bluuebunny/crossref_metadata_2025 huggingface dataset:
Cadmium toxicity causes oxidative stress and induces response of the antioxidant system in cucumber seedlings
Authors: Gonçalves Jamile F. , Becker Alexssandro G. , Cargnelutti Denise , Tabaldi Luciane A. , Pereira Luciane B. , Battisti Vanessa , Spanevello Rosélia M. , Morsch Vera M. , Nicoloso Fernando T. , Schetinger Maria R.C.
Published: January 2008

In this study, the effects of cadmium (Cd) on lipid peroxidation, electrolyte leakage, protein oxidation, ascorbate peroxidase (APX; E.C. 1.11.1.11), catalase (CAT; E.C. 1.11.1.6) and superoxide dismutase (SOD; E.C. 1.15.1.1) activities, and ascorbic acid, non-protein thiol groups and total soluble protein contents in cucumber seedlings (Cucumis sativus L.) were investigated. Seedlings were grown in vitro in an agar-solidified substrate containing four Cd levels as CdCl2 (0, 100, 400, and 1000 µmol L-1) for 10 d. The lowest Cd level decreased the malondialdehyde concentration. Electrolyte leakage increased only at 1000 µmol Cd L-1, whereas protein oxidation and total soluble protein content were enhanced at 400 and 1000 µmol Cd L-1. Activity of APX was inhibited while the activities of CAT and SOD were increased at all Cd concentrations. Ascorbic acid was enhanced at 400 and 1000 µmol Cd L-1 whereas non-protein thiol groups were increased at all Cd supplies. The results evidence the importance of the enzymatic and non-enzymatic antioxidant system in response to cadmium toxicity in cucumber seedlings.
Nucleotide diversity of a major carotenoid biosynthetic pathway gene in wild and cultivated Solanum (Section Lycopersicon) species
Authors: Araújo Ana H. , Fonseca Maria Esther de N. , Boiteux Leonardo S.
Published: January 2008

A polymerase chain reaction (PCR)-based approach was employed to isolate putative alleles of the chromoplast-specific lycopene beta-cyclase (CYCB) gene from wild and cultivated tomatoes [Solanum (Section Lycopersicon)]. The objective of this work was to establish an effective PCR protocol by testing DNA samples from distinct germplasm accessions with a primer pair designed to selectively target conserved regions present in the available CYCB sequences. This PCR optimization allowed the amplification of 1219 out 1666 bp of the gene in six taxa: S. cheesmaniae, S. peruvianum, S. neorickii, S. pennellii, S. pimpinellifolium and S. lycopersicum. Sixty-three mutation sites (31 transitions, 18 transversions and 14 single base deletions/insertions) were detected in these accessions when compared to S. lycopersicum AF 254793 (used as reference sequence). The polymorphisms were found predominantly in green-fruited species (20 in S. neorickii, 20 in S. peruvianum, and 32 in S. pennellii). Lower levels of polymorphisms were found in yellow-fruited (three in S. cheesmaniae) and red-fruited species (eight in S. pimpinellifolium and none in the S. lycopersicum). The higher levels of nucleotide diversity in the CYCB-like gene sequences in accessions of green-fruited species as well as the phylogenetic tree agreed with the previous taxonomic studies based upon the granule-bound starch synthase gene phylogeny. Sequence analyses of the amplicons obtained via heterologous PCR indicated the CYCB gene-specificity of the primers. Therefore, this PCR-based strategy might be useful to isolate CYCB-like amplicons from other species within the genus Solanum and to develop molecular markers for assisted breeding.
A new species of Hypostomus Lacépède, 1803 (Siluriformes: Loricariidae) from the upper rio Paraná basin, Southern Brazil
Authors: Jerep Fernando C. , Shibatta Oscar A. , Zawadzki Cláudio H.
Published: January 2008

A new species of Hypostomus with large and spaced light roundish spots is described from the upper rio Paraná basin. Hypostomus multidens new species is distinguished from all remaining congeners with light spots on a darker background by two independent characters: the presence of teeth with two symmetrical cusps, and a high tooth number in each dentary (122267, mean 196.8) and premaxilla (115-260, mean 190.8).
Parasitic castration, growth, and sex steroids in the freshwater bonefish Cyphocharax gilbert (Curimatidae) infested by Riggia paranensis (Cymothoidea)
Authors: Lima Neuza R. W. , Azevedo Juliana de S. , Silva Leonardo G. da , Dansa-Petretski Marilvia
Published: January 2008

Cyphocharax gilbert shows parasitic castration when infested by the crustacean Riggia paranensis, being unable to reproduce. Fish were sampled in the middle rio Itabapoana, Brazil, to study the prevalence of parasitism, growth, and sex steroid concentrations, considering the body size, sex, and reproductive condition of specimens. Most of the fish analyzed were infested (56.0%). The presence of two lines on the scales was more frequent among infested fish (22.0%) than among fish without parasites (12.0% for females and 10.0% for males). The occurrence of three lines on the scales was rare (3.5% among infested and 2.0% among females without parasites). These results suggest that growth of the host is faster than that of non infested fish. The serum concentrations of sex steroids from fish without parasites varied at different gonadal development stages (17 beta-estradiol: 60.0 to 976.7 pg/ml; total testosterone: 220.0 to 3,887.7 pg/ml). All infested fish had lower levels of the two sex steroids and undeveloped gonads. Sex steroids levels in infested females were close to those in females at post-spawning stages. Total testosterone concentrations of infested males were below those of males at early gonadal maturation stage. These results suggest that R. paranensis reduces the reproductive capacity of C. gilbert by affecting the host endocrine system.
Fluxes of zooplankton biomass between a tidal estuary and the sea in Northeastern Brazil
Authors: Melo Júnior Mauro de , Paranaguá Maryse Nogueira , Schwamborn Ralf , Leitão Sigrid Neumann , Ekau Werner
Published: January 2008

The objective of this study was to quantify the zooplankton biomass transport between the Santa Cruz Channel (SCC) at Catuama north inlet and the adjacent shelf located in Itamaracá estuarine ecosystem, Pernambuco State, Northeastern Brazil. Sampling was carried out in August 2001 at spring and neap tides at three stations every 3-hour interval. Collections were made in three depths with a plankton pump coupled to a 300 µm mesh size net. Current data were obtained with an ADCP (Acoustic Doppler Current Profiler). In laboratory, samples were filtered for wet weigh determination. High biomass variation was recorded, with highest values at nocturnal flood and ebb during spring tide. The average instantaneous biomass transport was 139.48 ± 72.58 mg.m-2s-1, during spring tide and 36.63 ± 27.66 mg.m-2s-1, during neap tide. No significant difference was registered between importation and exportation flows (p > 0.05), showing that the estuary both exports and imports high biomass during the rainy season. It can be concluded that the outwelling at SCC is high, however, differently from other places, importation is also high, probably due to the presence of reefs and patches of seagrass (Halodule wrightii) toward the shelf that create a distinct productive environment.
Lactic-acid bacteria increase the survival of marine shrimp, Litopenaeus vannamei, after infection with Vibrio harveyi
Authors: Vieira Felipe do Nascimento , Pedrotti Fabiola Santiago , Buglione Neto Celso Carlos , Mouriño José Luiz Pedreira , Beltrame Elpídio , Martins Maurício Laterça , Ramirez Cristina , Arana Luis Alejandro Vinatea
Published: January 2008

This study evaluated the survival, post-larvae quality, and the population of bacteria in Litopenaeus vannamei after the addition of two strains of lactic-acid bacteria (2 and B6) experimentally infected by Vibrio harveyi. Fifteen hundred nauplii were distributed in 20 L capacity tanks with four replicates. The survival of control animals was lower (21%) than that of animals fed with the strains B6 (50%) and 2 (44%). Total bacterial population in the water and larvae, as well as of the Vibrio ssp. in water was not different among the treatments. No difference was observed in the population of Vibrio ssp. between the control larvae (5.5±0.5 log UFC/mL) and that fed with strain 2 (5.4±0.1 log UFC/mL). Shrimp from control and fed with strain 2 showed significantly higher bacterial population than those fed with strain B6 (1.2±0.2 log UFC/mL). It was detected the lower load of Vibrio ssp. bacteria with potential of pathogenicity after feeding with strain B6.Moreover, these larvae showed more active behavior and low number of necrosis in relation to the control group and to that fed with strain 2.
Anthropogenic nutrient pollution of coral reefs in Southern Bahia, Brazil
Authors: Costa Jr. Ozeas S.
Published: January 2008

Spatial, temporal and anthropogenic controls on nutrient distribution were evaluated for nearshore and offshore reefs at Porto Seguro Bay, Southern Bahia. Water samples were analysed for total oxidised nitrogen (TON), soluble reactive phosphorus (SRP), reactive silica (DSi), and chlorophyll a (Chl). The results indicate that rainfall promotes a significant (F=19.873, p<0.001) increase in the load of nutrients to nearshore (average 12% increase) and offshore reefs (average 31% increase). Nutrient concentrations at the urbanized reef (TON=1.93-3.21µM; SRP=0.57-0.89µM; DSi=8.48-11.15µM) are on average 25% higher than at non-urban reefs and over 200% higher than the offshore reef. The urbanized reef also presented the highest rates of increase in nutrient input between dry and rainy seasons (TON=+0.36µM; SRP=+0.08µM; DSi=+0.70µM). Differences in nutrient concentration between nearshore and offshore reefs are more pronounced during dry season, when the bulk of land-based nutrient contribution is confined to the nearshore reefs. SRP values in the study area ranked among the highest in the world for coral reef areas and phytoplankton growth appears to be nitrogen-limited.
Ichthyofauna composition across a wave: energy gradient on Southern Brazil beaches
Authors: Félix Fabiana Cézar , Spach Henry Louis , Moro Pietro Simon , Hackradt Carlos Werner , Queiroz Guilherme Mac Laren Nogueira de , Hostim-Silva Maurício
Published: January 2008

Wave action in sandy beach surf zones and its influence on species composition were evaluated at three sites at Pontal do Paraná, Paraná State, between June/2004 and May/2005. At each sampling site, five hauls were performed monthly using a 15 m long, 2.6 m height beach seine with a 5 mm mesh-size. Samplings were carried out at low water spring tides during daylight. A total of 26,866 fishes were collected, amounting to a total weight of 84,838 kg, which were distributed amongst 28 families and 63 taxa. Multi- and univariated methods used indicated that sheltered and moderately exposed beach samples had similar ichthyofaunal composition, being clupeids and engraulids the most abundant at these beaches. Although abiotic factors differed significantly between beaches, depth appears to exert the major influence on ichthyofauna structure by providing less turbulent waters which might have permitted shoals maintenance. Conversely, exposed beach samples differed largely from the other beaches and were influenced primarily by wave height and salinity variables. These were displayed at CCA diagram and through the occurrence of P. virginicus, M. littoralis and T. goodei.
Maurolicus stehmanni Parin & Kobyliansky, 1993 (Sternoptychidae): length of first maturation, and spawning seasons in the south-southeast Brazilian region
Authors: Almeida Eduardo Machado de , Rossi-Wongtschowski Carmen Lucia del Bianco
Published: January 2008

Maurolicus stehmanni (Sternoptychidae) is a mesopelagic species of fish inhabiting the outer continental shelf and slope of the south-southeastern Brazilian (ZEE), where it presents a considerable biomass and is an important component of the trophic chain, as a forage species. On the basis of catches made with a mid-water-trawl net in 1996 and 1997, as part of the REVIZEE program, samples from 38 hauls were analyzed as regards the length structure of the population, the average length of the first maturation and the spawning seasons of the species. The analysis of histological cross-sections of the ovaries made it possible to describe the oocytic development and assess the macroscopic criteria used to classify the ovary maturation. Results showed that the average length of the first maturation occurs at 32 mm (standard length), females spawn all year round throughout the area studied and the oocytic development is asynchronous.
Development of Human Cloned Blastocysts Following Somatic Cell Nuclear Transfer with Adult Fibroblasts
Authors: French Andrew J. , Adams Catharine A. , Anderson Linda S. , Kitchen John R. , Hughes Marcus R. , Wood Samuel H.
Published: January 2008

Nuclear transfer stem cells hold considerable promise in the field of regenerative medicine and cell-based drug discovery. In this study, a total of 29 oocytes were obtained from three young (20–24 years old) reproductive egg donors who had been successful in previous cycles. These oocytes, deemed by intended parents to be in excess of their reproductive needs, were donated for research without financial compensation by both the egg donor and intended parents after receiving informed consent. All intended parents successfully achieved ongoing pregnancies with the oocytes retained for reproductive purposes. Mature oocytes, obtained within 2 hours following transvaginal aspiration, were enucleated using one of two methods, extrusion or aspiration, after 45 minutes of incubation in cytochalasin B. Rates of oocyte lysis or degeneration did not differ between the two methods. Somatic cell nuclear transfer (SCNT) embryos were constructed using two established adult male fibroblast lines of normal karyotype. High rates of pronuclear formation (66%), early cleavage (47%), and blastocyst (23%) development were observed following incubation in standard in vitro fertilization culture media. One cloned blastocyst was confirmed by DNA and mitochondrial DNA fingerprinting analyses, and DNA fingerprinting of two other cloned blastocysts indicated that they were also generated by SCNT. Blastocysts were also obtained from a limited number of parthenogenetically activated oocytes. This study demonstrates, for the first time, that SCNT can produce human blastocyst-stage embryos using nuclei obtained from differentiated adult cells and provides new information on methods that may be needed for a higher level of efficiency for human nuclear transfer.

Disclosure of potential conflicts of interest is found at the end of this article.
Dose Estimation and Surveillance of Mechanical Loading Interventions for Bone Loss After Spinal Cord Injury
Authors: Dudley-Javoroski Shauna , Shields Richard K
Published: January 2008

Background and Purpose

The interpretation of the results of previous anti-osteoporosis interventions after spinal cord injury (SCI) is undermined by incomplete information about the intervention dose or patient adherence to dose requirements. Rehabilitation research as a whole traditionally has struggled with these same issues. The purpose of this case report is to offer proof of the concepts that careful dose selection and surveillance of patient adherence should be integral components in rehabilitation interventions.

Case Description

A 21-year-old man with T4 complete paraplegia (7 weeks) enrolled in a unilateral soleus muscle electrical stimulation protocol. Compressive loads applied to the tibia approximated 1.4 times body weight. Over 4.8 years of home-based training, data logging software provided surveillance of adherence. Soleus muscle torque and fatigue index adaptations to training as well as bone mineral density (BMD) adaptations in the distal tibia were measured.

Outcomes

The patient performed nearly 8,000 soleus muscle contractions per month, with occasional fluctuations. Adherence tracking permitted intervention when adherence fell below acceptable values. The soleus muscle torque and fatigue index increased rapidly in response to training. The BMD of the untrained tibia declined approximately 14% per year. The BMD of the trained tibia declined only approximately 7% per year. The BMD was preferentially preserved in the posterior half of the tibia; this region experienced only a 2.6% annual decline.

Discussion

Early administration of a load intervention, careful estimation of the loading dose, and detailed surveillance of patient adherence aided in the interpretation of a patient's adaptations to a mechanical load protocol. These concepts possess wider applicability to rehabilitation research and should be emphasized in future physical therapy investigations.
Intrahousehold Interaction Analysis between Husband, Wife, and Child Using Joint Time-Allocation Model
Authors: Kato Hironori , Matsumoto Manabu
Published: January 2008

This paper describes research on intrahousehold interactions, based on results of an activity-based time allocation model. The paper describes a joint time-allocation model that explicitly considers a child in addition to parents. It analyzes activity duration as well as activity type. This model was formulated as a nonlinear Tobit model for econometric analysis. The model parameters were estimated with data from a household time-allocation survey completed during 2003 in Toyama, Japan. Two models were estimated with the sample data sets: one for weekdays and one for weekend days. The results indicate that social and cultural backgrounds relating to the husband's preference of child gender, household child-care role sharing between husband and wife, and the husband's immersion in work influence the household interactions significantly. The paper presents a summary of model results, conclusions, and recommendations for further research.
Agent-Oriented Coupling of Activity-Based Demand Generation with Multiagent Traffic Simulation
Authors: Rieser Marcel , Nagel Kai , Beuck Ulrike , Balmer Michael , Rümenapp Jens
Published: January 2008

The typical method to couple activity-based demand generation (ABDG) and dynamic traffic assignment (DTA) is time-dependent origin-destination (O-D) matrices. With that coupling method, the individual traveler's information gets lost. Delays at one trip do not affect later trips. However, it is possible to retain the full agent information from the ABDG by writing out all agents' plans, instead of the O-D matrix. A plan is a sequence of activities, connected by trips. Because that information typically is already available inside the ABDG, this is fairly easy to achieve. Multiagent simulation (MATSim) takes such plans as input. It iterates between the traffic flow simulation (sometimes called network loading) and the behavioral modules. The currently implemented behavioral modules are route finding and time adjustment. Activity resequencing or activity dropping are conceptually clear but not yet implemented. Such a system will react to a time-dependent toll by possibly rearranging the complete day; in consequence, it goes far beyond DTA (which just does route adaptation). This paper reports on the status of the current Berlin implementation. The initial plans are taken from an ABDG, originally developed by Kutter; to the authors' knowledge, this is the first time traveler-based information (and not just O-D matrices) is taken from an ABDG and used in a MATSim. The simulation results are compared with real-world traffic counts from about 100 measurement stations.
Modeling Adults' Weekend Day-Time Use by Activity Purpose and Accompaniment Arrangement
Authors: Kapur Aarti , Bhat Chandra R.
Published: January 2008

This paper examines the weekend time use patterns of individuals aged 15 years or older, with an emphasis on their maintenance and discretionary activities. The analysis considers the social context of activity participation by considering the with-whom dimension of the participations. The sample for analysis is drawn from the 2004 American Time Use Survey. Bhat's multiple discrete-continuous extreme value model is used in the empirical analysis. The results underscore the importance of considering the social context of activity participation within the framework of activity-based travel modeling.
Stated Adaptation Survey of Activity Rescheduling
Authors: Roorda Matthew J. , Andre Brandon K.
Published: January 2008

This paper describes an analysis of activity rescheduling responses to an unexpected 1-h delay in getting to an activity. To focus on this rescheduling scenario, a stated adaptation survey technique was developed in which the hypothetical scenario of an unexpected 1-h delay was introduced to a randomly chosen activity from the observed 2-day executed activity schedules of respondents. This paper describes the survey technique used to elicit stated adaptation responses to this conflict, an exploratory univariate analysis of the explanatory factors, and the results of a simple multinomial logistic regression model that attempts to explain the combined effects of a variety of explanatory variables. Finally, a comparison is made with other revealed preference data from an interactive scheduling process survey to shed light on the differences in rescheduling strategies for activity conflicts without forewarning. Attributes of the activity are the major influences behind the type of rescheduling actions taken. The only person and household attributes found to influence the response significantly are the involvement of children in the activity and the student status of the individual for whom the delay occurs. Schedule attributes are not found to have a significant effect. Some new evidence suggests that when conflicts occur with little forewarning, people are less likely to skip or change the day of the activity and more likely to shorten it, where possible, or shift it to another part of the day.
Recurrence of Daily Travel Patterns
Authors: Bayarma Alexander , Kitamura Ryuichi , Susilo Yusak O.
Published: January 2008

Multiday travel behavior was examined as a stochastic process, and new empirical findings are offered on the variation of travel patterns from day to day. The analysis was based on data from a 6-week travel diary survey conducted in Germany. A small number of travel pattern classes were identified, and transitions in the patterns over a course of weeks were analyzed with Markov chain models. Transitions from a pattern to itself are frequent, particularly for nonworkers, and indicate that some patterns tend to be pursued for a large number of consecutive days. The study also reveals that individuals are heterogeneous in terms of multiday travel behavior; pattern-to-pattern transition probabilities vary substantially across individuals. Some of the observable heterogeneity is demonstrated in terms of the association between attributes of the individual and the recurrence of daily travel patterns.
Capturing Human Activity Spaces
Authors: Rai R. K. , Balmer Michael , Rieser Marcel , Vaze V. S. , Schönfelder Stefan , Axhausen Kay W.
Published: January 2008

“Activity space,” defined as the local areas within which people move or travel during the course of their activities during a specified time period, is a measure of an individual's spatial behavior that captures individual and environmental differences and offers an alternative approach to studying the spatial reach of travelers. The shape and the area of activity space are a product of how it is conceptualized and measured. This paper enlarges the set of geometries that can be used to describe activity space. It tests four parametric geometries (ellipse, superellipse, Cassini oval, and bean curve), which are identified as those capturing a specific share of all locations visited (i.e., 95%) while minimizing the area covered. They are estimated for a number of long-duration data sets while distinguishing among trip purposes. This paper presents a flexible, easily adaptable method for calculating activity spaces of different shapes and a qualitative comparison of the four shape types on the basis of the given surveys. The choice of an appropriate shape representing an individual's activity space is highly dependent on the spatial distributions and frequencies of the locations visited by the person in the given time period.
Identifying Skeletal Information of Activity Patterns by Multidimensional Sequence Alignment
Authors: Joh Chang-Hyeon , Arentze Theo , Timmermans Harry
Published: January 2008

String-alignment techniques, which were introduced in biology to measure similarity between DNA strings or protein sequences, find increasing application in travel behavior research to analyze activity-travel patterns. This paper explores a method to identify common elements, referred to as skeletons, in multidimensional activity patterns by using a multidimensional string-alignment technique that the authors developed. The method identifies the skeletal information of the multidimensional activity patterns of a group and describes the results of an application to an activity diary set. The analysis reveals structural patterns in the activity patterns and well-interpretable differences in patterns between males and females. The method offers a promising approach to activity analysis.
Mobility Management in Japan
Authors: Taniguchi Ayako , Suzuki Haruna , Fujii Satoshi
Published: January 2008

This study examined the history, current situation, and characteristics of mobility management (MM) in Japan and quantitatively analyzed the effectiveness of MM in Japan by extending a previous meta-analysis to include data until 2003. The most frequently used MM method in Japan involves travel feedback programs (TFPs). For the meta-analysis, all reports and research papers describing TFP implementations in Japan published in or before December 2005 were collected. Thirty-one cases of MM had been implemented in residential areas, schools, and workplaces. This study focused on TFPs implemented in residential areas, for which many reports and larger sample sizes exist. The analysis results indicate that TFPs in residential areas of Japan reduced car use by 7.3% to 19.1% and increased public transport use by 30.0% to 68.9% on average. Analysis of the effectiveness of TFP techniques indicated that goal setting leads to significant changes in travel behavior from car use to more sustainable transport.
Who Chooses to Carpool and Why?
Authors: Li Jianling , Embry Patrick , Mattingly Stephen P. , Sadabadi Kaveh Farokhi , Rasmidatta Isaradatta , Burris Mark W.
Published: January 2008

The debate over high-occupancy vehicle (HOV) and high-occupancy toll lane efficiency has raised questions about whether HOVs should be given preferential treatment on managed lanes and the potential impacts of different preferential treatments. This research questions why people choose their mode of travel by examining characteristics of carpoolers and single-occupancy vehicles, reasons for their travel mode choice, and carpool formation, on the basis of a survey of travelers in Dallas-Fort Worth and Houston in Texas. Carpool users rated the ability to use HOV lanes as the most important factor in their decision to form a carpool. Enjoying traveling with others ranked second, followed by reasons such as saving time, helping the environment and society, and sharing vehicle costs. Carpool partner matching programs, employer carpool incentives, and preferred parking at work were generally the least important factors in travelers' consideration of carpooling. The importance of various factors changed significantly if the respondent was on a work or commute trip versus other trip modes. Travelers on work or commute trips ranked travel time savings and cost sharing much higher, as expected, because of their frequent travel during peak hours. The data also support evidence of a significant amount of “fampooling,” with nearly 75% of carpools consisting of family members. The implications of these findings are discussed.
Commuter Parking versus Transit-Oriented Development
Authors: Willson Richard , Menotti Val
Published: January 2008

Transit agencies face a tension between providing commuter parking at rail stations and encouraging transit-oriented development (TOD) on the land the parking occupies. This paper describes a multiobjective model designed to facilitate decision making about TOD and commuter parking. The model, developed by the San Francisco Bay Area Rapid Transit District (BART) in California to facilitate station planning and development, examines ridership impacts, fiscal impacts, and qualitative factors. The analysis shows the conditions under which positive ridership and fiscal outcomes occur if BART deviates from its practice of requiring one-to-one replacement of commuter parking. Using the MacArthur and San Leandro stations as case studies, the analysis reveals the substantial opportunity cost of retaining transit agency land in surface parking as well as the sensitivity of results to local conditions and policy. The spreadsheet-based methodology is adaptable to a wide variety of situations. The paper concludes with observations about how this model affected perceptions and policy deliberations of transit agency staff and elected officials.
Urban Wayfinding Signs: Evaluating Exceptions to FHWA's Standard Alphabets
Authors: Garvey Philip M.
Published: January 2008

Like many cities in the United States, Miami Beach, Florida, has developed a wayfinding signage plan for its urban neighborhoods. The architectural firm hired by the city recommended use of the Futura typeface; however, the federal Manual on Uniform Traffic Control Devices and by reference the Standard Highway Signs book specify that all signs on public access roads in the United States shall use the Standard Alphabet typeface. For FHWA to approve an alternative typeface, such as Futura, its visibility must be shown through valid scientific experimentation to be equal to or greater than the comparable Standard Alphabet series. This report documents a research project requested by the Florida Department of Transportation and FHWA to determine whether Futura provides this level of visibility. The research was conducted with full-sized wayfinding signs located on city streets in the Miami Beach area. A group of 34 older and younger motorists viewed the signs from a vehicle driven through live traffic at operating speeds representative of the area. The research conducted here shows that the Futura typeface, when used in accordance with the wayfinding system proposed for the city streets of Miami Beach, provides sign legibility and recognition distances equal to or greater than the comparable Standard Alphabet Series B and C. This research effort presents a model test method for evaluating exceptions to FHWA's Standard Alphabet for use in urban wayfinding sign systems.
Development of Crash Reduction Factors for Overhead Flashing Beacons at Rural Intersections in North Carolina
Authors: Murphy Brian G. , Hummer Joseph E.
Published: January 2008

The purpose of this project is to develop crash reduction factors for overhead flashing beacons at rural two-way stop sign–controlled intersections in North Carolina. Overhead flashing beacons are a common counter-measure used in North Carolina to help alleviate crash problems at intersections where drivers have difficulty recognizing the stop-control condition. The goal of this analysis is to develop crash reduction factors that reflect North Carolina conditions and decision making. Thirty-four treatment sites were chosen for analysis. Each treatment site was a rural four-leg intersection with no turn lanes and two-way stop control. Each treatment site had at least 3 years of after-period crash data available. Several methodologies were used to calculate the crash reduction factors. The biggest threats to the validity of the analysis that must be accounted for at the 34 treatment sites in this study were regression to the mean and the increase in traffic volumes. Regression to the mean is a significant threat as each treatment site was chosen because of its crash history. The increase in traffic volumes was also a concern because of the long duration of before-and-after periods at each site. Empirical Bayes before-and-after techniques were used to overcome the threat of regression to the mean. One hundred and seventy reference sites were chosen and the method of sample moments was carried out to calculate the necessary parameters. A linear assumption was used to account for the increase in traffic flow. On average, all categories of crashes studied decreased in the after period.
Guidelines for Minimum Signal Sight Distance
Authors: Mokkapati Naveen , Hawkins H. Gene
Published: January 2008

The guidelines for minimum visibility distance in the 2003 Manual on Uniform Traffic Control Devices (MUTCD) are based on a research model developed in 1977, a portion of which was based on stopping sight distance concepts from 1965. Since then, roadway design criteria, vehicle performance characteristics, and driver characteristics have changed. These changes provide justification for reevaluating the guidelines for minimum signal sight distance. This paper identifies the basis for the current guidelines (which were not published) and develops updated guidelines for signal sight distance. As with the original guidelines, the updated guidelines are based on a theoretical model that addresses reaction time, braking distance, and queue length. The key changes incorporated into the updated model are calculating the stopping distance on the basis of deceleration rates, using a reaction time consistent with the AASHTO stopping sight distance, and eliminating the provision for a vehicle queue at the stop line, as the driver should be able to respond to the queue on the basis of the stopping sight distance provided by the road. The updated values for minimum signal sight distance are typically 20% to 25% less than those currently in the MUTCD. The lack of guidance in the MUTCD about placement of the “Signal Ahead” sign is also pointed out, and it is suggested that it be located on the basis of the signal sight distance and not according to warning sign placement guidelines.
Reducing Undesirable Actions of Motor Vehicle Drivers at Railroad–Highway Grade Crossings
Authors: Khattak Aemal J.
Published: January 2008

This paper reports on unsafe actions of motor vehicle drivers at gated railroad–highway grade crossings and behavioral modifications in response to installation of a centerline barrier that prevented drivers from going through the gates. A comparison of driver behavior in the pre- and postbarrier periods indicated the effectiveness of the barrier in reducing unsafe actions. A major concern of the Nebraska Department of Roads is the potential for crashes at railroad–highway grade crossings that result from unsafe actions of motorists such as rushing the gates to beat an oncoming train and playing “chicken” with an approaching train (i.e., intentionally standing a motor vehicle on the tracks and moving only when the train brakes). Some driver actions at crossings (e.g., backing up, U-turns) may result in crashes involving motor vehicles only. The railroad crossing at North 141st Street in Waverly, Nebraska, was studied for about 4 months with the help of a night vision camera and a digital video recorder. Motor vehicle driver behavior was observed when the gates were down, and unsafe actions were noted. To reduce gate rushing and other unsafe behaviors, a flexible rubber and plastic barrier was installed to prevent motorists from going through the gates. The postbarrier actions of motor vehicle drivers were monitored and compared with the preinstallation period by using appropriate statistical tools. The results provide interesting insights into how drivers modify their actions in response to physical changes at railroad crossings, in this case installation of a barrier along the street centerline. The barrier reduced some of the more dangerous types of driver actions such as gate rushes.
Warranting Traffic Signals on the Basis of Proximity of Railroad Grade Crossings
Authors: Prassas Elena Shenk , McShane William R. , Lieberman Edward , Engelbrecht Roelof
Published: January 2008

There were two concurrent paths in this research. Path 1 estimated the probability, pvehicle/train, that a vehicle will be in the train dynamic envelope given that a train arrives. This was done by an extensive simulation effort that included some data collection on relevant gap acceptance patterns. Path 2 identified the exposure factors, selected a risk metric, and established a target or threshold for the risk, which is expressed as an upper bound on pvehicle/train. As a result of the investigation, the warrant is based on the principle that the expected fatality rate at the crossing should not exceed rates found at unsignalized intersections. The two paths converged by expressing the constraint pvehicle/train ≤ ___ (where ___ is in terms of traffic terms in common use—e.g., volumes, composition, track location distances). This constraint led to the warrant, which was then validated with data acquired or collected for the purpose. The draft warrant was prepared as a result of the undertaking, was endorsed by the National Committee on Uniform Traffic Control Devices, and is currently in the formal review process, culminating in final edits and a decision on inclusion in the next edition of the Manual on Uniform Traffic Control Devices.
Traffic Control Devices and Barrier Systems at Grade Crossings: Literature Review
Authors: Yeh Michelle , Multer Jordan
Published: January 2008

Accidents at grade crossings are a significant concern to the railroad industry, and a large proportion of these accidents are the result of driver error. To understand drivers' decisions and actions, FRA sponsored the Volpe National Transportation Systems Center in the conduct of a literature review of research from 1990 to 2006 examining driver behavior at grade crossings. This review is intended to update the 1990 report Driver Behavior at Rail-Highway Crossings and to provide input for developing countermeasures to discourage dangerous driving behavior. This paper summarizes a small portion of the problem and presents findings from the review addressing the design and effectiveness of grade crossing traffic control devices and barrier systems. Although drivers generally understand that a grade crossing is nearby upon seeing one of five warning devices (crossbuck, advance warning sign, pavement markings, flashing light signals, and automatic gates), the precise meaning of the devices and the driver action required may not be well discriminated. This paper addresses the design of signs and presents the results of evaluations examining driver detection, comprehension, and compliance with current and proposed warning sign systems; discusses a way to improve the design of pavement markings; examines the causes for noncompliance at active crossings and considers ways to improve compliance by introducing barrier systems and by improving warning device credibility; and makes recommendations for practitioners and suggestions for additional research.
US-36 Environmental Impact Statement and Basic Engineering: Methodology of Grade Crossing Evaluation
Authors: Lee Nadine S.
Published: January 2008

A study was conducted in support of the US-36 Environmental Impact Statement for the proposed commuter rail corridor between Denver and Boulder, Colorado, which determined when consideration of a grade separation may be appropriate for rail crossings in the corridor. The analysis involved three criteria: safety, vehicular travel delay, and feasibility. The methodology for evaluating crossings for grade separation is presented for agencies undertaking roadway–railroad intersection projects to consider. The analysis uses an accident prediction tool in the FRA GradeDec.NET software to assess safety risk and proposes a risk threshold. The evaluation of vehicular travel delay uses standard equations from the Highway Capacity Manual to compare estimated delay with intersection level of service and thus to define an allowable threshold for the project. This paper discusses physical, environmental, social, public, and financial feasibility to help users determine quickly whether any of these factors constitutes a fatal flaw for the analysis. The procedures described establish a methodology for planners and engineers to determine the feasibility of maintaining a roadway–railroad crossing in its existing configuration when implementing a higher-frequency service along an existing railroad corridor. With this method, planning level information may be derived and applied to perform the safety and vehicular travel delay analyses. Users may do a quick screening to eliminate crossings that can operate safely and efficiently with minimal modifications; the responsible agency can then focus time and money on areas that may present challenges to safe and efficient operations.
Comparison of high- versus low-tissue affinity ACE-inhibitor treatment on circulating aldosterone levels in patients with chronic heart failure
Authors: Vittorio Timothy J , Ahuja Kartikya , Kasper Michael , Turalic Haris , Tseng Chi-Hong , Jorde Ulrich P , Gor Chirayu
Published: January 2008

Introduction. Previous animal studies of chronic heart failure (CHF) suggest that angiotensin-converting enzyme (ACE) inhibitors of differing tissue avidity provide varying levels of renin-angiotensin system (RAS) suppression. Human studies have not consistently confirmed these animal findings. We hypothesised that production of circulating aldosterone (ALDO) would be suppressed to a greater extent in subjects treated with an ACE-inhibitor of higher tissue avidity. We randomised subjects with stable CHF to receive the low-tissue affinity ACE-inhibitor enalapril (ENAL) or the high-tissue affinity ACE-inhibitor trandolapril (TRAN), and assessed circulating ALDO levels at baseline and after eight weeks of treatment.

Methods. Thirty clinically stable subjects with CHF and left ventricular ejection fraction (LVEF ) < 40% who were in a steady-state fluid balance were enrolled into a prospective, randomised double-blind trial. After a one month run-in period for standardisation to initial ACE-inhibition with ENAL, baseline circulating ALDO levels were measured and patients were randomised to receive ENAL 40 mg versus O TRAN 4 mg (or the maximally tolerated doses) for eight weeks. Final determination of ALDO levels were made at the end of the 8-week study period.

Results. Baseline clinical characteristics including age, diabetes, LVEF, serum sodium, potassium and creatinine concentrations, and background medications were similar in both groups. We found no statistically significant difference in circulating ALDO levels between the ENAL and TRAN groups at the end of the 8-week study period. [ENAL (12.6 vs. 13.3 ng/dL);TRAN (12.5 vs. 14.5 ng/dL);p=NS].

Conclusion. We found no statistically significant difference in circulating ALDO levels between high- and low-tissue affinity ACE-inhibitor therapy. Further studies assessing ALDO production at the tissue level is warranted.
Genetic polymorphisms of the renin-angiotensin system in preterm delivery and premature rupture of membranes
Authors: Valdez-Velazquez Laura L , Quintero-Ramos Antonio , Perez Sandra A , Mendoza-Carrera Francisco , Montoya-Fuentes Hector , Rivas Fernando , Olivares Norma , Celis Alfredo , Vazquez Oscar F , Rivas Fernando
Published: January 2008

Introduction. Premature rupture of membranes (PRM) is a late pregnancy complication commonly associated with preterm delivery (PD).Although several markers related to the renin-angiotensin system (RAS) have been evaluated in certain pregnancy complications, only the angiotensin-converting enzyme (ACE) I/D variant has been studied in PD-PRM.The aim of this survey was to investigate the association of the polymorphisms (angiotensin II type 1 [AT1] receptor T174M and M235T, renin G2805A,ACE I/D and AT1-receptor A1166C) of the genes of RAS in women with PD-PRM.

Design. Deoxyribonucleic acid samples from 89 Mexican Mestizo women with PD and PRM and 224—288 controls were studied. Polymorphisms were analysed by polymerase chain reaction-sequence specific primer assays. restricted fragment length polymorphism or sequence specific prim assays.

Results. For all loci , genotype distribution was in agreement with Hardy—Weinberg expectations in the control group. Significant intergroup difference (case vs. control) was seen for angiotensinogen (AGT) M235T polymorphism, with an increased allele M235 in affected cases (50% vs. 40% in controls).Analysis of two- locus haplotype agrees with an independent segregation of physically unlinked genes. Haplotype AGT 174T-235M was also increased (50 % vs. 40% in controls).

Conclusions. Physically unlinked genes involved in RAS segregate independently. The AGT 174—235 region is associated with PD-PRM in this population.
Augmented myocardial methionine-enkephalin in a murine model of cardiac angiotensin II-overexpression
Authors: van den Brink Olivier WV , Delbridge Lea M Durham , Pedrazzini Thierry , Rosenfeldt Franklin L , Pepe Salvatore
Published: January 2008

Introduction. The endogenous opioid system has been reported to interact with both the cardiac sympathetic and renin-angiotensin systems in exerting a local regulatory action on the heart.The goal of this investigation was to examine how cardiac levels of enkephalin production are altered in the development of normotensive primary hypertrophy due to elevated intra-cardiac angiotensin II (Ang II) production.

Methods. Atrial and ventricular methionine-enkephalin (ME) levels were measured by quantitative radioimmunoassay in 14 and 28-week-old male transgenic mice (TG1306/1R) and control mice.The TG1306/1R exhibit cardiac specific Ang II overexpression and cardiac hypertrophy, but not hypertension.

Results. TG1306/1R mice had significantly higher heart/body weight ratios H (15—20%) than control littermates at both 14 (p=0.02) and 28 weeks (p=0.04). Relative to controls, ME content was significantly elevated (approximately twofold) in atria and ventricles in the older 28-week TG1306/1R mice only. A significant inverse correlation between heart size and ME level was observed for 28-week TG1306/1R only.

Conclusions. We have provided evidence that a marked elevation of myocardial enkephalin level is observed in the established (but not early) phase of cardiac hypertrophy associated with cardiac-specific Ang II-overexpression.This study identifies a potentially important relationship between two endogenous peptidergic signalling systems involved in the regulation of growth and function of the hypertrophic heart.
Assessment of brain AT1-receptor on the nocturnal basal and angiotensin-induced thirst and sodium appetite in ovariectomised rats
Authors: de Souza Mecawi André , Lepletier Ailin , Gomes de Araujo Iracema , Lopes Olivares Emerson , Reis Luís Carlos
Published: January 2008

Objective. Considering the controversial data regarding the role of the brain renin-angiotensin system (RAS) on the thirst and sodium appetite in ovariectomised rats, we aimed to evaluate the role of the brain angiotensin II (Ang II) AT1-receptor on the nocturnal fluids intake.

Materials and methods. Groups of Wistar female rats were ovariectomised and chronically given oestrogen or vehicle to evaluate its influence on effects induced by i.c.v. injection of losartan,Ang I and Ang II.

Results. The i.c.v. losartan decreased basal water intake in the ovariectomised group.Ang II but not Ang I-induced nocturnal dipsogenic and natriorexigenic responses in ovariectomised rats. In oestrogen-treated rats, both peptides increased fluids intake. Previously, i.c.v. losartan abolished these effects in all groups. Oestrogen replacement decreased the nocturnal fluids intake, attenuated the losartan and Ang II effects, and highlighted the Ang I response.

Conclusions. The present study has shown for the first time the involvement of AT1-receptor in regulating nocturnal basal water and salt intake in ovariectomised rats. In addition, our data have revealed an unexpected increased brain Ang I-mediated fluid intake in oestrogen-treated ovariectomised compared to ovariectomised rats, which was blocked by previous i.c.v. losartan. Our data have therefore shown that oestrogen influences homeostatic behaviours dependent on brain RAS.