bluuebunny/crossref_metadata_2025 huggingface dataset:
Absence of eye shine and tapetum in the heterogeneous eye ofAnthocharisbutterflies (Pieridae)
Authors: Takemura Shin-ya , Stavenga Doekele G. , Arikawa Kentaro
Published: August 2007

Insect eyes are composed of spectrally heterogeneous ommatidia, typically with three different types. The ommatidial heterogeneity in butterflies can be identified non-invasively by the colorful eye shine, the reflection from the tapetal mirror located at the proximal end of the ommatidia, which can be observed by epi-illumination microscopy. Since the color of eye shine is determined by the spectral properties of the ommatidia, it has been tentatively related to color vision. In the course of a survey of ommatidial heterogeneity in butterflies, we found that members of the pierid genus Anthocharis lack the eye shine. We therefore carried out anatomy of the eye of the yellow tip, Anthocharis scolymus, and correlated it with the absence of the tapetum. The butterfly tapetum is a remnant of the ancestral moth tapetum, a trait that has been completely lost in the papilionids and also, as now appears, in the genus Anthocharis. Anatomical investigations also revealed that, considering rhabdom shape,peri-rhabdomal pigment clusters and autofluorescence, the ommatidia can be divided in at least two different types, which are randomly distributed in the retina.
Kinematic analysis of an appetitive food-handling behavior: the functional morphology of Syrian hamster cheek pouches
Authors: Buckley Carolyn A. , Schneider Jill E. , Cundall David
Published: August 2007

Prodigious food hoarding in Syrian hamsters Mesocricetus auratusWaterhouse is strongly linked to appetite and is made possible by large internal cheek pouches. We provide a functional analysis of the cheek pouch and its associated retractor muscle. Frame-by-frame analysis of videotaped pouch-filling behavior revealed multiple jaw cycles for each food item pouched and the use of more jaw cycles to pouch large food items (∼2.5 g chow pellets) than small (corn kernels or sunflower seed with husks). These results stand in contrast to previously reported pouching kinematics in the externally pouched Dipodomys deserti, which uses only one jaw cycle per pouching event. Comparison of pouching and mastication in the same individuals also suggests that in Syrian hamsters, feeding jaw cycles are modulated to accommodate pouch filling primarily by the addition of a pause between fast open and fast close phases, which we call `gape phase'. Contrary to previous assertions, the retractor muscle does not merely provide structural support for the full pouch during locomotion. Video analysis of ten hamsters with unilaterally denervated retractor muscles and electrophysiological study of an anaesthetized subject confirmed that retractor muscle activity during pouch filling increases pouching efficiency for food items subsequent to the first.
Functional identification of an osmotic response element (ORE) in the promoter region of the killifish deiodinase 2 gene (FhDio2)
Authors: López-Bojórquez L. , Villalobos P. , García-G. C. , Orozco A. , Valverde-R. C.
Published: August 2007

The physiological role played by thyroid hormones (TH) in hydro-osmotic homeostasis in fish remains a controversial issue. Previous studies have shown that in Fundulus heteroclitus (killifish) hypo-osmotic stress increases liver iodothyronine deiodinase type 2 (D2) mRNA and D2 activity. In this study we identified two conserved osmotic response element (ORE) motifs in the promoter region of the killifish D2 gene (FhDio2) and examined their possible role in the transcriptional regulation of FhDio2during hypo-osmotic stress. As assessed by the electrophoretic mobility shift assay, results from in vivo and in vitro experiments demonstrate that exposure to an abrupt hyposmotic challenge triggers in the liver of killifish a strong nuclear recruitment of a putative osmotic response element binding protein (OREBP). This protein–DNA binding is time-dependent, attains a maximum within 2–8 h after the osmotic stress,and is followed by a significant increase in D2 activity. Furthermore,protein–DNA binding and the subsequent elevation in enzyme activity were blocked by the tyrosine kinase inhibitor genistein. Thus, during hypo-osmotic stress, a putative OREBP kinase-activated pathway stimulates FhDio2transcription and enzymatic activity. These data and the fact that D2 is the major enzyme providing local intracellular T3 suggest that TH plays a direct role in osmoregulation in fish, possibly by participating in hepatic ammonia metabolism. This study provides important insight into the physiological role of TH in hydro-osmotic homeostasis in fish.
The hungry caterpillar: an analysis of how carbohydrates stimulate feeding inManduca sexta
Authors: Glendinning John I. , Jerud Adrienne , Reinherz Ariella T.
Published: August 2007

In most insects, the taste of carbohydrates stimulates an immediate appetitive response. The caterpillar of Manduca sexta is an exception to this general pattern. Despite eliciting a strong peripheral gustatory response, high concentrations of carbohydrates (e.g. glucose or inositol)stimulate the same intensity of biting as water during 2-min tests. We suspected that the lack of feeding stimulation reflected the fact that prior studies used single carbohydrates (e.g. sucrose), which M. sextawould rarely encounter in its host plants. We hypothesized that the feeding control system of M. sexta responds selectively to carbohydrate mixtures. To test this hypothesis, we ran three experiments. First, we stimulated the two taste sensilla that respond to carbohydrates (the lateral and medial styloconic) with a battery of carbohydrates. These sensilla responded exclusively to sucrose, glucose and inositol. Second, we determined the response properties of the carbohydrate-sensitive taste cells within both sensilla. We found that one class of carbohydrate-sensitive taste cell responded to sucrose, and two other classes each responded to glucose and inositol. Third, we examined the initial biting responses of caterpillars to disks treated with solutions containing single carbohydrates (sucrose, glucose or inositol) or binary mixtures of these carbohydrates. The only solutions that stimulated sustained biting were those that activated all three classes of taste cell (i.e. sucrose+inositol or sucrose+glucose). We propose that the brain of M. sexta monitors input from the different classes of carbohydrate-sensitive taste cell, and generates protracted feeding responses only when all three classes are activated.
Unsteady locomotion: integrating muscle function with whole body dynamics and neuromuscular control
Authors: Biewener Andrew A. , Daley Monica A.
Published: August 2007

By integrating studies of muscle function with analysis of whole body and limb dynamics, broader appreciation of neuromuscular function can be achieved. Ultimately, such studies need to address non-steady locomotor behaviors relevant to animals in their natural environments. When animals move slowly they likely rely on voluntary coordination of movement involving higher brain centers. However, when moving fast, their movements depend more strongly on responses controlled at more local levels. Our focus here is on control of fast-running locomotion. A key observation emerging from studies of steady level locomotion is that simple spring-mass dynamics, which help to economize energy expenditure, also apply to stabilization of unsteady running. Spring-mass dynamics apply to conditions that involve lateral impulsive perturbations, sudden changes in terrain height, and sudden changes in substrate stiffness or damping. Experimental investigation of unsteady locomotion is challenging, however, due to the variability inherent in such behaviors. Another emerging principle is that initial conditions associated with postural changes following a perturbation define different context-dependent stabilization responses. Distinct stabilization modes following a perturbation likely result from proximo-distal differences in limb muscle architecture, function and control strategy. Proximal muscles may be less sensitive to sudden perturbations and appear to operate, in such circumstances, under feed-forward control. In contrast, multiarticular distal muscles operate, via their tendons, to distribute energy among limb joints in a manner that also depends on the initial conditions of limb contact with the ground. Intrinsic properties of these distal muscle–tendon elements, in combination with limb and body dynamics, appear to provide rapid initial stabilizing mechanisms that are often consistent with spring-mass dynamics. These intrinsic mechanisms likely help to simplify the neural control task, in addition to compensating for delays inherent to subsequent force- and length-dependent neural feedback. Future work will benefit from integrative biomechanical approaches that employ a combination of modeling and experimental techniques to understand how the elegant interplay of intrinsic muscle properties, body dynamics and neural control allows animals to achieve stability and agility over a variety of conditions.
Analytical and numerical investigation of the flow past the lateral antennular flagellum of the crayfishProcambarus clarkii
Authors: Humphrey Joseph A. C. , Mellon DeForest
Published: August 2007

Analytical and numerical methodologies are combined to investigate the flow fields that approach and pass around the lateral flagellum of the crayfish Procambarus clarkii. Two cases are considered, the first being that of a free-flicking flagellum and the second corresponding to a flagellum fixed inside a small bore tube. The first case is the natural one while the second corresponds to the experimental configuration investigated by Mellon and Humphrey in the accompanying paper. In that study the authors observed a hydrodynamic-dependent asymmetry in the spiking responses recorded from single, bimodally sensitive local interneurons (Type I) in the crayfish deutocerebrum, whereby the direction of an abruptly initiated flow of freshwater (or odorant) past the flagellum resulted in consistently larger numbers of spikes in response to the hydrodynamic stimulation when the flow direction was proximal-to-distal. In this communication we show that the proximal-to-distal and the distal-to-proximal flows produced in the flagellum-in-tube experiment correspond closely to the flows associated with the downward and upward flicks, respectively, of a free-flicking flagellum. We also show from calculations of the drag forces acting on the putative mechanoreceptor sensilla circumferentially distributed around a free-flicking flagellum that there are at least three sources of hydrodynamic asymmetry possibly related to the electrophysiological asymmetry observed: (i) the sense of the drag forces acting on medial and lateral mechanoreceptors changes in the same way for both with change in flick direction; (ii) during a downward(an upward) flick, a ventral (dorsal) mechanoreceptor experiences a larger drag force magnitude than a dorsal (ventral) mechanoreceptor; (iii) because of the difference in speeds between downward and upward flicks, the magnitudes of the drag forces acting on medial, lateral and ventral mechanoreceptors during a downward flick are about two times larger relative to the forces acting on medial, lateral and dorsal mechanoreceptors during an upward flick. All three of these naturally occurring hydrodynamic asymmetries are correctly reproduced in the flagellum-in-tube experiment.
Developmental changes in central O2 chemoreflex in Rana catesbeiana: the role of noradrenergic modulation
Authors: Fournier Stéphanie , Allard Mathieu , Roussin Stéphanie , Kinkead Richard
Published: August 2007

The in vitro brainstem preparation from Rana catesbeianashows a functional central O2 chemoreflex. Acute brainstem exposure to hypoxic superfusate elicits lung burst frequency responses that change over the course of development. Based on studies suggesting that brainstem noradrenergic neurons are involved in this reflex, we tested the following two hypotheses in vitro: (1) activation of adrenoceptors is necessary for the expression of the fictive lung ventilation response to hypoxia, and (2)changes in fast, Cl–-dependent neurotransmission(GABA/glycine) contribute to developmental changes in noradrenergic modulation. Experiments were performed on preparations from pre-metamorphics tadpoles (TK stages V–XIII) and adult bullfrogs. Acute exposure to hypoxic superfusate (98% N2, 2% CO2) increased fictive lung ventilation frequency in the pre-metamorphic group, whereas a decrease was observed in adults. Buccal burst frequency was unchanged by hypoxia. Noradrenaline (NA; 5 μmol l–1) bath application mimicked both fictive breathing responses and application of theα 1-antagonist prazosine (0.5 μmol l–1)blocked the lung burst response to hypoxia in both groups. Blocking GABAA/glycine receptors with a bicuculine/strychnine mixture (1.25μmol l–1/1.5 μmol l–1, respectively)or activation of GABAB pre-synaptic autoreceptors with baclofen(0.5 μmol l–1) prevented the lung burst response to hypoxia and to the α1-agonist phenylephrine (25 μmol l–1) in both stage groups. We conclude that NA modulation contributes to the central O2 chemoreflex in bullfrog, which acts via GABA/glycine pathways. These data suggest that maturation of GABA/glycine neurotransmission contributes to the developmental changes in this chemoreflex.
Swimming in the upside down catfishSynodontis nigriventris: it matters which way is up
Authors: Blake Robert W. , Chan Keith H. S.
Published: August 2007

Synodontis nigriventris is a surface-feeding facultative air-breather that swims inverted with its zoological ventral side towards the water surface. Their near-surface drag is about double the deeply submerged drag (due to wave drag) and roughly twice the sum of frictional and pressure drags. For streamlined technical bodies, values of wave drag augmentation near the surface may be five times the deeply submerged values. However, the depth dependence of drag is similar for fish and streamlined technical bodies, with augmentation vanishing at about 3 body diameters below the surface. Drag`inverted' is approximately 15% less than that `dorsal side up' near the surface. Consistent with this, at any given velocity, tailbeat frequency is lower and stride length higher for inverted swimming in surface proximity(P<0.05). Deeply submerged, there are no significant differences in drag and kinematics between postures (P>0.05). At the critical Froude number of 0.45, speeds in surface proximity correspond to prolonged swimming that ends in fatigue. To exceed these speeds, the fish must swim deeply submerged and this behaviour is observed. Inverted swimming facilitates efficient air breathing. Drag dorsal side up during aquatic surface respiration is 1.5 times the value for the inverted posture. Fast-starts are rectilinear, directly away from the stimulus. Average and maximum velocity and acceleration decrease in surface proximity (P<0.05) and are higher inverted (maximum acceleration: 20–30 m s–2; P<0.05) and comparable to locomotor generalists (e.g. trout). Mechanical energy losses due to wave generation are about 20% for inverted and 40% for dorsal side up, and lower than for trout fast-starting in shallow water (70% losses); bottom effects and large amplitude C-starts (c.f. relatively low amplitude rectilinear motions in S. nigriventris)enhance resistance in trout. S. nigriventris probably evolved from a diurnal or crepuscular `Chiloglanis-like' benthic ancestor. Nocturnality and reverse countershading likely co-evolved with the inverted habit. Presumably, the increased energy cost of surface swimming is offset by exploiting the air–water interface for food and/or air breathing.
Assessment of repeated displays: a test of possible mechanisms
Authors: Van Dyk Daniel A. , Taylor Alan J. , Evans Christopher S.
Published: August 2007

Many animals signal their resource holding potential (RHP) to deter competitors from engaging them in potentially costly fights. Studies of this opponent assessment function have generated important insights into signal design and evolution. In the case of sounds, rate of production is often a salient feature. We used digital video playback to conduct analogous experiments exploring the importance of temporal variation in visual signals. Our study focused on the push-up display of male Jacky dragons Amphibolurus muricatus, an Australian agamid lizard. This stereotyped movement-based signal is commonly performed during male–male contests. A previous study has shown that Jacky dragons responses are influenced by the overall display rate of a video conspecific. We built upon this finding by investigating the effect of short-term variation in display rate. Each playback sequence varied systematically across a different combination of display parameters, while keeping the total number of push-ups constant. Other potential cues, such as morphology and the characteristics of individual motor patterns, were precisely controlled. The aggressive signalling and locomotor behaviour of subject males varied significantly between sequences. Most notably, performance of throat expansions, a typical agamid threat posture,was suppressed by video sequences with temporal clumping of displays. These results show that lizards are sensitive to differences in the temporal fine structure of display sequences and suggest that display concentration is an important assessment cue.
Effects of mass and body composition on fasting fuel utilisation in grey seal pups (Halichoerus grypusFabricius): an experimental study using supplementary feeding
Authors: Bennett Kimberley A. , Speakman John R. , Moss Simon E. W. , Pomeroy Paddy , Fedak Mike A.
Published: August 2007

This study used supplementary feeding to test the hypothesis that fuel partitioning during the postweaning fast in grey seal pups is affected by size and composition of energy reserves at weaning, and by extra provisioning. Mass and body composition changes were measured during suckling and fasting to investigate the effect of natural differences in energy reserves at weaning on subsequent allocation of fat and protein to energy use. We fed seven pups for 5 days after weaning, to investigate the effect of increased fuel availability, and particularly protein, on fuel utilisation. After correcting for protein used during the moult, the proportional contribution of fat was 86–99% of total energy use. Pups with greater energy reserves, i.e. those that were heavier and fatter at weaning, had higher rates of fat and energy use. There was no significant relationship between adiposity at weaning and proportional contribution of fat to energy use, perhaps due to a limited sample size or range of body masses and adiposity. Supplemented individuals used energy, specifically fat, much faster and utilised proportionally less of their endogenous protein by departure than non-supplemented individuals. Fat metabolism contributed a similar percentage to daily energy use in both groups. These findings show that pups spare protein, even when energy use is dramatically increased. Pups that receive greater maternal provisioning and lay down more protein may have increased survival chances at sea. This study highlights the importance of protein reserves in first year survival of grey seal pups.
A comprehensive overview of hydrogen engine design features
Authors: Verhelst S , Verstraeten S , Sierens R
Published: August 2007

Realizing decreased CO2 emissions from the transport sector will be possible in the near future when substituting (part of) the currently used hydrocarbon-fuelled internal combustion engines (ICEs) with hydrogen-fuelled ICEs.

Hydrogen-fuelled ICEs have advanced to such a stage that, from the engine point of view, there are no major obstacles to doing this. The present paper indicates the advantages of hydrogen as a fuel for spark ignition (SI) internal combustion engines. It also shows how the hydrogen engine has matured.

An extensive overview is given of the literature on experimental studies of abnormal combustion phenomena, mixture formation techniques, and load control strategies for hydrogen-fuelled engines. The Transport Technology research group of the Department of Flow, Heat and Combustion Mechanics at Ghent University has been working on the development and optimization of hydrogen engines for 15 years. An overview of the most important experimental results is presented with special focus on the most recent findings.

The article concludes with a list of engine design features of dedicated hydrogen SI engines.
Suppression of heavy-truck driver-seat vibration using sliding-mode control and quantitative feedback theory
Authors: Rajapakse N. I. , Happawana G. S. , Hurmuzlu Y
Published: August 2007

The current paper presents a robust control method that combines sliding-mode control (SMC) and quantitative feedback theory (QFT) for designing a driver seat of a heavy vehicle to reduce driver fatigue. A mathematical model is considered to analyse tracking control characteristics through computer simulation in order to demonstrate the effectiveness of the proposed control methodology. The SMC is used to track the trajectory of the desired motion behaviour of the seat. However, when the system enters into sliding regime, chattering occurs owing to switching delays as well as vehicle system vibrations. The chattering is eliminated with the introduction QFT inside the boundary layer to ensure smooth tracking. Furthermore, using SMC alone requires higher actuator forces for tracking than using both the control schemes together, and causes various problems in selecting hardware. Problems with noise amplification, resonances, presence of uncertainties, and unmodelled high-frequency dynamics can largely be avoided with the use of QFT over other optimization methods. The main contribution of the present paper is to provide guidance in designing the controller to reduce heavy vehicle seat vibration so that the driver's sensation of comfort maintains a certain level at all times.
A fuzzy-neural system with error feedback to adjust classification for forecasting wafer lot flow time: A simulation study
Authors: Chen T , Wang Y-C
Published: August 2007

Estimating lot flow (cycle) time is a critical task for a wafer fabrication plant (wafer fab). Many recent studies have shown that pre-classifying wafer lots before estimating the flow times is beneficial to estimation accuracy. In this aspect, various classification approaches, e.g. k-means (kM), fuzzy c-means (FCM), and self-organization map (SOM), have been applied. After pre-classification, to estimate the flow times for lots belonging to different categories, different approaches (that are in fact the same approaches but with different parameter settings) are applied. However, these applications of classification approaches considered only the data of wafer lots, but ignored whether the classification approaches combined with the subsequent estimation techniques were suitable for the data. To tackle this problem, instead of trying many possible classification and forecasting approaches to find out the most suitable combination, a FCM and back propagation network (BPN) combination is chosen in the current study. In the proposed methodology, the classification results by FCM will be adjusted with forecasting error fed back from the BPN. In this way, if the FCM-BPN combination is not good enough for the data, then a forecasting error will be generated and fed back to the FCM classifier to adjust the classification results. After some replications, the FCM-BPN combination will become more suitable for the data. To evaluate the effectiveness, production simulation is applied in the present study to generate test data. According to experimental results, the forecasting accuracy of the proposed methodology is significantly better than those of many existing approaches. The effects of adjusting classification results with prediction error are also revealed.
High-order, sliding-mode-based precise control of direct-drive systems under heavy uncertainties
Authors: Bogosyan S , Arabyan A
Published: August 2007

The high-performance control of direct-drive (DD) systems requires the full system dynamic effects to be taken into account owing to the eliminated gear mechanism. The actuator dynamics and structural flexibilities become of increased importance, particularly when high-speed, high-accuracy operation of lightweight structures is aimed for; however, in most related literature, these effects are neglected to avoid increased computational complexity at the expense of compromising the tracking accuracy of the system in the transient and steady state. As a solution to the problem, in this study, high-order, sliding-mode (HOSM) controllers (HOSMCs) are developed, which exploit the robustness properties of sliding-mode controllers (SMCs) while also increasing accuracy by reducing chattering effects. Different from standard HOSMCs, which are derived by artificially increasing the system order, the third-order HOSM (3-HOSM) control laws in this study are derived by including the actuator dynamics and structural flexibilities in the control design process. Two HOSMCs are developed for this purpose: one with a discontinuous input and one with a continuous input aimed at reducing chattering. The performance of the novel HOSMCs is tested by simulations for the precise position and tracking control of a one-degree-of-freedom (1DOF) DD weapon-positioning system as an example of a direct-drive system under heavy uncertainties and external disturbances. The improved accuracy obtained, particularly with the novel continuous-input 3-HOSMC, motivates the implementation of the schemes for demanding control applications under heavy uncertainties.
Novel Neutrophil-Derived Proteins in Bronchoalveolar Lavage Fluid Indicate an Exaggerated Inflammatory Response in Pediatric Cystic Fibrosis Patients
Authors: McMorran Brendan J , Ouvry Patat Severine A , Carlin John B , Grimwood Keith , Jones Alun , Armstrong David S , Galati John C , Cooper Peter J , Byrnes Catherine A , Francis Paul W , Robertson Colin F , Hume David A , Borchers Christoph H , Wainwright Claire E , Wainwright Brandon J
Published: August 2007

Background: Airway inflammation in cystic fibrosis (CF) is exaggerated and characterized by neutrophil-mediated tissue destruction, but its genesis and mechanisms remain poorly understood. To further define the pulmonary inflammatory response, we conducted a proteome-based screen of bronchoalveolar lavage fluid (BALF) collected from young children with and without CF experiencing endobronchial infection.

Methods: We collected BALF samples from 45 children younger than 5 years and grouped them according to the presence of respiratory pathogens: ≥1 × 105 colony-forming units (CFU)/mL BALF (18 and 12 samples with and without CF, respectively) and <1 × 105 CFU/mL (23 and 15 samples). BALF proteins were analyzed with SELDI-TOF mass spectrometry (MS) and H4 ProteinChips®. Proteins were identified and characterized using trypsin digestion, tandem MS, Fourier transform ion cyclotron resonance MS, immunoblotting, and ELISA.

Results: The SELDI-TOF MS BALF profiles contained 53 unique, reliably detected proteins. Peak intensities of 24 proteins differed significantly between the CF and non-CF samples. They included the neutrophil proteins, α-defensin 1 and 2, S100A8, S100A9, and S100A12, as well as novel forms of S100A8 and S100A12 with equivalent C-terminal deletions. Peak intensities of these neutrophil proteins and immunoreactive concentrations of selected examples were significantly higher in CF than non-CF samples.

Conclusions: Small neutrophil-derived BALF proteins, including novel C-terminal truncated forms of S100A proteins, are easily detected with SELDI-TOF MS. Concentrations of these molecules are abnormally high in early CF lung disease. The data provide new insights into CF lung disease and identify novel proteins strongly associated with CF airway inflammation.
Novel Serum Biomarker Candidates for Liver Fibrosis in Hepatitis C Patients
Authors: Gangadharan Bevin , Antrobus Robin , Dwek Raymond A , Zitzmann Nicole
Published: August 2007

Background: Liver biopsy is currently the gold standard for assessing liver fibrosis, and no reliable noninvasive diagnostic approach is available. Therefore a suitable serologic biomarker of liver fibrosis is urgently needed.

Methods: We used a proteomics method based on 2-dimensional gel electrophoresis to identify potential fibrosis biomarkers. Serum samples from patients with varying degrees of hepatic scarring induced by infection with the hepatitis C virus (HCV) were analyzed and compared with serum from healthy controls.

Results: We observed the most prominent differences when we compared serum samples from cirrhotic patients with healthy control serum. Inter-α-trypsin inhibitor heavy chain H4 (ITIH4) fragments, α1 antichymotrypsin, apolipoprotein L1 (Apo L1), prealbumin, albumin, paraoxonase/arylesterase 1, and zinc-α2-glycoprotein were decreased in cirrhotic serum, whereas CD5 antigen-like protein (CD5L) and β2 glycoprotein I (β2GPI) were increased. In general, α2 macroglobulin (a2M) and immunoglobulin components increased with hepatic fibrosis, whereas haptoglobin and complement components (C3, C4, and factor H-related protein 1) decreased. Novel proteins associated with HCV-induced fibrosis included ITIH4 fragments, complement factor H-related protein 1, CD5L, Apo L1, β2GPI, and thioester-cleaved products of a2M.

Conclusions: Assessment of hepatic scarring may be performed with a combination of these novel fibrosis biomarkers, thus eliminating the need for liver biopsy. Further evaluation of these candidate markers needs to be performed in larger patient populations. Diagnosis of fibrosis during early stages will allow early treatment, thereby preventing fibrosis progression.
Feines Weizenmehl und ungenießbare Spelzen. Gregors des Großen Wertschätzung augustinischerTheologie
Authors: Greschat Katharina
Published: August 2007

This article tries to examine the way in which Gregory the Great made use of some topics of his admired model Augustine within his own world towards the end of the sixth century under the emperor Justinian and his successors. It is intended to show that Gregory's handling of the Augustinian theology is not a simplification for the uneducated of the early Middle Ages but quite a sophisticated application and further development for those people who read and knew the important writings of the great Augustine.
Aquinas or Augustine? On the sources of Gabriel Biel's Canonis Missae Expositio
Authors: Geest Paul van
Published: August 2007

Gabriel Biel, der sowohl die durch Thomas von Aquin repräsentierte via antiqua als auch die durch Scotus und Ockham repräsentierte via moderna studierte, wurde als ein Hauptvertreter der via moderna angesehen, genauer als Vertreter des Nominalismus der via moderna. Das Ziel des Artikels besteht darin, die Auswirkungen von Thomas' Denken auf Biels Werk herauszuarbeiten, besonders seine geistlichen Aspekte und unter Berücksichtigung seiner Augustinrezeption. Thomas' Werk scheint für Biel besonders dort wichtig zu sein, wo Biel einige Hauptpunkte seiner verehrenden Spiritualität beschreibt. Gleichwohl nimmt Thomas eine vergleichsweise geringe Rolle unter den auctoritates bei Biel ein, unter denen die Verfasser biblischer Schriften und Augustin hervorragen. Insgesamt diente Thomas Biel also mehr als Inspiration denn als Legitimation.
Re-interpreting Augustine: Ralph Cudworth and Jacobus Arminius on Grace and Free Will
Authors: Stanciu Diana
Published: August 2007

Ziel des Aufsatzes ist es, den Einfluß Augustins auf Ralph Cudworth, einen Cambridge Platonist aus dem 17. Jh., zu beschreiben. Obwohl Cudworth Augustin selten namentlich nennt, wählt er sorgfältig Passagen aus Augustin aus und interpretiert sie neu, um sein eigenes Ziel zu verfolgen, das darin besteht, Vernunft und Glaube miteinander zu versöhnen. So benutzt Cudworth viele augustinische Vorstellungen, etwa die von Gnade und Sünde oder Erkenntnis als Erleuchtung, um seine eigene Argumentation zu stützen. Außerdem ist eine erstaunliche Parallele im Augustingebrauch zwischen Cudworth und Arminius festzustellen. Dies führt zu der Frage, ob Curdworth für seine Augustinkenntnis auf Arminius zurückgegriffen hat. Die Beobachtung, daß Cudworth oft Augustinpassagen zitiert, die bei Arminius zitiert werden, besonders solche über Gnade und freien Willen, untermauert die Vermutung, daß Cudworth Arminius' Werke gelesen und für seine Augustinrezeption benutzt hat. Damit ist eine Verbindung zwischen Cambridge Platonists und den Arminianern greifbar, die darin begründet sein könnte, daß Cudworth gerade platonische bzw. neuplatonische Ideen bei Augustin rezipiert hat.
Augustine, ‘Pelagianism’, Julian of Aeclanum and Modern Scholarship
Authors: Lössl Josef
Published: August 2007

Ziel des Artikels ist es, herauszuarbeiten, daß ‚Paulusrezeption‘ im Westen nicht nur ‚Augustinusrezeption‘ ist. Augustin hat nicht den lateinischen Diskurs über Paulus erfunden, sondern sich daran neben anderen beteiligt. Ausgehend von den Debatten zwischen Augustin, Pelagius und Julian von Aeclanum, untersucht der Artikel den Kontext, in dem der lateinische Diskurs über Paulus entstand und sich entwickelte, sowie die Art und Weise, wie die Forschung der letzten drei Jahrhunderte damit umgegangen ist. Die Paulusrezeption in der lateinischen Theologie bildete eine Basis für den Pelagianischen Streit, mit Folgen bis heute. Augustin hat das traditionelle Bild von Julian als dem Architekten des Pelagianischen Systems geprägt, welches sich bis in die moderne Forschung wiederfindet. Gleichwohl ist die Frage zu stellen, inwiefern Julian auch im soziologischen Sinne ein Pelagianer – im Unterschied zu einem Nicht-Pelagianer – war. Julian seinerseits hat Augustins Orthodoxie in Frage gestellt, insbesondere seine Paulusinterpretation und sein Verständnis von der Schöpfung aus dem Nichts. Die wissenschaftliche Beschäftigung mit Julian, die dessen Theologie auf dem Hintergrund der Alternative Pelagianismus oder Augustinismus zu beschreiben versuchte, war dementsprechend hinsichtlich der Bedeutung Julians für den Pelagianischen Streit gespalten, ein Hinweis auf eine tiefe Krise der Moderne.
Modern Augustinian Biographies: Revisions and Counter-Memories
Authors: Baker-Brian Nicholas
Published: August 2007

Der Artikel gibt einen Überblick über die Augustinbiographien der Antike (Possidius, Petilian, Vincent von Cartennae, Secundinus, Pelagius und Julian von Aeclanum) und Neuzeit (Tillemont, van der Meer, Bonner, Parke, Dassmann, Rist, Stock, Bertrand, De Wohl, Gaarder, Brown, O'Donnell). Der Grund für die große Zahl von Biographien dürfte darin begründet sein, daß Augustin selbst über sich in einer Weise gesprochen hat, die eine Biographie besonders gut ermöglicht hat. Brown, der eine der am weitesten verbreiteten und angesehenen modernen Augustinbiographien geschrieben hat, benutzt Sprache und Vorstellung einer „Psychobiographie“. In jüngerer Zeit unterscheidet demgegenüber O'Donnell's Biographie ‚Augustine, Sinner and Saint. A New Biography‘ zwei Formen des Verstehens von Augustins Leben, nämlich a) den Augustin in seiner Zeit als historische Figur, b) die diachrone Augustingestalt als Gegenstand der Erinnerung. Eine solche „mnemohistorische“ Betrachtung von Erinnerungserzählungen würde den letzteren Weg verfolgen, wie er von zeitgenössischen Gegnern Augustins, aber auch wieder in Erzählungen späterer Zeit erscheint. Nur so kommt es zu Augustin als „Ikone“ und zugleich zur Ablehnung dieser Ikone, bzw. zu Augustin als Tabu.
Artificial Roofing Slates and Shingles
Authors: Cash Carl G. , Condren Stephen J. , Gumpertz Werner H.
Published: August 2007

Early in the 1980s, manufacturers started to respond to the market desires for a Class A fire-rated steep-sloped roofing material. Other manufacturers sought slate-like roofs that were lower in cost than natural slate. Both groups tried a variety of materials and cellulose fibers including fibers recovered from newsprint, bundles of wood, and more fibrous or shredded wood to reinforce portland cement matrixes. Previously, asbestos fiber was used with cement to form very durable asbestos-cement shingles, sidings, and sheets. Many manufacturers felt they could replace asbestos with other materials and did so offering performance warranties of 25 to 50 years duration. The authors have investigated and tested eleven of these artificial shakes and slates manufactured by nine manufacturers. Hundreds of roofs have been examined in more than 20 states. Some products failed before the installation was completed. Few survived past their tenth year of exposure. None of the artificial shakes and slates investigated are currently manufactured in the United States. We provide data that were generated by our laboratory tests on thousands of specimens made by nine manufacturers (A through I), identify the reinforcements present, list some of the critical properties such as flexural strength, deflection at break, and water absorption, and the specific failure modes for each product. The principal recommendation to avoid failures of this kind is to use products that have a substantial history of effective performance in the environment to which they will be used. Proceed into a market place cautiously when formulation changes are made to products with successful track records.
Strength of a Ceramic Sectored Flexural Test Specimen
Authors: Wereszczak A. A. , Duffy S. F. , Baker E. H. , Swab J. J. , Champoux G. J.
Published: August 2007

A new test specimen, defined here as the “sectored flexural strength test specimen,” was developed to measure the strength of ceramic tubes specifically for circumstances when flaws located at the tube’s outer diameter are the strength-limiter when subjected to axial tension. The understanding of such strength-limitation is relevant when ceramic tubes are subjected to bending or when the internal temperature is hotter than the tube’s exterior (e.g., heat exchangers). The test specimen is both economically and statistically attractive because eight test specimens (eight in the case of this project—but the user is not necessarily limited to eight) were extracted out of each length of tube. An analytic expression for maximum (or failure) stress, and relationships portraying effective area and effective volume as a function of Weibull modulus were developed. Lastly, it was shown through the testing of two ceramics that the sectored flexural specimen was very effective; it produced failures caused by strength-limiting flaws located on the tube’s original outer diameter.
The ski camp doctor’s role in the the prevention of winter sport accidents
Authors: Felkai Péter
Published: August 2007

A tavalyi év több halálos végű téli sportbaleseteinek száma, mely különösen a gyermekkorúak síelésével volt kapcsolatos, felvetette azt a gondolatot, hogy a síelő csoportokat olyan kiképzett orvosok kísérjék, akik alkalmasak arra, hogy a téli sportokkal kapcsolatos sürgősségi helyszíni ellátást elkezdjék, és ezáltal a balesetek és megbetegedések következményeit enyhítsék. Mivel hasonló kezdeményezésről még nem számol be a szakirodalom, a jelen közlemény megpróbálja összefoglalni a sítábororvosokkal szemben támasztott szakmai követelményeket, valamint felméri a tábororvosok feladatkörét. A sítábororvos, bármely diszciplína művelője is, jártas kell hogy legyen az utazási orvostan alapkérdéseiben és a sürgősségi betegellátás készségszintű művelésében. Prevenciós feladatai között szerepel az utazás előtti egészségfelmérés, a szokványos megbetegedések felismerése és kezelése a helyszínen, az orvosi elsősegély nyújtása a sípályán, valamint a beteg ellátásának és hazaszállításának megszervezése. Az elképzelés helyességét bizonyította az első sítábororvos-képzés sikere, melynek folyamán a résztvevők nemcsak az orvosi elméleti alapokat sajátították el, hanem hivatásos síoktatók is javították az orvosok sítechnikai tudását. A képzés része volt még a síbalesetek jogi és biztosítói oldalról való elemzése is. A nagy érdeklődésre való tekintettel a sítábororvosi tanfolyamot rendszeressé kell tenni, a képzésbe belevonva a külföldi hegyi mentőszolgálatokat is. Az iskoláscsoportok síbaleseteinek megelőzésében nagy szerepe lehet a kiképzett tábororvosoknak, akik névsora az utazási irodák rendelkezésére bocsátható. Remélhető, hogy a kezdeményezést az utazási biztosítók is felkarolják, mert a sítábororvos jelenléte nagyban csökkentheti a kárhányadot és a károsodás mértékét.
Screening for early detection of lung cancer: Conflict between clinical and public health points of view
Authors: Döbrőssy Lajos , Kovács Attila , Budai András , Cornides Ágnes
Published: August 2007

Magyarországon a tüdőrák a vezető daganatos halálok, amely a nők között mind gyakoribb. A hagyományosan mellkasi röntgenvizsgálaton és a köpet citológiai vizsgálatán alapuló szűrővizsgálata a szakma mai állása szerint nem ajánlott, mert a szűrővizsgálat nem csökkenti a tüdőrákból eredő halálozást. Az alacsony dózisú spirál-komputertomográfia (LDCT) ígéretes, mert érzékenyen mutatja ki a tüdőbeli apró gócokat, a módszer azonban nem fajlagos. A folyamatban lévő randomizált, ellenőrzött tanulmányoktól (RTC) évek múlva várható eredmény, addig tömeges vizsgálatokra nem ajánlható. Hazánkban a tüdőrákok mintegy harmadát ernyőkép-szűrővizsgálat alkalmával fedezik fel, többségüket még operálható állapotban, ez azonban a népességbeli halálozást nem befolyásolja. A szerzők álláspontja szerint a rosszindulatú tüdődaganatok felismerése – különösen a magasan veszélyeztetett 40 éven felüli dohányzó férfiak esetében – a tuberkulózis leküzdésére létrehozott ernyőkép-szűrőrendszer hasznos mellékterméke lehet, népegészségügyi szűrőtevékenységet kezdeményezni azonban nem indokolt. Jelenleg a tüdőrák-epidémia megfékezésére hathatós dohányzásellenes intézkedések ajánlhatók.
Dietary survey in Hungary, 2003–2004. Micronutrients: vitamins
Authors: Zajkás Gábor , Bíró Lajos , Greiner Erika , Szórád Ildikó , Ágoston Helga , Balázs Anikó , Vitrai József , Hermann Dóra , Boros Julianna , Németh Renáta , Kéki Zsuzsanna , Martos Éva
Published: August 2007

A harmadik hazai országos táplálkozási vizsgálat az Országos Lakossági Egészségfelmérés (OLEF) keretében valósult meg, ennek megfelelően az adatfelvétel 2003 november–decemberében történt. A vizsgálat 19 éven felüliekre terjedt ki, 1179 fő táplálkozási adatfelvétele volt értékelhető, az energia- és makrotápanyag-beviteli eredmények 2005-ben, az ásványianyag-beviteli adatok 2007-ben az Orvosi Hetilapban kerültek közlésre, ezúttal a vitaminbevitel bemutatására kerül sor. Az eredmények értékeléséhez a szerzők felhasználják a két korábbi hazai és hasonló külföldi vizsgálatok adatait, valamint a magyar és nemzetközi tápanyag-beviteli ajánlásokat. Az eredmények közül kedvezőnek ítélhető az ajánlásoknak mindkét nemben megfelelő retinolekvivalens-, B
1
-, B
6
-, B
12
-vitamin- és niacin-, biotin-, valamint a férfiak esetében emellett az elegendő E-vitamin-bevitel. Kedvezőtlennek minősül a jelenlegi vizsgálatban mindkét nemben elégtelen B
2
-, C- és D-vitamin-, valamint pantoténsav-bevitel, továbbá a folátok ajánlott mennyiségnél kisebb átlagos bevitele és emellett a nők elégtelen E-vitamin-bevitele. Magyarországon először ebben a táplálkozási vizsgálatban került sor D-vitamin, biotin, pantoténsav és folátok bevitelének meghatározására. A szerzők nyomatékosan hangsúlyozzák a kellően változatos és egészséges táplálkozás jelentőségét a lakosság megfelelő vitaminellátottsága érdekében.
Disruption of Heparan and Chondroitin Sulfate Signaling Enhances Mesenchymal Stem Cell-Derived Osteogenic Differentiation via Bone Morphogenetic Protein Signaling Pathways
Authors: Manton Kerry J. , Leong Denise F. M. , Cool Simon M. , Nurcombe Victor
Published: August 2007

Cell surface heparan sulfate (HS) and chondroitin sulfate (CS) proteoglycans have been implicated in a multitude of biological processes, including embryonic implantation, tissue morphogenesis, wound repair, and neovascularization through their ability to regulate growth factor activity and morphogenic gradients. However, the direct role of the glycosaminoglycan (GAG) sugar-side chains in the control of human mesenchymal stem cell (hMSC) differentiation into the osteoblast lineage is poorly understood. Here, we show that the abundant cell surface GAGs, HS and CS, are secreted in proteoglycan complexes that directly regulate the bone morphogenetic protein (BMP)-mediated differentiation of hMSCs into osteoblasts. Enzymatic depletion of the HS and CS chains by heparinase and chondroitinase treatment decreased HS and CS expression but did not alter the expression of the HS core proteins perlecan and syndecan. When digested separately, depletion of HS and CS chains did not effect hMSC proliferation but rather increased BMP bioactivity through SMAD1/5/8 intracellular signaling at the same time as increasing canonical Wnt signaling through LEF1 activation. Long-term culturing of cells in HS- and CS-degrading enzymes also increased bone nodule formation, calcium accumulation, and the expression of such osteoblast markers as alkaline phosphatase, RUNX2, and osteocalcin. Thus, the enzymatic disruption of HS and CS chains on cell surface proteoglycans alters BMP and Wnt activity so as to enhance the lineage commitment and osteogenic differentiation of hMSCs.

Disclosure of potential conflicts of interest is found at the end of this article.
Lentiviral Rescue of Vascular Endothelial Growth Factor Receptor-2 Expression in Flk1−/− Embryonic Stem Cells Shows Early Priming of Endothelial Precursors
Authors: Li Xiujuan , Edholm Dan , Lanner Fredrik , Breier Georg , Farnebo Filip , Dimberg Anna , Claesson-Welsh Lena
Published: August 2007

The vascular endothelial growth factor (VEGF) family and its receptors are important for vascular development and maintenance of blood vessels, as well as for angiogenesis, the formation of new vessels. Loss of VEGF receptor-2 (VEGFR-2; designated Flk-1 in mouse) results in arrest of vascular and hematopoietic development in vivo. We used lentiviral transduction to reconstitute VEGFR-2 expression in flk1−/− embryonic stem (ES) cells. VEGF-induced vasculogenesis and sprouting angiogenesis were rescued in transduced ES cultures differentiating in vitro as EBs. Although the transgene was expressed in the pluripotent stem cells and lacked linage restriction during differentiation, the extent of endothelial recruitment was similar to that in wild-type EBs. Reconstitution of VEGFR-2 in flk1−/− ES cells allowed only precommitted precursors to differentiate into functional endothelial cells able to organize into vascular structures. Chimeric EB cultures composed of wild-type ES cells mixed with flk1−/− ES cells or reconstituted VEGFR-2-expressing ES cells were created. In the chimeric cultures, flk1−/− endothelial precursors were excluded from wild-type vessel structures, whereas reconstituted VEGFR-2-expressing precursors became integrated together with wild-type endothelial cells to form chimeric vessels. We conclude that maturation of endothelial precursors, as well as organization into vascular structures, requires expression of VEGFR-2.

Disclosure of potential conflicts of interest is found at the end of this article.