bluuebunny/crossref_metadata_2025 huggingface dataset:
Occurrence of Cryptosporidium hominis in pigeons (Columba livia)
Authors: Abreu-Acosta Néstor , Foronda-Rodríguez Pilar , López Mercedes , Valladares Basilio
Published: January 2009

This study demonstrated the presence of Cryptosporidium hominis in pigeons for the first time. Previously, C. hominis had been cited only in another bird species, Branta canadiensis. The present findings suggest that pigeons may act as mechanical vectors for this protozoan.
Calydiscoides limae sp. nov. (Monogenea, Diplectanidae) from Pentapodus aureofasciatus (Perciformes, Nemipteridae) off New Caledonia
Authors: Justine Jean-Lou , Brena Pierpaolo
Published: January 2009

Calydiscoides limae sp. nov. is described from the nemipterid Pentapodus aureofasciatus Russell, 2001 caught along the barrier reef off New Caledonia, South Pacific. The new species is characterised by its male copulatory organ, with a distal blade and a lateral spur, and its female sclerotised organ, with a sphere and a thin tube. Its lamellodiscs always have 7 concentric lamellae, with the 3 internal lamellae complete and the 4 peripheral lamellae progressively less and less complete; measurements of the angles occupied by the lamellae in numerous specimens showed that the lamellodisc structure shows little variation among individuals.
A new species of Dichelyne (Nematoda, Cucullanidae) parasitizing sciaenid fishes from off the South American Atlantic coast
Authors: Timi Juan , Lanfranchi Ana , Tavares Luiz , Luque José
Published: January 2009

A new nematode species Dichelyne (Cucullanellus) sciaenidicola sp. nov. is described based on specimens collected from the Whitemouth croaker Micropogonias furnieri (Desmarest) and the Argentine croaker Umbrina canosai Berg, from coastal waters of Argentina and Brazil. These nematodes were firstly identified as D. (C.) elongatus (Törnquist, 1931), a commonly reported species from M. furnieri in South American Atlantic waters. However, other species of Dichelyne have so far been reported from this host in the same area, namely D. (C.) rodriguesi (Pinto, Fábio et Noronha, 1970), D. (C.) amaruincai (Freitas, Vicente et Ibañez, 1969) and D. (Dichelyne) micropogonii Pereira et Costa, 1996. A careful re-examination of these parasites, as well as of type specimens of all species reported from M. furnieri, revealed that these nematodes represented a new species. The new species is distinguished from most of its congeners by having papillae 5–7 and 9 forming a subventral line close to cloaca, this feature is shared with other 6 species [D. (C.) dichelyneformis (Szidat, 1950), D. (C.) fraseri (Baylis, 1929), D. (C.) abbreviatus (Rudolphi, 1819), D. (C.) adriaticus (Törnquist, 1931), D. (C.) minutus (Rudolphi, 1819) and D. (C.) mariajuliae Alarcos, Timi, Etchegoin et Sardella, 2006)], which are readily distinguished by their body size, spicules length, distribution patterns of other papillae and position of the excretory pore and deirids. Also, D. (C.) elongatus from Umbrina canariensis (Valenciennes) from West Africa is established as a new species Dichelyne (Cucullanellus) yvonnecampanae sp. nov.; D. (C.) amaruincai from Pacific waters is considered as a valid species, D. (D.) micropogonii is regarded as species inquirendae and D. (C.) rodriguesi is identified as Cucullanus sp.
Historical account of the two family-group names in use for the single accepted family comprising the “fish blood flukes”
Authors: Bullard Stephen , Jensen Kirsten , Overstreet Robin
Published: January 2009

The family-group name for the “fish blood flukes” is unstable, with both “Aporocotylidae Odhner, 1912” and “Sanguinicolidae von Graff, 1907” in use for the single family. Although “Sanguinicolidae von Graff, 1907” (or. Graff, 1907.) has been a widely-accepted family-group name for the fish blood flukes subsequent to Yamaguti’s 1954 and 1958 synoptical publications (“Systema Helminthum”), a critical examination of the relevant literature, much of it published in German during 1900 through 1926, reveals that “Aporocotylidae Odhner, 1912” is the earliest available family-group name for these flukes. The name Aporocotylidae, moreover, was in wide usage by alpha taxonomists before 1954 and by several authors between 1954 and the present time. We speculate that the recent long-standing uncertainty about the earliest available family-group name primarily stems from the (1) logistics of Ludwig von Graff’s tome published in 1904–1908, (2) bibliographic confusion between that work and another Graff work published in 1907 (both of which treat Sanguinicola but not Aporocotyle), (3) initial ambiguity regarding the phylogenetic relatedness of the first four aporocotylid species that were named, (4) lack of consensus on the status of Aporocotylidae and Sanguinicolidae and the genera included within them, and (5) misleading application of. Graff, 1907. to Sanguinicolidae by Poche in 1926, Fuhrmann in 1928, Yamaguti in 1954 and 1958, and subsequent review articles that treated fish blood flukes. Under the International Code of Zoological Nomenclature (ICZN, Article 8.3), “Sanguinicolidae” was not made available by Graff because he disclaimed the name in the same, and only, work wherein he used the name (ICZN, Article 8.3). Sanguinicolidae was first made available in 1926 by Poche, who referenced Graff’s 1907 work. Hence, “Poche, 1926” comprises the correct authority and date for that family-group name, not “von Graff, 1907” or “Graff, 1907”. Since we presently accept only a single family for all fish blood flukes and abide by the Principal of Priority (ICZN, Article 23), we herein regard Sanguinicolidae Poche, 1926 as a junior subjective synonym of Aporocotylidae Odhner, 1912.
Two new species of entobdelline skin parasites (Monogenea, Capsalidae) from the blotched fantail ray, Taeniura meyeni, in the Pacific Ocean, with comments on spermatophores and the male copulatory apparatus
Authors: Whittington Ian , Kearn Graham
Published: January 2009

We made a comparative anatomical study of entobdelline monogenean skin parasites from the blotched fantail ray, Taeniura meyeni (= T. melanospila) from public aquaria and fish-holding facilities distributed widely across the western Pacific Ocean. These facilities were located in Australia (Mooloolaba, southern Queensland; Cairns, northern Queensland), Taiwan and Japan. The capture localities of the aquarium fishes are unknown to us, with the exception of the individual fish from northern Queensland which came from Sudbury Reef, a local inshore reef. Entobdellines from southern Queensland differed morphologically from those from northern Queensland and Taiwan and the 2 new monogenean species are described and named Neoentobdella garneri sp. nov. and N. taiwanensis sp. nov., respectively. We determined that an entobdelline collected by Dyer and co-workers from a ray identified as T. melanospila (= T. meyeni) from an aquarium in Okinawa, Japan and identified by them as Entobdella squamula (Heath, 1902) Johnston, 1929 was misidentified and is tentatively assigned to N. taiwanensis sp. nov. The male copulatory organ of each new species resembles a penis, but evidence that these organs are eversible like a cirrus is presented. Caution is advised in deciding whether the male copulatory organs of capsalids may function as a penis or as a cirrus and we suggest that possession of a penis versus a cirrus may not necessarily indicate wide evolutionary divergence. In N. garneri, spermatophores consist of a sausage-shaped capsule and a long hollow stalk. A spermatophore received from a donor is anchored in the vagina by means of the stalk, with the capsule protruding outside the body.
Market Potential for International Rail-Based Intermodal Services in Europe
Authors: Nair Rahul , Miller-Hooks Elise D. , Mahmassani Hani S. , Arcot Vishnu Charan , Kuo April , Zhang Kuilin , Kozuki Aaron , Ludvigsen Johanna
Published: January 2009

This paper examines the market potential for international rail-based intermodal services along the REORIENT Corridor, which spans 11 countries from the Baltic (Scandinavia) to the Mediterranean (Greece) through the accession countries of the European Union. The main approach followed in this assessment is to conduct scenario analyses using a state-of-the-art intermodal freight network modeling capability, which allows the evaluation of various service supply strategies under varying operational and policy scenarios. New service design options, developed through a combination of market-based research and expert opinion, are evaluated in regard to the potential addressable market demand and the likelihood of successfully competing for that demand. The analyses provide realistic assessments of the potential competitiveness of rail in attracting freight demand resulting from (a) operational considerations that pertain to the proposed services and (b) implementation of interoperability directives and barrier-removing or barrier-reducing improvements in physical, operational, or managerial aspects and business practices of the rail system that are aimed toward achieving European Commission policy objectives. In addition, the analysis points to characteristics of the demand, which is most likely to shift toward rail, in regard to commodity types and geographic location. The key question the paper seeks to answer is under what operational and policy conditions can pan-European intermodal rail freight services be competitive? Results show that prerequisites for success are a combination of favorable rail policies and the intermodal operations’ high level of service.
Regional Repositioning of Empty Containers
Authors: Boile Maria , Theofanis Sotiris , Baveja Alok , Mittal Neha
Published: January 2009

Regional repositioning of empty containers involves empty container movement between regional importers, marine terminals, depots, and export customers. This chain movement generates unproductive empty vehicle miles in the region. The problem of empty vehicle miles becomes more prominent because empty container depots are located close to the port and customers are inland. Considering the double-digit increase in containerized trade volumes and the persistent trade imbalance that strain existing depot capacities in major import areas, this paper focuses on the optimal location of new container depots and the repositioning of empty containers in a region. It proposes a system of inland depots for empty containers (IDEC) in which new depots would be built closer to customer clusters. An IDEC system can minimize the total system costs (cost of opening new depots plus repositioning cost of empties) and provide additional required capacity. The paper presents a mathematical model of such a system and discusses its feasibility and effectiveness. The proposed system is evaluated for a region based on the New York–New Jersey port region. Results show that by building inland depots, empty vehicle miles traveled and total system cost of repositioning empties are reduced significantly. At the same time, capacity is added to the system, preventing a shortfall that would result from the increase in trade and the trade imbalance. The authors believe that an IDEC system has great potential in optimizing regional empty moves.
Service Time Variability at Blaine, Washington, Border Crossing and Impact on Regional Supply Chains
Authors: Goodchild Anne , Globerman Steve , Albrecht Susan
Published: January 2009

Variable service times at vehicle processing facilities (borders, weigh stations, landside marine port gates) cause transportation planning challenges for companies that regularly visit them. Companies must either build more time into their schedules than is necessary, and therefore underutilize their equipment, or risk missing delivery windows or exceeding hours of service regulations, actions that can result in fines, lost business opportunities, or other logistical costs. Border crossing times are examined at Blaine, Washington, between Whatcom County, Washington, and the Lower Mainland of British Columbia, Canada, to assess the variability in crossing times at this border crossing and the impact of this variability on regional supply chains. Variability data collected for bidirectional trade are presented. Directional, daily, hourly, and seasonal variations are examined, and interviews are conducted with regional carriers to better understand the current response to variability, the benefit of a reduction in variability, and how that is related to the goods moved or to other business operating characteristics. This paper describes the level of variability in border crossing times and carriers’ responses to this variability and shows that the primary strategy used, increasing buffer times, reduces carrier productivity. However, this cost is negligible because of the current nature of the industry.
Screening Process for Identifying Potential Truck-Only Toll Lanes in a Metropolitan Area
Authors: Chu Hsing-Chung , Meyer Michael D.
Published: January 2009

The growing number of trucks using urban freeways has caused transportation officials to seek innovative strategies for providing truck mobility in ways that do not add to freeway congestion. One strategy being considered is truck-only toll (TOT) lanes. This paper presents a methodology for identifying candidate TOT lanes in urban freeway corridors. The criteria used to select candidate freeway segments include freeway level of service, truck volumes, truck percentage of total freeway flow, crashes, and trucker willingness to pay. These criteria are applied to the Atlanta, Georgia, freeway system to illustrate the application of the screening approach. The paper also discusses the process for determining different toll rates for maximizing revenue generation, providing an acceptable level of service, achieving a TOT lane utilization of greater than 50%, and minimizing truck diversion to local roads.
Analysis and Cost-Recovery Optimization Methodology for a Fixed-Class Truck Tolling Structure
Authors: Conway Alison , Walton C. Michael
Published: January 2009

The purpose of this study is to develop a methodology for examining existing class-based toll structures for “fairness” between different commercial truck classes and for optimizing toll rates within each class to fully recover the total cost of pavement consumed by trucks. A theoretical methodology for setting toll rates to optimize cost recovery within a given class and achieve fairness between classes is defined. Methods for analyzing existing toll rate structures using weigh-in-motion (WIM) data in the absence of full vehicle identification information are also described. A case study of Texas State Highway 130 demonstrates the usefulness of WIM data for analysis of a toll classification system based on number of axles.
Stochastic Dominance Approach to Evaluate Optimism Bias in Truck Toll Forecasts
Authors: Gupta Rajorshi Sen , Vadali Sharada R.
Published: January 2009

Optimism bias is a consistent feature associated with truck toll forecasts, à la Standard & Poor's and the NCHRP synthesis reports. Given the persistent problem, two major sources of this bias are explored. In particular, the ignorance of operating cost as a demand-side factor and lack of attention to user heterogeneity are found to contribute to this bias. To address it, stochastic dominance analysis is used to assess the risk associated with toll revenue forecasts. For a hypothetical corridor, it is shown that ignorance of operating cost savings can lead to upward bias in the threshold value of time distribution. Furthermore, dominance analysis demonstrates that there is greater risk associated with the revenue forecast when demand heterogeneity is factored in. The approach presented is general and can be applied to all toll forecasts and is not restricted to trucks.
Benefits and Costs of Four Approaches to Improving Rollover Stability of Cargo Tank Motor Vehicles
Authors: Pape Douglas B. , McMillan Nancy , Greenberg Art , Mayfield Heather , Chitwood J. Caleb , Winkler Christopher B. , Blower Daniel , Gordon Timothy , Barnes Michelle , Brock John , Harback Kate
Published: January 2009

Four broad approaches to decreasing the number of cargo tank rollovers were evaluated: driver training, electronic stability aids, improvements in design of the vehicle itself, and highway design. A study of rollover crash statistics confirmed many expectations, but a few of the factors were not as strong as might have been expected. The portion of rollovers that occur on freeways is 15% to 20%. A driver error of one kind or another (e.g., decision or performance error) figures in about three-fourths of cargo tank rollovers. Inattention and distraction account for about 15%. Evasive maneuvers were a factor in 5% to 10% of rollovers. Drivers must be trained to appreciate the diverse causes for rollovers and to anticipate the situations that lead to them. Adherence to viable work and rest schedules is crucial. Electronic stability aids automatically slow the truck when it rounds a curve too fast. They can be remarkably effective in preventing this scenario. However, crash statistics and anecdotal accounts consistently show many other factors that can lead to rollovers. Significant reductions in rollover rates can be achieved with modest changes in vehicle stability. Cargo tank trailers of improved stability are currently available for some cargoes. When mountainous terrain or other factors dictate highway designs that can contribute to rollovers, drivers need to be made aware through signage or dispatch instructions. A comprehensive benefit–cost analysis, conducted from a societal point of view during a 20-year window, projected that the improvements will be cost beneficial.
Chemical Composition of Essential Oilsof Thymus and Mentha Speciesand Their Antifungal Activities
Authors: Soković Marina D. , Vukojević Jelena , Marin Petar D. , Brkić Dejan  D. , Vajs Vlatka , Van Griensven Leo  J. L. D.
Published: January 2009

The potential antifungal effects of Thymus vulgaris L., Thymus tosevii L., Mentha spicata L., and Mentha piperita L. (Labiatae) essential oils and their components against 17 micromycetal food poisoning, plant, animal and human pathogens are presented. The essential oils were obtained by hydrodestillation of dried plant material. Their composition was determined by GC-MS. Identification of individual constituents was made by comparison with analytical standards, and by computer matching mass spectral data with those of the Wiley/NBS Library of Mass Spectra. MIC’s and MFC’s of the oils and their components were determined by dilution assays. Thymol (48.9%) and p-cymene (19.0%) were the main components of T. vulgaris, while carvacrol (12.8%), a-terpinyl acetate (12.3%), cis-myrtanol (11.2%) and thymol (10.4%) were dominant in T. tosevii. Both Thymus species showed very strong antifungal activities. In M. piperita oil menthol (37.4%), menthyl acetate (17.4%) and menthone (12.7%) were the main components, whereas those of M. spicata oil were carvone (69.5%) and menthone (21.9%). Mentha sp. showed strong antifungal activities, however lower than Thymus sp. The commercial fungicide, bifonazole, used as a control, had much lower antifungal activity than the oils and components investigated. It is concluded that essential oils of Thymus and Mentha species possess great antifungal potential and could be used as natural preservatives and fungicides.
Molecular Docking Studies and Anti-Tyrosinase Activity of Thai Mango Seed Kernel Extract
Authors: Nithitanakool Saruth , Pithayanukul Pimolpan , Bavovada Rapepol , Saparpakorn Patchreenart
Published: January 2009

The alcoholic extract from seed kernels of Thai mango (Mangifera indica L. cv. ‘Fahlun’) (Anacardiaceae) and its major phenolic principle (pentagalloylglucopyranose) exhibited potent, dose-dependent inhibitory effects on tyrosinase with respect to L-DOPA. Molecular docking studies revealed that the binding orientations of the phenolic principles were in the tyrosinase binding pocket and their orientations were located in the hydrophobic binding pocket surrounding the binuclear copper active site. The results indicated a possible mechanism for their anti-tyrosinase activity which may involve an ability to chelate the copper atoms which are required for the catalytic activity of tyrosinase.
MAPSAR Image Simulation Based on L-band Polarimetric Data from the SAR-R99B Airborne Sensor (SIVAM System)
Authors: Mura José Claudio , Paradella Waldir Renato , Dutra Luciano Vieira , Dos Santos João Roberto , Rudorff Bernardo Friedrich Theodor , De Miranda Fernando Pellon , Da Silva Mario Marcos Quintino , Da Silva Wagner Fernando
Published: January 2009

This paper describes the methodology applied to generate simulated multipolarized L-band SAR images of the MAPSAR (Multi-Application Purpose SAR) satellite from the airborne SAR R99B sensor (SIVAM System). MAPSAR is a feasibility study conducted by INPE (National Institute for Space Research) and DLR (German Aerospace Center) targeting a satellite L-band SAR innovative mission for assessment, management and monitoring of natural resources. Examples of simulated products and their applications are briefly discussed.
Remote Sensing Data with the Conditional Latin Hypercube Sampling and Geostatistical Approach to Delineate Landscape Changes Induced by Large Chronological Physical Disturbances
Authors: Lin Yu-Pin , Chu Hone-Jay , Wang Cheng-Long , Yu Hsiao-Hsuan , Wang Yung-Chieh
Published: January 2009

This study applies variogram analyses of normalized difference vegetation index (NDVI) images derived from SPOT HRV images obtained before and after the ChiChi earthquake in the Chenyulan watershed, Taiwan, as well as images after four large typhoons, to delineate the spatial patterns, spatial structures and spatial variability of landscapes caused by these large disturbances. The conditional Latin hypercube sampling approach was applied to select samples from multiple NDVI images. Kriging and sequential Gaussian simulation with sufficient samples were then used to generate maps of NDVI images. The variography of NDVI image results demonstrate that spatial patterns of disturbed landscapes were successfully delineated by variogram analysis in study areas. The high-magnitude Chi-Chi earthquake created spatial landscape variations in the study area. After the earthquake, the cumulative impacts of typhoons on landscape patterns depended on the magnitudes and paths of typhoons, but were not always evident in the spatiotemporal variability of landscapes in the study area. The statistics and spatial structures of multiple NDVI images were captured by 3,000 samples from 62,500 grids in the NDVI images. Kriging and sequential Gaussian simulation with the 3,000 samples effectively reproduced spatial patterns of NDVI images. However, the proposed approach, which integrates the conditional Latin hypercube sampling approach, variogram, kriging and sequential Gaussian simulation in remotely sensed images, efficiently monitors, samples and maps the effects of large chronological disturbances on spatial characteristics of landscape changes including spatial variability and heterogeneity.
Multifrequency Tympanometry in Neonatal Intensive Care Unit and Well Babies
Authors: Shahnaz Navid , Miranda Terence , Polka Linda
Published: January 2009

Background: Conventional low probe tone frequency tympanometry has not been successful in identifying middle ear effusion in newborn infants due to differences in the physiological properties of the middle ear in newborn infants and adults. With a rapid increase in newborn hearing
screening programs, there is a need for a reliable test of middle ear function for the infant population. In recent years, new evidence has shown that tympanometry performed at higher probe tone frequencies may be more sensitive to middle ear disease than conventional low probe tone frequency
in newborn infants. Purpose: The main goal of this study was to explore the characteristics of the normal middle ear in the NICU (neonatal intensive care unit) and well babies using conventional and multifrequency tympanometry (MFT). It was also within the scope of this study to compare
conventional and MFT patterns in NICU and well babies to already established patterns in adults to identify ways to improve hearing assessment in newborns and young infants. Methods: Three experiments were conducted using standard and MFT involving healthy babies and NICU babies. NICU
babies (n  =  33), healthy three-week-old babies (n  =  16), and neonates on high-priority hearing registry (HPHR) (n  =  42) were tested. Thirty-two ears of 16 healthy Caucasian adults (compared to well-babies) and 47 ears of 26 healthy Caucasian adults (compared
to NICU babies) were also included in this study. Results: The distribution of the Vanhuyse patterns as well as variation of admittance phase and peak compensated susceptance and conductance at different probe tone frequencies was also explored. In general, in both well babies and NICU
babies, 226 Hz tympanograms are typically multipeaked in ears that passed or referred on transient otoacoustic emission (TEOAE), limiting the specificity and sensitivity of this measure for differentiating normal and abnormal middle ear conditions. Tympanograms obtained at 1 kHz are potentially
more sensitive and specific to presumably abnormal and normal middle ear conditions. Tympanometry at 1 kHz is also a good predictor of presence or absence of TEOAE.
Hearing Aids for Ménière's Syndrome: Implications of Hearing Fluctuation
Authors: McNeill Celene , McMahon Catherine M. , Newall Philip , Kalantzis Mary
Published: January 2009

Background: Hearing fluctuation imposes the biggest challenge in the fitting of hearing aids for patients with Ménière's syndrome. Purpose: This study shows that the problem maybe be overcome by allowing the patients to test their own hearing and to program
their own hearing aids to adjust for hearing fluctuation. Research Design and Study Sample: A group of 40 participants diagnosed with Ménière's syndrome were fitted with Widex Senso Diva hearing aids and were provided with a portable Senso Programmer 3 (SP3) that allowed
them to measure their own hearing thresholds at up to 14 different frequencies and to program their own devices. Intervention: The participants were instructed to test their hearing three times a day for 8 weeks and to program their hearing aids according to the measured thresholds.
Data Collection and Analysis: All participants recorded some degree of hearing fluctuation during the 8-week trial. Results and Conclusions: Among participants, 70 percent continued to program their hearing aids on a regular basis and reported great satisfaction with amplification
because they are now able to adjust their own devices when their hearing fluctuates.
A Daily Alternating Method for Comparing Different Signal-Processing Strategies in Hearing Aids and in Cochlear Implants
Authors: Tyler Richard S. , Witt Shelley A. , Dunn Camille C. , Perreau Ann E.
Published: January 2009

Background: Although we always want to select the best signal-processing strategy for our hearing-aid and cochlear-implant patients, no efficient and valid procedure is available. Comparisons in the office are without listening experience, and short-term take-home trials are
likely influenced by the order of strategies tried. Purpose: The purpose of this study was to evaluate a new procedure for comparing signal-processing strategies whereby patients listen with one strategy one day and another strategy the next day. They continue this daily comparison
for several weeks. We determined (1) if differences existed between strategies without prior listening experience and (2) if performance differences (or lack there of) obtained at the first listening experience are consistent with performance after two to three months of alternating between
strategies on a daily basis (equal listening experience). Research Design: Eight subjects were tested pretrial with a vowel, sentence, and spondee recognition test, a localization task, and a quality rating test. They were required to listen to one of two different signal processing
strategies alternating between strategies on a daily basis. After one to three months of listening, subjects returned for follow-up testing. Additionally, subjects were asked to make daily ratings and comments in a diary. Results: Pre-trial (no previous listening experience), a clear
trend favoring one strategy was observed in four subjects. Four other subjects showed no clear advantage. Post-trial (after alternating daily between strategies), of the four subjects who showed a clear advantage for one signal processing strategy, only one subject showed that same advantage.
One subject ended up with an advantage for the other strategy. Post-trial, of the four subjects who showed no advantage for a particular signal processing strategy, three did show an advantage for one strategy over the other. Conclusion: Patients are willing to alternate between signal
processing strategies on a daily basis for up to three months in an attempt to determine their optimal strategy. Although some patients showed superior performance with initial fittings (and some did not), the results of pre-trial comparison did not always persist after having equal listening
experience. We recommend this daily alternating listening technique when there is interest in determining optimal performance among different signal processing strategies when fitting hearing aids or cochlear implants.
Revisión del proceso siderúrgico de colada continua mediante solidificación rápida. Sistema de dos cilindros de colada conformación
Authors: Ibarrondo I.
Published: January 2009

A la vista de la evolución del mercado siderúrgico mundial, se hace evidente que las instalaciones siderúrgicas deberán desarrollar nuevos procesos siderúrgicos, capaces de producir productos de alta calidad y valor añadido, con menores inversiones de capital, ahorro energético y disminución de emisiones contaminantes. Dentro de este contexto, la tecnología de colada continua por solidificación rápida mediante dos cilindros, se presenta como una de las más interesantes a investigar. En el presente trabajo se realiza una descripción general del proceso de colada continua mediante solidificación rápida así como de sus diferentes etapas; alimentación del sistema y colada, proceso solidificación, etapa de laminación en caliente etc. Se describe, asimismo, mediante modelos matemáticos y físicos, la influencia que, sobre la microestructura, textura, calidad superficial y propiedades mecánicas de los materiales, ejercen los parámetros del proceso de fabricación, con especial mención a la influencia de la rugosidad de los cilindros de colada conformación en el proceso de solidificación. La fabricación de aceros al carbono, inoxidables y chapa magnética puede alcanzarse con inversiones específicas de capital, consumo energético y emisión de agentes contaminantes muy inferiores a los procesos convencionales. Teniendo en consideración todo esto es posible afirmar que este nuevo proceso siderúrgico está llamado a desempeñar un papel importante dentro de los procesos siderúrgicos del siglo XXI.
Efecto del boro en la sinterización de un acero inoxidable ferrítico
Authors: Cabral-Miramontes J. A. , Barceinas-Sánchez J. D.O. , Vélez-Jacobo L. , Martínez-Villafañe A. , Chacón-Nava J. G.
Published: January 2009

En este trabajo se analiza el efecto del boro sobre la densidad del acero inoxidable ferrítico 409Nb en el proceso de sinterización. La finalidad de adicionar boro es promover la formación de una fase líquida durante la sinterización, a una temperatura por debajo de 1.200 °C. Las adiciones de boro variaron entre 0,0 y 1,5 % en peso. Las muestras se compactaron a 700 MPa y las sinterizaciones se realizaron a 1.075 y 1.150 ºC, durante 60 min en una atmósfera de hidrógeno, calentando a una velocidad de 20 ºC/min. La densidad se determinó por el método de Arquímedes y las muestras se analizaron en el microscopio electrónico de barrido. Este trabajo muestra la dependencia de la densidad del acero y morfología de la microestructura, en función del contenido de boro y la temperatura de sinterización.
Ensayos de rozamiento plano sobre aceros inoxidables austeníticos con diferente acabado superficial. Determinación de las condiciones de adhesión en el rozamiento
Authors: Coello J. , Miguel V. , Ferrer C. , Calatayud A. , Martínez A.
Published: January 2009

El objetivo de este trabajo es determinar el comportamiento tribológico de los aceros inoxidables austeníticos 304 con acabado brillante BA (ASTM A 240), 304 DDQ y 316 con acabado mate 2B, en sistemas de contacto plano, con el fin de simular el rozamiento en la zona del flanco en los procesos de embutición de acero inoxidable. Para ello, se ha estudiado la influencia del acabado superficial del acero, la velocidad de deslizamiento y la presión normal sobre el coeficiente de rozamiento, utilizando un ensayo de fricción con matrices planas. Los ensayos se han realizado con aceite mineral de 200 cst, grasa de bisulfuro de molibdeno y en seco. En presencia de aceite, se ha establecido una correlación de m con la velocidad de deslizamiento y la presión de contacto con comportamiento fuertemente adhesivo en las condiciones de lubricación límite consideradas. Los resultados obtenidos muestran que la grasa de bisulfuro de molibdeno disminuye en un 50 % los valores del coeficiente de rozamiento. Se ha constatado una menor tendencia al gripado para la calidad 316 caracterizada por una mayor dureza superficial. El rozamiento experimentado bajo las condiciones más severas va acompañado de un relevante efecto plowing con un endurecimiento superficial importante del acero.
Proceso de materiales ultrafino-granulosos usando la deformación plástica severa: potencial para alcanzar características excepcionales
Authors: Langdon T. G.
Published: January 2009

El procesado de metales policristalinos a través de deformación plástica severa está atrayendo mucha atención, debido al potencial para alcanzar un importante afino de grano a niveles submicrométricos o nanométricos. Esta publicación revisa los principios de este tipo de procesado haciendo hincapié en dos técnicas diferentes: prensado en canal angular y torsión bajo alta presión. Mediante estos procesos, se pueden alcanzar propiedades excepcionales incluyendo alta resistencia a temperatura ambiente y una capacidad de conformación superplástica rápida a elevadas temperaturas. Se presentan algunos ejemplos demostrando el uso potencial de este tipo de procesado.
Characterisation of environmental forcing on Zostera marina L. plastochrone interval dynamics in the Punta Banda Estuary, B.C. Mexico: an empirical modelling approach
Authors: Solana-Arellano Elena , Echavarría-Heras Hector , Leal-Ramírez Cecilia
Published: January 2009

This paper presents a characterisation of the most significant environmental influences on plastochrone interval variation for Zostera marina L. in Punta Banda estuary B.C. Mexico. Data were collected from April 1998 to December 2001. Using correlation and principal component analysis, we found that the combination of sea surface temperature, light radiation and dissolved nutrients explains the observed variability consistently. Sea surface temperature was found to be the dominant environmental influence (r=0.89, p
Diversity and distribution of the Gastropoda Opisthobranchia from the Atlantic Ocean: A global biogeographic approach
Authors: García Francisco J. , Bertsch Hans
Published: January 2009

A zoogeographic study of the Opisthobranchia (Mollusca, Gastropoda) from the Atlantic Ocean was carried out. Data on Opisthobranch occurrence were collated from literature records and databases. An estimated 1066 species were considered for this study, which belonged to the orders Cephalaspidea, Anaspidea, Sacoglossa, Notaspidea and Nudibranchia. Biogeographical patterns were analysed using cluster analysis (TWINSPAN) and ordination MDS (non-metric multidimensional scaling program). The richness of opisthobranchs increases from polar to tropical regions along Atlantic shores. The cluster analysis showed that there is a latitudinal and longitudinal separation of the biogeographical areas. The amphiatlantic species can be separated into four groups according to their distribution: G1.1.- the geographic range of species is limited to cold water on both sides of the Atlantic; G1.2.- species with geographic ranges limited to the western Arctic and Boreal regions, with a wide distribution in the eastern Atlantic, from the eastern Arctic or the eastern Boreal region to the Lusitanian and Mediterranean provinces; G2.1.- species with geographic ranges limited to the Caribbean and Mauritanian-Senegalese areas; G2.2.- species with a wide geographical distribution along both Atlantic shores.
Space utilisation patterns of bryozoans on the Patagonian scallop Psychrochlamys patagonica
Authors: López Gappa Juan , Landoni Néstor A.
Published: January 2009

We studied the bryozoan assemblage encrusting valves of the Patagonian scallop, Psychrochlamys patagonica, in 4 beds distributed along the continental shelf off Argentina to analyse (a) the distribution pattern of bryozoan colonies in different zones of the valves, (b) the influence of interspecific competition on assemblage composition, (c) whether encrusting species display different space utilisation strategies, and (d) whether bryozoan species richness and number of colonies vary in relation to host size. The assemblage was composed of 22 taxa and was dominated by Arachnopusia monoceros and Osthimosia eatonensis, which were at least one order of magnitude more abundant than any other species. Multivariate analyses based on coverage data of multiserial bryozoans separated the beds according to species richness rather than to geographic proximity and showed significant differences in assemblage structure between upper (left) and lower (right) valves and among beds. Competitive interactions occurred almost exclusively on lower valves, and more frequently in peripheral zones than in central zones of these valves. Correlations between valve area and number of bryozoan colonies, coverage and species richness were low but significant. Bryozoans were significantly more frequent, larger, and taxonomically diverse on lower valves than on upper valves. The uniserial colonies of Neothoa cf. chiloensis, the weakest bryozoan competitor, were as frequent in central zones as they were in peripheral zones, and usually spread out along channels on the scallop surface. This fugitive species was partially covered by multiserial colonies, but managed to persist even in peripheral areas of the lower valves.
Captive cotton‐top tamarins' (Saguinus oedipus oedipus) use of landmarks to localize hidden food items
Authors: Dolins Francine L.
Published: January 2009

Seventeen captive cotton‐top tamarins (Saguinus oedipus oedipus) were individually tested on their use of spatial relationships between landmarks to locate multiple hidden food items. In two experiments, the tamarins were presented with a spatial‐foraging task in which positions of hidden food rewards were fixed in relation to an array of visual cues. In Experiment 1, the cues+hidden food configuration was rotated 90° and the tamarins were successful in locating the food items significantly above chance levels (P<0.01). In Experiment 2 the cues+hidden food configuration was translated (up, down or sideways) from the previously learned configuration, and the monkeys successfully localized the hidden food items (P<0.001). Results indicate that the tamarins relied on the spatial relationship between the multiple landmarks to locate hidden food items rather than on an associative or beacon strategy. The results of these experiments support the contention that when contextually appropriate these captive New World monkeys have the capacity to rely on the spatial relationship or positions of several cues as an array to localize points in their environment. Am. J. Primatol. 71:316–323, 2009. © 2009 Wiley‐Liss, Inc.
Proton‐Detected Solid‐State NMR Spectroscopy of Natural‐Abundance Peptide and Protein Pharmaceuticals
Authors: Zhou Donghua H. , Shah Gautam , Mullen Charles , Sandoz Dennis , Rienstra Chad M.
Published: January 2009

Keine Anreicherung nötig: Eine empfindliche NMR‐Spektroskopiemethode wurde entwickelt, die gut aufgelöste 2D‐Spektren (15N‐1H und 13C‐1H) von großen Molekülen (wie Biopharmazeutika) liefert, ohne dass eine Isotopenanreicherung erforderlich ist. Diese Methode gab Einblicke in die Strukturen zweier lyophilisierter Aprotininproben sowie dreier Insulinproben in lyophilisierter, mikrokristalliner Suspension (rot; siehe Bild) und Fibrillenformen (grün).

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Fortschritte in der Chemie und Biologie natürlicher Antibiotika
Authors: Nicolaou K. C. , Chen Jason S. , Edmonds David J. , Estrada Anthony A.
Published: January 2009

Seit der bahnbrechenden Entdeckung von Penicillin wurde die Vielfalt natürlich vorkommender Moleküle ausgiebig hinsichtlich ihrer Eignung als Medikamente sowie zum Auffinden neuer Leitstrukturen beim Wirkstoffdesign untersucht. Die Suche nach Wirkstoffen, mit denen Infektionskrankheiten bekämpft werden können, war dabei von besonderem Interesse und verlief sehr erfolgreich. Die Erforschung der Antibiotika weist eindrucksvolle Entdeckungen und Geschichten über die Entwicklung von Wirkstoffen auf, von denen die große Mehrheit ihren Ursprung in Naturstoffen hat. Die Chemie und besonders die chemische Synthese haben eine bedeutende Rolle dabei gespielt, natürlich vorkommende Antibiotika und deren Derivate für die medizinische Anwendung bereitzustellen, und zweifellos werden diese Disziplinen auch künftig Schlüsseltechnologien sein. In dieser Übersicht stellen wir einige der bedeutendsten neueren Entwicklungen und Fortschritte in der Chemie, Biologie und Medizin natürlich vorkommender Antibiotika vor, wobei die Totalsynthese, das Design von Analoga und die biologische Bewertung von Molekülen mit neuartigen Wirkmechanismen im Vordergrund stehen.
Oxidase‐Like Activity of Polymer‐Coated Cerium Oxide Nanoparticles
Authors: Asati Atul , Santra Santimukul , Kaittanis Charalambos , Nath Sudip , Perez J. Manuel
Published: January 2009

Anorganisches Enzym? Ceroxidnanopartikel zeigen einzigartige Oxidaseaktivität bei niedrigen pH‐Werten. Diese Redoxkatalysatoren können in Immunassays (ELISA) verwendet werden, wenn sie mit geeigneten Liganden modifiziert sind (siehe Bild; hellblau, gelb: Nanopartikel mit Liganden). Diese Modifizierung ermöglicht sowohl die Bindung als auch die Detektion durch katalytische Oxidation empfindlicher kolorimetrischer Farbstoffe (z. B. TMB).

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Oxidase‐Like Activity of Polymer‐Coated Cerium Oxide Nanoparticles
Authors: Asati Atul , Santra Santimukul , Kaittanis Charalambos , Nath Sudip , Perez J. Manuel
Published: January 2009

Inorganic enzyme? Ceria nanoparticles exhibit unique oxidase‐like activity at acidic pH values. These redox catalysts can be used in immunoassays (ELISA) when modified with targeting ligands (see picture; light blue and yellow structures are nanoparticles with attached ligands). This modification allows both for binding and for detection by the catalytic oxidation of sensitive colorimetric dyes (e.g. TMB).

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Hydrogenation of N‐Acylcarbamates and N‐Acylsulfonamides Catalyzed by a Bifunctional [Cp*Ru(PN)] Complex
Authors: Ito Masato , Koo Lee Wei , Himizu Akio , Kobayashi Chika , Sakaguchi Ayaka , Ikariya Takao
Published: January 2009

Awakening of the Cp one: The bifunctional complex 1 facilitates the interaction with substrates bearing less electrophilic carbon atoms than ketones, epoxides, and imides. The title reaction was applicable to the reduction of Evans' asymmetric alkylation products to the chiral alcohols along with good recovery of the chiral oxazolidinone auxiliary. EWG=electron‐withdrawing group.

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Gas‐Phase versus Liquid‐Phase Structures by Electrospray Ionization Mass Spectrometry
Authors: Tian Zhixin , Kass Steven R.
Published: January 2009

Preferred protonation: Does electrospray ionization mass spectrometry produce gas‐phase or liquid‐phase structures? The preferred protonation site in p‐aminobenzoic acid depends upon the medium, and the structure of its conjugate acid varies with the solvent used during spraying.

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National and international dimensions of the Triple Helix in Japan: University–industry–government versus international coauthorship relations
Authors: Leydesdorff Loet , Sun Yuan
Published: January 2009

International co‐authorship relations and university–industry–government (Triple Helix) relations have hitherto been studied separately. Using Japanese publication data for the 1981–2004 period, we were able to study both kinds of relations in a single design. In the Japanese file, 1,277,030 articles with at least one Japanese address were attributed to the three sectors, and we know additionally whether these papers were coauthored internationally. Using the mutual information in three and four dimensions, respectively, we show that the Japanese Triple‐Helix system has been continuously eroded at the national level. However, since the mid‐1990s, international coauthorship relations have contributed to a reduction of the uncertainty at the national level. In other words, the national publication system of Japan has developed a capacity to retain surplus value generated internationally. In a final section, we compare these results with an analysis based on similar data for Canada. A relative uncoupling of national university–industry–government relations because of international collaborations is indicated in both countries.
Nano‐Supramolecular Assemblies Constructed from Water‐Soluble Bis(calix[5]arenes) with Porphyrins and Their Photoinduced Electron Transfer Properties
Authors: Guo Dong‐Sheng , Chen Kun , Zhang Hong‐Qing , Liu Yu
Published: January 2009

What a PET!Two well‐defined nanoarchitectures with 2D netlike and 1D linear topological structures are constructed by bis(p‐sulfonatocalix[5]arenes) and cationic porphyrins, respectively, in which an unambiguous PET process is observed. As a result, the supramolecular aggregates possess, in principle, benign photoelectric properties with the transport of an electron between the building blocks in the nanoscale region.

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Possessing 2D netlike and 1D linear morphologies, two nano‐supramolecular architecturesA1andA2are constructed by tetracationic porphyrin (G1) and dicationic porphyrin (G2), respectively, upon complexation with the novel water‐soluble bis(p‐sulfonatocalix[5]arenes) bridged at the lower rim (H2). Corresponding to the molecular design, the aggregation morphologies are well manipulated by the inherent binding sites of the building blocks through host–guest interactions as well as charge interactions. In comparison to the simplep‐sulfonatocalix[5]areneH1which can only form particle‐type complexesC1andC2with porphyrin guests,H2provides excellent pre‐organized structure to construct highly complex nano‐supramolecular assemblies. The exhibited electron‐transfer process of the supramolecular systems is further investigated by steady‐state and time‐resolved fluorescence spectroscopy, electrochemical measurements, and transient absorption spectroscopy. The results obtained show that calixarenes are also effective electron donors in PET besides acting as significant building blocks, which gives them many advantages in constructing well‐ordered nanomaterials with the capability of electron and energy transport.