bluuebunny/crossref_metadata_2025_split huggingface dataset:
Development and steroid regulation of RFamide immunoreactivity in antennal-lobe neurons of the sphinx mothManduca sexta
Authors: Schachtner Joachim , Trosowski Björn , D'Hanis Wolfgang , Stubner Stephan , Homberg Uwe 
Published: June 2004

SUMMARYDuring metamorphosis, the insect nervous system undergoes considerable remodeling: new neurons are integrated while larval neurons are remodeled or eliminated. To understand further the mechanisms involved in transforming larval to adult tissue we have mapped the metamorphic changes in a particularly well established brain area, the antennal lobe of the sphinx moth Manduca sexta, using an antiserum recognizing RFamide-related neuropeptides. Five types of RFamide-immunoreactive (ir) neurons could be distinguished in the antennal lobe, based on morphology and developmental appearance. Four cell types (types II–V, each consisting of one or two cells) showed RFamide immunostaining in the larva that persisted into metamorphosis. By contrast, the most prominent group (type I), a mixed population of local and projection neurons consisting of about 60 neurons in the adult antennal lobe, acquired immunostaining in a two-step process during metamorphosis. In a first step, from 5 to 7 days after pupal ecdysis, the number of labeled neurons reached about 25. In a second step, starting about 4 days later, the number of RFamide-ir neurons increased within 6 days to about 60. This two-step process parallels the rise and fall of the developmental hormone 20-hydroxyecdysone (20E) in the hemolymph. Artificially shifting the 20E peak to an earlier developmental time point resulted in the precocious appearance of RFamide immunostaining and led to premature formation of glomeruli. Prolonging high 20E concentrations to stages when the hormone titer starts to decline had no effect on the second increase of immunostained cell numbers. These results support the idea that the rise in 20E, which occurs after pupal ecdysis, plays a role in the first phase of RFamide expression and in glomeruli formation in the developing antennal lobes. The role of 20E in the second phase of RFamide expression is less clear, but increased cell numbers showing RFamide-ir do not appear to be a consequence of the declining levels in 20E that occur during adult development.
Mechanical energy in toddler gait A trade-off between economy and stability?
Authors: Hallemans Ann , Aerts Peter , Otten Bert , De Deyn Peter P. , De Clercq Dirk 
Published: June 2004

SUMMARYMechanical energy expenditure was investigated in children who are just learning to walk and compared with adult mechanical energy expenditure during walking. First, we determined whether the inverted pendulum (IP) mechanism of energy exchange was present in toddlers. It seems that new walkers partially make use of this energy saving mechanism, but it is less efficient than in adults. The reduced recovery values (R=40% at optimal speeds in toddlers compared to 70% in adults) can be explained by their low self-selected walking speed in combination with their tossing gait (large vertical oscillations of the body) and by the observation that during as much as 25–50% of the gait cycle kinetic and potential energy are oscillating in-phase.The second step was to calculate positive external mechanical work(Wext). Since the IP mechanism is less efficient in toddlers, more mass-specific positive work has to be performed to lift and accelerate the centre of mass than in adults walking at the same speed, even when differences in body size are taken into account.The amount of positive internal work (Wint,k) necessary to move the body segments relative to the centre of mass was the third parameter we calculated. In toddlers Wint,k is largely determined by the kinetic energy of the lower limb. Compared to adults,toddlers have to perform less mass-specific work per unit distance to accelerate the body segments since the upper body is kept relatively stiff during walking and there is no arm swing.Apart from work performed on the centre of mass and work performed to move the body segments relative to the centre of mass, when walking some work is also performed during double contact as both legs are pushing against each other. Two methods were used to calculate this amount of work, both leading to the same conclusions. Mass-specific work during double contact is small in toddlers compared to adults because of their low walking speed.Finally the total amount of mechanical work performed in toddlers was compared to the work production observed in adults. Wextseems to be the major determinant for total mechanical energy expenditure. At intermediate froude numbers work production is comparable between adults and toddlers, but at low and high froude numbers Wtotincreases due to the steep increases in Wext. Despite the fact that mechanical work requirements in toddler gait are underestimated if work during double contact is not taken into account, it is not a major determinant of the energy cost of walking.
Spectral properties of myoelectric signals from different motor units in the leg extensor muscles
Authors: Wakeling James M. , Rozitis Antra I. 
Published: June 2004

SUMMARYMyoelectric signals measured using intramuscular electromyograms (EMGs) in animals have shown that faster motor units generate higher frequencies in their power spectra. However, evidence to relate myoelectric frequency and motor unit type from the surface electromyograms typically measured from man have remained elusive. The purpose of this study was to determine if spectral properties from surface EMG could be related to the different motor units in the muscles of the leg extensors in man. Reflex experiments (both tendon tap and electrically stimulated) and graded isometric contractions were used to generate muscle contractions with different patterns of motor unit recruitment. EMG was recorded from the vastus lateralis and medialis, rectus femoris, medial and lateral gastrocnemius and soleus muscles. The EMGs were resolved into their intensities in time–frequency space using wavelet techniques. The intensity spectra were calculated for the reflex responses and for different contractile forces. The spectra were compared using principle component analyses and ANCOVA. Electrical stimulation can result in preferentially faster motor units being recruited, and in this study resulted in higher myoelectric frequencies than for the stretch reflex. During ramped contractions the motor units are recruited in an orderly fashion from slow to fast. As the faster motor units were recruited then higher frequency components appeared within the myoelectric intensity spectra. For all muscles tested there were significant correlations between the stage in contraction and the EMG frequency. Both approaches demonstrated higher frequency components in the myoelectric spectra when the faster motor units could be assumed to be active.
Pre-receptor profile of sensory images and primary afferent neuronal representation in the mormyrid electrosensory system
Authors: Gómez Leonel , Budelli Ruben , Grant Kirsty , Caputi Angel A. 
Published: June 2004

SUMMARY
Afferent responses to the fish's own electric organ discharge were explored in the electrosensory lobe of the mormyrid fish Gnathonemus petersii. In order to understand the neural encoding of natural sensory images,responses were examined while objects of different conductivities were placed at different positions along the skin of the fish, i.e. at different points within, and also outside, peripheral receptive fields. The presence of an object in the fish's self-generated electric field produces local modulation of transcutaneous current density. Measurement of the local electric organ discharge shows that object images formed at the electroreceptive sensory surface have an opposing center-surround, `Mexican hat' profile. This is a pre-receptor phenomenon intrinsic to the physical nature of the sensory stimulus that takes place prior to neural lateral inhibition and is independent of such central inhibition.
Stimulus intensity is encoded in the latency and number of action potentials in the response of primary afferent fibers. It is also reflected in changes in the amplitude and area of extracellular field potentials recorded in the deep granular layer of the electrosensory lobe. Since the object image consists of a redistribution of current density over the receptive surface,its presence is coded by change in the activity of receptors over an area much larger than the skin surface facing the object. We conclude that each receptor encodes information coming from the whole scene in a manner that may seem ambiguous when seen from a single point and that, in order to extract specific object features, the brain must process the electric image represented over the whole sensory surface.
Hypoxia tolerance and preconditioning are not additive in the trout(Oncorhynchus mykiss) heart
Authors: Gamperl A. Kurt , Faust Heather A. , Dougher Bekah , Rodnick Kenneth J. 
Published: June 2004

SUMMARYResearch has shown that the trout heart is normally hypoxia-sensitive, and that it can be preconditioned. However, we have identified a group of rainbow trout Oncorhynchus mykiss that shows a surprising degree of myocardial hypoxia tolerance. In this study, we used in situ hearts from these fish as a comparative model to examine whether the cardioprotective effects afforded by hypoxic adaptation and preconditioning are additive. In situ trout hearts were exposed to severe hypoxia (perfusate PO2 5–10 mmHg) in the absence and presence of a transient hypoxic pre-exposure (preconditioning). The four groups studied were: (1) control (no hypoxia); (2) 5 min of severe hypoxia;(3) 30 min of severe hypoxia; and (4) 5 min of severe hypoxia (hypoxic preconditioning) followed 20 min later by 30 min of severe hypoxia. 30 min of severe hypoxia significantly decreased maximum cardiac output and stroke volume by 15–30%. However, hypoxic preconditioning failed to confer any protection against post-hypoxic myocardial dysfunction. This work shows that the protection afforded by inherent myocardial hypoxia tolerance and preconditioning are not additive in this population of trout, and strongly suggests that the relationship between hypoxic adaptation and preconditioning in fishes resembles that of the neonatal/immature, not adult, mammalian heart. Further, our results (1) indicate that stretch (volume loading) and chronic exposure to low levels of adrenaline (15 nmol l-1) do not confer any protection against hypoxia-related myocardial dysfunction in this population, and (2) validate the use of the in situ trout heart as a comparative model for studying aspects of myocardial hypoxia tolerance and preconditioning in vertebrates.
One-step Route to Single-crystal γ-Mn3O4 Nanorods in Alcohol–Water System
Authors: Yang Baojun , Hu Hanmei , Li Cun , Yang Xiaogang , Li Qiaowei , Qian Yitai 
Published: June 2004

Abstract
A one-step low-temperature alcohol–water thermal route has been developed to synthesize single-crystal γ-Mn3O4 nanorods with diameters of 50–120 nm, and lengths of up to several tens micrometers. high-resolution transmission electron microscopic observations show that the axial direction of the as-prepared nanorods is perpendicular to the normal direction of the (101) lattice planes of the tetragonal γ-Mn3O4.
Novel Surface-modified Molecularly Imprinted Polymer Focused on the Removal of Interference in Environmental Water Samples
Authors: Watabe Yoshiyuki , Hosoya Ken , Tanaka Nobuo , Kubo Takuya , Kondo Takuya , Morita Masatosi 
Published: June 2004

Abstract
Uniformly sized molecularly imprinted polymers (MIPs) for bisphenol A (BPA) with immobilized intervals of functional monomers utilizing 4,4′-methylenebisphenol as a pseudo template have been prepared. The MIPs through surface modification for the removal of interference showed significant selectivity for BPA retention and removal performance for interference in actual environmental water samples as the HPLC stationary phase compared to those of ordinary MIPs. These MIPs were employed as pretreatment media of column switching HPLC.
Nitration of Aromatic Compounds with Nitric Acid Catalyzed by Ionic Liquids
Authors: Qiao Kun , Yokoyama Chiaki 
Published: June 2004

Abstract
Nitration of simple aromatic compounds with 62% nitric acid is successfully carried out under solvent-free condition in a biphasic mode in the presence of the Brønsted acidic ionic liquids; the only by-product is water and ionic liquids are capable of being reused without any separation.
Arrangement of Ferritin Molecules on a Gold Disk Array Fabricated on Highly Ordered Anodic Porous Alumina Substrate
Authors: Masuda Hideki , Hogi Hiromi , Nishio Kazuyuki , Matsumoto Futoshi 
Published: June 2004

Abstract
An ordered array of ferritin, in which the arrangement of ferritin coincided with the arrangement of Au disks, was prepared on Au nanodisk arrays fabricated on a highly ordered anodic porous alumina substrate. Selective adsorption of ferritin onto the Au disk by controlling the modification time and ferritin concentration in the modification solution was confirmed by scanning electron microscopy.
Dissolution of Phthalocyanines in Dense Carbon Dioxide and Its Solvatochromic Behavior under Pressureized Conditions
Authors: Kawanami Hajime , Ikushima Yutaka , Kobayashi Nagao 
Published: June 2004

Abstract
Metallophthalocyanines having alkoxy groups have been found to dissolve in dense carbon dioxide in the presence of small amount of cosolvent such as methanol or pyridine. The pressure dependence of the absorption maximum of these phthalocyanines can be used as an indicator for measuring solvent polarity.
Synthesis and Optical Properties of Novel Nickel Disulfide Dendritic Nanostructures
Authors: Luo Rui , Sun Xia , Yan Lifeng , Chen Wenming 
Published: June 2004

Abstract
Dendritic NiS2 nanostructures are successfully synthesized for the first time via the reaction between NiCl2·6H2O and CS2 in poly(MMA-co-EA) gel using γ irradiation.
Moderne Volumenvisualisierung (Modern Volume Visualization)
Authors: Pfister Hanspeter 
Published: June 2004

Zusammenfassung
Die Volumenvisualisierung hat sich in den letzten zehn Jahren zu einer unentbehrlichen Visualisierungstechnik für viele Anwendungsbereiche entwickelt. In diesem Beitrag präsentieren wir einen Überblick über moderne, hardwarebeschleunigte Methoden zur Visualisierung von Volumendaten: Raycasting, Texture-Slicing, Shear-Warp-Rendering und Splatting.
Medizinische Visualisierung: Methoden und Anwendungen in der Ausbildung und Therapieplanung (Visualization: Methods and Applications in Therapy Planning and Education)
Authors: Preim Bernhard , Peitgen Heinz-Otto 
Published: June 2004

Zusammenfassung
Die medizinische Visualisierung befasst sich mit der Darstellung und Exploration radiologischer Bilddatensätze. Zu den grundlegenden Aufgaben gehören die Exploration der patientenindividuellen Bilddaten, die Visualisierung baumartiger Strukturen, die Hervorhebung von Objekten, die quantitative Analyse sowie die virtuelle Resektion. Lösungsmöglichkeiten für diese Aufgaben werden anhand konkreter Fallbeispiele beschrieben.
Logik und Informatik (Logic and Computer Science)
Authors: Kreutzer Stephan , Schweikardt Nicole 
Published: June 2004

Zusammenfassung
Als eine ihrer wichtigsten theoretischen Grundlagen hat die Logik Bedeutung für fast alle Bereiche der Informatik. Wir wollen diese hier anhand der Bereiche Datenbanken, automatische Verifikation und Komplexitätstheorie erläutern und dabei die Fragestellungen und Ergebnisse unserer beiden Dissertationen vorstellen.
Rundheitsmessungen mit einem Diodenlaserinterferometer (Roundness Measurements with a Diode Laser Interferometer)
Authors: Burgarth Volker , Meiners-Hagen Karl , Abou-Zeid Ahmed 
Published: June 2004

Abstract
Stand der Technik bei Rundheitsmessungen sind zurzeit mechanisch antastende Systeme. Unter bestimmten Umständen kann die mechanische Antastung zu Abrieb oder Deformation des Prüflings führen. Mit einem neu entwickelten Interferometer und einem kommerziellen Formmessgerät wurden Rundheitsmessungen an verschiedenen Prüflingen berührungslos durchgeführt. Die Funktionsfähigkeit der interferometrischen Messmethode konnte für einen weiten Bereich von Rundheitsabweichung, Material und Oberflächenstruktur gezeigt werden. Zum Vergleich wurden die Prüflinge auch mit einem mechanischen Taster ausgemessen.
Simulationskammer für ein modifiziertes Senarmont-Verfahren (Simulation Chamber for a Modified Senarmont Measurement Method)
Authors: Kaufmann Siegfried , Schache Hannes , Beyer Horst 
Published: June 2004

Abstract
Automatische, berührungslose und Online-Messungen des Gangunterschiedes und der Doppelbrechung an laufenden, optisch anisotropen Proben (Fasern, Folien) können auch bei modernen Herstellungsverfahren falschfarbenfrei und schnell bei sehr hohen Gangunterschieden durchgeführt werden. Dazu dient ein von uns entwickeltes modifiziertes Senarmont-Mess-Verfahren. Die trotzdem noch auftretenden Probleme werden mit einer Simulationskammer untersucht, wobei insbesondere die Auswirkungen des Verdrehungswinkels bei Folien, die Wirkung des abgewinkelten Strahlenganges bei der berührungslosen Messung an Fasern und die Auswirkungen von Lageschwankungen der Fasern auf den Gangunterschied und die Doppelbrechung getestet werden.
Growth, Survival, and Body Composition of Juvenile Atlantic Sturgeon Fed Five Commercial Diets under Hatchery Conditions
Authors: King Kim 
Published: June 2004

Abstract
Growth and survival were evaluated for 1 year in juvenile Atlantic sturgeon Acipenser oxyrinchus (mean weight, 164.9 g) held at seasonal temperatures (6.4–16.9°C) and fed five commercially available feeds: Biokyowa (BK; control), Zeigler sturgeon (ZSD), Integral sturgeon (ISD), Atlantic salmon (ASD2–30), and Government Ration trout diet (GR7–30). During the 365-d study, the overall growth performance of the juvenile Atlantic sturgeon fed ZSD, ASD2–30, and ISD was equal to that of the fish fed the BK diet and superior to that of the fish fed GR7–30 (P &lt; 0.05). The final mean weight was highest for the fish fed ZSD and lowest for the fish fed GR7–30. The fish fed the ZSD and BK diets were the only groups to continue gaining weight in winter (6.4–9.7°C). The differences in growth may be related to dietary levels or ingredient quality. Body moisture, body protein, and body fat were affected by diet type and seasonal temperature. Among the diets tested, ZSD and ASD2–30 produced the greatest growth at the lowest cost in juvenile Atlantic sturgeon held at ambient seasonal temperatures.
Adult Recoveries of Volitionally and Forced-Released Juvenile Coho Salmon
Authors: Appleby Andrew E , Tipping Jack M , Seidel Paul R 
Published: June 2004

Abstract
Test groups of coded-wire-tagged yearling coho salmon Oncorhynchus kisutch were either volitionally released or forcibly released for 3 years at two hatcheries. Results for the two release methods showed similar survivals for age-2 males (jacks) or age-3 fish. We suggest that volitional release could have benefits in feed savings and allow limited water to be redirected in the hatchery.
Collection, Removal, and Quantification of Eggs Produced by Rosy Red Fathead Minnows in Outdoor Pools
Authors: Clemment Troy , Stone Nathan 
Published: June 2004

Abstract
Eggs produced by rosy red fathead minnows Pimephales promelas held at four densities in 12 outdoor pools were collected and removed from substrate and had their numbers estimated. Adult fish were stocked at a sex ratio of 4:1 (females: males) and at densities of 5.1, 15.3, 25.4, or 35.6 fish/m2. Sodium sulfite (1.5–2.0%) was used to detach fathead minnow eggs from the spawning substrate. Egg numbers were estimated volumetrically based on an average (±SD) of 578 ± 34 eggs per milliliter. Mean daily egg numbers generally increased with fish density, and production ranged from 2,587 ± 2,999 to 9,595 ± 2,423 eggs/kg of broodfish. Averaging all treatments together for the 16-d period, over 6,000 eggs/d were collected per kilogram of broodfish. Based on this estimate, 500 kg of broodfish in a 1-ha pond would produce an average of 3 million eggs each day. Assuming an 80% hatching rate, this number of eggs would result in enough fry to stock a 0.5–1.0-ha pond. The results imply that an intensive production method consisting of harvesting eggs from ponds, indoor hatching, and subsequent fry stocking (as is now practiced for other baitfish species) could be feasible for fathead minnows.
Preliminary Assessment of Sex Inversion of Farmed Atlantic Salmon by Dietary and Immersion Androgen Treatments
Authors: Lee Peter , King Harry , Pankhurst Ned 
Published: June 2004

Abstract
Dietary and immersion treatments with the androgens 17α-methyltestosterone (MT) and 17α-methyldihydrotestosterone (MDHT) were assessed for their efficacy in the masculinization of Atlantic salmon Salmo salar. Dietary treatments with MT at 1 or 3 mg/kg food or MDHT at 1 mg/kg food for 800 degree-days resulted in 100% masculinization of all female stocks. Single or double immersion treatments of alevins in MDHT at 400 μg/L for 120 min during the period 0–28 d after median hatch resulted in significant masculinization. Immersion treatments were most effective when conducted more than 14 d after median hatch. Two immersion treatments 7 or 14 d apart resulted in masculinization levels of up to 100%, whereas single immersions yielded levels up to 77%. Immersion treatment resulted in the production of significantly more sex-inverted males with patent sperm ducts than did dietary treatment. The study shows that immersion treatments are simple and effective for androgen-induced masculinization of Atlantic salmon, that they are suitable for commercial-scale use in hatcheries, and that they offer advantages in production efficiency over dietary treatments.
Use of Hydrogen Peroxide during Incubation of Landlocked Fall Chinook Salmon Eggs in Vertical-Flow Incubators
Authors: Barnes Michael E , Gaikowski Mark P 
Published: June 2004

Abstract
Six different hydrogen peroxide treatment regimes were evaluated in a series of three trials with landlocked fall Chinook salmon Oncorhynchus tshawytscha eggs incubated in vertical-flow incubators. Six daily 15-min hydrogen peroxide treatment regimes (1,000 mg/L; 1,000 mg/L with a decrease to 500 mg/L during estimated blastopore formation; 2,000 mg/L; 2,000 mg/L with a decrease to 500 mg/L during estimated blastopore formation; 2,500 mg/L; and 2,500 mg/L with a decrease to 500 mg/L during estimated blastopore formation) were compared with daily 15-min treatments of 1,667 mg/L of formalin. Mortality at egg eye-up and fry hatch and from eye-up to hatch was significantly greater in eggs receiving the 2,500-mg/L hydrogen peroxide treatments throughout incubation and in those receiving 2,500 mg/L hydrogen peroxide with a decrease to 500 mg/L during blastopore formation than in either of the 1,000-mg/L hydrogen peroxide treatment regimes or the formalin-treated eggs in the first trial. No significant differences in mortality were observed among any of the treatments in the subsequent two trials with maximum hydrogen peroxide concentrations of 2,000 mg/L. Fungal infestations were observed primarily in the incubation trays treated at either of the 1,000-mg/L hydrogen peroxide regimens, as well as in those trays whose treatment concentrations were dropped to 500 mg/L during blastopore formation. Infestations were not observed in any of the formalin-treated trays. If minor fungal infestation is acceptable, then daily hydrogen peroxide treatments of 1,000 mg/L for 15 min would probably provide adequate fungal control compared with formalin usage.