Functional Duality Research Articles

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

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

A review of the neurophysiology of the turtle retina: Horizontal and bipolar cells

Horizontal and bipolar cells are second order neurons of the vertebrate retina. Horizontal cells contribute to the generation of centre/surround receptive field organisation in retinal neurons, primarily via sign-inverting feedback to cones. In turtle, there are two physiological types of horizontal cell, luminosity and chromaticity types. Feedback interactions between horizontal cells and cones underlie the emergence of colour opponent responses in the retina. The functional duality of colour opponent and noncolour opponent channels in the visual system, which in turtle and fish has its roots in interactions in the outer plexiform layer, persists to the cortex. Photoreceptors send output to two functional classes of bipolar cells. ON bipolar cells are depolarised by light and OFF bipolar cells are hyperpolarised by light. The segregation of ON and OFF channels of information, which starts at the level of bipolar cells, has profound significance for visual processing.

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

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

Atrioventricular nodal reentry. Clinical, electrophysiological, and therapeutic considerations.

Atrioventricular (AV) nodal reentry is a relatively common cause of regular, narrow QRS tachycardia. The underlying basis for this arrhythmia is functional (and anatomic) duality of pathways in the region of the AV node, although the exact boundaries of the reentrant circuit have not been convincingly defined. During the more common type of AV nodal reentry (seen in approximately 90% of cases), a slow conducting pathway is used in the anterograde direction, and a fast pathway is operative in the retrograde direction. In the uncommon form, the direction of impulse propagation within the reentrant circuit is reversed. In this article, the clinical, ECG, and electrophysiological features of AV nodal reentry as well as approaches to therapy are discussed. Clinical diagnosis may be made from the surface ECG. In the common type of AV nodal reentry, the P wave is obscured by the QRS or may be present in its terminal portion. The P wave in the uncommon form occurs late (i.e., in or after the T wave), producing a pattern of long RP and short PR. Both forms of AV nodal reentry are controllable with various therapeutic modalities. For acute termination, adenosine is probably the ideal agent. Prevention of recurrences can be achieved with several pharmacological agents, including beta-blockers, calcium channel blockers, and class Ia, Ic, and III antiarrhythmic agents. Curative therapy is now available with a variety of nonpharmacological methods. However, the most promising therapy at the present time is catheter modification of the AV node by ablation of either the fast or slow pathway, using radiofrequency energy. Ablation of the fast pathway carries a higher risk of second- or third-degree AV block. Slow pathway ablation, by providing a high rate of success and minimal risk of AV block, seems to be a more acceptable initial approach. AV nodal reentry is a common cause of paroxysmal supraventricular tachycardia, and a precise diagnosis can be made with intracardiac electrophysiological evaluation. Although the arrhythmia responds to a variety of antiarrhythmic agents, curative therapy can now be offered with catheter modification of the AV node using radiofrequency energy. At the time of this writing, it seems that catheter modification of the AV node is rapidly becoming the therapy of initial choice in patients with symptomatic AV nodal reentrant tachycardia requiring treatment.

Duality in the inelastic structure function and the disappearing Delta resonance.

We study the dual relationship between the resonances and the scaling curve for the inelastic structure function $\ensuremath{\nu}{W}_{2}$ in the ${Q}^{2}$ range 1 to 17 ${(\mathrm{G}\mathrm{e}\mathrm{V}/\mathit{c})}^{2}$. We focus on an exception to the rule that resonance bumps fall with increasing ${Q}^{2}$ at the same rate as the background, namely, the $\ensuremath{\Delta}(1232)$, for which the resonance falls faster than the background. We show that $\ensuremath{\nu}{W}_{2}$, averaged over suitable ranges of $x$, yields the smooth scaling curve seen at higher values of ${Q}^{2}$ at the same values of $x$, for all resonance regions. The fall of the $\ensuremath{\Delta}(1232)$ and corresponding rise of the background hints at a common dynamics for both.

Xinjiang's handicraft industry

This study examines the role of handicrafts in the development of tourism in Xinjiang, China. One year of fieldwork in Xinjiang involved surveys of handicraft factories. The proposition investigated is that international tourism causes an evolution of crafts into two types: touristic and ethnic crafts. The duality in form and function is matched by a duality in markets and resources. Within Xinjiang, Urumqi is found to be a modernized producer of touristic crafts while the significance of craft production in Turpan has been reduced. In contrast, tourism has encouraged certain types of craft production in Kashgar and Kucha, while less of an impact is present in Gulja.

Internal Diffusion Limited Aggregation

We study the asymptotic shape of the occupied region for an interacting lattice system proposed recently by Diaconis and Fulton. In this model particles are repeatedly dropped at the origin of the $d$-dimensional integers. Each successive particle then performs an independent simple random walk until it "sticks" at the first site not previously occupied. Our main theorem asserts that as the cluster of stuck particles grows, its shape approaches a Euclidean ball. The proof of this result involves Green's function asymptotics, duality and large deviation bounds. We also quantify the time scale of the model, establish close connections with a continuous-time variant and pose some challenging problems concerning more detailed aspects of the dynamics.

Dual function of eosinophils in pathogenesis and protective immunity against parasites.

The functional duality of eosinophils, involved in a protective response or in pathogenesis is illustrated in various parasitic infections. In schistosomiasis, eosinophils have been shown to mediate schistosomula killing, in the presence of antibodies. The association of eosinophil-dependent cytotoxic antibody isotypes with resistance of reinfection (IgE and IgA antibodies), whereas in vitro blocking antibody isotypes (IgG4, IgM) were detected in susceptible subjects, suggested a participation of eosinophils in antibody-dependent protective response. However eosinophils could participate to granuloma formation and consequently to the pathological reactions during schistosomiasis. Activation of eosinophils by antibodies, leading to release of granule proteins have been studied in patients with filariasis. Eosinophil peroxidase, EPO was released after IgE-dependent activation whereas Eosinophil Cationic Protein, ECP, was released after IgG- and IgA-dependent activation of eosinophils, results suggesting a process of differential release of mediators. Interactions between eosinophils and interleukins, and specially IL-5 are discussed. Whereas a receptor for IL-5 has been characterized on human eosinophils, recent studies have shown that eosinophils expressed the messenger RNA encoding IL-5. These results associated to data showing the synthesis of other cytokines indicate that eosinophils are not only the source of cytotoxic mediators involved in the effector phase of immunity but also of growth and regulatory factors, participating to immunoregulation.

Functional duality and structural uniqueness of the depressant insect-selective neurotoxins

Depressant insect-selective neurotoxins derived from scorpion venoms (a) induce in blowfly larvae a short, transient phase of contraction similar to that induced by excitatory neurotoxins followed by a prolonged flaccid paralysis and (b) displace excitatory toxins from their binding sites on insect neuronal membranes. The present study was undertaken in order to examine the basis of these similarities by comparing the primary structures and neuromuscular effects of depressant and excitatory toxins. A new depressant toxin (LqhIT2) was purified from the venom of the Israeli yellow scorpion. The effects of this toxin on a prepupal housefly neuromuscular preparation mimic the effects on the intact animal; i.e., a brief period of repetitive bursts of junction potentials is followed by suppression of their amplitude and finally by a block of neuromuscular transmission. Loose patch clamp recordings indicate that the repetitive activity has a presynaptic origin in the motor nerve and closely resembles the effect of the excitatory toxin AaIT. The final synaptic block is attributed to neuronal membrane depolarization, which results in an increase in spontaneous transmitter release; this effect is not induced by excitatory toxin. The amino acid sequences of three depressant toxins were determined by automatic Edman degradation. The depressant toxins comprise a well-defined family of polypeptides with a high degree of sequence conservation. This group differs considerably in primary structure from the excitatory toxin, with which it shares identical or related binding sites, and from the two groups of scorpion toxins that affect sodium conductance in mammals. The two opposing pharmacological effects of depressant toxins are discussed in light of the above data.

ON THE COMPUTATION OF MULTIPHASE EQUILIBRIA

The main purpose of this paper is to present a new mathematical programming formulation of the multiphase equilibrium problem along with a Newton-type algorithm for its solution. The approach pursued relies on the Gibbs free energy function and geometric programming duality. The problem arised in connection with a real-life problem in oil reservoir engineering. The presentation of the model is based on a detailed mathematical analysis of the multiphase equilibrium problem. The computational results reported are obtained using data systems from oil reservoir engineering.

Quantum chromodynamics and Bloom-Gilman duality.

We study the quantum-chromodynamic explanation of the long-established empirical connection, called Bloom-Gilman duality, between scaling and resonance regimes of the inelastic structure function $\ensuremath{\nu}{W}_{2}({\ensuremath{\omega}}^{\ensuremath{'}})$, where $\ensuremath{\nu}$ and ${\ensuremath{\omega}}^{\ensuremath{'}}$ are the usual kinematic variables. We show how QCD expectations for the baryon transition form factors lead to the observed constancy with momentum transfer of the resonance/"background" ratio. We can also understand why the resonance contribution follows with changing ${Q}^{2}$, a curve whose shape is the same as the scaling-limit curve. We comment on the longitudinal response function and on possible contrasts in exciting resonances with different isospins. These await experimental scrutiny in newer-generation electron facilities.

Int-2: A Member of the Fibroblast Growth Factor Family Has Different Subcellular Fates Depending on the Choice of Initiation Codon

The int-2 gene, which encodes a member of the fibroblast growth factor family, was discovered as a protooncogene transcriptionally activated following proviral insertion into adjacent chromosomal DNA. Analyses of the synthesis and processing of the int-2 protein, using an SV40-based vector to express cloned cDNA, showed four major products in the size range 27.5-31.5 kd that were associated with the secretory pathway. Further experiments using a cell-free translation system programmed with int-2 cRNA revealed a larger N-terminally extended protein. Site-directed mutagenesis of possible initiation codons confirmed that the first in-frame AUG codon would specify the start of a protein that includes a signal peptide for transport into the endoplasmic reticulum. However, protein synthesis also initiates at an upstream CUG codon to yield a polypeptide extended at the N-terminus by 29 amino acids. Immunofluorescent staining showed that a substantial proportion of the CUG-initiated protein resides in the cell nucleus, while a truncated int-2, lacking both the N-terminal extension and the signal peptide, was exclusively nuclear. These observations suggest that a nuclear localisation signal occurs in the body of the int-2 molecule, but is only accessible to the nuclear transport system if entry to the secretory pathway is compromised. Thus, the choice of initiation codon changes the subcellular fate of the int-2 protein and provides the potential for a duality of function through alternative transport pathways.

Profit Function Approximations and Duality Applications to Agriculture

AbstractMonte Carlo simulations of profit functions indicate that flexible functional forms may be ranked nearly the same with respect to Allen‐Uzawa partial substitution elasticities or price and fixed factor elasticities. Flexible functional form approximations of output price elasticities are generally worse than approximations of input price or fixed factor elasticities. Minflex Laurent functional forms did not appear to approximate underlying elasticities any better than did their translog and generalized Leontief counterparts.

ChemInform Abstract: Chemical Chameleons. Organosulfones as Synthetic Building Blocks

An overview of the duality of function of organosulfones as nucleophiles in basic media and electrophiles in Lewis acidic media, a change of reactivity for which they have been dubbed “chemical chameleons,” is presented. In the first phase, transition metal catalysts activate allyl sulfones towards displacements. Use of palladium, molybdenum, and nickel catalysts allow stabilized anions to effect displacement; copper catalysts allow non-stabilized nucleophiles to be used. The use of the anion stabilizing and leaving group abilities of sulfones created a novel three carbon intercalation and a novel cyclocontraction-spiroannulation in which β-hydroxy sulfones participate in a Lewis acid catalyzed pinacol rearrangement. The lability of allyl and tertiary sulfones towards Lewis acids creates a wide array of electrophilic reactions such as Friedel–Crafts type cyclizations, intermolecular alkylations with organoalanes and enol silyl ethers, and ring expansions. The ability to design novel reagents for synthesis...

ON METHODS FOR DISCRETE STRUCTURAL OPTIMIZATION

Abstract Three algorithms for discrete structural optimization are considered. The original discrete structural optimization problem is replaced by a sequence of approximate discrete subproblems. For small size problems a Branch and Bound method is used to find a global minimum for each subproblem. The use of a generalized Lagrangean function and nonconvex duality is compared to the use of the Branch and Bound method. The generalized Langrangean function is minimized over the discrete set using a neighbourhood search technique. The dual function is maximized using a subgradient method. A method for rounding off the continuous solution is also used. The performance of the algorithms is investigated on several numerical examples. Global discrete minima are found for two convex test problems by using Branch and Bound on the original discrete structural optimization problem.

Chemical Chameleons. Organosulfones as Synthetic Building Blocks

Abstract An overview of the duality of function of organosulfones as nucleophiles in basic media and electrophiles in Lewis acidic media, a change of reactivity for which they have been dubbed “chemical chameleons,” is presented. In the first phase, transition metal catalysts activate allyl sulfones towards displacements. Use of palladium, molybdenum, and nickel catalysts allow stabilized anions to effect displacement; copper catalysts allow non-stabilized nucleophiles to be used. The use of the anion stabilizing and leaving group abilities of sulfones created a novel three carbon intercalation and a novel cyclocontraction-spiroannulation in which β-hydroxy sulfones participate in a Lewis acid catalyzed pinacol rearrangement. The lability of allyl and tertiary sulfones towards Lewis acids creates a wide array of electrophilic reactions such as Friedel–Crafts type cyclizations, intermolecular alkylations with organoalanes and enol silyl ethers, and ring expansions. The ability to design novel reagents for synthesis based upon this dual reactivity of organosulfones is illustrated by the use of an alkoxy-bis(phenylsulfonyl)methane as a synthon for a carbonyl 1,1-dipole.

Decoupling and pole placement in singular systems using state and output feedback

We consider linear time-invariant singular systems, which can be decoupled via a Proportional-derivative ( PD) feedback of special form. A method based on a transfer function duality property is proposed for simultaneous decoupling and pole placement by using an augmented system designed for this purpose. A method is also presented for decoupling and pole placement of singular systems via output feedback.

Hypothalamic temperature and deep body temperature during copulation in the male rat

The medial preoptic area (MPOA) of the hypothalamus is involved in both the expression of male sexual behavior and the regulation of physiological temperature. This duality of function led us to ask whether arousal, intromission, and ejaculation are accompanied by a distinctive temperature profile. Using telemetric thermosensors, we monitored MPOA temperature and deep body temperature during copulation in the male rat. Changes in MPOA temperature were highly uniform, more so than changes in body temperature. The MPOA heated prior to ejaculation, cooled rapidly following ejaculation and then began to heat again coincident with the termination of the post-ejaculatory refractory period. These changes could not be related to variations in general activity. The most striking change in MPOA temperature, rapid cooling following ejaculation, was explained in terms of certain behaviorally-induced hemodynamic events.

Duality of Distribution Functions

Duality of Distribution Functions

Functional calculus and duality for closed operators

In this paper, we continue our spectral-theoretic study [8] of unbounded closed operators in the framework of the spectral decomposition property and decomposable operators. Given a closed operator T with nonempty resolvent set, let f → f( T) be the homomorphism of the functional calculus. We show that if T has the spectral decomposition property, then f( T) is decomposable. Conversely, if f is nonconstant on every component of its domain which intersects the spectrum of T, then f( T) decomposable implies that T has the spectral decomposition property. A spectral duality theorems follows as a corollary. Furthermore, we obtain an analytic-type property for the canonical embedding J of the underlying Banach space X into its second dual X ∗∗ .