bluuebunny/crossref_metadata_2025_split huggingface dataset:
Fluid dynamics of feeding behaviour in white-spotted bamboo sharks
Authors: Nauwelaerts Sandra , Wilga Cheryl D. , Lauder George V. , Sanford Christopher P. 
Published: September 2008

SUMMARYAlthough the motor control of feeding is presumed to be generally conserved, some fishes are capable of modulating the feeding behaviour in response to prey type and or prey size. This led to the `feeding modulation hypothesis', which states that rapid suction strikes are pre-programmed stereotyped events that proceed to completion once initiated regardless of sensory input. If this hypothesis holds true, successful strikes should be indistinguishable from unsuccessful strikes owing to a lack of feedback control in specialized suction feeding fishes. The hydrodynamics of suction feeding in white-spotted bamboo sharks (Chiloscyllium plagiosum) was studied in three behaviours: successful strikes, intraoral transports of prey and unsuccessful strikes. The area of the fluid velocity region around the head of feeding sharks was quantified using time-resolved digital particle image velocimetry (DPIV). The maximal size of the fluid velocity region is 56%larger in successful strikes than unsuccessful strikes (10.79 cm2vs 6.90 cm2), but they do not differ in duration,indicating that strikes are modulated based on some aspect of the prey or simply as a result of decreased effort on the part of the predator. The hydrodynamic profiles of successful and unsuccessful strikes differ after 21 ms, a period probably too short to provide time to react through feedback control. The predator-to-prey distance is larger in missed strikes compared with successful strikes, indicating that insufficient suction is generated to compensate for the increased distance. An accuracy index distinguishes unsuccessful strikes (–0.26) from successful strikes (0.45 to 0.61). Successful strikes occur primarily between the horizontal axis of the mouth and the dorsal boundary of the ingested parcel of water, and missed prey are closer to the boundary or beyond. Suction transports are shorter in duration than suction strikes but have similar maximal fluid velocity areas to move the prey through the oropharyngeal cavity into the oesophagus (54 ms vs 67 ms).
The kinematic determinants of anuran swimming performance: an inverse and forward dynamics approach
Authors: Richards Christopher T. 
Published: September 2008

SUMMARYThe aims of this study were to explore the hydrodynamic mechanism of Xenopus laevis swimming and to describe how hind limb kinematics shift to control swimming performance. Kinematics of the joints, feet and body were obtained from high speed video of X. laevis frogs (N=4)during swimming over a range of speeds. A blade element approach was used to estimate thrust produced by both translational and rotational components of foot velocity. Peak thrust from the feet ranged from 0.09 to 0.69 N across speeds ranging from 0.28 to 1.2 m s–1. Among 23 swimming strokes, net thrust impulse from rotational foot motion was significantly higher than net translational thrust impulse, ranging from 6.1 to 29.3 N ms,compared with a range of –7.0 to 4.1 N ms from foot translation. Additionally, X. laevis kinematics were used as a basis for a forward dynamic anuran swimming model. Input joint kinematics were modulated to independently vary the magnitudes of foot translational and rotational velocity. Simulations predicted that maximum swimming velocity (among all of the kinematics patterns tested) requires that maximal translational and maximal rotational foot velocity act in phase. However, consistent with experimental kinematics, translational and rotational motion contributed unequally to total thrust. The simulation powered purely by foot translation reached a lower peak stroke velocity than the pure rotational case (0.38 vs 0.54 m s–1). In all simulations, thrust from the foot was positive for the first half of the power stroke, but negative for the second half. Pure translational foot motion caused greater negative thrust(70% of peak positive thrust) compared with pure rotational simulation (35%peak positive thrust) suggesting that translational motion is propulsive only in the early stages of joint extension. Later in the power stroke, thrust produced by foot rotation overcomes negative thrust (due to translation). Hydrodynamic analysis from X. laevis as well as forward dynamics give insight into the differential roles of translational and rotational foot motion in the aquatic propulsion of anurans, providing a mechanistic link between joint kinematics and swimming performance.
Pitching stabilizationviacaudal fin-wave propagation in a forward-sinking parrot cichlid (Cichlasoma citrinellum×Cichlasoma synspilum)
Authors: Ting S. C. , Yang J. T. 
Published: September 2008

SUMMARYCaudal fin-wave propagation (CFP) is a commonly observed behavior in a fish but has been little investigated. Our objective is to understand the function of a CFP for a forward-sinking parrot cichlid that adopts a tilted-down swimming posture. We utilized stereoscopic digital particle-image velocimetry to measure the velocity fields in the wake of both the caudal fin and the pectoral fins and to evaluate the corresponding hydrodynamic forces. The tilted-down posture of this fish is inherently unstable because of the presence of the head-down pitching moment induced from the buoyant force of the body. The down-stroke of the pectoral fins results also in a head-down pitching moment that destabilizes the fish. Our results indicate that a CFP facilitates the pitching stabilization of a fish. In a forward-sinking parrot cichlid, a CFP produces periodic jets (CFP jets) that are oriented laterally and posterodorsally, which result in both thrust and negative lift that induce a head-up pitching moment. The CFP jets are initially trapped by the ventral part of the caudal fin, strengthened and reoriented by the dorsally propagating fin wave, and expelled near the dorsal part of the caudal fin.
Foraging bats avoid noise
Authors: Schaub Andrea , Ostwald Joachim , Siemers Björn M. 
Published: September 2008

SUMMARY
Ambient noise influences the availability and use of acoustic information in animals in many ways. While much research has focused on the effects of noise on acoustic communication, here, we present the first study concerned with anthropogenic noise and foraging behaviour. We chose the greater mouse-eared bat (Myotis myotis) as a model species because it represents the especially vulnerable group of gleaning bats that rely on listening for prey rustling sounds to find food (i.e. `passive listening'). In a choice experiment with two foraging compartments, we investigated the influence of background noise on foraging effort and foraging success. We tested the hypotheses that: (1) bats will avoid foraging areas with particularly loud background noise; and (2) the frequency–time structure of the noise will determine, in part, the degree to which it deters bats. We found a clear effect of the type of noise on the allocation of foraging effort to the compartments and on the distribution of prey capture events. When playing back silence, the bats made equal use of and were equally successful in both compartments. In the other three treatments (where a non-silent sound was played back), the bats avoided the playback compartment. The degree to which the background noise deterred bats from the compartment increased from traffic noise to vegetation movement noise to broadband computer-generated noise. Vegetation noise, set 12 dB below the traffic noise amplitude, had a larger repellent effect; presumably because of its acoustic similarity with prey sounds. Our experimental data suggest that foraging areas very close to highways and presumably also to other sources of intense, broadband noise are degraded in their suitability as foraging areas for such `passive listening'bats.
The effect of nitroglycerin ointment on great saphenous vein targeted venous access site diameter with endovenous laser treatment
Authors: Hogue R S , Schul M W , Dando C F , Erdman B E 
Published: September 2008

Objectives To assess the effect of topically applied nitroglycerin (NTG) ointment (2%) on preoperative targeted venous access site great saphenous vein (GSV) diameter in patients undergoing endovenous laser treatment (ELT). Methods In this double-blinded randomized study design, 75 patients received either (A) treadmill ambulation only, (B) topically applied NTG ointment only, or (C) topically applied NTG ointment + treadmill ambulation. Targeted venous access vein diameters were measured before therapeutic intervention and then repeated after approximately 30 min following pretreatment intervention. Presence of venospasm and the number of ultrasound-guided venous access attempts during each ELT procedure were assessed during the study. Results The mean pretreatment vein diameter was 2.6 mm (range 0.9–4.9 mm). The post-treatment percentage change in vein diameter for group A (treadmill ambulation only) was +2.7% ( P = 0.403), whereas group B (NTG only) and group C (NTG + treadmill ambulation) demonstrated significant venodilatation of +69.0% ( P < 0.0001) and +51.7% ( P < 0.0001), respectively. Statistical analysis of variances and multivariate linear regression model revealed topically applied NTG ointment and ‘C’ classification of clinical, aetiological, anatomical and pathological elements (CEAP) were each significant predictors for venodilatation percentage change ( P < 0.001 and = 0.028, respectively). Conclusion Pretreatment with topically applied NTG ointment (2%) produced a statistically significant, as well as subjective clinically significant venodilatation change in the targeted venous access site diameter of patients undergoing ELT of the GSV in this study.
Endovenous laser ablation: mechanism of action
Authors: Fan C-M , Rox-Anderson R 
Published: September 2008

ObjectivesThe objective of this study is to review the basics of laser and established tissue response patterns to thermal injury, with specific reference to endovenous laser ablation (EVLA). This study also reviews the current theories and supporting aspects for the mechanism of action of EVLA in the treatment of superficial venous reflux.MethodsThe method involves the review of published literature and original investigation of histological effects of 810 nm and 980 nm wavelength EVLA on explanted blood-filled bovine saphenous vein in an in vitro system.ResultsThe existing histological reports confirm that EVLA produces a transmural vein wall injury, typically associated with perforations and carbonization. The pattern of injury is eccentrically distributed, with maximum injury occurring along the path of laser contact. Intravenous temperature monitoring studies during EVLA have confirmed that the peak temperatures at the fibre tip exceed 1000°C, and continuous temperatures of at least 300°C are maintained in the firing zone for the majority of the procedure. Steam production during EVLA, which occurs early in the photothermolytic process when temperatures reach 100°C, accounts for only 2% of applied energy dose, and is therefore unlikely to be the primary mechanism of action of thermal injury during the procedure.ConclusionEVLA causes permanent vein closure through a high-temperature photothermolytic process at the point of contact between the vein and the laser.
“I Like Others to Not Try to Fix Me”: Agency, Independence, and Autism
Authors: Rossetti Zachary , Ashby Christine , Arndt Katrina , Chadwick Marilyn , Kasahara Maho 
Published: September 2008

AbstractThis article is based on an interpretevist, qualitative research project conducted with individuals labeled with autism who type to communicate. Researchers engaged in participant observation and conducted open-ended interviews with 9 participants who were working to develop independent typing skills. Three findings emerged from this research. First, participants shaped a notion of independence that included dependence on various supports. Second, researchers recognized the concept of agency in the interactions between participants and their communication facilitators. Third, participants exercised control of their lives through these expressions of agency.
Quantitation of Serum Free Light Chains in Combination with Protein Electrophoresis and Clinical Information for Diagnosing Multiple Myeloma in a General Hospital Population
Authors: Piehler Armin P , Gulbrandsen Nina , Kierulf Peter , Urdal Petter 
Published: September 2008

AbstractBackground: Serum free light chain (SFLC) measurements have recently come into use as an aid for diagnosing monoclonal gammopathy. We evaluated SFLC measurements in combination with serum protein electrophoresis (SPE) and clinical information for diagnosing multiple myeloma (MM) in a hospital population.Methods: We measured SFLCs in 3818 sera received for SPE over a 1-year period when patient symptoms or biochemical findings suggested myeloma-related tissue damage (n = 1067). We reviewed SPE and SFLC results from 489 patients together with their final diagnoses obtained from the hospital information technology department.Results: SFLC measurement, combined with SPE and clinical information, allowed identification of 95% of patients (38 of 40) with previously undiagnosed MM, macroglobulinemia, or primary amyloidosis. Additionally, we identified 45 patients with monoclonal gammopathy of undetermined significance (MGUS) and 4 with plasmacytoma. Of patients followed at our hospital in whom SFLCs were not measured, only 1 patient was diagnosed with MM. This patient had anemia and was mistakenly not tested for SFLCs. An abnormal κ/λ ratio was found in 26 of 29 patients with MM but also in 36 of 203 patients with renal impairment, polyclonal immunoresponse, or other nonhematological diagnoses. None of the 203 patients with nonhematological disease had a κ/λ ratio &lt;0.05 or &gt;10.Conclusions: The combined use of SPE, SFLC measurements, and clinical criteria allows MM to be efficiently diagnosed or excluded based on serum measurements only.
Quantification of Thyroglobulin, a Low-Abundance Serum Protein, by Immunoaffinity Peptide Enrichment and Tandem Mass Spectrometry
Authors: Hoofnagle Andrew N , Becker Jessica O , Wener Mark H , Heinecke Jay W 
Published: September 2008

AbstractBackground: Quantification of serum tumor markers plays an important role in determining whether patients treated for cancer require further therapy. Whereas large-scale proteomic efforts aim to identify novel tumor markers to facilitate early detection, optimization of methods for quantifying known tumor markers offers another approach to improving management of malignancies. For example, immunoassays used in clinical practice to measure established tumor markers suffer from potential interference from endogenous immunoglobulins and imperfect concordance across platforms—problems that also plague many other immunoassays. To address these important limitations, this study used peptide immunoaffinity enrichment in concert with liquid chromatography–tandem mass spectrometry (LC-MS/MS) to quantify thyroglobulin, a well-characterized tumor marker.Methods: We identified 3 peptides in tryptic digests of thyroglobulin that were detected at low concentrations by tandem mass spectrometry, raised polyclonal antibodies to those peptides, and used the antibodies to extract the 3 corresponding peptides from tryptic digests of human serum. We quantified each endogenous peptide using LC-MS/MS and multiple reaction monitoring with external calibrators.Results: The detection limit for endogenous thyroglobulin in serum was 2.6 μg/L (4 pmol/L). Direct comparison with immunoassay revealed good correlation (r2 = 0.81).Conclusions: Immunoaffinity peptide enrichment–tandem mass spectrometry can detect tryptic peptides of thyroglobulin at picomolar concentrations while also digesting the endogenous immunoglobulins that can potentially interfere with traditional immunoassays. Our observations suggest a general analytical strategy for using immunoaffinity isolation together with tandem mass spectrometry to quantify tumor antigens and other low-abundance proteins in human serum.
Prospective Isolation of Skeletal Muscle Stem Cells with a Pax7 Reporter
Authors: Bosnakovski Darko , Xu Zhaohui , Li Wei , Thet Suwannee , Cleaver Ondine , Perlingeiro Rita C.R. , Kyba Michael 
Published: September 2008

Abstract
Muscle regeneration occurs through activation of quiescent satellite cells whose progeny proliferate, differentiate, and fuse to make new myofibers. We used a transgenic Pax7-ZsGreen reporter mouse to prospectively isolate stem cells of skeletal muscle by flow cytometry. We show that Pax7-expressing cells (satellite cells) in the limb, head, and diaphragm muscles are homogeneous in size and granularity and uniformly labeled by certain cell surface markers, including CD34 and CD29. The frequency of the satellite cells varies between muscle types and with age. Clonal analysis demonstrated that all colonies arising from single cells within the Pax7-sorted fraction have myogenic potential. In response to injury, Pax7+ cells reduce CD34, CD29, and CXCR4 expression, increase in size, and acquire Sca-1. When directly isolated and cultured in vitro, Pax7+ cells display the hallmarks of activation and proliferate, initially as suspension aggregates and later distributed between suspension and adherence. During in vitro expansion, Pax7 (ZsGreen) and CD34 expression decline, whereas expression of PSA-NCAM is acquired. The nonmyogenic, Pax7neg cells expand as Sca1+ PDGRα+ PSA-NCAMneg cells. Satellite cells expanded exclusively in suspension can engraft and produce dystrophin+ fibers in mdx−/− mice. These results establish a novel animal model for the study of muscle stem cell physiology and a culture system for expansion of engraftable muscle progenitors.
Disclosure of potential conflicts of interest is found at the end of this article.
Secreted Proteoglycans Directly Mediate Human Embryonic Stem Cell-Basic Fibroblast Growth Factor 2 Interactions Critical for Proliferation
Authors: Levenstein Mark E. , Berggren W. Travis , Lee Ji Eun , Conard Kevin R. , Llanas Rachel A. , Wagner Ryan J. , Smith Lloyd M. , Thomson James A. 
Published: September 2008

Abstract
Human embryonic stem (ES) cells can be maintained in an undifferentiated state if the culture medium is first conditioned on a layer of mouse embryonic fibroblast (MEF) feeder cells. Here we show that human ES cell proliferation is coordinated by MEF-secreted heparan sulfate proteoglycans (HSPG) in conditioned medium (CM). These HSPG and other heparinoids can stabilize basic fibroblast growth factor (FGF2) in unconditioned medium at levels comparable to those observed in CM. They also directly mediate binding of FGF2 to the human ES cell surface, and their removal from CM impairs proliferation. Finally, we have developed a purification scheme for MEF-secreted HSPG in CM. Using column chromatography, immunoblotting, and mass spectrometry-based proteomic analysis, we have identified multiple HSPG species in CM. The results demonstrate that HSPG are key signaling cofactors in CM-based human ES cell culture.
Disclosure of potential conflicts of interest is found at the end of this article.
Toxicity of select organic acids to the slightly thermophilic acidophile Acidithiobacillus caldus
Authors: Aston John E. , Apel William A. , Lee Brady D. , Peyton Brent M. 
Published: September 2008

Abstract
Acidithiobacillus caldus is a thermophilic acidophile found in commercial biomining, acid mine drainage systems, and natural environments. Previous work has characterized A. caldus as a chemolithotrophic autotroph capable of utilizing reduced sulfur compounds under aerobic conditions. Organic acids are especially toxic to chemolithotrophs in low-pH environments, where they diffuse more readily into the cell and deprotonate within the cytoplasm. In the present study, the toxic effects of oxaloacetate, pyruvate, 2-ketoglutarate, acetate, malate, succinate, and fumarate on A. caldus strain BC13 were examined under batch conditions. All tested organic acids exhibited some inhibitory effect. Oxaloacetate was observed to inhibit growth completely at a concentration of 250 μM, whereas other organic acids were completely inhibitory at concentrations of between 1,000 and 5,000 μM. In these experiments, the measured concentrations of organic acids decreased with time, indicating uptake or assimilation by the cells. Phospholipid fatty acid analyses indicated an effect of organic acids on the cellular envelope. Notable differences included an increase in cyclic fatty acids in the presence of organic acids, indicating possible instability of the cellular envelope. This was supported by field emission scanning-electron micrographs showing blebbing and sluffing in cells grown in the presence of organic acids.
Plantar Stresses on the Neuropathic Foot During Barefoot Walking
Authors: Mueller Michael J , Zou Dequan , Bohnert Kathryn L , Tuttle Lori J , Sinacore David R 
Published: September 2008

Background and PurposePatients with diabetes mellitus and peripheral neuropathy are at high risk for plantar skin breakdown due to unnoticed plantar stresses during walking. The purpose of this study was to determine differences in stress variables (peak plantar pressure, peak pressure gradient, peak maximal subsurface shear stress, and depth of peak maximal subsurface shear stress) between the forefoot (where most ulcers occur) and the rear foot in subjects with and without diabetes mellitus, peripheral neuropathy, and a plantar ulcer measured during barefoot walking.SubjectsTwenty-four subjects participated: 12 with diabetes mellitus, peripheral neuropathy, and a plantar ulcer (DM+PN group) and 12 with no history of diabetes mellitus or peripheral neuropathy (control group). The subjects (11 men, 13 women) had a mean age (±SD) of 54±8 years.MethodsPlantar pressures were measured during barefoot walking using a pressure platform. Stress variables were estimated at the forefoot and the rear foot for all subjects.ResultsAll stress variables were higher (127%–871%) in the forefoot than in the rear foot, and the peak pressure gradient showed the greatest difference (538%–871%). All stress variables were higher in the forefoot in the DM+PN group compared with the control group (34%–85%), and the peak pressure gradient showed the greatest difference (85%). The depth (X̅±SD) of peak maximum subsurface shear stress in the forefoot in the DM+PN group was half that in the control group (3.8±2.0 versus 8.0±4.3 mm, respectively).Discussion and ConclusionsThese results indicate that stresses are relatively higher and located closer to the skin surface in locations where skin breakdown is most likely to occur. These stress variables may have additional value in predicting skin injury over the traditionally measured peak plantar pressure, but prospective studies using these variables to predict ulcer risk are needed to test this hypothesis.