bluuebunny/crossref_metadata_2025 huggingface dataset:
Quasi‐Lumped Element Quadrature Coupler Design
Authors: O'Calreallain S. B. D. , Fusco V. F.
Published: July 2010

In this paper synthesis equations for a type of directional coupler that employs both distributed and lumped elements with phase quadrature characteristics are developed This configuration will be referred to as the quasi‐lumped coupler. Theoretical and practical results are presented for an inductive coupler operating at 100 MHz and a capacitive coupler operated at 500 MHz. The major application for the class of couplers described in this paper is for millimetric MMICs.
On The Design and Development of a Ring‐Type Microstrip Power Divider with any Desired Power Division Ratio
Authors: Roy Jibendu Sekhar , Poddar Dipak Ranjan , Mukherjee Amitava , Chowdhury Santorh Kumar
Published: July 2010

For the computation of the characteristic impedance of curved microstrip transmission lines, a semiempirical expression is derived. This expression is applied to the design of a ring‐type power divider and the performance of the device is compared to another power divider designed using Wheeler's expression. Significant improvement in device performance is achieved.
Gonadal dysfunction due to cis‐platinum
Authors: Wallace W. H. B. , Shalet S. M. , Crowne E. C. , Morris‐Jones P. H. , Gattamaneni H. R. , Price D. A.
Published: July 2010

Gonadal function was studied in 15 patients, 12 pubertal or postpubertal, and three prepubertal, who had been treated during childhood for nonmetastatic osteosarcoma of the long bones by chemotherapy regimens that included cis‐platinum and adriamycin. Of seven postpubertal female patients assessed (mean age at diagnosis 16.5 years), three were amenorrhoeic and showed evidence of ovarian damage with raised gonadotrophin levels and a low serum oestradiol concentration. One patient who had regular periods had a raised lutealphase follicle‐stimulating hormone (FSH) concentration suggestive of gonadal dysfunction. Severe oligospermia or reduced testicular volumes in the presence of raised gonadotrophin levels were observed in three of the five pubertal males (mean age at diagnosis 13.25 years). A reliable assessment of gonadal function was not possible in three male patients who remained prepubertal at the time of study. The median total dose of cis‐platinum received by those patients with gonadal damage (median dose, 490 mg) was significantly higher than in those patients with normal gonadal function (median dose, 300 mg) (P = 0.01). In the boys the damage to the testes was primarily directed at the germinal epithelium. Leydig cell function was intact and the males progressed spontaneously through puberty. In the girls, unlike the boys, there was evidence of reversibility of gonadal damage with time. This is the first study to show gonadal dysfunction due to cis‐platinum and adriamycin therapy in childhood.
Mixture analysis by NMR as applied to fruit juice quality control
Authors: Spraul Manfred , Schütz Birk , Humpfer Eberhard , Mörtter Monika , Schäfer Hartmut , Koswig Susanne , Rinke Peter
Published: July 2010

Nuclear magnetic resonance (NMR) spectroscopy is rapidly gaining importance in mixture analysis, originally driven by the pharmaceutical and nowadays also by clinical applications within metabonomics. Quality control of food‐related material has very similar requirements, as it also deals with mixtures, and many of the compounds found in body fluids are analyzed as well. NMR allows analysis in two ways within one experiment: namely, targeted and untargeted. Targeted stands for the safe identification and consequent quantification of individual compounds, whereas untargeted means the detection of all deviations visible by NMR using statistical analysis based on normality models. Very important is the stability and reproducibility of the NMR instrumentation used, and this means inherent minimized system internal variance. NMR is especially suited for such requirements, as it allows detection of the smallest concentration changes of many metabolites simultaneously. High‐throughput flow‐injection NMR as the basis for fruit juice screening allows low cost per sample and delivers substantially more relevant information than any other method and is probably the only method to produce such results. Copyright © 2009 John Wiley & Sons, Ltd.
Inflammation‐induced leukocyte accumulation in injured skeletal muscle: Role of mast cells
Authors: Côt́e Claude H. , Tremblay Marie‐Héléne , Duchesne Elise , Lapoite Benoit M.
Published: July 2010

Inflammation consequent to muscle damage is characterized by an accumulation of leukocytes. Our aim in this study was to determine whether mast cells can modulate inflammation‐induced leukocyte trafficking. One approach consisted of giving rats a mast cell–degranulating agent, CMP 48/80, prior to a protocol of lengthening contractions inducing inflammation without neutrophil accumulation; in parallel, other rats were given the mast cell–stabilizing agent, cromolyn, prior to injecting muscle with bupivacaine, which induces neutrophil accumulation. Damage was evaluated through measurement of contractile force and inflammation using histochemical and immunohistochemichal methods. Stimulation with CMP 48/80 increased the proportion of degranulated mast cells significantly and neutrophil accumulation occurred with lengthening contractions. With bupivacaine, accumulation of neutrophils decreased by 70% when degranulation was inhibited. These results indicate that mast cells are important in the process governing leukocyte trafficking in skeletal muscle trauma and that targeting their inhibition could be an attractive alternative for control of inflammation. Muscle Nerve, 2008
“Bullvalen war am amüsantesten”
Authors: Zbikowski Frauke , Hopf Henning
Published: July 2010

William von Eggers Doering war ein Pionier der theoretischen und mechanistischen organischen Chemie. Er beschäftigte sich intensiv mit Reaktionsmechanismen, synthetisierte unter anderem Chinin sowie Tropolon, Tropon und das Tropylium‐Kation, deren Aromatiziät er nachwies, arbeitete über Carbene, thermische Umlagerungen und sagte die Existenz des Bullvalens voraus. Henning Hopf sprach mit dem 91‐jährigen über Neugier, Politik und die Zusammenarbeit mit Robert Burns Woodward.
Kapillarelektrophorese – Zukunft durch Chip‐Technik
Authors: Leinweber Felix Christian
Published: July 2010

Neuere Entwicklungen in der Lab‐on‐a‐Chip‐Technik und in der Elektrokinetik machen die Kapillarelektrophorese empfindlicher und flexibler. Dies könnte ihr Anwendungsspektrum erweitern und die Methode zu einer Alternative für chromatographische Verfahren im Spurenbereich machen.
Von der Chemiatrie zur modernen Chemie
Authors: Mönnich Michael
Published: July 2010

Durch die Verbindung von Alchemie und Medizin begründete Theophrastus Bombastus von Hohenheim, der sich selbst Paracelsus nannte, die Chemiatrie. Über diese Wissenschaft fand die Beschäftigung mit Chemie dann Eingang in die Medizin und in die Universitäten.
Investoren wenig beeinträchtigt
Authors: Schneider Bernd W. , Teichmann Georg A.
Published: July 2010

In den Jahren 2006 und 2007 sind bei Firmenübernahmen mit einem Transaktionswert von mehr als 50 Mio. US‐Dollar überwiegend strategische Bieter zum Zuge gekommen. Zunehmend gilt die Spezialchemie als lohnendes Investitionsobjekt.
“In manchen Fällen brauchen wir das Gesetz”
Authors: Wolfmeier Uwe , Guggolz Ernst
Published: July 2010

Nicht erst mit Reach ist die chemische Industrie vom Hersteller bis zum Lieferanten an den Endverbraucher für die Sicherheit ihrer Produkte verantwortlich. Wer treibt bei der Produktsicherheit die Branche und den Wandel? Im Gespräch mit den Nachrichten aus der Chemie berichtet Uwe Wolfmeier, bei Clariant verantwortlich für die Produktsicherheit.
Paris und Ulm: So tagten wir
Authors: Schorsch Gilbert
Published: July 2010

SFC 07 Paris – WiFo Ulm: Dabei handelt es sich nicht um eine deutsch‐französische Fußballbegegnung sondern um zwei Kongresse, welche die französische SFC und die deutsche GDCh im letzten Jahr veranstalteten. Gilbert Schorsch, ehemaliger Chefredakteur der L'Actualité Chimique und Kuratoriumsmitglied der Nachrichten, vergleicht:
Computational experience with a SDP‐based algorithm for maximum cut with limited unbalance
Authors: Galbiati Giulia , Gualandi Stefano , Maffioli Francesco
Published: July 2010

In the Maximum Cut with Limited Unbalance problem, we want to partition the vertices of a weighted graph into two sets of sizes differing at most by a given threshold B, so that the sum of the weights of the crossing edges is maximum. This problem has been introduced in (Galbiati and Maffioli, Theor Comput Sci 385 (2007), 78–87) where polynomial time randomized approximation algorithms are proposed and their performance guarantees are analyzed in the case of non‐negative integer weights. In this article, we present extensive computational experience with these algorithms on a large number of different graphs. We then extend the analysis of these algorithms to integer weights not restricted in sign, and continue the computational testing. It turns out that the approximation ratios obtained are always substantially better than those guaranteed by the theoretical analysis. © 2010 Wiley Periodicals, Inc. NETWORKS 2010
Hybrid analytical and extended finite element method (HAX‐FEM): A new enrichment procedure for cracked solids
Authors: Réthoré Julien , Roux Stéphane , Hild François
Published: July 2010

A new numerical method is proposed to estimate directly stress intensity factors at the tip of a crack in an elastic body. In the same spirit as for the extended finite element method, the approximation of the displacement field is enriched in the vicinity of the crack tip. Yet the method proposed herein differs by the way the enrichment is introduced. Instead of using partition of unity concepts, a two‐description formulation is implemented. The first one uses standard finite elements while the second one, in the vicinity of the crack tip, resorts to a few purely analytical expressions. These two descriptions are then coupled by partitioning the energy with an overlapping zone. The performance of this new enrichment technique is illustrated and compared with existing techniques by means of two examples. Copyright © 2009 John Wiley & Sons, Ltd.
Re‐examining the relationship between cranial deformation and extra‐sutural bone formation
Authors: Van Arsdale A. P. , Clark J. L.
Published: July 2010

The relationship between cranial deformation and the occurrence of extra‐sutural bones remains poorly understood. Scholars are divided about whether or not cranial deformation causes an increased occurrence of these bones, and even those who agree that deformation does have an influence often disagree about which locations on the crania are most impacted. Part of this issue clearly stems from the difficulties in finding appropriate samples from which to test the hypothesis that deformation leads to an increased expression of extra‐sutural bones. The present study examines the effects of fronto‐occipital and occipital‐only deformation on the occurrence of extra‐sutural bones through an analysis of 59 deformed and undeformed crania from the Philippines. Relative to the undeformed crania, both deformed samples showed an elevated number of extra‐sutural bones. Using two different statistical tests, we identified a significantly higher occurrence of extra‐sutural bones at two distinct cranial localities for both the fronto‐occipitally deformed crania (coronal suture and asterion) and for those showing only occipital flattening when compared to the undeformed crania (lambdoidal and asterion). However, as our data reveal, individuals with highly elevated occurrences of extra‐sutural bones are not necessarily deformed. As such, we argue that deformation practices may have a positive impact on the formation of extra‐sutural bones; however, future studies using larger samples of deformed and undeformed crania—ideally from the same site—will be necessary to distinguish between the influence of cranial deformation on extra‐sutural bone formation relative to other population factors which may play a role in shaping variation in this feature. Copyright © 2010 John Wiley & Sons, Ltd.
Continuity and change in U.S. foreign policy: Carter and reagan on el salvador
Authors: Pastor Robert
Published: July 2010

In attempting to understand continuity and change in U.S. foreign policy, analysts have tended to place too much emphasis on the importance of process and too little on that of values, interests, and strategies. In formulating policies toward the conflict in El Salvador, both the Carter and Reagan administrations were constrained by some enduring moral and political factors in the U.S. civic culture and by some fundamental processes of decision‐making, which together account for the similarities in policy between administrations. Despite such factors, each administration's remaining space for choice produced a decidedly different set of policies with different outcomes.
After the congressional veto: Assessing the alternatives
Authors: Gilmour Robert S. , Craig Barbara Hinkson
Published: July 2010

Congressional choice of effective replacements for the recently banned legislative veto will require an accurate understanding of the actual results of the now unconstitutional device. The impact of the veto varied strikingly depending on, among other things, the type and target of the veto and on the principal sites of review in Congress itself. No single mechanism will suffice. Rather a variety of devices are available and under consideration. The underlying question raised by this analysis is which effects of the veto are worth perpetuating in light of past results and stated congressional objectives.
The continuing threat of oil supply interruptions
Authors: Weyant John
Published: July 2010

The reaction of oil‐importing nations to the energy crisis of the 1970s offers insight into a common characteristic of government behavior. Nations often fail to prepare themselves for potentially disastrous crises even when the probability of crisis seems high. Policymakers seem unwilling to confront the fact, for instance, that the oil glut does not insulate importing nations against sudden interruptions in supply. In any case, the glut will very likely have evaporated by 1990, when U.S. vulnerability will be sharply intensified. Despite the favorable opportunities for stockpiling and planning during the glut, the political process appears unable to respond.
Flying high: A case study of Japanese industrial policy
Authors: Frenkel Orit
Published: July 2010

Japan's policies with respect to industry promotion consist of much more than picking winners and subsidizing them to ensure their success. The highly flexible and adaptive character of Japan's policies is illustrated by the country's efforts to enter the world aerospace industry, an industry in which Japan is handicapped by the absence of a substantial domestic market. To meet the challenge, Japan has concentrated its efforts on altering the very structure of the world market in which it hopes to compete. Japan has participated systematically in international consortia, hoping to use such consortia as a conduit for acquiring access for foreign technology and foreign markets.
From analyst to negotiator: The OMB's new role
Authors: Johnson Bruce E.
Published: July 2010

Dramatic changes in the executive and legislative budget processes over the last ten years have elevated the Office of Management and Budget (OMB) to a new position of power and importance. Within the executive branch the budget process has become more highly centralized in the president's office; and within the Congress a similar centralization has occurred. In both branches the OMB has become the key institution for coordinating the actions of the budget‐making powers. At the same time, the much‐discussed “iron triangles” explored by analysts of the budgetary system have lost much of their power to control the process. Although the OMB's active involvement in the congressional budget process diminished in 1983, the institutional relationships necessary for a more centralized budget process remain and can be reactivated to deal with the predicted enormous deficits.
Federalism and nuclear waste disposal: The struggle over shared decision making
Authors: Downey Gary L.
Published: July 2010

Traditionally the domain of federal agencies, authority to select sites for the disposal of commercial high‐level nuclear wastes has recently been expanded to include a role for host states. State opposition to earlier siting efforts had demonstrated the dificulties federal agencies faced in resolving conflict between the local population bearing the costs and the dispersed population receiving the benefits. The new model defines the agency and the state as adversarial representatives of these competing interests. An outstanding weakness, however, is that it does not clearly specify who should speak for the state, and may actually promote intrastate conflict. The adversarial approach does not provide a generic solution to the problem of federalism, but it may prove useful at the state level for selecting disposal sites for low‐level radioactive wastes and hazardous chemical wastes.
The potential for industrial policy: Lessons from the very high speed integrated circuit program
Authors: Fong Glenn R.
Published: July 2010

A Pentagon program to advance semiconductor technology offers some important empirical evidence for the national debate over industrial policy. While not an explicit attempt at promoting international competitiveness, the Very High Speed Integrated Circuit (VHSIC) program does contain a whole series of industrial policy‐like features, including joint government‐industry planning, widespread industry participation, and multifirm collaboration. These striking features cannot be attributed solely to VHSIC's affiliation with the military. Instead, the sources of the program's industrial policy characteristics are to be found in the nature of the technologies selected for development, the incorporation of private sector advice, the mitigation of threats to proprietary interests, avoidance of redistributional issues, and the utilization of industry competition and networks of communication‐all factors directly relevant to industrial policymaking generally.
Big decisions and a culture of decisionmaking
Authors: Krieger Martin H.
Published: July 2010

“Big” decisions are defined as discontinuous, abrupt, and unique, in contrast to “little” decisions, which are marginal, commensurable, and additive. We can model big decisions, as well as a wider range of little decisions, if we enlarge our notion of decisionmaking to include legal interpretation, rites‐of‐passage ritual and conversion experience, heroic leadership, critical judgment of works of literature and art, and entrepreneurship. These models are exemplary of a more encompassing “culture of decisionmaking,” involving six practices: marginalism, untouchableness, gaps, action, judgment, and entrepreneurship. Although big decisions may often be reduced to sets of little decisions, when a decision is treated as big it becomes a powerful mode of initiation, commitment, and justification of a project.
Formula budgeting: The economics and analytics of fiscal policy under rules
Authors: Hanushek Eric A.
Published: July 2010

The dramatic change in aggregate fiscal policy in recent years has contributed to a shift from process rules to allocation rules in federal budgeting. Although the allocation rules inherent in formula budgeting seem to offer fairness in times of fiscal constraint, they actually impose arbitrary program‐level budgets that reflect the peculiarities of baselines, accounting conventions, and time horizons. Formula budgeting also changes the analytical environment, forcing policy analysts to pay greater attention to institutional arrangements.
Influence of addition of styrene–ethylene/butylene–styrene copolymer on rheological, mechanical, and tribological properties of polyamide nanocomposites
Authors: Nishitani Yosuke , Ohashi Kohei , Sekiguchi Isamu , Ishii Chiharu , Kitano Takeshi
Published: July 2010

To develop new tribomaterials for mechanical sliding parts, investigations were carried out on the influence of adding styrene–ethylene/butylene–styrene block copolymer (SEBS) on the rheological, mechanical, and tribological properties of polyamide 6 (PA6) nanocomposite, which is a commercial product of layered silicate (clay) filled polyamide 6 (PA6/Clay). Two kinds of block copolymers, unmodified SEBS (SEBS) and maleic anhydride‐grafted SEBS (SEBS‐g‐MA), were added with PA6/Clay nanocomposite. Dynamic viscoelastic properties in the molten state of these nanocomposites and their tensile, impact, and tribological properties of these nanocomposites were evaluated. Dynamic viscoelastic properties were found to increase with the addition of SEBS and were influenced, in particular, by block copolymers containing SEBS‐g‐MA. Influence of the addition of SEBS on mechanical properties of these systems differed for each mechanical property. Although tensile properties decreased with SEBS, Izod impact properties were improved with the addition of SEBS‐g‐MA. Tribological properties were improved with the addition of block copolymer, and the influence of the amount of addition was higher than the type of block copolymer used. These results indicate that new tribomaterials developed have sufficient balance amongst moldability, mechanical, and tribological properties. POLYM. COMPOS., 2010. © 2009 Society of Plastics Engineers
Thyrotoxicosis resembling an eating disorder in Type 1 diabetes mellitus
Authors: Thomas DJB
Published: July 2010

A female with Type 1 diabetes, aged 24, presented with mild ketoacidosis and amenorrhea. Subsequent outpatient diabetic control remained poor (HbA1c 13, NR 4.1–5.5) and the patient admitted spending up to ±20 daily on sweets and cakes. Following referral to a psychologist, an eating disorder was diagnosed. Soon after this, thyrotoxicosis (T4 64 pmol/L, range 9–24) was diagnosed following complaints of intense hunger. However, no other usual signs of thyrotoxicosis were present. Once thyrotoxicosis was controlled on carbimazole binging decreased and diabetes control gradually improved. In retrospect the eating disorder was atypical, as vomiting, purging or disturbance of body image were absent. Currently the patient is euthyroid, off treatment, and diabetes control is good (HbA1c 7). It is suggested that thyrotoxicosis may resemble an eating disorder and that thyroid function be assessed in patients with atypical eating disorders even if clinical signs of thyrotoxicosis are absent.
Marked increase in proton pump inhibitors use in Australia
Authors: Hollingworth Samantha , Duncan Emma L , Martin Jennifer H
Published: July 2010

Objectives

To examine the trends in the prescribing of subsidised proton pump inhibitors (PPIs) and histamine receptor antagonists (H2RAs), in the Australian population from 1995 to 2006 to encourage discussion regarding appropriate clinical use. PPIs and H2RAs are the second highest drug cost to the publicly subsidised Pharmaceutical Benefits Scheme (PBS).

Design

Government data on numbers of subsidised scripts, quantity and doses for PPIs and H2RAs were analysed by gender and age, dose and indication.

Main outcome measure

Drug utilisation as DDD [defined daily dose]/1000 population/day.

Results

The use of combined PPIs increased by 1318%. Utilisation increased substantially after the relaxation of the subsidised indications for PPIs in 2001. Omeprazole had the largest market share but was substituted by its S‐enantiomer esomeprazole after its introduction in 2002. There was considerable use in the elderly with the peak use being in those aged 80 years and over. The utilisation of H2RAs declined 72% over 12 years.

Conclusions

PPI use has increased substantially, not only due to substitution of H2RAs but to expansion in the overall market. Utilisation does not appear to be commensurate with prevalence of gastro‐oesophageal reflux disease (GORD) nor with prescribing guidelines for PPIs, with significant financial costs to patients and PBS. This study encourages clinical discussion regarding quality use of these medicines. Copyright © 2010 John Wiley & Sons, Ltd.
A psycholexical Study of Virtues in the Dutch Language, and Relations between Virtues and Personality
Authors: De Raad Boele , Van Oudenhoven Jan Pieter
Published: July 2010

Following the psycholexical approach, a list of 153 virtue descriptors was selected from a previously constructed list of trait–terms, under the assumption that virtues form a subset of traits. The virtue list was administered to 400 participants (self– and other–raters), who had to indicate the extent to which each term applied to them or to the others. Principal Component Analyses were performed yielding six factors of virtues. In addition, Big Five factors and markers of an external set of virtues were constructed. Correlation and regression analyses were performed to describe the relations between virtues, the Dutch Big Five system and other virtue systems. Compared to the other virtue systems, the present study revealed some additional domains. The overlap found with personality measures corresponds to earlier findings supporting the assumption that virtues are important traits. Copyright © 2010 John Wiley & Sons, Ltd.
Field evaluation of systemic imidacloprid for the management of avocado thrips and avocado lace bug in California avocado groves
Authors: Byrne Frank J , Humeres Eduardo C , Urena Anthony A , Hoddle Mark S , Morse Joseph G
Published: July 2010

BACKGROUND: The efficacy of systemic applications of imidacloprid for the management of avocado thrips and avocado lace bug was determined in field trials. Following insecticide treatment by chemigation, leaves of appropriate age for each insect were sampled over a 6 month period and used for bioassays. Imidacloprid residues were measured by ELISA in leaves used for bioassays to determine concentrations of insecticide that were toxic to both pests.

RESULTS: The uptake of imidacloprid into treated trees was extremely slow, peaking in the current year's leaf flush at only 8 ng cm−2 leaf tissue after 15 weeks. Avocado thrips mortality in bioassays with young flush leaves, the preferred feeding substrate for this insect, was minimal, indicating that imidacloprid concentrations were below threshold levels needed for effective control. Residues present in older leaves, which are preferred by the avocado lace bug, were higher than in young flush leaves, and provided good control of this pest. Probit analysis of bioassay data showed that the avocado lace bug (LC50 = 6.1 ng imidacloprid cm−2 leaf tissue) was more susceptible to imidacloprid than the avocado thrips (LC50 = 73 ng imidacloprid cm−2 leaf tissue).

CONCLUSIONS: In spite of the slow uptake of imidacloprid into avocado trees, the levels of imidacloprid would be sufficient to control avocado lace bug infestations. In contrast, the slow uptake would be problematic for avocado thrips control because inadequate levels of insecticide accumulate in new flush foliage and would allow avocado thrips populations to build to levels that would subsequently damage developing avocado fruit. Copyright © 2010 Society of Chemical Industry
New‐build gentrification: its histories, trajectories, and critical geographies
Authors: Davidson Mark , Lees Loretta
Published: July 2010

New‐build gentrification has been the subject of renewed attention of late. The impetus was Lambert and Boddy, who asserted that inner‐city new‐build developments in British city centres should not be viewed as a form of gentrification. While the term has long been generally accepted, Lambert and Boddy, and, more recently, Boddy, argue that the demographic transformations stimulated by city centre new‐build developments are relatively innocuous. They do not cause population displacement, and are not associated with the rent‐hike and eviction processes of gentrification proper. Indeed, within a move to rethink the workings and consequences of gentrification more generally (e.g. Butler), there has been a new questioning of whether this, or any, contemporary form of gentrification produces significant displacement concerns. In this paper, we address these new debates. We begin by tracing the histories of new‐build gentrification, highlighting its long‐standing presence, and then we move on to look at its trajectories, focusing our lens on London to demonstrate the diversity and complexity of this process in just one city. We outline the presence of displacement – both direct and indirect – as a complex and nuanced process (not just a spatial moment), but one that has nevertheless had a real‐life impact on real people. Copyright © 2009 John Wiley & Sons, Ltd.
Carrier dynamics in InS nanowires grown via chemical vapor deposition
Authors: Othonos Andreas , Zervos Matthew
Published: July 2010

Transient femtosecond absorption spectroscopy and time‐correlating single photon counting (TCSPC) photoluminescence (PL) were employed to study InS nanowires (NWs) grown by chemical vapor deposition (CVD) and determine the relaxation mechanisms in these nanostructures. Intensity dependent measurements revealed that Auger recombination plays an important role in the relaxation of photogenerated carriers at fluences larger than 0.4 × 1015 photons/cm2. Calculations provided an estimated of the Auger recombination coefficient to be 1.1 ± 0.5 × 10−31 cm6/s. At the low fluence regime TCSPC PL revealed three relaxation mechanisms with time constants ranging from ps to nanosecond providing evidence of the importance of non‐radiative decay channels associated with defect/trap states within the NWs.

magnified image

Auger recombination appears to dominate the carrier dynamics in InS NWs with increasing incident photon flux.
The substrate orientation dependence of GaAsSb thin layer and GaSb dots grown by molecular layer epitaxy
Authors: Ohno Takeo , Oyama Yutaka , Sato Shota
Published: July 2010

A GaAs/GaAsSb/GaAs structure was grown on (100), (111)A, (111)B and (110) GaAs substrates by intermittent injection of AsH3, TEGa, and TMSb. The maximum Sb composition was GaAs0.79Sb0.21 on (100) GaAs. From the SIMS, PL and XRD measurements, the abruptness of the quantum well interface and lattice strain were discussed. The growth of GaSb dot was also carried out, and a 20 nm average diameter and a dot density of 7×1010 cm–2 were achieved on (111)A. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Antiaggregation potential of berry fractions against pairs of Streptococcus mutans with Fusobacterium nucleatum or Actinomyces naeslundii
Authors: Riihinen Kaisu , Ryynänen Anu , Toivanen Marko , Könönen Eija , Törrönen Riitta , Tikkanen‐Kaukanen Carina
Published: July 2010

Coaggregation is an interspecies adhesion process, which is essential to the development of dental plaque. This is an in vitro study of the composition of the soluble solids in the berry juice molecular size fractions (<10 kDa, FI; 10–100 kDa, FII; >100 kDa, FIII) derived from apple, bilberry, blackcurrant, cloudberry, crowberry and lingonberry and their ability to inhibit and reverse coaggregation of the pairs of common species in dental plaque: Streptococcus mutans with Fusobacterium nucleatum or Actinomyces naeslundii. Inhibitory and reversal activity was found in the molecular size fractions FII and FIII of bilberry, blackcurrant, crowberry and lingonberry. The active fractions contained higher amounts of polyphenols (5–12% of soluble solids) than those without activity (<2% of soluble solids). Proanthocyanidins dominated in the active lingonberry juice fractions FII and FIII and also small amounts of anthocyanins were detected. Anthocyanins, proanthocyanidins and flavonol glycosides were prevalent in FII and FIII fractions of bilberry, blackcurrant and crowberry juices. Comparable amounts of sugars and titratable acids were present in the latter three berry juice fractions of different size. The results indicate that the high molecular size fractions of lingonberry, bilberry, blackcurrant and crowberry juices have antiaggregation potential on common oral bacteria, the potential being associated with their polyphenolic content. Copyright © 2010 John Wiley & Sons, Ltd.
Glyoxal oligomers: A computational study
Authors: Solimannejad Mohammad , Massahi Shokofeh , Alkorta Ibon
Published: July 2010

Ab initio calculations at MP2/6‐311++G(2d,2p) computational level was used to analyze interactions between glyoxal (OCHCHO) dimers and trimers in the gas phase. The structures obtained have been analyzed with the atoms in molecules and natural bond orbital methodologies. Eight minima were located on the potential energy surface of the dimers. Eighteen different structures have been obtained for the trimers. CH···O type of interactions is clustering OCHCHO molecules in studied oligomers. Stabilization energies of dimers and trimers including basis set superposition error and ZPE corrections are in the range 4–8 kJ mol−1and 12–19 kJ mol−1, respectively. Blue shift of CH bond upon complex formation in the ranges between 30–45 and 30–55 cm−1was predicted for dimers and trimers, respectively. © 2010 Wiley Periodicals, Inc. Int J Quantum Chem, 2011
Effect of solute flexibility and polarization on the solvatochromic shift of a brominated merocyanine dye in water: A sequential MD/QM study
Authors: Malaspina Thaciana , Fileti Eudes Eterno , Bastos Erick Leite
Published: July 2010

A sequential molecular dynamics/quantum mechanics (MD/QM) procedure was used to investigate the effects of solute polarization and flexibility on the solvatochromism of a brominated merocyanine dye (MeBM) in water. Relevant structures for the solution were generated using MD simulations. The structural analysis indicates that the flexibility of MeBM is limited; showing small amplitudes both for dihedral isomerization and for the angle formed between the normal vectors of the pyridine and phenolate rings. The solvatochromic shift in the π–π* electronic transition was studied using both the PM6/CI and PM6/CI/COSMO methods in the gas phase as well as in the solution phase (solute + first solvation shell). The results obtained with the use of the hybrid polarizable continuum model/discrete description are in good agreement with available experimental values and indicate that the polarization of the solute plays a more significant role in the solvatochromism of MeBM than its flexibility. © 2010 Wiley Periodicals, Inc. Int J Quantum Chem, 2010
Gas‐phase acylium ion transfer reactions mediated by a proton shuttle mechanism
Authors: Fileti Eudes E. , De Oliveira Anselmo E. , Morgon Nelson H. , Riveros José M.
Published: July 2010

The mechanism and the energy profile of the gas‐phase reaction that mimics esterification under acidic conditions have been investigated at different levels of theory. These reactions are known to proceed with rate constants close to the collision limit in the gas‐phase and questions have been raised as to whether the typical addition‐elimination mechanism via a tetrahedral intermediate can explain the ease of these processes. Because these reactions are common to many organic and biochemical processes it is important to understand the intrinsic reactivity of these systems. Our calculations at different levels of theory reveal that a stepwise mechanism via a tetrahedral species is characterized by energy barriers that are inconsistent with the experimental results. For the thermoneutral exchange between protonated acetic acid and water and the exothermic reaction of protonated acetic acid and methanol our calculations show that these reactions proceed initially by a proton shuttle between the carbonyl oxygen and the hydroxy oxygen of acetic acid mediated by water, or methanol, followed by displacement at the acylium ion center. These findings suggest that the reactions in the gas‐phase should be viewed as an acylium ion transfer reaction. © 2010 Wiley Periodicals, Inc. Int J Quantum Chem, 2010
Theoretical study of morphine and heroin: Conformational study in gas phase and aqueous solution and electron distribution analysis
Authors: Rincón David A. , Cordeiro M. Natália D. S. , Mosquera Ricardo A.
Published: July 2010

The conformational preferences of morphine and heroin were studied in gas phase and with inclusion of solvent effects. At 298.15 K, three conformers are significant for isolated morphine, all of them displaying antiperiplanar arrangement for the C2C3OH unit, and there is only one significantly populated conformer for heroin. Quantum theory of atoms in molecules analysis of the electron density in their most populated conformers in gas phase indicates that the positive charge is shared among the amino hydrogen, those hydrogens of the methylamino group, and all of the hydrogens attached to the bridgehead carbons. © 2010 Wiley Periodicals, Inc. Int J Quantum Chem 110:2472–2482, 2010
An efficient recursive algorithm to compute wave function optimization gradients for the graphically contracted function method
Authors: Shepard Ron , Gidofalvi Gergely , Hovland Paul D.
Published: July 2010

An efficient recursive algorithm is presented to compute orbital‐level Hamiltonian matrices for wave functions expanded in a basis of graphically contracted functions (GCF). Each GCF depends on a nonlinear set of parameters called arc factors. The orbital‐level Hamiltonian matrices characterize the dependence of the energy on the wave function changes associated with a subset of these nonlinear parameters corresponding to an individual molecular orbital. From these Hamiltonian matrices, gradients with respect to the nonlinear arc factor parameters may be computed and other arc factor optimization algorithms may be used. The recursive algorithm allows the orbital‐level Hamiltonian matrices to be computed with O(Nωn4) total effort, where NGCF is the dimension of the GCF basis, n is the dimension of the orbital basis, and where the scale factor ω depends on the number of electrons N and ranges from O(N0) to O(N2) depending on the complexity of the underlying Shavitt graph. This effort is about two to five times that required to compute an energy expectation value for a given set of arc factors; thus the energy and gradient have the same scaling behavior with increasing molecule size, NGCF dimension, and orbital basis size. Timings are given for wave functions that correspond to configuration state function expansions over 1073 in length, many orders of magnitude larger than can be considered using traditional electronic structure methods. © 2010 Wiley Periodicals, Inc. Int J Quantum Chem, 2010
Laser‐based rut detection and following system for autonomous ground vehicles
Authors: Ordonez Camilo , Chuy Oscar Y. , Collins Emmanuel G. , Liu Xiuwen
Published: July 2010

An important off‐road driving rule is to keep the vehicle wheels in existing ruts when possible. Rut following has the following benefits: (1) it prevents the ruts from serving as obstacles that can lead to undesirable vehicle vibrations and even vehicle instability at high speeds; (2) it improves vehicle safety on turns by utilizing the extra lateral force provided by the ruts to reduce lateral slippage and guide the vehicle through its path; (3) it improves the vehicle energy efficiency by reducing the energy wasted on compacting the ground; and (4) it increases vehicle traction when traversing soft terrains such as mud, sand, and snow. This paper first presents a set of field experiments that illustrate the improved energy efficiency and traction obtained by rut following. Then, a laser‐based rut detection and following system is proposed so that autonomous ground vehicles can benefit from the application of this off‐road driving rule. The proposed system utilizes a path planning algorithm to aid in the rut detection process and an extended Kalman filter to recursively estimate the parameters of a local model of the rut being followed. Experimental evaluation on a Pioneer 3‐AT robot shows that the proposed system is capable of detecting and following ruts in a variety of scenarios. © 2010 Wiley Periodicals, Inc.
The impact of small physical obstacles on the structure of freshwater fish assemblages
Authors: Alexandre C. M. , Almeida P. R.
Published: July 2010

Many studies have assessed the effects of large dams on fishes but few have examined the effects of small obstacles. Fishes were sampled and environmental variables were characterized at 28 sites in two Iberian streams, 14 located immediately downstream, upstream and between five small obstacles at river Muge and 14 at river Erra, considered as the reference stream. Multivariate analysis indicated that habitat variables like current velocity and depth, but not physicochemistry, were mainly responsible for site groups' discrimination in both streams. The reference stream exhibited a longitudinal gradient of current velocity that, however, was not strong enough to cause significant changes in the fish assemblage's composition and structure. By successive and drastically repeating this gradient near each structure, the obstacles stream presented differences in fish fauna between the three site types. Lentic upstream sites presented higher density of limnophilic, omnivorous and exotic species, like gudgeon Gobio lozanoi, which are well adapted to this type of habitat. Downstream and between obstacles sites were characterized by the dominance of rheophilic and invertivorous taxa, especially barbel Luciobarbus bocagei. Richness metrics did not differ among site types, but diversity was higher in sites located between the obstacles away from its direct influence, where the habitat diversity was higher. Contrarily to upstream sites, downstream and between obstacles sites were similar in many of the studied features to the reference stream, implying that this type of structures cause a higher modification in the upstream fish community. This study suggests that the effects of small obstacles on habitat and fishes are similar, in some extent, to those reported for larger dams, providing important considerations for riverine ecosystem conservation efforts. Copyright © 2009 John Wiley & Sons, Ltd.
Multicategory composite least squares classifiers
Authors: Young Park Seo , Liu Yufeng , Liu Dacheng , Scholl Paul
Published: July 2010

Classification is a very useful statistical tool for information extraction. In particular, multicategory classification is commonly seen in various applications. Although binary classification problems are heavily studied, extensions to the multicategory case are much less so. In view of the increased complexity and volume of modern statistical problems, it is desirable to have multicategory classifiers that are able to handle problems with high dimensions and with a large number of classes. Moreover, it is necessary to have sound theoretical properties for the multicategory classifiers. In the literature, there exist several different versions of simultaneous multicategory support vector machines (SVMs). However, the computation of the SVM can be difficult for large scale problems, especially for problems with large number of classes. Furthermore, the SVM cannot produce class probability estimation directly. In this article, we propose a novel efficient multicategory composite least squares classifier (CLS classifier), which utilizes a new composite squared loss function. The proposed CLS classifier has several important merits: efficient computation for problems with large number of classes, asymptotic consistency, ability to handle high‐dimensional data, and simple conditional class probability estimation. Our simulated and real examples demonstrate competitive performance of the proposed approach. Copyright © 2010 Wiley Periodicals, Inc. Statistical Analysis and Data Mining 3: 272‐286, 2010
Cathodoluminescence and computer graphics in materials science
Authors: Nazarov M. V. , Nazarova T. A.
Published: July 2010

The combination of cathodoluminescence (CL) in scanning electron microscopy (SEM) with computer graphics is proposed for studying semiconductors and dielectric materials. Spatial distribution of several types of defects that occurred naturally and by design in crystals, can be sorted out and visualized in CL mapping and in three‐dimensional images reconstructed in scanning cathodoluminescence microscopy. The possibilities of this method are illustrated on magnesium oxide single crystals indented with a Vickers diamond pyramid.
Color cathodoluminescence of BGO crystals
Authors: Nazarova T. A. , Nazarov M. V. , Saparin G. V. , Obyden S. K.
Published: July 2010

The color cathodoluminescence (CL) mode in scanning electron microscopy (SEM) is promising in the study of a variety of defects in single crystals pulled from the melt by the Czochralski method. The regions of homogeneous and heterogeneous capture of impurities and of point and linear defects, which affect the luminescence in the undoped Bi4Ge3O12 (BGO) and doped BGO:V, BGO:Yb, BGO:Cr3+, and BGO:Fe as grown single crystals, were observed. Depending on the doped impurities and dislocation configuration, a change was found in both the intensity and wavelength of CL.
Contamination in a scanning electron microscope and the influence of specimen cooling
Authors: Hirsch P. , Kässens M. , Püttmann M. , Reimer L.
Published: July 2010

Solutions of the stationary and time‐dependent equations of diffusion are presented for contamination when scanning a rectangular area in the scanning electron microscope (SEM). A method is described to record the thickness of the contamination layer by the signal of secondary or backscattered electrons and to measure the influence of electron current density, beam energy, and specimen cooling on the contamination rate.
The intracellular distribution of vinculin and alpha2 integrin in epithelial cells and chondrocytes
Authors: Hirsch M. S. , Law L. Y. , Trinkaus‐Randall V. , Svoboda K. K. H.
Published: July 2010

The purpose of this study was to demonstrate the presence of vinculin and alpha2 integrin in chondrocytes in situ and epithelial cells. We also determined that the appropriate fixation and extraction protocols for immunohistochemistry and laser scanning confocal microscopy for an integral membrane protein and an actin‐associated protein in cultured cells and whole tissue was different. Cultured epithelial cells, whole mount human cornea and avian cartilage were fixed and prepared using a number of standard procedures used for indirect fluorescence immunohistochemistry. The distribution of vinculin was cell‐type and fixation‐specific. Chondrocytes and cultured epithelial cells demonstrated vinculin in areas that appear to be associated with filamentous actin. Vinculin was associated with cell membranes in human cornea. The expression of alpha2 integrin observed in chondrocytes fixed with methanol, paraformaldehyde, or formaldehyde is consistent with its role in cell–substrate interaction, but may also suggest a role in dividing and differentiating cells. The localization of alpha2 integrin in human corneal epithelia supports its role as a cell‐cell adhesion molecule. The cytoplasmic distribution of vinculin and alpha2 integrin in tissues fixed without detergent extraction suggests that the fixation step may be sufficient for antibody penetration and antigen extraction. These studies are the first report of vinculin and alpha2 integrin in embryonic chondrocytes. In addition we have shown that confocal laser scanning microscopy combined with proper fixation and extraction protocols may optimize the localization of antigens in cultured and whole mount cells.