Science.gov

Sample records for acid base accounting

  1. ACID-BASE ACCOUNT EFFECTIVENESS FOR DETERMINATION OF MINE WASTE POTENTIAL ACIDITY. (R825549C048)

    EPA Science Inventory

    The oxidation of sulfide minerals in mine waste is a widespread source of resource degradation, often resulting in the generation of acidic water and mobilization of heavy metals. The quantity of acid forming minerals present in mine waste, dominantly as pyrite (FeS2

  2. Effects of storm runoff on acid-base accounting of mine drainage

    SciTech Connect

    Sjoegren, D.R.; Olyphant, G.A.; Harper, D.

    1997-12-31

    Pre-reclamation conditions were documented at an abandoned mine site in an upland area at the headwaters of a small perennial stream in southwestern Indiana. Stream discharge and chemistry were monitored from April to October 1995, in an effort to assess the total acid-base budget of outflows from the site. The chemistry of three lakes, a shallow aquifer, and flooded mine voids was also monitored. During the period of monitoring, thirty-five rainfall-runoff events occurred, producing a total storm discharge of approximately 6.12 x 10{sup 7} L. Baseflow during the monitoring period was approximately 1.10 x 10{sup 8} L and was characterized by water chemistry that was similar to that of a spring that issued from the flooded mine voids. Analysis of the discharge and chemistry associated with an isolated thunderstorm revealed fluctuations in acidity that were not congruent with fluctuations in the total discharge hydrograph. For example, acidity increased rapidly during the initial phase of hydrograph rise, but dropped significantly as the storm hydrograph peaked. A second, more subdued, rise in acidity occurred during a second rain pulse, and the acidity gradually decreased to pre-storm levels during hydrograph recession. The trends are interpreted to reflect different sources of storm runoff associated with various components of the total discharge hydrograph. Preliminary calculations indicate that the total quantity of acidity that is discharged during stormflow is about eight times higher than that which is discharged during a comparable period under baseflow conditions. While the lower acid concentrations generated during storm events are ecologically favorable, the increase in total quantities of acidity can have implications for the buffering capacities of receiving water bodies.

  3. School Centered Evidence Based Accountability

    ERIC Educational Resources Information Center

    Milligan, Charles

    2015-01-01

    Achievement scores drive much of the effort in today's accountability system, however, there is much more that occurs in every school, every day. School Centered Evidence Based Accountability can be used from micro to macro giving School Boards and Administration a process for monitoring the results of the entire school operation effectively and…

  4. [Stewart's acid-base approach].

    PubMed

    Funk, Georg-Christian

    2007-01-01

    In addition to paCO(2), Stewart's acid base model takes into account the influence of albumin, inorganic phosphate, electrolytes and lactate on acid-base equilibrium. It allows a comprehensive and quantitative analysis of acid-base disorders. Particularly simultaneous and mixed metabolic acid-base disorders, which are common in critically ill patients, can be assessed. Stewart's approach is therefore a valuable tool in addition to the customary acid-base approach based on bicarbonate or base excess. However, some chemical aspects of Stewart's approach remain controversial.

  5. Restorative Justice as Strength-Based Accountability

    ERIC Educational Resources Information Center

    Ball, Robert

    2003-01-01

    This article compares strength-based and restorative justice philosophies for young people and their families. Restorative justice provides ways to respond to crime and harm that establish accountability while seeking to reconcile members of a community. Restorative approaches are an important subset of strength-based interventions.

  6. Problem-Based Learning in Accounting

    ERIC Educational Resources Information Center

    Dockter, DuWayne L.

    2012-01-01

    Seasoned educators use an assortment of student-centered methods and tools to enhance their student's learning environment. In respects to methodologies used in accounting, educators have utilized and created new forms of problem-based learning exercises, including case studies, simulations, and other projects, to help students become more active…

  7. Standards-Based Accountability in South Africa

    ERIC Educational Resources Information Center

    Taylor, Nick

    2009-01-01

    The implementation of standards-based accountability (SBA) interventions aimed at improving school performance often focuses on the testing component, at the expense of capacity building. This was the case in South Africa when a SBA programme was instituted by government in 2000, which was accompanied by substantial rises in senior certificate…

  8. Arkansas' Curriculum Guide. Competency Based Computerized Accounting.

    ERIC Educational Resources Information Center

    Arkansas State Dept. of Education, Little Rock. Div. of Vocational, Technical and Adult Education.

    This guide contains the essential parts of a total curriculum for a one-year secondary-level course in computerized accounting. Addressed in the individual sections of the guide are the following topics: the complete accounting cycle, computer operations for accounting, computerized accounting and general ledgers, computerized accounts payable,…

  9. Trade-based carbon sequestration accounting.

    PubMed

    King, Dennis M

    2004-04-01

    This article describes and illustrates an accounting method to assess and compare "early" carbon sequestration investments and trades on the basis of the number of standardized CO2 emission offset credits they will provide. The "gold standard" for such credits is assumed to be a relatively riskless credit based on a CO2 emission reduction that provides offsets against CO2 emissions on a one-for-one basis. The number of credits associated with carbon sequestration needs to account for time, risk, durability, permanence, additionality, and other factors that future trade regulators will most certainly use to assign "official" credits to sequestration projects. The method that is presented here uses established principles of natural resource accounting and conventional rules of asset valuation to "score" projects. A review of 20 "early" voluntary United States based CO2 offset trades that involve carbon sequestration reveals that the assumptions that buyers, sellers, brokers, and traders are using to characterize the economic potential of their investments and trades vary enormously. The article develops a "universal carbon sequestration credit scoring equation" and uses two of these trades to illustrate the sensitivity of trade outcomes to various assumptions about how future trade auditors are likely to "score" carbon sequestration projects in terms of their "equivalency" with CO2 emission reductions. The article emphasizes the importance of using a standard credit scoring method that accounts for time and risk to assess and compare even unofficial prototype carbon sequestration trades. The scoring method illustrated in this article is a tool that can protect the integrity of carbon sequestration credit trading and can assist buyers and sellers in evaluating the real economic potential of prospective trades.

  10. Accountability.

    ERIC Educational Resources Information Center

    Lashway, Larry

    1999-01-01

    This issue reviews publications that provide a starting point for principals looking for a way through the accountability maze. Each publication views accountability differently, but collectively these readings argue that even in an era of state-mandated assessment, principals can pursue proactive strategies that serve students' needs. James A.…

  11. 12 CFR 563b.465 - Do account holders retain any voting rights based on their liquidation sub-accounts?

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... based on their liquidation sub-accounts? 563b.465 Section 563b.465 Banks and Banking OFFICE OF THRIFT... Account § 563b.465 Do account holders retain any voting rights based on their liquidation sub-accounts... their liquidation sub-accounts....

  12. Accountability for Project-Based Collaborative Learning

    ERIC Educational Resources Information Center

    Jamal, Abu-Hussain; Essawi, Mohammad; Tilchin, Oleg

    2014-01-01

    One perspective model for the creation of the learning environment and engendering students' thinking development is the Project-Based Collaborative Learning (PBCL) model. This model organizes learning by collaborative performance of various projects. In this paper we describe an approach to enhancing the PBCL model through the creation of…

  13. Test-Based Teacher Evaluations: Accountability vs. Responsibility

    ERIC Educational Resources Information Center

    Bolyard, Chloé

    2015-01-01

    Gert Biesta contends that managerial accountability, which focuses on efficiency and competition, dominates the current political arena in education. Such accountability has influenced states' developments of test-based teacher evaluations in an attempt to quantify teachers' efficacy on student learning. With numerous state policies requiring the…

  14. Student Accountability in Team-Based Learning Classes

    ERIC Educational Resources Information Center

    Stein, Rachel E.; Colyer, Corey J.; Manning, Jason

    2016-01-01

    Team-based learning (TBL) is a form of small-group learning that assumes stable teams promote accountability. Teamwork promotes communication among members; application exercises promote active learning. Students must prepare for each class; failure to do so harms their team's performance. Therefore, TBL promotes accountability. As part of the…

  15. Risk-Based Educational Accountability in Dutch Primary Education

    ERIC Educational Resources Information Center

    Timmermans, A. C.; de Wolf, I. F.; Bosker, R. J.; Doolaard, S.

    2015-01-01

    A recent development in educational accountability is a risk-based approach, in which intensity and frequency of school inspections vary across schools to make educational accountability more efficient and effective by enabling inspectorates to focus on organizations at risk. Characteristics relevant in predicting which schools are "at risk…

  16. Financial Accounting System Based Upon NCES Revised Handbook II.

    ERIC Educational Resources Information Center

    National Center for Education Statistics (DHEW), Washington, DC. Educational Data Standards Branch.

    This publication describes the development and implementation of a school district financial accounting system based on the concepts and guidelines of the National Center for Education Statistics Handbook II, Revised. The system described was designed by school district personnel to utilize computer equipment and to meet the accounting and…

  17. Account-based plans curb costs and engage employees.

    PubMed

    Osterndorf, Dave

    2006-01-01

    A growing number of organizations are combining consumer-driven health plans with account-based approaches in order to limit health benefit costs, reinforce key consumerist messages and provide meaningful benefits to both actives and retirees. This article describes how account-based approaches work and can be used to motivate employees to invest in their health today and salt away funds for tomorrow. The author describes what employers can do to ensure that consumer-driven health plans and account-based approaches help employees accomplish their goals.

  18. Whole body acid-base modeling revisited.

    PubMed

    Ring, Troels; Nielsen, Søren

    2017-04-01

    The textbook account of whole body acid-base balance in terms of endogenous acid production, renal net acid excretion, and gastrointestinal alkali absorption, which is the only comprehensive model around, has never been applied in clinical practice or been formally validated. To improve understanding of acid-base modeling, we managed to write up this conventional model as an expression solely on urine chemistry. Renal net acid excretion and endogenous acid production were already formulated in terms of urine chemistry, and we could from the literature also see gastrointestinal alkali absorption in terms of urine excretions. With a few assumptions it was possible to see that this expression of net acid balance was arithmetically identical to minus urine charge, whereby under the development of acidosis, urine was predicted to acquire a net negative charge. The literature already mentions unexplained negative urine charges so we scrutinized a series of seminal papers and confirmed empirically the theoretical prediction that observed urine charge did acquire negative charge as acidosis developed. Hence, we can conclude that the conventional model is problematic since it predicts what is physiologically impossible. Therefore, we need a new model for whole body acid-base balance, which does not have impossible implications. Furthermore, new experimental studies are needed to account for charge imbalance in urine under development of acidosis.

  19. The Impact of a Participant-Based Accounting Cycle Course on Student Performance in Intermediate Financial Accounting I

    ERIC Educational Resources Information Center

    Siagian, Ferdinand T.; Khan, Mohammad

    2016-01-01

    The authors investigated whether students in an Intermediate Financial Accounting I course who took a 1-credit, participant-based accounting cycle course performed better than students who did not take the accounting cycle course. Results indicate a higher likelihood of earning a better grade for students who took the accounting cycle course even…

  20. The utilization of activity-based cost accounting in hospitals.

    PubMed

    Emmett, Dennis; Forget, Robert

    2005-01-01

    Healthcare costs are being examined on all fronts. Healthcare accounts for 11% of the gross national product and will continue to rise as the "babyboomers" reach retirement age. While ascertaining costs is important, most research shows that costing methods have not been implemented in hospitals. This study is concerned with the use of costing methods; particularly activity-based cost accounting. A mail survey of CFOs was undertaken to determine the type of cost accounting method they use. In addition, they were asked whether they were aware of activity-based cost accounting and whether they had implemented it or were planning to implement it. Only 71.8% were aware of it and only 4.7% had implemented it. In addition, only 52% of all hospitals report using any cost accounting systems. Education needs to ensure that all healthcare executives are cognizant of activity-based accounting and its importance in determining costs. Only by determining costs can hospitals strive to contain them.

  1. Knuckling Under? School Superintendents and Accountability-Based Educational Reform

    ERIC Educational Resources Information Center

    Feuerstein, Abe

    2013-01-01

    The goal of this article is to explore the various ways that superintendents have responded to accountability-based educational reform efforts such as No Child Left Behind, the factors that have influenced their responses, and the implications of these responses for current and future educational leaders. With respect to the first issue, empirical…

  2. Digital Game-Based Learning in Accounting and Business Education

    ERIC Educational Resources Information Center

    Carenys, Jordi; Moya, Soledad

    2016-01-01

    This article presents a review of the accounting and business literature on digital game-based learning (DGBL). The article classifies what is already settled in the literature about the theoretical foundations of DGBL's effectiveness and its practical use into three categories. The first comprises what is known about the evaluation of digital…

  3. Performance-Based Accountability in Qatar: A State in Progress

    ERIC Educational Resources Information Center

    Jaafar, Sonia Ben

    2011-01-01

    It has become a normative practice to include Performance-Based Accountability (PBA) policies in educational reforms to foster school changes that enhance student learning and success. There is considerable variation in PBA models that have an important impact on how they operate in schools. It is, therefore, important to characterize PBA models…

  4. Ontology-Based e-Assessment for Accounting Education

    ERIC Educational Resources Information Center

    Litherland, Kate; Carmichael, Patrick; Martínez-García, Agustina

    2013-01-01

    This summary reports on a pilot of a novel, ontology-based e-assessment system in accounting. The system, OeLe, uses emerging semantic technologies to offer an online assessment environment capable of marking students' free text answers to questions of a conceptual nature. It does this by matching their response with a "concept map" or…

  5. Water Accounting Plus (WA+) - a water accounting procedure for complex river basins based on satellite measurements

    NASA Astrophysics Data System (ADS)

    Karimi, P.; Bastiaanssen, W. G. M.; Molden, D.

    2012-11-01

    Coping with the issue of water scarcity and growing competition for water among different sectors requires proper water management strategies and decision processes. A pre-requisite is a clear understanding of the basin hydrological processes, manageable and unmanageable water flows, the interaction with land use and opportunities to mitigate the negative effects and increase the benefits of water depletion on society. Currently, water professionals do not have a common framework that links hydrological flows to user groups of water and their benefits. The absence of a standard hydrological and water management summary is causing confusion and wrong decisions. The non-availability of water flow data is one of the underpinning reasons for not having operational water accounting systems for river basins in place. In this paper we introduce Water Accounting Plus (WA+), which is a new framework designed to provide explicit spatial information on water depletion and net withdrawal processes in complex river basins. The influence of land use on the water cycle is described explicitly by defining land use groups with common characteristics. Analogous to financial accounting, WA+ presents four sheets including (i) a resource base sheet, (ii) a consumption sheet, (iii) a productivity sheet, and (iv) a withdrawal sheet. Every sheet encompasses a set of indicators that summarize the overall water resources situation. The impact of external (e.g. climate change) and internal influences (e.g. infrastructure building) can be estimated by studying the changes in these WA+ indicators. Satellite measurements can be used for 3 out of the 4 sheets, but is not a precondition for implementing WA+ framework. Data from hydrological models and water allocation models can also be used as inputs to WA+.

  6. Ecological accounting based on extended exergy: a sustainability perspective.

    PubMed

    Dai, Jing; Chen, Bin; Sciubba, Enrico

    2014-08-19

    The excessive energy consumption, environmental pollution, and ecological destruction problems have gradually become huge obstacles for the development of societal-economic-natural complex ecosystems. Regarding the national ecological-economic system, how to make explicit the resource accounting, diagnose the resource conversion, and measure the disturbance of environmental emissions to the systems are the fundamental basis of sustainable development and coordinated management. This paper presents an extended exergy (EE) accounting including the material exergy and exergy equivalent of externalities consideration in a systematic process from production to consumption, and China in 2010 is chosen as a case study to foster an in-depth understanding of the conflict between high-speed development and the available resources. The whole society is decomposed into seven sectors (i.e., Agriculture, Extraction, Conversion, Industry, Transportation, Tertiary, and Domestic sectors) according to their distinct characteristics. An adaptive EE accounting database, which incorporates traditional energy, renewable energy, mineral element, and other natural resources as well as resource-based secondary products, is constructed on the basis of the internal flows in the system. In addition, the environmental emission accounting has been adjusted to calculate the externalities-equivalent exergy. The results show that the EE value for the year 2010 in China was 1.80 × 10(14) MJ, which is greatly increased. Furthermore, an EE-based sustainability indices system has been established to provide an epitomized exploration for evaluating the performance of flows and storages with the system from a sustainability perspective. The value of the EE-based sustainability indicator was calculated to be 0.23, much lower than the critical value of 1, implying that China is still developing in the stages of high energy consumption and a low sustainability level.

  7. Consumption-based accounting of CO2 emissions

    PubMed Central

    Davis, Steven J.; Caldeira, Ken

    2010-01-01

    CO2 emissions from the burning of fossil fuels are the primary cause of global warming. Much attention has been focused on the CO2 directly emitted by each country, but relatively little attention has been paid to the amount of emissions associated with the consumption of goods and services in each country. Consumption-based accounting of CO2 emissions differs from traditional, production-based inventories because of imports and exports of goods and services that, either directly or indirectly, involve CO2 emissions. Here, using the latest available data, we present a global consumption-based CO2 emissions inventory and calculations of associated consumption-based energy and carbon intensities. We find that, in 2004, 23% of global CO2 emissions, or 6.2 gigatonnes CO2, were traded internationally, primarily as exports from China and other emerging markets to consumers in developed countries. In some wealthy countries, including Switzerland, Sweden, Austria, the United Kingdom, and France, >30% of consumption-based emissions were imported, with net imports to many Europeans of >4 tons CO2 per person in 2004. Net import of emissions to the United States in the same year was somewhat less: 10.8% of total consumption-based emissions and 2.4 tons CO2 per person. In contrast, 22.5% of the emissions produced in China in 2004 were exported, on net, to consumers elsewhere. Consumption-based accounting of CO2 emissions demonstrates the potential for international carbon leakage. Sharing responsibility for emissions among producers and consumers could facilitate international agreement on global climate policy that is now hindered by concerns over the regional and historical inequity of emissions. PMID:20212122

  8. Consumption-based accounting of CO2 emissions.

    PubMed

    Davis, Steven J; Caldeira, Ken

    2010-03-23

    CO(2) emissions from the burning of fossil fuels are the primary cause of global warming. Much attention has been focused on the CO(2) directly emitted by each country, but relatively little attention has been paid to the amount of emissions associated with the consumption of goods and services in each country. Consumption-based accounting of CO(2) emissions differs from traditional, production-based inventories because of imports and exports of goods and services that, either directly or indirectly, involve CO(2) emissions. Here, using the latest available data, we present a global consumption-based CO(2) emissions inventory and calculations of associated consumption-based energy and carbon intensities. We find that, in 2004, 23% of global CO(2) emissions, or 6.2 gigatonnes CO(2), were traded internationally, primarily as exports from China and other emerging markets to consumers in developed countries. In some wealthy countries, including Switzerland, Sweden, Austria, the United Kingdom, and France, >30% of consumption-based emissions were imported, with net imports to many Europeans of >4 tons CO(2) per person in 2004. Net import of emissions to the United States in the same year was somewhat less: 10.8% of total consumption-based emissions and 2.4 tons CO(2) per person. In contrast, 22.5% of the emissions produced in China in 2004 were exported, on net, to consumers elsewhere. Consumption-based accounting of CO(2) emissions demonstrates the potential for international carbon leakage. Sharing responsibility for emissions among producers and consumers could facilitate international agreement on global climate policy that is now hindered by concerns over the regional and historical inequity of emissions.

  9. An Internet-Based Accounting Information Systems Project

    ERIC Educational Resources Information Center

    Miller, Louise

    2012-01-01

    This paper describes a student project assignment used in an accounting information systems course. We are now truly immersed in the internet age, and while many required accounting information systems courses and textbooks introduce database design, accounting software development, cloud computing, and internet security, projects involving the…

  10. Acid-base homeostasis in the human system

    NASA Technical Reports Server (NTRS)

    White, R. J.

    1974-01-01

    Acid-base regulation is a cooperative phenomena in vivo with body fluids, extracellular and intracellular buffers, lungs, and kidneys all playing important roles. The present account is much too brief to be considered a review of present knowledge of these regulatory systems, and should be viewed, instead, as a guide to the elements necessary to construct a simple model of the mutual interactions of the acid-base regulatory systems of the body.

  11. Nucleic acid based logical systems.

    PubMed

    Han, Da; Kang, Huaizhi; Zhang, Tao; Wu, Cuichen; Zhou, Cuisong; You, Mingxu; Chen, Zhuo; Zhang, Xiaobing; Tan, Weihong

    2014-05-12

    Researchers increasingly visualize a significant role for artificial biochemical logical systems in biological engineering, much like digital logic circuits in electrical engineering. Those logical systems could be utilized as a type of servomechanism to control nanodevices in vitro, monitor chemical reactions in situ, or regulate gene expression in vivo. Nucleic acids (NA), as carriers of genetic information with well-regulated and predictable structures, are promising materials for the design and engineering of biochemical circuits. A number of logical devices based on nucleic acids (NA) have been designed to handle various processes for technological or biotechnological purposes. This article focuses on the most recent and important developments in NA-based logical devices and their evolution from in vitro, through cellular, even towards in vivo biological applications.

  12. Integrating Mission-Based Values into Accounting Curriculum: Catholic Social Teaching and Introductory Accounting

    ERIC Educational Resources Information Center

    Hise, Joan Vane; Koeplin, John P.

    2010-01-01

    This paper presents several reasons why mission-based values, in this case Catholic Social Teaching (CST), should be incorporated into a university business curriculum. The CST tenets include the sanctity of human life; call to family, community, and participation; rights and responsibilities; option for the poor and vulnerable; the dignity of…

  13. Accounting Faculty Utilization of Web-Based Resources to Enhance In-Class Instruction

    ERIC Educational Resources Information Center

    Black, Thomas G.; Turetsky, Howard F.

    2010-01-01

    Our study examines the extent to which accounting faculty use web-based resources to augment classroom instruction. Moreover, we explore the effects of the institutional factors of accounting accreditation and the existence of an accounting Ph.D. program on internet use by accounting academics toward enhancing pedagogy, while controlling for the…

  14. The Acid-Base Titration of a Very Weak Acid: Boric Acid

    ERIC Educational Resources Information Center

    Celeste, M.; Azevedo, C.; Cavaleiro, Ana M. V.

    2012-01-01

    A laboratory experiment based on the titration of boric acid with strong base in the presence of d-mannitol is described. Boric acid is a very weak acid and direct titration with NaOH is not possible. An auxiliary reagent that contributes to the release of protons in a known stoichiometry facilitates the acid-base titration. Students obtain the…

  15. Designing Rules for Accounting Transaction Identification based on Indonesian NLP

    NASA Astrophysics Data System (ADS)

    Iswandi, I.; Suwardi, I. S.; Maulidevi, N. U.

    2017-03-01

    Recording accounting transactions carried out by the evidence of the transactions. It can be invoices, receipts, letters of intent, electricity bill, telephone bill, etc. In this paper, we proposed design of rules to identify the entities located on the sales invoice. There are some entities identified in a sales invoice, namely : invoice date, company name, invoice number, product id, product name, quantity and total price. Identification this entities using named entity recognition method. The entities generated from the rules used as a basis for automation process of data input into the accounting system.

  16. Accounting Control Technology Using SAP: A Case-Based Approach

    ERIC Educational Resources Information Center

    Ragan, Joseph; Puccio, Christopher; Talisesky, Brandon

    2014-01-01

    The Sarbanes-Oxley Act (SOX) revolutionized the accounting and audit industry. The use of preventative and process controls to evaluate the continuous audit process done via an SAP ERP ECC 6.0 system is key to compliance with SOX and managing costs. This paper can be used in a variety of ways to discuss issues associated with auditing and testing…

  17. 26 CFR 1.801-8 - Contracts with reserves based on segregated asset accounts.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... short-term capital losses of $10,000 attributable to its general asset accounts and realized short-term... based on a segregated asset account. (i) For purposes of part I, section 801(g)(1)(B) defines the term...) The term contract with reserves based on a segregated asset account includes a contract such as...

  18. Accounting for the Torsional Splitting in the ν 5 and 2ν 9 Bands of Nitric Acid

    NASA Astrophysics Data System (ADS)

    Coudert, L. H.; Perrin, A.

    1995-08-01

    In an attempt to account for the large-amplitude torsional ν9 mode of nitric acid, a formalism is set up, based on an internal-axis-method-like approach previously developed for high-barrier tunneling problems. This formalism is applied to the calculation of the tunneling-rotational-vibrational energy of the interacting ν9 = 2 and ν5 = 1 vibrational states and accounts for the relational dependence of the tunneling splitting and for the strong Coriolis and Fermi resonances between these two vibrational states. With the help of this formalism, it is shown that the effects of the large-amplitude motion may be very different depending on the way the rotational states are clustered. For large Ka values, shifts of about 0.001 cm-1 are predicted, while splittings of roughly the same value occur for large Kc values. This formalism is used to carry out a simultaneous analysis of the microwave data relevant to the two vibrational states (Goyette et al., J. Mol. Spectrosc.167, 365-374, 1994) and of the infrared transitions belonging to the 2ν9 and ν5 bands (Perrin et al., J. Mol. Spectrosc.157, 112-121, 1993). The frequency of the microwave transitions and the wavenumber of the infrared transitions are satisfactorily reproduced and it is possible to point out the effects of the large-amplitude motion in the latter data set.

  19. Meeting Performance-based Training Demands: Accountability in an Intervention-based Practicum.

    ERIC Educational Resources Information Center

    Barnett, David W.; Daly III, Edward J.; Hampshire, Ellen M.; Hines, Nancy Rovak; Maples, Kelly A.; Ostrom, Jennifer K.; Van Buren, Amy E.

    1999-01-01

    Describes accountability methods built into practicums for school psychology trainees. Results of intervention-based services were summed across individual cases developed by trainees as a means of examining the overall effectiveness of the practicum experiences. Outcomes are reported as procedural adherence to the model of service delivery,…

  20. Australian Rural Accountants' Views on How Locally Provided CPD Compares with City-Based Provision

    ERIC Educational Resources Information Center

    Halabi, Abdel K.

    2015-01-01

    This paper analyses Australian rural accountants' attitudes and levels of satisfaction with continuing professional development (CPD), based on whether the CPD was delivered by a professional accounting body in a rural or metropolitan area. The paper responds to prior research that finds rural accountants are dissatisfied with professional…

  1. A formal ideal-based account of typicality.

    PubMed

    Voorspoels, Wouter; Vanpaemel, Wolf; Storms, Gert

    2011-10-01

    Inspired by Barsalou's (Journal of Experimental Psychology: Learning, Memory, and Cognition, 11, 629-654, 1985) proposal that categories can be represented by ideals, we develop and test a computational model, the ideal dimension model (IDM). The IDM is tested in its account of the typicality gradient for 11 superordinate natural language concepts and, using Bayesian model evaluation, contrasted with a standard exemplar model and a central prototype model. The IDM is found to capture typicality better than do the exemplar model and the central tendency prototype model, in terms of both goodness of fit and generalizability. The present findings challenge the dominant view that exemplar representations are most successful and present compelling evidence that superordinate natural language categories can be represented using an abstract summary, in the form of ideal representations. Supplemental appendices for this article can be downloaded from http://mc.psychonomic-journals.org/content/supplemental.

  2. 26 CFR 1.801-8 - Contracts with reserves based on segregated asset accounts.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 26 Internal Revenue 8 2014-04-01 2014-04-01 false Contracts with reserves based on segregated... Contracts with reserves based on segregated asset accounts. (a) Definitions—(1) Annuity contracts include...) defines the term contract with reserves based on a segregated asset account as a contract (individual...

  3. 26 CFR 1.801-8 - Contracts with reserves based on segregated asset accounts.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 26 Internal Revenue 8 2012-04-01 2012-04-01 false Contracts with reserves based on segregated... Contracts with reserves based on segregated asset accounts. (a) Definitions—(1) Annuity contracts include...) defines the term contract with reserves based on a segregated asset account as a contract (individual...

  4. 26 CFR 1.801-8 - Contracts with reserves based on segregated asset accounts.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 26 Internal Revenue 8 2013-04-01 2013-04-01 false Contracts with reserves based on segregated... Contracts with reserves based on segregated asset accounts. (a) Definitions—(1) Annuity contracts include...) defines the term contract with reserves based on a segregated asset account as a contract (individual...

  5. Accountability to Public Stakeholders in Watershed-Based Restoration

    EPA Science Inventory

    There is an increasing push at the federal, state, and local levels for watershed-based conservation projects. These projects work to address water quality issues in degraded waterways through the implementation of a suite of best management practices on land throughout a watersh...

  6. School-Based Budgets: Getting, Spending, and Accounting.

    ERIC Educational Resources Information Center

    Herman, Jerry L.; Herman, Janice L.

    With the advent of large interest in school-based management came the task of inventing a different type of budgeting system--one that delegated the many tasks of developing a budget, expending the allocated funds, and controlling those expenditures in a way that did not exceed the allocation to the site level. This book explores the various means…

  7. One Paradox in District Accountability and Site-Based Management.

    ERIC Educational Resources Information Center

    Shellman, David W.

    The paradox of site-based school management with use of standardized tests or instructional management systems that restrict teacher choices was evident in one school district in North Carolina in which measurement of student success has centered on student performance on state-mandated tests. A study was conducted to see if students whose…

  8. Students' Concern about Indebtedness: A Rank Based Social Norms Account

    ERIC Educational Resources Information Center

    Aldrovandi, Silvio; Wood, Alex M.; Maltby, John; Brown, Gordon D. A.

    2015-01-01

    This paper describes a new model of students' concern about indebtedness within a rank-based social norms framework. Study 1 found that students hold highly variable beliefs about how much other students will owe at the end of their degree. Students' concern about their own anticipated debt--and their intention of taking on a part-time job during…

  9. Performance-Based Measurement: Action for Organizations and HPT Accountability

    ERIC Educational Resources Information Center

    Larbi-Apau, Josephine A.; Moseley, James L.

    2010-01-01

    Basic measurements and applications of six selected general but critical operational performance-based indicators--effectiveness, efficiency, productivity, profitability, return on investment, and benefit-cost ratio--are presented. With each measurement, goals and potential impact are explored. Errors, risks, limitations to measurements, and a…

  10. Phosphonic acid based exchange resins

    DOEpatents

    Horwitz, E.P.; Alexandratos, S.D.; Gatrone, R.C.; Chiarizia, R.

    1995-09-12

    An ion exchange resin is described for extracting metal ions from a liquid waste stream. An ion exchange resin is prepared by copolymerizing a vinylidene diphosphonic acid with styrene, acrylonitrile and divinylbenzene. 10 figs.

  11. Phosphonic acid based exchange resins

    DOEpatents

    Horwitz, E. Philip; Alexandratos, Spiro D.; Gatrone, Ralph C.; Chiarizia, Ronato

    1995-01-01

    An ion exchange resin for extracting metal ions from a liquid waste stream. An ion exchange resin is prepared by copolymerizing a vinylidene diphosphonic acid with styrene, acrylonitrile and divinylbenzene.

  12. The Conjugate Acid-Base Chart.

    ERIC Educational Resources Information Center

    Treptow, Richard S.

    1986-01-01

    Discusses the difficulties that beginning chemistry students have in understanding acid-base chemistry. Describes the use of conjugate acid-base charts in helping students visualize the conjugate relationship. Addresses chart construction, metal ions, buffers and pH titrations, and the organic functional groups and nonaqueous solvents. (TW)

  13. Students' Alternate Conceptions on Acids and Bases

    ERIC Educational Resources Information Center

    Pan, Hanqing; Henriques, Laura

    2015-01-01

    Knowing what students bring to the classroom can and should influence how we teach them. This study is a review of the literature associated with secondary and postsecondary students' ideas about acids and bases. It was found that there are six types of alternate ideas about acids and bases that students hold. These are: macroscopic properties of…

  14. The Kidney and Acid-Base Regulation

    ERIC Educational Resources Information Center

    Koeppen, Bruce M.

    2009-01-01

    Since the topic of the role of the kidneys in the regulation of acid base balance was last reviewed from a teaching perspective (Koeppen BM. Renal regulation of acid-base balance. Adv Physiol Educ 20: 132-141, 1998), our understanding of the specific membrane transporters involved in H+, HCO , and NH transport, and especially how these…

  15. Test-Based Accountability: Potential Benefits and Pitfalls of Science Assessment with Student Diversity

    ERIC Educational Resources Information Center

    Penfield, Randall D.; Lee, Okhee

    2010-01-01

    Recent test-based accountability policy in the U.S. has involved annually assessing all students in core subjects and holding schools accountable for adequate progress of all students by implementing sanctions when adequate progress is not met. Despite its potential benefits, basing educational policy on assessments developed for a student…

  16. Impacts of Performance-Based Accountability on Institutional Performance in the U.S.

    ERIC Educational Resources Information Center

    Shin, Jung Cheol

    2010-01-01

    In the 1990s, most US states adopted new forms of performance-based accountability, e.g., performance-based budgeting, funding, or reporting. This study analyzed changes in institutional performance following the adoption of these new accountability standards. We measured institutional performance by representative education and research…

  17. Separation of time-based and trial-based accounts of the partial reinforcement extinction effect.

    PubMed

    Bouton, Mark E; Woods, Amanda M; Todd, Travis P

    2014-01-01

    Two appetitive conditioning experiments with rats examined time-based and trial-based accounts of the partial reinforcement extinction effect (PREE). In the PREE, the loss of responding that occurs in extinction is slower when the conditioned stimulus (CS) has been paired with a reinforcer on some of its presentations (partially reinforced) instead of every presentation (continuously reinforced). According to a time-based or "time-accumulation" view (e.g., Gallistel and Gibbon, 2000), the PREE occurs because the organism has learned in partial reinforcement to expect the reinforcer after a larger amount of time has accumulated in the CS over trials. In contrast, according to a trial-based view (e.g., Capaldi, 1967), the PREE occurs because the organism has learned in partial reinforcement to expect the reinforcer after a larger number of CS presentations. Experiment 1 used a procedure that equated partially and continuously reinforced groups on their expected times to reinforcement during conditioning. A PREE was still observed. Experiment 2 then used an extinction procedure that allowed time in the CS and the number of trials to accumulate differentially through extinction. The PREE was still evident when responding was examined as a function of expected time units to the reinforcer, but was eliminated when responding was examined as a function of expected trial units to the reinforcer. There was no evidence that the animal responded according to the ratio of time accumulated during the CS in extinction over the time in the CS expected before the reinforcer. The results thus favor a trial-based account over a time-based account of extinction and the PREE. This article is part of a Special Issue entitled: Associative and Temporal Learning.

  18. Cognitive fatigue: A Time-based Resource-sharing account.

    PubMed

    Borragán, Guillermo; Slama, Hichem; Bartolomei, Mario; Peigneux, Philippe

    2017-04-01

    Cognitive Fatigue (CF) is an important confound impacting cognitive performance. How CF is triggered and what are the features that make a cognitive effort perceived as exhausting remain unclear. In the theoretical framework of the Time-based Resource-sharing (TBRS) model (Barrouillet et al., 2004), we hypothesized that CF is an outcome of increased cognitive load due to constrained time to process ongoing cognitive demands. We tested this cognitive load-related CF hypothesis across 2 experiments manipulating both task complexity and cognitive load induced by the processing time interval. To do so, we used the TloadDback paradigm, a working memory dual task in which high and low cognitive load levels can be individually adjusted. In Experiment 1, participants were administered a high cognitive load (HCL, short processing time interval) and a low cognitive load (LCL, large processing time interval) conditions while complexity of the task was kept constant (1-back dual task). In Experiment 2, two tasks featuring different levels of complexity were both administered at the individual's maximal processing speed capacity for each task (i.e., short processing time interval). Results disclosed higher CF in the HCL than in the LCL condition in Experiment 1. On the contrary, in Experiment 2 similar levels of CF were obtained for different levels of task complexity when processing time interval was individually adjusted to induce a HCL condition. Altogether, our results indicate that processing time-related cognitive load eventually leads to the subjective feeling of CF, and to a decrease in alertness. In this framework, we propose that the development of CF can be envisioned as the result of sustained cognitive demands irrespective of task complexity.

  19. Sequential injection redox or acid-base titration for determination of ascorbic acid or acetic acid.

    PubMed

    Lenghor, Narong; Jakmunee, Jaroon; Vilen, Michael; Sara, Rolf; Christian, Gary D; Grudpan, Kate

    2002-12-06

    Two sequential injection titration systems with spectrophotometric detection have been developed. The first system for determination of ascorbic acid was based on redox reaction between ascorbic acid and permanganate in an acidic medium and lead to a decrease in color intensity of permanganate, monitored at 525 nm. A linear dependence of peak area obtained with ascorbic acid concentration up to 1200 mg l(-1) was achieved. The relative standard deviation for 11 replicate determinations of 400 mg l(-1) ascorbic acid was 2.9%. The second system, for acetic acid determination, was based on acid-base titration of acetic acid with sodium hydroxide using phenolphthalein as an indicator. The decrease in color intensity of the indicator was proportional to the acid content. A linear calibration graph in the range of 2-8% w v(-1) of acetic acid with a relative standard deviation of 4.8% (5.0% w v(-1) acetic acid, n=11) was obtained. Sample throughputs of 60 h(-1) were achieved for both systems. The systems were successfully applied for the assays of ascorbic acid in vitamin C tablets and acetic acid content in vinegars, respectively.

  20. Does Participation in a Computer-Based Learning Program in Introductory Financial Accounting Course Lead to Choosing Accounting as a Major?

    ERIC Educational Resources Information Center

    Owhoso, Vincent; Malgwi, Charles A.; Akpomi, Margaret

    2014-01-01

    The authors examine whether students who completed a computer-based intervention program, designed to help them develop abilities and skills in introductory accounting, later declared accounting as a major. A sample of 1,341 students participated in the study, of which 74 completed the intervention program (computer-based assisted learning [CBAL])…

  1. Acid and base degraded products of ketorolac.

    PubMed

    Salaris, Margherita; Nieddu, Maria; Rubattu, Nicola; Testa, Cecilia; Luongo, Elvira; Rimoli, Maria Grazia; Boatto, Gianpiero

    2010-06-05

    The stability of ketorolac tromethamine was investigated in acid (0.5M HCl) and alkaline conditions (0.5M NaOH), using the same procedure reported by Devarajan et al. [2]. The acid and base degradation products were identified by liquid chromatography-mass spectrometry (LC-MS).

  2. Community-Based School Finance and Accountability: A New Era for Local Control in Education Policy?

    ERIC Educational Resources Information Center

    Vasquez Heilig, Julian; Ward, Derrick R.; Weisman, Eric; Cole, Heather

    2014-01-01

    Top-down accountability policies have arguably had very limited impact over the past 20 years. Education stakeholders are now contemplating new forms of bottom-up accountability. In 2013, policymakers in California enacted a community-based approach that creates the Local Control Funding Formula (LCFF) process for school finance to increase…

  3. The Effect of Web-Based Collaborative Learning Methods to the Accounting Courses in Technical Education

    ERIC Educational Resources Information Center

    Cheng, K. W. Kevin

    2009-01-01

    This study mainly explored the effect of applying web-based collaborative learning instruction to the accounting curriculum on student's problem-solving attitudes in Technical Education. The research findings and proposed suggestions would serve as a reference for the development of accounting-related curricula and teaching strategies. To achieve…

  4. 24 CFR 990.280 - Project-based budgeting and accounting.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 24 Housing and Urban Development 4 2011-04-01 2011-04-01 false Project-based budgeting and... budgeting and accounting. (a) All PHAs covered by this subpart shall develop and maintain a system of budgeting and accounting for each project in a manner that allows for analysis of the actual revenues...

  5. Measure for Measure: How Proficiency-Based Accountability Systems Affect Inequality in Academic Achievement

    ERIC Educational Resources Information Center

    Jennings, Jennifer; Sohn, Heeju

    2014-01-01

    How do proficiency-based accountability systems affect inequality in academic achievement? This article reconciles mixed findings in the literature by demonstrating that three factors jointly determine accountability's impact. First, by analyzing student-level data from a large urban school district, we find that when educators face accountability…

  6. A network identity authentication protocol of bank account system based on fingerprint identification and mixed encryption

    NASA Astrophysics Data System (ADS)

    Zhu, Lijuan; Liu, Jingao

    2013-07-01

    This paper describes a network identity authentication protocol of bank account system based on fingerprint identification and mixed encryption. This protocol can provide every bank user a safe and effective way to manage his own bank account, and also can effectively prevent the hacker attacks and bank clerk crime, so that it is absolute to guarantee the legitimate rights and interests of bank users.

  7. 24 CFR 990.280 - Project-based budgeting and accounting.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... budgeting and accounting for each project in a manner that allows for analysis of the actual revenues and..., etc.). (b)(1) Financial information to be budgeted and accounted for at a project level shall include all data needed to complete project-based financial statements in accordance with...

  8. ASPEN--A Web-Based Application for Managing Student Server Accounts

    ERIC Educational Resources Information Center

    Sandvig, J. Christopher

    2004-01-01

    The growth of the Internet has greatly increased the demand for server-side programming courses at colleges and universities. Students enrolled in such courses must be provided with server-based accounts that support the technologies that they are learning. The process of creating, managing and removing large numbers of student server accounts is…

  9. A Review of Financial Accounting Fraud Detection based on Data Mining Techniques

    NASA Astrophysics Data System (ADS)

    Sharma, Anuj; Kumar Panigrahi, Prabin

    2012-02-01

    With an upsurge in financial accounting fraud in the current economic scenario experienced, financial accounting fraud detection (FAFD) has become an emerging topic of great importance for academic, research and industries. The failure of internal auditing system of the organization in identifying the accounting frauds has lead to use of specialized procedures to detect financial accounting fraud, collective known as forensic accounting. Data mining techniques are providing great aid in financial accounting fraud detection, since dealing with the large data volumes and complexities of financial data are big challenges for forensic accounting. This paper presents a comprehensive review of the literature on the application of data mining techniques for the detection of financial accounting fraud and proposes a framework for data mining techniques based accounting fraud detection. The systematic and comprehensive literature review of the data mining techniques applicable to financial accounting fraud detection may provide a foundation to future research in this field. The findings of this review show that data mining techniques like logistic models, neural networks, Bayesian belief network, and decision trees have been applied most extensively to provide primary solutions to the problems inherent in the detection and classification of fraudulent data.

  10. Solid Acid Based Fuel Cells

    DTIC Science & Technology

    2007-11-02

    superprotonic solid acids with elements such as P, As, Si and Ge, which have greater affinities to oxygen , we anticipate that the reduction reaction will be...bulk material consisted of an apatite phase (hexagonal symmetry) of variable composition, LixLa10-x(SiO4)6O3-x, with excess lithium residing in the...in Tables 1 and 2, indicate that this compound is a rather conventional apatite with fixed stoichiometry, LiLa9(SiO4)6O2 (x = 1). Such a result is

  11. Synthesis of new kojic acid based unnatural α-amino acid derivatives.

    PubMed

    Balakrishna, C; Payili, Nagaraju; Yennam, Satyanarayana; Devi, P Uma; Behera, Manoranjan

    2015-11-01

    An efficient method for the preparation of kojic acid based α-amino acid derivatives by alkylation of glycinate schiff base with bromokojic acids have been described. Using this method, mono as well as di alkylated kojic acid-amino acid conjugates have been prepared. This is the first synthesis of C-linked kojic acid-amino acid conjugate where kojic acid is directly linked to amino acid through a C-C bond.

  12. Combating QR-Code-Based Compromised Accounts in Mobile Social Networks

    PubMed Central

    Guo, Dong; Cao, Jian; Wang, Xiaoqi; Fu, Qiang; Li, Qiang

    2016-01-01

    Cyber Physical Social Sensing makes mobile social networks (MSNs) popular with users. However, such attacks are rampant as malicious URLs are spread covertly through quick response (QR) codes to control compromised accounts in MSNs to propagate malicious messages. Currently, there are generally two types of methods to identify compromised accounts in MSNs: one type is to analyze the potential threats on wireless access points and the potential threats on handheld devices’ operation systems so as to stop compromised accounts from spreading malicious messages; the other type is to apply the method of detecting compromised accounts in online social networks to MSNs. The above types of methods above focus neither on the problems of MSNs themselves nor on the interaction of sensors’ messages, which leads to the restrictiveness of platforms and the simplification of methods. In order to stop the spreading of compromised accounts in MSNs effectively, the attacks have to be traced to their sources first. Through sensors, users exchange information in MSNs and acquire information by scanning QR codes. Therefore, analyzing the traces of sensor-related information helps to identify the compromised accounts in MSNs. This paper analyzes the diversity of information sending modes of compromised accounts and normal accounts, analyzes the regularity of GPS (Global Positioning System)-based location information, and introduces the concepts of entropy and conditional entropy so as to construct an entropy-based model based on machine learning strategies. To achieve the goal, about 500,000 accounts of Sina Weibo and about 100 million corresponding messages are collected. Through the validation, the accuracy rate of the model is proved to be as high as 87.6%, and the false positive rate is only 3.7%. Meanwhile, the comparative experiments of the feature sets prove that sensor-based location information can be applied to detect the compromised accounts in MSNs. PMID:27657071

  13. Combating QR-Code-Based Compromised Accounts in Mobile Social Networks.

    PubMed

    Guo, Dong; Cao, Jian; Wang, Xiaoqi; Fu, Qiang; Li, Qiang

    2016-09-20

    Cyber Physical Social Sensing makes mobile social networks (MSNs) popular with users. However, such attacks are rampant as malicious URLs are spread covertly through quick response (QR) codes to control compromised accounts in MSNs to propagate malicious messages. Currently, there are generally two types of methods to identify compromised accounts in MSNs: one type is to analyze the potential threats on wireless access points and the potential threats on handheld devices' operation systems so as to stop compromised accounts from spreading malicious messages; the other type is to apply the method of detecting compromised accounts in online social networks to MSNs. The above types of methods above focus neither on the problems of MSNs themselves nor on the interaction of sensors' messages, which leads to the restrictiveness of platforms and the simplification of methods. In order to stop the spreading of compromised accounts in MSNs effectively, the attacks have to be traced to their sources first. Through sensors, users exchange information in MSNs and acquire information by scanning QR codes. Therefore, analyzing the traces of sensor-related information helps to identify the compromised accounts in MSNs. This paper analyzes the diversity of information sending modes of compromised accounts and normal accounts, analyzes the regularity of GPS (Global Positioning System)-based location information, and introduces the concepts of entropy and conditional entropy so as to construct an entropy-based model based on machine learning strategies. To achieve the goal, about 500,000 accounts of Sina Weibo and about 100 million corresponding messages are collected. Through the validation, the accuracy rate of the model is proved to be as high as 87.6%, and the false positive rate is only 3.7%. Meanwhile, the comparative experiments of the feature sets prove that sensor-based location information can be applied to detect the compromised accounts in MSNs.

  14. Accounting for pairwise distance restraints in FFT-based protein-protein docking.

    PubMed

    Xia, Bing; Vajda, Sandor; Kozakov, Dima

    2016-11-01

    ClusPro is a heavily used protein-protein docking server based on the fast Fourier transform (FFT) correlation approach. While FFT enables global docking, accounting for pairwise distance restraints using penalty terms in the scoring function is computationally expensive. We use a different approach and directly select low energy solutions that also satisfy the given restraints. As expected, accounting for restraints generally improves the rank of near native predictions, while retaining or even improving the numerical efficiency of FFT based docking.

  15. A Direct, Biomass-Based Synthesis of Benzoic Acid: Formic Acid-Mediated Deoxygenation of the Glucose-Derived Materials Quinic Acid and Shikimic Acid

    SciTech Connect

    Arceo, Elena; Ellman, Jonathan; Bergman, Robert

    2010-05-03

    An alternative biomass-based route to benzoic acid from the renewable starting materials quinic acid and shikimic acid is described. Benzoic acid is obtained selectively using a highly efficient, one-step formic acid-mediated deoxygenation method.

  16. Analyzing the Operation of Performance-Based Accountability Systems for Public Services. Technical Report

    ERIC Educational Resources Information Center

    Camm, Frank; Stecher, Brian M.

    2010-01-01

    Empirical evidence of the effects of performance-based public management is scarce. This report describes a framework used to organize available empirical information on one form of performance-based management, a performance-based accountability system (PBAS). Such a system identifies individuals or organizations that must change their behavior…

  17. Financial Management Reforms in the Health Sector: A Comparative Study Between Cash-based and Accrual-based Accounting Systems

    PubMed Central

    Abolhallaje, Masoud; Jafari, Mehdi; Seyedin, Hesam; Salehi, Masoud

    2014-01-01

    Background: Financial management and accounting reform in the public sectors was started in 2000. Moving from cash-based to accrual-based is considered as the key component of these reforms and adjustments in the public sector. Performing this reform in the health system is a part of a bigger reform under the new public management. Objectives: The current study aimed to analyze the movement from cash-based to accrual-based accounting in the health sector in Iran. Patients and Methods: This comparative study was conducted in 2013 to compare financial management and movement from cash-based to accrual-based accounting in health sector in the countries such as the United States, Britain, Canada, Australia, New Zealand, and Iran. Library resources and reputable databases such as Medline, Elsevier, Index Copernicus, DOAJ, EBSCO-CINAHL and SID, and Iranmedex were searched. Fish cards were used to collect the data. Data were compared and analyzed using comparative tables. Results: Developed countries have implemented accrual-based accounting and utilized the valid, reliable and practical information in accrual-based reporting in different areas such as price and tariffs setting, operational budgeting, public accounting, performance evaluation and comparison and evidence based decision making. In Iran, however, only a few public organizations such as the municipalities and the universities of medical sciences use accrual-based accounting, but despite what is required by law, the other public organizations do not use accrual-based accounting. Conclusions: There are advantages in applying accrual-based accounting in the public sector which certainly depends on how this system is implemented in the sector. PMID:25763194

  18. 24 CFR 990.280 - Project-based budgeting and accounting.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... URBAN DEVELOPMENT THE PUBLIC HOUSING OPERATING FUND PROGRAM Asset Management § 990.280 Project-based... asset management fee may be charged only if the PHA performs all asset management activities described in this subpart (including project-based management, budgeting, and accounting). Asset...

  19. Beyond Traditional Literacy Instruction: Toward an Account-Based Literacy Training Curriculum in Libraries

    ERIC Educational Resources Information Center

    Cirella, David

    2012-01-01

    A diverse group, account-based services include a wide variety of sites commonly used by patrons, including online shopping sites, social networks, photo- and video-sharing sites, banking and financial sites, government services, and cloud-based storage. Whether or not a piece of information is obtainable online must be considered when creating…

  20. Jigsaw Cooperative Learning: Acid-Base Theories

    ERIC Educational Resources Information Center

    Tarhan, Leman; Sesen, Burcin Acar

    2012-01-01

    This study focused on investigating the effectiveness of jigsaw cooperative learning instruction on first-year undergraduates' understanding of acid-base theories. Undergraduates' opinions about jigsaw cooperative learning instruction were also investigated. The participants of this study were 38 first-year undergraduates in chemistry education…

  1. Separation of Acids, Bases, and Neutral Compounds

    NASA Astrophysics Data System (ADS)

    Fujita, Megumi; Mah, Helen M.; Sgarbi, Paulo W. M.; Lall, Manjinder S.; Ly, Tai Wei; Browne, Lois M.

    2003-01-01

    Separation of Acids, Bases, and Neutral Compounds requires the following software, which is available for free download from the Internet: Netscape Navigator, version 4.75 or higher, or Microsoft Internet Explorer, version 5.0 or higher; Chime plug-in, version compatible with your OS and browser (available from MDL); and Flash player, version 5 or higher (available from Macromedia).

  2. Linear Titration Curves of Acids and Bases.

    PubMed

    Joseph, N R

    1959-05-29

    The Henderson-Hasselbalch equation, by a simple transformation, becomes pH - pK = pA - pB, where pA and pB are the negative logarithms of acid and base concentrations. Sigmoid titration curves then reduce to straight lines; titration curves of polyelectrolytes, to families of straight lines. The method is applied to the titration of the dipeptide glycyl aminotricarballylic acid, with four titrable groups. Results are expressed as Cartesian and d'Ocagne nomograms. The latter is of a general form applicable to polyelectrolytes of any degree of complexity.

  3. Failing Tests: Commentary on "Adapting Educational Measurement to the Demands of Test-Based Accountability"

    ERIC Educational Resources Information Center

    Thissen, David

    2015-01-01

    In "Adapting Educational Measurement to the Demands of Test-Based Accountability" Koretz takes the time-honored engineering approach to educational measurement, identifying specific problems with current practice and proposing minimal modifications of the system to alleviate those problems. In response to that article, David Thissen…

  4. A Road to Results: Results-Based Accountability in the Annie E. Casey Foundation's Education Program

    ERIC Educational Resources Information Center

    Manno, Bruno V.

    2006-01-01

    This report details the Annie E. Casey Foundation's four-year effort to develop a "results-based accountability" (RBA) approach to its K-12 education portfolio. Though still a work in progress, the Foundation's experience with RBA can help other philanthropic organizations and individual donors develop their own approaches to producing and…

  5. Historicizing and Contextualizing Global Policy Discourses: Test- and Standards-Based Accountabilities in Education

    ERIC Educational Resources Information Center

    Lingard, Bob

    2013-01-01

    This paper in commenting on the contributions to this special number demonstrates the necessity of historicizing and contextualizing the rise of test- and standards-based modes of accountability in contemporary education policy globally. Both are imperative for understanding specific national manifestations of what has become a globalized…

  6. Is Comprehension Necessary for Error Detection? A Conflict-Based Account of Monitoring in Speech Production

    ERIC Educational Resources Information Center

    Nozari, Nazbanou; Dell, Gary S.; Schwartz, Myrna F.

    2011-01-01

    Despite the existence of speech errors, verbal communication is successful because speakers can detect (and correct) their errors. The standard theory of speech-error detection, the perceptual-loop account, posits that the comprehension system monitors production output for errors. Such a comprehension-based monitor, however, cannot explain the…

  7. Toward an Episodic Context Account of Retrieval-Based Learning: Dissociating Retrieval Practice and Elaboration

    ERIC Educational Resources Information Center

    Lehman, Melissa; Smith, Megan A.; Karpicke, Jeffrey D.

    2014-01-01

    We tested the predictions of 2 explanations for retrieval-based learning; while the elaborative retrieval hypothesis assumes that the retrieval of studied information promotes the generation of semantically related information, which aids in later retrieval (Carpenter, 2009), the episodic context account proposed by Karpicke, Lehman, and Aue (in…

  8. The Influence of Performance-Based Accountability on the Distribution of Teacher Salary Increases

    ERIC Educational Resources Information Center

    Bifulco, Robert

    2010-01-01

    This study examines how aspects of a district's institutional and policy environment influence the distribution of teacher salary increases. The primary hypothesis tested is that statewide performance-based accountability policies influence the extent to which districts backload teacher salary increases. I use data on teacher salaries from the…

  9. Reality-Based Learning and Interdisciplinary Teams: An Interactive Approach Integrating Accounting and Engineering Technology.

    ERIC Educational Resources Information Center

    Rogers, Robert L.; Stemkoski, Michael J.

    This paper describes a reality-based learning project in which sophomore accounting and engineering students collaborated in interdisciplinary teams to design and build a million-dollar waterslide park. Two weeks into the project, the teams received a briefing from an industrial panel of engineers, bankers, entrepreneurs, and other professionals.…

  10. Outcome-Based Education and Student Learning in Managerial Accounting in Hong Kong

    ERIC Educational Resources Information Center

    Lui, Gladie; Shum, Connie

    2012-01-01

    Although Outcome-based Education has not been successful in public education in several countries, it has been successful in the medical fields in higher education in the U.S. The author implemented OBE in her Managerial Accounting course in H.K. Intended learning outcomes were mapped again Bloom's Cognitive Domain. Teaching and learning…

  11. Dynamic model of production enterprises based on accounting registers and its identification

    NASA Astrophysics Data System (ADS)

    Sirazetdinov, R. T.; Samodurov, A. V.; Yenikeev, I. A.; Markov, D. S.

    2016-06-01

    The report focuses on the mathematical modeling of economic entities based on accounting registers. Developed the dynamic model of financial and economic activity of the enterprise as a system of differential equations. Created algorithms for identification of parameters of the dynamic model. Constructed and identified the model of Russian machine-building enterprises.

  12. Preferences for Team Learning and Lecture-Based Learning among First-Year Undergraduate Accounting Students

    ERIC Educational Resources Information Center

    Opdecam, Evelien; Everaert, Patricia; Van Keer, Hilde; Buysschaert, Fanny

    2014-01-01

    This study investigates students' "preference" for team learning and its effectiveness, compared to lecture-based learning. A quasi-experiment was set up in a financial accounting course in the first-year undergraduate of the Economics and Business Administration Program, where students had to choose between one of the two learning…

  13. The Social Organization of School Counseling in the Era of Standards-Based Accountability

    ERIC Educational Resources Information Center

    Dorsey, Alexander C.

    2011-01-01

    The reform policies of standards-based accountability, as outlined in NCLB, impede the functioning of school counseling programs and the delivery of services to students. Although recent studies have focused on the transformation of the school counseling profession, a gap exists in the literature with regard to how the experiences of school…

  14. Toward a Culture of Consequences: Performance-Based Accountability Systems for Public Services. Monograph

    ERIC Educational Resources Information Center

    Stecher, Brian M.; Camm, Frank; Damberg, Cheryl L.; Hamilton, Laura S.; Mullen, Kathleen J.; Nelson, Christopher; Sorensen, Paul; Wachs, Martin; Yoh, Allison; Zellman, Gail L.

    2010-01-01

    Performance-based accountability systems (PBASs), which link incentives to measured performance as a means of improving services to the public, have gained popularity. While PBASs can vary widely across sectors, they share three main components: goals, incentives, and measures. Research suggests that PBASs influence provider behaviors, but little…

  15. The first proton sponge-based amino acids: synthesis, acid-base properties and some reactivity.

    PubMed

    Ozeryanskii, Valery A; Gorbacheva, Anastasia Yu; Pozharskii, Alexander F; Vlasenko, Marina P; Tereznikov, Alexander Yu; Chernov'yants, Margarita S

    2015-08-21

    The first hybrid base constructed from 1,8-bis(dimethylamino)naphthalene (proton sponge or DMAN) and glycine, N-methyl-N-(8-dimethylamino-1-naphthyl)aminoacetic acid, was synthesised in high yield and its hydrobromide was structurally characterised and used to determine the acid-base properties via potentiometric titration. It was found that the basic strength of the DMAN-glycine base (pKa = 11.57, H2O) is on the level of amidine amino acids like arginine and creatine and its structure, zwitterionic vs. neutral, based on the spectroscopic (IR, NMR, mass) and theoretical (DFT) approaches has a strong preference to the zwitterionic form. Unlike glycine, the DMAN-glycine zwitterion is N-chiral and is hydrolytically cleaved with the loss of glycolic acid on heating in DMSO. This reaction together with the mild decarboxylative conversion of proton sponge-based amino acids into 2,3-dihydroperimidinium salts under air-oxygen was monitored with the help of the DMAN-alanine amino acid. The newly devised amino acids are unique as they combine fluorescence, strongly basic and redox-active properties.

  16. A simulation model of hospital management based on cost accounting analysis according to disease.

    PubMed

    Tanaka, Koji; Sato, Junzo; Guo, Jinqiu; Takada, Akira; Yoshihara, Hiroyuki

    2004-12-01

    Since a little before 2000, hospital cost accounting has been increasingly performed at Japanese national university hospitals. At Kumamoto University Hospital, for instance, departmental costs have been analyzed since 2000. And, since 2003, the cost balance has been obtained according to certain diseases for the preparation of Diagnosis-Related Groups and Prospective Payment System. On the basis of these experiences, we have constructed a simulation model of hospital management. This program has worked correctly at repeated trials and with satisfactory speed. Although there has been room for improvement of detailed accounts and cost accounting engine, the basic model has proved satisfactory. We have constructed a hospital management model based on the financial data of an existing hospital. We will later improve this program from the viewpoint of construction and using more various data of hospital management. A prospective outlook may be obtained for the practical application of this hospital management model.

  17. Measure for Measure: How Proficiency-Based Accountability Systems Affect Inequality in Academic Achievement

    PubMed Central

    Jennings, Jennifer; Sohn, Heeju

    2016-01-01

    How do proficiency-based accountability systems affect inequality in academic achievement? This paper reconciles mixed findings in the literature by demonstrating that three factors jointly determine accountability's impact. First, by analyzing student-level data from a large urban school district, we find that when educators face accountability pressure, they focus attention on students closest to proficiency. We refer to this practice as educational triage, and show that the difficulty of the proficiency standard affects whether lower or higher performing students gain most on high-stakes tests used to evaluate schools. Less difficult proficiency standards decrease inequality in high-stakes achievement, while more difficult ones increase it. Second, we show that educators emphasize test-specific skills with students near proficiency, a practice that we refer to as instructional triage. As a result, the effects of accountability pressure differ across high and low-stakes tests; we find no effects on inequality in low-stakes reading and math tests of similar skills. Finally, we provide suggestive evidence that instructional triage is most pronounced in the lowest performing schools. We conclude by discussing how these findings shape our understanding of accountability's impacts on educational inequality. PMID:27122642

  18. Measure for Measure: How Proficiency-Based Accountability Systems Affect Inequality in Academic Achievement.

    PubMed

    Jennings, Jennifer; Sohn, Heeju

    2014-04-01

    How do proficiency-based accountability systems affect inequality in academic achievement? This paper reconciles mixed findings in the literature by demonstrating that three factors jointly determine accountability's impact. First, by analyzing student-level data from a large urban school district, we find that when educators face accountability pressure, they focus attention on students closest to proficiency. We refer to this practice as educational triage, and show that the difficulty of the proficiency standard affects whether lower or higher performing students gain most on high-stakes tests used to evaluate schools. Less difficult proficiency standards decrease inequality in high-stakes achievement, while more difficult ones increase it. Second, we show that educators emphasize test-specific skills with students near proficiency, a practice that we refer to as instructional triage. As a result, the effects of accountability pressure differ across high and low-stakes tests; we find no effects on inequality in low-stakes reading and math tests of similar skills. Finally, we provide suggestive evidence that instructional triage is most pronounced in the lowest performing schools. We conclude by discussing how these findings shape our understanding of accountability's impacts on educational inequality.

  19. The acid-base titration of montmorillonite

    NASA Astrophysics Data System (ADS)

    Bourg, I. C.; Sposito, G.; Bourg, A. C.

    2003-12-01

    Proton binding to clay minerals plays an important role in the chemical reactivity of soils (e.g., acidification, retention of nutrients or pollutants). If should also affect the performance of clay barriers for waste disposal. The surface acidity of clay minerals is commonly modelled empirically by assuming generic amphoteric surface sites (>SOH) on a flat surface, with fitted site densities and acidity constant. Current advances in experimental methods (notably spectroscopy) are rapidly improving our understanding of the structure and reactivity of the surface of clay minerals (arrangement of the particles, nature of the reactive surface sites, adsorption mechanisms). These developments are motivated by the difficulty of modelling the surface chemistry of mineral surfaces at the macro-scale (e.g., adsorption or titration) without a detailed (molecular-scale) picture of the mechanisms, and should be progressively incorporated into surface complexation models. In this view, we have combined recent estimates of montmorillonite surface properties (surface site density and structure, edge surface area, surface electrostatic potential) with surface site acidities obtained from the titration of alpha-Al2O3 and SiO2, and a novel method of accounting for the unknown initial net proton surface charge of the solid. The model predictions were compared to experimental titrations of SWy-1 montmorillonite and purified MX-80 bentonite in 0.1-0.5 mol/L NaClO4 and 0.005-0.5 mol/L NaNO3 background electrolytes, respectively. Most of the experimental data were appropriately described by the model after we adjusted a single parameter (silanol sites on the surface of montmorillonite were made to be slightly more acidic than those of silica). At low ionic strength and acidic pH the model underestimated the buffering capacity of the montmorillonite, perhaps due to clay swelling or to the interlayer adsorption of dissolved aluminum. The agreement between our model and the experimental

  20. Standards-Based Accountability as a Tool for Making a Difference in Student Learning. A State and an Institutional Perspective on Standards-Based Accountability.

    ERIC Educational Resources Information Center

    Wilkerson, Judy R.

    This paper examines Florida's standards-driven performance assessment, emphasizing teacher preparation, and touching on K-12 accountability. Florida's educational reform and accountability efforts are driven by the Florida System of School Improvement and Accountability document. The system is derived from state goals similar to the national Goals…

  1. Investigating Students' Reasoning about Acid-Base Reactions

    ERIC Educational Resources Information Center

    Cooper, Melanie M.; Kouyoumdjian, Hovig; Underwood, Sonia M.

    2016-01-01

    Acid-base chemistry is central to a wide range of reactions. If students are able to understand how and why acid-base reactions occur, it should provide a basis for reasoning about a host of other reactions. Here, we report the development of a method to characterize student reasoning about acid-base reactions based on their description of…

  2. Accounting Technology Associate Degree. Louisiana Technical Education Program and Course Standards. Competency-Based Postsecondary Curriculum Outline from Bulletin 1822.

    ERIC Educational Resources Information Center

    Louisiana State Dept. of Education, Baton Rouge. Div. of Vocational Education.

    This document outlines the curriculum of Louisiana's accounting technology associate degree program, which is a 6-term (77-credit hour) competency-based program designed to prepare students for employment as accounting technicians providing technical administrative support to professional accountants and other financial management personnel.…

  3. High Performance Controllers Based on Real Parameters to Account for Parameter Variations due to Iron Saturation

    DTIC Science & Technology

    2013-08-01

    Article 3. DATES COVERED 10-04-2013 to 15-07-2013 4 . TITLE AND SUBTITLE HIGH PERFORMANCE CONTROLLERS BASED ON REALPARAMETERS TO ACCOUNT FOR... 4 )   3 4 d q q d P T i i   (5...ideal model (3) and ( 4 ). Instead, the flux linkages become coupled to both axis currents, this coupling effect can be modeled as follows

  4. The physiological assessment of acid-base balance.

    PubMed

    Howorth, P J

    1975-04-01

    Acid-base terminology including the sue of SI units is reviewed. The historical reasons why nomograms have been particularly used in acid-base work are discussed. The theoretical basis of the Henderson-Hasselbalch equation is considered. It is emphasized that the solubility of CO2 in plasma and the apparent first dissociation constant of carbonic acid are not chemical constants when applied to media of uncertain and varying composition such as blood plasma. The use of the Henderson-Hasselbalch equation in making hypothermia corrections for PCO2 is discussed. The Astrup system for the in vitro determination of blood gases and derived parameters is described and the theoretical weakness of the base excess concept stressed. A more clinically-oriented approach to the assessment of acid-base problems is presented. Measurement of blood [H+] and PCO2 are considered to be primary data which should be recorded on a chart with in vivo CO2-titration lines (see below). Clinical information and results of other laboratory investigations such as plasma bicarbonate, PO2,P50 are then to be considered together with the primary data. In order to interpret this combined information it is essential to take into account the known ventilatory response to metabolic acidosis and alkalosis, and the renal response to respiratory acidosis and alkalosis. The use is recommended of a chart showing the whole-body CO2-titration points obtained when patients with different initial levels of non-respiratory [H+] are ventilated. A number of examples are given of the use of this [H+] and PCO2 in vivo chart in the interpretation of acid-base data. The aetiology, prognosis and treatment of metabolic alkalosis is briefly reviewed. Treatment with intravenous acid is recommended for established cases. Attention is drawn to the possibility of iatrogenic production of metabolic alkalosis. Caution is expressed over the use of intravenous alkali in all but the severest cases of metabolic acidosis. The role of

  5. The Symbol Grounding Problem Revisited: A Thorough Evaluation of the ANS Mapping Account and the Proposal of an Alternative Account Based on Symbol–Symbol Associations

    PubMed Central

    Reynvoet, Bert; Sasanguie, Delphine

    2016-01-01

    Recently, a lot of studies in the domain of numerical cognition have been published demonstrating a robust association between numerical symbol processing and individual differences in mathematics achievement. Because numerical symbols are so important for mathematics achievement, many researchers want to provide an answer on the ‘symbol grounding problem,’ i.e., how does a symbol acquires its numerical meaning? The most popular account, the approximate number system (ANS) mapping account, assumes that a symbol acquires its numerical meaning by being mapped on a non-verbal and ANS. Here, we critically evaluate four arguments that are supposed to support this account, i.e., (1) there is an evolutionary system for approximate number processing, (2) non-symbolic and symbolic number processing show the same behavioral effects, (3) non-symbolic and symbolic numbers activate the same brain regions which are also involved in more advanced calculation and (4) non-symbolic comparison is related to the performance on symbolic mathematics achievement tasks. Based on this evaluation, we conclude that all of these arguments and consequently also the mapping account are questionable. Next we explored less popular alternative, where small numerical symbols are initially mapped on a precise representation and then, in combination with increasing knowledge of the counting list result in an independent and exact symbolic system based on order relations between symbols. We evaluate this account by reviewing evidence on order judgment tasks following the same four arguments. Although further research is necessary, the available evidence so far suggests that this symbol–symbol association account should be considered as a worthy alternative of how symbols acquire their meaning. PMID:27790179

  6. An Introductory Laboratory Exercise for Acids and Bases.

    ERIC Educational Resources Information Center

    Miller, Richard; Silberman, Robert

    1986-01-01

    Discusses an acid-base neutralization exercise requiring groups of students to determine: (1) combinations of solutions giving neutralization; (2) grouping solutions as acids or bases; and (3) ranking groups in order of concentration. (JM)

  7. The Bronsted-Lowery Acid-Base Concept.

    ERIC Educational Resources Information Center

    Kauffman, George B.

    1988-01-01

    Gives the background history of the simultaneous discovery of acid-base relationships by Johannes Bronsted and Thomas Lowry. Provides a brief biographical sketch of each. Discusses their concept of acids and bases in some detail. (CW)

  8. Coronavirus phylogeny based on triplets of nucleic acids bases

    NASA Astrophysics Data System (ADS)

    Liao, Bo; Liu, Yanshu; Li, Renfa; Zhu, Wen

    2006-04-01

    We considered the fully overlapping triplets of nucleotide bases and proposed a 2D graphical representation of protein sequences consisting of 20 amino acids and a stop code. Based on this 2D graphical representation, we outlined a new approach to analyze the phylogenetic relationships of coronaviruses by constructing a covariance matrix. The evolutionary distances are obtained through measuring the differences among the two-dimensional curves.

  9. Mathematical modeling of acid-base physiology

    PubMed Central

    Occhipinti, Rossana; Boron, Walter F.

    2015-01-01

    pH is one of the most important parameters in life, influencing virtually every biological process at the cellular, tissue, and whole-body level. Thus, for cells, it is critical to regulate intracellular pH (pHi) and, for multicellular organisms, to regulate extracellular pH (pHo). pHi regulation depends on the opposing actions of plasma-membrane transporters that tend to increase pHi, and others that tend to decrease pHi. In addition, passive fluxes of uncharged species (e.g., CO2, NH3) and charged species (e.g., HCO3− , NH4+) perturb pHi. These movements not only influence one another, but also perturb the equilibria of a multitude of intracellular and extracellular buffers. Thus, even at the level of a single cell, perturbations in acid-base reactions, diffusion, and transport are so complex that it is impossible to understand them without a quantitative model. Here we summarize some mathematical models developed to shed light onto the complex interconnected events triggered by acids-base movements. We then describe a mathematical model of a spherical cell–which to our knowledge is the first one capable of handling a multitude of buffer reaction–that our team has recently developed to simulate changes in pHi and pHo caused by movements of acid-base equivalents across the plasma membrane of a Xenopus oocyte. Finally, we extend our work to a consideration of the effects of simultaneous CO2 and HCO3− influx into a cell, and envision how future models might extend to other cell types (e.g., erythrocytes) or tissues (e.g., renal proximal-tubule epithelium) important for whole-body pH homeostasis. PMID:25617697

  10. Bipolar Membranes for Acid Base Flow Batteries

    NASA Astrophysics Data System (ADS)

    Anthamatten, Mitchell; Roddecha, Supacharee; Jorne, Jacob; Coughlan, Anna

    2011-03-01

    Rechargeable batteries can provide grid-scale electricity storage to match power generation with consumption and promote renewable energy sources. Flow batteries offer modular and flexible design, low cost per kWh and high efficiencies. A novel flow battery concept will be presented based on acid-base neutralization where protons (H+) and hydroxyl (OH-) ions react electrochemically to produce water. The large free energy of this highly reversible reaction can be stored chemically, and, upon discharge, can be harvested as usable electricity. The acid-base flow battery concept avoids the use of a sluggish oxygen electrode and utilizes the highly reversible hydrogen electrode, thus eliminating the need for expensive noble metal catalysts. The proposed flow battery is a hybrid of a battery and a fuel cell---hydrogen gas storing chemical energy is produced at one electrode and is immediately consumed at the other electrode. The two electrodes are exposed to low and high pH solutions, and these solutions are separated by a hybrid membrane containing a hybrid cation and anion exchange membrane (CEM/AEM). Membrane design will be discussed, along with ion-transport data for synthesized membranes.

  11. Photocurable bioadhesive based on lactic acid.

    PubMed

    Marques, D S; Santos, J M C; Ferreira, P; Correia, T R; Correia, I J; Gil, M H; Baptista, C M S G

    2016-01-01

    Novel photocurable and low molecular weight oligomers based on l-lactic acid with proven interest to be used as bioadhesive were successfully manufactured. Preparation of lactic acid oligomers with methacrylic end functionalizations was carried out in the absence of catalyst or solvents by self-esterification in two reaction steps: telechelic lactic acid oligomerization with OH end groups and further functionalization with methacrylic anhydride. The final adhesive composition was achieved by the addition of a reported biocompatible photoinitiator (Irgacure® 2959). Preliminary in vitro biodegradability was investigated by hydrolytic degradation in PBS (pH=7.4) at 37 °C. The adhesion performance was evaluated using glued aminated substrates (gelatine pieces) subjected to pull-to-break test. Surface energy measured by contact angles is lower than the reported values of the skin and blood. The absence of cytoxicity was evaluated using human fibroblasts. A notable antimicrobial behaviour was observed using two bacterial models (Staphylococcus aureus and Escherichia coli). The cured material exhibited a strong thrombogenic character when placed in contact with blood, which can be predicted as a haemostatic effect for bleeding control. This novel material was subjected to an extensive characterization showing great potential for bioadhesive or other biomedical applications where biodegradable and biocompatible photocurable materials are required.

  12. Reexamining the language account of cross-national differences in base-10 number representations.

    PubMed

    Vasilyeva, Marina; Laski, Elida V; Ermakova, Anna; Lai, Weng-Feng; Jeong, Yoonkyung; Hachigian, Amy

    2015-01-01

    East Asian students consistently outperform students from other nations in mathematics. One explanation for this advantage is a language account; East Asian languages, unlike most Western languages, provide cues about the base-10 structure of multi-digit numbers, facilitating the development of base-10 number representations. To test this view, the current study examined how kindergartners represented two-digit numbers using single unit-blocks and ten-blocks. The participants (N=272) were from four language groups (Korean, Mandarin, English, and Russian) that vary in the extent of "transparency" of the base-10 structure. In contrast to previous findings with older children, kindergartners showed no cross-language variability in the frequency of producing base-10 representations. Furthermore, they showed a pattern of within-language variability that was not consistent with the language account and was likely attributable to experiential factors. These findings suggest that language might not play as critical a role in the development of base-10 representations as suggested in earlier research.

  13. A behavior-analytic account of depression and a case report using acceptance-based procedures

    PubMed Central

    Dougher, Michael J.; Hackbert, Lucianne

    1994-01-01

    Although roughly 6% of the general population is affected by depression at some time during their lifetime, the disorder has been relatively neglected by behavior analysts. The preponderance of research on the etiology and treatment of depression has been conducted by cognitive behavior theorists and biological psychiatrists and psychopharmacologists interested in the biological substrates of depression. These approaches have certainly been useful, but their reliance on cognitive and biological processes and their lack of attention to environment—behavior relations render them unsatisfactory from a behavior-analytic perspective. The purpose of this paper is to provide a behavior-analytic account of depression and to derive from this account several possible treatment interventions. In addition, case material is presented to illustrate an acceptance-based approach with a depressed client. PMID:22478195

  14. Teaching Acid/Base Physiology in the Laboratory

    ERIC Educational Resources Information Center

    Friis, Ulla G.; Plovsing, Ronni; Hansen, Klaus; Laursen, Bent G.; Wallstedt, Birgitta

    2010-01-01

    Acid/base homeostasis is one of the most difficult subdisciplines of physiology for medical students to master. A different approach, where theory and practice are linked, might help students develop a deeper understanding of acid/base homeostasis. We therefore set out to develop a laboratory exercise in acid/base physiology that would provide…

  15. A clinical approach to acid-base conundrums.

    PubMed

    Garrubba, Carl; Truscott, Judy

    2016-04-01

    Acid-base disorders can provide essential clues to underlying patient conditions. This article provides a simple, practical approach to identifying simple acid-base disorders and their compensatory mechanisms. Using this stepwise approach, clinicians can quickly identify and appropriately treat acid-base disorders.

  16. Using Willie's Acid-Base Box for Blood Gas Analysis

    ERIC Educational Resources Information Center

    Dietz, John R.

    2011-01-01

    In this article, the author describes a method developed by Dr. William T. Lipscomb for teaching blood gas analysis of acid-base status and provides three examples using Willie's acid-base box. Willie's acid-base box is constructed using three of the parameters of standard arterial blood gas analysis: (1) pH; (2) bicarbonate; and (3) CO[subscript…

  17. Salience and Attention in Surprisal-Based Accounts of Language Processing

    PubMed Central

    Zarcone, Alessandra; van Schijndel, Marten; Vogels, Jorrig; Demberg, Vera

    2016-01-01

    The notion of salience has been singled out as the explanatory factor for a diverse range of linguistic phenomena. In particular, perceptual salience (e.g., visual salience of objects in the world, acoustic prominence of linguistic sounds) and semantic-pragmatic salience (e.g., prominence of recently mentioned or topical referents) have been shown to influence language comprehension and production. A different line of research has sought to account for behavioral correlates of cognitive load during comprehension as well as for certain patterns in language usage using information-theoretic notions, such as surprisal. Surprisal and salience both affect language processing at different levels, but the relationship between the two has not been adequately elucidated, and the question of whether salience can be reduced to surprisal / predictability is still open. Our review identifies two main challenges in addressing this question: terminological inconsistency and lack of integration between high and low levels of representations in salience-based accounts and surprisal-based accounts. We capitalize upon work in visual cognition in order to orient ourselves in surveying the different facets of the notion of salience in linguistics and their relation with models of surprisal. We find that work on salience highlights aspects of linguistic communication that models of surprisal tend to overlook, namely the role of attention and relevance to current goals, and we argue that the Predictive Coding framework provides a unified view which can account for the role played by attention and predictability at different levels of processing and which can clarify the interplay between low and high levels of processes and between predictability-driven expectation and attention-driven focus. PMID:27375525

  18. Oleic acid-based gemini surfactants with carboxylic acid headgroups.

    PubMed

    Sakai, Kenichi; Umemoto, Naoki; Matsuda, Wataru; Takamatsu, Yuichiro; Matsumoto, Mutsuyoshi; Sakai, Hideki; Abe, Masahiko

    2011-01-01

    Anionic gemini surfactants with carboxylic acid headgroups have been synthesized from oleic acid. The hydrocarbon chain is covalently bound to the terminal carbonyl group of oleic acid via an ester bond, and the carboxylic acid headgroups are introduced to the cis double bond of oleic acid via disuccinyl units. The surfactants exhibit pH-dependent protonation-deprotonation behavior in aqueous solutions. In alkaline solutions (pH 9 in the presence of 10 mmol dm(-3) NaCl as the background electrolyte), the surfactants can lower the surface tension as well as form molecular assemblies, even in the region of low surfactant concentrations. Under acidic (pH 3) or neutral (pH 6-7) conditions, the surfactants are intrinsically insoluble in aqueous media and form a monolayer at the air/water interface. In this study, we have investigated physicochemical properties such as the function of the hydrocarbon chain length by means of static surface tension, pyrene fluorescence, dynamic light scattering, surface pressure-area isotherms, and infrared external reflection measurements.

  19. Accounting for estimated IQ in neuropsychological test performance with regression-based techniques.

    PubMed

    Testa, S Marc; Winicki, Jessica M; Pearlson, Godfrey D; Gordon, Barry; Schretlen, David J

    2009-11-01

    Regression-based normative techniques account for variability in test performance associated with multiple predictor variables and generate expected scores based on algebraic equations. Using this approach, we show that estimated IQ, based on oral word reading, accounts for 1-9% of the variability beyond that explained by individual differences in age, sex, race, and years of education for most cognitive measures. These results confirm that adding estimated "premorbid" IQ to demographic predictors in multiple regression models can incrementally improve the accuracy with which regression-based norms (RBNs) benchmark expected neuropsychological test performance in healthy adults. It remains to be seen whether the incremental variance in test performance explained by estimated "premorbid" IQ translates to improved diagnostic accuracy in patient samples. We describe these methods, and illustrate the step-by-step application of RBNs with two cases. We also discuss the rationale, assumptions, and caveats of this approach. More broadly, we note that adjusting test scores for age and other characteristics might actually decrease the accuracy with which test performance predicts absolute criteria, such as the ability to drive or live independently.

  20. Deciding Who Decides Questions at the Intersection of School Finance Reform Litigation and Standards-Based Accountability Policies

    ERIC Educational Resources Information Center

    Superfine, Benjamin Michael

    2009-01-01

    Courts hearing school finance reform cases have recently begun to consider several issues related to standards-based accountability policies. This convergence of school finance reform litigation and standards-based accountability policies represents a chance for the courts to reallocate decision-making authority for each type of reform across the…

  1. Identifying a base in a nucleic acid

    DOEpatents

    Fodor, Stephen P. A.; Lipshutz, Robert J.; Huang, Xiaohua

    2005-02-08

    Devices and techniques for hybridization of nucleic acids and for determining the sequence of nucleic acids. Arrays of nucleic acids are formed by techniques, preferably high resolution, light-directed techniques. Positions of hybridization of a target nucleic acid are determined by, e.g., epifluorescence microscopy. Devices and techniques are proposed to determine the sequence of a target nucleic acid more efficiently and more quickly through such synthesis and detection techniques.

  2. Computer-based accountability system (Phase I) for special nuclear materials at Argonne-West

    SciTech Connect

    Ingermanson, R.S.; Proctor, A.E.

    1982-05-01

    An automated accountability system for special nuclear materials (SNM) is under development at Argonne National Laboratory-West. Phase I of the development effort has established the following basic features of the system: a unique file organization allows rapid updating or retrieval of the status of various SNM, based on batch numbers, storage location, serial number, or other attributes. Access to the program is controlled by an interactive user interface that can be easily understood by operators who have had no prior background in electronic data processing. Extensive use of structured programming techniques make the software package easy to understand and to modify for specific applications. All routines are written in FORTRAN.

  3. Polarity based fractionation of fulvic acids.

    PubMed

    Li, Aimin; Hu, Jundong; Li, Wenhui; Zhang, Wei; Wang, Xuejun

    2009-11-01

    Fulvic acids from the soil of Peking University (PF) and a Nordic river (NF) were separated into well defined sub-fractions using sequential elution techniques based on eluent polarity. The chemical properties of the fractions including: PF1 and NF1 (eluted by 0.01 M HCl), PF2 and NF2 (eluted by 0.01 M HCl+20% methanol), PF3 and NF3 (eluted by 0.01 M HCl+40% methanol), and PF4 and NF4 (eluted by 100% methanol), were characterized using UV-Visible spectroscopy, elemental analysis and (13)C NMR. The results showed that the UV absorptions of the elution peaks at 280 nm (A280) increased from PF2 to PF4 and NF2 to NF4. No elution peaks were observed for PF1 and NF1. The carbon contents increased from 43.34% to 51.90% and 43.06% to 53.26% while the oxygen contents decreased from 46.39% to 36.76% and 49.76% to 40.03% for PF1-PF4 and NF1-NF4, respectively. As a polarity indicator, the (O+N)/C ratio for PF1-PF4 and NF1-NF4 decreased from 0.88 to 0.62 and 0.89 to 0.58, respectively. The aromatic carbon content increased from PF1 to PF4 and NF1 to NF4, suggesting an increase of the hydrophobicity of these fractions. The polarity was positively related to the ratio of UV absorption at 250 nm and 365 nm (E2/E3), and negatively related to the aromaticity. A high positive relationship between the aromaticity and E2/E3 of fulvic acid fractions was also obtained. The use of an eluent with a decreasing polarity allowed to providing simpler fractions of soil and aquatic fulvic acids.

  4. A blue/green water-based accounting framework for assessment of water security

    NASA Astrophysics Data System (ADS)

    Rodrigues, Dulce B. B.; Gupta, Hoshin V.; Mendiondo, Eduardo M.

    2014-09-01

    A comprehensive assessment of water security can incorporate several water-related concepts, while accounting for Blue and Green Water (BW and GW) types defined in accordance with the hydrological processes involved. Here we demonstrate how a quantitative analysis of provision probability and use of BW and GW can be conducted, so as to provide indicators of water scarcity and vulnerability at the basin level. To illustrate the approach, we use the Soil and Water Assessment Tool (SWAT) to model the hydrology of an agricultural basin (291 km2) within the Cantareira Water Supply System in Brazil. To provide a more comprehensive basis for decision making, we analyze the BW and GW-Footprint components against probabilistic levels (50th and 30th percentile) of freshwater availability for human activities, during a 23 year period. Several contrasting situations of BW provision are distinguished, using different hydrological-based methodologies for specifying monthly Environmental Flow Requirements (EFRs), and the risk of natural EFR violation is evaluated by use of a freshwater provision index. Our results reveal clear spatial and temporal patterns of water scarcity and vulnerability levels within the basin. Taking into account conservation targets for the basin, it appears that the more restrictive EFR methods are more appropriate than the method currently employed at the study basin. The blue/green water-based accounting framework developed here provides a useful integration of hydrologic, ecosystem and human needs information on a monthly basis, thereby improving our understanding of how and where water-related threats to human and aquatic ecosystem security can arise.

  5. Polymer gel dosimeter based on itaconic acid.

    PubMed

    Mattea, Facundo; Chacón, David; Vedelago, José; Valente, Mauro; Strumia, Miriam C

    2015-11-01

    A new polymeric dosimeter based on itaconic acid and N, N'-methylenebisacrylamide was studied. The preparation method, compositions of monomer and crosslinking agent and the presence of oxygen in the dosimetric system were analyzed. The resulting materials were irradiated with an X-ray tube at 158cGy/min, 226cGymin and 298cGy/min with doses up to 1000Gy. The dosimeters presented a linear response in the dose range 75-1000Gy, sensitivities of 0.037 1/Gyat 298cGy/min and an increase in the sensitivity with lower dose rates. One of the most relevant outcomes in this study was obtaining different monomer to crosslinker inclusion in the formed gel for the dosimeters where oxygen was purged during the preparation method. This effect has not been reported in other typical dosimeters and could be attributed to the large differences in the reactivity among these species.

  6. Greenhouse Gas Emissions Accounting of Urban Residential Consumption: A Household Survey Based Approach

    PubMed Central

    Lin, Tao; Yu, Yunjun; Bai, Xuemei; Feng, Ling; Wang, Jin

    2013-01-01

    Devising policies for a low carbon city requires a careful understanding of the characteristics of urban residential lifestyle and consumption. The production-based accounting approach based on top-down statistical data has a limited ability to reflect the total greenhouse gas (GHG) emissions from residential consumption. In this paper, we present a survey-based GHG emissions accounting methodology for urban residential consumption, and apply it in Xiamen City, a rapidly urbanizing coastal city in southeast China. Based on this, the main influencing factors determining residential GHG emissions at the household and community scale are identified, and the typical profiles of low, medium and high GHG emission households and communities are identified. Up to 70% of household GHG emissions are from regional and national activities that support household consumption including the supply of energy and building materials, while 17% are from urban level basic services and supplies such as sewage treatment and solid waste management, and only 13% are direct emissions from household consumption. Housing area and household size are the two main factors determining GHG emissions from residential consumption at the household scale, while average housing area and building height were the main factors at the community scale. Our results show a large disparity in GHG emissions profiles among different households, with high GHG emissions households emitting about five times more than low GHG emissions households. Emissions from high GHG emissions communities are about twice as high as from low GHG emissions communities. Our findings can contribute to better tailored and targeted policies aimed at reducing household GHG emissions, and developing low GHG emissions residential communities in China. PMID:23405187

  7. Greenhouse gas emissions accounting of urban residential consumption: a household survey based approach.

    PubMed

    Lin, Tao; Yu, Yunjun; Bai, Xuemei; Feng, Ling; Wang, Jin

    2013-01-01

    Devising policies for a low carbon city requires a careful understanding of the characteristics of urban residential lifestyle and consumption. The production-based accounting approach based on top-down statistical data has a limited ability to reflect the total greenhouse gas (GHG) emissions from residential consumption. In this paper, we present a survey-based GHG emissions accounting methodology for urban residential consumption, and apply it in Xiamen City, a rapidly urbanizing coastal city in southeast China. Based on this, the main influencing factors determining residential GHG emissions at the household and community scale are identified, and the typical profiles of low, medium and high GHG emission households and communities are identified. Up to 70% of household GHG emissions are from regional and national activities that support household consumption including the supply of energy and building materials, while 17% are from urban level basic services and supplies such as sewage treatment and solid waste management, and only 13% are direct emissions from household consumption. Housing area and household size are the two main factors determining GHG emissions from residential consumption at the household scale, while average housing area and building height were the main factors at the community scale. Our results show a large disparity in GHG emissions profiles among different households, with high GHG emissions households emitting about five times more than low GHG emissions households. Emissions from high GHG emissions communities are about twice as high as from low GHG emissions communities. Our findings can contribute to better tailored and targeted policies aimed at reducing household GHG emissions, and developing low GHG emissions residential communities in China.

  8. Is comprehension necessary for error detection? A conflict-based account of monitoring in speech production

    PubMed Central

    Nozari, Nazbanou; Dell, Gary S.; Schwartz, Myrna F.

    2011-01-01

    Despite the existence of speech errors, verbal communication is successful because speakers can detect (and correct) their errors. The standard theory of speech-error detection, the perceptual-loop account, posits that the comprehension system monitors production output for errors. Such a comprehension-based monitor, however, cannot explain the double dissociation between comprehension and error-detection ability observed in the aphasic patients. We propose a new theory of speech-error detection which is instead based on the production process itself. The theory borrows from studies of forced-choice-response tasks the notion that error detection is accomplished by monitoring response conflict via a frontal brain structure, such as the anterior cingulate cortex. We adapt this idea to the two-step model of word production, and test the model-derived predictions on a sample of aphasic patients. Our results show a strong correlation between patients’ error-detection ability and the model’s characterization of their production skills, and no significant correlation between error detection and comprehension measures, thus supporting a production-based monitor, generally, and the implemented conflict-based monitor in particular. The successful application of the conflict-based theory to error-detection in linguistic, as well as non-linguistic domains points to a domain-general monitoring system. PMID:21652015

  9. Acid-base bifunctional catalytic surfaces for nucleophilic addition reactions.

    PubMed

    Motokura, Ken; Tada, Mizuki; Iwasawa, Yasuhiro

    2008-09-01

    This article illustrates the modification of oxide surfaces with organic amine functional groups to create acid-base bifunctional catalysts, summarizing our previous reports and also presenting new data. Immobilization of organic amines as bases on inorganic solid-acid surfaces afforded highly active acid-base bifunctional catalysts, which enabled various organic transformations including C--C coupling reactions, though these reactions did not proceed with either the homogeneous amine precursors or the acidic supports alone. Spectroscopic characterization, such as by solid-state MAS NMR and FTIR, revealed not only the interactions between acidic and basic sites but also bifunctional catalytic reaction mechanisms.

  10. A Commentary on "Updating the Duplex Design for Test-Based Accountability in the Twenty-First Century"

    ERIC Educational Resources Information Center

    Brandt, Steffen

    2010-01-01

    This article presents the author's commentary on "Updating the Duplex Design for Test-Based Accountability in the Twenty-First Century," in which Isaac I. Bejar and E. Aurora Graf propose the application of a test design--the duplex design (which was proposed in 1988 by Bock and Mislevy) for application in current accountability assessments.…

  11. Thermochemical comparisons of homogeneous and heterogeneous acids and bases. 1. Sulfonic acid solutions and resins as prototype Broensted acids

    SciTech Connect

    Arnett, E.M.; Haaksma, R.A.; Chawla, B.; Healy, M.H.

    1986-08-06

    Heats of ionization by thermometric titration for a series of bases (or acids) can be used to compare solid acids (or bases) with liquid analogues bearing the same functionalities in homogeneous solutions. The method is demonstrated for Broensted acids by reacting a series of substituted nitrogen bases with solutions of p-toluenesulfonic acid (PTSA) in acetonitrile and with suspensions of the microporous polymeric arylsulfonic acid resin-Dowex 50W-X8 in the same solvent. Under well-controlled anhydrous conditions there is a good correlation (r = 0.992) between the heats of reaction of the bases with the homogeneous and heterogeneous acid systems, but the homogeneous system gives a more exothermic interaction by 3-4 kcal mol/sup -1/ for a series of 29 substituted pyrimidines, anilines, and some other amines. This difference may be attributed to homohydrogen bonding interactions between excess acid and sulfonate anion sites which are more restricted geometrically in the resin than in solution. Other factors which affect the enthalpy change for the acid-base interaction are the acid/base ratio, the water content of the sulfonic acid, the solvent, and the resin structure (e.g., microporous vs. macroporous). Steric hindrance in the base does not differentiate solid from homogeneous acid. In addition to the use of titration calorimetry, heats of immersion are reported for the Dowex-arylsulfonic acid resins and the Nafion-perfluorinated sulfonic acid resin in a series of basic liquids. The results are compared with each other and with those from a previous study of several varieties of coal.

  12. Base pairing and base mis-pairing in nucleic acids

    NASA Technical Reports Server (NTRS)

    Wang, A. H. J.; Rich, A.

    1986-01-01

    In recent years we have learned that DNA is conformationally active. It can exist in a number of different stable conformations including both right-handed and left-handed forms. Using single crystal X-ray diffraction analysis we are able to discover not only additional conformations of the nucleic acids but also different types of hydrogen bonded base-base interactions. Although Watson-Crick base pairings are the predominant type of interaction in double helical DNA, they are not the only types. Recently, we have been able to examine mismatching of guanine-thymine base pairs in left-handed Z-DNA at atomic resolution (1A). A minimum amount of distortion of the sugar phosphate backbone is found in the G x T pairing in which the bases are held together by two hydrogen bonds in the wobble pairing interaction. Because of the high resolution of the analysis we can visualize water molecules which fill in to accommodate the other hydrogen bonding positions in the bases which are not used in the base-base interactions. Studies on other DNA oligomers have revealed that other types of non-Watson-Crick hydrogen bonding interactions can occur. In the structure of a DNA octamer with the sequence d(GCGTACGC) complexed to an antibiotic triostin A, it was found that the two central AT base pairs are held together by Hoogsteen rather than Watson-Crick base pairs. Similarly, the G x C base pairs at the ends are also Hoogsteen rather than Watson-Crick pairing. Hoogsteen base pairs make a modified helix which is distinct from the Watson-Crick double helix.

  13. Keeping Accountability Systems Accountable

    ERIC Educational Resources Information Center

    Foote, Martha

    2007-01-01

    The standards and accountability movement in education has undeniably transformed schooling throughout the United States. Even before President Bush signed the No Child Left Behind (NCLB) Act into law in January 2002, mandating annual public school testing in English and math for grades 3-8 and once in high school, most states had already…

  14. 26 CFR 1.801-8 - Contracts with reserves based on segregated asset accounts.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... general asset accounts and realized short-term capital gains of $12,000 attributable to its segregated asset accounts. For the taxable year 1962, the excess of the net short-term capital gain ($10,000+$12... attributable to its segregated asset accounts. For the taxable year 1962, the excess of the net...

  15. Patterns of Learning in the Accountancy Profession under an Output-Based Continuing Professional Development Scheme

    ERIC Educational Resources Information Center

    Lindsay, Hilary

    2012-01-01

    Since 2004, professional accountancy bodies in membership of the International Federation of Accountants (IFAC) have been required to adopt mandatory continuing professional development (CPD) schemes. This research explores the learning activities of members of the Institute of Chartered Accountants in England and Wales (ICAEW) which introduced an…

  16. How States Can Hold Schools Accountable: The Strong Schools Model of Standards-Based Reform.

    ERIC Educational Resources Information Center

    Brooks, Sarah R.

    Few states have overcome the political and practical obstacles to implementing a clear, feasible, comprehensive accountability system. The University of Washington's Center on Reinventing Public Education reviewed experiences from state accountability efforts. Workable accountability systems focus on results, clarify goals and roles, and…

  17. Are carboxyl groups the most acidic sites in amino acids? Gas-phase acidities, photoelectron spectra, and computations on tyrosine, p-hydroxybenzoic acid, and their conjugate bases.

    PubMed

    Tian, Zhixin; Wang, Xue-Bin; Wang, Lai-Sheng; Kass, Steven R

    2009-01-28

    Deprotonation of tyrosine in the gas phase was found to occur preferentially at the phenolic site, and the conjugate base consists of a 70:30 mixture of phenoxide and carboxylate anions at equilibrium. This result was established by developing a chemical probe for differentiating these two isomers, and the presence of both ions was confirmed by photoelectron spectroscopy. Equilibrium acidity measurements on tyrosine indicated that deltaG(acid)(o) = 332.5 +/- 1.5 kcal mol(-1) and deltaH(acid)(o) = 340.7 +/- 1.5 kcal mol(-1). Photoelectron spectra yielded adiabatic electron detachment energies of 2.70 +/- 0.05 and 3.55 +/- 0.10 eV for the phenoxide and carboxylate anions, respectively. The H/D exchange behavior of deprotonated tyrosine was examined using three different alcohols (CF3CH2OD, C6H5CH2OD, and CH3CH2OD), and incorporation of up to three deuterium atoms was observed. Two pathways are proposed to account for these results, and all of the experimental findings are supplemented with B3LYP/aug-cc-pVDZ and G3B3 calculations. In addition, it was found that electrospray ionization of tyrosine from a 3:1 (v/v) CH3OH/H2O solution using a commercial source produces a deprotonated [M-H]- anion with the gas-phase equilibrium composition rather than the structure of the ion that exists in aqueous media. Electrospray ionization from acetonitrile, however, leads largely to the liquid-phase (carboxylate) structure. A control molecule, p-hydroxybenzoic acid, was found to behave in a similar manner. Thus, the electrospray conditions that are employed for the analysis of a compound can alter the isomeric composition of the resulting anion.

  18. A Blue/Green Water-based Accounting Framework for Assessment of Water Security

    NASA Astrophysics Data System (ADS)

    Rodrigues, D. B.; Gupta, H. V.; Mendiondo, E. M.

    2013-12-01

    A comprehensive assessment of water security can incorporate several water-related concepts, including provisioning and support for freshwater ecosystem services, water footprint, water scarcity, and water vulnerability, while accounting for Blue and Green Water (BW and GW) flows defined in accordance with the hydrological processes involved. Here, we demonstrate how a quantitative analysis of provisioning and demand (in terms of water footprint) for BW and GW ecosystem services can be conducted, so as to provide indicators of water scarcity and vulnerability at the basin level. To illustrate the approach, we use the Soil and Water Assessment Tool (SWAT) to model the hydrology of an agricultural basin (291 sq.km) within the Cantareira water supply system in Brazil. To provide a more comprehensive basis for decision-making, we compute the BW provision using three different hydrological-based methods for specifying monthly Environmental Flow Requirements (EFRs) for 23 year-period. The current BW-Footprint was defined using surface water rights for reference year 2012. Then we analyzed the BW- and GW-Footprints against long-term series of monthly values of freshwater availability. Our results reveal clear spatial and temporal patterns of water scarcity and vulnerability levels within the basin, and help to distinguish between human and natural reasons (drought) for conditions of insecurity. The Blue/Green water-based accounting framework developed here can be benchmarked at a range of spatial scales, thereby improving our understanding of how and where water-related threats to human and aquatic ecosystem security can arise. Future investigation will be necessary to better understand the intra-annual variability of blue water demand and to evaluate the impacts of uncertainties associated with a) the water rights database, b) the effects of climate change projections on blue and green freshwater provision.

  19. An APEL Tool Based CPU Usage Accounting Infrastructure for Large Scale Computing Grids

    NASA Astrophysics Data System (ADS)

    Jiang, Ming; Novales, Cristina Del Cano; Mathieu, Gilles; Casson, John; Rogers, William; Gordon, John

    The APEL (Accounting Processor for Event Logs) is the fundamental tool for the CPU usage accounting infrastructure deployed within the WLCG and EGEE Grids. In these Grids, jobs are submitted by users to computing resources via a Grid Resource Broker (e.g. gLite Workload Management System). As a log processing tool, APEL interprets logs of Grid gatekeeper (e.g. globus) and batch system logs (e.g. PBS, LSF, SGE and Condor) to produce CPU job accounting records identified with Grid identities. These records provide a complete description of usage of computing resources by user's jobs. APEL publishes accounting records into an accounting record repository at a Grid Operations Centre (GOC) for the access from a GUI web tool. The functions of log files parsing, records generation and publication are implemented by the APEL Parser, APEL Core, and APEL Publisher component respectively. Within the distributed accounting infrastructure, accounting records are transported from APEL Publishers at Grid sites to either a regionalised accounting system or the central one by choice via a common ActiveMQ message broker network. This provides an open transport layer for other accounting systems to publish relevant accounting data to a central accounting repository via a unified interface provided an APEL Publisher and also will give regional/National Grid Initiatives (NGIs) Grids the flexibility in their choice of accounting system. The robust and secure delivery of accounting record messages at an NGI level and between NGI accounting instances and the central one are achieved by using configurable APEL Publishers and an ActiveMQ message broker network.

  20. Weak vs Strong Acids and Bases: The Football Analogy

    NASA Astrophysics Data System (ADS)

    Silverstein, Todd P.

    2000-07-01

    An important topic in any introductory chemistry course is that of acids and bases. Students generally have no trouble learning the Brønsted-Lowry definition of an acid as a proton donor and a base as a proton acceptor. Problems often arise, however, when chemistry teachers attempt to explain the difference between weak and strong acids, and between weak and strong bases. For acids in aqueous solution, discussing complete in contrast to partial ionization works well for those with a strong grasp of the equilibrium concept, but for many students it does not seem to do the trick. Partial ionization may not evoke much in the mind of a "visual learner". Accordingly, I have developed a football analogy for acids and bases in which acids are compared to quarterbacks, whose job is to get rid of the ball (H+). A strong acid, like an excellent quarterback, delivers the ball effectively; a weak acid, like a poor quarterback, is often left holding the ball. Furthermore, bases may be likened to wide receivers, whose job is to catch and hold onto the ball (H+). A strong base, like an excellent wide receiver, holds onto the ball; a weak base, like a poor receiver, often drops the ball. The concept of throwing and catching a ball is easy to visualize and the analogy to acids and bases can help even students unfamiliar with the mores of the gridiron to comprehend the mores of aqueous protons.

  1. Acid-Base Pairs in Lewis Acidic Zeolites Promote Direct Aldol Reactions by Soft Enolization.

    PubMed

    Lewis, Jennifer D; Van de Vyver, Stijn; Román-Leshkov, Yuriy

    2015-08-17

    Hf-, Sn-, and Zr-Beta zeolites catalyze the cross-aldol condensation of aromatic aldehydes with acetone under mild reaction conditions with near quantitative yields. NMR studies with isotopically labeled molecules confirm that acid-base pairs in the Si-O-M framework ensemble promote soft enolization through α-proton abstraction. The Lewis acidic zeolites maintain activity in the presence of water and, unlike traditional base catalysts, in acidic solutions.

  2. Determination of acidity constants of acid-base indicators by second-derivative spectrophotometry

    NASA Astrophysics Data System (ADS)

    Kara, Derya; Alkan, Mahir

    2000-12-01

    A method for calculation of acid-base dissociation constants of monoprotic weak organic acids whose acid and base species have overlapping spectra from absorptiometric and pH measurements is described. It has been shown that the second-derivative spectrophotometry can effectively be used for determining the dissociation constants, when dissociation constants obtained for methyl orange and bromothymol blue were compared with the values given in the literature.

  3. Chip-based sequencing nucleic acids

    DOEpatents

    Beer, Neil Reginald

    2014-08-26

    A system for fast DNA sequencing by amplification of genetic material within microreactors, denaturing, demulsifying, and then sequencing the material, while retaining it in a PCR/sequencing zone by a magnetic field. One embodiment includes sequencing nucleic acids on a microchip that includes a microchannel flow channel in the microchip. The nucleic acids are isolated and hybridized to magnetic nanoparticles or to magnetic polystyrene-coated beads. Microreactor droplets are formed in the microchannel flow channel. The microreactor droplets containing the nucleic acids and the magnetic nanoparticles are retained in a magnetic trap in the microchannel flow channel and sequenced.

  4. Acid-Base Chemistry of White Wine: Analytical Characterisation and Chemical Modelling

    PubMed Central

    Prenesti, Enrico; Berto, Silvia; Toso, Simona; Daniele, Pier Giuseppe

    2012-01-01

    A chemical model of the acid-base properties is optimized for each white wine under study, together with the calculation of their ionic strength, taking into account the contributions of all significant ionic species (strong electrolytes and weak one sensitive to the chemical equilibria). Coupling the HPLC-IEC and HPLC-RP methods, we are able to quantify up to 12 carboxylic acids, the most relevant substances responsible of the acid-base equilibria of wine. The analytical concentration of carboxylic acids and of other acid-base active substances was used as input, with the total acidity, for the chemical modelling step of the study based on the contemporary treatment of overlapped protonation equilibria. New protonation constants were refined (L-lactic and succinic acids) with respect to our previous investigation on red wines. Attention was paid for mixed solvent (ethanol-water mixture), ionic strength, and temperature to ensure a thermodynamic level to the study. Validation of the chemical model optimized is achieved by way of conductometric measurements and using a synthetic “wine” especially adapted for testing. PMID:22566762

  5. Acid-base chemistry of white wine: analytical characterisation and chemical modelling.

    PubMed

    Prenesti, Enrico; Berto, Silvia; Toso, Simona; Daniele, Pier Giuseppe

    2012-01-01

    A chemical model of the acid-base properties is optimized for each white wine under study, together with the calculation of their ionic strength, taking into account the contributions of all significant ionic species (strong electrolytes and weak one sensitive to the chemical equilibria). Coupling the HPLC-IEC and HPLC-RP methods, we are able to quantify up to 12 carboxylic acids, the most relevant substances responsible of the acid-base equilibria of wine. The analytical concentration of carboxylic acids and of other acid-base active substances was used as input, with the total acidity, for the chemical modelling step of the study based on the contemporary treatment of overlapped protonation equilibria. New protonation constants were refined (L-lactic and succinic acids) with respect to our previous investigation on red wines. Attention was paid for mixed solvent (ethanol-water mixture), ionic strength, and temperature to ensure a thermodynamic level to the study. Validation of the chemical model optimized is achieved by way of conductometric measurements and using a synthetic "wine" especially adapted for testing.

  6. Assessment of acid-base balance. Stewart's approach.

    PubMed

    Fores-Novales, B; Diez-Fores, P; Aguilera-Celorrio, L J

    2016-04-01

    The study of acid-base equilibrium, its regulation and its interpretation have been a source of debate since the beginning of 20th century. Most accepted and commonly used analyses are based on pH, a notion first introduced by Sorensen in 1909, and on the Henderson-Hasselbalch equation (1916). Since then new concepts have been development in order to complete and make easier the understanding of acid-base disorders. In the early 1980's Peter Stewart brought the traditional interpretation of acid-base disturbances into question and proposed a new method. This innovative approach seems more suitable for studying acid-base abnormalities in critically ill patients. The aim of this paper is to update acid-base concepts, methods, limitations and applications.

  7. A statistical model-based technique for accounting for prostate gland deformation in endorectal coil-based MR imaging.

    PubMed

    Tahmasebi, Amir M; Sharifi, Reza; Agarwal, Harsh K; Turkbey, Baris; Bernardo, Marcelino; Choyke, Peter; Pinto, Peter; Wood, Bradford; Kruecker, Jochen

    2012-01-01

    In prostate brachytherapy procedures, combining high-resolution endorectal coil (ERC)-MRI with Computed Tomography (CT) images has shown to improve the diagnostic specificity for malignant tumors. Despite such advantage, there exists a major complication in fusion of the two imaging modalities due to the deformation of the prostate shape in ERC-MRI. Conventionally, nonlinear deformable registration techniques have been utilized to account for such deformation. In this work, we present a model-based technique for accounting for the deformation of the prostate gland in ERC-MR imaging, in which a unique deformation vector is estimated for every point within the prostate gland. Modes of deformation for every point in the prostate are statistically identified using a set of MR-based training set (with and without ERC-MRI). Deformation of the prostate from a deformed (ERC-MRI) to a non-deformed state in a different modality (CT) is then realized by first calculating partial deformation information for a limited number of points (such as surface points or anatomical landmarks) and then utilizing the calculated deformation from a subset of the points to determine the coefficient values for the modes of deformations provided by the statistical deformation model. Using a leave-one-out cross-validation, our results demonstrated a mean estimation error of 1mm for a MR-to-MR registration.

  8. Phosphonic acid based ion exchange resins

    DOEpatents

    Horwitz, E. Philip; Alexandratos, Spiro D.; Gatrone, Ralph C.; Chiarizia, Ronato

    1996-01-01

    An ion exchange resin for extracting metal ions from a liquid waste stream. An ion exchange resin is prepared by copolymerizing a vinylidene diphosphonic acid with styrene, acrylonitrile and divinylbenzene.

  9. Phosphonic acid based ion exchange resins

    DOEpatents

    Horwitz, E. Philip; Alexandratos, Spiro D.; Gatrone, Ralph C.; Chiarizia, Ronato

    1994-01-01

    An ion exchange resin for extracting metal ions from a liquid waste stream. An ion exchange resin is prepared by copolymerizing a vinylidene disphosphonic acid with styrene, acrylonitrile and divinylbenzene.

  10. Calcium-based Lewis acid catalysts.

    PubMed

    Begouin, Jeanne-Marie; Niggemann, Meike

    2013-06-17

    Recently, Lewis acidic calcium salts bearing weakly coordinating anions such as Ca(NTf₂)₂, Ca(OTf)₂, CaF₂ and Ca[OCH(CF₃)₂]₂ have been discovered as catalysts for the transformation of alcohols, olefins and carbonyl compounds. High stability towards air and moisture, selectivity and high reactivity under mild reaction conditions render these catalysts a sustainable and mild alternative to transition metals, rare-earth metals or strong Brønsted acids.

  11. Advances in nucleic acid-based detection methods.

    PubMed Central

    Wolcott, M J

    1992-01-01

    Laboratory techniques based on nucleic acid methods have increased in popularity over the last decade with clinical microbiologists and other laboratory scientists who are concerned with the diagnosis of infectious agents. This increase in popularity is a result primarily of advances made in nucleic acid amplification and detection techniques. Polymerase chain reaction, the original nucleic acid amplification technique, changed the way many people viewed and used nucleic acid techniques in clinical settings. After the potential of polymerase chain reaction became apparent, other methods of nucleic acid amplification and detection were developed. These alternative nucleic acid amplification methods may become serious contenders for application to routine laboratory analyses. This review presents some background information on nucleic acid analyses that might be used in clinical and anatomical laboratories and describes some recent advances in the amplification and detection of nucleic acids. PMID:1423216

  12. An agent-based simulation model to study accountable care organizations.

    PubMed

    Liu, Pai; Wu, Shinyi

    2016-03-01

    Creating accountable care organizations (ACOs) has been widely discussed as a strategy to control rapidly rising healthcare costs and improve quality of care; however, building an effective ACO is a complex process involving multiple stakeholders (payers, providers, patients) with their own interests. Also, implementation of an ACO is costly in terms of time and money. Immature design could cause safety hazards. Therefore, there is a need for analytical model-based decision-support tools that can predict the outcomes of different strategies to facilitate ACO design and implementation. In this study, an agent-based simulation model was developed to study ACOs that considers payers, healthcare providers, and patients as agents under the shared saving payment model of care for congestive heart failure (CHF), one of the most expensive causes of sometimes preventable hospitalizations. The agent-based simulation model has identified the critical determinants for the payment model design that can motivate provider behavior changes to achieve maximum financial and quality outcomes of an ACO. The results show nonlinear provider behavior change patterns corresponding to changes in payment model designs. The outcomes vary by providers with different quality or financial priorities, and are most sensitive to the cost-effectiveness of CHF interventions that an ACO implements. This study demonstrates an increasingly important method to construct a healthcare system analytics model that can help inform health policy and healthcare management decisions. The study also points out that the likely success of an ACO is interdependent with payment model design, provider characteristics, and cost and effectiveness of healthcare interventions.

  13. The Roles of Acids and Bases in Enzyme Catalysis

    ERIC Educational Resources Information Center

    Weiss, Hilton M.

    2007-01-01

    Many organic reactions are catalyzed by strong acids or bases that protonate or deprotonate neutral reactants leading to reactive cations or anions that proceed to products. In enzyme reactions, only weak acids and bases are available to hydrogen bond to reactants and to transfer protons in response to developing charges. Understanding this…

  14. What is the Ultimate Goal in Acid-Base Regulation?

    ERIC Educational Resources Information Center

    Balakrishnan, Selvakumar; Gopalakrishnan, Maya; Alagesan, Murali; Prakash, E. Sankaranarayanan

    2007-01-01

    It is common to see chapters on acid-base physiology state that the goal of acid-base regulatory mechanisms is to maintain the pH of arterial plasma and not arterial PCO [subscript 2] (Pa[subscript CO[subscript 2

  15. Acid-base properties of titanium-antimony oxides catalysts

    SciTech Connect

    Zenkovets, G.A.; Paukshtis, E.A.; Tarasova, D.V.; Yurchenko, E.N.

    1982-06-01

    The acid-base properties of titanium-antimony oxide catalysts were studied by the methods of back titration and ir spectroscopy. The interrelationship between the acid-base and catalytic properties in the oxidative ammonolysis of propylene was discussed. 3 figures, 1 table.

  16. A Closer Look at Acid-Base Olfactory Titrations

    ERIC Educational Resources Information Center

    Neppel, Kerry; Oliver-Hoyo, Maria T.; Queen, Connie; Reed, Nicole

    2005-01-01

    Olfactory titrations using raw onions and eugenol as acid-base indicators are reported. An in-depth investigation on olfactory titrations is presented to include requirements for potential olfactory indicators and protocols for using garlic, onions, and vanillin as acid-base olfactory indicators are tested.

  17. Luminol as a fluorescent acid-base indicator.

    PubMed

    Erdey, L; Buzás, I; Vigh, K

    1966-03-01

    The acid and base dissociation constants of luminol are determined at various ionic strengths. The transition interval occurs at pH 7.7-9.0, therefore luminol is a fluorescent indicator for the titration of strong and weak acids and strong bases. Its value as an indicator is established by titrating milk, red wine and cherry juice.

  18. Proton defect solvation and dynamics in aqueous acid and base.

    PubMed

    Kale, Seyit; Herzfeld, Judith

    2012-10-29

    Easy come, easy go: LEWIS, a new model of reactive and polarizable water that enables the simulation of a statistically reliable number of proton hopping events in aqueous acid and base at concentrations of practical interest, is used to evaluate proton transfer intermediates in aqueous acid and base (picture, left and right, respectively).

  19. Connecting Acids and Bases with Encapsulation... and Chemistry with Nanotechnology

    ERIC Educational Resources Information Center

    Criswell, Brett

    2007-01-01

    The features and the development of various new acids and bases activity sets that combines chemistry with nanotechnology are being described. These sets lead to the generation of many nanotechnology-based pharmaceuticals for the treatment of various diseases.

  20. Nitric acid: modeling osmotic coefficients and acid-base dissociation using the BIMSA theory.

    PubMed

    Ruas, Alexandre; Pochon, Patrick; Simonin, Jean-Pierre; Moisy, Philippe

    2010-11-14

    This work is aimed at a description of the thermodynamic properties of highly concentrated aqueous solutions of nitric acid salts at 25 °C within the binding mean spherical approximation (BIMSA) theory. The predictive capability of this model was examined. First, Raman spectroscopy was used to study the proportion of associated nitric acid as a function of concentration. The corresponding apparent association constant values were compared with literature values. Besides, the BIMSA model, taking into account complex formation, was used to represent literature experimental osmotic coefficient variation with concentration. This theoretical description led to an assessment of the degree of association. The so calculated amount of associated nitric acid coincides accurately with our Raman experimental results up to a high concentration of acid.

  1. Design of a Competency-Based Assessment Model in the Field of Accounting

    ERIC Educational Resources Information Center

    Ciudad-Gómez, Adelaida; Valverde-Berrocoso, Jesús

    2012-01-01

    This paper presents the phases involved in the design of a methodology to contribute both to the acquisition of competencies and to their assessment in the field of Financial Accounting, within the European Higher Education Area (EHEA) framework, which we call MANagement of COMpetence in the areas of Accounting (MANCOMA). Having selected and…

  2. Involving Diverse Communities of Practice to Minimize Unintended Consequences of Test-Based Accountability Systems

    ERIC Educational Resources Information Center

    Behizadeh, Nadia; Engelhard, George, Jr.

    2015-01-01

    In his focus article, Koretz (this issue) argues that accountability has become the primary function of large-scale testing in the United States. He then points out that tests being used for accountability purposes are flawed and that the high-stakes nature of these tests creates a context that encourages score inflation. Koretz is concerned about…

  3. A Computer-Based Simulation of an Acid-Base Titration

    ERIC Educational Resources Information Center

    Boblick, John M.

    1971-01-01

    Reviews the advantages of computer simulated environments for experiments, referring in particular to acid-base titrations. Includes pre-lab instructions and a sample computer printout of a student's use of an acid-base simulation. Ten references. (PR)

  4. Tracking online poker problem gamblers with player account-based gambling data only.

    PubMed

    Luquiens, Amandine; Tanguy, Marie-Laure; Benyamina, Amine; Lagadec, Marthylle; Aubin, Henri-Jean; Reynaud, Michel

    2016-12-01

    The aim was to develop and validate an instrument to track online problem poker gamblers with player account-based gambling data (PABGD). We emailed an invitation to all active poker gamblers on the online gambling service provider Winamax. The 14,261 participants completed the Problem Gambling Severity Index (PGSI). PGSI served as a gold standard to track problem gamblers (i.e., PGSI ≥ 5). We used a stepwise logistic regression to build a predictive model of problem gambling with PABGD, and validated it. Of the sample 18% was composed of online poker problem gamblers. The risk factors of problem gambling included in the predictive model were being male, compulsive, younger than 28 years, making a total deposit > 0 euros, having a mean loss per gambling session > 1.7 euros, losing a total of > 45 euros in the last 30 days, having a total stake > 298 euros, having > 60 gambling sessions in the last 30 days, and multi-tabling. The tracking instrument had a sensitivity of 80%, and a specificity of 50%. The quality of the instrument was good. This study illustrates the feasibility of a method to develop and validate instruments to track online problem gamblers with PABGD only. Copyright © 2016 John Wiley & Sons, Ltd.

  5. Grid-cell-based crop water accounting for the famine early warning system

    USGS Publications Warehouse

    Verdin, J.; Klaver, R.

    2002-01-01

    Rainfall monitoring is a regular activity of food security analysts for sub-Saharan Africa due to the potentially disastrous impact of drought. Crop water accounting schemes are used to track rainfall timing and amounts relative to phenological requirements, to infer water limitation impacts on yield. Unfortunately, many rain gauge reports are available only after significant delays, and the gauge locations leave large gaps in coverage. As an alternative, a grid-cell-based formulation for the water requirement satisfaction index (WRSI) was tested for maize in Southern Africa. Grids of input variables were obtained from remote sensing estimates of rainfall, meteorological models, and digital soil maps. The spatial WRSI was computed for the 1996-97 and 1997-98 growing seasons. Maize yields were estimated by regression and compared with a limited number of reports from the field for the 1996-97 season in Zimbabwe. Agreement at a useful level (r = 0.80) was observed. This is comparable to results from traditional analysis with station data. The findings demonstrate the complementary role that remote sensing, modelling, and geospatial analysis can play in an era when field data collection in sub-Saharan Africa is suffering an unfortunate decline. Published in 2002 by John Wiley & Sons, Ltd.

  6. A Simple Regression-based Approach to Account for Survival Bias in Birth Outcomes Research.

    PubMed

    Tchetgen Tchetgen, Eric J; Phiri, Kelesitse; Shapiro, Roger

    2015-07-01

    In perinatal epidemiology, birth outcomes such as small for gestational age (SGA) may not be observed for a pregnancy ending with a stillbirth. It is then said that SGA is truncated by stillbirth, which may give rise to survival bias when evaluating the effects on SGA of an exposure known also to influence the risk of a stillbirth. In this article, we consider the causal effects of maternal infection with human immunodeficiency virus (HIV) on the risk of SGA, in a sample of pregnant women in Botswana. We hypothesize that previously estimated effects of HIV on SGA may be understated because they fail to appropriately account for the over-representation of live births among HIV negative mothers, relative to HIV positive mothers. A simple yet novel regression-based approach is proposed to adjust effect estimates for survival bias for an outcome that is either continuous or binary. Under certain straightforward assumptions, the approach produces an estimate that may be interpreted as the survivor average causal effect of maternal HIV, which is, the average effect of maternal HIV on SGA among births that would be live irrespective of maternal HIV status. The approach is particularly appealing, because it recovers an exposure effect which is robust to survival bias, even if the association between the risk of SGA and that of a stillbirth cannot be completely explained by adjusting for observed shared risk factors. The approach also gives a formal statistical test of the null hypothesis of no survival bias in the regression framework.

  7. Examining air pollution in China using production- and consumption-based emissions accounting approaches.

    PubMed

    Huo, Hong; Zhang, Qiang; Guan, Dabo; Su, Xin; Zhao, Hongyan; He, Kebin

    2014-12-16

    Two important reasons for China's air pollution are the high emission factors (emission per unit of product) of pollution sources and the high emission intensity (emissions per unit of GDP) of the industrial structure. Therefore, a wide variety of policy measures, including both emission abatement technologies and economic adjustment, must be implemented. To support such measures, this study used the production- and consumption-based emissions accounting approaches to simulate the SO2, NOx, PM2.5, and VOC emissions flows among producers and consumers. This study analyzed the emissions and GDP performance of 36 production sectors. The results showed that the equipment, machinery, and devices manufacturing and construction sectors contributed more than 50% of air pollutant emissions, and most of their products were used for capital formation and export. The service sector had the lowest emission intensities, and its output was mainly consumed by households and the government. In China, the emission intensities of production activities triggered by capital formation and export were approximately twice that of the service sector triggered by final consumption expenditure. This study suggests that China should control air pollution using the following strategies: applying end-of-pipe abatement technologies and using cleaner fuels to further decrease the emission factors associated with rural cooking, electricity generation, and the transportation sector; continuing to limit highly emission-intensive but low value-added exports; developing a plan to reduce construction activities; and increasing the proportion of service GDP in the national economy.

  8. Ammonia Transporters and Their Role in Acid-Base Balance.

    PubMed

    Weiner, I David; Verlander, Jill W

    2017-04-01

    Acid-base homeostasis is critical to maintenance of normal health. Renal ammonia excretion is the quantitatively predominant component of renal net acid excretion, both under basal conditions and in response to acid-base disturbances. Although titratable acid excretion also contributes to renal net acid excretion, the quantitative contribution of titratable acid excretion is less than that of ammonia under basal conditions and is only a minor component of the adaptive response to acid-base disturbances. In contrast to other urinary solutes, ammonia is produced in the kidney and then is selectively transported either into the urine or the renal vein. The proportion of ammonia that the kidney produces that is excreted in the urine varies dramatically in response to physiological stimuli, and only urinary ammonia excretion contributes to acid-base homeostasis. As a result, selective and regulated renal ammonia transport by renal epithelial cells is central to acid-base homeostasis. Both molecular forms of ammonia, NH3 and NH4(+), are transported by specific proteins, and regulation of these transport processes determines the eventual fate of the ammonia produced. In this review, we discuss these issues, and then discuss in detail the specific proteins involved in renal epithelial cell ammonia transport.

  9. Nucleic acid duplexes incorporating a dissociable covalent base pair

    NASA Technical Reports Server (NTRS)

    Gao, K.; Orgel, L. E.; Bada, J. L. (Principal Investigator)

    1999-01-01

    We have used molecular modeling techniques to design a dissociable covalently bonded base pair that can replace a Watson-Crick base pair in a nucleic acid with minimal distortion of the structure of the double helix. We introduced this base pair into a potential precursor of a nucleic acid double helix by chemical synthesis and have demonstrated efficient nonenzymatic template-directed ligation of the free hydroxyl groups of the base pair with appropriate short oligonucleotides. The nonenzymatic ligation reactions, which are characteristic of base paired nucleic acid structures, are abolished when the covalent base pair is reduced and becomes noncoplanar. This suggests that the covalent base pair linking the two strands in the duplex is compatible with a minimally distorted nucleic acid double-helical structure.

  10. Nucleic Acid Duplexes Incorporating a Dissociable Covalent Base Pair

    NASA Astrophysics Data System (ADS)

    Gao, Kui; Orgel, Leslie E.

    1999-12-01

    We have used molecular modeling techniques to design a dissociable covalently bonded base pair that can replace a Watson-Crick base pair in a nucleic acid with minimal distortion of the structure of the double helix. We introduced this base pair into a potential precursor of a nucleic acid double helix by chemical synthesis and have demonstrated efficient nonenzymatic template-directed ligation of the free hydroxyl groups of the base pair with appropriate short oligonucleotides. The nonenzymatic ligation reactions, which are characteristic of base paired nucleic acid structures, are abolished when the covalent base pair is reduced and becomes noncoplanar. This suggests that the covalent base pair linking the two strands in the duplex is compatible with a minimally distorted nucleic acid double-helical structure.

  11. Modeling the Acid-Base Properties of Montmorillonite Edge Surfaces.

    PubMed

    Tournassat, Christophe; Davis, James A; Chiaberge, Christophe; Grangeon, Sylvain; Bourg, Ian C

    2016-12-20

    The surface reactivity of clay minerals remains challenging to characterize because of a duality of adsorption surfaces and mechanisms that does not exist in the case of simple oxide surfaces: edge surfaces of clay minerals have a variable proton surface charge arising from hydroxyl functional groups, whereas basal surfaces have a permanent negative charge arising from isomorphic substitutions. Hence, the relationship between surface charge and surface potential on edge surfaces cannot be described using the Gouy-Chapman relation, because of a spillover of negative electrostatic potential from the basal surface onto the edge surface. While surface complexation models can be modified to account for these features, a predictive fit of experimental data was not possible until recently, because of uncertainty regarding the densities and intrinsic pKa values of edge functional groups. Here, we reexamine this problem in light of new knowledge on intrinsic pKa values obtained over the past decade using ab initio molecular dynamics simulations, and we propose a new formalism to describe edge functional groups. Our simulation results yield reasonable predictions of the best available experimental acid-base titration data.

  12. Acid-base properties of 2-phenethyldithiocarbamoylacetic acid, an antitumor agent

    NASA Astrophysics Data System (ADS)

    Novozhilova, N. E.; Kutina, N. N.; Petukhova, O. A.; Kharitonov, Yu. Ya.

    2013-07-01

    The acid-base properties of the 2-phenethyldithiocarbamoylacetic acid (PET) substance belonging to the class of isothiocyanates and capable of inhibiting the development of tumors on many experimental models were studied. The acidity and hydrolysis constants of the PET substance in ethanol, acetone, aqueous ethanol, and aqueous acetone solutions were determined from the data of potentiometric (pH-metric) titration of ethanol and acetone solutions of PET with aqueous solidum hydroxide at room temperature.

  13. Women of Courage: A Personal Account of a Wilderness-Based Experiential Group for Survivors of Abuse

    ERIC Educational Resources Information Center

    Kelly, Virginia A.

    2006-01-01

    Adventure-based therapy has grown in both scope and popularity. These groups are frequently utilized in the treatment of adolescents with behavioral or substance abuse issues. Less evident is the use of this modality with other populations. Described here is a personal account of the author's participation in a wilderness-based group for women.…

  14. Reactive Distillation for Esterification of Bio-based Organic Acids

    SciTech Connect

    Fields, Nathan; Miller, Dennis J.; Asthana, Navinchandra S.; Kolah, Aspi K.; Vu, Dung; Lira, Carl T.

    2008-09-23

    The following is the final report of the three year research program to convert organic acids to their ethyl esters using reactive distillation. This report details the complete technical activities of research completed at Michigan State University for the period of October 1, 2003 to September 30, 2006, covering both reactive distillation research and development and the underlying thermodynamic and kinetic data required for successful and rigorous design of reactive distillation esterification processes. Specifically, this project has led to the development of economical, technically viable processes for ethyl lactate, triethyl citrate and diethyl succinate production, and on a larger scale has added to the overall body of knowledge on applying fermentation based organic acids as platform chemicals in the emerging biorefinery. Organic acid esters constitute an attractive class of biorenewable chemicals that are made from corn or other renewable biomass carbohydrate feedstocks and replace analogous petroleum-based compounds, thus lessening U.S. dependence on foreign petroleum and enhancing overall biorefinery viability through production of value-added chemicals in parallel with biofuels production. Further, many of these ester products are candidates for fuel (particularly biodiesel) components, and thus will serve dual roles as both industrial chemicals and fuel enhancers in the emerging bioeconomy. The technical report from MSU is organized around the ethyl esters of four important biorenewables-based acids: lactic acid, citric acid, succinic acid, and propionic acid. Literature background on esterification and reactive distillation has been provided in Section One. Work on lactic acid is covered in Sections Two through Five, citric acid esterification in Sections Six and Seven, succinic acid in Section Eight, and propionic acid in Section Nine. Section Ten covers modeling of ester and organic acid vapor pressure properties using the SPEAD (Step Potential

  15. Accounting Curriculum.

    ERIC Educational Resources Information Center

    Prickett, Charlotte

    This curriculum guide describes the accounting curriculum in the following three areas: accounting clerk, bookkeeper, and nondegreed accountant. The competencies and tasks complement the Arizona validated listing in these areas. The guide lists 24 competencies for nondegreed accountants, 10 competencies for accounting clerks, and 11 competencies…

  16. Development of prototype induced-fission-based Pu accountancy instrument for safeguards applications.

    PubMed

    Seo, Hee; Lee, Seung Kyu; An, Su Jung; Park, Se-Hwan; Ku, Jeong-Hoe; Menlove, Howard O; Rael, Carlos D; LaFleur, Adrienne M; Browne, Michael C

    2016-09-01

    Prototype safeguards instrument for nuclear material accountancy (NMA) of uranium/transuranic (U/TRU) products that could be produced in a future advanced PWR fuel processing facility has been developed and characterized. This is a new, hybrid neutron measurement system based on fast neutron energy multiplication (FNEM) and passive neutron albedo reactivity (PNAR) methods. The FNEM method is sensitive to the induced fission rate by fast neutrons, while the PNAR method is sensitive to the induced fission rate by thermal neutrons in the sample to be measured. The induced fission rate is proportional to the total amount of fissile material, especially plutonium (Pu), in the U/TRU product; hence, the Pu amount can be calibrated as a function of the induced fission rate, which can be measured using either the FNEM or PNAR method. In the present study, the prototype system was built using six (3)He tubes, and its performance was evaluated for various detector parameters including high-voltage (HV) plateau, efficiency profiles, dead time, and stability. The system's capability to measure the difference in the average neutron energy for the FNEM signature also was evaluated, using AmLi, PuBe, (252)Cf, as well as four Pu-oxide sources each with a different impurity (Al, F, Mg, and B) and producing (α,n) neutrons with different average energies. Future work will measure the hybrid signature (i.e., FNEM×PNAR) for a Pu source with an external interrogating neutron source after enlarging the cavity size of the prototype system to accommodate a large-size Pu source (~600g Pu).

  17. Appearance questions can be misleading: a discourse-based account of the appearance-reality problem.

    PubMed

    Hansen, Mikkel B; Markman, Ellen M

    2005-05-01

    Preschoolers' success on the appearance-reality task is a milestone in theory-of-mind development. On the standard task children see a deceptive object, such as a sponge that looks like a rock, and are asked, "What is this really?" and "What does this look like?" Children below 412 years of age fail saying that the object not only is a sponge but also looks like a sponge. We propose that young children's difficulty stems from ambiguity in the meaning of "looks like." This locution can refer to outward appearance ("Peter looks like Paul") but in fact often refers to likely reality ("That looks like Jim"). We propose that "looks like" is taken to refer to likely reality unless the reality is already part of the common ground of the conversation. Because this joint knowledge is unclear to young children on the appearance-reality task, they mistakenly think the appearance question is about likely reality. Study 1 analyzed everyday conversations from the CHILDES database and documented that 2 and 3-year-olds are familiar with these two different uses of the locution. To disambiguate the meaning of "looks like," Study 2 clarified that reality was shared knowledge as part of the appearance question, e.g., "What does the sponge look like?" Study 3 used a non-linguistic measure to emphasize the shared knowledge of the reality in the appearance question. Study 4 asked children on their own to articulate the contrast between appearance and reality. At 91%, 85%, and 81% correct responses, children were at near ceiling levels in each of our manipulations while they failed the standard versions of the tasks. Moreover, we show how this discourse-based explanation accounts for findings in the literature. Thus children master the appearance-reality distinction by the age of 3 but the standard task masks this understanding because of the discourse structure involved in talking about appearances.

  18. Polymerization of amino acids containing nucleotide bases

    NASA Technical Reports Server (NTRS)

    Ben Cheikh, Azzouz; Orgel, Leslie E.

    1990-01-01

    The nucleoamino acids 1-(3'-amino,3'-carboxypropyl)uracil (3) and 9-(3'-amino,3'-carboxypropyl)adenine (4) have been prepared as (L)-en-antiomers and as racemic mixtures. When 3 or 4 is suspended in water and treated with N,N'-carbon-yldiimidazole, peptides are formed in good yield. The products formed from the (L)-enantiomers are hydrolyzed to the monomeric amino acids by pronase. Attempts to improve the efficiency of these oligomerizations by including a polyuridylate template in the reaction mixture were not successful. Similarly, oligomers derived from the (L)-enantiomer of 3 did not act as templates to facilitate the oligomerization of 4.

  19. Carbon-based strong solid acid for cornstarch hydrolysis

    SciTech Connect

    Nata, Iryanti Fatyasari; Irawan, Chairul; Mardina, Primata; Lee, Cheng-Kang

    2015-10-15

    Highly sulfonated carbonaceous spheres with diameter of 100–500 nm can be generated by hydrothermal carbonization of glucose in the presence of hydroxyethylsulfonic acid and acrylic acid at 180 °C for 4 h. The acidity of the prepared carbonaceous sphere C4-SO{sub 3}H can reach 2.10 mmol/g. It was used as a solid acid catalyst for the hydrolysis of cornstarch. Total reducing sugar (TRS) concentration of 19.91 mg/mL could be obtained by hydrolyzing 20 mg/mL cornstarch at 150 °C for 6 h using C4-SO{sub 3}H as solid acid catalyst. The solid acid catalyst demonstrated good stability that only 9% decrease in TRS concentration was observed after five repeat uses. The as-prepared carbon-based solid acid catalyst can be an environmentally benign replacement for homogeneous catalyst. - Highlights: • Carbon solid acid was successfully prepared by one-step hydrothermal carbonization. • The acrylic acid as monomer was effectively reduce the diameter size of particle. • The solid acid catalyst show good catalytic performance of starch hydrolysis. • The solid acid catalyst is not significantly deteriorated after repeated use.

  20. Acid-base properties of adhesive dental polymers.

    PubMed

    Morra, M

    1993-11-01

    The surface energetics of three resins (polymethylmethacrylate, polyhydroxyethylmethacrylate, and Bis-GMA/triethyleneglycoldimethacrylate) commonly used in adhesive interactions with tooth hard tissues were evaluated according to the Fowkes acid-base theory of interfacial interactions. From the measurement of the contact angle of test acidic and basic liquids on the sample surfaces, the acid-base contribution to the work of adhesion was evaluated. Results show that polyhydroxyethylmethacrylate is a comparatively strong Lewis base, a finding that can explain the important role played by this material in the formulation of dentin adhesive.

  1. Differential titration of bases in glacial acetic acid.

    PubMed

    Castellano, T; Medwick, T; Shinkai, J H; Bailey, L

    1981-01-01

    A study of bases in acetic acid and their differential titration was carried out. The overall basicity constants for 20 bases were measured in acetic acid, and the differential titration of five binary mixtures of variable delta pKb values in acetic acid was followed using a glass electrode-modified calomel electrode system. Agreement with literature values was good. A leveling diagram was constructed that indicated that bases stronger than aqueous pKb 10 are leveled to an acetous pKb 5.69, whereas weaker bases are not leveled but instead exhibit their own intrinsic basicity, with the acetous pKb to aqueous pKb values being linearly related (slope 1.18, correlation coefficient 0.962). A minimum acetous delta pKb of four units is required for the satisfactory differential titration of two bases in acetic acid.

  2. Toward a Culture of Consequences: Performance-Based Accountability Systems for Public Services.

    PubMed

    Stecher, Brian M; Camm, Frank; Damberg, Cheryl L; Hamilton, Laura S; Mullen, Kathleen J; Nelson, Christopher; Sorensen, Paul; Wachs, Martin; Yoh, Allison; Zellman, Gail L; Leuschner, Kristin J; Camm, Frank; Stecher, Brian M

    2012-01-01

    Performance-based accountability systems (PBASs), which link incentives to measured performance as a means of improving services to the public, have gained popularity. While PBASs can vary widely across sectors, they share three main components: goals, incentives, and measures. Research suggests that PBASs influence provider behaviors, but little is known about PBAS effectiveness at achieving performance goals or about government and agency experiences. This study examines nine PBASs that are drawn from five sectors: child care, education, health care, public health emergency preparedness, and transportation. In the right circumstances, a PBAS can be an effective strategy for improving service delivery. Optimum circumstances include having a widely shared goal, unambiguous observable measures, meaningful incentives for those with control over the relevant inputs and processes, few competing interests, and adequate resources to design, implement, and operate the PBAS. However, these conditions are rarely fully realized, so it is difficult to design and implement PBASs that are uniformly effective. PBASs represent a promising policy option for improving the quality of service-delivery activities in many contexts. The evidence supports continued experimentation with and adoption of this approach in appropriate circumstances. Even so, PBAS design and its prospects for success depend on the context in which it will operate. Also, ongoing system evaluation and monitoring are integral components of a PBAS; they inform refinements that improve system functioning over time. Empirical evidence of the effects of performance-based public management is scarce. This article also describes a framework used to evaluate a PBAS. Such a system identifies individuals or organizations that must change their behavior for the performance of an activity to improve, chooses an implicit or explicit incentive structure to motivate these organizations or individuals to change, and then

  3. A performance weighting procedure for GCMs based on explicit probabilistic models and accounting for observation uncertainty

    NASA Astrophysics Data System (ADS)

    Renard, Benjamin; Vidal, Jean-Philippe

    2016-04-01

    In recent years, the climate modeling community has put a lot of effort into releasing the outputs of multimodel experiments for use by the wider scientific community. In such experiments, several structurally distinct GCMs are run using the same observed forcings (for the historical period) or the same projected forcings (for the future period). In addition, several members are produced for a single given model structure, by running each GCM with slightly different initial conditions. This multiplicity of GCM outputs offers many opportunities in terms of uncertainty quantification or GCM comparisons. In this presentation, we propose a new procedure to weight GCMs according to their ability to reproduce the observed climate. Such weights can be used to combine the outputs of several models in a way that rewards good-performing models and discards poorly-performing ones. The proposed procedure has the following main properties: 1. It is based on explicit probabilistic models describing the time series produced by the GCMs and the corresponding historical observations, 2. It can use several members whenever available, 3. It accounts for the uncertainty in observations, 4. It assigns a weight to each GCM (all weights summing up to one), 5. It can also assign a weight to the "H0 hypothesis" that all GCMs in the multimodel ensemble are not compatible with observations. The application of the weighting procedure is illustrated with several case studies including synthetic experiments, simple cases where the target GCM output is a simple univariate variable and more realistic cases where the target GCM output is a multivariate and/or a spatial variable. These case studies illustrate the generality of the procedure which can be applied in a wide range of situations, as long as the analyst is prepared to make an explicit probabilistic assumption on the target variable. Moreover, these case studies highlight several interesting properties of the weighting procedure. In

  4. Nucleic acid based fluorescent sensor for mercury detection

    DOEpatents

    Lu, Yi; Liu, Juewen

    2013-02-05

    A nucleic acid enzyme comprises an oligonucleotide containing thymine bases. The nucleic acid enzyme is dependent on both Hg.sup.2+and a second ion as cofactors, to produce a product from a substrate. The substrate comprises a ribonucleotide, a deoxyribonucleotide, or both.

  5. Identification of Amino Acids that Account for Long-Range Interactions in Two Triosephosphate Isomerases from Pathogenic Trypanosomes

    SciTech Connect

    García-Torres, Itzhel; Cabrera, Nallely; Torres-Larios, Alfredo; Rodríguez-Bolaños, Mónica; Díaz-Mazariegos, Selma; Gómez-Puyou, Armando; Perez-Montfort, Ruy

    2012-04-02

    For a better comprehension of the structure-function relationship in proteins it is necessary to identify the amino acids that are relevant for measurable protein functions. Because of the numerous contacts that amino acids establish within proteins and the cooperative nature of their interactions, it is difficult to achieve this goal. Thus, the study of protein-ligand interactions is usually focused on local environmental structural differences. Here, using a pair of triosephosphate isomerase enzymes with extremely high homology from two different organisms, we demonstrate that the control of a seventy-fold difference in reactivity of the interface cysteine is located in several amino acids from two structurally unrelated regions that do not contact the cysteine sensitive to the sulfhydryl reagent methylmethane sulfonate, nor the residues in its immediate vicinity. The change in reactivity is due to an increase in the apparent pKa of the interface cysteine produced by the mutated residues. Our work, which involved grafting systematically portions of one protein into the other protein, revealed unsuspected and multisite long-range interactions that modulate the properties of the interface cysteines and has general implications for future studies on protein structure-function relationships.

  6. Boronic acid-tethered amphiphilic hyaluronic acid derivative-based nanoassemblies for tumor targeting and penetration.

    PubMed

    Jeong, Jae Young; Hong, Eun-Hye; Lee, Song Yi; Lee, Jae-Young; Song, Jae-Hyoung; Ko, Seung-Hak; Shim, Jae-Seong; Choe, Sunghwa; Kim, Dae-Duk; Ko, Hyun-Jeong; Cho, Hyun-Jong

    2017-02-16

    (3-Aminomethylphenyl)boronic acid (AMPB)-installed hyaluronic acid-ceramide (HACE)-based nanoparticles (NPs), including manassantin B (MB), were fabricated for tumor-targeted delivery. The amine group of AMPB was conjugated to the carboxylic acid group of hyaluronic acid (HA) via amide bond formation, and synthesis was confirmed by spectroscopic methods. HACE-AMPB/MB NPs with a 239-nm mean diameter, narrow size distribution, negative zeta potential, and >90% drug encapsulation efficiency were fabricated. Exposed AMPB in the outer surface of HACE-AMPB NPs (in the aqueous environment) may react with sialic acid of cancer cells. The improved cellular accumulation efficiency, in vitro antitumor efficacy, and tumor penetration efficiency of HACE-AMPB/MB NPs, compared with HACE/MB NPs, in MDA-MB-231 cells (CD44 receptor-positive human breast adenocarcinoma cells) may be based on the CD44 receptor-mediated endocytosis and phenylboronic acid-sialic acid interaction. Enhanced in vivo tumor targetability, infiltration efficiency, and antitumor efficacies of HACE-AMPB NPs, compared with HACE NPs, were observed in a MDA-MB-231 tumor-xenografted mouse model. In addition to passive tumor targeting (based on an enhanced permeability and retention effect) and active tumor targeting (interaction between HA and CD44 receptor), the phenylboronic acid-sialic acid interaction can play important roles in augmented tumor targeting and penetration of HACE-AMPB NPs. STATEMENT OF SIGNIFICANCE: (3-Aminomethylphenyl)boronic acid (AMPB)-tethered hyaluronic acid-ceramide (HACE)-based nanoparticles (NPs), including manassantin B (MB), were fabricated and their tumor targeting and penetration efficiencies were assessed in MDA-MB-231 (CD44 receptor-positive human adenocarcinoma) tumor models. MB, which exhibited antitumor efficacies via the inhibition of angiogenesis and hypoxia inducible factor (HIF)-1, was entrapped in HACE-AMPB NPs in this study. Phenylboronic acid located in the outer surface

  7. Acid-base titration curves for acids with very small ratios of successive dissociation constants.

    PubMed

    Campbell, B H; Meites, L

    1974-02-01

    The shapes of the potentiometric acid-base titration curves obtained in the neutralizations of polyfunctional acids or bases for which each successive dissociation constant is smaller than the following one are examined. In the region 0 < < 1 (where is the fraction of the equivalent volume of reagent that has been added) the slope of the titration curve decreases as the number j of acidic or basic sites increases. The difference between the pH-values at = 0.75 and = 0.25 has (1 j)log 9 as the lower limit of its maximum value.

  8. Renal acidification responses to respiratory acid-base disorders.

    PubMed

    Madias, Nicolaos E

    2010-01-01

    Respiratory acid-base disorders are those abnormalities in acid-base equilibrium that are expressed as primary changes in the arterial carbon dioxide tension (PaCO2). An increase in PaCO2 (hypercapnia) acidifies body fluids and initiates the acid-base disturbance known as respiratory acidosis. By contrast, a decrease in PaCO2 (hypocapnia) alkalinizes body fluids and initiates the acid-base disturbance known as respiratory alkalosis. The impact on systemic acidity of these primary changes in PaCO2 is ameliorated by secondary, directional changes in plasma [HCO3¯] that occur in 2 stages. Acutely, hypercapnia or hypocapnia yields relatively small changes in plasma [HCO3¯] that originate virtually exclusively from titration of the body's nonbicarbonate buffers. During sustained hypercapnia or hypocapnia, much larger changes in plasma [HCO3¯] occur that reflect adjustments in renal acidification mechanisms. Consequently, the deviation of systemic acidity from normal is smaller in the chronic forms of these disorders. Here we provide an overview of the renal acidification responses to respiratory acid-base disorders. We also identify gaps in knowledge that require further research.

  9. An Olfactory Indicator for Acid-Base Titrations.

    ERIC Educational Resources Information Center

    Flair, Mark N.; Setzer, William N.

    1990-01-01

    The use of an olfactory acid-base indicator in titrations for visually impaired students is discussed. Potential olfactory indicators include eugenol, thymol, vanillin, and thiophenol. Titrations performed with each indicator with eugenol proved to be successful. (KR)

  10. The Impact of a Home-Based Palliative Care Program in an Accountable Care Organization

    PubMed Central

    Mudra, Mitchell; Romano, Carole; Lukoski, Ed; Chang, Andy; Mittelberger, James; Scherr, Terry; Cooper, David

    2017-01-01

    Abstract Background: People with advanced illness usually want their healthcare where they live—at home—not in the hospital. Innovative models of palliative care that better meet the needs of seriously ill people at lower cost should be explored. Objectives: We evaluated the impact of a home-based palliative care (HBPC) program implemented within an Accountable Care Organization (ACO) on cost and resource utilization. Methods: This was a retrospective analysis to quantify cost savings associated with a HBPC program in a Medicare Shared Savings Program ACO where total cost of care is available. We studied 651 decedents; 82 enrolled in a HBPC program compared to 569 receiving usual care in three New York counties who died between October 1, 2014, and March 31, 2016. We also compared hospital admissions, ER visits, and hospice utilization rates in the final months of life. Results: The cost per patient during the final three months of life was $12,000 lower with HBPC than with usual care ($20,420 vs. $32,420; p = 0.0002); largely driven by a 35% reduction in Medicare Part A ($16,892 vs. $26,171; p = 0.0037). HBPC also resulted in a 37% reduction in Medicare Part B in the final three months of life compared to usual care ($3,114 vs. $4,913; p = 0.0008). Hospital admissions were reduced by 34% in the final month of life for patients enrolled in HBPC. The number of admissions per 1000 beneficiaries per year was 3073 with HBPC and 4640 with usual care (p = 0.0221). HBPC resulted in a 35% increased hospice enrollment rate (p = 0.0005) and a 240% increased median hospice length of stay compared to usual care (34 days vs. 10 days; p < 0.0001). Conclusion: HBPC within an ACO was associated with significant cost savings, fewer hospitalizations, and increased hospice use in the final months of life. PMID:27574868

  11. Towards lactic acid bacteria-based biorefineries.

    PubMed

    Mazzoli, Roberto; Bosco, Francesca; Mizrahi, Itzhak; Bayer, Edward A; Pessione, Enrica

    2014-11-15

    Lactic acid bacteria (LAB) have long been used in industrial applications mainly as starters for food fermentation or as biocontrol agents or as probiotics. However, LAB possess several characteristics that render them among the most promising candidates for use in future biorefineries in converting plant-derived biomass-either from dedicated crops or from municipal/industrial solid wastes-into biofuels and high value-added products. Lactic acid, their main fermentation product, is an attractive building block extensively used by the chemical industry, owing to the potential for production of polylactides as biodegradable and biocompatible plastic alternative to polymers derived from petrochemicals. LA is but one of many high-value compounds which can be produced by LAB fermentation, which also include biofuels such as ethanol and butanol, biodegradable plastic polymers, exopolysaccharides, antimicrobial agents, health-promoting substances and nutraceuticals. Furthermore, several LAB strains have ascertained probiotic properties, and their biomass can be considered a high-value product. The present contribution aims to provide an extensive overview of the main industrial applications of LAB and future perspectives concerning their utilization in biorefineries. Strategies will be described in detail for developing LAB strains with broader substrate metabolic capacity for fermentation of cheaper biomass.

  12. Synthesis and antimicrobial activities of new higher amino acid Schiff base derivatives of 6-aminopenicillanic acid and 7-aminocephalosporanic acid

    NASA Astrophysics Data System (ADS)

    Özdemir (nee Güngör), Özlem; Gürkan, Perihan; Özçelik, Berrin; Oyardı, Özlem

    2016-02-01

    Novel β-lactam derivatives (1c-3c) (1d-3d) were produced by using 6-aminopenicillanic acid (6-APA), 7-aminocephalosporanic acid (7-ACA) and the higher amino acid Schiff bases. The synthesized compounds were characterized by elemental analysis, IR, 1H/13C NMR and UV-vis spectra. Antibacterial activities of all the higher amino acid Schiff bases (1a-3a) (1b-3b) and β-lactam derivatives were screened against three gram negative bacteria (Escherichia coli ATCC 25922, Pseudomonas aeruginosa ATCC 27853, Acinetobacter baumannii RSKK 02026), three gram positive bacteria (Staphylococcus aureus ATCC 25923, Enterococcus faecalis ATCC 07005, Bacillus subtilis ATCC 6633) and their drug-resistant isolates by using broth microdilution method. Two fungi (Candida albicans and Candida krusei) were used for antifungal activity.

  13. Volatility in School Test Scores: Implications for Test-Based Accountability Systems

    ERIC Educational Resources Information Center

    Kane, Thomas J.; Staiger, Douglas O.

    2002-01-01

    By the spring of 2000, forty states had begun using student test scores to rate school performance. Twenty states have gone a step further and are attaching explicit monetary rewards or sanctions to a school's test performance. In this paper, the authors focus on accountability programs in which states measure the effectiveness of individual…

  14. Adapting Educational Measurement to the Demands of Test-Based Accountability

    ERIC Educational Resources Information Center

    Koretz, Daniel

    2015-01-01

    Accountability has become a primary function of large-scale testing in the United States. The pressure on educators to raise scores is vastly greater than it was several decades ago. Research has shown that high-stakes testing can generate behavioral responses that inflate scores, often severely. I argue that because of these responses, using…

  15. Accounting for Teamwork: A Critical Study of Group-Based Systems of Organizational Control.

    ERIC Educational Resources Information Center

    Ezzamel, Mahmoud; Willmott, Hugh

    1998-01-01

    Examines the role of accounting calculations in reorganizing manufacturing capabilities of a vertically integrated global retailing company. Introducing teamwork to replace line work extended traditional, hierarchical management control systems. Teamwork's self-managing demands contravened workers' established sense of self-identity as…

  16. Performance-Based Incentives and the Behavior of Accounting Academics: Responding to Changes

    ERIC Educational Resources Information Center

    Moya, Soledad; Prior, Diego; Rodríguez-Pérez, Gonzalo

    2015-01-01

    When laws change the rules of the game, it is important to observe the effects on the players' behavior. Some effects can be anticipated while others are difficult to enunciate before the law comes into force. In this paper we have analyzed articles authored by Spanish accounting academics between 1996 and 2005 to assess the impact of a change in…

  17. Hamlet without the Prince: Shortcomings of an Activity-Based Account of Joint Attention

    ERIC Educational Resources Information Center

    Hobson, R. Peter

    2007-01-01

    In this commentary, I consider several strengths of the position adopted by Racine and Carpendale (2007), but suggest that the authors are in danger of overstating their case. In doing so, they appear to sideline an issue that should be pivotal for accounts of joint attention: how does a child come to arrive at an understanding that people, both…

  18. School-Based Accountability and the Distribution of Teacher Quality across Grades in Elementary School

    ERIC Educational Resources Information Center

    Fuller, Sarah C.; Ladd, Helen F.

    2013-01-01

    We use North Carolina data to explore whether the quality of teachers in the lower elementary grades (K-2) falls short of teacher quality in the upper grades (3-5) and to examine the hypothesis that school accountability pressures contribute to such quality shortfalls. Our concern with the early grades arises from recent studies highlighting how…

  19. Teachers' Perceptions of the Impact of Performance-Based Accountability on Teacher Efficacy

    ERIC Educational Resources Information Center

    Gantt, Phyllis Elizabeth Crowley

    2012-01-01

    Implementation of state and federal high-stakes accountability measures such as end-of-course tests (EoCTs) has contributed to increased teacher stress in the classroom, decreased teacher creativity and autonomy, and reduced effectiveness. Prior research focused primarily on the elementary and middle school levels, so this study sought to examine…

  20. Synthesis of polyacrylic-acid-based thermochromic polymers

    NASA Astrophysics Data System (ADS)

    Srivastava, Jyoti; Alam, Sarfaraz; Mathur, G. N.

    2003-10-01

    Smart materials respond to environmental stimuli with particular changes in some variables (for example temperature, pressure and electric field etc), for that reason they are often called responsive materials. In the present work, we have synthesized thermochromic polymer based on poly acrylic acid cobalt chloride (CoCl2) and phosphoric acid (H3PO4) that visually and reversibly changes color in the temperature range (70 - 130°C). These thermochromic materials can be used as visual sensors of temperature. Thermochromic polymers are based on polyacrylic acid and CoCl2 complex.

  1. Acid Base Titrations in Nonaqueous Solvents and Solvent Mixtures

    NASA Astrophysics Data System (ADS)

    Barcza, Lajos; Buvári-Barcza, Ágnes

    2003-07-01

    The acid base determination of different substances by nonaqueous titrations is highly preferred in pharmaceutical analyses since the method is quantitative, exact, and reproducible. The modern interpretation of the reactions in nonaqueous solvents started in the last century, but several inconsistencies and unsolved problems can be found in the literature. The acid base theories of Brønsted Lowry and Lewis as well as the so-called solvent theory are outlined first, then the promoting (and leveling) and the differentiating effects are discussed on the basis of the hydrogen-bond concept. Emphasis is put on the properties of formic acid and acetic anhydride since their importance is increasing.

  2. Acid-base transport in pancreatic cancer: molecular mechanisms and clinical potential.

    PubMed

    Kong, Su Chii; Giannuzzo, Andrea; Gianuzzo, Andrea; Novak, Ivana; Pedersen, Stine Falsig

    2014-12-01

    Solid tumors are characterized by a microenvironment that is highly acidic, while intracellular pH (pHi) is normal or even elevated. This is the result of elevated metabolic rates in the highly proliferative cancer cells, in conjunction with often greatly increased rates of net cellular acid extrusion. Studies in various cancers have suggested that while the acid extrusion mechanisms employed are generally the same as those in healthy cells, the specific transporters upregulated vary with the cancer type. The main such transporters include Na(+)/H(+) exchangers, various HCO3(-) transporters, H(+) pumps, and lactate-H(+) cotransporters. The mechanisms leading to their dysregulation in cancer are incompletely understood but include changes in transporter expression levels, trafficking and membrane localization, and posttranslational modifications. In turn, accumulating evidence has revealed that in addition to supporting their elevated metabolic rate, their increased acid efflux capacity endows the cancer cells with increased capacity for invasiveness, proliferation, and chemotherapy resistance. The pancreatic duct exhibits an enormous capacity for acid-base transport, rendering pHi dysregulation a potentially very important topic in pancreatic ductal adenocarcinoma (PDAC). PDAC - accounting for about 90% of all pancreatic cancers - has one of the highest cancer mortality rates known, and new diagnostic and treatment options are highly needed. However, very little is known about whether pH regulation is altered in PDAC and, if so, the possible role of this in cancer development. Here, we review current models for pancreatic acid-base transport and pH homeostasis and summarize current views on acid-base dysregulation in cancer, focusing where possible on the few studies to date in PDAC. Finally, we present new data-mining analyses of acid-base transporter expression changes in PDAC and discuss essential directions for future work.

  3. Standards-Based Accountability under No Child Left Behind: Experiences of Teachers and Administrators in Three States. MG-589-NSF

    ERIC Educational Resources Information Center

    Hamilton, Laura S.; Stecher, Brian M.; Marsh, Julie A.; McCombs, Jennifer Sloan; Robyn, Abby; Russell, Jennifer; Naftel, Scott; Barney, Heather

    2007-01-01

    Since 2001-2002, standards-based accountability (SBA) provisions of the No Child Left Behind Act of 2001 (NCLB) have shaped the work of public school teachers and administrators in the United States. NCLB requires each state to develop content and achievement standards in several subjects, administer tests to measure students' progress toward…

  4. An Empirical Research of Chinese Learners' Acquisition of the English Article System--Based on Syntactic Misanalysis Account

    ERIC Educational Resources Information Center

    Jian, Shi

    2013-01-01

    In the field of applied linguistics, the English article is the acknowledged teaching and learning difficulty and receives lots of attention in second language acquisition (SLA). This paper, based on the Syntactic Misanalysis Account (SMA) advocated by Trenkic in which L2 articles are analyzed as adjectives by L2ers, proposes the English article…

  5. The Effects of Project Based Learning on 21st Century Skills and No Child Left Behind Accountability Standards

    ERIC Educational Resources Information Center

    Holmes, Lisa Marie

    2012-01-01

    The purpose of this study was to determine ways "Digital Biographies," a Project Based Learning Unit, developed 21st century skills while simultaneously supporting NCLB accountability standards. The main goal of this study was to inform professional practice by exploring ways to address two separate, seemingly opposing, demands of…

  6. Distorting Value Added: The Use of Longitudinal, Vertically Scaled Student Achievement Data for Growth-Based, Value-Added Accountability

    ERIC Educational Resources Information Center

    Martineau, Joseph A.

    2006-01-01

    Longitudinal, student performance-based, value-added accountability models have become popular of late and continue to enjoy increasing popularity. Such models require student data to be vertically scaled across wide grade and developmental ranges so that the value added to student growth/achievement by teachers, schools, and districts may be…

  7. Starworld: Preparing Accountants for the Future: A Case-Based Approach to Teach International Financial Reporting Standards Using ERP Software

    ERIC Educational Resources Information Center

    Ragan, Joseph M.; Savino, Christopher J.; Parashac, Paul; Hosler, Jonathan C.

    2010-01-01

    International Financial Reporting Standards now constitute an important part of educating young professional accountants. This paper looks at a case based process to teach International Financial Reporting Standards using integrated Enterprise Resource Planning software. The case contained within the paper can be used within a variety of courses…

  8. An Acid-Base Chemistry Example: Conversion of Nicotine

    NASA Astrophysics Data System (ADS)

    Summerfield, John H.

    1999-10-01

    The current government interest in nicotine conversion by cigarette companies provides an example of acid-base chemistry that can be explained to students in the second semester of general chemistry. In particular, the conversion by ammonia of the +1 form of nicotine to the easier-to-assimilate free-base form illustrates the effect of pH on acid-base equilibrium. The part played by ammonia in tobacco smoke is analogous to what takes place when cocaine is "free-based".

  9. HF acid blends based on formation conditions eliminate precipitation problems

    SciTech Connect

    Gdanski, R.; Shuchart, C.

    1997-03-01

    Formulating HCl-HF acid blends based on the mineralogy and temperature of a formation can increase the success of hydrofluoric acid (HF) treatments. Sodium and potassium in the structures of formation minerals can cause precipitation and matrix plugging problems during acidizing. Slight modifications of the acid blend used in the treatment can help eliminate fluosilicate precipitation. Researchers recently conducted tests to determine how acid blends react in different formations under varying temperatures. The results of the tests indicate that the minimum HCl:HF ratio in an acid blend is 6-to-1, and the optimum ratio is 9-to-1. Regular mud acid (12% HCl-3% HF) has been used successfully for years to enhance production in sandstone formations. By the 1980s, operators began to vary the concentration of HF and HCl acids to solve excessive sanding problems in sandstone. The paper discusses treatment problems, formation characteristics, alumino-silicate scaling, research results, brine compatibility, optimum treatment, and acid volume guidelines.

  10. Acid/base properties and phenylphosphonic acid complexation at the aged {gamma}-Al{sub 2}O{sub 3}/water interface

    SciTech Connect

    Laiti, E.; Oehman, L.O.; Nordin, J.; Sjoeberg, S.

    1995-10-01

    Acid/base properties and phenylphosphonic acid (H{sub 2}L) complexation at the water-suspended-and-aged {gamma}-Al{sub 2}O{sub 3}/water interface have been studied in 0.1 M Na(Cl) medium at 25.0C in the range 5.0 < {minus}log[H{sup +}] < 9.5. Equilibrium measurements were performed as a series of potentiometric titrations supplemented with spectrophotometric phosphorus analyses. In the evaluation of the experimental data, the contribution from electrostatic forces was accounted for by using the constant-capacitance model. The adsorption of phenylphosphonic acid onto the studied phase was found to be strong at {minus}log[H{sup +}] < 7. Desorption was observed when {minus}log[H{sup +}] was increased toward 9.5. The specific capacitance was evaluated from data collected in the absence of phenylphosphonic acid. The model describing the acid/base reactions and phenylphosphonic acid binding onto the studied alumina surface is given in the paper. In a series of modeling calculations, the complexation features of phenylphosphonic acid are compared to those of orthophosphoric acid.

  11. Generation of SEEAW asset accounts based on water resources management models

    NASA Astrophysics Data System (ADS)

    Pedro-Monzonís, María; Solera, Abel; Andreu, Joaquín

    2015-04-01

    One of the main challenges in the XXI century is related with the sustainable use of water. This is due to the fact that water is an essential element for the life of all who inhabit our planet. In many cases, the lack of economic valuation of water resources causes an inefficient water use. In this regard, society expects of policymakers and stakeholders maximise the profit produced per unit of natural resources. Water planning and the Integrated Water Resources Management (IWRM) represent the best way to achieve this goal. The System of Environmental-Economic Accounting for Water (SEEAW) is displayed as a tool for water allocation which enables the building of water balances in a river basin. The main concern of the SEEAW is to provide a standard approach which allows the policymakers to compare results between different territories. But building water accounts is a complex task due to the difficulty of the collection of the required data. Due to the difficulty of gauging the components of the hydrological cycle, the use of simulation models has become an essential tool extensively employed in last decades. The target of this paper is to present the building up of a database that enables the combined use of hydrological models and water resources models developed with AQUATOOL DSSS to fill in the SEEAW tables. This research is framed within the Water Accounting in a Multi-Catchment District (WAMCD) project, financed by the European Union. Its main goal is the development of water accounts in the Mediterranean Andalusian River Basin District, in Spain. This research pretends to contribute to the objectives of the "Blueprint to safeguard Europe's water resources". It is noteworthy that, in Spain, a large part of these methodological decisions are included in the Spanish Guideline of Water Planning with normative status guaranteeing consistency and comparability of the results.

  12. A dynamic water accounting framework based on marginal resource opportunity cost

    NASA Astrophysics Data System (ADS)

    Tilmant, A.; Marques, G.; Mohamed, Y.

    2014-10-01

    Many river basins throughout the world are increasingly under pressure as water demands keep rising due to population growth, industrialization, urbanization and rising living standards. In the past, the typical answer to meet those demands focused on the supply-side and involved the construction of hydraulic infrastructures to capture more water from surface water bodies and from aquifers. As river basins were being more and more developed, downstream water users and ecosystems have become increasingly dependent on the management actions taken by upstream users. The increased interconnectedness between water users, aquatic ecosystems and the built environment is further compounded by climate change and its impact on the water cycle. Those pressures mean that it has become increasingly important to measure and account for changes in water fluxes and their corresponding economic value as they progress throughout the river system. Such basin water accounting should provide policy makers with important information regarding the relative contribution of each water user, infrastructure and management decision to the overall economic value of the river basin. This paper presents a dynamic water accounting approach whereby the entire river basin is considered as a value chain with multiple services including production and storage. Water users and reservoirs operators are considered as economic agents who can exchange water with their hydraulic neighbours at a price corresponding to the marginal value of water. Effective water accounting is made possible by keeping track of all water fluxes and their corresponding hypothetical transactions using the results of a hydro-economic model. The proposed approach is illustrated with the Eastern Nile River basin in Africa.

  13. A dynamic water accounting framework based on marginal resource opportunity cost

    NASA Astrophysics Data System (ADS)

    Tilmant, A.; Marques, G.; Mohamed, Y.

    2015-03-01

    Many river basins throughout the world are increasingly under pressure as water demands keep rising due to population growth, industrialization, urbanization and rising living standards. In the past, the typical answer to meet those demands focused on the supply side and involved the construction of hydraulic infrastructures to capture more water from surface water bodies and from aquifers. As river basins have become more and more developed, downstream water users and ecosystems have become increasingly dependent on the management actions taken by upstream users. The increased interconnectedness between water users, aquatic ecosystems and the built environment is further compounded by climate change and its impact on the water cycle. Those pressures mean that it has become increasingly important to measure and account for changes in water fluxes and their corresponding economic value as they progress throughout the river system. Such basin water accounting should provide policy makers with important information regarding the relative contribution of each water user, infrastructure and management decision to the overall economic value of the river basin. This paper presents a dynamic water accounting approach whereby the entire river basin is considered as a value chain with multiple services including production and storage. Water users and reservoir operators are considered as economic agents who can exchange water with their hydraulic neighbors at a price corresponding to the marginal value of water. Effective water accounting is made possible by keeping track of all water fluxes and their corresponding hypothetical transactions using the results of a hydro-economic model. The proposed approach is illustrated with the Eastern Nile River basin in Africa.

  14. Cost unit accounting based on a clinical pathway: a practical tool for DRG implementation.

    PubMed

    Feyrer, R; Rösch, J; Weyand, M; Kunzmann, U

    2005-10-01

    Setting up a reliable cost unit accounting system in a hospital is a fundamental necessity for economic survival, given the current general conditions in the healthcare system. Definition of a suitable cost unit is a crucial factor for success. We present here the development and use of a clinical pathway as a cost unit as an alternative to the DRG. Elective coronary artery bypass grafting was selected as an example. Development of the clinical pathway was conducted according to a modular concept that mirrored all the treatment processes across various levels and modules. Using service records and analyses the process algorithms of the clinical pathway were developed and visualized with CorelTM iGrafix Process 2003. A detailed process cost record constituted the basis of the pathway costing, in which financial evaluation of the treatment processes was performed. The result of this study was a structured clinical pathway for coronary artery bypass grafting together with a cost calculation in the form of cost unit accounting. The use of a clinical pathway as a cost unit offers considerable advantages compared to the DRG or clinical case. The variance in the diagnoses and procedures within a pathway is minimal, so the consumption of resources is homogeneous. This leads to a considerable improvement in the value of cost unit accounting as a strategic control instrument in hospitals.

  15. Effect of temperature on acid-base equilibria in separation techniques. A review.

    PubMed

    Gagliardi, Leonardo G; Tascon, Marcos; Castells, Cecilia B

    2015-08-19

    Studies on the theoretical principles of acid-base equilibria are reviewed and the influence of temperature on secondary chemical equilibria within the context of separation techniques, in water and also in aqueous-organic solvent mixtures, is discussed. In order to define the relationships between the retention in liquid chromatography or the migration velocity in capillary electrophoresis and temperature, the main properties of acid-base equilibria have to be taken into account for both, the analytes and the conjugate pairs chosen to control the solution pH. The focus of this review is based on liquid-liquid extraction (LLE), liquid chromatography (LC) and capillary electrophoresis (CE), with emphasis on the use of temperature as a useful variable to modify selectivity on a predictable basis. Simplified models were evaluated to achieve practical optimizations involving pH and temperature (in LLE and CE) as well as solvent composition in reversed-phase LC.

  16. CLAIM (CLinical Accounting InforMation)--an XML-based data exchange standard for connecting electronic medical record systems to patient accounting systems.

    PubMed

    Guo, Jinqiu; Takada, Akira; Tanaka, Koji; Sato, Junzo; Suzuki, Muneou; Takahashi, Kiwamu; Daimon, Hiroyuki; Suzuki, Toshiaki; Nakashima, Yusei; Araki, Kenji; Yoshihara, Hiroyuki

    2005-08-01

    With the evolving and diverse electronic medical record (EMR) systems, there appears to be an ever greater need to link EMR systems and patient accounting systems with a standardized data exchange format. To this end, the CLinical Accounting InforMation (CLAIM) data exchange standard was developed. CLAIM is subordinate to the Medical Markup Language (MML) standard, which allows the exchange of medical data among different medical institutions. CLAIM uses eXtensible Markup Language (XML) as a meta-language. The current version, 2.1, inherited the basic structure of MML 2.x and contains two modules including information related to registration, appointment, procedure and charging. CLAIM 2.1 was implemented successfully in Japan in 2001. Consequently, it was confirmed that CLAIM could be used as an effective data exchange format between EMR systems and patient accounting systems.

  17. Amino acid profile of milk-based infant formulas.

    PubMed

    Viadel, B; Alegriá, A; Farré, R; Abellán, P; Romero, F

    2000-09-01

    The protein content and amino acid profile of three milk-based infant formulas, two of which were powdered (adapted and follow-on) and the third liquid, were determined to check their compliance with the EU directive and to evaluate whether or not they fulfil an infant's nutritional needs. To obtain the amino acid profile proteins were subjected to acid hydrolysis, prior to which the sulfur-containing amino acids were oxidized with performic acid. The amino acids were derivatized with phenylisothiocyanate (PITC) and then determined by ion-pair reverse phase high performance liquid chromatography (HPLC) In the case of tryptophan a basic hydrolysis was applied and there was no need of derivatization. The protein contents of the analysed formulas were in the ranges established by the EU directive for these products and the amino acid contents were in the ranges reported by other authors for these types of formulas. In all cases the tryptophan content determined the value of the chemical score, which was always lower than 80% of the reference protein but in the ranges reported by other authors. The analysed adapted infant formula provides amino acids in amounts higher than the established nutritional requirements.

  18. Poly (ricinoleic acid) based novel thermosetting elastomer.

    PubMed

    Ebata, Hiroki; Yasuda, Mayumi; Toshima, Kazunobu; Matsumura, Shuichi

    2008-01-01

    A novel bio-based thermosetting elastomer was prepared by the lipase-catalyzed polymerization of methyl ricinoleate with subsequent vulcanization. Some mechanical properties of the cured carbon black-filled polyricinoleate compounds were evaluated as a thermosetting elastomer. It was found that the carbon black-filled polyricinoleate compounds were readily cured by sulfur curatives to produce a thermosetting elastomer that formed a rubber-like sheet with a smooth and non-sticky surface. The curing behaviors and mechanical properties were dependent on both the molecular weight of the polyricinoleate and the amount of the sulfur curatives. Cured compounds consisting of polyricinoleate with a molecular weight of 100,800 showed good mechanical properties, such as a hardness of 48 A based on the durometer A measurements, a tensile strength at break of 6.91 MPa and an elongation at break of 350%.

  19. Micellar acid-base potentiometric titrations of weak acidic and/or insoluble drugs.

    PubMed

    Gerakis, A M; Koupparis, M A; Efstathiou, C E

    1993-01-01

    The effect of various surfactants [the cationics cetyl trimethyl ammonium bromide (CTAB) and cetyl pyridinium chloride (CPC), the anionic sodium dodecyl sulphate (SDS), and the nonionic polysorbate 80 (Tween 80)] on the solubility and ionization constant of some sparingly soluble weak acids of pharmaceutical interest was studied. Benzoic acid (and its 3-methyl-, 3-nitro-, and 4-tert-butyl-derivatives), acetylsalicylic acid, naproxen and iopanoic acid were chosen as model examples. Precise and accurate acid-base titrations in micellar systems were made feasible using a microcomputer-controlled titrator. The response curve, response time and potential drift of the glass electrode in the micellar systems were examined. The cationics CTAB and CPC were found to increase considerably the ionization constant of the weak acids (delta pKa ranged from -0.21 to -3.57), while the anionic SDS showed negligible effect and the nonionic Tween 80 generally decreased the ionization constants. The solubility of the acids in aqueous micellar and acidified micellar solutions was studied spectrophotometrically and it was found increased in all cases. Acetylsalicylic acid, naproxen, benzoic acid and iopanoic acid could be easily determined in raw material and some of them in pharmaceutical preparations by direct titration in CTAB-micellar system instead of using the traditional non-aqueous or back titrimetry. Precisions of 0.3-4.3% RSD and good correlation with the official tedious methods were obtained. The interference study of some excipients showed that a preliminary test should be carried out before the assay of formulations.

  20. Soil Studies: Applying Acid-Base Chemistry to Environmental Analysis.

    ERIC Educational Resources Information Center

    West, Donna M.; Sterling, Donna R.

    2001-01-01

    Laboratory activities for chemistry students focus attention on the use of acid-base chemistry to examine environmental conditions. After using standard laboratory procedures to analyze soil and rainwater samples, students use web-based resources to interpret their findings. Uses CBL probes and graphing calculators to gather and analyze data and…

  1. High School Students' Concepts of Acids and Bases.

    ERIC Educational Resources Information Center

    Ross, Bertram H. B.

    An investigation of Ontario high school students' understanding of acids and bases with quantitative and qualitative methods revealed misconceptions. A concept map, based on the objectives of the Chemistry Curriculum Guideline, generated multiple-choice items and interview questions. The multiple-choice test was administered to 34 grade 12…

  2. Hard and soft acids and bases: atoms and atomic ions.

    PubMed

    Reed, James L

    2008-07-07

    The structural origin of hard-soft behavior in atomic acids and bases has been explored using a simple orbital model. The Pearson principle of hard and soft acids and bases has been taken to be the defining statement about hard-soft behavior and as a definition of chemical hardness. There are a number of conditions that are imposed on any candidate structure and associated property by the Pearson principle, which have been exploited. The Pearson principle itself has been used to generate a thermodynamically based scale of relative hardness and softness for acids and bases (operational chemical hardness), and a modified Slater model has been used to discern the electronic origin of hard-soft behavior. Whereas chemical hardness is a chemical property of an acid or base and the operational chemical hardness is an experimental measure of it, the absolute hardness is a physical property of an atom or molecule. A critical examination of chemical hardness, which has been based on a more rigorous application of the Pearson principle and the availability of quantitative measures of chemical hardness, suggests that the origin of hard-soft behavior for both acids and bases resides in the relaxation of the electrons not undergoing transfer during the acid-base interaction. Furthermore, the results suggest that the absolute hardness should not be taken as synonymous with chemical hardness but that the relationship is somewhat more complex. Finally, this work provides additional groundwork for a better understanding of chemical hardness that will inform the understanding of hardness in molecules.

  3. Randomly Accountable

    ERIC Educational Resources Information Center

    Kane, Thomas J.; Staiger, Douglas O.; Geppert, Jeffrey

    2002-01-01

    The accountability debate tends to devolve into a battle between the pro-testing and anti-testing crowds. When it comes to the design of a school accountability system, the devil is truly in the details. A well-designed accountability plan may go a long way toward giving school personnel the kinds of signals they need to improve performance.…

  4. Reversible Hydrogenation of Carbon Dioxide to Formic Acid and Methanol: Lewis Acid Enhancement of Base Metal Catalysts.

    PubMed

    Bernskoetter, Wesley H; Hazari, Nilay

    2017-03-17

    New and sustainable energy vectors are required as a consequence of the environmental issues associated with the continued use of fossil fuels. H2 is a potential clean energy source, but as a result of problems associated with its storage and transport as a gas, chemical H2 storage (CHS), which involves the dehydrogenation of small molecules, is an attractive alternative. In principle, formic acid (FA, 4.4 wt % H2) and methanol (MeOH, 12.6 wt % H2) can be obtained renewably and are excellent prospective liquid CHS materials. In addition, MeOH has considerable potential both as a direct replacement for gasoline and as a fuel cell input. The current commercial syntheses of FA and MeOH, however, use nonrenewable feedstocks and will not facilitate the use of these molecules for CHS. An appealing option for the sustainable synthesis of both FA and MeOH, which could be implemented on a large scale, is the direct metal catalyzed hydrogenation of CO2. Furthermore, given that CO2 is a readily available, nontoxic and inexpensive source of carbon, it is expected that there will be economic and environmental benefits from using CO2 as a feedstock. One strategy to facilitate both the dehydrogenation of FA and MeOH and the hydrogenation of CO2 and H2 to FA and MeOH is to utilize a homogeneous transition metal catalyst. In particular, the development of catalysts based on first row transition metals, which are cheaper, and more abundant than their precious metal counterparts, is desirable. In this Account, we describe recent advances in the development of iron and cobalt systems for the hydrogenation of CO2 to FA and MeOH and the dehydrogenation of FA and MeOH and provide a brief comparison between precious metal and base metal systems. We highlight the different ligands that have been used to stabilize first row transition metal catalysts and discuss the use of additives to promote catalytic activity. In particular, the Account focuses on the crucial role that alkali metal Lewis

  5. Ionic liquid supported acid/base-catalyzed production of biodiesel.

    PubMed

    Lapis, Alexandre A M; de Oliveira, Luciane F; Neto, Brenno A D; Dupont, Jairton

    2008-01-01

    The transesterification (alcoholysis) reaction was successfully applied to synthesize biodiesel from vegetable oils using imidazolium-based ionic liquids under multiphase acidic and basic conditions. Under basic conditions, the combination of the ionic liquid 1-n-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide (BMINTf2), alcohols, and K2CO3 (40 mol %) results in the production of biodiesel from soybean oil in high yields (>98%) and purity. H2SO4 immobilized in BMINTf2 efficiently promotes the transesterification reaction of soybean oil and various primary and secondary alcohols. In this multiphase process the acid is almost completely retained in the ionic liquid phase, while the biodiesel forms a separate phase. The recovered ionic liquid containing the acid could be reused at least six times without any significant loss in the biodiesel yield or selectivity. In both catalytic processes (acid and base), the reactions proceed as typical multiphasic systems in which the formed biodiesel accumulates as the upper phase and the glycerol by-product is selectively captured by the alcohol-ionic liquid-acid/base phase. Classical ionic liquids such as 1-n-butyl-3-methylimidazolium tetrafluoroborate and hexafluorophosphate are not stable under these acidic or basic conditions and decompose.

  6. Is an attention-based associative account of adjacent and nonadjacent dependency learning valid?

    PubMed

    Pacton, Sébastien; Sobaco, Amélie; Perruchet, Pierre

    2015-05-01

    Pacton and Perruchet (2008) reported that participants who were asked to process adjacent elements located within a sequence of digits learned adjacent dependencies but did not learn nonadjacent dependencies and conversely, participants who were asked to process nonadjacent digits learned nonadjacent dependencies but did not learn adjacent dependencies. In the present study, we showed that when participants were simply asked to read aloud the same sequences of digits, a task demand that did not require the intentional processing of specific elements as in standard statistical learning tasks, only adjacent dependencies were learned. The very same pattern was observed when digits were replaced by syllables. These results show that the perfect symmetry found in Pacton and Perruchet was not due to the fact that the processing of digits is less sensitive to their distance than the processing of syllables, tones, or visual shapes used in most statistical learning tasks. Moreover, the present results, completed with a reanalysis of the data collected in Pacton and Perruchet (2008), demonstrate that participants are highly sensitive to violations involving the spacing between paired elements. Overall, these results are consistent with the Pacton and Perruchet's single-process account of adjacent and nonadjacent dependencies, in which the joint attentional processing of the two events is a necessary and sufficient condition for learning the relation between them, irrespective of their distance. However, this account should be completed to encompass the notion that the presence or absence of an intermediate event is an intrinsic component of the representation of an association.

  7. Hierarchical modeling of contingency-based source monitoring: a test of the probability-matching account.

    PubMed

    Arnold, Nina R; Bayen, Ute J; Kuhlmann, Beatrice G; Vaterrodt, Bianca

    2013-04-01

    According to the probability-matching account of source guessing (Spaniol & Bayen, Journal of Experimental Psychology: Learning, Memory, and Cognition 28:631-651, 2002), when people do not remember the source of an item in a source-monitoring task, they match the source-guessing probabilities to the perceived contingencies between sources and item types. In a source-monitoring experiment, half of the items presented by each of two sources were consistent with schematic expectations about this source, whereas the other half of the items were consistent with schematic expectations about the other source. Participants' source schemas were activated either at the time of encoding or just before the source-monitoring test. After test, the participants judged the contingency of the item type and source. Individual parameter estimates of source guessing were obtained via beta-multinomial processing tree modeling (beta-MPT; Smith & Batchelder, Journal of Mathematical Psychology 54:167-183, 2010). We found a significant correlation between the perceived contingency and source guessing, as well as a correlation between the deviation of the guessing bias from the true contingency and source memory when participants did not receive the schema information until retrieval. These findings support the probability-matching account.

  8. A computational study of ultrafast acid dissociation and acid-base neutralization reactions. I. The model

    NASA Astrophysics Data System (ADS)

    Maurer, Patrick; Thomas, Vibin; Rivard, Ugo; Iftimie, Radu

    2010-07-01

    Ultrafast, time-resolved investigations of acid-base neutralization reactions have recently been performed using systems containing the photoacid 8-hydroxypyrene-1,3,6-trisulfonic acid trisodium salt (HPTS) and various Brønsted bases. Two conflicting neutralization mechanisms have been formulated by Mohammed et al. [Science 310, 83 (2005)] and Siwick et al. [J. Am. Chem. Soc. 129, 13412 (2007)] for the same acid-base system. Herein an ab initio molecular dynamics based computational model is formulated, which is able to investigate the validity of the proposed mechanisms in the general context of ground-state acid-base neutralization reactions. Our approach consists of using 2,4,6-tricyanophenol (exp. pKa≅1) as a model for excited-state HPTS∗ (pKa≅1.4) and carboxylate ions for the accepting base. We employ our recently proposed dipole-field/quantum mechanics (QM) treatment [P. Maurer and R. Iftimie, J. Chem. Phys. 132, 074112 (2010)] of the proton donor and acceptor molecules. This approach allows one to tune the free energy of neutralization to any desired value as well as model initial nonequilibrium hydration effects caused by a sudden increase in acidity, making it possible to achieve a more realistic comparison with experimental data than could be obtained via a full-QM treatment of the entire system. It is demonstrated that the dipole-field/QM model reproduces correctly key properties of the 2,4,6-tricyanophenol acid molecule including gas-phase proton dissociation energies and dipole moments, and condensed-phase hydration structure and pKa values.

  9. Acid-base properties of humic and fulvic acids formed during composting.

    PubMed

    Plaza, César; Senesi, Nicola; Polo, Alfredo; Brunetti, Gennaro

    2005-09-15

    The soil acid-base buffering capacity and the biological availability, mobilization, and transport of macro- and micronutrients, toxic metal ions, and xenobiotic organic cations in soil are strongly influenced by the acid-base properties of humic substances, of which humic and fulvic acids are the major fractions. For these reasons, the proton binding behavior of the humic acid-like (HA) and fulvic acid-like (FA) fractions contained in a compost are believed to be instrumental in its successful performance in soil. In this work, the acid-base properties of the HAs and FAs isolated from a mixture of the sludge residue obtained from olive oil mill wastewater (OMW) evaporated in an open-air pond and tree cuttings (TC) at different stages of composting were investigated by a current potentiometric titration method and the nonideal competitive adsorption (NICA)-Donnan model. The NICA-Donnan model provided an excellent description of the acid-base titration data, and pointed out substantial differences in site density and proton-binding affinity between the HAs and FAs examined. With respect to FAs, HAs were characterized by a smaller content of carboxylic- and phenolic-type groups and their larger affinities for proton binding. Further, HAs featured a greater heterogeneity in carboxylic-type groups than FAs. The composting process increased the content and decreased the proton affinity of carboxylic- and phenolic-type groups of HAs and FAs, and increased the heterogeneity of phenolic-type groups of HAs. As a whole, these effects indicated that the composting process could produce HA and FA fractions with greater cation binding capacities. These results suggest that composting of organic materials improves their agronomic and environmental value by increasing their potential to retain and exchange macro- and micronutrients, and to reduce the bioavailability of organic and inorganic pollutants.

  10. Deoxyribonucleic acid base compositions of dermatophytes.

    PubMed

    Davison, F D; Mackenzie, D W; Owen, R J

    1980-06-01

    DNA was extracted and purified from 55 dermatophyte isolates representing 34 species of Trichophyton, Microsporum and Epidermophyton. The base compositions of the chromosomal DNA were determined by CsCl density gradient centrifugation and were found to be in the narrow range of 48.7 to 50.3 mol % G + C. A satellite DNA component assumed to be of mitochondrial origin was present in most strains, with a G + C content ranging from 14.7 to 30.8 mol % G + C. Heterogeneity in microscopic and colonial characteristics was not reflected in differences in the mean G + C content of the chromosomal DNAs. Strains varied in the G + C contents of satelite DNA, but these did not correlate with traditional species concepts.

  11. A unified account of tilt illusions, association fields, and contour detection based on elastica.

    PubMed

    Keemink, Sander W; van Rossum, Mark C W

    2016-09-01

    As expressed in the Gestalt law of good continuation, human perception tends to associate stimuli that form smooth continuations. Contextual modulation in primary visual cortex, in the form of association fields, is believed to play an important role in this process. Yet a unified and principled account of the good continuation law on the neural level is lacking. In this study we introduce a population model of primary visual cortex. Its contextual interactions depend on the elastica curvature energy of the smoothest contour connecting oriented bars. As expected, this model leads to association fields consistent with data. However, in addition the model displays tilt-illusions for stimulus configurations with grating and single bars that closely match psychophysics. Furthermore, the model explains not only pop-out of contours amid a variety of backgrounds, but also pop-out of single targets amid a uniform background. We thus propose that elastica is a unifying principle of the visual cortical network.

  12. Water accounting for stressed river basins based on water resources management models.

    PubMed

    Pedro-Monzonís, María; Solera, Abel; Ferrer, Javier; Andreu, Joaquín; Estrela, Teodoro

    2016-09-15

    Water planning and the Integrated Water Resources Management (IWRM) represent the best way to help decision makers to identify and choose the most adequate alternatives among other possible ones. The System of Environmental-Economic Accounting for Water (SEEA-W) is displayed as a tool for the building of water balances in a river basin, providing a standard approach to achieve comparability of the results between different territories. The target of this paper is to present the building up of a tool that enables the combined use of hydrological models and water resources models to fill in the SEEA-W tables. At every step of the modelling chain, we are capable to build the asset accounts and the physical water supply and use tables according to SEEA-W approach along with an estimation of the water services costs. The case study is the Jucar River Basin District (RBD), located in the eastern part of the Iberian Peninsula in Spain which as in other many Mediterranean basins is currently water-stressed. To guide this work we have used PATRICAL model in combination with AQUATOOL Decision Support System (DSS). The results indicate that for the average year the total use of water in the district amounts to 15,143hm(3)/year, being the Total Water Renewable Water Resources 3909hm(3)/year. On the other hand, the water service costs in Jucar RBD amounts to 1634 million € per year at constant 2012 prices. It is noteworthy that 9% of these costs correspond to non-conventional resources, such as desalinated water, reused water and water transferred from other regions.

  13. Virial based equations of state with account of three-body interaction for noble gases and their mixtures

    NASA Astrophysics Data System (ADS)

    Akhmatov, Z. A.; Khokonov, A. Kh; Khokonov, M. Kh

    2016-11-01

    Within the frame of molecular dynamics the equations of state of noble gases and their mixtures have been obtained by means of time averaging procedure for virial based equation with account of three-body interaction. It has been shown, that equations of state can be extrapolated by van-der-Waals-type equations. The corresponding parameters have been calculated. A visible foliation of Xe and Kr components of Kob-Andersen mixture has been found.

  14. How to Tell the Truth with Statistics: The Case for Accountable Data Analyses in Team-based Science

    PubMed Central

    Gelfond, Jonathan A. L.; Klugman, Craig M.; Welty, Leah J.; Heitman, Elizabeth; Louden, Christopher; Pollock, Brad H.

    2015-01-01

    Data analysis is essential to translational medicine, epidemiology, and the scientific process. Although recent advances in promoting reproducibility and reporting standards have made some improvements, the data analysis process remains insufficiently documented and susceptible to avoidable errors, bias, and even fraud. Comprehensively accounting for the full analytical process requires not only records of the statistical methodology used, but also records of communications among the research team. In this regard, the data analysis process can benefit from the principle of accountability that is inherent in other disciplines such as clinical practice. We propose a novel framework for capturing the analytical narrative called the Accountable Data Analysis Process (ADAP), which allows the entire research team to participate in the analysis in a supervised and transparent way. The framework is analogous to an electronic health record in which the dataset is the “patient” and actions related to the dataset are recorded in a project management system. We discuss the design, advantages, and challenges in implementing this type of system in the context of academic health centers, where team based science increasingly demands accountability. PMID:26290897

  15. Relativistic effects on acidities and basicities of Brønsted acids and bases containing gold.

    PubMed

    Koppel, Ilmar A; Burk, Peeter; Kasemets, Kalev; Koppel, Ivar

    2013-11-07

    It is usually believed that relativistic effects as described by the Dirac-Schrödinger equation (relative to the classical or time-independent Schrödinger equation) are of little importance in chemistry. A closer look, however, reveals that some important and widely known properties (e.g., gold is yellow, mercury is liquid at room temperature) stem from relativistic effects. So far the influence of relativistic effects on the acid-base properties has been mostly ignored. Here we show that at least for compounds of gold such omission is completely erroneous and would lead to too high basicity and too low acidity values with errors in the range of 25-55 kcal mol(-1) (or 20 to 44 powers of ten in pK(a) units) in the gas-phase. These findings have important implications for the design of new superstrong acids and bases, and for the understanding of gold-catalysed reactions.

  16. Acid-Base Titration of (S)-Aspartic Acid: A Circular Dichroism Spectrophotometry Experiment

    NASA Astrophysics Data System (ADS)

    Cavaleiro, Ana M. V.; Pedrosa de Jesus, Júlio D.

    2000-09-01

    The magnitude of the circular dichroism of (S)-aspartic acid in aqueous solutions at a fixed wavelength varies with the addition of strong base. This laboratory experiment consists of the circular dichroism spectrophotometric acid-base titration of (S)-aspartic acid in dilute aqueous solutions, and the use of the resulting data to determine the ionization constant of the protonated amino group. The work familiarizes students with circular dichroism and illustrates the possibility of performing titrations using a less usual instrumental method of following the course of a reaction. It shows the use of a chiroptical property in the determination of the concentration in solution of an optically active molecule, and exemplifies the use of a spectrophotometric titration in the determination of an ionization constant.

  17. Site-Based Management versus Systems-Based Thinking: The Impact of Data-Driven Accountability and Reform

    ERIC Educational Resources Information Center

    Mette, Ian M.; Bengtson, Ed

    2015-01-01

    This case was written to help prepare building-level and central office administrators who are expected to effectively lead schools and systems in an often tumultuous world of educational accountability and reform. The intent of this case study is to allow educators to examine the impact data management has on the types of thinking required when…

  18. When Creative Problem Solving Strategy Meets Web-Based Cooperative Learning Environment in Accounting Education

    ERIC Educational Resources Information Center

    Cheng, Kai Wen

    2011-01-01

    Background: Facing highly competitive and changing environment, cultivating citizens with problem-solving attitudes is one critical vision of education. In brief, the importance of education is to cultivate students with practical abilities. Realizing the advantages of web-based cooperative learning (web-based CL) and creative problem solving…

  19. Negotiating Accountability during Student Teaching: The Influence of an Inquiry-Based Student Teaching Seminar

    ERIC Educational Resources Information Center

    Cuenca, Alexander

    2014-01-01

    Drawing on the work of Russian literary critic, Mikhail Bakhtin, this article explores how an inquiry-based social studies student teaching seminar helped three preservice teachers negotiate the pressures of standards-based reforms during student teaching. The author first examines how initial perceptions of standardization and high-stakes testing…

  20. Accounting & Computing Curriculum Guide.

    ERIC Educational Resources Information Center

    Avani, Nathan T.; And Others

    This curriculum guide consists of materials for use in teaching a competency-based accounting and computing course that is designed to prepare students for employability in the following occupational areas: inventory control clerk, invoice clerk, payroll clerk, traffic clerk, general ledger bookkeeper, accounting clerk, account information clerk,…

  1. Nucleic acid-based nanoengineering: novel structures for biomedical applications

    PubMed Central

    Li, Hanying; LaBean, Thomas H.; Leong, Kam W.

    2011-01-01

    Nanoengineering exploits the interactions of materials at the nanometre scale to create functional nanostructures. It relies on the precise organization of nanomaterials to achieve unique functionality. There are no interactions more elegant than those governing nucleic acids via Watson–Crick base-pairing rules. The infinite combinations of DNA/RNA base pairs and their remarkable molecular recognition capability can give rise to interesting nanostructures that are only limited by our imagination. Over the past years, creative assembly of nucleic acids has fashioned a plethora of two-dimensional and three-dimensional nanostructures with precisely controlled size, shape and spatial functionalization. These nanostructures have been precisely patterned with molecules, proteins and gold nanoparticles for the observation of chemical reactions at the single molecule level, activation of enzymatic cascade and novel modality of photonic detection, respectively. Recently, they have also been engineered to encapsulate and release bioactive agents in a stimulus-responsive manner for therapeutic applications. The future of nucleic acid-based nanoengineering is bright and exciting. In this review, we will discuss the strategies to control the assembly of nucleic acids and highlight the recent efforts to build functional nucleic acid nanodevices for nanomedicine. PMID:23050076

  2. Crystal and molecular structure of eight organic acid-base adducts from 2-methylquinoline and different acids

    NASA Astrophysics Data System (ADS)

    Zhang, Jing; Jin, Shouwen; Tao, Lin; Liu, Bin; Wang, Daqi

    2014-08-01

    Eight supramolecular complexes with 2-methylquinoline and acidic components as 4-aminobenzoic acid, 2-aminobenzoic acid, salicylic acid, 5-chlorosalicylic acid, 3,5-dinitrosalicylic acid, malic acid, sebacic acid, and 1,5-naphthalenedisulfonic acid were synthesized and characterized by X-ray crystallography, IR, mp, and elemental analysis. All of the complexes are organic salts except compound 2. All supramolecular architectures of 1-8 involve extensive classical hydrogen bonds as well as other noncovalent interactions. The results presented herein indicate that the strength and directionality of the classical hydrogen bonds (ionic or neutral) between acidic components and 2-methylquinoline are sufficient to bring about the formation of binary organic acid-base adducts. The role of weak and strong noncovalent interactions in the crystal packing is ascertained. These weak interactions combined, the complexes 1-8 displayed 2D-3D framework structure.

  3. Zebrafish Seizure Model Identifies p,p′-DDE as the Dominant Contaminant of Fetal California Sea Lions That Accounts for Synergistic Activity with Domoic Acid

    PubMed Central

    Tiedeken, Jessica A.; Ramsdell, John S.

    2010-01-01

    Background Fetal poisoning of California sea lions (CSLs; Zalophus californianus) has been associated with exposure to the algal toxin domoic acid. These same sea lions accumulate a mixture of persistent environmental contaminants including pesticides and industrial products such as polychlorinated biphenyls (PCBs) and polybrominated diphenyl ethers (PBDEs). Developmental exposure to the pesticide dichlorodiphenyltrichloroethane (DDT) and its stable metabolite 1,1-bis-(4-chlorophenyl)-2,2-dichloroethene (p,p′-DDE) has been shown to enhance domoic acid–induced seizures in zebrafish; however, the contribution of other co-occurring contaminants is unknown. Objective We formulated a mixture of contaminants to include PCBs, PBDEs, hexachlorocyclohexane (HCH), and chlordane at levels matching those reported for fetal CSL blubber to determine the impact of co-occurring persistent contaminants with p,p′-DDE on chemically induced seizures in zebrafish as a model for the CSLs. Methods Embryos were exposed (6–30 hr postfertilization) to p,p′-DDE in the presence or absence of a defined contaminant mixture prior to neurodevelopment via either bath exposure or embryo yolk sac microinjection. After brain maturation (7 days postfertilization), fish were exposed to a chemical convulsant, either pentylenetetrazole or domoic acid; resulting seizure behavior was then monitored and analyzed for changes, using cameras and behavioral tracking software. Results Induced seizure behavior did not differ significantly between subjects with embryonic exposure to a contaminant mixture and those exposed to p,p′-DDE only. Conclusion These studies demonstrate that p,p′-DDE—in the absence of PCBs, HCH, chlordane, and PBDEs that co-occur in fetal sea lions—accounts for the synergistic activity that leads to greater sensitivity to domoic acid seizures. PMID:20368122

  4. A biomimetic vision-based hovercraft accounts for bees' complex behaviour in various corridors.

    PubMed

    Roubieu, Frédéric L; Serres, Julien R; Colonnier, Fabien; Franceschini, Nicolas; Viollet, Stéphane; Ruffier, Franck

    2014-09-01

    Here we present the first systematic comparison between the visual guidance behaviour of a biomimetic robot and those of honeybees flying in similar environments. We built a miniature hovercraft which can travel safely along corridors with various configurations. For the first time, we implemented on a real physical robot the 'lateral optic flow regulation autopilot', which we previously studied computer simulations. This autopilot inspired by the results of experiments on various species of hymenoptera consists of two intertwined feedback loops, the speed and lateral control loops, each of which has its own optic flow (OF) set-point. A heading-lock system makes the robot move straight ahead as fast as 69 cm s(-1) with a clearance from one wall as small as 31 cm, giving an unusually high translational OF value (125° s(-1)). Our biomimetic robot was found to navigate safely along straight, tapered and bent corridors, and to react appropriately to perturbations such as the lack of texture on one wall, the presence of a tapering or non-stationary section of the corridor and even a sloping terrain equivalent to a wind disturbance. The front end of the visual system consists of only two local motion sensors (LMS), one on each side. This minimalistic visual system measuring the lateral OF suffices to control both the robot's forward speed and its clearance from the walls without ever measuring any speeds or distances. We added two additional LMSs oriented at +/-45° to improve the robot's performances in stiffly tapered corridors. The simple control system accounts for worker bees' ability to navigate safely in six challenging environments: straight corridors, single walls, tapered corridors, straight corridors with part of one wall moving or missing, as well as in the presence of wind.

  5. Acid-base metabolism: implications for kidney stones formation.

    PubMed

    Hess, Bernhard

    2006-04-01

    The physiology and pathophysiology of renal H+ ion excretion and urinary buffer systems are reviewed. The main focus is on the two major conditions related to acid-base metabolism that cause kidney stone formation, i.e., distal renal tubular acidosis (dRTA) and abnormally low urine pH with subsequent uric acid stone formation. Both the entities can be seen on the background of disturbances of the major urinary buffer system, NH3+ <--> NH4+. On the one hand, reduced distal tubular secretion of H+ ions results in an abnormally high urinary pH and either incomplete or complete dRTA. On the other hand, reduced production/availability of NH4+ is the cause of an abnormally low urinary pH, which predisposes to uric acid stone formation. Most recent research indicates that the latter abnormality may be a renal manifestation of the increasingly prevalent metabolic syndrome. Despite opposite deviations from normal urinary pH values, both the dRTA and uric acid stone formation due to low urinary pH require the same treatment, i.e., alkali. In the dRTA, alkali is needed for improving the body's buffer capacity, whereas the goal of alkali treatment in uric acid stone formers is to increase the urinary pH to 6.2-6.8 in order to minimize uric acid crystallization.

  6. Evolution of Acid-Base Concept (1917-1984).

    ERIC Educational Resources Information Center

    Gamble, James L., Jr.

    1984-01-01

    Evaluates the accuracy and usefulness of a simpler rationale for teaching acid-base physiology as compared to more complex approaches frequently taught in physiology courses. Also reviews problems of terminology, giving emphasis to the significant effects that the choice of words can have on students' concepts. (JN)

  7. Using Spreadsheets to Produce Acid-Base Titration Curves.

    ERIC Educational Resources Information Center

    Cawley, Martin James; Parkinson, John

    1995-01-01

    Describes two spreadsheets for producing acid-base titration curves, one uses relatively simple cell formulae that can be written into the spreadsheet by inexperienced students and the second uses more complex formulae that are best written by the teacher. (JRH)

  8. Linear titration plots for polyfunctional weak acids and bases.

    PubMed

    Midgley, D; McCallum, C

    1976-04-01

    Procedures are derived for obtaining the equivalence volumes in the potentiometric titrations of polyfunctional weak acids and weak bases by a linear titration plot method. The effect of errors in the equilibrium constants on the accuracy is considered. A Fortran program is available to do the calculations.

  9. Dynamic Buffer Capacity in Acid-Base Systems.

    PubMed

    Michałowska-Kaczmarczyk, Anna M; Michałowski, Tadeusz

    The generalized concept of 'dynamic' buffer capacity βV is related to electrolytic systems of different complexity where acid-base equilibria are involved. The resulting formulas are presented in a uniform and consistent form. The detailed calculations are related to two Britton-Robinson buffers, taken as examples.

  10. Acid-Base Disorders--A Computer Simulation.

    ERIC Educational Resources Information Center

    Maude, David L.

    1985-01-01

    Describes and lists a program for Apple Pascal Version 1.1 which investigates the behavior of the bicarbonate-carbon dioxide buffer system in acid-base disorders. Designed specifically for the preclinical medical student, the program has proven easy to use and enables students to use blood gas parameters to arrive at diagnoses. (DH)

  11. Students' Understanding of Acids/Bases in Organic Chemistry Contexts

    ERIC Educational Resources Information Center

    Cartrette, David P.; Mayo, Provi M.

    2011-01-01

    Understanding key foundational principles is vital to learning chemistry across different contexts. One such foundational principle is the acid/base behavior of molecules. In the general chemistry sequence, the Bronsted-Lowry theory is stressed, because it lends itself well to studying equilibrium and kinetics. However, the Lewis theory of…

  12. Turkish Prospective Chemistry Teachers' Alternative Conceptions about Acids and Bases

    ERIC Educational Resources Information Center

    Boz, Yezdan

    2009-01-01

    The purpose of this study was to obtain prospective chemistry teachers' conceptions about acids and bases concepts. Thirty-eight prospective chemistry teachers were the participants. Data were collected by means of an open-ended questionnaire and semi-structured interviews. Analysis of data indicated that most prospective teachers did not have…

  13. Hard and soft acids and bases: small molecules.

    PubMed

    Reed, James L

    2009-08-03

    The operational chemical hardness has been determined for the hydride, chloride, and fluoride derivatives of the anionic atomic bases of the second period. Of interest is the identification of the structure and associated processes that give rise to hard-soft behavior in small molecules. The Pearson Principle of Hard and Soft Acids and Bases has been taken to be the defining statement about hard-soft behavior and as a definition of chemical hardness. Similar to the case for atoms, the molecule's responding electrons have been identified as the structure giving rise to hard-soft behavior, and a relaxation described by a modified Slater model has been identified as the associated process. The responding electrons are the molecule's valence electrons that are not undergoing electron transfer in an acid-base interaction. However, it has been demonstrated that chemical hardness is a local property, and only those responding electrons that are associated with the base's binding atom directly impact chemical hardness.

  14. Discriminating bot accounts based solely on temporal features of microblog behavior

    NASA Astrophysics Data System (ADS)

    Pan, Junshan; Liu, Ying; Liu, Xiang; Hu, Hanping

    2016-05-01

    As the largest microblog service in China, Sina Weibo has attracted numerous automated applications (known as bots) due to its popularity and open architecture. We classify the active users from Sina Weibo into human, bot-based and hybrid groups based solely on the study of temporal features of their posting behavior. The anomalous burstiness parameter and time-interval entropy value are exploited to characterize automation. We also reveal different behavior patterns among the three types of users regarding their reposting ratio, daily rhythm and active days. Our findings may help Sina Weibo manage a better community and should be considered for dynamic models of microblog behaviors.

  15. Adventure-Based Service Learning: University Students' Self-Reflection Accounts of Service with Children

    ERIC Educational Resources Information Center

    Quezada, Reyes L.; Christopherson, Richard W.

    2005-01-01

    The need to provide alternative and exciting community service-learning experiences with university students has been a challenge to institutions of higher education. One institution was able to capitalize on an idea of integrating challenge and adventure-based activities as a form of community service. This article focuses on undergraduate…

  16. Bringing Technology to Students' Proximity: A Sociocultural Account of Technology-Based Learning Projects

    ERIC Educational Resources Information Center

    Mukama, Evode

    2014-01-01

    This paper depicts a study carried out in Rwanda concerning university students who participated in a contest to produce short documentary films. The purpose of this research is to conceptualize these kinds of technology-based learning projects (TBLPs) through a sociocultural perspective. The methodology included focus-group discussions and field…

  17. Bringing Technology to Students' Proximity: A Sociocultural Account of Technology-Based Learning Projects

    ERIC Educational Resources Information Center

    Mukama, Evode

    2014-01-01

    This paper depicts a study carried out in Rwanda concerning university students who participated in a contest to produce short documentary films. The purpose of this research is to conceptualize these kinds of technology-based learning projects (TBLPs) through a sociocultural perspective. The methodology included focus group discussions and field…

  18. ACCOUNTING FOR BIOLOGICAL AND ANTHROPOGENIC FACTORS IN NATIONAL LAND-BASED CARBON BUDGETS

    EPA Science Inventory

    Efforts to quantify net greenhouse gas emissions at the national scale, as required by the United Nations Framework Convention on Climate Change, must include both industrial emissions and the net flux associated with the land base. In this study, data on current land use, rates ...

  19. Effectiveness and Accountability of the Inquiry-Based Methodology in Middle School Science

    ERIC Educational Resources Information Center

    Hardin, Cade

    2009-01-01

    When teaching science, the time allowed for students to make discoveries on their own through the inquiry method directly conflicts with the mandated targets of a broad spectrum of curricula. Research shows that using an inquiry-based approach can encourage student motivation and increase academic achievement (Wolf & Fraser, 2008, Bryant, 2006,…

  20. The Social Foundation of Team-Based Learning: Students Accountable to Students

    ERIC Educational Resources Information Center

    Sweet, Michael; Pelton-Sweet, Laura M.

    2008-01-01

    As one form of small group learning, team-based learning's (TBL's) unique sequence of individual and group work with immediate feedback enables and encourages students to engage course content and each other in remarkable ways. Specifically, TBL creates an environment where students can fulfill their human need to belong in the process of…

  1. Frequency Affects Object Relative Clause Processing: Some Evidence in Favor of Usage-Based Accounts

    ERIC Educational Resources Information Center

    Reali, Florencia

    2014-01-01

    The processing difficulty of nested grammatical structure has been explained by different psycholinguistic theories. Here I provide corpus and behavioral evidence in favor of usage-based models, focusing on the case of object relative clauses in Spanish as a first language. A corpus analysis of spoken Spanish reveals that, as in English, the…

  2. Place-Based Pedagogy in the Era of Accountability: An Action Research Study

    ERIC Educational Resources Information Center

    Saracino, Peter C.

    2010-01-01

    Today's most common method of teaching biology--driven by calls for standardization and high-stakes testing--relies on a standards-based, de-contextualized approach to education. This results in "one size fits all" curriculums that ignore local contexts relevant to students' lives, discourage student engagement and ultimately work against a deep…

  3. Audit Culture: Unintended Consequences of Accountability Practices in Evidence-Based Programs

    ERIC Educational Resources Information Center

    Owczarzak, Jill; Broaddus, Michelle; Pinkerton, Steven

    2016-01-01

    Evaluation has become expected within the nonprofit sector, including HIV prevention service delivery through community-based organizations (CBOs). While staff and directors at CBOs may acknowledge the potential contribution of evaluation data to the improvement of agency services, the results of evaluation are often used to demonstrate fiscal…

  4. Temporal Adverbials, Negation and Finiteness in Dutch as a Second Language: A Scope-Based Account

    ERIC Educational Resources Information Center

    Verhagen, Josje

    2009-01-01

    This study investigates the acquisition of post-verbal (temporal) adverbials and post-verbal negation in L2 Dutch. It is based on previous findings for L2 French that post-verbal negation poses less of a problem for L2 learners than post-verbal adverbial placement (Hawkins, Towell, Bazergui, Second Language Research 9: 189-233, 1993; Herschensohn,…

  5. Place-based pedagogy in the era of accountability: An action research study

    NASA Astrophysics Data System (ADS)

    Saracino, Peter C.

    Today's most common method of teaching biology---driven by calls for standardization and high-stakes testing---relies on a standards-based, de-contextualized approach to education. This results in "one size fits all" curriculums that ignore local contexts relevant to students' lives, discourage student engagement and ultimately work against a deep and lasting understanding of content. In contrast, place-based education---a pedagogical paradigm grounded in situated cognition and the progressive education tradition of John Dewey---utilizes the community as an integrating context for learning. It encourages the growth of school-community partnerships with an eye towards raising student achievement while also drawing students into the economic, political, social and ecological life of their communities. Such an approach seeks to provide students with learning experiences that are both academically significant and valuable to their communities. This study explores how high school science teachers can capitalize on the rich affordances offered by a place-based approach despite the constraints imposed by a state-mandated curriculum and high-stakes testing. Using action research, I designed, implemented, evaluated and refined an intervention that grounded a portion of a Living Environment high school course I teach in a place-based experience. This experience served as a unique anchoring event to contextualize students' learning of other required core topics. The overarching question framing this study is: How can science teachers capitalize on the rich affordances offered by a place-based approach despite the constraints imposed by a state-mandated curriculum and high-stakes testing? The following more specific questions were explored within the context of the intervention: (1) Which elements of the place-based paradigm could I effectively integrate into a Living Environment course? (2) In what ways would this integration impact students' interest? (3) In what ways would

  6. Acid-base thermochemistry of gaseous oxygen and sulfur substituted amino acids (Ser, Thr, Cys, Met).

    PubMed

    Riffet, Vanessa; Frison, Gilles; Bouchoux, Guy

    2011-11-07

    Acid-base thermochemistry of isolated amino acids containing oxygen or sulfur in their side chain (serine, threonine, cysteine and methionine) have been examined by quantum chemical computations. Density functional theory (DFT) was used, with B3LYP, B97-D and M06-2X functionals using the 6-31+G(d,p) basis set for geometry optimizations and the larger 6-311++G(3df,2p) basis set for energy computations. Composite methods CBS-QB3, G3B3, G4MP2 and G4 were applied to large sets of neutral, protonated and deprotonated conformers. Conformational analysis of these species, based on chemical approach and AMOEBA force field calculations, has been used to identify the lowest energy conformers and to estimate the population of conformers expected to be present at thermal equilibrium at 298 K. It is observed that G4, G4MP2, G3B3, CBS-QB3 composite methods and M06-2X DFT lead to similar conformer energies. Thermochemical parameters have been computed using either the most stable conformers or equilibrium populations of conformers. Comparison of experimental and theoretical proton affinities and Δ(acid)H shows that the G4 method provides the better agreement with deviations of less than 1.5 kJ mol(-1). From this point of view, a set of evaluated thermochemical quantities for serine, threonine, cysteine and methionine may be proposed: PA = 912, 919, 903, 938; GB = 878, 886, 870, 899; Δ(acid)H = 1393, 1391, 1396, 1411; Δ(acid)G = 1363, 1362, 1367, 1382 kJ mol(-1). This study also confirms that a non-negligible ΔpS° is associated with protonation of methionine and that the most acidic hydrogen of cysteine in the gas phase is that of the SH group. In several instances new conformers were identified thus suggesting a re-examination of several IRMPD spectra.

  7. Design of an activity landscape view taking compound-based feature probabilities into account.

    PubMed

    Zhang, Bijun; Vogt, Martin; Bajorath, Jürgen

    2014-09-01

    Activity landscapes (ALs) of compound data sets are rationalized as graphical representations that integrate similarity and potency relationships between active compounds. ALs enable the visualization of structure-activity relationship (SAR) information and are thus computational tools of interest for medicinal chemistry. For AL generation, similarity and potency relationships are typically evaluated in a pairwise manner and major AL features are assessed at the level of compound pairs. In this study, we add a conditional probability formalism to AL design that makes it possible to quantify the probability of individual compounds to contribute to characteristic AL features. Making this information graphically accessible in a molecular network-based AL representation is shown to further increase AL information content and helps to quickly focus on SAR-informative compound subsets. This feature probability-based AL variant extends the current spectrum of AL representations for medicinal chemistry applications.

  8. Design of an activity landscape view taking compound-based feature probabilities into account

    NASA Astrophysics Data System (ADS)

    Zhang, Bijun; Vogt, Martin; Bajorath, Jürgen

    2014-09-01

    Activity landscapes (ALs) of compound data sets are rationalized as graphical representations that integrate similarity and potency relationships between active compounds. ALs enable the visualization of structure-activity relationship (SAR) information and are thus computational tools of interest for medicinal chemistry. For AL generation, similarity and potency relationships are typically evaluated in a pairwise manner and major AL features are assessed at the level of compound pairs. In this study, we add a conditional probability formalism to AL design that makes it possible to quantify the probability of individual compounds to contribute to characteristic AL features. Making this information graphically accessible in a molecular network-based AL representation is shown to further increase AL information content and helps to quickly focus on SAR-informative compound subsets. This feature probability-based AL variant extends the current spectrum of AL representations for medicinal chemistry applications.

  9. What Part of "No" Do Children Not Understand? A Usage-Based Account of Multiword Negation

    ERIC Educational Resources Information Center

    Cameron-Faulkner, Thea; Lieven, Elena; Theakston, Anna

    2007-01-01

    The study investigates the development of English multiword negation, in particular the negation of zero marked verbs (e.g. "no sleep", "not see", "can't reach") from a usage-based perspective. The data was taken from a dense database consisting of the speech of an English-speaking child (Brian) aged 2;3-3;4 (MLU 2.05-3.1) and his mother. The…

  10. Accounting for linkage in family-based tests of association with missing parental genotypes.

    PubMed

    Martin, Eden R; Bass, Meredyth P; Hauser, Elizabeth R; Kaplan, Norman L

    2003-11-01

    In studies of complex diseases, a common paradigm is to conduct association analysis at markers in regions identified by linkage analysis, to attempt to narrow the region of interest. Family-based tests for association based on parental transmissions to affected offspring are often used in fine-mapping studies. However, for diseases with late onset, parental genotypes are often missing. Without parental genotypes, family-based tests either compare allele frequencies in affected individuals with those in their unaffected siblings or use siblings to infer missing parental genotypes. An example of the latter approach is the score test implemented in the computer program TRANSMIT. The inference of missing parental genotypes in TRANSMIT assumes that transmissions from parents to affected siblings are independent, which is appropriate when there is no linkage. However, using computer simulations, we show that, when the marker and disease locus are linked and the data set consists of families with multiple affected siblings, this assumption leads to a bias in the score statistic under the null hypothesis of no association between the marker and disease alleles. This bias leads to an inflated type I error rate for the score test in regions of linkage. We present a novel test for association in the presence of linkage (APL) that correctly infers missing parental genotypes in regions of linkage by estimating identity-by-descent parameters, to adjust for correlation between parental transmissions to affected siblings. In simulated data, we demonstrate the validity of the APL test under the null hypothesis of no association and show that the test can be more powerful than the pedigree disequilibrium test and family-based association test. As an example, we compare the performance of the tests in a candidate-gene study in families with Parkinson disease.

  11. Liaison acquisition, word segmentation and construction in French: a usage-based account.

    PubMed

    Chevrot, Jean-Pierre; Dugua, Celine; Fayol, Michel

    2009-06-01

    In the linguistics field, liaison in French is interpreted as an indicator of interactions between the various levels of language organization. The current study examines the same issue while adopting a developmental perspective. Five experiments involving children aged two to six years provide evidence for a developmental scenario which interrelates a number of different issues: the acquisition of phonological alternations, the segmentation of new words, the long-term stabilization of the word form in the lexicon and the formation of item-based constructions. According to this scenario, children favour the presence of initial CV syllables when segmenting stored chunks of speech of the type word1-liaison-word2 (les arbres 'the trees' is segmented as /le/+/zarbr/). They cope with the variation of the liaison in the input by memorizing multiple exemplars of the same word2 (/zarbr/, /narbr/). They learn the correct relations between the word1s and the word2 exemplars through exposure to the well-formed sequence (un+/narbr/, deux+/zarbr/). They generalize the relation between a word1 and a class of word2 exemplars beginning with a specific liaison consonant by integrating this information into an item-based schema (e.g. un+/nX/, deux+/zX/). This model is based on the idea that the segmentation of new words and the development of syntactic schemas are two aspects of the same process.

  12. Acid-base transport in pancreas—new challenges

    PubMed Central

    Novak, Ivana; Haanes, Kristian A.; Wang, Jing

    2013-01-01

    Along the gastrointestinal tract a number of epithelia contribute with acid or basic secretions in order to aid digestive processes. The stomach and pancreas are the most extreme examples of acid (H+) and base (HCO−3) transporters, respectively. Nevertheless, they share the same challenges of transporting acid and bases across epithelia and effectively regulating their intracellular pH. In this review, we will make use of comparative physiology to enlighten the cellular mechanisms of pancreatic HCO−3 and fluid secretion, which is still challenging physiologists. Some of the novel transporters to consider in pancreas are the proton pumps (H+-K+-ATPases), as well as the calcium-activated K+ and Cl− channels, such as KCa3.1 and TMEM16A/ANO1. Local regulators, such as purinergic signaling, fine-tune, and coordinate pancreatic secretion. Lastly, we speculate whether dys-regulation of acid-base transport contributes to pancreatic diseases including cystic fibrosis, pancreatitis, and cancer. PMID:24391597

  13. Coulometric titration of bases in acetic acid and acetonitrile media.

    PubMed

    Vajgand, V J; Mihajlović, R

    1969-09-01

    The working conditions and the results for coulometric titration of milligram amounts of some bases in 0.1M sodium perchlorate in a mixture of acetic acid and acetic anhydride (1:6), are given. Determinations were made both by coulometric back-titration or direct titration at the platinum anode. Back-titration was done in the catholyte, by coulometric titration of the excess of added perchloric acid. The titration end-point was detected photometrically with Crystal Violet as indicator. The direct titration of bases was done at the platinum anode, in the same electrolyte, to which hydroquinone was added as anode depolarizer and as the source of hydrogen ions, Malachite Green being used as indicator. Similarly, bases can be determined in acetonitrile if sodium perchlorate, hydroquinone and Malachite Green are added to the solvent. Errors are below 1 %, and the precision is satisfactory.

  14. Structure-Based Statistical Mechanical Model Accounts for the Causality and Energetics of Allosteric Communication

    PubMed Central

    Guarnera, Enrico; Berezovsky, Igor N.

    2016-01-01

    Allostery is one of the pervasive mechanisms through which proteins in living systems carry out enzymatic activity, cell signaling, and metabolism control. Effective modeling of the protein function regulation requires a synthesis of the thermodynamic and structural views of allostery. We present here a structure-based statistical mechanical model of allostery, allowing one to observe causality of communication between regulatory and functional sites, and to estimate per residue free energy changes. Based on the consideration of ligand free and ligand bound systems in the context of a harmonic model, corresponding sets of characteristic normal modes are obtained and used as inputs for an allosteric potential. This potential quantifies the mean work exerted on a residue due to the local motion of its neighbors. Subsequently, in a statistical mechanical framework the entropic contribution to allosteric free energy of a residue is directly calculated from the comparison of conformational ensembles in the ligand free and ligand bound systems. As a result, this method provides a systematic approach for analyzing the energetics of allosteric communication based on a single structure. The feasibility of the approach was tested on a variety of allosteric proteins, heterogeneous in terms of size, topology and degree of oligomerization. The allosteric free energy calculations show the diversity of ways and complexity of scenarios existing in the phenomenology of allosteric causality and communication. The presented model is a step forward in developing the computational techniques aimed at detecting allosteric sites and obtaining the discriminative power between agonistic and antagonistic effectors, which are among the major goals in allosteric drug design. PMID:26939022

  15. Food composition and acid-base balance: alimentary alkali depletion and acid load in herbivores.

    PubMed

    Kiwull-Schöne, Heidrun; Kiwull, Peter; Manz, Friedrich; Kalhoff, Hermann

    2008-02-01

    Alkali-enriched diets are recommended for humans to diminish the net acid load of their usual diet. In contrast, herbivores have to deal with a high dietary alkali impact on acid-base balance. Here we explore the role of nutritional alkali in experimentally induced chronic metabolic acidosis. Data were collected from healthy male adult rabbits kept in metabolism cages to obtain 24-h urine and arterial blood samples. Randomized groups consumed rabbit diets ad libitum, providing sufficient energy but variable alkali load. One subgroup (n = 10) received high-alkali food and approximately 15 mEq/kg ammonium chloride (NH4Cl) with its drinking water for 5 d. Another group (n = 14) was fed low-alkali food for 5 d and given approximately 4 mEq/kg NH4Cl daily for the last 2 d. The wide range of alimentary acid-base load was significantly reflected by renal base excretion, but normal acid-base conditions were maintained in the arterial blood. In rabbits fed a high-alkali diet, the excreted alkaline urine (pH(u) > 8.0) typically contained a large amount of precipitated carbonate, whereas in rabbits fed a low-alkali diet, both pH(u) and precipitate decreased considerably. During high-alkali feeding, application of NH4Cl likewise decreased pH(u), but arterial pH was still maintained with no indication of metabolic acidosis. During low-alkali feeding, a comparably small amount of added NH4Cl further lowered pH(u) and was accompanied by a significant systemic metabolic acidosis. We conclude that exhausted renal base-saving function by dietary alkali depletion is a prerequisite for growing susceptibility to NH4Cl-induced chronic metabolic acidosis in the herbivore rabbit.

  16. Acid-base titrations by stepwise addition of equal volumes of titrant with special reference to automatic titrations-II Theory of titration of mixtures of acids, polyprotic acids, acids in mixture with weak bases, and ampholytes.

    PubMed

    Pehrsson, L; Ingman, F; Johansson, S

    A general method for evaluating titration data for mixtures of acids and for acids in mixture with weak bases is presented. Procedures are given that do not require absolute [H]-data, i.e., relative [H]-data may be used. In most cases a very rough calibration of the electrode system is enough. Further, for simple systems, very approximate values of the stability constants are sufficient. As examples, the titration of the following are treated in some detail: a mixture of two acids, a diprotic acid, an acid in presence of its conjugate base, and an ampholyte.

  17. A new computational account of cognitive control over reinforcement-based decision-making: Modeling of a probabilistic learning task.

    PubMed

    Zendehrouh, Sareh

    2015-11-01

    Recent work on decision-making field offers an account of dual-system theory for decision-making process. This theory holds that this process is conducted by two main controllers: a goal-directed system and a habitual system. In the reinforcement learning (RL) domain, the habitual behaviors are connected with model-free methods, in which appropriate actions are learned through trial-and-error experiences. However, goal-directed behaviors are associated with model-based methods of RL, in which actions are selected using a model of the environment. Studies on cognitive control also suggest that during processes like decision-making, some cortical and subcortical structures work in concert to monitor the consequences of decisions and to adjust control according to current task demands. Here a computational model is presented based on dual system theory and cognitive control perspective of decision-making. The proposed model is used to simulate human performance on a variant of probabilistic learning task. The basic proposal is that the brain implements a dual controller, while an accompanying monitoring system detects some kinds of conflict including a hypothetical cost-conflict one. The simulation results address existing theories about two event-related potentials, namely error related negativity (ERN) and feedback related negativity (FRN), and explore the best account of them. Based on the results, some testable predictions are also presented.

  18. An Individual-Based Model of Zebrafish Population Dynamics Accounting for Energy Dynamics

    PubMed Central

    Beaudouin, Rémy; Goussen, Benoit; Piccini, Benjamin; Augustine, Starrlight; Devillers, James; Brion, François; Péry, Alexandre R. R.

    2015-01-01

    Developing population dynamics models for zebrafish is crucial in order to extrapolate from toxicity data measured at the organism level to biological levels relevant to support and enhance ecological risk assessment. To achieve this, a dynamic energy budget for individual zebrafish (DEB model) was coupled to an individual based model of zebrafish population dynamics (IBM model). Next, we fitted the DEB model to new experimental data on zebrafish growth and reproduction thus improving existing models. We further analysed the DEB-model and DEB-IBM using a sensitivity analysis. Finally, the predictions of the DEB-IBM were compared to existing observations on natural zebrafish populations and the predicted population dynamics are realistic. While our zebrafish DEB-IBM model can still be improved by acquiring new experimental data on the most uncertain processes (e.g. survival or feeding), it can already serve to predict the impact of compounds at the population level. PMID:25938409

  19. Beyond simple models of self-control to circuit-based accounts of adolescent behavior.

    PubMed

    Casey, B J

    2015-01-03

    Adolescence is the transition from childhood to adulthood that begins around the onset of puberty and ends with relative independence from the parent. This developmental period is one when an individual is probably stronger, of higher reasoning capacity, and more resistant to disease than ever before, yet when mortality rates increase by 200%. These untimely deaths are not due to disease but to preventable deaths associated with adolescents putting themselves in harm's way (e.g., accidental fatalities). We present evidence that these alarming health statistics are in part due to diminished self-control--the ability to inhibit inappropriate desires, emotions, and actions in favor of appropriate ones. Findings of adolescent-specific changes in self-control and underlying brain circuitry are considered in terms of how evolutionarily based biological constraints and experiences shape the brain to adapt to the unique intellectual, physical, sexual, and social challenges of adolescence.

  20. Accounting for Proof Test Data in a Reliability Based Design Optimization Framework

    NASA Technical Reports Server (NTRS)

    Ventor, Gerharad; Scotti, Stephen J.

    2012-01-01

    This paper investigates the use of proof (or acceptance) test data during the reliability based design optimization of structural components. It is assumed that every component will be proof tested and that the component will only enter into service if it passes the proof test. The goal is to reduce the component weight, while maintaining high reliability, by exploiting the proof test results during the design process. The proposed procedure results in the simultaneous design of the structural component and the proof test itself and provides the designer with direct control over the probability of failing the proof test. The procedure is illustrated using two analytical example problems and the results indicate that significant weight savings are possible when exploiting the proof test results during the design process.

  1. Hard and soft acids and bases: structure and process.

    PubMed

    Reed, James L

    2012-07-05

    Under investigation is the structure and process that gives rise to hard-soft behavior in simple anionic atomic bases. That for simple atomic bases the chemical hardness is expected to be the only extrinsic component of acid-base strength, has been substantiated in the current study. A thermochemically based operational scale of chemical hardness was used to identify the structure within anionic atomic bases that is responsible for chemical hardness. The base's responding electrons have been identified as the structure, and the relaxation that occurs during charge transfer has been identified as the process giving rise to hard-soft behavior. This is in contrast the commonly accepted explanations that attribute hard-soft behavior to varying degrees of electrostatic and covalent contributions to the acid-base interaction. The ability of the atomic ion's responding electrons to cause hard-soft behavior has been assessed by examining the correlation of the estimated relaxation energies of the responding electrons with the operational chemical hardness. It has been demonstrated that the responding electrons are able to give rise to hard-soft behavior in simple anionic bases.

  2. Bio-based production of organic acids with Corynebacterium glutamicum.

    PubMed

    Wieschalka, Stefan; Blombach, Bastian; Bott, Michael; Eikmanns, Bernhard J

    2013-03-01

    The shortage of oil resources, the steadily rising oil prices and the impact of its use on the environment evokes an increasing political, industrial and technical interest for development of safe and efficient processes for the production of chemicals from renewable biomass. Thus, microbial fermentation of renewable feedstocks found its way in white biotechnology, complementing more and more traditional crude oil-based chemical processes. Rational strain design of appropriate microorganisms has become possible due to steadily increasing knowledge on metabolism and pathway regulation of industrially relevant organisms and, aside from process engineering and optimization, has an outstanding impact on improving the performance of such hosts. Corynebacterium glutamicum is well known as workhorse for the industrial production of numerous amino acids. However, recent studies also explored the usefulness of this organism for the production of several organic acids and great efforts have been made for improvement of the performance. This review summarizes the current knowledge and recent achievements on metabolic engineering approaches to tailor C. glutamicum for the bio-based production of organic acids. We focus here on the fermentative production of pyruvate, L- and D-lactate, 2-ketoisovalerate, 2-ketoglutarate, and succinate. These organic acids represent a class of compounds with manifold application ranges, e.g. in pharmaceutical and cosmetics industry, as food additives, and economically very interesting, as precursors for a variety of bulk chemicals and commercially important polymers.

  3. Acid-Base Balance in Uremic Rats with Vascular Calcification

    PubMed Central

    Peralta-Ramírez, Alan; Raya, Ana Isabel; Pineda, Carmen; Rodríguez, Mariano; Aguilera-Tejero, Escolástico; López, Ignacio

    2014-01-01

    Background/Aims Vascular calcification (VC), a major complication in humans and animals with chronic kidney disease (CKD), is influenced by changes in acid-base balance. The purpose of this study was to describe the acid-base balance in uremic rats with VC and to correlate the parameters that define acid-base equilibrium with VC. Methods Twenty-two rats with CKD induced by 5/6 nephrectomy (5/6 Nx) and 10 nonuremic control rats were studied. Results The 5/6 Nx rats showed extensive VC as evidenced by a high aortic calcium (9.2 ± 1.7 mg/g of tissue) and phosphorus (20.6 ± 4.9 mg/g of tissue) content. Uremic rats had an increased pH level (7.57 ± 0.03) as a consequence of both respiratory (PaCO2 = 28.4 ± 2.1 mm Hg) and, to a lesser degree, metabolic (base excess = 4.1 ± 1 mmol/l) derangements. A high positive correlation between both anion gap (AG) and strong ion difference (SID) with aortic calcium (AG: r = 0.604, p = 0.02; SID: r = 0.647, p = 0.01) and with aortic phosphorus (AG: r = 0.684, p = 0.007; SID: r = 0.785, p = 0.01) was detected. Conclusions In an experimental model of uremic rats, VC showed high positive correlation with AG and SID. PMID:25177336

  4. Developing nucleic acid-based electrical detection systems

    PubMed Central

    Gabig-Ciminska, Magdalena

    2006-01-01

    Development of nucleic acid-based detection systems is the main focus of many research groups and high technology companies. The enormous work done in this field is particularly due to the broad versatility and variety of these sensing devices. From optical to electrical systems, from label-dependent to label-free approaches, from single to multi-analyte and array formats, this wide range of possibilities makes the research field very diversified and competitive. New challenges and requirements for an ideal detector suitable for nucleic acid analysis include high sensitivity and high specificity protocol that can be completed in a relatively short time offering at the same time low detection limit. Moreover, systems that can be miniaturized and automated present a significant advantage over conventional technology, especially if detection is needed in the field. Electrical system technology for nucleic acid-based detection is an enabling mode for making miniaturized to micro- and nanometer scale bio-monitoring devices via the fusion of modern micro- and nanofabrication technology and molecular biotechnology. The electrical biosensors that rely on the conversion of the Watson-Crick base-pair recognition event into a useful electrical signal are advancing rapidly, and recently are receiving much attention as a valuable tool for microbial pathogen detection. Pathogens may pose a serious threat to humans, animal and plants, thus their detection and analysis is a significant element of public health. Although different conventional methods for detection of pathogenic microorganisms and their toxins exist and are currently being applied, improvements of molecular-based detection methodologies have changed these traditional detection techniques and introduced a new era of rapid, miniaturized and automated electrical chip detection technologies into pathogen identification sector. In this review some developments and current directions in nucleic acid-based electrical

  5. Accounting for phase drifts in SSVEP-based BCIs by means of biphasic stimulation.

    PubMed

    Wu, Hung-Yi; Lee, Po-Lei; Chang, Hsiang-Chih; Hsieh, Jen-Chuen

    2011-05-01

    This study proposes a novel biphasic stimulation technique to solve the issue of phase drifts in steady-state visual evoked potential (SSVEPs) in phase-tagged systems. Phase calibration was embedded in stimulus sequences using a biphasic flicker, which is driven by a sequence with alternating reference and phase-shift states. Nine subjects were recruited to participate in off-line and online tests. Signals were bandpass filtered and segmented by trigger signals into reference and phase-shift epochs. Frequency components of SSVEP in the reference and phase-shift epochs were extracted using the Fourier method with a 50% overlapped sliding window. The real and imaginary parts of the SSVEP frequency components were organized into complex vectors in each epoch. Hotelling's t-square test was used to determine the significances of nonzero mean vectors. The rejection of noisy data segments and the validation of gaze detections were made based on p values. The phase difference between the valid mean vectors of reference and phase-shift epochs was used to identify user's gazed targets in this system. Data showed an average information transfer rate of 44.55 and 38.21 bits/min in off-line and online tests, respectively.

  6. Accounting for ecosystem services in Life Cycle Assessment, Part II: toward an ecologically based LCA.

    PubMed

    Zhang, Yi; Baral, Anil; Bakshi, Bhavik R

    2010-04-01

    Despite the essential role of ecosystem goods and services in sustaining all human activities, they are often ignored in engineering decision making, even in methods that are meant to encourage sustainability. For example, conventional Life Cycle Assessment focuses on the impact of emissions and consumption of some resources. While aggregation and interpretation methods are quite advanced for emissions, similar methods for resources have been lagging, and most ignore the role of nature. Such oversight may even result in perverse decisions that encourage reliance on deteriorating ecosystem services. This article presents a step toward including the direct and indirect role of ecosystems in LCA, and a hierarchical scheme to interpret their contribution. The resulting Ecologically Based LCA (Eco-LCA) includes a large number of provisioning, regulating, and supporting ecosystem services as inputs to a life cycle model at the process or economy scale. These resources are represented in diverse physical units and may be compared via their mass, fuel value, industrial cumulative exergy consumption, or ecological cumulative exergy consumption or by normalization with total consumption of each resource or their availability. Such results at a fine scale provide insight about relative resource use and the risk and vulnerability to the loss of specific resources. Aggregate indicators are also defined to obtain indices such as renewability, efficiency, and return on investment. An Eco-LCA model of the 1997 economy is developed and made available via the web (www.resilience.osu.edu/ecolca). An illustrative example comparing paper and plastic cups provides insight into the features of the proposed approach. The need for further work in bridging the gap between knowledge about ecosystem services and their direct and indirect role in supporting human activities is discussed as an important area for future work.

  7. Acid and base stress and transcriptomic responses in Bacillus subtilis.

    PubMed

    Wilks, Jessica C; Kitko, Ryan D; Cleeton, Sarah H; Lee, Grace E; Ugwu, Chinagozi S; Jones, Brian D; BonDurant, Sandra S; Slonczewski, Joan L

    2009-02-01

    Acid and base environmental stress responses were investigated in Bacillus subtilis. B. subtilis AG174 cultures in buffered potassium-modified Luria broth were switched from pH 8.5 to pH 6.0 and recovered growth rapidly, whereas cultures switched from pH 6.0 to pH 8.5 showed a long lag time. Log-phase cultures at pH 6.0 survived 60 to 100% at pH 4.5, whereas cells grown at pH 7.0 survived <15%. Cells grown at pH 9.0 survived 40 to 100% at pH 10, whereas cells grown at pH 7.0 survived <5%. Thus, growth in a moderate acid or base induced adaptation to a more extreme acid or base, respectively. Expression indices from Affymetrix chip hybridization were obtained for 4,095 protein-encoding open reading frames of B. subtilis grown at external pH 6, pH 7, and pH 9. Growth at pH 6 upregulated acetoin production (alsDS), dehydrogenases (adhA, ald, fdhD, and gabD), and decarboxylases (psd and speA). Acid upregulated malate metabolism (maeN), metal export (czcDO and cadA), oxidative stress (catalase katA; OYE family namA), and the SigX extracytoplasmic stress regulon. Growth at pH 9 upregulated arginine catabolism (roc), which generates organic acids, glutamate synthase (gltAB), polyamine acetylation and transport (blt), the K(+)/H(+) antiporter (yhaTU), and cytochrome oxidoreductases (cyd, ctaACE, and qcrC). The SigH, SigL, and SigW regulons were upregulated at high pH. Overall, greater genetic adaptation was seen at pH 9 than at pH 6, which may explain the lag time required for growth shift to high pH. Low external pH favored dehydrogenases and decarboxylases that may consume acids and generate basic amines, whereas high external pH favored catabolism-generating acids.

  8. Acid-base properties of bentonite rocks with different origins.

    PubMed

    Nagy, Noémi M; Kónya, József

    2006-03-01

    Five bentonite samples (35-47% montmorillonite) from a Sarmatian sediment series with bentonite sites around Sajóbábony (Hungary) is studied. Some of these samples were tuffogenic bentonite (sedimentary), the others were bentonitized tuff with volcano sedimentary origin. The acid-base properties of the edge sites were studied by potentiometric titrations and surface complexation modeling. It was found that the number and the ratio of silanol and aluminol sites as well as the intrinsic stability constants are different for the sedimentary bentonite and bentonitized tuff. The characteristic properties of the edges sites depend on the origins. The acid-base properties are compared to other commercial and standard bentonites.

  9. Synthesis and characterization of copolyanhydrides of carbohydrate-based galactaric acid and adipic acid.

    PubMed

    Mehtiö, Tuomas; Nurmi, Leena; Rämö, Virpi; Mikkonen, Hannu; Harlin, Ali

    2015-01-30

    A series of copolyanhydrides, consisting of 2,3,4,5-tetra-O-acetylgalactaric acid (AGA) and adipic acid (AA) as monomer units, was polymerized. Synthesis of AGA monomer consisted of two steps. First, O-acetylation of galactaric acid secondary hydroxyl groups was performed using acetic anhydride as a reagent. Acetic anhydride was then further used as a reagent in the synthesis of diacetyl mixed anhydride of AGA. Polymerizations were conducted as bulk condensation polymerization at 150 °C. Thermal properties of the copolymers varied depending on monomer composition. Increase in the AGA content had a clear increasing effect on the Tg. A similar increasing effect was observed in Tm. The degree of crystallinity decreased as AGA content increased. There was a slightly lowering tendency in the molecular weights of the obtained polymers when the AGA content in the polymerization mixtures increased. The described synthesis route shows that bio-based aldaric acid monomers are potential candidates for the adjustment of thermal properties of polyanhydrides.

  10. Acid-base thermochemistry of gaseous aliphatic α-aminoacids.

    PubMed

    Bouchoux, Guy; Huang, Sihua; Inda, Bhawani Singh

    2011-01-14

    Acid-base thermochemistry of isolated aliphatic amino acids (denoted AAA): glycine, alanine, valine, leucine, isoleucine and proline has been examined theoretically by quantum chemical computations at the G3MP2B3 level. Conformational analysis on neutral, protonated and deprotonated species has been used to identify the lowest energy conformers and to estimate the population of conformers expected to be present at thermal equilibrium at 298 K. Comparison of the G3MP2B3 theoretical proton affinities, PA, and ΔH(acid) with experimental results is shown to be correct if experimental thermochemistry is re-evaluated and adapted to the most recent acidity-basicity scales. From this point of view, a set of evaluated proton affinities of 887, 902, 915, 916, 919 and 941 kJ mol(-1), and a set of evaluated ΔH(acid) of 1433, 1430, 1423, 1423, 1422 and 1426 kJ mol(-1), is proposed for glycine, alanine, valine, leucine, isoleucine and proline, respectively. Correlations with structural parameters (Taft's σ(α) polarizability parameter and molecular size) suggest that polarizability of the side chain is the major origin of the increase in PA and decrease in ΔH(acid) along the homologous series glycine, alanine, valine and leucine/isoleucine. Heats of formation of gaseous species AAA, AAAH(+) and [AAA-H](-) were computed at the G3MP2B3 level. The present study provides previously unavailable Δ(f)H°(298) for the ionized species AAAH(+) and [AAA-H](-). Comparison with Benson's estimate, and correlation with molecular size, show that several experimental Δ(f)H°(298) values of neutral or gaseous AAA might be erroneous.

  11. [Injuries caused by acids and bases - emergency treatment].

    PubMed

    Reifferscheid, Florian; Stuhr, Markus; Kaiser, Guido; Freudenberg, Matthias; Kerner, Thoralf

    2014-06-01

    Emergency medical care for injuries caused by acids and bases is challenging for rescue services. They have to deal with operational safety, detection of the toxic agent, emergency medical care of the patient and handling of the rescue mission. Because of the rareness of such situations experience and routine are largely missing. This article highlights some basic points for the therapy and provides support for such rescue missions.

  12. Synthesis of bio-based methacrylic acid by decarboxylation of itaconic acid and citric acid catalyzed by solid transition-metal catalysts.

    PubMed

    Le Nôtre, Jérôme; Witte-van Dijk, Susan C M; van Haveren, Jacco; Scott, Elinor L; Sanders, Johan P M

    2014-09-01

    Methacrylic acid, an important monomer for the plastics industry, was obtained in high selectivity (up to 84%) by the decarboxylation of itaconic acid using heterogeneous catalysts based on Pd, Pt and Ru. The reaction takes place in water at 200-250 °C without any external added pressure, conditions significantly milder than those described previously for the same conversion with better yield and selectivity. A comprehensive study of the reaction parameters has been performed, and the isolation of methacrylic acid was achieved in 50% yield. The decarboxylation procedure is also applicable to citric acid, a more widely available bio-based feedstock, and leads to the production of methacrylic acid in one pot in 41% selectivity. Aconitic acid, the intermediate compound in the pathway from citric acid to itaconic acid was also used successfully as a substrate.

  13. The normal acid-base status of mice.

    PubMed

    Iversen, Nina K; Malte, Hans; Baatrup, Erik; Wang, Tobias

    2012-03-15

    Rodent models are commonly used for various physiological studies including acid-base regulation. Despite the widespread use of especially genetic modified mice, little attention have been made to characterise the normal acid-base status in these animals in order to reveal proper control values. Furthermore, several studies report blood gas values obtained in anaesthetised animals. We, therefore, decided to characterise blood CO(2) binding characteristic of mouse blood in vitro and to characterise normal acid-base status in conscious BALBc mice. In vitro CO(2) dissociation curves, performed on whole blood equilibrated to various PCO₂ levels in rotating tonometers, revealed a typical mammalian pK' (pK'=7.816-0.234 × pH (r=0.34)) and a non-bicarbonate buffer capacity (16.1 ± 2.6 slyke). To measure arterial acid-base status, small blood samples were taken from undisturbed mice with indwelling catheters in the carotid artery. In these animals, pH was 7.391 ± 0.026, plasma [HCO(3)(-)] 18.4 ± 0.83 mM, PCO₂ 30.3 ± 2.1 mm Hg and lactate concentration 4.6 ± 0.7 mM. Our study, therefore, shows that mice have an arterial pH that resembles other mammals, although arterial PCO₂ tends to be lower than in larger mammals. However, pH from arterial blood sampled from mice anaesthetised with isoflurane was significantly lower (pH 7.239 ± 0.021), while plasma [HCO(3)(-)] was 18.5 ± 1.4 mM, PCO₂ 41.9 ± 2.9 mm Hg and lactate concentration 4.48 ± 0.67 mM. Furthermore, we measured metabolism and ventilation (V(E)) in order to determine the ventilation requirements (VE/VO₂) to answer whether small mammals tend to hyperventilate. We recommend, therefore, that studies on acid-base regulation in mice should be based on samples taken for indwelling catheters rather than cardiac puncture of terminally anaesthetised mice.

  14. Lewis base activation of Lewis acids: development of a Lewis base catalyzed selenolactonization.

    PubMed

    Denmark, Scott E; Collins, William R

    2007-09-13

    The concept of Lewis base activation of Lewis acids has been applied to the selenolactonization reaction. Through the use of substoichiometric amounts of Lewis bases with "soft" donor atoms (S, Se, P) significant rate enhancements over the background reaction are seen. Preliminary mechanistic investigations have revealed the resting state of the catalyst as well as the significance of a weak Brønsted acid promoter.

  15. The effect of acid-base clustering and ions on the growth of atmospheric nano-particles

    NASA Astrophysics Data System (ADS)

    Lehtipalo, Katrianne; Rondo, Linda; Kontkanen, Jenni; Schobesberger, Siegfried; Jokinen, Tuija; Sarnela, Nina; Kürten, Andreas; Ehrhart, Sebastian; Franchin, Alessandro; Nieminen, Tuomo; Riccobono, Francesco; Sipilä, Mikko; Yli-Juuti, Taina; Duplissy, Jonathan; Adamov, Alexey; Ahlm, Lars; Almeida, João; Amorim, Antonio; Bianchi, Federico; Breitenlechner, Martin; Dommen, Josef; Downard, Andrew J.; Dunne, Eimear M.; Flagan, Richard C.; Guida, Roberto; Hakala, Jani; Hansel, Armin; Jud, Werner; Kangasluoma, Juha; Kerminen, Veli-Matti; Keskinen, Helmi; Kim, Jaeseok; Kirkby, Jasper; Kupc, Agnieszka; Kupiainen-Määttä, Oona; Laaksonen, Ari; Lawler, Michael J.; Leiminger, Markus; Mathot, Serge; Olenius, Tinja; Ortega, Ismael K.; Onnela, Antti; Petäjä, Tuukka; Praplan, Arnaud; Rissanen, Matti P.; Ruuskanen, Taina; Santos, Filipe D.; Schallhart, Simon; Schnitzhofer, Ralf; Simon, Mario; Smith, James N.; Tröstl, Jasmin; Tsagkogeorgas, Georgios; Tomé, António; Vaattovaara, Petri; Vehkamäki, Hanna; Vrtala, Aron E.; Wagner, Paul E.; Williamson, Christina; Wimmer, Daniela; Winkler, Paul M.; Virtanen, Annele; Donahue, Neil M.; Carslaw, Kenneth S.; Baltensperger, Urs; Riipinen, Ilona; Curtius, Joachim; Worsnop, Douglas R.; Kulmala, Markku

    2016-05-01

    The growth of freshly formed aerosol particles can be the bottleneck in their survival to cloud condensation nuclei. It is therefore crucial to understand how particles grow in the atmosphere. Insufficient experimental data has impeded a profound understanding of nano-particle growth under atmospheric conditions. Here we study nano-particle growth in the CLOUD (Cosmics Leaving OUtdoors Droplets) chamber, starting from the formation of molecular clusters. We present measured growth rates at sub-3 nm sizes with different atmospherically relevant concentrations of sulphuric acid, water, ammonia and dimethylamine. We find that atmospheric ions and small acid-base clusters, which are not generally accounted for in the measurement of sulphuric acid vapour, can participate in the growth process, leading to enhanced growth rates. The availability of compounds capable of stabilizing sulphuric acid clusters governs the magnitude of these effects and thus the exact growth mechanism. We bring these observations into a coherent framework and discuss their significance in the atmosphere.

  16. [Nutrition, acid-base metabolism, cation-anion difference and total base balance in humans].

    PubMed

    Mioni, R; Sala, P; Mioni, G

    2008-01-01

    The relationship between dietary intake and acid-base metabolism has been investigated in the past by means of the inorganic cation-anion difference (C(+)(nm)-A(-)(nm)) method based on dietary ash-acidity titration after the oxidative combustion of food samples. Besides the inorganic components of TA (A(-)(nm)-C(+)(nm)), which are under renal control, there are also metabolizable components (A(-)(nm)-C(+)(nm)) of TA, which are under the control of the intermediate metabolism. The whole body base balance, NBb(W), is obtained only by the application of C(+)(nm)-A(-)(nm) to food, feces and urine, while the metabolizable component (A(-)(nm)-C(+)(nm)) is disregarded. A novel method has been subsequently suggested to calculate the net balance of fixed acid, made up by the difference between the input of net endogenous acid production: NEAP = SO(4)(2-)+A(-)(m)-(C(+)(nm)-A(-)(nm)), and the output of net acid excretion: NAE = TA + NH(4)(+) - HCO(3)(-). This approach has been criticized because 1) it includes metabolizable acids, whose production cannot be measured independently; 2) the specific control of metabolizable acid and base has been incorrectly attributed to the kidney; 3) the inclusion of A-m in the balance input generates an acid overload; 4) the object of measurement in making up a balance has to be the same, a condition not fulfilled as NEAP is different from NAE. Lastly, by rearranging the net balance of the acid equation, the balance of nonmetabolizable acid equation is obtained. Therefore, any discrepancy between these two equations is due to the inaccuracy in the urine measurement of metabolizable cations and/or anions.

  17. Automated acid and base number determination of mineral-based lubricants by fourier transform infrared spectroscopy: commercial laboratory evaluation.

    PubMed

    Winterfield, Craig; van de Voort, F R

    2014-12-01

    The Fluid Life Corporation assessed and implemented Fourier transform infrared spectroscopy (FTIR)-based methods using American Society for Testing and Materials (ASTM)-like stoichiometric reactions for determination of acid and base number for in-service mineral-based oils. The basic protocols, quality control procedures, calibration, validation, and performance of these new quantitative methods are assessed. ASTM correspondence is attained using a mixed-mode calibration, using primary reference standards to anchor the calibration, supplemented by representative sample lubricants analyzed by ASTM procedures. A partial least squares calibration is devised by combining primary acid/base reference standards and representative samples, focusing on the main spectral stoichiometric response with chemometrics assisting in accounting for matrix variability. FTIR(AN/BN) methodology is precise, accurate, and free of most interference that affects ASTM D664 and D4739 results. Extensive side-by-side operational runs produced normally distributed differences with mean differences close to zero and standard deviations of 0.18 and 0.26 mg KOH/g, respectively. Statistically, the FTIR methods are a direct match to the ASTM methods, with superior performance in terms of analytical throughput, preparation time, and solvent use. FTIR(AN/BN) analysis is a viable, significant advance for in-service lubricant analysis, providing an economic means of trending samples instead of tedious and expensive conventional ASTM(AN/BN) procedures.

  18. Acid Base Equilibrium in a Lipid/Water Gel

    NASA Astrophysics Data System (ADS)

    Streb, Kristina K.; Ilich, Predrag-Peter

    2003-12-01

    A new and original experiment in which partition of bromophenol blue dye between water and lipid/water gel causes a shift in the acid base equilibrium of the dye is described. The dye-absorbing material is a monoglyceride food additive of plant origin that mixes freely with water to form a stable cubic phase gel; the nascent gel absorbs the dye from aqueous solution and converts it to the acidic form. There are three concurrent processes taking place in the experiment: (a) formation of the lipid/water gel, (b) absorption of the dye by the gel, and (c) protonation of the dye in the lipid/water gel environment. As the aqueous solution of the dye is a deep purple-blue color at neutral pH and yellow at acidic pH the result of these processes is visually striking: the strongly green-yellow particles of lipid/water gel are suspended in purple-blue aqueous solution. The local acidity of the lipid/water gel is estimated by UV vis spectrophotometry. This experiment is an example of host-guest (lipid/water gel dye) interaction and is suitable for project-type biophysics, physical chemistry, or biochemistry labs. The experiment requires three, 3-hour lab sessions, two of which must not be separated by more than two days.

  19. Acid-base chemistry of frustrated water at protein interfaces.

    PubMed

    Fernández, Ariel

    2016-01-01

    Water molecules at a protein interface are often frustrated in hydrogen-bonding opportunities due to subnanoscale confinement. As shown, this condition makes them behave as a general base that may titrate side-chain ammonium and guanidinium cations. Frustration-based chemistry is captured by a quantum mechanical treatment of proton transference and shown to remove same-charge uncompensated anticontacts at the interface found in the crystallographic record and in other spectroscopic information on the aqueous interface. Such observations are untenable within classical arguments, as hydronium is a stronger acid than ammonium or guanidinium. Frustration enables a directed Grotthuss mechanism for proton transference stabilizing same-charge anticontacts.

  20. Insight into acid-base nucleation experiments by comparison of the chemical composition of positive, negative, and neutral clusters.

    PubMed

    Bianchi, Federico; Praplan, Arnaud P; Sarnela, Nina; Dommen, Josef; Kürten, Andreas; Ortega, Ismael K; Schobesberger, Siegfried; Junninen, Heikki; Simon, Mario; Tröstl, Jasmin; Jokinen, Tuija; Sipilä, Mikko; Adamov, Alexey; Amorim, Antonio; Almeida, Joao; Breitenlechner, Martin; Duplissy, Jonathan; Ehrhart, Sebastian; Flagan, Richard C; Franchin, Alessandro; Hakala, Jani; Hansel, Armin; Heinritzi, Martin; Kangasluoma, Juha; Keskinen, Helmi; Kim, Jaeseok; Kirkby, Jasper; Laaksonen, Ari; Lawler, Michael J; Lehtipalo, Katrianne; Leiminger, Markus; Makhmutov, Vladimir; Mathot, Serge; Onnela, Antti; Petäjä, Tuukka; Riccobono, Francesco; Rissanen, Matti P; Rondo, Linda; Tomé, António; Virtanen, Annele; Viisanen, Yrjö; Williamson, Christina; Wimmer, Daniela; Winkler, Paul M; Ye, Penglin; Curtius, Joachim; Kulmala, Markku; Worsnop, Douglas R; Donahue, Neil M; Baltensperger, Urs

    2014-12-02

    We investigated the nucleation of sulfuric acid together with two bases (ammonia and dimethylamine), at the CLOUD chamber at CERN. The chemical composition of positive, negative, and neutral clusters was studied using three Atmospheric Pressure interface-Time Of Flight (APi-TOF) mass spectrometers: two were operated in positive and negative mode to detect the chamber ions, while the third was equipped with a nitrate ion chemical ionization source allowing detection of neutral clusters. Taking into account the possible fragmentation that can happen during the charging of the ions or within the first stage of the mass spectrometer, the cluster formation proceeded via essentially one-to-one acid-base addition for all of the clusters, independent of the type of the base. For the positive clusters, the charge is carried by one excess protonated base, while for the negative clusters it is carried by a deprotonated acid; the same is true for the neutral clusters after these have been ionized. During the experiments involving sulfuric acid and dimethylamine, it was possible to study the appearance time for all the clusters (positive, negative, and neutral). It appeared that, after the formation of the clusters containing three molecules of sulfuric acid, the clusters grow at a similar speed, independent of their charge. The growth rate is then probably limited by the arrival rate of sulfuric acid or cluster-cluster collision.

  1. Nutrition, acid-base status and growth in early childhood.

    PubMed

    Kalhoff, H; Manz, F

    2001-10-01

    Optimal growth is only possible in a well-balanced "inner milieu". Premature infants are especially vulnerable for disturbances of acid-base metabolism with a predisposition to metabolic acidosis due to a transient disproportion between age-related low renal capacity for net acid excretion (NAE) and an unphysiologically high actual renal NAE on nutrition with standard formulas. During a 50 month period, 452 low birth-weight infants were screened for spontaneous development of incipient late metabolic acidosis (ILMA), an early stage during the development of retention acidosis, characterized by maximum renal acid stimulation (MRAS, urine-pH < 5.4) on two consecutive days but still compensated systemic acid-base status. Compared with controls, patients with ILMA showed higher serum creatinine values, an increased urinary excretion of sodium, aldosterone and nitrogen, but only slightly lower blood pH (7.38 vs 7.41) and base excess (-2.8 vs. 0.2 mmol/l) with respiratory compensation (PCO2 35 vs 37 mm Hg). Patients with altogether 149 episodes of ILMA were subsequently randomly allocated to either treatment with NaHCO3 2 mmol/kg/d for 7 days or no special therapy in protocol I, or NaHCO3 vs NaCl each 2 mmol/kg/d for 7 days in protocol II. Patients of protocol I with persistent MRAS for 7 days showed lowest weight gain and a tendency for a further increase in urinary aldosterone and nitrogen excretion. NaCl supplementation (protocol II) seemed to promote weight gain without affecting either impaired mineralization or suboptimal nitrogen retention. Patients with alkali therapy under both protocols showed normal weight gain and normalization of hormonal stimulation, mineralization (protocol II) and nitrogen assimilation. Modification of the mineral content of a standard preterm formula decreased renal NAE to the low level seen on alimentation with human milk and reduced the incidence of ILMA in preterm and small-for-gestational-age infants to 1%. The data show that ILMA is

  2. Born energy, acid-base equilibrium, structure and interactions of end-grafted weak polyelectrolyte layers

    SciTech Connect

    Nap, R. J.; Tagliazucchi, M.; Szleifer, I.

    2014-01-14

    This work addresses the effect of the Born self-energy contribution in the modeling of the structural and thermodynamical properties of weak polyelectrolytes confined to planar and curved surfaces. The theoretical framework is based on a theory that explicitly includes the conformations, size, shape, and charge distribution of all molecular species and considers the acid-base equilibrium of the weak polyelectrolyte. Namely, the degree of charge in the polymers is not imposed but it is a local varying property that results from the minimization of the total free energy. Inclusion of the dielectric properties of the polyelectrolyte is important as the environment of a polymer layer is very different from that in the adjacent aqueous solution. The main effect of the Born energy contribution on the molecular organization of an end-grafted weak polyacid layer is uncharging the weak acid (or basic) groups and consequently decreasing the concentration of mobile ions within the layer. The magnitude of the effect increases with polymer density and, in the case of the average degree of charge, it is qualitatively equivalent to a small shift in the equilibrium constant for the acid-base equilibrium of the weak polyelectrolyte monomers. The degree of charge is established by the competition between electrostatic interactions, the polymer conformational entropy, the excluded volume interactions, the translational entropy of the counterions and the acid-base chemical equilibrium. Consideration of the Born energy introduces an additional energetic penalty to the presence of charged groups in the polyelectrolyte layer, whose effect is mitigated by down-regulating the amount of charge, i.e., by shifting the local-acid base equilibrium towards its uncharged state. Shifting of the local acid-base equilibrium and its effect on the properties of the polyelectrolyte layer, without considering the Born energy, have been theoretically predicted previously. Account of the Born energy leads

  3. Born energy, acid-base equilibrium, structure and interactions of end-grafted weak polyelectrolyte layers.

    PubMed

    Nap, R J; Tagliazucchi, M; Szleifer, I

    2014-01-14

    This work addresses the effect of the Born self-energy contribution in the modeling of the structural and thermodynamical properties of weak polyelectrolytes confined to planar and curved surfaces. The theoretical framework is based on a theory that explicitly includes the conformations, size, shape, and charge distribution of all molecular species and considers the acid-base equilibrium of the weak polyelectrolyte. Namely, the degree of charge in the polymers is not imposed but it is a local varying property that results from the minimization of the total free energy. Inclusion of the dielectric properties of the polyelectrolyte is important as the environment of a polymer layer is very different from that in the adjacent aqueous solution. The main effect of the Born energy contribution on the molecular organization of an end-grafted weak polyacid layer is uncharging the weak acid (or basic) groups and consequently decreasing the concentration of mobile ions within the layer. The magnitude of the effect increases with polymer density and, in the case of the average degree of charge, it is qualitatively equivalent to a small shift in the equilibrium constant for the acid-base equilibrium of the weak polyelectrolyte monomers. The degree of charge is established by the competition between electrostatic interactions, the polymer conformational entropy, the excluded volume interactions, the translational entropy of the counterions and the acid-base chemical equilibrium. Consideration of the Born energy introduces an additional energetic penalty to the presence of charged groups in the polyelectrolyte layer, whose effect is mitigated by down-regulating the amount of charge, i.e., by shifting the local-acid base equilibrium towards its uncharged state. Shifting of the local acid-base equilibrium and its effect on the properties of the polyelectrolyte layer, without considering the Born energy, have been theoretically predicted previously. Account of the Born energy leads

  4. An agent-based simulation model of patient choice of health care providers in accountable care organizations.

    PubMed

    Alibrahim, Abdullah; Wu, Shinyi

    2016-10-04

    Accountable care organizations (ACO) in the United States show promise in controlling health care costs while preserving patients' choice of providers. Understanding the effects of patient choice is critical in novel payment and delivery models like ACO that depend on continuity of care and accountability. The financial, utilization, and behavioral implications associated with a patient's decision to forego local health care providers for more distant ones to access higher quality care remain unknown. To study this question, we used an agent-based simulation model of a health care market composed of providers able to form ACO serving patients and embedded it in a conditional logit decision model to examine patients capable of choosing their care providers. This simulation focuses on Medicare beneficiaries and their congestive heart failure (CHF) outcomes. We place the patient agents in an ACO delivery system model in which provider agents decide if they remain in an ACO and perform a quality improving CHF disease management intervention. Illustrative results show that allowing patients to choose their providers reduces the yearly payment per CHF patient by $320, reduces mortality rates by 0.12 percentage points and hospitalization rates by 0.44 percentage points, and marginally increases provider participation in ACO. This study demonstrates a model capable of quantifying the effects of patient choice in a theoretical ACO system and provides a potential tool for policymakers to understand implications of patient choice and assess potential policy controls.

  5. Dependency Resolution Difficulty Increases with Distance in Persian Separable Complex Predicates: Evidence for Expectation and Memory-Based Accounts.

    PubMed

    Safavi, Molood S; Husain, Samar; Vasishth, Shravan

    2016-01-01

    Delaying the appearance of a verb in a noun-verb dependency tends to increase processing difficulty at the verb; one explanation for this locality effect is decay and/or interference of the noun in working memory. Surprisal, an expectation-based account, predicts that delaying the appearance of a verb either renders it no more predictable or more predictable, leading respectively to a prediction of no effect of distance or a facilitation. Recently, Husain et al. (2014) suggested that when the exact identity of the upcoming verb is predictable (strong predictability), increasing argument-verb distance leads to facilitation effects, which is consistent with surprisal; but when the exact identity of the upcoming verb is not predictable (weak predictability), locality effects are seen. We investigated Husain et al.'s proposal using Persian complex predicates (CPs), which consist of a non-verbal element-a noun in the current study-and a verb. In CPs, once the noun has been read, the exact identity of the verb is highly predictable (strong predictability); this was confirmed using a sentence completion study. In two self-paced reading (SPR) and two eye-tracking (ET) experiments, we delayed the appearance of the verb by interposing a relative clause (Experiments 1 and 3) or a long PP (Experiments 2 and 4). We also included a simple Noun-Verb predicate configuration with the same distance manipulation; here, the exact identity of the verb was not predictable (weak predictability). Thus, the design crossed Predictability Strength and Distance. We found that, consistent with surprisal, the verb in the strong predictability conditions was read faster than in the weak predictability conditions. Furthermore, greater verb-argument distance led to slower reading times; strong predictability did not neutralize or attenuate the locality effects. As regards the effect of distance on dependency resolution difficulty, these four experiments present evidence in favor of working memory

  6. Dependency Resolution Difficulty Increases with Distance in Persian Separable Complex Predicates: Evidence for Expectation and Memory-Based Accounts

    PubMed Central

    Safavi, Molood S.; Husain, Samar; Vasishth, Shravan

    2016-01-01

    Delaying the appearance of a verb in a noun-verb dependency tends to increase processing difficulty at the verb; one explanation for this locality effect is decay and/or interference of the noun in working memory. Surprisal, an expectation-based account, predicts that delaying the appearance of a verb either renders it no more predictable or more predictable, leading respectively to a prediction of no effect of distance or a facilitation. Recently, Husain et al. (2014) suggested that when the exact identity of the upcoming verb is predictable (strong predictability), increasing argument-verb distance leads to facilitation effects, which is consistent with surprisal; but when the exact identity of the upcoming verb is not predictable (weak predictability), locality effects are seen. We investigated Husain et al.'s proposal using Persian complex predicates (CPs), which consist of a non-verbal element—a noun in the current study—and a verb. In CPs, once the noun has been read, the exact identity of the verb is highly predictable (strong predictability); this was confirmed using a sentence completion study. In two self-paced reading (SPR) and two eye-tracking (ET) experiments, we delayed the appearance of the verb by interposing a relative clause (Experiments 1 and 3) or a long PP (Experiments 2 and 4). We also included a simple Noun-Verb predicate configuration with the same distance manipulation; here, the exact identity of the verb was not predictable (weak predictability). Thus, the design crossed Predictability Strength and Distance. We found that, consistent with surprisal, the verb in the strong predictability conditions was read faster than in the weak predictability conditions. Furthermore, greater verb-argument distance led to slower reading times; strong predictability did not neutralize or attenuate the locality effects. As regards the effect of distance on dependency resolution difficulty, these four experiments present evidence in favor of working

  7. A Comparative Study of the Effect of Web-Based versus In-Class Textbook Ethics Instruction on Accounting Students' Propensity to Whistle-Blow

    ERIC Educational Resources Information Center

    McManus, Lisa; Subramaniam, Nava; James, Wendy

    2012-01-01

    The authors examined whether accounting students' propensity to whistle-blow differed between those instructed through a web-based teaching module and those exposed to a traditional in-class textbook-focused approach. A total of 156 students from a second-year financial accounting course participated in the study. Ninety students utilized the…

  8. Accounting Specialist.

    ERIC Educational Resources Information Center

    Ohio State Univ., Columbus. Center on Education and Training for Employment.

    This publication identifies 20 subjects appropriate for use in a competency list for the occupation of accounting specialist, 1 of 12 occupations within the business/computer technologies cluster. Each unit consists of a number of competencies; a list of competency builders is provided for each competency. Titles of the 20 units are as follows:…

  9. Painless Accountability.

    ERIC Educational Resources Information Center

    Brown, R. W.; And Others

    The computerized Painless Accountability System is a performance objective system from which instructional programs are developed. Three main simplified behavioral response levels characterize this system: (1) cognitive, (2) psychomotor, and (3) affective domains. Each of these objectives are classified by one of 16 descriptors. The second major…

  10. Accountability Overboard

    ERIC Educational Resources Information Center

    Chieppo, Charles D.; Gass, James T.

    2009-01-01

    This article reports that special interest groups opposed to charter schools and high-stakes testing have hijacked Massachusetts's once-independent board of education and stand poised to water down the Massachusetts Comprehensive Assessment System (MCAS) tests and the accountability system they support. President Barack Obama and Massachusetts…

  11. Acid-base catalysis of N-[(morpholine)methylene]daunorubicin.

    PubMed

    Krause, Anna; Jelińska, Anna; Cielecka-Piontek, Judyta; Klawitter, Maria; Zalewski, Przemysław; Oszczapowicz, Irena; Wąsowska, Małgorzata

    2012-08-01

    The stability of N-[(morpholine)methylene]-daunorubicin hydrochloride (MMD) was investigated in the pH range 0.44-13.54, at 313, 308, 303 and 298 K. The degradation of MMD as a result of hydrolysis is a pseudo-first-order reaction described by the following equation: ln c = ln c(0) - k(obs)• t. In the solutions of hydrochloric acid, sodium hydroxide, borate, acetate and phosphate buffers, k(obs) = k(pH) because general acid-base catalysis was not observed. Specific acid-base catalysis of MMD comprises the following reactions: hydrolysis of the protonated molecules of MMD catalyzed by hydrogen ions (k(1)) and spontaneous hydrolysis of MMD molecules other than the protonated ones (k(2)) under the influence of water. The total rate of the reaction is equal to the sum of partial reactions: k(pH) = k(1) • a(H)+ • f(1) + k(2) • f(2) where: k(1) is the second-order rate constant (mol(-1) l s(-1)) of the specific hydrogen ion-catalyzed degradation of the protonated molecules of MMD; k(2) is the pseudo-first-order rate constant (s(-1)) of the water-catalyzed degradation of MMD molecules other than the protonated ones, f(1) - f(2) are fractions of the compound. MMD is the most stable at approx. pH 2.5.

  12. A microarray-based method to perform nucleic acid selections.

    PubMed

    Aminova, Olga; Disney, Matthew D

    2010-01-01

    This method describes a microarray-based platform to perform nucleic acid selections. Chemical ligands to which a nucleic acid binder is desired are immobilized onto an agarose microarray surface; the array is then incubated with an RNA library. Bound RNA library members are harvested directly from the array surface via gel excision at the position on the array where a ligand was immobilized. The RNA is then amplified via RT-PCR, cloned, and sequenced. This method has the following advantages over traditional resin-based Systematic Evolution of Ligands by Exponential Enrichment (SELEX): (1) multiple selections can be completed in parallel on a single microarray surface; (2) kinetic biases in the selections are mitigated since all RNA binders are harvested from an array via gel excision; (3) the amount of chemical ligand needed to perform a selection is minimized; (4) selections do not require expensive resins or equipment; and (5) the matrix used for selections is inexpensive and easy to prepare. Although this protocol was demonstrated for RNA selections, it should be applicable for any nucleic acid selection.

  13. Age estimation based on aspartic acid racemization in human sclera.

    PubMed

    Klumb, Karolin; Matzenauer, Christian; Reckert, Alexandra; Lehmann, Klaus; Ritz-Timme, Stefanie

    2016-01-01

    Age estimation based on racemization of aspartic acid residues (AAR) in permanent proteins has been established in forensic medicine for years. While dentine is the tissue of choice for this molecular method of age estimation, teeth are not always available which leads to the need to identify other suitable tissues. We examined the suitability of total tissue samples of human sclera for the estimation of age at death. Sixty-five samples of scleral tissue were analyzed. The samples were hydrolyzed and after derivatization, the extent of aspartic acid racemization was determined by gas chromatography. The degree of AAR increased with age. In samples from younger individuals, the correlation of age and D-aspartic acid content was closer than in samples from older individuals. The age-dependent racemization in total tissue samples proves that permanent or at least long-living proteins are present in scleral tissue. The correlation of AAR in human sclera and age at death is close enough to serve as basis for age estimation. However, the precision of age estimation by this method is lower than that of age estimation based on the analysis of dentine which is due to molecular inhomogeneities of total tissue samples of sclera. Nevertheless, the approach may serve as a valuable alternative or addition in exceptional cases.

  14. How Do Undergraduate Students Conceptualize Acid-Base Chemistry? Measurement of a Concept Progression

    ERIC Educational Resources Information Center

    Romine, William L.; Todd, Amber N.; Clark, Travis B.

    2016-01-01

    We developed and validated a new instrument, called "Measuring Concept progressions in Acid-Base chemistry" (MCAB) and used it to better understand the progression of undergraduate students' understandings about acid-base chemistry. Items were developed based on an existing learning progression for acid-base chemistry. We used the Rasch…

  15. Would GAAP - Based Accounting Practices Improve Financial Management and Decision-Making in the Department of Defense?

    DTIC Science & Technology

    1990-08-01

    Accounting Procedures Act of 1950 and the FMFIA are carried out are OMB Circular A- 123 , Internal Control Systems,65 and OMB Circular A- 127, Financial...Office. Standards For Internal Controls In The Federal Government, Accounting Series, 1983. 65 U. S. Office of Management and Budget. OMB Circular A- 123 ...defined by FASB 125 for the 123 Young, Ronald S., Director, Accounting Principles and Standards Group, Accounting and Financial Management Division, U. S

  16. Urea biosensors based on PVC membrane containing palmitic acid.

    PubMed

    Karakuş, Emine; Pekyardimci, Sule; Esma, Kiliç

    2005-01-01

    A new urea biosensor was prepared by immobilizing urease with four different procedures on poly(vinylchloride) (PVC) ammonium membrane electrode containing palmitic acid by using nonactine as an ammonium-ionophore. The analytical characteristics were investigated and were compared those of the biosensor prepared by using carboxylated PVC. The effect of pH, buffer concentration, temperature, urease concentration, stirring rate and enzyme immobilization procedures on the response to urea of the enzyme electrode were investigated. The linear working range and sensitivity of the biosensor were also determined. The urea biosensor prepared by using the PVC membranes containing palmitic acid showed more effective performance than those of the carboxylated PVC based biosensors. Additionally, urea assay in serum was successfully carried out by using the standard addition method.

  17. Reaction mechanisms of riboflavin triplet state with nucleic acid bases.

    PubMed

    Lin, Weizhen; Lu, Changyuan; Du, Fuqiang; Shao, Zhiyong; Han, Zhenhui; Tu, Tiecheng; Yao, Side; Lin, Nianyun

    2006-04-01

    ESR and laser flash photolysis studies have determined a reasonable order of reactivity of nucleotides with triplet riboflavin (3Rb*) for the first time. ESR detection of triplet state reactivity of Rb with nucleoside, polynucleotide and DNA has been obtained simultaneously. In addition, ESR spin elimination measurement of the reactivity of 3Rb* with nucleotides in good accord with laser flash photolysis determination of the corresponding rate constants offers a simple and reliable method to detect the reactivities of nucleic acids and its components with photoexcited flavins. Kinetic, ESR and thermodynamic studies have demonstrated that Rb should be a strong endogenous photosensitizer capable of oxidizing all nucleic acid bases, and preferentially two purine nucleotides with high rate constants.

  18. Bio-based production of organic acids with Corynebacterium glutamicum

    PubMed Central

    Wieschalka, Stefan; Blombach, Bastian; Bott, Michael; Eikmanns, Bernhard J

    2013-01-01

    The shortage of oil resources, the steadily rising oil prices and the impact of its use on the environment evokes an increasing political, industrial and technical interest for development of safe and efficient processes for the production of chemicals from renewable biomass. Thus, microbial fermentation of renewable feedstocks found its way in white biotechnology, complementing more and more traditional crude oil-based chemical processes. Rational strain design of appropriate microorganisms has become possible due to steadily increasing knowledge on metabolism and pathway regulation of industrially relevant organisms and, aside from process engineering and optimization, has an outstanding impact on improving the performance of such hosts. Corynebacterium glutamicum is well known as workhorse for the industrial production of numerous amino acids. However, recent studies also explored the usefulness of this organism for the production of several organic acids and great efforts have been made for improvement of the performance. This review summarizes the current knowledge and recent achievements on metabolic engineering approaches to tailor C. glutamicum for the bio-based production of organic acids. We focus here on the fermentative production of pyruvate, l-and d-lactate, 2-ketoisovalerate, 2-ketoglutarate, and succinate. These organic acids represent a class of compounds with manifold application ranges, e.g. in pharmaceutical and cosmetics industry, as food additives, and economically very interesting, as precursors for a variety of bulk chemicals and commercially important polymers. Funding Information Work in the laboratories of the authors was supported by the Fachagentur Nachwachsende Rohstoffe (FNR) of the Bundesministerium für Ernährung, Landwirtschaft und Verbraucherschutz (BMELV; FNR Grants 220-095-08A and 220-095-08D; Bio-ProChemBB project, ERA-IB programme), by the Deutsche Bundesstiftung Umwelt (DBU Grant AZ13040/05) and the Evonik Degussa AG. PMID

  19. Superabsorbent biphasic system based on poly(lactic acid) and poly(acrylic acid)

    NASA Astrophysics Data System (ADS)

    Sartore, Luciana; Pandini, Stefano; Baldi, Francesco; Bignotti, Fabio

    2016-05-01

    In this research work, biocomposites based on crosslinked particles of poly(acrylic acid), commonly used as superabsorbent polymer (SAP), and poly-L-lactic acid (PLLA) were developed to elucidate the role of the filler (i.e., polymeric crosslinked particles) on the overall physico-mechanical behavior and to obtain superabsorbent thermoplastic products. Samples prepared by melt-blending of components in different ratios showed a biphasic system with a regular distribution of particles, with diameter ranging from 5 to 10 μm, within the PLLA polymeric matrix. The polymeric biphasic system, coded PLASA i.e. superabsorbent poly(lactic acid), showed excellent swelling properties, demonstrating that cross-linked particles retain their superabsorbent ability, as in their free counterparts, even if distributed in a thermoplastic polymeric matrix. The thermal characteristics of the biocomposites evidence enhanced thermal stability in comparison with neat PLLA and also mechanical properties are markedly modified by addition of crosslinked particles which induce regular stiffening effect. Furthermore, in aqueous environments the particles swell and are leached from PLLA matrix generating very high porosity. These new open-pore PLLA foams, produced in absence of organic solvents and chemical foaming agents, with good physico-mechanical properties appear very promising for several applications, for instance in tissue engineering for scaffold production.

  20. Accounting for selection bias in species distribution models: An econometric approach on forested trees based on structural modeling

    NASA Astrophysics Data System (ADS)

    Ay, Jean-Sauveur; Guillemot, Joannès; Martin-StPaul, Nicolas K.; Doyen, Luc; Leadley, Paul

    2015-04-01

    Species distribution models (SDMs) are widely used to study and predict the outcome of global change on species. In human dominated ecosystems the presence of a given species is the result of both its ecological suitability and human footprint on nature such as land use choices. Land use choices may thus be responsible for a selection bias in the presence/absence data used in SDM calibration. We present a structural modelling approach (i.e. based on structural equation modelling) that accounts for this selection bias. The new structural species distribution model (SSDM) estimates simultaneously land use choices and species responses to bioclimatic variables. A land use equation based on an econometric model of landowner choices was joined to an equation of species response to bioclimatic variables. SSDM allows the residuals of both equations to be dependent, taking into account the possibility of shared omitted variables and measurement errors. We provide a general description of the statistical theory and a set of application on forested trees over France using databases of climate and forest inventory at different spatial resolution (from 2km to 8 km). We also compared the output of the SSDM with outputs of a classical SDM in term of bioclimatic response curves and potential distribution under current climate. According to the species and the spatial resolution of the calibration dataset, shapes of bioclimatic response curves the modelled species distribution maps differed markedly between the SSDM and classical SDMs. The magnitude and directions of these differences were dependent on the correlations between the errors from both equations and were highest for higher spatial resolutions. A first conclusion is that the use of classical SDMs can potentially lead to strong miss-estimation of the actual and future probability of presence modelled. Beyond this selection bias, the SSDM we propose represents a crucial step to account for economic constraints on tree

  1. Basis of antimalarial action: non-weak base effects of chloroquine on acid vesicle pH

    SciTech Connect

    Krogstad, D.J.; Schlesinger, P.H.

    1987-03-01

    Biologically active concentrations of chloroquine increase the pH of the parasite's acid vesicles within 3-5 min. This increase in pH results from two mechanisms, one of which is markedly reduced in chloroquine-resistant parasites. Because chloroquine is a weak base, it increases vesicle pH by that mechanism in chloroquine-susceptible and resistant parasites and mammalian cells (based on its two pKs and on the delta pH between the acid vesicle and the extracellular environment). In chloroquine-susceptible parasites, but not resistant parasites or mammalian cells, chloroquine increases the pH of acid vesicles 700- to 800-fold more than can be accounted for by its properties as a weak base. The increase in acid vesicle pH caused by these non-weak base effects of nanomolar chloroquine in susceptible parasites suggests that chloroquine acts by interfering with acid vesicle functions in the parasite such as the endocytosis and proteolysis of hemoglobin, and the intracellular targeting of lysosomal enzymes. The non-weak base effects of nanomolar chloroquine on parasite vesicle pH are also responsible for its safety because these chloroquine concentrations do not affect mammalian cells.

  2. General analytical procedure for determination of acidity parameters of weak acids and bases.

    PubMed

    Pilarski, Bogusław; Kaliszan, Roman; Wyrzykowski, Dariusz; Młodzianowski, Janusz; Balińska, Agata

    2015-01-01

    The paper presents a new convenient, inexpensive, and reagent-saving general methodology for the determination of pK a values for components of the mixture of diverse chemical classes weak organic acids and bases in water solution, without the need to separate individual analytes. The data obtained from simple pH-metric microtitrations are numerically processed into reliable pK a values for each component of the mixture. Excellent agreement has been obtained between the determined pK a values and the reference literature data for compounds studied.

  3. Cluster Guide. Accounting Occupations.

    ERIC Educational Resources Information Center

    Beaverton School District 48, OR.

    Based on a recent task inventory of key occupations in the accounting cluster taken in the Portland, Oregon, area, this curriculum guide is intended to assist administrators and teachers in the design and implementation of high school accounting cluster programs. The guide is divided into four major sections: program organization and…

  4. A soil moisture accounting-procedure with a Richards' equation-based soil texture-dependent parameterization

    NASA Astrophysics Data System (ADS)

    Mathias, Simon A.; Skaggs, Todd H.; Quinn, Simon A.; Egan, Sorcha N. C.; Finch, Lucy E.; Oldham, Corinne D.

    2015-01-01

    Given a time series of potential evapotranspiration and rainfall data, there are at least two approaches for estimating vertical percolation rates. One approach involves solving Richards' equation (RE) with a plant uptake model. An alternative approach involves applying a simple soil moisture accounting procedure (SMAP) based on a set of conceptual stores and conditional statements. It is often desirable to parameterize distributed vertical percolation models using regional soil texture maps. This can be achieved using pedotransfer functions when applying RE. However, robust soil texture based parameterizations for more simple SMAPs have not previously been available. This article presents a new SMAP designed to emulate the response of a one-dimensional homogenous RE model. Model parameters for 231 different soil textures are obtained by calibrating the SMAP model to 20 year time series from equivalent RE model simulations. The results are then validated by comparing to an additional 13 years of simulated RE model data. The resulting work provides a new simple two parameter (% sand and % silt) SMAP, which provides consistent vertical percolation data as compared to RE based models. Results from the 231 numerical simulations are also found to be qualitatively consistent with intuitive ideas concerning soil texture and soil moisture dynamics. Vertical percolation rates are found to be highest in sandy soils. Sandy soils are found to provide less water for evapotranspiration. Surface runoff is found to be more important in soils with high clay content.

  5. Determination of the Acid-Base Dissociation Constant of Acid-Degradable Hexamethylenetetramine by Capillary Zone Electrophoresis.

    PubMed

    Takayanagi, Toshio; Shimakami, Natsumi; Kurashina, Masashi; Mizuguchi, Hitoshi; Yabutani, Tomoki

    2016-01-01

    The acid-base equilibrium of hexamethylenetetramine (hexamine) was analyzed with its effective electrophoretic mobility by capillary zone electrophoresis. Although hexamine is degradable in a weakly acidic aqueous solution, and the degraded products of ammonia and formaldehyde can be formed, the effective electrophoretic mobility of hexamine was measured in the pH range between 2.8 and 6.9. An acid-base dissociation equilibrium of the protonated hexamine was analyzed based on the mobility change, and an acid dissociation constant of pKa = 4.93 ± 0.01 (mean ± standard error, ionic strength: 0.020 mol dm(-3)) was determined. The monoprotic acid-base equilibrium of hexamine was confirmed through comparisons of its electrophoretic mobility with the N-ethylquinolinium ion and with the monocationic N-ethyl derivative of hexamine, as well as a slope analysis of the dissociation equilibrium.

  6. Functional nucleic-acid-based sensors for environmental monitoring.

    PubMed

    Sett, Arghya; Das, Suradip; Bora, Utpal

    2014-10-01

    Efforts to replace conventional chromatographic methods for environmental monitoring with cheaper and easy to use biosensors for precise detection and estimation of hazardous environmental toxicants, water or air borne pathogens as well as various other chemicals and biologics are gaining momentum. Out of the various types of biosensors classified according to their bio-recognition principle, nucleic-acid-based sensors have shown high potential in terms of cost, sensitivity, and specificity. The discovery of catalytic activities of RNA (ribozymes) and DNA (DNAzymes) which could be triggered by divalent metallic ions paved the way for their extensive use in detection of heavy metal contaminants in environment. This was followed with the invention of small oligonucleotide sequences called aptamers which can fold into specific 3D conformation under suitable conditions after binding to target molecules. Due to their high affinity, specificity, reusability, stability, and non-immunogenicity to vast array of targets like small and macromolecules from organic, inorganic, and biological origin, they can often be exploited as sensors in industrial waste management, pollution control, and environmental toxicology. Further, rational combination of the catalytic activity of DNAzymes and RNAzymes along with the sequence-specific binding ability of aptamers have given rise to the most advanced form of functional nucleic-acid-based sensors called aptazymes. Functional nucleic-acid-based sensors (FNASs) can be conjugated with fluorescent molecules, metallic nanoparticles, or quantum dots to aid in rapid detection of a variety of target molecules by target-induced structure switch (TISS) mode. Although intensive research is being carried out for further improvements of FNAs as sensors, challenges remain in integrating such bio-recognition element with advanced transduction platform to enable its use as a networked analytical system for tailor made analysis of environmental

  7. Liquid crystal based biosensors for bile acid detection

    NASA Astrophysics Data System (ADS)

    He, Sihui; Liang, Wenlang; Tanner, Colleen; Fang, Jiyu; Wu, Shin-Tson

    2013-03-01

    The concentration level of bile acids is a useful indicator for early diagnosis of liver diseases. The prevalent measurement method in detecting bile acids is the chromatography coupled with mass spectrometry, which is precise yet expensive. Here we present a biosensor platform based on liquid crystal (LC) films for the detection of cholic acid (CA). This platform has the advantage of low cost, label-free, solution phase detection and simple analysis. In this platform, LC film of 4-Cyano-4'-pentylbiphenyl (5CB) was hosted by a copper grid supported with a polyimide-coated glass substrate. By immersing into sodium dodecyl sulfate (SDS) solution, the LC film was coated with SDS which induced a homeotropic anchoring of 5CB. Addition of CA introduced competitive adsorption between CA and SDS at the interface, triggering a transition from homeotropic to homogeneous anchoring. The detection limit can be tuned by changing the pH value of the solution from 12uM to 170uM.

  8. Effect of growth hormone on renal and systemic acid-base homeostasis in humans.

    PubMed

    Sicuro, A; Mahlbacher, K; Hulter, H N; Krapf, R

    1998-04-01

    The effects of recombinant human growth hormone (GH, 0.1 U.kg body wt-1.12 h-1) on systemic and renal acid-base homeostasis were investigated in six normal subjects with preexisting sustained chronic metabolic acidosis, induced by NH4Cl administration (4.2 mmol.kg body wt-1.day-1). GH administration increased and maintained plasma bicarbonate concentration from 14.1 +/- 1.4 to 18.6 +/- 1.1 mmol/l (P < 0.001). The GH-induced increase in plasma bicarbonate concentration was the consequence of a significant increase in net acid excretion that was accounted for largely by an increase in renal NH+4 excretion sufficient in magnitude to override a decrease in urinary titratable acid excretion. During GH administration, urinary pH increased and correlated directly and significantly with urinary NH4+ concentration. Urinary net acid excretion rates were not different during the steady-state periods of acidosis and acidosis with GH administration. Glucocorticoid and mineralocorticoid activities increased significantly in response to acidosis and were suppressed (glucocorticoid) or decreased to control levels (mineralocorticoid) by GH. The partial correction of metabolic acidosis occurred despite GH-induced renal sodium retention (180 mmol; gain in weight of 1.8 +/- 0.2 kg, P < 0.005) and decreased glucocorticoid and mineralocorticoid activities. Thus GH (and/or insulin-like growth factor I) increased plasma bicarbonate concentration and partially corrected metabolic acidosis. This effect was generated in large part by and maintained fully by a renal mechanism (i.e., increased renal NH3 production and NH+4/net acid excretion).

  9. A fully automatic system for acid-base coulometric titrations

    PubMed Central

    Cladera, A.; Caro, A.; Estela, J. M.; Cerdà, V.

    1990-01-01

    An automatic system for acid-base titrations by electrogeneration of H+ and OH- ions, with potentiometric end-point detection, was developed. The system includes a PC-compatible computer for instrumental control, data acquisition and processing, which allows up to 13 samples to be analysed sequentially with no human intervention. The system performance was tested on the titration of standard solutions, which it carried out with low errors and RSD. It was subsequently applied to the analysis of various samples of environmental and nutritional interest, specifically waters, soft drinks and wines. PMID:18925283

  10. Predicting the Viscosity of Low VOC Vinyl Ester and Fatty Acid-Based Resins

    DTIC Science & Technology

    2005-12-01

    The sample was titrated with the perchloric acid / peracetic acid solution (Aldrich) until the indicator, 0.1% crystal violet in acetic acid (Aldrich...Predicting the Viscosity of Low VOC Vinyl Ester and Fatty Acid -Based Resins by John J. La Scala, Amutha Jeyarajasingam, Cherise Winston...Aberdeen Proving Ground, MD 21005-5069 ARL-TR-3681 December 2005 Predicting the Viscosity of Low VOC Vinyl Ester and Fatty Acid -Based

  11. A modified Shockley equation taking into account the multi-element nature of light emitting diodes based on nanowire ensembles.

    PubMed

    Musolino, M; Tahraoui, A; Treeck, D van; Geelhaar, L; Riechert, H

    2016-07-08

    In this work we study how the multi-element nature of light emitting diodes (LEDs) based on nanowire (NW) ensembles influences their current voltage (I-V) characteristics. We systematically address critical issues of the fabrication process that can result in significant fluctuations of the electrical properties among the individual NWs in such LEDs, paying particular attention to the planarization step. Electroluminescence (EL) maps acquired for two nominally identical NW-LEDs reveal that small processing variations can result in a large difference in the number of individual nano-devices emitting EL. The lower number of EL spots in one of the LEDs is caused by its inhomogeneous electrical properties. The I-V characteristics of this LED cannot be described well by the classical Shockley model. We are able to take into account the multi-element nature of such LEDs and fit the I-V characteristics in the forward bias regime by employing an ad hoc adjusted version of the Shockley equation. More specifically, we introduce a bias dependence of the ideality factor. The basic considerations of our model should remain valid also for other types of devices based on ensembles of interconnected p-n junctions with inhomogeneous electrical properties, regardless of the employed material system.

  12. A modified Shockley equation taking into account the multi-element nature of light emitting diodes based on nanowire ensembles

    NASA Astrophysics Data System (ADS)

    Musolino, M.; Tahraoui, A.; van Treeck, D.; Geelhaar, L.; Riechert, H.

    2016-07-01

    In this work we study how the multi-element nature of light emitting diodes (LEDs) based on nanowire (NW) ensembles influences their current voltage (I-V) characteristics. We systematically address critical issues of the fabrication process that can result in significant fluctuations of the electrical properties among the individual NWs in such LEDs, paying particular attention to the planarization step. Electroluminescence (EL) maps acquired for two nominally identical NW-LEDs reveal that small processing variations can result in a large difference in the number of individual nano-devices emitting EL. The lower number of EL spots in one of the LEDs is caused by its inhomogeneous electrical properties. The I-V characteristics of this LED cannot be described well by the classical Shockley model. We are able to take into account the multi-element nature of such LEDs and fit the I-V characteristics in the forward bias regime by employing an ad hoc adjusted version of the Shockley equation. More specifically, we introduce a bias dependence of the ideality factor. The basic considerations of our model should remain valid also for other types of devices based on ensembles of interconnected p-n junctions with inhomogeneous electrical properties, regardless of the employed material system.

  13. Soluble adenylyl cyclase is an acid-base sensor in epithelial base-secreting cells.

    PubMed

    Roa, Jinae N; Tresguerres, Martin

    2016-08-01

    Blood acid-base regulation by specialized epithelia, such as gills and kidney, requires the ability to sense blood acid-base status. Here, we developed primary cultures of ray (Urolophus halleri) gill cells to study mechanisms for acid-base sensing without the interference of whole animal hormonal regulation. Ray gills have abundant base-secreting cells, identified by their noticeable expression of vacuolar-type H(+)-ATPase (VHA), and also express the evolutionarily conserved acid-base sensor soluble adenylyl cyclase (sAC). Exposure of cultured cells to extracellular alkalosis (pH 8.0, 40 mM HCO3 (-)) triggered VHA translocation to the cell membrane, similar to previous reports in live animals experiencing blood alkalosis. VHA translocation was dependent on sAC, as it was blocked by the sAC-specific inhibitor KH7. Ray gill base-secreting cells also express transmembrane adenylyl cyclases (tmACs); however, tmAC inhibition by 2',5'-dideoxyadenosine did not prevent alkalosis-dependent VHA translocation, and tmAC activation by forskolin reduced the abundance of VHA at the cell membrane. This study demonstrates that sAC is a necessary and sufficient sensor of extracellular alkalosis in ray gill base-secreting cells. In addition, this study indicates that different sources of cAMP differentially modulate cell biology.

  14. Applications of synchrotron-based spectroscopic techniques in studying nucleic acids and nucleic acid-functionalized nanomaterials

    PubMed Central

    Wu, Peiwen; Yu, Yang; McGhee, Claire E.; Tan, Li Huey

    2014-01-01

    In this review, we summarize recent progresses in the application of synchrotron-based spectroscopic techniques for nucleic acid research that takes advantage of high-flux and high-brilliance electromagnetic radiation from synchrotron sources. The first section of the review focuses on the characterization of the structure and folding processes of nucleic acids using different types of synchrotron-based spectroscopies, such as X-ray absorption spectroscopy, X-ray emission spectroscopy, X-ray photoelectron spectroscopy, synchrotron radiation circular dichroism, X-ray footprinting and small-angle X-ray scattering. In the second section, the characterization of nucleic acid-based nanostructures, nucleic acid-functionalized nanomaterials and nucleic acid-lipid interactions using these spectroscopic techniques is summarized. Insights gained from these studies are described and future directions of this field are also discussed. PMID:25205057

  15. Applications of synchrotron-based spectroscopic techniques in studying nucleic acids and nucleic acid-functionalized nanomaterials.

    PubMed

    Wu, Peiwen; Yu, Yang; McGhee, Claire E; Tan, Li Huey; Lu, Yi

    2014-12-10

    In this review, we summarize recent progress in the application of synchrotron-based spectroscopic techniques for nucleic acid research that takes advantage of high-flux and high-brilliance electromagnetic radiation from synchrotron sources. The first section of the review focuses on the characterization of the structure and folding processes of nucleic acids using different types of synchrotron-based spectroscopies, such as X-ray absorption spectroscopy, X-ray emission spectroscopy, X-ray photoelectron spectroscopy, synchrotron radiation circular dichroism, X-ray footprinting and small-angle X-ray scattering. In the second section, the characterization of nucleic acid-based nanostructures, nucleic acid-functionalized nanomaterials and nucleic acid-lipid interactions using these spectroscopic techniques is summarized. Insights gained from these studies are described and future directions of this field are also discussed.

  16. Applications of synchrotron-based spectroscopic techniques in studying nucleic acids and nucleic acid-functionalized nanomaterials

    SciTech Connect

    Wu, Peiwen; Yu, Yang; McGhee, Claire E.; Tan, Li Huey; Lu, Yi

    2014-09-10

    In this paper, we summarize recent progress in the application of synchrotron-based spectroscopic techniques for nucleic acid research that takes advantage of high-flux and high-brilliance electromagnetic radiation from synchrotron sources. The first section of the review focuses on the characterization of the structure and folding processes of nucleic acids using different types of synchrotron-based spectroscopies, such as X-ray absorption spectroscopy, X-ray emission spectroscopy, X-ray photoelectron spectroscopy, synchrotron radiation circular dichroism, X-ray footprinting and small-angle X-ray scattering. In the second section, the characterization of nucleic acid-based nanostructures, nucleic acid-functionalized nanomaterials and nucleic acid-lipid interactions using these spectroscopic techniques is summarized. Insights gained from these studies are described and future directions of this field are also discussed.

  17. Applications of synchrotron-based spectroscopic techniques in studying nucleic acids and nucleic acid-functionalized nanomaterials

    DOE PAGES

    Wu, Peiwen; Yu, Yang; McGhee, Claire E.; ...

    2014-09-10

    In this paper, we summarize recent progress in the application of synchrotron-based spectroscopic techniques for nucleic acid research that takes advantage of high-flux and high-brilliance electromagnetic radiation from synchrotron sources. The first section of the review focuses on the characterization of the structure and folding processes of nucleic acids using different types of synchrotron-based spectroscopies, such as X-ray absorption spectroscopy, X-ray emission spectroscopy, X-ray photoelectron spectroscopy, synchrotron radiation circular dichroism, X-ray footprinting and small-angle X-ray scattering. In the second section, the characterization of nucleic acid-based nanostructures, nucleic acid-functionalized nanomaterials and nucleic acid-lipid interactions using these spectroscopic techniques is summarized. Insightsmore » gained from these studies are described and future directions of this field are also discussed.« less

  18. The effects of borate minerals on the synthesis of nucleic acid bases, amino acids and biogenic carboxylic acids from formamide.

    PubMed

    Saladino, Raffaele; Barontini, Maurizio; Cossetti, Cristina; Di Mauro, Ernesto; Crestini, Claudia

    2011-08-01

    The thermal condensation of formamide in the presence of mineral borates is reported. The products afforded are precursors of nucleic acids, amino acids derivatives and carboxylic acids. The efficiency and the selectivity of the reaction was studied in relation to the elemental composition of the 18 minerals analyzed. The possibility of synthesizing at the same time building blocks of both genetic and metabolic apparatuses, along with the production of amino acids, highlights the interest of the formamide/borate system in prebiotic chemistry.

  19. Effect of temperature on the acid-base properties of the alumina surface: microcalorimetry and acid-base titration experiments.

    PubMed

    Morel, Jean-Pierre; Marmier, Nicolas; Hurel, Charlotte; Morel-Desrosiers, Nicole

    2006-06-15

    Sorption reactions on natural or synthetic materials that can attenuate the migration of pollutants in the geosphere could be affected by temperature variations. Nevertheless, most of the theoretical models describing sorption reactions are at 25 degrees C. To check these models at different temperatures, experimental data such as the enthalpies of sorption are thus required. Highly sensitive microcalorimeters can now be used to determine the heat effects accompanying the sorption of radionuclides on oxide-water interfaces, but enthalpies of sorption cannot be extracted from microcalorimetric data without a clear knowledge of the thermodynamics of protonation and deprotonation of the oxide surface. However, the values reported in the literature show large discrepancies and one must conclude that, amazingly, this fundamental problem of proton binding is not yet resolved. We have thus undertaken to measure by titration microcalorimetry the heat effects accompanying proton exchange at the alumina-water interface at 25 degrees C. Based on (i) the surface sites speciation provided by a surface complexation model (built from acid-base titrations at 25 degrees C) and (ii) results of the microcalorimetric experiments, calculations have been made to extract the enthalpic variations associated respectively to first and second deprotonation of the alumina surface. Values obtained are deltaH1 = 80+/-10 kJ mol(-1) and deltaH2 = 5+/-3 kJ mol(-1). In a second step, these enthalpy values were used to calculate the alumina surface acidity constants at 50 degrees C via the van't Hoff equation. Then a theoretical titration curve at 50 degrees C was calculated and compared to the experimental alumina surface titration curve. Good agreement between the predicted acid-base titration curve and the experimental one was observed.

  20. Sphingoid bases inhibit acid-induced demineralization of hydroxyapatite.

    PubMed

    Valentijn-Benz, Marianne; van 't Hof, Wim; Bikker, Floris J; Nazmi, Kamran; Brand, Henk S; Sotres, Javier; Lindh, Liselott; Arnebrant, Thomas; Veerman, Enno C I

    2015-01-01

    Calcium hydroxyapatite (HAp), the main constituent of dental enamel, is inherently susceptible to the etching and dissolving action of acids, resulting in tooth decay such as dental caries and dental erosion. Since the prevalence of erosive wear is gradually increasing, there is urgent need for agents that protect the enamel against erosive attacks. In the present study we studied in vitro the anti-erosive effects of a number of sphingolipids and sphingoid bases, which form the backbone of sphingolipids. Pretreatment of HAp discs with sphingosine, phytosphingosine (PHS), PHS phosphate and sphinganine significantly protected these against acid-induced demineralization by 80 ± 17%, 78 ± 17%, 78 ± 7% and 81 ± 8%, respectively (p < 0.001). On the other hand, sphingomyelin, acetyl PHS, octanoyl PHS and stearoyl PHS had no anti-erosive effects. Atomic force measurement revealed that HAp discs treated with PHS were almost completely and homogeneously covered by patches of PHS. This suggests that PHS and other sphingoid bases form layers on the surface of HAp, which act as diffusion barriers against H(+) ions. In principle, these anti-erosive properties make PHS and related sphingosines promising and attractive candidates as ingredients in oral care products.

  1. Canadian Tire Money: An Analogy for Use When Discussing Weak Acid Strong Base Titrations

    NASA Astrophysics Data System (ADS)

    Last, Arthur M.

    2003-12-01

    A simple analogy can often provide an instructor with a means of helping students to understand an unfamiliar concept. An analogy involving money can be particularly helpful as most students have experience in dealing with a range of financial transactions in their everyday lives. In this article, use is made of the practice of one well-known Canadian retail chain in returning to its customers a small percentage of an item's purchase price in the form of imitation bank notes that can subsequently be spent in the chain's stores. An analogy is drawn between this practice and the determination of the pKa of a weak acid by titrating it with a strong base, taking into account the hydrolysis of the anion produced.

  2. Method of Identifying a Base in a Nucleic Acid

    DOEpatents

    Fodor, Stephen P. A.; Lipshutz, Robert J.; Huang, Xiaohua

    1999-01-01

    Devices and techniques for hybridization of nucleic acids and for determining the sequence of nucleic acids. Arrays of nucleic acids are formed by techniques, preferably high resolution, light-directed techniques. Positions of hybridization of a target nucleic acid are determined by, e.g., epifluorescence microscopy. Devices and techniques are proposed to determine the sequence of a target nucleic acid more efficiently and more quickly through such synthesis and detection techniques.

  3. Probe kit for identifying a base in a nucleic acid

    DOEpatents

    Fodor, Stephen P. A.; Lipshutz, Robert J.; Huang, Xiaohua

    2001-01-01

    Devices and techniques for hybridization of nucleic acids and for determining the sequence of nucleic acids. Arrays of nucleic acids are formed by techniques, preferably high resolution, light-directed techniques. Positions of hybridization of a target nucleic acid are determined by, e.g., epifluorescence microscopy. Devices and techniques are proposed to determine the sequence of a target nucleic acid more efficiently and more quickly through such synthesis and detection techniques.

  4. Hybridization and sequencing of nucleic acids using base pair mismatches

    DOEpatents

    Fodor, Stephen P. A.; Lipshutz, Robert J.; Huang, Xiaohua

    2001-01-01

    Devices and techniques for hybridization of nucleic acids and for determining the sequence of nucleic acids. Arrays of nucleic acids are formed by techniques, preferably high resolution, light-directed techniques. Positions of hybridization of a target nucleic acid are determined by, e.g., epifluorescence microscopy. Devices and techniques are proposed to determine the sequence of a target nucleic acid more efficiently and more quickly through such synthesis and detection techniques.

  5. Microarray-based transcriptome of Listeria monocytogenes adapted to sublethal concentrations of acetic acid, lactic acid, and hydrochloric acid.

    PubMed

    Tessema, Girum Tadesse; Møretrø, Trond; Snipen, Lars; Heir, Even; Holck, Askild; Naterstad, Kristine; Axelsson, Lars

    2012-09-01

    Listeria monocytogenes , an important foodborne pathogen, commonly encounters organic acids in food-related environments. The transcriptome of L. monocytogenes L502 was analyzed after adaptation to pH 5 in the presence of acetic acid, lactic acid, or hydrochloric acid (HCl) at 25 °C, representing a condition encountered in mildly acidic ready-to-eat food kept at room temperature. The acid-treated cells were compared with a reference culture with a pH of 6.7 at the time of RNA harvesting. The number of genes and magnitude of transcriptional responses were higher for the organic acids than for HCl. Protein coding genes described for low pH stress, energy transport and metabolism, virulence determinates, and acid tolerance response were commonly regulated in the 3 acid-stressed cultures. Interestingly, the transcriptional levels of histidine and cell wall biosynthetic operons were upregulated, indicating possible universal response against low pH stress in L. monocytogenes. The opuCABCD operon, coding proteins for compatible solutes transport, and the transcriptional regulator sigL were significantly induced in the organic acids, strongly suggesting key roles during organic acid stress. The present study revealed the complex transcriptional responses of L. monocytogenes towards food-related acidulants and opens the roadmap for more specific and in-depth future studies.

  6. Assessing the Success of a Discipline-Based Communication Skills Development and Enhancement Program in a Graduate Accounting Course

    ERIC Educational Resources Information Center

    Barratt, Catherine; Hanlon, Dean; Rankin, Michaela

    2011-01-01

    In this paper we present results of the impact diagnostic testing and associated context-specific workshops have on students' written communication skills in a graduate-level accounting course. We find that students who undertook diagnostic testing performed better in their first semester accounting subject. This improvement is positively…

  7. Teaching the Indirect Method of the Statement of Cash Flows in Introductory Financial Accounting: A Comprehensive, Problem-Based Approach

    ERIC Educational Resources Information Center

    Brickner, Daniel R.; McCombs, Gary B.

    2004-01-01

    In this article, the authors provide an instructional resource for presenting the indirect method of the statement of cash flows (SCF) in an introductory financial accounting course. The authors focus primarily on presenting a comprehensive example that illustrates the "why" of SCF preparation and show how journal entries and T-accounts can be…

  8. Statistical Properties of Accountability Measures Based on ACT's Educational Planning and Assessment System. ACT Research Report Series, 2009-1

    ERIC Educational Resources Information Center

    Allen, Jeff; Bassiri, Dina; Noble, Julie

    2009-01-01

    Educational accountability has grown substantially over the last decade, due in large part to the No Child Left Behind Act of 2001. Accordingly, educational researchers and policymakers are interested in the statistical properties of accountability models used for NCLB, such as status, improvement, and growth models; as well as others that are not…

  9. Nutrient based estimation of acid-base balance in vegetarians and non-vegetarians.

    PubMed

    Deriemaeker, Peter; Aerenhouts, Dirk; Hebbelinck, Marcel; Clarys, Peter

    2010-03-01

    A first objective of the present study was to estimate the acid-base balance of the food intake in vegetarians and non-vegetarians. A second objective was to evaluate if additional input of specific food items on the existing potential renal acid load (PRAL) list was necessary for the comparison of the two dietary patterns. Thirty vegetarians between the age of 18 and 30 years were matched for sex, age and BMI with 30 non-vegetarians. Based on the 3-days food diaries the acid-base status of the food intake was estimated using the PRAL method. Mean PRAL values as estimated with the standard table yielded an alkaline load of -5.4 +/- 14.4 mEq/d in the vegetarians compared to an acid load of 10.3 +/- 14.4 mEq/d in the nonvegetarians (p<0.001). Mean PRAL values as estimated with the extended table yielded an alkaline load of -10.9 +/-19.7 mEq/d in the vegetarians compared to an acid load of 13.8 +/- 17.1 mEq/d for the non-vegetarians (p<0.001). The findings of this study indicate that vegetarian food intake produces more alkaline outcomes compared to non-vegetarian diets. The use of the standard PRAL table was sufficient for discrimination between the two diets.

  10. [Microspeciation of amphoteric molecules of unusual acid-base properties].

    PubMed

    Kóczián, Kristóf

    2007-01-01

    The phisico-chemical properties of bio- and drug molecules greatly influence their interactions in the body and strongly effect the mechanism of drug action. Among these properties, macroscopic and site-specific protonation constants are of crucial importance. Latter one is the tool to calculate the relative concentration of the various microspecies in the compartments of the body at different pH values, and also, it is the versatile parameter to improve the pharmacokinetic properties of a new molecule in a particular family of drugs. In the present thesis work, the microspeciation of three molecules of great pharmaceutical importance and unusual acid-base properties, were carried out. The microconstants of tenoxicam, the non-steroidal anti-inflammatory drug, were described, introducing a novel deductive method using Hammett constants. For this purpose, a total of 8 tenoxicam and piroxicam derivatives were synthesised. To the best of our knowledge, the log k(N)O microconstant of tenoxicam obtained thus is the lowest enolate basicity value, which, however, can be well explained by the effects of the intramolecular environment. The developed evaluation procedure is suitable for microconstant determination of compounds in other molecule families. Besides, prodrug-type compounds and analogues similar to the structures of selective COX-2 isoenzyme inhibitors were synthesised. The other two molecules studied, the 6-aminopenicillanic acid and 7-cephalosporanic acid, the core molecules of the two most important beta-lactam antibiotic-types were derivatised and investigated by 1D and 2D NMR techniques. The NMR-pH titration on the parent compounds and their ester derivatives, combined with in situ pH-measurements allowed the microspeciation of these easily decomposing molecules. One of the protonation constant of 7-ACA (log kN(O) = 4.12), to the best of our knowledge, is the least non-aromatic basic amino-site among the natural compounds.

  11. PPDF-based method to account for atmospheric light scattering in observations of carbon dioxide from space

    NASA Astrophysics Data System (ADS)

    Oshchepkov, Sergey; Bril, Andrey; Yokota, Tatsuya

    2008-12-01

    We present an original method that accounts for thin clouds in carbon dioxide retrievals from space-based reflected sunlight observations in near-infrared regions. This approach involves a reasonable, simple parameterization of effective transmittance using a set of parameters that describe the path-length modification caused by clouds. The complete retrieval scheme included the following: estimation of cloud parameters from the 0.76-μm O2 A-band and from the H2O-saturated absorption area of the 2.0-μm band; a necessary correction to utilize these parameters at the target CO2 1.58-μm band using estimated ground surface albedo outside of gas absorption lines in this band; and retrieval of CO2 amount at the 1.58-μm band using a maximum a posteriori method of inversion. The primary retrieved parameters refer to the CO2 volume mixing ratio vertical profile that is then transformed to an averaged-column amount under a pre-defined increment of pressure. A set of numerical simulations with synthetic radiance spectra particular to Greenhouse Gases Observing Satellite (GOSAT) observations showed that the proposed method provides acceptably accurate CO2 retrievals from an atmosphere that includes thin cirrus clouds. Efficiency of the aerosol and cloud corrections was demonstrated by comparing it with a modified iterative maximum a posteriori-DOAS (IMAP-DOAS) that neglects path length modifications due to the scattering effects.

  12. Accounting for non-photosynthetic vegetation in remote-sensing-based estimates of carbon flux in wetlands

    USGS Publications Warehouse

    Schile, Lisa M.; Byrd, Kristin B.; Windham-Myers, Lisamarie; Kelly, Maggi

    2013-01-01

    Monitoring productivity in coastal wetlands is important due to their high carbon sequestration rates and potential role in climate change mitigation. We tested agricultural- and forest-based methods for estimating the fraction of absorbed photosynthetically active radiation (f APAR), a key parameter for modelling gross primary productivity (GPP), in a restored, managed wetland with a dense litter layer of non-photosynthetic vegetation, and we compared the difference in canopy light transmission between a tidally influenced wetland and the managed wetland. The presence of litter reduced correlations between spectral vegetation indices and f APAR. In the managed wetland, a two-band vegetation index incorporating simulated World View-2 or Hyperion green and near-infrared bands, collected with a field spectroradiometer, significantly correlated with f APAR only when measured above the litter layer, not at the ground where measurements typically occur. Measures of GPP in these systems are difficult to capture via remote sensing, and require an investment of sampling effort, practical methods for measuring green leaf area and accounting for background effects of litter and water.

  13. An Intention-Based Account of Perspective-Taking: Why Perspective-Taking Can Both Decrease and Increase Moral Condemnation.

    PubMed

    Lucas, Brian J; Galinksy, Adam D; Murnighan, Keith J

    2016-09-20

    Perspective-taking often increases generosity in behavior and attributions. We present an intentions-based account to explain how perspective-taking can both decrease and increase moral condemnation. Consistent with past research, we predicted perspective-taking would reduce condemnation when the perspective-taker initially attributed benevolent intent to a transgressor. However, we predicted perspective-taking would increase condemnation when malevolent intentions were initially attributed to the wrongdoer. We propose that perspective-taking amplifies the intentions initially attributed to a transgressor. Three studies measured and manipulated intention attributions and found that perspective-taking increased condemnation when malevolent intentions were initially attributed to a transgressor. Perspective-taking also increased costly punishment of a transgressor, an effect mediated by malevolent intentions. In contrast, empathy did not increase punitive responses, supporting its conceptual distinction from perspective-taking. Whether perspective-taking leads to forgiveness or condemnation depends on the intentions the perspective-taker initially attributes to a transgressor.

  14. Acid-base titrations using microfluidic paper-based analytical devices.

    PubMed

    Karita, Shingo; Kaneta, Takashi

    2014-12-16

    Rapid and simple acid-base titration was accomplished using a novel microfluidic paper-based analytical device (μPAD). The μPAD was fabricated by wax printing and consisted of ten reservoirs for reaction and detection. The reaction reservoirs contained various amounts of a primary standard substance, potassium hydrogen phthalate (KHPth), whereas a constant amount of phenolphthalein was added to all the detection reservoirs. A sample solution containing NaOH was dropped onto the center of the μPAD and was allowed to spread to the reaction reservoirs where the KHPth neutralized it. When the amount of NaOH exceeded that of the KHPth in the reaction reservoirs, unneutralized hydroxide ion penetrated the detection reservoirs, resulting in a color reaction from the phenolphthalein. Therefore, the number of the detection reservoirs with no color change determined the concentration of the NaOH in the sample solution. The titration was completed within 1 min by visually determining the end point, which required neither instrumentation nor software. The volumes of the KHPth and phenolphthalein solutions added to the corresponding reservoirs were optimized to obtain reproducible and accurate results for the concentration of NaOH. The μPADs determined the concentration of NaOH at orders of magnitude ranging from 0.01 to 1 M. An acid sample, HCl, was also determined using Na2CO3 as a primary standard substance instead of KHPth. Furthermore, the μPAD was applicable to the titrations of nitric acid, sulfuric acid, acetic acid, and ammonia solutions. The μPADs were stable for more than 1 month when stored in darkness at room temperature, although this was reduced to only 5 days under daylight conditions. The analysis of acidic hot spring water was also demonstrated in the field using the μPAD, and the results agreed well with those obtained by classic acid-base titration.

  15. Structure of six organic acid-base adducts from 6-bromobenzo[d]thiazol-2-amine and acidic compounds

    NASA Astrophysics Data System (ADS)

    Jin, Shouwen; Zhang, Jing; Wang, Daqi; Tao, Lin; Zhou, Mengjian; Shen, Yinyan; Chen, Quan; Lin, Zhanghui; Gao, Xingjun

    2014-05-01

    Six anhydrous organic acid-base adducts of 6-bromobenzo[d]thiazol-2-amine were prepared with organic acids as 2,4,6-trinitrophenol, salicylic acid, 3,5-dinitrobenzoic acid, 3,5-dinitrosalicylic acid, malonic acid and sebacic acid. The compounds 1-6 were characterized by X-ray diffraction analysis, IR, and elemental analysis. The melting points of all the adducts were given. Of the six adducts, 1, 3, 4, and 5 are organic salts, while 2, and 6 are cocrystals. The supramolecular arrangement in the crystals 2-6 is based on the R22(8) synthon. Analysis of the crystal packing of 1-6 suggests that there are strong NH⋯O, OH⋯N, and OH⋯O hydrogen bonds (charge assisted or neutral) between acid and base components in the supramolecular assemblies. When the hydroxyl group is present in the ortho position of the carboxy, the intramolecular S6 synthon is present, as expected. Besides the classical hydrogen bonding interactions, other noncovalent interactions also play important roles in structure extension. Due to the synergetic effect of these weak interactions, compounds 1-6 display 1D-3D framework structure.

  16. Fast high-throughput method for the determination of acidity constants by capillary electrophoresis: I. Monoprotic weak acids and bases.

    PubMed

    Fuguet, Elisabet; Ràfols, Clara; Bosch, Elisabeth; Rosés, Martí

    2009-04-24

    A new and fast method to determine acidity constants of monoprotic weak acids and bases by capillary zone electrophoresis based on the use of an internal standard (compound of similar nature and acidity constant as the analyte) has been developed. This method requires only two electrophoretic runs for the determination of an acidity constant: a first one at a pH where both analyte and internal standard are totally ionized, and a second one at another pH where both are partially ionized. Furthermore, the method is not pH dependent, so an accurate measure of the pH of the buffer solutions is not needed. The acidity constants of several phenols and amines have been measured using internal standards of known pK(a), obtaining a mean deviation of 0.05 pH units compared to the literature values.

  17. Health-Based Audible Noise Guidelines Account for Infrasound and Low-Frequency Noise Produced by Wind Turbines

    PubMed Central

    Berger, Robert G.; Ashtiani, Payam; Ollson, Christopher A.; Whitfield Aslund, Melissa; McCallum, Lindsay C.; Leventhall, Geoff; Knopper, Loren D.

    2015-01-01

    Setbacks for wind turbines have been established in many jurisdictions to address potential health concerns associated with audible noise. However, in recent years, it has been suggested that infrasound (IS) and low-frequency noise (LFN) could be responsible for the onset of adverse health effects self-reported by some individuals living in proximity to wind turbines, even when audible noise limits are met. The purpose of this paper was to investigate whether current audible noise-based guidelines for wind turbines account for the protection of human health, given the levels of IS and LFN typically produced by wind turbines. New field measurements of indoor IS and outdoor LFN at locations between 400 and 900 m from the nearest turbine, which were previously underrepresented in the scientific literature, are reported and put into context with existing published works. Our analysis showed that indoor IS levels were below auditory threshold levels while LFN levels at distances >500 m were similar to background LFN levels. A clear contribution to LFN due to wind turbine operation (i.e., measured with turbines on in comparison to with turbines off) was noted at a distance of 480 m. However, this corresponded to an increase in overall audible sound measures as reported in dB(A), supporting the hypothesis that controlling audible sound produced by normally operating wind turbines will also control for LFN. Overall, the available data from this and other studies suggest that health-based audible noise wind turbine siting guidelines provide an effective means to evaluate, monitor, and protect potential receptors from audible noise as well as IS and LFN. PMID:25759808

  18. Health-based audible noise guidelines account for infrasound and low-frequency noise produced by wind turbines.

    PubMed

    Berger, Robert G; Ashtiani, Payam; Ollson, Christopher A; Whitfield Aslund, Melissa; McCallum, Lindsay C; Leventhall, Geoff; Knopper, Loren D

    2015-01-01

    Setbacks for wind turbines have been established in many jurisdictions to address potential health concerns associated with audible noise. However, in recent years, it has been suggested that infrasound (IS) and low-frequency noise (LFN) could be responsible for the onset of adverse health effects self-reported by some individuals living in proximity to wind turbines, even when audible noise limits are met. The purpose of this paper was to investigate whether current audible noise-based guidelines for wind turbines account for the protection of human health, given the levels of IS and LFN typically produced by wind turbines. New field measurements of indoor IS and outdoor LFN at locations between 400 and 900 m from the nearest turbine, which were previously underrepresented in the scientific literature, are reported and put into context with existing published works. Our analysis showed that indoor IS levels were below auditory threshold levels while LFN levels at distances >500 m were similar to background LFN levels. A clear contribution to LFN due to wind turbine operation (i.e., measured with turbines on in comparison to with turbines off) was noted at a distance of 480 m. However, this corresponded to an increase in overall audible sound measures as reported in dB(A), supporting the hypothesis that controlling audible sound produced by normally operating wind turbines will also control for LFN. Overall, the available data from this and other studies suggest that health-based audible noise wind turbine siting guidelines provide an effective means to evaluate, monitor, and protect potential receptors from audible noise as well as IS and LFN.

  19. Kinetics of acid base catalyzed transesterification of Jatropha curcas oil.

    PubMed

    Jain, Siddharth; Sharma, M P

    2010-10-01

    Out of various non-edible oil resources, Jatropha curcas oil (JCO) is considered as future feedstock for biodiesel production in India. Limited work is reported on the kinetics of transesterification of high free fatty acids containing oil. The present study reports the results of kinetic study of two-step acid base catalyzed transesterification process carried out at an optimum temperature of 65 °C and 50 °C for esterification and transesterification respectively under the optimum methanol to oil ratio of 3:7 (v/v), catalyst concentration 1% (w/w) for H₂SO₄ and NaOH. The yield of methyl ester (ME) has been used to study the effect of different parameters. The results indicate that both esterification and transesterification reaction are of first order with reaction rate constant of 0.0031 min⁻¹ and 0.008 min⁻¹ respectively. The maximum yield of 21.2% of ME during esterification and 90.1% from transesterification of pretreated JCO has been obtained.

  20. Dynamical Approach to Multiequilibria Problems for Mixtures of Acids and Their Conjugated Bases

    ERIC Educational Resources Information Center

    Glaser, Rainer E.; Delarosa, Marco A.; Salau, Ahmed Olasunkanmi; Chicone, Carmen

    2014-01-01

    Mathematical methods are described for the determination of steady-state concentrations of all species in multiequilibria systems consisting of several acids and their conjugated bases in aqueous solutions. The main example consists of a mixture of a diprotic acid H[subscript 2]A, a monoprotic acid HB, and their conjugate bases. The reaction…

  1. Spherical Nucleic Acids as Intracellular Agents for Nucleic Acid Based Therapeutics

    NASA Astrophysics Data System (ADS)

    Hao, Liangliang

    Recent functional discoveries on the noncoding sequences of human genome and transcriptome could lead to revolutionary treatment modalities because the noncoding RNAs (ncRNAs) can be applied as therapeutic agents to manipulate disease-causing genes. To date few nucleic acid-based therapeutics have been translated into the clinic due to challenges in the delivery of the oligonucleotide agents in an effective, cell specific, and non-toxic fashion. Unmodified oligonucleotide agents are destroyed rapidly in biological fluids by enzymatic degradation and have difficulty crossing the plasma membrane without the aid of transfection reagents, which often cause inflammatory, cytotoxic, or immunogenic side effects. Spherical nucleic acids (SNAs), nanoparticles consisting of densely organized and highly oriented oligonucleotides, pose one possible solution to circumventing these problems in both the antisense and RNA interference (RNAi) pathways. The unique three dimensional architecture of SNAs protects the bioactive oligonucleotides from unspecific degradation during delivery and supports their targeting of class A scavenger receptors and endocytosis via a lipid-raft-dependent, caveolae-mediated pathway. Owing to their unique structure, SNAs are able to cross cell membranes and regulate target genes expression as a single entity, without triggering the cellular innate immune response. Herein, my thesis has focused on understanding the interactions between SNAs and cellular components and developing SNA-based nanostructures to improve therapeutic capabilities. Specifically, I developed a novel SNA-based, nanoscale agent for delivery of therapeutic oligonucleotides to manipulate microRNAs (miRNAs), the endogenous post-transcriptional gene regulators. I investigated the role of SNAs involving miRNAs in anti-cancer or anti-inflammation responses in cells and in in vivo murine disease models via systemic injection. Furthermore, I explored using different strategies to construct

  2. Drug delivery systems based on nucleic acid nanostructures.

    PubMed

    de Vries, Jan Willem; Zhang, Feng; Herrmann, Andreas

    2013-12-10

    The field of DNA nanotechnology has progressed rapidly in recent years and hence a large variety of 1D-, 2D- and 3D DNA nanostructures with various sizes, geometries and shapes is readily accessible. DNA-based nanoobjects are fabricated by straight forward design and self-assembly processes allowing the exact positioning of functional moieties and the integration of other materials. At the same time some of these nanosystems are characterized by a low toxicity profile. As a consequence, the use of these architectures in a biomedical context has been explored. In this review the progress and possibilities of pristine nucleic acid nanostructures and DNA hybrid materials for drug delivery will be discussed. For the latter class of structures, a distinction is made between carriers with an inorganic core composed of gold or silica and amphiphilic DNA block copolymers that exhibit a soft hydrophobic interior.

  3. The Significance of Acid/Base Properties in Drug Discovery

    PubMed Central

    Manallack, David T.; Prankerd, Richard J.; Yuriev, Elizabeth; Oprea, Tudor I.; Chalmers, David K.

    2013-01-01

    While drug discovery scientists take heed of various guidelines concerning drug-like character, the influence of acid/base properties often remains under-scrutinised. Ionisation constants (pKa values) are fundamental to the variability of the biopharmaceutical characteristics of drugs and to underlying parameters such as logD and solubility. pKa values affect physicochemical properties such as aqueous solubility, which in turn influences drug formulation approaches. More importantly, absorption, distribution, metabolism, excretion and toxicity (ADMET) are profoundly affected by the charge state of compounds under varying pH conditions. Consideration of pKa values in conjunction with other molecular properties is of great significance and has the potential to be used to further improve the efficiency of drug discovery. Given the recent low annual output of new drugs from pharmaceutical companies, this review will provide a timely reminder of an important molecular property that influences clinical success. PMID:23099561

  4. Nucleic Acid-Based Therapy Approaches for Huntington's Disease

    PubMed Central

    Vagner, Tatyana; Young, Deborah; Mouravlev, Alexandre

    2012-01-01

    Huntington's disease (HD) is caused by a dominant mutation that results in an unstable expansion of a CAG repeat in the huntingtin gene leading to a toxic gain of function in huntingtin protein which causes massive neurodegeneration mainly in the striatum and clinical symptoms associated with the disease. Since the mutation has multiple effects in the cell and the precise mechanism of the disease remains to be elucidated, gene therapy approaches have been developed that intervene in different aspects of the condition. These approaches include increasing expression of growth factors, decreasing levels of mutant huntingtin, and restoring cell metabolism and transcriptional balance. The aim of this paper is to outline the nucleic acid-based therapeutic strategies that have been tested to date. PMID:22288011

  5. Ultrasonic and densimetric titration applied for acid-base reactions.

    PubMed

    Burakowski, Andrzej; Gliński, Jacek

    2014-01-01

    Classical acoustic acid-base titration was monitored using sound speed and density measurements. Plots of these parameters, as well as of the adiabatic compressibility coefficient calculated from them, exhibit changes with the volume of added titrant. Compressibility changes can be explained and quantitatively predicted theoretically in terms of Pasynski theory of non-compressible hydrates combined with that of the additivity of the hydration numbers with the amount and type of ions and molecules present in solution. It also seems that this development could be applied in chemical engineering for monitoring the course of chemical processes, since the applied experimental methods can be carried out almost independently on the medium under test (harmful, aggressive, etc.).

  6. The Usage of an Online Discussion Forum for the Facilitation of Case-Based Learning in an Intermediate Accounting Course: A New Zealand Case

    ERIC Educational Resources Information Center

    Weil, Sidney; McGuigan, Nicholas; Kern, Thomas

    2011-01-01

    This paper describes the implementation of an online discussion forum as a means of facilitating case-based learning in an intermediate financial accounting course. The paper commences with a review of case-based learning literature and the use of online discussions as a delivery platform, linking these pedagogical approaches to the emerging needs…

  7. Microgel Tethering For Microarray-Based Nucleic Acid Diagnostics

    NASA Astrophysics Data System (ADS)

    Dai, Xiaoguang

    Molecular diagnostics (MDx) have radically changed the process of clinical microbial identification based on identifying genetic information, MDx approaches are both specific and fast. They can identify microbes to the species and strain level over a time scale that can be as short as one hour. With such information clinicians can administer the most effective and appropriate antimicrobial treatment at an early time point with substantial implications both for patient well-being and for easing the burden on the health-care system. Among the different MDx approaches, such as fluorescence in-situ hybridization, microarrays, next-generation sequencing, and mass spectrometry, point-of-care MDx platforms are drawing particular interest due to their low cost, robustness, and wide application. This dissertation develops a novel MDx technology platform capable of high target amplification and detection performance. For nucleic acid target detection, we fabricate an array of electron-beam-patterned microgels on a standard glass microscope slide. The microgels can be as small as a few hundred nanometers. The unique way of energy deposition during electron-beam lithography provides the microgels with a very diffuse water -gel interface that enables them to not only serve as substrates to immobilize DNA probes but do so while preserving them in a highly hydrated environment that optimizes their performance. Benefiting from the high spatial resolution provided by such techniques as position-sensitive microspotting and dip-pen nanolithography, multiple oligonucleotide probes known as molecular beacons (MBs) can be patterned on microgels. Furthermore, nucleic acid target amplification can be conducted in direct contact with the microgel-tethered detection array. Specifically, we use an isothermal RNA amplification reaction - nucleic acid sequence-based amplification (NASBA). ssRNA amplicons of from the NASBA reaction can directly hybridize with microgel-tethered MBs, and the

  8. Nanoconstructions Based on Spatially Ordered Nucleic Acid Molecules

    NASA Astrophysics Data System (ADS)

    Yevdokimov, Yu. M.

    Different strategies for the design of nanoconstructions whose building blocks are both linear molecules of double-stranded nucleic acids and nucleic acid molecules fixed in the spatial structure of particles of liquid-crystalline dispersions are described.

  9. Acid-base transport by the renal proximal tubule

    PubMed Central

    Skelton, Lara A.; Boron, Walter F.; Zhou, Yuehan

    2015-01-01

    Each day, the kidneys filter 180 L of blood plasma, equating to some 4,300 mmol of the major blood buffer, bicarbonate (HCO3−). The glomerular filtrate enters the lumen of the proximal tubule (PT), and the majority of filtered HCO3− is reclaimed along the early (S1) and convoluted (S2) portions of the PT in a manner coupled to the secretion of H+ into the lumen. The PT also uses the secreted H+ to titrate non-HCO3− buffers in the lumen, in the process creating “new HCO3−” for transport into the blood. Thus, the PT – along with more distal renal segments – is largely responsible for regulating plasma [HCO3−]. In this review we first focus on the milestone discoveries over the past 50+ years that define the mechanism and regulation of acid-base transport by the proximal tubule. Further on in the review, we will summarize research still in progress from our laboratory, work that addresses the problem of how the PT is able to finely adapt to acid–base disturbances by rapidly sensing changes in basolateral levels of HCO3− and CO2 (but not pH), and thereby to exert tight control over the acid–base composition of the blood plasma. PMID:21170887

  10. Methylene-bis[(aminomethyl)phosphinic acids]: synthesis, acid-base and coordination properties.

    PubMed

    David, Tomáš; Procházková, Soňa; Havlíčková, Jana; Kotek, Jan; Kubíček, Vojtěch; Hermann, Petr; Lukeš, Ivan

    2013-02-21

    Three symmetrical methylene-bis[(aminomethyl)phosphinic acids] bearing different substituents on the central carbon atom, (NH(2)CH(2))PO(2)H-C(R(1))(R(2))-PO(2)H(CH(2)NH(2)) where R(1) = OH, R(2) = Me (H(2)L(1)), R(1) = OH, R(2) = Ph (H(2)L(2)) and R(1),R(2) = H (H(2)L(3)), were synthesized. Acid-base and complexing properties of the ligands were studied in solution as well as in the solid state. The ligands show unusually high basicity of the nitrogen atoms (log K(1) = 9.5-10, log K(2) = 8.5-9) if compared with simple (aminomethyl)phosphinic acids and, consequently, high stability constants of the complexes with studied divalent metal ions. The study showed the important role of the hydroxo group attached to the central carbon atom of the geminal bis(phosphinate) moiety. Deprotonation of the hydroxo group yields the alcoholate anion which tends to play the role of a bridging ligand and induces formation of polynuclear complexes. Solid-state structures of complexes [H(2)N=C(NH(2))(2)][Cu(2)(H(-1)L(2))(2)]CO(3)·10H(2)O and Li(2)[Co(4)(H(-1)L(1))(3)(OH)]·17.5H(2)O were determined by X-ray diffraction. The complexes show unexpected geometries forming dinuclear and cubane-like structures, respectively. The dinuclear copper(II) complex contains a bridging μ(2)-alcoholate group with the (-)O-P(=O)-CH(2)-NH(2) fragments of each ligand molecule chelated to the different central ion. In the cubane cobalt(II) complex, one μ(3)-hydroxide and three μ(3)-alcoholate anions are located in the cube vertices and both phosphinate groups of one ligand molecule are chelating the same cobalt(II) ion while each of its amino groups are bound to different neighbouring metal ions. All such three metal ions are bridged by the alcoholate group of a given ligand.

  11. Science review: quantitative acid-base physiology using the Stewart model.

    PubMed

    Wooten, E Wrenn

    2004-12-01

    There has been renewed interest in quantifying acid-base disorders in the intensive care unit. One of the methods that has become increasingly used to calculate acid-base balance is the Stewart model. This model is briefly discussed in terms of its origin, its relationship to other methods such as the base excess approach, and the information it provides for the assessment and treatment of acid-base disorders in critically ill patients.

  12. An Extended Normalization Model of Attention Accounts for Feature-Based Attentional Enhancement of Both Response and Coherence Gain

    PubMed Central

    Krishna, B. Suresh; Treue, Stefan

    2016-01-01

    Paying attention to a sensory feature improves its perception and impairs that of others. Recent work has shown that a Normalization Model of Attention (NMoA) can account for a wide range of physiological findings and the influence of different attentional manipulations on visual performance. A key prediction of the NMoA is that attention to a visual feature like an orientation or a motion direction will increase the response of neurons preferring the attended feature (response gain) rather than increase the sensory input strength of the attended stimulus (input gain). This effect of feature-based attention on neuronal responses should translate to similar patterns of improvement in behavioral performance, with psychometric functions showing response gain rather than input gain when attention is directed to the task-relevant feature. In contrast, we report here that when human subjects are cued to attend to one of two motion directions in a transparent motion display, attentional effects manifest as a combination of input and response gain. Further, the impact on input gain is greater when attention is directed towards a narrow range of motion directions than when it is directed towards a broad range. These results are captured by an extended NMoA, which either includes a stimulus-independent attentional contribution to normalization or utilizes direction-tuned normalization. The proposed extensions are consistent with the feature-similarity gain model of attention and the attentional modulation in extrastriate area MT, where neuronal responses are enhanced and suppressed by attention to preferred and non-preferred motion directions respectively. PMID:27977679

  13. Guanine base stacking in G-quadruplex nucleic acids

    PubMed Central

    Lech, Christopher Jacques; Heddi, Brahim; Phan, Anh Tuân

    2013-01-01

    G-quadruplexes constitute a class of nucleic acid structures defined by stacked guanine tetrads (or G-tetrads) with guanine bases from neighboring tetrads stacking with one another within the G-tetrad core. Individual G-quadruplexes can also stack with one another at their G-tetrad interface leading to higher-order structures as observed in telomeric repeat-containing DNA and RNA. In this study, we investigate how guanine base stacking influences the stability of G-quadruplexes and their stacked higher-order structures. A structural survey of the Protein Data Bank is conducted to characterize experimentally observed guanine base stacking geometries within the core of G-quadruplexes and at the interface between stacked G-quadruplex structures. We couple this survey with a systematic computational examination of stacked G-tetrad energy landscapes using quantum mechanical computations. Energy calculations of stacked G-tetrads reveal large energy differences of up to 12 kcal/mol between experimentally observed geometries at the interface of stacked G-quadruplexes. Energy landscapes are also computed using an AMBER molecular mechanics description of stacking energy and are shown to agree quite well with quantum mechanical calculated landscapes. Molecular dynamics simulations provide a structural explanation for the experimentally observed preference of parallel G-quadruplexes to stack in a 5′–5′ manner based on different accessible tetrad stacking modes at the stacking interfaces of 5′–5′ and 3′–3′ stacked G-quadruplexes. PMID:23268444

  14. Thermochemical study of the reactions of acid-base interaction in an aqueous solution of α-aminobutyric acid

    NASA Astrophysics Data System (ADS)

    Lytkin, A. I.; Chernikov, V. V.; Krutova, O. N.; Skvortsov, I. A.; Korchagina, A. S.

    2017-01-01

    The heat effects of the interaction between a solution of α-aminobutyric acid and solutions of HNO3 and KOH are measured by means of calorimetry in different ranges of pH at 298.15 K and values of ionic strength of 0.25, 0.5, and 0.75 (KNO3). The heat effects of the stepwise dissociation of the amino acid are determined. Standard thermodynamic characteristics (Δr H 0, Δr G 0, and Δr S 0) of the reactions of acid-base interaction in aqueous solutions of α-aminobutyric acid are calculated. The connection between the thermodynamic characteristics of the dissociation of the amino acid and the structure of this compound is considered.

  15. Solution influence on biomolecular equilibria - Nucleic acid base associations

    NASA Technical Reports Server (NTRS)

    Pohorille, A.; Pratt, L. R.; Burt, S. K.; Macelroy, R. D.

    1984-01-01

    Various attempts to construct an understanding of the influence of solution environment on biomolecular equilibria at the molecular level using computer simulation are discussed. First, the application of the formal statistical thermodynamic program for investigating biomolecular equilibria in solution is presented, addressing modeling and conceptual simplications such as perturbative methods, long-range interaction approximations, surface thermodynamics, and hydration shell. Then, Monte Carlo calculations on the associations of nucleic acid bases in both polar and nonpolar solvents such as water and carbon tetrachloride are carried out. The solvent contribution to the enthalpy of base association is positive (destabilizing) in both polar and nonpolar solvents while negative enthalpies for stacked complexes are obtained only when the solute-solute in vacuo energy is added to the total energy. The release upon association of solvent molecules from the first hydration layer around a solute to the bulk is accompanied by an increase in solute-solvent energy and decrease in solvent-solvent energy. The techniques presented are expectd to displace less molecular and more heuristic modeling of biomolecular equilibria in solution.

  16. Ligation with nucleic acid sequence-based amplification.

    PubMed

    Ong, Carmichael; Tai, Warren; Sarma, Aartik; Opal, Steven M; Artenstein, Andrew W; Tripathi, Anubhav

    2012-01-01

    This work presents a novel method for detecting nucleic acid targets using a ligation step along with an isothermal, exponential amplification step. We use an engineered ssDNA with two variable regions on the ends, allowing us to design the probe for optimal reaction kinetics and primer binding. This two-part probe is ligated by T4 DNA Ligase only when both parts bind adjacently to the target. The assay demonstrates that the expected 72-nt RNA product appears only when the synthetic target, T4 ligase, and both probe fragments are present during the ligation step. An extraneous 38-nt RNA product also appears due to linear amplification of unligated probe (P3), but its presence does not cause a false-positive result. In addition, 40 mmol/L KCl in the final amplification mix was found to be optimal. It was also found that increasing P5 in excess of P3 helped with ligation and reduced the extraneous 38-nt RNA product. The assay was also tested with a single nucleotide polymorphism target, changing one base at the ligation site. The assay was able to yield a negative signal despite only a single-base change. Finally, using P3 and P5 with longer binding sites results in increased overall sensitivity of the reaction, showing that increasing ligation efficiency can improve the assay overall. We believe that this method can be used effectively for a number of diagnostic assays.

  17. Secretion of acid and base equivalents by intact distal airways.

    PubMed

    Inglis, S K; Wilson, S M; Olver, R E

    2003-05-01

    Secretion of HCO(3)(-) by airway submucosal glands is essential for normal liquid and mucus secretion. Because the liquid bathing the airway surface (ASL) is acidic, it has been proposed that the surface epithelium may acidify HCO(3)(-)-rich glandular fluid. The aim of this study was to investigate the mechanisms by which intact distal bronchi, which contain both surface and glandular epithelium, modify pH of luminal fluid. Distal bronchi were isolated from pig lungs, cannulated in a bath containing HCO(3)(-)-buffered solution, and perfused continually with an aliquot of similar, lightly buffered solution (LBS) in which NaCl replaced NaHCO(3)(-) (pH 7 with NaOH). The pH of this circulating LBS initially acidified (by 0.053 +/- 0.0053 pH units) and transepithelial potential difference (PD) depolarized. The magnitude of acidification was increased when pH(LBS) was higher. This acidification was unaffected by luminal dimethylamiloride (DMA, 100 microM) but was inhibited by 100 nM bafilomycin A(1) (by 76 +/- 13%), suggesting involvement of vacuolar-H(+) ATPase. Addition of ACh (10 microM) evoked alkalinization of luminal LBS and hyperpolarization of transepithelial PD. The alkalinization was inhibited in HCO(3)(-)-free solutions containing acetazolamide (1 mM) and by DMA and was enhanced by bumetanide (100 microM), an inhibitor of Cl(-) secretion. The hyperpolarization was unaffected by these maneuvers. The anion channel blocker 5-nitro-2-(3-phenylpropylamino)benzoate (300 microM) and combined treatment with DMA and bumetanide blocked both the alkalinization and hyperpolarization responses to ACh. These results are consistent with earlier studies showing that ACh evokes glandular secretion of HCO(3)(-) and Cl(-). Isolated distal airways thus secrete both acid and base equivalents.

  18. Electrospun poly(lactic acid) based conducting nanofibrous networks

    NASA Astrophysics Data System (ADS)

    Patra, S. N.; Bhattacharyya, D.; Ray, S.; Easteal, A. J.

    2009-08-01

    Multi-functionalised micro/nanostructures of conducting polymers in neat or blended forms have received much attention because of their unique properties and technological applications in electrical, magnetic and biomedical devices. Biopolymer-based conducting fibrous mats are of special interest for tissue engineering because they not only physically support tissue growth but also are electrically conductive, and thus are able to stimulate specific cell functions or trigger cell responses. They are effective for carrying current in biological environments and can thus be considered for delivering local electrical stimuli at the site of damaged tissue to promote wound healing. Electrospinning is an established way to process polymer solutions or melts into continuous fibres with diameter often in the nanometre range. This process primarily depends on a number of parameters, including the type of polymer, solution viscosity, polarity and surface tension of the solvent, electric field strength and the distance between the spinneret and the collector. The present research has included polyaniline (PANi) as the conducting polymer and poly(L-lactic acid) (PLLA) as the biopolymer. Dodecylbenzene sulphonic acid (DBSA) doped PANi and PLLA have been dissolved in a common solvent (mixtures of chloroform and dimethyl formamide (DMF)), and the solutions successfully electrospun. DMF enhanced the dielectric constant of the solvent, and tetra butyl ammonium bromide (TBAB) was used as an additive to increase the conductivity of the solution. DBSA-doped PANi/PLLA mat exhibits an almost bead-free network of nanofibres that have extraordinarily smooth surface and diameters in the range 75 to 100 nm.

  19. Integrated Microfluidic System Based on Electrowetting and its Application to Amino Acid Sensing Based on Electrochemiluminescence

    NASA Astrophysics Data System (ADS)

    Hosono, Hiroki; Satoh, Wataru; Suzuki, Hiroaki

    A microfluidic system to transport and mix solutions was fabricated and used for the detection of amino acids. A solution filled in the injection port was transported through a space between an elongated gold working electrode and a protruding structure of polydimethylsiloxane (PDMS). The transport was possible because the electrode surface was made hydrophilic by changing the potential of the gold working electrode. The same principle was used to mix two solutions. To demonstrate the system's applicability, optical biosensing based on electrochemiluminescence (ECL) was conducted on the chip. A necessary reagent solution (Ru(bpy)32+) and a sample solution (amino acid) were transported and mixed. ECL was observed on a platinum working electrode by applying a positive potential. Linear relationships were observed between the ECL intensity and the amino acid concentration.

  20. Effect of casein-based semi-synthetic food on renal acid excretion and acid-base state of blood in dogs.

    PubMed

    Zijlstra, W G; Langbroek, A J; Kraan, J; Rispens, P; Nijmeijer, A

    1995-01-01

    Urinary acid excretion and blood acid-base state were determined in dogs fed a casein-based semi-synthetic food (SSF), to which different amounts of salts had been added, in comparison with feeding normal dog food. Net acid excretion (NAE) and inorganic acid excretion (IAE) increased during SSF feeding. IAE was higher than the acid load calculated from the sulphur and phosphorus content of the casein. This higher IAE appeared to be due to the presence of calcium and magnesium phosphate in the diet, because calcium and magnesium may be in part precipitated as carbonate, leaving phosphate to be absorbed as phosphoric acid. Acid excretion decreased by addition of CaO. When no neutral Na+ and K+ salts were added, the increase in NAE was accompanied by a metabolic acidosis. K+ was more effective in attenuating the acidosis than Na+. On the basis of these findings a diet can be made which imposes a known acid load, and provides stable baseline values. Hence, any additions that influence the acid-base balance can be properly studied. The data obtained in these and future studies utilising this diet may be of help in optimising the composition of nutrient solutions to be used in the care of critically ill patients.

  1. RESULTS FROM A DEMONSTRATION OF RF-BASED UF6 CYLINDER ACCOUNTING AND TRACKING SYSTEM INSTALLED AT A USEC FACILITY

    SciTech Connect

    Pickett, Chris A; Kovacic, Donald N; Morgan, Jim; Younkin, James R; Carrick, Bernie; Ken, Whittle; Johns, R E

    2008-09-01

    add tamper-indicating and data authentication features to some of the pertinent system components. Future efforts will focus on these needs along with implementing protocols relevant to IAEA safeguards. The work detailed in this report demonstrates the feasibility of constructing RF devices that can survive the operational rigors associated with the transportation, storage, and processing of UF6 cylinders. The system software specially designed for this project is called Cylinder Accounting and Tracking System (CATS). This report details the elements of the CATS rules-based architecture and its use in safeguards-monitoring and asset-tracking applications. Information is also provided on improvements needed to make the technology ready, as well as options for improving the safeguards aspects of the technology. The report also includes feedback from personnel involved in the testing, as well as individuals who could utilize an RF-based system in supporting the performance of their work. The system software was set up to support a Mailbox declaration, where a declaration can be made either before or after cylinder movements take place. When the declaration is made before cylinders move, the operators must enter this information into CATS. If the IAEA then shows up unexpectedly at the facility, they can see how closely the operational condition matches the declaration. If the declaration is made after the cylinders move, this provides greater operational flexibility when schedules are interrupted or are changed, by allowing operators to declare what moves have been completed. The IAEA can then compare where cylinders are with where CATS or the system says they are located. The ability of CATS to automatically generate Mailbox declarations is seen by the authors as a desirable feature. The Mailbox approach is accepted by the IAEA but has not been widely implemented (and never in enrichment facilities). During the course of this project, we have incorporated alternative

  2. A risk index for pediatric patients undergoing diagnostic imaging with 99mTc-dimercaptosuccinic acid that accounts for body habitus

    NASA Astrophysics Data System (ADS)

    O'Reilly, Shannon E.; Plyku, Donika; Sgouros, George; Fahey, Frederic H.; Treves, S. Ted; Frey, Eric C.; Bolch, Wesley E.

    2016-03-01

    Published guidelines for administered activity to pediatric patients undergoing diagnostic nuclear medicine imaging are currently obtained through expert consensus of the minimum values as a function of body weight as required to yield diagnostic quality images. We have previously shown that consideration of body habitus is also important in obtaining diagnostic quality images at the lowest administered activity. The objective of this study was to create a series of computational phantoms that realistically portray the anatomy of the pediatric patient population which can be used to develop and validate techniques to minimize radiation dose while maintaining adequate image quality. To achieve this objective, we have defined an imaging risk index that may be used in future studies to develop pediatric patient dosing guidelines. A population of 48 hybrid phantoms consisting of non-uniform B-spline surfaces and polygon meshes was generated. The representative ages included the newborn, 1 year, 5 year, 10 year and 15 year male and female. For each age, the phantoms were modeled at their 10th, 50th, and 90th height percentile each at a constant 50th weight percentile. To test the impact of kidney size, the newborn phantoms were modeled with the following three kidney volumes:  -15%, average, and  +15%. To illustrate the impact of different morphologies on dose optimization, we calculated the effective dose for each phantom using weight-based 99mTc-DMSA activity administration. For a given patient weight, body habitus had a considerable effect on effective dose. Substantial variations were observed in the risk index between the 10th and 90th percentile height phantoms from the 50th percentile phantoms for a given age, with the greatest difference being 18%. There was a dependence found between kidney size and risk of radiation induced kidney cancer, with the highest risk indices observed in newborns with the smallest kidneys. Overall, the phantoms and techniques

  3. Sensitivity analysis of laboratory based mine overburden analytical techniques for the prediction of acidic mine drainage. Final report

    SciTech Connect

    Bradham, W.S.; Caruccio, F.T.

    1995-09-01

    A three part sensitivity analysis was conducted to evaluate commonly used mine overburden analytical techniques. The primary objectives of the study were: identify and evaluate the effects of variability in mine overburden geochemistry, as measured by pyrite weight percent and neutralization potential (NP), on variability of contaminant production; determine which acid/base accounting interpretation technique best predicts both qualitative and quantitative leachate quality in laboratory analytical testing; and identify the predominant factors of weathering cells, soxhlet extraction, and column leaching tests, and evaluate variability of contaminant production due to variations in; storage conditions, leachant temperature, particle size, particle sorting efficiency, and leaching interval.

  4. An elementary derivation of the hard/soft-acid/base principle.

    PubMed

    Ayers, Paul W

    2005-04-08

    The hard/soft-acid/base (HSAB) principle indicates that hard acids prefer binding to hard bases (often forming bonds with substantial ionic character) while soft acids prefer binding to soft bases (often forming bonds with substantial covalent character). Though the HSAB principle is a foundational concept of the modern theory of acids and bases, the theoretical underpinnings of the HSAB principle remain murky. This paper examines the exchange reaction, wherein two molecules, one the product of reacting a hard acid and a soft base and the other the product of reacting a soft acid with a hard base, exchange substituents to form the preferred hard-hard and soft-soft product. A simple derivation shows that this reaction is exothermic, proving the validity of the HSAB principle. The analysis leads to the simple and conceptually appealing conclusion that the HSAB principle is a driven by simple electron transfer effects.

  5. Ultrastructural observation of the acid-base resistant zone of all-in-one adhesives using three different acid-base challenges.

    PubMed

    Tsujimoto, Miho; Nikaido, Toru; Inoue, Go; Sadr, Alireza; Tagami, Junji

    2010-11-01

    The aim of this study was to analyze the ultrastructure of the dentin-adhesive interface using two all-in-one adhesive systems (Clearfil Tri-S Bond, TB; Tokuyama Bond Force, BF) after different acid-base challenges. Three solutions were used as acidic solutions for the acid-base challenges: a demineralizing solution (DS), a phosphoric acid solution (PA), and a hydrochloric acid solution (HCl). After the acid-base challenges, the bonded interfaces were examined by scanning electron microscopy. Thickness of the acid-base resistant zone (ABRZ) created in PA and HCl was thinner than in DS for both adhesive systems. For BF adhesive, an eroded area was observed beneath the ABRZ after immersion in PA and HCl, but not in DS. Conversely for TB adhesive, the eroded area was observed only after immersion in PA. In conclusion, although the ABRZ was observed for both all-in-one adhesive systems, its morphological features were influenced by the ingredients of both the adhesive material and acidic solution.

  6. An energy-based model accounting for snow accumulation and snowmelt in a coniferous forest and in an open area

    NASA Astrophysics Data System (ADS)

    Matějka, Ondřej; Jeníček, Michal

    2016-04-01

    An energy balance approach was used to simulate snow water equivalent (SWE) evolution in an open area, forest clearing and coniferous forest during winter seasons 2011/12 and 2012/13 in the Bystřice River basin (Krušné Mountains, Czech Republic). The aim was to describe the impact of vegetation on snow accumulation and snowmelt under different forest canopy structure and trees density. Hemispherical photographs were used to describe the forest canopy structure. Energy balance model of snow accumulation and melt was set up. The snow model was adjusted to account the effects of forest canopy on driving meteorological variables. Leaf area index derived from 32 hemispherical photographs of vegetation and sky was used to implement the forest influence in the snow model. The model was evaluated using snow depth and SWE data measured at 16 localities in winter seasons from 2011 to 2013. The model was able to reproduce the SWE evolution in both winter seasons beneath the forest canopy, forest clearing and open area. The SWE maximum in forest sites was by 18% lower than in open areas and forest clearings. The portion of shortwave radiation on snowmelt rate was by 50% lower in forest areas than in open areas due to shading effect. The importance of turbulent fluxes was by 30% lower in forest sites compared to openings because of wind speed reduction up to 10% of values at corresponding open areas. Indirect estimation of interception rates was derived. Between 14 and 60% of snowfall was intercept and sublimated in the forest canopy in both winter seasons. Based on model results, the underestimation of solid precipitation (heated precipitation gauge used for measurement) at the weather station Hřebečná was revealed. The snowfall was underestimated by 40% in winter season 2011/12 and by 13% in winter season 2012/13. Although, the model formulation appeared sufficient for both analysed winter seasons, canopy effects on the longwave radiation and ground heat flux were not

  7. [Detection of amino acids based on terahertz spectroscopy].

    PubMed

    Tang, Zhong-feng; Lin, Hai-tao; Chen, Xiao-wei; Zhang, Zeng-fang

    2009-09-01

    Terahertz (THz) is the frequency region ranging from 0.1 to 2.0 THz, which lies in the far-infrared region. Compared to Fourier transform infrared spectra (FTIR), terahertz time-domain spectra (THz-TDS) has low energy, high signal-to-noise ratio (SNR) and is non-ionizing radiation. Low-frequency vibrational modes of some amino acids, such as torsional and collective vibrational modes and hydrogen-bond modes, exist in the THz region. Amino acids are important organic compounds and are the fundamental components of proteins. Amino acids can exist with a highly ordered crystal structure linked by hydrogen intermolecular bonds in the solid phase. The absorption spectra of amino acids in the THz region show marked differences while mid-infrared absorption spectra usually show very little difference. Up to now, absorption spectra of twenty kinds of amino acids have been studied by many researchers using THz technique; the quantitative analysis of amino acids by THZ-TDS is also included. Investigation of THz spectra of amino acids are of fundamental interests, and will lead to further understanding of low-frequency vibrations of protein/DNA and relevant biological reactions and activities. In the present paper, the latest progress in absorption spectra of amino acids determined by THz spectroscopy is reviewed and a database is built. Some brief remarks on future developments in and prospects for THz application in amino acids are also provided.

  8. Using problem based learning and guided inquiry in a high school acid-base chemistry unit

    NASA Astrophysics Data System (ADS)

    McKinley, Katie

    The purpose of this investigation was to determine if incorporating problem based learning and guided inquiry would improve student achievement in an acid base unit for high school chemistry. The activities and labs in the unit were modified to be centered around the problem of a fish kill that students investigated. Students also participated in guided inquiry labs to increase the amount of critical thinking and problem solving being done in the classroom. The hypothesis was that the implementation of problem based learning and guided inquiry would foster student learning. Students took a pre-test and post-test on questions covering the objectives of the acid base unit. These assessments were compared to determine the effectiveness of the unit. The results indicate that the unit was effective in increasing student performance on the unit test. This study also analyzed the process of problem based learning. Problem based learning can be an effective method of engaging students in inquiry. However, designing an effective problem based learning unit requires careful design of the problem and enough structure to assure students learn the intended content.

  9. Hands-On Science: Is It an Acid or a Base? These Colorful Tests Tell All!

    ERIC Educational Resources Information Center

    VanCleave, Janice

    1998-01-01

    Two hands-on science activities for K-6 students teach them how to determine if something is an acid or a base. The activities require acid/base indicator juice, testing strips, and a base solution. A recipe for making them in the classroom using red cabbage and baking soda is provided. (SM)

  10. A Comparison of Different Teaching Designs of "Acids and Bases" Subject

    ERIC Educational Resources Information Center

    Ültay, Neslihan; Çalik, Muammer

    2016-01-01

    Inability to link the acid-base concepts with daily life phenomena (as contexts) highlights the need for further research on the context-based acid-base chemistry. In this vein, the aim of this study is to investigate the effects of different teaching designs (REACT strategy, 5Es learning model and traditional (existing) instruction) relevant with…

  11. Evaluation of the number of ionogenic groups of inulinase by acid-base titration.

    PubMed

    Kovaleva, T A; Holyavka, M G; Rezvan, S G; Kozhedub, S V

    2008-06-01

    Acid base titration showed that Aspergillus awamori inulinase includes 178 asparaginic and glutamic acid residues, 20 histidine, 10 serine, and 34 lysine and tyrosine residues. Denaturation temperature for this enzyme was calculated using analysis of the proportion of stabilizing and destabilizing amino acids in the molecule.

  12. A Virtual World Case Study--Quality, Social Justice, and Accountability in a Simulation-Based Educational Environment

    ERIC Educational Resources Information Center

    Stockton, Susan; McNeeley, Terry

    2015-01-01

    This paper examines the application of quality, social justice/equality and accountability/responsibility of teaching and learning in an online educational environment. Components addressed in this paper include a brief inspection of online teaching and learning methods, qualities of online teaching and learning, and the responsibility of teaching…

  13. On the Problem-Size Effect in Small Additions: Can We Really Discard Any Counting-Based Account?

    ERIC Educational Resources Information Center

    Barrouillet, Pierre; Thevenot, Catherine

    2013-01-01

    The problem-size effect in simple additions, that is the increase in response times (RTs) and error rates with the size of the operands, is one of the most robust effects in cognitive arithmetic. Current accounts focus on factors that could affect speed of retrieval of the answers from long-term memory such as the occurrence of interference in a…

  14. Recasting the Vision for Achieving Equity: A Historical Analysis of Testing and Impediments to Process-Based Accountability

    ERIC Educational Resources Information Center

    Walker, T. Anthony

    2017-01-01

    This article explores past and current education testing frameworks as a pretext for constructing a policy platform with the efficacy to transform systems and structures that hinder opportunities and resist equitable practices. The rise of accountability in education public policy has brought about intended and unintended outcomes. As prescribed,…

  15. Content-Based Instruction in the Teaching of English for Accounting at Vietnamese College of Finance and Customs

    ERIC Educational Resources Information Center

    Ngan, Nguyen Thi Chau

    2011-01-01

    The overwhelming weight of emphasis in language analysis in the teaching of English for Accounting (ESP) has been a concern for teachers of English at the College of Finance and Customs (CFC). In the ESP course, the teaching materials teach students to recognize the surface form by means of the specialist texts. The difficulties the students and…

  16. An Operator Perspective from a Facility Evaluation of an RFID-Based UF6 Cylinder Accounting and Tracking System

    SciTech Connect

    Martyn, Rose; Fitzgerald, Peter; Stehle, Nicholas D; Rowe, Nathan C; Younkin, James R

    2011-01-01

    An operational field test of a Radio-Frequency Identification (RFID) system for tracking and accounting UF6 cylinders was conducted at the Global Nuclear Fuel Americas (GNF) fuel fabrication plant in 2009. The Cylinder Accountability and Tracking System (CATS) was designed and deployed by Oak Ridge National Laboratory (ORNL) and evaluated in cooperation with GNF. The system required that passive RFID be attached to several UF6 30B cylinders as they were received at the site; then the cylinders were tracked as they proceeded to interim storage, to processing in an autoclave, and eventually to disposition from the site. This CATS deployment also provided a direct integration of scale data from the site accountability scales. The integration of this information into the tracking data provided an attribute for additional safeguards for evaluation. The field test provided insight into the advantages and challenges of using RFID at an operating nuclear facility. The RFID system allowed operators to interact with the technology and demonstrated the survivability of the tags and reader equipment in the process environment. This paper will provide the operator perspective on utilizing RFID technology for locating cylinders within the facility, thereby tracking the cylinders for process and for Material Control & Accounting functions. The paper also will present the operator viewpoint on RFID implemented as an independent safeguards system.

  17. Model Accounting Program. Adopters Guide.

    ERIC Educational Resources Information Center

    Beaverton School District 48, OR.

    The accounting cluster demonstration project conducted at Aloha High School in the Beaverton, Oregon, school district developed a model curriculum for high school accounting. The curriculum is based on interviews with professionals in the accounting field and emphasizes the use of computers. It is suitable for use with special needs students as…

  18. Continuous monitoring of the zinc-phosphate acid-base cement setting reaction by proton nuclear magnetic relaxation

    NASA Astrophysics Data System (ADS)

    Apih, T.; Lebar, A.; Pawlig, O.; Trettin, R.

    2001-06-01

    Proton nuclear magnetic relaxation is a well-established technique for continuous and non destructive monitoring of hydration of conventional Portland building cements. Here, we demonstrate the feasibility of nuclear magnetic resonance (NMR) monitoring of the setting reaction of zinc-phosphate acid-base dental cements, which harden in minutes as compared to days, as in the case of Portland cements. We compare the setting of cement powder (mainly, zinc oxide) prepared with clinically used aluminum-modified orthophosphoric acid solution with the setting of a model system where cement powder is mixed with pure orthophosphoric acid solution. In contrast to previously published NMR studies of setting Portland cements, where a decrease of spin-lattice relaxation time is attributed to enhanced relaxation at the growing internal surface, spin-lattice relaxation time T1 increases during the set of clinically used zinc-phosphate cement. Comparison of these results with a detailed study of diffusion, viscosity, and magnetic-field dispersion of T1 in pure and aluminum-modified orthophosphoric acid demonstrates that the increase of T1 in the setting cement is connected with the increase of molecular mobility in the residual phosphoric acid solution. Although not taken into account so far, such effects may also significantly influence the relaxation times in setting Portland cements, particularly when admixtures with an effect on water viscosity are used.

  19. Improving pharmacy students' understanding and long-term retention of acid-base chemistry.

    PubMed

    Roche, Victoria F

    2007-12-15

    Despite repeated exposure to the principles underlying the behavior of organic acids and bases in aqueous solution, some pharmacy students remain confused about the topic of acid-base chemistry. Since a majority of organic drug molecules have acid-base character, the ability to predict their reactivity and the extent to which they will ionize in a given medium is paramount to students' understanding of essentially all aspects of drug action in vivo and in vitro. This manuscript presents a medicinal chemistry lesson in the fundamentals of acid-base chemistry that many pharmacy students have found enlightening and clarifying.

  20. Teaching Brønsted-Lowry Acid-Base Theory in a Direct Comprehensive Way

    NASA Astrophysics Data System (ADS)

    Adcock, Jamie L.

    2001-11-01

    A figure is presented which shows in a comprehensive way the relationships between Brønsted-Lowry acids and their conjugate bases. It shows their interactions with water and quantifies the terms strong, weak, and very weak, showing precisely how these modifiers can be effectively used to indicate the nature of the reaction between any conjugate acid/base and water. It shows that ion hydrolysis is simple acid/base behavior, and it clearly suggests the leveling effect of water on strong acids and bases.

  1. Improving Pharmacy Students' Understanding and Long-term Retention of Acid-Base Chemistry

    PubMed Central

    2007-01-01

    Despite repeated exposure to the principles underlying the behavior of organic acids and bases in aqueous solution, some pharmacy students remain confused about the topic of acid-base chemistry. Since a majority of organic drug molecules have acid-base character, the ability to predict their reactivity and the extent to which they will ionize in a given medium is paramount to students' understanding of essentially all aspects of drug action in vivo and in vitro. This manuscript presents a medicinal chemistry lesson in the fundamentals of acid-base chemistry that many pharmacy students have found enlightening and clarifying PMID:19503706

  2. Hyaluronic Acid Based Hydrogels for Regenerative Medicine Applications

    PubMed Central

    Borzacchiello, Assunta; Russo, Luisa; Malle, Birgitte M.; Schwach-Abdellaoui, Khadija; Ambrosio, Luigi

    2015-01-01

    Hyaluronic acid (HA) hydrogels, obtained by cross-linking HA molecules with divinyl sulfone (DVS) based on a simple, reproducible, and safe process that does not employ any organic solvents, were developed. Owing to an innovative preparation method the resulting homogeneous hydrogels do not contain any detectable residual cross-linking agent and are easier to inject through a fine needle. HA hydrogels were characterized in terms of degradation and biological properties, viscoelasticity, injectability, and network structural parameters. They exhibit a rheological behaviour typical of strong gels and show improved viscoelastic properties by increasing HA concentration and decreasing HA/DVS weight ratio. Furthermore, it was demonstrated that processes such as sterilization and extrusion through clinical needles do not imply significant alteration of viscoelastic properties. Both SANS and rheological tests indicated that the cross-links appear to compact the network, resulting in a reduction of the mesh size by increasing the cross-linker amount. In vitro degradation tests of the HA hydrogels demonstrated that these new hydrogels show a good stability against enzymatic degradation, which increases by increasing HA concentration and decreasing HA/DVS weight ratio. Finally, the hydrogels show a good biocompatibility confirmed by in vitro tests. PMID:26090451

  3. [Development of Nucleic Acid-Based Adjuvant for Cancer Immunotherapy].

    PubMed

    Kobiyama, Kouji; Ishii, Ken J

    2015-09-01

    Since the discovery of the human T cell-defined tumor antigen, the cancer immunotherapy field has rapidly progressed, with the research and development of cancer immunotherapy, including cancer vaccines, being conducted actively. However, the disadvantages of most cancer vaccines include relatively weak immunogenicity and immune escape or exhaustion. Adjuvants with innate immunostimulatory activities have been used to overcome these issues, and these agents have been shown to enhance the immunogenicity of cancer vaccines and to act as mono-therapeutic anti-tumor agents. CpG ODN, an agonist for TLR9, is one of the promising nucleic acid-based adjuvants, and it is a potent inducer of innate immune effector functions. CpG ODN suppresses tumor growth in the absence of tumor antigens and peptide administration. Therefore, CpG ODN is expected to be useful as a cancer vaccine adjuvant as well as a cancer immunotherapy agent. In this review, we discuss the potential therapeutic applications and mechanisms of CpG ODN for cancer immunotherapy.

  4. Regulation of Connexin-Based Channels by Fatty Acids.

    PubMed

    Puebla, Carlos; Retamal, Mauricio A; Acuña, Rodrigo; Sáez, Juan C

    2017-01-01

    In this mini-review, we briefly summarize the current knowledge about the effects of fatty acids (FAs) on connexin-based channels, as well as discuss the limited information about the impact FAs may have on pannexins (Panxs). FAs regulate diverse cellular functions, some of which are explained by changes in the activity of channels constituted by connexins (Cxs) or Panxs, which are known to play critical roles in maintaining the functional integrity of diverse organs and tissues. Cxs are transmembrane proteins that oligomerize into hexamers to form hemichannels (HCs), which in turn can assemble into dodecamers to form gap junction channels (GJCs). While GJCs communicate the cytoplasm of contacting cells, HCs serve as pathways for the exchange of ions and small molecules between the intra and extracellular milieu. Panxs, as well as Cx HCs, form channels at the plasma membrane that enable the interchange of molecules between the intra and extracellular spaces. Both Cx- and Panx-based channels are controlled by several post-translational modifications. However, the mechanism of action of FAs on these channels has not been described in detail. It has been shown however that FAs frequently decrease GJC-mediated cell-cell communication. The opposite effect also has been described for HC or Panx-dependent intercellular communication, where, the acute FA effect can be reversed upon washout. Additionally, changes in GJCs mediated by FAs have been associated with post-translational modifications (e.g., phosphorylation), and seem to be directly related to chemical properties of FAs (e.g., length of carbon chain and/or degree of saturation), but this possible link remains poorly understood.

  5. Regulation of Connexin-Based Channels by Fatty Acids

    PubMed Central

    Puebla, Carlos; Retamal, Mauricio A.; Acuña, Rodrigo; Sáez, Juan C.

    2017-01-01

    In this mini-review, we briefly summarize the current knowledge about the effects of fatty acids (FAs) on connexin-based channels, as well as discuss the limited information about the impact FAs may have on pannexins (Panxs). FAs regulate diverse cellular functions, some of which are explained by changes in the activity of channels constituted by connexins (Cxs) or Panxs, which are known to play critical roles in maintaining the functional integrity of diverse organs and tissues. Cxs are transmembrane proteins that oligomerize into hexamers to form hemichannels (HCs), which in turn can assemble into dodecamers to form gap junction channels (GJCs). While GJCs communicate the cytoplasm of contacting cells, HCs serve as pathways for the exchange of ions and small molecules between the intra and extracellular milieu. Panxs, as well as Cx HCs, form channels at the plasma membrane that enable the interchange of molecules between the intra and extracellular spaces. Both Cx- and Panx-based channels are controlled by several post-translational modifications. However, the mechanism of action of FAs on these channels has not been described in detail. It has been shown however that FAs frequently decrease GJC-mediated cell-cell communication. The opposite effect also has been described for HC or Panx-dependent intercellular communication, where, the acute FA effect can be reversed upon washout. Additionally, changes in GJCs mediated by FAs have been associated with post-translational modifications (e.g., phosphorylation), and seem to be directly related to chemical properties of FAs (e.g., length of carbon chain and/or degree of saturation), but this possible link remains poorly understood. PMID:28174541

  6. Gas-phase acid-base properties of melamine and cyanuric acid.

    PubMed

    Mukherjee, Sumit; Ren, Jianhua

    2010-10-01

    The thermochemical properties of melamine and cyanuric acid were characterized using mass spectrometry measurements along with computational studies. A triple-quadrupole mass spectrometer was employed with the application of the extended Cooks kinetic method. The proton affinity (PA), gas-phase basicity (GB), and protonation entropy (Δ(p)S) of melamine were determined to be 226.2 ± 2.0 kcal/mol, 218.4 ± 2.0 kcal/mol, and 26.2 ± 2.0 cal/mol K, respectively. The deprotonation enthalpy (Δ(acid)H), gas-phase acidity (Δ(acid)G), and deprotonation entropy (Δ(acid)S) of cyanuric acid were determined to be 330.7 ± 2.0 kcal/mol, 322.9 ± 2.0 kcal/mol, and 26.1 ± 2.0 cal/mol K, respectively. The geometries and energetics of melamine, cyanuric acid, and related ionic species were calculated at the B3LYP/6-31+G(d) level of theory. The computationally predicted proton affinity of melamine (225.9 kcal/mol) and gas-phase deprotonation enthalpy of cyanuric acid (328.4 kcal/mol) agree well with the experimental results. Melamine is best represented as the imide-like triazine-triamine form and the triazine nitrogen is more basic than the amino group nitrogen. Cyanuric acid is best represented as the keto-like tautomer and the N-H group is the most probable proton donor.

  7. Searching for the Norm in a System of Absolutes: A Case Study of Standards-Based Accountability Reform in Pre-Kindergarten

    ERIC Educational Resources Information Center

    Brown, Christopher

    2011-01-01

    Research Findings: The emergence of standards-based accountability reforms in early childhood education has created new challenges for the field. This article presents findings from a case study that explored how stakeholders in a large urban pre-kindergarten program struggled to implement an assessment tool that aligned the normative academic…

  8. Ensuring Accountability for All Children in an Era of Standards-Based Reform: Alternate Achievement Standards. Policy Symposium Proceedings (Arlington, VA, February 4-6, 2004).

    ERIC Educational Resources Information Center

    Educational Policy Reform Research Institute, 2004

    2004-01-01

    The Educational Policy Reform Research Institute (EPRRI) and the US Department of Education's Office of Special Education Programs (OSEP) held a policy symposium entitled "Ensuring Accountability for All Children in an Era of Standards-Based Reform: Alternate Achievement Standards" February 4-6, 2004 at the Crystal City Marriott in Arlington,…

  9. Enhanced Student Learning in Accounting Utilising Web-Based Technology, Peer-Review Feedback and Reflective Practices: A Learning Community Approach to Assessment

    ERIC Educational Resources Information Center

    Taylor, Sue; Ryan, Mary; Pearce, Jon

    2015-01-01

    Higher education is becoming a major driver of economic competitiveness in an increasingly knowledge-driven global economy. Maintaining the competitive edge has seen an increase in public accountability of higher education institutions through the mechanism of ranking universities based on the quality of their teaching and learning outcomes. As a…

  10. Polyol and Amino Acid-Based Biosurfactants, Builders, and Hydrogels

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This chapter reviews different detergent materials which have been synthesized from natural agricultural commodities. Background information, which gives reasons why the use of biobased materials may be advantageous, is presented. Detergent builders from L-aspartic acid, citric acid and D-sorbitol...

  11. Wheat flour based propionic acid fermentation: an economic approach.

    PubMed

    Kagliwal, Lalit D; Survase, Shrikant A; Singhal, Rekha S; Granström, Tom

    2013-02-01

    A process for the fermentative production of propionic acid from whole wheat flour using starch and gluten as nutrients is presented. Hydrolysis of wheat flour starch using amylases was optimized. A batch fermentation of hydrolysate supplemented with various nitrogen sources using Propionibacterium acidipropionici NRRL B 3569 was performed. The maximum production of 48.61, 9.40, and 11.06 g of propionic acid, acetic acid and succinic acid, respectively, was found with wheat flour hydrolysate equivalent to 90 g/l glucose and supplemented with 15 g/l yeast extract. Further, replacement of yeast extract with wheat gluten hydrolysate showed utilization of gluten hydrolysate without compromising the yields and also improving the economics of the process. The process so developed could be useful for production of animal feed from whole wheat with in situ production of preservatives, and also suggest utilization of sprouted or germinated wheat for the production of organic acids.

  12. High Performance Fatty Acid-Based Vinyl Ester Resin for Liquid Molding

    DTIC Science & Technology

    2007-07-01

    Diglycidyl ether of bisphenol-A ( DGEBA ) Methacrylic Acid Figure 1: The reaction of DGEBA and methacrylic acid to produce the vinyl ester 2.3...High Performance Fatty Acid -Based Vinyl Ester Resin for Liquid Molding by Xing Geng, John J. La Scala, James M. Sands, and Giuseppe R...it to the originator. Army Research Laboratory Aberdeen Proving Ground, MD 21005-5069 ARL-RP-184 July 2007 High Performance Fatty Acid

  13. Efficient production of free fatty acids from ionic liquid-based acid- or enzyme-catalyzed bamboo hydrolysate.

    PubMed

    Mi, Le; Qin, Dandan; Cheng, Jie; Wang, Dan; Li, Sha; Wei, Xuetuan

    2017-03-01

    Two engineered Escherichia coli strains, DQ101 (MG1655 fadD (-))/pDQTES and DQ101 (MG1655 fadD (-))/pDQTESZ were constructed to investigate the free fatty acid production using ionic liquid-based acid- or enzyme-catalyzed bamboo hydrolysate as carbon source in this study. The plasmid, pDQTES, carrying an acyl-ACP thioesterase 'TesA of E. coli in pTrc99A was constructed firstly, and then (3R)-hydroxyacyl-ACP dehydratase was ligated after the TesA to give the plasmid pDQTESZ. These two strains exhibited efficient fatty acid production when glucose was used as the sole carbon source, with a final concentration of 2.45 and 3.32 g/L, respectively. The free fatty acid production of the two strains on xylose is not as efficient as that on glucose, which was 2.32 and 2.96 g/L, respectively. For mixed sugars, DQ101 (MG1655 fadD (-))-based strains utilized glucose and pentose sequentially under the carbon catabolite repression (CCR) regulation. The highest total FFAs concentration from the mixed sugar culture reached 2.81 g/L by DQ101 (MG1655 fadD (-))/pDQTESZ. Furthermore, when ionic liquid-based enzyme-catalyzed bamboo hydrolysate was used as the carbon source, the strain DQ101 (MG1655 fadD (-))/pDQTESZ could produce 1.23 g/L FFAs with a yield of 0.13 g/g, and while it just produced 0.65 g/L free fatty acid with the ionic liquid-based acid-catalyzed bamboo hydrolysate as the feedstock. The results suggested that enzymatic catalyzed bamboo hydrolysate with ionic liquid pretreatment could serve as an efficient feedstock for free fatty acid production.

  14. Revealing Nucleic Acid Mutations Using Förster Resonance Energy Transfer-Based Probes

    PubMed Central

    Junager, Nina P. L.; Kongsted, Jacob; Astakhova, Kira

    2016-01-01

    Nucleic acid mutations are of tremendous importance in modern clinical work, biotechnology and in fundamental studies of nucleic acids. Therefore, rapid, cost-effective and reliable detection of mutations is an object of extensive research. Today, Förster resonance energy transfer (FRET) probes are among the most often used tools for the detection of nucleic acids and in particular, for the detection of mutations. However, multiple parameters must be taken into account in order to create efficient FRET probes that are sensitive to nucleic acid mutations. In this review; we focus on the design principles for such probes and available computational methods that allow for their rational design. Applications of advanced, rationally designed FRET probes range from new insights into cellular heterogeneity to gaining new knowledge of nucleic acid structures directly in living cells. PMID:27472344

  15. Ammonia Catalyzed Formation of Sulfuric Acid in Troposphere: The Curious Case of A Base Promoting Acid Rain.

    PubMed

    Bandyopadhyay, Biman; Kumar, Pradeep; Biswas, Partha

    2017-04-03

    Electronic structure calculations have been performed to investigate the role of ammonia in catalyzing the formation of sulfuric acid through hydrolysis of SO3 in Earth's atmosphere. The uncatalyzed process involves a high activation barrier and, till date, is mainly known to occur in Earth's atmosphere only when catalyzed by water and acids. Here we show that hydrolysis of SO3 can be very efficiently catalyzed by ammonia, the most abundant basic component in Earth's atmosphere. It was found, based on magnitude of relative potential energies as well as rate coefficients, that ammonia is the best among all the catalysts studied until now (water and acids) and could be a considerable factor in formation of sulfuric acid in troposphere. The calculated rate coefficient (at 298 K) of ammonia catalyzed reaction has been found to be ~10^5 - 10^7 times greater than that for water catalyzed ones. It was found, based on relative rates of ammonia and water catalyzed processes that in troposphere ammonia, together with water, could be the key factor in determining the rate of formation of sulfuric acid. In fact ammonia could surpass water in catalyzing formation of sulfuric acid via hydrolysis of SO3 at various altitudes in troposphere depending upon their relative concentrations.

  16. Visual, base-specific detection of nucleic acid hybridization using polymerization-based amplification.

    PubMed

    Hansen, Ryan R; Johnson, Leah M; Bowman, Christopher N

    2009-03-15

    Polymerization-based signal amplification offers sensitive visualization of biotinylated biomolecules functionalized to glass microarrays in a manner suitable for point-of-care use. Here we report using this method for visual detection of multiplexed nucleic acid hybridizations from complex media and develop an application toward point mutation detection and single nucleotide polymorphism (SNP) typing. Primer extension reactions were employed to label selectively and universally all complementary surface DNA hybrids with photoinitiators, permitting simultaneous and dynamic photopolymerization from positive sites to 0.5-nM target concentrations. Dramatic improvements in signal ratios between complementary and mismatched hybrids enabled visual discrimination of single base differences in KRAS codon-12 biomarkers.

  17. Production of Jatropha biodiesel fuel over sulfonic acid-based solid acids.

    PubMed

    Chen, Shih-Yuan; Lao-Ubol, Supranee; Mochizuki, Takehisa; Abe, Yohko; Toba, Makoto; Yoshimura, Yuji

    2014-04-01

    Sulfonic acid-functionalized platelet SBA-15 mesoporous silica with an acid capacity of 2.44mmol H(+) g-cat(-1) (shortly termed 15SA-SBA-15-p) was one-pot synthesized by co-condensation method. When applied as solid acid catalyst in synthesis of Jatropha biodiesel fuel (BDF), the 15SA-SBA-15-p catalyst showed higher activity and resistances to water and free fatty acid (FFA) than commercial sulfonic resins of Amberlyst-15 and SAC-13. For the continuous Jatropha BDF production, a steady 75-78wt% of fatty acid methyl ester (FAME) content was obtained over 15SA-SBA-15-p catalyst at 150°C for 75h, whereas the Amberlyst-15 and SAC-13 catalysts were quickly deactivated due to the decomposition of thermally unstable framework and serious leaching of sulfonic acids. More importantly, the quality, stability and cold flow characteristic of Jatropha BDF synthesized by 15SA-SBA-15-p catalyst were better than those synthesized by Amberlyst-15 and SAC-13 catalysts, making the blending with petro-diesel an easy task.

  18. Development of polylactic acid-based materials through reactive modification

    NASA Astrophysics Data System (ADS)

    Fowlks, Alison Camille

    2009-12-01

    Polylactic acid (PLA)-based systems have shown to be of great potential for the development of materials requiring biobased content, biodegradation, and sufficient properties. The efforts in this study are directed toward addressing the current research need to overcome some of the inherent drawbacks of PLA. To meet this need, reactive extrusion was employed to develop new materials based on PLA by grafting, compounding, and polymer blending. In the first part of this work, maleic anhydride (MA) was grafted onto PLA by reactive extrusion. Two structurally different peroxides were used to initiate grafting and results were reported on the basis of grafting, molecular weight, and thermal behavior. An inverse relationship between degree of grafting and molecular weight was established. It was also found that, regardless of peroxide type, there is an optimum peroxid-to-MA ratio of 0.5:2 that promotes maximum grafting, beyond which degradation reactions become predominant. Overall, it was found that the maleated copolymer (MAPLA) could be used as an interfacial modifier in PLA-based composites. Therefore, MAPLA was incorporated into PLA-talc composites in varying concentrations. The influence of the MAPLA addition on the mechanical and thermal behavior was investigated. When added in an optimum concentration, MAPLA improved the tensile strength and crystallization of the composite. Furthermore, microscopic observation confirmed the compatibilization effect of MAPLA in PLA-talc composites. Vinyltrimethoxysilane was free-radically grafted onto the backbone of PLA and subsequently moisture crosslinked. The effects of monomer, initiator, and catalyst concentration on the degree of crosslinking and the mechanical and thermal properties were investigated. The presence of a small amount of catalyst showed to be a major contributor to the crosslinking formation in the time frame investigated, shown by an increase in gel content and decrease in crystallinity. Furthermore

  19. [Optimization of ecological footprint model based on environmental pollution accounts: a case study in Pearl River Delta urban agglomeration].

    PubMed

    Bai, Yu; Zeng, Hui; Wei, Jian-bing; Zhang, Wen-juan; Zhao, Hong-wei

    2008-08-01

    To solve the problem of ignoring the calculation of environment pollution in traditional ecological footprint model accounts, this paper put forward an optimized ecological footprint (EF) model, taking the pollution footprint into account. In the meantime, the environmental capacity's calculation was also added into the system of ecological capacity, and further used to do ecological assessment of Pearl River Delta urban agglomeration in 2005. The results showed a perfect inosculation between the ecological footprint and the development characteristics and spatial pattern, and illustrated that the optimized EF model could make a better orientation for the environmental pollution in the system, and also, could roundly explain the environmental effects of human activity. The optimization of ecological footprint model had better integrality and objectivity than traditional models.

  20. Description and User Manual for a Web-Based Interface to a Transit-Loss Accounting Program for Monument and Fountain Creeks, El Paso and Pueblo Counties, Colorado

    USGS Publications Warehouse

    Kuhn, Gerhard; Krammes, Gary S.; Beal, Vivian J.

    2007-01-01

    The U.S. Geological Survey, in cooperation with Colorado Springs Utilities, the Colorado Water Conservation Board, and the El Paso County Water Authority, began a study in 2004 with the following objectives: (1) Apply a stream-aquifer model to Monument Creek, (2) use the results of the modeling to develop a transit-loss accounting program for Monument Creek, (3) revise an existing accounting program for Fountain Creek to easily incorporate ongoing and future changes in management of return flows of reusable water, and (4) integrate the two accounting programs into a single program and develop a Web-based interface to the integrated program that incorporates simple and reliable data entry that is automated to the fullest extent possible. This report describes the results of completing objectives (2), (3), and (4) of that study. The accounting program for Monument Creek was developed first by (1) using the existing accounting program for Fountain Creek as a prototype, (2) incorporating the transit-loss results from a stream-aquifer modeling analysis of Monument Creek, and (3) developing new output reports. The capabilities of the existing accounting program for Fountain Creek then were incorporated into the program for Monument Creek and the output reports were expanded to include Fountain Creek. A Web-based interface to the new transit-loss accounting program then was developed that provided automated data entry. An integrated system of 34 nodes and 33 subreaches was integrated by combining the independent node and subreach systems used in the previously completed stream-aquifer modeling studies for the Monument and Fountain Creek reaches. Important operational criteria that were implemented in the new transit-loss accounting program for Monument and Fountain Creeks included the following: (1) Retain all the reusable water-management capabilities incorporated into the existing accounting program for Fountain Creek; (2) enable daily accounting and transit

  1. Viewpoints on Accountability.

    ERIC Educational Resources Information Center

    Educational Innovators Press, Tucson, AZ.

    This booklet contains five papers which examine the activities, successes, and pitfalls encountered by educators who are introducing accountability techniques into instructional programs where they did not exist in the past. The papers are based on actual programs and offer possible solutions in the areas considered, which are 1) performance…

  2. Making Accountability Really Count

    ERIC Educational Resources Information Center

    Resnick, Lauren B.

    2006-01-01

    Standards-based education has now reached a stage where it is possible to evaluate its overall effectiveness. Several earlier papers in the special issue of "Educational Measurement: Issues and Practice" on "Test Scores and State Accountability" (Volume 24, Number 4) examined specific state policies and their effects on schools…

  3. Hybride magnetic nanostructure based on amino acids functionalized polypyrrole

    NASA Astrophysics Data System (ADS)

    Nan, Alexandrina; Bunge, Alexander; Turcu, Rodica

    2015-12-01

    Conducting polypyrrole is especially promising for many commercial applications because of its unique optical, electric, thermal and mechanical properties. We report the synthesis and characterization of novel pyrrole functionalized monomers and core-shell hybrid nanostructures, consisting of a conjugated polymer layer (amino acids functionalized pyrrole copolymers) and a magnetic nanoparticle core. For functionalization of the pyrrole monomer we used several amino acids: tryptophan, leucine, phenylalanine, serine and tyrosine. These amino acids were linked via different types of hydrophobic linkers to the nitrogen atom of the pyrrole monomer. The magnetic core-shell hybrid nanostructures are characterized by various methods such as FTIR spectroscopy, transmission electron microscopy (TEM) and magnetic measurements.

  4. Hybride magnetic nanostructure based on amino acids functionalized polypyrrole

    SciTech Connect

    Nan, Alexandrina Bunge, Alexander; Turcu, Rodica

    2015-12-23

    Conducting polypyrrole is especially promising for many commercial applications because of its unique optical, electric, thermal and mechanical properties. We report the synthesis and characterization of novel pyrrole functionalized monomers and core-shell hybrid nanostructures, consisting of a conjugated polymer layer (amino acids functionalized pyrrole copolymers) and a magnetic nanoparticle core. For functionalization of the pyrrole monomer we used several amino acids: tryptophan, leucine, phenylalanine, serine and tyrosine. These amino acids were linked via different types of hydrophobic linkers to the nitrogen atom of the pyrrole monomer. The magnetic core-shell hybrid nanostructures are characterized by various methods such as FTIR spectroscopy, transmission electron microscopy (TEM) and magnetic measurements.

  5. Proton exchange in acid-base complexes induced by reaction coordinates with heavy atom motions

    NASA Astrophysics Data System (ADS)

    Alavi, Saman; Taghikhani, Mahdi

    2012-06-01

    We extend previous work on nitric acid-ammonia and nitric acid-alkylamine complexes to illustrate that proton exchange reaction coordinates involve the rocking motion of the base moiety in many double hydrogen-bonded gas phase strong acid-strong base complexes. The complexes studied involve the biologically and atmospherically relevant glycine, formic, acetic, propionic, and sulfuric acids with ammonia/alkylamine bases. In these complexes, the magnitude of the imaginary frequencies associated with the proton exchange transition states are <400 cm-1. This contrasts with widely studied proton exchange reactions between symmetric carboxylic acid dimers or asymmetric DNA base pair and their analogs where the reaction coordinate is localized in proton motions and the magnitude of the imaginary frequencies for the transition states are >1100 cm-1. Calculations on complexes of these acids with water are performed for comparison. Variations of normal vibration modes along the reaction coordinate in the complexes are described.

  6. In Vitro Investigation of Self-Assembled Nanoparticles Based on Hyaluronic Acid-Deoxycholic Acid Conjugates for Controlled Release Doxorubicin: Effect of Degree of Substitution of Deoxycholic Acid

    PubMed Central

    Wei, Wen-Hao; Dong, Xue-Meng; Liu, Chen-Guang

    2015-01-01

    Self-assembled nanoparticles based on a hyaluronic acid-deoxycholic acid (HD) chemical conjugate with different degree of substitution (DS) of deoxycholic acid (DOCA) were prepared. The degree of substitution (DS) was determined by titration method. The nanoparticles were loaded with doxorubicin (DOX) as the model drug. The human cervical cancer (HeLa) cell line was utilized for in vitro studies and cell cytotoxicity of DOX incorporated in the HD nanoparticles was accessed by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. In addition, cellular uptake of fluorescently labeled nanoparticles was also investigated. An increase in the degree of deoxycholic acid substitution reduced the size of the nanoparticles and also enhanced their drug encapsulation efficiency (EE), which increased with the increase of DS. A higher degree of deoxycholic acid substitution also lead to a lower release rate and an initial burst release of doxorubicin from the nanoparticles. In summary, the degree of substitution allows the modulation of the particle size, drug encapsulation efficiency, drug release rate, and cell uptake efficiency of the nanoparticles. The herein developed hyaluronic acid-deoxycholic acid conjugates are a good candidate for drug delivery and could potentiate therapeutic formulations for doxorubicin–mediated cancer therapy. PMID:25837468

  7. In vitro investigation of self-assembled nanoparticles based on hyaluronic acid-deoxycholic acid conjugates for controlled release doxorubicin: effect of degree of substitution of deoxycholic acid.

    PubMed

    Wei, Wen-Hao; Dong, Xue-Meng; Liu, Chen-Guang

    2015-03-31

    Self-assembled nanoparticles based on a hyaluronic acid-deoxycholic acid (HD) chemical conjugate with different degree of substitution (DS) of deoxycholic acid (DOCA) were prepared. The degree of substitution (DS) was determined by titration method. The nanoparticles were loaded with doxorubicin (DOX) as the model drug. The human cervical cancer (HeLa) cell line was utilized for in vitro studies and cell cytotoxicity of DOX incorporated in the HD nanoparticles was accessed by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. In addition, cellular uptake of fluorescently labeled nanoparticles was also investigated. An increase in the degree of deoxycholic acid substitution reduced the size of the nanoparticles and also enhanced their drug encapsulation efficiency (EE), which increased with the increase of DS. A higher degree of deoxycholic acid substitution also lead to a lower release rate and an initial burst release of doxorubicin from the nanoparticles. In summary, the degree of substitution allows the modulation of the particle size, drug encapsulation efficiency, drug release rate, and cell uptake efficiency of the nanoparticles. The herein developed hyaluronic acid-deoxycholic acid conjugates are a good candidate for drug delivery and could potentiate therapeutic formulations for doxorubicin-mediated cancer therapy.

  8. Target-responsive structural switching for nucleic acid-based sensors.

    PubMed

    Li, Di; Song, Shiping; Fan, Chunhai

    2010-05-18

    Interest in the development of sensitive, selective, rapid, and cost-effective biosensors for biomedical analysis, environmental monitoring, and the detection of bioterrorism agents is rapidly increasing. A classic biosensor directly transduces ligand-target binding events into a measurable physical readout. More recently, researchers have proposed novel biosensing strategies that couple ligand-induced structural switching of biomolecules with advanced optical and electronic transducers. This approach has proven to be a highly general platform for the development of new biosensors. In this Account, we describe a series of electrochemical and optical nucleic acid sensors that use target-responsive DNA structures. By employing surface-confined DNA structures with appropriate redox labels, we can monitor target-induced structural switching of DNA or aptamer-specific small molecule probes by measuring electrochemical currents that are directly associated with the distance between the redox label and the electrode surface. We have also demonstrated significant improvements in sensing performance through optimization of the DNA self-assembly process at electrode surfaces or the introduction of nanomaterial-based signal amplification. Alternatively, gold nanoparticles interact differently with folded and unfolded DNA structures, which provides a visual method for detecting target-induced structural switching based on the plasmonic change of gold nanoparticles. This novel method using gold nanoparticles has proven particularly suitable for the detection of a range of small-molecule targets (e.g., cocaine) and environmentally toxic metal ions (e.g., Hg(2+)). Rational sequence design of DNA aptamers improves the sensitivity and increases the reaction kinetics. Recently, we have also designed microfluidic devices that allow rapid and portable mercury detection with the naked eye. This Account focuses on the use of bulk and nanoscale gold and DNA/aptamer molecules. We expect

  9. Intracellular Proton-mediated Activation of TRPV3 Channels Accounts for the Exfoliation Effect of α-Hydroxyl Acids on Keratinocytes*

    PubMed Central

    Cao, Xu; Yang, Fan; Zheng, Jie; Wang, KeWei

    2012-01-01

    α-Hydroxyl acids (AHAs) from natural sources act as proton donors and topical compounds that penetrate skin and are well known in the cosmetic industry for their use in chemical peels and improvement of the skin. However, little is known about how AHAs cause exfoliation to expose fresh skin cells. Here we report that the transient receptor potential vanilloid 3 (TRPV3) channel in keratinocytes is potently activated by intracellular acidification induced by glycolic acid. Patch clamp recordings and cell death assay of both human keratinocyte HaCaT cells and TRPV3-expressing HEK-293 cells confirmed that intracellular acidification led to direct activation of TRPV3 and promoted cell death. Site-directed mutagenesis revealed that an N-terminal histidine residue, His-426, known to be involved in 2-aminoethyl diphenylborinate-mediated TRPV3 activation, is critical for sensing intracellular proton levels. Taken together, our findings suggest that intracellular protons can strongly activate TRPV3, and TRPV3-mediated proton sensing and cell death in keratinocytes may serve as a molecular basis for the cosmetic use of AHAs and their therapeutic potential in acidic pH-related skin disorders. PMID:22679014

  10. Docosahexaenoic acid and shore-based diets in hominin encephalization: a rebuttal.

    PubMed

    Cunnane, Stephen C; Plourde, Mélanie; Stewart, Kathy; Crawford, Michael A

    2007-01-01

    Carlson and Kingston ([2007]: Am J Hum Biol 19:132-141) propose that preformed dietary docosahexaenoic acid (an omega-3 fatty acid in fish) did not have a significant role in hominin encephalization. Their position hinges on claiming that humans are able to make sufficient docosahexaenoic acid from the plant-based "parent" omega-3 fatty acid-alpha-linolenic acid. They also suggest that hominin fish consumption occurred too late to have materially influenced encephalization. The authors quantify here a summary of the published data showing that humans cannot make sufficient docosahexaenoic acid to maintain normal infant brain development. The authors also provide evidence that the fossil record shows that some of the earliest hominins were regularly consuming fish. Hence, we reject Carlson and Kingston's position and reiterate support for the concept that access to shore-based diets containing docosahexaenoic acid was necessary for hominin encephalization beyond the level seen in the great apes.

  11. Students' Understanding of Acid, Base and Salt Reactions in Qualitative Analysis.

    ERIC Educational Resources Information Center

    Tan, Kim-Chwee Daniel; Goh, Ngoh-Khang; Chia, Lian-Sai; Treagust, David F.

    2003-01-01

    Uses a two-tier, multiple-choice diagnostic instrument to determine (n=915) grade 10 students' understanding of the acid, base, and salt reactions involved in basic qualitative analysis. Reports that many students did not understand the formation of precipitates and the complex salts, acid/salt-base reactions, and thermal decomposition involved in…

  12. Collaborative Strategies for Teaching Common Acid-Base Disorders to Medical Students

    ERIC Educational Resources Information Center

    Petersen, Marie Warrer; Toksvang, Linea Natalie; Plovsing, Ronni R.; Berg, Ronan M. G.

    2014-01-01

    The ability to recognize and diagnose acid-base disorders is of the utmost importance in the clinical setting. However, it has been the experience of the authors that medical students often have difficulties learning the basic principles of acid-base physiology in the respiratory physiology curriculum, particularly when applying this knowledge to…

  13. The acid-base resistant zone in three dentin bonding systems.

    PubMed

    Inoue, Go; Nikaido, Toru; Foxton, Richard M; Tagami, Junji

    2009-11-01

    An acid-base resistant zone has been found to exist after acid-base challenge adjacent to the hybrid layer using SEM. The aim of this study was to examine the acid-base resistant zone using three different bonding systems. Dentin disks were applied with three different bonding systems, and then a resin composite was light-cured to make dentin disk sandwiches. After acid-base challenge, the polished surfaces were observed using SEM. For both one- and two-step self-etching primer systems, an acid-base resistant zone was clearly observed adjacent to the hybrid layer - but with differing appearances. For the wet bonding system, the presence of an acid-base resistant zone was unclear. This was because the self-etching primer systems etched the dentin surface mildly, such that the remaining mineral phase of dentin and the bonding agent yielded clear acid-base resistant zones. In conclusion, the acid-base resistant zone was clearly observed when self-etching primer systems were used, but not so for the wet bonding system.

  14. Mixed acid-base disorder secondary to topiramate use in traumatic brain injury

    PubMed Central

    Golla, S.; Anandh, U.; Balasubramaniam, A.

    2016-01-01

    We report a case of a man with traumatic brain injury. He was started on to prophylactic topiramate which led to a mixed acid-base disorder. He had severe metabolic acidosis secondary to renal tubular acidification defect and respiratory alkalosis secondary to hyperventilation. Withdrawal of the offending drug led to the prompt resolution of the acid-base disturbance. PMID:27942179

  15. Red Shoe-Blue Shoe: An Acid-Base Demonstration with a Fashionable Twist.

    ERIC Educational Resources Information Center

    Breyer, Arthur C.; Uzelmeier, Calvin E.

    1998-01-01

    Illustrates that acid-base indicators come in many forms and the reversible effects that acids and bases have on the colors of such indicators. An object is dyed in an indicator, which causes the object to turn dark blue at pH less than 3.0 to 5.0. Suggests using dyeable fabric shoes and other cotton articles. (PVD)

  16. Lewis Acid-Base, Molecular Modeling, and Isotopic Labeling in a Sophomore Inorganic Chemistry Laboratory

    ERIC Educational Resources Information Center

    Nataro, Chip; Ferguson, Michelle A.; Bocage, Katherine M.; Hess, Brian J.; Ross, Vincent J.; Swarr, Daniel T.

    2004-01-01

    An experiment to prepare a deuterium labeled adduct of a Lewis acid and Lewis base, to use computational methods allowing students to visualize the LUMO of Lewis acids, the HOMO of Lewis bases and the molecular orbitals of the adduct that is formed is developed. This allows students to see the interplay between calculated and experimental results.

  17. Thai Grade 11 Students' Alternative Conceptions for Acid-Base Chemistry

    ERIC Educational Resources Information Center

    Artdej, Romklao; Ratanaroutai, Thasaneeya; Coll, Richard Kevin; Thongpanchang, Tienthong

    2010-01-01

    This study involved the development of a two-tier diagnostic instrument to assess Thai high school students' understanding of acid-base chemistry. The acid-base diagnostic test (ABDT) comprising 18 items was administered to 55 Grade 11 students in a science and mathematics programme during the second semester of the 2008 academic year. Analysis of…

  18. Using Conceptual Change Texts with Analogies for Misconceptions in Acids and Bases

    ERIC Educational Resources Information Center

    Cetingul, Ipek; Geban, Omer

    2011-01-01

    This study was conducted to explore the effectiveness of conceptual change oriented instruction over traditional instruction on students' understanding of acids and bases concept. Besides, effects of gender difference and science process skills on students' understanding of acids and bases were also investigated. Analysis of the results showed…

  19. Using the Logarithmic Concentration Diagram, Log "C", to Teach Acid-Base Equilibrium

    ERIC Educational Resources Information Center

    Kovac, Jeffrey

    2012-01-01

    Acid-base equilibrium is one of the most important and most challenging topics in a typical general chemistry course. This article introduces an alternative to the algebraic approach generally used in textbooks, the graphical log "C" method. Log "C" diagrams provide conceptual insight into the behavior of aqueous acid-base systems and allow…

  20. High School Students' Understanding of Acid-Base Concepts: An Ongoing Challenge for Teachers

    ERIC Educational Resources Information Center

    Damanhuri, Muhd Ibrahim Muhamad; Treagust, David F.; Won, Mihye; Chandrasegaran, A. L.

    2016-01-01

    Using a quantitative case study design, the "Acids-Bases Chemistry Achievement Test" ("ABCAT") was developed to evaluate the extent to which students in Malaysian secondary schools achieved the intended curriculum on acid-base concepts. Responses were obtained from 260 Form 5 (Grade 11) students from five schools to initially…

  1. A Comparative Study of French and Turkish Students' Ideas on Acid-Base Reactions

    ERIC Educational Resources Information Center

    Cokelez, Aytekin

    2010-01-01

    The goal of this comparative study was to determine the knowledge that French and Turkish upper secondary-school students (grades 11 and 12) acquire on the concept of acid-base reactions. Following an examination of the relevant curricula and textbooks in the two countries, 528 students answered six written questions about the acid-base concept.…

  2. Canonical Pedagogical Content Knowledge by Cores for Teaching Acid-Base Chemistry at High School

    ERIC Educational Resources Information Center

    Alvarado, Clara; Cañada, Florentina; Garritz, Andoni; Mellado, Vicente

    2015-01-01

    The topic of acid-base chemistry is one of the oldest in general chemistry courses and it has been almost continuously in academic discussion. The central purpose of documenting the knowledge and beliefs of a group of ten Mexican teachers with experience in teaching acid-base chemistry in high school was to know how they design, prepare and…

  3. Measuring the Confidence of 8th Grade Taiwanese Students' Knowledge of Acids and Bases

    ERIC Educational Resources Information Center

    Jack, Brady Michael; Liu, Chia-Ju; Chiu, Houn-Lin; Tsai, Chun-Yen

    2012-01-01

    The present study investigated whether gender differences were present on the confidence judgments made by 8th grade Taiwanese students on the accuracy of their responses to acid-base test items. A total of 147 (76 male, 71 female) students provided item-specific confidence judgments during a test of their knowledge of acids and bases. Using the…

  4. Effects of fatty acid activation on photosynthetic production of fatty acid-based biofuels in Synechocystis sp. PCC6803

    PubMed Central

    2012-01-01

    Background Direct conversion of solar energy and carbon dioxide to drop in fuel molecules in a single biological system can be achieved from fatty acid-based biofuels such as fatty alcohols and alkanes. These molecules have similar properties to fossil fuels but can be produced by photosynthetic cyanobacteria. Results Synechocystis sp. PCC6803 mutant strains containing either overexpression or deletion of the slr1609 gene, which encodes an acyl-ACP synthetase (AAS), have been constructed. The complete segregation and deletion in all mutant strains was confirmed by PCR analysis. Blocking fatty acid activation by deleting slr1609 gene in wild-type Synechocystis sp. PCC6803 led to a doubling of the amount of free fatty acids and a decrease of alkane production by up to 90 percent. Overexpression of slr1609 gene in the wild-type Synechocystis sp. PCC6803 had no effect on the production of either free fatty acids or alkanes. Overexpression or deletion of slr1609 gene in the Synechocystis sp. PCC6803 mutant strain with the capability of making fatty alcohols by genetically introducing fatty acyl-CoA reductase respectively enhanced or reduced fatty alcohol production by 60 percent. Conclusions Fatty acid activation functionalized by the slr1609 gene is metabolically crucial for biosynthesis of fatty acid derivatives in Synechocystis sp. PCC6803. It is necessary but not sufficient for efficient production of alkanes. Fatty alcohol production can be significantly improved by the overexpression of slr1609 gene. PMID:22433663

  5. Hyaluronic acid-based hydrogel enhances neuronal survival in spinal cord slice cultures from postnatal mice.

    PubMed

    Schizas, Nikos; Rojas, Ramiro; Kootala, Sujit; Andersson, Brittmarie; Pettersson, Jennie; Hilborn, Jons; Hailer, Nils P

    2014-02-01

    Numerous biomaterials based on extracellular matrix-components have been developed. It was our aim to investigate whether a hyaluronic acid-based hydrogel improves neuronal survival and tissue preservation in organotypic spinal cord slice cultures. Organotypic spinal cord slice cultures were cultured for 4 days in vitro (div), either on hyaluronic acid-based hydrogel (hyaluronic acid-gel group), collagen gel (collagen group), directly on polyethylene terephthalate membrane inserts (control group), or in the presence of soluble hyaluronic acid (soluble hyaluronic acid group). Cultures were immunohistochemically stained against neuronal antigen NeuN and analyzed by confocal laser scanning microscopy. Histochemistry for choline acetyltransferance, glial fibrillary acidic protein, and Griffonia simplicifolia isolectin B4 followed by quantitative analysis was performed to assess motorneurons and different glial populations. Confocal microscopic analysis showed a 4-fold increase in the number of NeuN-positive neurons in the hyaluronic acid-gel group compared to both collagen (p < 0.001) and control groups (p < 0.001). Compared to controls, organotypic spinal cord slice cultures maintained on hyaluronic acid-based hydrogel showed 5.9-fold increased survival of choline acetyltransferance-positive motorneurons (p = 0.008), 2-fold more numerous resting microglial cells in the white matter (p = 0.031), and a 61.4% reduction in the number of activated microglial cells within the grey matter (p = 0.05). Hyaluronic acid-based hydrogel had a shear modulus (G') of ≈1200 Pascals (Pa), which was considerably higher than the ≈25 Pa measured for collagen gel. Soluble hyaluronic acid failed to improve tissue preservation. In conclusion, hyaluronic acid-based hydrogel improves neuronal and - most notably - motorneuron survival in organotypic spinal cord slice cultures and microglial activation is limited. The positive effects of hyaluronic acid-based hydrogel

  6. Synthesis and characterization of acetic acid and ethanoic acid (based)-maleimide

    NASA Astrophysics Data System (ADS)

    Poad, Siti Nashwa Mohd; Hassan, Nurul Izzaty; Hassan, Nur Hasyareeda

    2016-11-01

    A new route to the synthesis of maleimide is described. 2-(2,5-dioxo-2,5-dihydro-1H-pyrrol-1-yl)acetic acid maleimide (1) and 2-(4-(2,5-Dioxo-2,5-dihydro- 1H-pyrrol-1-yl)phenyl)ethanoic acid maleimide (2) have been synthesized by the reaction of maleic anhydride with glycine and 4-aminophenyl acetic aicd. Maleimide (1) was synthesized by conventional technique while maleimide (2) was synthesized by microwave method. The compounds were characterized using FT-Infrared (FT-IR), 1H and 13C Nuclear Magnetic Resonance (NMR) spectroscopies and Mass Spectrometry.

  7. Fatty acid synthesis in Escherichia coli and its applications towards the production of fatty acid based biofuels

    PubMed Central

    2014-01-01

    The idea of renewable and regenerative resources has inspired research for more than a hundred years. Ideally, the only spent energy will replenish itself, like plant material, sunlight, thermal energy or wind. Biodiesel or ethanol are examples, since their production relies mainly on plant material. However, it has become apparent that crop derived biofuels will not be sufficient to satisfy future energy demands. Thus, especially in the last decade a lot of research has focused on the production of next generation biofuels. A major subject of these investigations has been the microbial fatty acid biosynthesis with the aim to produce fatty acids or derivatives for substitution of diesel. As an industrially important organism and with the best studied microbial fatty acid biosynthesis, Escherichia coli has been chosen as producer in many of these studies and several reviews have been published in the fields of E. coli fatty acid biosynthesis or biofuels. However, most reviews discuss only one of these topics in detail, despite the fact, that a profound understanding of the involved enzymes and their regulation is necessary for efficient genetic engineering of the entire pathway. The first part of this review aims at summarizing the knowledge about fatty acid biosynthesis of E. coli and its regulation, and it provides the connection towards the production of fatty acids and related biofuels. The second part gives an overview about the achievements by genetic engineering of the fatty acid biosynthesis towards the production of next generation biofuels. Finally, the actual importance and potential of fatty acid-based biofuels will be discussed. PMID:24405789

  8. [Reaction of bone tissue elements on synthetic bioresorbable materials based on lactic and glycolic acids].

    PubMed

    Kulakov, A A; Grigor'ian, A S

    2014-01-01

    The aim of the study was to evaluate the adverse effects of synthetic polymeric bioresorbable materials based on lactic and glycolic acids on the bone tissue. The study was carried-out on 40 Wister-line rats. Four types of bioresorbable polymeric materials were implanted: PolyLactide Glycolide Acid (PLGA), Poly-L-Lactide Acid (PLLA); Poly-96L/4D-Lactide Acid (96/4 PLDLA); Poly-70L/30D-Lactide Acid (70/30 PLDLA). The results showed connective tissue formation (fibrointegration) bordering bone adjacent to implanted materials. This proved the materials to cause pathogenic influence on the bone which mechanisms are described in the article.

  9. Making fate and exposure models for freshwater ecotoxicity in life cycle assessment suitable for organic acids and bases.

    PubMed

    van Zelm, Rosalie; Stam, Gea; Huijbregts, Mark A J; van de Meent, Dik

    2013-01-01

    Freshwater fate and exposure factors were determined for organic acids and bases, making use of the knowledge on electrical interaction of ionizing chemicals and their sorption to particles. The fate factor represents the residence time in the environment whereas exposure factors equal the dissolved fraction of a chemical. Multimedia fate, exposure, and effect model USES-LCA was updated to take into account the influence of ionization, based upon the acid dissociation constant (pK(a)) of a chemical, and the environmental pH. Freshwater fate (FF) and exposure (XF) factors were determined for 415 acids and 496 bases emitted to freshwater, air, and soil. The relevance of taking account of the degree of ionization of chemicals was tested by determining the ratio (R) of the new vs. fate and exposure factors determined with USES-LCA suitable for neutral chemicals only. Our results show that the majority of freshwater fate and exposure factors of chemicals that are largely ionized in the environment are larger with the ionics model compared to the factors determined with the neutrals model version. R(FF) ranged from 2.4×10(-1) to 1.6×10(1) for freshwater emissions, from 1.2×10(-2) to 2.0×10(4) for soil emissions and from 5.8×10(-2) to 6.0×10(3) for air emissions, and R(XF) from 5.3×10(-1) to 2.2×10(1). Prediction of changed solid-water partitioning, implying a change in runoff and in removal via sedimentation, and prediction of negligible air-water partition coefficient, leading to negligible volatilization were the main contributors to the changes in freshwater fate factors.

  10. Cross-linked, biodegradable, cytocompatible salicylic acid based polyesters for localized, sustained delivery of salicylic acid: an in vitro study.

    PubMed

    Chandorkar, Yashoda; Bhagat, Rajesh K; Madras, Giridhar; Basu, Bikramjit

    2014-03-10

    In order to suppress chronic inflammation while supporting cell proliferation, there has been a continuous surge toward development of polymers with the intention of delivering anti-inflammatory molecules in a sustained manner. In the above backdrop, we report the synthesis of a novel, stable, cross-linked polyester with salicylic acid (SA) incorporated in the polymeric backbone and propose a simple synthesis route by melt condensation. The as-synthesized polymer was hydrophobic with a glass transition temperature of 1 °C, which increases to 17 °C upon curing. The combination of NMR and FT-IR spectral techniques established the ester linkages in the as-synthesized SA-based polyester. The pH-dependent degradation rate and the rate of release of salicylic acid from the as-synthesized SA-based polymer were studied at physiological conditions in vitro. The polyester underwent surface erosion and exhibited linear degradation kinetics in which a change in degradation rate is observed after 4-10 days and 24% mass loss was recorded after 4 months at 37 °C and pH 7.4. The delivery of salicylic acid also showed a similar change in slopes, with a sustained release rate of 3.5% in 4 months. The cytocompatibility studies of these polyesters were carried out with C2C12 murine myoblast cells using techniques like MTT assay and flow cytometry. Our results strongly suggest that SA-based polyester supports cell proliferation for 3 days in culture and do not cause cell death (<7%), as quantified by propidium iodide (PI) stained cells. Hence, these polyesters can be used as implant materials for localized, sustained delivery of salicylic acid and have applications in adjuvant cancer therapy, chronic wound healing, and as an alternative to commercially available polymers like poly(lactic acid) and poly(glycolic acid) or their copolymers.

  11. Beyond ketonization: selective conversion of carboxylic acids to olefins over balanced Lewis acid-base pairs.

    PubMed

    Baylon, Rebecca A L; Sun, Junming; Martin, Kevin J; Venkitasubramanian, Padmesh; Wang, Yong

    2016-04-11

    We report the direct conversion of mixed carboxylic acids to C-C olefins with up to 60 mol% carbon yield through cascade (cross) ketonization, (cross) aldolization and self-deoxygenation reactions. Co-feeding hydrogen provides an additional ketone hydrogenation/dehydration pathway to a wider range of olefins.

  12. A novel enzyme-based acidizing system: Matrix acidizing and drilling fluid damage removal

    SciTech Connect

    Harris, R.E.; McKay, D.M.; Moses, V.

    1995-12-31

    A novel acidizing process is used to increase the permeability of carbonate rock cores in the laboratory and to remove drilling fluid damage from cores and wafers. Field results show the benefits of the technology as applied both to injector and producer wells.

  13. The effect of acid-base clustering and ions on the growth of atmospheric nano-particles.

    PubMed

    Lehtipalo, Katrianne; Rondo, Linda; Kontkanen, Jenni; Schobesberger, Siegfried; Jokinen, Tuija; Sarnela, Nina; Kürten, Andreas; Ehrhart, Sebastian; Franchin, Alessandro; Nieminen, Tuomo; Riccobono, Francesco; Sipilä, Mikko; Yli-Juuti, Taina; Duplissy, Jonathan; Adamov, Alexey; Ahlm, Lars; Almeida, João; Amorim, Antonio; Bianchi, Federico; Breitenlechner, Martin; Dommen, Josef; Downard, Andrew J; Dunne, Eimear M; Flagan, Richard C; Guida, Roberto; Hakala, Jani; Hansel, Armin; Jud, Werner; Kangasluoma, Juha; Kerminen, Veli-Matti; Keskinen, Helmi; Kim, Jaeseok; Kirkby, Jasper; Kupc, Agnieszka; Kupiainen-Määttä, Oona; Laaksonen, Ari; Lawler, Michael J; Leiminger, Markus; Mathot, Serge; Olenius, Tinja; Ortega, Ismael K; Onnela, Antti; Petäjä, Tuukka; Praplan, Arnaud; Rissanen, Matti P; Ruuskanen, Taina; Santos, Filipe D; Schallhart, Simon; Schnitzhofer, Ralf; Simon, Mario; Smith, James N; Tröstl, Jasmin; Tsagkogeorgas, Georgios; Tomé, António; Vaattovaara, Petri; Vehkamäki, Hanna; Vrtala, Aron E; Wagner, Paul E; Williamson, Christina; Wimmer, Daniela; Winkler, Paul M; Virtanen, Annele; Donahue, Neil M; Carslaw, Kenneth S; Baltensperger, Urs; Riipinen, Ilona; Curtius, Joachim; Worsnop, Douglas R; Kulmala, Markku

    2016-05-20

    The growth of freshly formed aerosol particles can be the bottleneck in their survival to cloud condensation nuclei. It is therefore crucial to understand how particles grow in the atmosphere. Insufficient experimental data has impeded a profound understanding of nano-particle growth under atmospheric conditions. Here we study nano-particle growth in the CLOUD (Cosmics Leaving OUtdoors Droplets) chamber, starting from the formation of molecular clusters. We present measured growth rates at sub-3 nm sizes with different atmospherically relevant concentrations of sulphuric acid, water, ammonia and dimethylamine. We find that atmospheric ions and small acid-base clusters, which are not generally accounted for in the measurement of sulphuric acid vapour, can participate in the growth process, leading to enhanced growth rates. The availability of compounds capable of stabilizing sulphuric acid clusters governs the magnitude of these effects and thus the exact growth mechanism. We bring these observations into a coherent framework and discuss their significance in the atmosphere.

  14. Investigations of the pore formation in the lead selenide films using glacial acetic acid- and nitric acid-based electrolyte

    PubMed Central

    2012-01-01

    We report a novel synthesis of porous PbSe layers on Si substrates by anodic electrochemical treatment of PbSe/CaF2/Si(111) epitaxial structures in an electrolyte solution based on glacial acetic acid and nitric acid. Electron microscopy, X-ray diffractometry, and local chemical microanalysis investigation results for the porous layers are presented. Average size of the synthesized mesopores with approximately 1010 cm−2 surface density was determined to be 22 nm. The observed phenomenon of the active selenium redeposition on the mesopore walls during anodic treatment is discussed. PMID:22726822

  15. Investigations of the pore formation in the lead selenide films using glacial acetic acid- and nitric acid-based electrolyte.

    PubMed

    Zimin, Sergey P; Gorlachev, Egor S; Naumov, Viktor V; Skok, Fedor O

    2012-01-01

    We report a novel synthesis of porous PbSe layers on Si substrates using anodic electrochemical treatment of PbSe/CaF2/Si(111) epitaxial structures in an electrolyte solution based on glacial acetic acid and nitric acid. Electron microscopy, x-ray diffractometry, and local chemical microanalysis investigations results for the porous layers are presented. Average size of the synthesized mesopores with ~1010 cm-2 surface density was determined to be 22 nm. The observed phenomenon of the active selenium redeposition on the mesopore walls during anodic treatment is discussed.

  16. Efficient voltammetric discrimination of free bilirubin from uric acid and ascorbic acid by a CVD nanographite-based microelectrode.

    PubMed

    Taurino, Irene; Van Hoof, Viviane; Magrez, Arnaud; Forró, László; De Micheli, Giovanni; Carrara, Sandro

    2014-12-01

    We report a novel electrochemical sensor based on nanographite grown on platinum microelectrodes for the determination of bilirubin in the presence of normal concentrations of albumin. The albumin is a protein with an intrinsic ability to bind the bilirubin therefore reducing the concentration of the free electroactive metabolite in human fluids. In addition, the proposed device permits the discrimination of free bilirubin from two interferents, uric acid and ascorbic acid, by the separation of their oxidation peaks in voltammetry. Preliminary measurements in human serum prove that the proposed nanostructured platform can be used to detect bilirubin.

  17. A Village-Based Intervention: Promoting Folic Acid Use among Rural Chinese Women

    PubMed Central

    Lin, Qian; Yang, Lina; Li, Fang; Qin, Hong; Li, Mingzhi; Chen, Jihua; Deng, Jing; Hu, Xiangying

    2017-01-01

    Background: Folic acid supplementation is effective in reducing the risk of neural tube defects (NTDs). However, the use of folic acid is low among rural women in China. Nutrition education can provide information about folic acid and encourage its use. The primary objective of this study was to test the effectiveness of a village-based nutrition intervention on folic acid use among rural women. Methods: Sixty villages were randomly selected using multiple-stage sampling and were divided into control and intervention groups. The intervention included nutritional education at village clinics, written materials, and text messages (SMS). Folic acid use knowledge and behavior was assessed at baseline and after the intervention. Results: Self-reported compliance with folic acid supplement use increased from 17.0%–29.2% at baseline to 41.7%–59.2% one year post-intervention. During the same period, the folic acid knowledge score in the intervention group increased from 3.07 to 3.65, significantly higher than the control group (3.11 to 3.35). Multivariate binary logistic regression showed that the women who received folic acid education and SMS intervention were more likely to comply with folic acid supplement recommendations. Conclusions: The results indicated that an integrated village-based folic acid education intervention may be an effective way of promoting folic acid use for the prevention of NTDs in rural women. PMID:28230798

  18. Bifunctional Organic Polymeric Catalysts with a Tunable Acid-Base Distance and Framework Flexibility

    PubMed Central

    Chen, Huanhui; Wang, Yanan; Wang, Qunlong; Li, Junhui; Yang, Shiqi; Zhu, Zhirong

    2014-01-01

    Acid-base bifunctional organic polymeric catalysts were synthesized with tunable structures. we demonstrated two synthesis approaches for structural fine-tune. In the first case, the framework flexibility was tuned by changing the ratio of rigid blocks to flexible blocks within the polymer framework. In the second case, we precisely adjusted the acid-base distance by distributing basic monomers to be adjacent to acidic monomers, and by changing the chain length of acidic monomers. In a standard test reaction for the aldol condensation of 4-nitrobenzaldehyde with acetone, the catalysts showed good reusability upon recycling and maintained relatively high conversion percentage. PMID:25267260

  19. Separation of thorium and uranium in nitric acid solution using silica based anion exchange resin.

    PubMed

    Chen, Yanliang; Wei, Yuezhou; He, Linfeng; Tang, Fangdong

    2016-09-30

    To separate thorium and uranium in nitric acid solution using anion exchange process, a strong base silica-based anion exchange resin (SiPyR-N4) was synthesized. Batch experiments were conducted and the separation factor of thorium and uranium in 9M nitric acid was about 10. Ion exchange chromatography was applied to separate thorium and uranium in different ratios. Uranium could be eluted by 9M nitric acid and thorium was eluted by 0.1M nitric acid. It was proved that thorium and uranium can be separated and recovered successfully by this method.

  20. Results from a Field Trial of the Radio Frequency Based Cylinder Accountability and Tracking System at the Global Nuclear Fuel Americas Fuel Fabrication Facility

    SciTech Connect

    Fitzgerald, Peter; Laughter, Mark D; Martyn, Rose; Pickett, Chris A; Rowe, Nathan C; Younkin, James R; Shephard, Adam M

    2010-01-01

    The Cylinder Accountability and Tracking System (CATS) is a tool designed for use by the International Atomic Energy Agency (IAEA) to improve overall inspector efficiency through real-time unattended monitoring of cylinder movements, site specific rules-based event detection, and the capability to integrate many types of monitoring technologies. The system is based on the tracking of cylinder movements using (radio frequency) RF tags, and the collection of data, such as accountability weights, that can be associated with the cylinders. This presentation will cover the installation and evaluation of the CATS at the Global Nuclear Fuels (GNF) fuel fabrication facility in Wilmington, NC. This system was installed to evaluate its safeguards applicability, operational durability under operating conditions, and overall performance. An overview of the system design and elements specific to the GNF deployment will be presented along with lessons learned from the installation process and results from the field trial.

  1. Prediction of solute kinetics, acid-base status, and blood volume changes during profiled hemodialysis.

    PubMed

    Ursino, M; Colí, L; Brighenti, C; Chiari, L; de Pascalis, A; Avanzolini, G

    2000-02-01

    A mathematical model of solute kinetics oriented to the simulation of hemodialysis is presented. It includes a three-compartment model of body fluids (plasma, interstitial and intracellular), a two-compartment description of the main solutes (K+, Na+, Cl-, urea, HCO3-, H+), and acid-base equilibrium through two buffer systems (bicarbonate and noncarbonic buffers). Tentative values for the main model parameters can be given a priori, on the basis of body weight and plasma concentration values measured before beginning the session. The model allows computation of the amount of sodium removed during hemodialysis, and may enable the prediction of plasma volume and osmolarity changes induced by a given sodium concentration profile in the dialysate and by a given ultrafiltration profile. Model predictions are compared with clinical data obtained during 11 different profiled hemodialysis sessions, both with all parameters assigned a priori, and after individual estimation of dialysances and mass-transfer coefficients. In most cases, the agreement between the time pattern of model solute concentrations in plasma and clinical data was satisfactory. In two sessions, blood volume changes were directly measured in the patient, and in both cases the agreement with model predictions was acceptable. The present model can be used to improve the dialysis session taking some characteristics of individual patients into account, in order to minimize intradialytic unbalances (such as hypotension or disequilibrium syndrome).

  2. Key volatile aroma compounds of lactic acid fermented malt based beverages - impact of lactic acid bacteria strains.

    PubMed

    Nsogning Dongmo, Sorelle; Sacher, Bertram; Kollmannsberger, Hubert; Becker, Thomas

    2017-08-15

    This study aims to define the aroma composition and key aroma compounds of barley malt wort beverages produced from fermentation using six lactic acid bacteria (LAB) strains. Gas chromatography mass spectrometry-olfactometry and flame ionization detection was employed; key aroma compounds were determined by means of aroma extract dilution analysis. Fifty-six detected volatile compounds were similar among beverages. However, significant differences were observed in the concentration of individual compounds. Key aroma compounds (flavor dilution (FD) factors ≥16) were β-damascenone, furaneol, phenylacetic acid, 2-phenylethanol, 4-vinylguaiacol, sotolon, methional, vanillin, acetic acid, nor-furaneol, guaiacol and ethyl 2-methylbutanoate. Furthermore, acetaldehyde had the greatest odor activity value of up to 4266. Sensory analyses revealed large differences in the flavor profile. Beverage from L. plantarum Lp. 758 showed the highest FD factors in key aroma compounds and was correlated to fruity flavors. Therefore, we suggest that suitable LAB strain selection may improve the flavor of malt based beverages.

  3. Improvement of ruthenium based decarboxylation of carboxylic acids

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The removal of oxygen atoms from biobased carboxylic acids is an attractive route to provide the drop in replacement feedstocks that industry needs to continue to provide high performance products. Through the use of ruthenium catalysis, an efficient method where this process can be accomplished on ...

  4. A new boronic acid based fluorescent reporter for catechol.

    PubMed

    Wu, Zhongyu; Li, Minyong; Fang, Hao; Wang, Binghe

    2012-12-01

    Catechol skeleton widely exists in natural products and bioactive substances. Fluorescent reporters which could recognize catechol are very promising for the construction of chemosensors to detect catechol and its derivatives in biological environment. Herein, we reported a novel catechol reporter, 2-(4-boronophenyl)quinoline-4-carboxylic acid, which exhibits significant fluorescent property changes upon binding catechol containing molecules in an aqueous solution.

  5. G protein activation kinetics and spillover of gamma-aminobutyric acid may account for differences between inhibitory responses in the hippocampus and thalamus.

    PubMed Central

    Destexhe, A; Sejnowski, T J

    1995-01-01

    We have developed a model of gamma-aminobutyric acid (GABA)ergic synaptic transmission mediated by GABAA and GABAB receptors, including cooperativity in the guanine nucleotide binding protein (G protein) cascade mediating the activation of K+ channels by GABAB receptors. If the binding of several G proteins is needed to activate the K+ channels, then only a prolonged activation of GABAB receptors evoked detectable currents. This could occur if strong stimuli evoked release in adjacent terminals and the spillover resulted in prolonged activation of the receptors, leading to inhibitory responses similar to those observed in hippocampal slices. The same model also reproduced thalamic GABAB responses to high-frequency bursts of stimuli. In this case, prolonged activation of the receptors was due to high-frequency release conditions. This model provides insights into the function of GABAB receptors in normal and epileptic discharges. Images Fig. 2 Fig. 4 PMID:7568165

  6. Enzymatic saccharification coupling with polyester recovery from cotton-based waste textiles by phosphoric acid pretreatment.

    PubMed

    Shen, Fei; Xiao, Wenxiong; Lin, Lili; Yang, Gang; Zhang, Yanzong; Deng, Shihuai

    2013-02-01

    In order to recycle the cotton-based waste textiles, a novel process was designed for pretreating waste textiles with phosphoric acid to recover polyester and fermentable sugar. The effects of pretreatment conditions including, phosphoric acid concentration, pretreatment temperature, time, and ratio of textiles and phosphoric acid were thoroughly investigated. Results indicated the mentioned four factors had significant influences on sugar and polyester recovery. Almost complete polyester recovery was achieved by enhancing phosphoric acid concentration, temperature and pretreatment time or reducing the ratio of textiles and phosphoric acid. However, these behaviors decreased the sugar recovery seriously. 100% polyester recovery with a maximum sugar recovery of 79.2% was achieved at the optimized conditions (85% phosphoric acid, 50°C, 7h, and the ratio of 1:15). According to the technical and cost-benefit analysis, it was technically feasible and potentially profitable to recover polyester and sugar from waste textiles by phosphoric acid pretreatment.

  7. Adsorption of Amino Acids and Glutamic Acid-Based Surfactants on Imogolite Clays.

    PubMed

    Bonini, Massimo; Gabbani, Alessio; Del Buffa, Stefano; Ridi, Francesca; Baglioni, Piero; Bordes, Romain; Holmberg, Krister

    2017-03-07

    Aluminum oxide surfaces are of utmost interest in different biotech applications, in particular for their use as adjuvants (i.e., booster of the immune response against infectious agents in vaccines production). In this framework, imogolite clays combine the chemical flexibility of an exposed alumina surface with 1D nanostructure. This work reports on the interaction between amino acids and imogolite, using turbidimetry, ζ-potential measurements, and Fourier transform infrared spectroscopy as main characterization tools. Amino acids with different side chain functional groups were investigated, showing that glutamic acid (Glu) has the strongest affinity for the imogolite surface. This was exploited to prepare a composite material made of a synthetic surfactant bearing a Glu polar head and a hydrophobic C12 alkyl tail, adsorbed onto the surface of imogolite. The adsorption of a model drug (rhodamine B isothiocyanate) by the hybrid was evaluated both in water and in physiological saline conditions. The findings of this paper suggest that the combination between the glutamate headgroup and imogolite represents a promising platform for the fabrication of hybrid nanostructures with tailored functionalities.

  8. Quality of rivers of the United States, 1975 water year; based on the National Stream Quality Accounting Network (NASQAN)

    USGS Publications Warehouse

    Briggs, John C.; Ficke, John F.

    1977-01-01

    The National Stream Quality Accounting Network (NASQAN) was established by the U.S. Geological Survey to provide a nationally uniform basis for continuously assessing the quality of U.S. rivers. Stations generally are at the downstream end of hydrologic accounting units in order to measure the quantity and quality of water flowing from the units. The 1975 water year was the first year of operation of the network that represents essentially all of the accounting units and thereby describes the water- quality of the entire country. Data are available on a large number of water-quality constituents measured at 345 stations during the 1975 water year. Temperature data (usually continuous or daily measurements) from NASQAN stations were fitted to a first order harmonic equation and the parameters for the harmonic function are reported for each station. Mean temperatures generally range from 5°-10°C in the North to more than 20°C along the southern border of the continental United States and in Hawaii and Puerto Rico; means were less than 10°C at 63 stations and greater than 25°C at only 7 stations. Amplitudes of the temperature curves are greatest (greater than 12°C) for the streams at midlatitudes and in the Great and Central Plains, and they are smallest for the subtropical and cold-climate streams. Considering chemical and biological characteristics of U.S. streams as described by NASQAN data, water quality is best (by many standards) in the Northeast, Southeast, and Northwest. Waters there generally are low in dissolved solids and major and minor chemical constituents, generally are soft (except in Florida), and carry relatively small amounts of sediment. These conditions mainly reflect the geology of the regions and the relatively large amounts of precipitation. However, many of these waters show the effects of pollution and carry moderate or high levels of major nutrients and have correspondingly high populations of attached and floating plants. High counts

  9. Lewis Acid-Base Adduct Approach for High Efficiency Perovskite Solar Cells.

    PubMed

    Lee, Jin-Wook; Kim, Hui-Seon; Park, Nam-Gyu

    2016-02-16

    Since the first report on the long-term durable 9.7% solid-state perovskite solar cell employing methylammonium lead iodide (CH3NH3PbI3), mesoporous TiO2, and 2,2',7,7'-tetrakis[N,N-di(4-methoxyphenyl)amino]-9,9'-spirobifluorene (spiro-MeOTAD) in 2012, following the seed technologies on perovskite-sensitized liquid junction solar cells in 2009 and 2011, a surge of interest has been focused on perovskite solar cells due to superb photovoltaic performance and extremely facile fabrication processes. The power conversion efficiency (PCE) of perovskite solar cells reached 21% in a very short period of time. Such an unprecedentedly high photovoltaic performance is due to the intrinsic optoelectronic property of organolead iodide perovskite material. Moreover, a high dielectric constant, sub-millimeter scale carrier diffusion length, an underlying ferroelectric property, and ion migration behavior can make organolead halide perovskites suitable for multifunctionality. Thus, besides solar cell applications, perovskite material has recently been applied to a variety fields of materials science such as photodetectors, light emitting diodes, lasing, X-ray imaging, resistive memory, and water splitting. Regardless of application areas, the growth of a well-defined perovskite layer with high crystallinity is essential for effective utilization of its excellent physicochemical properties. Therefore, an effective methodology for preparation of high quality perovskite layers is required. In this Account, an effective methodology for production of high quality perovskite layers is described, which is the Lewis acid-base adduct approach. In the solution process to form the perovskite layer, the key chemicals of CH3NH3I (or HC(NH2)2I) and PbI2 are used by dissolving them in polar aprotic solvents. Since polar aprotic solvents bear oxygen, sulfur, or nitrogen, they can act as a Lewis base. In addition, the main group compound PbI2 is known to be a Lewis acid. Thus, PbI2 has a chance

  10. Influence of pasture-based feeding systems on fatty acids, organic acids and volatile organic flavour compounds in yoghurt.

    PubMed

    Akbaridoust, Ghazal; Plozza, Tim; Trenerry, V Craige; Wales, William J; Auldist, Martin J; Ajlouni, Said

    2015-08-01

    The influence of different pasture-based feeding systems on fatty acids, organic acids and volatile organic flavour compounds in yoghurt was studied. Pasture is the main source of nutrients for dairy cows in many parts of the world, including southeast Australia. Milk and milk products produced in these systems are known to contain a number of compounds with positive effects on human health. In the current study, 260 cows were fed supplementary grain and forage according to one of 3 different systems; Control (a traditional pasture based diet offered to the cows during milking and in paddock), PMR1 (a partial mixed ration which contained the same supplement as Control but was offered to the cows as a partial mixed ration on a feedpad), PMR 2 (a differently formulated partial mixed ration compared to Control and PMR1 which was offered to the cows on a feedpad). Most of the yoghurt fatty acids were influenced by feeding systems; however, those effects were minor on organic acids. The differences in feeding systems did not lead to the formation of different volatile organic flavour compounds in yoghurt. Yet, it did influence the relative abundance of these components.

  11. Synergistic effects on enantioselectivity of zwitterionic chiral stationary phases for separations of chiral acids, bases, and amino acids by HPLC.

    PubMed

    Hoffmann, Christian V; Pell, Reinhard; Lämmerhofer, Michael; Lindner, Wolfgang

    2008-11-15

    In an attempt to overcome the limited applicability scope of earlier proposed Cinchona alkaloid-based chiral weak anion exchangers (WAX) and recently reported aminosulfonic acid-based chiral strong cation exchangers (SCX), which are conceptionally restricted to oppositely charged solutes, their individual chiral selector (SO) subunits have been fused in a combinatorial synthesis approach into single, now zwitterionic, chiral SO motifs. The corresponding zwitterionic ion-exchange-type chiral stationary phases (CSPs) in fact combined the applicability spectra of the parent chiral ion exchangers allowing for enantioseparations of chiral acids and amine-type solutes in liquid chromatography using polar organic mode with largely rivaling separation factors as compared to the parent WAX and SCX CSPs. Furthermore, the application spectrum could be remarkably expanded to various zwitterionic analytes such as alpha- and beta-amino acids and peptides. A set of structurally related yet different CSPs consisting of either a quinine or quinidine alkaloid moiety as anion-exchange subunit and various chiral or achiral amino acids as cation-exchange subunits enabled us to derive structure-enantioselectivity relationships, which clearly provided strong unequivocal evidence for synergistic effects of the two oppositely charged ion-exchange subunits being involved in molecular recognition of zwitterionic analytes by zwitterionic SOs driven by double ionic coordination.

  12. Model-Based Assessments to Support Learning and Accountability: The Evolution of CRESST's Research on Multiple-Purpose Measures

    ERIC Educational Resources Information Center

    Baker, Eva L.

    2007-01-01

    This article describes the history, evidence warrants, and evolution of the Center for Research on Evaluation, Standards, and Student Testing's (CRESST) model-based assessments. It considers alternative interpretations of scientific or practical models and illustrates how model-based assessment addresses both definitions. The components of the…

  13. Visual and Spatial Working Memory Are Not that Dissociated after All: A Time-Based Resource-Sharing Account

    ERIC Educational Resources Information Center

    Vergauwe, Evie; Barrouillet, Pierre; Camos, Valerie

    2009-01-01

    Examinations of interference between visual and spatial materials in working memory have suggested domain- and process-based fractionations of visuo-spatial working memory. The present study examined the role of central time-based resource sharing in visuo-spatial working memory and assessed its role in obtained interference patterns. Visual and…

  14. Resonance Energy Transfer-Based Nucleic Acid Hybridization Assays on Paper-Based Platforms Using Emissive Nanoparticles as Donors.

    PubMed

    Doughan, Samer; Noor, M Omair; Han, Yi; Krull, Ulrich J

    2017-01-01

    Quantum dots (QDs) and upconverting nanoparticles (UCNPs) are luminescent nanoparticles (NPs) commonly used in bioassays and biosensors as resonance energy transfer (RET) donors. The narrow and tunable emissions of both QDs and UCNPs make them versatile RET donors that can be paired with a wide range of acceptors. Ratiometric signal processing that compares donor and acceptor emission in RET-based transduction offers improved precision, as it accounts for fluctuations in the absolute photoluminescence (PL) intensities of the donor and acceptor that can result from experimental and instrumental variations. Immobilizing NPs on a solid support avoids problems such as those that can arise with their aggregation in solution, and allows for facile layer-by-layer assembly of the interfacial chemistry. Paper is an attractive solid support for the development of point-of-care diagnostic assays given its ubiquity, low-cost, and intrinsic fluid transport by capillary action. Integration of nanomaterials with paper-based analytical devices (PADs) provides avenues to augment the analytical performance of PADs, given the unique optoelectronic properties of nanomaterials. Herein, we describe methodology for the development of PADs using QDs and UCNPs as RET donors for optical transduction of nucleic acid hybridization. Immobilization of green-emitting QDs (gQDs) on imidazole functionalized cellulose paper is described for use as RET donors with Cy3 molecular dye as acceptors for the detection of SMN1 gene fragment. We also describe the covalent immobilization of blue-emitting UCNPs on aldehyde modified cellulose paper for use as RET donors with orange-emitting QDs (oQDs) as acceptors for the detection of HPRT1 gene fragment. The data described herein is acquired using an epifluorescence microscope, and can also be collected using technology such as a typical electronic camera.

  15. Accounting Fundamentals for Non-Accountants

    EPA Pesticide Factsheets

    The purpose of this module is to provide an introduction and overview of accounting fundamentals for non-accountants. The module also covers important topics such as communication, internal controls, documentation and recordkeeping.

  16. Accountability and Sanctions in English Schools

    ERIC Educational Resources Information Center

    West, Anne; Mattei, Paola; Roberts, Jonathan

    2011-01-01

    This paper focuses on accountability in school-based education in England. It explores notions of accountability and proposes a new framework for its analysis. It then identifies a number of types of accountability which are present in school-based education, and discusses each in terms of who is accountable to whom and for what. It goes on to…

  17. Enzymatic synthesis of palm olein-based fatty thiohydroxamic acids.

    PubMed

    Al-Mulla, Emad A Jaffar; Yunus, Wan Md Zin Wan; Ibrahim, Nor Azowa Bt; Rahman, Mohd Zaki Ab

    2010-01-01

    Fatty thiohydroxamic acids (FTAs) have been successfully synthesized from palm olein and thiohydroxamic acid by a one-step lipase catalyzed reaction. The use of immobilized lipase (Lipozyme RMIM) as the catalyst for the preparation reaction provides an easy isolation of the enzyme from the products and other components in the reaction mixture. The FTAs were characterized using Fourier transform infrared (FTIR) spectroscopy, proton nuclear magnetic resonance ((1)H NMR) technique and elemental analysis. The highest conversion percentage (95 %) was obtained when the process was carried out for 30 hours using urea to palm oil ratio of 6.0: 1.0 at 40 °C. The method employed offers several advantages such as renewable and abundant of the raw material, simple reaction procedure, environmentally friendly process and high yield of the product.

  18. Accounting for failure: risk-based regulation and the problems of ensuring healthcare quality in the NHS.

    PubMed

    Beaussier, Anne-Laure; Demeritt, David; Griffiths, Alex; Rothstein, Henry

    2016-05-18

    In this paper, we examine why risk-based policy instruments have failed to improve the proportionality, effectiveness, and legitimacy of healthcare quality regulation in the National Health Service (NHS) in England. Rather than trying to prevent all possible harms, risk-based approaches promise to rationalise and manage the inevitable limits of what regulation can hope to achieve by focusing regulatory standard-setting and enforcement activity on the highest priority risks, as determined through formal assessments of their probability and consequences. As such, risk-based approaches have been enthusiastically adopted by healthcare quality regulators over the last decade. However, by drawing on historical policy analysis and in-depth interviews with 15 high-level UK informants in 2013-2015, we identify a series of practical problems in using risk-based policy instruments for defining, assessing, and ensuring compliance with healthcare quality standards. Based on our analysis, we go on to consider why, despite a succession of failures, healthcare regulators remain committed to developing and using risk-based approaches. We conclude by identifying several preconditions for successful risk-based regulation: goals must be clear and trade-offs between them amenable to agreement; regulators must be able to reliably assess the probability and consequences of adverse outcomes; regulators must have a range of enforcement tools that can be deployed in proportion to risk; and there must be political tolerance for adverse outcomes.

  19. Accounting for failure: risk-based regulation and the problems of ensuring healthcare quality in the NHS

    PubMed Central

    Beaussier, Anne-Laure; Demeritt, David; Griffiths, Alex; Rothstein, Henry

    2016-01-01

    In this paper, we examine why risk-based policy instruments have failed to improve the proportionality, effectiveness, and legitimacy of healthcare quality regulation in the National Health Service (NHS) in England. Rather than trying to prevent all possible harms, risk-based approaches promise to rationalise and manage the inevitable limits of what regulation can hope to achieve by focusing regulatory standard-setting and enforcement activity on the highest priority risks, as determined through formal assessments of their probability and consequences. As such, risk-based approaches have been enthusiastically adopted by healthcare quality regulators over the last decade. However, by drawing on historical policy analysis and in-depth interviews with 15 high-level UK informants in 2013–2015, we identify a series of practical problems in using risk-based policy instruments for defining, assessing, and ensuring compliance with healthcare quality standards. Based on our analysis, we go on to consider why, despite a succession of failures, healthcare regulators remain committed to developing and using risk-based approaches. We conclude by identifying several preconditions for successful risk-based regulation: goals must be clear and trade-offs between them amenable to agreement; regulators must be able to reliably assess the probability and consequences of adverse outcomes; regulators must have a range of enforcement tools that can be deployed in proportion to risk; and there must be political tolerance for adverse outcomes. PMID:27499677

  20. Accounting: Accountants Need Verbal Skill Training

    ERIC Educational Resources Information Center

    Whitaker, Bruce L.

    1978-01-01

    Verbal skills training is one aspect of accounting education not usually included in secondary and postsecondary accounting courses. The author discusses the need for verbal competency and methods of incorporating it into accounting courses, particularly a variation of the Keller plan of individualized instruction. (MF)

  1. Surveying Students' Conceptual and Procedural Knowledge of Acid-Base Behavior of Substances

    ERIC Educational Resources Information Center

    Furio-Mas, Carles; Calatayud, Maria-Luisa; Barcenas, Sergio L.

    2007-01-01

    By the end of their high school studies, students should be able to understand macroscopic and sub-microscopic conceptualization of acid-base behavior and the relationship between these conceptual models. The aim of this article is to ascertain whether grade-12 students have sufficient background knowledge to explain the properties of acids,…

  2. Stereoselective assembly of amino acid-based metal-biomolecule nanofibers.

    PubMed

    Wu, Hong; Tian, Chunyong; Zhang, Yufei; Yang, Chen; Zhang, Songping; Jiang, Zhongyi

    2015-04-14

    A series of amino acid-based metal-biomolecule nanofibers are fabricated through a coordination-directed assembly process. The chirality and carbon chain length of the amino acids exert a pronounced influence on the assembly process. This study may be extended to design diverse kinds of 1-D metal-biomolecule frameworks (MBioFs).

  3. Biodegradable Photo-Crosslinked Thin Polymer Networks Based on Vegetable Oil Hydroxyfatty Acids

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Novel crosslinked thin polymer networks based on vegetable oil hydroxyfatty acids (HFAs) were prepared by UV photopolymerization and their mechanical properties were evaluated. Two raw materials, castor oil and 7,10-dihydroxy-8(E)-octadecenoic acid (DOD) were used as sources of mono- and di-HFAs, r...

  4. EFFECTIVENESS OF USING DILUTE OXALIC ACID TO DISSOLVEHIGH LEVEL WASTE IRON BASED SLUDGE SIMULANT

    SciTech Connect

    Ketusky, E

    2008-07-11

    At the Savannah River Site (SRS), near Aiken South Carolina, there is a crucial need to remove residual quantities of highly radioactive iron-based sludge from large select underground storage tanks (e.g., 19,000 liters of sludge per tank), in order to support tank closure. The use of oxalic acid is planned to dissolve the residual sludge, hence, helping in the removal. Based on rigorous testing, primarily using 4 and 8 wt% oxalic acid solutions, it was concluded that the more concentrated the acid, the greater the amount of residual sludge that would be dissolved; hence, a baseline technology on using 8 wt% oxalic acid was developed. In stark contrast to the baseline technology, reports from other industries suggest that the dissolution will most effectively occur at 1 wt% oxalic acid (i.e., maintaining the pH near 2). The driver for using less oxalic acid is that less (i.e., moles) would decrease the severity of the downstream impacts (i.e., required oxalate solids removal efforts). To determine the initial feasibility of using 1 wt% acid to dissolve > 90% of the sludge solids, about 19,000 liters of representative sludge was modeled using about 530,000 liters of 0 to 8 wt% oxalic acid solutions. With the chemical thermodynamic equilibrium based software results showing that 1 wt% oxalic acid could theoretically work, simulant dissolution testing was initiated. For the dissolution testing, existing simulant was obtained, and an approximate 20 liter test rig was built. Multiple batch dissolutions of both wet and air-dried simulant were performed. Overall, the testing showed that dilute oxalic acid dissolved a greater fraction of the stimulant and resulted in a significantly larger acid effectiveness (i.e., grams of sludge dissolved/mole of acid) than the baseline technology. With the potential effectiveness confirmed via simulant testing, additional testing, including radioactive sludge testing, is planned.

  5. Polylactic Acid-Based Polymer Blends for Durable Applications

    NASA Astrophysics Data System (ADS)

    Finniss, Adam

    There has been considerable scientific interest in both research and commercial communities as of late in the area of biologically based or sourced plastics. As the consumption of petroleum rises and concerns about climate change increase, this field is likely to grow even larger. One bioplastic that has received a great deal of attention is polylactic acid (PLA). In the past, this material was used mainly in medical or specialty applications, but advancements in manufacturing have led to a desire to use PLA more widely, especially in durable applications. Unfortunately, PLA has several drawbacks that hinder more widespread usage of the material as a durable item: it has low ductility and impact strength in bulk applications, along with poor stability in the face of heat, humidity or liquid media. To combat these deficiencies, a number of techniques were investigated. Samples were annealed to create crystalline domains that would improve mechanical properties and reduce diffusion, blended with graphene to create barriers to diffusion throughout the material, or compounded with a polycarbonate (PC) polymer phase to protect the PLA phase and to enhance the mechanical properties of the blend. If a material containing biologically sourced components with good mechanical properties can be created, it would be desirable for durable uses such as electronics components or as an automotive grade resin. Crystallization experiments were carried out in a differential scanning calorimeter to determine the effects of heat treatment and additives on the rather slow crystallization kinetics of PLA polymer. It was determined that the blending in of the PC phase did not significantly alter the kinetics or mechanism of crystal growth. The addition of graphene to any PC/PLA formulation served as a nucleating agent which speeded up the crystallization kinetics markedly, in some cases by several orders of magnitude. Results obtained from these experiments were internally consistent

  6. Essentials in the diagnosis of acid-base disorders and their high altitude application.

    PubMed

    Paulev, P E; Zubieta-Calleja, G R

    2005-09-01

    This report describes the historical development in the clinical application of chemical variables for the interpretation of acid-base disturbances. The pH concept was already introduced in 1909. Following World War II, disagreements concerning the definition of acids and bases occurred, and since then two strategies have been competing. Danish scientists in 1923 defined an acid as a substance able to give off a proton at a given pH, and a base as a substance that could bind a proton, whereas the North American Singer-Hasting school in 1948 defined acids as strong non-buffer anions and bases as non-buffer cations. As a consequence of this last definition, electrolyte disturbances were mixed up with real acid-base disorders and the variable, strong ion difference (SID), was introduced as a measure of non-respiratory acid-base disturbances. However, the SID concept is only an empirical approximation. In contrast, the Astrup/Siggaard-Andersen school of scientists, using computer strategies and the Acid-base Chart, has made diagnosis of acid-base disorders possible at a glance on the Chart, when the data are considered in context with the clinical development. Siggaard-Andersen introduced Base Excess (BE) or Standard Base Excess (SBE) in the extracellular fluid volume (ECF), extended to include the red cell volume (eECF), as a measure of metabolic acid-base disturbances and recently replaced it by the term Concentration of Titratable Hydrogen Ion (ctH). These two concepts (SBE and ctH) represent the same concentration difference, but with opposite signs. Three charts modified from the Siggaard-Andersen Acid-Base Chart are presented for use at low, medium and high altitudes of 2500 m, 3500 m, and 4000 m, respectively. In this context, the authors suggest the use of Titratable Hydrogen Ion concentration Difference (THID) in the extended extracellular fluid volume, finding it efficient and better than any other determination of the metabolic component in acid-base

  7. Synthesis and characterization of hydrolytically degradable copolyester biomaterials based on glycolic acid, sebacic acid and ethylene glycol.

    PubMed

    Simitzis, J; Soulis, S; Triantou, D; Zoumpoulakis, L; Zotali, P

    2011-12-01

    Copolyesters of glycolic acid (G) combined with sebacic acid (S) and ethylene glycol were synthesized in different molar ratios (G: 0-100% and S: 100-0%) and their hydrolytic degradation was studied and correlated with their structures. Based on the FTIR spectra of the homopolyesters and copolyesters and the normalized peak intensity of the I(2918), I(2848) and I(1087) for the corresponding wavenumbers, it is concluded that the I(2918) and the I(2848) are in accordance with the mean number degree of polymerization of ethylene sebacate units and the I(1087) is in accordance with the mean number degree of polymerization of glycolate units. Based on the XRD diffractograms, poly(ethylene sebacate) and poly(glycolic acid) belong to the monoclinic and the orthorhombic crystal system, respectively and both have higher crystallinity than the copolyesters. The experimental data of the hydrolytic degradation were fitted with exponential rise to maximum type functions using two-parameter model and four-parameter model. Three regions can been distinguished for the hydrolytic degradation by decreasing the molar feed ratio of sebacic acid, which are correlated with the changes of crystallinity. Two copolyesters are proposed: first the copolyester with high amount of glycolate units (S10G90) having higher hydrolytic degradation than G100 and second the copolyester with equal amount of glycolate and ethylene sebacate units (S50G50), having lower hydrolytic degradation than G100. These hydrolytically degradable copolyesters are soluble in common organic solvents, opposite to poly(glycolic acid) and could have perspectives for biomedical applications.

  8. The solubilization of fatty acids in systems based on block copolymers and nonionic surfactants

    NASA Astrophysics Data System (ADS)

    Mirgorodskaya, A. B.; Yatskevich, E. I.; Zakharova, L. Ya.

    2010-12-01

    The solubilizing action of micellar, microemulsion, and polymer-colloid systems formed on the basis of biologically compatible amphiphilic polymers and nonionic surfactants on capric, lauric, palmitic, and stearic acids was characterized quantitatively. Systems based on micelle forming oxyethyl compounds increased the solubility of fatty acids by more than an order of magnitude. Acid molecules incorporated into micelles increased their size and caused structural changes. Solubilization was accompanied by complete or partial destruction of intrinsic acid associates and an increase in their p K a by 1.5-2 units compared with water.

  9. Acid-base properties of the Fe(CN){sub 6}{sup 3-}/Fe(CN){sub 6}{sup 4-} redox couple in the presence of various background mineral acids and salts

    SciTech Connect

    Crozes, X.; Blanc, P.; Moisy, P.; Cote, G.

    2012-04-15

    The acid-base behavior of Fe(CN){sub 6}{sup 4-} was investigated by measuring the formal potentials of the Fe(CN){sub 6}{sup 3-}/Fe(CN){sub 6}{sup 4-} couple over a wide range of acidic and neutral solution compositions. The experimental data were fitted to a model taking into account the protonated forms of Fe(CN){sub 6}{sup 4-} and using values of the activities of species in solution, calculated with a simple solution model and a series of binary data available in the literature. The fitting needed to take account of the protonated species HFe(CN){sub 6}{sup 3-} and H{sub 2}Fe(CN){sub 6}{sup 2-}, already described in the literature, but also the species H{sub 3}Fe(CN){sub 6}{sup -} (associated with the acid-base equilibrium H{sub 3}Fe(CN){sub 6}{sup -} ↔ H{sub 2}Fe(CN){sub 6}{sup 2-} + H{sup +}). The acidic dissociation constants of HFe(CN){sub 6}{sup 3-}, H{sub 2}Fe(CN){sub 6}{sup 2-} and H{sub 3}Fe(CN){sub 6}{sup -} were found to be pK(1)(II) = 3.9 ± 0.1, pK(2)(II) = 2.0 ± 0.1, and pK(3)(II) = 0.0 ± 0.1, respectively. These constants were determined by taking into account that the activities of the species are independent of the ionic strength. (authors)

  10. Comparison of Methods to Account for Relatedness in Genome-Wide Association Studies with Family-Based Data

    PubMed Central

    Eu-ahsunthornwattana, Jakris; Miller, E. Nancy; Fakiola, Michaela; Jeronimo, Selma M. B.; Blackwell, Jenefer M.; Cordell, Heather J.

    2014-01-01

    Approaches based on linear mixed models (LMMs) have recently gained popularity for modelling population substructure and relatedness in genome-wide association studies. In the last few years, a bewildering variety of different LMM methods/software packages have been developed, but it is not always clear how (or indeed whether) any newly-proposed method differs from previously-proposed implementations. Here we compare the performance of several LMM approaches (and software implementations, including EMMAX, GenABEL, FaST-LMM, Mendel, GEMMA and MMM) via their application to a genome-wide association study of visceral leishmaniasis in 348 Brazilian families comprising 3626 individuals (1972 genotyped). The implementations differ in precise details of methodology implemented and through various user-chosen options such as the method and number of SNPs used to estimate the kinship (relatedness) matrix. We investigate sensitivity to these choices and the success (or otherwise) of the approaches in controlling the overall genome-wide error-rate for both real and simulated phenotypes. We compare the LMM results to those obtained using traditional family-based association tests (based on transmission of alleles within pedigrees) and to alternative approaches implemented in the software packages MQLS, ROADTRIPS and MASTOR. We find strong concordance between the results from different LMM approaches, and all are successful in controlling the genome-wide error rate (except for some approaches when applied naively to longitudinal data with many repeated measures). We also find high correlation between LMMs and alternative approaches (apart from transmission-based approaches when applied to SNPs with small or non-existent effects). We conclude that LMM approaches perform well in comparison to competing approaches. Given their strong concordance, in most applications, the choice of precise LMM implementation cannot be based on power/type I error considerations but must instead be

  11. Influence of dissolved organic carbon content on modelling natural organic matter acid-base properties.

    PubMed

    Garnier, Cédric; Mounier, Stéphane; Benaïm, Jean Yves

    2004-10-01

    Natural organic matter (NOM) behaviour towards proton is an important parameter to understand NOM fate in the environment. Moreover, it is necessary to determine NOM acid-base properties before investigating trace metals complexation by natural organic matter. This work focuses on the possibility to determine these acid-base properties by accurate and simple titrations, even at low organic matter concentrations. So, the experiments were conducted on concentrated and diluted solutions of extracted humic and fulvic acid from Laurentian River, on concentrated and diluted model solutions of well-known simple molecules (acetic and phenolic acids), and on natural samples from the Seine river (France) which are not pre-concentrated. Titration experiments were modelled by a 6 acidic-sites discrete model, except for the model solutions. The modelling software used, called PROSECE (Programme d'Optimisation et de SpEciation Chimique dans l'Environnement), has been developed in our laboratory, is based on the mass balance equilibrium resolution. The results obtained on extracted organic matter and model solutions point out a threshold value for a confident determination of the studied organic matter acid-base properties. They also show an aberrant decreasing carboxylic/phenolic ratio with increasing sample dilution. This shift is neither due to any conformational effect, since it is also observed on model solutions, nor to ionic strength variations which is controlled during all experiments. On the other hand, it could be the result of an electrode troubleshooting occurring at basic pH values, which effect is amplified at low total concentration of acidic sites. So, in our conditions, the limit for a correct modelling of NOM acid-base properties is defined as 0.04 meq of total analysed acidic sites concentration. As for the analysed natural samples, due to their high acidic sites content, it is possible to model their behaviour despite the low organic carbon concentration.

  12. MATERIAL CONTROL ACCOUNTING INMM

    SciTech Connect

    Hasty, T.

    2009-06-14

    Since 1996, the Mining and Chemical Combine (MCC - formerly known as K-26), and the United States Department of Energy (DOE) have been cooperating under the cooperative Nuclear Material Protection, Control and Accounting (MPC&A) Program between the Russian Federation and the U.S. Governments. Since MCC continues to operate a reactor for steam and electricity production for the site and city of Zheleznogorsk which results in production of the weapons grade plutonium, one of the goals of the MPC&A program is to support implementation of an expanded comprehensive nuclear material control and accounting (MC&A) program. To date MCC has completed upgrades identified in the initial gap analysis and documented in the site MC&A Plan and is implementing additional upgrades identified during an update to the gap analysis. The scope of these upgrades includes implementation of MCC organization structure relating to MC&A, establishing material balance area structure for special nuclear materials (SNM) storage and bulk processing areas, and material control functions including SNM portal monitors at target locations. Material accounting function upgrades include enhancements in the conduct of physical inventories, limit of error inventory difference procedure enhancements, implementation of basic computerized accounting system for four SNM storage areas, implementation of measurement equipment for improved accountability reporting, and both new and revised site-level MC&A procedures. This paper will discuss the implementation of MC&A upgrades at MCC based on the requirements established in the comprehensive MC&A plan developed by the Mining and Chemical Combine as part of the MPC&A Program.

  13. Antimicrobial polyurethane thermosets based on undecylenic acid: synthesis and evaluation.

    PubMed

    Lluch, Cristina; Esteve-Zarzoso, Braulio; Bordons, Albert; Lligadas, Gerard; Ronda, Juan C; Galià, Marina; Cádiz, Virginia

    2014-08-01

    In the present study, plant oil-derived surface-modifiable polyurethane thermosets are presented. Polyol synthesis is carried out taking advantage of thiol-yne photopolymerization of undecylenic acid derivatives containing methyl ester or hydroxyl moieties. The prepared methyl ester-containing polyurethanes allow surface modification treatment to enhance their hydrophilicity and impart antimicrobial activity through the following two steps: i) grafting poly(propylene glycol) monoamine (Jeffamine M-600) via aminolysis and ii) Jeffamine M-600 layer complexation with iodine. The antimicrobial activity of the iodine-containing polyurethanes is demonstrated by its capacity to inhibit the growth of Staphylococcus aureus, and Candida albicans in agar media.

  14. Elongated and substituted triazine-based tricarboxylic acid linkers for MOFs

    PubMed Central

    Klinkebiel, Arne; Beyer, Ole; Malawko, Barbara

    2016-01-01

    New triazine-based tricarboxylic acid linkers were prepared as elongated relatives of triazinetribenzoic acid (TATB). Additionally, functional groups (NO2, NH2, OMe, OH) were introduced for potential post-synthetic modification (PSM) of MOFs. Functionalized tris(4-bromoaryl)triazine “cores” (3a,3b) were obtained by unsymmetric trimerization mixing one equivalent of an acid chloride (OMe or NO2 substituted) with two equivalents of an unsubstituted nitrile. Triple Suzuki coupling of the cores 3 with suitable phenyl- and biphenylboronic acid derivatives provided elongated tricarboxylic acid linkers as carboxylic acids 17 and 20 or their esters 16 and 19. Reduction of the nitro group and cleavage of the methoxy group gave the respective amino and hydroxy-substituted triazine linkers. PMID:28144293

  15. 2-Keto acids based biosynthesis pathways for renewable fuels and chemicals.

    PubMed

    Tashiro, Yohei; Rodriguez, Gabriel M; Atsumi, Shota

    2015-03-01

    Global energy and environmental concerns have driven the development of biological chemical production from renewable sources. Biological processes using microorganisms are efficient and have been traditionally utilized to convert biomass (i.e., glucose) to useful chemicals such as amino acids. To produce desired fuels and chemicals with high yield and rate, metabolic pathways have been enhanced and expanded with metabolic engineering and synthetic biology approaches. 2-Keto acids, which are key intermediates in amino acid biosynthesis, can be converted to a wide range of chemicals. 2-Keto acid pathways were engineered in previous research efforts and these studies demonstrated that 2-keto acid pathways have high potential for novel metabolic routes with high productivity. In this review, we discuss recently developed 2-keto acid-based pathways.

  16. Effects of Problem-Based Learning on Recognition Learning and Transfer Accounting for GPA and Goal Orientation

    ERIC Educational Resources Information Center

    Bergstrom, Cassendra M.; Pugh, Kevin J.; Phillips, Michael M.; Machlev, Moshe

    2016-01-01

    Conflicting research results have stirred controversy over the effectiveness of problem-based learning (PBL) compared to direct instruction at fostering content learning, particularly for novices. We addressed this by investigating effectiveness with respect to recognition learning and transfer and conducting an aptitude-treatment interaction…

  17. A systematic account of the genus Plagiostoma (Gnomoniaceae, Diaporthales) based on morphology, host-associations, and a four gene phylogeny

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The genus Plagiostoma inhabits leaves and branches of a range of woody and herbaceous plant families in the temperate northern hemisphere. Based on analyses of morphological, cultural, and molecular data, Plagiostoma is reviewed and monographed. The morphological data include shape and size of perit...

  18. Towards Project-Based Learning: An Autoethnographic Account of One Assistant Professor's Struggle to Be a Better Teacher

    ERIC Educational Resources Information Center

    Greer, Wil

    2016-01-01

    This paper outlines an approach to incorporating project-based learning (PBL) in a master's level educational administration diversity course. It draws on the qualitative methodology of autoethnography, and details the characteristics of this technique. In alignment with that method, the author discusses his positionality and engages in…

  19. Iridophores and not carotenoids account for chromatic variation of carotenoid-based coloration in common lizards (Lacerta vivipara).

    PubMed

    San-Jose, Luis M; Granado-Lorencio, Fernando; Sinervo, Barry; Fitze, Patrick S

    2013-03-01

    Abstract Carotenoids typically need reflective background components to shine. Such components, iridophores, leucophores, and keratin- and collagen-derived structures, are generally assumed to show no or little environmental variability. Here, we investigate the origin of environmentally induced variation in the carotenoid-based ventral coloration of male common lizards (Lacerta vivipara) by investigating the effects of dietary carotenoids and corticosterone on both carotenoid- and background-related reflectance. We observed a general negative chromatic change that was prevented by β-carotene supplementation. However, chromatic changes did not result from changes in carotenoid-related reflectance or skin carotenoid content but from changes in background-related reflectance that may have been mediated by vitamin A1. An in vitro experiment showed that the encountered chromatic changes most likely resulted from changes in iridophore reflectance. Our findings demonstrate that chromatic variation in carotenoid-based ornaments may not exclusively reflect differences in integumentary carotenoid content and, hence, in qualities linked to carotenoid deposition (e.g., foraging ability, immune response, or antioxidant capacity). Moreover, skin carotenoid content and carotenoid-related reflectance were related to male color polymorphism, suggesting that carotenoid-based coloration of male common lizards is a multicomponent signal, with iridophores reflecting environmental conditions and carotenoids reflecting genetically based color morphs.

  20. 20 CFR 404.408 - Reduction of benefits based on disability on account of receipt of certain other disability...

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 20 Employees' Benefits 2 2013-04-01 2013-04-01 false Reduction of benefits based on disability on... of $507.90 and a monthly public disability benefit of $410.00 from the State. Eighty percent of Harold's average current earnings is $800.00. Because this amount ($800.00) is higher than...