WorldWideScience

Sample records for subarctic electronic resource

  1. ELECTRONIC HUMAN RESOURCE MANAGEMENT

    OpenAIRE

    Dr. M. Panneerselvam

    2017-01-01

    Electronic Human Resource Management is an essence the revolution of human resource functions to management and employees. These functions are typically used via intranet and web technology. This helps the organization to improve their standards where they can able to review and forward. All those documents can be viewed within a fraction of second with help of client and server links. The phenomenon of E- HRM deserves closer and more fundamental roots to HR activity. The E-HRM develops and b...

  2. Educating for Electronic Resources

    Science.gov (United States)

    Grogg, Jill E.

    2008-01-01

    While mission statements for various libraries and information centers necessarily vary, all librarians face "two very pressing charges: make voluminous numbers of electronic resources as visible as possible in a landscape of multiple access points and simultaneously manage all the technology, tasks, and data necessary to facilitate such…

  3. Electronic Resource Management Systems

    Directory of Open Access Journals (Sweden)

    Mark Ellingsen

    2004-10-01

    Full Text Available Computer applications which deal with electronic resource management (ERM are quite a recent development. They have grown out of the need to manage the burgeoning number of electronic resources particularly electronic journals. Typically, in the early years of e-journal acquisition, library staff provided an easy means of accessing these journals by providing an alphabetical list on a web page. Some went as far as categorising the e-journals by subject and then grouping the journals either on a single web page or by using multiple pages. It didn't take long before it was recognised that it would be more efficient to dynamically generate the pages from a database rather than to continually edit the pages manually. Of course, once the descriptive metadata for an electronic journal was held within a database the next logical step was to provide administrative forms whereby that metadata could be manipulated. This in turn led to demands for incorporating more information and more functionality into the developing application.

  4. Electronic Resource Management and Design

    Science.gov (United States)

    Abrams, Kimberly R.

    2015-01-01

    We have now reached a tipping point at which electronic resources comprise more than half of academic library budgets. Because of the increasing work associated with the ever-increasing number of e-resources, there is a trend to distribute work throughout the library even in the presence of an electronic resources department. In 2013, the author…

  5. Managing electronic resources a LITA guide

    CERN Document Server

    Weir, Ryan O

    2012-01-01

    Informative, useful, current, Managing Electronic Resources: A LITA Guide shows how to successfully manage time, resources, and relationships with vendors and staff to ensure personal, professional, and institutional success.

  6. Electronic Resources Management Project Presentation 2012

    KAUST Repository

    Ramli, Rindra M.

    2012-11-05

    This presentation describes the electronic resources management project undertaken by the KAUST library. The objectives of this project is to migrate information from MS Sharepoint to Millennium ERM module. One of the advantages of this migration is to consolidate all electronic resources into a single and centralized location. This would allow for better information sharing among library staff.

  7. Implementing CORAL: An Electronic Resource Management System

    Science.gov (United States)

    Whitfield, Sharon

    2011-01-01

    A 2010 electronic resource management survey conducted by Maria Collins of North Carolina State University and Jill E. Grogg of University of Alabama Libraries found that the top six electronic resources management priorities included workflow management, communications management, license management, statistics management, administrative…

  8. PRINCIPLES OF CONTENT FORMATION EDUCATIONAL ELECTRONIC RESOURCE

    Directory of Open Access Journals (Sweden)

    О Ю Заславская

    2017-12-01

    Full Text Available The article considers modern possibilities of information and communication technologies for the design of electronic educational resources. The conceptual basis of the open educational multimedia system is based on the modular architecture of the electronic educational resource. The content of the electronic training module can be implemented in several versions of the modules: obtaining information, practical exercises, control. The regularities in the teaching process in modern pedagogical theory are considered: general and specific, and the principles for the formation of the content of instruction at different levels are defined, based on the formulated regularities. On the basis of the analysis, the principles of the formation of the electronic educational resource are determined, taking into account the general and didactic patterns of teaching.As principles of the formation of educational material for obtaining information for the electronic educational resource, the article considers: the principle of methodological orientation, the principle of general scientific orientation, the principle of systemic nature, the principle of fundamentalization, the principle of accounting intersubject communications, the principle of minimization. The principles of the formation of the electronic training module of practical studies in the article include: the principle of systematic and dose based consistency, the principle of rational use of study time, the principle of accessibility. The principles of the formation of the module for monitoring the electronic educational resource can be: the principle of the operationalization of goals, the principle of unified identification diagnosis.

  9. Electronic Resources Management System: Recommendation Report 2017

    KAUST Repository

    Ramli, Rindra M.

    2017-05-01

    This recommendation report provides an overview of the selection process for the new Electronic Resources Management System. The library has decided to move away from Innovative Interfaces Millennium ERM module. The library reviewed 3 system as potential replacements namely: Proquest 360 Resource Manager, Ex Libris Alma and Open Source CORAL ERMS. After comparing and trialling the systems, it was decided to go for Proquest 360 Resource Manager.

  10. CHALLENGES OF ELECTRONIC INFORMATION RESOURCES IN ...

    African Journals Online (AJOL)

    This paper discusses the role of policy for proper and efficient library services in the electronic era. It points out some of the possible dangers of embarking in electronic resources without a proper focus at hand. Thus, it calls for today's librarians and policy makers to brainstorm and come up with working policies suitable to ...

  11. Library training to promote electronic resource usage

    DEFF Research Database (Denmark)

    Frandsen, Tove Faber; Tibyampansha, Dativa; Ibrahim, Glory

    2017-01-01

    Purpose: Increasing the usage of electronic resources is an issue of concern for many libraries all over the world. Several studies stress the importance of information literacy and instruction in order to increase the usage. Design/methodology/approach: The present article presents the results...... of implementing training programmes to encourage the use of the e-library. Findings: Training sessions increase the usage of library e-resources significantly; however, the effect seems to be short-lived and training sessions alone may not increase the overall long-term usage. Originality/value: The present paper...... presents a study of training sessions as means to increase awareness and usage of library e-resources. Implications for the planning of training are discussed....

  12. Library Training to Promote Electronic Resource Usage

    DEFF Research Database (Denmark)

    Frandsen, Tove Faber; Tibyampansha, Dativa; Ibrahim, Glory

    2017-01-01

    Purpose: Increasing the usage of electronic resources is an issue of concern for many libraries all over the world. Several studies stress the importance of information literacy and instruction in order to increase the usage. Design/methodology/approach: The present article presents the results...... of implementing training programmes to encourage the use of the e-library. Findings: Training sessions increase the usage of library e-resources significantly; however, the effect seems to be short-lived and training sessions alone may not increase the overall long-term usage. Originality/value: The present paper...... presents a study of training sessions as means to increase awareness and usage of library e-resources. Implications for the planning of training are discussed....

  13. Electronic resource management systems a workflow approach

    CERN Document Server

    Anderson, Elsa K

    2014-01-01

    To get to the bottom of a successful approach to Electronic Resource Management (ERM), Anderson interviewed staff at 11 institutions about their ERM implementations. Among her conclusions, presented in this issue of Library Technology Reports, is that grasping the intricacies of your workflow-analyzing each step to reveal the gaps and problems-at the beginning is crucial to selecting and implementing an ERM. Whether the system will be used to fill a gap, aggregate critical data, or replace a tedious manual process, the best solution for your library depends on factors such as your current soft

  14. 2015 Utilization of Electronic Information Resources in Ramat

    African Journals Online (AJOL)

    Utilization of Electronic Information Resources in Ramat Library, University of Maiduguri, Nigeria. 195 ... Information Impact Vol. 6 (2) 2015. Introduction. The concept of "e-resources" which stands for electronic resources has become a global phenomenon which emerged as a ... Science, Delta State University Abaraka,.

  15. Use of Electronic Resources in a Private University in Nigeria ...

    African Journals Online (AJOL)

    The study examined awareness and constraints in the use of electronic resources by lecturers and students of Ajayi Crowther University, Oyo, Nigeria. It aimed at justifying the resources expended in the provision of electronic resources in terms of awareness, patronage and factors that may be affecting awareness and use ...

  16. Electronic Resource Management System. Vernetzung von Lizenzinformationen

    Directory of Open Access Journals (Sweden)

    Michaela Selbach

    2014-12-01

    Full Text Available In den letzten zehn Jahren spielen elektronische Ressourcen im Bereich der Erwerbung eine zunehmend wichtige Rolle: Eindeutig lässt sich hier ein Wandel in den Bibliotheken (fort vom reinen Printbestand zu immer größeren E-Only-Beständen feststellen. Die stetig wachsende Menge an E-Ressourcen und deren Heterogenität stellt Bibliotheken vor die Herausforderung, die E-Ressourcen effizient zu verwalten. Nicht nur Bibliotheken, sondern auch verhandlungsführende Institutionen von Konsortial- und Allianzlizenzen benötigen ein geeignetes Instrument zur Verwaltung von Lizenzinformationen, welches den komplexen Anforderungen moderner E-Ressourcen gerecht wird. Die Deutsche Forschungsgemeinschaft (DFG unterstützt ein Projekt des Hochschulbibliothekszentrums des Landes Nordrhein-Westfalen (hbz, der Universitätsbibliothek Freiburg, der Verbundzentrale des Gemeinsamen Bibliotheksverbundes (GBV und der Universitätsbibliothek Frankfurt, in dem ein bundesweit verfügbares Electronic Ressource Managementsystem (ERMS aufgebaut werden soll. Ein solches ERMS soll auf Basis einer zentralen Knowledge Base eine einheitliche Nutzung von Daten zur Lizenzverwaltung elektronischer Ressourcen auf lokaler, regionaler und nationaler Ebene ermöglichen. Statistische Auswertungen, Rechteverwaltung für alle angeschlossenen Bibliotheken, kooperative Datenpflege sowie ein über standardisierte Schnittstellen geführter Datenaustausch stehen bei der Erarbeitung der Anforderungen ebenso im Fokus wie die Entwicklung eines Daten- und Funktionsmodells. In the last few years the importance of electronic resources in library acquisitions has increased significantly. There has been a shift from mere print holdings to both e- and print combinations and even e-only subscriptions. This shift poses a double challenge for libraries: On the one hand they have to provide their e-resource collections to library users in an appealing way, on the other hand they have to manage these

  17. Electronic human resource management: Enhancing or entrancing?

    Directory of Open Access Journals (Sweden)

    Paul Poisat

    2017-01-01

    Full Text Available Orientation: This article provides an investigation into the current level of development of the body of knowledge related to electronic human resource management (e-HRM by means of a qualitative content analysis. Several aspects of e-HRM, namely definitions of e-HRM, the theoretical perspectives around e-HRM, the role of e-HRM, the various types of e-HRM and the requirements for successful e-HRM, are examined.Research purpose: The purpose of the article was to determine the status of e-HRM and examine the studies that report on the link between e-HRM and organisational productivity.Motivation for the study: e-HRM has the capacity to improve organisational efficiency and leverage the role of human resources (HR as a strategic business partner.Main findings: The notion that the implementation of e-HRM will lead to improved organisational productivity is commonly assumed; however, empirical evidence in this regard was found to be limited.Practical/managerial implications: From the results of this investigation it is evident that more research is required to gain a greater understanding of the influence of e-HRM on organisational productivity, as well as to develop measures for assessing this influence.Contribution: This article proposes additional areas to research and measure when investigating the effectiveness of e-HRM. It provides a different lens from which to view e-HRM assessment whilst keeping it within recognised HR measurement parameters (the HR value chain. In addition, it not only provides areas for measuring e-HRM’s influence but also provides important clues as to how the measurements may be approached. 

  18. Utilization of electronic information resources by academic staff at ...

    African Journals Online (AJOL)

    The study investigated the utilization of Electronic Information resources by the academic staff of Makerere University in Uganda. It examined the academic staff awareness of the resources available, the types of resources provided by the Makerere University Library, the factors affecting resource utilization. The study was ...

  19. Electronic Resource Management: Functional Integration in Technical Services

    OpenAIRE

    Stachokas, George

    2014-01-01

    Declining usage of print materials along with increasing usage of electronic resources makes it necessary for libraries to reallocate personnel from print management to electronic resources management. Electronic resources management should be the primary focus of technical services units in the early twenty-first century. Print should no longer be treated as the default format, and the work of library staff must be reorganized and reintegrated with librarians and other professionals to refle...

  20. impact of the use of electronic resources on research output

    African Journals Online (AJOL)

    manda

    Abstract. This paper examines the impact of the use of electronic information resources on research output in the universities in Tanzania. Research for this paper was conducted in five public universities in Tanzania with varied levels of access to electronic information resources. The selection of the sample universities was ...

  1. Page 170 Use of Electronic Resources by Undergraduates in Two ...

    African Journals Online (AJOL)

    The evolution of information technology in the twentieth century has influenced students' use of information resources. Today, many students access information electronically via the Internet using desktop, laptop, palmtop and mobile phones. Electronic resources supply all the information that a library provides through ...

  2. The impact of electronic information resource use on research output

    African Journals Online (AJOL)

    This paper examines the impact of the use of electronic information resources on research output in the universities in Tanzania. Research for this paper was conducted in five public universities in Tanzania with varied levels of access to electronic information resources. The selection of the sample universities was ...

  3. Use of electronic resources by undergraduates in two selected ...

    African Journals Online (AJOL)

    The purpose of this study is to know the extent of use of electronic resources and identify the type of electronic resources used by undergraduates in universities in Nigeria. Questionnaire was used for data collection. The study population includes all undergraduate students in the faculty of engineering in Niger Delta ...

  4. The Role of the Acquisitions Librarian in Electronic Resources Management

    Science.gov (United States)

    Pomerantz, Sarah B.

    2010-01-01

    With the ongoing shift to electronic formats for library resources, acquisitions librarians, like the rest of the profession, must adapt to the rapidly changing landscape of electronic resources by keeping up with trends and mastering new skills related to digital publishing, technology, and licensing. The author sought to know what roles…

  5. Use of electronic information resources in goverment libraries

    Directory of Open Access Journals (Sweden)

    Simona Omahen

    2003-01-01

    Full Text Available The article presents the use of electronic information resources in government libraries in Slovenia. It starts with the definition of government libraries and electronic publications. On a selected sample of government libraries, the state of the usage of electronic information resources in government libraries was studied. On the basis of interviews, carried out in five government libraries, it was established that government libraries mostly do not focus on, or even think about, the use of electronic information resources. What they have and use seems self-evident to them.

  6. Electronic information resources for food toxicology.

    Science.gov (United States)

    Winter, Carl K

    2002-04-25

    This manuscript provides a brief overview of many useful Internet resources concerning food toxicology. Specific topic areas include pesticide residues, food additives, natural toxins, environmental contaminants, and food allergies; numerous links and evaluative information are provided within each topic area. Several helpful Internet resources have been identified and include government, industry, academic, and consumer sites.

  7. Electronic resources preferred by pediatric hospitalists for clinical care.

    Science.gov (United States)

    Beck, Jimmy B; Tieder, Joel S

    2015-10-01

    There is little research on pediatric hospitalists' use of evidence-based resources. The aim of this study was to determine the electronic resources that pediatric hospitalists prefer. Using a web-based survey, the authors determined hospitalists' preferred electronic resources, as well as their attitudes toward lifelong learning, practice, and experience characteristics. One hundred sixteen hospitalists completed the survey. The most preferred resource for general information, patient handouts, and treatment was UpToDate. Online search engines were ranked second for general information and patient handouts. Pediatric hospitalists tend to utilize less rigorous electronic resources such as UpToDate and Google. These results can set a platform for discussing the quality of resources that pediatric hospitalists use.

  8. Improving Electronic Resources through Holistic Budgeting

    Science.gov (United States)

    Kusik, James P.; Vargas, Mark A.

    2009-01-01

    To establish a more direct link between its collections and the educational goals of Saint Xavier University, the Byrne Memorial Library has adopted a "holistic" approach to collection development. This article examines how traditional budget practices influenced the library's selection of resources and describes how holistic collection…

  9. Electronic learning and open educational resources in the health ...

    African Journals Online (AJOL)

    Electronic learning and open educational resources in the health sciences in Ghana. ... Methods: Two e-learning materials were developed, one on the polymerase ... 95% (18) at UG report having access to a computer for learning purposes.

  10. Integrating Electronic Resources into the Library Catalog: A Collaborative Approach.

    Science.gov (United States)

    Herrera, Gail; Aldana, Lynda

    2001-01-01

    Describes a project at the University of Mississippi Libraries to catalog purchased electronic resources so that access to these resources is available only via the Web-based library catalog. Discusses collaboration between cataloging and systems personnel; and describes the MARC catalog record field that contains the information needed to locate…

  11. Utilisation of Electronic Information Resources By Lecturers in ...

    African Journals Online (AJOL)

    This study assesses the use of information resources, specifically, electronic databases by lecturers/teachers in Universities and Colleges of Education in South Western Nigeria. Information resources are central to teachers' education. It provides lecturers/teachers access to information that enhances research and ...

  12. Euler European Libraries and Electronic Resources in Mathematical Sciences

    CERN Document Server

    The Euler Project. Karlsruhe

    The European Libraries and Electronic Resources (EULER) Project in Mathematical Sciences provides the EulerService site for searching out "mathematical resources such as books, pre-prints, web-pages, abstracts, proceedings, serials, technical reports preprints) and NetLab (for Internet resources), this outstanding engine is capable of simple, full, and refined searches. It also offers a browse option, which responds to entries in the author, keyword, and title fields. Further information about the Project is provided at the EULER homepage.

  13. Building an electronic resource collection a practical guide

    CERN Document Server

    Lee, Stuart D

    2004-01-01

    This practical book guides information professionals step-by-step through building and managing an electronic resource collection. It outlines the range of electronic products currently available in abstracting and indexing, bibliographic, and other services and then describes how to effectively select, evaluate and purchase them.

  14. CDC and ATSDR electronic information resources for health officers.

    Science.gov (United States)

    Friede, A; O'Carroll, P W

    1996-12-01

    This article catalogs some of the Centers for Disease Control and Prevention's (CDC) more important information resource offerings, which make public health information accessible via computer and automated telephone systems and on electronic media (diskette and CD-ROM). We review mechanisms for (1) finding and retrieving CDC reports, (2) querying CDC's numeric data files, (3) transmitting surveillance and other data files to CDC, (4) exchanging electronic mail with CDC staff, and (5) disseminating state and local public health information and data by using CDC tools. Each resource is followed with a section on how to obtain access to these resources.

  15. Organizational matters of competition in electronic educational resources

    Directory of Open Access Journals (Sweden)

    Ирина Карловна Войтович

    2015-12-01

    Full Text Available The article examines the experience of the Udmurt State University in conducting competitions of educational publications and electronic resources. The purpose of such competitions is to provide methodological support to educational process. The main focus is on competition of electronic educational resources. The technology of such contests is discussed through detailed analysis of the main stages of the contest. It is noted that the main task of the preparatory stage of the competition is related to the development of regulations on competition and the definition of criteria for selection of the submitted works. The paper also proposes a system of evaluation criteria of electronic educational resources developed by members of the contest organizing committee and jury members. The article emphasizes the importance of not only the preparatory stages of the competition, but also measures for its completion, aimed at training teachers create quality e-learning resources.

  16. USE OF VIDEO IN MULTIMEDIA ELECTRONIC EDUCATIONAL RESOURCES

    Directory of Open Access Journals (Sweden)

    Svitlana Denisenko

    2015-10-01

    Full Text Available The widespread introduction of electronic educational resources in the educational process requires the development of a scientific basis for all aspects related to their creation and use. These modern means are designed not just to convey to learners the required course material, but also to create conditions for its most effective study. This is possible in conditions of reasonable approach to the presentation of educational material on the screen. The article is devoted to consideration of the problem of presenting educational material in electronic educational resources. Visuals are powerful didactic tool that enhances the perception and understanding of educational information. Particular attention is paid to the use of such a powerful medium like video. Investigated the role and importance of video in the learning process, their educational opportunities and benefits. Shows types of video and their use in electronic educational resources. Grounded requirements for training videos. The recommendations are given on the use of video in combination with other media in electronic educational resources. Adduced the example a real electronic multimedia educational resource and shows the possibility of using video.

  17. Access to electronic resources by visually impaired people

    Directory of Open Access Journals (Sweden)

    Jenny Craven

    2003-01-01

    Full Text Available Research into access to electronic resources by visually impaired people undertaken by the Centre for Research in Library and Information Management has not only explored the accessibility of websites and levels of awareness in providing websites that adhere to design for all principles, but has sought to enhance understanding of information seeking behaviour of blind and visually impaired people when using digital resources.

  18. Practical guide to electronic resources in the humanities

    CERN Document Server

    Dubnjakovic, Ana

    2010-01-01

    From full-text article databases to digitized collections of primary source materials, newly emerging electronic resources have radically impacted how research in the humanities is conducted and discovered. This book, covering high-quality, up-to-date electronic resources for the humanities, is an easy-to-use annotated guide for the librarian, student, and scholar alike. It covers online databases, indexes, archives, and many other critical tools in key humanities disciplines including philosophy, religion, languages and literature, and performing and visual arts. Succinct overviews of key eme

  19. Electronic Commerce Resource Centers. An Industry--University Partnership.

    Science.gov (United States)

    Gulledge, Thomas R.; Sommer, Rainer; Tarimcilar, M. Murat

    1999-01-01

    Electronic Commerce Resource Centers focus on transferring emerging technologies to small businesses through university/industry partnerships. Successful implementation hinges on a strategic operating plan, creation of measurable value for customers, investment in customer-targeted training, and measurement of performance outputs. (SK)

  20. Providing Access to Electronic Information Resources in Further Education

    Science.gov (United States)

    Banwell, Linda; Ray, Kathryn; Coulson, Graham; Urquhart, Christine; Lonsdale, Ray; Armstrong, Chris; Thomas, Rhian; Spink, Sin; Yeoman, Alison; Fenton, Roger; Rowley, Jennifer

    2004-01-01

    This article aims to provide a baseline for future studies on the provision and support for the use of digital or electronic information services (EIS) in further education. The analysis presented is based on a multi-level model of access, which encompasses access to and availability of information and communication technology (ICT) resources,…

  1. use of electronic resources by graduate students of the department ...

    African Journals Online (AJOL)

    the media (internet, cyber café, Phone and University cafe). 2. There is no significant difference in the level of use of electronic resources between male and female postgraduate students of the department of educational technology and library science in the University of Uyo. 3. There is no significant difference in the of.

  2. Printed And Electronic Resources Utilization By Agricultural Science ...

    African Journals Online (AJOL)

    This paper examines the use of printed and electronic resources by agricultural science students in three Nigerian universities. A two-part questionnaire was designed to elicit necessary information from the respondents selected for the study. One thousand three hundred (1300) respondents from faculties of Agriculture in ...

  3. Adoption and use of electronic information resources by medical ...

    African Journals Online (AJOL)

    This study investigated the adoption and use of electronic information resources by medical science students of the University of Benin. The descriptive survey research design was adopted for the study and 390 students provided the data. Data collected were analysed with descriptive Statistics(Simple percentage and ...

  4. Electronic resources access and usage among the postgraduates of ...

    African Journals Online (AJOL)

    This study investigated electronic resources access and usage among the postgraduates of a Nigerian University of Technology. The Taro Yamane's sample size formula was used to determine sample size of 276 respondents from the total population of the study and systematic random sampling was used to select the ...

  5. Electronic information resource sharing among university libraries in ...

    African Journals Online (AJOL)

    The study explored the state of electronic information resource sharing among university libraries in Southern part of Nigeria, highlighting the prospects and the challenges. The study was an empirical research which adopted the descriptive survey as the design. The questionnaire was used to collect data from the ...

  6. Access to electronic information resources by students of federal ...

    African Journals Online (AJOL)

    The paper discusses access to electronic information resources by students of Federal Colleges of Education in Eha-Amufu and Umunze. Descriptive survey design was used to investigate sample of 526 students. Sampling technique used was a Multi sampling technique. Data for the study were generated using ...

  7. ANALYTICAL REVIEW OF ELECTRONIC RESOURCES FOR THE STUDY OF LATIN

    Directory of Open Access Journals (Sweden)

    Olena Yu. Balalaieva

    2014-04-01

    Full Text Available The article investigates the current state of development of e-learning content in the Latin language. It is noted that the introduction of ICT in the educational space has expanded the possibility of studying Latin, opened access to digital libraries resources, made it possible to use scientific and educational potential and teaching Latin best practices of world's leading universities. A review of foreign and Ukrainian information resources and electronic editions for the study of Latin is given. Much attention was paid to the didactic potential of local and online multimedia courses of Latin, electronic textbooks, workbooks of interactive tests and exercises, various dictionaries and software translators, databases and digital libraries. Based on analysis of the world market of educational services and products the main trends in the development of information resources and electronic books are examined. It was found that multimedia courses with interactive exercises or workbooks with interactive tests, online dictionaries and translators are the most widely represented and demanded. The noticeable lagging of Ukrainian education and computer linguistics in quantitative and qualitative measures in this industry is established. The obvious drawback of existing Ukrainian resources and electronic editions for the study of Latin is their noninteractive nature. The prospects of e-learning content in Latin in Ukraine are outlined.

  8. Use of Internet and Electronic Resources amongst Postgraduate ...

    African Journals Online (AJOL)

    A Nigerian private university is newly venturing into p ostgraduate study programs and has an enrolled postgraduate student population of about a hundred. This study evaluates the postgraduate students' use of library; their information format preference, internet access and electronic resources used in their various ...

  9. The impact of electronic information resource use on research output

    African Journals Online (AJOL)

    The selection of the sample universities was purposive. ... This was demonstrated in the increased number of proposals prepared, submitted and funded, research reports submitted, journal articles published and chapters in books and books published with increased access to and use of electronic information resources.

  10. Technical Communicator: A New Model for the Electronic Resources Librarian?

    Science.gov (United States)

    Hulseberg, Anna

    2016-01-01

    This article explores whether technical communicator is a useful model for electronic resources (ER) librarians. The fields of ER librarianship and technical communication (TC) originated and continue to develop in relation to evolving technologies. A review of the literature reveals four common themes for ER librarianship and TC. While the…

  11. Gender Analysis Of Electronic Information Resource Use: The Case ...

    African Journals Online (AJOL)

    This article is based on an empirical study that examined the association between gender and the use of electronic information resources among postgraduate students at the University of Dar es salaam, Tanzania. The study was conducted in December 2005 and integrated both qualitative and quantitative research ...

  12. Users satisfaction with electronic information resources and services ...

    African Journals Online (AJOL)

    Users satisfaction with electronic information resources and services in A.B.U & UNIBEN MTN Net Libraries. ... Lastly, management of the MTN Net Libraries should conduct user studies annually in order to have feedback from users on how well the library is meeting their information needs. The results of the survey should ...

  13. Skills and training needs for use of electronic information resources ...

    African Journals Online (AJOL)

    The article reports on the findings regarding students' knowledge, skill and training needs in using Electronic Information Resources (EIRs). Data was collected using a questionnaire-based survey administered to 1123 undergraduate students. Probability sampling was used to sample students across the four universities, ...

  14. Think Locally: A Prudent Approach to Electronic Resource Management Systems

    Science.gov (United States)

    Gustafson-Sundell, Nat

    2011-01-01

    A few articles have drawn some amount of attention specifically to the local causes of the success or failure of electronic resource management system (ERMS) implementations. In fact, it seems clear that local conditions will largely determine whether any given ERMS implementation will succeed or fail. This statement might seem obvious, but the…

  15. Evaluating the appropriateness of electronic information resources for learning.

    Science.gov (United States)

    Saparova, Dinara; Nolan, Nathanial S

    2016-01-01

    Current US medical students have begun to rely on electronic information repositories-such as UpToDate, AccessMedicine, and Wikipedia-for their pre-clerkship medical education. However, it is unclear whether these resources are appropriate for this level of learning due to factors involving information quality, level of evidence, and the requisite knowledgebase. This study evaluated appropriateness of electronic information resources from a novel perspective: amount of mental effort learners invest in interactions with these resources and effects of the experienced mental effort on learning. Eighteen first-year medical students read about three unstudied diseases in the above-mentioned resources (a total of fifty-four observations). Their eye movement characteristics (i.e., fixation duration, fixation count, visit duration, and task-evoked pupillary response) were recorded and used as psychophysiological indicators of the experienced mental effort. Post reading, students' learning was assessed with multiple-choice tests. Eye metrics and test results constituted quantitative data analyzed according to the repeated Latin square design. Students' perceptions of interacting with the information resources were also collected. Participants' feedback during semi-structured interviews constituted qualitative data and was reviewed, transcribed, and open coded for emergent themes. Compared to AccessMedicine and Wikipedia, UpToDate was associated with significantly higher values of eye metrics, suggesting learners experienced higher mental effort. No statistically significant difference between the amount of mental effort and learning outcomes was found. More so, descriptive statistical analysis of the knowledge test scores suggested similar levels of learning regardless of the information resource used. Judging by the learning outcomes, all three information resources were found appropriate for learning. UpToDate, however, when used alone, may be less appropriate for first

  16. E-Resources Management: How We Positioned Our Organization to Implement an Electronic Resources Management System

    Science.gov (United States)

    White, Marilyn; Sanders, Susan

    2009-01-01

    The Information Services Division (ISD) of the National Institute of Standards and Technology (NIST) positioned itself to successfully implement an electronic resources management system. This article highlights the ISD's unique ability to "team" across the organization to realize a common goal, develop leadership qualities in support of…

  17. MODEL OF AN ELECTRONIC EDUCATIONAL RESOURCE OF NEW GENERATION

    Directory of Open Access Journals (Sweden)

    Anatoliy V. Loban

    2016-01-01

    Full Text Available The mathematical structure of the modular architecture of an electronic educational resource (EER of new generation, which allows to decompose the process of studying the subjects of the course at a hierarchically ordered set of data (knowledge and procedures for manipulating them, to determine the roles of participants of process of training of and technology the development and use of EOR in the study procrate.

  18. Journals, Data and Abstracts Make an Integrated Electronic Resource

    Science.gov (United States)

    Boyce, P.

    1996-12-01

    Astronomy now has an integrated, Web-based information resource for research papers, data and bibliographic information. The major scholarly research journals, a comprehensive abstract service and the astronomical data centers are now linked together to provide an information resource which is not available to most other scientific disciplines. As of January, 1997, the Astrophysical Journal joins the ApJ Letters on the Web. Astronomy and Astrophysics Supplements now has a page image version. Elsevier's electronic journal New Astronomy has recently made its appearance. Over forty percent of the new peer-reviewed, astronomical literature is now available electronically. The main Astronomy and Astrophysics journal, the Astronomical Journal and others will be available by 1998, at which point ninety percent of the literature will be available electronically, a figure not approached by any other scientific discipline. With so many different sources, one of the challenges has been to integrate the on-line, peer-reviewed literature into a resource which serves the astronomical community in a unified and coherent manner. Following the lead of the AAS, the major publishers have chosen to rely upon the NASA-supported Astrophysics Data System (ADS) and the astronomical data centers to provide the means by which the various separate journals can interoperate. The data centers and the ADS have developed unique identification codes for journal articles. By adopting the existing standard "bibcodes" and integrating them into their WWW links, each of the major astronomical journals are able to link to the abstracts of most of the referenced articles. Since the ADS also serves as an on-line repository for page images of the past twenty years of the major astronomical journals, the full text of many of the referenced articles are available, too. The articles in the ADS have recently been linked through their references, both forward and backward in time. With the "bibcode" providing

  19. Evaluating increased resource use in fibromyalgia using electronic health records.

    Science.gov (United States)

    Margolis, Jay M; Masters, Elizabeth T; Cappelleri, Joseph C; Smith, David M; Faulkner, Steven

    2016-01-01

    The management of fibromyalgia (FM), a chronic musculoskeletal disease, remains challenging, and patients with FM are often characterized by high health care resource utilization. This study sought to explore potential drivers of all-cause health care resource utilization and other factors associated with high resource use, using a large electronic health records (EHR) database to explore data from patients diagnosed with FM. This was a retrospective analysis of de-identified EHR data from the Humedica database. Adults (≥18 years) with FM were identified based on ≥2 International Classification of Diseases, Ninth Revision codes for FM (729.1) ≥30 days apart between January 1, 2008 and December 31, 2012 and were required to have evidence of ≥12 months continuous care pre- and post-index; first FM diagnosis was the index event; 12-month pre- and post-index reporting periods. Multivariable analysis evaluated relationships between variables and resource utilization. Patients were predominantly female (81.4%), Caucasian (87.7%), with a mean (standard deviation) age of 54.4 (14.8) years. The highest health care resource utilization was observed for the categories of "medication orders" and "physician office visits," with 12-month post-index means of 21.2 (21.5) drug orders/patient and 15.1 (18.1) office visits/patient; the latter accounted for 73.3% of all health care visits. Opioids were the most common prescription medication, 44.3% of all patients. The chance of high resource use was significantly increased ( P FM patients.

  20. Analysis of Human Resources Management Strategy in China Electronic Commerce Enterprises

    Science.gov (United States)

    Shao, Fang

    The paper discussed electronic-commerce's influence on enterprise human resources management, proposed and proved the human resources management strategy which electronic commerce enterprise should adopt from recruitment strategy to training strategy, keeping talent strategy and other ways.

  1. COLLECTIONS OF ELECTRONIC INFORMATION RESOURCES AND THEIR METADESCRIPTIONS AS COMPONENTS OF SCIENTIFIC ELECTRONIC LIBRARY

    Directory of Open Access Journals (Sweden)

    Zoya V. Savchenko

    2011-02-01

    Full Text Available The article presents the results of scientific research components of digital libraries, the main ones being the collection of electronic scientific information resources. An important specific characteristics of collections of scientific information resources, resources of their formation, structure collections, methods of their organization, technology creation, support and use of scientific collections, the role and function of metadata in collections and metadata management technology are represented. On the stage of planning and introduction of scientific e-libraries there can be used results of researches presented in the article, namely: chart of forming of collections of scientific informative resources; stages of planning and development of metadescriptions, and similarly the use of standard the Dublin kernel, creation of metadescriptions.

  2. Electronic Resources and Mission Creep: Reorganizing the Library for the Twenty-First Century

    Science.gov (United States)

    Stachokas, George

    2009-01-01

    The position of electronic resources librarian was created to serve as a specialist in the negotiation of license agreements for electronic resources, but mission creep has added more functions to the routine work of electronic resources such as cataloging, gathering information for collection development, and technical support. As electronic…

  3. Electronic Document Management: A Human Resource Management Case Study

    Directory of Open Access Journals (Sweden)

    Thomas Groenewald

    2004-11-01

    Full Text Available This case study serve as exemplar regarding what can go wrong with the implementation of an electronic document management system. Knowledge agility and knowledge as capital, is outlined against the backdrop of the information society and knowledge economy. The importance of electronic document management and control is sketched thereafter. The literature review is concluded with the impact of human resource management on knowledge agility, which includes references to the learning organisation and complexity theory. The intervention methodology, comprising three phases, follows next. The results of the three phases are presented thereafter. Partial success has been achieved with improving the human efficacy of electronic document management, however the client opted to discontinue the system in use. Opsomming Die gevalle studie dien as voorbeeld van wat kan verkeerd loop met die implementering van ’n elektroniese dokumentbestuur sisteem. Teen die agtergrond van die inligtingsgemeenskap en kennishuishouding word kennissoepelheid en kennis as kapitaal bespreek. Die literatuurstudie word afgesluit met die inpak van menslikehulpbronbestuur op kennissoepelheid, wat ook die verwysings na die leerorganisasie en kompleksietydsteorie insluit. Die metodologie van die intervensie, wat uit drie fases bestaan, volg daarna. Die resultate van die drie fases word vervolgens aangebied. Slegs gedeelte welslae is behaal met die verbetering van die menslike doeltreffendheid ten opsigte van elektroniese dokumentbestuur. Die klient besluit egter om nie voort te gaan om die huidige sisteem te gebruik nie.

  4. Electronic Safety Resource Tools -- Supporting Hydrogen and Fuel Cell Commercialization

    Energy Technology Data Exchange (ETDEWEB)

    Barilo, Nick F.

    2014-09-29

    The Pacific Northwest National Laboratory (PNNL) Hydrogen Safety Program conducted a planning session in Los Angeles, CA on April 1, 2014 to consider what electronic safety tools would benefit the next phase of hydrogen and fuel cell commercialization. A diverse, 20-person team led by an experienced facilitator considered the question as it applied to the eight most relevant user groups. The results and subsequent evaluation activities revealed several possible resource tools that could greatly benefit users. The tool identified as having the greatest potential for impact is a hydrogen safety portal, which can be the central location for integrating and disseminating safety information (including most of the tools identified in this report). Such a tool can provide credible and reliable information from a trustworthy source. Other impactful tools identified include a codes and standards wizard to guide users through a series of questions relating to application and specific features of the requirements; a scenario-based virtual reality training for first responders; peer networking tools to bring users from focused groups together to discuss and collaborate on hydrogen safety issues; and a focused tool for training inspectors. Table ES.1 provides results of the planning session, including proposed new tools and changes to existing tools.

  5. Resources

    Science.gov (United States)

    ... disease - resources Hemophilia - resources Herpes - resources Incest - resources Incontinence - resources Infertility - resources Interstitial cystitis - resources Kidney disease - resources Leukemia - resources Liver disease - resources Loss ...

  6. Controlling user access to electronic resources without password

    Science.gov (United States)

    Smith, Fred Hewitt

    2015-06-16

    Described herein are devices and techniques for remotely controlling user access to a restricted computer resource. The process includes pre-determining an association of the restricted computer resource and computer-resource-proximal environmental information. Indicia of user-proximal environmental information are received from a user requesting access to the restricted computer resource. Received indicia of user-proximal environmental information are compared to associated computer-resource-proximal environmental information. User access to the restricted computer resource is selectively granted responsive to a favorable comparison in which the user-proximal environmental information is sufficiently similar to the computer-resource proximal environmental information. In at least some embodiments, the process further includes comparing user-supplied biometric measure and comparing it with a predetermined association of at least one biometric measure of an authorized user. Access to the restricted computer resource is granted in response to a favorable comparison.

  7. Utilization of electronic information resources in Ramat Library ...

    African Journals Online (AJOL)

    Data was analysed using descriptive statistics of percentage and frequency counts. ... available in the Ramat Library for the purpose of enhancing learning outcome. Keywords: e-Resources, information resources, utilization, Ramat library ...

  8. The Internet School of Medicine: use of electronic resources by medical trainees and the reliability of those resources.

    Science.gov (United States)

    Egle, Jonathan P; Smeenge, David M; Kassem, Kamal M; Mittal, Vijay K

    2015-01-01

    Electronic sources of medical information are plentiful, and numerous studies have demonstrated the use of the Internet by patients and the variable reliability of these sources. Studies have investigated neither the use of web-based resources by residents, nor the reliability of the information available on these websites. A web-based survey was distributed to surgical residents in Michigan and third- and fourth-year medical students at an American allopathic and osteopathic medical school and a Caribbean allopathic school regarding their preferred sources of medical information in various situations. A set of 254 queries simulating those faced by medical trainees on rounds, on a written examination, or during patient care was developed. The top 5 electronic resources cited by the trainees were evaluated for their ability to answer these questions accurately, using standard textbooks as the point of reference. The respondents reported a wide variety of overall preferred resources. Most of the 73 responding medical trainees favored textbooks or board review books for prolonged studying, but electronic resources are frequently used for quick studying, clinical decision-making questions, and medication queries. The most commonly used electronic resources were UpToDate, Google, Medscape, Wikipedia, and Epocrates. UpToDate and Epocrates had the highest percentage of correct answers (47%) and Wikipedia had the lowest (26%). Epocrates also had the highest percentage of wrong answers (30%), whereas Google had the lowest percentage (18%). All resources had a significant number of questions that they were unable to answer. Though hardcopy books have not been completely replaced by electronic resources, more than half of medical students and nearly half of residents prefer web-based sources of information. For quick questions and studying, both groups prefer Internet sources. However, the most commonly used electronic resources fail to answer clinical queries more than half

  9. Bridging the Two Cultures: A Collaborative Approach to Managing Electronic Resources.

    Science.gov (United States)

    Dupuis, John; Ryan, Patti

    2002-01-01

    Highlights an example of cross-discipline collaboration in an academic library and describes a collaborative approach to managing electronic resources that is used at York University (Canada). Explains a model in which a science librarian and a humanities/social science librarian work together to manage electronic resources. (Author/LRW)

  10. Checklist Manifesto for Electronic Resources: Getting Ready for the Fiscal Year and Beyond

    Science.gov (United States)

    England, Lenore; Fu, Li; Miller, Stephen

    2011-01-01

    Organization of electronic resources workflow is critical in the increasingly complicated and complex world of library management. A simple organizational tool that can be readily applied to electronic resources management (ERM) is the use of checklists. Based on the principles discussed in The Checklist Manifesto: How to Get Things Right, the…

  11. Developing Humanities Collections in the Digital Age: Exploring Humanities Faculty Engagement with Electronic and Print Resources

    Science.gov (United States)

    Kachaluba, Sarah Buck; Brady, Jessica Evans; Critten, Jessica

    2014-01-01

    This article is based on quantitative and qualitative research examining humanities scholars' understandings of the advantages and disadvantages of print versus electronic information resources. It explores how humanities' faculty members at Florida State University (FSU) use print and electronic resources, as well as how they perceive these…

  12. Application of the electronic educational resources in the higher educational institution

    Directory of Open Access Journals (Sweden)

    Александр Петрович Колошеин

    2014-12-01

    Full Text Available In article approaches to effective application of electronic educational resources are described. The analysis of methods and forms of education in higher education institution is carried out, the principles of application of the electronic educational resources, adequate to used methods and forms of education are established.

  13. Application of the electronic educational resources in the higher educational institution

    OpenAIRE

    Александр Петрович Колошеин

    2014-01-01

    In article approaches to effective application of electronic educational resources are described. The analysis of methods and forms of education in higher education institution is carried out, the principles of application of the electronic educational resources, adequate to used methods and forms of education are established.

  14. Electronic resource management practical perspectives in a new technical services model

    CERN Document Server

    Elguindi, Anne

    2012-01-01

    A significant shift is taking place in libraries, with the purchase of e-resources accounting for the bulk of materials spending. Electronic Resource Management makes the case that technical services workflows need to make a corresponding shift toward e-centric models and highlights the increasing variety of e-formats that are forcing new developments in the field.Six chapters cover key topics, including: technical services models, both past and emerging; staffing and workflow in electronic resource management; implementation and transformation of electronic resource management systems; the ro

  15. Use of Internet and Electronic Resources amongst Postgraduate ...

    African Journals Online (AJOL)

    Findings indicate that the study group has regular access to the internet , and preferred using free online resources from Google and Wikipedia to institutionally subscribed academic online resources in databases such as HINARI, EBSCO Host, Questia , JSTOR and High Beam.This shows that technology alone cannot help ...

  16. Strategic Planning for Electronic Resources Management: A Case Study at Gustavus Adolphus College

    Science.gov (United States)

    Hulseberg, Anna; Monson, Sarah

    2009-01-01

    Electronic resources, the tools we use to manage them, and the needs and expectations of our users are constantly evolving; at the same time, the roles, responsibilities, and workflow of the library staff who manage e-resources are also in flux. Recognizing a need to be more intentional and proactive about how we manage e-resources, the…

  17. EWWW!: Electronic Resources in the Twenty-First Century

    OpenAIRE

    Ogier, Andrea; Brown, Ladd; Bailey, Annette; Stovall, Connie

    2013-01-01

    Initiating necessary change in a modern library environment is quite a difficult task when faced with constantly-evolving technology, limited resources, and low budgets. This paper discusses Virginia Tech’s approach to successful e-resource management when faced with a multitude of challenges. The long-term goal is the development of a proactive information delivery eco-system that will allow staff to anticipate the information and data needs of a single user or user population based on previ...

  18. Controlling user access to electronic resources without password

    Energy Technology Data Exchange (ETDEWEB)

    Smith, Fred Hewitt

    2017-08-22

    Described herein are devices and techniques for remotely controlling user access to a restricted computer resource. The process includes obtaining an image from a communication device of a user. An individual and a landmark are identified within the image. Determinations are made that the individual is the user and that the landmark is a predetermined landmark. Access to a restricted computing resource is granted based on the determining that the individual is the user and that the landmark is the predetermined landmark. Other embodiments are disclosed.

  19. Challenges associated with cataloguing of electronic resources in ...

    African Journals Online (AJOL)

    The aim of the paper is to identify challenges associated with the cataloguing of e resources in some selected university libraries in south –south Nigeria. The descriptive survey design involving the use of questionnaire as the research instrument was adopted. The population comprised of cataloguers in five selected ...

  20. impact of the use of electronic resources on research output

    African Journals Online (AJOL)

    manda

    document delivery since 2000. License to access these resources has been country-wide for most databases. PERI project also includes a training component on ... Sciences (MUHAS). The final sample comprised 222 members of teaching and research staff, selected using purposive and convenience techniques. Findings ...

  1. Trichinella in arctic, subarctic and temperate regions

    DEFF Research Database (Denmark)

    Kapel, C. M O

    1997-01-01

    and the human activity are all very important interacting factors affecting epidemiology. In Greenland, where only sylvatic trichinellosis is present, the high prevalence in wildlife appears closely connected with polar bear hunting. In the Scandinavian countries, the prevalence of both sylvatic and domestic......The transmission and occurrence of Trichinella spp according to the zoogeography of different climatic conditions, socioeconomy and human activity are discussed. Comparing arctic, subarctic and temperate regions, it appears that the species of Trichinella present, the composition of the fauna...... populations may have epidemiological importance in relation to the recent changes in production and infrastructure in these former Soviet states....

  2. Recent changes in aquatic biota in subarctic Fennoscandia - the role of global and local environmental variables

    Science.gov (United States)

    Weckström, Jan; Leppänen, Jaakko; Sorvari, Sanna; Kaukolehto, Marjut; Weckström, Kaarina; Korhola, Atte

    2013-04-01

    The Arctic, representing a fifth of the earth's surface, is highly sensitive to the predicted future warming and it has indeed been warming up faster than most other regions. This makes the region critically important and highlights the need to investigate the earliest signals of global warming and its impacts on the arctic and subarctic aquatic ecosystems and their biota. It has been demonstrated that many Arctic freshwater ecosystems have already experienced dramatic and unpreceded regime shifts during the last ca. 150 years, primarily driven by climate warming. However, despite the indisputable impact of climate-related variables on freshwater ecosystems other, especially local-scale catchment related variables (e.g. geology, vegetation, human activities) may override the climate signal and become the primary factor in shaping the structure of aquatic ecosystems. Although many studies have contributed to an improved understanding of limnological and hydrobiological features of Artic and subarctic lakes, much information is still needed especially on the interaction between the biotic and abiotic components, i.e. on factors controlling the food web dynamics in these sensitive aquatic ecosystems. This is of special importance as these lakes are of great value in water storage, flood prevention, and maintenance of biodiversity, in addition to which they are vital resources for settlement patterns, food production, recreation, and tourism. In this study we compare the pre-industrial sediment assemblages of primary producers (diatoms and Pediastrum) and primary consumers (cladoceran and chironomids) with their modern assemblages (a top-bottom approach) from 50 subarctic Fennoscandian lakes. We will evaluate the recent regional pattern of changes in aquatic assemblages, and assess how coherent the lakes' responses are across the subarctic area. Moreover, the impact of global (e.g. climate, precipitation) and local (e.g. lake and its catchment characteristics) scale

  3. MODELING OF QUALITY MANAGEMENT SYSTEM FOR ELECTRONIC LEARNING RESOURCES: THE INTEGRATED AND DIFFERENTIATED APPROACHES

    Directory of Open Access Journals (Sweden)

    H. M. Kravtsov

    2012-03-01

    Full Text Available Abstract. Results on modeling of quality management system of electronic information resources on the basis of the analysis of its elements functioning with use of the integrated and differentiated approaches are presented. Application of such model is illustrated on an example of calculation and optimization of parameters of a quality management system at the organization of the co-ordinated work of services of monitoring, an estimation of quality and support of electronic learning resources.

  4. A Study on Developing Evaluation Criteria for Electronic Resources in Evaluation Indicators of Libraries

    Science.gov (United States)

    Noh, Younghee

    2010-01-01

    This study aimed to improve the current state of electronic resource evaluation in libraries. While the use of Web DB, e-book, e-journal, and other e-resources such as CD-ROM, DVD, and micro materials is increasing in libraries, their use is not comprehensively factored into the general evaluation of libraries and may diminish the reliability of…

  5. An Evaluation of Electronic Product Design Education Using Hypermedia-Resourced Learning Environments

    Science.gov (United States)

    Page, Tom; Thorsteinsson, Gisli

    2006-01-01

    The work outlined here provides a comprehensive report and formative observations of the development and implementation of hypermedia resources for learning and teaching used in conjunction with a managed learning environment (MLE). These resources are used to enhance teaching and learning of an electronics module in product design at final year…

  6. Video Killed the Radio Star: Language Students' Use of Electronic Resources-Reading or Viewing?

    Science.gov (United States)

    Kiliçkaya, Ferit

    2016-01-01

    The current study aimed to investigate language students' use of print and electronic resources for their research papers required in research techniques class, focusing on which reading strategies they used while reading these resources. The participants of the study were 90 sophomore students enrolled in the research techniques class offered at…

  7. Problems and future of electronic textbooks and electronic educational resources in technical college

    OpenAIRE

    Kulikov Dmitry

    2016-01-01

    This article describes the problems and prospects of introduction of electronic textbooks in the educational space of technical colleges. Practical recommendations for the maintenance, monitoring, organization and development of electronic textbooks projects.

  8. Tolerance of an expanding subarctic shrub, Betula glandulosa, to simulated caribou browsing.

    Directory of Open Access Journals (Sweden)

    Emilie Champagne

    Full Text Available Densification of the shrub layer has been reported in many subarctic regions, raising questions about the implication for large herbivores and their resources. Shrubs can tolerate browsing and their level of tolerance could be affected by browsing and soils productivity, eventually modifying resource availability for the caribou. Our objective was to assess the compensatory growth potential of a subarctic shrub, Betula glandulosa Michx., in relation with caribou browsing and nutriment availability for the plants. We used a simulated browsing (0, 25 and 75% of available shoots and nitrogen-fertilisation (0 and 10 g m(-2 experiment to test two main hypotheses linking tolerance to resource availability, the Compensatory Continuum Hypothesis and the Growth Rate Hypothesis as well as the predictions from the Limiting Resource Model. We seek to explicitly integrate the relative browsing pressure in our predictions since the amount of tissues removed could affect the capacity of long-lived plants to compensate. Birches fully compensated for moderate browsing with an overall leaf biomass similar to unbrowsed birches but undercompensated under heavy browsing pressure. The main mechanism explaining compensation appears to be the conversion of short shoots into long shoots. The leaf area increased under heavy browsing pressure but only led to undercompensation. Fertilisation for two consecutive years did not influence the response of birch, thus we conclude that our results support the LRM hypothesis of equal tolerance under both high and low nitrogen availability. Our results highlight that the potential for compensatory growth in dwarf birch is surpassed under heavy browsing pressure independently of the fertilisation regime. In the context of the worldwide decline in caribou herds, the reduction in browsing pressure could act synergistically with global climate change to promote the current shrub expansion reported in subarctic regions.

  9. Tolerance of an Expanding Subarctic Shrub, Betula glandulosa, to Simulated Caribou Browsing

    Science.gov (United States)

    Champagne, Emilie; Tremblay, Jean-Pierre; Côté, Steeve D.

    2012-01-01

    Densification of the shrub layer has been reported in many subarctic regions, raising questions about the implication for large herbivores and their resources. Shrubs can tolerate browsing and their level of tolerance could be affected by browsing and soils productivity, eventually modifying resource availability for the caribou. Our objective was to assess the compensatory growth potential of a subarctic shrub, Betula glandulosa Michx., in relation with caribou browsing and nutriment availability for the plants. We used a simulated browsing (0, 25 and 75% of available shoots) and nitrogen-fertilisation (0 and 10 g m−2) experiment to test two main hypotheses linking tolerance to resource availability, the Compensatory Continuum Hypothesis and the Growth Rate Hypothesis as well as the predictions from the Limiting Resource Model. We seek to explicitly integrate the relative browsing pressure in our predictions since the amount of tissues removed could affect the capacity of long-lived plants to compensate. Birches fully compensated for moderate browsing with an overall leaf biomass similar to unbrowsed birches but undercompensated under heavy browsing pressure. The main mechanism explaining compensation appears to be the conversion of short shoots into long shoots. The leaf area increased under heavy browsing pressure but only led to undercompensation. Fertilisation for two consecutive years did not influence the response of birch, thus we conclude that our results support the LRM hypothesis of equal tolerance under both high and low nitrogen availability. Our results highlight that the potential for compensatory growth in dwarf birch is surpassed under heavy browsing pressure independently of the fertilisation regime. In the context of the worldwide decline in caribou herds, the reduction in browsing pressure could act synergistically with global climate change to promote the current shrub expansion reported in subarctic regions. PMID:23272191

  10. Electronic information resource use: implications for teaching and library staff

    Directory of Open Access Journals (Sweden)

    Roger Ottewill

    1997-12-01

    Full Text Available Within institutions of higher education, teaching staff and library-based information specialists have tended to occupy separate worlds. Although there has been some contact, in the main this has been partial and intermittent. For first-year students, one consequence of this state of affairs has been the absence of a systematic and co-ordinated strategy for enabling them to acquire, practise and develop information-gathering skills. Teaching staff have seen their role in this respect mainly in terms of issuing students with reading lists containing a mix of books and journal articles, and underlying this approach is the expectation that information specialists will be on hand to provide whatever additional help is needed to access these resources, for example through the provision of introductory talks and one-to-one support sessions. Relatively few teaching staff have incorporated library exercises into their teaching and assessment, or adopted a more creative approach to information gathering by students, such as helping them use bibliographic and other aids to prepare personalized reading lists. Consequently, when students have been required to do this at later stages of their studies, especially in the context of preparing a dissertation, they have not been adequately prepared, and often find it extremely difficult to access and evaluate information resources effectively.

  11. Electronic Information Resources in Undergraduate Education: An Exploratory Study of Opportunities for Student Learning and Independence.

    Science.gov (United States)

    McDowell, Liz

    2002-01-01

    This qualitative interview-based study examines lecturer perspectives on the roles of electronic information resources in undergraduate education. Highlights include electronic academic libraries; changes toward more constructivist approaches to learning; information quality on the Web; plagiarism; information use; information literacy; and…

  12. Where Do Electronic Books Fit in the College Research Arsenal of Resources?

    Science.gov (United States)

    Barbier, Patricia

    2007-01-01

    Student use of electronic books has become an accepted supplement to traditional resources. Student use and satisfaction was monitored through an online course discussion board. Increased use of electronic books indicate this service is an accepted supplement to the print book collection.

  13. End-of-life resource recovery from emerging electronic products

    DEFF Research Database (Denmark)

    Parajuly, Keshav; Habib, Komal; Cimpan, Ciprian

    2016-01-01

    -case scenario, only 47% of the total materials in RVCs are ultimately recycled. While this low material recovery is mainly due to the lower plastic recycling rate, other market realities and the complex material flows in the recycling chain also contribute to it. The study provides a robust methodological...... at a conventional ‘shred-and-separate’ type preprocessing plant in Denmark. A detailed material flow analysis was performed throughout the recycling chain. The results show a mismatch between product design and EoL processing, and the lack of practical implementation of ‘Design for EoL’ thinking. In the best...... approach for assessing the EoL performance based on the knowledge of a product and its complex recycling chain. The lessons learned can be used to support both the design and EoL processing of products with similar features, which carry a high potential for resource recovery, especially at the initial...

  14. Electronic textbooks as a professional resource after dental school.

    Science.gov (United States)

    Bates, Michael L; Strother, Elizabeth A; Brunet, Darlene P; Gallo, John R

    2012-05-01

    In two previous studies of dental students' attitudes about the VitalSource Bookshelf, a digital library of dental textbooks, students expressed negative opinions about owning and reading electronic textbooks. With the assumption that dentists would find the digital textbooks useful for patient care, the authors surveyed recent graduates to determine if their attitude toward the VitalSource Bookshelf had changed. A brief survey was sent to 119 alumni from the classes of 2009 and 2010 of one U.S. dental school. Forty-seven (39.5 percent) completed the questionnaire. Eighteen respondents (48.3 percent) reported using the e-textbooks often or sometimes. The twenty-nine dentists who said they have not used the collection since graduation reported preferring print books or other online sources or having technical problems when downloading the books to a new computer. Only five respondents selected the VitalSource Bookshelf as a preferred source of professional information. Most of the respondents reported preferring to consult colleagues (37.8 percent), the Internet (20 percent), or hardcopy books (17.8 percent) for information. When asked in an open-ended question to state their opinion of the Bookshelf, nineteen (42.2 percent) responded positively, but almost one-third of these only liked the search feature. Six respondents reported that they never use the program. Twenty-two said they have had technical problems with the Bookshelf, including fifteen who have not been able to install it on a new computer. Many of them said they have not followed up with either the dental school or VitalSource support services to overcome this problem. Our study suggests that dentists, similar to dental students, dislike reading electronic textbooks, even with the advantage of searching a topic across more than sixty dental titles.

  15. Oceanography of the subarctic Pacific region, 1960-71

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This report is on the oceanography of the subarctic Pacific region 1969-1971. The background of the project is summarized. Next, a review of physical oceanography...

  16. Analytical Study of Usage of Electronic Information Resources at Pharmacopoeial Libraries in India

    Directory of Open Access Journals (Sweden)

    Sunil Tyagi

    2014-02-01

    Full Text Available The objective of this study is to know the rate and purpose of the use of e-resource by the scientists at pharmacopoeial libraries in India. Among other things, this study examined the preferences of the scientists toward printed books and journals, electronic information resources, and pattern of using e-resources. Non-probability sampling specially accidental and purposive technique was applied in the collection of primary data through administration of user questionnaire. The sample respondents chosen for the study consists of principle scientific officer, senior scientific officer, scientific officer, and scientific assistant of different division of the laboratories, namely, research and development, pharmaceutical chemistry, pharmacovigilance, pharmacology, pharmacogonosy, and microbiology. The findings of the study reveal the personal experiences and perceptions they have had on practice and research activity using e-resource. The major findings indicate that of the total anticipated participants, 78% indicated that they perceived the ability to use computer for electronic information resources. The data analysis shows that all the scientists belonging to the pharmacopoeial libraries used electronic information resources to address issues relating to drug indexes and compendia, monographs, drugs obtained through online databases, e-journals, and the Internet sources—especially polices by regulatory agencies, contacts, drug promotional literature, and standards.

  17. Connecting knowledge resources to the veterinary electronic health record: opportunities for learning at point of care.

    Science.gov (United States)

    Alpi, Kristine M; Burnett, Heidi A; Bryant, Sheila J; Anderson, Katherine M

    2011-01-01

    Electronic health records (EHRs) provide clinical learning opportunities through quick and contextual linkage of patient signalment, symptom, and diagnosis data with knowledge resources covering tests, drugs, conditions, procedures, and client instructions. This paper introduces the EHR standards for linkage and the partners-practitioners, content publishers, and software developers-necessary to leverage this possibility in veterinary medicine. The efforts of the American Animal Hospital Association (AAHA) Electronic Health Records Task Force to partner with veterinary practice management systems to improve the use of controlled vocabulary is a first step in the development of standards for sharing knowledge at the point of care. The Veterinary Medical Libraries Section (VMLS) of the Medical Library Association's Task Force on Connecting the Veterinary Health Record to Information Resources compiled a list of resources of potential use at point of care. Resource details were drawn from product Web sites and organized by a metric used to evaluate medical point-of-care resources. Additional information was gathered from questions sent by e-mail and follow-up interviews with two practitioners, a hospital network, two software developers, and three publishers. Veterinarians with electronic records use a variety of information resources that are not linked to their software. Systems lack the infrastructure to use the Infobutton standard that has been gaining popularity in human EHRs. While some veterinary knowledge resources are digital, publisher sites and responses do not indicate a Web-based linkage of veterinary resources with EHRs. In order to facilitate lifelong learning and evidence-based practice, veterinarians and educators of future practitioners must demonstrate to veterinary practice software developers and publishers a clinically-based need to connect knowledge resources to veterinary EHRs.

  18. Elektronik Bilgi Kaynaklarının Seçimi / Selection of Electronic Information Resources

    Directory of Open Access Journals (Sweden)

    Pınar Al

    2003-04-01

    Full Text Available For many years, library users have used only from the printed media in order to get the information that they have needed. Today with the widespread use of the Web and the addition of electronic information resources to library collections, the use of information in the electronic environment as well as in printed media is started to be used. In time, such types of information resources as, electronic journals, electronic books, electronic encyclopedias, electronic dictionaries and electronic theses have been added to library collections. In this study, selection criteria that can be used for electronic information resources are discussed and suggestions are provided for libraries that try to select electronic information resources for their collections.

  19. Considering Point-of-Care Electronic Medical Resources in Lieu of Traditional Textbooks for Medical Education.

    Science.gov (United States)

    Hale, LaDonna S; Wallace, Michelle M; Adams, Courtney R; Kaufman, Michelle L; Snyder, Courtney L

    2015-09-01

    Selecting resources to support didactic courses is a critical decision, and the advantages and disadvantages must be carefully considered. During clinical rotations, students not only need to possess strong background knowledge but also are expected to be proficient with the same evidence-based POC resources used by clinicians. Students place high value on “real world” learning and therefore may place more value on POC resources that they know practicing clinicians use as compared with medical textbooks. The condensed nature of PA education requires students to develop background knowledge and information literacy skills over a short period. One way to build that knowledge and those skills simultaneously is to use POC resources in lieu of traditional medical textbooks during didactic training. Electronic POC resources offer several advantages over traditional textbooks and should be considered as viable options in PA education.

  20. Awareness and use of electronic resources at a university campus in ...

    African Journals Online (AJOL)

    This study looks into the use of electronic resources by the faculty members of College of Technology Education, Kumasi of the University of Education, Winneba, Ghana. Sixty-two copies of a questionnaire were sent to the entire faculty and 31 were returned which gave a response rate of 50%. The responses showed very ...

  1. Localising versus standardising electronic human resource management: complexities and tensions between HRM and IT departments

    NARCIS (Netherlands)

    Tate, Mary; Furtmueller-Ettinger, Elfriede; Wilderom, Celeste P.M.

    2013-01-01

    In this paper, we provide an analysis of the complexities involved during global e-HRM (Electronic Human Resource Management) implementation. We present findings from a case study on the challenge of global integration versus local responsiveness of e-HRM systems. We take a local site lens,

  2. Perceived Effect of Accessibility and Utilization of Electronic Resources on Productivity of Academic Staff in Selected Nigerian Universities

    Directory of Open Access Journals (Sweden)

    Okon E. Ani

    2015-10-01

    Full Text Available Access to information is vital for efficient research at universities. Electronic resources provide new platforms for information to aid in conducting research at universities. This study explores the perceived effect of accessibility and utilization of electronic resources on research productivity at Nigerian universities. A quantitative research approach was adopted for the study with a survey as research method. Data were collected for the study with a self-reporting questionnaire. Regression analysis in the study revealed that accessibility and use of electronic resources had a significant perceived positive effect on research productivity at the surveyed Nigerian universities. However, there was no significant perceived effect of accessibility and use of electronic resources by discipline on research productivity in the survey. In terms of gender, it was found that there was no significant perceived effect of accessibility and use of electronic resources by gender on research productivity among respondents at the surveyed Nigerian universities. Based on these findings, it is recommended that effective development of digital libraries in Nigerian universities would ameliorate the problems of accessibility and utilization of electronic resources by academic staff in research. Furthermore, the Nigerian university libraries should develop an electronic collection development policy to enhance equitable access and use of electronic resources at Nigerian universities. Policy for sustainable digitization of relevant library materials should be evolved to support digital libraries effectively for efficient accessibility and utilization of electronic resources.

  3. Library Electronic Resource Sharing Among Liberal Arts Colleges: ACS Palladian Alliance Project

    Directory of Open Access Journals (Sweden)

    Wenxian Zhang

    1997-03-01

    Full Text Available 無Effective electronic resource sharing is critical to library information services of the 1990s. Explosion of data and increased cost of information force libraries to work together, and technological advancements present the library service profession a platform for resource sharing. The Palladian Alliance Project of the Associated Colleges of the South is designed to provides ACS member institutions an effective means to enhance information access for their faculty and students, and achieve significant cost containment in the years to come.

  4. Acetaldehyde in the Alaskan subarctic snowpack

    Directory of Open Access Journals (Sweden)

    F. Domine

    2010-02-01

    Full Text Available Acetaldehyde is a reactive intermediate in hydrocarbon oxidation. It is both emitted and taken up by snowpacks and photochemical and physical processes are probably involved. Understanding the reactivity of acetaldehyde in snow and its processes of physical and chemical exchanges requires the knowledge of its incorporation mechanism in snow crystals. We have performed a season-long study of the evolution of acetaldehyde concentrations in the subarctic snowpack near Fairbanks (65° N, central Alaska, which is subjected to a vigorous metamorphism due to persistent elevated temperature gradients in the snowpack, between 20 and 200° C m−1. The snowpack therefore almost entirely transforms into depth hoar. We have also analyzed acetaldehyde in a manipulated snowpack where temperature gradients were suppressed. Snow crystals there transformed much more slowly and their original shapes remained recognizable for months. The specific surface area of snow layers in both types of snowpacks was also measured. We deduce that acetaldehyde is not adsorbed onto the surface of snow crystals and that most of the acetaldehyde is probably not dissolved in the ice lattice of the snow crystals. We propose that most of the acetaldehyde measured is either trapped or dissolved within organic aerosol particles trapped in snow, or that acetaldehyde is formed by the hydrolysis of organic precursors contained in organic aerosols trapped in the snow, when the snow is melted for analysis. These precursors are probably aldehyde polymers formed within the aerosol particles by acid catalysis, but might also be biological molecules. In a laboratory experiment, acetaldehyde-di-n-hexyl acetal, representing a potential acetaldehyde precursor, was subjected to our analytical procedure and reacted to form acetaldehyde. This confirms our suggestion that acetaldehyde detected in snow could be produced during the melting of snow for analysis.

  5. Subarctic physicochemical weathering of serpentinized peridotite

    Science.gov (United States)

    Ulven, O. I.; Beinlich, A.; Hövelmann, J.; Austrheim, H.; Jamtveit, B.

    2017-06-01

    Frost weathering is effective in arctic and subarctic climate zones where chemical reactions are limited by the reduced availability of liquid water and the prevailing low temperature. However, small scale mineral dissolution reactions are nevertheless important for the generation of porosity by allowing infiltration of surface water with subsequent fracturing due to growth of ice and carbonate minerals. Here we combine textural and mineralogical observations in natural samples of partly serpentinized ultramafic rocks with a discrete element model describing the fracture mechanics of a solid when subject to pressure from the growth of ice and carbonate minerals in surface-near fractures. The mechanical model is coupled with a reaction-diffusion model that describes an initial stage of brucite dissolution as observed during weathering of serpentinized harzburgites and dunites from the Feragen Ultramafic Body (FUB), SE-Norway. Olivine and serpentine are effectively inert at relevant conditions and time scales, whereas brucite dissolution produces well-defined cm to dm thick weathering rinds with elevated porosity that allows influx of water. Brucite dissolution also increases the water saturation state with respect to hydrous Mg carbonate minerals, which are commonly found as infill in fractures in the fresh rock. This suggests that fracture propagation is at least partly driven by carbonate precipitation. Dissolution of secondary carbonate minerals during favorable climatic conditions provides open space available for ice crystallization that drives fracturing during winter. Our model reproduces the observed cm-scale meandering fractures that propagate into the fresh part of the rock, as well as dm-scale fractures that initiate the breakup of larger domains. Rock disintegration increases the reactive surface area and hence the rate of chemical weathering, enhances transport of dissolved and particulate matter in the weathering fluid, and facilitates CO2 uptake by

  6. ELECTRONIC EDUCATIONAL RESOURCES FOR ONLINE SUPPORT OF MODERN CHEMISTRY CLASSES IN SPECIALIZED SCHOOL

    OpenAIRE

    Maria D. Tukalo

    2013-01-01

    This article contains material of some modern electronic educational resources that can be used via the Internet to support the modern chemistry classes in specialized school. It was drawn attention to the educational chemical experiments as means of knowledge; simulated key motivational characteristics to enhance students interest for learning subjects, their cognitive and practical activity in the formation of self-reliance and self-creative; commented forecasts for creating of conditions t...

  7. A systematic review of portable electronic technology for health education in resource-limited settings.

    Science.gov (United States)

    McHenry, Megan S; Fischer, Lydia J; Chun, Yeona; Vreeman, Rachel C

    2017-08-01

    The objective of this study is to conduct a systematic review of the literature of how portable electronic technologies with offline functionality are perceived and used to provide health education in resource-limited settings. Three reviewers evaluated articles and performed a bibliography search to identify studies describing health education delivered by portable electronic device with offline functionality in low- or middle-income countries. Data extracted included: study population; study design and type of analysis; type of technology used; method of use; setting of technology use; impact on caregivers, patients, or overall health outcomes; and reported limitations. Searches yielded 5514 unique titles. Out of 75 critically reviewed full-text articles, 10 met inclusion criteria. Study locations included Botswana, Peru, Kenya, Thailand, Nigeria, India, Ghana, and Tanzania. Topics addressed included: development of healthcare worker training modules, clinical decision support tools, patient education tools, perceptions and usability of portable electronic technology, and comparisons of technologies and/or mobile applications. Studies primarily looked at the assessment of developed educational modules on trainee health knowledge, perceptions and usability of technology, and comparisons of technologies. Overall, studies reported positive results for portable electronic device-based health education, frequently reporting increased provider/patient knowledge, improved patient outcomes in both quality of care and management, increased provider comfort level with technology, and an environment characterized by increased levels of technology-based, informal learning situations. Negative assessments included high investment costs, lack of technical support, and fear of device theft. While the research is limited, portable electronic educational resources present promising avenues to increase access to effective health education in resource-limited settings, contingent

  8. Potential resource and toxicity impacts from metals in waste electronic devices.

    Science.gov (United States)

    Woo, Seung H; Lee, Dae Sung; Lim, Seong-Rin

    2016-04-01

    As a result of the continuous release of new electronic devices, existing electronic devices are quickly made obsolete and rapidly become electronic waste (e-waste). Because e-waste contains a variety of metals, information about those metals with the potential for substantial environmental impact should be provided to manufacturers, recyclers, and disposers to proactively reduce this impact. This study assesses the resource and toxicity (i.e., cancer, noncancer, and ecotoxicity) potentials of various heavy metals commonly found in e-waste from laptop computers, liquid-crystal display (LCD) monitors, LCD TVs, plasma TVs, color cathode ray tube (CRT) TVs, and cell phones and then evaluates such potentials using life cycle impact-based methods. Resource potentials derive primarily from Cu, Sb, Ag, and Pb. Toxicity potentials derive primarily from Pb, Ni, and Hg for cancer toxicity; from Pb, Hg, Zn, and As for noncancer toxicity; and from Cu, Pb, Hg, and Zn for ecotoxicity. Therefore, managing these heavy metals should be a high priority in the design, recycling, and disposal stages of electronic devices. © 2015 SETAC.

  9. Selected References on Arctic and Subarctic Prehistory and Ethnology. Revised.

    Science.gov (United States)

    Fitzhugh, William, Comp.; Loring, Stephen, Comp.

    This bibliography provides an introduction to the current literature, in English, on arctic and subarctic prehistory and ethnology. Leads for further research will be found in section 1. Publications listed are not available from the Smithsonian Institution but copies may be found in larger libraries or obtained through inter-library loan.…

  10. Anurans in a Subarctic Tundra Landscape Near Cape Churchill, Manitoba

    Science.gov (United States)

    Reiter, M.E.; Boal, C.W.; Andersen, D.E.

    2008-01-01

    Distribution, abundance, and habitat relationships of anurans inhabiting subarctic regions are poorly understood, and anuran monitoring protocols developed for temperate regions may not be applicable across large roadless areas of northern landscapes. In addition, arctic and subarctic regions of North America are predicted to experience changes in climate and, in some areas, are experiencing habitat alteration due to high rates of herbivory by breeding and migrating waterfowl. To better understand subarctic anuran abundance, distribution, and habitat associations, we conducted anuran calling surveys in the Cape Churchill region of Wapusk National Park, Manitoba, Canada, in 2004 and 2005. We conducted surveys along ~l-km transects distributed across three landscape types (coastal tundra, interior sedge meadow-tundra, and boreal forest-tundra interface) to estimate densities and probabilities of detection of Boreal Chorus Frogs (Pseudacris maculata) and Wood Frogs (Lithobates sylvaticus). We detected a Wood Frog or Boreal Chorus Frog on 22 (87%) of 26 transects surveyed, but probability of detection varied between years and species and among landscape types. Estimated densities of both species increased from the coastal zone inland toward the boreal forest edge. Our results suggest anurans occur across all three landscape types in our study area, but that species-specific spatial patterns exist in their abundances. Considerations for both spatial and temporal variation in abundance and detection probability need to be incorporated into surveys and monitoring programs for subarctic anurans.

  11. Opening a Can of wERMS: Texas A&M University's Experiences in Implementing Two Electronic Resource Management Systems

    Science.gov (United States)

    Hartnett, Eric; Price, Apryl; Smith, Jane; Barrett, Michael

    2010-01-01

    Over the past few years, Texas A&M University (TAMU) has searched for a way to administer its electronic subscriptions as well as the electronic subscriptions shared among the TAMU System. In this article, we address our attempts to implement an effective electronic resource management system (ERMS), both for subscriptions on the main campus…

  12. Model of e-learning with electronic educational resources of new generation

    Directory of Open Access Journals (Sweden)

    A. V. Loban

    2017-01-01

    Full Text Available Purpose of the article: improving of scientific and methodical base of the theory of the е-learning of variability. Methods used: conceptual and logical modeling of the е-learning of variability process with electronic educational resource of new generation and system analysis of the interconnection of the studied subject area, methods, didactics approaches and information and communication technologies means. Results: the formalization complex model of the е-learning of variability with electronic educational resource of new generation is developed, conditionally decomposed into three basic components: the formalization model of the course in the form of the thesaurusclassifier (“Author of e-resource”, the model of learning as management (“Coordination. Consultation. Control”, the learning model with the thesaurus-classifier (“Student”. Model “Author of e-resource” allows the student to achieve completeness, high degree of didactic elaboration and structuring of the studied material in triples of variants: modules of education information, practical task and control tasks; the result of the student’s (author’s of e-resource activity is the thesaurus-classifier. Model of learning as management is based on the principle of personal orientation of learning in computer environment and determines the logic of interaction between the lecturer and the student when determining the triple of variants individually for each student; organization of a dialogue between the lecturer and the student for consulting purposes; personal control of the student’s success (report generation and iterative search for the concept of the class assignment in the thesaurus-classifier before acquiring the required level of training. Model “Student” makes it possible to concretize the learning tasks in relation to the personality of the student and to the training level achieved; the assumption of the lecturer about the level of training of a

  13. Epipelagic nekton of the North Pacific Subarctic and Transition Zones

    Science.gov (United States)

    Brodeur, Richard; McKinnell, Skip; Nagasawa, Kazuya; Pearcy, William; Radchenko, Vladimir; Takagi, Shogo

    1999-03-01

    During the 1980s and 1990s, scientific research cruises and commercial gillnet operations with scientific observers aboard were conducted throughout much of the Subarctic and Transition Zones of the North Pacific Ocean. These studies produced one of the most extensive databases ever collected on the relative species composition and trophic structure of epipelagic nekton of the Subarctic and Transition Zones in the North Pacific Ocean. Data from Japanese high-seas gillnet research surveys (1981-1991) were examined using multivariate analytical techniques to analyse community structure of nektonic cephalopods, elasmobranchs, and teleosts in the North Pacific Subarctic and Transition Zones during the summer months, emphasizing differences between the eastern and western Subarctic Gyres. Species diversity generally increased going from west to east, which was apparently associated with the greater range of temperatures in the east. Discriminant analysis was able to correctly classify about half the catch locations into their respective regions. Catches from multinational drift gillnet commercial fisheries operations in 1990-1991 mainly in the Transition Zone were also examined. Classification techniques were employed to determine species associations and multivariate analyses were used to examine relationships of these assemblages to environmental data. We found that some species are often captured in the same gillnet sets and form species associations that are distinct in ordination space, but these associations are loose and may vary appreciably from year to year. We review recent studies on the feeding habits and daily ration of the dominant species and construct food webs for the eastern and western Subarctic and Transition Zone systems emphasizing the role that nekton play in these pelagic ecosystems.

  14. Theoretical Aspects of the Use of Electronic Educational Resources in Professional Activity of Future Teachers of Technology

    Directory of Open Access Journals (Sweden)

    Iryna Smyrnova

    2017-06-01

    Full Text Available In this paper, we tried to determine the requirements for ESM, to study theoretical aspects of electronic educational resources in the professional activity of future teachers. The results created by the introduction of our course “Methodology development and use of electronic educational resources” for future teachers of technology ITOS in the process of professional specialty “Technology” in the educational process of higher educational institutions of Ukraine. The article states the rapid development of computer hardware and computer software, IT technologies have an opportunity to significantly develop the field of electronic educational resources. This is due to the emergence of global networks where information technologies have become the second paradigm, which is based on the current understanding of electronic educational resources. We determined that the dynamism inherent in information technology, enabling expectations of new approaches that will change the meaning of electronic educational resources.

  15. Postgraduate medical students' acceptance and understanding of scientific information databases and electronic resources.

    Science.gov (United States)

    Azami, Mohammad; Khajouei, Reza; Rakhshani, Safiyeh

    2016-03-01

    The significance and validity of web-based scientific databases are increasing dramatically in the scientific community. Moreover, a great number of students use these resources without having sufficient and accurate knowledge and understanding. In order for students to use these databases and electronic resources optimally, identifying the factors that affect the understanding and acceptance of these resources seems necessary. The aim of this study was to determine postgraduate medical students' acceptance and understanding of these resources. This cross-sectional study was conducted on 311 postgraduate medical students from Kerman University of Medical Science (KMU) in 2013. Data were collected using a researcher-made questionnaire, and the data were analyzed using SPSS. In order to design the model (i.e., the interaction between study variables and to determine the relationships between them in an integrated pattern), LISREL version 8.7 and a structural equation model were used. Descriptive statistics and t-tests also were used in data analysis. The results showed that the average components of the perception of usefulness, perception of ease of use, attitude towards use, decision to use, using to perform duties, and using to increase knowledge were 4.31, 4.14, 4.24, 16.27, 20.85, and 16.13 respectively. Accordingly, the average of all these indicators was significantly higher than the assumed amount (p < 0.01). Moreover, the results obtained from factor analysis and the structural equation model indicated that the model of the present study fit the data perfectly. Based on the findings of this study, the more these databases are considered useful and easy to use, the more they are used. Therefore, designers of databases and electronic resources can design systems that are both useful and easy to learn by considering the components of the research model.

  16. SubArctic Oceans and Global Climate

    Science.gov (United States)

    Rhines, P. B.

    2004-12-01

    The passages connecting the Arctic Ocean with the Atlantic and Pacific, and their `mediterranean' basins, are focal points for the global meridional overturning circulation, and all of the climate impacts which this implies. It is also a difficult region to model accurately: the sensitivity of climate models to subpolar ocean dynamics is well-known. In this talk we stress the need to instrument and analyze the subpolar oceans, and some examples of sustained observations developing there. Results from satellite altimetry, recent Seaglider deployments from Greenland, and mooring arrays will be described. In particular we show the first Seaglider sections of hydrography and bio-optical profiles of the Labrador Sea (one of the first extended deployments of this autonomous undersea vehicle); we discuss the decline during the 1990s of the subpolar gyre circulation of the Atlantic from its great strength during the positive NAO period of the early 1990s, and its relevance to the salinity decline observed over a much longer period; we review observations of the flows at the Iceland-Scotland Ridge and Davis Strait, argued in terms of volume transport plots on the potential temperature/salinity plane; we display maps of the `convection resistance' (related to dynamic height) and its sensitivity to surface low-salinity water masses and their partition between shallow continental shelves and deep ocean. This is a particularly exciting time for climate studies, with fundamental properties of the atmosphere-ocean circulation under debate, even before one considers natural and human-induced variability. Is the four-decade long decline in subArctic salinity the result of increased hydrologic cycle, increased or altered Arctic outflow to the Atlantic, or slowing of the subpolar circulation? Is the basic intensity of the MOC more dependent on high-latitude buoyancy forcing, or wind- or tide-driven mixing in the upwelling branch, or possibly wind-stress at high latitude? Is the

  17. Review of material recovery from used electric and electronic equipment-alternative options for resource conservation.

    Science.gov (United States)

    Friege, Henning

    2012-09-01

    For waste from electric and electronic equipment, the WEEE Directive stipulates the separate collection of electric and electronic waste. As to new electric and electronic devices, the Restriction of Hazardous Substances (RoHS) Directive bans the use of certain chemicals dangerous for man and environment. From the implementation of the WEEE directive, many unsolved problems have been documented: poor collection success, emission of dangerous substances during collection and recycling, irretrievable loss of valuable metals among others. As to RoHS, data from the literature show a satisfying success. The problems identified in the process can be reduced to some basic dilemmas at the borders between waste management, product policy and chemical safety. The objectives of the WEEE Directive and the specific targets for use and recycling of appliances are not consistent. There is no focus on scarce resources. Extended producer responsibility is not sufficient to guarantee sustainable waste management. Waste management reaches its limits due to problems of implementation but also due to physical laws. A holistic approach is necessary looking at all branch points and sinks in the stream of used products and waste from electric and electronic equipment. This may be done with respect to the general rules for sustainable management of material streams covering the three dimensions of sustainable policy. The relationships between the players in the field of electric and electronic devices have to be taken into account. Most of the problems identified in the implementation process will not be solved by the current amendment of the WEEE Directive.

  18. Integrating electronic information resources for NHS Glasgow staff at the point of need: a model of interlibrary collaboration and resource sharing.

    Science.gov (United States)

    Davies, S; Wales, A

    2001-12-01

    The Glasgow NHS Libraries Consortium has harnessed the political imperative of collaboration and the capability of electronic information resources to address inequalities in access to the knowledge base across NHS Glasgow. They have negotiated consortium arrangements to an extensive range of electronic databases and journals which no single Glasgow NHS library could afford independently. A Project Officer was appointed to undertake the administration, technical work and promotion required to build a Web-based electronic library to deliver resources to all NHS Glasgow staff on an equitable basis. Close partnership with online content providers enabled the Project Officer to find solutions to problems caused by authentication systems and license restrictions. These efforts have culminated in the production of a fully integrated virtual library--the NHS Glasgow e-Library--delivering 11 major electronic databases, 440 full-text electronic journals, 48 electronic textbooks and over 5000 journal contents pages. The NHS Glasgow e-Library is without precedent within the NHS in terms of its wealth of resources, and it provides a model for Scotland-wide access to the knowledge base. The sustainability and transferability of the resource is dependent on a number of key areas-maintenance, user training, evaluation, IT infrastructure and ongoing collaboration and unification. Ongoing research will monitor how far the NHS Glasgow e-Library has strengthened the connection between research evidence and clinical practice.

  19. Comparing Electronic Human Resource Management Systems Efficiency In Production Organization amp Service Organizations

    Directory of Open Access Journals (Sweden)

    Ali Hadian

    2015-08-01

    Full Text Available Today the organizations used information technology in performing human resource department affairs and this is called as electronic human resource management EHRM. In fact as the competitive complexity increases the need for implementing EHRM in production and service businesses increases too. This paper is written in order to specify the importance of implementing EHRM in production and service organizations and also to evaluate efficiency rate and the importance degree in these two ones. In this paper first the topics literature and the most important aspects of implementing these systems will be reviewed and after categorizing these views the hierarchal model will be proposed by applying AHP method. The result of analyzing this model by EXPERT CHOICE software shows that implementing EHRM in both kinds of organizations has the same importance however there is a large difference between them in implementing aspects.

  20. The Synthesis of the Hierarchical Structure of Information Resources for Management of Electronic Commerce Entities

    Directory of Open Access Journals (Sweden)

    Krutova Anzhelika S.

    2017-06-01

    Full Text Available The aim of the article is to develop the theoretical bases for the classification and coding of economic information and the scientific justification of the content of information resources of an electronic commerce enterprise. The essence of information resources for management of electronic business entities is investigated. It is proved that the organization of accounting in e-commerce systems is advisable to be built on the basis of two circuits: accounting for financial flows and accounting associated with transformation of business factors in products and services as a result of production activities. There presented a sequence of accounting organization that allows to combine the both circuits in a single information system, which provides a possibility for the integrated replenishment and distributed simultaneous use of the e-commerce system by all groups of users. It is proved that the guarantee of efficient activity of the information management system of electronic commerce entities is a proper systematization of the aggregate of information resources on economic facts and operations of an enterprise in accordance with the management tasks by building the hierarchy of accounting nomenclatures. It is suggested to understand nomenclature as an objective, primary information aggregate concerning a certain fact of the economic activity of an enterprise, which is characterized by minimum requisites, is entered into the database of the information system and is to be reflected in the accounting system. It is proposed to build a database of e-commerce systems as a part of directories (constants, personnel, goods / products, suppliers, buyers and the hierarchy of accounting nomenclatures. The package of documents regulating the organization of accounting at an enterprise should include: the provision on the accounting services, the order on the accounting policy, the job descriptions, the schedules of information exchange, the report card and

  1. ELECTRONIC EDUCATIONAL RESOURCES FOR ONLINE SUPPORT OF MODERN CHEMISTRY CLASSES IN SPECIALIZED SCHOOL

    Directory of Open Access Journals (Sweden)

    Maria D. Tukalo

    2013-09-01

    Full Text Available This article contains material of some modern electronic educational resources that can be used via the Internet to support the modern chemistry classes in specialized school. It was drawn attention to the educational chemical experiments as means of knowledge; simulated key motivational characteristics to enhance students interest for learning subjects, their cognitive and practical activity in the formation of self-reliance and self-creative; commented forecasts for creating of conditions to enhance the creative potential of students in a modern learning environment.

  2. Mineralization and carbon turnover in subarctic heath soil as affected by warming and additional litter

    DEFF Research Database (Denmark)

    Rinnan, Riikka; Michelsen, Anders; Baath, Erland

    2007-01-01

    Arctic soil carbon (C) stocks are threatened by the rapidly advancing global warming. In addition to temperature, increasing amounts of leaf litter fall following from the expansion of deciduous shrubs and trees in northern ecosystems may alter biogeochemical cycling of C and nutrients. Our aim...... was to assess how factorial warming and litter addition in a long-term field experiment on a subarctic heath affect resource limitation of soil microbial communities (measured by thymidine and leucine incorporation techniques), net growing-season mineralization of nitrogen (N) and phosphorus (P), and carbon...... the field incubation. The added litter did not affect the carbon content, but it was a source of nutrients to the soil, and it also tended to increase bacterial growth rate and net mineralization of P. The inorganic N pool decreased during the field incubation of soil cores, especially in the separate...

  3. THE MODEL OF LINGUISTIC TEACHERS’ COMPETENCY DEVELOPMENT ON DESIGNING MULTIMEDIA ELECTRONIC EDUCATIONAL RESOURCES IN THE MOODLE SYSTEM

    Directory of Open Access Journals (Sweden)

    Anton M. Avramchuk

    2017-10-01

    Full Text Available The article is devoted to the problem of developing the competency of teachers of language disciplines on designing multimedia electronic educational resources in the Moodle system. The concept of "the competence of teachers of language disciplines on designing multimedia electronic educational resources in the Moodle system" is justified and defined. Identified and characterized the components by which the levels of the competency development of teachers of language disciplines on designing multimedia electronic educational resources in the Moodle system should be assessed. Developed a model for the development of the competency of teachers of language disciplines on designing multimedia electronic educational resources in the Moodle system, which is based on the main scientific approaches, used in adult education, and consists of five blocks: target, informative, technological, diagnostic and effective.

  4. Open-Source Electronic Health Record Systems for Low-Resource Settings: Systematic Review.

    Science.gov (United States)

    Syzdykova, Assel; Malta, André; Zolfo, Maria; Diro, Ermias; Oliveira, José Luis

    2017-11-13

    Despite the great impact of information and communication technologies on clinical practice and on the quality of health services, this trend has been almost exclusive to developed countries, whereas countries with poor resources suffer from many economic and social issues that have hindered the real benefits of electronic health (eHealth) tools. As a component of eHealth systems, electronic health records (EHRs) play a fundamental role in patient management and effective medical care services. Thus, the adoption of EHRs in regions with a lack of infrastructure, untrained staff, and ill-equipped health care providers is an important task. However, the main barrier to adopting EHR software in low- and middle-income countries is the cost of its purchase and maintenance, which highlights the open-source approach as a good solution for these underserved areas. The aim of this study was to conduct a systematic review of open-source EHR systems based on the requirements and limitations of low-resource settings. First, we reviewed existing literature on the comparison of available open-source solutions. In close collaboration with the University of Gondar Hospital, Ethiopia, we identified common limitations in poor resource environments and also the main requirements that EHRs should support. Then, we extensively evaluated the current open-source EHR solutions, discussing their strengths and weaknesses, and their appropriateness to fulfill a predefined set of features relevant for low-resource settings. The evaluation methodology allowed assessment of several key aspects of available solutions that are as follows: (1) integrated applications, (2) configurable reports, (3) custom reports, (4) custom forms, (5) interoperability, (6) coding systems, (7) authentication methods, (8) patient portal, (9) access control model, (10) cryptographic features, (11) flexible data model, (12) offline support, (13) native client, (14) Web client,(15) other clients, (16) code

  5. Success criteria for electronic medical record implementations in low-resource settings: a systematic review.

    Science.gov (United States)

    Fritz, Fleur; Tilahun, Binyam; Dugas, Martin

    2015-03-01

    Electronic medical record (EMR) systems have the potential of supporting clinical work by providing the right information at the right time to the right people and thus make efficient use of resources. This is especially important in low-resource settings where reliable data are also needed to support public health and local supporting organizations. In this systematic literature review, our objectives are to identify and collect literature about success criteria of EMR implementations in low-resource settings and to summarize them into recommendations. Our search strategy relied on PubMed queries and manual bibliography reviews. Studies were included if EMR implementations in low-resource settings were described. The extracted success criteria and measurements were summarized into 7 categories: ethical, financial, functionality, organizational, political, technical, and training. We collected 381 success criteria with 229 measurements from 47 articles out of 223 articles. Most papers were evaluations or lessons learned from African countries, published from 1999 to 2013. Almost half of the EMR systems served a specific disease area like human immunodeficiency virus (HIV). The majority of criteria that were reported dealt with the functionality, followed by organizational issues, and technical infrastructures. Sufficient training and skilled personnel were mentioned in roughly 10%. Political, ethical, and financial considerations did not play a predominant role. More evaluations based on reliable frameworks are needed. Highly reliable data handling methods, human resources and effective project management, as well as technical architecture and infrastructure are all key factors for successful EMR implementation. © The Author 2015. Published by Oxford University Press on behalf of the American Medical Informatics Association. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  6. Impact of Knowledge Resources Linked to an Electronic Health Record on Frequency of Unnecessary Tests and Treatments

    Science.gov (United States)

    Goodman, Kenneth; Grad, Roland; Pluye, Pierre; Nowacki, Amy; Hickner, John

    2012-01-01

    Introduction: Electronic knowledge resources have the potential to rapidly provide answers to clinicians' questions. We sought to determine clinicians' reasons for searching these resources, the rate of finding relevant information, and the perceived clinical impact of the information they retrieved. Methods: We asked general internists, family…

  7. Resource conservation approached with an appropriate collection and upgrade-remanufacturing for used electronic products.

    Science.gov (United States)

    Zlamparet, Gabriel I; Tan, Quanyin; Stevels, A B; Li, Jinhui

    2018-03-01

    This comparative research represents an example for a better conservation of resources by reducing the amount of waste (kg) and providing it more value under the umbrella of remanufacturing. The three discussed cases will expose three issues already addressed separately in the literature. The generation of waste electrical and electronic equipment (WEEE) interacts with the environmental depletion. In this article, we gave the examples of addressed issues under the concept of remanufacturing. Online collection opportunity eliminating classical collection, a business to business (B2B) implementation for remanufactured servers and medical devices. The material reuse (recycling), component sustainability, reuse (part harvesting), product reuse (after repair/remanufacturing) indicates the recovery potential using remanufacturing tool for a better conservation of resources adding more value to the products. Our findings can provide an overview of new system organization for the general collection, market potential and the technological advantages using remanufacturing instead of recycling of WEEE or used electrical and electronic equipment. Copyright © 2017. Published by Elsevier Ltd.

  8. Reducing clinical trial monitoring resource allocation and costs through remote access to electronic medical records.

    Science.gov (United States)

    Uren, Shannon C; Kirkman, Mitchell B; Dalton, Brad S; Zalcberg, John R

    2013-01-01

    With electronic medical records (eMRs), the option now exists for clinical trial monitors to perform source data verification (SDV) remotely. We report on a feasibility study of remote access to eMRs for SDV and the potential advantages of such a process in terms of resource allocation and cost. The Clinical Trials Unit at the Peter MacCallum Cancer Centre, in collaboration with Novartis Pharmaceuticals Australia, conducted a 6-month feasibility study of remote SDV. A Novartis monitor was granted dedicated software and restricted remote access to the eMR portal of the cancer center, thereby providing an avenue through which perform SDV. Six monitoring visits were conducted during the study period, four of which were performed remotely. The ability to conduct two thirds of the monitoring visits remotely in this complex phase III study resulted in an overall cost saving to Novartis. Similarly, remote monitoring eased the strain on internal resources, particularly monitoring space and hospital computer terminal access, at the cancer center. Remote access to patient eMRs for SDV is feasible and is potentially an avenue through which resources can be more efficiently used. Although this feasibility study involved limited numbers, there is no limit to scaling these processes to any number of patients enrolled onto large clinical trials.

  9. Electronic theses and dissertations: a review of this valuable resource for nurse scholars worldwide.

    Science.gov (United States)

    Goodfellow, L M

    2009-06-01

    A worldwide repository of electronic theses and dissertations (ETDs) could provide worldwide access to the most up-to-date research generated by masters and doctoral students. Until that international repository is established, it is possible to access some of these valuable knowledge resources. ETDs provide a technologically advanced medium with endless multimedia capabilities that far exceed the print and bound copies of theses and dissertations housed traditionally in individual university libraries. CURRENT USE: A growing trend exists for universities worldwide to require graduate students to submit theses or dissertations as electronic documents. However, nurse scholars underutilize ETDs, as evidenced by perusing bibliographic citation lists in many of the research journals. ETDs can be searched for and retrieved through several digital resources such as the Networked Digital Library of Theses and Dissertations (http://www.ndltd.org), ProQuest Dissertations and Theses (http://www.umi.com), the Australasian Digital Theses Program (http://adt.caul.edu.au/) and through individual university web sites and online catalogues. An international repository of ETDs benefits the community of nurse scholars in many ways. The ability to access recent graduate students' research electronically from anywhere in the world is advantageous. For scholars residing in developing countries, access to these ETDs may prove to be even more valuable. In some cases, ETDs are not available for worldwide access and can only be accessed through the university library from which the student graduated. Public access to university library ETD collections is not always permitted. Nurse scholars from both developing and developed countries could benefit from ETDs.

  10. From Millennium ERM to Proquest 360 Resource Manager: Implementing a new Electronic Resources Management System ERMS in an International Graduate Research University in Saudi Arabia

    KAUST Repository

    Ramli, Rindra M.

    2017-05-17

    An overview of the Recommendation Study and the subsequent Implementation of a new Electronic Resources Management system ERMS in an international graduate research university in the Kingdom of Saudi Arabia. It covers the timeline, deliverables and challenges as well as lessons learnt by the Project Team.

  11. Carbon and nitrogen dynamics across a bedrock-regulated subarctic pH gradient

    Science.gov (United States)

    Tomczyk, N.; Heim, E. W.; Sadowsky, J.; Remiszewski, K.; Varner, R. K.; Bryce, J. G.; Frey, S. D.

    2014-12-01

    Bedrock geochemistry has been shown to influence landscape evolution due to nutrient limitation on primary production. There may also be less direct interactions between bedrock-derived chemicals and ecosystem function. Effects of calcium (Ca) and pH on soil carbon (C) and nitrogen (N) cycling have been shown in acid impacted forests o f North America. Understanding intrinsic factors that affect C and nutrient dynamics in subarctic ecosystems has implications for how these ecosystems will respond to a changing climate. How the soil microbial community allocates enzymes to acquire resources from the environment can indicate whether a system is nutrient or energy limited. This study examined whether bedrock geochemistry exerts pressure on nutrient cycles in the overlying soils. In thin, weakly developed soils, bedrock is the primary mineral material and is a source of vital nutrients. Nitrogen (N) and C are not derived from bedrock, but their cycling is still affected by reactions with geologically-derived chemicals. Our study sites near Abisko, Sweden (~68°N) were selected adjacent to five distinct bedrock outcrops (quartzite, slate, carbonate, and two different metasedimenty units). All sites were at a similar elevation (~700 m a.s.l.) and had similar vegetation (subarctic heath). Nutrient concentrations in bedrock and soils were measured in addition to soil microbial biomass and extracellular enzyme activity. We found a statistically significant correlation between soil Ca concentrations and soil pH (r = 0.88, p pH and the ratio of C-acquiring to N-acquiring enzyme activity (r = -0.89, p pH and soil C-to-N ratio (r = -0.76, p enzyme activity and soil C-to-N ratio (r = 0.78, p effect on soil pH.

  12. DEVELOPMENT AND USAGE OF THE ELECTRONIC VIDEO RESOURCES FOR EDUCATIONAL PURPOSES

    Directory of Open Access Journals (Sweden)

    Yaroslav M. Hlynsky

    2017-04-01

    Full Text Available This article discusses the theoretical foundation, the creation and implementation of the electronic educational video resources (EEVR in the example of the development and the usage of the collection of video tutorials in event-driven programming theme, which is studied in the framework of the subject "Informatics" by students of many specialties. It offers some development of the existing conceptual and categorical apparatus concerning EEVR development. It is alleged that the video tutorials allow you to automate the process of learning, redistribute instructional time for the benefit of students' independent work, to provide classroom release time for the teaching of the theoretical issues of the course that is aimed at improving the fundamental nature of training. Practical recommendations for the development of the effective EEVR, which may be useful for the authors of e-learning courses for students of different forms of training are proposed.

  13. [HYGIENIC REGULATION OF THE USE OF ELECTRONIC EDUCATIONAL RESOURCES IN THE MODERN SCHOOL].

    Science.gov (United States)

    Stepanova, M I; Aleksandrova, I E; Sazanyuk, Z I; Voronova, B Z; Lashneva, L P; Shumkova, T V; Berezina, N O

    2015-01-01

    We studied the effect of academic studies with the use a notebook computer and interactive whiteboard on the functional state of an organism of schoolchildren. Using a complex of hygienic and physiological methods of the study we established that regulation of the computer activity of students must take into account not only duration but its intensity either. Design features of a notebook computer were shown both to impede keeping the optimal working posture in primary school children and increase the risk offormation of disorders of vision and musculoskeletal system. There were established the activating influence of the interactive whiteboard on performance activities and favorable dynamics of indices of the functional state of the organism of students under keeping optimal density of the academic study and the duration of its use. There are determined safety regulations of the work of schoolchildren with electronic resources in the educational process.

  14. Availability, Use and Constraints to Use of Electronic Information Resources by Postgraduates Students at the University of Ibadan

    Directory of Open Access Journals (Sweden)

    Dare Samuel Adeleke

    2017-12-01

    Full Text Available Availability, awareness and use of electronic resources provide access to authoritative, reliable, accurate and timely access to information. The use of electronic information resources (EIRs can enable innovation in teaching and increase timeliness in research of postgraduate students which will eventual result into encouragement of the expected research-led enquiry in this digital age. The study adopted a descriptive survey design. Samples of 300 of postgraduate students within seven out 13 Faculties were randomly selected. Data were collected using questionnaire designed to elicit response from respondents and data were analyzed using descriptive statistics methods percentages, mean, and standard deviation. Results indicated that internet was ranked most available and used in the university. Low level of usage of electronic resources, in particular, full texts data bases is linked to a number of constraints: Interrupted power supply was ranked highest among other factors as speed and capacity of computers, retrieval of records with high recall and low precision, retrieving records relevant to information need, lack of knowledge of search techniques to retrieve information effectively, non possession of requisite IT skills and problems accessing the internet. The study recommended that usage of electronic resources be made compulsory, intensifying awareness campaigns concerning the availability, training on use of electronic resources and the problem of power outage be addressed.

  15. Factors Influencing Students' Use of Electronic Resources and their Opinions About this Use: The Case of Students at An-Najah National University

    Directory of Open Access Journals (Sweden)

    Wajeeh M. Daher

    2010-12-01

    Full Text Available Electronic resources are becoming an integral part of the modern life and of the educational scene, especially the high education scene. In this research we wanted to verify what influences first degree university students' use of electronic resources and their opinions regarding this use. Collecting data from 202 students and analyzing it using SPSS, we found that more than one half of the participants had high level of electronic media use and more than one third had moderate level of electronic media use. These levels of use indicate the students' awareness of the role and benefits of electronic media use. Regarding the factors that influence the students' se of electronic resources we found that the student's use of electronic resources had significant strong positive relationships with the provision of electronic resources by the academic institution. It had significant moderate positive relationships with the resources characteristics and the course requirement, and had significant weak relationships with the instructor's support and the student's characteristics. We explained these relationships as resulting from the influence of the surrounding community. Regarding the students' opinions about the use of electronic resources, we found that the student's opinion of electronic resources has significant strong positive relationships with student's use of electronic resources, level of this use, the academic institution available facilities, student's characteristics and resources characteristics. It does not have significant relationships with the instructor's support or the course requirement. We explained these relationships depending on activity theory and its integration with ecological psychology.

  16. SAGES: a suite of freely-available software tools for electronic disease surveillance in resource-limited settings.

    Directory of Open Access Journals (Sweden)

    Sheri L Lewis

    Full Text Available Public health surveillance is undergoing a revolution driven by advances in the field of information technology. Many countries have experienced vast improvements in the collection, ingestion, analysis, visualization, and dissemination of public health data. Resource-limited countries have lagged behind due to challenges in information technology infrastructure, public health resources, and the costs of proprietary software. The Suite for Automated Global Electronic bioSurveillance (SAGES is a collection of modular, flexible, freely-available software tools for electronic disease surveillance in resource-limited settings. One or more SAGES tools may be used in concert with existing surveillance applications or the SAGES tools may be used en masse for an end-to-end biosurveillance capability. This flexibility allows for the development of an inexpensive, customized, and sustainable disease surveillance system. The ability to rapidly assess anomalous disease activity may lead to more efficient use of limited resources and better compliance with World Health Organization International Health Regulations.

  17. SAGES: A Suite of Freely-Available Software Tools for Electronic Disease Surveillance in Resource-Limited Settings

    Science.gov (United States)

    Lewis, Sheri L.; Feighner, Brian H.; Loschen, Wayne A.; Wojcik, Richard A.; Skora, Joseph F.; Coberly, Jacqueline S.; Blazes, David L.

    2011-01-01

    Public health surveillance is undergoing a revolution driven by advances in the field of information technology. Many countries have experienced vast improvements in the collection, ingestion, analysis, visualization, and dissemination of public health data. Resource-limited countries have lagged behind due to challenges in information technology infrastructure, public health resources, and the costs of proprietary software. The Suite for Automated Global Electronic bioSurveillance (SAGES) is a collection of modular, flexible, freely-available software tools for electronic disease surveillance in resource-limited settings. One or more SAGES tools may be used in concert with existing surveillance applications or the SAGES tools may be used en masse for an end-to-end biosurveillance capability. This flexibility allows for the development of an inexpensive, customized, and sustainable disease surveillance system. The ability to rapidly assess anomalous disease activity may lead to more efficient use of limited resources and better compliance with World Health Organization International Health Regulations. PMID:21572957

  18. Theoretical Aspects of the Use of Electronic Educational Resources in Professional Activity of Future Teachers of Technology

    OpenAIRE

    Iryna Smyrnova

    2017-01-01

    In this paper, we tried to determine the requirements for ESM, to study theoretical aspects of electronic educational resources in the professional activity of future teachers. The results created by the introduction of our course “Methodology development and use of electronic educational resources” for future teachers of technology ITOS in the process of professional specialty “Technology” in the educational process of higher educational institutions of Ukraine. The article states the rapid ...

  19. Systematically enhanced subarctic Pacific stratification and nutrient utilization during glacials

    Science.gov (United States)

    Knudson, K. P.; Ravelo, A. C.

    2015-12-01

    The modern subarctic North Pacific is characterized as a high-nitrate, low-chlorophyll (HNLC) area, but evidence for increased nutrient utilization during the last glacial indicates that this region is highly dynamic. As such, this HNLC area is of particular interest in regard to understanding changes in the biological pump and carbon sequestration and predicting how biogeochemical processes will influence, or be influenced by, future climate change. While it has been suggested that changes in iron supply and/or ocean stratification could explain fluctuations in nutrient utilization and productivity in the subarctic Pacific, short records of nutrient utilization have previously hindered the evaluation of these potential mechanisms over long timescales. Here we present new, high-resolution records of bulk sediment δ15N from 0-1.2 Ma from Integrated Ocean Drilling Program Exp. 323 Site U1342, which are used to calculate Δδ15N (U1342 δ15Nbulk - ODP Site 1012 δ15Nbulk) as a nitrate utilization proxy. The unprecedented length and resolution of this new record allows us, for the first time, to determine orbital-scale systematic behavior in subarctic Pacific nutrient utilization over many glacial/interglacial cycles. Spectral analyses demonstrate that enhanced nutrient utilization was paced by climate on Milankovitch orbital cycles since the Mid-Pleistocene Transition (MPT; ~800 ka). Nitrate utilization maxima is statistically correlated with glacial maxima and enhanced dust/iron availability (represented by existing records of EPICA ice core dust, Southern Pacific Ocean sediment iron, and China loess) but shows low correlation to primary productivity, suggesting that stratification has systematically exerted an important control on subarctic Pacific nutrient utilization since the MPT. These findings imply that the presence of iron helped to change the region into a nitrate-limited, rather than iron-limited, region during glacials and that stratification, which

  20. Resources.

    Science.gov (United States)

    Stewart, John; MacDonald, Ian

    1980-01-01

    Presents a guide to resources on television drama available to teachers for classroom use in television curriculum. Lists American and British television drama videorecordings of both series and individual presentations and offers a bibliography of "one-off" single fiction plays produced for British television. (JMF)

  1. Uncertainty in the impacts of projected climate change on the hydrology of a subarctic environment: Liard River Basin

    Directory of Open Access Journals (Sweden)

    R. Thorne

    2011-05-01

    Full Text Available Like many high latitude areas, the mountainous region of subarctic Canada has experienced recent warming and is an area of large inter-annual temperature variations, most notably during the winter. Quantifying how climate tendencies affect streamflow, especially in the spring melt season, is critical not only to regional water resource management, but to understanding the influence of freshwater on the Arctic sea-ice cover and global climate system. The impact of projected atmospheric warming on the discharge of the Liard River is unclear. Here, uncertainty in climate projections associated with GCM structure (2 °C prescribed warming and magnitude of increases in global mean air temperature (1 to 6 °C on the river discharge are assessed using a well-tested, semi-distributed hydrological model. Analyses have shown that the hydrological impacts are highly dependant on the GCM scenario. Uncertainties between the GCM scenarios are driven by the inconsistencies in projected spatial variability and magnitude of precipitation, rather than warming temperatures. Despite these uncertainties, the entire scenario simulations project that the subarctic nival regime will be preserved in the future, but the magnitude of change in river discharge is highly uncertain. Generally, spring freshet will arrive earlier, autumn to spring discharge will increase whereas summer flow will decrease, leading to an overall increase in annual discharge.

  2. Impact of Electronic Resources and Usage in Academic Libraries in Ghana: Evidence from Koforidua Polytechnic & All Nations University College, Ghana

    Science.gov (United States)

    Akussah, Maxwell; Asante, Edward; Adu-Sarkodee, Rosemary

    2015-01-01

    The study investigates the relationship between impact of electronic resources and its usage in academic libraries in Ghana: evidence from Koforidua Polytechnic & All Nations University College, Ghana. The study was a quantitative approach using questionnaire to gather data and information. A valid response rate of 58.5% was assumed. SPSS…

  3. Utilization of Electronic Information Resources by Undergraduate Students of University of Ibadan: A Case Study of Social Sciences and Education

    Science.gov (United States)

    Owolabi, Sola; Idowu, Oluwafemi A.; Okocha, Foluke; Ogundare, Atinuke Omotayo

    2016-01-01

    The study evaluated utilization of electronic information resources by undergraduates in the Faculties of Education and the Social Sciences in University of Ibadan. The study adopted a descriptive survey design with a study population of 1872 undergraduates in the Faculties of Education and the Social Sciences in University of Ibadan, from which a…

  4. True Serials: A True Solution for Electronic Resource Management Needs in a Medium-Size Academic Library

    Science.gov (United States)

    Milczarski, Vivian; Garofalo, Denise A.

    2011-01-01

    A desire for more functionality seemed to clash with the fiscal reality of limited funds, but after investigating alternatives, Mount Saint Mary College was able to provide its faculty and students with a more useful and function-rich electronic resource management through a move to a hosted open source service. (Contains 8 figures.)

  5. Subarctic warming: Results from the global treeline project

    Energy Technology Data Exchange (ETDEWEB)

    Siren, G.; Shen, S.

    1996-12-31

    The authors reported last year at the 6th Global Warming Science and Policy Conference (GW6), April 3--6, 1995, San Francisco USA, the Global Treeline Project (BLECSCO) has definitively established the northward movement in the 20th century of the northernmost limit for pine trees in Finland. this movement is due to climate warming. The Finnish Forest Research Institute has been working on this problem between 1951 and 1996. The authors have observed over half a century the movements of the coniferous treeline. The subarctic pine tree line is used as a permanent bioindicator of climate change. The dynamic pine tree line in the subarctic of Finland serves as a reliable indicator of expected climate change in the future as well as of climatic fluctuations in the past. The FFRI has tracked comprehensively seed year frequencies, performed dendrochronological studies, fire studies, and ecological studies since the abundant seed year of 1948--50 to the present, and discovered that climate change has favored the northward movement of the pine limit. The authors report the detailed scientific methodology, data, and conclusions.

  6. Residency times and patterns of movement of postbreeding dunlin on a subarctic staging area in Alaska

    Science.gov (United States)

    Warnock, Nils; Handel, Colleen M.; Gill, Robert E.; McCaffery, Brian J.

    2013-01-01

    Understanding how individuals use key resources is critical for effective conservation of a population. The Yukon-Kuskokwim Delta (YKD) in western Alaska is the most important postbreeding staging area for shorebirds in the subarctic North Pacific, yet little is known about movements of shorebirds there during the postbreeding period. To address this information gap, we studied residency times and patterns of movement of 17 adult and 17 juvenile radio-marked Dunlin (Calidris alpina) on the YKD between early August and early October 2005. Throughout this postbreeding period, during which Dunlin were molting, most birds were relocated within a 130 km radius of their capture site on the YKD, but three birds were relocated more than 600 km to the south at estuaries along the Alaska Peninsula. On average, juvenile Dunlin were relocated farther away from the banding site (median relocation distance = 36.3 km) than adult Dunlin (median relocation distance = 8.8 km). Post-capture, minimum lengths of stay by Dunlin on the YKD were not significantly different between juveniles (median = 19 days) and adults (median = 23 days), with some birds staging for more than 50 days. Body mass at time of capture was the best single variable explaining length of stay on the YKD, with average length of stay decreasing by 2.5 days per additional gram of body mass at time of capture. Conservation efforts for postbreeding shorebirds should consider patterns of resource use that may differ not only by age cohort but also by individual condition.

  7. The Use of Electronic Resources by Academic Staff at the University of Ilorin, Nigeria

    Science.gov (United States)

    Tella, Adeyinka; Orim, Faith; Ibrahim, Dauda Morenikeji; Memudu, Suleiman Ajala

    2018-01-01

    The use of e-resources is now commonplace among academics in tertiary educational institutions the world over. Many academics including those in the universities are exploring the opportunities of e-resources to facilitate teaching and research. As the use of e-resources is increasing particularly among academics at the University of Ilorin,…

  8. Novel open-source electronic medical records system for palliative care in low-resource settings.

    Science.gov (United States)

    Shah, Kamal G; Slough, Tara Lyn; Yeh, Ping Teresa; Gombwa, Suave; Kiromera, Athanase; Oden, Z Maria; Richards-Kortum, Rebecca R

    2013-08-14

    The need for palliative care in sub-Saharan Africa is staggering: this region shoulders over 67% of the global burden of HIV/AIDS and cancer. However, provisions for these essential services remain limited and poorly integrated with national health systems in most nations. Moreover, the evidence base for palliative care in the region remains scarce. This study chronicles the development and evaluation of DataPall, an open-source electronic medical records system that can be used to track patients, manage data, and generate reports for palliative care providers in these settings.DataPall was developed using design criteria encompassing both functional and technical objectives articulated by hospital leaders and palliative care staff at a leading palliative care center in Malawi. The database can be used with computers that run Windows XP SP 2 or newer, and does not require an internet connection for use. Subsequent to its development and implementation in two hospitals, DataPall was tested among both trained and untrained hospital staff populations on the basis of its usability with comparison to existing paper records systems as well as on the speed at which users could perform basic database functions. Additionally, all participants evaluated this program on a standard system usability scale. In a study of health professionals in a Malawian hospital, DataPall enabled palliative care providers to find patients' appointments, on average, in less than half the time required to locate the same record in current paper records. Moreover, participants generated customizable reports documenting patient records and comprehensive reports on providers' activities with little training necessary. Participants affirmed this ease of use on the system usability scale. DataPall is a simple, effective electronic medical records system that can assist in developing an evidence base of clinical data for palliative care in low resource settings. The system is available at no cost, is

  9. Human resource requirements for quality-assured electronic data capture of the tuberculosis case register

    Directory of Open Access Journals (Sweden)

    Hoa Nguyen B

    2012-01-01

    Full Text Available Abstract Background The tuberculosis case register is the data source for the reports submitted by basic management units to the national tuberculosis program. Our objective was to measure the data entry time required to complete and double-enter one record, and to estimate the time for the correction of errors in the captured information from tuberculosis case registers in Cambodia and Viet Nam. This should assist in quantifying the additional requirements in human resources for national programs moving towards electronic recording and reporting. Methods Data from a representative sample of tuberculosis case registers from Cambodia and Viet Nam were double-entered and discordances resolved by rechecking the original case register. Computer-generated data entry time recorded the time elapsed between opening of a new record and saving it to disk. Results The dataset comprised 22,732 double-entered records of 11,366 patients (37.1% from Cambodia and 62.9% from Viet Nam. The mean data entry times per record were 97.5 (95% CI: 96.2-98.8 and 66.2 (95% CI: 59.5-73.0 seconds with medians of 90 and 31 s respectively in Cambodia and in Viet Nam. The percentage of records with an error was 6.0% and 39.0% respectively in Cambodia and Viet Nam. Data entry time was inversely associated with error frequency. We estimate that approximately 118-person-hours were required to produce 1,000 validated records. Conclusions This study quantifies differences between two countries for data entry time for the tuberculosis case register and frequencies of data entry errors and suggests that higher data entry speed is partially offset by requiring revisiting more records for corrections.

  10. Use and Cost of Electronic Resources in Central Library of Ferdowsi University Based on E-metrics

    Directory of Open Access Journals (Sweden)

    Mohammad Reza Davarpanah

    2012-07-01

    Full Text Available The purpose of this study was to investigate the usage of electronic journals in Ferdowsi University, Iran based on e-metrics. The paper also aimed to emphasize the analysis of cost-benefit and the correlation between the journal impact factors and the usage data. In this study experiences of Ferdowsi University library on licensing and usage of electronic resources was evaluated by providing a cost-benefit analysis based on the cost and usage statistics of electronic resources. Vendor-provided data were also compared with local usage data. The usage data were collected by tracking web-based access locally, and by collecting vender-provided usage data. The data sources were one-year of vendor-supplied e-resource usage data such as Ebsco, Elsevier, Proquest, Emerald, Oxford and Springer and local usage data collected from the Ferdowsi university web server. The study found that actual usage values differ for vendor-provided data and local usage data. Elsevier has got the highest usage degree in searches, sessions and downloads. Statistics also showed that a small number of journals satisfy significant amount of use while the majority of journals were used less frequent and some were never used at all. The users preferred the PDF rather than HTML format. The data in subject profile suggested that the provided e-resources were best suited to certain subjects. There was no correlation between IF and electronic journal use. Monitoring the usage of e-resources gained increasing importance for acquisition policy and budget decisions. The article provided information about local metrics for the six surveyed vendors/publishers, e.g. usage trends, requests per package, cost per use as related to the scientific specialty of the university.

  11. Collembola at three alpine subarctic sites resistant to twenty years of experimental warming

    Czech Academy of Sciences Publication Activity Database

    Alatalo, J.M.; Jägerbrand, A.K.; Čuchta, Peter

    2015-01-01

    Roč. 5, December (2015), s. 18161 ISSN 2045-2322 Institutional support: RVO:60077344 Keywords : Collembola * alpine subarctic sites * experimental warming Subject RIV: EH - Ecology, Behaviour Impact factor: 5.228, year: 2015

  12. Enzymology under global change: organic nitrogen turnover in alpine and sub-Arctic soils

    NARCIS (Netherlands)

    Weedon, J.T.; Aerts, R.; Kowalchuk, G.A.; van Bodegom, P.M.

    2011-01-01

    Understanding global change impacts on the globally important carbon storage in alpine, Arctic and sub-Arctic soils requires knowledge of the mechanisms underlying the balance between plant primary productivity and decomposition. Given that nitrogen availability limits both processes, understanding

  13. Enzymology under global change: organic nitrogen turnover in alpine and sub-Arctic soils.

    NARCIS (Netherlands)

    Weedon, J.T.; Aerts, R.; Kowalchuk, G.A.; van Bodegom, P.M.

    2011-01-01

    Understanding global change impacts on the globally important carbon storage in alpine, Arctic and sub-Arctic soils requires knowledge of the mechanisms underlying the balance between plant primary productivity and decomposition. Given that nitrogen availability limits both processes, understanding

  14. Optimal sleep duration in the subarctic with respect to obesity risk is 8-9 hours

    National Research Council Canada - National Science Library

    Johnsen, May Trude; Wynn, Rolf; Bratlid, Trond

    2013-01-01

    ...) and abdominal obesity. The optimal sleep duration regarding BMI has previously been found to be 7-8 hours, but these studies have not been carried out in the subarctic or have lacked some central variables...

  15. Energy Design Guidelines for High Performance Schools: Arctic and Subarctic Climates

    Energy Technology Data Exchange (ETDEWEB)

    2004-11-01

    The Energy Design Guidelines for High Performance Schools--Arctic and Subarctic Climates provides school boards, administrators, and design staff with guidance to help them make informed decisions about energy and environmental issues important to school systems and communities. These design guidelines outline high performance principles for the new or retrofit design of your K-12 school in arctic and subarctic climates. By incorporating energy improvements into their construction or renovation plans, schools can significantly reduce energy consumption and costs.

  16. Probable limits of sea ice extent in the northwestern Subarctic Pacific during the last glacial maximum

    Science.gov (United States)

    Matul, A. G.

    2017-09-01

    The article summarizes and analyzes published data on the distribution of sea-ice and open-ocean diatoms in 42 cores of bottom sediments from the northwestern part of the Subarctic Pacific that accumulated during the last glacial maximum (LGM). Based on micropaleontological records, the extent of winter sea ice during the LGM could be limited to the Okhotsk and Bering seas. During the warm season, the surface water masses from the open Subarctic Pacific spread widely in the marginal seas.

  17. Optimal Sleep Duration in the Subarctic with Respect to Obesity Risk Is 8?9 Hours

    OpenAIRE

    May Trude Johnsen; Rolf Wynn; Trond Bratlid

    2013-01-01

    INTRODUCTION: Sleep duration, chronotype and social jetlag have been associated with body mass index (BMI) and abdominal obesity. The optimal sleep duration regarding BMI has previously been found to be 7-8 hours, but these studies have not been carried out in the subarctic or have lacked some central variables. The aims of our study were to examine the associations between sleep variables and body composition for people living in the subarctic, taking a range of variables into consideration,...

  18. Effective Knowledge Development in Secondary Schools Educational Level in Contemporary Information Age: Assessment of Availability of Electronic Information Resources in Nigerian School Libraries

    Science.gov (United States)

    Bello, Stephen Adeyemi; Ojo, Funmilayo Roseline; Ocheje, Charles Bala

    2015-01-01

    Relevant electronic information resources in contemporary information age are necessity to buttress teaching and learning for effective knowledge development in educational institutions. The purpose of the study is to know the state of availability of electronic information resources in government owned secondary school libraries in Ijumu Local…

  19. Fluxes of Methane and Carbon Dioxide from a Subarctic Lake

    DEFF Research Database (Denmark)

    Jammet, Mathilde Manon

    important for the lake annual emissions compared to the length of the period, as it turned the lake from a small summer CO2 sink into an annual source. Annual inter-annual variability was notable in the magnitude of the CH4 spring release and needs further investigation. The high temporal resolution......-out and the release of CH4 and CO2 was established. These results underline the crucial importance of shoulder seasons in the annual carbon emissions from seasonally frozen lakes. Overall, the lake was an important annual source of carbon to the atmosphere, partially compensating the higher, annual sink function......Ongoing climate warming is expected to affect the carbon functioning of subarctic ecosystems. Lakes and wetlands, which are common ecosystems of the high northern latitudes, are of utmost interest in this context because they exchange large amounts of the climate-forcing gases methane (CH4...

  20. Phytoremediation of subarctic soil contaminated with diesel fuel

    Energy Technology Data Exchange (ETDEWEB)

    Palmroth, M.R.T.; Puhakka, J.A. [Tampere University of Technology (Finland). Institute of Environmental Engineering and Biotechnology; Pichtel, J. [Ball State University, Muncie, IN (United States). Natural Resources and Environmental Management

    2002-09-01

    The effects of several plant species, native to northern latitudes, and different soil amendments, on diesel fuel removal from soil were studied. Plant treatments included Scots Pine (Pinus sylvestris), Poplar (Populus deltoides x Wettsteinii), a grass mixture (Red fescue, Festuca rubra; Smooth meadowgrass, Poa pratensis and Perennial ryegrass, Lolium perenne) and a legume mixture (White clover, Trifolium repens and Pea, Pisum sativum). Soil amendments included NPK fertiliser, a compost extract and a microbial enrichment culture. Diesel fuel disappeared more rapidly in the legume treatment than in other plant treatments. The presence of poplar and pine enhanced removal of diesel fuel, but removal under grass was similar to that with no vegetation. Soil amendments did not enhance diesel fuel removal significantly. Grass roots accumulated diesel-range compounds. This study showed that utilisation of selected plants accelerates removal of diesel fuel in soil and may serve as a viable, low-cost remedial technology for diesel-contaminated soils in subarctic regions. (author)

  1. Glacierized headwater streams as aquifer recharge corridors, subarctic Alaska

    Science.gov (United States)

    Liljedahl, A. K.; Gädeke, A.; O'Neel, S.; Gatesman, T. A.; Douglas, T. A.

    2017-07-01

    Arctic river discharge has increased in recent decades although sources and mechanisms remain debated. Abundant literature documents permafrost thaw and mountain glacier shrinkage over the past decades. Here we link glacier runoff to aquifer recharge via a losing headwater stream in subarctic Interior Alaska. Field measurements in Jarvis Creek (634 km2), a subbasin of the Tanana and Yukon Rivers, show glacier meltwater runoff as a large component (15-28%) of total annual streamflow despite low glacier cover (3%). About half of annual headwater streamflow is lost to the aquifer (38 to 56%). The estimated long-term change in glacier-derived aquifer recharge exceeds the observed increase in Tanana River base flow. Our findings suggest a linkage between glacier wastage, aquifer recharge along the headwater stream corridor, and lowland winter discharge. Accordingly, glacierized headwater streambeds may serve as major aquifer recharge zones in semiarid climates and therefore contributing to year-round base flow of lowland rivers.

  2. Glacierized headwater streams as aquifer recharge corridors, subarctic Alaska

    Science.gov (United States)

    Lilledahl, Anna K.; Gadeke, Anne; O'Neel, Shad; Gatesman, T. A.; Douglas, T. A.

    2017-01-01

    Arctic river discharge has increased in recent decades although sources and mechanisms remain debated. Abundant literature documents permafrost thaw and mountain glacier shrinkage over the past decades. Here we link glacier runoff to aquifer recharge via a losing headwater stream in subarctic Interior Alaska. Field measurements in Jarvis Creek (634 km2), a subbasin of the Tanana and Yukon Rivers, show glacier meltwater runoff as a large component (15–28%) of total annual streamflow despite low glacier cover (3%). About half of annual headwater streamflow is lost to the aquifer (38 to 56%). The estimated long-term change in glacier-derived aquifer recharge exceeds the observed increase in Tanana River base flow. Our findings suggest a linkage between glacier wastage, aquifer recharge along the headwater stream corridor, and lowland winter discharge. Accordingly, glacierized headwater streambeds may serve as major aquifer recharge zones in semiarid climates and therefore contributing to year-round base flow of lowland rivers.

  3. Nitrogen Uptake During Fall, Winter and Spring Differs Among Plant Functional Groups in a Subarctic Heath Ecosystem

    DEFF Research Database (Denmark)

    Larsen, Klaus Steenberg; Michelsen, Anders; Jonasson, Sven

    2012-01-01

    Nitrogen (N) is a critical resource for plant growth in tundra ecosystems, and species differences in the timing of N uptake may be an important feature regulating community composition and ecosystem productivity. We added 15N-labelled glycine to a subarctic heath tundra dominated by dwarf shrubs......, mosses and graminoids in fall, and investigated its partitioning among ecosystem components at several time points (October, November, April, May, June) through to the following spring/early summer. Soil microbes had acquired 65 ± 7% of the 15N tracer by October, but this pool decreased through winter....... The faster-growing deciduous shrubs did not resume 15N acquisition until after early May indicating that they relied more on nitrogen made available later during the spring/early summer. The graminoids and mosses had no significant increases in 15N tracer recovery or tissue 15N tracer concentrations after...

  4. Europeanization of sub-Arctic environments: soils based evidence from Norse Greenland

    Science.gov (United States)

    Simpson, Ian; Collinge, Kirsty; Adderley, Paul; Wilson, Clare

    2014-05-01

    Europeanization of sub-Arctic environments by Norse communities in Greenland from the early 11th to mid 15th centuries AD varied spatially and temporally, with pastoral agriculture and associated homefield management at the heart of this transformation. This process is poorly understood and so from inner, middle and outer fjord areas of the Norse Eastern settlement in Greenland we contribute a chronologically constrained homefield soils and sediments-based historical ecodynamic analysis. Our findings demonstrate a range of homefield management activities in contrasting environmental and social settings including a) 'recipe effects' - the partitioning of turf, domestic animal manure and domestic waste resources used to manage soil fertility and the effects of eroded material deposition in the homefield; b) field irrigation management to overcome seasonal water limitations; and c) 'non-management' where homefield productivities relied on natural soil fertilities. These management practices created an anthrosols soil environment overlying and distinct from the podsolic environment at settlement. In doing so Norse settlers increased soil nutrient status relative to pre-settlement levels in some homefields, whilst nutrient levels in other areas of the homefield were allowed to decline, resulting in a situation of 'partial sustainability'. We demonstrate that in historical contexts, local 'partial sustainability' can lead to resilience amongst agricultural communities in the face of climatic deterioration, but that ultimately this may only be as effective as the broader social framework in which it is found.

  5. Challenges in the implementation of an electronic surveillance system in a resource-limited setting: Alerta, in Peru

    Directory of Open Access Journals (Sweden)

    Soto Giselle

    2008-11-01

    Full Text Available Abstract Background Infectious disease surveillance is a primary public health function in resource-limited settings. In 2003, an electronic disease surveillance system (Alerta was established in the Peruvian Navy with support from the U.S. Naval Medical Research Center Detachment (NMRCD. Many challenges arose during the implementation process, and a variety of solutions were applied. The purpose of this paper is to identify and discuss these issues. Methods This is a retrospective description of the Alerta implementation. After a thoughtful evaluation according to the Centers for Disease Control and Prevention (CDC guidelines, the main challenges to implementation were identified and solutions were devised in the context of a resource-limited setting, Peru. Results After four years of operation, we have identified a number of challenges in implementing and operating this electronic disease surveillance system. These can be divided into the following categories: (1 issues with personnel and stakeholders; (2 issues with resources in a developing setting; (3 issues with processes involved in the collection of data and operation of the system; and (4 issues with organization at the central hub. Some of the challenges are unique to resource-limited settings, but many are applicable for any surveillance system. For each of these challenges, we developed feasible solutions that are discussed. Conclusion There are many challenges to overcome when implementing an electronic disease surveillance system, not only related to technology issues. A comprehensive approach is required for success, including: technical support, personnel management, effective training, and cultural sensitivity in order to assure the effective deployment of an electronic disease surveillance system.

  6. RESEARCH OF INFLUENCE OF QUALITY OF ELECTRONIC EDUCATIONAL RESOURCES ON QUALITY OF TRAINING WITH USE OF DISTANCE TECHNOLOGIES

    Directory of Open Access Journals (Sweden)

    H. M. Kravtsov

    2013-03-01

    Full Text Available Communication improving of educational processes requires today new approaches to the management arrangements and forming of educational policy in the field of distance learning, which is based on the use of modern information and communication technologies. An important step in this process is the continuous monitoring of the development and implementation of information technology and, in particular, the distance learning systems in higher educational establishments. The main objective of the monitoring is the impact assessment on the development of distance learning following the state educational standards, curricula, methodical and technical equipment and other factors; factors revelation that influence the implementation and outcomes of distance learning; results comparison of educational institution functioning and distance education systems in order to determine the most efficient ways of its development. The paper presents the analysis results of the dependence of the quality of educational services on the electronic educational resources. Trends in educational services development was studied by comparing the quality influence of electronic educational resources on the quality of educational services of higher pedagogical educational institutions of Ukraine as of 2009-2010 and 2012-2013. Generally, the analysis of the survey results allows evaluating quality of the modern education services as satisfactory and it can be said that almost 70% of the success of their future development depends on the quality of the used electronic educational resources and distance learning systems in particular.

  7. Tracking the Flow of Resources in Electronic Waste - The Case of End-of-Life Computer Hard Disk Drives.

    Science.gov (United States)

    Habib, Komal; Parajuly, Keshav; Wenzel, Henrik

    2015-10-20

    Recovery of resources, in particular, metals, from waste flows is widely seen as a prioritized option to reduce their potential supply constraints in the future. The current waste electrical and electronic equipment (WEEE) treatment system is more focused on bulk metals, where the recycling rate of specialty metals, such as rare earths, is negligible compared to their increasing use in modern products, such as electronics. This study investigates the challenges in recovering these resources in the existing WEEE treatment system. It is illustrated by following the material flows of resources in a conventional WEEE treatment plant in Denmark. Computer hard disk drives (HDDs) containing neodymium-iron-boron (NdFeB) magnets were selected as the case product for this experiment. The resulting output fractions were tracked until their final treatment in order to estimate the recovery potential of rare earth elements (REEs) and other resources contained in HDDs. The results further show that out of the 244 kg of HDDs treated, 212 kg comprising mainly of aluminum and steel can be finally recovered from the metallurgic process. The results further demonstrate the complete loss of REEs in the existing shredding-based WEEE treatment processes. Dismantling and separate processing of NdFeB magnets from their end-use products can be a more preferred option over shredding. However, it remains a technological and logistic challenge for the existing system.

  8. HELP (INFORMATION ELECTRONIC RESOURCE "CHRONICLE OF ONU: DATES, FACTS, EVENTS": HISTORY OF UNIVERSITY IN INFORMATION SPACE

    Directory of Open Access Journals (Sweden)

    А. М. Гавриленко

    2016-03-01

    Object of research is the help information resource "The chronicle of the Odessa national university of I. I. Mechnikov: dates, facts, events". The main objective of our article – to state the main methodological bases of creation of information resource. One of advantages of information resource is possibility of continuous updating and replenishment by new information. Main objective of creation of this information resource is systematization of material on stories of the Odessa national university of I. I. Mechnikov from the date of his basis to the present, ensuring interactive access to information on the main dates, the most significant events in life of university. The base of research are sources on the history of university, chronology of historical development, formation of infrastructure, cadres and scientific researches. In information resource the main stages of development, functioning and transformation of the Odessa University are analyzed, information on its divisions is collected. For creation of this information resource in Scientific library the method of work was developed, the main selection criteria of data are allocated. This information resource have practical value for all who is interested in history of university, historians, scientists-researchers of history of science and the city of Odessa.

  9. Effect of Access to an Electronic Medical Resource on Performance Characteristics of a Certification Examination: A Randomized Controlled Trial.

    Science.gov (United States)

    Lipner, Rebecca S; Brossman, Bradley G; Samonte, Kelli M; Durning, Steven J

    2017-09-05

    Electronic resources are increasingly used in medical practice. Their use during high-stakes certification examinations has been advocated by many experts, but whether doing so would affect the capacity to differentiate between high and low abilities is unknown. To determine the effect of electronic resources on examination performance characteristics. Randomized controlled trial. Medical certification program. 825 physicians initially certified by the American Board of Internal Medicine (ABIM) who passed the Internal Medicine Certification examination or sat for the Internal Medicine Maintenance of Certification (IM-MOC) examination in 2012 to 2015. Participants were randomly assigned to 1 of 4 conditions: closed book using typical or additional time, or open book (that is, UpToDate [Wolters Kluwer]) using typical or additional time. All participants took the same modified version of the IM-MOC examination. Primary outcomes included item difficulty (how easy or difficult the question was), item discrimination (how well the question differentiated between high and low abilities), and average question response time. Secondary outcomes included examination dimensionality (that is, the number of factors measured) and test-taking strategy. Item response theory was used to calculate question characteristics. Analysis of variance compared differences among conditions. Closed-book conditions took significantly less time than open-book conditions (mean, 79.2 seconds [95% CI, 78.5 to 79.9 seconds] vs. 110.3 seconds [CI, 109.2 to 111.4 seconds] per question). Mean discrimination was statistically significantly higher for open-book conditions (0.34 [CI, 0.32 to 0.35] vs. 0.39 [CI, 0.37 to 0.41] per question). A strong single dimension showed that the examination measured the same factor with or without the resource. Only 1 electronic resource was evaluated. Inclusion of an electronic resource with time constraints did not adversely affect test performance and did not change

  10. Effects of a warmer climate on seed germination in the subarctic

    Science.gov (United States)

    Milbau, Ann; Graae, Bente Jessen; Shevtsova, Anna; Nijs, Ivan

    2009-01-01

    Background and Aims In a future warmer subarctic climate, the soil temperatures experienced by dispersed seeds are likely to increase during summer but may decrease during winter due to expected changes in snow depth, duration and quality. Because little is known about the dormancy-breaking and germination requirements of subarctic species, how warming may influence the timing and level of germination in these species was examined. Methods Under controlled conditions, how colder winter and warmer summer soil temperatures influenced germination was tested in 23 subarctic species. The cold stratification and warm incubation temperatures were derived from real soil temperature measurements in subarctic tundra and the temperatures were gradually changed over time to simulate different months of the year. Key Results Moderate summer warming (+2·5 °C) substantially accelerated germination in all but four species but did not affect germination percentages. Optimum germination temperatures (20/10°C) further decreased germination time and increased germination percentages in three species. Colder winter soil temperatures delayed the germination in ten species and decreased the germination percentage in four species, whereas the opposite was found in Silene acaulis. In most species, the combined effect of a reduced snow cover and summer warming resulted in earlier germination and thus a longer first growing season, which improves the chance of seedling survival. In particular the recruitment of (dwarf) shrubs (Vaccinium myrtillus, V. vitis-idaea, Betula nana), trees (Alnus incana, Betula pubescens) and grasses (Calamagrostis lapponica, C. purpurea) is likely to benefit from a warmer subarctic climate. Conclusions Seedling establishment is expected to improve in a future warmer subarctic climate, mainly by considerably earlier germination. The magnitudes of the responses are species-specific, which should be taken into account when modelling population growth and migration

  11. Building and Managing Electronic Resources in Digital Era in India with Special Reference to IUCAA and NIV, Pune: A Comparative Case Study

    Science.gov (United States)

    Sahu, H. K.; Singh, S. N.

    2015-04-01

    This paper discusses and presents a comparative case study of two libraries in Pune, India, Inter-University Centre for Astronomy and Astrophysics and Information Centre and Library of National Institute of Virology (Indian Council of Medical Research). It compares how both libraries have managed their e-resource collections, including acquisitions, subscriptions, and consortia arrangements, while also developing a collection of their own resources, including pre-prints and publications, video lectures, and other materials in an institutional repository. This study illustrates how difficult it is to manage electronic resources in a developing country like India, even though electronic resources are used more than print resources. Electronic resource management can be daunting, but with a systematic approach, various problems can be solved, and use of the materials will be enhanced.

  12. Supporting Learning and Information Sharing in Natural Resource Management with Technologies for Electronic Documents

    Science.gov (United States)

    Alem, Leila; McLean, Alistair

    2005-01-01

    Community participation is central to achieving sustainable natural resource management. A prerequisite to informed participation is that community and stakeholder groups have access to different knowledge sources, are more closely attuned to the different issues and viewpoints, and are sufficiently equipped to understand and maybe resolve complex…

  13. MendelWeb: An Electronic Science/Math/History Resource for the WWW.

    Science.gov (United States)

    Blumberg, Roger B.

    This paper describes a hypermedia resource, called MendelWeb that integrates elementary biology, discrete mathematics, and the history of science. MendelWeb is constructed from Gregor Menders 1865 paper, "Experiments in Plant Hybridization". An English translation of Mendel's paper, which is considered to mark the birth of classical and…

  14. Helping Patrons Find Locally Held Electronic Resources: An Interlibrary Loan Perspective

    Science.gov (United States)

    Johnston, Pamela

    2016-01-01

    The University of North Texas Libraries provide extensive online access to academic journals through major vendor databases. As illustrated by interlibrary loan borrowing requests for items held in our databases, patrons often have difficulty navigating the available resources. In this study, the Interlibrary Loan staff used data gathered from the…

  15. QR Codes as Finding Aides: Linking Electronic and Print Library Resources

    Science.gov (United States)

    Kane, Danielle; Schneidewind, Jeff

    2011-01-01

    As part of a focused, methodical, and evaluative approach to emerging technologies, QR codes are one of many new technologies being used by the UC Irvine Libraries. QR codes provide simple connections between print and virtual resources. In summer 2010, a small task force began to investigate how QR codes could be used to provide information and…

  16. Faculty as a community engaged with ongoing curricular development: use of groupware and electronic resources.

    Science.gov (United States)

    Miller, Judy; Koyanagi, Mark; Morgan, Kevin J

    2005-01-01

    This article describes how technology can facilitate faculty engagement in curriculum development, use faculty time efficiently, and ensure program quality. A plan to initiate an accelerated second-degree bachelor of science in nursing option was the impetus for use of groupware electronic strategies to support faculty as valued members of the academic community, engaged in the undergraduate program and its curriculum. This article describes the two Web-based applications (electronic-based strategies) developed: the curriculum development homepage as a collaborative communication tool, and a curricular tracking tool.

  17. Impact of electronic healthcare-associated infection surveillance software on infection prevention resources: a systematic review of the literature.

    Science.gov (United States)

    Russo, P L; Shaban, R Z; Macbeth, D; Carter, A; Mitchell, B G

    2017-09-08

    Surveillance of healthcare-associated infections is fundamental for infection prevention. The methods and practices for surveillance have evolved as technology becomes more advanced. The availability of electronic surveillance software (ESS) has increased, and yet adoption of ESS is slow. It is argued that ESS delivers savings through automation, particularly in terms of human resourcing and infection prevention (IP) staff time. To describe the findings of a systematic review on the impact of ESS on IP resources. A systematic search was conducted of electronic databases Medline and the Cumulative Index to Nursing and Allied Health Literature published between January 1(st), 2006 and December 31(st), 2016 with analysis using the Newcastle-Ottawa Scale. In all, 2832 articles were reviewed, of which 16 studies met the inclusion criteria. IP resources were identified as time undertaken on surveillance. A reduction in IP staff time to undertake surveillance was demonstrated in 13 studies. The reduction proportion ranged from 12.5% to 98.4% (mean: 73.9%). The remaining three did not allow for any estimation of the effect in terms of IP staff time. None of the studies demonstrated an increase in IP staff time. The results of this review demonstrate that adopting ESS yields considerable dividends in IP staff time relating to data collection and case ascertainment while maintaining high levels of sensitivity and specificity. This has the potential to enable reinvestment into other components of IP to maximize efficient use of scarce IP resources. Copyright © 2017 The Healthcare Infection Society. Published by Elsevier Ltd. All rights reserved.

  18. Survey of the use of electronic information resources by students in ...

    African Journals Online (AJOL)

    For libraries to continue to lead in this industry generally and academic libraries in particular, deliberate effort must be made to bring the IT education to every potential user of the libraries. This however must be done based on available data. This is what this study sought to provide- a survey of the use of electronic ...

  19. Data Resource Profile: Cardiovascular disease research using linked bespoke studies and electronic health records (CALIBER)

    Science.gov (United States)

    Denaxas, Spiros C; George, Julie; Herrett, Emily; Shah, Anoop D; Kalra, Dipak; Hingorani, Aroon D; Kivimaki, Mika; Timmis, Adam D; Smeeth, Liam; Hemingway, Harry

    2012-01-01

    The goal of cardiovascular disease (CVD) research using linked bespoke studies and electronic health records (CALIBER) is to provide evidence to inform health care and public health policy for CVDs across different stages of translation, from discovery, through evaluation in trials to implementation, where linkages to electronic health records provide new scientific opportunities. The initial approach of the CALIBER programme is characterized as follows: (i) Linkages of multiple electronic heath record sources: examples include linkages between the longitudinal primary care data from the Clinical Practice Research Datalink, the national registry of acute coronary syndromes (Myocardial Ischaemia National Audit Project), hospitalization and procedure data from Hospital Episode Statistics and cause-specific mortality and social deprivation data from the Office of National Statistics. Current cohort analyses involve a million people in initially healthy populations and disease registries with ∼105 patients. (ii) Linkages of bespoke investigator-led cohort studies (e.g. UK Biobank) to registry data (e.g. Myocardial Ischaemia National Audit Project), providing new means of ascertaining, validating and phenotyping disease. (iii) A common data model in which routine electronic health record data are made research ready, and sharable, by defining and curating with meta-data >300 variables (categorical, continuous, event) on risk factors, CVDs and non-cardiovascular comorbidities. (iv) Transparency: all CALIBER studies have an analytic protocol registered in the public domain, and data are available (safe haven model) for use subject to approvals. For more information, e-mail s.denaxas@ucl.ac.uk PMID:23220717

  20. Electronic Resources in a Next-Generation Catalog: The Case of WorldCat Local

    Science.gov (United States)

    Shadle, Steve

    2009-01-01

    In April 2007, the University of Washington Libraries debuted WorldCat Local (WCL), a localized version of the WorldCat database that interoperates with a library's integrated library system and fulfillment services to provide a single-search interface for a library's physical and electronic content. This brief will describe how WCL incorporates a…

  1. Use of electronic medical records and biomarkers to manage risk and resource efficiencies

    NARCIS (Netherlands)

    Ryan, Dermot; Blakey, John; Chisholm, Alison; Price, David; Thomas, Mike; Ställberg, Björn; Lisspers, Karin; Kocks, Janwillem W H

    2017-01-01

    The migration from paper to electronic medical records (EMRs) was motivated by the administrative need to record, retrieve and process increasing amounts of clinical data in the 1980s. In the intervening period, there has been growing recognition of the potential of such records for achieving care

  2. Development and use of the professional orientation component of electronic educational resources in the context of a competence-based approach

    OpenAIRE

    Belnitskaya Elena Aleksandrovna

    2015-01-01

    The article deals with the issue of professional orientation of pupils through academic subjects in the information society. The development and use of electronic educational resources for training and professional orientation of pupils are considered in the competence approach context.

  3. The Global Open Knowledgebase (GOKb: open linked data supporting electronic resources management and scholarly communication

    Directory of Open Access Journals (Sweden)

    Kristin Antelman

    2015-03-01

    Full Text Available The Global Open Knowledgebase (GOKb, a partnership between Kuali OLE and Jisc, is an open data repository of information related to e-resources as they are acquired and managed by libraries. Because GOKb tracks change over time – titles, publishers, packages – and can be used to populate other tools with data, it is changing the way that libraries think about the knowledge base. Propagation of authoritative and enhanced data about e-resources has the potential to benefit all actors in the supply chain from publishers to libraries. GOKb can also serve as a platform to explore how open knowledge base data can contribute to the broader scholarly community infrastructure, particularly around open access (OA.

  4. Developing and testing an electronic literacy resource for Arab patients before experiencing radiology procedures.

    Science.gov (United States)

    Abuzaid, Mohamed M; Alnuaimi, Aishah M; Abdi, Asma M; Mohajer, Elika A; Mohamed, Ifrah A; Bilwani, Rawan A; Alhammadi, Shaima B

    2016-09-01

    Radiological examinations require prior preparation that patients should be informed about. Radiologists and radiologic technologists have limited time and resources to do so. Therefore, the internet is a valuable and accessible resource for patient education, but the information may not be reliable, especially that in Arabic language. This study aimed to develop online patient education resources about imaging procedures in Arabic. It also evaluated the understandability and actionability of the source materials. The study was conducted at the University of Sharjah between October 2014 and July 2015. A website containing texts and audiovisuals for 21 medical imaging procedures was created. Bilingual (Arabic and English) radiology experts evaluated the materials with automatic score calculation using the Patient Education Materials Assessment Tool. Two procedures were pilot tested by one evaluator, followed by completion of 28 evaluations by 15 selected experts. Nineteen of 21 procedures were randomly evaluated. For printable materials, the mean understandability score was 92.37 (SD=8.355) and actionability score was 92.11 (SD=13.157). For audiovisual materials, the mean understandability score was 97.63 (SD=13.157) and the percentage for all actionability scores was 100%. The minimum acceptable percentage is 70%. The high percentages scored for the online materials indicate that the evaluators were satisfied with the materials included and that the information would be easy for patients to understand and follow. The higher scores for the audiovisual materials indicate that they were considered more effective for improving patient knowledge patient knowledge.

  5. Diazotrophy in alluvial meadows of subarctic river systems.

    Science.gov (United States)

    DeLuca, Thomas H; Zackrisson, Olle; Bergman, Ingela; Díez, Beatriz; Bergman, Birgitta

    2013-01-01

    There is currently limited understanding of the contribution of biological N2 fixation (diazotrophy) to the N budget of large river systems. This natural source of N in boreal river systems may partially explain the sustained productivity of river floodplains in Northern Europe where winter fodder was harvested for centuries without fertilizer amendments. In much of the world, anthropogenic pollution and river regulation have nearly eliminated opportunities to study natural processes that shaped early nutrient dynamics of large river systems; however, pristine conditions in northern Fennoscandia allow for the retrospective evaluation of key biochemical processes of historical significance. We investigated biological N2 fixation (diazotrophy) as a potential source of nitrogen fertility at 71 independent floodplain sites along 10 rivers and conducted seasonal and intensive analyses at a subset of these sites. Biological N2 fixation occurred in all floodplains, averaged 24.5 kg N ha(-1) yr(-1) and was down regulated from over 60 kg N ha(-1) yr(-1) to 0 kg N ha(-1) yr(-1) by river N pollution. A diversity of N2-fixing cyanobacteria was found to colonize surface detritus in the floodplains. The data provide evidence for N2 fixation to be a fundamental source of new N that may have sustained fertility at alluvial sites along subarctic rivers. Such data may have implications for the interpretation of ancient agricultural development and the design of contemporary low-input agroecosystems.

  6. Diazotrophy in alluvial meadows of subarctic river systems.

    Directory of Open Access Journals (Sweden)

    Thomas H DeLuca

    Full Text Available There is currently limited understanding of the contribution of biological N2 fixation (diazotrophy to the N budget of large river systems. This natural source of N in boreal river systems may partially explain the sustained productivity of river floodplains in Northern Europe where winter fodder was harvested for centuries without fertilizer amendments. In much of the world, anthropogenic pollution and river regulation have nearly eliminated opportunities to study natural processes that shaped early nutrient dynamics of large river systems; however, pristine conditions in northern Fennoscandia allow for the retrospective evaluation of key biochemical processes of historical significance. We investigated biological N2 fixation (diazotrophy as a potential source of nitrogen fertility at 71 independent floodplain sites along 10 rivers and conducted seasonal and intensive analyses at a subset of these sites. Biological N2 fixation occurred in all floodplains, averaged 24.5 kg N ha(-1 yr(-1 and was down regulated from over 60 kg N ha(-1 yr(-1 to 0 kg N ha(-1 yr(-1 by river N pollution. A diversity of N2-fixing cyanobacteria was found to colonize surface detritus in the floodplains. The data provide evidence for N2 fixation to be a fundamental source of new N that may have sustained fertility at alluvial sites along subarctic rivers. Such data may have implications for the interpretation of ancient agricultural development and the design of contemporary low-input agroecosystems.

  7. Hydrological role of large icings within glacierized Sub-Arctic watershed: case study in Upper Duke River valley, Yukon, Canada.

    Science.gov (United States)

    Chesnokova, Anna; Baraer, Michel

    2017-04-01

    Sub-Arctic glacierized catchments are complex hydrological systems of paramount importance for water resources management as well as for various ecosystem services. Such systems host many climate-sensitive water sources. Among those, icing is an important component as they provide substantial amount of water during the melt season. Moreover, collecting water of different origins during their formation, icings can be seen as an indicator for different water sources and water pathways that remain active during the freezing period. The present study focuses on genesis and dynamics of large icings within both proglacial field and neighboring alpine meadow in Upper Duke River valley, Yukon, in order to i) provide new insights on water sources and pathways within Sub-Arctic glacierized watersheds, and ii) to quantify contribution of icings to the total runoff of those hydrological systems. A multi-approach technique was applied to cope with the high hydrological complexity met in Sub-Arctic mountainous environments. Time series of positions of large river icings within the study area were obtained using Landsat images for the period 1980-2016. Four time-lapse cameras (TLC) were installed in the watershed targeting two proglacial fields and two alpine meadows in order to monitor icing dynamics all year long. Meteorological data was measured by an Automatic Weather Station in the main valley. In addition air temperature and relative humidity were measured at the location of each TLC. Finally, four icings along the Duke River valley, as well as 2 icings in its main tributary were sampled for stable water isotopes, solutes concentrations and total organic carbon. In addition, samples of freezing exclusion precipitates from icing surfaces were taken. Remote sensing data shows the persistence of large icing complexes in the area during last 30 years: icing within proglacial field appear with almost constant position relative to main glacier tongue on the 30 years long period

  8. An Exploratory study on the use of LibAnswers to Resolve, Track and Monitor Electronic Resources Issues: The KAUST Library experience

    KAUST Repository

    Ramli, Rindra M.

    2017-05-03

    An Exploratory study on KAUST library use of LibAnswers in resolving electronic resources questions received in LibAnswers. It describes the findings of the questions received in LibAnswers. The author made suggestions based on the findings to improve the reference services in responding to e-resources questions.

  9. Preference and Use of Electronic Information and Resources by Blind/Visually Impaired in NCR Libraries in India

    Directory of Open Access Journals (Sweden)

    Shailendra Kumar

    2013-06-01

    Full Text Available This paper aims to determine the preference and use of electronic information and resources by blind/visually impaired users in the leading National Capital Region (NCR libraries of India. Survey methodology has been used as the basic research tool for data collection with the help of questionnaires. The 125 in total users surveyed in all the five libraries were selected randomly on the basis of willingness of the users with experience of working in digital environments to participate in the survey. The survey results were tabulated and analyzed with descriptive statistics methods using Excel software and 'Stata version 11'. The findings reveal that ICT have a positive impact in the lives of people with disabilities as it helps them to work independently and increases the level of confidence among them. The Internet is the most preferred medium of access to information among the majority of blind/visually impaired users. The 'Complexity of content available on the net' is found as the major challenge faced during Internet use by blind users of NCR libraries. 'Audio books on CDs/DVDs and DAISY books' are the most preferred electronic resources among the majority of blind/visually impaired users. This study will help the library professionals and organizations/institutions serving people with disabilities to develop effective library services for blind/visually impaired users in the digital environment on the basis of findings on information usage behavior in the study.

  10. Impact of special early harvest seasons on subarctic-nesting and temperate-nesting Canada geese

    Science.gov (United States)

    Sheaffer, S.E.; Kendall, W.L.; Bowers, E. Frank

    2005-01-01

    Dramatic changes in wintering distributions of Canada geese (Branta canadensis) have occurred over the past 50 years in eastern North America. Declines in numbers of subarctic-nesting geese wintering in southern states, and increases in numbers wintering in northern regions, have resulted in a northern shift in winter distributions. In contrast, numbers of temperate-nesting geese have increased throughout eastern North America. Management efforts to control overabundant temperate-nesting flocks have included the establishment of special early harvest seasons in September. However, the effect of early seasons on survival and harvest of subarctic-nesting populations has not been documented. Understanding the timing of migration movements and the fidelity of subarctic-nesting flocks to terminal winter refuges in the Southeast also is necessary to design early harvest seasons that target temperate-nesting flocks and protect subarctic-nesting populations. We used recoveries of marked geese to estimate survival and harvest rates before and after implementation of early harvest seasons within the Mississippi Flyway during 1976-1999. In addition, we used observations of neck-banded geese from the Southern James Bay Population (SJBP) to evaluate the hypothesis that subarctic-nesting geese arriving prior to mid-December on several key terminal winter refuges in the Southeast (early arriving migrants) were more likely to return to those refuges in subsequent years than were migrants, arriving after mid-December (late arriving migrants). September seasons during 1987-1994 were a minor source of mortality for subarctic-nesting populations and accounted for migrants had higher survival and higher return probabilities than did late arriving migrants or geese that failed to return, numbers of geese wintering on southeastern refuges likely declined because < 60% of the surviving geese affiliated with the refuges would return in a given year and because of lower survival for geese

  11. Internet and electronic resources for inflammatory bowel disease: a primer for providers and patients.

    Science.gov (United States)

    Fortinsky, Kyle J; Fournier, Marc R; Benchimol, Eric I

    2012-06-01

    Patients with inflammatory bowel disease (IBD) are increasingly turning to the Internet to research their condition and engage in discourse on their experiences. This has resulted in new dynamics in the relationship between providers and their patients, with misinformation and advertising potentially presenting barriers to the cooperative patient-provider partnership. This article addresses important issues of online IBD-related health information and social media activity, such as quality, reliability, objectivity, and privacy. We reviewed the medical literature on the quality of online information provided to IBD patients, and summarized the most commonly accessed Websites related to IBD. We also assessed the activity on popular social media sites (such as Facebook, Twitter, and YouTube), and evaluated currently available applications for use by IBD patients and providers on mobile phones and tablets. Through our review of the literature and currently available resources, we developed a list of recommended online resources to strengthen patient participation in their care by providing reliable, comprehensive educational material. Copyright © 2011 Crohn's & Colitis Foundation of America, Inc.

  12. Krill community composition and grazing biology in a sub-Arctic Greenlandic fjord

    DEFF Research Database (Denmark)

    Teglhus, Frederik Wolff; Agersted, Mette Dalgaard; Arendt, Kristine Engel

    of organic material, i.e. the biological pump. Our aim is to improve the understanding and knowledge about the role of krill in a sub-Arctic fjord. During multiple cruises in the Godthåbsfjord, Southwest Greenland, krill abundance, distribution and grazing biology have been investigated trough field....... The present novel knowledge about krill abundance and grazing biology will provide the basis for a discussion of the role of krill in the pelagic food web of the sub-Arctic Godthåbsfjord...

  13. Performance of insulated pipelines in sub-Arctic conditions

    Energy Technology Data Exchange (ETDEWEB)

    Alexander, M. [Garneau Inc., Calgary, AB (Canada); D' Agostino, C. [Nova Chemicals, Calgary, AB (Canada)

    2000-07-01

    A systematic investigation was conducted to determine the main reasons why the insulating value of a pipeline overcoated with extruded polyethylene might fail, particularly in sub-Arctic regions. An insulated pipeline should have excellent insulation values as well as perfect anti-corrosion barrier coatings and an excellent adhesion between the anti-corrosion coating and the polyurethane foam. An insulated pipeline should also be bendable at the ambient construction temperature without damage to the foam or other components of the system. It should also be protected by an outer coating to withstand high mechanical impact. Three types of anti-corrosion barrier coatings are fusion bond epoxy, polyethylene tape, and three layer polyolefin. Polyurethane foam is one of the best heat insulating materials available with an average thermal conductivity of 0.22 W/mK, but it possesses very little mechanical strength. Therefore, it must be overcoated by an external jacket of either polyethylene pipeline tape, extruded polyethylene or spray applied elastomeric polyurethane coatings. An extensive laboratory testing program was initiated to respond to field failures of insulated pipe and low temperatures. The objective was to verify the mechanical properties of insulated pipe at different temperatures. It was shown that at low temperatures, high density polyethylene (HDPE) had significantly reduced elongation properties and its tensile strength increased. It was also determined that double and triple outer jackets provided better impact resistance at low temperature than the single jacket of equivalent thickness. Comparison tests were also conducted with low density polyethylenes. Linear low density polyethylene (LLDPE) was found to be particularly resistant to low temperature damage. In addition, a black jacket proved to be much warmer than a white jacket. On sunny days, the temperature difference could be as high as 15 degrees C. 5 tabs.

  14. Citation Analysis of Engineering Graduate Student Theses Indicates Students Are Using More Electronic Resources

    Directory of Open Access Journals (Sweden)

    Heather MacDonald

    2016-12-01

    Full Text Available A Review of: Becker, D. A., & Chiware, E. R. T. (2015. Citation analysis of masters' theses and doctoral dissertations: Balancing library collections with students' research information needs. Journal of Academic Librarianship, 41(5, 613-620. http://dx.doi.org/10.1016/j.acalib.2015.06.022 Objective – To determine the citation pattern of graduate students’ theses and dissertations. Design – Citation analysis. Setting – An institutional repository at a South African university of technology. Subjects – 201 Engineering Master’s theses and Doctoral dissertations. Methods – A random sample of Master’s theses and Doctoral dissertations from the Faculty of Engineering were analyzed. The theses and dissertations were drawn from the institutional repository covering the period 2005-2014. References were checked for format of the cited items including journal, book, conference proceeding, online item (resource with a URL other than a journal, book or proceeding, and other (anything not in the first four categories. The date of all journal articles was recorded. Journal titles were analyzed in terms of country of origin, language, availability in the library, and online access. Data were categorized by department to determine if there were any differences in the use of materials by department. Data were also analyzed by degree level.

  15. Molecular analyses reveal high species diversity of trematodes in a sub-Arctic lake.

    Science.gov (United States)

    Soldánová, Miroslava; Georgieva, Simona; Roháčová, Jana; Knudsen, Rune; Kuhn, Jesper A; Henriksen, Eirik H; Siwertsson, Anna; Shaw, Jenny C; Kuris, Armand M; Amundsen, Per-Arne; Scholz, Tomáš; Lafferty, Kevin D; Kostadinova, Aneta

    2017-05-01

    To identify trematode diversity and life-cycles in the sub-Arctic Lake Takvatn, Norway, we characterised 120 trematode isolates from mollusc first intermediate hosts, metacercariae from second intermediate host fishes and invertebrates, and adults from fish and invertebrate definitive hosts, using molecular techniques. Phylogenies based on nuclear and/or mtDNA revealed high species richness (24 species or species-level genetic lineages) and uncovered trematode diversity (16 putative new species) from five families typical in lake ecosystems (Allocreadiidae, Diplostomidae, Plagiorchiidae, Schistosomatidae and Strigeidae). Sampling potential invertebrate hosts allowed matching of sequence data for different stages, thus achieving molecular elucidation of trematode life-cycles and exploration of host-parasite interactions. Phylogenetic analyses also helped identify three major mollusc intermediate hosts (Radix balthica, Pisidium casertanum and Sphaerium sp.) in the lake. Our findings increase the known trematode diversity at the sub-Arctic Lake Takvatn, showing that digenean diversity is high in this otherwise depauperate sub-Arctic freshwater ecosystem and indicating that sub-Arctic and Arctic ecosystems may be characterised by unique trematode assemblages. Copyright © 2017 Australian Society for Parasitology. All rights reserved.

  16. Bacterial community structure and soil properties of a subarctic tundra soil in Council, Alaska.

    Science.gov (United States)

    Kim, Hye Min; Jung, Ji Young; Yergeau, Etienne; Hwang, Chung Yeon; Hinzman, Larry; Nam, Sungjin; Hong, Soon Gyu; Kim, Ok-Sun; Chun, Jongsik; Lee, Yoo Kyung

    2014-08-01

    The subarctic region is highly responsive and vulnerable to climate change. Understanding the structure of subarctic soil microbial communities is essential for predicting the response of the subarctic soil environment to climate change. To determine the composition of the bacterial community and its relationship with soil properties, we investigated the bacterial community structure and properties of surface soil from the moist acidic tussock tundra in Council, Alaska. We collected 70 soil samples with 25-m intervals between sampling points from 0-10 cm to 10-20 cm depths. The bacterial community was analyzed by pyrosequencing of 16S rRNA genes, and the following soil properties were analyzed: soil moisture content (MC), pH, total carbon (TC), total nitrogen (TN), and inorganic nitrogen (NH4+ and NO3-). The community compositions of the two different depths showed that Alphaproteobacteria decreased with soil depth. Among the soil properties measured, soil pH was the most significant factor correlating with bacterial community in both upper and lower-layer soils. Bacterial community similarity based on jackknifed unweighted unifrac distance showed greater similarity across horizontal layers than through the vertical depth. This study showed that soil depth and pH were the most important soil properties determining bacterial community structure of the subarctic tundra soil in Council, Alaska. © 2014 The Authors. FEMS Microbiology Ecology published by John Wiley & Sons Ltd on behalf of the Federation of European Microbiological Societies.

  17. Youth Environmental Science Outreach in the Mushkegowuk Territory of Subarctic Ontario, Canada

    Science.gov (United States)

    Karagatzides, Jim D.; Kozlovic, Daniel R.; De Iuliis, Gerry; Liberda, Eric N.; General, Zachariah; Liedtke, Jeff; McCarthy, Daniel D.; Gomez, Natalya; Metatawabin, Daniel; Tsuji, Leonard J. S.

    2011-01-01

    We connected youth of the Mushkegowuk Territory (specifically Fort Albany First Nation) with environmental science and technology mentors in an outreach program contextualized to subarctic Ontario that addressed some of the environmental concerns identified by members of Fort Albany First Nation. Most activities were community-based centering on…

  18. Trophic role and top-down control of a subarctic protozooplankton community

    DEFF Research Database (Denmark)

    Riisgaard, Karen; Swalethorp, Rasmus; Kjellerup, Sanne

    2014-01-01

    Plankton succession was investigated in the subarctic Godthåbsfjord, Western Greenland, from March to August 2010. The trophic role of protozooplankton (ciliates and heterotrophic dinoflagellates) was evaluated with emphasis on their seasonal succession and as prey for the copepod community. The ...

  19. Future climate change will favour non-specialist mammals in the (subarctics.

    Directory of Open Access Journals (Sweden)

    Anouschka R Hof

    Full Text Available Arctic and subarctic (i.e., [sub]arctic ecosystems are predicted to be particularly susceptible to climate change. The area of tundra is expected to decrease and temperate climates will extend further north, affecting species inhabiting northern environments. Consequently, species at high latitudes should be especially susceptible to climate change, likely experiencing significant range contractions. Contrary to these expectations, our modelling of species distributions suggests that predicted climate change up to 2080 will favour most mammals presently inhabiting (subarctic Europe. Assuming full dispersal ability, most species will benefit from climate change, except for a few cold-climate specialists. However, most resident species will contract their ranges if they are not able to track their climatic niches, but no species is predicted to go extinct. If climate would change far beyond current predictions, however, species might disappear. The reason for the relative stability of mammalian presence might be that arctic regions have experienced large climatic shifts in the past, filtering out sensitive and range-restricted taxa. We also provide evidence that for most (subarctic mammals it is not climate change per se that will threaten them, but possible constraints on their dispersal ability and changes in community composition. Such impacts of future changes in species communities should receive more attention in literature.

  20. Molecular analyses reveal high species diversity of trematodes in a sub-Arctic lake

    Science.gov (United States)

    Soldánová, Miroslava; Georgieva, Simona; Roháčováa, Jana; Knudsen, Rune; Kuhn, Jesper A.; Henriksen, Eirik H.; Siwertsson, Anna; Shaw, Jenny C.; Kuris, Armand M.; Amundsen, Per-Arne; Scholz, Tomáš; Lafferty, Kevin D.; Kostadinova, Aneta

    2017-01-01

    To identify trematode diversity and life-cycles in the sub-Arctic Lake Takvatn, Norway, we characterised 120 trematode isolates from mollusc first intermediate hosts, metacercariae from second intermediate host fishes and invertebrates, and adults from fish and invertebrate definitive hosts, using molecular techniques. Phylogenies based on nuclear and/or mtDNA revealed high species richness (24 species or species-level genetic lineages), and uncovered trematode diversity (16 putative new species) from five families typical in lake ecosystems (Allocreadiidae, Diplostomidae, Plagiorchiidae, Schistosomatidae and Strigeidae). Sampling potential invertebrate hosts allowed matching of sequence data for different stages, thus achieving molecular elucidation of trematode life-cycles and exploration of host-parasite interactions. Phylogenetic analyses also helped identify three major mollusc intermediate hosts (Radix balthica, Pisidium casertanum and Sphaerium sp.) in the lake. Our findings increase the known trematode diversity at the sub-Arctic Lake Takvatn, showing that digenean diversity is high in this otherwise depauperate sub-Arctic freshwater ecosystem, and indicating that sub-Arctic and Arctic ecosystems may be characterised by unique trematode assemblages.

  1. Role of predation in biological communities in naturally eutrophic sub-Arctic Lake Myvatn, Iceland

    DEFF Research Database (Denmark)

    Canedo-Argueles, Miguel; Sgarzi, Serena; Arranz, Ignasi

    2017-01-01

    . To study this, we conducted a 3-month in situ-controlled experiment in sub-Arctic Lake MA 1/2 vatn, Iceland. We used the planktivorous fish three-spined sticklebacks (Gasterosteus aculeatus) as the main top predator. The cladocerans Eurycercus lamellatus and Acroperus harpae were significantly associated...

  2. Long-term warming and litter addition affects nitrogen fixation in a subarctic heath

    DEFF Research Database (Denmark)

    Sørensen, Pernille Lærkedal; Michelsen, Anders

    2011-01-01

    the effects of anticipated global climate change on N fixation rates in a subarctic moist heath, a field experiment was carried out in Northern Sweden. Warming was induced by plastic tents, and in order to simulate the effects of future increased tree cover, birch litter was added each fall for 9 years before...

  3. Green Supply Chain Collaboration for Fashionable Consumer Electronics Products under Third-Party Power Intervention—A Resource Dependence Perspective

    Directory of Open Access Journals (Sweden)

    Jiuh-Biing Sheu

    2014-05-01

    Full Text Available Under third-party power intervention (TPPI, which increases uncertainty in task environments, complex channel power interplays and restructuring are indispensable among green supply chain members as they move toward sustainable collaborative relationships for increased viability and competitive advantage. From the resource dependence perspective, this work presents a novel conceptual model to investigate the influence of political and social power on channel power restructuring and induced green supply chain collaboration in brander-retailer bidirectional green supply chains of fashionable consumer electronics products (FCEPs. An FCEP refers to the consumer electronics product (e.g., personal computers, mobile phones, computer notebooks, and game consoles with the features of a well-known brand associated, a short product lifecycle, timely and fashionable design fit for market trends, and quick responsiveness to the variations of market demands. The proposed model is tested empirically using questionnaire data obtained from retailers in the FCEP brander-retailer distribution channels. Analytical results reveal that as an extension of political and social power, TPPI positively affects the reciprocal interdependence of dyadic members and reduces power asymmetry, thereby enhancing the collaborative relationship of dyadic members and leading to improved green supply chain performance. Therein, reciprocal interdependence underlying collaborative relationship is the key to reducing the external environmental uncertainties in the TPPI context.

  4. The management of online resources and long-term saving of electronic documents by transfer into the digital space

    Directory of Open Access Journals (Sweden)

    Marius Daniel MAREŞ

    2011-12-01

    The electronic archive refers to the electronic storage system, along with the totality of electronic-type stored documents, while using as storage support any environment that can support storing and from which an electronic document can be presented.

  5. Spectral properties of subarctic plants for remote ecosystem assessment

    Science.gov (United States)

    Golubeva, Elena; Tutubalina, Olga; Rees, Gareth; Zimin, Mikhail; Mikheeva, Anna

    2014-05-01

    Multispectral and hyperspectral satellite images are increasingly used to identify properties of vegetation, its state, dynamics and productivity. Arctic vegetation is sensitive to changing habitat conditions related to both natural causes (in particular climatic trends), and human impact (both direct and indirect, e.g. associated with air, soil and water pollution). Change in the state of individual plants and of vegetation cover in general enables their use as indicators of natural and anthropogenic processes, manifested in satellite images through change of their spectral reflectance properties. These processes can be studied by identifying significant links between spectral properties of objects in satellite images and corresponding properties of plants, recorded in situ. We focus on the spectral signatures of subarctic plants dominating treeline ecotone ecosystems to assess the feasibility of mapping the spatial structure and dynamics of vegetation using multispectral and hyperspectral satellite imagery. Our model objects are tundra plants and ecosystems in both natural and technogenically disturbed environments in the central part of the Kola Peninsula, Russia. We conducted ground spectroradiometry with two spectroradiometers: ASD FieldSpec 3 Hi-res (350-2500 nm range with resolution from 3 to 10 nm) and SkyeInstruments SpectroSense 2+ (bands centred at 480, 550, 680, 840 nm, 50-130 nm wide) for samples of different species: Betula pubescens S.L., B. tortuosa, Picea abies, Betula nana, Ledum palustre, Vaccinium uligimosum, V. myrtillus, V. vitis-idaea, Empetrum hermaphroditum, Cetraria islandica (L), Flavocetraria nivalis (Cetraria nivalis), Alectoria ochroleuca, Cladonia arbuscula S.L., Hylocomium splendens and Pleurozium Shreberi. The results demonstrate the ability of green vegetation to selectively reflect solar radiation, depending on the species composition and state of the plants. Our results will be included in a spectral library of northern plants

  6. Optimal Sleep Duration in the Subarctic with Respect to Obesity Risk Is 8-9 Hours: e56756

    National Research Council Canada - National Science Library

    May Trude Johnsen; Rolf Wynn; Trond Bratlid

    2013-01-01

    ...) and abdominal obesity. The optimal sleep duration regarding BMI has previously been found to be 7-8 hours, but these studies have not been carried out in the subarctic or have lacked some central variables...

  7. Innovative direct energy conversion systems using electronic adiabatic processes of electron fluid in solid conductors: new plants of electrical power and hydrogen gas resources without environmental pollutions

    Energy Technology Data Exchange (ETDEWEB)

    Kondoh, Y.; Kondo, M.; Shimoda, K.; Takahashi, T. [Gunma Univ., Dept. of Electronic Engineering, Kiryu, Gunma (Japan)

    2001-07-01

    It is shown that using a novel recycling process of the environmental thermal energy, innovative permanent auto-working direct energy converter systems (PA-DEC systems) from the environmental thermal to electrical and/or chemical potential (TE/CP) energies, abbreviated as PA-TE/CP-DEC systems, can be used for new auto-working electrical power plants and the plants of the compressible and conveyable hydrogen gas resources at various regions in the whole world, with contributions to the world peace and the economical development in the south part of the world. It is shown that the same physical mechanism by free electrons and electrical potential determined by temperature in conductors, which include semiconductors, leads to the Peltier effect and the Seebeck one. It is experimentally clarified that the long distance separation between two {pi} type elements of the heat absorption (HAS) and the production one (HPS) of the Peltier effect circuit system or between the higher temperature side (HTS) and the lower one (LTS) of the Seebeck effect circuit one does not change in the whole for the both effects. By using present systems, we do not need to use petrified fuels such as coals, oils, and natural gases in order to decrease the greenhouse effect by the CO{sub 2} surrounding the earth. Furthermore, we do not need plats of nuclear fissions that left radiating wastes, i.e., with no environmental pollutions. The PA-TE/CP-DEC systems can be applicable for several km scale systems to the micro ones, such as the plants of the electrical power, the compact transportable hydrogen gas resources, a large heat energy container, which can be settled at far place from thermal energy absorbing area, the refrigerators, the air conditioners, home electrical apparatuses, and further the computer elements. It is shown that the simplest PA-TE/CP-DEC system can be established by using only the Seebeck effect components and the resolving water ones. It is clarified that the externally

  8. Development of an electronic medical record based alert for risk of HIV treatment failure in a low-resource setting.

    Directory of Open Access Journals (Sweden)

    Nancy Puttkammer

    Full Text Available The adoption of electronic medical record systems in resource-limited settings can help clinicians monitor patients' adherence to HIV antiretroviral therapy (ART and identify patients at risk of future ART failure, allowing resources to be targeted to those most at risk.Among adult patients enrolled on ART from 2005-2013 at two large, public-sector hospitals in Haiti, ART failure was assessed after 6-12 months on treatment, based on the World Health Organization's immunologic and clinical criteria. We identified models for predicting ART failure based on ART adherence measures and other patient characteristics. We assessed performance of candidate models using area under the receiver operating curve, and validated results using a randomly-split data sample. The selected prediction model was used to generate a risk score, and its ability to differentiate ART failure risk over a 42-month follow-up period was tested using stratified Kaplan Meier survival curves.Among 923 patients with CD4 results available during the period 6-12 months after ART initiation, 196 (21.2% met ART failure criteria. The pharmacy-based proportion of days covered (PDC measure performed best among five possible ART adherence measures at predicting ART failure. Average PDC during the first 6 months on ART was 79.0% among cases of ART failure and 88.6% among cases of non-failure (p<0.01. When additional information including sex, baseline CD4, and duration of enrollment in HIV care prior to ART initiation were added to PDC, the risk score differentiated between those who did and did not meet failure criteria over 42 months following ART initiation.Pharmacy data are most useful for new ART adherence alerts within iSanté. Such alerts offer potential to help clinicians identify patients at high risk of ART failure so that they can be targeted with adherence support interventions, before ART failure occurs.

  9. Contrasting trends in hydrologic extremes for two sub-arctic catchments in northern Sweden - Does glacier melt matter?

    Science.gov (United States)

    Dahlke, H. E.; Lyon, S. W.; Stedinger, J. R.; Rosqvist, G.; Jansson, P.

    2012-04-01

    Climate warming in the high-latitude environments of Sweden is raising concerns about its impacts upon hydrology. In order to manage future water resources in these snowmelt-dominated high-latitude and altitude catchments there is a need to determine how climatic change will influence glacial meltwater rates and terrestrial hydrology. This uncertainty is particularly acute for hydrologic extremes (flood events) because understanding the frequency of such unusual events requires long records of observation not often available for high-latitude and altitude catchments. This study presents a statistical analysis of trends in the magnitude and timing of hydrologic extremes (flood events) and the mean summer (June-August) discharge in two sub-arctic catchments, Tarfalajokk and Abiskojokk, in northern Sweden. The catchments have different glacier covers of 30% and 1%, respectively. Statistically significant hydrologic trends (at the 5% level) were identified for both catchments on an annual and on a seasonal scale (3-months averages) using the Mann-Kendall trend test and were related to observed changes in the precipitation and air temperature. Both catchments showed a statistically significant increase in the annual mean air temperature over the comparison time period of 1985-2009 (Tarfalajokk & Abiskojokk pflood peaks and the mean summer discharge. Hydrologic trends indicated an amplification of the hydrologic response in the highly glaciated catchment and a dampening of the response in the non-glaciated catchment. The glaciated mountain catchment showed a statistically significant increasing trend in the mean summer discharge that is clearly correlated to the decrease in glacier mass balance and the increase in air temperature. However, the catchment showed also a significant increase in the flood magnitudes, which are clearly correlated to the occurrence of extreme precipitation events, indicating a shift of the dominant storm runoff mechanism towards rainfall

  10. Consumer reports [electronic resource

    National Research Council Canada - National Science Library

    1942-01-01

    ... only. A limited number of selected reports, advice on product selection and safety alerts are freely available, as are a five year listing of product recalls, a listing of major consumer product...

  11. Electronic Information Resources (EIR Adoption in Private University Libraries: The Moderating Effect of Productivity and Relative Advantage on Perceived Usefulness

    Directory of Open Access Journals (Sweden)

    Izuagbe, Roland

    2016-03-01

    Full Text Available The study tested a hybrid model with constructs drawn from the Technology Acceptance Model (TAM and Diffusion of Innovation (DOI theory in order to examine the moderating effect of productivity and relative advantage (RA on perceived usefulness (PU vis-à-vis electronic information resources (EIR adoption in private university libraries in Ogun and Osun States of Nigeria. The descriptive research design was adopted in the study. The population consisted of 61 (55.0% librarians and 50 (45.0% library officers (totaling 116—100% in Babcock University, Bells University, Covenant University, Bowen University, Oduduwa University, and Redeemer's University. Purposive sampling procedure was adopted after which total enumeration was used since the total population is small. The questionnaire was used for data collection. Of the 116 copies of the questionnaire administered, 111 (95.7% were found usable. The instrument was structured based on a 4-point Likert agreement scale of Strongly Agree, Agree, Disagree, and Strongly Disagree. Data were analyzed using descriptive statistics like tables of frequency counts and percentage. The findings revealed that productivity and relative advantage are significant moderators of perceived usefulness of EIR adoption in private university libraries in Ogun and Osun States, Nigeria.

  12. The module of methodical support in system of electronic educational resources as the innovative element of the modern maintenance of formation

    Directory of Open Access Journals (Sweden)

    Ольга Николаевна Крылова

    2009-06-01

    Full Text Available The article introduces some results of research, which were devoted to evaluation of tearches' mobility to introduce innovations in the contents of education. The author considers innovative potential of modules of the methodical support for system of electronic educational resources.

  13. Charting a Course through CORAL: Texas A&M University Libraries' Experience Implementing an Open-Source Electronic Resources Management System

    Science.gov (United States)

    Hartnett, Eric; Beh, Eugenia; Resnick, Taryn; Ugaz, Ana; Tabacaru, Simona

    2013-01-01

    In 2010, after two previous unsuccessful attempts at electronic resources management system (ERMS) implementation, Texas A&M University (TAMU) Libraries set out once again to find an ERMS that would fit its needs. After surveying the field, TAMU Libraries selected the University of Notre Dame Hesburgh Libraries-developed, open-source ERMS,…

  14. The BRIGHTEN Program: Implementation and Evaluation of a Program to Bridge Resources of an Interdisciplinary Geriatric Health Team via Electronic Networking

    Science.gov (United States)

    Emery, Erin E.; Lapidos, Stan; Eisenstein, Amy R.; Ivan, Iulia I.; Golden, Robyn L.

    2012-01-01

    Purpose: To demonstrate the feasibility of the BRIGHTEN Program (Bridging Resources of an Interdisciplinary Geriatric Health Team via Electronic Networking), an interdisciplinary team intervention for assessing and treating older adults for depression in outpatient primary and specialty medical clinics. The BRIGHTEN team collaborates "virtually"…

  15. Impacts of Climate Change Induced Vegetation Responses on BVOC Emissions from Subarctic Heath Ecosystems

    DEFF Research Database (Denmark)

    Valolahti, Hanna Maritta

    temperature has been regulating annual plant biomass production, but ongoing global warming is more pronounced in these regions than what the global average is. This may increase the importance of subarctic and arctic vegetation as a source of BVOC emissions in near future. This thesis aims to increase......The role of biogenic volatile organic compounds (BVOCs) affecting Earths’ climate system is one of the greatest uncertainties when modelling the global climate change. BVOCs presence in the atmosphere can have both positive and negative climate feedback mechanisms when they involve atmospheric...... the understanding of the controls of BVOC emissions from subarctic ecosystems under climate change by studying the responses to long-term manipulations from leaf level to small ecosystem scale. Leaf-level studies showed different anatomical responses for warming and shading manipulations between studied species...

  16. Doubled volatile organic compound emissions from subarctic tundra under simulated climate warming

    DEFF Research Database (Denmark)

    Faubert, Patrick; Tiiva, Paivi; Rinnan, Åsmund

    2010-01-01

    • Biogenic volatile organic compound (BVOC) emissions from arctic ecosystems are important in view of their role in global atmospheric chemistry and unknown feedbacks to global warming. These cold ecosystems are hotspots of climate warming, which will be more severe here than averaged over...... the globe. We assess the effects of climatic warming on non-methane BVOC emissions from a subarctic heath. • We performed ecosystem-based chamber measurements and gas chromatography-mass spectrometry (GC-MS) analyses of the BVOCs collected on adsorbent over two growing seasons at a wet subarctic tundra...... of a focus on BVOC emissions during climate change. The observed changes have implications for ecological interactions and feedback effects on climate change via impacts on aerosol formation and indirect greenhouse effects....

  17. Extensive forest leaf area survey aiming at detection of vegetation change in subarctic-boreal zone

    OpenAIRE

    Kusakabe,Tomoko; Tsuzuki,Hayato; Hughes,Gary; Sweda,Tatsuo

    2000-01-01

    The warming resulting from increasing anthropogenic carbon dioxide and other greenhouse gasses is expected to be most prominent in the subarctic-boreal region of the Northern Hemisphere. With the objective of setting up a baseline to monitor possible vegetation change in this region, a continuous vegetation profile extending 600km from Edmonton, Alberta to Cluff Lake, Saskatchewan, Canada was measured using an airborne infrared laser altimeter mounted on a helicopter. Then the distribution of...

  18. Remote Sensing Methods for Environmental Monitoring of Human Impact on sub-Arctic Ecosystems in Europe

    OpenAIRE

    Shipigina, Ekaterina

    2013-01-01

    The role and scale of human impact on the global environment is a question of special importance to the scientific community and the world as a whole. This impact has dramatically increased since the beginning of industrialisation, yet its understanding remains patchy. The sub-Arctic plays a central role in forming the global environment due to the vast territory of boreal forest and tundra. Severe climatic conditions make its ecosystems highly sensitive to any natural and human disturbances....

  19. Influence of snowfall and melt timing on tree growth in subarctic Eurasia

    Science.gov (United States)

    Vaganov, E. A.; Hughes, M. K.; Kirdyanov, A. V.; Schweingruber, F. H.; Silkin, P. P.

    1999-07-01

    The causes of a reduced sensitivity of high-latitude tree growth to variations in summer temperature for recent decades,, compared to earlier this century, are unknown. This sensitivity change is problematic, in that relationships between tree-ring properties and temperature are widely used for reconstructing past climate. Here we report an analysis of tree-ring and climate data from the forest-tundra zone, in combination with a mechanistic model of tree-ring growth, to argue that an increasing trend of winter precipitation over the past century in many subarctic regions led to delayed snow melt in these permafrost environments. As a result, the initiation of cambial activity (necessary for the formation of wood cells) has been delayed relative to the pre-1960 period in the Siberian subarctic. Since the early 1960s, less of the growth season has been during what had previously been the period of maximal growth sensitivity to temperature. This shift results not only in slower growth, but also in a reduced correlation between growth and temperature. Our results suggest that changes in winter precipitation should be considered in seeking explanations for observed changes in the timing of the `spring greening' of high-latitude forests, and should be taken into account in the study of the role of the Siberian subarctic forest in the global carbon cycle.

  20. Enhanced subarctic Pacific stratification and nutrient utilization during glacials over the last 1.2 Myr

    Science.gov (United States)

    Knudson, Karla P.; Ravelo, Ana Christina

    2015-11-01

    The relationship between climate, biological productivity, and nutrient flux is of considerable interest in the subarctic Pacific, which represents an important high-nitrate, low-chlorophyll region. While previous studies suggest that changes in iron supply and/or physical ocean stratification could hypothetically explain orbital-scale fluctuations in subarctic Pacific nutrient utilization and productivity, previous records of nutrient utilization are too short to evaluate these relationships over many glacial-interglacial cycles. We present new, high-resolution records of sedimentary δ15N, which offer the first opportunity to evaluate systematic, orbital-scale variations in subarctic Pacific nitrate utilization from 1.2 Ma. Nitrate utilization was enhanced during all glacials, varied with orbital-scale periodicity since the mid-Pleistocene transition, was strongly correlated with enhanced aeolian dust and low atmospheric CO2, but was not correlated with productivity. These results suggest that glacial stratification, rather than iron fertilization, systematically exerted an important regional control on nutrient utilization and air-sea carbon flux.

  1. Slow acidification of the winter mixed layer in the subarctic western North Pacific

    Science.gov (United States)

    Wakita, Masahide; Nagano, Akira; Fujiki, Tetsuichi; Watanabe, Shuichi

    2017-08-01

    We used carbon dioxide (CO2) system data collected during 1999-2015 to investigate ocean acidification at time series sites in the western subarctic region of the North Pacific Ocean. The annual mean pH at station K2 decreased at a rate of 0.0025 ± 0.0010 year-1 mostly in response to oceanic uptake of anthropogenic CO2. The Revelle factor increased rapidly (0.046 ± 0.022 year-1), an indication that the buffering capacity of this region of the ocean has declined faster than at other time series sites. In the western subarctic region, the pH during the winter decline at a slower rate of 0.0008 ± 0.0004 year-1. This was attributed to a reduced rate of increase of dissolved inorganic carbon (DIC) and an increase of total alkalinity (TA). The reduction of DIC increase was caused by the decline of surface water density associated with the pycnocline depression and the reduction of vertical diffusion flux from the upper pycnocline. These physical changes were probably caused by northward shrinkage of the western subarctic gyre and global warming. Meanwhile, the contribution of the density decline to the TA increase is canceled out by that of the reduced vertical diffusive flux. We speculated that the winter TA increase is caused mainly by the accumulation of TA due to the weakened calcification by organisms during the winter.

  2. Current temporal trends in moth abundance are counter to predicted effects of climate change in an assemblage of subarctic forest moths.

    Science.gov (United States)

    Hunter, Mark D; Kozlov, Mikhail V; Itämies, Juhani; Pulliainen, Erkki; Bäck, Jaana; Kyrö, Ella-Maria; Niemelä, Pekka

    2014-06-01

    Changes in climate are influencing the distribution and abundance of the world's biota, with significant consequences for biological diversity and ecosystem processes. Recent work has raised concern that populations of moths and butterflies (Lepidoptera) may be particularly susceptible to population declines under environmental change. Moreover, effects of climate change may be especially pronounced in high latitude ecosystems. Here, we examine population dynamics in an assemblage of subarctic forest moths in Finnish Lapland to assess current trajectories of population change. Moth counts were made continuously over a period of 32 years using light traps. From 456 species recorded, 80 were sufficiently abundant for detailed analyses of their population dynamics. Climate records indicated rapid increases in temperature and winter precipitation at our study site during the sampling period. However, 90% of moth populations were stable (57%) or increasing (33%) over the same period of study. Nonetheless, current population trends do not appear to reflect positive responses to climate change. Rather, time-series models illustrated that the per capita rates of change of moth species were more frequently associated negatively than positively with climate change variables, even as their populations were increasing. For example, the per capita rates of change of 35% of microlepidoptera were associated negatively with climate change variables. Moth life-history traits were not generally strong predictors of current population change or associations with climate change variables. However, 60% of moth species that fed as larvae on resources other than living vascular plants (e.g. litter, lichen, mosses) were associated negatively with climate change variables in time-series models, suggesting that such species may be particularly vulnerable to climate change. Overall, populations of subarctic forest moths in Finland are performing better than expected, and their populations

  3. Use of Electronic Resources by M.Sc. Chemistry Students at Arts Science and Commerce College Chopda Dist-Jalgaon

    National Research Council Canada - National Science Library

    Dr.Paithankar Rajeev; R., Mr.Kamble V.R

    2017-01-01

    ... continuously growth in teaching learning process. In the modern era librarian should provide better services to the users for accessing e-resources as like e-books, e-journals, e-databases, e-reports etc...

  4. Barriers to electronic access and delivery of educational information in resource constrained public schools: a case of Greater Tubatse Municipality

    CSIR Research Space (South Africa)

    Pholotho, T

    2016-05-01

    Full Text Available Information and Communication Technologies (ICTs) are capable of expanding access to quality education, educational resources and provide teachers with new skills. Nevertheless, a majority of rural public schools have limited ICTs, mainly due...

  5. Electronic Grey Literature in Accelerator Science and Its Allied Subjects : Selected Web Resources for Scientists and Engineers

    CERN Document Server

    Rajendiran, P

    2006-01-01

    Grey literature Web resources in the field of accelerator science and its allied subjects are collected for the scientists and engineers of RRCAT (Raja Ramanna Centre for Advanced Technology). For definition purposes the different types of grey literature are described. The Web resources collected and compiled in this article (with an overview and link for each) specifically focus on technical reports, preprints or e-prints, which meet the main information needs of RRCAT users.

  6. Radiocesium in the western subarctic area of the North Pacific Ocean, Bering Sea, and Arctic Ocean in 2013 and 2014.

    Science.gov (United States)

    Kumamoto, Yuichiro; Aoyama, Michio; Hamajima, Yasunori; Nishino, Shigeto; Murata, Akihiko; Kikuchi, Takashi

    2017-08-01

    We measured radiocesium ( 134 Cs and 137 Cs) in seawater from the western subarctic area of the North Pacific Ocean, Bering Sea, and Arctic Ocean in 2013 and 2014. Fukushima-derived 134 Cs in surface seawater was observed in the western subarctic area and Bering Sea but not in the Arctic Ocean. Vertical profile of 134 Cs in the Canada Basin of the Arctic Ocean implies that Fukushima-derived 134 Cs intruded into the basin from the Bering Sea through subsurface (150m depth) in 2014. Copyright © 2017 Elsevier Ltd. All rights reserved.

  7. Optimal sleep duration in the subarctic with respect to obesity risk is 8-9 hours.

    Directory of Open Access Journals (Sweden)

    May Trude Johnsen

    Full Text Available INTRODUCTION: Sleep duration, chronotype and social jetlag have been associated with body mass index (BMI and abdominal obesity. The optimal sleep duration regarding BMI has previously been found to be 7-8 hours, but these studies have not been carried out in the subarctic or have lacked some central variables. The aims of our study were to examine the associations between sleep variables and body composition for people living in the subarctic, taking a range of variables into consideration, including lifestyle variables, health variables and biological factors. METHODS: The cross sectional population Tromsø Study was conducted in northern Norway, above the Arctic Circle. 6413 persons aged 30-65 years completed questionnaires including self-reported sleep times, lifestyle and health. They also measured height, weight, waist and hip circumference, and biological factors (non-fasting serum level of cholesterol, HDL-cholesterol, LDL-cholesterol, triglycerides and glucose. The study period was from 1 October 2007 to 19 December 2008. RESULTS: The optimal sleep length regarding BMI and waist circumference was found to be 8-9 hours. Short sleepers (<6 h had about 80% increased risk of being in the BMI≥25 kg/m2 group and male short sleepers had doubled risk of having waist circumference ≥102 cm compared to 8-9 hours sleepers. We found no impact of chronotype or social jetlag on BMI or abdominal obesity after controlling for health, lifestyle, and biological parameters. CONCLUSIONS: In our subarctic population, the optimal sleep duration time regarding risk of overweight and abdominal obesity was 8-9 hours, which is one hour longer compared to findings from other studies. Short sleepers had 80% increased risk of being overweight, and men had a doubled risk of having abdominal obesity. We found no associations between chronotype or social jetlag and BMI or abdominal obesity, when we took a range of life-style, health and biological variables into

  8. The Atmosphere's Imprint on the Hydrologic and Carbon Cycle in the Alaskan Arctic and Subarctic

    Science.gov (United States)

    Nichols, J. E.; Peteet, D. M.; Moy, C. M.

    2011-12-01

    The Alaskan arctic and subarctic is a region rich with terrestrial carbon stored in peatlands which have been accumulating thoughout the Holocene. Such peatlands are important players in the terrestrial carbon cycle. One major influence on the amount of carbon stored in peatlands is the amount and seasonality of precipitation, which is controlled, in turn, by changes in atmospheric circulation. The Holocene changes in atmospheric circulation over the North Pacific, and the Gulf of Alaska in particular is poorly understood. In the case of the Alaskan subarctic, for example, the Aleutian Low is an important driver of moisture balance change. Further, changes in the Aleutian low also control fluxes of important micronutrients such as iron from the land surface to the Gulf of Alaska, an area of the ocean where phytoplankton growth is iron limited. We reconstructed the hydrogen isotopes of precipitation, the amount of surface evaporation, and the overall moisture balance through the Holocene at three peatland sites in the Alaskan arctic and subarctic: Goldmine Bog, Fairbanks, (65°N, 147°W), Phalarope Bog, Kodiak (57°N, 154°W), and Bear Bog, Cordova (60°N, 145°W). These data reveal large, regionally consistent changes in atmospheric circulation throughout the Holocene that play an important role in changing the amount of carbon stored in peatlands. Understanding the relationships among atmospheric circulation, the hydrologic cycle, and the carbon cycle in the past provide an important guide for predicting the carbon cycle changes that will result from future climate warming.

  9. Both seed germination and seedling mortality increase with experimental warming and fertilization in a subarctic tundra

    Science.gov (United States)

    Vandeplas, Nicolas; Kockelbergh, Fred; Nijs, Ivan

    2017-01-01

    Abstract Climate change is expected to force many species in arctic regions to migrate and track their climatic niche. This requires recruitment from seed, which currently shows very low rates in arctic regions, where long-lived and vegetatively reproducing plants dominate. Therefore, we pose the question whether recruitment (germination and seedling establishment) in arctic regions will significantly improve in a warmer world, and thus allow species to follow their climatic niche. We used a full factorial experiment to examine if realistic warmer temperatures (+3 °C; infrared radiation) and increased nitrogen availability (+1.4 g N m−2 year−1) affected germination, seedling survival and above- and below-ground seedling biomass in five species common in subarctic regions (Anthoxanthum odoratum, Betula nana, Pinus sylvestris, Solidago virgaurea, Vaccinium myrtillus). We found that warming increased seedling emergence in all species, but that subsequent mortality also increased, resulting in no net warming effect on seedling establishment. Warming slightly increased above-ground seedling biomass. Fertilization, on the other hand, did not influence seedling biomass, but it increased seedling establishment in B. nana while it reduced establishment in V. myrtillus. This may help B. nana dominate over V. myrtillus in warmer tundra. Surprisingly, no interactive effects between warming and fertilization were found. The lack of a general positive response of seedling establishment to warmer and more nutrient-rich conditions suggests that (sub)arctic species may experience difficulties in tracking their climatic niche. Predictions of future species distributions in arctic regions solely based on abiotic factors may therefore overestimate species’ ranges due to their poor establishment. Also, the opposite response to fertilization of two key (sub)arctic dwarf shrubs, i.e. B. nana and V. myrtillus, could have important implications for the future development of arctic

  10. Conceptualising the interactive effects of climate change and biological invasions on subarctic freshwater fish.

    Science.gov (United States)

    Rolls, Robert J; Hayden, Brian; Kahilainen, Kimmo K

    2017-06-01

    Climate change and species invasions represent key threats to global biodiversity. Subarctic freshwaters are sentinels for understanding both stressors because the effects of climate change are disproportionately strong at high latitudes and invasion of temperate species is prevalent. Here, we summarize the environmental effects of climate change and illustrate the ecological responses of freshwater fishes to these effects, spanning individual, population, community and ecosystem levels. Climate change is modifying hydrological cycles across atmospheric, terrestrial and aquatic components of subarctic ecosystems, causing increases in ambient water temperature and nutrient availability. These changes affect the individual behavior, habitat use, growth and metabolism, alter population spawning and recruitment dynamics, leading to changes in species abundance and distribution, modify food web structure, trophic interactions and energy flow within communities and change the sources, quantity and quality of energy and nutrients in ecosystems. Increases in temperature and its variability in aquatic environments underpin many ecological responses; however, altered hydrological regimes, increasing nutrient inputs and shortened ice cover are also important drivers of climate change effects and likely contribute to context-dependent responses. Species invasions are a complex aspect of the ecology of climate change because the phenomena of invasion are both an effect and a driver of the ecological consequences of climate change. Using subarctic freshwaters as an example, we illustrate how climate change can alter three distinct aspects of species invasions: (1) the vulnerability of ecosystems to be invaded, (2) the potential for species to spread and invade new habitats, and (3) the subsequent ecological effects of invaders. We identify three fundamental knowledge gaps focused on the need to determine (1) how environmental and landscape characteristics influence the

  11. Geographic Distribution of Ammonia-Oxidizing Archaea along the Kuril Islands in the Western Subarctic Pacific

    Directory of Open Access Journals (Sweden)

    Hongmei Jing

    2017-06-01

    Full Text Available Community composition and abundance of ammonia-oxidizing archaea (AOA in the ocean were affected by different physicochemical conditions, but their responses to physical barriers (such as a chain of islands were largely unknown. In our study, geographic distribution of the AOA from the surface photic zone to the deep bathypelagic waters in the western subarctic Pacific adjacent to the Kuril Islands was investigated using pyrosequencing based on the ammonia monooxygenase subunit A (amoA gene. Genotypes of clusters A and B dominated in the upper euphotic zone and the deep waters, respectively. Quantitative PCR assays revealed that the occurrence and ammonia-oxidizing activity of ammonia-oxidizing archaea (AOA reached their maxima at the depth of 200 m, where a higher diversity and abundance of actively transcribed AOA was observed at the station located in the marginal sea exposed to more terrestrial input. Similar community composition of AOA observed at the two stations adjacent to the Kuril Islands maybe due to water exchange across the Bussol Strait. They distinct from the station located in the western subarctic gyre, where sub-cluster WCAII had a specific distribution in the surface water, and this sub-cluster seemed having a confined distribution in the western Pacific. Habitat-specific groupings of different WCB sub-clusters were observed reflecting the isolated microevolution existed in cluster WCB. The effect of the Kuril Islands on the phylogenetic composition of AOA between the Sea of Okhotsk and the western subarctic Pacific is not obvious, possibly because our sampling stations are near to the Bussol Strait, the main gateway through which water is exchanged between the Sea of Okhotsk and the Pacific. The vertical and horizontal distribution patterns of AOA communities among stations along the Kuril Islands were essentially determined by the in situ prevailing physicochemical gradients along the two dimensions.

  12. Optimal sleep duration in the subarctic with respect to obesity risk is 8-9 hours.

    Science.gov (United States)

    Johnsen, May Trude; Wynn, Rolf; Bratlid, Trond

    2013-01-01

    Sleep duration, chronotype and social jetlag have been associated with body mass index (BMI) and abdominal obesity. The optimal sleep duration regarding BMI has previously been found to be 7-8 hours, but these studies have not been carried out in the subarctic or have lacked some central variables. The aims of our study were to examine the associations between sleep variables and body composition for people living in the subarctic, taking a range of variables into consideration, including lifestyle variables, health variables and biological factors. The cross sectional population Tromsø Study was conducted in northern Norway, above the Arctic Circle. 6413 persons aged 30-65 years completed questionnaires including self-reported sleep times, lifestyle and health. They also measured height, weight, waist and hip circumference, and biological factors (non-fasting serum level of cholesterol, HDL-cholesterol, LDL-cholesterol, triglycerides and glucose). The study period was from 1 October 2007 to 19 December 2008. The optimal sleep length regarding BMI and waist circumference was found to be 8-9 hours. Short sleepers (hours sleepers. We found no impact of chronotype or social jetlag on BMI or abdominal obesity after controlling for health, lifestyle, and biological parameters. In our subarctic population, the optimal sleep duration time regarding risk of overweight and abdominal obesity was 8-9 hours, which is one hour longer compared to findings from other studies. Short sleepers had 80% increased risk of being overweight, and men had a doubled risk of having abdominal obesity. We found no associations between chronotype or social jetlag and BMI or abdominal obesity, when we took a range of life-style, health and biological variables into consideration.

  13. Remediation of metal-contaminated land for plant cultivation in the Arctic/subarctic region

    Science.gov (United States)

    Kikuchi, Ryunosuke; Gorbacheva, Tamara T.; Ferreira, Carla S.

    2017-04-01

    Hazardous activities and/or industries involve the use, storage or disposal of hazardous substances. These substances can sometimes contaminate the soil, which can remain contaminated for many years. The metals can have severe effects of on ecosystems. In the Arctic/subarctic regions, the Kola Peninsula (66-70°N and 28°30'-41°30'E) in Russia is one of the seriously polluted regions: close to the nickel-copper smelters, the deposition of metal pollutants has severely damaged the soil and ground vegetation, resulting in a desert area. An area of 10-15 km around the smelters on the Kola Peninsula is today dry sandy and stony ground. A great amount of financial aid is usually required to recover theland. Considering cost performance, a pilot-scale (4ha) field test was carried out to investigate how to apply municipal sewage sludge for rehabilitation of degraded land near the Ni-Cu smelter complex on the Kola Peninsula. The above-mentioned field test for soil rehabilitation was performed while smelting activities were going on; thus, the survey fields were suffering from pollution emitted by the metallurgical industry, and may continue to suffer in the future. After the composting of sewage sludge, the artificial substratum made from the compost was introduced to the test field for the polluted-land remediation, and then willows, birches and grasses were planted on the substratum. The following remarkable points in pollution load were observed between the background field and the rehabilitation test field (e.g. polluted land): (i) the annual precipitation amount of SO42- (5668 g/ha) in the rehabilitation test field was over 5 times greater than that in the background field; (ii) the Pb amount (1.5 g/ha) in the rehabilitation test field was 29 times greater than that in the background field; (iii) the Co amount (10.9 g/ha) in the rehabilitation test field was 54 times greater than that in the background field; (iv) the Cu amount (752 g/ha) in the rehabilitation field

  14. Acceleration of cyanobacterial dominance in north temperate-subarctic lakes during the Anthropocene.

    Science.gov (United States)

    Taranu, Zofia E; Gregory-Eaves, Irene; Leavitt, Peter R; Bunting, Lynda; Buchaca, Teresa; Catalan, Jordi; Domaizon, Isabelle; Guilizzoni, Piero; Lami, Andrea; McGowan, Suzanne; Moorhouse, Heather; Morabito, Giuseppe; Pick, Frances R; Stevenson, Mark A; Thompson, Patrick L; Vinebrooke, Rolf D

    2015-04-01

    Increases in atmospheric temperature and nutrients from land are thought to be promoting the expansion of harmful cyanobacteria in lakes worldwide, yet to date there has been no quantitative synthesis of long-term trends. To test whether cyanobacteria have increased in abundance over the past ~ 200 years and evaluate the relative influence of potential causal mechanisms, we synthesised 108 highly resolved sedimentary time series and 18 decadal-scale monitoring records from north temperate-subarctic lakes. We demonstrate that: (1) cyanobacteria have increased significantly since c. 1800 ce, (2) they have increased disproportionately relative to other phytoplankton, and (3) cyanobacteria increased more rapidly post c. 1945 ce. Variation among lakes in the rates of increase was explained best by nutrient concentration (phosphorus and nitrogen), and temperature was of secondary importance. Although cyanobacterial biomass has declined in some managed lakes with reduced nutrient influx, the larger spatio-temporal scale of sedimentary records show continued increases in cyanobacteria throughout the north temperate-subarctic regions. © 2015 John Wiley & Sons Ltd/CNRS.

  15. Alien Roadside Species More Easily Invade Alpine than Lowland Plant Communities in a Subarctic Mountain Ecosystem

    Science.gov (United States)

    Lembrechts, Jonas J.; Milbau, Ann; Nijs, Ivan

    2014-01-01

    Effects of roads on plant communities are not well known in cold-climate mountain ecosystems, where road building and development are expected to increase in future decades. Knowledge of the sensitivity of mountain plant communities to disturbance by roads is however important for future conservation purposes. We investigate the effects of roads on species richness and composition, including the plant strategies that are most affected, along three elevational gradients in a subarctic mountain ecosystem. We also examine whether mountain roads promote the introduction and invasion of alien plant species from the lowlands to the alpine zone. Observations of plant community composition were made together with abiotic, biotic and anthropogenic factors in 60 T-shaped transects. Alpine plant communities reacted differently to road disturbances than their lowland counterparts. On high elevations, the roadside species composition was more similar to that of the local natural communities. Less competitive and ruderal species were present at high compared with lower elevation roadsides. While the effects of roads thus seem to be mitigated in the alpine environment for plant species in general, mountain plant communities are more invasible than lowland communities. More precisely, relatively more alien species present in the roadside were found to invade into the surrounding natural community at high compared to low elevations. We conclude that effects of roads and introduction of alien species in lowlands cannot simply be extrapolated to the alpine and subarctic environment. PMID:24586947

  16. Unexpected differences in the population genetics of phasmavirids (Bunyavirales) from subarctic ponds.

    Science.gov (United States)

    Ballinger, Matthew J; Medeiros, Andrew S; Qin, Jie; Taylor, Derek J

    2017-01-01

    Little is known of the evolution of RNA viruses in aquatic systems. Here, we assess the genetic connectivity of two bunyaviruses (Kigluaik phantom orthophasmavirus or KIGV and Nome phantom orthophasmavirus or NOMV) with zooplanktonic hosts from subarctic ponds. We expected weak genetic structure among populations as the hosts (phantom midges) have a terrestrial winged dispersal stage. To test whether their respective viruses mirror this structure, we collected and analyzed population datasets from 21 subarctic freshwater ponds and obtained sequences from all four genes in the viral genomes. Prevalence averaged 66 per cent for 514 host specimens and was not significantly different between recently formed thaw ponds and glacial ponds. Unexpectedly, KIGV from older ponds showed pronounced haplotype divergence with little evidence of genetic connectivity. However, KIGV populations from recent thaw ponds appeared to be represented by a closely related haplotype group, perhaps indicating a genotypic dispersal bias. Unlike KIGV, NOMV had modest structure and diversity in recently formed thaw ponds. For each virus, we found elevated genetic diversity relative to the host, but similar population structures to the host. Our results suggest that non-random processes such as virus-host interactions, genotypic bias, and habitat effects differ among polar aquatic RNA viruses.

  17. Evidences of Seasonal Variation in Altimetry Derived Ocean Tides in the Subarctic Ocean

    Directory of Open Access Journals (Sweden)

    Hok Sum Fok

    2013-01-01

    Full Text Available While the barotropic ocean tides in the deep ocean are well modeled to ~2 cm RMS, accurate tidal prediction in the ice-covered polar oceans and near coastal regions remain elusive. A notable reason is that the most accurate satellite altimeters (TOPEX/Jason-1/-2, whose orbits are optimized to minimize the tidal aliasing effect, have spatial coverage limited to largely outside of the polar ocean. Here, we update the assessment of tidal models using 7 contemporary global and regional models, and show that the altimetry sea surface height (SSH anomaly residual after tidal correction is 9 - 12 cm RMS in the Subarctic Ocean. We then address the hypothesis whether plausible evidence of variable tidal signals exist in the seasonally ice-covered Subarctic Ocean, where the sea ice cover is undergoing rapid thinning. We first found a difference in variance reduction for multi-mission altimeter SSH anomaly residuals during the summer and winter seasons, with the residual during winter season 15 - 30% larger than that during the summer season. Experimental seasonal ocean tide solutions derived from satellite altimetry reveals that the recovered winter and summer tidal constituents generally differ by a few cm in amplitude and tens of degrees in phase. Relatively larger seasonal tidal patterns, in particular for M2, S2 and K1 tides, have been identified in the Chukchi Sea study region near eastern Siberia, coincident with the seasonal presence and movement of sea ice.

  18. Population dynamics and life history strategies of the dominant copepods in a sub-arctic Greenlandic fjord

    DEFF Research Database (Denmark)

    Kjellerup, Sanne; Nielsen, Torkel Gissel

    Investigations of the Arctic and Sub-Arctic pelagic food web have previously focused on the copepod genus Calanus, as they often dominate the mesozooplankton community and serve as a lipid rich food source for higher trophic levels. However, if night samples are considered a different food web mi...

  19. A comparison of annual and seasonal carbon dioxide effluxes between subarctic Sweden and high-arctic Svalbard

    DEFF Research Database (Denmark)

    Björkman, Mats P.; Morgner, Elke; Björk, Robert G.

    2010-01-01

    estimated in High-Arctic Adventdalen, Svalbard, and sub-Arctic Latnjajaure, Sweden, using a new trace gas-based method to track real-time diffusion rates through the snow. Summer measurements from snow-free soils were made using a chamber-based method. Measurements were obtained from different snow regimes...

  20. Population dynamics and production of the small copepod Oithona spp. in a subarctic fjord of West Greenland

    DEFF Research Database (Denmark)

    Zamora-Terol, Sara; Kjellerup, Sanne; Swalethorp, Rasmus

    2014-01-01

    The small cyclopoid copepod Oithona is widely occurring in polar areas; however, knowledge of its biology and ecology is very limited. Here, we investigate the population dynamics, vertical distribution, and reproductive characteristics of Oithona spp. from late winter to summer, in a subarctic f...

  1. Variation in genetic traits of the Baltic clam Macoma balthica from a tidal gradient in the subarctic

    NARCIS (Netherlands)

    Hummel, H.; Gunther, C.P.; Bogaards, R.H.; Fedyakov, V.

    1998-01-01

    In a subarctic tidal gradient, strong heterogeneity in genetic traits of the Baltic clam Macoma balthica was found. The heterogeneity was stronger within the intertidal gradient, over a distance of only about GO mi than along a horizontal gradient over a distance of 1200 km in clams from the west

  2. Sub-arctic hydrology and climate change : a case study of the Tana River Basin in Northern Fennoscandia

    NARCIS (Netherlands)

    Dankers, Rutger

    2002-01-01

    The most significant changes in climate, due to the well-known enhanced greenhouse effect, are generally expected to occur at northern high latitudes. Sub-arctic environments, that are dominated by the presence of a seasonal snow cover, may therefore be particularly sensitive to global warming. The

  3. Freeze-thaw regime effects on carbon and nitrogen dynamics in sub-arctic heath tundra mesocosms

    DEFF Research Database (Denmark)

    Grogan, P.; Michelsen, A.; Ambus, P.

    2004-01-01

    of which is realistic of in situ spatial and temporal variation in field conditions, on C and N dynamics in sub-arctic heath tundra mesocosms. In addition, N-15 isotopic label was used to follow the partitioning of a labile N pool between major ecosystem components, both during the freeze-thaw treatments...

  4. Changing times, changing stories: Generational differences in climate change perspectives from four remote indigenous communities in Subarctic Alaska

    Science.gov (United States)

    Nicole M. Herman-Mercer; Elli Matkin; Melinda J. Laituri; Ryan C. Toohey; Maggie Massey; Kelly Elder; Paul F. Schuster; Edda A. Mutter

    2016-01-01

    Indigenous Arctic and Subarctic communities currently are facing a myriad of social and environmental changes. In response to these changes, studies concerning indigenous knowledge (IK) and climate change vulnerability, resiliency, and adaptation have increased dramatically in recent years. Risks to lives and livelihoods are often the focus of adaptation...

  5. Experimentally increased nutrient availability at the permafrost thaw front selectively enhances biomass production of deep-rooting subarctic peatland species

    NARCIS (Netherlands)

    Keuper, Frida; Dorrepaal, Ellen; van Bodegom, Peter M.; van Logtestijn, Richard; Venhuizen, Gemma; van Hal, Jurgen; Aerts, Rien

    2017-01-01

    Climate warming increases nitrogen (N) mineralization in superficial soil layers (the dominant rooting zone) of subarctic peatlands. Thawing and subsequent mineralization of permafrost increases plant-available N around the thaw-front. Because plant production in these peatlands is N-limited, such

  6. Annotated bibliography on soil erosion and erosion control in subarctic and high-latitude regions of North America.

    Science.gov (United States)

    C.W. Slaughter; J.W. Aldrich

    1989-01-01

    This annotated bibliography emphasizes the physical processes of upland soil erosion, prediction of soil erosion and sediment yield, and erosion control. The bibliography is divided into two sections: (1) references specific to Alaska, the Arctic and subarctic, and similar high-latitude settings; and (2) references relevant to understanding erosion, sediment production...

  7. Clinician‐selected Electronic Information Resources do not Guarantee Accuracy in Answering Primary Care Physicians’ Information Needs. A review of: McKibbon, K. Ann, and Douglas B. Fridsma. “Effectiveness of Clinician‐selected Electronic Information Resources for Answering Primary Care Physicians’ Information Needs.” Journal of the American Medical Informatics Association 13.6 (2006: 653‐9.

    Directory of Open Access Journals (Sweden)

    Martha Ingrid Preddie

    2008-03-01

    Full Text Available Objective – To determine if electronic information resources selected by primary care physicians improve their ability to answer simulated clinical questions.Design – An observational study utilizing hour‐long interviews and think‐aloud protocols.Setting – The offices and clinics of primary care physicians in Canada and the United States.Subjects – Twenty‐five primary care physicians of whom 4 were women, 17 were from Canada, 22 were family physicians,and 24 were board certified.Methods – Participants provided responses to 23 multiple‐choice questions. Each physician then chose two questions and looked for the answers utilizing information resources of their own choice. The search processes, chosen resources and search times were noted. These were analyzed along with data on the accuracy of the answers and certainties related to the answer to each clinical question prior to the search.Main results – Twenty‐three physicians sought answers to 46 simulated clinical questions. Utilizing only electronic information resources, physicians spent a mean of 13.0 (SD 5.5 minutes searching for answers to the questions, an average of 7.3(SD 4.0 minutes for the first question and 5.8 (SD 2.2 minutes to answer the second question. On average, 1.8 resources were utilized per question. Resources that summarized information, such as the Cochrane Database of Systematic Reviews, UpToDate and Clinical Evidence, were favored 39.2% of the time, MEDLINE (Ovid and PubMed 35.7%, and Internet resources including Google 22.6%. Almost 50% of the search and retrieval strategies were keyword‐based, while MeSH, subheadings and limiting were used less frequently. On average, before searching physicians answered 10 of 23 (43.5% questions accurately. For questions that were searched using clinician‐selected electronic resources, 18 (39.1% of the 46 answers were accurate before searching, while 19 (42.1% were accurate after searching. The difference of

  8. Analyzing the Academic Research Trends by Using University Digital Resources: A Bibliometric Study of Electronic Commerce in China

    Science.gov (United States)

    Fatima, Anam; Abbas, Asad; Ming, Wan; Zaheer, Ahmad Nawaz; Akhtar, Masood-ul-Hassan

    2017-01-01

    Technology plays a vital role in every field of life especially in business and education. Electronic commerce (EC) begins in the year of 1991 right after internet was introduced for commercial use. It is known to be the 12th five years' plan (2011 to 2015) of Chinese Ministry of Industry and Information Technology. The main "objective"…

  9. Organic matter control on the distribution of arsenic in lake sediments impacted by ~65years of gold ore processing in subarctic Canada.

    Science.gov (United States)

    Galloway, Jennifer M; Swindles, Graeme T; Jamieson, Heather E; Palmer, Michael; Parsons, Michael B; Sanei, Hamed; Macumber, Andrew L; Timothy Patterson, R; Falck, Hendrik

    2017-10-27

    Climate change is profoundly affecting seasonality, biological productivity, and hydrology in high northern latitudes. In sensitive subarctic environments exploitation of mineral resources led to contamination and it is not known how cumulative effects of resource extraction and climate warming will impact ecosystems. Gold mines near Yellowknife, Northwest Territories, subarctic Canada, operated from 1938 to 2004 and released >20,000t of arsenic trioxide (As2O3) to the environment through stack emissions. This release resulted in elevated arsenic concentrations in lake surface waters and sediments relative to Canadian drinking water standards and guidelines for the protection of aquatic life. A meta-analytical approach is used to better understand controls on As distribution in lake sediments within a 30-km radius of historic mineral processing activities. Arsenic concentrations in the near-surface sediments range from 5mg·kg-1 to over 10,000mg·kg-1 (median 81mg·kg-1; n=105). Distance and direction from the historic roaster stack are significantly (p<0.05) related to sedimentary As concentration, with highest As concentrations in sediments within 11km and lakes located downwind. Synchrotron-based μXRF and μXRD confirm the persistence of As2O3 in near surface sediments of two lakes. Labile organic matter (S1) is significantly (p<0.05) related to As and S concentrations in sediments and this relationship is greatest in lakes within 11km from the mine. These relations are interpreted to reflect labile organic matter acting as a substrate for microbial growth and mediation of authigenic precipitation of As-sulphides in lakes close to the historic mine where As concentrations are highest. Continued climate warming is expected to lead to increased biological productivity and changes in organic geochemistry of lake sediments that are likely to play an important role in the mobility and fate of As in aquatic ecosystems. Copyright © 2017 Elsevier B.V. All rights

  10. Responses of non-methane biogenic volatile organic compound emissions to climate change in boreal and subarctic ecosystems

    Energy Technology Data Exchange (ETDEWEB)

    Faubert, P.

    2010-07-01

    Non-methane biogenic volatile organic compound emissions (BVOCs) have important roles in the global atmospheric chemistry but their feedbacks to climate change are still unknown. This thesis reports one of the first estimates of BVOC emissions from boreal and subarctic ecosystems. Most importantly, this thesis assesses the BVOC emission responses to four effects of climate change in these ecosystems: (1) the direct effect of warming, and its indirect effects via (2) water table drawdown, (3) change in the vegetation composition, and (4) enhanced UV-B radiation. BVOC emissions were measured using a conventional chamber method in which the compounds were collected on adsorbent and later analyzed by gas chromatography-mass spectrometry. On a subarctic heath, warming by only 1.9-2.5 degC doubled the monoterpene and sesquiterpene emissions. Such a high increase of BVOC emissions under a conservative warming cannot be predicted by the current models, which underlines the importance of a focus on BVOC emissions from the Subarctic under climate change. On a subarctic peatland, enhanced UV-B did not affect the BVOC emissions but the water table level exerted the major effect. The water table drawdown experimentally applied on boreal peatland microcosms decreased the emissions of monoterpenes and other VOCs (BVOCs with a lifetime>1 d) for the hollows (wet microsites) and that of all BVOC groups for the lawns (moderately wet microsites). The warming treatment applied on the lawn microcosms decreased the isoprene emission. The removal of vascular plants in the hummock (dry microsites) microcosms decreased the emissions of monoterpenes while the emissions between the microcosms covered with Sphagnum moss and bare peat were not different. In conclusion, the results presented in this thesis indicate that climate change has complex effects on the BVOC emissions. These results make a significant contribution to improving the modeling of BVOC emissions for a better understanding of

  11. Share and share alike: encouraging the reuse of academic resources through the Scottish electronic Staff Development Library

    Directory of Open Access Journals (Sweden)

    Lorna M. Campbell

    2001-12-01

    Full Text Available The Scottish electronic Staff Development Library (http://www.sesdl.scotcit.acuk is an ongoing collaborative project involving the Universities of Edinburgh, Paisley and Strathclyde which has been funded by SHEFC as part of their current ScotCIT Programme (http:llwww.scotcit.ac.uk. This project is being developed in response to the increasing demand for flexible, high-quality staff development materials.

  12. FUNCTIONS OF ELECTRONIC LEARNING RESOURCES IN THE PROCESS OF PROFESSION-ORIENTED ORAL SPEECH TRAINING OF FUTURE TEACHERS OF FRENCH LANGUAGE

    Directory of Open Access Journals (Sweden)

    E. Yakovenko-Glushenkova

    2014-07-01

    Full Text Available The article analyzes the use of information and communication technologies in the formation of profession-oriented competence in listening and speaking (monologic, dialogic speech of future teachers of French language in the initial school (I and II years. In order to assure the effective use of ICT in the formation of profession-oriented oral speech competence of future teachers of French language in terms of analyzing, systematizing and summarizing of scientific references the following criterion of the selection of electronic resources as the educational material were identified by the author: relevance (modernity; originality; thoroughness; topicality; informative value; applicability; availability; suitability to communicative needs of future teachers of French language, to their intelligence level and interests; professionally informative significancy; interactivity; contextuality; media intension; social and cultural value; educational value. In turn, the functional use of ICT in formation of profession-oriented oral speech competence of future teachers of French language is represented by the classification, according to which all electronic resources according to their functions are divided into communicative, share, documentation, generative and interactive that is demonstrated by the corresponding examples.

  13. We adapt… but is it good or bad? Locating the political ecology and social-ecological systems debate in reindeer herding in the Swedish Sub-Arctic.

    NARCIS (Netherlands)

    Gallardo, Gloria; Saunders, Fred; Sokolova, Tatiana; Börebäck, Kristina; van Laerhoven, F.S.J.; Kokko, Suvi; Tuvendal, Magnus

    2017-01-01

    Abstract Reindeer herding (RDH) is a livelihood strategy deeply connected to Sami cultural tradition. This article explores the implications of two theoretical and methodological approaches for grasping complex socioenvironmental relationships of RDH in Subarctic Sweden. Based on joint fieldwork,

  14. DECOMPOSITION OF SUB-ARCTIC PLANTS WITH DIFFERING NITROGEN ECONOMIES: A FUNCTIONAL ROLE FOR HEMIPARASITES

    DEFF Research Database (Denmark)

    Quested, H.M.; Cornelissen, J.H.C.; Press, M.C.

    2003-01-01

    in these processes, a comparison of leaf and litter tissue quality, nitrogen (N) resorption, and decomposability with those of a wide range of other plant groups (involving a total of 72 species and including other groups with access to alternative nutrient sources, such as nitrogen fixers and carnivorous plants...... and perennial hemiparasite litter contained, on average, 3.1% and 1.9% N, respectively, compared with 0.77–1.1% for groups without a major alternative N source. Hemiparasite litter lost significantly more mass during decomposition than many, but not all, co-occurring species. These results were combined...... with those of a litter trapping experiment to assess the potential impact of hemiparasites on nutrient cycling. The common sub-arctic hemiparasite Bartsia alpina was estimated to increase the total annual N input from litter to the soil by 42% within 5 cm of its stems, and by 53% across a site with a Bartsia...

  15. Nitrogen fixation, denitrification, and ecosystem nitrogen pools in relation to vegetation development in the Subarctic

    DEFF Research Database (Denmark)

    Sørensen, Pernille Lærkedal; Jonasson, Sven Evert; Michelsen, Anders

    2006-01-01

    Nitrogen (N) fixation, denitrification, and ecosystem pools of nitrogen were measured in three subarctic ecosystem types differing in soil frost-heaving activity and vegetation cover. N2-fixation was measured by the acetylene reduction assay and converted to absolute N ecosystem input by estimates...... measurements of temperature, light, and soil moisture. Nitrogen fixation rate was high with seasonal input estimated at 1.1 g N m2 on frostheaved sorted circles, which was higher than the total plant N content and exceeded estimated annual plant N uptake several-fold but was lower than the microbial N content...... of conversion factors between acetylene reduction and 15N incorporation. One aim was to relate nitrogen fluxes and nitrogen pools to the mosaic of ecosystem types of different stability common in areas of soil frost movements. A second aim was to identify abiotic controls on N2-fixation by simultaneous...

  16. Switching predominance of organic versus inorganic carbon exports from an intermediate-size subarctic watershed

    Science.gov (United States)

    Dornblaser, Mark M.; Striegl, Robert G.

    2015-01-01

    Hydrologic exports of dissolved inorganic and organic carbon (DIC, DOC) reflect permafrost conditions in arctic and subarctic river basins. DIC yields in particular, increase with decreased permafrost extent. We investigated the influence of permafrost extent on DIC and DOC yield in a tributary of the Yukon River, where the upper watershed has continuous permafrost and the lower watershed has discontinuous permafrost. Our results indicate that DIC versus DOC predominance switches with interannual changes in water availability and flow routing in intermediate-size watersheds having mixed permafrost coverage. Large water yield and small concentrations from mountainous headwaters and small water yield and high concentrations from lowlands produced similar upstream and downstream carbon yields. However, DOC export exceeded DIC export during high-flow 2011 while DIC predominated during low-flow 2010. The majority of exported carbon derived from near-surface organic sources when landscapes were wet or frozen and from mineralized subsurface sources when infiltration increased.

  17. Responses of vegetation and soil microbial communities to warming and simulated herbivory in a subarctic heath

    DEFF Research Database (Denmark)

    Rinnan, Riikka; Stark, Sari; Tolvanen, Anne

    2009-01-01

    setup of the International Tundra Experiment (ITEX). Wounding of the dominant deciduous dwarf shrub Vaccinium myrtillus L. to simulate herbivory was carried out annually. We measured vegetation cover in 2003 and 2007, soil nutrient concentrations in 2003 and 2006, soil microbial respiration in 2003......Climate warming increases the cover of deciduous shrubs in arctic ecosystems and herbivory is also known to have a strong influence on the biomass and composition of vegetation. However, research combining herbivory with warming is largely lacking. Our study describes how warming and simulated...... herbivory affect vegetation, soil nutrient concentrations and soil microbial communities after 10-13 years of exposure. 2 We established a factorial warming and herbivory-simulation experiment at a subarctic tundra heath in Kilpisj rvi, Finland, in 1994. Warming was carried out using the open-top chamber...

  18. Chemical pollution in the Arctic and Sub-Arctic marine ecosystems: an overview of current knowledge

    Energy Technology Data Exchange (ETDEWEB)

    Savinova, T.N.; Gabrielsen, G.W.; Falk-Petersen, S.

    1995-02-01

    This report is part of a research project in the framework of the Norwegian-Russian Environmental Cooperation, which was initiated in 1991 to elucidate the present status of environmental contaminants in the highly sensitive Arctic aquatic ecosystem, with special focus on sea birds. Although these ecosystems are the least polluted areas in the world, they are contaminated. The main pathways of contamination into Arctic and sub-Arctic marine ecosystems are atmospheric transport, ocean currents and rivers and in some areas, dumping and ship accidents. A literature survey reveals: (1) there is a lack of data from several trophic levels, (2) previous data are difficult to compare with recent data because of increased quality requirement, (3) not much has been done to investigate the effects of contaminants on the cellular level, at individual or population levels. 389 refs., 7 figs., 32 tabs.

  19. Nonvascular contribution to ecosystem NPP in a subarctic heath during early and late growing season

    DEFF Research Database (Denmark)

    Campioli, Matteo; Samson, Roeland; Michelsen, Anders

    2009-01-01

    Bryophytes and lichens abound in many arctic ecosystems and can contribute substantially to the ecosystem net primary production (NPP). Because of their growth seasonality and their potential for growth out of the growing season peak, bryophyte and lichen contribution to NPP may be particularly...... significant when vascular plants are less active and ecosystems act as a source of carbon (C). To clarify these dynamics, nonvascular and vascular aboveground NPP was compared for a subarctic heath during two contrasting periods of the growing season, viz. early-mid summer and late summer-early autumn....... Nonvascular NPP was determined by assessing shoot biomass increment of three moss species (Hylocomium splendens, Pleurozium schreberi and Dicranum elongatum) and by scaling to ecosystem level using average standing crop. For D. elongatum, these estimates were compared with production estimates obtained from...

  20. Phenological responses of Icelandic subarctic grasslands to short-term and long-term natural soil warming.

    Science.gov (United States)

    Leblans, Niki I W; Sigurdsson, Bjarni D; Vicca, Sara; Fu, Yongshuo; Penuelas, Josep; Janssens, Ivan A

    2017-11-01

    The phenology of vegetation, particularly the length of the growing season (LOS; i.e., the period from greenup to senescence), is highly sensitive to climate change, which could imply potent feedbacks to the climate system, for example, by altering the ecosystem carbon (C) balance. In recent decades, the largest extensions of LOS have been reported at high northern latitudes, but further warming-induced LOS extensions may be constrained by too short photoperiod or unfulfilled chilling requirements. Here, we studied subarctic grasslands, which cover a vast area and contain large C stocks, but for which LOS changes under further warming are highly uncertain. We measured LOS extensions of Icelandic subarctic grasslands along natural geothermal soil warming gradients of different age (short term, where the measurements started after 5 years of warming and long term, i.e., warmed since ≥50 years) using ground-level measurements of normalized difference vegetation index. We found that LOS linearly extended with on average 2.1 days per °C soil warming up to the highest soil warming levels (ca. +10°C) and that LOS had the potential to extend at least 1 month. This indicates that the warming impact on LOS in these subarctic grasslands will likely not saturate in the near future. A similar response to short- and long-term warming indicated a strong physiological control of the phenological response of the subarctic grasslands to warming and suggested that genetic adaptations and community changes were likely of minor importance. We conclude that the warming-driven extension of the LOSs of these subarctic grasslands did not saturate up to +10°C warming, and hence that growing seasons of high-latitude grasslands are likely to continue lengthening with future warming (unless genetic adaptations or species shifts do occur). This persistence of the warming-induced extension of LOS has important implications for the C-sink potential of subarctic grasslands under climate

  1. A systems approach to understanding subarctic critical zone changes in a warming climate (Invited)

    Science.gov (United States)

    Rich, V. I.; McCalley, C. K.; Woodcroft, B. J.; Kim, E.; Hodgkins, S. B.; Tfaily, M. M.; Wehr, R. A.; Logan, T.; Jones, R.; Mondav, R.; Hurst, G.; Verberkmoes, N.; Li, C.; Frolking, S. E.; Crill, P. M.; Chanton, J.; Saleska, S. R.; Tyson, G. W.

    2013-12-01

    Climate change is dramatically altering the subarctic and Arctic Critical Zone. Permafrost, which currently holds approximately one third of global soil carbon in a relatively unavailable form, is predicted to be virtually eliminated by the end of the century. One endpoint for permafrost habitat thaw is wetlands, which are a major source of the microbially-produced greenhouse gas methane. This creates a potentially large positive feedback to climate change. Our team is using a systems approach spanning diverse geochemical (high-resolution greenhouse gas isofluxes and soil/peat geochemistry) and molecular (16S rRNA gene amplicon, metagenomic and metaproteomic sequencing) measurements to track parallel changes in carbon cycling and in situ microbiology across a natural permafrost thaw gradient. Thaw at this site results in a three-stage habitat shift from ericaceous shrubs, to peat moss, to sedges, concomitant with a substantial increase in methane emissions. Isotopically, emitted methane shifts along the thaw gradient away from hydrogenotrophic methane production, in parallel with the appearance of acetoclastic methanogens in the microbial community. Community data have also revealed the presence of a novel, highly-active methanogen from the euryarchaeal lineage Rice Cluster-II, dubbed Candidatus Methanoflorens stordalenmirensis. Its ';species' is present in numerous other global wetland datasets, has the genomic capacity (inferred from its population genome) for hydrogenotrophic methanogenesis, and was the highest environmental correlate of emitted methane's isotopic signature. In situ community global protein expression profiles (i.e. metaproteomes) revealed that it strongly expresses its hydrogentrophic methanogensis genes, and that methanogenesis is a dominant signal in the overall community proteome. As we generate a portrait of how thaw impacts this major subarctic critical zone habitat, we are working with ecosystem process modelers to integrate new

  2. Functional Redundancy Facilitates Resilience of Subarctic Phytoplankton Assemblages toward Ocean Acidification and High Irradiance

    Directory of Open Access Journals (Sweden)

    Clara J. M. Hoppe

    2017-07-01

    Full Text Available In order to understand how ocean acidification (OA and enhanced irradiance levels might alter phytoplankton eco-physiology, productivity and species composition, we conducted an incubation experiment with a natural plankton assemblage from sub-surface Subarctic waters (Davis Strait, 63°N. The phytoplankton assemblage was exposed to 380 and 1,000 μatm pCO2 at both 15 and 35% surface irradiance over 2 weeks. The incubations were monitored and characterized in terms of their photo-physiology, biomass stoichiometry, primary production and dominant phytoplankton species. We found that the phytoplankton assemblage exhibited pronounced high-light stress in the first days of the experiment (20–30% reduction in photosynthetic efficiency, Fv/Fm. This stress signal was more pronounced when grown under OA and high light, indicating interactive effects of these environmental variables. Primary production in the high light treatments was reduced by 20% under OA compared to ambient pCO2 levels. Over the course of the experiment, the assemblage fully acclimated to the applied treatments, achieving similar bulk characteristics (e.g., net primary production and elemental stoichiometry under all conditions. We did, however, observe a pCO2-dependent shift in the dominant diatom species, with Pseudonitzschia sp. dominating under low and Fragilariopsis sp. under high pCO2 levels. Our results indicate an unexpectedly high level of resilience of Subarctic phytoplankton to OA and enhanced irradiance levels. The co-occurring shift in dominant species suggests functional redundancy to be an important, but so-far largely overlooked mechanism for resilience toward climate change.

  3. Utilization of iron bound to strong organic ligands by plankton communities in the subarctic Pacific Ocean

    Science.gov (United States)

    Maldonado, Maria T.; Price, Neil M.

    1999-11-01

    Experiments were conducted along a coastal-oceanic transect in the NE subarctic Pacific to examine acquisition of organically complexed Fe by autotrophic and heterotrophic plankton. During short-term experiments, plankton took up Fe bound to the siderophores desferrioxamine B and E, microbial Fe chelates with a high affinity for Fe. Uptake occurred in all size fractions: 0.2-1, 1-3, and >3 μm. Heterotrophic bacteria had higher Fe : C ratios (1.5 to 2 times) than phytoplankton, and accounted for 70±8% of the total Fe uptake by the community (mol Fe ml -1 h -1). This latter result was partially explained by the higher C biomass of bacteria, but was not related to their productivity. Carbon-specific uptake rates of Fe were also faster (1.6±1.5 times) in bacteria than phytoplankton. When the rates were normalized per cell surface area, however, phytoplankton were observed to transport Fe at a rate more than 30 times that of bacteria. Large phytoplankton greater than 3 μm reduced Fe bound to organic ligands extracellularly. Their Fe : C ratios and rates of uptake and reduction of organically bound Fe were very similar at all stations along the transect and were characteristic of Fe-stressed phytoplankton. A strong seasonal trend of Fe uptake and reduction was apparent. The results suggest that heterotrophic bacteria are responsible for a large fraction of dissolved Fe uptake and that the indigenous plankton of the subarctic Pacific are able to acquire Fe bound to strong organic ligands, the predominant form of dissolved Fe in the sea.

  4. Variable Trends in High Peak Flow Generation Across the Swedish Sub-Arctic

    Science.gov (United States)

    Matti, B.; Dahlke, H. E.; Lyon, S. W.

    2015-12-01

    There is growing concern about increased frequency and severity of floods and droughts globally in recent years. Improving knowledge on the complexity of hydrological systems and their interactions with climate is essential to be able to determine drivers of these extreme events and to predict changes in these drivers under altered climate conditions. This is particularly true in cold regions such as the Swedish Sub-Arctic where independent shifts in both precipitation and temperature can have significant influence on extremes. This study explores changes in the magnitude and timing of the annual maximum daily flows in 18 Swedish sub-arctic catchments. The Mann-Kendall trend test was used to estimate changes in selected hydrological signatures. Further, a flood frequency analysis was conducted by fitting a Gumbel (Extreme Value type I) distribution whereby selected flood percentiles were tested for stationarity using a generalized least squares regression approach. Our results showed that hydrological systems in cold climates have complex, heterogeneous interactions with climate. Shifts from a snowmelt-dominated to a rainfall-dominated flow regime were evident with all significant trends pointing towards (1) lower flood magnitudes in the spring flood; (2) earlier flood occurrence; (3) earlier snowmelt onset; and (4) decreasing mean summer flows. Decreasing trends in flood magnitude and mean summer flows suggest permafrost thawing and are in agreement with the increasing trends in annual minimum flows. Trends in the selected flood percentiles showed an increase in extreme events over the entire period of record, while trends were variable under shorter periods. A thorough uncertainty analysis emphasized that the applied trend test is highly sensitive to the period of record considered. As such, no clear overall regional pattern could be determined suggesting that how catchments are responding to changes in climatic drivers is strongly influenced by their physical

  5. Utility of the electronic information resource UpToDate for clinical decision-making at bedside rounds.

    Science.gov (United States)

    Phua, J; See, K C; Khalizah, H J; Low, S P; Lim, T K

    2012-02-01

    Clinical questions often arise at daily hospital bedside rounds. Yet, little information exists on how the search for answers may be facilitated. The aim of this prospective study was, therefore, to evaluate the overall utility, including the feasibility and usefulness of incorporating searches of UpToDate, a popular online information resource, into rounds. Doctors searched UpToDate for any unresolved clinical questions during rounds for patients in general medicine and respiratory wards, and in the medical intensive care unit of a tertiary teaching hospital. The nature of the questions and the results of the searches were recorded. Searches were deemed feasible if they were completed during the rounds and useful if they provided a satisfactory answer. A total of 157 UpToDate searches were performed during the study period. Questions were raised by all ranks of clinicians from junior doctors to consultants. The searches were feasible and performed immediately during rounds 44% of the time. Each search took a median of three minutes (first quartile: two minutes, third quartile: five minutes). UpToDate provided a useful and satisfactory answer 75% of the time, a partial answer 17% of the time and no answer 9% of the time. It led to a change in investigations, diagnosis or management 37% of the time, confirmed what was originally known or planned 38% of the time and had no effect 25% of the time. Incorporating UpToDate searches into daily bedside rounds was feasible and useful in clinical decision-making.

  6. The transformation and fate of sub-Arctic microphytobenthos carbon revealed through 13C-labeling

    DEFF Research Database (Denmark)

    Oakes, Joanne M.; Rysgaard, Søren; Glud, Ronnie N.

    2016-01-01

    Cm(-2)h(-1)) was comparable to that reported for temperate regions. Some of the C-13 fixed by sub-Arctic MPB was rapidly (within 0.5 d) transferred to deeper sediments (below 2 cm), but most was retained within surface sediments (>70.2% of the C-13 present at any time during the study). At any time, MPB...... accounted for49.8% of this C-13. The C-13 content of sediment organic carbon declined over time, but>31% of the C-13 fixed within the first tidal cycle remained after 31 d, suggesting that sub-Arctic MPB may contribute to coastal carbon retention during the productive season. Over 21 d, 10.6% of the fixed C...... conditions are more important than climate differences for determining the processing and fate of MPB-C....

  7. Analysis of the boreal forest-tundra ecotone: A test of AVIRIS capabilities in the Eastern Canadian subarctic

    Science.gov (United States)

    Goward, Samuel N.; Petzold, Donald E.

    1989-01-01

    A comparison was conducted between ground reflectance spectra collected in Schefferville, Canada and imaging spectrometer observations acquired by the AVIRIS sensor in a flight of the ER-2 Aircraft over the same region. The high spectral contrasts present in the Canadian Subarctic appeared to provide an effective test of the operational readiness of the AVIRIS sensor. Previous studies show that in this location various land cover materials possess a wide variety of visible/near infrared reflectance properties. Thus, this landscape served as an excellent test for the sensing variabilities of the newly developed AVIRIS sensor. An underlying hypothesis was that the unique visible/near infrared spectral reflectance patterns of Subarctic lichens could be detected from high altitudes by this advanced imaging spectrometer. The relation between lichen occurrence and boreal forest-tundra ecotone dynamics was investigated.

  8. Potential macro-detritivore range expansion into the subarctic stimulates litter decomposition: a new positive feedback mechanism to climate change?

    Science.gov (United States)

    van Geffen, Koert G; Berg, Matty P; Aerts, Rien

    2011-12-01

    As a result of low decomposition rates, high-latitude ecosystems store large amounts of carbon. Litter decomposition in these ecosystems is constrained by harsh abiotic conditions, but also by the absence of macro-detritivores. We have studied the potential effects of their climate change-driven northward range expansion on the decomposition of two contrasting subarctic litter types. Litter of Alnus incana and Betula pubescens was incubated in microcosms together with monocultures and all possible combinations of three functionally different macro-detritivores (the earthworm Lumbricus rubellus, isopod Oniscus asellus, and millipede Julus scandinavius). Our results show that these macro-detritivores stimulated decomposition, especially of the high-quality A. incana litter and that the macro-detritivores tested differed in their decomposition-stimulating effects, with earthworms having the largest influence. Decomposition processes increased with increasing number of macro-detritivore species, and positive net diveristy effects occurred in several macro-detritivore treatments. However, after correction for macro-detritivore biomass, all interspecific differences in macro-detritivore effects, as well as the positive effects of species number on subarctic litter decomposition disappeared. The net diversity effects also appeared to be driven by variation in biomass, with a possible exception of net diversity effects in mass loss. Based on these results, we conclude that the expected climate change-induced range expansion of macro-detritivores into subarctic regions is likely to result in accelerated decomposition rates. Our results also indicate that the magnitude of macro-detritivore effects on subarctic decomposition will mainly depend on macro-detritivore biomass, rather than on macro-detritivore species number or identity.

  9. Potential macro-detritivore range expansion into the subarctic stimulates litter decomposition: a new positive feedback mechanism to climate change?

    OpenAIRE

    Geffen, van, LCMM; Berg, M.P.; Aerts, R.

    2011-01-01

    As a result of low decomposition rates, high-latitude ecosystems store large amounts of carbon. Litter decomposition in these ecosystems is constrained by harsh abiotic conditions, but also by the absence of macro-detritivores. We have studied the potential effects of their climate change-driven northward range expansion on the decomposition of two contrasting subarctic litter types. Litter of Alnus incana and Betula pubescens was incubated in microcosms together with monocultures and all pos...

  10. Changing times, changing stories: Generational differences in climate change perspectives from four remote indigenous communities in Subarctic Alaska

    Science.gov (United States)

    Herman-Mercer, Nicole M.; Matkin, Elli; Laituri, Melinda J.; Toohey, Ryan C; Massey, Maggie; Kelly Elder,; Schuster, Paul F.; Mutter, Edda A.

    2016-01-01

    Indigenous Arctic and Subarctic communities currently are facing a myriad of social and environmental changes. In response to these changes, studies concerning indigenous knowledge (IK) and climate change vulnerability, resiliency, and adaptation have increased dramatically in recent years. Risks to lives and livelihoods are often the focus of adaptation research; however, the cultural dimensions of climate change are equally important because cultural dimensions inform perceptions of risk. Furthermore, many Arctic and Subarctic IK climate change studies document observations of change and knowledge of the elders and older generations in a community, but few include the perspectives of the younger population. These observations by elders and older generations form a historical baseline record of weather and climate observations in these regions. However, many indigenous Arctic and Subarctic communities are composed of primarily younger residents. We focused on the differences in the cultural dimensions of climate change found between young adults and elders. We outlined the findings from interviews conducted in four indigenous communities in Subarctic Alaska. The findings revealed that (1) intergenerational observations of change were common among interview participants in all four communities, (2) older generations observed more overall change than younger generations interviewed by us, and (3) how change was perceived varied between generations. We defined “observations” as the specific examples of environmental and weather change that were described, whereas “perceptions” referred to the manner in which these observations of change were understood and contextualized by the interview participants. Understanding the differences in generational observations and perceptions of change are key issues in the development of climate change adaptation strategies.

  11. Changing times, changing stories: generational differences in climate change perspectives from four remote indigenous communities in Subarctic Alaska

    Directory of Open Access Journals (Sweden)

    Nicole M. Herman-Mercer

    2016-09-01

    Full Text Available Indigenous Arctic and Subarctic communities currently are facing a myriad of social and environmental changes. In response to these changes, studies concerning indigenous knowledge (IK and climate change vulnerability, resiliency, and adaptation have increased dramatically in recent years. Risks to lives and livelihoods are often the focus of adaptation research; however, the cultural dimensions of climate change are equally important because cultural dimensions inform perceptions of risk. Furthermore, many Arctic and Subarctic IK climate change studies document observations of change and knowledge of the elders and older generations in a community, but few include the perspectives of the younger population. These observations by elders and older generations form a historical baseline record of weather and climate observations in these regions. However, many indigenous Arctic and Subarctic communities are composed of primarily younger residents. We focused on the differences in the cultural dimensions of climate change found between young adults and elders. We outlined the findings from interviews conducted in four indigenous communities in Subarctic Alaska. The findings revealed that (1 intergenerational observations of change were common among interview participants in all four communities, (2 older generations observed more overall change than younger generations interviewed by us, and (3 how change was perceived varied between generations. We defined "observations" as the specific examples of environmental and weather change that were described, whereas "perceptions" referred to the manner in which these observations of change were understood and contextualized by the interview participants. Understanding the differences in generational observations and perceptions of change are key issues in the development of climate change adaptation strategies.

  12. Relationships between ecosystem metabolism, benthic macroinvertebrate densities, and environmental variables in a sub-arctic Alaskan river

    Science.gov (United States)

    Benson, Emily R.; Wipfli, Mark S.; Clapcott, Joanne E.; Hughes, Nicholas F.

    2013-01-01

    Relationships between environmental variables, ecosystem metabolism, and benthos are not well understood in sub-arctic ecosystems. The goal of this study was to investigate environmental drivers of river ecosystem metabolism and macroinvertebrate density in a sub-arctic river. We estimated primary production and respiration rates, sampled benthic macroinvertebrates, and monitored light intensity, discharge rate, and nutrient concentrations in the Chena River, interior Alaska, over two summers. We employed Random Forests models to identify predictor variables for metabolism rates and benthic macroinvertebrate density and biomass, and calculated Spearman correlations between in-stream nutrient levels and metabolism rates. Models indicated that discharge and length of time between high water events were the most important factors measured for predicting metabolism rates. Discharge was the most important variable for predicting benthic macroinvertebrate density and biomass. Primary production rate peaked at intermediate discharge, respiration rate was lowest at the greatest time since last high water event, and benthic macroinvertebrate density was lowest at high discharge rates. The ratio of dissolved inorganic nitrogen to soluble reactive phosphorus ranged from 27:1 to 172:1. We found that discharge plays a key role in regulating stream ecosystem metabolism, but that low phosphorous levels also likely limit primary production in this sub-arctic stream.

  13. Export production in the subarctic North Pacific over the last 800 kyrs: No evidence for iron fertilization?

    Science.gov (United States)

    Kienast, S.S.; Hendy, I.L.; Crusius, J.; Pedersen, Thomas F.; Calvert, S.E.

    2004-01-01

    The subarctic North Pacific is a high nitrate-low chlorophyll (HNLC) region, where phytoplankton growth rates, especially those of diatoms, are enhanced when micro-nutrient Fe is added. Accordingly, it has been suggested that glacial Fe-laden dust might have increased primary production in this region. This paper reviews published palaeoceanographic records of export production over the last 800 kyrs from the open North Pacific (north of ???35??N). We find different patterns of export production change over time in the various domains of the North Pacific (NW and NE subarctic gyres, the marginal seas and the transition zone). However, there is no compelling evidence for an overall increase in productivity during glacials in the subarctic region, challenging the paradigm that dust-born Fe fertilization of this region has contributed to the glacial draw down of atmospheric CO2. Potential reasons for the lack of increased glacial export production include the possibility that Fe-fertilization rapidly drives the ecosystem towards limitation by another nutrient. This effect would have been exacerbated by an even more stable mixed layer compared to today. ?? The Oceanographic Society of Japan.

  14. Comprehensive evaluation of electronic medical record system use and user satisfaction at five low-resource setting hospitals in ethiopia.

    Science.gov (United States)

    Tilahun, Binyam; Fritz, Fleur

    2015-05-25

    Electronic medical record (EMR) systems are increasingly being implemented in hospitals of developing countries to improve patient care and clinical service. However, only limited evaluation studies are available concerning the level of adoption and determinant factors of success in those settings. The objective of this study was to assess the usage pattern, user satisfaction level, and determinants of health professional's satisfaction towards a comprehensive EMR system implemented in Ethiopia where parallel documentation using the EMR and the paper-based medical records is in practice. A quantitative, cross-sectional study design was used to assess the usage pattern, user satisfaction level, and determinant factors of an EMR system implemented in Ethiopia based on the DeLone and McLean model of information system success. Descriptive statistical methods were applied to analyze the data and a binary logistic regression model was used to identify determinant factors. Health professionals (N=422) from five hospitals were approached and 406 responded to the survey (96.2% response rate). Out of the respondents, 76.1% (309/406) started to use the system immediately after implementation and user training, but only 31.7% (98/309) of the professionals reported using the EMR during the study (after 3 years of implementation). Of the 12 core EMR functions, 3 were never used by most respondents, and they were also unaware of 4 of the core EMR functions. It was found that 61.4% (190/309) of the health professionals reported over all dissatisfaction with the EMR (median=4, interquartile range (IQR)=1) on a 5-level Likert scale. Physicians were more dissatisfied (median=5, IQR=1) when compared to nurses (median=4, IQR=1) and the health management information system (HMIS) staff (median=2, IQR=1). Of all the participants, 64.4% (199/309) believed that the EMR had no positive impact on the quality of care. The participants indicated an agreement with the system and information

  15. Association of climatic factors with infectious diseases in the Arctic and subarctic region – a systematic review

    Directory of Open Access Journals (Sweden)

    Christina Hedlund

    2014-07-01

    Full Text Available Background: The Arctic and subarctic area are likely to be highly affected by climate change, with possible impacts on human health due to effects on food security and infectious diseases. Objectives: To investigate the evidence for an association between climatic factors and infectious diseases, and to identify the most climate-sensitive diseases and vulnerable populations in the Arctic and subarctic region. Methods: A systematic review was conducted. A search was made in PubMed, with the last update in May 2013. Inclusion criteria included human cases of infectious disease as outcome, climate or weather factor as exposure, and Arctic or subarctic areas as study origin. Narrative reviews, case reports, and projection studies were excluded. Abstracts and selected full texts were read and evaluated by two independent readers. A data collection sheet and an adjusted version of the SIGN methodology checklist were used to assess the quality grade of each article. Results: In total, 1953 abstracts were initially found, of which finally 29 articles were included. Almost half of the studies were carried out in Canada (n=14, the rest from Sweden (n=6, Finland (n=4, Norway (n=2, Russia (n=2, and Alaska, US (n=1. Articles were analyzed by disease group: food- and waterborne diseases, vector-borne diseases, airborne viral- and airborne bacterial diseases. Strong evidence was found in our review for an association between climatic factors and food- and waterborne diseases. The scientific evidence for a link between climate and specific vector- and rodent-borne diseases was weak due to that only a few diseases being addressed in more than one publication, although several articles were of very high quality. Air temperature and humidity seem to be important climatic factors to investigate further for viral- and bacterial airborne diseases, but from our results no conclusion about a causal relationship could be drawn. Conclusions: More studies of high quality

  16. Fine-scale spatial and interannual cadmium isotope variability in the subarctic northeast Pacific

    Science.gov (United States)

    Janssen, D. J.; Abouchami, W.; Galer, S. J. G.; Cullen, J. T.

    2017-08-01

    We present dissolved cadmium (Cd) concentrations, [Cd], and stable isotope compositions, ε 112 / 110Cd, in high-resolution depth profiles from five stations along the Line P transect in the subarctic northeast Pacific Ocean. In addition to profiles collected in 2012, subsurface isopycnal samples and surface samples were collected in 2013 and 2014 respectively, providing both temporal and spatial coverage. Surface waters are characterized by Cd depletion relative to phosphate (4 3-PO) compared to deepwater 4 -3Cd:PO, and high inferred remineralization ratios in the nutricline (0.45nmolμmol-1) are observed, consistent with Cd enrichment relative to phosphorus (P) in surface-derived biogenic particles. The correlation between Cd and 4 3-PO weakens at depths where oxygen is highly depleted as shown by local minima in dissolved [Cd] and the tracer Cd*. The decoupling, which is driven by a deficit of Cd relative to 4 3-PO, appears consistent with the recent hypothesis of dissolved Cd removal in oxygen-depleted regions by insoluble metal sulfide formation. Dissolved ε 112 / 110Cd indicates a biologically driven fractionation in surface waters with more positive (heavy) values in the upper water column and lower (light) values in deeper waters. The highest ε 112 / 110Cd observed in our sample set (5.19 ± 0.23) is comparable to observations from the Southern Ocean but is significantly lighter than maximum reported surface values from the subtropical North Pacific of ε 112 / 110Cd ≥ 15. A global compilation of low [Cd] surface water shows similar differences in maximum ε 112 / 110Cd. A surface water intercalibration should be prioritized to help determine if these differences at low [Cd] reflect true physical or biological variability or are due to analytical artefacts. Surface samples from the 2012 sampling campaign fit a closed-system Rayleigh fractionation model; however, surface waters sampled in 2014 had much lower [Cd] with relatively constant ε 112 / 110Cd

  17. Randomized Controlled Trial of Electronic Care Plan Alerts and Resource Utilization by High Frequency Emergency Department Users with Opioid Use Disorder

    Directory of Open Access Journals (Sweden)

    Niels Rathlev, MD

    2016-01-01

    Full Text Available Introduction: There is a paucity of literature supporting the use of electronic alerts for patients with high frequency emergency department (ED use. We sought to measure changes in opioid prescribing and administration practices, total charges and other resource utilization using electronic alerts to notify providers of an opioid-use care plan for high frequency ED patients. Methods: This was a randomized, non-blinded, two-group parallel design study of patients who had 1 opioid use disorder and 2 high frequency ED use. Three affiliated hospitals with identical electronic health records participated. Patients were randomized into “Care Plan” versus “Usual Care groups”. Between the years before and after randomization, we compared as primary outcomes the following: 1 opioids (morphine mg equivalents prescribed to patients upon discharge and administered to ED and inpatients; 2 total medical charges, and the numbers of; 3 ED visits, 4 ED visits with advanced radiologic imaging (computed tomography [CT] or magnetic resonance imaging [MRI] studies, and 5 inpatient admissions. Results: A total of 40 patients were enrolled. For ED and inpatients in the “Usual Care” group, the proportion of morphine mg equivalents received in the post-period compared with the pre-period was 15.7%, while in the “Care Plan” group the proportion received in the post-period compared with the pre-period was 4.5% (ratio=0.29, 95% CI [0.07-1.12]; p=0.07. For discharged patients in the “Usual Care” group, the proportion of morphine mg equivalents prescribed in the post-period compared with the pre-period was 25.7% while in the “Care Plan” group, the proportion prescribed in the post-period compared to the pre-period was 2.9%. The “Care Plan” group showed an 89% greater proportional change over the periods compared with the “Usual Care” group (ratio=0.11, 95% CI [0.01-0.092]; p=0.04. Care plans did not change the total charges, or, the numbers

  18. Complex population structure of Lyme borreliosis group spirochete Borrelia garinii in subarctic Eurasia.

    Science.gov (United States)

    Comstedt, Pär; Asokliene, Loreta; Eliasson, Ingvar; Olsen, Björn; Wallensten, Anders; Bunikis, Jonas; Bergström, Sven

    2009-06-09

    Borrelia garinii, a causative agent of Lyme borreliosis in Europe and Asia, is naturally maintained in marine and terrestrial enzootic cycles, which primarily involve birds, including seabirds and migratory passerines. These bird groups associate with, correspondingly, Ixodes uriae and Ixodes ricinus ticks, of which the latter species may bite and transmit the infection to humans. Studies of the overlap between these two natural cycles of B. garinii have been limited, in part due to the absence of representative collections of this spirochete's samples, as well as of the lack of reliable measure of the genetic heterogeneity of its strains. As a prerequisite for understanding the epidemiological correlates of the complex maintenance of B. garinii, the present study sought to assess the diversity and phylogenetic relationships of this species' strains from its natural hosts and patients with Lyme borreliosis from subarctic Eurasia. We used sequence typing of the partial rrs-rrl intergenic spacer (IGS) of archived and prospective samples of B. garinii from I. uriae ticks collected predominantly on Commander Islands in North Pacific, as well as on the islands in northern Sweden and arctic Norway. We also typed B. garinii samples from patients with Lyme borreliosis and I. ricinus ticks infesting migratory birds in southern Sweden, or found questing in selected sites on the islands in the Baltic Sea and Lithuania. Fifty-two (68%) of 77 B. garinii samples representing wide geographical range and associated with I. ricinus and infection of humans contributed 12 (60%) of total 20 identified IGS variants. In contrast, the remaining 25 (32%) samples recovered from I. uriae ticks from a few islands accounted for as many as 10 (50%) IGS types, suggesting greater local diversity of B. garinii maintained by seabirds and their ticks. Two IGS variants of the spirochete in common for both tick species were found in I. ricinus larvae from migratory birds, an indication that B

  19. Complex population structure of Lyme borreliosis group spirochete Borrelia garinii in subarctic Eurasia.

    Directory of Open Access Journals (Sweden)

    Pär Comstedt

    Full Text Available Borrelia garinii, a causative agent of Lyme borreliosis in Europe and Asia, is naturally maintained in marine and terrestrial enzootic cycles, which primarily involve birds, including seabirds and migratory passerines. These bird groups associate with, correspondingly, Ixodes uriae and Ixodes ricinus ticks, of which the latter species may bite and transmit the infection to humans. Studies of the overlap between these two natural cycles of B. garinii have been limited, in part due to the absence of representative collections of this spirochete's samples, as well as of the lack of reliable measure of the genetic heterogeneity of its strains. As a prerequisite for understanding the epidemiological correlates of the complex maintenance of B. garinii, the present study sought to assess the diversity and phylogenetic relationships of this species' strains from its natural hosts and patients with Lyme borreliosis from subarctic Eurasia. We used sequence typing of the partial rrs-rrl intergenic spacer (IGS of archived and prospective samples of B. garinii from I. uriae ticks collected predominantly on Commander Islands in North Pacific, as well as on the islands in northern Sweden and arctic Norway. We also typed B. garinii samples from patients with Lyme borreliosis and I. ricinus ticks infesting migratory birds in southern Sweden, or found questing in selected sites on the islands in the Baltic Sea and Lithuania. Fifty-two (68% of 77 B. garinii samples representing wide geographical range and associated with I. ricinus and infection of humans contributed 12 (60% of total 20 identified IGS variants. In contrast, the remaining 25 (32% samples recovered from I. uriae ticks from a few islands accounted for as many as 10 (50% IGS types, suggesting greater local diversity of B. garinii maintained by seabirds and their ticks. Two IGS variants of the spirochete in common for both tick species were found in I. ricinus larvae from migratory birds, an indication

  20. There is a Relationship between Resource Expenditures and Reference Transactions in Academic Libraries. A Review of: Dubnjakovic, A. (2012. Electronic resource expenditure and the decline in reference transaction statistics in academic libraries. Journal of Academic Librarianship, 38(2, 94-100. doi:10.1016/j.acalib.2012.01.001

    Directory of Open Access Journals (Sweden)

    Annie M. Hughes

    2013-03-01

    Full Text Available Objective – To provide an analysis of the impact of expenditures on electronic resourcesand gate counts on the increase or decrease in reference transactions.Design – Analysis of results of existing survey data from the National Center for Educational Statistics (NCES 2006 Academic Library Survey(ALS.Setting – Academic libraries in the United States.Subjects – 3925 academic library respondents.Methods – The author chose to use survey data collected from the 2006 ALS conducted bythe NCES. The survey included data on various topics related to academic libraries, but in the case of this study, the author chose to analyze three of the 193 variables included. The three variables: electronic books expenditure, computer hardware and software, and expenditures on bibliographic utilities, were combined into one variable called electronic resource expenditure. Gate counts were also considered as a variable. Electronic resource expenditure was also split as a variable into three groups: low, medium, and high. Multiple regression analysis and general linear modeling, along with tests of reliability, were employed. Main Results – The author determined that low, medium, and high spenders with regard to electronic resources exhibited differences in gate counts, and gate counts have an effect on reference transactions in any given week. Gate counts tend to not have much of an effect on reference transactions for the higher spenders, and higher spenders tend to have a higher number of reference transactions overall. Low spenders have lower gate counts and also a lower amount of reference transactions.Conclusion – The findings from this study show that academic libraries spending more on electronic resources also tend to have an increase with regard to reference transactions. The author also concludes that library spaces are no longer the determining factor with regard to number of reference transactions. Spending more on electronic resources is

  1. Global application of disorders of sex development-related electronic resources: e-learning, e-consultation and e-information sharing.

    Science.gov (United States)

    Muscarella, Miriam; Kranenburg-van Koppen, Laura; Grijpink-van den Biggelaar, Kalinka; Drop, Stenvert L S

    2014-01-01

    The past 20 years have seen proliferation of electronic (e) resources that promote improved understanding of disorders of sex development (DSD): e-learning for physicians and trainees, e-consultation between clinicians, and e-information for families and affected individuals. Recent e-learning advances have emerged from the European Society for Pediatric Endocrinology's online learning portal for current physicians and trainees. Developed with attention to developing clinical competencies incorporating learning theory, and presenting material that represents international best practice, this e-learning portal offers advances in training, making information more accessible for clinicians and trainees. Multiple levels of instruction, authentic case examples, collaborative forums for physicians and trainees, individualized feedback and user-friendly tools represent advances in trainee and physician learning that can take place in any location. e-consultation is an emerging tool that aims to connect physicians with specialists experienced in DSD care. Although it faces logistical challenges, e-consultation carries the potential to improve DSD care, especially in remote areas with limited access to DSD specialists. e-information for families and patients of all ages is widely accessible online, often with focus on DSD biology, medical care, and psychological and social support. e-information tools aid self-management and support of those affected by DSD. Efforts to improve these resources should aim to map information to individual users, incorporate optimally clear nomenclature, and continue as a 'shared enterprise' of clinicians, affected individuals, families and researchers. Improving the quality of DSD-related e-learning and e-information and developing e-consultation carries the potential to transform DSD care and support for patients, families and physicians worldwide. © 2014 S. Karger AG, Basel.

  2. Late Holocene climate and chemical change at high latitudes: case studies from contaminated sites in subarctic and arctic Canada

    Science.gov (United States)

    Galloway, Jennifer M.; Cooney, Darryl; Crann, Carley; Falck, Hendrik; Howell, Dana; Jamieson, Heather; Macumber, Andrew; Nasser, Nawaf; Palmer, Michael; Patterson, R. Timothy; Parsons, Michael; Roe, Helen M.; Sanei, Hamed; Spence, Christopher; Stavinga, Drew; Swindles, Graeme T.

    2015-04-01

    Climate variability is occurring at unprecedented rates in northern regions of the Earth, yet little is known about the nature of this variability or its influence on chemical cycling in the environment, particularly in areas with a legacy of contamination from past resource development. We use a paleolimnological approach to reconstruct climate and chemical change over centuries and millennia at two sites in the mineral-rich Slave Geologic Province in Northern Canada heavily impacted by gold mining. Such an approach is necessary to define the cumulative effects of climate change on metal loading and can be used to define anthropogenic release of contaminants to support policy and regulation due to a paucity of long-term monitoring data. The Seabridge Gold Inc. Courageous Lake project is a gold exploration project 240 km north of Yellowknife in the central Northwest Territories, Arctic Canada. Mining operations took place within the claim area at the Tundra (1964-1968) and Salmita (1983-1987) mines. Giant Mine is located in the subarctic near the City of Yellowknife and mining at this site represents the longest continuous gold mining operation in Canada (1938 to 2002). Due to the refractory mineralogy of ore, gold was extracted from arsenopyrite by roasting, which resulted in release of substantial quantities of highly toxic arsenic trioxide to the environment. Arsenic (As) is also naturally elevated at these sites due its occurrence in Yellowknife Supergroup greenstone belts and surficial geologic deposits. To attempt to distinguish between geogenic and anthropogenic sources of As and characterize the role of climate change on metalloid mobility we used a freeze coring technology to capture lake sediments from the properties. Sediments were analyzed for sedimentary grain size and bulk geochemistry using ICP-MS to reconstruct climate and chemical change. Micropaleontological analyses are on-going. Interpretations of the physical, chemical, and biological archive

  3. Ranking Medical Terms to Support Expansion of Lay Language Resources for Patient Comprehension of Electronic Health Record Notes: Adapted Distant Supervision Approach.

    Science.gov (United States)

    Chen, Jinying; Jagannatha, Abhyuday N; Fodeh, Samah J; Yu, Hong

    2017-10-31

    Medical terms are a major obstacle for patients to comprehend their electronic health record (EHR) notes. Clinical natural language processing (NLP) systems that link EHR terms to lay terms or definitions allow patients to easily access helpful information when reading through their EHR notes, and have shown to improve patient EHR comprehension. However, high-quality lay language resources for EHR terms are very limited in the public domain. Because expanding and curating such a resource is a costly process, it is beneficial and even necessary to identify terms important for patient EHR comprehension first. We aimed to develop an NLP system, called adapted distant supervision (ADS), to rank candidate terms mined from EHR corpora. We will give EHR terms ranked as high by ADS a higher priority for lay language annotation-that is, creating lay definitions for these terms. Adapted distant supervision uses distant supervision from consumer health vocabulary and transfer learning to adapt itself to solve the problem of ranking EHR terms in the target domain. We investigated 2 state-of-the-art transfer learning algorithms (ie, feature space augmentation and supervised distant supervision) and designed 5 types of learning features, including distributed word representations learned from large EHR data for ADS. For evaluating ADS, we asked domain experts to annotate 6038 candidate terms as important or nonimportant for EHR comprehension. We then randomly divided these data into the target-domain training data (1000 examples) and the evaluation data (5038 examples). We compared ADS with 2 strong baselines, including standard supervised learning, on the evaluation data. The ADS system using feature space augmentation achieved the best average precision, 0.850, on the evaluation set when using 1000 target-domain training examples. The ADS system using supervised distant supervision achieved the best average precision, 0.819, on the evaluation set when using only 100 target

  4. Feasibility analysis of a smart grid photovoltaics system for the subarctic rural region in Alaska

    Science.gov (United States)

    Yao, Lei

    A smart grid photovoltaics system was developed to demonstrate that the system is feasible for a similar off-grid rural community in the subarctic region in Alaska. A system generation algorithm and a system business model were developed to determine feasibility. Based on forecasts by the PV F-Chart software, a 70° tilt angle in winter, and a 34° tilt angle in summer were determined to be the best angles for electrical output. The proposed system's electricity unit cost was calculated at 32.3 cents/kWh that is cheaper than current unsubsidized electricity price (46.8 cents/kWh) in off-grid rural communities. Given 46.8 cents/kWh as the electricity unit price, the system provider can break even when 17.3 percent of the total electrical revenue through power generated by the proposed system is charged. Given these results, the system can be economically feasible during the life-cycle period. With further incentives, the system may have a competitive advantage.

  5. Ecosystem change and stability over multiple decades in the Swedish subarctic: complex processes and multiple drivers.

    Science.gov (United States)

    Callaghan, Terry V; Jonasson, Christer; Thierfelder, Tomas; Yang, Zhenlin; Hedenås, Henrik; Johansson, Margareta; Molau, Ulf; Van Bogaert, Rik; Michelsen, Anders; Olofsson, Johan; Gwynn-Jones, Dylan; Bokhorst, Stef; Phoenix, Gareth; Bjerke, Jarle W; Tømmervik, Hans; Christensen, Torben R; Hanna, Edward; Koller, Eva K; Sloan, Victoria L

    2013-08-19

    The subarctic environment of northernmost Sweden has changed over the past century, particularly elements of climate and cryosphere. This paper presents a unique geo-referenced record of environmental and ecosystem observations from the area since 1913. Abiotic changes have been substantial. Vegetation changes include not only increases in growth and range extension but also counterintuitive decreases, and stability: all three possible responses. Changes in species composition within the major plant communities have ranged between almost no changes to almost a 50 per cent increase in the number of species. Changes in plant species abundance also vary with particularly large increases in trees and shrubs (up to 600%). There has been an increase in abundance of aspen and large changes in other plant communities responding to wetland area increases resulting from permafrost thaw. Populations of herbivores have responded to varying management practices and climate regimes, particularly changing snow conditions. While it is difficult to generalize and scale-up the site-specific changes in ecosystems, this very site-specificity, combined with projections of change, is of immediate relevance to local stakeholders who need to adapt to new opportunities and to respond to challenges. Furthermore, the relatively small area and its unique datasets are a microcosm of the complexity of Arctic landscapes in transition that remains to be documented.

  6. Food web topology and parasites in the pelagic zone of a subarctic lake

    Science.gov (United States)

    Amundsen, Per-Arne; Lafferty, K.D.; Knudsen, R.; Primicerio, R.; Klemetsen, A.; Kuris, A.M.

    2009-01-01

    Parasites permeate trophic webs with their often complex life cycles, but few studies have included parasitism in food web analyses. Here we provide a highly resolved food web from the pelagic zone of a subarctic lake and explore how the incorporation of parasites alters the topology of the web. 2. Parasites used hosts at all trophic levels and increased both food-chain lengths and the total number of trophic levels. Their inclusion in the network analyses more than doubled the number of links and resulted in an increase in important food-web characteristics such as linkage density and connectance. 3. More than half of the parasite taxa were trophically transmitted, exploiting hosts at multiple trophic levels and thus increasing the degree of omnivory in the trophic web. 4. For trophically transmitted parasites, the number of parasite-host links exhibited a positive correlation with the linkage density of the host species, whereas no such relationship was seen for nontrophically transmitted parasites. Our findings suggest that the linkage density of free-living species affects their exposure to trophically transmitted parasites, which may be more likely to adopt highly connected species as hosts during the evolution of complex life cycles. 5. The study supports a prominent role for parasites in ecological networks and demonstrates that their incorporation may substantially alter considerations of food-web structure and functioning. ?? 2009 British Ecological Society.

  7. Impact of early and late winter icing events on sub-arctic dwarf shrubs.

    Science.gov (United States)

    Preece, C; Phoenix, G K

    2014-01-01

    Polar regions are predicted to undergo large increases in winter temperature and an increased frequency of freeze-thaw cycles, which can cause ice layers in the snow pack and ice encasement of vegetation. Early or late winter timing of ice encasement could, however, modify the extent of damage caused to plants. To determine impacts of the date of ice encasement, a novel field experiment was established in sub-arctic Sweden, with icing events simulated in January and March 2008 and 2009. In the subsequent summers, reproduction, phenology, growth and mortality, as well as physiological indicators of leaf damage were measured in the three dominant dwarf shrubs: Vaccinium uliginosum, Vaccinium vitis-idaea and Empetrum nigrum. It was hypothesised that January icing would be more damaging compared to March icing due to the longer duration of ice encasement. Following 2 years of icing, E. nigrum berry production was 83% lower in January-iced plots compared to controls, and V. vitis-idaea electrolyte leakage was increased by 69%. Conversely, electrolyte leakage of E. nigrum was 25% lower and leaf emergence of V. vitis-idaea commenced 11 days earlier in March-iced plots compared to control plots in 2009. There was no effect of icing on any of the other parameters measured, indicating that overall these study species have moderate to high tolerance to ice encasement. Even much longer exposure under the January icing treatment does not clearly increase damage. © 2013 German Botanical Society and The Royal Botanical Society of the Netherlands.

  8. Paleoclimatic significance of chemical weathering in loess-derived paleosols of subarctic central Alaska

    Science.gov (United States)

    Muhs, D.R.; Ager, T.A.; Skipp, G.; Beann, J.; Budahn, J.; McGeehin, J.P.

    2008-01-01

    Chemical weathering in soils has not been studied extensively in high-latitude regions. Loess sequences with modern soils and paleosols are present in much of subarctic Alaska, and allow an assessment of present and past chemical weathering. Five sections were studied in detail in the Fairbanks, Alaska, area. Paleosols likely date to mid-Pleistocene interglacials, the last interglacial, and early-to-mid-Wisconsin interstadiale. Ratios of mobile (Na, Ca, Mg, Si) to immobile (Ti or Zr) elements indicate that modern soils and most interstadial and interglacial paleosols are characterized by significant chemical weathering. Na2O/TiO2 is lower in modern soils and most paleosols compared to parent loess, indicating depletion of plagioclase. In the clay fraction, smectite is present in Tanana and Yukon River source sediments, but is absent or poorly expressed in modern soils and paleosols, indicating depletion of this mineral also. Loss of both plagioclase and smectite is well expressed in soils and paleosols as lower SiO 2/TiO2. Carbonates are present in the river source sediments, but based on CaO/TiO2, they are depleted in soils and most paleosols (with one exception in the early-to-mid-Wisconsin period). Thus, most soil-forming intervals during past interglacial and interstadial periods in Alaska had climatic regimes that were at least as favorable to mineral weathering as today, and suggest boreal forest or acidic tundra vegetation. ?? 2008 Regents of the University of Colorado.

  9. Impacts of Deforestation and Climate Variability on Terrestrial Evapotranspiration in Subarctic China

    Directory of Open Access Journals (Sweden)

    Yunjun Yao

    2014-10-01

    Full Text Available Although deforestation affects hydrological and climatic variables over tropical regions, its actual contributions to changes in evapotranspiration (ET over subarctic China remain unknown. To establish a quantitative relationship between deforestation and terrestrial ET variations, we estimated ET using a semi-empirical Penman (SEMI-PM algorithm driven by meteorological and satellite data at both local and regional scales. The results indicate that the estimated ET can be used to analyse the observed inter-annual variations. There is a statistically significant positive relationship between local-scale forest cover changes (∆F and annual ET variations (∆ET of the following form: ∆ET = 0.0377∆F – 2.11 (R2 = 0.43, p < 0.05. This relationship may be due to deforestation-induced increases in surface albedo and a reduction in the fractional vegetation cover (FVC. However, the El Niño/Southern Oscillation (ENSO, rather than deforestation, dominates the multi-decadal ET variability due to regional-scale wind speed changes, but the exact effects of deforestation and ENSO on ET are challenging to quantify.

  10. The relative contributions of biological and abiotic processes to carbon dynamics in subarctic sea ice

    DEFF Research Database (Denmark)

    Søgaard, Dorte Haubjerg; Thomas, David N.; Rysgaard, Søren

    2013-01-01

    Knowledge on the relative effects of biological activity and precipitation/dissolution of calcium carbonate (CaCO3) in influencing the air-ice CO2 exchange in sea-ice-covered season is currently lacking. Furthermore, the spatial and temporal occurrence of CaCO3 and other biogeochemical parameters...... in sea ice are still not well described. Here we investigated autotrophic and heterotrophic activity as well as the precipitation/dissolution of CaCO3 in subarctic sea ice in South West Greenland. Integrated over the entire ice season (71 days), the sea ice was net autotrophic with a net carbon fixation...... of 56 mg C m(-2), derived from a sea-ice-related gross primary production of 153 mg C m(-2) and a bacterial carbon demand of 97 mg C m(-2). Primary production contributed only marginally to the TCO2 depletion of the sea ice (7-25 %), which was mainly controlled by physical export by brine drainage...

  11. The Recovery of Two Polluted Subarctic Lakes—Towards Nutrient Management or a Pristine State?

    Directory of Open Access Journals (Sweden)

    Erik Grönlund

    2012-10-01

    Full Text Available Two small subarctic lakes were eutrophicated due to wastewater discharge from 1964. In 1975, a wastewater treatment plant was built and a recovery process started. This paper will: (1 compile the 1972–1974, 1978–1980 and 1985–1988 investigation data regarding phosphorous and microalgae for one of the lakes; (2 complement with unpublished data from 1985 and 2003; and (3 introduce a discussion regarding three alternatives for future development of the lakes in their last phase of recovery. In the latest investigation, 2003, the lakes were assessed as almost recovered. They had returned to an oligotrophic state, but not fully to a pre-sewage situation. In the upper lake, more heavily polluted, the total phosphorous levels had decreased from an average of 168 µg P/L in 1972–1974 to an average of 12 µg P/L in 2003. The phytoplankton biomass had decreased twentyfold during the same period, from 11.2 mg/L to 0.6 mg/L. The Secchi depth had increased from 1.3 m to 2.8 m. The low oxygen level in late winter was still not recovered, thereby profoundly affecting residential organisms in the lakes. The low winter oxygen is assumed to remain so for a long time due to phosphorus release from sediments in the lakes.

  12. Potential of C and X Band SAR for Shrub Growth Monitoring in Sub-Arctic Environments

    Directory of Open Access Journals (Sweden)

    Yannick Duguay

    2015-07-01

    Full Text Available The Arctic and sub-Arctic environments have seen a rapid growth of shrub vegetation at the expense of the Arctic tundra in recent decades. In order to develop better tools to assess and understand this phenomenon, the sensitivity of multi-polarized SAR backscattering at C and X band to shrub density and height is studied under various conditions. RADARSAT-2 and TerraSAR-X images were acquired from November 2011 to March 2012 over the Umiujaq community in northern Quebec (56.55°N, 76.55°W and compared to in situ measurements of shrub vegetation density and height collected during the summer of 2009. The results show that σ0 is sensitive to changes in shrub coverage up to 20% and is sensitive to changes in shrub height up to around 1 m. The cross-polarized backscattering (σ0 HV displays the best sensitivity to both shrub height and density, and RADARSAT-2 is more sensitive to shrub height, as TerraSAR-X tends to saturate more rapidly with increasing volume scattering from the shrub branches. These results demonstrate that SAR data could provide essential information, not only on Remote Sens. 2015, 7 9411 the spatial expansion of shrub vegetation, but also on its vertical growth, especially at early stages of colonization.

  13. Multi-trophic level response to extreme metal contamination from gold mining in a subarctic lake.

    Science.gov (United States)

    Thienpont, Joshua R; Korosi, Jennifer B; Hargan, Kathryn E; Williams, Trisha; Eickmeyer, David C; Kimpe, Linda E; Palmer, Michael J; Smol, John P; Blais, Jules M

    2016-08-17

    Giant Mine, located in the city of Yellowknife (Northwest Territories, Canada), is a dramatic example of subarctic legacy contamination from mining activities, with remediation costs projected to exceed $1 billion. Operational between 1948 and 2004, gold extraction at Giant Mine released large quantities of arsenic and metals from the roasting of arsenopyrite ore. We examined the long-term ecological effects of roaster emissions on Pocket Lake, a small lake at the edge of the Giant Mine lease boundary, using a spectrum of palaeoenvironmental approaches. A dated sedimentary profile tracked striking increases (approx. 1700%) in arsenic concentrations coeval with the initiation of Giant Mine operations. Large increases in mercury, antimony and lead also occurred. Synchronous changes in biological indicator assemblages from multiple aquatic trophic levels, in both benthic and pelagic habitats, indicate dramatic ecological responses to extreme metal(loid) contamination. At the peak of contamination, all Cladocera, a keystone group of primary consumers, as well as all planktonic diatoms, were functionally lost from the sediment record. No biological recovery has been inferred, despite the fact that the bulk of metal(loid) emissions occurred more than 50 years ago, and the cessation of all ore-roasting activities in Yellowknife in 1999. © 2016 The Author(s).

  14. High variation subarctic topsoil pollutant concentration prediction using neural network residual kriging

    Science.gov (United States)

    Sergeev, A. P.; Tarasov, D. A.; Buevich, A. G.; Subbotina, I. E.; Shichkin, A. V.; Sergeeva, M. V.; Lvova, O. A.

    2017-06-01

    The work deals with the application of neural networks residual kriging (NNRK) to the spatial prediction of the abnormally distributed soil pollutant (Cr). It is known that combination of geostatistical interpolation approaches (kriging) and neural networks leads to significantly better prediction accuracy and productivity. Generalized regression neural networks and multilayer perceptrons are classes of neural networks widely used for the continuous function mapping. Each network has its own pros and cons; however both demonstrated fast training and good mapping possibilities. In the work, we examined and compared two combined techniques: generalized regression neural network residual kriging (GRNNRK) and multilayer perceptron residual kriging (MLPRK). The case study is based on the real data sets on surface contamination by chromium at a particular location of the subarctic Novy Urengoy, Russia, obtained during the previously conducted screening. The proposed models have been built, implemented and validated using ArcGIS and MATLAB environments. The networks structures have been chosen during a computer simulation based on the minimization of the RMSE. MLRPK showed the best predictive accuracy comparing to the geostatistical approach (kriging) and even to GRNNRK.

  15. Spatial distribution of aquatic marine fungi across the western Arctic and sub-arctic.

    Science.gov (United States)

    Hassett, Brandon T; Ducluzeau, Anne-Lise L; Collins, Roy E; Gradinger, Rolf

    2017-02-01

    Fungi are important parasites of primary producers and nutrient cyclers in aquatic ecosystems. In the Pacific-Arctic domain, fungal parasitism is linked to light intensities and algal stress that can elevate disease incidence on algae and reduce diatom concentrations. Fungi are vastly understudied in the marine realm and knowledge of their function is constrained by the current understanding of fungal distribution and drivers on global scales. To investigate the spatial distribution of fungi in the western Arctic and sub-Arctic, we used high throughput methods to sequence 18S rRNA, cloned and sequenced 28S rRNA and microscopically counted chytrid-infected diatoms. We identified a broad distribution of fungal taxa predominated by Chytridiomycota and Dikarya. Phylogenetic analysis of our Chytridiomycota clones placed Arctic marine fungi sister to the order Lobulomycetales. This clade of fungi predominated in fungal communities under ice with low snowpack. Microscopic examination of fixed seawater and sea ice samples revealed chytrids parasitizing diatoms collected across the Arctic that notably infected 25% of a single diatom species in the Bering Sea. The Pezizomycotina comprised > 95% of eukaryotic sequence reads in Greenland, providing preliminary evidence for osmotrophs being a substitute for algae as the base of food webs. © 2016 Society for Applied Microbiology and John Wiley & Sons Ltd.

  16. UAV Remote Sensing Surveillance of a Mine Tailings Impoundment in Sub-Arctic Conditions

    Directory of Open Access Journals (Sweden)

    Anssi Rauhala

    2017-12-01

    Full Text Available Mining typically involves extensive areas where environmental monitoring is spatially sporadic. New remote sensing techniques and platforms such as Structure from Motion (SfM and unmanned aerial vehicles (UAVs may offer one solution for more comprehensive and spatially continuous measurements. We conducted UAV campaigns in three consecutive summers (2015–2017 at a sub-Arctic mining site where production was temporarily suspended. The aim was to monitor a 0.5 km2 tailings impoundment and measure potential subsidence of tailings. SfM photogrammetry was used to produce yearly topographical models of the tailings surface, which allowed the amount of surface displacement between years to be tracked. Ground checkpoints surveyed in stable areas of the impoundment were utilized in assessing the vertical accuracy of the models. Observed surface displacements were linked to a combination of erosion, tailings settlement, and possible compaction of the peat layer underlying the tailings. The accuracy obtained indicated that UAV-assisted monitoring of tailings impoundments is sufficiently accurate for supporting impoundment management operations and for tracking surface displacements in the decimeter range.

  17. The Biogeochemical Response to Inter-decadal Atmospheric Forcing Across Watershed Scales in Canada's Subarctic

    Science.gov (United States)

    Spence, C.

    2016-12-01

    Rapid landscape changes in the circumpolar north have been documented, including degradation of permafrost and alteration of vegetation communities. These are widely expected to have profound impacts on the freshwater fluxes of solutes, carbon and nitrogen across the Arctic domain. However, there have been few attempts to document trends across the diversity of landscapes in the circumpolar north, mostly due to a dearth of long term data. Some of the fastest rates of warming over the last thirty years have occurred in Canada's Northwest Territories, so this region should already exhibit changes in aquatic chemistry. Observations of chemical loads in streams draining the ice-poor discontinuous permafrost subarctic Canadian Shield region were analyzed with the goal of determining how basins across scales have responded to changes in atmospheric forcing. Smaller streams, with much closer linkages to terrestrial processes, experienced a synchrony among hydrological and biogeochemical processes that enhanced chemical flux above that in their larger counterparts. This demonstrates that there are differences in resiliency and resistance across scales to climate change. These results highlight the importance of biogeochemical process understanding to properly explain and predict how chemical loading scales from headwaters to river mouths. This is important information if society is to properly adapt policies for effluent discharge, nearshore marine management, among others.

  18. Political Unrest and Educational Electronic Resource Usage in a Conflict Zone, Kashmir (Indian Administered Kashmir): Log Analysis as Politico Analytical Tool=Hindistan Tarafından Yönetilen Keşmir Anlaşmazlık Bölgesi’nde Siyasi Karışıklık ve Eğitimle İlgili Elektronik Kaynakların Kullanımı: Siyasi Analiz Aracı Olarak Log Analizleri

    OpenAIRE

    Sumeer Gul; Samrin Nabi; Samina Mushtaq; Tariq Ahmad Shah; Suhail Ahmad

    2013-01-01

    Electronic resource usage has proved as one of the best decision making tools in the library setups. Electronic resource usage in relation to the political disturbance can act as one of the tools to highlight the impact of political disturbance on educational setups in general and the electronic resource usage in particular. The study takes a serious look in the electronic resource usage in Kashmir and the impact of unrest on it. The paper highlights a relational platform between educat...

  19. Establishing the Role of Digital Repeat Photography in Understanding Phenology and Carbon Cycling in a Subarctic Peatland

    Science.gov (United States)

    Garnello, Anthony John

    In this thesis, I establish and explore the role of phenology in understanding the rapidly changing environment of a subarctic peatland. First, I demonstrate how digital repeat photography can be used to characterize and differentiate distinct plant communities using two years of images. Each habitat is composed of different plant functional groups, promoting the individualistic approach to characterization that near-earth remote sensing tools can provide. The camera-product Relative Greenness successfully characterized interannual variability in seasonal growth for each habitat type. Across habitats, there was a direct relationship between advancement of spring onset and active season growth though this overall pattern showed habitat-specific variance. The camera images were also useful in characterizing the flowering phenology of an eriophorum-rich fen habitat, for which a metric named Intensity was created. These results suggest that employment of phenology cameras in highly heterogeneous subarctic environments is a robust method to characterize phenology on a habitat to species scale. Next, I explored the role that this phenology product has in modeling Net Ecosystem Exchange (NEE) also measured at the field site. I hypothesized that the explanatory power of the phenology index, which is conceptually tied to a measure of photosynthetic capacity, would be tightly linked to the timescale it was used for: At sub-daily timescales, environmental forces would dominate, though when averaged over days to weekly scales, the biology represented through the camera index would be more influential. I show that at multiple time scales the environmental factors outperform the camera index when modeling NEE. Together, these studies begin to explore the applicability of phenology camera systems in subarctic environments.

  20. Subarctic wintertime dissolved iron speciation driven by thermal constraints on Fe(II) oxidation, dissolved organic matter and stream reach

    Science.gov (United States)

    Morita, Yuichiroh; Yamagata, Kei; Oota, Atsuki; Ooki, Atsushi; Isoda, Yutaka; Kuma, Kenshi

    2017-10-01

    We studied the seasonal variations in Fe(II), Fe(III), humic-like dissolved organic matter (DOM), nitrate and nitrite (NO3 + NO2), and silicate (Si(OH)4) in river waters of three subarctic rivers flowing into Hakodate Bay in southwestern Hokkaido, Japan from May 2010 to February 2014. High Fe(II) concentrations were detected in winter at the sampling sites where the river bottom was comprised of sandy or silty sediment, primarily the lower and middle reaches of the rivers. Conversely, from early spring to late autumn Fe(II) levels were low or undetectable. We infer that soluble Fe(II) concentration in these subarctic river waters is driven by the balance between the influx of Fe(II) to the river and the Fe(II) oxidation rates that determines the dynamics in Fe(II) concentration in the river water. The Fe(II) may originate from reductive dissolution of Fe(III) in the river sediment or from Fe(II)-bearing groundwater. The latter seems to be the most likely source during winter time. The high Fe(II) concentrations during winter is predominantly attributed to the extremely slow oxidation rate of Fe(II) to Fe(III) at low water temperature rather than to an actual increase in the flux of reduced Fe(II). Nevertheless, we propose that the flux of reduced Fe(II) from river sediments and groundwater in lowland area of the catchment to overlying river waters might be the most important sources of iron in river waters. This provides an important insight into the role of river processes and the interaction between climate and river morphology in determining the inputs of iron to subarctic coastal marine waters.

  1. Earthworm impacts on organo-mineral interactions and soil carbon inventories in Fennoscandian boreal and sub-arctic landscapes

    Science.gov (United States)

    Wackett, Adrian; Yoo, Kyungsoo; Cameron, Erin; Klaminder, Jonatan

    2017-04-01

    Boreal and sub-arctic environments sustain some of the most pristine and fragile ecosystems in the world and house a disproportionate amount of the global soil carbon pool. Although the historical view of soil carbon turnover has focused on the intrinsic molecular structure of organic matter, recent work has highlighted the importance of stabilizing soil carbon on reactive mineral surfaces. However, the rates and mechanisms controlling these processes at high latitudes are poorly understood. Here we explored the biogeochemical impacts of deep-burrowing earthworm species on a range of Fennoscandian forest soils to investigate how earthworms impact soil carbon inventories and organo-mineral associations across boreal and sub-arctic landscapes. We sampled soils and earthworms at six sites spanning almost ten degrees latitude and encompassing a wide range of soil types and textures, permitting simultaneous consideration of how climate and mineralogy affect earthworm-mediated shifts in soil carbon dynamics. Across all sites, earthworms significantly decreased the carbon and nitrogen contents of the upper 10 cm, presumably through consumption of the humus layer and subsequent incorporation of the underlying mineral soil into upper organic horizons. Their mixing of humus and underlying soil also generally increased the proportion of mineral surface area occluded by organic matter, although the extent to which earthworms facilitate such organo-mineral interactions appears to be controlled by soil texture and mineralogy. This work indicates that quantitative measurements of mineral surface area and its extent of coverage by soil organic matter facilitate scaling up of molecular interactions between organic matter and minerals to the level of soil profiles and landscapes. Our preliminary data also strongly suggests that earthworms have profound effects on the fate of soil carbon and nitrogen in boreal and sub-arctic environments, highlighting the need for a better

  2. Measuring the relative resilience of subarctic lakes to global change: redundancies of functions within and across temporal scales

    Science.gov (United States)

    Angeler, David G.; Allen, Craig R.; Johnson, Richard K.

    2013-01-01

    1. Ecosystems at high altitudes and latitudes are expected to be particularly vulnerable to the effects of global change. We assessed the responses of littoral invertebrate communities to changing abiotic conditions in subarctic Swedish lakes with long-term data (1988–2010) and compared the responses of subarctic lakes with those of more southern, hemiboreal lakes. 2. We used a complex systems approach, based on multivariate time-series modelling, and identified dominant and distinct temporal frequencies in the data; that is, we tracked community change at distinct temporal scales. We determined the distribution of functional feeding groups of invertebrates within and across temporal scales. Within and cross-scale distributions of functions have been considered to confer resilience to ecosystems, despite changing environmental conditions. 3. Two patterns of temporal change within the invertebrate communities were identified that were consistent across the lakes. The first pattern was one of monotonic change associated with changing abiotic lake conditions. The second was one of showing fluctuation patterns largely unrelated to gradual environmental change. Thus, two dominant and distinct temporal frequencies (temporal scales) were present in all lakes analysed. 4. Although the contribution of individual feeding groups varied between subarctic and hemiboreal lakes, they shared overall similar functional attributes (richness, evenness, diversity) and redundancies of functions within and between the observed temporal scales. This highlights similar resilience characteristics in subarctic and hemiboreal lakes. 5. Synthesis and applications. The effects of global change can be particularly strong at a single scale in ecosystems. Over time, this can cause monotonic change in communities and eventually lead to a loss of important ecosystem services upon reaching a critical threshold. Dynamics at other spatial or temporal scales can be unrelated to environmental change

  3. Distributions and seasonal abundances of krill eggs and larvae in the sub-Arctic Godthåbsfjord, SW Greenland

    DEFF Research Database (Denmark)

    Teglhus, Frederik Wolff; Agersted, Mette Dalgaard; Akther, Hasna

    2015-01-01

    The larval krill community (Thysanoessa spp.) was investigated along the sub-Arctic Godthåbsfjord, SW Greenland, in June 2010. In addition, the progress of krill development from egg to furcilia was studied from March to August 2010 in a fjord branching off the Godthåbsfjord. Krill spawned from...... and furcilia stages lasted 22 and 63 d, respectively. The growth rate from metanauplius to calyptopis was 0.12 d−1, while the growth rate across all developmental stages was 0.05 d−1. Mortality rates were calculated as 25% from eggs to nauplii, 48% from eggs to calyptopes and 83% from eggs to furcilia. During...

  4. Year-round CH4 and CO2 flux dynamics in two contrasting freshwater ecosystems of the subarctic

    Directory of Open Access Journals (Sweden)

    M. Jammet

    2017-11-01

    Full Text Available Lakes and wetlands, common ecosystems of the high northern latitudes, exchange large amounts of the climate-forcing gases methane (CH4 and carbon dioxide (CO2 with the atmosphere. The magnitudes of these fluxes and the processes driving them are still uncertain, particularly for subarctic and Arctic lakes where direct measurements of CH4 and CO2 emissions are often of low temporal resolution and are rarely sustained throughout the entire year. Using the eddy covariance method, we measured surface–atmosphere exchange of CH4 and CO2 during 2.5 years in a thawed fen and a shallow lake of a subarctic peatland complex. Gas exchange at the fen exhibited the expected seasonality of a subarctic wetland with maximum CH4 emissions and CO2 uptake in summer, as well as low but continuous emissions of CH4 and CO2 throughout the snow-covered winter. The seasonality of lake fluxes differed, with maximum CO2 and CH4 flux rates recorded at spring thaw. During the ice-free seasons, we could identify surface CH4 emissions as mostly ebullition events with a seasonal trend in the magnitude of the release, while a net CO2 flux indicated photosynthetic activity. We found correlations between surface CH4 emissions and surface sediment temperature, as well as between diel CO2 uptake and diel solar input. During spring, the breakdown of thermal stratification following ice thaw triggered the degassing of both CH4 and CO2. This spring burst was observed in 2 consecutive years for both gases, with a large inter-annual variability in the magnitude of the CH4 degassing. On the annual scale, spring emissions converted the lake from a small CO2 sink to a CO2 source: 80 % of total annual carbon emissions from the lake were emitted as CO2. The annual total carbon exchange per unit area was highest at the fen, which was an annual sink of carbon with respect to the atmosphere. Continuous respiration during the winter partly counteracted the fen summer sink by accounting for

  5. Year-round CH4 and CO2 flux dynamics in two contrasting freshwater ecosystems of the subarctic

    Science.gov (United States)

    Jammet, Mathilde; Dengel, Sigrid; Kettner, Ernesto; Parmentier, Frans-Jan W.; Wik, Martin; Crill, Patrick; Friborg, Thomas

    2017-11-01

    Lakes and wetlands, common ecosystems of the high northern latitudes, exchange large amounts of the climate-forcing gases methane (CH4) and carbon dioxide (CO2) with the atmosphere. The magnitudes of these fluxes and the processes driving them are still uncertain, particularly for subarctic and Arctic lakes where direct measurements of CH4 and CO2 emissions are often of low temporal resolution and are rarely sustained throughout the entire year. Using the eddy covariance method, we measured surface-atmosphere exchange of CH4 and CO2 during 2.5 years in a thawed fen and a shallow lake of a subarctic peatland complex. Gas exchange at the fen exhibited the expected seasonality of a subarctic wetland with maximum CH4 emissions and CO2 uptake in summer, as well as low but continuous emissions of CH4 and CO2 throughout the snow-covered winter. The seasonality of lake fluxes differed, with maximum CO2 and CH4 flux rates recorded at spring thaw. During the ice-free seasons, we could identify surface CH4 emissions as mostly ebullition events with a seasonal trend in the magnitude of the release, while a net CO2 flux indicated photosynthetic activity. We found correlations between surface CH4 emissions and surface sediment temperature, as well as between diel CO2 uptake and diel solar input. During spring, the breakdown of thermal stratification following ice thaw triggered the degassing of both CH4 and CO2. This spring burst was observed in 2 consecutive years for both gases, with a large inter-annual variability in the magnitude of the CH4 degassing. On the annual scale, spring emissions converted the lake from a small CO2 sink to a CO2 source: 80 % of total annual carbon emissions from the lake were emitted as CO2. The annual total carbon exchange per unit area was highest at the fen, which was an annual sink of carbon with respect to the atmosphere. Continuous respiration during the winter partly counteracted the fen summer sink by accounting for, as both CH4 and CO2, 33

  6. Wetland development, permafrost history and nutrient cycling inferred from late Holocene peat and lake sediment records in subarctic Sweden

    DEFF Research Database (Denmark)

    Kokfelt, U.; Reuss, N.; Struyf, E.

    2010-01-01

    -induced changes in hydrology may further have affected the inflow of alkaline water from the catchment. Elevated contents of biogenic silica and diatom pigments in lake sediments during periods of poor fen and bog expansion further indicate that terrestrial vegetation influenced the amount of nutrients entering...... insight into nutrient and permafrost dynamics in a subarctic wetland and imply that continued permafrost decay and related vegetation changes towards minerotrophy may increase carbon and nutrient storage of mire deposits and reduce nutrient fluxes in runoff. Rapid permafrost degradation may on the other...

  7. Ozone variability and halogen oxidation within the Arctic and sub-Arctic springtime boundary layer

    Directory of Open Access Journals (Sweden)

    J. B. Gilman

    2010-11-01

    Full Text Available The influence of halogen oxidation on the variabilities of ozone (O3 and volatile organic compounds (VOCs within the Arctic and sub-Arctic atmospheric boundary layer was investigated using field measurements from multiple campaigns conducted in March and April 2008 as part of the POLARCAT project. For the ship-based measurements, a high degree of correlation (r = 0.98 for 544 data points collected north of 68° N was observed between the acetylene to benzene ratio, used as a marker for chlorine and bromine oxidation, and O3 signifying the vast influence of halogen oxidation throughout the ice-free regions of the North Atlantic. Concurrent airborne and ground-based measurements in the Alaskan Arctic substantiated this correlation and were used to demonstrate that halogen oxidation influenced O3 variability throughout the Arctic boundary layer during these springtime studies. Measurements aboard the R/V Knorr in the North Atlantic and Arctic Oceans provided a unique view of the transport of O3-poor air masses from the Arctic Basin to latitudes as far south as 52° N. FLEXPART, a Lagrangian transport model, was used to quantitatively determine the exposure of air masses encountered by the ship to first-year ice (FYI, multi-year ice (MYI, and total ICE (FYI+MYI. O3 anti-correlated with the modeled total ICE tracer (r = −0.86 indicating that up to 73% of the O3 variability measured in the Arctic marine boundary layer could be related to sea ice exposure.

  8. Diurnal Variations of CH4 and CO2 Exchange in a Sub-Arctic Peatland Ecosystem

    Science.gov (United States)

    Berg, A.; Oquist, M. G.; Svensson, B. H.

    2003-04-01

    We investigated the diurnal variations of CH_4 and CO_2 fluxes from a sub-arctic peatland ecosystem in order to evaluate short-term controls on exchange dynamics and the importance of vascular plant photosynthetic activity. The study site was a semi-dry ombrotrophic habitat with a vascular plant community dominated by Eriophorum vaginatum L. and Carex rotundata Whalenb. Measurements were carried out at six sub-sites, three controls and three that were shaded with sack cloth in order to reduce the magnitude and extent of photosynthetic activity. Gas exchange rates, soil temperatures and porewater concentrations of methane and acetate were measured at 2--4 h intervals during a cloud-free diurnal cycle. During the day the variations in methane flux had the same temporal pattern as the gross photosynthetic rate and in combination with porewater acetate concentrations it could explain ca 60% of the variation. Average CH_4 emission rates tended to be higher during the night and correlated best with porewater CH_4 concentrations (r^2 > 0.9). When photosynthesis seized in the evening it was associated with an increase of acetate concentrations in the rhizosphere. This was followed by increases in porewater CH_4 concentrations and concomitant higher CH_4 flux rates with a lag of ca 2--4 h. The same pattern could be observed at both control and shaded sub-sites, but occurred earlier in the shaded, probably owing to an earlier decrease in light intensities. Apart from these substrate-based interactions we also found evidence confirming the importance of vascular plants in mediating CH_4 transport, and results suggest that this was linked to stomatal conductance. Our observations further stress the importance of vascular plant influence on CH_4 exchange dynamics from northern peatlands, and also add a new dimension to the complexities involved in these interactions.

  9. Future stratospheric ozone depletion will affect a subarctic dwarf shrub ecosystem

    Energy Technology Data Exchange (ETDEWEB)

    Johanson, Ulf

    1997-02-01

    The stratospheric ozone depletion and the concomitant increase in ultraviolet-B (UV-B, 280-320 nm) radiation is of global concern due to the effects of UV-B on living organisms. To investigate the effects of increased levels of UV-B, a field irradiation system was established at a subarctic dwarf shrub heath in Northern Sweden (68 deg N). An ozone depletion of 15% under clear sky conditions was simulated over a naturally growing ecosystem. The response of both individual components and processes was studied to reveal changes in ecosystem structure and function. Species with different life strategies (evergreen or deciduous) responded differently both in magnitude and direction. The evergreen species were more responsive to UV-B regarding shoot growth, which could be due to cumulative effects in long-lived tissues, since the retardation in relative growth increased over time of exposure. Leaves of evergreen species became thicker under enhanced UV-B, while leaves of deciduous species became thinner. Decomposition studies (laboratory and in situ) showed that indirect effects of UV-B, due to changes in leaf tissue chemistry affected microbial activity and slowed down the decomposition rate. More directly, UV-B decreased the abundance of some fungal species and hence the composition of species. However, no altered decomposition rate was found when decomposition progressed under high UV-B even if the microorganisms were fewer. This could be due to the increased direct photo degradation of litter that compensates for lower microbial activity. The decomposition rate is therefore strongly dependent on the interception of UV-B at the litter layer. This research has shown that ecosystem components and processes are affected in a number of ways and that there are indications of changes in species composition in a long-term perspective due to differences in responsiveness between the different species. 128 refs, 7 figs

  10. pH gradients in the diffusive boundary layer of subarctic macrophytes

    KAUST Repository

    Hendriks, Iris E.

    2017-06-20

    Highly productive macrophytes produce diurnal and seasonal cycles in CO concentrations modulated by metabolic activity, which cause discrepancies between pH in the bulk water and near seaweed blades, especially when entering the diffusion boundary layer (DBL). Calcifying epiphytic organisms living in this environment are therefore exposed to a different pH environment than that of the water column. To evaluate the actual pH environment on blade surfaces, we measured the thickness of the DBL and pH gradients within it for six subarctic macrophytes: Fucus vesiculosus, Ascophyllum nodosum, Ulva lactuca, Zostera marina, Saccharina longicruris, and Agarum clathratum. We measured pH under laboratory conditions at ambient temperatures (2–3 °C) and slow, stable flow over the blade surface at five light intensities (dark, 30, 50, 100 and 200 µmol photons m s). Boundary layer thickness ranged between 511 and 1632 µm, while the maximum difference in pH (∆pH) between the blade surface and the water column ranged between 0.4 ± 0.14 (average ± SE; Zostera) and 1.2 ± 0.13 (average ± SE; Ulva) pH units. These differences in pH are larger than predictions for pH changes in the bulk water by the end of the century. A simple quadratic model best described the relationship between light intensity and maximum ∆pH, pointing at relatively low optimum PAR of between 28 and 139 µmol photons m s to reach maximum ∆pH. Elevated pH at the blade surface may provide chemical “refugia” for calcifying epiphytic organisms, especially during summer at higher latitudes where photoperiods are long.

  11. Nitrogen isotope variations in the subarctic northeast Pacific: relationships to nitrate utilization and trophic structure

    Science.gov (United States)

    Wu, Jinping; Calvert, S. E.; Wong, C. S.

    1997-02-01

    The isotopic composition of dissolved nitrate, size-fractionated suspended particulate organic matter (SPOM) and zooplankton was determined on a transect (Line P) between a coastal upwwelling domain and Station Papa in the subarctic northeast Pacific. Station Papa lies in one of the three extensive high-nutrient low-chlorophyll (HNLC) domains of the open ocean, where plankton standing stocks are seasonally uniform and production is lower than the potential production based on available nutrients. In spring 1993, surface water δ15NO 3- decreased from east to west along the transect, from ca 12%. in the coastal domain to 8%. at Station Papa, while nitrate concentration ([N0 3-) increased from 3 to 12 μM in the same direction. Concurrently, δ15NO 3- at 400 m depth showed a much smaller change, from 5.3 to 3.1%., indicating a larger δ15N difference between deep and surface waters at the coastal end of the transect. The isotopic trend for SPOM was similar, from approximately 11 to 3%. for bulk SPOM, 8.5 to 3%. for the ocean where [NO 3-] > 7 μM, it increases rapidly where nitrate utilization is high (that is, where biological uptake is greater than physical supply), and it decreases during upwelling events when physical supply of nutrients overwhelms the biological uptake rate. Finally, the nitrogen isotopes show the expected trophic enrichment 15N, with bulk zooplankton being isotopically heavier than SPOM by 3.9%. at Station Papa and 2.2%. in the coastal domain. This difference possibly reflects the existence of a relatively short food chain in the coastal domain and a longer food chain, involving microzooplanktonic grazers, at Station Papa. The range of δ15N among seven zooplankton groups was 3.7%., the data suggesting an increasing trophic hierarchy: pteropods, salps, euphausiids, copepods-medusaeamphipods, chaetognaths.

  12. The emission of carbon dioxide from soils of the Pasvik nature reserve in the Kola Subarctic

    Science.gov (United States)

    Kadulin, M. S.; Smirnova, I. E.; Koptsyk, G. N.

    2017-09-01

    The emission of carbon dioxide (CO2) from podzols (Albic Podzols (Arenic)) and the factors controlling its spatiotemporal variability in the forest ecosystems of the Pasvik Reserve in the Kola Subarctic are characterized. Relatively favorable climatic conditions beyond the polar circle in summer are responsible for intensive soil respiration. The type of forest affects the emission of CO2 from the soil surface. The lowest rate of the CO2 emission is typical of the soils under lichen pine forest (105-220 mg C/(m2 h) or 180 g C/m2 during the summertime). Higher rates are observed for the soils under green moss pine (170-385 mg C/(m2 h) or 360 g C/m2 during the summertime) and birch (190-410 mg C/(m2 h) or 470 g C/m2 during the summertime) forests. This may related to a higher contribution of root respiration (44, 88, and 67%, respectively). Soil respiration and the contribution of root respiration to it increase with an increase in the canopy density; mass of small roots; microbial biomass; depth of the stony layer; soil moistening; and the contents of available carbon, nitrogen, phosphorus, and potassium compounds. At the same time, they decrease with an increase in the portion of lichens in the ground cover. The seasonal dynamics are characterized by the CO2 emission maximums in the summer and fall and minimum in the spring. The daily dynamics are smoothed under conditions of the polar day.

  13. Performance of an experimental wastewater treatment high-rate algal pond in subarctic climate.

    Science.gov (United States)

    Grönlund, Erik; Hanaeus, Jörgen; Johansson, Erica; Falk, Stefan

    2010-01-01

    A pilot-scale experimental high-rate algal pond (HRAP) was investigated in the subarctic mid-Sweden region, at latitude 63 degrees N. During autumn 2002, conditions included temperatures below 10 degrees C and photosynthetic active radiation below 200 microE/m2 x s. Biochemical oxygen demand was reduced by approximately 90% (approximately 40 g/m3), chemical oxygen demand by 65% (approximately 80 g/m3), total phosphorus by 20% (approximately 1 g/m3), and total nitrogen by 46% (approximately 15 g/m3), at a retention time of approximately 2.5 days. During autumn 2003, the performance of the HRAP appeared better with a more dense microalgae culture; however, as a result of poor settling of the microalgae, the reduction was considerably lower. A major difference between the years was the microalgae composition. In 2002, the large green algae Coelastrum dominated with Chlamydomonas, Scenedesmus, Lagerheimia, and the Cryptophyte Rhodomonas. In 2003, there was a total dominance of the very small green algae Chlorella, known to be difficult to settle. In batch growth experiments during spring 2002, doubling times of 4 to 6 days were achieved. The period of temperatures above 10 degrees C and an insolation of more than approximately 270 uE/m2 x s (125 Langleys), which is well-documented as appropriate for HRAP function (Oswald, 1988a, 1988c), were measured to last for 4 to 4.5 months from early May to late September. However, the growth and treatment performance experiments indicated that a longer season may be possible-6.5 to 7 months, at best-from early April to late October.

  14. Winter Insulation By Snow Accumulation in a Subarctic Treeline Ecosystem Increases Summer Carbon Cycling Rates

    Science.gov (United States)

    Parker, T.; Subke, J. A.; Wookey, P. A.

    2014-12-01

    The effect of snow accumulation on soil carbon and nutrient cycling is attracting substantial attention from researchers. We know that deeper snow accumulation caused by high stature vegetation increases winter microbial activity and therefore carbon and nitrogen flux rates. However, until now the effect of snow accumulation, by buffering winter soil temperature, on subsequent summer soil processes, has scarcely been considered. We carried out an experiment at an alpine treeline in subarctic Sweden in which soil monoliths, contained within PVC collars, were transplanted between forest (deep winter snow) and tundra heath (shallow winter snow). We measured soil CO2efflux over two growing seasons and quantified soil microbial biomass after the second winter. We showed that respiration rates of transplanted forest soil were significantly reduced compared with control collars (remaining in the forest) as a consequence of colder, but more variable, winter temperatures. We hypothesised that microbial biomass would be reduced in transplanted forests soils but found there was no difference compared to control. We therefore further hypothesised that the similarly sized microbial pool in the control is assembled differently to the transplant. We believe that the warmer winters in forests foster more active consortia of decomposer microbes as a result of different abiotic selection pressures. Using an ecosystem scale experimental approach, we have identified a mechanism that influences summer carbon cycling rates based solely on the amount of snow that accumulates the previous winter. We conclude that modification of snow depth as a consequence of changes in vegetation structure is an important mechanism influencing soil C stocks in ecosystems where snow persists for a major fraction of the year.

  15. Reconciling biodiversity conservation and agricultural expansion in the subarctic environment of Iceland

    Directory of Open Access Journals (Sweden)

    Lilja Jóhannesdóttir

    2017-03-01

    before further substantial changes in the extent of agriculture take place in this subarctic landscape.

  16. Cryoprotectants and extreme freeze tolerance in a subarctic population of the wood frog.

    Directory of Open Access Journals (Sweden)

    Jon P Costanzo

    Full Text Available Wood frogs (Rana sylvatica exhibit marked geographic variation in freeze tolerance, with subarctic populations tolerating experimental freezing to temperatures at least 10-13 degrees Celsius below the lethal limits for conspecifics from more temperate locales. We determined how seasonal responses enhance the cryoprotectant system in these northern frogs, and also investigated their physiological responses to somatic freezing at extreme temperatures. Alaskan frogs collected in late summer had plasma urea levels near 10 μmol ml-1, but this level rose during preparation for winter to 85.5 ± 2.9 μmol ml-1 (mean ± SEM in frogs that remained fully hydrated, and to 186.9 ± 12.4 μmol ml-1 in frogs held under a restricted moisture regime. An osmolality gap indicated that the plasma of winter-conditioned frogs contained an as yet unidentified osmolyte(s that contributed about 75 mOsmol kg-1 to total osmotic pressure. Experimental freezing to -8°C, either directly or following three cycles of freezing/thawing between -4 and 0°C, or -16°C increased the liver's synthesis of glucose and, to a lesser extent, urea. Concomitantly, organs shed up to one-half (skeletal muscle or two-thirds (liver of their water, with cryoprotectant in the remaining fluid reaching concentrations as high as 0.2 and 2.1 M, respectively. Freeze/thaw cycling, which was readily survived by winter-conditioned frogs, greatly increased hepatic glycogenolysis and delivery of glucose (but not urea to skeletal muscle. We conclude that cryoprotectant accrual in anticipation of and in response to freezing have been greatly enhanced and contribute to extreme freeze tolerance in northern R. sylvatica.

  17. Modeled and measured linkages between glaciers, permafrost and hydrology in a subarctic watershed, Interior Alaska

    Science.gov (United States)

    Gaedeke, A.; Liljedahl, A. K.; O'Neel, S.; Douglas, T. A.; Gatesman, T.; Daanen, R. P.; Zhang, J.; Campbell, S. W.

    2016-12-01

    Hydrological processes in subarctic, mountainous, glacierized watersheds are highly variable (seasonally and spatially) and are particularly vulnerable to climate change. Here, we combine field measurements and hydrological modeling to address the effects of altered glacier melt on lowland runoff, regional groundwater recharge/storage and permafrost distribution. Jarvis Creek watershed (630 km2), a headwater basin of the Tanana River (12,000 km2), in semi-arid Interior Alaska serves as our study area. The process-based, spatially distributed hydrological model WaSiM was utilized to simulate all aspects of the water cycle, including glacier melt, dynamic glacier coverage, seasonal soil freeze and thaw and permafrost. Downscaled regional climate scenarios force WaSiM for long-term climate change impact assessment. Field measurements (differential runoff, glacier mass balance, end-of-winter snow depths, soil temperature, and meteorology) are used to parameterize, calibrate and validate WaSiM. Our field measurements and modeling results indicate that Jarvis Creek, which is fed by on average 1/3 glacier runoff during summer, loses considerable amount of runoff to the regional aquifer. The aquifer, in turn, feeds the larger scale river system (Tanana River) throughout the year, which is especially prominent during winter when all overland runoff ceases and surface waters are covered with ice. Measured annual runoff increased from the nearby Gulkana Glacier during the last 50 years, which is consistent with an 11% decrease in glacier coverage (1950-2010) within the Tanana River basin. Glacier runoff is likely to continue to increase until glaciers recede to higher and cooler elevation. The changes in glacier runoff do not only affect the headwater streams (Jarvis Creek), but also the larger scale hydrological regime such as aquifer storage and release, long-term trends in winter baseflow of Tanana River and permafrost distribution.

  18. Physical and chemical characteristics of lakes across heterogeneous landscapes in arctic and subarctic Alaska

    Science.gov (United States)

    Larsen, A. S.; O'Donnell, J. A.; Schmidt, J. H.; Kristenson, H. J.; Swanson, D. K.

    2017-04-01

    Lakes are an important component of high-latitude regions, providing habitat for fish and wildlife and playing a critical role in biogeochemical and global carbon cycles. High-latitude lakes are sensitive to climate change, in part due to their development within permafrost soils. Considerable heterogeneity exists across arctic and subarctic landscapes, yet little is known about how this landscape variability influences chemical and physical attributes of lakes. We investigated the physical and chemical limnology of 617 lakes in Alaska's boreal forest and boreal-arctic transition zone. We categorized lakes into 10 basin types based on parent material, topography, genesis, and permafrost characteristics. Physical parameters varied across lake basin types, with the deepest lakes occurring in ice-poor glacial deposits and ice-rich terrain, while the shallowest lakes were observed in floodplain deposits and coastal lowlands. Dissolved inorganic nitrogen (N) and phosphorous (P) concentrations were generally low across all landscapes, whereas total N and P were highest in lakes underlain by ice-rich Pleistocene loess. Total N and P concentrations were significantly correlated with chlorophyll a, indicating a possible colimitation of primary productivity in these systems. Base cation concentrations helped elucidate lake basin hydrology and the relative influence of shallow versus deep groundwater inputs to surface water. Using these results, we developed a simple conceptual model for each lake and landscape type based on differences in physical and chemical parameters. Overall, we expect that the vulnerability of lake ecosystems to climate change will vary across lake basin types and will be mediated by spatial patterns in permafrost characteristics and subsurface hydrology.

  19. Bioavailable soil phosphorus decreases with increasing elevation in a subarctic tundra landscape.

    Directory of Open Access Journals (Sweden)

    Andrea G Vincent

    Full Text Available Phosphorus (P is an important macronutrient in arctic and subarctic tundra and its bioavailability is regulated by the mineralization of organic P. Temperature is likely to be an important control on P bioavailability, although effects may differ across contrasting plant communities with different soil properties. We used an elevational gradient in northern Sweden that included both heath and meadow vegetation types at all elevations to study the effects of temperature, soil P sorption capacity and oxalate-extractable aluminium (Alox and iron (Feox on the concentration of different soil P fractions. We hypothesized that the concentration of labile P fractions would decrease with increasing elevation (and thus declining temperature, but would be lower in meadow than in heath, given that N to P ratios in meadow foliage are higher. As expected, labile P in the form of Resin-P declined sharply with elevation for both vegetation types. Meadow soils did not have lower concentrations of Resin-P than heath soils, but they did have 2-fold and 1.5-fold higher concentrations of NaOH-extractable organic P and Residual P, respectively. Further, meadow soils had 3-fold higher concentrations of Alox + Feox and a 20% higher P sorption index than did heath soils. Additionally, Resin-P expressed as a proportion of total soil P for the meadow was on average half that in the heath. Declining Resin-P concentrations with elevation were best explained by an associated 2.5-3.0 °C decline in temperature. In contrast, the lower P availability in meadow relative to heath soils may be associated with impaired organic P mineralization, as indicated by a higher accumulation of organic P and P sorption capacity. Our results indicate that predicted temperature increases in the arctic over the next century may influence P availability and biogeochemistry, with consequences for key ecosystem processes limited by P, such as primary productivity.

  20. Bioavailable soil phosphorus decreases with increasing elevation in a subarctic tundra landscape.

    Science.gov (United States)

    Vincent, Andrea G; Sundqvist, Maja K; Wardle, David A; Giesler, Reiner

    2014-01-01

    Phosphorus (P) is an important macronutrient in arctic and subarctic tundra and its bioavailability is regulated by the mineralization of organic P. Temperature is likely to be an important control on P bioavailability, although effects may differ across contrasting plant communities with different soil properties. We used an elevational gradient in northern Sweden that included both heath and meadow vegetation types at all elevations to study the effects of temperature, soil P sorption capacity and oxalate-extractable aluminium (Alox) and iron (Feox) on the concentration of different soil P fractions. We hypothesized that the concentration of labile P fractions would decrease with increasing elevation (and thus declining temperature), but would be lower in meadow than in heath, given that N to P ratios in meadow foliage are higher. As expected, labile P in the form of Resin-P declined sharply with elevation for both vegetation types. Meadow soils did not have lower concentrations of Resin-P than heath soils, but they did have 2-fold and 1.5-fold higher concentrations of NaOH-extractable organic P and Residual P, respectively. Further, meadow soils had 3-fold higher concentrations of Alox + Feox and a 20% higher P sorption index than did heath soils. Additionally, Resin-P expressed as a proportion of total soil P for the meadow was on average half that in the heath. Declining Resin-P concentrations with elevation were best explained by an associated 2.5-3.0 °C decline in temperature. In contrast, the lower P availability in meadow relative to heath soils may be associated with impaired organic P mineralization, as indicated by a higher accumulation of organic P and P sorption capacity. Our results indicate that predicted temperature increases in the arctic over the next century may influence P availability and biogeochemistry, with consequences for key ecosystem processes limited by P, such as primary productivity.

  1. Temporal changes in soil bacterial diversity and humic substances degradation in subarctic tundra soil.

    Science.gov (United States)

    Park, Ha Ju; Chae, Namyi; Sul, Woo Jun; Lee, Bang Yong; Lee, Yoo Kyung; Kim, Dockyu

    2015-04-01

    Humic substances (HS), primarily humic acids (HA) and fulvic acids (FA), are the largest constituent of soil organic matter. In microcosm systems with subarctic HS-rich tundra soil (site AK 1-75; approximately 5.6 °C during the thawing period) from Council, Alaska, the HA content significantly decreased to 48% after a 99-day incubation at 5 °C as part of a biologically mediated process. Accordingly, levels of FA, a putative byproduct of HA degradation, consistently increased to 172% during an identical incubation process. Culture-independent microbial community analysis showed that during the microcosm experiments, the relative abundance of phyla Proteobacteria (bacteria) and Euryarchaeota (archaea) largely increased, indicating their involvement in HS degradation. When the indigenous bacteria in AK 1-75 were enriched in an artificial mineral medium spiked with HA, the changes in relative abundance were most conspicuous in Proteobacteria (from 60.2 to 79.0%), specifically Betaproteobacteria-related bacteria. One hundred twenty-two HA-degrading bacterial strains, primarily from the genera Paenibacillus (phylum Firmicutes) and Pseudomonas (class Gammaproteobacteria), were cultivated from AK 1-75 and nearby sites. Through culture-dependent analysis with these bacterial isolates, we observed increasing HS-degradation rates in parallel with rising temperatures in a range of 0 °C to 20 °C, with the most notable increase occurring at 8 °C compared to 6 °C. Our results indicate that, although microbial-mediated HS degradation occurs at temperature as low as 5 °C in tundra ecosystems, increasing soil temperature caused by global climate change could enhance HS degradation rates. Extending the thawing period could also increase degradation activity, thereby directly affecting nearby microbial communities and rhizosphere environments.

  2. American mastodon extirpation in the Arctic and Subarctic predates human colonization and terminal Pleistocene climate change.

    Science.gov (United States)

    Zazula, Grant D; MacPhee, Ross D E; Metcalfe, Jessica Z; Reyes, Alberto V; Brock, Fiona; Druckenmiller, Patrick S; Groves, Pamela; Harington, C Richard; Hodgins, Gregory W L; Kunz, Michael L; Longstaffe, Fred J; Mann, Daniel H; McDonald, H Gregory; Nalawade-Chavan, Shweta; Southon, John R

    2014-12-30

    Existing radiocarbon ((14)C) dates on American mastodon (Mammut americanum) fossils from eastern Beringia (Alaska and Yukon) have been interpreted as evidence they inhabited the Arctic and Subarctic during Pleistocene full-glacial times (∼ 18,000 (14)C years B.P.). However, this chronology is inconsistent with inferred habitat preferences of mastodons and correlative paleoecological evidence. To establish a last appearance date (LAD) for M. americanum regionally, we obtained 53 new (14)C dates on 36 fossils, including specimens with previously published dates. Using collagen ultrafiltration and single amino acid (hydroxyproline) methods, these specimens consistently date to beyond or near the ∼ 50,000 y B.P. limit of (14)C dating. Some erroneously "young" (14)C dates are due to contamination by exogenous carbon from natural sources and conservation treatments used in museums. We suggest mastodons inhabited the high latitudes only during warm intervals, particularly the Last Interglacial [Marine Isotope Stage (MIS) 5] when boreal forests existed regionally. Our (14)C dataset suggests that mastodons were extirpated from eastern Beringia during the MIS 4 glacial interval (∼ 75,000 y ago), following the ecological shift from boreal forest to steppe tundra. Mastodons thereafter became restricted to areas south of the continental ice sheets, where they suffered complete extinction ∼ 10,000 (14)C years B.P. Mastodons were already absent from eastern Beringia several tens of millennia before the first humans crossed the Bering Isthmus or the onset of climate changes during the terminal Pleistocene. Local extirpations of mastodons and other megafaunal populations in eastern Beringia were asynchrononous and independent of their final extinction south of the continental ice sheets.

  3. Cryoprotectants and extreme freeze tolerance in a subarctic population of the wood frog.

    Science.gov (United States)

    Costanzo, Jon P; Reynolds, Alice M; do Amaral, M Clara F; Rosendale, Andrew J; Lee, Richard E

    2015-01-01

    Wood frogs (Rana sylvatica) exhibit marked geographic variation in freeze tolerance, with subarctic populations tolerating experimental freezing to temperatures at least 10-13 degrees Celsius below the lethal limits for conspecifics from more temperate locales. We determined how seasonal responses enhance the cryoprotectant system in these northern frogs, and also investigated their physiological responses to somatic freezing at extreme temperatures. Alaskan frogs collected in late summer had plasma urea levels near 10 μmol ml-1, but this level rose during preparation for winter to 85.5 ± 2.9 μmol ml-1 (mean ± SEM) in frogs that remained fully hydrated, and to 186.9 ± 12.4 μmol ml-1 in frogs held under a restricted moisture regime. An osmolality gap indicated that the plasma of winter-conditioned frogs contained an as yet unidentified osmolyte(s) that contributed about 75 mOsmol kg-1 to total osmotic pressure. Experimental freezing to -8°C, either directly or following three cycles of freezing/thawing between -4 and 0°C, or -16°C increased the liver's synthesis of glucose and, to a lesser extent, urea. Concomitantly, organs shed up to one-half (skeletal muscle) or two-thirds (liver) of their water, with cryoprotectant in the remaining fluid reaching concentrations as high as 0.2 and 2.1 M, respectively. Freeze/thaw cycling, which was readily survived by winter-conditioned frogs, greatly increased hepatic glycogenolysis and delivery of glucose (but not urea) to skeletal muscle. We conclude that cryoprotectant accrual in anticipation of and in response to freezing have been greatly enhanced and contribute to extreme freeze tolerance in northern R. sylvatica.

  4. Climate change and mercury accumulation in Canadian high and subarctic lakes.

    Science.gov (United States)

    Kirk, Jane L; Muir, Derek C M; Antoniades, Dermot; Douglas, Marianne S V; Evans, Marlene S; Jackson, Togwell A; Kling, Hedy; Lamoureux, Scott; Lim, Darlene S S; Pienitz, Reinhard; Smol, John P; Stewart, Kailey; Wang, Xiaowa; Yang, Fan

    2011-02-01

    Mercury (Hg) profiles were compared to profiles of climate indicators including microfossil remains and algal-derived or S2 carbon (C) in dated sediment cores from 14 lakes spanning latitudinal and longitudinal gradients across the Canadian high and subarctic. Hg fluxes increased postindustrialization (post-∼1850) in 11 of these lakes (postindustrialization Hg fluxes (ΔHgF(F)) = 2-24 μg m(-2) y(-1)). Correction of HgF(F) for catchment contributions demonstrated that Hg deposition originating from catchment-independent factors, such as atmospheric deposition, increased since industrialization in all 14 lakes. Several of these lakes also showed postindustrial shifts in algal assemblages consistent with climate-induced changes. Eleven lakes showed post-1850s increases in S2F(F), suggesting that lake primary productivity has recently increased in the majority of our sites (ΔS2F(F) = 0.1-4 g m(-2) y(-1)). Other studies have interpreted significant relationships between Hg:S2 concentrations in Arctic sediment as support for the algal scavenging hypothesis, which postulates that Hg fluxes to Arctic sediments are largely driven by S2. However, in six of our lakes we observed no Hg:S2 relationship, and in one lake a significant negative Hg:S2 relationship was observed due to increased Hg and decreased S2 C deposition during the postindustrialization period. In six of the seven lakes where a significant positive Hg:S2 relationship was observed, algal assemblages either did not change through time or the timing of the shifts did not correspond to changes in Hg deposition. Our results demonstrate that, although Arctic lakes are experiencing a myriad of changes, including increased Hg and S2 deposition or changing algal assemblages, increased lake primary productivity does not appear to be driving changes in Hg fluxes to sediments.

  5. Long-Term Acid-Generating and Metal Leaching Potential of a Sub-Arctic Oil Shale

    Directory of Open Access Journals (Sweden)

    Kathryn A. Mumford

    2014-04-01

    Full Text Available Shales are increasingly being exploited for oil and unconventional gas. Exploitation of sub-arctic oil shales requires the creation of gravel pads to elevate workings above the heaving effects of ground ice. These gravel pads can potentially generate acidic leachate, which can enhance the mobility of metals from the shale. To examine this potential, pyrite-bearing shale originating from sub-Arctic gravel pad sites were subjected to leaching tests for 600 days at initial pH values ranging from 2 to 5, to simulate potential real world conditions. At set times over the 600 day experiment, pH, oxidation reduction potential (ORP, dissolved oxygen and temperature were recorded and small liquid samples withdrawn and analysed for elemental concentrations using total reflection X-ray fluorescence spectrometry (TRXRF. Six of eight shale samples were found to be acid generating, with pH declining and ORP becoming increasingly positive after 100 days. Two of the eight shale samples produced increasingly alkaline leachate conditions with relatively low ORP after 100 days, indicating an inbuilt buffering capacity. By 600 days the buffering capacity of all samples had been consumed and all leachate samples were acidic. TRXRF analyses demonstrated significant potential for the leaching of S, Fe, Ni, Cu, Zn and Mn with greatest concentrations found in reaction vessels with most acidic pH and highest ORP.

  6. Population dynamics of Empetrum hermaphroditum (Ericaceae) on a subarctic sand dune: Evidence of rapid colonization through efficient sexual reproduction.

    Science.gov (United States)

    Boudreau, Stéphane; Ropars, Pascale; Harper, Karen Amanda

    2010-05-01

    The importance of sexual reproduction for clonal plant species has long been underestimated, perhaps as a consequence of the difficulty in identifying individuals, preventing the study of their population dynamics. Such is the case for Empetrum hermaphroditum, an ericaceous species, which dominates the ground vegetation of subarctic ecosystems. Despite abundant seed production, seedlings are rarely observed. Therefore, prevalent seedling recruitment on a subarctic dune system provided an opportunity to study the population dynamics and spatial pattern of the colonization phase of this species. We established a 6-ha grid on the dune systems that extended from the shoreline to the fixed dunes and mapped and measured all E. hermaphroditum individuals in the grid. Moreover, we sampled 112 individuals just outside the grid to identify any allometric relationship between the size and age of the individuals, which allowed us to reconstruct population expansion. The overall size structure suggests that the population is still expanding. In the last 50 yr, E. hermaphroditum advanced more than 200 m in the dune system. Expansion started in the 1960s simultaneously at different distances from the shoreline. Colonization did not proceed gradually from the fixed dune toward the shoreline but instead individuals established earlier in the troughs between the dunes, with an increasingly clumped spatial pattern as the population filled in with time.

  7. CO2 and CH4 in sea ice from a subarctic fjord under influence of riverine input

    DEFF Research Database (Denmark)

    Crabeck, O.; Delille, B.; Thomas, D. N.

    2014-01-01

    We present CH4 concentration [CH4] and the partial pressure of CO2 (pCO2) in bulk sea ice from subarctic, land-fast sea ice in the Kapisillit fjord, Greenland. The bulk ice [CH4] ranged from 1.8 to 12.1 nmol L−1, which corresponds to a partial pressure range of 3 to 28 ppmv. This is markedly higher...... than the average atmospheric methane content of 1.9 ppmv. Most of the trapped methane within the sea ice was evidently contained inside bubbles, and only a minor portion was dissolved in the brine. The bulk ice pCO2 ranged from 60 to 330 ppmv showing that sea ice at temperatures above −4 °C is under......-saturated compared to the atmosphere (390 ppmv). Our study adds to the few existing studies of CH4 and CO2 in sea ice and concludes that sub-arctic sea can be a sink for atmospheric CO2, while being a net source of CH4. Processes related to the freezing and melting of sea ice represents large unknowns...

  8. Online Resources

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Genetics; Online Resources. Journal of Genetics. Online Resources. Volume 96. 2017 | Online resources. Volume 95. 2016 | Online resources. Volume 94. 2015 | Online resources. Volume 93. 2014 | Online resources. Volume 92. 2013 | Online resources. Volume 91. 2012 | Online resources ...

  9. Comparison of aerosol optical properties at the sub-arctic stations ALOMAR-Andenes, Abisko and Sodankylä in late spring and summer 2007

    NARCIS (Netherlands)

    Rodríguez, E.; Toledano, C.; Cachorro, V.; Leeuw, G. de; Frutos, A.de; Gausa, M.; Holben, B.

    2012-01-01

    Aerosol concentration and aerosol type, retrieved from observations with CIMEL sun-photometers at three sub-arctic locations at the Scandinavian Peninsula are presented. The observations were made at ALOMAR-Andenes in Norway, Abisko in Sweden and Sodankylä in Finland. This field campaign took place

  10. Soil warming and fertilization altered rates of nitrogen transformation processes and selected for adapted ammonia-oxidizing archaea in sub-arctic grassland soil

    NARCIS (Netherlands)

    Daebeler, Anne; Bodelier, Paul L.E.; Hefting, Mariet M.; Rütting, Tobias; Laanbroek, Hendrikus J.

    Abstract The balance of microbial nitrogen (N) transformation processes in sub-arctic terrestrial ecosystems is most likely affected by global change, with potential feedbacks to greenhouse gas emissions and eutrophication. Soil temperature and N availability – their global increases being two of

  11. Analyzing tree cores to detect petroleum hydrocarbon-contaminated groundwater at a former landfill site in the community of Happy Valley-Goose Bay, eastern Canadian subarctic

    DEFF Research Database (Denmark)

    Fonkwe, Merline L D; Trapp, Stefan

    2016-01-01

    This research examines the feasibility of analyzing tree cores to detect benzene, toluene, ethylbenzene, and m, p, o-xylene (BTEX) compounds and methyl tertiary-butyl ether (MTBE) in groundwater in eastern Canada subarctic environments, using a former landfill site in the remote community of Happ...

  12. Library resources on the Internet

    Science.gov (United States)

    Buchanan, Nancy L.

    1995-07-01

    Library resources are prevalent on the Internet. Library catalogs, electronic books, electronic periodicals, periodical indexes, reference sources, and U.S. Government documents are available by telnet, Gopher, World Wide Web, and FTP. Comparatively few copyrighted library resources are available freely on the Internet. Internet implementations of library resources can add useful features, such as full-text searching. There are discussion lists, Gophers, and World Wide Web pages to help users keep up with new resources and changes to existing ones. The future will bring more library resources, more types of library resources, and more integrated implementations of such resources to the Internet.

  13. Using 67Cu to study the biogeochemical cycling of copper in the northeast subarctic Pacific Ocean

    Directory of Open Access Journals (Sweden)

    David M Semeniuk

    2016-06-01

    Full Text Available Microbial copper (Cu nutrition and dissolved Cu speciation were surveyed along Line P, a coastal to open ocean transect that extends from the coast of British Columbia, Canada, to the high-nutrient-low-chlorophyll (HNLC zone of the northeast subarctic Pacific Ocean. Steady-state size fractionated Cu uptake rates and Cu:C assimilation ratios were determined at in situ Cu concentrations and speciation using a 67Cu tracer method. The cellular Cu:C ratios that we measured (~30 µmol Cu mol C-1 are similar to recent estimates using synchrotron x-ray fluorescence (SXRF, suggesting that the 67Cu method can determine in situ metabolic Cu demands. We examined how environmental changes along the Line P transect influenced Cu metabolism in the sub-microplankton community. Cellular Cu:C assimilation ratios and uptake rates were compared with net primary productivity, bacterial abundance and productivity, total dissolved Cu, Cu speciation, and a suite of other chemical and biological parameters. Total dissolved Cu concentrations ([Cu]d were within a narrow range (1.46 to 2.79 nM, and Cu was bound to a ~5-fold excess of strong ligands with conditional stability constants ( of ~1014. Free Cu2+ concentrations were low (pCu 14.4 to 15.1, and total and size fractionated net primary productivity (NPPV; µg C L-1 d-1 were negatively correlated with inorganic Cu concentrations ([Cu′]. We suggest this is due to greater Cu′ drawdown by faster growing phytoplankton populations. Using the relationship between [Cu′] drawdown and NPPV, we calculated a regional photosynthetic Cu:C drawdown export ratio between 1.5 and 15 µmol Cu mol C-1, and a mixed layer residence time (2.5 to 8 years that is similar to other independent estimates (2-12 years. Total particulate Cu uptake rates were between 22 and 125 times faster than estimates of Cu export; this is possibly mediated by rapid cellular Cu uptake and efflux by phytoplankton and bacteria or the effects of grazers and

  14. Mapping the reduction in gross primary productivity in subarctic birch forests due to insect outbreaks

    Science.gov (United States)

    Olsson, Per-Ola; Heliasz, Michal; Jin, Hongxiao; Eklundh, Lars

    2017-03-01

    It is projected that forest disturbances, such as insect outbreaks, will have an increasingly negative impact on forests with a warmer climate. These disturbance events can have a substantial impact on forests' ability to absorb atmospheric CO2, and may even turn forests from carbon sinks into carbon sources; hence, it is important to develop methods both to monitor forest disturbances and to quantify the impact of these disturbance events on the carbon balance. In this study we present a method to monitor insect-induced defoliation in a subarctic birch forest in northern Sweden, and to quantify the impact of these outbreaks on gross primary productivity (GPP). Since frequent cloud cover in the study area requires data with high temporal resolution and limits the use of finer spatial resolution sensors such as Landsat, defoliation was mapped with remote sensing data from the MODIS sensor with 250 m × 250 m spatial resolution. The impact on GPP was estimated with a light use efficiency (LUE) model that was calibrated with GPP data obtained from eddy covariance (EC) measurements from 5 years with undisturbed birch forest and 1 year with insect-induced defoliation. Two methods were applied to estimate the impact on GPP: (1) applying a GPP reduction factor derived from EC measured GPP to estimate GPP loss, and (2) running a LUE model for both undisturbed and defoliated forest and deriving the differences in modelled GPP. In the study area of 100 km2 the results suggested a substantial setback to the carbon uptake: an average decrease in regional GPP over the three outbreak years (2004, 2012, and 2013) was estimated to 15 ± 5 Gg C yr-1, compared to the mean regional GPP of 40 ± 12 Gg C yr-1 for the 5 years without defoliation, i.e. 38 %. In the most severe outbreak year (2012), 76 % of the birch forests were defoliated, and annual regional GPP was merely 50 % of GPP for years without disturbances. The study has generated valuable data on GPP reduction, and

  15. Carbon dioxide balance of subarctic tundra from plot to regional scales

    Directory of Open Access Journals (Sweden)

    M. E. Marushchak

    2013-01-01

    Full Text Available We report here the carbon dioxide (CO2 budget of a 98.6 km2 subarctic tundra area in northeast European Russia based on measurements at two different scales and two independent upscaling approaches. Plot-scale measurements (chambers on terrestrial surfaces, gas gradient method and bubble collectors on lakes were carried out from July 2007 to October 2008. The landscape-scale eddy covariance (EC measurements covered the snow-free period of 2008. The annual net ecosystem exchange (NEE of different land cover types ranged from −251 to 84 g C m−2. Leaf area index (LAI was an excellent predictor of the spatial variability in gross photosynthesis (GP, NEE and ecosystem respiration (ER. The plot-scale CO2 fluxes were first scaled up to the EC source area and then to the whole study area using two data sets: a land cover classification and a LAI map, both based on field data and a 2.4 m pixel-sized QuickBird satellite image. The good agreement of the CO2 balances for the EC footprint based on the different measuring techniques (−105 to −81 g C m−2 vs. −79 g C m−2; growing season 2008 justified the integration of the plot-scale measurements over the larger area. The regional CO2 balance based on area-integrated plot-scale measurements was −41 or −79 g C m−2 yr−1 according to the two upscaling methods, the land cover classification and the LAI map, respectively. Due to the heterogeneity of tundra, the effect of climate change on CO2 uptake will vary strongly according to the land cover type and, moreover, likely changes in their relative coverage in the future will have great impact on the regional CO2 balance.

  16. [Impact of industrial pollution on emission of carbon dioxide by soils in the Kola Subarctic Region].

    Science.gov (United States)

    Koptsik, G N; Kadulin, M S; Zakharova, A I

    2015-01-01

    Soil emission of carbon dioxide, the key component of carbon cycle and the characteristic of soil biological activity, has been studied in background and polluted ecosystems in the Kola subarctic, the large industrial region of Russia. Long-term air pollution by emissions of "Pechenganikel" smelter, the largest source of sulphur dioxide and heavy metals in Northern Europe, has caused the technogenic digression of forest ecosystems. As a result of the digression, the tree layer was destructed, the number of plant species was diminished, the activity of soil biota was weakened, the soils were polluted and exhausted, biogeochemical cycles of elements were disturbed and productivity of ecosystems shrunk. Field investigations revealed the decrease of the in.situ soil respiration in average from 190-230 mg C-CO2/m2 x per h in background pine forests to 130-160, 100, and 20 mg C-CO2/m2.per h at the stages of pine defoliation, sparse pine forest and technogenic barrens of the technogenic succession, respectively. The soil respira- tion in birch forests was more intense than in pine forests and tended to decrease from about 290 mg C-CO2/m2 x per h in background forests to 210-220 and 170-190 mg C-CO2/m2 x per h in defoliating forests and technogenic sparse forests, respectively. Due to high spatial variability of soil respiration in both pine and birch forests significant differences from the background level were found only in technogenic sparse forests and barrens. Soil respiration represents total production of carbon dioxide by plant roots and soil microorganisms. The decrease in share of root respiration in the total soil respiration with the rise of pollution from 38-57% in background forests up to zero in technogenic barrens has been revealed for the first time for this region. This indicates that plants seem to be more sensitive to pollution as compared to relatively resistant microorganisms. Soil respiration and the contribution of roots to the total respiration

  17. Quantifying landscape-level methane fluxes in subarctic Finland using a multiscale approach.

    Science.gov (United States)

    Hartley, Iain P; Hill, Timothy C; Wade, Thomas J; Clement, Robert J; Moncrieff, John B; Prieto-Blanco, Ana; Disney, Mathias I; Huntley, Brian; Williams, Mathew; Howden, Nicholas J K; Wookey, Philip A; Baxter, Robert

    2015-10-01

    Quantifying landscape-scale methane (CH4 ) fluxes from boreal and arctic regions, and determining how they are controlled, is critical for predicting the magnitude of any CH4 emission feedback to climate change. Furthermore, there remains uncertainty regarding the relative importance of small areas of strong methanogenic activity, vs. larger areas with net CH4 uptake, in controlling landscape-level fluxes. We measured CH4 fluxes from multiple microtopographical subunits (sedge-dominated lawns, interhummocks and hummocks) within an aapa mire in subarctic Finland, as well as in drier ecosystems present in the wider landscape, lichen heath and mountain birch forest. An intercomparison was carried out between fluxes measured using static chambers, up-scaled using a high-resolution landcover map derived from aerial photography and eddy covariance. Strong agreement was observed between the two methodologies, with emission rates greatest in lawns. CH4 fluxes from lawns were strongly related to seasonal fluctuations in temperature, but their floating nature meant that water-table depth was not a key factor in controlling CH4 release. In contrast, chamber measurements identified net CH4 uptake in birch forest soils. An intercomparison between the aerial photography and satellite remote sensing demonstrated that quantifying the distribution of the key CH4 emitting and consuming plant communities was possible from satellite, allowing fluxes to be scaled up to a 100 km(2) area. For the full growing season (May to October), ~ 1.1-1.4 g CH4  m(-2) was released across the 100 km(2) area. This was based on up-scaled lawn emissions of 1.2-1.5 g CH4  m(-2) , vs. an up-scaled uptake of 0.07-0.15 g CH4  m(-2) by the wider landscape. Given the strong temperature sensitivity of the dominant lawn fluxes, and the fact that lawns are unlikely to dry out, climate warming may substantially increase CH4 emissions in northern Finland, and in aapa mire regions in general. © 2015 The

  18. Paleo-iron supply to the Western Subarctic Pacific since the last glaciation

    Science.gov (United States)

    Lam, P. J.; Robinson, L. F.; Blusztajn, J.; McManus, J. F.; Cook, M. S.; Keigwin, L. D.

    2011-12-01

    A strong and pervasive productivity peak has been observed in cores around the North Pacific during the Bølling-Allerød warm period of the last deglaciation. Recently, it has been hypothesized that this peak may have been caused by an influx of iron from the continental shelves as they were flooded during the deglaciation (1). Here, we examine this hypothesis by reconstructing the flux and sources of detrital material to a sediment core from the Detroit seamount (Vinogradov 19/4 GGC-37, 50.4°N, 167.7°E, 3300m) in the Western Subarctic Pacific since the last glacial maximum (LGM), and compare to several proxies of paleo-productivity. We use 230Th-normalization to reconstruct the flux of biogenic and detrital material, and the neodymium and strontium isotopic compositions to distinguish between volcanic margin and continental loess sources of detrital material. We find that total detrital flux is highest during the last glacial maximum and early deglacial periods, a time of relatively low productivity, with approximately equal contributions from the volcanic margin and from continental loess. Total detrital flux starts to decline around 16kya, but increases again to 80% of the glacial maximum flux around the time of the Bølling-Allerød productivity peak. The local deglacial maximum in detrital flux coincides with a maximum in authigenic uranium, and immediately precedes maxima in opal flux, carbonate flux, benthic foraminifera abundance, and excess 231Pa/230Th. While the local deglacial maximum in detrital flux is consistent with iron stimulation of productivity, we conclude that iron supply alone is not sufficient to explain the deglacial productivity peak, since glacial times exhibited low productivity despite high detrital flux. Further, the relative and absolute contributions of detrital material of volcanic origin is lower during the deglaciation than during the LGM, suggesting that loess may have contributed more iron during the deglacial productivity

  19. Effects of Permafrost Thaw on Net Ecosystem Carbon Balance in a Subarctic Peatland

    Science.gov (United States)

    Wang, Z.; Roulet, N. T.; Moore, T. R.

    2014-12-01

    This research is to assess changes in net ecosystem carbon balance (NECB) with permafrost thaw in northern peatland: in particular how changes in C biogeochemistry influence NECB. Thawed transects associated with varying stages of permafrost thaw: from palsas with intact permafrost (P), through edge of palsa (EP), dry lawn (DL), wet lawn (WL), edge of thawed pond (ET), pond sedges (PS), to several thawed ponds (TP) in a subarctic peatland in northern Quebec were sampled in the snow free seasons of 2013 and 2014. The exchange of CO2 and CH4, vegetation, dissolved organic C (DOC) concentration and biodegradability, active layer depth, air and peat temperatures, water table depth (WT), pH, and conductivity were measured. Peat temperatures were quite similar among different locations, but the WT decreased significantly along the transect creating varied environmental conditions that supporting different plant communities. From dry to wet area, vegetation abundance and biomass showed reductions of shrubs and lichens, and increases of Sphagnum, grasses and sedges. Pore water pH increased from dry to wet area, and conductivity slightly decreased. Wet thaw area WL, ET and PS had relatively higher season gross ecosystem production (GEP) and higher season ecosystem respiration (ER), but relative similar net ecosystem CO2 exchange (NEE). Only TP had a significant higher positive season NEE. Palsa was the only CH4 sink, and quite high CH4 emissions were found after it thawed. CH4-C release significantly increased from dry to wet in thawed area, which even several times bigger than total C exchange in ET and PS. Generally, wet area had higher DOC concentration and higher DOC biodegradability indicated by lower SUVA254 (except PS which received great influence from pond). All components in the NECB (GEP, ER, CH4, DOC) increased significantly in magnitude from palsa to wet thawed area, and ecosystem C sink turned into source as palsa thawed into PS and TP. These results

  20. Herpes - resources

    Science.gov (United States)

    Genital herpes - resources; Resources - genital herpes ... following organizations are good resources for information on genital herpes : March of Dimes -- www.marchofdimes.com/pregnancy/complications- ...

  1. Natural resource management: implications for global warming

    Energy Technology Data Exchange (ETDEWEB)

    Shen, S. (Harvard University, Cambridge, MA (USA))

    1990-01-01

    The opportunities offered by the global warming alert for global natural resource management are reviewed. The author systematically introduced a new discipline of managing risks involved in local large scale climatic swings which is based on international and interdisciplinary transfer of knowledge, benefiting citizens of industrialized nations, the industrializing nations, as well as the developing nations. Several programs to utilize the opportunities are outlined, including (A) the monitoring of increased availability of forest land in the circumpolar subarctic area, (B) the deployment of biologically engineered reforestation methods and (C) the production of grain-based and wood based liquid fuel and plastic feedstock to tackle the new energy crisis. Policies must represent collective wisdom in the socio-economic as well as scientific contexts. Newly industralized countries must take into account the existing energy politics which affects energy economics and energy and material security. The paramount importance of the ability to use thermodynamically sound technologies and technologies that are based on renewable resources is to be recognized. The choice of technology must be based on the technology's material and energy efficiency. The basic philosophy of cooperation between nations and coordination of activities to improve resource management in the long term must be based on a responsibility system applicable internationally, and an understanding of resource management that can be translated into policy action. Transboundary environmental and economic development problems are best solved regionally by a regional band of nations. 30 refs.

  2. Analysis on Current Situation and Countermeasure of Domestic Electronic Commerce Logistics in the Internet Age——Based on Resource Dependence Theory

    Directory of Open Access Journals (Sweden)

    Zhang Jiapeng

    2017-01-01

    Full Text Available This paper analyzes the status of electric business logistics in the current Internet era in China, and combines the SWOT analysis with AHP to do the empirical analysis, then puts forward the countermeasure that the electric business logistics resource should be shared based on the resource dependence theory. Through the empirical analysis, it is found that the disadvantages and opportunities of the logistics status are important in the Internet era.The resource sharing strategy based on the resource dependence theory is more scientific. The rational use of Internet technology in electric business logistics industry can achieve “sharing”. It is of great significance for its balanced development, intelligent development and optimization and development.

  3. Reindeer grazing in subarctic boreal forest - influences on the soil carbon dynamics

    Science.gov (United States)

    Koster, Kajar; Berninger, Frank; Köster, Egle; Pumpanen, Jukka

    2015-04-01

    Reindeer (Rangifer tarandus L.) are the most important large mammalian herbivores in the northern ecosystems , which have many effects on plant diversity, soil nutrient cycling and soil organic matter decomposition. Changes caused by reindeer in vegetation have indirect effects on physical features of the soil e.g. soil microclimate, root biomass and also on soil C dynamics. Earlier, the role of reindeer grazing in ground vegetation dynamics and in soil carbon (C) dynamics has been mostly investigated in open tundra heaths. The objectives of this study were to examine if and how the reindeer grazing (and the possible temperature changes in soil caused by heavy grazing) is affecting the soil C dynamics (CO2 efflux from the soil, C storage in soil, microbial biomass in the soil). In a field experiment in Finnish Lapland, in Värriö Strict Nature Reserve (67° 46' N, 29° 35' E) we have assessed the changes occurring in above- and belowground biomasses, and soil C dynamics (CO2 efflux, soil C content, soil microbial biomass C) among areas grazed and ungrazed by reindeer. Our study areas are located in the northern boreal subarctic coniferous forest at the zone of the last intact forest landscapes in Fennoscandia, where large areas of relatively undisturbed subarctic Scots pine (Pinus sylvestris L.) forests can still be found. The sample plots located in the Värriö Strict Nature Reserve (10 sample plots in total established in year 2013) are situated along the borderline between Finland and Russia, where the ungrazed area was excluded from the reindeer grazing already in 1918, to prevent the Finnish reindeer from going to the Russian side and there are not many reindeer on Russian side of the area. To characterize the stands we have established circular sample plots on areas with a radius of 11.28 m, where different tree characteristics were measured (diameter at 1.3 m, height, height of a tree, crown height, crown diameter, stand age, etc.). On every sample plot

  4. Prokaryotic Community Composition in Arctic Kongsfjorden and Sub-Arctic Northern Bering Sea Sediments As Revealed by 454 Pyrosequencing

    Directory of Open Access Journals (Sweden)

    Yin-Xin Zeng

    2017-12-01

    Full Text Available Fjords and continental shelves represent distinct marine ecosystems in the pan-arctic region. Kongsfjorden is a glacial fjord that is located on the west coast of Svalbard, and is influenced by both Atlantic and Arctic water masses. The Bering Sea consists of a huge continental shelf in the northeast and a deep ocean basin in the southwest, and is influenced by Pacific water. Microbial community compositions of Arctic sediment samples BJ4 from outer basin and BJ36 from inner basin of Kongsfjorden and sub-Arctic samples NEC5 from shallow shelf and DBS1 from deep basin region of the northern Bering Sea were investigated using 454 pyrosequencing of archaeal and bacterial 16S rRNA genes. Most archaeal sequences in the sediments were related to Thaumarchaeota, though Euryarchaeota were more abundant in the Arctic glacier-influencing inner basin sediment BJ36. Thaumarchaeota Group C3 was the dominant archaeal population in all samples. Proteobacteria and Bacteroidetes dominated the sediment bacterial communities. Acidobacteria and Actinobacteria were also dominant in the northern Bering Sea samples. Alphaproteobacteria and Epsilonproteobacteria were the two main classes in Kongsfjorden sediment bacterial communities while Deltaproteobacteria and Gammaproteobacteria were dominant in the northern Bering Sea sediments. Differences in the presence and abundance of other dominant archaeal and bacterial populations were observed among sediment samples. In contrast to archaeal community differences that the Arctic BJ36 archaeal community was distinct from the sub-Arctic sediments and the Arctic outer basin sediment BJ4, cluster analysis based on bacterial OTU (operational taxonomic unit distributions indicated that the Arctic and sub-Arctic bacterial communities segregated from one another. These results suggest that the sediment archaeal and bacterial community compositions can be driven by different environmental factors. Differences in the presence and

  5. Examining the relationship between mercury and organic matter in lake sediments along a latitudinal transect in subarctic Canada

    Science.gov (United States)

    Galloway, Jennifer M.; Sanei, Hamed; Parsons, Michael; Swindles, Graeme T.; Macumber, Andrew L.; Patterson, R. Timothy; Palmer, Michael; Falck, Hendrik

    2016-04-01

    The accumulation of Hg in aquatic environments at both high and low latitudes can be controlled by organic matter through algal scavenging, thus complicating the interpretation of historical Hg profiles in lake sediments1,2,3. However, other recent studies suggest that algal scavenging is not important in governing Hg flux to sediments4, in some cases because of dilution by inorganic materials5. This study examines relationships between Hg and organic matter (OM) in over 100 lakes located between 60.5 and 65.4 °N and crossing the latitudinal tree-line in subarctic Canada. The latitudinal gradient approach in our study offers an opportunity to better understand climate and environmental controls on OM accumulation and its role in influencing Hg deposition in subarctic lacustrine environments. We used Rock Eval 6 pyrolysis to determine total organic carbon (TOC%), S1 (soluble OM consisting of degradable lipids and algal pigments), S2 (OM derived from highly aliphatic biomacromolecule structure of algal cell walls), and S3 (OM dominated by carbohydrates, lignins, and plant materials). Total Hg in sediments was measured using thermal decomposition, amalgamation, and atomic absorption spectrophotometry. In these lake sediments, S2 composes the majority of TOC (Pearson's r = 0.978, pEnviron Sci Technol 41: 5259-65. 3Wu, F., Zu, L., Liao, H., Guo, F., Zhao, X., Giesy, J. 2013. Relationship between mercury and organic carbon in sediment cores from Lakes Qinghai and Chenghai, China. J Soils Sediments 13: 1084-1092.4Kirk, J.L., Muir, D.C.G., Antoniades, D., Douglas, M.S.V., Evans, M.S., Jackson, T.A., Kling, H., Lamoureux, S., Lim, D.S.S., Pienitz, R., Smol, J.P., Stewart, K., Wang, X., Yang, F. 2011. Response to comment on climate change and mercury accumulation in Canadian high and subarctic lakes. Environ Sci Technol 45: 6705-06.5Deison, R., Smol, J.P., Kokelj, S.V., Pisaric, M.F.J., Kimpe, L.E., Poulain, A.J., Sanei, H., Theinpoint, J.R., Blais, J.M. 2012. Spatial and

  6. Plant performance and soil nitrogen mineralization in response to simulation climate change in subarctic dwarf shrub heath

    Energy Technology Data Exchange (ETDEWEB)

    Hartley, A.E.; Neill, C.; Melillo, J.M.; Crabtree, R.; Bowles, F.P. [Marine Biological Lab., Ecosystems Center, Woods Hole, MA (United States)

    1999-08-01

    To simulate a future, warmer climate, we subjected subarctic dwarf shrub heath to 5 deg. C direct soil warming for five consecutive growing seasons (1993-1997). Supplemental air warming treatments vere imposed on warmed soil by plastic tents in 1994 and open-top chambers in 1995. Plant responses to warming were assessed by changes in: (1) shrub phenology. (2) current-year aboveground biomass in the dominant shrubs (Empetrum hermaphroditum, Vaccinium myrtillus, V. uliginosum and V. vitis-idaea), and (3) vascular and nonvascular plant cover. We estimated warming effects on soil nitrogen (N) availability by in situ buried bag incubation of soils. Soil warming stimulated soil N cycling and shrub growth and development in the short term (2-3 yr). In the second lear, net N mineralization rates doubled in warmed soil (4.3 kg N ha{sup -1} season{sup -1} in untreated soil vs 9.2 kg ha{sup -1} season{sup -1}). Greater N availability likely contributed to the observed 62% increase in current-year growth of V. myrtillus the dominant deciduous shrub. In the third year, soil and air warming increased shoot production by > 80% in the evergreen shrubs V. vitis-idaea and E. hermaphroditum. Soil warming had no detectable effects on plant growth or soil N cycling in the fifth year, suggesting that the long-term response may be less dramatic than short-term changes. Past fertilization studies in arctic and subarctic tundra reported an increase in the abundance of graminoids. Despite enhanced soil N mineralization in the second year we found that warming had little effect on plant community composition after five years. Even in an extreme climate warming scenario, it appears that subarctic soils mineralize an order of magnitude less N than was applied in fertilization experiments. High-dose fertilization studies provide insight into controls on plant communities, but do not accurately simulate increases in N availability predicted for a warmer climate. (au)

  7. Experimentally increased nutrient availability at the permafrost thaw front selectively enhances biomass production of deep-rooting subarctic peatland species.

    Science.gov (United States)

    Keuper, Frida; Dorrepaal, Ellen; van Bodegom, Peter M; van Logtestijn, Richard; Venhuizen, Gemma; van Hal, Jurgen; Aerts, Rien

    2017-10-01

    Climate warming increases nitrogen (N) mineralization in superficial soil layers (the dominant rooting zone) of subarctic peatlands. Thawing and subsequent mineralization of permafrost increases plant-available N around the thaw-front. Because plant production in these peatlands is N-limited, such changes may substantially affect net primary production and species composition. We aimed to identify the potential impact of increased N-availability due to permafrost thawing on subarctic peatland plant production and species performance, relative to the impact of increased N-availability in superficial organic layers. Therefore, we investigated whether plant roots are present at the thaw-front (45 cm depth) and whether N-uptake ((15) N-tracer) at the thaw-front occurs during maximum thaw-depth, coinciding with the end of the growing season. Moreover, we performed a unique 3-year belowground fertilization experiment with fully factorial combinations of deep- (thaw-front) and shallow-fertilization (10 cm depth) and controls. We found that certain species are present with roots at the thaw-front (Rubus chamaemorus) and have the capacity (R. chamaemorus, Eriophorum vaginatum) for N-uptake from the thaw-front between autumn and spring when aboveground tissue is largely senescent. In response to 3-year shallow-belowground fertilization (S) both shallow- (Empetrum hermaphroditum) and deep-rooting species increased aboveground biomass and N-content, but only deep-rooting species responded positively to enhanced nutrient supply at the thaw-front (D). Moreover, the effects of shallow-fertilization and thaw-front fertilization on aboveground biomass production of the deep-rooting species were similar in magnitude (S: 71%; D: 111% increase compared to control) and additive (S + D: 181% increase). Our results show that plant-available N released from thawing permafrost can form a thus far overlooked additional N-source for deep-rooting subarctic plant species and increase their

  8. Contrasting trends in floods for two sub-arctic catchments in northern Sweden – does glacier presence matter?

    Directory of Open Access Journals (Sweden)

    H. E. Dahlke

    2012-07-01

    Full Text Available Our understanding is limited to how transient changes in glacier response to climate warming will influence the catchment hydrology in the Arctic and Sub-Arctic. This understanding is particularly incomplete for flooding extremes because understanding the frequency of such unusual events requires long records of observation not often available for the Arctic and Sub-Arctic. This study presents a statistical analysis of trends in the magnitude and timing of flood extremes and the mean summer discharge in two sub-arctic catchments, Tarfala and Abisko, in northern Sweden. The catchments have different glacier covers (30% and 1%, respectively. Statistically significant trends (at the 5% level were identified for both catchments on an annual and on a seasonal scale (3-months averages using the Mann-Kendall trend test. Stationarity of flood records was tested by analyzing trends in the flood quantiles, using generalized least squares regression. Hydrologic trends were related to observed changes in the precipitation and air temperature, and were correlated with 3-months averaged climate pattern indices (e.g. North Atlantic oscillation. Both catchments showed a statistically significant increase in the annual mean air temperature over the comparison time period of 1985–2009 (Tarfala and Abisko p<0.01, but did not show significant trends in the total precipitation (Tarfala p = 0.91, Abisko p = 0.44. Despite the similar climate evolution over the studied period in the two catchments, data showed contrasting trends in the magnitude and timing of flood peaks and the mean summer discharge. Hydrologic trends indicated an amplification of the streamflow and flood response in the highly glacierized catchment and a dampening of the response in the non-glacierized catchment. The glacierized mountain catchment showed a statistically significant increasing trend in the flood magnitudes (p = 0.04 that is clearly correlated to the

  9. Contrasting trends in floods for two sub-arctic catchments in northern Sweden - does glacier presence matter?

    Science.gov (United States)

    Dahlke, H. E.; Lyon, S. W.; Stedinger, J. R.; Rosqvist, G.; Jansson, P.

    2012-07-01

    Our understanding is limited to how transient changes in glacier response to climate warming will influence the catchment hydrology in the Arctic and Sub-Arctic. This understanding is particularly incomplete for flooding extremes because understanding the frequency of such unusual events requires long records of observation not often available for the Arctic and Sub-Arctic. This study presents a statistical analysis of trends in the magnitude and timing of flood extremes and the mean summer discharge in two sub-arctic catchments, Tarfala and Abisko, in northern Sweden. The catchments have different glacier covers (30% and 1%, respectively). Statistically significant trends (at the 5% level) were identified for both catchments on an annual and on a seasonal scale (3-months averages) using the Mann-Kendall trend test. Stationarity of flood records was tested by analyzing trends in the flood quantiles, using generalized least squares regression. Hydrologic trends were related to observed changes in the precipitation and air temperature, and were correlated with 3-months averaged climate pattern indices (e.g. North Atlantic oscillation). Both catchments showed a statistically significant increase in the annual mean air temperature over the comparison time period of 1985-2009 (Tarfala and Abisko pflood peaks and the mean summer discharge. Hydrologic trends indicated an amplification of the streamflow and flood response in the highly glacierized catchment and a dampening of the response in the non-glacierized catchment. The glacierized mountain catchment showed a statistically significant increasing trend in the flood magnitudes (p = 0.04) that is clearly correlated to the occurrence of extreme precipitation events. It also showed a significant increase in mean summer discharge (p = 0.0002), which is significantly correlated to the decrease in glacier mass balance and the increase in air temperature (p = 0.08). Conversely, the non-glacierized catchment showed a

  10. Effects of freeze-thaw cycles on microarthropods and nutrient availability in a sub-arctic soil

    DEFF Research Database (Denmark)

    Sjursen, Heidi; Michelsen, Anders; Holmstrup, Martin

    2005-01-01

    content were examined. There was no conclusive evidence that recurring freeze-thaw events had a negative effect on the investigated soil faunal groups, and the treatment even seemed to stimulate the abundance of Acaridida. Respiration of soil subjected to 16 freeze-thaw cycles was low when kept at -2 °C......It is predicted that Arctic regions may experience an increase in mean temperature in the future. This will affect the frequency of severe climatic events such as summer droughts and freeze-thaw cycles. In order to understand the impact of recurring freezing and thawing on soil organisms...... and their environment, intact plant-soil samples from the sub-Arctic were subjected to a series of such events. Springtail and mite species composition and abundance were monitored at intervals throughout the experiment. Furthermore, nutrient content and mobilisation in the soil and soil microbial biomass and nutrient...

  11. Effects of litter addition and warming on soil carbon, nutrient pools and microbial communities in a subarctic heath ecosystem

    DEFF Research Database (Denmark)

    Rinnan, Riikka; Michelsen, Anders; Jonasson, Sven Evert

    2008-01-01

    Climatic warming leads to the expansion of deciduous shrubs and trees in the Arctic. This leads to higher leaf litter inputs, which together with warming may alter the rate of carbon and nutrient cycling in the arctic ecosystems. We assessed effects of factorial warming and additional litter...... on the soil ecosystem of a subarctic heath in a 7-year-long field experiment. Fine root biomass, dissolved organic carbon (DOC) and total C concentration increased in response to warming, which probably was a result of the increased vegetation cover. Litter addition increased the concentration of inorganic P...... in the uppermost 5 cm soil, while decreasing the pool of total P per unit area of the organic profile and having no significant effects on N concentrations or pools. Microbial biomass C and N were unaffected by the treatments, while the microbial biomass P increased significantly with litter addition. Soil...

  12. The long-term dynamics of hydrochemical indices of low-mineralized subarctic lakes in reducing the acid load

    Directory of Open Access Journals (Sweden)

    Kashulina T. G.

    2016-03-01

    Full Text Available The results of long-term studies (1990–2013 of dynamics of the main hydrochemical indices of the subarctic Shuonijavr Lake located in the zone of airborne pollution from a metallurgical plant have been considered. The following facts have been revealed: significant increase of alkalinity and acid neutralizing capacity (ANC of the lake water; reduction in the range of seasonal fluctuations of ph and alkalinity; reduction of in the lake water during the observation period as a result of reducing the acid load due to the decrease of SO2 emission. Despite the stabilization of the lake water ANC the pollution indicators in six elements of polluters foreground for the region remain high values

  13. Climate change-induced vegetation change as a driver of increased subarctic biogenic volatile organic compound emissions

    DEFF Research Database (Denmark)

    Valolahti, Hanna Maritta; Kivimäenpää, Minna; Faubert, Patrick

    2015-01-01

    to a fixed temperature,warming still had a significant effect suggesting that emissions were also indirectly increased. This indirect increaseappeared to result from increased plant coverage and changes in vegetation composition. The litter addition treat-ment also caused significant increases in the emission...... and stimulated microbial production of BVOCs. We suggest that the changes in the subarcticvegetation composition induced by climate warming will be the major factor indirectly affecting the BVOC emissionpotentials and composition.......Emissions of biogenic volatile organic compounds (BVOCs) have been earlier shown to be highly temperature sensi-tive in subarctic ecosystems. As these ecosystems experience rapidly advancing pronounced climate warming, weaimed to investigate how warming affects the BVOC emissions in the long term...

  14. Phytoplankton growth and microzooplankton grazing along a sub-Arctic fjord (Godthåbsfjord, West Greenland)

    DEFF Research Database (Denmark)

    Calbet, A.; Riisgaard, Karen; Saiz, E.

    2011-01-01

    we established four zones: i) Fyllas Bank, characterized by deep chl a maxima (ca. 30-40 m) consisting of large cells; ii) the mouth and main branch of the fjord, where phytoplankton was relatively homogeneously distributed in the upper 30 m layer; iii) inner waters influenced by glacial melt water......We evaluated the role of microzooplankton (sensu latto, grazers Greenland subarctic fjord, Godthåbfjord. Based on the distribution of size fractionated chlorophyll a (chl a) concentrations...... the nutrient rich waters in the upwelling area in the vicinity of the glacier. Most of the grazing impact was on the 20 µm microzooplankton, as deducted from additional dilution experiments removing > 20 µm. Overall, little...

  15. Improvement of state regulation of the agrarian sector of the sub-arctic and arctic areas under the WTO membership

    Directory of Open Access Journals (Sweden)

    Valentin Aleksandrovich Ivanov

    2015-01-01

    Full Text Available The article substantiates the necessity to change the role of the state in technological and socio-economic development of the agricultural sector. The author considers the forms and methods of state regulation and analyses the current budget support provided to agriculture; he highlights its drawbacks with regard to sub-arctic and arctic territories of the Republic of Komi. The article shows the influence of state support on the farmers’ level of income and identifies modernization risks and threats under Russia’s WTO membership. The author proposes measures to improve state support of the agrarian sector and change the adverse conditions of its functioning. He substantiates the approach that helps improve the state regulation of the agrarian sector in the framework of regional and municipal programs for rural development

  16. Effects of long-term warming and fertilisation on microarthropod abundances in three sub-arctic ecosystems

    DEFF Research Database (Denmark)

    Sjursen, Heidi; Michelsen, Anders; Jonasson, Sven Evert

    2005-01-01

    Soil microarthropod responses to long-term soil warming and increased fertilisation by addition of NKP or litter were assessed in three subarctic ecosystems. The experiment was carried out at three different field sites, where temperature and fertilisation manipulations had been running for 3...... had higher densities in the treatment with both fertilisation and warming. In the fellfield, we found increased densities of Oribatida, Gamasida and Actinedida in the fertilised treatments, and some increases in Oribatida and decreases in Collembola and Gamasida in warming treatments. In the heath......, there were increased densities of Collembola, Oribatida and Actinedida in the fertilised treatments, but we found no strong effects of warming. We suggest that the responses found in this study comply with the assumption that soil microarthropods are bottom-up controlled, and the observed changes...

  17. Effects of Climate Change on the Freshwaters of Arctic and Subarctic North America

    Science.gov (United States)

    Rouse, Wayne R.; Douglas, Marianne S. V.; Hecky, Robert E.; Hershey, Anne E.; Kling, George W.; Lesack, Lance; Marsh, Philip; McDonald, Michael; Nicholson, Barbara J.; Roulet, Nigel T.; Smol, John P.

    1997-06-01

    Region 2 comprises arctic and subarctic North America and is underlain by continuous or discontinuous permafrost. Its freshwater systems are dominated by a low energy environment and cold region processes. Central northern areas are almost totally influenced by arctic air masses while Pacific air becomes more prominent in the west, Atlantic air in the east and southern air masses at the lower latitudes. Air mass changes will play an important role in precipitation changes associated with climate warming. The snow season in the region is prolonged resulting in long-term storage of water so that the spring flood is often the major hydrological event of the year, even though, annual rainfall usually exceeds annual snowfall. The unique character of ponds and lakes is a result of the long frozen period, which affects nutrient status and gas exchange during the cold season and during thaw. GCM models are in close agreement for this region and predict temperature increases as large as 4°C in summer and 9°C in winter for a 2 × CO2 scenario. Palaeoclimate indicators support the probability that substantial temperature increases have occurred previously during the Holocene. The historical record indicates a temperature increase of > 1°C in parts of the region during the last century. GCM predictions of precipitation change indicate an increase, but there is little agreement amongst the various models on regional disposition or magnitude. Precipitation change is as important as temperature change in determining the water balance. The water balance is critical to every aspect of hydrology and limnology in the far north. Permafrost close to the surface plays a major role in freshwater systems because it often maintains lakes and wetlands above an impermeable frost table, which limits the water storage capabilities of the subsurface. Thawing associated with climate change would, particularly in areas of massive ice, stimulate landscape changes, which can affect every aspect

  18. Mesoscale dynamics in the Lofoten Basin - a sub-Arctic "hot spot" of oceanic variability

    Science.gov (United States)

    Volkov, D. L.; Belonenko, T. V.; Foux, V. R.

    2012-12-01

    A sub-Arctic "hot spot" of intense mesoscale variability is observed in the Lofoten Basin (LB) - a topographic depression with a maximum depth of about 3250 m, located in the Norwegian Sea. The standard deviation of sea surface height (SSH), measured with satellite altimetry, reaches nearly 15 cm in the center of the basin (Figure 1a). Using a space-time lagged correlation analysis of altimetry data, we discover a cyclonic propagation of the mesoscale SSH anomalies around the center of the LB with time-averaged phase speeds of 2-4 km/day, strongly linked to bottom topography (Figure 1c). The fact that surface drifter trajectories do not exhibit cyclonic circulation in the LB (Figure 1b) suggests that, at least in the upper ocean, satellite altimetry observes only the propagation of form without the corresponding transfer of mass. Linearly propagating wavelike disturbances that do not trap fluid inside are related to planetary or Rossby waves. Variations in topography may lead to the concentration of wave energy in certain regions or wave trapping. The dispersion analysis suggests that the observed wavelike cyclonic propagation of SSH anomalies in the LB is the manifestation of baroclinic topographic Rossby waves, that we term "the basin waves" in order to distinguish them from the other types of topographic waves, such as shelf or trench waves. We identify two modes of basin waves in the LB: a di-pole mode and a quadri-pole mode. The wavelength of each mode is about 500 km. The frequency of these modes is not constant and the phase speed varies from about 2 to 8 km/day. We show that the cyclonically rotating basin waves are responsible for the observed amplification of SSH variability in the LB. Because the baroclinic basin waves in the LB are probably associated with large vertical displacements of the thermocline and due to possible wave breaking events, they can play an important role in the mixing of the inflowing Atlantic Water with ambient water masses

  19. Innovative Resources for Education and Public Information: Electronic Services, Data and Information from NASA's Hubble Space Telescope and Other NASA Missions.

    Science.gov (United States)

    Christian, Carol A.

    The Space Telescope Science Institute (STScI), which supports the operation of the Hubble Space Telescope, is actively investigating and supporting innovative and experimental methods for improving science and math education content. The educational resources on the World Wide Web are derived from the latest data, scientific results, and advances…

  20. 大學圖書館電子資源之需求分析與行銷策略之研究 A Study of Demands Analysis and Marketing Strategy of Electronic Resources in University Library

    Directory of Open Access Journals (Sweden)

    Huang-Yu Liu

    2008-03-01

    Full Text Available 電子資源的出現,使得知識載體有了新的突破,提高了使用者的便利性與即時性。對於圖書館而言,如何使電子資源的使用效益達到最高,必須思考一套有效的行銷策略。電子資源行銷概念應以讀者為導向,尊重讀者的資訊需求,並利用各種宣傳技巧,行銷電子資源,使圖書館能提供更完善的服務。本研究之目的旨在探討讀者的使用需求及電子資源的推廣策略,以獲致最有效益的行銷方式。研究對象以開南大學日間部四學院(商學院、運輸觀光學院、資訊學院、人文社會學院)學生為樣本,佐以缺口分析模型為分析架構,藉以找出個案中讀者/學生對於電子資源使用的真實需求,並進而歸納出提供服務的大學圖書館在其推廣或行銷服務上可有的因應策略。The emergence of electronic resources has made new breakthrough in knowledge carriers because of their ease of use, instant availability, and the characteristic of no time and space constraints. For public libraries to achieve maximum efficiency in its electronic resources, it is necessary to seek the most effective marketing strategies. Therefore, the marketing concept of the electronic resources should be reader oriented, such as respecting and understanding library user’s information needs. Libraries also need to utilize various media and techniques to market the electronic resources, so that more comprehensive services and experiences can be provided to readers. The purpose of this study is to investigate library user’s needs and promotion strategies of electronic resources in order to identify the most effective ways of marketing. This study focuses on the students of the four colleges (College of Business, College of Tourism, College of Information, and College of Humanities and Social Science in Kainan University as subjects in the survey questionnaire. It uses the Gap Analysis

  1. Long-term addition of fertilizer, labile carbon, and fungicide alters the biomass of plant functional groups in a subarctic-alpine community

    DEFF Research Database (Denmark)

    Haugwitz-Hardenberg-Reventlow, M S; Michelsen, A.

    2011-01-01

    In subarctic ecosystems, plant growth is mostly limited by nutrient availability and harsh climate. Investigating how soil nutrient availability controls the plant community composition may therefore help to understand indirect effects of climate change. The study was conducted in a long-term field...... experiment on a subarctic-alpine fellfield dominated by woody evergreen shrubs, bryophytes, and lichens. To manipulate nutrient availability additions of NPK fertilizer, labile C, and fungicide (benomyl) were done in a fully factorial design, replicated in six blocks. The treatments were run for 10 years......, and the aboveground plant biomass was harvested 4 and 16 years after initiating the experiment. In addition, soil inorganic N and P concentration was analyzed the same years. Increased nutrient availability (NPK fertilizer) largely increased the biomass of graminoids and unexpectedly of bryophytes, but not of other...

  2. Application of electronic learning tools for training of specialists in the field of information technologies for enterprises of mineral resources sector

    Directory of Open Access Journals (Sweden)

    Е. В. Катунцов

    2017-08-01

    Full Text Available The article shows the advantages of using modern electronic learning tools in the training of specialists for the mineral and raw materials complex and considers the basic principles of organizing training using these tools. The experience of using electronic learning tools using foreign teaching materials and involving foreign professors is described. A special attention is given to the electronic learning environment of the Cisco Networking Academy – Cisco NetAcad. The experience of teaching at the Networking Academy of the Saint-Petersburg Mining University is described. Details are given to modern virtual environments for laboratory work, such as Cisco Packet Tracer, GNS3 and Emulated Virtual Environment. The experience of using electronic learning technologies at the University of Economics of Bratislava is considered. It actively cooperates with a number of universities of other countries, such as the University of International Business (Almaty, the Eurasian National University named after LN Gumilyov (Astana and the Institute of Social and Humanitarian Knowledge (Kazan.

  3. Fiber resources

    Science.gov (United States)

    P. J. Ince

    2004-01-01

    In economics, primary inputs or factors of production define the term ‘resources.’ Resources include land resources (plants, animals, and minerals), labor, capital, and entrepreneurship. Almost all pulp and paper fiber resources are plant materials obtained from trees or agricultural crops. These resources encompass plant materials harvested directly from the land (...

  4. We adapt … but is it good or bad? : Locating the political ecology and social-ecological systems debate in reindeer herding in the Swedish Sub-Arctic

    OpenAIRE

    Gallardo, Gloria; Saunders, Fred; Sokolova, Tatiana; Börebäck, Kristina; Laerhoven, Frank van; Kokko, Suvi; Tuvendal, Magnus

    2017-01-01

    Reindeer herding (RDH) is a livelihood strategy deeply connected to Sami cultural tradition. This article explores the implications of two theoretical and methodological approaches for grasping complex socioenvironmental relationships of RDH in Subarctic Sweden. Based on joint fieldwork, two teams – one that aligns itself with political ecology (PE) and the other with social-ecological systems (SES) – compared PE and SES approaches of understanding RDH. Our purpose was twofold: 1) to describe...

  5. Electronic collection management

    CERN Document Server

    Mcginnis, Suzan D

    2013-01-01

    Build and manage your collection of digital resources with these successful strategies! This comprehensive volume is a practical guide to the art and science of acquiring and organizing electronic resources. The collections discussed here range in size from small college libraries to large research libraries, but all are facing similar problems: shrinking budgets, increasing demands, and rapidly shifting formats. Electronic Collection Management offers new ideas for coping with these issues. Bringing together diverse aspects of collection development, Electronic Collection

  6. Is there a negative impact of winter on mental distress and sleeping problems in the subarctic: The Tromsø Study

    Directory of Open Access Journals (Sweden)

    Johnsen May Trude

    2012-12-01

    Full Text Available Abstract Background Prior studies have suggested that the darkness of winter impacts the level of mental distress and sleeping problems. Our study investigated whether people living in the sub-arctic had more sleeping problems or mental distress during winter. Methods The cross sectional population Tromsø Study was conducted in Tromsø, North Norway, at 69.4 degrees North and above the Arctic Circle. The study included entire birth cohorts and random samples of the population aged 30 to 87 years. Data was collected continuously from 1 October 2007 to the end of December 2008 except July. 8951 persons completed questionnaires including the HSCL-10 and the MCTQ. Results There were no significant differences in the reporting of current mental distress depending on season. Significantly more reported current sleeping problems in winter than in the other seasons, and less sleeping problems was found in spring. Conclusions In this sub-arctic population, insomnia was most prevalent in winter, but there were no significant seasonal differences in mental distress. Although some people in the sub-arctic clearly are mentally negatively affected by the darkness of winter, the negative impact of winter on mental distress for the adult population is not conclusive.

  7. Hepatocyte responses to in vitro freezing and β-adrenergic stimulation: Insights into the extreme freeze tolerance of subarctic Rana sylvatica.

    Science.gov (United States)

    do Amaral, M Clara F; Lee, Richard E; Costanzo, Jon P

    2015-02-01

    The wood frog, Rana sylvatica LeConte 1825, is a freeze-tolerant amphibian widely distributed in North America. Subarctic populations of this species can survive experimental freezing to temperatures below -16 °C, whereas temperate populations tolerate freezing only at temperatures above -6 °C. We investigated whether hepatocytes isolated from frogs indigenous to Interior Alaska (subarctic) or southern Ohio (temperate) had distinct characteristics that could contribute to this variation in freeze tolerance capacity. Following in vitro freezing, cell damage, as assessed from lactate dehydrogenase leakage, was similar between samples from Alaskan and Ohioan frogs. Preincubation of cells in media containing glucose or urea, the two primary cryoprotectants used by R. sylvatica, markedly reduced freezing damage to hepatocytes; however, results suggested that cells of the northern phenotype were comparatively more amenable to cryoprotection by urea. Stimulation of isolated hepatocytes with β-adrenergic agonists, which simulates the freezing-induced cryoprotectant mobilization response, gave rates of glucose production from endogenous glycogen reserves that were similar between the populations. Our findings suggest that extreme freeze tolerance in subarctic R. sylvatica does not require an enhanced ability of the liver to resist freezing stress or rapidly mobilize cryoprotectant. © 2015 Wiley Periodicals, Inc.

  8. Oxygen and silicon stable isotopes of diatom silica. Reconstructing changes in surface water hydrography and silicic acid utilization in the late Pleistocene subarctic Pacific

    Energy Technology Data Exchange (ETDEWEB)

    Maier, Edith

    2014-03-05

    Deglacial variations in upper ocean nutrient dynamics and stratification in high latitudes, as well as associated changes in thermohaline overturning circulation, are thought to have played a key role in changing atmospheric CO{sub 2} concentrations. This thesis examines the relationship between past changes in subarctic Pacific upper ocean stratification and nutrient (silicic acid) utilization, using oxygen and silicon stable isotopes of diatom silica, for the first time at millennial-scale resolution and analyzed with a new and efficient instrumentation set-up. The isotopic data, presented in three manuscripts, show a consistent picture of millennial-scale variability in upper ocean stratification and silicic acid utilization during the last ∝50 ka BP, e.g. indicating that the subarctic Pacific was a source region for atmospheric CO{sub 2} during the last deglaciation (late Heinrich Stadial 1 and the Boelling/Alleroed). The presented results demonstrate the high potential of combined diatom oxygen and silicon stable isotope analysis especially for, but not restricted to, marine regions characterized by a low biogenic carbonate content like the subarctic Pacific and the Southern Ocean.

  9. Positive Perceptions of Access to Online Library Resources Correlates with Quality and Quantity of Scholarly Publications among Finnish Academics. A Review of: Vakkari, Pertti. “Perceived Influence of the Use of Electronic Information Resources on Scholarly Work and Publication Productivity.” Journal of the American Society for Information Science and Technology 59.4 (Feb. 15, 2008: 602-12.

    Directory of Open Access Journals (Sweden)

    Scott Marsalis

    2008-12-01

    Full Text Available Objective – To investigate the relationship between academics’ use of library electronic resources and their opinions regarding how these resources have impacted their work, and to investigate the association between this perceived influence and publication productivity during the previous two years.Design – Two specific questions added to an annual online user-survey questionnaire; additional data mined from surveySetting – Twenty-two Finnish Universities served by FinELib, the Finnish Electronic Library.Subjects – Seven hundred and sixty seven academic staff and full-time doctoral students.Methods – A questionnaire was posted in April 2007 on FinELib’s homepage and advertised on each university library’s mainpage, and focused on respondents’ experience in the previous two years. Participants selected answers either from a list of category choices, or, when measuring perceptions, by rating agreement with statements along a four-point scale. Controlled variables measured were the respondents’ academic position, their discipline, membership in a research group, whether their literature use was discipline-specific or interdisciplinary, and their perception of the availability online of the relevant core literature. The independent variable measured was the scholars’ perception of the impact of the use of electronic library resources on their work. The dependent variable measured was the scholars’ self-reported publications in the two years preceding the survey.Main Results – Participants reported a positive impact on the efficiency of their work, most strongly in areas of ease of access, with lesser impacts in the range of materials available to them and the ease with which they can keep up-to-date in their field. To a lesser extent, the scholars perceived a positive impact on the quality of their work. Upon analysis, the study found that access to online library resources improved scholars’ work by the interconnected

  10. EFFECTIVE ELECTRONIC TUTORIAL

    Directory of Open Access Journals (Sweden)

    Andrei A. Fedoseev

    2014-01-01

    Full Text Available The article analyzes effective electronic tutorials creation and application based on the theory of pedagogy. Herewith the issues of necessary electronic tutorial functional, ways of the educational process organization with the use of information and communication technologies and the logistics of electronic educational resources are touched upon. 

  11. Comparison of snow melt properties across multiple spatial scales and landscape units in interior sub-Arctic boreal Alaskan watersheds

    Science.gov (United States)

    Bennett, K. E.; Cherry, J. E.; Hiemstra, C. A.; Bolton, W. R.

    2013-12-01

    Interior sub-Arctic Alaskan snow cover is rapidly changing and requires further study for correct parameterization in physically based models. This project undertook field studies during the 2013 snow melt season to capture snow depth, snow temperature profiles, and snow cover extent to compare with observations from the Moderate Resolution Imaging Spectroradiometer (MODIS) sensor at four different sites underlain by discontinuous permafrost. The 2013 melt season, which turned out to be the latest snow melt period on record, was monitored using manual field measurements (SWE, snow depth data collection), iButtons to record temperature of the snow pack, GoPro cameras to capture time lapse of the snow melt, and low level orthoimagery collected at ~1500 m using a Navion L17a plane mounted with a Nikon D3s camera. Sites were selected across a range of landscape conditions, including a north facing black spruce hill slope, a south facing birch forest, an open tundra site, and a high alpine meadow. Initial results from the adjacent north and south facing sites indicate a highly sensitive system where snow cover melts over just a few days, illustrating the importance of high resolution temporal data capture at these locations. Field observations, iButtons and GoPro cameras show that the MODIS data captures the melt conditions at the south and the north site with accuracy (2.5% and 6.5% snow cover fraction present on date of melt, respectively), but MODIS data for the north site is less variable around the melt period, owing to open conditions and sparse tree cover. However, due to the rapid melt rate trajectory, shifting the melt date estimate by a day results in a doubling of the snow cover fraction estimate observed by MODIS. This information can assist in approximating uncertainty associated with remote sensing data that is being used to populate hydrologic and snow models (the Sacramento Soil Moisture Accounting model, coupled with SNOW-17, and the Variable

  12. Sorting out non-sorted circles: Effects of winter climate change on the Collembola community of cryoturbated subarctic tundra

    Science.gov (United States)

    Krab, Eveline; Monteux, Sylvain; Becher, Marina; Blume-Werry, Gesche; Keuper, Frida; Klaminder, Jonatan; Kobayashi, Makoto; Lundin, Erik J.; Milbau, Ann; Roennefarth, Jonas; Teuber, Laurenz Michael; Weedon, James; Dorrepaal, Ellen

    2015-04-01

    Non-sorted circles (NSC) are a common type of cryoturbated (frost-disturbed) soil in the arctic and store large amounts of soil organic carbon (SOC) by the burial of organic matter. They appear as sparsely vegetated areas surrounded by denser tundra vegetation, creating patterned ground. Snowfall in the arctic is expected to increase, which will modify freezing intensity and freeze-thaw cycles in soils, thereby impacting on SOC dynamics. Vegetation, soil fauna and microorganisms, important drivers of carbon turnover, may benefit directly from the altered winter conditions and the resulting reduction in cryoturbation, but may also impact each other through trophic cascading. We investigated how Collembola, important decomposer soil fauna in high latitude ecosystems, are affected by increased winter insulation and vegetation cover. We subjected NSC in North-Swedish subarctic alpine tundra to two years of increased thermal insulation (snow fences or fiber cloth) in winter and spring, increasing soil temperatures and strongly reducing freeze-thaw frequency. From these NSC we sampled the Collembola community in: (i) the non-vegetated center, (ii) sparsely vegetated parts in the center and (iii) the vegetated domain surrounding NSC. To link changes in Collembola density and community composition to SOC dynamics, we included measurements of decomposer activity, dissolved organic carbon (DOC) and total extractable nitrogen (TN). We observed differences in Collembola density, community composition and soil fauna activity between the sampling points in the NSC. Specifically Collembola diversity increased with the presence of vegetation and density was higher in the vegetated outer domains. Increased winter insulation did not affect diversity but seemed to negatively affect density and decomposer activity in the vegetated outer domains. Interestingly, SOM distribution over NSC changed with snow addition (also to a lesser extent with fleece insulation) towards less SOM in the

  13. Elemental composition and optical properties reveal changes in dissolved organic matter along a permafrost thaw chronosequence in a subarctic peatland

    Energy Technology Data Exchange (ETDEWEB)

    Hodgkins, Suzanne; Tfaily, Malak M.; Podgorski, David C.; McCalley, Carmody; Saleska, Scott; Crill, Patrick M.; Rich, Virginia; Chanton, Jeffrey; Cooper, William T.

    2016-08-01

    The fate of carbon stored in permafrost-zone peatlands represents a significant uncertainty in global climate modeling. Given that the breakdown of dissolved organic matter (DOM) is often a major pathway for decomposition in peatlands, knowledge of DOM reactivity under different permafrost regimes is critical for determining future climate feedbacks. To explore the effects of permafrost thaw and resultant plant succession on DOM reactivity, we used a combination of Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS), UV/Vis absorbance, and excitation-emission matrix spectroscopy (EEMS) to examine the DOM elemental composition and optical properties of 27 pore water samples gathered from various sites along a permafrost thaw sequence in Stordalen Mire, a thawing subarctic peatland in northern Sweden. The presence of dense Sphagnum moss, a feature that is dominant in the intermediate thaw stages, appeared to be the main driver of variation in DOM elemental composition and optical properties at Stordalen. Specifically, DOM from sites with Sphagnum had greater aromaticity, higher average molecular weights, and greater O/C, consistent with a higher abundance of phenolic compounds that likely inhibit decomposition. These compounds are released by Sphagnum and may accumulate due to inhibition of phenol oxidase activity by the acidic pH at these sites. In contrast, sites without Sphagnum, specifically fully-thawed rich fens, had more saturated, more reduced compounds, which were high in N and S. Optical properties at rich fens were indicated the presence of microbially-derived DOM, consistent with the higher decomposition rates previously measured at these sites. These results indicate that Sphagnum acts as an inhibitor of rapid decomposition and CH4 release in thawing subarctic peatlands, consistent with lower rates of CO2 and CH4 production previously observed at these sites. However, this inhibitory effect may disappear if Sphagnumdominated bogs

  14. Grazing by reindeer in subarctic coniferous forests - how it is affecting three main greenhouse gas emissions from soils.

    Science.gov (United States)

    Köster, Kajar; Köster, Egle; Berninger, Frank; Pumpanen, Jukka

    2017-04-01

    Reindeer (Rangifer tarandus L.) are the most important large mammalian herbivores in the northern ecosystems, strongly affecting Arctic lichen dominated ecosystems. Changes caused by reindeer in vegetation have indirect effects on physical features of the soil e.g. soil microclimate, root biomass and also on soil carbon dynamics, and little is known about reindeer and their impact on greenhouse gas (GHG) emissions between the soil and atmosphere. In a field experiment in northern boreal subarctic coniferous forests in Finnish Lapland, we investigated the influence of reindeer grazing on soil GHG (CO2, CH4 and N2O) fluxes, ground vegetation coverage and biomass, soil temperature and water content. The study was carried out in the growing season of the year 2014. We established the experiment as a split plot experiment with 2 blocks and 5 sub-plots per treatment that were divided into grazed and non-grazed parts, separated with a fence. The sample plots are located along the borderline between Finland and Russia, where the non-grazed area was excluded from reindeer already in 1918, to prevent the Finnish reindeer from going to the Russian side and there are not many reindeer on Russian side of the area. Our study showed that grazing by reindeer significantly affected lichen and moss biomasses. Lichen biomass was significantly lower in the grazed. We also observed that when lichens were removed, mosses were quickly overtaking the areas and moss biomass was significantly higher in grazed areas compared to non-grazed areas. Our results indicated that grazing by reindeer in the northern boreal subarctic forests affects the GHG emissions from the forest floor and these emissions largely depend on changes in vegetation composition. Soil was always a source of CO2in our study, and soil CO2 emissions were significantly smaller in non-grazed areas compared to grazed areas. The soils in our study areas were CH4 sinks through entire measurement period, and grazed areas consumed

  15. Sustainable Agriculture and Climate Change: Producing Potatoes (Solanum tuberosum L. and Bush Beans (Phaseolus vulgaris L. for Improved Food Security and Resilience in a Canadian Subarctic First Nations Community

    Directory of Open Access Journals (Sweden)

    Christine D. Barbeau

    2015-05-01

    Full Text Available Aboriginal people in Canada experience disproportionately high rates of diet-related illnesses, such as obesity and diabetes. Food insecurity has been identified as a contributing factor to these illnesses along with a loss of traditional lifestyle. Current food systems within northern subarctic and arctic regions of Canada rely heavily on imported foods that are expensive (when available, and are environmentally unsustainable. A warming subarctic and arctic climate present challenges, but also offers the opportunity for local agricultural production that can increase food security and promote a more sustainable food system. In this study the feasibility of sustainably growing potatoes (Solanum tuberosum L. utilizing agroforestry practices to enhance food security in remote subarctic communities is explored through a case study in Fort Albany First Nation in northern Ontario, Canada. Potato crops were grown over a two-year period and rotated into plots that had been planted with green bush beans (Phaseolus vulgaris L.. Results showed that potatoes and bush beans could be grown successfully in the subarctic without the use of greenhouses with yields comparable to more conventional high-input agricultural methods. In subarctic Canada, sustainable local food production can help to promote social capital, healthier lifestyles, and food security.

  16. The Fate and Effects of Crude Oil Spilled on Subarctic Permafrost Terrain in Interior Alaska,

    Science.gov (United States)

    1980-12-01

    nalkanes by McCown, B.H., F.J. Deneke, W.E. Rickard and L.L. Tieszen Cladosporium resinae Applied Microbiology, vol 25, p (197 t) The response of...alkanes.on Impact of Oil Resource Deselopment on Northern Plant Com- Cladosporium resinae Canadian Journal of Microbiology. vol munities University of

  17. Merge of terminological resources

    DEFF Research Database (Denmark)

    Henriksen, Lina; Braasch, Anna

    2012-01-01

    – or merging – of terminology resources are strongly needed. This paper discusses prerequisites for successful merging with the focus on identification of candidate duplicates of a subject domain found in the resources to be merged, and it describes automatic merging strategies to be applied to such duplicates...... in electronic terminology resources. Further, some perspectives of manual, supplementary assessment methods supporting the automatic procedures are sketched. Our considerations are primarily based on experience gained in the IATE and EuroTermBank projects, as merging was a much discussed issue in both projects....

  18. Renewable energy resources

    DEFF Research Database (Denmark)

    Ellabban, Omar S.; Abu-Rub, Haitham A.; Blaabjerg, Frede

    2014-01-01

    Electric energy security is essential, yet the high cost and limited sources of fossil fuels, in addition to the need to reduce greenhouse gasses emission, have made renewable resources attractive in world energy-based economies. The potential for renewable energy resources is enormous because...... they can, in principle, exponentially exceed the world's energy demand; therefore, these types of resources will have a significant share in the future global energy portfolio, much of which is now concentrating on advancing their pool of renewable energy resources. Accordingly, this paper presents how...... renewable energy resources are currently being used, scientific developments to improve their use, their future prospects, and their deployment. Additionally, the paper represents the impact of power electronics and smart grid technologies that can enable the proportionate share of renewable energy...

  19. Community- and population-level changes in diatom size structure in a subarctic lake over the last two centuries

    Directory of Open Access Journals (Sweden)

    Elizabeth A. Kerrigan

    2015-07-01

    Full Text Available Climate change over the last two centuries has been associated with significant shifts in diatom community structure in lakes from the high arctic to temperate latitudes. To test the hypotheses that recent climate warming selects for species of smaller size within communities and a decrease in the average size of species within populations, we quantified the size of individual diatom valves from 10 depths in a sediment core covering the last ∼200 years from a pristine subarctic lake. Over the last ∼200 years, changes in the relative abundance of species of different average size and changes in the average valve size of populations of species contribute equally to the changes in community size structure, but are often opposite in sign, compensating for one another and moderating temporal changes in community size structure. In the surface sediments that correspond to the recent decades when air temperatures have warmed, the mean size of valves in the diatom community has significantly decreased due to an increase in the proportion of smaller-sized planktonic diatom species.

  20. High Methylmercury in Arctic and Subarctic Ponds is Related to Nutrient Levels in the Warming Eastern Canadian Arctic.

    Science.gov (United States)

    MacMillan, Gwyneth A; Girard, Catherine; Chételat, John; Laurion, Isabelle; Amyot, Marc

    2015-07-07

    Permafrost thaw ponds are ubiquitous in the eastern Canadian Arctic, yet little information exists on their potential as sources of methylmercury (MeHg) to freshwaters. They are microbially active and conducive to methylation of inorganic mercury, and are also affected by Arctic warming. This multiyear study investigated thaw ponds in a discontinuous permafrost region in the Subarctic taiga (Kuujjuarapik-Whapmagoostui, QC) and a continuous permafrost region in the Arctic tundra (Bylot Island, NU). MeHg concentrations in thaw ponds were well above levels measured in most freshwater ecosystems in the Canadian Arctic (>0.1 ng L(-1)). On Bylot, ice-wedge trough ponds showed significantly higher MeHg (0.3-2.2 ng L(-1)) than polygonal ponds (0.1-0.3 ng L(-1)) or lakes (ponds near Kuujjuarapik (0.1-3.1 ng L(-1)). High water MeHg concentrations in thaw ponds were strongly correlated with variables associated with high inputs of organic matter (DOC, a320, Fe), nutrients (TP, TN), and microbial activity (dissolved CO2 and CH4). Thawing permafrost due to Arctic warming will continue to release nutrients and organic carbon into these systems and increase ponding in some regions, likely stimulating higher water concentrations of MeHg. Greater hydrological connectivity from permafrost thawing may potentially increase transport of MeHg from thaw ponds to neighboring aquatic ecosystems.

  1. Trends in Ostracoda and Cladocera distribution and water chemistry in subarctic Canada: Churchill (Manitoba lakes and ponds revisited

    Directory of Open Access Journals (Sweden)

    Finn A. Viehberg

    2017-03-01

    Full Text Available Ponds and lakes distributed across northern treeline in the Hudson Bay Lowlands near Churchill (Manitoba were revisited to analyse and document the local ecoclimatic and limnological changes that occurred over the period 1997-2012. Our analyses revealed that single events may cause significant changes in salinity, pH and silicate content because of the limited buffer capacity of the inter-connected waters. Planktic freshwater microcrustaceans (Cladocera presented less diverse assemblages and appeared to favour waters that are situated in the boreal forest, while the diversity of benthic species assemblages (Cladocera and Ostracoda was highest in waters located closer to the coastline and in open tundra vegetation. We identified three species that are distinctive for the boreal ecozone (i.e., Candona acuta, Can. acutula and Can. decora and two species (i.e., Tonnacypris glacialis and Can. rawsoni that are elements of (sub-arctic landscapes and potentially endangered as the northern treeline expands due to rapid warming. These species are thought to be useful indicators for future ecosystem quality assessments and/or ecosystem service management programs. Our findings were compared to other studies completed in the boreal Yukon Territory and revealed that species diversity is closely linked to landscape history.

  2. Dynamic controls on the subarctic North Pacific productivity peak during the Bølling-Allerød

    Science.gov (United States)

    Gong, Xun; Lembke-Jene, Lester; Tiedemann, Ralf; Lohmann, Gerrit

    2016-04-01

    Prominent maxima of biological productivity are recorded in both the Northwest and Northeast Pacific during the deglacial, interstadial Bølling-Allerød. These have been linked to a suite of differing causes and mechanisms, such as preservation effects, iron fertilization, riverine fluxes, upper ocean stratification and coastal upwelling. There is also widespread evidence for shifts in the subarctic Pacific ocean circulation during the deglaciation. However, while the dynamics of nutrient provision and limitation within the photic zone are certainly of high significance, the important role of physical circulation changes in the subsurface to deep ocean in replenishing nutrient supplies to the upper ocean, and of upper ocean temperature changes in fostering productivity peaks, remain largely unconstrained over the course of the last deglaciation. Here, using an Earth System Model COSMOS, we conducted a simulation representing the climate transition from the Last Glacial Maximum to the Bølling-Allerød. In association with marine proxy evidence, we will discuss the deglacial evolution of the surface to deep ocean circulation and mixing in the North Pacific, and examine their respective roles in determining the upwelling of nutrients from deeper layers, along with the formation of the North Pacific Intermediate water.

  3. Barcoding the Collembola of Churchill: a molecular taxonomic reassessment of species diversity in a sub-Arctic area.

    Science.gov (United States)

    Porco, David; Skarżyński, Dariusz; Decaëns, Thibaud; Hebert, Paul D N; Deharveng, Louis

    2014-03-01

    Although their functional importance in ecosystems is increasingly recognized, soil-dwelling micro-arthropods are usually poorly known in comparison with their above-ground counterparts. Collembola constitute a significant and species-rich component of the soil biodiversity, but it remains a woefully understudied group because of the taxonomic impediment. The ever-increasing use of molecular taxonomic tools, such as DNA barcoding, provides a possible solution. Here, we test the use of this approach through a diversity survey of Collembola from the vicinity of Churchill, Manitoba, Canada, and compare the results with previous surveys in the same area and in other sub-Arctic regions. The systematic barcoding campaign at Churchill revealed a diverse collembolan fauna consisting of 97 species-level MOTUs in six types of habitats. If all these MOTUs are confirmed as species, this richness would be far higher than prior records for Arctic Canada and could lead to reconsider the actual diversity of the group in Arctic environments. © 2013 John Wiley & Sons Ltd.

  4. Environmental factors influencing soil testate amoebae in herbaceous and shrubby vegetation along an altitudinal gradient in subarctic tundra (Abisko, Sweden).

    Science.gov (United States)

    Tsyganov, Andrey N; Milbau, Ann; Beyens, Louis

    2013-05-01

    Shifts in community composition of soil protozoa in response to climate change may substantially influence microbial activity and thereby decomposition processes. However, effects of climate and vegetation on soil protozoa remain poorly understood. We studied the distribution of soil testate amoebae in herbaceous and shrubby vegetation along an altitudinal gradient (from below the treeline at 500 m to the mid-alpine region at 900 m a.s.l.) in subarctic tundra. To explain patterns in abundance, species diversity and assemblage composition of testate amoebae, a data set of microclimate and soil chemical characteristics was collected. Both elevation and vegetation influenced the assemblage composition of testate amoebae. The variation was regulated by interactive effects of summer soil moisture, winter soil temperature, soil pH and nitrate ion concentrations. Besides, soil moisture regulated non-linear patterns in species richness across the gradient. This is the first study showing the effects of winter soil temperatures on species composition of soil protozoa. The effects could be explained by specific adaptations of testate amoebae such as frost-resistant cysts allowing them to survive low winter temperatures. We conclude that the microclimate and soil chemical characteristics are the main drivers of changes in protozoan assemblage composition in response to elevation and vegetation. Copyright © 2012 Elsevier GmbH. All rights reserved.

  5. Topsoil pollution forecasting using artificial neural networks on the example of the abnormally distributed heavy metal at Russian subarctic

    Science.gov (United States)

    Tarasov, D. A.; Buevich, A. G.; Sergeev, A. P.; Shichkin, A. V.; Baglaeva, E. M.

    2017-06-01

    Forecasting the soil pollution is a considerable field of study in the light of the general concern of environmental protection issues. Due to the variation of content and spatial heterogeneity of pollutants distribution at urban areas, the conventional spatial interpolation models implemented in many GIS packages mostly cannot provide appreciate interpolation accuracy. Moreover, the problem of prediction the distribution of the element with high variability in the concentration at the study site is particularly difficult. The work presents two neural networks models forecasting a spatial content of the abnormally distributed soil pollutant (Cr) at a particular location of the subarctic Novy Urengoy, Russia. A method of generalized regression neural network (GRNN) was compared to a common multilayer perceptron (MLP) model. The proposed techniques have been built, implemented and tested using ArcGIS and MATLAB. To verify the models performances, 150 scattered input data points (pollutant concentrations) have been selected from 8.5 km2 area and then split into independent training data set (105 points) and validation data set (45 points). The training data set was generated for the interpolation using ordinary kriging while the validation data set was used to test their accuracies. The networks structures have been chosen during a computer simulation based on the minimization of the RMSE. The predictive accuracy of both models was confirmed to be significantly higher than those achieved by the geostatistical approach (kriging). It is shown that MLP could achieve better accuracy than both kriging and even GRNN for interpolating surfaces.

  6. Effects of reindeer on the re-establishment of Betula pubescens subsp. czerepanovii and Salix phylicifolia in a subarctic meadow

    Directory of Open Access Journals (Sweden)

    Michael den Herder

    2003-04-01

    Full Text Available The effect of reindeer browsing on the regeneration of Betula pubescens subsp. czerepanovii and Salix phylicifolia was studied in a subarctic meadow in Finnish Lapland. The aim of the study was to see whether tree recovery from seeds is possible under heavy reindeer-browsing pressure. After removal of the ground and field layer vegetation in 1986, two exclosures were established so that the effect of reindeer on the secondary succession, starting from seeds, could be studied. The size and the number of B. pubescens and S. phylicifolia were recorded in 1994, 1996, 1997 and 1999. Reindeer significantly reduced the height and the number of saplings (plants > 10 cm high of B. pubescens and S. phylicifolia but the number of seedlings (plants < 10 cm high did not differ between browsed and unbrowsed plots. Furthermore the heightclass distribution of saplings was different inside the exlosures compared to control areas. Over time browsed plots continued to have high densities of small saplings while in protected plots an increasing number of larger saplings appeared. In our study site, regeneration from seeds seemed possible although the height of B. pubescens and S. phylicifolia was limited by reindeer. 

  7. Replacement cost valuation of Northern Pintail (Anas acuta) subsistence harvest in Arctic and sub-Arctic North America

    Science.gov (United States)

    Goldstein, Joshua H.; Thogmartin, Wayne E.; Bagstad, Kenneth J.; Dubovsky, James A.; Mattsson, Brady J.; Semmens, Darius J.; López-Hoffman, Laura; Diffendorfer, James E.

    2014-01-01

    Migratory species provide economically beneficial ecosystem services to people throughout their range, yet often, information is lacking about the magnitude and spatial distribution of these benefits at regional scales. We conducted a case study for Northern Pintails (hereafter pintail) in which we quantified regional and sub-regional economic values of subsistence harvest to indigenous communities in Arctic and sub-Arctic North America. As a first step, we used the replacement cost method to quantify the cost of replacing pintail subsistence harvest with the most similar commercially available protein (chicken). For an estimated annual subsistence harvest of ˜15,000 pintail, our mean estimate of the total replacement cost was ˜$63,000 yr−1 ($2010 USD), with sub-regional values ranging from \\$263 yr−1 to \\$21,930 yr−1. Our results provide an order-of-magnitude, conservative estimate of one component of the regional ecosystem-service values of pintails, providing perspective on how spatially explicit values can inform migratory species conservation.

  8. Study of time-lapse processing for dynamic hydrologic conditions. [electronic satellite image analysis console for Earth Resources Technology Satellites imagery

    Science.gov (United States)

    Serebreny, S. M.; Evans, W. E.; Wiegman, E. J.

    1974-01-01

    The usefulness of dynamic display techniques in exploiting the repetitive nature of ERTS imagery was investigated. A specially designed Electronic Satellite Image Analysis Console (ESIAC) was developed and employed to process data for seven ERTS principal investigators studying dynamic hydrological conditions for diverse applications. These applications include measurement of snowfield extent and sediment plumes from estuary discharge, Playa Lake inventory, and monitoring of phreatophyte and other vegetation changes. The ESIAC provides facilities for storing registered image sequences in a magnetic video disc memory for subsequent recall, enhancement, and animated display in monochrome or color. The most unique feature of the system is the capability to time lapse the imagery and analytic displays of the imagery. Data products included quantitative measurements of distances and areas, binary thematic maps based on monospectral or multispectral decisions, radiance profiles, and movie loops. Applications of animation for uses other than creating time-lapse sequences are identified. Input to the ESIAC can be either digital or via photographic transparencies.

  9. Electronics and electronic systems

    CERN Document Server

    Olsen, George H

    1987-01-01

    Electronics and Electronic Systems explores the significant developments in the field of electronics and electronic devices. This book is organized into three parts encompassing 11 chapters that discuss the fundamental circuit theory and the principles of analog and digital electronics. This book deals first with the passive components of electronic systems, such as resistors, capacitors, and inductors. These topics are followed by a discussion on the analysis of electronic circuits, which involves three ways, namely, the actual circuit, graphical techniques, and rule of thumb. The remaining p

  10. Summer (subarctic) versus winter (subtropic) production affects spinach (Spinacia oleracea L.) leaf bionutrients: vitamins (C, E, Folate, K1, provitamin A), lutein, phenolics, and antioxidants.

    Science.gov (United States)

    Lester, Gene E; Makus, Donald J; Hodges, D Mark; Jifon, John L

    2013-07-24

    Comparison of spinach (Spinacia oleracea L.) cultivars Lazio and Samish grown during the summer solstice in the subarctic versus the winter solstice in the subtropics provided insight into interactions between production environment (light intensity), cultivar, and leaf age/maturity/position affecting bionutrient concentrations of vitamins (C, E, folate, K1, provitamin A), lutein, phenolics, and antioxidants. Growing spinach during the winter solstice in the subtropics resulted in increased leaf dry matter %, oxidized (dehydro) ascorbic acid (AsA), α- and γ-tocopherol, and total phenols but lower reduced (free) AsA, α-carotene, folate, and antioxidant capacity compared to summer solstice-grown spinach in the subarctic. Both cultivars had similar bionutrients, except for higher dehydroAsA, and lower α- and γ-tocopherol in 'Samish' compared to 'Lazio'. For most bionutrients measured, there was a linear, and sometimes quadratic, increase in concentrations from bottom to top canopy leaves. However, total phenolics and antioxidant capacity increased basipetally. The current study has thus demonstrated that dehydroAsA, α-tocopherol, and γ-tocopherol were substantially lower in subarctic compared to subtropical-grown spinach, whereas the opposite relationship was found for antioxidant capacity, α-carotene, and folates (vitamin B9). The observations are consistent with previously reported isolated effects of growth environment on bionutrient status of crops. The current results clearly highlight the effect of production environment (predominantly radiation capture), interacting with genetics and plant phenology to alter the bionutrient status of crops. While reflecting the effects of changing growing conditions, these results also indicate potential alterations in the nutritive value of foods with anticipated shifts in global climatic conditions.

  11. Climatic and biotic extreme events moderate long-term responses of above- and belowground sub-Arctic heathland communities to climate change.

    Science.gov (United States)

    Bokhorst, Stef; Phoenix, Gareth K; Berg, Matty P; Callaghan, Terry V; Kirby-Lambert, Christopher; Bjerke, Jarle W

    2015-11-01

    Climate change impacts are not uniform across the Arctic region because interacting factors causes large variations in local ecosystem change. Extreme climatic events and population cycles of herbivores occur simultaneously against a background of gradual climate warming trends and can redirect ecosystem change along routes that are difficult to predict. Here, we present the results from sub-Arctic heath vegetation and its belowground micro-arthropod community in response to the two main drivers of vegetation damage in this region: extreme winter warming events and subsequent outbreaks of the defoliating autumnal moth caterpillar (Epirrita autumnata). Evergreen dwarf shrub biomass decreased (30%) following extreme winter warming events and again by moth caterpillar grazing. Deciduous shrubs that were previously exposed to an extreme winter warming event were not affected by the moth caterpillar grazing, while those that were not exposed to warming events (control plots) showed reduced (23%) biomass from grazing. Cryptogam cover increased irrespective of grazing or winter warming events. Micro-arthropods declined (46%) following winter warming but did not respond to changes in plant community. Extreme winter warming and caterpillar grazing suppressed the CO2 fluxes of the ecosystem. Evergreen dwarf shrubs are disadvantaged in a future sub-Arctic with more stochastic climatic and biotic events. Given that summer warming may further benefit deciduous over evergreen shrubs, event and trend climate change may both act against evergreen shrubs and the ecosystem functions they provide. This is of particular concern given that Arctic heath vegetation is typically dominated by evergreen shrubs. Other components of the vegetation showed variable responses to abiotic and biotic events, and their interaction indicates that sub-Arctic vegetation response to multiple pressures is not easy to predict from single-factor responses. Therefore, while biotic and climatic events may

  12. What determines the current presence or absence of permafrost in the Torneträsk region, a sub-arctic landscape in northern Sweden?

    Science.gov (United States)

    Johansson, Margareta; Christensen, Torben R; Akerman, H Jonas; Callaghan, Terry V

    2006-06-01

    In a warming climate, permafrost is likely to be significantly reduced and eventually disappear from the sub-Arctic region. This will affect people at a range of scales, from locally by slumping of buildings and roads, to globally as melting of permafrost will most likely increase the emissions of the powerful greenhouse gas methane, which will further enhance global warming. In order to predict future changes in permafrost, it is crucial to understand what determines the presence or absence of permafrost under current climate conditions, to assess where permafrost is particularly vulnerable to climate change, and to identify where changes are already occurring. The Torneträsk region of northern sub-Arctic Sweden is one area where changes in permafrost have been recorded and where permafrost could be particularly vulnerable to any future climate changes. This paper therefore reviews the various physical, biological, and anthropogenic parameters that determine the presence or absence of permafrost in the Torneträsk region under current climate conditions, so that we can gain an understanding of its current vulnerability and potential future responses to climate change. A patchy permafrost distribution as found in the Torneträsk region is not random, but a consequence of site-specific factors that control the microclimate and hence the surface and subsurface temperature. It is also a product of past as well as current processes. In sub-Arctic areas such as northern Sweden, it is mainly the physical parameters, e.g., topography, soil type, and climate (in particular snow depth), that determine permafrost distribution. Even though humans have been present in the study area for centuries, their impacts on permafrost distribution can more or less be neglected at the catchment level. Because ongoing climate warming is projected to continue and lead to an increased snow cover, the permafrost in the region will most likely disappear within decades, at least at lower

  13. Relative importance of plant uptake and plant associated denitrification for removal of nitrogen from mine drainage in sub-arctic wetlands.

    Science.gov (United States)

    Hallin, Sara; Hellman, Maria; Choudhury, Maidul I; Ecke, Frauke

    2015-11-15

    Reactive nitrogen (N) species released from undetonated ammonium-nitrate based explosives used in mining or other blasting operations are an emerging environmental problem. Wetlands are frequently used to treat N-contaminated water in temperate climate, but knowledge on plant-microbial interactions and treatment potential in sub-arctic wetlands is limited. Here, we compare the relative importance of plant uptake and denitrification among five plant species commonly occurring in sub-arctic wetlands for removal of N in nitrate-rich mine drainage in northern Sweden. Nitrogen uptake and plant associated potential denitrification activity and genetic potential for denitrification based on quantitative PCR of the denitrification genes nirS, nirK, nosZI and nosZII were determined in plants growing both in situ and cultivated in a growth chamber. The growth chamber and in situ studies generated similar results, suggesting high relevance and applicability of results from growth chamber experiments. We identified denitrification as the dominating pathway for N-removal and abundances of denitrification genes were strong indicators of plant associated denitrification activity. The magnitude and direction of the effect differed among the plant species, with the aquatic moss Drepanocladus fluitans showing exceptionally high ratios between denitrification and uptake rates, compared to the other species. However, to acquire realistic estimates of N-removal potential of specific wetlands and their associated plant species, the total plant biomass needs to be considered. The species-specific plant N-uptake and abundance of denitrification genes on the root or plant surfaces were affected by the presence of other plant species, which show that both multi- and inter-trophic interactions are occurring. Future studies on N-removal potential of wetland plant species should consider how to best exploit these interactions in sub-arctic wetlands. Copyright © 2015 Elsevier Ltd. All rights

  14. Importance of Ekman transport and gyre circulation change on seasonal variation of surface dissolved iron in the western subarctic North Pacific

    Science.gov (United States)

    Nakanowatari, Takuya; Nakamura, Tomohiro; Uchimoto, Keisuke; Nishioka, Jun; Mitsudera, Humio; Wakatsuchi, Masaaki

    2017-05-01

    Iron (Fe) is an essential nutrient for marine phytoplankton and it constitutes an important element in the marine carbon cycle in the ocean. This study examined the mechanisms controlling seasonal variation of dissolved Fe (dFe) in the western subarctic North Pacific (WSNP), using an ocean general circulation model coupled with a simple biogeochemical model incorporating a dFe cycle fed by two major sources (atmospheric dust and continental shelf sediment). The model reproduced the seasonal cycle of observed concentrations of dFe and macronutrients at the surface in the Oyashio region with maxima in winter (February-March) and minima in summer (July-September), although the simulated seasonal amplitudes are a half of the observed values. Analysis of the mixed-layer dFe budget indicated that both local vertical entrainment and lateral advection are primary contributors to the wintertime increase in dFe concentration. In early winter, strengthened northwesterly winds excite southward Ekman transport and Ekman upwelling over the western subarctic gyre, transporting dFe-rich water southward. In mid to late winter, the southward western boundary current of the subarctic gyre and the outflow from the Sea of Okhotsk also bring dFe-rich water to the Oyashio region. The contribution of atmospheric dust to the dFe budget is several times smaller than these ocean transport processes in winter. These results suggest that the westerly wind-induced Ekman transport and gyre circulation systematically influence the seasonal cycle of WSNP surface dFe concentration.

  15. Long-term warming of a subarctic heath decreases soil bacterial community growth but has no effects on its temperature adaptation

    DEFF Research Database (Denmark)

    Rinnan, Riikka; Michelsen, Anders; Bååth, E

    2011-01-01

    We tested whether bacterial communities of subarctic heath soil are adapted to elevated temperature after experimental warming by open-top greenhouses for 7 or 17 years. The long-term warming by 1–2 °C significantly decreased bacterial community growth, by 28% and 73% after 7 and 17 years......, respectively. The decrease was most likely due to decreased availability of labile substrate under warming. However, we found no evidence for temperature adaptation of soil bacterial communities. The optimum temperature for bacterial growth was on average 25 °C, and the apparent minimum temperature for growth...

  16. Iron availability, nitrate uptake, and exportable new production in the subarctic Pacific. [phytoplankton population growth support and atmospheric CO2 removal

    Science.gov (United States)

    Banse, Karl

    1991-01-01

    This paper presents a critique of experimental data and papers by Martin et al. (1989, 1990), who suggested that the phytoplankton growth is iron-limited and that, small additions of iron to large subarctic ocean areas might be a way of removing significant amounts of atmospheric CO2 by increasing phytoplancton growth. Data are presented to show that, in the summer of 1987, the phytoplankton assemblage as a whole was not iron limited, as measured by the bulk removal of nitrate or by the increase of chlorophyll. It is suggested that grazing normally prevents the phytoplankton from reaching concentrations that reduce the iron (and nitrate) to levels that depress division rates drastically.

  17. The downward flux of biogenic material in the NE subarctic Pacific: importance of algal sinking and mesozooplankton herbivory

    Science.gov (United States)

    Thibault, D.; Roy, S.; Wong, C. S.; Bishop, J. K.

    1999-11-01

    In the present study we examine factors that affect the downward flux of biogenic carbon in the NE subarctic Pacific, one of the important high-nutrient-low-chlorophyll (HNLC) regions in the open ocean. We focus on the role of mesozooplankton, since their seasonal peaks in biomass and growth are in phase with the seasonal variations in the downward POC fluxes, whereas phytoplankton biomass is more-or-less uniform year-round. The relative importance of mesozooplankton and algal sinking was examined using the pigment composition of material accumulated in short-term free-drifting sediment traps positioned just below the upper stratified surface layer (ca. 100-200 m). This was compared with the phytoplankton composition in the surface waters, and with the grazing activity (gut pigments and fecal pellet production rates) of the most abundant large copepods. We also examined whether the relationships between the downward flux of carbon and pelagic processes were similar in the coastal, continental margin and offshore HNLC regions of the NE subarctic Pacific, the latter represented by Ocean Station Papa (OSP). Our results show that grazing had a variable impact on the downward flux of biogenic carbon. Carbon-transformed pheopigments (particularly pyropheophorbide a, frequently associated with copepod grazing) represented up to 13% of the total downward POC flux inshore (in May 1996) and 8-9% at OSP in May and February 1996, respectively. This flux of pheopigments was accompanied by a large potential input of fecal pellets from large copepods (as estimated from defecation rates of freshly collected animals) only in May 1996 at OSP, suggesting that pheopigments came from other sources (other herbivores, senescing algae) in February. The larger flux of pheopigments in May was probably related to the abundance of mesozooplankton at that time of the year. During summer (August 1996), both the flux of pheopigments and the potential input of fecal pellets from large copepods

  18. Foliar Expression of Parent Lithologic Composition in the Sub-Arctic: Examples from Heath Ecosystems of Abisko, Sweden.

    Science.gov (United States)

    Heim, E. W.; Tomczyk, N.; Remiszewski, K.; Bryce, J. G.; Frey, S. D.; Prado, M. F.; Varner, R. K.

    2014-12-01

    Climatic evolution and its effect on ecosystem stability through macronutrient acquisition is of particular interest in the fringe ecosystems of the Arctic and Sub-Arctic, regions predicted to face the most extreme temperature increases in Earth's changing climate. Accordingly enhanced understanding of climate change impacts on nutrient mobilization in recently glaciated terrains will factor importantly into accurate predictive models for future ecosystem health. Lithologic variation can lead to differences in geomorphic processes and thus influence landscape evolution [1]. Heath ecosystems in the region are developed on thin soils which place them close to parent material bedrock. Given the abundance of thin soils mantling bedrock, we assessed how bedrock geochemical content links with foliar composition of key macronutrients. We focused our studies on four sites near Abisko, Sweden (68°21'N 19°02'E) in metamorphosed sedimentary bedrock. In our sites the average annual air temperature has crossed the 0o threshold and has been linked to many cryospheric and ecological impacts [2]. Sites were chosen at the same elevation (700 m absl) and shared similar vegetation coverage. Three dominant species across our sampling sites include Betula nana, Empetrum nigrum, and Salix lapponum. E. Nigrum had consistent concentrations of foliar magnesium (Mg) and phosphorus (P) across the bedrock compositional gradients. B. nana and S. lapponum had consistently higher foliar Mg and P concentrations than E. nigrum across the gradients. Across a soil calcium (Ca) gradient, dominant species had a weak correlation between soil Ca and foliar Ca contents, R2 = 0.106. Soil Mg and P gradients were similarly poorly correlated with foliar abundances, R2 = -0.0228, and R2= -0.034 respectively. Expansion of our work into other lithologies will contribute towards improved predictive biogeochemical models of macronutrient acquisition and ecological evolution across changing Arctic ecosystems.

  19. Animistic pragmatism and native ways of knowing: adaptive strategies for overcoming the struggle for food in the sub-Arctic

    Directory of Open Access Journals (Sweden)

    Raymond Anthony

    2013-08-01

    Full Text Available Background. Subsistence norms are part of the “ecosophy” or ecological philosophy of Alaska Native Peoples in the sub-Arctic, such as the Inupiat of Seward Peninsula. This kind of animistic pragmatism is a special source of practical wisdom that spans over thousands of years and which has been instrumental in the Iñupiat’s struggle to survive and thrive in harsh and evolving environments. Objective. I hope to show how narrative in relationship to the “ecosophy” of Alaska Native peoples can help to promote a more ecological orientation to address food insecurity in rural communities in Alaska. Alaska Native ecosophy recommends central values and virtues necessary to help address concerns in Alaska’s rural communities. Design. Here, I will tease out the nature of this “ecosophy” in terms of animistic pragmatism and then show why this form of pragmatism can be instrumental for problematizing multi-scalar, intergenerational, uncertain and complex environmental challenges like food security. Results. Native elders have been the embodiment of trans-generational distributed cognition,1 for example, collective memory, norms, information, knowledge, technical skills and experimental adaptive strategies. They are human “supercomputers,” historical epistemologists and moral philosophers of a sort who use narrative, a form of moral testimony, to help their communities face challenges and seize opportunities in the wake of an ever-changing landscape. Conclusions. The “ecosophy” of the Iñupiat of Seward Peninsula offers examples of “focal practices”, which are essential for environmental education. These focal practices instil key virtues, namely humility, gratitude, self-reliance, attentiveness, responsibility and responsiveness, that are necessary for subsistence living.

  20. Impacts of winter icing events on the growth, phenology and physiology of sub-arctic dwarf shrubs.

    Science.gov (United States)

    Preece, Catherine; Callaghan, Terry V; Phoenix, Gareth K

    2012-12-01

    The Arctic is experiencing the greatest climate change in winter, including increases in freeze-thaw cycles that can result in ice encasement of vegetation. Ice encasement can expose plants to hypoxia and greater temperature extremes, but currently the impacts of icing on plants in the field remain little understood. With this in mind, a unique field manipulation experiment was established in heathland in northern Sweden with ice encasement simulated in early March 2008, 2009 and 2010 until natural thaw each spring. In the following summers we assessed the impacts on flowering, bud phenology, shoot growth and mortality and leaf damage (measured by chlorophyll fluorescence and electrolyte leakage) of the three dominant dwarf shrub species Empetrum nigrum, Vaccinium vitis-idaea (both evergreen) and Vaccinium myrtillus (deciduous). Two consecutive winters of icing decreased V. vitis-idaea flowering by 57%, while flowering of V. myrtillus and E. nigrum remained unaffected. Vaccinium myrtillus showed earlier budburst but shoot growth for all species was unchanged. Shoot mortality of V. myrtillus and V. vitis-idaea increased after the first year (by 70 and 165%, respectively) and again for V. myrtillus following the third year (by 67%), while E. nigrum shoot mortality remained unaffected, as were chlorophyll fluorescence and electrolyte leakage in all species. Overall, the sub-arctic heathland was relatively tolerant to icing, but the considerable shoot mortality of V. myrtillus contrasting with the general tolerance of E. nigrum suggests plant community structure in the longer term could change if winters continue to see a greater frequency of icing events. Copyright © Physiologia Plantarum 2012.

  1. Rapid carbon turnover beneath shrub and tree vegetation is associated with low soil carbon stocks at a subarctic treeline.

    Science.gov (United States)

    Parker, Thomas C; Subke, Jens-Arne; Wookey, Philip A

    2015-05-01

    Climate warming at high northern latitudes has caused substantial increases in plant productivity of tundra vegetation and an expansion of the range of deciduous shrub species. However significant the increase in carbon (C) contained within above-ground shrub biomass, it is modest in comparison with the amount of C stored in the soil in tundra ecosystems. Here, we use a 'space-for-time' approach to test the hypothesis that a shift from lower-productivity tundra heath to higher-productivity deciduous shrub vegetation in the sub-Arctic may lead to a loss of soil C that out-weighs the increase in above-ground shrub biomass. We further hypothesize that a shift from ericoid to ectomycorrhizal systems coincident with this vegetation change provides a mechanism for the loss of soil C. We sampled soil C stocks, soil surface CO2 flux rates and fungal growth rates along replicated natural transitions from birch forest (Betula pubescens), through deciduous shrub tundra (Betula nana) to tundra heaths (Empetrum nigrum) near Abisko, Swedish Lapland. We demonstrate that organic horizon soil organic C (SOCorg ) is significantly lower at shrub (2.98 ± 0.48 kg m(-2) ) and forest (2.04 ± 0.25 kg m(-2) ) plots than at heath plots (7.03 ± 0.79 kg m(-2) ). Shrub vegetation had the highest respiration rates, suggesting that despite higher rates of C assimilation, C turnover was also very high and less C is sequestered in the ecosystem. Growth rates of fungal hyphae increased across the transition from heath to shrub, suggesting that the action of ectomycorrhizal symbionts in the scavenging of organically bound nutrients is an important pathway by which soil C is made available to microbial degradation. The expansion of deciduous shrubs onto potentially vulnerable arctic soils with large stores of C could therefore represent a significant positive feedback to the climate system. © 2014 John Wiley & Sons Ltd.

  2. Seasonal variations in methane fluxes in response to summer warming and leaf litter addition in a subarctic heath ecosystem

    Science.gov (United States)

    Pedersen, Emily Pickering; Elberling, Bo; Michelsen, Anders

    2017-08-01

    Methane (CH4) is a powerful greenhouse gas controlled by both biotic and abiotic processes. Few studies have investigated CH4 fluxes in subarctic heath ecosystems, and climate change-induced shifts in CH4 flux and the overall carbon budget are therefore largely unknown. Hence, there is an urgent need for long-term in situ experiments allowing for the study of ecosystem processes over time scales relevant to environmental change. Here we present in situ CH4 and CO2 flux measurements from a wet heath ecosystem in northern Sweden subjected to 16 years of manipulations, including summer warming with open-top chambers, birch leaf litter addition, and the combination thereof. Throughout the snow-free season, the ecosystem was a net sink of CH4 and CO2 (CH4 -0.27 mg C m-2 d-1; net ecosystem exchange -1827 mg C m-2 d-1), with highest CH4 uptake rates (-0.70 mg C m-2 d-1) during fall. Warming enhanced net CO2 flux, while net CH4 flux was governed by soil moisture. Litter addition and the combination with warming significantly increased CH4 uptake rates, explained by a pronounced soil drying effect of up to 32% relative to ambient conditions. Both warming and litter addition also increased the seasonal average concentration of dissolved organic carbon in the soil. The site was a carbon sink with a net uptake of 60 g C m-2 over the snow-free season. However, warming reduced net carbon uptake by 77%, suggesting that this ecosystem type might shift from snow-free season sink to source with increasing summer temperatures.

  3. Trophic dynamics of shrinking Subarctic lakes: naturally eutrophic waters impart resilience to rising nutrient and major ion concentrations.

    Science.gov (United States)

    Lewis, Tyler L; Heglund, Patricia J; Lindberg, Mark S; Schmutz, Joel A; Schmidt, Joshua H; Dubour, Adam J; Rover, Jennifer; Bertram, Mark R

    2016-06-01

    Shrinking lakes were recently observed for several Arctic and Subarctic regions due to increased evaporation and permafrost degradation. Along with lake drawdown, these processes often boost aquatic chemical concentrations, potentially impacting trophic dynamics. In particular, elevated chemical levels may impact primary productivity, which may in turn influence populations of primary and secondary consumers. We examined trophic dynamics of 18 shrinking lakes of the Yukon Flats, Alaska, that had experienced pronounced increases in nutrient (>200 % total nitrogen, >100 % total phosphorus) and ion concentrations (>100 % for four major ions combined) from 1985-1989 to 2010-2012, versus 37 stable lakes with relatively little chemical change over the same period. We found that phytoplankton stocks, as indexed by chlorophyll concentrations, remained unchanged in both shrinking and stable lakes from the 1980s to 2010s. Moving up the trophic ladder, we found significant changes in invertebrate abundance across decades, including decreased abundance of five of six groups examined. However, these decadal losses in invertebrate abundance were not limited to shrinking lakes, occurring in lakes with stable surface areas as well. At the top of the food web, we observed that probabilities of lake occupancy for ten waterbird species, including adults and chicks, remained unchanged from the period 1985-1989 to 2010-2012. Overall, our study lakes displayed a high degree of resilience to multi-trophic cascades caused by rising chemical concentrations. This resilience was likely due to their naturally high fertility, such that further nutrient inputs had little impact on waters already near peak production.

  4. Enzymatic regulation of glycogenolysis in a subarctic population of the wood frog: implications for extreme freeze tolerance.

    Directory of Open Access Journals (Sweden)

    M Clara F do Amaral

    Full Text Available The wood frog, Rana sylvatica, from Interior Alaska survives freezing at -16°C, a temperature 10-13°C below that tolerated by its southern conspecifics. We investigated the hepatic freezing response in this northern phenotype to determine if its profound freeze tolerance is associated with an enhanced glucosic cryoprotectant system. Alaskan frogs had a larger liver glycogen reserve that was mobilized faster during early freezing as compared to conspecifics from a cool-temperate region (southern Ohio, USA. In Alaskan frogs the rapid glucose production in the first hours of freezing was associated with a 7-fold increase in glycogen phosphorylase activity above unfrozen frog levels, and the activity of this enzyme was higher than that of frozen Ohioan frogs. Freezing of Ohioan frogs induced a more modest (4-fold increase in glycogen phosphorylase activity above unfrozen frog values. Relative to the Ohioan frogs, Alaskan frogs maintained a higher total protein kinase A activity throughout an experimental freezing/thawing time course, and this may have potentiated glycogenolysis during early freezing. We found populational variation in the activity and protein level of protein kinase A which suggested that the Alaskan population had a more efficient form of this enzyme. Alaskan frogs modulated their glycogenolytic response by decreasing the activity of glycogen phosphorylase after cryoprotectant mobilization was well under way, thereby conserving their hepatic glycogen reserve. Ohioan frogs, however, sustained high glycogen phosphorylase activity until early thawing and consumed nearly all their liver glycogen. These unique hepatic responses of Alaskan R. sylvatica likely contribute to this phenotype's exceptional freeze tolerance, which is necessary for their survival in a subarctic climate.

  5. Warming of subarctic tundra increases emissions of all three important greenhouse gases - carbon dioxide, methane, and nitrous oxide.

    Science.gov (United States)

    Voigt, Carolina; Lamprecht, Richard E; Marushchak, Maija E; Lind, Saara E; Novakovskiy, Alexander; Aurela, Mika; Martikainen, Pertti J; Biasi, Christina

    2017-08-01

    Rapidly rising temperatures in the Arctic might cause a greater release of greenhouse gases (GHGs) to the atmosphere. To study the effect of warming on GHG dynamics, we deployed open-top chambers in a subarctic tundra site in Northeast European Russia. We determined carbon dioxide (CO 2 ), methane (CH 4 ), and nitrous oxide (N 2 O) fluxes as well as the concentration of those gases, inorganic nitrogen (N) and dissolved organic carbon (DOC) along the soil profile. Studied tundra surfaces ranged from mineral to organic soils and from vegetated to unvegetated areas. As a result of air warming, the seasonal GHG budget of the vegetated tundra surfaces shifted from a GHG sink of -300 to -198 g CO 2 -eq m -2 to a source of 105 to 144 g CO 2 -eq m -2 . At bare peat surfaces, we observed increased release of all three GHGs. While the positive warming response was dominated by CO 2 , we provide here the first in situ evidence of increasing N 2 O emissions from tundra soils with warming. Warming promoted N 2 O release not only from bare peat, previously identified as a strong N 2 O source, but also from the abundant, vegetated peat surfaces that do not emit N 2 O under present climate. At these surfaces, elevated temperatures had an adverse effect on plant growth, resulting in lower plant N uptake and, consequently, better N availability for soil microbes. Although the warming was limited to the soil surface and did not alter thaw depth, it increased concentrations of DOC, CO 2, and CH 4 in the soil down to the permafrost table. This can be attributed to downward DOC leaching, fueling microbial activity at depth. Taken together, our results emphasize the tight linkages between plant and soil processes, and different soil layers, which need to be taken into account when predicting the climate change feedback of the Arctic. © 2016 John Wiley & Sons Ltd.

  6. Late Cretaceous climate simulations with different CO2 levels and subarctic gateway configurations: A model-data comparison

    Science.gov (United States)

    Niezgodzki, Igor; Knorr, Gregor; Lohmann, Gerrit; Tyszka, Jarosław; Markwick, Paul J.

    2017-09-01

    We investigate the impact of different CO2 levels and different subarctic gateway configurations on the surface temperatures during the latest Cretaceous using the Earth System Model COSMOS. The simulated temperatures are compared with the surface temperature reconstructions based on a recent compilation of the latest Cretaceous proxies. In our numerical experiments, the CO2 level ranges from 1 to 6 times the preindustrial (PI) CO2 level of 280 ppm. On a global scale, the most reasonable match between modeling and proxy data is obtained for the experiments with 3 to 5 × PI CO2 concentrations. However, the simulated low- (high-) latitude temperatures are too high (low) as compared to the proxy data. The moderate CO2 levels scenarios might be more realistic, if we take into account proxy data and the dead zone effect criterion. Furthermore, we test if the model-data discrepancies can be caused by too simplistic proxy-data interpretations. This is distinctly seen at high latitudes, where most proxies are biased toward summer temperatures. Additional sensitivity experiments with different ocean gateway configurations and constant CO2 level indicate only minor surface temperatures changes (< 1°C) on a global scale, with higher values (up to 8°C) on a regional scale. These findings imply that modeled and reconstructed temperature gradients are to a large degree only qualitatively comparable, providing challenges for the interpretation of proxy data and/or model sensitivity. With respect to the latter, our results suggest that an assessment of greenhouse worlds is best constrained by temperatures in the midlatitudes.

  7. Climate Variability in the Subarctic Area for the Last Two Millennia: Influence of North Atlantic Sector and Millennial Trend.

    Science.gov (United States)

    Nicolle, M.; Debret, M.; Massei, N.; Hormes, A.; Swingedouw, D.; Christophe, C.; de Vernal, A.; Arctic 2k Working Group

    2016-12-01

    Understanding climate variability for the last two millennia is an key issue to propose new constraints on climate modeling. This study is based on the Arctic2k database compiled by the PAGES Arctic2k working group. All records meet several quality criteria concerning location, time period span, resolution and age-dating control. All the proxy used are sensitivity to temperature changes. The database high quality allows to investigate climate variability from millennial trend to high frequencies. There is spatially heterogeneous record distribution throughout the Arctic-subarctic area, most of the archives being located in the North Atlantic sector. We divided the study region into 3 sectors (Siberia, Alaska and North Atlantic areas) and compared them to the global Arctic2k temperature reconstruction using statistics and signal analysis method (wavelet coherence). Wavelet coherence allows investigation of the relationships in time-frequency space between two time series and identification of common variability. The results highlight better significant correlations between North Atlantic and global Arctic signals. The results is confirmed by wavelet coherence, showing common variability at centennial to multi-centennial scales. Millennial trends showed significant cooling trends before 1900 A.D., except for two records. Cooling trends are consistent with reconstructed temperatures for north hemisphere and warming trends seemed to be the results of regional particularity. Studying millennial variability also highlights the inconsistency between some marine proxies which reflect summer temperatures. The characterization of centennial to multidecadal variability will be an important issue to link the high frequency variability of paleoclimate series to low frequency variability recorded by instrumental data.

  8. Feeding ecology of mesopelagic zooplankton of the subtropical and subarctic North Pacific Ocean determined with fatty acid biomarkers

    Science.gov (United States)

    Wilson, S. E.; Steinberg, D. K.; Chu, F.-L. E.; Bishop, J. K. B.

    2010-10-01

    Mesopelagic zooplankton may meet their nutritional and metabolic requirements in a number of ways including consumption of sinking particles, carnivory, and vertical migration. How these feeding modes change with depth or location, however, is poorly known. We analyzed fatty acid (FA) profiles to characterize zooplankton diet and large particle (>51 μm) composition in the mesopelagic zone (base of euphotic zone -1000 m) at two contrasting time-series sites in the subarctic (station K2) and subtropical (station ALOHA) Pacific Ocean. Total FA concentration was 15.5 times higher in zooplankton tissue at K2, largely due to FA storage by seasonal vertical migrators such as Neocalanus and Eucalanus. FA biomarkers specific to herbivory implied a higher plant-derived food source at mesotrophic K2 than at oligotrophic ALOHA. Zooplankton FA biomarkers specific to dinoflagellates and diatoms indicated that diatoms, and to a lesser extent, dinoflagellates were important food sources at K2. At ALOHA, dinoflagellate FAs were more prominent. Bacteria-specific FA biomarkers in zooplankton tissue were used as an indicator of particle feeding, and peaks were recorded at depths where known particle feeders were present at ALOHA (e.g., ostracods at 100-300 m). In contrast, depth profiles of bacterial FA were relatively constant with depth at K2. Diatom, dinoflagellate, and bacterial biomarkers were found in similar proportions in both zooplankton and particles with depth at both locations, providing additional evidence that mesopelagic zooplankton consume sinking particles. Carnivory indices were higher and increased significantly with depth at ALOHA, and exhibited distinct peaks at K2, representing an increase in dependence on other zooplankton for food in deep waters. Our results indicate that feeding ecology changes with depth as well as by location. These changes in zooplankton feeding ecology from the surface through the mesopelagic zone, and between contrasting environments

  9. Enzymatic regulation of glycogenolysis in a subarctic population of the wood frog: implications for extreme freeze tolerance.

    Science.gov (United States)

    do Amaral, M Clara F; Lee, Richard E; Costanzo, Jon P

    2013-01-01

    The wood frog, Rana sylvatica, from Interior Alaska survives freezing at -16°C, a temperature 10-13°C below that tolerated by its southern conspecifics. We investigated the hepatic freezing response in this northern phenotype to determine if its profound freeze tolerance is associated with an enhanced glucosic cryoprotectant system. Alaskan frogs had a larger liver glycogen reserve that was mobilized faster during early freezing as compared to conspecifics from a cool-temperate region (southern Ohio, USA). In Alaskan frogs the rapid glucose production in the first hours of freezing was associated with a 7-fold increase in glycogen phosphorylase activity above unfrozen frog levels, and the activity of this enzyme was higher than that of frozen Ohioan frogs. Freezing of Ohioan frogs induced a more modest (4-fold) increase in glycogen phosphorylase activity above unfrozen frog values. Relative to the Ohioan frogs, Alaskan frogs maintained a higher total protein kinase A activity throughout an experimental freezing/thawing time course, and this may have potentiated glycogenolysis during early freezing. We found populational variation in the activity and protein level of protein kinase A which suggested that the Alaskan population had a more efficient form of this enzyme. Alaskan frogs modulated their glycogenolytic response by decreasing the activity of glycogen phosphorylase after cryoprotectant mobilization was well under way, thereby conserving their hepatic glycogen reserve. Ohioan frogs, however, sustained high glycogen phosphorylase activity until early thawing and consumed nearly all their liver glycogen. These unique hepatic responses of Alaskan R. sylvatica likely contribute to this phenotype's exceptional freeze tolerance, which is necessary for their survival in a subarctic climate.

  10. Evolution of the snow area index of the subarctic snowpack in central Alaska over a whole season. consequences for the air to snow transfer of pollutants.

    Science.gov (United States)

    Taillandier, A S; Domine, F; Simpson, W R; Sturm, M; Douglas, T A; Severin, K

    2006-12-15

    The detailed physical characteristics of the subarctic snowpack must be known to quantify the exchange of adsorbed pollutants between the atmosphere and the snow cover. For the first time, the combined evolutions of specific surface area (SSA), snow stratigraphy, temperature, and density were monitored throughout winter in central Alaska. We define the snow area index (SAI) as the vertically integrated surface area of snow crystals, and this variable is used to quantify pollutants' adsorption. Intense metamorphism generated by strong temperature gradients formed a thick depth hoar layer with low SSA (90 cm(2) g-1) and density (200 kg m(-3)), resulting in a low SAI. After snowpack buildup in autumn, the winter SAI remained around 1000 m(2)/m(2) of ground, much lower than the SAI of the Arctic snowpack, 2500 m(2) m-(2). With the example of PCBs 28 and 180, we calculate that the subarctic snowpack is a smaller reservoir of adsorbed pollutants than the Arctic snowpack and less efficiently transfers adsorbed pollutants from the atmosphere to ecosystems. The difference is greater for the more volatile PCB 28. With climate change, snowpack structure will be modified, and the snowpack's ability to transfer adsorbed pollutants from the atmosphere to ecosystems may be reduced, especially for the more volatile pollutants.

  11. Super-cooled liquid water topped sub-arctic clouds and precipitation - investigation based on combination of ground-based in-situ and remote-sensing observations

    Science.gov (United States)

    Hirsikko, Anne; Brus, David; O'Connor, Ewan J.; Filioglou, Maria; Komppula, Mika; Romakkaniemi, Sami

    2017-04-01

    In the high and mid latitudes super-cooled liquid water layers are frequently observed on top of clouds. These layers are difficult to forecast with numerical weather prediction models, even though, they have strong influence on atmospheric radiative properties, cloud microphysical properties, and subsequently, precipitation. This work investigates properties of super-cooled liquid water layer topped sub-arctic clouds and precipitation observed with ground-based in-situ (cloud probes) and remote-sensing (a cloud radar, Doppler and multi-wavelength lidars) instrumentation during two-month long Pallas Cloud Experiment (PaCE 2015) in autumn 2015. Analysis is based on standard Cloudnet scheme supplemented with new retrieval products of the specific clouds and their properties. Combination of two scales of observation provides new information on properties of clouds and precipitation in the sub-arctic Pallas region. Current status of results will be presented during the conference. The authors acknowledge financial support by the Academy of Finland (Centre of Excellence Programme, grant no 272041; and ICINA project, grant no 285068), the ACTRIS2 - European Union's Horizon 2020 research and innovation programme under grant agreement No 654109, the KONE foundation, and the EU FP7 project BACCHUS (grant no 603445).

  12. Summer (sub-arctic) versus winter (sub-tropical) production affects on spinach leaf bio-nutrients: Vitamins (C, E, Folate, K1, provitamin A), lutein, phenolics, and antioxidants

    Science.gov (United States)

    Comparison of spinach (Spinacia oleracea L.) cultivars Lazio and Samish grown during the summer solstice in the sub-arctic versus the winter solstice in the sub-tropics provided insight into interactions between plant environment (day length, light intensity, ambient temperatures), cultivar and leaf...

  13. Responses of fungal root colonization, plant cover and leaf nutrients to long-term exposure to elevated atmospheric CO2 and warming in a subarctic birch forest understory

    DEFF Research Database (Denmark)

    Olsrud, Maria; Carlsson, Bengt Å.; Svensson, Brita M.

    2010-01-01

    to the fungal symbionts. In this study, we investigated how ericoid mycorrhiza (ErM), fine endophytes (FE) and dark septate endophytes (DSE) in roots responded to elevated atmospheric CO2 concentrations and warming in the dwarf shrub understory of a birch forest in the subarctic region of northern Sweden...

  14. Resource Mobilization

    International Development Research Centre (IDRC) Digital Library (Canada)

    This practical guidebook supports and promotes new and creative thinking on resource mobilization for ... sources and come up with creative resource mobilization strategies to ensure survival. The Importance of ...... funds had already been earmarked for buying new classroom facilities. Maintain integrity of auction. 2.

  15. Mineral resources

    NARCIS (Netherlands)

    Henckens, M.L.C.M.; Ierland, van E.C.; Driessen, P.P.J.; Worrell, E.

    2016-01-01

    The extractable ores of the world's geologically scarcest mineral resources (e.g. antimony, molybdenum and zinc) may be exhausted within several decades to a century, if their extraction continues to increase. This paper explores the likelihood that these scarce mineral resources can be conserved

  16. Network topology of stable isotope interactions in a sub-arctic raptor guild.

    Science.gov (United States)

    Dalerum, F; Hellström, P; Miranda, M; Nyström, J; Ekenstedt, J; Angerbjörn, A

    2016-10-01

    Predation is an ecologically important process, and intra-guild interactions may substantially influence the ecological effects of predator species. Despite a rapid expansion in the use of mathematical graph theory to describe trophic relations, network approaches have rarely been used to study interactions within predator assemblages. Assemblages of diurnal raptors are subject to substantial intra- and interspecific competition. Here we used the novel approach of applying analyzes based on network topology to species-specific data on the stable isotopes (13)C and (15)N in feathers to evaluate patterns of relative resource utilization within a guild of diurnal raptors in northern Sweden. Our guild consisted of the golden eagle (Aquila chrysaetos), the gyrfalcon (Falco rusticolus), the peregrine falcon (Falco peregrinus) and the rough-legged buzzard (Buteo lagopus). We found a modular trophic interaction structure within the guild, but the interactions were less nested than expected by chance. These results suggest low redundancy and hence a strong ecological importance of individual species. Our data also suggested that species were less connected through intra-guild interactions than expected by chance. We interpret our results as a convergence on specific isotope niches, and that body size and different hunting behaviour may mediate competition within these niches. We finally highlight that generalist predators could be ecologically important by linking specialist predator species with disparate dietary niches.

  17. Genetic toxicology: web resources.

    Science.gov (United States)

    Young, Robert R

    2002-04-25

    Genetic toxicology is the scientific discipline dealing with the effects of chemical, physical and biological agents on the heredity of living organisms. The Internet offers a wide range of online digital resources for the field of Genetic Toxicology. The history of genetic toxicology and electronic data collections are reviewed. Web-based resources at US National Library of Medicine (NLM), including MEDLINE, PUBMED, Gateway, Entrez, and TOXNET, are discussed. Search strategies and Medical Subject Headings (MeSH) are reviewed in the context of genetic toxicology. The TOXNET group of databases are discussed with emphasis on those databases with genetic toxicology content including GENE-TOX, TOXLINE, Hazardous Substances Data Bank, Integrated Risk Information System, and Chemical Carcinogenesis Research Information System. Location of chemical information including chemical structure and linkage to health and regulatory information using CHEMIDPLUS at NLM and other databases is reviewed. Various government agencies have active genetic toxicology research programs or use genetic toxicology data to assist fulfilling the agency's mission. Online resources at the US Food and Drug Administration (FDA), the US Environmental Protection Agency (EPA), the National Institutes of Environmental Health Sciences, and the National Toxicology Program (NTP) are outlined. Much of the genetic toxicology for pharmaceuticals, industrial chemicals and pesticides that is performed in the world is regulatory-driven. Regulatory web resources are presented for the laws mandating testing, guidelines on study design, Good Laboratory Practice (GLP) regulations, and requirements for electronic data collection and reporting. The Internet provides a range of other supporting resources to the field of genetic toxicology. The web links for key professional societies and journals in genetic toxicology are listed. Distance education, educational media resources, and job placement services are also

  18. Results and conclusions of pine treeline advanced project in subarctic Finland

    Energy Technology Data Exchange (ETDEWEB)

    Siren, G.

    1997-12-31

    The original project components dealt with seed germination, soil conditions, competition, seedling ecology in and development. Subsequent research into flowering, seed maturation, dispersal and sexual development gained notable interest, as the uninhibited advance of the pine treeline continued. Since then the significant roles of repeated seed years and stand development became evident as stem numbers first increased and thereafter decreased. Improving bio-energy resources and quantifying the increasing CO{sub 2} sink dominated the sup-projects in the final stages. Ultimately the careful age and dry weight measurements and stem inventories prove decisively important in determining what factors were the main prerequisites for the advance of pine on forest-tundra and the development of the new CO{sub 2} sink. During the 20th century the favorable climate has promoted the advance of pine in the far north of Finland, which would appear to support the IPCC message of global warming. A consequence of this climate warming might be that the productive forest area in northernmost Finland will increase rather dramatically during the next century. Considering the longevity of pine, the standing productive forest stock and CO{sub 2} sink capacity would hence increase accordingly. It would therefore seem prudent to recommend the enhancement of conifer seed years and intensified experimentation with genetically tested conifer species throughout the circumpolar treeline regions. Consequently, through sustainable use of new biomass reserves, new areas south of the timberline could be opened to allow for potential ecological forestry practices and alternate energy sources could be developed. At the same time, this will create new employment opportunities for local people in all circumpolar regions.

  19. Patterns of distribution, abundance, and change over time in a subarctic marine bird community

    Science.gov (United States)

    Cushing, Daniel; Roby, Daniel D.; Irons, David B.

    2017-01-01

    Over recent decades, marine ecosystems of Prince William Sound (PWS), Alaska, have experienced concurrent effects of natural and anthropogenic perturbations, including variability in the climate system of the northeastern Pacific Ocean. We documented spatial and temporal patterns of variability in the summer marine bird community in relation to habitat and climate variability using boat-based surveys of marine birds conducted during the period 1989–2012. We hypothesized that a major factor structuring marine bird communities in PWS would be proximity to the shoreline, which is theorized to relate to aspects of food web structure. We also hypothesized that shifts in physical ecosystem drivers differentially affected nearshore-benthic and pelagic components of PWS food webs. We evaluated support for our hypotheses using an approach centered on community-level patterns of spatial and temporal variability. We found that an environmental gradient related to water depth and distance from shore was the dominant factor spatially structuring the marine bird community. Responses of marine birds to this onshore-offshore environmental gradient were related to dietary specialization, and separated marine bird taxa by prey type. The primary form of temporal variability over the study period was monotonic increases or decreases in abundance for 11 of 18 evaluated genera of marine birds; 8 genera had declined, whereas 3 had increased. The greatest declines occurred in genera associated with habitats that were deeper and farther from shore. Furthermore, most of the genera that declined primarily fed on pelagic prey resources, such as forage fish and mesozooplankton, and few were directly affected by the 1989 Exxon Valdez oil spill. Our observations of synchronous declines are indicative of a shift in pelagic components of PWS food webs. This pattern was correlated with climate variability at time-scales of several years to a decade.

  20. Electronic Resource Management System. Vernetzung von Lizenzinformationen

    OpenAIRE

    Michaela Selbach; Daniel Armin Rupp

    2014-01-01

    In den letzten zehn Jahren spielen elektronische Ressourcen im Bereich der Erwerbung eine zunehmend wichtige Rolle: Eindeutig lässt sich hier ein Wandel in den Bibliotheken (fort) vom reinen Printbestand zu immer größeren E-Only-Beständen feststellen. Die stetig wachsende Menge an E-Ressourcen und deren Heterogenität stellt Bibliotheken vor die Herausforderung, die E-Ressourcen effizient zu verwalten. Nicht nur Bibliotheken, sondern auch verhandlungsführende Institutionen von Konsortial- und ...

  1. Rethinking resources

    Energy Technology Data Exchange (ETDEWEB)

    Fisher, W.L. [Univ. of Texas, Austin, TX (United States)

    1994-09-01

    We class energy and mineral resources as finite because we are reasonably certain that they do not form at a rate remotely approaching man`s rate of use. We have certain environments of the earth that have limits in carrying capacity, and we presume that the global environment does as well. These facts and presumptions, coupled with anxieties over growth in population and consumption, have posed pictures of impending catastrophe from Malthus through the Club of Rome and currently, among certain advocates of what is called sustainable development. To avoid future calamity, command and control management of resource use is urged by many. But, quite simply, such management would presume a wisdom that historical experience suggests does not exist. As a recent example, consider natural gas resources. A decade and a half ago, the resource base of natural gas in the United States was judged to be near exhaustion. Estimates of remaining resources by governmental agencies, academicians, and several major energy companies indicated the ultimate resource would be at about 100 tcf today, with essential depletion by the end of the century. Such was the near universal wisdom that compelled Congress to enact legislation to outright prohibit certain use of natural gas. Today, after nearly eight years of gas supply in excess of demand and with entirely new appreciation of the impact of technology, estimates of the remaining gas resource by industry, government, and others are an order of magnitude greater than those made just 15 yr ago, and the same government that then sought to husband a resource presumed to be near depletion now aggressively promotes its use and consumption. Limits to resources and limits to environmental carrying capacity do indeed exist, but we have yet to define those limits and the paths thereto.

  2. Mineral Resources

    OpenAIRE

    Ababsa, Myriam

    2014-01-01

    Jordan’s natural resources are very limited: water is scarce, there is little arable land and the country has few sources of energy (fig. I.11). Jordan’s mineral industry has a long history: flint was used in prehistoric times and early copper mining started in Wadi Faynan during the Chalcolithic Period. The following is a brief presentation of Jordan’s resources. Mining and investments will be studied in Part 3. Figure I.11 — Jordan Mineral Resources. NRA 2012 Phosphates The Jordanian Natur...

  3. Model for Presenting Resources in Scholar's Portal

    Science.gov (United States)

    Feeney, Mary; Newby, Jill

    2005-01-01

    Presenting electronic resources to users through a federated search engine introduces unique opportunities and challenges to libraries. This article reports on the decision-making tools and processes used for selecting collections of electronic resources by a project team at the University of Arizona (UA) Libraries for the Association of Research…

  4. Monitoring of the invasive diatom Didymosphenia geminata in the subarctic and in alpine areas of southern Europe

    Science.gov (United States)

    Finger, David C.; Jónsson, Ingi R.; Cypaité, Vaiva; Ognjanova, Nadja; Ólafsson, Jón S.; Trichkova, Teodora

    2016-04-01

    In recent decades invasive species have been spreading across Europe. Although the perceptions of invasive species are divergent among researchers there is a general consent that invasive species endanger the diversity of native biota and hence should be monitored to initiate appropriate counter measures in drastic cases. Anthropogenic activities and climate change are the main cause for the enhanced spreading of non-native species to new environments. In this presentation we will present preliminary results from two aquatic case studies, one located in subarctic Iceland (River Elliðaár) and one in the high mountains of Bulgaria (the Seven Rila lakes), focusing on the freshwater diatom Didymosphenia geminata (Didymo). The diatom is a single cell algae which's natural habitat is cold fresh water environments with low nutrient content, i.e. mountainous areas in Europe, Asia and North America. In the last decades Didymo has been increasingly observed in new areas, e.g. Iceland, North America and New Zealand. Within the ESENIAS-TOOLS project two field excursions will identify the existence of Didymo in the two study sites and compare current abundance to previous observations. The preliminary results in the Rila Mountains, including both fossil and recent records, confirm that the occurrence of Didymo is restricted to Lake Bliznaka, the largest of the seven lakes located at lower altitude. In River Elliðaár preliminary results indicate a high abundance of Didymo along all sampling locations, confirming the invasive proliferation described in previous studies. The upscaling of the preliminary results from Elliðaár and Rila Mountains can help us to formulate general conclusions about the spreading of this invasive species. Furthermore, this bilateral cooperation can be further extended to other countries and hence contribute to a better management of invasive alien species in Europe. Acknowledgement: This study is part of ESENIAS - The East and South European

  5. A preliminary assessment of glacier melt-model parameter sensitivity and transferability in a dry subarctic environment

    Directory of Open Access Journals (Sweden)

    A. H. MacDougall

    2011-11-01

    Full Text Available Efforts to project the long-term melt of mountain glaciers and ice-caps require that melt models developed and calibrated for well studied locations be transferable over large regions. Here we assess the sensitivity and transferability of parameters within several commonly used melt models for two proximal sites in a dry subarctic environment of northwestern Canada. The models range in complexity from a classical degree-day model to a simplified energy-balance model. Parameter sensitivity is first evaluated by tuning the melt models to the output of an energy balance model forced with idealized inputs. This exercise allows us to explore parameter sensitivity both to glacier geometric attributes and surface characteristics, as well as to meteorological conditions. We then investigate the effect of model tuning with different statistics, including a weighted coefficient of determination (wR2, the Nash-Sutcliffe efficiency criterion (E, mean absolute error (MAE and root mean squared error (RMSE. Finally we examine model parameter transferability between two neighbouring glaciers over two melt seasons using mass balance data collected in the St. Elias Mountains of the southwest Yukon. The temperature-index model parameters appear generally sensitive to glacier aspect, mean surface elevation, albedo, wind speed, mean annual temperature and temperature lapse rate. The simplified energy balance model parameters are sensitive primarily to snow albedo. Model tuning with E, MAE and RMSE produces similar, or in some cases identical, parameter values. In twelve tests of spatial and/or temporal parameter transferability, the results with the lowest RMSE values with respect to ablation stake measurements were achieved twice with a classical temperature-index (degree-day model, three times with a temperature-index model in which the melt parameter is a function of potential radiation, and seven times with a simplified energy

  6. Role of EPS, Dispersant and Nutrients on the Microbial Response and MOS Formation in the Subarctic Northeast Atlantic

    Directory of Open Access Journals (Sweden)

    Tony Gutierrez

    2017-04-01

    Full Text Available In this study we report the formation of marine oil snow (MOS, its associated microbial community, the factors influencing its formation, and the microbial response to crude oil in surface waters of the Faroe-Shetland Channel (FSC. The FSC is a subarctic region that is hydrodynamically complex located in the northeast Atlantic where oil extraction is currently occurring and where exploration is likely to expand into its deeper waters (>500 m. A major oil spill in this region may mirror the aftermath that ensued following the Deepwater Horizon (DWH blowout in the Gulf of Mexico, where the massive influx of Macondo crude oil triggered the formation of copious quantities of rapidly sinking MOS and successional blooms of opportunistic oil-degrading bacteria. In laboratory experiments, we simulated environmental conditions in sea surface waters of the FSC using water collected from this site during the winter of 2015. We demonstrated that the presence of dispersant triggers the formation of MOS, and that nutrient amendments magnify this. Illumina MiSeq sequencing revealed the enrichment on MOS of associated oil-degrading (Cycloclasticus, Thalassolituus, Marinobacter and EPS-producing (Halomonas, Pseudoalteromonas, Alteromonas bacteria, and included major representation by Psychrobacter and Cobetia with putative oil-degrading/EPS-producing qualities. The formation of marine snow, in the absence of crude oil and dispersant, in seawater amended with nutrients alone indicated that the de novo synthesis of bacterial EPS is a key factor in MOS formation, and the glycoprotein composition of the MOS aggregates confirmed that its amorphous biopolymeric matrix was of microbial (likely bacterial origin. The presence of dispersants and crude oil with/without nutrients resulted in distinct microbial responses marked by intermittent, and in some cases short-lived, blooms of opportunistic heterotrophs, principally obligate hydrocarbonoclastic (Alcanivorax

  7. Challenges in modelling isoprene and monoterpene emission dynamics of Arctic plants: a case study from a subarctic tundra heath

    Science.gov (United States)

    Tang, Jing; Schurgers, Guy; Valolahti, Hanna; Faubert, Patrick; Tiiva, Päivi; Michelsen, Anders; Rinnan, Riikka

    2016-12-01

    The Arctic is warming at twice the global average speed, and the warming-induced increases in biogenic volatile organic compounds (BVOCs) emissions from Arctic plants are expected to be drastic. The current global models' estimations of minimal BVOC emissions from the Arctic are based on very few observations and have been challenged increasingly by field data. This study applied a dynamic ecosystem model, LPJ-GUESS, as a platform to investigate short-term and long-term BVOC emission responses to Arctic climate warming. Field observations in a subarctic tundra heath with long-term (13-year) warming treatments were extensively used for parameterizing and evaluating BVOC-related processes (photosynthesis, emission responses to temperature and vegetation composition). We propose an adjusted temperature (T) response curve for Arctic plants with much stronger T sensitivity than the commonly used algorithms for large-scale modelling. The simulated emission responses to 2 °C warming between the adjusted and original T response curves were evaluated against the observed warming responses (WRs) at short-term scales. Moreover, the model responses to warming by 4 and 8 °C were also investigated as a sensitivity test. The model showed reasonable agreement to the observed vegetation CO2 fluxes in the main growing season as well as day-to-day variability of isoprene and monoterpene emissions. The observed relatively high WRs were better captured by the adjusted T response curve than by the common one. During 1999-2012, the modelled annual mean isoprene and monoterpene emissions were 20 and 8 mg C m-2 yr-1, with an increase by 55 and 57 % for 2 °C summertime warming, respectively. Warming by 4 and 8 °C for the same period further elevated isoprene emission for all years, but the impacts on monoterpene emissions levelled off during the last few years. At hour-day scale, the WRs seem to be strongly impacted by canopy air T, while at the day-year scale, the WRs are a combined

  8. A Greener Arctic: Vascular Plant Litter Input in Subarctic Peat Bogs Changes Soil Invertebrate Diets and Decomposition Patterns

    Science.gov (United States)

    Krab, E. J.; Berg, M. P.; Aerts, R.; van Logtestijn, R. S. P.; Cornelissen, H. H. C.

    2014-12-01

    Climate-change-induced trends towards shrub dominance in subarctic, moss-dominated peatlands will most likely have large effects on soil carbon (C) dynamics through an input of more easily decomposable litter. The mechanisms by which this increase in vascular litter input interacts with the abundance and diet-choice of the decomposer community to alter C-processing have, however, not yet been unraveled. We used a novel 13C tracer approach to link invertebrate species composition (Collembola), abundance and species-specific feeding behavior to C-processing of vascular and peat moss litters. We incubated different litter mixtures, 100% Sphagnum moss litter, 100% Betula leaf litter, and a 50/50 mixture of both, in mesocosms for 406 days. We revealed the transfer of C from the litters to the soil invertebrate species by 13C labeling of each of the litter types and assessed 13C signatures of the invertebrates Collembola species composition differed significantly between Sphagnum and Betula litter. Within the 'single type litter' mesocosms, Collembola species showed different 13C signatures, implying species-specific differences in diet choice. Surprisingly, the species composition and Collembola abundance changed relatively little as a consequence of Betula input to a Sphagnum based system. Their diet choice, however, changed drastically; species-specific differences in diet choice disappeared and approximately 67% of the food ingested by all Collembola originated from Betula litter. Furthermore, litter decomposition patterns corresponded to these findings; mass loss of Betula increased from 16.1% to 26.2% when decomposing in combination with Sphagnum, while Sphagnum decomposed even slower in combination with Betula litter (1.9%) than alone (4.7%). This study is the first to empirically show that collective diet shifts of the peatland decomposer community from mosses towards vascular plant litter may drive altered decomposition patterns. In addition, we showed that

  9. Terrigenous fluxes of pollen, insect scale and land plant palynodebris observed by sediment traps deployed in the subarctic Pacific

    Science.gov (United States)

    Tsutsui, H.; Takahashi, K.; Matsuoka, K.; Jordan, R. W.; Yamamoto, S.

    2016-02-01

    From 1990 to 2009, sediment traps were deployed and recovered in the subarctic Pacific (Station SA; 49°N, 174°W) during each summer, allowing the long-term observation of particle fluxes. As the Pacific Decadal Oscillation index changed in 1999 while air temperatures cooled, this study focused on pollen, land plant debris and insect scale fluxes during 1994 to 2009 at Station SA. The maximum pollen and fern spores flux was 644 grains m2 d-1, with a mean of 74 grains m2 d-1and the following details: 65% of the total pollen counts represented by wind-pollinated trees (e.g., alder, birch and pine), 24% by the herbaceous plants, and 11% by fern spores. Spore, herbaceous and wind-pollinated tree pollen fluxes peaked primarily in May (and sporadically also in April and June) and September-October. The annual flux peaks of insect scales (of unknown origin) and land-plant debris were in May and September, but over the entire study period the maximum insect scale flux of 161 scales m2 d-1 was in August 2002, with a mean of 16 scales m2 d-1. Furthermore, the maximum (in August 2004) and mean land-plant debris fluxes were 107 and 10 plant fragments m2 d-1, respectively. The sediment traps were situated at southern side of the Aleutian Islands, where snow and ice occurred for six months from October to May. The ice-snow season accounts for 25% of the total annual particle flux, with 75% throughout the rest of the year. The correlation coefficient among pollen, insect scales and land plant debris are: 1) 0.58 (probability <1%) between wind-pollinated plant pollen and insect scales, and 2) 0.75 (probability <5%) between herbaceous plant pollen and land plant debris. The production locations, residence time, routes and mode of transport of the particles are important factors. The pollen fluxes observed during April to June appeared to have originated from the Western Alaska, but during the rest of years they appeared to have been from the eastern Russia. That pollen and other

  10. Arthritis - resources

    Science.gov (United States)

    Resources - arthritis ... The following organizations provide more information on arthritis : American Academy of Orthopaedic Surgeons -- orthoinfo.aaos.org/menus/arthritis.cfm Arthritis Foundation -- www.arthritis.org Centers for Disease Control and Prevention -- www. ...

  11. Seaweed resources

    Digital Repository Service at National Institute of Oceanography (India)

    Deshmukhe, G.V.; Dhargalkar, V.K.; Untawale, A

    The chapter summarizes our present knowledge of the seaweed resources of the Indian Ocean region with regard to the phytogeographical distribution, composition, biomass, utilization, cultivation, conservation and management. The voluminous data...

  12. Hemophilia - resources

    Science.gov (United States)

    Resources - hemophilia ... The following organizations provide further information on hemophilia : Centers for Disease Control and Prevention -- www.cdc.gov/ncbddd/hemophilia/index.html National Heart, Lung, and Blood Institute -- www.nhlbi.nih.gov/ ...

  13. Depression - resources

    Science.gov (United States)

    Resources - depression ... Depression is a medical condition. If you think you may be depressed, see a health care provider. ... following organizations are good sources of information on depression : American Psychological Association -- www.apa.org/topics/depress/ ...

  14. Diabetes - resources

    Science.gov (United States)

    Resources - diabetes ... The following sites provide further information on diabetes: American Diabetes Association -- www.diabetes.org Juvenile Diabetes Research Foundation International -- www.jdrf.org National Center for Chronic Disease Prevention and Health Promotion -- ...

  15. Forest Resources

    Energy Technology Data Exchange (ETDEWEB)

    None

    2016-06-01

    Forest biomass is an abundant biomass feedstock that complements the conventional forest use of wood for paper and wood materials. It may be utilized for bioenergy production, such as heat and electricity, as well as for biofuels and a variety of bioproducts, such as industrial chemicals, textiles, and other renewable materials. The resources within the 2016 Billion-Ton Report include primary forest resources, which are taken directly from timberland-only forests, removed from the land, and taken to the roadside.

  16. Automotive electronics design fundamentals

    CERN Document Server

    Zaman, Najamuz

    2015-01-01

    This book explains the topology behind automotive electronics architectures and examines how they can be profoundly augmented with embedded controllers. These controllers serve as the core building blocks of today’s vehicle electronics. Rather than simply teaching electrical basics, this unique resource focuses on the fundamental concepts of vehicle electronics architecture, and details the wide variety of Electronic Control Modules (ECMs) that enable the increasingly sophisticated "bells & whistles" of modern designs.  A must-have for automotive design engineers, technicians working in automotive electronics repair centers and students taking automotive electronics courses, this guide bridges the gap between academic instruction and industry practice with clear, concise advice on how to design and optimize automotive electronics with embedded controllers.

  17. Electronic Books for Secondary Students.

    Science.gov (United States)

    Anderson-Inman, Lynne; Horney, Mark

    1997-01-01

    Discusses the definition, purposes, and advantages and disadvantages of electronic books. Notes the types of embedded resources present in them, offers an example of an electronic book, and suggests three steps to evaluate and select electronic books for the curriculum. (SR)

  18. Primary productivity, nutrients, and other data from bottle casts in the Eastern Subarctic Pacific from the ENDEAVOUR and other platforms as part of the Outer Continental Shelf Environmental Assessment Program (OCSEAP) from 01 July 1958 to 25 July 1974 (NODC Accession 7601768)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Primary productivity, nutrients, and other data were collected from bottle casts in the Eastern Subarctic Pacific from the ENDEAVOUR and other platforms from 01 July...

  19. Page 1 GENDER ANALYSIS OF ELECTRONIC INFORMATION ...

    African Journals Online (AJOL)

    gender and the use of electronic information resources among postgraduate ... students were more likely to use electronic information resources than female ..... knowledge. Slow internet 16 6 6. Speed. Access problems 18 2 1. (limited time allotted, lots of information time consuming, passwords). Few resources 11 2 2.

  20. Power Electronics

    DEFF Research Database (Denmark)

    Iov, Florin; Ciobotaru, Mihai; Blaabjerg, Frede

    2008-01-01

    The global electrical energy consumption is still rising and there is an urgent demand to increase the power capacity. It is expected that the power capacity has to be doubled within 20 years. The production, distribution and use of energy should be as efficient as possible and incentives to save...... energy at the end-user should also be set up. Deregulation of energy has in the past lowered the investment in larger power plants, which means the need for new electrical power sources will be high in the near future. Two major technologies will play important roles to solve the future problems. One...... is to change the electrical power production sources from the conventional, fossil (and short term) based energy sources to renewable energy resources. The other is to use high efficient power electronics in power generation, power transmission/distribution and end-user application. This paper discuss the most...

  1. The Role of Eolian Dust Fertilization in Biogeochemical Cycles in The sub-Arctic Northwest Pacific During the Late Pliocene Intensification of Northern Hemisphere Glaciation

    Science.gov (United States)

    Bailey, I.; Liu, Q.; Swann, G.; Jiang, Z.; Sun, Y.; Zhao, X.; Roberts, A.

    2010-12-01

    Marine sediments recovered during Ocean Drilling Program (ODP) Leg 145 have improved our knowledge of climatic and oceanographic change in the North Pacific Ocean and surrounding landmasses during the last several million years. Of particular importance has been the analysis of high-latitude terrigenous sedimentary components sourced from the Asian continental interior via eolian deposition and from the circum-North Pacific landmasses via ice rafting. Teasing apart the relative contribution of eolian dust and ice-rafted debris (IRD) to deep sea sediments in the sub-Arctic Pacific is important for developing our understanding of late Pliocene ice-sheet evolution and the potential role of iron fertilization in biogeochemical cycles in the North Pacific Ocean. The magnetic properties of both eolian dust and IRD often have distinctive magnetic signatures, making environmental magnetism useful for investigating the relative importance of these sediment sources to bulk terrigenous inputs. Enhancements of the low-field volume magnetic susceptibility and the terrigenous sediment component from ODP Site 882 (~45°N) are classically interpreted to indicate a major onset of ice rafting to the sub-Arctic northwest Pacific Ocean during the late Pliocene (from ca MIS G6). On the other hand, studies of the eolian dust content of sediments from ODP Site 885, cored downwind of Site 882, indicate that dust deposition in the sub-Arctic Pacific increased markedly during MIS G6. This suggests that the classic interpretation of the magnetic susceptibility record at Site 882 requires reappraisal. To investigate the relative contribution of dust versus ice rafting to the Pliocene North Pacific, we present new high-resolution environmental magnetic and IRD records from ODP sites 882 and 885. We find that terrigenous inputs to both sites across MIS G6 were dominated by eolian dust (not IRD). Our findings call into question the reliability of magnetic susceptibility as a simple proxy for IRD

  2. Production and air-sea flux of halomethanes in the western subarctic Pacific in relation to phytoplankton pigment concentrations during the iron fertilization experiment (SEEDS II)

    Science.gov (United States)

    Hashimoto, Shinya; Toda, Shuji; Suzuki, Koji; Kato, Shungo; Narita, Yasusi; Kurihara, Michiko K.; Akatsuka, Yoko; Oda, Hiroshi; Nagai, Takahiro; Nagao, Ippei; Kudo, Isao; Uematsu, Mitsuo

    2009-12-01

    Iron could play a key role in controlling phytoplankton biomass and productivity in high-nutrient, low-chlorophyll regions. As a part of the iron fertilization experiment carried out in the western subarctic Pacific from July to August 2004 (Subarctic Pacific iron Experiment for Ecosystem Dynamics Study II—SEEDS II), we analysed the concentrations of trace gases in the seawater for 12 d following iron fertilization. The mean concentrations of chlorophyll a in the mixed layer (5-30 m depth) increased from 0.94 to 2.81 μg L -1 for 8 d in the iron patch. The mean concentrations of methyl bromide (CH 3Br; 5-30 m depth) increased from 6.4 to 13.4 pmol L -1 for 11 d; the in-patch concentration increased relative to the out-patch concentration. A linear correlation was observed between the concentrations of 19'-hexanoyloxyfucoxanthin, which is a biomarker of several prymnesiophytes, and CH 3Br in the seawater. After fertilization, the air-sea flux of CH 3Br inside the patch changed from influx to efflux from the ocean. There was no clear evidence for the increase in saturation anomaly of methyl chloride (CH 3Cl) due to iron fertilization. Furthermore, CH 3Cl fluxes did not show a tendency to increase after fertilization of the patch. In contrast to CH 3Br, no change was observed in the concentrations of bromoform (in-patch day 11 and out-patch day 11: 1.7 and 1.7 pmol L -1), dibromomethane (2.1 and 2.2 pmol L -1), and dibromochloromethane (1.0 and 1.2 pmol L -1, respectively). The concentration of isoprene, which is known to have a relationship with chlorophyll a, did not change in this study. The responses of trace gases during SEEDS II differed from the previous findings ( in situ iron enrichment experiment—EisenEx, Southern Ocean iron experiment—SOFeX, and Subarctic Ecosystem Response to Iron Enrichment Study—SERIES). Thus, in order to estimate the concomitant effect of iron fertilization on the climate, it is important to assess the induction of biological

  3. 18 CFR 390.1 - Electronic registration.

    Science.gov (United States)

    2010-04-01

    ... 18 Conservation of Power and Water Resources 1 2010-04-01 2010-04-01 false Electronic registration. 390.1 Section 390.1 Conservation of Power and Water Resources FEDERAL ENERGY REGULATORY COMMISSION, DEPARTMENT OF ENERGY PROCEDURAL RULES ELECTRONIC REGISTRATION § 390.1 Electronic registration. Any person who...

  4. Comparison of aerosol optical properties at the sub-arctic stations ALOMAR-Andenes, Abisko and Sodankylä in late spring and summer 2007

    Science.gov (United States)

    Rodríguez, E.; Toledano, C.; Cachorro, V.; de Leeuw, G.; De Frutos, A.; Gausa, M.; Holben, B.

    2012-04-01

    Aerosol concentration and aerosol type, retrieved from observations with CIMEL sun-photometers at three sub-arctic locations at the Scandinavian Peninsula are presented. The observations were made at ALOMAR-Andenes in Norway, Abisko in Sweden and Sodankylä in Finland. This field campaign took place in late spring and summer 2007 as part of the activities of the International Polar Year (IPY) within the POLARCAT project at ALOMAR and Abisko. Aerosol properties were characterized using the relationship between the aerosol optical depth and the Ångström Exponent. The characteristics of the predominant aerosol type and microphysics are largely determined by the location of the site (continental or coastal). During summer the fine mode particles dominate, as indicated by the fine mode volume fraction and the Ångström Exponent. The aerosol concentration was on average very low, except during an event in which long-range transported aerosols (dust and pollution) were detected.

  5. The fate of 13C15N labelled glycine in permafrost and surface soil at simulated thaw in mesocosms from high arctic and subarctic ecosystems

    DEFF Research Database (Denmark)

    Ravn, Nynne Marie Rand; Elberling, Bo; Michelsen, Anders

    2017-01-01

    glycine addition. Results: Near-surface soil microbes were more efficient in the uptake of intact glycine immediately upon thaw than plants. After one month plants had gained more 15N whereas microbes seemed to lose 15N originating from glycine. We observed a time lag in glycine degradation upon...... compound in thawing permafrost and surface soil. Methods: Double labeled glycine (13C15N) was added to soil columns with vegetation and to permafrost. During thaw conditions ecosystem respiration 13C was measured and 13C and 15N distribution in the ecosystem pools was quantified one day and one month after...... permafrost thaw, in contrast to surface soil thaw. Conclusions: Our results suggest that both arctic plants and microorganisms acquire amino acids released upon spring and permafrost thaw. Despite indications of more efficient utilization of added substrate in the High Arctic than the Subarctic, we conclude...

  6. Impact of mining and refining on the distribution and accumulation of nickel and other heavy metals in sediments of subarctic Lake Kuetsjärvi, Murmansk Region, Russia.

    Science.gov (United States)

    Dauvalter, Vladimir

    2003-04-01

    Research on the influence of the activities of Pechenganickel Mining and Metallurgical Company on sediment heavy-metal geochemistry of the subarctic Lake Kuetsjärvi (north-western Russia) are described. It is estimated that during 60 years of mining/refining activity, 310 t of Ni, 120 t of Cu, 14 t of Co, 19 t of Zn, 0.087 t of Cd, 0.78 t of Pb and 0.053 t of Hg have accumulated in the lake sediments. The latter can be a source of secondary pollution and represent a danger for the lake ecosystem. The sedimentation rate in the lake is estimated to be within the range of 1.5-3 mm year(-1). The average concentrations of Ni, Cu, Hg and Co in superficial sediments have increased 25, 14, 11 and 5 times, respectively in the last century.

  7. Impact of decade-long warming, nutrient addition and shading on emission and carbon isotopic composition of CO2 from two subarctic dwarf shrub heaths

    DEFF Research Database (Denmark)

    Ravn, Nynne R.; Ambus, Per Lennart; Michelsen, Anders

    2017-01-01

    This study investigated ecosystem respiration, soil respiration and carbon isotopic composition in CO2 emitted from two subarctic shrub heaths with contrasting moisture regimes. The reported measurements were conducted 22 years (mesic heath) and 12 years (wet heath) upon initiation of in situ...... and soil respiration was measured using closed chambers and CO2 in the soil profile was sampled with gas probes installed at different depths. At the mesic heath ecosystem respiration was increased 46% by warming while soil respiration increased 133% by nutrient addition. At the wet heath, warming...... climate change related manipulations of temperature, nutrient availability and light. The aim was to quantify expected climatic change effects on soil and ecosystem respiration, and to investigate whether the emitted CO2 originates from old carbon stores in the soil or from newly fixed carbon. Ecosystem...

  8. Growing season CH4 and N2O fluxes from a subarctic landscape in northern Finland; from chamber to landscape scale

    Science.gov (United States)

    Dinsmore, Kerry J.; Drewer, Julia; Levy, Peter E.; George, Charles; Lohila, Annalea; Aurela, Mika; Skiba, Ute M.

    2017-02-01

    Subarctic and boreal emissions of CH4 are important contributors to the atmospheric greenhouse gas (GHG) balance and subsequently the global radiative forcing. Whilst N2O emissions may be lower, the much greater radiative forcing they produce justifies their inclusion in GHG studies. In addition to the quantification of flux magnitude, it is essential that we understand the drivers of emissions to be able to accurately predict climate-driven changes and potential feedback mechanisms. Hence this study aims to increase our understanding of what drives fluxes of CH4 and N2O in a subarctic forest/wetland landscape during peak summer conditions and into the shoulder season, exploring both spatial and temporal variability, and uses satellite-derived spectral data to extrapolate from chamber-scale fluxes to a 2 km × 2 km landscape area.From static chamber measurements made during summer and autumn campaigns in 2012 in the Sodankylä region of northern Finland, we concluded that wetlands represent a significant source of CH4 (3.35 ± 0.44 mg C m-2 h-1 during the summer campaign and 0.62 ± 0.09 mg C m-2 h-1 during the autumn campaign), whilst the surrounding forests represent a small sink (-0.06 ± weighted by forest/wetland proportion (0.99 ± 0.16, 0.93 ± 0.12 mg C m-2 h-1, respectively). Hence we conclude that ignoring the detailed spatial variability in CH4 emissions within a landscape leads to a potentially significant underestimation of landscape-scale fluxes. Given the small magnitude of measured N2O fluxes a similar level of detailed upscaling was not needed; we conclude that N2O fluxes do not currently comprise an important component of the landscape-scale GHG budget at this site.

  9. Effects of warming on CO2, N2O and CH4 fluxes and underlying processes from subarctic tundra, Northwest Russia

    Science.gov (United States)

    Voigt, Carolina; Lamprecht, Richard E.; Marushchak, Maija E.; Biasi, Christina; Martikainen, Pertti J.

    2014-05-01

    Peatlands, especially those located in the highly sensitive arctic and subarctic latitudes, are known to play a major role in the global carbon cycle. Predicted climatic changes - entailing an increase in near-surface temperature and a change in precipitation patterns - will most likely have a serious yet uncertain impact on the greenhouse gas (GHG) balance of these ecosystems. Microbial processes are enhanced by warmer temperatures which may lead to increased trace gas fluxes to the atmosphere. However, the response of ecosystem processes and related GHG fluxes may differ largely across the landscape depending on soil type, vegetation cover, and moisture conditions. In this study we investigate how temperature increase potentially reflects on GHG fluxes (CO2, CH4 and N2O) from various tundra surfaces in the Russian Arctic. These surfaces include raised peat plateau complexes, mineral tundra soils, bare surfaces affected by frost action such as peat circles and thermokarst lake walls, as well as wetlands. Predicted temperature increase and climate change effects are simulated by means of open top chambers (OTCs), which are placed on different soil types for the whole snow-free period. GHG fluxes, gas and nutrient concentrations in the soil profile, as well as supporting environmental parameters are monitored for the full growing season. Aim of the study is not only the quantification of aboveground GHG fluxes from the study area, but the linking of those to underlying biogeochemical processes in permafrost soils. Special emphasis is placed on the interface between active layer and old permafrost and its response to warming, since little is known about the lability of old carbon stocks made available through an increase in active layer depth. Overall goal of the study is to gain a better understanding of C and N cycling in subarctic tundra soils and to deepen knowledge in respect to carbon-permafrost feedbacks in respect to climate.

  10. Uncertainty assessment of a polygon database of soil organic carbon for greenhouse gas reporting in Canada’s Arctic and sub-arctic

    Directory of Open Access Journals (Sweden)

    M.F. Hossain

    2014-08-01

    Full Text Available Canada’s Arctic and sub-arctic consist 46% of Canada’s landmass and contain 45% of the total soil organic carbon (SOC. Pronounced climate warming and increasing human disturbances could induce the release of this SOC to the atmosphere as greenhouse gases. Canada is committed to estimating and reporting the greenhouse gases emissions and removals induced by land use change in the Arctic and sub-arctic. To assess the uncertainty of the estimate, we compiled a site-measured SOC database for Canada’s north, and used it to compare with a polygon database, that will be used for estimating SOC for the UNFCCC reporting. In 10 polygons where 3 or more measured sites were well located in each polygon, the site-averaged SOC content agreed with the polygon data within ±33% for the top 30 cm and within ±50% for the top 1 m soil. If we directly compared the SOC of the 382 measured sites with the polygon mean SOC, there was poor agreement: The relative error was less than 50% at 40% of the sites, and less than 100% at 68% of the sites. The relative errors were more than 400% at 10% of the sites. These comparisons indicate that the polygon database is too coarse to represent the SOC conditions for individual sites. The difference is close to the uncertainty range for reporting. The spatial database could be improved by relating site and polygon SOC data with more easily observable surface features that can be identified and derived from remote sensing imagery.

  11. The Electron

    Energy Technology Data Exchange (ETDEWEB)

    Thomson, George

    1972-01-01

    Electrons are elementary particles of atoms that revolve around and outside the nucleus and have a negative charge. This booklet discusses how electrons relate to electricity, some applications of electrons, electrons as waves, electrons in atoms and solids, the electron microscope, among other things.

  12. A community-based participatory approach and engagement process creates culturally appropriate and community informed pandemic plans after the 2009 H1N1 influenza pandemic: remote and isolated First Nations communities of sub-arctic Ontario, Canada.

    Science.gov (United States)

    Charania, Nadia A; Tsuji, Leonard J S

    2012-04-03

    Public health emergencies have the potential to disproportionately impact disadvantaged populations due to pre-established social and economic inequalities. Internationally, prior to the 2009 H1N1 influenza pandemic, existing pandemic plans were created with limited public consultation; therefore, the unique needs and characteristics of some First Nations communities may not be ethically and adequately addressed. Engaging the public in pandemic planning can provide vital information regarding local values and beliefs that may ultimately lead to increased acceptability, feasibility, and implementation of pandemic plans. Thus, the objective of the present study was to elicit and address First Nations community members' suggested modifications to their community-level pandemic plans after the 2009 H1N1 influenza pandemic. The study area included three remote and isolated First Nations communities located in sub-arctic Ontario, Canada. A community-based participatory approach and community engagement process (i.e., semi-directed interviews (n = 13), unstructured interviews (n = 4), and meetings (n = 27)) were employed. Participants were purposively sampled and represented various community stakeholders (e.g., local government, health care, clergy, education, etc.) involved in the community's pandemic response. Collected data were manually transcribed and coded using deductive and inductive thematic analysis. The data subsequently informed the modification of the community-level pandemic plans. The primary modifications incorporated in the community-level pandemic plans involved adding community-specific detail. For example, 'supplies' emerged as an additional category of pandemic preparedness and response, since including details about supplies and resources was important due to the geographical remoteness of the study communities. Furthermore, it was important to add details of how, when, where, and who was responsible for implementing recommendations

  13. Geomorphic (de-) coupling of hillslope and channel systems within headwater catchments in two subarctic tributary valleys, Nordfjord, Western Norway

    Science.gov (United States)

    Laute, Katja; Beylich, Achim A.

    2010-05-01

    Hillslopes occupy large areas of the earth surface. Studying the characteristics, development and interaction of hillslopes as components of the geomorphic hillslope-channel coupling process-response system will improve the understanding of the complex response of mountain landscape formation. The rates of hillslope processes are exceptionally varied and affected by many influences of varying intensity. Hillslope-channel coupling and sediment storage within slopes are important factors that influence sediment delivery through catchments, especially in steep environments. Within sediment transfers from sources to sinks in drainage basins, hillslopes function as a key element concerning sediment storage, both for short term periods as between rainstorms as well as for longer periods in colluvial deposits. This PhD project is part of the NFR funded SedyMONT-Norway project within the ESF TOPO-EUROPE SedyMONT (Timescales of sediment dynamics, climate and topographic change in mountain landscapes) programme. The focus of this study is on geomorphic hillslope-channel coupling or de-coupling and sediment transport within four distinct headwater areas of the Erdalen and Bødalen catchments in the Nordfjord valley-fjord system (inner Nordfjord, Western Norway). Both catchments can be described as steep, U-shaped and glacier-fed, subarctic tributary valleys. Approximately 14% of the 49 km2 large headwater area of Erdalen is occupied by hillslope deposits; in Bødalen hillslope deposits occupy 12% of the 42 km2 large headwater area. The main aims of the study are to present preliminary findings on (i) the identification of possible sediment sources and delivery pathways within the headwater areas of the catchments, (ii) to analyze the development of hillslope-channel coupling / de-coupling from postglacial to contemporary timescales as well as (iii) to investigate the current degree of geomorphic hillslope-channel coupling within the different headwater catchments and (iv) to

  14. Electron radiography

    Science.gov (United States)

    Merrill, Frank E.; Morris, Christopher

    2005-05-17

    A system capable of performing radiography using a beam of electrons. Diffuser means receive a beam of electrons and diffuse the electrons before they enter first matching quadrupoles where the diffused electrons are focused prior to the diffused electrons entering an object. First imaging quadrupoles receive the focused diffused electrons after the focused diffused electrons have been scattered by the object for focusing the scattered electrons. Collimator means receive the scattered electrons and remove scattered electrons that have scattered to large angles. Second imaging quadrupoles receive the collimated scattered electrons and refocus the collimated scattered electrons and map the focused collimated scattered electrons to transverse locations on an image plane representative of the electrons' positions in the object.

  15. Algae Resources

    Energy Technology Data Exchange (ETDEWEB)

    None

    2016-06-01

    Algae are highly efficient at producing biomass, and they can be found all over the planet. Many use sunlight and nutrients to create biomass, which contain key components—including lipids, proteins, and carbohydrates— that can be converted and upgraded to a variety of biofuels and products. A functional algal biofuels production system requires resources such as suitable land and climate, sustainable management of water resources, a supplemental carbon dioxide (CO2) supply, and other nutrients (e.g., nitrogen and phosphorus). Algae can be an attractive feedstock for many locations in the United States because their diversity allows for highpotential biomass yields in a variety of climates and environments. Depending on the strain, algae can grow by using fresh, saline, or brackish water from surface water sources, groundwater, or seawater. Additionally, they can grow in water from second-use sources such as treated industrial wastewater; municipal, agricultural, or aquaculture wastewater; or produced water generated from oil and gas drilling operations.

  16. Resource Management

    Science.gov (United States)

    1993-01-01

    Summit Envirosolutions of Minneapolis, Minnesota, used remote sensing images as a source for groundwater resource management. Summit is a full-service environmental consulting service specializing in hydrogeologic, environmental management, engineering and remediation services. CRSP collected, processed and analyzed multispectral/thermal imagery and aerial photography to compare remote sensing and Geographic Information System approaches to more traditional methods of environmental impact assessments and monitoring.

  17. Sphagnum-dwelling testate amoebae in subarctic bogs are more sensitive to soil warming in the growing season than in winter: the results of eight-year field climate manipulations.

    Science.gov (United States)

    Tsyganov, Andrey N; Aerts, Rien; Nijs, Ivan; Cornelissen, Johannes H C; Beyens, Louis

    2012-05-01

    Sphagnum-dwelling testate amoebae are widely used in paleoclimate reconstructions as a proxy for climate-induced changes in bogs. However, the sensitivity of proxies to seasonal climate components is an important issue when interpreting proxy records. Here, we studied the effects of summer warming, winter snow addition solely and winter snow addition together with spring warming on testate amoeba assemblages after eight years of experimental field climate manipulations. All manipulations were accomplished using open top chambers in a dry blanket bog located in the sub-Arctic (Abisko, Sweden). We estimated sensitivity of abundance, diversity and assemblage structure of living and empty shell assemblages of testate amoebae in the living and decaying layers of Sphagnum. Our results show that, in a sub-arctic climate, testate amoebae are more sensitive to climate changes in the growing season than in winter. Summer warming reduced species richness and shifted assemblage composition towards predominance of xerophilous species for the living and empty shell assemblages in both layers. The higher soil temperatures during the growing season also decreased abundance of empty shells in both layers hinting at a possible increase in their decomposition rates. Thus, although possible effects of climate changes on preservation of empty shells should always be taken into account, species diversity and structure of testate amoeba assemblages in dry subarctic bogs are sensitive proxies for climatic changes during the growing season. Copyright © 2011 Elsevier GmbH. All rights reserved.

  18. Energy resources

    CERN Document Server

    Simon, Andrew L

    1975-01-01

    Energy Resources mainly focuses on energy, including its definition, historical perspective, sources, utilization, and conservation. This text first explains what energy is and what its uses are. This book then explains coal, oil, and natural gas, which are some of the common energy sources used by various industries. Other energy sources such as wind, solar, geothermal, water, and nuclear energy sources are also tackled. This text also looks into fusion energy and techniques of energy conversion. This book concludes by explaining the energy allocation and utilization crisis. This publ

  19. The Biomedical Resource Ontology (BRO) to Enable Resource Discovery in Clinical and Translational Research

    Science.gov (United States)

    Tenenbaum, Jessica D.; Whetzel, Patricia L.; Anderson, Kent; Borromeo, Charles D.; Dinov, Ivo D.; Gabriel, Davera; Kirschner, Beth; Mirel, Barbara; Morris, Tim; Noy, Natasha; Nyulas, Csongor; Rubenson, David; Saxman, Paul R.; Singh, Harpreet; Whelan, Nancy; Wright, Zach; Athey, Brian D.; Becich, Michael J.; Ginsburg, Geoffrey S.; Musen, Mark A.; Smith, Kevin A.; Tarantal, Alice F.; Rubin, Daniel L; Lyster, Peter

    2010-01-01

    The biomedical research community relies on a diverse set of resources, both within their own institutions and at other research centers. In addition, an increasing number of shared electronic resources have been developed. Without effective means to locate and query these resources, it is challenging, if not impossible, for investigators to be aware of the myriad resources available, or to effectively perform resource discovery when the need arises. In this paper, we describe the development and use of the Biomedical Resource Ontology (BRO) to enable semantic annotation and discovery of biomedical resources. We also describe the Resource Discovery System (RDS) which is a federated, inter-institutional pilot project that uses the BRO to facilitate resource discovery on the Internet. Through the RDS framework and its associated Biositemaps infrastructure, the BRO facilitates semantic search and discovery of biomedical resources, breaking down barriers and streamlining scientific research that will improve human health. PMID:20955817

  20. Pristine Arctic: Background mapping of PAHs, PAH metabolites and inorganic trace elements in the North-Atlantic Arctic and sub-Arctic coastal environment

    Energy Technology Data Exchange (ETDEWEB)

    Jörundsdóttir, Hrönn Ólína, E-mail: hronn.o.jorundsdottir@matis.is [Matis Ltd., Icelandic Food and Biotech R and D, Vinlandsleid 12, 113 Reykjavik (Iceland); Jensen, Sophie [Matis Ltd., Icelandic Food and Biotech R and D, Vinlandsleid 12, 113 Reykjavik (Iceland); Hylland, Ketil; Holth, Tor Fredrik [Department of Biosciences, University of Oslo, P.O. Box 1066 Blindern, N-0316 Oslo (Norway); Gunnlaugsdóttir, Helga [Matis Ltd., Icelandic Food and Biotech R and D, Vinlandsleid 12, 113 Reykjavik (Iceland); Svavarsson, Jörundur [University of Iceland, Department of Life and Environmental Sciences, Askja - Natural Science Building, Sturlugata 7, 101 Reykjavík (Iceland); Ólafsdóttir, Ásdís [The University of Iceland´s Research Centre in Sudurnes, Gardvegi 1, 245 Sandgerdi (Iceland); El-Taliawy, Haitham [Matis Ltd., Icelandic Food and Biotech R and D, Vinlandsleid 12, 113 Reykjavik (Iceland); Rigét, Frank; Strand, Jakob [Department of Bioscience, Arctic Research Centre, Aarhus University, Frederiksborgvej 399, PO Box 358, DK-4000 Roskilde (Denmark); Nyberg, Elisabeth; Bignert, Anders [Swedish Museum of Natural History, P.O. Box 50007, 104 05 Stockholm (Sweden); Hoydal, Katrin S. [The Faroese Environment Agency, Traðagøta 38, P.O. Box 2048, FO-165 Argir, the Faroe Islands (Faroe Islands); Halldórsson, Halldór Pálmar [The University of Iceland´s Research Centre in Sudurnes, Gardvegi 1, 245 Sandgerdi (Iceland)

    2014-09-15

    As the ice cap of the Arctic diminishes due to global warming, the polar sailing route will be open larger parts of the year. These changes are likely to increase the pollution load on the pristine Arctic due to large vessel traffic from specific contaminant groups, such as polycyclic aromatic hydrocarbons (PAHs). A well-documented baseline for PAH concentrations in the biota in the remote regions of the Nordic Seas and the sub-Arctic is currently limited, but will be vital in order to assess future changes in PAH contamination in the region. Blue mussels (Mytilus edulis) were collected from remote sites in Greenland, Iceland, the Faroe Islands, Norway and Sweden as well as from urban sites in the same countries for comparison. Cod (Gadus morhua) was caught north of Iceland and along the Norwegian coast. Sixteen priority PAH congeners and the inorganic trace elements arsenic, cadmium, mercury and lead were analysed in the blue mussel samples as well as PAH metabolites in cod bile. Σ{sub 16}PAHs ranged from 28 ng/g dry weight (d.w.) (Álftafjörður, NW Iceland) to 480 ng/g d.w. (Ísafjörður, NW Iceland). Mussel samples from Mjóifjörður, East Iceland and Maarmorilik, West Greenland, contained elevated levels of Σ{sub 16}PAHs, 370 and 280 ng/g d.w., respectively. Levels of inorganic trace elements varied with highest levels of arsenic in mussels from Ísafjörður, Iceland (79 ng/g d.w.), cadmium in mussels from Mjóifjörður, Iceland (4.3 ng/g d.w.), mercury in mussels from Sørenfjorden, Norway (0.23 ng/g d.w.) and lead in mussels from Maarmorilik, Greenland (21 ng/g d.w.). 1-OH-pyrene was only found above limits of quantification (0.5 ng/mL) in samples from the Norwegian coast, ranging between 44 and 140 ng/ml bile. Generally, PAH levels were low in mussels from the remote sites investigated in the study, which indicates limited current effect on the environment. - Highlights: • Low levels of PAHs in blue mussels from remote areas of the Arctic. • Low

  1. Comparison of Vegetation Water Use Using the Horton Index in a Sub-arctic, Alaskan Boreal Forest Environment Using Hydrograph Analysis

    Science.gov (United States)

    Bolton, W. R.; Cable, J.

    2012-12-01

    The sub-arctic environment is in the zone of discontinuous permafrost. The extreme energy influx from winter to summer has a strong influence on water storage and release processes at the watershed scale. For example, the seven months of snow accumulation are followed by a short 2-week period of snow ablation in which approximately 1/3 of the annual precipitation is released into the system. In permafrost soils, the soils begin to thaw immediately at the conclusion of snow melt, increasing the storage capacity of the soils. The storage capacity of the soils reaches a maximum in late summer then rapidly decreases during the freeze-back period in October. In permafrost-free soils dominated by deciduous vegetation, the trees appear to have a major role in taking up and transpiring liquid precipitation to back to the atmosphere. Conversely, in permafrost soils dominated by coniferous vegetation, the trees appear to have a more minor role in the cycling of liquid water during precipitation events. The overarching goal of our research is to quantify the relative roles of vegetation water use and soil storage dynamics associated with permafrost presence/absence in determining the magnitude and timing of water pathways in the sub-Arctic boreal forest. As part of this goal, we quantified the Horton Index - a metric used to describe vegetation water use relative to available soil water - in two small sub-basins of the Caribou-Poker Creeks Research Watershed, located near Fairbanks, Alaska. The C2 (5.2 km2) and C3 (5.7km2) sub-basins are underlain by approximately 2 and 53% permafrost, and are dominated by deciduous (Betula neoalaskana and Populus tremuloides) and coniferous vegetation (Picea mariana), respectively. Catchment scale calculations of the Horton Index are made using stream flow analysis and during snow-free precipitation events over an 11-year period. In each sub-basin, the Horton Index varies with time with the greatest variation occurring in the spring and fall

  2. Ecosystem nitrogen fixation throughout the snow-free period in subarctic tundra: effects of willow and birch litter addition and warming.

    Science.gov (United States)

    Rousk, Kathrin; Michelsen, Anders

    2017-04-01

    Nitrogen (N) fixation in moss-associated cyanobacteria is one of the main sources of available N for N-limited ecosystems such as subarctic tundra. Yet, N2 fixation in mosses is strongly influenced by soil moisture and temperature. Thus, temporal scaling up of low-frequency in situ measurements to several weeks, months or even the entire growing season without taking into account changes in abiotic conditions cannot capture the variation in moss-associated N2 fixation. We therefore aimed to estimate moss-associated N2 fixation throughout the snow-free period in subarctic tundra in field experiments simulating climate change: willow (Salix myrsinifolia) and birch (Betula pubescens spp. tortuosa) litter addition, and warming. To achieve this, we established relationships between measured in situ N2 fixation rates and soil moisture and soil temperature and used high-resolution measurements of soil moisture and soil temperature (hourly from May to October) to model N2 fixation. The modelled N2 fixation rates were highest in the warmed (2.8 ± 0.3 kg N ha-1 ) and birch litter addition plots (2.8 ± 0.2 kg N ha-1 ), and lowest in the plots receiving willow litter (1.6 ± 0.2 kg N ha-1 ). The control plots had intermediate rates (2.2 ± 0.2 kg N ha-1 ). Further, N2 fixation was highest during the summer in the warmed plots, but was lowest in the litter addition plots during the same period. The temperature and moisture dependence of N2 fixation was different between the climate change treatments, indicating a shift in the N2 fixer community. Our findings, using a combined empirical and modelling approach, suggest that a longer snow-free period and increased temperatures in a future climate will likely lead to higher N2 fixation rates in mosses. Yet, the consequences of increased litter fall on moss-associated N2 fixation due to shrub expansion in the Arctic will depend on the shrub species' litter traits. © 2016 John Wiley & Sons Ltd.

  3. Ten-year trends of atmospheric mercury in the high Arctic compared to Canadian sub-Arctic and mid-latitude sites

    Directory of Open Access Journals (Sweden)

    A. S. Cole

    2013-02-01

    Full Text Available Global emissions of mercury continue to change at the same time as the Arctic is experiencing ongoing climatic changes. Continuous monitoring of atmospheric mercury provides important information about long-term trends in the balance between transport, chemistry, and deposition of this pollutant in the Arctic atmosphere. Ten-year records of total gaseous mercury (TGM from 2000 to 2009 were analyzed from two high Arctic sites at Alert (Nunavut, Canada and Zeppelin Station (Svalbard, Norway; one sub-Arctic site at Kuujjuarapik (Nunavik, Québec, Canada; and three temperate Canadian sites at St. Anicet (Québec, Kejimkujik (Nova Scotia and Egbert (Ontario. Five of the six sites examined showed a decreasing trend over this time period. Overall trend estimates at high latitude sites were: −0.9% yr−1 (95% confidence limits: −1.4, 0 at Alert and no trend (−0.5, +0.7 at Zeppelin Station. Faster decreases were observed at the remainder of the sites: −2.1% yr−1 (−3.1, −1.1 at Kuujjuarapik, −1.9% yr−1 (−2.1, −1.8 at St. Anicet, −1.6% yr−1 (−2.4, −1.0 at Kejimkujik and −2.2% yr−1 (−2.8, −1.7 at Egbert. Trends at the sub-Arctic and mid-latitude sites agree with reported decreases in background TGM concentration since 1996 at Mace Head, Ireland, and Cape Point, South Africa, but conflict with estimates showing an increase in global anthropogenic emissions over a similar period. Trends in TGM at the two high Arctic sites were not only less negative (or neutral overall but much more variable by season. Possible reasons for differences in seasonal and overall trends at the Arctic sites compared to those at lower latitudes are discussed, as well as implications for the Arctic mercury cycle. The first calculations of multi-year trends in reactive gaseous mercury (RGM and total particulate mercury (TPM at Alert were also performed, indicating increases from 2002 to 2009

  4. Oscillator clustering in a resource distribution chain

    DEFF Research Database (Denmark)

    Postnov, D.; Sosnovtseva, Olga; Mosekilde, Erik

    2005-01-01

    separate the inherent dynamics of the individual oscillator from the properties of the coupling network. Illustrated by examples from microbiological population dynamics, renal physiology, and electronic oscillator theory, we show how competition for primary resources in a resource distribution chain leads...

  5. Information resources

    Science.gov (United States)

    Friend, Milton; Franson, J. Christian; Friend, Milton; Gibbs, Samantha E.J.; Wild, Margaret A.

    2015-10-19

    During recent decades, natural resources agency personnel and others involved with the management and stewardship of wildlife have experienced an increasing need to access information and obtain technical assistance for addressing a diverse array of wildlife disease issues. This Chapter provides a broad overview of selected sources for obtaining supplemental information and technical assistance for addressing wildlife disease issues in North America. Specifically, examples of existing major wildlife disease programs focusing on free-ranging wildlife populations are highlighted; training opportunities for enhancing within-agency wildlife disease response are identified; a selected reading list of wildlife disease references is provided; and selected Web sites providing timely information on wildlife disease are highlighted. No attempt is made to detail all the North American programs and capabilities that address disease in free-ranging wildlife populations. Instead, this Chapter is focused on enhancing awareness of the types of capabilities that exist as potential sources for assistance and collaboration between wildlife conservation agency personnel and others in addressing wildlife disease issues.

  6. Uptake of pulse injected nitrogen by soil microbes and mycorrhizal and non-mycorrhizal plants in a species-diverse subarctic heath ecosystem

    DEFF Research Database (Denmark)

    Andresen, Louise Christoffersen; Jonasson, Sven; Strom, Lena

    2008-01-01

    15N labeled ammonium, glycine or glutamic acid was injected into subarctic heath soil in situ, with the purpose of investigating how the nitrogen added in these pulses was subsequently utilized and cycled in the ecosystem. We analyzed the acquisition of 15N label in mycorrhizal and non-mycorrhiza......, the differences in 15N uptake patterns may also be due to differences in leaf longevity and woodiness between plant functional groups.......-mycorrhizal plants and in soil microorganisms, in order to reveal probable differences in acquisition patterns between the two functional plant types and between plants and soil microorganisms. Three weeks after the label addition, with the 15N-forms added with same amount of nitrogen per square meter, we analyzed...... the 15N-enrichment in total soil, in soil K2SO4 (0.5 M) extracts and in the microbial biomass after vacuum-incubation of soil in chloroform and subsequent K2SO4 extraction. Furthermore the 15N-enrichment was analyzed in current years leaves of the dominant plant species sampled three, five and 21 days...

  7. Flourish or flush: effects of simulated extreme rainfall events on Sphagnum-dwelling testate amoebae in a subarctic bog (Abisko, Sweden).

    Science.gov (United States)

    Tsyganov, Andrey N; Keuper, Frida; Aerts, Rien; Beyens, Louis

    2013-01-01

    Extreme precipitation events are recognised as important drivers of ecosystem responses to climate change and can considerably affect high-latitude ombrotrophic bogs. Therefore, understanding the relationships between increased rainfall and the biotic components of these ecosystems is necessary for an estimation of climate change impacts. We studied overall effects of increased magnitude, intensity and frequency of rainfall on assemblages of Sphagnum-dwelling testate amoebae in a field climate manipulation experiment located in a relatively dry subarctic bog (Abisko, Sweden). The effects of the treatment were estimated using abundance, species diversity and structure of living and empty shell assemblages of testate amoebae in living and decaying layers of Sphagnum. Our results show that increased rainfall reduced the mean abundance and species richness of living testate amoebae. Besides, the treatment affected species structure of both living and empty shell assemblages, reducing proportions of hydrophilous species. The effects are counterintuitive as increased precipitation-related substrate moisture was expected to have opposite effects on testate amoeba assemblages in relatively dry biotopes. Therefore, we conclude that other rainfall-related factors such as increased infiltration rates and frequency of environmental disturbances can also affect testate amoeba assemblages in Sphagnum and that hydrophilous species are particularly sensitive to variation in these environmental variables.

  8. Atmospheric controls on methane emissions from a subarctic bog in northern Quebec, Canada, using an open-path eddy covariance system

    Science.gov (United States)

    Rousseau, A. N.; Nadeau, D. F.; Parlange, M. B.; Coursolle, C.; Margolis, H. A.

    2012-12-01

    Wetlands are the largest natural source of atmospheric methane, a powerful greenhouse gas. Over such environments, methane fluxes are traditionally quantified with static or dynamic chambers and gas chromatography. Although inexpensive and portable, this method does not allow for continuous measurements besides not capturing the effect of atmospheric turbulence on methane emissions. An alternative is closed-path eddy covariance systems, but these usually require high power consumption and regular maintenance, both of which are difficult to supply in highly remote areas where most Canadian wetlands are found. In this study we deployed the new open-path methane analyzer (model Li-7700) from Li-Cor inc. along with surface energy budget sensors over a 60-ha subarctic bog from June to September 2012. The field site (53.7°N, 78.2°W) is located near James Bay within the La Grande Rivière watershed. This work discusses the presence of diurnal patterns in turbulent methane fluxes, and analyzes the effect of atmospheric stability, turbulence intensity and other atmospheric controls on fluxes magnitude and timing. Methane emissions are also quantified at the daily scale and compared to previously reported values over similar sites with other methods. A more technical discussion is also included in which advantages, drawbacks and optimal setup configuration of the instrument are presented.

  9. CNP stoichiometry of a lipid-synthesising zooplankton, Calanus finmarchicus, from winter to spring bloom in a sub-Arctic sound

    Science.gov (United States)

    Aubert, A. B.; Svensen, C.; Hessen, D. O.; Tamelander, T.

    2013-02-01

    The aim of this study was to investigate the seasonal stoichiometry of the high-latitude lipid-synthesising copepod Calanus finmarchicus and assess how this would affect dietary demands with season, ontogeny and lipid storage. C:N:P ratios in different stages (adults, copepodite V and IV), in eggs and faecal pellets as well as in bulk food (seston) was analysed in a sub-Arctic Norwegian sound (69° 47'N, 19° 19'E) from late February to mid-May 2009. The period covered the phytoplankton bloom and was divided into four sequences of the bloom based on chl a and seston C:chl a ratio variations. The calculation of the somatic elemental C:N and C:P body ratios (without the lipid storage) indicates that nearly homeostatic control in C. finmarchicus is maintained in somatic tissues within stages, while not if the lipid storage pool is included. Nutrient limitation was assessed calculating threshold elemental ratios based on the somatic body ratios and for different sets of assimilation efficiencies, and indicated a predominant C limitation that may reflect demands for lipid storage. The results suggest that stoichiometric composition and demands in such high-latitude, lipid-storing species strongly depend on stage and season, and the large contribution of storage lipids highlights the need for a two-compartment approach for lipid-synthesising species, with different dietary requirements for somatic growth and for lipid storage.

  10. Temporal changes in community composition of heterotrophic bacteria during in situ iron enrichment in the western subarctic Pacific (SEEDS-II)

    Science.gov (United States)

    Kataoka, Takafumi; Suzuki, Koji; Hayakawa, Maki; Kudo, Isao; Higashi, Seigo; Tsuda, Atsushi

    2009-12-01

    Little is known about the effects of iron enrichment in high-nitrate low-chlorophyll (HNLC) waters on the community composition of heterotrophic bacteria, which are crucial to nutrient recycling and microbial food webs. Using denaturing gradient gel electrophoresis (DGGE) of 16S rDNA fragments, we investigated the heterotrophic eubacterial community composition in surface waters during an in situ iron-enrichment experiment (SEEDS-II) in the western subarctic Pacific in the summer of 2004. DGGE fingerprints representing the community composition of eubacteria differed inside and outside the iron-enriched patch. Sequencing of DGGE bands revealed that at least five phylotypes of α-proteobacteria including Roseobacter, Cytophaga-Flavobacteria- Bacteroides (CFB), γ-proteobacteria, and Actinobacteria occurred in almost all samples from the iron-enriched patch. Diatoms did not bloom during SEEDS-II, but the eubacterial composition in the iron-enriched patch was similar to that in diatom blooms observed previously. Although dissolved organic carbon (DOC) accumulation was not detected in surface waters during SEEDS-II, growth of the Roseobacter clade might have been particularly stimulated after iron additions. Two identified phylotypes of CFB were closely related to the genus Saprospira, whose algicidal activity might degrade the phytoplankton assemblages increased by iron enrichment. These results suggest that the responses of heterotrophic bacteria to iron enrichment could differ among phylotypes during SEEDS-II.

  11. Concentrations and cycling of DMS, DMSP, and DMSO in coastal and offshore waters of the Subarctic Pacific during summer, 2010-2011

    Science.gov (United States)

    Asher, Elizabeth; Dacey, John W.; Ianson, Debby; Peña, Angelica; Tortell, Philippe D.

    2017-04-01

    Concentrations of dimethylsulfide (DMS), measured in the Subarctic Pacific during summer 2010 and 2011, ranged from ˜1 to 40 nM, while dissolved dimethylsulfoxide (DMSO) concentrations (range 13-23 nM) exceeded those of dissolved dimethyl sulfoniopropionate (DMSP) (range 1.3-8.8 nM). Particulate DMSP dominated the reduced sulfur pool, reaching maximum concentrations of 100 nM. Coastal and off shore waters exhibited similar overall DMS concentration ranges, but sea-air DMS fluxes were lower in the oceanic waters due to lower wind speeds. Surface DMS concentrations showed statistically significant correlations with various hydrographic variables including the upwelling intensity (r2 = 0.52, p power at small scales. Stable isotope tracer experiments indicated that the DMSP cleavage pathway always exceeded the DMSO reduction pathway as a DMS source, leading to at least 85% more DMS production in each experiment. Gross DMS production rates were positively correlated with the upwelling intensity, while net rates of DMS production were significantly correlated to surface water DMS concentrations. This latter result suggests that our measurements captured dominant processes driving surface DMS accumulation across a coastal-oceanic gradient.

  12. Innovations in electronic services

    Directory of Open Access Journals (Sweden)

    Dagmara Wach

    2011-12-01

    Full Text Available Summarry Existence in electronic business has become increasingly difficult. High competition and considerable financial resources needed to enter electronic market are the problems of most micro and small sized enterprises, starting or developing their business. Nevertheless, there is a market niche for them, which can ensure success and grant partial financing of the business. This niche are small web projects, providing the customer with personalized service, hitting his tastes and meeting immediate needs. A projects that large websites are unable to perform. Financial sourcing of those projects comes from EU subsidies, in the framework of the Działanie 8.1. PO IG, 2007-2013.

  13. Electron Microscopy.

    Science.gov (United States)

    Beer, Michael

    1980-01-01

    Reviews technical aspects of structure determination in biological electron microscopy (EM). Discusses low dose EM, low temperature microscopy, electron energy loss spectra, determination of mass or molecular weight, and EM of labeled systems. Cites 34 references. (CS)

  14. Electronic Commerce

    OpenAIRE

    Slavko Đerić

    2016-01-01

    Electronic commerce can be defined in different ways. Any definition helps to understand and explain that concept as better as possible.. Electronic commerce is a set of procedures and technologies that automate the tasks of financial transactions using electronic means. Also, according to some authors, electronic commerce is defined as a new concept, which is being developed and which includes process of buying and selling or exchanging products, services or information via computer networks...

  15. Understand electronics

    CERN Document Server

    Bishop, Owen

    2013-01-01

    Understand Electronics provides a readable introduction to the exciting world of electronics for the student or enthusiast with little previous knowledge. The subject is treated with the minimum of mathematics and the book is extensively illustrated.This is an essential guide for the newcomer to electronics, and replaces the author's best-selling Beginner's Guide to Electronics.The step-by-step approach makes this book ideal for introductory courses such as the Intermediate GNVQ.

  16. Vacuum electronics

    CERN Document Server

    Eichmeier, Joseph A

    2008-01-01

    Nineteen experts from the electronics industry, research institutes and universities have joined forces to prepare this book. ""Vacuum Electronics"" covers the electrophysical fundamentals, the present state of the art and applications, as well as the future prospects of microwave tubes and systems, optoelectronics vacuum devices, electron and ion beam devices, light and X-ray emitters, particle accelerators and vacuum interrupters. These topics are supplemented by useful information about the materials and technologies of vacuum electronics and vacuum technology.

  17. Electronic components

    CERN Document Server

    Colwell, Morris A

    1976-01-01

    Electronic Components provides a basic grounding in the practical aspects of using and selecting electronics components. The book describes the basic requirements needed to start practical work on electronic equipment, resistors and potentiometers, capacitance, and inductors and transformers. The text discusses semiconductor devices such as diodes, thyristors and triacs, transistors and heat sinks, logic and linear integrated circuits (I.C.s) and electromechanical devices. Common abbreviations applied to components are provided. Constructors and electronics engineers will find the book useful

  18. ELECTRONIC SIGNATURES

    African Journals Online (AJOL)

    10332324

    'electronic signature' means data attached to, incorporated in, or logically associated with other data and which is intended by the user to serve as a signature;. The suggested new definition for an electronic signature reads as follows: 'electronic signature' means a sound, symbol or process that is (i) uniquely linked to the ...

  19. ELECTRONIC SIGNATURES

    African Journals Online (AJOL)

    10332324

    (a) facilitate ecommerce;2. (b) remove and prevent barriers to electronic communications in South Africa;3. (c) ensure that electronic transactions in the Republic conform to the highest international standards;4. (d) promote the development of electronic transactions services which are responsive to the needs of users and ...

  20. Recycling of electronic scrap

    DEFF Research Database (Denmark)

    Legarth, Jens Brøbech

    This Ph.D. thesis deals with the growingly important field of electronics recycling with special attention to the problem of printed circuit board recycling. A literature survey of contemporary electronics recycling and printed circuit board recycling is presented.Further, an analysis of the role...... of recycling in the modern quest for a sustainable global society is performed, clearly showing that without intensified focus on recycling, the global community cannot hope to reach even the most modest goals for sustainability in resource use. A general method for finding new recycling alternatives...... resource recovery is largest. It is clearly shown with the two printed circuit board scrap cases that the currently used copper recycling scenario is environmentally inferior to the tin and lead primary production scenarios. The method is a novelty, since no-one has previously put forward a method...

  1. Sticker electronics

    KAUST Repository

    Hussain, Muhammad Mustafa

    2017-09-08

    Electronic stickers may be manufactured on flexible substrates (110, 120, 130) as layers and packaged together. The package may then have an adhesive applied to one side to provide capability for sticking the electronic devices to surfaces. The stickers can be wrappable, placed on surfaces, glued on walls or mirrors or wood or stone, and have electronics (112, 122, 132) which may or may not be ultrathin. Packaging for the electronic sticker can use polymer on cellulose manufacturing and/or three dimensional (3-D) printing. The electronic stickers may provide lighting capability, sensing capability, and/or recharging capabilities.

  2. Basic electronics

    CERN Document Server

    Holbrook, Harold D

    1971-01-01

    Basic Electronics is an elementary text designed for basic instruction in electricity and electronics. It gives emphasis on electronic emission and the vacuum tube and shows transistor circuits in parallel with electron tube circuits. This book also demonstrates how the transistor merely replaces the tube, with proper change of circuit constants as required. Many problems are presented at the end of each chapter. This book is comprised of 17 chapters and opens with an overview of electron theory, followed by a discussion on resistance, inductance, and capacitance, along with their effects on t

  3. Electronic Government and Electronic Participation

    NARCIS (Netherlands)

    Tambouris, E.; Scholl, H.J.; Janssen, M.F.W.H.A.; Wimmer, M.A.; Tarabanis, K.; Gascó, M.; Klievink, A.J.; Lindgren, I.; Milano, M.; Panagiotopoulos, P.; Pardo, T.A.; Parycek, P.; Sæbø, O.

    2015-01-01

    Electronic government and electronic participation continue to transform the public sector and society worldwide and are constantly being transformed themselves by emerging information and communication technologies. This book presents papers from the 14th International Federation for Information

  4. Electronic Government and Electronic Participation

    NARCIS (Netherlands)

    Tambouris, E; Scholl, H.J.; Janssen, M.F.W.H.A.; Wimmer, M.A.; Tarabanis, K; Gascó, M; Klievink, A.J.; Lindgren, I; Milano, M; Panagiotopoulos, P; Pardo, T.A.; Parycek, P; Sæbø, Ø

    2016-01-01

    Electronic government and electronic participation continue to transform the public sector and society worldwide and are constantly being transformed themselves by emerging information and communication technologies.This book presents papers from the 14th International Federation for Information

  5. Electron Tree

    DEFF Research Database (Denmark)

    Appelt, Ane L; Rønde, Heidi S

    2013-01-01

    The photo shows a close-up of a Lichtenberg figure – popularly called an “electron tree” – produced in a cylinder of polymethyl methacrylate (PMMA). Electron trees are created by irradiating a suitable insulating material, in this case PMMA, with an intense high energy electron beam. Upon discharge......, during dielectric breakdown in the material, the electrons generate branching chains of fractures on leaving the PMMA, producing the tree pattern seen. To be able to create electron trees with a clinical linear accelerator, one needs to access the primary electron beam used for photon treatments. We...... appropriated a linac that was being decommissioned in our department and dismantled the head to circumvent the target and ion chambers. This is one of 24 electron trees produced before we had to stop the fun and allow the rest of the accelerator to be disassembled....

  6. Dublin Core and Electronic Information Retrieval | Gbaje | Samaru ...

    African Journals Online (AJOL)

    Dublin Core (DC) provides a relatively simple and concise method for resource discovery of composite electronic resources over various networks. This article examines the importance and application of Dublin Core metadata in electronic resource discover over various networks. It is expected that the endorsement of ...

  7. Electronic Recruitment at CERN

    CERN Multimedia

    2004-01-01

    The Human Resources Department switches to electronic recruitment. From now on whenever you are involved in a recruitment action you will receive an e-mail giving you access to a Web folder. Inside you will find a shortlist of applications drawn up by the Human Resources Department. This will allow you to consult the folder, at the same time as everyone else involved in the recruitment process, for the vacancy you are interested in. This new electronic recruitment system, known as e-RT, will be introduced in a presentation given at 10 a.m. on 11 February in the Main Auditorium. Implemented by AIS (Administrative Information Services) and the Human Resources Department, e-RT will cover vacancies open in all of CERN's recruitment programmes. The electronic application system was initially made available to technical students in July 2003. By December it was extended to summer students, fellows, associates and Local Staff. Geraldine Ballet from the Recruitment Service prefers e-RT to mountains of paper! The Hu...

  8. Seasonal calcareous nannoplankton and other biogenic particle fluxes for 1990-2009: twenty-year long records from the central subarctic Pacific Ocean and the Bering Sea

    Science.gov (United States)

    Takahashi, Kozo; Tsutsui, Hideto

    2017-04-01

    Time-series sediment traps were deployed for nearly 20 years (1990-2009) at two long-term locations: Station SA (49°N, 174°W, trap depth 4,800 m, water depth 5,400 m) in the central subarctic Pacific, and Station AB (53.5°N, 177°W, trap depth 3,200 m, water depth 3,800 m) in the southern Bering Sea. Among many biogenic particles, calcareous nannoplankton represented nearly half or more of the entire calcium carbonate fluxes of the regions. Dominant taxa include Coccolithus pelagicus and Emiliania huxleyi. The flux maxima of the former taxon occurred twice a year during June and October-November, whereas that of the latter taxon only occurred primarily once a year in November at both stations, indicating environmental preferences of the taxa. Among many environmental conditions, the fluxes of Emiliania huxleyi showed strong correlations with both water temperatures above 45 m depth and air temperatures (these parameters taken with one-month lag [earlier values] considering sinking time of ca. a month to the respective trap depths). Coccolithus pelagicus, on the other hand, showed lower values in the correlation with temperatures (Tsutsui et al., 2016), indicating that this taxon is somewhat more dependent on other factors such as nutrients compared to those of E. huxleyi. The timings of the seasonal flux maxima of calcareous nannoplankton are quite different from and later than those of other taxonomic groups such as diatoms and silicoflagellates. The primary seasonal flux maxima of diatoms and silicoflagellates, for example, occurred in May, a month earlier than the June maximum of C. pelagicus, and secondary seasonal flux maxima occurred in August, 2-3 months earlier than those of calcareous nannoplankton at both stations, based on 8 year flux records for diatoms (Onodera and Takahashi, 2009) and 4 year records for silicoflagellates (Onodera and Takahashi, 2012). By examining seasonal changes of nitrate and phosphate concentrations above 50 m depth from ERDDAP

  9. Impact of Euro-Canadian agrarian practices: in search of sustainable import-substitution strategies to enhance food security in subarctic Ontario, Canada.

    Science.gov (United States)

    Spiegelaar, Nicole F; Tsuji, Leonard J S

    2013-01-01

    In Canada, food insecurity exists among Aboriginal (Inuit, Metis and First Nations) people living in remote northern communities, in part, because of their reliance on the industrialized, import-based food system. Local food production as a substitute to imports would be an adaptive response, but enhancement of food security via food localization requires reflection on previous failings of conventional agricultural strategies so that informed decisions can be made. In light of potential reintroduction of local food production in remote First Nations communities, we investigated the cultural, social and ecological effects of a 20th century, Euro-Canadian agrarian settlement on the food system of a subarctic First Nation; this will act as the first step in developing a more sustainable local food program and enhancing food security in this community. To investigate the socio-cultural impacts of the Euro-Canadian agrarian initiative on the food system of Fort Albany First Nation, purposive, semi-directive interviews were conducted with elders and other knowledgeable community members. Interview data were placed into themes using inductive analyses. To determine the biophysical impact of the agrarian initiative, soil samples were taken from one site within the cultivated area and from one site in an undisturbed forest area. Soil properties associated with agricultural use and productivity were assessed. To compare the means of a given soil property between the sites, one-tailed t-tests were employed. Vegetative analysis was conducted in both sites to assess disturbance. According to the interviewees, prior to the agrarian initiative, First Nation families harvested wild game and fish, and gathered berries as well as other forms of vegetation for sustenance. With the introduction of the residential school and agrarian initiative, traditional food practices were deemed inadequate, families were forced to work and live in the settlement (becoming less reliant on

  10. Electronic Commerce

    Directory of Open Access Journals (Sweden)

    Slavko Đerić

    2016-12-01

    Full Text Available Electronic commerce can be defined in different ways. Any definition helps to understand and explain that concept as better as possible.. Electronic commerce is a set of procedures and technologies that automate the tasks of financial transactions using electronic means. Also, according to some authors, electronic commerce is defined as a new concept, which is being developed and which includes process of buying and selling or exchanging products, services or information via computer networks, including the Internet. Electronic commerce is not limited just to buying and selling, but it also includes all pre-sales and after-sales ongoing activities along the supply chain. Introducing electronic commerce, using the Internet and Web services in business, realizes the way to a completely new type of economy - internet economy.

  11. Summertime measurements of selected nonmethane hydrocarbons in the Arctic and sub-Arctic during the 1988 Arctic Boundary Layer Expedition (ABLE 3A)

    Science.gov (United States)

    Blake, Donald R.; Hurst, Dale F.; Smith, Tyrrel W.; Whipple, Wayne J.; Chen, Tai-Yih; Blake, Nicola J.; Rowland, F. Sherwood

    1992-10-01

    Approximately 1000 whole air samples were collected and assayed for selected C2-C5 hydrocarbons during the 6-week Arctic Boundary Layer Expedition (ABLE 3A). Transit flights enabled latitudinal (40°N to 83°N) and longitudinal (70°W to 155°W) profiles to be obtained for altitudes between 4000 and 6000 m yielding summertime background mixing ratios for ethane, ethyne, propane and n-butane of 1050±200, 100±40, 120±80 and 10±8 pptv, respectively. Drilling associated with oil exploration in the Alaskan North Slope area is suggested to be a probable source of the enhanced levels of alkanes observed in the Arctic region within a radius in excess of 300 km from Prudhoe Bay, Alaska. A significant number of pollution plumes were encountered which could be attributed to wildfires. Factors describing the emissions caused by biomass burning relative to ethane for ethyne (0.40) and propane (0.08) were determined. An increase of hydrocarbon mixing ratios with altitude was observed during all but two of the missions. Therefore, the Arctic and sub-Arctic are significantly influenced by the long-range transport of pollutants from nonlocal sources. A single vertical profile made in the vicinity of Wallops Island, Virginia, revealed elevated levels of isoprene, numerous hydrocarbons of the types associated with the leakage of natural gas and fossil fuel combustion, and substantial concentrations of nitrogen oxides and ozone. This implies that long-range transport of various gases from urban areas, combined with local biogenic emissions of isoprene, are significant sources of regional tropospheric ozone.

  12. Foliar pH as a new plant trait: can it explain variation in foliar chemistry and carbon cycling processes among subarctic plant species and types?

    Science.gov (United States)

    Cornelissen, J H C; Quested, H M; van Logtestijn, R S P; Pérez-Harguindeguy, N; Gwynn-Jones, D; Díaz, S; Callaghan, T V; Press, M C; Aerts, R

    2006-03-01

    Plant traits have become popular as predictors of interspecific variation in important ecosystem properties and processes. Here we introduce foliar pH as a possible new plant trait, and tested whether (1) green leaf pH or leaf litter pH correlates with biochemical and structural foliar traits that are linked to biogeochemical cycling; (2) there is consistent variation in green leaf pH or leaf litter pH among plant types as defined by nutrient uptake mode and higher taxonomy; (3) green leaf pH can predict a significant proportion of variation in leaf digestibility among plant species and types; (4) leaf litter pH can predict a significant proportion of variation in leaf litter decomposability among plant species and types. We found some evidence in support of all four hypotheses for a wide range of species in a subarctic flora, although cryptogams (fern allies and a moss) tended to weaken the patterns by showing relatively poor leaf digestibility or litter decomposability at a given pH. Among seed plant species, green leaf pH itself explained only up to a third of the interspecific variation in leaf digestibility and leaf litter up to a quarter of the interspecific variation in leaf litter decomposability. However, foliar pH substantially improved the power of foliar lignin and/or cellulose concentrations as predictors of these processes when added to regression models as a second variable. When species were aggregated into plant types as defined by higher taxonomy and nutrient uptake mode, green-specific leaf area was a more powerful predictor of digestibility or decomposability than any of the biochemical traits including pH. The usefulness of foliar pH as a new predictive trait, whether or not in combination with other traits, remains to be tested across more plant species, types and biomes, and also in relation to other plant or ecosystem traits and processes.

  13. Twenty-two years of warming, fertilisation and shading of subarctic heath shrubs promote secondary growth and plasticity but not primary growth.

    Directory of Open Access Journals (Sweden)

    Matteo Campioli

    Full Text Available Most manipulation experiments simulating global change in tundra were short-term or did not measure plant growth directly. Here, we assessed the growth of three shrubs (Cassiope tetragona, Empetrum hermaphroditum and Betula nana at a subarctic heath in Abisko (Northern Sweden after 22 years of warming (passive greenhouses, fertilisation (nutrients addition and shading (hessian fabric, and compare this to observations from the first decade of treatment. We assessed the growth rate of current-year leaves and apical stem (primary growth and cambial growth (secondary growth, and integrated growth rates with morphological measurements and species coverage. Primary- and total growth of Cassiope and Empetrum were unaffected by manipulations, whereas growth was substantially reduced under fertilisation and shading (but not warming for Betula. Overall, shrub height and length tended to increase under fertilisation and warming, whereas branching increased mostly in shaded Cassiope. Morphological changes were coupled to increased secondary growth under fertilisation. The species coverage showed a remarkable increase in graminoids in fertilised plots. Shrub response to fertilisation was positive in the short-term but changed over time, likely because of an increased competition with graminoids. More erected postures and large, canopies (requiring enhanced secondary growth for stem reinforcement likely compensated for the increased light competition in Empetrum and Cassiope but did not avoid growth reduction in the shade intolerant Betula. The impact of warming and shading on shrub growth was more conservative. The lack of growth enhancement under warming suggests the absence of long-term acclimation for processes limiting biomass production. The lack of negative effects of shading on Cassiope was linked to morphological changes increasing the photosynthetic surface. Overall, tundra shrubs showed developmental plasticity over the longer term. However, such

  14. Combined effects of environmental disturbance and climate warming on insect herbivory in mountain birch in subarctic forests: Results of 26-year monitoring.

    Science.gov (United States)

    Kozlov, M V; Zverev, V; Zvereva, E L

    2017-12-01

    Both pollution and climate affect insect-plant interactions, but the combined effects of these two abiotic drivers of global change on insect herbivory remain almost unexplored. From 1991 to 2016, we monitored the population densities of 25 species or species groups of insects feeding on mountain birch (Betula pubescens ssp. czerepanovii) in 29 sites and recorded leaf damage by insects in 21 sites in subarctic forests around the nickel-copper smelter at Monchegorsk, north-western Russia. The leaf-eating insects demonstrated variable, and sometimes opposite, responses to pollution-induced forest disturbance and to climate variations. Consequently, we did not discover any general trend in herbivory along the disturbance gradient. Densities of eight species/species groups correlated with environmental disturbance, but these correlations weakened from 1991 to 2016, presumably due to the fivefold decrease in emissions of sulphur dioxide and heavy metals from the smelter. The densities of externally feeding defoliators decreased from 1991 to 2016 and the densities of leafminers increased, while the leaf roller densities remained unchanged. Consequently, no overall temporal trend in the abundance of birch-feeding insects emerged despite a 2-3°C elevation in spring temperatures. Damage to birch leaves by insects decreased during the observation period in heavily disturbed forests, did not change in moderately disturbed forests and tended to increase in pristine forests. The temporal stability of insect-plant interactions, quantified by the inverse of the coefficient of among-year variations of herbivore population densities and of birch foliar damage, showed a negative correlation with forest disturbance. We conclude that climate differently affects insect herbivory in heavily stressed versus pristine forests, and that herbivorous insects demonstrate diverse responses to environmental disturbance and climate variations. This diversity of responses, in combination with the

  15. Phenological diversity in the interactions between winter moth (Operophtera brumata) larvae and parasitoid wasps in sub-arctic mountain birch forest.

    Science.gov (United States)

    Vindstad, O P L; Hagen, S B; Jepsen, J U; Kapari, L; Schott, T; Ims, R A

    2011-12-01

    Population cycles of the winter moth (Operophtera brumata) in sub-arctic coastal birch forests show high spatiotemporal variation in amplitude. Peak larval densities range from levels causing little foliage damage to outbreaks causing spatially extensive defoliation. Moreover, outbreaks typically occur at or near the altitudinal treeline. It has been hypothesized that spatiotemporal variation in O. brumata cycle amplitude results from climate-induced variation in the degree of phenological matching between trophic levels, possibly between moth larvae and parasitoids. The likelihood of mismatching phenologies between larvae and parasitoids is expected to depend on how specialized parasitoids are, both as individual species and as a guild, to attacking specific larval developmental stages (i.e. instars). To investigate the larval instar-specificity of parasitoids, we studied the timing of parasitoid attacks relative to larval phenology. We employed an observational study design, with sequential sampling over the larval period, along an altitudinal gradient harbouring a pronounced treeline outbreak of O. brumata. Within the larval parasitoid guild, containing seven species groups, the timing of attack by different groups followed a successional sequence throughout the moth's larval period and each group attacked 1-2 instars. Such phenological diversity within parasitoid guilds may lower the likelihood of climate-induced trophic mismatches between victim populations and many/all of their enemies. Parasitism rates declined with increasing altitude for most parasitoid groups and for the parasitoid guild as a whole. However, the observed spatiotemporal parasitism patterns provided no clear evidence for or against altitudinal mismatch between larval and parasitoid phenology.

  16. Micropower electronics

    CERN Document Server

    Keonjian, Edward

    1964-01-01

    Micropower Electronics deals with the operation of modern electronic equipment at micropower levels and the problems associated with micropower electronics. Topics covered include the relations between minimum required power density and frequency response for semiconductor triode amplifiers; physical realization of digital logic circuits; micropower microelectronic subsystems; and metal-oxide-semiconductor field-effect devices for micropower logic circuitry. This book is comprised of 10 chapters and begins with an analysis of fundamental relationships and basic requirements pertinent to the ph

  17. Microfluidic electronics.

    Science.gov (United States)

    Cheng, Shi; Wu, Zhigang

    2012-08-21

    Microfluidics, a field that has been well-established for several decades, has seen extensive applications in the areas of biology, chemistry, and medicine. However, it might be very hard to imagine how such soft microfluidic devices would be used in other areas, such as electronics, in which stiff, solid metals, insulators, and semiconductors have previously dominated. Very recently, things have radically changed. Taking advantage of native properties of microfluidics, advances in microfluidics-based electronics have shown great potential in numerous new appealing applications, e.g. bio-inspired devices, body-worn healthcare and medical sensing systems, and ergonomic units, in which conventional rigid, bulky electronics are facing insurmountable obstacles to fulfil the demand on comfortable user experience. Not only would the birth of microfluidic electronics contribute to both the microfluidics and electronics fields, but it may also shape the future of our daily life. Nevertheless, microfluidic electronics are still at a very early stage, and significant efforts in research and development are needed to advance this emerging field. The intention of this article is to review recent research outcomes in the field of microfluidic electronics, and address current technical challenges and issues. The outlook of future development in microfluidic electronic devices and systems, as well as new fabrication techniques, is also discussed. Moreover, the authors would like to inspire both the microfluidics and electronics communities to further exploit this newly-established field.

  18. Electron Bifurcation

    Energy Technology Data Exchange (ETDEWEB)

    Peters, John W.; Miller, Anne-Frances; Jones, Anne K.; King, Paul W.; Adams, Michael W. W.

    2016-04-01

    Electron bifurcation is the recently recognized third mechanism of biological energy conservation. It simultaneously couples exergonic and endergonic oxidation-reduction reactions to circumvent thermodynamic barriers and minimize free energy loss. Little is known about the details of how electron bifurcating enzymes function, but specifics are beginning to emerge for several bifurcating enzymes. To date, those characterized contain a collection of redox cofactors including flavins and iron-sulfur clusters. Here we discuss the current understanding of bifurcating enzymes and the mechanistic features required to reversibly partition multiple electrons from a single redox site into exergonic and endergonic electron transfer paths.

  19. Polymer electronics

    CERN Document Server

    Hsin-Fei, Meng

    2013-01-01

    Polymer semiconductor is the only semiconductor that can be processed in solution. Electronics made by these flexible materials have many advantages such as large-area solution process, low cost, and high performance. Researchers and companies are increasingly dedicating time and money in polymer electronics. This book focuses on the fundamental materials and device physics of polymer electronics. It describes polymer light-emitting diodes, polymer field-effect transistors, organic vertical transistors, polymer solar cells, and many applications based on polymer electronics. The book also disc

  20. Electron holography

    CERN Document Server

    Tonomura, Akira

    1993-01-01

    Holography was devised for breaking through the resolution limit of electron microscopes The advent of a "coherent" field emission electron beam has enabled the use of Electron Holography in various areas of magnetic domain structures observation, fluxon observation in superconductors, and fundamental experiments in physics which have been inaccessible using other techniques After examining the fundamentals of electron holography and its applications to the afore mentioned fields, a detailed discussion of the Aharonov-Bohm effect and the related experiments is presented Many photographs and illustrations are included to elucidate the text