bluuebunny/crossref_metadata_2025_split huggingface dataset:
Ontogenetic allometry in the locomotor skeleton of specialized half‐bounding mammals
Authors: Lammers Andrew R. , German Rebecca Z. 
Published: November 2002

AbstractSpecialization for a locomotor behaviour may affect limb bone morphology throughout ontogeny. Ontogenetic development of the limb skeletons of two mammalian species, which are behaviourally specialized for the half‐bounding gait (Chinchilla lanigera and Oryctolagus cuniculus), were compared to two similarly‐sized species which are not specialized for half‐bounding (Rattus norvegicus and Monodelphis domestica). Limb bone lengths and anteroposterior diameters (mediolateral diameters for the radius and metacarpal) were measured from radiographs taken throughout the ontogeny of each species. Body mass was also measured repeatedly during growth. Bone measurements were regressed against body mass, as well as forelimb bone length vs serially homologous hindlimb bone length, bone length vs total limb length and bone length vs width. Similar comparisons were made among adults of each species using ratios. Although there were many significant differences among species, overall there were few consistent differences in adult scaling ratios or ontogenetic allometry slopes between specialized and generalized groups. Adult specialized half‐bounders had significantly narrower tibiae and metatarsals than the gait‐generalized runners. Specialized half‐bounders usually had similar slopes for hindlimb length vs width ontogenetic comparisons, but the non‐specialized species did not group together. However, there were two patterns that occurred among all four species: (1) hindlimb bone lengths nearly always grew faster than the serially homologous forelimb bone lengths in all species; (2) proximal elements usually increased in length proportionally faster than distal elements. In conclusion, small mammals may share strong developmental constraints that govern their relative growth rates. It is also likely that there are different selective pressures on juveniles and adults, but that these selective pressures may not be different between specialized and unspecialized runners during ontogeny.
Sperm storage in the simultaneously hermaphroditic land snail Arianta arbustorum
Authors: Bojat Nenad C. , Haase Martin 
Published: November 2002

AbstractMany simultaneously hermaphroditic land snails have sperm digesting glands and multiple sperm storage organs, which it is suggested give the sperm recipient control over the number of sperm accepted and hence fertilization. In order to increase fertilization success, the sperm donor should manipulate the recipient to accept more sperm, especially so in situations of sperm competition. In helicid snails, the love dart optionally pushed into the partner's body during courtship, has been suggested to be such a manipulative tool. We investigated the influence of the sperm donor's size, sperm volume transferred and dart pushing on the volume of allosperm stored by the recipient in virgin Arianta arbustorum. In addition, we were interested in sperm storage patterns within the spermathecae. Fifty per cent of the snails already possessed a dart and tried to use it. However, most of them missed the partner. The main tubule always contained more than 50% of the total amount of sperm stored. Otherwise sperm storage patterns were very variable. The volume of sperm stored was significantly influenced only by the number of spermathecal tubules. The significance of spermathecal morphology for sperm storage needs further exploration.
Morphological variation provides a method of estimating thermal niche in hatchlings of the squid Loligo forbesi (Mollusca: Cephalopoda)
Authors: Gowland F. C. , Boyle P. R. , Noble L. R. 
Published: November 2002

AbstractMorphological variation was investigated in hatchling squid Loligo forbesi Steenstrup 1856 reared at three constant temperatures. Twenty‐seven morphometric and chromatophore characters were measured on 180 hatchlings. Hatchlings were randomly sampled from 15 egg strings, representing six egg mops and spread across two spawning seasons. Size at hatching varied inversely with temperature and was significantly reduced at 16°C (mean mantle length 2.87±0.04 se mm) compared to 8°C (3.26±0.03 se mm). Hatchlings reared at 12°C developed significantly narrower mantles than those reared at 8 or 16°C. Principal components, stepwise elimination and canonical variates analyses performed using all 27 measured characters revealed that nine characters were vital in discriminating between temperature groups. Canonical structure values associated with eight of these characters were used in the construction of a canonical equation. By measuring the same eight characters on field‐sampled L. forbesi, this equation can be used to estimate mean thermal history of wild hatchlings. Field‐application of the techniques developed during the present study may allow assessment of realized thermal niche in a mobile marine invertebrate.
Skeletal growth of the deep‐sea hexactinellid sponge Euplectella oweni, and host selection by the symbiotic shrimp Spongicola japonica (Crustacea: Decapoda: Spongicolidae)
Authors: Saito Tomomi , Uchida Itaru , Takeda Masatsune 
Published: November 2002

AbstractAspects of the skeletal growth of the deep‐sea hexactinellid sponge Euplectella oweni Herklots and Marshall, and host size and type selection by the symbiotic shrimp Spongicola japonica Kubo were investigated using field‐collected material. Two phases, flexible and stiff, were observed in the framework of the sponges. In the flexible sponges, the circular, longitudinal and oblique systems of the skeletal beams that constitute the principal framework were not fused to each other, and the parietal ledges running circularly, or sometimes obliquely, on the wall were not developed. The skeletal wall was fragile in texture, readily torn by any external force. The wall was much sturdier in the stiff sponges, in which the systems of the skeletal beams were coarse, fused to each other to make the principal framework tough in texture, and pareital ledges developed so as to reinforce the sponge wall. The flexible phase is mainly seen in smaller and younger sponges, while the stiff phase was seen in the larger (or dead) ones. Almost all the solitary and young pairs of shrimps were collected from flexible sponges.
Stabilimentum variations in Argiope versicolor (Araneae: Araneidae) from Singapore
Authors: Seah Wee Khee , Li Daiqin 
Published: November 2002

AbstractMany orb‐web building spiders add conspicuous, white silk decorations termed stabilimenta onto the central portion of the webs. Stabilimenta are known to vary greatly in form and quantity from species to species, and also within a species. In the present study, stabilimentum variations in form and quantity are described, and the factors influencing stabilimentum variations in Argiope versicolor from Singapore, in both the field and the laboratory, are examined. Our results from field survey and laboratory experiments show that: (1) the form and occurrence of stabilimenta varied with developmental stage of spiders: A. versicolor juveniles (body length: < 0.6 cm) built disc‐like (discoid) stabilimenta while adults spun cross‐like (cruciform) stabilimenta; (2) the quantity of stabilimenta (percentage of stabilimentum area covering the web to the web area) decreased with increasing web size and spider size; (3) light intensity affected the density and percentage cover of stabilimentum on the web: A. versicolor tend to build more and denser stabilimenta in dim conditions than in bright surroundings; (4) well‐fed A. versicolor adults added more stabilimenta than starved spiders. These findings suggest that A. versicolor may adjust the frequency and quantity of stabilimenta to suit multiple functions, specifying the circumstances under which to use each function (conditional stabilimentum‐building strategies).
A fresh look at binary search trees
Authors: HINZE RALF 
Published: November 2002

Binary search trees are old hat, aren't they? Search trees are routinely covered
in introductory computer science classes and they are widely used in functional
programming courses to illustrate the benefits of algebraic data types and pattern
matching. And indeed, the operation of insertion enjoys a succinct and elegant functional formulation. Figure 1 contains the six-liner given in the language Haskell 98.Alas, both succinctness and elegance are lost when it comes to implementing the
dual operation of deletion, also shown in figure 1. Two additional helper functions
are required causing the code size to double in comparison with insertion.
A Perfectly Normal Abnormality: German Foreign Policy after Kosovo and Afghanistan
Authors: U. Berger Thomas 
Published: November 2002

For decades Japan and the Federal Republic of Germany have gone to extraordinary lengths to cultivate as low a profile as possible on defense and national security policy matters. However, since the Gulf War, the Federal Republic has come under growing pressure from its allies to assume a greater international security role. Slowly, reluctantly it has acceded to these demands, albeit at the expense of considerable internal angst and turmoil. At the same time, German decision makers have sought to preserve as much as possible the old approach to security policy. Consequently, the long-standing German norms eschewing the use of military force have been gradually displaced, although not wholly replaced, by norms of multilateralism. Rather than a dramatic break with the past, the Federal Republic's actions in Kosovo and Afghanistan can be seen as the culmination of a series of incremental steps that had begun a decade ago.To substantiate these claims this paper will first briefly outline the origins of the Cold German national security practices and the peculiar constellation of domestic and international factors that shaped them. It will then consider in what ways these factors have both changed, and not changed, since the end of the Cold War and sketch the trajectory along which German defense and national security policies have evolved since 1991. Finally, the paper briefly examines the Federal Republic's response to the Kosovo and Afghan crises before offering some general conclusions about the likely future evolution of German security policy.
On properties of update sequences
based on causal rejection
Authors: EITER THOMAS , FINK MICHAEL , SABBATINI GIULIANA , TOMPITS HANS 
Published: November 2002

In this paper, we consider an approach to update nonmonotonic knowledge bases represented
as extended logic programs under the answer set semantics. In this approach, new information
is incorporated into the current knowledge base subject to a causal rejection principle, which
enforces that, in case of conflicts between rules, more recent rules are preferred and older
rules are overridden. Such a rejection principle is also exploited in other approaches to update
logic programs, notably in the method of dynamic logic programming, due to Alferes et al.One of the central issues of this paper is a thorough analysis of various properties
of the current approach, in order to get a better understanding of the inherent causal
rejection principle. For this purpose, we review postulates and principles for update and
revision operators which have been proposed in the area of theory change and nonmonotonic
reasoning. Moreover, some new properties for approaches to updating logic programs are
considered as well. Like related update approaches, the current semantics does not incorporate
a notion of minimality of change, so we consider refinements of the semantics in this direction.
We also investigate the relationship of our approach to others in more detail. In particular,
we show that the current approach is semantically equivalent to inheritance programs, which
have been independently defined by Buccafurri et al., and that it coincides with certain classes
of dynamic logic programs. In view of this analysis, most of our results about properties of the
causal rejection principle apply to each of these approaches as well. Finally, we also deal with
computational issues. Besides a discussion on the computational complexity of our approach,
we outline how the update semantics and its refinements can be directly implemented on
top of existing logic programming systems. In the present case, we implemented the update
approach using the logic programming system DLV.
Analysis of Differential Expression of Barley ESTs during Cold Acclimatization Using Microarray Technology
Authors: Faccioli P. , Lagonigro M. S. , de Cecco L. , Stanca A. M. , Alberici R. , Terzi V. 
Published: November 2002

Abstract: Genomics adds a new dimension to genetic analysis, shifting the focus from the study of a single gene to the whole genome. We have successfully applied the genomics approach based on microarray to the study of genes involved in barley responses to cold stress. About 900 EST clones from barley were obtained from a cDNA library of cold acclimatized leaves of cv. Nure and arrayed, and gene expression analysis done on cold acclimatized vs. control plants. The system allowed for reliable detection of differences in mRNA expression levels, and was confirmed by the finding that numerous previously reported cold‐related genes were differentially expressed in treated and untreated plants when evaluated in our arrays. The expression profiles of a sample of genes analysed by the array were confirmed by quantitative RT‐PCR.Previously, identification of novel plant genes was achieved considering a few genes at a time; now many genes can be found as up‐ or down‐regulated based on a one step procedure. Many of the genes we found to be up‐ or down‐regulated do not have an assigned function. This includes 15 of the 78 up‐regulated and 8 of the 45 down‐regulated clones. Our results add new genes to the group of cold‐regulated genes and provide the opportunity to better understand the complex mechanism of stress tolerance.
Leaf Gas Exchange Characteristics in Relation to Leaf Canopy Position of Myrica faya in its Native Environment (Tenerife, Canary Islands)
Authors: González‐Rodríguez A. M. , Morales D. , Jiménez M. S. 
Published: November 2002

Abstract: Diurnal courses of gas exchange were measured throughout one year in fully expanded current‐year leaves in the uppermost canopy (sun leaves, 18 m above ground) and in the lower canopy (shade leaves, 12 m above ground) of Myrica faya Ait., a dominant component of the Canarian laurel forest in Tenerife, Canary Islands, Spain. M. faya showed large differences between sun and shade leaves in gas exchange characteristics (about 50 % of maximum carbon assimilation rate (Amax) reduction in shade leaves, but this reduction can be higher on specific days) that were modulated by strong light attenuation and high leaf area index (LAI) of the stand. This species presented low Amax, about 10 μmol m‐2 s‐1, high maximum transpiration (E, 8 mmol m‐2 s‐1) and stomatal conductance (gs, 750 mmol m‐2 s‐1) and very low instantaneous water use efficiency (WUE, mean maximum 1.1 mmol mol‐1) and A/gs (mean maximum 23.5 μmol mol‐1). M. faya responded to high air vapour pressure deficit (VPD), decreasing its gs but maintaining relatively high values of A and E during the studied period. Stomatal response to VPD showed a higher sensitivity than its congeners, M. cerifera, and Laurus azorica, tree species co‐occurring in the Canarian laurel forest. In general, all these gas exchange characteristics lead us to consider this species more similar to subtropical plants of humid regions than to species of the Mediterranean region.
Plume–Ridge Interaction: a Geochemical Perspective from the Reykjanes Ridge
Authors: MURTON BRAMLEY J. , TAYLOR REX N. , THIRLWALL MATTHEW F. 
Published: November 2002

Abstract
Plume–ridge interaction in the Reykjanes Ridge and Iceland region is graphically demonstrated by several V-shaped ridges surrounding the spreading axis, indicating mantle flow away from Iceland. It also has significant geochemical effects. Regionally, incompatible element concentrations increase northwards coinciding with decreasing depth and increasing crustal thickness, depth of melting and proximity to Iceland. Major and trace element data show that isolated magma bodies feed individual volcanic systems along the ridge. Fractionation within these systems increases towards 60–61°N, where it coincides with the intersection of a V-shaped ridge, thicker crust and more abundant seamounts. Trace element, Nd and Sr isotopic data reveal dynamic melting and mixing within a southward-thinning, heterogeneous mantle wedge beneath the Reykjanes Ridge. Melting is variable and locally enhanced at 58°N, 59°N, 60°N and 61°N. A total of six mantle components are identified. Some are specific to Iceland whereas others are found only beneath the ridge axis. The geographical distribution of these components reflects their origin within the deep upper and lower mantle and subsequent translation by plume outflow along the entire length of the ridge.
Drug Susceptibilities of Yeast Cells Are Affected by Membrane Lipid Composition
Authors: Mukhopadhyay Kasturi , Kohli Avmeet , Prasad Rajendra 
Published: November 2002

ABSTRACT

In the present study we have exploited isogenic
erg
mutants of
Saccharomyces cerevisiae
to examine the contribution of an altered lipid environment on drug susceptibilities of yeast cells. It is observed that
erg
mutants, which possess high levels of membrane fluidity, were hypersensitive to the drugs tested, i.e., cycloheximide (CYH),
o
-phenanthroline, sulfomethuron methyl, 4-nitroquinoline oxide, and methotrexate. Most of the
erg
mutants except mutant
erg4
were, however, resistant to fluconazole (FLC). By using the fluorophore rhodamine-6G and radiolabeled FLC to monitor the passive diffusion, it was observed that
erg
mutant cells elicited enhanced diffusion. The addition of a membrane fluidizer, benzyl alcohol (BA), to
S. cerevisiae
wild-type cells led to enhanced membrane fluidity. However, a 10 to 12% increase in BA-induced membrane fluidity did not alter the drug susceptibilities of the
S. cerevisiae
wild-type cells. The enhanced diffusion observed in
erg
mutants did not seem to be solely responsible for the observed hypersensitivity of
erg
mutants. In order to ascertain the functioning of drug extrusion pumps encoding the genes
CDR1
(ATP-binding cassette family) and
CaMDR1
(MFS family) of
Candida albicans
in a different lipid environment, they were independently expressed in an
S. cerevisiae erg
mutant background. While the fold change in drug resistance mediated by
CaMDR1
remained the same or increased in
erg
mutants, susceptibility to FLC and CYH mediated by
CDR1
was increased (decrease in fold resistance). Our results demonstrate that between the two drug extrusion pumps, Cdr1p appeared to be more adversely affected by the fluctuations in the membrane lipid environment (particularly to ergosterol). By using 6-[(7-nitrobenz-2-oxa-1,3-diazol-4-yl) amino-hexanoyl] sphingosyl phosphocholine (a fluorescent analogue of sphingomyelin), a close interaction between membrane ergosterol and sphingomyelin which appears to be disrupted in
erg
mutants is demonstrated. Taken together it appears that multidrug resistance in yeast is closely linked to the status of membrane lipids, wherein the overall drug susceptibility phenotype of a cell appears to be an interplay among drug diffusion, extrusion pumps, and the membrane lipid environment.
In Vivo Efficacy of Continuous Infusion versus Intermittent Dosing of Linezolid Compared to Vancomycin in a Methicillin-Resistant
Staphylococcus aureus
Rabbit Endocarditis Model
Authors: Jacqueline Cédric , Batard Eric , Perez Lucia , Boutoille David , Hamel Antoine , Caillon Jocelyne , Kergueris Marie-France , Potel Gilles , Bugnon Denis 
Published: November 2002

ABSTRACT

Linezolid is the first drug issued from the oxazolidinones, a novel class of antimicrobial agents with potent activity against gram-positive pathogens. A rabbit endocarditis model was used to compare the in vivo activities of different linezolid regimens mimicking intermittent dosing of 10 mg/kg of body weight every 12 h for 5 days or continuous (constant-rate) infusion of a daily dose of 20 mg/kg (for 5 days) or 40 mg/kg (for 3 and 5 days) and the activities of intermittent dosing and continuous infusion of vancomycin (for 5 days). The in vivo activities of these regimens were tested against three strains of methicillin-resistant
Staphylococcus aureus
. A human-like pharmacokinetic simulation was used for linezolid in order to improve the extrapolation of the results to human therapy. All linezolid regimens significantly reduced the numbers of
S. aureus
cells in aortic valve vegetations compared to the numbers in the control groups. Linezolid intermittent dosing had an in vivo bacteriostatic effect. Switching from intermittent dosing to continuous infusion (at the same dose) led to in vivo bactericidal activity, with a decrease of at least 3 log
10
CFU/g of vegetation compared to the counts for the controls. After 5 days of treatment, continuous infusion of linezolid (corresponding to a daily dose of 40 mg/kg in humans) seemed to be at least as effective as vancomycin against the three strains. No resistant variant was isolated from the vegetations during any of the treatments. These data suggest that continuous infusion of linezolid could be an appropriate alternative to the use of glycopeptides for the treatment of severe methicillin-resistant
S. aureus
infections.
Effect of a Single Percutaneous Abscess Drainage Puncture and Imipenem Therapy, Alone or in Combination, in Treatment of Mixed-Infection Abscesses in Mice
Authors: Stearne Lorna E. T. , Buijk Steven L. , Mouton Johan W. , Gyssens Inge C. 
Published: November 2002

ABSTRACTThe importance of supplementary imipenem therapy after a single percutaneous abscess drainage puncture was studied in a mouse model of established mixed-infection abscesses. Animals were treated for 3 days with daily dosing regimens of 384 to 1,536 mg/kg of body weight that took into account the short half-life of this antibiotic in mice. Imipenem therapy in conjunction with abscess drainage was significantly better than drainage alone in reducing theEscherichia coliandBacteroides fragiliscounts in the mixed infections. Furthermore, the killing ofB. fragilisby the combination of imipenem therapy and abscess drainage was significantly better than that by imipenem treatment alone. The maximum reductions inE. coliandB. fragiliscounts were 1.1 and 2.2 log10CFU/abscess, respectively. In contrast, the in vitro activity of imipenem was significantly better (maximum reduction, ≥6.2 log10CFU/ml) against mixed cultures of the same strains even when bacterial numbers similar to those found in the abscesses were used. Comparable in vivo activity was achieved only when treatment was started 30 min before inoculation (reduction for both strains, ≥6.1 log10CFU/abscess), but this killing was significantly diminished if the start of treatment was delayed until ≥12 h after inoculation. Imipenem concentrations in abscess tissue reached levels above the MIC forE. colifor >60% of the dosing interval. Possible reasons for the reduced activity of imipenem in vivo are discussed, and we conclude that standard susceptibility tests overestimate the efficacy of this antibiotic against the organisms present in these abscesses.