bluuebunny/crossref_metadata_2025 huggingface dataset:
Polymer–filler interactions in sol–gel derived polymer/silica hybrid nanocomposites
Authors: Bandyopadhyay Abhijit , de Sarkar Mousumi , Bhowmick Anil K.
Published: July 2005

The effect of polymer–filler interaction on solvent swelling and dynamic mechanical properties of the sol–gel derived acrylic rubber (ACM)/silica, epoxidized natural rubber (ENR)/silica, and poly (vinyl alcohol) (PVA)/silica hybrid nanocomposites has been described for the first time. Tetraethoxysilane (TEOS) at three different concentrations (10, 30, and 50 wt %) was used as the precursor for in situ silica generation. Equilibrium swelling of the hybrid nanocomposites in respective solvents at ambient condition showed highest volume fraction of the polymer in the swollen gel in PVA/silica system and least in ACM/silica, with ENR/silica recording an intermediate value. The Kraus constant (C) also followed a similar trend. In dynamic mechanical analysis, the storage modulus dropped at higher strain (>1%), which indicated disengagement of polymer segments from the filler surfaces. This drop was maximum in ACM/silica, intermediate in ENR/silica, and minimum in PVA/silica, both at 50 and 70 °C. The drop in modulus with theoretical volume fraction of silica (ϕ) was interpreted with the help of a Power law model ΔE′ = a1ϕ, where a1 was a constant and b1 was primarily a filler attachment parameter. Strain dependence of loss modulus was observed in ACM/silica hybrid nanocomposites, while ENR/silica and PVA/silica nanocomposites showed almost strain‐independent behavior. The storage modulus showed sharp increase with increasing frequency in ACM/silica system, while that was lower in both ENR/silica (at higher frequency) and PVA/silica systems (in the entire frequency spectrum). The increase in modulus with ϕ also followed similar model ΔE′ = a2ϕ proposed in the strain sweep mode. © 2005 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 43: 2399–2412, 2005
Cover Picture: Hybrid Microstructures from Aligned Carbon Nanotubes and Silica Particles (Small 8‐9/2005)
Authors: Agrawal Saurabh , Kumar Ashavani , Frederick Matthew J. , Ramanath Ganapathiraman
Published: July 2005

The cover picture illustrates new possibilities for integrating nanostructures of different dimensionalities into larger‐scale architectures. The foreground collage shows hybrid microstructures of vertically aligned carbon nanotubes, grown by chemical vapor deposition on close‐packed assemblies of silica microparticles; such an assembly is depicted in the background. For more information, please read the Communication “Hybrid Microstructures from Aligned Carbon Nanotubes and Silica Particles” by G. Ramanath and co‐workers on page 823 ff.
In situ study of K+ transport into the vacuole of Saccharomyces cerevisiae
Authors: Martínez‐Muñoz Gloria A. , Peña Antonio
Published: July 2005

Permeable spheroplasts were prepared from two strains of Saccharomyces cerevisiae by incubating with zymolyase without a permeabilizing agent. The loss of the plasma membrane barrier was confirmed by the nucleotide release, the activity of glucose 6‐phosphate dehydrogenase with external substrates and by the effects on respiration of mitochondrial substrates and ADP. Mitochondrial integrity was maintained, as shown by respiration with lactate, pyruvate, glucose and ethanol, and its acceleration by ADP showed a coupled respiration. Potassium uptake into the vacuole was measured with a selective electrode and found to be taken up effectively by spheroplasts only in the presence of Mg‐ATP; it was reverted by CCCP and PCP and inhibited by bafilomycin A1, but not by sodium vanadate or sodium azide. Potassium ions did not alter ΔΨ of the vacuole, followed with oxonol V, but caused vacuolar alkalinization, as followed with pyranine. The increase of vacuolar pH was non‐selective and observed at 50–200 mM of several monovalent cations. Isolated vacuoles with pyranine inside showed similar changes of the internal pH in the presence of KCl. Results indicate that some strains do not require a permeabilizing agent to directly access the vacuole in spheroplasts prepared with zymolyase. The hypothesis about the existence of a K+/H+ antiporter in the vacuolar membrane of S. cerevisiae is discussed. Copyright © 2005 John Wiley & Sons, Ltd.
Cutaneovisceral Angiomatosis with Thrombocytopenia
Authors: Prasad Vinay , Fishman Steven J. , Mulliken John B. , Fox Victor L. , Liang Marilyn G. , Klement Giannoula , Kieran Mark W. , Burrows Patricia E. , Waltz David A. , Powell Julie , Dubois Josée , Levy Moise L. , Perez-Atayde Antonio R. , Kozakewich Harry P W.
Published: July 2005

We describe 10 children with multiple vascular lesions of the skin and gastrointestinal tract associated with sustained, minor thrombocytopenia. In some children, there was involvement of the lung (n = 5), bone (n = 2), liver (n = 1), spleen (n = 1), and muscle (n = 1). The cutaneous lesions were congenital, multifocal, discrete, red-brown and variably blue macules and papules; in 3 children, a large dominant plaque was also present. All children developed hematemesis and/or melena and endoscopic evaluation revealed several to numerous small mucosal lesions that involved all levels of the gastrointestinal tract. Three of 5 children with pulmonary nodules had cough and 1 also had hemoptysis. Biopsies of cutaneous, gastrointestinal, and pulmonary lesions showed thin-walled, blood-filled vascular channels and variable endothelial hyperplasia. The endothelial nuclei were elongated, round, crescentic, or hobnailed. Cytoplasmic and extracellular periodic acid-Schiff positive deposits were often present in the zones of endothelial hyperplasia. The platelets were small in some children, suggesting a primary defect, possibly accounting for the thrombocytopenia. Gastrointestinal hemorrhage and hemoptysis required antiangiogenic therapy. The constellation of findings defines a congenital proliferative disorder of blood vessels with a distinctive microscopic appearance. We have termed this relatively indolent or slowly progressive disorder cutaneovisceral angiomatosis with thrombocytopenia because this designation incorporates its major clinical and histopathologic features.
PHI‐1 induced enhancement of myosin phosphorylation in chicken smooth muscle
Authors: El-Touhky Amr , Given Allison M. , Cochard Audrey , Brozovich Frank V.
Published: July 2005

Herein, we provide evidence that in chicken smooth muscle, G‐protein stimulation by a Rho‐kinase pathway leads to an increase in myosin light chain phosphorylation. Additionally, G‐protein stimulation did not increase MYPT1 phosphorylation at Thr695 or Thr850, and CPI‐17, was not expressed in chicken smooth muscle. However, PHI‐1 was present in chicken smooth muscle tissues. Both agonist and GTPγS stimulation result in an increase in PHI‐1 phosphorylation, which is inhibited by inhibitors to both Rho‐kinase (Y‐27632) and (PKC) GF109203x. These data suggest that PHI‐1 may act as a CPI‐17 analog in chicken smooth muscle and inhibit myosin phosphatase activity during G‐protein stimulation to produce Ca2+ sensitization.
The first crystal structure of a family 31 carbohydrate‐binding module with affinity to β‐1,3‐xylan
Authors: Hashimoto Hiroshi , Tamai Youichi , Okazaki Fumiyoshi , Tamaru Yutaka , Shimizu Toshiyuki , Araki Toshiyoshi , Sato Mamoru
Published: July 2005

Here, we present the crystal structure of the family 31 carbohydrate‐binding module (CBM) of β‐1,3‐xylanase from Alcaligenes sp. strain XY‐234 (AlcCBM31) determined at a resolution of 1.25 Å. The AlcCBM31 shows affinity with only β‐1,3‐xylan. The AlcCBM31 molecule makes a β‐sandwich structure composed of eight β‐strands with a typical immunoglobulin fold and contains two intra‐molecular disulfide bonds. The folding topology of AlcCBM31 differs from that of the large majority of other CBMs, in which eight β‐strands comprise a β‐sandwich structure with a typical jelly‐roll fold. AlcCBM31 shows structural similarity with CBM structures of family 34 and family 9, which also adopt structures based on immunoglobulin folds.
The leucine 10 residue in the pleckstrin homology domain of ceramide kinase is crucial for its catalytic activity
Authors: Kim Tack-Joong , Mitsutake Susumu , Kato Mariko , Igarashi Yasuyuki
Published: July 2005

Ceramide kinase (CERK) converts ceramide (Cer) to ceramide‐1‐phosphate (C1P), a newly recognized bioactive molecule capable of regulating diverse cellular functions. The N‐terminus of the CERK protein encompasses a sequence motif known as a pleckstrin homology (PH) domain. However, little is known regarding the functional roles of this domain in CERK. In this study, we have demonstrated that the PH domain of CERK is essential for its enzyme activity. Using site‐directed mutagenesis, we have further determined that Leu10 in the PH domain has an important role in CERK activity. Replacing this residue with a neutral alanine or isoleucine, caused a dramatic decrease in CERK activity to 1% and 29%, respectively, compared to CERK, but had no effect on substrate affinity. The study presented here suggests that the PH domain of CERK is not only indispensable for its activity but also act as a regulator of CERK activity.
Control of the light harvesting function of chloroplast membranes: The LHCII‐aggregation model for non‐photochemical quenching
Authors: Horton Peter , Wentworth Mark , Ruban Alexander
Published: July 2005

Dissipation of excess excitation energy within the photosystem II light‐harvesting antenna (LHCII) by non‐photochemical quenching (NPQ) is an important photoprotective process in plants. An update to a hypothesis for the mechanism of NPQ [FEBS Letters 292, 1991] is presented. The impact of recent advances in understanding the structure, organisation and photophysics of LHCII is assessed. We show possible locations of the predicted regulatory and quenching pigment‐binding sites in the structural model of the major LHCII. We suggest that NPQ is a highly regulated concerted response of the organised thylakoid macrostructure, which can include different mechanisms and sites at different times.
A Fixation with Floating: The Politics of Canada's Exchange Rate Regime
Authors: Helleiner Eric
Published: July 2005

Abstract.Since the 1930s, Canadian policy makers have demonstrated an unusually strong commitment to a floating exchange rate regime. A fixed exchange rate regime was embraced for only two brief periods between 1939–1950 and 1962–1970. This article examines the political basis of Canada's longstanding “fixation with floating,” an issue that is unexplored in existing scholarly literature. Drawing on the growing literature examining the politics of exchange rate regimes, the article shows how Canada's longstanding commitment to floating has stemmed from a combination of distinct domestic private economic interests, the beliefs of state policy makers, and the unique nature of the US-Canada relationship.

Résumé.Depuis les années 1930, les responsables de la politique monétaire canadienne ont manifesté une prédilection soutenue pour un taux de change flottant. Le pays n'a connu de taux de change fixe que pendant deux courtes périodes, de 1939 à 1950 et de 1962 à 1970. Cet article examine les fondements politiques de cette préférence, sujet qui reste inexploré dans la littérature existante. S'inspirant des travaux de plus en plus nombreux sur la politique des taux de change, l'article démontre que la source politique de cette préférence pour un taux de change flottant réside dans les intérêts économiques des entreprises, les convictions des décisionnaires et la nature unique de la relation entre le Canada et les États-Unis.
Informal Governance in the European Union
Authors: Schmidtke Oliver
Published: July 2005

Informal Governance in the European Union, Christiansen, Thomas and
Simona Piattoni, eds., Celtenham (UK) and Northampton, MA (USA): Edward
Elgar, 2003, pp. viii, 274.

The nature of governance in the European Union (EU), the production of
authoritative decisions through a plurality of actors and institutional
arrangements, has been at the centre of recent scholarly debates. While at
first sight many of its institutions resemble their national counterparts
the EU seems to have established a system of governance sui
generis with modes of decision-making that reflect the distinct
institutional distribution of power and the complex multi-level game of
accommodating interests in the regional, national and European arena.
Thomas Christiansen and Simona Piattoni have focused on one critical
aspect of this evolving mode of decision-making, namely, the role of
informal governance. It is defined as the operation of networks and actors
pursuing common goals through regular, though not codified and not
publicly sanctioned exchanges in the institutional context of the EU.
Comparative Constitutionalism and Good Governance in the
Commonwealth: An Eastern and Southern African Perspective
Authors: Shaw Timothy M
Published: July 2005

Comparative Constitutionalism and Good Governance in the Commonwealth:
An Eastern and Southern African Perspective, John Hatchard, Muna Ndulo and
Peter Slinn, Cambridge: Cambridge University Press, 2004, pp. xxv, 361

This is a magisterial tome in both substance and style. It is
comprehensive, almost encyclopaedic; it also presents the perspective of
“constitutional lawyers” (4), at least until the
“retreat” towards the political science in the concluding,
thirteenth chapter (310). Reflective of their trade, the trio of authors
include lists of cases, constitutions, statutes and other instruments,
with page references, as well as a comprehensive index of almost 20 pages.
The volume presents the significant conceptual advances in comparative
constitutionalism in anglophone Africa since independence, including
democratic pressures towards “good governance” advanced
through the Commonwealth nexus (1); but it also comes to lament the
continuing existential constraints on “constitutional
governance” (308). It offers welcome comparative analysis of a dozen
countries and myriad regimes over four decades.
Qui sommes-nous ? Identité nationale et choc des
cultures.
Authors: Caron Jean-François
Published: July 2005

Qui sommes-nous ? Identité nationale et choc des cultures.,
Samuel P. Huntington., Paris : Odile Jacob, 2004, 397 pages.

La mondialisation a eu des retentissements importants sur les
identités nationales. En effet, les progrès des
communications et l'accélération des migrations ont
favorisé un élargissement des contacts entre individus de
cultures et de religions différentes et le développement
d'identités supranationales. À l'inverse, la
crainte de se noyer dans un monde global où les identités
éclatent et se fusionnent peut également susciter un
désir de se redéfinir à une échelle plus
intime. Autrement dit, la formulation classique de l'identité
nationale est présentement attaquée de toutes parts et est
devenue un problème mondial qui touche toutes les nations du
monde.
Representation and Democratic Theory
Authors: Fierlbeck Katherine
Published: July 2005

Representation and Democratic Theory, David Laycock, ed., Vancouver:
UBC Press, 2004, pp. 224

Debates over minority rights and identity theory are irreducibly
connected to issues of representation and citizenship. But while
discussions in the past decade have focused on the philosophical
justifications for a discrete set of rights for cultural minorities, there
have been fewer efforts made to understand the impact of this demand upon
conceptions of representation per se.
Mondialisation, économie sociale, développement local
et solidarité internationale.
Authors: Tremblay, Diane-Gabrielle
Published: July 2005

Mondialisation, économie sociale, développement local et
solidarité internationale., Louis Favreau et Lucie
Fréchette., Sainte-Foy : Presses de l'Université du
Québec, 2002, 251 p.

Sujet à la mode que celui de la mondialisation! Le voici
abordé sous un angle un peu différent, qui allie les
thèmes de l'économie sociale, du développement
local et de la solidarité internationale. Ce dernier thème
est plus souvent associé à la mondialisation, alors que les
deux autres le sont moins.
Private Power and Global Authority: Transnational Merchant Law in
the Global Political Economy
Authors: Harmes Adam
Published: July 2005

Private Power and Global Authority: Transnational Merchant Law in the
Global Political Economy, A. Claire Cutler, Cambridge Studies in
International Relations; Cambridge: Cambridge University Press, 2003, pp.
xiv, 306

In Private Power and Global Authority, Claire Cutler presents
a theoretically rich and historically detailed account of the
interrelationship between transnational merchant law and broader patterns
of restructuring in the global political economy. More specifically, she
draws upon an historical materialist framework to demonstrate how
“fundamental transformations in global power and authority are
enhancing the significance of the private sphere in both the creation and
enforcement of international commercial law” (1). In doing so,
Cutler reveals the power relations and political implications inherent to
this seemingly functional realm. At the same time, she looks through the
other end of the telescope to show the broadly constitutive role that
transnational merchant law has played in the transformation and
legitimation of the emerging neoliberal order. In this sense, the changes
that Cutler identifies in transnational merchant law both reflect, and
help to constitute, broader changes in the global political economy.
Characterization of manganese use efficiency in UK wheat cultivars grown in a solution culture system and in the field
Authors: JIANG W. Z. , IRELAND C. R.
Published: July 2005

The aim of the research was to describe and characterize the physiological basis of Mn use efficiency among a range of old and modern UK wheat cultivars grown in Mn-depleted solution culture and to ascertain whether the existence of Mn use efficiency conferred a yield advantage under manganese stress conditions in the field. Results of solution culture experiments demonstrated that the old spring wheat cv. Maris Butler is relatively Mn efficient when grown in Mn-deficient conditions in comparison with both a modern winter wheat, cv. Claire, and a modern spring wheat, cv. Paragon. The mean dry weight gain of plants of cv. Maris Butler grown in Mn-depleted nutrient solution was 0·49 of that shown by plants in Mn-sufficient culture, whereas in cvs. Paragon and Claire the equivalent values were 0·38 and 0·21 respectively. When grown in Mn-deficient soil in a farm-based field trial, cv. Maris Butler showed significantly improved (P<0·05) dry matter accumulation and grain yield compared with other spring wheats including cv. Paragon. There was no significant variation in leaf Mn content between the cultivars examined, either under sufficient or depleted Mn supply; however, cv. Maris Butler showed both a relatively high maximum light-saturated rate of photosynthesis and a high photosynthetic apparent quantum yield (based on O2 evolution) when grown under Mn deficiency. It is argued that the apparent Mn use efficiency of cv. Maris Butler is related to superior internal utilization of Mn, resulting in an increased photosynthetic photosytem II efficiency rather than improved Mn uptake and accumulation. The results suggest that the wheat cultivar Maris Butler may provide a potentially useful source of parental material for future crop improvement programmes designed to produce wheat lines resistant to depleted Mn supply.
Genetic variability of a Criollo cattle population under conservation
Authors: MELUCCI L. M. , DÍAZ C. , MEZZADRA C. A.
Published: July 2005

The active germplasm Bank of the Integrated Unit (Facultad de Ciencias Agrarias, Unversidad Nacional de Mar del Plata and the Experimental Station of INTA) at Balcarce, keeps both in vivo (live herd) and in vitro Criollo Cattle (samples of semen and embryos cryogenically), with the aim of preserving genetic variability for potential future use. Parameters based on probable origin of genes, on population size and on the estimation of components of (co)variances for birth and weaning weights were estimated to evaluate the genetic variability of the material contained in the Bank. The information available came from 667 individuals, of which 84 had unknown parents, and 142 half-founders (only one parent known), having a mean number of births per year of 24 calves from four different sires. AI was performed during the mating season almost every year. The evolution of effective number of founders (fe), effective number of ancestors (fa), effective number of founder genomes (Ng) and the ratio fe/fa over different periods from the creation of the Bank, were analysed. Annual increase of inbreeding coefficient (F) was 0·2% and the effective population size (Ne) was estimated as 23, 14 and 25 individuals for the periods defined by years 1978–82, 1983–87 and 1993–97, respectively. The ratio fe/fa was higher in the years where the ratio number of sires/number of dams was lower, indicating that the impact of the effective number of sires is more important than the effective number of females in generating genetic bottlenecks. When the reference population was taken for the period 1989–97, 16·45 out of the 85·63 founders of the population made contributions not explained by other ancestors, but if possible losses of genomes due to genetic drift are considered, the number of genomes still present was reduced to 9·09 indicating a possible narrow genetic bottleneck in the last period. The Ng/fe ratio was 0·11, 0·10 and 0·11 for the reference populations defined by years 1989–92, 1993–97 and 1989–97, respectively. The main objective in germplasm conservation programmes should be the maintenance of genetic variability. Thus, matings in the population under conservation should be designed in order to mate those animals that maximize the effective number of genome founders (Ng) to avoid losses due to genetic drift.
Rules work on one representation; similarity compares two representations
Authors: Bailey Todd M.
Published: July 2005

Rules and similarity refer to qualitatively different processes. The classification of a stimulus by rules involves abstract and usually domain-specific knowledge operating primarily on the target representation. In contrast, similarity is a relation between the target representation and another representation of the same type. It is also useful to distinguish associationist processes as a third type of cognitive process.
Sleep is optimizing
Authors: Clarke Thomas L.
Published: July 2005

It is suggested that Walker's consolidation-based enhancement of memory during REM sleep corresponds to the simulated annealing technique used for function optimization, and that robotic and AI design could benefit from inclusion of a deliberate REM-like memory optimization phase.
Instantiated rules and abstract analogy: Not a continuum of similarity
Authors: Brooks Lee R. , Hannah Samuel D.
Published: July 2005

We agree that treating rules and similarity as dichotomous opposites is unproductive. However, describing all categorization operations as a continuum of varied similarity process obscures a multidimensional contrast. We describe two processes, instantiated rules and abstract analogy, both of which have aspects of rules and similarity, and question whether they can be compared informatively as points on a continuum.
What is consolidated during sleep-dependent motor skill learning?
Authors: Finelli Luca A. , Sejnowski Terrence J.
Published: July 2005

Learning procedural skills involves improvement in speed and accuracy. Walker proposes two stages of memory consolidation: enhancement, which requires sleep, and stabilization, which does not require sleep. Speed improvement for a motor learning task but not accuracy occurs after sleep-dependent enhancement. We discuss this finding in the context of computational models and underlying sleep mechanisms.
Two types of thought: Evidence from aphasia
Authors: Davidoff Jules
Published: July 2005

Evidence from aphasia is considered that leads to a distinction between abstract and concrete thought processes and hence for a distinction between rules and similarity. It is argued that perceptual classification is inherently a rule-following procedure and these rules are unable to be followed when a patient has difficulty with name comprehension and retrieval.
Sleep and memory: Definitions, terminology, models, and predictions?
Authors: Foster Jonathan K. , Wilson Andrew C.
Published: July 2005

In this target article, Walker seeks to clarify the current state of knowledge regarding sleep and memory. Walker's review represents an impressively heuristic attempt to synthesize the relevant literature. In this commentary, we question the focus on procedural memory and the use of the term “consolidation,” and we consider the extent to which empirically testable predictions can be derived from Walker's model.
Consolidating consolidation? Sleep stages, memory systems, and procedures
Authors: Groeger John A. , Dijk Derk-Jan
Published: July 2005

We argue that by neglecting the fact that procedural memory may also have episodic qualities, and by considering only a systems approach to memory, Walker's account of consolidation of learning during subsequent sleep ignores alternative accounts of how sleep stages may be interdependent. We also question the proposition that sleep-based consolidation largely bypasses hippocampal structures.
Neurosignals – Incorporating CNS electrophysiology into cognitive process
Authors: Pagel James F.
Published: July 2005

This commentary reviews electrophysiological research suggesting that oscillatory electrical potentials recorded by the EEG could have function at cellular and DNA levels. Evidence supporting the potential functional significance of sleep-state-specific frequencies includes psychoactive neurochemical alteration of CNS electrophysiology, and sleep-state-specific alteration of dreaming. As Walker proposes, physiologic electrical fields are likely to have a functional role in the consolidation of memory.
Is this what the debate on rules was about?
Authors: Hahn Ulrike
Published: July 2005

The key weakness of the proposed distinction between rules and similarity is that it effectively converts what was previously seen as a consequence of rule or similarity-based processing, into a definition of rule and similarity themselves – evidence is elevated into a conceptual distinction. This conflicts with fundamental intuitions about processes and erodes the relevance of the debate across cognitive science.
Illuminating reasoning and categorization
Authors: Heit Evan , Hayes Brett K.
Published: July 2005

The proposal regarding rules and similarity is considered in terms of ability to provide insights regarding previous work on reasoning and categorization. For reasoning, the issue is the relation between this proposal and one-process as well as two-process accounts of deduction and induction. For categorization, the issue is how the proposal would simultaneously explain both similarity-to-rule and rule-to-similarity shifts.
Procedural replay: The anatomy and physics of the sleep spindle
Authors: Porte Helene Sophrin
Published: July 2005

This commentary implicates the neostriatum in the production of the EEG sleep spindle and in the processing of motor procedural learning in sleep. Whether the sleep spindle may implement not only the consolidation-based enhancement of procedural learning, but also its initial consolidation, is considered; as is the fit between (1) corticostriatal anatomy and physiology, and (2) the physical properties of the sleep spindle.
Memory consolidation during sleep: A form of brain restitution
Authors: Sheth Bhavin R.
Published: July 2005

Does sleep restore brain function or does it consolidate memory? I argue that memory consolidation during sleep is an offshoot of restitution. Continual learning causes local synapse-specific neural fatigue, which then masks expression of that learning, especially on time-limited tests of procedural skills. Sleep serves to restore the fatigued synapses, revealing the consolidation-based enhancement observed as a “latent” overnight improvement in learning.
Rule versus similarity: Different in processing mode, not in representations
Authors: Reber Rolf
Published: July 2005

Drawing on an example from artificial grammar learning, I present the case that similarity processes can be computationally identical to rules processes, but that participants in an artificial grammar learning experiment may use different processing modes to classify stimuli. The number of properties and other representational differences between rule and similarity processes are an accidental consequence of strategies used.
Consolidation enhancement: Which stages of sleep for which tasks?
Authors: Smith Carlyle T.
Published: July 2005

The Walker model raises a number of questions, particularly about the nature of the sleep states involved in consolidation enhancement. While REM sleep, Stage 2 sleep, and Stage 3/4 sleep have been implicated in procedural learning, we still do not understand which types of learning are involved with specific sleep states. Several possible ideas for future research are suggested.
The challenge of identifying cellular mechanisms of memory formation during sleep
Authors: Szymusiak Ronald
Published: July 2005

Cellular mechanisms hypothesized to underlie sleep-dependent memory consolidation are expressed throughout the brain during sleep. Use of sleep deprivation to evaluate the functional importance of these mechanisms is confounded by degradation in waking performance resulting from impaired vigilance. There is a need for methods that will permit disruption of specific mechanisms during sleep only in the neuronal circuits most critically involved in learning. This should be accomplished without global sleep disruption and with preservation of the restorative aspects of sleep.
Sleep and synaptic homeostasis
Authors: Tononi Giulio , Cirelli Chiara
Published: July 2005

We propose that sleep is linked to synaptic homeostasis. Specifically, we propose that: (1) Wakefulness is associated with synaptic potentiation in cortical circuits; (2) synaptic potentiation is tied to the homeostatic regulation of slow wave activity; (3) slow wave activity is associated with synaptic downscaling; and (4) synaptic downscaling is tied to several beneficial effects of sleep, including performance enhancement.
The inguinal macroglands of the frog Physalaemus nattereri (Leptodactylidae): structure, toxic secretion and relationship with deimatic behaviour
Authors: Lenzi‐Mattos R. , Antoniazzi M. M. , Haddad C. F. B. , Tambourgi D. V. , Rodrigues M. T. , Jared C.
Published: July 2005

Amphibian skin is characterized by the presence of mucous glands, related to cutaneous breathing, reproduction and water balance, and granular glands, related to the production of toxins used in defence. In some species the granular glands can form accumulations in certain regions of the body. This is the case for inguinal macroglands of the leptodactylid frog Physalaemus nattereri, where these structures form a pair of black discs associated with deimatic behaviour. The morphology of the inguinal macroglands and their secretion were studied in this species and correlated to deimatic behaviour. The inguinal macroglands are formed from elongated granular glands that, in contrast with the granular glands of the rest of the skin, have small spherical granules with a proteinic content. In the dermis of the whole body, except for the inguinal macroglands and the inguinal region, a well‐developed calcified dermal layer is observed. During deimatic behaviour these macroglands discourage a potential predator from attacking, but if visual cues are insufficient and the predator persists in the attack, a toxic secretion is eliminated in its mouth. This elimination is favoured by the absence of a calcified dermal layer in the macroglands, which makes the dermal region softer than the rest of the dorsal skin.
Presence of cumulus cells during in vitro fertilization protects the bovine oocyte against oxidative stress and improves first cleavage but does not affect further development
Authors: Fatehi A. Nader , Roelen Bernard A.J. , Colenbrander Ben , Schoevers Eric J. , Gadella Bart M. , Bevers Mart M. , van den Hurk Rob
Published: July 2005

The present study was conducted to evaluate the function of cumulus cells during bovine IVF. Oocytes within cumulus–oocyte complexes (COCs) or denuded oocytes (DOs) were inseminated in control medium, or DOs were inseminated in cumulus cell conditioned medium (CCCM). DOs exhibited reduced cleavage and blastocyst formation rates when compared with intact COCs. The reduced blastocyst formation rate of DOs resulted from reduced first cleavage but subsequent embryo development was not changed. Live-dead staining and staining for apoptotic cells revealed no differences in blastocysts from oocytes fertilized as COC or DO. Fertilization of DOs in CCCM partially restored the cleavage rate, suggesting that factors secreted by cumulus cells are important for fertilization but that physical contact between oocytes and cumulus cells is required for optimal fertilization and first cleavage. Exposure of COCs to hydrogen peroxide shortly before fertilization reduced the cleavage rate, but did not lead to enhanced death of cumulus cells or oocyte death. Exposure of DOs to hydrogen peroxide, however, resulted in oocyte death and a complete block of first cleavage, suggesting that cumulus cells protect the oocyte against oxidative stress during fertilization.
Transplantation of somatic nuclei into oocyte cytoplasm reveals that the chromosome properties determine the chromosome separation fate in rabbit
Authors: Zhang Li-sheng , Yao Li-Juan , Jiang Yan , Jiang Man-Xi , Lei Zi-Li , Sun Qing-Yuan , Chen Da-Yuan
Published: July 2005

G2/M somatic nuclei were introduced into enucleated meiotically competent oocytes and subsequently cultured in TCM199 plus 10% fetal calf serum (FCS). Pseudo-first polar bodies could be extruded, but the chromosomes failed to arrange normally. Kinetochores were traced with immunofluorescent microscopy using autoimmune sera from patients with CREST (Calcinosis, Raynaud's phenomenon, Esophageal dysmotility, Sclerodactyly, Telangiectasia) scleroderma. In vitro matured oocytes arrested at second meiotic metaphase and kinetochores were detectable as paired structures aligned at the spindle equator. At meiotic anaphase, present or past the kinetochores separated and remained aligned at the distal sides of the chromosomes until telophase, when their alignment perpendicular to the spindle axis was lost. Kinetochores failed to arrange normally after transferring somatic nuclei into oocytes. Our results suggest that somatic cell nuclei are unable to proceed normally through meiosis when introduced into oocyte meiotic cytoplasm.
A scientific and spiritual home
Authors: BREITBART WILLIAM
Published: July 2005

With the printing and distribution of this issue of Palliative
& Supportive Care (PS&C Volume 2, Number 4), we
complete and celebrate the second year of publication of this rather
unique scientific journal. It may seem to be a small affair really, this
scientific journal business, yet it is in fact larger than one initially
appreciates. It requires the immense diligence and hard work of a rather
large cadre of editors, publishers, reviewers, and of course the
scientists and writers who so graciously present their work into our
trust. But, what has been the most profound realization of the last year
is the fact that scientists and clinicians around the world actually read
and appreciate our “small” journal.
Commentary: Is there a model for demonstrating a beneficial financial
impact of initiating a palliative care program by an existing hospice
program?
Authors: PASSIK STEVEN D. , RUGGLES CAROL , BROWN GRETCHEN , SNAPP JANET , SWINFORD SUSAN , GUTGSELL TERRENCE , KIRSH KENNETH L.
Published: July 2005

The value of integrating palliative with curative modes of care
earlier in the course of disease for people with life threatening
illnesses is well recognized. Whereas the now outdated model of waiting
for people to be actively dying before initiating palliative care has been
clearly discredited on clinical grounds, how a better integration of modes
of care can be achieved, financed and sustained is an ongoing challenge
for the health care system in general as well as for specific
institutions. When the initiative comes from a hospital or academic
medical center, which may, for example, begin a palliative care
consultation service, financial benefits have been well documented. These
palliative care services survive mainly by tracking cost savings that can
be realized in a number of ways around a medical center. We tried to pilot
3 simple models of potential cost savings afforded to hospice by
initiating a palliative care program. We found that simple models cannot
capture this benefit (if it in fact exists). By adding palliative care,
hospice, while no doubt improving and streamlining care, is also taking on
more complex patients (higher drug costs, shorter length of stay, more
outpatient, emergency room and physician visits). Indeed, the hospice was
absorbing the losses associated with having the palliative care program.
We suggest that an avenue for future exploration is whether partnering
between hospitals and hospice programs can defray some of the costs
incurred by the palliative care program (that might otherwise be passed on
to hospice) in anticipation of cost savings. We end with a series of
questions: Are there financial benefits? Can they be modeled and
quantified? Is this a dilemma for hospice programs wanting to improve the
quality of care but who are not able on their own to finance it?
Das Klinisch Psychologische Diagnosesystem 38 (KPD-38)
Authors: Percevic Robert , Gallas Christine , Wolf Markus , Haug Severin , Hünerfauth Thomas , Schwarz Michael , Kordy Hans
Published: July 2005

Zusammenfassung. Mit dem KPD-38 steht ein neues Instrument für die Qualitätssicherung und das Ergebnismonitoring in der Psychotherapie und psychosomatischen Medizin zur Verfügung. Im vorliegenden Beitrag werden die Entwicklung des KPD-38 und erste Erfahrungen aus dem Einsatz in der Qualitätssicherung beschrieben. Das Instrument wurde einer Bevölkerungsstichprobe (N = 2066) sowie einem Patientenkollektiv aus der stationären Psychotherapie (N = 351) vorgelegt. Es wurden Prüfungen der Validität, Reliabilität, der computergestützten Vorgabe, Sensitivität und Spezifität durchgeführt. Neben testökonomischen Gesichtspunkten sprechen insbesondere die deutlichen Belege der Validität des KPD-38 für den Einsatz in diesem speziellen Anwendungsbereich. Die vielversprechenden Hinweise auf seinen Nutzen für die Behandlungs- und Versorgungsplanung durch therapiebegleitende Rückmeldungen lassen weitere Detailstudien als lohnend erscheinen.
Equatorial Pacific subsurface countercurrents in a high‐resolution global ocean circulation model
Authors: Ishida Akio , Mitsudera Humio , Kashino Yuji , Kadokura Teruaki
Published: July 2005

We analyzed the results of a high‐resolution global ocean circulation model with 1/4‐degree grid spacing and 55 vertical levels to investigate the structure and the mechanism of subsurface countercurrents (SCCs) in the equatorial Pacific Ocean. The model SCCs have observably similar structures; that is, they are associated with the pycnostad between 26.0 and 26.8σθ, deep in the west and shallow and in the east, and the densities in the SCCs' cores decrease from west to east. The volume transport in the density layer shows that each of the north SCC and the primary south SCC accompanies a westward current at their equator side; the SCC and the westward current comprise the recirculation gyre there. High mesoscale eddy activity results in a mean flow acceleration corresponding to the SCCs, especially to the north SCC in the eastern Pacific Ocean. The structures are consistent with the low potential vorticity (PV) in the equatorial region; thus the recirculations are suggested to be related with the homogenization of the PV in the equatorial region by eddy activity. In contrast, the secondary south SCC flows southeastward along the thickness front of the layer between 26.0 and 26.8σθ and ends near the coast around 11°S, 80°W. The coastal undercurrent and upwelling drain the water from it there. This suggests that the secondary south SCC is not a part of recirculation, but rather driven by force near the eastern boundary.
Hybrid approach for ab initio molecular dynamics simulation combining energy density analysis and short-time Fourier transform: Energy transfer spectrogram
Authors: Yamauchi Yusuke , Nakai Hiromi
Published: July 2005

We propose a new analysis technique for specifying molecular vibrational modes related with intramolecular and/or intermolecular energy transfer in ab initio molecular dynamics simulation of chemical reaction. The technique combines the short-time Fourier transform method with energy density analysis, which partitions the quantum chemical potential energy in the system into atomic contributions. The image obtained by the combined scheme, termed an energy transfer spectrogram (ETS), enables us to understand the dynamics of energy transfer by time-frequency representation. The time change of the local energy is quite important in chemical reactions. In order to assess the performance of the ETS, its application to the collision reaction between two carbon dioxide molecules is shown.
Effect of Ti on the optical properties of Ag nanocrystals in silica
Authors: Magruder R. H. , Meldrum Al
Published: July 2005

Type III silica samples were implanted sequentially with Ti and Ag ions. The implantation of Ti results in the modification of the silica forming a Ti silicate phase. Subsequent implantation of Ag into this layer results in the formation of Ag metal nanocrystals with modified optical properties compared to samples without the Ti ions. The presence of the Ti results in significantly smaller particle size compared to samples implanted with Ag alone. The incorporation of the Ti causes a shift in the wavelength of the surface-plasmon resonance of the Ag nanocrystals and a change in the magnitude of the surface-plasmon resonance absorption.
Molecular and solid-state (8-hydroxy-quinoline)aluminum interaction with magnesium: A first-principles study
Authors: Meloni S. , Palma A. , Kahn A. , Schwartz J. , Car R.
Published: July 2005

The interaction between Mg and (8-hydroxyquinoline)aluminum, Alq3, is investigated via ab initio molecular dynamics based on density-functional theory. We model the Alq3 thin film both with a single Alq3 molecule in vacuo (as is usually done in the literature) and with an Alq3 crystalline structure. Comparing the results from these two models, we show that bulk calculations provide a better description of the chemical processes involved, allowing the Mg atom to react with two neighboring Alq3 molecules, as was alluded to in a previous publication [S. Meloni, A. Palma, A. Kahn, J. Schwartz, and R. Car, J. Am. Chem. Soc. 125, 7808 (2003)]. Moreover, core-level shift calculations are in good agreement with experimental measurements only when using the solid phase approach. We also propose a different interpretation of the Al(2p) experimental core level presented in a previous work [C. Shen, A. Kahn, and J. Schwartz, J. Appl. Phys. 89, 449 (2001)].
Constrained Rouse model of rubber viscoelasticity
Authors: Vandoolaeghe W. L. , Terentjev E. M.
Published: July 2005

In this work we use a new approach to investigate the equilibrium and linear dynamic-mechanical response of a polymer network. The classical Rouse model is extended to incorporate quenched constraints on its end-boundary conditions; a microscopic stress tensor for the network system is then derived in the affine deformation limit. To test the model we calculate the macroscopic stress in equilibrium, corresponding to the long-time limit of relaxation. Particular attention is paid to the treatment of compressibility and hydrostatic pressure in a sample with open boundaries. Although quite different in general, for small strains the model compares well with the classic equilibrium rubber-elasticity models. The dynamic shear modulus is obtained for a network relaxing after an instantaneous step strain by keeping track of relaxation of consecutive Rouse modes of constrained network strands. The results naturally cover the whole time range—from the dynamic glassy state down to the equilibrium incompressible rubber plateau.
Generalized Langevin theory on the dynamics of simple fluids under external fields
Authors: Yamaguchi T. , Matsuoka T. , Koda S.
Published: July 2005

A theory on the time development of the density and current fields of simple fluids under an external field is formulated through the generalized Langevin formalism. The theory is applied to the linear solvation dynamics of a fixed solute regarding the solute as the external field on the solvent. The solute-solvent-solvent three-body correlation function is taken into account through the hypernetted-chain integral equation theory, and the time correlation function of the random force is approximated by that in the absence of the solute. The theoretical results are compared with those of molecular-dynamics (MD) simulation and the surrogate theory. As for the transient response of the density field, our theory is shown to be free from the artifact of the surrogate theory that the solvent can penetrate into the repulsive core of the solute during the relaxation. We have also found a large quantitative improvement of the solvation correlation function compared with the surrogate theory. In particular, the short-time part of the solvation correlation function is in almost perfect agreement with that from the MD simulation, reflecting that the short-time expansion of the theoretical solvation correlation function is exact up to t2 with the exact three-body correlation function. A quantitative improvement is found in the long-time region, too. Our theory is also applied to the force-force time correlation function of a fixed solute, and similar improvement is obtained, which suggests that our present theory can be a basis to improve the mode-coupling theory on the solute diffusion.
Temperature-dependent fatigue behaviors of ferroelectric Pb(Zr0.52Ti0.48)O3 and Pb0.75La0.25TiO3 thin films
Authors: Liu J.-M. , Wang Y. , Zhu C. , Yuan G. L. , Zhang S. T.
Published: July 2005

The polarization switching fatigue of ABO3-perovskite ferroelectric thin-film Pb(Zr0.52Ti0.48)O3 (PZT) prepared by metalorganic decomposition (MOD) and Pb0.75La0.25TiO3 (PLT) prepared by pulsed laser deposition (PLD), are investigated. The temperature as a degree of freedom is employed to modulate the switching fatigue and unveil the roles of oxygen vacancies associated with polarization switching. It is confirmed that the polarization fatigue is dominated by the long-range diffusion of oxygen vacancies, leading to a superior fatigue resistance at low temperature. More importantly, it is revealed that although PLD-prepared PLT films have a higher density of oxygen vacancies than MOD-prepared PZT films, the evaluated barrier for oxygen diffusion in PLD-prepared PLT films is ∼1.3eV, larger than ∼1.0eV, the barrier in MOD-prepared PZT films, responsible for a weaker fatigue behavior in PLD-prepared PLT films.