bluuebunny/crossref_metadata_2025 huggingface dataset:
The “environmental sustainability” problem
Authors: Newport Dave , Chesnes Thomas , Lindner Angela
Published: September 2003

While the concept of “sustainability” traditionally has emphasized the environment, the University of Florida (UF) has learned that integrating all three “legs of the sustainability stool” is a prerequisite to effecting the comprehensive institutional change sustainability proponents seek. By assessing its own degree of sustainability using guidelines established by the Global Reporting Initiative, UF united the interests of the administration with those of campus greening and social progressive constituents and, in the process, established a baseline with which to compare future metrics. Universities,are poised to gain from lessons learned outside of academia and, as at UF, are beginning to reach out not only to environmental interests, but also to social and economic constituencies. The objectives of this paper are to identify and address the major obstacles facing institutionalization of sustainability in the university as evidenced by UF's own experiences and to provide solutions for boosting the university's status as leaders in the sustainability arena.
Regional distribution of hyperpolarization‐activated current (If) and hyperpolarization‐activated cyclic nucleotide‐gated channel mRNA expression in ventricular cells from control and hypertrophied rat hearts
Authors: Fernández‐Velasco María , Goren Nora , Benito Gemma , Blanco‐Rivero Javier , Boscá Lisardo , Delgado Carmen
Published: September 2003

Hyperpolarization‐activated inward current (If) and changes in the messenger RNA (mRNA) expression levels of hyperpolarization‐activated cyclic nucleotide‐gated channel (HCN)2 and HCN4 encoding If channels of the rat heart were studied in control and hypertrophied myocytes isolated from three ventricular regions: the septum (S), the left ventricular free wall (LV) and the right ventricular free wall (RV). Electrophysiological experiments were conducted by ruptured and perforated‐patch clamp techniques and quantification of mRNA levels was carried out by quantitative reverse transcriptase polymerase chain reaction. The occurrence, density and maximal specific conductance of If were found to be significantly higher in hypertrophied ventricular myocytes isolated from S and LV than in those isolated from RV or sham‐operated rats. Half‐maximal activation potential, the slope of the activation curve and the threshold for activation were similar in ventricular myocytes from sham and aortic stenosed rats in the three regions studied. Isoproterenol 1 µmol l−1 increased current size by shifting current activation to more positive potentials in both sham and hypertrophied myocytes. When we studied the mRNA levels of If channel isoforms present in the ventricle, we found a significant increase of HCN2 and HCN4 mRNA levels in hypertrophied myocytes from S and LV but not in RV. We conclude that the occurrence, density and conductance of If is higher in hypertrophied than in control ventricular myocytes, S being the region where all these changes were most evident. These findings are associated with a higher expression of HCN2 and HCN4 mRNA levels in the two regions that developed hypertrophy.
Acidosis inhibits oxidative phosphorylation in contracting human skeletal musclein vivo
Authors: Jubrias Sharon A. , Crowther Gregory J. , Shankland Eric G. , Gronka Rodney K. , Conley Kevin E.
Published: September 2003

This study tested the hypothesis that acidic pH inhibits oxidative ATP supply during exercise in hand (first dorsal interosseus, FDI) and lower limb (leg anterior compartment, LEG) muscles. We measured oxidative flux and estimated mitochondrial capacity using the changes in creatine phosphate concentration ([PCr]) and pH as detected by31P magnetic resonance (MR) spectroscopy during isometric exercise and recovery. The highest oxidative ATP flux in sustained exercise was about half the estimated mitochondrial capacity in the LEG (0.38 ± 0.06vs. 0.90 ± 0.14 mmATP s−1, respectively), but at the estimated capacity in the FDI (0.61 ± 0.05vs. 0.61 ± 0.09 mmATP s−1, respectively). During sustained exercise at a higher contraction rate, intracellular acidosis (pH < 6.88) prevented a rise in oxidative flux in the LEG and FDI despite significantly increased [ADP]. We tested whether oxidative flux could increase above that achieved in sustained exercise by raising [ADP] (> 0.24 mm) and avoiding acidosis using burst exercise. This exercise raised oxidative flux (0.69 ± 0.05 mmATP s−1) to nearly twice that found with sustained exercise in the LEG and matched (0.65 ± 0.11 mmATP s−1) the near maximal flux seen during sustained exercise in the FDI. Thus both muscles reached their highest oxidative fluxes in the absence of acidosis. These results show that acidosis inhibits oxidative phosphorylationin vivoand can limit ATP supply in exercising muscle to below the mitochondrial capacity.
A Learned Component of the Ventilatory Response to Exercise in Man
Authors: Wood Helen E. , Fatemian Marzieh , Robbins Peter A.
Published: September 2003

The ventilatory response to mild‐to‐moderate exercise in humans is isocapnic, or ‘error‐free’. It has been suggested that this response is learned over many repetitions of exercise through the process of minimising any deviations from normal in the blood gas tensions, as sensed by the chemoreceptors. However, relatively limited training programmes have failed to produce any convincing evidence in humans that forcibly altering the blood gas tensions during repeated periods of exercise alters the subsequent steady‐state ventilatory response to exercise. In this study, eight healthy young subjects were exposed, over a 7 day training period, to a total of 70 repeated bouts of exercise paired with a simultaneous airway CO2 load to stimulate the chemoreceptors (protocol EX + CO2). The ventilatory response to exercise was measured before and after training to determine whether it had been modified. Two further training protocols were undertaken as controls. One employed repeated exercise without an airway CO2 load, and the other employed repeated airway CO2 loading without exercise. On the 1st and 2nd days following training with protocol EX + CO2, end‐tidal PCO2 was regulated at a lower level during steady‐state exercise than following training with the control protocols and than before training (mean ±s.e.m. reduction in end‐tidal PCO2= 1.32 ± 0.36 Torr, ANOVA, P < 0.05). In contrast to previous studies, this finding demonstrates that the steady‐state ventilatory response to exercise can be modified by a prior period of altered chemoreception during exercise. This suggests that ventilation is matched to metabolic rate during exercise by a mechanism that involves learning and memory.
Crossing the Pain Barrier: P2 Receptors as Targets for Novel Analgesics
Authors: Kennedy C. , Assis T. S. , Currie A. J. , Rowan E. G.
Published: September 2003

In 1995 the P2X3 receptor was found to be expressed at high levels in nociceptive sensory neurones, consistent with earlier reports that ATP induced pain in humans and animals. At first it was thought that ATP was most likely to play a role in acute pain, following its release from damaged or stressed cells and since then a wide variety of experimental techniques and approaches have been used to study this possibility. Whilst it is clear that exogenous and endogenous ATP can indeed acutely stimulate sensory neurones, more recent reports using gene knockout and antisense oligonucleotide technologies, and a novel, selective P2X3 antagonist, A‐317491, all indicate that ATP and P2X3 receptors are more likely to be involved in chronic pain conditions, particularly chronic inflammatory and neuropathic pain. These reports indicate that P2X3 receptors on sensory nerves may be tonically activated by ATP released from nearby damaged or stressed cells, or perhaps from the sensory nerves themselves. This signal, when transmitted to the CNS, will be perceived consciously as chronic pain. In addition, it is now clear that several subtypes of P2Y receptor are also expressed in sensory neurones. Although their distribution and functions have not been as widely studied as P2X receptors, the effects that they mediate indicate that they might also be considered as therapeutic targets in the treatment of pain. Although our ability to treat persistent painful conditions, such as chronic inflammatory and neuropathic pain, has improved in recent years, these conditions are often resistant to currently available therapies, such as opioids or non‐steroidal anti‐inflammatory drugs. This reflects a limited understanding of the underlying pathophysiology. It is now clear that the development and maintenance of chronic pain are mediated by multiple factors, but many of these factors, and the receptors and mechanisms through which they act, remain to be identified. Chronic pain is debilitating and can greatly decrease quality of life, not just due to the pain per se, but also because of the depression that can often ensue. Thus a greater understanding of the mechanisms that underlie chronic pain will help identify new targets for novel analgesics, which will be of great therapeutic benefit to many people.
Migrating Motor Complexes do not Require Electrical Slow Waves in the Mouse Small Intestine
Authors: Spencer Nick J. , Sanders Kenton M. , Smith Terence K.
Published: September 2003

We have investigated whether migrating motor complexes (MMCs) are impaired or absent in the small intestine of W/Wv mutant mice, which lack pacemaker interstitial cells of Cajal (ICC) and electrical slow waves. The intracellular electrical and mechanical activities of the small intestines of wild‐type (+/+) and W/Wv mutant mice were recorded. Electrical recordings from circular muscle cells confirmed the absence of slow waves in W/Wv mice, whereas slow waves were always recorded from +/+ muscle cells. Spontaneous phasic contractions were recorded from W/Wv muscles in the absence of slow waves, but these events occurred at a lower frequency than in +/+ tissues. MMC activity was recorded consistently from the ileum of +/+ mice, and normal MMCs were also recorded from W/Wv mice. MMCs in both +/+ and W/Wv mice were abolished by tetrodotoxin (1 μm), hexamethonium (300 μm) or atropine (1 μm), suggesting that the neural control mechanisms responsible for MMCs in +/+ mice are intact and are responsible for MMCs in W/Wv mice. Transmural nerve stimulation demonstrated intact inhibitory and excitatory neural regulation of W/Wv intestinal muscles. Prolonged trains of cholinergic motor nerve stimulation failed to activate slow waves in the intestinal muscles of W/Wv mice. Our findings show that the generation and directional propagation of MMC activity in mouse small intestine does not require slow‐wave activity or an intact network of myenteric ICC. The generation and propagation of MMCs appear to be an intrinsic capability of the enteric nervous system and are not related to slow waves or the gradient in slow‐wave frequency.
Potentiation of Quantal Secretion by Insulin‐Like Growth Factor‐1 at Developing Motoneurons in Xenopus Cell Culture
Authors: Liou Jau‐Cheng , Tsai Fong‐Zu , Ho Shih‐Yin
Published: September 2003

Although evidence suggests that insulin‐like growth factor (IGF) plays an important role in the development and growth of the nervous system, the effect of IGF‐1 in the regulation of neurotransmitter release in the peripheral nervous system remains unknown. Here we show that acute application of IGF‐1, a factor widely expressed in developing myocytes, dose‐dependently enhances the spontaneous acetylcholine (ACh) secretion at developing neuromuscular synapses in Xenopus cell culture using whole‐cell patch clamp recording. We studied the role of endogenously released IGF‐1 by examining the effect of IGF‐1 antibody on the frequency of spontaneous synaptic currents (SSCs) at high‐activity synapses, and found SSC frequency was markedly reduced at these high‐activity synapses. The IGF‐1‐induced synaptic potentiation was not abolished when Ca2+ was eliminated from the culture medium or there was bath‐application of the pharmacological Ca2+ channel inhibitor Cd2+, indicating that Ca2+ influxes through voltage‐activated Ca2+ channels are not required. Application of membrane‐permeable inhibitors of inositol 1,4,5‐trisphosphate (IP3) or ryanodine receptors effectively occluded the increase of SSC frequency elicited by IGF‐I. Treating cells with the phosphoinositide‐3 kinase (PI3‐K) inhibitors wortmannin or LY294002, and with phospholipase Cγ (PLCγ) inhibitor U73122, but not the inhibitor of mitogen‐activated protein (MAP) kinase PD98059, abolished IGF‐1‐induced synaptic potentiation. Taken collectively, these results suggest that endogenously released IGF‐1 from myocytes elicits Ca2+ release from IP3‐ and/or ryanodine‐sensitive intracellular Ca2+ stores of the presynaptic nerve terminal. This is done via PI3‐K and PLCγ signalling cascades, leading to an enhancement of spontaneous transmitter release.
Glycine Receptors and Glycinergic Synaptic Input at the Axon Terminals of Mammalian Retinal Rod Bipolar Cells
Authors: Cui Jinjuan , Ma Yu‐Ping , Lipton Stuart A. , Pan Zhuo‐Hua
Published: September 2003

We investigated the properties of glycine receptors and glycinergic synaptic inputs at the axon terminals of rod bipolar cells (RBCs) in rats by patch‐clamp recording. Glycine currents recorded from isolated axon terminals were larger than those from isolated somata/dendrites; this was confirmed by puffing glycine onto these two regions in retinal slices. The current density at terminal endings was more than one order of magnitude higher than the density at somatic/dendritic regions. Glycine currents from isolated terminals and isolated somata/dendrites showed similar sensitivity to picrotoxinin blockade. Single‐channel opening recorded from isolated terminals and somata/dendrites displayed a similar main‐state conductance of ≈46 pS. Application of glycine effectively suppressed depolarization‐evoked increases in intracellular Ca2+ at the terminals. In the presence of GABAA and GABAC antagonists, strychnine‐sensitive chloride currents were evoked in RBCs in retinal slices by puffing kainate onto the inner plexiform layer. No such currents were observed if the recorded RBCs did not retain axon terminals or if Ca2+ was replaced by Co2+ in the extracellular solution. The currents displayed discrete miniature‐like events, which were partially blocked by tetrodotoxin. Consistent with early studies in the rabbit and mouse, this study demonstrates that glycine receptors are highly concentrated at the axon terminals of rat RBCs. The pharmacological and physiological properties of glycine receptors located in the axon terminal and somatic/dendritic regions, however, appear to be the same. This study provides evidence for the existence of functional glycinergic synaptic input at the axon terminals of RBCs, suggesting that glycine receptors may play a role in modulating bipolar cell synaptic transmission.
Intramyocellular lipids form an important substrate source during moderate intensity exercise in endurance‐trained males in a fasted state
Authors: van Loon Luc J. C. , Koopman René , Stegen Jos H. C. H. , Wagenmakers Anton J. M. , Keizer Hans A. , Saris Wim H. M.
Published: September 2003

Both stable isotope methodology and fluorescence microscopy were applied to define the use of intramuscular triglyceride (IMTG) stores as a substrate source during exercise on a whole‐body as well as on a fibre type‐specific intramyocellular level in trained male cyclists. Following an overnight fast, eight subjects were studied at rest, during 120 min of moderate intensity exercise (60 % maximal oxygen uptake capacity (V̇O2,max)) and 120 min of post‐exercise recovery. Continuous infusions of [U‐13C]palmitate and [6,6‐2H2]glucose were administered at rest and during subsequent exercise to quantify whole‐body plasma free fatty acid (FFA) and glucose oxidation rates and the contribution of other fat sources (sum of muscle‐ plus lipoprotein‐derived TG) and muscle glycogen to total energy expenditure. Fibre type‐specific intramyocellular lipid content was determined in muscle biopsy samples collected before, immediately after and 2 h after exercise. At rest, fat oxidation provided 66 ± 5 % of total energy expenditure, with FFA and other fat sources contributing 48 ± 6 and 17 ± 3 %, respectively. FFA oxidation rates increased during exercise, and correlated well with the change in plasma FFA concentrations. Both the use of other fat sources and muscle glycogen declined with the duration of exercise, whereas plasma glucose production and utilisation increased (P < 0.001). On average, FFA, other fat sources, plasma glucose and muscle glycogen contributed 28 ± 3, 15 ± 2, 12 ± 1 and 45 ± 4 % to total energy expenditure during exercise, respectively. Fluorescence microscopy revealed a 62 ± 7 % net decline in muscle lipid content following exercise in the type I fibres only, with no subsequent change during recovery. We conclude that IMTG stores form an important substrate source during moderate intensity exercise in endurance‐trained male athletes following an overnight fast, with the oxidation rate of muscle‐ plus lipoprotein‐derived TG being decreased with the duration of exercise.
Carbenoxolone Blockade of Neuronal Network Activity in Culture is not Mediated by an Action on Gap Junctions
Authors: Rouach N. , Segal M. , Koulakoff A. , Giaume C. , Avignone E.
Published: September 2003

Spontaneous activity in the central nervous system is strongly suppressed by blockers of gap junctions (GJs), suggesting that GJs contribute to network activity. However, the lack of selective GJ blockers prohibits the determination of their site of action, i.e. neuronal versus glial. Astrocytes are strongly coupled through GJs and have recently been shown to modulate synaptic transmission, yet their role in neuronal network activity was not analysed. The present study investigated the effects and site of action of the GJ blocker, carbenoxolone (CBX), on neuronal network activity. To this end, we used cultures of hippocampal or cortical neurons, plated on astrocytes. In these cultures neurons display spontaneous synchronous activity and GJs are found only in astrocytes. CBX induced in these neurons a reversible suppression of spontaneous action potential discharges, synaptic currents and synchronised calcium oscillations. Moreover, CBX inhibited oscillatory activity induced by the GABAA antagonist, bicuculline. These effects were not due to blockade of astrocytic GJs, since they were not mimicked nor occluded by endothelin‐1 (ET‐1), a peptide known to block astrocytic GJs. Also, these effects were still present in co‐cultures of wild‐type neurons plated on astrocytes originating from connexin‐43 (Cx43) knockout mice, and in neuronal cultures which contain few isolated astrocytes. CBX was not likely to exert its effect through neuronal GJs either, as immunostaining for major neuronal connexins (Cx) as well as dye or electrical coupling, were not detected in the different models of cultured neurons examined. Finally while CBX (at 100 μm) did not modify presynaptic transmitter release and postsynaptic responses to glutamate, it did cause an increase in the action potential threshold and strongly decreased the firing rate in response to a sustained depolarising current. These data demonstrate that CBX does not exert its action on network activity of cultured neurons through astrocytic GJs and suggest that it has direct effects on neurons, not involving GJs.
Glacial Earthquakes
Authors: Ekström Göran , Nettles Meredith , Abers Geoffrey A.
Published: September 2003

We have detected dozens of previously unknown, moderate earthquakes beneath large glaciers. The seismic radiation from these earthquakes is depleted at high frequencies, explaining their nondetection by traditional methods. Inverse modeling of the long-period seismic waveforms from the best-recorded earthquake, in southern Alaska, shows that the seismic source is well represented by stick-slip, downhill sliding of a glacial ice mass. The duration of sliding in the Alaska earthquake is 30 to 60 seconds, about 15 to 30 times longer than for a regular tectonic earthquake of similar magnitude.
Juggling law, ethics, and intuition: practical answers to awkward questions
Authors: Sommerville A
Published: September 2003

The eclectic problem solving methodology used by the British Medical Association (BMA) is described in this paper. It has grown from the daily need to respond to doctors’ practical queries and incorporates reference to law, traditional professional codes, and established BMA policies—all of which must be regularly assessed against the benchmark of contemporary societal expectations. The two Jehovah’s Witness scenarios are analysed, using this methodology and in both cases the four principles solution is found to concur with that of the BMA’s approach. The author’s overall conclusion is that although the BMA resorts to a lengthier list of thins to consider, the solutions that emerge are often likely to coincide with the four principles approach.
The virtues (and vices) of the four principles
Authors: Campbell A V
Published: September 2003

Despite tendencies to compete for a prime place in moral theory, neither virtue ethics nor the four principles approach should claim to be superior to, or logically prior to, the other. Together they provide a more adequate account of the moral life than either can offer on its own. The virtues of principlism are clarity, simplicity and (to some extent) universality. These are well illustrated by Ranaan Gillon’s masterly analysis of the cases he has provided. But the vices of this approach are the converse of its virtues: neglect of emotional and personal factors, oversimplification of the issues, and excessive claims to universality. Virtue ethics offers a complementary approach, providing insights into moral character, offering a blend of reason and emotion, and paying attention to the context of decisions. The cases provided can be more adequately understood if we combine the approaches. Both should foster the virtues of humility and magnanimity.
In praise of unprincipled ethics
Authors: Harris J
Published: September 2003

In this paper a plea is made for an unprincipled approach to biomedical ethics, unprincipled of course just in the sense that the four principles are neither the start nor the end of the process of ethical reflection. While the four principles constitute a useful “checklist” approach to bioethics for those new to the field, and possibly for ethics committees without substantial ethical expertise approaching new problems, it is an approach which if followed by the bioethics community as a whole would, the author believes, lead to sterility and uniformity of approach of a quite mindbogglingly boring kind. Moreover, much of bioethics is not concerned with identifying the principles or values appropriate to a particular issue, but rather involves analysing the arguments that are so often already in play and which present themselves as offering solutions in one direction or another. Here, as I try to show in discussion of these four scenarios, the principles allow massive scope in interpretation and are, frankly, not wonderful as a means of detecting errors and inconsistencies in argument.
Ideal Spaces of the Haagerup Tensor Product of C*-Algebras
Authors: Archbold Robert J. , Somerset Douglas W. B. , Kaniuth Eberhard , Schlichting Günter
Published: September 2003

Following the work of Allen, Sinclair and Smith on the primitive ideal space of the Haagerup tensor product A ⊗ hB of C*-algebras A and B, we investigate the hull-kernel topology and use this to determine various other ideal spaces and their topologies in relation to the corresponding ideal spaces of A and B. We study the semi-continuity of norm functions I → ||x + I||(x ∈ A ⊗h B) on these ideal spaces and identify the separated points of Prim (A ⊗h B). Finally, we exhibit several conditions each of which is equivalent to the quasi-standardness of A ⊗h B.
Harmonic Maps and Morphisms from Multilinear Norm-Preserving Mappings
Authors: Baird Paul , Ou Ye-Lin
Published: September 2003

We extend the notion of orthogonal multiplication to multilinear norm-preserving mapping, using them to construct new eigenmaps into spheres. We characterize those which are harmonic morphisms.

By the method of reduction we construct interesting families of harmonic morphisms into S2 from the product manifolds H2 × S3 and S3 × S3 of hyperbolic spaces and spheres. The corresponding reduction equation depends on two independent variables. We are able to solve the first-order horizontal conformality problem explicitly in terms of elliptic functions and then render the map harmonic by a conformal deformation of the metric.
An Analogue of Longo's Canonical Endomorphism for Bimodule Theory and Its Application to Asymptotic Inclusions
Authors: Masuda Toshihiko
Published: September 2003

We give an analogous characterization of Longo's canonical endomorphism in the bimodule theory, and by using this, we construct an inclusion of factors of type II 1 from a finite system of bimodules as a parallel construction to that of Longo–Rehren in a type III setting. When the original factors are approximately finite dimensional, we prove this new inclusion is isomorphic to the asymptotic inclusion in the sense of Ocneanu. This solves a conjecture of Longo–Rehren.
Quaternionic Transformations of a Non-Positive Quaternionic Kähler Manifold
Authors: Alekseevsky D. V. , Marchiafava S.
Published: September 2003

Let (M,g,Q) be a simply connected, complete, quaternionic Kähler manifold without flat de Rham factor. Then any 1-parameter group of transformations of M which preserve the quaternionic structure Q preserves also the metric g. Moreover, if (M,g) is irreducible then the quaternionic Kähler metric g on (M,Q) is unique up to a homothety.
The Exponential Decay Rate of the Lower Bound for the First Eigenvalue of Compact Manifolds
Authors: Kalka Morris , Mann Elizabeth , Yang Dagang , Zinger Aleksey
Published: September 2003

This paper provides the optimal exponential decay rate of the lower bound for the first positive eigenvalue of the Laplacian operator on a compact Riemannian manifold with a negative lower bound on the Ricci curvature and with large diameter. For manifolds with boundary, suitable convexity conditions are assumed.
Stable Rank of Some Full Group C*-Algebras of Groups Obtained by the Free Product
Authors: Nagisa Masaru
Published: September 2003

We compute the real rank and the stable rank of full group C*-algebras. Main result is (i) rr (C*(Fn)) = ∞, (ii) sr (C*(G1 * G2)) = ∞(|G1| ≥ 2, |G2| ≥ 2 and |G1| + |G2| ≥ 5), (iii) sr (C*(G1 * G2)) = 1(|G1| = |G2| = 2), where Fn is the free group with n generators, G1 and G2 are finite groups and |G| means the order of the group G.
The Structure of Positive Elements for C*-Algebras with Real Rank Zero
Authors: Perera Francesc
Published: September 2003

In this paper we give a representation theorem for the Cuntz monoid S(A) of a σ-unital C*-algebra A with real rank zero and stable rank one, which allows to prove several Riesz decomposition properties on the monoid. As a consequence, it is proved that the comparability conditions (FCQ), stable (FCQ) and (FCQ+) are equivalent for simple C*-algebras with real rank zero. It is also shown that the Grothendieck group [Formula: see text] of S(A) is a Riesz group, and lattice-ordered under some additional assumptions on A.
The Riemannian Goldberg–Sachs Theorem
Authors: Apostolov V. , Gauduchon P.
Published: September 2003

The paper contains a description of compact Hermitian complex surfaces whose Riemannian Ricci tensor is of type (1,1). This in turn comes as a consequence of a Riemannian version of the well-known (generalized) Goldberg–Sachs theorem of the General Relativity. A complete proof of the Riemannian version is given in the framework of "classical" Hermitian geometry. The paper includes some more results also pertaining to "Riemannian Goldberg–Sachs theory", as well as a "dual theory" involving the Penrose operator.
Melvin–Morton Conjecture and Primitive Feynman Diagrams
Authors: Vaintrob Arkady
Published: September 2003

We give a very short proof of the Melvin–Morton conjecture relating the colored Jones polynomial and the Alexander polynomial of knots. The proof is based on explicit evaluation of the corresponding weight systems on primitive elements of the Hopf algebra of chord diagrams which, in turn, follows from simple identities between four-valent tensors on the Lie algebra sl2 and the Lie superalgebra gl(1|1). This shows that the miraculous connection between the Jones and Alexander invariants follows from the similarity (supersymmetry) between sl2 and gl(1|1).
Non-Commutative Deformations of C(T2) and K-Theory
Authors: Cerri Cristina
Published: September 2003

For each α ≥ 0, let Bα be the universal C*-algebra generated by unitary elements uα, vα and a self-adjoint hα such that ||hα|| ≤ α and [Formula: see text]. In this work we prove that the family {Bα}α ∈ [0,∞[ extend the family of soft torus with the same basic properties, i.e., the field of C*-algebras {Bα}α ∈ [0,α0] is continuous and each Bα is a crossed product of a C*-algebra homotopically equivalent to C(S1) by Z. We then show that the K-groups of Bα are isomorphic to Z ⊕ Z. Applying results from the theory of rotation algebras we prove that every positive element (n,m) in K0(Bα) satisfies |m|α ≤ 2πn. It follows that these C*-algebras are not all homotopically equivalent to each other, although they have the same K-groups.
On Teichmüller Spaces of Koebe Groups
Authors: Gastesi Pablo Arés
Published: September 2003

In this paper we study the Teichmüller space of constructible Koebe groups. These are Kleinian groups arising from planar covering of 2-orbifolds. In the first part, we parametrize the Teichmüller spaces of Koebe groups using a technique that can be applied to explicitly compute generators of these groups, maybe by programming a computer. In the second part, we study some properties of these Teichmüller spaces. More precisely, we find the covering group of these spaces (the universal covering is the Teichmüller space of the punctured surface), and prove an isomorphism theorem similar to the Bers–Greenberg theorem for Fuchsian groups.
Crossings of Set-Partitions and Addition Crossings of Graded-Independent Random Variables
Authors: Mingo James A. , Nica Alexandru
Published: September 2003

We consider a q-deformation, introduced in [7], of the cumulants associated with a linear functional on polynomials; combinatorially, the deformation is defined using crossing numbers of set-partitions. The paper is concerned with the case q = -1. We show that if the linear functional μ : C[X] → C is symmetric (i.e.μ(Xn) = 0 for n odd), then the exponential generating function of the even (-1)-cumulants of μ is equal to [Formula: see text], (as a formal power series in z). We discuss the connection of this fact with the form of independence for (non-commutative) random variables which corresponds to the operation of Z2-graded tensor product.
Birational Models of the Moduli Spaces of Stable Vector Bundles Over Curves
Authors: Hu Yi , Li Wei-Ping
Published: September 2003

We give a method to construct stable vector bundles whose rank divides the degree over curves of genus bigger than one. The method complements the one given by Newstead. Finally, we make some systematic remarks and observations in connection with rationality of moduli spaces of stable vector bundles.
Vanishing Theorems and Eigenvalue Estimates in Riemannian Spin Geometry
Authors: Branson Thomas , Hijazi Oussama
Published: September 2003

We use the representation theory of the structure group Spin (n), together with the theory of conformally covariant differential operators, to generalize results estimating eigenvalues of the Dirac operator to other tensor-spinor bundles, and to get vanishing theorems for the kernels of first-order differential operators.
Pseudo Harmonic Morphisms
Authors: Loubeau E.
Published: September 2003

We study a geometrical condition (PHWC) which is weaker than horizontal weak conformality. In particular, we show that harmonic maps satisfying this condition, which will be called pseudo harmonic morphisms, include harmonic morphisms and can be described as pulling back certain germs to certain other germs. Finally, we construct a canonical f-structure associated to every map satisfying (PHWC) and find conditions on this f-structure to ensure the harmonicity of the map.
Compact Hopf *-Algebras, Quantum Enveloping Algebras and Dual Woronowicz Algebras for Quantum Lorentz Groups
Authors: Kurose Hideki , Nakagami Yoshiomi
Published: September 2003

A compact Hopf *-algebra is a compact quantum group in the sense of Koornwinder. There exists an injective functor from the category of compact Hopf *-algebras to the category of compact Woronowicz algebras. A definition of the quantum enveloping algebra Uq(sl(n,C)) is given. For quantum groups SUq(n) and SLq(n,C), the commutant of a canonical representation of the quantum enveloping algebra for q coincides with the commutant of the dual Woronowicz algebra for q-1.
Tangle Surgeries Which Preserve Jones-Type Polynomials
Authors: Hoste Jim , Przytycki Józef H.
Published: September 2003

Using an argument from statistical mechanics, V. Jones has given a new method for constructing pairs of links with identical skein polynomials. We give a more general construction and use it to provide a simple proof of a theorem of Traczyk's involving rotors of links. Several examples are given of pairs of knots with coincident skein polynomials and small crossing number.
C*-Algebraic Quantum Groups Arising from Algebraic Quantum Groups
Authors: Kustermans J. , van Daele A.
Published: September 2003

We associate to an algebraic quantum group a C*-algebraic quantum group and show that this C*-algebraic quantum group essentially satisfies an upcoming definition of Masuda, Nakagami and Woronowicz.
SIMPLE CURRENT EXTENSIONS AND MAPPING CLASS GROUP REPRESENTATIONS
Authors: BANTAY PETER
Published: September 2003

The conjecture of Fuchs, Schellekens and Schweigert on the relation of mapping class group representations and fixed point resolution in simple current extensions is investigated, and a cohomological interpretation of the untwisted stabilizer is given.
ESTIMATION OF UPWARD MUON ENERGY SPECTRA IN THE EARTH INDUCED BY DIFFUSE MUON NEUTRINOS EMITTED FROM THE ATMOSPHERIC, GALACTIC AND ACTIVE GALACTIC NUCLEAR SOURCES
Authors: MITRA MALA , BHATTACHARYYA D. P.
Published: September 2003

The energy spectra of upward muons in the Earth emitted by atmospheric, galactic and AGN diffuse muon neutrinos incident on the Earth have been estimated using the standard formulation developed by Gaisser based on charge–current interactions in rock along with the QED-based energy loss formulation. The derived primary-cosmic-nucleus–air interaction yield neutrino-induced muon spectrum in the vertical direction is in accord with the recent data available from MACRO, IMB, KAMIOKA and BAKSAN underground experiments for energies below 3 GeV. The TeV muon energy spectra initiated by atmospheric, galactic and AGN diffuse muon neutrinos of Stecker et al. and Szabo and Protheroe have also been estimated. The estimated atmospheric neutrino-induced muon fluxes at 0° and 89° above 2 TeV energy do not cross the observed upper limit detected by Meyer using the underground Frejus muon detector.
A NOTE ON THE PICARD–FUCHS EQUATIONS FOR N=2 SEIBERG–WITTEN THEORIES
Authors: ISIDRO JOSÉ M. , MUKHERJEE AVIJIT , NUNES JOÃO , SCHNITZER HOWARD J.
Published: September 2003

A concise presentation of the PF equations for N= 2 Seiberg–Witten theories for the classical groups of rank r with Nf massless hypermultiplets in the fundamental representation is provided. For Nf=0 all r PF equations can be given in a generic form. For certain cases with Nf≠0, not all equations are generic. However, in all cases there are at least r-2 generic PF equations. For these cases the classical part of the equations is generic, while the quantum part can be formulated using a method described in a previous paper by the authors, which is well suited to symbolic computer calculations.
HARMONIC SUPERPOSITIONS OF NONEXTREMAL p-BRANES
Authors: LAVRINENKO I. V. , POPE C. N. , TRAN T. A. , LÜ H.
Published: September 2003

The plot of allowed p and D values for p-brane solitons in D-dimensional supergravity is the same whether the solitons are extremal or nonextremal. One of the useful tools for relating different points on the plot is vertical dimensional reduction, which is possible if periodic arrays of p-brane solitons can be constructed. This is straightforward for extremal p-branes, since the no-force condition allows arbitrary multicenter solutions to be constructed in terms of a general harmonic function on the transverse space. This has also been shown to be possible in the special case of nonextremal black holes in D=4 arrayed along an axis. In this paper, we extend previous results to include multiscalar black holes, and dyonic black holes. We also consider their oxidation to higher dimensions, discuss general procedures for constructing the solutions and study their symmetries.
FLUCTUATIONS IN A PRIMORDIAL ANISOTROPIC ERA
Authors: NOVELLO MÁRIO , DE FREITAS LUCIANE R.
Published: September 2003

The primordial Universe is treated in terms of a nonperfect fluid configuration endowed with an anisotropic expansion. The deGennes–Landau mechanism of phase transition acts as a very efficient process to provide the elimination of the previous anisotropy and to set the universe in the current isotropic FRW stage. The entropy produced, as a consequence of the phase transition, depends on the strength of the previous shear. We suggest the hypothesis that the germinal perturbations that will grow into the observed system of galaxies occurring in the anisotropic era. We present a model to deal with this idea that provides a power spectrum of fluctuations of the form [Formula: see text]. We compare this prediction of our model to the current knowledge on the galaxy formation process.
SOFTLY BROKEN N=2 QCD WITH MASSIVE QUARK HYPERMULTIPLETS, I
Authors: ÁLVAREZ-GAUMÉ LUIS , MARIÑO MARCOS , ZAMORA FREDERIC
Published: September 2003

We present a general analysis of all possible soft breakings of N=2 supersymmetric QCD preserving the analytic properties of the Seiberg–Witten solutions for the SU(2) group with Nf=1,2,3 hypermultiplets. We obtain all the couplings of the spurion fields in terms of properties of the Seiberg–Witten periods which we express in terms of elementary elliptic functions by uniformizing the elliptic curves associated to each number of flavors. We analyze in detail the monodromy properties of the softly broken theory, and obtain them by a particular embedding into a pure gauge theory with a higher rank group. This allows us to write explicit expressions of the effective potential which are close to the exact answer for moderate values of the supersymmetry breaking parameters. The vacuum structures and phases of the broken theories will be analyzed in the forthcoming second part of this paper.
SUPERSPACE FORMULATION FOR THE BRST QUANTIZATION OF THE CHIRAL SCHWINGER MODEL
Authors: ABREU EVERTON M. C. , BRAGA NELSON R. F.
Published: September 2003

It has recently been shown that the field–antifield quantization of anomalous irreducible gauge theories with closed algebra can be represented in a BRST superspace where the quantum action at one loop order, including the Wess–Zumino term, and the anomalies show up as components of the same superfield. We show here how the Chiral Schwinger Model can be represented in this formulation.
UNIFIED OCTONIONIC REPRESENTATION OF THE 10–13 DIMENSIONAL CLIFFORD ALGEBRA
Authors: ABDEL-KHALEK KHALED
Published: September 2003

We give a one-dimensional octonionic representation of the different Clifford algebra Cliff(5,5)~Cliff(9,1), Cliff(6,6)~ Cliff(10,2) and lastly Cliff(7,6)~ Cliff(10,3) which can be given by 8×8 real matrices taking into account some suitable manipulation rules.
2D QUANTUM GRAVITY: THREE STATES OF SURFACES
Authors: FUJITSU A. , TSUDA N. , YUKAWA T
Published: September 2003

Two-dimensional random surfaces are studied numerically by the dynamical triangulation method. In order to generate various kinds of random surfaces, two higher derivative terms are added to the action. The structures of surfaces, two higher derivative terms are added to the action. The structures of surfaces in the two-dimensional parameter space are classified into three states: flat surface, crumpled surface and branched polymer. In addition, there exists a special point (pure gravity) corresponding to the universal fractal surface. A new probe to detect branched polymers is proposed by using the analysis of minimum neck baby universe. This method can clearly distinguish the branched polymer phase from others according to the sizes and arrangements of baby universes. The size and arrangement of baby universes change drastically for each state. The phases of surfaces coupled with multi-Ising spins are studied in a similar manner.
ON FIELD THEORIES WITH AN INFINITE NUMBER OF FIELDS
Authors: ITZHAKI N.
Published: September 2003

A toy model with an infinite number of interacting fermions in four-dimensional space–time is analyzed. We find that the model is finite at any order in perturbation theory. However, perturbation theory is valid only for external momenta smaller than [Formula: see text], where λ is the coupling constant.
ENERGY DISSIPATION OF HADRONIC INTERACTIONS WELL ABOVE COLLIDER ENERGIES VIEWED FROM FLY'S EYE DATA ON DEPTHS OF SHOWER MAXIMA
Authors: DING L. K. , JING C. L. , JING G. R. , REN J. L. , ZHU Q. Q. , DAI H. Y. , LOH E. C. , SOKOLSKY P. , SOMMERS P.
Published: September 2003

Using the depths of shower maxima, as measured by Fly's Eye experiment,we study the energy dissipation of hadronic showers resulting from cosmic interactions at energies between 3×1017 eV and 1019 eV. We place, based on Fly's Eye data, a set of constraints on the expected depths of shower maxima for proton-initiated showers, disentangling the hadronic interaction features from the cosmic ray composition. It is shown that in the energy region substantially above collider energies, only Monte Carlo simulations using hadronic interaction models characterized by a strong energy dissipation predict the depths of shower maxima that are consistent with this set of constraints. Between the two equally good fitsof the energy dependences of cross-section and multiplicity at collider energies — the power law and log-square law, we find that the cosmic ray data favor the power law above collider energies. The Feynman scaling in the fragmentation region above collider energies is valid only if the cross-section for inelastic hadron–air–nucleus interactions increases much more rapidly than the trend established at accelerator energies. The multiple nucleon interaction picture appears to be plausible for hadron–nucleus interactions.
SCALAR DEFORMATIONS OF SCHWARZSCHILD HOLES AND THEIR STABILITY
Authors: DENNHARDT HELGE , LECHTENFELD OLAF
Published: September 2003

We construct two solutions of the minimally coupled Einstein-scalar field equations, representing regular deformations of Schwarzschild black holes by a self-interacting, static, scalar field. One solution features an exponentially decaying scalar field and a triple-well interaction potential; the other one is completely analytic and sprouts Coulomb-like scalar hair. Both evade the no-hair theorem by having partially negative potential, in conflict with the dominant energy condition. The linear perturbation theory around such backgrounds is developed in general, and yields stability criteria in terms of effective potentials for an analog Schrödinger problem. We can test for more than half of the perturbation modes, and our solutions prove to be stable against those.
WARD IDENTITY FOR NONLOCAL QED
Authors: RAJE BHAGEERATHI P. C. , EAPEN KURUVILLA
Published: September 2003

Evens et al.1 have given a gauge-invariant regularization scheme for QED which they have named nonlocal regularization. The present authors2 have worked out the QED vertex part in this scheme of regularization. In this paper we present a Ward identity for nonlocal QED to the order of two loops (order e4). In the limit of QED (Λ→∞), this identity reduces to the usual form of the Ward identity.
UNITARITY OF THE AHARONOV–BOHM SCATTERING AMPLITUDES
Authors: ARAI MASATO , MINAKATA HISAKAZU
Published: September 2003

We discuss the unitarity relation of the Aharonov–Bohm scattering amplitude with the hope that it distinguishes between the differing treatment which employ different incident waves. We find that the original Aharonov–Bohm scattering amplitude satisfies the unitarity relation under the regularization prescription whose theoretical foundation does not appear to be understood. On the other land, the amplitude obtained by Ruijsenaars who uses plane wave as incident wave also satisfies the unitarity relation but in an unusual way.
ANOMALOUS DEFECTS AND THEIR QUANTIZED TRANSVERSE CONDUCTIVITIES
Authors: BALACHANDRAN A. P. , JOHN VARGHESE , MOMEN ARSHAD , MORAES FERNANDO
Published: September 2003

Using a description of defects in solids in terms of three-dimensional gravity, we study the propagation of electrons in the background of disclinations and screw dislocations. We study the situations where there are bound states that are effectively localized on the defect and hence can be described in terms of an effective (1+1)-dimensional field theory for the low energy excitations. In the case of screw dislocations, we find that these excitations are chiral and can be described by an effective field theory of chiral fermions. Fermions of both chirality occur even for a given direction of the magnetic field. The "net" chirality of the system however is not always the same for a given direction of the magnetic field, but changes from one sign of the chirality through zero to the other sign as the Fermi momentum or the magnitude of the magnetic flux is varied. On coupling to an external electromagnetic field, the latter becomes anomalous and predicts novels conduction properties for these material.
FINITE SIZE SCALING AND RUNNING COUPLING CONSTANT IN CPN-1 MODELS
Authors: MANFREDINI EMANUELE
Published: September 2003

In this work I present a numerical study of the Finite Size Scaling (FSS) of a correlation length in the framework of the CPN-1 model by means of the 1/N expansion. This study has been thought as preparatory to the application of FSS to the measure on the lattice of a new coupling constant fx(1/R), defined in terms or rectangular Wilson loops. I give also a perturbative expansion of fx(1/R) in powers of the corresponding coupling constant in the [Formula: see text] scheme together with some preliminary numerical results obtained from the Polyakov ratio and I point out the conceptual problems that limit this approach.
PERTURBATIVE DYNAMICS OF FRACTIONAL STRINGS ON MULTIPLY WOUND D-STRINGS
Authors: HASHIMOTO AKIKAZU
Published: September 2003

Fractional strings in the spectrum of states of open strings attached to a multiply wound D-brane is explained. We first describe the fractional string states in the low energy effective theory where the topology of multiple winding is encoded in the gauge holonomy. The holonomy induces twisted boundary conditions responsible for the fractional moding of these states. We also describe fractional strings in world sheet formulation and compute simple scattering amplitudes for Hawking emission/absorption. Generalization to fractional DN-strings in a one-brane five-brane bound state is described. When a one-brane and a five-brane wraps Q1 and Q5 times respectively around a circle, the momentum of DN-strings is quantized in units of 2π/LQ1Q5. These fractional states appear naturally in the perturbative spectrum of the theory.