bluuebunny/crossref_metadata_2025 huggingface dataset:
Population characteristics of the estuarine isopod Gnorimosphaeroma insulare in three contrasting habitats: sedge marsh, algal bed, and wood debris
Authors: Stanhope M. J. , Powell D. W. , Hartwick E. B.
Published: August 2008

Population characteristics of Gnorimosphaeroma insulare (Isopoda: Sphaeromatidae) were investigated in three habitats within the Squamish estuary, British Columbia: a log debris area, an embankment along the perimeter of a Carex lyngbyei marsh, and a Fucus distichus community. Gnorimosphaeroma insulare annual production was highest in the Fucus habitat (39.54–48.05 g dry wt∙m−2∙year−1) followed by "bank" (22.97–27.74 g∙m−2∙year−1) and then wood debris habitats (4.72–6.43 g∙m−2∙year−1). Cohort figures indicated that male productivity was greater than female productivity in all locations. Production:biomass ratios were similar in all three habitats and ranged between 2.47 and 3.17. Mortality rates were greatest in Fucus; those in wood debris and bank habitats were similar. Growth rates were highest in the bank habitat; those in wood debris and Fucus were similar. Growth and mortality rates of males were greater than those of females. Gnorimosphaeroma insulare is an annual semelparous species. Males died soon after mating, females soon after brood release. Fecundity was linearly related to body size but differed between locations (females from wood debris produced more eggs). Brood mortality was dependent on habitat: females from the bank habitat possessed the highest brood mortality followed by those from wood debris; females from Fucus did not possess any significant brood mortality. Egg development time was estimated at 120 days. The reduced carrying capacity of wood debris substrate is thought to be due to a paucity of microbial epiphytes, particularly fungi.
Responses of serum calcium and phosphorus in the frog Rana tigrina to injection of various vitamin D analogs
Authors: Srivastav Ajai K. , Rani L. , Swarup K.
Published: August 2008

Intraperitoneal injections of either vitamin D3 (4 IU/100 g body wt.), 25 hydroxyvitamin D3 (100 ng/100 g body wt.), or 1,25 dihydroxyvitamin D3 (100 ng/100 g body wt.) for 15 days induced hypercalcemia, hyperphosphatemia, and depletion of calcium deposits in the paravertebral lime sacs in an anuran, Rana tigrina.
Feeding association between seabirds and killer whales, Orcinus orca, around subantarctic Crozet Islands
Authors: Ridoux Vincent
Published: August 2008

Twenty-nine observations of killer whale (Orcinus orca) pods and associated bird flocks were made from March 1982 to February 1983 from the coast of Possession Island (Crozet Archipelago). Coastal foraging birds, such as giant petrels (Macronectes sp.), Cape pigeon (Daption capense), and kelp gull (Larus dominicanus), are more often associated with feeding pods than with nonfeeding ones, while pelagic species like the white-chinned petrel (Procellaria aequinoctialis) may deliberately follow the whales and wait for floating offal. The black-browed albatross (Diomedea melanophrys), which is somewhat intermediate between coastal and pelagic birds, shows components of both strategies.
DESCRIPTIONAL COMPLEXITY OF SPLICING SYSTEMS
Authors: LOOS REMCO , MALCHER ANDREAS , WOTSCHKE DETLEF
Published: August 2008

In this paper, the descriptional complexity of extended finite splicing systems is studied. These systems are known to generate exactly the class of regular languages. Upper and lower bounds are shown relating the size of these splicing systems, defined as the total length of the rules and the initial language of the system, to the size of their equivalent minimal nondeterministic finite automata (NFA). In addition, an accepting model of extended finite splicing systems is studied. Using this variant one can obtain systems which are more than polynomially more succinct than the equivalent NFA or generating extended finite splicing system.
TESTING THE DESCRIPTIONAL POWER OF SMALL TURING MACHINES ON NONREGULAR LANGUAGE ACCEPTANCE
Authors: MEREGHETTI CARLO
Published: August 2008

We study lower bounds on space and input head reversals for deterministic, nondeterministic, and alternating Turing machines accepting nonregular languages. Three notions of space, namely strong, middle, weak are considered, and another notion, called accept, is introduced. In all cases, we obtain tight lower bounds. Moreover, we show that, while for determinism and nondeterminism such lower bounds are optimal even with respect to unary languages, for alternation optimal lower bounds for unary languages turn out to be strictly higher than those for languages over alphabets with two or more symbols.
REPRESENTATIONS AND CHARACTERIZATIONS OF LANGUAGES IN CHOMSKY HIERARCHY BY MEANS OF INSERTION-DELETION SYSTEMS
Authors: PĂUN GHEORGHE , PÉREZ-JIMÉNEZ MARIO J. , YOKOMORI TAKASHI
Published: August 2008

Insertion-deletion operations are much investigated in linguistics and in DNA computing and several characterizations of Turing computability and characterizations or representations of languages in Chomsky hierarchy were obtained in this framework.

In this note we contribute to this research direction with a new characterization of this type, as well as with representations of regular and context-free languages, mainly starting from context-free insertion systems of as small as possible complexity. For instance, each recursively enumerable language L can be represented in a way similar to the celebrated Chomsky-Schützenberger representation of context-free languages, i.e., in the form L = h(L(γ) ∩ D), where γ is an insertion system of weight (3, 0) (at most three symbols are inserted in a context of length zero), h is a projection, and D is a Dyck language. A similar representation can be obtained for regular languages, involving insertion systems of weight (2,0) and star languages, as well as for context-free languages – this time using insertion systems of weight (3, 0) and star languages.
REMARKS ON CONTEXT-FREE PARALLEL COMMUNICATING GRAMMAR SYSTEMS GENERATING CROSSED AGREEMENTS
Authors: TRUTHE BIANCA
Published: August 2008

Parallel communicating grammar systems are language generating devices consisting of several grammars which derive synchronously their sentential forms and communicate with each other by sending their sentential forms to another component on request. Due to collaboration, grammar systems with context-free components are more powerful than a single context-free grammar; they even can generate all recursively enumerable languages.

In natural languages, there occur constructions that cannot be modelled by context-free languages. Three important phenomena are the so-called multiple agreements, crossed agreements and replication which are represented by the three non-context-free languages K1 = { anbncn | n ≥ 1 }, K2 = { anbmcndm | m ≥ 1, n ≥ 1 }, and K3 = { ww | w ∈ { a, b }+}, respectively.

In the present paper, we give parallel communicating grammar systems (PC grammar systems) that are context-free and that generate the language K2, working in different modes. In two cases, the results are optimal.
ON COUNTER MACHINES, REACHABILITY PROBLEMS, AND DIOPHANTINE EQUATIONS
Authors: IBARRA OSCAR H. , DANG ZHE , YANG LINMIN
Published: August 2008

We give a brief survey of results that use “reversal-bounded counters” in studying reachability problems for various classes of transition systems. We also discuss the connection between the decidability of reachability in counter machines and the solvability of certain Diophantine equations.
REACHABILITY PROBLEMS IN LOW-DIMENSIONAL ITERATIVE MAPS
Authors: KURGANSKYY OLEKSIY , POTAPOV IGOR , SANCHO-CAPARRINI FERNANDO
Published: August 2008

In this paper we analyze the dynamics of one-dimensional piecewise maps. We show that one-dimensional piecewise affine maps are equivalent to pseudo-billiard or so called “strange billiard” systems. We also show that use of more general classes of functions lead to undecidability of reachability problem for one-dimensional piecewise maps.
REACHABILITY ANALYSIS IN VERIFICATION VIA SUPERCOMPILATION
Authors: LISITSA ALEXEI , NEMYTYKH ANDREI P.
Published: August 2008

We present an approach to verification of parameterized systems, which is based on program transformation technique known as supercompilation. In this approach the statements about safety properties of a system to be verified are translated into the statements about properties of the program that simulates and tests the system. Supercompilation is used then to establish the required properties of the program. In this paper we show that reachability analysis performed by supercompilation can be seen as the proof of a correctness condition by induction. We formulate suitable induction principles and proof strategies and illustrate their use by examples of verification of parameterized protocols.
A MINIMUM-PROCESS COORDINATED CHECKPOINTING PROTOCOL FOR MOBILE COMPUTING SYSTEMS
Authors: GUPTA SUNIL KUMAR , CHAUHAN R. K. , KUMAR PARVEEN
Published: August 2008

Checkpoint is a designated place in a program at which normal process is interrupted specifically to preserve the status information necessary to allow resumption of processing at a later time. A checkpoint algorithm for mobile distributed systems needs to handle many new issues like: mobility, low bandwidth of wireless channels, lack of stable storage on mobile nodes, disconnections, limited battery power and high failure rate of mobile nodes. These issues make traditional checkpointing techniques unsuitable for such environments. Minimum-process coordinated checkpointing is an attractive approach to introduce fault tolerance in mobile distributed systems transparently. This approach is domino-free, requires at most two checkpoints of a process on stable storage, and forces only a minimum number of processes to checkpoint. But, it requires extra synchronization messages, blocking of the underlying computation or taking some useless checkpoints. In this paper, we design a minimum-process checkpointing algorithm for mobile distributed systems, where no useless checkpoint is taken. We reduce the blocking of processes by allowing the processes to do their normal computations, send messages and receive selective messages during their blocking period.
STOCHASTIC DYNAMICS OF VISCOELASTIC SKEINS: CONDENSATION WAVES AND CONTINUUM LIMITS
Authors: ALBEVERIO SERGIO , ALT WOLFGANG
Published: August 2008

Skeins (one-dimensional queues) of migrating birds show typical fluctuations in swarm length and frequent events of "condensation waves" starting at the leading bird and traveling backward within the moving skein, similar to queuing traffic waves in car files but more smooth.

These dynamical phenomena can be fairly reproduced by stochastic ordinary differential equations for a "multi-particle" system including the individual tendency of birds to attain a preferred speed as well as mutual interaction "forces" between neighbors, induced by distance-dependent attraction or repulsion as well as adjustment of velocities. Such a one-dimensional system constitutes a so-called "stochastic viscoelastic skein."

For the simple case of nearest neighbor interactions we define the density between individualsu = u(t, x) as a step function inversely proportional to the neighbor distance, and the velocity function v = v(t, x) as a standard piecewise linear interpolation between individual velocities. Then, in the limit of infinitely many birds in a skein of finite length, with mean neighbor distance δ converging to zero and after a suitable scaling, we obtain continuum mass and force balance equations that constitute generalized nonlinear compressible Navier–Stokes equations. The resulting density-dependent stress functions and viscosity coefficients are directly derived from the parameter functions in the original model.

We investigate two different sources of additive noise in the force balance equations: (1) independent stochastic accelerations of each bird and (2) exogenous stochastic noise arising from pressure perturbations in the interspace between them. Proper scaling of these noise terms leads, under suitable modeling assumptions, to their maintenance in the continuum limit δ → 0, where they appear as (1) uncorrelated spatiotemporal Gaussian noise or, respectively, (2) certain spatially correlated stochastic integrals. In both cases some a priori estimates are given which support convergence to the resulting stochastic Navier–Stokes system.

Natural conditions at the moving swarm boundaries (along characteristics of the hyperbolic system) appear as singularly perturbed zero-tension Neumann conditions for the velocity function v. Numerical solutions of this free boundary value problem are compared to multi-particle simulations of the original discrete system. By analyzing its linearization around the constant swarm state, we can characterize several properties of swarm dynamics. In particular, we compute approximating values for the averaged speed and length of typical condensation waves.
CONTINUUM LIMIT OF SELF-DRIVEN PARTICLES WITH ORIENTATION INTERACTION
Authors: DEGOND PIERRE , MOTSCH SÉBASTIEN
Published: August 2008

The discrete Couzin–Vicsek algorithm (CVA), which describes the interactions of individuals among animal societies such as fish schools is considered. In this paper, a kinetic (mean-field) version of the CVA model is proposed and its formal macroscopic limit is provided. The final macroscopic model involves a conservation equation for the density of the individuals and a non-conservative equation for the director of the mean velocity and is proved to be hyperbolic. The derivation is based on the introduction of a non-conventional concept of a collisional invariant of a collision operator.
FIRST-ORDER MACROSCOPIC MODELLING OF HUMAN CROWD DYNAMICS
Authors: COSCIA V. , CANAVESIO C.
Published: August 2008

This paper deals with the mathematical modelling of crowd dynamics within the framework of continuum mechanics. The method uses the mass conservation equation closed by phenomenological models linking the local velocity to density and density gradients. The closures take into account movement in more than one space dimension, presence of obstacles, pedestrian strategies, and modelling of panic conditions. Numerical simulations of the initial-boundary value problems visualize the ability of the models to predict several interesting phenomena related to the complex system under consideration.
A TRAFFIC-FLOW MODEL WITH CONSTRAINTS FOR THE MODELING OF TRAFFIC JAMS
Authors: BERTHELIN FLORENT , DEGOND PIERRE , LE BLANC VALERIE , MOUTARI SALISSOU , RASCLE MICHEL , ROYER JULIEN
Published: August 2008

Recently, Berthelin et al.,4 introduced a traffic-flow model describing the formation and the dynamics of traffic jams. This model which consists of a Constrained Pressureless Gas Dynamics system assumes that the maximal density constraint is independent of the velocity. However, in practice, the distribution of vehicles on a highway depends on their velocity. In this paper, a more realistic model namely the Second Order Model with Constraints (in short SOMC) is proposed, derived from the Aw and Rascle model,1 which takes into account this feature. Moreover, when the maximal density constraint is saturated, the SOMC model "relaxes" to the Lighthill and Whitham model.20 An existence result of weak solutions for this model by means of cluster dynamics is proved in order to construct a sequence of approximations, and the associated Riemann problem is solved completely.
VERTEX FLOW MODELS FOR VEHICULAR TRAFFIC ON NETWORKS
Authors: D'APICE CIRO , PICCOLI BENEDETTO
Published: August 2008

Some models of flow on a network are discussed. Assuming a macroscopic approach on each arc of the network, we consider a system of conservation laws and various possible choices to describe the evolution at vertices are discussed. A general framework proposed in recent literature is presented, then some new solutions for the scalar case are proposed and analyzed.
ON THE MODELLING CROWD DYNAMICS FROM SCALING TO HYPERBOLIC MACROSCOPIC MODELS
Authors: BELLOMO NICOLA , DOGBÉ CHRISTIAN
Published: August 2008

This paper, that deals with the modelling of crowd dynamics, is the first one of a project finalized to develop a mathematical theory refereing to the modelling of the complex systems constituted by several interacting individuals in bounded and unbounded domains. The first part of the paper is devoted to scaling and related representation problems, then the macroscopic scale is selected and a variety of models are proposed according to different approximations of the pedestrian strategies and interactions. The second part of the paper deals with a qualitative analysis of the models with the aim of analyzing their properties. Finally, a critical analysis is proposed in view of further development of the modelling approach. Additional reasonings are devoted to understanding the conceptual differences between crowd and swarm modelling.
Leucine stimulates protein synthesis in skeletal muscle of neonatal pigs by enhancing mTORC1 activation
Authors: Suryawan Agus , Jeyapalan Asumthia S. , Orellana Renan A. , Wilson Fiona A. , Nguyen Hanh V. , Davis Teresa A.
Published: August 2008

Skeletal muscle in the neonate grows at a rapid rate due in part to an enhanced sensitivity to the postprandial rise in amino acids, particularly leucine. To elucidate the molecular mechanism by which leucine stimulates protein synthesis in neonatal muscle, overnight-fasted 7-day-old piglets were treated with rapamycin [an inhibitor of mammalian target of rapamycin (mTOR) complex (mTORC)1] for 1 h and then infused with leucine for 1 h. Fractional rates of protein synthesis and activation of signaling components that lead to mRNA translation were determined in skeletal muscle. Rapamycin completely blocked leucine-induced muscle protein synthesis. Rapamycin markedly reduced raptor-mTOR association, an indicator of mTORC1 activation. Rapamycin blocked the leucine-induced phosphorylation of mTOR, S6 kinase 1 (S6K1), and eukaryotic initiation factor (eIF)4E-binding protein-1 (4E-BP1) and formation of the eIF4E·eIF4G complex and increased eIF4E·4E-BP1 complex abundance. Rapamycin had no effect on the association of mTOR with rictor, a crucial component for mTORC2 activation, or G protein β-subunit-like protein (GβL), a component of mTORC1 and mTORC2. Neither leucine nor rapamycin affected the phosphorylation of AMP-activated protein kinase (AMPK), PKB, or tuberous sclerosis complex (TSC)2, signaling components that reside upstream of mTOR. Eukaryotic elongation factor (eEF)2 phosphorylation was not affected by leucine or rapamycin, although current dogma indicates that eEF2 phosphorylation is mTOR dependent. Together, these in vivo data suggest that leucine stimulates muscle protein synthesis in neonates by enhancing mTORC1 activation and its downstream effectors.
MNAR functionally interacts with both NH2- and COOH-terminal GR domains to modulate transactivation
Authors: Kayahara Midori , Ohanian Jacqueline , Ohanian Vasken , Berry Andrew , Vadlamudi Ratna , Ray David W.
Published: August 2008

Glucocorticoids are potent anti-inflammatory agents, acting through the glucocorticoid receptor (GR) to regulate target gene transcription. However, GR may also exert acute effects, including activation of signaling kinases such as c-Src and protein kinase B, possibly via the scaffold protein, modulator of nongenomic action of the estrogen receptor (MNAR). MNAR inhibited GR transactivation in A549 cells, but in HEK293 cells there was a ligand concentration-dependent biphasic effect. Transactivation driven by low ligand concentrations was inhibited by MNAR expression, whereas higher ligand concentrations were potentiating. Further analysis revealed that MNAR inhibited transactivation by the ligand-independent activation function (AF)1 but potentiated the COOH-terminal AF2 domain. The effect of MNAR was independent of c-Src activity, demonstrated by inhibitors and c-Src knockdown studies. In support of the role of MNAR in modulating GR transactivation, coimmunoprecipitation studies showed interaction between MNAR and GR in the nucleus but not the cytoplasm. Furthermore, MNAR and c-Src were also found to physically interact in the nucleus. Immunofluorescence studies showed MNAR to be predominantly a nuclear protein, with significant colocalization with GR. Deletion studies revealed that MNAR 884-1130 was coimmunoprecipitated with GR, and furthermore this fragment inhibited GR transactivation function when overexpressed. In addition, MNAR 1-400, which contains multiple LxxLL motifs, also inhibited GR transactivation. Taken together, MNAR interacts with GR in the nucleus but not cytoplasm and regulates GR transactivation in a complex manner depending on cell type. MNAR is capable of regulating both AF1 and AF2 functions of the GR independently. MNAR expression is likely to mediate important cell variation in glucocorticoid responsiveness, in a c-Src-independent mechanism.
Left Ventricular Response to Continuous Positive Airway Pressure: Role of Left Ventricular Geometry
Authors: Steiner Stephan , Schannwell Christiana M. , Strauer Bodo E.
Published: August 2008

Background: Continuous positive airway pressure (CPAP) may be a useful adjunct in patients with congestive heart failure. Objectives: To evaluate the relationship between left ventricular geometry and hemodynamic response to CPAP. Methods: Right heart catheter studies were performed in 26 patients before, during and after application of CPAP (8 cm H2O) over 15 min. Response to therapy was defined as an increase in stroke volume using CPAP. Results: Cardiac output decreased from 6.9 ± 1.9 to 6.2 ± 1.4 liters/min (p = 0.01) with a slight increase after cessation of CPAP (not significant). There was no significant change in stroke volume (92 ± 34 vs. 90 ± 31 ml, p = 0.584) or pulmonary capillary wedge pressure (14.7 ± 7.0 vs. 14.2 ± 6.5 mm Hg, p = 0.26). There was a correlation between hemodynamic effects of CPAP therapy and left ventricular end-diastolic volume (r = 0.515, p = 0.01), mass-volume ratio (r = –0.41, p = 0.04) and pulmonary capillary wedge pressure (r = 0.654, p = 0.001) at baseline. Half the patients (n = 13) were categorized as responders with an average increase in stroke volume of 11.5 ± 2.1%. Responders showed significantly higher left ventricular end-diastolic volume, pulmonary capillary wedge pressure and lower mass-volume ratio. Conclusion: Patients with high pulmonary capillary wedge pressure, elevated end-diastolic volumes and a low left ventricular mass-volume ratio might profit from CPAP therapy.
A 62-Year-Old Woman with Bilateral Pleural Effusions and Pulmonary Infiltrates Caused by Extramedullary Hematopoiesis
Authors: Schwarz C. , Bittner R. , Kirsch A. , Loddenkemper C. , Mairinger T. , Schönfeld N. , Serke M. , Loddenkemper R.
Published: August 2008

A 62-year-old female presented with a 1-month history of irritating cough and increasing dyspnea. A chronic idiopathic myelofibrosis had been diagnosed 5 years ago. CT of the chest and abdomen showed bilateral pleural effusions with a thickened pleura, nodular infiltrations in both lungs, enlarged intraabdominal lymph nodes and splenomegaly. Pleuroscopy (medical thoracoscopy) on the left side revealed dense tumorous nodules mainly on the posterior chest wall pleura, but also on the diaphragm and the lung. Biopsies taken from the chest wall pleura revealed extramedullary hematopoiesis (EMH) with abnormal megakaryocytes as well as myeloid and erythroid precursors. After unsuccessful tetracycline pleurodesis, talcum slurry was instilled via the chest tube without recurrence of the pleural effusion. Furthermore, treatment with hydroxyurea was started, and the disease regressed and then remained stable over the next 24 months. In conclusion, the pleuropulmonary findings were caused by EMH due to chronic idiopathic myelofibrosis. The definite diagnosis was established by pleuroscopy followed by successful pleurodesis with talc slurry, after tetracycline pleurodesis had failed.
Acetate Metabolism in Escherichia coli Strains Lacking Phosphoenolpyruvate: Carbohydrate Phosphotransferase System; Evidence of Carbon Recycling Strategies and Futile Cycles
Authors: Sigala Juan Carlos , Flores Salvador , Flores Noemí , Aguilar César , de Anda Ramón , Gosset Guillermo , Bolívar Francisco
Published: August 2008

The ptsHIcrr operon was deleted from Escherichia coli wild-type JM101 to generate strain PB11 (PTS–). In a mutant derived from PB11 that partially recovered its growth capacity on glucose by an adaptive evolution process (PB12, PTS–Glc+), part of the phosphoenolpyruvate not used in glucose transport has been utilized for the synthesis of aromatic compounds. In this report, it is shown that on acetate as a carbon source, PB11 displayed a specific growth rate (μ) higher than PB12 (0.21 and 0.13 h–1, respectively) while JM101 had a μ of 0.28 h–1. To understand these growth differences on acetate, we compared the expression profiles of central metabolic genes by RT-PCR analysis. Obtained data revealed that some gluconeogenic genes were downregulated in both PTS– strains as compared to JM101, while most glycolytic genes were upregulated in PB12 in contrast to PB11 and JM101. Furthermore, inactivation of gluconeogenic genes, like ppsA, sfcA, and maeB,and poxB gene that codes for pyruvate oxidase, has differential impacts in the acetate metabolism of these strains. Results indicate that growth differences on acetate in the PTS– derivatives are due to potential carbon recycling strategies, mainly in PB11, and futile carbon cycles, especially in PB12.
Evolution of Family 18 Glycoside Hydrolases: Diversity, Domain Structures and Phylogenetic Relationships
Authors: Karlsson Magnus , Stenlid Jan
Published: August 2008

Chitin and its derivates have many industrial and medical uses. There is a demand for chitin-modifying enzymes with new or modified properties and as microorganisms are the primary degraders of chitin in the environment, they provide a source of chitin-modifying enzymes with novel properties. We have analyzed the diversity, domain structure and phylogenetic relationships between family 18 chitinases based on complete genome sequences of bacteria, archaea, viruses, fungi, plants and animals. Our study shows that family 18 chitinases are divided into three main clusters, A, B and C. Clusters A and B both contain family 18 chitinases from bacteria, fungi and plants, suggesting that the differentiation of cluster A and B chitinases preceded the appearance of the eukaryotic lineage. Subgroups within clusters can have specific domain structures, as well as specific amino acid replacements in catalytic sites, which imply functional adaptation. This work provides a comprehensive overview of the evolutionary relationships of family 18 chitinases and provides a context for further investigations on functional aspects of family 18 chitinases in ecology and biotechnology.
Predictors of Improvement or Decline in Instrumental Activities of Daily Living among Community-Dwelling Older Japanese
Authors: Fujiwara Yoshinori , Yoshida Hiroto , Amano Hidenori , Fukaya Taro , Liang Jersey , Uchida Hayato , Shinkai Shoji
Published: August 2008

Background: To explore predictors of functional improvement or decline in instrumental activities of daily living (IADL) among community-dwelling older people. Methods: Of all the residents (≧65 years, n = 1,673) living in Yoita town, Niigata prefecture, Japan, in 2000, 1,544 subjects who participated in the baseline interview survey (T1) were followed up until 2002 (T2). A wide range of variables obtained in T1 was entered into the model predicting functional improvement or decline in IADL. Results: Among 1,274 individuals who participated in both T1 and T2, 105 subjects showed improvement, 194 decline, and the remaining 975 showed stability in IADL. Multiple logistic regression analyses indicated that good self-rated health and cognitive function (MMSE ≧24) at T1 were good predictors of both improvement and protection against decline in IADL. Independence in basic activities of daily living predicted improvement in IADL. Advanced age and poor walking ability predicted decline in IADL. Conclusions: Good self-rated health and cognitive function predicted both improvement and protection against decline in IADL. Thus, intervention programs aiming at maintaining both good self-rated health and cognitive function should be able to improve IADL.
The Modification of the Electrical Property in Double-Walled Carbon Nanotube Devices with a Self-Assembled Monolayer of Molecules
Authors: Jeon Eun-Kyoung , Kim Hyo-Suk , Kim Byoung-Kye , Kim Ju-Jin , Lee Jeong-O , Lee Cheol Jin
Published: August 2008

We have investigated the electrical transports of double-walled carbon nanotube field effect transistors (DWNT-FETs) with modified contacts. The CNT/Au metal contacts of DWNT-FETs were modified with a self-assembled monolayer of 2-aminoethanethiol molecules. In ambient air, the contact-modified
DWNT-FETs showed a decreased conductance in the p-channel (negative gate voltages) and an increased conductance in the n-channel (positive gate voltages), while the original device showed p-type transport. In a vacuum, the n-channel current in the contact-modified
DWNT-FET started to rise. We observed a clear n-type transport in the high vacuum. Almost no changes in the gate threshold voltages were observed by means of the contact-modification with a self-assembled monolayer. While the semiconducting DWNT-FET showed a clear transition from a
p-type to n-type transistor with contact modification, no apparent changes were observed in semi-metallic DWNT devices.
Seed-Mediated Growth of ZnO Nanorods on Multiwalled Carbon Nanotubes
Authors: Li Changqing , Jin Zhong , Chu Haibin , Li Yan
Published: August 2008

The heterostructures of ZnO nanorods on multiwalled carbon nanotubes (MWNTs) were fabricated by a seed-mediated growth method. First, the surfaces of the carbon nanotubes (CNTs) were coated in situ with mono-dispersed ZnO nanocrystals of about 7 nm by the reaction of zinc acetate
and sodium hydroxide. These nanocrystals were then served as the seeds for further growth of ZnO nanorods. In the second step, ZnO nanorods were grown on MWNTs coated with ZnO nanocrystals in an aqueous solution of zinc nitrate and equimolar hexamethylenetetramine at 85 °C. Typically,
the ZnO nanorods had the length of 300–600 nm and the diameter of 40–140 nm and took a random direction on the outside walls of MWNTs. The morphology of the ZnO nanorods was dependent on pH, reactant concentration, and growing time.
Investigation of Luminescent Poly(propylene imine) Dendrimer
Authors: Tamano Kana , Imae Toyoko
Published: August 2008

Luminescence phenomenon from NH2-terminated third generation poly(propylene imine) dendrimers in water was investigated. Two excitation bands (340 and 370 nm) and corresponding emission bands (∼400 and ∼450 nm, respectively) were detected. Emission bands were intensified
with time, heating and air-bubbling and converged at certain intensities, where the ∼400 nm band was red-shifted. The initially weak emission band at ∼450 nm in an alkaline solution was intensified up to the comparable intensity to the strongest emission band at ∼400 nm in an acidic
solution, after long time. While 1H NMR spectra depended on pH owing to the protonation of amine, those were slightly affected by the time, heating and air-bubbling. However, no new 1H NMR signals appeared even after long time, indicating no finding of chemical structure
change of dendrimer. This suggests that the luminescent property should result from any interaction of amine with oxygen but not the chemical reaction.
Development of Nanostructured Thermoregulating Textile Materials
Authors: Romeo Valentina , Vittoria Vittoria , Sorrentino Andrea
Published: August 2008

The present studies provide the first example of a nanostructured thermoregulating textile materials obtained by electrospinning process. Microencapsulated phase change material was dispersed into a Poly(ε-caprolactone) (PCL)-acetone solution and electrospun at ambient temperature.
The morphological analysis showed that the addition of microcapsules to the PCL lead to the formation of nanofibers with a significantly lower average diameter with respect to that obtained by pure PCL in the same conditions. The resulting functional material has demonstrated to have the higher
efficiency in the thermoregulating effect in comparison with more of the dispersion methods used up to now.
Formation of TiO2 Nanorings Due to Rapid Thermal Annealing of Swift Heavy Ion Irradiated Films
Authors: Thakurdesai Madhavi , Sulania I. , Narsale A. M. , Kanjilal D. , Bhattacharyya Varsha
Published: August 2008

Amorphous thin films of TiO2 deposited by Pulsed Laser Deposition (PLD) method are irradiated by Swift Heavy Ion (SHI) beam. The irradiated films are subsequently annealed by Rapid Thermal Annealing (RTA) method. Atomic Force Microscopy (AFM) study reveals formation of nano-rings
on the surface after RTA processing. Phase change is identified by Glancing Angle X-ray Diffraction (GAXRD) and Raman spectroscopy. Optical characterisation is carried out by UV-VIS absorption spectroscopy. Though no shift of absorption edge is observed after irradiation, RTA processing does
show redshift.
Ultrafine Cellulose Acetate Fibers with Nanoscale Structural Features
Authors: Zhang Lifeng , Hsieh You-Lo
Published: August 2008

Nano-structural features were introduced to ultrafine cellulose acetate (CA) fibers by electrospinning of its mixtures with either poly(vinyl pyrrolidone) PVP or β-cyclodextrin (β-CD) in DMF, followed by dissolution of the added PVP or β-CD. The presence
of the charge-holding PVP enabled fiber formation from CA below its entanglement chain length and improved the electrospinning efficiency to produce bicomponent fibers with wide ranging diameters from 30 to 650 nm. At up to 50% contents, the PVP in the bicomponent fibers was phase-separated
from CA and, upon removal, resulting in highly angulated fiber surfaces with nanometer-size spherulites and sub-micron size ridges and grooves. Adding β-CD to CA enabled fiber formation at concentrations below the chain entanglement concentration Ce (16.5%). Hydrogen
bonding between β-CD and CA, as evident by FTIR, helped to distribute β-CD as individual molecules in the CA matrix and producing more uniform and finer (130–150 nm in diameters) fibers, irrespective of their β-CD contents. Removal of β-CD
from the fibers originally containing 40% β-CD, generated nanoporous fibers with 2-nm nanopores and 70% increase in specific surface and doubled pore volume.
Thermally Evaporated In2O3 Nanoloquats with Tunable Broad-Band Emissions
Authors: Ko Tsung-Shine , Lu Tien-Chang , Chu Chia-Pu , Kuo Hao-Chung , Wang Shing-Chung
Published: August 2008

We describe synthesis of In2O3 nanoloquats grown by thermal evaporation under different oxygen flow rates and temperatures. Gold nanoparticles were used the catalysts and were dispersed on the silicon wafer to assist growth of In2O3 nanoloquats.
The nanostructures of In2O3 nanoloquats were characterized by scanning electron microscopy, transmission electron microscopy and X-ray diffraction. The photoluminescence study reveals that In2O3 nanoloquats could emit different broad-band luminescence
peaks in the range of 410∼620 nm by tuning different oxygen flow rates and temperatures. The wide tuning range in the emission peaks of In2O3 nanoloquats has potential in applications of white light illumination.
An Atomic Force Microscopy Study of the Interactions Between Indolicidin and Supported Planar Bilayers
Authors: Askou H. J. , Jakobsen R. N. , Fojan P.
Published: August 2008

Indolicidin, a tryptophane-rich antimicrobial peptide, was used to investigate the interactions with a zwitterionic phosphatidylcholine as a model membrane system. In situ atomic force microscopy in liquid medium and phosphatidylcholine supported planar bilayers enabled the study
of the interactions between indolicidin and the lipid membrane in real time. It was evident that indolicidin induced a continuous shrinking and thinning of the supported planar bilayers. The effect of indolicidin was dependent upon the composition and physical properties of the membrane bilayer.
The interaction of indolicidine with the membrane could be best and most pronounced seen and studied at the boundary of the gel-fluid-domains. Dye leakage experiments with phosphatidylcholine vesicles encapsulated with calcein revealed that indolicidin induced fluidisation of the lipid membrane
leading to dye release. The present study indicates that the mode of action for indolicidin can be best described by a stepwise interaction of the peptide with the membrane. Formation of pores however can not be supported on the basis of our experiments.
Template Synthesis of Indium Nanowires Using Anodic Aluminum Oxide Membranes
Authors: Chen Feng , Kitai Adrian H.
Published: August 2008

Indium nanowires with diameters approximately 300 nm have been synthesized by a hydraulic pressure technique using anodic aluminum oxide (AAO) templates. The indium melt is injected into the AAO template and solidified to form nanostructures. The nanowires are dense, continuous and
uniformly run through the entire ∼60 μm thickness of the AAO template. X-ray diffraction (XRD) reveals that the nanowires are polycrystalline with a preferred orientation. SEM is performed to characterize the morphology of the nanowires.
Preparation and Characterizations of ZnO Nanotubes by Acidic Etching Nanowires
Authors: Yao C. Y. , Chen G. J. , Tseng T. Y.
Published: August 2008

Single crystalline ZnO nanowires were synthesized by hydrothermal process and then formed nanotubes by acidic etching these nanowires in acetic solution at 85 °C. The nanotube diameter can be easily controlled by dividing the nanowires growth and etching process. The ZnO nanotubes
remain single crystalline hexagonal structure after the etching process. The defects existed in the nanowires and the dangling bonds of the nanowires' surface play the important roles for the etching process. An etching model for forming ZnO nanotubes is proposed, which can be proved by our
experimental results.
Optical Properties of Ce-Doped ZnO Nanowires Directionally Grown by Hydrothermal Method
Authors: Chen Y. S. , Tseng T. Y.
Published: August 2008

Well directionally grown Ce-doped ZnO nanowires were successfully synthesized by a simple hydrothermal method. The Ce dopant plays a key role in evolving the morphology, affecting the crystalline size, and forming the uniform nanostructure of the ZnO nanowires. The amount of Ce dopant
in the ZnO nanowires also affects the regions of blue-shift in the UV and green emission peaks and the intensities of emission peaks based on the cathodoluminescence spectra of the nanowires. Moreover, the effect of Ce doping amount on the microstructure of the nanowires is also presented.
Novel 1,3-Diketone Modified Fullerenes for Organic Photovoltaic Cells
Authors: Lee Hak Sung , Yoon Sung Cheol , Lim Jongsun , Lee Myongsoo , Lee Changjin
Published: August 2008

The feasibility of novel 1,3-diketone modified C60s (compound 1 and 2) was studied as acceptor materials in organic photovoltaic cells (OPVC). 1,3-Diketone modified fullerenes were synthesized by the addition reaction of 1,3-bis(5′-hexylthiophen-2′-yl)propane-1,3-dione
with C60 in the presence of DBU (1,8-diazabicyclo[5,4,0]undec-7-ene). From this procedure two products can be prepared, which are mono- (1) and di-substituted compound (2) in the yield of 40% and 17%, respectively. OPVCs fabricated by using the mixture
of P3HT and compound 1 as an active layer showed excellent power conversion efficiency of about 3.42% after annealed at 160 °C for 15 min and we believe that substantial improvements can be realized by nano-structured heterojunction. It was demonstrated that 1,3-diketone modified
C60 (compound 1) was one of the promising candidates for acceptor materials for OPVCs.
Glucose Sensor Based on Glucose Oxidase-Lipid LB Film Immobilized in Prussian Blue Layer
Authors: Lee Dong-Yun , Kafi A. K. M. , Choi Won-Suk , Park Sang-Hyun , Kwon Young-Soo
Published: August 2008

The structure and dynamic organization of a mixed Langmuir film of glucose oxidase (GOx) and lipid at the air–water interface were studied. The film was transferred onto the Prussian Blue (PB)-modified Pt electrode for biosensor preparation. The PB modified electrode showed well
defined redox peaks in 0.1 M PBS electrolyte. The Langmuir film was characterized at the air–water interface by π-A isotherms. The mixed monolayer was formed by spreading GOx on the LB trough covered with lipid. Time-pressure results show that at least 90 minutes are required
to reach the equilibrium state of GOx-lipid film. The monolayer was transferred onto the PB-modified electrode when surface pressure was 40 mN/m. This sensor was characterized by a very low detection limit and a wide linear range. The optimal conditions for both fabricating and response of
the sensor were investigated. The proposed biosensor showed a linear calibration range from 5 × 10−6 to 6 × 10−5 M. The detection limit was determined to be 1.5 × 10−6 M.
Synthesis and Characterization of Polystyrene-Supported FePt Nanoparticles and CdS Quantum Dots
Authors: Moon Je Yong , Chang Yongmin , Park Jeunghee , Lee Gang Ho
Published: August 2008

We present a general method of supporting nanoparticles by using polymers. As a demonstration, a polystyrene was employed to rigidly support the superparamagnetic FePt nanoparticles and CdS QDs. We successfully fabricated the FePt nanoparticles and CdS QDs rigidly supported in a polystyrene
matrix by directly blending the FePt nanoparticles and CdS QDs with the polystyrene at melt state of polystyrene. We characterized them with TEM, XRD, and PL spectrometer.
Effect of Solvent and Dopant on Poly(3,4-ethylenedioxythiophene) Thin Films by Atomic Force Microscope Lithography
Authors: Kim Yong-il , Kim Hyunsook , Lee Haiwon
Published: August 2008

AMF anodization lithography was performed on organic thin films with conducting polymers which is poly(3,4-ethylenedioxythiophene). The conductivity of PEDOT thin films was changed by different dopants and organic solvents. Two different dopants are poly(4-styrenesulfonate) and di(2-ethylhexyl)-sulfosuccinate.
Also, DMF and IPA were used to prepare the PEDOT thin films doped with PSS and DEHS on silicon surface. The conductivities of these PEDOT variants were compared by obtaining their I–V curves between tip and thin films using AFM. Silicon oxide nanopatterns with higher aspect
ratios can be obtained from the films with higher conductivity.
Structural, Optical, and Electrical Properties of Semiconducting ZnO Nanosheets
Authors: Park Jae-Hwan , Kang Gyo-Sung , Kwon Soon-Il , Lim Dong-Gun , Choi Young-Jin , Choi Kyoung-Jin , Park Jae-Gwan
Published: August 2008

ZnO nanosheets were fabricated by an oxygen-assisted carbothermal reduction process and their properties were evaluated. In particular, the FET characteristics and photoluminescence properties of ZnO nanosheets were evaluated. The conduction type of ZnO nanosheets was determined as
an n-type and the mobility was 20∼40 cm2/V-s, which is fairly high compared to ZnO nanowires. This might be attributed to the wide conduction area of ZnO nanosheet compared to nanowire structures and their better crystallinity.
Gas-Phase Formation of Self-Assembled Monolayers on MgO for Protection Against Hydration
Authors: Lee Byoung H. , Sung Myung M.
Published: August 2008

The gas-phase adsorption of octyltrichlorosilane onto MgO produces self-assembled monolayers that can provide protection against hydration of the underlying MgO surfaces. MgO thin film has attracted attention for application as a protecting layer of alternating current plasma display
panel. On exposure to air, the clean MgO surface interacts with water and quickly hydrates to Mg(OH)2, which reduces the secondary electron emission yield. The gas-phase deposition of octyltrichlorosilane on the clean MgO has produced self-assembled monolayers because of high reactivity
of the MgO surface. The ultra-thin organic layer of the octylsiloxane can provide significant protection against hydration to the MgO surface, and improves secondary electron emission yield for the MgO samples. The secondary electron emission coefficient for the monolayer-coated MgO sample
is about 25% higher than that for the clean MgO after 24 hr exposing to air.
Nanostructured Change of SIS (Styrene-Isoprene-Styrene) Triblock Copolymer by Elongational Flow
Authors: Lee Won Ki , Lim Hyotaek , Kim Eun Young
Published: August 2008

Elongation deformation was conducted on a polystyrene-block-polyisoprene-block-polystyrene (SIS) triblock copolymer which contains cylindrical microdomains composed of polystyrene block chains in matrix of polyisoprene block chains. The extensional flow behavior of this deformation
triblock copolymer melt, which exhibits a cylindrical phase, has been examined by using elongational deformation with εo between 0.1 and 1.0 s−1 at different temperatures. The structures related to various condition of elongational flow deformation has
been determined from SAXS patterns by considering separately changes in the single particle scattering, which influence the scattering patterns. The TEM and SAXS data of the samples show that the cylindrical PS-domain was deformed along the direction of elongation. It also shows that the cylindrical
microdomains are micronecked and deformed with various strain rates.
Study of the Magnetic Phase of Fe-Pt Alloy Nanoparticles
Authors: Cha Hyungil , Kim Younghwan , Kim Changwoo , Kang Youngsoo
Published: August 2008

High temperature solution phase decomposition of Fe(CO)5 and reduction of Pt(acac)2 in the presence of stabilizers of oleic acid and oleyl amine are employed to produce Fe1–xPtx alloy nanoparticles. The Fe and Pt composition
of the nanosized materials can be tuned by adjusting the molar ratio of Fe(CO)5 to Pt(acac)2, and the compositions ranging from Fe40Pt60 to Fe80Pt20 are obtained. This study is to investigate the influence of the composition
on Curie temperature (Tc) of Fe1–xPtx nanoparticles monitored by thermomagnetic analysis (TMA).
Immobilization, Hybridization and Amperometric Detection of DNA Sensor Using Quartz Crystal Microbalance
Authors: Lee Dong-Yun , Choi Won-Suk , Kafi A. K. M. , Park Sang-Hyun , Kwon Young-Soo
Published: August 2008

A synthesized 21-mer single-stranded DNA (ssDNA) was covalently immobilized onto a self-assembled aminoethanethiol monolayer modified gold electrode onto quartz crystal microbalance (QCM). The covalently immobilized ssDNA was hybridized with complementary ssDNA. The interaction between
surface-immobilized ssDNA and complementary 21-mer DNA in solution was also examined. Each step was followed by monitoring changes in the QCM frequency over time. From the results, the measured frequency change was about 256 Hz, 160 Hz and 141 Hz, respectively. As a result, the adsorption
mass was about 273 ng/cm2, 171 ng/cm2 and 151 ng/cm2, according to the Sauerbrey equation. Also, PBS with pH 7.0 was selected as a supporting electrolyte to achieve maximum sensitivity and good bioactivity. The anodic peak current was linearly related to the
concentrations between 1 × 10−5 and 9 × 10−5 M with a detection limit of 1.0 × 10 −6 M.
High Performance Thin Film Transistor with ZnO Channel Layer Deposited by DC Magnetron Sputtering
Authors: Moon Yeon-Keon , Moon Dae-Yong , Lee Sang-Ho , Jeong Chang-Oh , Park Jong-Wan
Published: August 2008

Research in large area electronics,1 especially for low-temperature plastic substrates, focuses commonly on limitations of the semiconductor in thin film transistors (TFTs), in particular its low mobility. ZnO is an emerging example of a semiconductor material for TFTs that
can have high mobility, while a-Si and organic semiconductors have low mobility (<1 cm2/Vs).2–5 ZnO-based TFTs have achieved high mobility, along with low-voltage operation low off-state current, and low gate leakage current. In general, ZnO thin films for the
channel layer of TFTs are deposited with RF magnetron sputtering methods. On the other hand, we studied ZnO thin films deposited with DC magnetron sputtering for the channel layer of TFTs. After analyzing the basic physical and chemical properties of ZnO thin films, we fabricated a TFT-unit
cell using ZnO thin films for the channel layer. The field effect mobility (μsat) of 1.8 cm2/Vs and threshold voltage (Vth) of −0.7 V were obtained.