bluuebunny/crossref_metadata_2025 huggingface dataset:
TRANSMISSIVE PROPERTIES IN 1D RANDOM DIMER RESONATORS: APPLICATION TO THE FILTERING OF MECHANICAL WAVES
Authors: BOUHAFS F. , ZEKRI N.
Published: July 2002

We study the transmissive and spectral properties of mechanical waves in a 1D random system with correlated disorder. The system considered is a string regularly loaded by two kinds of resonators, one of which appears randomly in pairs. We show the existence of unity resonant transmission peaks, corresponding to extended modes. Each resonance width is controlled by the mass of the dimer resonator and the size of the system. This system seems to be a good filter for mechanical waves and the model can be extended to acoustical waves.
Optical Phonons in Cubic AlxGa1-xM Approached by the Modified Random Element Isodisplacement Model
Authors: Liu Ming S. , Bursill L. A. , Prawer S.
Published: July 2002

The behavior of longitudinal and transverse optical phonons in cubic Al x Ga 1-x N are derived theoretically as a function of the concentration x(0≤x≤1). The calculation is based on a Modified Random Element Isodisplacement model which considers the interactions from the nearest neighbor and second neighbor atoms. We find one-mode behavior in Al x Ga 1-x N where the phonon frequency in general varies continuously and approximately linearly with x.
COMPLETE RENORMALIZATION BEYOND THE CONVENTIONAL PROCEDURE IN BOTH NONRELATIVISTIC AND RELATIVISTIC QED
Authors: SEKE JOSIP
Published: July 2002

A new unambiguous (unified nonrelativistic-relativistic) renormalization method, going beyond the conventional one, is formulated. Without introducing any artifical mass (or energy) counter-terms in the Hamiltonian, the terms stemming from the experimentally unobservable interaction of the free electron (and fermionic vacuum) with the vacuum radiation field are directly identified and completely eliminated in the corresponding equations of motion for the bound electron.
STABILIZING HIGHER PERIODIC ORBITS OF CHAOTIC DISCRETE-TIME MAPS
Authors: LENZ HENNING , OBRADOVIC DRAGAN
Published: July 2002

This paper presents two controller design methods for stabilizing higher periodic orbits of chaotic, discrete-time systems: transformation to the controller canonical form and multiparameter control. Each method is based on the locally linearized system representation. Accordingly, each method explicitly addresses the problem of control of a linear time-varying system and therefore produces a time-varying controller. The freedom in the design of the time-varying controller is used to optimize the properties of the closed loop system. The controller design methods are applied to the Hénon map and the Ikeda map for stabilizing orbits of periods 7, 11, 13, and 31, respectively. The issue of measurement noise is also considered.
HOPF BIFURCATION OF TIME-DELAY LIENARD EQUATIONS
Authors: XU JIAN , LU QI-SHAO
Published: July 2002

The linearized stability and Hopf bifurcation of the delay Lienard equations are studied. The linearized asymptotic stability for the null solution of the equations with two parameters is analyzed. The Hopf bifurcation and the stability of periodic solutions are investigated by constructing the center manifold and using the normal form method. Several examples for typical nonlinear delay Lienard equations are given to show the coincidence between the theoretical analysis and the numerical results.
UNIVERSAL CELLULAR AUTOMATON OVER A HEXAGONAL TILING WITH 3 STATES
Authors: GAJARDO A. , GOLES E.
Published: July 2002

A universal three-state three-neighbor cellular automaton will be constructed. The space selected for this cellular automaton is a hexagonal tiling where the cells are in the vertices and the neighbors are the three nearest cells. We define the local transition rule as well as the basic elements that will aid to build digital circuits and, by the way, prove the universality of this cellular automaton. The local transition rule is defined to be isotropic.
ORTHODOX TRANSVERSALS OF REGULAR SEMIGROUPS
Authors: CHEN J. F. , CUO Y. Q.
Published: July 2002

Orthodox transversals were introduced by the first author as a generalization of inverse transversals [Comm. Algebra 27(9) (1999), pp. 4275–4288]. One of our aims in this note is to consider the general case of orthodox transversals. The main results are on the sets I and Λ, two components of regular semigroups with orthodox transversals. We prove that the semibands Ī and [Formula: see text] generated by I and Λ respectively are bands. Also somewhat interesting generalizations of properties on orthodox semigroups are given; another aim in this note is to give some examples illustrating the situations that the class of regular semigroups with orthodox transversals properly includes the class of regular semigroups with inverse transversals as well as the class of orthodox semigroups.
CONFORMAL COLLINEATIONS AND RICCI INHERITANCE SYMMETRY IN STRING CLOUD AND STRING FLUIDS
Authors: CAMCI UĞUR
Published: July 2002

Conformal collineations (a generalization of conformal motion) and Ricci inheritance collineations, defined by £ξRab=2α Rab, for string cloud and string fluids in general relativity are studied. By investigating the kinematical and dynamical properties of such fluids and using the field equations, some recent studies on the restrictions imposed by conformal collineations are extended, and new results are found.
STATIC DOMAIN WALLS IN BRANS–DICKE THEORY
Authors: BANERJEE A. , GHOSH TANWI
Published: July 2002

It is already known that the equations of General Relativity are not consistent with Static Domain Wall which is described by the energy momentum Tensor [Formula: see text] and [Formula: see text]. Here it is shown that even in Brans–Dicke Theory of Gravitation the static domain wall with either p = 0 or p = ∊ρ does not exist. In the latter case, we have used the property of reflection symmetry of the wall about x = 0 as well as a general relation between g00 and the Brans–Dicke scalar field and have shown that the metric component g00 changes sign somewhere as we move away from the symmetry plane.
SITE AND INTERACTION DEPENDENCE OF NUCLEAR STIMULATED DESORPTION FROM STRUCTURED SURFACES
Authors: ASHKENAZY Y. , KELSON I.
Published: July 2002

Molecular dynamics calculations of low energy Nuclear Stimulated Desorption (NSD) of 107 Cd from a palladium substrate are presented. The characteristics of the desorption probability are shown to be related both to the site occupied by the 107 Cd and to the adsorbate–substrate interaction. The quantitative implications of the theoretical calculations to a specific experimental scenario are discussed, based on preliminary measurements of 107 Cd desorption from palladium.
RHEED INVESTIGATION OF Pd/Al BIMETALLIC SYSTEM ON KCl(001) SUBSTRATE
Authors: MASEK K. , MOROZ V. , MATOLÍN V.
Published: July 2002

Pd/Al alloys have very interesting properties from the point of view of their possible application in heterogeneous catalysis. Preparation of small heteroepitaxial Pd/Al alloy particles opens a new way in studies of the influence of Pd/Al crystallographic structure on the alloy catalytic properties.

Pd/Al alloy particles were grown by the molecular beam epitaxy method. Their crystallographical structure was controlled by reflection high energy electron diffraction (RHEED). It was found that Pd deposited on epitaxial 3D Al particles grown on KCl is intermixing with Al. This process is accompanied by the variation of lattice parameter from the Al value to the Pd one.
THE EVALUATION OF PRE- AND POST-OPERATIVE CLASSIFICATION SYSTEM FOR CUBITAL TUNNEL SYNDROME
Authors: Asami Akihiko
Published: July 2002

Pre- and post-operative classification systems for cubital tunnel syndrome are discussed in this study. Although there are several pre-operative evaluations, a suitable system should be easy to categorise, simple, reliable and reproducible. McGowan's grading system has been widely used for these reasons; however, grade II included complicated cases. Accordingly, McGowan's grade II is divided into two groups, such as grade II-A (relatively good prognostic group) and group II-B (relatively poor prognostic group). As far as the post-operative classification system is concerned, 4 grade (excellent, good, fair, and poor) classification is the most useful and easy to understand.
AWARENESS PROVISIONING IN COLLABORATION MANAGEMENT
Authors: BAKER DONALD , GEORGAKOPOULOS DIMITRIOS , SCHUSTER HANS , CICHOCKI ANDRZEJ
Published: July 2002

Collaboration management involves capturing the collaboration process, coordinating the activities of the participating applications and humans, and/or providing awareness, i.e. information that is highly relevant to a specific role and situation of a process participant. In this paper, we propose an awareness provisioning solution that allows focusing, customizing, and temporally constraining the awareness delivered to each process participant. Unlike existing collaboration management technologies (such as workflow and groupware) that provide only a few built-in awareness choices, the proposed awareness solution allows the specification of what information is to be given to what users and at what time. To support this advanced level of awareness, we require the definition of awareness roles and the specification of corresponding awareness descriptions. Awareness roles can be dynamically created and associated with any process scope. Awareness descriptions define what information is to be given to users in an awareness role. Since awareness roles are created or become visible when they are needed, the existence of an awareness role also determines the appropriate time interval during which the information specified in the awareness description can be delivered. This awareness provisioning approach minimizes information overloading and allows the combination of process-relevant information with external information as needed by the process participants. The proposed awareness provisioning solution is employed by the Collaboration Management Infrastructure (CMI), a federated system for collaboration process management. In this paper, we introduce an Awareness Model (AM) for creating awareness specifications and defining related execution semantics. Awareness specifications in AM are specialized composite event specifications that define patterns of process-related events and external events, as well as how information should be digested from them. We also describe the implementation of CMI's awareness provisioning engine and related tools.
BRINGING REAL AND VIRTUAL WORLDS TOGETHER IN THE MANUFACTURING PROCESS
Authors: DIETRICH UTE , SCHULZ THOMAS , YARAMANOGLU NEZIH
Published: July 2002

A wide spectrum of IT-tools and a variety of different systems are currently in place to provide best-in-class solutions for planning and executing manufacturing tasks. Among such applications, simulation systems play a major role in the areas of manufacturing planning and quality assurance, as well as process optimization. These systems are found in most production environments. Typically, simulation systems help to anticipate the behavior of physical systems and review the design and planning data. Today, the major automotive companies and their IT-vendors work on concepts to cover the entire process of production. However, there are still technological limitations originating from the inadequate information flow between the real and virtual worlds. A number of research projects focus on the improvement of planning processes by feeding information on life cycle conditions back to the simulation environment or bringing simulation functionality closer to manufacturing processes.

The following article extracts some examples from the area of simulation systems research with a focus on the manufacturing environment and related task areas. Application cases are presented as sample scenarios for the integrated operation of virtual and real processes.
Fast algorithms for generating discrete random variates with changing distributions
Authors: Rajasekaran Sanguthevar , Ross Keith W.
Published: July 2002

One of the most fundamental operations when simulating a stochastic discrete-event dynamic system is the generation of a nonuniform discrete random variate. The simplest form of this operation can be stated as follows: Generate a random variable X that is distributed over the integers 1,2,…,
n
such that P(X=
i
) =

a
i

/(
a
1
+…+

a
n

), where

a
i

's are fixed nonnegative numbers. The well-known “alias algorithm” is available to accomplish this task in O(1) time. A more difficult problem is to generate variates for X when the

a
i

's are changing with time. We present three rejection-based algorithms for this task, and for each algorithm we characterize the performance in terms of acceptance probability and the expected effort to generate a variate. We show that, under fairly unrestrictive conditions, the long-run expected effort is O(1). Applications to Markovian queuing networks are discussed. We also compare the three algorithms with competing schemes appearing in the literature.
Linear approximation of shortest superstrings
Authors: Blum Avrim , Jiang Tao , Li Ming , Tromp John , Yannakakis Mihalis
Published: July 2002

We consider the following problem: given a collection of strings

s
1

,…,

s
m

, find the shortest string
s
such that each

s
i

appears as a substring (a consecutive block) of
s
. Although this problem is known to be NP-hard, a simple greedy procedure appears to do quite well and is routinely used in DNA sequencing and data compression practice, namely: repeatedly merge the pair of (distinct) strings with maximum overlap until only one string remains. Let
n
denote the length of the optimal superstring. A common conjecture states that the above greedy procedure produces a superstring of length
O(n)
(in fact, 2
n
), yet the only previous nontrivial bound known for any polynomial-time algorithm is a recent
O(n
log
n
) result.

We show that the greedy algorithm does in fact achieve a constant factor approximation, proving an upper bound of 4
n
. Furthermore, we present a simple modified version of the greedy algorithm that we show produces a superstring of length at most 3
n
. We also show the superstring problem to be MAXSNP-hard, which implies that a polynomial-time approximation scheme for this problem is unlikely.
Extending relational algebra and relational calculus with set-valued attributes and aggregate functions
Authors: Özsoyoğlu G. , Özsoyoğlu Z. M. , Matos V.
Published: July 2002

In commercial network database management systems, set-valued fields and aggregate functions are commonly supported. However, the relational database model, as defined by Codd, does not include set-valued attributes or aggregate functions. Recently, Klug extended the relational model by incorporating aggregate functions and by defining relational algebra and calculus languages.

In this paper, relational algebra and relational calculus database query languages (as defined by Klug) are extended to manipulate set-valued attributes and to utilize aggregate functions. The expressive power of the extended languages is shown to be equivalent. We extend the relational algebra with three new operators, namely, pack, unpack, and aggregation-by-template. The extended languages form a theoretical framework for statistical database query languages.
Optimal attack and reinforcement of a network
Authors: Cunningham William H.
Published: July 2002

In a nonnegative edge-weighted network, the weight of an edge represents the effort required by an attacker to destroy the edge, and the attacker derives a benefit for each new component created by destroying edges. The attacker may want to minimize over subsets of edges the difference between (or the ratio of) the effort incurred and the benefit received. This idea leads to the definition of the “strength” of the network, a measure of the resistance of the network to such attacks. Efficient algorithms for the optimal attack problem, the problem of computing the strength, and the problem of finding a minimum cost “reinforcement” to achieve a desired strength are given. These problems are also solved for a different model, in which the attacker wants to separate vertices from a fixed central vertex.
Modern Integrations of Solar System Dynamics
Authors: Morbidelli A.
Published: July 2002

▪ Abstract  Until the early 1990s, numerical simulations of Solar System dynamics were done using accurate but slow integrators. The typical timescales were on the order of a million years, apart from exceptions achieved by considering averaged equations or using specifically designed supercomputers. In the last decade, new numerical integration methods for Solar System dynamics have been introduced. The mixed variable symplectic method ( Wisdom & Holman 1991 ) has permitted the study, in the absence of close encounters, of the evolution of planets and small bodies on timescales comparable to the age of the Solar System. The regularized mixed variable scheme ( Levison & Duncan 1994 ) has allowed the compilation of statistics on the evolution of thousands of near-Earth asteroids and comets, from their source regions to their dynamical elimination. The Symba and the Mercury codes ( Duncan et al. 1998 , Chambers 1999 ), which treat close encounters between massive bodies in a symplectic way, have permitted the simulations of planetary accretion and of the early phase of the highly chaotic evolution of the Solar System. This paper reviews the most exciting results obtained with these new integrators. Emphasis is given to the conceptual steps that these works represent in our understanding of Solar System dynamics.
THE ROLE OFhrpGENES DURING PLANT-BACTERIAL INTERACTIONS
Authors: Lindgren Peter B.
Published: July 2002

▪ Abstract  hrp genes control the ability of phytopathogenic bacteria to cause disease and to elicit hypersensitive reactions on resistant plants. Genetic and biochemical studies have demonstrated that Hrp proteins are components of Type III secretion systems, regulatory proteins, proteinaceous elicitors of the hypersensitive reaction, and enzymes needed for synthesis of periplasmic glucans. Significantly, Type III secretion systems are involved with the secretion of pathogenicity proteins in bacterial pathogens of animals. The transcriptional activation of a number of bacterial avirulence (avr) genes is controlled by Hrp regulatory proteins, and recent experimental evidence suggests that Avr proteins may be transported by Hrp secretion systems. It has also been hypothesized that pathogenicity and/or virulence gene products exit bacterial phytopathogens via Hrp pathways. Thus, hrp genes may be one of the most important groups of genes found in phytopathogenic bacteria in relationship to pathogenicity and host range.
A VR-Human Interface for Assisting Human Input in Path Planning for Telerobots
Authors: Bhatia Praveen , Uchiyama Masaru
Published: July 2002

In telerobotic systems, human beings are required to provide input to the telerobot. It is very difficult to provide accurate and smooth input paths quickly through the master arm and avoid collisions. These problems are further compounded by time-delay when the distances involved are large (for example, in the case of space exploration). If an intermediate VR system can modify the human input to provide smooth, collision-free paths, the intuitive capabilities of human beings to identify a feasible path can be quickly combined with the machine's ability to modify the colliding segments to noncolliding ones. We call this synthesis shared intelligence.

This paper develops the strategies and mathematics to implement this concept of shared intelligence in path planning, using a VR interface in which human and machine abilities are combined appropriately. Shared intelligence unburdens the human operator from precisely and accurately inputting the planned path. With the help of the free space developed for a simple telerobot, it is shown how the human input is converted into parameterized paths in the configuration space, checked for collisions, and automatically modified into collision-free paths using repulsive fields introduced in the configuration space. Simulations and experimental results are also shown to illustrate these concepts.
THE REBIRTH OF MYTH?: NIETZSCHE'S ETERNAL RECURRENCE AND ITS ROMANTIC ANTECEDENTS
Authors: Yelle Robert
Published: July 2002

There is increasing evidence of the influence of various Romantic thinkers on Nietzsche's early philosophy, especially on The Birth of Tragedy, with its announcement or prediction of a rebirth of myth. The prophetic Thus Spoke Zarathustra, which Nietzsche introduced with the words "tragedy begins," expresses his later philosophy, particularly his central doctrine of the Eternal Recurrence, in symbols, parables, and riddles, suggesting an attempt at mythopoeia. However, the critical, ironic, and parodying elements in Nietzsche's later philosophy have led to its characterization as "antimyth." This essay demonstrates that Nietzsche's idea and symbolism of the Eternal Recurrence as a temporal cycle of opposites represented by various forms of the circle, especially the ouroborus or serpent biting its own tail, and associated with Zoroaster, Heraclitus, and Dionysus, was influenced by the tradition of Romantic mythology. Before the publication of The Birth of Tragedy, Nietzsche encountered the writings of Johann Jakob Bachofen and Friedrich Creuzer, where the cycle of opposites is identified as a specifically mythic idea, which developed later into a philosophy, as metonymically represented in the relationship between the myth-maker Zoroaster and the philosopher Heraclitus. In The Birth of Tragedy, the cycle of opposites became for Nietzsche a symbol of the unity of myth and philosophy, and the rebirth of the former from the self-overcoming of the latter. This symbol continued to serve Nietzsche throughout his career as a model for his own development as a philosopher. The Eternal Recurrence appears to have been his own attempt to unite myth and philosophy, through the transformation of an originally Romantic mythological idea into its opposite, and the adoption of a symbolic and "mythic" style of expression.
Wholly Hypothetical Syllogisms
Authors: Bobzien Susanne
Published: July 2002

In antiquity we encounter a distinction of two types of hypothetical syllogisms. One type are the 'mixed hypothetical syllogisms'. The other type is the one to which the present paper is devoted. These arguments went by the name of 'wholly hypothetical syllogisms'. They were thought to make up a self-contained system of valid arguments. Their paradigm case consists of two conditionals as premisses, and a third as conclusion. Their presentation, either schematically or by example, varies in different authors. For instance, we find 'If (it is) A, (it is) B; if (it is) B, (it is) C; therefore, if (it is) A, (it is) C'. The main contentious point about these arguments is what the ancients thought their logical form was. Are A, B, C schematic letters for terms or propositions? Is 'is', where it occurs, predicative, existential, or veridical? That is, should 'Α στι' be translated as 'it is an A', 'A exists', 'As exist' or 'It is true/the case that A'? If A, B, C are term letters, and 'is' is predicative, are the conditionals quanti ed propositions or do they contain designators? If one cannot answer these questions, one can hardly claim to know what sort of arguments the wholly hypothetical syllogisms were. In fact, all the above-mentioned possibilities have been taken to describe them correctly. In this paper I argue that it would be mistaken to assume that in antiquity there was one prevalent understanding of the logical form of these arguments even if the ancients thought they were all talking about the same kind of argument. Rather, there was a complex development in their understanding, starting from a term-logical conception and leading to a propositional-logical one. I trace this development from Aristotle to Philoponus and set out the deductive system on which the logic of the wholly hypothetical syllogisms was grounded.
Aristote et la question du droit naturel
Authors: Destrée Pierre
Published: July 2002

présente étude propose une interprétation de EN , V, 10, en défendant deux premièrement que la notion centrale de la variabilité du droit naturel e la diversité des interprétations que l'on peut donner d'un sentiment communément partagé du juste ou de l'injuste (cf. Rhét., I, 13); deuxièmement que, échapper au relativisme de type protagoréen, Aristote défend l'idée d'un parfait qui seul peut fournir la meilleure interprétation de ce sentiment.
Interspecific differences in the fine structure of the body cuticle of Trichodoridae Thorne, 1935 (Nematoda: Diphtherophorina) and review of anchoring structures of the epidermis
Authors: Decraemer Wilfrida , Brown Derek , Karanastasi Eirini , Zheng Jingwu , Martins De Almeida Maria Teresa
Published: July 2002

Examination of the fine structure of the body cuticle of Trichodorus cylindricus , T. nanjingensis, T. pakistanensis , T. primitivus, Paratrichodorus anemones , P.hispanus , P.minor , P.pachydermus , P.porosus and P.teres revealed three distinct types, each characterised by differences in layers 4 to 6. A new description is provided for layer 5 and the presence of intracuticular canals and hemidesmosomes as types of anchoring structures for the epidermis are discussed.
Effects of nutrient source on the physiological mechanisms of Heterodera glycines and soybean genotypes interactions
Authors: Melakeberhan Haddish
Published: July 2002

The effect of Heterodera glycines on H. glycines -resistant 'Bryan', susceptible-tolerant 'G88-20092', and susceptible-intolerant 'Tracy M' soybean cultivars grown in Hoagland solution (HS), HS without nitrogen (HS-N), or water treatments was studied for 25 to 26 days under greenhouse conditions (28 +/- 2 degrees C). Few of the 15 000 eggs per 800 cm3 soil infected 'Bryan' while 'G88-20092' and 'Tracy M' were severely infected, and photosynthesized and grew less in water and HS-N. Although less than the controls, photosynthetic rate in HS treatments was more than in water or HS-N. Nodulation was less in H. glycines than in the controls, and in HS than in water and HS-N treatments. However, more nitrogen was present in soil from HS than from HS-N or water treatments. Generally, cysts developed slower and had fewer eggs in HS followed by HS-N than in the water treatments. The results support the hypothesis that nematode infected plants do better under balanced nutrition than under nutrient deficient conditions. It is postulated that the slowed-down nematode development and/or diminished reproductive potential might be host-mediated. Effets de l'origine des elements nutritifs sur les mecanismes physiologiques des interactions entre Heterodera glycines et des genotypes de soja - L'effet d'Heterodera glycines sur les cultivars resistant "Bryan", susceptible-tolerant "G88-200092" et susceptible-non tolerant "Tracy M" cultives dans la solution d'Hoagland (HS), HS sans azote (HS-N) ou dans l'eau a ete etudie pendant 25 a 26 jours sous serre (28 +/- 2 degrees C). Quelques uns seulement des 15 000 oeufs par 800 cm3 de sol ont infeste le cultivar "Bryan" tandis que "G88-20092" et "Tracy M" ont ete severement infestes avec une photosynthese et une croissance plus faible pour les traitements eau et HS-N. Bien qu'inferieur a celui des temoins, le taux de photosynthese pour le traitement HS a ete plus eleve que pour les traitements eau et HS-N. De plus, la quantite d'azote presente dans le sol a ete plus elevee pour le traitement HS que pour les traitements HS-N ou eau. Generalement, les kystes se sont developpes plus lentement avec un nombre d'oeufs plus faible dans le traitement HS que pour les traitements HS-N et eau. Les resultats confirment l'hypothese selon laquelle les plantes infestees par le nematode se comportent mieux en conditions nutritives equilibrees qu'en conditions nutritives deficientes. Il est postule que le ralentissement du developpement du nematode et/ou la reduction de son potentiel reproducteur pourrait etre sous la dependance de l'hote.
Alkylammonium characterization of smectite alteration in the Tertiary basins of southeast Korea
Authors: Ko J. , Lee G. H. , Moon H.-S. , Song Y.
Published: July 2002

The layer charge characteristics of smectite from the Tertiary basins in the Pohang area, Korea have been studied in detail using the alkylammonium method. On the basis of layer charges, the smectite in the Pohang area can be classed as normal and high-charge (hc) smectite. The layer charge of the normal smectite averages 0.3, and ranges from 0.25 to 0.38/half unit-cell. The hcsmectite collapses on K saturation to become illite-like material and shows 10 Åseries reflections on X-ray diffraction. The layer charge of the hc-smectite ranges from 0.5 to 1. The layer charges do not appear to be related to stratification or to basins of occurrence. The diagenetic trend that may have existed in the region was probably disturbed by later volcanic activity. A systematic change in layer charge and geochemistry of smectite in Waeup illustrates that the heat and solutions associated with the volcanic activity may have played a role in the development of layer charge.
Fine-grained weathering products in waste disposal from two sulphide mines in the northern Apennines, Italy
Authors: Dinelli E. , Morandi N. , Tateo F.
Published: July 2002

From mineralogical and chemical characterization of two waste-rock piles from Vigonzano and Libiola sulphide mines in the northern Apennines, two types of fine-grained weathering products were recognized, One, from the Vigonzano mine, has a typical blue colour and consists of the Cu-Al sulphate of the woodwardite group. Its formation is related to an alkaline geochemical barrier, it is rather stable in acidic solution, and it controls Cu and Zn dispersion in the surrounding environment. The other group of sediments has a typical ochreous colour. Vigonzano samples consist mostly of goethite, whereas ferrihydrite is abundant in the Libiola sample. The ochreous sediments are enriched in Co, As, Mo, Se and Mn, thus significantly reducing the potential environmental hazard of the site, whereas solubility tests indicated possible problems due to AI dissolution at Libiola.
Accentuated response to phenylhydrazine and erythropoietin in mice genetically impaired for their GATA-1 expression (GATA-1low mice)
Authors: Vannucchi Alessandro Maria , Bianchi Lucia , Cellai Cristina , Paoletti Francesco , Carrai Valentina , Calzolari Anna , Centurione Lucia , Lorenzini Rodolfo , Carta Claudio , Alfani Elena , Sanchez Massimo , Migliaccio Giovanni , Migliaccio Anna Rita
Published: July 2002

The response of mice genetically unable to up-regulate GATA-1 expression (GATA-1low mice) to acute (phenylhydrazine [PHZ]–induced anemia) and chronic (in vivo treatment for 5 days with 10 U erythropoietin [EPO] per mouse) erythroid stimuli was investigated. Adult GATA-1low mice are profoundly thrombocytopenic (platelet counts [× 109/L] 82.0 ± 28.0 vs 840 ± 170.0 of their control littermates, P < .001) but have a normal hematocrit (Hct) (approximately .47 proportion of 1.0 [47%]). The spleens of these mutants are 2.5-fold larger than normal and contain 5-fold more megakaryocytic (4A5+), erythroid (TER-119+), and bipotent (erythroid/megakaryocytic, TER-119+/4A5+) precursor cells. Both the marrow and the spleen of these animals contain higher frequencies of burst-forming units–erythroid (BFU-E)– and colony-forming units–erythroid (CFU-E)–derived colonies (2-fold and 6-fold, respectively) than their normal littermates. The GATA-1low mice recover 2 days faster from the PHZ-induced anemia than their normal littermates (P < .01). In response to EPO, the Hct of the GATA-1low mice raised to .68 proportion of 1.0 (68%) vs the .55 proportion of 1.0 (55%) reached by the controls (P < .01). Both the GATA-1low and the normal mice respond to PHZ and EPO with similar (2- to 3-fold) increases in size and cellularity of the spleen (increases are limited mostly to cells, both progenitor and precursor, of the erythroid lineage). However, in spite of the similar relative cellular increases, the increases of all these cell populations are significantly higher, in absolute cell numbers, in the mutant than in the wild-type mice. In conclusion, the GATA-1low mutation increases the magnitude of the response to erythroid stimuli as a consequence of the expansion of the erythroid progenitor cells in their spleen.
Cell-surface trafficking and release of flt3 ligand from T lymphocytes is induced by common cytokine receptor γ-chain signaling and inhibited by cyclosporin A
Authors: Chklovskaia Elena , Nissen Catherine , Landmann Lukas , Rahner Christoph , Pfister Otmar , Wodnar-Filipowicz Aleksandra
Published: July 2002

The flt3 ligand (FL) is a growth and differentiation factor for primitive hematopoietic precursors, dendritic cells, and natural killer cells. Human T lymphocytes express FL constitutively, but the cytokine is retained intracellularly within the Golgi complex. FL is mobilized from the cytoplasmic stores and its serum levels are massively increased during the period of bone marrow aplasia after stem cell transplantation (SCT). Signals that trigger the release of FL by T cells remain unknown. This study shows that interleukin (IL)-2, IL-4, IL-7, and IL-15, acting through a common receptor γ chain (γc), but not cytokines interacting with other receptor families, are efficient inducers of cell surface expression of membrane-bound FL (mFL) and secretion of soluble FL (sFL) by human peripheral blood T lymphocytes. The γc-mediated signaling up-regulated FL in a T-cell receptor-independent manner. IL-2 and IL-7 stimulated both FL messenger RNA (mRNA) expression and translocation of FL protein to the cell surface. Cyclosporin A (CsA) inhibited γc-mediated trafficking of FL at the level of transition from the Golgi to the trans-Golgi network. Accordingly, serum levels of sFL and expression of mFL by T cells of CsA-treated recipients of stem cell allografts were reduced approximately 2-fold (P < .01) compared to patients receiving autologous grafts. The conclusion is that FL expression is controlled by γc receptor signaling and that CsA interferes with FL release by T cells. The link between γc-dependent T-cell activation and FL expression might be important for T-cell effector functions in graft acceptance and antitumor immunity after SCT.
The influence of INK4 proteins on growth and self-renewal kinetics of hematopoietic progenitor cells
Authors: Lewis John L. , Chinswangwatanakul Wimol , Zheng Bo , Marley Stephen B. , Nguyen Dao X. , Cross Nicholas C. P. , Banerji Lolita , Glassford Janet , Thomas N. Shaun B. , Goldman John M. , Lam Eric W.-F. , Gordon Myrtle Y.
Published: July 2002

This study investigated the influence of expression of proteins of the INK4 family, particularly p16, on the growth and self-renewal kinetics of hematopoietic cells. First, retrovirus-mediated gene transfer (RMGT) was used to restore p16INK4aexpression in the p16INK4a-deficient lymphoid and myeloid cell lines BV173 and K562, and it was confirmed that this inhibited their growth. Second, to sequester p16INK4a and related INK4 proteins, cyclin-dependent kinase 4 (CDK4) was retrovirally transduced into normal human CD34+ bone marrow cells and then cultured in myeloid colony-forming cell (CFC) assays. The growth of CDK4-transduced colonies was more rapid; the cell-doubling time was reduced; and, upon replating, the colonies produced greater yields of secondary colonies than mock-untransduced controls. Third, colony formation was compared by marrow cells fromp16INK4a−/− mice and wild-type mice. The results from p16INK4a−/−marrow were similar to those from CDK4-transduced human CFCs, in terms of growth rate and replating ability, and were partially reversed by RMGT ofp16INK4a. Lines of immature granulocytic cells were raised from 15 individual colonies grown from the marrow ofp16INK4a−/−mice. These had a high colony-forming ability (15%) and replating efficiency (96.7%). The p16INK4a−/−cell lines readily became growth factor–independent upon cytokine deprivation. Taken together, these results demonstrate that loss of INK4 proteins, in particular p16INK4a, increases the growth rate of myeloid colonies in vitro and, more importantly, confers an increased ability for clonal expansion on hematopoietic progenitor cells.
Increased frequencies of glutathione S-transferase(GSTM1 and GSTT1) gene deletions in Korean patients with acquired aplastic anemia
Authors: Lee Kyung A. , Kim Sun Hee , Woo Hee Yeon , Hong Young Joon , Cho Hyoun Chan
Published: July 2002

Patients with reduced ability to metabolize environmental carcinogens or toxins may be at risk of developing aplastic anemia. Glutathione S-transferase (GST) has been implicated in detoxifying mutagenic electrophilic compounds. This study asked whether the homozygous gene deletions of GSTM1 andGSTT1 affect the likelihood of developing aplastic anemia. The incidence of GSTM1 and GSTT1 gene deletions was significantly higher for aplastic anemia patients (odds ratio [OR]: 3.1, P = .01 and OR: 3.1,P = .004, respectively) than for healthy controls. Among the aplastic anemia patients, 17.5% (10:57) had chromosomal abnormalities at the time of diagnosis, and all aplastic anemia patients with chromosomal abnormalities showedGSTT1 gene deletions (P = .048). Individuals with GSTM1 and GSTT1 gene deletions may have greater susceptibility to aplastic anemia. It is possible that genetic instability or chromosomal damage due to abnormal detoxification of environmental toxins might have worked as an important pathophysiologic mechanism of aplastic anemia for patients with GSTT1 gene deletions.
Homologous recombination deficiency score is an independent prognostic factor in esophageal squamous cell carcinoma
Authors: Wang Yulu , Ding Bowen , Tao Yunlan , Huang Lingli , Zhu Qian , Gao Chengying , Feng Mingli , Han Yuchen
Published: October 2024

Homologous recombination deficiency (HRD) represents an impairment in the homologous recombination repair (HRR) pathway, crucial for repairing DNA double‐strand breaks and contributing to genomic instability in cancer. The HRD score may be a more reliable biomarker than HRR‐related gene mutations for identifying patients sensitive to poly(ADP‐ribose) polymerase inhibitors. Despite its relevance in various cancers, the HRD score remains underexplored in esophageal squamous cell carcinoma (ESCC). We retrospectively analyzed HRD scores in 96 ESCC patients, examining correlations with clinical characteristics and survival outcomes, and validated our findings using the TCGA dataset. Genomic sequencing utilized a custom superHRD next‐generation sequencing panel, and HRD scores were calculated from 54,000 single‐nucleotide polymorphisms using Kruskal–Wallis rank‐sum tests and two cut‐off points for analysis. Higher HRD scores correlated with advanced tumor stages, recurrence, and mutations in TP53 and ABCB1, while APC mutations were linked to lower HRD scores. Patients with high HRD scores had significantly shorter disease‐free survival (p = 0.013) and a trend toward shorter overall survival (OS) (p = 0.005), particularly those not receiving adjuvant therapy. Conversely, HRD‐high patients undergoing adjuvant therapy showed a trend toward longer OS (p = 0.015). Multivariate analysis identified HRD as an independent prognostic factor (hazard ratio = 2.814 for recurrence, p = 0.015). Validation with the TCGA dataset supported these findings. This study highlights the associations between HRD scores, clinical characteristics, and genomic mutations in ESCC, suggesting HRD as a potential prognostic biomarker. HRD assessment may aid in patient stratification and personalized treatment strategies, warranting further investigation to validate the therapeutic implications of HRD scores in ESCC.
Underwater Structurally‐Colored Adhesives for Visualized Adhesion Monitoring in Aqueous Media
Authors: Yu Ying , Lyu Quanqian , Zhang Xiujuan , Li Miaomiao , Zhao Meiru , Hu Zhen , Zhang Lianbin , Zhu Jintao
Published: October 2024

Assessment of the local strain/stress changes of adhesives is highly desirable for their service to avoid premature failure. However, monitoring local strain/stress variations in adhesives in practical settings remains challenging, especially in aqueous media. Here, an underwater structurally‐colored adhesive for visualized local strain/stress monitoring in aqueous media is reported. The structurally‐colored adhesive is obtained by shearing composites of poly(butyl acrylate‐co‐acrylic acid) copolymer and carboxylated polystyrene colloidal particles. The resultant structurally‐colored adhesive exhibits underwater adhesive strength (i.e., 238 kPa for stainless steel substrates) to various substrates (e.g., metals and plastics) thanks to hydrophobic segments and carboxyl groups. Notably, they can shift color in response to external force, enabling real‐time visual monitoring of localized strain/stress changes. As a proof of concept, the structurally‐colored adhesive can be used to seal a leaking hole on a bottle or tube, and it can precisely visualize the localized pressure distribution, providing critical information on the adhesion performance and the local pressure. These distinctive properties make the structurally‐colored adhesive suitable for application in wet environments as a real‐time visual pressure tracking device.
Ultra‐High Secure Holographically Steganographic Array with Spatiotemporal Dual‐Encryption Keys
Authors: Zhu Zelin , Qi Xiuping , Zhang Zhihao , Dou Xuanyu , Jiang Xinxin , Liu Yutong , Fu Shencheng , Zhang Xintong , Liu Yichun
Published: October 2024

Independently‐manipulated optical encryption has attracted great attention due to its high security and multiple application scenarios. Although photochromic molecules have become preferred holographic display units, the integration of dynamic modulation both in hologram and fluorescence for orthogonal encryption is still challenged. Herein, a latticed holographically steganographic array is constructed by incorporating a plasticizer (tri‐o‐cresyl phosphate, TOCP) into spirooxazine (SO) based polymers, thereby modulating the isomerization rate and the UV‐fluorescence kinetics between SO and merocyanine (MC). The period to reach fluorescence saturated value for each information bit in the latticed device can be widely modulated between 60 and 1700 s. Based on the property, only through ultraviolet stimulation can array information gradually be converted from spatial lattice coordinates to holographic display time. Then, a hidden 3D image can be determined from rapidly updatable reconstructed hologram video with refresh rate 1.125 Hz by the above spatiotemporal dual‐encryption keys. This work provides a bright path for the ultra‐high safety steganography and adaptive stereoscopic imaging.
Selective Twin NIR‐IIb Ratiometric Luminescence Nanoprobes Enable the Accurate Visualization of MPO‐Mediated Oxidative Stress in Acute Liver Injury
Authors: Liu Xiao , Li Wei , Shen Yang , He Linhui , Lai Huanhua , Chen Yushi , Chen LanLan , Zhang Xiao‐Bing , Yuan Lin
Published: October 2024

Oxidative stress, orchestrated by myeloperoxidase (MPO), plays crucial roles in the progression of many diseases. Nonetheless, the role of MPO‐mediated oxidative stress in distinct factor‐induced acute liver injuries (ALI) is still up for dispute, mainly due to the lack of probes for in vivo monitoring of MPO releases. Here, a highly selective MPO probe (CSQ) based on the epoxidation biochemical reaction within the MPO‐H2O2‐Cl− system is screened to construct dual near infrared‐IIb (NIR‐IIb) ratiometric (F1550Em, 808Ex/F1550Em, 980Ex) luminescence nanoprobes by integrating CSQ onto down conversion nanoparticles (DCNPs) with and without liver‐targeting moiety (twin NIR‐IIb nanoprobes). Liver‐targeting probes are employed to monitor MPO release, whereas non‐liver‐targeting probes are utilized to assess MPO activity across all cell types. Using twin NIR‐IIb nanoprobes, the MPO‐mediated oxidative stress progressively increased are observed in carbon tetrachloride (CCl4)‐induced ALI over 12 h. In contrast, the MPO‐mediated oxidative stress in acetaminophen (APAP)‐induced ALI initially increased, peaked within 3 h, and then rapidly weakened to normal levels within 12 h. Importantly, the differential release of MPO from neutrophils/Kupfer cells to extracellular fluids in the two types of ALI is revealed. This work reveals significant differences in MPO distribution and the role of MPO‐mediated oxidative stress in CCl4 and APAP‐induced ALI.
Recent Advances in Enzyme‐based Biofuel Cells Using Glucose Fuel: Achieving High Power Output and Enhanced Operational Stability
Authors: Pak Junha , Chang Woojae , Kwon Cheong Hoon , Cho Jinhan
Published: October 2024

An enzyme‐based biofuel cell (EBFC) is widely regarded as one of the most efficient power sources for bio‐friendly and implantable medical devices, capable of converting electrochemical reactions into electrical currents under physiological conditions. However, despite its potential, the practical and commercial use of EBFCs is limited by their low power output and operational instability. Therefore, significant research efforts have focused on increasing power output and stability by improving electron transfer between enzymes and host electrodes and developing efficient enzyme immobilization techniques. However, most EBFCs produced by current methods still deliver unsatisfactory performance. A promising approach to address these challenges is the use of conductive linkers that promote favorable interfacial interactions between adjacent enzymes and between enzymes and host electrodes. These linkers can facilitate electron transfer and ensure robust enzyme immobilization. In addition, designing the host electrode with a 3D structure and a large surface area can further improve the areal energy performance. This perspective reviews the working principles, types, and electron transfer mechanisms of EBFC electrodes and explores how conductive linkers and 3D host electrodes can enhance the performance of EBFC electrodes. Finally, recent advances in integrating EBFCs into biomedical devices are described.
Wearable Multifunctional Hydrogel for Oral Microenvironment Visualized Sensing Coupled with Sonodynamic Bacterial Elimination and Tooth Whitening
Authors: Dai Chaobo , Shi Zhenghan , Xu Yi , Su Lingkai , Li Xin , Deng Peixue , Wen Hao , Wang Jiahao , Ye Qing , Han Ray P.S. , Liu Qingjun
Published: October 2024

Bacterial‐driven dental caries and tooth discoloration are growing concerns as the most common oral health problems. Current diagnostic methods and treatment strategies hardly allow simultaneous early detection and non‐invasive treatment of these oral diseases. Herein, a wearable multifunctional double network hydrogel combined with polyaniline and barium titanate (PANI@BTO) nanoparticles is developed for oral microenvironment visualized sensing and sonodynamic therapy. Due to the colorimetric properties of polyaniline, the hydrogel displays a highly sensitive and selective response for visualized sensing of oral acidic microenvironment. Meanwhile, the barium titanate in the hydrogel efficiently generates reactive oxygen species (ROS) under ultrasound irradiation, realizing non‐invasive treatment in the oral cavity. Through bacterial elimination experiments and tooth whitening studies, the hydrogel can achieve the dual effect of effectively inhibiting the growth of cariogenic bacteria and degrading tooth surface pigments. Owing to the visualized sensing of the oral acidic microenvironment and efficient sonodynamic therapy function, the proposed hydrogel system offers a solution for the prevention of caries and tooth whitening, which is promising in developing the biomedical system targeting the simultaneous sensing and therapy for oral diseases.