bluuebunny/crossref_metadata_2025 huggingface dataset:
A 1300 K furnace forin situX-ray microtomography
Authors: Bellet D. , Gorges B. , Dallery A. , Bernard P. , Pereiro E. , Baruchel J.
Published: March 2003

A furnace covering the temperature range from 298 to 1300 K has been designed and constructed to studyin situthe structural evolution of materials by using synchrotron X-ray microtomography. The furnace has cylindrical symmetry, compatible with the required 180° rotation, small dimensions and low absorption. It can also be used for other scattering methods, such as diffraction.
A procedure for setting up high-throughput nanolitre crystallization experiments. II. Crystallization results
Authors: Brown J. , Walter T. S. , Carter L. , Abrescia N. G. A. , Aricescu A. R. , Batuwangala T. D. , Bird L. E. , Brown N. , Chamberlain P. P. , Davis S. J. , Dubinina E. , Endicott J. , Fennelly J. A. , Gilbert R. J. C. , Harkiolaki M. , Hon W.-C. , Kimberley F. , Love C. A. , Mancini E. J. , Manso-Sancho R. , Nichols C. E. , Robinson R. A. , Sutton G. C. , Schueller N. , Sleeman M. C. , Stewart-Jones G. B. , Vuong M. , Welburn J. , Zhang Z. , Stammers D. K. , Owens R. J. , Jones E. Y. , Harlos K. , Stuart D. I.
Published: March 2003

An initial tranche of results from day-to-day use of a robotic system for setting up 100 nl-scale vapour-diffusion sitting-drop protein crystallizations has been surveyed. The database of over 50 unrelated samples represents a snapshot of projects currently at the stage of crystallization trials in Oxford research groups and as such encompasses a broad range of proteins. The results indicate that the nanolitre-scale methodology consistently identifies more crystallization conditions than traditional hand-pipetting-style methods; however, in a number of cases successful scale-up is then problematic. Crystals grown in the initial 100 nl-scale drops have in the majority of cases allowed useful characterization of X-ray diffraction, either in-house or at synchrotron beamlines. For a significant number of projects, full X-ray diffraction data sets have been collected to 3 Å resolution or better (either in-house or at the synchrotron) from crystals grown at the 100 nl scale. To date, five structures have been determined by molecular replacement directly from such data and a further three from scale-up of conditions established at the nanolitre scale.
Relationship marketing can mitigate product and service failures
Authors: Priluck Randi
Published: March 2003

Relationship marketing is beneficial to firms because it can foster customer loyalty and re‐patronage behavior. Consumers engaged in relational exchanges are more satisfied than those in discrete transactions because of the ease and psychological comfort of purchasing from a familiar company. This research investigates the power of relationship marketing to mitigate in two situations. One exposes consumers to poor product performance and examines their levels of trust, commitment and satisfaction. The second presents a product failure that is followed by a lapse in service recovery and measures satisfaction and exit behavior. The findings of both studies suggest that relationships make up for increasingly strong negative encounters, providing a level of insulation for the marketer. Implications for service firms are discussed.
Intellectual capital and the capital market – organisation and competence
Authors: Holland John
Published: March 2003

This paper explores the organisation of the information market and its ability to process intellectual capital information for capital markets. Discusses also incentives for market participants to create and use information on the role of intellectual capital (IC) in corporate value creation, and the capability of the market for information to process and use such information in the stock market valuation of companies. Particular attention is paid to corporate disclosure of, and fund manager use of, such information. The analysis also extends the idea of a knowledge‐intensive value creation process to fund managers and analysts. Problems within corporate, fund manager, and analysts knowledge‐intensive value creation chains are considered to be a source of barriers to the creation and use of corporate IC information in markets. Further research on these chains and barriers is required to improve the flow of IC information into stock prices.
Are ISO 15489‐1:2001 and ISAD(G) compatible? Part 1
Authors: Shepherd Elizabeth , West Victoria
Published: March 2003

Part 1 of this article presents a provisional set of metadata elements for the implementation of ISO 15489‐1:2001 Information and Documentation – Records Management. In Part 2 the elements are mapped to the General International Standard Archival Description (2nd edition, 2000) (ISAD(G)) to establish the extent to which the two standards are compatible and the degree to which ISO 15489‐1 metadata can be transferred directly from a current records management system to an archival description system. Metadata systematically captured during the current life of the record and transferred to an archive with the record should simplify the process of archival description and prevent the loss of context. The mapping reveals a large degree of correlation between the metadata that should be captured as part of a records management system to satisfy ISO 15489‐1, and the information required to compile an ISAD(G) compliant archival description. Most of the compatible information comes from the Description Area of ISO 15489‐1 metadata elements rather than the management area. Five out of the six mandatory elements for ISAD(G) interoperability, i.e. reference code, title, dates, extent and creator, are present in the ISO 15489‐1 metadata element set, albeit often in an abbreviated form. This is encouraging and perhaps not very surprising, since senior records and archives professionals were involved in the drafting of both standards.
Assessing the effectiveness of shopping mall promotions: customer analysis
Authors: Parsons Andrew G.
Published: March 2003

Common promotional activities employed by shopping mall marketers were ranked by a sample of customers on their likelihood of encouraging increases in the two key performance indicators used by shopping malls – sales and visits. Results suggest clear distinctions between sales drivers and visit drivers and show possible combinations that would be effective in generating optimum customer behaviour. Some traditional promotions (fashion shows and product displays) are shown to be poor performers in generating either response, whilst school/community displays appear to be encouraging non‐customer visits. Whilst mall‐wide sales are the preferred promotion, a combination of general entertainment and price‐based promotions are found to be a strong alternative way to encourage visits and spending. Actual sales, visits, and promotional types for a three‐month period were analysed to assess the degree to which customers’ behaviour matched stated behaviour likelihood, with supportive results.
COMMON MULTIPLES OF COMPLETE GRAPHS
Authors: BRYANT DARRYN , MAENHAUT BARBARA
Published: March 2003

A graph $H$ is said to divide a graph $G$ if there exists a set $S$ of subgraphs of $G$, all isomorphic to $H$, such that the edge set of $G$ is partitioned by the edge sets of the subgraphs in $S$. Thus, a graph $G$ is a common multiple of two graphs if each of the two graphs divides $G$.

This paper considers common multiples of a complete graph of order $m$ and a complete graph of order $n$. The complete graph of order $n$ is denoted $K_n$. In particular, for all positive integers $n$, the set of integers $q$ for which there exists a common multiple of $K_3$ and $K_n$ having precisely $q$ edges is determined.

It is shown that there exists a common multiple of $K_3$ and $K_n$ having $q$ edges if and only if $q \equiv 0 \, ({\rm mod}\, 3)$, $q \equiv 0 \, ({\rm mod}\, \binom n2)$ and

(1) $q \neq 3 \binom n2$ when $n \equiv 5 \, ({\rm mod}\, 6)$;

(2) $q \geq (n + 1) \binom n2$ when $n$ is even;

(3) $q \notin \{36, 42, 48\}$ when $n = 4$.

The proof of this result uses a variety of techniques including the use of Johnson graphs, Skolem and Langford sequences, and equitable partial Steiner triple systems.

2000 Mathematical Subject Classification: 05C70, 05B30, 05B07.
A STRENGTHENING OF RESOLUTION OF SINGULARITIES IN CHARACTERISTIC ZERO
Authors: BRAVO A. , VILLAMAYOR U. O.
Published: March 2003

Let $X$ be a closed subscheme embedded in a scheme $W$, smooth over a field ${\bf k}$ of characteristic zero, and let ${\mathcal I} (X)$ be the sheaf of ideals defining $X$. Assume that the set of regular points of $X$ is dense in $X$. We prove that there exists a proper, birational morphism, $\pi : W_r \longrightarrow W$, obtained as a composition of monoidal transformations, so that if $X_r \subset W_r$ denotes the strict transform of $X \subset W$ then:

(1) the morphism $\pi : W_r \longrightarrow W$ is an embedded desingularization of $X$ (as in Hironaka's Theorem);

(2) the total transform of ${\mathcal I} (X)$ in ${\mathcal O}_{W_r}$ factors as a product of an invertible sheaf of ideals ${\mathcal L}$ supported on the exceptional locus, and the sheaf of ideals defining the strict transform of $X$ (that is, ${\mathcal I}(X){\mathcal O}_{W_r} = {\mathcal L} \cdot {\mathcal I}(X_r)$).

Thus (2) asserts that we can obtain, in a simple manner, the equations defining the desingularization of $X$.

2000 Mathematical Subject Classification: 14E15.
MARKED SCHOTTKY GROUPS AND REPRESENTATIONS OF SURFACE GROUPS
Authors: BUTTON J. O.
Published: March 2003

We give a complete condition for any $n$ elements of ${\rm PSL}(2, {\mathbb R})$ to generate a Fuchsian group which is a Schottky group on that set of generators, and apply it to a question of Bowditch on representations of surface groups into ${\rm PSL}(2, {\mathbb R})$.

2000 Mathematical Subject Classification: 20H10, 32G15.
NORMALIZERS OF OPERATOR ALGEBRAS AND REFLEXIVITY
Authors: KATAVOLOS A. , TODOROV I. G.
Published: March 2003

The set of normalizers between von Neumann (or, more generally, reflexive)
algebras $\mathcal{A}$ and $\mathcal{B}$ (that is, the set of all operators $T$ such that
$T \mathcal{A} T^{\ast} \subseteq \mathcal{B}$ and $T^{\ast} \mathcal{B} T \subseteq \mathcal{A}$) possesses
‘local linear structure’: it is a union of reflexive linear spaces. These spaces belong to the
interesting class of normalizing linear spaces, namely, those linear spaces $\mathcal{U}$ of
operators satisfying $\mathcal{UU}^{\ast} \mathcal{U} \subseteq \mathcal{U}$ (also known as ternary rings
of operators). Such a space is reflexive whenever it is ultraweakly closed, and then it is of the
form $\mathcal{U} = \{T : TL = \phi (L) T$ for all $L \in \mathcal{L}\}$ where $\mathcal{L}$ is a set of
projections and $\phi$ a certain map defined on $\mathcal{L}$. A normalizing space consists of normalizers
between appropriate von Neumann algebras $\mathcal{A}$ and $\mathcal{B}$. Necessary and sufficient conditions
are found for a normalizing space to consist of normalizers between two reflexive algebras. Normalizing
spaces which are bimodules over maximal abelian self-adjoint algebras consist of operators
‘supported’ on sets of the form $[f = g]$ where $f$ and $g$ are appropriate Borel functions.
They also satisfy spectral synthesis in the sense of Arveson.

2000 Mathematical Subject Classification: 47L05 (primary), 47L35, 46L10 (secondary).
MORITA EQUIVALENT PRINCIPAL 3-BLOCKS OF THE CHEVALLEY GROUPS G2(q)
Authors: USAMI YOKO , NAKABAYASHI MIYAKO
Published: March 2003

The principal 3-block of a Chevalley group $G_2(q)$ with $q$ a power of 2 satisfying $q \equiv 2$ or 5 mod 9 and the principal 3-block of $G_2(2)$ are Morita equivalent.

2000 Mathematical Subject Classification: 20C05, 20C20, 20C33.
SINGULARITIES OF HYPERBOLIC GAUSS MAPS
Authors: IZUMIYA SHYUICHI , PEI DONGHE , SANO TAKASI
Published: March 2003

In this paper we adopt the hyperboloid in Minkowski space as the model of hyperbolic space. We define the hyperbolic Gauss map and the hyperbolic Gauss indicatrix of a hypersurface in hyperbolic space. The hyperbolic Gauss map has been introduced by Ch. Epstein [J. Reine Angew. Math. 372 (1986) 96–135] in the Poincaré ball model, which is very useful for the study of constant mean curvature surfaces. However, it is very hard to perform the calculation because it has an intrinsic form. Here, we give an extrinsic definition and we study the singularities. In the study of the singularities of the hyperbolic Gauss map (indicatrix), we find that the hyperbolic Gauss indicatrix is much easier to calculate. We introduce the notion of hyperbolic Gauss–Kronecker curvature whose zero sets correspond to the singular set of the hyperbolic Gauss map (indicatrix). We also develop a local differential geometry of hypersurfaces concerning their contact with hyperhorospheres.

2000 Mathematical Subject Classification: 53A25, 53A05, 58C27.
LOGARITHMIC ORBIFOLD EULER NUMBERS OF SURFACES WITH APPLICATIONS
Authors: LANGER ADRIAN
Published: March 2003

We introduce orbifold Euler numbers for normal surfaces with boundary $\mathbb{Q}$-divisors. These numbers behave multiplicatively under finite maps and in the log canonical case we prove that they satisfy the Bogomolov–Miyaoka–Yau type inequality. Existence of such a generalization was earlier conjectured by G. Megyesi [Proc. London Math. Soc. (3) 78 (1999) 241–282]. Most of the paper is devoted to properties of local orbifold Euler numbers and to their computation.

As a first application we show that our results imply a generalized version of R. Holzapfel's ‘proportionality theorem’ [Ball and surface arithmetics, Aspects of Mathematics E29 (Vieweg, Braunschweig, 1998)]. Then we show a simple proof of a necessary condition for the logarithmic comparison theorem which recovers an earlier result by F. Calderón-Moreno, F. Castro-Jiménez, D. Mond and L. Narváez-Macarro [Comment. Math. Helv. 77 (2002) 24–38].

Then we prove effective versions of Bogomolov's result on boundedness of rational curves in some surfaces of general type (conjectured by G. Tian [Springer Lecture Notes in Mathematics 1646 (1996) 143–185)]. Finally, we give some applications to singularities of plane curves; for example, we improve F. Hirzebruch's bound on the maximal number of cusps of a plane curve.

2000 Mathematical Subject Classification: 14J17, 14J29, 14C17.
ECONOMICAL COVERS WITH GEOMETRIC APPLICATIONS
Authors: ALON NOGA , BOLLOBÁS BÉLA , KIM JEONG HAN , VU VAN H.
Published: March 2003

A cover of a hypergraph is a collection of edges whose union contains all vertices. Let $H = (V, E)$ be a $k$-uniform, $D$-regular hypergraph on $n$ vertices, in which no two vertices are contained in more than $o(D / e^{2k} \log D)$ edges as $D$ tends to infinity. Our results include the fact that if $k = o(\log D)$, then there is a cover of $(1 + o(1)) n / k$ edges, extending the known result that this holds for fixed $k$. On the other hand, if $k \geq 4 \log D $ then there are $k$-uniform, $D$-regular hypergraphs on $n$ vertices in which no two vertices are contained in more than one edge, and yet the smallest cover has at least $\Omega (\frac {n}{k} \log (\frac {k}{\log D} ))$ edges. Several extensions and variants are also obtained, as well as the following geometric application. The minimum number of lines required to separate $n$ random points in the unit square is, almost surely, $\Theta (n^{2/3} / (\log n)^{1/3}).$

2000 Mathematical Subject Classification: 05C65, 05D15, 60D05.
MACKEY FORMULA IN TYPE A (Proc. London Math. Soc. (3) 80 (2000) 545–574)
Authors: Bonnafé Cédric
Published: March 2003

The statement (and the proof) of Theorem 4.1.1 of the paper ‘Mackey formula in type A’ [Proc. London. Math. Soc. (3) 80 (2000) 545–574] is false. In this corrigendum we provide a correct statement (and a correct proof). As a consequence, we see that Corollary 4.1.2 of the paper holds. So all the other statements in the paper are correct (up to minor misprints…).

2000 Mathematical Subject Classification: 20G05, 20G40.
Red Cell Pulmonary Transit Times Through the Healthy Human Lung
Authors: Zavorsky G. S. , Walley K. R. , Russell J. A.
Published: March 2003

It has previously been postulated that rapid red cell capillary transit through the human lung plays a role in the mechanism of diffusion limitation in some endurance athletes. Methodological limitations currently prevent researchers from directly measuring pulmonary capillary transit times in humans during exercise; however, first pass radionuclide cardiography allows direct measurement of red blood cell (RBC) transit times through the whole lung at various exercise intensities. We examined the relationship between mean whole lung red cell pulmonary transit times (cardiopulmonary transit times or CPTT) and different levels of flow in 88 healthy humans (76 males, 12 females) from several studies (mean age 31 years). The pooled data suggest that the relationship between CPTT and cardiac index (CI), beginning at rest and progressing through to maximum exercise demonstrates that CPTT reaches its minimum value when CI is about 8.1 l m2 min−1 (2.5‐3 times the CI value at rest), and does not significantly change with further increases in CI. Cardiopulmonary blood volume (CPBV) index also does not change significantly until CI reaches 2.5 to 3 times the CI value at rest and then increases roughly linearly after that point. Consequently, the systematic increase in CPBV index with increasing pulmonary blood flow between 8.1 and 20 l m2 min−1 displays an adaptive response of the cardiopulmonary system by augmenting CPBV (and perhaps pulmonary capillary blood volume through distension and recruitment) to offset the reduction in CPTT, as no significant difference in mean CPTT is observed between these levels of flow (P > 0.05). Therefore, these data demonstrate that CPBV does not reach maximum capacity during strenuous or maximum exercise. This does not support the principle of quarter‐power allometric scaling for flow when explaining modifications during exercise. Therefore, we speculate that the observed relationships between CPTT, CBPV index and flow may prevent mean CPTT (and perhaps mean pulmonary capillary transit times) from decreasing below the threshold time required for oxygenation.
Effect of Brain Serotoninergic Stimulation on Sodium Appetite of Euthyroid and Hypothyroid Rats
Authors: Badauê‐Passos D. , Ventura R. R. , Silva L. F. S. , Olivares E. L. , Reis L. C.
Published: March 2003

The aim of the present work was to investigate the role of the serotoninergic system in the control of sodium appetite of hypothyroid rats (HTR) by administering drugs that affect the serotoninergic activity, and to compare the same homeostatic behaviour in euthyroid rats (ETR) also given these drugs. Fenfluramine (FEN; 5.0 mg kg−1, I.P.), which releases serotonin in the brain, significantly reduced the intake of 1.8% NaCl in HTR subjected to water and sodium depletion (depleted) or water, sodium and food deprivation (deprived) by 31 and 45%, respectively, 120 min after FEN injection, compared to HTR that received vehicle alone. Similarly, administration of FEN to ETR reduced 1.8% NaCl intake in depleted and deprived rats by 64 and 46%, respectively. The presynaptic serotonin reuptake inhibitor fluoxetine (20.0 mg kg−1, I.P.) led to the inhibition of sodium appetite in HTR during the initial 30 min in depleted rats and for up to 60 min post‐injection in deprived rats, while sodium appetite inhibition persisted for longer periods in ETR. The 5HT2C receptor agonist mCPP (5.0 mg kg−1, I.P.) caused a drastic reduction in sodium appetite in HTR and ETR in depleted and deprived rats, respectively, after 120 min. Prior administration of the 5HT2C receptor antagonist LY53857 (5.0 mg kg−1, I.P.) completely blocked the inhibitory action of mCPP on sodium appetite in both HTR and ETR. In summary, our results suggest that the recruitment of serotoninergic neurons involved in the modulation of sodium appetite seems to be decreased in hypothyroidism due to a probable deficiency in the cerebral signalling pathway.
Interactions Between Neural and Hormonal Mediators of Renal Vascular Tone in Anaesthetized Rabbits
Authors: Guild Sarah‐Jane , Barrett Carolyn J. , Evans Roger G. , Malpas Simon C.
Published: March 2003

We investigated how sympathetic nerve activity and vasoactive hormones interact in controlling renal haemodynamics in pentobarbitone‐anaesthetized rabbits. Renal blood flow was progressively reduced by electrical stimulation (0.5‐3 Hz) of the renal nerves, during renal arterial infusion of saline, vasoconstrictors (angiotensin II and [Phe2,Ile3,Orn8]‐vasopressin), or vasodilators (acetylcholine, adrenomedullin and the nitric oxide donor methylamine hexamethylene NONOate (MAHMA NONOate). A frequency‐rich stimulus was also applied to test whether the vasoactive agents affect the dynamic control of renal blood flow by sympathetic nerve activity. The vasodilators tended to increase renal blood flow, but only the effect of MAHMA NONOate was statistically significant. [Phe2,Ile3,Orn8]‐vasopressin reduced medullary perfusion (by 61 ± 12%) but not renal blood flow or cortical perfusion. Angiotensin II reduced renal blood flow (33 ± 3%) and cortical perfusion (14 ± 5%) but not medullary perfusion. Steady‐state responses of renal blood flow and cortical perfusion during renal nerve stimulation were attenuated during infusion of acetylcholine and [Phe2,Ile3,Orn8]‐vasopressin, while angiotensin II attenuated responses of medullary perfusion, and MAHMA NONOate and adrenomedullin had no significant effects. The dynamic response to sympathetic nerve activity (renal blood flow responded as a low pass filter with a pure time delay of ∼664 ms) was not altered by the vasoactive agents. We conclude that some vasoactive agents can modulate steady‐state renal haemodynamic responses to sympathetic nerve activity in a regionally specific manner, independent of their effects on baseline renovascular tone. However, they have little impact on the dynamic response of renal blood flow to sympathetic nerve activity.
Keratinocyte Growth Factor and Epidermal Growth Factor Can Reverse the Intestinal Atrophy Associated with Elemental Diets in Mice
Authors: Sasaki Masaya , FitzGerald Anthony J. , Mandir Nikki , Berlanga‐Acosta Jorge , Goodlad Robert A.
Published: March 2003

Elemental diets are associated with intestinal atrophy and reduced intestinal integrity. Growth factors such as keratinocyte growth factor (KGF) and epidermal growth factor (EGF) have considerable potential for the therapeutic reversal of such atrophy and may have greater actions if given in combination. We examined the effects of recombinant human KGF (rHuKGF), EGF and their combination on tissue mass, cell proliferation and crypt fission throughout the intestine of mice fed elemental diets. rHuKGF significantly increased the relative wet weight of the intestine, with EGF having a lesser effect. Cell proliferation of the stomach, small intestine and colon were significantly increased by rHuKGF, but EGF only increased proliferation in the small intestine. Crypt fission in the small intestine and colon was significantly decreased by rHuKGF. An interactive effect of rHuKGF and EGF on the weight of stomach and the proliferation of the fundus and antrum was observed. Moreover, an interactive effect of the agents was also seen on crypt fission in the colon. We concluded that (1) rHuKGF and EGF have significant trophic effects on the stomach, small intestine and colon, (2) these actions vary between different sites in the gastrointestinal tract, and (3) interactive effects occur.
Cerebral Metabolism is Influenced by Muscle Ischaemia During Exercise in Humans
Authors: Dalsgaard Mads K. , Nybo Lars , Cai Yan , Secher Niels H.
Published: March 2003

Maximal exercise reduces the cerebral metabolic ratio (O2/(glucose + 1/2lactate)) to < 4 from a resting value close to 6, and only part of this decrease is explained by the ‘intent’ to exercise. This study evaluated whether sensory stimulation of brain by muscle ischaemia would reduce the cerebral metabolic ratio. In 10 healthy human subjects the cerebral arterial‐venous differences (a‐v differences) for O2, glucose and lactate were assessed before, during and after three bouts of 10 min cycling with equal workload: (1) control exercise at light intensity, (2) exercise that elicited a high rating of perceived exertion due to a 100 mmHg thigh cuff, and (3) exercise followed by 5 min of post‐exercise muscle ischaemia that increased blood pressure by ∼ 20%. Control exercise did not significantly affect the a‐v differences. However, during the recovery from exercise with thigh cuffs the cerebral metabolic ratio decreased from a resting value of 5.4 ± 0.2 to 4.0 ± 0.4 (mean ±s.e.m.. P < 0.05) as a discrete lactate efflux from the brain at rest shifted to a slight uptake. Also, following post‐exercise muscle ischaemia, the cerebral metabolic ratio decreased to 4.5 ± 0.3 (P < 0.05). The results support the hypothesis that during exercise, cerebral metabolism is influenced both by the mental effort to exercise and by sensory input from skeletal muscles.
G Protein‐Coupled Receptor Kinases 2 and 5 are Differentially Expressed in Rat Skeletal Muscle and Remain Unchanged Following β2‐Agonist Administration
Authors: Jones Simon W. , Baker David J. , Greenhaff Paul L.
Published: March 2003

Chronic stimulation of β2‐receptors with β2‐agonists causes desensitisation, which in skeletal muscle is accompanied by myosin heavy chain (MHC) remodelling, similar to that observed in heart failure patients. However, the mechanisms for this skeletal muscle remodelling are not well established. G protein‐coupled receptor kinases (GRKs) specifically phosphorylate and desensitise G protein‐coupled receptors during periods of agonist activation. However, desensitisation associated with prolonged agonist activation alters β‐adrenergic signalling, and downstream affects gene expression. We hypothesised that skeletal muscle remodelling induced by β2‐agonist administration could be regulated by GRK expression. Therefore the aim of this study was firstly to characterise which, if any, of the six known isoforms of GRK were expressed in skeletal muscle and then secondly to determine whether remodelled skeletal muscle induced by chronic β2‐agonist administration was accompanied by altered expression of GRK isoforms. Male Wistar rats were administered a β2‐agonist daily for 8 weeks, and the expression of MHC and GRKs examined in gastrocnemius and soleus muscles. Treatment with β2‐agonist caused a change in MHC in soleus from types I to IIA, and in gastrocnemius from MHC types IIA/IIX to IIB. Western blotting revealed that GRK2 and GRK5 were expressed in skeletal muscle. Furthermore, despite changes in MHC and differential muscle‐specific expression of GRK isoforms, there was no significant change in expression of GRK2 and GRK5 in soleus or gastrocnemius following β2‐agonist administration. In conclusion the level of GRK expression is unlikely to be responsible for MHC switching following chronic β2‐receptor stimulation.
Effects of Endotoxin Exposure on Cationic Amino Acid Transporter Function in Ovine Peripheral Blood Mononuclear Cells
Authors: Clark Megan F. , Reade Michael C. , Boyd C. A. R. , Young J. Duncan
Published: March 2003

Rodent models of sepsis differ from clinical human disease in that humans make substantially less whole‐body nitric oxide and have different cellular responses to endotoxin. Sheep, when exposed to endotoxin, behave in a manner more similar to humans. Many studies of rodent peripheral blood mononuclear cells (PBMCs) exposed to endotoxin demonstrate increased cationic amino acid transporter function (particularly through the y+ transporter) to supply arginine substrate to upregulated nitric oxide synthase. Whether this is true in sheep is not known. We have studied cationic amino acid transport in sheep PBMCs stimulated with endotoxin, using labelled lysine. PBMCs stimulated both in vitro and in vivo show an initial reduction in total and y+ lysine transport (after 1‐2 h exposure to endotoxin): a previously undescribed effect of endotoxin. In in vitro activated cells, the reduction in y+ transport was prevented by the lipoxygenase inhibitor, nordihydroguaretic acid (NDGA), and the phospholipase inhibitor 4‐bromophenacyl bromide (4‐BPAB), but not cyclohexamide or a number of other inhibitors of intracellular second‐messenger pathways. In contrast after 14 h incubation, the expected increase in total and y+ lysine transport was seen. The increase in y+ transport could be prevented by cyclohexamide, dexamethasone, ibuprofen, the protein kinase C inhibitor sphingosine, NDGA and 4‐BPAB. These results suggest that in response to endotoxin exposure there is an initial decrease in y+ activity mediated by a lipoxygenase product, followed by a substantial increase in y+ activity mediated by the products of either cyclo‐oxygenase or lipoxygenase. Cyclo‐oxygenase and/or lipoxygenase inhibition might be useful in reducing arginine transport, and hence nitric oxide production, in these cells.
Static Fusimotor Action During Locomotion in the Decerebrated Cat Revealed by Cross‐Correlation of Spindle Afferent Activity
Authors: Taylor R. Durbaba A. , Rawlinson S. R. , Ellaway P. H.
Published: March 2003

Cross‐correlation of the discharges of muscle spindle afferents in ankle extensor and flexor muscles has been used to reveal the activity of static gamma (γS) motoneurones innervating chain intrafusal muscle fibres during locomotion. In the anaesthetised cat, the cross‐correlation of spindle afferents, jointly innervated by a γS‐efferent with chain fibre contacts, showed short duration synchrony (2‐8 ms) when the efferent was stimulated repetitively. In pre‐mammillary decerebrated cats, the cross‐correlograms of discharges of some pairs of spindle afferents showed similar short duration peaks of synchronisation and these were interpreted as being due to a common γS drive to chain intrafusal muscle fibres. The incidence of synchrony was low, and was similar at rest (5% of pairs) and during treadmill locomotion (7% of pairs). Phase dependence of synchrony was evident during locomotion in the flexor muscle. The synchrony of muscle spindle afferent discharge is discussed in relation to estimates of the numbers of spindles contacted by individual γS‐efferents.
Book Review
Authors: Ellaway P.H.
Published: March 2003

Degeneration and Regeneration in the Nervous System Edited by N. R. Saunders and K. M. Dziegielewska Foreword by John Nicholls
Chronic Blockade of Neuronal Nitric Oxide Synthase Does Not Affect Long‐Term Control of Blood Pressure in Normal, Saline‐Drinking or Deoxycorticosterone‐Treated Rats
Authors: Wangensteen Rosemary , Sainz Juan , Rodríguez‐Gomez Isabel , Moreno Juan Manuel , Osuna Antonio , Vargas Félix
Published: March 2003

It has been reported that long‐term selective inhibition of neuronal nitric oxide synthase (nNOS) produces elevated blood pressure (BP) in normal rats. The present study was designed to analyse the possible influences of the sodium‐retaining hormone deoxycorticosterone acetate (DOCA) and of an increased sodium intake on BP effects induced by the chronic blockade of nNOS with 7‐nitroindazole (7NI). Two experiments were performed using 7NI at a dose of either 10 mg kg−1 day−1 (experiment 1) or 30 mg kg−1 day−1 (experiment 2). The following groups were used in both experiments: control rats, and rats that received either 1% saline drinking water (Salt), deoxycorticosterone acetate (DOCA), 7NI, 7NI plus 1% saline (7NI + Salt) or 7NI plus DOCA (7NI + DOCA). The tail systolic BP (SBP) was measured in all rats once a week. At the end of the experimental period, the mean arterial pressure (MAP) and metabolic, morphological and renal variables were measured. There were no significant differences in the tail SBP, final MAP or glomerular filtration rate between the experimental groups and the control group. In both experiments, the plasma renin activity (PRA) was significantly inhibited in the Salt groups and suppressed in the DOCA groups. The PRA significantly increased in the 7NI groups, whereas the 7NI + Salt and 7NI + DOCA groups showed a significant inhibition in PRA, especially compared to the 7NI groups in the two experiments. We conclude that chronic nNOS blockade is unable to increase BP in normal, saline‐drinking or DOCA‐treated rats. Furthermore, the nNOS blockade does not interfere with the counterbalance between renin and an increased sodium intake or retention.
The Effect of Isoprenaline Infusion on Renal Renin and Angiotensinogen Gene Expression in the Anaesthetised Rat
Authors: Moosavi S. Mostafa Shid , Johns Edward J.
Published: March 2003

In this study, we investigated the ability of acute infusions of isoprenaline to alter renin and angiotensinogen gene expression in the kidney of rats anaesthetised with chloralose‐urethane. Groups of rats received I.V. infusions of either saline or the β‐adrenoceptor agonist isoprenaline at 400 ng kg−1 min−1 for 4 h. The isoprenaline infusion caused a sustained decrease in mean blood pressure of approximately 20 mmHg (P < 0.01), an increase in heart rate of 50 beats min−1 (P < 0.01) and reductions in urine flow and sodium excretion of 80‐90% (both P < 0.01). Renal blood flow and glomerular filtration rate were transiently reduced by 21% (P < 0.01) and 61% (P < 0.001), respectively, in the first hour, recovering to baseline levels after 4 h of infusion. At the end of the study, plasma renin activity was raised approximately 6‐fold (P < 0.01) while renal renin and angiotensinogen mRNA levels were 1.8‐ and 1.5‐fold higher (both P < 0.05) compared to the control group (saline infusion). The isoprenaline‐induced renin secretion could have been mediated via the activation of β‐adrenoceptors resulting in the exocytosis of renin‐containing granules, with a smaller contribution being due to reduced renal haemodynamics. The increase in renal renin gene expression in response to isoprenaline was probably due primarily to the intracellular signalling processes acting directly on nuclear mechanisms. Similarly, the increased renal angiotensinogen gene expression most probably reflected a direct action of the isoprenaline. These findings provide evidence that catecholamines are involved in mechanisms that rapidly alter the expression of the genes of the renin‐angiotensin system within the kidney.
Hyperglycaemia Inhibits Thymidine Incorporation and Cell Growth via Protein Kinase C, Mitogen‐Activated Protein Kinases and Nitric Oxide in Human Umbilical Vein Endothelium
Authors: Rojas Susana , Rojas Romina , Lamperti Liliana , Casanello Paola , Sobrevia Luis
Published: March 2003

An elevated extracellular concentration of D‐glucose (i.e. hyperglycaemia) inhibits cell proliferation and incorporation of the endogenous nucleoside thymidine into DNA in human umbilical vein endothelial cells (HUVECs). Cells in their log‐phase of growth (3.7 ± 0.3 days, n = 27) incubated for 30 min with 25 mM D‐glucose, but not with equimolar concentrations of L‐glucose or D‐mannitol, exhibited reduced [3H]thymidine incorporation and cell growth rate, with no change in cell viability (> 98%), total DNA, protein content or cell volume. Incubation with D‐glucose activated protein kinase C (PKC), endothelial NO synthase (eNOS), p42 and p44 mitogen‐activated protein kinases (p42/44mapk), but inhibited superoxide dismutase (SOD). Incubation with D‐glucose also increased cGMP and cAMP levels. The effect of D‐glucose was blocked by the PKC inhibitor calphostin C, the MAP kinase kinase 1/2 (MEK1/2) inhibitor PD‐98059, the eNOS inhibitor L‐NAME, the protein kinase G (PKG) inhibitor KT‐5823 and the protein kinase A (PKA) inhibitor KT‐5720. In the presence of 5 mM D‐glucose, [3H]thymidine incorporation and cell growth were reduced by the PKC activator phorbol 12‐myristate 13‐acetate (PMA), the NO donor S‐nitroso‐N‐acetyl‐L,D‐penicillamine (SNAP), dibutyryl cGMP, dibutyryl cAMP and the Ca2+ ionophore A‐23187. The effect of A‐23187 was blocked by calphostin C and PD‐98059. D‐Glucose‐dependent inhibition of thymidine incorporation and cell proliferation is associated with increased PKC, eNOS, and MEK1/2, but decreased SOD activity, and higher intracellular levels of cGMP, cAMP and Ca2+ in HUVECs. These are cellular mechanisms which may reduce endothelial cell growth in pathological conditions such as in diabetes mellitus or hyperglycaemia.
Apoptosis‐Dependent Acute Lung Injury and Repair After Intratracheal Instillation of Noradrenaline in Rats
Authors: Uhal Bruce D. , Rayford Heather , Zhuang Jiaju , Li Xiaopeng , Laukka Jeremy , Soledad‐Conrad Valerie
Published: March 2003

Earlier work in this laboratory showed that noradrenaline (NA) induces apoptosis in primary cultures of alveolar epithelial cells (AECs). Apoptosis of alveolar epithelial cells may promote the collapse of lung barrier function. On this basis we hypothesized that exogenous NA, administered by intratracheal (I.T.) instillation, might induce AEC apoptosis in vivo followed by acute lung injury. Delivery of NA (10 μM) I.T. into male Wistar rats increased labelling of both fragmented DNA, measured by in situ end labelling (ISEL), and the active form of caspase 3 (anti‐Casp3) 6 and 20 h after administration (P < 0.05), but instillation of the vehicle alone (PBS) had no effect. Both ISEL and anti‐Casp3 labelling were attenuated by concurrent I.T. delivery of the broad‐spectrum caspase inhibitor ZVADfmk. After 6 h, most ISEL‐ and Casp3‐positive cells were located in the surfaces of alveolar walls, but after 20 h more were found in alveolar spaces (P < 0.05). Instillation of NA also increased the bronchoalveolar lavage (BAL) content of fluorescent albumin (BODIPY‐alb), which had previously been injected intravenously; the increase was reversed by concurrent ZVADfmk administration. These data suggest that NA‐induced apoptosis of AECs in vivo is sufficient to invoke transient collapse of AEC barrier function that is rapidly repaired.
Stability Analysis of a Hydrodynamic Journal Bearing With Rotating Herringbone Grooves
Authors: Jang G. H. , Yoon J. W.
Published: March 2003

This paper presents an analytical method to investigate the stability of a hydrodynamic journal bearing with rotating herringbone grooves. The dynamic coefficients of the hydrodynamic journal bearing are calculated using the FEM and the perturbation method. The linear equations of motion can be represented as a parametrically excited system because the dynamic coefficients have time-varying components due to the rotating grooves, even in the steady state. Their solution can be assumed as a Fourier series expansion so that the equations of motion can be rewritten as simultaneous algebraic equations with respect to the Fourier coefficients. Then, stability can be determined by solving Hill’s infinite determinant of these algebraic equations. The validity of this research is proved by the comparison of the stability chart with the time response of the whirl radius obtained from the equations of motion. This research shows that the instability of the hydrodynamic journal bearing with rotating herringbone grooves increases with increasing eccentricity and with decreasing groove number, which play the major roles in increasing the average and variation of stiffness coefficients, respectively. It also shows that a high rotational speed is another source of instability by increasing the stiffness coefficients without changing the damping coefficients.
Quantitative Mechanism of Significant Benefits of Underfill in Flip-Chip Assemblies
Authors: Cai Xia , Chen Liu , Zhang Qun , Xu Bulu , Huang Weidong , Xie Xiaoming , Cheng Zhaonian
Published: March 2003

The thermal fatigue failure of SnPb solder joints of flip chip on board with and without underfill for two types of flip-chip packages was investigated by conducting thermal cycling test, scanning acoustic microscopy observation, and cross section inspection. The corresponding 3-D finite element simulation was performed to analyze the effects of underfill on thermomechanical behavior. The viscoelasticity of underfill and the viscoplasticity of solder were considered in the 3-D simulations. The Coffin-Manson equation with material constants C=5.54,β=−1.38 was fitted from the combination of the lifetime measured and the shear plastic strain range simulated by 3-D model. In the case with underfill, the plastic strain of every solder joint becomes very similar and little dependent on the position of solder joints. The modeled axial strain distribution coincided well with the distribution of microstructure coarsening visible in cross sections. The mismatch of thermal expansion resulted in an overall warpage of the assembly for the case with underfill, which decreased the shear deformation of the solder joints and increased the interface stress on the chip. The interface stress distribution from the 3-D simulation agreed very well with the experimental observations.
Laryngeal biomechanics and vocal communication in the squirrel monkey (Saimiri boliviensis)
Authors: Brown Charles H. , Alipour Fariborz , Berry David A. , Montequin Douglas
Published: March 2003

The larynges of eight squirrel monkeys were harvested, dissected, mounted on a pseudotracheal tube, and phonated using compressed air. Patterns of vocal fold oscillation were compared with sound spectrograms of calls recorded from monkeys in our colony. Four different regimes of vocal fold activation were identified. Regime 1 resembled typical human vowel production, with regular vocal-fold vibration, a prominent fundamental frequency, and an accompanying series of harmonic overtones. This regime is likely to give rise to squirrel monkey “cackles,” as well as a variety of other harmonically structured calls. In regime 2, the pattern of vibrations exhibited the presence of two or more unrelated frequencies (biphonation). This regime of glottal activity resembled the biphonation observed in many exemplars of “twitter” and “kecker” calls. The vocal folds oscillated continuously in regime 3, but produced glottal pulses whose amplitudes waxed and waned rhythmically. This phenomenon resulted in the percept of a series of discrete pulses, and may give rise to “errs,” “churrs,” and other calls composed of a rapid sequence of acoustic elements. In regime 4, the period of each oscillation was quasi-irregular. Shrieks and other broadband calls or call elements that lack an apparent fundamental frequency may be produced in this manner.
Traction-free vibrations of finite trigonal elastic cylinders
Authors: Heyliger Paul R. , Johnson Ward L.
Published: March 2003

The unrestrained, traction-free vibrations of finite elastic cylinders with trigonal material symmetry are studied using two approaches, based on the Ritz method, which formulate the weak form of the equations of motion in cylindrical and rectangular coordinates. Elements of group theory are used to divide approximation functions into orthogonal subsets, thus reducing the size of the computational problem and classifying the general symmetries of the vibrational modes. Results for the special case of an isotropic cylinder are presented and compared with values published by other researchers. For the isotropic case, the relative accuracy of the formulations in cylindrical and rectangular coordinates can be evaluated, because exact analytical solutions are known for the torsional modes. The calculation in cylindrical coordinates is found to be more accurate for a given number of terms in the series approximation functions. For a representative trigonal material, langatate, calculations of the resonant frequencies and the sensitivity of the frequencies on each of the elastic constants are presented. The dependence on geometry (ratio of length to diameter) is briefly explored. The special case of a transversely isotropic cylinder (with the elastic stiffness C14 equal to zero) is also considered.
Acoustic streaming measurements in annular thermoacoustic engines
Authors: Job Stéphane , Gusev Vitalyi , Lotton Pierrick , Bruneau Michel
Published: March 2003

Experiments with an annular thermoacoustic engine employing quasiadiabatic interaction between traveling acoustic waves and an inhomogeneously heated porous material indicate the presence of a closed-loop mass flux. A qualitative modeling of the enthalpy flux in the thermoacoustic core provides an opportunity to estimate the thermal convection associated with this mass flux, by using temperature measurement at different positions in the system. The estimated acoustically induced mass flux is in accordance with recent theoretical results.
Modulation masking in cochlear implant listeners: envelope versus tonotopic components
Authors: Chatterjee Monita
Published: March 2003

It is hypothesized that channel-interaction in cochlear implant listeners as measured in a modulation-masking experiment would be influenced by both the tonotopic overlap between masker and signal as well as an interaction between their envelopes. Two experiments were conducted to measure the effects of maskers with noisy and steady-state envelopes on modulation detection by four adult Nucleus-22 cochlear implant listeners, as a function of tonotopic distance between the masker and the signal. In the first experiment, we measured detection thresholds for a 50-Hz modulation in the envelope of a 500-Hz carrier pulse train, in the presence of a masker stimulating regions basal and apical to, as well as overlapping with, the signal. The maskers had two kinds of envelopes: (i) amplitude-modulated by flat-spectrum noise (NAM) and (ii) steady-state (SSpeak) at a level corresponding to the maximum of the noise fluctuation range. In general, modulation thresholds obtained in the presence of the NAM maskers significantly exceeded thresholds obtained with the corresponding SSpeak maskers. The ratio ρ of the threshold modulation depth m obtained with the NAM masker to that obtained with the SSpeak masker was defined as a conservative index of “envelope masking.” In the second experiment, ρ was determined for two different tasks: the detection of modulation at 20 Hz and steady-state intensity increment detection. Compared to the 50-Hz modulation detection results, the ratio ρ was reduced for the 20-Hz modulation detection task and even more so for the steady-state increment detection task. It is concluded that channel-interaction can be significantly increased in cochlear implant listeners when dynamic stimuli are used in place of steady-state stimuli.
Helmholtz resonator with extended neck
Authors: Selamet Ahmet , Lee Iljae
Published: March 2003

Acoustic performance of a concentric circular Helmholtz resonator with an extended neck is investigated theoretically, numerically, and experimentally. The effect of length and shape of, and the perforations on the neck extension is examined on the resonance frequency and the transmission loss. A two-dimensional analytical method is developed for an extended neck with constant cross-sectional area, while a three-dimensional boundary element method is applied for the variable area and perforated extension. Lumped and one-dimensional approaches are also included to illustrate the effect of the higher order modes. For a piston-driven model, predicted resonance frequencies using lumped, one-dimensional, and two-dimensional analytical methods are compared with those from multidimensional boundary element method. Analytical and computational transmission loss predictions for pipe-mounted model are compared to the experimental data obtained from an impedance tube setup. It is shown that the resonance frequency may be controlled by the length, shape, and perforation porosity of the extended neck without changing the cavity volume.