bluuebunny/crossref_metadata_2025_split huggingface dataset:
Plasticity of muscle fibre number in seawater stages of Atlantic salmon in response to photoperiod manipulation
Authors: Johnston Ian A. , Manthri Sujatha , Smart Alisdair , Campbell Patrick , Nickell David , Alderson Richard 
Published: August 2003

SUMMARYAtlantic salmon (Salmo salar L.) were fed to satiety and reared from ∼60 g to 5000 g at ambient seawater temperatures. The effect of photoperiod manipulation on muscle growth was investigated from the start of the first sea winter. Continuous light treatment in winter/spring (1 November to 18 June) improved growth performance in fish, resulting in a 30% increase in mean body mass relative to the ambient photoperiod fish by 12 August, but had no effect on sexual maturation. Significant increases in body mass in the continuous light groups were observed after 126 days (P&lt;0.01). The number of fast muscle fibres per trunk cross-section was determined in a subset of the fish and was 28.5% higher in the continuous light(799×103) than the natural day length(644×103) groups after only 40 days, corresponding to the period of decreasing natural day length. Subsequent rates of fibre recruitment were similar between treatments. At the end of the fibre recruitment phase of growth (combined June and August samples), the maximum number of fast muscle fibres was 23% higher in fish from the cages receiving continuous light(881×103±32×103; N=19) than in the ambient photoperiod cages(717×103±15×103; N=20)(P&lt;0.001). Continuous light treatment was associated with a shift in the distribution of fibre diameters, reflecting the altered patterns of fibre recruitment. However, the mean rate of fibre hypertrophy showed no consistent difference between treatments. There was a linear relationship between the myonuclear content of isolated single fibres and fibre diameter. On average, there were 27% more myonuclei in 150 μm-diameter fibres in the continuous light (3118 myonuclei cm-1) than the ambient photoperiod(2448 myonuclei cm-1) fish. After 40 days, continuous light treatment resulted in a transient increase in the density of myogenic progenitor cells, identified using a c-met antibody, to a level 70% above that of fish exposed to natural light. It is suggested that short days inhibited the proliferation of myogenic progenitor cells and that this was overcome by transferring fish to continuous light, causing an increase in the number of times the myogenic precursor cells divided and/or a decrease in cell cycle time. The net increase in myogenic progenitor cells resulted in proportional increases in the number and myonuclear content of fibres. The subsequent hypertrophy of these additional fibres can explain the delayed increase in body mass observed with continuous light treatment.
Time course of the response of mitochondria from oxidative muscle during thermal acclimation of rainbow trout, Oncorhynchus mykiss
Authors: Bouchard Patrice , Guderley Helga 
Published: August 2003

SUMMARY
The time course of changes in the properties of mitochondria from oxidative muscle of rainbow trout was examined during warm (15°C) and cold (5°C)acclimation. Mitochondrial oxidative capacities showed a biphasic response during thermal acclimation: at a given assay temperature, capacities first increased and then decreased during warm acclimation and showed the inverse pattern during cold acclimation. This was most apparent for maximal rates of state 3 oxygen consumption expressed per mg mitochondrial protein. Rates expressed per nmol ADP-ATP translocase (ANT) showed this pattern during cold acclimation. A biphasic pattern was also apparent for state 4 and oligomycin-inhibited (state 4ol) rates of oxygen uptake expressed per mg protein. Changes in states 4 and 4ol were smaller during cold than warm acclimation. Warm acclimation reduced the proportion of cytochrome c oxidase and citrate synthase needed during mitochondrial substrate oxidation. Phospholipid concentrations per mg mitochondrial protein changed little with thermal acclimation. Mitochondrial properties changed more quickly during warm than cold acclimation. While the biochemical modifications during thermal acclimation may eventually compensate for the thermal change,compensation did not occur at its onset. Rather, the initial changes of mitochondrial oxidative capacity in response to temperature change accentuated the functional impact of the thermal change, and prolonged exposure to the new temperature was required to attain a degree of thermal compensation.
Intestinal water absorption through aquaporin 1 expressed in the apical membrane of mucosal epithelial cells in seawater-adapted Japanese eel
Authors: Aoki Mayumi , Kaneko Toyoji , Katoh Fumi , Hasegawa Sanae , Tsutsui Naoaki , Aida Katsumi 
Published: August 2003

SUMMARYTo elucidate the mechanisms associated with water absorption in the intestine, we compared drinking and intestinal water absorption in freshwater-and seawater-adapted Japanese eels, and investigated a possible involvement of aquaporin (AQP) in the absorption of water in the intestine. Seawater eels ingested more water than freshwater eels, the drinking rate being 0.02 ml kg-1 h-1 in fresh water and 0.82 ml kg-1h-1 in sea water. In intestinal sacs prepared from freshwater and seawater eels, water absorption increased in time- and hydrostatic pressure-dependent manners. The water absorption rates were greater in seawater sacs than in freshwater sacs, and also greater in the posterior intestine than in the anterior. In view of the enhanced water permeability in the intestine of seawater eel, we cloned two cDNAs encoding AQP from the seawater eel intestine, and identified two eel homologues (S-AQP and L-AQP) of mammalian AQP1. S-AQP and L-AQP possessed the same amino acid sequence, except that one amino acid was lacking in S-AQP and two amino acids were substituted. Eel AQP1 was expressed predominantly in the intestine, and the expression levels were higher in seawater eel than in freshwater eel. Immunocytochemical studies revealed intense AQP1 immunoreaction in the apical surface of columnar epithelial cells in seawater eel, in which the immunoreaction was stronger in the posterior intestine than in the anterior. In contrast, the immunoreaction was faint in the freshwater eel intestine. Preferential localization of AQP1 in the apical membrane of epithelial cells in the posterior intestine of seawater eel indicates that this region of the intestine is responsible for water absorption, and that AQP1 may act as a water entry site in the epithelial cells.
A marine diatom-derived aldehyde induces apoptosis in copepod and sea urchin embryos
Authors: Romano Giovanna , Russo Gian Luigi , Buttino Isabella , Ianora Adrianna , Miralto Antonio 
Published: August 2003

SUMMARY
The diatom-derived aldehyde 2-trans-4-trans-decadienal(DD) was tested as an apoptogenic inducer in both copepod and sea urchin embryos, using terminal-deoxynucleotidyl-transferase-mediated dUTP nick-end labelling (TUNEL), DNA fragmentation profiling (laddering) and an assay for caspase-3 activity. DD induced TUNEL positivity and DNA laddering, but not caspase-like activation, in copepod embryos spawned by females fed for 10-15 days the diatom diet Thalassiosira rotula Meunier (in vivo),or when newly spawned eggs were exposed for 1 h to 5 μg ml-1 DD(in vitro). To our knowledge, this is the first time that evidence for an apoptotic process in copepods has been obtained by cytochemical (TUNEL)and biochemical (DNA fragmentation) approaches. The absence of caspase-like activity in copepod embryos suggests that caspase-independent programmed cell death occurs in these organisms. In sea urchin embryos, DD induced apoptosis and also activated a caspase-3-like protease. The saturated aldehyde decanal induced apoptosis at higher concentrations and after a longer incubation period than DD, indicating that α,β-unsaturation of the molecule,coupled with the aldehyde group, is responsible for the greater biological activity of DD. Since diatoms are an important food source for marine herbivores such as copepods and sea urchins, these findings may help explain why unsaturated aldehydes often induce reproductive failure, with important ecological consequences at the population level.
Hormonal control of swimbladder sonic muscle dimorphism in the Lusitanian toadfish Halobatrachus didactylus
Authors: Modesto Teresa , Canário Adelino V. M. 
Published: August 2003

SUMMARY
The swimbladder and associated sonic muscle of the Lusitanian toadfish Halobatrachus didactylus increase in size throughout life and are,respectively, 25% and 30% larger in type I (nest-holder) males than females,which may generate sexual differences in sound production. Sexual dimorphism in swimbladder is also evident in the morphological features of sonic muscle fibers. During the breeding season, type I males have smaller myofibril contracting zones surrounded by larger sarcoplasm areas compared with females,possibly an adaptation to speed and fatigue resistance for the production of long mating calls. Type II (floater) males show characteristics that are intermediate, but statistically not significantly different, between type I males and females. Six weeks after castration and androgen (testosterone and 11-ketotestosterone) replacement in type I and type II males there were no alterations either in swimbladder mass or fiber morphology. However,17β-estradiol induced a significant decrease in swimbladder mass and sarcoplasm area/myofibril area ratio. Six months after castration there was a clear reduction in the seasonal swimbladder hypertrophy in males and induction of sonic fiber morphological characteristics that resemble those occurring in females (low sarcoplasm area/myofibril area ratio). These results suggest that testicular factors are required to initiate sonic muscle hypertrophy and type I sonic fiber phenotype in H. didactylus, but a specific involvement of androgens has not been completely clarified.
A hydrodynamic topographic map in the midbrain of goldfishCarassius auratus
Authors: Plachta Dennis T. T. , Hanke Wolf , Bleckmann Horst 
Published: August 2003

SUMMARYSensory systems often consist of several parallel pathways. Within each pathway, sensory information may be processed in topographically arranged maps or in maps derived by neuronal computation. Parallel pathways have so far not been described in the central lateral line system of teleost fish at levels higher than the medulla, and evidence for midbrain lateral line maps in fish is still weak. We found two classes of units with different response patterns in the central lateral line nucleus in the torus semicircularis of the goldfish Carassius auratus. Units of one class responded to a passing sphere and to the wake caused by that sphere with excitation. Units of the second class also responded to the moving sphere. However, these units did not respond to the wake behind the sphere. Hydrodynamic information received by class two units was topographically organized in the torus semicircularis of goldfish in that anterior body areas projected to rostral midbrain and posterior body areas to caudal midbrain. Units that responded only to the passing sphere were on average located more ventrally in the lateral TS than the units that responded exclusively to a vibrating sphere.
Waterborne iron acquisition by a freshwater teleost fish, zebrafishDanio rerio
Authors: Bury Nicolas R. , Grosell Martin 
Published: August 2003

SUMMARYWaterborne iron accumulation by the gills of the zebrafish Danio rerio was assessed in ion-poor water. Branchial iron uptake, which comprises both the iron that has entered the gill cells and iron that is strongly bound to the epithelia, has high- and low-affinity components. At low nominal [Fe] (&lt;40 nmol l-1) the high-affinity component demonstrated saturation kinetics, with an apparent Km of 5.9 nmol l-1 Fe and Vmax of 2.1 pmol g-1 h-1. Over a range of higher nominal [Fe] (40-200 nmol l-1), branchial uptake was linear. In the presence of 2μmol l-1 of the reducing agent dithiothreitol (DTT), branchial iron accumulation was significantly enhanced at [Fe]&gt;15 nmol l-1. The proton pump inhibitor bafilomycin A significantly reduced iron uptake in the presence of DTT. On the basis of these observations we conclude that branchial iron uptake at low [Fe] shows characteristics similar to those of other iron-transporting epithelia, coupling an apical membrane ferric reductase to a Fe2+/H+ symporter. Zebrafish branchial iron transport at 18.6 nmol l-1 was inhibited by 200 nmol l-1 Cd2+. But, unlike other Fe2+/H+ symporters, iron uptake was not affected by other divalent metals (Co2+, Ni2+, Pb2+,Cu2+, Zn2+ and Mn2+). Zebrafish loaded with 59Fe from the water showed a loss of 7.9 pmol Fe g-1body mass over the first day and a further loss of 5.7 pmol Fe g-1body mass over the following 28 days. The depuration kinetics followed a two-component exponential model; for the short-lived component, t1/2=0.31 days, and for the long-lived component, t1/2=13.2 days. The daily iron loss by zebrafish can be compensated by iron uptake at exceedingly low water iron concentrations(uptake rate at 1.625 nmol l-1 Fe=0.425 pmol g-1h-1), demonstrating that uptake of iron from the water is potentially an important source of this nutritive metal in freshwater teleost fish.
An early role for theDrosophila melanogastermale seminal protein Acp36DE in female sperm storage
Authors: Qazi Margaret C. Bloch , Wolfner Mariana F. 
Published: August 2003

SUMMARYFemale sperm storage is an essential component of reproduction in many animals. In insects, female sperm storage affects fecundity, sperm competition/preference and receptivity to re-mating. Female sperm storage consists of several stages, including sperm entry into the sperm storage organs (SSOs), maintenance within the SSOs and exit from the SSOs. The Drosophila melanogaster male seminal protein Acp36DE is essential for female sperm storage. Acp36DE associates with sperm and localizes to specific regions of the female reproductive tract, including the SSOs. We determined the stage of sperm storage at which Acp36DE acts by comparing the timing of initial sperm entry into storage as well as the rates of sperm accumulation and release from the SSOs in the presence or absence of Acp36DE. Acp36DE accelerates sperm accumulation into storage but does not mediate the entry of the first sperm into storage. This finding also demonstrates that the initial stage of sperm storage consists of multiple steps. Acp36DE enters the SSOs before sperm, and its residence within the SSOs does not require sperm. We propose that once sperm storage has initiated, Acp36DE acts as a guidance factor helping subsequent sperm move into storage, a corral concentrating sperm around the SSO entrances and/or a trigger for responses within the female that accelerate storage of sperm.
Compactness of Linear Aggregation Controlled by Molecular Selective Binding of Bridged Bis(β-cyclodextrin)s
Authors: Liu Yu , Wang Hao , Zhang Heng-Yi , Wang Li-Hua , Song Yun 
Published: August 2003

Abstract
Studies on linear aggregation prepared by inclusion complexation of bridged bis(β-cyclodextrin)s and calix[4]arene derivatives provide a simple method to control linear aggregation compactness by molecular recognition.
Analysis of Metallo‐Supramolecular Systems Using Single‐Molecule Force Spectroscopy
Authors: Kudera M. , Eschbaumer C. , Gaub H.E. , Schubert U.S. 
Published: August 2003

AbstractSingle‐molecule force spectroscopy has been used for the investigation of the rupture behavior of individual metallo‐supramolecular systems. For this purpose, a specifically designed unsymmetrical α,ω‐functionalized poly(ethylene oxide) has been employed for mono‐termination with a terpyridine ligand and subsequently for the attachment onto atomic force microscopy (AFM) tips and microscope slide substrates. Metallo‐supramolecular complexes were formed by the use of ruthenium(III)–ruthenium(II) chemistry. Vertical stretching with the AFM cantilever ruptured the coordinative bonds. The rupture force of individual bisterpyridine ruthenium(II) complexes was determined to be 95 pN at a force loading rate of 1 nN s–1. Simultaneous rupturing of multiple parallel metallo‐supramolecular bonds was also observed. Monte Carlo simulations corroborated the experimental observations. The presented results lay the basis for the application of such metallo‐supramolecular systems in advanced functional nanomaterials.
The Origin of Green Emission in Polyfluorene‐Based Conjugated Polymers: On‐Chain Defect Fluorescence
Authors: Romaner L. , Pogantsch A. , Scandiucci de Freitas P. , Scherf U. , Gaal M. , Zojer E. , List E.J.W. 
Published: August 2003

AbstractThe low emission band at 2.2–2.3 eV in polyfluorene‐based conjugated materials is studied by various spectroscopic methods on defined copolymers of 9–9′‐difarnesyl‐fluorene with 9‐fluorenone, which can be seen as a model compound for degraded polyfluorenes. Absorption, electroluminescence, and photoluminescence in the film (temperature‐dependent) and solution (room temperature) reveal the optical properties of this low‐energy emission band emerging in polyfluorene‐type polymers upon degradation. All the experimental evidence presented yield direct evidence against excimer or aggregate formation as the primary source of the low‐energy emission band. Instead keto defect sites can be shown to be responsible for the emissive defect.
Well‐Defined Fullerene Nanowire Arrays
Authors: Guo Y.‐G. , Li C.‐J. , Wan L.‐J. , Chen D.‐M. , Wang C.‐R. , Bai C.‐L. , Wang Y.‐G. 
Published: August 2003

AbstractFullerene nanowire arrays with well‐defined size and length have been prepared by a controllable technique. Fullerene molecules such as C60 are introduced into the pores of anodic aluminum oxide (AAO) templates under a direct current (DC) electric field and polymerized in the pores. Structure analysis shows that the C60 nanowires are mainly polycrystalline, and a rhombohedral polymeric phase is observed in their vibration spectra. The electrical conductivity of so‐prepared nanowire arrays show a semiconducting behavior. The ability to fabricate the fullerene nanowire arrays with controlled structures represents an important step toward the development of chemical sensors and nanoscale electronic devices based on fullerenes.
General Synthesis of Single‐Crystal Tungstate Nanorods/Nanowires: A Facile, Low‐Temperature Solution Approach
Authors: Yu S.‐H. , Liu B. , Mo M.‐S. , Huang J.‐H. , Liu X.‐M. , Qian Y.‐T. 
Published: August 2003

AbstractThe general large‐scale synthesis of a family of single‐crystalline transition metal tungstate nanorods/nanowires is easily realized by a hydrothermal crystallization technique under mild conditions using cheap and simple inorganic salts as precursors. Uniform tungstate nanorods/nanowires such as MWO4 (M = Zn, Mn, Fe), Bi2WO6, Ag2WO4, and Ag2W2O7 with diameters of 20–40 nm, lengths of up to micrometers, and controlled aspect ratios can be readily obtained by hydrothermal transformation and recrystallization of amorphous particulates. This novel and efficient pathway toward various kinds of related low‐dimensional tungstate nanocrystals under mild conditions could open new opportunities for further investigating the novel properties of tungstate materials.
Fully Reversible Homogeneous and Heterogeneous Li Storage in RuO2 with High Capacity
Authors: Balaya P. , Li H. , Kienle L. , Maier J. 
Published: August 2003

AbstractIn this paper, we report that Li can be stored in RuO2 with an unusually high coulombic efficiency. The process involves three electrochemical steps: i) formation of a Ru/Li2O nanocomposite, ii) formation of a Li‐containing surface film, and iii) interfacial deposition of Li within the Ru/Li2O matrix. Corresponding to the storage of 5.6 mole of Li ions per mole of RuO2, a high capacity of 1130 mAh g–1 is achieved. Furthermore, virtually all inserted Li ions can be extracted, corresponding to a nearly 100 % coulombic efficiency at the first cycle. Achieving a complete reversibility for such a Li storage system through complex heterogeneous solid‐state electrochemical reactions is possible because of the formation of nanoscale Ru/Li2O during Li insertion and nano‐RuO2 during Li extraction, in addition to the favorable transport properties of RuO2 itself.
Powder‐Based Ceramic Meso‐ and Microscale Fabrication Processes
Authors: Heule M. , Vuillemin S. , Gauckler L.J. 
Published: August 2003

AbstractProcessing techniques are reviewed that allow the introduction of ceramic components made from powders into microelectromechanical systems (MEMS). Ceramics have several advantages over other materials also in microsystems, e.g., heat resistance, hardness, corrosion resistivity, or functional properties. The range of available materials in microfabrication technology is being increased beyond those deposited by thin‐film technology. Top–down approaches like mechanical and laser‐based direct writing processes, ink‐jet printing, microextrusion, and lithography‐based methods are presented. They are complemented by some more fundamental work in the field of bottom–up synthesis of micro‐ and nanoscaled ceramic materials.
Adverse work outcomes and events attributed to asthma
Authors: Mancuso Carol A. , Rincon Melina , Charlson Mary E. 
Published: August 2003

AbstractBackgroundAsthma is a chronic condition that has been linked to lower employment rates, job effectiveness, productivity and increased absenteeism. The objectives of this study were to assess the impact of asthma on work function, workplace events, and career.MethodsOne hundred ninety‐six patients in an urban practice completed standardized major and minor life events scales and rated whether adverse work events were caused by asthma.ResultsThirty‐eight percent of the patients had either changed jobs, work hours, or work duties, and 65% had taken days off because of asthma. In multivariate analyses, less education, not wanting to work, more comorbidity, prior use of oral corticosteroids, and current use of oral beta agonists and methylxanthines (P ≤ 0.05 for all comparisons) were associated with these outcomes. Also, currently working patients were more likely to be using inhaled corticosteroids (P = 0.018). Thirty‐nine percent believed asthma had adversely affected their career by causing them to: not pursue a desired career; not get promoted due to absenteeism; change to a worse job; and be perceived as incapable of more responsible assignments. Seven percent had a negative work event in the preceding year that they attributed to asthma, including job loss and unfavorable interactions with co‐workers.ConclusionsPatients attribute daily and long‐term adverse work outcomes to asthma. Asthma severity and demographic and occupational characteristics were associated with adverse occurrences. Am. J. Ind. Med. 44:236–245, 2003. © 2003 Wiley‐Liss, Inc.