bluuebunny/crossref_metadata_2025 huggingface dataset:
Generation of GABAergic and dopaminergic interneurons from endogenous embryonic olfactory bulb precursor cells
Authors: Vergaño-Vera Eva , Yusta-Boyo María J. , de Castro Fernando , Bernad Antonio , de Pablo Flora , Vicario-Abejón Carlos
Published: October 2006

During the embryonic period, many olfactory bulb (OB) interneurons arise in the lateral ganglionic eminence (LGE) from precursor cells expressing Dlx2,Gsh2 and Er81 transcription factors. Whether GABAergic and dopaminergic interneurons are also generated within the embryonic OB has not been studied thoroughly. In contrast to abundant Dlx2 and Gsh2 expression in ganglionic eminences (GE), Dlx2 and Gsh2 proteins are not expressed in the E12.5-13.5 mouse OB, whereas the telencephalic pallial domain marker Pax6 is abundant. We found GABAergic and dopaminergic neurons originating from dividing precursor cells in E13.5 OB and in short-term dissociated cultures prepared from the rostral half of E13.5 OB. In OB cultures, 22% of neurons were GAD+,of which 53% were Dlx2+, whereas none expressed Gsh2. By contrast,70% of GAD+ cells in GE cultures were Dlx2+ and 16%expressed Gsh2. In E13.5 OB slices transplanted with EGFP-labeled E13.5 OB precursor cells, 31.7% of EGFP+ cells differentiated to GABAergic neurons. OB and LGE precursors transplanted into early postnatal OB migrated and differentiated in distinct patterns. Transplanted OB precursors gave rise to interneurons with dendritic spines in close proximity to synaptophysin-positive boutons. Interneurons were also abundant in differentiating OB neural stem cell cultures; the neurons responded to the neurotrophin Bdnf and expressed presynaptic proteins. In vivo, the Bdnf receptor TrkB colocalized with synaptic proteins at the glomeruli. These findings suggest that, in addition to receiving interneurons from the LGE, the embryonic OB contains molecularly distinct local precursor cells that generate mature GABAergic and dopaminergic neurons.
Noninvasive Prenatal Detection of Fetal Trisomy 18 by Epigenetic Allelic Ratio Analysis in Maternal Plasma: Theoretical and Empirical Considerations
Authors: Tong Yu K , Ding Chunming , Chiu Rossa WK , Gerovassili Ageliki , Chim Stephen SC , Leung Tak Y , Leung Tse N , Lau Tze K , Nicolaides Kypros H , Lo YM Dennis
Published: October 2006

Background: The discovery of cell-free fetal DNA in maternal plasma has opened up new possibilities for noninvasive prenatal diagnosis. However, the use of maternal plasma fetal DNA for the direct detection of fetal chromosomal aneuploidies has not been reported. We postulate that the aneuploidy status of a fetus could be revealed by an epigenetic allelic ratio approach, i.e., by analyzing the allelic ratio of a single-base variation present within DNA molecules exhibiting a placental-specific epigenetic signature in maternal plasma.

Methods: Placental-derived fetal-specific unmethylated maspin (SERPINB5) promoter sequences on human chromosome 18 were detectable in placental–maternal DNA mixtures and in maternal plasma by bisulfite modification followed by methylation-specific PCR (MSP) and primer extension. The ratios between the extension products of the 2 alleles were calculated for heterozygous placentas, placental–maternal blood cell DNA mixtures, and maternal plasma samples. The allelic ratios were compared between pregnancies carrying trisomy 18 and euploid fetuses.

Results: The epigenetic allelic ratios of all tested trisomy 18 samples deviated from the reference range obtained from euploid samples (placental DNA, 1.135 to 2.052; placental–maternal DNA mixtures, 1.170 to 1.985; maternal plasma, 0.330 to 3.044; without skew correction on the raw mass spectrometric data). A theoretical model was established and validated that predicted that a minimum of 200 copies of genomic DNA after bisulfite conversion were required for distinguishing euploid and aneuploid fetuses with confidence.

Conclusion: Epigenetic allelic ratio analysis of maternal plasma DNA represents a promising approach for noninvasive prenatal diagnosis of fetal chromosomal aneuploidies.
ScaleNet – Converged Networks of the Future (ScaleNet – Konvergente Netze der Zukunft)
Authors: Siebert Matthias , Xu B. , Grigat M. , Weis E. , Bayer N. , Sivchenko D. , Banniza T. , Wünstel K. , Wahl S. , Sigle R. , Keller Ralf , Dekorsy A. , Bauer M. , Soellner M. , Eichinger J. , Fan C. , Pittmann F. , Kühne R. , Schläger M. , Baumgart I. , Bless R. , Stefanov S.
Published: October 2006

This article provides an overview of ongoing research within the framework ScaleNet. Considering IP as the basis transport scheme, the wireless and the wireline world have just started to move towards each other. ScaleNet is pushing this development by evolving a new system concept and by developing technologies for Fixed & Mobile Convergence.
Die QoS Lösung des MUSE Projekts – Europa definiert das Breitbandnetz der nächsten Generation (The QoS Solution of the MUSE Project)
Authors: Foglar Andreas
Published: October 2006

Das Integrierte EU Projekt MUSE des 6. Rahmenprogramms hat ein QoS Konzept für Zugangsnetze erarbeitet. Der neue Ansatz, den Paketjitter als Unterscheidung der QoS Klassen zu verwenden, erweist sich als so vorteilhaft, dass die Lösung ein Standard werden könnte.
Enantioselective Catalysis over Chiral Imidazolidin‐4‐one Immobilized on Siliceous and Polymer‐Coated Mesocellular Foams
Authors: Zhang Yugen , Zhao Lan , Lee Su Seong , Ying Jackie Y.
Published: October 2006

A highly efficient and enantioselective organocatalyst, imidazolidin‐4‐one, has been successfully immobilized on siliceous MCF and polymer‐coated MCF. The resulting heterogenized catalyst demonstrated excellent catalytic performance and recyclability for Friedel–Crafts alkylation and Diels–Alder cycloaddition. The performance of the supported catalysts in relation to the surface environment of siliceous MCF was examined. It was found that partially pre‐capping the MCF with TMS groups enabled us to attain well‐dispersed catalysts on the siliceous support with optimal performance. We have also developed a polymer‐coated MCF, which retained the porous structure of MCF without the surface silanol groups. High reactivity and excellent recyclability were achieved by the organocatalyst immobilized on polymer‐coated MCF.
Productivity of Selective Electroenzymatic Reduction and Oxidation Reactions: Theoretical and Practical Considerations
Authors: Ruinatscha Reto , Höllrigl Volker , Otto Katja , Schmid Andreas
Published: October 2006

The volumetric productivities, final product concentration and total process times, of electroenzymatic processes comprising reductive electrochemical cofactor regeneration coupled to dehydrogenase or oxygenase catalyzed redox reactions determine process performance. Exemplified for the production of fine chemicals, operational windows were defined to consider these parameters. This theoretical approach allows the identification of limiting process parameters and promising process developments. Several biocatalytic processes for syntheses of specialty chemicals are already in a performance range of technical relevance. Electroenzymology thus evolved to a strong additional technology in the toolbox of biocatalysis and organic chemistry.
Terminal Alkyne Metathesis: A Further Step Towards Selectivity
Authors: Coutelier Olivier , Mortreux André
Published: October 2006

Terminal alkyne metathesis has been improved by addition of quinuclidine as an external ligand to the (t‐BuO)3WCBu‐t carbyne complex, giving a yield of 80 % during hept‐1‐yne metathesis. Extension of this system to the co‐metathesis of terminal and disubstituted alkynes affords the expected cross‐reaction products.
Enzymatic Conversion of Unnatural Amino Acids by Yeast D‐Amino Acid Oxidase
Authors: Caligiuri Antonio , D'Arrigo Paola , Rosini Elena , Tessaro Davide , Molla Gianluca , Servi Stefano , Pollegioni Loredano
Published: October 2006

Unnatural amino acids, particularly synthetic α‐amino acids, are becoming crucial tools for modern drug discovery research. In particular, this application requires enantiomerically pure isomers. In this work we report on the resolution of racemic mixtures of the amino acids d,l‐naphthylalanine and d,l‐naphthylglycine by using a natural enzyme, D‐amino acid oxidase from the yeast Rhodotorula gracilis. A significant improvement of the bioconversion is obtained using a single‐point mutant enzyme designed by a rational approach. With this D‐amino acid oxidase variant the complete resolution of all the unnatural amino acids tested was obtained: in this case, the bioconversion requires a shorter time and a lower amount of biocatalyst compared to the wild‐type enzyme. The simultaneous production of the corresponding α‐keto acid, a possible precursor of the amino acid in the L‐form, improves the significance of the procedure.
Facile Preparation of an Enzyme‐Immobilized Microreactor using a Cross‐Linking Enzyme Membrane on a Microchannel Surface
Authors: Honda Takeshi , Miyazaki Masaya , Nakamura Hiroyuki , Maeda Hideaki
Published: October 2006

The enzyme microreactor has considerable potential for use in biotechnological syntheses and analytical studies. Simplifying the procedure of enzyme immobilization in a microreactor is attractive, and it is achievable by utilizing enzyme immobilization techniques and taking advantage of the characteristics of microfluidics. We previously developed a facile and inexpensive preparation method for an enzyme‐immobilized microreactor. The immobilization of enzymes can be achieved by the formation of an enzyme‐polymeric membrane on the inner wall of the microchannel through cross‐linking polymerization in a laminar flow. However, this method is unsuitable for use in conjunction with electronegative enzymes. Therefore, a novel preparation method using poly‐L‐lysine [poly(Lys)] as a booster and an adjunct for the effective polymerization of electronegative enzymes was developed in this study. Using aminoacylase as a model for an electronegative enzyme, the reaction conditions for the enzyme‐cross‐linked aggregation were optimized. On the basis of the determined conditions, an acylase‐immobilized tubing microreactor was successfully prepared by cross‐linking polymerization in a concentric laminar flow. The resulting microreactor showed a higher stability against heat and organic solvents compared to those of the free enzyme. The developed method using poly(Lys) was applicable to various enzymes with low isoelectric points, suggesting that this microreactor preparation utilizing a cross‐linked enzyme in a laminar flow could be expanded to microreactors in which a broad range of functional proteins are employed.
Organization development in the profit sector: Lessons learned
Authors: Woodman Richard W. , Muse William V.
Published: October 2006

How can community colleges profit from the experiences of business firms in implementing organizational development programs?
Sustained increased risk of adverse cardiac events over 5 years after implantation of gold‐coated coronary stents
Authors: Pache Jürgen , Dibra Alban , Schaut Christian , Schühlen Helmut , Dirschinger Josef , Mehilli Julinda , Kastrati Adnan , Schömig Albert
Published: October 2006

Objective: To study the 5‐year outcome of patients treated with gold‐coated stent placement. Background: We have previously shown in the setting of a randomized trial that gold‐coated stents are associated with worse mid‐term outcome, mainly because of an increased risk of restenosis, compared to uncoated stents. The long‐term outcome and, in particular, mortality risk after implantation of gold‐coated stents are not known. Methods: A total of 731 patients with symptoms or signs of ischemia received randomly either a gold‐coated (n = 367) or an uncoated steel stent (n = 364) of identical design. Patients were clinically followed‐up at 1 and 5 years. The primary endpoint of the study was the composite of major cardiac events (death, myocardial infarction, or target vessel revascularization (TVR)). The incidence of death was a secondary endpoint. Results: Five‐year follow‐up was available in 97.5% of the patients. The composite of death, myocardial infarction, or TVR occurred in 51% of the patients treated with gold‐coated stents and 40% of the patients treated with uncoated stents (P = 0.005). Of note, there was a marked increase in the absolute difference in mortality between patients in the gold‐coated and uncoated stent groups, from 1.6% at 1 year to 4.9% after 5‐year follow‐up (P = 0.09). A multivariate analysis showed that gold‐coated stent implantation was independently associated with 5‐year mortality (hazard ratio, 1.46; 95% confidence interval, 1.02–2.09; P = 0.04). Conclusions: Gold‐coated stents are associated with a sustained increased overall risk for major cardiac events, and notably, they may increase the long‐term mortality risk. © 2006 Wiley‐Liss, Inc.
Late migration of a Sideris buttoned device for occlusion of atrial septal defect
Authors: Cotts Timothy , Strouse Peter J. , Graziano Joseph N.
Published: October 2006

We describe a 17‐year‐old patient with an atrial septal defect who underwent device closure with a second generation Sideris buttoned device at 4 years of age. She presented 13 years after the procedure with the acute onset of chest discomfort, at which time a chest radiograph showed migration of the wire of the right atrial counter‐occluder to the lateral aspect of the right atrial wall, with an associated right atrial perforation. The patient underwent uneventful surgical device retrieval and atrial septal defect closure. Late migration of a portion of the Sideris buttoned device can occur, suggesting the need for continued follow up, and a high index of suspicion for device failure should a patient become symptomatic. © 2006 Wiley‐Liss, Inc.
Achieving fine‐grained access control in virtual organizations
Authors: Zhang N. , Yao L. , Nenadic A. , Chin J. , Goble C. , Rector A. , Chadwick D. , Otenko S. , Shi Q.
Published: October 2006

In a virtual organization environment, where services and data are provided and shared among organizations from different administrative domains and protected with dissimilar security policies and measures, there is a need for a flexible authentication framework that supports the use of various authentication methods and tokens. The authentication strengths derived from the authentication methods and tokens should be incorporated into an access‐control decision‐making process, so that more sensitive resources are available only to users authenticated with stronger methods. This paper reports our on‐going efforts in designing and implementing such a framework to facilitate multi‐level and multi‐factor adaptive authentication and authentication strength linked fine‐grained access control. The proof‐of‐concept prototype is designed and implemented in the Shibboleth and PERMIS infrastructures, which specifies protocols to federate authentication and authorization information and provides a policy‐driven, role‐based, access‐control decision‐making capability. Copyright © 2006 John Wiley & Sons, Ltd.
Synthesis and Structural Characterization of Sandwich‐Type Keggin‐γ‐Lacunary Silicotungstates with an Open Wells–Dawson‐Like Structure
Authors: Liu Hongsheng , Peng Jun , Su Zhongnin , Chen Yanhui , Dong Baoxia , Tian Aixiang , Han Zhangang , Wang Enbo
Published: October 2006

Three novel [γ‐SiW10O36]8– dimers, [{K(H2O)}2{(μ3‐H2O)M(H2O)}(γ‐Si2W20O70)]8– (M = Mn2+, 1; Co2+, 2; Ni2+, 3), are isolated from an aqueous acidic medium without isomerization, which is different from most reactions of [γ‐SiW10O36]8– with first‐row transition metals. They are isomorphous and crystallize in the orthorhombic system, space group Pnma. These species are the first examples of imidazole–potassium mixed salts of Keggin‐γ‐type dimers having an analogous open structure related to the Wells–Dawson anionic cluster. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)
The Reaction of Hyperforin with Hydride Reducing Agents
Authors: Verotta Luisella , Sterner Olov , Appendino Giovanni , Bombardelli Ezio , Pilati Tullio
Published: October 2006

As part of a study aimed at generating analogues of hyperforin (1), the reaction of this prenylated phloroglucinol with various hydride reducing agents was investigated. Hyperforin contains two β‐dicarbonyl systems, one of which is non‐enolizable, and it was interesting to assess the relative reactivity of these structural elements in the highly compact framework of the natural product. Depending on the reducing agent employed, a surprising range of compounds could be obtained, sometimes in synthetically useful yields. The stereochemistry of the LiAlH4‐reduced product was secured by X‐ray analysis and served as a base for elucidating the configuration of a series of reduced and deoxygenated analogues obtained with other reducing agents. The chemoselectivity observed in these reactions is apparently the result of a combination of metal‐chelation and hydrogen‐bonding effects. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)
Hippocampal contributions to recollection in retrograde and anterograde amnesia
Authors: Gilboa Asaf , Winocur Gordon , Rosenbaum R. Shayna , Poreh Amir , Gao Fuqiang , Black Sandra E. , Westmacott Robyn , Moscovitch Morris
Published: October 2006

Lesions restricted to the hippocampal formation and/or extended hippocampal system (hippocampal formation, fornix, mammillary bodies, and anterior thalamic nuclei) can disrupt conscious recollection in anterograde amnesia, while leaving familiarity‐based memory relatively intact. Familiarity may be supported by extra‐hippocampal medial temporal lobe (MTL) structures. Within‐task dissociations in recognition memory best exemplify this distinction in anterograde amnesia. The authors report for the first time comparable dissociations within recognition memory in retrograde amnesia. An amnesic patient (A.D.) with bilateral fornix and septal nuclei lesions failed to recognize details pertaining to personal past events only when recollection was required, during recognition of episodic details. His intact recognition of generic and semantic details pertaining to the same events was ascribed to intact familiarity processes. Recollective processes in the controls were reflected by asymmetrical Receiver's Operating Characteristic curves, whereas the patient's Receiver's Operating Characteristic was symmetrical, suggesting that his inferior recognition performance on episodic details was reliant on familiarity processes. Anterograde and retrograde memories were equally affected, with no temporal gradient for retrograde memories. By comparison, another amnesic person (K.C.) with extensive MTL damage (involving extra‐hippocampal MTL structures in addition to hippocampal and fornix lesions) had very poor recognition and no recollection of either episodic or generic/semantic details. These data suggest that the extended hippocampal system is required to support recollection for both anterograde and retrograde memories, regardless of their age. © 2006 Wiley‐Liss, Inc.
Fertility among female hodgkin lymphoma survivors attempting pregnancy following ABVD chemotherapy
Authors: Hodgson David C. , Pintilie Melania , Gitterman Leah , DeWitt Beth , Buckley Carol‐Ann , Ahmed Sameera , Smith Katherine , Schwartz Amanda , Tsang Richard W. , Crump Michael , Wells Woodrow , Sun Alexander , Gospodarowicz Mary K.
Published: October 2006

Although ABVD (doxorubicin, bleomycin, vinblastine, dacarbazine) chemotherapy is infrequently associated with premature amenorrhea, little is known about the success rate of women attempting pregnancy following ABVD. In the present study females treated for HL with ABVD chemotherapy without pelvic radiation therapy (RT) and who were alive without relapse ≥3 years after treatment were identified from a clinical database and screened for inclusion. Using a standardized questionnaire, we determined the pregnancy rate (i.e. time‐to‐pregnancy, TTP) among survivors who had become pregnant, tried to become pregnant, or who had been sexually active for over 2 months without using contraception at any time following ABVD. The cumulative incidence of pregnancy was calculated using the Kaplan–Meier method. Cox proportional hazards models were constructed to compare the pregnancy rate among HL survivors to that reported by friend or sibling controls. Thirty‐six female HL survivors, who had attempted pregnancy after ABVD treatment, and 29 controls, completed the survey. Eighteen patients (50%) received 2–4 cycles of ABVD, 16 (44%) received 4–6 cycles, and 2 (6%) received >6 cycles. The median TTP among both HL survivors and controls was 2.0 months. The 12‐month pregnancy rates were 70% and 75%, respectively. The fertility ratio (FR) for HL survivors versus controls was 0.94 (95%CI = 0.53–1.66; p = 0.84) after adjusting for age and frequency of intercourse (where FR < 1 indicates subfertility). Age at treatment and the number of cycles of chemotherapy were not associated with pregnancy rate among HL survivors. Female HL patients who had survived without recurrence ≥3 years and who had attempted pregnancy after ABVD did not experience significant sub‐fertility. Copyright © 2006 John Wiley & Sons, Ltd.
Refined chloride mass‐balance method and its application in Saudi Arabia
Authors: Subyani Ali , Şen Zekai
Published: October 2006

The rainfall and infiltration elements of the hydrological cycle in arid regions are characterized by temporal and spatial variations that are random and sporadic. Consequently, the chloride concentration in rainfall has a similar behaviour. Despite this, the classical chloride mass balance (CMB) approach only employs arithmetic and weighted averages for recharge estimation. In this paper, the classical CMB method is modified by taking into account some perceived deficiencies in the methodology. The modified CMB method takes into consideration additional statistical parameters, namely variances and the correlation coefficient between variables concerned based on the application of the perturbation method. Strategic aquifer planning in the Kingdom of Saudi Arabia requires a quick method for estimating groundwater recharge in order to determine the temporal management of available water resources. To demonstrate the difference between the classical and the refined CMB methods, both were applied to a representative basin, i.e. Wadi Yalamlam, in the western part of Saudi Arabia. Based on the refined calculations, recharge to groundwater is found to be 11% of the effective annual rainfall. This refined method provides higher recharge rates because it takes into account the actual variability in the variables concerned and can, thus, improve the accuracy of future groundwater recharge estimation studies. Copyright © 2006 John Wiley & Sons, Ltd.
Groundwater recharge in the Akaki catchment, central Ethiopia: evidence from environmental isotopes (δ18O, δ2H and 3H) and chloride mass balance
Authors: Demlie Molla , Wohnlich Stefan , Gizaw Birhanu , Stichler Willibald
Published: October 2006

Recharge patterns, possible flow paths and the relative age of groundwater in the Akaki catchment in central Ethiopia have been investigated using stable environmental isotopes δ18O and δ2H and radioactive tritium (3H) coupled with conservative chloride measurements. Stable isotopic signatures are encoded in the groundwater solely from summer rainfall. Thus, groundwater recharge occurs predominantly in the summer months from late June to early September during the major Ethiopian rainy season. Winter recharge is lost through high evaporation–evapotranspiration within the unsaturated zone after relatively long dry periods of high accumulated soil moisture deficits. Chloride mass balance coupled with the isotope results demonstrates the presence of both preferential and piston flow groundwater recharge mechanisms. The stable and radioactive isotope measurements further revealed that groundwater in the Akaki catchment is found to be compartmentalized into zones. Groundwater mixing following the flow paths and topography is complicated by the lithologic complexity. An uncommon, highly depleted stable isotope and zero‐3H groundwater, observed in a nearly east–west stretch through the central sector of the catchment, is coincident with the Filwoha Fault zone. Here, deep circulating meteoric water has lost its isotopic content through exchange reactions with CO2 originating at deeper sources or it has been recharged with precipitation from a different rainfall regime with a depleted isotopic content. Copyright © 2006 John Wiley & Sons, Ltd.
Effects of land‐use changes on hydrological processes in the middle basin of the Heihe River, northwest China
Authors: Wang Genxu , Liu Jingqi , Kubota Jumpei , Chen Ling
Published: October 2006

The effects of land‐use changes on the runoff process in the midstream plain of this arid inland river basin are a key factor in the rational allocation of water resources to the middle and lower reaches. The question is whether and by how much increasingly heavy land use impacts the hydrological processes in such an arid inland river basin. The catchment of the Heihe River, one of the largest inland rivers in the arid region of northwest China, was chosen to investigate the hydrological responses to land‐use change. Flow duration curves were used to detect trends and variations in runoff between the upper and lower reaches. Relationships among precipitation, upstream runoff, and hydrological variables were identified to distinguish the effects of climatic changes and upstream runoff changes on middle and downstream runoff processes. The quantitative relation between midstream cultivated land use and various parameters of downstream runoff processes were analysed using the four periods of land‐use data since 1956. The Volterra numerical function relation of the hydrological non‐linear system response was utilized to develop a multifactor hydrological response simulation model based on the three factors of precipitation, upstream runoff, and cultivated land area. The results showed that, since 1967, the medium‐ and high‐coverage natural grassland area in the midstream region has decreased by 80·1%, and the downstream runoff has declined by 27·32% due to the continuous expansion of the cultivated land area. The contribution of cultivated land expansion to the impact on the annual total runoff is 14–31%, on the annual, spring and winter base flow it is 44–75%, and on spring and winter discharge it is 23–64%. Once the water conservation plan dominated by land‐use structural adjustments is implemented over the next 5 years, the mean annual discharge in the lower reach could increase by 8·98% and the spring discharge by 26·28%. This will significantly alleviate the imbalance between water supply and demand in both its quantity and temporal distribution in the middle and lower reaches. Copyright © 2006 John Wiley & Sons, Ltd.
A model of the wave and current boundary‐layer structure
Authors: Shi John Z. , Lu Li‐Feng
Published: October 2006

A model of the wave and current boundary‐layer structure was developed using the k–ε turbulent closure model. The finite‐difference method was used to solve the governing equations. Vertical logarithmic grids and equal time steps were adopted. The following modelled simulations were obtained: (1) vertical profiles of wave velocity amplitude, eddy viscosity coefficient and turbulent kinetic energy with waves only; (2) vertical profiles of wave velocity amplitude, mean current velocity, eddy viscosity coefficient and turbulent kinetic energy with waves having a following current. To test the validity and the rationality of the present model, vertical profiles of modelled wave velocity amplitude and mean velocity were compared with corresponding experimental results available in the literature. Copyright © 2006 John Wiley & Sons, Ltd.
Selenium labeled fatty acids as potential myocardial imaging agents
Authors: Sadek Samy A. , Basmadjian Garo P.
Published: October 2006

Six 75Se labeled fatty acid analogues were synthesized : 3‐selena‐[75Se]pentadecanoic acid, 4‐selena[75Se]hexadecanoic acid, 3‐selena[75Se]heptadecanoic acid, 4‐selena[75Se]octadecanoic acid, 3‐selena[75Se]nonadecanoic acid, and 4‐selena[75Se]‐eicosanoic acid. Selenious acid was reduced with NaBH4 in buffer pH 6.0. The nucleophile produced, NaSeH was reacted with different alkyl halide to form the corresponding selenol. To this was added an aqueous solution of the sodium salt of either iodoacetic acid or 3‐bromopropionic acid to form the sodium salt of the desired fatty acid. The free fatty acids were extracted in ether after acidification of the solution.
Photochemical enrichment of diacetyl [15‐3H] gibberellin‐A3‐7‐aldehydes by a tritium isotope effect
Authors: Lischewski M. , Liebisch H.‐W. , Adam G.
Published: October 2006

During photocyclisation of 15α‐ and 15α‐tritiated diacetylgibberellin‐A3‐7‐aldehydes to the cyclobutanols we found an enrichment of the tritium labelled starting aldehydes by an isotope effect. The mechanism of the sterically controlled abstraction of the 15α‐hydrogen/tritium‐atom is discussed.
Synthesis of 14C‐labelled benzetimide‐HCl
Authors: Van Wijngaarden I. , Soudijn W.
Published: October 2006

The synthesis of 14C‐benzetimide (dl‐1‐benzyl‐4‐(2, 6‐dioxo‐3‐phenyl‐3‐piperidyl)‐piperidine hydrochloride), using benzyl cyanide 14C (from K14CN and benzyl bromide) as starting material, is described. The five steps synthesis results in an overall yield of 38% of labeled benzetimide HCI (calculated on KCN used) with a specific activity of 0.5 mC/mM.

A seemingly preferent alternative route with the aid of 14C‐acrylonitrile could not be followed because of the instability of the labelled acrylonitrile (rapid polymerization).

The stability of benzetimide‐HCI at 37° C with varying pH is examined.
Compound Noise: Evaluation as a Robust Design Method
Authors: Singh Jagmeet , Frey Daniel D. , Soderborg Nathan , Jugulum Rajesh
Published: October 2006

This paper evaluates compound noise as a robust design method. Application of compound noise as a robust design method leads to a reduction in experimental effort. The compound noise strategy was applied to two types of situation: the first type has been described with active effects up to two‐factor interactions and the second type has been described with effects up to three‐factor interactions. These two situations are illustrated with help of case studies. The paper provides theoretical justification for the effectiveness of the compound noise strategy as formulated by Taguchi and Phadke. For example, we found that the compound noise strategy is very effective for systems which exhibit effect sparsity. This paper gives an alternative procedure to formulate a compound noise, distinctly different from Taguchi's formulation. The alternative method requires less information to formulate compound noise as compared to Taguchi's formulation. Overall, the paper studies the effectiveness of such an alternative formulation, outlines scenarios where compound noise as a robust design method can be effectively used and gives alternative strategies for the systems on which compound noise cannot be effective. Copyright © 2006 John Wiley & Sons, Ltd.
Nonlinear systems possessing linear symmetry
Authors: Cheng Daizhan , Yang Guowu , Xi Zairong
Published: October 2006

This paper tackles linear symmetries of control systems. Precisely, the symmetry of affine nonlinear systems under the action of a sub‐group of general linear groupGL(n,ℝ). First of all, the structure of state space (briefly, ss) symmetry group and its Lie algebra for a given system is investigated. Secondly, the structure of systems, which are ss‐symmetric under rotations, is revealed. Thirdly, a complete classification of ss‐symmetric planar systems is presented. It is shown that for planar systems there are only four classes of systems which are ss‐symmetric with respect to four linear groups. Fourthly, a set of algebraic equations are presented, whose solutions provide the Lie algebra of the largest connected ss‐symmetry group. Finally, some controllability properties of systems with ss‐symmetry group are studied. As an auxiliary tool for computation, the concept and some properties of semi‐tensor product of matrices are included. Copyright © 2006 John Wiley & Sons, Ltd.
The learning dialogue: Mentoring
Authors: Lester Virginia , Johnson Cynthia
Published: October 2006

Mentoring is perhaps the oldest form of developmental instruction—an experienced person teaching a less experienced person by precept and example.
The latent resources of the child's mind
Authors: Hess Robert D.
Published: October 2006

Dr. Hess was Asked to prepare this paper for presentation at several of the conferences in connection with the NASDTEC‐AAAS Study of Guidelines for Science and Mathematics in the Preparation Program of Elementary School Teachers in the winter and spring of 1961–62. His task was to stimulate thought by the conference participants on various issues related to the education of elementary school science and mathematics teachers. His thoughts may also stimulate science educators to consider research in the area of early experience in the learning of science.
A psychologist's counsel on curriculum design
Authors: Gagné Robert M.
Published: October 2006

This paper was read at the Conference on Science Instruction in Elementary and Junior High Schools sponsored by the AAAS Commission on Science Instruction at Cornell University in July, 1962. Dr. Gagné's assignment was to set forth some ideas on curriculum development which would stimulate thought and discussion by the conferees. It is hoped that his paper will do the same thing for JRST readers and that their reaction will appear in Comment and Criticism in subsequent issues.
American university policies and practice in preparing leaders in science education—a research report
Authors: Rutherford James
Published: October 2006

This article is based on a paper read by the author at the AETS meeting in Philadelphia in March, 1963. The research was done at Harvard University as part of his doctoral study. The comments by Watson and Smith also were delivered at the AETS meeting following Rutherford's presentation.
What should we teach in biology?
Authors: Novak Joseph
Published: October 2006

Dr. Novak, who is Associate Professor of Biological Education at Purdue University, prepared this article originally for News and Views of NABT, an official publication of the National Association of Biology Teachers, and it was published there in April, 1963. In view of its importance to science educators, the article is reprinted here with the permission of Dr. Novak and NABT.
The curriculum in science for an African school
Authors: Watson Fletcher G.
Published: October 2006

A number of American universities and other educational agencies are presently involved in the development of educational programs in the emerging nations of the world. Based‐on recent news reports from Washington, there will apparently be encouragement from the federal government for American educators and educational institutions to provide more of this kind of foreign aid. This article describes the science curriculum which Professor Fletcher Watson and his associates have prepared for the Comprehensive Secondary School in Western Nigeria. It was prepared as a working paper in November, 1962, in anticipation of the school's opening early in 1968. Professor Watson has agreed to provide additional reports for JRST readers on the evolution of the instructional program and the special problems encountered. These will be published in later issues of JRST.
Problem solving behavior of teachers as a function of conceptual structure
Authors: Sieber Joan E.
Published: October 2006

A report of a laboratory experiment and an interview study to examine problem solving behavior in relation to ideas about conceptual structure in teachers—based on a paper which the author read at the annual meeting of the American Educational Research Association in Chicago, February, 1964‐Research supported by the National Science Foundation.
The role of inquiry in science teaching
Authors: Rutherford F. James
Published: October 2006

Until science teachers are able to view scientific inquiry as part of the content of science—and until teachers become well grounded in the history and philosophy of science—they cannot be educated to teach science as inquiry. So says the author of this thoughtful article.
Reflections upon Bruner's hypothesis
Authors: Smith Gary R.
Published: October 2006

The educational philosophy of Jerome Bruner has stimulated considerable interest and discussion in recent years. The author of this article takes issue with Bruner's statement “that any subject can be taught effectively in some intellectually honest form to any child at any stage of development” and presents his objections through the use of formal logic.
A comparative study of selected needs, values, and motives of science and non‐science teachers
Authors: Bledsoe Joseph C. , Morris Kenneth T.
Published: October 2006

A report by Eugene Lee which appeared in an earlier issue of JRST described differences between science teachers and scientists. This study serves to enlarge our understanding of the science teacher by describing differences in personality traits between science teachers and non‐science teachers presently in service.
The Madison project's approach to a theory of instruction
Authors: Davis Robert B.
Published: October 2006

The reader is presented with a clinical approach to the development of a theory of instruction which seems consistent with modern views on learning. Examples of how the theory is put into practice are presented.
Cognitive development and the learning of elementary concepts
Authors: Wohlwill Joachim F.
Published: October 2006

Wohlwill calls for longitudinal studies and a sequential analysis to help solve the mystery of cognitive development. He holds that as a child develops, his perceptual set in approaching problems is supplanted by a different set which has to do more with symbolic operations relating to concepts. The development of this new set is discussed together with the role of measurement in the developmental process. Implications are drawn for providing general types of early experiences to facilitate cognitive development.
The transition from concrete to abstract cognitive functioning: Theoretical issues and implications for education
Authors: Ausubel David P.
Published: October 2006

Dr. Ausubel was requested to prepare an article to complement those which resulted from the Piaget Conference. In his article, he discusses the developmental stages and presents hypotheses concerning the trends which may account for the transition from concrete to abstract functioning.
Analyzing test responses with symbolic logic
Authors: Smith Gary R.
Published: October 2006

In view of the time required for classroom testing, it is important that maximum information be derived from the effort. This paper describes an attempt to use symbolic logic to do so.
A study of small group dynamics and productivity in the BSCS laboratory block program
Authors: Hurd Paul Dehart , Rowe Mary Budd
Published: October 2006

The amount of work accomplished in the laboratory is often dependent upon the efficiency of group work. Here is an attempt to determine factors which may inhibit productivity of small group efforts.
Cooperative development of locally oriented achievement tests in chemistry
Authors: Schmitt J. A. , Montean J. J. , Winter S. S. , Fare S. D.
Published: October 2006

The authors describe a cooperative effort to produce reliable tests with high content validity for the schools involved.
Training leaders in mathematics education a contrast with science education
Authors: Scandura Joseph M.
Published: October 2006

Some additional thoughts in JRST's continuing attention to the evolution of doctoral programs in education.
Precision in research on mathematics learning: The emerging field of psycho‐mathematics
Authors: Scandura Joseph M.
Published: October 2006

The field of learning psychology spans all the disciplines. This scholarly study, while primarily directing itself to the area of mathematics, will prove to be stimulating and thought provoking to all scientists.
Preparing secondary school teachers for 1980
Authors: Rutledge James A.
Published: October 2006

Evolution, not revolution, indicated for teacher education. Within functional limits diversity breeds innovation.
An analysis of the relationship between open‐ and closed‐mindedness and capacity for independent thought and action
Authors: Blankenship Jacob W. , Hoy Wayne K.
Published: October 2006

A study reporting on the personality correlates of dogmatism.
The personality profiles of influential science teachers, regular science teachers, and science research students
Authors: Handley Herbert M. , Bledsoe Joseph C.
Published: October 2006

Personality does make a difference.
Student outcomes with rotation of teachers in secondary biology
Authors: Engen Harold B. , Smith Daryl D. , Yager Robert E.
Published: October 2006

Look carefully at outcomes in the affective domain before exchanging a classroom with a rotating staff for the conventional one teacher design.
The relationship between the strategies of inquiry in science and Student Cognitive and Affective Behavioral Change
Authors: Raun Chester E. , Butts David P.
Published: October 2006

Researchable questions may have a theoretical base. Empirical evidence feeds back to re‐structure the theory. The case in point is children's problem solving behavior.
A statistical comparison between inductive and traditional laboratories in college physical science
Authors: Zingaro Joseph S. , Collette Alfred T.
Published: October 2006

An inductive approach to the physical science laboratory yields better performance on a test for critical thinking in the physical sciences than does the traditional approach.
Cross‐cultural investigation of the development of selected piagetian science concepts, social status, and reading readiness
Authors: Lepper Robert E.
Published: October 2006

The development of Piagetian conservation concepts reflects differences in cultural background rather than in race.
The development of the concept of acceleration in elemewtary school children
Authors: Raven Ronald J.
Published: October 2006

Ninety‐six children from the third grade through the sixth grade were given speed tasks and acceleration tasks. The results of the study suggest that the speed and acceleration tasks that require intensive logical operations could be used by the third and fourth grade children. The data also indicate that the speed and acceleration tasks that use extensive logical operations could be used by some fifth and sixth grade children.
Changing attitudes toward science: Undergraduates in 1967 and 1971
Authors: Schwirian Patricia M. , Thomson Barbara
Published: October 2006

The purpose of the study was to examine the change in attitudes toward science and the scientific institution which had occurred among undergraduate university students between 1967 and 1971. Two similar cohorts of university undergraduates were given Form A of the Schwirian Science Support Scale (Tri‐S) in 1967 and 1971. The populations were 398 students and 153 students, respectively. Data concerning relevant contingent independent variables were also collected.

The data were analyzed utilizing nine, two‐way analyses of variance. The major independent variable, time of administration, (1967 and 1971) was always one factor; the second factor in each ANOVA consisted of each of the nine contingent independent variables: (1) age; (2) sex; (3) religious preference; (4) father's education; (5) mother's education; (6) father's occupation; (7) academic major; (8) hometown size; and (9) type of high school.

The data from the nine, two‐way ANOVA's show significant differences ( p < .05 ) in only two instances. In the case of the association of the Tri‐S Scores with father's occupation at times one and two, it was observed that the higher the status of the father's occupation, the higher the student's Tri‐S score. This relationship was observed in both 1967 and 1971; there was no significant effect of time. Statistically significant differences in Tri‐S scores were also observed among students from different sized hometowns; and in this case, there was a change over time. In 1967 students from small and medium‐sized communities had significantly lower Tri‐S scores than students from farms and large cities. By 1971 the mean scores of the students from small and medium sized communities had increased, producing scores slightly higher than the farm and city students.

The findings indicate that the 1971 Midwestern university students in the sample are no less positive in their attitudes toward science than their 1967 counterparts. No significant differences between overall 1967 and 1971 scores exist and no significant differences over time were observed by age, sex, religious preference, father's or mother's education, father's occupation, academic major, or high school type.
The Israeli “Bagrut” examination in BSCS biology
Authors: Jungwirth E. , Dreyfus A.
Published: October 2006

This paper describes the rationale, construction, administration, and analysis of an externally set matriculation examination for BSCS students at the end of the 12th grade. The examination consisted of three equal parts: (1) functional information; (2) identification and application of principles; and (3) contributory mode understanding of the principles of biological enquiry.

The predetermined difficulty level proved to be only slightly overambitious, so that individual means had to be only slightly adjusted in order to meet the national norms.

Diagnosed deficiencies were concentrated mainly in the spheres of statistical treatment of experimental data, suggestions for technical arrangements of the experimental set‐up, and replications of the experiment.

Hope was expressed, that the continued use of an examination of this type, would help to eliminate the discrepancy between objectives emphasized by school teachers and those stressed by the BSCS examination (illustrated by the very low correlation between teachers' grades and results on this examination).
Conservation concepts in elementary chemistry
Authors: Hall John Ruthven
Published: October 2006

Conservation of chemical identity, composition, and mass are essential to the basic understanding of chemistry. In an investigation carried out with 11 to 12 year old children, using techniques analogous to those of Piaget, it is shown that, even after the completion of an introductory course in chemistry over a nine month period, conservation had not been attained in a considerable proportion of subjects. The frequencies of non‐conservation responses were in the order composition > identity > mass. It is concluded that re‐examination of introductory courses with a view to facilitating attainment of conservation may be called for.