bluuebunny/crossref_metadata_2025 huggingface dataset:
Die Vegetation des Bogd‐uul bei Ulaanbaatar (Mongolei) – Standortsbindung und pflanzengeographische Stellung
Authors: Hilbig W. , Jäger E. J. , Knapp H. D.
Published: July 2004

Die Pflanzengesellschaften des Bogd‐uul‐Massivs südlich Ulaanbaatar werden dargestellt und mit Vegetationsaufnahmen belegt. Neben der flächenhaft ausgebildeten Vegetation der Steppen, der Wiesensteppen, der Lärchen‐, Kiefern‐, Fichten‐ und Arven‐Wälder sowie der subalpinen Strauchbirkenmoore und Kobresia‐Rasen werden auch Gebüsche, Blockfluren, Hochstaudenfluren, Salzwiesen und Ruderalgesellschaften berücksichtigt. Alle Vegetationstypen werden hinsichtlich ihrer Standortsbindung charakterisiert. Dargestellt wird auch die Geschichte dieses bedeutenden Naturreservates und die wechselnde Rolle anthropo‐zoogener Eingriffe.

Zu der bisher vorliegenden Florenliste von Ganbold et al. (1993) werden 26 Arten als Neunachweise ergänzt. Die Gesamtzahl von etwa 600 Arten auf 400 km2 ist charakteristisch für ein hochkontinentales Gebirge an der Südgrenze der temperaten Zone.

Für alle in den Vegetationsaufnahmen angetroffenen Arten wurde die Gesamtverbreitung kartiert. 24 Arealkarten werden als Beispiele abgedruckt. Fast alle Areale (einige synanthrop stark erweiterte ausgenommen) lassen sich 20 Arealtypen zuordnen. Die ökogeographischen Grenzfaktoren dieser Typen werden diskutiert. Der Anteil der Arten mit diesen Arealtypen unterscheidet sich in den verschiedenen Pflanzengesellschaften deutlich. Das wird in Diagrammen dargestellt. Während in den unteren Höhenstufen eng verbreitete, an die relativ sommerfeuchte Ostseite Eurasiens gebundene Arten vorherrschen, dominieren in der hochmontanen und subalpinen Stufe Arten mit weiter circumpolarer Verbreitung. Aus den Arealen ergeben sich auch Hinweise auf die geographische Reichweite der beschriebenen Pflanzengesellschaften. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Genes expressed in the human trabecular meshwork during pressure‐induced homeostatic response
Authors: Vittitow Jason , Borrás Teresa
Published: July 2004

Physiological pressure inside the eye is maintained by a resistance mechanism provided by the trabecular meshwork tissue. In most cases, prolonged, elevated pressure leads to an eye pathology characterized by retinal ganglion cell (RGC) degeneration, optic nerve damage, and non‐remedial blindness. We are investigating the regulation of trabecular meshwork genes in response to elevated pressure. Using perfused organ cultures from postmortem human donors, we have previously demonstrated the presence of a homeostatic mechanism at 2–4 days of pressure insult (Borrás et al. 2002, Invest Ophthalmol Vis Sci 43:33–40). Here, we sought to identify trabecular meshwork genes whose expression was altered during this homeostatic period. By macroarray hybridization, we compared the expression profiles of high‐pressure (HP) and normal‐pressure (NP) treated eyes from the same individual (n = 3 pairs). Our results identified 40 upregulated and 14 downregulated genes. The highest proportion of upregulated genes encoded proteins involved in signal transduction (32%). Among the potentially relevant genes, PIP 5K1C, VIP, tropomodulin, and MMP2 encoded mediators known to influence outflow resistance. Others encoded functions which are new for the trabecular meshwork, but which are intrinsic to unrelated tissues. These new mechanisms appear as they could be of benefit for trabecular meshwork function. Matrix Gla protein (MGP), perlecan, osteomodulin, and osteoblast‐specific factor are essential in cartilage and bone physiology whereas spectrin and ICAM4 are specific for blood cells and crucial in maintaining their shape and adhesion. In addition, MGP transcripts were stimulated by extracellular calcium and downregulated by TGF‐β1. We propose that MGP might be an important player in the adaptive homeostatic mechanism by contributing to maintain a softer trabecular meshwork tissue and facilitate aqueous humor outflow. J. Cell. Physiol. 201: 126–137, 2004. © 2004 Wiley‐Liss, Inc.
Exogenous metalloporphyrins alter the organization and function of cultured neonatal rat heart cells via modulation of heme oxygenase activity
Authors: Akins Robert , McLaughlin Terry , Boyce Roberta , Gilmour Laura , Gratton Kara
Published: July 2004

Heme oxygenase (HO), the enzyme responsible for heme catabolism, has been associated with the function of both skeletal and smooth muscle cells and with protection of the heart against ischemia/reperfusion injury. Exposure of skeletal muscle cultures to heme, the physiological substrate for HO, has been shown to improve differentiation and aerobic metabolism. Little is known, however, about the roles that heme and heme metabolism play in cardiac muscle, and the present study was conducted to examine the effects of exogenous heme on cultured heart cells in the presence or absence of modulators of HO activity. Treatment of neonatal rat ventricular cells with heme resulted in increases in four key indicators: (1) the activity of metabolic enzymes, (2) the rate of spontaneous contraction, (3) the level of myosin heavy chain (MyHC) expressed, and (4) the amount of actin organized as filaments. Treatment with heme while metabolically inhibiting increased HO activity altered these effects such that: (1) increases in enzyme activities were attenuated, (2) spontaneous beating ceased, (3) the level of MyHC was reduced, and (4) the amount of filamentous actin was severely decreased to the point where myofibrils were no longer evident. These results suggest that heme and its catabolites act to modulate aspects of cardiac cell function and organization. J. Cell. Physiol. 201: 26–34, 2004. © 2004 Wiley‐Liss, Inc.
Thyroid hormone stimulates osteoclast differentiation by a mechanism independent of RANKL–RANK interaction
Authors: Kanatani Masanori , Sugimoto Toshitsugu , Sowa Hideaki , Kobayashi Tatsuya , Kanzawa Michiko , Chihara Kazuo
Published: July 2004

It is well known that thyroid hormone excess causes bone loss. However, the precise mechanism of bone loss by thyroid hormone still remains unclear. When T3was added to unfractionated bone cells after degeneration of pre‐existent osteoclasts, T3(1 pM–100 nM) dose‐dependently stimulated osteoclast‐like cell formation, irrespective of the presence of indomethacin and IL‐6 Ab. T3increased the expression of osteoprotegerin (OPG) messenger RNA (mRNA), but not of receptor activator of nuclear factor κB ligand (RANKL) in unfractionated bone cells, suggesting that the stimulatory effect of T3on osteoclast formation was not mediated by the RANKL/OPG system. We next examined the direct effect of T3on osteoclast precursors in the absence of osteoblasts, using hemopoietic blast cells derived from spleen cells. T3(1 pM–100 nM) dose‐dependently stimulated osteoclast‐like cell formation from osteoclast precursors. OPG did not inhibit T3‐induced osteoclast formation from osteoclast precursor cells. The polymerase chain reaction (PCR) product corresponding in size to the mouse T3receptor α1 cDNA was detected in osteoclast precursors from mouse hemopoietic blast cells as well as mouse heart and mouse osteoblastic cell line MC3T3‐E1 cells, suggesting that T3directly stimulated osteoclast‐like cell formation from osteoclast precursors in the absence of osteoblasts. Further, T3increased the expression of c‐Fos mRNA at 15 min and 24 h and Fra‐1 mRNA at 2 and 6 h in osteoclast precursors. Consistent with the increased expression of c‐Fos mRNA observed by RT‐PCR, the activation of c‐Fos occurred in osteoclast precursor cells stimulated by T3, while the activation of neither NF‐κB nor MAPKs was observed by immunoblot analysis. Antisense oligodeoxynucleotides (as‐ODN) complementary to c‐Fos mRNA at 1 μM significantly inhibited T3‐induced osteoclast‐like cell formation from osteoclast precursors in the absence of stromal cells while sense‐ODN did not affect T3‐induced osteoclast‐like cell formation. These results indicate that T3directly stimulates osteoclast differentiation at least in part by up‐regulation of c‐fos protein in osteoclast precursor cells. J. Cell. Physiol. 201: 17–25, 2004. © 2004 Wiley‐Liss, Inc.
Photoreceptor topography in the duplex retina of the paddlefish (Polyodon spathula)
Authors: Sillman Arnold J. , Dahlin David A.
Published: July 2004

Retinal whole‐mount preparations from the eyes of the North American paddlefish, Polyodon spathula, were examined with a combination of bright field and differential interference contrast microscopy. The entire retina was mapped and population counts of rod and cone photoreceptors were made at regular intervals throughout the retina. The retina is dominated by rods, but a significant percentage (ca. 38%) of the photoreceptors are cones. Mean cone packing density for the entire retina is 6,402±1,216 cones/mm2. There is a small (16%) but statistically significant difference between cone packing density in the dorsal retina (6,674±1,168 cones/mm2) and the ventral retina (5,745±1,076 cones/mm2). There is no region of unusually high cone concentration that might be construed as a fovea or a visual streak. Mean rod packing density for the entire retina is 10,271±1,205 rods/mm2. Except in the far periphery, where rods are less numerous, the density of rods is fairly uniform throughout the retina. The data are discussed with regard to paddlefish habitat and behavior. J. Exp. Zool. 301A:674–681, 2004. © 2004 Wiley‐Liss, Inc.
N‐Oxyl‐Controlled Radical Copolymerization of Styrene with Ethyl α‐Cyanocinnamate
Authors: Bartsch Andreas , Schmidt‐Naake Gudrun
Published: July 2004

Summary: The block copolymers of styrene and ethyl α‐cyanocinnamate were prepared in dioxane and xylene with TEMPO‐capped polystyrene (PSTEMPO) as macroinitiator. The copolymerizations were carried out at 125 °C and 135 °C. The reactivity ratios were determined according to Kelen Tüdos and compared with the reactivity ratios from the radical copolymerization of styrene and ethyl α‐cyanocinnamate determined by Kohn et al. The influence of the comonomer ethyl α‐cyanocinnamate on the glass transition temperature was studied in comparison with the corresponding homopolystyrene.

Plots of conversion versus molecular weight distributions of the polymerizations with styrene at 125 °C.

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Plots of conversion versus molecular weight distributions of the polymerizations with styrene at 125 °C.
Poly(neopentylene carbonate) Hyperstars
Authors: Löwenhielm Peter , Claesson Hans , Hult Anders
Published: July 2004

Summary: Branched aliphatic polycarbonates were synthesized by ring opening polymerization of 5,5‐dimethyl‐1,3‐dioxane‐2‐one (NPC) initiated from polyfunctional alcohols and a commercial hyperbranched polyester (BOLTORN®). Polymerizations in the presence of fumaric acid under bulk conditions allowed high conversion (80%) without gelation. The synthesis of polymers with long chain branches was confirmed by size exclusion chromatography and universal calibration. The Mark–Houwink exponent decreased, indicating an increased density, while increasing the number of arms. The star polymers with up to four arms showed thermal properties Tg (20–30 °C) and Tm (100–110 °C) similar to linear PNPC.

Boltorn™ hyperbranched polymer with radial polycarbonate grafts.

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Boltorn™ hyperbranched polymer with radial polycarbonate grafts.
On the Radiation‐Induced Polymerisation of 2,3‐Dihydropyran
Authors: Naumov Sergej , Janovský Igor , Knolle Wolfgang , Mehnert Reiner
Published: July 2004

Summary: Concentrated (5 mol‐%) solutions of 2,3‐dihydropyran in CFCl2CF2Cl matrix were irradiated at 77 K and several intermediates – radical cation, dimer radical cation, dihydropyryl radical and a trapped polymer radical – were observed by low‐temperature EPR spectroscopy. The irradiated solutions yielded after melting a polymeric product, which was characterised by IR spectroscopy and GPC. The polydisperse polymer is assumed to be formed by a cationic process initiated by a dimer carbocation. The polymerization proceeds via the ring double bonds, while ring‐opening reaction occurs in a small extent. The free‐radical mechanism via the dihydropyryl radical leads to low molecular weight oligomers only. The quantum chemical calculations support the interpretation of the experimental results.

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Isobutene Polymerization and Copolymerization with Isoprene Initiated by [Cp*TiMe2]+ in the Presence of a Novel Type of Weakly Coordinating Counteranion
Authors: Tse Calvin K. W. , Kumar Kainthan Rajesh , Drewitt Mark J. , Baird Michael C.
Published: July 2004

Summary: The highly electrophilic borane B(C6F5)3 reacts with octadecanoic acid (n‐C17H35CO2H, stearic acid) to form 1:1 and 2:1 adducts [n‐C17H35CO2H][B(C6F5)3] and [n‐C17H35CO2H][B(C6F5)3]2. These adducts exhibit enhanced acidities, and react with Cp*TiMe3 in methylene chloride and toluene to give methane and the complexes [Cp*TiMe2][n‐C17H35CO2{B(C6F5)3}1,2]; the 2:1 complex in particular is a very good initiator for the carbocationic polymerization of isobutene (IB) and copolymerization of IB with isoprene at temperatures as high as −30 °C. High conversions to high molecular weight homo‐ and copolymers are obtained, consistent with the anion [n‐C17H35CO2{B(C6F5)3}2]− being very weakly coordinating.

Novel class of Brønsted acidic initiators behave as very good initiators, e.g. in homopolymerisation of isobutene.

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Novel class of Brønsted acidic initiators behave as very good initiators, e.g. in homopolymerisation of isobutene.
Microstructure and Properties of Poly(amide urethane)s: Comparison of the Reactivity of α‐Hydroxy‐ω‐O‐phenyl Urethanes and α‐Hydroxy‐ω‐O‐hydroxyethyl Urethanes
Authors: Sharma Bhaskar , Ubaghs Luc , Keul Helmut , Höcker Hartwig , Loontjens Ton , van Benthem Rolf
Published: July 2004

Summary: Poly(amide urethane)s were prepared from ε‐caprolactam, amino alcohols, and diphenyl carbonate or ethylene carbonate in three steps. Polycondensation was performed either with α‐hydroxy‐ω‐O‐phenyl urethanes or with α‐hydroxy‐ω‐O‐hydroxyethyl urethanes; it was found that the reactivity at 90 °C of the first is much higher than that of the latter. For nearly equal reactivity, the temperature for the polycondensation of α‐hydroxy‐ω‐O‐hydroxyethyl urethanes had to be increased from 90 °C to 150 °C. The microstructure of the resulting poly(amide urethane)s differs by the content of urea groups in the polymer chains, which is 5% for poly(amide urethane)s prepared from α‐hydroxy‐ω‐O‐phenyl urethanes and 15% for poly(amide urethane)s prepared from α‐hydroxy‐ω‐O‐hydroxyethyl urethanes. As a consequence, the thermal properties of the poly(amide urethane)s differ slightly.

Synthesis of poly(amide urethane)s.

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Synthesis of poly(amide urethane)s.
Surfactant‐Free Emulsion Polymerization of Various Methacrylates: Towards Monodisperse Colloids for Polymer Opals
Authors: Egen Marc , Zentel Rudolf
Published: July 2004

Summary: A systematic investigation of the surfactant‐free emulsion polymerization (SFEP) on three different methacrylates (MMA, tert‐butyl methacrylate and 2,2,2‐trifluoro ethyl methacrylate) is described to obtain monodisperse colloids for the preparation of artificial “polymer opals”. The experimental results are in agreement with a model, in which seed particles are formed very early during the polymerization process. The particles grow afterwards into the colloids until all monomer is consumed. This gives rise to a linear relationship between the volume of the colloids and the ratio of monomer to water in the reaction batch. The concentration of the seed particles depends thereby on the hydrophobicity of the monomers and can be varied by the addition of salt. The relationship between the composition of the reaction batch and the size of the colloids differs from monomer to monomer. It can, however, be described for all systems by the introduction of an empirical system dependent parameter pM (master curve). It is thus possible to predict the colloidal size for new monomer (or salt) systems from a single measurement point. Colloids with a diameter of more than 500 nm can be prepared by a two stage seeded polymerization. The colloids prepared with this method are so monodispersed (well below 5%) that they can easily be crystallized into artificial polymer opals of a high optical quality.

Dried opaline films (second‐order reflection).

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Dried opaline films (second‐order reflection).
UNFOLD‐SENSE: A parallel MRI method with self‐calibration and artifact suppression
Authors: Madore Bruno
Published: July 2004

This work aims at improving the performance of parallel imaging by using it with our “unaliasing by Fourier‐encoding the overlaps in the temporal dimension” (UNFOLD) temporal strategy. A self‐calibration method called “self, hybrid referencing with UNFOLD and GRAPPA” (SHRUG) is presented. SHRUG combines the UNFOLD‐based sensitivity mapping strategy introduced in the TSENSE method by Kellman et al. (5), with the strategy introduced in the GRAPPA method by Griswold et al. (10). SHRUG merges the two approaches to alleviate their respective limitations, and provides fast self‐calibration at any given acceleration factor. UNFOLD‐SENSE further includes an UNFOLD artifact suppression scheme to significantly suppress artifacts and amplified noise produced by parallel imaging. This suppression scheme, which was published previously (4), is related to another method that was presented independently as part of TSENSE. While the two are equivalent at accelerations ≤ 2.0, the present approach is shown here to be significantly superior at accelerations > 2.0, with up to double the artifact suppression at high accelerations. Furthermore, a slight modification of Cartesian SENSE is introduced, which allows departures from purely Cartesian sampling grids. This technique, termed variable‐density SENSE (vdSENSE), allows the variable‐density data required by SHRUG to be reconstructed with the simplicity and fast processing of Cartesian SENSE. UNFOLD‐SENSE is given by the combination of SHRUG for sensitivity mapping, vdSENSE for reconstruction, and UNFOLD for artifact/amplified noise suppression. The method was implemented, with online reconstruction, on both an SSFP and a myocardium‐perfusion sequence. The results from six patients scanned with UNFOLD‐SENSE are presented. Magn Reson Med 52:310–320, 2004. © 2004 Wiley‐Liss, Inc.
Tubule and neurofilament immunoreactivity in human hairy skin: Markers for intraepidermal nerve fibers
Authors: Lauria Giuseppe , Borgna Monica , Morbin Michela , Lombardi Raffaella , Mazzoleni Giulia , Sghirlanzoni Angelo , Pareyson Davide
Published: July 2004

The cytoplasmic protein gene product 9.5 (PGP 9.5) is considered a reliable marker for intraepidermal nerve fibers (IENFs). However, PGP 9.5 expression has never been compared with antibodies against the main components of the cytoskeleton. We compared the density of PGP 9.5–positive IENF at the leg with that obtained using a panel of antibodies specific for certain cytoskeletal components, namely, anti–unique β‐tubulin (TuJ1), anti–nonphosphorylated microtubule‐associated protein‐1B (MAP1B), anti‐70 and 200 KDa neurofilament (NF), and antiphosphorylated neurofilament (SMI 312), in 15 healthy subjects and in 10 patients with painful neuropathy. We also performed colocalization studies and investigated the relationship between IENFs and Schwann cells. In both controls and neuropathies, the density of IENF labeled by PGP 9.5, TuJ1, and MAP1B did not differ, whereas that of NF and SMI 312 was significantly lower. Double‐staining studies confirmed that antibodies against cytoskeletal markers can be used to reliably stain skin nerve fibers, suggesting that they might provide insight into specific axonal impairment in peripheral neuropathies. Muscle Nerve 30: 310–316, 2004
Reduced acetylcholine receptor density, morphological remodeling, and butyrylcholinesterase activity can sustain muscle function in acetylcholinesterase knockout mice
Authors: Adler Michael , Manley Heather A. , Purcell Angela L. , Deshpande Sharad S. , Hamilton Tracey A. , Kan Robert K. , Oyler George , Lockridge Oksana , Duysen Ellen G. , Sheridan Robert E.
Published: July 2004

Nerve‐evoked contractions were studied in vitro in phrenic nerve–hemidiaphragm preparations from strain 129X1 acetylcholinesterase knockout (AChE−/−) mice and their wild‐type littermates (AChE+/+). The AChE−/− mice fail to express AChE but have normal levels of butyrylcholinesterase (BChE) and can survive into adulthood. Twitch tensions elicited in diaphragms of AChE−/− mice by single supramaximal stimuli had larger amplitudes and slower rise and decay times than did those in wild‐type animals. In AChE−/− preparations, repetitive stimulation at frequencies of 20 and 50 Hz and at 200 and 400 Hz produced decremental muscle tensions; however, stimulation at 70 and 100 Hz resulted in little or no loss of tension during trains. Muscles from AChE+/+ mice maintained tension at all frequencies examined but exhibited tetanic fade after exposure to the selective AChE inhibitor 1,5‐bis(4‐allyldimethyl‐ammoniumphenyl)pentane‐3‐one (BW 284C51). The ability of diaphragm muscles from AChE−/− mice to maintain tension at 70 and 100 Hz suggests a partial compensation for impairment of acetylcholine (ACh) hydrolysis. Three mechanisms—including a reliance on BChE activity for termination of ACh action, downregulation of nicotinic acetylcholine receptors (nAChRs), and morphological remodeling of the endplate region—were identified. Studies of neuromuscular transmission in this model system provide an excellent opportunity to evaluate the role of AChE without complications arising from use of inhibitors. Muscle Nerve 30: 317–327, 2004
Postactivation potentiation in human muscle is not related to the type of maximal conditioning contraction
Authors: Baudry Stéphane , Duchateau Jacques
Published: July 2004

The mechanical performance of a muscle can be enhanced by preceding contractile activity, such as occurs with postactivation potentiation. To investigate whether the type of contraction influences the extent of potentiation, the effects of 6‐s maximal isometric (ISO), concentric (CON), and eccentric (ECC) maximal voluntary contractions (MVC) on the muscle twitch were compared in the tibialis anterior of nine subjects. The study also examined the effect of postactivation potentiation on the force evoked by the second (C2) and third (C3) responses of two‐pulse (PT2) and three‐pulse (PT3) trains that were delivered at a 10‐ms interpulse interval. The results showed that immediately after the conditioning MVC, twitch torque (Pt) and its maximal rate of torque development (+dPt/dt) and relaxation (‐dPt/dt) were significantly enhanced, without any change in contraction time (CT), half‐relaxation time (½RT), and compound muscle action potential (M wave). The extent of Pt potentiation was similar for all MVC modalities, and the mean maximal values ranged from 150% to 180%. Furthermore, postactivation potentiation was greater for the single pulse compared with PT2 and PT3 responses. All parameters returned to initial values within 7–10 min. Although Pt (or C1) was potentiated more than was C2 and C3, its decline over time was proportionally more rapid than those for C2 and C3. We conclude that postactivation potentiation was not related to the type of conditioning MVC under these experimental conditions. The observation that postactivation potentiation increased C1 more than C2 and C3 indicates that a saturation process limits the extent of potentiation during the summation of successive responses to a train of stimuli. These results have practical application in the design of functional electrical stimulation protocols. Muscle Nerve, 2004
Evaluation of patients with recurrent symptoms after ulnar nerve transposition
Authors: Matei Cristina I. , Logigian Eric L. , Shefner Jeremy M.
Published: July 2004

Focal entrapment of the ulnar nerve occurs most frequently in the region of the elbow, at the ulnar groove or beneath the humeroulnar aponeurosis. Surgical treatment commonly involves transposition of the nerve anterior to the medial epicondyle, in the antecubital fossa. Symptoms may recur after surgery, and, to assess their etiology, we studied 10 patients with recurrent ulnar symptoms after transposition. Conventional motor and sensory conduction studies were performed, as was mapping of nerve position using submaximal stimuli. In 9 of 10 patients, the ulnar nerve at the elbow was located adjacent to the medial epicondyle, rather than in the antecubital fossa. Focal slowing in the region of the elbow was noted in 8 patients, and an additional site of focal slowing was found in the forearm in 3 patients. We conclude that in patients with recurrent symptoms after ulnar nerve transposition postoperative position of the ulnar nerve may be medial, often near the medial epicondyle. This location may predispose the nerve to recurrent trauma or cause traction on the nerve at more distal locations within the forearm. The prevalence of this medial location of the ulnar nerve in asymptomatic postsurgical patients is unknown. Muscle Nerve 30: 493–496, 2004
Motor unit characteristics in healthy subjects and those with postpoliomyelitis syndrome: A high‐density surface EMG study
Authors: Drost Gea , Stegeman Dick F. , Schillings Maartje L. , Horemans Herwin L. D. , Janssen Henny M. H. A. , Massa Mark , Nollet Frans , Zwarts Machiel J.
Published: July 2004

The purpose of this study was to identify optimal ways to detect neurogenic changes with high‐density surface electromyography (HD‐sEMG). For this purpose, we searched for the variables that most clearly discriminated between postpoliomyelitis and healthy subjects. We obtained HD‐sEMG from the quadriceps muscle at different force levels in nine subjects with postpoliomyelitis syndrome and in matched healthy controls. Single motor unit action potentials (MUAPs), extracted from the HD‐sEMG signal and the raw signal itself, were analyzed. Areas under the curve of the extracted MUAP waveform, indicating motor unit size, perfectly separated both groups. Raw signal analysis showed significant differences between groups for the monopolarly recorded amplitude up to 60% of maximal force and for the level of interference at higher force levels (40–100% force). We conclude that with HD‐sEMG it is possible to detect neurogenic motor unit changes noninvasively, both by analysis of the raw signal itself and by analysis of extracted single MUAPs. The diagnostic yield of the single MUAP analysis is clearly higher. These findings point toward applications for clinical practice and invite further studies exploring the diagnostic value of HD‐sEMG. Muscle Nerve 30: 269–276, 2004
Effect of heterogeneities on the physical properties of elastomers derived from butadiene cured with dicumyl peroxide
Authors: Gonzalez L , Rodriguez A , Del Campo A , Marcos‐Fernandez A
Published: July 2004

The scope of this paper is to continue our earlier study of the peroxide curing of elastomers derived from butadiene. Experimental evidence indicates that abstraction of allylic hydrogen and addition to the double bonds can act as a mechanism for cross‐linking. The addition reaction may give rise to a polymerization reaction between adjacent double bonds, thus generating a heterogeneous network, with negative effects on the physical properties of the vulcanizates. Copyright © 2004 Society of Chemical Industry
Initiator‐fragment incorporation radical polymerization of ethylene glycol dimethacrylate in the presence of 1,1‐diphenylethylene: synthesis and characterization of soluble hyperbranched polymer nanoparticles
Authors: Sato Tsuneyuki , Miyagi Takashi , Hirano Tomohiro , Seno Makiko
Published: July 2004

The polymerization of ethylene glycol dimethacrylate (EGDMA) as crosslinker was carried out at 70 and 80 °C in benzene using dimethyl 2,2′‐azobisisobutyrate (MAIB) as initiator at concentrations as high as 0.50–0.70 mol l−1 in the presence of 1,1‐diphenylethylene (DPE), where the concentrations of EGDMA and DPE were 0.50–0.70 and 0.25–0.50 mol l−1, respectively. The polymerization proceeded homogeneously, without gelation, to give soluble polymers. The yield and molecular weight of the resulting polymers increased with time. The homogeneous polymerization system involved ESR‐observable DPE‐derived radicals of considerably high concentration (3.6–5.3 × 10−5 mol l−1). The methoxycarbonylpropyl groups as MAIB‐fragments were incorporated as a main constituent (35–50 mol%) into the polymers (initiator‐fragment incorporation radical polymerization). The polymers also contained DPE units (15 mol%) and EGDMA units with double bonds (10–25 mol%) and without double bonds (20 mol%). Results from gel permeation chromatography (GPC)–multiangle laser light scattering (MALLS), transmission electron microscopy (TEM) and viscometric measurements revealed that the individual polymer molecules were formed as hyperbranched nanoparticles. Copyright © 2004 Society of Chemical Industry
Behavioral momentum in academics: Using embedded high‐p sequences to increase academic productivity
Authors: Lee David L. , Belfiore Phillip J. , Scheeler Mary Catherine , Hua Youjia , Smith Rachel
Published: July 2004

The use of high‐probability (high‐p) request sequences has enjoyed support in the applied behavioral literature as a method to increase compliance. Based on the theory of behavioral momentum, high‐probability sequences increase the rate of responding, and subsequent rate of reinforcement, within a response class. This increase in density of reinforcement results in increased responding for the response class as a whole. Early research in this area had focused mainly on compliance issues for individuals with developmental disabilities. However, more recently the utility of high‐p sequences has been examined within the context of academics. The purpose of these two experiments was to examine the use of high‐p sequences with two academic tasks—letter‐writing and mathematics problem completion. The results of these studies suggest that high‐p sequences can be used to increase academic productivity. Moreover, the addition of experimenter‐delivered reinforcers to existing high‐p sequences enhances overall behavioral persistence. Theoretical and applied implications of persistence and behavioral momentum are discussed. © 2004 Wiley Periodicals, Inc. Psychol Schs 41: 789–801, 2004.
Adjustment scales for preschool intervention: Extending validity and relevance across multiple perspectives
Authors: Bulotsky‐Shearer Rebecca , Fantuzzo John
Published: July 2004

A series of studies extended psychometric research on the Adjustment Scales for Preschool Intervention (ASPI). The ASPI is a multidimensional measure of preschool emotional and behavioral adjustment for use within formal early childhood educational programs. These studies used a multiple method, multisource approach to provide additional evidence for the reliability and validity of the ASPI. Findings documented inter‐rater reliability of the ASPI across key informants within early childhood educational programs—teachers and teacher assistants. Findings supported concurrent validity of the ASPI with direct observations of preschool classroom adjustment problems and the developmentally salient constructs of temperament and emotion regulation. Implications for policy, practice, and future research are discussed. © 2004 Wiley Periodicals, Inc. Psychol Schs 41: 725–736, 2004.
Synthesis of large, high‐solid‐content latexes by miniemulsion polymerization
Authors: Do Amaral Marcelo , Asua José M.
Published: July 2004

Multiple and diverse applications have been recently found for miniemulsions and miniemulsion polymerization. In this work, miniemulsion polymerization is presented as a suitable technique for the preparation of high‐solid‐content latices with large particle sizes. Monomer miniemulsions were prepared with a high‐pressure homogenizer, and droplet sizes of 200–700 nm were obtained. Latexes with particle sizes larger than the sizes commonly accepted for miniemulsion polymerization were obtained. With fixed operational conditions of the homogenizer, the type of stabilizer was the key parameter determining the droplet size and the droplet size distribution. The particle size of the latices obtained by miniemulsion polymerization indicated that the particles were mainly formed by droplet nucleation. Latexes obtained by this process have multiple applications, including use as seeds in the polymerization of high‐solid‐content latices. This article shows that potential new applications for miniemulsion polymerization are far from being exhausted. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 4222–4227, 2004
Linear response theory: An alternative to PB and GB methods for the analysis of molecular dynamics trajectories?
Authors: Morreale Antonio , de la Cruz Xavier , Meyer Tim , Gelpí Josep Lluís , Luque F. Javier , Orozco Modesto
Published: July 2004

We explore the use of classical Linear Response Theory (LRT) as an alternative strategy to the use of Molecular Mechanics/Poisson‐Boltzmann strategies to compute the solvation free energy of macromolecules from molecular dynamics simulations using an explicit representation of solvent. The method reproduces well the free energy of solvation of standard amino acid side chains, small peptides, and proteins. The use of a fully discrete representation of solvent avoids the possible problems of continuum models to represent the solvation of systems containing tightly bound water molecules. Proteins 2004. © 2004 Wiley‐Liss, Inc.
Is allostery an intrinsic property of all dynamic proteins?
Authors: Gunasekaran K. , Ma Buyong , Nussinov Ruth
Published: July 2004

Allostery involves coupling of conformational changes between two widely separated binding sites. The common view holds that allosteric proteins are symmetric oligomers, with each subunit existing in “at least” two conformational states with a different affinity for ligands. Recent observations such as the allosteric behavior of myoglobin, a classical example of a nonallosteric protein, call into question the existing allosteric dogma. Here we argue that all (nonfibrous) proteins are potentially allosteric. Allostery is a consequence of re‐distributions of protein conformational ensembles. In a nonallosteric protein, the binding site shape may not show a concerted second‐site change and enzyme kinetics may not reflect an allosteric transition. Nevertheless, appropriate ligands, point mutations, or external conditions may facilitate a population shift, leading a presumably nonallosteric protein to behave allosterically. In principle, practically any potential drug binding to the protein surface can alter the conformational redistribution. The question is its effectiveness in the redistribution of the ensemble, affecting the protein binding sites and its function. Here, we review experimental observations validating this view of protein allostery. Proteins 2004. © 2004 Wiley‐Liss, Inc.
Differentiable and algebroid cohomology, Van Est isomorphisms, and characteristic classes
Authors: Crainic Marius
Published: July 2004

In the first section we discuss Morita invariance of differentiable/algebroid cohomology. In the second section we extend the Van Est isomorphism to groupoids. As a first application we clarify the connection between differentiable and algebroid cohomology (proved in degree 1, and conjectured in degree 2 by Weinstein-Xu [50]). As a second application we extend Van Ests argument for the integrability of Lie algebras. Applied to Poisson manifolds, this immediately implies the integrability criterion of Hector-Dazord [14]. In the third section we describe the relevant characteristic classes of representations, living in algebroid cohomology, as well as their relation to the Van Est map. This extends Evens-Lu-Weinsteins characteristic class

\theta_{L}

[20] (hence, in particular, the modular class of Poisson manifolds), and also the classical characteristic classes of flat vector bundles [2, 30]. In the last section we describe applications to Poisson geometry.
Auslander-Reiten theory over topological spaces
Authors: Jørgensen Peter
Published: July 2004

Auslander-Reiten triangles and quivers are introduced into algebraic topology. It is proved that the existence of Auslander-Reiten triangles characterizes Poincaré duality spaces, and that the Auslander-Reiten quiver is a weak homotopy invariant. The theory is applied to spheres whose Auslander-Reiten triangles and quivers are computed. The Auslander-Reiten quiver over the

d

-dimensional sphere turns out to consist of

d-1

copies of

{\mathbb Z} A_{\infty}

. Hence the quiver is a sufficiently sensitive invariant to tell spheres of different dimension apart.
Axiomatic homotopy theory for operads
Authors: Berger Clemens , Moerdijk Ieke
Published: July 2004

We give sufficient conditions for the existence of a model structure on operads in an arbitrary symmetric monoidal model category. General invariance properties for homotopy algebras over operads are deduced.
An infinitesimal trace formula for the Laplace operator on compact Riemann surfaces
Authors: Golse François , Lochak Pierre
Published: July 2004

We derive an infinitesimal (or variational) version of the Selberg trace formula for compact Riemann surfaces, which gives information on the behaviour of the eigenvalues of the Laplace-Beltrami operator as the surface varies over the appropriate moduli space.
Noether's problem for dihedral 2-groups
Authors: Chu Huah , Hu Shou-Jen , Kang Ming-Chang
Published: July 2004

Let

K

be any field and

G

be a finite group. Let

G

act on the rational function field

K(x_g: \, g \in G)

by

K

-automorphisms defined by

g \cdot x_h= x _{gh}

for any

g, \, h \in G

. Denote by

K(G)

the fixed field

K(x_g: \, g \in G)^G

. Noethers problem asks whether

K(G)

is rational (= purely transcendental) over

K

. We shall prove that

K(G)

is rational over

K

if

G

is the dihedral group (resp. quasi-dihedral group, modular group) of order 16. Our result will imply the existence of the generic Galois extension and the existence of the generic polynomial of the corresponding group.
Pieri-type formulas for the non-symmetric Jack polynomials
Authors: Forrester P. J. , McAnally D. S.
Published: July 2004

In the theory of symmetric Jack polynomials the coefficients in the expansion of the

p

th elementary symmetric function

e_p(z)

times a Jack polynomial expressed as a series in Jack polynomials are known explicitly. Here analogues of this result for the non-symmetric Jack polynomials

E_\eta(z)

are explored. Necessary conditions for non-zero coefficients in the expansion of

e_p(z) E_\eta(z)

as a series in non-symmetric Jack polynomials are given. A known expansion formula for

z_i E_\eta(z)

is rederived by an induction procedure, and this expansion is used to deduce the corresponding result for the expansion of

\prod_{j=1, \, j\ne i}^N z_j \, E_\eta(z)

, and consequently the expansion of

e_{N-1}(z) E_\eta(z)

. In the general

p

case the coefficients for special terms in the expansion are presented.
Preoperative Steroid Administration: Effect on Morbidity among Patients Undergoing Intestinal Bowel Resection for Crohn’s Disease
Authors: Bruewer Matthias , Utech Markus , Rijcken Emile J.M. , Anthoni Christoph , Laukoetter Mike G. , Kersting Sabine , Senninger Norbert , Krieglstein Christian F.
Published: July 2004

Long‐term steroid therapy may predispose to increased perioperative morbidity in patients undergoing surgery with bowel anastomoses. The aim of our study was to review our data to determine if the steroid dosage is associated with the incidence of early complications after bowel resection in patients with prolonged steroid therapy for Crohn’s disease (CD). Altogether, 397 patients underwent bowel resection with primary intestinal anastomoses for CD between 1982 and 2000 in our institution. The mortality and morbidity rates, anastomotic leakage, wound infections, intraabdominal abscesses, reoperation rate, and length of postoperative hospitalization in patients who were having high‐dose (≥ 20 mg of prednisolone per day, n = 73) and low‐dose (< 20 mg prednisolone per day, n = 146) steroid therapy for more than 1 month before surgery were compared with those of patients (n = 177) who were not receiving steroids. Statistical analysis was performed using Fisher’s exact test and Student’s t‐test, with p < 0.05 considered significant. The three groups were similar in terms of gender, duration since first diagnosis, American Society of Anesthesiologists classification, and obesity. Mortality, morbidity, anastomotic leakage, wound infections, intraabdominal abscesses, reoperation rate, and average postoperative stay were not statistically different in patients with high‐dose, low‐dose, or no steroid therapy. The only factor associated with increased morbidity was a low preoperative hemoglobin level. Our results demonstrate that, in patients who are undergoing bowel resection for CD, even high‐dose prolonged preoperative systemic steroid therapy is not associated with increased postoperative complications.
Effect of Interstitial Laser Hyperthermia in a Murine Model of Colorectal Liver Metastases: Scanning Electron Microscopic Study
Authors: Muralidharan Vijayaragavan , Nikfarjam Mehrdad , Malcontenti‐Wilson Caterina , Christophi Christopher
Published: July 2004

Interstitial laser hyperthermia (ILH) is an in situ ablative technique used to treat colorectal liver metastases. The relatively high recurrence of tumor after treatment by ILH may be related to incomplete destruction. Little is known about the effectiveness of ILH for destroying tumor microvasculature. The aim of this study was to define the changes to the microvascular architecture of tumors after treatment with ILH, specifically focusing on the completeness of tumor vasculature destruction. An intrasplenic induction model of liver metastases in 4‐ to 6‐week‐old male inbred CBA mice was used. Laser hyperthermia was applied to liver and tumor tissue using a bare optical quartz fiber from a Medilas Fibertom 4100 Nd:YAG surgical laser generator. The animals underwent microvascular corrosion casting of the livers immediately after application of ILH. Microvascular casts were then prepared and studied by scanning electron microscopy. ILH produced complete, uniform destruction of the tumor microvasculature with compete hemostasis. Blood flow in vessels larger than 100 μm diameter had a relatively protective effect, although ILH was able to overcome this barrier effectively by increasing the energy applied. ILH produces complete destruction of tumor microvasculature with hemostasis. The protective effect of blood flow in larger vessels can be overcome by the appropriate use of higher energy levels.
Clinical Value of Parathyroid Scintigraphy with Technetium‐99m Methoxyisobutylisonitrile: Discrepancies in Clinical Data and a Systematic Metaanalysis of the Literature
Authors: Gotthardt Martin , Lohmann Bodo , Behr Thomas M. , Bauhofer Artur , Franzius Christiane , Schipper Meike L. , Wagner Maria , Höffken Helmut , Sitter Helmut , Rothmund Matthias , Joseph Klaus , Nies Christoph
Published: July 2004

There is a considerable discrepancy in the literature concerning the sensitivity of parathyroid scintigraphy (PS) with 99mTc‐MIBI. We therefore analyzed our own data and compared them to the literature in a metaanalysis. All patients who received 99mTc ‐MIBI scintigraphy and subsequent surgery in our department for the detection of enlarged parathyroid glands in primary (pHPT) or secondary (sHPT) hyperparathyroidism between 1991 and 1999 were included in our retrospective analysis. The results of surgery served as the gold standard. For a true positive result, the scintigraphy had to predict the exact location of parathyroid adenoma (PA) or parathyroid hyperplasia (PH). We then compared these data to the results of a nonstatistical systematic metaanalysis of the literature. Patients (178) underwent PS between 1991 and 1999; 139 were operated on and included in this study. Of these, 109 had pHPT and 30 had sHPT. The sensitivity and specificity of the PS were found to be 45% / 94% for pHPT and 39% / 40% for sHPT. Fifty‐two studies concerning PS were included in the metaanalysis. Sensitivities reported varied from 39% to > 90%. Consideration of the different possible techniques used for PS could not explain these discrepancies. Our data show that the sensitivity of PS in clinical routine may be lower than expected from the literature. Our data are consistent with other studies and with partially unpublished clinical observations from other university hospitals. We believe that a well‐designed and properly conducted prospective study is necessary to evaluate the reasons for the differences observed.
Role of Computer Analysis in Gastric Cancer Surgery: Evaluation of the WinEstimate v. 2.5 Computer Program
Authors: Omejc Mirko , Mekicar Jernej
Published: July 2004

To identify the group of patients with gastric cancer who can benefit from extensive lymphadenectomy and to offer a rational approach to lymph node dissection, it is important to know the incidence of metastases at each lymph node station. A computer program was developed for assessment of lymph node involvement and survival time in each individual case according to preoperative variables. In patients who have undergone R0 resection with D2 lymphadenectomy, differences between the individual results generated by the computer and the actual data were compared. A cutoff point of 10% in the prediction of metastases was used as a positive result. The computer program made false predictions in 9% of patients for the pN status (3% lower and 6% higher than the actual status). Computerized prediction of 5‐year survival was close to the rate calculated by the Kaplan‐Meier method (55.5% vs 56.1%). Preoperative computer analysis of patient data and tumor characteristics offers a rational approach to individualizing tumor therapy] where the extent of lymph node dissection is tailored to the type, site, and stage of the tumor, thereby minimizing the disadvantages (morbidity, mortality) associated with the extensive operative procedure.
Modification of Mesosigmoidoplasty for Nongangrenous Sigmoid Volvulus
Authors: Bach Olaf , Rudloff Udo , Post Stefan
Published: July 2004

Mesosigmoidoplasty is a nonresective procedure for nongangrenous sigmoid volvulus. It aims to correct the main pathogenetic factor of this condition, the narrow but long mesosigmoid. Although it had been demonstrated by intraoperative measurements that this has indeed achieved its purpose, recurrent volvulus has been reported after the procedure. This has raised the question of whether an operation on the mesosigmoid’s peritoneal cover alone is sufficient to maintain the change in shape. The modification presented here aims at more sustainable shortening and widening of the mesosigmoid by including all its layers in the procedure. Of 31 consecutive patients with sigmoid volvulus operated on in Malawi in East Africa, 14 had the nongangrenous variety. Twelve of them underwent modified mesosigmoidoplasty without any major perioperative complications. There was one relaparotomy following misdiagnosis of cryptic Hirschsprung’s disease and one true recurrence secondary to a technical error during the previous operation. During a follow‐up of eight patients for 4 to 8 months, there were no complaints about abdominal discomfort or changed stool habits. Thus including all layers of the mesosigmoid in the plastic procedure did not increase short‐term morbidity and in theory should be advantageous in respect to preventing recurrence. Applying it to a larger series with prolonged follow‐up seems to be justified.