bluuebunny/crossref_metadata_2025_split huggingface dataset:
Developmental plasticity of physiology and morphology in diet-restricted European shag nestlings (Phalacrocorax aristotelis)
Authors: Moe Børge , Brunvoll Siri , Mork Daniel , Brobakk Trond Einar , Bech Claus 
Published: October 2004

SUMMARYGrowing animals may exhibit developmental plasticity as an adaptation to variability in the environmental conditions during development. We examined physiological and morphological responses to short-term food shortage of 12–16-day-old European shag nestlings kept under laboratory conditions. After 4 days on a weight maintenance diet, the resting metabolic rate (RMR) of diet-restricted nestlings was 36.5% lower compared with control fed nestlings,after controlling for body mass. This response was accompanied by a reduction in body temperature (Tb) and by reductions in the size of several visceral organs, muscles and lipid stores, while the overall structural growth was maintained almost in line with the age-specific growth rate of controls. Hence, the pattern of energy allocation reflected a very high priority to structural growth at the expense of visceral organs, lipid deposits and muscles. The reduced Tb and size of the liver served as important physiological processes behind the observed reductions in RMR. We discuss the possible adaptive significance of this differential developmental plasticity during temporal food shortage. This is the first study of avian developmental plasticity to report substantial energy saving in combination with a high structural growth rate.
Kinematics of aquatic and terrestrial escape responses in mudskippers
Authors: Swanson Brook O. , Gibb Alice C. 
Published: October 2004

SUMMARY
Escape responses in fishes are rapid behaviors that are critical for survival. The barred mudskipper (Periophthalmus argentilineatus) is an amphibious fish that must avoid predators in two environments. We compared mudskipper terrestrial and aquatic escapes to address two questions. First,how does an amphibious fish perform an escape response in a terrestrial environment? Second, how similar is a terrestrial escape response to an aquatic escape response? Because a mudskipper on land does not have to contend with the high viscosity of water, we predicted that, if the same behavior is employed across environments, terrestrial escape responses should have`better' performance (higher velocity and more rapid completion of movements)when compared with aquatic escape responses. By contrast, we predicted that intervertebral bending would be similar across environments because previous studies of escape response behaviors in fishes have proposed that vertebral morphology constrains intervertebral bending. High-speed digital imaging was used to record mudskipper escapes in water and on land, and the resulting images were used to calculate intervertebral bending during the preparatory phase, peak velocity and acceleration of the center of mass during the propulsive phase, and relative timing of movements. Although similar maximum velocities are achieved across environments, terrestrial responses are distinct from aquatic responses. During terrestrial escapes, mudskippers produce greater axial bending in the preparatory phase, but only in the posterior region of the body and over a much longer time period. Mudskippers also occasionally produced the `wrong' behavior for a given environment. Thus,it appears that the same locomotor morphology is recruited differently by the central nervous system to produce a distinct behavior appropriate for each environment.
The role of drag in insect hovering
Authors: Wang Z. Jane 
Published: October 2004

SUMMARYStudies of insect flight have focused on aerodynamic lift, both in quasi-steady and unsteady regimes. This is partly influenced by the choice of hovering motions along a horizontal stroke plane, where aerodynamic drag makes no contribution to the vertical force. In contrast, some of the best hoverers– dragonflies and hoverflies – employ inclined stroke planes,where the drag in the down- and upstrokes does not cancel each other. Here,computation of an idealized dragonfly wing motion shows that a dragonfly uses drag to support about three quarters of its weight. This can explain an anomalous factor of four in previous estimates of dragonfly lift coefficients,where drag was assumed to be small.To investigate force generation and energy cost of hovering flight using different combination of lift and drag, I study a family of wing motion parameterized by the inclined angle of the stroke plane. The lift-to-drag ratio is no longer a measure of efficiency, except in the case of horizontal stroke plane. In addition, because the flow is highly stalled, lift and drag are of comparable magnitude, and the aerodynamic efficiency is roughly the same up to an inclined angle about 60°, which curiously agrees with the angle observed in dragonfly flight.Finally, the lessons from this special family of wing motion suggests a strategy for improving efficiency of normal hovering, and a unifying view of different wing motions employed by insects.
Adjusting muscle function to demand: joint work during acceleration in wild turkeys
Authors: Roberts Thomas J. , Scales Jeffrey A. 
Published: October 2004

SUMMARY
We measured the net work performed at hind limb joints in running turkeys to determine the source of mechanical power for acceleration. We tested the hypothesis that net mechanical work per step increases in proportion to acceleration at all four major hind limb joints (hip, knee, ankle and tarsometatarsal–phalangeal joint). This hypothesis was based on the idea that all hind limb muscles should contribute mechanical work to maximize performance during accelerations, and a previous study that indicated the mechanical power output of the entire turkey hind limb musculature was remarkably high. We used high-speed video and force-plate measurements to measure joint moment, velocity and power output during single foot-contacts of running accelerations. By measuring steps in which the animals were relatively more or less motivated to accelerate, we obtained data for a range of accelerations, all at approximately the same running speed. Net joint work per step increased at the hip and ankle as a function of acceleration. Hip net work per unit body mass was 0.12±0.09 J kg-1 averaged over the five lowest accelerations (–0.22±0.08 m s-2), and 0.87±0.20 J kg-1 for the five highest accelerations(4.86±0.27 m s-2). Ankle work was –0.21±0.11 J kg-1 for the lowest accelerations and 0.71±0.28 J kg-1 for the highest. The high work output at the ankle is consistent with the idea that elastic mechanisms function to increase muscle work during acceleration. The work performed at the knee and tarsometatarsal–phalangeal joint was independent of acceleration in a step. These results support the idea that hip and ankle extensors contribute significantly to the work necessary to accelerate the body.
We also measured the change in joint moment and angular excursion with acceleration to determine whether the mechanism for increasing work output at a joint involved an increase in muscle force or muscle shortening. The increase in joint work at the hip and ankle resulted almost entirely from an increase in joint angular excursion during stance. Hip extension increased by more than threefold from the lowest to the highest accelerations, and the angular excursion of the ankle increased from –24.8±4.7° (net flexion) at the lowest accelerations to 33.0±12.8° (net extension)at the highest accelerations. Mean stance joint moment was unchanged with acceleration at the ankle and increased by approximately 35% at the hip across the range of accelerations. These patterns of joint moment and excursion indicate that turkeys increase mechanical work for acceleration primarily by increasing muscle shortening, rather than muscle force.
Inflation of the esophagus and vocal tract filtering in ring doves
Authors: Riede Tobias , Beckers Gabriël J. L. , Blevins William , Suthers Roderick A. 
Published: October 2004

SUMMARYRing doves vocalize with their beaks and nostrils closed, exhaling into inflatable chambers in the head and neck region. The source sound produced at the syrinx contains a fundamental frequency with prominent second and third harmonic overtones, but these harmonics are filtered out of the emitted signal. We show by cineradiography that the upper esophagus, oral and nasal cavities collect the expired air during vocalization and that the inflated esophagus becomes part of the suprasyringeal vocal tract. The level of the second and third harmonics, relative to the fundamental frequency(f0), is reduced in the esophagus and emitted vocalization compared with in the trachea, although these harmonics are still considerably higher in the esophagus than in the emitted signal. When the esophagus is prevented from fully inflating, there is a pronounced increase in the level of higher harmonics in the emitted vocalization. Our data suggest that the trachea and esophagus act in series as acoustically separate compartments attenuating harmonics by different mechanisms. We hypothesize that the trachea behaves as a tube closed at the syringeal end and with a variable, restricted opening at the glottal end that lowers the tracheal first resonance to match the f0 of the coo. The inflated esophagus may function as a Helmholtz resonator in which the elastic walls form the vibrating mass. Such a resonator could support the f0 over a range of inflated volumes.
Why do macaroni penguins choose shallow body angles that result in longer descent and ascent durations?
Authors: Sato Katsufumi , Charrassin Jean-Benol̂t , Bost Charles-André , Naito Yasuhiko 
Published: October 2004

SUMMARYIt is generally assumed that air-breathing aquatic animals always choose the shortest route to minimize duration for transit between the surface and foraging depth in order to maximize the proportion of time spent foraging. However, empirical data indicate that the body angles of some diving animals are rarely vertical during descent and ascent. Why do they choose shallower body angles that result in longer descent and ascent durations? To investigate this question, we attached acceleration data loggers to eight female macaroni penguins, breeding on the Kerguelen Islands(48°45′–50°00′S,68°45′–70°58′E; South Indian Ocean), to record depth, two-dimensional acceleration (stroke cycle frequency and body angle)and temperature. We investigated how they controlled body angle and allocated their submerged time. The instrumented females performed multiple dives(N=6952) with a mean dive depth for each bird ranging from 24.5±28.5 m to 56.4±75.1 m. Mean body angles during descent and ascent were not vertical. There was large variation in mean descent and ascent angles for a given dive depth, which, in turn, caused large variation in descent and ascent duration. Body angles were significantly correlated with time spent at the bottom-phase of the dive. Birds that spent long periods at the bottom exhibited steep body angles during ascent and subsequent descent. By contrast, they adopted shallow body angles after they had short or no bottom phases. Our results suggest that macaroni penguins stay at the bottom longer after encountering a good prey patch and then travel to the surface at steep body angles. If they do not encounter prey, they discontinue the dive,without staying at the bottom, ascend at shallow body angles and descend at shallow body angles in a subsequent dive. A shallow body angle can increase the horizontal distance covered during a dive, contributing to the move into a more profitable area in the following dive. During the ascent, in particular,macaroni penguins stopped beating their flippers. The buoyantly gliding penguins can move horizontally with minimum stroking effort before reaching the surface.
The Fine Structure of Galls in Phylogenetic Networks
Authors: Gusfield Dan , Eddhu Satish , Langley Charles 
Published: October 2004

A phylogenetic network is a generalization of a phylogenetic tree, allowing properties that are not tree-like. With the growth of genomic data, much of which does not fit ideal tree models, there is greater need to understand the algorithmics and combinatorics of phylogenetic networks (Posada and Crandall 2001, Schierup and Hein 2000).Wang et al. (2001) studied the problem of constructing a phylogenetic network for a set of n binary sequences derived from the all-zero ancestral sequence, when each site in the sequence can mutate from zero to one at most once in the network, and recombination between sequences is allowed. They showed that the problem of minimizing the number of recombinations in such networks is NP-hard, but introduced a special case of the problem, i.e., to determine whether the sequences could be derived on a phylogenetic network where the recombination cycles are node-disjoint. Wang et al. (2001) provide a sufficient, but not a necessary test, for such solutions. Gusfield et al. (2003, 2004) gave a polynomial-time algorithm that is both a necessary and sufficient test. In this paper, we study in much more detail the fine combinatorial structure of node-disjoint cycles in phylogenetic networks, both for purposes of insight into phylogenetic networks and to speed up parts of the previous algorithm. We explicitly characterize all the ways in which mutations can be arranged on a disjoint cycle, and prove a strong necessary condition for a set of mutations to be on a disjoint cycle.The main contribution here is to show how structure in the phylogenetic network is reflected in the structure of an efficiently-computable graph, called the conflict graph. The success of this approach suggests that additional insight into the structure of phylogenetic networks can be obtained by exploring structural properties of the conflict graph.
DSS Effectiveness in Marketing Resource Allocation Decisions: Reality vs. Perception
Authors: Lilien Gary L. , Rangaswamy Arvind , Van Bruggen Gerrit H. , Starke Katrin 
Published: October 2004

We study the process by which model-based decision support systems (DSSs) influence managerial decision making in the context of marketing budgeting and resource allocation. We focus on identifying whether and how DSSs influence the decision process (e.g., cognitive effort deployed, discussion quality, and decision alternatives considered) and, as a result, how these DSSs influence decision outcomes (e.g., profit and satisfaction both with the decision process and the outcome). We study two specific marketing resource allocation decisions in a laboratory context: sales effort allocation and customer targeting. We find that decision makers who use high-quality, model-based DSSs make objectively better decisions than do decision makers who only have access to a generic decision tool (Microsoft Excel). However, their subjective evaluations (perceptions) of both their decisions and the processes that lead to those decisions do not necessarily improve as a result of DSS use. And expert judges, serving as surrogates for top management, have a difficult time assessing the objective quality of those decisions. Our results suggest that what managers get from a high-quality DSS may be substantially better than what they see. To increase the inclination for managerial adoption and use of DSS, we must get users to “see” the benefits of using a DSS. Our results also suggest two ways to bridge the perception-reality gap: (1) improve the perceived value of the decision process by designing DSSs both to encourage discussion (e.g., by providing explanation and support for alternative recommendations) as well as to reduce the perceived complexity of the problem so that managers invest more cognitive effort in exploring additional options and (2) provide feedback on the likely market/business outcomes of various decision options.
Large Differences in Laboratory Utilisation between Hospitals in Sweden
Authors: Larsson Anders , Palmer Mats , Hultén Göran , Tryding Nils 
Published: October 2004

Abstract
There are large differences in the use of laboratory tests between hospitals in Sweden. These differences are not only due to differences between the patients treated but also to differences in practice. Use of laboratory test seems to reflect local traditions to a large extent. These large variations in practice are not compatible with the objective of providing care on equal terms and reduce the cost-effectiveness of clinical chemistry.
Recently, several intervention studies have been performed in Sweden with the aim to optimise the use of clinical chemistry tests in primary care. The results show that it is possible to reduce the cost in primary care by SEK 100 million per year while increasing the clinical usefulness. This constitutes approximately 10% of the total cost for clinical chemistry tests in primary care. It should also be possible to reduce the cost for clinical chemistry tests in secondary and tertiary care. Hospitals order more tests than primary care and the potential savings are thus greater.
We have studied the ordering habits for eleven Swedish hospitals. The comparison was made in the form of ratios between related laboratory tests to reduce the effects of differences in size between the studied laboratories. The large variation between hospitals indicates that a continuous discussion between the clinicians and the laboratories could reduce the cost. We have used the figures from the comparison and calculated the potential savings for seven frequently used tests. The potential yearly saving in Sweden for these tests is approximately SEK 150 million.
Development of a Method for Rapid Quantitation of Amino Acids by Liquid Chromatography-Tandem Mass Spectrometry (LC-MSMS) in Plasma
Authors: Casetta Bruno , Tagliacozzi Debora , Shushan Bori , Federici Giorgio 
Published: October 2004

Abstract
A new analytical method has been developed and is proposed for the rapid determination of eighteen common amino acids, including tryptophan, in plasma and dried blood spots, by liquid chromatography coupled with ionspray tandem mass spectrometry. Potentially the method can include other amino acids and can be used for the diagnosis of metabolic disease. The use of the ionspray tandem mass spectrometry approach permits extremely rapid chromatographic separation of all amino acids requiring less than four minutes for the analysis of each sample, after a simple sample preparation procedure. The chromatographic separation of the analytes was achieved using a CN normal phase column and a water/acetonitrile/trifluoroacetic acid mobile phase at flow rate of 1 ml/min. The mass spectrometer was operated in multiple reaction monitoring mode, where each analyte had its own unique precursor and product ion setting. The quantitative analysis of amino acids was achieved using as internal standards just two representative isotopically labeled amino acids: D4-Ala and D5-Phe. Calibration is made externally by using aqueous solutions with the same labelled amino acids as internal standards. The high specificity of tandem mass spectrometry coupled with a fast chromatographic process is suitable for the rapid and reliable assay of metabolically significant amino acids. The liquid chromatography-tandem mass spectrometry method is more effective than other published tandem mass spectrometry methods at distinguishing isobaric amino acids like Leu, Ile and HO-Pro and certainly far more rapid than HPLC or ion-exchange chromatographic methods.
Adhesion Molecule Behavior during Rejection and Infection Episodes after Heart Transplantation
Authors: Weigel Günter , Grimm Michael , Griesmacher Andrea , Seebacher Gernot , Sichrovsky Tina , Wolner Ernst , Laufer Günter , Müller Mathias M. 
Published: October 2004

AbstractIn cardiac transplant recipients the release of soluble cellular adhesion molecules intercellular adhesion molecule-1 (ICAM-1), vascular cell adhesion molecule-1 (VCAM-1) and E-Selectin into serum is pronounced during immune activation. It is uncertain whether there is a specific pattern of release during infection or cardiac allograft rejection. In a prospective study, 30 consecutive cardiac allograft recipients were followed for a median period of 11.4 months (range 1–34). Soluble ICAM-1 (sICAM-1), soluble VCAM-1 (sVCAM-1) and soluble E-Selectin (sE-Selectin) were measured in addition to acute phase proteins (C-reactive protein, α1-antitrypsin), complement factors (C3, C4) and β2-microglobulin. The measured serum levels were correlated with the clinical status of the transplant recipient: 1) uneventful clinical status; 2) asymptomatic infection; 3) symptomatic infection and 4) rejection. Forty age-matched healthy subjects served as controls. Six days before biopsy-proven cardiac allograft rejection sICAM-1-release started to increase (p < 0.05) as compared to uneventful clinical status. The peak concentration of sICAM-1 was measured three days before rejection. On the day of rejection, serum concentrations of sICAM-1 (p < 0.001) and sVCAM-1 (p < 0.05) were increased, whereas sE-Selectin was not markedly elevated. In symptomatic infections, the serum concentrations of sICAM-1 (p < 0.001) and sVCAM-1 (p < 0.05) were elevated at the day of diagnosis and both parameters reached peak levels three days after onset of chemotherapy. In multivariate analysis soluble adhesion molecules only weakly discriminated between rejection and infection (sensitivity: 13%, specificity: 95%). Although, in combination with routine blood parameters the discriminatory power could be improved (sensitivity: 85%, specificity: 85%) the clinical utility of these markers in non-invasive monitoring is limited.
Concentration of Lp(a) and other Apolipoproteins in Predialysis, Hemodialysis, Chronic Ambulatory Peritoneal Dialysis and Post-Transplant Patients
Authors: Kimak Elzbieta , Solski Janusz , Janicka Lucyna , Ksaziek Andrzej , Janicki Krzysztof 
Published: October 2004

Abstract
Serum levels of lipids, lipoprotein(a) Lp(a) and other apolipoproteins were determined in 47 predialysis patients, 40 hemodialysis (HD) patients, 39 chronic ambulatory peritoneal dialysis (CAPD) patients, 11 patients after kidney transplantation and 47 healthy subjects as reference group.
The predialysis, HD, and CAPD patients had disturbances in the concentration of serum triglyceride (TG), high density lipoprotein (HDL)-cholesterol, apolipoprotein AI (apoAI), total apoCIII, apoCIII present in the particles without apoB (apoCIII non B), and Lp(a) and HDL-cholesterol, low density lipoprotein (LDL)-cholesterol/HDL-cholesterol, HDL-cholesterol/apoAI, apoAI/apoB, and apoAI/apoCIII ratios. Predialysis patients had significantly lower concentrations of HDL-cholesterol and total apoE levels than CAPD patients and total apoE level than HD patients.
Moreover, both HD and CAPD patients had significantly increased levels of apoB containing apoE (apoB:E) and apoB containing apoCIII (apoB:CIII). The concentrations of serum TG, total cholesterol, LDL-cholesterol, apoB, Lp(a) in CAPD patients were statistically higher than in HD patients. The patients after transplantation demonstrated normalization of lipid and lipoprotein parameters and lipoprotein ratios except serum levels of TG, total apoCIII, apoCIII non B and the apoAI/apoCIII ratio.
We concluded that abnormal lipid and lipoprotein concentrations in patients with uremia may be the cause of their high risk of atherosclerosis, but post-transplant patients exhibited improved levels of serum lipids, Lp(a) and other lipoprotein parameters and lipoprotein composition, which could be an index of decreased atherogenic status.