bluuebunny/crossref_metadata_2025 huggingface dataset:
The International Market Entry Choices of Start-Up Companies in High-Technology Industries
Authors: Burgel Oliver , Murray Gordon C.
Published: December 2003

For a young, resource-constrained, technology-based start-up embarking on international sales, the choice of entry mode is a strategic decision of major importance. Yet within the emerging research stream of international entrepreneurship, curiously little attention has been devoted to the empirical analysis of foreign market entry forms. The authors address this important issue by analyzing the determinants of 398 export decisions taken from a U.K. survey of 246 technology-based start-ups with international activities. The findings show that the entry mode decision is necessarily a trade-off between the resources available and the support requirements of the customer. Issues of the innovativeness of the technology and the historic channel experience of the firm in its domestic market are particularly strong determinants of mode choice. The authors suggest that an organizational capability perspective on these firms’ behavior offers a better explanation of their entry decisions than either transaction cost or stage theory.
The Role of the Internationalization Process in the Performance of Newly Internationalizing Firms
Authors: Yip George S. , Biscarri Javier Gomez , Monti Joseph A.
Published: December 2003

A study of 68 recently internationalized U.S. firms, using structural equations, shows that newly internationalizing firms do not on average follow a highly systematic approach. Some firms make use of a systematic sequence of steps, and the more systematic the approach, the better is the performance.
Global Organizational Learning in the Supply Chain: A Low versus High Learning Study
Authors: Hult G. Tomas M. , Nichols Ernest L. , Giunipero Larry C. , Hurley Robert F.
Published: December 2003

The authors examine the effects of organizational learning on customer orientation and relationship commitment in the global supply chain. To examine the effects of exposure to organizational learning, the authors test the hypotheses in low- versus high-learning groups in two different samples. The user sample consists of 175 users, representing the international strategic business units of one U.S.-based multinational corporation (i.e., strategic business units located outside the home country of the United States). The buyer sample consists of the corporate buyers of 200 multinational corporations, and the focus is on their supply chain activities worldwide. The authors examine the activities and relationships between (1) users and buyers (as perceived by the users) and (2) buyers and suppliers (as perceived by the buyers) in the supply chain. Overall, the results suggest that facets of organizational learning have a positive influence on customer orientation and relationship commitment in the global supply chain. In addition, attending learning seminars to increase understanding and use of organizational learning concepts appears to have a positive effect on the supply chain relationships.
Modellierung der mittleren Phase der HIV-Infektion unter Medikation (Modelling the Middle Phase of HIV Infection during Medication)
Authors: Lichtenberg Gerwald , Nolde Kristian , Riedel Uta , Schwank Alexander , Stellbrink Hans-Jürgen
Published: December 2003

Der Beitrag stellt einen Ansatz zur Modellierung der mittleren Phase der HIV-Infektion unter Medikation vor. Das erstellte Modell beschreibt dabei die Konzentrationen von Viren, gesunden und infizierten CD4+-T-Zellen und CD8+-T-Zellen im Blut. Berücksichtigt werden neben den Sterbe-, Geburts- und Infektionsprozessen auch die Infektionshemmung durch Medikamente sowie Regelungsprozesse für die Zellkonzentrationen des Immunsystems. Der grundlegende Unterschied zwischen einer HIV-Infektion und anderen Viruserkrankungen kann dadurch als Unterschied in der internen Kopplungstruktur interpretiert werden. Die Parameter des Modells wurden anhand klinischer Messdaten geschätzt. Eine Möglichkeit zur Vorhersage der Medikamentenwirkung aufgrund der Messung der initialen Zellkonzentrationen vor Therapiebeginn wird vorgestellt.
Beziehungen zwischen qualitativen dynamischen Modellen und dem Frobenius-Perron-Operator (Connections between Qualitative Dynamical Models and the Frobenius-Perron Operator)
Authors: Lunze Jan , Schröder Jochen
Published: December 2003

The paper concerns the discrete-event behaviour of quantised systems. As the state can only be measured through a quantiser, trajectory bundles have to be considered, which can be represented for autonomous systems by the Frobenius-Perron operator and for systems with inputs by the Foias operator. These operators can be written down in an explicit form only for a restricted class of systems. Hence, discrete approximations of these operators are used in systems analysis. The paper shows that these approximations are identical to the state transition functions of stochastic automata, which are used in process diagnosis and verification. This interesting connection between results from mathematical systems theory and the literature on hybrid control systems makes it possible to combine the results obtained in both fields.
Internetbasierte Laborexperimente für die regelungstechnische Ausbildung (Internet-based Laboratory Experiments for Automatic Control Engineering Education)
Authors: Roth Hubert , Rösch Otto J. , Prusak Alexander
Published: December 2003

Die Fernsteuerung von Laborexperimenten in Verbindung mit didaktisch konzipierten Lerneinheiten ist Gegenstand dieses Artikels. Dabei wird die Entwicklung von multimedialen Plattformen erläutert, welche aus Lerneinheiten in Verbindung mit der Fernsteuerung realer Hardware bestehen. Die angebotenen Laborexperimente sind über das Internet fernsteuerbar und dienen der Ingenieursausbildung in der Regelungs- und Steuerungstechnik sowie der Mechatronik.
Eine Anwendung von Knowledge Discovery in Databases im eLearning (An Application of Knowledge Discovery in Databases in eLearning)
Authors: Köster Frank , Grawunder Marco
Published: December 2003

Dieser Artikel behandelt die Entwicklung eines Assistenzsystems für Nutzer elektronischer Lehr-/Lernmaterialien (eLLM). Dabei wird das simulatorbasierte Pilotentraining als konkrete Beispielanwendung betrachtet. In diesem Kontext wird insbesondere die mögliche Isolation von Nutzern eLLM als Problem hervorgehoben. Arbeiten zu Tutoriellen Systemen, Virtuellen Lerngemeinschaften, Lernarrangements o.Ä. diskutieren ein facettenreiches Instrumentarium zur Behandlung dieses Problems und prägen eben-so unseren Ansatz. Dieser zielt darauf ab, eine tutorielle Unterstützung sowie Aufgaben zur Bildung/Festigung virtueller Lerngemeinschaften an spezielle Softwarekomponenten (Agenten) zu delegieren, die den Nutzern uneingeschränkt als Assistenten zur Verfügung stehen. Bei der Implementierung der Verhaltensgrundlage dieser Agenten verfolgen wir einen datengetriebenen Zugang, wobei Methoden des Knowledge Discovery in Databases (KDD) zur Anwendung kommen. Die in diesem Zusammenhang erzielten Ergebnisse stellen den Schwerpunkt dieses Artikels dar. Sie umfassen Werkzeuge zum KDD sowie Resultate ihrer Anwendung.
Substrate Infiltration and Histological Fixatives Affect the In Situ Localisation of β‐Glucuronidase Activity in Transgenic Tissues
Authors: Preťová A. , Obert B. , Wetzstein H. Y.
Published: December 2003

The β‐glucuronidase (GUS) gene is a widely used reporter gene in transgenic research. This study shows that although histochemical localisation of GUS activity may be very specific, differences in incubation conditions and tissue status can lead to artificial localisations that are independent of gene activity. The objective of the current studies was to evaluate the factors that affect the in‐situ localisation of β‐glucuronidase using transgenic tobacco plants as model tissues. The aspects considered include tissue size as well as and the addition of surfactants, vacuum infiltration and chemical fixatives. Transgenic tobacco plants exhibited variable staining patterns dependent on the size of tissue assayed and the treatments that affected the infiltration of substrate. A gradient of blue staining was observed in larger tissue pieces (10 mm2), where staining in central areas was light blue in contrast to edges, which stained deep indigo. More intense staining was associated with peripheral cell layers and regions adjacent to leaf veins. Thinner tissue strips incubated under similar conditions exhibited intense and even X‐Gluc staining. Addition of Triton X‐100 (1%) surfactant and vacuum infiltration (2 min) produced considerably quicker and more uniform staining (intense and consistent indigo blue colour) of the examined tissue after a 4 to 6‐h incubation. Chemical fixation of tissues before GUS assay resulted in quantitative and histochemical differences in enzyme activity that were dependent on the fixative type and duration. Quantitative measurements using the MUG fluorometric assay showed that Histochoice™ provided the highest retention of GUS activity, maintaining more than 80 and 50% of the activity after fixation for 15 and 30 min, respectively. Activity in decreasing order was obtained with paraformaldehyde, glutaraldehyde, ethanol and FAA. GUS activity was affected not only by the type of fixative, but also by the duration of fixation with longer fixation producing lower GUS activity. From the experiments performed it can be concluded that those treatments that enhance substrate penetration, i.e., the addition of surfactant and vacuum infiltration, improve the consistency and speed of X‐Gluc staining.
Czochralskis schöpferischer Fehlgriff: ein Meilenstein auf dem Weg in die Gigabit‐Ära
Authors: Evers Jürgen , Klüfers Peter , Staudigl Rudolf , Stallhofer Peter
Published: December 2003

Der schnelle Wandel in Industrie, Wissenschaft und Gesellschaft beruht auf der rasanten Entwicklung der Mikroelektronik. Auch das tägliche Leben ist von dieser Entwicklung geprägt: Man denke nur an das Mobiltelefon oder die Chip‐Karte. Basismaterial für die Mikroelektronik sind Einkristalle aus Silicium mit hoher Reinheit und nahezu perfektem Kristallbau. Heute werden 95 % der Weltproduktion an einkristallinem Silicium nach dem Verfahren hergestellt, das der Pole Jan Czochralski 1916 entdeckte.

Die Siliciumeinkristalle, die heute produziert werden, sind etwa 2 m lang, haben einen Durchmesser von 300 mm und wiegen 265 kg. Durch Anlegen von Magnetfeldern während des Kristallziehens sind große Fortschritte erzielt worden. Forschung und Entwicklung haben gezeigt, dass neben der weiteren Vergrößerung des Einkristalldurchmessers auch dem Defekt‐Engineering, der Beherrschung der vielfältigen temperaturabhängigen Reaktionen von Kristallbaufehlern, entscheidende Bedeutung zukommt.
Synthesis and characterization of isotopically enriched methylmercury (CH3201Hg+)
Authors: Mizanur Rahman G. M. , Skip Kingston H. M. , Bhandari Sandeep
Published: December 2003

A simple procedure for the synthesis of an important standard, isotopically enriched methylmercury, which is not commercially available, has been established successfully. The isotopically enriched standard synthesized is utilized in conventional isotope dilution mass spectrometry (IDMS), as well as in speciated IDMS (SIDMS), for determination of the true concentration of methylmercury in environmental samples. The CH3201Hg+ standard has been synthesized from commercially available 201HgO and tetramethyltin. The synthesis time required is 1 h at 60°C. The product is highly pure, yielding more than 90% as 201Hg in CH3201Hg+. Hazardous dimethylmercury does not occur during this synthesis procedure. The product synthesized was analyzed using high‐performance liquid chromatography coupled with inductively coupled plasma mass spectrometry (ICP‐MS) and ICP‐MS alone in order to determine its concentration, isotopic composition and purity. The stability of the product was also evaluated for over 6 months and found to be stable at 4°C in the dark. The isotopically enriched methylmercury synthesized can be used in SIDMS and IDMS analyses as a standard. Copyright © 2003 John Wiley & Sons, Ltd.
Diorganotin(IV) complexes of D‐galacturonic acid: solid‐state and solution‐phase structural study
Authors: Bertazzi N. , Bruschetta G. , Casella G. , Pellerito L. , Rotondo E. , Scopelliti M.
Published: December 2003

Three diorganotin(IV) complexes of D‐galacturonic acid (H2GalA; R = Me, n‐Bu, Ph), two of which are new derivatives (R = Me, Ph), have been synthesized and their solid‐state and solution‐phase investigated by IR, Mössbauer, 1H, 13C and 119Sn NMR spectroscopy. The FTIR data suggest that H2GalA, in the dialkyltin derivatives, behaves as a dianionic ligand, coordinating the tin(IV) atom through an ester‐type carboxylate and deprotonated alcoholic hydroxo groups, whereas a bridging carboxylate occurs in the diphenyltin(IV) complex. Octahedral and trigonal bipyramidal local geometries on tin(IV) atoms are proposed for dialkyltin(IV)GalA and diphenyltin(IV)GalA complexes respectively on the basis of Mössbauer spectroscopy. In D2O solution, R2Sn(IV) moieties seem to be mainly coordinated by the GalA2− in the β‐furanosidic (β‐GalfA2−) form, involving the β‐furanosidic ring in rotational equilibrium. However, the α‐furanosidic (α‐GalfA2−), α‐pyranosidic (α‐GalpA2−) and the β‐pyranosidic (β‐GalpA2−) isomers are also involved in the coordination upon the tin atom to a minor extent. In DMSO‐d6 solution, R2Sn(IV) moieties are coordinated almost entirely by the GalA2− in the β‐furanosidic form. Copyright © 2003 John Wiley & Sons, Ltd.
Extremes of deterministic sub‐sampled moving averages with heavy‐tailed innovations
Authors: Scotto M. , Ferreira H.
Published: December 2003

Let {Xk}k⩾1 be a strictly stationary time series. For a strictly increasing sampling function g:ℕ→ℕ define Yk=Xg(k) as the deterministic sub‐sampled time series. In this paper, the extreme value theory of {Yk} is studied when Xk has representation as a moving average driven by heavy‐tailed innovations. Under mild conditions, convergence results for a sequence of point processes based on {Yk} are proved and extremal properties of the deterministic sub‐sampled time series are derived. In particular, we obtain the limiting distribution of the maximum and the corresponding extremal index. Copyright © 2003 John Wiley & Sons, Ltd.
Dual‐ and triple‐mode matrix approximation and regression modelling
Authors: Lipovetsky Stan , Michael Conklin W.
Published: December 2003

We propose a dual‐ and triple‐mode least squares for matrix approximation. This technique applied to the singular value decomposition produces the classical solution with a new interpretation. Applied to regression modelling, this approach corresponds to a regularized objective and yields a new solution with properties of a ridge regression. The results for regression are robust and suggest a convenient tool for the analysis and interpretation of the model coefficients. Numerical results are given for a marketing research data set. Copyright © 2003 John Wiley & Sons, Ltd.
The discounting of ambiguous information in economic decision making
Authors: van Dijk Eric , Zeelenberg Marcel
Published: December 2003

In three experimental studies we investigated how decision makers respond to ambiguous information about costs and benefits. In Experiment 1, we studied the effect of ambiguity about prior costs. Experiments 2 and 3 focused on the effect of ambiguity about future outcomes. The collective results of the three studies suggest that decision makers discount ambiguous information. The findings are related to insights on the disjunction effect, the sunk cost effect, transaction decoupling, and ambiguity aversion. Copyright © 2003 John Wiley & Sons, Ltd.
A simple and simultaneous determination of acyclovir and ganciclovir in human plasma by high‐performance liquid chromatography
Authors: Teshima Daisuke , Otsubo Kaori , Yoshida Tsuneko , Itoh Yoshinori , Oishi Ryozo
Published: December 2003

A simple high‐performance liquid chromatographic method was developed for the simultaneous determination of the therapeutic levels of acyclovir and ganciclovir in human plasma. After precipitation of plasma proteins with 6% perchloric acid, acyclovir and ganciclovir were simultaneously determined by reversed‐phase chromatography with spectophotometric detection at 254 nm. The peak heights for acyclovir and ganciclovir were linearly related to their concentrations ranging from 0.063 to 2.080 µg/mL. The recovery was 100.48–102.84% for acyclovir and 99.26–103.07% for ganciclovir. The intra‐ and inter‐day relative standard deviation values were in the range 0.186–8.703% for acyclovir and 0.137–6.424% for ganciclovir. The detection limits for both compounds were 0.01 µg/mL determined as the signal‐to‐noise ratio of 3. The present method is applicable to therapeutic monitoring during antiviral medication. Copyright © 2003 John Wiley & Sons, Ltd.
Determination of paeonol in rat plasma by high‐performance liquid chromatography and its application to pharmacokinetic studies following oral administration of Moutan cortex decoction
Authors: Wu Xinan , Chen Hongli , Chen Xingguo , Hu Zhide
Published: December 2003

Quantiﬁcation of paeonol, the principal bioactive component of Moutan cortex, in rat plasma following oral administration of Moutan cortex decoction was achieved by using a simple and sensitive high‐performance liquid chromatographic method. The calibration curves for paeonol were linear in both the low (25–200 ng/mL) and the high concentration range (200–4000 ng/mL) with r2 values of 0.9928 and 0.9993, respectively. The coefﬁcients of variation of intra‐ and inter‐day assays were 14.36, 6.52, 1.76, 1.25, 5.36, 3.30 and 1.42% and 12.70, 1.19, 2.98, 1.91, 1.75, 1.78 and 0.96% at concentrations of 25, 50, 100, 200, 500, 1000 and 2000 ng/mL, respectively. The recoveries of paeonol from rat plasma were found to be 101.9, 104.5, 105.4 and 101.2% for concentrations of 50, 500, 1000 and 2000 ng/mL, respectively. The paeonol plasma concentrations were ﬁtted to two‐compartment model with ﬁrst order absorption. The mean terminal half‐lives (t1/2) of paeonol was 80.9 min. Copyright © 2003 John Wiley & Sons, Ltd.
HPLC determination of ferulic acid in rat plasma after oral administration of Rhizoma Chuanxiong and its compound preparation
Authors: Li Yujuan , Bi Kaishun
Published: December 2003

An HPLC method is described for determination of ferulic acid in rat plasma. The concentration of ferulic acid in rat plasma was determined after deproteinization with acetonitrile using sulfamethoxazole as internal standard. Chromatographic separations were performed on a C18 stationary phase with a mobile phase composed of acetonitrile–water (16:84, v/v) with 1% glacial acetic acid. The UV detection wavelength was set at 320 nm. The method was successfully applied to the determination of pharmacokinetic parameters in rat plasma after oral administration of Rhizoma Chuanxiong and and its compound preparation Suanzaoren decoctions. The calibration curve was linear over the range 0.0510–4.08 µg/mL in rat plasma. Within‐day and between‐day precisions were less than 4.5% RSD. Mean recovery was determined as 96.9%. The limit of quantitation was 0.0510 µg/mL. The pharmacokinetic parameters of the two preparations were different signiﬁcantly (p < 0.05), which may attribute to the effects of other ingredients present in Suanzaoren decoction. Copyright © 2003 John Wiley & Sons, Ltd.
Biopartitioning micellar chromatography to predict skin permeability
Authors: Martínez‐Pla J. J. , Martín‐Biosca Y. , Sagrado S. , Villanueva‐Camañas R. M. , Medina‐Hernández M. J.
Published: December 2003

Dermal absorption of chemicals is an area of increasing interest to the pharmaceutical and cosmetic industries, as well as in dermal exposure and risk assessment processes. In this paper the capability of biopartitioning micellar chromatography (BMC) as an in vitro technique to describe compound percutaneous absorption is evaluated. A multivariate study (principal component analysis, partial least squares) is performed in order to evaluate the importance of some physicochemical variables on the skin permeability constant values. From these results, a quantitative retention–activity relationship model for predicting the skin permeability constants that uses the BMC retention data and melting point as descriptor variables was obtained from a heterogeneous set of 43 compounds. The main advantage of the proposed methodology is that it allows the obtention of permeability constants of ionic compound and it can be very useful to predict the effect of pH of vehicle on the skin permeability of xenobiotics. Copyright © 2003 John Wiley & Sons, Ltd.
Chemoenzymatic Synthesis of Branched Oligo‐ and Polysaccharides as Potential Substrates for Starch Active Enzymes
Authors: Greffe Lionel , Jensen Morten T. , Bosso Claude , Svensson Birte , Driguez Hugues
Published: December 2003

Oligo‐ and polysaccharides embodying the α‐maltotriosyl‐6II‐maltotetraosyl structure were readily synthesized by transglycosylation of maltosyl fluoride onto panose and pullulan catalysed by the bacterial transglycosylase cyclodextrin glycosyltransferase (CGTase). The two products obtained proved useful for increasing the knowledge of substrate binding and processing at the active site of barley limit dextrinase that is involved in the metabolism of amylopectin by acting upon its branch points.
Characterization of Slurries Used for Chemical‐Mechanical Polishing (CMP) in the Semiconductor Industry
Authors: Kuntzsch T. , Witnik U. , Hollatz M. , Stintz M. , Ripperger S.
Published: December 2003

In the chemical‐mechanical polishing applied during the manufacture of semiconductor devices the polishing slurry is of major importance for the processing result and hence, a permanent, strict monitoring of the slurry properties is necessary. For this purpose qualified particle size analysis methods for the characterization of the solid particles used in the CMP slurries are required. Additionally, small amounts of agglomerates and large particles have to be detected.
Engineering Solutions for Limiting the Increase of Atmospheric Carbon Dioxide
Authors: Arlt W.
Published: December 2003

The article describes possible engineering solutions that can reduce the carbon dioxide (CO2) content of the air. To demonstrate the point fossil fuel power plants will be taken as a model for the source of CO2. The global mass balance shows that the oceans play a major role in storing CO2. The hypothesis presented states that the real problem is not the absolute CO2 content, rather its change. Consequently, present emissions should be stored for future release. Under the current worldwide measures to reduce power consumption CO2 emissions are unlikely to decrease. A number of strategies for the maritime sequestration of CO2 are reported in the contribution. One proposal for sequestration is the use of shallow waters which form a thermohaline current: the dissolved gas will travel for hundreds of years in deep sea currents. In the latter case, CO2 injection is easily achieved. Several scenarios are considered for the fate of this CO2‐enriched current. The environmental impact is briefly reported. The article will describe current research requirements, demonstrating that similar research in the US and Japan is presently more advanced in comparison to that in Europe.

The sequestration of carbon dioxide on land will be the subject of a second publication. It is obvious that the sequestration of CO2 is the method after all rational chances to save energy.
Actin‐binding proteins required for reliable chromosome segregation in mitosis
Authors: Gerisch Günther , Faix Jan , Köhler Jana , Müller‐Taubenberger Annette
Published: December 2003

While studying mitosis in Dictyostelium mutants with deficiencies in actin‐binding proteins, we found that two of these proteins, cortexillin and Aip1, are required for the precise segregation of chromosomes. Atypical spindles and nuclei with varying DNA content indicate that mutants lacking cortexillin or Aip1 are genetically unstable. These aberrations are caused by the detachment and irregular reattachment of centrosomes to the nuclear surface. Live imaging showed how coalescing mitotic complexes give rise to a multipolar spindle, and how excess centrosomes can be eliminated by mitotic cleavage between anucleate and nucleated portions of a cell. We hypothesize that mutations in regulatory proteins of the actin network might be one cause of genetic instability of malignant tumor cells. Cell Motil. Cytoskeleton 57:18–25, 2004. © 2003 Wiley‐Liss, Inc.
Characterization of an amacrine cell type of the mammalian retina immunoreactive for vesicular glutamate transporter 3
Authors: Haverkamp Silke , Wässle Heinz
Published: December 2003

Immunocytochemical staining of vertical sections through rat, mouse, and macaque monkey retinae with antibodies against the vesicular glutamate transporter vesicular glutamate transporter 3 (vGluT3) showed a sparse population of amacrine cells. The labeled cells had similar appearances in the three species and probably represent homologous types. They were studied in detail in the rat retina. The thin varicose dendrites of vGluT3 amacrine cells formed a convoluted dendritic tree of approximately 100 μm in diameter that was bistratified in the center of the inner plexiform layer. The dendrites of vGluT3 cells were squeezed between the two strata of cholinergic dendrites. The density of vGluT3 cells was measured in retinal wholemounts and increased from 200/mm2 in peripheral retina to 400/mm2 in central retina, accounting for about 1% of all amacrine cells in the rat retina. The vGluT3 cells had a two‐ to threefold dendritic overlap, and their cell bodies formed a regular mosaic, suggesting they represent a single type of amacrine cell. The vGluT3 amacrine cells expressed glycine and glycine transporter 1 (GlyT1) but not the vesicular glycine transporter (vesicular inhibitory amino acid transporter). They also expressed glutamate; hence, there is the possibility that, comparable to cholinergic amacrine cells, they are “dual transmitter” amacrine cells. The synaptic input of vGluT3 cells was studied by electron microscopy. They received input from bipolar cells at ribbon synapses and from other amacrine cells at conventional synapses. The types of bipolar cells possibly involved with vGluT3 cells were demonstrated by double labeling sections for vGluT3 and the calcium‐binding protein CaB5. The axon terminals of type 3 and 5 bipolar cells costratified with vGluT3 dendrites, and it is possible that vGluT3 cells have ON and OFF light responses. J. Comp. Neurol. 468:251–263, 2004. © 2003 Wiley‐Liss, Inc.
Multiple spot diffusing geometries for indoor optical wireless communication systems
Authors: Al‐Ghamdi A. G. , Elmirghani J. M. H.
Published: December 2003

In order to improve the performance of indoor optical wireless communication links, two multispot diffusing geometries based on diamond and line strip spot distribution geometries are proposed, analysed and compared to the known uniform spot distribution. Such geometries combine the advantages of the diffuse and the line‐of‐sight systems, giving great robustness and ease of use. The novel line strip multibeam transmitter geometry has resulted in a receiver signal‐to‐noise ratio (SNR) improvement of about 4 dB compared to the conventional diffuse system as well as a significant reduction in the pulse spread. Simulation and comparison results for both the conventional diffuse system and the three multispot diffusing geometries are presented. Further, pulse responses, SNR, and delay spread results at various locations are presented. Copyright © 2003 John Wiley & Sons, Ltd.
Intranuclear inclusions in a case of pigmented villonodular synovitis of the ankle
Authors: Gangane Nitin , Anshu  , Shivkumar V.B. , Sharma S.M.
Published: December 2003

Pigmented villonodular synovitis (PVNS) is a proliferative disorder of the synovial lining of the joints. Although the cytological findings of this disorder have been described in the literature, there is no mention of intranuclear cytoplasmic inclusions in this entity. A 65‐yr‐old woman presented with a painful swelling on the ankle. In addition to other characteristic findings of PVNS, we found the presence of intranuclear cytoplasmic inclusions in the fine‐needle aspiration (FNA) smears. The characteristic cytological findings of abundant mononuclear cells occurring singly and in papillary clusters, multinucleated giant cells, and hemosiderin deposition should aid in the diagnosis of PVNS and in its differentiation from melanoma and other soft tissue sarcomas, even in the presence of uncommon features such as intranuclear inclusions. Diagn. Cytopathol. 2003;29:349–351. © 2003 Wiley‐Liss, Inc.
Early recognition of newborn goat kids by their mother: II. Auditory recognition and evidence of an individual acoustic signature in the neonate
Authors: Terrazas Angelica , Serafin Norma , Hernández Horacio , Nowak Raymond , Poindron Pascal
Published: December 2003

The vocal recognition of newborn kids by their mother at 2 days postpartum and the possible existence of interindividual differences in the voice structure of newborn kids were investigated in two separate studies. The ability of goats to discriminate between the bleats of their own versus an alien kid was tested at 2 days postpartum in mothers being prevented access to visual and olfactory cues from the young. Goats spent significantly more time on the side of the enclosure from which their own kid was bleating, looked in its direction for longer, and responded more frequently to the bleats of their own than to those of the alien kid (p < 0.05). In the second study, the sonograms of 13 kids, studied from Days 1 to 5, showed significant interindividual differences for the five variables taken into account and on each of the 5 days (duration of bleat, fundamental frequency, peak frequency, and numbers of segments and of harmonics). The potential for individual coding ranged between 1.1 and 4.1, indicating that for some variables variations between individuals were greater than intraindividual variations. Furthermore, when considering the five parameters together, the discriminating scores showed an average of 95% in the 78 combinations of any 2 kids for any given day. Finally, some significant intraindividual differences also were found between days, suggesting ontogenic changes in the characteristics of the kid's voice in early life. Therefore, mother goats are likely to recognize the vocalizations of their 48‐hr‐old kids, as they show sufficient interindividual variability to allow the existence of individual vocal signatures, even though some of the characteristics of the bleats change rapidly over time. © 2003 Wiley Periodicals, Inc. Dev Psychobiol 43: 311–320, 2003.
Long‐term effects of prenatal morphine exposure on maternal behaviors differ from the effects of direct chronic morphine treatment
Authors: S̆lamberová Romana , Bar Noffar , Vathy Ilona
Published: December 2003

Previous studies have demonstrated that chronic morphine treatment of pregnant rats alters maternal behavior. Other studies have shown long‐term effects of prenatal exposure to morphine, including changes in reproductive behavior in adult females. The present study investigated the effects of prenatal morphine exposure on a variety of maternal behaviors such as nursing, maternal activities, nonmaternal activities, and pup retrieval. Prenatal morphine exposure increased active and decreased passive nursing. There were no differences in maternal activities such as presence in the nest, contact with pups, grooming of pups, and/or manipulation of nest shavings. In the retrieval test, prenatally morphine‐exposed mothers were faster in carrying the first pup, retrieving the first pup back to the nest, and returning all pups to the nest than prenatally saline‐exposed mothers. Maternal and nonmaternal activities also were affected by the light:dark cycle. All saline‐ and morphine‐exposed mothers nursed more, were more often in the nest, and more often in contact with greater than half of their litter during the light than the dark sessions. On the other hand, nonmaternal activities increased during the dark sessions: Mothers cared for themselves (groomed, ate) more and displayed more rearing and sniffing. Mothers spent more time resting with their eyes closed during the light sessions regardless of prenatal drug exposure. The present study demonstrated that the effect of morphine on maternal behavior is different in adult exposed and prenatally exposed mothers. While direct morphine treatment impaired maternal behaviors, prenatal morphine exposure has the opposite effect. © 2003 Wiley Periodicals, Inc. Dev Psychobiol 43: 281–289, 2003.
Reduced cumulative incidence of diabetes but not insulitis following administration of chimeric human IL‐15–murine IgG2b in NOD mice
Authors: Signore A. , Annovazzi A. , Giacalone P. , Beales P. E. , Valorani M. G. , Vestri A. R. , Ruberti G. , Manfrini S. , Pozzilli P. , Bulfone‐Paus S.
Published: December 2003

Background

It has been recently demonstrated that apoptosis is involved in beta‐cell destruction in the NOD mouse model of diabetes. The aim of the present study was to investigate whether IL‐15, a cytokine involved in the modulation of the apoptotic process, is capable of modifying the natural history of diabetes and/or insulitis in pre‐diabetic NOD mice. The rationale for the use of IL‐15‐IgG2b recombinant cytokine is related to its long half‐life (28 ± 4 h).

Methods

At 10 weeks of age, 2 groups of 24 female mice were treated with single or multiple i.p. doses of IL‐15‐IgG2b respectively. As control, 2 groups of 24 age‐ and litter‐matched female mice were injected intra‐peritoneally with single or multiple doses of IgG2b immunoglobulin.

Results

Diabetes incidence at 33 weeks of age was lower in the group of mice treated with multiple doses than in the control group (p = 0.03). The cumulative incidence of diabetes at 33 weeks of age between single‐dose treated mice and the control group was similar. No significant differences in the calculated index of insulitis were observed in all treated and control mice.

Conclusions

We conclude that IL‐15‐IgG2b reduces the cumulative incidence of diabetes, without affecting the extent and severity of the insulitis process. Considering this and the well‐defined anti‐apoptotic effects of IL‐15, we suggest that the reduction of diabetes incidence could be due to a down‐regulation of beta‐cell apoptosis. Copyright © 2003 John Wiley & Sons, Ltd.
Vascular endothelial growth factor and diabetic retinopathy: pathophysiological mechanisms and treatment perspectives
Authors: Caldwell Ruth B. , Bartoli Manuela , Behzadian M. Ali , El‐Remessy Azza E. B. , Al‐Shabrawey Mohamed , Platt Daniel H. , Caldwell R. William
Published: December 2003

Retinal neovascularization and macular edema are central features of diabetic retinopathy, the major cause of blindness in the developed world. Current treatments are limited in their efficacy and are associated with significant adverse effects. Characterization of the molecular and cellular processes involved in vascular growth and permeability has led to the recognition that the angiogenic growth factor and vascular permeability factor vascular endothelial growth factor (VEGF) plays a pivotal role in the retinal microvascular complications of diabetes. Therefore, VEGF represents an exciting target for therapeutic intervention in diabetic retinopathy. This review highlights the current understanding of the mechanisms that regulate VEGF gene expression and mediate its biological effects and how these processes may become altered during diabetes. The cellular and molecular alterations that characterize experimental models of diabetes are considered in relation to the influence of high glucose‐mediated oxidative stress on VEGF expression and on the mechanisms of VEGF's actions under hyperglycemic induction. Finally, potential therapeutic strategies for preventing VEGF overexpression or blocking its pathological effects in the diabetic retina are considered. Copyright © 2003 John Wiley & Sons, Ltd.
Alternative promoters and polyadenylation regulate tissue‐specific expression of Hemogen isoforms during hematopoiesis and spermatogenesis
Authors: Yang Li V. , Heng Henry H. , Wan Junmei , Southwood Cherie M. , Gow Alexander , Li Li
Published: December 2003

Hemogen is a nuclear protein encoded by HEMGN (also known as hemogen in mouse, EDAG in human and RP59 in rat). It is considered to be a hematopoiesis‐specific gene that is expressed during the ontogeny of hematopoiesis. Herein, we characterize two distinct splicing variants of HEMGN mRNA with restricted expression to hematopoietic cells and to round spermatids in the testis, respectively. Expression of the testis‐specific HEMGN mRNA (HEMGN‐t) is developmentally regulated and is concurrent with the first wave of meiosis in prepuberal mice. Sequence analysis reveals that HEMGN‐t and the hematopoietic HEMGN mRNA (HEMGN‐h) share a common coding sequence with distinct 5′ and 3′ untranslated regions and that these two isoforms are transcribed from the same gene locus, HEMGN, through the use of alternative promoters and polyadenylation sites. Thus, HEMGN expression exemplifies a developmental regulatory mechanism by which the diversification of gene expression is achieved through using distinct regulatory sequences in different cell types. Moreover, the existence of a testis‐specific isoform of HEMGN suggests a role in spermatogenesis. Finally, fluorescence in situ hybridization demonstrates that HEMGN is localized to chromosome 4 A5‐B2 in mouse and to chromosome 9q22 in human, which is a region known to harbor a cluster of leukemia breakpoints. Developmental Dynamics 228:606–616, 2003. © 2003 Wiley‐Liss, Inc.
DNA sequence motifs conserved in endocrine promoters are essential for Pax4 expression
Authors: Brink Christopher , Gruss Peter
Published: December 2003

The paired box transcription factor Pax4 is required for maturation of insulin‐producing β‐ and somatostatin secreting δ‐cells in the murine pancreas. It starts to be expressed in pancreatic precursors and later is restricted to β‐ and δ‐cells to finally be switched off after birth. A 0.9‐kb genomic DNA fragment has been shown to mediate the Pax4 expression pattern. Transcription factors Pdx1 and NeuroD bind to this fragment at A2‐ and E1‐sequence motifs. In this study, we downscale the size of this fragment to 409 bp. Another genomic fragment of 254 bp is still able to mediate the specificity, but not the strength of Pax4 expression. Deletion of the A2 and E1 elements results in loss or weakening of reporter gene expression. Because A2 and E1 elements are conserved in numerous pancreatic promoters, they might play a general role in regulating endocrine gene expression. Developmental Dynamics 228:617–622, 2003. © 2003 Wiley‐Liss, Inc.
Expression of connexin48.5, connexin44.1, and connexin43 during zebrafish (Danio rerio) lens development
Authors: Cheng Shaohong , Christie Tara , Valdimarsson Gunnar
Published: December 2003

Connexins (Cx), the protein units of gap junctions, play important roles in lens development and homeostasis. Here, we report the mRNA expression patterns of zebrafish Cx48.5, Cx44.1, Cx43 during lens development. The expression of all three connexins in the adult lens was first confirmed by reverse transcriptase‐polymerase chain reaction. By whole‐mount in situ hybridization, we detected Cx48.5 expression throughout the lens, except the lateral lens epithelium, at 36 hours postfertilization (hpf). The pattern remained the same at 2 days postfertilization (dpf). By 3 and 4 dpf, Cx48.5 expression was restricted to the differentiating lens fibers in the equatorial and medial regions. Cx44.1 was expressed in a similar manner as Cx48.5 from 36 hpf to 4 dpf. However, Cx44.1 expression was also detected in the lens at 24 hpf. Cx43 expression was detected throughout the lens at 24 and 36 hpf but became restricted to the lateral epithelium at later stages. Developmental Dynamics 228:709–715, 2003. © 2003 Wiley‐Liss, Inc.
Asymmetry in Bridged Binuclear Metalloenzymes: Lessons for the Chemist
Authors: Belle Catherine , Pierre Jean‐Louis
Published: December 2003

This microreview describes the structures, properties and mechanisms of three selected bimetallic enzymes: Cu‐Zn superoxide dismutase (SOD), purple acid phosphatases (PAPs) and catechol oxidases (COs). The relevance of the unsymmetrical structures in the binucleating environment to the reaction mechanism and the respective roles of each metal center of these enzymes are discussed. Relevant model compounds are also considered. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
Novel Hybrid Porous 3D Networks of Lead(II) Diphosphonate and Triphosphonate Containing 1,3,5‐Benzenetricarboxylate
Authors: Song Jun‐Ling , Mao Jiang‐Gao , Sun Yan‐Qiong , Clearfield Abraham
Published: December 2003

Hydrothermal reactions of lead(II) acetate with 1,3,5‐benzenetricarboxylic acid (H3BTC) and a new aminodiphosphonic acid, [3‐pyridyl‐CH2N(CH2PO3H2)2] (H4L1), or a new aminotriphosphonic acid, [1‐{(H2O3PCH2)2NCH2CH2‐}‐piperazine‐4‐CH2PO3H2] (H6L2), afforded two novel porous carboxylate−phosphonate hybrids, [Pb4(BTC)(HBTC)(HL1)]·3H2O (1) and [Pb6(BTC)2(HBTC)(H2L2)]·4.5H2O (2). The structure of 1 is built from a 3D porous network of lead(II) tricarboxylate and 1D double chains of lead(II) aminodiphosphonate. The structure of 2 contains <002> lead(II) carboxylate−phosphonate hybrid layers, which are cross‐linked by 1D double chains of lead(II) phosphonate through the organic groups of both types of ligands, resulting in the formation of a complex 3D porous network. The lattice water molecules in both compounds are located at the micropores of the structures. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
Preparation of Optically Active α‐Amino[3]ferrocenophanes − Building Blocks for Chelate Ligands in Asymmetric Catalysis
Authors: Liptau Patrick , Tebben Ludger , Kehr Gerald , Wibbeling Birgit , Fröhlich Roland , Erker Gerhard
Published: December 2003

Treatment of 1,1′‐diacetylferrocene (4) with dimethylamine and TiCl4 yielded the unsaturated dimethylamino‐substituted [3]ferrocenophane product 5. Its catalytic hydrogenation gave the corresponding saturated [3]ferrocenophane system 6 (trans/cis ≈︁ 7:1). The rac‐[3]ferrocenophane amine 6 was partially resolved (to ca. 80% ee) by means of L‐ or D‐O,O′‐dibenzoyltartrate salt formation. Treatment of 4 with the pure (R)‐ or (S)‐methyl(1‐phenylethyl)amine (8)/TiCl4 gave the corresponding optically active unsaturated [3]ferrocenophane amines (R)‐(+)‐9 and (S)‐(−)‐9, respectively. Their catalytic hydrogenation again proceeded trans‐selectively, giving the corresponding saturated diastereomeric [3]ferrocenophane amines (1R,3R,5R)‐10a and (1S,3S,5R)‐10b [starting from (R)‐9], their enantiomers ent‐10a and ent‐10b were obtained from (S)‐9, but with a poor asymmetric induction (10a/10b < 2:1). Quaternization of 6 (CH3I) followed by amine exchange using (R)‐ or (S)‐methyl(1‐phenylethyl)amine (8), respectively, proceeded with overall retention. Subsequent chromatographic separation gave the pure diastereoisomers (1R,3R,5R)‐10a and (1S,3S,5R)‐10b [from (R)‐8, ent‐10a and ent‐10b from (S)‐8] in > 60% yield. Subsequently, the benzylic (1‐phenylethyl) auxiliary was removed from the nitrogen atom by catalytic hydrogenolysis to yield the enantiomerically pure (> 98%) ([3]ferrocenophanyl)methylamines (1R,3R)‐11 and (1S,3S)‐11, respectively, which were converted into the corresponding dimethylamino‐substituted [3]ferrocenophanes (1R,3R)‐6 and (1S,3S)‐6. Each enantiomer from the following enantiomeric pairs was isolated in its pure form and characterized by X‐ray diffraction: (R)‐9/(S)‐9; (1R,3R,5R)‐10a/(1S,3S,5S)‐10a; (1R,3R,5S)‐10b/(1S,3S,5R)‐10b; (1R,3R)‐11/(1S,3S)‐11. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
Recent advances in the determination of enantiomeric drugs and their metabolites in biological fluids by capillary electrophoresis‐mediated microanalysis
Authors: Sueli Bonato Pierina
Published: December 2003

This review summarizes the recent developments in the application of electromigration techniques for the enantioselective analysis of drugs and metabolites in biological fluids. During the period covered by this review, it has been observed an increase in the use of negatively charged chiral selectors, particularly sulfobutyl ether‐β‐cyclodextrin and sulfated‐β‐cyclodextrin, and the combination of two different chiral selectors in the running buffer to obtain the resolution of drugs and their metabolites. Low detection limits as required for pharmacokinetic studies were obtained by using concentration techniques, including sample stacking procedures, and more sensitive detection systems, such as laser‐induced fluorescence and mass spectrometry. Finally, the major points are discussed that can be considered to obtain reliable methods for enantioselective bioanalysis.
Recent advances in the application of capillary electrophoresis for food analysis
Authors: Frazier Richard A. , Papadopoulou Athina
Published: December 2003

This article reviews recent developments in the application of capillary electrophoresis (CE) for the analysis of foods and food components. CE has been applied to a number of important areas of food analysis and is fast becoming an established technique within food analytical and research laboratories. Papers are reviewed that were published during the two years to date following the previous review (Electrophoresis 2001, 22, 4197–4206).
Capillary electrophoresis of proteins 2001–2003
Authors: Hutterer Katariina , Dolník Vladislav
Published: December 2003

This review article with 244 references describes recent developments in capillary electrophoresis of proteins and covers the two years since the previous review (Dolník, V. Hutterer, K. Electrophoresis 2001, 22, 4163–4178) through Spring 2003. It covers topics related to CE of proteins including modeling of the electrophoretic properties of proteins, sample pretreatment, wall coatings, improving selectivity, detection, special electrophoretic techniques, and applications.
Recent applications in capillary electrochromatography
Authors: Eeltink Sebastiaan , Rozing Gerard P. , Kok Wim Th.
Published: December 2003

The most recent and important applications in capillary electrochromatography (CEC) are summarized, covering literature published since May 2001. A selection of new developments in stationary phases for CEC is highlighted, and enantiomeric separations and chiral stationary phases are discussed. Also, CEC applications of biological molecules, pharmaceuticals, and applications in the field of industrial and environmental analysis are summarized. For this review three modes of CEC were taken into account, i.e., packed‐column CEC, CEC using monolith technology, and open‐tubular CEC.
Analysis of antibiotics by capillary electrophoresis
Authors: Flurer Cheryl L.
Published: December 2003

Recent developments in the characterization of antibiotics are reviewed. Many capillary electrophoretic techniques have been utilized in their analyses, addressing various aspects of quantifying, profiling, and monitoring. Laser‐induced fluorescence detection systems demonstrated their usefulness in clinical settings and in the monitoring of residue levels in food matrices. Different sample introduction methods have been explored, enhancing detection sensitivity, or reducing or eliminating sample manipulation prior to injection.