bluuebunny/crossref_metadata_2025 huggingface dataset:
Sphingosine-1-phosphate activates BKCa channels independently of G protein-coupled receptor in human endothelial cells
Authors: Kim Moon Young , Liang Guo Hua , Kim Ji Aee , Kim Young Ju , Oh Seikwan , Suh Suk Hyo
Published: November 2005

The effect of sphingosine-1-phosphate (S1P) on large-conductance Ca2+-activated K+ (BKCa) channels was examined in primary cultured human umbilical vein endothelial cells by measuring intracellular Ca2+ concentration ([Ca2+]i), whole cell membrane currents, and single-channel activity. In nystatin-perforated current-clamped cells, S1P hyperpolarized the membrane and simultaneously increased [Ca2+]i. [Ca2+]i and membrane potentials were strongly correlated. In whole cell clamped cells, BKCa currents were activated by increasing [Ca2+]i via cell dialysis with pipette solution, and the activated BKCa currents were further enhanced by S1P. When [Ca2+]i was buffered at 1 μM, the S1P concentration required to evoke half-maximal activation was 403 ± 13 nM. In inside-out patches, when S1P was included in the bath solution, S1P enhanced BKCa channel activity in a reversible manner and shifted the relationship between Ca2+ concentration in the bath solution and the mean open probability to the left. In whole cell clamped cells or inside-out patches loaded with guanosine 5′- O-(2-thiodiphosphate) (GDPβS; 1 mM) using a patch pipette, GDPβS application or pretreatment of cells with pertussis toxin (100 ng/ml) for 15 h did not affect S1P-induced BKCa current and channel activation. These results suggest that S1P enhances BKCa channel activity by increasing Ca2+ sensitivity. This channel activation hyperpolarizes the membrane and thereby increases Ca2+ influx through Ca2+ entry channels. Inasmuch as S1P activates BKCa channels via a mechanism independent of G protein-coupled receptors, S1P may be a component of the intracellular second messenger that is involved in Ca2+ mobilization in human endothelial cells.
Divergent kinase signaling mediates agonist-induced phosphorylation of phosphatase inhibitory proteins PHI-1 and CPI-17 in vascular smooth muscle cells
Authors: Pang Huan , Guo Zhenheng , Xie Zhongwen , Su Wen , Gong Ming C.
Published: November 2005

Phosphatase holoenzyme inhibitor (PHI)-1 is one of the newest members of the family of protein phosphatase inhibitor proteins. In isolated enzyme systems, several kinases, including PKC and rho kinase (ROCK), have been shown to phosphorylate PHI-1. However, it is largely unknown whether PHI-1 is phosphorylated in response to agonist stimulation in intact cells. We investigated this question in primary cultured rat aortic vascular smooth muscle cells (VSMCs). Using two-dimensional polyacrylamide gel electrophoresis and immunoblot, we found that there are two major PHI-1 spots under resting conditions: a minor spot with an acidic isoelectric point (pI) and a major spot with a more alkaline pI. Interestingly, U-46619, a G protein-coupled receptor agonist, caused a significant increase in the acidic spot, suggesting that it may represent a phosphorylated form of PHI-1. This was confirmed by phosphatase treatment and by a specific phospho-PHI-1 antibody. Furthermore, we found that angiotensin II, thrombin, and U-46619 increased phosphorylated PHI-1 from 9% of total PHI-1 in resting cells to 18%, 18%, and 30%, respectively. We also found that inhibition of ROCK by Y-27632 or H-1152 selectively diminished U-46619-induced CPI-17 phosphorylation, whereas it did not affect PHI-1 phosphorylation. Activation of ROCK by expressing V14RhoA selectively induced CPI-17 phosphorylation without affecting PHI-1 phosphorylation. In contrast, inhibition of PKC by GF-109203X or by PKC downregulation selectively diminished U-46619-induced PHI-1 phosphorylation without significantly affecting U-46619-induced CPI-17 phosphorylation. Activating PKC by PMA induced PHI-1 phosphorylation. Together, our results show for the first time that agonist induces PHI-1 phosphorylation in VSMCs and divergent kinase signaling couples agonist stimulation to PHI-1 and CPI-17 phosphorylation.
Evidence for Ca2+-permeable AMPA receptors in the olfactory bulb
Authors: Blakemore L. J. , Resasco M. , Mercado M. A. , Trombley P. Q.
Published: November 2005

α-Amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptors (AMPARs), a subtype of glutamate receptor, contribute to olfactory processing in the olfactory bulb (OB). These ion channels consist of various combinations of the subunits GluR1–GluR4, which bestow certain properties. For example, AMPARs that lack GluR2 are highly permeable to Ca2+and generate inwardly rectifying currents. Because increased intracellular Ca2+could trigger a host of Ca2+-dependent odor-encoding processes, we used whole cell recording as well as histological and immunocytochemical (ICC) techniques to investigate whether AMPARs on rat OB neurons flux Ca2+. Application of 1-naphthylacetyl spermine (NAS), a selective antagonist of Ca2+-permeable AMPARs (CP-AMPARs), inhibited AMPAR-mediated currents in subsets of interneurons and principal cells in cultures and slices. The addition of spermine to the electrode yielded inwardly rectifying current-voltage plots in some cells. In OB slices, olfactory nerve stimulation elicited excitatory responses in juxtaglomerular and mitral cells. Bath application of NAS with d,l-2-amino-5-phosphonovaleric acid (AP5) to isolate AMPARs suppressed the amplitudes of these synaptic responses compared with responses obtained using AP5 alone. Co2+staining, which involves the kainate-stimulated influx of Co2+through CP-AMPARs, produced diverse patterns of labeling in cultures and slices as did ICC techniques used with a GluR2-selective antibody. These results suggest that subsets of OB neurons express CP-AMPARs, including functional CP-AMPARs at synapses. Ca2+entry into cells via these receptors could influence odor encoding by modulating K+channels, N-methyl-d-aspartate receptors, and Ca2+-binding proteins, or it could facilitate synaptic vesicle fusion.
High mobility group box 1 protein interacts with multiple Toll-like receptors
Authors: Park Jong Sung , Gamboni-Robertson Fabia , He Qianbin , Svetkauskaite Daiva , Kim Jae-Yeol , Strassheim Derek , Sohn Jang-Won , Yamada Shingo , Maruyama Ikuro , Banerjee Anirban , Ishizaka Akitoshi , Abraham Edward
Published: November 2005

High mobility group box 1 (HMGB1), originally described as a DNA-binding protein, can also be released extracellularly and functions as a late mediator of inflammatory responses. Although recent reports have indicated that the receptor for advanced glycation end products (RAGE) as well as Toll-like receptor (TLR)2 and TLR4 are involved in cellular activation by HMGB1, there has been little evidence of direct association between HMGB1 and these receptors. To examine this issue, we used fluorescence resonance energy transfer (FRET) and immunoprecipitation to directly investigate cell surface interactions of HMGB1 with TLR2, TLR4, and RAGE. FRET images in RAW264.7 macrophages demonstrated association of HMGB1 with TLR2 and TLR4 but not RAGE. Transient transfections into human embryonic kidney-293 cells showed that HMGB1 induced cellular activation and NF-κB-dependent transcription through TLR2 or TLR4 but not RAGE. Coimmunoprecipitation also found interaction between HMGB1 and TLR2 as well as TLR4, but not with RAGE. These studies provide the first direct evidence that HMGB1 can interact with both TLR2 and TLR4 and also supply an explanation for the ability of HMGB1 to induce cellular activation and generate inflammatory responses that are similar to those initiated by LPS.
Macrophage Migration Inhibitory Factor Increases Neuronal Delayed Rectifier K+ Current
Authors: Matsuura Tomokazu , Sun Chengwen , Leng Lin , Kapurniotu Aphrodite , Bernhagen Jürgen , Bucala Richard , Martynyuk Anatoly E. , Sumners Colin
Published: November 2005

Macrophage migration inhibitory factor (MIF) has widespread actions in the immune, endocrine, and nervous systems. Previously, we reported that increases in the intracellular levels of MIF depress the firing of hypothalamus/brain stem neurons in culture, including the chronotropic actions of angiotensin II. The objective of this study was to investigate the effects of MIF on delayed rectifier K+ current ( IKv), one of the component currents whose activity contributes to neuronal firing. Intracellular perfusion of MIF (80 nM) into Sprague–Dawley rat neuronal cultures caused a significant increase in IKv, as measured by patch-clamp recordings. This effect was apparent by 3 min, and was maximal after 20–30 min. IKv current density (pA/pF) increased from 31.58 ± 2.36 in controls to 41.88 ± 3.76 in MIF-treated neurons (mean ± SE; n = 9; P < 0.01). MIF that had been inactivated by boiling did not alter IKv, and MIF-neutralizing antibodies abolished the action of recombinant MIF (rMIF). The stimulatory effect of MIF on IKv current density was mimicked by intracellular application of either P1S-MIF (80 nM) or the peptide MIF-(50–65) (0.8–8 μM), both of which harbor the thiol-protein oxidoreductase (TPOR) activity of the MIF molecule. Conversely, neither C60S-MIF (80 nM) nor the MIF homologue D-dopachrome tautomerase (80 nM), both of which lack TPOR activity, altered IKv. Finally, the increase in IKv produced by rMIF was abolished by the superoxide scavenger Tiron (1 mM). These studies indicate that the neuronal action of MIF includes a stimulatory action on IKv that may be mediated by a TPOR/superoxide-scavenging mechanism.
EMG Changes in Human Thenar Motor Units With Force Potentiation and Fatigue
Authors: Thomas C. K. , Johansson R. S. , Bigland-Ritchie B.
Published: November 2005

Few studies have analyzed activity-induced changes in EMG activity in individual human motor units. We studied the changes in human thenar motor unit EMG that accompany the potentiation of twitch force and fatigue of tetanic force. Single motor unit EMG and force were recorded in healthy subjects in response to selective stimulation of their motor axons within the median nerve just above the elbow. Twitches were recorded before and after a series of pulse trains delivered at frequencies that varied between 5 and 100 Hz. This stimulation induced significant increases in EMG amplitude, duration, and area. However, in relative terms, all of these EMG changes were substantially smaller than the potentiation of twitch force. Another 2 min of stimulation (13 pulses at 40 Hz each second) induced additional potentiation of EMG amplitude, duration, and area, but the tetanic force from every unit declined. Thus activity-induced changes in human thenar motor unit EMG do not indicate the alterations in force or vice versa. These data suggest that different processes underlie the changes in EMG and force that occur during human thenar motor unit activity.
Les "anciens du peuple" et saül. Temps, espace et rite de passage dans Nombres xi et 1 Samuel x
Authors: Vartejanu-Joubert Madalina
Published: November 2005

This article analyses the cultural criteria of « time » and « space » as involving in the « rituel de passage » and the way they control its outcome. We focuse on two biblical passages, Numbers xi and 1 Samuel x, which both describe the accession of the individual to a new function and the anomalies related to this change of personnality. Reading in those texts the description of a « rituel de passgae » we interpret the mention of « prophecy » as representing the « ritual mark » through which the novice accomplishes his « rebrith ».
Genre disputes and communal accusatory laments: reflections on the genre of psalm lxxxix
Authors: Mitchell Matthew W.
Published: November 2005

Psalm lxxxix has been the subject of numerous debates. Scholars have variously described it as a royal psalm, a lament, a prophetic complaint, or some combination of these genres. Genre designation is further complicated by the harsh tone of verses 39-52, traditionally explained as a redactional addition. This paper argues that Psalm lxxxix displays a marked unity through its use of covenantal, Davidic and symbolic language, and finds further clues to the psalm's genre in a Qûmran fragment (4Q236). Psalm lxxxix can still be defined as a "lament," but as fragment 4Q236 shows, it is an angry lament in which accusatory language serves as a unifying element rather than a redactional "seam".
Isaiah xxvii 7 and intertextual discourse about 'striking' in the book of Isaiah
Authors: Hibbard J. Todd
Published: November 2005

Isaiah xxvii 7 is widely regarded as one of the most obscure verses in Isaiah xxiv-xxvii, one of the latest additions to the book. After briefly dealing with the verse's syntactical issues, this article seeks to address the question of the verse's meaning using an intertextual approach. I argue that the first half of the verse evokes other texts in Isaiah about "striking", a theme introduced in the first chapter (i 5-6) and developed through Isaiah. Understood as part of an inner-Isaianic textual development, the verse makes the point that Israel has not been struck like the one who struck it (Assyria). The second half of xxvii 7, which uses the idea of "killing", makes a more immediate intertextual connection with xxvi 21. The article concludes by noting that viewed against this intertextual backdrop, the verse offers a further elaboration of xxvii 2-5(6) which depict YHWH's vineyard.
Qohélet vi 1-2: « Dieu ne permet pas … »
Authors: Maussion Marie
Published: November 2005

Qohelet vi 1-2, rather difficult to understand, tells the story of a man who can not use his belongings, although he wants to. A general first reading helps us to relate this text to other ones about the free work (work without benefits), and underlines its place in the book, just beside the fourth chorus about the happiness. A second reading shows us two key words used by Qohelet : the « glory » which suggests that there is more than the work, and the fact that God does not « allow » the man to enjoy his belongings. Consequently, one is able to find some explanations using the opposition between luxurious pleasure and honest joy.
Semantic and Perceptual Representations of Color: Evidence of a Shared Color-Naming Function
Authors: Sayim Bilge , Jameson Kimberly A. , Alvarado Nancy , Szeszel Monika
Published: November 2005

Much research on color representation and categorization has assumed that relations among color terms can be proxies for relations among color percepts. We test this assumption by comparing the mapping of color words with color appearances among different observer groups performing cognitive tasks: (1) an invariance of naming task; and (2) triad similarity judgments of color term and color appearance stimuli within and across color categories. Observer subgroups were defined by perceptual phenotype and photopigment opsin genotype analyses. Results suggest that individuals rely on at least two different representational models of color experience: one lexical, conforming to the culture's normative linguistic representation, and another individual perceptual representation organizing each observer's color sensation experiences. Additional observer subgroup analyses suggest that perceptual phenotype variation within a language group may play a greater role in the shared color naming system than previously thought. A reexamination of color naming data in view of these findings may reveal influences on color naming important to current theories.
Culture and Cognition: What is Universal about the Representation of Color Experience?
Authors: Jameson Kimberly
Published: November 2005

Existing research in color naming and categorization primarily reflects two opposing views: A Cultural Relativist view that posits color perception is greatly shaped by culturally specific language associations and perceptual learning, and a Universalist view that emphasizes panhuman shared color processing as the basis for color naming similarities within and across cultures. Recent empirical evidence finds color processing differs both within and across cultures. This divergent color processing raises new questions about the sources of previously observed cultural coherence and cross-cultural universality. The present article evaluates the relevance of individual variation on the mainstream model of color naming. It also presents an alternate view that specifies how color naming and categorization is shaped by both panhuman cognitive universals and socio-cultural evolutionary processes. This alternative view, expressed, in part, using an Interpoint Distance Model of color categorization, is compatible with new empirical results showing divergent color processing within and across cultures. It suggests that universalities in color naming and categorization may naturally arise across cultures because color language and color categories primarily reflect culturally modal linguistic mappings, and categories are shaped by universal cognitive constructs and culturally salient features of color. Thus, a shared cultural representation of color based on widely shared cognitive dimensions may be the proper foundation for universalities of color naming and categorization. Across cultures this form of representation may result from convergent responses to similar pressures on color lexicon evolution.
Focal Color Variability and Unique Hue Stimulus Variability
Authors: Kuehni Rolf
Published: November 2005

The degree to which physiology and culture have affected the formation of primitive color categories continues to be a matter of discussion. In this paper the degree of agreement between the ranges of individual color term foci for the four hue-based color categories yellow, green, blue, and red and individual choices of Munsell samples representing for the observers Hering's four unique hues is investigated. The color term focus range data are extracted from the survey results of the 110 unwritten languages of the World Color Survey, also in terms of the Munsell color order system. Agreement of approximately 90% between the two has been found, indicating the likelihood of a strong color vision system related physiological component in the formation of these four primitive hue categories.
Unique Hue Stimulus Choice: A Constraint on Hue Category Formation
Authors: Kuehni Rolf
Published: November 2005

Berlin & Kay hue-related basic color categories are compared with the ISCC-NBS system of object color categorization. Though independently derived, categories of the former form a small subset of the latter. A conjecture is proposed that explains the absence of yellow-green and blue-green basic hue categories and the potential for a violet category as the result of constraints on primitive hue category formation due to considerable variation in stimuli selected by color-normal observers as representing for them unique hues.
Face Value: The Phenomenology of Physiognomy
Authors: Cloonan Thomas
Published: November 2005

The concern of this article is to establish the difference between physiognomy and expression as it may be understood phenomenologically. The work of Merleau-Ponty founds the phenomenological appreciation of physiognomy, and Gestalt psychological studies on perceptual organization elaborate the specifics of physiognomic structure despite the naturalist assumptions of that school of psychology. Physiognomy is the organized structural specification of expression in the phenomenon that presents itself. This view is an alternative to conventional topical but nonthematic considerations on physiognomy (e.g., "face value," visual inspection, physiognomy in language perception, and facial expressiveness). Art therapy with its use of various media is a venue in which the physiognomy of clients' art products is a display of integralness or pathology. It is an immediate access to the world of the patient. The work of the Gestalt psychologist Rudolf Arnheim and of the art therapist Mala Betensky are associated with the phenomenology of Merleau-Ponty in order to advance understanding of the significance of physiognomy in experience, in behavior, and in art therapy.
World-Systems Analysis after Thirty Years: Should it Rest in Peace?
Authors: Sanderson Stephen K.
Published: November 2005

World-systems analysis has had a major impact on the social sciences over the past three decades. Although originally developed within sociology, its influence has not only been extensive in that field, but has spread to such fields as anthropology and political science as well. This article attempts a new critical assessment of the world-systems paradigm. Its major accomplishments are seen as sixfold: its insistence on understanding the modern world historically, its employment of modes of historical analysis that encompass very long periods of time ( la longue durée), its highly interdisciplinary nature, its rigorous materialism, a conception of capitalism that is broader and more useful than the traditional Marxian conception, and its situation of the current phase of globalization in its proper historical context. On the negative side, I identify five major problems: its tendency toward teleology and reification; its overemphasis on exogenous forces at the expense of endogenous ones; its misrepresentation, in its classical form, of the effect of foreign investment on the periphery; its underestimation of the developmental prospects of the periphery; and its relative helplessness in understanding the nature and collapse of state socialist societies and the future prospects of socialism. I conclude with some suggestions for rebuilding world-systems analysis.
Exploring Resistance from a Rhetorical Perspective
Authors: Symon Gillian
Published: November 2005

Contemporary accounts of resistance at work have emphasized processes of identity construction and regulation (e.g. Alvesson and Willmott 2002). Case study examinations (e.g. Knights and McCabe 2000; Ezzamel et al. 2001) have been recently extended by detailed studies of the operation of discourse at the level of talk (e.g. Dick and Cassell 2002). This paper adds to these recent accounts by providing an analysis of arguments for and against a technological change project in a UK public sector organization. The objective is to demonstrate how such arguments are constructed to achieve particular interpretations of reality while resisting others (i.e. the use of persuasive rhetoric). In the examples analysed here, rhetorical strategies included: producing a range of identities for 'the resistant', IT support staff and others; disputing the 'realness' of people, things and processes (e.g. information, participation); producing and negotiating various boundaries (e.g. we/other, production worker/support staff); and drawing on local and broader cultural discourse. In this example, we also see how 'subjectivity', 'agency' and (political) 'structures' may serve as rhetorical resources. This paper argues that the focus on counter-argument (as resistance) demonstrates the disputative, politically oriented and dialogical nature of identity construction.
Computing Pareto Optimal Coordinations on Roadmaps
Authors: Ghrist Robert , O'Kane Jason M. , LaValle Steven M.
Published: November 2005

We consider the coordination of multiple robots in a common environment, each robot having its own (distinct) roadmap. Our primary contribution is a classification of and exact algorithm for computing vector-valued (or Pareto) optima for collision-free coordination. We indicate the utility of new geometric techniques from CAT(0) geometry and give an argument that curvature bounds are the key distinguishing feature between systems for which the classification is finite and for those in which it is not.
A Simple Algorithm for Complete Motion Planning of Translating Polyhedral Robots
Authors: Varadhan Gokul , Krishnan Shankar , Sriram T. V.N. , Manocha Dinesh
Published: November 2005

We present an algorithm for complete path planning for translating polyhedral robots in three dimensions. We compute a roadmap of the free space that captures its connectivity. The roadmap is constructed without computing an explicit representation of the free space. It encodes the complete connectivity of free space and allows us to perform exact path planning. We construct a roadmap by performing a sampling of the free space in a deterministic fashion. We obtain a set of deterministic samples by generating an adaptive volumetric grid. Our algorithm is simple to implement and uses two tests: a complex cell test and a star-shaped test during sample generation. These tests can be efficiently performed on polyhedral objects using max-norm distance computation and linear programming. We demonstrate the performance of our algorithm on environments with very small narrow passages or no collision-free paths.
The Androgynous and Bisexuality in Ancient Legal Codes
Authors: Cantarella Eva
Published: November 2005

The name derives from his parentage: ‘Hermaphroditus’, son of Hermes and Aphrodite. His place of birth remains unknown, but we know where he spent his first years of life: the woods surrounding Mount Ida in Phrygia where he was brought up by the Nymphs. A normal life, like any other boy, until the age of fifteen when he decides to explore the world. He travels through Asia Minor until he reaches Caria, and the banks of a beautiful lake. A bold Nymph lives in the vicinity of the lake: Salmacis. As soon as she sees Hermaphroditus, now a handsome young man, she falls in love with him and tries various ways of seducing him - all in vain, as Hermaphroditus resists her advances. Salmacis is not discouraged. More and more determined to conquer the youth, she pretends to have given up all hope and waits for the right moment. The occasion presents itself when, naked, Hermaphroditus dives into the waters of the lake. Salmacis, who has been eagerly awaiting that moment, dives in after him and clasps him in an embrace from which he cannot free himself. An embrace of only a few seconds does not satisfy the desires of the lovestruck Nymph: she wants her body and her beloved's to become fused for the rest of eternity. She prays to the gods and the gods grant her request. Hermaphroditus and Salmacis are transformed forever into a new single being that is both male and female (the story can be found in Ovid, Metamorphosis, IV, 285).
Brain, Sex and Ideology
Authors: Vidal Catherine
Published: November 2005

Does a sexual brain exist? There is no simple answer to this question. Indeed, the brain is the origin of thoughts and that makes it different from any other organ. As such, it is both a biological and a cultural organ. Lying behind the original question is the debate between nature and culture. And in this debate, science and ideology are closely linked (Vidal and Benoit-Browaeys, 2005). The topic of brain and sex is a perfect example of this: it concerns everybody and the media love the matter. This can be seen in the following headlines, which appeared recently in the press:

‘Science proves that men and women think differently’ (International Herald Tribune, March 1995)

‘If I'm stupid, it's mummy's fault’ (le Figaro, June 1997)

‘Are homosexuals born that way?’ (Nouvel Observateur, October 1995)

‘Why do men never listen, why can't women read a map?’ (A. B. Pease, First Edition, 1999)
Study of the Defects and Water Absorption Behavior in Jute-reinforced Polymer Composites using Film Neutron Radiography
Authors: Islam M. N. , Khan M. A. , Zaman M. A.
Published: November 2005

Neutron radiography method has been adopted to study the defects and water absorption behavior in jute-reinforced polymer composites using the thermal neutron radiography facility of 3MW TRIGA MARK-II Research Reactor of Atomic Energy Research Establishment, Savar Dhaka, Bangladesh. The composite is prepared with jute fabrics and a formulated solution composed of a urethane triacrylate oligomer, reactive monomer diluents, and an additive urea under Co-60 radiation. Optical density of the neutron radiographs is adopted for measurements in both the cases. Densitometric measurements of the neutron radiographs show that in the composite, the associated solutions are diffused and exposed by dose uniformly. The water absorption of the composite with time is negligible.
Psychosocial Resources as Moderators of the Impact of Spousal Dementia Caregiving on Depression
Authors: Adams Kathryn Betts , Smyth Kathleen A. , McClendon McKee J.
Published: November 2005

This study examines the relationship of personal mastery and perceived emotional support to depressive symptoms for spousal dementia caregivers (CGs) and noncaregiver (NCG) spouses. Although it is well known that caring for a spouse with dementia is stressful and that personal mastery and emotional support may reduce stress, the authors hypothesize that these resources are more important for reducing stress in the difficult situation of dementia care than in everyday life for older persons. In bivariate comparisons, CG levels of perceived support and mastery were lower and depression was higher than for NCGs. Consistent with prior research, a hierarchical multiple regression with combined data shows that CG status was a significant predictor of depressive symptoms. A significant interaction of CG status with personal mastery indicates greater impact of mastery on depression among CGs than among NCGs. This unique finding strongly supports interventions focusing on enhancement of mastery among spousal CGs.
The Effects of Top Management Professional Development on Administrator Turnover
Authors: Castle Nicholas G. , Shugarman Lisa R.
Published: November 2005

This study examines how characteristics associated with professional development of the top management team in 406 nursing homes can affect administrator turnover. Tenure, education, and membership in a professional association are the characteristics investigated. Data used in this investigation came from a survey of nursing facilities and the 1999 On-line Survey, Certification, and Reporting system. Using logistic regression analyses, the effects of the professional development characteristics of the top management team on the turnover of administrators were examined. The average annual turnover rate of administrators was 43%. Controlling for seven organizational factors, the results are generally significant for tenure and membership in a professional association. This study shows that both aggregate and dissimilarity measures of tenure and professional association membership are important influences on administrator turnover. These results suggest that nursing home owners may want to hire top managers with strong professional membership ties or should encourage top managers to make these ties.
Differential Control of Bmal1 Circadian Transcription by REV-ERB and ROR Nuclear Receptors
Authors: Guillaumond Fabienne , Dardente Hugues , Giguère Vincent , Cermakian Nicolas
Published: November 2005

Circadian rhythms result from feedback loops involving clock genes and their protein products. In mammals, 2 orphan nuclear receptors, REV-ERBα and RORα, play important roles in the transcription of the clock gene Bmal1. The authors now considerably extend these findings with the demonstration that all members of the REV-ERB (α and β) and ROR (α, β, and γ) families repress and activate Bmal1 transcription, respectively. The authors further show that transcription of Bmal1 is the result of competition between REV-ERBs and RORs at their specific response elements (RORE). Moreover, they demonstrate that Reverb genes are similarly expressed in the thymus, skeletal muscle, and kidney, whereas Ror genes present distinct expression patterns. Thus, the results indicate that all members of the REV-ERB and ROR families are crucial components of the molecular circadian clock. Furthermore, their strikingly different patterns of expression in nervous and peripheral tissues provide important insights into functional differences between circadian clocks within the organism.
Free-Running Rhythms of Pineal Circadian Output
Authors: Liu Tiecheng , Borjigin Jimo
Published: November 2005

Circadian rhythms are self-sustaining oscillations that free-run in constant conditions with a period close to 24 h. Overt circadian rhythms have been studied mostly using onset phase as the marker for the underlying pacemaker. Using in vivo online pineal microdialysis, the authors have performed detailed analysis of free-running profiles of rat pineal secretory products, including N-acetylserotonin (NAS) and melatonin that have precisely defined onsets and offsets. When rats entrained in LD 12:12 were released into constant darkness (DD), both onset and offset phases of melatonin and NAS free-run. However, while onsets free-run with a period closer to a day (FRPon = 24-24.17 h) at the beginning, offset phases free-run with significantly larger FRPs (free-running periods) (FRPoff = 24.24-24.42 h). This asymmetric free-running of onset and offset of NAS and melatonin in DD resulted in a 60- to 120-min increase of secretion duration of both NAS and melatonin. The rate of expansion of melatonin duration was 10 to 15 min per circadian cycle. The expansion of melatonin secretion duration ended for some within 4 days, while others were still expanding by the end of 10th day in DD. These results revealed that upon release into DD, the pacemaker’s oscillation is initially driven by 2 forces, free running and decompression, before reaching a stable state of free running, and suggest that the circadian pacemaker may be an elastic structure that can decompress and compress under varying photic conditions. They also illustrate the importance of using both onset and offset of a given rhythm as phase markers, as compression/decompression, and transient disparity between FRPon and FRPoff may be a common phenomenon of the circadian pacemaker.
Shortened Seasonal Photoperiodic Cycles Accelerate Aging of the Diurnal and Circadian Locomotor Activity Rhythms in a Primate
Authors: Cayetanot F. , Van Someren E. J. W. , Perret M. , Aujard F.
Published: November 2005

The gray mouse lemur ( Microcebus murinus), a prosimian primate, exhibits seasonal rhythms strictly controlled by photoperiodic variations. Previous studies indicated that longevity can be altered by long-term acceleration of seasonal rhythms, providing a model for assessing various aspects of aging. To assess the effect of aging and accelerated aging on the circadian system of this primate, we compared the circadian rhythm of the locomotor activity in adult mouse lemurs (2-4.5 years, n = 9), aged mouse lemurs (5-9 years, n = 10), and adult mouse lemurs that had been exposed from birth to a shortened seasonal photoperiodic cycle (2-4.5 years, n = 7). Compared to adult animals, aged mouse lemurs showed a significant increase in intradaily variability and an advanced activity onset. Aging was characterized by a decrease in amplitude, with both a decrease in nocturnal activity and an increase in daytime activity. When maintained in constant dim red light, aged animals exhibited a shortening of the free-running period (22.8 ± 0.1 h) compared to adult animals (23.5 ± 0.1 h). A 3- to 5-year exposure to an accelerated seasonal photoperiodic rhythm (“annual” duration of 5 months) in accelerated mouse lemurs produced disturbances of the locomotor activity rhythm that resembled those of aged mouse lemurs, whether animals were studied in entrained or in free-running conditions. The present study demonstrated a weakened and fragmented locomotor activity rhythm during normal aging in this primate. Increasing the number of expressed seasonal cycles accelerated aging of parameters related to circadian rhythmicity in adult animals.
Are Modifications of Melatonin Circadian Rhythm in the Middle Years of Life Related to Habitual Patterns of Light Exposure?
Authors: Kawinska Anna , Dumont Marie , Selmaoui Brahim , Paquet Jean , Carrier Julie
Published: November 2005

The mechanisms underlying age-related changes in the signal from the biological clock have yet to be determined. The authors sought to determine if the phase advance of circadian melatonin rhythm during the middle years of life is related to different patterns of habitual light exposure. Forty-one healthy subjects between the ages of 22 and 58 y were studied. Habitual light exposure was measured by a wrist monitor for 7 days. Participants underwent a 25-h constant routine. They provided saliva samples every 30 min, and melatonin concentration was determined by radioimmunoassay to assess salivary dim light melatonin onset (S-DLMO1.3). Aging was associated with earlier S-DLMO1.3. Increasing age was not related to the time spent at different light intensities. However, it was associated with lower percentage of light exposure during the night (between 0200-0400, 0600-0700, and 2300-2400 h) and with higher percentage of light exposure in the morning (between 0800-1100 h). Earlier S-DLMO1.3 was associated with lower percentage of light exposure early on in the night (between 2200-0000, 0000-0100, and 0200-0300 h) as well as in the afternoon (between 1500-1600 h) and with higher percentage of light exposure in the morning (between 0800-1100 h). When the effects of age were controlled, there was no significant relationship between S-DLMO1.3 and percentages of light exposure. Yet increasing age was associated with earlier S-DLMO1.3 regardless of light exposure patterns. Earlier habitual wake time explained the earlier light exposure patterns of older subjects. Both habitual wake time and age contributed to the prediction of S-DLMO1.3. The results suggest a phase advance of circadian rhythms in the middle years of life. Whereas a clear change in habitual light exposure patterns was associated with aging and with shifts in S-DLMO1.3, it did not explain entirely the age-related advance of melatonin circadian phase.
Suitable Materials for Soft Tissue Reconstruction: In Vitro Studies of Cell – Triblock Copolymer Interactions
Authors: Mattioli-Belmonte Monica , Biagini Graziella , Lucarini Guendalina , Virgili Laura , Gabbanelli Francesca , Amati Silvana , Cecchet Francesca , Albertsson Ann-Christine , Finne Anna , Andronova Natalia
Published: November 2005

Keratinocytes and fibroblasts have been grown onto a series of triblock copolymers based on 1,5-dioxepan-2-one (DXO) and L-lactide (LLA). The molar ratio of DXO and LLA were varied in the copolymers. This resulted in different degrees of hydrophilicity, which in turn influenced the cell growth. On these surfaces, the morphological appearance of the cells with their cell movements and growth were investigated by means of scanning electron microscopy, time-lapse videomicroscopy and immunohistochemistry. All results clearly showed that the keratinocytes and fibroblasts adhered best to the most hydrophilic copolymers. A majority of the keratinocytes seeded on the most hydrophilic copolymer also presented a polarized morphology indicating a migration tendency. The cell growth onto these materials are interesting since a possible application for these unique materials is as polymeric membranes for guided cutaneous and/or periodontal tissue generation.
Cholesterol Tethered Poly(DL-Lactic Acid) for Promoting Osteoblast Attachment and Growth
Authors: Yu Guanhua , Ji Jian , Shen Jiacong
Published: November 2005

In poly(DL-lactic acid)-cholesterol oligomers (LC), a novel cholesterol modified poly(DL-lactic acid) (PLA), was synthesized via bulk polymerization of DL-lactide using cholesterol initiator. Gel permeation chromatography (GPC) and 1H nuclear magnetic resonance spectroscopy (1H-NMR) results indicated a narrow molecular weight distribution of poly (DL-lactic acid)-cholesterol oligomers (LC). Mouse MC3T3 osteoblast-like cells were selected as a model system to test the cell behavior of cholesterol modified PLA substrates. The osteoblast attachment, proliferation, and viability revealed that the cholesterol modified PLA was significantly osteoblast compatible and may have potential as a bone tissue engineering material.
The Influence of Process and Material Variables on the Surface Properties of Polystyrene Matrix Reinforced with Silica Sand
Authors: Jalham Issam S.
Published: November 2005

The surface properties of polymer matrix composite materials reinforced with Jordanian silica sand and cement subjected to abrasive wear has been studied in this investigation. Process variables, such as velocity, load, and time and material variables, such as volume fraction of the reinforcement and particle size are studied using weight loss measurements. Wear mechanisms responsible for the observed variation in wear rate are also studied using a scanning electron microscope. It is concluded that the introduction of SiO2 hard particles significantly increases the abrasive wear resistance of polystyrene. The higher each of the process variables (load, velocity, and time), the higher the dimensionless wear rate, and the difference between the highest and the lowest wear rates decreases as the volume fraction content and the particle size increase. The higher each of the material variables (reinforcement content and particle size), the lesser the wear rate for fixed process conditions. It is also found that abrasive wear of SiO2-reinforced polymers occurs due to three wear mechanisms: microploughing, microcutting, and microcracking.
Individual and Collective Identities of the Beijing Democracy Wall Movement Activists, 1978–1981
Authors: Paltemaa Lauri
Published: November 2005

Drawing on the new social movement approach, this study focuses on the construction and uses of collective and individual identities in the Beijing Democracy Movement (1978–1981). The movement's mainstream constructed a progressive Marxist identity and its individual participants used it to prove the movement's historical necessity and justify its democratic agenda. Combined with the related identity of socialist citizens, the proponents defended the movement against adversaries from without and the right-wing minority within. It is argued here that the way the Democracy Movement activists defined their collective identity offered them a progressive Marxist platform to champion their cause. This collective identity not only precluded confrontational opposition to the Communist Party, but also enabled a more constructive use of both classical Marxist and Western democratic thinking in the movement's agenda.
Orphans of the State
Authors: Goldstein Daniel M.
Published: November 2005

In an urban barrio on the outskirts of a Bolivian city, the municipal government engages in a variety of techniques to regulate and manage the illegal settlers and the lands they occupy on the urban periphery. These forms of governmentality are underscored by a paternalist discourse that enjoins barrio residents to embrace urban inclusion as part of a generalized urban Bolivian family. Barrio residents desire such inclusion as a path to citizenship and the socioeconomic rights that such belonging entails, but are skeptical of paternalist rhetoric and the claims of Bolivian politicians to be 'good fathers' to their barrio children. This article examines the engagement between municipal leaders and barrio residents in the struggle to subject one urban neighborhood to state authority.
A Gift of Whale Meat
Authors: Lundberg Anita
Published: November 2005

This article arises from a performance of the exchange of whale meat as experienced during ethnographic fieldwork in the subsistence whale hunting village of Lamalera, Eastern Indonesia. The animist-Catholic beliefs of Lamalerans serve to sustain this ancestral ritual. Underlying orthodox western analyses of gift and exchange is a notion of economics based on a principle of scarcity. The article demonstrates how this assumption is associated with the psychoanalytic fear of lack, and offers an alternative reading of gift and exchange informed by: feminist theories of an economy of excess; Confucian notions of the ceremonial; and Buddhist and Taoist philosophies of no-thing as the space of never-ending potential.
System Identification Technique for Active Helicopter Rotors
Authors: Shin Sang Joon , Cesnik Carlos E. S. , Hall Steven R.
Published: November 2005

System identification methodology is developed for a linear time-periodic (LTP) system and applied to an experimental setup of an integrally twist-actuated helicopter rotor blade. Identification is conducted for a controller design, which alleviates vibratory loads induced in forward flight. Since a rotor in forward flight is a time-periodic system due to the aerodynamic environment varying once per rotation, the adopted methodology requires determination of the multicomponent harmonic transfer functions. A simplified identification formula is also derived for a linear time-invariant (LTI) system, such as a rotor system in hover. The latter approach gives another estimate of the primary component among the harmonic transfer functions. The identification experiment is conducted at NASA Langley Transonic Dynamics Tunnel. The magnitude of the higher-order harmonic transfer functions is observed to be small in the frequency range of interest when compared with that of the primary component. This indicates that the present active rotor system may be regarded as a LTI system under the level flight conditions considered. Results obtained in system identification are interpreted in terms of the closed-loop controller design.
Vibration Control of a Structural System Using Magneto-Rheological Fluid Mount
Authors: Hong Sung-Ryong , Choi Seung-Bok
Published: November 2005

In this work, a mixed mode-type magneto-rheological fluid mount (MR mount in short) is devised by considering the nondimensional formulation of Bingham plastic flow, and applied to vibration control of a structural system subjected to external excitations. The structural system consists of a vibrating mass, semi-active MR fluid mount, and passive rubber mounts. The MR mount is installed on the beam structure as a semi-active actuator and supports the vibrating mass, while the flexible beam structure is supported by two passive rubber mounts. After verifying the field-dependent damping force characteristics of the MR mount, the governing equation of the structural system is derived in the modal coordinate and rewritten as a state space control model. The linear quadratic Gaussian (LQG) controller is then formulated in order to attenuate vibration of the structural system. The LQG controller is experimentally realized and control responses such as accelerations and transmitted forces of the structural system are presented in the frequency domain.
Impact Damage Detection in Composite Laminates Using PVDF and PZT Sensor Signals
Authors: Kim In-Gul , Lee Hong-Young , Kim Jin-Won
Published: November 2005

Low-velocity impact damage is a major concern in the design of structures made of composite materials, because impact damage is hidden and cannot be detected by visual inspection. Piezoelectric sensors can be used to detect variations in structural and material properties for structural health monitoring. In this study, polyvinylidene flouride (PVDF) and lead zirconate titanate (PZT) sensors are used for monitoring impact damage initiation and propagation in composite laminates to illustrate this potential benefit. Several tests for monitoring the stress wave signals including acoustic emission due to failure modes, such as matrix cracking, delamination, and fiber breakage are performed. A series of impact tests at various impact energies by changing the impact mass and height is performed on the instrumented drop weight impact tester. The wavelet transform (WT) and short time fourier transform (STFT) are used to decompose the piezoelectric sensor signals in this study. Test results show that the particular waveform of sensor signals implying the damage initiation and propagation are detected above the damage initiation impact energy. It is found that both PZT and PVDF sensors can be used to detect the impact damage.