasons, researchers collected quantitative and qualitative interview and focus group data from multidisciplinary child abuse response team members across the state. This paper presents results of a secondary analysis of (N=19) health care providers' interview and focus group transcripts, looking specifically at experiences with conducting forensic evaluations - thoughts, struggles, and ethical issues. The analysis was conducted from a critical realist perspective using content and discourse analysis. A theme of ambivalence was identified and explored. Three discursive themes were identified: ambivalence about the legal role, the health care role, and about unintended outcomes of evaluations. Extra-discursive elements related to the physical body, resource distribution, and funding policy were examined for their interaction with discursive patterns. Implications of findings include addressing issues in the current approach to responding to child abuse (e.g., uniting around common definitions of abuse; refining parameters for when FME is helpful; shoring up material resources for the abuse response infrastructure) and considering modification of providers' roles and activities relative to forensic work (e.g., deploying providers for prevention activities versus reactive activities). Copyright © 2017 Elsevier Ltd. All rights reserved.

Power lines: Derrida, discursive psychology and the management of accusations of teacher bullying.

PubMed

Hepburn, A

2000-12-01

This study connects broad issues of classroom control and the disciplining of pupils by teachers with a detailed examination of the way teachers deal with an implied accusation that they have been bullying. The analysis of interviews develops with reference to discursive psychology and Derrida's development of deconstruction. Billig's (1992) insights into ways that participants' accounts can neutralize threats to established social arrangements are employed in relating detailed analytic points to the broader power relations between teacher and pupil. Interviews were conducted with Scottish secondary school teachers, and subjected to close textual analysis. This resulted in the development of three themes: (1) Subjectivity Construction, in which the functional role of the construction of mental entities is examined; (2) Normalizing Techniques, identifying strategies whereby intimidation can be constructed as normal; and (3) Figuration, examining the utility of figurative language--metaphors, maxims, and so on. These themes display the subtlety and complexity of teachers' strategies for distancing themselves from being held accountable for reported intimidation. To conclude, three broader features of the study are discussed: the contribution to discursive psychology that Derrida's deconstructive philosophy can make; the respecification of psychology and subjectivity as participants' resources for action; and the contribution that this type of detailed study can make to issues of power and social critique.

Politics and the struggle to define: a discourse analysis of the framing strategies of competing actors in a 'new' participatory forum.

PubMed

Skillington, T

1997-09-01

On account of the current wave of environmental consciousness, the state is adapting to the phenomena of systems of negotiations outside of the traditional institutional framework on environmental issues in an attempt to preserve cultural support. However recent experiments in discursive democracy have proven to be a modality for the transmission of productivist culture and for the reassertion of corporatist tendencies. This interpretation finds support here primarily through a discourse analysis based on a three-dimensional framework. The analysis begins by examining the structure of discursive formations of various participating actors at the Irish National Recycling Conference in 1993, and explores the ways in which actors struggled at the symbolic level to define the rules constitutive of this space of play. It argues from the perspective of discourse as social practice and justifies this approach by assessing the degree of synchronization between collective actors' systems of discursivity and the socially structured institutional sites within which they are embedded. Finally, by examining the position of this field vis-à-vis the field of political power, this research will show how broader relations of domination and traditional power asymmetries came to be reasserted in a 'new' participatory arrangement.

Estimating rupture distances without a rupture

USGS Publications Warehouse

Thompson, Eric M.; Worden, Charles

2017-01-01

Most ground motion prediction equations (GMPEs) require distances that are defined relative to a rupture model, such as the distance to the surface projection of the rupture (RJB) or the closest distance to the rupture plane (RRUP). There are a number of situations in which GMPEs are used where it is either necessary or advantageous to derive rupture distances from point-source distance metrics, such as hypocentral (RHYP) or epicentral (REPI) distance. For ShakeMap, it is necessary to provide an estimate of the shaking levels for events without rupture models, and before rupture models are available for events that eventually do have rupture models. In probabilistic seismic hazard analysis, it is often convenient to use point-source distances for gridded seismicity sources, particularly if a preferred orientation is unknown. This avoids the computationally cumbersome task of computing rupture-based distances for virtual rupture planes across all strikes and dips for each source. We derive average rupture distances conditioned on REPI, magnitude, and (optionally) back azimuth, for a variety of assumed seismological constraints. Additionally, we derive adjustment factors for GMPE standard deviations that reflect the added uncertainty in the ground motion estimation when point-source distances are used to estimate rupture distances.

High-order computer-assisted estimates of topological entropy

NASA Astrophysics Data System (ADS)

Grote, Johannes

The concept of Taylor Models is introduced, which offers highly accurate C0-estimates for the enclosures of functional dependencies, combining high-order Taylor polynomial approximation of functions and rigorous estimates of the truncation error, performed using verified interval arithmetic. The focus of this work is on the application of Taylor Models in algorithms for strongly nonlinear dynamical systems. A method to obtain sharp rigorous enclosures of Poincare maps for certain types of flows and surfaces is developed and numerical examples are presented. Differential algebraic techniques allow the efficient and accurate computation of polynomial approximations for invariant curves of certain planar maps around hyperbolic fixed points. Subsequently we introduce a procedure to extend these polynomial curves to verified Taylor Model enclosures of local invariant manifolds with C0-errors of size 10-10--10 -14, and proceed to generate the global invariant manifold tangle up to comparable accuracy through iteration in Taylor Model arithmetic. Knowledge of the global manifold structure up to finite iterations of the local manifold pieces enables us to find all homoclinic and heteroclinic intersections in the generated manifold tangle. Combined with the mapping properties of the homoclinic points and their ordering we are able to construct a subshift of finite type as a topological factor of the original planar system to obtain rigorous lower bounds for its topological entropy. This construction is fully automatic and yields homoclinic tangles with several hundred homoclinic points. As an example rigorous lower bounds for the topological entropy of the Henon map are computed, which to the best knowledge of the authors yield the largest such estimates published so far.

Primary age-related tauopathy (PART): a common pathology associated with human aging

PubMed Central

Crary, John F.; Trojanowski, John Q.; Schneider, Julie A.; Abisambra, Jose F.; Abner, Erin L.; Alafuzoff, Irina; Arnold, Steven E.; Attems, Johannes; Beach, Thomas G.; Bigio, Eileen H.; Cairns, Nigel J.; Dickson, Dennis W.; Gearing, Marla; Grinberg, Lea T.; Hof, Patrick R.; Hyman, Bradley T.; Jellinger, Kurt; Jicha, Gregory A.; Kovacs, Gabor G.; Knopman, David S.; Kofler, Julia; Kukull, Walter A.; Mackenzie, Ian R.; Masliah, Eliezer; McKee, Ann; Montine, Thomas J.; Murray, Melissa E.; Neltner, Janna H.; Santa-Maria, Ismael; Seeley, William W.; Serrano-Pozo, Alberto; Shelanski, Michael L.; Stein, Thor; Takao, Masaki; Thal, Dietmar R.; Toledo, Jonathan B.; Troncoso, Juan C.; Vonsattel, Jean Paul; White, Charles L.; Wisniewski, Thomas; Woltjer, Randall L.; Yamada, Masahito; Nelson, Peter T.

2014-01-01

We recommend a new term, “primary age-related tauopathy” (PART), to describe a pathology that is commonly observed in the brains of aged individuals. Many autopsy studies have reported brains with neurofibrillary tangles (NFT) that are indistinguishable from those of Alzheimer's disease (AD), in the absence of amyloid (Aβ) plaques. For these “NFT+/Aβ−” brains, for which formal criteria for AD neuropathologic changes are not met, the NFT are mostly restricted to structures in the medial temporal lobe, basal forebrain, brainstem, and olfactory areas (bulb and cortex). Symptoms in persons with PART usually range from normal to amnestic cognitive changes, with only a minority exhibiting profound impairment. Because cognitive impairment is often mild, existing clinicopathologic designations, such as “tangle-only dementia” and “tangle-predominant senile dementia”, are imprecise and not appropriate for most subjects. PART is almost universally detectable at autopsy among elderly individuals, yet this pathological process cannot be specifically identified pre-mortem at the present time. Improved biomarkers and tau imaging may enable diagnosis of PART in clinical settings in the future. Indeed, recent studies have identified a common biomarker profile consisting of temporal lobe atrophy and tauopathy without evidence of Aβ accumulation. For both researchers and clinicians, a revised nomenclature will raise awareness of this extremely common pathologic change while providing a conceptual foundation for future studies. Prior reports that have elucidated features of the pathologic entity we refer to as PART are discussed, and working neuropathological diagnostic criteria are proposed. PMID:25348064

'You become a man in a man's world': is there discursive space for women in surgery?

PubMed

Hill, Elspeth; Solomon, Yvette; Dornan, Tim; Stalmeijer, Renée

2015-12-01

The UK set a target of 20% of the surgical consultant workforce to be represented by women by 2009; in 2012, it remains 7%. Studies have attributed this shortfall to the nature of careers in surgery and differing career aspirations among women. Rather than exploring barriers to participation, this study aims to explore the self-narratives of those women who do undertake surgical careers and who do come to see themselves as surgeons. The study comprises 15 individual interviews with women in surgical careers, from those aspiring to be surgeons, to senior and retired surgeons. Data were explored using discourse analysis with a priori themes derived from the literature on women in surgery and Holland et al.'s theoretical framework of Figured Worlds. Discourses of being a surgeon and discourses of being a woman, existed in competition. Female surgeons figured surgery as a career requiring 100% dedication, as they did motherhood, although the demands of the two roles differed and consequently the roles were not discursively compatible. Many related powerfully negative experiences in which their gender had marked them out as 'other' within surgery. Women described how they were expected to show masculine traits as surgeons and the ways to consequently become legitimate in the surgical world as a 'woman surgeon'. They found creative ways to articulate how women in general, and feminine qualities in particular, enhanced surgery. Finally, some women engaged in identity work, termed 'world making', - the creative orchestration of discourses of surgeonhood and motherhood to be mutually sustaining. There is little discursive space in which to be both a successful woman and a successful surgeon. Those who combine these roles must either be innovative in refiguring what it means to be a woman or what it means to be a surgeon, or they must author a new space for themselves, a powerful discursive process termed 'world making'. © 2015 John Wiley & Sons Ltd.

Analysis of 30 breast implant rupture cases.

PubMed

Tark, Kwan Chul; Jeong, Hii Sun; Roh, Tae Suk; Choi, Jong Woo

2005-01-01

Breast implants used for augmentation mammoplasty or breast reconstruction could rupture from various causes such as trauma or spontaneous failure. The objectives of this study were to investigate the relationships between the causes of implant rupture and the degree of capsular contracture, and then to evaluate the relative efficacies of specific signs on magnetic resonance imaging (MRI) known to be beneficial for diagnosing the rupture. A retrospective review identified patients with prosthetic implant rupture or impending rupture treated by the senior author. The 30 cases of implant rupture available for review were classified into two groups: intracapsular and extracapsular ruptures. The 30 cases of breast implant ruptures were analyzed with respect to the clinical symptoms and signs, the causes of rupture, the degree of capsular contracture, and therapeutic plans. Among the 30 cases, 14 patients who had undergone MRI during the diagnostic period were analyzed with respect to the relationships between MRI readings and operative findings. Spontaneous rupture of membranes was most common (80%), followed by failure because of trauma (7%) and valve or implant base (4%). The symptoms during implant rupture were contour deformity, palpated mass-like lesions, pain, and focal inflammation. According to the analysis of specific MRI signs, the sensitivity and specificity of the linguine sign were 87% and 100%, respectively, for intracapsular rupture. For extracapsular rupture, the sensitivity and specificity of the linguine sign were, respectively, 67% and 75%. The sensitivity and specificity of the rat-tail sign and tear drop sign were 14% and 50%, respectively. Breast implant rupture was correlated with the degree of capsular contracture in our study. Among the various specific MRI signs used in diagnosing the rupture, the linguine sign was reliable and had a high sensitivity and specificity, especially in cases of intracapsular rupture. On the other hand, the rat-tail and tear drop signs were nonspecific signs for diagnosing the rupture of breast implant.

Alliance ruptures and rupture resolution in cognitive-behavior therapy: a preliminary task analysis.

PubMed

Aspland, Helen; Llewelyn, Susan; Hardy, Gillian E; Barkham, Michael; Stiles, William

2008-11-01

An initial ideal, rational model of alliance rupture and rupture resolution provided by cognitive-behavioral therapy (CBT) experts was assessed and compared with empirical observations of ruptures and their resolution in two cases of successful CBT. The initial rational model emphasized nondefensive acknowledgment and exploration of the rupture. Results indicated differences between what therapists think they should do to resolve ruptures and what they actually do and suggested that the rational model should be expanded to emphasize client validation and empowerment. Therapists' ability to attend to ruptures emerged as an important clinical skill.

Liver Hemangioma

MedlinePlus

Liver hemangioma Overview A liver hemangioma (he-man-jee-O-muh) is a noncancerous (benign) mass in the liver. A liver hemangioma is made up of a tangle of blood vessels. Other terms for a liver hemangioma are hepatic hemangioma and cavernous hemangioma. Most ...

Association between Traumatic Brain Injury and Late Life Neurodegenerative Conditions and Neuropathological Findings

PubMed Central

Crane, Paul K.; Gibbons, Laura E.; Dams-O’Connor, Kristen; Trittschuh, Emily; Leverenz, James B.; Keene, C. Dirk; Sonnen, Joshua; Montine, Thomas J.; Bennett, David A.; Leurgans, Sue; Schneider, Julie A.; Larson, Eric B.

2016-01-01

IMPORTANCE There is great interest in the late effects of traumatic brain injury (TBI). OBJECTIVE To determine whether TBI with loss of consciousness (LOC) is associated with increased risk for clinical and neuropathological findings of Alzheimer’s disease, Parkinson’s disease, and other dementias. Our primary hypothesis was that TBI with LOC would be associated with increased risk for Alzheimer’s disease and neurofibrillary tangles. DESIGN Prospective cohort studies which follow all participants (Religious Orders Study and the Memory and Aging Project, ROS and MAP) or all consenting participants (Adult Changes in Thought, ACT) to autopsy. Studies performed annual (ROS and MAP) or biennial (ACT) cognitive and clinical testing to identify incident cases of dementia and Alzheimer’s disease. SETTING Members of a Seattle-area healthcare delivery system (ACT); priests and nuns living in orders across the US (ROS), and Chicago-area adults in retirement communities (MAP). PARTICIPANTS 7,130 older adults; 1,589 came to autopsy. EXPOSURE Self reported TBI reported when free of dementia, categorized as <1 hour vs. > 1 hour of LOC. MAIN OUTCOMES AND MEASURES Clinical: incident all-cause dementia, Alzheimer’s disease, and Parkinson’s disease (all studies), and incident mild cognitive impairment and progression of parkinsonian signs (ROS and MAP). Neuropathology: neurofibrillary tangles, neuritic plaques, microinfarcts, cystic infarcts, Lewy bodies, and hippocampal sclerosis (all studies). RESULTS 865 participants reported a history of TBI with LOC. In >45,000 person-years of follow-up, there were 1,537 incident dementia and 117 incident Parkinson’s disease cases. There was no association between TBI with LOC and incident dementia or Alzheimer’s disease. There were associations between TBI with LOC and incident Parkinson’s disease and progression of parkinsonian signs. There was no association between TBI with LOC and neurofibrillary tangles or neuritic plaques. There was an association between TBI with LOC and Lewy bodies, and with microinfarcts, though numbers of people with these findings were small. CONCLUSIONS AND RELEVANCE Pooled clinical and neuropathology data from three prospective cohort studies indicate that TBI with LOC is associated with risk of Lewy body accumulation, progression of parkinsonism, and Parkinson’s disease, but not dementia, Alzheimer’s disease, neuritic plaques, or neurofibrillary tangles. PMID:27400367

Rupture of the Pitáycachi Fault in the 1887 Mw 7.5 Sonora, Mexico earthquake (southern Basin-and-Range Province): Rupture kinematics and epicenter inferred from rupture branching patterns

NASA Astrophysics Data System (ADS)

Suter, Max

2015-01-01

During the 3 May 1887 Mw 7.5 Sonora earthquake (surface rupture end-to-end length: 101.8 km), an array of three north-south striking Basin-and-Range Province faults (from north to south Pitáycachi, Teras, and Otates) slipped sequentially along the western margin of the Sierra Madre Occidental Plateau. This detailed field survey of the 1887 earthquake rupture zone along the Pitáycachi fault includes mapping the rupture scarp and measurements of surface deformation. The surface rupture has an endpoint-to-endpoint length of ≥41.0 km, dips 70°W, and is characterized by normal left-lateral extension. The maximum surface offset is 487 cm and the mean offset 260 cm. The rupture trace shows a complex pattern of second-order segmentation. However, this segmentation is not expressed in the 1887 along-rupture surface offset profile, which indicates that the secondary segments are linked at depth into a single coherent fault surface. The Pitáycachi surface rupture shows a well-developed bipolar branching pattern suggesting that the rupture originated in its central part, where the polarity of the rupture bifurcations changes. Most likely the rupture first propagated bilaterally along the Pitáycachi fault. The southern rupture front likely jumped across a step over to the Teras fault and from there across a major relay zone to the Otates fault. Branching probably resulted from the lateral propagation of the rupture after breaching the seismogenic part of the crust, given that the much shorter ruptures of the Otates and Teras segments did not develop branches.

A Retrospective Analysis of Ruptured Breast Implants

PubMed Central

Baek, Woo Yeol; Lew, Dae Hyun

2014-01-01

Background Rupture is an important complication of breast implants. Before cohesive gel silicone implants, rupture rates of both saline and silicone breast implants were over 10%. Through an analysis of ruptured implants, we can determine the various factors related to ruptured implants. Methods We performed a retrospective review of 72 implants that were removed for implant rupture between 2005 and 2014 at a single institution. The following data were collected: type of implants (saline or silicone), duration of implantation, type of implant shell, degree of capsular contracture, associated symptoms, cause of rupture, diagnostic tools, and management. Results Forty-five Saline implants and 27 silicone implants were used. Rupture was diagnosed at a mean of 5.6 and 12 years after insertion of saline and silicone implants, respectively. There was no association between shell type and risk of rupture. Spontaneous was the most common reason for the rupture. Rupture management was implant change (39 case), microfat graft (2 case), removal only (14 case), and follow-up loss (17 case). Conclusions Saline implants have a shorter average duration of rupture, but diagnosis is easier and safer, leading to fewer complications. Previous-generation silicone implants required frequent follow-up observation, and it is recommended that they be changed to a cohesive gel implant before hidden rupture occurs. PMID:25396188

Rupture directivity of moderate earthquakes in northern California

USGS Publications Warehouse

Seekins, Linda C.; Boatwright, John

2010-01-01

We invert peak ground velocity and acceleration (PGV and PGA) to estimate rupture direction and rupture velocity for 47 moderate earthquakes (3.5≥M≥5.4) in northern California. We correct sets of PGAs and PGVs recorded at stations less than 55–125 km, depending on source depth, for site amplification and source–receiver distance, then fit the residual peak motions to the unilateral directivity function of Ben-Menahem (1961). We independently invert PGA and PGV. The rupture direction can be determined using as few as seven peak motions if the station distribution is sufficient. The rupture velocity is unstable, however, if there are no takeoff angles within 30° of the rupture direction. Rupture velocities are generally subsonic (0.5β–0.9β); for stability, we limit the rupture velocity at v=0.92β, the Rayleigh wave speed. For 73 of 94 inversions, the rupture direction clearly identifies one of the nodal planes as the fault plane. The 35 strike-slip earthquakes have rupture directions that range from nearly horizontal (6 events) to directly updip (5 events); the other 24 rupture partly along strike and partly updip. Two strike-slip earthquakes rupture updip in one inversion and downdip in the other. All but 1 of the 11 thrust earthquakes rupture predominantly updip. We compare the rupture directions for 10 M≥4.0 earthquakes to the relative location of the mainshock and the first two weeks of aftershocks. Spatial distributions of 8 of 10 aftershock sequences agree well with the rupture directivity calculated for the mainshock.

An insight on correlations between kinematic rupture parameters from dynamic ruptures on rough faults

NASA Astrophysics Data System (ADS)

Thingbijam, Kiran Kumar; Galis, Martin; Vyas, Jagdish; Mai, P. Martin

2017-04-01

We examine the spatial interdependence between kinematic parameters of earthquake rupture, which include slip, rise-time (total duration of slip), acceleration time (time-to-peak slip velocity), peak slip velocity, and rupture velocity. These parameters were inferred from dynamic rupture models obtained by simulating spontaneous rupture on faults with varying degree of surface-roughness. We observe that the correlations between these parameters are better described by non-linear correlations (that is, on logarithm-logarithm scale) than by linear correlations. Slip and rise-time are positively correlated while these two parameters do not correlate with acceleration time, peak slip velocity, and rupture velocity. On the other hand, peak slip velocity correlates positively with rupture velocity but negatively with acceleration time. Acceleration time correlates negatively with rupture velocity. However, the observed correlations could be due to weak heterogeneity of the slip distributions given by the dynamic models. Therefore, the observed correlations may apply only to those parts of rupture plane with weak slip heterogeneity if earthquake-rupture associate highly heterogeneous slip distributions. Our findings will help to improve pseudo-dynamic rupture generators for efficient broadband ground-motion simulations for seismic hazard studies.

Rupture process of the 2013 Okhotsk deep mega earthquake from iterative backprojection and compress sensing methods

NASA Astrophysics Data System (ADS)

Qin, W.; Yin, J.; Yao, H.

2013-12-01

On May 24th 2013 a Mw 8.3 normal faulting earthquake occurred at a depth of approximately 600 km beneath the sea of Okhotsk, Russia. It is a rare mega earthquake that ever occurred at such a great depth. We use the time-domain iterative backprojection (IBP) method [1] and also the frequency-domain compressive sensing (CS) technique[2] to investigate the rupture process and energy radiation of this mega earthquake. We currently use the teleseismic P-wave data from about 350 stations of USArray. IBP is an improved method of the traditional backprojection method, which more accurately locates subevents (energy burst) during earthquake rupture and determines the rupture speeds. The total rupture duration of this earthquake is about 35 s with a nearly N-S rupture direction. We find that the rupture is bilateral in the beginning 15 seconds with slow rupture speeds: about 2.5km/s for the northward rupture and about 2 km/s for the southward rupture. After that, the northward rupture stopped while the rupture towards south continued. The average southward rupture speed between 20-35 s is approximately 5 km/s, lower than the shear wave speed (about 5.5 km/s) at the hypocenter depth. The total rupture length is about 140km, in a nearly N-S direction, with a southward rupture length about 100 km and a northward rupture length about 40 km. We also use the CS method, a sparse source inversion technique, to study the frequency-dependent seismic radiation of this mega earthquake. We observe clear along-strike frequency dependence of the spatial and temporal distribution of seismic radiation and rupture process. The results from both methods are generally similar. In the next step, we'll use data from dense arrays in southwest China and also global stations for further analysis in order to more comprehensively study the rupture process of this deep mega earthquake. Reference [1] Yao H, Shearer P M, Gerstoft P. Subevent location and rupture imaging using iterative backprojection for the 2011 Tohoku Mw 9.0 earthquake. Geophysical Journal International, 2012, 190(2): 1152-1168. [2]Yao H, Gerstoft P, Shearer P M, et al. Compressive sensing of the Tohoku-Oki Mw 9.0 earthquake: Frequency-dependent rupture modes. Geophysical Research Letters, 2011, 38(20).

Persistent rupture terminations at a restraining bend from slip rates on the eastern Altyn Tagh fault

NASA Astrophysics Data System (ADS)

Elliott, A. J.; Oskin, M. E.; Liu-zeng, J.; Shao, Y.-X.

2018-05-01

Restraining double-bends along strike-slip faults inhibit or permit throughgoing ruptures depending on bend angle, length, and prior rupture history. Modeling predicts that for mature strike-slip faults in a regional stress regime characterized by simple shear, a restraining bend of >18° and >4 km length impedes propagating rupture. Indeed, natural evidence shows that the most recent rupture(s) of the Xorkoli section (90°-93°E) of the eastern Altyn Tagh fault (ATF) ended at large restraining bends. However, when multiple seismic cycles are considered in numerical dynamic rupture modeling, heterogeneous residual stresses enable some ruptures to propagate further, modulating whether the bends persistently serve as barriers. These models remain to be tested using observations of the cumulative effects of multiple earthquake ruptures. Here we investigate whether a large restraining double-bend on the ATF serves consistently as a barrier to rupture by measuring long-term slip rates around the terminus of its most recent surface rupture at the Aksay bend. Our results show a W-E decline in slip as the SATF enters the bend, as would be predicted from repeated rupture terminations there. Prior work demonstrated no Holocene slip on the central, most misoriented portion of the bend, while 19-79 m offsets suggest that multiple ruptures have occurred on the west side of the bend during the Holocene. Thus we conclude the gradient in the SATF's slip rate results from the repeated termination of earthquake ruptures there. However, a finite slip rate east of the bend represents the transmission of some slip, suggesting that a small fraction of ruptures may fully traverse or jump the double-bend. This agreement between natural observations of slip accumulation and multi-cycle models of fault rupture enables us to translate observed slip rates into insight about the dynamic rupture process of individual earthquakes as they encounter geometric complexities along faults.

Fault Branching and Long-Term Earthquake Rupture Scenario for Strike-Slip Earthquake

NASA Astrophysics Data System (ADS)

Klinger, Y.; CHOI, J. H.; Vallage, A.

2017-12-01

Careful examination of surface rupture for large continental strike-slip earthquakes reveals that for the majority of earthquakes, at least one major branch is involved in the rupture pattern. Often, branching might be either related to the location of the epicenter or located toward the end of the rupture, and possibly related to the stopping of the rupture. In this work, we examine large continental earthquakes that show significant branches at different scales and for which ground surface rupture has been mapped in great details. In each case, rupture conditions are described, including dynamic parameters, past earthquakes history, and regional stress orientation, to see if the dynamic stress field would a priori favor branching. In one case we show that rupture propagation and branching are directly impacted by preexisting geological structures. These structures serve as pathways for the rupture attempting to propagate out of its shear plane. At larger scale, we show that in some cases, rupturing a branch might be systematic, hampering possibilities for the development of a larger seismic rupture. Long-term geomorphology hints at the existence of a strong asperity in the zone where the rupture branched off the main fault. There, no evidence of throughgoing rupture could be seen along the main fault, while the branch is well connected to the main fault. This set of observations suggests that for specific configurations, some rupture scenarios involving systematic branching are more likely than others.

Images, femininity and cancer: an analysis of an international patient education programme.

PubMed

Phillips, Catherine

2009-01-01

This article is an analysis of a cancer patient education programme run by cosmetic companies. I focus on an analysis of imagery, arguing that there are particular discursive elements that the cosmetic companies use in order to make productive the relationship between femininity and cancer. I contextualize this education programme by presenting the controversies regarding cosmetics as they relate to the growth of breast tumours. In doing so, I conclude that conversations and questions about a link between chemicals and cancer are subverted by both ;horror' narratives of cancer and the provocative use of standards of beauty. Such discursive dominance in patient education programmes makes it difficult to engage in a more public understanding of cancer growth as affected by cosmetic chemicals.

Rethinking Public Health: Promoting Public Engagement Through a New Discursive Environment

PubMed Central

2014-01-01

I reexamine the notion of public health after reviewing critiques of the prevalent individualistic conception of health. I argue that public health should mean not only the health of the public but also health in the public and by the public, and I expound on the social contingency of health and highlight the importance of the interpersonal dimensions of health conditions and health promotion efforts. Promoting public health requires activating health-enhancing communicative behaviors (such as interpersonal advocacy and mutual responsibility taking) in addition to individual behavioral change. To facilitate such communicative behaviors, it is imperative to first construct a new discursive environment in which to think and talk about health in a language of interdependence and collective efforts. PMID:24228674

Rethinking public health: promoting public engagement through a new discursive environment.

PubMed

Sun, Ye

2014-01-01

I reexamine the notion of public health after reviewing critiques of the prevalent individualistic conception of health. I argue that public health should mean not only the health of the public but also health in the public and by the public, and I expound on the social contingency of health and highlight the importance of the interpersonal dimensions of health conditions and health promotion efforts. Promoting public health requires activating health-enhancing communicative behaviors (such as interpersonal advocacy and mutual responsibility taking) in addition to individual behavioral change. To facilitate such communicative behaviors, it is imperative to first construct a new discursive environment in which to think and talk about health in a language of interdependence and collective efforts.

Ground motion hazard from supershear rupture

USGS Publications Warehouse

Andrews, D.J.

2010-01-01

An idealized rupture, propagating smoothly near a terminal rupture velocity, radiates energy that is focused into a beam. For rupture velocity less than the S-wave speed, radiated energy is concentrated in a beam of intense fault-normal velocity near the projection of the rupture trace. Although confined to a narrow range of azimuths, this beam diverges and attenuates. For rupture velocity greater than the S-wave speed, radiated energy is concentrated in Mach waves forming a pair of beams propagating obliquely away from the fault. These beams do not attenuate until diffraction becomes effective at large distance. Events with supershear and sub-Rayleigh rupture velocity are compared in 2D plane-strain calculations with equal stress drop, fracture energy, and rupture length; only static friction is changed to determine the rupture velocity. Peak velocity in the sub-Rayleigh case near the termination of rupture is larger than peak velocity in the Mach wave in the supershear case. The occurrence of supershear rupture propagation reduces the most intense peak ground velocity near the fault, but it increases peak velocity within a beam at greater distances.

In Search of the Object: Historiography and Adult Education.

ERIC Educational Resources Information Center

Welton, Michael R.

1993-01-01

Historical inquiry in adult education is tangled up with contemporary debates about the nature of the field as a discipline. The problem of object and the problem of usability must be considered for historical insights to inform the field. (SK)

Module isolation devices

DOEpatents

Carolan, Michael Francis; Cooke, John Albert; Buzinski, Michael David

2010-04-27

A gas flow isolation device includes a gas flow isolation valve movable from an opened condition to a closed condition. The module isolation valve in one embodiment includes a rupture disk in flow communication with a flow of gas when the module isolation valve is in an opened condition. The rupture disk ruptures when a predetermined pressure differential occurs across it causing the isolation valve to close. In one embodiment the valve is mechanically linked to the rupture disk to maintain the valve in an opened condition when the rupture disk is intact, and which permits the valve to move into a closed condition when the rupture disk ruptures. In another embodiment a crushable member maintains the valve in an open condition, and the flow of gas passed the valve upon rupturing of the rupture disk compresses the crushable member to close the isolation valve.

Slow rupture of frictional interfaces

NASA Astrophysics Data System (ADS)

Bar Sinai, Yohai; Brener, Efim A.; Bouchbinder, Eran

2012-02-01

The failure of frictional interfaces and the spatiotemporal structures that accompany it are central to a wide range of geophysical, physical and engineering systems. Recent geophysical and laboratory observations indicated that interfacial failure can be mediated by slow slip rupture phenomena which are distinct from ordinary, earthquake-like, fast rupture. These discoveries have influenced the way we think about frictional motion, yet the nature and properties of slow rupture are not completely understood. We show that slow rupture is an intrinsic and robust property of simple non-monotonic rate-and-state friction laws. It is associated with a new velocity scale cmin, determined by the friction law, below which steady state rupture cannot propagate. We further show that rupture can occur in a continuum of states, spanning a wide range of velocities from cmin to elastic wave-speeds, and predict different properties for slow rupture and ordinary fast rupture. Our results are qualitatively consistent with recent high-resolution laboratory experiments and may provide a theoretical framework for understanding slow rupture phenomena along frictional interfaces.

The influence of atmospheric pressure on aortic aneurysm rupture--is the diameter of the aneurysm important?

PubMed

Urbanek, Tomasz; Juśko, Maciej; Niewiem, Alfred; Kuczmik, Wacław; Ziaja, Damian; Ziaja, Krzysztof

2015-01-01

The rate of aortic aneurysm rupture correlates with the aneurysm's diameter, and a higher rate of rupture is observed in patients with larger aneurysms. According to the literature, contradictory results concerning the relationship between atmospheric pressure and aneurysm size have been reported. In this paper, we assessed the influence of changes in atmospheric pressure on abdominal aneurysm ruptures in relationship to the aneurysm's size. The records of 223 patients with ruptured abdominal aneurysms were evaluated. All of the patients had been admitted to the department in the period 1997-2007 from the Silesia region. The atmospheric pressures on the day of the rupture and on the days both before the rupture and between the rupture events were compared. The size of the aneurysm was also considered in the analysis. There were no statistically significant differences in pressure between the days of rupture and the remainder of the days within an analysed period. The highest frequency of the admission of patients with a ruptured aortic aneurysm was observed during periods of winter and spring, when the highest mean values of atmospheric pressure were observed; however, this observation was not statistically confirmed. A statistically non-significant trend towards the higher rupture of large aneurysms (> 7 cm) was observed in the cases where the pressure increased between the day before the rupture and the day of the rupture. This trend was particularly pronounced in patients suffering from hypertension (p = 0.1). The results of this study do not support the hypothesis that there is a direct link between atmospheric pressure values and abdominal aortic aneurysm ruptures.

Spatiotemporal complexity of 2-D rupture nucleation process observed by direct monitoring during large-scale biaxial rock friction experiments

NASA Astrophysics Data System (ADS)

Fukuyama, Eiichi; Tsuchida, Kotoyo; Kawakata, Hironori; Yamashita, Futoshi; Mizoguchi, Kazuo; Xu, Shiqing

2018-05-01

We were able to successfully capture rupture nucleation processes on a 2-D fault surface during large-scale biaxial friction experiments using metagabbro rock specimens. Several rupture nucleation patterns have been detected by a strain gauge array embedded inside the rock specimens as well as by that installed along the edge walls of the fault. In most cases, the unstable rupture started just after the rupture front touched both ends of the rock specimen (i.e., when rupture front extended to the entire width of the fault). In some cases, rupture initiated at multiple locations and the rupture fronts coalesced to generate unstable ruptures, which could only be detected from the observation inside the rock specimen. Therefore, we need to carefully examine the 2-D nucleation process of the rupture especially when analyzing the data measured only outside the rock specimen. At least the measurements should be done at both sides of the fault to identify the asymmetric rupture propagation on the fault surface, although this is not perfect yet. In the present experiment, we observed three typical types of the 2-D rupture propagation patterns, two of which were initiated at a single location either close to the fault edge or inside the fault. This initiation could be accelerated by the free surface effect at the fault edge. The third one was initiated at multiple locations and had a rupture coalescence at the middle of the fault. These geometrically complicated rupture initiation patterns are important for understanding the earthquake nucleation process in nature.

The transition of dynamic rupture styles in elastic media under velocity-weakening friction

NASA Astrophysics Data System (ADS)

Gabriel, A.-A.; Ampuero, J.-P.; Dalguer, L. A.; Mai, P. M.

2012-09-01

Although kinematic earthquake source inversions show dominantly pulse-like subshear rupture behavior, seismological observations, laboratory experiments and theoretical models indicate that earthquakes can operate with different rupture styles: either as pulses or cracks, that propagate at subshear or supershear speeds. The determination of rupture style and speed has important implications for ground motions and may inform about the state of stress and strength of active fault zones. We conduct 2D in-plane dynamic rupture simulations with a spectral element method to investigate the diversity of rupture styles on faults governed by velocity-and-state-dependent friction with dramatic velocity-weakening at high slip rate. Our rupture models are governed by uniform initial stresses, and are artificially initiated. We identify the conditions that lead to different rupture styles by investigating the transitions between decaying, steady state and growing pulses, cracks, sub-shear and super-shear ruptures as a function of background stress, nucleation size and characteristic velocity at the onset of severe weakening. Our models show that small changes of background stress or nucleation size may lead to dramatic changes of rupture style. We characterize the asymptotic properties of steady state and self-similar pulses as a function of background stress. We show that an earthquake may not be restricted to a single rupture style, but that complex rupture patterns may emerge that consist of multiple rupture fronts, possibly involving different styles and back-propagating fronts. We also demonstrate the possibility of a super-shear transition for pulse-like ruptures. Finally, we draw connections between our findings and recent seismological observations.

The effect of segmented fault zones on earthquake rupture propagation and termination

NASA Astrophysics Data System (ADS)

Huang, Y.

2017-12-01

A fundamental question in earthquake source physics is what can control the nucleation and termination of an earthquake rupture. Besides stress heterogeneities and variations in frictional properties, damaged fault zones (DFZs) that surround major strike-slip faults can contribute significantly to earthquake rupture propagation. Previous earthquake rupture simulations usually characterize DFZs as several-hundred-meter-wide layers with lower seismic velocities than host rocks, and find earthquake ruptures in DFZs can exhibit slip pulses and oscillating rupture speeds that ultimately enhance high-frequency ground motions. However, real DFZs are more complex than the uniform low-velocity structures, and show along-strike variations of damages that may be correlated with historical earthquake ruptures. These segmented structures can either prohibit or assist rupture propagation and significantly affect the final sizes of earthquakes. For example, recent dense array data recorded at the San Jacinto fault zone suggests the existence of three prominent DFZs across the Anza seismic gap and the south section of the Clark branch, while no prominent DFZs were identified near the ends of the Anza seismic gap. To better understand earthquake rupture in segmented fault zones, we will present dynamic rupture simulations that calculate the time-varying rupture process physically by considering the interactions between fault stresses, fault frictional properties, and material heterogeneities. We will show that whether an earthquake rupture can break through the intact rock outside the DFZ depend on the nucleation size of the earthquake and the rupture propagation distance in the DFZ. Moreover, material properties of the DFZ, stress conditions along the fault, and friction properties of the fault also have a critical impact on rupture propagation and termination. We will also present scenarios of San Jacinto earthquake ruptures and show the parameter space that is favorable for rupture propagation through the Anza seismic gap. Our results suggest that a priori knowledge of properties of segmented fault zones is of great importance for predicting sizes of future large earthquakes on major faults.

The Tangle of Student Allowances.

ERIC Educational Resources Information Center

Thomson, Norman J.

1980-01-01

A discussion of the distribution of student financial aid in Australia focuses on these issues: direct vs. indirect payment to students; inequality in living allowances given to secondary and postsecondary students; and distribution of expense allowances by state government and living allowances by the Commonwealth. (MSE)

Baby Steps.

ERIC Educational Resources Information Center

Jones, Wendell H.

1997-01-01

A harried school counselor describes a tangled web of domestic discord and agency miscoordination (complicated by an unintelligible restraining order and a birth certificate mix-up) that try his patience and leave a young girl bereft of family. Dakota Stages's gutsiness and resiliency impress this counselor immensely. (MLH)

Vertical leadership in highly complex and unpredictable health systems.

PubMed

Till, Alex; Dutta, Nina; McKimm, Judy

2016-08-02

This article explores how the concept of vertical leadership development might help health organizations cope with and thrive within highly complex and unpredictable health systems, looking at concepts of VUCA (volatility, uncertainty, complexity and ambiguity) and RUPT (rapid, unpredictable, paradoxical and tangled).

Global / globalizing cities.

PubMed

Yeoh, B S

1999-01-01

Along with the rise in research on globalization, the concept of globalization has become a subject to a more critical scrutiny. While majority agree that it represents a serious challenge to the state-centrist assumptions of most previous social science, doubts about its newness, inevitability and epoch-making qualities are also being raised. Others argue that the globalization literature neglects issues of social regulation by the nation-state, while some critics view it as a discourse drawn upon to legitimize particular political and economic agendas. Debates focus on metropolitan manifestations and impacts. Moving from this background, the paper presents three sociospatial urban configurations that have emerged in the literature. Alongside attempts at identifying globalizing cities and transnational urban networks as new theoretical subjects, another significant vein in the literature focuses on the complex forces of globalization and the production of new urban spaces in these cities. In addition, economic conceptions of globalization is now being pushed beyond adding sociocultural or sociopolitical dimensions and argue instead for the need to theorize globalization as a discursive formation. The global city as a discursive category conjures up imaginary concepts of high modernity, megadevelopment, 21st century urbanity. However, it is noted that the way forward is to focus on the distinctive ways in which urban actors engage in specific processes of economic and social reflexivity. There exists an urgent task for theorizations of the global city, which weave together historical, economic, cultural, sociopolitical and discursive dimensions.

New Sexism in Couple Therapy: A Discursive Analysis.

PubMed

Sutherland, Olga; LaMarre, Andrea; Rice, Carla; Hardt, Laura; Le Couteur, Amanda

2017-09-01

The persistence of gender inequality in postindustrial societies is puzzling in light of a plethora of changes that destabilize it, including shifts in economy, legislation, and the proliferation of feminist politics. In family relations, such persistence manifests as a disconnect between couples aspiring to be more egalitarian yet continuing to enact traditional gender roles and hierarchies. There is an emerging consensus that gender inequality persists because of people's continued reliance on sexist ideology or gendered assumptions that constitute women as innately distinct from and inferior to men. Sexist ideology changes its form to accommodate to changing socio-economic conditions. Contemporary forms of sexism are old ways of legitimizing male power articulated in new and creative ways, often by incorporating feminist arguments. To effectively recognize and address "new sexism," scholars and practitioners require new, innovative research frameworks. Our objective in writing this article is two-fold. First, we seek to advance discursive (i.e., focused on language in use) approaches to the study of sexism. Second, we present the results of a discursive analysis of "new" sexist discourse in the context of couple therapy. The study provides preliminary evidence that, despite endorsing egalitarian norms, couples studied continue to rely on gender binaries and remain entrenched in old-fashioned patterns of gender inequality. Implications of these results for the practice of couple therapy and for future research are discussed. © 2017 Family Process Institute.

Constructing the collective unconscious.

PubMed

Gullatz, Stefan

2010-11-01

Innovative attempts at collating Jungian analytical psychology with a range of 'post-modern' theories have yielded significant results. This paper adopts an alternative strategy: a Lacanian vantage point on Jungian theory that eschews an attempt at reconciling Jung with post-structuralism. A focused Lacanian gaze on Jung will establish an irreducible tension between Jung's view of archetypes as factors immanent to the psyche and a Lacanian critique that lays bare the contingent structures and mechanisms of their constitution, unveiling the supposed archetypes'a posteriori production through the efficacy of a discursive field. Theories of ideology developed in the wake of Lacan provide a powerful methodological tool allowing to bring this distinction into focus. An assembly of Lacan's fragmentary accounts of Jung will be supplemented with an approach to Jungian theory via Žižek's Lacan-oriented theory of the signifying mechanism underpinning 'ideology'. Accordingly, the Jungian archetype of the self, which is considered in some depth, can begin to be seen in a new light, namely as a 'master signifier', not only of Jung's academic edifice, but also -and initially-of the discursive strategies that establish his own subjectivity. A discussion of Jung's approach to mythology reveals how the 'quilting point' of his discourse comes to be coupled with a correlate in the Real, a non-discursive 'sublime object' conferring upon archetypes their fascinating aura. © 2010, The Society of Analytical Psychology.

[The concept of identity in relation to motherhood in the discourse of teenagers who attend a pregnancy from a linguistic and psychoanalytical perspective].

PubMed

Pardo, María L

2013-01-01

My aim in this paper is to briefly discuss the notion of identity and how can unify the Psychoanalytical concept with the discursive, in order to carry out multidisciplinary research on this topic. This work is based on life stories collected in the Hospital Larcade, from 2008 to 2011, from teenagers who attend a pregnancy. Through the linguistic analysis of the guarantees, following the model of Toulmin (17), as it has been redefined by Pardo (14) and Molina (12), I intend to give an account of the discursive and psychological bases of what will then form an identity for these young women on maternity. They live in extreme poverty in the Buenos Aires suburbs and are combined with a large dose of family violence that links their identities as mothers to the image (or identities of the other) who have over their own mothers, parents, couples in these contexts of violence. These data are also confronted with domestic violence cases that appear in the media and how they are dealt with discursively at these. Thus realizes the contradictions imposed the cultural identity of a group (the viewers or readers of means, which are a large part of society) against the experience of violence of these mothers. This research has as theoretical framework the Critical Discourse Analysis and the methodology is qualitative.

Entrapment of Victims of Spousal Abuse in Ghana: A Discursive Analysis of Family Identity and Agency of Battered Women.

PubMed

Adjei, Stephen Baffour

2015-06-02

Drawing on discursive psychology and positioning theory, this study explores the influence of cultural and familial value orientations on battered women's identity, agency, and decision to leave or stay in abusive conjugal relationship in Ghana. Two semi-structured focus group discussions and four in-depth personal interviews were conducted with 16 victims of husband-to-wife abuse from rural and urban Ghana. The findings indicate that entrapment of victims of spousal abuse in Ghana reflects their social embeddedness and that battered women's identities and agency are expressed in the context of familial and cultural value orientations. The primacy of family identity and victims' apparent implicit moral obligation to preserve the social image of their extended family influence their entrapment. Participants' discursive accounts further suggest that stay or leave decisions of battered women in Ghana reflect a joint product of negotiated agency between victims and their extended family. It is thus argued that the agency of battered women in Ghana is not constituted by individual psychological states or motives, but instead, viewed as a property of victims who exercise it in a given relational context, and partly constituted by familial relationships and identities. The study suggests that intervention initiatives in Ghana should focus on the phenomenon of conjugal violence beyond immediate victims to include families and the larger communities in which victims are embedded. © The Author(s) 2015.

Ultrastructural characteristics of tau filaments in tauopathies: immuno-electron microscopic demonstration of tau filaments in tauopathies.

PubMed

Arima, Kunimasa

2006-10-01

The microtubule-associated protein tau aggregates into filaments in the form of neurofibrillary tangles, neuropil threads and argyrophilic grains in neurons, in the form of variable astrocytic tangles in astrocytes and in the form of coiled bodies and argyrophilic threads in oligodendrocytes. These tau filaments may be classified into two types, straight filaments or tubules with 9-18 nm diameters and "twisted ribbons" composed of two parallel aligned components. In the same disease, the fine structure of tau filaments in glial cells roughly resembles that in neurons. In sporadic tauopathies, individual tau filaments show characteristic sizes, shapes and arrangements, and therefore contribute to neuropathologic differential diagnosis. In frontotemporal dementias caused by tau gene mutations, variable filamentous profiles were observed in association with mutation sites and insoluble tau isoforms, including straight filaments or tubules, paired helical filament-like filaments, and twisted ribbons. Pre-embedding immunoelectron microscopic studies were carried out using anti-3-repeat tau and anti-4-repeat tau specific antibodies, RD3 and RD4. Straight tubules in neuronal and astrocytic Pick bodies were immunolabeled by the anti-3-repeat tau antibody. The anti-4-repeat tau antibody recognized abnormal tubules comprising neurofibrillary tangles, coiled bodies and argyrophilic threads in progressive supranuclear palsy (PSP) and corticobasal degeneration. In the pre-embedding immunoelectron microscopic study using the phosphorylated tau AT8 antibody, tuft-shaped astrocytes of PSP were found to be composed of bundles of abnormal tubules in processes and perikarya of protoplasmic astrocytes. In this study, the 3-repeat tau or 4-repeat tau epitope was detected in situ at the ultrastructural level in abnormal tubules in representative pathological lesions in Pick's disease, PSP and corticobasal degeneration.

Age- and disease-dependent increase of the mitophagy marker phospho-ubiquitin in normal aging and Lewy body disease.

PubMed

Hou, Xu; Fiesel, Fabienne C; Truban, Dominika; Castanedes Casey, Monica; Lin, Wen-Lang; Soto, Alexandra I; Tacik, Pawel; Rousseau, Linda G; Diehl, Nancy N; Heckman, Michael G; Lorenzo-Betancor, Oswaldo; Ferrer, Isidre; Arbelo, José M; Steele, John C; Farrer, Matthew J; Cornejo-Olivas, Mario; Torres, Luis; Mata, Ignacio F; Graff-Radford, Neill R; Wszolek, Zbigniew K; Ross, Owen A; Murray, Melissa E; Dickson, Dennis W; Springer, Wolfdieter

2018-06-27

Although exact causes of Parkinson disease (PD) remain enigmatic, mitochondrial dysfunction is increasingly appreciated as a key determinant of dopaminergic neuron susceptibility in both familial and sporadic PD. Two genes associated with recessive, early-onset PD encode the ubiquitin (Ub) kinase PINK1 and the E3 Ub ligase PRKN/PARK2/Parkin, which together orchestrate a protective mitochondrial quality control (mitoQC) pathway. Upon stress, both enzymes cooperatively identify and decorate damaged mitochondria with phosphorylated poly-Ub (p-S65-Ub) chains. This specific label is subsequently recognized by autophagy receptors that further facilitate mitochondrial degradation in lysosomes (mitophagy). Here, we analyzed human post-mortem brain specimens and identified distinct pools of p-S65-Ub-positive structures that partially colocalized with markers of mitochondria, autophagy, lysosomes and/or granulovacuolar degeneration bodies. We further quantified levels and distribution of the 'mitophagy tag' in 2 large cohorts of brain samples from normal aging and Lewy body disease (LBD) cases using unbiased digital pathology. Somatic p-S65-Ub structures independently increased with age and disease in distinct brain regions and enhanced levels in LBD brain were age- and Braak tangle stage-dependent. Additionally, we observed significant correlations of p-S65-Ub with LBs and neurofibrillary tangle levels in disease. The degree of co-existing p-S65-Ub signals and pathological PD hallmarks increased in the pre-mature stage, but decreased in the late stage of LB or tangle aggregation. Altogether, our study provides further evidence for a potential pathogenic overlap among different forms of PD and suggests that p-S65-Ub can serve as a biomarker for mitochondrial damage in aging and disease.

Cerebral amyloid-beta protein accumulation with aging in cotton-top tamarins: a model of early Alzheimer's disease?

PubMed

Lemere, Cynthia A; Oh, Jiwon; Stanish, Heather A; Peng, Ying; Pepivani, Imelda; Fagan, Anne M; Yamaguchi, Haruyasu; Westmoreland, Susan V; Mansfield, Keith G

2008-04-01

Alzheimer's disease (AD) is the most common progressive form of dementia in the elderly. Two major neuropathological hallmarks of AD include cerebral deposition of amyloid-beta protein (Abeta) into plaques and blood vessels, and the presence of neurofibrillary tangles in brain. In addition, activated microglia and reactive astrocytes are often associated with plaques and tangles. Numerous other proteins are associated with plaques in human AD brain, including Apo E and ubiquitin. The amyloid precursor protein and its shorter fragment, Abeta, are homologous between humans and non-human primates. Cerebral Abeta deposition has been reported previously for rhesus monkeys, vervets, squirrel monkeys, marmosets, lemurs, cynomologous monkeys, chimpanzees, and orangutans. Here we report, for the first time, age-related neuropathological changes in cotton-top tamarins (CTT, Saguinus oedipus), an endangered non-human primate native to the rainforests of Colombia and Costa Rica. Typical lifespan is 13-14 years of age in the wild and 15-20+ years in captivity. We performed detailed immunohistochemical analyses of Abeta deposition and associated pathogenesis in archived brain sections from 36 tamarins ranging in age from 6-21 years. Abeta plaque deposition was observed in 16 of the 20 oldest tamarins (>12 years). Plaques contained mainly Abeta42, and in the oldest animals, were associated with reactive astrocytes, activated microglia, Apo E, and ubiquitin-positive dystrophic neurites, similar to human plaques. Vascular Abeta was detected in 14 of the 20 aged tamarins; Abeta42 preceded Abeta40 deposition. Phospho-tau labeled dystrophic neurites and tangles, typically present in human AD, were absent in the tamarins. In conclusion, tamarins may represent a model of early AD pathology.

Neuropathologic features associated with Alzheimer disease diagnosis

PubMed Central

Grinberg, L.T.; Miller, B.; Kawas, C.; Yaffe, K.

2011-01-01

Objective: To examine whether the association between clinical Alzheimer disease (AD) diagnosis and neuropathology and the precision by which neuropathology differentiates people with clinical AD from those with normal cognition varies by age. Methods: We conducted a cross-sectional analysis of 2,014 older adults (≥70 years at death) from the National Alzheimer's Coordinating Center database with clinical diagnosis of normal cognition (made ≤1 year before death, n = 419) or AD (at ≥65 years, n = 1,595) and a postmortem neuropathologic examination evaluating AD pathology (neurofibrillary tangles, neuritic plaques) and non-AD pathology (diffuse plaques, amyloid angiopathy, Lewy bodies, macrovascular disease, microvascular disease). We used adjusted logistic regression to analyze the relationship between clinical AD diagnosis and neuropathologic features, area under the receiver operating characteristic curve (c statistic) to evaluate how precisely neuropathology differentiates between cognitive diagnoses, and an interaction to identify effect modification by age group. Results: In a model controlling for coexisting neuropathologic features, the relationship between clinical AD diagnosis and neurofibrillary tangles was significantly weaker with increasing age (p < 0.001 for interaction). The aggregate of all neuropathologic features more strongly differentiated people with clinical AD from those without in younger age groups (70–74 years: c statistic, 95% confidence interval: 0.93, 0.89–0.96; 75–84 years: 0.95, 0.87–0.95; ≥85 years: 0.83, 0.80–0.87). Non-AD pathology significantly improved precision of differentiation across all age groups (p < 0.004). Conclusion: Clinical AD diagnosis was more weakly associated with neurofibrillary tangles among the oldest old compared to younger age groups, possibly due to less accurate clinical diagnosis, better neurocompensation, or unaccounted pathology among the oldest old. PMID:22031532

Regional Geochemical Results from Analyses of Stream-Water, Stream-Sediment, Soil, Soil-Water, Bedrock, and Vegetation Samples, Tangle Lakes District, Alaska

USGS Publications Warehouse

Wang, Bronwen; Gough, L.P.; Wanty, R.B.; Lee, G.K.; Vohden, James; O'Neill, J. M.; Kerin, L.J.

2008-01-01

We report chemical analyses of stream-water, stream-sediment, soil, soil-water, bedrock, and vegetation samples collected from the headwaters of the Delta River (Tangle Lakes District, Mount Hayes 1:250,000-scale quadrangle) in east-central Alaska for the period June 20-25, 2006. Additionally, we present mineralogic analyses of stream sediment, concentrated by panning. The study area includes the southwestward extent of the Bureau of Land Management (BLM) Delta River Mining District (Bittenbender and others, 2007), including parts of the Delta River Archeological District, and encompasses an area of about 500 km2(approximately bordered by the Denali Highway to the south, near Round Tangle Lake, northward to the foothills of the Alaska Range (fig. 1). The primary focus of this study was the chemical characterization of native materials, especially surface-water and sediment samples, of first-order streams from the headwaters of the Delta River. The impetus for this work was the need, expressed by the Alaska Department of Natural Resources (ADNR), for an inventory of geochemical and hydrogeochemical baseline information about the Delta River Mining District. This information is needed because of a major upturn in exploration, drilling, and general mineral-resources assessments in the region since the late 1990s. Currently, the study area, called the 'MAN Project' area is being explored by Pure Nickel, Inc. (http://www.purenickel.com/s/MAN_Alaska.asp), and includes both Cu-Au-Ag and Ni-Cu-PGE (Pt-Pd-Au-Ag) mining claims. Geochemical data on surface-water, stream-sediment, soil, soil-water, grayleaf willow (Salix glauca L.), and limited bedrock samples are provided along with the analytical methodologies used and panned-concentrate mineralogy. We are releasing the data at this time with only minimal interpretation.

Evaluation of 8-week body weight control program including sea tangle (Laminaria japonica) supplementation in Korean female college students

PubMed Central

You, Jeong Soon; Sung, Min Jung

2009-01-01

This study was conducted to evaluate the effects of a body weight control program with supplementation of sea tangle (20 g/day) on 22 female college students. The contents of the program for 8 weeks contained diet therapy, exercise and behavioral modification through nutrition education. Body composition, dietary habit scores, serum lipid profiles, daily nutrient intakes and the quality of life were assessed at the beginning and at the end of the program. Average age of subjects and height were 20.8 years and 161.9 cm, respectively. After 8 weeks, there were significant reductions in body weight, body fat mass, percent body fat, waist-hip ratio and BMI. The dietary habit score such as a balanced diet, regularity of mealtime, overeating, eating while watching TV or using the computer and eating salty food were increased significantly. Serum lipid levels such as total cholesterol level, LDL-cholesterol level and triglyceride level were decreased but not significantly. There were decreases in intake of energy, protein and fat and increases in intakes of dietary fiber, folic acid, calcium and potassium from the beginning to the end of the program. There were significant improvements on subcomponents of quality of life; physical functioning, general-health and vitality. The limitation of this study was the fact that there was no control group, but an overall evaluation suggests the 8-week body weight control program consisting of diet therapy, exercise and behavioral modification with supplementation of sea tangle would be helpful to improve the body composition, dietary habits, daily nutrient intakes and quality of life in Korean female college students. PMID:20098584

IS THE SMALL-SCALE MAGNETIC FIELD CORRELATED WITH THE DYNAMO CYCLE?

DOE Office of Scientific and Technical Information (OSTI.GOV)

Karak, Bidya Binay; Brandenburg, Axel, E-mail: bbkarak@nordita.org

2016-01-01

The small-scale magnetic field is ubiquitous at the solar surface—even at high latitudes. From observations we know that this field is uncorrelated (or perhaps even weakly anticorrelated) with the global sunspot cycle. Our aim is to explore the origin, and particularly the cycle dependence, of such a phenomenon using three-dimensional dynamo simulations. We adopt a simple model of a turbulent dynamo in a shearing box driven by helically forced turbulence. Depending on the dynamo parameters, large-scale (global) and small-scale (local) dynamos can be excited independently in this model. Based on simulations in different parameter regimes, we find that, when onlymore » the large-scale dynamo is operating in the system, the small-scale magnetic field generated through shredding and tangling of the large-scale magnetic field is positively correlated with the global magnetic cycle. However, when both dynamos are operating, the small-scale field is produced from both the small-scale dynamo and the tangling of the large-scale field. In this situation, when the large-scale field is weaker than the equipartition value of the turbulence, the small-scale field is almost uncorrelated with the large-scale magnetic cycle. On the other hand, when the large-scale field is stronger than the equipartition value, we observe an anticorrelation between the small-scale field and the large-scale magnetic cycle. This anticorrelation can be interpreted as a suppression of the small-scale dynamo. Based on our studies we conclude that the observed small-scale magnetic field in the Sun is generated by the combined mechanisms of a small-scale dynamo and tangling of the large-scale field.« less

Re-rupture rate of primarily repaired distal biceps tendon injuries.

PubMed

Hinchey, John W; Aronowitz, Jessica G; Sanchez-Sotelo, Joaquin; Morrey, Bernard F

2014-06-01

Distal biceps tendon rupture is a common injury, and primary repair results in excellent return of function and strength. Complications resulting from distal biceps tendon repairs are well reported, but the incidence of re-ruptures has never been investigated. A search of the Mayo Clinic's Medical/Surgical Index was performed, and all distal biceps tendon repairs from January 1981 through May 2009 were identified. All patients who completed 12 months or more of follow-up were included. All charts were reviewed and patients contacted as necessary to identify a re-rupture. We also investigated the situation causing the re-rupture. We identified a total of 190 distal biceps tendon ruptures that underwent repair and met our inclusion and exclusion criteria. Of the 190 repairs, 172 (90.5%) were performed by the Mayo modification of the Boyd-Anderson 2-incision technique. Bilateral ruptures occurred in 13 patients (7.3%). Six primary ruptures (3.2%) occurred in women, 4 of the 6 being partial ruptures. Partial ruptures were found to be statistically more common than complete ruptures in women (P = .05). We identified 3 re-ruptures (1.5%), all occurring within 3 weeks of the index surgery. The re-rupture rate after primary repair of the distal biceps tendon is low at 1.5% and occurs within 3 weeks of index repair. This appears to be due to patient compliance and excessive force placed on repairs. We also found the incidence of women who sustain a distal biceps tendon tear to be 3.2%, with partial tears being statistically more common than complete ruptures. Level IV, case series, treatment study Copyright © 2014 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Mosby, Inc. All rights reserved.

Kinematic Rupture Process of the 2015 Gorkha (Nepal) Earthquake Sequence from Joint Inversion of Teleseismic, hr-GPS, Strong-Ground Motion, InSAR interferograms and pixel offsets

NASA Astrophysics Data System (ADS)

Yue, H.; Simons, M.; Jiang, J.; Fielding, E. J.; Owen, S. E.; Moore, A. W.; Riel, B. V.; Polet, J.; Duputel, Z.; Samsonov, S. V.; Avouac, J. P.

2015-12-01

The April 2015 Gorkha, Nepal (Mw 7.8) earthquake ruptured the front of Himalaya thrust belt, causing more than 9,000 fatalities. 17 days after the main event, a large aftershock (Mw 7.2) ruptured to down-dip and east of the main rupture area. To investigate the kinematic rupture process of this earthquake sequence, we explored linear and non-linear inversion techniques using a variety of datasets including teleseismic, high rate and conventional GPS, InSAR interferograms and pixel-offsets. InSAR interferograms from ALOS-2, RADARSAT-2 and Sentinel-1a satellites are used in the joint inversion. The main event is characterized by unilateral rupture extending along strike approximately 70 km to the southeast and 40 km along dip direction. The rupture velocity is well resolved to be lie between 2.8 and 3.0 km/s, which is consistent with back-projection results. An emergent initial phase is observed in teleseismic body wave records, which is consistent with a narrow area of rupture initiation near the hypocenter. The rupture mode of the main event is pulse like. The aftershock ruptured down-dip to the northeast of the main event rupture area. The aftershock rupture area is compact and contained within 40 km of its hypocenter. In contrast to the main event, teleseismic body wave records of the aftershock suggest an abrupt initial phase, which is consistent with a crack like rupture mode. The locations of most of the aftershocks (small and large) surround the rupture area of the main shock with little, if any, spatial overlap.

Influence of morphology and hemodynamic factors on rupture of multiple intracranial aneurysms: matched-pairs of ruptured-unruptured aneurysms located unilaterally on the anterior circulation.

PubMed

Zhang, Ying; Yang, Xinjian; Wang, Yang; Liu, Jian; Li, Chuanhui; Jing, Linkai; Wang, Shengzhang; Li, Haiyun

2014-12-31

The authors evaluated the impact of morphological and hemodynamic factors on the rupture of matched-pairs of ruptured-unruptured intracranial aneurysms on one patient's ipsilateral anterior circulation with 3D reconstruction model and computational fluid dynamic method simulation. 20 patients with intracranial aneurysms pairs on the same-side of anterior circulation but with different rupture status were retrospectively collected. Each pair was divided into ruptured-unruptured group. Patient-specific models based on their 3D-DSA images were constructed and analyzed. The relative locations, morphologic and hemodynamic factors of these two groups were compared. There was no significant difference in the relative bleeding location. The morphological factors analysis found that the ruptured aneurysms more often had irregular shape and had significantly higher maximum height and aspect ratio. The hemodynamic factors analysis found lower minimum wall shear stress (WSSmin) and more low-wall shear stress-area (LSA) in the ruptured aneurysms than that of the unruptured ones. The ruptured aneurysms more often had WSSmin on the dome. Intracranial aneurysms pairs with different rupture status on unilateral side of anterior circulation may be a good disease model to investigate possible characteristics linked to rupture independent of patient characteristics. Irregular shape, larger size, higher aspect ratio, lower WSSmin and more LSA may indicate a higher risk for their rupture.

Characterize kinematic rupture history of large earthquakes with Multiple Haskell sources

NASA Astrophysics Data System (ADS)

Jia, Z.; Zhan, Z.

2017-12-01

Earthquakes are often regarded as continuous rupture along a single fault, but the occurrence of complex large events involving multiple faults and dynamic triggering challenges this view. Such rupture complexities cause difficulties in existing finite fault inversion algorithms, because they rely on specific parameterizations and regularizations to obtain physically meaningful solutions. Furthermore, it is difficult to assess reliability and uncertainty of obtained rupture models. Here we develop a Multi-Haskell Source (MHS) method to estimate rupture process of large earthquakes as a series of sub-events of varying location, timing and directivity. Each sub-event is characterized by a Haskell rupture model with uniform dislocation and constant unilateral rupture velocity. This flexible yet simple source parameterization allows us to constrain first-order rupture complexity of large earthquakes robustly. Additionally, relatively few parameters in the inverse problem yields improved uncertainty analysis based on Markov chain Monte Carlo sampling in a Bayesian framework. Synthetic tests and application of MHS method on real earthquakes show that our method can capture major features of large earthquake rupture process, and provide information for more detailed rupture history analysis.

Geologic Inheritance and Earthquake Rupture Processes: The 1905 M ≥ 8 Tsetserleg-Bulnay Strike-Slip Earthquake Sequence, Mongolia

NASA Astrophysics Data System (ADS)

Choi, Jin-Hyuck; Klinger, Yann; Ferry, Matthieu; Ritz, Jean-François; Kurtz, Robin; Rizza, Magali; Bollinger, Laurent; Davaasambuu, Battogtokh; Tsend-Ayush, Nyambayar; Demberel, Sodnomsambuu

2018-02-01

In 1905, 14 days apart, two M 8 continental strike-slip earthquakes, the Tsetserleg and Bulnay earthquakes, occurred on the Bulnay fault system, in Mongolia. Together, they ruptured four individual faults, with a total length of 676 km. Using submetric optical satellite images "Pleiades" with ground resolution of 0.5 m, complemented by field observation, we mapped in detail the entire surface rupture associated with this earthquake sequence. Surface rupture along the main Bulnay fault is 388 km in length, striking nearly E-W. The rupture is formed by a series of fault segments that are 29 km long on average, separated by geometric discontinuities. Although there is a difference of about 2 m in the average slip between the western and eastern parts of the Bulnay rupture, along-fault slip variations are overall limited, resulting in a smooth slip distribution, except for local slip deficit at segment boundaries. We show that damage, including short branches and secondary faulting, associated with the rupture propagation, occurred significantly more often along the western part of the Bulnay rupture, while the eastern part of the rupture appears more localized and thus possibly structurally simpler. Eventually, the difference of slip between the western and eastern parts of the rupture is attributed to this difference of rupture localization, associated at first order with a lateral change in the local geology. Damage associated to rupture branching appears to be located asymmetrically along the extensional side of the strike-slip rupture and shows a strong dependence on structural geologic inheritance.

Rupture rate and patterns of shell failure with the McGhan Style 153 double-lumen breast implant.

PubMed

Neaman, Keith C; Albert, Mark; Hammond, Dennis C

2011-01-01

In 2005, the McGhan Style 153 double-lumen breast implant was removed from the market secondary to a higher rupture rate when contrasted with other implants in the Core Study group. The high rupture rate was attributed to the development of a posterior tear in the shell where the inner implant is bonded to the posterior wall of the device. The purpose of this study was to report the existing rupture rate and describe the apparent mechanism of failure in the Style 153 double-lumen breast implant. Ninety-seven patients (157 implants) who received the McGhan Style 153 double-lumen breast implant by the senior author were reviewed. Intraoperative observations and photographic images of ruptured implants were reviewed and characterized based on severity and location of implant rupture. With a mean length of follow-up of greater than 6 years (82 months), the rupture rate was 19.1 percent per implant. Physical examination (60 percent) was the most common method of rupture detection. Ruptures tended to occur in the marginal aspect (63 percent) of the implant. Only three ruptures occurred secondary to a disruption of the inner bladder from the posterior portion of the implant. The rupture rate of the Style 153 double-lumen breast implant is higher than previously thought, with a rate of 19.1 percent. A majority of ruptures occurred in the peripheral aspects of the implant. It is postulated that these ruptures were likely secondary to fold flaws that led to failure of the implant shell.

Multiple tendon ruptures of unknown etiology.

PubMed

Axibal, Derek P; Anderson, John G

2013-10-01

Tendon ruptures are common findings in foot and ankle practice. The etiology of tendon ruptures tends to be multifactorial-usually due to a combination of trauma, effects of systemic diseases, adverse effects of medications, and obesity. We present an unusual case of right Achilles tendinitis, left Achilles tendon rupture, bilateral peroneus longus tendon rupture, and left peroneus brevis tendon rupture of unknown etiology. This case report highlights the need for research for other possible, lesser known etiologies of tendon pathology. Therapeutic, Level IV, Case Study.

Gendering attention deficit hyperactivity disorder: a discursive analysis of UK newspaper stories.

PubMed

Horton-Salway, Mary

2013-08-01

Discursive psychology is used to study the gendering of attention deficit hyperactivity disorder in UK national newspapers in the period of 2009-2011. The analysis examines how gendering is embedded in causal attributions and identity constructions. Attention deficit hyperactivity disorder is portrayed as a predominantly male phenomenon with representations of attention deficit hyperactivity disorder being gendered through extreme stories about victims, villains or heroes that depict boys and men as marginalised, exceptional or dangerous. There is also a focus on mothers as the spokespersons and caretakers for parenting and family health while fathers are rendered more invisible. This contributes to our understanding of how attention deficit hyperactivity disorder is constructed in the media using a range of gendered representations that draw on cultural stereotypes familiar in Western societies.

Framing curriculum discursively: theoretical perspectives on the experience of VCE physics

NASA Astrophysics Data System (ADS)

Hart, Christina

2002-10-01

The process of developing prescribed curricula has been subject to little empirical investigation, and there have been few attempts to develop theoretical frameworks for understanding the shape and content of particular subjects. This paper presents an account of the author's experience of developing a new course for school physics in the State of Victoria, Australia, at the end of the 1980s. The course was to represent a significant departure from traditional physics courses, and was intended to broaden participation and improve the quality of student learning. In the event the new course turned out to be very similar to traditional courses in Physics. The paper explores the reasons for this outcome. Some powerful discursive mechanisms are identified and some implications of post-structuralism for the theoretical understanding of curriculum are discussed.

Expanding hegemonic masculinity: the use of irony in young men's stories about romantic experiences.

PubMed

Korobov, Neill

2009-12-01

This study examines the use of irony in young men's stories about romantic and sexual experiences. Because romantic experiences are central in the constitution of a heterosexual self, and because they are increasingly formulated in relation to traditional masculine norms and the simultaneous avowal and disavowal of effeminacy, they reveal an oscillation between complicity and resistance to hegemonic masculine norms. This oscillation is explored in stories about promiscuity, seduction, and vulnerability. Critical discursive analyses reveal how young men discursively pivot between complicity and resistance to traditional masculine norms, how this oscillation functions in the accomplishment of their romantic identities, how a sense of conventional masculinity is reclaimed, and what these processes reveal about the shifting nature of hegemonic masculinity in contemporary culture.

Heroin Use Is Associated with Ruptured Saccular Aneurysms.

PubMed

Can, Anil; Castro, Victor M; Ozdemir, Yildirim H; Dagen, Sarajune; Dligach, Dmitriy; Finan, Sean; Yu, Sheng; Gainer, Vivian; Shadick, Nancy A; Savova, Guergana; Murphy, Shawn; Cai, Tianxi; Weiss, Scott T; Du, Rose

2017-11-04

While cocaine use is thought to be associated with aneurysmal rupture, it is not known whether heroin use increases the risk of rupture in patients with non-mycotic saccular aneurysms. Our goal was to investigate the association between heroin and cocaine use and the rupture of saccular non-mycotic aneurysms. The medical records of 4701 patients with 6411 intracranial aneurysms, including 1201 prospective patients, diagnosed at the Brigham and Women's Hospital and Massachusetts General Hospital between 1990 and 2016 were reviewed and analyzed. Patients were separated into ruptured and non-ruptured groups. Univariable and multivariable logistic regression analyses were performed to determine the association between heroin, cocaine, and methadone use and the presence of ruptured intracranial aneurysms. In multivariable analysis, current heroin use was significantly associated with rupture status (OR 3.23, 95% CI 1.33-7.83) whereas former heroin use (with and without methadone replacement therapy), and current and former cocaine use were not significantly associated with intracranial aneurysm rupture. In the present study, heroin rather than cocaine use is significantly associated with intracranial aneurysm rupture in patients with non-mycotic saccular cerebral aneurysms, emphasizing the possible role of heroin in the pathophysiology of aneurysm rupture and the importance of heroin cessation in patients harboring unruptured intracranial aneurysms.

Fault zones ruptured during the early 2014 Cephalonia Island (Ionian Sea, Western Greece) earthquakes (January 26 and February 3, Mw 6.0) based on the associated co-seismic surface ruptures

NASA Astrophysics Data System (ADS)

Lekkas, Efthymios L.; Mavroulis, Spyridon D.

2016-01-01

The early 2014 Cephalonia Island (Ionian Sea, Western Greece) earthquake sequence comprised two main shocks with almost the same magnitude (moment magnitude (Mw) 6.0) occurring successively within a short time (January 26 and February 3) and space (Paliki peninsula in Western Cephalonia) interval. Εach earthquake was induced by the rupture of a different pre-existing onshore active fault zone and produced different co-seismic surface rupture zones. Co-seismic surface rupture structures were predominantly strike-slip-related structures including V-shaped conjugate surface ruptures, dextral and sinistral strike-slip surface ruptures, restraining and releasing bends, Riedel structures ( R, R', P, T), small-scale bookshelf faulting, and flower structures. An extensional component was present across surface rupture zones resulting in ground openings (sinkholes), small-scale grabens, and co-seismic dip-slip (normal) displacements. A compressional component was also present across surface rupture zones resulting in co-seismic dip-slip (reverse) displacements. From the comparison of our field geological observations with already published surface deformation measurements by DInSAR Interferometry, it is concluded that there is a strong correlation among the surface rupture zones, the ruptured active fault zones, and the detected displacement discontinuities in Paliki peninsula.

Sellers holds up a bundle of tangled audio cables during STS-121 / Expedition 13 joint operations

NASA Image and Video Library

2006-07-15

S121-E-07791 (15 July 2006) --- Astronaut Piers J. Sellers, STS-121 mission specialist, works with cables on the middeck of Space Shuttle Discovery as the shuttle crew prepares to undock from the International Space Station.

7 CFR 29.6027 - Nested.

Code of Federal Regulations, 2012 CFR

2012-01-01

... INSPECTION Standards Definitions § 29.6027 Nested. Any tobacco which has been loaded, packed, or arranged to conceal foreign matter or tobacco of inferior grade, quality, or condition. Nested includes any lot of tobacco which contains foreign matter or damaged, injured, tangled, or other inferior tobacco, any of...

7 CFR 29.6027 - Nested.

Code of Federal Regulations, 2013 CFR

2013-01-01

... INSPECTION Standards Definitions § 29.6027 Nested. Any tobacco which has been loaded, packed, or arranged to conceal foreign matter or tobacco of inferior grade, quality, or condition. Nested includes any lot of tobacco which contains foreign matter or damaged, injured, tangled, or other inferior tobacco, any of...

7 CFR 29.6027 - Nested.

Code of Federal Regulations, 2014 CFR

2014-01-01

... INSPECTION Standards Definitions § 29.6027 Nested. Any tobacco which has been loaded, packed, or arranged to conceal foreign matter or tobacco of inferior grade, quality, or condition. Nested includes any lot of tobacco which contains foreign matter or damaged, injured, tangled, or other inferior tobacco, any of...

7 CFR 29.6027 - Nested.

Code of Federal Regulations, 2011 CFR

2011-01-01

... INSPECTION Standards Definitions § 29.6027 Nested. Any tobacco which has been loaded, packed, or arranged to conceal foreign matter or tobacco of inferior grade, quality, or condition. Nested includes any lot of tobacco which contains foreign matter or damaged, injured, tangled, or other inferior tobacco, any of...

T-Shirt Tangle.

ERIC Educational Resources Information Center

Clark, Wilma

1986-01-01

Describes an exercise in which students cut out T-shirt drawings, sort the T-shirts into groups, and "write" a classification essay by pasting the T-shirts on sheet of paper. The T-shirts in each group become the examples used in one body paragraph of the classification essay. (HTH)

7 CFR 30.8 - Scrap.

Code of Federal Regulations, 2013 CFR

2013-01-01

... AND STANDARDS Classification of Leaf Tobacco Covering Classes, Types and Groups of Grades § 30.8 Scrap. A byproduct from handling leaf tobacco in both the unstemmed and stemmed forms, consisting of loose and tangled portions of tobacco leaves, floor sweepings, and all other tobacco materials (except stems...

7 CFR 30.8 - Scrap.

Code of Federal Regulations, 2011 CFR

2011-01-01

... AND STANDARDS Classification of Leaf Tobacco Covering Classes, Types and Groups of Grades § 30.8 Scrap. A byproduct from handling leaf tobacco in both the unstemmed and stemmed forms, consisting of loose and tangled portions of tobacco leaves, floor sweepings, and all other tobacco materials (except stems...

7 CFR 30.8 - Scrap.

Code of Federal Regulations, 2010 CFR

2010-01-01

... AND STANDARDS Classification of Leaf Tobacco Covering Classes, Types and Groups of Grades § 30.8 Scrap. A byproduct from handling leaf tobacco in both the unstemmed and stemmed forms, consisting of loose and tangled portions of tobacco leaves, floor sweepings, and all other tobacco materials (except stems...

7 CFR 30.8 - Scrap.

Code of Federal Regulations, 2012 CFR

2012-01-01

... AND STANDARDS Classification of Leaf Tobacco Covering Classes, Types and Groups of Grades § 30.8 Scrap. A byproduct from handling leaf tobacco in both the unstemmed and stemmed forms, consisting of loose and tangled portions of tobacco leaves, floor sweepings, and all other tobacco materials (except stems...

7 CFR 30.8 - Scrap.

Code of Federal Regulations, 2014 CFR

2014-01-01

... AND STANDARDS Classification of Leaf Tobacco Covering Classes, Types and Groups of Grades § 30.8 Scrap. A byproduct from handling leaf tobacco in both the unstemmed and stemmed forms, consisting of loose and tangled portions of tobacco leaves, floor sweepings, and all other tobacco materials (except stems...

Tangled trios? Characterizing a hybrid zone in Castilleja (Orobanchaceae)

Treesearch

Erika l. Hersch-Green; Richard Cronn

2009-01-01

Hybridization and polyploidization are exceedingly important processes because both influence the ecological envelope and evolutionary trajectory of land plants. These processes are frequently invoked for Castilleja (Indian paintbrushes) as contributors to morphological and genetic novelty and as complicating factors in species delimitations. Here...

Probing the correlation of neuronal loss, neurofibrillary tangles, and cell death markers across the Alzheimer's disease Braak stages: a quantitative study in humans.

PubMed

Theofilas, Panos; Ehrenberg, Alexander J; Nguy, Austin; Thackrey, Julia M; Dunlop, Sara; Mejia, Maria B; Alho, Ana T; Paraizo Leite, Renata Elaine; Rodriguez, Roberta Diehl; Suemoto, Claudia K; Nascimento, Camila F; Chin, Marcus; Medina-Cleghorn, Daniel; Cuervo, Ana Maria; Arkin, Michelle; Seeley, William W; Miller, Bruce L; Nitrini, Ricardo; Pasqualucci, Carlos Augusto; Filho, Wilson Jacob; Rueb, Udo; Neuhaus, John; Heinsen, Helmut; Grinberg, Lea T

2018-01-01

Clarifying the mechanisms connecting neurofibrillary tangle (NFT) neurotoxicity to neuronal dysfunction in humans is likely to be pivotal for developing effective treatments for Alzheimer's disease (AD). To model the temporal progression of AD in humans, we used a collection of brains with controls and individuals from each Braak stage to quantitatively investigate the correlation between intraneuronal caspase activation or macroautophagy markers, NFT burden, and neuronal loss, in the dorsal raphe nucleus and locus coeruleus, the earliest vulnerable areas to NFT accumulation. We fit linear regressions with each count as outcomes, with Braak score and age as the predictors. In progressive Braak stages, intraneuronal active caspase-6 positivity increases both alone and overlapping with NFTs. Likewise, the proportion of NFT-bearing neurons showing autophagosomes increases. Overall, caspases may be involved in upstream cascades in AD and are associated with higher NFTs. Macroautophagy changes correlate with increasing NFT burden from early AD stages. Copyright © 2017 Elsevier Inc. All rights reserved.

Long-term biopersistence of tangled oxidized carbon nanotubes inside and outside macrophages in rat subcutaneous tissue

NASA Astrophysics Data System (ADS)

Sato, Yoshinori; Yokoyama, Atsuro; Nodasaka, Yoshinobu; Kohgo, Takao; Motomiya, Kenichi; Matsumoto, Hiroaki; Nakazawa, Eiko; Numata, Tomoko; Zhang, Minfang; Yudasaka, Masako; Hara, Hideyuki; Araki, Rikita; Tsukamoto, Osamu; Saito, Hiroaki; Kamino, Takeo; Watari, Fumio; Tohji, Kazuyuki

2013-08-01

Because of their mechanical strength, chemical stability, and low molecular weight, carbon nanotubes (CNTs) are attractive biological implant materials. Biomaterials are typically implanted into subcutaneous tissue or bone; however, the long-term biopersistence of CNTs in these tissues is unknown. Here, tangled oxidized multi-walled CNTs (t-ox-MWCNTs) were implanted into rat subcutaneous tissues and structural changes in the t-ox-MWCNTs located inside and outside of macrophages were studied for 2 years post-implantation. The majority of the large agglomerates were present in the intercellular space, maintained a layered structure, and did not undergo degradation. By contrast, small agglomerates were found inside macrophages, where they were gradually degraded in lysosomes. None of the rats displayed symptoms of cancer or severe inflammatory reactions such as necrosis. These results indicate that t-ox-MWCNTs have high biopersistence and do not evoke adverse events in rat subcutaneous tissue in vivo, demonstrating their potential utility as implantable biomaterials.

The Tangled Branches (Las Ramas Enredadas): Sexual Risk, Substance Abuse, and Intimate Partner Violence Among Hispanic Men who Have Sex with Men

PubMed Central

De Santis, Joseph P.; Gonzalez-Guarda, Rosa; Provencio-Vasquez, Elias; Deleon, Diego A.

2012-01-01

Hispanic men who have sex with men (MSM) experience a number of health disparities including high rates of HIV infection from high risk sex, substance abuse, and intimate partner violence. Although some research is available to document the relationships of these health disparities in the literature, few studies have explored the intersection of these disparities and the factors that influence them. The purpose of this study was to explore the experiences that Hispanic MSM residing in South Florida have with high risk sex, substance abuse, and intimate partner violence. Focus groups were conducted and analyzed using grounded theory methodology until data saturation was reached (n = 20). Two core categories with subcategories emerged from the data: The Roots of Risk (Los raices del riesgo) and The Tangled Branches (Las Ramas Enredadas). The results of the study provided some important clinical implications as well as directions for future research with Hispanic MSM. PMID:24084703

Tangled up Active Region

NASA Image and Video Library

2017-12-08

This close-up image of the sun presents an active region in profile as it rotated out of view. We can observe both the bright arching field lines and smaller pieces of darker matter in their midst being pulled back and forth just above the Sun's surface over about 36 hours (July 20-22, 2011). Both of these physical responses were caused by strong, tangled magnetic forces that are constantly evolving and reorganizing within the active region. Other active regions can be seen in the foreground as well. The image and movie were taken in extreme ultraviolet light of ionized iron heated to one million degrees. To view a hd video of this event go here: www.flickr.com/photos/gsfc/6006013038 Credit: NASA/GSFC/SDO NASA Goddard Space Flight Center enables NASA’s mission through four scientific endeavors: Earth Science, Heliophysics, Solar System Exploration, and Astrophysics. Goddard plays a leading role in NASA’s accomplishments by contributing compelling scientific knowledge to advance the Agency’s mission. Follow us on Twitter Like us on Facebook Find us on Instagram

Avalanche of entanglement and correlations at quantum phase transitions.

PubMed

Krutitsky, Konstantin V; Osterloh, Andreas; Schützhold, Ralf

2017-06-16

We study the ground-state entanglement in the quantum Ising model with nearest neighbor ferromagnetic coupling J and find a sequential increase of entanglement depth d with growing J. This entanglement avalanche starts with two-point entanglement, as measured by the concurrence, and continues via the three-tangle and four-tangle, until finally, deep in the ferromagnetic phase for J = ∞, arriving at a pure L-partite (GHZ type) entanglement of all L spins. Comparison with the two, three, and four-point correlations reveals a similar sequence and shows strong ties to the above entanglement measures for small J. However, we also find a partial inversion of the hierarchy, where the four-point correlation exceeds the three- and two-point correlations, well before the critical point is reached. Qualitatively similar behavior is also found for the Bose-Hubbard model, suggesting that this is a general feature of a quantum phase transition. This should be taken into account in the approximations starting from a mean-field limit.

The Tangled Branches (Las Ramas Enredadas): sexual risk, substance abuse, and intimate partner violence among Hispanic men who have sex with men.

PubMed

De Santis, Joseph P; Gonzalez-Guarda, Rosa; Provencio-Vasquez, Elias; Deleon, Diego A

2014-01-01

Hispanic men who have sex with men (MSM) experience a number of health disparities including high rates of HIV infection from high-risk sex, substance abuse, and intimate partner violence. Although some research is available to document the relationships of these health disparities in the literature, few studies have explored the intersection of these disparities and the factors that influence them. The purpose of this study was to explore the experiences that Hispanic MSM residing in South Florida have with high-risk sex, substance abuse, and intimate partner violence. Focus groups were conducted and analyzed using grounded theory methodology until data saturation was reached (n = 20). Two core categories with subcategories emerged from the data: The Roots of Risk (Los raices del riesgo) and The Tangled Branches (Las Ramas Enredadas). The results of the study provided some important clinical implications as well as directions for future research with Hispanic MSM.

Brain Tocopherols Related to Alzheimer Disease Neuropathology in Humans

PubMed Central

Morris, Martha Clare; Schneider, Julie A; Li, Hong; Tangney, Christy C; Nag, Sukrit; Bennett, David A; Honer, William G.; Barnes, Lisa

2014-01-01

Randomized trials of α-tocopherol supplements on cognitive decline are negative whereas studies of dietary tocopherols show benefit. We investigated these inconsistencies by analyzing the relations of α- and γ-tocopherol brain concentrations to Alzheimer disease (AD) neuropathology among 115 deceased participants of the prospective Rush Memory and Aging Project. Associations of amyloid load and neurofibrillary tangle severity with brain tocopherol concentrations were examined in separate adjusted linear regression models. γ-tocopherol concentrations were associated with lower amyloid load (β= −2.10; p=.002) and lower neurofibrillary tangle severity (β= −1.16; p=0.02). Concentrations of α-tocopherol were not associated with AD neuropathology except as modified by γ-tocopherol: high α-tocopherol was associated with higher amyloid load when γ-tocopherol levels were low and with lower amyloid levels when γ-tocopherol levels were high (P for interaction=0.03). Brain concentrations of γ- and α-tocopherols may be associated with AD neuropathology in interrelated, complex ways. Randomized trials should consider the contribution of γ-tocopherol. PMID:24589434

Mammalian chiasma frequencies as a test of two theories of recombination.

PubMed

Burt, A; Bell, G

A broad survey of asexuality in the animal kingdom is sufficient to reject all theories of sex and recombination except two: the Red Queen and the Tangled Bank. The Red Queen theory states that an organism's biotic environment tends to be 'contrary', consistently evolving to the detriment of the organism; sex and recombination result in progeny genetically distinct from their parents and grandparents and thus less susceptible to the antagonistic advances made during the previous generations, particularly by their parasites. The alternative theory, the Tangled Bank, states that sex and recombination function to diversify the progeny from each other, thus reducing competition between them. An extensive survey of mammalian recombination shows that the total number of chiasmata in excess of one per bivalent is strongly correlated with generation time but uncorrelated with fecundity. We conclude that crossing-over may function to combat antagonists with short generation times but does not function to reduce sib competition. Chromosome number is selectively neutral with respect to these factors.

Vortex arrays and ciliary tangles underlie the feeding-swimming tradeoff in starfish larvae

NASA Astrophysics Data System (ADS)

Gilpin, William; Prakash, Vivek N.; Prakash, Manu

2016-11-01

Many marine invertebrates have larval stages covered in linear arrays of beating cilia, which propel the animal while simultaneously entraining planktonic prey. These bands are strongly conserved across taxa spanning four major superphyla, and they are responsible for the unusual morphologies of many invertebrates. However, few studies have investigated their underlying hydrodynamics. Here, we study the ciliary bands of starfish larvae, and discover a beautiful pattern of slowly-evolving vortices that surrounds the swimming animals. Closer inspection of the bands reveals unusual ciliary "tangles" analogous to topological defects that break-up and re-form as the animal adjusts its swimming stroke. Quantitative experiments and modeling demonstrate that these vortices create a physical tradeoff between feeding and swimming in heterogenous environments, which manifests as distinct flow patterns or "eigenstrokes" representing each behavior-potentially implicating neuronal control of cilia. This quantitative interplay between larval form and hydrodynamic function generalizes to other invertebrates, and illustrates the potential effects of active boundary conditions in other biological and synthetic systems.

Describing Soils: Calibration Tool for Teaching Soil Rupture Resistance

ERIC Educational Resources Information Center

Seybold, C. A.; Harms, D. S.; Grossman, R. B.

2009-01-01

Rupture resistance is a measure of the strength of a soil to withstand an applied stress or resist deformation. In soil survey, during routine soil descriptions, rupture resistance is described for each horizon or layer in the soil profile. The lower portion of the rupture resistance classes are assigned based on rupture between thumb and…

Geological structures control on earthquake ruptures: The Mw7.7, 2013, Balochistan earthquake, Pakistan

NASA Astrophysics Data System (ADS)

Vallage, A.; Klinger, Y.; Lacassin, R.; Delorme, A.; Pierrot-Deseilligny, M.

2016-10-01

The 2013 Mw7.7 Balochistan earthquake, Pakistan, ruptured the Hoshab fault. Left-lateral motion dominated the deformation pattern, although significant vertical motion is found along the southern part of the rupture. Correlation of high-resolution (2.5 m) optical satellite images provided horizontal displacement along the entire rupture. In parallel, we mapped the ground rupture geometry at 1:500 scale. We show that the azimuth of the ground rupture distributes mainly between two directions, N216° and N259°. The direction N216° matches the direction of preexisting geologic structures resulting from penetrative deformation caused by the nearby Makran subduction. Hence, during a significant part of its rupture, the 2013 Balochistan rupture kept switching between a long-term fault front and secondary branches, in which existence and direction are related to the compressional context. It shows unambiguous direct interactions between different preexisting geologic structures, regional stress, and dynamic-rupture stress, which controlled earthquake propagation path.

Mathematical modeling and numerical simulation of unilateral dynamic rupture propagation along very-long reverse faults

NASA Astrophysics Data System (ADS)

Hirano, S.

2017-12-01

For some great earthquakes, dynamic rupture propagates unilaterally along a horizontal direction of very-long reverse faults (e.g., the Mw9.1 Sumatra earthquake in 2004, the Mw8.0 Wenchuan earthquake in 2008, and the Mw8.8 Maule earthquake in 2010, etc.). It seems that barriers or creeping sections may not lay along the opposite region of the co-seismically ruptured direction. In fact, in the case of Sumatra, the Mw8.6 earthquake occurred in the opposite region only three months after the mainshock. Mechanism of unilateral mode-II rupture along a material interface has been investigated theoretically and numerically. For mode-II rupture propagating along a material interface, an analytical solution implies that co-seismic stress perturbation depends on the rupture direction (Weertman, 1980 JGR; Hirano & Yamashita, 2016 BSSA), and numerical modeling of plastic yielding contributes to simulating the unilateral rupture (DeDonteny et al., 2011 JGR). However, mode-III rupture may dominate for the very-long reverse faults, and it can be shown that stress perturbation due to mode-III rupture does not depend on the rupture direction. Hence, an effect of the material interface is insufficient to understand the mechanism of unilateral rupture along the very-long reverse faults. In this study, I consider a two-dimensional bimaterial system with interfacial dynamic mode-III rupture under an obliquely pre-stressed configuration (i.e., the maximum shear direction of the background stress is inclined from the interfacial fault). First, I derived an analytical solution of regularized elastic stress field around a steady-state interfacial slip pulse using the method of Rice et al. (2005 BSSA). Then I found that the total stress, which is the sum of the background stress and co-seismic stress perturbation, depends on the rupture direction even in the mode-III case. Second, I executed a finite difference numerical simulation with a plastic yielding model of Andrews (1978 JGR; 2005 JGR) and succeeded in a simulation of unilateral rupture propagation in some parameter ranges (see figure). This unilateral rupture might be caused by energy dissipation due to the plastic yielding process that concentrates in the vicinity of only one rupture tip depending on the rupture direction.

Laparoscopic uterine surgery as a risk factor for uterine rupture during pregnancy.

PubMed

Chao, An-Shine; Chang, Yao-Lung; Yang, Lan-Yan; Chao, Angel; Chang, Wei-Yang; Su, Sheng-Yuan; Wang, Chin-Jung

2018-01-01

The incidence of uterine rupture through a previous cesarean scar (CS) is declining as a result of a lower parity and fewer options for vaginal birth after cesarean. However, uterine ruptures attributable to other causes that traumatize the myometrium are on the rise. To determine whether changes in the causes of uterine rupture had occurred in recent years, we retrospective retrieved the clinical records of all singletons with uterine rupture observed in the delivery room of a Taiwanese tertiary obstetric center over a 15-year period. The overall uterine rupture rate was 3.8 per 10,000 deliveries. A total of 22 cases in 20 women (with two of them experiencing two episodes). Seven uterine ruptures occurred through a previous cesarean scar (CS ruptures, 32%), 13 through a non-cesarean scar (non-CS ruptures, 59%), whereas the remaining two (9%) were in women who did not previously undergo any surgery. All of the 13 non-CS ruptures were identified in women with a history of laparoscopic procedures to the uterus. Specifically, 10 (76%) occurred after a previous laparoscopic myomectomy, one (8%) following a hysteroscopic myomectomy, and two (16%) after a laparoscopic wedge resection of cornual ectopic pregnancy. Severe bleeding (blood loss >1500 mL) requiring transfusions was more frequent in women who experienced non-CS compared with CS ruptures (10 versus 1 case, respectively, P = 0.024). Patients with a history of endoscopic uterine surgery should be aware of uterine rupture during pregnancy.

Laparoscopic uterine surgery as a risk factor for uterine rupture during pregnancy

PubMed Central

Chao, An-Shine; Chang, Yao-Lung; Yang, Lan-Yan; Chao, Angel; Chang, Wei-Yang; Su, Sheng-Yuan

2018-01-01

The incidence of uterine rupture through a previous cesarean scar (CS) is declining as a result of a lower parity and fewer options for vaginal birth after cesarean. However, uterine ruptures attributable to other causes that traumatize the myometrium are on the rise. To determine whether changes in the causes of uterine rupture had occurred in recent years, we retrospective retrieved the clinical records of all singletons with uterine rupture observed in the delivery room of a Taiwanese tertiary obstetric center over a 15-year period. The overall uterine rupture rate was 3.8 per 10,000 deliveries. A total of 22 cases in 20 women (with two of them experiencing two episodes). Seven uterine ruptures occurred through a previous cesarean scar (CS ruptures, 32%), 13 through a non-cesarean scar (non-CS ruptures, 59%), whereas the remaining two (9%) were in women who did not previously undergo any surgery. All of the 13 non-CS ruptures were identified in women with a history of laparoscopic procedures to the uterus. Specifically, 10 (76%) occurred after a previous laparoscopic myomectomy, one (8%) following a hysteroscopic myomectomy, and two (16%) after a laparoscopic wedge resection of cornual ectopic pregnancy. Severe bleeding (blood loss >1500 mL) requiring transfusions was more frequent in women who experienced non-CS compared with CS ruptures (10 versus 1 case, respectively, P = 0.024). Patients with a history of endoscopic uterine surgery should be aware of uterine rupture during pregnancy. PMID:29787604

Penile fracture: a rare case of simultaneous rupture of the one corpus cavernosum and complete urethral rupture.

PubMed

Nale, Djordje; Bojanić, Nebojša; Nikić, Predrag

2015-01-01

Penile fracture is a traumatic rupture of tunica albuginea and the tumescent corpora cavernosa due to the nonphysiological bending of the penile shaft, presenting with or without rupture of corpus pongiosum and urethra. The incidence of concomitant injury of the urethra is 0-38%. Complete urethral rupture is rare, but it is almost always associated with bilateral corporeal injury. We presented a patient with complete urethral rupture, and rupture of the right cavernous body. According to the available literature, this case is extremely rare. Fracture of the penis is relatively uncommon and is considered a urologic emergency. Prompt surgical explo- ration and repair can preserve erectile and voiding function.

Linguine sign in musculoskeletal imaging: calf silicone implant rupture.

PubMed

Duryea, Dennis; Petscavage-Thomas, Jonelle; Frauenhoffer, Elizabeth E; Walker, Eric A

2015-08-01

Imaging findings of breast silicone implant rupture are well described in the literature. On MRI, the linguine sign indicates intracapsular rupture, while the presence of silicone particles outside the fibrous capsule indicates extracapsular rupture. The linguine sign is described as the thin, wavy hypodense wall of the implant within the hyperintense silicone on T2-weighted images indicative of rupture of the implant within the naturally formed fibrous capsule. Hyperintense T2 signal outside of the fibrous capsule is indicative of an extracapsular rupture with silicone granuloma formation. We present a rare case of a patient with a silicone calf implant rupture and discuss the MRI findings associated with this condition.

Distal Biceps Tendon Rupture

DTIC Science & Technology

2010-06-01

Distal Biceps Tendon Rupture Military Medicine Radiology Corner, 2006 Radiology Corner Distal Biceps Tendon Rupture Contributors: CPT Michael...treatment of a 56-year-old man with complete rupture of the distal biceps tendon . The mechanism of injury, symptoms, and findings at physical...be used in pre-operative planning. Introduction Rupture of the distal biceps tendon is a relatively uncommon injury, but delayed diagnosis may

Creep-rupture behavior of candidate Stirling engine iron supperalloys in high-pressure hydrogen. Volume 2: Hydrogen creep-rupture behavior

NASA Technical Reports Server (NTRS)

Bhattacharyya, S.; Peterman, W.; Hales, C.

1984-01-01

The creep rupture behavior of nine iron base and one cobalt base candidate Stirling engine alloys is evaluated. Rupture life, minimum creep rate, and time to 1% strain data are analyzed. The 3500 h rupture life stress and stress to obtain 1% strain in 3500 h are also estimated.

A comparison of pre-dropout and temporary rupture sessions in psychotherapy.

PubMed

Gülüm, I Volkan; Soygüt, Gonca; Safran, Jeremy D

2016-11-15

Although numerous studies have investigated the relationship between the therapeutic alliance and dropout, most have focused on the relationship between alliance quality and psychotherapy outcomes. To compare sessions with therapeutic alliance ruptures and two sessions prior to treatment dropout (pre-dropout) in terms of rupture subtypes, psychotherapists' behavior, attitudes, and session content. We implemented quantitative methods to select the sessions and qualitative methods to analyze them. We analyzed 16 temporary rupture sessions from 12 therapist-patient dyads and 16 pre-dropout sessions from 8 different therapist-patient dyads. The sessions originate from clinical psychology Master's or Doctoral students under supervision in either cognitive behavioral or schema therapy. Pre-dropout sessions were considered unrepaired rupture sessions while rupture sessions were subsequently repaired. Results revealed apparent differences and similarities between the session types in positive and negative psychotherapist behaviors, content intensity, and the type and frequency of ruptures. We explored three new rupture subtypes: attributing positive developments to other sources, indirect speech, and sarcastic hostility. A striking implication is that the frequency of positive and negative psychotherapist behaviors, ruptures, and session content is more likely to decrease in the pre-dropout sessions than in the temporary rupture sessions.

Clinical recovery of two hip adductor longus ruptures: a case-report of a soccer player

PubMed Central

2013-01-01

Background Non-operative treatment of acute hip adductor longus ruptures in athletes has been described in the literature. However, very limited information concerning the recovery of this type of injury exists. This case represented a unique possibility to study the recovery of two acute adductor longus ruptures, using novel, reliable and validated assessment methods. Case presentation A 22-year old male soccer player (Caucasian) sustained two subsequent acute adductor longus ruptures, one in each leg. The injuries occurred 10 months apart, and were treated non-surgically in both situations. He was evaluated using hip-strength assessments, self-report and ultrasonography until complete muscle-strength recovery of the hip adductors had occurred. The player was able to participate in a full soccer training session without experiencing pain 15 weeks after the first rupture, and 12 weeks after the second rupture. Full hip adductor muscle-strength recovery was obtained 52 weeks after the first rupture and 10 weeks after the second rupture. The adductor longus injuries, as verified by initial ultrasonography (10 days post-injury), showed evidence of a complete tendon rupture in both cases, with an almost identical imaging appearance. It was only at 6 and 10 weeks ultrasonographic follow-up that the first rupture was found to include a larger anatomical area than the second rupture. Conclusion From this case we can conclude that two apparently similar hip adductor longus ruptures, verified by initial ultrasonography (10 days post-injury), can have very different hip adductor strength recovery times. Assessment of adductor strength recovery may therefore in the future be a useful and important additional measure for determining when soccer players with hip adductor longus ruptures can return safely to play. PMID:23693119

Spontaneous rupture of splenic artery aneurysm in pregnancy: a case report.

PubMed

Gourgiotis, S; Alfaras, P; Salemis, N S

2008-01-01

Splenic artery aneurysms (SAA) occur predominantly in women, and the majority of them are asymptomatic until rupture. Over half of those that rupture occur during pregnancy. Spontaneously ruptured SAA during pregnancy is always a life-threatening surgical entity for both the mother and the fetus. We report the case of a 29-year-old woman at 34 weeks' gestation with spontaneous rupture of SAA who underwent emergency exploratory laparotomy and splenectomy. This case illustrates the need to consider ruptured SAA as part of important differential diagnosis in haemodynamically unstable pregnant women.

Glass rupture disk

DOEpatents

Glass, S. Jill; Nicolaysen, Scott D.; Beauchamp, Edwin K.

2002-01-01

A frangible rupture disk and mounting apparatus for use in blocking fluid flow, generally in a fluid conducting conduit such as a well casing, a well tubing string or other conduits within subterranean boreholes. The disk can also be utilized in above-surface pipes or tanks where temporary and controllable fluid blockage is required. The frangible rupture disk is made from a pre-stressed glass with controllable rupture properties wherein the strength distribution has a standard deviation less than approximately 5% from the mean strength. The frangible rupture disk has controllable operating pressures and rupture pressures.

Surface fault rupture during the Mw 7.8 Kaikoura earthquake, New Zealand, with specific comment on the Kekerengu Fault - one of the country's fastest slipping onland active faults

NASA Astrophysics Data System (ADS)

Van Dissen, Russ; Little, Tim

2017-04-01

The Mw 7.8 Kaikoura earthquake of 14 November, 2016 (NZDT) was a complex event. It involved ground-surface (or seafloor) fault rupture on at least a dozen onland or offshore faults, and subsurface rupture on a handful of additional faults. Most of the surface ruptures involved previously known (or suspected) active faults, as well as surface rupture on at least two hitherto unrecognised active faults. The southwest to northeast extent of surface fault rupture, as generalised by two straight-line segments, is approximately 180 km, though this is a minimum for the collective length of surface rupture due to multiple overlapping faults with various orientations. Surface rupture displacements on specific faults involved in the Kaikoura Earthquake span approximately two orders of magnitude. For example, maximum surface displacement on the Heaver's Creek Fault is cm- to dm-scale in size; whereas, maximum surface displacement on the nearby Kekerengu Fault is approximately 10-12 m (predominantly in a dextral sense). The Kekerengu Fault has a Late Pleistocene slip-rate rate of 20-26 mm/yr, and is possibly the second fastest slipping onland fault in New Zealand, behind the Alpine Fault. Located in the northeastern South Island of New Zealand, the Kekerengu Fault - along with the Hope Fault to the southwest and the Needles Fault offshore to the northeast - comprise the fastest slipping elements of the Pacific-Australian plate boundary in this part of the country. In January 2016 (about ten months prior to the Kaikoura earthquake) three paleo-earthquake investigation trenches were excavated across pronounced traces of the Kekerengu Fault at two locations. These were the first such trenches dug and evaluated across the fault. All three trenches displayed abundant evidence of past surface fault ruptures (three surface ruptures in the last approximately 1,200 years, four now including the 2016 rupture). An interesting aspect of the 2016 rupture is that two of the trenches received surface fault rupture, and are now dextrally offset by about 9 m, while the third trench did not have any 2016 surface rupture pass through it. In this instance, ground-surface rupture along this trace of the fault died out within tens of metres of the trench. Another salient aspect of the Kaikoura earthquake is that the determined (or estimated) recurrence intervals of the faults that ruptured the ground surface vary by an order of magnitude or more. This strongly implies that the ensemble of faults that ruptured with the Kekerengu Fault in the 2016 earthquake has not always been the same for past earthquakes. Possible reasons for this could include the state of stress at the time of a specific earthquake, the direction of rupture propagation, and whether or not rupture on one fault system cascades into rupture on another as is suspected to have happened in the Kaikoura earthquake.

Surface Rupture Characteristics and Rupture Mechanics of the Yushu Earthquake (Ms7.1), 14/04/2010

NASA Astrophysics Data System (ADS)

Pan, J.; Li, H.; Xu, Z.; Li, N.; Wu, F.; Guo, R.; Zhang, W.

2010-12-01

On April 14th 2010, a disastrous earthquake (Ms 7.1) struck Yushu County, Qinghai Province, China, killing thousands of people. This earthquake occurred as a result of sinistral strike-slip faulting on the western segment of the Xianshuihe Fault zone in eastern Tibetan Plateau. Our group conducted scientific investigation in the field on co-seismic surface rupture and active tectonics in the epicenter area immediately after the earthquake. Here, we introduce our preliminary results on the surface ruptures and rupture mechanics of the Yushu Earthquake. The surface rupture zone of Yushu earthquake, which is about 49 km-long, consists of 3 discontinuous left stepping rupture segments, which are 19 km, 22 km, and about 8 km, respectively, from west to east. Each segment consists of a series of right stepping en-echelon branch ruptures. The branch ruptures consist of interphase push-up and tension fissures or simply en-echelon tension fissures. The co-seismic displacements had been surveyed with a total station in detail on landmarks such as rivers, gullies, roads, farmlands, wire poles, and fences. The maximum offset measured is 2.3m, located near the Guoyangyansongduo Village. There are 3 offset peaks along the rupture zone corresponding to the 3 segments of the surface rupture zone. The maximum offsets in the west, central, and east segment rupture zones are 1.4m, 2.3m, and 1.6m respectively. The surface rupture zone of Yushu earthquake strikes in a 310°NW direction. The fault plane dips to the northeast and the dip angle is about 81°. The rupture zone is developed in transtension setting. Tension normal fault developed during the sinistral strike-slip process of the fault. The valley west of Yushu City and the Longbao Lake are both pull-apart basins formed during the transtension activity of the fault.

Historic Surface Rupture Informing Probabilistic Fault Displacement Analysis: New Zealand Case Studies

NASA Astrophysics Data System (ADS)

Villamor, P.; Litchfield, N. J.; Van Dissen, R. J.; Langridge, R.; Berryman, K. R.; Baize, S.

2016-12-01

Surface rupture associated with the 2010 Mw7.1 Darfield Earthquake (South Island, New Zealand) was extremely well documented, thanks to an immediate field mapping response and the acquisition of LiDAR data within days of the event. With respect to informing Probabilistic Fault Displacement Analysis (PFDHA) the main insights and outcomes from this rupture through Quaternary gravel are: 1) significant distributed deformation either side of the main trace (30 to 300 m wide deformation zone) and how the deformation is distributed away from the main trace; 2) a thorough analysis of uncertainty of the displacement measures obtained using the LIDAR data and repeated measurements from several scientists; and 3) the short surface rupture length for the reported magnitude, resulting from complex fault rupture with 5-6 reverse and strike-slip strands, most of which had no surface rupture. While the 2010 event is extremely well documented and will be an excellent case to add to the Surface Rupture during Earthquakes database (SURE), other NZ historical earthquakes that are not so well documented, but can provide important information for PFDHA. New Zealand has experienced about 10 historical surface fault ruptures since 1848, comprising ruptures on strike-slip, reverse and normal faults. Mw associated with these ruptures ranges between 6.3 and 8.1. From these ruptures we observed that the surface expression of deformation can be influenced by: fault maturity; the type of Quaternary sedimentary cover; fault history (e.g., influence of inversion tectonics, flexural slip); fault complexity; and primary versus secondary rupture. Other recent >Mw 6.6 earthquakes post-2010 that did not rupture the ground surface have been documented with InSAR and can inform Mw thresholds for surface fault rupture. It will be important to capture all this information and that of similar events worldwide to inform the SURE database and ultimately PFDHA.

Global catalog of earthquake rupture velocities shows anticorrelation between stress drop and rupture velocity

NASA Astrophysics Data System (ADS)

Chounet, Agnès; Vallée, Martin; Causse, Mathieu; Courboulex, Françoise

2018-05-01

Application of the SCARDEC method provides the apparent source time functions together with seismic moment, depth, and focal mechanism, for most of the recent earthquakes with magnitude larger than 5.6-6. Using this large dataset, we have developed a method to systematically invert for the rupture direction and average rupture velocity Vr, when unilateral rupture propagation dominates. The approach is applied to all the shallow (z < 120 km) earthquakes of the catalog over the 1992-2015 time period. After a careful validation process, rupture properties for a catalog of 96 earthquakes are obtained. The subsequent analysis of this catalog provides several insights about the seismic rupture process. We first report that up-dip ruptures are more abundant than down-dip ruptures for shallow subduction interface earthquakes, which can be understood as a consequence of the material contrast between the slab and the overriding crust. Rupture velocities, which are searched without any a-priori up to the maximal P wave velocity (6000-8000 m/s), are found between 1200 m/s and 4500 m/s. This observation indicates that no earthquakes propagate over long distances with rupture velocity approaching the P wave velocity. Among the 23 ruptures faster than 3100 m/s, we observe both documented supershear ruptures (e.g. the 2001 Kunlun earthquake), and undocumented ruptures that very likely include a supershear phase. We also find that the correlation of Vr with the source duration scaled to the seismic moment (Ts) is very weak. This directly implies that both Ts and Vr are anticorrelated with the stress drop Δσ. This result has implications for the assessment of the peak ground acceleration (PGA) variability. As shown by Causse and Song (2015), an anticorrelation between Δσ and Vr significantly reduces the predicted PGA variability, and brings it closer to the observed variability.

Long-Period Ground Motion due to Near-Shear Earthquake Ruptures

NASA Astrophysics Data System (ADS)

Koketsu, K.; Yokota, Y.; Hikima, K.

2010-12-01

Long-period ground motion has become an increasingly important consideration because of the recent rapid increase in the number of large-scale structures, such as high-rise buildings and large oil storage tanks. Large subduction-zone earthquakes and moderate to large crustal earthquakes can generate far-source long-period ground motions in distant sedimentary basins with the help of path effects. Near-fault long-period ground motions are generated, for the most part, by the source effects of forward rupture directivity (Koketsu and Miyake, 2008). This rupture directivity effect is the maximum in the direction of fault rupture when a rupture velocity is nearly equal to shear wave velocity around a source fault (Dunham and Archuleta, 2005). The near-shear rupture was found to occur during the 2008 Mw 7.9 Wenchuan earthquake at the eastern edge of the Tibetan plateau (Koketsu et al., 2010). The variance of waveform residuals in a joint inversion of teleseismic and strong motion data was the minimum when we adopted a rupture velocity of 2.8 km/s, which is close to the shear wave velocity of 2.6 km/s around the hypocenter. We also found near-shear rupture during the 2010 Mw 6.9 Yushu earthquake (Yokota et al., 2010). The optimum rupture velocity for an inversion of teleseismic data is 3.5 km/s, which is almost equal to the shear wave velocity around the hypocenter. Since, in addition, supershear rupture was found during the 2001 Mw 7.8 Central Kunlun earthquake (Bouchon and Vallee, 2003), such fast earthquake rupture can be a characteristic of the eastern Tibetan plateau. Huge damage in Yingxiu and Beichuan from the 2008 Wenchuan earthquake and damage heavier than expected in the county seat of Yushu from the medium-sized Yushu earthquake can be attributed to the maximum rupture directivity effect in the rupture direction due to near-shear earthquake ruptures.

Cultural politics: Linguistic identity and its role as gatekeeper in the science classroom

NASA Astrophysics Data System (ADS)

Hilton-Brown, Bryan Anthony

This dissertation investigated how participation in the cultural practices of science classrooms creates intrapersonal conflict for ethnic minority students. Grounded in research perspectives of cultural anthropology, sociocultural studies of science education, and critical pedagogy, this study examined the cultural tensions encountered by minority students as they assimilate into the culture of the science classroom. Classroom interaction was viewed from the perspective of instructional congruence---the active incorporation of students' culture into science pedagogy. Ogbu's notion of "oppositional identity", Fordham's "fictive kinship", Bahktin's "antidialogics", and Freire's "critical consciousness" were brought together to examine how members of marginalized cultures develop non-normative behaviors as a means of cultural resistance. Choice of genre for public discourse was seen as a political act, representing students' own cultural affiliations. Conducted in a diverse Southern Californian high school with an annual population of over 3,900 students, this study merged ethnographic research, action research, and sociolinguistic discourse analysis. Post hoc analysis of videotaped classroom activities, focus group interviews, and samples of student work revealed students' discursive behavior to shift as a product of the context of their discursive exchanges. In whole class discussions students explained their understanding of complex phenomena to classmates, while in small group discussions they favored brief exchanges of group data. Four domains of discursive identities were identified: Opposition Status, Maintenance Status, Incorporation Status, and Proficiency Status. Students demonstrating Opposition Status avoided use of science discourse. Those students who demonstrated Maintenance Status were committed to maintaining their own discursive behavior. Incorporation Status students were characterized by an active attempt to incorporate science discourse into their cultural speech patterns. Proficiency Status students demonstrated a fluency in applying features of scientific discourse into their current speech genre. Focus group interviews confirmed students' cultural resistance to science discourse, despite their complex understanding of the role, purpose, and function of science discourse as social practice. These findings contribute to an ongoing discussion of how scientists, science teachers, and science education researchers can create equitable learning environments that reflect the components of students' ethnic and cultural backgrounds.

Exploring HRD in two Welsh NHS Trusts: analysing the discursive resources used by senior managers.

PubMed

Sambrook, Sally

2007-01-01

The purpose of this paper is to examine human resource development (HRD) in the UK National Health Service (NHS), and particularly in two Welsh NHS Trusts, to help illuminate the various ways in which learning, training and development are talked about. The NHS is a complex organisation, not least with its recent devolution and separation into the four distinct countries of the UK. Within this, there are multiple and often conflicting approaches to human resource development associated with the various forms of employee, professional (nursing, medical etc.), managerial and organisational development. How people are developed is crucial to developing a modern health service, and yet, with the diverse range of health workers, HRD is a complex process, and one which receives little attention. Managers have a key role and their perceptions of HRD can be analysed through the discursive resources they employ. From an interpretivist stance, the paper employs semi-structured interviews with seven Directorate-General Managers, and adopts discourse analysis to explore how HRD is talked about in two Welsh NHS Trusts. The paper finds some of the different discourses used by different managers, including those with a nursing background and those without. It examines how they talk about HRD, and also explores their own (management) development and the impact this has had on their sense of identity. The paper highlights some of the tensions associated with HRD in the NHS, including ambiguities between professional and managerial development, the functional and physical fragmentation of HRD, conflict between a focus on performance/service delivery and the need to learn, discursive dissonance between the use of the terms training and learning, a delicate balance between "going on courses" and informal, work-related learning, inequities regarding "protected time" and discourses shifting between competition and cooperation. These tensions are exposed to help develop a shared understanding of the complexities of HRD within the NHS. The paper concludes with a summary of the different discursive resources employed by senior managers to articulate and accomplish HRD. These are "surfaced" to enable managers and HRD practitioners, amongst others, to construct common repertoires and shared meaning.

Open versus endovascular repair of ruptured abdominal aortic aneurysms: What have we learned after more than 2 decades of ruptured endovascular aneurysm repair?

PubMed

Robinson, William P

2017-12-01

Ruptured abdominal aortic aneurysm is one of the most difficult clinical problems in surgical practice, with extraordinarily high morbidity and mortality. During the past 23 years, the literature has become replete with reports regarding ruptured endovascular aneurysm repair. A variety of study designs and databases have been utilized to compare ruptured endovascular aneurysm repair and open surgical repair for ruptured abdominal aortic aneurysm and studies of various designs from different databases have yielded vastly different conclusions. It therefore remains controversial whether ruptured endovascular aneurysm repair improves outcomes after ruptured abdominal aortic aneurysm in comparison to open surgical repair. The purpose of this article is to review the best available evidence comparing ruptured endovascular aneurysm repair and open surgical repair of ruptured abdominal aortic aneurysm, including single institution and multi-institutional retrospective observational studies, large national population-based studies, large national registries of prospectively collected data, and randomized controlled clinical trials. This article will analyze the study designs and databases utilized with their attendant strengths and weaknesses to understand the sometimes vastly different conclusions the studies have reached. This article will attempt to integrate the data to distill some of the lessons that have been learned regarding ruptured endovascular aneurysm repair and identify ongoing needs in this field. Copyright © 2017 Elsevier Inc. All rights reserved.

Aneurysm Morphology and Prediction of Rupture: An International Study of Unruptured Intracranial Aneurysms Analysis.

PubMed

Mocco, J; Brown, Robert D; Torner, James C; Capuano, Ana W; Fargen, Kyle M; Raghavan, Madhavan L; Piepgras, David G; Meissner, Irene; Huston, John

2018-04-01

There are conflicting data between natural history studies suggesting a very low risk of rupture for small, unruptured intracranial aneurysms and retrospective studies that have identified a much higher frequency of small, ruptured aneurysms than expected. To use the prospective International Study of Unruptured Intracranial Aneurysms cohort to identify morphological characteristics predictive of unruptured intracranial aneurysm rupture. A case-control design was used to analyze morphological characteristics associated with aneurysm rupture in the International Study of Unruptured Intracranial Aneurysms database. Fifty-seven patients with ruptured aneurysms during follow-up were matched (by size and location) with 198 patients with unruptured intracranial aneurysms without rupture during follow-up. Twelve morphological metrics were measured from cerebral angiograms in a blinded fashion. Perpendicular height (P = .008) and size ratio (ratio of maximum diameter to the parent vessel diameter; P = .01) were predictors of aneurysm rupture on univariate analysis. Aspect ratio, daughter sacs, multiple lobes, aneurysm angle, neck diameter, parent vessel diameter, and calculated aneurysm volume were not statistically significant predictors of rupture. On multivariate analysis, perpendicular height was the only significant predictor of rupture (Chi-square 7.1, P-value .008). This study underscores the importance of other morphological factors, such as perpendicular height and size ratio, that may influence unruptured intracranial aneurysm rupture risk in addition to greatest diameter and anterior vs posterior location.

7 CFR 29.3533 - Nested.

Code of Federal Regulations, 2013 CFR

2013-01-01

... INSPECTION Standards Official Standard Grades for Dark Air-Cured Tobacco (u.s. Types 35, 36, 37 and Foreign... arranged to conceal foreign matter or tobacco of inferior grade, quality, or condition. Nested includes: (a) Any lot of tobacco which contains foreign matter or damaged, injured, tangled, or other inferior...

7 CFR 29.3533 - Nested.

Code of Federal Regulations, 2012 CFR

2012-01-01

... INSPECTION Standards Official Standard Grades for Dark Air-Cured Tobacco (u.s. Types 35, 36, 37 and Foreign... arranged to conceal foreign matter or tobacco of inferior grade, quality, or condition. Nested includes: (a) Any lot of tobacco which contains foreign matter or damaged, injured, tangled, or other inferior...

7 CFR 29.3533 - Nested.

Code of Federal Regulations, 2011 CFR

2011-01-01

... INSPECTION Standards Official Standard Grades for Dark Air-Cured Tobacco (u.s. Types 35, 36, 37 and Foreign... arranged to conceal foreign matter or tobacco of inferior grade, quality, or condition. Nested includes: (a) Any lot of tobacco which contains foreign matter or damaged, injured, tangled, or other inferior...

7 CFR 29.3533 - Nested.

Code of Federal Regulations, 2014 CFR

2014-01-01

... INSPECTION Standards Official Standard Grades for Dark Air-Cured Tobacco (u.s. Types 35, 36, 37 and Foreign... arranged to conceal foreign matter or tobacco of inferior grade, quality, or condition. Nested includes: (a) Any lot of tobacco which contains foreign matter or damaged, injured, tangled, or other inferior...

"Mississippi Trial, 1955": Tangling with Text through Reading, Discussion, and Writing

ERIC Educational Resources Information Center

Grierson, Sirpa; Thursby, Jacqueline S.; Dean, Deborah; Crowe, Chris

2007-01-01

The authors proffer practical critical-reading strategies for teaching "Mississippi Trial, 1955" to increase students' vocabulary, comprehension, and background knowledge of historical eras. They use nonfiction, a PBS documentary, the Web, folklore, and picture books among other tools for inciting thoughtful discussion and writing.

Can we make a new deal? Entitlement reform sounds alluring, but the reality is stark.

PubMed

Wagner, L

1995-01-20

After simmering for more than a decade, the Great Entitlement Debate promises to dominate the 1995 congressional agenda. But lost amid a tangle of conflicting parochial interests, voter confusion and searing partisan rhetoric are some harsh truths about our options.

Geometrically controlled evolution of four-qubit states

NASA Astrophysics Data System (ADS)

Duy, Hoang Ngoc; Heydari, Hoshang

2011-03-01

In this paper the evolution of some states of four qubits in [1] under global bipartite unitary operation and controlled by local unitary operation using four-tangle [2] and the geometric invariants [3] is investigated. Particularly the entanglement distribution and properties of these four-qubit states are studied.

7 CFR 29.6022 - Leaf scrap.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 7 Agriculture 2 2011-01-01 2011-01-01 false Leaf scrap. 29.6022 Section 29.6022 Agriculture... INSPECTION Standards Definitions § 29.6022 Leaf scrap. A byproduct of unstemmed tobacco Leaf scrap results from handling unstemmed tobacco and consists of loose and tangled whole or broken leaves. ...

7 CFR 29.6022 - Leaf scrap.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 7 Agriculture 2 2010-01-01 2010-01-01 false Leaf scrap. 29.6022 Section 29.6022 Agriculture... INSPECTION Standards Definitions § 29.6022 Leaf scrap. A byproduct of unstemmed tobacco Leaf scrap results from handling unstemmed tobacco and consists of loose and tangled whole or broken leaves. ...

7 CFR 29.6022 - Leaf scrap.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 7 Agriculture 2 2014-01-01 2014-01-01 false Leaf scrap. 29.6022 Section 29.6022 Agriculture... INSPECTION Standards Definitions § 29.6022 Leaf scrap. A byproduct of unstemmed tobacco Leaf scrap results from handling unstemmed tobacco and consists of loose and tangled whole or broken leaves. ...

7 CFR 29.6022 - Leaf scrap.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 7 Agriculture 2 2013-01-01 2013-01-01 false Leaf scrap. 29.6022 Section 29.6022 Agriculture... INSPECTION Standards Definitions § 29.6022 Leaf scrap. A byproduct of unstemmed tobacco Leaf scrap results from handling unstemmed tobacco and consists of loose and tangled whole or broken leaves. ...

7 CFR 29.6022 - Leaf scrap.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 7 Agriculture 2 2012-01-01 2012-01-01 false Leaf scrap. 29.6022 Section 29.6022 Agriculture... INSPECTION Standards Definitions § 29.6022 Leaf scrap. A byproduct of unstemmed tobacco Leaf scrap results from handling unstemmed tobacco and consists of loose and tangled whole or broken leaves. ...

Real-Time Detection of Rupture Development: Earthquake Early Warning Using P Waves From Growing Ruptures

NASA Astrophysics Data System (ADS)

Kodera, Yuki

2018-01-01

Large earthquakes with long rupture durations emit P wave energy throughout the rupture period. Incorporating late-onset P waves into earthquake early warning (EEW) algorithms could contribute to robust predictions of strong ground motion. Here I describe a technique to detect in real time P waves from growing ruptures to improve the timeliness of an EEW algorithm based on seismic wavefield estimation. The proposed P wave detector, which employs a simple polarization analysis, successfully detected P waves from strong motion generation areas of the 2011 Mw 9.0 Tohoku-oki earthquake rupture. An analysis using 23 large (M ≥ 7) events from Japan confirmed that seismic intensity predictions based on the P wave detector significantly increased lead times without appreciably decreasing the prediction accuracy. P waves from growing ruptures, being one of the fastest carriers of information on ongoing rupture development, have the potential to improve the performance of EEW systems.

Resolution of alliance ruptures: The special case of animal-assisted psychotherapy.

PubMed

Zilcha-Mano, Sigal

2017-01-01

Many therapists regard alliance ruptures as one of the greatest challenges therapists face in the therapy room. Alliance ruptures has been previously defined as breakdowns in the process of negotiation of treatment tasks and goals and a deterioration in the affective bond between patient and therapist. Alliance ruptures have been found to predict premature termination of treatment and poor treatment outcomes. But ruptures can also present important opportunities for gaining insight and awareness and for facilitating therapeutic change. A process of rupture resolution may lead to beneficial outcomes and serve as a corrective emotional experience. The article describes unique processes of alliance rupture resolution inherent in animal-assisted psychotherapy (AAP). Building on Safran and Muran's model and on clinical examples, the article describes strategies for identifying ruptures in AAP and techniques for repairing them to facilitate a corrective experience in treatment. Implications for clinical practice and future research are discussed.

Diagnosis and management of testicular rupture after blunt scrotal trauma: a literature review.

PubMed

Wang, Zhao; Yang, Jin-Rui; Huang, Yu-Meng; Wang, Long; Liu, Long-Fei; Wei, Yong-Bao; Huang, Liang; Zhu, Quan; Zeng, Ming-Qiang; Tang, Zheng-Yan

2016-12-01

Testicular rupture, one of the most common complications in blunt scrotal trauma, is the rupture of tunica albuginea and extrusion of seminiferous tubules. Testicular rupture is more inclined to young men, and injury mechanisms are associated with sports and motor accidents. After history taking and essential physical examination, scrotal ultrasound is the first-line auxiliary examination. MRI is also one of the vital complementary examinations to evaluate testicular rupture after blunt scrotal trauma. Surgical exploration and repair may be necessary when the diagnosis of testicular rupture is definite or suspicious. Postoperative follow-up is to monitor the relief of local symptoms and changes of testicular functions. This review sums up the literatures about testicular rupture after blunt scrotal trauma in recent 16 years and also refers some new advantages and perspectives on diagnosis and management of testicular rupture.

Ruptured Tendons in Anabolic-Androgenic Steroid Users: A Cross-Sectional Cohort Study.

PubMed

Kanayama, Gen; DeLuca, James; Meehan, William P; Hudson, James I; Isaacs, Stephanie; Baggish, Aaron; Weiner, Rory; Micheli, Lyle; Pope, Harrison G

2015-11-01

Accumulating case reports have described tendon rupture in men who use anabolic-androgenic steroids (AAS). However, no controlled study has assessed the history of tendon rupture in a large cohort of AAS users and comparison nonusers. Men reporting long-term AAS abuse would report an elevated lifetime incidence of tendon rupture compared with non-AAS-using bodybuilders. Cohort study; Level of evidence, 3. Medical histories were obtained from 142 experienced male bodybuilders aged 35 to 55 years recruited in the course of 2 studies. Of these men, 88 reported at least 2 years of cumulative lifetime AAS use, and 54 reported no history of AAS use. In men reporting a history of tendon rupture, the circumstances of the injury, prodromal symptoms, concomitant drug or alcohol use, and details of current and lifetime AAS use (if applicable) were recorded. Surgical records were obtained for most participants. Nineteen (22%) of the AAS users, but only 3 (6%) of the nonusers, reported at least 1 lifetime tendon rupture. The hazard ratio for a first ruptured tendon in AAS users versus nonusers was 9.0 (95% CI, 2.5-32.3; P < .001). Several men reported 2 or more independent lifetime tendon ruptures. Interestingly, upper-body tendon ruptures occurred exclusively in the AAS group (15 [17%] AAS users vs 0 nonusers; risk difference, 0.17 [95% CI, 0.09-0.25]; P < .001 [hazard ratio not estimable]), whereas there was no significant difference between users and nonusers in risk for lower-body ruptures (6 [7%] AAS users, 3 [6%] nonusers; hazard ratio, 3.1 [95% CI, 0.7-13.8]; P = .13). Of 31 individual tendon ruptures assessed, only 6 (19%) occurred while weightlifting, with the majority occurring during other sports activities. Eight (26%) ruptures followed prodromal symptoms of nonspecific pain in the region. Virtually all ruptures were treated surgically, with complete or near-complete ultimate restoration of function. AAS abusers, compared with otherwise similar bodybuilders, showed a markedly increased risk of tendon ruptures, particularly upper-body tendon rupture. © 2015 The Author(s).

A novel strategy to translate the biomechanical rupture risk of abdominal aortic aneurysms to their equivalent diameter risk: method and retrospective validation.

PubMed

Gasser, T C; Nchimi, A; Swedenborg, J; Roy, J; Sakalihasan, N; Böckler, D; Hyhlik-Dürr, A

2014-03-01

To translate the individual abdominal aortic aneurysm (AAA) patient's biomechanical rupture risk profile to risk-equivalent diameters, and to retrospectively test their predictability in ruptured and non-ruptured aneurysms. Biomechanical parameters of ruptured and non-ruptured AAAs were retrospectively evaluated in a multicenter study. General patient data and high resolution computer tomography angiography (CTA) images from 203 non-ruptured and 40 ruptured aneurysmal infrarenal aortas. Three-dimensional AAA geometries were semi-automatically derived from CTA images. Finite element (FE) models were used to predict peak wall stress (PWS) and peak wall rupture index (PWRI) according to the individual anatomy, gender, blood pressure, intra-luminal thrombus (ILT) morphology, and relative aneurysm expansion. Average PWS diameter and PWRI diameter responses were evaluated, which allowed for the PWS equivalent and PWRI equivalent diameters for any individual aneurysm to be defined. PWS increased linearly and PWRI exponentially with respect to maximum AAA diameter. A size-adjusted analysis showed that PWS equivalent and PWRI equivalent diameters were increased by 7.5 mm (p = .013) and 14.0 mm (p < .001) in ruptured cases when compared to non-ruptured controls, respectively. In non-ruptured cases the PWRI equivalent diameters were increased by 13.2 mm (p < .001) in females when compared with males. Biomechanical parameters like PWS and PWRI allow for a highly individualized analysis by integrating factors that influence the risk of AAA rupture like geometry (degree of asymmetry, ILT morphology, etc.) and patient characteristics (gender, family history, blood pressure, etc.). PWRI and the reported annual risk of rupture increase similarly with the diameter. PWRI equivalent diameter expresses the PWRI through the diameter of the average AAA that has the same PWRI, i.e. is at the same biomechanical risk of rupture. Consequently, PWRI equivalent diameter facilitates a straightforward interpretation of biomechanical analysis and connects to diameter-based guidelines for AAA repair indication. PWRI equivalent diameter reflects an additional diagnostic parameter that may provide more accurate clinical data for AAA repair indication. Copyright © 2013 European Society for Vascular Surgery. Published by Elsevier Ltd. All rights reserved.

Great earthquakes of variable magnitude at the Cascadia subduction zone

USGS Publications Warehouse

Nelson, A.R.; Kelsey, H.M.; Witter, R.C.

2006-01-01

Comparison of histories of great earthquakes and accompanying tsunamis at eight coastal sites suggests plate-boundary ruptures of varying length, implying great earthquakes of variable magnitude at the Cascadia subduction zone. Inference of rupture length relies on degree of overlap on radiocarbon age ranges for earthquakes and tsunamis, and relative amounts of coseismic subsidence and heights of tsunamis. Written records of a tsunami in Japan provide the most conclusive evidence for rupture of much of the plate boundary during the earthquake of 26 January 1700. Cascadia stratigraphic evidence dating from about 1600??cal yr B.P., similar to that for the 1700 earthquake, implies a similarly long rupture with substantial subsidence and a high tsunami. Correlations are consistent with other long ruptures about 1350??cal yr B.P., 2500??cal yr B.P., 3400??cal yr B.P., 3800??cal yr B.P., 4400??cal yr B.P., and 4900??cal yr B.P. A rupture about 700-1100??cal yr B.P. was limited to the northern and central parts of the subduction zone, and a northern rupture about 2900??cal yr B.P. may have been similarly limited. Times of probable short ruptures in southern Cascadia include about 1100??cal yr B.P., 1700??cal yr B.P., 3200??cal yr B.P., 4200??cal yr B.P., 4600??cal yr B.P., and 4700??cal yr B.P. Rupture patterns suggest that the plate boundary in northern Cascadia usually breaks in long ruptures during the greatest earthquakes. Ruptures in southernmost Cascadia vary in length and recurrence intervals more than ruptures in northern Cascadia.

Total rupture of hydatid cyst of liver in to common bile duct: a case report.

PubMed

Robleh, Hassan; Yassine, Fahmi; Driss, Khaiz; Khalid, Elhattabi; Fatima-Zahra, Bensardi; Saad, Berrada; Rachid, Lefriyekh; Abdalaziz, Fadil; Najib, Zerouali Ouariti

2014-01-01

Rupture of hydatid liver cyst into biliary tree is frequent complications that involve the common hepatic duct, lobar biliary branches, the small intrahepatic bile ducts,but rarely rupture into common bile duct. The rupture of hydatid cyst is serious life threating event. The authors are reporting a case of total rupture of hydatid cyst of liver into common bile duct. A 50-year-old male patient who presented with acute cholangitis was diagnosed as a case of totally rupture of hydatid cyst on Abdominal CT Scan. Rupture of hydatid cyst of liver into common bile duct and the gallbladder was confirmed on surgery. Treated by cholecystectomy and T-tube drainage of Common bile duct.

Ruptured Tendons in Anabolic-Androgenic Steroid Users: A Cross-Sectional Cohort Study

PubMed Central

Kanayama, Gen; DeLuca, James; Meehan, William P.; Hudson, James I.; Isaacs, Stephanie; Baggish, Aaron; Weiner, Rory; Micheli, Lyle; Pope, Harrison G.

2016-01-01

Background Accumulating case reports have described tendon rupture in men using anabolic-androgenic steroids (AAS). However no controlled study, to our knowledge, has assessed history of tendon rupture in a large cohort of AAS users and comparison nonusers. Hypothesis We hypothesized that men reporting long-term AAS abuse would report an elevated lifetime incidence of tendon rupture as compared to non-AAS-using bodybuilders. Study Design Cross-sectional cohort study. Methods We obtained medical histories from 142 experienced male bodybuilders age 35–55, recruited in the course of two studies. Of these men, 88 reported at least two years of cumulative lifetime AAS use and 54 reported no history of AAS use. In men reporting a history of tendon rupture, we recorded circumstances of the injury, prodromal symptoms, concomitant drug or alcohol use, and details of current and lifetime AAS use if applicable. We also obtained surgical records for most participants. Results Nineteen (22%) of the AAS users, but only 3 (6%) of the nonusers reported at least one lifetime tendon rupture. The hazard ratio (95% confidence interval) for a first ruptured tendon in AAS users versus nonusers was 9.0 (2.5, 32.3); P <.001. Several men reported two or more independent lifetime tendon ruptures. Interestingly, upper body tendon ruptures occurred exclusively in the AAS group (15 [17%] of the AAS users versus 0 non-users; risk difference 0.17 (0.09, 0.25); P < 0.001 [hazard ratio not estimable]), whereas we found no significant difference between users and nonusers in risk for lower body ruptures (6 [7%] AAS users, 3 [6%] nonusers; hazard ratio 3.1 (0.7, 13.8), P = 0.13). Of 31 individual tendon ruptures that we assessed, only 6 (19%) occurred while weightlifting, with the majority occurring during other sports activities. Eight (26%) ruptures followed prodromal symptoms of nonspecific pain in the region. Virtually all ruptures were treated surgically with complete or near-complete ultimate restoration of function. Conclusions AAS abusers, as compared to otherwise similar bodybuilders, showed a markedly increased risk of tendon ruptures, particularly upper body tendon rupture. Clinical relevance Tendon rupture represents a major adverse consequence of AAS abuse and a substantial public health problem. PMID:26362436

Uterine rupture disguised by urinary retention following a second trimester induced abortion: a case report.

PubMed

Jiang, Qiaoying; Yang, Liwei; Ashley, Charles; Medlin, Erin E; Kushner, David M; Zheng, Yanmei

2015-01-22

Uterine rupture classically presents with severe abdominal pain, loss of fetal station, vaginal bleeding, and shock. We present a case of uterine rupture presenting as significant urinary retention that occurred following a second trimester abortion induced with mifepristone and misoprostol. Uterine rupture was discovered unexpectedly on diagnostic laparoscopy. The uterine rupture was contained by dense adhesions between the omentum and bladder with the previous uterine cesarean hysterotomy scar. This case highlights the difficulties in diagnosis of abnormal placentation and an unusual presentation of uterine rupture. This case was managed successfully laparoscopically.

An Analysis of Surgical Treatment for the Spontaneous Rupture of Hepatocellular Carcinoma.

PubMed

Sada, Haruki; Ohira, Masahiro; Kobayashi, Tsuyoshi; Tashiro, Hirotaka; Chayama, Kazuaki; Ohdan, Hideki

2016-01-01

The prognosis of spontaneous rupture of hepatocellular carcinoma (HCC) remains unclear. We investigated the prognosis of patients with ruptured HCC based on the treatments and prognostic factors associated with long-term survival. The prognoses of 64 consecutive patients treated for ruptured HCC from 1986 to 2013 were analyzed according to their methods of treatment. The prognostic factors of 16 surgical patients were identified, and their overall survival (OS) and recurrence rates were compared to 1,157 surgical patients who underwent surgery for non-ruptured HCC. The surgical outcomes were also compared using a propensity score matching method. Surgery was associated with a better OS. Curative resection was the only independent prognostic factor in surgical patients with ruptured HCC (p = 0.040). Although the OS of surgical patients with non-ruptured HCC was found to be significantly better than that of the patients with ruptured HCC, no significant difference in OS was observed after propensity score matching. A curative resection should be the objective of treatment, assuming the suitability of the patient's clinical condition. When the liver function reserve and tumor extension of patients with ruptured and non-ruptured HCC are similar, then their surgical outcomes may not be significantly different. © 2015 S. Karger AG, Basel.

Risk factors affecting chronic rupture of the plantar fascia.

PubMed

Lee, Ho Seong; Choi, Young Rak; Kim, Sang Woo; Lee, Jin Yong; Seo, Jeong Ho; Jeong, Jae Jung

2014-03-01

Prior to 1994, plantar fascia ruptures were considered as an acute injury that occurred primarily in athletes. However, plantar fascia ruptures have recently been reported in the setting of preexisting plantar fasciitis. We analyzed risk factors causing plantar fascia rupture in the presence of preexisting plantar fasciitis. We retrospectively reviewed 286 patients with plantar fasciitis who were referred from private clinics between March 2004 and February 2008. Patients were divided into those with or without a plantar fascia rupture. There were 35 patients in the rupture group and 251 in the nonrupture group. The clinical characteristics and risk factors for plantar fascia rupture were compared between the 2 groups. We compared age, gender, the affected site, visual analog scale pain score, previous treatment regimen, body mass index, degree of ankle dorsiflexion, the use of steroid injections, the extent of activity, calcaneal pitch angle, the presence of a calcaneal spur, and heel alignment between the 2 groups. Of the assessed risk factors, only steroid injection was associated with the occurrence of a plantar fascia rupture. Among the 35 patients with a rupture, 33 had received steroid injections. The odds ratio of steroid injection was 33. Steroid injections for plantar fasciitis should be cautiously administered because of the higher risk for plantar fascia rupture. Level III, retrospective comparative study.

Primary surface rupture associated with the Mw 7.1 16 October 1999 Hector Mine earthquake, San Bernardino County, California

USGS Publications Warehouse

Treiman, J.A.; Kendrick, K.J.; Bryant, W.A.; Rockwell, T.K.; McGill, S.F.

2002-01-01

The Mw 7.1 Hector Mine earthquake occurred within the Mojave Desert portion of the eastern California shear zone and was accompanied by 48 km of dextral surface rupture. Complex northward rupture began on two branches of the Lavic Lake fault in the northern Bullion Mountains and also propagated southward onto the Bullion fault. Lesser amounts of rupture occurred across two right steps to the south. Surface rupture was mapped using postearthquake, 1:10,000-scale aerial photography. Field mapping provided additional detail and more than 400 fault-rupture observations; of these, approximately 300 measurements were used to characterize the slip distribution. En echelon surface rupture predominated in areas of thick alluvium, whereas in the bedrock areas, rupture was more continuous and focused within a narrower zone. Measured dextral offsets were relatively symmetrical about the epicentral region, with a maximum displacement of 5.25 ?? 0.85 m. Vertical slip was a secondary component and was variable, with minor west-side-down displacements predominat.ing in the Bullion Mountains. Field and aerial photographic evidence indicates that most of the faults that ruptured in 1999 had had prior late-Quaternary displacement, although only limited sections of the rupture show evidence for prior Holocene displacement.

Imprint of Rupture Directivity From Ground Motions of the 24 August 2016 Mw6.2 Central Italy Earthquake

NASA Astrophysics Data System (ADS)

Ren, Yefei; Wang, Hongwei; Wen, Ruizhi

2017-12-01

An Mw6.2 earthquake occurred in Central Italy on 24 August 2016. The objective of this study was to reveal the imprint of rupture directivity using the strong motion recordings. The strong motion stations were separated into two groups: southeast (SE) and northwest (NW). The effects of rupture directivity on the peak ground acceleration (PGA), peak ground velocity (PGV), and pseudo spectral acceleration (PSA) were investigated. The observed values of these parameters were compared with predicted values derived from ground motion prediction equations. The results showed that the residuals between the observed and predicted PGAs, PGVs, and PSAs at periods of T < 1 s were correlated significantly with azimuth angle and generally larger in the NW sector, reflecting that the observed PGAs, PGVs, and short-period PSAs in the NW sector were generally larger than observed in the SE sector. These phenomena are accordant with the theoretical law that the rupture directivity causes higher amplitudes in the forward direction compared with the backward direction. Finally, selected source rupture parameters were inverted using PGAs and PGVs. This revealed that the rupture was predominantly unilateral rupture, the major rupture was likely at an azimuth of 360°, and the length of the major rupture was proportional to 70%-100% of the total ruptured fault, confirming that rupture directivity caused the differences in the ground motions observed in the SE and NW sectors.

Interfacial thin films rupture and self-similarity

NASA Astrophysics Data System (ADS)

Ward, Margaret H.

2011-06-01

Two superposed thin layers of fluids are prone to interfacial instabilities due to London-van der Waals forces. Evolution equations for the film thicknesses are derived using lubrication theory. Using the intrinsic scales, for a single layer, results in a system with parametric dependence of four ratios of the two layers: surface tension, Hamaker constant, viscosity, and film thickness. In contrast to the single layer case, the bilayer system has two unstable eigenmodes: squeezing and bending. For some particular parameter regimes, the system exhibits the avoided crossing behavior, where the two eigenmodes are interchanged. Based on numerical analysis, the system evolves into four different rupture states: basal layer rupture, upper layer rupture, double layer rupture, and mixed layer rupture. The ratio of Hamaker constants and the relative film thickness of the two layers control the system dynamics. Remarkably, the line of avoided crossing demarks the transition region of mode mixing and energy transfer, affecting the scaling of the dynamical regime map consequentially. Asymptotic and numerical analyses are used to examine the self-similar ruptures and to extract the power law scalings for both the basal layer rupture and the upper layer rupture. The scaling laws for the basal layer rupture are the same as those of the single layer on top of a substrate. The scaling laws for the upper layer rupture are different: the lateral length scale decreases according to (tr-t)1/3 and the film thickness decreases according to (tr-t)1/6.

Blood flow characteristics in a terminal basilar tip aneurysm prior to its fatal rupture

PubMed Central

Sforza, D.M.; Putman, C.M.; Scrivano, E.; Lylyk, P.; Cebral, J.R.

2010-01-01

Background and Purpose The development and validation of methods to stratify the risk of rupture of cerebral aneurysms is highly desired since current treatment risks can exceed the natural risk of rupture. Because unruptured aneurysms are typically treated before they rupture, it is very difficult to connect the proposed risk indices to the rupture of an individual aneurysm. The purpose of this case study was to analyze the hemodynamic environment of a saccular aneurysm of the terminal morphology sub-type that was imaged just prior to its rupture and to test whether the hemodynamic characteristics would designate this particular aneurysm as at high risk. Methods A patient-specific computational fluid dynamics model was constructed from 3D rotational angiography images acquired just hours before the aneurysm ruptured. A pulsatile flow calculation was performed and hemodynamic characteristics previously connected to rupture were analyzed. Results It was found that the aneurysm had a concentrated inflow stream, small impingement region, complex intra-aneurysmal flow structure, asymmetric flow split from the parent vessel to the aneurysm and daughter branches, and high levels of aneurysmal wall shear stress near the impaction zone. Conclusions The hemodynamics characteristics observed in this aneurysm right before its rupture are consistent with previous studies correlating aneurysm rupture and hemodynamic patterns in saccular and terminal aneurysms. This study supports the notion that hemodynamic information may be used to help stratify the rupture risk of cerebral aneurysms. PMID:20150312

7 CFR 29.3652 - Scrap (S Group).

Code of Federal Regulations, 2010 CFR

2010-01-01

... 7 Agriculture 2 2010-01-01 2010-01-01 false Scrap (S Group). 29.3652 Section 29.3652 Agriculture... INSPECTION Standards Grades § 29.3652 Scrap (S Group). A byproduct of stemmed and unstemmed tobacco. Scrap... stemmeries. Grades Grade name and specifications S Scrap. Loose, tangled, whole, or broken unstemmed leaves...

7 CFR 29.2666 - Scrap (S Group).

Code of Federal Regulations, 2010 CFR

2010-01-01

... 7 Agriculture 2 2010-01-01 2010-01-01 false Scrap (S Group). 29.2666 Section 29.2666 Agriculture... INSPECTION Standards Grades § 29.2666 Scrap (S Group). A byproduct of unstemmed and stemmed tobacco. Scrap... stemmeries. Grades Grade names and specifications S Scrap. Tangled, whole, or broken unstemmed leaves, or the...

Pedagogy Meets Digital Media: A Tangle of Teachers, Strategies, and Tactics

ERIC Educational Resources Information Center

Rust, Julie

2017-01-01

Although increasingly encouraged to incorporate digital media into classrooms to prepare students for engaged participation in a digital world, teachers are often taken by surprise when paradigm clashes arise between traditional school expectations and the affordances of these new spaces. Through data gathered from ethnographic methodologies…

Does the dye Aquashade reduce pond production of sunshine bass fingerlings?

USDA-ARS?s Scientific Manuscript database

Rooted macrophytes make harvesting fingerling sunshine bass Morone chrysops × M. saxatilis difficult because they tangle in the seines and increase fish stress. Aquashade(c), a dye, is used to reduce macrophyte growth. Fingerling culturists are reluctant to use it because it may reduce phytoplank...

A Tangled Path: Negotiating Leadership for, in, of, and with Diverse Communities

ERIC Educational Resources Information Center

Goddard, J. Tim

2015-01-01

This article addresses issues of educational leadership in postcolonial and post-conflict environments. The focus relates to large-scale testing protocols, diversity in schools, asset-based community development, and communications technology. The article highlights the importance of context to the tenets of social justice, equitable human…

Approaching messy problems: strategies for environmental analysis

Treesearch

L. M. Reid; R. R. Ziemer; T. E. Lisle

1996-01-01

Environmental problems are never neatly defined. Instead, each is a tangle of interacting processes whose manifestation and interpretation are warped by the vagaries of time, weather, expectation, and economics. Each problem involves livelihoods, values, and numerous specialized disciplines. Nevertheless, federal agencies in the Pacific Northwest have been given the...

Money, Policy Tangled in Wisconsin Labor Feud

ERIC Educational Resources Information Center

Cavanagh, Sean

2011-01-01

Gov. Scott Walker's sweeping proposal to scale back collective bargaining rights for most public employees in Wisconsin has sparked a rancorous standoff with teachers across the state--and fueled speculation about whether similar plans will gain traction in other parts of the country. But as massive demonstrations played out in Madison--an…

Somewhere over the Verde Rainbow

ERIC Educational Resources Information Center

Ekart, Donna F.

2008-01-01

When the electronic resource management system (ERM) at Kansas State University Libraries suffered a horrible data loss, the "contract db" presented a challenge for the librarians responsible for electronic resources. It was a decent data repository, but it had no ability to manage the tangled process of licensing, acquiring, activating,…

Untangling the Tangled Webs We Weave: A Team Approach to Cyberspace.

ERIC Educational Resources Information Center

Broidy, Ellen; And Others

Working in a cooperative team environment across libraries and job classifications, librarians and support staff at the University of California at Irvine (UCI) have mounted several successful web projects, including two versions of the Libraries' home page, a virtual reference collection, and Science Library "ANTswer Machine." UCI's…

More Needed for Coherent System

ERIC Educational Resources Information Center

Field, John

2004-01-01

From a learner's standpoint, Scotland's education system often looks less like a neat set of pathways than a tangled jungle. Since devolution, Scottish policymakers and the education community have set out to create a coherent and transparent set of opportunities for adult learners, of a quality to match Scotland's oft-praised unified system of…

Moving toward a Coherent School Finance System

ERIC Educational Resources Information Center

Rose, Heather

2013-01-01

California's current school finance system is a tangled web of funding programs, restrictions, inequities and confusion. Building a stronger finance system to benefit from resources is an important step in strengthening California's K-12 education system and better meeting the needs of its students. Gov. Brown has recently proposed the Local…

7 CFR 29.3526 - Leaf scrap.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 7 Agriculture 2 2014-01-01 2014-01-01 false Leaf scrap. 29.3526 Section 29.3526 Agriculture... Type 95) § 29.3526 Leaf scrap. A byproduct of unstemmed tobacco Leaf scrap results from handling unstemmed tobacco and consists of loose and tangled whole or broken leaves. [30 FR 9207, July 23, 1965...

7 CFR 29.3526 - Leaf scrap.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 7 Agriculture 2 2013-01-01 2013-01-01 false Leaf scrap. 29.3526 Section 29.3526 Agriculture... Type 95) § 29.3526 Leaf scrap. A byproduct of unstemmed tobacco Leaf scrap results from handling unstemmed tobacco and consists of loose and tangled whole or broken leaves. [30 FR 9207, July 23, 1965...

7 CFR 29.3526 - Leaf scrap.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 7 Agriculture 2 2010-01-01 2010-01-01 false Leaf scrap. 29.3526 Section 29.3526 Agriculture... Type 95) § 29.3526 Leaf scrap. A byproduct of unstemmed tobacco Leaf scrap results from handling unstemmed tobacco and consists of loose and tangled whole or broken leaves. [30 FR 9207, July 23, 1965...

7 CFR 29.3034 - Leaf scrap.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 7 Agriculture 2 2012-01-01 2012-01-01 false Leaf scrap. 29.3034 Section 29.3034 Agriculture... Leaf scrap. A by-product of unstemmed tobacco. Leaf scrap results from handling unstemmed tobacco and consists of loose and tangled whole or broken leaves. [24 FR 8771, Oct. 29, 1959. Redesignated at 49 FR...

7 CFR 29.3034 - Leaf scrap.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 7 Agriculture 2 2014-01-01 2014-01-01 false Leaf scrap. 29.3034 Section 29.3034 Agriculture... Leaf scrap. A by-product of unstemmed tobacco. Leaf scrap results from handling unstemmed tobacco and consists of loose and tangled whole or broken leaves. [24 FR 8771, Oct. 29, 1959. Redesignated at 49 FR...

7 CFR 29.3526 - Leaf scrap.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 7 Agriculture 2 2011-01-01 2011-01-01 false Leaf scrap. 29.3526 Section 29.3526 Agriculture... Type 95) § 29.3526 Leaf scrap. A byproduct of unstemmed tobacco Leaf scrap results from handling unstemmed tobacco and consists of loose and tangled whole or broken leaves. [30 FR 9207, July 23, 1965...

7 CFR 29.3034 - Leaf scrap.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 7 Agriculture 2 2013-01-01 2013-01-01 false Leaf scrap. 29.3034 Section 29.3034 Agriculture... Leaf scrap. A by-product of unstemmed tobacco. Leaf scrap results from handling unstemmed tobacco and consists of loose and tangled whole or broken leaves. [24 FR 8771, Oct. 29, 1959. Redesignated at 49 FR...

7 CFR 29.3034 - Leaf scrap.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 7 Agriculture 2 2011-01-01 2011-01-01 false Leaf scrap. 29.3034 Section 29.3034 Agriculture... Leaf scrap. A by-product of unstemmed tobacco. Leaf scrap results from handling unstemmed tobacco and consists of loose and tangled whole or broken leaves. [24 FR 8771, Oct. 29, 1959. Redesignated at 49 FR...

7 CFR 29.3034 - Leaf scrap.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 7 Agriculture 2 2010-01-01 2010-01-01 false Leaf scrap. 29.3034 Section 29.3034 Agriculture... Leaf scrap. A by-product of unstemmed tobacco. Leaf scrap results from handling unstemmed tobacco and consists of loose and tangled whole or broken leaves. [24 FR 8771, Oct. 29, 1959. Redesignated at 49 FR...

7 CFR 29.3526 - Leaf scrap.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 7 Agriculture 2 2012-01-01 2012-01-01 false Leaf scrap. 29.3526 Section 29.3526 Agriculture... Type 95) § 29.3526 Leaf scrap. A byproduct of unstemmed tobacco Leaf scrap results from handling unstemmed tobacco and consists of loose and tangled whole or broken leaves. [30 FR 9207, July 23, 1965...

PrEP Whores and HIV Prevention: The Queer Communication of HIV Pre-Exposure Prophylaxis (PrEP).

PubMed

Spieldenner, Andrew

2016-12-01

HIV pre-exposure prophylaxis (PrEP) has been introduced as another biomedical tool in HIV prevention. Whereas other such tools-including post-exposure prophylaxis (PEP) and interruption of perinatal transmission-have been embraced by those impacted by HIV, PrEP has been met with more conflict, especially within the gay community and HIV organizations. The "PrEP whore" has come to designate the social value and personal practices of those taking PrEP. This study examines the "PrEP whore" discourse by using queer theory and quare theory. Within these theoretical vantage points, the study explicates four discursive areas: slut shaming, dirty/clean binaries, mourning the loss of condoms, and reclaiming the inner whore. The study illuminates possible discursive strategies that lie outside of the domains of public health and within the individual and community.

Feedback informed treatment: evidence-based practice meets social construction.

PubMed

Tilsen, Julie; McNamee, Sheila

2015-03-01

This article explores the challenges presented by the mandate for evidence-based practice for family therapists who identify with the philosophical stance of social construction. The history of psychotherapy outcome research is reviewed, as are current findings that provide empirical evidence for an engaged, dialogic practice. The authors suggest that the binary between empiricism and social construction may be unhinged by understanding empiricism as a particular discursive frame (i.e., a particular way of talking, acting, and being in the world), one of many available as a way of understanding and talking about our work. Through a case vignette, the authors introduce the evidence-based practice of Feedback Informed Treatment as an elaboration of social construction, and as an example of bridging the gap between the discursive frames of empiricism and social construction. © 2014 Family Process Institute.

The air's got to be far cleaner here: a discursive analysis of place-identity threat.

PubMed

Hugh-Jones, Siobhan; Madill, Anna

2009-12-01

That talk is never disinterested complicates the relationship between the environment and the claims people make about it. Talk about place, and one's self in it, is particularly complex when the environment poses risk or is otherwise problematized. This study, a secondary analysis of interview data, seeks to extend discursive work on place-identity by examining the ways in which 14 residents of a small English village talk about themselves and their locale. The locale accommodates an active quarry, and many residents had lodged complaints to the quarry about dust, noise and vibrations from blasting. Attention to the interactional context of the interviews illustrates the ways in which (simply) interviewing people about their locale can threaten self- and place-identity. When asked about life in the village, interviewees oriented to two main dilemmas in protecting self- and place-identity: (1) how to justify continued residence in a challenging environment and (2) how to complain about the locale whilst maintaining positive place-identity. Discursive responses to these dilemmas drew upon typical identity processes, such as self- and place distinctiveness and the formulation of out-groups, as well as upon constructions of localized power-sharing and morally obligated tolerance of risk. We suggest that research on problematical places, and of environmental risk, needs to be sensitized to how it may constitute a threat to self- and place-identity, and how this may mediate formulations self and place, as well as of environmental risk.

Discursive construction of polyphony in healthcare management.

PubMed

Hujala, Anneli; Rissanen, Sari

2012-01-01

The aim of the paper is to understand and define how the polyphony of management is constructed in interaction and to describe this through concrete management meeting cases. Polyphony refers to the diverse voices of various organization members, and how these voices are present, disclosed and utilized in management. The study is based on the social constructionist and discursive perspectives of management, which question the traditional, individualistic approaches of management. The issue was examined through a qualitative case study by analysing the micro-level management discourse in three healthcare organizations. Discursive practices that enhance or inhibit polyphony are often unnoticed and unconscious. Key moments of management discourse are an example of unconscious mundane practices through which members of organizations construct the reality of management. The empirical results are locally contextual. In the future, research will be able to apply the approach to diverse contexts as well as link micro-level discourses to the construction of broader health and social management discourses. The paper increases the understanding of how to enhance participation and staff contribution, and how to utilize the knowledge of all members of the organization. Both managers and other staff members are fully involved in the social construction of management. Micro-level discourse should be paid attention to in management work as well as in the education of managers and staff. The study increases the understanding of micro-level issues of management and challenges the conventional, taken-for-granted assumptions behind organization and management theories.

Discursive junctions in flood risk governance - A comparative understanding in six European countries.

PubMed

Kaufmann, Maria; Wiering, Mark

2017-07-01

Flood risks are managed differently across Europe. While a number of research studies aim to understand these differences, they tend to pay little attention to the social constructionist aspects of flood risk governance, i.e. the meaning that societies give to flood risk and governance. This paper aims to address this gap by understanding differences in flood risk management approaches (FRMA) from a discursive-institutional perspective. Based on this perspective, an analytical framework was developed to systematically analyse and compare discourses pertaining to flood risk and its governance in six European member states (England (the United Kingdom), Flanders (Belgium), France, the Netherlands, Poland and Sweden). Correspondingly, this paper demonstrates how the hegemonic discursive-institutional patterns of flood risk governance differ between the six European countries. These differences may influence the capability of countries to learn from each other, adopt new FRMAs or cooperate with each other. Moreover, the paper argues that differences in discourses partially account for the differences in FRMAs between countries, combined with other factors. Additionally, broader implications are discussed. For example, the research findings imply that some discourses tend to favour or disfavour other discourses, and that they additionally also tend to favour particular FRMAs; e.g. the flood risk discourse pertaining to high manageability of risks seems to favour a governance discourse of collectivity and central governance. The different insights imply that further research is necessary to understand the complex interaction of discourses and institutional arrangements. Copyright © 2017 Elsevier Ltd. All rights reserved.

Injuries of the trachea and bronchi

PubMed Central

Bertelsen, S.; Howitz, P.

1972-01-01

Traumatic rupture of the trachea or the bronchi is reported with increasing frequency. Such rupture may follow penetrating wounds, but the common cause is blunt trauma of the throat or thorax. When the proximal trachea is damaged other cervical structures are usually involved. By contrast the distal trachea or bronchi are not infrequently the only thoracic structures damaged. In particular there may be no rib fractures, or obvious fractures may be uncomplicated and insignificant. Thoracic rupture usually occurs in the vicinity of the carina. Central rupture generally presents with emphysema of the mediastinum and neck. Diagnosis can usually be confirmed by tracheobronchoscopy. Rupture of the peripheral bronchi generally presents with pneumothorax and atelectasis. Central rupture should be treated by primary suture. Lobectomy is often necessary when small bronchi are ruptured. PMID:5034596

Induced seismicity provides insight into why earthquake ruptures stop.

PubMed

Galis, Martin; Ampuero, Jean Paul; Mai, P Martin; Cappa, Frédéric

2017-12-01

Injection-induced earthquakes pose a serious seismic hazard but also offer an opportunity to gain insight into earthquake physics. Currently used models relating the maximum magnitude of injection-induced earthquakes to injection parameters do not incorporate rupture physics. We develop theoretical estimates, validated by simulations, of the size of ruptures induced by localized pore-pressure perturbations and propagating on prestressed faults. Our model accounts for ruptures growing beyond the perturbed area and distinguishes self-arrested from runaway ruptures. We develop a theoretical scaling relation between the largest magnitude of self-arrested earthquakes and the injected volume and find it consistent with observed maximum magnitudes of injection-induced earthquakes over a broad range of injected volumes, suggesting that, although runaway ruptures are possible, most injection-induced events so far have been self-arrested ruptures.

Genome-wide association analysis in dogs implicates 99 loci as risk variants for anterior cruciate ligament rupture

PubMed Central

Baker, Lauren A.; Kirkpatrick, Brian; Rosa, Guilherme J. M.; Gianola, Daniel; Valente, Bruno; Sumner, Julia P.; Baltzer, Wendy; Hao, Zhengling; Binversie, Emily E.; Volstad, Nicola; Piazza, Alexander; Sample, Susannah J.

2017-01-01

Anterior cruciate ligament (ACL) rupture is a common condition that can be devastating and life changing, particularly in young adults. A non-contact mechanism is typical. Second ACL ruptures through rupture of the contralateral ACL or rupture of a graft repair is also common. Risk of rupture is increased in females. ACL rupture is also common in dogs. Disease prevalence exceeds 5% in several dog breeds, ~100 fold higher than human beings. We provide insight into the genetic etiology of ACL rupture by genome-wide association study (GWAS) in a high-risk breed using 98 case and 139 control Labrador Retrievers. We identified 129 single nucleotide polymorphisms (SNPs) within 99 risk loci. Associated loci (P<5E-04) explained approximately half of phenotypic variance in the ACL rupture trait. Two of these loci were located in uncharacterized or non-coding regions of the genome. A chromosome 24 locus containing nine genes with diverse functions met genome-wide significance (P = 3.63E-0.6). GWAS pathways were enriched for c-type lectins, a gene set that includes aggrecan, a gene set encoding antimicrobial proteins, and a gene set encoding membrane transport proteins with a variety of physiological functions. Genotypic risk estimated for each dog based on the risk contributed by each GWAS locus showed clear separation of ACL rupture cases and controls. Power analysis of the GWAS data set estimated that ~172 loci explain the genetic contribution to ACL rupture in the Labrador Retriever. Heritability was estimated at 0.48. We conclude ACL rupture is a moderately heritable highly polygenic complex trait. Our results implicate c-type lectin pathways in ACL homeostasis. PMID:28379989

Spontaneous rupture of ovarian cystadenocarcinoma: pre- and post-rupture computed tomography evaluation*

PubMed Central

Salvadori, Priscila Silveira; Bomfim, Lucas Novais; von Atzingen, Augusto Castelli; D’Ippolito, Giuseppe

2015-01-01

Epithelial ovarian tumors are the most common malignant ovarian neoplasms and, in most cases, eventual rupture of such tumors is associated with a surgical procedure. The authors report the case of a 54-year-old woman who presented with spontaneous rupture of ovarian cystadenocarcinoma documented by computed tomography, both before and after the event. In such cases, a post-rupture staging tends to be less favorable, compromising the prognosis. PMID:26543286

Kinetics of the Multistep Rupture of Fibrin ‘A-a’ Polymerization Interactions Measured Using Atomic Force Microscopy

PubMed Central

Averett, Laurel E.; Schoenfisch, Mark H.; Akhremitchev, Boris B.; Gorkun, Oleg V.

2009-01-01

Abstract Fibrin, the structural scaffold of blood clots, spontaneously polymerizes through the formation of ‘A-a’ knob-hole bonds. When subjected to external force, the dissociation of this bond is accompanied by two to four abrupt changes in molecular dimension observable as rupture events in a force curve. Herein, the configuration, molecular extension, and kinetic parameters of each rupture event are examined. The increases in contour length indicate that the D region of fibrinogen can lengthen by ∼50% of the length of a fibrin monomer before rupture of the ‘A-a’ interaction. The dependence of the dissociation rate on applied force was obtained using probability distributions of rupture forces collected at different pull-off velocities. These distributions were fit using a model in which the effects of the shape of the binding potential are used to quantify the kinetic parameters of forced dissociation. We found that the weak initial rupture (i.e., event 1) was not well approximated by these models. The ruptured bonds comprising the strongest ruptures, events 2 and 3, had kinetic parameters similar to those commonly found for the mechanical unfolding of globular proteins. The bonds ruptured in event 4 were well described by these analyses, but were more loosely bound than the bonds in events 2 and 3. We propose that the first event represents the rupture of an unknown interaction parallel to the ‘A-a’ bond, events 2 and 3 represent unfolding of structures in the D region of fibrinogen, and event 4 is the rupture of the ‘A-a’ knob-hole bond weakened by prior structural unfolding. Comparison of the activation energy obtained via force spectroscopy measurements with the thermodynamic free energy of ‘A-a’ bond dissociation indicates that the ‘A-a’ bond may be more resistant to rupture by applied force than to rupture by thermal dissociation. PMID:19917237

Definitive diagnosis of breast implant rupture using magnetic resonance imaging.

PubMed

Ahn, C Y; Shaw, W W; Narayanan, K; Gorczyca, D P; Sinha, S; Debruhl, N D; Bassett, L W

1993-09-01

Breast implant rupture is an important complication of augmented and reconstructed breasts. Although several techniques such as mammography, xeromammography, ultrasound, thermography, and computed tomographic (CT) scanning have been proven to be useful to detect implant rupture, they have several disadvantages and lack specificity. In the current study, we have established magnetic resonance imaging (MRI) as a definitive, reliable, and reproducible technique to diagnose both intracapsular and extracapsular ruptures. The study was conducted in 100 symptomatic patients. Our imaging parameters were able to identify ruptures in implants with silicone shells. All the ruptures showed the presence of wavy lines, free-floating silicone shell within the gel ("free-floating loose-thread sign" or "linguine sign"). We had a 3.75 percent incidence of false-positive and false-negative results. The sensitivity for detection of silicone implant rupture was 76 percent, with a specificity of 97 percent. In addition, we also were able to identify the artifacts that may interfere with the definitive diagnosis of implant rupture.

Comparing slow and fast rupture in laboratory experiments

NASA Astrophysics Data System (ADS)

Aben, F. M.; Brantut, N.; David, E.; Mitchell, T. M.

2017-12-01

During the brittle failure of rock, elastically stored energy is converted into a localized fracture plane and surrounding fracture damage, seismic radiation, and thermal energy. However, the partitioning of energy might vary with the rate of elastic energy release during failure. Here, we present the results of controlled (slow) and dynamic (fast) rupture experiments on dry Lanhélin granite and Westerly granite samples, performed under triaxial stress conditions at confining pressures of 50 and 100 MPa. During the tests, we measured sample shortening, axial load and local strains (with 2 pairs of strain gauges glued directly onto the sample). In addition, acoustic emissions (AEs) and changes in seismic velocities were monitored. The AE rate was used as an indicator to manually control the axial load on the sample to stabilize rupture in the quasi-static failure experiments. For the dynamic rupture experiments a constant strain rate of 10-5 s-1 was applied until sample failure. A third experiment, labeled semi-controlled rupture, involved controlled rupture up to a point where the rupture became unstable and the remaining elastic energy was released dynamically. All experiments were concluded after a macroscopic fracture had developed across the whole sample and frictional sliding commenced. Post-mortem samples were epoxied, cut and polished to reveal the macroscopic fracture and the surrounding damage zone. The samples failed with average rupture velocities varying from 5x10-6 m/s up to >> 0.1 m/s. The analyses of AE locations on the slow ruptures reveal that within Westerly granite samples - with a smaller grain size - fracture planes are disbanded in favor of other planes when a geometrical irregularity is encountered. For the coarser grained Lanhélin granite a single fracture plane is always formed, although irregularities are recognized as well. The semi-controlled experiments show that for both rock types the rupture can become unstable in response to these irregularities. In Westerly granite, slow rupture experiments tend to produce complex fracture patterns while during the dynamic rupture experiments secondary rupture planes are not formed. These findings show that grain or flaw size, flaw distribution, and rupture speed strongly influence fracture localization and propagation.

Simultaneous bilateral Achilles tendon ruptures associated with statin medication despite regular rock climbing exercise.

PubMed

Carmont, Michael R; Highland, Adrian M; Blundell, Christopher M; Davies, Mark B

2009-11-01

Ruptures of the Achilles tendon are common however simultaneous ruptures occur less frequently. Eccentric loading exercise programmes have been used to successfully treat Achilles tendinopathy. We report a case of simultaneous bilateral Achilles tendon rupture in a patient predisposed to rupture due to longstanding raised serum lipoprotein and recently introduced therapeutic statin medication. The patient was also a keen rock climber and had regularly undertaken loading exercise. This case illustrates that the therapeutic effect of mixed loading exercises for the Achilles tendon may not be adequate to overcome the predisposition to rupture caused by hyperlipidaemia and statin medication.

Fractal avalanche ruptures in biological membranes

NASA Astrophysics Data System (ADS)

Gözen, Irep; Dommersnes, Paul; Czolkos, Ilja; Jesorka, Aldo; Lobovkina, Tatsiana; Orwar, Owe

2010-11-01

Bilayer membranes envelope cells as well as organelles, and constitute the most ubiquitous biological material found in all branches of the phylogenetic tree. Cell membrane rupture is an important biological process, and substantial rupture rates are found in skeletal and cardiac muscle cells under a mechanical load. Rupture can also be induced by processes such as cell death, and active cell membrane repair mechanisms are essential to preserve cell integrity. Pore formation in cell membranes is also at the heart of many biomedical applications such as in drug, gene and short interfering RNA delivery. Membrane rupture dynamics has been studied in bilayer vesicles under tensile stress, which consistently produce circular pores. We observed very different rupture mechanics in bilayer membranes spreading on solid supports: in one instance fingering instabilities were seen resulting in floral-like pores and in another, the rupture proceeded in a series of rapid avalanches causing fractal membrane fragmentation. The intermittent character of rupture evolution and the broad distribution in avalanche sizes is consistent with crackling-noise dynamics. Such noisy dynamics appear in fracture of solid disordered materials, in dislocation avalanches in plastic deformations and domain wall magnetization avalanches. We also observed similar fractal rupture mechanics in spreading cell membranes.

[Spontaneous splenic rupture due to infectious acute mononucleosis: case report].

PubMed

Greco, L; De Gennaro, E; Degara, A; Papa, U

2003-01-01

Infectious mononucleosis is an acute, viral, illness associated with a high incidence of splenomegaly. Spontaneous splenic rupture is a rare but life-threatening complication of infectious mononucleosis. The authors report the case of a 19-year-old patient with an infectious mononucleosis causing a spontaneous splenic rupture. When rupture occurs the mortality has been significant. The spleen may be vulnerable for the histopathologic changes that occur as a result of this illness. Two thirds of patients with infectious mononucleosis develop an enlarged spleen, but in only 0.5% of all patients will it rupture. Abdominal pain and tachycardia are unusual in uncomplicated infectious mononucleosis and should alert a doctor to the possibility of spontaneous splenic rupture. The diagnosis of splenic rupture may be confirmed in a variety of ways. In this patient ultrasound and Rutkow's criteria may aid in establishing the diagnosis. In patients with infectious mononucleosis suspected of having rupture of the spleen, a rapid but thorough assessment and prompt implementation of appropriate management should minimize the associated morbidity and mortality. On the basis of review of the medical literature and of our own experience, we advocate emergent splenectomy for spontaneous splenic rupture in patients with infectious mononucleosis.

Morphological and Hemodynamic Discriminators for Rupture Status in Posterior Communicating Artery Aneurysms

PubMed Central

Karmonik, Christof; Fang, Yibin; Xu, Jinyu; Yu, Ying; Cao, Wei; Liu, Jianmin; Huang, Qinghai

2016-01-01

Background and Purpose The conflicting findings of previous morphological and hemodynamic studies on intracranial aneurysm rupture may be caused by the relatively small sample sizes and the variation in location of the patient-specific aneurysm models. We aimed to determine the discriminators for aneurysm rupture status by focusing on only posterior communicating artery (PCoA) aneurysms. Materials and Methods In 129 PCoA aneurysms (85 ruptured, 44 unruptured), clinical, morphological and hemodynamic characteristics were compared between the ruptured and unruptured cases. Multivariate logistic regression analysis was performed to determine the discriminators for rupture status of PCoA aneurysms. Results While univariate analyses showed that the size of aneurysm dome, aspect ratio (AR), size ratio (SR), dome-to-neck ratio (DN), inflow angle (IA), normalized wall shear stress (NWSS) and percentage of low wall shear stress area (LSA) were significantly associated with PCoA aneurysm rupture status. With multivariate analyses, significance was only retained for higher IA (OR = 1.539, p < 0.001) and LSA (OR = 1.393, p = 0.041). Conclusions Hemodynamics and morphology were related to rupture status of intracranial aneurysms. Higher IA and LSA were identified as discriminators for rupture status of PCoA aneurysms. PMID:26910518

Morphological and Hemodynamic Discriminators for Rupture Status in Posterior Communicating Artery Aneurysms.

PubMed

Lv, Nan; Wang, Chi; Karmonik, Christof; Fang, Yibin; Xu, Jinyu; Yu, Ying; Cao, Wei; Liu, Jianmin; Huang, Qinghai

2016-01-01

The conflicting findings of previous morphological and hemodynamic studies on intracranial aneurysm rupture may be caused by the relatively small sample sizes and the variation in location of the patient-specific aneurysm models. We aimed to determine the discriminators for aneurysm rupture status by focusing on only posterior communicating artery (PCoA) aneurysms. In 129 PCoA aneurysms (85 ruptured, 44 unruptured), clinical, morphological and hemodynamic characteristics were compared between the ruptured and unruptured cases. Multivariate logistic regression analysis was performed to determine the discriminators for rupture status of PCoA aneurysms. While univariate analyses showed that the size of aneurysm dome, aspect ratio (AR), size ratio (SR), dome-to-neck ratio (DN), inflow angle (IA), normalized wall shear stress (NWSS) and percentage of low wall shear stress area (LSA) were significantly associated with PCoA aneurysm rupture status. With multivariate analyses, significance was only retained for higher IA (OR = 1.539, p < 0.001) and LSA (OR = 1.393, p = 0.041). Hemodynamics and morphology were related to rupture status of intracranial aneurysms. Higher IA and LSA were identified as discriminators for rupture status of PCoA aneurysms.

Systematic Observations of the Slip-pulse Properties of Large Earthquake Ruptures

NASA Astrophysics Data System (ADS)

Melgar, D.; Hayes, G. P.

2017-12-01

In earthquake dynamics there are two end member models of rupture: propagating cracks and self-healing pulses. These arise due to different properties of ruptures and have implications for seismic hazard; rupture mode controls near-field strong ground motions. Past studies favor the pulse-like mode of rupture, however, due to a variety of limitations, it has proven difficult to systematically establish their kinematic properties. Here we synthesize observations from a database of >150 rupture models of earthquakes spanning M7-M9 processed in a uniform manner and show the magnitude scaling properties (rise time, pulse width, and peak slip rate) of these slip pulses indicates self-similarity. Self similarity suggests a weak form of rupture determinism, where early on in the source process broader, higher amplitude slip pulses will distinguish between events of icnreasing magnitude. Indeed, we find by analyzing the moment rate functions that large and very large events are statistically distinguishable relatively early (at 15 seconds) in the rupture process. This suggests that with dense regional geophysical networks strong ground motions from a large rupture can be identified before their onset across the source region.

Influence of fault steps on rupture termination of strike-slip earthquake faults

NASA Astrophysics Data System (ADS)

Li, Zhengfang; Zhou, Bengang

2018-03-01

A statistical analysis was completed on the rupture data of 29 historical strike-slip earthquakes across the world. The purpose of this study is to examine the effects of fault steps on the rupture termination of these events. The results show good correlations between the type and length of steps with the seismic rupture and a poor correlation between the step number and seismic rupture. For different magnitude intervals, the smallest widths of the fault steps (Lt) that can terminate the rupture propagation are variable: Lt = 3 km for Ms 6.5 6.9, Lt = 4 km for Ms 7.0 7.5, Lt = 6 km for Ms 7.5 8.0, and Lt = 8 km for Ms 8.0 8.5. The dilational fault step is easier to rupture through than the compression fault step. The smallest widths of the fault step for the rupture arrest can be used as an indicator to judge the scale of the rupture termination of seismic faults. This is helpful for research on fault segmentation, as well as estimating the magnitude of potential earthquakes, and is thus of significance for the assessment of seismic risks.

Rupture directivity of microseismic events recorded during hydraulic fracture stimulations.

NASA Astrophysics Data System (ADS)

Urbancic, T.; Smith-Boughner, L.; Baig, A.; Viegas, G.

2016-12-01

We model the dynamics of a complex rupture sequence with four sub-events. These events were recorded during hydraulic fracture stimulations in a gas-bearing shale formation. With force-balance accelerometers, 4.5Hz and 15Hz instruments recording the failure history, we study the directivity of the entire rupture sequence and each sub-event. Two models are considered: unilateral and bi-lateral failures of penny shaped cracks. From the seismic moment tensors of these sub-events, we consider different potential failure planes and rupture directions. Using numerical wave-propagation codes, we generate synthetic rupture sequences with both unilateral and bi-lateral ruptures. These are compared to the four sub-events to determine the directionality of the observed failures and the sensitivity of our recording bandwidth and geometry to distinguishing between different rupture processes. The frequency of unilateral and bilateral rupture processes throughout the fracture stimulation is estimated by comparing the directivity characteristics of the modeled sub-events to other high-quality microseismic events recorded during the same stimulation program. Understanding the failure processes of these microseismic events can provide great insight into the changes in the rock mass responsible for these complex rupture processes.

Secular pattern of aneurismal rupture with the lunar cycle and season.

PubMed

Banfield, Jillian C; Abdolell, Mohamed; Shankar, Jai S

2017-02-01

Background The lunar cycle and seasons may be associated with rates of rupture of intracranial aneurysms, but the literature is mixed. Studies of the association between the lunar cycle and rates of aneurysm rupture used the eight qualitative moon phases. The purpose of this study was to assess any association of aneurysm rupture with the lunar cycle and with the season. Materials and methods We retrospectively reviewed all cases of subarachnoid haemorrhage secondary to ruptured intracranial aneurysm treated with endovascular coiling in our institution over a 10-year period. We included only cases with a known rupture date. We used the degree of illumination of the moon to quantitatively code the lunar cycle. Results A total of 212 cases were included in our analyses. The odds of aneurysm rupture were significantly greater ( p < 0.001) when the moon was least (new moon) and most (full moon) illuminated, as compared to the middle of the lunar cycle. The odds of rupture tended to be higher ( p = 0.059) in the summer, compared to autumn. Conclusions The odds of aneurysm rupture were greater when the moon was least illuminated (new moon) and most illuminated (full moon), compared to the middle of the lunar cycle.

Multi-Fault Rupture Scenarios in the Brawley Seismic Zone

NASA Astrophysics Data System (ADS)

Kyriakopoulos, C.; Oglesby, D. D.; Rockwell, T. K.; Meltzner, A. J.; Barall, M.

2017-12-01

Dynamic rupture complexity is strongly affected by both the geometric configuration of a network of faults and pre-stress conditions. Between those two, the geometric configuration is more likely to be anticipated prior to an event. An important factor in the unpredictability of the final rupture pattern of a group of faults is the time-dependent interaction between them. Dynamic rupture models provide a means to investigate this otherwise inscrutable processes. The Brawley Seismic Zone in Southern California is an area in which this approach might be important for inferring potential earthquake sizes and rupture patterns. Dynamic modeling can illuminate how the main faults in this area, the Southern San Andreas (SSAF) and Imperial faults, might interact with the intersecting cross faults, and how the cross faults may modulate rupture on the main faults. We perform 3D finite element modeling of potential earthquakes in this zone assuming an extended array of faults (Figure). Our results include a wide range of ruptures and fault behaviors depending on assumptions about nucleation location, geometric setup, pre-stress conditions, and locking depth. For example, in the majority of our models the cross faults do not strongly participate in the rupture process, giving the impression that they are not typically an aid or an obstacle to the rupture propagation. However, in some cases, particularly when rupture proceeds slowly on the main faults, the cross faults indeed can participate with significant slip, and can even cause rupture termination on one of the main faults. Furthermore, in a complex network of faults we should not preclude the possibility of a large event nucleating on a smaller fault (e.g. a cross fault) and eventually promoting rupture on the main structure. Recent examples include the 2010 Mw 7.1 Darfield (New Zealand) and Mw 7.2 El Mayor-Cucapah (Mexico) earthquakes, where rupture started on a smaller adjacent segment and later cascaded into a larger event. For that reason, we are investigating scenarios of a moderate rupture on a cross fault, and determining conditions under which the rupture will propagate onto the adjacent SSAF. Our investigation will provide fundamental insights that may help us interpret faulting behaviors in other areas, such as the complex Mw 7.8 2016 Kaikoura (New Zealand) earthquake.

Precursory, Nucleation and Propagation of Ruptures Along Heterogeneously Loaded, Circular Experimental Faults

NASA Astrophysics Data System (ADS)

Reches, Z.; Zu, X.; Jeffers, J.

2017-12-01

We explored the evolution of dynamic rupture along a circular experimental fault composed of clear acrylic blocks. The ring-shaped fault surface has inner and outer diameters of 7.72 and 10.16 cm, respectively. An array of ten rossette strain-gauges is attached to the outer rim of one block that provide the 2D strain tensor in a plane normal to the fault. The 30 components of the gauges are monitored at 10^6 samples/second. One 3D miniature accelerometer is attached to the fault block. The initial asperities of the fault surface generated a non-uniform strain (=stress) distribution that was recorded, and indicated local deviations of ±30% from the mean stress. The mean normal stress was up to 3.5 MPa, the remotely applied velocity was up to .002 m/s, and the slip velocities during rupture were not measured. The rupture characteristics, namely propagation velocity and rupture front strain-field, were determined from strain-gauge outputs. The analysis of tens of stick-slip events revealed the following preliminary results: (1) The ruptures consistently nucleated at sites of high local strains (=stresses) that were formed by the pre-shear, normal stress loading. (2) The pre-rupture nucleation process was recognized a by temporal (< 0.1 s), local (<20 mm) reduction of the shear strain. (3) Commonly, the initiation of nucleation was associated with micro acoustic emissions, whereas the initiation of rupture was associated with intense acoustic activity. (4) Nucleation could occur quasi-simultaneously at two, highly stressed sites. (5) From the nucleation site, the ruptures propagated in two directions along the ring-shaped fault, and the collision between the two fronts led to rupture `shut-off'. (5) The strain-field of rupture fronts was well-recognized for ruptures propagating faster than 50 m/s, and the fastest fronts propagated at 1000 m/s. (7) It appears that the rupture front strain-field close to the nucleation site differs from the front strain-field far from nucleation site. (8) Post-shear examination of the fault surfaces revealed evidence of brittle wear of the acrylic including gouge formation, ploughing, and powder smearing. (9) Work in progress includes attempts to achieve faster dynamic ruptures, and the utilization of the existing monitoring system to rupture granite faults.

Traumatic graft rupture after primary and revision anterior cruciate ligament reconstruction: retrospective analysis of incidence and risk factors in 2915 cases.

PubMed

Schlumberger, Michael; Schuster, Philipp; Schulz, Martin; Immendörfer, Micha; Mayer, Philipp; Bartholomä, Jochen; Richter, Jörg

2017-05-01

To determine incidence and risk factors for traumatic graft rupture following primary and revision anterior cruciate ligament (ACL) reconstruction. All cases of isolated ACL reconstructions (primary or revision) performed at our institution between January 2007 and December 2010 were included. From this group of 2467 primary reconstructions (32.4 ± 12.2 years) and 448 revision reconstructions (33.0 ± 10.4 years), we identified all patients who underwent revision ACL reconstruction following traumatic graft rupture in further course and all patients who underwent contralateral primary ACL reconstruction until January 2014. Age, gender, time from index procedure and graft diameter (for hamstring autografts) were analysed in terms of being a potential risk factor for graft rupture. Within a follow-up period of 5.0 ± 1.1 years (3.0-7.0), a total of 82 traumatic graft ruptures were identified, resulting in an incidence of 2.8 %. Seventy-three cases were seen following primary reconstructions (3.0 %), and nine cases following revision reconstructions (2.0 %), respectively (n.s.). Age younger than 25 years was identified as a risk factor for both groups (p = 0.001 and p = 0.008; odds ratio 6.0 and 6.4, respectively). In primary reconstruction, male patients had a higher risk of graft rupture compared with females (3.7 vs. 1.6 %; p = 0.005), and the first year after index procedure was associated with a higher risk of graft rupture compared with the following (p < 0.001). Graft diameter did not influence the risk of graft rupture. Incidence of contralateral ACL rupture was 3.1 %, which was not different to the incidence of graft rupture ipsilaterally (n.s.). No statistically significant differences were seen between graft rupture incidence of primary and revision ACL reconstructions. Young age (<25 years) and short time to the index procedure (especially within the first year) were confirmed as risk factors for graft rupture in both groups. Male gender was a risk factor for primary reconstructions. Graft diameter had no influence on graft rupture rates. No difference in incidence of graft rupture compared to ACL rupture on the contralateral side was apparent. Retrospective case series, Level IV.

A Three Year Clinicopathological Study of Cases of Rupture Uterus

PubMed Central

Rathod, Setu; Swain, Sujata

2015-01-01

Introduction Rupture uterus is a life threatening obstetric complication with serious maternal and fetal side-effects. We report a 3 year (2010-2013) retrospective clinical study of pregnancy with rupture uterus cases attending a tertiary care hospital. Aim The aim of the study was to evaluate the incidence of rupture uterus, incidence as per age, parity, clinical presentations, risk factors, complications and management. Materials and Methods Retrospective data of 74 cases of rupture uterus in SCB Medical college, Cuttack was collected from case records of 26,547 deliveries during a 3 year span (2010-2013). Parameters like cause of rupture, type, site of rupture and outcome were recorded. The collected data was analysed by SPSS software v19. Results Out of 26,547 deliveries during the three year period, there were 74 cases of rupture uterus with an incidence of rupture 1 in 359 (0.28%). The mean age of rupture uterus was 27.4 years. 95.8% were multigravida and majority were referred cases from low socioeconomic status. Only 40.5% had the required minimum of four antenatal visits as recommended by WHO (World Health Organisation). A total of 48.6% of cases with rupture uterus had history of previous Caesarean section. Prolonged labour was present in 75.6% of the cases. Only 12.2% of the cases had history of oxytocin use whereas 9.5% had undergone an operative vaginal delivery. Obstructed labour was the cause in 24.3% of cases, 85.1% had complete rupture. Majority had a rupture in the anterior wall (69%) and 81.1% had rupture in lower segment of uterus. Only 17.6% had broad ligament haematoma, 10.8% colporrhexis and 6.8% had associated bladder injury. Repair was possible in only 39.2% of cases, whereas majority landed up in hysterectomy. Internal iliac ligation was done in 2.7% of cases. Perinatal mortality was 90.5% whereas maternal death was seen in 13.5% cases. One patient developed VVF (vesicovaginal fistula). Duration of hospital stay was upto 14 days in 81.1% cases. Conclusion Education and proper care especially of high risk patients like previous caesarean by competent personnal, proper use of oxytocin and early referral may help to reduce the incidence of “rupture uterus”. PMID:26673858

EVALUATION OF CONTRAST-ENHANCED ULTRASONOGRAPHY AS A METHOD FOR DETECTING GALLBLADDER NECROSIS OR RUPTURE IN DOGS.

PubMed

Bargellini, Paolo; Orlandi, Riccardo; Paloni, Chiara; Rubini, Giuseppe; Fonti, Paolo; Peterson, Mark E; Rishniw, Mark; Boiti, Cristiano

2016-11-01

Gall bladder necrosis and rupture are life-threatening conditions in dogs requiring surgical intervention and early diagnosis is essential. Human patients with suspected gall bladder necrosis/rupture are commonly evaluated with contrast-enhanced ultrasonography (CEUS), however this procedure has not been described in dogs with suspected gall bladder necrosis/rupture. In a prospective diagnostic cohort study, CEUS (using SonoVue contrast medium) was performed in 93 dogs with gallbladder lesions identified by abdominal conventional ultrasonography. Necrosis/rupture was identified by CEUS as a focal lack of enhancement of the gallbladder wall. Dogs with positive CEUS finding for necrosis/rupture (complete lack of regional wall enhancement) underwent immediate surgery as did dogs with other biliary disorders requiring surgery. Dogs with negative CEUS findings or those not requiring surgery were managed medically. In cases undergoing surgery, necrosis/rupture was confirmed intraoperatively (and via histopathology). Absence of necrosis/rupture was confirmed either intraoperatively (via histopathology) or was assumed to be absent by complete recovery with medical management. Forty-nine dogs underwent surgery and cholecystectomy: 24 had necrosis/rupture. CEUS was more accurate (100% sensitive and specific) in diagnosing gallbladder wall necrosis/rupture than conventional ultrasonography (75% sensitive and 81% specific) (P < 0.03). In conclusion, CEUS provides accurate characterization of gallbladder wall integrity that can impact decisions regarding clinical management, either surgical or medical. © 2016 American College of Veterinary Radiology.

Size ratio correlates with intracranial aneurysm rupture status: a prospective study.

PubMed

Rahman, Maryam; Smietana, Janel; Hauck, Erik; Hoh, Brian; Hopkins, Nick; Siddiqui, Adnan; Levy, Elad I; Meng, Hui; Mocco, J

2010-05-01

The prediction of intracranial aneurysm (IA) rupture risk has generated significant controversy. The findings of the International Study of Unruptured Intracranial Aneurysms (ISUIA) that small anterior circulation aneurysms (<7 mm) have a 0% risk of subarachnoid hemorrhage in 5 years is difficult to reconcile with other studies that reported a significant portion of ruptured IAs are small. These discrepancies have led to the search for better aneurysm parameters to predict rupture. We previously reported that size ratio (SR), IA size divided by parent vessel diameter, correlated strongly with IA rupture status (ruptured versus unruptured). These data were all collected retrospectively off 3-dimensional angiographic images. Therefore, we performed a blinded prospective collection and evaluation of SR data from 2-dimensional angiographic images for a consecutive series of patients with ruptured and unruptured IAs. We prospectively enrolled 40 consecutive patients presenting to a single institution with either ruptured IA or for first-time evaluation of an incidental IA. Blinded technologists acquired all measurements from 2-dimensional angiographic images. Aneurysm rupture status, location, IA maximum size, and parent vessel diameter were documented. The SR was calculated by dividing the aneurysm size (mm) by the average parent vessel size (mm). A 2-tailed Mann-Whitney test was performed to assess statistical significance between ruptured and unruptured groups. Fisher exact test was used to compare medical comorbidities between the ruptured and unruptured groups. Significant differences between the 2 groups were subsequently tested with logistic regression. SE and probability values are reported. Forty consecutive patients with 24 unruptured and 16 ruptured aneurysms met the inclusion criteria. No significant differences were found in age, gender, smoking status, or medical comorbidities between ruptured and unruptured groups. The average maximum size of the unruptured IAs (6.18 + or - 0.60 mm) was significantly smaller compared with the ruptured IAs (7.91 + or - 0.47 mm; P=0.03), and the unruptured group had significantly smaller SRs (2.57 + or - 0.24 mm) compared with the ruptured group (4.08 + or - 0.54 mm; P<0.01). Logistic regression was used to evaluate the independent predictive value of those variables that achieved significance in univariate analysis (IA maximum size and SR). Using stepwise selection, only SR remained in the final predictive model (OR, 2.12; 95% CI, 1.09 to 4.13). SR, the ratio between aneurysm size and parent artery diameter, can be easily calculated from 2-dimensional angiograms and correlates with IA rupture status on presentation in a blinded analysis. SR should be further studied in a large prospective observational cohort to predict true IA risk of rupture.

Preterm premature rupture of membranes at 22-25 weeks' gestation: perinatal and 2-year outcomes within a national population-based study (EPIPAGE-2).

PubMed

Lorthe, Elsa; Torchin, Héloïse; Delorme, Pierre; Ancel, Pierre-Yves; Marchand-Martin, Laetitia; Foix-L'helias, Laurence; Benhammou, Valérie; Gire, Catherine; D'Ercole, Claude; Winer, Norbert; Sentilhes, Loïc; Subtil, Damien; Goffinet, François; Kayem, Gilles

2018-05-28

Most clinical guidelines state that with early preterm premature rupture of membranes, obstetric and pediatric teams must share a realistic and individualized appraisal of neonatal outcomes with parents and consider their wishes for all decisions. However, we currently lack reliable and relevant data, according to gestational age at rupture of membranes, to adequately counsel parents during pregnancy and to reflect on our policies of care at these extreme gestational ages. To describe both perinatal and 2-year outcomes of preterm infants born after preterm premature rupture of membranes at 22-25 weeks' gestation. EPIPAGE-2 is a French national prospective population-based cohort of preterm infants born in 546 maternity units in 2011. Inclusion criteria in this analysis were women diagnosed with preterm premature rupture of membranes at 22-25 weeks' gestation and singleton or twin gestations with fetus(es) alive at rupture of membranes. Latency duration, antenatal management, and outcomes (survival at discharge, survival at discharge without severe morbidity, and survival at 2 years' corrected age without cerebral palsy) were described and compared by gestational age at preterm premature rupture of membranes. Among the 1435 women with a diagnosis of preterm premature rupture of membranes, 379 were at 22-25 weeks' gestation, with 427 fetuses (331 singletons and 96 twins). Median GA at preterm premature rupture of membranes and at birth were 24 (interquartile range 23-25) and 25 (24-27) weeks, respectively. For each gestational age at preterm premature rupture of membranes, nearly half of the fetuses were born within the week after the rupture of membranes. Among the 427 fetuses, 51.7% were survivors at discharge (14.1%, 39.5%, 66.8% and 75.8% with preterm premature rupture of membranes at 22, 23, 24 and 25 weeks, respectively), 38.8% were survivors at discharge without severe morbidity and 46.4% were survivors at 2 years without cerebral palsy, with wide variations by gestational age at preterm premature rupture of membranes. Survival at 2 years without cerebral palsy was low with preterm premature rupture of membranes at 22 and 23 weeks but reached approximately 60% and 70% with preterm premature rupture of membranes at 24 and 25 weeks. Preterm premature rupture of membranes at 22-25 weeks is associated with high incidence of mortality and morbidity, with wide variations by gestational age at preterm premature rupture of membranes. However, a non-negligible proportion of children survive without severe morbidity both at discharge and at 2-years' corrected age. Copyright © 2018 Elsevier Inc. All rights reserved.

Induced seismicity provides insight into why earthquake ruptures stop

PubMed Central

Galis, Martin; Ampuero, Jean Paul; Mai, P. Martin; Cappa, Frédéric

2017-01-01

Injection-induced earthquakes pose a serious seismic hazard but also offer an opportunity to gain insight into earthquake physics. Currently used models relating the maximum magnitude of injection-induced earthquakes to injection parameters do not incorporate rupture physics. We develop theoretical estimates, validated by simulations, of the size of ruptures induced by localized pore-pressure perturbations and propagating on prestressed faults. Our model accounts for ruptures growing beyond the perturbed area and distinguishes self-arrested from runaway ruptures. We develop a theoretical scaling relation between the largest magnitude of self-arrested earthquakes and the injected volume and find it consistent with observed maximum magnitudes of injection-induced earthquakes over a broad range of injected volumes, suggesting that, although runaway ruptures are possible, most injection-induced events so far have been self-arrested ruptures. PMID:29291250

Systematic Underestimation of Earthquake Magnitudes from Large Intracontinental Reverse Faults: Historical Ruptures Break Across Segment Boundaries

NASA Technical Reports Server (NTRS)

Rubin, C. M.

1996-01-01

Because most large-magnitude earthquakes along reverse faults have such irregular and complicated rupture patterns, reverse-fault segments defined on the basis of geometry alone may not be very useful for estimating sizes of future seismic sources. Most modern large ruptures of historical earthquakes generated by intracontinental reverse faults have involved geometrically complex rupture patterns. Ruptures across surficial discontinuities and complexities such as stepovers and cross-faults are common. Specifically, segment boundaries defined on the basis of discontinuities in surficial fault traces, pronounced changes in the geomorphology along strike, or the intersection of active faults commonly have not proven to be major impediments to rupture. Assuming that the seismic rupture will initiate and terminate at adjacent major geometric irregularities will commonly lead to underestimation of magnitudes of future large earthquakes.

The persistence of directivity in small earthquakes

USGS Publications Warehouse

Boatwright, J.

2007-01-01

We derive a simple inversion of peak ground acceleration (PGA) or peak ground velocity (PGV) for rupture direction and rupture velocity and then test this inversion on the peak motions obtained from seven 3.5 ??? M ??? 4.1 earthquakes that occurred in two clusters in November 2002 and February 2003 near San Ramon, California. These clusters were located on two orthogonal strike-slip faults so that the events share the same approximate focal mechanism but not the same fault plane. Three earthquakes exhibit strong directivity, but the other four earthquakes exhibit relatively weak directivity. We use the residual PGAs and PGVs from the other six events to determine station corrections for each earthquake. The inferred rupture directions unambiguously identify the fault plane for the three earthquakes with strong directivity and for three of the four earthquakes with weak directivity. The events with strong directivity have fast rupture velocities (0.63????? v ??? 0.87??); the events with weak directivity either rupture more slowly (0.17????? v ???0.35??) or bilaterally. The simple unilateral inversion cannot distinguish between slow and bilateral ruptures: adding a bilateral rupture component degrades the fit of the rupture directions to the fault planes. By comparing PGAs from the events with strong and weak directivity, we show how an up-dip rupture in small events can distort the attenuation of peak ground motion with distance. When we compare the rupture directions of the earthquakes to the location of aftershocks in the two clusters, we find than almost all the aftershocks of the three earthquakes with strong directivity occur within 70?? of the direction of rupture.

Role of intramural platelet thrombus in the pathogenesis of wall rupture and intra-ventricular thrombosis following acute myocardial infarction.

PubMed

Du, Xiao-Jun; Shan, Leonard; Gao, Xiao-Ming; Kiriazis, Helen; Liu, Yang; Lobo, Abhirup; Head, Geoffrey A; Dart, Anthony M

2011-02-01

Left ventricular thrombus (LVT) and rupture are important mechanical complications following myocardial infarction (MI) and are believed to be due to unrelated mechanisms. We studied whether, in fact, wall rupture and LVT are closely related in their pathogenesis with intramural platelet thrombus (IMT) playing a pivotal role. Male 129sv and C57Bl/6 mice underwent operation to induce MI, and autopsy was performed to confirm rupture deaths. Haemodynamic features of rupture events were monitored by telemetry in conscious mice. Detailed histological examination was conducted with special attention to the presence of IMT in relation to rupture location and LVT formation. IMT was detected in infarcted hearts of 129sv (82%) and C57Bl/6 (39%) mice with rupture in the form of a narrow streak spanning the wall or an occupying mass dissecting the infarcted myofibers apart. IMT often contained dense inflammatory cells and blood clot, indicating a dynamic process of thrombus formation and destruction. Notably, IMT was found extending into the cavity to form LVT. Haemodynamic monitoring by telemetry revealed that rupture occurred either as a single event or recurrent episodes. Importantly, the anti-platelet drug clopidogrel, but not aspirin, reduced the prevalence of rupture (10% vs. 45%) and IMT, and suppressed the degree of inflammation. Thus, IMT is a key pathological element in the infarcted heart closely associated with the complications of rupture and LVT. IMT could be either triggered by a wall tear or act as initiator of rupture. IMT may propagate towards the ventricular chamber to trigger LVT.

Infectious mononucleosis presenting as spontaneous splenic rupture without other symptoms.

PubMed

Stockinger, Zsolt T

2003-09-01

Splenic rupture is an uncommon complication of infectious mononucleosis (IM), occurring in 0.1% to 0.5% of all patients. It remains the most common lethal complication of IM. Rupture of the spleen with no other symptoms of IM is almost unheard of. This is the report of a case of spontaneous splenic rupture requiring splenectomy in a patient with a positive heterophil antibody test and no other signs or symptoms of IM. The diagnosis and management of splenic rupture in IM are discussed.

Time-resolved observation of thermally activated rupture of a capillary-condensed water nanobridge

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bak, Wan; Sung, Baekman; Kim, Jongwoo

2015-01-05

The capillary-condensed liquid bridge is one of the most ubiquitous forms of liquid in nature and contributes significantly to adhesion and friction of biological molecules as well as microscopic objects. Despite its important role in nanoscience and technology, the rupture process of the bridge is not well understood and needs more experimental works. Here, we report real-time observation of rupture of a capillary-condensed water nanobridge in ambient condition. During slow and stepwise stretch of the nanobridge, we measured the activation time for rupture, or the latency time required for the bridge breakup. By statistical analysis of the time-resolved distribution ofmore » activation time, we show that rupture is a thermally activated stochastic process and follows the Poisson statistics. In particular, from the Arrhenius law that the rupture rate satisfies, we estimate the position-dependent activation energies for the capillary-bridge rupture.« less

Systematic observations of the slip pulse properties of large earthquake ruptures

USGS Publications Warehouse

Melgar, Diego; Hayes, Gavin

2017-01-01

In earthquake dynamics there are two end member models of rupture: propagating cracks and self-healing pulses. These arise due to different properties of faults and have implications for seismic hazard; rupture mode controls near-field strong ground motions. Past studies favor the pulse-like mode of rupture; however, due to a variety of limitations, it has proven difficult to systematically establish their kinematic properties. Here we synthesize observations from a database of >150 rupture models of earthquakes spanning M7–M9 processed in a uniform manner and show the magnitude scaling properties of these slip pulses indicates self-similarity. Further, we find that large and very large events are statistically distinguishable relatively early (at ~15 s) in the rupture process. This suggests that with dense regional geophysical networks strong ground motions from a large rupture can be identified before their onset across the source region.

Seismogenic width controls aspect ratios of earthquake ruptures

NASA Astrophysics Data System (ADS)

Weng, Huihui; Yang, Hongfeng

2017-03-01

We investigate the effect of seismogenic width on aspect ratios of earthquake ruptures by using numerical simulations of strike-slip faulting and an energy balance criterion near rupture tips. If the seismogenic width is smaller than a critical value, then ruptures cannot break the entire fault, regardless of the size of the nucleation zone. The seismic moments of these self-arresting ruptures increase with the nucleation size, forming nucleation-related events. The aspect ratios increase with the seismogenic width but are smaller than 8. In contrast, ruptures become breakaway and tend to have high aspect ratios (>8) if the seismogenic width is sufficiently large. But the critical nucleation size is larger than the theoretical estimate for an unbounded fault. The eventual seismic moments of breakaway ruptures do not depend on the nucleation size. Our results suggest that estimating final earthquake magnitude from the nucleation phase may only be plausible on faults with small seismogenic width.

A retrospective study of eyeball rupture in patients with or without orbital fracture

PubMed Central

Chen, Xiang; Yao, Yi; Wang, Fengxiang; Liu, Tiecheng; Zhao, Xiao

2017-01-01

Abstract To summarize the clinical features of eyeball rupture with or without orbital fracture and explore the differences between them. In all, 197 patients were observed, and the following data were recorded: sex, age, time of injury, place of injury, cause of trauma, zone of eye injury, intraocular content prolapse, surgical methods and the therapeutic process, visual acuity after injury, and the final best corrected visual acuity. The results were analyzed for statistically significant differences. There was no significant difference (P > .05) in the age, sex, or cause of injury. Patients with eyeball rupture with fracture had poorer vision than did those in the simple eyeball rupture group; eyeball rupture with fracture also had a higher probability of enucleation. In this study, the clinical results show that prognosis of eyeball rupture with orbital fracture is worse than that of eyeball rupture without orbital fracture. PMID:28614230

A retrospective study of eyeball rupture in patients with or without orbital fracture.

PubMed

Chen, Xiang; Yao, Yi; Wang, Fengxiang; Liu, Tiecheng; Zhao, Xiao

2017-06-01

To summarize the clinical features of eyeball rupture with or without orbital fracture and explore the differences between them.In all, 197 patients were observed, and the following data were recorded: sex, age, time of injury, place of injury, cause of trauma, zone of eye injury, intraocular content prolapse, surgical methods and the therapeutic process, visual acuity after injury, and the final best corrected visual acuity. The results were analyzed for statistically significant differences.There was no significant difference (P > .05) in the age, sex, or cause of injury. Patients with eyeball rupture with fracture had poorer vision than did those in the simple eyeball rupture group; eyeball rupture with fracture also had a higher probability of enucleation.In this study, the clinical results show that prognosis of eyeball rupture with orbital fracture is worse than that of eyeball rupture without orbital fracture.

Heterogeneous rupture on homogenous faults: Three-dimensional spontaneous rupture simulations with thermal pressurization

NASA Astrophysics Data System (ADS)

Urata, Yumi; Kuge, Keiko; Kase, Yuko

2008-11-01

To understand role of fluid on earthquake rupture processes, we investigated effects of thermal pressurization on spatial variation of dynamic rupture by computing spontaneous rupture propagation on a rectangular fault. We found thermal pressurization can cause heterogeneity of rupture even on a fault of uniform properties. On drained faults, tractions drop linearly with increasing slip in the same way everywhere. However, by changing the drained condition to an undrained one, the slip-weakening curves become non-linear and depend on locations on faults with small shear zone thickness w, and the dynamic frictional stresses vary spatially and temporally. Consequently, the super-shear transition fault length decreases for small w, and the final slip distribution can have some peaks regardless of w, especially on undrained faults. These effects should be taken into account of determining dynamic rupture parameters and modeling earthquake cycles when the presence of fluid is suggested in the source regions.

[Traumatic rupture of hepatic hydatid cyst].

PubMed

Martino, A; Rampone, B; Schiavone, B; Viviano, C; Cuomo, O; Iovine, L; Sacco, M; Maharajan, G; Confuorto, G

2010-01-01

Hydatid disease is endemic in some areas of the world. It is located mostly in the liver. The cysts rupture is possible after a trauma, or spontaneously by the increase of intracystic pressure. Rupture of the hydatid cyst requires urgent surgical intervention. We report our experience in treatment of traumatic rupture of hepatic hydatid cyst.

Risk factors for achilles tendon rupture: A matched case control study.

PubMed

Noback, Peter C; Jang, Eugene S; Cuellar, Derly O; Seetharaman, Mani; Malagoli, Emiliano; Greisberg, Justin K; Vosseller, J Turner

2017-10-01

The purpose of this study was to elucidate whether body mass index (BMI), activity level, and other risk factors predispose patients to Achilles tendon ruptures. A retrospective review of 279 subjects was performed (93 with Achilles tendon rupture, matched 1:2 with 186 age/sex matched controls with ankle sprains). Demographic variables and risk factors for rupture were tabulated and compared. The rupture group mean BMI was 27.77 (95% CI, 26.94-28.49), and the control group mean BMI was 26.66 (95% CI, 26.06-27.27). These populations were found to be statistically equivalent (p=0.047 and p<0.001 by two one-sided t-test). A significantly higher proportion of those suffering ruptures reported regular athletic activity at baseline (74%) versus controls (59%, p=0.013). There was no clinically significant difference found in BMI between patients with ruptures and controls. Furthermore, it was found that patients who sustained ruptures were also more likely to be active at baseline than their ankle sprain counterparts. Copyright © 2017 Elsevier Ltd. All rights reserved.

High-speed rupture during the initiation of the 2015 Bonin Islands deep earthquake

NASA Astrophysics Data System (ADS)

Zhan, Z.; Ye, L.; Shearer, P. M.; Lay, T.; Kanamori, H.

2015-12-01

Among the long-standing questions on how deep earthquakes rupture, the nucleation phase of large deep events is one of the most puzzling parts. Resolving the rupture properties of the initiation phase is difficult to achieve with far-field data because of the need for accurate corrections for structural effects on the waveforms (e.g., attenuation, scattering, and site effects) and alignment errors. Here, taking the 2015 Mw 7.9 Bonin Islands earthquake (depth = 678 km) as an example, we jointly invert its far-field P waves at multiple stations for the average rupture speed during the first second of the event. We use waveforms from a closely located aftershock as empirical Green's functions, and correct for possible differences in focal mechanisms and waveform misalignments with an iterative approach. We find that the average initial rupture speed is over 5 km/s, significantly higher than the average rupture speed of 3 km/s later in the event. This contrast suggests that rupture speeds of deep earthquakes can be highly variable during individual events and may define different stages of rupture, potentially with different mechanisms.

Partial achilles tendon rupture presenting with giant hematoma; MRI findings of 4 year follow up.

PubMed

Sarsilmaz, Aysegul; Varer, Makbule; Coskun, Gulten; Apaydın, Melda; Oyar, Orhan

2011-12-01

In the young population, spontaneous rupture of Achilles tendon is very rare. The big hematoma is also rare finding of the Achilles tendon partial rupture. It is usually seen with complete rupture. We presented imaging findings of 4 years follow up of the spontaneous partial rupture of Achilles tendon presenting with giant expanding hematoma and mimicking complete rupture radiologically. We discussed the alterations of tendon signal intensity and result of conservative therapy after partial rupture with big hematoma in the long term. A 29 year-old man, applied with pain and swelling in the retrocalcaneal region of left ankle. He did not have chronic metabolic disease. He was not active in physical activities. X-ray radiograms were normal. At magnetic resonance images (MRI), there was an intratendinous big hematoma, subcutanous fat planes were edematous around tendon. The diagnosis was partial rupture and giant hematoma. Hematoma was drained. The conservative treatment was applied and his complaints disappeared. After treatment, approximately 4 years later, control MRI showed thickened and hypointense tendon in all images. Crown Copyright © 2011. Published by Elsevier Ltd. All rights reserved.

Shigella subverts the host recycling compartment to rupture its vacuole.

PubMed

Mellouk, Nora; Weiner, Allon; Aulner, Nathalie; Schmitt, Christine; Elbaum, Michael; Shorte, Spencer L; Danckaert, Anne; Enninga, Jost

2014-10-08

Shigella enters epithlial cells via internalization into a vacuole. Subsequent vacuolar membrane rupture allows bacterial escape into the cytosol for replication and cell-to-cell spread. Bacterial effectors such as IpgD, a PI(4,5)P2 phosphatase that generates PI(5)P and alters host actin, facilitate this internalization. Here, we identify host proteins involved in Shigella uptake and vacuolar membrane rupture by high-content siRNA screening and subsequently focus on Rab11, a constituent of the recycling compartment. Rab11-positive vesicles are recruited to the invasion site before vacuolar rupture, and Rab11 knockdown dramatically decreases vacuolar membrane rupture. Additionally, Rab11 recruitment is absent and vacuolar rupture is delayed in the ipgD mutant that does not dephosphorylate PI(4,5)P₂ into PI(5)P. Ultrastructural analyses of Rab11-positive vesicles further reveal that ipgD mutant-containing vacuoles become confined in actin structures that likely contribute to delayed vacular rupture. These findings provide insight into the underlying molecular mechanism of vacuole progression and rupture during Shigella invasion. Copyright © 2014 Elsevier Inc. All rights reserved.

Rupture history of 2008 May 12 Mw 8.0 Wen-Chuan earthquake: Evidence of slip interaction

NASA Astrophysics Data System (ADS)

Ji, C.; Shao, G.; Lu, Z.; Hudnut, K.; Jiu, J.; Hayes, G.; Zeng, Y.

2008-12-01

We will present the rupture process of the May 12, 2008 Mw 8.0 Wenchuan earthquake using all available data. The current model, using both teleseismic body and surface waves and interferometric LOS displacements, reveals an unprecedented complex rupture process which can not be resolved using either of the datasets individually. Rupture of this earthquake involved both the low angle Pengguan fault and the high angle Beichuan fault, which intersect each other at depth and are separated approximately 5-15 km at the surface. Rupture initiated on the Pengguan fault and triggered rupture on the Beichuan fault 10 sec later. The two faults dynamically interacted and unilaterally ruptured over 270 km with an average rupture velocity of 3.0 km/sec. The total seismic moment is 1.1x1021 Nm (Mw 8.0), roughly equally partitioned between the two faults. However, the spatiotemporal evaluations of the two faults are very different. This study will focus on the evidence for fault interactions and will analyze the corresponding uncertainties, in preparation for future dynamic studies of the same detailed nature.

Pulsed strain release on the Altyn Tagh fault, northwest China

USGS Publications Warehouse

Gold, Ryan D.; Cowgill, Eric; Arrowsmith, J. Ramón; Friedrich, Anke M.

2017-01-01

Earthquake recurrence models assume that major surface-rupturing earthquakes are followed by periods of reduced rupture probability as stress rebuilds. Although purely periodic, time- or slip-predictable rupture models are known to be oversimplifications, a paucity of long records of fault slip clouds understanding of fault behavior and earthquake recurrence over multiple ruptures. Here, we report a 16 kyr history of fault slip—including a pulse of accelerated slip from 6.4 to 6.0 ka—determined using a Monte Carlo analysis of well-dated offset landforms along the central Altyn Tagh strike-slip fault (ATF) in northwest China. This pulse punctuates a median rate of 8.1+1.2/−0.9 mm/a and likely resulted from either a flurry of temporally clustered ∼Mw 7.5 ground-rupturing earthquakes or a single large >Mw 8.2 earthquake. The clustered earthquake scenario implies rapid re-rupture of a fault reach >195 km long and indicates decoupled rates of elastic strain energy accumulation versus dissipation, conceptualized as a crustal stress battery. If the pulse reflects a single event, slip-magnitude scaling implies that it ruptured much of the ATF with slip similar to, or exceeding, the largest documented historical ruptures. Both scenarios indicate fault rupture behavior that deviates from classic time- or slip-predictable models.

Identification of vortex structures in a cohort of 204 intracranial aneurysms

PubMed Central

Trylesinski, Gabriel; Xiang, Jianping; Snyder, Kenneth; Meng, Hui

2017-01-01

An intracranial aneurysm (IA) is a cerebrovascular pathology that can lead to death or disability if ruptured. Abnormal wall shear stress (WSS) has been associated with IA growth and rupture, but little is known about the underlying flow physics related to rupture-prone IAs. Previous studies, based on analysis of a few aneurysms or partial views of three-dimensional vortex structures, suggest that rupture is associated with complex vortical flow inside IAs. To further elucidate the relevance of vortical flow in aneurysm pathophysiology, we studied 204 patient IAs (56 ruptured and 148 unruptured). Using objective quantities to identify three-dimensional vortex structures, we investigated the characteristics associated with aneurysm rupture and if these features correlate with previously proposed WSS and morphological characteristics indicative of IA rupture. Based on the Q-criterion definition of a vortex, we quantified the degree of the aneurysmal region occupied by vortex structures using the volume vortex fraction (vVF) and the surface vortex fraction (sVF). Computational fluid dynamics simulations showed that the sVF, but not the vVF, discriminated ruptured from unruptured aneurysms. Furthermore, we found that the near-wall vortex structures co-localized with regions of inflow jet breakdown, and significantly correlated to previously proposed haemodynamic and morphologic characteristics of ruptured IAs. PMID:28539480

Identification of vortex structures in a cohort of 204 intracranial aneurysms.

PubMed

Varble, Nicole; Trylesinski, Gabriel; Xiang, Jianping; Snyder, Kenneth; Meng, Hui

2017-05-01

An intracranial aneurysm (IA) is a cerebrovascular pathology that can lead to death or disability if ruptured. Abnormal wall shear stress (WSS) has been associated with IA growth and rupture, but little is known about the underlying flow physics related to rupture-prone IAs. Previous studies, based on analysis of a few aneurysms or partial views of three-dimensional vortex structures, suggest that rupture is associated with complex vortical flow inside IAs. To further elucidate the relevance of vortical flow in aneurysm pathophysiology, we studied 204 patient IAs (56 ruptured and 148 unruptured). Using objective quantities to identify three-dimensional vortex structures, we investigated the characteristics associated with aneurysm rupture and if these features correlate with previously proposed WSS and morphological characteristics indicative of IA rupture. Based on the Q -criterion definition of a vortex, we quantified the degree of the aneurysmal region occupied by vortex structures using the volume vortex fraction ( vVF ) and the surface vortex fraction ( sVF ). Computational fluid dynamics simulations showed that the sVF , but not the vVF , discriminated ruptured from unruptured aneurysms. Furthermore, we found that the near-wall vortex structures co-localized with regions of inflow jet breakdown, and significantly correlated to previously proposed haemodynamic and morphologic characteristics of ruptured IAs. © 2017 The Author(s).

Spontaneous splenic rupture in an active duty Marine upon return from Iraq: a case report

PubMed Central

2010-01-01

Introduction Atraumatic splenic rupture is a rare event that has been associated with several infectious disease processes. In the active duty military population, potential exposure to these pathogens is significant. Here we discuss the case of an active duty Marine with spontaneous splenic rupture upon return from a six-month deployment in Iraq. Case presentation A previously healthy 30-year-old Caucasian male active duty Marine presented with abdominal pain, fever and diarrhea after deployment to Iraq in support of Operation Iraqi Freedom. Based on clinical and radiographic evidence, a diagnosis of spontaneous splenic rupture was ultimately suspected. After exploratory laparotomy with confirmation of rupture, splenectomy was performed, and the patient made a full, uneventful recovery. Histopathologic examination revealed mild splenomegaly with a ruptured capsule of undetermined cause. Conclusion Spontaneous splenic rupture is a rare event that may lead to life-threatening hemorrhage if not diagnosed and treated quickly. Although the cause of this patient's case was unknown, atraumatic splenic rupture has been associated with a variety of infectious diseases and demonstrates some risks the active duty military population may face while on deployment. Having an awareness of these pathogens and their role in splenic rupture, clinicians caring for military personnel must be prepared to recognize and treat this potentially fatal complication. PMID:21054871

Diverse rupture processes in the 2015 Peru deep earthquake doublet.

PubMed

Ye, Lingling; Lay, Thorne; Kanamori, Hiroo; Zhan, Zhongwen; Duputel, Zacharie

2016-06-01

Earthquakes in deeply subducted oceanic lithosphere can involve either brittle or dissipative ruptures. On 24 November 2015, two deep (606 and 622 km) magnitude 7.5 and 7.6 earthquakes occurred 316 s and 55 km apart. The first event (E1) was a brittle rupture with a sequence of comparable-size subevents extending unilaterally ~50 km southward with a rupture speed of ~4.5 km/s. This earthquake triggered several aftershocks to the north along with the other major event (E2), which had 40% larger seismic moment and the same duration (~20 s), but much smaller rupture area and lower rupture speed than E1, indicating a more dissipative rupture. A minor energy release ~12 s after E1 near the E2 hypocenter, possibly initiated by the S wave from E1, and a clear aftershock ~165 s after E1 also near the E2 hypocenter, suggest that E2 was likely dynamically triggered. Differences in deep earthquake rupture behavior are commonly attributed to variations in thermal state between subduction zones. However, the marked difference in rupture behavior of the nearby Peru doublet events suggests that local variations of stress state and material properties significantly contribute to diverse behavior of deep earthquakes.

Risk Factors for the Rupture of Intracranial Aneurysms Using Computed Tomography Angiography.

PubMed

Wang, Guang-Xian; Wen, Li; Yang, Liu; Zhang, Qi-Chuang; Yin, Jin-Bo; Duan, Chun-Mei; Zhang, Dong

2018-02-01

To study the clinical and morphologic characteristics associated with risk factors for the rupture of intracranial aneurysms (IAs). A total of 1115 consecutive patients with 1282 IAs were reviewed from August 2011 to February 2016. The patients and IAs were divided into ruptured and unruptured groups. Based on the clinical and morphologic findings, the risk factors for IA rupture were assessed using statistical methods. Age, hypertension, diabetes mellitus, and cerebral atherosclerosis were associated with ruptured IAs. IAs located in the anterior cerebral artery, the anterior communicating artery, the posterior communicating artery, and the internal carotid artery were associated with ruptured IAs. Ruptures were also associated with arterial bifurcations, irregular aneurysm shapes, and all continuous data, except neck width. Binary logistic regression showed that IAs located at bifurcations (odds ratio [OR], 1.804), with irregular shapes (OR, 4.677), with high aspect ratios (ARs) (OR, 5.037) or with small mean diameters (MDs) (OR, 0.495) are more prone to rupture. Receiver operating characteristic analysis showed that the threshold values of the AR and MD were 1 and 3.70 mm, respectively. Morphologic characteristics, such as being located at bifurcations, being irregularly shaped, having a high AR (>1), and having a small MD (<3.70 mm), were better predictors of rupture. Copyright © 2017 Elsevier Inc. All rights reserved.

Correlation between atmospheric pressure changes and abdominal aortic aneurysm rupture: results of a single-center study.

PubMed

Molacek, Jiri; Treska, Vladislav; Kasik, Miroslav; Houdek, Karel; Baxa, Jan

2013-09-01

There is much interest in all factors that influence the etiopathogenesis of abdominal aortic aneurysm (AAA) rupture. Apart from the well-established factors such as arterial hypertension, smoking, age, and genetic predisposition, less common factors that may play a role in the mechanism of the rupture are the subject of much discussion. These include atmospheric conditions, temperature, and atmospheric pressure. We conducted this study to investigate the effects of the absolute value of atmospheric pressure and its changes on the frequency of AAA rupture. We retrospectively examined 54 patients who underwent treatment for a ruptured AAA at the Clinic of Surgery in the University Hospital in Pilsen between 1 January 2005 and 31 December 2009. We collected data on the atmospheric pressure in this period from the Czech Hydrometeorological Institute in Pilsen. We did not find a significant difference in atmospheric pressure values between the days when the rupture occurred versus the other days (p < 0.5888). Moreover, we did not find significant changes in the atmospheric pressure during the 48 h preceding the rupture (Student's test p < 0.4434) versus the day of rupture or in the mean atmospheric pressure in that month. These findings suggest that atmospheric pressure and its changes do not affect the pathogenesis of AAA rupture.

Dynamic rupture modeling of thrust faults with parallel surface traces.

NASA Astrophysics Data System (ADS)

Peshette, P.; Lozos, J.; Yule, D.

2017-12-01

Fold and thrust belts (such as those found in the Himalaya or California Transverse Ranges) consist of many neighboring thrust faults in a variety of geometries. Active thrusts within these belts individually contribute to regional seismic hazard, but further investigation is needed regarding the possibility of multi-fault rupture in a single event. Past analyses of historic thrust surface traces suggest that rupture within a single event can jump up to 12 km. There is also observational precedent for long distance triggering between subparallel thrusts (e.g. the 1997 Harnai, Pakistan events, separated by 50 km). However, previous modeling studies find a maximum jumping rupture distance between thrust faults of merely 200 m. Here, we present a new dynamic rupture modeling parameter study that attempts to reconcile these differences and determine which geometrical and stress conditions promote jumping rupture. We use a community verified 3D finite element method to model rupture on pairs of thrust faults with parallel surface traces. We vary stress drop and fault strength to determine which conditions produce jumping rupture at different dip angles and different separations between surface traces. This parameter study may help to understand the likelihood of jumping rupture in real-world thrust systems, and may thereby improve earthquake hazard assessment.

A multiple fault rupture model of the November 13 2016, M 7.8 Kaikoura earthquake, New Zealand

NASA Astrophysics Data System (ADS)

Benites, R. A.; Francois-Holden, C.; Langridge, R. M.; Kaneko, Y.; Fry, B.; Kaiser, A. E.; Caldwell, T. G.

2017-12-01

The rupture-history of the November 13 2016 MW7.8 Kaikoura earthquake recorded by near- and intermediate-field strong-motion seismometers and 2 high-rate GPS stations reveals a complex cascade of multiple crustal fault rupture. In spite of such complexity, we show that the rupture history of each fault is well approximated by simple kinematic model with uniform slip and rupture velocity. Using 9 faults embedded in a crustal layer 19 km thick, each with a prescribed slip vector and rupture velocity, this model accurately reproduces the displacement waveforms recorded at the near-field strong-motion and GPS stations. This model includes the `Papatea Fault' with a mixed thrust and strike-slip mechanism based on in-situ geological observations with up to 8 m of uplift observed. Although the kinematic model fits the ground-motion at the nearest strong station, it doesn not reproduce the one sided nature of the static deformation field observed geodetically. This suggests a dislocation based approach does not completely capture the mechanical response of the Papatea Fault. The fault system as a whole extends for approximately 150 km along the eastern side of the Marlborough fault system in the South Island of New Zealand. The total duration of the rupture was 74 seconds. The timing and location of each fault's rupture suggests fault interaction and triggering resulting in a northward cascade crustal ruptures. Our model does not require rupture of the underlying subduction interface to explain the data.

Pseudo-dynamic source characterization accounting for rough-fault effects

NASA Astrophysics Data System (ADS)

Galis, Martin; Thingbaijam, Kiran K. S.; Mai, P. Martin

2016-04-01

Broadband ground-motion simulations, ideally for frequencies up to ~10Hz or higher, are important for earthquake engineering; for example, seismic hazard analysis for critical facilities. An issue with such simulations is realistic generation of radiated wave-field in the desired frequency range. Numerical simulations of dynamic ruptures propagating on rough faults suggest that fault roughness is necessary for realistic high-frequency radiation. However, simulations of dynamic ruptures are too expensive for routine applications. Therefore, simplified synthetic kinematic models are often used. They are usually based on rigorous statistical analysis of rupture models inferred by inversions of seismic and/or geodetic data. However, due to limited resolution of the inversions, these models are valid only for low-frequency range. In addition to the slip, parameters such as rupture-onset time, rise time and source time functions are needed for complete spatiotemporal characterization of the earthquake rupture. But these parameters are poorly resolved in the source inversions. To obtain a physically consistent quantification of these parameters, we simulate and analyze spontaneous dynamic ruptures on rough faults. First, by analyzing the impact of fault roughness on the rupture and seismic radiation, we develop equivalent planar-fault kinematic analogues of the dynamic ruptures. Next, we investigate the spatial interdependencies between the source parameters to allow consistent modeling that emulates the observed behavior of dynamic ruptures capturing the rough-fault effects. Based on these analyses, we formulate a framework for pseudo-dynamic source model, physically consistent with the dynamic ruptures on rough faults.

Intrinsic, Transitional, and Extrinsic Morphological Factors Associated With Rupture of Intracranial Aneurysms.

PubMed

Ho, Allen L; Lin, Ning; Frerichs, Kai U; Du, Rose

2015-09-01

As diagnosis and treatment of unruptured intracranial aneurysms continues to increase, management principles remain largely based on size. This is despite mounting evidence that aneurysm location and other morphologic variables could play a role in predicting overall risk of rupture. Morphological parameters can be divided into 3 main groups, those that are intrinsic to the aneurysm, those that are extrinsic to the aneurysm, and those that involve both the aneurysm and surrounding vasculature (transitional). We present an evaluation of intrinsic, transitional, and extrinsic factors and their association with ruptured aneurysms. Using preoperative computed tomographic angiography, we generated 3-dimensional models of aneurysms and their surrounding vasculature with Slicer software. Using univariate and multivariate analyses, we examined the association of intrinsic, transitional, and extrinsic aspects of aneurysm morphology with rupture. Between 2005 and 2013, 227 cerebral aneurysms in 4 locations were evaluated/treated at a single institution, and computed tomographic angiographies of 218 patients (97 unruptured and 130 ruptured) were analyzed. Ruptured aneurysms analyzed were associated with clinical factors of absence of multiple aneurysms and history of no prior rupture, and morphologic factors of greater aspect ratio. On multivariate analysis, aneurysm rupture remained associated with history of no prior rupture, greater flow angle, greater daughter-daughter vessel angle, and smaller parent-daughter vessel angle. By studying the morphology of aneurysms and their surrounding vasculature, we identified several parameters associated with ruptured aneurysms that include intrinsic, transitional, and extrinsic factors of cerebral aneurysms and their surrounding vasculature.

Modeling 3D Dynamic Rupture on Arbitrarily-Shaped faults by Boundary-Conforming Finite Difference Method

NASA Astrophysics Data System (ADS)

Zhu, D.; Zhu, H.; Luo, Y.; Chen, X.

2008-12-01

We use a new finite difference method (FDM) and the slip-weakening law to model the rupture dynamics of a non-planar fault embedded in a 3-D elastic media with free surface. The new FDM, based on boundary- conforming grid, sets up the mapping equations between the curvilinear coordinate and the Cartesian coordinate and transforms irregular physical space to regular computational space; it also employs a higher- order non-staggered DRP/opt MacCormack scheme which is of low dispersion and low dissipation so that the high accuracy and stability of our rupture modeling are guaranteed. Compared with the previous methods, not only we can compute the spontaneous rupture of an arbitrarily shaped fault, but also can model the influence of the surface topography on the rupture process of earthquake. In order to verify the feasibility of this method, we compared our results and other previous results, and found out they matched perfectly. Thanks to the boundary-conforming FDM, problems such as dynamic rupture with arbitrary dip, strike and rake over an arbitrary curved plane can be handled; and supershear or subshear rupture can be simulated with different parameters such as the initial stresses and the critical slip displacement Dc. Besides, our rupture modeling is economical to be implemented owing to its high efficiency and does not suffer from displacement leakage. With the help of inversion data of rupture by field observations, this method is convenient to model rupture processes and seismograms of natural earthquakes.

The evolution of slip pulses within bimaterial interfaces with rupture velocity

NASA Astrophysics Data System (ADS)

Shlomai, H.; Fineberg, J.

2017-12-01

The most general frictional motion in nature involves bimaterial interfaces, when contacting bodies possess different elastic properties. Frictional motion occurs when the contacts composing the interface separating these bodies detach via propagating rupture fronts. Coupling between slip and normal stress variations is unique to bimaterial interfaces. Here we use high speed simultaneous measurements of slip velocities, real contact area and stresses to explicitly reveal this bimaterial coupling and its role in determining different classes of rupture modes and their structures. Our experiments study the rupture of a spatially extended interface formed by brittle plastics whose shear wave speeds differ by 30%. Any slip within a bimaterial interface will break the stress symmetry across the interface. One important result of this is that local values of normal stress variations at the interface couple to interface slip, `bimaterial coupling'. The sign of the coupling depends on the front propagation direction. When we consider ruptures propagating in the direction of motion of the more compliant material, the `positive' direction, slip reduces the normal stress. We focus on this direction. We show that, in this direction, interface ruptures develop from crack-like behavior at low rupture velocities, whose structure corresponds to theoretical predictions: As the ruptures accelerate towards their asymptotic speed, the structures of the strain and stress fields near the rupture tip deviate significantly from this crack-like form, and systematically sharpen to a pulse-like rupture mode called slip-pulses. We conclude with a description of slip-pulse properties.

Endocytic vesicle rupture is a conserved mechanism of cellular invasion by amyloid proteins.

PubMed

Flavin, William P; Bousset, Luc; Green, Zachary C; Chu, Yaping; Skarpathiotis, Stratos; Chaney, Michael J; Kordower, Jeffrey H; Melki, Ronald; Campbell, Edward M

2017-10-01

Numerous pathological amyloid proteins spread from cell to cell during neurodegenerative disease, facilitating the propagation of cellular pathology and disease progression. Understanding the mechanism by which disease-associated amyloid protein assemblies enter target cells and induce cellular dysfunction is, therefore, key to understanding the progressive nature of such neurodegenerative diseases. In this study, we utilized an imaging-based assay to monitor the ability of disease-associated amyloid assemblies to rupture intracellular vesicles following endocytosis. We observe that the ability to induce vesicle rupture is a common feature of α-synuclein (α-syn) assemblies, as assemblies derived from WT or familial disease-associated mutant α-syn all exhibited the ability to induce vesicle rupture. Similarly, different conformational strains of WT α-syn assemblies, but not monomeric or oligomeric forms, efficiently induced vesicle rupture following endocytosis. The ability to induce vesicle rupture was not specific to α-syn, as amyloid assemblies of tau and huntingtin Exon1 with pathologic polyglutamine repeats also exhibited the ability to induce vesicle rupture. We also observe that vesicles ruptured by α-syn are positive for the autophagic marker LC3 and can accumulate and fuse into large, intracellular structures resembling Lewy bodies in vitro. Finally, we show that the same markers of vesicle rupture surround Lewy bodies in brain sections from PD patients. These data underscore the importance of this conserved endocytic vesicle rupture event as a damaging mechanism of cellular invasion by amyloid assemblies of multiple neurodegenerative disease-associated proteins, and suggest that proteinaceous inclusions such as Lewy bodies form as a consequence of continued fusion of autophagic vesicles in cells unable to degrade ruptured vesicles and their amyloid contents.

Rupture Following Biceps-to-Triceps Tendon Transfer in Adolescents and Young Adults With Spinal Cord Injury:

PubMed Central

Merenda, Lisa A.; Rutter, Laure; Curran, Kimberly; Kozin, Scott H.

2012-01-01

Background: Tendon transfer surgery can restore elbow extension in approximately 70% of persons with tetraplegia and often results in antigravity elbow extension strength. However, we have noted an almost 15% rupture/attenuation rate. Objective: This investigation was conducted to analyze potential causes in adolescents/young adults with spinal cord injury (SCI) who experienced tendon rupture or attenuation after biceps-to-triceps transfer. Methods: Medical charts of young adults with SCI who underwent biceps-to-triceps transfer and experienced tendon rupture or attenuation were reviewed. Data collected by retrospective chart review included general demographics, surgical procedure(s), use and duration of antibiotic treatment, time from tendon transfer surgery to rupture/attenuation, and method of diagnosis. Results: Twelve subjects with tetraplegia (mean age, 19 years) who underwent biceps-to-triceps reconstruction with subsequent tendon rupture or attenuation were evaluated. Mean age at time of tendon transfer was 18 years (range, 14-21 years). A fluoroquinolone was prescribed for 42% (n=5) of subjects. Tendon rupture was noted in 67% (n=8), and attenuation was noted in 33% (n=4). Average length of time from surgery to tendon rupture/attenuation was 5.7 months (range, 3-10 months). Conclusion: Potential contributing causes of tendon rupture/attenuation after transfer include surgical technique, rehabilitation, co-contraction of the transfer, poor patient compliance, and medications. In this cohort, 5 subjects were prescribed fluoroquinolones that have a US Food and Drug Administration black box concerning tendon ruptures. Currently, all candidates for upper extremity tendon transfer reconstruction are counseled on the effects of fluoroquinolones and the potential risk for tendon rupture. PMID:23459326

Macroscopic Source Properties from Dynamic Rupture Styles in Plastic Media

NASA Astrophysics Data System (ADS)

Gabriel, A.; Ampuero, J. P.; Dalguer, L. A.; Mai, P. M.

2011-12-01

High stress concentrations at earthquake rupture fronts may generate an inelastic off-fault response at the rupture tip, leading to increased energy absorption in the damage zone. Furthermore, the induced asymmetric plastic strain field in in-plane rupture modes may produce bimaterial interfaces that can increase radiation efficiency and reduce frictional dissipation. Off-fault inelasticity thus plays an important role for realistic predictions of near-fault ground motion. Guided by our previous studies in the 2D elastic case, we perform rupture dynamics simulations including rate-and-state friction and off-fault plasticity to investigate the effects on the rupture properties. We quantitatively analyze macroscopic source properties for different rupture styles, ranging from cracks to pulses and subshear to supershear ruptures, and their transitional mechanisms. The energy dissipation due to off-fault inelasticity modifies the conditions to obtain each rupture style and alters macroscopic source properties. We examine apparent fracture energy, rupture and healing front speed, peak slip and peak slip velocity, dynamic stress drop and size of the process and plastic zones, slip and plastic seismic moment, and their connection to ground motion. This presentation focuses on the effects of rupture style and off-fault plasticity on the resulting ground motion patterns, especially on characteristic slip velocity function signatures and resulting seismic moments. We aim at developing scaling rules for equivalent elastic models, as function of background stress and frictional parameters, that may lead to improved "pseudo-dynamic" source parameterizations for ground-motion calculation. Moreover, our simulations provide quantitative relations between off-fault energy dissipation and macroscopic source properties. These relations might provide a self-consistent theoretical framework for the study of the earthquake energy balance based on observable earthquake source parameters.

Retrieving rupture history using waveform inversions in time sequence

NASA Astrophysics Data System (ADS)

Yi, L.; Xu, C.; Zhang, X.

2017-12-01

The rupture history of large earthquakes is generally regenerated using the waveform inversion through utilizing seismological waveform records. In the waveform inversion, based on the superposition principle, the rupture process is linearly parameterized. After discretizing the fault plane into sub-faults, the local source time function of each sub-fault is usually parameterized using the multi-time window method, e.g., mutual overlapped triangular functions. Then the forward waveform of each sub-fault is synthesized through convoluting the source time function with its Green function. According to the superposition principle, these forward waveforms generated from the fault plane are summarized in the recorded waveforms after aligning the arrival times. Then the slip history is retrieved using the waveform inversion method after the superposing of all forward waveforms for each correspond seismological waveform records. Apart from the isolation of these forward waveforms generated from each sub-fault, we also realize that these waveforms are gradually and sequentially superimposed in the recorded waveforms. Thus we proposed a idea that the rupture model is possibly detachable in sequent rupture times. According to the constrained waveform length method emphasized in our previous work, the length of inverted waveforms used in the waveform inversion is objectively constrained by the rupture velocity and rise time. And one essential prior condition is the predetermined fault plane that limits the duration of rupture time, which means the waveform inversion is restricted in a pre-set rupture duration time. Therefore, we proposed a strategy to inverse the rupture process sequentially using the progressively shift rupture times as the rupture front expanding in the fault plane. And we have designed a simulation inversion to test the feasibility of the method. Our test result shows the prospect of this idea that requiring furthermore investigation.

When Education Research Matters. Education Outlook, No. 1

ERIC Educational Resources Information Center

Hess, Frederick M.

2008-01-01

The tangled relationship between education research and policy has received little serious scrutiny, even as paeans to "scientifically based research" and "evidence-based practice" have become a staple of education policymaking in recent years. For all the attention devoted to the five-year-old Institute of Education Sciences, to No Child Left…

Facebook-Driven Newark Overhaul Lurches Forward

ERIC Educational Resources Information Center

Gewertz, Catherine

2010-01-01

What began as a swashbuckling move by the mayor of Newark, New Jersey, the state's governor, and a newly minted billionaire to reshape the beleaguered Newark school system has turned into a tangle of blowback and counterpunches as skeptics contend the plan would violate state law. At issue is the power-sharing arrangement proposed by the three…

Length Dependent Foam-Like Mechanical Response of Axially Indented Vertically Oriented Carbon Nanotube Arrays

DTIC Science & Technology

2011-01-01

Sands T, Xu X, Fisher T. Dendrimer -assisted controlled growth of carbon nanotubes for enhanced thermal interface conductance. Nanotechnology 2007;18...surfaces. Rev Sci Instrum 2006;77(9):095105-1–3. [11] Allaoui A, Hoa S, Evesque P, Bai J. Electronic transport in carbon nanotube tangles under compression

Citizenship, Nationalism, Human Rights and Democracy: A Tangling of Terms in the Kuwaiti Curriculum

ERIC Educational Resources Information Center

Al-Nakib, Rania

2011-01-01

Background: Citizenship, nationalism, human rights and democracy are four terms and concepts that are inextricably linked. In Kuwait, the status of citizen is based on nationality, gender and age, with women, children, naturalised citizens, expatriates and "bidoon" (stateless people) denied many freedoms, rights and services. Citizenship…

Tangled up in Blue: Boosting Mental Health Services at Community Colleges

ERIC Educational Resources Information Center

Finkel, Ed

2016-01-01

In a recent survey of 4,000 community college students, half reported experiencing a mental health condition. American College Counseling Association's (ACCA) fifth annual survey of personal and mental health counseling at community colleges provides some data from 159 professionals at two-year colleges in 41 states and Puerto Rico. Among the…

Tangled Webs: Tracing the Connections between Genes and Cognition

ERIC Educational Resources Information Center

Fisher, Simon E.

2006-01-01

The rise of molecular genetics is having a pervasive influence in a wide variety of fields, including research into neurodevelopmental disorders like dyslexia, speech and language impairments, and autism. There are many studies underway which are attempting to determine the roles of genetic factors in the aetiology of these disorders. Beyond the…

Sketches in Democracy: Notes from an Urban Classroom

ERIC Educational Resources Information Center

DeLorenzo, Lisa

2012-01-01

"Sketches of Democracy" is a captivating book that chronicles the first year in the life of a new urban high school. Based on journal entries and educational literature, this book traces the author's challenging journey toward creating a democratic community of learners within a tangle of socio-economic and political issues. An experienced public…

"A Complicated Tangle of Circumstances"

ERIC Educational Resources Information Center

Miller, Carole; Saxton, Juliana

2009-01-01

The post-modern curriculum, drawing on chaos and complexity theory, recognises the realities of a world in flux and posits that the teacher and the class are always teetering "in the midst" of chaos, "not linked by chains of causality but [by] layers of meaning, recursive dynamics, non-linear effects and chance" (Osberg 2008,…

Credit Squeeze Exposes Weaknesses in Investments

ERIC Educational Resources Information Center

Blumenstyk, Goldie; Field, Kelly

2008-01-01

This article reports that the credit crisis tying global financing systems into knots has left hundreds of colleges scrambling for cash to pay their bills and to cover the spiking interest on their debts. While it is still unclear to what extent the federal government's new $700-billion bailout package will help unwind the credit tangle, the…

The Tangled Web: Delinquency, Deception, and Parental Attachment

ERIC Educational Resources Information Center

Warr, Mark

2007-01-01

Delinquent youth display weaker attachment to their parents than do other youth, but the reasons for this remain unclear. One explanation is that delinquent youth poison their relations with parents by lying to them about their friends, behavior, whereabouts, and more. Analysis of data from the National Longitudinal Study of Adolescent Health…

The Principal's Quick-Reference Guide to School Law: Reducing Liability, Litigation, and Other Potential Legal Tangles.

ERIC Educational Resources Information Center

Dunklee, Dennis R.; Shoop, Robert J.

This book is designed to inform school administrators regarding school law. As a resource, it provides suggested, easy-to-understand guidelines for the avoidance of litigation. Subjects include preventive law and risk management; constitutional and statutory foundations of staff selection, contracting, and evaluation; negligent hiring, defamation,…

7 CFR 29.2529 - Leaf scrap.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 7 Agriculture 2 2013-01-01 2013-01-01 false Leaf scrap. 29.2529 Section 29.2529 Agriculture...-Cured Tobacco (u.s. Types 22, 23, and Foreign Type 96) § 29.2529 Leaf scrap. A byproduct of unstemmed tobacco. Leaf scrap results from handling unstemmed tobacco and consists of loose and tangled whole or...

7 CFR 29.2529 - Leaf scrap.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 7 Agriculture 2 2014-01-01 2014-01-01 false Leaf scrap. 29.2529 Section 29.2529 Agriculture...-Cured Tobacco (u.s. Types 22, 23, and Foreign Type 96) § 29.2529 Leaf scrap. A byproduct of unstemmed tobacco. Leaf scrap results from handling unstemmed tobacco and consists of loose and tangled whole or...

7 CFR 29.2529 - Leaf scrap.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 7 Agriculture 2 2012-01-01 2012-01-01 false Leaf scrap. 29.2529 Section 29.2529 Agriculture...-Cured Tobacco (u.s. Types 22, 23, and Foreign Type 96) § 29.2529 Leaf scrap. A byproduct of unstemmed tobacco. Leaf scrap results from handling unstemmed tobacco and consists of loose and tangled whole or...

7 CFR 29.2529 - Leaf scrap.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 7 Agriculture 2 2010-01-01 2010-01-01 false Leaf scrap. 29.2529 Section 29.2529 Agriculture...-Cured Tobacco (u.s. Types 22, 23, and Foreign Type 96) § 29.2529 Leaf scrap. A byproduct of unstemmed tobacco. Leaf scrap results from handling unstemmed tobacco and consists of loose and tangled whole or...

7 CFR 29.2529 - Leaf scrap.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 7 Agriculture 2 2011-01-01 2011-01-01 false Leaf scrap. 29.2529 Section 29.2529 Agriculture...-Cured Tobacco (u.s. Types 22, 23, and Foreign Type 96) § 29.2529 Leaf scrap. A byproduct of unstemmed tobacco. Leaf scrap results from handling unstemmed tobacco and consists of loose and tangled whole or...

Hard Labour and Punitive Welfare: The Unemployed Body at Work in Participatory Performance

ERIC Educational Resources Information Center

Bartley, Sarah

2017-01-01

This article addresses the performance of labour in participatory arts projects and considers the implications of such activity on perceptions of the unemployed in the UK. Utilising a combination of biopolitical and necropolitical understandings of governance and drawing on two examples of theatre practice, Tangled Feet's "One Million"…

Dietary supplementation with non-prey food enhances fitness of a predatory arthropod

USDA-ARS?s Scientific Manuscript database

Uncertainties exist about the value of non-prey food for natural enemies that are commonly food limited, and the dietary conditions where non-prey foods are beneficial for carnivorous species. We examined the nutritional role of a non-prey food using a ground dwelling, tangle web-building spider tha...

Fluorescent rhodanine-3-acetic acids visualize neurofibrillary tangles in Alzheimer's disease brains.

PubMed

Anumala, Upendra Rao; Gu, Jiamin; Lo Monte, Fabio; Kramer, Thomas; Heyny-von Haußen, Roland; Hölzer, Jana; Goetschy-Meyer, Valerie; Schön, Christian; Mall, Gerhard; Hilger, Ingrid; Czech, Christian; Herms, Jochen; Schmidt, Boris

2013-09-01

There is a high demand for the development of an imaging agent for neurofibrillary tangles (NFTs) detection in Alzheimer's diagnosis. In the present study, a series of rhodanine-3-acetic acids was synthesized and evaluated for fluorescence imaging of NFTs in brain tissues of AD patients. Five out of seven probes have shown excellent binding affinity to NFTs over amyloid plaques in the Thiazine red R displacement assay. However, the selectivity in this in vitro assay is not confirmed by the histopathological evaluation, which indicates significant differences in the binding sites in the assays. Probe 6 showed binding affinity (IC50=19nM) to tau aggregates which is the highest among this series. Probes 2, 3, 4 and 5 display IC50 values of lower than 100nM to tau aggregates to displace Thiazine red R. Evaluation of the cytotoxicity of these five probes with human liver carcinoma cells revealed that these compounds excert negligible cytotoxicity. The in vivo studies with zebrafish embryos confirmed negligible cytotoxicity at 24 and 72h post fertilization. Copyright © 2013 Elsevier Ltd. All rights reserved.

Is synaptic loss a unique hallmark of Alzheimer's disease?

PubMed Central

Scheff, Stephen W.; Neltner, Janna H.; Nelson, Peter T.

2014-01-01

Synapses may represent a key nidus for dementia including Alzheimer's disease (AD) pathogenesis. Here we review published studies and present new ideas related to the question of the specificity of synapse loss in AD. Currently, AD is defined by the regional presence of neuritic plaques and neurofibrillary tangles in the brain. The severity of involvement by those pathological hallmarks tends to correlate both with antemortem cognitive status, and also with synapse loss in multiple brain areas. Recent studies from large autopsy series have led to a new standard of excellence with regard to clinical–pathological correlation and to improved comprehension of the numerous brain diseases of the elderly. These studies have provided evidence that it is the rule rather than the exception for brains of aged individuals to demonstrate pathologies (often multiple) other than AD plaques and tangles. For many of these comorbid pathologies, the extent of synapse loss is imperfectly understood but could be substantial. These findings indicate that synapse loss is probably not a hallmark specific to AD but rather a change common to many diseases associated with dementia. PMID:24412275

Caspase-6 activity in the CA1 region of the hippocampus induces age-dependent memory impairment

PubMed Central

LeBlanc, A C; Ramcharitar, J; Afonso, V; Hamel, E; Bennett, D A; Pakavathkumar, P; Albrecht, S

2014-01-01

Active Caspase-6 is abundant in the neuropil threads, neuritic plaques and neurofibrillary tangles of Alzheimer disease brains. However, its contribution to the pathophysiology of Alzheimer disease is unclear. Here, we show that higher levels of Caspase-6 activity in the CA1 region of aged human hippocampi correlate with lower cognitive performance. To determine whether Caspase-6 activity, in the absence of plaques and tangles, is sufficient to cause memory deficits, we generated a transgenic knock-in mouse that expresses a self-activated form of human Caspase-6 in the CA1. This Caspase-6 mouse develops age-dependent spatial and episodic memory impairment. Caspase-6 induces neuronal degeneration and inflammation. We conclude that Caspase-6 activation in mouse CA1 neurons is sufficient to induce neuronal degeneration and age-dependent memory impairment. These results indicate that Caspase-6 activity in CA1 could be responsible for the lower cognitive performance of aged humans. Consequently, preventing or inhibiting Caspase-6 activity in the aged may provide an efficient novel therapeutic approach against Alzheimer disease. PMID:24413155

Exact zeros of entanglement for arbitrary rank-two mixtures derived from a geometric view of the zero polytope

NASA Astrophysics Data System (ADS)

Osterloh, Andreas

2016-12-01

Here I present a method for how intersections of a certain density matrix of rank 2 with the zero polytope can be calculated exactly. This is a purely geometrical procedure which thereby is applicable to obtaining the zeros of SL- and SU-invariant entanglement measures of arbitrary polynomial degree. I explain this method in detail for a recently unsolved problem. In particular, I show how a three-dimensional view, namely, in terms of the Bloch-sphere analogy, solves this problem immediately. To this end, I determine the zero polytope of the three-tangle, which is an exact result up to computer accuracy, and calculate upper bounds to its convex roof which are below the linearized upper bound. The zeros of the three-tangle (in this case) induced by the zero polytope (zero simplex) are exact values. I apply this procedure to a superposition of the four-qubit Greenberger-Horne-Zeilinger and W state. It can, however, be applied to every case one has under consideration, including an arbitrary polynomial convex-roof measure of entanglement and for arbitrary local dimension.

Dual action of memantine in Alzheimer disease: a hypothesis.

PubMed

Wu, Tzong-Yuan; Chen, Chih-Ping

2009-09-01

In this study, we proposed a hypothesis to explain the mechanisms of memantine action in treating Alzheimer disease (AD). Memantine may reduce the expression of amyloid precursor protein and tau protein, as well as acting as an antagonist of N-methyl-D-aspartate receptors in the brain. Two neuropathologic characteristics of AD are neuritic plaques and neurofibrillary tangles. The major molecular components of the plaques and tangles are amyloid-beta peptide and tau, respectively. Drugs able to reduce the expression of amyloid-beta and tau protein provide potential pharmaceutical treatments for AD. We found that memantine inhibited internal ribosome entry site-mediated translation initiation in COS-1 cells. This suggests that the memantine may not only inhibit neuronal excitotoxicity, but also act as an inhibitor of the internal ribosome entry site, to block the expression of amyloid precursor protein and tau in neurons. Memantine may function not only as an antagonist of N-methyl-D-aspartate receptors, but also as an inhibitor of the internal ribosome entry site to block the expression of amyloid precursor protein and tau, and so ameliorate the symptoms of AD.

KSC00padig013

NASA Image and Video Library

2000-04-22

KENNEDY SPACE CENTER, FLA. -- At left, a manipulator arm on a one-man submarine demonstrates its ability to cut tangled parachute riser lines and place a Diver Operator Plug (top right) inside a mock solid rocket booster nozzle (center). Known as DeepWorker 2000, the sub is being tested on its ability to duplicate the sometimes hazardous job United Space Alliance (USA) divers perform to recover the expended boosters in the ocean after a launch. The boosters splash down in an impact area about 140 miles east of Jacksonville and after recovery are towed back to KSC for refurbishment by the specially rigged recovery ships. DeepWorker 2000 will be used in a demonstration during retrieval operations after the upcoming STS-101 launch. The submarine pilot will demonstrate capabilities to cut tangled parachute riser lines using a manipulator arm and attach the DOP to extract water and provide flotation for the booster. DeepWorker 2000 was built by Nuytco Research Ltd., North Vancouver, British Columbia. It is 8.25 feet long, 5.75 feet high, and weighs 3,800 pounds. USA is a prime contractor to NASA for the Space Shuttle program