bluuebunny/crossref_metadata_2025_split huggingface dataset:
Acoustic scanning of natural scenes by echolocation in the big brown bat, Eptesicus fuscus
Authors: Surlykke Annemarie , Ghose Kaushik , Moss Cynthia F. 
Published: March 2009

SUMMARY
Echolocation allows bats to orient and localize prey in complete darkness. The sonar beam of the big brown bat, Eptesicus fuscus, is directional but broad enough to provide audible echo information from within a 60–90 deg. cone. This suggests that the big brown bat could interrogate a natural scene without fixating each important object separately. We tested this idea by measuring the directional aim and duration of the bat's sonar beam as it performed in a dual task, obstacle avoidance and insect capture. Bats were trained to fly through one of two openings in a fine net to take a tethered insect at variable distances behind the net. The bats sequentially scanned the edges of the net opening and the prey by centering the axis of their sonar beam with an accuracy of ∼5 deg. The bats also shifted the duration of their sonar calls, revealing sequential sampling along the range axis. Changes in duration and directional aim were correlated, showing that the bat first inspected the hole, and then shifted its gaze to the more distant insect,before flying through the net opening. Contrary to expectation based on the sonar beam width, big brown bats encountering a complex environment accurately pointed and shifted their sonar gaze to sequentially inspect closely spaced objects in a manner similar to visual animals using saccades and fixations to scan a scene. The findings presented here from a specialized orientation system, echolocation, offer insights into general principles of active sensing across sensory modalities for the perception of natural scenes.
Nitric oxide increases myocardial efficiency in the hypoxia-tolerant turtle Trachemys scripta
Authors: Misfeldt Mikkel , Fago Angela , Gesser Hans 
Published: March 2009

SUMMARY
Nitric oxide (NO) may influence cardiac mechanical performance relative to O2 consumption by depressing respiration rate and by affecting the excitation–contraction coupling. Such effects of NO should be particularly important during hypoxia in species such as the hypoxia-tolerant turtle Trachemys scripta. In heart ventricle preparations from this species, the ratio of twitch force to O2 consumption increased by approximately 15% during full oxygenation and by approximately 60% during hypoxia in the presence of added l-arginine [the substrate for nitric oxide synthase (NOS)]. This effect was primarily due to a decrease in O2 consumption and may represent an increase in the twitch force obtained per ATP and/or in the ATP obtained per O2. Lactate production during hypoxia did not differ between preparations treated with either l-arginine or asymmetric dimethylarginine (ADMA), an inhibitor of NOS, suggesting that NO does not elicit a compensatory increase in anaerobic metabolism. ADMA did not reverse the effects of l-arginine on O2 consumption significantly, although pre-treatment with ADMA abolished the effect of l-arginine,consistent with the competitive binding of l-arginine and ADMA to NOS. Histochemical studies using the fluorescent probe 4,5-diaminofluorescein diacetate (DAF-2 DA) revealed NO production in the presence of added l-arginine. In conclusion, NO may augment heart contractility obtained per O2 by deceasing O2 consumption without affecting either lactate production or developed force. This effect was particularly pronounced under O2 deficiency and may therefore contribute towards preserving cardiac function and to the overall excellent hypoxic tolerance of the turtle.
Responses of hatchlingXenopustadpoles to water currents: first function of lateral line receptors without cupulae
Authors: Roberts Alan , Feetham Ben , Pajak Mark , Teare Tom 
Published: March 2009

SUMMARYAt later stages in larval life and also as adults, Xenopus can respond to water currents detected by their lateral-line sensory system. We have investigated when responses to water currents first appear and whether the first lateral line neuromasts operate in the same way as the adult organs. Just before and after hatching from their egg membranes we show that Xenopus embryos and tadpoles can respond to water currents by swimming into them. Local stimulation in immobilised animals where motor activity was recorded electrically suggested that the receptors detecting water currents were located between the eyes and the gills and were innervated by cranial nerves. In behaving tadpoles, responses to water currents were reduced following skin abrasion caudal to the eyes or treatment with neomycin,which is known to block hair cell function. We therefore used scanning electron microscopy to establish that rows of lateral line neuromasts with hair cells and kinocilia are present just caudal to the eyes at these stages of development. However, careful observations and manipulations of the kinocilia of neuromasts in living tadpoles failed to find any evidence that kinocilia were embedded in a jelly-like cupula. We conclude that, when they first start to function, these early neuromasts detect water movements which directly move their freely exposed hair cell kinocilia projecting out from the skin surface. Possible behavioural roles for the tadpoles responses to water are discussed.
Nervous and humoral control of cardiac performance in the winter flounder(Pleuronectes americanus)
Authors: Mendonça Paula C. , Gamperl A. Kurt 
Published: March 2009

SUMMARYPrevious studies have suggested that flatfish lack adrenergic cardiac innervation and have a limited humoral adrenergic stress response. However,data on neurohormonal control of flatfish cardiac function is scarce, and has never been directly studied in vivo. Hence, we (1) injected neural and humoral antagonists into flounder (Pleuronectes americanus) in vivo to determine the contribution of autonomic innervation and circulating catecholamines to the control of resting cardiac function; (2)measured pre- and post-stress (90 s chase) catecholamine levels in this species; and (3) constructed in vivo catecholamine dose–response curves for cardiovascular function based on the results of the second experiment. In addition, we quantified the density(Bmax) and ligand-binding affinity(Kd) of flounder ventricular cell-surfaceβ-adrenoreceptors, and established whether they were ofβ 1 or β2 subtype using pharmacological antagonists. The cholinergic contribution to resting flounder heart rate was comparable to other teleosts (cholinergic tonus 26%). Interestingly, however,bretylium increased heart rate, resulting in a negative resting adrenergic tonus (–11.9%), and we were unable to demonstrate that catecholamines supported cardiac function at rest or at circulating concentrations approximating those following an exhaustive chase (adrenaline, 21 nmol l–1; noradrenaline, 14 nmol l–1). Myocardial Bmax was very high in the flounder (252.8 fmol mg–1 protein), and it appears that flounder ventricularβ-adrenoreceptors are predominantly of the β2 subtype[based on the inability of atenolol to displace [3H]CGP from theβ-adrenoreceptors, and the IC50 value for ICI 118551(1.91×10–6 mol l–1)]. However, the extremely low affinity (Kd 1.02 nmol l–1)for these receptors raises the possibility that the flounder heart is also populated by β3-adrenoreceptors.
Conversion of Alcohols to Alkyl Aryl Sulfides by a New Type of Oxidation–Reduction Condensation Using Phenyl Diphenylphosphinite
Authors: Kuroda Kiichi , Maruyama Yuji , Hayashi Yujiro , Mukaiyama Teruaki 
Published: March 2009

Abstract
Preparation of alkyl aryl sulfides from alcohols and arenethiols such as 2-sulfanyl-1,3-benzothiazole (BtzSH) is described by a new type of oxidation–reduction condensation using phenyl diphenylphosphinite (PhOPPh2) and benzoquinone derivatives or azide compounds. This reaction proceeds under mild and neutral conditions and is applicable to the thioetherification of various alcohols in which the chiral secondary and tertiary alcohols are converted into the corresponding chiral sulfides with almost complete inversion of configuration.
Tumor Cell Targeting Using Folate-Conjugated Fluorescent Quantum Dots and Receptor-Mediated Endocytosis
Authors: Song Er-Qun , Zhang Zhi-Ling , Luo Qing-Ying , Lu Wen , Shi Yun-Bo , Pang Dai-Wen 
Published: March 2009

Abstract
Background: Luminescent nanobioprobes with cell-targeting specificity are likely to find important applications in bioanalysis, biomedicine, and clinical diagnosis. Quantum dots (QDs) are unique and promising materials for such a purpose because of their fluorescence and large surface area for attaching cell-targeting molecules.
Methods: We produced water-dispersible QDs by coating hydrophobic QDs with small amphiphilic polyethylene glycol (PEG) molecules via hydrophobic interactions. We covalently coupled folate (FA) onto the water-dispersible PEG-coated QDs (PEG-QDs) to produce FA-coupled PEG-QDs (FA-PEG-QDs).
Results: These FA-PEG-QD nanoparticles functioned as fluorescent nanobioprobes that specifically recognized folate receptors (FRs) overexpressed in human nasopharyngeal cells (KB cells) but not in an FR-deficient lung carcinoma cell line (A549 cells). Using confocal fluorescence microscopy, we demonstrated uptake of FA-PEG-QDs by KB cells but no uptake of folate-free PEG-QDs. The specificity of this receptor-mediated internalization was confirmed by comparing the uptake by KB vs A549 cells.
Conclusions: Our results suggest that such cell-targeting fluorescent nanobioprobes are potentially very powerful tools for recognizing target cells and delivering and tracking drugs and other therapeutic materials.
Day 5 Morning Serum Cortisol Predicts Hypothalamic-Pituitary-Adrenal Function after Transsphenoidal Surgery for Pituitary Tumors
Authors: Jayasena Channa N , Gadhvi Kunal A , Gohel Bhavini , Martin Niamh M , Mendoza Nigel , Meeran Karim , Dhillo Waljit S 
Published: March 2009

Abstract
Background: Adrenal insufficiency is a complication of transsphenoidal surgery (TSS) for pituitary adenoma, and correct identification of patients requiring glucocorticoid replacement is important. Controversy exists over which early postoperative 9 AM cortisol concentration reliably predicts hypothalamic-pituitary-adrenal (HPA) axis reserve, as defined by the insulin tolerance test (ITT).
Methods: Data were reviewed for 36 patients undergoing TSS followed by day 5 postoperative 9 AM cortisol measurement and ITT 6 weeks postsurgery. All patients received postoperative glucocorticoid replacement, which was discontinued if the 9 AM serum cortisol was &gt;300 nmol/L.
Results: Of 23 patients who failed the ITT (peak cortisol &lt;500 nmol/L), 20 also had a day 5, 9 AM serum cortisol &lt;300 nmol/L. Nine of 13 patients who passed the ITT had a day 5, 9 AM cortisol &gt;300 nmol/L. The cutoff cortisol concentration of 300 nmol/L had 86.9% (66.4%–97.2%) diagnostic sensitivity, 69.2% (38.6%–90.9%) diagnostic specificity, and 83.3% (61.8%–94.5%) positive predictive value (PPV) for detecting secondary adrenal insufficiency. Increasing the cutoff to 392 nmol/L resulted in 100% (85.2%–100%) sensitivity, 46.1% (19.2%–74.9%) specificity, and 76.6% (57.3%–89.4%) PPV. Decreasing the cutoff to 111 nmol/L resulted in 100% (75.3%–100%) specificity and 100% (67.9%–100%) PPV, although sensitivity was 47.8% (26.8%–69.4%).
Conclusions: A day 5 post-TSS 9 AM serum cortisol &lt;111 nmol/L reliably detects secondary adrenal insufficiency, and concentrations &gt;392 nmol/L support intact HPA function. Because concentrations of 111–392 nmol/L are poorly predictive of HPA function, glucocorticoid replacement should continue in such cases until definitive testing is performed using an ITT.
Design and Evaluation of Two Laboratory Tests for the Nets of a Flexible Anchored Slope Stabilization System
Authors: Castro-Fresno Daniel , López Q. Luis , Blanco-Fernandez Elena , Zamora-Barraza David 
Published: March 2009

Abstract
This paper evaluates two new tests to characterize cable nets used in slope stabilization; a concentrated load test (CLT) and a distributed load test (DLT). These tests enable engineers to obtain the stress versus displacement graph and the maximum resistance. Both test devices and test methodology have been designed by the Construction Technology Research Group (GITECO) at the University of Cantabria. These two tests have enabled the certification of two different manufacturers of cable nets, Geobrugg and Malla Talud Cantabria (MTC). The results showed that these tests provide representative results of the net resistance. To verify the effectiveness of these new tests, they have been performed with various cable nets, from which homogeneous, logical results have been obtained, which are representative of the real working conditions. When performing the distributed load test, the force was applied to a pyramid of fine gravel sacks that enabled the forces to be distributed throughout the net. With this configuration, the net was deformed, acquiring an elliptical form in the lower free area. In the concentrated load test, the force was applied through a metallic plate of 600 mm diameter that deformed the net locally. The result always showed homogeneous behavior of the different samples tested. This allowed the test to be repeated in the same conditions several times. With the results of both tests an analysis was carried out relating the net grid, the load applied, and the displacement obtained. This enabled the generation of regression functions that provided information about the resistance value and the net displacement according to the chosen grid.
Role of Thiosulfate on Chloride Breakdown Potential of Heat Treated Ni-18Cr-6Fe Alloys
Authors: Ezuber Hosni M. 
Published: March 2009

Abstract
The breakdown potentials of mill-annealed Ni-18Cr-6Fe alloys were measured in wide range of chloride concentrations (0.001–1 M NaCl) and various concentrations of thiosulfate ranging from 0–0.25 M (Na2S2O3) at 80°C using the potentiodynamic technique. These potentials were compared with heat treated alloys for one or five hours at 900°C (and quenched). This work aimed to study the effect of sensitization on the pitting characteristics of this alloy in chloride-thiosulfate solutions. The anodic polarization curves revealed that sensitized alloys became more susceptible to chloride and thiosulfate pitting attack, or both. Addition of thiosulfate was potentially detrimental to chloride pitting resistance and the aggressiveness of thiosulfate species was found dependent on the ratio of chloride to thiosulfate concentration as the overall ionic strength is varied. A thiosulfate to chloride ratio of 1:40 (S2O2–3 / Cl–=0.025) was found be the most aggressive, regardless of ionic strength or heat treatment duration.
Der Bogen des Lebens
Authors: Bahr Hans-Dieter 
Published: March 2009

Zusammenfassung
Es geht hier nicht um die Selbigkeit des Umschlages von Lebendigem (zon) in Totes (tetnekos) und umgekehrt, von welcher Heraklit auch spricht, sondern um die zum Schwingen gebrachte Gespanntheit sterblichen Lebens. Das Wort ,Bogen' ruft  der Tat dieses Wortes nach  mit dem Leben dessen Tod zur Anwesenheit, und es wäre nicht Leben, wenn es nicht sterblich wäre. Der Bogen nennt sterbliches Leben, eine Sterblichkeit, die zum Verstehen ihrer selbst nur über den Unterschied zu dem gelangt, was nicht sterblich ist. Aber nun geht es nicht mehr um einen Gegensatz zwischen Sterblichem und Göttlichem, vielmehr wendet sich, im Schritt über die Sterblichkeit hinaus, das Leben zu dieser zurück. Mythisch allerdings wurde die Sterblichkeit zumal von der Unsterblichkeit im Sinne des Unvergänglichen her betrachtet und dadurch oft ihrem Wesen nach mehr verschattet als beleuchtet.
Leben und Erkenntnis. Über eine Entwicklung im Werk von Georges Canguilhem
Authors: Schmidgen Henning 
Published: March 2009

Zusammenfassung
1952 veröffentlicht der Philosoph und Wissenschaftshistoriker Georges Canguilhem die Aufsatzsammlung La connaissance de la vie. 1968 erscheint in seinen Etudes d′histoire et de philosophie des sciences ein Abschnitt mit dem Titel La nouvelle connaissance de la vie. Er enthält nur einen einzigen Beitrag, den grundlegenden Aufsatz Le concept et la vie. Die vorliegende Studie nimmt das Attribut nouvelle zum Anlaß, die auf Abstammungslinien von Begriffen ausgerichtete Wissenschaftsgeschichte von Canguilhem auf ihre Entwicklung in den Jahren zwischen 1950 und 1965 zu befragen. Es wird die These formuliert, dass Canguilhem in den sechziger Jahren, angesichts neuerer Entwicklungen in den Lebenswissenschaften (u.a. die Entdeckung der DNA-Struktur) und trotz einer durchgehend von Nietzsche inspirierten Sichtweise des Verhältnisses von Leben und Erkenntnis, eine Revision früherer Positionen vorgenommen hat: Während er das Erkenntnisproblem in den fünfziger Jahren vor allem auf eine Individualität des Verhaltens und Erlebens innerhalb einer bestimmten Umwelt bezieht und erkennen gleichsetzt mit analysieren, vermessen und berechnen, verbindet er es in späteren Jahren mit einer Kollektivität der Vererbung, der Transmission, Transkription und Expression von genetischer Information. Folgerichtig wird erkennen nunmehr definiert als sich informieren, sich üben im Entziffern und Dekodieren.
Die Kürze des Lebens und der Wunsch nach Ruhe
Authors: Bilstein Johannes 
Published: March 2009

Zusammenfassung
Der Beitrag setzt sich mit den traditionellen Topoi von der Kürze des Lebens und mit den in der gegenwärtigen Bildungspolitik erkennbaren Tendenzen und Parolen zur Beschleunigung und Effektivierung des Lebens auseinander. Dabei werden diesen einer ungebrochenen Fortschritts-Orientierung folgenden Tendenzen Argumentationsmuster der biographischen Vollendung entgegengesetzt.
Auch eine Poetik des Hörbuchs  Goethes Empfehlung des Vorlesens
Authors: Meyer-Kalkus Reinhart 
Published: March 2009

Zusammenfassung
Es ist die ironische Pointe im Leben eines Theaterdirektors, dass er nach über 20-jähriger Tätigkeit zur Einsicht gelangt, die wichtigsten Dramatiker der Weltliteratur wie Shakespeare und Calderón seien auf der Bühne eigentlich nicht spielbar, am besten würden sie vorgelesen. Goethe war dieser Theaterdirektor. Das Vorlesen dramatischer Teste erschien ihm nicht nur als Hilfsmittel der Proben oder als Ersatz für Theater-Aufführungen, sondern als eine eigene Kunstform, die geeignet ist, die Einbildungskraft des Zuhörers auf besondere Weise anzusprechen.
Lob der Wunderlichkeit. Lebensweisen und Life Sciences
Authors: Schulze Holger 
Published: March 2009

Zusammenfassung
Was ist Wunderlichkeit? Ausgehend von neurotischen Übersprungshandlungen oder Ticks zeigt sich wunderliches Verhalten als Riss in ansonsten perfekten Persone. Die statuarische Körper-Maske bricht auf (vgl. Michel Serres) und weist auf ein dynamischeres Konzept von Leben und Körper hin als das gegenwärtig vorherrschend medial dargestellte (vgl. Georges Canguilhem). Sind Freaks of Nature dann nicht der Normalfall? - Was, wenn Wunderlichkeit wiederum strategisch eingesetzt wird?
Kinetic and Mechanistic Investigations on Oxidation of L-tryptophan by Diperiodatocuprate(III) in Aqueous Alkaline Medium
Authors: Shetti Nagaraj P. , Nandibewoor Sharanappa T. 
Published: March 2009

AbstractThe oxidation of L-tryptophan (L-TRP) by diperiodatocuprate(III) (DPC) in aqueous alkaline medium at a constant ionic strength of 0.20 mol dm-3was studied spectrophotometrically at 298 K. The reaction between DPC and L-tryptophan in alkaline medium exhibits 1:4 stoichiometry (L-tryptophan: DPC). The reaction is of first order in [DPC] and has less than unit order in [L-TRP] and negative fractional order in [periodate] and [alkali]. Intervention of free radicals was observed in the reaction. The oxidation reaction in alkaline medium has been shown to proceed via a DPC- L-tryptophan complex, which decomposes slowly in a rate determining step followed by other fast steps to give the products. The main products were identified by spot test, IR,1H NMR,13CNMR and LC-MS spectral studies. The reaction constants involved in the different steps of the mechanism were calculated. The activation parameters with respect to slow step of the mechanism were computed and discussed and thermodynamic quantities were also determined.
The Evolution of Epistasis and Its Links With Genetic Robustness, Complexity and Drift in a Phenotypic Model of Adaptation
Authors: Gros Pierre-Alexis , Le Nagard Hervé , Tenaillon Olivier 
Published: March 2009

Abstract
The epistatic interactions among mutations have a large effect on the evolution of populations. In this article we provide a formalism under which epistatic interactions among pairs of mutations have a distribution whose mean can be modulated. We find that the mean epistasis is correlated to the effect of mutations or genetic robustness, which suggests that such formalism is in good agreement with most in silico models of evolution where the same pattern is observed. We further show that the evolution of epistasis is highly dependant on the intensity of drift and of how complex the organisms are, and that either positive or negative epistasis could be selected for, depending on the balance between the efficiency of selection and the intensity of drift.
Validation of Continuous Glucose Monitoring in Children and Adolescents With Cystic Fibrosis
Authors: O'Riordan Stephen M.P. , Hindmarsh Peter , Hill Nathan R. , Matthews David R. , George Sherly , Greally Peter , Canny Gerard , Slattery Dubhfeasa , Murphy Nuala , Roche Edna , Costigan Colm , Hoey Hilary 
Published: March 2009

OBJECTIVE
To validate continuous glucose monitoring (CGM) in children and adolescents with cystic fibrosis.

RESEARCH DESIGN AND METHODS
Paired oral glucose tolerance tests (OGTTs) and CGM monitoring was undertaken in 102 children and adolescents with cystic fibrosis (age 9.5–19.0 years) at baseline (CGM1) and after 12 months (CGM2). CGM validity was assessed by reliability, reproducibility, and repeatability.

RESULTS
CGM was reliable with a Bland-Altman agreement between CGM and OGTT of 0.81 mmol/l (95% CI for bias ± 2.90 mmol/l) and good correlation between the two (r = 0.74–0.9; P &lt; 0.01). CGM was reproducible with no significant differences in the coefficient of variation of the CGM assessment between visits and repeatable with a mean difference between CGM1 and CGM2 of 0.09 mmol/l (95% CI for difference ± 0.46 mmol/l) and a discriminant ratio of 13.0 and 15.1, respectively.

CONCLUSIONS
In this cohort of children and adolescents with cystic fibrosis, CGM performed on two occasions over a 12-month period was reliable, reproducible, and repeatable.