bluuebunny/crossref_metadata_2025 huggingface dataset:
Optimal headways for multiroute transit systems
Authors: Banks James H.
Published: January 2010

The problem considered is that of determining net‐benefit maximizing headways for multiroute transit systems which are subject to constraints on vehicle capacity, subsidy, and fleet size. Route demands are assumed to be independent of one another and to vary with the frequency of service, but details of route demand functions are assumed to be unknown. Conditions of optimality are derived for the unconstrained case and the various constrained cases. The relationship between conditions of optimality based on the assumption of fixed demand and those based on the assumption of variable demand is expressed by means of terms incorporating the elasticity of demand with respect to frequency of service. It is shown that the magnitude of discrepancies between the true conditions of optimality and fixed‐demand approximations of them depends on the elasticity of demand and on the distribution of ridership and cycle times among the various routes of the system. It is also shown that a trial‐and‐error search procedure based on fixed‐demand approximations should eventually converge to a stable schedule, although its use is not appropriate for all situations in which rescheduling might be considered. A case study is presented in which the maximum possible discrepancies between the variable‐demand and fixed‐demand conditions of optimality are found to be reasonable small, and an actual transit schedule is found to be generally similar to one indicated as optimal by the fixed‐demand approximation.
An empirical analysis of selected transit systems in Texas
Authors: Sen Lalita , Radhakrishna Atur
Published: January 2010

Transit systems are directly affected by decisions made by the management and policy makers. The policy makers at the federal and especially at the state and local levels play key roles with respect to disbursement and collection of local and other sources of transit revenue. Using fifteen cities in Texas, the authors here analyzed the utility of the existing secondary data source, the section 15 report. It is intended that this research will provide policy makers with procedures for comparative analysis upon which to formulate transit policies at various levels of government.
An intercity model of modal split considering four modes
Authors: Lyles Richard W. , Mallick Sayeedur R.
Published: January 2010

The consideration of a new mode of intercity travel, such as high‐speed rail passenger service, immediately raises the question of whether the demand meets the criteria for economic feasibility. Before the demand issue can be addressed however, an understanding of the mechanism of an intercity traveller's decision about how to travel must be gained. In the reported study, four different modes for intercity travel are explicitly considered: bus, private automobile, commercial air service, and conventional rail service. In addition, several structurally different disaggregate models for mode choice decisions are considered. The models which are developed suggest that decisions should probably be viewed as being sequential (versus simultaneous) and largely based on the perceptions of the travel services provided. The characteristics of the traveller (including trip purpose) appear to be collectively more important than measurable characteristics of the mode alternatives. In general, the modeling effort was successful with relatively reliable models being developed. The information that results from such an effort is useful to both those who are interested in predicting modal choice from a facility planning perspective as well as those interested in marketing (or at least assessing the demand for) new intercity modes. In the end, however, the implication regarding the capability of high‐speed rail to effectively compete with other modes is that it has yet to be proven—this work suggests that it will not.
Airport people movers: Reaching outside the fence
Authors: Fabian Lawrence J.
Published: January 2010

There is intensifying need to rationalize the growth and operation of expanding airports and the “airport city” around them. The provision of people mover systems at airports has grown into a mature and increasingly competitive industry. These automated train systems have revolutionized the way major airports are planned. Terminal, parking, and auxiliary facilities can be spread out to provide maneuvering room for aircraft and ground equipment, with walking distances overcome by efficient, reliable people mover service. This paper argues that the success at handling airport circulation should be extended outside the airport fence to serve parking intercepts, regional transit, and many of the facilities which increasingly cluster around airports.
Use of CAD systems in airport engineering
Authors: Shen Lon‐Li David
Published: January 2010

Most major airports in the United States will undergo major improvement and expansion projects to accommodate the increasing demands in the coming decade. Use of Computer Aided Design (CAD) systems allows the design engineer to produce numerous drawings quickly and accurately during the planning and design phase. In addition, use of CAD systems frees engineers to do what they do best: plan, design, construct. Actual and potential applications of CAD systems are shown. It is concluded that most of the airport planning and design projects in the United States will be done on CAD systems by the end of this decade.
Growth of urban transportation: Peoples republic of China
Authors: Zhao‐Sheng Yang , Paaswell Robert E. , Rouphail Nagui M.
Published: January 2010

The Peoples Republic of China, with its great urban populations, is finding it necessary to develop a range of strategies to deal with increasing demand for goods and people movement, increasing motorization and the increasing congestion that results from the increasing travel demand. This paper discusses strategies being adopted in two northern cities, Changchun and Shenyang. Both transit and roadway programs are examined for Changchun. Problems and successes of a new toll road are examined for Shenyang. Sustained infrastructure investment is essential to assure the necessary mobility for economic growth.
Effect of time‐value distributions on transit headway optimizations
Authors: Banks James H.
Published: January 2010

The issue considered is whether the biases that result from assuming a single value of waiting time in variable‐demand headway optimizations (and the demand models on which they are based) can have a significant impact on the results of the optimization. Marginal benefit functions based on binary probit demand models, and incorporating the alternative assumptions of either a single value of time, a discrete distribution of time values, or a continuous distribution of time values, are derived and compared for several cases. These comparisons indicate the possibility of significant errors in several cases, the most realistic of which is that of a highly heterogeneous market composed of a large segment of “choice riders” and a smaller segment of “transit captives”.
A simulation model of train travel on a rail transit line
Authors: Kikuchi Shinya
Published: January 2010

A simplified simulation model for the operational analysis of a rail rapid transit train is presented. The model simulates the movement of a train along a route, and develops the relationships of time—distance, time—speed and distance—speed. The inputs to the model are the profile of speed limits and the dynamic characteristics of the train. Without the information on the track geometry and tractive effort, the model determines the speed of the train at a location based on the previous and future speed limits relative to the location. It was found that the model can fairly accurately simulate the relationship between travel time and distance. A comparison of the train travel times between the actual and simulated runs is presented. Because of the simplicity of input and calculation method, the model can be a useful tool for the “desk‐top” analysis of frequently occurring planning problems of a commuter rail or rail rapid transit line, such as the impacts of changes in speed limits, station locations, station stopping policy, addition/elimination of stations, and types of rail cars.
Designing personal rapid transit (PRT) networks
Authors: Ma Jun , Schneider J. B.
Published: January 2010

This paper presents a heuristic method for designing a PRT network. Because the PRT system operating characteristics and performance measures differ widely from those of conventional transit technologies, an algorithm for the PRT network design problem (NDP) is derived by using concepts from some current NDP algorithms. We minimize the sum of passenger travel time cost, construction cost, vehicle cost and operational costs, subject to an available budget of guideway, a maximum number of vehicles and given link capacities. Starting with a well‐connected initial network, the algorithm eliminates and adds links iteratively as it searches for a near‐optimal solution. If this solution satisfies the budget constraint, it is considered to be acceptable. Otherwise, additional links are deleted until a feasible near‐optimal solution is obtained. The link elimination phase of the algorithm only considers half of the links at a time which greatly decreases computing time. None of the links in an acceptable solution will be overloaded.
Optimal slack time for timed transfers at a transit terminal
Authors: Lee Kurt K. T. , Schonfeld Paul
Published: January 2010

At transit terminals where two routes interchange passengers, total system costs may be reduced by allowing some “slack” time in the vehicle schedules to decrease the probability of missed connections. Transfer cost functions are formulated and used to determine optimal slack time for simple systems with transfers between one bus route and one rail line. Some analytic results are derived for empirical discrete and Gumbel distributions of bus arrival times. Relations between the optimal slack times and headways, transfer volumes, passenger time values, bus operating costs, and standard deviations of bus and train arrivals are also developed numerically using normally distributed arrivals. However, the proposed numerical approach can optimize slack times for any observed arrival distributions. The results provide some guidelines on desirable slack times and show that schedule coordination between the two routes is not worth attempting when standard deviations of arrivals exceed certain levels. Possible extensions of this work are suggested in the last section.
A pre‐appraisal model for rail transit in developing cities
Authors: Bamford T. J. G. , Allport R. J.
Published: January 2010

A major research study funded by the UK Overseas Development Administration (ODA) and designed to establish the necessary considerations for viability of mass rapid transit railways in developing cities was recently completed. The analytical core of the study was a pre‐appraisal model, which combines an innovative strategic land use/transport model utilizing relationships from developing cities and an economic evaluation model. This model — MRTAP — has now been developed into a user‐friendly package which the ODA intend should be made widely available in the developing world. The paper describes the basis of this model.
Aircraft and maintenance scheduling support, mathematical insights and a proposed interactive system
Authors: Biró M. , Simon I. , Tánczos C.
Published: January 2010

In this paper we first review the current practice of operative aircraft and maintenance scheduling at the Hungarian Airlines. The ideas to be included in the proposed operative scheduling support system mean new contributions from both the algorithmic and human‐computer interaction points of view. The algorithm is based on new graph theoretical results which were motivated by the necessity of combining a given flight schedule with the strict maintenance requirements of the aircraft. Aircraft rotation corresponds in mathematical terms to the coloring of an interval graph with colors representing the tail numbers in such a way that the vertices corresponding to maintenance checks are colored in advance. The human‐computer interface is built on the Microsoft Windows graphics environment, which allows a simultaneous, visual and active contact with all necessary information and methods.
Dependability as a measure of on‐time performance of personal rapid transit systems
Authors: Anderson J. Edward
Published: January 2010

A comprehensive method for calculating and measuring Dependability of Personal Rapid Transit systems is derived and compared with the more common measure called Availability. Availability is the percentage of all revenue trips that are completed without interruption. It does not take into account the duration of delays of the passengers because of the diffiiculty of gathering the necessary information in conventional transit systems. In PRT systems, vehicle‐hours of travel and of delay relate in a statistically simple way to person‐hours of travel and of delay. Therefore, in such systems, it is practical to use the performance measure called Dependability that takes into account the inconveince of people as a result of delays. To form a bridge to present practice, it is recommended that both measures be calculated and compared in forthcoming PRT systems. With today's computer systems, this is easily accomplished.
Evaluation of truck configurations based on structural performance of bridges
Authors: Fu C. C. , Schelling David R. , Ayyub Bilal M.
Published: January 2010

Contained herein are the results of research which quantifies the effects that various existing and projected truck configurations have as live loadings upon bridges which currently exist on the National Bridge Inventory (NBI). The truck configurations were determined from those actual or proposed vehicles which exhibit the highest GVW and which either are causing or are perceived to cause the highest levels of overstress on bridge superstructure elements.

In order to simulate most accurately the actual field conditions, a criterion was defined which contained three major requirements: 1) The bridges utilized within the study shall be defined as being a statistically significant sample and be actual bridges taken from the NBI; 2) The analysis method shall be consistent with those actually used by engineers in designing and rating bridges, and; 3) The criteria utilized in evaluating the various bridge structures under the defined loadings shall be consistent with current practices.

The results obtained indicates the acceptability of various truck configurations by GVW, size, and axle deployments, by system for the different criteria now in use.
Multiobjective pricing of bus‐subway services in Santiago, Chile
Authors: Jara‐Díaz Sergio R. , Tudela Alejandro M.
Published: January 2010

Presently, the surface transit system in Santiago, Chile is private and atomized. It operates in competition with the subway, covering long distances and causing congestion in the central business district. As the subway operates below capacity, integrated services with a common fare have been identified as both operatively and financially possible, making better use of resources and avoiding negative externalities. A multi‐objective approach is formulated and applied to determine the price of the combined service, accounting for both users' benefits and operators' profit. The role of different parameters in the financial and operative constraints is analyzed in particular, as well as the conflicting nature of the objective functions. The non‐inferior set of solutions is constructed and analyzed both in the decision variables space and in the objectives space, and solutions are compared against the present conditions.
A study on adjustment factors for U‐turns in left‐turn lanes at signalized intersections
Authors: Tsao Shou‐Min , Chu Song‐Wei
Published: January 2010

U‐turns are treated as left‐turns in the current procedures for estimating saturation flow rates at signalized intersections. While U‐turning vehicles are usually mixed with left‐turning vehicles in inside or left‐turn lanes and conflict with opposing through traffic as left‐turning vehicles, the vehicle operating characteristics are different. The objective of this paper is to investigate the effects of U‐turns on the traffic flow in left‐turn lanes.

Field data of 600 headways of left‐turning passenger cars and 160 headways of U‐turning passenger cars are recorded. The average headways of U‐turning passenger cars are found to be significantly larger than those of left‐turning passenger cars. The effects of U‐turning vehicles depend upon the percent of U‐turning vehicles in the left‐turn lane, as well as the order of formation in the traffic stream. Adjustment factors for varying percents of U‐turning vehicles in left‐turn lanes are established.
Involving citizens in sustainable development: Scenario workshop on sustainable mobility
Authors: Nielsen Lise Drewes , Hansen Leif Gjesing
Published: January 2010

The scenario workshop is an example of the Scandinavian tradition of citizen involvement. The method is a mix of scenario and workshop. Scenarios produced by experts (scientists) are presented to a local community in a workshop lasting two to three days during which local participants produce criticism, debate and plans for community action. The method, originally used to actively involve citizens in the development of environmentally sustainable cities in Denmark, is now in use throughout Europe, as the various EU directorates have become very aware of their usefulness. A method has now been generated at the Copenhagen Business School for the field of transport. Four transport scenarios were generated relating to post‐Fordist production systems, transport and the concept of sustainable mobility. They are to be presented in a transport‐intensive region of Denmark to analyse barriers against environmentally induced adjustments to the transport sector and to find new solutions to the dilemma by creating dialogue between planners, politicians and transport managers.
A fuzzy measure based solution approach to a multimodal analysis problem
Authors: Dhingra S. L. , Ramanajee M.
Published: January 2010

This paper discusses the factors that determine the utility of a mode and attempts to suggest and investigate a novel fuzzy measure based solution approach to the problem of multimodal analysis in a multicriteria context. The paper expands on the notions of fuzzy logic and in particular, fuzzy measures. The approach attempts to estimate the probabilities of the “overall system” from a group of eight experts who are experienced in transport planning. The data is used to ascertain the relative utility of various modes in a competitive environment. It explains the application of fuzzy measures to provide guidance information for a transport planning agency.
Citizen involvement in the transportation planning process: What is and what ought to be
Authors: Khisty C. Jotin
Published: January 2010

Public involvement in the transportation planning process is an effort to ensure that citizens have a direct voice in public decision‐making. Through shared goals, such involvement enriches the planning, implementation, operation and management process. Various strategies of involving the public in the planning process have been tried in the past thirty years, but the overall effort has been lumpy and at times disappointing. In the last few years some forms of communicative action have been applied, following its appearance in current literature, but we still have a long way to go. This paper has four main objectives. First, it surveys the citizen involvement effort as it is practiced today and the problems it faces. Second, it describes teleogenic systems that are particularly suited for tackling conflictual problems. Thirdly, it presents the interplay of virtuous and vicious cycles in reinforcing or retarding collective decision making. And lastly, the process of harvesting the potential of citizen groups in collective decision‐making through critical systems thinking is described.
The impact of job assignment rules for straddle carriers on the throughput of container terminals
Authors: Behera J. M. , Diamond N. T. , Bhuta C. J. , Thorpe G. R.
Published: January 2010

Straddle carriers represent a critical resource in the handling of containers within a container terminal. It is essential that they are deployed in an as efficient manner as possible. The research presented in this paper is motivated by the need to critically evaluate job assignment rules for straddle carriers that operate in a multiple straddle environment. This is achieved by developing a discrete event simulation model using industrial simulation software to model a container terminal located in Melbourne, Australia. The model accounts for variables such as the number of straddle carriers needed, the speed of straddle carriers, the arrival rate of trucks, and the job assignment rule. A principal finding of the study is that increasing the number of straddles in the present set‐up from 6 to 7 has a negligible effect on daily throughput. However, an increase in the number of straddles to 7 is expected to have a profound effect on reducing the average waiting time of trucks within the terminal from over 16 minutes to under 9 minutes, a decrease of 46.5%. However, a further increase in the number of straddles results in no further increase in daily throughput. It was observed that the throughput of the terminal is very sensitive to the speeds at which straddles travel.

The management of the terminal has proposed a new heuristic job assignment rule for straddles, because the present rule does not assign the jobs to straddles closest to the truck requesting to load or unload a container. As a result a new heuristic job assignment rule was tested. The simulation results revealed that both the old and new rules performed equally well using performance indicators such as average container flow time, daily throughput, average waiting time of jobs, number of jobs in the queue, and straddle utilisation. Therefore, the new rule will not improve these performance measures if implemented
The car pooling problem: Heuristic algorithms based on savings functions
Authors: Ferrari Emilio , Manzini Riccardo , Pareschi Arrigo , Persona Alessandro , Regattieri Alberto
Published: January 2010

The present research deals with car pooling as a means of making better use of existing infrastructure and as a means of reducing traffic congestion with all its associated induced effects. Car pooling schemes involve several drivers getting together to share a private vehicle simultaneously, in order to reach their destinations points according to a semi‐common route rather than each driver using their own vehicle. The Car Pooling Problem belongs to the non‐polynomial computational complexity family of operations problems. In the current literature there are only a few studies on this optimization problem: the research group has designed several different new automatic and heuristic data processing routines to support efficient matching in car pool schemes. These are based on savings functions and belong to two distinct macro classes of algorithms to give two different modelings of this problem. They offer average savings of more than 50% in traveled distances demonstrating the effectiveness of a trivial matching scheme for real applications.
Value of leisure time based on individuals' mode choice behavior
Authors: Shiaw Ming‐Shong
Published: January 2010

Values of time have been defined in various forms such as value of leisure time (shadow price of time), value of travel time, and value of saving time, and are mostly measured based on individuals' travel choice behavior. The main purpose of this study is to estimate the value of leisure time by general mode choice models. The estimated level can be used to evaluate the benefits from the increasing leisure time gained by people in Taiwan after the government has practiced a series of policies to shorten employee's working hours in the last few years. To justify the application, this study reviews and reinterprets the theoretical results of some major works on value of time derivations. Then to practically estimate the value of leisure time, it suggests a method of combining revealed preference and stated preference data for application. Finally, it conducts an empirical study on travelers' mode choices behavior in Taiwan to carry out the method suggested. The value of leisure time is estimated at 56NT$ per hour (around 1.65US$/hr), which is even lower than the minimum wage rate regulated by Taiwan government.
Sequential optimization approach for the multi‐class user equilibrium problem in a continuous transportation system
Authors: Ho H. W. , Wong S. C. , Loo Becky P. Y.
Published: January 2010

We consider a city region with several facilities that are competing for customers of different classes. Within the city region, the road network is dense, and can be represented as a continuum. Customers are continuously distributed over space, and they choose a facility by considering both the transportation cost and market externalities. More importantly, the model takes into account the different transportation cost functions and market externalities to which different customer classes are subjected. A logit‐type distribution of demand is specified to model the decision‐making process of users' facility choice. We develop a sequential optimization approach to decompose the complex multi‐class and multi‐facility problem into a series of smaller single‐class and single‐facility sub‐problems. An efficient solution algorithm is then proposed to solve the resultant problem. A numerical example is given to demonstrate the effectiveness and potential applicability of the proposed methodology.
A fraction of unripe kiwi fruit extract regulates adipocyte differentiation and function in 3T3‐L1 cells
Authors: Abe Daigo , Saito Takeshi , Kubo Yasutaka , Nakamura Yoshimasa , Sekiya Keizo
Published: January 2010

Adipocyte dysfunction is strongly associated with the development of insulin resistance and diabetes, and regulation of adipogenesis is important in prevention of diabetes. We prepared a 100% methanol fraction of methanolic extract from unripe kiwi fruit (Actinidia deliciosa), designated KMF (kiwi fruit methanol fraction). When applied to 3T3‐L1 preadipocyte cells, KMF promoted adipocyte differentiation, increased glycerol‐3‐phosphate dehydrogenase (GPDH) activity, and increased triglyceride (TG) content. KMF markedly increased mRNA expression of peroxisome proliferator‐activated receptor γ (PPARγ)—the master adipogenic transcription factor—and its target genes. Moreover, KMF increased mRNA expression and protein secretion of adiponectin, whereas mRNA expression and secretion of monocyte chemoattractant protein‐1 (MCP‐1) and interleukin‐6 (IL‐6) were decreased. Compared with troglitazone, KMF decreased the production of reactive oxygen species (ROS) and nuclear factor‐kappaB (NFκB) activation. Glucose uptake was stimulated by KMF in differentiated 3T3‐L1 adipocytes. Taken together, these results indicate that KMF may exert beneficial effects against diabetes via its ability to regulate adipocyte differentiation and function.
Impact of portal vein embolization on long-term survival of patients with primarily unresectable colorectal liver metastases
Authors: Wicherts D A , de Haas R J , Andreani P , Sotirov D , Salloum C , Castaing D , Adam R , Azoulay D
Published: January 2010

Background

Portal vein embolization (PVE) increases the resectability of initially unresectable colorectal liver metastases (CLM). This study evaluated long-term survival in patients with CLM who underwent hepatectomy following PVE.

Methods

In a retrospective analysis patients treated by PVE before major hepatectomy were compared with those who did not have PVE, and with those who had PVE without resection.

Results

Of 364 patients who underwent hepatectomy, 67 had PVE beforehand and 297 did not. Those who had PVE more often had more than three liver metastases (68 versus 40·9 per cent; P < 0·001) that were more frequently bilobar (78 versus 55·2 per cent; P < 0·001), and a higher proportion underwent extended hepatectomy (63 versus 18·1 per cent; P < 0·001). Postoperative morbidity rates were 55 and 41·1 per cent respectively (P = 0·035), and overall 3-year survival rates were 44 and 61·0 per cent (P = 0·001). Thirty-two other patients who were treated by PVE but did not undergo resection all died within 3 years.

Conclusion

PVE increased the resectability rate of initially unresectable CLM. Among patients who had PVE, long-term survival was better in those who had resection than in those who did not. PVE is of importance in the multimodal treatment of advanced CLM.
Protective effects of antioxidant combination against D‐galactosamine‐induced kidney injury in rats
Authors: Catal Tunc , Sacan Ozlem , Yanardag Refiye , Bolkent Sehnaz
Published: January 2010

The protective effects of an antioxidant combination in kidney injury induced by the injection of D‐galactosamine (D‐GaIN) were examined in the present study. Sprague Dawley female rats were used and divided into four groups as follows: (1) animals injected physiological saline solution, intraperitoneally, (2) animals treated with the combination of ascorbic acid (100 mg kg−1 day−1), β‐carotene (15 mg kg−1 day−1), α‐tocopherol (100 mg kg−1 day−1), and sodium selenate (0.2 mg kg−1 day−1) for three days orally, (3) rats injected D‐GaIN (500 mg kg−1) intraperitoneally as a single dose, and (4) animals treated with the antioxidant combination for three days, then injected D‐GaIN. The tissue and blood samples of animals were collected for morphological and biochemical evaluations. Histopathological injury in kidney tissues was observed together with a significant increase in tissue lipid peroxidation (LPO) level, myeloperoxidase (MPO), lactate dehydrogenase, catalase and superoxide dismutase (SOD) activities, and serum creatinine and urea levels, and a significant decrease in glutathione level and glutathione peroxidase activity in D‐GaIN injected rats. However, a decrease in the degenerative changes was detected in the kidney tissue of D‐GaIN + antioxidant group, and biochemical results showed reversed effects. In conclusion, it seems reasonable to conclude that the treatment of the antioxidant combination has a protective effect on D‐GaIN‐induced kidney injury of rats. Copyright © 2010 John Wiley & Sons, Ltd.
Erythroid 5‐aminolevulinate synthase mediates the upregulation of membrane band 3 protein expression by iron
Authors: Huang Qianchuan , Li Jinying , Feng Weihua , Xu Yanqun , Huang Zhenxia , Lv Shuqing , Zhou Hong , Gao Lei
Published: January 2010

Iron deficiency leads to abnormal expression and function of band 3 protein in erythrocytes, but the underlying mechanisms remain elusive. The mRNA of erythroid‐specific 5‐aminolevulinate synthase (eALAS) contains an iron response element and the eALAS protein is an important mediator of iron utilization by erythrocytes. In this study, we investigated the effect of short hairpin RNA (shRNA) mediated silencing of eALAS on the expression of band 3 protein induced by iron. By real‐time RT‐PCR and Western blot we showed that at mRNA and protein level iron‐induced expression of band 3 protein was lower in eALAS‐shRNA transfected K562 cells than in control cells. Of note, the lowest expression was detected in K562 cells cultured in iron deficiency condition (p < 0.01). Thus either iron deficiency or depletion of eALAS could suppress the expression of erythroid band 3 protein. These results demonstrated for the first time that iron and the iron‐regulatory system regulate the expression of the erythrocyte membrane proteins. Copyright © 2010 John Wiley & Sons, Ltd.
Environmentally Benign Urea‐modifed Triticum aestivum Biomass for Lead (II) Elimination from Aqueous Solutions
Authors: Farooq Umar , Khan Misbahul Ain , Athar Makshoof , Sakina Mehnaz , Ahmad Muhammad
Published: January 2010

Lead is among the three most toxic heavy metal ions (mercury, lead and cadmium). A number of methods are in use for the treatment of lead contaminated waters. The materials used for these are too expensive to be economical for lower concentrations of lead. Raw biological materials have been investigated as alternates. They can be chemically modified or pretreated in an attempt to increase their metal capturing capacities. A new material has been prepared from widely available wheat straw (WS) and urea using microwave radiation and its biosorptive behavior for lead ions has been studied. Modified wheat straw (MWS) was subjected to aqueous lead ions to optimize parameters like pH, contact time, MWS dose and temperature. A known amount of MWS was put in contact with certain concentrations of Pb (II) ions at specified temperatures and pH for certain periods of time. Time of contact, pH, dose and temperature were optimized. The sorption of lead by MWS followed the Langmuir model with a maximum sorption capacity (qmax) of 31.85 mg/g and pseudo second‐order kinetics under a specified set of conditions. The changes in the values of free energy (ΔG°) and enthalpy (ΔH°) indicated the spontaneous, feasible and endothermic nature of sorption process. MWS has been found to be better biosorbent for lead ions than simple wheat straw and certain other biosorbents. WS and urea are easily available, cost effective, and the modification process is simple. So, MWS appears to be a cost effective material for Pb (II) sorption.
Oxidative Phenol Degradation Using Non‐Noble Metal Based Catalysts
Authors: Garg Anurag , Mishra Indra Mani , Chand Shri
Published: January 2010

Phenol laden waste streams are not considered suitable for conventional biological treatment if phenol is present in amounts higher than 70 mg/L. Catalytic wet air oxidation (CWAO) is one of the potential methods for treating waste streams containing such compounds. The present work investigated the degradation of synthetic wastewater contaminated with phenol (1 g/L) using a CWAO process in the presence of homogenous (CuSO4) and heterogeneous (LaCoO3, CuX and CuO‐ZnO/CeO2) catalysts. The reaction was conducted at low temperature (90°C) and atmospheric pressure, and at moderate operating conditions (T ⪈ 160°C and total pressure ⪇0.8 MPa). Among all the tested catalysts, CuSO4, LaCoO3 and CuX were used for WAO reactions performed at atmospheric pressure conditions, whereas the performance of CuO‐ZnO/CeO2 catalyst was tested in above atmospheric pressure studies. At atmospheric conditions, homogeneous CuSO4 was found to be the best showing ca. 90% phenol degradation and ca. 83% chemical oxygen demand (COD) reduction after a 24 h reaction period. The above atmospheric studies with catalyst showed ca. 82% phenol reduction and 54% COD removal within 3 h reaction time. The effect of pH, catalyst concentration, pressure and temperature are also reported. Finally, the major results are summarized and the recommendations for future work are given.
Sulfur Dioxide Removal by Using Leather Factory Wastewater
Authors: Ipek Ubeyde
Published: January 2010

This study shows the ability of wastewater from a liming and unhairing unit in a leather factory to remove sulfur dioxide (SO2). The pH of the wastewater reached neutral values during SO2 removal by wet scrubbing. Experiments were carried out at five inlet flue SO2 concentrations. These concentrations were 1000, 2000, 3000, 4000, and 5000 ppm. The results indicate that the inlet SO2 concentration influenced the removal efficiency and the maximum removal efficiencies varied from 96 to 99%. When the inlet SO2 concentration and the flow rate of the flue were kept around 1000 ppm and 44 L/s, respectively, the SO2 concentration in the outlet flue was determined to be less than 50 ppm after 80 s. Subsequently, the SO2 concentration ranged from 10–50 ppm after 13 minutes. At the end of the running period, the wastewater was also neutralized. When the inlet concentration was increased to around 2000 ppm, the concentrations of SO2 in the outlet flue ranged from 10–50 ppm after 7 minutes. SO2 removal decreased as the SO2 concentration in the inlet flue increased.
Membrane Filtration of Nickel(II) on Cellulose Acetate Filters for Its Preconcentration, Separation, and Flame Atomic Absorption Spectrometric Determination
Authors: Soylak Mustafa , Unsal Yunus Emre , Aydin Ayse , Kizil Nebiye
Published: January 2010

An enrichment method for trace amounts of Ni(II), as 8‐hydroxyquinoline chelates, has been established on a cellulose acetate membrane filter. Ni(II)‐8‐hydroxyquinoline chelates adsorbed on a membrane filter were eluted using 5 mL of 1 M HNO3. The eluent nickel concentration was determined by a flame atomic absorption spectrometer. The influence of some analytical parameters, including pH, amount of reagent, sample volume, etc., on recovery was investigated. The interference of co‐existent ions was studied. The nickel detection limit was 4.87 μg/L. The method was applied to real samples for the determination of nickel(II) ions.
Gas Permeable‐Membrane for Hydrogenotrophic Denitrification
Authors: Hasar Halil , Ipek Ubeyde
Published: January 2010

The membrane biofilm reactor (MBfR) involves a process in which the membrane provides effective H2 utilization as an electron donor. MBfRs overcome the problems caused from the particularly low solubility of the gas delivered into a liquid by means of a gas‐permeable membrane. The study demonstrates that the MBfR is successful in the effective removal of nitrate from drinking water or nitrified water, involving a hydraulic retention time of 25 min for a maximum nitrate removal of 98%. The H2 flux reaches a level of 1.24 g H2/m2 d when the denitrification rate achieves 3.5 g N/m2 d at 0.2 atm H2 pressure. The results indicate that the biofilm on outer walls of the gas permeable membrane utilizes all of the H2 gas effectively as an electron donor since the H2 is not detectable in the bulk liquid. In the future, the MBfR could be an attractive process for water and wastewater engineers due to its applicability for treatment of secondary effluent from industrial and municipal wastewater and drinking water.
Hg(II) Removal from Aqueous Solutions by Bacillus subtilis Biomass
Authors: Wang Xue Song , Li Fei Yan , He Wen , Miao Hua Hua
Published: January 2010

The biosorption of Hg(II) from aqueous solutions using Bacillus subtilis biomass was investigated in this study. The adsorbent was characterized by FTIR. Various factors including solution pH, initial concentration of Hg(II), contact time, reaction temperature and ionic strength were taken into account and promising results were obtained. An initial solution pH of 5.0 was most favorable for Hg(II) removal. The kinetic data was also analyzed using pseudo first order and pseudo second order equations. The results suggested that Hg(II) bioadsorption was best represented by the pseudo second order equation. Freundlich, Langmuir and Langmuir‐Freundlich isotherms for the present systems were analyzed. The most satisfactory interpretation for the equilibrium data at different temperatures was given by the Langmuir‐Freundlich isotherm. The effect of ionic strength on bioadsorption was significant. Bacillus subtilis biomass could serve as low cost adsorbent to remove Hg(II) from aqueous solutions, especially at lower concentrations of Hg(II) (<20 mg Hg/L).
Myosin diversity in the diatom Phaeodactylum tricornutum
Authors: Heintzelman Matthew B. , Enriquez Matthew E.
Published: January 2010

This report describes the domain architecture of ten myosins cloned from the pennate diatom Phaeodactylum tricornutum. Several of the P. tricornutum myosins show similarity to myosins from the centric diatom Thalassiosira pseudonana as well as to one myosin from the oomycete Phytophthora ramorum. The P. tricornutum myosins, ranging in size from 126 kDa to over 250 kDa, all possess the canonical head, neck and tail domains common to most myosins, though variations in each of these domains is evident. Among the features distinguishing several of the diatom myosin head domains are N‐terminal SH3‐like domains, variations in or near the P‐loop and Loop 1 regions close to the nucleotide binding pocket, and extended converter domains. Variations in the length of the neck domain or lever arm, defined by the light chain‐binding IQ motifs, are apparent with the different diatom myosins predicted to contain from one to nine IQ motifs. Protein domains found within the P. tricornutum myosin tails include regions of coiled‐coil structure, ankyrin repeats, CBS domain pairs, a PB1 domain, a kinase domain and a FYVE‐finger motif. As many of these features have never before been characterized in myosins of any type, it is likely that these new diatom myosins will expand the repertoire of known myosin behaviors. © 2010 Wiley‐Liss, Inc.
MAP65 in tubulin/colchicine paracrystals of Vigna sinensis root cells: Possible role in the assembly and stabilization of atypical tubulin polymers
Authors: Panteris Emmanuel , Komis George , Adamakis Ioannis‐Dimosthenis S. , Šamaj Jozef , Bosabalidis Artemios M.
Published: January 2010

Members of the MAP65 family, colocalizing with microtubule arrays, have been identified in Vigna sinensis root cells by Western blotting and immunofluorescence. MAP65 proteins were also found in tubulin/colchicine paracrystals, which were formed during colchicine treatment by both immunofluorescence and immunogold microscopy. During recovery from colchicine, MAP65 signal was depleted from disintegrating paracrystals appearing in the reinstating microtubule arrays. MAP65‐free perinuclear tubulin/colchicine aggregates were observed in plasmolyzed colchicine‐treated cells. Deplasmolysis of the above cells resulted in the formation of MAP65‐decorated paracrystals. As confirmed by appropriate biochemical assays with the Phos‐tag reagent, MAP65 proteins underwent phosphorylation during plasmolysis, which was reversible by deplasmolysis. According to the effect of the mitogen‐activated protein kinase (MAPK) inhibitor UO126, the phosphorylation status of MAP65, as well as its presence in tubulin/colchicine polymers is probably controlled by MAPK‐mediated phosphorylation. According to the above, it seems likely that apart from binding to microtubules, MAP65 proteins may act as “tubulin associated proteins” in a broader manner, promoting the polymerization and/or stabilization of atypical polymers such as tubulin/colchicine paracrystals. © 2010 Wiley‐Liss, Inc.
Implications of key trials in advanced nonsmall cell lung cancer
Authors: Bonomi Philip D.
Published: January 2010

Many different targeted therapies with varying mechanisms of action have been added to standard first‐line chemotherapy doublets in an effort to improve survival of patients with advanced nonsmall cell lung cancer (NSCLC). Only 2 targeted therapies—bevacizumab and cetuximab—have been associated with superior survival in phase 3 first‐line studies. For both agents, the decision to enter phase 3 was based on results from randomized phase 2 trials, unlike other targeted therapies where the decision was made using either phase 1 or single study arm phase 2 results. There is also mounting evidence that patient selection will play a key role in the successful development of any targeted agent. Bevacizumab is indicated for patients with nonsquamous NSCLC who do not have certain comorbidities. Use of cetuximab is not restricted by safety factors, but may be focused on patients whose tumors are epidermal growth factor receptor (EGFR)‐dependent; whether EGFR expression or absence of KRAS mutations are appropriate markers is still under study. By including randomized phase 2 trials in the development pathway, and by improving patient selection for individual agents (enriching trials with patients most likely to respond), it may be possible to enhance the success rate of future phase 3 clinical trials and, in turn, define future clinical practice with improved patient outcomes. Cancer 2010. © 2010 American Cancer Society.
Genetic alterations between primary head and neck squamous cell carcinoma and recurrence after radiotherapy
Authors: Deganello Alberto , Franchi Alessandro , Sardi Iacopo , Pignataro Lorenzo , Leemans C. René , Gallo Oreste
Published: January 2010

BACKGROUND:

In the attempt to characterize the genetic bases of recurrent head and neck squamous cell carcinoma (HNSCC) after radiotherapy (RT), the authors compared the molecular profiles of primary tumors and recurrences.

METHODS:

TP53 gene status and instability at 10 microsatellite markers were determined in pre‐RT lesions and corresponding local recurrences in a series of 16 HNSCCs.

RESULTS:

Eight (50%) HNSCCs showed both TP53 and microsatellite instability (MSI) status concordance in pre‐ and postirradiation biopsies; 3 (18.7%) showed discordance of both TP53 and MSI status; and finally 5 (31.2%) had discordance at only 1 genetic test. Accordingly, the authors interpreted as true recurrence the 8 concordant cases, and as true second primary malignancies the 3 discordant ones. In the remaining 5 cases with partial DNA correspondence, the exact nature of the new lesion only partially related to the original cancer is a matter of discussion. Patients showing the same mutations among pre‐ and post‐RT HNSCCs had a longer disease‐free interval (DFI) and better survival than those showing discordant genetic features (log‐rank test, P = .0045).

CONCLUSIONS:

Post‐RT recurrent HNSCCs are genetically heterogeneous. The genetic characterization of the recurrence, especially in those cases with a particularly short DFI showing partially discordant mutations, might have a useful clinical relevance in the restaging process. Cancer 2010. © 2010 American Cancer Society.
Elevated levels of the acute‐phase serum amyloid are associated with heightened lung cancer risk
Authors: Cremona Mattia , Calabrò Elisa , Randi Giorgia , De Bortoli Maida , Mondellini Piera , Verri Carla , Sozzi Gabriella , Pierotti Marco A. , La Vecchia Carlo , Pastorino Ugo , Bongarzone Italia
Published: January 2010

BACKGROUND:

The authors investigated whether early stage lung cancer could be identified by proteomic analyses of plasma.

METHODS:

For the first case‐control study, plasma samples from 52 patients with lung cancer and from a group of 51 controls were analyzed by surface‐enhanced laser desorption/ionization time‐of‐flight mass spectrometry. In a second case‐control study, a classifier of 4 markers (mass‐to‐charge ratio, 11,681, 6843, 5607, and 8762) also was tested for validation on plasma from 16 consecutive patients with screen‐detected cancer versus 406 healthy individuals. The most relevant marker was identified, and an enzyme‐linked immunosorbent assay‐based analysis revealed that signal intensity was correlated with concentration.

RESULTS:

The classifier had a sensitivity of 94.23% and a specificity of 76.47% in the first study but lost predictive value in the second study. Nevertheless, the 11,681 cluster, which was identified as serum amyloid protein A (SAA), resulted in a multiple logistic regression model that indicated a strong association with lung cancer. When both studies were considered as a together, the odds ratio (OR) for an SAA intensity ≥0.5 was 10.27 (95% confidence interval [CI], 4.64‐22.74), whereas an analysis restricted to stage I cancers (TNM classification) revealed an OR of 8.45 (95% CI, 2.76‐25.83) for T1 lung cancer and 21.22 (95% CI, 5.62‐80.14) for T2 lung cancer.

CONCLUSIONS:

SAA levels were predictive of an elevated risk of lung cancer, supporting the general view that inflammation is implicated in lung cancer development. Cancer 2010. © 2010 American Cancer Society.