bluuebunny/crossref_metadata_2025_split huggingface dataset:
Relation between sodium concentration, electrical potential and transfer capacity of rat small intestine
Authors: Barry R. J. C. , Eggenton Jacqueline , Smyth D. H. , Wright E. M. 
Published: December 2014

1. A study has been made of the effect of Na replacement in the incubation media on the hexose‐dependent potential and the capacity of sacs of rat intestine to transfer fluid and galactose.2. Replacement of NaCl with mannitol or Tris Cl had little effect on the hexose‐dependent potential, while replacement with LiCl and KCl had an inhibitory effect on the potential.3. Replacement with KCl, LiCl, mannitol and Tris Cl all reduced the capacity to transfer fluid and galactose, but the effects of Li and K replacement were greater than mannitol or Tris replacement.4. There is not a fixed relation between the magnitude of the potential and the amount of galactose transferred.
Neurohypophysial peptide interaction with magnesium in avian vascular smooth muscle*
Authors: Somlyo Andrew P. , Somlyo Avril V. , Woo Chi-Yuan 
Published: December 2014

1. The contractile responses of helically cut vascular strips of chickens to vasoactive agents were studied.2. Large pulmonary arteries were contracted by neurohypophysial peptides, but not by angiotensin, acetylcholine, histamine, 5‐hydroxytryptamine, bradykinin or eledoisin. The activity of oxytocin was greater than that of arginine vasopressin.3. Vasodilator effects of oxytocin upon small (200‐500 μ diameter) mesenteric and muscular arteries were demonstrable, but inconsistent.4. Magnesium potentiated in a parallel fashion the vasoconstrictor effects of oxytocin and of arginine vasopressin.5. Deamino‐oxytocin was potentiated by magnesium. This finding suggests a difference between the peptide‐protein interactions of tissue receptors and those of neurophysin.
Factors influencing contraction and catch in Mytilus smooth muscle
Authors: Twarog Betty M. 
Published: December 2014

1. Conditions are defined which determine the level of catch after acetylcholine stimulation of Mytilus muscle.2. Catch tension in dissected muscle is absent when connexions with ganglia are intact.3. Catch tension is absent at temperatures above 30° C.4. Catch tension decreases when intervals between stimuli are increased.5. Increasing concentrations of 5‐hydroxytryptamine (5‐HT) from 10−8
M to 10−6
M quantitatively decreases catch tension.6. The length—tension curve of ganglion‐free Mytilus muscle bundles suggests that catch tension varies in proportion to the tension developed in contraction.7. External Ca2+ concentration has no selective influence on catch.8. All factors which reduce catch also increase muscle excitability, suggesting that catch may depend on a mechanism controlling the intracellular concentration of an activator such as Ca2+.
Analysis of the activity of one type of spontaneously discharging unit in the cortex cerebri of the anaesthetized rat
Authors: Holmes O. , Houchin Jane 
Published: December 2014

1. Extracellular records from one type of spontaneously active element in the cortex of rats anaesthetized with urethane have been analysed statistically.2. Intensity functions reveal that the frequency of discharge of a unit tends to be modulated periodically, the period being 1½‐2 sec under fairly deep anaesthesia. When anaesthesia becomes lighter, long intervals occur rarely; the unitary discharge becomes less regular and the intensity function becomes flat. Variations in depth of anaesthesia are accompanied by changes in amplitude of the periodic modulation; the period of the modulation is not significantly altered.3. Summed interval histograms indicate that the long intervals are separated by groups of short intervals in a significantly regular fashion. The number of short intervals in a group varies from one to about fifteen, according to the mean frequency of discharge of the unit.4. Serial correlation coefficients reflect the observations of 2 and 3 above but indicate no additional serial correlation. The existence of long intervals obscures any serial patterning of short intervals during bursts.5. Simultaneous records from two units show that the periods of activity in the two units are highly synchronized.6. It is probable that all these features are due to a process which causes periodic synchronous excitability changes of all the spontaneously active elements of the type studied.
The districution of biogenic amines in the carotid bifurcation region
Authors: Rees P. M. 
Published: December 2014

1. The distribution of phenolic amines in the carotid body and of adrenergic nerves in the arterial walls of the carotid bifurcation region was investigated histochemically using the phenolic amine‐formaldehyde gas condensation reaction, with supplementary electron microscopical examination. Studies were conducted on normal rabbits and on rabbits after superior cervical ganglionectomy.2. The glomus cells of the carotid body contain phenolic amines. The cellular amine persists after long‐term sympathetic ganglionectomy.3. The blood vessels supplying the carotid body receive an adrenergic innervation which disappears following superior cervical ganglionectomy.4. The walls of the carotid sinus contain adrenergic nerve fibres derived from the superior cervical ganglion.5. There is no penetration of the arterial tunica media by vasomotor fibres in any part of the carotid bifurcation region.6. Ultimate terminations of adrenergic nerves upon smooth muscle occur across the medio‐adventitial border of the common, internal and external carotid arterial walls but only in relation to smooth‐muscle cells in the adventitia of the carotid sinus wall.
Fast and slow muscles of the chick after nerve cross‐union
Authors: Hník P. , Jirmanová Isa , Vyklický L. , Zelená Jiřina 
Published: December 2014

1. The multiply innervated anterior latissimus dorsi (ALD) and the focally innervated posterior latissimus dorsi (PLD) muscles of the chick were investigated 2‐18 months after nerve cross‐union.2. The fast PLD muscle re‐innervated by the slow muscle nerve became supplied with ‘en grappe’ end‐plates and responded to a single nerve volley with local potentials only. Control PLD muscles re‐innervated by the original nerve, had ‘en plaque’ end‐plates and responded to a single nerve volley by synchronous action potentials in the same way as normal muscles.3. In the slow ALD muscle re‐innervated with the ‘mixed’ PLD nerve, the type of innervation and of electromyographic response remained practically unchanged, with the exception of transplanted ALD muscles supplied with PLD nerves where, in addition to local responses, propagated action potentials were registered electromyographically in response to single nerve volleys.4. ALD muscles of young chickens re‐innervated both with an implanted purely fast muscle nerve and with the regenerated original nerve, had two types of innervation: ‘en plaque’ end‐plates around the nerve implant, and multiple ‘en grappe’ end‐plates in areas supplied with the ALD nerve. Accordingly, propagated action potentials were registered in response to single nerve volleys in regions near the implant, whereas local potentials were recorded in areas with original innervation.5. Contraction velocity was not substantially altered in PLD and ALD muscles after nerve cross‐union.6. No changes were observed in the fine structure of muscle fibres in extrajunctional regions.
The neural mechanism of binocular depth discrimination
Authors: Barlow H. B. , Blakemore C. , Pettigrew J. D. 
Published: December 2014

1. Binocularly driven units were investigated in the cat's primary visual cortex.2. It was found that a stimulus located correctly in the visual fields of both eyes was more effective in driving the units than a monocular stimulus, and much more effective than a binocular stimulus which was correctly positioned in only one eye: the response to the correctly located image in one eye is vetoed if the image is incorrectly located in the other eye.3. The vertical and horizontal disparities of the paired retinal images that yielded the maximum response were measured in 87 units from seven cats: the range of horizontal disparities was 6·6°, of vertical disparities 2·2°.4. With fixed convergence, different units will be optimally excited by objects lying at different distances. This may be the basic mechanism underlying depth discrimination in the cat.
The breakdown of adenosine triphosphate in the contraction cycle of the frog sartorius muscle
Authors: Mommaerts W. F. H. M. , Wallner A. 
Published: December 2014

1. It is confirmed that a fluorodinitrobenzene (FDNB)‐treated frog sartorius muscle does not split phosphorylcreatine in the course of its contraction cycle, but does use adenosine triphosphate (ATP).2. Good stoicheiometric relations between the diminution of ATP and the formation of adenosine diphosphate (ADP), adenosine monophosphate (AMP) and phosphate are obtained, and in a 0·2 sec tetanus at 0° C the net break‐down of ATP amounts to 0·27, the total equivalent break‐down to 0·34 μmoles/g.3. There is no difference in this quantity between muscles interrupted at the height of contraction and those that have also relaxed, and, in experiments specifically designed to determine relaxation metabolism separately, no such metabolism is found. Thus, all the ATP‐break‐down occurs in the contraction phase.
Central temperature regulation in the conscious rabbit after monoamine oxidase inhibition
Authors: Cranston W. I. , Rosendorff C. 
Published: December 2014

1. Measured thermal loads were applied to conscious rabbits by intravenous infusions of hot or cold saline. The responses of the central temperature regulating mechanism were assessed by measuring hypothalamic temperature change. The relationship between thermal load and temperature response was established in normal animals.2. Intramuscular injection of tranylcypromine (20 mg/kg. day for 6‐8 days) had no effect upon resting temperature or the temperature response to thermal loads, though the diencephalic concentrations of noradrenaline and 5‐hydroxytryptamine (5‐HT) were increased.3. Either hypothalamic monoamines are not concerned in the regulation of normal temperature or there is a monoamine ‘pool’ in the hypothalamus which is concerned with temperature regulation but which is unaffected by monoamine oxidase inhibition.
Thermal stimulation of hypothalamic neurones in unanaesthetized rabbits
Authors: Hellon R. F. 
Published: December 2014

1. A technique has been devised for recording unit activity in the anterior hypothalamus of conscious rabbits during the controlled displacement of local temperature by 1‐2° C. The region at 1 and 2 mm from the mid line was explored.2. All the units studied showed spontaneous activity before thermal stimulation with a mean rate of 9 impulses/sec (range 1/16 sec to 65/sec).3. Twenty‐seven (10%) of the recorded neurones showed a change in firing rate which could be related to the temperature changes. Twenty‐one of the cells were ‘warm‐sensitive’ and were excited when temperature was raised or inhibited when it was lowered. The other six units were ‘cold‐sensitive’ and showed the opposite type of response.4. Apart from this directional grouping, it was possible to classify the responses into four categories: A, five cells whose firing rate was always proportional to local temperature over a range from 2° C below to 2° C above body temperature; B, six cells whose average level of firing changed during the period of observation, but whose sensitivity to temperature was not affected; C, eight cells which showed a threshold and were only affected by temperature above or below a certain level; D, four cells whose changes in frequency either led or lagged behind the temperature changes.5. The positions of these sensitive units in the hypothalamus did not show any apparent pattern, except that 75% of them were found 1 mm lateral to the mid line; the remaining 25% were 2 mm lateral.
Histamine in the plasma and gastric juice of cats during infusions of [14C]histamine
Authors: Born G. V. R. , Sewing K.-Fr. 
Published: December 2014

1. In anaesthetized cats with gastric fistulae, the relation was investigated between the rate of gastric secretion and the histamine contents of the plasma and the gastric juice during intravenous infusions of [14C]histamine for 3 hr.2. In the first hour only, some endogenous histamine appeared in the gastric juice.3. There was no quantitative relation between the histamine that was infused and that which appeared in the gastric juice.4. There was no correlation between the rate of gastric secretion and the concentration of histamine in either plasma or gastric juice.5. It was concluded that the secretion of histamine into the gastric juice was not essential to gastric secretion.
The uptake of amines by human erythrocytes in vitro
Authors: Born G. V. R. , Day Margaret , Stockbridge Anne 
Published: December 2014

1. Human erythrocytes incubated at 37° C in Krebs bicarbonate solution at pH 7·5 took up 5‐hydroxytryptamine, histamine and (‐)‐noradrenaline at slow rates which were proportional to the concentration of the amines in the medium at least up to 16 μg/ml., in accordance with a simple diffusion process.2. The initial velocity of uptake was greatest for 5‐hydroxytryptamine, about 4 times less for histamine and about 20 times less for (‐)‐noradrenaline; (+)‐noradrenaline was not taken up.3. Comparison of uptake measurements by bio‐assay and by radioactivity indicated that, after 1 hr, about 10% of each amine taken up had been inactivated.4. At 2° C the uptake of all three amines was greatly diminished. The presence of the antagonists cocaine, chlorpromazine, lysergic acid diethylamide, mepyramine and pronethalol (at 10−6 or 10−5 g/ml.) did not affect uptake of the amines.5. In the steady state the ratios of concentration of the amines between cells and medium were greater than could be accounted for by a Donnan distribution.6. Cells which had taken up amines lost most but not all of them into amine‐free medium, at rates which were slower than the corresponding rates of uptake. It was concluded that the amines are partially bound in the cells, noradrenaline most and histamine least.7. The slow diffusion of amines into, and the small amounts retained by, erythrocytes indicate that they do not contribute significantly to the rapid termination of the pharmacological actions of these amines in vivo.
The effects of changes in haematocrit on renal function
Authors: Nashat F. S. , Portal R. W. 
Published: December 2014

1. Acute changes in total body haematocrit were produced in anaesthetized dogs by the rapid infusion of packed red cells, dextran solution or hypertonic mannitol. A reduction of haematocrit resulted in a decrease in filtration fraction, and a rise of haematocrit in an increase in filtration fraction. A direct relationship between water reabsorption (relative to filtered load) and packed cell volume (
P.C.V.) was also observed.2. It is suggested that the changes in filtration fraction accompanying changes in haematocrit are mediated largely by a passive alteration of efferent arteriolar resistance resulting from modifications of blood viscosity.
Electrical potentials and ion concentrations across the gut of Cryptochiton stelleri
Authors: Lawrence A. L. , Mailman D. S. 
Published: December 2014

1. The electrical potential and concentration differences of Na, K, and Cl in the mucosal and serosal solutions of everted sacs of gut from Cryptochiton stelleri were determined.2. The parameters were used to determine if active ion transport was present in segments from the anterior and posterior intestine.3. The electrical potentials were of the order of 0·5 mV, serosa negative, in the anterior intestine, and 1 mV, serosa positive, in the posterior intestine. The potentials, although small, were significantly different from zero.4. The potentials of all segments responded to anoxia and incubation at different temperatures in a manner indicating that they were of active origin.5. Ions were accumulated against electrical potentials in some segments but did not respond to anoxia or incubation at different temperatures in a consistent fashion.6. It was concluded that active ion transport was present but no evidence for active transport of Na, K or Cl across the gut could be found.7. K leaked from the gut during incubation at non‐physiological temperatures or during hypoxia and was removed upon restoration of physiological conditions.
Auditory responses of neurones in the lateral mesencephalic nucleus (inferior colliculus) of the Barbary dove
Authors: Biederman-Thorson Marguerite 
Published: December 2014

1. Auditory responses have been recorded from forty‐five single neurones in the lateral mesencephalic nucleus of the dove, confirming the suspected auditory function of this nucleus.2. Most of the neurones with sustained responses to tones fell into three response‐categories: inhibitory only, excitatory in a central range of frequencies with inhibition in adjacent frequency regions, and predominantly inhibitory with one or more relatively small excitatory regions. Seven of the neurones studied showed only transient responses: these had high thresholds or were restricted to a narrow range of frequencies.3. Responses to clicks were sometimes obtained, but were variable in different units and in a single unit were often dependent on repetition rate.4. Many properties of these neurones are similar to those in the cat inferior colliculus. The most notable difference is the existence in the dove of neurones with exclusively or predominantly inhibitory responses.
CATCh, an Ensemble Classifier for Chimera Detection in 16S rRNA Sequencing Studies
Authors: Mysara Mohamed , Saeys Yvan , Leys Natalie , Raes Jeroen , Monsieurs Pieter 
Published: December 2014

ABSTRACT

In ecological studies, microbial diversity is nowadays mostly assessed via the detection of phylogenetic marker genes, such as 16S rRNA. However, PCR amplification of these marker genes produces a significant amount of artificial sequences, often referred to as chimeras. Different algorithms have been developed to remove these chimeras, but efforts to combine different methodologies are limited. Therefore, two machine learning classifiers (reference-based and
de novo
CATCh) were developed by integrating the output of existing chimera detection tools into a new, more powerful method. When comparing our classifiers with existing tools in either the reference-based or
de novo
mode, a higher performance of our ensemble method was observed on a wide range of sequencing data, including simulated, 454 pyrosequencing, and Illumina MiSeq data sets. Since our algorithm combines the advantages of different individual chimera detection tools, our approach produces more robust results when challenged with chimeric sequences having a low parent divergence, short length of the chimeric range, and various numbers of parents. Additionally, it could be shown that integrating CATCh in the preprocessing pipeline has a beneficial effect on the quality of the clustering in operational taxonomic units.
Multilocus Sequence Analysis of Xanthomonads Causing Bacterial Spot of Tomato and Pepper Plants Reveals Strains Generated by Recombination among Species and Recent Global Spread of Xanthomonas gardneri
Authors: Timilsina Sujan , Jibrin Mustafa O. , Potnis Neha , Minsavage Gerald V. , Kebede Misrak , Schwartz Allison , Bart Rebecca , Staskawicz Brian , Boyer Claudine , Vallad Gary E. , Pruvost Olivier , Jones Jeffrey B. , Goss Erica M. 
Published: December 2014

ABSTRACT

Four
Xanthomonas
species are known to cause bacterial spot of tomato and pepper, but the global distribution and genetic diversity of these species are not well understood. A collection of bacterial spot-causing strains from the Americas, Africa, Southeast Asia, and New Zealand were characterized for genetic diversity and phylogenetic relationships using multilocus sequence analysis of six housekeeping genes. By examining strains from different continents, we found unexpected phylogeographic patterns, including the global distribution of a single multilocus haplotype of
X. gardneri
, possible regional differentiation in
X. vesicatoria
, and high species diversity on tomato in Africa. In addition, we found evidence of multiple recombination events between
X. euvesicatoria
and
X. perforans.
Our results indicate that there have been shifts in the species composition of bacterial spot pathogen populations due to the global spread of dominant genotypes and that recombination between species has generated genetic diversity in these populations.
Functional Expression of Full-Length TrkA in the Prokaryotic Host Magnetospirillum magneticum AMB-1 by Using a Magnetosome Display System
Authors: Honda Toru , Yasuda Takayuki , Tanaka Tsuyoshi , Hagiwara Koji , Arai Tohru , Yoshino Tomoko 
Published: December 2014

ABSTRACT

Tropomyosin receptor kinase A (TrkA), a receptor tyrosine kinase, is known to be associated with various diseases. Thus, TrkA has become a major drug-screening target for these diseases. Despite the fact that the production of recombinant proteins by prokaryotic hosts has advantages, such as fast growth and ease of genetic engineering, the efficient production of functional receptor tyrosine kinase by prokaryotic hosts remains a major experimental challenge. Here, we report the functional expression of full-length TrkA on magnetosomes in
Magnetospirillum magneticum
AMB-1 by using a magnetosome display system. TrkA was fused with the magnetosome-localized protein Mms13 and expressed on magnetosome surfaces. Recombinant TrkA showed both nerve growth factor (NGF)-binding and autophosphorylation activities. TrkA expressed on magnetosomes has the potential to be used, not only for further functional analysis of TrkA, but also for ligand screening.
Hierarchy in Pentose Sugar Metabolism in Clostridium acetobutylicum
Authors: Aristilde Ludmilla , Lewis Ian A. , Park Junyoung O. , Rabinowitz Joshua D. 
Published: December 2014

ABSTRACT

Bacterial metabolism of polysaccharides from plant detritus into acids and solvents is an essential component of the terrestrial carbon cycle. Understanding the underlying metabolic pathways can also contribute to improved production of biofuels. Using a metabolomics approach involving liquid chromatography-mass spectrometry, we investigated the metabolism of mixtures of the cellulosic hexose sugar (glucose) and hemicellulosic pentose sugars (xylose and arabinose) in the anaerobic soil bacterium
Clostridium acetobutylicum
. Simultaneous feeding of stable isotope-labeled glucose and unlabeled xylose or arabinose revealed that, as expected, glucose was preferentially used as the carbon source. Assimilated pentose sugars accumulated in pentose phosphate pathway (PPP) intermediates with minimal flux into glycolysis. Simultaneous feeding of xylose and arabinose revealed an unexpected hierarchy among the pentose sugars, with arabinose utilized preferentially over xylose. The phosphoketolase pathway (PKP) provides an alternative route of pentose catabolism in
C. acetobutylicum
that directly converts xylulose-5-phosphate into acetyl-phosphate and glyceraldehyde-3-phosphate, bypassing most of the PPP. When feeding the mixture of pentose sugars, the labeling patterns of lower glycolytic intermediates indicated more flux through the PKP than through the PPP and upper glycolysis, and this was confirmed by quantitative flux modeling. Consistent with direct acetyl-phosphate production from the PKP, growth on the pentose mixture resulted in enhanced acetate excretion. Taken collectively, these findings reveal two hierarchies in clostridial pentose metabolism: xylose is subordinate to arabinose, and the PPP is used less than the PKP.