bluuebunny/crossref_metadata_2025 huggingface dataset:
Foraging patterns of breeding Dolphin GullsLarus scoresbiiat Punta Tombo, Argentina
Authors: SUÁREZ NICOLÁS , YORIO PABLO
Published: June 2005

The Dolphin GullLarus scoresbiiis a little‐known, rare species endemic to southern South America. Knowledge of its feeding ecology is essential for development of management and conservation strategies. To obtain information on their use of food resources and on the frequency and duration of their foraging trips, we followed seven individuals by radiotelemetry during the breeding season of 2002 at the Punta Tombo Reserve, Argentina. In 99% of mapped locations (n = 4069) the Gulls were within 2.4 km of their colony. Dolphin Gulls foraged mostly at the colonies of three other species, feeding on Magellanic PenguinSpheniscus magellanicusand Imperial CormorantPhalacrocorax atricepsregurgitates and on Southern Sea LionOtaria flavescensfaeces. The sea lion colony was the most frequently visited foraging area, accounting for 64% of the total (n = 260 trips). A similar trend was observed during both the incubation (60%,n = 38 trips) and the chick (64%,n = 40 trips) stages. The mean number of trips per day was 3.8 (range = 3–5), with a mean duration of 123 min (sd = ±27). Trip duration differed between foraging areas, being significantly longer at the sea lion than at the penguin and cormorant colonies. The small foraging range given by its particular feeding strategy suggests that Dolphin Gulls, in contrast to most other seabirds that range over large expanses of ocean in search of food, may be effectively conserved within protected areas during the breeding season.
Size and trends of the House Sparrow Passer domesticus population in Great Britain
Authors: ROBINSON ROBERT A. , SIRIWARDENA GAVIN M. , CRICK HUMPHREY Q. P.
Published: June 2005

House Sparrow Passer domesticus populations have declined throughout Europe over the last two to three decades; this is of particular concern in urban areas. We analysed data from extensive census schemes organized by the British Trust for Ornithology to determine the current population size of the House Sparrow in Britain, and to assess long‐term patterns of change, both in the wider countryside and in urban environments. The national breeding population of House Sparrows was estimated at approximately 13 million individuals (95% confidence interval, 11.9–14.8 million), or about six million pairs. Most of these occur in southeast England and densities are greatest in suburban and rural garden habitats. Overall, populations in rural areas have declined by 47% since the mid 1970s, whereas those in urban and suburban areas have declined by about 60%. Changes in farming practices are likely to account for at least some of the decline in the wider countryside, probably related to changes in food resources, with a loss of grain in fields and more secure storage of harvested grain, though these changes are unquantified. In urban areas, there was an earlier period of decline in the first half of the 20th century due to the loss of horse‐drawn transport and generally cleaner streets. The overall national decline since the 1970s masks much heterogeneity in trend among regional populations, and evidence suggests that population processes in the House Sparrow may be relatively fine‐grained.
The effect of body condition on the timing and success of breeding in Little Penguins Eudyptula minor
Authors: ROBINSON SARAH , CHIARADIA ANDRÉ , HINDELL MARK A.
Published: June 2005

We studied the effect of parental body condition on the breeding biology of Little Penguins Eudyptula minor. Daily attendance patterns and body mass were recorded using an Automated Penguin Monitoring System, which collected arrival and departure masses for approximately 200 breeding birds over the 2000 and 2001 breeding seasons. Breeding success varied between the two years; 2000 was a year of average breeding success (fledging 1.07 chicks per pair), and 2001 a year of poor breeding success (fledging 0.53 chicks per pair). In both years, adult body condition (body mass divided by flipper length) increased significantly prior to laying. The laying period began over a month later in 2000 than in 2001, and birds in 2000 exhibited significantly better body condition at laying. However, the mean laying dates in 2000 were less variable than in the 2001 breeding season. Body condition appeared to influence both the time of breeding and breeding synchrony in Little Penguins. Breeding success was correlated with adult body condition at incubation in 2000 but not in 2001, indicating that success was not solely influenced by adult body condition at incubation.
Modelling relationships between birds and vegetation structure using airborne LiDAR data: a review with case studies from agricultural and woodland environments
Authors: BRADBURY RICHARD B. , HILL ROSS A. , MASON DAVID C. , HINSLEY SHELLEY A. , WILSON JEREMY D. , BALZTER HEIKO , ANDERSON GUY Q. A. , WHITTINGHAM MARK J. , DAVENPORT IAN J. , BELLAMY PAUL E.
Published: June 2005

Airborne LiDAR (Light Detection and Ranging) is a remote sensing technology that offers the ability to collect high horizontal sampling densities of high vertical resolution vegetation height data, over larger spatial extents than could be obtained by field survey. The influence of vegetation structure on the bird is a key mechanism underlying bird–habitat models. However, manual survey of vegetation structure becomes prohibitive in terms of time and cost if sampling needs to be of sufficient density to incorporate fine‐grained heterogeneity at a landscape extent. We show that LiDAR data can help bridge the gap between grain and extent in organism–habitat models. Two examples are provided of bird–habitat models that use structural habitat information derived from airborne LiDAR data. First, it is shown that data on crop and field boundary height can be derived from LiDAR data, and so have the potential to predict the distribution of breeding Sky Larks in a farmed landscape. Secondly, LiDAR‐retrieved canopy height and structural data are used to predict the breeding success of Great Tits and Blue Tits in broad‐leaved woodland. LiDAR thus offers great potential for parameterizing predictive bird–habitat association models. This could be enhanced by the combination of LiDAR data with multispectral remote sensing data, which enables a wider range of habitat information to be derived, including both structural and compositional characteristics.
Migraine Headache and Atrial Fibrillation
Authors: Shuaib Ashfaq , Klein Gary , Dear Richard
Published: June 2005

SYNOPSIS

A thirty‐four‐year‐old male, with a ten‐year history of typical common migraine, had, on three occasions, typical migraine headaches which were associated with vomiting. During each of these episodes, atrial fibrillation was documented. Cardiac rhythm was normal between episodes. In this case, we feel that the atrial fibrillation was secondary to an increase in vagal tone resulting from vomiting. We doubt that the migraine itself was responsible for the atrial fibrillation. We propose that the association of migraine and atrial fibrillation be treated by control of vomiting. Where vomiting is hard to control, then atropine given on a prophylactic basis may also be helpful, as atropine is shown to be effective in the prophylaxis of atrial fibrillation when it is secondary to an increase in vagal tone.
A Magnetoencephalographic Study of Patients with Panayiotopoulos Syndrome
Authors: Kanazawa Osamu , Tohyama Jun , Akasaka Noriyuki , Kamimura Takanori
Published: June 2005

Summary: Purpose:Panayiotopoulos syndrome (PS) is a newly identified type of benign childhood epilepsy characterized by ictal vomiting and eye deviation. It is usually accompanied by occipital spike discharges; however, its classification as an early‐onset benign childhood occipital epilepsy is controversial. To characterize this condition further, we examined the localization of equivalent current dipoles (ECDs) of spike discharges by magnetoencephalography (MEG) in patients with PS.

Methods:We studied 13 patients with a mean age at time of examination of 5 years (range, 3–14 years). MEG was measured by using a whole‐head 204‐channel neuromagnetometer with simultaneous EEG recordings. The estimated locations of ECDs of each peak of the spike discharges were overlaid on magnetic resonance images of the brain.

Results:Eleven (84.6%) patients showed clustered ECDs in the areas alongside the parietooccipital sulcus (eight of 13; 61.5%) and/or the calcarine sulcus (four of 13; 30.8%). Despite Fp‐O synchronization of the spike discharges in the scalp EEG of five patients, no frontal locations of ECDs were found. All five (38.5%) boys with sylvian seizures, who also showed clustered ECDs in rolandic areas, had an earlier age at onset and higher seizure frequency than did other patients. ECD orientations were regular in all but one patient, who showed irregular and dispersed ECDs alongside bilateral calcarine sulci.

Conclusions:Our results demonstrate localized cortical hyperexcitability in the areas alongside major cortical sulci in PS and indicate that PS is closely related to benign childhood epilepsy with centrotemporal spikes.
Volumetric Magnetic Resonance Imaging of Functionally Relevant Structural Alterations in Chronic Epilepsy after Pilocarpine‐induced Status Epilepticus in Rats
Authors: Niessen Heiko G. , Angenstein Frank , Vielhaber Stefan , Frisch Christian , Kudin Alexei , Elger Christian E. , Heinze Hans‐Jochen , Scheich Henning , Kunz Wolfram S.
Published: June 2005

Summary:  Purpose: After pilocarpine‐induced epilepsy in rats, volumetric magnetic resonance imaging (MRI) reveals significant morphologic changes in functionally relevant structures of the brain. To relate structural changes to functional alteration, we studied the correlation of regional brain atrophy (e.g., of the hippocampus) with lesion‐induced learning deficits in the Morris water maze.

Methods: MRI experiments were performed on an MR scanner at 4.7 Tesla. For volumetric analysis, various cerebral structures were segmented in horizontal and coronal T2‐weighted MR images. Before the MRI investigations, animals were trained for 10 days in a Morris water maze.

Results: Volumetric MRI revealed a significant loss in hippocampal size in both the dorsal and ventral parts, correlated with an increase in ventricular size. Furthermore, significant losses were found in the relative size of thalamus, putamen, cortex, and the combined areas of perirhinal, entorhinal, and piriform cortices adjacent to the hippocampus. A significant correlation of learning performance in the Morris water maze with the relative hippocampal area and not with other areas tested was observed in pilocarpine‐treated animals.

Conclusions: The data provide a quantitative analysis of functionally relevant structural alterations in rats with chronic epilepsy. Water maze performance of pilocarpine‐treated animals correlates with the degree of hippocampal but not with the degree of cortical damage, demonstrating the potential of this method for the investigation of cognitive impairments in relation to cerebral changes. In addition, the data point to an important role of even the residual hippocampus in memory formation.
Kynurenate and 7‐Chlorokynurenate Formation in Chronically Epileptic Rats
Authors: Wu Hui‐Qiu , Rassoulpour Arash , Goodman Jeffrey H. , Scharfman Helen E. , Bertram Edward H. , Schwarcz Robert
Published: June 2005

Summary:  Purpose: The tryptophan metabolite kynurenic acid (KYNA) and its synthetic derivative, 7‐chlorokynurenic acid (7‐Cl‐KYNA), are antagonists of the glycine co‐agonist (“glycineB”) site of the N‐methyl‐d‐aspartate (NMDA)‐receptor. Both compounds have neuroprotective and anticonvulsive properties but do not readily penetrate the blood–brain barrier. However, KYNA and 7‐Cl‐KYNA can be formed in, and released from, astrocytes after the peripheral administration of their transportable precursors kynurenine and 4‐chlorokynurenine, respectively. The present study was designed to examine these biosynthetic processes, as well as astrogliosis, in animals with spontaneously recurring seizures.

Methods: The fate and formation of KYNA and 7‐Cl‐KYNA was studied in vivo (microdialysis) and in vitro (tissue slices) in rats exhibiting chronic seizure activity (pilocarpine model) and in appropriate controls. Neuronal loss and gliosis in these animals were examined immunohistochemically.

Results: In vivo microdialysis revealed higher ambient extracellular KYNA levels and enhanced de novo formation of 7‐Cl‐KYNA in the entorhinal cortex and hippocampus in epileptic rats. Complementary studies in tissue slices showed increased neosynthesis of KYNA and 7‐Cl‐KYNA in the same two brain areas. Microscopic analysis revealed pronounced astrocytic reactions in entorhinal cortex and hippocampus in epileptic animals.

Conclusions: These results demonstrate that the epileptic brain can synthesize glycineB receptor antagonists in situ. Astrogliosis probably accounts for their enhanced production in chronically epileptic rats. These results bode well for the use of 4‐chlorokynurenine in the treatment of chronic seizure disorders.
Ceramic Composites with Three‐Dimensional Architectures Designed to Produce a Threshold Strength—II. Mechanical Observations
Authors: Fair Geoff E. , He Ming Y. , McMeeking Robert M. , Lange F. F.
Published: June 2005

Finite element modeling and linear elastic fracture mechanics are used to model the residual stresses and failure stress of ceramic composites consisting of polyhedral alumina cores surrounded by thin alumina/mullite layers in residual compression. This type of composite architecture is expected to exhibit isotropic threshold strength behavior, in which the strength of the composite for a particular assumed flaw will be constant and independent of the orientation of tensile loading. The results of the modeling indicate that the strengths of such architectures will be higher than those of laminates of similar architectural dimensions that were previously found to exhibit threshold strength behavior for a particular flaw type. Flexural testing of the polyhedral architectures reveals that failure is dominated by processing defects found at junctions between the polyhedra. Fractography revealed the interaction of these defects with the residual stresses in the compressive layers that separate the polyhedra.
The porA pseudogene of Neisseria gonorrhoeae– low level of genetic polymorphism and a few, mainly identical, inactivating mutations
Authors: UNEMO MAGNUS , NORLÉN OLOV , FREDLUND HANS
Published: June 2005

N. meningitidis is the only Neisseria species known to express two outer membrane porins, PorA and PorB. However, a porA pseudogene has been identified in N. gonorrhoeae. The present study investigated the prevalence and genetic polymorphism of this porA pseudogene in 87 different N. gonorrhoeae strains. The porA pseudogene was identified in all isolates. The pseudogene comprised 12 (5.5%), of which 10 were located in the promoter spacer, and 11 (1.0%) polymorphic nucleotide sites in the upstream segment containing the promoter region, i.e. the putative ‐10 and ‐35 sequences and the promoter spacer in‐between, and the hypothetical PorA coding sequence, respectively. A phylogenetic analysis of the upstream segment and the hypothetical coding sequence identified 36 sequence variants, of which 30 were not previously described. All strains comprised at least two identical confirmed inactivating deletions, of which one was located in the promoter region and one in the hypothetical PorA coding sequence. In conclusion, the porA pseudogene and its few inactivating mutations are widespread in the N. gonorrhoeae population and the homology with the N. meningitidis porA gene reflects their common evolutionary origin. The highly conserved N. gonorrhoeae porA pseudogene may reflect an evolutionary neutral molecular clock and may be a suitable genetic target for diagnosis of N. gonorrhoeae.
A study into the plaque‐inhibitory activity of experimental toothpaste formulations containing antimicrobial agents
Authors: Moran J. , Newcombe R. G. , Wright P. , Haywood J. , Marlow I. , Addy M.
Published: June 2005

Background/Aims: The use of specific antimicrobial agents in toothpastes may help reduce plaque and gingivitis. There would also appear to be some value in formulating products that contain combinations of such agents that may potentiate any activity present. The aims of this exploratory and pragmatic study were twofold:‐ (1) exploratory: to compare the effects on plaque re‐growth of two zinc citrate/triclosan formulations, one of which contained bromochlorophene and hence demonstrate any additional beneficial effects produced by the addition of the phenol. (2) pragmatic: to assess whether both pastes were significantly better than a benchmark control, proprietary fluoride toothpaste at inhibiting plaque formation.

Methods: Following an initial prophylaxis to remove all plaque and calculus, toothpaste slurry rinses were used over a 96 h period by 24 volunteers, while omitting all other oral hygiene procedures. After 24, 48 and 96 h, plaque was measured by plaque area and by plaque index. For comparative purposes, a conventional commercial fluoride toothpaste rinse was also used as a benchmark control in this triple cross‐over double‐blind study.

Results: With one exception, comparisons between the three pastes failed to show any significant differences in plaque accumulation at 96 h whether assessed by plaque index or area. At this time period, significantly more plaque was seen with the zinc citrate paste without bromochlorophene, compared with that of the control paste.

Conclusions: The findings from this study failed to demonstrate a plaque‐inhibitory action from the two novel formulations beyond that of a conventional benchmark toothpaste, although overall levels of plaque formed by the volunteers, especially on the control paste were generally lower than in previous studies. Nevertheless, it remains to be determined whether the test formulations could exert a direct anti‐inflammatory action against gingivitis by way of the triclosan delivery system. Neither test formulation was subsequently marketed.
Antimicrobial profiles of periodontal pathogens isolated from periodontitis patients in the Netherlands and Spain
Authors: Van Winkelhoff A. J. , Herrera D. , Oteo A. , Sanz M.
Published: June 2005

Background and Aim: Antimicrobial resistance of periodontal pathogens towards currently used antibiotics in periodontics has been investigated in a previous study. Microbial resistance in the periodontal microflora was more frequently observed in Spanish patients in comparison with Dutch patients. The aim of the present study was to compare antimicrobial susceptibility profiles of five periodontal bacteria isolated from periodontitis patients in Spain and in the Netherlands.

Material and Methods: Subgingival plaque samples from adult patients with periodontitis were collected and cultured on selective and non‐selective plates. Actinobacillus actinomycetemcomitans, Porphyromonas gingivalis, Prevotella intermedia, Fusobacterium nucleatum and Micromonas micros were isolated and used for minimal inhibitory concentration tests using the Epsilometer (E‐test) technique. Eight different antibiotics were tested on all bacterial isolates. MIC50 and MIC90 values for each antibiotic and each species were determined and the percentage of resistant strains was calculated.

Results: Significantly higher MIC values were noted in Spanish strains of F. nucleatum for penicillin, ciprofloxacin, of P. intermedia for penicillin, amoxicillin and tetracycline, of M. micros for tetracycline, amoxicillin and azithromycin, and of P. gingivalis for tetracycline and ciprofloxacin. Based on breakpoint concentrations, a higher number of resistant strains in Spain were found in F. nucleatum for penicillin, amoxicillin and metronidazole, in Prevotella intermedia for tetracycline and amoxicillin, and in A. actinomycetemcomitans for amoxicillin and azithromycin. Resistance of P. gingivalis strains was not observed for any of the antibiotics tested both in Spain and the Netherlands.

Conclusions: Differences exist in the susceptibility profiles of periodontal pathogens isolated from periodontitis patients in Spain and in the Netherlands. This implicates that antibiotic susceptibility testing is necessary to determine efficacy of antimicrobial agents. Also, clinical studies with antibiotics should take these differences into account. The information from the present study indicates that it may not be possible to develop uniform protocols for usage of antibiotics in the treatment of severe periodontitis in the European Union.
Periodontal wound healing following GTR therapy of dehiscence‐type defects in the monkey: short‐, medium‐ and long‐term healing
Authors: Graziani Filippo , Laurell Lars , Tonetti Maurizio , Gottlow Jan , Berglundh Tord
Published: June 2005

Objective: To describe periodontal wound healing in dehiscence‐type defects following guided tissue re‐generation (GTR) therapy.

Methods: Ten adult Macaca fascicularis monkeys were used. Buccal dehiscence‐type defects were created at the maxillary second pre‐molars and second molars. After 3 months, GTR surgery was performed. The animals were euthanized at 6 weeks, 6 months and 2 years after surgery. Block biopsies were harvested, and prepared for histological analysis.

Results: A new attachment apparatus was structured already after 6 weeks of healing. A 10–20 μm thin layer of acellular extrinsic fibre cementum (AEFC) had formed along the instrumented root surface. At 6 months, the thickness of the supracrestal cementum was comparable with that at 6 weeks, while the thickness of the subcrestal cementum had increased to 40–60 μm. In this zone, the cementum consisted of an inner layer of AEFC attached to the circum–pulpal dentin and an outer layer of cellular mixed fibre cementum (CMFC). The numerical extrinsic fibre density was twice that at 6 weeks. At 2 years, the periodontal tissues resembled the pristine periodontium.

Conclusion: Periodontal healing following GTR therapy of recession‐type defects will result in a restitutio ad integrum, i.e. healing by re‐generation. A continuous maturation process occurs over at least 2 years.
Septins: Traffic Control at the Cytokinesis Intersection
Authors: Joo Emily , Tsang Christopher W. , Trimble William S.
Published: June 2005

The physical division of one cell into two requires the highly orchestrated separation of genetic and cytoplasmic contents during M phase of the cell cycle. Mitosis, the physical segregation of the genetic material of a cell into two daughter cells, has traditionally received more attention than cytokinesis, the partitioning of the cytoplasmic contents, yet clearly the two processes must be intimately co‐ordinated and tightly regulated. While plant cells divide by the formation of a membranous cell barrier called the phragmoplast, animal cell division is largely driven by contraction of an actomyosin ring. However, recent evidence has suggested that membranes derived from one or more intracellular compartments are also required to break the cytoplasmic bridge connecting two dividing cells during late telophase. In this review, we focus on studies of animal cell cytokinesis that support a requirement for specific endomembrane fusion during fission, define molecular components of the membrane fusion apparatus that may be involved and point to possible roles for an emerging family of cytoskeletal proteins, the septins, in this process.
FINITE PRESENTABILITY OF HNN EXTENSIONS OF INVERSE SEMIGROUPS
Authors: DOMBI E. R. , GILBERT N. D. , RUŠKUC N.
Published: June 2005

HNN extensions of inverse semigroups, where the associated inverse subsemigroups are order ideals of the base, are defined by means of a construction based upon the isomorphism between the categories of inverse semigroups and inductive groupoids. The resulting HNN extension may conveniently be described by an inverse semigroup presentation, and we determine when an HNN extension with finitely generated or finitely presented base is again finitely generated or finitely presented. Our main results depend upon properties of the [Formula: see text]-preorder in the associated subsemigroups. Let S be a finitely generated inverse semigroup and let U, V be inverse subsemigroups of S, isomorphic via φ: U → V, that are order ideals in S. We prove that the HNN extension S*U,φ is finitely generated if and only if U is finitely [Formula: see text]-dominated. If S is finitely presented, we give a necessary and suffcient condition for S*U,φ to be finitely presented. Here, in contrast to the theory of HNN extensions of groups, it is not necessary that U be finitely generated.
A NOTE ON THE GRAMMAR OF COMBINGS
Authors: BRIDSON MARTIN R.
Published: June 2005

Explicit constructions are given to illustrate the loss of control that ensues when one replaces the regular languages of automatic group theory with larger families of languages.
ELEMENTS OF PRIME POWER ORDER IN RESIDUALLY FINITE GROUPS
Authors: SHUMYATSKY PAVEL
Published: June 2005

Let G be a residually finite group satisfying some identity w ≡ 1. Suppose G is generated by a normal commutator-closed set X of p-elements. We prove that G is locally finite.
THE DEATH PENALTY MEETS SOCIAL SCIENCE: Deterrence and Jury Behavior Under New Scrutiny
Authors: Weisberg Robert
Published: June 2005

▪ Abstract  Social science has long played a role in examining the efficacy and fairness of the death penalty. Empirical studies of the deterrent effect of capital punishment were cited by the Supreme Court in its landmark cases in the 1970s; most notable was the 1975 Isaac Ehrlich study, which used multivariate regression analysis and purported to show a significant marginal deterrent effect over life imprisonment, but which was soon roundly criticized for methodological flaws. Decades later, new econometric studies have emerged, using panel data techniques, that report striking findings of marginal deterrence, even up to 18 lives saved per execution. Yet the cycle of debate continues, as these new studies face criticism for omitting key potential variables and for the potential distorting effect of one anomalously high-executing state (Texas). Meanwhile, other empiricists, relying mainly on survey questionnaires, have taken a fresh look at the human dynamics of death penalty trials, especially the attitudes and personal background factors that influence capital jurors.
No effect of short-term testosterone manipulation on exercise substrate metabolism in men
Authors: Braun Barry , Gerson Laura , Hagobian Todd , Grow Daniel , Chipkin Stuart R.
Published: June 2005

Compared with women, men use proportionately more carbohydrate and less fat during exercise at the same relative intensity. Estrogen and progesterone have potent effects on substrate use during exercise in women, but the role of testosterone (T) in mediating substrate use is unknown. The purpose of this investigation was to assess how large variations in the concentration of blood T would impact substrate use during exercise in men. Nine healthy, active men were studied in three distinct hormonal conditions: physiological T (no intervention), low T (pharmacological suppression of endogenous T with a gonadotrophin-releasing hormone antagonist), and high T (supplementation with transdermal T). Total carbohydrate oxidation, blood glucose rate of disappearance, and estimated muscle glycogen use were assessed by using stable isotope dilution and indirect calorimetry at rest and while bicycling at ∼60% of peak O2 consumption for 90 min. Relative to the physiological condition (T = 5.5 ± 0.5 ng/ml), total plasma T was considerably suppressed in low T (0.8 ± 0.1) and elevated in high T (10.9 ± 1.1). Despite the large changes in plasma T, carbohydrate oxidation, glucose rate of disappearance, and estimated muscle glycogen use were very similar across the three conditions. There were also no differences in plasma concentrations of glucose, insulin, lactate, or free fatty acids. Plasma estradiol (E) concentrations were elevated in high T, but correlations between substrate use and plasma concentrations of T, E, or the T-to-E ratio were very weak ( r2 < 0.20). In conclusion, unlike the effect of acute elevation in E to constrain carbohydrate use in women, acute changes in circulating T concentrations do not appear to alter substrate use during exercise in men.
Serotonin Modulates Axo-Axonal Coupling Between Neurons Critical for Learning in the Leech
Authors: Moss Brenda L. , Fuller Abby D. , Sahley Christie L. , Burrell Brian D.
Published: June 2005

S cells form a chain of electrically coupled neurons that extends the length of the leech CNS and plays a critical role in sensitization during whole-body shortening. This process requires serotonin, which acts in part by altering the pattern of activity in the S-cell network. Serotonin-containing axons and varicosities were observed in Faivre's nerve where the S-to-S-cell electrical synapses are located. To determine whether serotonin modulates these synapses, S-cell action-potential (AP) propagation was studied in a two-ganglion chain containing one electrical synapse. Suction electrodes were placed on the cut ends of the connectives to stimulate one S cell while recording the other, coupled S cell's APs. A third electrode, placed en passant, recorded the APs near the electrical synapse before they propagated through it. Low concentrations of the gap junction inhibitor octanol increased AP latency across the two-ganglion chain, and this effect was localized to the region of axon containing the electrical synapse. At higher concentrations, APs failed to propagate across the synapse. Serotonin also increased AP latency across the electrical synapse, suggesting that serotonin reduced coupling between S cells. This effect was independent of the direction of propagation and increased with the number of electrical synapses in progressively longer chains. Furthermore, serotonin modulated instantaneous AP frequency when APs were initiated in separate S cells and in a computational model of S-cell activity after mechanosensory input. Thus serotonergic modulation of S-cell electrical synapses may contribute to changes in the pattern of activity in the S-cell network.
Subtype-Specific GABA Transporter Antagonists Synergistically Modulate Phasic and Tonic GABAAConductances in Rat Neocortex
Authors: Keros Sotirios , Hablitz John J.
Published: June 2005

GABAergic inhibition in the brain can be classified as either phasic or tonic. γ-Aminobutyric acid (GABA) uptake by GABA transporters (GATs) can limit the time course of phasic currents arising from endogenous and exogenous GABA, as well as decrease a tonically active GABA current. GABA transporter subtypes 1 and 3 (GAT-1 and GAT-3) are the most heavily expressed of the four known GAT subtypes. The role of GATs in shaping GABA currents in the neocortex has not been explored. We obtained patch-clamp recordings from layer II/III pyramidal cells and layer I interneurons in rat sensorimotor cortex. We found that selective GAT-1 inhibition with NO711 decreased the amplitude and increased the decay time of evoked inhibitory postsynaptic currents (IPSCs) but had no effect on the tonic current or spontaneous IPSCs (sIPSCs). GAT-2/3 inhibition with SNAP-5114 had no effect on IPSCs or the tonic current. Coapplication of NO711 and SNAP-5114 substantially increased tonic currents and synergistically decreased IPSC amplitudes and increased IPSC decay times. sIPSCs were not resolvable with coapplication of NO711 and SNAP-5114. The effects of the nonselective GAT antagonist nipecotic acid were similar to those of NO711 and SNAP-5114 together. We conclude that synaptic GABA levels in neocortical neurons are controlled primarily by GAT-1, but that GAT-1 and GAT-2/3 work together extrasynaptically to limit tonic currents. Inhibition of any one GAT subtype does not increase the tonic current, presumably as a result of increased activity of the remaining transporters. Thus neocortical GAT-1 and GAT-2/3 have distinct but overlapping roles in modulating GABA conductances.
Dynamics of a continued fraction of Ramanujan with random coefficients
Authors: Borwein Jonathan M. , Luke D. Russell
Published: June 2005

We study a generalization of a continued fraction of Ramanujan with random, complex‐valued coefficients. A study of the continued fraction is equivalent to an analysis of the convergence of certain stochastic difference equations and the stability of random dynamical systems. We determine the convergence properties
of stochastic difference equations and so the divergence of their corresponding continued fractions.
On typical Markov operators acting on Borel measures
Authors: Szarek Tomasz
Published: June 2005

It is proved that, in the sense of Baire category, almost every Markov operator acting on Borel measures is asymptotically stable and the Hausdorff dimension of its invariant measure is equal to zero.
On σ‐porous sets in abstract spaces
Authors: Zajíček L.
Published: June 2005

The main aim of this survey paper is to give basic information about properties and applications of
σ‐porous sets in Banach spaces (and some other infinite‐dimensional spaces). This paper can be considered a partial continuation of the author′s 1987 survey on porosity and σ‐porosity and therefore only some results, remarks, and references (important for infinite‐dimensional spaces) are repeated. However, this paper can be used without any knowledge of the previous survey. Some new results concerning σ‐porosity in finite‐dimensional spaces are also briefly mentioned. However, results concerning porosity (but not σ‐porosity) are mentioned only exceptionally.
Nielsen number and differential equations
Authors: Andres Jan
Published: June 2005

In reply to a problem of Jean Leray (application of the Nielsen theory to differential equations), two main approaches are presented. The first is via Poincaré's translation operator, while the second one is based on the Hammerstein-type solution operator. The applicability of various Nielsen theories is discussed with respect to several sorts of differential equations and inclusions. Links with the Sharkovskii-like theorems (a finite number of periodic solutions imply infinitely many subharmonics) are indicated, jointly with some further consequences like the nontrivial "Equation missing"-structure of solutions of initial value problems. Some illustrating examples are supplied and open problems are formulated.
A note on well-posed null and fixed point problems
Authors: Reich Simeon , Zaslavski Alexander J
Published: June 2005

We establish generic well-posedness of certain null and fixed point problems for ordered Banach space-valued continuous mappings.
On the global solvability of solutions to a quasilinearwave equation with localized damping and source terms
Authors: Lapa E. Cabanillas , Segura Z. Huaringa , Barboza F. Leon
Published: June 2005

We prove existence and uniform stability of strong solutions to a
quasilinear wave equation with a locally distributed nonlinear dissipation with source term of power nonlinearity of
the type u″ − M(∫Ω|∇u|2dx)Δu + a(x)g(u′) + f(u) = 0, in Ω × ]0, +∞[, u = 0, on Γ × ]0, +∞[, u(x, 0) = u0(x), u′(x, 0) = u1(x), in Ω.
Classification and Selection of Biomarkers in Genomic Data Using LASSO
Authors: Ghosh Debashis , Chinnaiyan Arul M.
Published: June 2005

High‐throughput gene expression technologies such as microarrays have been utilized in a variety of scientific applications. Most of the work has been done on assessing univariate associations between gene expression profiles with clinical outcome (variable selection) or on developing classification procedures with gene expression data (supervised learning). We consider a hybrid variable selection/classification approach that is based
on linear combinations of the gene expression profiles that maximize an accuracy measure summarized using the receiver operating characteristic curve. Under a specific probability model, this leads to the consideration of linear discriminant functions. We incorporate an automated variable selection approach using LASSO. An equivalence between LASSO estimation with support vector machines allows for model fitting using standard software. We apply the proposed method to simulated data as well as data from a recently published prostate cancer study.
Gene Expression Data Classification With Kernel Principal Component Analysis
Authors: Liu Zhenqiu , Chen Dechang , Bensmail Halima
Published: June 2005

One important feature of the gene expression data is that the number of genes M far exceeds the number of samples N. Standard statistical methods do not work well when N < M. Development of new methodologies or modification of existing methodologies is needed for the analysis of the microarray data. In this paper, we propose a novel analysis procedure for classifying the gene expression data. This procedure involves dimension reduction using kernel principal component analysis (KPCA) and classification with logistic regression (discrimination). KPCA is a generalization and nonlinear version of principal component analysis. The proposed algorithm was applied to five different gene expression datasets involving human tumor samples. Comparison with other popular classification methods such as support vector machines and neural networks shows that our algorithm is very promising in classifying gene expression data.
Cardiovascular Damage in Alzheimer Disease: Autopsy Findings From the Bryan ADRC
Authors: Corder Elizabeth H. , Ervin John F. , Lockhart Evelyn , Szymanski Mari H. , Schmechel Donald E. , Hulette Christine M.
Published: June 2005

Autopsy information on cardiovascular damage was investigated for pathologically confirmed Alzheimer disease (AD) patients (n = 84) and non‐AD control patients (n = 60). The 51 relevant items were entered into a grade‐of‐membership model to describe vascular damage in AD. Five latent groups were identified “I: early‐onset AD,” “II: controls, cancer,” “III: controls, extensive atherosclerosis,” “IV: late‐onset AD, male,” and “V:
late‐onset AD, female.” Expectedly, Groups IV and V had elevated APOEε4 frequency. Unexpectedly, there was limited atherosclerosis and frequent myocardial valve and ventricular damage. The findings do not indicate a strong relationship between atherosclerosis and AD, although both are
associated with the APOEε4. Instead, autopsy findings of extensive atherosclerosis were associated with possible, not probable or definite AD, and premature death. They are consistent with the hypothesis that brain hypoperfusion contributes to dementia, possibly to AD pathogenesis, and raise the possibility that the APOE allele ε4 contributes directly to heart valve and myocardial damage.
High‐Betweenness Proteins in the Yeast Protein Interaction Network
Authors: Joy Maliackal Poulo , Brock Amy , Ingber Donald E. , Huang Sui
Published: June 2005

Structural features found in biomolecular networks that are absent in random networks produced by simple algorithms can provide insight into the function and evolution of cell regulatory networks. Here we analyze “betweenness” of network nodes, a graph theoretical centrality measure, in the yeast protein interaction network. Proteins that have high betweenness, but low connectivity (degree), were found to be abundant in the yeast proteome. This finding is not explained by algorithms proposed to explain the scale‐free property of protein interaction networks, where low‐connectivity proteins also have low betweenness. These data suggest the existence of some modular organization of the network, and that the high‐betweenness, low‐connectivity proteins may act as important links between these modules. We found that proteins with high betweenness are more likely to be essential and that evolutionary age of proteins is positively correlated with betweenness. By comparing different models of genome evolution that generate scale‐free networks, we show that rewiring of interactions via mutation is an important factor in the production of such proteins. The evolutionary and functional significance of these observations are discussed.
Effects of group singing and performance for marginalized and middle-class singers
Authors: Bailey Betty A. , Davidson Jane W.
Published: June 2005

In western society music performance is generally considered from the perspective of the elite performer, and the performance literature within the psychology of music has been representative of this preoccupation. But, in spite of much attention being directed to the ‘how’ of creating exceptional performances, little attention has been given to the ‘why’ of performance. Results of an investigation with members of a choir for homeless men indicated that group singing and performance, at the most amateur levels of musicality, yielded considerable emotional, social and cognitive benefits. The present article further explores the effects of group singing and performance with (a) a second choir formed for homeless and other marginalized individuals who had little or no music training or group singing experience, and (b) middle-class singers with low to high levels of music training and choral singing experience. Results indicate that the emotional effects of participation in group singing are similar regardless of training or socioeconomic status, but the interpersonal and cognitive components of the choral experience have different meanings for the marginalized and middle-class singers. Whereas the marginalized individuals appear to embrace all aspects of the group singing experience, the middle-class choristers are inhibited by prevalent social expectations of musicianship. The outcomes may be of relevance to music educators, therapists and choral conductors who wish to create a choral environment in which the benefits of singing and performance override elitist concerns.
A selective cyclic integrin antagonist blocks the integrin receptors αvβ3 and αvβ5and inhibits retinal pigment epithelium cell attachment, migration and invasion
Authors: Hoffmann Stephan , He Shikun , Jin Manlin , Ehren Marianne , Wiedemann Peter , Ryan Stephen J , Hinton David R
Published: June 2005

Background

Proliferative vitreoretinopathy (PVR) is a leading cause of blindness after failed retinal reattachment surgery. PVR is characterized by the proliferation, migration and contraction of retinal pigmented epithelial cells (RPE), and these cellular responses are influenced by the expression and function of integrin receptors. The effect of a cyclic integrin antagonist containing the amino acid sequence Arg-Gly-Asp-D-Phe-Val (RGDfV), specific for the integrin receptors αvβ3 and αvβ5, was investigated on basic fibroblast growth factor (bFGF), platelet derived growth factor-BB (PDGF-BB), and serum induced human RPE proliferation, migration, invasion and attachment to the extracellular matrix. Furthermore, the effects of bFGF and PDGF-BB regulated expression of integrins αvβ3 and αvβ5 on RPE cells was examined.

Methods

The effect of a cyclic integrin antagonist and a control peptide (0.01 μg/ml to 300 μg/ml) was investigated on serum or cytokine (bFGF or PDGF-BB pretreatment) induced human fetal RPE cell proliferation by H3-thymidine uptake. The effect of the cyclic integrin antagonist on RPE cell attachment onto different extracellular matrices (laminin, collagen IV, fibronectin), RPE cell invasion stimulated by PDGF-BB or serum, and migration stimulated by PDGF-BB, vascular endothelial growth factor (VEGF) or serum was explored. PDGF-BB and bFGF modulation of the integrin receptors αvβ3 and αvβ5 was evaluated by flow cytometry.

Results

The integrin antagonist did not inhibit DNA synthesis stimulated by serum, bFGF, or PDGF-BB treatment. RPE attachment onto fibronectin was inhibited in a concentration range of 1–10 μg/ml (p < 0.05). Attachment of the RPE cells onto collagen IV and laminin was inhibited in a range of 3–10 μg/ml (p < 0.05). Serum and PDGF-BB stimulated migration was inhibited by the cyclic integrin antagonist in a concentration range of 1–10 μg/ml (p < 0.05). Furthermore, the cyclic integrin antagonist inhibited PDGF-BB stimulated RPE cell invasion through fibronectin (3μg/ml: 66% inhibition, p < 0.001). In each of these experiments, the control peptides had no significant effects. PDGF-BB and bFGF pretreatment of RPE cells increased the expression of integrin receptors αvβ3 (bFGF: 1.9 fold, PDGF-BB: 2.3 fold) and αvβ5 (bFGF: 2.9 fold, PDGF-BB: 1.5 fold).

Conclusion

A selective inhibition of the integrin receptors αvβ3 and αvβ5 through a cyclic integrin antagonist is able to inhibit RPE cell attachment, migration and invasion. Since these steps are of importance for the progression of PVR, a cyclic integrin antagonist should be further evaluated for the treatment of this disease.
Benign gastro-bronchial fistula – an uncommon complication of esophagectomy: case report
Authors: Devbhandari Mohan P , Jain Rohit , Galloway Simon , Krysiak Piotr
Published: June 2005

Background

Gastro-bronchial fistula (GBF) is a rare and devastating complication following esophagectomy. Making the correct diagnosis is difficult and there is no agreement on the treatment for this rare condition.

Case presentation

We report the case of a 56-year-old man who presented with features of repeated aspiration and chest infections six years following an esophagectomy for Barrett's esophagus. Despite extensive investigations the cause of symptoms was difficult to determine. The correct diagnosis of fistula from stomach to right main stem bronchus was made at bronchoscopy under general anesthesia. After ruling out local recurrence of cancer, a successful primary repair was carried out by resection of fistula and direct repair of gastric conduit and bronchus. He is well after 6 months of treatment.

Conclusion

Late development of gastro-bronchial fistula is a rare complication of esophageal resection that may be difficult to diagnose.

Surgical resection and direct closure is the treatment of choice, although the method of treatment should be tailored according to the anatomy of the fistula and the patient's condition.
Development of a Multiple-Locus Variable number of tandem repeat Analysis (MLVA) for Leptospira interrogans and its application to Leptospira interrogans serovar Australis isolates from Far North Queensland, Australia
Authors: Slack Andrew T , Dohnt Michael F , Symonds Meegan L , Smythe Lee D
Published: June 2005

Background

Leptospirosis is a zoonotic disease caused by the genus, Leptospira. Leptospira interrogans is the most common genomospecies implicated in the disease. Epidemiological investigations are needed to distinguish outbreak situations or to trace reservoirs of the organisms. Current methodologies used for typing Leptospira have significant drawbacks. The development of an easy to perform yet high resolution method is needed for this organism.

Methods

In this study we have searched the available genomic sequence of L. interrogans serovar Copenhageni strain Fiocruz L1-130 for the presence of tandem repeats [1]. These repeats were evaluated against reference strains for diversity. Six loci were selected to create a Multiple Locus Variable Number of Tandem Repeats (VNTR) Analysis (MLVA) to explore the genetic diversity within L. interrogans serovar Australis clinical isolates from Far North Queensland.

Results

The 39 reference strains used for the development of the method displayed 39 distinct patterns. Diversity Indexes for the loci varied between 0.80 and 0.93 and the number of repeat units at each locus varied between less than one to 52 repeats. When the MLVA was applied to serovar Australis isolates three large clusters were distinguishable, each comprising various hosts including Rattus species, human and canines.

Conclusion

The MLVA described in this report, was easy to perform, analyse and was reproducible. The loci selected had high diversity allowing discrimination between serovars and also between strains within a serovar. This method provides a starting point on which improvements to the method and comparisons to other techniques can be made.