Distribution by Scientific Domains
Distribution within Medical Sciences

Kinds of Vehicle

  • autonomous underwater vehicle
  • autonomous vehicle
  • delivery vehicle
  • different vehicle
  • drug delivery vehicle
  • effective vehicle
  • electric vehicle
  • gene delivery vehicle
  • ground vehicle
  • heavy-duty vehicle
  • hybrid electric vehicle
  • hybrid vehicle
  • important vehicle
  • main vehicle
  • marine vehicle
  • motor vehicle
  • moving vehicle
  • multiple vehicle
  • other vehicle
  • passenger vehicle
  • potential vehicle
  • saline vehicle
  • topical vehicle
  • transport vehicle
  • underwater vehicle
  • unmanned aerial vehicle
  • vs. vehicle

  • Terms modified by Vehicle

  • vehicle accident
  • vehicle alone
  • vehicle collision
  • vehicle control
  • vehicle count
  • vehicle crash
  • vehicle cream
  • vehicle gel
  • vehicle group
  • vehicle incident
  • vehicle injection
  • vehicle model
  • vehicle only
  • vehicle route
  • vehicle routing problem
  • vehicle safety
  • vehicle speed
  • vehicle system
  • vehicle treatment
  • vehicle tunnels
  • vehicle type

  • Selected Abstracts


    Jeng-Yu Wang
    ABSTRACT In this paper, we present various linear analyses of the linearized lateral dynamics of heavy-duty vehicles (HDVs) (tractor-semitrailer type), which include time domain, frequency domain and pole/zero analyses. These analyses are conducted to examine the vehicle response to the steering input subjected to variations of speed, road adhesion coefficient, cargo load in the trailer, and look-ahead distance for the lateral deviation sensor. These parameters (uncertainties) have significant influence on vehicle dynamics. It has been shown that redefining the look-ahead lateral error as the controlled output has a favorable impact on the lateral control problem. Based on these analyses, a robust steering controller using H, loop-shaping procedure is designed for a tractor semitrailer combination to follow the road center line on both curved and straight highway sections. The proposed controller ensures the robust performance under model uncertainties which include varying vehicle longitudinal speed, road adhesion coefficient, and cargo load in the trailer. The performance of the designed controller is evaluated by simulations and validated by experiments. [source]

    Road Infrastructure Data Acquisition Using a Vehicle-Based Mobile Mapping System

    Gi-Hong Kim
    The mobile mapping system that integrates the global positioning system (GPS), the inertial navigation system (INS), and digital cameras has been developed to collect data on position and attributes of road infrastructure. The vehicle-based mobile mapping system works by having the GPS and INS record the position and attitude data, and digital cameras take road images. The stereovision system can determine the position of objects that are visible on the image pair in the global coordinate system with GPS and INS data. As field data acquisition is a very expensive task, a mobile mapping system offers a greatly improved solution. In this study, we successfully created a road infrastructure map with mobile mapping technology and proposed automatic algorithms for detecting and identifying road signs from road images. The proposed detection algorithm includes line and color region extraction processes and uses the Hopfield neural networks. The identification algorithm uses seven invariant moments and parameters that present geometric characteristics. With this combined method, we could successfully detect and identify road signs. [source]

    Effects of cevoglitazar, a dual PPAR,/, agonist, on ectopic fat deposition in fatty Zucker rats

    D. Laurent
    Aim:, By acting as both insulin sensitizers and lipid-lowering agents, dual-acting peroxisome proliferator-activated receptors ,/, (PPAR,/,) agonists may be used to improve glucose tolerance in type 2 diabetic patients without inducing adiposity and body weight gain. Here, in an animal model of obesity and insulin resistance, the metabolic response to cevoglitazar, a dual PPAR,/,, was characterized using a combination of in vivo and ex vivo magnetic resonance methodologies and compared to treatment effects of fenofibrate, a PPAR, agonist, and pioglitazone, a PPAR, agonist. Methods:, Four groups of fatty Zucker rats: (i) Vehicle; (ii) fenofibrate 150 mg/kg; (iii) pioglitazone 30 mg/kg; and (iv) cevoglitazar 5 mg/kg were investigated before and after treatment. Animals were fed a fat-enriched (54% kcal fat) diet for 6 weeks, 2 weeks high of fat,exposure alone followed by a 4-week dosing period. Results and conclusions:, Cevoglitazar was as effective as pioglitazone at improving glucose tolerance. However, unlike pioglitazone, both fenofibrate and cevoglitazar reduced BW gain and adiposity, independent of food intake. All three treatment regimens normalized intramyocellular lipids. Metabolic profiling showed that in the muscle cevoglitazar improves the lipid profile via both PPAR,- and PPAR,-mediated mechanisms. Pioglitazone reduced hepatic lipid accumulation, while cevoglitazar and fenofibrate reduced hepatic lipid concentration below baseline levels (p < 0.05). Metabolic profiling showed that in the liver, cevoglitazar functions largely through PPAR, agonism resulting in increased ,-oxidation. Cevoglitazar only induced small changes to the lipid composition of visceral fat. In subcutaneous fat, however, cevoglitazar induced changes similar to those observed with fenofibrate suggesting export of fatty acids from this depot. [source]

    Cardioprotection of cariporide evaluated by plasma myoglobin and troponin I in myocardial infarction in pigs

    Robert Létienne
    Abstract The cardioprotective effects of cariporide were investigated against myoglobin and troponin I elevation in a model of myocardial infarction in pig, and the possible relationship between these markers and myocardial infarct size. The left circumflex coronary artery was ligated for 60-min and then reperfused for 48-h. Plasma levels of myoglobin and troponin I were quantified during reperfusion. Vehicle or cariporide (2.5 mg/kg) were administered i.v. before ischaemia and infused throughout ischaemia and for the beginning of reperfusion. In vehicle-treated pigs, the infarct size represented 26% ± 3% of the area at risk. Cariporide significantly decreased the infarct size by 66% ± 9%, and significantly reduced plasma levels of myoglobin and troponin I. A strongly correlated linear relationship between myocardial necrosis and plasma levels of myoglobin (R = 0.966, P < 0.0001) or troponin I (R = 0.855, P < 0.0001) was clearly identified. In conclusion, in our porcine model of myocardial infarction, even with small infarcts (in the presence of cariporide), plasma levels of myoglobin and troponin I are predictive of the presence of necrosis and its extent. [source]

    Energy Saving Speed and Charge/Discharge Control of a Railway Vehicle with On-board Energy Storage by Means of an Optimization Model

    Masafumi Miyatake Member
    Abstract The optimal operation of rail vehicle minimizing total energy consumption is discussed in this paper. In recent years, the energy storage devices have enough energy and power density to use in trains as on-board energy storage. The on-board storage can assist the acceleration/deceleration of the train and may decrease energy consumption. Many works on the application of the energy storage devices to trains were reported, however, they did not deal enough with the optimality of the control of the devices. The authors pointed out that the charging/discharging command and vehicle speed profile should be optimized together based on the optimality analysis. The authors have developed the mathematical model based on a general optimization technique, sequential quadratic programming. The proposed method can determine the optimal acceleration/deceleration and current commands at every sampling point under fixed conditions of transfer time and distance. Using the proposed method, simulations were implemented in some cases. The electric double layer capacitor (EDLC) is assumed as an energy storage device in our study, because of its high power density etc. The trend of optimal solutions such as values of control inputs and energy consumption is finally discussed. Copyright © 2009 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc. [source]

    Soft Decision with Soft Target for Car-like Mobile Vehicle in Dynamic Environment

    Yougen Chen Non-member
    Abstract Online flexible operation of a car-like mobile vehicle with non-holonomic constraints in dynamic environment is still a very challenging problem because the surrounding situations are not qualified in static, knowledge is only partial and the execution is often associated with uncertainty. The difficulty lies in the setting of appropriate moving sub-targets in real-time to obtain a collision-free and low-cost path. In this paper, we present a new approach for the autonomous motion control of mobile vehicle in a narrow area with static and dynamic obstacles. It is based on the selection of sub-target points of vehicle's movement called ,soft target' which is a target set defined as all possible and reachable via-points in a navigation space. The soft target is acquired by online learning based on the final target and environment information. Each element of it has its membership value in [0, 1] denoting its evaluation degree. With the acquired soft target, soft decision is made like human's decision process by predictive fuzzy control (PFC) to achieve final target safely and economically. The simulation results show the effectiveness and flexibility of the proposed vehicle motion control method. © 2009 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc. [source]

    Post-Traumatic Stress Disorder in Children and Adolescents With Motor Vehicle,Related Injuries

    Kathleen A. Zink MSN
    ISSUES AND PURPOSE Motor vehicle crashes account for the greatest number of childhood injuries, but there has been little study of the psychological responses. DESIGN AND METHODS This longitudinal, descriptive study included 143 children 7 to 15 years of age who experienced a motor vehicle,related injury. Parents/guardians completed the Child Behavior Checklist Behavioral Problem Scale. Each child and parent completed the post-traumatic stress disorder (PTSD) section of the Diagnostic Interview for Children and Adolescents at 2 and 6 months postinjury. RESULTS Twenty-two percent of the children met criteria for PTSD. There were no associations for presence or absence of PTSD with age, gender, race, injury, or cause of injury. PRACTICE IMPLICATIONS Children who are injured in motor vehicle crashes are at risk for PTSD. Anticipatory guidance about behavioral distress symptoms should be provided to parents of children who experience motor vehicle related injuries. [source]

    The On-Road Difficulties of Older Drivers and Their Relationship with Self-Reported Motor Vehicle Crashes

    Joanne M. Wood PhD
    OBJECTIVES: To quantify the driving difficulties of older adults using a detailed assessment of driving performance and to link this with self-reported retrospective and prospective crashes. DESIGN: Prospective cohort study. SETTING: On-road driving assessment. PARTICIPANTS: Two hundred sixty-seven community-living adults aged 70 to 88 randomly recruited through the electoral roll. MEASUREMENTS: Performance on a standardized measure of driving performance. RESULTS: Lane positioning, approach, and blind spot monitoring were the most common error types, and errors occurred most frequently in situations involving merging and maneuvering. Drivers reporting more retrospective or prospective crashes made significantly more driving errors. Driver instructor interventions during self-navigation (where the instructor had to brake or take control of the steering to avoid an accident) were significantly associated with higher retrospective and prospective crashes; every instructor intervention almost doubled prospective crash risk. CONCLUSION: These findings suggest that on-road driving assessment provides useful information on older driver difficulties, with the self-directed component providing the most valuable information. [source]

    A New Navigation Method for an Automatic Guided Vehicle

    Chen Wuwei
    This paper presents a new navigation method for an automatic guided vehicle (AGV). This method utilizes a new navigation and control scheme based on searching points on an arc. Safety measure indices are defined and are generated from the output of a fuzzy neural network which define the actions the AGV is to take when in the presence of obstacles. The proposed algorithm integrates several functions required for automatic guided vehicle navigation and tracking control and it exhibits satisfactory performance when maneuvering in complex environments. The automatic guided vehicle with this navigation control system not only can quickly process environmental information, but also can efficiently avoid dynamic or static obstacles, and reach targets safely and reliably. Extensive simulation and experimental results demonstrate the effectiveness and correct behavior of this scheme. © 2004 Wiley Periodicals, Inc. [source]

    Mechatronic Design and Locomotion of Amoebot,A Metamorphic Underwater Vehicle

    I-Ming Chen
    The Metamorphic Underwater Vehicle (MUV) is a vehicle that propels in the water by continuously changing the shape of its body similar to the motion of the microorganism amoebae. In this article, we describe the basic design of Amoebot, a plastic MUV that achieves shape-changing capability through the inflation and deflation of water-filled balloons. A sequence of inflation and deflation procedures can be taken to produce cyclic swimming shapes that propel the MUV. Swimming shapes similar to the microorganism amoebae have been successfully reproduced by present Amoebot. The mechanical system designed proves to be very reliable and flexible in producing desired body shapes. The physical shape of the Amoebot is analyzed numerically and its variation in time during the swim can be expressed explicitly. By formulating sets of idealized swimming rules based on the changing shape, simulations are carried out to predict the trajectory and study the pseudo dynamics of the swimming of Amoebot. Possible applications of this type of underwater vehicle are discussed. © 2003 Wiley Periodicals, Inc. [source]

    Michael Novak's Business as a Calling as a Vehicle for Addressing Ethical and Policy Concerns in a Business Law Course

    Tonia Hap Murphy

    In vivo anabolic effect of strontium on trabecular bone was associated with increased osteoblastogenesis of bone marrow stromal cells,

    Songlin Peng
    Abstract In vitro studies have demonstrated that strontium (Sr) could increase osteogenic differentiation of bone marrow stromal cells (BMSCs). We investigated the in vivo effect of Sr on BMSCs. Thirty-six female rats were randomly divided into the following groups: sham operated and treated with either vehicle (Sham,+,Veh) or Sr compound (Sham,+,Sr) and ovariectomized and treated with either vehicle (OVX,+,Veh) or Sr compound (OVX,+,Sr). Vehicle and Sr were orally administrated daily starting immediately after the surgery and continuing for 12 weeks. The anabolic effect of Sr on trabecular bone was determined at the structural and tissue level by microCT and histomorphometry, respectively. Colony formation assays demonstrated that BMSCs exhibited higher osteogenic colony but lower adipogenic colony in Sr-treated versus Veh-treated OVX rats. The mRNA level of osteogenic genes was higher, while the mRNA level of adipogenic genes was lower in BMSCs from Sr-treated versus Veh-treated Sham and OVX rats. The effect of Sr on rat BMSCs was reproducible in human BMSCs. Taken together, this study suggests that the anabolic effect of Sr on normal or osteoporotic bones is associated with increased osteoblastic differentiation of BMSCs. © 2010 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 28:1208,1214, 2010 [source]

    Age of Drinking Onset and Injuries, Motor Vehicle Crashes, and Physical Fights After Drinking and When Not Drinking

    ALCOHOLISM, Issue 5 2009
    Ralph W. Hingson
    Background:, Earlier age of drinking onset has been associated with greater odds of involvement in motor vehicle crashes, unintentional injuries, and physical fights after drinking. This study explores whether early drinkers take more risks even when sober by comparing potential associations between age of drinking onset and these outcomes after drinking relative to when respondents have not been drinking. Method:, From a national sample, 4,021 ever-drinkers ages 18 to 39 were asked age of drinking onset, not counting tastes or sips. They were also asked if they were ever in motor vehicle crashes, unintentionally injured, or in physical fights after drinking and when not drinking. GEE logistic regression models for repeated measures dichotomous outcomes compared whether odds ratios between age of onset and these adverse outcomes significantly differed when they occurred after drinking versus when not drinking, controlling for respondents' demographic characteristics, cigarette and marijuana use, family history of alcoholism, ever experiencing alcohol dependence, and frequency of binge drinking. Results:, Compared with persons who started drinking at age 21+, those who started at ages <14, 14 to 15, 16 to 17, and 18 to 20 had, after drinking, respectively greater odds: 6.3 (2.6, 15.3), 5.2 (2.2, 12.3), 3.3 (1.5, 7.3), and 2.2 (0.9, 5.1) of having been in a motor vehicle crash; 6.0 (3.4, 10.5), 4.9 (3.0, 8.6), 3.7 (2.4, 5.6), and 1.9 (1.2, 2.9) of ever being in a fight; and 4.6 (2.4, 8.7), 4.7 (2.6, 8.6), 3.2 (1.9, 5.6), and 2.3 (1.3, 4.0) of ever being accidentally injured. The odds of experiencing motor vehicle accidents or injuries when not drinking were not significantly elevated among early onset drinkers. The odds of earlier onset drinkers being in fights were also significantly greater when respondents had been drinking than not drinking. Conclusion:, Starting to drink at an earlier age is associated with greater odds of experiencing motor vehicle crash involvement, unintentional injuries, and physical fights when respondents were drinking, but less so when respondents had not been drinking. These findings reinforce the need for programs and policies to delay drinking onset. [source]

    Red Blood Cell Templated Polyelectrolyte Capsules: A Novel Vehicle for the Stable Encapsulation of DNA and Proteins

    Oliver Kreft
    Abstract Summary: A novel method for the encapsulation of biomacromolecules, such as nucleic acids and proteins, into polyelectrolyte microcapsules is described. Fluorescence-labelled double-stranded DNA and human serum albumin (HSA) are used as model substances for encapsulation in hollow microcapsules templated on human erythrocytes. The encapsulation procedure involves an intermediate drying step. The accumulation of DNA and HSA in the capsules is observed by confocal laser scanning microscopy, UV spectroscopy, and fluorimetry. The mechanism of encapsulation is discussed. Confocal fluorescence microscopy images of encapsulated TRITC-HSA (left) and dsDNA (right). Inserts demonstrate fluorescence profiles for both compounds. [source]

    Scientific exploration of near-Earth objects via the Orion Crew Exploration Vehicle

    Paul A. Abell
    The ideal mission profile would involve two or three astronauts on a 90 to 180 day flight, which would include a 7 to 14 day stay for proximity operations at the target NEO. This mission would be the first human expedition to an interplanetary body beyond the Earth-Moon system and would prove useful for testing technologies required for human missions to Mars and other solar system destinations. Piloted missions to NEOs using the CEV would undoubtedly provide a great deal of technical and engineering data on spacecraft operations for future human space exploration while conducting in-depth scientific investigations of these primitive objects. The main scientific advantage of sending piloted missions to NEOs would be the flexibility of the crew to perform tasks and to adapt to situations in real time. A crewed vehicle would be able to test several different sample collection techniques and target specific areas of interest via extra-vehicular activities (EVAs) more efficiently than robotic spacecraft. Such capabilities greatly enhance the scientific return from these missions to NEOs, destinations vital to understanding the evolution and thermal histories of primitive bodies during the formation of the early solar system. Data collected from these missions would help constrain the suite of materials possibly delivered to the early Earth, and would identify potential source regions from which NEOs originate. In addition, the resulting scientific investigations would refine designs for future extraterrestrial resource extraction and utilization, and assist in the development of hazard mitigation techniques for planetary defense. [source]

    Nonlinear FEM Simulation of Air Cushion Vehicle (ACV) Skirt Joint Under Tension Loading

    The mechanical properties of an air cushion vehicle (ACV) skirt cloth, which is a nonlinear rubber-coated fabric, are tested on a Series IX 4465 electron tension machine manufactured by Instron Company. Compared with the Mooney,Rivlin and Ogden form, the second-order Mooney,Rivlin form agrees with the model test result better. The ultimate bearing capacity of an ACV skirt joint structure is tested on a mechanical tension machine and the ultimate load is recorded manually. Then, considering the contact effect of each assembly and the large-displacement of skirt elements, a nonlinear finite element method (FEM)-based simulation process of an ACV skirt joint structure under tension loading is presented. The simulation process comprises three steps: assembly of parts, bolts' tightening, and tensioning the skirt cloth. Under these loadings, the stress distribution and deformation of the skirt cloth, and the cloth broken locations and directions are obtained. These results agree well with the test results. As for the ultimate bearing capacity of the skirt joint, the simulation result is slightly smaller than the test result. Thus, this FEM-based simulation method is proven to be reliable and relatively conservative. [source]

    Navy Omni-Directional Vehicle (ODV) Development: Where the Rubber Meets the Deck

    H. McGowen
    ABSTRACT The Office of Naval Research sponsored the omnidirectional vehicle (ODV) development program of the Coastal Systems Station (CSS). CSS has investigated the application of ODV technology to Navy shipboard materials and ordnance handling. Under the Navy program, ODV technology was developed and a series of vehicles were built and tested. ODT technology was demonstrated to be applicable to the shipboard environment and shown to be able to overcome conditions of confined spaces, reduced traction, ship motion, decks heeled at high angles, and on-deck obstacles. This paper focuses on the Navy's demonstration of the capability of the ODV to operate under demanding environmental conditions, ODV mechanical simplicity, and adaptability of the technology for a wide range of applications. Potential commercial applications were identified in manufacturing and warehousing, and remotely controlled or autonomous platforms employed in nuclear facilities, hazardous waste cleanup, and other operations that require the movement and precise positioning of large, heavy objects. The Navy has implemented two cooperative research and development agreements (CRADA) and others are pending for further development and transfer of ODV technology to the private sector. [source]

    The United Nations as a Vehicle for Dialogue

    PEACE & CHANGE, Issue 4 2003
    Courtney B. Smith
    The United Nations (UN) proclaimed 2001 as the Year of Dialogue among Civilizations in an effort to examine how confrontation and hostility in world politics could be replaced by discourse and understanding. However, in the midst of this process the world was witness to the tragic events of September 11, 2001. Since terrorism represents the antithesis to dialogue, the UN's discussion of these issues became more urgent and focused. Two major documents were produced, but they do not explore adequately the United Nations' potential role in regard to building dialogue. This article begins this undertaking by considering the UN as a forum for debate where different peoples of the world meet and as a catalyst for an ongoing process of interaction and change. In other words, serious thinking about the UN's role as a vehicle for dialogue requires appreciating both its passive and dynamic characteristics and functions. [source]

    Fatal Passenger Vehicle Crashes With At Least 1 Driver Younger Than 15 Years: A Fatality Analysis Reporting System Study

    Larry Frisch MD
    ABSTRACT:,Context: A small number of fatalities continue to occur due to motor vehicle crashes on highways in which at least 1 passenger vehicle (automobile, van, or small truck) is driven by a child younger than 15 years. Purpose: The purpose of this study was to extend previous work suggesting that such crashes occur frequently in the Southern states and have relatively high rates in rural areas in the South and Great Plains. Methods: This study utilizes data for the 5-year period 1999-2003 from the National Highway Transportation Safety Administration's online Fatality Analysis Reporting System. All cases were identified in which at least 1 conventional passenger vehicle in a fatal crash was being driven by a child younger than 15 years. Findings: During the 5-year period, 350 fatal crashes occurred with at least 1 driver younger than 15 years involved. Twenty-one of these drivers were licensed (11) or driving with a learner's permit (10). A total of 987 individuals in 419 vehicles were involved in these crashes, and 402 deaths resulted (1.16 deaths/crash). These crashes occurred primarily in Texas, Florida, Arkansas, and Arizona, but the highest rates per 100,000 children were found in North and South Dakota and predominantly in a band of Intermountain and Plains states. There was a strong correlation between crash rates and several measures of rurality. Conclusions: Crashes involving young, largely unlicensed, drivers account for about 70 deaths yearly. [source]

    In vivo real-time imaging of TGF-,-induced transcriptional activation of the RANK ligand gene promoter in intraosseous prostate cancer

    THE PROSTATE, Issue 4 2004
    Jian Zhang
    Abstract BACKGROUND Current animal models of prostate cancer (CaP) bone metastasis do not allow measurement of either tumor growth in bone over time or activation of gene promoters in intraosseous tumors. To develop these methods, we used bioluminescent imaging (BLI) to determine if expression of receptor activator of NF-,B ligand (RANKL), a pro-osteoclastogenic factor that promotes CaP bone metastases, is modulated by the bone matrix protein transforming growth factor-, (TGF-,) in vivo. METHODS C4-2B human CaP cells were treated with TGF-, in vitro and RANKL mRNA and protein production were measured by polymerase chain reaction (PCR) and ELISA, respectively. Then C4-2B cells stably transfected with the RANKL promoter driving luciferase (lux) were injected intra-tibially into severe combined immundeficient (SCID) mice. Tumors were subjected to BLI every 2 weeks for 6 weeks and serum prostate specific antigen (PSA) was measured using ELISA. Vehicle (V), 1,25 dihydroxyvitamin D (VitD), or TGF-, was administered to mice with established tumors and BLI to measure RANKL promoter activity was performed. Tumors were then subjected to immunohistochemistry for lux and assayed for RANKL mRNA levels. RESULTS TGF-, induced RANKL protein and mRNA expression and activated the RANKL promoter activity in a dose-dependent manner in vitro. BLI demonstrated an increase in intraosseous tumor size over time, which correlated with serum PSA levels. Administration of TGF-, and VitD to mice with established intraosseous tumors increased lux activity compared to V. Intratibial tumor RANKL mRNA expression paralleled the increased promoter activity. Immunohistochemistry confirmed the presence of lux in the intraosseous tumors. CONCLUSIONS These results demonstrate the ability to measure intraosseous tumor growth over time and gene promoter activation in an established intraosseous tumor in vivo and also demonstrate that TGF-, induces activates the RANKL promoter. These results provide a novel method to explore the biology of CaP bone metastases. © 2004 Wiley-Liss, Inc. [source]

    Barriers to Integration in the Mississippi Delta: Could Charter Schools Be the New Vehicle for Desegregation?

    Suzanne E. Eckes
    This study explored the barriers to educational integration in the rural Mississippi Delta region. In Delta County,1students have generally been divided between a black public school and an all white private academy. An earlier study (Eckes, 2005) revealed that white parents in Delta County chose not to send their students to the traditional public school because they perceived greater discipline problems, less challenging academics, and fewer extracurricular opportunities ("the barriers"). The black parents, however, were choosing not to send their children to the private academy because it did not, in fact, offer greater educational opportunity. Black parents contended that the three articulated barriers were actually euphemisms for racism. In this current case study, the researcher sought to learn whether a new high-performing charter school, where the three barriers were not present, would encourage racial integration in Delta County. Specifically, the new public charter school offered parents a third option in addition to the private academy and public school. Through interviews and observations, the current case study explored whether the barriers articulated by white parents in the earlier study were simply rhetoric. The current study found that white parents were still not choosing the charter school, even though no barriers were present. [source]

    A Tumor-Acidity-Activated Charge-Conversional Nanogel as an Intelligent Vehicle for Promoted Tumoral-Cell Uptake and Drug Delivery,

    ANGEWANDTE CHEMIE, Issue 21 2010
    Jin-Zhi Du
    Ein positives (oder negatives) Chamäleon: Ein bei physiologischen pH-Werten negativ und bei den pH-Werten im extrazellulären Bereich von Tumoren positiv geladenes Nanogel wurde durch die Tumorzellen in,vitro wie in,vivo effizient internalisiert (siehe Bild). Auch die Wirkstoff-Freisetzung in der Zelle war verstärkt, vielleicht als Folge einer geringeren Wechselwirkung zwischen dem Wirkstoff und dem protonierten Nanogel. [source]

    Potential of Fortified Fibrin/Hyaluronic Acid Composite Gel as a Cell Delivery Vehicle for Chondrocytes

    ARTIFICIAL ORGANS, Issue 6 2009
    Sang-Hyug Park
    Abstract Numerous treatment methods have been applied for use in cartilage repair, including abrasion, drilling, and microfracture. Although chondrocyte transplantation is the preferred treatment, it has some shortcomings, such as difficulty of application (large and posterior condylar regions), poor chondrocyte distribution, and potential cell leakage from the defect region. The cell delivery system of the tissue engineering technique can be used to overcome these shortcomings. We chose fibrin/hyaluronan (HA) composite gel as an effective cell delivery system to resolve these issues. Both components are derived from natural extracellular matrix. In the first trial, fortified fibrin/HA composite gels with rabbit chondrocytes were tested by implantation in nude mice. At 4 weeks, glycosaminoglycan contents in the fibrin/HA composite (0.186 ± 0.006 mg/mg) were significantly higher than those in the presence of fibrin alone (0.153 ± 0.017 mg/mg). As a next step, we applied the fibrin/HA composite gel to animal cartilage defects using full thickness cartilage defect rabbit models. The fibrin/HA composite gel with rabbit chondrocytes (allogenic) was implanted into the experimental group, and the control group was implanted with the fibrin/HA composite gel alone. Implanted chondrocytes with the fibrin/HA composite showed improved cartilage formation. In conclusion, the key to successful regeneration of cartilage is to provide the repair site with a sufficient supply of chondrogenic cells with a suitable delivery vehicle to ensure maximal differentiation and deposition of the proper extracellular matrix. This study suggests the feasibility of tissue-engineered cartilage formation using fibrin/HA composite gel. [source]

    Porous Inorganic Capsules in Action: Modelling Transmembrane Cation-Transport Parameter-Dependence Based on Water as Vehicle.

    CHEMINFORM, Issue 45 2005
    Erhard T. K. Haupt
    Abstract For Abstract see ChemInform Abstract in Full Text. [source]

    Transfer of hydrocarbons from natural seeps to the water column and atmosphere

    GEOFLUIDS (ELECTRONIC), Issue 2 2002
    I. R. MacDonald
    Abstract Results from surface geochemical prospecting, seismic exploration and satellite remote sensing have documented oil and gas seeps in marine basins around the world. Seeps are a dynamic component of the carbon cycle and can be important indicators for economically significant hydrocarbon deposits. The northern Gulf of Mexico contains hundreds of active seeps that can be studied experimentally with the use of submarines and Remotely Operated Vehicles (ROV). Hydrocarbon flux through surface sediments profoundly alters benthic ecology and seafloor geology at seeps. In water depths of 500,2000 m, rapid gas flux results in shallow, metastable deposits of gas hydrate, which reduce sediment porosity and affect seepage rates. This paper details the processes that occur during the final, brief transition , as oil and gas escape from the seafloor, rise through the water and dissolve, are consumed by microbial processes, or disperse into the atmosphere. The geology of the upper sediment column determines whether discharge is rapid and episodic, as occurs in mud volcanoes, or more gradual and steady, as occurs where the seep orifice is plugged with gas hydrate. In both cases, seep oil and gas appear to rise through the water in close proximity instead of separating. Chemical alteration of the oil is relatively minor during transit through the water column, but once at the sea surface its more volatile components rapidly evaporate. Gas bubbles rapidly dissolve as they rise, although observations suggest that oil coatings on the bubbles inhibit dissolution. At the sea surface, the floating oil forms slicks, detectable by remote sensing, whose origins are laterally within ,1000 m of the seafloor vent. This contradicts the much larger distance predicted if oil drops rise through a 500 m water column at an expected rate of ,0.01 m s,1 while subjected to lateral currents of ,0.2 m s,1 or greater. It indicates that oil rises with the gas bubbles at speeds of ,0.15 m s,1 all the way to the surface. [source]

    Energy Saving and Environmental Measures in Railway Technologies: Example with Hybrid Electric Railway Vehicles

    Masamichi Ogasa Member
    Abstract The electric railway system is the highest class of energy efficient transportation means. This is due to two important points: (i) low running resistance (including low energy losses) and (ii) energy regeneration in braking. Regenerative braking of railway electric vehicles is effective when the other powering ones, in other words electrical load, exist near the regenerating train on the same electrified line. So, early in the morning and at midnight, or in the low-density district lines, regeneration cancellation phenomenon often occurs and the regenerative brake force cannot be operated in accordance with the recommended value. Newly appeared high-performance energy storage devices press the issues of energy storage and reuse technologies on ground and on vehicles. Hybrid energy source is one effective solution. In this paper, as an example, we show our trolley and on-board battery hybrid controlled tramcar, developed to reduce regeneration cancellation. With the trolley line collective power as well as charge and discharge power of the on-board lithium ion rechargeable battery, the hybrid energy providing and regenerating technology is achieved. The running test results show a maximum regenerative ratio of 44%, which is top class value in an electric railway system. Copyright © 2007 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc. [source]

    Antimicrobial Nanotubes Consisting of Ag-Embedded Peptidic Lipid-Bilayer Membranes as Delivery Vehicles

    ADVANCED MATERIALS, Issue 17 2009
    Yong Zhou
    Functional drug-delivery vehicles consisting of Ag-embedded bilayer membranes of a peptidic lipid nanotube (LNT) are synthesized. The Ag,LNTs possess antimicrobial ability against E coli, contributing to the release of Ag+ into the aqueous culture. The Ag,LNTs may be applicable to the delivery of DNA or biotechnological drugs that are usually sensitive to changes in their surroundings. [source]

    Cooperative control of multiple vehicles with limited sensing

    Jian Chen
    Abstract A navigation function based cooperative control is developed in this paper for the navigation of multiple Unmanned Aerial Vehicles (UAVs) in the presence of known stationary obstacles and unknown enemy assets (EAs). Specifically, the motion of UAVs are planned in a centralized fashion. The standard navigation function approach is extended to a multiple navigation strategy with an analytical switch among different cases due to the limited sensing zone of the UAVs. A differentiable controller is proposed based on this navigation function that yields asymptotic convergence. A discussion for avoiding moving EAs is presented. Simulation results are provided to illustrate the performance of the proposed control strategy. Copyright © 2006 John Wiley & Sons, Ltd. [source]

    Solution of the Dial-a-Ride Problem with multi-dimensional capacity constraints

    K. I. Wong
    Abstract The Dial-a-Ride Problem (DARP) consists of planning routes and schedules for picking up and delivering users within user-specified time windows. Vehicles of a given fleet with limited capacity depart from and end at a common depot. The travel time of passengers cannot exceed a given multiple of the minimum ride time. Other constraints include vehicle capacity and vehicle route duration. In practice, scheduling is made more complicated by special user requirements and an inhomogeneous vehicle fleet. The transportation of elderly and handicapped people is an important example, as space for wheelchairs is limited and a lift is required. In this study, we present a modified insertion heuristic to solve the DARP with multi-dimensional capacity constraints, and the performance of the proposed algorithm is tested in simulation. We show that the proposed methodology is effective when compared with the classic algorithms. [source]

    Remote Weaponry: The Ethical Implications

    abstract The nature of warfare is changing. Increasingly, developments in military technology are removing soldiers from the battlefield, enabling war to be waged from afar. Bombs can be dropped from unmanned drones flying above the range of retaliation. Missiles can be launched, at minimal cost, from ships 200 miles to sea. Micro Air Vehicles, or ,WASPS', will soon be able to lethally attack enemy soldiers. Though still in the developmental stage, progress is rapidly being made towards autonomous weaponry capable of selecting, pursuing, and destroying targets without the necessity for human instruction. These developments have a profound , and as yet under-analysed , impact on just war theory. I argue that a state under attack from remote weaponry is unable to respond in the traditional, just war sanctioned, method of targeting combatants on the battlefield. This restriction of options potentially creates a situation whereby a state is either coerced into surrender, or it must transgress civilian immunity. Just war theory in conditions of remote warfare therefore either serves the interests of the technologically advanced by demanding the surrender of targeted states, or else it becomes redundant. [source]