bluuebunny/crossref_metadata_2025_split huggingface dataset:
A method for deriving displacement data during cyclical movement using an inertial sensor
Authors: Pfau Thilo , Witte Thomas H. , Wilson Alan M. 
Published: June 2005

SUMMARY
Biomechanical studies often employ optical motion capture systems for the determination of the position of an object in a room-based coordinate system. This is not ideal for many types of study in locomotion since only a few strides may be collected per `trial', and outdoor experiments are difficult with some systems. Here, we report and evaluate a novel approach that enables the user to determine linear displacements of a proprietary orientation sensor during cyclical movement. This makes experiments outside the constraints of the laboratory possible, for example to measure mechanical energy fluctuations of the centre of mass during over-ground locomotion. Commercial orientation sensors based on inertial sensing are small and lightweight and provide a theoretical framework for determining position from acceleration. In practice,the integration process is difficult to implement because of integration errors, integration constants and the necessity to determine the orientation of the measured accelerations. Here, by working within the constraints of cyclical movements, we report and evaluate a method for determining orientation and relative position using a modified version of a commercial inertial orientation sensor that combines accelerometers, gyroscopes and magnetometers, thus giving a full set of movement parameters (displacement,velocity and acceleration in three dimensions). The 35 g sensor was attached over the spine of a horse exercising on a treadmill. During canter locomotion(9.0 m s-1), the amplitudes of trunk movement in the x(craniocaudal), y (mediolateral) and z (dorsoventral)directions were 99.6, 57.9 and 140.2 mm, respectively. Comparing sensor displacement values with optical motion capture values for individual strides,the sensor had a median error (25th, 75th percentile) in the x, y and z directions of 0.1 (–9.7, +10.8), –3.8(–15.5, +13.7) and –0.1 (–6.3, +7.1) mm, respectively. High-pass filtering of the displacement data effectively separated non-cyclical from cyclical components of the movement and reduced the interquartile ranges of the errors considerably to (–3.6, 6.2),(–4.0, 3.8) and (–4.5, 5.1) for x, y and z displacement, respectively, during canter locomotion. This corresponds to (–3.2, 5.5)%, (–6.7, 6.3)% and (–3.3, 3.7)%of the range of motion.
Regional and developmental variations of blood vessel morphometry in the chick embryo chorioallantoic membrane
Authors: Reizis Arava , Hammel Ilan , Ar Amos 
Published: June 2005

SUMMARY
Avian eggs contain all the necessary materials for embryonic development except for oxygen, which diffuses in from the environment via pores in the hard, calcified eggshell to the chorioallantoic membrane (CAM), the respiratory organ, which is rich in blood vessels. An air cell is formed at the blunt pole of the egg between the two membranes of the eggshell and enlarges during incubation due to water vapor loss. In this study of the CAM of chicken eggs, we compared blood vessel numerical density[NA(v)], area fraction of blood vessels[AA(v)], CAM thickness (DCAM), total length of blood vessels (L) and surface area of the CAM attached to the eggshell (CAMre) with those under the air cell(CAMac) during incubation. We found that NA(v), AA(v), DCAM and L of the CAM increase with embryonic age and development. The NA(v), AA(v) and L under the air cell were higher in relation to the rest of the CAM at all ages tested, while the DCAM under the air cell was always lower than around the rest of the egg. Since the eggshell over the air cell has a relatively greater porosity, and the respiratory gas exchange ratio there is higher than at other areas of the egg, there is a correlation between all the above morphometric data and the eggshell porosity. This suggests optimization of embryonic gas exchange in the chicken egg. We would like to propose that, during natural incubation, an increased gas diffusion under the air cell, together with increased blood vessel numerical density, may compensate for covering of the central part of the eggshell by the incubating parent.
Laminin and the malaria parasite's journey through the mosquito midgut
Authors: Arrighi Romanico B. G. , Lycett Gareth , Mahairaki Vassiliki , Siden-Kiamos Inga , Louis Christos 
Published: June 2005

SUMMARYDuring the invasion of the mosquito midgut epithelium, Plasmodiumookinetes come to rest on the basal lamina, where they transform into the sporozoite-producing oocysts. Laminin, one of the basal lamina's major components, has previously been shown to bind several surface proteins of Plasmodium ookinetes. Here, using the recently developed RNAi technique in mosquitoes, we used a specific dsRNA construct targeted against the LANB2 gene (laminin γ1) of Anopheles gambiae to reduce its mRNA levels, leading to a substantial reduction in the number of successfully developed oocysts in the mosquito midgut. Moreover, this molecular relationship is corroborated by the intimate association of developing P. berghei parasites and laminin in the gut, as observed using confocal microscopy. Our data support the notion of laminin playing a functional role in the development of the malaria parasite within the mosquito midgut.
Emperor penguins adjust swim speed according to the above-water height of ice holes through which they exit
Authors: Sato Katsufumi , Ponganis Paul J. , Habara Yoshiaki , Naito Yasuhiko 
Published: June 2005

SUMMARY
Emperor penguins leap from the water onto the sea ice. Their ability to reach above-water height depends critically on initial vertical speed of their leaping, assuming that the kinetic energy is converted to gravitational potential energy. We deliberately changed the above-water heights of ice hole exits, in order to examine whether penguins adjusted swim speed in accordance with the above-water height of the ice. Penguins were maintained in a corral on the fast ice in Antarctica, and voluntarily dived through two artificial ice holes. Data loggers were deployed on the penguins to monitor under water behavior. Nine instrumented penguins performed 386 leaps from the holes during experiments. The maximum swim speeds within 1 s before the exits through the holes correlated significantly with the above-water height of the holes. Penguins adopted higher speed to exit through the higher holes than through the lower holes. Speeds of some failed exits were lower than the theoretical minimum values to reach a given height. Penguins failed to exit onto the sea ice in a total of 37 of the trials. There was no preference to use lower holes after they failed to exit through the higher holes. Rather, swim speed was increased for subsequent attempts after failed leaps. These data demonstrated that penguins apparently recognized the above-water height of holes and adopted speeds greater than the minimal vertical speeds to reach the exit height. It is likely, especially in the case of higher holes (&gt;40 cm), that they chose minimum speeds to exit through the holes to avoid excess energy for swimming before leaping. However, some exceptionally high speeds were recorded when they directly exited onto the ice from lower depths. In those cases,birds could increase swim speed without strokes for the final seconds before exit and they only increased the steepness of their body angles as they surfaced, which indicates that the speed required for leaps by emperor penguins were aided by buoyancy, and that penguins can sometimes exit through the ice holes without any stroking effort before leaping.
The metabolic cost of egg production is repeatable
Authors: Vézina François , Williams Tony D. 
Published: June 2005

SUMMARYThe metabolic cost of egg production in birds (passerines) has been measured as a 16–27% increase in basal or resting metabolic rate (BMR and RMR, respectively) when comparing non-breeding values with those in egg-producing individuals. However, available data to date have been obtained in free-living birds and may thus be confounded by the effect of variable ecological conditions on non-reproductive physiological machinery (organ mass or metabolic activity) which might contribute to measured variation in RMR. Here, we show that in captive, controlled conditions, the process of egg formation induces a 22% increase in RMR in female zebra finches Taeniopygia guttata. Among individuals, variation in laying RMR is independent of egg mass, clutch size or total clutch mass. Importantly, we show that individual variation in both non-breeding and laying RMR is repeatable over periods of at least 8-10 months, i.e. individual variation in RMR remained constant over time for any given physiological state. This suggests that the metabolic cost of egg formation should respond to selection. However, we also show that in males, but not females, repeatability of RMR declines over time even when birds are kept in constant controlled conditions.
Burst characteristics of daily jaw muscle activity in juvenile rabbits
Authors: van Wessel T. , Langenbach G. E. J. , Kawai N. , Brugman P. , Tanaka E. , van Eijden T. M. G. J. 
Published: June 2005

SUMMARY
Muscle activation varies with different behaviors and can be quantified by the level and duration of activity bursts. Jaw muscles undergo large anatomical changes during maturation, which are presumably associated with changes in daily muscle function. Our aim was to examine the daily burst number, burst length distribution and duty time (fraction of the day during which a muscle was active) of the jaw muscles of juvenile male rabbits(Oryctolagus cuniculus). A radio-telemetric device was implanted to record muscle activity continuously from the digastric, superficial and deep masseter, medial pterygoid and temporalis during maturation week 9-14. Daily burst characteristics and duty times were determined for activations,including both powerful and non-powerful motor behavior. All muscles showed constant burst numbers, mean burst lengths and duty times during the recording period. Including all behavior, the temporalis showed significantly larger daily burst numbers (205 000) and duty times (18.2%) than the superficial and deep masseter (90 000; 7.5%). Burst numbers and duty times were similar for the digastric (120 000; 11.1%) and medial pterygoid (115 000; 10.4%). The temporalis and deep masseter showed many short low activity bursts (0.05 s),the digastric showed many long bursts (0.09 s). For activations during powerful behaviors the superficial masseter and medial pterygoid had the largest burst numbers and duty times. Both muscles showed similar burst characteristics for all activation levels. It was concluded that activation of the jaw muscles is differently controlled during powerful and non-powerful motor behaviors and the functional organization of motor control patterns does not vary from 9 to 14 weeks of age.
Do seasonal changes in metabolic rate facilitate changes in diving behaviour?
Authors: Green J. A. , Boyd I. L. , Woakes A. J. , Green C. J. , Butler P. J. 
Published: June 2005

SUMMARYMacaroni penguins were implanted with data loggers to record heart rate(fh), abdominal temperature (Tab) and diving depth during their pre-moult trip (summer) and winter migration. The penguins showed substantial differences in diving behaviour between the seasons. During winter, mean and maximum dive duration and dive depth were significantly greater than during summer, but the proportion of dives within the calculated aerobic dive limit (cADL) did not change.Rates of oxygen consumption were estimated from fh. As winter progressed, the rate of oxygen consumption during dive cycles(sV̇O2DC) declined significantly and mirrored the pattern of increase in maximum duration and depth. The decline in sV̇O2DC was matched by a decline in minimum rate of oxygen consumption(sV̇O2min). When sV̇O2min was subtracted from sV̇O2DC, the net cost of diving was unchanged between summer and winter. We suggest that the increased diving capacity demonstrated during the winter was facilitated by the decrease in sV̇O2min.Abdominal temperature declined during winter but this was not sufficient to explain the decline in sV̇O2min. A simple model of the interactions between sV̇O2min, thermal conductance and water temperature shows how a change in the distribution of fat stores and therefore a change in insulation and/or a difference in foraging location during winter could account for the observed reduction in sV̇O2min and hence sV̇O2DC.
Low temperature acclimated populations of the grain aphidSitobion avenaeretain ability to rapidly cold harden with enhanced fitness
Authors: Powell S. J. , Bale J. S. 
Published: June 2005

SUMMARYIn contrast to previous studies of rapid cold-hardening (RCH), which have investigated the responses of insects maintained under `summer conditions'(20° to 25°C), this study focuses on the ability of low-temperature acclimated insects to undergo RCH. When the grain aphid Sitobion avenae Fabricus was low-temperature acclimated by rearing for three generations at 10°C, the discriminating temperatures (temperature that results in approximately 20% survival after direct transfer from the rearing temperature to a sub-zero temperature for a period of 3 h), of first instar nymphs and adult aphids were –11.5° and –12°C,respectively. Maximum rapid cold-hardening was induced by cooling aphids at 0°C for 2 h (nymphs) or 30 min (adults), resulting in survival at the respective discriminating temperatures increasing from 26% to 96% (nymphs) and 22% to 70% (adults). Cooling from 10° to 0°C at 1°, 0.1° and 0.05°C min-1 significantly increased survival of nymphs at the discriminating temperature, but not of adults. There were no `ecological costs' associated with rapid cold-hardening at 0°C, or with exposure of rapidly cold-hardened aphids to the discriminating temperatures; fecundity and longevity, in both nymphs and adults were either similar to control aphids or significantly increased. The study demonstrates that rapid cold-hardening ability is retained in aphids that have already undergone cold-acclimation, as would be the case in overwintering aphids. Both rapid cold-hardening and subsequent exposure at previously lethal temperatures can enhance fitness in surviving individuals.
Preclinical Evaluation of a Novel Water‐soluble Chlorin E6 Derivative (BLC 1010) as Photosensitizer for the Closure of the Neovessels
Authors: Pegaz B. , Debefve E. , Borle F. , Ballini J.‐P. , Wagnières G. , Spaniol S. , Albrecht V. , Scheglmann D. , Nifantiev N. E. , van den Bergh H. , Konan Y. N. 
Published: June 2005

ABSTRACTIn the present study, photodynamic activity of a novel photosensitizer (PS), Chlorin e6‐2.5 N‐methyl‐d‐glucamine (BLC 1010), was evaluated using the chorioallantoic membrane (CAM) as an in vivo model. After intravenous (i.v.) injection of BLC 1010 into the CAM vasculature, the applicability of this drug for photodynamic therapy (PDT) was assessed in terms of fluorescence pharmacokinetics, i.e. leakage from the CAM vessels, and photothrombic activity. The influence of different PDT parameters including drug and light doses on the photodynamic activity of BLC 1010 has been investigated. It was found that, irrespective of drug dose, an identical continuous decrease in fluorescence contrast between the drug inside and outside the blood vessels was observed. The optimal treatment conditions leading to desired vascular damage were obtained by varying drug and light doses. Indeed, observable damage was achieved when irradiation was performed at light doses up to 5 J/cm2 1 min after i.v. injection of drug doses up to 0.5 mg/kg body weight(b.w.). However, when irradiation with light doses of more than 10 J/cm2 was performed 1 min after injection of drug doses up to 2 mg/kg body weight, this led to occlusion of large blood vessels. It has been demonstrated that it is possible to obtain the desired vascular occlusion and stasis with BLC 1010 for different combinations of drug and/or light doses.
Geographic Patterns of Disease
Authors: Elliott Paul , Best Nicola 
Published: June 2005

AbstractThe study of geographic variations in disease is a classic epidemiological technique in which location is used as a surrogate for the mix of lifestyle, environmental, and possibly genetic factors that may underlie variations in rates of disease across populations. This article reviews issues involved in disease mapping (the usual means of presenting descriptive geographic data on disease occurrence) and geographic correlation studies (where the aim is to explore geographic variation in disease in terms of underlying spatially varying “risk factors”). The emphasis is on small‐area applications, where a number of recent advances in methodology have been made.
Membranes, Hollow‐Fiber
Authors: Moch Irving 
Published: June 2005

AbstractHollow‐fiber membranes were invented in the 1960s. In the ensuing decades much research and development effort has transpired with the result that these fibers have become exceedingly important to industry, academia, and government in such fields as desalination of water, wastewater reclamation, medicine, agriculture, gas separation, and pervaporation. Commercial opportunities annually exceed several hundred million dollars. The hollow‐fiber membranes are usually the base technology within a significantly larger system.This article briefly discusses the history and theory of hollow‐fiber membrane technology. Methods of manufacture are reviewed together with processing techniques employed to enhance various aspects of performance. Hollow‐fiber membranes are composed of many different materials of construction. The generic compositions are cited and specific end use applications noted. Lastly, the work to date has identified many areas where future prospects for hollow‐fiber membranes are the brightest. A number of these future growth areas are discussed together with which industrial corporations are in the forefront of the new developments.
Heat Exchanger Network Design
Authors: Polley Graham , Mukherjee Rajiv 
Published: June 2005

AbstractThis article addresses the problem of heat‐exchanger network design. The design of such systems can no longer be done in isolation from consideration of alternative means of energy conservation, and most importantly, from consideration of how the design of the heat recovery system interacts and impinges on the design of the core of the process and the utility system.This article gives details on the economics of heat recovery: how to determine the energy demand; how to determine approximate capital cost; how to identify economic heat recovery level. The Pinch Design Method is discussed as a means to determine these economic factors. This method is discussed in detail from the basic principles to a worked example and shortcomings of the method are described. Systematic problem decomposition is one way to overcome the shortcomings. Many software packages are available to implement Pinch technology, but the reader is urged to develop a basic understanding of the principles of the technology and use this in combination with engineering judgement. Finally a practical design application is detailed.
Lysozyme fibrillation: Deep UV Raman spectroscopic characterization of protein structural transformation
Authors: Xu Ming , Ermolenkov Vladimir V. , He Wei , Uversky Vladimir N. , Fredriksen Laura , Lednev Igor K. 
Published: June 2005

AbstractDeep ultraviolet resonance Raman spectroscopy was demonstrated to be a powerful tool for structural characterization of protein at all stages of fibril formation. The evolution of the protein secondary structure as well as the local environment of phenylalanine, a natural deep ultraviolet Raman marker, was documented for the fibrillation of lysozyme. Concentration‐independent irreversible helix melting was quantitatively characterized as the first step of the fibrillation. The native lysozyme composed initially of 32% helix transforms monoexponentially to an unfolded intermediate with 6% helix with a characteristic time of 29 h. The local environment of phenylalanine residues changes concomitantly with the secondary structure transformation. The phenylalanine residues in lysozyme fibrils are accessible to solvent in contrast to those in the native protein. © 2005 Wiley Periodicals, Inc. Biopolymers 79: 58–61, 2005This article was originally published online as an accepted preprint. The “Published Online” date corresponds to the preprint version. You can request a copy of the preprint by emailing the Biopolymers editorial office at biopolymers@wiley.com
Characterization of the nonregular regions of proteins by a contortion index
Authors: De Subhajyoti , Sur Kunal , Dasgupta Swagata 
Published: June 2005

AbstractNonstructured regions in proteins that provide the link between two regular structured regions play a significant role in maintaining the scaffold of the protein. Not only do they act as connectors between two regular secondary structural elements of proteins but they also provide the necessary turn or reversal in the polypeptide chain. This incorporates flexibility in the structure. Thus an understanding of the structural aspects of the nonregular regions is necessary to have a better insight into these features. We can assume the nonregular region to be a contorted polypeptide segment tethered by regular secondary structured regions at both ends. To describe the undulating nature of the nonregular regions, we introduce a parameter called the “contortion index.” This index describes how tortuously the region is organized. Our analysis shows that the contortion index is related to other physicochemical parameters and can be used to characterize the nonregular regions of proteins. © 2005 Wiley Periodicals, Inc. Biopolymers 79: 63–73, 2005This article was originally published online as an accepted preprint. The “Published Online” date corresponds to the preprint version. You can request a copy of the preprint by emailing the Biopolymers editorial office at biopolymers@wiley.com
Ethics of palliative surgery in patients with cancer
Authors: Hofmann B , Håheim L L , Søreide J A 
Published: June 2005

AbstractBackgroundSurgery is an important palliative method for patients with advanced malignant disease. In addition to concerns related to clinical decision making, various moral challenges are encountered in palliative surgery. Some of these relate to the patients and their illness, others to the surgeons, their attitudes, skills and knowledge base.Method and resultsPertinent moral challenges are addressed and analysed with respect to prevailing perspectives in normative ethics. The vulnerability of patients with non-curable cancer calls for moral awareness. Demands regarding sensibility and precaution in this clinical setting represent substantial challenges with regard to the ‘duty to help’, benevolence, respect of autonomy and proper patient information. Moreover, variations in definition of palliative surgery as well as limited scientific evidence with respect to efficacy, effectiveness and efficiency pose methodological and moral problems. Therefore, a definition of palliative surgery that addresses these issues is provided.ConclusionBoth surgical skill and much moral sensibility are required to improve palliative care in surgical oncology. This should be taken into account not only in clinical practice but also in education and research.