bluuebunny/crossref_metadata_2025_split huggingface dataset:
Respiration by buried echidnas Tachyglossus aculeatus
Authors: Waugh Courtney A. , Grigg Gordon C. , Booth David T. , Beard Lyn A. 
Published: February 2006

SUMMARY
Short-beaked echidnas have an impressive ability to submerge completely into soil or sand and remain there, cryptic, for long periods. This poses questions about how they manage their respiration, cut off from a free flow of gases. We measured the gradient in oxygen partial pressure(PO2) away from the snouts of buried echidnas and oxygen consumption(V̇O2) in five individuals under similar conditions, in two substrates with different air-filled porosities (fa). A theoretical diffusion model indicated that diffusion alone was insufficient to account for the flux of oxygen required to meet measured rates of V̇O2. However, it was noticed that echidnas often showed periodic movements of the anterior part of the body, as if such movements were a deliberate effort to flush the tidal air space surrounding their nostrils. These `flushing movements' were subsequently found to temporarily increase the levels of interstitial oxygen in the soil around the head region. Flushing movements were more frequent while V̇O2 was higher during the burrowing process, and also in substrate with lower fa. We conclude that oxygen supply to buried echidnas is maintained by diffusion through the soil augmented by periodic flushing movements, which ventilate the tidal airspace that surrounds the nostrils.
The effects of depth, temperature and food ingestion on the foraging energetics of a diving endotherm, the double-crested cormorant(Phalacrocorax auritus)
Authors: Enstipp Manfred R. , Grémillet David , Jones David R. 
Published: February 2006

SUMMARYAvian divers are confronted with a number of physiological challenges when foraging in cold water, especially at depth. Besides the obvious constraint imposed by the necessity to return to the surface for gas exchange, cold water temperatures and a reduction in body insulation due to the increase in pressure with dive depth will elevate the energetic costs of foraging in these endotherm divers. The complex effect that depth has on the diving energetics of aquatic birds has largely been ignored. To date, no study has assessed the impact of depth on diving energetics over a significant depth range, naturally encountered by the diver. We used open-circuit respirometry to study the energetic requirements of a foot-propelled pursuit diver, the double-crested cormorant (Phalacrocorax auritus albociliatus), when diving in a shallow (1 m) and deep (10 m) dive tank and when resting in air and water. We also investigated the modifying effects of air or water temperature and feeding status on the costs associated with diving and resting. Of all factors investigated, dive depth exercised the strongest influence on diving metabolic rate. Diving to 10 m depth increased metabolic rate on average by 22% when compared with shallow diving. Declining temperatures in air and water significantly elevated metabolic rate of cormorants resting in air and water as well as during diving. Feeding before resting in water or diving increased metabolic rate by 5–8% for at least 2 h. Cormorants maintained an elevated stomach temperature (&gt;42°C) when resting in water and during diving, even at cold temperatures. The elevated dive costs during deep diving,when compared with shallow diving, are most likely a consequence of the increased thermoregulatory costs associated with a greater heat loss to the water at depth. Nevertheless, our study shows that dive costs in double-crested cormorants are similar to those of other foot-propelled avian divers.
Giant liposomes as delivery system for ecophysiological studies in copepods
Authors: Buttino Isabella , De Rosa Giuseppe , Carotenuto Ylenia , Ianora Adrianna , Fontana Angelo , Quaglia Fabiana , La Rotonda Maria Immacolata , Miralto Antonio 
Published: February 2006

SUMMARYGiant liposomes are proposed as a potential delivery system in marine copepods, the dominant constituent of the zooplankton. Liposomes were prepared in the same size range as the food ingested by copepods (mean diameter of about 7 μm). The encapsulation of a hydrophilic and high molecular mass fluorescent compound, fluorescein isothiocyanate-dextran (FitcDx), within the liposomes provided a means of verifying copepod ingestion when viewed with the confocal laser-scanning microscope. Females of the calanoid copepod Temora stylifera were fed with FitcDx-encapsulated liposomes alone or mixed with the dinoflagellate alga Prorocentrum minimum. Control copepods were incubated with the P. minimum diet alone. Egg production rates,percentage egg-hatching success and number of faecal pellets produced were evaluated after 24 h and 48 h of feeding. Epifluorescence of copepod gut and faecal pellets indicated that the liposomes were actively ingested by T. stylifera in both experimental food conditions, with or without the dinoflagellate diet. Ingestion rates calculated using 3H-labelled liposomes indicated that females ingested more liposomes when P. minimum was added to the solution (16% vs 7.6% of uptake). When liposomes were supplied together with the algal diet, egg production rate,egg-hatching success and faecal pellet production were as high as those observed for the control diet. By contrary, egg production and hatching success were very low with a diet of liposomes alone and faecal pellet production was similar to that recorded in starved females. This results suggest that liposomes alone did not add any nutritive value to the diet,making them a good candidate as inert carriers to study the nutrient requirements or biological activity of different compounds. In particular,such liposomes are proposed as carriers for diatom-derived polyunsaturated aldehydes, which are known to impair copepod embryo viability. Other potential applications of liposomes as a delivery system of drugs and nutrients in copepod mass cultivation, or as carriers of pollutants to study copepod physiology in ecotoxicological experiments, are also discussed.
Taste discrimination in conditioned taste aversion of the pond snailLymnaea stagnalis
Authors: Sugai Rio , Shiga Hatsuki , Azami Sachiyo , Watanabe Takayuki , Sadamoto Hisayo , Fujito Yutaka , Lukowiak Ken , Ito Etsuro 
Published: February 2006

SUMMARYConditioned taste aversion (CTA) in the pond snail Lymnaea stagnalis has been widely used as a model for gaining an understanding of the molecular and behavioral mechanisms underlying learning and memory. At the behavioral level, however, it is still unclear how taste discrimination and CTA interact. We thus examined how CTA to one taste affected the feeding response induced by another appetitive food stimulus. We first demonstrated that snails have the capacity to recognize sucrose and carrot juice as distinct appetitive stimuli. We then found that snails can become conditioned(i.e. CTA) to avoid one of the stimuli and not the other. These results show that snails can distinguish between appetitive stimuli during CTA, suggesting that taste discrimination is processed upstream of the site where memory consolidation in the snail brain occurs. Moreover, we examined second-order conditioning with two appetitive stimuli and one aversive stimulus. Snails acquired second-order conditioning and were still able to distinguish between the different stimuli. Finally, we repeatedly presented the conditional stimulus alone to the conditioned snails, but this procedure did not extinguish the long-term memory of CTA in the snails. Taken together, our data suggest that CTA causes specific, irreversible and rigid changes from appetitive stimuli to aversive ones in the conditioning procedure.
Fuel use during glycogenesis in rainbow trout (Oncorhynchus mykissWalbaum) white muscle studiedin vitro
Authors: Kam Jennifer C. , Milligan C. Louise 
Published: February 2006

SUMMARYThe purpose of this study was to examine fuel used during muscle glycogenesis in rainbow trout Oncorhynchus mykiss using an in vitro muscle slice preparation to test the hypothesis that intracellular lactate is the major glycogenic substrate and the muscle relies upon extracellular substrates for oxidation. Fish were exhaustively exercised to reduce muscle glycogen content, muscle slices were taken from exhausted fish and incubated for 1 h in medium containing various substrates at physiological concentrations. 14C-labeled lactate, glycerol or palmitate was added and 14C incorporation into muscle glycogen and/or CO2 was measured. Lactate clearance in the absence of net glycogenesis suggests that when suitable oxidizable extracellular substrates were lacking, intracellular lactate was oxidized. Only muscle incubated in lactate, glycerol or palmitate synthesized glycogen, with the greatest synthesis in muscle incubated in lactate plus glycerol. The major fate of these extracellular substrates was oxidative, with lactate oxidized at rates 10 times that of palmitate and 100 times that of glycerol. Neither extracellular lactate nor glycerol contributed significantly to glycogenesis,with lactate carbon contributing less than 0.1% of the total glycogen synthesized, and glycerol less than 0.01%. There was 100 times more extracellular lactate-carbon incorporated into CO2 than into glycogen. In the presence of extracellular lactate, palmitate or glycerol,intracellular lactate was spared an oxidative fate, allowing it to serve as the primary substrate for in situ glycogenesis, with oxidation of extracellular substrates driving ATP synthesis. The primary fate of extracellular lactate is clearly oxidative, while that of intracellular,glycolytically derived lactate is glycogenic, which suggests intracellular compartmentation of lactate metabolism.
Distribution, activity and evidence for the release of an anti-diuretic peptide in the kissing bug Rhodnius prolixus
Authors: Paluzzi Jean-Paul , Orchard Ian 
Published: February 2006

SUMMARY
In the haematophagous insect Rhodnius prolixus, diuresis is accomplished through the combined actions of peptidergic diuretic hormones and 5-HT released from neurohaemal sites on the abdominal nerves. Preliminary work on anti-diuresis in this blood-feeder, previously believed to occur through a decrease in the levels of the diuretic factors, indicates that an anti-diuretic hormone, with properties similar to CAP2b (pELYAFPRVamide;recently renamed Mas-CAPA-1), might also be present in R. prolixus. Here, we present evidence from immunohistochemical analysis that suggests a PRXamide-like neuropeptide may be released from the abdominal neurohaemal sites beginning 3–4 h following feeding; a time that coincides with the cessation of diuresis. We also show evidence for an endogenous factor,isolated from the central nervous system using reversed-phase high performance liquid chromatography, which mimics the effects of Mas-CAPA-1. Specifically,this endogenous anti-diuretic factor inhibits rates of 5-HT-stimulated secretion in a dose-dependent manner and elevates intracellular cGMP levels of Malpighian tubules stimulated with 5-HT.
Quetiapine for Insomnia Associated with Refractory Depression Exacerbated by Phenelzine
Authors: Sokolski Kenneth N , Brown Brenda J 
Published: February 2006

Objective: To report the successful treatment of phenelzine-associated insomnia with low-dose quetiapine in a patient with refractory depression. Case Summary: A 42-year-old white man with severe major depression unresponsive to selective serotonin-reuptake inhibitors, bupropion, and tricyclic antidepressants improved following treatment with the monoamine oxidase inhibitor (MAOI) phenelzine. Insomnia, present to a moderate degree prior to antidepressant therapy, worsened markedly following phenelzine treatment and failed to respond to diphenhydramine, temazepam, triazolam, clonazepam, Zolpidem, or trazodone given at high therapeutic doses. Sleep disturbance resolved with low-dose (50 mg) adjunctive quetiapine, with no adverse effects. Discussion: Major depression refractory to standard therapy is a common and serious condition. Some cases respond to MAOIs; however, orthostatic hypotension and insomnia frequently occur. Potentially serious MAOI interactions with psychotropic drugs have raised concerns about combining these agents. In this case, a failure of a number of other medications known to treat MAOI-associated insomnia safely prompted a trial of quetiapine. Despite the possibility that enhanced serotonergic activity might have resulted in serotonin syndrome, no adverse interactions between phenelzine and quetiapine were noted. The use of low-dose, once-daily quetiapine, along with its unique binding properties, may account for its increased safety in combination with phenelzine. Conclusions: This case illustrates that low-dose quetiapine may be an alternative treatment for phenelzine-associated insomnia. Further case reports are needed to establish the safety and effectiveness of combining these agents.
Infectious Diseases: Tolerance of Vancomycin for Surgical Prophylaxis in Patients Undergoing Cardiac Surgery and Incidence of Vancomycin-Resistant Enterococcus Colonization
Authors: Kachroo Sumesh , Dao Thanh , Zabaneh Firas , Reiter Margaret , LaRocco Mark T , Gentry Layne O , Garey Kevin W 
Published: February 2006

Background: In 2001, vancomycin replaced cefuroxime for antibiotic prophylaxis in patients undergoing cardiac surgery at our institution due to high rates of surgical site infections caused by methicillin-resistant Staphylococcus spp. However, few data supported the use of vancomycin for surgical prophylaxis. Objective: To determine the tolerance of vancomycin for antibiotic prophylaxis and incidence of vancomycin-resistant Enterococcus (VRE) in cardiac surgery patients. Methods: In 2 separate studies, we assessed the adverse effects in patients given perioperative vancomycin (study 1) and the incidence of VRE in patients given perioperative vancomycin (study 2). Study 1 was a prospective cohort study of patients undergoing coronary artery bypass graft (CABG) or valve replacement surgery given vancomycin (1 dose preoperatively/2 doses postoperatively) for antibiotic prophylaxis between October 2003 and December 2004. Patients were assessed for tolerance to the antibiotic regimen. In study 2, cardiac surgery patients receiving perioperative vancomycin were screened for VRE before therapy and at day 7 of hospitalization. VRE was detected using standard microbiologic procedures. Results: In study 1, 1161 patients (CABG = 75%; valve = 19%; both = 6%) were evaluated. All patients but one (99.9%) were prescribed preoperative vancomycin. Therapy was changed for 34 (2.9%) patients, of which 20 changes were due to physician preference for another antibiotic. The only toxicity that required a change in the vancomycin regimen was red man's syndrome, which was experienced by 9 (0.8%) patients. Four patients did not receive a second postoperative dose due to prior renal insufficiency. Patients were most commonly switched to cefuroxime (n = 26), linezolid (n = 2), cefepime (n = 2), gatifloxacin, cefazolin, levofloxacin, or ceftriaxone (n = 1, each). In study 2, 100 patients were screened for the emergence of VRE colonization. No patient was VRE positive at baseline and 4 (4%) were positive at day 7. Conclusions: Surgical antibiotic prophylaxis with vancomycin was reasonably well tolerated in CABG and valve replacement surgery, with a 4% incidence of VRE colonization.
Frequency of Serum Creatinine Monitoring During Allopurinol Therapy in Ambulatory Patients
Authors: Raebel Marsha A , McClure David L , Simon Steven R , Chan K Arnold , Feldstein Adrianne C , Gunter Margaret J , Lafata Jennifer Elston , Harrold Leslie , Nelson Winnie W , Platt Richard 
Published: February 2006

Background: Allopurinol dosage reduction is recommended in patients with renal dysfunction because drug toxicity risk is increased. Little information is available about serum creatinine (SCr) monitoring in ambulatory patients taking allopurinol. Objective: To evaluate SCr monitoring among patients prescribed allopurinol, identify associated factors, and evaluate administrative data in assessing monitoring. Methods: Information for this retrospective cohort study was drawn from a dataset of 2 020 037 individuals; approximately 200 000 members from each of 10 organizations. Study patients had received at least one year of ongoing allopurinol prescription dispensings. Patient variables analyzed included age, gender, chronic diseases, outpatient visits, hospitalizations, gout diagnosis, and SCr monitoring. A random sample of medical records was reviewed to assess the accuracy of the automated data. Statistical analysis included descriptive and logistic regression techniques. Results: Overall, 1139 (26%) of 4357 patients did not have SCr monitoring. For individuals without recent hospitalization, factors protective against lack of monitoring were increasing age (OR 0.77 per 10 y; 95% CI 0.74 to 0.79), more chronic diseases (OR 0.81; 95% CI 0.78 to 0.83), more outpatient visits (OR 0.87 per 5 visits; 95% CI 0.83 to 0.91), and gout diagnosis (OR 0.74; 95% CI 0.65 to 0.85). The sensitivity and specificity of administrative data compared with medical records for SCr monitoring were 92% and 65%, respectively. Conclusions: More than one-fourth of patients dispensed allopurinol did not have SCr monitoring during one year of therapy. Lack of monitoring and lack of subsequent possible dosage adjustment put patients at increased risk of allopurinol toxicity.
High‐Throughput Real‐Time Quantitative Reverse Transcription PCR
Authors: Bookout Angie L. , Cummins Carolyn L. , Mangelsdorf David J. , Pesola Jean M. , Kramer Martha F. 
Published: February 2006

AbstractExtensive detail on the application of the real‐time quantitative polymerase chain reaction (QPCR) for the analysis of gene expression is provided in this unit. The protocols are designed for high‐throughput, 384‐well‐format instruments, such as the Applied Biosystems 7900HT, but may be modified to suit any real‐time PCR instrument. QPCR primer and probe design and validation are discussed, and three relative quantitation methods are described: the standard curve method, the efficiency‐corrected ΔCt method, and the comparative cycle time, or ΔΔCt method. In addition, a method is provided for absolute quantification of RNA in unknown samples. RNA standards are subjected to RT‐PCR in the same manner as the experimental samples, thus accounting for the reaction efficiencies of both procedures. This protocol describes the production and quantitation of synthetic RNA molecules for real‐time and non‐real‐time RT‐PCR applications.
Use of LINKAGE Programs for Linkage Analysis
Authors: Speer Marcy C. 
Published: February 2006

AbstractGenetic linkage analysis remains a powerful tool for identifying regions of the genome that may harbor suceptibility loci. This unit describes the traditional approach of calculating two‐point and multipoint lod scores when the underlying genetic model is known. Components of the genetic model include whether a trait is dominant, recessive, or codominant, whether it is autosomal or sex linked, and whether there is mutation at the disease gene locus, as well as the disease and marker allele frequencies and the penetrance of the disease allele. The approach to genetic linkage analysis presented in this unit assumes that the markers are loosely spaced, so that there is no linkage disequilibrium between genetic markers. Practical examples and step‐by‐step guidelines are presented.
DNA Mutation Detection Using Denaturing High‐Performance Liquid Chromatography (DHPLC)
Authors: Yu Bing , Sawyer Nicole A. , Chiu Christine , Oefner Peter J. , Underhill Peter A. 
Published: February 2006

AbstractDHPLC is an efficient method for candidate gene scanning with a high level of automation. Single‐base substitutions and insertions or deletions of up to 1.5 kb in PCR amplified DNA fragments can be detected. The method exploits the differential retention of homoduplex and heteroduplex DNA species under conditions of partial thermal denaturation. DHPLC provides a useful platform for high‐throughput mutation detection and SNP discovery.
Characterization of gas crossover and its implications in PEM fuel cells
Authors: Kocha Shyam S. , Deliang Yang J. , Yi Jung S. 
Published: February 2006

AbstractWith pure hydrogen as the fuel, PEM fuel cell operation at or near 100% fuel utilization is desirable to achieve a high stack efficiency and zero emissions. However, typical membranes used in PEM fuel cells allow a finite amount of permeation rates or crossover of hydrogen, oxygen, and nitrogen across the membrane. The hydrogen and oxygen that permeate through the membrane are consumed with the generation of heat and water but without the generating of useful work, leading to a fuel inefficiency. Nitrogen crossover, on the other hand, from the cathode side to the anode side accumulates at the exit of the anode flow fields, lowering the hydrogen concentration and resulting in local fuel starvation. In this study, an in‐situ electrochemical technique has been applied to determine the magnitude of the hydrogen crossover over a range of relevant fuel cell operating temperatures and pressures. Permeability coefficients thus obtained are compared to values reported in the literature. A mathematical model is developed to predict the extent of nitrogen accumulation along the anode flow fields, and fuel recycle as a mitigation method is simulated by improving hydrogen distribution. The model results were validated by comparison with experimental results. © 2006 American Institute of Chemical Engineers AIChE J, 2006
Dynamic modeling of local reaction conditions in an agitated aerobic fermenter
Authors: Laakkonen Marko , Moilanen Pasi , Alopaeus Ville , Aittamaa Juhani 
Published: February 2006

AbstractComputational Fluid Dynamics (CFD) can be used to investigate local reaction rates and gas‐liquid mass transfer in agitated aerobic fermenters, but it is too slow for the simulation of a whole fermentation batch at present computational capabilities. This problem is addressed in the present work by developing a dynamic model with 42 subregions for a 0.64 m3 pilot xanthan fermenter. The model considers local reaction and mass transfer rates in the fermenter and the change of liquid flow fields during the fermentation. Gas‐liquid mass transfer fluxes are calculated based on the simplified solution of Maxwell‐Stefan diffusion by assuming the mass transfer resistance in both the gas and the liquid side of the gas‐liquid interface. Gas‐liquid mass transfer areas are obtained from Population Balances (PB) for bubbles. The comparison of model predictions to the laboratory stirred tank experiments with aqueous xanthan shows the need of local bubble size distributions (BSD) for the description of complex gas‐liquid hydrodynamics and mass transfer. The model predicts the effect of operating conditions on the temporal and spatial variation of BSDs, mass transfer coefficients, dissolved oxygen concentrations, and xanthan reaction rates in the fermenter. It can be used to investigate fermenter operating strategies. The model is also useful for the scale‐up studies. © 2006 American Institute of Chemical Engineers AIChE J, 2006