bluuebunny/crossref_metadata_2025 huggingface dataset:
GraphMDP: A NEW DECOMPOSITION TOOL FOR SOLVING MARKOV DECISION PROCESSES
Authors: LAROCHE PIERRE
Published: July 2002

In this paper, we present a new tool for solving weakly-coupled Markov Decision Processes using decomposition techniques. Using a predefined partition of the MDP, a directed graph is built to decompose the global MDP into small local MDPs which are independently solved. An approximate solution for the global MDP is obtained by combining local solutions. Our approach has been tested on a mobile robotics application. It allows near-optimal solutions to be obtained in significantly reduced time. We also present preliminary results concerning a parallel implantation of our tool.
BIOLOGICAL DISTANCES ON DNA KNOTS AND LINKS: Applications to XER recombination
Authors: DARCY ISABEL K.
Published: July 2002

The mathematics of tangles has been very useful in studying recombinases which act processively and which require DNA to be in a certain configuration in order for the enzyme to act. Electron micrographs of the enzyme-DNA complex show the enzyme as a blob with DNA looping out of it. The configuration of the DNA within the blob cannot be determined form the electron micrographs. However, mathematics can in some cases determine the configuration of the DNA within the enzyme blob as well as the enzyme action.

In this paper, several theorems used to analyze recombinase experiments are summarized. In particular Xer recombinase, an enzyme which does not act processively is analyzed. Unfortunately, for enzymes which do not act processively, infinitely many possibilities exist. Several experiments are proposed to reduce this number and to emphasize both the usefulness and limitations of tangle analysis. Although the local action cannot be mathematically determined without more biological assumptions, it is possible to determine the topology of the synaptic complex through additional biolgical experiments.
VASSILIEV KNOT INVARIANTS OF ORDER 6
Authors: KANENOBU TAIZO
Published: July 2002

We give a basis for the space of the Vassiliev knot invariants of order 6, which implies a sixth order Vassiliev knot invariant is determined by its HOMFLY and Kauffman polynomials. Furthermore, we show that there is a seventh order invariant which cannot be obtained from these polynomials of a knot.
AN APPROXIMATE MODEL OF THE SPACETIME FOAM
Authors: DZHUNUSHALIEV V.
Published: July 2002

An approximate model of the spacetime foam is offered in which a quantum handle (wormhole) is a 5D wormhole-like solution. Neglecting the linear sizes of the wormhole throat we can introduce a spinor field for an approximate and effective description of the foam. The definition of the spinor field can be made by a dynamic and nondynamic ways. In the first case some field equations are used and the second case leads to superspace. It is shown that the spacetime with the foam is similar to a dielectric with dipoles and supergravity theories with a nonminimal interaction between spinor and electromagnetic fields can be considered as an effective model for the spacetime foam.
SPIN-ROTATION COUPLING EFFECTS ON THE STRUCTURE FORMATION IN GÖDEL UNIVERSE AND COBE DATA
Authors: DE ANDRADE L. C. GARCIA
Published: July 2002

A rotating universe represented by the Gödel metric in spacetimes with Cartan torsion is investigated. The spin–torsion coupling is shown to contribute to the structure formation in an apppreciable way only at the early stages of the universe. To demonstrate these conjectures, we have made use of a spinning fluid model in Einstein–Cartan gravity. We also show that autoparallel equation in Riemann–Cartan spacetime leads to the evolution equation of the cosmological perturbation where the spin-rotation coupling contributes to the growth of inhomogeneities through a constant term. From this idea, one is able to estimate that torsion in the Planck era is around 1015 s -1 where COBE constraint on temperature fluctuations is used in this computation. A spin density of the universe of 1053 g · cm -1 s -1 is also obtained in our framework.
ASYMPTOTIC BEHAVIOUR OF AN OPERATOR EXPONENTIAL RELATED TO BRANCHING RANDOM WALK MODELS OF DNA REPEATS
Authors: BOBROWSKI ADAM , KIMMEL MAREK
Published: July 2002

We study the asymptotic behaviour of an infinite system of differential equations describing the expectations in a branching random walk. The original stochastic formulation was employed to describe the process of evolution of reversible drug resistance in cancer cells. The problem is formulated as an operator exponential function in the space of absolutely summable sequences. Conditions are found for the asymptotic decay of the operator exponential function, using methods of the spectral theory of linear operators. A discussion is provided relating mathematical results to the behaviour of models of gene amplification and evolution of DNA repeats.
OPTIMAL INSPECTION AND REPLACEMENT MODELS FOR SYSTEMS WITH INCREASING MINIMAL REPAIR COST
Authors: CHAUDHURI DIPAK , MOHAMMED OTHMAN
Published: July 2002

Production systems are generally subjected to failures, which are not self-announcing. These failures may not bring the system to a complete halt but may cause its malfunction, which would affect the quality of output. Inspections at intervals are required to detect such failures. After a failure, the system would continue to produce degraded output unless corrective action (minimal repair) is taken after detecting the failure during inspection. These minimal repairs do not bring the system to "as good as new" condition, but restore its condition to the level prior to the failure. A replacement/overhaul of the system after operation for a long time will make it "as good as new." The paper presents optimal inspection models for such a production system. The system is replaced or overhauled at predetermined times, marking the end of a cycle, while inspections are periodically done within a cycle. An entire output during an interval is scrapped, if inspection reveals a failure during the interval. Dynamic programming formulation has been used to optimize expected profit per cycle. The model is suitable when prior sales commitments exist and failure of the system is not self-announcing.
A KINETIC MODEL FOR THE REMOVAL OF SULFUR FROM POLYCRYSTALLINE TITANIUM SURFACES EXPOSED TO OXYGEN
Authors: REIBEL R. , SCHNEIDER S. , CRUGUEL H. , LAPEYRE J. , SMITH R. J.
Published: July 2002

Recent studies using Auger Electron Spectroscopy (AES) on polycrystalline titanium surfaces led to the discovery of a temperature-dependent phenomenon for the removal of sulfur using oxygen exposures. It was seen that at temperatures greater than 200°C and pressures lower than 10-7 Torr O 2 the rate of sulfur removal from the surface was decreased significantly. The decrease in this rate of sulfur removal can be linked to several factors, including the temperature-enhanced diffusion of sulfur to the surface and the temperature-enhanced diffusion of oxygen into the bulk. By varying the pressure of oxygen and the temperature of the substrate and by monitoring the surface with AES we were able to identify the significant factors. A kinetic model for the two surface species is discussed and fit to the experimental results. This kinetic model includes physical parameters for such things as the activation energy for the sulfur diffusion to the surface as well as sticking coefficients for oxygen on the surface. Through this model the relevant factors for the decrease in the rate of sulfur removal are examined.
A MODEL OF STOCK MARKET BUBBLE UNDER UNCERTAIN FUNDAMENTALS
Authors: DEAN J. , MILOVANOV T.
Published: July 2002

A model for a stock market bubble is based upon the assumption that market agents incorporate trend and deviation of the actual price from the fundamental value into their expectations. Possible price dynamics are analyzed, and necessary conditions for large price deviations are obtained.
INCREASING SPOT RATES OF INTEREST: STRUCTURE OF THE PRICE OF A DEFAULT FREE DISCOUNT BOND
Authors: CRUZ RAMBAUD SALVADOR , DEL CARMEN VALLS MARTÍNEZ MARÍA
Published: July 2002

This paper aims to establish a set of necessary and sufficient conditions that the expression of a default free bond must verify in a situation in which spot rates of interest increase. In this case, if the agent divides the period of his investment, that is, if he disinvests and, immediately, re-invests his capital in different issues of bonds, can obtain an advantage in the final amount. In order to do this, necessary conditions include an approximation of the forward interest rate, that is to say the logarithmic density, its limits to +∞ and -∞ and the second generalized derivative of the bond price. Sufficient conditions involve an auxiliary function using these limits and, finally, necessary and sufficient conditions are related with the logarithm of the bond price.
A Causality Study of the Relations between Wage and Employment in Specific OECD Countries
Authors: Chew Soon Beng , Teo Chadwick
Published: July 2002

We analyze the dynamic relationship between employment and wages for a number of OECD countries between the years 1969 to 1998. We propose factors that determine the type of industrial regime in a country. These include government policies, the goals of the labor unions and employers and institutional structures and practices. Looking into the future, with the advent of globalization, there should be a convergence toward employment-driven industrial relations regime as countries strive to keep labor cost competitive to ensure survival in international markets.
DQEM VIBRATION ANALYSES OF NONPRISMATIC BEAMS RESTING ON ELASTIC FOUNDATIONS
Authors: CHEN CHANG-NEW
Published: July 2002

The development of differential quadrature element method (DQEM) free vibration analysis model of nonprismatic Bernoulli–Euler beams resting on Winkler elastic foundations was carried out. The DQEM uses the extended differential quadrature (EDQ) to discretize the differential eigenvalue equation defined on each element, the transition conditions defined on the inter-element boundary of two adjacent elements and the boundary conditions of the beam. Numerical results solved by the developed numerical algorithm are presented. They prove that the DQEM is efficient. The developed numerical algorithm can be used to analyze the related pressure vessel and piping structures.
NOISE–INDUCED PHASE TRANSITIONS BY NONLINEAR INSTABILITY MECHANISM
Authors: CARRILLO O. , IBAÑES M. , SANCHO J. M.
Published: July 2002

First and second-order nonequilibrium phase transitions induced by an external nonlinear multiplicative noise are studied. A theoretical approach gives that the physical mechanism responsible for these transitions is a nonlinear instability of the homogeneous phase. Mean–field analysis and numerical simulations confirm the theoretical prediction.
HYBRID INSTANCE-BASED SYSTEM FOR PREDICTING OCEAN TEMPERATURES
Authors: CORCHADO JUAN M. , LEES B. , AIKEN J.
Published: July 2002

An instance-based problem solving model is presented in which the aim is to forecast, in real time, the physical parameter values of a complex and dynamic environment: the ocean. The situations in which the rules that determine a system are unknown, the prediction of the parameter values that determine the characteristic behaviour of the system can be a problematic task. In such a situation it has been found that an instance-based reasoning system can provide a more effective means of performing such predictions than other connectionist or symbolic techniques. The instance-based reasoning system incorporates a radial basis function artificial neural network for the instance adaptation. The results obtained from experiments, in which the system operated in real time in the oceanographic environment, are presented.
Response times in level-structured systems
Authors: Harter Paul K.
Published: July 2002

Real-time programs are among the most critical programs in use today, yet they are also among the worst understood and the most difficult to verify. Validation of real-time systems is nonetheless extremely important in view of the high costs associated with failure in typical application areas. We present here a method for deriving response-time properties in complex systems with a level structure based on priority. The method involves a level-by-level examination of the system, in which information distilled from each successive level is used to adjust the results for later levels. The results obtained at each level of the system are not affected by later analyses, which obviates having to consider a complex system as a whole.
Transactional client-server cache consistency
Authors: Franklin Michael J. , Carey Michael J. , Livny Miron
Published: July 2002

Client-server database systems based on a data shipping model can exploit client memory resources by caching copies of data items across transaction boundaries. Caching reduces the need to obtain data from servers or other sites on the network. In order to ensure that such caching does not result in the violation of transaction semantics, a transactional cache consistency maintenance algorithm is required. Many such algorithms have been proposed in the literature and, as all provide the same functionality, performance is a primary concern in choosing among them. In this article we present a taxonomy that describes the design space for transactional cache consistency maintenance algorithms and show how proposed algorithms relate to one another. We then investigate the performance of six of these algorithms, and use these results to examine the tradeoffs inherent in the design choices identified in the taxonomy. The results show that the interactions among dimensions of the design space impact performance in many ways, and that classifications of algorithms as simply “pessimistic” or “optimistic” do not accurately characterize the similarities and differences among the many possible cache consistency algorithms.
Three principles of representation for semantic networks
Authors: Griffith Robert L.
Published: July 2002

Semantic networks are so intuitive and easy to use that they are often employed without much thought as to the phenomenon of semantic nets themselves. Since they are becoming more and more a tool of artificial intelligence and now database technology, it is appropriate to focus on the principles of semantic nets. Such focus finds a harmonious and consistent base which can increase the semantic quality and usefulness of such nets. Three rules of representation are presented which achieve greater conceptual simplicity for users, simplifications in semantic net implementations and maintenance, and greater consistency across semantic net applications. These rules, applied to elements of the net itself, reveal how fundamental structures should be organized, and show that the common labeled-edge semantic net can be derived from a more primitive structure involving only nodes and membership relationships (and special nodes which represent names). Also, the correlation between binary and
n
-ary relations is presented.
Time-shared Systems
Authors: Kleinrock Leonard
Published: July 2002

Time-shared computer (or processing) facilities are treated as stochastic queueing systems under priority service disciplines, and the performance measure of these systems is taken to be the average time spent in the system. Models are analyzed in which time-shared computer usage is obtained by giving each request a fixed quantum
Q
of time on the processor, after which the request is placed at the end of a queue of other requests; the queue of requests is constantly cycled, giving each user
Q
seconds on the machine per cycle. The case for which
Q
→ 0 (a processor-shared model) is then analyzed using methods from queueing theory. A general time-shared facility is then considered in which
priority groups
are introduced. Specifically, the
p
th priority group is given

g
p
Q

seconds in the processor each time around. Letting
Q
→ 0 gives results for the priority processor-shared system. These disciplines are compared with the first-come-first-served disciplines. The systems considered provide the two basic features desired in any time-shared system, namely, rapid service for short jobs and the virtual appearance of a (fractional capacity) processor available on a full-time basis. No charge is made for swap time, thus providing results for “ideal” systems. The results hold only for Poisson arrivals and geometric (or exponential) service time distributions.
Hashing Schemes for Extendible Arrays
Authors: Rosenberg Arnold L. , Stockmeyer Larry J.
Published: July 2002

The use of hashing schemes for storing extendible arrays is investigated. It is shown that extendible hashing schemes whose worst-case access behavior is close to optimal must utilize storage inefficiently; conversely hashing schemes that utilize storage too conservatively are inevitably poor in expected access time. If requirements for the utilization of storage are relaxed slightly, then one can find rather efficient extendible hashing schemes. Specifically, for any dimensionality of arrays, one can find extendible hashing schemes which at once utilize storage well (fewer than 2
p
storage locations need be set aside for storing arrays having
p
or fewer positions) and enjoy good access characteristics (expected access time is
O
(1), and worst-case access time is
O
(log log
p
) for
p
- or fewer-position arrays). Moreover, at the cost of only a modest additive increase in access time, storage demands can be decreased to (1 + δ)
p
locations for arbitrary δ > 0.
A cost model for query processing in high dimensional data spaces
Authors: Böhm Christian
Published: July 2002

During the last decade, multimedia databases have become increasingly important in many application areas such as medicine, CAD, geography, and molecular biology. An important research topic in multimedia databases is similarity search in large data sets. Most current approaches that address similarity search use the feature approach, which transforms important properties of the stored objects into points of a high-dimensional space (feature vectors). Thus, similarity search is transformed into a neighborhood search in feature space. Multidimensional index structures are usually applied when managing feature vectors. Query processing can be improved substantially with optimization techniques such as blocksize optimization, data space quantization, and dimension reduction. To determine optimal parameters, an accurate estimate of index-based query processing performance is crucial. In this paper we develop a cost model for index structures for point databases such as the R*-tree and the X-tree. It provides accurate estimates of the number of data page accesses for range queries and nearest-neighbor queries under a Euclidean metric and a maximum metric and a maximum metric. The problems specific to high-dimensional data spaces, called boundary effects, are considered. The concept of the fractal dimension is used to take the effects of correlated data into account.
A mathematical programming updating method using modified Givens transformations and applied to LP problems
Authors: Hanson Richard J. , Wisniewski John A.
Published: July 2002

An efficient and numerically stable method is presented for the problem of updating an orthogonal decomposition of a matrix of column (or row) vectors. The fundamental idea is to add a column (or row) analogous to adding an additional row of data in a linear least squares problem. A column (or row) is dropped by a formal scaling with the imaginary unit, √-1, followed by least squares addition of the column (or row). The elimination process for the procedure is successive application of the Givens transformation in modified (more efficient) form. These ideas are illustrated with an implementation of the revised simplex method. The algorithm is a general purpose one that does not account for any particular structure or sparsity in the equations. Some suggested computational tests for determining signs of various controlling parameters in the revised simplex algorithm are mentioned. A simple means of constructing test cases and some sample computing times are presented.
Computer generation of gamma random variables
Authors: Tadikamalla Pandu R.
Published: July 2002

A new method for generating random variables from the gamma distribution with nonintegral shape parameter α is proposed. This method is similar to two other methods recently given by Wallace and Fishman. It is compared with Fishman's and Ahrens and Dieter's methods. The core storage requirements and programming effort for this method are similar to those of Fishman's method. The proposed method is the same as Fishman's method for 1 ≤ α < 2 and is faster than Fishman's method for 3 ≤ α ≤ 19. Also, the proposed method is much simpler than Ahrens and Dieter's method and is faster for α ≤ 8.
Probabilistic agent programs
Authors: Dix Jürgen , Nanni Mirco , Subrahmanian V. S.
Published: July 2002

Agents are small programs that autonomously take actions based on changes in their environment or “state”. Over the last few years, there has been an increasing number of efforts to build agents that can interact and/or collaborate with other agents. In one of these efforts Eiter et al. [1999] have shown how agents may be built on top of legacy code. However, their framework assumes that agent states are completely determined, and there is no uncertainty in an agent's state. Thus, their framework allows an agent developer to specify how his agents will react when the agent is 100% sure about what is true/false in the world state. In this paper, we propose the concept of a
probabilistic agent program
and show how, given an arbitrary program written in any imperative language, we may build a declarative “probabilistic” agent program on top of it which supports decision making in the presence of uncertainty. We provide two alternative semantics for probabilitic programs. We provide sound and complete algorithms to compute the semantics of
positive
agent programs.
Methods of evaluating polynomial approximations in function evaluation routines
Authors: Fike C. T.
Published: July 2002

The method of nested multiplication is commonly used in function evaluation routines to evaluate approximation polynomials. New polynomial evaluation methods have been developed in recent years which require fewer multiplications than nested multiplication and may therefore be preferable for use in function evaluation routines. Although some of these methods do not appear to be practically useful because of rounding-error difficulties, several methods of evaluating low-degree polynomials have been found to be satisfactory. Three such methods are described and illustrated.
ARPA
Authors: Titus James P.
Published: July 2002

The Advanced Research Projects Agency has probably done more to lift computer science from other disciplines and to put it on its own feet than any organization inside or outside of government. Even today, when support of computing is spread throughout the government, ARPA is practically alone in its belief that computing deserves to be a separate discipline. Ironically, the computer profession knows little about this friendly benefactor.
Modeling the storage architectures of commercial database systems
Authors: Batory D. S.
Published: July 2002

Modeling the storage structures of a DBMS is a prerequisite to understanding and optimizing database performance. Previously, such modeling was very difficult because the fundamental role of conceptual-to-internal mappings in DBMS implementations went unrecognized.

In this paper we present a model of physical databases, called the transformation model, that makes conceptual-to-internal mappings explicit. By exposing such mappings, we show that it is possible to model the storage architectures (i.e., the storage structures and mappings) of many commercial DBMSs in a precise, systematic, and comprehendible way. Models of the INQUIRE, ADABAS, and SYSTEM 2000 storage architectures are presented as examples of the model's utility.

We believe the transformation model helps bridge the gap between physical database theory and practice. It also reveals the possibility of a technology to automate the development of physical database software.
On estimating the cardinality of the projection of a database relation
Authors: Ahad Rafiul , Bapa K. V. , McLeod Dennis
Published: July 2002

We present an analytical formula for estimating the cardinality of the projection on certain attributes of a subset of a relation in a relational database. This formula takes into account a priori knowledge of the semantics of the real-world objects and relationships that the database is intended to represent. Experimental testing of the formula shows that it has an acceptably low percentage error, and that its worst-case error is smaller than the best-known formula. Furthermore, the formula presented here has the advantage that it does not require a scan of the relation.
Chromatin Insulators and Boundaries: Effects on Transcription and Nuclear Organization
Authors: Gerasimova Tatiana I. , Corces Victor G.
Published: July 2002

▪ Abstract  Chromatin boundaries and insulators are transcriptional regulatory elements that modulate interactions between enhancers and promoters and protect genes from silencing effects by the adjacent chromatin. Originally discovered in Drosophila, insulators have now been found in a variety of organisms, ranging from yeast to humans. They have been found interspersed with regulatory sequences in complex genes and at the boundaries between active and inactive chromatin. Insulators might modulate transcription by organizing the chromatin fiber within the nucleus through the establishment of higher-order domains of chromatin structure.
BONE MARROW TRANSPLANTATION IN THALASSEMIA
Authors: Giardini, M.D Claudio , Galimberti, M.D Mariella , Lucarelli, M.D Guido
Published: July 2002

▪ Abstract  Early trials of allogeneic bone marrow transplantation (BMT) for homozygous β-thalassemia and the analyses of results of transplantation in patients less than 16 years old have allowed us to identify three classes of risk based on the following criteria: (a) hepatomegaly, (b) presence of liver fibrosis at histological examination, and (c) quality of chelation treatment given before transplant. Patients with none of these adverse criteria were assigned to Class 1; patients with either one or two adverse criteria comprised Class 2; and patients for whom all three criteria were adverse constituted Class 3. Most patients older than 16 years have disease characteristics that place them in Class 3, with very few falling into Class 2. All patients with a histocompatibility leukocyte antigen (HLA)—identical donor are actually assigned to one of two conditioning regimens on the basis of the class they belong to at the time of BMT and independently of age. For Class 1, Class 2, and Class 3 patients, the probabilities of survival and event-free survival are 95 and 90%, 86 and 82%, and 87 and 63%, respectively. For those patients older than 16 years at the time of transplant, the probabilities of survival and of event-free survival are 78 and 74%, respectively. Allogeneic BMT is currently the only rational therapeutic modality for the eradication of β-thalassemia.
GAS-PHASE AND HETEROGENEOUS CHEMICAL KINETICS OF THE TROPOSPHERE AND STRATOSPHERE
Authors: Molina Mario J. , Molina Luisa T. , Kolb Charles E.
Published: July 2002

▪ Abstract  This review involves chemical kinetics of atmospheric reactions, with emphasis on gas phase and heterogeneous processes related to the following topics: (a) in the troposphere, chemistry of CFC/Halon replacement compounds and chemistry of sulfur species and (b) in the stratosphere, chemistry of fluorine, bromine, and iodine species and of heterogeneous processes occurring on sulfuric acid aerosols. The results of laboratory measurements of rate parameters are summarized, and current views are presented on the physical chemistry foundation underlying the interpretation of these kinetics parameters.
THE FAST PROTEIN FOLDING PROBLEM
Authors: Gruebele M.
Published: July 2002

▪ Abstract  During protein folding, many of the events leading to secondary and tertiary structure occur in milliseconds or faster. Modern nuclear magnetic resonance and laser detection techniques, coupled with fast initiation of the folding reaction, are probing these events in great detail. Theory, ranging from analytical models to molecular dynamics calculations, is beginning to match up with experiment. As a result, timescales, from such elementary steps as the addition of a residue to a helix to strange kinetics of collapsing protein backbones, can now be measured and interpreted.
HELPER-DEPENDENT VECTOR TRANSMISSION OF PLANT VIRUSES
Authors: Pirone Thomas P. , Blanc Stéphane
Published: July 2002

▪ Abstract  A variety of noncirculatively transmitted viruses have evolved a vector transmission strategy that involves, in addition to virions, virus-encoded proteins that are not constituents of virions. These “helpers” and the genes encoding them have been characterized for viruses in the genera Potyvirus and Caulimovirus. Several lines of evidence support the hypothesis that these helpers act by mediating retention of virions in regions of the vector's alimentary tract from which they subsequently can be egested to initiate an infection. The possible advantage this convergently evolved strategy could confer to noncirculatively transmitted virus quasispecies is discussed.
World Wide Simultaneous Dance: Dancing the Connection between “Cyberplace” and the Global Landscape
Authors: Knott Laura
Published: July 2002

The author describes World Wide Simultaneous Dance, a project combining live perfor-mances and digital connectivity, designed to give visual hints of an image that cannot yet be visual-ized: people dancing at the same time around the world, in varying conditions of light and at varying local times, the planet seeming for a moment to stand still as the per-formers locked on to each others' signals. Technical considerations and performances are described. The author also discusses the ge-nealogy of this work and future work suggested by World Wide Si-multaneous Dance.
What Are Humans For?: Art in the Age of Post-Human Development
Authors: Arike Ando
Published: July 2002

If the development of mass media utterly revolutionized the situation of art in the 20th century, current research into the technological reconfiguration and replacement of the human organism promises an even more radical disruption of art's cultural status. As engineers contemplate the creation of artificial life, artistic creation again finds its traditional values and procedures called into question. How will artists respond to the challenges posed by cyborg culture?
Blindsight after Optic Nerve Injury Indicates Functionality of Spared Fibers
Authors: Wüst Stefan , Kasten Erich , Sabel Bernhard A.
Published: July 2002

Some patients with lesions in the geniculostriate pathway (GSP) can respond to visual stimuli in the blind field without conscious acknowledgement. The substrate for this “blind-sight” is controversial: whether it is the uninjured extrastriate pathway (EXP), which bypasses the lesion site, or residual fibers within damaged visual cortex (“islands of vision”). Using stimulus detection, localization, and spatial summation tasks, we have found blindsight in patients with damage both in the optic nerve (ON) and EXP. The prevalence and functional characteristics of their blindsight are indistinguishable from that in patients with GSP lesions, so blindsight does not require a completely intact EXP. The present findings support the view that a few surviving ON axons within an area of primary damage are sufficient to mediate blindsight: Several combinations of partially intact pathways can transmit information to the extrastriate cortex and the sum of activation of all visual fibers surviving the injury determines if and to what extent blindsight occurs.
TRANSITORISCHE AMBIGUITÄT IN THRENI III
Authors: Weber Beat
Published: July 2002

Thr. iii ist ein vierteiliges Poem in diptychischer Gestalt, wobei die Teile 1-21 und 34-54 einerseits sowie 22-33 und 55-66 andererseits zueinander parallel, aber untereinander kontrastiv stehen. Bei den Übergängen 21->22, 33->34 und 54->55 finden sich Scharnier-Bereiche, die den Umschlag von Klage zu Hoffnung bzw. vice versa bearbeiten. Dies geschieht durch unterschiedliche Muster transitorischer Ambiguität. Im ersten Fall wird diese durch angelegte Mehrdeutigkeiten im Bereich der Verbformen realisiert, im zweiten Fall durch eine Doppelgleisigkeit der Modi "Aussage" und "(rhetorische) Frage" und im dritten Fall durch das formkritische Nebeneinander von "Klage" und "Danklied". Diese Mehrdeutigkeitsformen der Poesie mit ihrer Ermöglichung der "Gleichzeitigkeit" von Aussagen werden theologisch in Dienst genommen, um die grosse Spannung auszudrücken, die darin besteht, dass JHWH, von dem Rettung erhofft wird, der gleiche ist, der als "Feind" die unermessliche Not verursacht hat.
ISRAELS PSALMEN IN ÄGYPTEN? PAPYRUS AMHERST 63 UND DIE PSALMEN XX UND LXXV
Authors: Rösel Martin
Published: July 2002

Der in Ägypten gefundene Papyrus Amherst 63 enthält mehrere Einzeltexte unterschiedlicher Gattungen und Herkunft. Da sie zwar in aramäischer Sprache, aber in demotischer Schrift geschrieben wurden, gibt es bis heute keine allgemein akzeptierte Transkription oder Übersetzung. Der Aufsatz untersucht die in den Kolumnen 12 und 13 erhaltenen Texte, die aufgrund des auffälligen Gottesnamengebrauchs und inhaltlicher Parallelen aus israelitischen Traditionen stammen müssen. Über die bekannte Parallele von Kol. 12,11ff. zu Ps. xx hinaus wird argumentiert, daß sich in Kol. 13,5-9 Ps. lxxv 8-10 spiegelt. Auch zu Kol. 13,11ff. lassen sich biblische Parallelen (Ex. xv; Ps. xix) finden. Die Texte gehen offenbar auf gemeinsame Vorstufen zurück, die am Reichsheiligtum in Bethel tradiert wurden.
Moving reactive interfaces and fractal carbonate replacement patterns in serpentinites: evidence from the southern Iberia Abyssal Plain
Authors: Hopkinson L. J. , Dee S. , Boulter C. A.
Published: July 2002

Serpentinized ultramafic rocks recovered from beneath the southern Iberia Abyssal Plain (Ocean Drilling Programme Leg 173) provide the first record of fractal carbonate replacement patterns in a serpentinite. The patterns are expressed as microscopic branching aggregates (clusters) of aragonite disseminated throughout the serpentinites. Aragonite growth was the final mineralization event. The aragonite diminishes rapidly in quantity from an essential to a trace component of the serpentinite over a distance of ∼40 m from a normal fault. Decreasing abundance of aragonite away from the normal fault links the growth of the carbonate to the multistage hydrothermal mineralization associated with the fault.

Aragonite clusters are concentrated in picrolite, where they are interwoven with colloid-sized chrysotile, and show fractal growth habits. Areas adjacent to the clusters are sites of Mg enrichment of the serpentine medium relative to aragonite-free picrolite. It is interpreted that the aragonite clusters result from incursions of reactive seawater solutions through fine-scale pore structures in and around the fault in response to pressure gradients emanating from active tectonism. Cluster growth is interpreted to be a percolation phenomenon and provides a novel source of information on the nature of fine-scale reactive fluid flow, pore-space connectivity, and carbonate replacement processes in serpentinites.
Weathering of granodiorite and micaschists, and soil pollution at Mt. Mottarone (northern Italy)
Authors: Salvioli-Mariani E. , Toscani L. , Venturelli G.
Published: July 2002

At the top of Mt. Mottarone a thin level of micaschist, covered by soil, rests on granodioritic rocks. Both rock types underwent weathering with generation of new minerals and variation of the original chemical composition. The weathering produced phyllosilicates and Fe- and Al-hydroxides. Mass balance calculations on the basis of Zr immobility indicate that at least As, Bi, Cd, Mo and Sb were added to the micaschist, whereas the other elements were removed; the soil was also enriched in As, Bi, Cd, Mo and Sb during weathering. Dry and wet pollution was responsible for the addition of the elements listed above. On the other hand, Ca, Na, Mo and Sr were surely removed from the granodiorite during weathering, whereas Bi and Cu were added by percolation from the overlying micaschist. The chemical features of a spring issuing from granodiorite agree well with the element budget as deduced from the rock transformation. This is not the case, however, for a spring issuing from the micaschist.
Trends in Endovascular Aortic Repair Volume and Surveillance in the Era of the MISSION Act
Authors: Ponukumati Aravind S. , Newton Laura , Columbo Jesse A. , Soybel David , Davies Louise , Spangler Emily , Goodney Philip
Published: December 2024

This cohort study examines US veterans undergoing endovascular aortic repairs between 2000 and 2023 in the context of the 2018 Maintaining Internal Systems and Strengthening Integrated Outside Networks (MISSION) Act, which established a community care program to deliver health care to veterans outside Veterans Affairs facilities.
Characterization and Optimization of Vesicle Properties in bioPISA: from Size Distribution to Post‐Assembly Loading
Authors: Belluati Andrea , Bloch Adrian , Koynov Kaloian , Müller Nieva Mariana , Bagherabadi Mohadeseh , Andrieu‐Brunsen Annette , Kolmar Harald , Bruns Nico
Published: December 2024

This study investigates the formation and properties of vesicles produced via biocatalytic Polymerization‐Induced Self‐Assembly (bioPISA) as artificial cells. Methods for achieving size uniformity, including gentle centrifugation and sucrose gradient centrifugation, are explored, and the effects of stirring speed on vesicle morphology is investigated. The internal structure of the vesicles, characterized by a polymer‐rich matrix, is analyzed using fluorescence correlation spectroscopy (FCS). Additionally, the feasibility of loading macromolecules into pre‐formed vesicles is demonstrated using electroporation, and a fluorescent protein as well as enzymes for a cascade reaction were sucesfully incorporated into the fully assembled polymersomes. These findings provide a foundation for developing enzyme‐synthesized polymeric vesicles with controlled morphologies for various applications, e.g., in synthetic biology.
Anomalous Electron Doping in CdS to Promote the Efficiency Improvement in Sb2Se3 Thin Film Solar Cells
Authors: Cao Zixiu , Shao Bin , Ye Zhaoqing , Liu Chuanyu , Li Zhiqiang , Dong Jiabin , Wang Weihuang , Li Jianpeng , Liu Huizhen , Zhang Yi
Published: December 2024

The quality of P‐N heterojunction is crucial for the performance of antimony selenide (Sb2Se3) solar cells and thus attracting urgent attention. In this work, the monovalent cation Ag+ is doped in CdS, which enhances the N‐type conductivity of CdS film anomalously and reduces its parasitic absorption simultaneously. Furthermore, Ag doping of CdS promotes the diffusion of Cd into the Sb2Se3 layer, forming CdSb defects, which enhances the P‐type conductivity of Sb2Se3 and reduces the density of deep‐level centers. With further chemical etching treatment on the CdS surface, the quality of the CdS/Sb2Se3 P‐N heterojunction is distinctly improved, making the energy band alignment of CdS/Sb2Se3 more favorable for carrier transportation. Finally, a remarkable efficiency of 8.14%, which is the highest efficiency among those with Jsc of 30.96 mA cm−2, is achieved for vapor transport deposition processed Sb2Se3 solar cells. This work provides a strategy to simultaneously optimize the CdS and Sb2Se3 functional layers and enhance the quality of P‐N heterojunction for efficient Sb2Se3 solar cells.
Trivalent Rare Earth Ion‐Doped Metal Halide Perovskite Near‐Infrared Semiconductors for High‐Performance Optoelectronic Devices
Authors: Yang Tao , Wang Ya‐Kun , Liao Liang‐Sheng
Published: December 2024

Given the extensive application of near‐infrared (NIR) emission, the quest for efficient and versatile NIR semiconductors have attracted tremendous attention. Leveraging trivalent rare earth (RE3+) ions doping, the integration of metal halide perovskites with RE3+ ions makes it easy to achieve NIR‐II emission (1000–1700 nm). However, although showing promise in bioimaging, optical communication, and night vision, enhancing NIR‐II emission intensity to promote further progress in real‐world applications remains a challenge. This review summarizes the recent advancements in RE3+ ion‐doped perovskite NIR semiconductors, and discusses what kind of properties are needed and how to achieve desired optical properties in various applications. The review starts with the synthesis methods for various material types with rich examples. Following this, the mechanisms of strategies for optimizing NIR luminescence performance are discussed in detail. Furthermore, the review highlights their multifunctional applications both as an electrically driven emitter in NIR light‐emitting diodes (LEDs) and as a down‐conversion emitter in photovoltaic devices (PVs) or phosphor‐converted LEDs (pc‐LEDs). Finally, insights on how to fill the gap between current research and future goals are provided. This review aims to provide a deeper understanding of RE3+ ion‐doped NIR light‐emitting perovskite materials, and to promote the exploration of efficient NIR emitters.
3D Bioprinting and Artificial Intelligence‐Assisted Biofabrication of Personalized Oral Soft Tissue Constructs
Authors: Dai Yichen , Wang Peter , Mishra Apurva , You Kui , Zong Yuheng , Lu Wen Feng , Chow Edward Kai‐Hua , Preshaw Philip M , Huang Dejian , Chew Jacob Ren Jie , Ho Dean , Sriram Gopu
Published: December 2024

Regeneration of oral soft tissue defects, including mucogingival defects associated with the recession or loss of gingival and/or mucosal tissues around teeth and implants, is crucial for restoring oral tissue form, function, and health. This study presents a novel approach using three‐dimensional (3D) bioprinting to fabricate individualized grafts with precise size, shape, and layer‐by‐layer cellular organization. A multicomponent polysaccharide/fibrinogen‐based bioink is developed, and bioprinting parameters are optimized to create shape‐controlled oral soft tissue (gingival) constructs. Rheological, printability, and shape‐fidelity assays, demonstrated the influence of thickener concentration and print parameters on print resolution and shape fidelity. Artificial intelligence (AI)‐derived tool enabled streamline the iterative bioprinting parameter optimization and analysis of the interaction between the bioprinting parameters. The cell‐laden polysaccharide/fibrinogen‐based bioinks exhibited excellent cellular viability and shape fidelity of shape‐controlled, full‐thickness gingival tissue constructs over the 18‐day culture period. While variations in thickener concentrations within the bioink minimally impact the cellular organization and morphogenesis (gingival epithelial, connective tissue, and basement membrane markers), they influence the shape fidelity of the bioprinted constructs. This study represents a significant step toward the biofabrication of personalized soft tissue grafts, offering potential applications in the repair and regeneration of mucogingival defects associated with periodontal disease and dental implants.
Moisture‐Dependent Vibrational Dynamics and Phonon Transport in Nanocellulose Materials
Authors: Åhl Agnes , Nocerino Elisabetta , Veettil Unnimaya Thalakkale , Uetani Kojiro , Yu Shun , Armstrong Jeff , Juranyi Fanni , Bergström Lennart
Published: December 2024

Superinsulating nanofibrillar cellulose foams have the potential to replace fossil‐based insulating materials, but the development is hampered by the moisture‐dependent heat transport and the lack of direct measurements of phonon transport. Here, inelastic neutron scattering is used together with wide angle X‐ray scattering (WAXS) and small angle neutron scattering to relate the moisture‐dependent structural modifications to the vibrational dynamics and phonon transport and scattering of cellulose nanofibrils from wood and tunicate, and wood cellulose nanocrystals (W‐CNC). The moisture interacted primarily with the disordered regions in nanocellulose, and WAXS showed that the crystallinity and coherence length increased as the moisture content increased. The phonon population derived from directional‐dependent phonon density of states (GDOS) increased along the cellulose chains in W‐CNC between 5 and 8 wt% D2O, while the phonon population perpendicular to the chains remained relatively unaffected, suggesting that the effect of increased crystallinity and coherence length on phonon transport is compensated by the moisture‐induced swelling of the foam walls. Frequency scaling in the low‐energy GDOS showed that materials based on hygroscopic and semicrystalline nanocellulose falls in between the predicted behavior for solids and liquids. Phonon‐engineering of hygroscopic biopolymer‐based insulation materials is promoted by the insights on the moisture‐dependent phonon transport.
Engineering Triboelectric Paper for Energy Harvesting and Smart Sensing
Authors: Zhang Renyun , Chen Dabo , Hummelgård Magnus , Blomquist Nicklas , Dahlström Christina , Chen Wenshuai , Li Jiayong , Örtegren Jonas , Wang Zhong Lin
Published: December 2024

Triboelectric nanogenerators (TENGs) represent a promising technology for energy harvesting and self‐powered sensing with a wide range of applications. Despite their potential, challenges such as the need for cost‐effective, large‐area electrodes and engineering sustainable triboelectric materials remain, especially given the impending restrictions on single‐use engineering plastics in Europe. To address these challenges, engineering nano‐graphite‐coated paper is presented as a sustainable and high‐performance alternative for triboelectric layers. Moreover, this material, which can be produced on an industrial scale, offers a viable replacement for metal electrodes. The combination of nano‐graphite and paper, with its large contact area and inherent surface roughness, enables ultra‐high power densities exceeding 14 kW m−2, driven by electrostatic discharge at the surface. Beyond energy harvesting, smart sensors are developed for floors and walls that detect movements for security purposes and smart sheets that monitor body movements and physiological activities during sleep. The findings highlight the potential of this engineering paper to serve as an eco‐friendly alternative to engineering plastics in TENGs and electrodes, opening new avenues for future applications.
Machine Learning‐Assisted Hybrid Package of White Light‐Emitting Diodes Employing Quantum Dots and Phosphor
Authors: Gao Fengyun , Yang Hao , Tong Changdong , Lu Yijun , Chen Zhong , Guo Weijie
Published: December 2024

White light‐emitting diodes (WLEDs), known for their high brightness, high efficiency, and long lifetime, are widely utilized in the backlight of liquid crystal displays. However, it is still difficult to improve the color gamut of WLEDs while maintaining the L50 lifetime. The luminous characteristics of WLEDs employing different combinations of quantum dots and phosphor are investigated in this work. Additionally, investigations on the L50 lifetime for WLEDs are carried out by employing a two‐step accelerated stress method. Finally, an ensemble machine learning model is proposed to predict the L50 lifetime of WLEDs, achieving high predictive accuracy with R2 of 0.986.