bluuebunny/crossref_metadata_2025 huggingface dataset:
Comparative leaf anatomy of Alpinia species (Zingiberaceae) in Malaysia
Authors: Talip Noraini , Hussin Khatijah Haji , Ibrahim Halijah
Published: March 2008

The leaf anatomy of 22 Alpinia species from the Malay Peninsular was investigated. Results show that a combination of characters such as outlines of midribs, petioles, leaf margins and their relative sizes in transverse sections as well as the presence of hypodermal fibres in the lamina, midribs and petioles can be used in the identification of species. All four species of subsection Allughas possess similar characters such as the presence of abaxial and adaxial fibres in the midrib and petioles and the absence of hypodermis in the lamina while the reverse is true for all species of subsection Catimbium. Alpinia conchigera and A. galanga appear to be closely related while A. oxymitra is distinct from all the species studied.
Edible Astraeus (Basidiomycota) from Thailand
Authors: Petcharat Vasun
Published: March 2008

Two edible species of Astraeus are widely collected for consumption and offered for sale in markets throughout Thailand. A. hygrometricus (Pers.) Morg. and A. thailandicus Petcharat are described herein, of which A. thailandicus Petcharat is further designated as a new species.
Three new species of Chascanum (Verbenaceae) and notes on the genus in the Horn of Africa region
Authors: Thulin Mats
Published: March 2008

The new species Chascanum mixtum, from evergreen bushland and rocky slopes in north‐western Somalia, C. elburense. from deciduous bushland mainly on sand in central Somalia, and C. glandulosum, from Acacia‐Commiphora bushland on sandy soil in north‐western Somalia, are described and illustrated. C. sessilifolium (Vatke) Moldenke is recircumscribed and neotypified with a specimen from the original type locality, and C. obovatum Sebsebe ssp. glaucum Sebsebe is placed in the synonymy of C. gillettli Moldenke.
Oryza coarctata: the name that best reflects the relationships of Porteresia coarctata (Poaceae: Oryzeae)
Authors: Lu Bao‐Rong , Ge Song
Published: March 2008

Oryza coarctata is a herbaceous species that serves as an important source of germplasm for salt tolerance in rice breeding. Despite biosystematic and phylogenetic studies showing that its closest relatives are other species of Oryza, many taxonomists continue to place it in the monospecific genus Porteresia because it is morphologically and ecologically distinct from other species of Ova. Such a treatment obscures the reality of its genetic similarities to Oryza. The authors strongly recommend returning this species to Oryza. This will have the added advantage of ensuring that all those reading about the species will immediately understand its importance to rice breeding.
Veronica longipedicellata (Scrophulariaceae), a new species from Iran
Authors: Mehwarz Shahryar Saeidi
Published: March 2008

Veronica longipedicellata is described and illustrated as a new species from an alpine area in north of Iran. The new species is compared with its allies and a close relationship is suggested with V. siaretensis.
Micromorphology of the achene epidermis of Kobresia (Cyperaceae) revealed by SEM and its taxonomic significance
Authors: Zhang Shu‐Ren
Published: March 2008

The taxonomy of the genus Kobresia is difficult and based on morphological characters. Achene micromorphology of the genus was studied with scanning electron microscopy (SEM), and its taxonomic significance evaluated. A total of 39 species and subspecies of Kobresia were included. The shape of epidermal cells of achenes is usually polygonal or rectangular. The anticlinal walls of the epidermal cells are mostly straight, rarely sinuous. Generally, a silica platform is formed on the inner periclinal wall of achene epidermal cell, and 1–3 silica bodies protrude from the middle of the platform. Sometimes, satellite silica bodies exist around the central bodies. The silica platform may be solid or perforated by pits. The micromorphological characters of the achene epidermis vary between different taxa. However, some closely related taxa show similarities. Therefore, the micromorphology of the achene epidermis of Kobresia is valuable in understanding the taxonomy at infraspecific, specific and supraspecific levels in the genus.
Stomatal frequency of Betula pubescens and Pinus sylvestris shows no proportional relationship with atmospheric CO2 concentration
Authors: Eide Wenche , Birks Hilary H.
Published: March 2008

We investigated the relationship between stomatal frequency and a range of atmospheric CO2 concentrations ([CO2]atm) in Betula pubescens and Pinus sylvestris, two important boreal trees in Scandinavia. If strong relationships exist, they can be used to reconstruct past [CO2]atm from stomatal frequency of fossil Betula and Pinus leaves. Responses of epidermal characters (stomatal density (SD), epidermal cell density (ED), stomatal index (SI)) to different CO2 concentrations were investigated utilising (1) the lower partial pressure of CO2 at increasing altitudes for B. pubescens, and in herbarium specimens of B. pubescens and P. sylvestris collected during the post‐industrial rise of [CO2]atm from c. 280 ppmv to c. 360 ppmv in 1997 and (2) concentrations (560 ppmv) and temperatures (3° summer) above present day in the CLIMEX greenhouse experiment. All the results show no clear relationship between SD or SI and [CO2] atm for either B. pubescens or P. sylvestris. Most likely there are stronger genetically and environmentally induced factors that affect the development of the leaves. Problems with collecting representative samples from herbarium specimens are discussed. Since the effects of changes in [CO2]atm cannot be statistically modelled, B. pubescens and P. sylvestris are not suitable for reconstructing past atmospheric CO2 concentrations from fossil leaves using stomatal density or stomatal index
Effects of simulated climate change on phenology and life history traits in Carex bigelowii
Authors: Stenström Anna , Jónsdóttir Ingibjörg S.
Published: March 2008

Climate change may have large effects on plants, especially in the Arctic. At two different sites, we studied the effects of enhanced temperature by using open‐top chambers (OTCs) on the clonal sedge Carex bigelowii, a common plant in arctic and alpine tundra. At the subarctic‐alpine site Latnjajaure, northern Sweden, overall flowering phenology was accelerated by open‐top chambers (OTCs) during the five years of treatment. For this protogynous population, male flower phenology accelerated more than female flower phenology, which resulted in an increased gender phase overlap. Sexual reproductive effort at the ramet‐level increased, both in male and female functions. Smut fungus incidence was not different among treatments, but a Dipteran seed predator attacked more ramets in the OTCs in one of five years. However, neither the fungus nor the seed predators affected plant growth or seed set measurably. Ramet‐level growth increased in the OTCs at Latnjajaure, but decreased in the OTCs at the maritime subarctic site Thingvellir, Iceland after three years of treatment. At Latnjajaure, the initial ramet‐ level responses were still evident after five years, while responses at the ramet population level disappeared: there was no difference in flowering frequency of ramets in the fifth year of the warming treatment. This is interpreted as either meristem limitation or internal resource depletion. At Thingvellir flowering frequency was unaffected by warming treatment, while ramet production decreased. Ramet production was unaffected by the treatment at Latnjajaure. These site differences in responses could be the consequences of differences in climate or site specific conditions. The trade‐off (negative correlation) between the number and size of vegetative offspring at Latnjajaure disappeared under enhanced temperatures (within the OTCs). This trade‐off was not apparent under the warmer conditions at Thingvellir.
Eryngium maritimum, biology of a plant at its northernmost localities
Authors: Curie Catrine M. , Stabbetorp Odd E. , Nordal Inger
Published: March 2008

The prospects for persistence of Eryngium maritimum in its northern distribution area was evaluated by studying historical data, matrix modelling, dispersal, seed germination and molecular variation. Historical data revealed a fragmented distribution of small populations with decrease in both population numbers and size during the last 150 years. Fruits of E. maritimum were found to have a relative low floating ability, making the prospects of long distance water dispersal more limited than would be expected from the world distribution of the species. Germination was found to be low (< 25 %). Elasticity matrices showed that survival of reproductive plants were more important than reproduction. High juvenile mortality and low germination activity emphasised the importance of rapid growth and survival. The population insurance against natural catastrophes and environmental stochasticity is suggested to be in a “root bank” of established individuals that are able to tolerate disturbances due to clonal reproduction and regrowth from root fragments. Isozyme electrophoresis revealed low molecular variation on a large geographical scale. The chromosome number is 2n = 16. A high degree of fixed heterozygosity suggests that the species is tetraploid with basic chromosome, number x = 4. The persistence prospects of E. maritimum in its northernmost distribution area are considered low considering the small population sizes, the low dispersal ability and low germination.
Efficacy of Autologous Blood Predonation
Authors: Mercuriali F. , Inghilleri G.
Published: March 2008

Allogeneic transfusion was traditionally considered an effective therapeutic intervention, but the fear of contracting blood‐borne infectious diseases has led to allogeneic blood transfusion now being regarded as an outcome to be avoided. Although the current blood supply is safer than ever owing to improved donor screening and testing1,2, allogeneic blood transfusion still carriesthe risks of causing immunological modifications3–6, and it is always possible that disease transmission will occur7–9. In addition, allogeneic blood transfusion should be avoided or at least limited in view of the increasing demand for blood productsdue to an aging population with a greater use of invasive procedures and major surgery (orthopedic. cardiovascular and cancer surgery) with high transfusion requirements.

Moreover, the introduction of stricter criteria for blood donor selection hasfurther decreased the availability of donor blood for transfusion and has increased the cost of procurement, storage and administration leading to the adoption of strategies to save this precious, limited and perishable resource.

The first strategies proposed were the strict observance of the M aximum Surgical Blood Order Schedule (M SBOS) for blood ordering in order to avoid wasting blood units10 and a reassessment of the indication for blood transfusion11. In addition, the use of donor blood in surgery can be substantially reduced by the introduction of autologousblood (AB) transfusion programs.
Cost‐effectiveness of Autologous Blood Predonation
Authors: Karger Ralf , Kretschmer Volker
Published: March 2008

The diminishing risks of allogeneic transfusion and the recognition of limited health care budgets cast doubt on the value of preoperative autologous blood donation (PABD). The criteria for estimating the alleged benefit of PABD are provided by the discipline of clinical epidemiology and are referred to as efficacy, effectiveness and efficiency. The efficacy of PABD can be assumed for colorectal cancer surgery, hip replacement and liver resection. PABD may be efficacious in most other elective surgical interventions with significant, anticipated blood loss. PABD is effective in these cases if there is no significant risk of donation or if a high statistical or individual risk of allogeneic transfusion isto be prevented. PABD is probably efficient, i.e. cost‐effective, if additional conditions such as low patient age, low production cost and/or high transfusion probability additionally apply. Production costs can be reduced by storing and delivering autologous blood as whole blood without harm to the patient.
Practical Limits of Acute Normovolemic Hemodilution Status and Future Prospects
Authors: Shander Aryeh
Published: March 2008

Acute normovolemic hemodilution (AN H) is an intraoperative blood conservation technique whereby fresh autologouswhole blood iswithdrawn from a patient during the induction of anesthesia or prior to the start of surgery and concurrently replaced with an acellular fluid resulting in red cell massdilution. The reduction in circulating red cells results in a reduction in the number of red cells lost due to surgical bleeding. Although some controversy exists regarding the efficacy and benefits of this procedure1,2, it has been utilized by numerouscliniciansfor several decades to avoid allogeneic blood transfusion in a wide variety of procedures that typically involve significant blood lossand subsequent blood replacement3–9. It may not be appropriate for patients undergoing procedures with a low risk for transfusion. Generally speaking, AN H is a safe and cost‐effective alternative to allogeneic blood transfusion10,11 that is currently underutilized5 and deservesto be more fully investigated and exploited.
Aerodynamic and Heat Flux Measurements in a Single-Stage Fully Cooled Turbine—Part II: Experimental Results
Authors: Haldeman C. W. , Mathison R. M. , Dunn M. G. , Southworth S. A. , Harral J. W. , Heltland G.
Published: March 2008

This paper presents measurements and the companion computational fluid dynamics (CFD) predictions for a fully cooled, high-work single-stage HP turbine operating in a short-duration blowdown rig. Part I of this paper (Haldeman, C. W., Mathison, R. M., Dunn, M. G., Southworth, S. A., Harral, J. W., and Heltland, G., 2008, ASME J. Turbomach., 130(2), p. 021015) presented the experimental approach, and Part II focuses on the results of the measurements and demonstrates how these results compare to predictions made using the Numeca FINE/Turbo CFD package. The measurements are presented in both time-averaged and time-accurate formats. The results include the heat transfer at multiple spans on the vane, blade, and rotor shroud as well as flow path measurements of total temperature and total pressure. Surface pressure measurements are available on the vane at midspan, and on the blade at 50% and 90% spans as well as the rotor shroud. In addition, temperature and pressure measurements obtained inside the coolant cavities of both the vanes and blades are presented. Time-averaged values for the surface pressure on the vane and blade are compared to steady CFD predictions. Additional comparisons will be made between the heat transfer on cooled blades and uncooled blades with identical surface geometry. This, along with measurements of adiabatic wall temperature, will provide a basis for analyzing the effectiveness of the film cooling scheme at a number of locations.
Control of Shroud Leakage Loss by Reducing Circumferential Mixing
Authors: Rosic Budimir , Denton John D.
Published: March 2008

Shroud leakage flow undergoes little change in the tangential velocity as it passes over the shroud. Mixing due to the difference in tangential velocity between the main stream flow and the leakage flow creates a significant proportion of the total loss associated with shroud leakage flow. The unturned leakage flow also causes negative incidence and intensifies the secondary flows in the downstream blade row. This paper describes the experimental results of a concept to turn the rotor shroud leakage flow in the direction of the main blade passage flow in order to reduce the aerodynamic mixing losses. A three-stage air model turbine with low aspect ratio blading was used in this study. A series of different stationary turning vane geometries placed into the rotor shroud exit cavity downstream of each rotor blade row was tested. A significant improvement in flow angle and loss in the downstream stator blade rows was measured together with an increase in turbine brake efficiency of 0.4 %.
Impulse Response Processing of Transient Heat Transfer Gauge Signals
Authors: Oldfield M. L. G.
Published: March 2008

A new, computationally efficient method is presented for processing transient thin-film heat transfer gauge signals. These gauges are widely used in gas turbine heat transfer research, where, historically, the desired experimental heat transfer flux signals, q, are derived from transient measured surface-temperature signals, T, using numerical approximations to the solutions of the linear differential equations relating the two. The new method uses known pairs of exact solutions, such as the T response due to a step in q, to derive a sampled approximation of the impulse response of the gauge system. This impulse response is then used as a finite impulse response digital filter to process the sampled T signal to derive the required sampled q signal. This is computationally efficient because the impulse response need only be derived once for each gauge for a given sample rate, but can be reused repeatedly, using optimized MATLAB filter routines and is highly accurate. The impulse response method can be used for most types of heat flux gauge. In fact, the method is universal for any linear measurement systems which can be described by linear differential equations where theoretical solution pairs exist between input and output. Examples using the new method to process turbomachinery heat flux signals are given.
Mycobacterium bovis
BCG Vaccine Strains Lack
narK2
and
narX
Induction and Exhibit Altered Phenotypes during Dormancy
Authors: Honaker Ryan W. , Stewart Amanda , Schittone Stephanie , Izzo Angelo , Klein Michèl R. , Voskuil Martin I.
Published: March 2008

Mycobacterium tuberculosis
is the causative agent of tuberculosis, a disease that affects one-third of the world's population. The sole extant vaccine for tuberculosis is the live attenuated
Mycobacterium bovis
bacillus Calmette-Guerin (BCG). We examined 13 representative BCG strains from around the world to ascertain their ability to express DosR-regulated dormancy antigens. These are known to be recognized by T cells of
M. tuberculosis
-infected individuals, especially those harboring latent infections. Differences in the expression of these antigens could be valuable for use as diagnostic markers to distinguish BCG vaccination from latent tuberculosis. We determined that all BCG strains were defective for the induction of two dormancy genes:
narK2
(Rv1737c) and
narX
(Rv1736c). NarK2 is known to be necessary for nitrate respiration during anaerobic dormancy. Analysis of the
narK2/X
promoter region revealed a base substitution mutation in all tested BCG strains and
M. bovis
in comparison to the
M. tuberculosis
sequence. We also show that nitrate reduction by BCG strains during dormancy was greatly reduced compared to
M. tuberculosis
and varied between tested strains. Several dormancy regulon transcriptional differences were also identified among the strains, as well as variation in their growth and survival. These findings demonstrate defects in DosR regulon expression during dormancy and phenotypic variation between commonly used BCG vaccine strains.
Involvement of Vesicle-Associated Membrane Protein 7 in Human Gastric Epithelial Cell Vacuolation Induced by
Helicobacter pylori
-Produced VacA
Authors: Mashima Hirosato , Suzuki Junko , Hirayama Toshiya , Yoshikumi Yukako , Ohno Hideki , Ohnishi Hirohide , Yasuda Hiroshi , Fujita Toshiro , Omata Masao
Published: March 2008

Helicobacter pylori
-produced cytotoxin VacA induces intracellular vacuolation. The VacA-induced vacuole is assumed to represent the pathological status of intracellular trafficking. The fusion mechanism of the endosomes requires the formation of a tight complex between the Q-SNAREs and the R-SNAREs. We recently reported that syntaxin 7, a family member of the Q-SNARE protein, is involved in VacA-induced vacuole formation. In order to further elucidate the molecular mechanism, we identified the participation of vesicle-associated membrane protein 7 (VAMP7) as a partner of syntaxin 7. Immunocytochemistry revealed endogenous VAMP7 to be localized to the vacuoles induced by VacA. A Northern blotting study demonstrated that VacA intoxication increased VAMP7 mRNA in a time-dependent manner. VAMP7 was coimmunoprecipitated with syntaxin 7, and the amounts of endogenous VAMP7 and syntaxin 7 bound to syntaxin 7 and VAMP7, respectively, increased in response to VacA. The down-regulation of VAMP7 using small interfering RNA inhibited VacA-induced vacuolation, and the transient transfection of dominant-negative mutant VAMP7, the N-terminal domain of VAMP7, also inhibited the vacuolation. We therefore conclude that R-SNARE VAMP7 plays an important role in VacA-induced vacuolation as a partner of Q-SNARE syntaxin 7.
Identification of a Novel Prophage-Like Gene Cluster Actively Expressed in Both Virulent and Avirulent Strains of
Leptospira interrogans
Serovar Lai
Authors: Qin Jin-Hong , Zhang Qing , Zhang Zhi-Ming , Zhong Yi , Yang Yang , Hu Bao-Yu , Zhao Guo-Ping , Guo Xiao-Kui
Published: March 2008

DNA microarray analysis was used to compare the differential gene expression profiles between
Leptospira interrogans
serovar Lai type strain 56601 and its corresponding attenuated strain IPAV. A 22-kb genomic island covering a cluster of 34 genes (i.e., genes LA0186 to LA0219) was actively expressed in both strains but concomitantly upregulated in strain 56601 in contrast to that of IPAV. Reverse transcription-PCR assays proved that the gene cluster comprised five transcripts. Gene annotation of this cluster revealed characteristics of a putative prophage-like remnant with at least 8 of 34 sequences encoding prophage-like proteins, of which the LA0195 protein is probably a putative prophage CI-like regulator. The transcription initiation activities of putative promoter-regulatory sequences of transcripts I, II, and III, all proximal to the LA0195 gene, were further analyzed in the
Escherichia coli
promoter probe vector pKK232-8 by assaying the reporter chloramphenicol acetyltransferase (CAT) activities. The strong promoter activities of both transcripts I and II indicated by the
E. coli
CAT assay were well correlated with the in vitro sequence-specific binding of the recombinant LA0195 protein to the corresponding promoter probes detected by the electrophoresis mobility shift assay. On the other hand, the promoter activity of transcript III was very low in
E. coli
and failed to show active binding to the LA0195 protein in vitro. These results suggested that the LA0195 protein is likely involved in the transcription of transcripts I and II. However, the identical complete DNA sequences of this prophage remnant from these two strains strongly suggests that possible regulatory factors or signal transduction systems residing outside of this region within the genome may be responsible for the differential expression profiling in these two strains.
New Approximate Analytical Formula for the Solute-Solvent Contact Distribution Function in an Infinitely Dilute Binary Hard-Sphere Mixture
Authors: Labík Stanislav , Smith William R.
Published: March 2008

A new analytical expression for the contact value of the solute-solvent pair distribution function of a binary hard-sphere mixture at infinite dilution is proposed, based on scaled-particle-theory-like arguments. For high solute-solvent diameter ratio it predicts perfect agreement with the simulation results.
NRF-1 is the major transcription factor regulating the expression of the human TOMM34 gene
Authors: Blesa José R. , Prieto-Ruiz Jesús A. , Abraham Beth A. , Harrison Bridget L. , Hegde Anita A. , Hernández-Yago José
Published: March 2008

The human TOMM34 gene encodes a cytosolic protein with chaperone-like activity that helps import some preproteins to the mitochondria by keeping them in an unfolded, import-compatible state. TOMM34 was found to be upregulated frequently in colorectal tumors, suggesting that it also has a role in the growth of cancer cells. In this context, TOMM34 is a potential target for novel anticancer drugs, and it might also be used in the diagnosis of colorectal cancer. Nuclear respiratory factors (NRFs) play an important role in governing the nuclear–mitochondrial interactions implicated in mitochondrial biogenesis. Our previous studies revealed that NRFs promote the expression of the major members of the mitochondrial transport machinery, TOMM70 and TOMM20. Here we report the existence of binding sites for NRF-1, Sp1, and NRF-2 in the 5′ region of the human TOMM34 gene. We determined the effects of mutations at these sites on promoter activity in HeLa S3 and A204 cells, in conjunction with chromatin immunoprecipitation experiments, electrophoretic mobility shift assays, and in vivo methylation analysis of the promoter region. We conclude that NRF-1 is the main transcription factor regulating the expression of TOMM34. Sp1 interacts with NRF-1 to stimulate the promoter's full activity.
A comparison of Hsp90α and Hsp90β interactions with cochaperones and substrates
Authors: Taherian Aliakbar , Krone Patrick H. , Ovsenek Nick
Published: March 2008

Hsp90 chaperone complexes function in assembly, folding, and activation of numerous substrates. The 2 vertebrate homologues encoded by the genes hsp90a and hsp90b are differentially expressed in embryonic and adult tissues and during stress; however, it is not known whether they possess identical functional activities in chaperone complexes. This question was addressed by examining potential differences between the Hsp90 isoforms with respect to both cochaperone and substrate interactions. Epitope-tagged proteins were expressed in mammalian cells or Xenopus oocytes and subjected to immunoprecipitation with an array of cochaperones. Both isoforms were shown to participate equally in multichaperone complexes, and no significant differences in cochaperone distribution were observed. The substrates Raf-1, HSF1, Cdc37, and MEK1 interacted with both Hsp90α and Hsp90β, and the relative patterns of these interactions were not affected by heat shock. The substrate kinases c-Src, CKIIB, A-raf, and Erk interacted with both isoforms; however, significantly more Hsp90α was recovered after heat shock. The data demonstrate that Hsp90α and Hsp90β exhibit similar interactions with cochaperones, but significantly different behaviors with respect to substrate interactions under stress conditions. These results reveal both functional similarities and key functional differences in the individual members of this protein family.
EXPERIMENTAL EVALUATION OF BSP PROGRAMMING LIBRARIES
Authors: KRUSCHE PETER
Published: March 2008

The model of bulk-synchronous parallel computation (BSP) helps to implement portable general purpose algorithms while maintaining predictable performance on different parallel computers. Nevertheless, when programming in ‘BSP style’, the running time of the implementation of an algorithm can be very dependent on the underlying communication library. In this study, an overview of existing approaches to practical BSP programming in C/C++ or Fortran is given and benchmarks were run for the two main BSP-like communication libraries, the Oxford BSP Toolset and PUB. Furthermore, a memory efficient matrix multiplication algorithm was implemented and used to compare their performance on different parallel computers and to evaluate the compliance with predictions by theoretical results.
A HYBRID SHARED MEMORY EXECUTION MODEL FOR A DATA PARALLEL LANGUAGE WITH I/O
Authors: GRELCK CLEMENS , KUTHE STEFFEN , SCHOLZ SVEN-BODO
Published: March 2008

We propose a novel execution model for the implicitly parallel execution of data parallel programs in the presence of general I/O operations. This model is called hybrid because it combines the advantages of the standard execution models fork/join and SPMD. Based on program analysis the hybrid model adapts itself to one or the other on the granularity of individual instructions. We outline compilation techniques that systematically derive the organization of parallel code from data flow characteristics aiming at the reduction of execution mode switches in general and synchronization/communication requirements in particular. Experiments based on a prototype implementation show the effectiveness of the hybrid execution model for reducing parallel overhead.
HIRONDML: FAIR THREADS MIGRATIONS FOR OBJECTIVE CAML
Authors: CHAILLOUX EMMANUEL , RAVET VIVIEN , VERLAGUET JULIEN
Published: March 2008

In this paper, we present HirondML, an Objective Caml library implementing migrating threads. Our library is based on a simplified implementation of the Fair Threads, a reactive threads system originally developed at INRIA. The Fair Threads scheduling policy is based on mixing cooperative and preemptive threads. We designed a thread migration system based on the cooperativeness of Fair Threads. To minimize data copying, we adopted an original rebinding policy distinguishing local variables, which are copied, from global variables, which are rebound when a migration takes place. Such a choice allows two styles of programming, by copy or by sharing. This will be illustrated by different distributed applications.
THE IMPACT OF DYNAMIC CHANNELS ON FUNCTIONAL TOPOLOGY SKELETONS
Authors: BERTHOLD JOST , LOOGEN RITA
Published: March 2008

Parallel functional programs with implicit communication often generate purely hierarchical communication topologies during execution: communication only happens between parent and child processes. Hence, messages between siblings must be passed via the parent causing inefficiencies that can be avoided by direct communication between arbitrary processes. The Eden parallel functional language provides dynamic channels to implement arbitrary communication topologies. This paper analyses the impact of dynamic channels on Eden's topology skeletons, i.e. skeletons which define process topologies such as rings, toroids, or hypercubes. We compare topology skeletons with and without dynamic channels with respect to runtime and communication. Our case studies confirm that dynamic channels decrease the number of messages by up to 50% and substantially reduce runtime. Detailed analyses of EdenTV (Eden trace viewer) execution profiles reveal a bottleneck in the root process when only hierarchical channel connections are used and a better distribution of communications with dynamic channels.
AUTOMATIC MAPPING OF ASSIST APPLICATIONS USING PROCESS ALGEBRA
Authors: ALDINUCCI MARCO , BENOIT ANNE
Published: March 2008

Grid technologies aim to harness the computational capabilities of widely distributed collections of computers. Due to the heterogeneous and dynamic nature of the set of grid resources, the programming and optimisation burden of a low level approach to grid computing is clearly unacceptable for large scale, complex applications. The development of grid applications can be simplified by using high-level programming environments. In the present work, we address the problem of the mapping of a high-level grid application onto the computational resources. In order to optimise the mapping of the application, we propose to automatically generate performance models from the application using the process algebra PEPA. We target applications written with the high-level environment ASSIST, since the use of such a structured environment allows us to automate the study of the application more effectively.
LOW POWER SYSTEM DESIGN BY COMBINING SOFTWARE PREFETCHING AND DYNAMIC VOLTAGE SCALING
Authors: PAMNANI SUMITKUMAR N. , AGARWAL DEEPAK N. , QU GANG , YEUNG DONALD
Published: March 2008

Performance-enhancement techniques improve CPU speed at the cost of other valuable system resources such as power and energy. Software prefetching is one such technique, tolerating memory latency for high performance. In this article, we quantitatively study this technique's impact on system performance and power/energy consumption. First, we demonstrate that software prefetching achieves an average of 36% performance improvement with 8% additional energy consumption and 69% higher power consumption on six memory-intensive benchmarks. Then we combine software prefetching with a (unrealistic) static voltage scaling technique to show that this performance gain can be converted to an average of 48% energy saving. This suggests that it is promising to build low power systems with techniques traditionally known for performance enhancement. We thus propose a practical online profiling based dynamic voltage scaling (DVS) algorithm. The algorithm monitors system's performance and adapts the voltage level accordingly to save energy while maintaining the observed system performance. Our proposed online profiling DVS algorithm achieves 38% energy saving without any significant performance loss.
OPTIMAL TRAINING DESIGN FOR MIMO–OFDM SYSTEMS UNDER SPATIALLY CORRELATED DOUBLY SELECTIVE FADING CHANNELS
Authors: YANG QINGHAI , KWAK KYUNG SUP
Published: March 2008

In this paper, we design an optimal training scheme for multi-input multi-output (MIMO) orthogonal frequency division multiplexing (OFDM) systems under spatially correlated time- and frequency- (doubly) selective fading channels. We first develop the optimal pilot symbols and placement of pilot clusters with respect to the minimum mean square error (MMSE) of the linear channel estimate. We then derive the optimal power allocation for pilot symbols in a two-water-level way: by maximizing the averaged capacity lower bound, how much power to be allocated for training is determined subject to the global water level (or the constraint of total transmit power); subsequently, pouring power to the pilot symbols with an approximately optimal water-filling scheme subject to the local water level (or the constraint of assigned power for training). In addition, for a particular OFDM size, the optimal number of pilot clusters is derived by maximizing the capacity lower bound and by minimizing the channel estimate's MMSE.
Modelling Regulatory Change V's Volume, of Trading Effects in HSIF and HSI Volatility
Authors: Gannon Gerard , Au-Yeung Siu Pang
Published: March 2008

In an earlier paper, we adopted a bi-variate BEKK–GARCH framework and employed a systematic approach to examine structural breaks in the Hang Seng Index and Index Futures market volatility. Switching dummy variables were included and tested in the variance equations to check for any structural changes in the autoregressive volatility structure due to the events that have taken place in the Hong Kong market surrounding the Asian markets crisis. In this paper, we include measures of daily trading volume from both markets in the estimation. Likelihood ratio tests indicate the switching dummy variables become insignificant and the GARCH effects diminish but remain significant. There is some evidence that the Sequential Arrival of Information Model (SIM) provides a platform to explain these market induced effects when volume of trade is accounted for.
A WAVELET BASED SIGNIFICANCE TEST FOR PERIODICITIES IN INDIAN MONSOON RAINFALL
Authors: AZAD SARITA , NARASIMHA R. , SETT S. K.
Published: March 2008

This paper is a sequel to a recent study of the authors' that uses a combination of multiresolution analysis (MRA) and classical Fourier spectral methods, to identify 17 peaks in the power spectral density of the Homogeneous Indian Monsoon (HIM) rainfall time series constructed in Ref. 1. Here we propose a new procedure for testing the statistical significance of these peaks. In this procedure, using MRA the stationary component of the rainfall time series is first identified. Then (partially) reconstructed time series are derived over each scale band in the stationary component. For each of these time series an appropriately colored reference spectrum is derived. The significance of the detected peaks is then determined using a χ2test against the reference spectra, which together represent a noise process spectrally close to rainfall. It is concluded that HIM rainfall exhibits 10 statistically significant periodicities at a confidence level of 99.9%.
Computation of rotation minimizing frames
Authors: Wang Wenping , Jüttler Bert , Zheng Dayue , Liu Yang
Published: March 2008

Due to its minimal twist, the rotation minimizing frame (RMF) is widely used in computer graphics, including sweep or blending surface modeling, motion design and control in computer animation and robotics, streamline visualization, and tool path planning in CAD/CAM. We present a novel simple and efficient method for accurate and stable computation of RMF of a curve in 3D. This method, called the
double reflection method
, uses two reflections to compute each frame from its preceding one to yield a sequence of frames to approximate an exact RMF. The double reflection method has the fourth order global approximation error, thus it is much more accurate than the two currently prevailing methods with the second order approximation error—the projection method by Klok and the rotation method by Bloomenthal, while all these methods have nearly the same per-frame computational cost. Furthermore, the double reflection method is much simpler and faster than using the standard fourth order Runge-Kutta method to integrate the defining ODE of the RMF, though they have the same accuracy. We also investigate further properties and extensions of the double reflection method, and discuss the variational principles in design moving frames with boundary conditions, based on RMF.
SOHO
Authors: Lessig Christian , Fiume Eugene
Published: March 2008

We propose the SOHO wavelet basis—the first spherical Haar wavelet basis that is both orthogonal and symmetric, making it particularly well suited for the approximation and processing of all-frequency signals on the sphere. We obtain the basis with a novel spherical subdivision scheme that defines a partition acting as the domain of the basis functions. Our construction refutes earlier claims doubting the existence of a basis that is both orthogonal and symmetric. Experimental results for the representation of spherical signals verify that the superior theoretical properties of the SOHO wavelet basis are also relevant in practice.
Radiance caching for participating media
Authors: Jarosz Wojciech , Donner Craig , Zwicker Matthias , Jensen Henrik Wann
Published: March 2008

In this article we present a novel radiance caching method for efficiently rendering participating media using Monte Carlo ray tracing. Our method handles all types of light scattering including anisotropic scattering, and it works in both homogeneous and heterogeneous media. A key contribution in the article is a technique for computing gradients of radiance evaluated in participating media. These gradients take the full path of the scattered light into account including the changing properties of the medium in the case of heterogeneous media. The gradients can be computed simultaneously with the inscattered radiance with negligible overhead. We compute gradients for single scattering from lights and surfaces and for multiple scattering, and we use a spherical harmonics representation in media with anisotropic scattering. Our second contribution is a new radiance caching scheme for participating media. This caching scheme uses the information in the radiance gradients to sparsely sample as well as interpolate radiance within the medium utilizing a novel, perceptually based error metric. Our method provides several orders of magnitude speedup compared to path tracing and produces higher quality results than volumetric photon mapping. Furthermore, it is view-driven and well suited for large scenes where methods such as photon mapping become costly.
Distributed Authentication of Program Integrity Verification in Wireless Sensor Networks
Authors: Chang Katharine , Shin Kang G.
Published: March 2008

Security in wireless sensor networks has become important as they are being developed and deployed for an increasing number of applications. The severe resource constraints in each sensor make it very challenging to secure sensor networks. Moreover, sensors are usually deployed in hostile and unattended environments and hence are susceptible to various attacks, including node capture, physical tampering, and manipulation of the sensor program. Park and Shin [2005] proposed a soft tamper-proofing scheme that verifies the integrity of the program in each sensor device, called the
program integrity verification
(PIV), in which sensors authenticate PIV servers (PIVSs) using centralized and trusted third-party entities, such as authentication servers (ASs). This article presents a distributed authentication protocol of PIVSs (DAPP) without requiring the commonly used ASs. DAPP uses the Blundo scheme [Blundo et al. 1992] for sensors and PIVSs to establish pairwise keys and for PIVSs to authenticate one another. We also present a protocol for PIVSs to cooperatively detect and revoke malicious PIVSs in the network. We implement and evaluate both DAPP and PIV on Mica2 Motes and laptops, showing that DAPP reduces the sensors' communication traffic in the network by more than 90% and the energy consumption on each sensor by up to 85%, as compared to the case of using a centralized AS for authenticating PIVSs. We also analyze the security of DAPP under various attack models, demonstrating its capability in dealing with diverse types of attacks.
Physiology of Growth
Authors: Rosenbloom Arlan L.
Published: March 2008

Human growth is a dynamic and complex process that begins with fertilization of the ovum and is completed with the fusion of epiphyses and metastases of the long bones marking the completion of adolescence. Growth occurs in phases with distinctive characteristics in terms of dominant influences from among genetic, environmental/nutritional, and hormonal factors and patterns. Prenatal growth is the most dramatic phase, achieving a velocity that is never again matched. It is predominantly under the influence of maternal size and nutritional status with little influence of parental genetic endowment. Insulin-like growth factors (IGFs) and insulin are critical, but thyroid hormone and growth hormone (GH) are not. Infancy is a period of rapidly changing growth rate, from 20 cm/year during the first few months to 10–12 cm/year by 1 year of age. This phase is greatly dependent on genetic endowment, with frequent adjustment to an appropriate percentile; it is also dependent on normal thyroid hormone and GH secretion and action (i.e. stimulation of IGF-I synthesis from the liver and promotion of chondrocyte differentiation and local secretion of IGF-I). Growth in the second year averages 10–13 cm/year, in the third year 7.5–10 cm/year and thereafter is stable at 5–6 cm/year, with continued dependency on normal secretion and action of thyroid hormone and GH. Relaxation of the suppression of the hypothalamic-gonadotropin axis with a slow increase in sex hormone production marks the onset of adolescence which is associated with a growth spurt resulting from increased insulin, GH, and IGF-I production, in addition to the sex hormone surge. Environmental influences on growth are reflected in secular trends over the past 150 years. A myriad of gene products acting on the growth plate have been described. In addition, delineation of pituitary differentiation factors and their genetic control, as well as identification of genes controlling multiple steps in key hormonal actions are increasing the understanding of the complex interplay of genetics, environment, and hormonal milieu in the growth process.
The New WHO Growth Standards
Authors: Ziegler Ekhard E. , Nelson Steven E.
Published: March 2008

The new World Health Organization (WHO) growth standards were created with the intention of producing globally applicable growth standards that describe the growth of children as it occurs under optimal nutritional conditions and in the absence of external constraints. In other words, it represents childhood growth as it should be. Children in six countries living in favorable circumstances provided data for the new charts. In addition, data for some subjects at the extremes of weight for height were excluded. The new WHO growth standards, not unexpectedly, differ from other growth charts in a number of ways. Because of the many differences, only a few general statements can be made. (1) During the first 6 months of life, WHO weight and length at all percentiles are larger than weight and length by any other chart. (2) During the second 6 months of life, and continuing through the 2nd year of life, WHO weight (but not length) is lower than weight by other charts. (3) Between 2 and 5 years of age, WHO weight tends to be at the lower end of the spectrum, especially at the lower percentiles, whereas Euro-Growth occupies the top end for weight at all percentiles. (4) Functional assessment shows that the WHO charts identify fewer 1- to 2-year-olds as underweight and more 2- to 5-year-olds as overweight than other charts.
Short and Tall Stature
Authors: Bramswig Jurgen H.
Published: March 2008

Short or tall stature is primarily a normal variation of height. It is part of the continuum of the normal Gaussian distribution curve which defines the lower and upper limit of normal as the 3rd and 97th percentile. Within this context it is very important to differentiate normal variations in height and growth from pathological conditions. Normal variations in height are familial and idiopathic short or tall stature. Normal variations in growth are diagnosed as constitutional acceleration or constitutional delay of growth and puberty and are observed on all percentiles. Patients with pathological conditions of height usually have a syndromal, skeletal or chromosomal disorders such as Russell-Silver or Marfan syndrome, achondroplasia, Ullrich-Turner or Klinefelter syndrome. Many of the disorders with short stature have intrauterine growth retardation. The (mean) final height does not necessarily follow the target height range, but reaches a height below or above the population 3rd or 97th percentile. Patients with pathological conditions of growth can have short, normal or tall stature. They have a reduced or increased growth rate caused by a wide variety of chronic organic or psychosomatic diseases. At present, treatment with growth hormone (GH) is available for patients with GH deficiency, Ullrich-Turner syndrome, chronic renal insufficiency, small for gestational age and Prader-Willi syndrome. The indication for GH treatment of idiopathic short stature is so far only approved in the USA. Adult height data indicate that patients with documented GH deficiency reach an adult height within their target height range. For all other indications a statistically significant improvement in adult height has been documented. In the long-term follow-up of these patients not only a statistically significant but also a clinically relevant improvement in adult height should be demonstrated. Depending on the results, some of the indications for GH therapy might have to be reconsidered.