bluuebunny/crossref_metadata_2025 huggingface dataset:
A Coroutine Approach to Parsing
Authors: Samet Hanan
Published: October 2002

A method is presented for parsing syntactic constructs that are permitted to appear independently anywhere in a program. Some examples include comments, macros, and constructs for conditional compilation. Each such construct is defined by its own grammar and parsed by a separate coroutine. The coroutine model of parsing allows the program text to be parsed in one pass despite the syntactic inconsistencies among the program text and the additional constructs. The usefulness of the model is demonstrated by showing how a production language parsing method is extended to handle multiple syntax specifications. The implementation of conditional compilation by carrying along two parses in a coroutine manner is also given. The utility of the model is further demonstrated by showing its adaptation to a recursive descent parser.
A Proof System for Communicating Sequential Processes
Authors: Apt Krzysztof R. , Francez Nissim , de Roever Willem P.
Published: October 2002

An axiomatic proof system is presented for proving partial correctness and absence of deadlock (and failure) of communicating sequential processes. The key (meta) rule introduces cooperation between proofs, a new concept needed to deal with proofs about synchronization by message passing. CSP's new convention for distributed termination of loops is dealt with. Applications of the method involve correctness proofs for two algorithms, one for distributed partitioning of sets, the other for distributed computation of the greatest common divisor of
n
numbers.
Optimizing memory usage in the polyhedral model
Authors: Quilleré Fabien , Rajopadhye Sanjay
Published: October 2002

The
polyhedral model
provides a single unified foundation for systolic array synthesis and automatic parallelization of loop programs. We investigate the problem of memory reuse when compiling Alpha (a functional language based on this model). Direct compilation would require unacceptably large memory (for example

O(n
3
)

for matrix multiplication). Researchers have previously addressed the problem of memory reuse, and the analysis that this entails for projective memory allocations. This paper addresses, for a given schedule, the choice of the projections so as to minimize the volume of the residual memory. We prove tight bounds on the number of linearly independent projection vectors. Our method is constructive, yielding an optimal memory allocation. We extend the method to modular functions, and deal with the subsequent problems of code generation. Our ideas are illustrated on a number of examples generated by the current version of the Alpha compiler.
Specification and verification of liveness properties of cyclic, concurrent processes
Authors: Reed Joylyn , Yeh Raymond T.
Published: October 2002

A technique is described for software specification and verification of concurrent, distributed systems. The complete specification of a program is given in terms of a hierarchical structure of module specifications. Module external specifications are abstract; module internal specifications are descriptions of internal implementations, either in terms of submodules or actual code. The verification that an implementation satisfies its specification is language independent for the former and language dependent for the latter. Distinguishing the liveness properites provided by a module and the liveness properties required by a module (from its comodules) allows the specification and verification of a given module to be independent from the specification and verification of its comodules.
Fairness in parallel programs: the transformational approach
Authors: Olderog Ernst-Rüdiger , Apt Krzysztof R.
Published: October 2002

Program transformations are proposed as a means of providing fair parallelism semantics for parallel programs with shared variables. The transformations are developed in two steps. First, abstract schedulers that implement the various fairness policies are introduced. These schedulers use random assignments z := ? to represent the unbounded nondeterminism induced by fairness. Concrete schedulers are derived by suitably refining the ?. The transformations are then obtained by embedding the abstract schedulers into the parallel programs. This embedding is proved correct on the basis of a simple transition semantics. Since the parallel structure of the original program is preserved, the transformations also provide a basis for syntax-directed proofs of total correctness under the fairness assumption. These proofs make use of infinite ordinals.
The denotational semantics of dynamic networks of processes
Authors: de Bruin Arie , Böhm Wim
Published: October 2002

DNP (dynamic networks of processes) is a variant of the language introduced by Kahn and MacQueen [11, 12]. In the language it is possible to create new processes dynamically. We present a complete, formal denotational semantics for the language, along the lines sketched by Kahn and MacQueen. An informal explanation of the formal semantics is also given.
Lessons learned about one-way, dataflow constraints in the Garnet and Amulet graphical toolkits
Authors: Vander Zanden Bradley T. , Halterman Richard , Myers Brad A. , McDaniel Rich , Miller Rob , Szekely Pedro , Giuse Dario A. , Kosbie David
Published: October 2002

One-way, dataflow constraints are commonly used in graphical interface toolkits, programming environments, and circuit applications. Previous papers on dataflow constraints have focused on the design and implementation of individual algorithms. In contrast, this article focuses on the lessons we have learned from a decade of implementing competing algorithms in the Garnet and Amulet graphical interface toolkits. These lessons reveal the design and implementation tradeoffs for different one-way, constraint satisfaction algorithms. The most important lessons we have learned are that (1) mark-sweep algorithms are more efficient than topological ordering algorithms; (2) lazy and eager evaluators deliver roughly comparable performance for most applications; and (3) constraint satisfaction algorithms have more than adequate speed, except that the storage required by these algorithms can be problematic.
More dynamic object reclassification
Authors: Drossopoulou Sophia , Damiani Ferruccio , Dezani-Ciancaglini Mariangiola , Giannini Paola
Published: October 2002

Reclassification
changes the class membership of an object at run-time while retaining its identity. We suggest language features for object reclassification, which extend an imperative, typed, class-based, object-oriented language.We present our proposal through the language
Fickle
⋄⋄
. The imperative features, combined with the requirement for a static and safe type system, provided the main challenges. We develop a type and effect system for
Fickle
⋄⋄
and prove its soundness with respect to the operational semantics. In particular, even though objects may be reclassified across classes with different members, there will never be an attempt to access nonexisting members.
CHI as a cross-tribal community
Authors: Marcus Aaron
Published: October 2002

Fast Forward
presents me with an opportunity to think about where user-interface design has been over the past four decades in which I have worked and about its future. I hope you will enjoy and benefit from joining me in this ongoing discussion. Your feedback is welcome.
Keeping e-business in perspective
Authors: Coltman Tim , Devinney Timothy M. , Latukefu Alopi S. , Midgley David F.
Published: October 2002

As some firms have discovered (usually the hard way), e-business does not fit every business.
Scaling mining algorithms to large databases
Authors: Bradley Paul , Gehrke Johannes , Ramakrishnan Raghu , Srikant Ramakrishnan
Published: October 2002

Which insights about data structure make it possible to analyze the very large databases collected by Internet, business, scientific, and government applications?
Simple, state-based approaches to program-based anomaly detection
Authors: Michael C. C. , Ghosh Anup
Published: October 2002

This article describes variants of two state-based intrusion detection algorithms from Michael and Ghosh [2000] and Ghosh et al. [2000], and gives experimental results on their performance. The algorithms detect anomalies in execution audit data. One is a simply constructed finite-state machine, and the other two monitor statistical deviations from normal program behavior. The performance of these algorithms is evaluated as a function of the amount of available training data, and they are compared to the well-known intrusion detection technique of looking for novel
n
-grams in computer audit data.
LegoSim
Authors: Röblitz Thomas , Mueller Frank , Bühn Oliver
Published: October 2002

The contributions of this work are twofold. First, we describe the design and implementation of a simulation environment for an open-source embedded kernel and an intuitive user interface to complement it. Second, the simulator can be used for embedded program development and research as well as instructional purposes in embedded system classes as a replacement or a complement to hands-on experiments with embedded devices.The technical sections of this article stress the suitability of POSIX Threads (Pthreads) in approximating kernel operations in the simulation environment. We specify the prerequisites for using Pthreads as a means to approximate embedded task execution and suggests an I/O-based representation of device information. The experience gained with a sample implementation stresses the importance of a proper match between a Pthreads implementation and an embedded kernel. We demonstrate the adequacy of both the simulation environment and a graphical user interface to aid program development and debugging. Furthermore, the separation of the simulation component from the user interface provides opportunities to utilize each component separately or even combine them with other components. The simulation environment is publically available, and instructions for installation and use are included in the Appendix. The combination of technical solutions is a contribution toward embedded system simulation, an area that has not been studied much.
Revisiting quantification in autoepistemic logic
Authors: Kaminski Michael , Rey Guy
Published: October 2002

In this article, we introduce
first-order
autoepistemic logic. Our definition is
semantical
and is based on the intuition similar to that lying behind the definition of first-order default logic. Thus, our definition of first-order autoepistemic logic well complies with that of first-order default logic and circumscription, providing a substantial evidence for its acceptance.
DyRT
Authors: James Doug L. , Pai Dinesh K.
Published: October 2002

In this paper we describe how to simulate geometrically complex, interactive, physically-based, volumetric, dynamic deformation models with
negligible main CPU costs.
This is achieved using a

Dy
namic
R
esponse
T
exture,

or
DyRT,
that can be mapped onto any conventional animation as an optional rendering stage using commodity graphics hardware. The DyRT simulation process employs precomputed modal vibration models excited by rigid body motions. We present several examples, with an emphasis on bone-based character animation for interactive applications.
Register tiling in nonrectangular iteration spaces
Authors: Jiménez Marta , Llabería José M. , Fernández Agustín
Published: October 2002

Loop tiling is a well-known loop transformation generally used to expose coarse-grain parallelism and to exploit data reuse at the cache level. Tiling can also be used to exploit data reuse at the register level and to improve a program's ILP. However, previous proposals in the literature (as well as commercial compilers) are only able to perform multidimensional tiling for the register level when the iteration space is rectangular. In this article we present a new general algorithm to perform multidimensional tiling for the register level in both rectangular and nonrectangular iteration spaces. We also propose a simple heuristic to determine the tiling parameters at this level. Finally, we evaluate our method using as benchmarks typical linear algebra algorithms having nonrectangular iteration spaces and compare our proposal against hand-optimized vendor-supplied numerical libraries and against commercial compilers able to perform optimizing code transformations such as inner unrolling, unroll-and-jam, and software pipelining. Measurements were taken on three different superscalar microprocessors. Results will show that our method outperforms the native compilers (showing speedups of 2.5 in average) and matches the performance of vendor-supplied numerical libraries. The general conclusion is that compiler technology can make it possible for nonrectangular loop nests to achieve as high performance as hand-optimized codes.
Partitioning sequential programs for CAD using a three-step approach
Authors: Vahid Frank
Published: October 2002

Many computer-aided design problems involve solutions that require the partitioning of a large sequential program written in a language such as C or VHDL. Such partitioning can improve design metrics such as performance, power, energy, size, input/output lines, and even CAD tool run-time and memory requirements, by partitioning among hardware modules, hardware and software processors, or even among time-slices in reconfigurable computing devices. Previous partitioning approaches typically preselect the granularity at which the program is partitioned. In this article, we define three distinct partitioning steps: procedure determination, preclustering, and
N
-way partitioning, with the first two steps focusing on granularity selection. Using three steps instead of one can provide for a more thorough design space exploration and for faster partitioning. We emphasize the first two steps in this article since they represent the most novel aspects. We illustrate the approach on an example, provide results of several experiments, and point to the need for future research that more fully automates the three-step approach.
Career redux
Authors: Denning Peter J.
Published: October 2002

How can one design a career when career as an institution is dead? Entrepreneurs have an answer.
Remote automatic doorman via the internet
Authors: Palacios Rafael
Published: October 2002

Using a low-end PC and a Web browser to operate a door two buildings away.
Specification, implementation, and deployment of components
Authors: Crnkovic Ivica , Hnich Brahim , Jonsson Torsten , Kiziltan Zeynep
Published: October 2002

Clarifying common terminology and exploring component-based relationships.
Implicit multilevel modeling in flexible business environments
Authors: Jardim-Gonçalves Ricardo , Steiger-Garção Adolfo
Published: October 2002

A methodology for supporting the integration and interoperability of applications in changing business environments.
Lessons learned from a nationwide CBD promotion project
Authors: Kim Soo Dong
Published: October 2002

Sharing insights gained from a large-scale initiative in an Asian context.
A simple interprocedural register allocation algorithm and its effectiveness for LISP
Authors: Steenkiste Peter A. , Hennessy John L.
Published: October 2002

Register allocation is an important optimization in many compilers, but with per-procedure register allocation, it is often not possible to make good use of a large register set. Procedure calls limit the improvement from global register allocation, since they force variables allocated to registers to be saved and restored. This limitation is more pronounced in LISP programs due to the higher frequency of procedure calls. An interprocedural register allocation algorithm is developed by simplifying a version of interprocedural graph coloring. The simplification corresponds to a bottom-up coloring of the interference graph. The scheme is evaluated using a number of LISP programs. The evaluation considers the scheme's limitations and compares these “software register windows” against the hardware register windows used in the Berkeley RISC and SPUR processors.
Efficient high-level iteration with accumulators
Authors: Cameron Robert D.
Published: October 2002

Accumulators
are proposed as a new type of high-level iteration construct for imperative languages. Accumulators are user-programmed mechanisms for successively combining a sequence of values into a single result value. The accumulated result can either be a simple numeric value such as the sum of a series or a data structure such as a list. Accumulators naturally complement constructs that allow iteration through user-programmed sequences of values such as the iterators of CLU and the generators of Alphard. A practical design for high-level iteration is illustrated by way of an extension to Modula-2 called Modula Plus. The extension incorporates both a redesigned mechanism for iterators as well as the accumulator design. Several applications are illustrated including both numeric and data structure accumulation. It is shown that the design supports efficient iteration both because it is amenable to implementation via in-line coding and because it allows high-level iteration concepts to be implemented as encapsulations of efficient low-level manipulations.
A mechanism for environment integration
Authors: Clemm Geoffrey , Osterweil Leon
Published: October 2002

This paper describes research associated with the development and evaluation of Odin-an environment integration system based on the idea that tools should be integrated around a centralized store of persistent software objects. The paper describes this idea in detail and then presents the Odin architecture, which features such notions as the typing of software objects, composing tools out of modular tool fragments, optimizing the storage and rederivation of software objects, and isolating tool interconnectivity information in a single centralized object. The paper then describes some projects that have used Odin to integrate tools on a large scale. Finally, it discusses the significance of this work and the conclusions that can be drawn about superior software environment architectures.
On Kilbury's modification of Earley's algorithm
Authors: Leiss Hans
Published: October 2002

We improve on J. Kilbury's proposal to interchange “predictor” and “scanner” in Earley's parser. This modification of Earley's parser can trivially be combined with those suggested by S. Graham, M. Harrison, and W. Ruzzo, leading to smaller parse tables and almost the power of lookahead 1. Along these lines we can also obtain Earley-parsers having partial lookahead
r
≥ 1, without storing right contexts. Parse trees with shared structure can be stored in the parse tables directly, rather than constructing the trees from “dotted rules."
Momo, Dogen, and the Commodification of Time
Authors: Loy David , Goodhew Linda
Published: October 2002

The odd thing was, no matter how much time he saved, he never had any to spare; in some mysterious way, it simply vanished. Imperceptibly at first, but then quite unmistakably, his days grew shorter and shorter. (Momo 65) One of the most remarkable novels of the late twentieth century is Momo, by the German writer Michael Ende. Although apparently written for children, it contains profound insights into our modern attitude toward time. Is it a coincidence that Ende later became interested in Buddhism? He visited Japan several times: the first trip in 1977 included a discussion with a Zen priest; the second time in 1989 to marry his second wife, SATO Mariko. This essay will explore the deep resonances between Ende's view of time in Momo and the Buddhist perspective on time, particularly as expressed by the Japanese Zen master Dogen (1200-1253). These resonances are of more than literary or historical interest: understanding what Ende and Dogen have to say about time gives us important insight into how we experience time today.
Xanthoria karrooensis and X. alexanderbaai (Teloschistaceae), two new lichen species from southern Africa
Authors: Kärnefelt I. , Kondratyuk S. , Søchting U. , Frödén P.
Published: October 2002

Two new species, Xanthoria karrooensis S. Kondratyuk & Kärnefelt and Xanthoria alexanderbaai S. Kondratyuk & Kärnefelt, both apparently endemic to South Africa, are described and illustrated. Other xanthorioid species known from southern Africa are listed in a Table and a preliminary key is provided for the African species. The new species are compared with a number of presumably related species, and a Table is provided comparing the character states for the new species and related species.
Episode of Strengthened Summer Monsoon Climate of Younger Dryas Age on the Loess Plateau of Central China
Authors: Zhisheng An , Porter Stephen C. , Weijian Zhou , Yanchou Lu , Donahue Douglas J. , Head M. J. , Xihuo Wu , Jianzhang Ren , Hongbo Zheng
Published: October 2002

The Baxie loess section, just east of the Tibetan Plateau, contains evidence showing that the Asian monsoon climate experienced an abrupt reversal near the end of the last glacial age. Rapid deposition of dust under cool, dry full-glacial conditions gave way to an interval of soil development and reduced dust influx attributed to a strengthening of the warm, moist summer monsoon. A subsequent abrupt increase in dust deposition, a response to a weakening of the summer monsoon, was later followed by renewed soil formation as summer monsoon circulation again intensified during the early Holocene. By one interpretation, the thin upper loess is a manifestation of the European Younger Dryas oscillation; however, in this case the available 14C ages require either that (1) onset of loess deposition lagged the beginning of the Younger Dryas event in Europe by as much as 2000 calibrated 14C years or (2) all the 14C ages are too young, possibly due to contamination. Alternatively, the late-glacial paleosol, the top of which is synchronous with the abrupt end of the late-glacial δ18O anomaly in the Dye 3 Greenland ice core, records the Younger Dryas event. Such an interpretation is consistent with general circulation model simulations of Younger Dryas climate that show strong seasonality and a strengthened summer monsoon, and with marine cores from the western Pacific Ocean that contain evidence of pronounced cooling of surface waters during Younger Dryas time.
Soil-Geomorphic Analysis of Late-Pleistocene Glacial Sequences in the McGee, Pine, and Bishop Creek Drainages, East-Central Sierra Nevada, California
Authors: Berry Margaret E.
Published: October 2002

Late-Pleistocene glacial sequences at McGee, Pine, and Bishop creeks, in the east-central Sierra Nevada, are resolvable into distinct relative-age groups on the basis of soil development, the weathering of surface and subsurface clasts, and geomorphic criteria. The data differentiate moraines from Tioga and Tahoe glaciations at McGee Creek, and Tioga, Tahoe, and pre-Tahoe/post-Sherwin glaciations at Pine and Bishop creeks; no moraines from a Tenaya glaciation are differentiated by the data, perhaps because the soil-geomorphic methods are not sensitive enough to resolve small age differences between moraines. The lack of fine age resolution is probably due to a combination of factors, including (1) slow rates of soil development, (2) low amounts of atmospheric dust added to the soils, (3) the susceptibility of crest soils to erosion, and (4) the susceptibility of footslope soils to burial by colluvium. Age resolution is improved by evaluating soils at both the moraine crests and the relatively wetter footslope sites, and by basing age assignments on a combination of macro- and micromorphologic soil properties, the disintegration of subsurface clasts, and parameters of surface-clast weathering.
Late Stage 5 Glacio-isostatic Sea in the St. Lawrence Valley, Canada and United States
Authors: Occhietti Serge , Balescu Sanda , Lamothe Michel , Clet Martine , Cronin Thomas , Ferland Pierre , Pichet Pierre
Published: October 2002

Although post-glacial marine sediments of late Wisconsinan and early Holocene age are common in eastern Canada and the northeastern United States, remnants of older Pleistocene marine sediments are scarce. A fossiliferous marine clay that predates the classical Wisconsinan was recently discovered in the St. Lawrence Valley. A dominantly estuarine environment is inferred from the geochemistry of the shells (δ18O = −7.1) and from benthic foraminifer and ostracode assemblages. The clay indicates a marine invasion (Cartier Sea) shallower and probably shorter than that during the upper late Wisconsinan Champlain Sea episode (12,000–9,500 yr B.P.). The pollen content shows that regional vegetation during the marine episode began as open tundra, then became a Betula and Alnus crispa forest, reached a climatic optimum with Quercus, Corylus, and Abies, and concluded as a Pinus/Picea boreal forest. A corrected infrared stimulated luminescence age of 98,000 ± 9000 yr is compatible with the epimerization ratio of shells. The Cartier Sea resulted from a post-glacial glacio-isostatic marine invasion in the St. Lawrence lowlands. It probably occurred during late stage 5 and is tentatively assigned to the transition of oxygen isotope substages 5b/5a. This marine episode dates to stage 5 of the preceding continental glacier which extended to middle latitudes in NE America.
Late Holocene Phytolith and Carbon-Isotope Record from a Latosol at Salitre, South-Central Brazil
Authors: Alexandre Anne , Meunier Jean-Dominique , Mariotti Andre , Soubies Francois
Published: October 2002

The reliability of paleovegetation records inferred from soil phytolith assemblages and SOM (soil organic matter) carbon isotope analysis was examined in light of previous pollen and charcoal reconstructions. The sampled latosol is located in south-central Brazil (Salitre), at a boundary between forest and cerrado. The derived mean age of phytoliths and SOM at each level is the result of a balance between continuous translocation and selective dissolution. It increases with depth in a regular, quantifiable fashion that allows paleoenvironmental interpretation. Phytoliths and SOM tracers first record a savanna phase, associated with the last Holocene long dry period occurring between ca. 5500 and 4500 yr B.P. Two periods of tree community development followed, between ca. 4000 and 3000 and after ca. 970 yr. B.P., leading to the present cerrado/forest association. The dry spell interrupted this trend about 970 ± 60 yr B.P. The second development of woody elements was contemporaneous with an increase in anthropogenic fires. Therefore, climate was more important than fires and human activities in constraining the growth of vegetation during the last nine centuries at Salitre. More generally, despite pedogenic processes, soil phytoliths and δ13C values of the SOM may be accurate tracers of vegetation changes.
Quantitative proteomics: the copy number of pyruvate dehydrogenase is more than 102‐fold lower than that of complex III in human mitochondria
Authors: Murray James , Gilkerson Robert , Capaldi Roderick A
Published: October 2002

Pyruvate dehydrogenase (PDH) and complex III are two key protein complexes in mitochondrial metabolic activity. Using a novel quantitative Western blotting method, we find that PDH and complex III exist at a steady‐state ratio of 1:100, 1:128 and 1:202 in HeLa cell extracts, fibroblast mitochondria and heart tissue mitochondria, respectively. This difference in stoichiometry is reflected in the immunogold labeling intensities of the two complexes and by the much more sparse distribution of PDH in fluorescence microscopy. In Rho0 fibroblasts there is a 64% reduction of complex III but the concentration of PDH remains the same as wild‐type.
Study of the cytotoxic effect of a peptidic inhibitor of the p53–hdm2 interaction in tumor cells
Authors: Chène Patrick , Fuchs Jean , Carena Ilaria , Furet Pascal , Garcı́a Echeverrı́a Carlos
Published: October 2002

Inhibitors of the p53–hdm2 interaction are attractive molecules for stimulating the p53 pathway in tumors. In this report, an inhibitor of the p53–hdm2 interaction, the AP peptide, is used to activate p53 in tumor cells expressing various levels of hdm2 protein. It induces apoptosis only in cells expressing high endogenous levels of hdm2 protein. The absence of apoptosis in tumor cells with low hdm2 levels is due not to alterations in the p53‐dependent apoptotic pathway but to a different regulation of this pathway. The peptide is also less toxic for non‐tumor cells than for tumor cells overexpressing the hdm2 protein.
In vitro differentiation of a cloned bovine mammary epithelial cell
Authors: ROSE MICHAEL T. , ASO HISASHI , YONEKURA SHINICHI , KOMATSU TOKUSHI , HAGINO AKIHIKO , OZUTSUMI KYOUHEI , OBARA YOSHIAKI
Published: October 2002

The aim of the study was to establish in vitro a bovine mammary epithelial cell (MEC) clone, able to respond to mitogenic growth factors and to lactogenic hormones. Mammary tissue from a 200-d pregnant Holstein cow was used as a source of MEC, from which a clone was established through a process of limiting dilution. When plated on plastic, the cells assumed a monolayer, cobblestone, epithelial-like morphology, with close contact between cells. Inclusion of IGF-1 and EGF in the media significantly increased the number of cells 5 d after plating. All cells stained strongly for cytokeratin and moderately for vimentin at young and old passage stages, indicating the epithelial nature of this cell clone. When the cells were plated at a high density on a thin layer of a commercial extracellular matrix preparation (Matrigel), lobular, alveoli-like structures developed within approximately 5 d, with a clearly visible lumen. When cells were plated onto Matrigel in differentiation media (containing lactogenic hormones), detectable quantities of α-casein were present in the media and particularly on the lumen side of the structures. Omission of one of the lactogenic hormones (insulin, prolactin or hydrocortisone) reduced α-casein release to the limit of detection of the assay used. Lactoferrin was also produced when the cells were plated on Matrigel, again principally on the lumen side of the lobules, though this was independent of the lactogenic hormones. By passage 40, the cells had senesced, and it was not possible to induce α-casein or lactoferrin production. This study notes the establishment of a functional bovine mammary epithelial cell clone, which is responsive to mitogenic and lactogenic hormones and an extracellular matrix.
ELISA for monitoring the cleavage of β-casein at site Lys28–Lys29 by plasmin during Comté cheese ripening
Authors: SENOCQ DANIEL , DUPONT DIDIER , ROLET-RÉPÉCAUD ODILE , LEVIEUX DIDIER
Published: October 2002

Proteolysis of casein is the principal cause of textural changes and flavour
development in ripened cheese (Fox & McSweeney, 1996). Caseins are degraded into
small peptides and free amino acids during a complex process, described by Grappin
et al. (1985) as a two-step scheme. Caseins are initially broken down into large,
well characterised fragments. This initial step, called primary proteolysis, is catalysed
principally by the residual coagulant (chymosin and pepsin), and to a variable extent
by endogenous milk proteases, such as plasmin, cathepsin D, and possibly somatic
cell proteinases. Enzymes originating from either rennet or milk are active in most
ripened cheese varieties. However, their relative contributions vary substantially
depending on manufacturing practices. For instance, in Swiss-type cheeses, cooking
the curd extensively inactivates the coagulant, and simultaneously enhances plasmin
activity, which therefore becomes predominant (Ollikainen & Kivela, 1989).
Promoting Democratic Governance and Preventing the Recurrence of Conflict: The Role of the United Nations Development Programme in Post-Conflict Peace-Building
Authors: SANTISO CARLOS
Published: October 2002

Promoting democracy and strengthening good governance have become core components of post-conflict peace-building initiatives of the United Nations (UN). An often overlooked dimension of the analysis of UN peace support operations has been the crucial role played by the United Nations Development Programme (UNDP) at the critical juncture linking peacekeeping to sustainable development. UN peace operations in Central America over the last decade have pioneered the organisation's involvement in the uncharted territory of post-conflict peace building. UNDP's Central American experience was the first step in the organisation's evolution away from providing traditional development assistance, towards playing an active and openly political role in post-conflict democracy building and governance reform. This new role of the UNDP has had dramatic repercussions on its mandate, administrative structures, corporate policies and operational strategies. The current institutional renewal of UNDP has its roots in its endorsement of democratic governance as essential dimensions of its mandate to promote sustainable human development. This article assesses the significance, promises and dilemmas of the governance agenda for UNDP and analyses the scope, nature and institutionalisation of democracy and governance programmes within UNDP, using Central America as a case study. It argues that the future of UNDP democracy assistance will largely depend on how successful it is at resolving the inherent tensions between democracy promotion and national sovereignty, while retaining its multilateral approach to peace and democracy.
Feeding, respiration, and excretion by the tropical sea urchin Tripneustes gratilla (Echinodermata: Echinoidea) from the Philippines
Authors: Dy Danilo T. , Uy Frederick A. , Coralles Christine M.
Published: October 2002

The rates of ingestion, egestion, ammonium excretion, and CO2 respiration of Tripneustes gratilla (Echinodermata: Echinoidea) from a shallow water embayment at eastern Mactan Island, central Philippines were examined. There was no significant difference in weight-specific feeding rate with the three macrophytes (Sargassum polycystum, Thalassia hemprichii, and Kappaphycus alvarezii). The power function equation, M=KWb fitted well with the weight-specific egestion rates ((r2=0·93), weight-specific CO2 respiration rates (r2=0·92) and ammonium excretion rates (r2=0·86). Weight-specific egestion rates, CO2 respiration and ammonium excretion were indirectly proportional to body weight. For weight-specific egestion rate (in μg DW faeces/g DW urchin-h), the regression coefficient, b and constant, K were −2·31±0·68 (mean±SE) (P=0·02) and 6359·55±5394·31 (P=0·29), respectively. The b and K for CO2 respiration were −1·28±0·48 (P=0·04) and 39·72±10·59 (P=0·01), respectively. For ammonium excretion, the b and K were −1·03±0·46 (P=0·11) and 262·51±56·89 (P=0·02), respectively.
Surgery on closed 4-manifolds with free fundamental group
Authors: KRUSHKAL VYACHESLAV S. , LEE RONNIE
Published: October 2002

The 4-dimensional topological surgery conjecture has been established for a class
of groups, including the groups of subexponential growth (see [6], [13] for recent
developments), however the general case remains open. The full surgery conjecture
is known to be equivalent to the question for a class of canonical problems with free
fundamental group [5, chapter 12]. The proof of the conjecture for ‘good’ groups relies on the disk embedding theorem (see [5]), which is not presently known to hold for
arbitrary groups. However, in certain cases it may be shown that surgery works even
when the disk embedding theorem is not available for a given fundamental group
(such results still use the disk-embedding theorem in the simply-connected setting,
proved in [3]). For example, this is possible when the surgery kernel is represented
by π1-null spheres [4], or more generally by a π1-null submanifold satisfying a certain condition on Dwyer's filtration on second homology [7]. Here we state another
instance when the surgery conjecture holds for free groups. The following results are
stated in the topological category.
Characterizing complex craniodental patterns related to feeding behaviour in ungulates: a multivariate approach
Authors: Mendoza Manuel , Janis Christine M. , Palmqvist Paul
Published: October 2002

This work examines whether stepwise discriminant function analysis of a suite of craniodental variables enables feeding behaviour and habitat preferences to be identified in fossil ungulates. There are several morphological features of the ungulate skull, mandible and dentition that are well correlated with dietary adaptations, and thus can be used for estimating the feeding ecology of extinct taxa. However, most studies have followed an univariate approach for characterizing the relationship between diet and craniodental structure in extant ungulates (but see Pérez‐Barberia & Gordon, 2001), even though such a relationship has been revealed to be complex because of functional, phylogenetic and biomechanical constraints. In this paper a multivariate perspective is followed, developing quadratic discriminant functions for pairwise comparisons of dietary/habitat groups in modern species. Given that the stepwise method for selecting the morphological variables to be included in the algorithms was used, alternative discriminant functions are provided. Results obtained show that these algorithms reclassify correctly the species according to their feeding and habitat ecology, and thus may be useful for obtaining reliable palaeoautecological inferences (i.e. those related to the life style of extinct species, such as feeding ecology and habitat preferences) when applied to extinct ungulate taxa.
An on-wafer probe array for measuring two-dimensional ion flux distributions in plasma reactors
Authors: Kim Tae Won , Ullal Saurabh J. , Vahedi Vahid , Aydil Eray S.
Published: October 2002

In plasma etching processes, the spatial distribution of ion flux across the wafer surface determines the uniformity and profile evolution when etching is ion limited. We have designed and built a two-dimensional array of planar Langmuir probes on a 200 mm diameter silicon wafer to measure the radial (r) and azimuthal (θ) variation of ion flux impinging on the wafer surface in plasma etching reactors. Herein we demonstrate the use of this probe array to obtain two-dimensional ion flux distributions in Ar, Cl2, and Cl2/HBr/He discharges in an inductively coupled plasma reactor. The results obtained using the probe array are in good agreement with Langmuir probe measurements but also reveal azimuthal asymmetries, due to irregularities in chamber geometry such as the pumping port and radio frequency coil configuration, that cannot be detected using radially movable Langmuir probes. The probe array can also be used to investigate the spatiotemporal fluctuations of the ion flux in the 1–100 Hz range.
Effect of helium ion implantation and annealing on the relaxation behavior of pseudomorphic Si1−xGex buffer layers on Si (100) substrates
Authors: Luysberg M. , Kirch D. , Trinkaus H. , Holländer B. , Lenk St. , Mantl S. , Herzog H.-J. , Hackbarth T. , Fichtner P. F. P.
Published: October 2002

The influence of He implantation and annealing on the relaxation of Si0.7Ge0.3 layers on Si (100) substrates is investigated. Proper choice of the implantation energy results in a narrow defect band ≈100 nm underneath the substrate/epilayer interface. During annealing at 700–1000 °C, He-filled bubbles are created, which act as sources for misfit dislocations. Efficient annihilation of the threading dislocations is theoretically predicted, if a certain He bubble density with respect to the buffer layer thickness is maintained. The variation of the implantation dose and the annealing conditions changes density and size of spherical He bubbles, resulting in characteristic differences of the dislocation structure. Si1−xGex layers with Ge fractions up to 30 at. % relax the initial strain by 70% at an implantation dose of 2×1016 cm−2 and an annealing temperature as low as 850 °C. Simultaneously, a low threading dislocation density of 107 cm−2 is achieved. The strain relaxation mechanism in the presence of He filled bubbles is discussed.
Electric probes for plasmas: The link between theory and instrument
Authors: Demidov V. I. , Ratynskaia S. V. , Rypdal K.
Published: October 2002

Electric probe methods for diagnostics of plasmas are reviewed with emphasis on the link between the appropriate probe theories and the instrumental design. The starting point is an elementary discussion of the working principles and a discussion of the physical quantities that can be measured by the probe method. This is followed by a systematic classification of the various regimes of probe operation and a summary of theories and methods for measurements of charged particle distributions. Application of a single probe and probe clusters for measurements of fluid observables is discussed. Probe clusters permit both instantaneous and time-averaged measurements without sweeping the probe voltage. Two classes of applications are presented as illustrations of the methods reviewed. These are measurements of cross sections and collision frequencies (plasma electron spectroscopy), and measurements of fluctuations and anomalous transport in magnetized plasma.
State-to-state differential cross sections for spin–multiplet-changing collisions of NO(X 2Π1/2) with argon
Authors: Elioff Michael S. , Chandler David W.
Published: October 2002

Rotational state-resolved differential cross sections (DCS) for spin–multiplet-changing collisions of NO(X 2Π1/2→X 2Π3/2) with Ar are presented and compared to results from previous experimental and theoretical studies performed on the NO/Ar system. A crossed molecular beam apparatus coupled with velocity-mapped ion imaging was used to measure complete (θ=0°–180°) DCS for scattering of NO(X 2Π1/2,j=0.5) into NO(X 2Π3/2,j′) rotational states ranging from j′=1.5 to j′=12.5. Scattered products were detected by state-selective ionization using (1+1′) resonance-enhanced multiphoton ionization via the A 2Σ+ state. State-to-state DCS were extracted in the center-of-mass frame of reference for energy transfer at a center-of-mass collision energy of ∼530 cm−1. Studies performed using horizontally and vertically polarized excitation laser beams yielded DCS which were remarkably similar, indicating that state-to-state scattering for this system is insensitive to probe beam polarization. Experimentally determined angular scattering distributions show primarily forward scattering for low-energy rotational states (j<7.5), with side- and back-scattering increasing with product angular momentum. The scattering results are compared and contrasted to results from earlier experimental investigations and to theoretical results from quantum close-coupling calculations based on ab initio coupled cluster CCSD(T) potential energy surfaces.
The development of effective classical potentials and the quantum statistical mechanical second virial coefficient of water
Authors: Schenter Gregory K.
Published: October 2002

The second virial coefficient of water is calculated at low temperature by considering full quantum statistical mechanical effects. At low enough temperatures experimental results are limited and molecular models can be used for accurate extrapolation. In doing so, one must separate deficiencies of the intermolecular potential from limitations of the simulation methodology such as the neglect of higher-order quantum corrections. Effective classical potentials may be used to understand the limitations of classical simulation. In this work we calculate the exact quantum statistical mechanical second virial coefficient and find that using a semiclassical form for the effective classical potential we are able to nearly reproduce the exact quantum statistical results. This approach provides a significant improvement to conventional first order expansions of the second virial coefficient.
Band structures of Ge and InAs: A 20 k.p model
Authors: Radhia S. Ben , Ridene S. , Boujdaria K. , Bouchriha H. , Fishman G.
Published: October 2002

The band structure of direct-band-gap semiconductor (InAs) and indirect-band-gap semiconductor (Ge) is described theoretically using a 20×20 k.p model and including far-level contribution (essentially the d levels). By using this model, we obtained a quantitatively correct description of the top of the valence band and the lowest two conduction bands both in terms of energetic positions and band curvatures. In particular, the k.p Hamiltonian parameters are adjusted such that the transverse mass of the germanium conduction band is equal to the experimental value of 0.081.
Morphological and biochemical analysis by atomic force microscopy and scanning near-field optical microscopy techniques of human keratinocytes (HaCaT) exposed to extremely low frequency 50 Hz magnetic field
Authors: Rieti Sabrina , Manni Vanessa , Lisi Antonella , Grimaldi Settimio , Generosi Renato , Luce Marco , Perfetti Paolo , Cricenti Antonio , Pozzi Deleana , Giuliani Livio
Published: October 2002

We studied the effect of the interaction of electromagnetic radiation with human keratinocytes (HaCaT), at low (50 Hz, 1 mT) frequency using both atomic force microscopy (AFM) and scanning near-field optical microscopy (SNOM) techniques. AFM analysis showed modifications in shape and morphology in exposed cells, while SNOM indirect immunofluorescence analysis revealed an increase of segregation of β4 integrin (an adhesion marker) in the cell membrane of the same cells, suggesting that a higher percentage of the exposed cells shows a modified pattern of this adhesion marker.
Electron-impact ionization of the methyl halides
Authors: Rejoub R. , Lindsay B. G. , Stebbings R. F.
Published: October 2002

Absolute partial and total cross sections for electron-impact ionization of CH3F, CH3Cl, CH3Br, and CH3I are reported for electron energies from threshold to 1000 eV. The product ions are mass analyzed using a time-of-flight mass spectrometer and detected with a position-sensitive detector whose output demonstrates that all product ion species are collected with equal efficiency irrespective of their initial kinetic energies. Data are presented for the production of CHnF+, CHnCl+, CHnBr+, CHnI+, CHn+, F+, Cl+, Br+, I+, and H+, where n=0–3. Data are also reported for production of H2+, H3+, and doubly charged species at 100 eV. The total cross section for each target is obtained as the sum of the partial cross sections. The overall uncertainty in the absolute cross sections for most of the singly charged ions is ±6%. It is observed that, although the Deutsch–Märk and the binary-encounter-Bethe theoretical formalisms are able to predict some features of the measured total cross sections, neither is consistently accurate. The simple ab initio method of Vallance et al. can apparently predict the value of the cross section maxima as well as the other more sophisticated approaches.
Gas phase infrared spectroscopy of cluster anions as a function of size: The effect of solvation on hydrogen-bonding in Br−⋅(HBr)1,2,3 clusters
Authors: Pivonka Nicholas L. , Kaposta Cristina , von Helden Gert , Meijer Gerard , Wöste Ludger , Neumark Daniel M. , Asmis Knut R.
Published: October 2002

The gas phase vibrational spectroscopy of Br−⋅(HBr)1,2,3 clusters has been studied between 6 and 16 μm (625 and 1700 cm−1) by multiphoton infrared photodissociation spectroscopy using the output of the free electron laser for infrared experiments. Infrared (IR) spectra were recorded by monitoring the mass-selected ion yield. In all three systems neutral HBr loss is found to be the dominant photofragmentation channel. BrHBr− exhibits a weak absorption band at 1558 cm−1 which is assigned to the overtone of the antisymmetric stretching mode ν3. A series of strong absorption bands was observed for Br−⋅(HBr)2 at energies in the 950–1450 cm−1 range. The Br−⋅(HBr)3 spectra reveal two absorption bands at 884 and 979 cm−1, which are assigned to two H-atom stretching modes. Evidence for the localization of the H atom and destruction of the symmetric BrHBr− hydrogen bond in the larger clusters is presented. Standard electronic structure calculations fail to reproduce the experimental IR spectra, indicating a breakdown of the harmonic approximation.