bluuebunny/crossref_metadata_2025 huggingface dataset:
Development of a Coupling‐Phase SCAR Marker Linked to the Ur‐7 Rust Resistance Gene and Its Occurrence in Diverse Common Bean Lines
Authors: Park S. O. , Steadman J. R. , Coyne D. P. , Crosby K. M.
Published: January 2008

Bean rust, caused by Uromyces appendiculatus (Pers.:Pers.) Unger, is an important disease of common bean (Phaseolus vulgaris L.). A coupling‐phase random amplified polymorphic DNA (RAPD) marker OAD12.550 previously was identified to be linked (no recombination) to Ur‐7 of Middle American (MA) origin for specific rust resistance in the common bean cross of Great Northern (GN) 1140 × GN Nebr. #1. However, a sequence characterized amplified region (SCAR) marker for Ur‐7 present in GN1140 has not been reported. Our objectives were to convert the RAPD marker OAD12.550 most tightly linked to Ur‐7 to a SCAR marker SOAD12.537 for use as a marker‐assisted selection tool, and survey the presence or absence of the SCAR marker SOAD12.537 in 90 MA and Andean bean genotypes for determining the genetic relationship of Ur‐7 with Ur‐6 The coupling‐phase SCAR marker SOAD12.537 based on a specific forward (5′‐AAGAGGGCGTGAGATCGTCG‐3′) and reverse (5′‐AAGAGGGCGTCTTGAAGGTT‐3′) primer pair showed no recombination with Ur‐7 in an F2 population of the GN1140 × Nebr. #1 cross. The SCAR marker was also present in pinto US‐5 from which the rust resistance of GN1140 was derived and in the closely related pinto US‐14. The cosegregating SCAR marker identified MA pinto bean cultivars/lines Olathe, Bill Z, Apache, Montrose, BelDak‐RR‐1 and‐2, and CO 12783 that have rust resistance gene Ur‐6 and also have Ur‐7, identified in earlier literature as Urc, due to presence of the marker. Other cultivars/lines with Ur‐6 such as Weihing, Burke, Kodiak, Topaz, Golden Gate Wax, BelMiNeb 1–13, BelDakMi 1–23, and other Colorado breeding lines lack Ur‐7 because of absence of the SCAR marker for the MA gene. This SCAR marker linked to Ur‐7 on linkage group 11 of the core P. vulgaris linkage map can identify a phenotypically hidden resistance gene, and along with markers for other rust resistance genes, can be utilized to pyramid multiple genes for more durable rust resistance.
Gene Action Controlling Gray Leaf Spot Resistance in Southern African Maize Germplasm
Authors: Derera John , Tongoona Pangirayi , Pixley Kevin V. , Vivek Bindiganavile , Laing Mark D. , van Rij Neil C.
Published: January 2008

Gray leaf spot disease (GLS; caused by Cercospora zeae‐maydis Tehon and Daniels) is among the major maize (Zea mays L.) production constraints in southern Africa. Maize is predominantly grown by small‐scale farmers without fungicides; hence, there is need to develop GLS resistant hybrids. There is limited information about the mode of inheritance for GLS resistance in regionally adapted germplasm. This study was initiated to determine gene action controlling GLS resistance. Seventy‐two hybrids were generated by mating 27 inbred lines in a North Carolina design II scheme. Experimental and check hybrids were evaluated in an 8 by 12 α‐lattice design with two replications at three locations, during the 2004–2005 season. There was significant variation among the hybrids for GLS resistance and yield. Inbreds L13, L15, L18, L19, and L24, from A, N3, B, K, and SC heterotic groups, respectively, contributed high levels of resistance to hybrids. Both general combining ability (GCA) and specific combining ability (SCA) effects were highly significant (P < 0.01), but the predominance of GCA for GLS (86%) and yield (74%) indicated that additive effects were more important than nonadditive gene action in controlling both traits. Hybrids ranked similarly for GLS across environments, suggesting that few significant crossover genotype by environment interactions, which would cause problems in hybrid selection, were observed. Overall, results indicated that it would be readily possible to develop inbred lines with high GLS resistance from this germplasm.
Yield, Root Growth, and Soil Water Content in Drought‐Stressed Pasture Mixtures Containing Chicory
Authors: Skinner R. Howard
Published: January 2008

Chicory (Cichorium intybus L.), a deep‐rooted forb, has potential for inclusion in pasture mixtures because of its reported drought tolerance and high productivity during summer months. This study examined how adding chicory to pasture mixtures affected forage yield, root growth, and soil moisture extraction under drought. The experiment was planted in August 2002. Movable rainout shelters were used to control water application in the field. Adding chicory to orchardgrass (Dactylis glomerata L.)–white clover (Trifolium repens L.) or perennial ryegrass (Lolium perenne L.)–white clover mixtures increased drought tolerance in 2003 when chicory constituted 24 to 39% of harvested forage biomass. Chicory mortality was high, decreasing from 39% of harvested forage yield under drought stress in early summer 2003 to 9% in late summer 2004. Improved yield under drought stress was not observed in 2004 when chicory constituted only 9 to 16% of the mixture. The three‐species mixtures in 2003 had greater root counts than the two‐species mixtures at soil depths below about 70 cm under well‐watered conditions, but a greater proliferation of roots at depths below 70 cm was observed for the two‐species mixture under drought stress. Both mixtures appeared capable of nighttime transfer of soil water from deep to shallow soil layers, thereby improving water availability to shallow roots. However, improved drought tolerance of the three‐species mixture was probably related to improved water use efficiency rather than to greater access to and extraction of deep soil moisture.
Diagnostic Microsatellite Markers for the Detection of Stem Rust Resistance Gene Sr36 in Diverse Genetic Backgrounds of Wheat
Authors: Tsilo Toi J. , Jin Yue , Anderson James A.
Published: January 2008

The wheat stem rust resistance gene Sr36, derived from Triticum timopheevi, confers a high level of resistance against a new race (TTKS, or commonly known as Ug99) and many other races of Puccinia graminis f. sp. tritici Because Sr36‐virulent races exist, breeding for durable resistance would require pyramiding Sr36 with other genes, a process that can be facilitated by DNA markers. The aim of this study was to identify and validate microsatellite markers for the detection of Sr36 in wheat breeding programs. Two populations of 122 F2 (LMPG × Sr36/9*LMPG) and 112 F2 (‘Chinese Spring’ × W2691Sr36‐1) were evaluated for stem rust reaction. Both populations exhibited distorted segregation with a preferential transmission of the Sr36‐carrying segment. Three markers, Xstm773‐2, Xgwm319, and Xwmc477, were in complete linkage with Sr36 in the LMPG × Sr36/9*LMPG population. In the Chinese Spring × W2691Sr36‐1 population, Xgwm319 was 0.9 cM away from Xstm773‐2, Xwmc477, and Sr36 These codominant markers were easy to score and diagnostic for Sr36 in a set of 76 wheat cultivars and breeding lines developed in 12 countries. Together, these markers can be used in marker‐assisted selection of Sr36
Impact of Seaweed Extract‐Based Cytokinins and Zeatin Riboside on Creeping Bentgrass Heat Tolerance
Authors: Zhang Xunzhong , Ervin E. H.
Published: January 2008

Heat stress is the primary factor limiting summer performance of creeping bentgrass (Agrostis stolonifera L.) in many temperate to subtropical regions. Seaweed extract (SWE)‐based cytokinins have been used to improve stress tolerance, but their specific effects on creeping bentgrass under supraoptimal temperatures are lacking. This study was designed to determine whether SWE‐based cytokinins affect creeping bentgrass heat tolerance, and to compare effects of SWE‐based cytokinins to those of a trans‐zeatin riboside (t‐ZR)‐standard. Concentrations of t‐ZR in two SWE sources (referred to as Oce and Aca) were determined. Treatments were applied twice to creeping bentgrass at an equivalent t‐ZR concentration of 10 μM. One week after the initial treatment, heat stress was imposed (35/25°C [day/night]) for 42 d. The Oce SWE, Aca SWE, and t‐ZR treatments resulted in leaf t‐ZR concentrations that were 39, 32, and 28% higher, respectively, relative to the control at 14 d of heat stress. The Oce SWE, Aca SWE, and t‐ZR treatments also increased superoxide dismutase activity and alleviated the decline of turfgrass quality, photochemical efficiency, and root viability. Ashed SWE provided results similar to the water control. Beneficial effects of SWE on heat tolerance appear to be associated with their organic, especially cytokinin, components and not the mineral (ashed) fraction. Proper application of SWE‐based cytokinins may be an effective approach to improve summer performance of creeping bentgrass.
Reproductive Biology of Cassava (Manihot esculenta Crantz) and Isolation of Experimental Field Trials
Authors: Halsey Mark E. , Olsen Kenneth M. , Taylor Nigel J. , Chavarriaga‐Aguirre Paul
Published: January 2008

Cassava (Manihot esculenta Crantz) is a vitally important food source for many people in developing tropical countries. There are significant opportunities for improving the compositional qualities and pest resistance of cassava, and modern biotechnology is expected to play an important role in these improvements. The testing and development of genetically modified cassava will of course be subject to regulatory review, and experimental field trials must be performed in a fashion that prevents gene flow from the regulated plants. Methods to ensure reproductive isolation will be derived from a fundamental understanding of the biology of the crop. A current and comprehensive document on cassava reproductive biology is not yet available but is essential to guide regulators and scientists in planning and evaluating measures for reproductive isolation of confined field trials. This paper compiles a current view of the reproductive biology of cassava for use in experimental design and regulation of confined field trials. With the current state of knowledge on gene flow and seed dormancy in cassava, three methods for reproductive isolation of regulated experimental plots may currently be recommended: (i) removal of flower buds before flowering, (ii) destruction of plants before flowering, and (iii) floral bagging to contain pollen and seed. Areas for further research in cassava biology and biosafety are suggested.
Water Quality Performance of a Batch‐Type Stormwater Detention Basin
Authors: Middleton John R. , Barrett Michael E.
Published: January 2008

The objective of this research was to modify an extended detention basin to provide batch treatment of stormwater runoff. An automated valve/controller was developed and placed on the outlet of a detention basin in Austin, Texas, which allowed the water quality volume to be retained in the basin for a preset length of time. The influent and effluent of the modified basin were monitored for total suspended solids (TSS), nutrients, chemical oxygen demand (COD), and total and dissolved metals. Statistically significant removal of total metals, COD, total nitrogen, total phosphorus, and TSS was observed, with a discharge event mean TSS concentration of 7 mg/L and a TSS removal efficiency of 91%. The modified basin has substantially better pollutant removal than conventional extended detention basins and is comparable with that of Austin sand filters, which are a common structural stormwater treatment system in the Austin area. The valve also can be used to isolate hazardous material spills.
1H, 13C, 15N NMR and 13C, 15N CPMAS studies of cobalt(III)-chloride-pyridine complexes, spontaneous py → Cl substitution in trans-[Co(py)4Cl2]Cl, and a new synthesis of mer-[Co(py)3Cl3]
Authors: Pazderski Leszek , Surdykowski Andrzej , Pazderska-Szabłowicz Małgorzata , Sitkowski Jerzy , Kozerski Lech , Kamieński Bohdan , Szłyk Edward
Published: January 2008

trans-[Co(py)4Cl2]Cl·6H2O, mer-[Co(py)3Cl3] and mer-[Co(py)3(CO3)Cl] were studied by UV-Vis, far-IR and 1H, 13C, 15N NMR. The formation of Co-N bonds lead to variable in sign and magnitude changes of 1H NMR chemical shifts, heavily dependent on proton position, coordination sphere geometry and character of auxiliary ligands. 13C nuclei were deshielded upon Co(III) coordination, while 15N NMR studies exhibited ca. 85–110 ppm shielding effects (ca. 15–25 ppm more expressed for nitrogens trans to N than trans to Cl or O). 13C and 15N CPMAS spectra revealed a slight inequivalency of formally identical Co-py bonds in trans-[Co(py)4Cl2]Cl·6H2O and mer-[Co(py)3Cl3], suggesting for the latter complex an existence of distortion isomers. In chloroform, a spontaneous trans-[Co(py)4Cl2]Cl → mer-[Co(py)3Cl3] + py reaction was monitored by 1H NMR and UV-Vis. This process of py → Cl substitution allowed the design of a more convenient and efficient method of mer-[Co(py)3Cl3] preparation.
Influence of surfactants on the fading of malachite green
Authors: Raducan Adina , Olteanu Alexandra , Puiu Mihaela , Oancea Dumitru
Published: January 2008

The kinetics of the reaction between malachite green (MG) and sodium hydroxide (MG fading) was studied using a spectrophotometric method in the presence of two cationic surfactants, cetyl-benzyl-dimethyl-ammonium chloride (CBDAC) and hexadecyl-trimethylammonium bromide (HTAB) and one anionic surfactant, sodium dodecyl sulphate (SDS) at concentrations below and above critical micellar concentrations. The cationic surfactants have a catalytic effect, while the anionic surfactant has an inhibitory effect on the reaction. A kinetic model describing the influence of surfactant on reaction rate was developed. The results are discussed on the basis of electrostatic and hydrophobic interactions between the kinetic micelles and malachite green.
Oxidation of UO2(s) in aqueous solution
Authors: Roth Olivia , Jonsson Mats
Published: January 2008

In this review the kinetics and mechanism of oxidative dissolution of UO2(s), mainly under conditions of relevance for the safety assessment of a deep geological repository for spent nuclear fuel, are discussed. Rate constants for the elementary processes involved (oxidation of UO2 and dissolution of oxidized UO2) are used to calculate the rates of oxidative UO2(s) dissolution under various conditions (type of oxidant, oxidant concentration and HCO3−/CO32− concentration) for which experimental data are also available. The calculated rates are compared to the corresponding experimental values under the assumption that the experimental numbers reflect the steady-state conditions of the system. The agreement between the calculated rates and the corresponding experimental ones is very good, in particular for the higher rates. In general, the calculated rates are somewhat higher than the experimental numbers. This can be due partly to the use of initial concentrations rather than steady-state concentrations in the calculations. The kinetic data are also used to quantitatively discuss the dynamics of spent nuclear fuel dissolution under deep geological repository conditions.
Aminophosphine complex as a catalyst precursor in Suzuki coupling reactions
Authors: Zhao Dongbin , Fei Zhaofu , Ang Wee
Published: January 2008

A palladium complex with an aminophosphine ligand has been prepared and investigated as a catalyst precursor in Suzuki coupling reactions in toluene. Nanoparticles composed of elemental palladium have been isolated from the reaction media and analyzed using transmission electroscopic microscope (TEM), which shows the essential catalysts palladium nanoparticles to have a size of ca. 3.0 nm.
Microwave-induced combustion synthesis and characterization of NixCo1−xFe2O4 nanocrystals (x = 0.0, 0.4, 0.6, 0.8, 1.0)
Authors: Baykal Abdülhadi , Kasapoğlu Nermin , Köseoğlu Yüksel , Başaran Ali , Kavas Hüseyin , Toprak Muhammet
Published: January 2008

A series of Ni-doped cobalt ferrites NixCo1−xFe2O4 (x = 0.0, 0.4, 0.6, 0.8, and 1.0) were prepared using microwave-induced combustion. Nickel, cobalt, and ferric nitrates were used as starting materials and glycine as fuel. The influence of Ni content on the lattice parameter, stretching vibrations, and magnetization was studied. XRD, FTIR, and SEM were used for structure, composition, and morphology investigation. A porous network structure was observed with average particle size 60–67 nm. All samples had a cubic spinel structure. The unit cell parameter “a” decreases linearly with nickel concentration due to the smaller ionic radius of nickel. Magnetization measurements showed that coercivity decreased as Ni content increased; it increased with decreasing temperature.
Metabolic Disorders in Dairy Calves in Postpartum Period
Authors: Podhorský A. , Pechová A. , Dvořák R. , Pavlata L.
Published: January 2008

The aim of this study was, in terms of analysis of causes of disorders in calves on dairy farms, to evaluate occurrence of metabolic disorders in their postnatal period. In 23 agricultural farms (14 farms with the incidence of clinical forms of disease in calves during milk nutrition period - group D; 9 farms with no clinical disease - group H) clinical examination was performed, blood samples were collected and data concerning the provision of permanent day and night care for calves (PDC) during delivery and in early postpartum period were collected. The samples were taken from 3 - 5 calves in every farm (totally 97, H - 38, D - 59). Biochemical indicators that have some relations to the quality of colostral nutrition were determined (the concentrations of immunoglobulins - Ig, total protein - TP, albumin - A, globulins - G, vitamin E and A, the activity of gammaglutamyl transferase - GMT) and to the microelement metabolism (the activities of glutathione peroxidase - GSH-Px for evaluation of selenium (Se) status, the concentrations of copper (Cu) and zinc (Zn)). While evaluating the entire group of examined calves, we found a high occurrence of metabolic disorders in calves connected with colostral nutrition and also high occurrence of microelement deficiencies. The decrease in TP was diagnosed in 80%, the decrease in G in 78%, the decrease in concentration of Ig in 78% and 74% of calves had higher A/G ratio. Insufficient intake of colostrum showed also lower activities of GMT in 76% of calves. Hypovitaminosis E was diagnosed in 67% of calves and hypovitaminosis A in 19% of calves. Microelement deficiencies were found in 77% (Cu), 39% (Se), and 10% (Zn) of calves. While comparing the results for calves in groups H and D, in the group of calves from farms with no clinical disease (H) a significantly higher (p < 0.01) concentrations of albumin and vitamin E, as well as vitamin A (p < 0.05) were established. When comparing the farms with provided daylong care (PdC+) and with no daylong care (PdC-), in PdC+ farms calves had a significantly higher (p < 0.01) concentration of TP and G, GSH-Px activity, and also a significantly lower (p < 0.01) A/G ratio, which proves a higher-quality colostral nutrition. The results thus prove that the incidence of metabolic disorders in dairy calves in the Czech Republic represents a highly actual problem and that one of the significant factors that influence this condition is the insufficient care for and the related insufficient colostral nutrition of the calves.
Effects of Metazachlor on Vitellogenin Induction in Zebrafish (Danio rerio)
Authors: Jurčíková J. , Mikula P. , Dobšíková R. , Némethová D. , Svobodová Z.
Published: January 2008

The influence of metazachlor on vitellogenesis in juvenile (20 days old) zebrafish (Danio rerio) was investigated after ambient water exposure to concentrations of 0.1, 1.0 and 5.0 mg l-1 of the chloroacetanilide herbicide Butisan 400 SC containing approximately 35.6% (w/w) metazachlor. After 20 days of exposure, vitellogenin concentrations in whole-body homogenates of the fish were measured by direct sandwich ELISA. The results were compared to vitellogenin concentrations in fish from both negative (no exposure) and positive (exposed to natural oestrogen 17β-oestradiol) control groups. Exposure to Butisan 400 SC at a concentration of 5.0 mg l-1 induced vitellogenin synthesis significantly compared to the control fish (p < 0.05). The oestrogenic effect of 17β-oestradiol was confirmed.
Safety Impacts of Freeway Managed-Lane Strategy
Authors: Lee Jung-Taek , Dittberner Randy , Sripathi Hari
Published: January 2008

This paper presents results of a safety analysis of a freeway managed-lane strategy, that is, a time-of-day managed-lane strategy that concurrently allows use of the inner left lanes by high-occupancy vehicles (HOVs) and use of right shoulders as general purpose travel lanes during peak hours. Recent 3-year crash data and corresponding annual average daily traffic (AADT) volumes and lane-type-specific AADT volumes were identified for various lane types, including the inner left lanes for HOV only use during peak hours, general purpose lanes, right shoulder lanes, and all lanes as a whole. Negative binomial regression models were used to estimate the effect of this traffic operations system and other factors relevant to crash frequency. The negative binomial regression model analyses present no evidence that the interest factors, including the managed-lane strategy during peak hours, AADT volumes, merging and diverging influence areas, weather, light conditions, and existence of pull-off areas, affect the crash frequency when aggregated across all lanes. The variable AADT volumes in the specific analysis of general purpose lanes appear to be significant and show about a 2% increase in weekday crashes for each increase of 1,000 vehicles per day in the AADT range of 50,000 to 83,000 vehicles per day. Right shoulder specific analysis shows that motorist behaviors at the merge and diverge areas during adverse light conditions are significant and shows an increase of about 38% in crashes in these areas. The managed-lane strategy does not appear to be significant to the crash frequency in the inner left lanes for HOV, general purpose lanes, or right shoulders.
Relationship of Lane Width to Saturation Flow Rate on Urban and Suburban Signalized Intersection Approaches
Authors: Potts Ingrid B. , Ringert John F. , Bauer Karin M. , Zegeer John D. , Harwood Douglas W. , Gilmore David K.
Published: January 2008

An understanding of the relationship between lane width and traffic operations is important in making decisions about urban and suburban arterials. Numerous geometric elements, including lane width, affect the saturation flow rate at an intersection on an urban or suburban arterial. Several studies have been conducted to evaluate the relationship between lane width and saturation flow rate at intersections. This relationship is investigated on urban and suburban signalized intersection approaches by using field-study sites with the most ideal conditions possible. Research results indicate that saturation flow rate varies with lane width. Average saturation flow rate was in the range of 1,736 to 1,752 passenger cars (pc)/h/ln for 2.9-m (9.5-ft) lanes, 1,815 to 1,830 pc/h/ln for 3.3- to 3.6-m (11- to 12-ft) lanes, and 1,898 to 1,913 pc/h/ln for lane widths of 4.0 m (13 ft) or greater. These measured saturation flow rates are generally lower than those currently used in the Highway Capacity Manual (HCM). Furthermore, the percentage difference in saturation flow rate between sites with 2.9- and 3.6-m (9.5- and 12-ft) lanes was about half the value used in the HCM. Because data were limited to queue lengths between 8 and 11 vehicles, the research results do not directly address queue lengths longer than 11 vehicles.
Probabilistic Analysis of Highway Capacity Manual Models
Authors: Ji Xiaojin (Jerry) , Prevedouros Panos D.
Published: January 2008

“Uncertainty analysis” is a relatively new term in traffic capacity analysis, but it is routine in other areas of civil engineering. Three methods are proposed to examine the uncertainty of Highway Capacity Manual models caused by variance in the inputs: one-at-a-time, point estimate, and Monte Carlo simulation. These methods have different levels of computational intensity and input requirements. They are recommended for three levels of detail in probabilistic analysis, depending on the application. Correspondingly, the results of probabilistic analysis vary from simple upper and lower values to a comprehensive output with mean values, standard deviations, confidence intervals, and delay distributions. The methods were applied to a signalized intersection to demonstrate the application of the three levels of analysis. Field data were from an actuated signalized intersection in Honolulu, Hawaii. Application of the three methods is illustrated in detail. Although the probabilistic method is considered to be more robust than the existing deterministic method, the former is not recommended for application to every project. Options are given for conditions under which the probabilistic method should be applied and the appropriate level of probabilistic analysis.
Driver Behavior Model of Saturation Flow
Authors: Long Gary
Published: January 2008

Traditional estimates of saturation flow rates have been based on a hypothesis that the time headways between successive vehicles entering an intersection from a traffic signal are constant after the first three to five vehicles are discharged. This model of constant flow has been challenged by recent field observations in which average headways between vehicles continue to decrease through the last queued vehicle entering an intersection, causing a marginal saturation flow rate that increases progressively with each entering vehicle. Large variations in saturation flow measurements also have cast doubt on the presumption that the base saturation flow rate of 1,900 passenger cars per hour of green time per lane (specified in the Highway Capacity Manual) is either stable or a constant value. The human factors that underlie the rate at which successive queued vehicles enter an intersection at a traffic signal are considered. A model based on driver behavior is formulated in a manner that can be calibrated without difficult field measurements of speeds or accelerations at precise points. Along with average queue lengths and average flow speeds, only average discharge headway times by queue position are needed. The model results suggest that the saturation flow rate probably is related to two key variables ordinarily ignored: downstream cruising speed and green-phase length. If the downstream cruising speed is slow and the green phase is long, then the discharge rate might become uniform and the base saturation flow rate might be adequately represented by a constant. For other situations, results indicate that flow rates progressively increase, as found in field studies.
Poisson Multilevel Methodology of Bicycle Levels of Service for Road Networks
Authors: Zolnik Edmund J. , Cromley Ellen K.
Published: January 2008

Methodologies for bicycle levels of service have been developed for urban and suburban road segments, as well as for rural road segments. Today, however, the utilitarian (commuter) cyclist requires access to urban, suburban, and rural environs to travel safely between home and work. To complement bicycle level-of-service methodologies that incorporate mental stressors in road segments, this study developed a bicycle level-of-service methodology that incorporates physical stressors in road networks with the greatest influence on the frequency and the severity of cycling injuries from bicycle–motor vehicle collisions. To do so, the methodology integrates output from two different statistical models. To model the frequency of bicycle–motor vehicle collisions on all road segments (n = 65) in a regional road network, a Poisson model was used. To model the severity of all bicycle–motor vehicle collisions (n = 25) on the road segments in a regional road network, a multilevel model was used. To complete the Poisson multilevel bicycle level-of-service methodology, the outputs from the Poisson model of the frequency of bicycle–motor vehicle collisions and from the multilevel model of the severity of bicycle-motor vehicle collisions were used as the inputs in a geographic information system. Through analysis of the study area road network, samples of utilitarian cycling routes that minimize distance alone and that maximize safety alone were selected to quantify the benefits and the costs to utilitarian cyclists in terms of time and safety for both selections.
Bicyclist Intersection Safety Index
Authors: Carter Daniel L. , Hunter William W. , Zegeer Charles V. , Stewart J. Richard , Huang Herman
Published: January 2008

Each year many bicyclists are injured or killed in intersection-related crashes with motor vehicles. The objective of this study was to develop a macrolevel bicycle intersection safety index (Bike ISI) that would allow engineers, planners, and other practitioners to use known intersection characteristics to prioritize intersection approaches with respect to bicycle safety proactively. Using variables that indicate a higher probability of risk for bicyclists, the Bike ISI identifies which intersection approaches have the highest priority for bicycle safety improvements within a particular jurisdiction. Using video data and online ratings surveys, this study obtained data on avoidance maneuvers and safety ratings at 67 intersection approaches and developed a Bike ISI model that incorporated both measures of safety. The Bike ISI uses data on the traffic volume, the number of lanes, the speed limit, the presence of a bike lane, the presence of parking, and the presence of traffic control to give a rating for an intersection approach according to a six-point scale. Using the Bike ISI, practitioners have the ability to evaluate each approach at all intersections in their jurisdictions or at a select group of intersections. Once safety index values are assigned to each site, the practitioner can then select the sites with the highest index values and conduct more detailed reviews of those sites to determine whether any treatments are needed to improve the safety of the intersection.
Modeling of Motorcycle Ownership and Commuter Usage: A UK Study
Authors: Burge Peter , Fox James , Kouwenhoven Marco , Rohr Charlene , Wigan Marcus Ramsay
Published: January 2008

This paper presents work, undertaken for the UK Department for Transport, to help determine how policy could affect motorcycle usage. There are two important choices that determine potential motorcycle use: the decision to own a motorcycle and, contingent on that, the decision to use a motorcycle for a particular trip. This research has addressed both of these, and this paper describes the development of models that represent these decision processes. The motorcycle ownership model predicts the number of motorcycles that a person owns and the engine sizes of these motorcycles, depending on the characteristics of the person and the average purchase cost. The structure of the ownership model is a disaggregate nested logit model, with structural parameters used to measure the sensitivity of the choice of engine size relative to motorcycle ownership. Existing travel surveys contained insufficient information with which to model the mode choice decisions of motorcycle owners. Therefore, new surveys that incorporated stated preference discrete choice experiments were designed. This also allowed the collection of data to examine how motorcycle usage may change as a result of policy and the impacts of other important influences, such as weather. The data were used to develop nested logit models of mode choice. These models also give some insight into how the ability to interlane filter influences mode choice. This is the first study from the United Kingdom that models both motorcycle ownership and mode choice. It provides useful insights for policy makers and illustrates the potential for the modeling of motorcycles within the same framework used other transport modes.
Modeling Competitive Strategy Choice and Cognitive Learning Dynamics
Authors: Min Yeonjoo , Mahmassani Hani S.
Published: January 2008

Many problem contexts give rise to competitive decision situations in which players must make repeated decisions along with or in response to competitors' decisions. Choice models used in transportation generally assume that trip makers make decisions independently. Auction-based electronic marketplaces for freight service procurement are an example of such environments, and they provide the motivating application con-text for the models presented in this paper. The specific focus is on the decisions of carriers as bidders for the loads tendered by shippers in spot market situations. The paper considers the player's choice of strategy of how much to bid in an auction-based marketplace with repeated auctions involving the same set of players. A dynamic strategy choice model structure is formulated, with alternative specifications corresponding to different levels of cognition capacity. The model is intended to describe how a player or agent in a noncooperative game with no perfect information and bounded rationality chooses a bidding strategy. The paper addresses econometric issues that arise in estimating such models given a time series of auction bids and outcomes, and it formulates error structures appropriate to the highly interactive, dynamic nature of competitive auction-based marketplaces. Estimation results are presented for data obtained from hypothetical experiments designed to illustrate the model structure and alternative specifications.
Multiobjective Optimum Path Algorithm for Passenger Pretrip Planning in Multimodal Transportation Networks
Authors: Aifadopoulou Georgia , Ziliaskopoulos Athanasios , Chrisohoou Evangelia
Published: January 2008

This paper aims to present a multiobjective optimum path algorithm for passenger pretrip planning in multimodal transportation networks. The process of identifying the feasible paths accounts for the delays caused by the different modes and the terminal switching. This algorithm is designed to constitute a component of an integrated web-based information gateway, aiming to provide information to travelers through the Internet for intercity trips using public transport. The algorithm identifies feasible paths according to compatibility of various modes, intermodal stations, and users' preferences. The multiobjective linear programming model that corresponds to this process is presented to prove the efficiency of the algorithm. An implementation for the proposed algorithm is designed, coded, and computationally tested in realistic-size networks. The computational complexity of the algorithm is proven to be polynomial.
Exploring Market Support for New Products and Services for Transit and Walking
Authors: Karash Karla H. , Coogan Matthew A. , Adler Thomas
Published: January 2008

This paper concerns the relationship between mobility products and services and the propensity to change travel behavior. In an online panel survey, 501 respondents answered questions about their attitudes toward increasing their use of transit and walking. The questions first established base conditions for variables specified by the theory of planned behavior. Respondents were then exposed to seven products and services. A follow-up set of questions revealed shifts in key attitudes. New products and services may influence the traveler's personal inclination to change modal behavior, belief that a change in modal behavior might be socially acceptable, and belief or self-confidence that he or she can change modal behavior. These three attitudinal categories were examined for four market segments, two more positive and two more negative. The positive segments included the transit loyalists, who were already heavy users of transit, and the environmental mode changers, who were not heavy transit users but who wanted to help the environment. Both positive segments significantly shifted their ratings of the social acceptability of transit with the improvements. However, the segments differed in terms of what factors were associated with the improved social acceptability. For the environmental mode changers, the strongest association was with concern about being lost or stranded on public transportation, whereas for the transit loyalists, the strongest association was with being able to depend on public transportation to be timely. However, it is unclear from this research which products and services contribute to improved social acceptability.
Influence of area, habitat and water chemistry on richness and composition of macrophyte assemblages in southern Brazilian wetlands
Authors: Rolon Ana S. , Lacerda Taís , Maltchik Leonardo , Guadagnin Demétrio L.
Published: January 2008

Questions: Two hypotheses were tested: (1) physical features, such as wetland surface area and habitat diversity, together with water chemistry, are important determinants of species richness and composition of macrophyte assemblages and (2) species richness and composition of macrophyte assemblages differ between wetlands of different types (i.e., palustrine versus lacustrine) and between wetlands of different hydrologies (i.e. permanent versus intermittent).

Location: A subtropical coastal plain segment (2500 km2) of southern Brazil.

Methods: Quarterly collections were carried out in 15 wetlands (2004–2005) in southern Brazil. Differences in richness over time were tested using repeated measures ANOVA. Stepwise multiple regression was performed to investigate relationships between total richness and environmental variables. Significance of differences between wetland types and hydroperiods on species composition was verified by MRPP (Multi‐Response Permutation Procedure). The influence of the environmental variables on species composition was assessed using CCA (Canonical Correspondence Analysis).

Results: Macrophyte species richness changed with time, was not significantly different between wetland types, but was higher in permanent wetlands than in intermittent ones. Area, habitat diversity and soluble reactive phosphorus concentration explained 76% of the variation in species richness. Species composition was different between permanent and intermittent wetlands, although it was not significantly different between wetland types. Area, habitat diversity and water chemistry explained 50.1% of species composition.

Conclusions: Species richness and composition of wetland macrophytes were mainly determined by area, habitat diversity and hydroperiod. These results can be used for the development of conservation and management programs in southern Brazil.
Species‐specific responses of an alpine plant community under simulated environmental change
Authors: Klanderud Kari
Published: January 2008

Question:

How will warming and increased nutrient availability affect individual alpine plant species abundances (non‐vascular and vascular) and community composition?

Location:

Dryas octopetala heath at alpine Finse, southern Norway.

Methods:

Four years with experimental warming (open top chambers) and nutrient addition. Detrended Correspondence Analysis and Redundancy Analysis were used to examine changes in community composition. GLM‐ANOVA was used to examine treatment effects on individual species.

Results:

Warming alone decreased the abundance of some Carex and bryophyte species, but did not affect community composition. Nutrient addition and warming combined with nutrient addition increased the abundance of high stature species, such as grasses (Festuca spp., Poa alpina) and some forbs (e.g. Cerastium alpinum, Potentilla crantzii). Low stature forbs (e.g. Tofieldia pusilla), a lycophyte (Selaginella selaginoides) and most bryophytes and lichens decreased in abundance. After four years of warming combined with nutrient addition 57% of the mosses, 57% of the liverworts and 44% of the lichens had completely disappeared. Community composition changed significantly, with the largest shift when warming and nutrient addition was combined.

Conclusions:

Tall species may expand at the expense of low stature species in the alpine region if temperature and soil nutrient content increase. Contrasting responses between grasses and sedges, and species‐specific responses within forbs, sedges and shrubs, within and across alpine and arctic sites, suggest that the use of functional types in environmental change research may mask important information on individual species responses. The response of one species within a functional type cannot predict the response of another.
ADMEProperties of Drugs
Authors: Di Li , Kerns Edward H.
Published: January 2008

ADME properties have tremendous impact on the success of drug candidates. They are a set of fundamental physico‐chemical and biochemical properties of drug molecules that can be affected by physiologic conditionsin vivo: solubility, permeability, stability, metabolism, and others. ADME properties can be improved through structural modification by medicinal chemists. They are important bothin vitroandin vivo. A successful drug must possess a balance of good potency and drug‐like properties. High‐throughput ADME assays have been developed and implemented widely in the pharmaceutical industry to reduce the attrition of drug candidates. The data are used to identify potential liabilities, guide structural modification, prioritize lead series, select compounds forin vivostudies, and diagnosein vivoassay results. Studies have demonstrated that early screening of ADME properties is a successful approach to enhance the quality of drug candidates.
Alkaloid Biosynthesis
Authors: O'Connor Sarah E.
Published: January 2008

How nature synthesizes complex secondary metabolites, or natural products, can be studied only by working within the disciplines of both chemistry and biology. Alkaloids are a complex group of natural products with diverse mechanisms of biosynthesis. This article highlights the biosynthesis of four major classes of plant‐derived alkaloids. Only plant alkaloids for which significant genetic information has been obtained were chosen for review. Isoquinoline alkaloid, terpenoid indole alkaloid, tropane alkaloid, and purine alkaloid biosynthesis are described here. The article is intended to provide an overview of the basic mechanism of biosynthesis for selected members of each pathway. Manipulation of these pathways by metabolic engineering is highlighted also.
Progress in Nanoengineered Microstructures for Tunable High‐Current, High‐Temperature Superconducting Wires
Authors: Holesinger T. G. , Civale L. , Maiorov B. , Feldmann D. M. , Coulter J. Y. , Miller D. J. , Maroni V. A. , Chen Z. , Larbalestier D. C. , Feenstra R. , Li X. , Huang Y. , Kodenkandath T. , Zhang W. , Rupich M. W. , Malozemoff A. P.
Published: January 2008

High critical current densities (Jc) in thick films of the Y1Ba2Cu3O7–δ (YBCO, Tc ≈ 92 K) superconductor directly depend upon the types of nanoscale defects and their densities within the films. A major challenge for developing a viable wire technology is to introduce nanoscale defect structures into the YBCO grains of the thick film suitable for flux pinning and the tailoring of the superconducting properties to specific, application‐dependent, temperature and magnetic field conditions. Concurrently, the YBCO film needs to be integrated into a macroscopically defect‐free conductor in which the grain‐to‐grain connectivity maintains levels of inter‐grain Jc that are comparable to the intra‐grain Jc. That is, high critical current (Ic) YBCO coated conductors must contain engineered inhomogeneities on the nanoscale, while being homogeneous on the macroscale. An analysis is presented of the advances in high‐performance YBCO coated‐conductors using chemical solution deposition (CSD) based on metal trifluoroacetates and the subsequent processing to nano‐engineer the microstructure for tuneable superconducting wires. Multi‐scale structural, chemical, and electrical investigations of the CSD film processes, thick film development, key microstructural features, and wire properties are presented. Prospects for further development of much higher Ic wires for large‐scale, commercial application are discussed within the context of these recent advances.
Scope and Applications of Amphiphilic Alkyl‐ and Lipopeptides
Authors: Cavalli S. , Kros A.
Published: January 2008

Nowadays oligopeptides can be easily synthesized and their secondary and tertiary structure is controlled by the amino acid sequence. Alkylation or lipidation of the hydrophilic peptides adds additional amphiphilicity which can be used in several applications. Examples are given of bioactive compounds (e.g., targeted drug delivery) and the self‐assembly into well‐defined surfaces able to act as templates for biomineralization is discussed.
Child age influence on the seasonal death risk during the first year of life (Spain, 1975–1989)
Authors: Luna Francisco , Alonso Verónica , Fuster Vicente , Edo Miguel A.
Published: January 2008

Infant mortality rate reflects a population's health status, which depends on several factors, such as diseases, environment, child development, and other population characteristics that can show seasonal change throughout the year. This article deals with the relevance of child age on the probability of death in the different seasons throughout the first year of life, taking into account the illnesses causing death. The study was carried out using a file from the Spanish National Institute of Statistics. To eliminate bias related to health improvement, only the 49,761 urban deaths corresponding to capital of provinces, taking place between 1975 and 1989, were considered. The variables analyzed were: the month in which death took place, disease causing death, and the child age at death. Since many causes of death are very infrequent, the analysis was limited to a selection of the most common 45,155 death cases. The causes of death analyzed were: digestive, nervous and sensory, circulatory, and respiratory diseases, delivery difficulties, congenital anomalies, and signs and syndromes (WHO, ICD‐9). The infant mortality rates are associated with the child age at death. Moreover, a general ontogenetic change of the death risk can be observed, with some particularities depending on the disease analyzed. In general, regarding all infant deaths, the obtained results suggest a higher risk of dying in winter for children surviving the first month of life, whereas a summer pattern, with a maximum mortality in June, July, and August, appeared when newborns younger than 1 week were considered. Am. J. Hum. Biol., 2008. © 2008 Wiley‐Liss, Inc.
Genetic structure of Mexican Mestizo women with breast cancer based on three STR loci
Authors: Calderón‐Garcidueñas Ana L. , Rivera‐Prieto Roxana A. , Ortíz‐Lopez Rocio , Rivas Fernando , Barrera‐Saldaña Hugo A. , Peñaloza‐Espinosa Rosenda I. , Cerda‐Flores Ricardo M.
Published: January 2008

The aim of this population genetics study was to compare the genetic structure of Mexican women with breast cancer (BrCa) with previously reported data of four random populations (Nuevo León, Hispanics, Chihuahua, and Central Region of Mexico). A sample of 115 unrelated women with BrCa and whose four grandparents were born in five zones of Mexico were interviewed at a reference hospital in Northeastern Mexico. Noncodifying STRs D7S820, D13S317, and D16S39 were analyzed; genotype distribution was in agreement with Hardy–Weinberg expectations for all three markers. Similar allele frequencies among four random populations and this selected population were found. According with this and previous studies using molecular and nonmolecular nuclear DNA markers not associated with any disease, Mexican Mestizo population is genetically homogeneous and therefore, genetic causes of BrCa are less heterogeneous, simplifying genetic epidemiologic studies. Am. J. Hum. Biol., 2008. © 2008 Wiley‐Liss, Inc.