bluuebunny/crossref_metadata_2025 huggingface dataset:
Retail Assortment Planning in the Presence of Consumer Search
Authors: Cachon Gérard P. , Terwiesch Christian , Xu Yi
Published: November 2005

Consumers often know what kind of product they wish to purchase, but do not know which specific variant best fits their needs. As a result, a consumer may find an acceptable product in one retailer but nevertheless purchase nothing, opting to search other retailers for an even better product. We study several models of retail assortment planning, some of which explicitly account for consumer search and one that does not, which we call the “no-search” model. Even though the no-search model never includes an unprofitable variant in the assortment, in the presence of consumer search, it may indeed be optimal to include an unprofitable variant. Furthermore, we find that the no-search model can lead to an assortment with an expected total profit that is significantly less than optimal. In the extreme, the no-search model may recommend closing down a category (i.e., carry no variants) even if a profitable assortment exists (a 100% profit loss). We conclude that failing to incorporate consumer search into an assortment planning process may cause a retailer to underestimate the substantial value a broad assortment has in preventing consumer search. We discuss how the insights from our stylized models may apply to actual assortment planning processes.
Biform Analysis of Inventory Competition
Authors: Stuart Harborne W.
Published: November 2005

This paper provides a model of the competitive newsvendor problem in which there is price competition following the inventory decisions. Using the biform game formalism of Brandenburger and Stuart (2004), the price competition is modeled by considering the core of the induced cooperative game. Such an analysis allows price competition to be modeled without a priori assumptions about price-setting power or pricing procedures. The paper shows that with no uncertainty, the inventory decision is equivalent to the capacity decision in Cournot competition. With uncertainty, the analysis again reduces to Cournot competition if the demand uncertainty is characterized by an appropriately constructed, expected demand curve. The results highlight the critical role of the fixed-price assumption in newsvendor models.
Decision-Aiding Methodology for the School Bus Routing and Scheduling Problem
Authors: Spada M. , Bierlaire M. , Liebling Th. M.
Published: November 2005

We consider the school bus routing and scheduling problem, where transportation demand is known and bus scheduling can be planned in advance. We present a comprehensive methodology designed to support the decision of practitioners. We first propose a modeling framework where the focus is on optimizing the level of service for a given number of buses, then we describe an automatic procedure generating a solution to the problem. The procedure first builds a feasible solution, which is subsequently improved using a heuristic.

We analyze two important issues associated with this methodology. On the one hand, we analyze the performance of three types of heuristics both on real and synthetic data. We recommend the use of a simulated annealing technique exploring infeasible solutions, which performs slightly better than all others. More importantly, we find that the performance of all heuristics is not globally affected by the choice of the parameters. This is important from a practitioner viewpoint, because the fine-tuning of algorithm parameters is not critical for the algorithm’s performance. We have successfully applied our methods on real problems and on large-scale problems. On the other hand, we propose an interactive tool allowing the practitioner to visualize the proposed solution, to test its robustness, and to dynamically rebuild new solutions if the data of the original problem are modified.
Maintenance Routing for Train Units: The Transition Model
Authors: Maróti Gábor , Kroon Leo
Published: November 2005

Train units need regular preventive maintenance. Given the train units that require maintenance in the forthcoming one to three days, the rolling stock schedule must be adjusted so that these urgent units reach the maintenance facility in time. Maróti and Kroon (2004) propose a model that requires a large amount of input data. In this paper we describe a less involved multicommodity flow type model for this maintenance routing problem. We study the complexity of the problem. It turns out that the feasibility problem for a single urgent train unit is polynomially solvable but the optimization version is NP-hard. Finally, we report our computational experiments on practical instances of NS Reizigers, the main Dutch operator of passenger trains.
A Multiple Pairs Shortest Path Algorithm
Authors: Wang I-Lin , Johnson Ellis L. , Sokol Joel S.
Published: November 2005

The multiple pairs shortest path problem (MPSP) arises in many applications where the shortest paths and distances between only some specific pairs of origin-destination (OD) nodes in a network are desired. The traditional repeated single-source shortest path (SSSP) and all pairs shortest paths (APSP) algorithms often do unnecessary computation to solve the MPSP problem. We propose a new shortest path algorithm to save computational work when solving the MPSP problem. Our method is especially suitable for applications with fixed network topology but changeable arc lengths and desired OD pairs. Preliminary computational experiments demonstrate our algorithm’s superiority on airline network problems over other APSP and SSSP algorithms.
On a Paradox of Traffic Planning
Authors: Braess Dietrich , Nagurney Anna , Wakolbinger Tina
Published: November 2005

For each point of a road network, let there be given the number of cars starting from it, and the destination of the cars. Under these conditions one wishes to estimate the distribution of traffic flow. Whether one street is preferable to another depends not only on the quality of the road, but also on the density of the flow. If every driver takes the path that looks most favorable to him, the resultant running times need not be minimal. Furthermore, it is indicated by an example that an extension of the road network may cause a redistribution of the traffic that results in longer individual running times.
ARMin – Roboter für die Bewegungstherapie der oberen Extremitäten (ARMin – Robot for Movement Therapy of the Upper Extremities)
Authors: Nef Tobias , Colombo Gery , Riener Robert
Published: November 2005

Aufgabenorientierte, repetitive Bewegungen können die motorische Erholung bei Patienten mit inkompletter Querschnittlähmung, Halbseitenlähmung oder orthopädischen Verletzungen verbessern. Dieser Artikel stellt die Technik des neuen Therapieroboters ARMin vor. ARMin unterstützt das Training von funktionellen Bewegungen und Aktivitäten des täglichen Lebens der oberen Extremitäten.
Belastungsregelung bei der Elektrostimulationsergometrie (Power Control of Electrical Stimulation Induced Cycle Ergometry)
Authors: Schauer Thomas , Salbert Robert C. , Negård Nils-Otto , Hunt Kenneth J. , Raisch Jörg
Published: November 2005

Für querschnittgelähmte Menschen stellt das Herz-Kreislauf-Training an Fahrradergometern mit Funktioneller Elektrischer Stimulation (FES) der gelähmten unteren Extremitäten eine sich zunehmend etablierende Rehabilitationsmaßnahme dar. Diese Arbeit stellt ein neues Ergometersystem mit Elektrostimulation vor, bei dem die Beine zusätzlich durch einen Hilfsmotor unterstützt werden. Durch den Motor kann ein isokinetisches Training realisiert werden. Der Patient arbeitet in diesem Fall mit den elektrisch stimulierten Muskeln gegen den Motor, der die Trittgeschwindigkeit konstant hält. Für die gezielte Anpassung der Belastung durch die Elektrostimulation wurde ein sich selbst einstellender Momentenregler entwickelt. Der Reglerentwurf erfolgt anhand der online identifizierten linearen Übertragungsfunktion zwischen Stimulationsintensität und gemitteltem muskulären Antriebsmoment. Erste experimentelle Ergebnisse mit einem neurologisch intakten Probanden werden vorgestellt.
Komponenten und Architektur eines navigierten Assistenzroboters für chirurgische Anwendungen (Components and Architecture of a Navigated Robot System for Surgical Applications)
Authors: Knappe Peter , Pieck Sebastian , Wahrburg Jürgen
Published: November 2005

Der Beitrag beschreibt ein universelles Chirurgieassistenzsystem, das durch die Kombination von Navigation und Robotik gekennzeichnet ist und eine neue, in hohem Maße interaktive Arbeitsweise der Roboter-Komponente realisiert. Damit wird es möglich, die spezifischen Vorteile beider Systemkomponenten auszunutzen: Das Navigationssystem dient zur genauen und schnellen Registrierung der Patientenanatomie mit Hilfe eines elektro-optischen 3D-Digitalisiersystems, während der Roboterarm als mechatronische Ergänzung der Navigation zur Führung und Positionierung der chirurgischen Instrumente eingesetzt wird und Probleme durch Abrutschen oder Zittern vermeidet. Außerdem ist es möglich, den Roboterarm bei kleinen Patientenbewegungen on-line nachzuführen, sodass die räumliche Zuordnung zwischen Patientenstruktur und chirurgischem Werkzeug stets erhalten bleibt. In diesem Beitrag wird vor allem die erzielbare statische Systemgenauigkeit diskutiert.
Immobilization of actinide ions in thin layers of polypyrrole/polyacrylamidoglycolic acid (PPy/PAGA) composite. Application to the preparation of alpha spectrometry sources
Authors: Leroy D. , Martinot L. , Mignonsin P. , Lambert B. , Jérôme C. , Jérôme R.
Published: November 2005

We propose a new fully aqueous electrochemical method for the preparation of high resolution alpha sources. Thin films of polypyrrole (PPy) are prepared by anodic electropolymerization, starting from aqueous solutions of the pyrrole monomer and an anionic polyelectrolyte which is able to complex actinide and play the role of PPy doping agent: polyacrylamidoglycolic acid (PAGA). These thin films can be prepared on various electrodes: stainless steel, platinum, glassy carbon and polyethylene doped by carbon-black. Peeling tests revealed their strong adhesion on stainless steel electrode. Alpha sources were prepared by simple immersion in actinide containing solutions. This easy process results in alpha sources with outstanding energy resolution (FWHM: around 9 keV for various isotopes).
Modeling the Oxygen Consumption Rates in Pacific Salmon and Steelhead: Model Development
Authors: Trudel Marc , Welch David W.
Published: November 2005

We derived a series of models for estimating the standard metabolic rates, swimming costs, and total metabolic rates for sockeye salmon Oncorhynchus nerka and steelhead O. mykiss. The performance of these models was compared statistically and used to predict optimal cruising speeds. These predictions were tested with independent estimates of swimming speed obtained under field conditions. Standard metabolic rates were correlated with body mass and temperature. Swimming costs were correlated with body mass and swimming speed, whereas total metabolic rates were correlated with body mass, water temperature, and swimming speed. Swimming costs were also correlated with temperature and salinity in steelhead but not in sockeye salmon. Regression models accounted for 94–99% of the variance in standard metabolic rates, swimming costs, and total metabolic rates. The oxygen consumption rate models we derived for sockeye salmon were inadequate for describing oxygen consumption in other species of Pacific salmon, Oncorhynchus spp., indicating that the practice of borrowing parameters from closely related species can induce serious biases in model predictions. The models derived in this study also produced realistic estimates of swimming speed in sockeye salmon but not in steelhead. The models derived in this study appear to be useful in estimating swimming speed and total metabolic rates of sockeye salmon in the field but are not appropriate predictors for other species of Pacific salmon.
Geostatistical Analysis of the Abundance and Winter Distribution Patterns of the Blue CrabCallinectes sapidusin Chesapeake Bay
Authors: Jensen Olaf P. , Miller Thomas J.
Published: November 2005

Spatial heterogeneity is a striking life history feature of the blue crabCallinectes sapidusin the Chesapeake Bay. Spatial patterns of sex‐ and age‐specific habitat use have been well documented and affect the fisheries in the bay. However, a quantitative assessment of the spatial distribution of blue crabs during winter, when they are generally buried in the sediments, has been lacking. We applied geostatistical techniques (variogram modeling and kriging) to 13 years of winter dredge survey (WDS) data to map patterns of blue crab winter abundance. These maps were then quantified to derive a time series of baywide abundance and to examine changing patterns of habitat use and aggregation. Geostatistical abundance estimates were generally similar to those calculated from design‐based methods but were more highly correlated with fishery catch per unit of effort. Both abundance time series showed a large and significant decline from 1990 to 2002. Changes in spatial distribution were evaluated using trend maps and a density‐weighted centroid. Interannual variation in the latitude of the weighted centroid was positively correlated with baywide abundance, suggesting possible density‐dependent changes in distribution. The southward shift in winter distribution at low stock size may increase the vulnerability of blue crabs to exploitation in a winter dredge fishery that occurs only in the southern portion of the bay. Such quantitative and spatially explicit information provides a potentially useful base for constructing population models and evaluating alternative management options.
Physiological Effects of Swim Bladder Overexpansion and Catastrophic Decompression on Red Snapper
Authors: Rummer Jodie L. , Bennett Wayne A.
Published: November 2005

The commercial and recreational harvests of red snapper Lutjanus campechanus in the Gulf of Mexico have declined over the past five decades, prompting strict regulations. Release mortality associated with catastrophic decompression (CD) is a possible cause for the continuing decline, although to date no physiological data exist to support this assumption. Using a flow‐through high‐pressure chamber, subadult red snapper were acclimated to 101.2, 405.3, 608.0, and 1,215.9 kPa, simulating depths typical of their distribution (as deep as 200 m), and then decompressed at a rate of 10.1 kPa/s. Lateral and dorsal X‐ray imaging in combination with necropsy showed that swim bladders expanded in a predictable manner. Ventral expansion into the caudal body cavity space occurred at lower pressures, whereas expansion into the cranial portion of the body cavity occurred at the highest pressure. Expansion patterns resulted in over 70 different overexpansion injuries, the most severe being to vital organs. Our results suggest a specific suite of clearly identifiable injuries associated with CD that increase in number and severity as retrieval depth increases. A more thorough understanding of catastrophic decompression syndrome will provide insight into the declining fishery and aid in developing effective physiology‐based management strategies.
Upstream Migration of Minijack (Age‐2) Chinook Salmon in the Columbia River: Behavior, Abundance, Distribution, and Origin
Authors: Beckman Brian R. , Larsen Donald A.
Published: November 2005

It has recently been demonstrated that a large percentage of yearling Chinook salmon Oncorhynchus tshawytscha smolts released from a production‐scale hatchery on the Yakima River display an underappreciated life history strategy. Instead of migrating to the ocean for long‐term rearing and growth, males may instead undertake a short‐term migration downstream, turn around, and migrate back upstream where they reproductively mature at age 2. Following local hatchery traditions, these fish are referred to as “minijacks.” We used information produced from (1) large‐scale passive integrated transponder (PIT)‐tagging programs at hatcheries in the Columbia and Snake River basins and (2) the installation of PIT tag detectors in the fish passage ladders built into dams on these rivers to investigate the occurrence, behavior, distribution, and origin of minijacks. A minijack was operationally defined as a fish detected in a ladder after 1 June in the same year it was released. Minijacks were found in every hatchery release group of more than 7,500 PIT‐tagged Chinook salmon smolts reported (2002, 13 groups; 2003, 15 groups). Minijack population migration upstream past Bonneville Dam peaked in late June and July. This lagged migrations of age‐4 adults (from the same populations) by approximately 2 months. However, minijacks also displayed population‐specific variation in timing of upstream migrations past Bonneville Dam; minijacks from spring Chinook salmon populations appeared before fall Chinook salmon populations. Detection rates of minijacks at all dams ranged from 0.02% to 0.33% of the total smolts released for different hatchery groups. Expansion of this rate, based on the relation between minijack estimates at Cle Elum Hatchery (before release) and detections at Bonneville Dam (after release), suggests that minijack abundance in the Columbia and Snake River basins exceed hundreds of thousands of fish.
Effects of Environmental Conditions during Stream, Estuary, and Ocean Residency on Chinook Salmon Return Rates in the Skagit River, Washington
Authors: Greene Correigh M. , Jensen David W. , Pess George R. , Steel E. Ashley , Beamer Eric
Published: November 2005

We predicted 22 years of return rates for wild Chinook salmonOncorhynchus tshawytschaas a function of environmental conditions experienced during residency in freshwater, tidal delta, bay, and ocean habitats as well as as an indicator of density dependence (based on egg production) across life stages. The best predictors of return rate included the magnitude of floods experienced during incubation, a principal components factor describing environmental conditions during bay residency, a similar factor describing conditions experienced during the third ocean year, and an estimate of egg production. Our models explained up to 90% of the variation in return rate and had a very high forecasting precision, yet environmental conditions experienced during ocean residency explained only 5% of the variation. Our results suggest that returns of wild Chinook salmon can be predicted with high precision by incorporating habitat residency and that freshwater and nearshore environmental conditions strongly influence the survival of Skagit River Chinook salmon.
Fish Assemblages in Oxbow Lakes Relative to Connectivity with the Mississippi River
Authors: Miranda L. E.
Published: November 2005

The alluvial valley of the lower Mississippi River contains hundreds of fluvial lakes that are periodically connected to the river during high water, although the frequency, duration, and timing of the connections vary. To help design plans to restore and preserve fish assemblages in these alluvial lakes, this investigation tested whether predictable patterns in lake fish assemblages were linked to the level of connectivity with the river. Results suggested that connectivity played an important role in structuring fish assemblages and that it was correlated with variables such as lake size, depth, distance from the river, and age, which exhibit a continuum of predictable features as the river migrates away from abandoned channels. Annual floods homogenize the floodplain and promote connectivity to various degrees, allowing for fish exchanges between river and floodplain that directly affect fish assemblages. The major physical changes linked to reduced connectivity are loss of depth and area, which in turn affect a multiplicity of abiotic and biotic features that indirectly affect community structure. In advanced stages of disconnection, fish assemblages in oxbow lakes are expected to include largely species that thrive in turbid, shallow systems with few predators and low oxygen content. When the river flowed without artificial restraint, oxbow lakes were created at the rate of 13–15 per century. At present, no or few oxbow lakes are being formed, and as existing lakes age, they are becoming shallower, smaller, and progressively more disconnected from the river. Given that modifications to the Mississippi River appear to be irreversible, conservation of this resource requires maintenance of existing lakes at a wide range of aging phases that provide diverse habitats and harbor distinct species assemblages.
Hard Palate Repair Timing and Facial Growth in Cleft Lip and Palate: A Systematic Review
Authors: Liao Yu-Fang , Mars Michael
Published: November 2005

Objective:

To evaluate the effect of timing of hard palate repair on facial growth in patients with cleft lip and palate, with special reference to cranial base, maxilla, mandible, jaw relation, and incisor relation.

Design:

A systematic review.

Methods:

The search strategy was based on the key words “facial growth,” “cleft lip palate,” and “timing of (hard) palate repair.” Case reports, case-series, and studies with no control or comparison group in the sample were excluded.

Results:

Fifteen studies met the selection criteria. All the studies were retrospective and nonrandomized. Five studies used cephalometry and casts, seven used cephalometry, and three used casts. Methodological deficiencies and heterogeneity of the studies prevented major conclusions.

Conclusion:

The review highlights the importance of further research. Prospective well-designed, controlled studies, especially targeting long-term results, are required to elucidate the effect of timing of hard palate repair on facial growth in patients with cleft lip and palate.
On the Misery of Theory without Poetry: Heidegger's Reading of Hölderlin's “Andenken”
Authors: Ronell Avital
Published: November 2005

The article considers the tendency among young theorists to forget or repress poetry. As symptom, the aberrant dissociation of poetry from theory reflects an increasing technicization, not to say impoverishment, of critical language. The theoretical elders, on the other hand, clung to poetic insight with the urgency of hunger. Focusing on tropes of greeting, celebration, and sending, I explore an exemplary instance in the encounter between poetry and thought—when Heidegger met Hölderlin. Still, Heidegger's appropriation of poetry leaves a violent residue, a kind of critical warping that has remained largely uninterrogated. I turn to a moment in the unprecedented testimony of Hölderlin's late thought in which the poet names the modern experience of mourning. While Heidegger's later work appears to be characterized by a similar tonality of mourning, Hölderlin's thought of finitude is often more joyous and affirmative. I zero in on the figure of “dark-skinned women” in the poem “Andenken” to show how philosophy is tripped up by the permanent insurrection that poetry conducts.
The Ethical Uselessness of Grief: Randall Jarrell's “The Refugees”
Authors: Spargo R. Clifton
Published: November 2005

From among the varied American responses to the events we now call the Holocaust, the most notorious of which may well be the United States’ illiberal policy on refugees from 1938 to 1944, there emerged a canon of internationalist-minded literature that included Randall Jarrell's “The Refugees.” In his refugee poem, Jarrell experimented with the form of public elegy, interrogating poetic conventions of mourning in order to consider the ethical and political consequences of our statements of grief. With its extremely economic form, “The Refugees” offers a study of the lyric's investment in an economy of identity all too readily coinciding with nationalistic modes of belonging. As the poem positions itself as an interventionist yet fatalistic response to contemporary refugees, I argue, it helps us articulate a definition of ethics, which necessarily involves the negotiation of cultural boundaries and remains always a matter of eminently political concern.
Is dehydroepiandrosterone a hormone?
Authors: Labrie F , Luu-The V , Bélanger A , Lin S-X , Simard J , Pelletier G , Labrie C
Published: November 2005

Dehydroepiandrosterone (DHEA) is not a hormone but it is a very important prohormone secreted in large amounts by the adrenals in humans and other primates, but not in lower species. It is secreted in larger quantities than cortisol and is present in the blood at concentrations only second to cholesterol. All the enzymes required to transform DHEA into androgens and/or estrogens are expressed in a cell-specific manner in a large series of peripheral target tissues, thus permitting all androgen-sensitive and estrogen-sensitive tissues to make locally and control the intracellular levels of sex steroids according to local needs. This new field of endocrinology has been called intracrinology. In women, after menopause, all estrogens and almost all androgens are made locally in peripheral tissues from DHEA which indirectly exerts effects, among others, on bone formation, adiposity, muscle, insulin and glucose metabolism, skin, libido and well-being. In men, where the secretion of androgens by the testicles continues for life, the contribution of DHEA to androgens has been best evaluated in the prostate where about 50% of androgens are made locally from DHEA. Such knowledge has led to the development of combined androgen blockade (CAB), a treatment which adds a pure anti-androgen to medical (GnRH agonist) or surgical castration in order to block the access of the androgens made locally to the androgen receptor. In fact, CAB has been the first treatment demonstrated to prolong life in advanced prostate cancer while recent data indicate that it can permit long-term control and probably cure in at least 90% of cases of localized prostate cancer. The new field of intracrinology or local formation of sex steroids from DHEA in target tissues has permitted major advances in the treatment of the two most frequent cancers, namely breast and prostate cancer, while its potential use as a physiological HRT could well provide a physiological balance of androgens and estrogens, thus offering exciting possibilities for women’s health at menopause.
Interactions with p300 enhance transcriptional activation by the PDZ-domain coactivator Bridge-1
Authors: Lee Jee H , Volinic Jamie L , Banz Constanze , Yao Kwok-Ming , Thomas Melissa K
Published: November 2005

Transcriptional coactivators are essential mediators of signal amplification in the regulation of gene expression in response to hormones and extracellular signals. We previously identified Bridge-1 (PSMD9) as a PDZ-domain coregulator that augments insulin gene transcription via interactions with the basic helix-loop-helix transcription factors E12 and E47, and that increases transcriptional activation by the homeodomain transcription factor PDX-1. In these studies, we find that transcriptional activation by Bridge-1 can be regulated via interactions with the histone acetyltransferase and nuclear receptor coactivator p300. In transfection assays, transcriptional activation by Bridge-1 is increased by the inhibition of endogenous histone deacetylase activity with trichostatin A, indicating that the transcriptional activation function of Bridge-1 can be regulated by histone modifications. The exogenous expression of p300 enhances the transcriptional activation by Bridge-1 in a dose-dependent manner. In contrast, the sequestration of p300 by the overexpression of the adenoviral protein E1A, but not by an E1A mutant protein that is unable to interact with p300, suppresses the transcriptional activation by Bridge-1. We demonstrate that p300 and Bridge-1 proteins interact in immunopre-cipitation and glutathione-S-transferase (GST) pull-down assays. Bridge-1 interacts directly with multiple regions within p300 that encompass C/H1 or C/H2 cysteine- and histidine-rich protein interaction domains and the histone acetyltransferase domain. Deletion or point mutagenesis of the Bridge-1 PDZ domain substantially reduces transcriptional activation by Bridge-1 and interrupts interactions with p300. We propose that p300 interactions with Bridge-1 can augment the transcriptional activation of regulatory target genes by Bridge-1.
Distribution of Education and Population Health: An Ecological Analysis of New York City Neighborhoods
Authors: Galea Sandro , Ahern Jennifer
Published: November 2005

Objectives. We assessed the relationship between distribution of education and health indicators in a large urban area to determine if distribution of education may be a determinant of population health.

Methods. We studied the association between distribution of education, measured with the education Gini coefficient, and rates of 8 health indicators in 59 neighborhoods in New York City.

Results. In separate adjusted ecological models, neighborhoods with more poorly distributed education had better population health indicators that might plausibly be associated with short-term changes in the social environment (e.g., homicide and infant mortality rate); there was no association between education distribution and health indicators more likely to be associated with long-term accumulation of social and behavioral stressors (e.g., cardiovascular disease and chronic lung disease mortality rates). These findings were robust to measures of income and to adjustment for several potential confounders (e.g., gender and race/ethnicity).

Conclusions. The presence in a neighborhood of highly educated people may be salutary for all residents, independent of the potentially deleterious consequences of income maldistribution.
Dielectric Loss and Calibration of the Hydra Probe Soil Water Sensor
Authors: Seyfried M. S. , Grant L. E. , Du E. , Humes K.
Published: November 2005

Widespread interest in soil water content (θ, m3 m−3) information for both management and research has led to the development of a variety of soil water content sensors. In most cases, critical issues related to sensor calibration and accuracy have received little independent study. We investigated the performance of the Hydra Probe soil water sensor with the following objectives: (i) quantify the inter‐sensor variability, (ii) evaluate the applicability of data from two commonly used calibration methods, and (iii) develop and test two multi‐soil calibration equations, one general, “default” calibration equation and a second calibration that incorporates the effects of soil properties. The largest deviation in the real component of the relative dielectric permittivity εr′ determined with the Hydra Probe using 30 sensors in ethanol corresponded to a water content deviation of about 0.012 m3m−3, indicating that a single calibration could be generally applied. In layered (wet and dry) media, εr′ determined with the Hydra Probe was different from that in uniform media with the same water content. In uniform media, θ was a linear function of √εr′ We used this functional relationship to describe individual soil calibrations and the multi‐soil calibrations. Individual soil calibrations varied independently of clay content but were correlated with dielectric loss. When applied to the 19‐soil test data set, the general calibration outperformed manufacturer‐supplied calibrations. The average θ difference, evaluated between and , was 0.019 m3m−3 for the general equation and 0.013 m3m−3 for the loss‐corrected equation.
Directional leakage and parameter drift
Authors: Hovd M. , Bitmead R. R.
Published: November 2005

A new method for eliminating parameter drift in parameter estimation problems is proposed. Existing methods for eliminating parameter drift work either on a limited time horizon, restricts the parameter estimates to a range that has to be determined a priori, or introduces bias in the parameter estimates which will degrade steady state performance. The idea of the new method is to apply leakage only in the directions in parameter space in which the exciting signal is not informative. This avoids the problem of parameter bias associated with conventional leakage. Copyright © 2005 John Wiley & Sons, Ltd.
Efficient Synthesis of Lactate‐Containing Depsipeptides by the Mitsunobu Reaction of Lactates
Authors: Grab Tobias , Bräse Stefan
Published: November 2005

The Mitsunobu reaction has been used as an efficient tool for the synthesis of orthogonally‐protected and unprotected depsipeptides such as Boc/Fmoc‐L‐Lys(Alloc)‐D‐Ala‐D‐Lac‐OAllyl or L‐Lys‐ D‐Ala‐D‐Lac that are bacterial cell wall precursor analogues found in vancomycin‐resistant enterococci.
Synthesis of Schiff Base‐Ruthenium Complexes and Their Applications in Catalytic Processes
Authors: Drozdzak Renata , Allaert Bart , Ledoux Nele , Dragutan Ileana , Dragutan Valerian , Verpoort Francis
Published: November 2005

The synthesis of various Schiff base mononuclear and binuclear ruthenium complexes, whose additional ligands around the metal core have been selected from an array of motifs, is described. These types of ruthenium complexes, conveniently prepared from commonly available ruthenium sources, are rather stable, display good tolerance towards diverse organic functionalities and also to air and moisture. Remarkably, they exhibit a high activity and chemoselectivity in a variety of catalytic processes such as ring‐closing metathesis (RCM), Kharasch addition, alkyne dimerization, enol ester synthesis, ring‐opening metathesis polymerization (ROMP) and atom‐transfer radical polymerization (ATRP). This review covers both homogeneous and heterogeneous hybrid Schiff base‐ruthenium complexes.
A Highly Active and Reusable Heterogeneous Ruthenium Catalyst for Olefin Metathesis
Authors: Li Liang , Shi Jian‐lin
Published: November 2005

The synthesis and characterization of Ru complexes of the type [L2X2RuCHR] (L=PPh3, PCy3, N‐heterocyclic carbenes or their derivates; X=Cl) grafted on mesoporous SBA‐15 material are described. In this heterogeneous catalyst the Ru complexes are anchored in the pore channels of mesoporous silica material SBA‐15 to prevent the decomposition of the catalytic species. Compared with formal organic‐supported heterogeneous catalysts, this heterogeneous catalyst shows relatively high catalytic activity in olefin metathesis reactions and can be used several times without any decrease in catalytic activities.
Design of Ionic Phosphites for Catalytic Hydrocyanation Reaction of 3‐Pentenenitrile in Ionic Liquids†
Authors: Vallée Christophe , Chauvin Yves , Basset Jean‐Marie , Santini Catherine C. , Galland Jean‐Christophe
Published: November 2005

The synthesis and characterization of a novel class of ionic phosphites bearing either a single cationic group obtained by quaternization of aminophosphites or three cationic groups prepared by reaction of phosphorus trichloride with imidazolium phenols are reported. The catalytic hydrocyanation reaction of 3‐pentenenitrile (3PN) into adiponitrile has been performed in the presence of Ni(0) with ionic phosphite ligands, and a Lewis acid in biphasic ionic liquid/organic solvent system. The screening of several original cationic phosphites was performed and the experimental conditions were optimized for the tri‐cationic phosphite tris‐4‐[(2,3‐dimethylimidazol‐1‐yl)methyl]phenyl phosphite tris[bis(trifluoromethylsulfonyl)amide]. It is possible to obtain performance similar to molecular systems and the catalyst and the Lewis acid were immobilized in the ionic phase.
Optimization of Ring‐Closing Metathesis: Inert Gas Sparging and Microwave Irradiation
Authors: Nosse Bernd , Schall Andreas , Jeong Won Boo , Reiser Oliver
Published: November 2005

A systematic study of a ring‐closing metathesis towards a tetrasubstituted double bond as part of a seven‐membered ring in a 5.7.5‐tricyclic guaianolide system is described. By combining two techniques, namely sparging an inert gas through the solution together with dielectric heating via microwave irradiation a high‐yielding ring‐closing metathesis reaction in this particularly challenging case was achieved. The results obtained compare favorably with conventional heating conditions or with microwave irradiation in a closed system. The key aspects seem to be that rapid microwave irradiation diminishes catalyst decay by allowing the required high reaction temperature to be reached quickly and homogeneously and thereby providing enough energy for a successful metathesis reaction, while inert gas sparging is purging off evolving ethylene to shift the equilibrium to the product.
Geometric design of fluid segments in microreactors using dimensionless numbers
Authors: Aoki Nobuaki , Hasebe Shinji , Mae Kazuhiro
Published: November 2005

In microreactors, reactant fluids are split into many fluid segments and then fed into the reactors to shorten mixing time. Two dimensionless numbers are introduced to represent effects of geometric design factors of fluid segments, such as shapes and arrangements, on reactor performance, namely mixing rate and product yield and selectivity: the ratio of reaction rate to diffusion rate and the aspect ratio of the mean diffusion length in the two‐dimensional (2‐D) directions in the reactor cross section. Methods to determine these numbers are also proposed. To examine the validity of these numbers on estimating the reactor performance, we compare product yields between each pair of reactors having the different geometric design factors but the same dimensionless numbers using computational fluid dynamics simulations. The results show that these numbers serve as the indices for estimating the reactor performance. Using these numbers, design guidelines for geometry of fluid segments are also discussed. © 2005 American Institute of Chemical Engineers AIChE J, 2006
Arboreal bipedalism in wild chimpanzees: Implications for the evolution of hominid posture and locomotion
Authors: Stanford Craig B.
Published: November 2005

Field observations of bipedal posture and locomotion in wild chimpanzees (Pan troglodytes) can serve as key evidence for reconstructing the likely origins of bipedalism in the last prehominid human ancestor. This paper reports on a sample of bipedal bouts, recorded ad libitum, in wild chimpanzees in Bwindi Impenetrable National Park in southwestern Uganda. The Ruhija community of chimpanzees in Bwindi displays a high rate of bipedal posture. In 246.7 hr of observation from 2001–2003, 179 instances of bipedal posture lasting 5 sec or longer were recorded, for a rate of 0.73 bouts per observation hour. Bipedalism was observed only on arboreal substrates, and was almost all postural, and not locomotor. Bipedalism was part of a complex series of positional behaviors related to feeding, which included two‐legged standing, one‐legged standing with arm support, and other intermediate postures. Ninety‐six percent of bipedal bouts occurred in a foraging context, always as a chimpanzee reached to pluck fruit from tree limbs. Bipedalism was seen in both male and female adults, less frequently among juveniles, and rarely in infants. Both the frequency and duration of bipedal bouts showed a significant positive correlation with estimated substrate diameter. Neither fruit size nor nearest‐neighbor association patterns were significantly correlated with the occurrence of bipedalism. Bipedalism is seen frequently in the Bwindi chimpanzee community, in part because of the unusual observer conditions at Bwindi. Most observations of bipedalism were made when the animals were in treetops and the observer at eye‐level across narrow ravines. This suggests that wild chimpanzees may engage in bipedal behavior more often than is generally appreciated. Models of the likely evolutionary origins of bipedalism are considered in the light of Bwindi bipedalism data. Bipedalism among Bwindi chimpanzees suggests the origin of bipedal posture in hominids to be related to foraging advantages in fruit trees. It suggests important arboreal advantages in upright posture. The origin of postural bipedalism may have preceded and been causally disconnected from locomotor bipedalism. Am J Phys Anthropol, 2006. © 2005 Wiley‐Liss, Inc.
Search for autism loci by combined analysis of Autism Genetic Resource Exchange and Finnish families
Authors: Ylisaukko‐oja Tero , Alarcón Maricela , Cantor Rita M. , Auranen Mari , Vanhala Raija , Kempas Elli , von Wendt Lennart , Järvelä Irma , Geschwind Daniel H. , Peltonen Leena
Published: November 2005

Objective

Several genome‐wide screens have been performed in autism spectrum disorders resulting in the identification of numerous putative susceptibility loci. Analyses of pooled primary data should result in an increased sample size and the different study samples have a potential to strengthen the evidence for some earlier identified loci, reveal novel loci, and even to provide information of the general significance of the locus. The objective of this study was to search for potential susceptibility loci for autism, which are supported by two independent samples.

Methods

We performed a combined analysis of the primary genome scan data of the Autism Genetic Resource Exchange (AGRE) and Finnish autism samples to reveal susceptibility loci potentially shared by these study samples.

Results

In the initial combined data analysis, the best loci (p < 0.05) were observed at 1p12‐q25, 3p24‐26, 4q21‐31, 5p15‐q12, 6q14‐21, 7q33‐36, 8q22‐24, 17p12‐q21, and 19p13‐q13. The combined analysis of Finnish and AGRE families showed the most promising shared locus on 3p24‐26 with nonparametric logarithm of odds (NPL) score of 2.20 (p = 0.011). The combined data analysis did not provide increased linkage evidence for the earlier identified loci on 3q25‐27 or 17p12‐q21. However, the 17p12‐q21 locus remained promising also in the combined sample (NPLall =2.38, p = 0.0076).

Interpretation

Our study of 314 autism families highlights the importance of further analyses on 3p24‐26 locus involving comprehensive molecular genetic analyses of oxytocin receptor gene (OXTR), a positional and functional candidate gene for autism. Ann Neurol 2005
Katalytische asymmetrische Tandemumwandlungen mit einer konjugierten Addition als einleitendem Schritt
Authors: Guo Hong‐Chao , Ma Jun‐An
Published: November 2005

Effiziente Synthesemethoden für Verbindungen mit mehreren Stereozentren sind von entscheidender Bedeutung für Wissenschaft und Industrie. Katalytische asymmetrische Tandemumwandlungen, die leicht zugängliche Ausgangsstoffe in enantiomerenreine komplexere Produkte umwandeln, könnten diese Herausforderung meistern. Aktuelle Fortschritte auf diesem Gebiet bilden das Thema dieses Kurzaufsatzes: Die jüngsten Entwicklungen werden ebenso angesprochen wie Anwendungen von metallkatalysierten und organokatalytischen asymmetrischen Tandemumwandlungen, die durch eine konjugierte Addition ausgelöst werden.
Catalytic Asymmetric Tandem Transformations Triggered by Conjugate Additions
Authors: Guo Hong‐Chao , Ma Jun‐An
Published: November 2005

The development of efficient methods to access complex molecules with multistereogenic centers has been a substantial challenge in both academic research and industrial applications. One approach to this challenge is catalytic asymmetric tandem transformations, which allow a rapid increase in molecular complexity from readily available starting materials to produce enantiopure compounds. In recent years, considerable efforts have been directed towards the development of asymmetric tandem transformations. This Minireview highlights recent developments and the applications of metal‐catalyzed and organocatalytic asymmetric tandem transformations triggered by conjugate additions.
Three‐dimensional anatomy of the conduction system of the early embryonic rabbit heart
Authors: Rothenberg Florence , Efimov Igor R.
Published: November 2005

The complete embryonic cardiac conduction system is difficult to view in three dimensions, primarily because there has not been a marker of all segments of the normal system throughout all stages of development. Imaging of the conduction system components within the atria has been particularly controversial because different markers reveal different pathways that may or may not represent conduction system components. The conduction system of the adult and embryonic rabbit, however, can be labeled in its entirety with the neurofilament marker, NF‐160. The conduction system of rabbit embryos at several stages of development spanning cardiac septation was therefore investigated. Optical mapping of the electrical signature of the conduction system previously revealed a close correlation between the cardiac activation patterns and the anatomy as shown by serial sections. The 3D relationship between the components of the conduction system could only be inferred from the 2D sections. The sections were consequently reconstructed using a commercial software program (AutoQuant). This is the first demonstration of the three‐dimensional complete normal rabbit embryonic cardiac conduction system at several stages of development. © 2005 Wiley‐Liss, Inc.
A bibliometric model for journal discarding policy at academic libraries
Authors: Jiménez‐Contreras Evaristo , Moneda Mercedes De La , Osma Elvira Ruiz de , Bailón‐Moreno Rafael , Ruiz‐Baños Rosario
Published: November 2005

The authors propose a bibliometric model for discarding journal volumes at academic libraries, i.e., removal to offsite storage as part of the library's serials collection. The method is based on the volume as the unit of measurement and on user satisfaction with given titles. The discarding age, calculated for each volume, from the year of publication to the year of decision to discard, is dependent on citation half‐life, relative productivity, knowledge area, and residual utility (potential consultations). The model makes it possible to predict the approximate size of a collection when a stationary state is reached in which the inflow of journal volumes is equal to the outflow from discarding. The model is also able to determine the rate of growth of the holdings. This information can be used to optimize future use of available space and economic and maintenance resources; thus promoting efficient management of the collection.
Bacterial translocation studied in 927 patients over 13 years
Authors: MacFie J , Reddy B S , Gatt M , Jain P K , Sowdi R , Mitchell C J
Published: November 2005

Background

Bacterial translocation (BT) describes the passage of bacteria from the gastrointestinal tract to normally sterile tissues such as the mesenteric lymph nodes (MLNs) and other internal organs. The clinical and pathophysiological significance of BT remains controversial. This report describes results obtained over a 13-year period of study.

Methods

MLNs were obtained from 927 patients undergoing laparotomy. Nasogastric aspirates were obtained from 458 (49·4 per cent) of 927 patients for culture; pH was measured in 172 (37·6 per cent) of 458. Preoperative clinical variables were evaluated and factors that influenced BT were included in a multivariate logistic regression analysis.

Results

BT was identified in 130 (14·0 per cent) of 927 patients. Postoperative sepsis was more common in patients with BT (42·3 versus 19·9 per cent; P < 0·001). Independent preoperative variables associated with BT were emergency surgery (P = 0·001) and total parenteral nutrition (TPN) (P = 0·015). Gastric colonization was confirmed in 248 (54·1 per cent) of 458 patients, and was associated with both BT (P = 0·015) and postoperative sepsis (P = 0·029). A gastric pH of less than 4 was associated with a significant reduction in gastric colonization (53 versus 80 per cent; P < 0·001) and postoperative sepsis (46 versus 70·3 per cent; P = 0·018) but not BT.

Conclusion

BT is associated with postoperative sepsis. Emergency surgery and TPN are independently associated with an increased prevalence of BT.