bluuebunny/crossref_metadata_2025_split huggingface dataset:
Decreased echolocation performance following high-frequency hearing loss in the false killer whale (Pseudorca crassidens)
Authors: Kloepper L. N. , Nachtigall P. E. , Gisiner R. , Breese M. 
Published: October 2010

SUMMARYToothed whales and dolphins possess a hypertrophied auditory system that allows for the production and hearing of ultrasonic signals. Although the fossil record provides information on the evolution of the auditory structures found in extant odontocetes, it cannot provide information on the evolutionary pressures leading to the hypertrophied auditory system. Investigating the effect of hearing loss may provide evidence for the reason for the development of high-frequency hearing in echolocating animals by demonstrating how high-frequency hearing assists in the functioning echolocation system. The discrimination abilities of a false killer whale (Pseudorca crassidens) were measured prior to and after documented high-frequency hearing loss. In 1992, the subject had good hearing and could hear at frequencies up to 100 kHz. In 2008, the subject had lost hearing at frequencies above 40 kHz. First in 1992, and then again in 2008, the subject performed an identical echolocation task, discriminating between machined hollow aluminum cylinder targets of differing wall thickness. Performances were recorded for individual target differences and compared between both experimental years. Performances on individual targets dropped between 1992 and 2008, with a maximum performance reduction of 36.1%. These data indicate that, with a loss in high-frequency hearing, there was a concomitant reduction in echolocation discrimination ability, and suggest that the development of a hypertrophied auditory system capable of hearing at ultrasonic frequencies evolved in response to pressures for fine-scale echolocation discrimination.
Arboreal locomotion in rats – the challenge of maintaining stability
Authors: Schmidt André , Fischer Martin S. 
Published: October 2010

SUMMARYArboreal locomotion has mainly been looked at to date in the context of investigations into the specialization of primates and other ‘arboreally adapted’ animals. The feat of moving on branches as small or smaller than the body's diameter was tested in rats (Rattus norvegicus) as they moved on horizontal poles of different diameters. The data were compared with data pertaining to terrestrial locomotion. We investigated three-dimensional kinematics and dynamics using biplanar cineradiography with simultaneous substrate reaction force (SRF) measurements. As predicted, rats flexed fore- and hindlimbs and reduced vertical forces during pole locomotion. In addition, the orientation of the mediolateral substrate reaction force resultant (SRR) and impulses switched from lateral to medial. In order to maintain stability during arboreal locomotion, lateral spine movements increased. We propose that the combination of lateral sequence gaits, similar travel speed of the animals and similar contact times, higher or similar peak vertical forces as well as similar mediolateral impulses in forelimbs and hindlimbs are typical of clawed mammals moving on thin supports. Clawed mammals and primates share the reduction of vertical oscillations and side-to-side fluctuations, a crouched posture as well as the increase in lateral spine movements. We conclude that these features are behavioral adaptations caused by the biomechanical constraints of small branch locomotion, regardless of the way they make contact with the substrate.
The catecholamine release-inhibitory peptide catestatin (chromogranin A344-364) modulates myocardial function in fish
Authors: Imbrogno Sandra , Garofalo Filippo , Cerra Maria Carmela , Mahata Sushil K. , Tota Bruno 
Published: October 2010

SUMMARY
Catestatin (CST), the 21-amino acid, cationic and hydrophobic peptide proteolytically derived from the ubiquitous chromogranin A (CgA), is an endogenous inhibitor of catecholamine release, a potent vasodilator in vivo and an anti-hypertensive agent in mammals, including humans. Recently, we discovered that CST also functions as an important negative modulator of heart performance in frog and rat. To gain an evolutionary perspective on CST cardiotropism in fish, we analysed the influence of bovine CST (CgA344-364) on the eel heart, as well as the eventual species-specific mechanisms of its myocardial action. Experiments were carried out on fresh-water eels (Anguilla anguilla L.) using an electrically paced isolated working heart preparation. Stroke volume and stroke work were used as measures of ventricular performance. Under basal conditions, CST (from 11 nmol l–1 to 165 nmol l–1) caused a concentration-dependent negative inotropism, which was abolished by inhibitors of either β1/β2 (propranolol) or β3 (SR59230) adrenergic receptors, or by Gi/o protein (PTx) or nitric oxide synthase (L-NMMA), or guanylate cyclase (ODQ) blockers. This suggests a β-adrenergic receptor-Gi/o protein-NO-cGMP-dependent mechanism. By contrast, the CST-induced cardio-suppression was not influenced by atropine, unspecific muscarinic antagonist, thus excluding cholinergic receptor involvement. CST also counteracted the adrenergic (isoproterenol)-mediated positive inotropism. Under increased preload (i.e. Frank–Starling response) conditions, CST induced a significant increase of the Frank–Starling response, which was blocked by L-NMMA and thapsigargin, but independent from guanylate cyclase. In conclusion, this is the first report in fish that CST modulates myocardial performance under basal, as well as under increased preload, conditions and counteracts the adrenergic-mediated positive inotropism, which strikingly supports the evolutionary significance and establishes the cardioactive role of this peptide.
Response properties of crayfish antennules to hydrodynamic stimuli: functional differences in the lateral and medial flagella
Authors: Monteclaro Harold M. , Anraku Kazuhiko , Matsuoka Tatsuro 
Published: October 2010

SUMMARYAntennules have been reported to influence localization of distant food odors, sex discrimination, and agonistic and social behaviors of decapod crustaceans. Although olfaction by the antennules is largely recognized, information on the sensitivity of antennules to hydrodynamic stimuli has been scant. In red swamp crayfish Procambarus clarkii antennules, mechanosensory setae outnumber the chemosensory setae. We studied the mechanosensitivity of crayfish antennules by recording neural activities from isolated antennules in response to sinusoidal dipole stimuli. Both the lateral and the medial flagellum of the antennules responded to hydrodynamic stimuli, although the medial flagellum showed more sensitivity at frequencies higher than 60 Hz. The most dominant setae present on the stimulated site were the simple setal type. Although both lateral and medial flagella are capable of detecting chemical and hydrodynamic cues, results from neural responses, morphological observations and antennular behavior observations indicate that the lateral flagellum of P. clarkii functions as an olfactory organ whereas the medial flagellum complements as a hydrodynamic receptor. It appears that in crayfish antennular sensory processing, crayfish simultaneously use chemical and hydrodynamic information. We have compared our data with the threshold of fish lateral line to the same stimuli and we discuss probable similarities in response properties.
Cardiac responses to anoxia in the Pacific hagfish,Eptatretus stoutii
Authors: Cox Georgina K. , Sandblom Erik , Farrell Anthony P. 
Published: October 2010

SUMMARYIn the absence of any previous study of the cardiac status of hagfishes during prolonged anoxia and because of their propensity for oxygen-depleted environments, the present study tested the hypothesis that the Pacific hagfish Eptatretus stoutii maintains cardiac performance during prolonged anoxia. Heart rate was halved from the routine value of 10.4±1.3 beats min–1 by the sixth hour of an anoxic period and then remained stable for a further 30 h. Cardiac stroke volume increased from routine (1.3±0.1 ml kg–1) to partially compensate the anoxic bradycardia, such that cardiac output decreased by only 33% from the routine value of 12.3±0.9 ml min–1 kg–1. Cardiac power output decreased by only 25% from the routine value of 0.26±0.02 mW g–1. During recovery from prolonged anoxia, cardiac output and heart rate increased to peak values within 1.5 h. Thus, the Pacific hagfish should be acknowledged as hypoxic tolerant in terms of its ability to maintain around 70% of their normoxic cardiac performance during prolonged anoxia. This is only the second fish species to be so classified.
Zebrafish take their cue from temperature but not photoperiod for the seasonal plasticity of thermal performance
Authors: Condon Catriona H. , Chenoweth Stephen F. , Wilson Robbie S. 
Published: October 2010

SUMMARYOrganisms adjust to seasonal variability in the environment by responding to cues that indicate environmental change. As most studies of seasonal phenotypic plasticity test only the effect of a single environmental cue, how animals may integrate information from multiple cues to fine-tune plastic responses remains largely unknown. We examined the interaction between correlated (seasonally matching) and conflicting (seasonally opposite) temperature and photoperiod cues on the acclimation of performance traits in male zebrafish, Danio rerio. We acclimated fish for 8 weeks and then tested the change in thermal dependence of maximum burst swimming and feeding rate between 8 and 38°C. We predicted that correlated environmental cues should induce a greater acclimation response than uncorrelated cues. However, we found that only temperature was important for the seasonal acclimation of performance traits in zebrafish. Thermal acclimation shifted the thermal performance curve of both traits. For maximum burst swimming, performance increased for each group near the acclimation temperature and reduced in environments that were far from their acclimation temperature. The feeding rate of cold-acclimated zebrafish was reduced across the test temperature range compared with that of warm-acclimated fish. Our study is the first that has found no effect of the covariation between temperature and photoperiod acclimation cues on locomotor performance in fishes. Our results support the intuitive idea that photoperiod may be a less important seasonal cue for animals living at lower latitudes.
The impact of glide phases on the trackability of hydrodynamic trails in harbour seals (Phoca vitulina)
Authors: Wieskotten S. , Dehnhardt G. , Mauck B. , Miersch L. , Hanke W. 
Published: October 2010

SUMMARYThe mystacial vibrissae of harbour seals (Phoca vitulina) constitute a highly sensitive hydrodynamic receptor system enabling the seals to detect and follow hydrodynamic trails. In the wild, hydrodynamic trails, as generated by swimming fish, consist of cyclic burst-and-glide phases, associated with various differences in the physical parameters of the trail. Here, we investigated the impact of glide phases on the trackability of differently aged hydrodynamic trails in a harbour seal. As fish are not easily trained to swim certain paths with predetermined burst-and-glide phases, the respective hydrodynamic trails were generated using a remote-controlled miniature submarine. Gliding phases in hydrodynamic trails had a negative impact on the trackability when trails were 15 s old. The seal lost the generated trails more often within the transition zones, when the submarine switched from a burst to a glide moving pattern. Hydrodynamic parameter analysis (particle image velocimetry) revealed that the smaller dimensions and faster decay of hydrodynamic trails generated by the gliding submarine are responsible for the impaired success of the seal tracking the gliding phase. Furthermore, the change of gross water flow generated by the submarine from a rearwards-directed stream in the burst phase to a water flow passively dragged behind the submarine during gliding might influence the ability of the seal to follow the trail as this might cause a weaker deflection of the vibrissae. The possible ecological implications of intermittent swimming behaviour in fish for piscivorous predators are discussed.
Putative pacemakers of crayfish show clock proteins interlocked with circadian oscillations
Authors: Escamilla-Chimal Elsa G. , Velázquez-Amado Rosa María , Fiordelisio Tatiana , Fanjul-Moles María Luisa 
Published: October 2010

SUMMARYAlthough the molecular mechanisms that control circadian rhythms in many animals, particularly in the fly, are well known, molecular and biochemical studies addressing the location and function of the proteins and genes contributing to the cycling of the clock in crayfish Procambarus clarkii are scarce. In this study, we investigated whether three proteins that interact in the feedback loop of the molecular clock described for Drosophila are expressed in the putative circadian pacemakers of crayfish retina, eyestalk and brain and whether their expression cycles in a manner consistent with elements of the circadian clock. Here we identified PER, TIM and CLK immunoreactivity in the cytoplasm and nucleus of cells located in the retina as well as in clusters of cells and neuropils of the optic ganglia, lateral protocerebrum and brain. Brain clusters 6, 10, 9 and 11, in particular, showed Per, Tim and Clk-like immunoreactivity at the perikarya and nucleus, and these antigens colocalized at Zeitgeber time (ZT) 0 and/or ZT 12. A biochemical assay demonstrated circadian functionality of Per, Tim and Clk proteins. Both in the eyestalk and in the brain, these proteins demonstrated apparent daily and circadian rhythms. The presence and colocalization of these clock proteins in the cytoplasm and/or nucleus of several cells of retina, optic lobe and brain, depending on time, as well as their circadian oscillations, suggest interactions between positive and negative transcription factors and clock proteins similar to those forming the feedback loop of the canonical model proposed for different animals.
Nitric oxide metabolites in goldfish under normoxic and hypoxic conditions
Authors: Hansen Marie N. , Jensen Frank B. 
Published: October 2010

SUMMARYNitric oxide (NO), produced by nitric oxide synthases (NOS enzymes), regulates multiple physiological functions in animals. NO exerts its effects by binding to iron (Fe) of heme groups (exemplified by the activation of soluble guanylyl cyclase) and by S-nitrosylation of proteins – and it is metabolized to nitrite and nitrate. Nitrite is used as a marker for NOS activity but it is also a NO donor that can be activated by various cellular proteins under hypoxic conditions. Here, we report the first systematic study of NO metabolites (nitrite, nitrate, S-nitroso, N-nitroso and Fe-nitrosyl compounds) in multiple tissues of a non-mammalian vertebrate (goldfish) under normoxic and hypoxic conditions. NO metabolites were measured in blood (plasma and red cells) and heart, brain, gill, liver, kidney and skeletal muscle, using highly sensitive reductive chemiluminescence. The severity of the chosen hypoxia levels was assessed from metabolic and respiratory variables. In normoxic goldfish, the concentrations of NO metabolites in plasma and tissues were comparable with values reported in mammals, indicative of similar NOS activity. Exposure to hypoxia [at PO2 (partial pressure of O2) values close to and below the critical PO2] for two days caused large decreases in plasma nitrite and nitrate, which suggests reduced NOS activity and increased nitrite/nitrate utilization or loss. Tissue NO metabolites were largely maintained at their tissue-specific values under hypoxia, pointing at nitrite transfer from extracellular to intracellular compartments and cellular NO generation from nitrite. The data highlights the preference of goldfish to defend intracellular NO homeostasis during hypoxia.
Elevated phenylalanine on newborn screening: follow-up testing may reveal undiagnosed galactosaemia
Authors: Shakespeare Lynette , Downing Melanie , Allen Joyce , Casbolt Ann-Marie , Ellin Sheila , Maloney Martin , Race Gillian , Bonham Jim 
Published: October 2010

Introduction Newborn screening for phenylketonuria (PKU) can reveal other conditions which lead to an increased blood spot phenylalanine (Phe) concentration. We have investigated the proportion of blood spot samples that gave a positive screen due to clinically significant conditions other than PKU, compared the positive predictive value (PPV) of our referral Phe cut-off with that recommended by the UK Newborn Screening Programme Centre (UKNSPC) (>210 and >240 μmol/L, respectively) and evaluated the effectiveness of reflex testing for galactosaemia using a lower blood spot Phe cut-off concentration of 130 μmol/L. Methods All blood spot samples that screened positive, for an increased Phe concentration, between April 2001 and March 2008, were identified from the records of the Sheffield Newborn Screening Laboratory and the diagnoses noted. In addition, all cases of galactosaemia detected in or notified to our screening laboratory within this time were also examined and the screened Phe concentrations compared. Results Out of 438,674 babies who were screened, 67 had Phe concentration >210 μmol/L (15 per 100,000). Of these, 40 had PKU or persistent hyperphenylalaninaemia with a Phe concentration identified by screening between 270 and 2350 μmol/L. A further 11 were diagnosed with another clinically significant disorder: galactosaemia ( n = 8), biopterin defects ( n = 2), tyrosinaemia Type 1 ( n = 1). In addition, 16 had transient elevations in Phe. In total, nine cases of galactosaemia were identified, of whom, three had Phe concentrations <240 μmol/L with one asymptomatic individual having a concentration <210 μmol/L. Conclusions Adoption of the UKNSPC recommended cut-off (>240 μmol/L) will not affect the detection rate of classical PKU, but will improve the PPV from 76% to 80%. The use of a lower cut-off (130 μmol/L) for reflex galactosaemia testing enables the timely identification of asymptomatic cases that benefit particularly from early treatment, without prompting any unnecessary clinical referrals or delaying any referrals. This intervention may reduce mortality in this vulnerable group.
Agreement Between Fasting and Postprandial LDL Cholesterol Measured with 3 Methods in Patients with Type 2 Diabetes Mellitus
Authors: Lund Søren S , Petersen Martin , Frandsen Merete , Smidt Ulla M , Parving Hans-Henrik , Vaag Allan A , Jensen Tonny 
Published: October 2010

BACKGROUNDLDL cholesterol (LDL-C) is a modifiable cardiovascular disease risk factor. We used 3 LDL-C methods to study the agreement between fasting and postprandial LDL-C in type 2 diabetes (T2DM) patients.METHODSWe served 74 T2DM patients a standardized meal and sampled blood at fasting and 1.5, 3.0, 4.5, and 6.0 h postprandially. We measured LDL-C by use of modified β quantification (MBQ), the Friedewald equation (FE), and a direct homogeneous assay (DA). We evaluated agreement using 95% limits of agreement (LOA) within ±0.20 mmol/L (±7.7 mg/dL).RESULTSLDL-C concentrations at all postprandial times disagreed with those at fasting for all methods. In 66 patients who had complete measurements with all LDL-C methods, maximum mean differences (95% LOA) in postprandial vs fasting LDL-C were −0.16 mmol/L (−0.51; 0.19) [−6.2 mg/dL (−19.7; 7.3)] with MBQ at 3 h; −0.36 mmol/L (−0.89; 0.17) [−13.9 mg/dL (−34; 6.6)] with FE at 4.5 h; and −0.24 mmol/L (−0.62; 0.05) [−9.3 mg/dL (−24; 1.9)] with DA at 6.0 h. In postprandial samples, FE misclassified 38% of patients (two-thirds of statin users) into lower Adult Treatment Panel III (ATP III) risk categories. Greater disagreement between fasting and postprandial LDL-C was observed in individuals with postprandial triglyceride concentrations &gt;2.08 mmol/L (&gt;184 mg/dL) and in women (interactions: P ≤ 0.038).CONCLUSIONSDifferences up to 0.89 mmol/L (34 mg/dL) between fasting and postprandial LDL-C concentrations, with postprandial LDL-C concentrations usually being lower, were found in T2DM by 3 different LDL-C methods. Such differences are potentially relevant clinically and suggest that, irrespective of measurement method, postprandial LDL-C concentrations should not be used to assess cardiovascular disease risk.
Comparative Effectiveness of Calcium-Containing Phosphate Binders in Incident U.S. Dialysis Patients
Authors: Winkelmayer Wolfgang C. , Liu Jun , Kestenbaum Bryan 
Published: October 2010

Summary

Background and objectives
Few studies have assessed the association between phosphate binder use and hard outcomes in dialysis patients. Furthermore, the comparative effectiveness of calcium carbonate and acetate is untested. We studied the association between use versus nonuse of calcium-containing phosphate binders (CCPBs) and mortality from any cause. We also tested whether mortality differed among users of individual CCPBs.

Design, setting, participants, & measurements
A nationally representative prospective cohort of incident U.S. dialysis patients (1996 to 1997), assembled before the availability of sevelamer and lanthanum, was used. Use of each CCPB was ascertained from chart abstraction records. A large number of sociodemographic, clinical, and laboratory characteristics were available for confounding control in multivariate and propensity score-matched Cox regression models.

Results
Among 3603 incident dialysis patients, 77.5% used a CCPB, whereas 22.5% did not. Baseline use of CCPB was associated with an adjusted 19% lower mortality rate among CCPB users compared with nonusers. With successful matching of 800 exposed and nonexposed individuals on their exposure propensity score, however, CCPB users and nonusers had similar mortality. No mortality differences were observed between calcium acetate and calcium carbonate users in crude, adjusted, or propensity-matched analyses.

Conclusions
No association was found between CCPB use and 1-year mortality in incident dialysis patients; choice of calcium carbonate versus acetate was also not associated with this outcome. Randomized trials are necessary to understand whether the prevailing practice of phosphate-binding therapy actually reduces adverse clinical outcomes.
Comparison of passive transfer of immunity in neonatal dairy calves fed colostrum or bovine serum-based colostrum replacement and colostrum supplement products
Authors: Poulsen Keith P. , Foley Andrea L. , Collins Michael T. , McGuirk Sheila M. 
Published: October 2010

Abstract
Objective—To compare serum total protein (sTP) and serum IgG (sIgG) concentrations In neonatal calves administered colostrum or a bovine serum-based colostrum replacement (CR) product followed by a bovine serum-based colostrum supplement (CS) product.
Design—Randomized controlled clinical trial.
Animals—18 Jersey and 269 Holstein neonatal heifer calves.
Procedures—141 calves were given 4 L of colostrum in 1 or 2 feedings (first or only feeding was provided ≤ 2 hours after birth; when applicable, a second feeding was provided between 2 and 12 hours after birth). Other calves (n = 146) were fed 2 L of a CR product ≤ 2 hours after birth and then 2 L of a CS product between 2 and 12 hours after birth. Concentrations of sTP and sIgG were measured 1 to 7 days after birth. Data from cohorts on individual farms and for all farms were analyzed.
Results—Mean sTP and sIgG concentrations differed significantly between feeding groups. In calves fed colostrum and calves fed CR and CS products, mean ± SD sTP concentration was 5.58 ± 0.67 g/dL and 5.26 ± 0.54 g/dL, respectively, and mean sIgG concentration was 1,868 ± 854 mg/dL and 1,320 ± 620 mg/dL, respectively. The percentage of calves that had failure of passive transfer of immunity (ie, sIgG concentrations < 1,000 mg/dL) was not significantly different between groups.
Conclusions and Clinical Relevance—Results suggested that sequential feeding of bovine serum-based CR and CS products to neonatal calves is an alternative to feeding colostrum for achieving passive transfer of immunity.