bluuebunny/crossref_metadata_2025 huggingface dataset:
Rat supraspinatus tendon expresses cartilage markers with overuse
Authors: Archambault J.M. , Jelinsky S.A. , Lake S.P. , Hill A.A. , Glaser D.L. , Soslowsky L.J.
Published: February 2007

The goals of this study were to investigate the response of the rat supraspinatus tendon to overuse at the molecular level using transcriptional profiling, and to identify potential markers of tendinopathy. Adult rats were subjected to an overuse protocol that consists of downhill running (10% grade) at 17 m/min for 1 h/day, 5 days/week, for a total of either 1, 2, or 4 weeks. Another group of rats served as nonrunning time 0 controls. Transcriptional profiling was performed on the supraspinatus and patellar tendons using an Affymetrix rat genome array. A gene was considered to be differentially expressed if the p value from an ANOVA test was less than 0.01 and the difference between runners and controls was at least twofold at any time point. The supraspinatus tendon had increased expression of well‐known cartilage genes such as col2a1, aggrecan, and sox9. These genes were not regulated in the patellar tendon, an internal comparator. Few genes associated with inflammation, or angiogenesis, were differentially expressed, and no significant change in the regulation of matrix metalloproteinases was detected. The results of this study suggest that by expressing more cartilage genes, the tendon is converting toward a fibrocartilage phenotype as a result of the repetitive loading and repeated compression of the tendon as it passes through the acromial arch. © 2007 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 25:617–624, 2007
Long‐bone critical‐size defects treated with tissue‐engineered grafts: A study on sheep
Authors: Viateau Véronique , Guillemin Geneviève , Bousson Valérie , Oudina Karim , Hannouche Didier , Sedel Laurent , Logeart‐Avramoglou Delphine , Petite Hervé
Published: February 2007

Standardized particulate bone constructs, obtained by expanding autologous mesenchymal stem cells (MSCs) onto coral granules in vitro, were transplanted into long‐bone, critical‐size defects in sheep. Control experiments were also performed in which autologous bone grafts were implanted. Defect cavities were lined with a preformed vascularized membrane (induced by temporarily inserting a cement spacer for 6 weeks prior to bone construct implantation), which served as a mold keeping the engineered bone granules in place. Radiographic, histological, and computed tomographic tests performed 6 months later showed that the osteogenic abilities of the engineered construct and autograft were significantly greater than those of coral scaffold alone. No significant differences were found between the amount of newly formed bone in defects filled with coral/MSCs and those filled with autograft, yet radiological scores differed significantly between the two groups (21% and 100% healed cortices, respectively). The present study on a clinically relevant animal model provides the first evidence that standardized particulate bone constructs can be used to repair large bone defects and that their osteogenic ability approaches that of bone autograft, the bone repair benchmark. By proving feasibility, the present study makes possible the treatment of segmental bone losses with bone constructs engineered from granules, a process which is much simpler than preparing customized massive constructs using computer‐assisted techniques. Important parameters, such as the rate of scaffold resorption and the number of MSCs to be seeded on the scaffolds, need to be optimized before reaching pertinent definitive conclusions. © 2006 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 25: 741–749, 2007
Longitudinal osteotomy of lateral sacrum for malignant iliac tumor using modified threadwire saw
Authors: Osaka Shunzo , Yoshida Yukihiro , Ryu Junnosuke
Published: February 2007

A longitudinal osteotomy of lateral sacrum for malignant iliac tumors using modified threadwire saw is conducted. This procedure issignificantly wide, rapid and safe. J. Surg. Oncol. 2007;95:258–260. © 2007 Wiley‐Liss, Inc.
The predictors of microvascular invasion in candidates for liver transplantation with hepatocellular carcinoma—with special reference to the serum levels of des‐gamma‐carboxy prothrombin
Authors: Shirabe Ken , Itoh Shinji , Yoshizumi Tomoharu , Soejima Yuji , Taketomi Akinobu , Aishima Shin‐ichi , Maehara Yoshihiko
Published: February 2007

The microvascular invasion of cancer cells (mvi) is a good prognostic factor after orthotopic liver transplantation (OLT) for hepatocellular carcinoma (HCC). The aim of this study is to predict mvi in patients with HCC who were candidates for OLT. We studied 218 patients with HCC resections who had HCC without any extrahepatic metastases and vascular invasion detected during preoperative evaluation. We analyzed the clinico‐pathological data of these patients to predict the mvi presence. The mvi prediction scoring system was made and the accuracy of this system was examined using independent clinico‐pathologic factors. The size and histological grade of the tumor were significantly correlated with the mvi. The des‐gamma‐carboxy prothrombin (DCP) is a mvi predictor. The sensitivity of our mvi prediction system was 75% and the specificity was 85% in 32 patients who underwent living‐donor liver transplantations for HCC. Our study shows that besides the tumor size and histological grade, a measurement of the serum DCP levels could be a good predictor for mvi. A tumor biopsy and a preoperative measurement of DCP could improve the selection of patients with HCC for OLT. Our scoring system for mvi provides us a precise prediction of the presence of mvi. J. Surg. Oncol. 2007;95:235–240. © 2007 Wiley‐Liss, Inc.
Multiple confined‐state transitions within surface quantum dots by a piezomodulation reflectance study
Authors: Yu C. H. , Wang C. , Zhang B. , Gong Q. , Li Y. J. , Lu W. , Shen S. C.
Published: February 2007

Multiple confined‐state transitions within surface quantum dots deposited on In0.35Ga0.65As template grown on GaAs (311)B substrate, as well as signals from all other relevant portions of the samples including buried QDs, In0.35Ga0.65As template, and GaAs‐related layers, at 77 K, were obtained in a piezomodulation reflectance spectroscopy (PzR) study. The measured transition energies were accurately determined using a Gaussian lineshape fit based on the reference of PL results. Four factors caused the large energy shift (larger than 400 meV) of confined states within SQDs compared to the buried QDs. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Liquid chromatography/tandem mass spectrometry determination of organophosphorus flame retardants and plasticizers in drinking and surface waters
Authors: Bacaloni Alessandro , Cavaliere Chiara , Foglia Patrizia , Nazzari Manuela , Samperi Roberto , Laganà Aldo
Published: February 2007

A liquid chromatography/electrospray ionization tandem mass spectrometric method for analyzing organophophorus flame retardants and plasticizers in drinking and environmental waters was developed. Five alkyl phosphates, three chlorinated alkyl phosphates, two aryl phosphate and triphenylphosphine oxide were selected for this study. These compounds were extracted from water samples by a hydrophilic polymeric solid‐phase extraction cartridge. Accuracy and precision were evaluated analyzing 0.5 L of water samples spiked at concentrations of 10 and 100 ng/L for drinking water and at 300 and 1000 ng/L for river water. Except for trimethyl phosphate, analyte recoveries were better than 80%, and were not dependent on the type of aqueous matrix in which they were dissolved. At the spike levels considered, within‐day precision was between 3 and 12% for tap water and between 4 and 14% for river water, and estimated method quantification limits ranged from 0.2 to 3.9 ng/L. A short survey conducted by analyzing some river water samples (River Tiber) ascertained the presence of ten organophosphorus compounds at concentration levels ranging from a few nanograms per liter to 323 ng/L for tris(2‐butoxyethyl) phosphate. Copyright © 2007 John Wiley & Sons, Ltd.
Analysis of antitumor active OSW‐1 and its analogues by liquid chromatography coupled with electrospray and atmospheric pressure chemical ionization quadrupole mass spectrometry
Authors: Kasai Hiroko F. , Tsubuki Masayoshi , Matsuo Sohichiro , Honda Toshio
Published: February 2007

Three cholestane glycosides including OSW‐1 with antitumor activity and two new analogues with modified steroidal side chains, thienyl OSW‐1 and silylated thienyl OSW‐1, were synthesized. Analyses were performed using optimized, reversed‐phase liquid chromatography (LC) with electrospray ionization and atmospheric pressure chemical ionization quadrupole mass spectrometry (MS). The ionization mode and polarity, cone voltage, and chromatographic conditions were evaluated. The optimum LC/MS conditions to obtain valuable ions, indispensable for identifying the structures, are described. The key fragmentation pathways, which will be useful for confirming the detailed structures of steroidal glycosides, are also proposed. Copyright © 2007 John Wiley & Sons, Ltd.
Regenerative pseudo‐noise‐like (PNL) ranging sequences for deep‐space missions
Authors: Massey James L. , Boscagli Giovanni , Vassallo Enrico
Published: February 2007

Space agencies are currently considering replacing conventional ranging systems with regenerative schemes for future demanding interplanetary missions. The Consultative Committee for Space Data Systems (CCSDS) in charge of standardization among Space Agencies is studying both Pseudo‐Noise (PN) and Pseudo‐Noise‐Like (PNL) sequences and intends to generate a recommended standard (Blue Book) by 2007. The present paper treats the PNL schemes under consideration by CCSDS, with emphasis on the scrambled weighted‐voting Stiffler PNL ranging‐sequence scheme, which is proposed herein and which appears to be superior to all other PN and PNL ranging schemes. Copyright © 2007 John Wiley & Sons, Ltd.
Rapid surface functionalization of poly(ethersulphone) foils using a highly reactive oxygen‐plasma treatment
Authors: Vrlinič T. , Vesel A. , Cvelbar U. , Krajnc M. , Mozetič M.
Published: February 2007

We present a study of the oxygen‐plasma functionalization of polyethersulphone (PES). PES samples were exposed to a weakly ionized, highly dissociated oxygen plasma, with an electron temperature of 5 eV and a positive ion density of 8 × 1015 m−3, and its afterglow, in which the density of charged particles was negligibly low and the density of neutral oxygen atoms was 4 × 1021 m−3. The wettability of the samples was determined by measuring the contact angle of a water drop, while the appearance of the functional groups on the surface of the samples was determined using high‐resolution conventional XPS. The samples were saturated with surface functional groups, both in the plasma and in the afterglow region, after 1 s of treatment time. The results are explained by the high flux of oxygen atoms on the sample surface and the characteristics of the oxygen plasma. Copyright © 2007 John Wiley & Sons, Ltd.
Quantitative determination of the composition of nitrided layers on iron using AES
Authors: Vandendael I. , Sloof W. G. , Steenhaut O. , Hubin A. , Vereecken J.
Published: February 2007

Within the framework of the study of industrial nitriding of steel, AES was chosen as the principle analysis technique. In order to characterise the nitrided layers quantitatively, reliable sensitivity factors were needed. For that purpose, different reference samples containing the pure γ′‐Fe4N1−x and ε‐Fe2N1−z phases were prepared by gaseous nitriding of pure iron. The characterisation of these references by means of electron probe microanalysis (EPMA) is discussed. The first sample contained a nitrided layer with large γ′‐Fe4N1−x grains (∼30 µm) with 19.6 at.% nitrogen on top of an iron substrate. The second one contained an ε‐Fe2N1−z outer layer (∼6 µm) with 26 at.% nitrogen, on a γ′‐Fe4N1−x layer (∼4 µm) with 19.8 at.% nitrogen, created on top of an iron substrate. In this study, Fe LMM and N KLL Auger electron spectral lines were acquired on the pure γ′‐Fe4N1−x and ε‐Fe2N1−z phases of these two reference samples in order to calculate the sensitivity factors of iron and nitrogen. Different Auger intensities were considered and compared. It was decided to use the peak areas of the direct Auger electron spectral lines. The values of the sensitivity factors are 0.74 for iron and 0.33 for nitrogen. Finally, a set of three independent and well‐characterised samples containing the γ′‐Fe4N1−x and ε‐Fe2N1−z phases was used to validate the elaborated quantification procedure. Copyright © 2007 John Wiley & Sons, Ltd.
Surface analysis of particulates from laboratory hood exhaust manifold
Authors: Groenewold Gary S. , Cortez Marnie M. , Gianotto Anita K. , Gresham Garold L. , Olson John E. , Fox Robert V. , White Byron M. , Bauer William F. , Avci Recep , Deliorman Muhammedin , Williams Eric
Published: February 2007

Particulate samples collected from a laboratory ventilation manifold during routine maintenance were analyzed to determine if particulate composition had changed as a result of changes in the laboratory's atmosphere. This ventilation manifold exhausts more than 100 fume hoods. The particulate samples were analyzed using static secondary ion mass spectrometry (SIMS). The negative SIMS spectra showed abundant Cl−, NO3−, and HSO4−, consistent with the use of mineral acids in the laboratory. Cluster anions containing primarily Zn (but also other transition metals) were detected, which signaled corrosion of the manifold's galvanized steel by the volatilized acids. The most abundant ions in the cation SIMS spectra were derived from cyclohexylamine (CHA), which had been used as an antiscaling agent in the facility's boiler. Steam from the boiler, which contained CHA, was used to humidify the building air; this practice stopped in 1997. The abundances of the CHA‐derived ions were significantly lower in the samples collected in 2004 and 2006 than in the 1992 samples, indicating that the CHA is being slowly depleted. Changes in the relative abundances suggest exponential depletion from the manifold with rate constants that are on the order of 0.01 to 0.04 month−1. Published in 2007 John Wiley & Sons, Ltd.
Behavioral synergism between D1 and D2 dopamine receptors in mice does not depend on gap junctions
Authors: Nolan Eileen B. , Harrison Laura M. , Lahoste Gerald J. , Ruskin David N.
Published: February 2007

Activation of the D1 and D2 classes of dopamine receptor in the striatum synergistically promotes motor stereotypy. The mechanism of D1/D2 receptor interaction remains unclear. To investigate the involvement of electrical synaptic transmission in this phenomenon, genetic inactivation of the neuronal gap junction (GJ) protein connexin 36 and pharmacological blockade of GJs were utilized. Stereotyped motor behavior was quantified after selective activation of D1 receptors, D2 receptors, or both receptors. These patterns of activation were produced by injection of the agonist apomorphine (3.0 mg/kg) 30 min after either the D2 antagonist eticlopride (0.3 mg/kg), the D1 antagonist SCH 23390 (0.1 mg/kg) or vehicle, respectively. Mixed background C57/BL6–129SvEv mice homozygous or heterozygous for the connexin 36 “knockout” allele displayed potent synergistic interaction between D1 and D2 receptor activation, and did not differ significantly from wild‐type mice on any measure. All genotypes demonstrated long‐lasting stereotypic sniffing, chewing, and/or licking after simultaneous activation of D1 and D2 receptors, effects that were absent following selective D1 or D2 activation. Swiss‐Webster mice treated with the GJ blockers carbenoxolone (35 mg/kg), octanol (350 mg/kg) or mefloquine (50 mg/kg) also demonstrated the normal synergistic interaction between D1 and D2 receptors, although these drugs did block the grooming stimulated by selective D1 receptor activation, independently of D2 receptors. While D1 receptor‐stimulated grooming depends on GJs composed of connexins or possibly pannexins, the synergistic interaction of D1 and D2 receptors in control of stereotypy does not involve GJs. Synapse 61:279–287, 2007. © 2007 Wiley‐Liss, Inc.
Craniofacial variability index in utero: a three‐dimensional ultrasound study
Authors: Roelfsema N. M. , Hop W. C. J. , van Adrichem L. N. A. , Wladimiroff J. W.
Published: February 2007

Objective

This study was undertaken to develop a craniofacial pattern profile analysis by three‐dimensional (3D) ultrasound and to introduce a craniofacial variability index (CVI) which can assist in the evaluation of fetal facial anatomy.

Methods

Serial 3D sonographic measurements of 16 different fetal craniofacial parameters were performed at 18–34 weeks of gestation in 126 normal singleton pregnancies. In another six pregnancies complicated by fetal abnormality, a single 3D recording was obtained. The 16 measurements cover various aspects of the facial anatomy, such as width, depth and height. For each parameter, regression analysis was performed to calculate gestational age‐specific Z‐scores and normal limits for the CVI (the latter quantifies the variability between the 16 Z‐scores).

Results

The 95th percentile of normal CVI data increased from 1.08 at 18 weeks to 1.27 at 34 weeks of gestation. The CVI was situated above the 95th percentile in three out of six fetuses with abnormalities. In abnormal subjects, 2–8 of 16 parameters showed abnormal values.

Conclusions

Craniofacial pattern profile analysis and the CVI may aid in the evaluation of fetal facial anatomy. They could be a valuable tool in syndrome delineation and for distinguishing between normal and abnormal craniofacial development. Copyright © 2007 ISUOG. Published by John Wiley & Sons, Ltd.
When You Care Enough to Do Your Very Best: Genetic Counselor Experiences of Compassion Fatigue
Authors: Benoit Lacey G. , Veach Patricia McCarthy , LeRoy Bonnie S.
Published: February 2007

Compassion fatigue is a phenomenon that occurs when a caregiver feels overwhelmed by repeated empathic engagement with distressed clients (Figley, 2002). Research demonstrates its existence among nurses, physicians, and mental health professionals, but to date no published study has specifically investigated the nature and prevalence of compassion fatigue among genetic counselors. The present study was an initial attempt to identify and describe the phenomena in genetic counseling by conducting focus group interviews with 12 genetic counselors. Data analysis yielded several themes: a) compassion fatigue occurs and may compromise professional and personal functioning; b) prevalenttriggersinclude delivering bad news and difficult patient issues (e.g., terminal illness, anger, psychopathology); c) effective coping strategies include consulting with colleagues, setting boundaries, and humor; and d) risk factors include personality characteristics and traumatic memories. Training, practice, and research recommendations are provided.
Clinical Characterization and Risk Profile of Individuals Seeking Genetic Counseling for Hereditary Breast Cancer in Brazil
Authors: Palmero Edenir Inez , Ashton‐Prolla Patricia , da Rocha José Cláudio C. , Vargas Fernando Regla , Kalakun Luciane , Blom Melissa Brauner , Azevedo Sérgio J. , Caleffi Maira , Giugliani Roberto , Schüler‐Faccini Lavinia
Published: February 2007

Hereditary breast cancer (HBC) accounts for 5–10% of breast cancer cases and it significantly increases the lifetime risk of cancer. Our objective was to evaluate the sociodemographic variables, family history of cancer, breast cancer (BC) screening practices and the risk profile of cancer affected or asymptomatic at‐risk women that undergo genetic counseling for hereditary breast cancer in public Brazilian cancer genetics services. Estimated lifetime risk of BC was calculated for asymptomatic women using the Gail and Claus models. The majority of women showed a moderate lifetime risk of developing BC, with an average risk of 19.7% and 19.9% by the Gail and Claus models, respectively. The average prior probability of carrying a BRCA1/2 gene mutation was 16.7% and overall only 32% fulfilled criteria for a hereditary breast cancer syndrome as assessed by family history. We conclude that a significant number of individuals at high‐risk for HBC syndromes may not have access to the benefits of cancer genetic counseling in these centers. Contributing factors may include insufficient training of healthcare professionals, disinformation of cancer patients; difficult access to genetic testing and/or resistance in seeking such services. The identification and understanding of these barriers is essential to develop specific strategies to effectively achieve cancer risk reduction in this and other countries were clinical cancer genetics is not yet fully established.
Geschichte und Bedeutung von Functional Foods
Authors: Walter
Published: February 2007

Es wird eine Übersicht über die geschichtlichen Entwicklungen gegeben, die 1999 zu einem wissenschaftlichen Konsensus über das Konzept der Functional Foods geführt haben. Es folgt eine Beschreibung der zu erfüllenden Voraussetzungen für diese Produkte. Zur Messung der Wirkungen von Functional Foods wird insbesondere auf die Bedeutung des Einbezugs von gut messbaren biologischen Markern, die in einem direkten Zusammenhang mit der gewünschten gesundheitlichen Wirkung stehen, hingewiesen. Besondere Bedeutung hat auch der kürzlich publizierte wissenschaftlichen Konsensus über die Art und Weise der Bereitstellung der experimentellen Unterlagen, die für die Bewilligung einer Anpreisung vorbereitet werden sollten. Diese Vorschläge dienen als wichtige Unterlage bei den zur Zeit laufenden Verhandlungen über die Genehmigung von Anpreisungen bei den EU-Behörden.
Blutdrucksenkende Tripeptide aus der Milch
Authors: Nussberger
Published: February 2007

Milchfermentierung mit dem Lactobacillus helveticus LBK-16H führt zur Freisetzung der Kaseintripeptide Val-Pro-Pro und Ile-Pro-Pro. Diese Peptide hemmen die Kininase II (auch Angiotensin Converting Enzyme, ACE genannt). Wenn genügend grosse Mengen dieser Peptide in Milchgetränken über mehrere Wochen täglich eingenommen werden, sinkt der Blutdruck bei Hypertonikern geringgradig ab. Die bisher erhältlichen Milchpeptide senken den Blutdruck weniger stark als die antihypertensiven Medikamente und sind deshalb nur als begleitende und gut verträgliche Lebensstilanpassungen zur Vorbeugung und Behandlung des Bluthochdrucks einsetzbar.
Persönliche Verantwortung für den Studienerfolg
Authors: Koch Stefan
Published: February 2007

Zusammenfassung. Dieser Beitrag wendet das aus der Sozialpsychologie stammende Modell der persönlichen Verantwortung von Schlenker, Britt, Pennington, Murphy und Doherty (1994) auf das Hochschulstudium an. Es wird argumentiert, dass persönliche Verantwortung für den Studienerfolg aus den drei Dimensionen Bedeutsamkeit, Ziel- und Prozessklarheit sowie Kontrolle besteht und sich positiv auf Studienengagement und -leistungen auswirken sollte. Studie 1 mit 133 Studierenden belegt, dass sich die drei genannten Dimensionen mit einer neu entwickelten Skala empirisch unterscheiden lassen. Studie 2 mit 223 postgraduierten Studierenden zeigt, dass die Dimensionen Bedeutsamkeit sowie Ziel- und Prozessklarheit eigenständige Anteile am selbstberichteten Studienengagement und an der Examensnote des Universitätsabschlusses erklären. Für ein Ergänzungsstudium ist dies nur ansatzweise gegeben. Es wird diskutiert, welche Folgerungen sich daraus für das Zusammenwirken der drei Dimensionen persönlicher Verantwortung ergeben.
Die Entwicklung von Zielorientierungen im Fach Mathematik von der 3. bis 5. Jahrgangsstufe
Authors: Schwinger Malte , Wild Elke
Published: February 2007

Zusammenfassung. In der vorliegenden Arbeit werden bezogen auf das Fach Mathematik die Zielprofile von Schülern der dritten bis fünften Jahrgangsstufe mit Hilfe von Mixed-Rasch-Modellen ermittelt und deren längsschnittliche Entwicklung über die drei Schuljahre analysiert. Die Mixed-Rasch-Analyse ergab zwei inhaltlich interpretierbare Klassen: eine primär lern- und eine primär leistungszielorientierte. Eine Gruppe von Schülern mit multiplen Zielen wurde nicht gefunden, auch der von Nicholls (1984) postulierte Verlauf in Richtung einer zunehmenden Leistungszielorientierung zeichnete sich nicht ab. Insgesamt ist am Ende der Grundschule bzw. zu Beginn der Sekundarstufe für die Mehrheit der Schüler ein instabiles Zielprofil zu konstatieren. Die Befunde werden vor dem Hintergrund der Forschung zu multiplen Zielen und Zielprofilen diskutiert.
Deep resistivity structure of the northwest Indian Himalaya and its tectonic implications
Authors: Arora B. R. , Unsworth Martyn J. , Rawat Gautam
Published: February 2007

Long‐period magnetotelluric (MT) data were collected at 15 stations on a 250 km long profile in the northwest Indian Himalaya to study the structure of this continent‐continent collision zone. Two‐dimensional MT inversion was used to find a resistivity model that fit the data. In the upper crust low resistivity was imaged on the limbs of the Tso‐Morari dome and may originate in serpentenization or zones of graphite. The Indus Tsangpo Suture was imaged as a sub‐vertical conductive structure that dips northeast and merges with a mid‐crustal conductor. A north dipping zone of low resistivity is imaged at the top of the underthrust Indian Plate and is likely due to fluids expelled from the underthrust sedimentary rocks. North of the Indus Suture zone this layer is located at 20–25 km depth with a conductance around 3000 S. The resistivity of 5–10 Ωm can be attributed to the presence of fluids, likely partial melt or aqueous fluids. This layer is underlain by a relatively resistive Indian crust that extends from the High Himalaya to north of the Indus suture. A decrease in deep resistivity was observed at the northern end of the profile, and is similar to the structures observed further east in the region of the INDEPTH study, despite the smaller north‐south extent of the orogen in the Indian Himalaya.
Multinomial tau-leaping method for stochastic kinetic simulations
Authors: Pettigrew Michel F. , Resat Haluk
Published: February 2007

We introduce the multinomial tau-leaping (MτL) method for general reaction networks with multichannel reactant dependencies. The MτL method is an extension of the binomial tau-leaping method where efficiency is improved in several ways. First, τ-leaping steps are determined simply and efficiently using a priori information and Poisson distribution-based estimates of expectation values for reaction numbers over a tentative τ-leaping step. Second, networks are partitioned into closed groups of reactions and corresponding reactants in which no group reactant set is found in any other group. Third, product formation is factored into upper-bound estimation of the number of times a particular reaction occurs. Together, these features allow larger time steps where the numbers of reactions occurring simultaneously in a multichannel manner are estimated accurately using a multinomial distribution. Furthermore, we develop a simple procedure that places a specific upper bound on the total reaction number to ensure non-negativity of species populations over a single multiple-reaction step. Using two disparate test case problems involving cellular processes—epidermal growth factor receptor signaling and a lactose operon model—we show that the τ-leaping based methods such as the MτL algorithm can significantly reduce the number of simulation steps thus increasing the numerical efficiency over the exact stochastic simulation algorithm by orders of magnitude.
Active region temperatures of quantum cascade lasers during pulsed excitation
Authors: Tober Richard L.
Published: February 2007

Temperature changes in quantum cascade laser active regions can be accurately estimated, during pulsed excitation, by monitoring the spectral shift of laser’s longitudinal modes. Relatively small differences in the amplitude and widths of excitation current pulses yielded large, and therefore easily measurable, longitudinal mode shifts. Thus, straightforward experiments can be used estimate active region temperatures and physical parameters.
Optimization of quantum Monte Carlo wave functions by energy minimization
Authors: Toulouse Julien , Umrigar C. J.
Published: February 2007

We study three wave function optimization methods based on energy minimization in a variational Monte Carlo framework: the Newton, linear, and perturbative methods. In the Newton method, the parameter variations are calculated from the energy gradient and Hessian, using a reduced variance statistical estimator for the latter. In the linear method, the parameter variations are found by diagonalizing a nonsymmetric estimator of the Hamiltonian matrix in the space spanned by the wave function and its derivatives with respect to the parameters, making use of a strong zero-variance principle. In the less computationally expensive perturbative method, the parameter variations are calculated by approximately solving the generalized eigenvalue equation of the linear method by a nonorthogonal perturbation theory. These general methods are illustrated here by the optimization of wave functions consisting of a Jastrow factor multiplied by an expansion in configuration state functions (CSFs) for the C2 molecule, including both valence and core electrons in the calculation. The Newton and linear methods are very efficient for the optimization of the Jastrow, CSF, and orbital parameters. The perturbative method is a good alternative for the optimization of just the CSF and orbital parameters. Although the optimization is performed at the variational Monte Carlo level, we observe for the C2 molecule studied here, and for other systems we have studied, that as more parameters in the trial wave functions are optimized, the diffusion Monte Carlo total energy improves monotonically, implying that the nodal hypersurface also improves monotonically.
Accurate quantum calculations of the reaction rates for H∕D+CH4
Authors: van Harrevelt Rob , Nyman Gunnar , Manthe Uwe
Published: February 2007

In previous work [T. Wu, H. J. Werner, and U. Manthe, Science 306, 2227 (2004)], accurate quantum reaction rate calculations of the rate constant for the H+CH4→CH3+H2 reaction have been presented. Both the electronic structure calculations and the nuclear dynamics calculations are converged with respect to the basis sets employed. In this paper, the authors apply the same methodology to an isotopic variant of this reaction: D+CH4→CH3+HD. Accurate rate constants are presented for temperatures between 250 and 400K. For temperatures between 400 and 800K, they use a harmonic extrapolation to obtain approximate rate constants for H∕D+CH4. The calculations suggest that the experimentally reported rate constants for D+CH4 are about a factor of 10–20 too high. For H+CH4, more accurate experiments are available and agreement is much better: the difference is less than a factor of 2.6. The kinetic isotope effect for the H∕D+CH4 reactions is studied and compared with experiment and transition state theory (TST) calculations. Harmonic TST was found to provide a good description of the kinetic isotope effect.
Dynamics of dissociative recombination versus electron ejection in single rovibronic resonances of BH
Authors: Ricardo Viteri C. , Gilkison Andrew T. , Grant Edward R.
Published: February 2007

Optical-optical-optical triple resonance spectroscopy isolates transitions to vibrationless Rydberg states of BH with principal quantum numbers from n=7 to 50. Corresponding resonances appear in the excitation spectrum of excited boron atoms produced by the dissociative relaxation of these states. The decay to neutral products occurs on a nanosecond time scale. Yet, corresponding resonances show Fano coupling widths that approach 1cm−1. Above threshold, spontaneous ionization dominates, but line shapes match for resonances with the same electron orbital quantum numbers built on v+=0 and v+=1 cores. This striking feature-for-feature similarity in predissociation and autoionization line shapes affirms that inelastic electron-cation scattering pathways leading to electron ejection and dissociative recombination proceed through a common continuum.
Precision analog demodulation technique for open-loop Sagnac fiber optic gyroscopes
Authors: Ferreira E. C. , de Melo F. F. , Dias J. A. Siqueira
Published: February 2007

This paper presents an analog technique for the demodulation of interferometric fiber optic gyroscopes signals, based on the calculation of the mean value of the negative cycles of the measured photodetector signal from sinusoidally modulated Sagnac gyroscopes. The developed signal processing circuit was implemented and tested in a laboratory, and it was possible to detect signals as low as 5 μrad. Experimental results measured in a 890 m fiber optic coil gyroscope equipped with the developed circuit showed that the proposed circuit, when compared to the widely used and mature lock-in amplifier technique, presented a 5.1 dB higher signal-to-noise ratio. The circuit is also very stable with the temperature, since a very low drift of 0.04°∕h °C was measured in a complete gyroscope system. The Brazilian research sounding rocket VSB-30 is currently being equipped with the developed demodulator circuit.
Periodic layered waveguide with negative index of refraction
Authors: Wu Rui-xin , Zhao Tianen , Chen Ping , Xu Jie , Ji Xinyi
Published: February 2007

The authors demonstrate that a negative index of refraction can exist in a periodic layered waveguide composed of natural materials with either permittivity or permeability negative. They find that the negative index depends on component materials, their configurations, and working modes of the waveguide. In the long wave limit, the expressions of the effective permeability and permittivity of the waveguide are derived, and the requirements for negative index are given.
Observation of vertical honeycomb structure in InAlN∕GaN heterostructures due to lateral phase separation
Authors: Zhou Lin , Smith David J. , McCartney Martha R. , Katzer D. S. , Storm D. F.
Published: February 2007

The microstructure of InxAl1−xN∕GaN heterostructures (where x∼0.13–0.19), grown by molecular beam epitaxy, was investigated by transmission electron microscopy. Observations in the cross-section and plan-view geometries show evidence for lateral phase separation originating at the GaN surface that results in a vertical honeycomblike structure within the InAlN layers. The lateral dimensions of the honeycomb cells are ∼5–10nm. The vertical walls are In rich with a width of ∼1–2nm and align roughly perpendicular to ⟨112¯0⟩ and ⟨11¯00⟩ directions. The phase separation is attributed to random compositional fluctuations during the early stages of growth, possibly associated with misfit-strain relaxation.
Bulk metallic glasses: Smaller is softer
Authors: Huang Y. J. , Shen J. , Sun J. F.
Published: February 2007

The authors report on the dramatic effect of sample size on the plastic deformation capability of a Ti-based bulk metallic glass. Compared with the larger one, the smaller size glassy alloy with the same chemical composition exhibits significantly enhanced plasticity, suggesting a “smaller is softer” trend of metallic glasses. The phenomenon is attributed to the fact that the smaller size alloy, which experienced a faster cooling rate during solidification, contains a larger amount of heats of relaxation and crystallization, favoring the preferential nucleation of shear bands and thus allowing enhanced plasticity upon compressive loading.
The Change in China's State Governance and its Effects upon Urban Scale
Authors: Chung Him
Published: February 2007

In this paper I investigate how the changing role of the Chinese state has led to the reformatting of urban space. It is argued that a new rationality of governance, based on both localization and promotion of state authority, has been introduced during the era of economic reform. This dual process has reconstructed China's urban scale which was inherited from the prereform period. The implementation of city-led counties ( shi guan xian) in 1982 has provided a good example for illustration. Under this new system, cities have not only been institutionalized as administrative centers, their territory, bureaucracy, and power have also been expanded and hence a new relationship between cities and counties has been forged. These arguments are illustrated by reference to Jiangsu, one of the first provinces to initiate city-led counties.
A polyphosphate kinase 1 (
ppk1
) mutant of
Pseudomonas aeruginosa
exhibits multiple ultrastructural and functional defects
Authors: Fraley Cresson D. , Rashid M. Harunur , Lee Sam S. K. , Gottschalk Rebecca , Harrison Janine , Wood Pauline J. , Brown Michael R. W. , Kornberg Arthur
Published: February 2007

Pseudomonas aeruginosa
, of medical, environmental, and industrial importance, depends on inorganic polyphosphate (poly P) for a wide range of functions, especially survival. Mutants of PAO1 lacking poly P kinase 1, PPK1, the enzyme responsible for most poly P synthesis in
Escherichia coli
and other bacteria, are defective in motility, quorum sensing, biofilm formation, and virulence. We describe here multiple defects in the
ppk1
mutant PAOM5, including a striking compaction of the nucleoid, distortion of the cell envelope, lack of planktonic motility and exopolymer production, and susceptibility to the β-lactam antibiotic carbenicillin as well as desiccation. We propose that
P. aeruginosa
with reduced poly P levels undergoes ultrastructural changes that contribute to profound deficiencies in cellular functions.
An optimized transgenesis system for
Drosophila
using germ-line-specific φC31 integrases
Authors: Bischof Johannes , Maeda Robert K. , Hediger Monika , Karch François , Basler Konrad
Published: February 2007

Germ-line transformation via transposable elements is a powerful tool to study gene function in
Drosophila melanogaster
. However, some inherent characteristics of transposon-mediated transgenesis limit its use for transgene analysis. Here, we circumvent these limitations by optimizing a φC31-based integration system. We generated a collection of lines with precisely mapped
attP
sites that allow the insertion of transgenes into many different predetermined intergenic locations throughout the fly genome. By using regulatory elements of the
nanos
and
vasa
genes, we established endogenous sources of the φC31 integrase, eliminating the difficulties of coinjecting integrase mRNA and raising the transformation efficiency. Moreover, to discriminate between specific and rare nonspecific integration events, a
white
gene-based reconstitution system was generated that enables visual selection for precise
attP
targeting. Finally, we demonstrate that our chromosomal
attP
sites can be modified
in situ
, extending their scope while retaining their properties as landing sites. The efficiency, ease-of-use, and versatility obtained here with the φC31-based integration system represents an important advance in transgenesis and opens up the possibility of systematic, high-throughput screening of large cDNA sets and regulatory elements.
Nap1: taking a closer look at a juggler protein of extraordinary skills
Authors: Zlatanova Jordanka , Seebart Corrine , Tomschik Miroslav
Published: February 2007

The nucleosome assembly protein Nap1 is used extensively in the chromatin field to reconstitute nucleosomal templates for structural and functional studies. Beyond its role in facilitating experimental investigation of nucleosomes, the highly conserved Nap1 is one of the best‐studied members of the histone chaperone group. Here we review its numerous functions, focusing mainly on its roles in assembly and disassembly of the nucleosome particle, and its interactions with chromatin remodeling factors. Its presumed role in transcription through chromatin is also reviewed in detail. An attempt is made to clearly discriminate between fact and fiction, and to formulate the unresolved questions that need further attention. It is beyond doubt that the numerous, seemingly unrelated functions of this juggler protein have to be precisely channeled, coordinated, and regulated. Why nature endowed this specific protein with so many functions may remain a mystery. We are aware of the enormous challenge to the scientific community that understanding the mechanisms underlying these activities presents.—Zlatanova, J., Seebart, C., Tomschik, M. Nap1: taking a closer look at a juggler protein of extraordinary skills. FASEB J. 21, 1294–1310 (2007)
Molecular regulation of visual system development: more than meets the eye
Authors: Harada Takayuki , Harada Chikako , Parada Luis F.
Published: February 2007

Vertebrate eye development has been an excellent model system to investigate basic concepts of developmental biology ranging from mechanisms of tissue induction to the complex patterning and bidimensional orientation of the highly specialized retina. Recent advances have shed light on the interplay between numerous transcriptional networks and growth factors that are involved in the specific stages of retinogenesis, optic nerve formation, and topographic mapping. In this review, we summarize this recent progress on the molecular mechanisms underlying the development of the eye, visual system, and embryonic tumors that arise in the optic system.
ClpS modulates but is not essential for bacterial N-end rule degradation
Authors: Wang Kevin H. , Sauer Robert T. , Baker Tania A.
Published: February 2007

In eubacteria, the ClpS adaptor has been proposed to be essential for degradation of N-end rule substrates by the AAA+ protease ClpAP. To test this model, we assayed degradation of substrates bearing N-end rule sequences isolated in a genetic screen for efficient degradation tags. ClpS was not vital for degradation in vivo but rather stimulated turnover in a sequence-specific manner. Although ClpS substantially enhanced degradation of N-end substrates at low substrate concentrations in vitro, it suppressed the degradation rate when substrate was saturating. Thus, we conclude that ClpAP recognizes N-end rule substrates directly, whereas ClpS modulates this degradation pathway.
Anaesthetic management of insulinoma
Authors: CHARI PRAMILA , PANDIT S. K. , KATARIA R. N. , SINGH HARIWIR , BAHETI D. K. , WIG JYOTSNA
Published: February 2007

The anaesthetic management of two cases of insulinoma treated by distal pancreatectomy is presented. Stress is laid on pre‐operative and intra‐operative glucose administration in sufficiently high quantity.

Pre‐operative corticosteroid therapy is better avoided. Dextrose infusion should be stopped soon after removal of the tumour to prevent excessive hyperglycemic response in the postoperative period.

Methoxyflurane was used because it tends to raise the blood sugar level. Pancuronium bromide was preferred because of the stable cardiovascular conditions it produces.
Subarachnoid injection during extradural analgesia for labour using 2‐chloroprocaine
Authors: ALLEN P. R. , JOHNSON R. W.
Published: February 2007

An obstetric patient had a subarachnoid block during attempted extradural analgesia for labour. The sensory block extended to TI and was accompanied by hypotension. The analgesia lasted 3 hr, after which sensory and motor function recovered quickly. The local anaesthetic agent used was 2% 2‐chloroprocaine.
Epidural analgesia for elective Caesarean section
Authors: THORBURN J. , MOIR D. D.
Published: February 2007

A technique is described of epidural anaesthesia for elective Caesarean section which has a 98% success rate, and an acceptably low incidence of intra‐operative pain. The essentials of the technique are to produce and maintain complete sensory block front S5 to T6, employing a two‐stage injection of bupivacaine 0–5% (mean dose 23 ml) and the use of gravity to ensure sacral block. Despite the use of pre‐operative fluid loading and avoidance of caval occlusion, transitory hypotension occurred in 16% of patients. Vomiting, which occurred in 18% of patients, is a minor but distressing complication.
Coronary disease and anaesthesia
Authors: FLETCHER ROGER
Published: February 2007

The anaesthetic care of patients with coronary artery disease can probably be improved. The goal is to maintain a favourable myocardial oxygen supply/demand ratio. This may necessitate the use of β‐blockade and vasodilators, or alternatively perhaps halothane, in order to reduce arterial pressure and heart rate, and thereby reduce myocardial work. Normoventilation and adequate analgesia help to prevent increases in peripheral resistance. Careful ECG monitoring may reveal ischaemia or left ventricular strain, which should be regarded as an indication to reduce myocardial work.
Rabies encephalitis: management in a district general hospital ICU
Authors: CUNDY J.M.
Published: February 2007

A brief description is given of the treatment of a case of rabies encephalitis. The problems of isolation and monitoring are described with a view to the provision of optimum care for future cases in the United Kingdom.
Postoperative convulsions due to iophendylate (Myodil)
Authors: JONES D.F.
Published: February 2007

A previously fit 58‐year‐old man underwent lumbar laminectomy following a myelogram. Postoperatively convulsions occurred. He was successfully treated and made a complete recovery. Large quantities of intracranial iophendylate (Myodil) were seen on postoperative skull X‐rays. In the absence of other likely causes, a diagnosis of iophendylate‐induced encephalopathy was made. A review of the aetiology of convulsions in the intra‐ and postoperative period is presented.
Epidural analgesia for uneventful labour
Authors: Morgan B.M. , Rehor S. , Lewis P.J.
Published: February 2007

The effectiveness of epidural analgesia for uneventful labour was assessed in 200 patients who had received epidural blocks performed by trainee anaesthetists and whose subsequent management was supervised by trainee midwives. Although 88% of mothers were satisfied with the pain relief, only 46% had a completely painless labour after insertion of the epidural block. The major cause of pain was due to delay by attendant midwives in repeating the dose of local anaesthetic.

Epidural analgesia is potentially highly effective, but in practice this seems to be related to the expertise of the anaesthetists and the midwives. Almost half the deliveries were instrumental, the proportion being greater for primipara, and this was presumably related to the epidural analgesia.
Postoperative pain relief using epidural morphine
Authors: GRAHAM JOAN L. , KING R. , McCAUGHEY W.
Published: February 2007

In postoperative prostatectomy patients, morphine 2 mg in 10 ml 0·9% saline was given epidurally for pain relief and its effectiveness compared with bupivacaine. The duration of analgesia with morphine was approximately double that with bupivacaine. Significant hypotension occurred in approximately 5% of the patients receiving bupivacaine, but was not seen following morphine. These seem to be important advantages in the use of morphine by this route.
Amnesic action of midazolam
Authors: DUNDEE J.W. , WILSON D.B.
Published: February 2007

Midazolam 5 mg, a water‐soluble benzodiazepine, given intravenously to adults had a maximum effect of impairing memory for postcards shown between 2 and 5 min after injection. This effect has mainly passed off in 20 min.
Mechanical ventilation for pulmonary disease
Authors: PETHERAM IAN S. , BRANTHWAITE M.A.
Published: February 2007

Between 1972 and 1977, 91 patients received mechanical ventilation for pulmonary disorders. Forty‐nine (53.8%) left hospital and 35 of these survived for at least 1 year. Nineteen of 23 asthmatic patients survived. Cerebral damage following cardiorespiratory arrest precluded successful outcome in three of the four who died. In those with chronic lung diseases, patients with chronic bronchitis fared best; outcome was poor in those with emphysema, bronchiectasis and pulmonary fibrosis often despite trivial precipitating causes of respiratory failure. Mortality was high in patients with pneumonia even if immunologically normal.