bluuebunny/crossref_metadata_2025 huggingface dataset:
Redefining the tonotopic core of rat auditory cortex: Physiological evidence for a posterior field
Authors: Doron Neot N. , Ledoux Joseph E. , Semple Malcolm N.
Published: October 2002

Previous physiological studies have identified a tonotopically organized primary auditory cortical field (AI) in the rat. Some of this prior research suggests that the rat, like other mammals, may have additional fields surrounding AI. We, therefore, recorded in the Sprague‐Dawley rat extracellular responses of single neurons throughout AI, and continued posteriorly to verify the existence of a posterior field (P) and to compare the neuronal properties in the two regions. Acoustic stimuli, including tones, bandpass noise, broadband noise, and temporally modulated stimuli, were delivered dichotically via sealed systems. Consistent with previous findings, AI was characterized by an anterior‐to‐posterior tonotopic progression from high to low frequencies (ranging from >40 kHz to <1 kHz). A frequency reversal at the posterior border of AI marked entry into a second core tonotopic region, P, with progressively higher frequencies encountered further posteriorly, up to a point (approximately 8 kHz) where cells were no longer tone responsive. Nevertheless, bandpass noise was an effective stimulus in P, enabling characterization of cells up to 15 kHz. Compared with AI, the frequency tuning of response areas was relatively broader in P, the response latency was often longer and more variable, and the response magnitude was more commonly a nonmonotonic function of stimulus level. In both fields, most neurons were binaurally influenced. The presence of multiple auditory cortical fields in the rat is consistent with auditory cortical organization in other mammals. Moreover, the response properties of P relative to AI in the rat also resemble those found in other mammals. Finally, the physiological data suggest that core auditory cortex (temporal area TE1) is composed not only of AI as previously thought, but also of at least two other subdivisions, P and an anterior field (A). Furthermore, our physiological characterization of TE1 reveals that it is larger than suggested by previous anatomical characterizations. J. Comp. Neurol. 453:345–360, 2002. © 2002 Wiley‐Liss, Inc.
Roles of estrogen receptor α and androgen receptor in the regulation of neuronal nitric oxide synthase
Authors: Scordalakes Elka M. , Shetty Savera J. , Rissman Emilie F.
Published: October 2002

In brain and peripheral tissues, steroid hormones regulate nitric oxide synthase (nNOS). We asked whether estrogen receptor‐α (ERα) and/or androgen receptor (AR) regulated nNOS immunoreactivity in mouse brain. First, we quantified cells singly labeled for nNOS immunoreactivity or labeled dually with ERα‐immunoreactive (‐ir) or AR‐ir cells in the nucleus accumbens (Acb), preoptic area (POA), bed nucleus of the stria terminalis (BNST), posterior dorsal and posterior ventral regions of the medial amygdala (MePD and MePV, respectively), and paraventricular nucleus (PVN). The POA and MePD contained the greatest number of double‐labeled cells. More nNOS‐ir cells were colabeled with ERα immunoreactivity compared with AR immunoreactivity. Next, by using a double mutant mouse in which males lacked functional ERα, AR, or both, we investigated the roles of these steroid receptors in nNOS‐ir cell numbers and immunoreactive area staining under testosterone (T) and estradiol (E2) conditions. Our data show that functional ERα is correlated with more nNOS‐ir cells under T conditions and more immunoreactive area staining in the POA under both T and E2 conditions. However, ERα decreases nNOS‐ir cell number in the BNST under E2 treatment. In summary, the data suggest that AR has organizational actions on nNOS‐ir cell numbers in the MePV, that interactions between ERα and AR genes occur in PVN, and that sex differences in nNOS‐ir area staining are limited to the POA. Thus, we show that ERα and AR interact to regulate nNOS in male and female brain in a site‐specific manner. J. Comp. Neurol. 453:336–344, 2002. © 2002 Wiley‐Liss, Inc.
Changes in grain size of sand in transport over a foredune
Authors: Arens S. M. , van Boxel J. H. , Abuodha J. O. Z.
Published: October 2002

Suspended sand is sampled at several heights and positions on a beach and foredune, providing detailed insight into the vertical and horizontal variation in sand content in the air during landward transport. Grain‐size analysis is used to study the changes in grain‐size distribution during landward transport. Mean grain size and sorting decrease during transport. Changes in textural parameters follow a gradual and regular path when the sediment is transported into the foredune. Sediment trapped on the seaward slope at a height of 30–50 cm above the surface closely resembles the sediment trapped landward, which implies that changes in the direction of transport are related to vertical changes within the sediment transport profiles. The movement of sand over the vegetated foredunes is induced by turbulent forces created by the air flowing across the vegetation and the foredune, leading to a change from saltation on the beach to modified saltation and suspension on the foredune. Small grains are lifted higher and fall more slowly than coarse grains and therefore are transported further landward, resulting in a gradual decrease in grain size of the landward‐deposited sediment. Copyright © 2002 John Wiley & Sons, Ltd.
The role of the soil moisture balance in the unsaturated zone on movement and stability of the Beline landslide, France
Authors: Bogaard T. A. , van Asch T. W. J.
Published: October 2002

The aim of this paper is to analyse the role of the unsaturated zone in groundwater recharge in a landslide and the effect of land use change on its stability. This is studied on the basis of the Beline landslide situated near Salins‐les‐Bains (Jura, France). The unsaturated zone was modelled using the Hydrus‐1D model. Model calibration was based on soil moisture time series using an inverse modelling approach. The unsaturated zone model accurately modelled the soil moisture content time series in 1996 and 1997.

The groundwater model was capable of modelling both the average groundwater level and the amplitude of the groundwater level fluctuation, but failed to model the dynamics and the precise timing of the fluctuations.

The influence of changes in potential evapotranspiration was studied by changing this input parameter by 10 to 20 per cent as both an increase and decrease. The effects of these changes were quite large. Since the hydrological model chain was able to predict peak groundwater levels quite well, these peak levels were used to calculate maximum moving velocities of the landslide for different evapotranspiration scenarios. The simulations show that a decrease in evapotranspiration up to 20 per cent results in a 20‐fold increase in maximum velocity. An increase in evapotranspiration (10 to 20 per cent) will probably stabilize the landslide for most of the time. Copyright © 2002 John Wiley & Sons, Ltd.
Estimation and testing of ARFIMA models in the real exchange rate
Authors: Gil‐Alana L.A. , Toro J.
Published: October 2002

The Purchasing Power Parity (PPP) hypothesis is one of the most important theoretical relationships in international economics. However, its empirical support remains controversial. We propose an alternative way of modelling the real exchange rate in five industrialized countries in relation to the US dollar, by means of fractionally integrated ARIMA models (i.e. ARFIMA). This approach allows us to capture the low‐frequency dynamics relevant for examination of the long‐run parity. A crucial fact when estimating with parametric approaches is that the model must be correctly specified, otherwise the estimates are likely to be inconsistent. In fact, misspecification of the short‐run components of the series can invalidate the estimation of its long‐run behaviour. We propose a model selection criterion based on LR tests on nested parametric hypotheses along with other several likelihood‐based criteria. As a validation method of the specified model, we suggest the use of Robinson's (1994) tests. Our empirical results indicate that the PPP might hold as a long‐run proposition. Copyright © 2002 John Wiley & Sons, Ltd.
Fragile graphs with small independent cuts
Authors: Chen Guantao , Faudree Ralph J. , Jacobson Michael S.
Published: October 2002

A graph is called fragile if it has a vertex cut which is also an independent set. Chen and Yu proved that every graph with n vertices and at most 2n−4 edges is fragile, which was conjectured to be true by Caro. However, their proof does not give any information on the number of vertices in the independent cuts. The purpose of this paper is to investigate when a graph has a small independent cut. We show that if G is a graph on n vertices and at most (12n/7)−3 edges, then G contains an independent cut S with ∣S∣≤3. Upper bounds on the number of edges of a graph having an independent cut of size 1 or 2 are also obtained. We also show that for any positive integer k, there is a positive number ε such that there are infinitely many graphs G with n vertices and at most (2−ε)n edges, but G has no independent cut with less than k vertices. © 2002 Wiley Periodicals, Inc. J Graph Theory 41: 327–341, 2002
On evaluation of product dropping damage
Authors: Wang Zhi‐Wei
Published: October 2002

As an extension of the classical damage boundary curve in the case of product dropping shock, the concept of a dropping damage boundary curve for linear and non‐linear packaging system to evaluate the dropping damage of product is developed in this paper. The dropping damage boundary curves are given for linear and hyperbolic tangent packaging systems with different damping. For a linear packaging system the dropping damage of a product is determined only by the natural frequency of the corresponding packaging system without damping and the dropping shock velocity of package except the system damping, and they compose the basic evaluation quantities of product dropping damage. For a non‐linear hyperbolic tangent packaging system, the system parameter and the dimensionless dropping shock velocity are two basic quantities in the evaluation of product dropping damage. It should be emphasized that the dimensionless dropping shock velocity is related not only to the dropping height of package box but also to the system parameter integration. This is the important feature differentiating a non‐linear packaging system from a linear one. The influence of system damping on the dropping damage boundary curves is also discussed. This concept and the results have important value in the design of cushioning packaging. Copyright © 2002 John Wiley & Sons, Ltd.
Inhibition of microbial growth in bread through active packaging
Authors: Soares N. F. F. , Rutishauser D. M. , Melo N. , Cruz R. S. , Andrade N. J.
Published: October 2002

Baked products lose quality by loss of moisture, staling and mould growth. The objective of this study was to determine the possibility of reducing mould growth during bread storage through interaction with active packaging film. Cellulose acetate films containing 0%, 2% and 4% sodium propionate were prepared. Three slices of bread were piled, sandwiched with the prepared film pieces, packed in low‐density polyethylene bags and stored for 15 days at 25 ± 2°C. Treatment with no film between the slices of bread served as a control. The microbiological analyses showed that increased propionate concentration into the film decreased mould growth during the storage period. Bread stored with no film showed a lower mould count compared with bread in contact with film without sodium propionate, which may be due to absence of air between the slices resulting from closeness of the bread slices. The water activity, pH and moisture content showed small variations during the storage period. Copyright © 2002 John Wiley & Sons, Ltd.
A unified approach to the analysis of Horton‐Strahler parameters of binary tree structures
Authors: Nebel Markus E.
Published: October 2002

The Horton‐Strahler number naturally arose from problems in various fields, e.g., geology, molecular biology and computer science. Consequently, detailed investigations of related parameters for different classes of binary tree structures are of interest. This paper shows one possibility of how to perform a mathematical analysis for parameters related to the Horton‐Strahler number in a unified way such that only a single analysis is needed to obtain results for many different classes of trees. The method is explained by the examples of the expected Horton‐Strahler number and the related rth moments, the average number of critical nodes, and the expected distance between critical nodes. © 2002 Wiley Periodicals, Inc. Random Struct. Alg., 21: 252–277, 2002
On the asymmetry of random regular graphs and random graphs
Authors: Kim Jeong Han , Sudakov Benny , Vu Van H.
Published: October 2002

This paper studies the symmetry of random regular graphs and random graphs. Our main result shows that for all 3 ≤ d ≤ n − 4 the random d‐regular graph on n vertices almost surely has no nontrivial automorphisms. This answers an open question of N. Wormald [13]. © 2002 Wiley Periodicals, Inc. Random Struct. Alg., 21: 216–224, 2002
Distributed algorithms with dynamical random transitions
Authors: Guillotin‐Plantard Nadine , Schott René
Published: October 2002

We analyze a model of exhaustion of shared resources where allocation and deallocation requests are modeled by dynamical random variables as follows: Let (E, 𝒜, μ, T) be a dynamical system where( E, 𝒜, μ) is a probability space and T is a transformation defined on E. Let d ≥ 1 and f1, … , fd be functions defined on E with values in [0, \documentclass{article}\pagestyle{empty}\begin{document}${1\over d}$\end{document}]. Let (Xi)i≥1 be a sequence of independent random vectors with values in ℤd. Let x ∈ E and (ej)1≤j≤d be the unit coordinate vectors of ℤd. For every i ≥ 1, the law of the random vector Xi is given by

We write

for the ℤd‐random walk generated by the family (Xi)i≥1. When T is a rotation on the torus then explicit calculations are possible. This stochastic model is a (small) step towards the analysis of distributed algorithms when allocation and deallocation requests are time dependent. It subsumes the models of colliding stacks and of exhaustion of shared memory considered in the literature [14, 15, 11, 16, 17, 20] The technique is applicable to other stochastically modeled resource allocation protocols such as option pricing in financial markets and dam management problems. © 2002 Wiley Periodicals, Inc. Random Struct. Alg., 21: 371–396, 2002
A perspective factorization method for Euclidean reconstruction with uncalibrated cameras
Authors: Han Mei , Kanade Takeo
Published: October 2002

Structure from motion (SFM), which is recovering camera motion and scene structure from image sequences, has various applications, such as scene modelling, robot navigation, object recognition and virtual reality. Most of previous research on SFM requires the use of intrinsically calibrated cameras. In this paper we describe a factorization‐based method to recover Euclidean structure from multiple perspective views with uncalibrated cameras. The method first performs a projective reconstruction using a bilinear factorization algorithm, and then converts the projective solution to a Euclidean one by enforcing metric constraints. The process of updating a projective solution to a full metric one is referred as normalization in most factorization‐based SFM methods. We present three normalization algorithms which enforce Euclidean constraints on camera calibration parameters to recover the scene structure and the camera calibration simultaneously, assuming zero skew cameras. The first two algorithms are linear, one for dealing with the case that only the focal lengths are unknown, and another for the case that the focal lengths and the constant principal point are unknown. The third algorithm is bilinear, dealing with the case that the focal lengths, the principal points and the aspect ratios are all unknown. The results of experiments are presented. Copyright © 2002 John Wiley & Sons, Ltd.
Dynamics of plasma membrane microdomains and cross‐talk to the insulin signalling cascade
Authors: Müller Günter
Published: October 2002

The critical role of the heterogeneous nature of cellular plasma membranes in transmembrane signal transduction has become increasingly appreciated during the past decade. Areas of relatively disordered, loosely packed phospholipids are disrupted by hydrophobic detergent/carbonate‐insoluble glycolipid‐enriched raft microdomains (DIGs) of highly ordered (glyco)sphingolipids and cholesterol. DIGs exhibit low buoyant density and are often enriched in glycosylphosphatidylinositol‐anchored plasma membrane proteins (GPI proteins), dually acylated signalling proteins, such as non‐receptor tyrosine kinases (NRTKs), and caveolin. At least two types of DIGs, hcDIGs and lcDIGs, can be discriminated on basis of igher and ower content, respectively, of these typical DIGs components. In quiescent differentiated cells, GPI proteins and NRTKs are mainly associated with hcDIGs, however, in adipose cells certain insulin‐mimetic stimuli trigger redistribution of subsets of GPI proteins and NRTKs from hcDIGs to lcDIGs. Presumably, these stimuli induce displacement of GPI proteins from a GPI receptor located at hcDIGs whereas simultaneously NRTKs dissociate from a complex with caveolin located at hcDIGs, too. NRTKs are thereby activated and, in turn, modulate intracellular signalling pathways, such as stimulation of metabolic insulin signalling in insulin‐sensitive cells. The apparent dynamics of DIGs may provide a target mechanism for regulating the activity of lipid‐modified signalling proteins by small drug molecules, as exemplified by the sulfonylurea, glimepiride, which lowers blood glucose in an insulin‐independent fashion, in part.
Multiple roles of pleckstrin homology domains in phospholipase Cβ function
Authors: Philip Finly , Guo Yuanjian , Scarlata Suzanne
Published: October 2002

Since their discovery almost 10 years ago pleckstrin homology (PH) domains have been identified in a wide variety of proteins. Here, we focus on two proteins whose PH domains play a defined functional role, phospholipase C (PLC)‐β2 and PLCδ1. While the PH domains of both proteins are responsible for membrane targeting, their specificity of membrane binding drastically differs. However, in both these proteins the PH domains work to modulate the activity of their catalytic core upon interaction with either phosphoinositol lipids or G protein activators. These observations show that these PH domains are not simply binding sites tethered onto their host enzyme but are intimately associated with their catalytic core. This property may be true for other PH domains.
Current thoughts on the phosphatidylinositol transfer protein family
Authors: Allen-Baume Victoria , Ségui Bruno , Cockcroft Shamshad
Published: October 2002

Monomeric transport of lipids is carried out by a class of proteins that can shield a lipid from the aqueous environment by binding the lipid in a hydrophobic cavity. One such group of proteins is the phosphatidylinositol transfer proteins (PITP) that can bind phosphatidylinositol and phosphatidylcholine and transfer them from one membrane compartment to another. PITPs are found in both unicellular and multicellular organisms but not bacteria. In mice and humans, the PITP domain responsible for lipid transfer is found in five proteins, which can be classified into two classes based on sequence. Class I PITPs comprises two family members, α and β, small 35 kDa proteins with a single PITP domain which are ubiquitously expressed. Class IIA PITPs (RdgBαI and II) are larger proteins possessing additional domains that target the protein to membranes and are only able to bind lipids but not mediate transfer. Finally, Class IIB PITP (RdgBβ) is similar to Class I in size (38 kDa) and is also ubiquitously expressed. Class III PITPs, exemplified by the Sec14p family, are found in yeast and plants but are unrelated in sequence and structure to Class I and Class II PITPs. In this review we discuss whether PITP proteins are passive transporters or are regulated proteins that are able to couple their transport and binding properties to specific biological functions including inositol lipid signalling and membrane turnover.
Sphingomyelinases: enzymology and membrane activity
Authors: Goñi Félix M , Alonso Alicia
Published: October 2002

This paper reviews our present knowledge of sphingomyelinases as enzymes, and as enzymes acting on a membrane constituent lipid, sphingomyelin. Six types of sphingomyelinases are considered, namely acidic, secretory, Mg2+‐dependent neutral, Mg2+‐independent neutral, alkaline, and bacterial enzymes with both phospholipase C and sphingomyelinase activity. Sphingomyelinase assay methods and specific inhibitors are reviewed. Kinetic and mechanistic studies are summarized, a kinetic model and a general‐base catalytic mechanism are proposed. Sphingomyelinase–membrane interactions are considered from the point of view of the influence of lipids on the enzyme activity. Moreover, effects of sphingomyelinase activity on membrane architecture (increased membrane permeability, membrane aggregation and fusion) are described. Finally, a number of open questions on the above topics are enunciated.
The role of phosphatidic acid in the regulation of the Ras/MEK/Erk signaling cascade
Authors: Andresen Bradley T , Rizzo Mark A , Shome Kuntala , Romero Guillermo
Published: October 2002

Phosphatidic acid (PA) is an important second messenger produced by the activation of numerous cell surface receptors. Recent data have suggested that PA regulates multiple cellular processes. This review addresses primarily the role of PA in the regulation of the Erk1/2 cascade pathway. A model for the regulation of Erk1/2 phosphorylation by cell surface receptors is presented. According to this model, agonists stimulate the binding of GTP to Ras and the activation of phospholipase D to generate phosphatidic acid. PA promotes the binding of cRaf‐1 kinase to the membrane, where it interacts with Ras.GTP and other regulatory components of the pathway. Ras–Raf complexes remain bound to the surface of endosomes, where scaffolding complexes involving Ras, cRaf‐1, MEK and Erk are formed. Complete activation and coupling of the cascade requires endocytosis, a process that is also modulated by PA.
Smoking as a risk factor for preinvasive and invasive cervical lesions in female sex workers in Venezuela
Authors: Núñez J.T. , Delgado M. , Pino G. , Girón H. , Bolet B.
Published: October 2002

Objectives: To determine whether the number of cigarettes smoked per day and years of smoking were risk factors for preinvasive and invasive cervical lesions in Venezuelan female sex workers. Methods: The clinical history of 438 female sex workers (FSWs) was taken and each received a gynecological examination, a Pap smear, and a colposcopic examination. A colposcopically‐guided cervical biopsy was taken when the epithelium appeared abnormal. Results: The FSWs’ mean age was 32.16±8 years. Age at first sexual intercourse was 15.9±2 years, parity was 4.1±2.3, live births were 3±3, and age at first delivery was 16.6±4.7 years. Cervical biopsies were performed in 84 FSWs. Sixty‐four of them (76.2%) had preinvasive or invasive lesions and 47 (73.4%) were current smokers (Relative Risk) (RR), 1.26; 95% confidence interval (CI), 1.02–1.55; P<0.03]. FSWs who smoked more than 20 cigarettes per day had an increased RR to get a premalignant or malignant cervical lesion (RR, 1.27; 95% CI, 1.02–1.52; P<0.03). There was no statistically significant difference between FSWs who smoked 20 cigarettes or more per day and FSWs who smoked less than 20 cigarettes per day (RR, 1.36; 95% CI, 0.81–2.29; P<0.25). FSWs who had been smoking for 5 years or more were at risk to develop preinvasive or invasive cervical lesions (RR, 1.37; 95% CI, 1.01–1.86; P<0.04). Conclusions: The risk for FSWs to develop preinvasive or invasive cervical lesions increased with the number of cigarettes they smoked per day and their years of smoking.
Selective joint denervation promotes knee osteoarthritis in the aging rat
Authors: Salo Paul T. , Hogervorst Tom , Seerattan Ruth A. , Rucker Diana , Bray Robert C.
Published: October 2002

Osteoarthritis is the most common joint disorder with aging, but its cause is unknown. Mice lose joint afferents with aging, and this loss precedes development of osteoarthritis. We hypothesized a loss of joint afferents is involved in the pathogenesis of osteoarthritis.

To test this hypothesis, we denervated knee joints of 16 rats at age 2 months, by intra‐articular injection of an immunotoxin. The immunotoxin killed neurons after retrograde axonal transport to the cell body. At 16 or 24 months follow‐up, each joint was histologically assessed and assigned an osteoarthritis score.

At follow‐up, the number of joint afferents had spontaneously decreased by 42% in control knees and 69% in denervated knees. We found that control knees developed osteoarthritic changes with aging. However, denervated knees had far more severe changes, as evidenced by a 54% higher average osteoarthritis score than control knees (p = 0.0016, both groups 16 knees).

These results suggest a loss of afferents predisposes a joint to osteoarthritis. We propose the spontaneous loss of neurons with aging may be a normal developmental process. To explain the mechanism causing osteoarthritis, we suggest denervation permits aberrant joint loading, either by disturbing neuromuscular joint control, or by inducing joint laxity after neurogenic loss of tissue homeostasis.

© 2002 Orthopaedic Research Society. Published by Elsevier Science Ltd. All rights reserved.
Rheology of joint fluid in total knee arthroplasty patients
Authors: Mazzucco Dan , McKinley Gareth , Scott Richard D. , Spector Myron
Published: October 2002

While the properties of joint fluid may affect the tribology of joint replacement prostheses, the flow parameters of joint fluid have not yet been examined in the context of total knee arthroplasty (TKA). The objective of this study was to evaluate the flow properties of joint fluids in patients undergoing index TKA or revision TKA. We hypothesized that an alteration of the properties of joint fluid would result from TKA. The steady‐shear viscosity and storage and loss moduli were evaluated in joint fluid from 35 arthritis patients undergoing TKA, 14 patients undergoing revision of a previous TKA, and two patients presenting with joint effusion after TKA. The same properties were also evaluated in two commercially available sodium hyaluronate preparations and bovine serum, which is used as a lubricant in joint simulators. The steady‐shear viscosity varied over three orders of magnitude among samples obtained from patients undergoing TKA, spanning previously established “normal” and “diseased” ranges. Fluid obtained at index TKA was more likely to exhibit normal viscous properties than fluid obtained at revision TKA (p = 0.01). Other viscous parameters distinguished the two groups, but the difference did not reach statistical significance. Both groups exhibited degenerate flow properties when compared to synovial fluid from healthy individuals. Further examination of the connection between flow properties and the tribology of joint replacement prostheses is warranted.

© 2002 Orthopaedic Research Society. Published by Elsevier Science Ltd. All rights reserved.
Excessive degradation of type II collagen in articular cartilage in equine osteochondrosis
Authors: Laverty S. , O'Kouneff S. , Ionescu M. , Reiner A. , Pidoux I. , Webber C. , Rossier Y. , Billinghurst R. C. , Poole A. R.
Published: October 2002

Articular osteochondrosis (OCD) occurs in both man and animals. The etiology remains to be determined. Studies of OCD lesions in animals may provide clues as to its pathogenesis. The aim of our study was to determine whether there was evidence for increased degradation namely proteoglycan (PG) release and type II collagen cleavage in articular cartilage harvested from OCD lesions. We examined ex vivo explants at post‐mortem from equine OCD lesions and macroscopically normal site and age matched cartilage. These were cultured over a 10 day period in serum‐free medium. Type II collagen cleavage was measured in articular cartilage and media using an Elisa assay to detect the COL2‐3/Cshortepitope, which is generated on cleavage of the triple helix of type II collagen by collagenases. PG release was measured by a dye‐binding assay. Cumulative release of PG and COL2‐3/4Cshortand their contents in cartilage at the end of the culture period were determined. In OCD lesions there was a significant increase in type II collagen cleavage by collagenase but no evidence for increase of PG degradation. These findings point to a selective increase in type II collagen cleavage by collagenases, in OCD lesions of the kind observed in osteoarthritis. Further work is needed to determine whether changes represent primary or secondary events in the pathogenesis of OCD.

© 2002 Orthopaedic Research Society. Published by Elsevier Science Ltd. All rights reserved.
Increased reflex activation of the peroneus longus following application of an ankle brace declines over time
Authors: Nishikawa Tetsuo , Ozaki Takuma , Mizuno Kosaku , Grabiner Mark D.
Published: October 2002

Two experiments were performed to document the time‐dependent characteristics of the peroneus longus short latency stretch reflex amplitude following application of an ankle brace. In Experiment 1, stretch reflexes were induced in 15 weightbearing subjects during an unbraced condition and braced condition. In Experiment 2, stretch reflexes were induced in 15 weightbearing subjects before and after 3 h of wearing the brace. In Experiment 1, the amplitude of the stretch reflex increased in the braced condition by about 25% relative to the non‐braced condition (p = 0.006). In Experiment 2 the amplitude of the stretch reflex increased about 18% immediately after application of the brace relative to the non‐braced condition (p = 0.037). After 3 h, the stretch reflex amplitude was not different from that of initial non‐braced condition. Given the importance of the peroneus longus muscle in ankle complex stability, further attention should be directed to whether the increased stretch reflex gain can be exploited during rehabilitation from ankle complex injuries. The findings provide a framework by which the effect of ankle braces on ankle joint proprioception, muscle activation profiles and balance may be physiologically interpreted.

© 2002 Orthopaedic Research Society. Published by Elsevier Science Ltd. All rights reserved.
Fibronectin, MMP‐1 and histologic changes in rotator cuff disease
Authors: Tillander Bo , Franzén Lennart , Norlin Rolf
Published: October 2002

This study was designed to investigate human surgical specimens from patients with impingement (n = 16), ruptured supraspinatus tendons (n = 7), frozen shoulder (n = 2) and controls (n = 9) with respect to histological changes and the presence of fibronectin and Matrix metalloprotease‐1 (MMP‐1).

The biopsy of the middle part of the supraspinatus tendons was analyzed microscopically after staining with hematoxyline eosin, Van Giesons hematoxyline and Phospho Tungstic Acid Hematoxyline for visualization of fibrin. Immunofluorescent stainings for fibronectin and MMP‐1 were performed. Histology and immunofluorescence were assessed blindly.

Necrotic tendinous tissue and fibrin were found only in some specimens from ruptures. The staining for fibronectin was significantly increased among patients with a rupture. MMP‐1 was, however, only infrequently found in specimens from patients with impingement and ruptures. Fibrosis and thinning of fascicles seemed to be a more non‐specific finding, appearing in control, impingement and rupture specimens.

In conclusion, necrotic tendinous tissue, fibrin and fibronectin appear to be signs of tendon degeneration, whereas fibrosis and thinning of fascicles were found also in controls.

© 2002 Orthopaedic Research Society. Published by Elsevier Science Ltd. All rights reserved.
Interleukin‐1‐induced glenohumeral synovitis and shoulder pain in rotator cuff diseases
Authors: Gotoh Masafumi , Hamada Kazutoshi , Yamakawa Hideyuki , Yanagisawa Kazuhiro , Nakamura Masato , Yamazaki Hitoshi , Inoue Akio , Fukuda Hiroaki
Published: October 2002

Synovitis of the subacromial bursa has been identified as a main source of shoulder pain in rotator cuff diseases. Little interest, however, has been paid into the synovitis of glenohumeral joint. The mRNA expression levels of interleukin‐1β (IL‐1β) and interleukin‐1 receptor antagonists produced in the synovitis reflect the magnitude of inflammation. The present study was undertaken to determine the relationship between mRNA expression levels of IL‐1β and its receptor antagonists (secreted interleukin‐1 receptor antagonist (IL‐1ra) and intracellular IL‐1ra) in the synovium of the glenohumeral joint and shoulder pain in rotator cuff diseases, analyzing the synovial specimens by reverse transcriptase polymerase chain reaction. Thirty‐five patients with rotator cuff diseases were candidates. Based on the presence of cuff perforation, they were divided into two categories: 16 with non‐perforating tears and 19 with perforating tears. The degree of shoulder pain was evaluated by use of a visual analogue scale. The pain degree of non‐perforating tears was significantly greater than that of perforating tears (P < 0.01). In contrast, the expression levels of the cytokine‐mRNAs were constitutively greater in perforating tears than in non‐perforating tears (P < 0.01, respectively). The expression levels of the cytokine‐mRNAs were inversely correlated with the degree of pain (IL‐1β: r = 0.930; secreted IL‐1ra: r = 0.861: intracellular IL‐1ra: r = 0.932, P < 0.001 respectively). These results suggest that the expression levels of the cytokine‐mRNAs in the synovium of the glenohumeral joint contribute less to the generation of shoulder pain in rotator cuff diseases.

© 2002 Orthopaedic Research Society. Published by Elsevier Science Ltd. All rights reserved.
J‐integral fracture toughness and tearing modulus measurement of radiation cross‐linked UHMWPE
Authors: Gomoll A. , Wanich T. , Bellare A.
Published: October 2002

Radiation and chemical cross‐linking of medical grade ultrahigh molecular weight polyethylene (UHMWPE) has recently been utilized in an effort to improve wear performance of total joint replacement components. However, reductions in mechanical properties with cross‐linking are cause for concern regarding the use of cross‐linked UHMWPE for high‐stress applications such as in total knee replacement prostheses. In this study, the fracture behavior of radiation cross‐linked UHMWPE was compared to that of uncross‐linked UHMWPE. The Rice and Sorensen model that utilizes mechanical parameters obtained from uniaxial tensile and compact tension tests was used to calculate the steady state J‐integral fracture toughness, Jss, for radiation cross‐linked UHMWPE. Jss decreased monotonically with increase in radiation dose. UHMWPE exhibited tough, ductile tearing behavior with stable crack growth when it was cross‐linked using a gamma radiation dose of 0–50 kGy. However, in cross‐linked UHMWPE irradiated to a dose of 100 and 200 kGy, unstable fracture occurred spontaneously upon attaining the initial crack driving force, J1c. This indicates that a high degree of cross‐linking is less desirable for high‐stress applications in orthopaedic implants. However, a substantial increase in J1c, even at a low degree of cross‐linking, suggests that a low degree of cross‐linking may be beneficial for resistance to delamination and catastrophic failure, both of which require an initiation step for the fracture to propagate in the material. This mechanical test should, however, be considered along with fatigue tests and joint simulator testing before determination of an appropriate amount of cross‐linking for total joint replacement prostheses that experience high stresses.

© 2002 Orthopaedic Research Society. Published by Elsevier Science Ltd. All rights reserved.
Neither increased nor decreased availability of cortical serotonin (5HT) disturbs barrel field formation in isocaloric undernourished rat pups
Authors: Gutiérrez‐Ospina Gabriel , Manjarrez‐Gutiérrez Gabriel , González Cesar , López Sandra , Herrera Rocı́o , Medina Aguirre Ivett , Hernández‐R Jorge
Published: October 2002

Serotonin (5HT) is expressed transiently in primary sensory areas of the rat neocortex during the establishment of the thalamo‐cortical topography and somatotopy. The precise role of 5HT during the specification of neocortical areas is still uncertain. We evaluated the effects of increasing and decreasing cortical serotonin concentrations on the specification of the barrel cortex using a rat model of isocaloric undernutrition. This manipulation increases brain 5HT levels during brain development. Undernourished animals were also treated with p‐clorophenylalanine; an inhibitor of 5HT synthesis. Barrels representing the head were readily seen at postnatal day 5 in control and p‐clorophenylalanine treated rats. In contrast, undernourished rats treated or not with p‐clorophenylalanine showed no barrels representing the head but until postnatal day 7. Chromatographic analyses demonstrated that the concentration of cortical 5HT increased by 50% in undernourished pups during barrel field formation. Control and undernourished animals treated with p‐clorophenylalanine had a significant reduction (90%) of 5HT in the cortex. The overall geometry of the barrel field and of individual barrels was similar among animal groups. Our results support that 5HT plays a small role in triggering and timing barrel field somatotopy.
Neonatal electrolytic lesions of the basal forebrain stunt plasticity in mouse barrel field cortex
Authors: Nishimura Akira , Hohmann Christine F. , Johnston Michael V. , Blue Mary E.
Published: October 2002

Previous studies have shown that neonatal electrolytic lesions of basal forebrain cholinergic projections in mice lead to a transient cholinergic depletion of neocortex and to permanent alterations in cortical cytoarchitecture and in cognitive performance. The present study examines whether neonatal electrolytic lesions of the basal forebrain modify neocortical plasticity. Using cytochrome oxidase histochemistry, we compared cross‐sectional areas of individual barrels in the barrel field of four groups of postnatal day 8 (P8) old mice that on P1 received either (1) right electrolytic lesions of the basal forebrain, (2) left C row 1–4 whisker follicle ablations, (3) combined lesion treatments or (4) ice anesthesia only. The size of barrels in basal forebrain lesioned animals was not significantly different from controls. However, the plastic response to whisker removal was compromised in basal forebrain lesioned animals. An index of plasticity, the ratio of row D/row C areas, was reduced significantly in the combined nBM lesioned/follicle ablation group. Compared to whisker‐lesioned mice, the expansion in rows B and D and the shrinkage in the lesioned row C area were diminished in the combined treatment group. The present findings correspond to those from a study of rats injected with a cholinergic immunotoxin [Cereb. Cortex 8 (1998) 63]. These results suggest that cholinergic inputs play a role in regulating plasticity as well as in the morphogenesis of mouse sensory‐motor cortex.
SETS OF UNIQUENESS OF SERIES OF STOCHASTICALLY INDEPENDENT FUNCTIONS
Authors: Freniche Francisco J. , Ríos-Collantes-de-Terán Ricardo
Published: October 2002

It is shown that, for every sequence $(f_n)$ of stochastically independent functions defined on $[0,1]$—of mean zero and variance one, uniformly bounded by $M$—if the series $\sum_{n=1}^\infty a_nf_n$ converges to some constant on a set of positive measure, then there are only finitely many non-null coefficients $a_n$, extending similar results by Stechkin and Ul’yanov on the Rademacher system. The best constant $C_M$ is computed such that for every such sequence $(f_n)$ any set of measure strictly less than $C_M$ is a set of uniqueness for $(f_n)$.

AMS 2000 Mathematics subject classification:Primary 42C25. Secondary 60G50
ON THE STABILITY OF RICCATI DIFFERENTIAL EQUATION X˙ = TX+Q(X) IN ℝn
Authors: Mencinger Matej
Published: October 2002

The system $\dot{X}=TX+Q(X)$ (in $\mathbb{R}^{n}$), where $T$ is linear and $Q$ is quadratic, is considered via commutative algebras. The case of the linearized system having a centre manifold spanned on vectors $E_{1}$, $E_{2}$ (and $TE_{1}=\omega E_{2}$, $TE_{2}=-\omega E_{1}$) is studied. It is shown that for $\Span(E_{1},E_{2})$ being a subalgebra (of the algebra corresponding to the form $Q(X)$), the system is stable. Necessary and sufficient conditions are given for stability of the system in the case where $\mathrm{span}(E_{1},E_{2})$ is not a subalgebra.

AMS 2000 Mathematics subject classification: Primary 34A34; 34C15; 34C27; 34C35. Secondary 13M99
ON LOCAL FINITENESS OF PERIODIC RESIDUALLY FINITE GROUPS
Authors: Kuzucuoğlu Mahmut , Shumyatsky Pavel
Published: October 2002

Let $G$ be a periodic residually finite group containing a nilpotent subgroup $A$ such that $C_G(A)$ is finite. We show that if $\langle A,A^g\rangle$ is finite for any $g\in G$, then $G$ is locally finite.

AMS 2000 Mathematics subject classification: Primary 20F50
ON THE GROUP AutΩ(X)
Authors: Paves˘ić Petar
Published: October 2002

Felix and Murillo introduced the group $\mathrm{Aut}_\varOmega(X)$ of self-maps $f$ of $X$, which satisfy $\sOm f=1_{\varOmega X}$, and proved that the group is nilpotent with the order of nilpotency bounded by the Lusternik–Schnirelmann category of $X$. In this paper we construct a spectral sequence converging to the group $\mathrm{Aut}_\varOmega(X)$ and derive several interesting consequences.

AMS 2000 Mathematics subject classification: Primary 55P42
STURM–LIOUVILLE PROBLEMS WITH BOUNDARY CONDITIONS RATIONALLY DEPENDENT ON THE EIGENPARAMETER. I
Authors: Binding Paul A. , Browne Patrick J. , Watson Bruce A.
Published: October 2002

We consider the Sturm–Liouville equation

$$ -y''+qy=\lambda y\quad\text{on }[0,1], $$

subject to the boundary conditions

$$ y(0)\cos\alpha=y'(0)\sin\alpha,\quad\alpha\in[0,\pi), $$

and

$$\frac{y'}{y}(1)=a\lambda+b-\sum_{k=1}^N\frac{b_k}{\lambda-c_k}. $$

Topics treated include existence and asymptotics of eigenvalues, oscillation of eigenfunctions, and transformations between such problems.

AMS 2000 Mathematics subject classification: Primary 34B24; 34L20
ON A GAMMA FUNCTION INEQUALITY OF GAUTSCHI
Authors: Alzer Horst
Published: October 2002

We prove the following.

(1) The inequalities

$$ \biggl(2-\frac{1}{\varGamma(x)}\biggr)^{\!a}+\biggl(2-\frac{1}{\varGamma(1/x)}\biggr)^{\!a}\leq 2\leq\biggl(2-\frac{1}{\varGamma(x)}\biggr)^{\!b}+\biggl(2-\frac{1}{\varGamma(1/x)}\biggr)^{\!b} $$

hold for all $x>0$ if and only if

$$ -1.204\,64\ldots=2+\frac{1}{\gamma}-\frac{1}{6}\biggl(\frac{\pi}{\gamma}\biggr)^{\!2}\leq a\leq0\leq b. $$

(2) For all real numbers $x\in(0,1]$ we have

$$ x^{\alpha}\leq\frac{1}{2}\biggl(\frac{1}{\varGamma(x)}+\frac{1}{\varGamma(1/x)}\biggr)\leq x^{\beta}, $$

with the best possible constants

$$ \alpha=1.321\,76\dots\link{and}\beta=0. $$

These theorems extend and complement a result of Gautschi (from 1974), who proved that for all $x>0$ the harmonic mean of $\varGamma(x)$ and $\varGamma(1/x)$ is greater than or equal to $1$.

AMS 2000 Mathematics subject classification: Primary 33B15; 26D15
Two-stage clustering in genotype-by-environment analyses with missing data
Authors: GODFREY A. J. R. , WOOD G. R. , GANESALINGAM S. , NICHOLS M. A. , QIAO C. G.
Published: October 2002

Cluster analysis has been commonly used in genotype-by-environment (G×E) analyses, but current methods are inadequate when the data matrix is incomplete. This paper proposes a new method, referred to as two-stage clustering, which relies on a partitioning of squared Euclidean distance into two independent components, the G×E interaction and the genotype main effect. These components are used in the first and second stages of clustering respectively. Two-stage clustering forms the basis for imputing missing values in the G×E matrix, so that a more complete data array is available for other G×E analyses. Imputation for a given genotype uses information from genotypes with similar interaction profiles. This imputation method is shown to improve on an existing nearest cluster method that confounds the G×E interaction and the genotype main effect.
Triple test cross and six-population techniques for partitioning the components of genetic variance in faba bean (Vicia faba)
Authors: BAKHEIT B. R. , EL-HIFNY M. Z. , EISSA M. M. , RAGHEB S. B.
Published: October 2002

The efficiency of the triple test cross (TTC) and the six-population biometrical analyses was compared in terms of assessing and quantifying the components of genetic variance for two faba bean crosses: Triple White×Giza 843 and NA112×Giza 429. Several traits were studied including days to first flower, plant height, branches/plant, pods/plant, seeds/pod, 100-seed weight and seed yield/plant. The results supported the triple test cross biometrical approach as it uses first degree statistics and can be applied to any population irrespective of its genetic architecture. Absence of a scalar relationship between triple test cross families (orthogonality) ensures independence between means and variance with no restrictive assumptions. Both methods provided evidence for epistasis, and both additive and dominance genetic components in the genetic control of the studied traits.
Effect of season on thermoregulatory responses and energy expenditure of goats on semi-arid range in India
Authors: SHINDE A. K. , BHATTA RAGHAVENDRA , SANKHYAN S. K. , VERMA D. L.
Published: October 2002

A study of the physiological responses and energy expenditure of goats was carried out from June 1999 to May 2000 by conducting two experiments: one on bucks maintained on stall feeding in autumn 1999 (Expt 1) followed by year-round grazing on native ranges over three seasons: monsoon, winter and summer (Expt 2). Physiological responses and energy expenditure (EE) measurements of housed and grazing goats were recorded at 06.00 h and 14.00 h for 5 consecutive days in each season. Goats were fixed with a face mask and meteorological balloon for collection of expired air and measurement of EE. Respiration rate (RR) at 06.00 h was similar in all seasons (14 respiration/min) except in the monsoon, where a significantly (P<0.05) higher value (26 respiration/min) was recorded. At 14.00 h, RR was higher in monsoon and summer (81 and 91 respiration/min) than in winter (52 respiration/min). Irrespective of the season, heart rate (HR) was higher at 14.00 h (86 beat/min) than at 06.00 h (64 beat/min). The rise of rectal temperature (RT) from morning (06.00 h) to peak daily temperature (14.00 h) was 0.9 °C in housed goats in autumn and 1.0, 2.1 and 2.0 °C in grazing goats during monsoon, winter and summer, respectively. The mean value was 1.7 °C. Skin temperature (ST) was lowest in winter (30.1 °C) and highest at 14.00 h in summer (40.3 °C). Energy expenditure of goats at 06.00 h was 32.7 W in winter and significantly (P<0.05) increased to 52.0 W in summer and 107.8 W in monsoon. At 14.00 h, EE was 140.2 W in winter and increased to 389.0 W and 391.3 W respectively in monsoon and summer. It is concluded that monsoon and summer are both stressful seasons in semi-arid regions. Animals should be protected from direct solar radiation during the hottest hours of the day to ameliorate the effect of heat stress.