WorldWideScience

Sample records for open graded aggregates

  1. Performance evaluation of open-graded epoxy asphalt concrete with two nominal maximum aggregate sizes

    Institute of Scientific and Technical Information of China (English)

    罗桑; 钱振东; 薛永超

    2015-01-01

    Open-graded friction course (OGFC) is applied to pavement surfaces to increase driving safety under wet conditions, and recently, to reduce tire/pavement noise. The durability of OGFC, however, has been a concern since conventional OGFC mixes last typically less than ten years before major maintenance or rehabilitation is needed. This work investigates a new open-graded asphalt mixture that uses epoxy asphalt as binder to improve mix durability. One type of epoxy asphalt that has been successfully applied to dense-graded asphalt concrete for bridge deck paving was selected. A procedure of compacting the mix into slab specimens was developed and a series of laboratory tests were conducted to evaluate the performance of the new mix, including Cantabro loss, permeability, friction, shear strength, and wheel rutting tests. Results show superior overall performance of the open-graded epoxy asphalt mix compared to conventional open-graded asphalt mix. There are also preliminary indications that the OGFC mix with 4.75-mm NMAS gradation can improve the resistance performance to raveling, while the OGFC mix with 9.5-mm NMAS gradation can improve the performance of surface friction at a high slip speed.

  2. Performance evaluation of open-graded epoxy asphalt concrete with two nominal maximum aggregate sizes

    Institute of Scientific and Technical Information of China (English)

    罗桑; 钱振东; 薛永超

    2015-01-01

    Open-graded friction course(OGFC) is applied to pavement surfaces to increase driving safety under wet conditions, and recently, to reduce tire/pavement noise. The durability of OGFC, however, has been a concern since conventional OGFC mixes last typically less than ten years before major maintenance or rehabilitation is needed. This work investigates a new open-graded asphalt mixture that uses epoxy asphalt as binder to improve mix durability. One type of epoxy asphalt that has been successfully applied to dense-graded asphalt concrete for bridge deck paving was selected. A procedure of compacting the mix into slab specimens was developed and a series of laboratory tests were conducted to evaluate the performance of the new mix, including Cantabro loss, permeability, friction, shear strength, and wheel rutting tests. Results show superior overall performance of the open-graded epoxy asphalt mix compared to conventional open-graded asphalt mix. There are also preliminary indications that the OGFC mix with 4.75-mm NMAS gradation can improve the resistance performance to raveling, while the OGFC mix with 9.5-mm NMAS gradation can improve the performance of surface friction at a high slip speed.

  3. Open Graded Asphalt Mixture Design for Environmentally Friendly Road

    Science.gov (United States)

    Setyawan, A.; Suryoto; Sumarsono, A.; Widyastuti, S.

    2017-02-01

    The road is an important infrastructure to support various economic development. By increasing the population, the constructions of road infrastructure are obviously required and cover more land use area, consequently narrowed the areas for water absorption into the land. Therefore, it is necessary to improve more environmentally friendly of road constructions, in this case is by using open graded asphalt. Open graded asphalt is the mixture of asphalt with low fine aggregate content to produce a high percentage of air voids, which expected to be able to absorb water into the land underneath. This observation uses laboratory experiment method. Materials that are used are natural gravel and the volcanic gravel, 60/70 asphalt penetration and stone dust filler. The tests performed for the samples are Marshall test, falling head water permeability, indirect tensile strength and unconfined compressive strength. The optimum bitumen content for each type of aggregate have been found to be 2.95% for natural gravel and 4.65% for volcanic gravel. Open graded asphalt porosity is 26.52% for natural gravel, whereas the volcanic gravel is 22.31%. The vertical and horizontal permeability for natural gravel are 1.25 cm/second and 0.92 cm/second, respectively. Whereas, for the volcanic gravel is 1.43 cm/second and 1.10 cm/second, respectively. Indirect tensile strength (ITS) value for natural gravel is 59.49 KPa whereas the volcanic gravel is 74.84 KPa. The unconfined compressive strength (UCS) value for natural gravel is 1070.63 KPa, whereas the volcanic gravel is 1120.69 KPa. It is concluded that the open graded porous asphalt is only compatible for low volume traffic road and need improvement to be able to be used as standard road.

  4. Effect of the aggregate grading on the concrete air permeability

    Directory of Open Access Journals (Sweden)

    Argiz, C.

    2014-09-01

    Full Text Available Great durability problems are being found in concrete structures related to the penetrability of aggressive agents through the concrete (ie. chloride penetration, sulphate attack, carbonation, freezing and thawing, and so on. Air permeability coefficient is used as an effective tool to estimate the potential durability of concrete structures due to its direct relation with the microstructure and the moisture content. This paper discusses the effect of the aggregate grading and water/cement ratio on the air permeability coefficient. An aggregate grading with more sand than coarse aggregates has resulted more beneficial from the point of view of concrete air permeability. This fact can be attributed to a denser skeleton formed by the finer aggregates. With fine aggregates, the higher water/cement ratio, the lower air permeability. However, the contrary was found with coarse aggregates. Overall, a temperature increase from 20 °C to 60 °C during preconditioning led to a Dair increase of 40–80%.Se han encontrado una gran cantidad de problemas de durabilidad de estructuras de hormigón relacionados con la penetración de agentes agresivos externos (es decir, penetración de cloruros, ataque por sulfatos, carbonatación, hielo-deshielo, etc.. El coeficiente de permeabilidad al aire se utiliza como una herramienta eficaz para estimar la durabilidad potencial de las estructuras de hormigón debido a su relación directa con su microestructura y contenido de humedad. Se discute el efecto de la gradación de los áridos y relación agua/cemento en el coeficiente de permeabilidad al aire. Con áridos más finos que gruesos, el resultado es más beneficioso, lo que se atribuye a que la arena forma un esqueleto más denso. Con áridos más finos, al aumentar la relación agua/cemento, disminuye la permeabilidad al aire; pero con áridos más gruesos se ha observado lo contrario. Cuando se pre-acondiciona de 20 °C a 60 °C, se produce un aumento del Dair

  5. Effect of polymer aggregation on the open circuit voltage in organic photovoltaic cells: aggregation-induced conjugated polymer gel and its application for preventing open circuit voltage drop.

    Science.gov (United States)

    Kim, Bong-Gi; Jeong, Eun Jeong; Park, Hui Joon; Bilby, David; Guo, L Jay; Kim, Jinsang

    2011-03-01

    To investigate the structure-dependent aggregation behavior of conjugated polymers and the effect of aggregation on the device performance of conjugated polymer photovoltaic cells, new conjugated polymers (PVTT and CN-PVTT) having the same regioregularity but different intermolecular packing were prepared and characterized by means of UV-vis spectroscopy and atomic force microscopy (AFM). Photovoltaic devices were prepared with these polymers under different polymer-aggregate conditions. Polymer aggregation induced by thermal annealing increases the short circuit current but provides no advantage in the overall power conversion efficiency because of a decrease in the open circuit voltage. The device fabricated from a pre-aggregated polymer suspension, acquired from ultrasonic agitation of a conjugated polymer gel, showed enhanced performance because of better phase separation and reduced recombination between polymer/PCBM.

  6. Behavior of Low Grade Steel Fiber Reinforced Concrete Made with Fresh and Recycled Brick Aggregates

    Directory of Open Access Journals (Sweden)

    Md. Shariful Islam

    2017-01-01

    Full Text Available In recent years, recycled aggregates from construction and demolition waste (CDW have been widely accepted in construction sectors as the replacement of coarse aggregate in order to minimize the excessive use of natural resources. In this paper, an experimental investigation is carried out to observe the influence of low grade steel fiber reinforcements on the stress-strain behavior of concrete made with recycled and fresh brick aggregates. In addition, compressive strength by destructive and nondestructive tests, splitting tensile strength, and Young’s modulus are determined. Hooked end steel wires with 50 mm of length and an aspect ratio of 55.6 are used as fiber reinforcements in a volume fraction of 0% (control case, 0.50%, and 1.00% in concrete mixes. The same gradation of aggregates and water-cement ratio (w/c=0.44 were used to assess the effect of steel fiber in all these concrete mixes. All tests were conducted at 7, 14, and 28 days to perceive the effect of age on different mechanical properties. The experimental results show that around 10%~15% and 40%~60% increase in 28 days compressive strength and tensile strength of steel fiber reinforced concrete, respectively, compared to those of the control case. It is observed that the effect of addition of 1% fiber on the concrete compressive strength is little compared to that of 0.5% steel fiber addition. On the other hand, strain of concrete at failure of steel fiber reinforced concrete has increased almost twice compared to the control case. A simple analytical model is also proposed to generate the ascending portions of the stress-strain curve of concrete. There exists a good correlation between the experimental results and the analytical model. A relatively ductile failure is observed for the concrete made with low grade steel fibers.

  7. Automation of Capacity Bidding with an Aggregator Using Open Automated Demand Response

    Energy Technology Data Exchange (ETDEWEB)

    Kiliccote, Sila; Piette, Mary Ann

    2008-10-01

    This report summarizes San Diego Gas& Electric Company?s collaboration with the Demand Response Research Center to develop and test automation capability for the Capacity Bidding Program in 2007. The report describes the Open Automated Demand Response architecture, summarizes the history of technology development and pilot studies. It also outlines the Capacity Bidding Program and technology being used by an aggregator that participated in this demand response program. Due to delays, the program was not fully operational for summer 2007. However, a test event on October 3, 2007, showed that the project successfully achieved the objective to develop and demonstrate how an open, Web?based interoperable automated notification system for capacity bidding can be used by aggregators for demand response. The system was effective in initiating a fully automated demand response shed at the aggregated sites. This project also demonstrated how aggregators can integrate their demand response automation systems with San Diego Gas& Electric Company?s Demand Response Automation Server and capacity bidding program.

  8. Peer Grading in Astronomy Massive Open Online Course

    Science.gov (United States)

    Formanek, Martin; Wenger, Matthew; Impey, Christopher; Buxner, Sanlyn

    In this work we thoroughly investigate the peer grading process as it happened in the University of Arizona session based MOOC ``Astronomy: Exploring Time and Space'' offered during Spring 2015 through Coursera. Overall, 25400 learners from over 100 countries registered for this course. Of those, 14900 accessed at least one part of the course and 1332 users engaged in the peer grading. First of all we provide description of the peer graded assignments and we identify trends in behavior of people who participated in these exercises. E.g. time they spent on grading, number of assignments graded and patterns arising from comparing all three assignments. Furthermore, for the second assignment, we graded random sample of 300 essays by a group of trained undergraduate students and a group consisting of one of the course instructors together with graduate TAs and we compared results with grades from the peer grading. Specifically we look on Intraclass Correlation Coefficients for all three groups of graders to determine reliability of each group and correlations between final grades. Finally we assess factors influencing reliability of the peer graders participating in the MOOC based on the difference from our grades. This research was supported by Howard Hughes Medical Institute Grant No. 415580.

  9. Load-carrying capacity of lightly reinforced, prefabricated walls of lightweight aggregate concrete with open structure

    DEFF Research Database (Denmark)

    Goltermann, Per

    2009-01-01

    The paper presents and evaluates the results of a coordinated testing of prefabricated, lightly reinforced walls of lightweight aggregate concrete with open structure. The coordinated testing covers all wall productions in Denmark and will therefore provide a representative assessment of the qual...... of the quality actually produced. Existing and new formulas for the capacity are evaluated by comparison to the test results and a new model with a good correlation with the test results is presented....

  10. Obturating teeth with wide open apices using mineral trioxide aggregate: a case report.

    Science.gov (United States)

    Levenstein, H

    2002-07-01

    The conventional approach in handling a tooth with a wide open apex requiring endodontic treatment is by means of a procedure called apexification. The objective of treatment is to introduce calcium hydroxide mixed with sterile water or local anaesthetic into the root canal to create a hard-tissue-like formation or an apical plug to prevent extrusion of filling materials during obturation of teeth with wide open apices. This procedure may take anything from 6 months to 2 years. In 1999 a new material called mineral trioxide aggregate (MTA) was introduced to the dental profession for clinical use which has the ability to create an apical plug within a few weeks.

  11. Long-term aggregation of larval fish siblings during dispersal along an open coast.

    Science.gov (United States)

    Ottmann, Daniel; Grorud-Colvert, Kirsten; Sard, Nicholas M; Huntington, Brittany E; Banks, Michael A; Sponaugle, Su

    2016-12-06

    Pelagic dispersal of most benthic marine organisms is a fundamental driver of population distribution and persistence and is thought to lead to highly mixed populations. However, the mechanisms driving dispersal pathways of larvae along open coastlines are largely unknown. To examine the degree to which early stages can remain spatially coherent during dispersal, we measured genetic relatedness within a large pulse of newly recruited splitnose rockfish (Sebastes diploproa), a live-bearing fish whose offspring settle along the US Pacific Northwest coast after spending up to a year in the pelagic environment. A total of 11.6% of the recruits in a single recruitment pulse were siblings, providing the first evidence for persistent aggregation throughout a long dispersal period. Such protracted aggregation has profound implications for our understanding of larval dispersal, population connectivity, and gene flow within demersal marine populations.

  12. Laboratory evaluation of durability of open-graded friction course Mixtures

    Directory of Open Access Journals (Sweden)

    N. A. Qureshi

    2015-06-01

    Full Text Available Open-graded friction courses (OGFC are special purpose thin surface mixtures of hot mix asphalt (HMA pavement that is increasingly being used around the world. Owing to its safety aspects, OGFC is being regularly used as final riding surface on interstate and high speed expressways by different highway agencies in United States, including Alabama Department of Transportation. OGFC pavements in Alabama are facing premature failure due to different reasons. Loss of durability and functionality causes failure of OGFC pavements. Thus, research is needed to improve the durability of OGFC and enhance its beneficial properties. This research proposes methods to improve the durability of OGFC mixtures through laboratory performance testing. Aggregate gradation and layer thickness significantly affected the durability of the OGFC surfaces in general, especially the layer thickness. The Hamburg test indicated a 50-60% higher resistance to moisture damage of OGFC pavement with increase in thickness from 19 mm to 38 mm. The Cantabro stone loss of OGFC pavements is reduced 10- 50% with increase in thickness from 19 mm to 38 mm. The permeability tests results indicated 12-100% increase in permeability with increase in thickness of OGFC pavement from 19 mm to 38 mm. Indirect tensile strength tests indicated 50-300% increase in strength with increase in thickness of OGFC pavement from 19 mm to 38 mm.

  13. Research on Peer Grading in an Astronomy Massive Open Online Course

    Science.gov (United States)

    Formanek, Martin; Impey, Chris David; Wenger, Matthew; Sonam, Tenzin; Buxner, Sanlyn

    2017-01-01

    Massive Open Online Courses (MOOCs) are opportunities for thousands of students to take university level courses at little to no cost. The aim of this talk is to present and analyze an often used assessment tool in MOOCs - peer grading. We collected a wealth of data on peer grading process during our session based MOOC “Astronomy: Exploring Time and Space” offered through Coursera in Spring 2015. We found that peer-grading participants are different from the general course population. Additionally, we found that peer grading participation is the single best predictor for course completion. We compared three different essay-based peer graded assignments throughout the course according to the lengths of submitted essays, time spent grading, number of essays graded by individual users, and a percentage of relevant videos watched. In all of these criteria participation in the first assignment turned out to be statistically significantly different from the other two. Finally we investigated validity and reliability of peer graders by comparing their grades with trained undergraduate graders and instructors on a subsample of 300 essays. Although we found out that validity and reliability of peer grading is limited, we were still able to show that results of peer grading strongly correlate with the final grades from the course and also invested effort in general. Therefore despite its shortcomings, peer grading still manages to identify good students and is very viable tool useful for MOOC-scale formative assessment.

  14. Supporting Mediated Peer-Evaluation to Grade Answers to Open-Ended Questions

    Science.gov (United States)

    De Marsico, Maria; Sciarrone, Filippo; Sterbini, Andrea; Temperini, Marco

    2017-01-01

    We show an approach to semi-automatic grading of answers given by students to open ended questions (open answers). We use both peer-evaluation and teacher evaluation. A learner is modeled by her Knowledge and her assessments quality (Judgment). The data generated by the peer- and teacher-evaluations, and by the learner models is represented by a…

  15. OpenAQ: A Platform to Aggregate and Freely Share Global Air Quality Data

    Science.gov (United States)

    Hasenkopf, C. A.; Flasher, J. C.; Veerman, O.; DeWitt, H. L.

    2015-12-01

    Thousands of ground-based air quality monitors around the world publicly publish real-time air quality data; however, researchers and the public do not have access to this information in the ways most useful to them. Often, air quality data are posted on obscure websites showing only current values, are programmatically inaccessible, and/or are in inconsistent data formats across sites. Yet, historical and programmatic access to such a global dataset would be transformative to several scientific fields, from epidemiology to low-cost sensor technologies to estimates of ground-level aerosol by satellite retrievals. To increase accessibility and standardize this disparate dataset, we have built OpenAQ, an innovative, open platform created by a group of scientists and open data programmers. The source code for the platform is viewable at github.com/openaq. Currently, we are aggregating, storing, and making publicly available real-time air quality data (PM2.5, PM10, SO2, NO2, and O3) via an Application Program Interface (API). We will present the OpenAQ platform, which currently has the following specific capabilities: A continuous ingest mechanism for some of the most polluted cities, generalizable to more sources An API providing data-querying, including ability to filter by location, measurement type and value and date, as well as custom sort options A generalized, chart-based visualization tool to explore data accessible via the API At this stage, we are seeking wider participation and input from multiple research communities in expanding our data retrieval sites, standardizing our protocols, receiving feedback on quality issues, and creating tools that can be built on top of this open platform.

  16. Sorption Kinetics on Open Carbon Nanohorn Aggregates: The Effect of Molecular Diameter

    Directory of Open Access Journals (Sweden)

    Brice A. Russell

    2016-04-01

    Full Text Available We present the results of a study of the kinetics of adsorption on aggregates of open carbon nanohorns using argon and CF4 sorbates. We measured the equilibration times for each value of the sorbent loading along eight adsorption isotherms (four isotherms for each sorbate species. We found that: the equilibration times decrease as the sorbent loading (and the equilibrium pressure of the coexisting gas increases, for a given temperature; and, that, for a given value of the sorbent loading, the equilibration times decrease with increasing temperature. When considering the effect of scaling of the temperatures by the respective critical temperatures we found that, at the same scaled temperature and at comparable loadings, the equilibration times for CF4 were longer than those for argon. We discuss a possible explanation for this result.

  17. Sorption Kinetics on Open Carbon Nanohorn Aggregates: The Effect of Molecular Diameter.

    Science.gov (United States)

    Russell, Brice A; Khanal, Pravin; Calbi, Maria M; Yudasaka, Masako; Iijima, Sumio; Migone, Aldo D

    2016-04-21

    We present the results of a study of the kinetics of adsorption on aggregates of open carbon nanohorns using argon and CF₄ sorbates. We measured the equilibration times for each value of the sorbent loading along eight adsorption isotherms (four isotherms for each sorbate species). We found that: the equilibration times decrease as the sorbent loading (and the equilibrium pressure of the coexisting gas) increases, for a given temperature; and, that, for a given value of the sorbent loading, the equilibration times decrease with increasing temperature. When considering the effect of scaling of the temperatures by the respective critical temperatures we found that, at the same scaled temperature and at comparable loadings, the equilibration times for CF₄ were longer than those for argon. We discuss a possible explanation for this result.

  18. 应用excel自动计算沥青混合料矿料级配%Application of Excel to Automatically Calculate Mineral Aggregate Grading of Asphalt Mixture

    Institute of Scientific and Technical Information of China (English)

    陈瑶; 谢春来

    2012-01-01

    The formula to automatically calculate mineral through the application of functions of excels so as to perform rapidly. aggregate grading of asphalt mixture is established mineral aggregate grading design of asphalt mixture%应用excel功能,建立自动计算沥青混合料矿料级配公式,快速进行沥青混合料矿料级配设计。

  19. Grade 3C open femur fractures with vascular repair in adults.

    Science.gov (United States)

    Balci, Halil I; Saglam, Yavuz; Tunali, Onur; Akgul, Turgut; Aksoy, Murat; Dikici, Fatih

    2015-06-01

    Grade 3C open femur fractures are challenging injuries with higher rates of complications. This is a retrospective review of grade 3C open femur fractures with vascular repair between 2002 and 2012. Outcomes included initial MESS score, additional injuries, duration of operation, complications, secondary operations or amputations, and social life implications. Thirty-one of 39 total patients were selected for revascularization and fracture fixation based on soft tissue injury and MESS score. The intra-operative approach included temporary arterial shunt replacement, orthopedic fixation, arterial reconstruction venous and/or nerve repair and routine fasciotomies. An external fixation and reverse saphenous vein graft was used in a majority of the patients (respectively; 93.5%, 90.3%). The mean follow up was 5.4 years (range 2.2-10). The decision to amputate versus salvage should be left up to patients and their care teams after discussing options and future possibilities rather than using a scoring system.

  20. Performance Test for Open Grade Bitumen and Cement Mixture OGBC-20

    Science.gov (United States)

    Li, Y. Y.; Wu, Z. L.; Li, C. M.; Gan, X. Z.; Xiong, X. J.

    For effective prevention of urban road intersection special sections for nit diseases and improving the pavement durability, an open grade bitumen and cement (OGBC-20) mixture is proposed. In organic hydraulic cement mixture design, mix proportion designs of cement mortar and matrix open-graded bitumen were done. The matrix mixture gradation was adjusted .It has greater void of air volume than that of ATPB-25. A variety of tests in laboratory for OGBC-20 were performed. The experimental results show that: The void of air volume of adjusted gradation matrix asphalt mixture is up to 23%. and binder drainage loss is ≤ 0.3%. Cement mortar filling is fuller and better water stability and low temperature crack resistance compared to ordinary bitumen mixture. It has the absolute advantage on high temperature stability and shows the superiority of the new pavement materials.

  1. [Meaning of living with external fixation for grade III open fracture of lower limbs: patient view].

    Science.gov (United States)

    Lopez, Catia Cristina Gomes; Gamba, Mônica Antar; Matheus, Maria Clara Cassuli

    2013-06-01

    The present study is aimed to understand the meaning of living with an external fixation device for grade III open fractures of the lower limbs from the perspective of the patient. The data were collected with six young adults who were undergoing outpatient orthopedic treatment in a public hospital in the city of São Paulo, through semi-structured interviews with open questions, between June and August 2010. Seeking to understand the meaning of this experience, we have maintained a phenomenological attitude during the analysis, which made it possible to reveal the phenomenon "try to live in spite of feeling trapped in a cage." Patients said that their personal desire and support from others helped them reorganize their lives, despite the several challenges they had to overcome to adapt to the fastener attached to their body and the fear of the future and doubts about the success of treatment.

  2. The Hygroscopic Opening of Sesame Fruits Is Induced by a Functionally Graded Pericarp Architecture

    Science.gov (United States)

    Shtein, Ilana; Elbaum, Rivka; Bar-On, Benny

    2016-01-01

    To enhance the distribution of their seeds, plants often utilize hygroscopic deformations that actuate dispersal mechanisms. Such movements are based on desiccation-induced shrinkage of tissues in predefined directions. The basic hygroscopic deformations are typically actuated by a bi-layer configuration, in which shrinking of an active tissue layer is resisted by a stiff layer, generating a set of basic movements including bending, coiling, and twisting. In this study, we investigate a new type of functionally graded hygroscopic movement in the fruit (capsule) of sesame (Sesamum indicum L.). Microscopic observations of the capsules showed that the inner stiff endocarp layer is built of a bilayer of transverse (i.e., circumferential) and longitudinal fiber cells with the layers positioned in a semi-circle, one inside the other. The outer mesocarp layer is made of soft parenchyma cells. The thickness of the fibrous layers and of the mesocarp exhibits a graded architecture, with gradual changes in their thickness around the capsule circumference. The cellulose microfibrils in the fiber cell walls are lying parallel to the cell long axis, rendering them stiff. The outer mesocarp layer contracted by 300% as it dried. Removal of this outer layer inhibited the opening movement, indicating that it is the active tissue. A biomechanical hygro-elastic model based on the relative thicknesses of the layers successfully simulated the opening curvature. Our findings suggest that the sesame capsules possess a functionally graded architecture, which promotes a non-uniform double-curvature hygroscopic bending movement. In contrast to other hygroscopic organs described in the literature, the sesame capsule actuating and resisting tissues are not uniform throughout the device, but changing gradually. This newly described mechanism can be exploited in bio-inspired designs of novel actuating platforms. PMID:27777579

  3. Research on Grading and Performance of Microbond Grading Gravel Mineral Aggregate in Vibration Method%振动法微粘结级配碎石矿料级配与性能研究

    Institute of Scientific and Technical Information of China (English)

    董树国

    2015-01-01

    On the basis of analyzing composition of skeleton of grading gravel coarse aggregate, this paper carries out indoor test by means of vibration compaction meter to research the rule of influences of fine aggregate on bearing characteristics of grading gravel and to optimize composition of the resulting mineral aggregate grading of dense skeleton type grading gravel. In addition, the paper adopts vibration molding method to conduct comparative test of the performance of microbond grading gravel of different structure types. The test results show that the interior structure types of microbond grading gravel exhibit important influences on its performance, and in comparison with suspension dense structure, the compressive strength and compressive elastic modulus of microbond grading gravel in skeleton dense structure are more superior, but the bending/stretching resistance is not as good.%在分析级配碎石粗集料骨架组成的基础上,采用振动压实仪进行室内CBR试验,以研究细集料含量对级配碎石承载特性的影响规律,并优化得出骨架密实型级配碎石的矿料级配组成. 另外,采用振动成型方式对不同结构类型微粘结级配碎石性能进行对比试验. 试验结果表明:微粘结级配碎石的内部结构类型对其性能有重要影响,与悬浮密实结构相比,骨架密实结构微粘结级配碎石的抗压强度与抗压回弹模量更优,而抗弯拉性能略差.

  4. One-stage emergency treatment of open grade IIIB tibial shaft fractures with bone loss.

    Science.gov (United States)

    Tropet, Y; Garbuio, P; Obert, L; Jeunet, L; Elias, B

    2001-02-01

    The purpose of this study was to report the authors' experience with emergency reconstruction of severe tibial shaft fractures. Five male patients were admitted to the emergency room with a grade IIIB open tibial shaft fracture with bone loss (average age, 33 years; age range, 18-65 years). Injuries were the result of motorcycle accidents (N = 2), pedestrian accidents (N = 1), gunshot wound (N = 1), and paragliding fall (N = 1). Primary emergent one-stage management for all patients consisted of administration of antibiotics, debridement, stabilization by locked intramedullary nailing, bone grafting from the iliac crest, and coverage using free muscle flaps (four latissimus dorsi and one gracilis). The average follow-up was 21 months (range, 8 months-3.5 years). Partial weight bearing with no immobilization was started at 3 months, and full weight bearing began 5 months after trauma. No angular complications and no nonunions were observed. There was one case of superficial infection without osteitis. All fractures healed within 6 months in 4 patients and within 10 months in 1 patient. At the last follow-up examination, ankle and knee motion was normal and no pain was noted, except for 1 patient who had associated lesions (ankle motion reduced by 50%). Aggressive emergency management of severe open tibial fractures provides good results. It improves end results markedly, not only by reducing tissue loss from infection, but also reducing healing and rehabilitation times.

  5. Uncertainty of soil erosion modelling using open source high resolution and aggregated DEMs

    Directory of Open Access Journals (Sweden)

    Arun Mondal

    2017-05-01

    Full Text Available Digital Elevation Model (DEM is one of the important parameters for soil erosion assessment. Notable uncertainties are observed in this study while using three high resolution open source DEMs. The Revised Universal Soil Loss Equation (RUSLE model has been applied to analysis the assessment of soil erosion uncertainty using open source DEMs (SRTM, ASTER and CARTOSAT and their increasing grid space (pixel size from the actual. The study area is a part of the Narmada river basin in Madhya Pradesh state, which is located in the central part of India and the area covered 20,558 km2. The actual resolution of DEMs is 30 m and their increasing grid spaces are taken as 90, 150, 210, 270 and 330 m for this study. Vertical accuracy of DEMs has been assessed using actual heights of the sample points that have been taken considering planimetric survey based map (toposheet. Elevations of DEMs are converted to the same vertical datum from WGS 84 to MSL (Mean Sea Level, before the accuracy assessment and modelling. Results indicate that the accuracy of the SRTM DEM with the RMSE of 13.31, 14.51, and 18.19 m in 30, 150 and 330 m resolution respectively, is better than the ASTER and the CARTOSAT DEMs. When the grid space of the DEMs increases, the accuracy of the elevation and calculated soil erosion decreases. This study presents a potential uncertainty introduced by open source high resolution DEMs in the accuracy of the soil erosion assessment models. The research provides an analysis of errors in selecting DEMs using the original and increased grid space for soil erosion modelling.

  6. ROMI 3.1 Least-cost lumber grade mix solver using open source statistical software

    Science.gov (United States)

    Rebecca A. Buck; Urs Buehlmann; R. Edward. Thomas

    2010-01-01

    The least-cost lumber grade mix solution has been a topic of interest to both industry and academia for many years due to its potential to help wood processing operations reduce costs. A least-cost lumber grade mix solver is a rough mill decision support system that describes the lumber grade or grade mix needed to minimize raw material or total production cost (raw...

  7. Effects of rejuvenator seal and fog seal on performance of open-graded friction course pavement

    Directory of Open Access Journals (Sweden)

    Nadeem A. Qureshi

    2013-05-01

    Full Text Available An open-graded friction course (OGFC is a special-purpose surface layer of hot-mix asphalt (HMA pavement that is increasingly being used around the world. Owing to its numerous benefits, OGFC is being regularly used as a final riding surface on interstate and high-traffic expressways by different highway agencies in the United States. However, some OGFC sections have experienced premature failure due to ravelling only after 6-8 years of service life. To maintain an effective, longer service life and enhanced performance of OGFC, preventive maintenance has been considered essential. There are several approaches to maintaining OGFC, one of which is the application of a fog seal and rejuvenator seal. A fog seal can reduce ravelling and extend the service life of OGFC while a rejuvenator seal can revitalise the existing aged asphalt binder in the top OGFC layer. This research focuses on optimising the fog and rejuvenator seal application rates by evaluating their effectiveness in terms of surface friction and durability. Three types of seal material were evaluated: Pavegaard (PG and Pavepreserve (PP asphalt rejuvenators and a cationic slow-setting asphalt emulsion (CSS-1H as a fog seal. Improvement in abrasion resistance of OGFC pavement was observed on application of fog and rejuvenator seals but surface friction was reduced to some extent. Hamburg test clearly shows a trend that the medium application rate of 0.10 gallon/square yard is better in enhancing resistance to rutting/moisture susceptibility of OGFC.

  8. Laser-based approach for determining flakiness index of aggregates used in pavements

    CSIR Research Space (South Africa)

    Anochie-Boateng, Joseph

    2011-07-01

    Full Text Available laboratory 3.2 Aggregates samples Rock aggregates used in five asphalt mixes of South Africa road pavements were selected for this study. The mixes include the types used for asphalt surfacing and base courses of original, modified and bitumen rubber... continuously graded mix with SBS modified binder Mix 3 = Medium continuously graded mix with SBS modified binder Mix 4 = Medium continuously graded mix with 60/70 penetration grade binder Mix 5 = Semi-open graded mix with bitumen rubber binder 3...

  9. Use of Ilizarov Fixator for Grade III B Open Olecranon Fracture: a Case Report and Surgical Technique

    Science.gov (United States)

    Sharad Nemade, Pradip; Dash, Kumar Kaushik; Patwardhan, Tanvi Yeshwant; Londhe, Pravin Vasant

    2015-01-01

    Introduction: External fixator application can be difficult for olecranon fractures in presence of large degloving injuries. We describe use of simple Ilizarov ring fixator construct for grade IIIB open olecranon fracture management. Case Report: A 45-year-old female with Grade III B open comminuted olecranon fracture (30*15cm degloving area) and ulnar nerve palsy was treated with a novel ring fixator construct. Two cut-end olive wires were passed from the proximal olecranon across the fracture site in intramedullary fashion exiting dorsally at mid-ulnar level through healthy skin and were attached to an Ilizarov half ring secured by perpendicular wires. The olive wires were tensioned, achieving compression and stability. Range of motion (ROM) exercises could be started quickly as the elbow was not spanned. Wound healed after skin grafting and at one-year follow-up the patient has good functional results (PRE 7, DASH 9.48), elbow ROM 10°-130°, 75° pronation and 85° supination. The patient returned to pre-injury occupational activities and had no pain. At three-year follow-up, the x-ray and CT showed union of olecranon fragment with well-maintained congruency. Conclusion: Internal fixation in most cases may be precluded by the soft tissue trauma and risk of infection. In addition, the small proximal fragment precludes a stable external fixation. In this technique, the hardware is kept away from the open wound allowing better wound inspection and care. The intramedullary olive wires provide compression and stability, and thus allow early ROM. Ilizarov half-ring and olive wire fixation can be an useful option for management of high grade open olecranon fractures because of its advantages, viz. stable fixation, minimal internal hardware, optimal wound care, immediate initiation of range of motion, and good outcome. PMID:27299012

  10. Cone Beam Computed Tomography Evaluation of the Periapical Status of Nonvital Tooth with Open Apex Obturated with Mineral Trioxide Aggregate: A Case Report

    Directory of Open Access Journals (Sweden)

    Vijay Shekhar

    2013-01-01

    Full Text Available Management of a tooth with open apex is a challenge to the dental practitioners. Evaluation of the periapical healing is required in such cases by radiographic techniques. The objective of this paper was to assess the healing of a periapical lesion in a non-vital tooth with open apex treated with mineral trioxide aggregate (MTA obturation using cone beam computed tomography (CBCT. The endodontic treatment of a fractured non-vital discolored maxillary left lateral incisor with an open apex was done with MTA obturation. The clinical and radiographic followup done regularly showed that the tooth was clinically asymptomatic and that the size of the periapical lesion observed by intraoral periapical (IOPA radiographs and CBCT was decreased remarkably after two years. CBCT and IOPA radiographs were found to be useful radiographic tools to assess the healing of a large periapical lesion in a non-vital tooth with open apex managed by MTA obturation.

  11. 贝雷法在级配碎石基层级配检验中的应用%Application of Bailey Method in Aggregate Grading Test of Graded Crushed Stone

    Institute of Scientific and Technical Information of China (English)

    徐云晴; 孟芹; 李贵乾; 吴楚钢

    2013-01-01

    Selecting within the scope of graded crushed stone specification, 12 typical aggregate gradations are examined by Bailey method combined with their mechanical index of CBR. The results show that the correlation coefficient of CA and CBR is 0.6901, the correlation coefficient of K-value and CBR is 0.8178, and FAc and FAf have no significant effect on CBR. Therefore, it is possible to evaluate the graded performance with CBR, CA and K- value. The CA value in 0.58 around the mixture has higher strength, and it is suggested that the K-value of CA is between 92.99~104.58.%引进贝雷法矿料级配检验手段,结合碎石力学指标CBR,对级配碎石规范范围内选取的12个典型的级配进行检验,分析了CA比、FAc比、FAf比和K值对CBR的影响.试验结果表明:CA和CBR的相关系数为0.6901,K值和CBR的相关系数为0.8178,FAc比和FAf比对CBR的影响不明显.因此,用CBR、CA比和K值这三项指标评价级配碎石性能是可行的.CA在0.58左右的级配碎石混合料有较高的强度,并建议其K值在92.99~104.58之间.

  12. The effect of crumb rubber particle size to the optimum binder content for open graded friction course.

    Science.gov (United States)

    Ibrahim, Mohd Rasdan; Katman, Herda Yati; Karim, Mohamed Rehan; Koting, Suhana; Mashaan, Nuha S

    2014-01-01

    The main objective of this paper is to investigate the relations of rubber size, rubber content, and binder content in determination of optimum binder content for open graded friction course (OGFC). Mix gradation type B as specified in Specification for Porous Asphalt produced by the Road Engineering Association of Malaysia (REAM) was used in this study. Marshall specimens were prepared with four different sizes of rubber, namely, 20 mesh size [0.841 mm], 40 mesh [0.42 mm], 80 mesh [0.177 mm], and 100 mesh [0.149 mm] with different concentrations of rubberised bitumen (4%, 8%, and 12%) and different percentages of binder content (4%-7%). The appropriate optimum binder content is then selected according to the results of the air voids, binder draindown, and abrasion loss test. Test results found that crumb rubber particle size can affect the optimum binder content for OGFC.

  13. The Role of Input and Interaction in English Reading of Grade One EFL Learners in an Open College

    Institute of Scientific and Technical Information of China (English)

    华一君

    2016-01-01

    This paper analyzes the role of reading textbook (input) as well as interaction between grade one students and teachers in Guangwai's Open College, aiming to seek for a tentative teaching method to improve reading comprehension of grade one EFL learners in the college. First, the features of input and interaction in the specific context were explored under the light of literature. Second, an experiment was carried on by comparing the comprehension results of three different groups of students under various conditions—a)simplified condition(SC), with modified lexical items and sentence structure; b)negotiated condition(NC), with no linguistic simplification but opportunity for students to interact with their teacher on the meaning of unfamiliar words and syntactic difficulties; c)unmodified condition (UC), with neither simplified input nor opportunity to negotiate with their teacher. The experiment reveals that some reading materials in the textbook is not suitable for"self-taught" students' automatic development of language knowledge and, interactional negotiation is a more efficient method than input simplification of original input.

  14. The effects of blogs versus dialogue journals on open-response writing scores and attitudes of grade eight science students

    Science.gov (United States)

    Erickson, Diane K.

    Today's students have grown up surrounded by technology. They use cell phones, word processors, and the Internet with ease, talking with peers in their community and around the world through e-mails, chatrooms, instant messaging, online discussions, and weblogs ("blogs"). In the midst of this technological explosion, adolescents face a growing need for strong literacy skills in all subject areas for achievement in school and on mandated state and national high stakes tests. The purpose of this study was to examine the use of blogs as a tool for improving open-response writing in the secondary science classroom in comparison to the use of handwritten dialogue journals. The study used a mixed-method approach, gathering both quantitative and qualitative data from 94 students in four eighth-grade science classes. Two classes participated in online class blogs where they posted ideas about science and responded to the ideas of other classmates. Two classes participated in handwritten dialogue journals, writing ideas about science and exchanging journals to respond to the ideas of classmates. The study explored these research questions: Does the use of blogs, as compared to the use of handwritten dialogue journals, improve the open-response writing scores of eighth grade science students? How do students describe their experience using blogs to study science as compared to students using handwritten dialogue journals? and How do motivation, self-efficacy, and community manifest themselves in students who use blogs as compared to students who use handwritten dialogue journals? The quantitative aspect of the study used data from pre- and post-tests and from a Likert-scale post-survey. The pre- and post-writing on open-response science questions were scored using the Massachusetts Comprehensive Assessment System (MCAS) open-response scoring rubric. The study found no statistically significant difference in the writing scores between the blog group and the dialogue journal

  15. Zeer open asfaltbeton ZOAB en de verkeersveiligheid.

    NARCIS (Netherlands)

    Schreuder, D.A.

    1992-01-01

    Open graded asphalt road surfaces make a great contribution to road safety by: a) improving the skidding resistance; b) reducing splash and spray; and c) ensuring and maintaining a high, diffuse light reflection, particularly in wet conditions. A tough, hard and light coloured aggregate is required

  16. The Effect of Crumb Rubber Particle Size to the Optimum Binder Content for Open Graded Friction Course

    Directory of Open Access Journals (Sweden)

    Mohd Rasdan Ibrahim

    2014-01-01

    Full Text Available The main objective of this paper is to investigate the relations of rubber size, rubber content, and binder content in determination of optimum binder content for open graded friction course (OGFC. Mix gradation type B as specified in Specification for Porous Asphalt produced by the Road Engineering Association of Malaysia (REAM was used in this study. Marshall specimens were prepared with four different sizes of rubber, namely, 20 mesh size [0.841 mm], 40 mesh [0.42 mm], 80 mesh [0.177 mm], and 100 mesh [0.149 mm] with different concentrations of rubberised bitumen (4%, 8%, and 12% and different percentages of binder content (4%–7%. The appropriate optimum binder content is then selected according to the results of the air voids, binder draindown, and abrasion loss test. Test results found that crumb rubber particle size can affect the optimum binder content for OGFC.

  17. Geostatistical modeling of facies, bitumen grade and particle size distribution for the Joslyn oil sand open pit mine project

    Energy Technology Data Exchange (ETDEWEB)

    Babak, Olena; Insalaco, Enzo; Mittler, Andreas [Total EandP Canada Ltd. (Canada)

    2011-07-01

    The Joslyn North Mine Project is currently in the pre-development stage; the aim of this study is to use different available data to draw a geological model of facies, bitumen grade, full particle size distribution (PSD) and ore/waste discrimination. The study was conducted with the database of around 800 wells, stochastic, indicator and Gaussian simulations were performed along with a sensitivity study. Results demonstrated the importance of some parameters for evaluating grade cases including variogram uncertainty, sampling limitations and errors in geostatistical workflow. In addition, modeling the full PSD dataset was shown to be useful. This study demonstrated how to use available database through an overall workflow to develop case scenarios for bitumen in place in ore and characterize the ore material.

  18. 3D for the people: multi-camera motion capture in the field with consumer-grade cameras and open source software

    Directory of Open Access Journals (Sweden)

    Brandon E. Jackson

    2016-09-01

    Full Text Available Ecological, behavioral and biomechanical studies often need to quantify animal movement and behavior in three dimensions. In laboratory studies, a common tool to accomplish these measurements is the use of multiple, calibrated high-speed cameras. Until very recently, the complexity, weight and cost of such cameras have made their deployment in field situations risky; furthermore, such cameras are not affordable to many researchers. Here, we show how inexpensive, consumer-grade cameras can adequately accomplish these measurements both within the laboratory and in the field. Combined with our methods and open source software, the availability of inexpensive, portable and rugged cameras will open up new areas of biological study by providing precise 3D tracking and quantification of animal and human movement to researchers in a wide variety of field and laboratory contexts.

  19. 3D for the people: multi-camera motion capture in the field with consumer-grade cameras and open source software.

    Science.gov (United States)

    Jackson, Brandon E; Evangelista, Dennis J; Ray, Dylan D; Hedrick, Tyson L

    2016-09-15

    Ecological, behavioral and biomechanical studies often need to quantify animal movement and behavior in three dimensions. In laboratory studies, a common tool to accomplish these measurements is the use of multiple, calibrated high-speed cameras. Until very recently, the complexity, weight and cost of such cameras have made their deployment in field situations risky; furthermore, such cameras are not affordable to many researchers. Here, we show how inexpensive, consumer-grade cameras can adequately accomplish these measurements both within the laboratory and in the field. Combined with our methods and open source software, the availability of inexpensive, portable and rugged cameras will open up new areas of biological study by providing precise 3D tracking and quantification of animal and human movement to researchers in a wide variety of field and laboratory contexts.

  20. Management of pulpal floor perforation and grade II Furcation involvement using mineral trioxide aggregate and platelet rich fibrin: A clinical report

    Directory of Open Access Journals (Sweden)

    Rhythm Bains

    2012-01-01

    Full Text Available To report the management of an iatrogenic perforation of pulpal floor in the furcation of mandibular first molar, using Mineral Trioxide Aggregate (MTA and platelet rich fibrin (PRF. Unpredictable endodontic root/pulp chamber floor perforations resulting in unacceptable high rate of clinical failure has now been a lesser threat with the advent of new technologies and biocompatible materials that utilize the applications of basic research along with tissue engineering concept in clinical practice. Present case report illustrates the use of MTA and platelet rich fibrin (PRF for the repair of the perforation defect and regeneration of the lost periodontium in furcation area. Although, histologic events and reaction of MTA with PRF is not studied so far, however, the autologous and biocompatible nature of the components used for present treatment modalities seems to be beneficial for the long term clinical results obtained in our case.

  1. Effectiveness of instruction in rubric use in improving fourth-grade students' science open-response outcomes

    Science.gov (United States)

    Bohlin, Sandra L.

    This study focused on the role of rubric instruction in assisting students to answer open-response science questions. The purpose sought to determine if rubric instruction could help students recognize levels of performance, thereby improving their open-response outcomes. Performance tasks and open-response questions regarding real-world problems are necessary to assess the skills of application of knowledge. Rubrics are appropriate for scoring open-response questions because they can assess how students solve problems, the accuracy of solutions, and also provide feedback to students about characteristics of different qualities of work. Rubrics have been used in studies involving assessment, but the effects of rubric use on student learning has not been directly investigated. The theoretical foundations and research related to the use of rubrics suggest that rubrics assist in helping students to recognize more or less adequate responses and thus provide a self-adjustment strategy to improve students' own performance. Previous research has shown that students are able to follow a model to learn strategies for performance, that cognitive strategies can be taught, and that self-regulation enhances academic learning. The effectiveness of six weeks of rubric instruction with practice and feedback was compared to practice only with no feedback, and with no treatment. Chi2 tests were used to compare high, medium, and low score categories from students' pre- and posttests. The first research question inquired as to the effects of rubric instruction on students' ability to identify various levels of response from science open-response answers. Students who received rubric instruction were more able to identify rubric levels on the posttest without the presence of the rubric because they were familiar with it from treatment while the other two groups were not. They did not improve their ability from pre- to posttest, however. The practice group's ability to identify response

  2. INFLUENCE OF GRADED AEROBIC EXERCISE ON QUALITY OF LIFE IN POST SURGICAL MITRAL VALVE DISEASE INDIVIDUAL A PROSPECTIVE RANDOMIZED OPEN LABEL STUDY

    Directory of Open Access Journals (Sweden)

    Shanthi C

    2016-10-01

    Full Text Available Background: Post surgical mitral valve disease individual focus their cardiac rehabilitation training on two major goal that is to improve cardiac output response exercises and place an important role in determining exercise tolerance and to improve quality of life. Cardiac rehabilitation programs involve prescribed exercise and education however various other method are being used to improve quality of life. But our study to find out the effectiveness of graded aerobic exercise protocol on ejection fraction and quality of life in post surgical mitral valve disease individuals. Methods: The study design was open label studies total of 100 post surgical mitral valve disease individuals patients from the age group of 20-60 years were recruited from SVIMS hospital. They were randomly divided into two groups. Group I underwent a twelve week structured graded individually tailored exercises. The group II received only none graded (not individualized exercise training. The ejection fraction and quality of life was measured before and after 12 weeks of exercise training for two groups. Results: Repeated measures ANOVA was used to compare mean values of continuous variables between baseline and at the time of discharge and three months after surgery for each parameter. Comparison of means between groups was done by the unpaired student t test. Mean age of the subjects was 40.18±10.29. There was a significant increase in the ejection fraction in the group I(61.34±2.49 to 64.4±3.31 compared to with the group II (61.06±2.51. to 61.62 ±2.37. QOL had improved in group I than group II at p<0.05. Conclusion: A 12 week structured graded aerobic exercise training significantly improved ejection fraction and quality of life in post surgical mitral valve disease individuals.

  3. Demography and movement patterns of leopard sharks (Triakis semifasciata) aggregating near the head of a submarine canyon along the open coast of southern California, USA

    Science.gov (United States)

    Nosal, D.C.; Cartamil, D.C.; Long, J.W.; Luhrmann, M.; Wegner, N.C.; Graham, J.B.

    2013-01-01

    The demography, spatial distribution, and movement patterns of leopard sharks (Triakis semifasciata) aggregating near the head of a submarine canyon in La Jolla, California, USA, were investigated to resolve the causal explanations for this and similar shark aggregations. All sharks sampled from the aggregation site (n=140) were sexually mature and 97.1 % were female. Aerial photographs taken during tethered balloon surveys revealed high densities of milling sharks of up to 5470 sharks ha-1. Eight sharks were each tagged with a continuous acoustic transmitter and manually tracked without interruption for up to 48 h. Sharks exhibited strong site-fidelity and were generally confined to a divergence (shadow) zone of low wave energy, which results from wave refraction over the steep bathymetric contours of the submarine canyon. Within this divergence zone, the movements of sharks were strongly localized over the seismically active Rose Canyon Fault. Tracked sharks spent most of their time in shallow water (≤2 m for 71.0 % and ≤10 m for 95.9 % of time), with some dispersing to deeper (max: 53.9 m) and cooler (min: 12.7 °C) water after sunset, subsequently returning by sunrise. These findings suggest multiple functions of this aggregation and that the mechanism controlling its formation, maintenance, and dissolution is complex and rooted in the sharks' variable response to numerous confounding environmental factors.

  4. Research on Autonomic Aggregation of Open Learning Resources%开放学习资源自主聚合研究

    Institute of Scientific and Technical Information of China (English)

    赵蔚; 张赛男; 孙彪; 李士平

    2015-01-01

    随着数字化学习资源大量涌现,基于资源的学习越来越受到人们的普遍关注。面对海量的资源,如何有效地聚合自己需要的知识资源,寻找知识资源的出处,获取知识间的关联,构建个人知识网络,满足学习者学习需求,已成为目前国内外学者的研究热点。该文通过对国内外资源聚合现状分析,梳理存在的不足,提出以“学习即知识的连结”为理念,关注学习者个体行为、学习者主动参与,以及学习者共同参与在资源聚合中的重要作用,将研究的重点从资源聚合的技术手段转为资源聚合的方式,将聚合的主体由“系统”转变为“学习者”,依靠“人”本身强大的语义理解与处理能力,聚合开放学习资源,实现了物化资源、人际资源、生成性资源的自主聚合,完成社会化资源网络的构建,并对研究成果进行了功能实现。%With the large numbers of digital learning resources, people pay more and more attention to learning resources based on web. People face with massive resources, how to effectively aggregate knowledge resources they need, to ifnd the source of the knowledge resources, to get the relationship of Knowledge, to build personal knowledge network have become a research focus. Based on the situation analysis of resources aggregation and the concept of study is knowledge connecting , this paper proposes to concern about the important role of the behavior of the individual learner, learner’s active participation, and learners’ participation in resource aggregation, to transfer the focus of research from the technology to the way and the aggregating body from system to learner.Systern rely on personal semantic understanding and processing capabilities, achieve the autonomic aggregation of physical resources, human resources and generative resources, and complete the construction of the social network of resources and the

  5. Dispersion and functionalization of nanoparticles synthesized by gas aggregation source: Opening new routes towards the fabrication of nanoparticles for bio-medicine

    Science.gov (United States)

    Oprea, B.; Martínez, L.; Román, E.; Vanea, E.; Simon, S.; Huttel, Y.

    2015-01-01

    The need to find new nanoparticles for biomedical applications is pushing the limits of the fabrication methods. New techniques with versatilities beyond the extended chemical routes can provide new insight in the field. In particular gas aggregation sources offer the possibility to fabricate nanoparticles with controlled size, composition and structure out of thermodynamics. In this context, the milestone is the optimization of the dispersion and functionalization processes of nanoparticles once fabricated by these routes as they are generated in the gas phase and deposited on substrates in vacuum or ultra-high vacuum conditions. In the present work we propose a fabrication route in ultra-high vacuum that is compatible with the subsequent dispersion and functionalization of nanoparticles in aqueous media and, that is more remarkable, in one single step. In particular, we will present the fabrication of nanoparticles with a sputter gas aggregation source, using a Fe50B50 target, and their further dispersion and functionalization with polyethileneglycol (PEG). A characterization of these nanoparticles is carried out before and after PEG functionalization. During functionalization, significant boron dissolution occurs, which facilitates nanoparticle dispersion in the aqueous solution. The use of different complementary techniques allows us to prove the PEG attachment onto the surface of the nanoparticles creating a shell to make them biocompatible. The result is the formation of nanoparticles with a structure mainly composed by a metallic Fe core and an iron oxide shell, surrounded by a second PEG shell dispersed in aqueous solution. Relaxivitiy measurements of these PEG functionalized nanoparticles assessed their effectiveness as contrast agents for Magnetic Resonance Imaging (MRI) analysis. Therefore, this new fabrication route is a reliable alternative for the synthesis of nanoparticles for biomedicine. PMID:26640032

  6. Temozolomide chemotherapy versus radiotherapy in high-risk low-grade glioma (EORTC 22033-26033) : a randomised, open-label, phase 3 intergroup study

    NARCIS (Netherlands)

    Baumert, Brigitta G; Hegi, Monika E; van den Bent, Martin J; von Deimling, Andreas; Gorlia, Thierry; Hoang-Xuan, Khê; Brandes, Alba A; Kantor, Guy; Taphoorn, Martin J B; Hassel, Mohamed Ben; Hartmann, Christian; Ryan, Gail; Capper, David; Kros, Johan M; Kurscheid, Sebastian; Wick, Wolfgang; Enting, Roelien; Reni, Michele; Thiessen, Brian; Dhermain, Frederic; Bromberg, Jacoline E; Feuvret, Loic; Reijneveld, Jaap C; Chinot, Olivier; Gijtenbeek, Johanna M M; Rossiter, John P; Dif, Nicolas; Balana, Carmen; Bravo-Marques, Jose; Clement, Paul M; Marosi, Christine; Tzuk-Shina, Tzahala; Nordal, Robert A; Rees, Jeremy; Lacombe, Denis; Mason, Warren P; Stupp, Roger

    2016-01-01

    BACKGROUND: Outcome of low-grade glioma (WHO grade II) is highly variable, reflecting molecular heterogeneity of the disease. We compared two different, single-modality treatment strategies of standard radiotherapy versus primary temozolomide chemotherapy in patients with low-grade glioma, and asses

  7. Construction aggregates

    Science.gov (United States)

    Nelson, T.I.; Bolen, W.P.

    2007-01-01

    Construction aggregates, primarily stone, sand and gravel, are recovered from widespread naturally occurring mineral deposits and processed for use primarily in the construction industry. They are mined, crushed, sorted by size and sold loose or combined with portland cement or asphaltic cement to make concrete products to build roads, houses, buildings, and other structures. Much smaller quantities are used in agriculture, cement manufacture, chemical and metallurgical processes, glass production and many other products.

  8. Recycled aggregates concrete: aggregate and mix properties

    Directory of Open Access Journals (Sweden)

    González-Fonteboa, B.

    2005-09-01

    Full Text Available This study of structural concrete made with recycled concrete aggregate focuses on two issues: 1. The characterization of such aggregate on the Spanish market. This involved conducting standard tests to determine density, water absorption, grading, shape, flakiness and hardness. The results obtained show that, despite the considerable differences with respect to density and water absorption between these and natural aggregates, on the whole recycled aggregate is apt for use in concrete production. 2. Testing to determine the values of basic concrete properties: mix design parameters were established for structural concrete in non-aggressive environments. These parameters were used to produce conventional concrete, and then adjusted to manufacture recycled concrete aggregate (RCA concrete, in which 50% of the coarse aggregate was replaced by the recycled material. Tests were conducted to determine the physical (density of the fresh and hardened material, water absorption and mechanical (compressive strength, splitting tensile strength and modulus of elasticity properties. The results showed that, from the standpoint of its physical and mechanical properties, concrete in which RCA accounted for 50% of the coarse aggregate compared favourably to conventional concrete.

    Se aborda el estudio de hormigones estructurales fabricados con áridos reciclados procedentes de hormigón, incidiéndose en dos aspectos: 1. Caracterización de tales áridos, procedentes del mercado español. Para ello se llevan a cabo ensayos de densidad, absorción, granulometría, coeficiente de forma, índice de lajas y dureza. Los resultados obtenidos han puesto de manifiesto que, a pesar de que existen diferencias notables (sobre todo en cuanto a densidad y absorción con los áridos naturales, las características de los áridos hacen posible la fabricación de hormigones. 2. Ensayos sobre propiedades básicas de los hormigones: se establecen parámetros de dosificaci

  9. Classroom: Efficient Grading

    Science.gov (United States)

    Shaw, David D.; Pease, Leonard F., III.

    2014-01-01

    Grading can be accelerated to make time for more effective instruction. This article presents specific time management strategies selected to decrease administrative time required of faculty and teaching assistants, including a multiple answer multiple choice interface for exams, a three-tier grading system for open ended problem solving, and a…

  10. Are grades really oppressive?

    Institute of Scientific and Technical Information of China (English)

    张心宇

    2015-01-01

    Are grades really oppressive? The broad question's answer is of course open: it varies in different condition and in prerequisites. Like in Daily Californian,"Why Grades are Oppressive", the title tells us it standing: yes, grades are oppressive. In the article, the authors (this article was written by 16 students of the class) pointed out that the grading system has had a violent and powerfully destructive effect on our lives. Because grading focuses our attention on class requirements that we have no say in determination. And this makes many students equate their self-worth with the grades they get in exams. Besides, grades are intimately connected with a larger system of control in community, which trains students to be submissive and not to question or challenge it. In the end, the authors conclude that they should take responsibility for evaluating their own learning process.

  11. Rucaparib in relapsed, platinum-sensitive high-grade ovarian carcinoma (ARIEL2 Part 1): an international, multicentre, open-label, phase 2 trial.

    Science.gov (United States)

    Swisher, Elizabeth M; Lin, Kevin K; Oza, Amit M; Scott, Clare L; Giordano, Heidi; Sun, James; Konecny, Gottfried E; Coleman, Robert L; Tinker, Anna V; O'Malley, David M; Kristeleit, Rebecca S; Ma, Ling; Bell-McGuinn, Katherine M; Brenton, James D; Cragun, Janiel M; Oaknin, Ana; Ray-Coquard, Isabelle; Harrell, Maria I; Mann, Elaina; Kaufmann, Scott H; Floquet, Anne; Leary, Alexandra; Harding, Thomas C; Goble, Sandra; Maloney, Lara; Isaacson, Jeff; Allen, Andrew R; Rolfe, Lindsey; Yelensky, Roman; Raponi, Mitch; McNeish, Iain A

    2017-01-01

    Poly(ADP-ribose) polymerase (PARP) inhibitors have activity in ovarian carcinomas with homologous recombination deficiency. Along with BRCA1 and BRCA2 (BRCA) mutations genomic loss of heterozygosity (LOH) might also represent homologous recombination deficiency. In ARIEL2, we assessed the ability of tumour genomic LOH, quantified with a next-generation sequencing assay, to predict response to rucaparib, an oral PARP inhibitor. ARIEL2 is an international, multicentre, two-part, phase 2, open-label study done at 49 hospitals and cancer centres in Australia, Canada, France, Spain, the UK, and the USA. In ARIEL2 Part 1, patients with recurrent, platinum-sensitive, high-grade ovarian carcinoma were classified into one of three predefined homologous recombination deficiency subgroups on the basis of tumour mutational analysis: BRCA mutant (deleterious germline or somatic), BRCA wild-type and LOH high (LOH high group), or BRCA wild-type and LOH low (LOH low group). We prespecified a cutoff of 14% or more genomic LOH for LOH high. Patients began treatment with oral rucaparib at 600 mg twice per day for continuous 28 day cycles until disease progression or any other reason for discontinuation. The primary endpoint was progression-free survival. All patients treated with at least one dose of rucaparib were included in the safety analyses and all treated patients who were classified were included in the primary endpoint analysis. This trial is registered with ClinicalTrials.gov, number NCT01891344. Enrolment into ARIEL2 Part 1 is complete, although an extension (Part 2) is ongoing. 256 patients were screened and 206 were enrolled between Oct 30, 2013, and Dec 19, 2014. At the data cutoff date (Jan 18, 2016), 204 patients had received rucaparib, with 28 patients remaining in the study. 192 patients could be classified into one of the three predefined homologous recombination deficiency subgroups: BRCA mutant (n=40), LOH high (n=82), or LOH low (n=70). Tumours from 12 patients

  12. Oil-Price Shocks: Beyond Standard Aggregate Demand/Aggregate Supply Analysis.

    Science.gov (United States)

    Elwood, S. Kirk

    2001-01-01

    Explores the problems of portraying oil-price shocks using the aggregate demand/aggregate supply model. Presents a simple modification of the model that differentiates between production and absorption of goods, which enables it to better reflect the effects of oil-price shocks on open economies. (RLH)

  13. Anchorage of Main Reinforcement in Lightweight Aggregate Concrete Beams

    DEFF Research Database (Denmark)

    Larsen, Henning

    1999-01-01

    The paper deals with the anchorage of reinforcement bars at end supports in beam component made of lightweight aggregate concrete with open structure.......The paper deals with the anchorage of reinforcement bars at end supports in beam component made of lightweight aggregate concrete with open structure....

  14. The Proportion of Chromatin Graded between Closed and Open States Determines the Level of Transcripts Derived from Distinct Promoters in the CYP19 Gene.

    Science.gov (United States)

    Kotomura, Naoe; Harada, Nobuhiro; Ishihara, Satoru

    2015-01-01

    The human CYP19 gene encodes aromatase, which converts androgens to estrogens. CYP19 mRNA variants are transcribed mainly from three promoters. Quantitative RT-PCR was used to measure the relative amounts of each of the three transcripts and determine the on/off state of the promoters. While some of the promoters were silent, CYP19 mRNA production differed among the other promoters, whose estimated transcription levels were 0.001% to 0.1% of that of the TUBB control gene. To investigate the structural aspects of chromatin that were responsible for this wide range of activity of the CYP19 promoters, we used a fractionation protocol, designated SEVENS, which sequentially separates densely packed nucleosomes from dispersed nucleosomes. The fractional distribution of each inactive promoter showed a similar pattern to that of the repressed reference loci; the inactive regions were distributed toward lower fractions, in which closed chromatin comprising packed nucleosomes was enriched. In contrast, active CYP19 promoters were raised toward upper fractions, including dispersed nucleosomes in open chromatin. Importantly, these active promoters were moderately enriched in the upper fractions as compared to active reference loci, such as the TUBB promoter; the proportion of open chromatin appeared to be positively correlated to the promoter strength. These results, together with ectopic transcription accompanied by an increase in the proportion of open chromatin in cells treated with an H3K27me inhibitor, indicate that CYP19 mRNA could be transcribed from a promoter in which chromatin is shifted toward an open state in the equilibrium between closed and open chromatin.

  15. Distinguishing aggregate formation and aggregate clearance using cell based assays

    NARCIS (Netherlands)

    E. Eenjes, E.; J.M. Dragich; H. Kampinga (Harm); A. Yamamoto, A.

    2016-01-01

    textabstractThe accumulation of ubiquitinated proteinaceous inclusions represents a complex process, reflecting the disequilibrium between aggregate formation and aggregate clearance. Although decreasing aggregate formation or augmenting aggregate clearance will ultimately lead to diminished aggrega

  16. Perspectives on Preference Aggregation.

    Science.gov (United States)

    Regenwetter, Michel

    2009-07-01

    For centuries, the mathematical aggregation of preferences by groups, organizations, or society itself has received keen interdisciplinary attention. Extensive theoretical work in economics and political science throughout the second half of the 20th century has highlighted the idea that competing notions of rational social choice intrinsically contradict each other. This has led some researchers to consider coherent democratic decision making to be a mathematical impossibility. Recent empirical work in psychology qualifies that view. This nontechnical review sketches a quantitative research paradigm for the behavioral investigation of mathematical social choice rules on real ballots, experimental choices, or attitudinal survey data. The article poses a series of open questions. Some classical work sometimes makes assumptions about voter preferences that are descriptively invalid. Do such technical assumptions lead the theory astray? How can empirical work inform the formulation of meaningful theoretical primitives? Classical "impossibility results" leverage the fact that certain desirable mathematical properties logically cannot hold in all conceivable electorates. Do these properties nonetheless hold true in empirical distributions of preferences? Will future behavioral analyses continue to contradict the expectations of established theory? Under what conditions do competing consensus methods yield identical outcomes and why do they do so?

  17. Temporal aggregation in first order cointegrated vector autoregressive

    DEFF Research Database (Denmark)

    la Cour, Lisbeth Funding; Milhøj, Anders

    2006-01-01

    We study aggregation - or sample frequencies - of time series, e.g. aggregation from weekly to monthly or quarterly time series. Aggregation usually gives shorter time series but spurious phenomena, in e.g. daily observations, can on the other hand be avoided. An important issue is the effect of ...... of aggregation on the adjustment coefficient in cointegrated systems. We study only first order vector autoregressive processes for n dimensional time series Xt, and we illustrate the theory by a two dimensional and a four dimensional model for prices of various grades of gasoline....

  18. Temporal aggregation in first order cointegrated vector autoregressive models

    DEFF Research Database (Denmark)

    La Cour, Lisbeth Funding; Milhøj, Anders

    We study aggregation - or sample frequencies - of time series, e.g. aggregation from weekly to monthly or quarterly time series. Aggregation usually gives shorter time series but spurious phenomena, in e.g. daily observations, can on the other hand be avoided. An important issue is the effect of ...... of aggregation on the adjustment coefficient in cointegrated systems. We study only first order vector autoregressive processes for n dimensional time series Xt, and we illustrate the theory by a two dimensional and a four dimensional model for prices of various grades of gasoline...

  19. Aggregation of estimated numbers of undiscovered deposits: an R-script with an example from the Chu Sarysu Basin, Kazakhtan: Chapter B in Global mineral resource assessment

    Science.gov (United States)

    Schuenemeyer, John H.; Zientek, Michael L.; Box, Stephen E.

    2011-01-01

    Mineral resource assessments completed by the U.S. Geological Survey during the past three decades express geologically based estimates of numbers of undiscovered mineral deposits as probability distributions. Numbers of undiscovered deposits of a given type are estimated in geologically defined regions. Using Monte Carlo simulations, these undiscovered deposit estimates are combined with tonnage and grade models to derive a probability distribution describing amounts of commodities and rock that could be present in undiscovered deposits within a study area. In some situations, it is desirable to aggregate the assessment results from several study areas. This report provides a script developed in open-source statistical software, R, that aggregates undiscovered deposit estimates of a given type, assuming independence, total dependence, or some degree of correlation among aggregated areas, given a user-specified correlation matrix.

  20. Carrier-Grade Distributed Open Cloud Computing for Telecom Operators%电信运营商分布式开放云计算

    Institute of Scientific and Technical Information of China (English)

    王大鹏; 邢凯; 孙家飞

    2013-01-01

    This paper researches how to develop cloud computing services for telecom operators, points out the change of business model of operators during the process of cloud computing evolution, analyzes chal enges and needs for operators level cloud computing, designs operators level distributed open cloud computing system structure, and puts forward the selection of the software and hardware, distributed deployment method, operation and service mode of some typical operators level cloud computing center construction process. Final y, it summarizes the operators level cloud computing platform construction step, and puts forward the evolution direction of platform system architecture and combination of user experience and internet of things cloud computing.%  文章针对电信运营商如何开展云计算服务进行了研究,指出运营商向云计算演进过程中商业模式的变化,分析运营商级云计算面临的挑战和需求,设计运营商级分布式开放云计算的系统架构。并提出典型运营商级云计算中心搭建过程中的软硬件选择、分布式部署方法、运营与服务提供模式。最后总结了运营商级云计算平台建设步骤,提出平台系统架构、用户体验和物联网云计算结合方面的演进方向。

  1. Aggregations in Flatworms.

    Science.gov (United States)

    Liffen, C. L.; Hunter, M.

    1980-01-01

    Described is a school project to investigate aggregations in flatworms which may be influenced by light intensity, temperature, and some form of chemical stimulus released by already aggregating flatworms. Such investigations could be adopted to suit many educational levels of science laboratory activities. (DS)

  2. Platelet activation and aggregation

    DEFF Research Database (Denmark)

    Jensen, Maria Sander; Larsen, O H; Christiansen, Kirsten

    2013-01-01

    This study introduces a new laboratory model of whole blood platelet aggregation stimulated by endogenously generated thrombin, and explores this aspect in haemophilia A in which impaired thrombin generation is a major hallmark. The method was established to measure platelet aggregation initiated...

  3. Aggregates from mineral wastes

    Directory of Open Access Journals (Sweden)

    Baic Ireneusz

    2016-01-01

    Full Text Available The problem concerning the growing demand for natural aggregates and the need to limit costs, including transportation from remote deposits, cause the increase in growth of interest in aggregates from mineral wastes as well as in technologies of their production and recovery. The paper presents the issue related to the group of aggregates other than natural. A common name is proposed for such material: “alternative aggregates”. The name seems to be fully justified due to adequacy of this term because of this raw materials origin and role, in comparison to the meaning of natural aggregates based on gravel and sand as well as crushed stones. The paper presents characteristics of the market and basic application of aggregates produced from mineral wastes, generated in the mining, power and metallurgical industries as well as material from demolished objects.

  4. Marine Synechococcus Aggregation

    Science.gov (United States)

    Neuer, S.; Deng, W.; Cruz, B. N.; Monks, L.

    2016-02-01

    Cyanobacteria are considered to play an important role in the oceanic biological carbon pump, especially in oligotrophic regions. But as single cells are too small to sink, their carbon export has to be mediated by aggregate formation and possible consumption by zooplankton producing sinking fecal pellets. Here we report results on the aggregation of the ubiquitous marine pico-cyanobacterium Synechococcus as a model organism. We first investigated the mechanism behind such aggregation by studying the potential role of transparent exopolymeric particles (TEP) and the effects of nutrient (nitrogen or phosphorus) limitation on the TEP production and aggregate formation of these pico-cyanobacteria. We further studied the aggregation and subsequent settling in roller tanks and investigated the effects of the clays kaolinite and bentonite in a series of concentrations. Our results show that despite of the lowered growth rates, Synechococcus in nutrient limited cultures had larger cell-normalized TEP production, formed a greater volume of aggregates, and resulted in higher settling velocities compared to results from replete cultures. In addition, we found that despite their small size and lack of natural ballasting minerals, Synechococcus cells could still form aggregates and sink at measureable velocities in seawater. Clay minerals increased the number and reduced the size of aggregates, and their ballasting effects increased the sinking velocity and carbon export potential of aggregates. In comparison with the Synechococcus, we will also present results of the aggregation of the pico-cyanobacterium Prochlorococcus in roller tanks. These results contribute to our understanding in the physiology of marine Synechococcus as well as their role in the ecology and biogeochemistry in oligotrophic oceans.

  5. Lightweight Aggregate Concrete Beams. Load-bearing Capacity

    DEFF Research Database (Denmark)

    Larsen, Henning; Goltermann, Per; Ingholt, N.U.

    1997-01-01

    This paper deals with the load-bearing capacity of reinforced beams made of lightweight aggregate concrete with open structure and documents formulas for the moment capacity as well as the shear force capacity.......This paper deals with the load-bearing capacity of reinforced beams made of lightweight aggregate concrete with open structure and documents formulas for the moment capacity as well as the shear force capacity....

  6. Lightweight Aggregate Concrete Components. Load-bearing Capacity

    DEFF Research Database (Denmark)

    Larsen, Henning; Ingholt, N.U.; Goltermann, Per

    1996-01-01

    The project presented here deals with the load-bearing capacity of reinforced beams made of lightweight aggregate concrete with open structure and documents expressions for the moment capacity as well as the shear force capacity......The project presented here deals with the load-bearing capacity of reinforced beams made of lightweight aggregate concrete with open structure and documents expressions for the moment capacity as well as the shear force capacity...

  7. Stone Matrix Asphalt (SMA is a gap-graded mix that is gaining popularity worldwide. Generally, gap graded mixes are thought to be weak in fatigue resistance. In this study, cellulose fibers were pre-blended in PG64-22 binder with fiber proportions of 0.2%, 0.4%, 0.6%, 0.8% and 1.0% by weight of aggregates. The fiber-modified binder showed improved rheological properties and showed that the PG64-22 binder can be modified and raised to PG70-22 grade. The cellulose oil palm fiber (COPF was found to improve the diameteral fatigue performance of SMA design mix. The fatigue life increased to a maximum at a fiber content of about 0.6%, whilst the tensile stress and stiffness also showed a similar trend in performance. The initial strains of the mix were lowest at a fiber content of 0.6%.

    Directory of Open Access Journals (Sweden)

    Ratnasamy Muniandy

    2006-01-01

    Full Text Available Stone Matrix Asphalt (SMA is a gap-graded mix that is gaining popularity worldwide. Generally, gap graded mixes are thought to be weak in fatigue resistance. In this study, cellulose fibers were pre-blended in PG64-22 binder with fiber proportions of 0.2%, 0.4%, 0.6%, 0.8% and 1.0% by weight of aggregates. The fiber-modified binder showed improved rheological properties and showed that the PG64-22 binder can be modified and raised to PG70-22 grade. The cellulose oil palm fiber (COPF was found to improve the diameteral fatigue performance of SMA design mix. The fatigue life increased to a maximum at a fiber content of about 0.6%, whilst the tensile stress and stiffness also showed a similar trend in performance. The initial strains of the mix were lowest at a fiber content of 0.6%.

  8. Protein aggregate myopathies

    Directory of Open Access Journals (Sweden)

    Sharma M

    2005-01-01

    Full Text Available Protein aggregate myopathies (PAM are an emerging group of muscle diseases characterized by structural abnormalities. Protein aggregate myopathies are marked by the aggregation of intrinsic proteins within muscle fibers and fall into four major groups or conditions: (1 desmin-related myopathies (DRM that include desminopathies, a-B crystallinopathies, selenoproteinopathies caused by mutations in the, a-B crystallin and selenoprotein N1 genes, (2 hereditary inclusion body myopathies, several of which have been linked to different chromosomal gene loci, but with as yet unidentified protein product, (3 actinopathies marked by mutations in the sarcomeric ACTA1 gene, and (4 myosinopathy marked by a mutation in the MYH-7 gene. While PAM forms 1 and 2 are probably based on impaired extralysosomal protein degradation, resulting in the accumulation of numerous and diverse proteins (in familial types in addition to respective mutant proteins, PAM forms 3 and 4 may represent anabolic or developmental defects because of preservation of sarcomeres outside of the actin and myosin aggregates and dearth or absence of other proteins in these actin or myosin aggregates, respectively. The pathogenetic principles governing protein aggregation within muscle fibers and subsequent structural sarcomeres are still largely unknown in both the putative catabolic and anabolic forms of PAM. Presence of inclusions and their protein composition in other congenital myopathies such as reducing bodies, cylindrical spirals, tubular aggregates and others await clarification. The hitherto described PAMs were first identified by immunohistochemistry of proteins and subsequently by molecular analysis of their genes.

  9. Charged Dust Aggregate Interactions

    Science.gov (United States)

    Matthews, Lorin; Hyde, Truell

    2015-11-01

    A proper understanding of the behavior of dust particle aggregates immersed in a complex plasma first requires a knowledge of the basic properties of the system. Among the most important of these are the net electrostatic charge and higher multipole moments on the dust aggregate as well as the manner in which the aggregate interacts with the local electrostatic fields. The formation of elongated, fractal-like aggregates levitating in the sheath electric field of a weakly ionized RF generated plasma discharge has recently been observed experimentally. The resulting data has shown that as aggregates approach one another, they can both accelerate and rotate. At equilibrium, aggregates are observed to levitate with regular spacing, rotating about their long axis aligned parallel to the sheath electric field. Since gas drag tends to slow any such rotation, energy must be constantly fed into the system in order to sustain it. A numerical model designed to analyze this motion provides both the electrostatic charge and higher multipole moments of the aggregate while including the forces due to thermophoresis, neutral gas drag, and the ion wakefield. This model will be used to investigate the ambient conditions leading to the observed interactions. This research is funded by NSF Grant 1414523.

  10. Tumor Grade

    Science.gov (United States)

    ... Other Funding Find NCI funding for small business innovation, technology transfer, and contracts Training Cancer Training at ... much of the tumor tissue has normal breast (milk) duct structures Nuclear grade : an evaluation of the ...

  11. Aggregated Computational Toxicology Online Resource

    Data.gov (United States)

    U.S. Environmental Protection Agency — Aggregated Computational Toxicology Online Resource (AcTOR) is EPA's online aggregator of all the public sources of chemical toxicity data. ACToR aggregates data...

  12. Protein Colloidal Aggregation Project

    Science.gov (United States)

    Oliva-Buisson, Yvette J. (Compiler)

    2014-01-01

    To investigate the pathways and kinetics of protein aggregation to allow accurate predictive modeling of the process and evaluation of potential inhibitors to prevalent diseases including cataract formation, chronic traumatic encephalopathy, Alzheimer's Disease, Parkinson's Disease and others.

  13. Propagation of Tau aggregates.

    Science.gov (United States)

    Goedert, Michel; Spillantini, Maria Grazia

    2017-05-30

    Since 2009, evidence has accumulated to suggest that Tau aggregates form first in a small number of brain cells, from where they propagate to other regions, resulting in neurodegeneration and disease. Propagation of Tau aggregates is often called prion-like, which refers to the capacity of an assembled protein to induce the same abnormal conformation in a protein of the same kind, initiating a self-amplifying cascade. In addition, prion-like encompasses the release of protein aggregates from brain cells and their uptake by neighbouring cells. In mice, the intracerebral injection of Tau inclusions induced the ordered assembly of monomeric Tau, followed by its spreading to distant brain regions. Short fibrils constituted the major species of seed-competent Tau. The existence of several human Tauopathies with distinct fibril morphologies has led to the suggestion that different molecular conformers (or strains) of aggregated Tau exist.

  14. Aggregation and Averaging.

    Science.gov (United States)

    Siegel, Irving H.

    The arithmetic processes of aggregation and averaging are basic to quantitative investigations of employment, unemployment, and related concepts. In explaining these concepts, this report stresses need for accuracy and consistency in measurements, and describes tools for analyzing alternative measures. (BH)

  15. Cell aggregation and sedimentation.

    Science.gov (United States)

    Davis, R H

    1995-01-01

    The aggregation of cells into clumps or flocs has been exploited for decades in such applications as biological wastewater treatment, beer brewing, antibiotic fermentation, and enhanced sedimentation to aid in cell recovery or retention. More recent research has included the use of cell aggregation and sedimentation to selectively separate subpopulations of cells. Potential biotechnological applications include overcoming contamination, maintaining plasmid-bearing cells in continuous fermentors, and selectively removing nonviable hybridoma cells from perfusion cultures.

  16. Open-Graded Bases for Airfield Pavements.

    Science.gov (United States)

    1987-07-01

    pressure. 7. The rapid drainage of the bases is particularly important for rigid pavement to prevent pumping at the joints. Cedergren (1974) was a particu...filter cloth, collector trenches or perforated collector pipe, pipe outlets, and outlet markers. 11. From the studies by Cedergren , Rollings, and...paper No. 2516, American Society of Civil Engineers, New York. Cedergren , H. R. 1974a. Drainage of Highway and Airfield Pavements, John Wiley and Sons

  17. Optical dynamics of molecular aggregates

    NARCIS (Netherlands)

    de Boer, Steven

    2006-01-01

    The subject of this thesis is the spectroscopy and dynamics of molecular aggregates in amorphous matrices. Aggregates of three different molecules were studied. The molecules are depicted in Fig. (1.1). Supersaturated solutions of these molecules show aggregate formation. Aggregation is a process si

  18. Observing Convective Aggregation

    Science.gov (United States)

    Holloway, Christopher E.; Wing, Allison A.; Bony, Sandrine; Muller, Caroline; Masunaga, Hirohiko; L'Ecuyer, Tristan S.; Turner, David D.; Zuidema, Paquita

    2017-06-01

    Convective self-aggregation, the spontaneous organization of initially scattered convection into isolated convective clusters despite spatially homogeneous boundary conditions and forcing, was first recognized and studied in idealized numerical simulations. While there is a rich history of observational work on convective clustering and organization, there have been only a few studies that have analyzed observations to look specifically for processes related to self-aggregation in models. Here we review observational work in both of these categories and motivate the need for more of this work. We acknowledge that self-aggregation may appear to be far-removed from observed convective organization in terms of time scales, initial conditions, initiation processes, and mean state extremes, but we argue that these differences vary greatly across the diverse range of model simulations in the literature and that these comparisons are already offering important insights into real tropical phenomena. Some preliminary new findings are presented, including results showing that a self-aggregation simulation with square geometry has too broad distribution of humidity and is too dry in the driest regions when compared with radiosonde records from Nauru, while an elongated channel simulation has realistic representations of atmospheric humidity and its variability. We discuss recent work increasing our understanding of how organized convection and climate change may interact, and how model discrepancies related to this question are prompting interest in observational comparisons. We also propose possible future directions for observational work related to convective aggregation, including novel satellite approaches and a ground-based observational network.

  19. Comparison of MAPIE versus MAP in patients with a poor response to preoperative chemotherapy for newly diagnosed high-grade osteosarcoma (EURAMOS-1): an open-label, international, randomised controlled trial.

    Science.gov (United States)

    Marina, Neyssa M; Smeland, Sigbjørn; Bielack, Stefan S; Bernstein, Mark; Jovic, Gordana; Krailo, Mark D; Hook, Jane M; Arndt, Carola; van den Berg, Henk; Brennan, Bernadette; Brichard, Bénédicte; Brown, Ken L B; Butterfass-Bahloul, Trude; Calaminus, Gabriele; Daldrup-Link, Heike E; Eriksson, Mikael; Gebhardt, Mark C; Gelderblom, Hans; Gerss, Joachim; Goldsby, Robert; Goorin, Allen; Gorlick, Richard; Grier, Holcombe E; Hale, Juliet P; Hall, Kirsten Sundby; Hardes, Jendrik; Hawkins, Douglas S; Helmke, Knut; Hogendoorn, Pancras C W; Isakoff, Michael S; Janeway, Katherine A; Jürgens, Heribert; Kager, Leo; Kühne, Thomas; Lau, Ching C; Leavey, Patrick J; Lessnick, Stephen L; Mascarenhas, Leo; Meyers, Paul A; Mottl, Hubert; Nathrath, Michaela; Papai, Zsuzsanna; Randall, R Lor; Reichardt, Peter; Renard, Marleen; Safwat, Akmal Ahmed; Schwartz, Cindy L; Stevens, Michael C G; Strauss, Sandra J; Teot, Lisa; Werner, Mathias; Sydes, Matthew R; Whelan, Jeremy S

    2016-10-01

    We designed the EURAMOS-1 trial to investigate whether intensified postoperative chemotherapy for patients whose tumour showed a poor response to preoperative chemotherapy (≥10% viable tumour) improved event-free survival in patients with high-grade osteosarcoma. EURAMOS-1 was an open-label, international, phase 3 randomised, controlled trial. Consenting patients with newly diagnosed, resectable, high-grade osteosarcoma aged 40 years or younger were eligible for randomisation. Patients were randomly assigned (1:1) to receive either postoperative cisplatin, doxorubicin, and methotrexate (MAP) or MAP plus ifosfamide and etoposide (MAPIE) using concealed permuted blocks with three stratification factors: trial group; location of tumour (proximal femur or proximal humerus vs other limb vs axial skeleton); and presence of metastases (no vs yes or possible). The MAP regimen consisted of cisplatin 120 mg/m(2), doxorubicin 37·5 mg/m(2) per day on days 1 and 2 (on weeks 1 and 6) followed 3 weeks later by high-dose methotrexate 12 g/m(2) over 4 h. The MAPIE regimen consisted of MAP as a base regimen, with the addition of high-dose ifosfamide (14 g/m(2)) at 2·8 g/m(2) per day with equidose mesna uroprotection, followed by etoposide 100 mg/m(2) per day over 1 h on days 1-5. The primary outcome measure was event-free survival measured in the intention-to-treat population. This trial is registered with ClinicalTrials.gov, number NCT00134030. Between April 14, 2005, and June 30, 2011, 2260 patients were registered from 325 sites in 17 countries. 618 patients with poor response were randomly assigned; 310 to receive MAP and 308 to receive MAPIE. Median follow-up was 62·1 months (IQR 46·6-76·6); 62·3 months (IQR 46·9-77·1) for the MAP group and 61·1 months (IQR 46·5-75·3) for the MAPIE group. 307 event-free survival events were reported (153 in the MAP group vs 154 in the MAPIE group). 193 deaths were reported (101 in the MAP group vs 92 in the MAPIE group). Event

  20. The Open Access Divide

    Directory of Open Access Journals (Sweden)

    Jingfeng Xia

    2013-10-01

    Full Text Available This paper is an attempt to review various aspects of the open access divide regarding the difference between those academics who support free sharing of data and scholarly output and those academics who do not. It provides a structured description by adopting the Ws doctrines emphasizing such questions as who, what, when, where and why for information-gathering. Using measurable variables to define a common expression of the open access divide, this study collects aggregated data from existing open access as well as non-open access publications including journal articles and extensive reports. The definition of the open access divide is integrated into the discussion of scholarship on a larger scale.

  1. Fractals of Silica Aggregates

    Institute of Scientific and Technical Information of China (English)

    ZhinhongLi; DongWu; Yuhansun; JunWang; YiLiu; BaozhongDong; Zhinhong

    2001-01-01

    Silica aggregates were prepared by base-catalyzed hydrolysis and condensation of alkoxides in alcohol.Polyethylene glycol(PEG) was used as organic modifier.The sols were characterized using Small Angle X-ray Scattering (SAXS) with synchrotron radiation as X-ray source.The structure evolution during the sol-gel process was determined and described in terms of the fractal geometry.As-produced silica aggregates were found to be mass fractals.The fractl dimensions spanned the regime 2.1-2.6 corresponding to more branched and compact structures.Both RLCA and Eden models dominated the kinetic growth under base-catalyzed condition.

  2. Grading Student Writing: An Experiment and a Commentary.

    Science.gov (United States)

    Sommers, Jeffrey

    1993-01-01

    Uses a student essay and dialog journal entries to discuss problems raised by context in grading student writing. Encourages teachers to rethink the whole system of grading and to discuss their conclusions openly. (SR)

  3. Aggregate packing characteristics of good and poor performing asphalt mixes

    CSIR Research Space (South Africa)

    Denneman, E

    2007-07-01

    Full Text Available The aggregate structure of the compacted mix is a determining factor for the performance of Hot-Mix Asphalt (HMA). In this paper, the grading characteristics of good and poor performing HMA mixes are explored using the concepts of the Bailey method...

  4. Geoinformation Generalization by Aggregation

    Directory of Open Access Journals (Sweden)

    Tomislav Jogun

    2016-12-01

    Full Text Available Geoinformation generalization can be divided into model generalization and cartographic generalization. Model generalization is the supervised reduction of data in a model, while cartographic generalization is the reduction of the complexity of map content adapted to the map scale, and/or use by various generalization operators (procedures. The topic of this paper is the aggregation of geoinformation. Generally, aggregation is the joining of nearby, congenial objects, when the distance between them is smaller than the minimum sizes. Most researchers in geoinformation generalization have focused on line features. However, the appearance of web-maps with point features and choropleth maps has led to the development of concepts and algorithms for the generalization of point and polygonal features. This paper considers some previous theoretical premises and actual examples of aggregation for point, line and polygonal features. The algorithms for aggregation implemented in commercial and free GIS software were tested. In the conclusion, unresolved challenges that occur in dynamic cartographic visualizations and cases of unusual geometrical features are highlighted.

  5. Erosion of dust aggregates

    CERN Document Server

    Seizinger, Alexander; Kley, Wilhelm

    2013-01-01

    Aims: The aim of this work is to gain a deeper insight into how much different aggregate types are affected by erosion. Especially, it is important to study the influence of the velocity of the impacting projectiles. We also want to provide models for dust growth in protoplanetary disks with simple recipes to account for erosion effects. Methods: To study the erosion of dust aggregates we employed a molecular dynamics approach that features a detailed micro-physical model of the interaction of spherical grains. For the first time, the model has been extended by introducing a new visco-elastic damping force which requires a proper calibration. Afterwards, different sample generation methods were used to cover a wide range of aggregate types. Results: The visco-elastic damping force introduced in this work turns out to be crucial to reproduce results obtained from laboratory experiments. After proper calibration, we find that erosion occurs for impact velocities of 5 m/s and above. Though fractal aggregates as ...

  6. Diffusion in aggregated soil.

    NARCIS (Netherlands)

    Rappoldt, C.

    1992-01-01

    The structure of an aggregated soil is characterized by the distribution of the distance from an arbitrary point in the soil to the nearest macropore or crack. From this distribution an equivalent model system is derived to which a diffusion model can be more easily applied. The model system consist

  7. Brittleness Generation Mechanism and Failure Model of High Strength Lightweight Aggregate Concrete

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    The brittleness generation mechanism of high strength lightweight aggregate concrete(HSLWAC) was presented, and it was indicated that lightweight aggregate was the vulnerable spot,initiating brittleness. Based on the analysis of the brittleness failure by the load-deflection curve, the brittleness presented by HSLWAC was more prominent compared with ordinary lightweight aggregate concrete of the same strength grade. The model of brittleness failure was also established.

  8. Graded Response Modeling of the Quality of Life Interview.

    Science.gov (United States)

    Uttaro, Thomas; Lehman, Anthony

    1999-01-01

    Outlined a graded response model and applied it to an aggregated data set from four studies involving subjective items from the Quality of Life Interview (QOLI) (A. Lehman, 1988). Used the results to create customized QOLI scales. Discusses the use of this methodology for scales involving ordered, graded categories. (SLD)

  9. Combined research effort on aggregate road materials

    Science.gov (United States)

    Kuznetsova, Elena; Hoff, Inge; Willy Danielsen, Svein; Wigum, Børge Johannes; Fladvad, Marit; Rieksts, Karlis; Loranger, Benoit; Barbieri, Diego

    2017-04-01

    ) mechanical and c) thermal properties, and d) frost action and susceptibility. The main goal of the PhD topic N1 is to achieve better utilization of aggregate resources through adjusting the production process according to local geological conditions and construction needs. The objective of the PhD project N2 is to look at the design stage and find the way to use these aggregates anyway by changing the road's design (e.g. increasing the thickness of asphalt layer). Fine particles content will also be harder to control due to rock type variability from site to site. Thus, PhD project N3 is going to investigate the effect of the increasing of fines and their mineralogy on frost action related problems during freezing and thawing seasons. Finally, PhD project N4 is investigating how the grading and mineralogy of the crushed rock material affects the heat exchange in road's granular layers and consequently, the frost penetration depth. Combining these PhD studies we aim to create a holistic approach for a new understanding within this very complex area.

  10. Graded Syzygies

    CERN Document Server

    Peeva, Irena

    2011-01-01

    The study of free resolutions is a core and beautiful area in Commutative Algebra. The main goal of this book is to inspire the readers and develop their intuition about syzygies and Hilbert functions. Many examples are given in order to illustrate ideas and key concepts. A valuable feature of the book is the inclusion of open problems and conjectures; these provide a glimpse of exciting, and often challenging, research directions in the field. Three types of problems are presented: Conjectures, Problems, and Open-Ended Problems. The latter do not describe specific problems but point to intere

  11. p53 protein aggregation promotes platinum resistance in ovarian cancer.

    Science.gov (United States)

    Yang-Hartwich, Y; Soteras, M G; Lin, Z P; Holmberg, J; Sumi, N; Craveiro, V; Liang, M; Romanoff, E; Bingham, J; Garofalo, F; Alvero, A; Mor, G

    2015-07-01

    High-grade serous ovarian carcinoma (HGSOC), the most lethal gynecological cancer, often leads to chemoresistant diseases. The p53 protein is a key transcriptional factor regulating cellular homeostasis. A majority of HGSOCs have inactive p53 because of genetic mutations. However, genetic mutation is not the only cause of p53 inactivation. The aggregation of p53 protein has been discovered in different types of cancers and may be responsible for impairing the normal transcriptional activation and pro-apoptotic functions of p53. We demonstrated that in a unique population of HGSOC cancer cells with cancer stem cell properties, p53 protein aggregation is associated with p53 inactivation and platinum resistance. When these cancer stem cells differentiated into their chemosensitive progeny, they lost tumor-initiating capacity and p53 aggregates. In addition to the association of p53 aggregation and chemoresistance in HGSOC cells, we further demonstrated that the overexpression of a p53-positive regulator, p14ARF, inhibited MDM2-mediated p53 degradation and led to the imbalance of p53 turnover that promoted the formation of p53 aggregates. With in vitro and in vivo models, we demonstrated that the inhibition of p14ARF could suppress p53 aggregation and sensitize cancer cells to platinum treatment. Moreover, by two-dimensional gel electrophoresis and mass spectrometry we discovered that the aggregated p53 may function uniquely by interacting with proteins that are critical for cancer cell survival and tumor progression. Our findings help us understand the poor chemoresponse of a subset of HGSOC patients and suggest p53 aggregation as a new marker for chemoresistance. Our findings also suggest that inhibiting p53 aggregation can reactivate p53 pro-apoptotic function. Therefore, p53 aggregation is a potential therapeutic target for reversing chemoresistance. This is paramount for improving ovarian cancer patients' responses to chemotherapy, and thus increasing their

  12. Proteins aggregation and human diseases

    Science.gov (United States)

    Hu, Chin-Kun

    2015-04-01

    Many human diseases and the death of most supercentenarians are related to protein aggregation. Neurodegenerative diseases include Alzheimer's disease (AD), Huntington's disease (HD), Parkinson's disease (PD), frontotemporallobar degeneration, etc. Such diseases are due to progressive loss of structure or function of neurons caused by protein aggregation. For example, AD is considered to be related to aggregation of Aβ40 (peptide with 40 amino acids) and Aβ42 (peptide with 42 amino acids) and HD is considered to be related to aggregation of polyQ (polyglutamine) peptides. In this paper, we briefly review our recent discovery of key factors for protein aggregation. We used a lattice model to study the aggregation rates of proteins and found that the probability for a protein sequence to appear in the conformation of the aggregated state can be used to determine the temperature at which proteins can aggregate most quickly. We used molecular dynamics and simple models of polymer chains to study relaxation and aggregation of proteins under various conditions and found that when the bending-angle dependent and torsion-angle dependent interactions are zero or very small, then protein chains tend to aggregate at lower temperatures. All atom models were used to identify a key peptide chain for the aggregation of insulin chains and to find that two polyQ chains prefer anti-parallel conformation. It is pointed out that in many cases, protein aggregation does not result from protein mis-folding. A potential drug from Chinese medicine was found for Alzheimer's disease.

  13. Investigation of Usability as Aggregate of Different Originated Rocks

    Science.gov (United States)

    Başpinar Tuncay, Ebru; Kilinçarslan, Şemsettin; Yağmurlu, Fuzuli

    2016-10-01

    The general properties of aggregate can determine the performance and durability of the concrete. In this study, mineralogical, petrographic, mechanical, physical and chemical properties of the rock samples of different origin (limestone, recrystallized limestone, dolomite, sand and gravel, tephra-phonolite, trachybasalt) were determined. Samples were obtained from different origin rocks units and they have been classified in three different sizes of aggregate with crushing and screening method. Grading, classification of particle, loose bulk density, water absorption ratio, flakiness index, coefficient of Los Angeles, resistance to freeze-loosening and alkali-silica reaction of aggregates and organic matter determination has been determined. The rocks have been investigated in compliance with the relevant standards. Trachybasalt and dolomite have higher particle density than other rocks. In addition, strength and flexural strength of these rocks are higher than other rocks. Tephra-phonolite has the lowest water absorption rate. At the same time resistance to freeze loosening of Tephra- phonolite is lower than the other rocks. Resistance to fragmentation and the resistance to wear of all of rocks are quite high. Sand and gravel, tephra-phonolite and trachybasalt are evaluated in terms of alkali-silica reaction. Sand and gravel are more reactive than the other aggregates. Organic matter content of the aggregates is low for the quality of aggregate. Also high correlation between some properties of aggregates was observed. For example, high correlation between compressive strength and flexural strength, water absorption and porosity, resistance to fragmentation and the resistance to ware (Micro-Deval).

  14. OpenSHS: Open Smart Home Simulator

    Directory of Open Access Journals (Sweden)

    Nasser Alshammari

    2017-05-01

    Full Text Available This paper develops a new hybrid, open-source, cross-platform 3D smart home simulator, OpenSHS, for dataset generation. OpenSHS offers an opportunity for researchers in the field of the Internet of Things (IoT and machine learning to test and evaluate their models. Following a hybrid approach, OpenSHS combines advantages from both interactive and model-based approaches. This approach reduces the time and efforts required to generate simulated smart home datasets. We have designed a replication algorithm for extending and expanding a dataset. A small sample dataset produced, by OpenSHS, can be extended without affecting the logical order of the events. The replication provides a solution for generating large representative smart home datasets. We have built an extensible library of smart devices that facilitates the simulation of current and future smart home environments. Our tool divides the dataset generation process into three distinct phases: first design: the researcher designs the initial virtual environment by building the home, importing smart devices and creating contexts; second, simulation: the participant simulates his/her context-specific events; and third, aggregation: the researcher applies the replication algorithm to generate the final dataset. We conducted a study to assess the ease of use of our tool on the System Usability Scale (SUS.

  15. Improving Grading Consistency through Grade Lift Reporting

    Science.gov (United States)

    Millet, Ido

    2010-01-01

    We define Grade Lift as the difference between average class grade and average cumulative class GPA. This metric provides an assessment of how lenient the grading was for a given course. In 2006, we started providing faculty members individualized Grade Lift reports reflecting their position relative to an anonymously plotted school-wide…

  16. Determination of appropriate mix ratios for concrete grades using Nigerian Portland-limestone grades 32.5 and 42.5

    Directory of Open Access Journals (Sweden)

    Kazeem Kayode ADEWOLE

    2015-05-01

    Full Text Available The construction of buildings by incompetent craftsmen and the use of low quality building materials, including low quality concrete have been identified in the literature as two of the major reasons for the incessant collapse of building in Nigeria. The roadside craftsmen/artisans usually/generally construct buildings using 1:2:4 cement-fine aggregate-large aggregate mix ratio irrespective of the cement strength class. In this paper, the investigation conducted to determine the appropriate concrete mix ratios required to produce Class 20/25 and Class 25/30 concretes commonly used for design of building structural members using the Portland-limestone cement grades 32.5 and 42.5 that are available in the Nigerian open market is presented. Investigation revealed that the cube compressive strength of 1:2:4 concrete produced with Portland-limestone cement grade 32.5 is less than the minimum 25MPa required for concrete Class 20/25 and a richer 1:1.5:3 concrete produced with Portland-limestone cement grade 32.5 may be needed to produce concrete Class 20/25. Investigation also revealed that Portland-limestone cement grade 32.5 may not be suitable for the production of concrete class 25/30 with cube compressive strength of 30MPa as the cube compressive strength of 1:1:2 concrete produced with Portland-limestone cement grade 32.5 may not attain 30MPa. Concrete strength classes 20/25 and class 25/30 can be produced with Portland-limestone cement grade 42.5 using 1:2:4 and 1:1.5:3 mix ratios respectively. To produce concrete with strength class C20/25 which is the minimum concrete strength class recommended for the construction of the load-bearing building structural members using the 1:2:4 mix ratio, Portland-limestone cement grade 42.5 is required.

  17. Hydrophobic aggregation of ultrafine kaolinite

    Institute of Scientific and Technical Information of China (English)

    ZHANG Xiao-ping; HU Yue-hua; LIU Run-Qing

    2008-01-01

    The hydrophobic aggregation of ultrafine kaolinite in cationic surfactant suspension was investigated by sedimentation test, zeta potential measurement and SEM observation. SEM images reveal that kaolinite particles show the self-aggregation of edge-face in acidic media, the aggregation of edge-face and edge-edge in neutral media, and the dispersion in alkaline media due to electrostatic repulsion. In the presence of the dodecylammonium acetate cationic surfactant and in neutral and alkaline suspension, the hydrophobic aggregation of face-face is demonstrated. The zeta potential of kaolinite increases with increasing the concentration of cationic surfactant. The small and loose aggregation at a low concentration but big and tight aggregation at a high concentration is presented At pH=7 alkyl quarterly amine salt CTAB has the best hydrophobic aggregation among three cationic surfactants, namely, dodecylammonium acetate, alkyl quarterly amine salts 1227 and CTAB.

  18. Absorption Spectra of Astaxanthin Aggregates

    CERN Document Server

    Olsina, Jan; Minofar, Babak; Polivka, Tomas; Mancal, Tomas

    2012-01-01

    Carotenoids in hydrated polar solvents form aggregates characterized by dramatic changes in their absorption spectra with respect to monomers. Here we analyze absorption spectra of aggregates of the carotenoid astaxanthin in hydrated dimethylsulfoxide. Depending on water content, two types of aggregates were produced: H-aggregates with absorption maximum around 390 nm, and J-aggregates with red-shifted absorption band peaking at wavelengths >550 nm. The large shifts with respect to absorption maximum of monomeric astaxanthin (470-495 nm depending on solvent) are caused by excitonic interaction between aggregated molecules. We applied molecular dynamics simulations to elucidate structure of astaxanthin dimer in water, and the resulting structure was used as a basis for calculations of absorption spectra. Absorption spectra of astaxanthin aggregates in hydrated dimethylsulfoxide were calculated using molecular exciton model with the resonance interaction energy between astaxanthin monomers constrained by semi-e...

  19. Non-Arrhenius protein aggregation.

    Science.gov (United States)

    Wang, Wei; Roberts, Christopher J

    2013-07-01

    Protein aggregation presents one of the key challenges in the development of protein biotherapeutics. It affects not only product quality but also potentially impacts safety, as protein aggregates have been shown to be linked with cytotoxicity and patient immunogenicity. Therefore, investigations of protein aggregation remain a major focus in pharmaceutical companies and academic institutions. Due to the complexity of the aggregation process and temperature-dependent conformational stability, temperature-induced protein aggregation is often non-Arrhenius over even relatively small temperature windows relevant for product development, and this makes low-temperature extrapolation difficult based simply on accelerated stability studies at high temperatures. This review discusses the non-Arrhenius nature of the temperature dependence of protein aggregation, explores possible causes, and considers inherent hurdles for accurately extrapolating aggregation rates from conventional industrial approaches for selecting accelerated conditions and from conventional or more advanced methods of analyzing the resulting rate data.

  20. Probabilistic prediction models for aggregate quarry siting

    Science.gov (United States)

    Robinson, G.R.; Larkins, P.M.

    2007-01-01

    Weights-of-evidence (WofE) and logistic regression techniques were used in a GIS framework to predict the spatial likelihood (prospectivity) of crushed-stone aggregate quarry development. The joint conditional probability models, based on geology, transportation network, and population density variables, were defined using quarry location and time of development data for the New England States, North Carolina, and South Carolina, USA. The Quarry Operation models describe the distribution of active aggregate quarries, independent of the date of opening. The New Quarry models describe the distribution of aggregate quarries when they open. Because of the small number of new quarries developed in the study areas during the last decade, independent New Quarry models have low parameter estimate reliability. The performance of parameter estimates derived for Quarry Operation models, defined by a larger number of active quarries in the study areas, were tested and evaluated to predict the spatial likelihood of new quarry development. Population density conditions at the time of new quarry development were used to modify the population density variable in the Quarry Operation models to apply to new quarry development sites. The Quarry Operation parameters derived for the New England study area, Carolina study area, and the combined New England and Carolina study areas were all similar in magnitude and relative strength. The Quarry Operation model parameters, using the modified population density variables, were found to be a good predictor of new quarry locations. Both the aggregate industry and the land management community can use the model approach to target areas for more detailed site evaluation for quarry location. The models can be revised easily to reflect actual or anticipated changes in transportation and population features. ?? International Association for Mathematical Geology 2007.

  1. Research on Judgment Aggregation Based on Logic

    Directory of Open Access Journals (Sweden)

    Li Dai

    2014-05-01

    Full Text Available Preference aggregation and judgment aggregation are two basic research models of group decision making. And preference aggregation has been deeply studied in social choice theory. However, researches of social choice theory gradually focus on judgment aggregation which appears recently. Judgment aggregation focuses on how to aggregate many consistent logical formulas into one, from the perspective of logic. We try to start with judgment aggregation model based on logic and then explore different solutions to problem of judgment aggregation.

  2. Health-related quality of life in patients with high-risk low-grade glioma (EORTC 22033-26033) : a randomised, open-label, phase 3 intergroup study

    NARCIS (Netherlands)

    Reijneveld, Jaap C; Taphoorn, Martin J B; Coens, Corneel; Bromberg, Jacoline E C; Mason, Warren P; Hoang-Xuan, Khê; Ryan, Gail; Hassel, Mohamed Ben; Enting, Roelien H; Brandes, Alba A; Wick, Antje; Chinot, Olivier; Reni, Michele; Kantor, Guy; Thiessen, Brian; Klein, Martin; Verger, Eugenie; Borchers, Christian; Hau, Peter; Back, Michael; Smits, Anja; Golfinopoulos, Vassilis; Gorlia, Thierry; Bottomley, Andrew; Stupp, Roger; Baumert, Brigitta G

    2016-01-01

    BACKGROUND: Temozolomide chemotherapy versus radiotherapy in patients with a high-risk low-grade glioma has been shown to have no significant effect on progression-free survival. If these treatments have a different effect on health-related quality of life (HRQOL), it might affect the choice of ther

  3. Role of Standard Demand Response Signals for Advanced Automated Aggregation

    Energy Technology Data Exchange (ETDEWEB)

    Lawrence Berkeley National Laboratory; Kiliccote, Sila

    2011-11-18

    Emerging standards such as OpenADR enable Demand Response (DR) Resources to interact directly with Utilities and Independent System Operators to allow their facility automation equipment to respond to a variety of DR signals ranging from day ahead to real time ancillary services. In addition, there are Aggregators in today’s markets who are capable of bringing together collections of aggregated DR assets and selling them to the grid as a single resource. However, in most cases these aggregated resources are not automated and when they are, they typically use proprietary technologies. There is a need for a framework for dealing with aggregated resources that supports the following requirements: • Allows demand-side resources to participate in multiple DR markets ranging from wholesale ancillary services to retail tariffs without being completely committed to a single entity like an Aggregator; • Allow aggregated groups of demand-side resources to be formed in an ad hoc fashion to address specific grid-side issues and support the optimization of the collective response of an aggregated group along a number of different dimensions. This is important in order to taylor the aggregated performance envelope to the needs to of the grid; • Allow aggregated groups to be formed in a hierarchical fashion so that each group can participate in variety of markets from wholesale ancillary services to distribution level retail tariffs. This paper explores the issues of aggregated groups of DR resources as described above especially within the context of emerging smart grid standards and the role they will play in both the management and interaction of various grid-side entities with those resources.

  4. Crack Initiation Assessment of Wearing Course Asphalt Mixtures Using Aggregate Gradation Characteristic

    Directory of Open Access Journals (Sweden)

    Dr. Iman Haryanto

    2007-05-01

    Full Text Available At normal service temperatures, wearing course asphalt mixtures may have ductile cracking. Aggregate gradation characteristic is important to avoid the premature cracking. The present study discusses a relationship between the characteristic of aggregate gradation and crack resistance of wearing course mixtures. Asphalt mixture specimens were prepared using different types of aggregate gradation. The Bailey method was employed in order to recognize the characteristic of aggregate gradations. Notched semi circular bending test was conducted to obtain the critical J integral (Jc. The coarse aggregate (CA ratio and the fine graded fine aggregate coarse (FG FAc ratio defined by the Bailey method were introduced to recognize the effect of aggregate gradation type on Jc. The result was decreasing the Jc value with increasing the CA ratio and FG FAc ratio. Satisfying the current Bailey criterion on the CA ratio for stone mastic asphalt mixtures and setting FG FAc of fine graded HMA mixtures near 0.4 seem useful in order to obtain HMA mixtures with a high Jc. The present study also discusses spherical aggregates assembly models as an aid to illustrate development of the aggregates interlocking, which influences to the cracking.

  5. Novel aspects of platelet aggregation

    Directory of Open Access Journals (Sweden)

    Roka-Moya Y. M.

    2014-01-01

    Full Text Available The platelet aggregation is an important process, which is critical for the hemostatic plug formation and thrombosis. Recent studies have shown that the platelet aggregation is more complex and dynamic than it was previously thought. There are several mechanisms that can initiate the platelet aggregation and each of them operates under specific conditions in vivo. At the same time, the influence of certain plasma proteins on this process should be considered. This review intends to summarize the recent data concerning the adhesive molecules and their receptors, which provide the platelet aggregation under different conditions.

  6. Fractal Aggregation Under Rotation

    Institute of Scientific and Technical Information of China (English)

    WU Feng-Min; WU Li-Li; LU Hang-Jun; LI Qiao-Wen; YE Gao-Xiang

    2004-01-01

    By means of the Monte Carlo simulation, a fractal growth model is introduced to describe diffusion-limited aggregation (DLA) under rotation. Patterns which are different from the classical DLA model are observed and the fractal dimension of such clusters is calculated. It is found that the pattern of the clusters and their fractal dimension depend strongly on the rotation velocity of the diffusing particle. Our results indicate the transition from fractal to non-fractal behavior of growing cluster with increasing rotation velocity, i.e. for small enough angular velocity ω the fractal dimension decreases with increasing ω, but then, with increasing rotation velocity, the fractal dimension increases and the cluster becomes compact and tends to non-fractal.

  7. Fractal Aggregation Under Rotation

    Institute of Scientific and Technical Information of China (English)

    WUFeng-Min; WULi-Li; LUHang-Jun; LIQiao-Wen; YEGao-Xiang

    2004-01-01

    By means of the Monte Carlo simulation, a fractal growth model is introduced to describe diffusion-limited aggregation (DLA) under rotation. Patterns which are different from the classical DLA model are observed and the fractal dimension of such clusters is calculated. It is found that the pattern of the clusters and their fractal dimension depend strongly on the rotation velocity of the diffusing particle. Our results indicate the transition from fractal to non-fractal behavior of growing cluster with increasing rotation velocity, i.e. for small enough angular velocity ω; thefractal dimension decreases with increasing ω;, but then, with increasing rotation velocity, the fractal dimension increases and the cluster becomes compact and tends to non-fractal.

  8. Platelet aggregation following trauma

    DEFF Research Database (Denmark)

    Windeløv, Nis A; Sørensen, Anne M; Perner, Anders

    2014-01-01

    We aimed to elucidate platelet function in trauma patients, as it is pivotal for hemostasis yet remains scarcely investigated in this population. We conducted a prospective observational study of platelet aggregation capacity in 213 adult trauma patients on admission to an emergency department (ED......). Inclusion criteria were trauma team activation and arterial cannula insertion on arrival. Blood samples were analyzed by multiple electrode aggregometry initiated by thrombin receptor agonist peptide 6 (TRAP) or collagen using a Multiplate device. Blood was sampled median 65 min after injury; median injury...... severity score (ISS) was 17; 14 (7%) patients received 10 or more units of red blood cells in the ED (massive transfusion); 24 (11%) patients died within 28 days of trauma: 17 due to cerebral injuries, four due to exsanguination, and three from other causes. No significant association was found between...

  9. Hydrophobically modified polyelectrolytes: Characterization, aggregation and adsorption

    Science.gov (United States)

    Islam, Mohammad Ferdous

    The focus of our work was to experimentally study the aggregation and adsorption behavior of model HM polyelectrolytes. Hydrophobically modified alkali soluble emulsions (HASE), the model HM polyelectrolytes, were chosen because they had complex architecture yet possessed key variables for systematic study. The HASE polymers have methacrylic acid (MAA) and ethyl acrylate (EA) in the backbone with pendent hydrophobic groups. Characterization of a single molecule is an important first step in understanding the aggregation and adsorption of these polymers. However, characterizations of the HASE polymers using conventional techniques such as gel permeation chromatography or static light scattering were difficult because of the hydrophobic association. In this study, two different approaches have been taken to prevent the hydrophobic association in aqueous solution: (1) hydrolyze the polymer to cleave the hydrophobic constituents, and (2) use methyl beta-cyclodextrin that has a hydrophobic cavity and a hydrophilic outer shell, to shield the hydrophobes from associating. By taking these two approaches and using gel permeation chromatography (GPC), dynamic (DLS) and static (SLS) light scattering techniques, the molecular weight, hydrodynamic radius and radius of gyration of a single molecule were determined. Except for one chemical site, we were able to determine that branching or grafting did not occur in the polymer chain during synthesis. Our aggregation studies showed that, in aqueous solutions, the HASE polymers formed small aggregates (presumably single micelles of single or a few chains) and large aggregates (presumably formed by bridging between micelles). The radii and masses of the larger aggregates, measured using DLS and SLS, were found to increase with an increase in the polymer concentration, indicating an open association process for the HASE polymers. Our SLS results also showed that, at high salt concentration, the aggregates of the HASE polymer with

  10. Explaining the length threshold of polyglutamine aggregation

    Science.gov (United States)

    De Los Rios, Paolo; Hafner, Marc; Pastore, Annalisa

    2012-06-01

    The existence of a length threshold, of about 35 residues, above which polyglutamine repeats can give rise to aggregation and to pathologies, is one of the hallmarks of polyglutamine neurodegenerative diseases such as Huntington’s disease. The reason why such a minimal length exists at all has remained one of the main open issues in research on the molecular origins of such classes of diseases. Following the seminal proposals of Perutz, most research has focused on the hunt for a special structure, attainable only above the minimal length, able to trigger aggregation. Such a structure has remained elusive and there is growing evidence that it might not exist at all. Here we review some basic polymer and statistical physics facts and show that the existence of a threshold is compatible with the modulation that the repeat length imposes on the association and dissociation rates of polyglutamine polypeptides to and from oligomers. In particular, their dramatically different functional dependence on the length rationalizes the very presence of a threshold and hints at the cellular processes that might be at play, in vivo, to prevent aggregation and the consequent onset of the disease.

  11. A multi-center open-labeled study of recombinant erythropoietin-beta in the treatment of anemic patients with multiple myeloma, low-grade non-Hodgkin's lymphoma, or chronic lymphocytic leukemia in Chinese population.

    Science.gov (United States)

    Yang, Shen; Jun, Ma; Hong-Li, Zhu; Jian-Min, Wang; Chun, Wang; Lu-Gui, Qiu; Yong-Qiang, Zhao; Jun, Zhu; Jian, Hou; Zhi-Xiang, Shen

    2008-09-01

    The purpose of this study is to investigate the efficacy and safety of recombinant erythropoietin-beta in the treatment of anemic patients with multiple myeloma (MM), low-grade non-Hodgkin's lymphoma (NHL), and chronic lymphocytic leukemia (CLL). From December 2005 to November 2006, the patients with MM, low-grade NHL, and CLL were enrolled in this study, male or female, aged > or = 18 years, transfusion-dependant, and receiving anti-neoplasia chemotherapy. Recombinant human erythropoietin-beta was used in this study with the dose initiated at 150 IU/kg, thrice a week, subcutaneously. The total treatment duration was 12 weeks. The primary endpoint of the study is response rate (RR), which is defined as hemoglobin increasing > or = 2 g/dL comparing to baseline level, or returning to normal range, without any transfusion within 6 weeks of evaluation. Fifty out of 82 (64.6%) patients enrolled in this study responded to the treatment and 29 patients had no response. Hypertension (12.2%) is the most common adverse effect; however, all the adverse events were mild, categorized in NCI grade I or II. We conclude that recombinant erythropoietin-beta was effective in the treatment of anemia of the patients with MM, NHL, and CLL, as well as it is well-tolerated.

  12. Exciton dynamics in molecular aggregates

    NARCIS (Netherlands)

    Augulis, R.; Pugžlys, A.; Loosdrecht, P.H.M. van; Pugzlys, A

    2006-01-01

    The fundamental aspects of exciton dynamics in double-wall cylindrical aggregates of cyanine dyes are studied by means of frequency resolved femtosecond pump-probe spectroscopy. The collective excitations of the aggregates, resulting from intermolecular dipole-dipole interactions have the characteri

  13. Aggregate resources in the Netherlands

    NARCIS (Netherlands)

    Meulen, M.J. van der; Gessel, S.F. van; Veldkamp, J.G.

    2005-01-01

    We have built a 3D lithological model of the Netherlands, for the purpose of mapping on-land aggregate resources down to 50 m below the surface. The model consists of voxel cells (1000 · 1000 · 1 m), with lithological composition and aggregate content estimates as primary attributes. These attribute

  14. Exciton dynamics in molecular aggregates

    NARCIS (Netherlands)

    Augulis, R.; Pugžlys, A.; Loosdrecht, P.H.M. van; Pugzlys, A

    2006-01-01

    The fundamental aspects of exciton dynamics in double-wall cylindrical aggregates of cyanine dyes are studied by means of frequency resolved femtosecond pump-probe spectroscopy. The collective excitations of the aggregates, resulting from intermolecular dipole-dipole interactions have the

  15. The Role of Content Aggregators In GEOValue

    Science.gov (United States)

    Wright, D. J.; Breyer, S.; Hogeweg, M.; Foust, J.; Jordan, L.; Plunkett, G.

    2016-12-01

    Data (aka content) in the form of numbers or layers, and transformed into information by way of maps, images, graphs, charts, tables, even stories, are foundational for a myriad of decision-makers. Recent advances in information technology, as well as civil remote sensing of the Earth, are rapidly allowing us to advance beyond mere static data collection and archiving, further enabling information awareness and understanding, and leading us towards knowledge and better decision making. However, such volumes, velocities, and varieties of data streams also bring with them serious dilemmas with regard to effective organization, cataloging, and easy access. This is where the role of aggregator comes in, with their provision of the necessary sustainability and reliability of information via proven, well-engineered platforms, all with the necessary interoperability and openness as guaranteed through the adoption of established standards. Information technology (IT) giants such as Google, Facebook, IBM and Apple are well known for aggregating just about every aspect of life in modern society, from our music to our mood swings. A use case of the Environmental Systems Research Institute (aka Esri) is presented as a geospatial aggregator. It has over the years, compiled, assembled and produced a carefully curated library of public content into a global "Living Atlas of the World," organized into different themes such as Earth observation, transportation, demographics, natural hazards, ecological land units, elevation, and more. Among a myriad of decision scenarios with this content to be presented is the tracking of sea ice in the Arctic, estimating potential impact to shipping lanes or coastal infrastructure, and forecasting future conditions. Esri as the main aggregator of Living Atlas content continues to welcome not only contributors who will publish new content to be included in this global Atlas, but fellow curators who will assist in reviewing, organizing, and even

  16. Molecular aggregation of humic substances

    Science.gov (United States)

    Wershaw, R. L.

    1999-01-01

    Humic substances (HS) form molecular aggregates in solution and on mineral surfaces. Elucidation of the mechanism of formation of these aggregates is important for an understanding of the interactions of HS in soils arid natural waters. The HS are formed mainly by enzymatic depolymerization and oxidation of plant biopolymers. These reactions transform the aromatic and lipid plant components into amphiphilic molecules, that is, molecules that consist of separate hydrophobic (nonpolar) and hydrophilic (polar) parts. The nonpolar parts of the molecules are composed of relatively unaltered segments of plant polymers and the polar parts of carboxylic acid groups. These amphiphiles form membrane-like aggregates on mineral surfaces and micelle-like aggregates in solution. The exterior surfaces of these aggregates are hydrophilic, and the interiors constitute separate hydrophobic liquid-like phases.

  17. Optical monitoring of particle aggregates

    Institute of Scientific and Technical Information of China (English)

    John Gregory

    2009-01-01

    Methods for monitoring particle aggregation are briefly reviewed. Most of these techniques are based on some form of light scattering and may be greatly dependent on the optical properties of aggregates, which are not generally known. As fractal aggregates grow larger their density can become very low and this has important practical consequences for light scattering. For instance, the scattering coefficient may be much less than for solid objects, which means that the aggregates can appear much smaller than their actual size by a light transmission method. Also, for low-density objects, a high proportion of the scattered light energy is within a small angle of the incident beam, which may also be relevant for measurements with aggregates.Using the 'turbidity fluctuation' technique as an example, it is shown how the apparent size of hydroxide flocs depends mainly on the included impurity particles, rather than the hydroxide precipitate itself. Results using clay suspensions with hydrolyzing coagulants and under are discussed.

  18. Dye Aggregation in Ink Jet

    Institute of Scientific and Technical Information of China (English)

    Thomas Paul; Sarfraz Hussain

    2004-01-01

    Dye aggregation has long been recognised as a key factor in performance, and this is no less so in ink jet applications. The aggregation state was shown to be important in many different areas ranging from the use of dyes in photodynamic therapies all the way to colorants for dying of fabrics. Therefore different methods to investigate dye association qualitatively and quantitatively were developed. A simple procedure to study aggregation could be a useful tool to characterise dyes for ink jet printing. It is critically reviewed the methods used to study dye aggregation, and discussed some of the main conclusions. This will be illustrated by examples of ink jet dye aggregation and its study in aqueous and ink systems. The results are used to correlate the solution behaviour of dyes with their print performance.

  19. DRAG ON SUBMICRON NANOPARTICLE AGGREGATES

    Institute of Scientific and Technical Information of China (English)

    F.; Einar; Kruis

    2005-01-01

    A new procedure was developed for estimating the effective collision diameter of an aggregate composed of primary particles of any size. The coagulation coefficient of two oppositely charged particles was measured experimentally and compared with classic Fuchs theory, including a new method to account for particle non-sphericity. A second set of experiments were performed on well-defined nanoparticle aggregates at different stages of sintering, i.e. from the aggregate to the fully sintered stage. Here, electrical mobility was used to characterize the particle drag. The aggregates are being built from two different size-fractionated nanoparticle aerosols, the non-aggregated particles are discarded by an electrofilter and then they are passed through a furnace at concentrations low enough not to induce coagulation.

  20. Global OpenSearch

    Science.gov (United States)

    Newman, D. J.; Mitchell, A. E.

    2015-12-01

    At AGU 2014, NASA EOSDIS demonstrated a case-study of an OpenSearch framework for Earth science data discovery. That framework leverages the IDN and CWIC OpenSearch API implementations to provide seamless discovery of data through the 'two-step' discovery process as outlined by the Federation for Earth Sciences (ESIP) OpenSearch Best Practices. But how would an Earth Scientist leverage this framework and what are the benefits? Using a client that understands the OpenSearch specification and, for further clarity, the various best practices and extensions, a scientist can discovery a plethora of data not normally accessible either by traditional methods (NASA Earth Data Search, Reverb, etc) or direct methods (going to the source of the data) We will demonstrate, via the CWICSmart web client, how an earth scientist can access regional data on a regional phenomena in a uniform and aggregated manner. We will demonstrate how an earth scientist can 'globalize' their discovery. You want to find local data on 'sea surface temperature of the Indian Ocean'? We can help you with that. 'European meteorological data'? Yes. 'Brazilian rainforest satellite imagery'? That too. CWIC allows you to get earth science data in a uniform fashion from a large number of disparate, world-wide agencies. This is what we mean by Global OpenSearch.

  1. Orthogonal flexible Rydberg aggregates

    Science.gov (United States)

    Leonhardt, K.; Wüster, S.; Rost, J. M.

    2016-02-01

    We study the link between atomic motion and exciton transport in flexible Rydberg aggregates, assemblies of highly excited light alkali-metal atoms, for which motion due to dipole-dipole interaction becomes relevant. In two one-dimensional atom chains crossing at a right angle adiabatic exciton transport is affected by a conical intersection of excitonic energy surfaces, which induces controllable nonadiabatic effects. A joint exciton-motion pulse that is initially governed by a single energy surface is coherently split into two modes after crossing the intersection. The modes induce strongly different atomic motion, leading to clear signatures of nonadiabatic effects in atomic density profiles. We have shown how this scenario can be exploited as an exciton switch, controlling direction and coherence properties of the joint pulse on the second of the chains [K. Leonhardt et al., Phys. Rev. Lett. 113, 223001 (2014), 10.1103/PhysRevLett.113.223001]. In this article we discuss the underlying complex dynamics in detail, characterize the switch, and derive our isotropic interaction model from a realistic anisotropic one with the addition of a magnetic bias field.

  2. Orthogonal flexible Rydberg aggregates

    CERN Document Server

    Leonhardt, K; Rost, J M

    2015-01-01

    We study the link between atomic motion and exciton transport in flexible Rydberg aggregates, assemblies of highly excited light alkali atoms, for which motion due to dipole-dipole interaction becomes relevant. In two one-dimensional atom chains crossing at a right angle adiabatic exciton transport is affected by a conical intersection of excitonic energy surfaces, which induces controllable non-adiabatic effects. A joint exciton/motion pulse that is initially governed by a single energy surface is coherently split into two modes after crossing the intersection. The modes induce strongly different atomic motion, leading to clear signatures of non-adiabatic effects in atomic density profiles. We have shown how this scenario can be exploited as an exciton switch, controlling direction and coherence properties of the joint pulse on the second of the chains [K.~Leonhardt {\\it et al.}, Phys.~Rev.~Lett. {\\bf 113} 223001 (2014)]. In this article we discuss the underlying complex dynamics in detail, characterise the ...

  3. Open access

    NARCIS (Netherlands)

    Valkenburg, P.M.

    2015-01-01

    Open access week Van 19 tot en met 25 oktober 2015 vond wereldwijd de Open Access Week plaats. Tijdens deze week werden er over de hele wereld evenementen georganiseerd waar open access een rol speelt. Ook in Nederland zijn er diverse symposia, workshops en debatten georganiseerd zoals het debat in

  4. Tratamiento de pacientes con fracturas por proyectil de arma de fuego de baja velocidad, Hospital Universitario San Vicente de Paúl, Medellín, 2002-2003 Management of the patients with grade I open fractures by low-velocity gunshots in San Vicente de Paúl University Hospital, 2002-2003

    Directory of Open Access Journals (Sweden)

    Alejandro Uribe Ríos

    2007-03-01

    Full Text Available El propósito del presente trabajo fue evaluar el resultado del manejo de fracturas grado I producidas por proyectil de arma de fuego de baja velocidad, sin lavado y desbridamiento quirúrgico en el momento del ingreso al hospital. Se realizó un estudio retrospectivo evaluando las historias clínicas de los pacientes que ingresaban con este diagnóstico al servicio de urgencias adultos del HUSVP entre enero de 2002 y junio de 2003. Se hizo seguimiento de 77 fracturas en 74 pacientes, hasta lograr la consolidación clínica y radiológica de las fracturas. Todos los pacientes recibieron tratamiento antibiótico según los protocolos del servicio de ortopedia. Se encontró mayor frecuencia de fracturas de huesos largos: tibia (19%, fémur (18% y húmero (17%. Ningún paciente requirió lavado quirúrgico durante el manejo. Del total de fracturas, 53,2% recibieron manejo no quirúrgico, 40,2% reducción abierta y fijación interna y 6,6% fijación externa; ninguno de los pacientes presentó signos de infección durante la evolución. Con este trabajo se puede recomendar el tratamiento sin lavado y desbridamiento quirúrgico para los pacientes con fracturas grado I producidas por proyectil de arma de fuego de baja velocidad The purpose of this study was to evaluate the result of the management of grade I open fractures by low-velocity gunshots, without surgical debridement. A retrospective study evaluating the clinical histories of patients admitted in the emergency room with this diagnose between January 2002 and June 2003. Search was carried out within 77 fractures in 74 patients, until achieving the clinical and radiological consolidation of the fractures. All the patients received antibiotic treatment according to the protocols of the trauma service. The majority of fractures occurred in long bones: Tibia (19%, Femur (18% and Humerus (17%. No patient required surgical debridement in the evolution of the treatment. A total of 53.2% of the

  5. Vascular grading of angiogenesis

    DEFF Research Database (Denmark)

    Hansen, S; Grabau, D A; Sørensen, Flemming Brandt;

    2000-01-01

    was moderately reproduced (kappa = 0.59). Vascular grade was significantly associated with axillary node involvement, tumour size, malignancy grade, oestrogen receptor status and histological type. In univariate analyses vascular grade significantly predicted recurrence free survival and overall survival for all...... patients (P analysis showed that vascular grading contributed with independent prognostic value in all patients (P

  6. Asterisk Grade Study Report.

    Science.gov (United States)

    Kokorsky, Eileen A.

    A study was conducted at Passaic County Community College (PCCC) to investigate the operation of a grading system which utilized an asterisk (*) grade to indicate progress in a course until a letter grade was assigned. The study sought to determine the persistence of students receiving the "*" grade, the incidence of cases of students receiving…

  7. Comparison of different forms of gravel as aggregate in concrete

    Directory of Open Access Journals (Sweden)

    Sikiru ORITOLA

    2014-11-01

    Full Text Available Gradation plays an important role in the workability, segregation, and pump ability of concrete. Uniformly distributed aggregates require less paste which will also decrease bleeding, creep and shrinkage while producing better workability, more durable concrete and higher packing. This attempt looks at the effect of particle size distribution pattern for five types of gravel aggregate forms, angular, elongated, smooth rounded, irregular and flaky as related to the strength of concrete produced. Different forms of naturally existing gravel aggregate were collected from a particular location and tests were carried out on them to determine their gradation. Based on the gradation the aggregates were used to prepare different samples of grade 20 concrete with water-cement ratio of 0.5. The particle size distribution resulted in coefficients of uniformity ranging from 1.24 to 1.44. The granite aggregate, which serves as a reference, had a coefficient of uniformity of 1.47. Tests were conducted on fresh and hardened concrete cube samples. The concrete sample CT5 recorded a slump of 32mm and highest compressive strength value of 21.7 N/mm2, among the concrete produced from different forms of gravel.

  8. An Outline of Data Aggregation Security in Heterogeneous Wireless Sensor Networks

    Directory of Open Access Journals (Sweden)

    Sabrina Boubiche

    2016-04-01

    Full Text Available Data aggregation processes aim to reduce the amount of exchanged data in wireless sensor networks and consequently minimize the packet overhead and optimize energy efficiency. Securing the data aggregation process is a real challenge since the aggregation nodes must access the relayed data to apply the aggregation functions. The data aggregation security problem has been widely addressed in classical homogeneous wireless sensor networks, however, most of the proposed security protocols cannot guarantee a high level of security since the sensor node resources are limited. Heterogeneous wireless sensor networks have recently emerged as a new wireless sensor network category which expands the sensor nodes’ resources and capabilities. These new kinds of WSNs have opened new research opportunities where security represents a most attractive area. Indeed, robust and high security level algorithms can be used to secure the data aggregation at the heterogeneous aggregation nodes which is impossible in classical homogeneous WSNs. Contrary to the homogeneous sensor networks, the data aggregation security problem is still not sufficiently covered and the proposed data aggregation security protocols are numberless. To address this recent research area, this paper describes the data aggregation security problem in heterogeneous wireless sensor networks and surveys a few proposed security protocols. A classification and evaluation of the existing protocols is also introduced based on the adopted data aggregation security approach.

  9. An Outline of Data Aggregation Security in Heterogeneous Wireless Sensor Networks.

    Science.gov (United States)

    Boubiche, Sabrina; Boubiche, Djallel Eddine; Bilami, Azzedine; Toral-Cruz, Homero

    2016-04-12

    Data aggregation processes aim to reduce the amount of exchanged data in wireless sensor networks and consequently minimize the packet overhead and optimize energy efficiency. Securing the data aggregation process is a real challenge since the aggregation nodes must access the relayed data to apply the aggregation functions. The data aggregation security problem has been widely addressed in classical homogeneous wireless sensor networks, however, most of the proposed security protocols cannot guarantee a high level of security since the sensor node resources are limited. Heterogeneous wireless sensor networks have recently emerged as a new wireless sensor network category which expands the sensor nodes' resources and capabilities. These new kinds of WSNs have opened new research opportunities where security represents a most attractive area. Indeed, robust and high security level algorithms can be used to secure the data aggregation at the heterogeneous aggregation nodes which is impossible in classical homogeneous WSNs. Contrary to the homogeneous sensor networks, the data aggregation security problem is still not sufficiently covered and the proposed data aggregation security protocols are numberless. To address this recent research area, this paper describes the data aggregation security problem in heterogeneous wireless sensor networks and surveys a few proposed security protocols. A classification and evaluation of the existing protocols is also introduced based on the adopted data aggregation security approach.

  10. Development of an automatic visual grading system for grafting seedlings

    Directory of Open Access Journals (Sweden)

    Subo Tian

    2017-01-01

    Full Text Available In this study, a visual grading system of vegetable grafting machine was developed. The study described key technology of visual grading system of vegetable grafting machine. First, the contrasting experiment was conducted between acquired images under blue background light and natural light conditions, with the blue background light chosen as lighting source. The Visual C++ platform with open-source computer vision library (Open CV was used for the image processing. Subsequently, maximum frequency of total number of 0-valued pixels was predicted and used to extract the measurements of scion and rootstock stem diameters. Finally, the developed integrated visual grading system was experimented with 100 scions and rootstock seedlings. The results showed that success rate of grading reached up to 98%. This shows that selection and grading of scion and rootstock could be fully automated with this developed visual grading system. Hence, this technology would be greatly helpful for improving the grading accuracy and efficiency.

  11. 7 CFR 51.2542 - U.S. Artificially Opened.

    Science.gov (United States)

    2010-01-01

    ... STANDARDS) United States Standards for Grades of Pistachio Nuts in the Shell § 51.2542 U.S. Artificially Opened. “U.S. Artificially Opened” consists of artificially opened pistachio nuts in the shell which...

  12. Influence of aggregate mineralogical composition on water resistance of aggregate–bitumen adhesion

    OpenAIRE

    Zhang, Jizhe; Apeagyei, Alex K.; AIREY, Gordon D; Grenfell, James R.A.

    2015-01-01

    The effects of aggregate mineralogical composition on moistures sensitivity of aggregate–bitumen bonds were investigated using four aggregate types (two limestone and two granite)and two bitumen grades (40/60 penand70/100pen). Moisture sensitivity (or water resistance) of the aggregate–bitumen bonds were characterized using retained strength obtained from three different tensile tests (peel, PATTI and pull-off). The results showed significant differences in the amount of moisture absorbed ...

  13. Grade Inflation Rates among Different Ability Students

    Directory of Open Access Journals (Sweden)

    Stephanie Mc Spirit

    1999-09-01

    Full Text Available This study compares grade inflation rates among different ability students at a large, open admissions public University. Specifically, this study compares trends in graduating grade point average (GPA from 1983 to 1996 across low, typical and higher ability students. This study also tests other explanations for increases in graduating GPA. These other explanations are changes in 1 ACT score 2 gender 3 college major and 4 vocational programs. With these other explanations considered, regression results still report an inflationary trend in graduating GPA. Time, as measured by college entry year, is still a significant positive predictor of GPA. More directly, comparisons of regression coefficients reveal lower ability students as experiencing the highest rate of grade increase. Higher grade inflation rates among low aptitude students suggest that faculty might be using grades to encourage learning among marginal students.

  14. Grade Inflation Rates among Different Ability Students, Controlling for Other Factors.

    Science.gov (United States)

    Mc Spirit, Stephanie; Jones, Kirk E.

    1999-01-01

    Compared grade inflation rates among students of different abilities at an open-admissions public university by examining trends in graduating grade point average from 1983 to 1996. The higher grade inflation rates among low aptitude students suggest that faculty might be using grades to encourage learning among marginal students. (SLD)

  15. Aggregating and Disaggregating Flexibility Objects

    DEFF Research Database (Denmark)

    Siksnys, Laurynas; Valsomatzis, Emmanouil; Hose, Katja

    2015-01-01

    In many scientific and commercial domains we encounter flexibility objects, i.e., objects with explicit flexibilities in a time and an amount dimension (e.g., energy or product amount). Applications of flexibility objects require novel and efficient techniques capable of handling large amounts...... energy data management and discuss strategies for aggregation and disaggregation of flex-objects while retaining flexibility. This paper further extends these approaches beyond flex-objects originating from energy consumption by additionally considering flex-objects originating from energy production...... and aiming at energy balancing during aggregation. In more detail, this paper considers the complete life cycle of flex-objects: aggregation, disaggregation, associated requirements, efficient incremental computation, and balance aggregation techniques. Extensive experiments based on real-world data from...

  16. Dependability in Aggregation by Averaging

    CERN Document Server

    Jesus, Paulo; Almeida, Paulo Sérgio

    2010-01-01

    Aggregation is an important building block of modern distributed applications, allowing the determination of meaningful properties (e.g. network size, total storage capacity, average load, majorities, etc.) that are used to direct the execution of the system. However, the majority of the existing aggregation algorithms exhibit relevant dependability issues, when prospecting their use in real application environments. In this paper, we reveal some dependability issues of aggregation algorithms based on iterative averaging techniques, giving some directions to solve them. This class of algorithms is considered robust (when compared to common tree-based approaches), being independent from the used routing topology and providing an aggregation result at all nodes. However, their robustness is strongly challenged and their correctness often compromised, when changing the assumptions of their working environment to more realistic ones. The correctness of this class of algorithms relies on the maintenance of a funda...

  17. DESIGNING AN INTEGRATED OPEN INNOVATION SYSTEM: TOWARDS ORGANIZATIONAL WHOLENESS

    DEFF Research Database (Denmark)

    Baka, Vasiliki

    2014-01-01

    that are concurrently acting as corporate websites, internal collaboration spaces, extranets and social media aggregators, actively promotes open innovation in practice. We close with a presentation of six cases that are illustrative of how such a system could be applicable within the open innovation paradigm, namely......, citizen participation, crowdsourcing and open innovation contests, open source innovation, reviews and social media, social enterprises and open teaching....

  18. Model for amorphous aggregation processes

    Science.gov (United States)

    Stranks, Samuel D.; Ecroyd, Heath; van Sluyter, Steven; Waters, Elizabeth J.; Carver, John A.; von Smekal, Lorenz

    2009-11-01

    The amorphous aggregation of proteins is associated with many phenomena, ranging from the formation of protein wine haze to the development of cataract in the eye lens and the precipitation of recombinant proteins during their expression and purification. While much literature exists describing models for linear protein aggregation, such as amyloid fibril formation, there are few reports of models which address amorphous aggregation. Here, we propose a model to describe the amorphous aggregation of proteins which is also more widely applicable to other situations where a similar process occurs, such as in the formation of colloids and nanoclusters. As first applications of the model, we have tested it against experimental turbidimetry data of three proteins relevant to the wine industry and biochemistry, namely, thaumatin, a thaumatinlike protein, and α -lactalbumin. The model is very robust and describes amorphous experimental data to a high degree of accuracy. Details about the aggregation process, such as shape parameters of the aggregates and rate constants, can also be extracted.

  19. Laboratory Investigation of Fatigue Characteristics of Asphalt Mixtures with Steel Slag Aggregates

    Directory of Open Access Journals (Sweden)

    Hassan Ziari

    2015-01-01

    Full Text Available There are many steel-manufacturing factories in Iran. All of their byproducts, steel slag, are dumped randomly in open areas, causing many environmentally hazardous problems. This research is intended to study the effectiveness of using steel slag aggregate (SSA in improving the engineering properties, especially fatigue life of Asphalt Concrete (AC produced with steel slag. The research started by evaluating the physical properties of the steel slag aggregate. Then the 13 types of mixes which contain steel slag in portion of fine aggregates or in portion of coarse aggregates or in all portions of aggregates were tested. The effectiveness of the SSA was judged by the improvement in Marshall stability, indirect tensile strength, resilient modulus, and fatigue life of the AC samples. It was found that replacing the 50% of the limestone coarse or fine aggregate by SSA improved the mechanical properties of the AC mixes.

  20. Security analysis of the unrestricted identity-based aggregate signature scheme.

    Directory of Open Access Journals (Sweden)

    Kwangsu Lee

    Full Text Available Aggregate signatures allow anyone to combine different signatures signed by different signers on different messages into a short signature. An ideal aggregate signature scheme is an identity-based aggregate signature (IBAS scheme that supports full aggregation since it can reduce the total transmitted data by using an identity string as a public key and anyone can freely aggregate different signatures. Constructing a secure IBAS scheme that supports full aggregation in bilinear maps is an important open problem. Recently, Yuan et al. proposed such a scheme and claimed its security in the random oracle model under the computational Diffie-Hellman assumption. In this paper, we show that there is an efficient forgery on their IBAS scheme and that their security proof has a serious flaw.

  1. In vivo amyloid aggregation kinetics tracked by time-lapse confocal microscopy in real-time.

    Science.gov (United States)

    Villar-Piqué, Anna; Espargaró, Alba; Ventura, Salvador; Sabate, Raimon

    2016-01-01

    Amyloid polymerization underlies an increasing number of human diseases. Despite this process having been studied extensively in vitro, aggregation is a difficult process to track in vivo due to methodological limitations and the slow kinetics of aggregation reactions in cells and tissues. Herein we exploit the amyloid properties of the inclusions bodies (IBs) formed by amyloidogenic proteins in bacteria to address the kinetics of in vivo amyloid aggregation. To this aim we used time-lapse confocal microscopy and a fusion of the amyloid-beta peptide (A β42) with a fluorescent reporter. This strategy allowed us to follow the intracellular kinetics of amyloid-like aggregation in real-time and to discriminate between variants exhibiting different in vivo aggregation propensity. Overall, the approach opens the possibility to assess the impact of point mutations as well as potential anti-aggregation drugs in the process of amyloid formation in living cells.

  2. An online detection system for aggregate sizes and shapes based on digital image processing

    Science.gov (United States)

    Yang, Jianhong; Chen, Sijia

    2016-07-01

    Traditional aggregate size measuring methods are time-consuming, taxing, and do not deliver online measurements. A new online detection system for determining aggregate size and shape based on a digital camera with a charge-coupled device, and subsequent digital image processing, have been developed to overcome these problems. The system captures images of aggregates while falling and flat lying. Using these data, the particle size and shape distribution can be obtained in real time. Here, we calibrate this method using standard globules. Our experiments show that the maximum particle size distribution error was only 3 wt%, while the maximum particle shape distribution error was only 2 wt% for data derived from falling aggregates, having good dispersion. In contrast, the data for flat-lying aggregates had a maximum particle size distribution error of 12 wt%, and a maximum particle shape distribution error of 10 wt%; their accuracy was clearly lower than for falling aggregates. However, they performed well for single-graded aggregates, and did not require a dispersion device. Our system is low-cost and easy to install. It can successfully achieve online detection of aggregate size and shape with good reliability, and it has great potential for aggregate quality assurance.

  3. Development of construction materials using nano-silica and aggregates recycled from construction and demolition waste.

    Science.gov (United States)

    Mukharjee, Bibhuti Bhusan; Barai, Sudhirkumar V

    2015-06-01

    The present work addresses the development of novel construction materials utilising commercial grade nano-silica and recycled aggregates retrieved from construction and demolition waste. For this, experimental work has been carried out to examine the influence of nano-silica and recycled aggregates on compressive strength, modulus of elasticity, water absorption, density and volume of voids of concrete. Fully natural and recycled aggregate concrete mixes are designed by replacing cement with three levels (0.75%, 1.5% and 3%) of nano-silica. The results of the present investigation depict that improvement in early days compressive strength is achieved with the incorporation of nano-silica in addition to the restoration of reduction in compressive strength of recycled aggregate concrete mixes caused owing to the replacement of natural aggregates by recycled aggregates. Moreover, the increase in water absorption and volume of voids with a reduction of bulk density was detected with the incorporation of recycled aggregates in place of natural aggregates. However, enhancement in density and reduction in water absorption and volume of voids of recycled aggregate concrete resulted from the addition of nano-silica. In addition, the results of the study reveal that nano-silica has no significant effect on elastic modulus of concrete.

  4. Time-resolved LII signals from aggregates of soot particles levitated in room temperature air

    CERN Document Server

    Mitrani, James M

    2015-01-01

    We observed and modeled time-resolved laser-induced incandescence (LII) signals from soot aggregates. Time-resolved LII signals were observed from research-grade soot particles, levitated in room temperature air. We were able to measure sizes and structural properties of our soot particles ex situ, and use those measurements as input parameters when modeling the observed LII signals. We showed that at low laser fluences, aggregation significantly influences LII signals by reducing conductive cooling to the ambient air. At moderate laser fluences, laser-induced disintegration of aggregates occurs, so the effects of aggregation on LII signals are negligible. These results can be applied to extend LII for monitoring formation of soot and nanoparticle aggregates.

  5. Ash Aggregates in Proximal Settings

    Science.gov (United States)

    Porritt, L. A.; Russell, K.

    2012-12-01

    Ash aggregates are thought to have formed within and been deposited by the eruption column and plume and dilute density currents and their associated ash clouds. Moist, turbulent ash clouds are considered critical to ash aggregate formation by facilitating both collision and adhesion of particles. Consequently, they are most commonly found in distal deposits. Proximal deposits containing ash aggregates are less commonly observed but do occur. Here we describe two occurrences of vent proximal ash aggregate-rich deposits; the first within a kimberlite pipe where coated ash pellets and accretionary lapilli are found within the intra-vent sequence; and the second in a glaciovolcanic setting where cored pellets (armoured lapilli) occur within Diamond Mine, Canada, are the residual deposits within the conduit and vent of the volcano and are characterised by an abundance of ash aggregates. Coated ash pellets are dominant but are followed in abundance by ash pellets, accretionary lapilli and rare cored pellets. The coated ash pellets typically range from 1 - 5 mm in diameter and have core to rim ratios of approximately 10:1. The formation and preservation of these aggregates elucidates the style and nature of the explosive phase of kimberlite eruption at A418 (and other pipes?). First, these pyroclasts dictate the intensity of the kimberlite eruption; it must be energetic enough to cause intense fragmentation of the kimberlite to produce a substantial volume of very fine ash (sustained plume attended by concomitant production of pyroclastic density currents. The size and internal structure of the armoured lapilli provide constraints on the nature of the initial explosive phase of eruption at Kima'Kho. Their proximity to the vent also indicates rapid aggregation within the eruption plume. Within both sequences rapid aggregation of ash particles occurred in proximity to the vent. However, the conditions were substantially different leading to the production of armoured

  6. Open hardware for open science

    CERN Multimedia

    CERN Bulletin

    2011-01-01

    Inspired by the open source software movement, the Open Hardware Repository was created to enable hardware developers to share the results of their R&D activities. The recently published CERN Open Hardware Licence offers the legal framework to support this knowledge and technology exchange.   Two years ago, a group of electronics designers led by Javier Serrano, a CERN engineer, working in experimental physics laboratories created the Open Hardware Repository (OHR). This project was initiated in order to facilitate the exchange of hardware designs across the community in line with the ideals of “open science”. The main objectives include avoiding duplication of effort by sharing results across different teams that might be working on the same need. “For hardware developers, the advantages of open hardware are numerous. For example, it is a great learning tool for technologies some developers would not otherwise master, and it avoids unnecessary work if someone ha...

  7. Open Access

    Science.gov (United States)

    Suber, Peter

    2012-01-01

    The Internet lets us share perfect copies of our work with a worldwide audience at virtually no cost. We take advantage of this revolutionary opportunity when we make our work "open access": digital, online, free of charge, and free of most copyright and licensing restrictions. Open access is made possible by the Internet and copyright-holder…

  8. Open Access

    Science.gov (United States)

    Suber, Peter

    2012-01-01

    The Internet lets us share perfect copies of our work with a worldwide audience at virtually no cost. We take advantage of this revolutionary opportunity when we make our work "open access": digital, online, free of charge, and free of most copyright and licensing restrictions. Open access is made possible by the Internet and copyright-holder…

  9. The Question of Selecting Aggregation Operator to Develop Integral Students’ Academic Progress Score

    Directory of Open Access Journals (Sweden)

    S. A. Sakulin

    2016-01-01

    Full Text Available The work concerns the problem of selecting an operator of the grade-based rating aggregation in a variety of subjects to develop the integral score of students’ academic achievements based on expert knowledge. The goal is to justify the choice of an aggregation operator and methods of its construction. The possibilities of aggregation of the grade-based rating are mostly defined by selection of the type of an aggregation operator, which aggregates the individual disciplines ratings using the formalized expert preferences.The paper discusses application options of different aggregation operators in this field, in particular, the arithmetic mean, the weighted arithmetic mean, the Yager's OWA operator. An analysis of the possible use of different operators has shown that the most appropriate in this field is to use the fuzzy measure Choquet integral because this type of aggregation operator complies with all the considered features of the application area. A number of formal mathematical and non-formalized properties of the Choquet integral correspond to these properties. The paper also considers the choice of an appropriate identification method of the fuzzy measure to use the Choquet integral in development of the integral score of students’ academic achievements. It justifies the choice of the identification method based on variance minimization of the fuzzy measure. Other identification methods have properties that militate against their application in the area under consideration.

  10. 露天坑回填土石混合体的渗流特性及颗粒元数值分析%PERMEABILITY CHARACTERISTICS OF ROCK AND SOIL AGGREGATE OF BACKFILLING OPEN-PIT AND PARTICLE ELEMENT NUMERICAL ANALYSIS

    Institute of Scientific and Technical Information of China (English)

    高谦; 刘增辉; 李欣; 李俊华

    2009-01-01

    Combining with the backfilling(RSA) engineering in stope III of Sijiaying open-pit to underground iron mining of Hebei Iron and Steel Group Mining Co.,Ltd.,the permeability of rock and soil aggregate(RSA) is studied systematically by laboratory test,in-situ experiment and numerical simulation. The results show that there is an approximation linear relationship between the permeability coefficient of RSA and its non-uniform degree,and the permeability coefficient of RSA is directly proportional to the void ratio. The permeability of RSA can be reduced effectively by controlling the gradation of particle size of waste rock backfilled and reducing the average particle size and non-uniformity reasonably. The influence order to the seepage discharge of RSA is determined by particle element numerical orthogonal tests. The relationship formulas of the effects of four factors(thickness of back-packing,head pressure,porosity,particle diameter) on the seepage are obtained by quadratic stepwise regression analysis,and it can provide a calculation tool for impermeability of RSA.%针对土石混合体的渗透性,结合唐钢司家营铁矿III采场露天转井下的回填土石混合体工程,采用室内试验、现场试验和数值模拟的方法对其进行系统地研究,得出土石混合体的渗透系数与其非均匀度近似存在线性关系,渗透系数与混合土的孔隙比成正比;合理控制回填废石的粒径级配,降低平均粒径与非均匀度,可有效降低回填土石混合体的渗透性.通过颗粒元数值正交试验确定对土石混合体的渗流量影响顺序,并二次逐步回归出回填层厚度,水头压力,孔隙率,平均粒径对渗流量的关系式,为土石混合体防渗抗渗提供计算工具.

  11. Almost Graded Prime Ideals

    Directory of Open Access Journals (Sweden)

    Ameer Jaber

    2008-01-01

    Full Text Available Problem Statement: Graded commutative ring with unity over an abelian group were introduced by many authors such as T. Y. Lam and C. T. C. Wall, and almost prime ideals over commutative rings with unity were introduced by S.M. Batwadeker and P.K. Sharma, and this forced us to try to extend the theory of almost and n-almost prime ideals to the graded case. Approach: We develop the theory of almost and n-almost prime ideals to the graded case. Results: We extended some basic results about almost and n-almost prime ideals to the graded case, and then we gave a relationship between n-almost graded prime ideals and weakly graded prime ideals. Conclusion: The extended results about almost and n-almost graded prime ideals allow us to classify further properties about almost graded prime ideals. 2000 AMS Mathematics Subject Classification: 13 A 02.

  12. CT Grading of Otosclerosis

    National Research Council Canada - National Science Library

    Lee, T.C; Aviv, R.I; Chen, J.M; Nedzelski, J.M; Fox, A.J; Symons, S.P

    2009-01-01

    ...: The CT grading system for otosclerosis was proposed by Symons and Fanning in 2005. The purpose of this study was to determine if this CT grading system has high interobserver and intraobserver agreement...

  13. Gleason grading system

    Science.gov (United States)

    ... medlineplus.gov/ency/patientinstructions/000920.htm Gleason grading system To use the sharing features on this page, ... score of between 5 and 7. Gleason Grading System Sometimes, it can be hard to predict how ...

  14. Hierarchical organization in aggregates of protein molecules

    DEFF Research Database (Denmark)

    Bohr, Henrik; Kyhle, Anders; Sørensen, Alexis Hammer

    1997-01-01

    The aggregation of proteins into small clusters is studied by atomic force and electron microscopy. Scaling laws and fractal behaviour in the growth of the aggregates and in the correlation between aggregates is seen. A phase diagram of the aggregation process where the protonic concentration...

  15. A Functional Reference Architecture for Aggregators

    DEFF Research Database (Denmark)

    Bondy, Daniel Esteban Morales; Heussen, Kai; Gehrke, Oliver;

    2015-01-01

    Aggregators are considered to be a key enabling technology for harvesting power system services from distributed energy resources (DER). As a precondition for more widespread use of aggregators in power systems, methods for comparing and validating aggregator designs must be established. This paper...... proposes a functional reference architecture for aggregators to address this requirement....

  16. Fractal Aggregates in Tennis Ball Systems

    Science.gov (United States)

    Sabin, J.; Bandin, M.; Prieto, G.; Sarmiento, F.

    2009-01-01

    We present a new practical exercise to explain the mechanisms of aggregation of some colloids which are otherwise not easy to understand. We have used tennis balls to simulate, in a visual way, the aggregation of colloids under reaction-limited colloid aggregation (RLCA) and diffusion-limited colloid aggregation (DLCA) regimes. We have used the…

  17. Open architecture CNC system

    Energy Technology Data Exchange (ETDEWEB)

    Tal, J. [Galil Motion Control Inc., Sunnyvale, CA (United States); Lopez, A.; Edwards, J.M. [Los Alamos National Lab., NM (United States)

    1995-04-01

    In this paper, an alternative solution to the traditional CNC machine tool controller has been introduced. Software and hardware modules have been described and their incorporation in a CNC control system has been outlined. This type of CNC machine tool controller demonstrates that technology is accessible and can be readily implemented into an open architecture machine tool controller. Benefit to the user is greater controller flexibility, while being economically achievable. PC based, motion as well as non-motion features will provide flexibility through a Windows environment. Up-grading this type of controller system through software revisions will keep the machine tool in a competitive state with minimal effort. Software and hardware modules are mass produced permitting competitive procurement and incorporation. Open architecture CNC systems provide diagnostics thus enhancing maintainability, and machine tool up-time. A major concern of traditional CNC systems has been operator training time. Training time can be greatly minimized by making use of Windows environment features.

  18. Open Source and Open Standards

    NARCIS (Netherlands)

    Koper, Rob

    2006-01-01

    Publication reference: Koper, R. (2008). Open Source and Open Standards. In J. M. Spector, M. Merrill, J. van Merriënboer & M. P. Driscol (Eds.), Handbook of Research on Educational Communications and Technology (3rd ed., pp. 355-368). New York: Routledge.

  19. Specification aggregate quarry expansion: a case study demonstrating sustainable management of natural aggregate resources

    Science.gov (United States)

    Langer, William H.; Tucker, M.L.

    2003-01-01

    Many countries, provinces, territories, or states in the European Union, Australia, Canada, the United States, and elsewhere have begun implementing sustainability programs, but most of those programs stop short of sustainable management of aggregate resources. Sustainable practices do not always have to be conducted under the title of sustainability. This case study describes how Lafarge, a large multinational construction materials supplier, implemented the principles of sustainability even though there was an absence of existing local government policies or procedures addressing sustainable resource management. Jefferson County, Colorado, USA, is one of three counties in the six-county Denver, Colorado, region that has potentially available sources of crushed stone. Crushed stone comprises 30 percent of the aggregate produced in the area and plays a major role in regional aggregate resource needs. Jefferson County is home to four of the five crushed stone operations in the Denver region. Lafarge operates one of those four quarries. Lafarge recently proposed to expand its reserves by exchanging company-owned land for existing dedicated open space land adjacent to their quarry but owned by Jefferson County. A similar proposal submitted about 10 years earlier had been denied. Contrary to the earlier proposal, which was predicated on public relations, the new proposal was predicated on public trust. Although not explicitly managed under the moniker of sustainability, Lafarge used basic management principles that embody the tenets of sustainability. To achieve the goals of sustainable aggregate management where no governmental policies existed, Lafarge not only assumed their role of being a responsible corporate and environmental member of the community, but also assumed the role of facilitator to encourage and enable other stakeholders to responsibly resolve legitimate concerns regarding the Lafarge quarry proposal. Lafarge successfully presented an enlightened

  20. An exact approach for aggregated formulations

    DEFF Research Database (Denmark)

    Gamst, Mette; Spoorendonk, Simon; Røpke, Stefan

    optimality cannot be guaranteed by branching on aggregated variables. We present a generic exact solution method to remedy the drawbacks of aggregation. It combines the original and aggregated formulations and applies Benders' decomposition. We apply the method to the Split Delivery Vehicle Routing Problem.......Aggregating formulations is a powerful approach for problems to take on tractable forms. Aggregation may lead to loss of information, i.e. the aggregated formulation may be an approximation of the original problem. In branch-and-bound context, aggregation can also complicate branching, e.g. when...

  1. GRADE Equity Guidelines 3

    DEFF Research Database (Denmark)

    Welch, Vivian A; Akl, Elie A; Pottie, Kevin

    2017-01-01

    OBJECTIVE: The aim of this paper is to describe a conceptual framework for how to consider health equity in the GRADE (Grading Recommendations Assessment and Development Evidence) guideline development process. STUDY DESIGN AND SETTING: Consensus-based guidance developed by the GRADE working grou...

  2. [Grading of prostate cancer].

    Science.gov (United States)

    Kristiansen, G; Roth, W; Helpap, B

    2016-07-01

    The current grading of prostate cancer is based on the classification system of the International Society of Urological Pathology (ISUP) following a consensus conference in Chicago in 2014. The foundations are based on the frequently modified grading system of Gleason. This article presents a brief description of the development to the current ISUP grading system.

  3. Erythrocyte aggregation: Basic aspects and clinical importance

    OpenAIRE

    Oğuz K. Başkurt; Meiselman, Herbert J.

    2013-01-01

    Red blood cells (RBC) aggregate to form two- and three-dimensional structures when suspended in aqueous solutions containing large plasma proteins or polymers; this aggregation is reversible and shear dependent (i.e., dispersed at high shear and reformed at low or stasis). The extent of aggregation is the main determinant of low shear blood viscosity, thus predicting an inverse relationship between aggregation and in vivo blood flow. However, the effects of aggregation on hemodynamic mechanis...

  4. Molecular Aggregation in Disodium Cromoglycate

    Science.gov (United States)

    Singh, Gautam; Agra-Kooijman, D.; Collings, P. J.; Kumar, Satyendra

    2012-02-01

    Details of molecular aggregation in the mesophases of the anti-asthmatic drug disodium cromoglycate (DSCG) have been studied using x-ray synchrotron scattering. The results show two reflections, one at wide angles corresponding to π-π stacking (3.32 å) of molecules, and the other at small angles which is perpendicular to the direction of molecular stacking and corresponds to the distance between the molecular aggregates. The latter varies from 35 - 41 å in the nematic (N) phase and 27 -- 32 å in the columnar (M) phase. The temperature evolution of the stack height, positional order correlations in the lateral direction, and orientation order parameter were determined in the N, M, and biphasic regions. The structure of the N and M phases and the nature of the molecular aggregation, together with their dependence on temperature and concentration, will be presented.

  5. Open IS

    DEFF Research Database (Denmark)

    Germonprez, Matt; Crowston, Kevin; Avital, Michel

    2013-01-01

    The collective intelligence and collective action of “open” communities have produced a variety of complex knowledge goods and radical social change. The Information Systems (IS) community has invested significant effort into researching open communities and the ecosystems in which they operate...... therefore seeks to stimulate a thoughtful and dynamic discussion around the proposition that becoming a more open community will enhance the IS discipline’s scholarly inquiry and global impact....

  6. Open IS

    DEFF Research Database (Denmark)

    Germonprez, Matt; Crowston, Kevin; Avital, Michel

    2013-01-01

    The collective intelligence and collective action of “open” communities have produced a variety of complex knowledge goods and radical social change. The Information Systems (IS) community has invested significant effort into researching open communities and the ecosystems in which they operate...... therefore seeks to stimulate a thoughtful and dynamic discussion around the proposition that becoming a more open community will enhance the IS discipline’s scholarly inquiry and global impact....

  7. SHAPE CHARACTERIZATION OF CONCRETE AGGREGATE

    Directory of Open Access Journals (Sweden)

    Jing Hu

    2011-05-01

    Full Text Available As a composite material, the performance of concrete materials can be expected to depend on the properties of the interfaces between its two major components, aggregate and cement paste. The microstructure at the interfacial transition zone (ITZ is assumed to be different from the bulk material. In general, properties of conventional concrete have been found favoured by optimum packing density of the aggregate. Particle size is a common denominator in such studies. Size segregation in the ITZ among the binder particles in the fresh state, observed in simulation studies by concurrent algorithm-based SPACE system, additionally governs density as well as physical bonding capacity inside these shell-like zones around aggregate particles. These characteristics have been demonstrated qualitatively pertaining also after maturation of the concrete. Such properties of the ITZs have direct impact on composite properties. Despite experimental approaches revealed effects of aggregate grain shape on different features of material structure (among which density, and as a consequence on mechanical properties, it is still an underrated factor in laboratory studies, probably due to the general feeling that a suitable methodology for shape characterization is not available. A scientific argument hindering progress is the interconnected nature of size and shape. Presently, a practical problem preventing shape effects to be emphasized is the limitation of most computer simulation systems in concrete technology to spherical particles. New developments at Delft University of Technology will make it possible in the near future to generate jammed states, or other high-density fresh particle mixtures of non-spherical particles, which thereupon can be subjected to hydration algorithms. This paper will sketch the outlines of a methodological approach for shape assessment of loose (non-embedded aggregate grains, and demonstrate its use for two types of aggregate, allowing

  8. Grade-Average Method: A Statistical Approach for Estimating ...

    African Journals Online (AJOL)

    Grade-Average Method: A Statistical Approach for Estimating Missing Value for Continuous Assessment Marks. ... Journal of the Nigerian Association of Mathematical Physics. Journal Home · ABOUT ... Open Access DOWNLOAD FULL TEXT ...

  9. Development of building blocks using vegetable oil and recycled aggregate

    Directory of Open Access Journals (Sweden)

    Attia Mohamed I.

    2017-01-01

    Full Text Available The primary objective of this research was to contribute towards greater sustainability of the construction industry in the Qatar by proposing methods to reduce its dependency on primary imported materials. In this investigation, recycled and secondary aggregates (RSA were combined with non-traditional binders to develop a unique method of manufacturing construction and building blocks. Following an extensive phase of laboratory trials and experimentation, it was realised that many types of graded mineral aggregates, when mixed with vegetable oils (virgin or waste at optimal proportions, then compacted and thermally cured at elevated temperatures can readily generate hardened composites that have the mechanical characteristics of conventional building blocks. The resultant blocks have been named “Vegeblocks” and are viewed as viable alternatives to conventional concrete blocks. Furthermore, the research has demonstrated the feasibility of producing Vegeblocks composed of 100% recycled aggregate and discarded waste cooking oil. Based on physical and mineralogical properties, each type of aggregate has an optimum oil content for maximum compressive strength, beyond which, any additional oil will result in reduction in mechanical properties. Acceptable compressive strength values were achieved by thermally curing Vegeblocks at of 170 °C for 24 hours.

  10. Natural aggregate totally replacement by mechanically treated concrete waste

    Directory of Open Access Journals (Sweden)

    Junak Jozef

    2015-06-01

    Full Text Available This paper presents the results obtained from the research focused on the utilization of crushed concrete waste aggregates as a partial or full replacement of 4/8 and 8/16 mm natural aggregates fraction in concrete strength class C 16/20. Main concrete characteristics such as workability, density and compressive strength were studied. Compressive strength testing intervals for samples with recycled concrete aggregates were 2, 7, 14 and 28 days. The amount of water in the mixtures was indicative. For mixture resulting consistency required slump grade S3 was followed. Average density of all samples is in the range of 2250 kg/m3 to 2350 kg/m3. The highest compressive strength after 28 days of curing, 34.68 MPa, reached sample, which contained 100% of recycled material in 4/8 mm fraction and 60% of recycled aggregates in 8/16 mm fraction. This achieved value was only slightly different from the compressive strength 34.41 MPa of the reference sample.

  11. Environmentalism and natural aggregate mining

    Science.gov (United States)

    Drew, L.J.; Langer, W.H.; Sachs, J.S.

    2002-01-01

    Sustaining a developed economy and expanding a developing one require the use of large volumes of natural aggregate. Almost all human activity (commercial, recreational, or leisure) is transacted in or on facilities constructed from natural aggregate. In our urban and suburban worlds, we are almost totally dependent on supplies of water collected behind dams and transported through aqueducts made from concrete. Natural aggregate is essential to the facilities that produce energy-hydroelectric dams and coal-fired powerplants. Ironically, the utility created for mankind by the use of natural aggregate is rarely compared favorably with the environmental impacts of mining it. Instead, the empty quarries and pits are seen as large negative environmental consequences. At the root of this disassociation is the philosophy of environmentalism, which flavors our perceptions of the excavation, processing, and distribution of natural aggregate. The two end-member ideas in this philosophy are ecocentrism and anthropocentrism. Ecocentrism takes the position that the natural world is a organism whose arteries are the rivers-their flow must not be altered. The soil is another vital organ and must not be covered with concrete and asphalt. The motto of the ecocentrist is "man must live more lightly on the land." The anthropocentrist wants clean water and air and an uncluttered landscape for human use. Mining is allowed and even encouraged, but dust and noise from quarry and pit operations must be minimized. The large volume of truck traffic is viewed as a real menace to human life and should be regulated and isolated. The environmental problems that the producers of natural aggregate (crushed stone and sand and gravel) face today are mostly difficult social and political concerns associated with the large holes dug in the ground and the large volume of heavy truck traffic associated with quarry and pit operations. These concerns have increased in recent years as society's demand for

  12. Aggregating energy flexibilities under constraints

    DEFF Research Database (Denmark)

    Valsomatzis, Emmanouil; Pedersen, Torben Bach; Abello, Alberto

    2016-01-01

    The flexibility of individual energy prosumers (producers and/or consumers) has drawn a lot of attention in recent years. Aggregation of such flexibilities provides prosumers with the opportunity to directly participate in the energy market and at the same time reduces the complexity of scheduling...... the energy units. However, aggregated flexibility should support normal grid operation. In this paper, we build on the flex-offer (FO) concept to model the inherent flexibility of a prosumer (e.g., a single flexible consumption device such as a clothes washer). An FO captures flexibility in both time...

  13. Balancing energy flexibilities through aggregation

    DEFF Research Database (Denmark)

    Valsomatzis, Emmanouil; Hose, Katja; Pedersen, Torben Bach

    2014-01-01

    One of the main goals of recent developments in the Smart Grid area is to increase the use of renewable energy sources. These sources are characterized by energy fluctuations that might lead to energy imbalances and congestions in the electricity grid. Exploiting inherent flexibilities, which exist...... in both energy production and consumption, is the key to solving these problems. Flexibilities can be expressed as flex-offers, which due to their high number need to be aggregated to reduce the complexity of energy scheduling. In this paper, we discuss balance aggregation techniques that already during...

  14. Clinical grades: upward bound.

    Science.gov (United States)

    Walsh, Catherine M; Seldomridge, Lisa A

    2005-04-01

    This study examined the relationship of grades earned in paired theory and clinical courses. Data collected during academic years 1997 to 2002 confirmed that grade inflation exists in clinical nursing courses. Problems involved in awarding grades for clinical performance are discussed (e.g., standards of clinical performance, methods used in evaluation of clinical performance, the impossibility of faculty omnipresence, the influence of student effort in grading, the effect of recency, the challenges of keeping good anecdotal records). Solutions to grading problems are proposed, including dividing up performance into agreed-on elements, measurement of these elements on a grading scale that allows for more differentiation of quality in evaluating clinical performance, assigning grades from the beginning of a clinical course, emphasizing all three domains of clinical practice, and evaluating student performance in both laboratory and, clinical settings.

  15. Seventh Grade Students' Conceptions of Global Warming and Climate Change

    Science.gov (United States)

    Shepardson, Daniel P.; Niyogi, Dev; Choi, Soyoung; Charusombat, Umarporn

    2009-01-01

    The purpose of this study was to investigate seventh grade students' conceptions of global warming and climate change. The study was descriptive in nature and involved the collection of qualitative data from 91 seventh grade students from three different schools in the Midwest, USA. An open response and draw and explain assessment instrument was…

  16. Case Study: What Supports Students to Improve Their Grades?

    Science.gov (United States)

    Sieminski, Sandy; Messenger, Julie; Murphy, Sam

    2016-01-01

    This case study considers students who achieved "borderline" (40-45%) grades in their first assignment on a module, but went on to markedly improve their grades over the course of the module. The students were studying nursing and social work at the UK Open University, and they were all sponsored by employers. Semi-structured telephone…

  17. Seventh Grade Students' Conceptions of Global Warming and Climate Change

    Science.gov (United States)

    Shepardson, Daniel P.; Niyogi, Dev; Choi, Soyoung; Charusombat, Umarporn

    2009-01-01

    The purpose of this study was to investigate seventh grade students' conceptions of global warming and climate change. The study was descriptive in nature and involved the collection of qualitative data from 91 seventh grade students from three different schools in the Midwest, USA. An open response and draw and explain assessment instrument was…

  18. Physico-mechanical properties of high performance concrete using different aggregates in presence of silica fume

    Directory of Open Access Journals (Sweden)

    Salah A. Abo-El-Enein

    2014-04-01

    Full Text Available Heavy weight high performance concrete (HPC can be used when particular properties, such as high strength and good radiation shielding are required. Such concrete, using ilmenite and hematite coarse aggregates can significantly have higher specific gravities than those of concrete made with dolomite and air-cooled slag aggregates. Four different concrete mixes with the same cement content and different w/c ratios were designed using normal dolomite aggregate, air-cooled slag by-product and two different types of iron ore aggregates. High performance concrete (grade-M60 can be achieved using superplasticizer to reduce the water/cement ratio; the effect of SF on the performance of concrete was studied by addition of 10% silica fume to the total cement content. The physico-mechanical properties of coarse aggregates and hardened concrete were studied. The results show that, Ilmenite coarse aggregate gives higher physical and mechanical properties than the other aggregates. Also, addition of 10% silica fume developed a stronger and a denser interfacial transition zone (ITZ between concrete particles and the cement matrix. Crushed air-cooled slag can be used to produce a high-strength concrete with better mechanical properties than corresponding concrete made with crushed hematite and ilmenite. Heavy density concrete made with fine aggregates of ilmenite and air-cooled slag are expected to be suitable as shielding materials to attenuate gamma rays.

  19. Evaluation of the performance of aggregate in hot-mix asphalt

    CSIR Research Space (South Africa)

    Komba, Julius J

    2014-07-01

    Full Text Available of the aggregate in an asphalt mix was evaluated. The design grading of the asphalt mixes was similar; the only difference being that the coarse granite fractions (6.7 and 9.5 mm) of the asphalt mix of known good field performance were replaced by coarse quartzite...

  20. Diversity, intent, and aggregated search

    NARCIS (Netherlands)

    de Rijke, M.

    2014-01-01

    Diversity, intent and aggregated search are three core retrieval concepts that receive significant attention. In search result diversification one typically considers the relevance of a document in light of other retrieved documents. The goal is to identify the probable "aspects" of an ambiguous

  1. Diversity, intent, and aggregated search

    NARCIS (Netherlands)

    M. de Rijke

    2014-01-01

    Diversity, intent and aggregated search are three core retrieval concepts that receive significant attention. In search result diversification one typically considers the relevance of a document in light of other retrieved documents. The goal is to identify the probable "aspects" of an ambiguous que

  2. Quantitative investigations of aggregate systems.

    Science.gov (United States)

    Rai, D K; Beaucage, G; Jonah, E O; Britton, D T; Sukumaran, S; Chopra, S; Gonfa, G Goro; Härting, M

    2012-07-28

    Nanomaterials with disordered, ramified structure are increasingly being used for applications where low cost and enhanced performance are desired. A particular example is the use in printed electronics of inorganic conducting and semiconducting nanoparticles. The electrical, as well as other physical properties depend on the arrangement and connectivity of the particles in such aggregate systems. Quantification of aggregate structure and development of structure/property relationships is difficult and progress in the application of these materials in electronics has mainly been empirical. In this paper, a scaling model is used to parameterize the structure of printed electronic layers. This model has chiefly been applied to polymers but surprisingly it shows applicability to these nanolayers. Disordered structures of silicon nanoparticles forming aggregates are investigated using small angle x-ray scattering coupled with the scaling model. It is expected that predictions using these structural parameters can be made for electrical properties. The approach may have wide use in understanding and designing nano-aggregates for electronic devices.

  3. Cyclosporine A enhances platelet aggregation.

    Science.gov (United States)

    Grace, A A; Barradas, M A; Mikhailidis, D P; Jeremy, J Y; Moorhead, J F; Sweny, P; Dandona, P

    1987-12-01

    In view of the reported increase in thromboembolic episodes following cyclosporine A (CyA) therapy, the effect of this drug on platelet aggregation and thromboxane A2 release was investigated. The addition of CyA, at therapeutic concentrations to platelet rich plasma from normal subjects in vitro was found to increase aggregation in response to adrenaline, collagen and ADP. Ingestion of CyA by healthy volunteers was also associated with enhanced platelet aggregation. The CyA-mediated enhancement of aggregation was further enhanced by the addition in vitro of therapeutic concentrations of heparin. Platelets from renal allograft recipients treated with CyA also showed hyperaggregability and increased thromboxane A2 release, which were most marked at "peak" plasma CyA concentration and less so at "trough" concentrations. Platelet hyperaggregability in renal allograft patients on long-term CyA therapy tended to revert towards normal following the replacement of CyA with azathioprine. Hypertensive patients with renal allografts on nifedipine therapy had normal platelet function and thromboxane release in spite of CyA therapy. These observations suggest that CyA-mediated platelet activation may contribute to the pathogenesis of the thromboembolic phenomena associated with the use of this drug. The increased release of thromboxane A2 (a vasoconstrictor) may also play a role in mediating CyA-related nephrotoxicity.

  4. Open access

    CERN Document Server

    Suber, Peter

    2012-01-01

    The Internet lets us share perfect copies of our work with a worldwide audience at virtually no cost. We take advantage of this revolutionary opportunity when we make our work "open access": digital, online, free of charge, and free of most copyright and licensing restrictions. Open access is made possible by the Internet and copyright-holder consent, and many authors, musicians, filmmakers, and other creators who depend on royalties are understandably unwilling to give their consent. But for 350 years, scholars have written peer-reviewed journal articles for impact, not for money, and are free to consent to open access without losing revenue. In this concise introduction, Peter Suber tells us what open access is and isn't, how it benefits authors and readers of research, how we pay for it, how it avoids copyright problems, how it has moved from the periphery to the mainstream, and what its future may hold. Distilling a decade of Suber's influential writing and thinking about open access, this is the indispe...

  5. Open access and scholarly communication, part 4

    CERN Document Server

    Eden, Brad

    2009-01-01

    This fourth e-book on the subject of open access in the academic field includes a Latin American case study on open access penetration, a paper from Germany on the promotion of OA illustrated by a project at the University of Konstanz, and a case study on OA at Bioline International, a non-profit scholarly publications aggregator, distributor, publisher and publishing assistance service.

  6. Sequence-dependent internalization of aggregating peptides.

    Science.gov (United States)

    Couceiro, José R; Gallardo, Rodrigo; De Smet, Frederik; De Baets, Greet; Baatsen, Pieter; Annaert, Wim; Roose, Kenny; Saelens, Xavier; Schymkowitz, Joost; Rousseau, Frederic

    2015-01-02

    Recently, a number of aggregation disease polypeptides have been shown to spread from cell to cell, thereby displaying prionoid behavior. Studying aggregate internalization, however, is often hampered by the complex kinetics of the aggregation process, resulting in the concomitant uptake of aggregates of different sizes by competing mechanisms, which makes it difficult to isolate pathway-specific responses to aggregates. We designed synthetic aggregating peptides bearing different aggregation propensities with the aim of producing modes of uptake that are sufficiently distinct to differentially analyze the cellular response to internalization. We found that small acidic aggregates (≤500 nm in diameter) were taken up by nonspecific endocytosis as part of the fluid phase and traveled through the endosomal compartment to lysosomes. By contrast, bigger basic aggregates (>1 μm) were taken up through a mechanism dependent on cytoskeletal reorganization and membrane remodeling with the morphological hallmarks of phagocytosis. Importantly, the properties of these aggregates determined not only the mechanism of internalization but also the involvement of the proteostatic machinery (the assembly of interconnected networks that control the biogenesis, folding, trafficking, and degradation of proteins) in the process; whereas the internalization of small acidic aggregates is HSF1-independent, the uptake of larger basic aggregates was HSF1-dependent, requiring Hsp70. Our results show that the biophysical properties of aggregates determine both their mechanism of internalization and proteostatic response. It remains to be seen whether these differences in cellular response contribute to the particular role of specific aggregated proteins in disease.

  7. Protein aggregation in bacteria: the thin boundary between functionality and toxicity.

    Science.gov (United States)

    Bednarska, Natalia G; Schymkowitz, Joost; Rousseau, Frederic; Van Eldere, Johan

    2013-09-01

    Misfolding and aggregation of proteins have a negative impact on all living organisms. In recent years, aggregation has been studied in detail due to its involvement in neurodegenerative diseases, including Alzheimer's, Parkinson's and Huntington's diseases, and type II diabetes--all associated with accumulation of amyloid fibrils. This research highlighted the central importance of protein homeostasis, or proteostasis for short, defined as the cellular state in which the proteome is both stable and functional. It implicates an equilibrium between synthesis, folding, trafficking, aggregation, disaggregation and degradation. In accordance with the eukaryotic systems, it has been documented that protein aggregation also reduces fitness of bacterial cells, but although our understanding of the cellular protein quality control systems is perhaps most detailed in bacteria, the use of bacterial proteostasis as a drug target remains little explored. Here we describe protein aggregation as a normal physiological process and its role in bacterial virulence and we shed light on how bacteria defend themselves against the toxic threat of aggregates. We review the impact of aggregates on bacterial viability and look at the ways that bacteria use to maintain a balance between aggregation and functionality. The proteostasis in bacteria can be interrupted via overexpression of proteins, certain antibiotics such as aminoglycosides, as well as antimicrobial peptides--all leading to loss of cell viability. Therefore intracellular protein aggregation and disruption of proteostatic balance in bacteria open up another strategy that should be explored towards the discovery of new antimicrobials.

  8. Open Brief

    Directory of Open Access Journals (Sweden)

    Andrew Leach

    2013-11-01

    Full Text Available To commence the thirtieth annual conference of the Society of Architectural Historians, Australia and New Zealand (SAHANZ, held on Australia’s Gold Coast in July 2013, ten delegates were invited with very little warning to take five minutes and one image to offer a provocation on the open matters of architectural history in the present moment. The term “open” was taken as the conference theme—a device used by SAHANZ meetings not so much to define the scope of papers presented as to declare the conference flavour year by year. It was not, therefore, an open conference (anything goes so much as a conference on open issues (where, indeed, to go.  The ten interlocutors were invited after the conference to document their interventions and they are presented here as a record of the preoccupations of a specific moment and institutional geography with all the idiosyncrasies and commonalities it might reveal to a broader audience.

  9. A Simple Alternative to Grading

    Science.gov (United States)

    Potts, Glenda

    2010-01-01

    In this article, the author investigates whether an alternative grading system (contract grading) would yield the same final grades as traditional grading (letter grading), and whether or not it would be accepted by students. The author states that this study demonstrated that contract grading was widely, and for the most part, enthusiastically…

  10. Open Education and the Open Science Economy

    Science.gov (United States)

    Peters, Michael A.

    2009-01-01

    Openness as a complex code word for a variety of digital trends and movements has emerged as an alternative mode of "social production" based on the growing and overlapping complexities of open source, open access, open archiving, open publishing, and open science. This paper argues that the openness movement with its reinforcing structure of…

  11. Aggregation behaviour of amphiphilic cyclodextrins: the nucleation stage by atomistic molecular dynamics simulations

    Directory of Open Access Journals (Sweden)

    Giuseppina Raffaini

    2015-12-01

    Full Text Available Amphiphilically modified cyclodextrins may form various supramolecular aggregates. Here we report a theoretical study of the aggregation of a few amphiphilic cyclodextrins carrying hydrophobic thioalkyl groups and hydrophilic ethylene glycol moieties at opposite rims, focusing on the initial nucleation stage in an apolar solvent and in water. The study is based on atomistic molecular dynamics methods with a “bottom up” approach that can provide important information about the initial aggregates of few molecules. The focus is on the interaction pattern of amphiphilic cyclodextrin (aCD, which may interact by mutual inclusion of the substituent groups in the hydrophobic cavity of neighbouring molecules or by dispersion interactions at their lateral surface. We suggest that these aggregates can also form the nucleation stage of larger systems as well as the building blocks of micelles, vesicle, membranes, or generally nanoparticles thus opening new perspectives in the design of aggregates correlating their structures with the pharmaceutical properties.

  12. Fluctuations in protein aggregation: Design of preclinical screening for early diagnosis of neurodegenerative disease

    CERN Document Server

    Costantini, Giulio; Taloni, Alessandro; Buell, Alexander K; Zapperi, Stefano; La Porta, Caterina A M

    2016-01-01

    Autocatalytic fibril nucleation has recently been proposed to be a determining factor for the spread of neurodegenerative diseases, but the same process could also be exploited to amplify minute quantities of protein aggregates in a diagnostic context. Recent advances in microfluidic technology allow analysis of protein aggregation in micron-scale samples potentially enabling such diagnostic approaches, but the theoretical foundations for the analysis and interpretation of such data are so far lacking. Here we study computationally the onset of protein aggregation in small volumes and show that the process is ruled by intrinsic fluctuations whose volume dependent distribution we also estimate theoretically. Based on these results, we develop a strategy to quantify in silico the statistical errors associated with the detection of aggregate containing samples. Our work opens a new perspective on the forecasting of protein aggregation in asymptomatic subjects.

  13. Aggregation behaviour of amphiphilic cyclodextrins: the nucleation stage by atomistic molecular dynamics simulations

    Science.gov (United States)

    Mazzaglia, Antonino; Ganazzoli, Fabio

    2015-01-01

    Summary Amphiphilically modified cyclodextrins may form various supramolecular aggregates. Here we report a theoretical study of the aggregation of a few amphiphilic cyclodextrins carrying hydrophobic thioalkyl groups and hydrophilic ethylene glycol moieties at opposite rims, focusing on the initial nucleation stage in an apolar solvent and in water. The study is based on atomistic molecular dynamics methods with a “bottom up” approach that can provide important information about the initial aggregates of few molecules. The focus is on the interaction pattern of amphiphilic cyclodextrin (aCD), which may interact by mutual inclusion of the substituent groups in the hydrophobic cavity of neighbouring molecules or by dispersion interactions at their lateral surface. We suggest that these aggregates can also form the nucleation stage of larger systems as well as the building blocks of micelles, vesicle, membranes, or generally nanoparticles thus opening new perspectives in the design of aggregates correlating their structures with the pharmaceutical properties. PMID:26734094

  14. Role of streams in myxobacteria aggregate formation

    Science.gov (United States)

    Kiskowski, Maria A.; Jiang, Yi; Alber, Mark S.

    2004-10-01

    Cell contact, movement and directionality are important factors in biological development (morphogenesis), and myxobacteria are a model system for studying cell-cell interaction and cell organization preceding differentiation. When starved, thousands of myxobacteria cells align, stream and form aggregates which later develop into round, non-motile spores. Canonically, cell aggregation has been attributed to attractive chemotaxis, a long range interaction, but there is growing evidence that myxobacteria organization depends on contact-mediated cell-cell communication. We present a discrete stochastic model based on contact-mediated signaling that suggests an explanation for the initialization of early aggregates, aggregation dynamics and final aggregate distribution. Our model qualitatively reproduces the unique structures of myxobacteria aggregates and detailed stages which occur during myxobacteria aggregation: first, aggregates initialize in random positions and cells join aggregates by random walk; second, cells redistribute by moving within transient streams connecting aggregates. Streams play a critical role in final aggregate size distribution by redistributing cells among fewer, larger aggregates. The mechanism by which streams redistribute cells depends on aggregate sizes and is enhanced by noise. Our model predicts that with increased internal noise, more streams would form and streams would last longer. Simulation results suggest a series of new experiments.

  15. The Open

    Directory of Open Access Journals (Sweden)

    Saitya Brata Das

    2009-12-01

    Full Text Available In the Open darkness and light, remembrance and oblivion, coming into existence and disappearing in death play their originary co-belonging, or co-figuration. Existence belongs to this opening and is exposed to its coming to presence: it is on the basis of this originary opening, this originary historical which is revealed to this mortal being called ‘man,’ on the basis of this revelation, man founds something like politics and history. There thus comes into existence out of this freedom, out of this “play space”2, this field called ‘polis’3 where there takes place war and festival, where historical revolutions tear apart history, brings ruptures and discontinuities in the very mode of his existence, where man seeks the foundation of his own foundation (which is his metaphysical task , where occurs the dialectics of negativity between man and man, where man puts at stake his own death, his own dissolution, and by the power of his own dissolution stands in relation to the total world that he seeks to dominate. This means that man’s attempts to metaphysically found his own political and historical existence must presuppose a far more originary non-foundation, the differentiating revealing of the open, the ungrounded spacing play, or playing space of natality and mortality.

  16. Open innovation

    DEFF Research Database (Denmark)

    West, Joel; Bogers, Marcel

    2017-01-01

    by small, new, and not-for-profit organizations, as well as the linkage of individual actions and motivations to open innovation. Other opportunities include better measuring the costs, benefits, antecedents, mediators and moderators of the effects of OI on performance, and understanding why and how OI...

  17. Experimental study on microstructure and structural behaviour of recycled aggregate concrete

    OpenAIRE

    Etxeberria Larrañaga, Miren

    2004-01-01

    The use of recycled aggregates in concrete opens a whole new range of possibilities in the reuse of materials in the building industry. This could be an important breakthrough for our society in our endeavours towards sustainable development. The trend of the utilisation of recycled aggregates is the solution to the problem of an excess of waste material, not forgetting the parallel trend of improvement of final product quality. The utilisation of waste construction materials has to be relat...

  18. AGGREGATE RATING MODEL IN THE TOURISM INDUSTRY

    Directory of Open Access Journals (Sweden)

    Maris Angela

    2014-07-01

    Full Text Available In the paper the authors present a model aggregate rating based on credit-scoring models, banking models and their rating model. Multi-criteria approach and an aggregate model better capture business risk of the company.

  19. Open Source, Open Access, Open Review, Open Data. Initiativen zu mehr Offenheit in der digitalen Welt

    OpenAIRE

    Herb, Ulrich

    2011-01-01

    The article discusses the principles of openess, open access and open availability of information based on the examples of open access to scientific information, open government data, open geographical data and open source software.

  20. Open Source, Open Access, Open Review, Open Data. Initiativen zu mehr Offenheit in der digitalen Welt

    OpenAIRE

    Herb, Ulrich

    2011-01-01

    The article discusses the principles of openess, open access and open availability of information based on the examples of open access to scientific information, open government data, open geographical data and open source software.

  1. Protein aggregation in salt solutions

    Science.gov (United States)

    Kastelic, Miha; Kalyuzhnyi, Yurij V.; Hribar-Lee, Barbara; Dill, Ken A.; Vlachy, Vojko

    2015-01-01

    Protein aggregation is broadly important in diseases and in formulations of biological drugs. Here, we develop a theoretical model for reversible protein–protein aggregation in salt solutions. We treat proteins as hard spheres having square-well-energy binding sites, using Wertheim’s thermodynamic perturbation theory. The necessary condition required for such modeling to be realistic is that proteins in solution during the experiment remain in their compact form. Within this limitation our model gives accurate liquid–liquid coexistence curves for lysozyme and γ IIIa-crystallin solutions in respective buffers. It provides good fits to the cloud-point curves of lysozyme in buffer–salt mixtures as a function of the type and concentration of salt. It than predicts full coexistence curves, osmotic compressibilities, and second virial coefficients under such conditions. This treatment may also be relevant to protein crystallization. PMID:25964322

  2. Acetone:isomedzation and aggregation

    Institute of Scientific and Technical Information of China (English)

    HU Zhan; JIN Ming-xing; XU Xue-song; CHENG Xi-hui; DING Da-jun

    2006-01-01

    The advanced experimental and theoretical techniques enable us to obtain information on the rearrangement of atoms or molecules in a reaction nowadays.As an example,we report on our research work on acetone isomerization and aggregation to give an insight into the reaction pathways,the products and their structures,and the growth regularity of aggregation.The evidences on the structural change of acetone and the stability of acetone clusters are found by a laser ionization mass spectrometer and the results are interpreted from theoretical analysis based on the DFT/B3LYP method.Various isomerization channels of acetone have been established and the optimal structures of the neutral clusters (CH3COCH3)n and the protonated acetone clusters (CH3COCHa)n H+ for n=1-7 have been determined.

  3. Intuitionistic fuzzy aggregation and clustering

    CERN Document Server

    Xu, Zeshui

    2012-01-01

    This book offers a systematic introduction to the clustering algorithms for intuitionistic fuzzy values, the latest research results in intuitionistic fuzzy aggregation techniques, the extended results in interval-valued intuitionistic fuzzy environments, and their applications in multi-attribute decision making, such as supply chain management, military system performance evaluation, project management, venture capital, information system selection, building materials classification, and operational plan assessment, etc.

  4. Familial aggregation of cluster headache

    Directory of Open Access Journals (Sweden)

    Simao Cruz

    2013-11-01

    Full Text Available Several studies suggest a strong familial aggregation for cluster headache (CH, but so far none of them have included subjects with probable cluster headache (PCH in accordance with the International Classification of Headache Disorders. Objective To identify cases of probable cluster headache and to assess the familial aggregation of cluster headache by including these subjects. Method Thirty-six patients attending a headache consultation and diagnosed with trigeminal autonomic headaches were subjected to a questionnaire-based interview. A telephone interview was also applied to all the relatives who were pointed out as possibly affected as well as to some of the remaining relatives. Results Twenty-four probands fulfilled the criteria for CH or PCH; they had 142 first-degree relatives, of whom five were found to have CH or PCH, including one case of CH sine headache. The risk for first-degree relatives was observed to be increased by 35- to 46-fold. Conclusion Our results suggest a familial aggregation of cluster headache in the Portuguese population.

  5. Network Provisioning Using Multimedia Aggregates

    Directory of Open Access Journals (Sweden)

    Joan Vila-Carbó

    2008-01-01

    Full Text Available Multimedia traffic makes network provisioning a key issue. Optimal provisioning of network resources is crucial for reducing the service cost of multimedia transmission. Multimedia traffic requires not only provisioning bandwidth and buffer resources in the network but also guaranteeing a given maximum end-to-end delay. In this paper we present methods and tools for the optimal dimensioning of networks based on multimedia aggregates. The proposed method minimises the network resources reservations of traffic aggregates providing a bounded delay. The paper also introduces several methods to generate multimedia traffic aggregation using real video traces. The method is evaluated using a network topology based on the European GÉANT network. The results of these simulations allow us to discover the relationship between a required delay and the necessary bandwidth reservation (or the achievable utilisation limit. An interesting conclusion of these scenarios is that, following several recommendations, the network utilisation can reach values of around 80% or higher.

  6. OpenAPC. Open-Access-Publikationskosten als Open Data

    OpenAIRE

    Tullney, Marco

    2015-01-01

    Präsentationsfolien zum Vortrag „OpenAPC. Open-Access-Publikationskosten als Open Data“ in der Session „Ausgestaltung eines wissenschaftsadäquaten APC-Marktes: Grundsätze, Finanzierungsansätze und Management“ der Open-Access-Tage 2015 in Zürich (https://www.open-access.net/community/open-access-tage/open-access-tage-2015-zuerich/programm/#c1974)

  7. Pallet part grading trainer

    Science.gov (United States)

    Deborah F. Cook; Philip A. Araman; Matthew F. Winn

    2000-01-01

    A computerized pallet grading training system was developed to facilitate the production of higher quality pallets. Higher quality pallets would be more durable and could be re-used many times, resulting in long-term savings. Schmoldt et al. (1993) evaluated the economic impact of grading and sorting pallet parts. They determined that higher quality pallets produced by...

  8. Beef grading by ultrasound

    Science.gov (United States)

    Gammell, P. M.

    1981-01-01

    Reflections in ultrasonic A-scan signatures of beef carcasses indicate USDA grade. Since reflections from within muscle are determined primarily by fat/muscle interface, richness of signals is direct indication of degree of marbling and quality. Method replaces subjective sight and feel tests by individual graders and is applicable to grade analysis of live cattle.

  9. Grading Exceptional Learners

    Science.gov (United States)

    Jung, Lee Ann; Guskey, Thomas R.

    2010-01-01

    Teachers often grapple with the challenge of giving report card grades to students with learning disabilities and English language learners. The authors offer a five-step model that "offers a fair, accurate, and legal way to adapt the grading process for exceptional learners." The model begins with a high-quality reporting system for all students…

  10. Minimum Grading, Maximum Learning

    Science.gov (United States)

    Carey, Theodore; Carifio, James

    2011-01-01

    Fair and effective schools should assign grades that align with clear and consistent evidence of student performance (Wormeli, 2006), but when a student's performance is inconsistent, traditional grading practices can prove inadequate. Understanding this, increasing numbers of schools have been experimenting with the practice of assigning minimum…

  11. Green Concrete from Sustainable Recycled Coarse Aggregates: Mechanical and Durability Properties

    Directory of Open Access Journals (Sweden)

    Neeraj Jain

    2015-01-01

    Full Text Available Present investigations deal with the development of green concrete (M 30 grade using recycled coarse aggregates for sustainable development. Characterization of recycled coarse aggregates showed that physical and mechanical properties are of inferior quality and improvement in properties was observed after washing due to removal of old weak mortar adhered on its surface. The influence of natural coarse aggregates replacement (50 and 100% with recycled coarse aggregate on various mechanical and durability properties of hardened concrete were discussed and compared with controls at different w/c ratio. Improvements in all the engineering properties of hardened concrete were observed using washed recycled coarse aggregates. The compressive strength of 28-day hardened concrete containing 100% washed recycled aggregate was slightly lower (7% than concrete prepared with natural aggregates. Water absorption, carbonation, and rapid chloride penetration test were conducted to assess the durability of the concrete. Concrete was found moderately permeable for chloride ions penetration and no carbonation was observed in all the concrete mixes studied.

  12. Physical and mechanical properties of mortars containing PET and PC waste aggregates.

    Science.gov (United States)

    Hannawi, Kinda; Kamali-Bernard, Siham; Prince, William

    2010-11-01

    Non-biodegradable plastic aggregates made of polycarbonate (PC) and polyethylene terephthalate (PET) waste are used as partial replacement of natural aggregates in mortar. Various volume fractions of sand 3%, 10%, 20% and 50% are replaced by the same volume of plastic. This paper investigates the physical and mechanical properties of the obtained composites. The main results of this study show the feasibility of the reuse of PC and PET waste aggregates materials as partial volume substitutes for natural aggregates in cementitious materials. Despite of some drawbacks like a decrease in compressive strength, the use of PC and PET waste aggregates presents various advantages. A reduction of the specific weight of the cementitious materials and a significant improvement of their post-peak flexural behaviour are observed. The calculated flexural toughness factors increase significantly with increasing volume fraction of PET and PC-aggregates. Thus, addition of PC and PET plastic aggregates in cementitious materials seems to give good energy absorbing materials which is very interesting for several civil engineering applications like structures subjected to dynamic or impact efforts. The present study has shown quite encouraging results and opened new way for the recycling of PC waste aggregate in cement and concrete composites. Copyright © 2010 Elsevier Ltd. All rights reserved.

  13. [Lysophosphatidic acid and human erythrocyte aggregation].

    Science.gov (United States)

    Sheremet'ev, Iu A; Popovicheva, A N; Levin, G Ia

    2014-01-01

    The effects of lysophosphatidic acid on the morphology and aggregation of human erythrocytes has been studied. Morphology of erythrocytes and their aggregates were studied by light microscopy. It has been shown that lysophosphatidic acid changes the shape of red blood cells: diskocyte become echinocytes. Aggregation of red blood cells (rouleaux) was significantly reduced in autoplasma. At the same time there is a strong aggregation of echinocytes. This was accompanied by the formation of microvesicles. Adding normal plasma to echinocytes restores shape and aggregation of red blood cells consisting of "rouleaux". A possible mechanism of action of lysophosphatidic acid on erythrocytes is discussed.

  14. [AGGREGATION OF METABOLICALLY DEPLETED HUMAN ERYTHROCYTES].

    Science.gov (United States)

    Sheremet'ev, Yu A; Popovicheva, A N; Rogozin, M M; Levin, G Ya

    2016-01-01

    An aggregation of erythrocytes in autologous plasma after blood storage for 14 days at 4 °C was studied using photometry and light microscopy. The decrease of ATP content, the formation of echinocytes and spheroechinocytes, the decrease of rouleaux form of erythrocyte aggregation were observed during the storage. On the other hand the aggregates of echinocytes were formed in the stored blood. The addition of plasma from the fresh blood didn't restore the normal discocytic shape and aggregation of erythrocytes in the stored blood. The possible mechanisms of erythrocytes and echinocytes aggregation are discussed.

  15. An exact approach for aggregated formulations

    DEFF Research Database (Denmark)

    Gamst, Mette; Spoorendonk, Simon

    cause an infeasible solution. In this paper, we consider (mixed) integer program formulations and propose a method for ensuring an optimal solution to the original (disaggregated) problem using an aggregated formulation. The method is based on Benders’ decomposition on a combination of the disaggregated...... mathematical formulation and the aggregated formulation. The method allows usage of relaxed aggregated formulations and enables branching on both aggregated and disaggregated variables. Also, the method guarantees an LP bound at least as good as those for the disaggregated and aggregated formulations...

  16. Ortographic difficulties in writing at a basic grade level

    Directory of Open Access Journals (Sweden)

    Maria Cristina Rodrigues Azevedo Joly

    2009-12-01

    Full Text Available This study aimed to identify the performance in children’s writing at a basic grade level. A written test was applied to 546 grade 2 or 3 boys and girls (aged 7 to 13 in public and private schools from the State of São Paulo. The results showed that the grade 3 participants presented a better performance than the grade 2 participants even though both groups have achieved the same maximum and minimum scores. It was confirmed that participants had more difficulty with words containing compound syllables, while words with aggregated consonants and digraphs were associated with the highest rate of correct answers. Furthermore, students from private school revealed more competence in orthographic writing than those coming from public schools. As to gender differences, there were no significant differences in performance for compound and complex syllables items though for other words, girls had better scores.   Keywords: writing; academic achievement; evaluation.

  17. Characterizations of Graded Distributive Modules

    Institute of Scientific and Technical Information of China (English)

    Qinghua Chen; Chang'an Li

    2002-01-01

    In this paper, we give some characterizations of graded distributive modules, prove some interesting results between graded rings (modules) and lattices under finiteness conditions, and investigate the direct sum of graded distributive modules in terms of orders of graded submodules and homomorphisms of graded factor modules.

  18. Paperless Grades and Faculty Development.

    Science.gov (United States)

    Hardy, James C.; Jones, Dennis; Turner, Sandy

    2003-01-01

    Provides overview of process of switching from paper-based grade reporting to computer-based grading. Authors found that paperless grading decreased number of errors, made student access more immediate, and reduced costs incurred by purchasing and storing grade-scanning sheets. Authors also argue that direct entry grading encourages faculty to…

  19. Aggregation of Diesel Contaminated Soil for Bioremediation

    Institute of Scientific and Technical Information of China (English)

    Yu Ying; Shi Xiu-hong; Li Song; Xu Jing-gang

    2014-01-01

    Diesel contaminated soil (DCS) contained a large amount of the hydrocarbons and salt which was dominated by soluble sodium chloride. Aggregation process which made the desired aggregate size distribution could speed up the degradation rate of the hydrocarbons since the aggregated DCS had better physical characteristics than the non-aggregated material. Artificial aggregation increased pores >30 µm by approximately 5% and reduced pores <1 µm by 5%, but did not change the percentage of the pores between 1 and 30 µm. The saturated hydraulic conductivity of non-aggregated DCS was 5×10-6 m• s-l, but it increased to 1×10-5 m• s-l after aggregation. The compression index of the non-aggregated DCS was 0.0186; however, the artificial aggregates with and without lime were 0.031 and 0.028, respectively. DCS could be piled 0.2 m deep without artificial aggregation; however, it could be applied 0.28 m deep when artificial aggregates were formed without limiting O2 transport.

  20. Bouncing Behavior of Microscopic Dust Aggregates

    CERN Document Server

    Seizinger, Alexander

    2013-01-01

    Context: Bouncing collisions of dust aggregates within the protoplanetary may have a significant impact on the growth process of planetesimals. Yet, the conditions that result in bouncing are not very well understood. Existing simulations studying the bouncing behavior used aggregates with an artificial, very regular internal structure. Aims: Here, we study the bouncing behavior of sub-mm dust aggregates that are constructed applying different sample preparation methods. We analyze how the internal structure of the aggregate alters the collisional outcome and determine the influence of aggregate size, porosity, collision velocity, and impact parameter. Methods: We use molecular dynamics simulations where the individual aggregates are treated as spheres that are made up of several hundred thousand individual monomers. The simulations are run on GPUs. Results: Statistical bulk properties and thus bouncing behavior of sub-mm dust aggregates depend heavily on the preparation method. In particular, there is no uni...

  1. Integration, aggregation and exchange of farming device data

    DEFF Research Database (Denmark)

    Iftikhar, Nadeem

    2009-01-01

    Most of the farming devices produce massive amounts of data. In most of the cases, it is necessary to store this data at a central location for further processing. Due to the huge volumes of data, strategies for data aggregation procedures are very important, in order to avoid oversized data sets....... There is also an increasing need to share or exchange data with other stack holders in the farming business based on farming standards. This paper presents an integrated, effective, easy-to-use and flexible solution, which enables the farmers to integrate data from several farming devices, aggregate data...... at different granularity levels and exchange data bi-directionally with other farming systems. The paper also describes the implementation strategy based on a case study using farming standards and open source technologies....

  2. Open Images

    DEFF Research Database (Denmark)

    Sanderhoff, Merete

    2013-01-01

    Museums around the world hold enormous troves of public domain artworks. In digitized form, they can be powerful tools for research and learning, as well as building blocks, in the hands of students, teachers, scholars, developers, and creative people. By opening up their digitized assets for reuse......, museums have a unique opportunity to broaden the scope of their public mission to serve and educate the public on 21st century media terms. What could be controversial about that? Art museums have a long legacy of restricting access to high quality images of artworks in order to protect them from improper...

  3. Open University

    CERN Document Server

    Pentz,M

    1975-01-01

    Michel Pentz est née en Afrique du Sud et venu au Cern en 1957 comme physicien et président de l'associaion du personnel. Il est également fondateur du mouvement Antiapartheid de Genève et a participé à la fondation de l'Open University en Grande-Bretagne. Il nous parle des contextes pédagogiques, culturels et nationaux dans lesquels la méthode peut s'appliquer.

  4. Grading for Understanding - Standards-Based Grading

    Science.gov (United States)

    Zimmerman, Todd

    2017-01-01

    Standards-based grading (SBG), sometimes called learning objectives-based assessment (LOBA), is an assessment model that relies on students demonstrating mastery of learning objectives (sometimes referred to as standards). The goal of this grading system is to focus students on mastering learning objectives rather than on accumulating points. I have used SBG in an introductory physics course for the past five years and worked with several physics faculty members to implement SBG in the first and second semester of algebra-based and calculus-based introductory physics courses at a primarily undergraduate comprehensive public university with class sizes of 48 students. In this article I will discuss methods for implementing SBG in a physics class.

  5. Mars Atmospheric Aggregation System API

    Data.gov (United States)

    National Aeronautics and Space Administration — The {MAAS} API is an open source REST API built to help make it easier and more efficient to build interactive applications that want to utilize the wealth of...

  6. PERCOLATION OF RANDOM CYLINDER AGGREGATES

    Directory of Open Access Journals (Sweden)

    Dominique Jeulin

    2011-05-01

    Full Text Available The percolation threshold ρc of Boolean models of cylinders with their axis parallel to a given direction is studied by means of simulations. An efficient method of construction of percolating connected components was developed, and is applied to one or two scales Boolean model, in order to simulate the presence of aggregates. The invariance of the percolation threshold with respect to affine transformations in the common direction of the axis of cylinders is approximately satisfied on simulations. The prediction of the model (ρc close to 0.16 is consistent with experimental measurements on plasma spray coatings, which motivated this study.

  7. Nebraska Science Standards: Grades K-12

    Science.gov (United States)

    Nebraska Department of Education, 2010

    2010-01-01

    This publication presents the Nebraska Science Standards for Grades K-12. The standards are presented according to the following grades: (1) Grades K-2; (2) Grades 3-5; (3) Grades 6-8; and (4) Grades 9-12.

  8. Chemical modelling of Alkali Silica reaction: Influence of the reactive aggregate size distribution

    Energy Technology Data Exchange (ETDEWEB)

    Poyet, S. [CEA Saclay, DEN/DANS/DPC/SCCME/LECBA, F-91191 Gif Sur Yvette, (France); Sellier, A. [UPS, LMDC, INSA Toulouse, F-33077 Bordeaux 4, (France); Capra, B. [Oxand SA, F-77210 Avon (France); Foray, G. [Univ Lyon 1, L2MS, PETRA GC, F-69622 Villeurbanne (France); Torrenti, J.M. [IRSN, F-92262 Fontenay Aux Roses (France); Cognon, H. [EdF/DER Les Renardieres, F-77818 Moret Sur Loing (France); Bourdarot, E. [CIH Savoie Technolac, F-73373 Le Bourget du Lac (France)

    2007-07-01

    This article presents a new model which aims at predicting the expansion induced by Alkali Silica Reaction (ASR) and describing the chemical evolution of affected concretes. It is based on the description of the transport and reaction of alkalis and calcium ions within a Relative Elementary Volume (REV). It takes into account the influence of the reactive aggregate size grading on ASR, i.e. the effect of the simultaneous presence of different sized reactive aggregates within concrete. The constitutive equations are detailed and fitted using experimental results. Results from numerical simulations are presented and compared with experiments. (authors)

  9. Functionally Graded Media

    OpenAIRE

    Campos, Cédric M.; Epstein, Marcelo; De León, Manuel

    2007-01-01

    The notions of uniformity and homogeneity of elastic materials are reviewed in terms of Lie groupoids and frame bundles. This framework is also extended to consider the case Functionally Graded Media, which allows us to obtain some homogeneity conditions.

  10. The Grade Contract Revisited

    Science.gov (United States)

    Bornscheuer, Joan H.

    1976-01-01

    Adaptations of and variations on the grade contract system are described with emphasis on individualized instruction, fair evaluation, and learner-oriented classes. The method used is described, and results are assessed. (Author/RM)

  11. Aggregation kinetics of a simulated telechelic polymer

    Science.gov (United States)

    Wilson, Mark; Rabinovitch, Avinoam; Baljon, Arlette R. C.

    2011-12-01

    We investigate the aggregation kinetics of a simulated telechelic polymer gel. In the hybrid molecular dynamics (MD)/Monte Carlo (MC) algorithm, aggregates of associating end groups form and break according to MC rules, while the position of the polymers in space is dictated by MD. As a result, the aggregate sizes change over time. In order to describe this aggregation process, we employ master equations. They define changes in the number of aggregates of a certain size in terms of reaction rates. These reaction rates indicate the likelihood that two aggregates combine to form a large one, or that a large aggregate splits into two smaller parts. The reaction rates are obtained from the simulations for a range of temperatures. Our results indicate that the rates are not only temperature dependent, but also a function of the sizes of the aggregates involved in the reaction. Using the measured rates, solutions to the master equations are shown to be stable and in agreement with the aggregate size distribution, as obtained directly from simulation data. Furthermore, we show how temperature-induced variations in these rates give rise to the observed changes in the aggregate distribution that characterizes the sol-gel transition.

  12. Pyridine Aggregation in Helium Nanodroplets

    Science.gov (United States)

    Nieto, Pablo; Poerschke, Torsten; Habig, Daniel; Schwaab, Gerhard; Havenith, Martina

    2012-06-01

    Pyridine crystals show the unusual property of isotopic polymorphism. Experimentally it has been observed that deuterated pyridine crystals exist in two phases while non-deuterated pyridine does not show a phase transition. Therefore, although isotopic substitution is the smallest possible modification of a molecule it greatly affects the stability of pyridine crystals. A possible experimental approach in order to understand this striking effect might be the study of pyridine aggregation for small clusters. By embedding the clusters in helium nanodroplets the aggregates can be stabilized and studied by means of Infrared Depletion Spectroscopy. Pyridine oligomers were investigated in the C-H asymmetric vibration region (2980-3100 cm-1) using this experimental technique. The number of molecules for the clusters responsibles for each band were determined by means of pick-up curves as well as mass sensitive depletion spectra. Furthermore, the intensity dependence of the different bands on applying a dc electric field was studied. The assignment of the different structures for pyridine clusters on the basis of these measurements were also carried out. S. Crawford et al., Angew. Chem. Int. Ed., 48, 755 (2009).

  13. Functionally graded materials

    CERN Document Server

    Mahamood, Rasheedat Modupe

    2017-01-01

    This book presents the concept of functionally graded materials as well as their use and different fabrication processes. The authors describe the use of additive manufacturing technology for the production of very complex parts directly from the three dimension computer aided design of the part by adding material layer after layer. A case study is also presented in the book on the experimental analysis of functionally graded material using laser metal deposition process.

  14. Stabilized fiber-reinforced pavement base course with recycled aggregate

    Science.gov (United States)

    Sobhan, Khaled

    's assumptions for rigid pavements), which has been found to explain reasonably well the field behavior of unreinforced and fiber-reinforced concrete slabs on grade. Finally, a preliminary cost analysis demonstrated that the use of stabilized recycled aggregate instead of a standard crushed stone base course can result in a meaningful economic savings.

  15. Byproduct aggregate. Copper slag aggregate, ferronickel slag aggregate; Fukusan kotsuzai. Do suragu kotsuzai, fuero nikkeru suragu kotsuzai

    Energy Technology Data Exchange (ETDEWEB)

    Kajiwara, Toshitaka

    1998-08-10

    Copper slag aggregate and ferronickel slag aggregate has not only usual substitute of sand or crushed sand but many features unlike sand or unlike crushed sand. It has many features unlike sand or crushed sand. It seems that especially, behavior of the particulates minute is features of deserving in addition, the examination in future. Of course, one feature also consists on the merit on the demerit by the use. And, copper slag aggregate, ferronickel slag aggregate have also limited the production place at the output of about 2 million annual production tons. These features are utilized, and in addition, wants to teach and want to receive the wider usage. (NEDO)

  16. Natural aggregates of the conterminous United States

    Science.gov (United States)

    Langer, William H.

    1988-01-01

    Crushed stone and sand and gravel are the two main sources of natural aggregates. These materials are commonly used construction materials and frequently can be interchanged with one another. They are widely used throughout the United States, with every State except two producing crushed stone. Together they amount to about half the mining volume in the United States. Approximately 96 percent of sand and gravel and 77 percent of the crushed stone produced in the United States are used in the construction industry. Natural aggregates are widely distributed throughout the United States in a variety of geologic environments. Sand and gravel deposits commonly are the results of the weathering of bedrock and subsequent transportation and deposition of the material by water or ice (glaciers). As such, they commonly occur as river or stream deposits or in glaciated areas as glaciofluvial and other deposits. Crushed stone aggregates are derived from a wide variety of parent bedrock materials. Limestone and other carbonates account for approximately three quarters of the rocks used for crushed stone, with granite and other igneous rocks making up the bulk of the remainder. Limestone deposits are widespread throughout the Central and Eastern United States and are scattered in the West. Granites are widely distributed in the Eastern and Western United States, with few exposures in the Midwest. Igneous rocks (excluding granites) are largely concentrated in the Western United States and in a few isolated localities in the East. Even though natural aggregates are widely distributed throughout the United States, they are not universally available for consumptive use. Some areas are devoid of sand and gravel, and potential sources of crushed stone may be covered with sufficient unconsolidated material to make surface mining impractical. In some areas many aggregates do not meet the physical property requirements for certain uses, or they may contain mineral constituents that react

  17. OpenER, a Dutch Initiative in Open Educational Resources

    Science.gov (United States)

    Schuwer, Robert; Mulder, Fred

    2009-01-01

    Over the period 2006-2008, the Dutch Open Universiteit Nederland conducted an experiment in which Open Educational Resources (OER) were offered in an effort to bridge the gap between informal and formal learning and to establish a new style of entry portal to higher education with no barriers at all. OpenER received considerable attention both in…

  18. Don’t hate the aggregator. Become the aggregator

    Directory of Open Access Journals (Sweden)

    Maria Chiara Pievatolo

    2012-10-01

    Full Text Available Il 25 ottobre 2012 ho partecipato a una conferenza sull’Open Access con Jean-Claude Guédon, organizzata da SardegnaRicerche. Le criticità degli oligopoli dell’editoria scientifica sono già evidenti, all’estero. In Italia però, complice una valutazione della ricerca costruita su database parziali, proprietari...

  19. Lightweight Aggregate Concrete. The materials in the precast elements

    DEFF Research Database (Denmark)

    Goltermann, Per; Larsen, Henning; Ingholt, N.U.

    1996-01-01

    The precast lightweight aggregate concrete (LAC) elements are used extensively in Denmark, where the use of precast elements domonates the building structures. Similar elements are used in other parts of Nothern Europe, which have lead to development of an European standard for precast LAC elements...... of LAC with open structure (prEN1520).The test results have shown that the formulas in prEN1520's revision are fairly correct and lead to slightly conservative estimates of the modulus of elasticity and flexural strength....

  20. Cloud Aggregation and Bursting for Object Based Sharable Environment

    Directory of Open Access Journals (Sweden)

    Mr. Pradeep Kumar Tripathi

    2011-09-01

    Full Text Available Cloud computing promises innate scalability and high availability at low cost. So far cloud storage deployments were subject to big companies but an increasing amount of available open-source systems allow also smaller private cloud installations. In this paper we discuss cloud aggregation and cloud bursting with their empirical review. Based on the review we map class and object in the sharable small clouds for making clouds more efficient. We also consider some of the security concern for the cloud computing for authorized data sharing between clouds.

  1. Role of multicellular aggregates in biofilm formation

    DEFF Research Database (Denmark)

    Kragh, Kasper N.; Hutchison, Jaime B.; Melaugh, Gavin

    2016-01-01

    In traditional models of in vitro biofilm development, individual bacterial cells seed a surface, multiply, and mature into multicellular, three-dimensional structures. Much research has been devoted to elucidating the mechanisms governing the initial attachment of single cells to surfaces. However......, in natural environments and during infection, bacterial cells tend to clump as multicellular aggregates, and biofilms can also slough off aggregates as a part of the dispersal process. This makes it likely that biofilms are often seeded by aggregates and single cells, yet how these aggregates impact biofilm...... initiation and development is not known. Here we use a combination of experimental and computational approaches to determine the relative fitness of single cells and preformed aggregates during early development of Pseudomonas aeruginosa biofilms. We find that the relative fitness of aggregates depends...

  2. Waves and aggregation patterns in myxobacteria

    Science.gov (United States)

    Igoshin, Oleg A.; Welch, Roy; Kaiser, Dale; Oster, George

    2004-03-01

    Under starvation conditions, a population of myxobacteria aggregates to build a fruiting body whose shape is species-specific and within which the cells sporulate. Early in this process, cells often pass through a "ripple phase" characterized by traveling linear, concentric, and spiral waves. These waves are different from the waves observed during slime mold aggregation that depend on diffusible morphogens, because myxobacteria communicate by direct contact. The difference is most dramatic when waves collide: rather than annihilating one another, myxobacterial waves appear to pass through one another unchanged. Under certain conditions, the spacing and location of the nascent fruiting bodies is determined by the wavelength and pattern of the waves. Later in fruiting body development, waves are replaced by streams of cells that circulate around small initial aggregates enlarging and rounding them. Still later, pairs of motile aggregates coalesce to form larger aggregates that develop into fruiting bodies. Here we present a mathematical model that quantitatively explains these wave and aggregation phenomena.

  3. A vertically resolved model for phytoplankton aggregation

    Indian Academy of Sciences (India)

    Iris Kriest; Geoffrey T Evans

    2000-12-01

    This work presents models of the vertical distribution and flux of phytoplankton aggregates, including changes with time in the distribution of aggregate sizes and sinking speeds. The distribution of sizes is described by two parameters, the mass and number of aggregates, which greatly reduces the computational cost of the models. Simple experiments demonstrate the effects of aggregation on the timing and depth distribution of primary production and export. A more detailed ecological model is applied to sites in the Arabian Sea; it demonstrates that aggregation can be important for deep sedimentation even when its effect on surface concentrations is small, and it presents the difference in timing between settlement of aggregates and fecal pellets.

  4. Compression Dispersion Efficiency of Recycled Aggregate Concrete Struts At Different Load Concentration Ratios

    Directory of Open Access Journals (Sweden)

    Dr. Rakesh Kumar, Dr.P.K Mehta,Devbrat Singh, Anup Kumar Pandey, Sarvesh Kumar

    2014-06-01

    Full Text Available Infrastructure development activities in India have increased many folds in recent times. This has resulted in increase in the demand of construction materials like cement, coarse aggregate, fine aggregate etc. Huge quantities of concrete wastes are produced due to demolition of old structures. If recycled aggregate from this waste is used for construction purpose, it will not only make the structures economical and eco-friendly butwill also solve the problem of waste disposal.Recycling old waste concrete by crushing and grading into coarse aggregates for use in new structural concrete is drawing the attention of engineers, environmentalists and researchers since last three decades. In this paper, an attempt has been made to study the compression dispersion behaviour of struts of natural coarse aggregate (NCA and recycle coarse aggregate (RCA at different load concentration ratio and aspect ratio. For the study, struts of 450 mm height and 75mm thickness with varying widths starting from 75mm to 450mm, using NCA and RCA concrete, were cast. The testing of struts was carriedout on loading frame of capacity 500 kN. The struts were tested to failure under in-plane compressive load applied through symmetrically placed steel plate (75×75×10 mm at top andbottom of the struts.

  5. Aggregates in the Temporal Query Language TQuel,

    Science.gov (United States)

    1987-07-27

    makes it possible to define both standard and unique aggregates in a rigorous way. Ceri and Gottlob present 43 prVPW t TW WRJR V P P V * a translation...from a subset of SQL that includes aggregates into relational algebra, thereby defining an operational semantics for SQL aggregates [Ceri & Gottlob ...Zvi, J. The Time Relational Model. Ph). Diss. Computer Science Department, UCLA, 1982. (Ceri & Gotlob 19851 Ceri, S. and G. Gottlob . Translating SQL

  6. Rapid aggregation of biofuel-producing algae by the bacterium Bacillus sp. strain RP1137.

    Science.gov (United States)

    Powell, Ryan J; Hill, Russell T

    2013-10-01

    Algal biofuels represent one of the most promising means of sustainably replacing liquid fuels. However, significant challenges remain before alga-based fuels become competitive with fossil fuels. One of the largest challenges is the ability to harvest the algae in an economical and low-energy manner. In this article, we describe the isolation of a bacterial strain, Bacillus sp. strain RP1137, which can rapidly aggregate several algae that are candidates for biofuel production, including a Nannochloropsis sp. This bacterium aggregates algae in a pH-dependent and reversible manner and retains its aggregation ability after paraformaldehyde fixation, opening the possibility for reuse of the cells. The optimal ratio of bacteria to algae is described, as is the robustness of aggregation at different salinities and temperatures. Aggregation is dependent on the presence of calcium or magnesium ions. The efficiency of aggregation of Nannochloropsis oceanica IMET1 is between 70 and 95% and is comparable to that obtained by other means of harvest; however, the rate of harvest is fast, with aggregates forming in 30 s.

  7. An Unprecedented Aggregation of Whale Sharks, Rhincodon typus, in Mexican Coastal Waters of the Caribbean Sea

    Science.gov (United States)

    de la Parra Venegas, Rafael; Hueter, Robert; González Cano, Jaime; Tyminski, John; Gregorio Remolina, José; Maslanka, Mike; Ormos, Andrea; Weigt, Lee; Carlson, Bruce; Dove, Alistair

    2011-01-01

    Whale sharks, Rhincodon typus, are often perceived as solitary behemoths that live and feed in the open ocean. To the contrary, evidence is accumulating that they are gregarious and form seasonal aggregations in some coastal waters. One such aggregation occurs annually north of Cabo Catoche, off Isla Holbox on the Yucatán Peninsula of Mexico. Here we report a second, much denser aggregation of whale sharks (dubbed “the Afuera”) that occurs east of the tip of the Yucatán Peninsula in the Caribbean Sea. The 2009 Afuera event comprised the largest aggregation of whale sharks ever reported, with up to 420 whale sharks observed in a single aerial survey, all gathered in an elliptical patch of ocean approximately 18 km2. Plankton studies indicated that the sharks were feeding on dense homogenous patches of fish eggs, which DNA barcoding analysis identified as belonging to little tunny, Euthynnus alletteratus. This contrasts with the annual Cabo Catoche aggregation nearby, where prey consists mostly of copepods and sergestid shrimp. Increased sightings at the Afuera coincide with decreased sightings at Cabo Catoche, and both groups have the same sex ratio, implying that the same animals are likely involved in both aggregations; tagging data support this idea. With two whale shark aggregation areas, high coastal productivity and a previously-unknown scombrid spawning ground, the northeastern Yucatán marine region is a critical habitat that deserves more concerted conservation efforts. PMID:21559508

  8. An Approach to Reconciling Competing Ethical Principles in Aggregating Heterogeneous Health Preferences.

    Science.gov (United States)

    Dewitt, Barry; Davis, Alexander; Fischhoff, Baruch; Hanmer, Janel

    2017-08-01

    Health-related quality of life (HRQL) scores are used extensively to quantify the effectiveness of medical interventions. Societal preference-based HRQL scores aim to produce societal valuations of health by aggregating valuations from individuals in the general population, where each aggregation procedure embodies different ethical principles, as explained in social choice theory. Using the Health Utilities Index as an exemplar, we evaluate societal preference-based HRQL measures in the social choice theory framework. We find that current preference aggregation procedures are typically justified in terms of social choice theory. However, by convention, they use only one of many possible aggregation procedures (the mean). Central to the choice of aggregation procedure is how to treat preference heterogeneity, which can affect analyses that rely on HRQL scores, such as cost-effectiveness analyses. We propose an analytical-deliberative framework for choosing one (or a set of) aggregation procedure(s) in a socially credible way, which we believe to be analytically sound and empirically tractable, but leave open the institutional mechanism needed to implement it. Socially acceptable decisions about aggregating heterogeneous preferences require eliciting stakeholders' preferences among the set of analytically sound procedures, representing different ethical principles. We describe a framework for eliciting such preferences for the creation of HRQL scores, informed by social choice theory and behavioral decision research.

  9. Population balance modeling of antibodies aggregation kinetics.

    Science.gov (United States)

    Arosio, Paolo; Rima, Simonetta; Lattuada, Marco; Morbidelli, Massimo

    2012-06-21

    The aggregates morphology and the aggregation kinetics of a model monoclonal antibody under acidic conditions have been investigated. Growth occurs via irreversible cluster-cluster coagulation forming compact, fractal aggregates with fractal dimension of 2.6. We measured the time evolution of the average radius of gyration, , and the average hydrodynamic radius, , by in situ light scattering, and simulated the aggregation kinetics by a modified Smoluchowski's population balance equations. The analysis indicates that aggregation does not occur under diffusive control, and allows quantification of effective intermolecular interactions, expressed in terms of the Fuchs stability ratio (W). In particular, by introducing a dimensionless time weighed on W, the time evolutions of measured under various operating conditions (temperature, pH, type and concentration of salt) collapse on a single master curve. The analysis applies also to data reported in the literature when growth by cluster-cluster coagulation dominates, showing a certain level of generality in the antibodies aggregation behavior. The quantification of the stability ratio gives important physical insights into the process, including the Arrhenius dependence of the aggregation rate constant and the relationship between monomer-monomer and cluster-cluster interactions. Particularly, it is found that the reactivity of non-native monomers is larger than that of non-native aggregates, likely due to the reduction of the number of available hydrophobic patches during aggregation.

  10. Pre-aggregation for Probability Distributions

    DEFF Research Database (Denmark)

    Timko, Igor; Dyreson, Curtis E.; Pedersen, Torben Bach

    Motivated by the increasing need to analyze complex uncertain multidimensional data (e.g., in order to optimize and personalize location-based services), this paper proposes novel types of {\\em probabilistic} OLAP queries that operate on aggregate values that are probability distributions...... and the techniques to process these queries. The paper also presents the methods for computing the probability distributions, which enables pre-aggregation, and for using the pre-aggregated distributions for further aggregation. In order to achieve good time and space efficiency, the methods perform approximate...... multidimensional data analysis that is considered in this paper (i.e., approximate processing of probabilistic OLAP queries over probability distributions)....

  11. Aggregate growth in a protoplanetary disk

    Science.gov (United States)

    Xiang, Chuchu; Carballido, Augusto; Matthews, Lorin; Hyde, Truell

    2017-01-01

    We present a method to model the growth of neutral and charged dusts in a turbulent protoplanetary disk, and analyze their collision probabilities. Coagulation of dust aggregates plays an important role in the formation of planets and is of key importance to the evolution of protoplanetary disks. In our method, the temporal evolution of the dusts is followed by Monte Carlo algorithm, and the inter-particle interactions are calculated by Aggregate_Builder (AB), which is a code used to model the collision process of aggregates. First an aggregate library is built and all the aggregates are binned according to their sizes. In each iteration, the collision rate for aggregates from any two bins are computed, which determines the time it takes for the next collision to happen and which two aggregates are selected for collision. Then the AB codes are used to calculate the interaction of the two aggregates. The relative velocity between the two aggregates is the vector sum of Brownian velocity and the turbulent velocity. The latter is calculated by ATHENA, which is a grid-based code for astrophysical magnetohydrodynamics. In each iteration, it’s determined whether the two aggregates hit or miss. In the case of hit, it either sticks or bounces as determined by the critical velocity. As a result, the neutral aggregates are more porous than the charged ones. For a certain size of incoming aggregates, the neutral ones have a higher collision probability than the charged ones. Also, similarly-sized aggregates have lower collision probabilities than aggregates with large size dispersions. This research enables us to determine which physical properties have a greater impact on the collision rate. By tracing the dust size distribution, we can identify the stage when they settle out to the mid-plane and how long it takes to develop to that stage. In the hit-stick regime, our results are consistent with the experiments which shows that when the velocity is smaller than the

  12. Aggregated Dynamic Dataflow Graph Generation and Visualization

    Directory of Open Access Journals (Sweden)

    I. Szabó

    2013-12-01

    Full Text Available Aggregated Dynamic Dataflow Graphs can assist programmers to uncover the main data paths of a given algorithm. This information can be useful when scaling a singlethreaded program into a multi-core architecture. The amount of data movements is crucial when targeting for cache incoherent and/or heterogeneous platforms. This paper presents two methods for generating function-level Aggregated Dynamic Dataflow Graphs. Instruction level trace log was used as a basis, which was generated by Microsoft Giano processor simulator platform. Top-down aggregation strategy and relational database was used to speed up the generation of different views of the aggregated dataflow and call graphs.

  13. Macroeconomic susceptibility, inflation, and aggregate supply

    Science.gov (United States)

    Hawkins, Raymond J.

    2017-03-01

    We unify aggregate-supply dynamics as a time-dependent susceptibility-mediated relationship between inflation and aggregate economic output. In addition to representing well various observations of inflation-output dynamics this parsimonious formalism provides a straightforward derivation of popular representations of aggregate-supply dynamics and a natural basis for economic-agent expectations as an element of inflation formation. Our formalism also illuminates questions of causality and time-correlation that challenge central banks for whom aggregate-supply dynamics is a key constraint in their goal of achieving macroeconomic stability.

  14. Pre-aggregation for Probability Distributions

    DEFF Research Database (Denmark)

    Timko, Igor; Dyreson, Curtis E.; Pedersen, Torben Bach

    Motivated by the increasing need to analyze complex uncertain multidimensional data (e.g., in order to optimize and personalize location-based services), this paper proposes novel types of {\\em probabilistic} OLAP queries that operate on aggregate values that are probability distributions...... and the techniques to process these queries. The paper also presents the methods for computing the probability distributions, which enables pre-aggregation, and for using the pre-aggregated distributions for further aggregation. In order to achieve good time and space efficiency, the methods perform approximate...... multidimensional data analysis that is considered in this paper (i.e., approximate processing of probabilistic OLAP queries over probability distributions)....

  15. Openness initiative

    Energy Technology Data Exchange (ETDEWEB)

    Duncan, S.S. [Los Alamos National Lab., NM (United States)

    1995-12-31

    Although antinuclear campaigns seem to be effective, public communication and education efforts on low-level radioactive waste have mixed results. Attempts at public information programs on low-level radioactive waste still focus on influencing public opinion. A question then is: {open_quotes}Is it preferable to have a program focus on public education that will empower individuals to make informed decisions rather than trying to influence them in their decisions?{close_quotes} To address this question, a case study with both quantitative and qualitative data will be used. The Ohio Low-Level Radioactive Waste Education Program has a goal to provide people with information they want/need to make their own decisions. The program initiated its efforts by conducting a statewide survey to determine information needed by people and where they turned for that information. This presentation reports data from the survey and then explores the program development process in which programs were designed and presented using the information. Pre and post data from the programs reveal attitude and knowledge shifts.

  16. Morphological classification of nanoceramic aggregates

    Science.gov (United States)

    Crosta, Giovanni F.; Kang, Bongwoo; Ospina, Carolina; Sung, Changmo

    2005-01-01

    Aluminum silicate nanoaggregates grown at near-room temperature on an organic template under a variety of experimental conditions have been imaged by transmission electron microscopy. Images have been automatically classified by an algorithm based on "spectrum enhancement", multivariate statistics and supervised optimization. Spectrum enhancement consists of subtracting, in the log scale, a known function of wavenumber from the angle averaged power spectral density of the image. Enhanced spectra of each image, after polynomial interpolation, have been regarded as morphological descriptors and as such submitted to principal components analysis nested with a multiobjective parameter optimization algorithm. The latter has maximized pairwise discrimination between classes of materials. The role of the organic template and of a reaction parameter on aggregate morphology has been assessed at two magnification scales. Classification results have also been related to crystal structure data derived from selected area electron diffraction patterns.

  17. Collisional Aggregation due to Turbulence

    CERN Document Server

    Pumir, Alain

    2015-01-01

    Collisions between particles suspended in a fluid play an important role in many physical processes. As an example, collisions of microscopic water droplets in clouds are a necessary step in the production of macroscopic raindrops. Collisions of dust grains are also conjectured to be important for planet formation in the gas surrounding young stars, and also to play a role in the dynamics of sand storms. In these processes, collisions are favoured by fast turbulent motions. Here we review recent advances in the understanding of collisional aggregation due to turbulence. We discuss the role of fractal clustering of particles, and caustic singularities of their velocities. We also discuss limitations of the Smoluchowski equation for modelling these processes. These advances lead to a semi-quantitative understanding on the influence of turbulence on collision rates, and point to deficiencies in the current understanding of rainfall and planet formation.

  18. Colloid Release from Soil Aggregates

    DEFF Research Database (Denmark)

    Vendelboe, Anders Lindblad; Møldrup, Per; Schjønning, Per;

    2012-01-01

    The content of water-dispersible colloids (WDC) has a major impact on soil functions and structural stability. In addition, the presence of mobile colloids may increase the risk of colloid-facilitated transport of strongly sorbing environmental contaminants. The WDC content was measured in 39 soils......, using laser diffraction, by agitating the samples using a wet-dispersion unit. This approach eliminated the need for long sedimentation times required by the more classical end-over-end shaking approach and provided information about the time-dependent release of WDC. The total clay content of the soils...... ranged from 0.1 to 0.44 kg kg−1. The WDC content was measured on air-dry and moist 1- to 2-mm aggregates. The WDC content at a reference time was highly correlated to the total clay content (r > 0.91, P soils. Only for two sites was the WDC content correlated to the content of clay...

  19. Contemporary Gleason grading and novel Grade Groups in clinical practice.

    Science.gov (United States)

    Magi-Galluzzi, Cristina; Montironi, Rodolfo; Epstein, Jonathan I

    2016-09-01

    The Gleason grading system provides important information for guiding prostate cancer patients' management and prognostication. The grading system underwent significant modifications over the past decade. In 2005 and more recently in 2014, the International Society of Urological Pathology (ISUP) held two consensus conferences to update prostate cancer grading. Recently, five prognostic grade groups have been proposed to be used in parallel to the Gleason grading system. The purpose of this review is to highlight the key changes in the Gleason grading system and the utility of the grade groups to better reflect biologic behavior for both patients and clinicians. At the 2014 ISUP consensus conference, prostate cancer Gleason grading was updated and a previously proposed concept of five prognostic grade groups, from 1 to 5 was supported. The Grade Groups, used in parallel to the modified Gleason grading system, translate Gleason scores in five distinct risk categories where Grade Group 1 is defined as Gleason score 6 or less, Grade Group 2 as Gleason score 3 + 4 = 7, Grade Group 3 as Gleason score 4 + 3 = 7, Grade Group 4 as Gleason score 4 + 4 = 8, and Grade Group 5 as Gleason score 9/10. This 5-tiered grade group system better reflects biologic behavior and guides clinical care. The Grade Groups have been endorsed by the ISUP and the World Health Organization. The performance of the Grade Groups has been examined in several recent studies. This review summarizes developments over the last year in the use of grade groups and outlines their value in clinical practice.

  20. Gallbladder removal - open

    Science.gov (United States)

    Cholecystectomy - open; Surgery - gallbladder - open ... a medical instrument called a laparoscope ( laparoscopic cholecystectomy ). Open gallbladder surgery is used when laparoscopic surgery cannot ...

  1. Graded-index magnonics

    Science.gov (United States)

    Davies, C. S.; Kruglyak, V. V.

    2015-10-01

    The wave solutions of the Landau-Lifshitz equation (spin waves) are characterized by some of the most complex and peculiar dispersion relations among all waves. For example, the spin-wave ("magnonic") dispersion can range from the parabolic law (typical for a quantum-mechanical electron) at short wavelengths to the nonanalytical linear type (typical for light and acoustic phonons) at long wavelengths. Moreover, the long-wavelength magnonic dispersion has a gap and is inherently anisotropic, being naturally negative for a range of relative orientations between the effective field and the spin-wave wave vector. Nonuniformities in the effective field and magnetization configurations enable the guiding and steering of spin waves in a deliberate manner and therefore represent landscapes of graded refractive index (graded magnonic index). By analogy to the fields of graded-index photonics and transformation optics, the studies of spin waves in graded magnonic landscapes can be united under the umbrella of the graded-index magnonics theme and are reviewed here with focus on the challenges and opportunities ahead of this exciting research direction.

  2. Serving Grades Over the Internet.

    Science.gov (United States)

    Harris, James K.

    This paper demonstrates a grade server that allows college students to access their grades over the Internet from the instructor's home page. Using a CGI (common gateway interface) program written in Visual Basic, the grades are read directly from an Excel spreadsheet and presented to the requester after he/she enters a password. The grade for…

  3. Thrombolytic therapy reduces red blood cell aggregation in plasma without affecting intrinsic aggregability.

    Science.gov (United States)

    Ben-Ami, R; Sheinman, G; Yedgar, S; Eldor, A; Roth, A; Berliner, A S; Barshtein, G

    2002-03-15

    Red blood cell (RBC) aggregation may contribute to occlusion of the coronary microcirculation during myocardial infarction. We studied the effect of thrombolytic therapy on RBC aggregation in patients with acute myocardial infarction (AMI). Compared with patients with myocardial infarction who did not receive thrombolytic therapy, those treated with systemic thrombolysis exhibited significantly reduced RBC aggregation, reduced plasma fibrinogen levels and increased plasma D-dimer levels. Using measurement of RBC aggregation in a standardized dextran-500 solution, reduction in RBC aggregation after thrombolysis was shown to be plasma dependent. Thrombolytic therapy had no direct effect on intrinsic RBC aggregability in patients with AMI. We conclude that thrombolytic therapy has rheologic consequences that may contribute to its overall efficacy. Inhibition of RBC aggregation by thrombolytic therapy may result from the degradation of fibrinogen, a key factor in the formation of RBC aggregates, and from the generation of fibrinogen degradation products capable of disaggregating RBCs.

  4. Mobility and Heterogeneity Aware Cluster-Based Data Aggregation for Wireless Sensor Network

    DEFF Research Database (Denmark)

    Dnyaneshwar, Mantri; Prasad, Neeli R.; Prasad, Ramjee

    2016-01-01

    Internet of things (IoT) is the modern era, which offers a variety of novel applications for mobile targets and opens the new domains for the distributed data aggregations using Wireless Sensor Networks (WSNs). However, low cost tiny sensors used for network formation generate the large amount...

  5. In-plane Shear Joint Capacity of Pracast Lightweight Aggregate Concrete Elements

    DEFF Research Database (Denmark)

    Larsen, Henning; Goltermann, Per; Scherfig, Søren;

    1996-01-01

    The paper establishes and documents formulas for the in-plane shear capacity between precast elements of lightweight aggregate concrete with open structure. The joints investigated are rough or toothed and have all been precracked prior to the testing in order to obtain realistic test results...

  6. Opening Address

    Science.gov (United States)

    Crovini, L.

    1994-01-01

    Ladies and Gentlemen To quote Mr Jean Terrien: "Physics must be one step ahead of metrology". A long-serving Director of the BIPM, he said these words when visiting the IMGC in 1970 as a member of the scientific board of our Institute. At that time it was still an open question whether the IMGC should start research work on the absolute measurement of silicon lattice spacing. Mr Terrien underlined the revolutionary character of x-ray interferometry and, eventually, he caused the balance needle to lean towards the ... right direction. Mr Terrien correctly foresaw that, like Michelson's interferometer of 1880, x-ray interferometry could have a prominent place in today's science and technology. And while, in the first case, after more than a century we can see instruments based on electromagnetic wave interaction within every one's reach in laboratories and, sometimes, in workshops, in the second case, twenty-five years since the first development of an x-ray interferometer we can witness its role in nanometrology. Today and tomorrow we meet to discuss how to go beyond the sixth decimal place in the value of the Avogadro constant. We are aware that the quest for this achievement requires the cooperation of scientists with complementary capabilities. I am sure that the present workshop is a very good opportunity to present and discuss results and to improve and extend existing cooperation. The new adjustment of fundamental constants envisaged by the CODATA Task Group is redoubling scientists' efforts to produce competitive values of NA. The results of the measurements of the silicon lattice spacing in terms of an optical wavelength, which were available for the 1986 adjustment, combined with the determination of silicon molar volume, demonstrate how such an NA determination produces a consistent set of other constants and opens the way to a possible redefinition of the kilogram. We shall see in these two days how far we have progressed along this road. For us at the

  7. Opening Mathematics Texts: Resisting the Seduction

    Science.gov (United States)

    Wagner, David

    2012-01-01

    This analysis of the writing in a grade 7 mathematics textbook distinguishes between closed texts and open texts, which acknowledge multiple possibilities. I use tools that have recently been applied in mathematics contexts, focussing on grammatical features that include personal pronouns, modality, and types of imperatives, as well as on…

  8. Preformed Seeds Modulate Native Insulin Aggregation Kinetics.

    Science.gov (United States)

    Dutta, Colina; Yang, Mu; Long, Fei; Shahbazian-Yassar, Reza; Tiwari, Ashutosh

    2015-12-10

    Insulin aggregates under storage conditions via disulfide interchange reaction. It is also known to form aggregates at the site of repeated injections in diabetes patients, leading to injection amyloidosis. This has fueled research in pharmaceutical and biotechnology industry as well as in academia to understand factors that modulate insulin stability and aggregation. The main aim of this study is to understand the factors that modulate aggregation propensity of insulin under conditions close to physiological and measure effect of "seeds" on aggregation kinetics. We explored the aggregation kinetics of insulin at pH 7.2 and 37 °C in the presence of disulfide-reducing agent dithiothreitol (DTT), using spectroscopy (UV-visible, fluorescence, and Fourier transform infrared spectroscopy) and microscopy (scanning electron microscopy, atomic force microscopy) techniques. We prepared insulin "seeds" by incubating disulfide-reduced insulin at pH 7.2 and 37 °C for varying lengths of time (10 min to 12 h). These seeds were added to the native protein and nucleation-dependent aggregation kinetics was measured. Aggregation kinetics was fastest in the presence of 10 min seeds suggesting they were nascent. Interestingly, intermediate seeds (30 min to 4 h incubation) resulted in formation of transient fibrils in 4 h that converted to amorphous aggregates upon longer incubation of 24 h. Overall, the results show that insulin under disulfide reducing conditions at pH and temperature close to physiological favors amorphous aggregate formation and seed "maturity" plays an important role in nucleation dependent aggregation kinetics.

  9. Open life science research, open software and the open century

    Institute of Scientific and Technical Information of China (English)

    Youhua Chen

    2015-01-01

    At the age of knowledge explosion and mass scientific information, I highlighted the importance of conducting open science in life and medical researches through the extensive usage of open software and documents. The proposal of conducting open science is to reduce the limited repeatability of researches in life science. I outlined the essential steps for conducting open life science and the necessary standards for creating, reusing and reproducing open materials. Different Creative Commons licenses were presented and compared of their usage scope and restriction. As a conclusion, I argued that open materials should be widely adopted in doing life and medical researches.

  10. An in-situ Observation on Initial Aggregation Process of Colloidal Particles near Three-Phase Contact Line of Air, Water and Vertical Substrate

    Institute of Scientific and Technical Information of China (English)

    YAO Can; WANG Yu-Ren; LAN Ding; DUAN Li; KANG Qi

    2008-01-01

    The self-assembling process near the three-phase contact line of air, water and vertical substrate is widely used to produce various kinds of nanostructured materials and devices. We perform an in-situ observation on the selfassembling process in the vicinity of the three phase contact line. Three kinds of aggregations, i.e. particle-particle aggregation, particle-chain aggregation and chain-chain aggregation, in the initial stage of vertical deposition process are revealed by our experiments. It is found that the particle-particle aggregation and the particle-chain aggregation can be qualitatively explained by the theory of the capillary immersion force and mirror image force,while the chain-chain aggregation leaves an opening question for the further studies. The present study may provide more deep insight into the self-assembling process of colloidal particles.

  11. Assessment of the contaminants level in recycled aggregates and alternative new technologies for contaminants recognition and removal

    NARCIS (Netherlands)

    Lotfi, S.; Di Maio, F.; Xia, H.; Serranti, S.; Palmieri, R.; Bonifazi, G.

    2015-01-01

    One of the main challenging problems associated with the use of Recycled Aggregates (RA) is the level of mixed contaminants. For utilizing RA in high-grade applications, it is essential to monitor and minimise the content of the pollutants. To this extent the C2CA concrete recycling process

  12. Assessment of the contaminants level in recycled aggregates and alternative new technologies for contaminants recognition and removal

    NARCIS (Netherlands)

    Lotfi, S.; Di Maio, F.; Xia, H.; Serranti, S.; Palmieri, R.; Bonifazi, G.

    2015-01-01

    One of the main challenging problems associated with the use of Recycled Aggregates (RA) is the level of mixed contaminants. For utilizing RA in high-grade applications, it is essential to monitor and minimise the content of the pollutants. To this extent the C2CA concrete recycling process investig

  13. Assessment of the contaminants level in recycled aggregates and alternative new technologies for contaminants recognition and removal

    NARCIS (Netherlands)

    Lotfi, S.; Di Maio, F.; Xia, H.; Serranti, S.; Palmieri, R.; Bonifazi, G.

    2015-01-01

    One of the main challenging problems associated with the use of Recycled Aggregates (RA) is the level of mixed contaminants. For utilizing RA in high-grade applications, it is essential to monitor and minimise the content of the pollutants. To this extent the C2CA concrete recycling process investig

  14. Cut-off Grade Optimization for Maximizing the Output Rate

    Directory of Open Access Journals (Sweden)

    A. Khodayari

    2012-12-01

    Full Text Available In the open-pit mining, one of the first decisions that must be made in production planning stage, after completing the design of final pit limits, is determining of the processing plant cut-off grade. Since this grade has an essential effect on operations, choosing the optimum cut-off grade is of considerable importance. Different goals may be used for determining optimum cut-off grade. One of these goals may be maximizing the output rate (amount of product per year, which is very important, especially from marketing and market share points of view. Objective of this research is determining the optimum cut-off grade of processing plant in order to maximize output rate. For performing this optimization, an Operations Research (OR model has been developed. The object function of this model is output rate that must be maximized. This model has two operational constraints namely mining and processing restrictions. For solving the model a heuristic method has been developed. Results of research show that the optimum cut-off grade for satisfying pre-stated goal is the balancing grade of mining and processing operations, and maximum production rate is a function of the maximum capacity of processing plant and average grade of ore that according to the above optimum cut-off grade must be sent to the plant.

  15. Impact of Particle Aggregation on Nanoparticle Reactivity

    Science.gov (United States)

    Jassby, David

    2011-12-01

    The prevalence of nanoparticles in the environment is expected to grow in the coming years due to their increasing pervasiveness in consumer and industrial applications. Once released into the environment, nanoparticles encounter conditions of pH, salinity, UV light, and other solution conditions that may alter their surface characteristics and lead to aggregation. The unique properties that make nanoparticles desirable are a direct consequence of their size and increased surface area. Therefore, it is critical to recognize how aggregation alters the reactive properties of nanomaterials, if we wish to understand how these properties are going to behave once released into the environment. The size and structure of nanoparticle aggregates depend on surrounding conditions, including hydrodynamic ones. Depending on these conditions, aggregates can be large or small, tightly packed or loosely bound. Characterizing and measuring these changes to aggregate morphology is important to understanding the impact of aggregation on nanoparticle reactive properties. Examples of decreased reactivity due to aggregation include the case where tightly packed aggregates have fewer available surface sites compared to loosely packed ones; also, photocatalytic particles embedded in the center of large aggregates will experience less light when compared to particles embedded in small aggregates. However, aggregation also results in an increase in solid-solid interfaces between nanoparticles. This can result in increased energy transfer between neighboring particles, surface passivation, and altered surface tension. These phenomena can lead to an increase in reactivity. The goal of this thesis is to examine the impacts of aggregation on the reactivity of a select group of nanomaterials. Additionally, we examined how aggregation impacts the removal efficiency of fullerene nanoparticles using membrane filtration. The materials we selected to study include ZnS---a metal chalcogenide

  16. Methods of graded rings

    CERN Document Server

    Nastasescu, Constantin

    2004-01-01

    The topic of this book, graded algebra, has developed in the past decade to a vast subject with new applications in noncommutative geometry and physics. Classical aspects relating to group actions and gradings have been complemented by new insights stemming from Hopf algebra theory. Old and new methods are presented in full detail and in a self-contained way. Graduate students as well as researchers in algebra, geometry, will find in this book a useful toolbox. Exercises, with hints for solution, provide a direct link to recent research publications. The book is suitable for courses on Master level or textbook for seminars.

  17. Mechanical evaluation of asphalt-aggregate mixtures prepared with fly ash as a filler replacement

    Energy Technology Data Exchange (ETDEWEB)

    Tapkin, T. [Anadolu Univ., Eskisehir (Turkey). Dept. of Civil Engineering

    2008-01-15

    This paper examined methods of introducing fly ash waste products as a filler in asphalt concrete mixtures. A literature review of studies involving fly ash and asphalts was conducted. The effect of fly ash filler replacements on the mechanical properties of asphalt-aggregate mixtures was investigated. A dense bituminous calcareous aggregate was used as a reference mixture for a series of tests. Three types of fly ash were investigated, notably (1) portland cement; (2) lime; and (3) control specimens. Changes in elastic strain, elastic modulus, and permanent strain properties of the asphalt mixtures were determined through a series of fatigue tests. The behaviour of the asphalt concrete pavements were analyzed under applied loads. Results of the tests showed that the fatigue life of the fly ash specimens was higher than the calcareous aggregate specimens. It was concluded that fly ash can used as a filler replacement for dense-graded wearing courses. 35 refs., 17 tabs., 8 figs.

  18. Protein aggregation and lyophilization: Protein structural descriptors as predictors of aggregation propensity

    OpenAIRE

    Roughton, Brock C.; Iyer, Lavanya K.; Bertelsen, Esben; Topp, Elizabeth M.; Camarda, Kyle V.

    2013-01-01

    Lyophilization can induce aggregation in therapeutic proteins, but the relative importance of protein structure, formulation and processing conditions are poorly understood. To evaluate the contribution of protein structure to lyophilization-induced aggregation, fifteen proteins were co-lyophilized with each of five excipients. Extent of aggregation following lyophilization, measured using size-exclusion chromatography, was correlated with computational and biophysical protein structural desc...

  19. RELATIONSHIPS BETWEEN SOIL MICROBIAL BIOMASS, AGGREGATE STABILITY AND AGGREGATE ASSOCIATED-C: A MECHANISTIC APPROACH

    Directory of Open Access Journals (Sweden)

    Patrizia Guidi

    2014-01-01

    Full Text Available For the identification of C pools involved in soil aggregation, a physically-based aggregate fractionation was proposed, and  additional pretreatments were used in the measurement of the 1-2 mm aggregate stability in order to elucidate the relevance of the role of soil microorganisms with respect to the different aggregate breakdown mechanisms. The study was carried out on three clay loam Regosols, developed on calcareous shales, known history of organic cultivation.Our results showed that the soil C pool controlling the process of stabilisation of aggregates was related to the microbial community. We identified the resistance to fast wetting as the major mechanism of aggregate stability driven by microorganims. The plausible hypothesis is that organic farming promotes fungi growth, improving water repellency of soil aggregates by fungal hydrophobic substances. By contrast, we failed in the identification of C pools controlling the formation of aggregates, probably because of the disturbance of mechanical tillage which contributes to the breakdown of soil aggregates.The physically-based aggregate fractionation proposed in this study resulted useful in the  mechanistically understanding of the role of microorganisms in soil aggregation and it might be suggested for studying the impact of management on C pools, aggregates properties and their relationships in agricultural soils.

  20. Teaching Aggregate Demand and Supply Models

    Science.gov (United States)

    Wells, Graeme

    2010-01-01

    The author analyzes the inflation-targeting model that underlies recent textbook expositions of the aggregate demand-aggregate supply approach used in introductory courses in macroeconomics. He shows how numerical simulations of a model with inflation inertia can be used as a tool to help students understand adjustments in response to demand and…

  1. Comparative evaluation of mineral trioxide aggregate and ...

    African Journals Online (AJOL)

    cannot be achieved if endodontic treatment is needed as a result of dental trauma or ... nanoparticles sized bioceramic BioAggregate (DiaRoot. BioAggregate ... and copious irrigation with 2.5% sodium hypochlorite to maximize cleansing and ...

  2. Familial Aggregation and Childhood Blood Pressure

    NARCIS (Netherlands)

    Wang, Xiaoling; Xu, Xiaojing; Su, Shaoyong; Snieder, Harold

    2015-01-01

    There is growing concern about elevated blood pressure (BP) in children. The evidence for familial aggregation of childhood BP is substantial. Twin studies have shown that a large part of the familial aggregation of childhood BP is due to genes. The first part of this review provides the latest prog

  3. Teaching Aggregate Demand and Supply Models

    Science.gov (United States)

    Wells, Graeme

    2010-01-01

    The author analyzes the inflation-targeting model that underlies recent textbook expositions of the aggregate demand-aggregate supply approach used in introductory courses in macroeconomics. He shows how numerical simulations of a model with inflation inertia can be used as a tool to help students understand adjustments in response to demand and…

  4. A formal approach to aggregated belief formation

    NARCIS (Netherlands)

    Heuvelink, A.; Klein, M.C.A.; Treur, J.

    2008-01-01

    This paper introduces a formal method to aggregate over basic beliefs, in order to deduce aggregated or complex beliefs as often used in applications. Complex beliefs can represent several things, such as a belief about a period in which other beliefs held or the minimal or maximal certainty with wh

  5. BETA-ADRENOBLOCKERS AND PLATELET AGGREGATION. CARVEDILOL

    Directory of Open Access Journals (Sweden)

    A. N. Zakirova

    2008-01-01

    Full Text Available Approaches evolution to studying of beta-blockers influence on platelet aggregation is reviewed. The current view on of beta-blocker antiplatelet effects is presented on the basis of physical and chemical drug properties (water repellency, dipole moment, molecular mass. Trail results on carvedilol influence on platelet aggregation are focused.

  6. Approximation of Aggregate Losses Using Simulation

    Directory of Open Access Journals (Sweden)

    Mohamed A. Mohamed

    2010-01-01

    Full Text Available Problem statement: The modeling of aggregate losses is one of the main objectives in actuarial theory and practice, especially in the process of making important business decisions regarding various aspects of insurance contracts. The aggregate losses over a fixed time period is often modeled by mixing the distributions of loss frequency and severity, whereby the distribution resulted from this approach is called a compound distribution. However, in many cases, realistic probability distributions for loss frequency and severity cannot be combined mathematically to derive the compound distribution of aggregate losses. Approach: This study aimed to approximate the aggregate loss distribution using simulation approach. In particular, the approximation of aggregate losses was based on a compound Poisson-Pareto distribution. The effects of deductible and policy limit on the individual loss as well as the aggregate losses were also investigated. Results: Based on the results, the approximation of compound Poisson-Pareto distribution via simulation approach agreed with the theoretical mean and variance of each of the loss frequency, loss severity and aggregate losses. Conclusion: This study approximated the compound distribution of aggregate losses using simulation approach. The investigation on retained losses and insurance claims allowed an insured or a company to select an insurance contract that fulfills its requirement. In particular, if a company wants to have an additional risk reduction, it can compare alternative policies by considering the worthiness of the additional expected total cost which can be estimated via simulation approach.

  7. Marine particle aggregate breakup in turbulent flows

    Science.gov (United States)

    Rau, Matthew; Ackleson, Steven; Smith, Geoffrey

    2016-11-01

    The dynamics of marine particle aggregate formation and breakup due to turbulence is studied experimentally. Aggregates of clay particles, initially in a quiescent aggregation tank, are subjected to fully developed turbulent pipe flow at Reynolds numbers of up to 25,000. This flow arrangement simulates the exposure of marine aggregates in coastal waters to a sudden turbulent event. Particle size distributions are measured by in-situ sampling of the small-angle forward volume scattering function and the volume concentration of the suspended particulate matter is quantified through light attenuation measurements. Results are compared to measurements conducted under laminar and turbulent flow conditions. At low shear rates, larger sized particles indicate that aggregation initially governs the particle dynamics. Breakup is observed when large aggregates are exposed to the highest levels of shear in the experiment. Models describing the aggregation and breakup rates of marine particles due to turbulence are evaluated with the population balance equation and results from the simulation and experiment are compared. Additional model development will more accurately describe aggregation dynamics for remote sensing applications in turbulent marine environments.

  8. Ratio-Based Gradual Aggregation of Data

    DEFF Research Database (Denmark)

    Iftikhar, Nadeem

    2012-01-01

    cause data management and data storage issues. However, non-flexible and ineffective means of data aggregation not only reduce performance of database queries but also lead to erroneous reporting. This paper presents flexible and effective ratio-based methods for gradual data aggregation in databases...

  9. Oxidation, aggregation and immunogenicity of therapeutic proteins

    NARCIS (Netherlands)

    Torosantucci, Riccardo

    2013-01-01

    The aim of the research described in this thesis is to study the chemical mechanisms responsible for protein aggregation induced by metal catalyzed oxidation and to investigate the relationship between protein oxidation, aggregation and immunogenicity. To this end, recombinant human insulin

  10. Familial Aggregation and Childhood Blood Pressure

    NARCIS (Netherlands)

    Wang, Xiaoling; Xu, Xiaojing; Su, Shaoyong; Snieder, Harold

    There is growing concern about elevated blood pressure (BP) in children. The evidence for familial aggregation of childhood BP is substantial. Twin studies have shown that a large part of the familial aggregation of childhood BP is due to genes. The first part of this review provides the latest

  11. Effects of protein aggregates: an immunologic perspective.

    Science.gov (United States)

    Rosenberg, Amy S

    2006-08-04

    The capacity of protein aggregates to enhance immune responses to the monomeric form of the protein has been known for over a half-century. Despite the clear connection between protein aggregates and antibody mediated adverse events in treatment with early therapeutic protein products such as intravenous immune globulin (IVIG) and human growth hormone, surprisingly little is known about the nature of the aggregate species responsible for such effects. This review focuses on a framework for understanding how aggregate species potentially interact with the immune system to enhance immune responses, garnered from basic immunologic research. Thus, protein antigens presented in a highly arrayed structure, such as might be found in large nondenatured aggregate species, are highly potent in inducing antibody responses even in the absence of T-cell help. Their potency may relate to the ability of multivalent protein species to extensively cross-link B-cell receptor, which (1) activates B cells via Bt kinases to proliferate, and (2) targets protein to class II major histocompatibility complex (MHC)-loading compartments, efficiently eliciting T-cell help for antibody responses. The review further focuses on protein aggregates as they affect an immunogenicity risk assessment, the use of animal models and studies in uncovering effects of protein aggregates, and changes in product manufacture and packaging that may affect generation of protein aggregates.

  12. Multi-Dimensional Aggregation for Temporal Data

    DEFF Research Database (Denmark)

    Böhlen, M. H.; Gamper, J.; Jensen, Christian Søndergaard

    2006-01-01

    Business Intelligence solutions, encompassing technologies such as multi-dimensional data modeling and aggregate query processing, are being applied increasingly to non-traditional data. This paper extends multi-dimensional aggregation to apply to data with associated interval values that capture...

  13. Aggregation and fibrillation of bovine serum albumin

    DEFF Research Database (Denmark)

    Holm, NK; Jespersen, SK; Thomassen, LV;

    2007-01-01

    The all-alpha helix multi-domain protein bovine serum albumin (BSA) aggregates at elevated temperatures. Here we show that these thermal aggregates have amyloid properties. They bind the fibril-specific dyes Thioflavin T and Congo Red, show elongated although somewhat worm-like morphology...

  14. Open Access: From Myth to Paradox

    Energy Technology Data Exchange (ETDEWEB)

    Ginsparg, Paul (Cornell University)

    2009-05-06

    True open access to scientific publications not only gives readers the possibility to read articles without paying subscription, but also makes the material available for automated ingestion and harvesting by 3rd parties. Once articles and associated data become universally treatable as computable objects, openly available to 3rd party aggregators and value-added services, what new services can we expect, and how will they change the way that researchers interact with their scholarly communications infrastructure? I will discuss straightforward applications of existing ideas and services, including citation analysis, collaborative filtering, external database linkages, interoperability, and other forms of automated markup, and speculate on the sociology of the next generation of users.

  15. Open life science research, open software and the open century

    National Research Council Canada - National Science Library

    Youhua Chen

    2015-01-01

    At the age of knowledge explosion and mass scientific information, I highlighted the importance of conducting open science in life and medical researches through the extensive usage of open software and documents...

  16. Nestin+cells forming spheroids aggregates resembling tumorspheres in experimental ENU-induced gliomas.

    Science.gov (United States)

    García-Blanco, Alvaro; Bulnes, Susana; Pomposo, Iñigo; Carrasco, Alex; Lafuente, José Vicente

    2016-12-01

    Nestin+cells from spheroid aggregates display typical histopathological features compatible with cell stemness. Nestin and CD133+cells found in glioblastomas, distributed frequently around aberrant vessels, are considered as potential cancer stem cells. They are possible targets for antitumoral therapy because they lead the tumorigenesis, invasiveness and angiogenesis. However, little is known about their role and presence in low-grade gliomas. The aim of this work is to localize and characterize the distribution of these cells inside tumors during the development of experimental endogenous glioma. For this study, a single dose of Ethyl-nitrosourea was injected into pregnant rats. Double immunofluorescences were performed in order to identify stem-like and differentiated cells. Low-grade gliomas display Nestin+cells distributed throughout the tumor. More malignant gliomas show, in addition to that, a perivascular location with some Nestin+cells co-expressing CD133 or VEGF, and the intratumoral spheroid aggregates of Nestin/CD133+cells. These structures are encapsulated by well-differentiated VEGF/GFAP+cells. Spheroid aggregates increase in size in the most malignant stages. Spheroid aggregates have morphological and phenotypic similarities to in vitro neurospheres and could be an in vivo analogue of them. These arrangements could be a reservoir of undifferentiated cells formed to escape adverse microenvironments.

  17. Discussion on “Malešev, M.; Radonjanin, V.; Marinković, S. Recycled Concrete as Aggregate for Structural Concrete Production. Sustainability, 2010, 2, 1204-1225”

    Directory of Open Access Journals (Sweden)

    Gholamreza Fathifazl

    2011-02-01

    Full Text Available The authors are to be congratulated for their comprehensive research work on the use of RCA as aggregate in structural grade concrete [1], but some of their conclusions with regard to the effect of aggregate type and RCA content on the fresh and hardened properties of concrete made with coarse RCA, termed RAC for brevity, need discussion.

  18. Role of multicellular aggregates in biofilm formation

    DEFF Research Database (Denmark)

    Kragh, Kasper N.; Hutchison, Jaime B.; Melaugh, Gavin;

    2016-01-01

    response, may add to this ecological benefit. Our findings suggest that current models of biofilm formation should be reconsidered to incorporate the role of aggregates in biofilm initiation.IMPORTANCE During the past decades, there has been a consensus around the model of development of a biofilm......In traditional models of in vitro biofilm development, individual bacterial cells seed a surface, multiply, and mature into multicellular, three-dimensional structures. Much research has been devoted to elucidating the mechanisms governing the initial attachment of single cells to surfaces. However......, in natural environments and during infection, bacterial cells tend to clump as multicellular aggregates, and biofilms can also slough off aggregates as a part of the dispersal process. This makes it likely that biofilms are often seeded by aggregates and single cells, yet how these aggregates impact biofilm...

  19. Excited-state dynamics of astaxanthin aggregates

    Science.gov (United States)

    Fuciman, Marcel; Durchan, Milan; Šlouf, Václav; Keşan, Gürkan; Polívka, Tomáš

    2013-05-01

    Astaxanthin forms three types of aggregates in hydrated dimethyl sulfoxide (DMSO). In DMSO/water ratio of 1:1, a red-shifted J-aggregate with maximum at 570 nm is generated, while a ratio of 1:9 produces blue-shifted H-aggregates with peaks at 386 nm (H1) and 460 nm (H2). Monomeric astaxanthin in DMSO has an S1 lifetime of 5.3 ps, but a long-lived (33 ps) S∗ signal was also identified. Aggregation changes the S1 lifetimes to 17 ps (H1), 30 ps (H2), and 14 ps (J). Triplet state of astaxanthin, most likely generated via singlet homofission, was observed in H1 and H2 aggregates.

  20. Multicandidate Elections: Aggregate Uncertainty in the Laboratory*

    Science.gov (United States)

    Bouton, Laurent; Castanheira, Micael; Llorente-Saguer, Aniol

    2015-01-01

    The rational-voter model is often criticized on the grounds that two of its central predictions (the paradox of voting and Duverger’s Law) are at odds with reality. Recent theoretical advances suggest that these empirically unsound predictions might be an artifact of an (arguably unrealistic) assumption: the absence of aggregate uncertainty about the distribution of preferences in the electorate. In this paper, we propose direct empirical evidence of the effect of aggregate uncertainty in multicandidate elections. Adopting a theory-based experimental approach, we explore whether aggregate uncertainty indeed favors the emergence of non-Duverger’s law equilibria in plurality elections. Our experimental results support the main theoretical predictions: sincere voting is a predominant strategy under aggregate uncertainty, whereas without aggregate uncertainty, voters massively coordinate their votes behind one candidate, who wins almost surely.

  1. Formation of Tethers from Spreading Cellular Aggregates.

    Science.gov (United States)

    Beaune, Grégory; Winnik, Françoise M; Brochard-Wyart, Françoise

    2015-12-01

    Membrane tubes are commonly extruded from cells and vesicles when a point-like force is applied on the membrane. We report here the unexpected formation of membrane tubes from lymph node cancer prostate (LNCaP) cell aggregates in the absence of external applied forces. The spreading of LNCaP aggregates deposited on adhesive glass substrates coated with fibronectin is very limited because cell-cell adhesion is stronger than cell-substrate adhesion. Some cells on the aggregate periphery are very motile and try to escape from the aggregate, leading to the formation of membrane tubes. Tethered networks and exchange of cargos between cells were observed as well. Growth of the tubes is followed by either tube retraction or tube rupture. Hence, even very cohesive cells are successful in escaping aggregates, which may lead to epithelial mesenchymal transition and tumor metastasis. We interpret the dynamics of formation and retraction of tubes in the framework of membrane mechanics.

  2. Ratio-Based Gradual Aggregation of Data

    DEFF Research Database (Denmark)

    Iftikhar, Nadeem

    2012-01-01

    cause data management and data storage issues. However, non-flexible and ineffective means of data aggregation not only reduce performance of database queries but also lead to erroneous reporting. This paper presents flexible and effective ratio-based methods for gradual data aggregation in databases....... Gradual data aggregation is a process that reduces data volume by converting the detailed data into multiple levels of summarized data as the data gets older. This paper also describes implementation strategies of the proposed methods based on standard database technology.......Majority of databases contain large amounts of data, gathered over long intervals of time. In most cases, the data is aggregated so that it can be used for analysis and reporting purposes. The other reason of data aggregation is to reduce data volume in order to avoid over-sized databases that may...

  3. Spatial Aggregation: Data Model and Implementation

    CERN Document Server

    Gomez, Leticia; Kuijpers, Bart; Vaisman, Alejandro

    2007-01-01

    Data aggregation in Geographic Information Systems (GIS) is only marginally present in commercial systems nowadays, mostly through ad-hoc solutions. In this paper, we first present a formal model for representing spatial data. This model integrates geographic data and information contained in data warehouses external to the GIS. We define the notion of geometric aggregation, a general framework for aggregate queries in a GIS setting. We also identify the class of summable queries, which can be efficiently evaluated by precomputing the overlay of two or more of the thematic layers involved in the query. We also sketch a language, denoted GISOLAP-QL, for expressing queries that involve GIS and OLAP features. In addition, we introduce Piet, an implementation of our proposal, that makes use of overlay precomputation for answering spatial queries (aggregate or not). Our experimental evaluation showed that for a certain class of geometric queries with or without aggregation, overlay precomputation outperforms R-tre...

  4. An exact approach for aggregated formulations

    DEFF Research Database (Denmark)

    Gamst, Mette; Spoorendonk, Simon

    optimality cannot be guaranteed by branching on the aggregated variables. In this presentation, we propose a general method for solving aggregated formulations, such that the solution is optimal to the original problem. The method is based on applying Benders’ decomposition on a combination of the original...... to mathematical formulations with a different solution space than that for the original formulation, i.e., the aggregated formulation may be a relaxation of the original problem. In a branch-and-bound context, variable aggregation can also lead to a formulation where branching is not trivial, for example when...... and aggregated formulations. Put in a branch-and-bound context, branching can be performed on the original variables to ensure optimality. We show how to apply the method on well-known optimization problems....

  5. Open Standards, Open Source, and Open Innovation: Harnessing the Benefits of Openness

    Science.gov (United States)

    Committee for Economic Development, 2006

    2006-01-01

    Digitization of information and the Internet have profoundly expanded the capacity for openness. This report details the benefits of openness in three areas--open standards, open-source software, and open innovation--and examines the major issues in the debate over whether openness should be encouraged or not. The report explains each of these…

  6. The Maximal Graded Left Quotient Algebra of a Graded Algebra

    Institute of Scientific and Technical Information of China (English)

    Gonzalo ARANDA PINO; Mercedes SILES MOLINA

    2006-01-01

    We construct the maximal graded left quotient algebra of every graded algebra A without homogeneous total right zero divisors as the direct limit of graded homomorphisms (of left A-modules)from graded dense left ideals of A into a graded left quotient algebra of A. In the case of a superalgebra,and with some extra hypothesis, we prove that the component in the neutral element of the group of the maximal graded left quotient algebra coincides with the maximal left quotient algebra of the component in the neutral element of the group of the superalgebra.

  7. Cutting Class Harms Grades

    Science.gov (United States)

    Taylor, Lewis A., III

    2012-01-01

    An accessible business school population of undergraduate students was investigated in three independent, but related studies to determine effects on grades due to cutting class and failing to take advantage of optional reviews and study quizzes. It was hypothesized that cutting classes harms exam scores, attending preexam reviews helps exam…

  8. Social Studies: Grade 8.

    Science.gov (United States)

    Manitoba Dept. of Education, Winnipeg.

    This Manitoba (Canada) curriculum guide for eighth grade social studies students contains suggested teaching strategies and learning activities in four units covering: (1) life during prehistoric and early historic times; (2) ancient civilizations; (3) life in early modern Europe; and (4) life in the modern world. Each unit includes an overview,…

  9. Purpose-Driven Grading

    Science.gov (United States)

    Carlson, Jane A. K.; Kimpton, Ann

    2010-01-01

    Allowing students to improve their grade by revising their written work may help students learn to revise, but it gives them no incentive to turn in quality work from the start. This article proposes a way to invert the process, thereby teaching students how to revise, while enforcing a more disciplined approach to good writing. (Contains 3…

  10. Endangered Animals. Second Grade.

    Science.gov (United States)

    Popp, Marcia

    This second grade teaching unit centers on endangered animal species around the world. Questions addressed are: What is an endangered species? Why do animals become extinct? How do I feel about the problem? and What can I do? Students study the definition of endangered species and investigate whether it is a natural process. They explore topics…

  11. Multifeature prostate cancer diagnosis and Gleason grading of histological images.

    Science.gov (United States)

    Tabesh, Ali; Teverovskiy, Mikhail; Pang, Ho-Yuen; Kumar, Vinay P; Verbel, David; Kotsianti, Angeliki; Saidi, Olivier

    2007-10-01

    We present a study of image features for cancer diagnosis and Gleason grading of the histological images of prostate. In diagnosis, the tissue image is classified into the tumor and nontumor classes. In Gleason grading, which characterizes tumor aggressiveness, the image is classified as containing a low- or high-grade tumor. The image sets used in this paper consisted of 367 and 268 color images for the diagnosis and Gleason grading problems, respectively, and were captured from representative areas of hematoxylin and eosin-stained tissue retrieved from tissue microarray cores or whole sections. The primary contribution of this paper is to aggregate color, texture, and morphometric cues at the global and histological object levels for classification. Features representing different visual cues were combined in a supervised learning framework. We compared the performance of Gaussian, k-nearest neighbor, and support vector machine classifiers together with the sequential forward feature selection algorithm. On diagnosis, using a five-fold cross-validation estimate, an accuracy of 96.7% was obtained. On Gleason grading, the achieved accuracy of classification into low- and high-grade classes was 81.0%.

  12. Experimental Research on Compounding Concrete with Recycled Aggregates%用再生骨料配制混凝土的试验研究

    Institute of Scientific and Technical Information of China (English)

    张秀芳; 何更新; 赵霄龙

    2011-01-01

    Through the replacement of partial or the whole natural aggregates with recycled coarse aggregate and recycled fine aggregate, the influences of replacement ratios of recycled coarse aggregate and recycled fine aggregate on concrete performance have been investigated. The results showed that with the increasing of replacement ratio of recycled aggregate, the water demand increasing linearly, and the compressive strength and the bulk density reducing. It is pointed out that the replacement ratio of grade I recycled aggregate has no limit, but the replacement ratio of grade II and grade III recycled aggregate should be controlled in 50% for C30 and C40 concrete. Moreover the recycled coarse aggregate and recycled fine aggregate should not be used together in the concrete.%通过分别采用再生粗骨料和再生细骨料取代部分或全部天然砂石骨料,研究再生粗(细)骨料取代率对混凝土性能的影响.试验结果表明,随着再生粗(细)骨料取代率的提高,混凝土用水量呈线性增加,而抗压强度呈线性下降,表观密度也随之下降.最后指出Ⅰ类再生骨料取代率可不受限制,对于C30,C40混凝土Ⅱ,Ⅲ类宜在50%以内,且不宜同时掺再生粗骨料和再生细骨料.

  13. The fractal aggregation of asphaltenes.

    Science.gov (United States)

    Hoepfner, Michael P; Fávero, Cláudio Vilas Bôas; Haji-Akbari, Nasim; Fogler, H Scott

    2013-07-16

    This paper discusses time-resolved small-angle neutron scattering results that were used to investigate asphaltene structure and stability with and without a precipitant added in both crude oil and model oil. A novel approach was used to isolate the scattering from asphaltenes that are insoluble and in the process of aggregating from those that are soluble. It was found that both soluble and insoluble asphaltenes form fractal clusters in crude oil and the fractal dimension of the insoluble asphaltene clusters is higher than that of the soluble clusters. Adding heptane also increases the size of soluble asphaltene clusters without modifying the fractal dimension. Understanding the process of insoluble asphaltenes forming fractals with higher fractal dimensions will potentially reveal the microscopic asphaltene destabilization mechanism (i.e., how a precipitant modifies asphaltene-asphaltene interactions). It was concluded that because of the polydisperse nature of asphaltenes, no well-defined asphaltene phase stability envelope exists and small amounts of asphaltenes precipitated even at dilute precipitant concentrations. Asphaltenes that are stable in a crude oil-precipitant mixture are dispersed on the nanometer length scale. An asphaltene precipitation mechanism is proposed that is consistent with the experimental findings. Additionally, it was found that the heptane-insoluble asphaltene fraction is the dominant source of small-angle scattering in crude oil and the previously unobtainable asphaltene solubility at low heptane concentrations was measured.

  14. Congested Aggregation via Newtonian Interaction

    Science.gov (United States)

    Craig, Katy; Kim, Inwon; Yao, Yao

    2017-08-01

    We consider a congested aggregation model that describes the evolution of a density through the competing effects of nonlocal Newtonian attraction and a hard height constraint. This provides a counterpoint to existing literature on repulsive-attractive nonlocal interaction models, where the repulsive effects instead arise from an interaction kernel or the addition of diffusion. We formulate our model as the Wasserstein gradient flow of an interaction energy, with a penalization to enforce the constraint on the height of the density. From this perspective, the problem can be seen as a singular limit of the Keller-Segel equation with degenerate diffusion. Two key properties distinguish our problem from previous work on height constrained equations: nonconvexity of the interaction kernel (which places the model outside the scope of classical gradient flow theory) and nonlocal dependence of the velocity field on the density (which causes the problem to lack a comparison principle). To overcome these obstacles, we combine recent results on gradient flows of nonconvex energies with viscosity solution theory. We characterize the dynamics of patch solutions in terms of a Hele-Shaw type free boundary problem and, using this characterization, show that in two dimensions patch solutions converge to a characteristic function of a disk in the long-time limit, with an explicit rate on the decay of the energy. We believe that a key contribution of the present work is our blended approach, combining energy methods with viscosity solution theory.

  15. The Effect of Morphological Characteristic of Coarse Aggregates Measured with Fractal Dimension on Asphalt Mixture’s High-Temperature Performance

    Directory of Open Access Journals (Sweden)

    Hainian Wang

    2016-01-01

    Full Text Available The morphological properties of coarse aggregates, such as shape, angularity, and surface texture, have a great influence on the mechanical performance of asphalt mixtures. This study aims to investigate the effect of coarse aggregate morphological properties on the high-temperature performance of asphalt mixtures. A modified Los Angeles (LA abrasion test was employed to produce aggregates with various morphological properties by applying abrasion cycles of 0, 200, 400, 600, 800, 1000, and 1200 on crushed angular aggregates. Based on a laboratory-developed Morphology Analysis System for Coarse Aggregates (MASCA, the morphological properties of the coarse aggregate particles were quantified using the index of fractal dimension. The high-temperature performances of the dense-graded asphalt mixture (AC-16, gap-graded stone asphalt mixture (SAC-16, and stone mastic asphalt (SMA-16 mixtures containing aggregates with different fractal dimensions were evaluated through the dynamic stability (DS test and the penetration shear test in laboratory. Good linear correlations between the fractal dimension and high-temperature indexes were obtained for all three types of mixtures. Moreover, the results also indicated that higher coarse aggregate angularity leads to stronger high-temperature shear resistance of asphalt mixtures.

  16. Aggregate breakup in a contracting nozzle.

    Science.gov (United States)

    Soos, Miroslav; Ehrl, Lyonel; Bäbler, Matthäus U; Morbidelli, Massimo

    2010-01-05

    The breakup of dense aggregates in an extensional flow was investigated experimentally. The flow was realized by pumping the suspension containing the aggregates through a contracting nozzle. Variation of the cluster mass distribution during the breakage process was measured by small-angle light scattering. Because of the large size of primary particles and the dense aggregate structure image analysis was used to determine the shape and structure of the produced fragments. It was found, that neither aggregate structure, characterized by a fractal dimension d(f) = 2.7, nor shape, characterized by an average aspect ratio equal to 1.5, was affected by breakage. Several passes through the nozzle were required to reach the steady state. This is explained by the radial variation of the hydrodynamic stresses at the nozzle entrance, characterized through computational fluid dynamics, which implies that only the fraction of aggregates whose strength is smaller than the local hydrodynamic stress is broken during one pass through the nozzle. Scaling of the steady-state aggregate size as a function of the hydrodynamic stress was used to determine the aggregate strength.

  17. The natural silk spinning process. A nucleation-dependent aggregation mechanism?

    Science.gov (United States)

    Li, G; Zhou, P; Shao, Z; Xie, X; Chen, X; Wang, H; Chunyu, L; Yu, T

    2001-12-01

    The spinning mechanism of natural silk has been an open issue. In this study, both the conformation transition from random coil to beta sheet and the beta sheet aggregation growth of silk fibroin are identified in the B. mori regenerated silk fibroin aqueous solution by circular dichroism (CD) spectroscopy. A nucleation-dependent aggregation mechanism, similar to that found in prion protein, amyloid beta (Abeta) protein, and alpha-synuclein protein with the conformation transition from a soluble protein to a neurotoxic, insoluble beta sheet containing aggregate, is a novel suggestion for the silk spinning process. We present evidence that two steps are involved in this mechanism: (a) nucleation, a rate-limiting step involving the conversion of the soluble random coil to insoluble beta sheet and subsequently a series of thermodynamically unfavorable association of beta sheet unit, i.e. the formation of a nucleus or seed; (b) once the nucleus forms, further growth of the beta sheet unit becomes thermodynamically favorable, resulting a rapid extension of beta sheet aggregation. The aggregation growth follows a first order kinetic process with respect to the random coil fibroin concentration. The increase of temperature accelerates the beta sheet aggregation growth if the beta sheet seed is introduced into the random coil fibroin solution. This work enhances our understanding of the natural silk spinning process in vivo.

  18. EFFECTS OF CARVEDILOL ON PLATELET AGGREGATION IN MEN WITH ST-ELEVATION ACUTE MYOCARDIAL INFARCTION

    Directory of Open Access Journals (Sweden)

    A. N. Zakirova

    2010-01-01

    Full Text Available Aim. To study influence of beta-blockers carvedilol and metoprolol tartrate on platelet aggregative ability, evaluated by three different methods, in patients with acute ST segment elevation myocardial infarction (STEMI.Material and methods. A total of 86 men aged 36-68 with uncomplicated STEMI were included into an open, comparative, randomized study. Patients were randomized into two groups of beta-blocker treatments. Patients (n=44 of the first group received carvedilol; patients (n=42 of the second one - metoprolol tartrate. Parameters of platelet hemostasis: the maximum amplitude and rate of platelet aggregation induced by ADP, ristomycin and collagen; mean platelet volume (MPV; serum level of soluble CD40 ligand (sCD40L were evaluated on the 2nd and 24th day after STEMI onset.Results. In patients with uncomplicated STEMI carvedilol more prominently reduced in vitro platelet aggregation induced by adenozin-5'-diphosphate in high concentration, ristomycin and collagen than metoprolol tartrate. Сarvedilol also more significantly decreased MPV in comparison with metoprolol tartrate. However, effect of both carvedilol and metoprolol tartrate on the level of another platelet aggregation marker - sCD40L was comparable.Conclusion. Carvedilol and metoprolol tartrate have similar effect on platelet aggregation though in according to some tests carvedilol more prominently reduces platelet aggregation than metoprolol tartrate.

  19. Write More, Grade Less: Five Practices for Effectively Grading Writing

    Science.gov (United States)

    Lucas, Lisa

    2012-01-01

    One of the dilemmas that teachers frequently face is grading student papers. As a teacher, the author regularly reads research regarding instructional practices, grading, and assessment, but struggled to translate theory into practice in her own classroom. The intent of this article is to share one method of instructing and grading writing that…

  20. Linear aggregation theory in cell biology

    Energy Technology Data Exchange (ETDEWEB)

    Hill, T.L.

    1987-01-01

    This is an account of the theory, probability, and thermodynamics of linear aggregation. The emphasis is on basic principles illustrated by simple models, not on particular applications or polymers. The general physical aggregate systems - attached single-stranded polymers, single-stranded polymers modified by a second component, long multistranded polymers, attached multistranded polymers - are given extensive treatment. Also included are a discussion of the GTPase and ATPase activity accompanying the aggregation of microtubules and action, and the properties of the kinetic two-phase model of the end of a microtubule.

  1. Aggregate Formed by a Cationic Fluorescence Probe

    Institute of Scientific and Technical Information of China (English)

    TIAN, Juan; SANG, Da-Yong; JI, Guo-Zhen

    2007-01-01

    The aggregation behavior of a cationic fluorescence probe 10-(4,7,10,13,16-pentaoxa-1-azacyclooctadecyl-methyl)anthracen-9-ylmethyl dodecanoate (1) was observed and studied by a fluorescence methodology in acidic and neutral conditions. By using the Py scale, differences between simple aggregates and micelles have been discussed. The stability of simple aggregates was discussed in terms of hydrophobic interaction and electrostatic repulsion. The absence of excimer emission of the anthrancene moiety of probe 1 in neutral condition was attributed to the photoinduced electron transfer mechanism instead of photodimerization.

  2. Ratio-Based Gradual Aggregation of Data

    DEFF Research Database (Denmark)

    Iftikhar, Nadeem

    2012-01-01

    Majority of databases contain large amounts of data, gathered over long intervals of time. In most cases, the data is aggregated so that it can be used for analysis and reporting purposes. The other reason of data aggregation is to reduce data volume in order to avoid over-sized databases that ma....... Gradual data aggregation is a process that reduces data volume by converting the detailed data into multiple levels of summarized data as the data gets older. This paper also describes implementation strategies of the proposed methods based on standard database technology....

  3. Directional sensing and streaming in Dictyostelium aggregation.

    Science.gov (United States)

    Almeida, Sofia; Dilão, Rui

    2016-05-01

    We merge the Kessler-Levine simple discrete model for Dictyostelium cyclic adenosine monophosphate (cAMP) production and diffusion with the Dilão-Hauser directional sensing aggregation mechanism. The resulting compound model describes all the known transient patterns that emerge during Dictyostelium aggregation, which include the spontaneous formation of cAMP self-sustained target and spiral waves and streaming. We show that the streaming patterns depend on the speed of the amoebae, on the relaxation time for the production of cAMP, on the cAMP degradation rate, and on directional sensing. Moreover, we show that different signaling centers emerge during Dictyostelium aggregation.

  4. Programming spiders, bots, and aggregators in Java

    CERN Document Server

    Heaton, Jeff

    2006-01-01

    The content and services available on the web continue to be accessed mostly through direct human control. But this is changing. Increasingly, users rely on automated agents that save them time and effort by programmatically retrieving content, performing complex interactions, and aggregating data from diverse sources. Programming Spiders, Bots, and Aggregators in Java teaches you how to build and deploy a wide variety of these agents-from single-purpose bots to exploratory spiders to aggregators that present a unified view of information from multiple user accounts. You will quickly build on

  5. Aggregation and Control of Flexible Consumers

    DEFF Research Database (Denmark)

    Biegel, Benjamin; Andersen, Palle; Stoustrup, Jakob

    2014-01-01

    In this paper, we present an architecture for aggregation and co ntrol of a portfolio of flexible consumers. The architecture makes it possible to control the aggregated consumption of the portfolio to follow a power reference while honoring local consumer constraints. Hereby, an aggregator is able...... to utilize a portfolio of consumers as a virtual power plant to deliver services in the electricity markets. The architecture is implemented and demonstrated in a field test on a portfolio consisting of 54 heat pumps each located in an inhabited household. In this demonstration, a power reference varying...

  6. Determinants for grading Malaysian rice

    Science.gov (United States)

    ChePa, Noraziah; Yusoff, Nooraini; Ahmad, Norhayati

    2016-08-01

    Due to un-uniformity of rice grading practices in Malaysia, zones which actively producing rice in Malaysia are using their own way of grading rice. Rice grading is important in determining rice quality and its subsequent price in the market. It is an important process applied in the rice production industry with the purpose of ensuring that the rice produced for the market meets the quality requirements of consumer. Two important aspects that need to be considered in determining rice grades are grading technique and determinants to be used for grading (usually referred as rice attributes). This article proposes the list of determinants to be used in grading Malaysian rice. Determinants were explored through combination of extensive literature review and series of interview with the domain experts and practitioners. The proposed determinants are believed to be beneficial to BERNAS in improving the current Malaysian rice grading process.

  7. Acid Resistance of Concrete Containing Laterite Aggregate as Partial Coarse Aggregate Replacement

    Directory of Open Access Journals (Sweden)

    K. Muthusamy

    2014-05-01

    Full Text Available In Malaysia, issues of granite aggregate depletion in future due to increasing use in concrete industry and the availability of laterite aggregate locally has initiated studies on concrete produced using laterite aggregate as partial coarse aggregate replacement. Although, replacement of laterite aggregate up to 30% able to produce concrete with the targeted strength but durability of this concrete towards acid attack yet to be investigated. Thus, this study presents and discusses the performance of concrete consisting various percentage of laterite aggregate integrated as partial coarse aggregate replacement upon exposure to acidic environment. Mixes consisting various content of laterite aggregate as partial coarse aggregate replacement ranging from 0, 10, 20, 30, 40 and 50%, respectively were prepared in form of cubes and then subjected to water curing for 28 days before immersed in hydrochloric acid solution for 1800 h. Performance of the specimens were observed through mass loss and strength reduction. Generally, durability performance of concrete produced using up to 20% of laterite aggregate is comparable to plain concrete.

  8. Structure and kinetics of shear aggregation in turbulent flows. I. Early stage of aggregation.

    Science.gov (United States)

    Bäbler, Matthäus U; Moussa, Amgad S; Soos, Miroslav; Morbidelli, Massimo

    2010-08-17

    Aggregation of rigid colloidal particles leads to fractal-like structures that are characterized by a fractal dimension d(f) which is a key parameter for describing aggregation processes. This is particularly true in shear aggregation where d(f) strongly influences aggregation kinetics. Direct measurement of d(f) in the early stages of shear aggregation is however difficult, as the aggregates are small and few in number. An alternative method for determining d(f) is to use an aggregation model that when fitted to the time evolution of the cluster mass distribution allows for estimating d(f). Here, we explore three such models, two of which are based on an effective collision sphere and one which directly incorporates the permeable structure of the aggregates, and we apply them for interpreting the initial aggregate growth measured experimentally in a turbulent stirred tank reactor. For the latter, three polystyrene latexes were used that differed only in the size of the primary particles (d(p) = 420, 600, and 810 nm). It was found that all three models describe initial aggregation kinetics reasonably well using, however, substantially different values for d(f). To discriminate among the models, we therefore also studied the regrowth of preformed aggregates where d(f) was experimentally accessible. It was found that only the model that directly incorporates the permeable structure of the aggregates is able to predict correctly this second type of experiments. Applying this model to the initial aggregation kinetics, we conclude that the actual initial fractal dimension is d(f) = 2.07 +/- 0.04 as found from this model.

  9. p53 Aggregates penetrate cells and induce the co-aggregation of intracellular p53.

    Directory of Open Access Journals (Sweden)

    Karolyn J Forget

    Full Text Available Prion diseases are unique pathologies in which the infectious particles are prions, a protein aggregate. The prion protein has many particular features, such as spontaneous aggregation, conformation transmission to other native PrP proteins and transmission from an individual to another. Protein aggregation is now frequently associated to many human diseases, for example Alzheimer's disease, Parkinson's disease or type 2 diabetes. A few proteins associated to these conformational diseases are part of a new category of proteins, called prionoids: proteins that share some, but not all, of the characteristics associated with prions. The p53 protein, a transcription factor that plays a major role in cancer, has recently been suggested to be a possible prionoid. The protein has been shown to accumulate in multiple cancer cell types, and its aggregation has also been reproduced in vitro by many independent groups. These observations suggest a role for p53 aggregates in cancer development. This study aims to test the «prion-like» features of p53. Our results show in vitro aggregation of the full length and N-terminally truncated protein (p53C, and penetration of these aggregates into cells. According to our findings, the aggregates enter cells using macropinocytosis, a non-specific pathway of entry. Lastly, we also show that once internalized by the cell, p53C aggregates can co-aggregate with endogenous p53 protein. Together, these findings suggest prion-like characteristics for p53 protein, based on the fact that p53 can spontaneously aggregate, these aggregates can penetrate cells and co-aggregate with cellular p53.

  10. Inflated Grades, Enrollments & Budgets

    Directory of Open Access Journals (Sweden)

    J. E. Stone

    1995-06-01

    Full Text Available Reports of the past 13 years that call attention to deficient academic standards in American higher education are enumerated. Particular attention is given the Wingspread Group's recent An American Imperative: Higher Expectations for Higher Education. Low academic standards, grade inflation, and budgetary incentives for increased enrollment are analyzed and a call is made for research at the state level. Reported trends in achievement and GPAs are extrapolated to Tennessee and combined with local data to support the inference that 15% of the state's present day college graduates would not have earned a diploma by mid 1960s standards. A conspicuous lack of interest by public oversight bodies is noted despite a growing public awareness of low academic expectations and lenient grading and an implicit budgetary impact of over $100 million. Various academic policies and the dynamics of bureaucratic control are discussed in relationship to the maintenance of academic standards. The disincentives for challenging course requirements and responsible grading are examined, and the growing movement to address academic quality issues through better training and supervision of faculty are critiqued. Recommendations that would encourage renewed academic integrity and make learning outcomes visible to students, parents, employers, and the taxpaying public are offered and briefly discussed.

  11. Study on Strength of Concrete Using Robo Sand as a Partial Replacement of Fine Aggregate

    Directory of Open Access Journals (Sweden)

    S.Rukmangadhara Rao,

    2015-12-01

    Full Text Available Robo sand is one of the most used among such materials to replace river sand, which can be used as an alternative to fine aggregate in concrete. In the present investigation workability and strength of concrete was evaluated by replacement of natural sand by Robo sand in proportions of 0%, 50%, 75%, and 100% is studied for M25and M35grade concrete cubes, cylinders and prisms. Slump cone method is taken for finding workability. For strength parameters for each grade of concrete Cubes, Cylinders and Prisms were casted and tested at the age of 7 and 28 days. In this present experimental study on concrete having grades of M25 and M35 are prepared by replacing natural sand by Robo sand. Concrete specimens were tested for evaluation of compressive strength and water absorption.

  12. Sandia OpenSHMEM

    Energy Technology Data Exchange (ETDEWEB)

    2016-03-15

    Sandia OpenSHMEM is an implementation of the OpenSHMEM Standard over the Portals 4 Networking API and the OpenFabrics Interface (OFI). Sandia OpenSHMEM is designed to be a low-overhead implementation of the OpenSHMEM standard which takes advantage of the many features of the Portals 4 specification.

  13. Open access, open education resources and open data in Uganda.

    Science.gov (United States)

    Salvo, Ivana Di; Mwoka, Meggie; Kwaga, Teddy; Rukundo, Priscilla Aceng; Ernest, Dennis Ssesanga; Osaheni, Louis Aikoriogie; John, Kasibante; Shafik, Kasirye; de Sousa, Agostinho Moreira

    2015-01-01

    As a follow up to OpenCon 2014, International Federation of Medical Students' Associations (IFMSA) students organized a 3 day workshop Open Access, Open Education Resources and Open Data in Kampala from 15-18 December 2014. One of the aims of the workshop was to engage the Open Access movement in Uganda which encompasses the scientific community, librarians, academia, researchers and students. The IFMSA students held the workshop with the support of: Consortium for Uganda University Libraries (CUUL), The Right to Research Coalition, Electronic Information for Libraries (EIFL), Makerere University, International Health Sciences University (IHSU), Pan African Medical Journal (PAMJ) and the Centre for Health Human Rights and Development (CEHURD). All these organizations are based or have offices in Kampala. The event culminated in a meeting with the Science and Technology Committee of Parliament of Uganda in order to receive the support of the Ugandan Members of Parliament and to make a concrete change for Open Access in the country.

  14. How do Openers Contribute to Student Learning?

    Directory of Open Access Journals (Sweden)

    Amber ZERTUCHE

    2012-10-01

    Full Text Available Openers, or brief activities that initiate a class, routinely take up classroom time each day yet little is known about how to design these activities so they contribute to student learning. This study usestechnology-enhanced learning environments to explore new opportunities to transform Openers from potentially busy work to knowledge generating activities. This study compares the impact ofteacher-designed Openers, Opener designs based on recent research emphasizing knowledge integration, and no Opener for an 8th grade technology-enhanced inquiry science investigation. Results suggest that students who participate in a researcher-designed Opener are more likely to revisit and refine their work, and to make significant learning gains, than students who do not participate in an Opener. Students make the greatest gains when they revisit key evidence in thetechnology-enhanced curriculum unit prior to revision. Engaging students in processes that promote knowledge integration during the Opener motivate students to revise their ideas. The results suggestdesign principles for Openers in technology-enhanced instruction.

  15. GPP Webinar: The Power of Aggregated Purchasing

    Science.gov (United States)

    Green Power Partnership webinar examining the use of an aggregated model for renewable energy purchases which can lead to significant energy, environmental and financial benefits by addressing administrative cost barriers and leveraging the shared purchasi

  16. Familial aggregation and childhood blood pressure.

    Science.gov (United States)

    Wang, Xiaoling; Xu, Xiaojing; Su, Shaoyong; Snieder, Harold

    2015-01-01

    There is growing concern about elevated blood pressure (BP) in children. The evidence for familial aggregation of childhood BP is substantial. Twin studies have shown that a large part of the familial aggregation of childhood BP is due to genes. The first part of this review provides the latest progress in gene finding for childhood BP, focusing on the combined effects of multiple loci identified from the genome-wide association studies on adult BP. We further review the evidence on the contribution of the genetic components of other family risk factors to the familial aggregation of childhood BP including obesity, birth weight, sleep quality, sodium intake, parental smoking, and socioeconomic status. At the end, we emphasize the promise of using genomic-relatedness-matrix restricted maximum likelihood (GREML) analysis, a method that uses genome-wide data from unrelated individuals, in answering a number of unsolved questions in the familial aggregation of childhood BP.

  17. Suspensions of colloidal particles and aggregates

    CERN Document Server

    Babick, Frank

    2016-01-01

    This book addresses the properties of particles in colloidal suspensions. It has a focus on particle aggregates and the dependency of their physical behaviour on morphological parameters. For this purpose, relevant theories and methodological tools are reviewed and applied to selected examples. The book is divided into four main chapters. The first of them introduces important measurement techniques for the determination of particle size and interfacial properties in colloidal suspensions. A further chapter is devoted to the physico-chemical properties of colloidal particles—highlighting the interfacial phenomena and the corresponding interactions between particles. The book’s central chapter examines the structure-property relations of colloidal aggregates. This comprises concepts to quantify size and structure of aggregates, models and numerical tools for calculating the (light) scattering and hydrodynamic properties of aggregates, and a discussion on van-der-Waals and double layer interactions between ...

  18. Fish Aggregation Sites in the Florida Keys

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Spawning aggregations are an important event in the life-history of many coral reef fish species. During short time periods (typically during full moons), fish will...

  19. Active matter model of Myxococcus xanthus aggregation

    Science.gov (United States)

    Patch, Adam; Bahar, Fatmagul; Liu, Guannan; Thutupalli, Shashi; Welch, Roy; Yllanes, David; Shaevitz, Joshua; Marchetti, M. Cristina

    Myxococcus xanthus is a soil-dwelling bacterium that exhibits several fascinating collective behaviors including streaming, swarming, and generation of fruiting bodies. A striking feature of M. xanthus is that it periodically reverses its motility direction. The first stage of fruiting body formation is characterized by the aggregation of cells on a surface into round mesoscopic structures. Experiments have shown that this aggregation relies heavily on regulation of the reversal rate and local mechanical interactions, suggesting motility-induced phase separation may play an important role. We have adapted self-propelled particle models to include cell reversal and motility suppression resulting from sporulation observed in aggregates. Using 2D molecular dynamics simulations, we map the phase behavior in the space of Péclet number and local density and examine the kinetics of aggregation for comparison to experiments.

  20. A Survey of Distributed Data Aggregation Algorithms

    CERN Document Server

    Jesus, Paulo; Almeida, Paulo Sérgio

    2011-01-01

    Distributed data aggregation is an important task, allowing the decentralized determination of meaningful global properties, that can then be used to direct the execution of other applications. The resulting values result from the distributed computation of functions like COUNT, SUM and AVERAGE. Some application examples can found to determine the network size, total storage capacity, average load, majorities and many others. In the last decade, many different approaches have been proposed, with different trade-offs in terms of accuracy, reliability, message and time complexity. Due to the considerable amount and variety of aggregation algorithms, it can be difficult and time consuming to determine which techniques will be more appropriate to use in specific settings, justifying the existence of a survey to aid in this task. This work reviews the state of the art on distributed data aggregation algorithms, providing three main contributions. First, it formally defines the concept of aggregation, characterizin...

  1. Disproportionate mosquito feeding on aggregated hosts.

    Science.gov (United States)

    Foppa, Ivo M; Moore, Jerrilynn; Caillouët, Kevin A; Wesson, Dawn M

    2011-11-01

    Despite the importance of per-capita feeding rates for mosquito-borne transmission dynamics, the relationship between host aggregation and per-capita feeding rates remains poorly characterized. We conducted indoor experiments to investigate how Culex quinquefasciatus (Say) mosquitoes distribute their blood feeding on variably aggregated domestic chickens (Callus gallus domesticus L.) (one chicken vs. a flock of seven to nine birds). Mosquitoes were always more likely to feed on the larger chicken group; yet, the single chicken tended to be fed on at a higher per-capita rate. When 10 chickens were available the feeding intensity was 4.5 times higher for the single chicken compared with the flock. We conclude that more highly aggregated hosts may experience lower exposure to mosquito bites than less aggregated hosts.

  2. Concretes with red mud coarse aggregates

    Directory of Open Access Journals (Sweden)

    Dênio Ramam Carvalho de Oliveira

    2012-06-01

    Full Text Available Red mud (RM is a mineral waste, residue of the Bayer process used to obtain alumina from bauxite. While the exploration of rolled pebble damages the environment and is much more controlled by the government, the huge RM disposal areas do not stop increasing and polluting soil, rivers and groundwater sources in Amazon. In this work, the material mixtures used to produce coarse aggregates presented up to 80% of RM, 30% of metakaolin and 30% of active silica as recycled waste. Several tests were carried out to determine the aggregates physical properties and to evaluate the mechanical performance of the concretes with the new aggregates, including hydraulic abrasion strength, and the results were compared to the reference ones, i.e. rolled pebble concretes. Additionally, the sintering process neutralizes any toxic substance as occur in some RM products like tiles and bricks, and these results have encouraged an industrial or semi-industrial production of RM aggregates for concretes.

  3. Quicklime application instantly increases soil aggregate stability

    Science.gov (United States)

    Keiblinger, Katharina M.; Bauer, Lisa M.; Deltedesco, Evi; Holawe, Franz; Unterfrauner, Hans; Zehetner, Franz; Peticzka, Robert

    2016-01-01

    Agricultural intensification, especially enhanced mechanisation of soil management, can lead to the deterioration of soil structure and to compaction. A possible amelioration strategy is the application of (structural) lime. In this study, we tested the effect of two different liming materials, ie limestone (CaCO3) and quicklime (CaO), on soil aggregate stability in a 3-month greenhouse pot experiment with three agricultural soils. The liming materials were applied in the form of pulverised additives at a rate of 2 000 kg ha-1. Our results show a significant and instantaneous increase of stable aggregates after quicklime application whereas no effects were observed for limestone. Quicklime application seems to improve aggregate stability more efficiently in soils with high clay content and cation exchange capacity. In conclusion, quicklime application may be a feasible strategy for rapid improvement of aggregate stability of fine textured agricultural soils.

  4. Blue-emitting pyrene-based aggregates.

    Science.gov (United States)

    Valera, Jorge S; Calbo, Joaquín; Gómez, Rafael; Ortí, Enrique; Sánchez, Luis

    2015-06-25

    The supramolecular polymerization of pyrene imidazoles 1 and 2, governed by H-bonding and C-H···π interactions, yields aggregates showing the characteristic bluish emission pattern of pyrene-based monomers.

  5. Nanoscale Ionic Aggregate Morphology in Zwitterionic Copolymers

    Science.gov (United States)

    Choi, Jae-Hong; Huyck, Rebecca; Salas-de La Cruz, David; Long, Timothy E.; Winey, Karen I.

    2009-03-01

    The morphology of two different zwitterionic copolymers, poly(sulfobetaine methacrylate-ran-butyl acrylate), and poly(sulfobetaine methacrylamide-ran-butyl acrylate) are investigated as a function of the mol % content of SBMA (7 and 9 mol %) and SBMAm (6, 10 and 13 mol %), respectively. In both copolymers, X-ray scattering results show a new structure in the material arising from ionic aggregates. The sizes of the ionic aggregates are obtained through the scattering model. The sizes of the ionic aggregates increase as the ion content increases. The application of scanning transmission electron microscopy to the study of ionomer morphology has enabled direct, model-independent visualization of the ionic aggregates. The correlation between X-ray scattering results and the real space imaging for morphology of these zwitterionic copolymers will be presented.

  6. Geopolymerization of lightweight aggregate waste

    Directory of Open Access Journals (Sweden)

    Labrincha, J. A.

    2008-09-01

    Full Text Available Geopolymerization is a viable way to process and re-use alumino-silicate industrial waste while producing highstrength, high chemical inertia materials that can effectively immobilize other industrial by-products, and even hazardous waste. In this study industrial waste from different stages of the manufacture of lightweight expanded clay aggregate was characterized for its possible transformation, via alkali activation, to geopolymers. The ultimate aim was to assess the possibility of using such geopolymers to develop thermal and acoustic insulation panels. The containment of hazardous materials is another important application for these new materials. Geopolymers were prepared for this study with different particles size distributions and activator concentrations. Their mechanical properties, composition and microstructure were characterized and a material with promising insulating properties was produced. A preliminary analysis was conducted of the salt formation observed in these geopolymers, the chief drawback to their use.La geopolimerización es una manera viable para procesar y agregar valor a los residuos industriales de alumino-silicato dando lugar a materiales con elevadas resistencias mecánmicas, alta inercia química y que permiten encapsular otros residuos, incluso peligrosos. Los residuos industriales que proceden de diversos tipos de arcillas para la fabricación de áridos ligeros se han caracterizado para la producción de geopolímeros mediante el proceso de ataque alcalino. Su incorporación en una matriz geopolimérica permite la posibilidad de desarrollo de paneles de aislamiento (térmico y acústico. Además, la inmovilización de materiales peligrosos es un logro adicional importante. Los geopolímeros se han producido con fórmulas diferentes y se han caracterizado sus propiedades mecánicas, composición y microestructura, para dar lugar a una composición interesante con propiedades aislantes. Se ha llevado a cabo

  7. Control of aggregation-induced emission by DNA hybridization

    OpenAIRE

    Li, Shaoguang; Langenegger, Simon Matthias; Häner, Robert

    2013-01-01

    Aggregation-induced emission (AIE) was studied by hybridization of dialkynyl-tetraphenylethylene (DATPE) modified DNA strands. Molecular aggregation and fluorescence of DATPEs are controlled by duplex formation.

  8. Probability Aggregates in Probability Answer Set Programming

    OpenAIRE

    Saad, Emad

    2013-01-01

    Probability answer set programming is a declarative programming that has been shown effective for representing and reasoning about a variety of probability reasoning tasks. However, the lack of probability aggregates, e.g. {\\em expected values}, in the language of disjunctive hybrid probability logic programs (DHPP) disallows the natural and concise representation of many interesting problems. In this paper, we extend DHPP to allow arbitrary probability aggregates. We introduce two types of p...

  9. Bacterial Association with Particles: Aggregation to Dissolution

    Digital Repository Service at National Institute of Oceanography (India)

    DeSouza, M.J.B.D.

    concentrations which is faster than even starving bacteria burn up their reserves, and bacteria may therefore rely solely on aggregates for food. They pointed out that the encounter rate between aggregates and free bacteria is independent of processes... (Green and Dagg, 1997; Grossart et al., 1998, Kiorboe, 2000, Rickard et al., 2002). Many microbial ecologists reported attachment by many species directly to particles, either to use the abundant attached bacterial community as a food source or to feed...

  10. Low aggregation state diminishes ferrihydrite reactivity

    Science.gov (United States)

    Braunschweig, Juliane; Heister, Katja; Meckenstock, Rainer U.

    2013-04-01

    Ferrihydrite is an abundant iron(oxy)hydroxide in soils and sediments and plays an important role in microbial iron cycling due to its high reactivity. Therefore, it is often synthesized and used in geomicrobiological and mineralogical studies. The reactivities of synthetic ferrihydrites vary between different studies and synthesis protocols. Hence, we synthesized five different ferrihydrites and characterized them with XRD, FTIR, XPS, and BET specific surface area. The reactivity of the ferrihydrite samples towards ascorbic acid was examined and compared with microbial reduction rates by Geobacter sulfurreducens. FTIR and XRD results show the presence of secondary, higher crystalline iron oxide phases like goethite and akaganeite for two samples. Consequently, those samples revealed lower biotic and abiotic reduction rates compared to pure ferrihydrite. Comparison of reduction rates with the specific surface area of all ferrihydrites showed neither correlation with abiotic reductive dissolution nor with microbial reduction. Especially one sample, characterized by a very low aggregation state and presence of secondary minerals, revealed a poor reactivity. We speculate that apart from the occurring secondary minerals also the low aggregation state played an important role. Decreasing aggregation diminishes the amount of kinks and edges on the surfaces, which are produced at contact sites in aggregates. According to dissolution theories, dissolution mainly starts at those surface defects and slows down with decreasing amount of defects. Furthermore, the non-aggregated ferrihydrite is free of micropores, a further stimulant for dissolution. Independent repetitions of experiments and syntheses according to the same protocol but without formation of secondary minerals, confirmed the low reactivity of the non-aggregated ferrihydrite. In summary, our results indicate that a decreasing aggregation state of ferrihydrite to a certain size does increase the reactivity

  11. Menu Costs, Aggregate Fluctuations and Large Shocks

    OpenAIRE

    Karadi, Peter; Reiff, Adam

    2014-01-01

    In menu cost models, real effects of aggregate nominal shocks are sensitive to unobserved characteristics of price setting. The standard way to calibrate key pricing parameters is to match the cross-sectional distribution of price changes. We argue that this unconditional distribution contains insufficient information for a clean identification. In particular, it is consistent with parameterizations with contradictory aggregate implications: one generating sizeable real effects, the other eff...

  12. Aggregation kinetics of coalescing polymer colloids.

    Science.gov (United States)

    Gauer, Cornelius; Jia, Zichen; Wu, Hua; Morbidelli, Massimo

    2009-09-01

    The aggregation behavior of a soft, rubbery colloidal system with a relatively low glass transition temperature, T(g) approximately -20 degrees C, has been investigated. It is found that the average gyration and hydrodynamic radii, R(g) and R(h), measured by light scattering techniques, evolve in time in parallel, without exhibiting the crossover typical of rigid particle aggregation. Cryogenic scanning electron microscopy (cryo-SEM) images reveal sphere-like clusters, indicating that complete coalescence between particles occurs during aggregation. Since coalescence leads to a reduction in the total colloidal surface area, the surfactant adsorption equilibrium, and thus the colloidal stability, change in the course of aggregation. It is found that to simulate the observed kinetic behavior based on the population balance equations, it is necessary to assume that all the clusters are spherical and to account for variations in the colloidal stability of each aggregating particle pair with time. This indicates that, for the given system, the coalescence is very fast, i.e., its time scale is much smaller than that of the aggregation.

  13. Paper Sludge Reuse in Lightweight Aggregates Manufacturing.

    Science.gov (United States)

    Chen, How-Ji; Hsueh, Ying-Chih; Peng, Ching-Fang; Tang, Chao-Wei

    2016-10-27

    The lightweight aggregates used by the civil engineering market are sintered at a high temperature, about 1200 °C. In times of high energy prices and regulation of carbon dioxide emissions, lightweight aggregate products of the high-temperature process in sales marketing are not readily accepted. This study developed a sintered-type paper sludge lightweight aggregate. In order to reduce energy consumption, substitution of some reservoir sediment clay in paper sludge substitutes is to be expected. The study used two types of paper sludge (green clay paper sludge and paper pulp sludge). The sintering temperature was reduced effectively as the green clay paper sludge was substituted for some of the reservoir sediment clay, and the optimum substitute ranges of green clay paper sludge were 10%-50%. The optimum substitute ranges of the paper pulp sludge were 10%-40%. Test results show that the properties of aggregates have a particle density of 0.66-1.69 g/cm³, a water absorption of 5%-30%, and a loss on ignition of 10%-43%. The loss on ignition of aggregate became greater with the increase in paper sludge content. This means that the calorific value provided by the paper sludge will increase as paper sludge content increases. Paper sludge can therefore be considered a good material to provide heat energy for sintering lightweight aggregate.

  14. Cholesterol impairment contributes to neuroserpin aggregation

    Science.gov (United States)

    Giampietro, Costanza; Lionetti, Maria Chiara; Costantini, Giulio; Mutti, Federico; Zapperi, Stefano; La Porta, Caterina A. M.

    2017-01-01

    Intraneural accumulation of misfolded proteins is a common feature of several neurodegenerative pathologies including Alzheimer’s and Parkinson’s diseases, and Familial Encephalopathy with Neuroserpin Inclusion Bodies (FENIB). FENIB is a rare disease due to a point mutation in neuroserpin which accelerates protein aggregation in the endoplasmic reticulum (ER). Here we show that cholesterol depletion induced either by prolonged exposure to statins or by inhibiting the sterol reg-ulatory binding-element protein (SREBP) pathway also enhances aggregation of neuroserpin proteins. These findings can be explained considering a computational model of protein aggregation under non-equilibrium conditions, where a decrease in the rate of protein clearance improves aggregation. Decreasing cholesterol in cell membranes affects their biophysical properties, including their ability to form the vesicles needed for protein clearance, as we illustrate by a simple mathematical model. Taken together, these results suggest that cholesterol reduction induces neuroserpin aggregation, even in absence of specific neuroserpin mutations. The new mechanism we uncover could be relevant also for other neurodegenerative diseases associated with protein aggregation. PMID:28255164

  15. Growth hormone aggregates in the rat adenohypophysis

    Science.gov (United States)

    Farrington, M.; Hymer, W. C.

    1990-01-01

    Although it has been known for some time that GH aggregates are contained within the rat anterior pituitary gland, the role that they might play in pituitary function is unknown. The present study examines this issue using the technique of Western blotting, which permitted visualization of 11 GH variants with apparent mol wt ranging from 14-88K. Electroelution of the higher mol wt variants from gels followed by their chemical reduction with beta-mercaptoethanol increased GH immunoassayability by about 5-fold. With the blot procedure we found 1) that GH aggregates greater than 44K were associated with a 40,000 x g sedimentable fraction; 2) that GH aggregates were not present in glands from thyroidectomized rats, but were in glands from the thyroidectomized rats injected with T4; 3) that GH aggregates were uniquely associated with a heavily granulated somatotroph subpopulation isolated by density gradient centrifugation; and 4) that high mol wt GH forms were released from the dense somatotrophs in culture, since treatment of the culture medium with beta-mercaptoethanol increased GH immunoassayability by about 5-fold. Taken together, the results show that high mol wt GH aggregates are contained in secretory granules of certain somatotrophs and are also released in aggregate form from these cells in vitro.

  16. Influence of Phenylalanine on Carotenoid Aggregation

    Science.gov (United States)

    Lu, L.; Ni, X.; Luo, X.

    2015-01-01

    The carotenoids lutein and β-carotene form, in 1:1 ethanol-water mixtures H-aggregates, of different strengths. The effects of phenylalanine on these aggregates were recorded by UV-Vis absorption, steady-state fluorescence, and Raman spectra. The H-aggregate of lutein was characterized by a large 78 nm blue shift in the absorption spectra, confirming the strong coupling between hydroxyl groups of adjacent molecules. The 15 nm blue shift in the β-carotene mixture also indicates that it was assembled by weak coupling between polyenes. After adding phenylalanine, the reducing absorption strength of the aggregates of lutein and reappearance of vibrational substructure indicate that the hydroxyl and amino groups of phenylalanine may coordinate to lutein and disaggregate the H-aggregates. However, phenylalanine had no effect on aggregates of β-carotene. The Raman spectra show three bands of carotenoids whose intensities decreased with increasing phenylalanine concentration. The frequency of ν1 corresponding to the length of the conjugated region was more sensitive to the solution of lutein. This coordination of phenylalanine to lutein could increase the length of the conjugated region. In addition, phenylalanine significantly affected the excited electronic states of carotenoids, which were crucial in the energy transfer from carotenoids to chlorophyll a in vivo.

  17. Cholesterol impairment contributes to neuroserpin aggregation

    Science.gov (United States)

    Giampietro, Costanza; Lionetti, Maria Chiara; Costantini, Giulio; Mutti, Federico; Zapperi, Stefano; La Porta, Caterina A. M.

    2017-03-01

    Intraneural accumulation of misfolded proteins is a common feature of several neurodegenerative pathologies including Alzheimer’s and Parkinson’s diseases, and Familial Encephalopathy with Neuroserpin Inclusion Bodies (FENIB). FENIB is a rare disease due to a point mutation in neuroserpin which accelerates protein aggregation in the endoplasmic reticulum (ER). Here we show that cholesterol depletion induced either by prolonged exposure to statins or by inhibiting the sterol reg-ulatory binding-element protein (SREBP) pathway also enhances aggregation of neuroserpin proteins. These findings can be explained considering a computational model of protein aggregation under non-equilibrium conditions, where a decrease in the rate of protein clearance improves aggregation. Decreasing cholesterol in cell membranes affects their biophysical properties, including their ability to form the vesicles needed for protein clearance, as we illustrate by a simple mathematical model. Taken together, these results suggest that cholesterol reduction induces neuroserpin aggregation, even in absence of specific neuroserpin mutations. The new mechanism we uncover could be relevant also for other neurodegenerative diseases associated with protein aggregation.

  18. An Identity Based Aggregate Signature from Pairings

    Directory of Open Access Journals (Sweden)

    Yike Yu

    2011-04-01

    Full Text Available An aggregate signature is a useful digital signature that supports aggregation: Given n signatures on n distinct messages from n distinct users, aggregate signature scheme is possible to aggregate all these signature into a single short signature. This single signature, along with the n original messages will convince any verifier that the n users did indeed sign the n original messages respectively (i.e., for i=1,...,n user i signed message  mi. In this paper, we propose an identity based aggregate signature scheme which requires constant pairing operations in the verification and the size of aggregate signature is independent of the number of signers. We prove that the proposed signature scheme is secure against existential forgery under adaptively chosen message and identity attack in the random oracle model assuming the intractability of the computational Diffie-Hellman problem.

  19. Open heart surgery

    Science.gov (United States)

    Heart surgery - open ... lung machine is used in most cases during open heart surgery. While the surgeon works on the ... with these procedures, the surgeon may have to open the chest to do the surgery.

  20. The OpenPlanetary initiative

    Science.gov (United States)

    Manaud, Nicolas; Rossi, Angelo Pio; Hare, Trent; Aye, Michael; Galluzzi, Valentina; van Gasselt, Stephan; Martinez, Santa; McAuliffe, Jonathan; Million, Chase; Nass, Andrea; Zinzi, Angelo

    2016-10-01

    "Open" has become attached to several concepts: science, data, and software are some of the most obvious. It is already common practice within the planetary science community to share spacecraft missions data freely and openly [1]. However, this is not historically the case for software tools, source code, and derived data sets, which are often reproduced independently by multiple individuals and groups. Sharing data, tools and overall knowledge would increase scientific return and benefits [e.g. 2], and recent projects and initiatives are helping toward this goal [e.g. 3,4,5,6].OpenPlanetary is a bottom-up initiative to address the need of the planetary science community for sharing ideas and collaborating on common planetary research and data analysis problems, new challenges, and opportunities. It started from an initial participants effort to stay connected and share information related to and beyond the ESA's first Planetary GIS Workshop [7]. It then continued during the 2nd (US) Planetary Data Workshop [8], and aggregated more people.Our objective is to build an online distributed framework enabling open collaborations within the planetary science community. We aim to co-create, curate and publish resource materials and data sets; to organise online events, to support community-based projects development; and to offer a real-time communication channel at and between conferences and workshops.We will present our current framework and resources, developing projects and ideas, and solicit for feedback and participation. OpenPlanetary is intended for research and education professionals: scientists, engineers, designers, teachers and students, as well as the general public that includes enthusiasts and citizen scientists. All are welcome to join and contribute at openplanetary.co[1] International Planetary Data Alliance, planetarydata.org. [2] Nosek et al (2015), dx.doi.org/10.1126/science.aab2374. [3] Erard S. et al. (2016), EGU2016-17527. [4] Proposal for a PDS

  1. Apraxia of lid opening

    Directory of Open Access Journals (Sweden)

    Jebasingh Y

    2006-01-01

    Full Text Available Apraxia of lid opening is a condition where patients do not have ptosis but have difficulty in overcoming levator palpebrae inhibition. We report a patient who presented with difficulty in opening eyelids with out diurnal variation, ptosis or blepharospasm. The diagnosis of Apraxia of lid opening is confirmed by electro physiology. The possibility of apraxia of lid opening should be considered in patients who present with difficulty in opening eyes. Various causes of Apraxia of lid opening are discussed.

  2. Aggregation of Dodecyl 1-Pyrenylmethyl Ether and Its Application in Structure-Polarity Relations of Aggregates

    Institute of Scientific and Technical Information of China (English)

    SANG,Da-Yong; TIAN,Juan; JI,Guo-Zhen

    2006-01-01

    The aggregation behavior of dodecyl 1-pyrenylmethyl ether was studied in dioxane-water mixture solvents by fluorescence techniques. The labeled pyrenyl group was effective in monitoring the polarity change of its environment during aggregation processes. Based on the structural effects such as chain-length effect, self-coiling effect,and branch-group effect on the polarity of the probe environment, the structure features of aggregates were discussed and have been used to interpret the effect of the structural features on the aggregates formed by three cholesteryl esters and three long chain alkanes.

  3. Pore structure of natural and regenerated soil aggregates

    DEFF Research Database (Denmark)

    Naveed, Muhammad; Arthur, Emmanuel; de Jonge, Lis Wollesen

    2014-01-01

    of the soil type and organic matter amendment, and was vastly different from the state of natural aggregates. Aggregate porosity (> 30 Hm) was observed to be a good predictor for the mechanical properties of aggregates. In general, natural aggregates were stronger than lysimeter aggregates.......Quantitative characterization of aggregate pore structure can reveal the evolution of aggregates under different land use and management practices and their effects on soil processes and functions. Advances in X-ray Computed Tomography (CT) provide powerful means to conduct such characterization....... This study examined aggregate pore structure of three differently managed same textured Danish soils (mixed forage cropping, MFC; mixed cash cropping, MCC; cereal cash cropping, CCC) for (i) natural aggregates, and (ii) aggregates regenerated after 20 months of incubation. In total, 27 aggregates (8-16 mm...

  4. Upper Grades Ideas.

    Science.gov (United States)

    Classroom Computer Learning, 1983

    1983-01-01

    Offers such teaching activities as a one-line program contest, field trips, examining job openings in newspapers, and a writing activity speculating what would happen if robots did not follow Isaac Asimov's "Three Laws of Robotics." Includes "Logo Goes to High School" by E. Paul Goldenberg, discussing problem-solving tasks using Logo. (JN)

  5. Upper Grades Ideas.

    Science.gov (United States)

    Classroom Computer Learning, 1983

    1983-01-01

    Offers such teaching activities as a one-line program contest, field trips, examining job openings in newspapers, and a writing activity speculating what would happen if robots did not follow Isaac Asimov's "Three Laws of Robotics." Includes "Logo Goes to High School" by E. Paul Goldenberg, discussing problem-solving tasks…

  6. Upper Grades Ideas.

    Science.gov (United States)

    Classroom Computer Learning, 1983

    1983-01-01

    Offers such teaching activities as a one-line program contest, field trips, examining job openings in newspapers, and a writing activity speculating what would happen if robots did not follow Isaac Asimov's "Three Laws of Robotics." Includes "Logo Goes to High School" by E. Paul Goldenberg, discussing problem-solving tasks…

  7. Cumulative irritancy in the guinea pig from low grade irritant vehicles and the angry skin syndrome

    DEFF Research Database (Denmark)

    Andersen, Klaus Ejner; Maibach, H I

    1980-01-01

    A 4-week open cumulative irritancy test in guinea pigs discriminated between two low grade irritant vehicles, nonionic base (anhydrous) and hydrophilic ointment. The procedure might be useful as a predictive test for low grade irritants. The angry skin syndrome was established in the guinea pigs...

  8. Grade-Level Status Effects in Multiage Groupwork: The Lady Bountiful Syndrome.

    Science.gov (United States)

    Young, Allison J.; Boyle, Robert A.

    A study investigated whether grade-level status affects learning through cross-age activities. Data were collected through unstructured and open-ended audiotaped interviews with 11 pairs of students in a combined third- and fifth-grade class. Coding and analysis of data revealed seven themes related to students' perceptions of their interactions…

  9. Direct observation of electric field induced pattern formation and particle aggregation in ferrofluids

    Energy Technology Data Exchange (ETDEWEB)

    Rajnak, Michal; Kopcansky, Peter; Timko, Milan [Institute of Experimental Physics SAS, Watsonova 47, 04001 Košice (Slovakia); Petrenko, Viktor I. [Joint Institute for Nuclear Research, Joliot-Curie 6, 141980 Dubna, Moscow Region (Russian Federation); Kyiv Taras Shevchenko National University, Volodymyrska Street 64, Kyiv 01033 (Ukraine); Avdeev, Mikhail V. [Joint Institute for Nuclear Research, Joliot-Curie 6, 141980 Dubna, Moscow Region (Russian Federation); Ivankov, Olexandr I. [Joint Institute for Nuclear Research, Joliot-Curie 6, 141980 Dubna, Moscow Region (Russian Federation); Kyiv Taras Shevchenko National University, Volodymyrska Street 64, Kyiv 01033 (Ukraine); Moscow Institute of Physics and Technology, Institutskiy per. 9, Dolgoprudniy 141700 (Russian Federation); Feoktystov, Artem [Jülich Centre for Neutron Science (JCNS) at Heinz Maier-Leibnitz Zentrum (MLZ), Forschungszentrum Jülich GmbH, Lichtenbergstr. 1, 85747 Garching (Germany); Dolnik, Bystrik; Kurimsky, Juraj [Faculty of Electrical Engineering and Informatics, Technical University of Košice, Letná 9, 04200 Košice (Slovakia)

    2015-08-17

    Ferrofluids typically respond to magnetic fields and can be manipulated by external magnetic fields. Here, we report on formation of visually observable patterns in a diluted low-polarity ferrofluid exposed to external electric fields. This presents a specific type of ferrofluid structure driven by a combined effect of electrohydrodynamics and electrical body forces. The free charge and permittivity variation are considered to play a key role in the observed phenomenon. The corresponding changes in the ferrofluid structure have been found at nanoscale as well. By small-angle neutron scattering (SANS), we show that the magnetic nanoparticles aggregate in direct current (dc) electric field with a strong dependence on the field intensity. The anisotropic aggregates preferably orient in the direction of the applied electric field. Conducting SANS experiments with alternating current (ac) electric fields of various frequencies, we found a critical frequency triggering the aggregation process. Our experimental study could open future applications of ferrofluids based on insulating liquids.

  10. Mechanism by which an elevation of extracellular glucide concentration induces pigment aggregation in medaka melanophores.

    Science.gov (United States)

    Fujii, Ryozo; Goda, Makoto; Oshima, Noriko

    2002-09-15

    An increase in glucide concentration induces pigment aggregation in melanophores in the skin on scales isolated from the medaka, Oryzias latipes. In this study, hexoses (including the common D-isomers of glucose, galactose, fructose, and mannitol) were examined. Denervated melanophores were refractory to such stimuli. An alpha-adrenolytic agent, phentolamine, effectively blocked the responses of normally innervated melanophores. The pigment-aggregating action of glucide was inhibited by withdrawal of Ca(2+) and Mg(2+) ions from the medium. A specific blocker of voltage-dependent N-type Ca(2+) channels, the omega-conotoxin GVIA, also inhibited the glucide action. The conclusion derived is that an elevation of glucide levels acts to open Ca(2+) channels of presynaptic membranes of sympathetic postganglionic fibers, and the consequently released adrenergic transmitter acts on the effector cells to induce the aggregation of their pigmentary organelles. Copyright 2002 Wiley-Liss, Inc.

  11. Ordered visibility graph average aggregation operator: An application in produced water management

    Science.gov (United States)

    Jiang, Wen; Wei, Boya; Tang, Yongchuan; Zhou, Deyun

    2017-02-01

    Complex networks are widely used in modeling complex system. How to aggregate data in complex systems is still an open issue. In this paper, an ordered visibility graph average aggregation operator is proposed which is inspired by the complex network theory and Newton's law of universal gravitation. First of all, the argument values are ordered in descending order. Then a new support function is proposed to measure the relationship among values in a visibility graph. After that, a weighted network is constructed to determine the weight of each value. Compared with the other operators, the new operator fully takes into account not only the information of orders but also the correlation degree between the values. Finally, an application of produced water management is illustrated to show the efficiency of the proposed method. The new method provides a universal way to aggregate data in complex systems.

  12. 7 CFR 810.1404 - Grades and grade requirements for sorghum.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 7 2010-01-01 2010-01-01 false Grades and grade requirements for sorghum. 810.1404... OFFICIAL UNITED STATES STANDARDS FOR GRAIN United States Standards for Sorghum >grades and Grade Requirements § 810.1404 Grades and grade requirements for sorghum. Grading factors Grades U.S. Nos. 1 1 2 3...

  13. Effects of Long-Term Fertilization on Distribution of Organic Matters and Nitrogen in Cinnamon Soil Macro-Aggregates

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    Soil samples collected from a 25-year long-term fertilizer experiment carried out on the Earth-cumulic-Orthic Anthrosols in semi-humid farmland ecological system, were used to study the distribution of soil organic matters, total nitrogen, nitrate nitrogen, and ammoniate nitrogen in different grades of soil macro-aggregates in order to study the effects of long-term application of organic manures in combination with chemical fertilizers. It is showed that the percentage of mass of the soil macro-aggregates with long-term application of fertilizers with sizes of 5-2 mm is increased compared with that of the samples with no fertilizer. It is easier to form lager size soil macro-aggregates by the long-term application of organic manures in combination with chemical fertilizers. The contents of organic matters, total nitrogen and nitrate nitrogen are all higher after treatments with different combinations of fertilizers, while there is a little effect on the contents of ammoniate nitrogen. The contents of organic matters, total nitrogen in the grades of soil macro-aggregates from the plough layers of the treated farmland exhibited significant difference. Moreover, the contents of organic matters and total nitrogen in the soil macro-aggregates with the size of 1-0.25 mm is the highest in all treated soil samples. The contents of nitrate nitrogen in soil macro-aggregates increased with the increasing of soil macro-aggregate size except those applied with chemical fertilizer and lower amount of corn stover. The results of correlation analysis revealed that there exists a significantly positive correlation between the percentage of mass of soil macro-aggregates with the size of 5-2 mm and the contents of organic matters, total nitrogen and nitrate nitrogen in the soil samples. However, the correlation between the percentage of mass of soil macro-aggregates with the size of 1-0.25 mm and the contents of total nitrogen and nitrate nitrogen is significantly negative. The

  14. Regulated protein aggregation: stress granules and neurodegeneration

    Directory of Open Access Journals (Sweden)

    Wolozin Benjamin

    2012-11-01

    Full Text Available Abstract The protein aggregation that occurs in neurodegenerative diseases is classically thought to occur as an undesirable, nonfunctional byproduct of protein misfolding. This model contrasts with the biology of RNA binding proteins, many of which are linked to neurodegenerative diseases. RNA binding proteins use protein aggregation as part of a normal regulated, physiological mechanism controlling protein synthesis. The process of regulated protein aggregation is most evident in formation of stress granules. Stress granules assemble when RNA binding proteins aggregate through their glycine rich domains. Stress granules function to sequester, silence and/or degrade RNA transcripts as part of a mechanism that adapts patterns of local RNA translation to facilitate the stress response. Aggregation of RNA binding proteins is reversible and is tightly regulated through pathways, such as phosphorylation of elongation initiation factor 2α. Microtubule associated protein tau also appears to regulate stress granule formation. Conversely, stress granule formation stimulates pathological changes associated with tau. In this review, I propose that the aggregation of many pathological, intracellular proteins, including TDP-43, FUS or tau, proceeds through the stress granule pathway. Mutations in genes coding for stress granule associated proteins or prolonged physiological stress, lead to enhanced stress granule formation, which accelerates the pathophysiology of protein aggregation in neurodegenerative diseases. Over-active stress granule formation could act to sequester functional RNA binding proteins and/or interfere with mRNA transport and translation, each of which might potentiate neurodegeneration. The reversibility of the stress granule pathway also offers novel opportunities to stimulate endogenous biochemical pathways to disaggregate these pathological stress granules, and perhaps delay the progression of disease.

  15. A Novel Method to Quantify Soil Aggregate Stability by Measuring Aggregate Bond Energies

    Science.gov (United States)

    Efrat, Rachel; Rawlins, Barry G.; Quinton, John N.; Watts, Chris W.; Whitmore, Andy P.

    2016-04-01

    Soil aggregate stability is a key indicator of soil quality because it controls physical, biological and chemical functions important in cultivated soils. Micro-aggregates are responsible for the long term sequestration of carbon in soil, therefore determine soils role in the carbon cycle. It is thus vital that techniques to measure aggregate stability are accurate, consistent and reliable, in order to appropriately manage and monitor soil quality, and to develop our understanding and estimates of soil as a carbon store to appropriately incorporate in carbon cycle models. Practices used to assess the stability of aggregates vary in sample preparation, operational technique and unit of results. They use proxies and lack quantification. Conflicting results are therefore drawn between projects that do not provide methodological or resultant comparability. Typical modern stability tests suspend aggregates in water and monitor fragmentation upon exposure to an un-quantified amount of ultrasonic energy, utilising a laser granulometer to measure the change in mean weight diameter. In this project a novel approach has been developed based on that of Zhu et al., (2009), to accurately quantify the stability of aggregates by specifically measuring their bond energies. The bond energies are measured operating a combination of calorimetry and a high powered ultrasonic probe, with computable output function. Temperature change during sonication is monitored by an array of probes which enables calculation of the energy spent heating the system (Ph). Our novel technique suspends aggregates in heavy liquid lithium heteropolytungstate, as opposed to water, to avoid exposing aggregates to an immeasurable disruptive energy source, due to cavitation, collisions and clay swelling. Mean weight diameter is measured by a laser granulometer to monitor aggregate breakdown after successive periods of calculated ultrasonic energy input (Pi), until complete dispersion is achieved and bond

  16. Engineering graded tissue interfaces.

    Science.gov (United States)

    Phillips, Jennifer E; Burns, Kellie L; Le Doux, Joseph M; Guldberg, Robert E; García, Andrés J

    2008-08-26

    Interfacial zones between tissues provide specialized, transitional junctions central to normal tissue function. Regenerative medicine strategies focused on multiple cell types and/or bi/tri-layered scaffolds do not provide continuously graded interfaces, severely limiting the integration and biological performance of engineered tissue substitutes. Inspired by the bone-soft tissue interface, we describe a biomaterial-mediated gene transfer strategy for spatially regulated genetic modification and differentiation of primary dermal fibroblasts within tissue-engineered constructs. We demonstrate that zonal organization of osteoblastic and fibroblastic cellular phenotypes can be engineered by a simple, one-step seeding of fibroblasts onto scaffolds containing a spatial distribution of retrovirus encoding the osteogenic transcription factor Runx2/Cbfa1. Gradients of immobilized retrovirus, achieved via deposition of controlled poly(L-lysine) densities, resulted in spatial patterns of transcription factor expression, osteoblastic differentiation, and mineralized matrix deposition. Notably, this graded distribution of mineral deposition and mechanical properties was maintained when implanted in vivo in an ectopic site. Development of this facile and robust strategy is significant toward the regeneration of continuous interfacial zones that mimic the cellular and microstructural characteristics of native tissue.

  17. Functionality and versatility of aggregation-induced emission luminogens

    Science.gov (United States)

    Feng, Guangxue; Kwok, Ryan T. K.; Tang, Ben Zhong; Liu, Bin

    2017-06-01

    Breakthrough innovations in light-emitting materials have opened new exciting avenues for science and technology over the last few decades. Aggregation-induced emission (AIE) represents one of such innovations. It refers to a unique light-emitting phenomenon, in which luminescent materials that are non-emissive in molecular state can be induced to emit efficiently in aggregated state. The design and development of AIE luminogens (AIEgens) have overcome technical and fundamental limitations that exist in conventional light-emitting materials, and thus generate great opportunities for various applications. In this review, we aim to introduce the wonderful world of AIE to scientists from different disciplines by summarizing the recent progress made in this exciting research field. The mechanistic analyses and the working principles of the AIE processes are first elaborated, which reveal the restriction of intramolecular motions as the main cause for the AIE effect. The different molecular engineering strategies for the design of new AIEgens are subsequently discussed with examples of various AIEgen systems. The recent high-tech applications of AIEgens as optoelectronic materials, chemical sensors, and biomedical probes are presented and discussed. We hope that this review will stimulate more research interest from physics, chemistry, life science, and biomedical fields to this wonderland of AIE.

  18. Spatial Prediction of Soil Aggregate Stability and Aggregate-Associated Organic Carbon Content at the Catchment Scale Using Geostatistical Techniques

    Institute of Scientific and Technical Information of China (English)

    J.MOHAMMADI; M.H.MOTAGHIAN

    2011-01-01

    The association of organic carbon with secondary parzicles (aggregates) results in its storage and retention in soil. A study was carried out at a catchment covering about 92 km2 to predict spatial variability of soil water-stable aggregates (WSA), mean weight diameter (MWD) of aggregates and organic carbon (OC) content in macro- (> 2 mm), meso- (1-2 mm), and micro-aggregate (< 1 mm) fractions, using geostatistical methods. One hundred and eleven soil samples were c(o)llected at the 0-10 cm depth and fractionated into macro-, meso-, and micro-aggregates by wet sieving. The OC content was determined for each fraction. A greater percentage of water-stable aggregates was found for micro-aggregates, followed by meso-aggregates. Aggregate OC content was greatest in meso-aggregates (9 g kg-1), followed by micro-aggregates (7 g kg-1), while the least OC content was found in macro-aggregates (3 g kg-1). Although a significart effect (P = 0.000) of aggregate size on aggregate OC content was found, however, our findings did not support the model of aggregate hierarchy.Land use had a significant effect (P = 0.073) on aggregate OC content. The coefficients of variation (CVs) for OC contents associated with each aggregate fraction indicated macro-aggregates as the most variable (CV = 71%). Among the aggregate fractions, the micro-aggregate fraction had a lower CV value of 27%. The mean content of WSA ranged from 15% for macro-aggregates to 84% for micro-aggregates. Geostatistical analysis showed that the measured soil variables exhibited differences in their spatial patterns in both magnitude and space at each aggregate size fraction. The relative nugget variance for most aggregate-associated properties was lower than 45%. The range value for the variogram of water-stable aggregates was almost similar (about 3 km) for the three studied aggregate size classes. The range value for the variogram of aggregate-associated OC contents ranged from about 3 km for macro-aggregates

  19. Copper in Alzheimer's disease: Implications in amyloid aggregation and neurotoxicity

    Science.gov (United States)

    Gamez, Patrick; Caballero, Ana B.

    2015-09-01

    The relationship of copper dyshomeostasis with neurodegenerative diseases has become evident in the last years. Because of the major role that this metal ion plays in biological processes, most of which being located in the brain, it is not surprising that changes in its distribution are closely related with the advent of neurodegenerative disorders such as Alzheimer's disease (AD). An increasing number of works have dealt with this subject in the last years, and opened an intense debate in some points while raising new questions that still remain unanswered. This revision work puts together and discusses the latest findings and insights on how copper ions are involved in AD progression, including its interaction with Aβ and its consequently induced aggregation.

  20. Solving network design problems via decomposition, aggregation and approximation

    CERN Document Server

    Bärmann, Andreas

    2016-01-01

    Andreas Bärmann develops novel approaches for the solution of network design problems as they arise in various contexts of applied optimization. At the example of an optimal expansion of the German railway network until 2030, the author derives a tailor-made decomposition technique for multi-period network design problems. Next, he develops a general framework for the solution of network design problems via aggregation of the underlying graph structure. This approach is shown to save much computation time as compared to standard techniques. Finally, the author devises a modelling framework for the approximation of the robust counterpart under ellipsoidal uncertainty, an often-studied case in the literature. Each of these three approaches opens up a fascinating branch of research which promises a better theoretical understanding of the problem and an increasing range of solvable application settings at the same time. Contents Decomposition for Multi-Period Network Design Solving Network Design Problems via Ag...

  1. Layer aggregation and reducibility of multilayer interconnected networks

    CERN Document Server

    De Domenico, M; Arenas, A; Latora, V

    2014-01-01

    Many complex systems can be represented as networks composed by distinct layers, interacting and depending on each others. For example, in biology, a good description of the full protein-protein interactome requires, for some organisms, up to seven distinct network layers, with thousands of protein-protein interactions each. A fundamental open question is then how much information is really necessary to accurately represent the structure of a multilayer complex system, and if and when some of the layers can indeed be aggregated. Here we introduce a method, based on information theory, to reduce the number of layers in multilayer networks, while minimizing information loss. We validate our approach on a set of synthetic benchmarks, and prove its applicability to an extended data set of protein-genetic interactions, showing cases where a strong reduction is possible and cases where it is not. Using this method we can describe complex systems with an optimal trade--off between accuracy and complexity.

  2. Aspects Concerning the Use of Recycled Concrete Aggregates

    Science.gov (United States)

    Robu, I.; Mazilu, C.; Deju, R.

    2016-11-01

    Natural aggregates (gravel and crushed) are essential non-renewable resources which are used for infrastructure works and civil engineering. Using recycled concrete aggregates (RCA) is a matter of high priority in the construction industry worldwide. This paper presents a study on the use of recycled aggregates, from a concrete of specified class, to acquire new cement concrete with different percentages of recycled aggregates.

  3. Metaconcrete: Engineered aggregates for enhanced dynamic performance

    Science.gov (United States)

    Mitchell, Stephanie J.

    This work presents the development and investigation of a new type of concrete for the attenuation of waves induced by dynamic excitation. Recent progress in the field of metamaterials science has led to a range of novel composites which display unusual properties when interacting with electromagnetic, acoustic, and elastic waves. A new structural metamaterial with enhanced properties for dynamic loading applications is presented, which is named metaconcrete. In this new composite material the standard stone and gravel aggregates of regular concrete are replaced with spherical engineered inclusions. Each metaconcrete aggregate has a layered structure, consisting of a heavy core and a thin compliant outer coating. This structure allows for resonance at or near the eigenfrequencies of the inclusions, and the aggregates can be tuned so that resonant oscillations will be activated by particular frequencies of an applied dynamic loading. The activation of resonance within the aggregates causes the overall system to exhibit negative effective mass, which leads to attenuation of the applied wave motion. To investigate the behavior of metaconcrete slabs under a variety of different loading conditions a finite element slab model containing a periodic array of aggregates is utilized. The frequency dependent nature of metaconcrete is investigated by considering the transmission of wave energy through a slab, which indicates the presence of large attenuation bands near the resonant frequencies of the aggregates. Applying a blast wave loading to both an elastic slab and a slab model that incorporates the fracture characteristics of the mortar matrix reveals that a significant portion of the supplied energy can be absorbed by aggregates which are activated by the chosen blast wave profile. The transfer of energy from the mortar matrix to the metaconcrete aggregates leads to a significant reduction in the maximum longitudinal stress, greatly improving the ability of the material

  4. Structure and aggregation in model tetramethylurea solutions

    Energy Technology Data Exchange (ETDEWEB)

    Gupta, Rini; Patey, G. N., E-mail: patey@chem.ubc.ca [Department of Chemistry, University of British Columbia, Vancouver, British Columbia V6T 1Z1 (Canada)

    2014-08-14

    The structure of model aqueous tetramethylurea (TMU) solutions is investigated employing large-scale (32 000, 64 000 particles) molecular dynamics simulations. Results are reported for TMU mole fractions, X{sub t}, ranging from infinite dilution up to 0.07, and for two temperatures, 300 and 330 K. Two existing force fields for TMU-water solutions are considered. These are the GROMOS 53A6 united-atom TMU model combined with SPC/E water [TMU(GROMOS-UA)/W(SPC/E)], and the more frequently employed AMBER03 all-atom force field for TMU combined with the TIP3P water model [TMU(AMBER-AA)/W(TIP3P)]. It is shown that TMU has a tendency towards aggregation for both models considered, but the tendency is significantly stronger for the [TMU(AMBER-AA)/W(TIP3P)] force field. For this model signs of aggregation are detected at X{sub t} = 0.005, aggregation is a well established feature of the solution at X{sub t} = 0.02, and the aggregates increase further in size with increasing concentration. This is in agreement with at least some experimental studies, which report signals of aggregation in the low concentration regime. The TMU aggregates exhibit little structure and are simply loosely ordered, TMU-rich regions of solution. The [TMU(GROMOS-UA)/W(SPC/E)] model shows strong signs of aggregation only at higher concentrations (X{sub t} ≳ 0.04), and the aggregates appear more loosely ordered, and less well-defined than those occurring in the [TMU(AMBER-AA)/W(TIP3P)] system. For both models, TMU aggregation increases when the temperature is increased from 300 to 330 K, consistent with an underlying entropy driven, hydrophobic interaction mechanism. At X{sub t} = 0.07, the extra-molecular correlation length expected for microheterogeneous solutions has become comparable with the size of the simulation cell for both models considered, indicating that even the systems simulated here are sufficiently large only at low concentrations.

  5. Glaucoma, Open-Angle

    Science.gov (United States)

    ... Programs Home > Statistics and Data > Glaucoma, Open-angle Glaucoma, Open-angle Open-angle Glaucoma Defined In open-angle glaucoma, the fluid passes ... 2010 2010 U.S. Age-Specific Prevalence Rates for Glaucoma by Age and Race/Ethnicity The prevalence of ...

  6. JISC Open Access Briefing Paper

    OpenAIRE

    Swan, Alma

    2005-01-01

    What Open Access is. What Open Access is not. How is Open Access provided? Open Access archives or repositories. Open Access journals. Why should authors provide Open Access to their work? Further information and resources

  7. JISC Open Access Briefing Paper

    OpenAIRE

    Swan, Alma

    2005-01-01

    What Open Access is. What Open Access is not. How is Open Access provided? Open Access archives or repositories. Open Access journals. Why should authors provide Open Access to their work? Further information and resources

  8. Aggregate Particles in the Plumes of Enceladus

    CERN Document Server

    Gao, Peter; Zhang, Xi; Ingersoll, Andrew P

    2015-01-01

    Estimates of the total particulate mass of the plumes of Enceladus are important to constrain theories of particle formation and transport at the surface and interior of the satellite. We revisit the calculations of Ingersoll and Ewald (2011), who estimated the particulate mass of the Enceladus plumes from strongly forward scattered light in Cassini ISS images. We model the plume as a combination of spherical particles and irregular aggregates resulting from the coagulation of spherical monomers, the latter of which allows for plumes of lower particulate mass. Though a continuum of solutions are permitted by the model, the best fits to the ISS data consist either of low mass plumes composed entirely of small aggregates or high mass plumes composed of large aggregates and spheres. The high mass plumes can be divided into a population of large aggregates with total particulate mass of 116 +/- 12 X 10^3 kg, and a mixed population of spheres and aggregates consisting of a few large monomers that has a total plume...

  9. Soil aggregation under different management systems

    Directory of Open Access Journals (Sweden)

    Cibele Mascioli Rebello Portella

    2012-12-01

    Full Text Available Considering that the soil aggregation reflects the interaction of chemical, physical and biological soil factors, the aim of this study was evaluate alterations in aggregation, in an Oxisol under no-tillage (NT and conventional tillage (CT, since over 20 years, using as reference a native forest soil in natural state. After analysis of the soil profile (cultural profile in areas under forest management, samples were collected from the layers 0-5, 5-10, 10-20 and 20-40 cm, with six repetitions. These samples were analyzed for the aggregate stability index (ASI, mean weighted diameter (MWD, mean geometric diameter (MGD in the classes > 8, 8-4, 4-2, 2-1, 1-0.5, 0.5-0.25, and < 0.25 mm, and for physical properties (soil texture, water dispersible clay (WDC, flocculation index (FI and bulk density (Bd and chemical properties (total organic carbon - COT, total nitrogen - N, exchangeable calcium - Ca2+, and pH. The results indicated that more intense soil preparation (M < NT < PC resulted in a decrease in soil stability, confirmed by all stability indicators analyzed: MWD, MGD, ASI, aggregate class distribution, WDC and FI, indicating the validity of these indicators in aggregation analyses of the studied soil.

  10. Aggregates in monoclonal antibody manufacturing processes.

    Science.gov (United States)

    Vázquez-Rey, María; Lang, Dietmar A

    2011-07-01

    Monoclonal antibodies have proved to be a highly successful class of therapeutic products. Large-scale manufacturing of pharmaceutical antibodies is a complex activity that requires considerable effort in both process and analytical development. If a therapeutic protein cannot be stabilized adequately, it will lose partially or totally its therapeutic properties or even cause immunogenic reactions thus potentially further endangering the patients' health. The phenomenon of protein aggregation is a common issue that compromises the quality, safety, and efficacy of antibodies and can happen at different steps of the manufacturing process, including fermentation, purification, final formulation, and storage. Aggregate levels in drug substance and final drug product are a key factor when assessing quality attributes of the molecule, since aggregation might impact biological activity of the biopharmaceutical. In this review it is analyzed how aggregates are formed during monoclonal antibody industrial production, why they have to be removed and the manufacturing process steps that are designed to either minimize or remove aggregates in the final product. Copyright © 2011 Wiley Periodicals, Inc.

  11. Aggregation Pheromone System: A Real-parameter Optimization Algorithm using Aggregation Pheromones as the Base Metaphor

    Science.gov (United States)

    Tsutsui, Shigeyosi

    This paper proposes an aggregation pheromone system (APS) for solving real-parameter optimization problems using the collective behavior of individuals which communicate using aggregation pheromones. APS was tested on several test functions used in evolutionary computation. The results showed APS could solve real-parameter optimization problems fairly well. The sensitivity analysis of control parameters of APS is also studied.

  12. SENSOR indicator framework, and methods for aggregation/dis-aggregation - a guideline

    DEFF Research Database (Denmark)

    Frederiksen, P.; Kristensen, P.; Briquel, V.

    This report collects three guideline contributions to Sensor: the development and proposal of an indicator framework for sustainability impact assessment and criteria for indicator selection, an assessment of international indicator sets for identification of potential indicators for SENSOR impact...... issues, and a description of problems and methodologies for aggregation and dis-aggregation of data and indicators....

  13. Soil aggregation and aggregating agents as affected by long term contrasting management of an Anthrosol

    Science.gov (United States)

    Zhang, Shulan; Wang, Renjie; Yang, Xueyun; Sun, Benhua; Li, Qinghui

    2016-12-01

    Soil aggregation was studied in a 21-year experiment conducted on an Anthrosol. The soil management regimes consisted of cropland abandonment, bare fallow without vegetation and cropping system. The cropping system was combined with the following nutrient management treatments: control (CONTROL, no nutrient input); nitrogen, phosphorus and potassium (NPK); straw plus NPK (SNPK); and manure (M) plus NPK (MNPK). Compared with the CONTROL treatment, the abandonment treatment significantly increased the formation of large soil macroaggregates (>2 mm) and consequently improved the stability of aggregates in the surface soil layer due to enhancement of hyphal length and of soil organic matter content. However, in response to long-term bare fallow treatment aggregate stability was low, as were the levels of aggregating agents. Long term fertilization significantly redistributed macroaggregates; this could be mainly ascribed to soil organic matter contributing to the formation of 0.5–2 mm classes of aggregates and a decrease in the formation of the >2 mm class of aggregates, especially in the MNPK treatment. Overall, hyphae represented a major aggregating agent in both of the systems tested, while soil organic compounds played significantly different roles in stabilizing aggregates in Anthrosol when the cropping system and the soil management regimes were compared.

  14. Multipole Expansions of Aggregate Charge: How Far to Go?

    CERN Document Server

    Matthews, Lorin S; Hyde, Truell W

    2015-01-01

    Aggregates immersed in a plasma or radiative environment will have charge distributed over their extended surface. Previous studies have modeled the aggregate charge using the monopole and dipole terms of a multipole expansion, with results indicating that the dipole-dipole interactions play an important role in increasing the aggregation rate and altering the morphology of the resultant aggregates. This study examines the effect that including the quadrupole terms has on the dynamics of aggregates interacting with each other and the confining electric fields in laboratory experiments. Results are compared to modeling aggregates as a collection of point charges located at the center of each spherical monomer comprising the aggregate.

  15. OpenGL Insights

    CERN Document Server

    Cozzi, Patrick

    2012-01-01

    Get Real-World Insight from Experienced Professionals in the OpenGL Community With OpenGL, OpenGL ES, and WebGL, real-time rendering is becoming available everywhere, from AAA games to mobile phones to web pages. Assembling contributions from experienced developers, vendors, researchers, and educators, OpenGL Insights presents real-world techniques for intermediate and advanced OpenGL, OpenGL ES, and WebGL developers. Go Beyond the Basics The book thoroughly covers a range of topics, including OpenGL 4.2 and recent extensions. It explains how to optimize for mobile devices, explores the design

  16. Dimensions of Openness

    DEFF Research Database (Denmark)

    Dalsgaard, Christian; Thestrup, Klaus

    2015-01-01

    as a matter of engaging educational activities in sociocultural practices of a surrounding society. Openness is not only a matter of opening up the existing, but of developing new educational practices that interact with society. The paper outlines three pedagogical dimensions of openness: transparency...... practices. Openness as joint engagement in the world aims at establishing interdependent collaborative relationships between educational institutions and external practices. To achieve these dimensions of openness, educational activities need to change and move beyond the course as the main format...... for openness. With examples from a university case, the paper discusses how alternative pedagogical formats and educational technologies can support the three dimensions of openness....

  17. Association of polyalanine and polyglutamine coiled coils mediates expansion disease-related protein aggregation and dysfunction.

    Science.gov (United States)

    Pelassa, Ilaria; Corà, Davide; Cesano, Federico; Monje, Francisco J; Montarolo, Pier Giorgio; Fiumara, Ferdinando

    2014-07-01

    The expansion of homopolymeric glutamine (polyQ) or alanine (polyA) repeats in certain proteins owing to genetic mutations induces protein aggregation and toxicity, causing at least 18 human diseases. PolyQ and polyA repeats can also associate in the same proteins, but the general extent of their association in proteomes is unknown. Furthermore, the structural mechanisms by which their expansion causes disease are not well understood, and these repeats are generally thought to misfold upon expansion into aggregation-prone β-sheet structures like amyloids. However, recent evidence indicates a critical role for coiled-coil (CC) structures in triggering aggregation and toxicity of polyQ-expanded proteins, raising the possibility that polyA repeats may as well form these structures, by themselves or in association with polyQ. We found through bioinformatics screenings that polyA, polyQ and polyQA repeats have a phylogenetically graded association in human and non-human proteomes and associate/overlap with CC domains. Circular dichroism and cross-linking experiments revealed that polyA repeats can form--alone or with polyQ and polyQA--CC structures that increase in stability with polyA length, forming higher-order multimers and polymers in vitro. Using structure-guided mutagenesis, we studied the relevance of polyA CCs to the in vivo aggregation and toxicity of RUNX2--a polyQ/polyA protein associated with cleidocranial dysplasia upon polyA expansion--and found that the stability of its polyQ/polyA CC controls its aggregation, localization and toxicity. These findings indicate that, like polyQ, polyA repeats form CC structures that can trigger protein aggregation and toxicity upon expansion in human genetic diseases. © The Author 2014. Published by Oxford University Press.

  18. Cellular strategies for regulating functional and nonfunctional protein aggregation.

    Science.gov (United States)

    Gsponer, Jörg; Babu, M Madan

    2012-11-29

    Growing evidence suggests that aggregation-prone proteins are both harmful and functional for a cell. How do cellular systems balance the detrimental and beneficial effect of protein aggregation? We reveal that aggregation-prone proteins are subject to differential transcriptional, translational, and degradation control compared to nonaggregation-prone proteins, which leads to their decreased synthesis, low abundance, and high turnover. Genetic modulators that enhance the aggregation phenotype are enriched in genes that influence expression homeostasis. Moreover, genes encoding aggregation-prone proteins are more likely to be harmful when overexpressed. The trends are evolutionarily conserved and suggest a strategy whereby cellular mechanisms specifically modulate the availability of aggregation-prone proteins to (1) keep concentrations below the critical ones required for aggregation and (2) shift the equilibrium between the monomeric and oligomeric/aggregate form, as explained by Le Chatelier's principle. This strategy may prevent formation of undesirable aggregates and keep functional assemblies/aggregates under control.

  19. Web Data Aggregation in MOLAP: Approach, Language, and Implementation

    Institute of Scientific and Technical Information of China (English)

    ZHU Yan; TANG Hui-jia; MA Yong-qiang

    2007-01-01

    This paper investigates the Web data aggregation issues in multidimensional on-line analytical processing (MOLAP) and presents a rule-driven aggregation approach. The core of the approach is defining aggregate rules. To define the rules for reading warehouse data and computing aggregates, a rule definition language - array aggregation language (AAL) is developed. This language treats an array as a function from indexes to values and provides syntax and semantics based on monads. External functions can be called in aggregation rules to specify array reading, writing, and aggregating. Based on the features of AAL, array operations are unified as function operations, which can be easily expressed and automatically evaluated. To implement the aggregation approach, a processor for computing aggregates over the base cube and for materializing them in the data warehouse is built, and the component structure and working principle of the aggregation processor are introduced.

  20. Tetranuclear zinc(II-oxy (benzothiazole-2-thiolate aggregate and copper(I phenylthiolate aggregate

    Directory of Open Access Journals (Sweden)

    Abir Goswami

    2015-12-01

    Full Text Available A tetranuclear zinc-oxy (benzothiazole-2-thiolate aggregate whose structure has a C3-axis passing through ZnO unit relating three other zinc ions and a tetranuclear copper(I phenylthiolate aggregate having each thiphenolate ligand bridging three copper ions are reported. These aggregates were prepared by hydrothermal reactions of 2,2′-dithiobis-(benzothiazole with zinc nitrate or copper(I iodide, respectively. The reaction of zinc nitrate passed through in situ abstraction of a oxy ligand from moisture to form a Zn4O core holding six 2-benzothiazolethiolate ligands, and during the formation of the aggregate, cleavage of S–S bond of 2,2′-dithiobis-(benzothiazole took place. Whereas, an aggregate formed by self-assembling of copper(I phenylthiolate was formed after extensive degradation of 2,2′-dithiobis-(benzothiazole during solvothermal reaction.

  1. Fracture resistance on aggregate bridging crack in concrete

    Institute of Scientific and Technical Information of China (English)

    ZHANG Xiufang; XU Shilang

    2007-01-01

    Fracture toughening exhibited in quasi-brittle materials such as concrete is often mainly related to the action of aggregate bridging,which leads to the presence of a fracture process zone ahead of stress-free cracks in such materials.In this investigation,the fracture resistance induced by aggregate bridging,denoted by GI-bridging,is the primary focus.In order to quantitatively determine it,a general analytical formula is firstly developed,based on the definition of fracture energy by Hillerborg.After this,we further present the calculated procedures of determining this fracture resistance from the recorded load vs.crack opening displacement curve.Then,both numerical simulations and fracture experiments are performed on concrete three-point bending beams.Utilizing the obtained load against crack opening displacement curve,the value of GI-bridging at any crack extension as well as the change of GI-bridging with the crack extension is examined.It is found that GI-bridging will firstly increase with the development of crack and then stay constant once the initial crack tip opening displacement reaches the characteristic crack opening displacement w0.The effects of material strength and specimen depth on this fracture resistance are also investigated.The results reveal that the values of GI-bridging of different specimens at any crack propagation are strongly associated with the values of fracture energy of specimens.If the values of fracture energy between different specimens are comparable,the differences between GI-bridging are ignored.Instead,if values of fracture energy are different,the GI-bridging will be different.This shows that for specimens with different strengths,GI-bridging will change greatly whereas for specimens that are different in depth,whether GI-bridging exhibits size effect depends on whether the fracture energy of specimens considered in the calculation of GI-bridging is assumed to be a size-dependent material parameter.

  2. Corrosion Behavior of Steel Reinforcement in Concrete with Recycled Aggregates, Fly Ash and Spent Cracking Catalyst

    Directory of Open Access Journals (Sweden)

    Hebé Gurdián

    2014-04-01

    Full Text Available The main strategy to reduce the environmental impact of the concrete industry is to reuse the waste materials. This research has considered the combination of cement replacement by industrial by-products, and natural coarse aggregate substitution by recycled aggregate. The aim is to evaluate the behavior of concretes with a reduced impact on the environment by replacing a 50% of cement by industrial by-products (15% of spent fluid catalytic cracking catalyst and 35% of fly ash and a 100% of natural coarse aggregate by recycled aggregate. The concretes prepared according to these considerations have been tested in terms of mechanical strengths and the protection offered against steel reinforcement corrosion under carbonation attack and chloride-contaminated environments. The proposed concrete combinations reduced the mechanical performance of concretes in terms of elastic modulus, compressive strength, and flexural strength. In addition, an increase in open porosity due to the presence of recycled aggregate was observed, which is coherent with the changes observed in mechanical tests. Regarding corrosion tests, no significant differences were observed in the case of the resistance of these types of concretes under a natural chloride attack. In the case of carbonation attack, although all concretes did not stand the highly aggressive conditions, those concretes with cement replacement behaved worse than Portland cement concretes.

  3. The evolving Gleason grading system.

    Science.gov (United States)

    Chen, Ni; Zhou, Qiao

    2016-02-01

    The Gleason grading system for prostate adenocarcinoma has evolved from its original scheme established in the 1960s-1970s, to a significantly modified system after two major consensus meetings conducted by the International Society of Urologic Pathology (ISUP) in 2005 and 2014, respectively. The Gleason grading system has been incorporated into the WHO classification of prostate cancer, the AJCC/UICC staging system, and the NCCN guidelines as one of the key factors in treatment decision. Both pathologists and clinicians need to fully understand the principles and practice of this grading system. We here briefly review the historical aspects of the original scheme and the recent developments of Gleason grading system, focusing on major changes over the years that resulted in the modern Gleason grading system, which has led to a new "Grade Group" system proposed by the 2014 ISUP consensus, and adopted by the 2016 WHO classification of tumours of the prostate.

  4. An ROLAP Aggregation Algorithm with the Rules Being Specified

    Science.gov (United States)

    Zhengqiu, Weng; Tai, Kuang; Lina, Zhang

    This paper introduces the base theory of data warehouse and ROLAP, and presents a new kind of ROLAP aggregation algorithm, which has calculation algorithms. It covers the shortage of low accuracy of traditional aggregation algorithm that aggregates only by addition. The ROLAP aggregation with calculation algorithm which can aggregate according to business rules improves accuracy. And key designs and procedures are presented. Compared with the traditional method, its efficiency is displayed in an experiment.

  5. Aggregate ranking of the world's leading universities

    Directory of Open Access Journals (Sweden)

    Vladimir M. Moskovkin

    2015-06-01

    Full Text Available The paper presents a methodology for calculating the aggregate global university ranking (Aggregated Global University Ranking, or AGUR, which consists of an automated presentation of the comparable lists of names for different universities from particular global university rankings (using Machine Learning and Mining Data algorithms and a simple procedure of aggregating particular global university rankings (summing up the university ranking positions from different particular rankings and their subsequent ranking. The second procedure makes it possible to bring lists of universities from particular rankings, which are nonidentical by length, to one size. The paper includes a sample AGUR for six particular global university rankings as of 2013, as well as cross-correlation matrices and intersection matrices for AGUR for 2011-2013, all created by means of using the Python-based software.

  6. Inflammation Induces TDP-43 Mislocalization and Aggregation.

    Directory of Open Access Journals (Sweden)

    Ana Sofia Correia

    Full Text Available TAR DNA-binding protein 43 (TDP-43 is a major component in aggregates of ubiquitinated proteins in amyotrophic lateral sclerosis (ALS and frontotemporal lobar degeneration (FTLD. Here we report that lipopolysaccharide (LPS-induced inflammation can promote TDP-43 mislocalization and aggregation. In culture, microglia and astrocytes exhibited TDP-43 mislocalization after exposure to LPS. Likewise, treatment of the motoneuron-like NSC-34 cells with TNF-alpha (TNF-α increased the cytoplasmic levels of TDP-43. In addition, the chronic intraperitoneal injection of LPS at a dose of 1mg/kg in TDP-43(A315T transgenic mice exacerbated the pathological TDP-43 accumulation in the cytoplasm of spinal motor neurons and it enhanced the levels of TDP-43 aggregation. These results suggest that inflammation may contribute to development or exacerbation of TDP-43 proteinopathies in neurodegenerative disorders.

  7. Synchronized Data Aggregation for Wireless Sensor Network

    DEFF Research Database (Denmark)

    Dnyaneshwar, Mantri; Prasad, Neeli R.; Prasad, Ramjee

    2014-01-01

    Wireless Sensor Networks (WSNs) are used for monitoring and data collection purposes. A key challenge in effective data collection is to schedule and synchronize the activities of the nodes with global clock. This paper proposes the Synchronized Data Aggregation Algorithm (SDA) using spanning tree...... mechanism. It provides network-wide time synchronization for sensor network. In the initial stage algorithm established the hierarchical structure in the network and then perform the pair - wise synchronization. SDA aggregate data with a global time scale throughout the network. The aggregated packets...... are scheduled using TDMA as the MAC layer protocol. Simulation results show that, SDA gives promising result of energy efficiency and delay as compared with state-of-the-art solutions....

  8. On Aggregating Human Capital Across Heterogeneous Cohorts

    DEFF Research Database (Denmark)

    Growiec, Jakub; Groth, Christian

    Based on a general framework for computing the aggregate human capital stock under heterogeneity across population cohorts, the paper derives aggregate human capital stocks in the whole population and in the labor force, and relates these variables to average years of schooling and average work...... experience. Under the scenarios considered here, the "macro-Mincer" (log-linear) relationship between aggregate human capital and average years of schooling is obtained only in cases which are inconsistent with heterogeneity in years of schooling and based on empirically implausible demographic survival laws....... Our numerical results indicate that the macro-Mincer equation can be a reasonable approximation of the true relationship only if returns to schooling and work experience are roughly constant across countries...

  9. SUMO modulation of protein aggregation and degradation

    Directory of Open Access Journals (Sweden)

    Marco Feligioni

    2015-09-01

    Full Text Available Small ubiquitin-like modifier (SUMO conjugation and binding to target proteins regulate a wide variety of cellular pathways. The functional aspects of SUMOylation include changes in protein-protein interactions, intracellular trafficking as well as protein aggregation and degradation. SUMO has also been linked to specialized cellular pathways such as neuronal development and synaptic transmission. In addition, SUMOylation is associated with neurological diseases associated with abnormal protein accumulations. SUMOylation of the amyloid and tau proteins involved in Alzheimer's disease and other tauopathies may contribute to changes in protein solubility and proteolytic processing. Similar events have been reported for α-synuclein aggregates found in Parkinson's disease, polyglutamine disorders such as Huntington's disease as well as protein aggregates found in amyotrophic lateral sclerosis (ALS. This review provides a detailed overview of the impact SUMOylation has on the etiology and pathology of these related neurological diseases.

  10. On Aggregating Human Capital Across Heterogeneous Cohorts

    DEFF Research Database (Denmark)

    Growiec, Jakub; Groth, Christian

    Based on a general framework for computing the aggregate human capital stock under heterogeneity across population cohorts, the paper derives aggregate human capital stocks in the whole population and in the labor force, and relates these variables to average years of schooling and average work...... experience. Under the scenarios considered here, the "macro-Mincer" (log-linear) relationship between aggregate human capital and average years of schooling is obtained only in cases which are inconsistent with heterogeneity in years of schooling and based on empirically implausible demographic survival laws....... Our numerical results indicate that the macro-Mincer equation can be a reasonable approximation of the true relationship only if returns to schooling and work experience are roughly constant across countries...

  11. Influence of polysaccharides on wine protein aggregation.

    Science.gov (United States)

    Jaeckels, Nadine; Meier, Miriam; Dietrich, Helmut; Will, Frank; Decker, Heinz; Fronk, Petra

    2016-06-01

    Polysaccharides are the major high-molecular weight components of wines. In contrast, proteins occur only in small amounts in wine, but contribute to haze formation. The detailed mechanism of aggregation of these proteins, especially in combination with other wine components, remains unclear. This study demonstrates the different aggregation behavior between a buffer and a model wine system by dynamic light scattering. Arabinogalactan-protein, for example, shows an increased aggregation in the model wine system, while in the buffer system a reducing effect is observed. Thus, we could show the importance to examine the behavior of wine additives under conditions close to reality, instead of simpler buffer systems. Additional experiments on melting points of wine proteins reveal that only some isoforms of thaumatin-like proteins and chitinases are involved in haze formation. We can confirm interactions between polysaccharides and proteins, but none of these polysaccharides is able to prevent haze in wine.

  12. Linguistic Weighted Aggregation under Confidence Levels

    Directory of Open Access Journals (Sweden)

    Chonghui Zhang

    2015-01-01

    Full Text Available We develop some new linguistic aggregation operators based on confidence levels. Firstly, we introduce the confidence linguistic weighted averaging (CLWA operator and the confidence linguistic ordered weighted averaging (CLOWA operator. These two new linguistic aggregation operators are able to consider the confidence level of the aggregated arguments provided by the information providers. We also study some of their properties. Then, based on the generalized means, we introduce the confidence generalized linguistic ordered weighted averaging (CGLOWA operator. The main advantage of the CGLOWA operator is that it includes a wide range of special cases such as the CLOWA operator, the confidence linguistic ordered weighted quadratic averaging (CLOWQA operator, and the confidence linguistic ordered weighted geometric (CLOWG operator. Finally, we develop an application of the new approach in a multicriteria decision-making under linguistic environment and illustrate it with a numerical example.

  13. Multi-Dimensional Aggregation for Temporal Data

    DEFF Research Database (Denmark)

    Böhlen, M. H.; Gamper, J.; Jensen, Christian Søndergaard

    2006-01-01

    when the data hold. In temporal databases, intervals typically capture the states of reality that the data apply to, or capture when the data are, or were, part of the current database state. This paper proposes a new aggregation operator that addresses several challenges posed by interval data. First......Business Intelligence solutions, encompassing technologies such as multi-dimensional data modeling and aggregate query processing, are being applied increasingly to non-traditional data. This paper extends multi-dimensional aggregation to apply to data with associated interval values that capture......, the intervals to be associated with the result tuples may not be known in advance, but depend on the actual data. Such unknown intervals are accommodated by allowing result groups that are specified only partially. Second, the operator contends with the case where an interval associated with data expresses...

  14. Principles of Need and the Aggregation Thesis.

    Science.gov (United States)

    Gustavsson, Erik; Juth, Niklas

    2017-09-02

    Principles of need are constantly referred to in health care priority setting. The common denominator for any principle of need is that it will ascribe some kind of special normative weight to people being worse off. However, this common ground does not answer the question how a plausible principle of need should relate to the aggregation of benefits across individuals. Principles of need are sometimes stated as being incompatible with aggregation and sometimes characterized as accepting aggregation in much the same way as utilitarians do. In this paper we argue that if one wants to take principles of need seriously both of these positions have unreasonable implications. We then characterize and defend a principle of need consisting of sufficientarian elements as well as prioritarian which avoids these unreasonable implications.

  15. Relationship between macroeconomic aggregates and bank performance

    Directory of Open Access Journals (Sweden)

    Mitrović Ranka

    2016-01-01

    Full Text Available The aim of the paper is relations between some macroeconomic aggregates and performance of banks. This paper show analysis of trends in gross domestic product, exchange rates, interest rates, inflation load, developments in the balance of payments. On the business side, performance is achieved insight into the liquidity, capital adequacy, and the amount of non-performable loans. The aim of the research is to refute or confirm the interconnectedness of movement values of macroeconomic aggregates and bank performance. The analysis confirmed the association of two set variables. The negative value movements of macroeconomic aggregates directly or indirectly have an impact on the quality of performance of the banking sector. Therefore, it is necessary to define an adequate strategy of the economy, would not it safer to carry out the process of adapting to new developments in the market, such as the global financial crisis, the rise in unproductive enterprises, distrust customers etc.

  16. The Nation's top 25 construction aggregates producers

    Science.gov (United States)

    Willett, Jason Christopher

    2013-01-01

    U.S. production of construction aggregates in 2011 was 2.17 billion short tons, valued at $17.2 billion, free on board (f.o.b.) at plant. Construction aggregates production decreased by 37 percent, and the associated value decreased by 25 percent, compared with the record highs reported in 2006. In 2011, construction aggregates production increased for the first time since 2006, owing to a very slight increase in the production of both construction sand and gravel and crushed stone. The average unit value, which is the f.o.b. at plant price of a ton of material, increased slightly, but is still less than the average unit value of two years prior.

  17. Mechanical Properties of Autoclaved Shell-aggregate

    Institute of Scientific and Technical Information of China (English)

    MA Hailong; CUI Chong; LI Xing; Pierre Chevrier; Vanessa Bouchart; TANG Feng

    2011-01-01

    Waste solid propylene oxide sludge(POS)and fly ash were used as main raw material to prepare propylene oxide sludge aggregate(POSA)under the condition of autoclaved(180 ℃,1.0 MPa)curing.Three different test methods namely cylinder compressive strength(CCS),individual aggregate compressive strength(IACS)and strength contribution rate(SCR)proposed were used to characterize the mechanical properties of the autoclaved POSA.POS shell-aggregate with SCR of 94% were prepared under the hydrothermal synthesis and autoclaved curing.The experimental results indicate that CCS and IACS have good consistency in characterizing mechanical properties of POSA.It is suggested that SCR not only can characterize the strength of POSA core,but also can reflect the effect of shell on the performance of POSA.By means of least square method,relationships between CCS and IACS,CCS and SCR,IACS and SCR were deduced.

  18. Wind energy aggregation: A coalitional game approach

    KAUST Repository

    Baeyens, E.

    2011-12-01

    In this paper we explore the extent to which a group of N wind power producers can exploit the statistical benefits of aggregation and quantity risk sharing by forming a willing coalition to pool their variable power to jointly offer their aggregate power output as single entity into a forward energy market. We prove that wind power generators will always improve their expected profit when they aggregate their generated power and use tools from coalitional game theory to design fair sharing mechanisms to allocate the payoff among the coalition participants. We show that the corresponding coalitional game is super-additive and has a nonempty core. Hence, there always exists a mechanism for profit-sharing that makes the coalition stable. However, the game is not convex and the celebrated Shapley value may not belong to the core of the game. An allocation mechanism that minimizes the worst-case dissatisfaction is proposed. © 2011 IEEE.

  19. Aggregation of organic matter by pelagic tunicates

    Energy Technology Data Exchange (ETDEWEB)

    Pomeroy, L.R. (Univ. of Georgia, Athens); Deibel, D.

    1980-07-01

    Three genera of pelagic tunicates were fed concentrates of natural seston and an axenic diatom culture. Fresh and up to 4-day-old feces resemble flocculent organic aggregates containing populations of microorganisms, as described from highly productive parts of the ocean, and older feces resemble the nearly sterile flocculent aggregates which are ubiquitous in surface waters. Fresh feces consist of partially digested phytoplankton and other inclusions in an amorphous gelatinous matrix. After 18 to 36 h, a population of large bacteria develops in the matrix and in some of the remains of phytoplankton contained in the feces. From 48 to 96 h, protozoan populations arise which consume the bacteria and sometimes the remains of the phytoplankton in the feces. Thereafter only a sparse population of microorganisms remains, and the particles begin to fragment. Water samples taken in or below dense populations of salps and doliolids contained greater numbers of flocculent aggregates than did samples from adjacent stations.

  20. Aggregation kinetics and structure of cryoimmunoglobulins clusters

    CERN Document Server

    De Spirito, M; Bassi, F A; Di Stasio, E; Giardina, B; Arcovito, G

    2002-01-01

    Cryoimmunoglobulins are pathological antibodies characterized by a temperature-dependent reversible insolubility. Rheumatoid factors (RF) are immunoglobulins possessing anti-immunoglobulin activity and usually consist of an IgM antibody that recognizes IgG as antigen. These proteins are present in sera of patients affected by a large variety of different pathologies, such as HCV infection, neoplastic and autoimmune diseases. Aggregation and precipitation of cryoimmunoglobulins, leading to vasculiti, are physical phenomena behind such pathologies. A deep knowledge of the physico-chemical mechanisms regulating such phenomena plays a fundamental role in biological and clinical applications. In this work, a preliminary investigation of the aggregation kinetics and of the final macro- molecular structure of the aggregates is presented. Through static light scattering techniques, the gyration radius R/sub g/ and the fractal dimension D/sub m/ of the growing clusters have been determined. However, while the initial ...

  1. Chaperone effects on prion and nonprion aggregates.

    Science.gov (United States)

    Rikhvanov, Eugene G; Romanova, Nina V; Chernoff, Yury O

    2007-01-01

    Exposure to high temperature or other stresses induces a synthesis of heat shock proteins. Many of these proteins are molecular chaperones, and some of them help cells to cope with heat-induced denaturation and aggregation of other proteins. In the last decade, chaperones have received increased attention in connection with their role in maintenance and propagation of the Saccharomyces cerevisiae prions, infectious or heritable agents transmitted at the protein level. Recent data suggest that functioning of the chaperones in reactivation of heat-damaged proteins and in propagation of prions is based on the same molecular mechanisms but may lead to different consequences depending on the type of aggregate. In both cases the concerted and balanced action of "chaperones' team," including Hsp104, Hsp70, Hsp40 and possibly other proteins, determines whether a misfolded protein is to be incorporated into an aggregate, rescued to the native state or targeted for degradation.

  2. Mechanics of Graded Wrinkles

    Science.gov (United States)

    Raayai-Ardakani, Shabnam; Boyce, Mary

    2013-03-01

    Shark skin is known for its anti-fouling and self-cleaning properties. In attempts to mimic this pattern for getting similar properties, different surface patterns such as Sharklet and wrinkles have been previously introduced. Wrinkled patterns have gained importance in applications such as microfluidics, wetting and adhesion. Through buckling of a thin film of stiff material on a substrate of softer material, and maintaining symmetric geometries, ordered wrinkled patterns can be created. However, it can be shown that using the same principle, by changing the geometry of the surface, the dimensions of the wrinkles can be altered. This alteration turns ordered wrinkles into graded wrinkles which have more resemblance to shark skin than the ordered wrinkles, maintaining the same wave length while each wave having different amplitude. Here using finite element models, experiments and analytical solutions, the relations between different geometries and the resulting patterns were investigated.

  3. Koszul differential graded modules

    Institute of Scientific and Technical Information of China (English)

    HE JiWei; WU QuanShui

    2009-01-01

    The concept of Koszulity for differential graded (DG, for short) modules is introduced. It is shown that any bounded below DG module with bounded Ext-group to the trivial module over a Koszul DG algebra has a Koszul DG submodule (up to a shift and truncation), moreover such a DG module can be approximated by Koszul DG modules (Theorem 3.6). Let A be a Koszul DG algebra, and Dc (A) be the full triangulated subcategory of the derived category of DG A-modules generated by the object AA. If the trivial DG module kA lies in Dc(A), then the heart of the standard t-structure on Dc(A) is anti-equivalent to the category of finitely generated modules over some finite dimensional algebra. As a corollary, Dc(A) is equivalent to the bounded derived category of its heart as triangulated categories.

  4. Koszul differential graded modules

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    The concept of Koszulity for differential graded (DG, for short) modules is introduced. It is shown that any bounded below DG module with bounded Ext-group to the trivial module over a Koszul DG algebra has a Koszul DG submodule (up to a shift and truncation), moreover such a DG module can be approximated by Koszul DG modules (Theorem 3.6). Let A be a Koszul DG algebra, and Dc(A) be the full triangulated subcategory of the derived category of DG A-modules generated by the object AA. If the trivial DG module kA lies in Dc(A), then the heart of the standard t-structure on Dc(A) is anti-equivalent to the category of finitely generated modules over some finite dimensional algebra. As a corollary, Dc(A) is equivalent to the bounded derived category of its heart as triangulated categories.

  5. Open access and open source in chemistry

    Directory of Open Access Journals (Sweden)

    Todd Matthew H

    2007-02-01

    Full Text Available Abstract Scientific data are being generated and shared at ever-increasing rates. Two new mechanisms for doing this have developed: open access publishing and open source research. We discuss both, with recent examples, highlighting the differences between the two, and the strengths of both.

  6. Een boekje open over Open Source ERP

    NARCIS (Netherlands)

    Sneller, A.C.W.(L.)

    2009-01-01

    Er zijn vele ERP-systemen die met behulp van open source worden ontwikkeld. Organisaties die open source ERP willen implementeren staan voor twee strategische keuzes: hoe zit het met de continuïteit en wie gaat het systeem onderhouden?

  7. Open Government and (Linked (Open (Government (Data

    Directory of Open Access Journals (Sweden)

    Christian Philipp Geiger

    2012-12-01

    Full Text Available This article explores the opening and the free usage of stored public sector data, supplied by state. In the age of Open Government and Open Data it’s not enough just to put data online. It should be rather weighed out whether, how and which supplied public sector data can be published. Open Data are defined as stored data which could be made accessible in a public interest without any restrictions for usage and distribution. These Open Data can possibly be statistics, geo data, maps, plans, environmental data and weather data in addition to materials of the parliaments, ministries and authorities. The preparation and the free access to existing data permit varied approaches to the reuse of data, discussed in the article. In addition, impulses can be given for Open Government – the opening of state and administration, to more transparency, participation and collaboration as well as to innovation and business development. The Open Data movement tries to get to the bottom of current publication processes in the public sector which could be formed even more friendly to citizens and enterprises.

  8. APPLICATION OF PACKING THEORY ON GRADING DESIGN FOR POROUS ASPHALT MIXTURES

    Directory of Open Access Journals (Sweden)

    Hardiman Hardiman

    2004-01-01

    Full Text Available The design life of porous asphalt is shorter than dense mix as a consequence of permeability loss due to clogging and poor resistance to disintegration. To mitigate problems associated with clogging, double layer porous asphalt has been constructed in the Netherlands. This paper investigated a development of a new grading design for porous asphalt by varying percentage of aggregate with maximum sizes of 20, 14 and 10mm; a theory of packing was used. The most common method used for grading design is based on empirical, which does not relate the packing behaviour of the aggregate mass. The packing theory used in this study was facilitated by a vibratory compactor. It was found that mixtures containing aggregate sizes 14 and 10mm have a good permeability and stability, when vibrated for 65 second with a frequency of 40Hz, while for aggregates containing 20mm, to achieve the requirement for Marshall stability, the gradation needs to be modified. Properties of porous asphalt based on packing theory are better from the empirical grading from Spain (P-12.

  9. Effect of humic substances aggregation on the determination of fluoride in water using an ion selective electrode.

    Science.gov (United States)

    Shen, Junjie; Gagliardi, Simona; McCoustra, Martin R S; Arrighi, Valeria

    2016-09-01

    The control of drinking water quality is critical in preventing fluorosis. In this study humic substances (HS) are considered as representative of natural organic matter (NOM) in water. We show that when HS aggregate the response of fluoride ion selective electrodes (ISE) may be perturbed. Dynamic light scattering (DLS) results of both synthetic solutions and natural water sample suggest that low pH and high ionic strength induce HS aggregation. In the presence of HS aggregates, fluoride concentration measured by ISE has a reduction up to 19%. A new "open cage" concept has been developed to explain this reversible phenomenon. The interference of HS aggregation on fluoride measurement can be effectively removed by centrifugation pretreatment.

  10. Single soil particle or an aggregate?

    Science.gov (United States)

    Szabó, Judit Alexandra; Kovács, József; Szabó, Boglárka; Szalai, Zoltán; Jakab, Gergely

    2017-04-01

    The knowledge of particle size distribution (PSD) of the soil is essential in many soil-related studies, as well as in erosional studies. Not only single particles are translocated during erosion process, but also aggregates of various size. Both of these types are responsible for either the redistribution of the nutrients and organic matter or for their in situ accumulation. The mentioned selectivity, the detachment and the early stage of the transport phase of the erosion were studied. Are the factors as slope or moisture content have an effect on the aggregate/particle size distribution of the runoff in case of the same soil sample? Which fraction dominates in the soil and the runoff? Laboratory rainfall simulation experiments were applied for six different treatments: detailed studies were made on the aggregate size distribution of the runoff and the particle size distribution of the aggregate size classes. The results showed the followings: 1) the >1mm macroaggregate fraction, which dominated the control sample (40%) was missing in the soil loss; 2) the ratio of microaggregates was increased (from 30% to 70%). The ratio of >50µm fraction was smaller in steeper slope and the fraction of 50-250µm decreased to its half under extremely dry or saturated condition. The PSD histograms were similar per fraction in each treatment, but the shape of the PSD histograms suggested that there were unbroken aggregates in the sample. As we concluded, the real question could be, if it is really needed to measure particles. It could it also be possible that if a small (60-110 µm) aggregate (which is still stable after drop erosion and transportation) could be chemically broken down or it has to be counted with as a particle during modelling? The used particle size analyser was purchased with the support of KMOP project no. 4.2.1/ B-10-2011-0002. The authors gratefully acknowledge this support.

  11. Two compounds in bed bug feces are sufficient to elicit off-host aggregation by bed bugs, Cimex lectularius.

    Science.gov (United States)

    Olson, Joelle F; Vers, Leonard M Ver; Moon, Roger D; Kells, Stephen A

    2017-01-01

    After feeding, bed bugs aggregate in cracks and crevices near a host. Aggregation and arrestment are mediated by tactile and chemical stimuli associated with the bugs' feces and exuviae. Volatiles derived from fecally stained filter papers were analyzed by solid-phase microextraction (SPME) and evaluated using a multichoice behavioral assay to determine their impact on bed bug aggregation. In addition, crude fecal extracts were collected in methanol, analyzed by gas chromatography coupled with electroantennogram detection (GC-EAD) and mass spectrometry (GC-MS) and evaluated in open-air multichoice behavioral assays. The SPME method was used to detect (E)-2-hexenal and (E)-2-octenal in heated bed bug feces. The presence of these two volatile components did not affect aggregation. Analysis of the crude fecal extracts revealed several semi-volatile nitrogenous compounds, a carboxylic acid and a sulfur-based compound. Adult antennae responded to compounds eluted from three regions of the crude extract using GC-EAD. A combination of two compounds, dimethyl trisulfide and methyldiethanolamine, resulted in aggregation responses equivalent to the original crude extract. Bed bug aggregation is mediated by semi-volatile compounds derived from fecal extracts, and two compounds are sufficient to elicit aggregation. The two compounds identified here could be used to enhance the effectiveness of insecticidal applications or improve monitoring techniques. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

  12. Aggregate Malanobis Distance Function Approach to Evolve a HYBRID AWALE Player

    Directory of Open Access Journals (Sweden)

    Keneilwe Zuva

    2012-08-01

    Full Text Available The game of Awale is a member of the Mancala family.The problem of developing a good agent for playing Mancala games by a computer agent is an open issue. This study presents an agent that is based on the combination of Minimax search and Aggregate Malanobis Distance Function (AMDF, to evolve an agent that can play Awale at a competitive level. The result of the combination is appealing.

  13. Interbank Market Structure and Accurate Estimation of an Aggregate Liquidity Shock

    OpenAIRE

    Isakov, A.

    2013-01-01

    It's customary among money market analysts to blame interest rate deviations from the Bank of Russia's target band on the market structure imperfections or segmentation. We isolate one form of such market imperfection and provide an illustration of its potential impact on central bank's open market operations efficiency in the current monetary policy framework. We then hypothesize that naive (market) structure-agnostic liquidity gap aggregation will lead to market demand underestimation in so...

  14. Quasi-Species and Aggregate Dynamics

    DEFF Research Database (Denmark)

    Eriksson, Anders; Görnerup, Olof; Jacobi, Martin Nilsson

    2005-01-01

    a partial differential equation that describes the system. We find that the relative prevalence of fast and slow replicators is determined by the relative strength of selection at the aggregate level to the selection strength at the molecular level. The analysis is concluded by a preliminary treatment...... aggregates, proto-organisms, that host populations of replicating information carrying molecules. Some of the molecules promote the reproduction of the proto-organism at the cost of their individual replication rate. A situation resembling that of group selection arises. We derive and analytically solve...... of finite population size effects....

  15. 200 North Aggregate Area source AAMS report

    Energy Technology Data Exchange (ETDEWEB)

    1993-06-01

    This report presents the results of an aggregate area management study (AAMS) for the 200 North Aggregate Area in the 200 Areas of the US Department of Energy (DOE) Hanford Site in Washington State. This scoping level study provides the basis for initiating Remedial Investigation/Feasibility Study (RI/FS) activities under the Comprehensive Environmental Response, Compensation, and Liability Act of 1980 (CERCLA) or Resource Conservation and Recovery Act (RCRA) Facility Investigations (RFI) and Corrective Measures Studies (CMS) under RCRA. This report also integrates select RCRA treatment, storage, or disposal (TSD) closure activities with CERCLA and RCRA past practice investigations.

  16. An Aggregation Approach for Group Multicriteria Assignment

    Directory of Open Access Journals (Sweden)

    George Rigopoulos

    2008-01-01

    Full Text Available We presented an aggregation approach for group multicriteria assignment decisions, where group members express their preferences on problem parameters in numeric format. Individual preferences are aggregated by WOWA operator following the majority concept and a group parameter set is derived that is used as input for the classification algorithm. In addition, we present a numeric example of the approach, demonstrating its applicability. The methodology has been applied to classification problems in business environment, with sufficient results depicting its validity for such problems.

  17. Relative aggregation operator in database fuzzy querying

    Directory of Open Access Journals (Sweden)

    Luminita DUMITRIU

    2005-12-01

    Full Text Available Fuzzy selection criteria querying relational databases include vague terms; they usually refer linguistic values form the attribute linguistic domains, defined as fuzzy sets. Generally, when a vague query is processed, the definitions of vague terms must already exist in a knowledge base. But there are also cases when vague terms must be dynamically defined, when a particular operation is used to aggregate simple criteria in a complex selection. The paper presents a new aggregation operator and the corresponding algorithm to evaluate the fuzzy query.

  18. Rotor-Router Aggregation on the Comb

    OpenAIRE

    Huss, Wilfried; Sava, Ecaterina

    2011-01-01

    We prove a shape theorem for rotor-router aggregation on the comb, for a specific initial rotor configuration and clockwise rotor sequence for all vertices. Furthermore, as an application of rotor-router walks, we describe the harmonic measure of the rotor-router aggregate and related shapes, which is useful in the study of other growth models on the comb. We also identify the shape for which the harmonic measure is uniform. This gives the first known example where the rotor-router cluster ha...

  19. Interface-Based Service Composition with Aggregation

    DEFF Research Database (Denmark)

    Dalla Preda, Mila; Gabbrielli, Maurizio; Guidi, Claudio

    2012-01-01

    Service-oriented architectures (SOAs) usually comprehend in-the-middle entities such as proxies or service mediators that compose services abstracting from the order in which they exchange messages. Although widely used, these entities are usually implemented by means of ad-hoc solutions....... In this paper we generalise this composition mechanism by identifying the primitive notion of aggregation. We formally define the semantics of aggregation in terms of a process calculus. We also provide a reference implementation for this primitive by extending the Jolie language, thus allowing...

  20. Protein Aggregation Measurement through Electrical Impedance Spectroscopy

    Science.gov (United States)

    Affanni, A.; Corazza, A.; Esposito, G.; Fogolari, F.; Polano, M.

    2013-09-01

    The paper presents a novel methodology to measure the fibril formation in protein solutions. We designed a bench consisting of a sensor having interdigitated electrodes, a PDMS hermetic reservoir and an impedance meter automatically driven by calculator. The impedance data are interpolated with a lumped elements model and their change over time can provide information on the aggregation process. Encouraging results have been obtained by testing the methodology on K-casein, a protein of milk, with and without the addition of a drug inhibiting the aggregation. The amount of sample needed to perform this measurement is by far lower than the amount needed by fluorescence analysis.

  1. A comparison of thermal zone aggregation methods

    Energy Technology Data Exchange (ETDEWEB)

    Dobbs, Justin R. [Cornell University; Hencey, Brandon M. [Cornell University

    2012-12-10

    The impact of increasing energy prices on building operation budgets has fueled demand for more energy-efficient structures. Existing building energy simulation tools generate an immense amount of data yet comparatively little knowledge. This paper introduces a framework that allows aggregation-based model reduction to operate on geometric building information models. The resulting aggregation sequence provides designers with faster simulations and affords insight into complex multi-scale thermal interactions. A comparison of the trade-off between simulation speed and accuracy for three hierarchical cluster partitioning methods concludes the discussion.

  2. Does it Matter How to Measure Aggregates?

    DEFF Research Database (Denmark)

    Beyer, Andreas; Juselius, Katarina

    . This papers shows, however, that the latter is sensitive to the choice of base year when based on real GDP weights whereas not on nominal GDP weights. A comparison of aggregates calculated with different methods shows that the differences are tiny in absolute value but highly persistent. To investigate...... the impact on the cointegration properties in empirical modelling, the monetary model in Coenen & Vega (2001) based on fixed weights was re-estimated using flexible real and nominal GDP weights. In general, the results remained reasonably robust to the choice of aggregation method...

  3. Fault tolerant aggregation for power system services

    DEFF Research Database (Denmark)

    Kosek, Anna Magdalena; Gehrke, Oliver; Kullmann, Daniel

    2013-01-01

    Exploiting the flexibility in distributed energy resources (DER) is seen as an important contribution to allow high penetrations of renewable generation in electrical power systems. However, the present control infrastructure in power systems is not well suited for the integration of a very large...... number of small units. A common approach is to aggregate a portfolio of such units together and expose them to the power system as a single large virtual unit. In order to realize the vision of a Smart Grid, concepts for flexible, resilient and reliable aggregation infrastructures are required...

  4. Does it Matter How to Measure Aggregates?

    DEFF Research Database (Denmark)

    Beyer, Andreas; Juselius, Katarina

    . This papers shows, however, that the latter is sensitive to the choice of base year when based on real GDP weights whereas not on nominal GDP weights. A comparison of aggregates calculated with different methods shows that the differences are tiny in absolute value but highly persistent. To investigate...... the impact on the cointegration properties in empirical modelling, the monetary model in Coenen & Vega (2001) based on fixed weights was re-estimated using flexible real and nominal GDP weights. In general, the results remained reasonably robust to the choice of aggregation method...

  5. Blood platelet-derived microparticles release and bubble formation after an open-sea air dive.

    Science.gov (United States)

    Pontier, Jean-Michel; Gempp, Emmanuel; Ignatescu, Mihaela

    2012-10-01

    Bubble-induced platelet aggregation offers an index for evaluating decompression severity in humans and in a rat model of decompression sickness. Endothelial cells, blood platelets, or leukocytes shed microparticles (MP) upon activation and during cell apoptosis. The aim was to study blood platelet MP (PMP) release and bubble formation after a scuba-air dive in field conditions. Healthy, experienced divers were assigned to 1 experimental group (n = 10) with an open-sea air dive to 30 msw for 30 min and 1 control group (n = 5) during head-out water immersion for the same period. Bubble grades were monitored with a pulsed doppler according to Kissman Integrated Severity Score (KISS). Blood samples for platelet count (PC) and PMP (annexin V and CD41) were taken 1 h before and after exposure in both groups. The result showed a decrease in post-dive PC compared with pre-dive values in experimental group with no significant change in the control group. We observed a significant increase in PMP values after the dive while no change was revealed in the control group. There was a significant positive correlation between the PMP values after the dive and the KISS bubble score. The present study highlighted a relationship between the post-dive decrease in PC, platelet MP release, and bubble formation. Release of platelet MPs could reflect bubble-induced platelet aggregation and could play a key role in alteration of the coagulation. Further studies must investigate endothelial and leukocyte MP release in the same field conditions.

  6. Simplification in Graded Readers: Measuring the Authenticity of Graded Texts

    Science.gov (United States)

    Claridge, Gillian

    2005-01-01

    This study examines the characteristics and quality of simplification in graded readers as compared to those of "normal" authentic English. Two passages from graded readers are compared with the original passages. The comparison uses a computer programme, RANGE (Nation and Heatley, 2003) to analyse the distribution of high and low frequency words…

  7. Grade Point Average and Changes in (Great) Grade Expectations.

    Science.gov (United States)

    Wendorf, Craig A.

    2002-01-01

    Examines student grade expectations throughout a semester in which students offered their expectations three times during the course: (1) within the first week; (2) midway through the semester; and (3) the week before the final examination. Finds that their expectations decreased stating that their cumulative grade point average was related to the…

  8. Open Source Software Development and Lotka's Law: Bibliometric Patterns in Programming.

    Science.gov (United States)

    Newby, Gregory B.; Greenberg, Jane; Jones, Paul

    2003-01-01

    Applies Lotka's Law to metadata on open source software development. Authoring patterns found in software development productivity are found to be comparable to prior studies of Lotka's Law for scientific and scholarly publishing, and offer promise in predicting aggregate behavior of open source developers. (Author/LRW)

  9. Semi-automatic grading system in histologic and immunohistochemistry analysis to evaluate in vitro chondrogenesis

    Directory of Open Access Journals (Sweden)

    Johana Guevara Morales

    2012-08-01

    Full Text Available During embryological limb formation mesenchymal cells condense and differentiate into chondrocytes, in a process known aschondrogenesis. These chondrocytes synthesize glycosaminoglycans (GAGs, thus playing an important role in this process.A simplified system in vitro chondrogenesis, using adult mesenchymal stromal cells (MSCs has been demonstrated. Thisdifferentiation potential is usually assessed by histological staining. Objective. Establishment of a semi-automatic grading systemfor histochemistry stains and immunohistochemistry assays. Materials and methods. For chondrogenesis cells were culturedfor three weeks in aggregates with inducing media. Total GAGs were measured using dimethylmethylene blue (DMB method.For histological analyses aggregates were stained with Alcian blue for total GAGs detection and immunohistochemistry (IHCfor aggrecan was performed. Semi-automatic grading for all slides was obtained after ImageJ analysis. Results. MSCs culturedas aggregates in chondrogenic differentiation media had similar protein concentrations for all time points, suggesting cellularityremained homogenous during culture. Total GAGs was higher for aggregates cultured in chondrogenic compared to complete media.The same trend was observed for Alcian blue stain grades by blinded observer and analysis using ImageJ software. Aggrecan’s IHCanalysis had a decreasing tendency with time for aggregates in chondrogenic media for blinded observer and ImageJ evaluation.Conclusion. We developed a functional system for semi-automatic slide grading. We corroborated these results by biochemicalanalysis with comparable results. To our knowledge, for in vitro chondrogenesis, this is the first report to evaluate stains usingthis methodology. This procedure might be useful for other applications in the field of Biology and Medical Sciences.

  10. To Aggregate or Not and Potentially Better Questions for Clustered Data: The Need for Hierarchical Linear Modeling in CTE Research

    Science.gov (United States)

    Nimon, Kim

    2012-01-01

    Using state achievement data that are openly accessible, this paper demonstrates the application of hierarchical linear modeling within the context of career technical education research. Three prominent approaches to analyzing clustered data (i.e., modeling aggregated data, modeling disaggregated data, modeling hierarchical data) are discussed…

  11. Direct-write graded index materials realized in protein hydrogels

    Science.gov (United States)

    Kaehr, Bryan; Scrymgeour, David A.

    2016-09-01

    The ability to create optical materials with arbitrary index distributions would prove transformative for optics design and applications. However, current fabrication techniques for graded index (GRIN) materials rely on diffusion profiles and therefore are unable to realize arbitrary distribution GRIN design. Here, we demonstrate the laser direct writing of graded index structures in protein-based hydrogels using multiphoton lithography. We show index changes spanning a range of 10-2, which is comparable with laser densified glass and polymer systems. Further, we demonstrate the conversion of these written density variation structures into SiO2, opening up the possibility of transforming GRIN hydrogels to a wide range of material systems.

  12. Gleason Grade Progression Is Uncommon

    Science.gov (United States)

    Penney, Kathryn L.; Stampfer, Meir J.; Jahn, Jaquelyn L; Sinnott, Jennifer A.; Flavin, Richard; Rider, Jennifer R.; Finn, Stephen; Giovannucci, Edward; Sesso, Howard D.; Loda, Massimo; Mucci, Lorelei A.; Fiorentino, Michelangelo

    2013-01-01

    Gleason grade is universally used for pathologic scoring the differentiation of prostate cancer. However, it is unknown whether prostate tumors arise well-differentiated and then progress to less differentiated forms or if Gleason grade is an early and largely unchanging feature. Prostate Specific Antigen (PSA) screening has reduced the proportion of tumors diagnosed at advanced stage, which allows assessment of this question on a population level. If Gleason grade progresses as stage does, one would expect a similar reduction in high grade tumors. We studied 1,207 Physicians’ Health Study and Health Professionals Follow-up Study participants diagnosed with prostate cancer 1982–2004 and treated with prostatectomy. We compared the distribution of grade and clinical stage across the pre-PSA and PSA screening eras. We re-reviewed grade using the ISUP 2005 revised criteria. The proportion of advanced stage tumors dropped more than six-fold, from the earliest period (12/1982–1/1993), 19.9% stage ≥T3, to the latest (5/2000–12/2004), 3% stage T3, none T4. The proportion of Gleason score ≥8 decreased substantially less, from 25.3% to 17.6%. A significant interaction between stage and diagnosis date predicting grade (p=0.04) suggests the relationship between grade and stage varies by time period. As the dramatic shift in stage since the introduction of PSA screening was accompanied by a more modest shift in Gleason grade, these findings suggest grade may be established early in tumor pathogenesis. This has implications for the understanding of tumor progression and prognosis, and may help patients diagnosed with lower grade disease feel more comfortable choosing active surveillance. PMID:23946472

  13. Transportation and utilization of aggregates for road construction

    Science.gov (United States)

    Fladvad, Marit; Wigum, Børge Johannes; Aurstad, Joralf

    2017-04-01

    Road construction relies on non-renewable aggregate resources as the main construction material. Sources for high-quality aggregate resources are scattered, and requirements for aggregate quality can cause long transport distances between quarry and road construction site. In European countries, the average aggregate consumption per capita is 5 tonnes per year (European Aggregates Association, 2016), while the corresponding figure for Norway is 11 tonnes (Neeb, 2015). Half the Norwegian aggregate production (sand, gravel and crushed rock) is used for road construction. In Norway, aggregate resources have been considered abundant. However, stricter requirement for aggregate quality, and increased concern for sustainability and environmental issues have spurred focus on reduction of transport lengths through better utilization of local aggregate materials. In this research project, information about pavement design and aggregate quality requirements were gathered from a questionnaire sent to selected experts from the World Road Organization (PIARC), European Committee for Standardization (CEN), and Nordic Road Association (NVF). The gathered data was compared to identify differences and similarities for aggregate use in the participating countries. Further, the data was compared to known data from Norway regarding: - amount of aggregates required for a road structure - aggregate transport lengths and related costs A total of 18 countries participated in the survey, represented by either road authorities, research institutions, or contractors. There are large variations in practice for aggregate use among the represented countries, and the selection of countries is sufficient to illustrate a variety in pavement designs, aggregate sizes, and quality requirements for road construction. There are considerable differences in both pavement thickness and aggregate sizes used in the studied countries. Total thicknesses for pavement structures varies from 220 mm to 2400 mm

  14. Quality guaranteed aggregation based model predictive control and stability analysis

    Institute of Scientific and Technical Information of China (English)

    LI DeWei; XI YuGeng

    2009-01-01

    The input aggregation strategy can reduce the online computational burden of the model predictive controller. But generally aggregation based MPC controller may lead to poor control quality. Therefore, a new concept, equivalent aggregation, is proposed to guarantee the control quality of aggregation based MPC. From the general framework of input linear aggregation, the design methods of equivalent aggregation are developed for unconstrained and terminal zero constrained MPC, which guarantee the actual control inputs exactly to be equal to that of the original MPC. For constrained MPC, quasi-equivalent aggregation strategies are also discussed, aiming to make the difference between the control inputs of aggregation based MPC and original MPC as small as possible. The stability conditions are given for the quasi-equivalent aggregation based MPC as well.

  15. Carrier Aggregation for LTE-Advanced

    DEFF Research Database (Denmark)

    Pedersen, Klaus Ingemann; Frederiksen, Frank; Rosa, Claudio

    2011-01-01

    Carrier aggregation (CA) is one of the key features for LTE-Advanced. By means of CA, users gain access to a total bandwidth of up to 100 MHz in order to meet the IMT-Advanced requirements. The system bandwidth may be contiguous, or composed of several non-contiguous bandwidth chunks, which are a...

  16. Utilitarian Aggregation of Beliefs and Tastes.

    Science.gov (United States)

    Gilboa, Itzhak; Samet, Dov; Schmeidler, David

    2004-01-01

    Harsanyi's utilitarianism is extended here to Savage's framework. We formulate a Pareto condition that implies that both society's utility function and its probability measure are linear combinations of those of the individuals. An indiscriminate Pareto condition has been shown to contradict linear aggregation of beliefs and tastes. We argue that…

  17. Individual expectations and aggregate macro behavior

    NARCIS (Netherlands)

    Assenza, T.; Heemeijer, P.; Hommes, C.; Massaro, D.

    2013-01-01

    The way in which individual expectations shape aggregate macroeconomic variables is crucial for the transmission and effectiveness of monetary policy. We study the individual expectations formation process and the interaction with monetary policy, within a standard New Keynesian model, by means of l

  18. Individual expectations and aggregate macro behavior

    NARCIS (Netherlands)

    Assenza, T.; Heemeijer, P.; Hommes, C.; Massaro, D.

    2011-01-01

    The way in which individual expectations shape aggregate macroeconomic variables is crucial for the transmission and effectiveness of monetary policy. We study the individual expectations formation process and the interaction with monetary policy, within a standard New Keynesian model, by means of l

  19. Aggregation of log-linear risks

    DEFF Research Database (Denmark)

    Embrechts, Paul; Hashorva, Enkeleijd; Mikosch, Thomas Valentin

    2014-01-01

    In this paper we work in the framework of a k-dimensional vector of log-linear risks. Under weak conditions on the marginal tails and the dependence structure of a vector of positive risks, we derive the asymptotic tail behaviour of the aggregated risk {and present} an application concerning log...

  20. Nonlinear Evolution of Aggregates with Inextensible Constraints

    Institute of Scientific and Technical Information of China (English)

    Ming-XiangCHEN; WeiYANG; 等

    1996-01-01

    Crystalline and semicrystalline polymers are formed as aggregates of grains with evolving inextensible axes.This inextensible constratint leads to texture evolution under large plastic deformation.This paper reveals the nonlinear texture evolution of crystalline polymers under axi-symmetric straining.

  1. Face detection by aggregated Bayesian network classifiers

    NARCIS (Netherlands)

    Pham, T.V.; Worring, M.; Smeulders, A.W.M.

    2002-01-01

    A face detection system is presented. A new classification method using forest-structured Bayesian networks is used. The method is used in an aggregated classifier to discriminate face from non-face patterns. The process of generating non-face patterns is integrated with the construction of the aggr

  2. Utilitarian Aggregation of Beliefs and Tastes.

    Science.gov (United States)

    Gilboa, Itzhak; Samet, Dov; Schmeidler, David

    2004-01-01

    Harsanyi's utilitarianism is extended here to Savage's framework. We formulate a Pareto condition that implies that both society's utility function and its probability measure are linear combinations of those of the individuals. An indiscriminate Pareto condition has been shown to contradict linear aggregation of beliefs and tastes. We argue that…

  3. DENDRIMER CONJUGATES FOR SELECTIVE OF PROTEIN AGGREGATES

    DEFF Research Database (Denmark)

    2004-01-01

    Dendrimer conjugates are presented, which are formed between a dendrimer and a protein solubilising substance. Such dendrimer conjugates are effective in the treatment of protein aggregate-related diseases (e.g. prion-related diseases). The protein solubilising substance and the dendrimer together...

  4. Aggregated Control of Domestic Heat Pumps

    DEFF Research Database (Denmark)

    Nielsen, Kirsten M.; Andersen, Palle; Pedersen, Tom S.

    2013-01-01

    A challenge in Denmark in the near future is to balance the electrical grid due to a large increase in the renewable energy production mainly from wind turbines. In this work an aggregated control system using heat pumps in single family houses to help balancing the grid is investigated. The cont...

  5. Kinetics of fibrilar aggregation of food proteins

    NARCIS (Netherlands)

    Arnaudov, L.N.

    2005-01-01

    In this thesis we study the kinetics of fibrilar aggregation of two model proteins widely used in the food industry -b-lactoglobulin (b-lg) and hen eg

  6. Ring aggregation pattern of Human Travel Trips

    CERN Document Server

    Wang, Zi-Yang; Zhu, Peng; Qin, Yong; Jia, Li-Min

    2015-01-01

    Although a lot of attentions have been paid to human mobility, the relationship between travel pattern with city structure is still unclear. Here we probe into this relationship by analyzing the metro passenger trip data.There are two unprecedented findings. One, from the average view a linear law exists between the individual's travel distance with his original distance to city center. The mechanism underlying is a travel pattern we called "ring aggregation", i.e., the daily movement of city passengers is just aggregating to a ring with roughly equal distance to city center.Interestingly, for the round trips the daily travel pattern can be regarded as a switching between the home ring at outer area with the office ring at the inner area. Second, this linear law and ring aggregation pattern seems to be an exclusive characteristic of the metro system. It can not be found in short distance transportation modes, such as bicycle and taxi, neither as multiple transportation modes. This means the ring aggregation p...

  7. Thermal unfolding and aggregation of actin.

    Science.gov (United States)

    Levitsky, Dmitrii I; Pivovarova, Anastasiya V; Mikhailova, Valeria V; Nikolaeva, Olga P

    2008-09-01

    Actin is one of the most abundant proteins in nature. It is found in all eukaryotes and plays a fundamental role in many diverse and dynamic cellular processes. Also, actin is one of the most ubiquitous proteins because actin-like proteins have recently been identified in bacteria. Actin filament (F-actin) is a highly dynamic structure that can exist in different conformational states, and transitions between these states may be important in cytoskeletal dynamics and cell motility. These transitions can be modulated by various factors causing the stabilization or destabilization of actin filaments. In this review, we look at actin stabilization and destabilization as expressed by changes in the thermal stability of actin; specifically, we summarize and analyze the existing data on the thermal unfolding of actin as measured by differential scanning calorimetry. We also analyze in vitro data on the heat-induced aggregation of actin, the process that normally accompanies actin thermal denaturation. In this respect, we focus on the effects of small heat shock proteins, which can prevent the aggregation of thermally denatured actin with no effect on actin thermal unfolding. As a result, we have proposed a mechanism describing the thermal denaturation and aggregation of F-actin. This mechanism explains some of the special features of the thermal unfolding of actin filaments, including the effects of their stabilization and destabilization; it can also explain how small heat shock proteins protect the actin cytoskeleton from damage caused by the accumulation of large insoluble aggregates under heat shock conditions.

  8. Surfactant effects on soil aggregate tensile strength

    Science.gov (United States)

    Little is known regarding a soil aggregate's tensile strength response to surfactants that may be applied to alleviate soil water repellency. Two laboratory investigations were performed to determine surfactant effects on the tensile strength of 1) Ap horizons of nine wettable, agricultural soils co...

  9. EFFECT OF AGGREGATION ON VIBRIO CHOLERAE INACTIVATION

    Science.gov (United States)

    Extensive research has shown that microorganisms exhibit increased resistance due to clumping, aggregation, particle association, or modification of antecedent growth conditions. During the course of investigating a major water-borne Vibrio cholerae outbreak in Peru, U.S. EPA inv...

  10. PALM KERNEL SHELL AS AGGREGATE FOR LIGHT

    African Journals Online (AJOL)

    of cement, sand, gravel andpalm kernel shells respectively gave the highest compressive strength of ... Keywords: Aggregate, Cement, Concrete, Sand, Palm Kernel Shell. ... delivered to the jOb Slte in a plastic ... structures, breakwaters, piers and docks .... related to cement content at a .... sheet and the summary is shown.

  11. CONSISTENT AGGREGATION IN FOOD DEMAND SYSTEMS

    OpenAIRE

    Levedahl, J. William; Reed, Albert J.; Clark, J. Stephen

    2002-01-01

    Two aggregation schemes for food demand systems are tested for consistency with the Generalized Composite Commodity Theorem (GCCT). One scheme is based on the standard CES classification of food expenditures. The second scheme is based on the Food Guide Pyramid. Evidence is found that both schemes are consistent with the GCCT.

  12. Metaconcrete: designed aggregates to enhance dynamic performance

    Science.gov (United States)

    Mitchell, Stephanie J.; Pandolfi, Anna; Ortiz, Michael

    2014-04-01

    We propose a new type of concrete for the attenuation of elastic waves induced by dynamic excitation. In this metamaterial, which we call metaconcrete, the stone, sand, and gravel aggregates of standard concrete are replaced with spherical inclusions consisting of a heavy metal core coated with a soft outer layer. These engineered aggregates can be tuned so that particular frequencies of a propagating blast wave will activate resonant oscillations of the heavy mass within the inclusions. The resonant behavior causes the system to exhibit negative effective mass, and this interaction between the wave motion and the resonant aggregates results in the attenuation of the applied dynamic loading. We introduce the concept of negative mass by deriving the effective momentum mass for the system and we define the geometrical and material parameters for the design of resonant aggregates. We develop finite element models for the analysis of metaconcrete behavior, defining a section of slab containing a periodic arrangement of inclusions. By computing the energy histories for the system when subject to a blast load, we show that there is a transfer of energy between the inclusions and the surrounding mortar. The inclusions are able to absorb a significant portion of the applied energy, resulting in a reduction in the amount of stress carried by the mortar phase and greatly improving the ability of the material to resist damage under explosive dynamic loading.

  13. Familial aggregation of hypospadias: a cohort study

    DEFF Research Database (Denmark)

    Schnack, Tine H; Zdravkovic, Slobodan; Myrup, Charlotte

    2008-01-01

    Hypospadias is one of the most common birth defects. However, its etiology remains largely unknown. The authors investigated the contribution of genetic and environmental factors to familial aggregation of hypospadias. Using Danish health registers, they identified 5,380 boys diagnosed...

  14. Propagation of Tau Aggregates and Neurodegeneration.

    Science.gov (United States)

    Goedert, Michel; Eisenberg, David S; Crowther, R Anthony

    2017-07-25

    A pathway from the natively unfolded microtubule-associated protein Tau to a highly structured amyloid fibril underlies human Tauopathies. This ordered assembly causes disease and represents the gain of toxic function. In recent years, evidence has accumulated to suggest that Tau inclusions form first in a small number of brain cells, from where they propagate to other regions, resulting in neurodegeneration and disease. Propagation of pathology is often called prion-like, which refers to the capacity of an assembled protein to induce the same abnormal conformation in a protein of the same kind, initiating a self-amplifying cascade. In addition, prion-like encompasses the release of protein aggregates from brain cells and their uptake by neighboring cells. In mice, the intracerebral injection of Tau inclusions induces the ordered assembly of monomeric Tau, followed by its spreading to distant brain regions. Conformational differences between Tau aggregates from transgenic mouse brain and in vitro assembled recombinant protein account for the greater seeding potency of brain aggregates. Short fibrils constitute the major species of seed-competent Tau in the brains of transgenic mice. The existence of multiple human Tauopathies with distinct fibril morphologies has led to the suggestion that different molecular conformers (or strains) of aggregated Tau exist.

  15. Aggregate Unemployment Decreases Individual Returns to Education

    Science.gov (United States)

    Ammermueller, Andreas; Kuckulenz, Anja; Zwick, Thomas

    2009-01-01

    Aggregate unemployment may affect individual returns to education through qualification-specific responses in participation and wage bargaining. This paper shows that an increase in regional unemployment by 1% decreases returns to education by 0.005 percentage points. This implies that higher skilled employees are better sheltered from labour…

  16. Assays for alpha-synuclein aggregation

    DEFF Research Database (Denmark)

    Giehm, Lise; Lorenzen, Nikolai; Otzen, Daniel

    2011-01-01

    leading to their formation is important for designing new drugs as well as in development of new nano-biomaterials such as nano-tubes, wires, scaffolds etc. 6. Understanding the process of amyloid formation requires an ability to reproduce this aggregation under controlled circumstances, in other words...

  17. Kinetics of fibrilar aggregation of food proteins

    NARCIS (Netherlands)

    Arnaudov, L.N.

    2005-01-01

    In this thesis we study the kinetics of fibrilar aggregation of two model proteins widely used in the food industry -b-lactoglobulin (b-lg) and hen

  18. Aggregation of MBP in chronic demyelination

    Science.gov (United States)

    Frid, Kati; Einstein, Ofira; Friedman-Levi, Yael; Binyamin, Orli; Ben-Hur, Tamir; Gabizon, Ruth

    2015-01-01

    Objectives Misfolding of key disease proteins to an insoluble state is associated with most neurodegenerative conditions, such as prion, Parkinson, and Alzheimer’s diseases. In this work, and by studying animal models of multiple sclerosis, we asked whether this is also the case for myelin basic protein (MBP) in the late and neurodegenerative phases of demyelinating diseases. Methods To this effect, we tested whether MBP, an essential myelin component, present prion-like properties in animal models of MS, as is the case for Cuprizone-induced chronic demyelination or chronic phases of Experimental Autoimmune Encephalomyelitis (EAE). Results We show here that while total levels of MBP were not reduced following extensive demyelination, part of these molecules accumulated thereafter as aggregates inside oligodendrocytes or around neuronal cells. In chronic EAE, MBP precipitated concomitantly with Tau, a marker of diverse neurodegenerative conditions, including MS. Most important, analysis of fractions from Triton X-100 floatation gradients suggest that the lipid composition of brain membranes in chronic EAE differs significantly from that of naïve mice, an effect which may relate to oxidative insults and subsequently prevent the appropriate insertion and compaction of new MBP in the myelin sheath, thereby causing its misfolding and aggregation. Interpretation Prion-like aggregation of MBP following chronic demyelination may result from an aberrant lipid composition accompanying this pathological status. Such aggregation of MBP may contribute to neuronal damage that occurs in the progressive phase of MS. PMID:26273684

  19. Spectrum Aggregation: initial outcomes from SAMURAI project

    DEFF Research Database (Denmark)

    Vivier, Guillame; Badic, Biljana; Cattoni, Andrea Fabio

    2011-01-01

    challenges. The SAMURAI project aims at investigating such challenges as well as at providing realistic performance results. This paper presents first outcomes of the project, with a specific focus of Carrier Aggregation (CA). Two aspects are discussed: CA at PHY/RF level with implementation challenges. Then...

  20. Internal water curing with Liapor aggregates

    DEFF Research Database (Denmark)

    Lura, Pietro

    2005-01-01

    Internal water curing is a very efficient way to counteract self-desiccation and autogenous shrinkage in high performance concrete, thereby reducing the likelihood of early-age cracking. This paper deals with early-age volume changes and moisture transport in lightweight aggregate concrete realiz...

  1. Studies of the aggregation of RNase Sa

    DEFF Research Database (Denmark)

    Khasa, Harshit; Kramer, Ryan; Maddux, Nathan

    2014-01-01

    Thirty-eight mutants of RNase Sa (ribonuclease from Streptomyces aureofaciens) were examined for their structure, thermal sensitivity, and tendency to aggregate. Although a biphasic correlation was seen between the effect of temperature on structure and the free energy of transfer changes in many...

  2. Aggregate Unemployment Decreases Individual Returns to Education

    Science.gov (United States)

    Ammermueller, Andreas; Kuckulenz, Anja; Zwick, Thomas

    2009-01-01

    Aggregate unemployment may affect individual returns to education through qualification-specific responses in participation and wage bargaining. This paper shows that an increase in regional unemployment by 1% decreases returns to education by 0.005 percentage points. This implies that higher skilled employees are better sheltered from labour…

  3. A discrete anisotropic model for Scheibe aggregates

    Directory of Open Access Journals (Sweden)

    O. Bang

    1991-05-01

    Full Text Available A discrete anisotropic nonlinear model for the dynamics of Scheibe aggregates is investigated. The collapse of the collective excitations found by Möbius and Kuhn is described as a shrinking ring wave, which is eventually absorbed by an acceptor molecule. An optimal acceptor loss is found.

  4. Thermodynamics of Micellization of Surfactants of Low Aggregation Number: The Aggregation of Propranolol Hydrochloride.

    Science.gov (United States)

    Mosquera; Ruso; Attwood; Jones; Prieto; Sarmiento

    1999-02-01

    The self-association of propranolol hydrochloride in aqueous solution has been studied as a function of temperature. The critical concentration (C*) and the degree of ionization (alpha) were determined by conductivity measurements at temperatures over the range 298.15 to 313.15 K. The enthalpy change on aggregation in water was measured by microcalorimetry. To calculate changes in the thermodynamic properties of aggregation the mass action model for high and low aggregation numbers was applied, the latter model giving better agreement between experimental and theoretical enthalpy changes. Copyright 1999 Academic Press.

  5. Ageing and hypoxia cause protein aggregation in mitochondria.

    Science.gov (United States)

    Kaufman, Daniel M; Wu, Xia; Scott, Barbara A; Itani, Omar A; Van Gilst, Marc R; Bruce, James E; Michael Crowder, C

    2017-10-01

    Aggregation of cytosolic proteins is a pathological finding in disease states, including ageing and neurodegenerative diseases. We have previously reported that hypoxia induces protein misfolding in Caenorhabditis elegans mitochondria, and electron micrographs suggested protein aggregates. Here, we seek to determine whether mitochondrial proteins actually aggregate after hypoxia and other cellular stresses. To enrich for mitochondrial proteins that might aggregate, we performed a proteomics analysis on purified C. elegans mitochondria to identify relatively insoluble proteins under normal conditions (110 proteins identified) or after sublethal hypoxia (65 proteins). A GFP-tagged mitochondrial protein (UCR-11 - a complex III electron transport chain protein) in the normally insoluble set was found to form widespread aggregates in mitochondria after hypoxia. Five other GFP-tagged mitochondrial proteins in the normally insoluble set similarly form hypoxia-induced aggregates. Two GFP-tagged mitochondrial proteins from the soluble set as well as a mitochondrial-targeted GFP did not form aggregates. Ageing also resulted in aggregates. The number of hypoxia-induced aggregates was regulated by the mitochondrial unfolded protein response (UPRmt) master transcriptional regulator ATFS-1, which has been shown to be hypoxia protective. An atfs-1(loss-of-function) mutant and RNAi construct reduced the number of aggregates while an atfs-1(gain-of-function) mutant increased aggregates. Our work demonstrates that mitochondrial protein aggregation occurs with hypoxic injury and ageing in C. elegans. The UPRmt regulates aggregation and may protect from hypoxia by promoting aggregation of misfolded proteins.

  6. Grade Skipping in Gifted Education

    Institute of Scientific and Technical Information of China (English)

    徐云婕

    2016-01-01

    Grade skipping has been heatedly discussed with the development of gifted education. Experts and scholars are trying to do ifnd out the better way to cultivate those gifted children, to develop their potential, and make full use of their talent. Although grade skipping has long history, there is no certain comment about whether it is beneiftial to the gifted children.

  7. Grade Inflation in Higher Education.

    Science.gov (United States)

    Ediger, Marlow

    The topic of grade inflation, the awarding of too many "A's" and "B's", is frequently mentioned in the literature on higher education. Many educational philosophies have suggested ways to evaluate students fairly. Some professors have used the bell-shaped curve as a model, giving grades according to the normal distribution curve regardless of the…

  8. Copper-triggered aggregation of ubiquitin.

    Science.gov (United States)

    Arnesano, Fabio; Scintilla, Simone; Calò, Vincenza; Bonfrate, Elena; Ingrosso, Chiara; Losacco, Maurizio; Pellegrino, Teresa; Rizzarelli, Enrico; Natile, Giovanni

    2009-09-16

    Neurodegenerative disorders share common features comprising aggregation of misfolded proteins, failure of the ubiquitin-proteasome system, and increased levels of metal ions in the brain. Protein aggregates within affected cells often contain ubiquitin, however no report has focused on the aggregation propensity of this protein. Recently it was shown that copper, differently from zinc, nickel, aluminum, or cadmium, compromises ubiquitin stability and binds to the N-terminus with 0.1 micromolar affinity. This paper addresses the role of copper upon ubiquitin aggregation. In water, incubation with Cu(II) leads to formation of spherical particles that can progress from dimers to larger conglomerates. These spherical oligomers are SDS-resistant and are destroyed upon Cu(II) chelation or reduction to Cu(I). In water/trifluoroethanol (80:20, v/v), a mimic of the local decrease in dielectric constant experienced in proximity to a membrane surface, ubiquitin incubation with Cu(II) causes time-dependent changes in circular dichroism and Fourier-transform infrared spectra, indicative of increasing beta-sheet content. Analysis by atomic force and transmission electron microscopy reveals, in the given order, formation of spherical particles consistent with the size of early oligomers detected by gel electrophoresis, clustering of these particles in straight and curved chains, formation of ring structures, growth of trigonal branches from the rings, coalescence of the trigonal branched structures in a network. Notably, none of these ubiquitin aggregates was positive to tests for amyloid and Cu(II) chelation or reduction produced aggregate disassembly. The early formed Cu(II)-stabilized spherical oligomers, when reconstituted in 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC) liposomes and in POPC planar bilayers, form annular and pore-like structures, respectively, which are common to several neurodegenerative disorders including Parkinson's, Alzheimer's, amyotrophic

  9. Copper-triggered aggregation of ubiquitin.

    Directory of Open Access Journals (Sweden)

    Fabio Arnesano

    Full Text Available Neurodegenerative disorders share common features comprising aggregation of misfolded proteins, failure of the ubiquitin-proteasome system, and increased levels of metal ions in the brain. Protein aggregates within affected cells often contain ubiquitin, however no report has focused on the aggregation propensity of this protein. Recently it was shown that copper, differently from zinc, nickel, aluminum, or cadmium, compromises ubiquitin stability and binds to the N-terminus with 0.1 micromolar affinity. This paper addresses the role of copper upon ubiquitin aggregation. In water, incubation with Cu(II leads to formation of spherical particles that can progress from dimers to larger conglomerates. These spherical oligomers are SDS-resistant and are destroyed upon Cu(II chelation or reduction to Cu(I. In water/trifluoroethanol (80:20, v/v, a mimic of the local decrease in dielectric constant experienced in proximity to a membrane surface, ubiquitin incubation with Cu(II causes time-dependent changes in circular dichroism and Fourier-transform infrared spectra, indicative of increasing beta-sheet content. Analysis by atomic force and transmission electron microscopy reveals, in the given order, formation of spherical particles consistent with the size of early oligomers detected by gel electrophoresis, clustering of these particles in straight and curved chains, formation of ring structures, growth of trigonal branches from the rings, coalescence of the trigonal branched structures in a network. Notably, none of these ubiquitin aggregates was positive to tests for amyloid and Cu(II chelation or reduction produced aggregate disassembly. The early formed Cu(II-stabilized spherical oligomers, when reconstituted in 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC liposomes and in POPC planar bilayers, form annular and pore-like structures, respectively, which are common to several neurodegenerative disorders including Parkinson's, Alzheimer

  10. Advancing the Power and Utility of Server-Side Aggregation

    Science.gov (United States)

    Fulker, Dave; Gallagher, James

    2016-01-01

    During the upcoming Summer 2016 meeting of the ESIP Federation (July 19-22), OpenDAP will hold a Developers and Users Workshop. While a broad set of topics will be covered, a key focus is capitalizing on recent EOSDIS-sponsored advances in Hyrax, OPeNDAPs own software for server-side realization of the DAP2 and DAP4 protocols. These Hyrax advances are as important to data users as to data providers, and the workshop will include hands-on experiences of value to both. Specifically, a balanced set of presentations and hands-on tutorials will address advances in1.server installation,2.server configuration,3.Hyrax aggregation capabilities,4.support for data-access from clients that are HTTP-based, JSON-based or OGC-compliant (especially WCS and WMS),5.support for DAP4,6.use and extension of server-side computational capabilities, and7.several performance-affecting matters.Topics 2 through 7 will be relevant to data consumers, data providers andnotably, due to the open-source nature of all OPeNDAP softwareto developers wishing to extend Hyrax, to build compatible clients and servers, andor to employ Hyrax as middleware that enables interoperability across a variety of end-user and source-data contexts. A session for contributed talks will elaborate the topics listed above and embrace additional ones.

  11. Open Payments Data

    Data.gov (United States)

    U.S. Department of Health & Human Services — Open Payments (otherwise known as the Sunshine Act) - Open Payments is a Congressionally-mandated transparency program that increases awareness of financial...

  12. Open Payments Data

    Data.gov (United States)

    U.S. Department of Health & Human Services — Open Payments (otherwise known as the Sunshine Act) - Open Payments is a Congressionally-mandated transparency program that increases awareness of financial...

  13. OpenCities Project

    Data.gov (United States)

    US Agency for International Development — The Open Cities Project aims to catalyze the creation, management and use of open data to produce innovative solutions for urban planning and resilience challenges...

  14. Practical problems in aggregating expert opinions

    Energy Technology Data Exchange (ETDEWEB)

    Booker, J.M.; Picard, R.R.; Meyer, M.A.

    1993-11-01

    Expert opinion is data given by a qualified person in response to a technical question. In these analyses, expert opinion provides information where other data are either sparse or non-existent. Improvements in forecasting result from the advantageous addition of expert opinion to observed data in many areas, such as meteorology and econometrics. More generally, analyses of large, complex systems often involve experts on various components of the system supplying input to a decision process; applications include such wide-ranging areas as nuclear reactor safety, management science, and seismology. For large or complex applications, no single expert may be knowledgeable enough about the entire application. In other problems, decision makers may find it comforting that a consensus or aggregation of opinions is usually better than a single opinion. Many risk and reliability studies require a single estimate for modeling, analysis, reporting, and decision making purposes. For problems with large uncertainties, the strategy of combining as diverse a set of experts as possible hedges against underestimation of that uncertainty. Decision makers are frequently faced with the task of selecting the experts and combining their opinions. However, the aggregation is often the responsibility of an analyst. Whether the decision maker or the analyst does the aggregation, the input for it, such as providing weights for experts or estimating other parameters, is imperfect owing to a lack of omniscience. Aggregation methods for expert opinions have existed for over thirty years; yet many of the difficulties with their use remain unresolved. The bulk of these problem areas are summarized in the sections that follow: sensitivities of results to assumptions, weights for experts, correlation of experts, and handling uncertainties. The purpose of this paper is to discuss the sources of these problems and describe their effects on aggregation.

  15. Article Processing Charges and OpenAPC

    CERN Document Server

    CERN. Geneva

    2017-01-01

    The publication landscape is about to change. While being largely operated by subscription based journals in the past, recent political decisions force the publishing industry towards OpenAccess. Especially, the publication of the Finch report in 2012 put APC based Gold OpenAccess models almost everywhere on the agenda. These models also require quite some adoptions for library work flows to handle payments, bills and centralized funds for publication fees. Sometimes handled in specialized systems (e.g. first setups in Jülich) pretty early on discussions started to handle APCs in local repositories which would also hold the OpenAccess content resulting from these fees, e.g. the University of Regenburg uses ePrints for this purpose. Backed up by the OpenData movmement, libraries also saw opportunity to exchange data about fees payed. Thus, OpenAPC.de was born in 2014 on github to facilitate this exchange and aggregate large amounts of data for evaluation and comparison. Using the repository to hold payment d...

  16. Open Hardware Business Models

    Directory of Open Access Journals (Sweden)

    Edy Ferreira

    2008-04-01

    Full Text Available In the September issue of the Open Source Business Resource, Patrick McNamara, president of the Open Hardware Foundation, gave a comprehensive introduction to the concept of open hardware, including some insights about the potential benefits for both companies and users. In this article, we present the topic from a different perspective, providing a classification of market offers from companies that are making money with open hardware.

  17. Small file aggregation in a parallel computing system

    Science.gov (United States)

    Faibish, Sorin; Bent, John M.; Tzelnic, Percy; Grider, Gary; Zhang, Jingwang

    2014-09-02

    Techniques are provided for small file aggregation in a parallel computing system. An exemplary method for storing a plurality of files generated by a plurality of processes in a parallel computing system comprises aggregating the plurality of files into a single aggregated file; and generating metadata for the single aggregated file. The metadata comprises an offset and a length of each of the plurality of files in the single aggregated file. The metadata can be used to unpack one or more of the files from the single aggregated file.

  18. Open Source Business Solutions

    Directory of Open Access Journals (Sweden)

    Ion IVAN

    2008-01-01

    Full Text Available This analyses the Open source movement. Open source development process and management is seen different from the classical point of view. This focuses on characteristics and software market tendencies for the main Open source initiatives. It also points out the labor market future evolution for the software developers.

  19. OpenFlow cookbook

    CERN Document Server

    Smiler S, Kingston

    2015-01-01

    This book is intended for network protocol developers, SDN controller application developers, and academics who would like to understand and develop their own OpenFlow switch or OpenFlow controller in any programming language. With basic understanding of OpenFlow and its components, you will be able to follow the recipes in this book.

  20. Open Rotor Development

    Science.gov (United States)

    Van Zante, Dale E.; Rizzi, Stephen A.

    2016-01-01

    The ERA project executed a comprehensive test program for Open Rotor aerodynamic and acoustic performance. System studies used the data to estimate the fuel burn savings and acoustic margin for an aircraft system with open rotor propulsion. The acoustic measurements were used to produce an auralization that compares the legacy blades to the current generation of open rotor designs.