Functional Duality Research Articles

Target-mass corrections and the Bloom-Gilman duality of the nucleon structure function

The occurrence of the Bloom-Gilman local duality in the low-order moments of the nucleon structure function is investigated for values of the squared four-momentum transfer Q 2 between ∼0.5 and 10 ( GeV/c) 2 . At variance with previous analyses truncated Cornwall-Norton moments, limited to the nucleon-resonance production regions, are considered. The role played by target-mass corrections is illustrated, showing that target-mass effects are necessary (but not sufficient) for producing the observed Bloom-Gilman duality of the nucleon structure function. The possibility of a local duality between the unphysical region at large values of the Nachtmann variable and the nucleon elastic peak contribution is analyzed. It is found that the proton magnetic form factor extracted assuming local duality is significantly below the experimental data at low and intermediate values of Q 2.

Cellules productrices de mucilages chez les plantes carnivores

This publication presents the structural and functional characteristics of mucigenic glands in some pitchers of carnivorous plants. They result from bibliography (Pinguicula, Drosera, Triphyophyllum, Drosophyllum) and also from original works (Utricularia). The glands anatomy and cytology were presented, showing polymorphism, according to the genus, the localization inner the pitcher and the kind of function. The cells which product abundant mucilage show a great number of dictyosomes and Golgi vesicles. In some examples, the glands can present a functional duality, with production of mucilages and also of enzymatic substances. The fine structures of these different celles were described, related with the physiological state of secretion.

Simulating Consciousness in a Bilateral Neural Network: “Nuclear” and “Fringe” Awareness

A technique for the bilateral activation of neural nets that leads to a functional asymmetry of two simulated “cerebral hemispheres” is described. The simulation is designed to perform object recognition, while exhibiting characteristics typical of human consciousness—specifically, the unitary nature of conscious attention, together with a dual awareness corresponding to the “nucleus” and “fringe” described by William James (1890). Sensory neural nets self-organize on the basis of five sensory features. The system is then taught arbitrary symbolic labels for a small number of similar stimuli. Finally, the trained network is exposed to nonverbal stimuli for object recognition, leading to Gaussian activation of the “sensory” maps—with a peak at the location most closely related to the features of the external stimulus. “Verbal” maps are activated most strongly at the labeled location that lies closest to the peak on homologous sensory maps. On the verbal maps activation is characterized by both excitatory and inhibitory Gaussians (a Mexican hat), the parameters of which are determined by the relative locations of the verbal labels. Mutual homotopic inhibition across the “corpus callosum” then produces functional cerebral asymmetries, i.e., complementary activation of homologous “association” and “frontal” maps within a common focus of attention—a nucleus in the left hemisphere and a fringe in the right hemisphere. An object is recognized as corresponding to a known label when the total activation of both hemispheres (nucleus plus fringe) is strongest for that label. The functional dualities of the cerebral hemispheres are discussed in light of the nucleus/fringe asymmetry.

Differing expression of MMPs-1 and -9 and urokinase receptor between diffuse- and intestinal-type gastric carcinoma.

Gastric cancer is classified into intestinal and diffuse types, which exhibit different biological behavior. Urokinase-type plasminogen activator (uPA), its receptor (uPAR) and matrix metalloproteinases (MMPs)-1 and -9 are considered to play important roles in cancer invasion and metastasis. We have already suggested a functional duality of these matrix-degrading enzymes/factors; they may also be involved in the matrix turnover (remodeling) or host immune/inflammatory reactions as far as they are expressed by host cells. We performed a retrospective study on the immuno-histochemical expression of these enzymes/factors in surgical specimens from patients with gastric cancer, including 26 with the diffuse and 78 with the intestinal type. We also evaluated macrophages since they are major sources of uPAR. The positivity rate for uPA in cancer cells was significantly lower in diffuse-type than in intestinal-type. Stromal expression was seen mainly along the invasive margin (tumor-host interface). The degree of stromal expression of uPAR and MMP-9 and the macrophage number were markedly decreased in diffuse-type compared with intestinal-type. Stromal expression of uPAR and macrophage number in intestinal-type were higher in patients without liver metastasis than in patients with liver metastasis, while uPA expression in cancer cells was more pronounced in patients with liver metastasis. Studies using frozen sections revealed that the expression of MMP-1, restricted to the stromal area, was more decreased in diffuse-type (18 patients) than in intestinal-type (21 patients). Our results show that the in situ expression of matrix-degrading enzymes/factors in gastric cancer is significantly more diminished in diffuse-type than in intestinal-type, suggesting a multifunctional aspect of the matrix-degradation process in cancer tissue.

Assessment of rectal mechanoreceptors in healthy humans by a reflexologic technique

Rectal distension studies have suggested the existence of 2 types of mechanoreceptors. Our aim was to confirm this functional duality by using a reflexologic technique, based on the recording of a nociceptive somatic reflex (the Rill reflex) which allows an objective evaluation of visceral sensitivity, during slow ramp or rapid phasic rectal distensions together with application of a local anesthetic. Methods: during a randomized double blind study, the effects of rectal distension on the amplitude of the Rill reflex recorded on the lower limb, were measured in 6 healthy volunteers after intrarectal application of 20 mL of local anesthetic, 2% lidocaine (L), or saline (S). Rectal distensions were performed with an electronic barostat on 4 days separated by a week. Each experimental day, one type of distension was performed with either L or S: rapid (900 mL/min) phasic distension (3 min duration) in a random order at 10, 20 and 30 mmHg, or slow (40 mL/min) ramp distension. The RIII reflex was continuously stimulated and the amplitude of the reflex response recorded before (control, 3 rain), during and after (3 min) each distension, and expressed as percentage of control values. Volumes, pressure and sensations were also measured. Results: (mean-+ SEM) : the RIII reflex threshold of detection was not modified by intrarectal application of L or S. During rapid distension, at 10 mmHg, the Rill response was not modified. At 20 mmHg, a facilitation of the reflex followed by a partial inhibition was obtained with S, and L abolished this inhibition (maximal inhibition : 64 _+_ 9% vs. 109 + 13%; P < 0.05). At 30 mmHg, an inhibition of the response was obtained with S that was partially abolished by L (maximal inhibition : 60 -+ 8% vs. 80 -+ 7%; P = NS). During S, slow ramp distension induced an inhibition of the RIII response that was completely abolished by L (maximal inhibition : 47-+ 8% vs. 100-+ 8%; P<0.05) and sensations during the distensions were significantly lower with L than with S (P < 0.05). Compliance curves were not different between L and S for any type of distensions. Conclusion: The inhibition of the RIll reflex corresponds to the classical phenomenon of counter-irritation triggered by heterotopic stimulation. Our results suggest that slow ramp distensions stimulate exclusively superficial (probably mucosai) mechanoreceptors whereas the effects of rapid distension are more complex as they probably stimulate both superficial and deeper (probably serosal) mechanoreceptors. This emphasizes the interest of the • refiexologic technique for neurophysiological study of gut sensations.

On the duality relation for correlation functions of the Potts model

We prove a recent conjecture on the duality relation for correlation functions of the Potts model for boundary spins of a planar lattice. Specifically, we deduce the explicit expression for the duality of the n-site correlation functions, and establish sum rule identities in the form of the M\"obius inversion of a partially ordered set. The strategy of the proof is by first formulating the problem for the more general chiral Potts model. The extension of our consideration to the many-component Potts models is also given.

Bridging a quantum-mechanical barrier [engineering education

Most engineers need a basic understanding of quantum mechanics, and for this the typical college introduction is enough. Such an introduction tends to be axiomatic but physically unenlightening. The rules of quantum mechanics (QM) are a fait accompli; justified because they work. This is a good beginning, but those needing to learn more face a special quantum barrier: more advanced texts often continue in the axiomatic tradition. Infinite-dimensional spaces, amplitude vectors, matrices, and operators in lieu of momentum and energy-these and other concepts may be introduced with little rationalization or intuition. To an inquiring student, QM can quickly become bizarre; something to be manipulated but not understood. This need not be so. Here the authors present one teaching solution. They show that many of QM's key ideas can be reasoned out from just a few physical assumptions with mathematics that is low in dimension, linear and accessible to many. Some results include a simple reason for believing probability amplitudes are more natural to use than probabilities, the duality of functions as vectors and vice versa, an example of how a matrix, an operator and a physical value might be related, the Heisenberg uncertainty principle and Schrodinger's equation.

Bloom-Gilman duality of inelastic structure functions in nucleon and nuclei

The Bloom-Gilman local duality of the inelastic structure function of the proton, the deuteron, and light complex nuclei is investigated using available experimental data in the squared four-momentum transfer range from $0.3$ to $5 (\mathrm{GeV}{/c)}^{2}$. The results of our analysis suggest that the onset of the Bloom-Gilman local duality is anticipated in complex nuclei with respect to the case of the proton and the deuteron. A possible interpretation of this result in terms of a rescaling effect is discussed with particular emphasis on the possibility of reproducing the damping of the nucleon-resonance transitions observed in recent electroproduction data off nuclei.

BiP, a Major Chaperone Protein of the Endoplasmic Reticulum Lumen, Plays a Direct and Important Role in the Storage of the Rapidly Exchanging Pool of Ca2+

The activity of BiP, the major chaperone of the endoplasmic reticulum (ER) lumen, is known to be Ca2+-regulated; however, the participation of this protein in the ER storage of the cation has not yet been investigated. Here such a role is demonstrated in human epithelial (HeLa) cells transiently transfected with the hamster BiP cDNA and incubated in Ca2+-free medium, as revealed by two different techniques. In the first, co-transfected aequorin was employed as a probe for assaying either the cytosolic of the mitochondrial free Ca2+ concentration. By this approach higher Ca2+ release responses were revealed in BiP-transfected cells by experiments in which extensive store depletion was induced either by repetitive stimulation with inositol 1,4,5-trisphosphate-generating agonists or by treatment with the Ca2+ ionophore, A23187. In the second technique the cells were loaded at the equilibrium with 45Ca, and the release of the tracer observed upon treatment with thapsigargin, a blocker of the ER Ca2+ ATPases, was larger in BiP-transfected than in control cells. The latter results were obtained also when BiP was overexpressed not via transfection but as a response to ER stress by tunicamycin. These results are sustained by increases of the ER Ca2+ storage capacity rather than by artifacts or indirect readjustments induced in the cells by the overexpression of the chaperone since (a) the exogenous and endogenous BiP were both confined to the ER, (b) the expression levels of other proteins active in the ER Ca2+ storage were not changed, and (c) effects similar to those of wild type BiP were obtained with a deletion mutant devoid of chaperone activity. The specificity of the results was confirmed by parallel 45Ca experiments carried out in HeLa cells transfected with two other Ca2+-binding proteins, calreticulin and CaBP2(ERp72), only the first of which induced increases of Ca2+ capacity. We conclude that BiP has a dual function, in addition to its chaperone role it is a bona fide ER lumenal Ca2+ storage protein contributing, under resting cell conditions, to around 25% of the store, with a stoichiometry of 1-2 moles of calcium/mole of BiP.

Metabolic Compartmentation in Living Cells: Structural Association of Aldolase

The glycolytic enzyme aldolase is concentrated in a domain around stress fibers in living Swiss 3T3 cells, but the mechanism by which aldolase is localized has not been revealed. We have recently identified a molecular binding site for F-actin on aldolase, and we hypothesized that this specific binding interaction, rather than a nonspecific mechanism, is responsible for localizing aldolasein vivo.In this report, we have used fluorescent analog cytochemistry of a site-directed mutant of aldolase to demonstrate that actin-binding activity localizes this molecule along stress fibers in quiescent cells and behind active ruffles in the leading edge of motile cells. The specific cytoskeletal association of aldolase could play a structural role in cytoplasm, and it may contribute to metabolic regulation, metabolic compartmentation, and/or cell motility. Functional duality may be a widespread feature among cytosolic enzymes.

From allergy to schistosomes: role of Fc receptors and adhesion molecules in eosinophil effector function.

The dual function of eosinophils has been evidenced in protective immunity against parasites as well as in pathological manifestations during allergic disorders. We have demonstrated that a new class of IgE receptors, Fc epsilon RII/CD23, was involved in the functional duality of eosinophils and other proinflammatory cells. More recently, we have shown that Fc epsilon RI, the high affinity IgE receptor thought to be only expressed by basophils and most cells, was involved in eosinophil-mediated cytotoxicity against schistosomes as well as in mediator release. These results favour the view that both IgE and its receptors have been primarily associated to a protective immune response, rather than to pathology. Not only IgE receptors but also members belonging to the family of adhesion molecules can participate as co-receptors in eosinophil effector function. The inhibitory role of monoclonal antibodies to Lewis(X) (Le(X) CD15) or to selectins in eosinophil-mediated cytotoxicity towards schistosomes and the detection of Le(X) and selectin-like molecules on schistosomula surface indicate a double interaction mediated by selectins and their carbohydrate ligands between eosinophils and schistosomula. These results suggest new functions for these adhesion molecules, previously known to be involved mainly in cell infiltration.

Anatomia funcional e biomecânica das articulações do tornozelo, subtalar e médio-társica

The study presents a review of the ankle and foot anatomy, giving basis for a better comprehension of this functional duality.

Molecular basis of angiotensin- and thrombin-induced endothelium-independent vasoconstriction and proliferation

In this report we describe our own attempt to explain the similarity of some effects of unique endogenous bioregulators such as angiotensin and thrombin at the molecular level. We also briefly review the cellular effects and signalling pathways of these molecules. Recent studies indicate that thrombin displays two opposing vascular effects: endothelium-dependent relaxation and endothelium-independent vasoconstriction. However, it should be noted that this enzyme possesses both vasocontractile and growth-stimulating activities which are similar to those of angiotensin. To examine a molecular basis for the functional duality of thrombin and similarity with angiotensin-induced effects, we analyzed the thrombin sequence and 3D structure. We found that (i) segment 84–135 of thrombin includes two angiotensin-like sites, which contain the repeats of the Tyr-Ile-His-Pro sequence and are identical to the functionally important fragment of angiotensin; and (ii) the thrombin 68–150 domain resembles the C-terminal tail of the macrophage migration inhibitory factor (MIF): five of the eight residues in angiotensin (Asp-Arg-Val-Tyr-Ile) are identical to fragment 94–98 of this one. Thus, angiotensin shares a surprisingly high degree of structural homology with both these molecules. We anticipated that angiotensin-like sites of thrombin (fragments 86–95 and 117–127) might be responsible for its vascular and growth-promoting activities on vascular smooth muscle cells. Taken together, the data obtained from a comparative analysis of thrombin, angiotensin and macrophage migration inhibitory factor-induced effects enable us to reveal the regulatory responsible domain of the enzyme and may prove useful for drug design.

Topological partition function and string-string duality

Evidence for string/string-duality can be given not only by matching the vector couplings but also by matching the gravitational couplings. In this note this is shown in the rank three example, the closest stringy analog of the Seiberg/Witten-setup, which is related to the Calabi-Yau WP 1,1,2,2,6 4(12). I provide an exact analytical verification of a relation checked by coefficient comparison to fourth order by Kaplunovsky, Louis and Theisen.

Professional Profiles and the Serving Teacher

Abstract Reference to profiles by the Teacher Training Agency is clearest in relation to initial training or newly‐qualified teachers, with a current emphasis on career entry profiles. The concept of career‐long professional development and comment on rolling profiles has extended this interest to serving teachers. As yet, there is little information of what this may mean. This paper asks what professional profiles may be in this context. It describes and comments on a brief questionnaire undertaken with teachers in Essex in late 1994. Finally, it identifies the major issues which presently underlie profiling in continuing professional development. In doing this, particular reference is made to duality of function, ownership and the relationship of profiles to portfolios. Some parts of this paper were presented at a conference of the Standing Council for the Education and Training of Teachers on 14 June 1995.

Molecular cloning and sequence analysis of striped bass (Morone saxatilis) gonadotrophin-I and -II subunits.

Two types of cDNA, each encoding a different beta-subunit of striped bass (Morone saxatilis, Teleostei) gonadotrophins (GTH-I beta and GTH-II beta), as well as the glycoprotein alpha-subunit, were cloned by screening a striped bass pituitary cDNA library. The probes used for screening the library were cloned cDNA fragments, generated by PCR amplification of reverse-transcribed mRNA obtained from two pituitaries. The nucleotide sequences of the alpha-subunit, GTH-I beta and GTH-II beta are 626, 524 and 580 bases long, encoding peptides of 117, 120 and 147 amino acids respectively. Striped bass GTH-I beta and GTH-II beta share a sequence identity of 48% at the nucleic acid level, and 30% at the amino acid level. A cluster analysis of vertebrate pituitary glycoprotein beta-subunits suggests that teleost GTH-II beta is more closely related to tetrapod LH than to FSH. Administration of gonadotrophin-releasing hormone analogue ([D-Ala6,Pro9Net]-LHRH) to juvenile striped resulted in ten-, two- and fivefold increases in the expression of the alpha-subunit, GTH-I beta and GTH-II beta respectively. These results suggest that each of the GTH subunits is differentially regulated, and further corroborate the functional duality of teleost gonadotrophins.

The Architecture of the Atrioventricular Conduction Axis in Dog Compared to Man:

AV Node in Dog and Man. Advances in treating patients with dual atrioventricular nodal pathways have called for a better understanding of the morphology of the approaches to the atrioventricular node. In this respect, it has recently been suggested that, in dog, anatomically discrete muscle bundles originating from the sinus node represent the substrate of the dual pathways recognized electrophysiologically in patients with atrioventricular nodal reentrant tachycardia. This concept is at odds with most anatomic studies of the human specialized atrioventricular junctional area. In this study, therefore, we studied histologically the junctional area in dog hearts, comparing them with our own findings in human heart and the descriptions of the earliest investigators. Five dog and six human hearts were prepared for histology and sectioned serially in different planes. Reconstructions were then made from each of three dog and two human hearts sectioned in orthogonal planes. Gross differences in the anatomy of the atrioventricular junctional area and in the structure of the conduction system were obvious between dog and human hearts. The penetrating portion of the conduction axis was longer in the dog, being much more extensively embedded in the central fibrous body. The atrioventricular node, in both dog and man, was composed of a zone of transitional cells overlying a compact region. The zone of transitional cells in the dog was more extensive posteriorly than anteriorly. No bundles insulated anatomically by fibrous tissue were found either in the internodal atrial myocardium or in the approaches to the atrioventricular node. Our findings in both dog and man are comparable with the initial descriptions of the atrioventricular junctional area. Although the disposition of the conduction system in dog and man is basically similar, there are important differences which relate to the gross anatomy. The anatomic substrate for functional duality of the inputs to the atrioventricular node remains unclear, since our study confirms that the concept of insulated atrionodal tract has no morphologic basis.

Identification of the urokinase receptor as an adhesion receptor for vitronectin.

Urokinase receptors, expressed on surfaces of many cell types, focus to the pericellular space plasminogen-dependent proteolysis important in matrix remodeling and cell movement. We now report that the urokinase receptor (uPAR) is also a high affinity (Kd < 30 nM) receptor for vitronectin. Recombinant uPAR binds vitronectin in the absence of urokinase, but vitronectin binding is promoted by concurrent receptor binding of either urokinase or fragments thereof containing its uPAR binding domain. Stable epithelial cell transfectants expressing membrane-anchored uPAR, but not cells expressing soluble uPAR, become strongly adhesive with altered morphology in the absence of urokinase. These observations identify a new class of vitronectin receptor and imply a duality in function for the receptor that intrinsically links matrix adhesion to regulation of protease activity. Increases in urokinase receptor expression known to be associated with cellular activation and malignant transformation could modulate cellular trafficking and function by promoting attachment to vitronectin.

The multifunctional TFIIH complex and transcriptional control

RNA polymerase II (Pol II) requires seven general transcription factors (GTFs) and ATP for transcription initiation. Transcription factor IIH (TFIIH) has emerged as the sole GTF with enzymatic activity. In addition to its essential role in transcription initiation, recent studies have demonstrated a direct involvement of TFIIH in DNA excision repair processes. The enzymatic properties and functional duality of TFIIH make it a prime target for regulation by viral and cellular factors.

Judicial Power, the Duality of Functions and the Administrative Appeals Tribunal

Judicial Power, the Duality of Functions and the Administrative Appeals Tribunal