bluuebunny/crossref_metadata_2025 huggingface dataset:
A FRACTAL ANALYSIS OF PERMEABILITY FOR POWER-LAW FLUIDS IN POROUS MEDIA
Authors: ZHANG BIN , YU BOMING , WANG HAIXIA , YUN MEIJUAN
Published: October 2006

A fractal analysis of permeability for power-law fluids in porous media is presented based on the fractal characters of pore size distributions and tortuous flow paths/streamlines in the media. The proposed permeability model for power-law fluids in porous media is expressed as a function of the fractal dimensions of pore size distributions and tortuous flow paths/streamlines, porosity and microstructural parameters, as well as power exponent, and there is no empirical constant in the proposed model and every parameter in the model has clear physical meaning. The results predicted by the present fractal permeability model show that the model predictions (as the power exponent is 1) are in agreement with the available experimental data, and the predicted permeabilities (as the power exponent is not equal to 1) increase with the power exponent, which is also consistent with the physical situation.
Dissociation of Dorsal Root Ganglion Neurons Induces Hyperexcitability That Is Maintained by Increased Responsiveness to cAMP and cGMP
Authors: Zheng Ji-Hong , Walters Edgar T. , Song Xue-Jun
Published: October 2006

Injury or inflammation affecting sensory neurons in dorsal root ganglia (DRG) causes hyperexcitability of DRG neurons that can lead to spontaneous firing and neuropathic pain. Recent results indicate that after chronic compression of DRG (CCD treatment), both hyperexcitability of neurons in intact DRG and behaviorally expressed hyperalgesia are maintained by concurrent activity in cAMP-protein kinase A (PKA) and cGMP-protein kinase G (PKG) signaling pathways. We report here that when tested under identical conditions, dissociation produces a pattern of hyperexcitability in small DRG neurons similar to that produced by CCD treatment, manifest as decreased action potential (AP) current threshold, increased AP duration, increased repetitive firing to depolarizing pulses, increased spontaneous firing and resting depolarization. A novel feature of this hyperexcitability is its early expression—as soon as testing can be conducted after dissociation (∼2 h). Both forms of injury increase the electrophysiological responsiveness of the neurons to activation of cAMP-PKA and cGMP-PKG pathways as indicated by enhancement of hyperexcitability by agonists of these pathways in dissociated or CCD-treated neurons but not in control neurons. Although inflammatory signals are known to activate cAMP-PKA pathways, dissociation-induced hyperexcitability is unlikely to be triggered by signals released from inflammatory cells recruited to the DRG because of insufficient time for recruitment during the dissociation procedure. Inhibition by specific antagonists indicates that continuing activation of cAMP-PKA and cGMP-PKG pathways is required to maintain hyperexcitability after dissociation. The reduction of hyperexcitability by blockers of adenylyl cyclase and soluble guanylyl cyclase after dissociation suggests a continuing release of autocrine and/or paracrine factors from dissociated neurons and/or satellite cells, which activate both cyclases and help to maintain acute, injury-induced hyperexcitability of DRG neurons.
Firing Patterns of Human Genioglossus Motor Units During Voluntary Tongue Movement
Authors: Bailey E. Fiona , Rice Amber D. , Fuglevand Andrew J.
Published: October 2006

The tongue participates in a range of complex oromotor behaviors, including mastication, swallowing, respiration, and speech. Previous electromyographic studies of the human tongue have focused on respiratory-related tongue muscle activities and their role in maintaining upper airway patency. Remarkably, the activities of human hypoglossal motor units have not been studied during the execution of voluntary maneuvers. We recorded single motor unit activity using tungsten microelectrodes in the genioglossus muscle of 10 healthy human subjects performing both slow tongue protrusions and a static holding maneuver. Displacement of the tongue was detected by an isotonic transducer coupled to the lingual surface through a customized lever arm. For protrusion trials, the firing rate at recruitment was 13.1 ± 3 Hz and increased steeply to an average of 24 ± 6 Hz, often with very modest increases in tongue protrusion. For the static holding task, the average firing rate was 16.1 ± 4 Hz, which is surprisingly high relative to limb motor units. The average coefficient of variation of interspike intervals was ∼20% (range, 10–28%). These are the first recordings of their type obtained in human subjects and provide an initial glimpse into the voluntary control of hypoglossal motoneurons during tongue movements presumably instigated by activity in the motor cortex.
Effect of G-Force on Bicuspid Aortic Valve in Aviators
Authors: Carter Dan , Pokroy Russell , Azaria Bella , Matetzky Shlomi , Prokopetz Alex , Barenboim Erez , Harpaz David , Goldstein Liav
Published: October 2006

Background and Aims: Bicuspid aortic valve (BAV) is a common congenital cardiac malformation. The major complications are aortic stenosis (AS), aortic regurgitation (AR), infectious endocarditis and aortic dissection. This paper aims to assess the hemodynamic importance of incidentally-found BAV in military aviators and evaluate the effect of high G-force on disease progression. Methods: Aviators with BAV were detected by reviewing all cardiac assessment records between 1987 and 2005. All aviators underwent annual flight surgeon examination. Echocardiography was performed as recommended by our cardiologists and flight surgeons. Results: Eight newly diagnosed cases of BAV were found. All of the aviators continued active aviation throughout the study period. Repeat echocardiography demonstrated progressive widening of the aortic diameter in five of the eight aviators. No worsening of valve dysfunction was seen in those with mild aortic regurgitation at diagnosis. Left ventricular dimensions and function did not deteriorate. No new valve complications, including infectious endocarditis, were seen. The age at diagnosis strongly correlated with the root diameter change; both total (r = 0.74, p = 0.02) and annualized (r = 0.78, p = 0.02) change. Over a mean follow-up period of 12.1 years, no difference was seen in the progression of BAV in high-performance as compared to low-performance aviators. Conclusions: Exposure to G-force and anti-G maneuvers does not appear to worsen cardiac and valve function in aviators with BAV.
Monitoring Treatment Integrity
Authors: Wilkinson Lee A.
Published: October 2006

An international trend in school psychology services is a shift from an emphasis on assessment-based activities to a paradigm of consultation problem-solving and behavioural intervention. As the profession experiences an expansion of roles and functions, school psychologists should have an understanding of a critical aspect of behaviour change: treatment integrity (Gresham, 1989). Treatment integrity (or fidelity) refers to the extent to which an intervention is implemented as intended (or planned). This article describes the construct of treatment integrity as it relates to the implementation of consultation-derived behaviour intervention plans. Practical approaches for assessing and monitoring the integrity of treatments are presented. A treatment-monitoring interview (TMI) is proposed as an initial step towards developing a technology to assess and facilitate treatment integrity in school-based behavioural consultation practice. Limitations, implications for practice and future research directions are discussed.
Urea stimulation of KCl cotransport induces abnormal volume reduction in sickle reticulocytes
Authors: Joiner Clinton H. , Kirk Rettig R. , Jiang Maorong , Risinger Mary , Franco Robert S.
Published: October 2006

KCl cotransport (KCC) activity contributes to pathologic dehydration in sickle (SS) red blood cells (RBCs). KCC activation by urea was measured in SS and normal (AA) RBCs as Cl-dependent Rb influx. KCC-mediated volume reduction was assessed by measuring reticulocyte cellular hemoglobin concentration (CHC) cytometrically. Urea activated KCC fluxes in fresh RBCs to levels seen in swollen cells, although SS RBCs required lower urea concentrations than did normal (AA) RBCs. Little additional KCC stimulation by urea occurred in swollen AA or SS RBCs. The pH dependence of KCC in “euvolemic” SS RBCs treated with urea was similar to that in swollen cells. Urea triggered volume reduction in SS and AA reticulocytes, establishing a higher CHC. Volume reduction was Cl dependent and was limited by the KCC inhibitor, dihydro-indenyl-oxyalkanoic acid. Final CHC depended on urea concentration, but not on initial CHC. Under all activation conditions, volume reduction was exaggerated in SS reticulocytes and produced higher CHCs than in AA reticulocytes. The sulfhydryl-reducing agent, dithiothreitol, normalized the sensitivity of KCC activation to urea in SS RBCs and mitigated the urea-stimulated volume decrease in SS reticulocytes, suggesting that the dysfunctional activity of KCC in SS RBCs was due in part to reversible sulfhydryl oxidation.
Human rhinovirus induces robust IP-10 release by monocytic cells, which is independent of viral replication but linked to type I interferon receptor ligation and STAT1 activation
Authors: Korpi-Steiner Nichole L , Bates Mary Ellen , Lee Wai-Ming , Hall David J , Bertics Paul J
Published: October 2006

Human rhinovirus (HRV)-induced respiratory infections are associated with elevated levels of IFN-γ-inducible protein 10 (IP-10), which is an enhancer of T lymphocyte chemotaxis and correlates with symptom severity and T lymphocyte number. Increased IP-10 expression is exhibited by airway epithelial cells following ex vivo HRV challenge and requires intracellular viral replication; however, there are conflicting reports regarding the necessity of type I IFN receptor ligation for IP-10 expression. Furthermore, the involvement of resident airway immune cells, predominantly bronchoalveolar macrophages, in contributing to HRV-stimulated IP-10 elaboration remains unclear. In this regard, our findings demonstrate that ex vivo exposure of human peripheral blood monocytes and bronchoalveolar macrophages (monocytic cells) to native or replication-defective HRV serotype 16 (HRV16) resulted in similarly robust levels of IP-10 release, which occurred in a time- and dose-dependent manner. Furthermore, HRV16 induced a significant increase in type I IFN (IFN-α) release and STAT1 phosphorylation in monocytes. Neutralization of the type I IFN receptor and inhibition of JAK or p38 kinase activity strongly attenuated HRV16-stimulated STAT1 phosphorylation and IP-10 release. Thus, this work supports a model, wherein HRV16-induced IP-10 release by monocytic cells is modulated via autocrine/paracrine action of type I IFNs and subsequent JAK/STAT pathway activity. Our findings demonstrating robust activation of monocytic cells in response to native and/or replication-defective HRV16 challenge represent the first evidence indicating a mechanistic disparity in the activation of macrophages when compared with epithelial cells and suggest that macrophages likely contribute to cytokine elaboration following HRV challenge in vivo.
Myocardin is a direct transcriptional target of Mef2, Tead and Foxo proteins during cardiovascular development
Authors: Creemers Esther E. , Sutherland Lillian B. , McAnally John , Richardson James A. , Olson Eric N.
Published: October 2006

Myocardin is a transcriptional co-activator of serum response factor (Srf),which is a key regulator of the expression of smooth and cardiac muscle genes. Consistent with its role in regulating cardiovascular development, myocardin is the earliest known marker specific to both the cardiac and smooth muscle lineages during embryogenesis. To understand how the expression of this early transcriptional regulator is initiated and maintained, we scanned 90 kb of genomic DNA encompassing the myocardin gene for cis-regulatory elements capable of directing myocardin transcription in cardiac and smooth muscle lineages in vivo. Here, we describe an enhancer that controls cardiovascular expression of the mouse myocardin gene during mouse embryogenesis and adulthood. Activity of this enhancer in the heart and vascular system requires the combined actions of the Mef2 and Foxo transcription factors. In addition,the Tead transcription factor is required specifically for enhancer activation in neural-crest-derived smooth muscle cells and dorsal aorta. Notably,myocardin also regulates its own enhancer, but in contrast to the majority of myocardin target genes, which are dependent on Srf, myocardin acts through Mef2 to control its enhancer. These findings reveal an Srf-independent mechanism for smooth and cardiac muscle-restricted transcription and provide insight into the regulatory mechanisms responsible for establishing the smooth and cardiac muscle phenotypes during development.
Effects of oleic acid on the high threshold barium current in seabassDicentrarchus labraxventricular myocytes
Authors: Chatelier A. , Imbert N. , Infante J. L. Zambonino , McKenzie D. J. , Bois P.
Published: October 2006

The present study employed a patch clamp technique in isolated seabass ventricular myocytes to investigate the hypothesis that oleic acid (OA), a mono-unsaturated fatty acid, can exert direct effects upon whole-cell barium currents. Acute application of free OA caused a dose-dependent depression of the whole-cell barium current that was evoked by a voltage step to 0 mV from a holding potential of –80 mV. The derived 50% inhibitory concentration(IC50) was 12.49±0.27 μmol l–1. At a concentration of 30 μmol l–1, OA significantly reduced the current density to about 45% of control values, but did not modify either the shape of the current-density voltage relationship or the apparent reversal potential. In addition, OA did not modify the voltage dependence of either steady state inactivation or activation curves. Taken together, these results indicate that physiological concentrations of free OA decrease the conductance of the L-type inward current, without altering its properties of selectivity and its voltage dependence. The inhibitory effect of OA upon the L-type calcium channel may translate, in vivo, into a protective effect against arrhythmias induced by Ca2+ overload.
The control of anterior foregut motility during a larval molt of the moth Manduca sexta involves the modulation of presynaptic activity
Authors: Bestman Jennifer E. , Booker Ronald
Published: October 2006

In the moth, Manduca sexta, anterior foregut motility is modulated during the larval–larval molts in order to control the timing of molting fluid (MF) ingestion. MF is the enzymatic mixture that destroys the outer cuticle so that it can be shed at the end of the molt. The onset of the larval–larval molt is characterized by a dramatic decline in the amplitude of the anterior foregut contractions so that MF is not prematurely ingested. As the end of the molt approaches, the robust contractions of the anterior foregut return and the MF is ingested, enabling the larva to free itself from its old cuticle. In the present study we examine possible mechanisms involved in modulating anterior foregut motility during a larval–larval molt. Our results reveal that the release of a blood-borne factor plays a role in the decline in anterior foregut peristaltic activity during the molt. This blood-borne factor reduces the efficacy of the presynaptic endings of the motorneurons, resulting in a reduction in the amplitude of the excitatory junctional potential (EJP) recorded from the anterior foregut musculature. We also present evidence that crustacean cardioactive peptide (CCAP) targets the motorneuron terminals and its actions are sufficient to trigger the dramatic increase in EJP amplitude and anterior foregut contractions. Finally, the surgical ablation of the subesophageal ganglion, which has been previously described to be a source of CCAP neurons and the CCAP projections to the anterior foregut region, blocks both the increase in anterior foregut motility and the ingestion of MF that normally occur at the end of a larval–larval molt.
Vocal cord paralysis — 1979: Etiology and management
Authors: Tucker Harvey M.
Published: October 2006

Because of the development of reinnervation surgery, approximately 400 patients have been seen by the author with a referral diagnosis of vocal cord paralysis. Because these patients were being entered into a research protocol to evaluate the efficacy of reinnervation surgery, very careful evaluation and records have been kept. Retrospective analysis of these records has permitted an up‐to‐date evaluation of the epidemiology, natural history, symptoms, signs and presenting complaints, as well as the status of treatment of vocal cord paralysis at the present time. Since this subject has received only limited treatment in the recent literature, it was felt that such an opportunity to evaluate a large personal experience might be a worthwhile addition to current knowledge of the subject.
Patterns of involvement of the temporal bone in metastatic and systemic malignancy
Authors: Berlinger Norman T. , Koutroupas Steven , Adams George , Maisel Robert
Published: October 2006

The temporal bone appears to be involved with secondary malignant processes in discrete histologic patterns with rather characteristic clinical presentations. Five distinct types of involvement can be recognized: isolated metastasis from a distant primary tumor; direct extension from a regional primary tumor; meningeal carcinomatosis; leptomenin‐geal extension from an intracranial primary tumor; and leukemic or lymphomatous infiltration. The typical histopathological patterns are described with correlative clinical symtomatolgy. Differential diagnosis is considered, and guidelines for surgical management are discussed.
Facial nerve nucleus in the cat. Further study
Authors: Radpour Shokri , Gacek Richard R.
Published: October 2006

The location of efferent neurons, supplying muscles innervated by facial nerve, was studied in the brain stem of the cat using horseradish peroxidase. One to four microliters of HRP was injected in the frontalis, posterior belly of digastric, platysma, and auricularis superior muscles of the kittens. Their representative locations were determined in the facial nucleus.

No direct relation between the amount of HRP injected and the number of labeled neurons was found. The number of positive cells was between 2 and 661. No labeled neurons were found in nucleus of Vth or any other brain stem nuclei.
Blunt laryngeal trauma in children
Authors: Myer Charles M. , Orobello Peter , Cotton Robin T. , Bratcher Glenn O.
Published: October 2006

The diagnosis of laryngeal trauma in an adult trauma patient is usually readily made. It is frequently overlooked in children, however, because of the severity of their concomitant injuries and the unfamiliarity of pediatricians with this type of injury. The child with laryngeal trauma may develop respiratory distress much more quickly than an adult because of the relatively small dimensions of the pediatric airway and the apparent propensity for children to develop edema of the soft tissues of the larynx.

This report retrospectively reviews our experience during the past several years with ten children who experienced blunt laryngeal trauma. Emphasis is placed upon the diverse etiologies of laryngeal trauma in children and the importance of both flexible and rigid laryngoscopy in the diagnosis and management of these patients.
Delayed neck infection following anterior spine surgery
Authors: Kuriloff Daniel B. , Blaugrund Stanley , Ryan John , O'Leary Patrick
Published: October 2006

Pharyngoesophageal perforation and neck abscess formation is a rare complication of anterior cervical spine surgery. This complication usually manifests itself within the early postoperative period and is associated with soft tissue trauma at the time of surgery.

We describe two cases of retropharyngeal abscesses and persistent pharyngocutaneous fistulae which occurred in a delayed fashion several months after cervical spine surgery. The etiology, diagnosis, and treatment of this problem is discussed with a review of the current literature.
Detection and quantification of laryngotracheopulmonary aspiration with scintigraphy
Authors: Muz Jaroslaw , Mathog Robert H. , Miller Peter R. , Rosen Robert , Borrero George
Published: October 2006

Aspiration is analyzed by a new scintigraphic technique and standard videofluoroscopy in 78 patients with head and neck pathology and neurologic disorders. When both methods are compared to clinical aspiration and a positive x‐ray film of pneumonia, they appear to complement each other and provide a very accurate evaluation. Scintigraphy is a more sensitive method for detecting aspiration below the vocal cords and also provides for flow dynamics and a method of quantifying the amount of aspirated material. Videofluoroscopy shows more clearly the mechanism of the swallowing disorder and how the bolus enters the tracheobronchial tree. Studies in patients following head and neck surgery demonstrate a high incidence of dysphagia, aspiration, and pneumonia.
The Reconstitution of Political Catalanism 193975
Authors: Dowling Andrew
Published: October 2006

This article's aim is to analyse the transformations in political Catalanism that took place during the Franco dictatorship (193975). The two pre-Civil War forces of Catalanism, Esquerra Republicana de Catalunya and the Lliga Regionalista, lost their hegemony during the course of the
dictatorship. At the regime's end, new forces emerged in Catalonia and, in the terrain of nationalism, Convergncia i Uni became representative of the changes in Catalan political culture that occurred under Franco. By looking closely at the Catalan nationalist opposition to Franco, we will
see how this transformation came about.
From Algiers to Buenos Aires: The Third World Cinema Committee (197374)
Authors: Mestman Mariano
Published: October 2006

The cinema made in the Third World shows a great diversity depending on the region or country in question. But towards the late 1960s, there was a gradual consolidation of a cinematic-political project whose main principles were very similar to the Third Cinema proposed by Solanas and Getino, or to Garca Espinosa's imperfect cinema, but also included claims in other Asian or African manifestos. Particularly bold and ambitious was the creation of a Third World Cinema Committee intending to gather film-makers from the three continents. Two successive meetings, in Algiers (December 1973) and Buenos Aires (May 1974), gave rise to this organisational structure and established its goals. But whereas the Algiers meeting is a reference point in historiography on Third World Cinema, the Buenos Aires gathering remains almost unknown. This article reconstructs both events, the links that made them possible, and views the third-worldism of that period as a gap-bridging imaginary to the consolidation of Third World Cinema in the geopolitics of international cinema.
Substituted 3‐Hydroxypyrroles from 1‐Azapenta‐1,4‐dien‐3‐ones:The Aza‐Nazarov Reaction – Synthesis and Quantum Chemical Calculations
Authors: Dieker Jürgen , Fröhlich Roland , Würthwein Ernst‐Ulrich
Published: October 2006

On the basis of quantum chemical calculations, 1‐azapenta‐1,4‐dien‐3‐ones were chosen as candidates for a thorough theoretical and experimental investigation of their electrocyclization reactivity upon protonation. According to G3 theory, the O‐protonated 1‐azapenta‐1,4‐dien‐3‐one cyclizes with high exothermicity and modest activation barrier to give the corresponding 3‐hydroxydihydropyrrolium ion (“aza‐Nazarov reaction”), whereas the corresponding O‐protonated 2‐azapenta‐1,4‐dien‐3‐one shows endothermicity and a huge barrier to the electrocyclization reaction. The stereochemistry of the cyclization reaction (torquoselectivity) was studied in detail theoretically as well as the cyclization properties of vinylogous system 4, which may give either five‐ or seven‐membered heterocyclic cations (5 versus 6). 1‐Amino‐ and 1‐alkoxy‐1‐azapenta‐1,4‐dien‐3‐ones 9 and 10 wereeasily prepared from corresponding α‐imino‐carbonyl compounds 7 and 8 by aldol condensation. Experimentally, as evidenced by in situ NMR experiments, 1‐azapenta‐1,4‐dien‐3‐ones gave dihydropyrrole cations upon protonation at a low temperature. For preparative purposes, trapping of the 3‐hydroxypyrrole intermediates with the use of anhydrides proved to be advantageous. Thus, a large variety of new, fully substituted 3‐hydroxypyrrole derivatives 13–17 have become accessible in moderate‐to‐good yields, including two bis‐pyrrole compounds 17a,b. All new compounds were thoroughly characterized, including a number of X‐ray diffraction studies. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)
Amplification strategies in MR imaging: Activation and accumulation of sensing contrast agents (SCAs)
Authors: Querol Manuel , Bogdanov Alexei
Published: October 2006

We review new strategies for the development of Gd3+‐based T1‐relaxation agents and paramagnetic chemical exchange saturation transfer (PARACEST) “sensing” contrast agents (SCAs) designed specifically to detect small molecules or enzymatic activity in living systems. The first class of agents exhibits molecular “sensing” properties as a result of water coordination sphere effects, cleavage, or synthesis of reactive precursor compounds that recombine with macromolecules with the resultant formation of immobilized or rotationally constrained paramagnetic cations. This effect results in changes of water proton relaxation times. The second class (PARACEST) comprises a family of lanthanide‐based paramagnetic compounds suitable for CEST imaging. The need for both types of MR agents is justified by efforts to utilize magnetic resonance imaging (MRI) to visualize fine structures in living tissue, and to increase the molecular specificity of MRI. J. Magn. Reson. Imaging 2006. © 2006 Wiley‐Liss, Inc.
Channel bed evolution and sediment transport under declining sand inputs
Authors: Gran Karen B. , Montgomery David R. , Sutherland Diane G.
Published: October 2006

Coupled field and laboratory investigations explore links between bed surface structure development and sediment transport as sand inputs decline. On the Pasig‐Potrero River, we investigated channel recovery following emplacement of sand‐rich pyroclastic deposits in the 1991 eruption of Mount Pinatubo, Philippines. As sediment inputs declined from 1996 to 2003, surface grain size increased, clast structures formed, and sediment mobility and bed load transport rates declined. Our field results parallel those from flume experiments studying highly energetic channels with similar sand contents. As the feed mixture shifted from 70% to 40% sand, surface grain size and gravel interactions increased, forming clusters and armor patches. Bed reorganization into patches initially accommodated coarsening with minimal effect on bed load transport rates, roughness, or friction angle within sandy transport zones. As sand declined further, gravel jams interrupted the connectivity of sandy transport zones, lowering transport rates. Patch development lowered the threshold for the transition from sand‐dominated to gravel‐dominated transport, focusing this transition over a narrow range of sand content.
Multilayer mirror monochromatic self-emission x-ray imaging on the Z accelerator
Authors: Jones B. , Deeney C. , Coverdale C. A. , Meyer C. J. , LePell P. D.
Published: October 2006

A time-resolved, monochromatic soft x-ray diagnostic has been developed for self-emission imaging of imploding z pinches on the Z accelerator [R. B. Spielman et al., Phys. Plasmas 5, 2105 (1998)] at Sandia National Laboratories. Multiple pinhole images are reflected from a planar multilayer mirror with narrow photon energy bandwidth (<10eV) onto a 1ns gated microchannel plate detector. High-energy bremsstrahlung x rays are not reflected, providing improved signal to noise in comparison to a standard filtered pinhole camera included in the same beamline of the instrument. An example of data from the existing ∼277eV imaging system is presented, showing cooler imploding mass extending to larger radius than the on-axis K-shell emission of an aluminum wire array. Multilayer mirror and filter pair configurations ranging from 96to769eV are discussed.
Rectifying and magnetotransport properties of the heterojunction of Co-doped and undoped TiO2−δ with La0.69Ca0.31MnO3 single crystal
Authors: Xiong C. M. , Zhao Y. G. , Zhao Z. H. , Kou Z. Q. , Cheng Z. H. , Tian H. F. , Yang H. X. , Li J. Q.
Published: October 2006

Electron-doped wide-band-gap dilute magnetic semiconductor Ti0.93Co0.07O2−δ and TiO2−δ were grown on a hole-doped La0.69Ca0.31MnO3 single crystal to form heterojunctions. These junctions exhibit good rectifying properties and magnetoresistance effect over a relatively wide temperature range. The results for TiO2−δ were similar to that of Ti0.93Co0.07O2−δ in all respects. A schematic band structure of the junction was proposed to account for the results. This work indicates that manganite single crystals can be used as substrates for integration with other materials, which may open an alternative avenue for the exploitation of the manganite-based devices.
Formal adjoints and a canonical form for linear operators
Authors: Eastwood Michael , Gover A.
Published: October 2006

We describe a canonical form for linear differential operators that are formally self-adjoint or formally skew-adjoint.
Reference ranges of skin micro‐relief according to age in French Caucasian and Japanese women
Authors: Guinot C. , Latreille J. , Mauger E. , Ambroisine L. , Gardinier S. , Zahouani H. , Guéhenneux S. , Tschachler E.
Published: October 2006

Background/purpose: The variation of skin surface morphological indicators according to age has not been frequently studied. The aim of this work was to establish French Caucasian and Japanese reference ranges of these indicators according to age.

Methods: Two studies were performed simultaneously in Paris and Sendai on 356 Caucasian and 120 Japanese healthy women aged from 20 to 80 years. Skin replicas were obtained from the volar forearm and analysed by interferometry. This analysis yielded 16 morphological indicators. Reference ranges according to age were established using the statistical methodology defined by Royston.

Results/discussion: Reference ranges were found for 15 out of the 16 parameters for the French women as well as for the Japanese women. The models' truthfulness will have to be confirmed using new samples, larger if possible. Moreover, non‐parametric methods will be used in order to compare the results provided by these approaches.
Protective Effects of Endotoxin in a Rat Model of Chronic Inflammation are Accompanied By Suppressed Secretion of Pro‐Inflammatory Cytokines and Biphasic Alteration in Hypothalamo‐Pituitary‐Adrenal Axis Activity
Authors: Richards L. J. , Chover‐Gonzalez A. , Harbuz M. S. , Jessop D. S.
Published: October 2006

We have previously demonstrated that Gram‐negative bacterial endotoxin can exert long‐term protective effects against the chronic inflammatory disease adjuvant arthritis in rats. The present study was designed to investigate the mechanisms and time‐course of hypothalamo‐pituitary‐adrenocortical (HPA) axis activity and cytokine secretion underlying this phenomenon. Rats were injected with endotoxin (lipopolysaccharide) and blood was collected either 7 or 21 days later. Priming with endotoxin induced a biphasic alteration in secretion of adrenocorticotrophic hormone and corticosterone in response to a second injection of endotoxin, with decreased secretion observed after 7 days whereas robust secretion was observed at 21 days. Seven days following priming with endotoxin, plasma concentrations of pro‐inflammatory cytokines interleukin (IL)‐6 and interferon (IFN)‐γ were reduced by 90%, and tumour necrosis factor (TNF)‐α by 70%, compared to saline‐treated rats, whereas robust secretion of the anti‐inflammatory cytokine IL‐10 was maintained in both groups. A similar net change favouring an anti‐inflammatory cytokine secretory milieu was also observed 21 days following priming with endotoxin. This study provides evidence that the long‐term protective effects of endotoxin on inflammation are associated with a sustained reduction in secretion of pro‐inflammatory cytokines. HPA axis hypoactivity at 7 days suggests that corticosterone is not involved in suppressing IL‐6, IFN‐γ and TNF‐α at this time point. Conversely, hypersecretion of corticosterone at 21 days may underlie synchronous suppression of IL‐6 and IFN‐γ. These data provide novel insight into interactions between HPA axis activity and cytokine secretion following endotoxin priming prior to induction of inflammatory disease.
OCCURRENCE OF STEROL ESTERS IN THE CHICKEN BRAIN DURING PRENATAL AND POSTNATAL DEVELOPMENT
Authors: Grafnetter D. , Grossi E. , Morganti P.
Published: October 2006

The changes in brain constituents during development have been widely studied and data concerning lipids and other substances are now available. Some investigators have considered the possibility of correlating the maturation of the brain with the deposition of specific lipid fractions; but it is difficult to relate composition data to the functional development of the nervous system.

An increase in the concentration of various lipids in the brain of different animal species during development has been demonstrated by many investigators, and these data have recently been reviewed by Sperry (1963). The concentration of cholesterol increases sharply during brain development: Folch ‐Pi (1955) found an increase of the order of 300‐400 per cent in mouse brain from birth to 90 days, and Mandel and Bieth (1951) demonstrated a 300 per cent increase of cholesterol concentration during the development of the rat brain from newborn to adult age. Mandel, Bieth and Stoll (1949) demonstrated that the cholesterol content increases from 1 to 5‐4 mg in the brain of the chick embryo from the 10th to 19th day of incubation.

Most investigators agree that cholesterol is present in mature brain only in the free form (Cumings, 1957; Davison and Wajda, 1959) and Le Baron and Folch (1959) postulated that it is combined with the water soluble proteins in the myelin sheat. However, some investigators have found esterified cholesterol in developing brain. Mandelet al. (1949) found cholesterol esters in the brain of chick embryo and Adams and Davison (1959) in the cord of the chick embryo and in foetal human brain. JOHNSON, Mc Nabb and Rossiter (1948) and Brante (1949) found some esterified cholesterol in the infant human brain, while Cumings (1957) found trace amounts of cholesterol esters in adult white and infant grey matter. More recently Clarenburg, Chaikoff and Morris (1963) give values for cholesterol esters in the brain of the developing rabbit. However, there are no firm data on the changes in concentration of esterified cholesterol in the brain during development. We have, therefore, measured the sterol esters in the chick developing brain at different stages of embryonic and postnatal life.

Recent investigations have shown that cholesterol is not the only sterol present in the developing brain, but there is a considerable amount of desmosterol (24‐dehydro‐cholesterol) in the brain of the chick embryo (Fish, Boyd and Stokes, 1962) and other animal species (Paoletti, Fumagalli, Grossi and Paoletti; 1965). Desmosterol is partially esterified in the chick brain and disappears from the brain during maturation (Fumagalli, Grafnetter, Grossi and Morganti, 1963).
THE COMPOSITION OF THE MYELIN PROTEINS OF THE PERIPHERAL NERVOUS SYSTEM12
Authors: Wolfgram F. , Kotorii K.
Published: October 2006

Abstract— A method for the isolation of peripheral nerve myelin is described. Peripheral nerve myelin differs from centrum ovale myelin in its amino acid composition, in that it contains a greater proportion of protein that is digestible with trypsin and pepsin, and in the insolubility of its proteins in chloroform–methanol.
SERINE TRANSHYDROXYMETHYLASE IN DEVELOPING MOUSE BRAIN1
Authors: Bridgers W. F.
Published: October 2006

Abstract— Serine transhydroxymethylase in extracts from mouse brain declines in specific activity during the first 2 weeks of postnatal life. This decrease in potential for synthesis of methylene tetrahydrofolate from serine is most probably compatible with the declining postnatal rates of protein and nucleic acid synthesis.
HETEROGENEITY OF BRAIN FRACTIONS CONTAINING NEURONAL AND GLIAL CELLS1
Authors: Cremer J. E. , Johnston P. V. , Roots B. I. , Trevor A. J.
Published: October 2006

Abstract— A density‐gradient procedure, previously reported to enable the separation of intact metabolically active neuronal and glial cells, has been appraised in terms of cellular homogeneity and integrity.

Morphological examination by light and electron microscopy of fractions prepared by this method demonstrated marked heterogeneity and a high degree of cellular damage. The ‘neuronally enriched’ fraction contained a large proportion of non‐neuronal tissue including fragmented capillaries and endothelial cells. The ‘glial‐enriched’ fraction contained numerous nerve‐endings and synaptic boutons.

The distribution of protein, DNA, carbonic anhydrase, succinate dehydrogenase and lactate dehydrogenase was examined, but such data were difficult to interpret in view of the marked heterogeneity of the fractions. Particulate material from the fractions was capable of endogenous respiration which was stimulated by glucose or pyruvate to levels slightly lower than that found in slices of cerebral cortex.

The limitations of this and other methods for separation of cell types from neural tissue are discussed.
INCORPORATION OF [14C]GLYCINE INTO PROTEIN OF THE ADULT RAT PERIPHERAL NERVE: EFFECTS OF INHIBITORS
Authors: Matheson D. F.
Published: October 2006

—(1) The rate of incorporation in vitro of [14C]glycine into adult rat peripheral nerve protein was studied and found to be linear up to a concentration of 4.5 μc/ml. It was also linear with time of incubation up to at least 6 hr.

(2) Anaerobiosis, potassium cyanide, dinitrophenol and diphtheria toxin inhibited the incorporation of [14C]glycine into protein, in a manner comparable to other tissues.
CHANGES IN ACETYLCHOLINE, NOREPINEPHRINE AND 5‐HYDROXYTRYPTAMINE CONCENTRATIONS IN SEVERAL DISCRETE BRAIN AREAS OF THE RAT DURING BEHAVIOURAL EXCITATION1,2
Authors: Aprison M. H. , Kariya T. , Hingtgen J. N. , Toru M.
Published: October 2006

—Acetylcholine, 5‐hydroxytryptamine, and norepinephrine concentrations were measured in the telencephalon, diencephalon plus mesencephalon (midbrain), and pons‐medulla oblongata of rats exhibiting behavioral excitation while working on a Sidman avoidance schedule and injected with 50 mg/kg iproniazid 16 hr before being given 2 mg/kg tetrabenazine. Acetylcholine concentrations in all three brain areas decreased and returned to normal levels at different times. The time course of increased response rates correlated best with the acetylcholine levels in the telencephalon. Both the 5‐hydroxytryptamine and norepinephrine concentrations remained similar to the iproniazid control values during the period of behavioural excitation. However, the norepinephrine concentration in the midbrain showed a continuous decreasing trend toward naive control levels. These data suggest that changes in a cholinergic system in the telencephalon and a noradrenergic system in the midbrain operate in the maintenance of behavioural excitation.
RATE OF PROTEIN RENEWAL IN SPINAL MOTONEURONS OF ADOLESCENT AND OLD RATS
Authors: Jakoubek B. , Gutmann E. , Fischer J. , Babický A.
Published: October 2006

Abstract—

The rate of incorporation of [35S]methionine and the turnover rate of proteins in spinal motoneurons were studied in adolescent and old rats. The radioactivity of proteins was estimated by quantitative autoradiography and direct counting of beta radiation from samples of neurons isolated by free hand dissection. Both methods showed that the rate of incorporation into spinal motoneurons was significantly lower in old animals. By measuring the turnover rate of proteins in spinal motoneurons at least two protein components could be distinguished by their different turnover rates. The short‐lived component had an average half‐life of 2‐2‐2‐8 days, the long‐lived protein component had an average half‐life of 27‐38 days. Neither in the short‐lived component, nor in the long‐lived component was it possible to detect a significant difference between adolescent and old rats.
MYELIN TYPES WITH DIFFERENT PROTEIN COMPONENTS IN THE SAME SPECIES1
Authors: Mehl E. , Wolfgram F.
Published: October 2006

Abstract— Myelin was isolated from bovine optic nerve, cerebral white matter, spinal cord white matter and peripheral nerve (intradural spinal roots). The freeze‐dried myelin completely dissolved in phenol‐formic acid‐water (14:3:3, w/v/v), and acrylamide gel electrophoresis of the myelin proteins was performed with this solvent. Qualitative and quantitative differences were observed in the myelin proteins from the various regions of the CNS. Myelin of peripheral nerve contained proteins that are apparently unique to it and which are not found in the myelin of the CNS.
LOCALIZATION OF ARYLSULPHATASE IN NEURONS1
Authors: Hirsch Hilde E.
Published: October 2006

Abstract— Arylsulphatase activity, with 4‐methylumbelliferone sulphate as substrate, was measured by a quantitative histochemical method in individual anterior horn nerve cell bodies and adjacent neuropil of man and monkey; and in molecular and granular layers and subjacent white matter of cerebellum of monkey, rat and guinea pig. The activity was much higher in neuronal perikarya than in neuropil, and higher in the granular layer of cerebellum than in the molecular or white matter, thus resembling the distinctive distribution, reported in monkey, of three other lysosomal enzymes, β‐galactosidase, β‐glucuronidase and α‐naphthyl acid phosphatase. One exception was encountered: the white matter of guinea pig cerebellum had more arysulphatase activity than the granular layer. For comparison, other lysosomal enzymes also were measured in rat and guinea pig cerebellum; in these species, α‐naphthyl acid phosphatase distribution was found to differ from that of β‐galactosidase and arysulphatase, and from the pattern common to four lysosomal enzymes in the monkey.
BIOSYNTHESIS OF ASPARTIC, GLUTAMIC, γ‐AMINO‐BUTYRIC ACIDS AND GLUTAMINE IN BRAIN OF RATS DEPRIVED OF TOTAL SLEEP OR OF PARADOXICAL SLEEP
Authors: Mark J. , Godin Y. , Mandel P.
Published: October 2006

Abstract— The [14C]glucose incorporation rate into brain aspartate, glutamate, GABA and glutamine in rats deprived of total and paradoxical sleep was studied. The specific radioactivities of the isolated metabolites were related to the specific radioactivity of brain glucose. It was expected that the incorporation of radioactivity would reflect subtle changes occurring in brain amino acid metabolism during total and selective paradoxical sleep deprivation. The results show an increased specific radioactivity of glutamine in total sleep‐deprived rats. The variation in specific radioactivity of glutamine without a change in its concentration indicates an increased turnover of this compound. The reasons and possible mechanism for the change in glutamine specific radioactivity are discussed.
SOME PROPERTIES OF ISOLATED NEURONAL CELL FRACTIONS
Authors: Rose S. P. R. , Sinha A. K.
Published: October 2006

Abstract— 1. Histochemical evidence was presented illustrative of the composition of neuronal and neuropil (‘glial’) fractions isolated according to a previously published procedure. The neuropil refers to all cortical tissue other than neuronal perikarya.

2. On the basis of cell counts and of DNA content, an average cell mass of 100‐110 pg was calculated for cells in the neuronal fraction. Eight per cent of the total DNA was recovered in the neuronal fraction.

3. Both fractions synthesized ATP in vitro. Concentrations after 60 min incubation with glucose were: neuropil, 7–36 μmoles/mg protein; neuronal, 12–31 μmoles/mg protein.

4. Osmotic shock or homogenization resulted in changes in turbidity of the cell fractions which were interpreted as indicative of loss of cell structure. The free pool amino acids glutamate, glutamine, GABA, aspartate and alanine were retained in the precipitable material through several washes with isotonic solutions. Homogenization released 72 per cent of the neuronal and 68 per cent of the neuropil amino acids into the supernatant, but only 37 per cent and 19 per cent respectively of the protein.

5. By contrast with earlier reports, K+ accumulation has now been demonstrated in both neuronal and neuropil fractions. After incubation with glucose, K+ level were calculated as being 80 per cent of slice in the neuronal, and 65 per cent in the neuropil fraction. These results, and those of the osmotic shock experiments, were taken as indicative of the retention of some cell structure.

6. By comparison, cell fractions prepared by other procedures, using acetone‐glycerol‐water or tetraphenylboron for tissue disaggregation, produced preparations with limited metabolic capabilities; oxygen uptake, CO2 and lactate production were all lowered substantially.
METABOLISM OF GLUCOSE AND GLUTAMATE BY SYNAPTOSOMES FROM MAMMALIAN CEREBRAL CORTEX
Authors: Bradford H. F. , Thomas A. J.
Published: October 2006

—(1) Synaptosomes incubated in high sodium, low potassium media showed high linear respiration in the presence of glucose which was converted into lactate, aspartate, glutamate, glutamine, alanine and GABA during 1 hr incubation periods.

(2) Total conversion of glucose into most of these substrates over the incubation period was similar in synaptosomes and cortex slices. Half the lactate and only a small fraction of the glutamine made by slices was formed by synaptosomes.

(3) Pool sizes of amino acids in cortex slices after incubation with glucose were, in general, higher than in synaptosomes, glutamate and glutamine being four‐fold higher in slices.

(4) Most of the amino acids made from glucose by synaptosomes were contained within their structure and not lost to the medium.

(5) Glutamate was actively metabolized by synaptosomes to aspartate, glutamine, alanine and GABA. The specific radioactivities of the amino acids (except glutamine) after 1 hr incubation, approached that of the glutamate.

(6) Pyridoxal phosphate added to the incubation medium increased GABA production from glutamate but not from glucose.
LIPID COMPOSITION OF OPTIC NERVE MYELIN
Authors: MacBrinn Monica C. , O'Brien J. S.
Published: October 2006

Abstract— Myelin was isolated from bovine optic nerves by differential ultracentrifugation and its lipid composition was analysed. Optic nerve myelin contained 76·3 per cent lipid. The major lipids were cholesterol, ethanolamine glycerophosphatides (EGP) and cerebroside. Serine glycerophosphatides (SGP), sphingomyelin and cerebroside sulphate were present in smaller proportions. EGP and SGP contained 34·6 and 0·5 per cent aldehydes. The major fatty aldehydes were palmitaldehyde, stearaldehyde and octadecenaldehyde. The fatty acids of EGP, SGP and choline glycerophosphatides (CGP) were chiefly 16:0, 18:0 and 18:1, with small proportions of 20 and 22 carbon polyunsaturates. The sphingolipids contained predominantly saturated and monounsaturated fatty acids of chain lengths of 20–26 carbon atoms. Optic nerve myelin and white matter myelin resembled one another closely in overall lipid composition and in the fatty acid compositions of their constituent lipids. Optic nerve myelin and white matter myelin are chemically similar membranes, but both of these differ in their lipid composition from spinal root myelin.