ERIC Education Library's New Look Debuts Online

ERIC Educational Resources Information Center

Viadero, Debra

2004-01-01

This article reports on the newly revamped version of the Educational Resources Information Center (ERIC), the nation's largest electronic education library. ERIC made its debut last September with promises of more offerings to come from the federal project. In the move to upgrade and streamline ERIC, the Department of Education shut down the 16…

So You Need Information About Mexican Americans? Let ERIC Help!

ERIC Educational Resources Information Center

Quezada, Manuela L., Comp.; Chabran, Richard, Comp.

The guide is intended to explain and demonstrate by example how to use the Educational Resources Information Center (ERIC) system, especially to find information pertaining to Mexican Americans. An overview of ERIC and ERIC/CRESS (ERIC Clearinghouse on Rural Education and Small Schools) is given, noting definitions, potential users, types of…

Evolution of the Jan Mayen Ridge - new geochemical and geophysical data from the Jan Mayen Fracture Zone

NASA Astrophysics Data System (ADS)

Slama, J.; Pedersen, R. B.; Kosler, J.; Kandilarov, A.; Hendriks, B. W. H.

2009-04-01

Geochronologic and geochemical data derived from sea-floor samples dredged from the Jan Mayen Fracture Zone together with seismic data provide new insight into the tectonomagmatic evolution of the Jan Mayen Ridge. Based on the seismic data, the Jan Mayen Ridge is believed to represent an off-rifted fragment of East Greenland continental lithosphere that since early Miocene has drifted 400 km into the North Atlantic as a result of sea-floor spreading along the Kolbeinsey Ridge. At present the Jan Mayen Ridge is uniquely located at the Mid-Atlantic Ridge north of Iceland. During the recent G.O.SARS research cruises a suite of volcanic rocks, as well as sandstones and conglomerates that are predominantly made up of volcaniclastic material were recovered from the southern escarpment of Jan Mayen Fracture Zone east of Jan Mayen. The conglomerates contain carbonate shell fragments that yielded 87Sr/86Sr age of ca. 32 Ma, which probably reflects the time of deposition of these volcano-sedimentary rocks. U-Pb ages of detrital zircon from the samples show age distribution consistent with an East Greenland source region characterized by a wide age pattern with significant Archaean and Early Proterozoic component. A population of angular zircons provides the youngest ages around 30 Ma, which are consistent with the Sr-age data from the shell fragment. These young zircons are most likely derived from the local volcanic material and do accordingly date the volcanic activity. Chemical analyses of individual volcanic clasts in the conglomerates show that they belong to the trachytic suite, and correspond mainly to hawaiites and trachyandesites. They are geochemically very similar to the recent volcanic rocks of the Jan Mayen Island. The maximum age of some of the volcanic clasts obtained by Ar-Ar whole-rock dating is consistent with the age of the youngest detrital zircons and with the Sr-age of the shell fragment. The new data suggest that the alkaline volcanism in the Jan Mayen

Perspectives on ERIC and Adult Education

ERIC Educational Resources Information Center

Imel, Susan

2016-01-01

Susan Imel is retired from Ohio State University. From December 1981 until December 2003, she was the Adult Education Specialist at the ERIC Clearinghouse on Adult, Career, and Vocational Education and Director from 1987 through 2003. This essay begins with a brief overview of the ERIC system including goals for the clearinghouses, followed by a…

Document Preparation (for Filming). ERIC Processing Manual, Appendix B.

ERIC Educational Resources Information Center

Brandhorst, Ted, Ed.; And Others

The technical report or "fugitive" literature collected by ERIC is produced using a wide variety of printing techniques, many formats, and variable degrees of quality control. Since the documents processed by ERIC go on to be microfilmed and reproduced in microfiche and paper copy for sale to users, it is essential that the ERIC document…

Archean Microbial Mat Communities

NASA Astrophysics Data System (ADS)

Tice, Michael M.; Thornton, Daniel C. O.; Pope, Michael C.; Olszewski, Thomas D.; Gong, Jian

2011-05-01

Much of the Archean record of microbial communities consists of fossil mats and stromatolites. Critical physical emergent properties governing the evolution of large-scale (centimeters to meters) topographic relief on the mat landscape are (a) mat surface roughness relative to the laminar sublayer and (b) cohesion. These properties can be estimated for fossil samples under many circumstances. A preliminary analysis of Archean mat cohesion suggests that mats growing in shallow marine environments from throughout this time had cohesions similar to those of modern shallow marine mats. There may have been a significant increase in mat strength at the end of the Archean.

Design of ERIC Usage Studies. Volume II.

ERIC Educational Resources Information Center

ERIC Clearinghouse on Information Resources, Syracuse, NY.

This document contains reports examining research designs for Educational Resources Information Center (ERIC) usage studies at three levels: (1) system operations; (2) subscribers to the services provided; and (3) the ultimate "end-users" of the service. The first level report, which addresses ERIC as an information network, proposes two…

Summary of the Presentation "ERIC: How Can It Help Me?"

ERIC Educational Resources Information Center

Eddy, Peter A.

This is a summary of a presentation on the Educational Resources Information Center (ERIC). The presentation provided information on how the user can gain access to the ERIC microfiche collection at libraries throughout the United States, and to reprints through the ERIC Document Reproduction Service (EDRS). Use of the Thesaurus of ERIC…

Distributing the ERIC Database on SilverPlatter Compact Disc--A Brief Case History.

ERIC Educational Resources Information Center

Brandhorst, Ted

This description of the development of the Education Resources Information Center (ERIC) compact disc by two companies, SilverPlatter and ORI, Inc., provides background information on ERIC and the ERIC database, discusses reasons for choosing to put the ERIC database on compact discs, and describes the formulation of an ERIC CD-ROM team as part of…

Handling and Shipping. ERIC Processing Manual, Section IV.

ERIC Educational Resources Information Center

Brandhorst, Ted, Ed.; And Others

Rules and guidelines are provided for the handling and shipping of document and journal article information intended for announcement in ERIC's abstract journals "Resources in Education" and "Current Index to Journals in Education." The handling and shipping involved takes place between the ERIC Facility and the ERIC…

New Access Points to ERIC--CD-ROM Versions. ERIC Digest.

ERIC Educational Resources Information Center

McLaughlin, Pamela W.

This digest reviews three CD-ROM (compact disc-read only memory) versions of the ERIC (Educational Resources Information Center) database currently being delivered or tested and provides information for comparison. However, no attempt is made to recommend any one product. The advantages and disadvantages of the acquisition of CD-ROM databases are…

Skyview Foods: Eric's Real Dilemma with Channel Partners

ERIC Educational Resources Information Center

Castleberry, Stephen B.

2011-01-01

As a marketing analyst, Eric is faced with several ethical dilemmas. When asked to engage in unethical and illegal behavior, Eric must decide whether to obey his boss and fudge the numbers (the counts of product purchased in order to get reimbursed more from the manufacturer during special sales) or take the ethical route. The case consists of two…

Following the Path Blazed by Jan Hall

NASA Astrophysics Data System (ADS)

Hollberg, Leo

It was a great pleasure to gather with friends in August 2004 for the symposium honoring Jan Hall and celebrating his 70th birthday, and this book provides a unique opportunity to record some words commemorating Jan's incredible contributions to science and to our lives. At best, my recollections are a faded, myopic snapshot of some events that come to mind after many years of association with Jan. Reflecting on the years that have passed since I first entered Jan's lab, I see that many things have changed, technology has advanced (mostly for the better), the world has evolved in dramatic and significant ways (some good and some not), and I have grown older (but unfortunately not wiser as one might have hoped). Nonetheless, after many years, I find myself still following the path pointed out by Jan's visions and investing most of my productive time and energy working as a scientist trying to get atoms, lasers, electronics, (and the institutional bureaucracy that comes along with them) to work in some kind of harmony…

ERIC Documents on Foreign Language Teaching and Linguistics: List No. 17. CAL-ERIC/CLL Series on Languages and Linguistics, No. 54.

ERIC Educational Resources Information Center

Eddy, Peter A., Comp.; McLane, Kathleen, Comp.

1977-01-01

This is the seventeenth in a series of catalogues of documents in the ERIC system that are of interest to teachers and researchers in foreign languages and linguistics. The documents cited in the present list appeared in the monthly ERIC abstract journal "Resources in Education" from January through June, 1976. The list is compiled from all of the…

ERIC Documents on Foreign Language Teaching and Linguistics: List Number 16. CAL-ERIC/CLL Series on Languages and Linguistics, Number 42.

ERIC Educational Resources Information Center

Eddy, Peter A., Comp.; McLane, Kathleen, Comp.

1976-01-01

This is the sixteenth in a series of catalogues of documents of interest to teachers and researchers in foreign languages and linguistics that have been processed into the ERIC system. The documents cited in the present list appeared in the monthly ERIC abstract journal "Resources in Education" (RIE) from July through December 1975. The list is…

ERIC Documents on Foreign Language Teaching and Linguistics: List No. 18. CAL-ERIC/CLL Series on Languages and Linguistics, No. 57.

ERIC Educational Resources Information Center

McLane, Kathleen, Comp.; Omaggio, Alice, Comp.

1977-01-01

This is the eighteenth in a series of catalogues of documents in the ERIC system that are of interest to teachers and researchers in foreign languages and linguistics. The documents cited in the present list appeared in the monthly ERIC abstract journal "Resources in Education" (RIE) from July through December 1976. The list is compiled from all…

How Many People Search the ERIC Database Each Day?

ERIC Educational Resources Information Center

Rudner, Lawrence

This study estimated the number of people searching the ERIC database each day. The Educational Resources Information Center (ERIC) is a national information system designed to provide ready access to an extensive body of education-related literature. Federal funds traditionally have paid for the development of the database, but not the…

MatLab Script and Functional Programming

NASA Technical Reports Server (NTRS)

Shaykhian, Gholam Ali

2007-01-01

MatLab Script and Functional Programming: MatLab is one of the most widely used very high level programming languages for scientific and engineering computations. It is very user-friendly and needs practically no formal programming knowledge. Presented here are MatLab programming aspects and not just the MatLab commands for scientists and engineers who do not have formal programming training and also have no significant time to spare for learning programming to solve their real world problems. Specifically provided are programs for visualization. The MatLab seminar covers the functional and script programming aspect of MatLab language. Specific expectations are: a) Recognize MatLab commands, script and function. b) Create, and run a MatLab function. c) Read, recognize, and describe MatLab syntax. d) Recognize decisions, loops and matrix operators. e) Evaluate scope among multiple files, and multiple functions within a file. f) Declare, define and use scalar variables, vectors and matrices.

Foam-mat drying technology: A review.

PubMed

Hardy, Z; Jideani, V A

2017-08-13

This article reviews various aspects of foam-mat drying such as foam-mat drying processing technique, main additives used for foam-mat drying, foam-mat drying of liquid and solid foods, quality characteristics of foam-mat dried foods, and economic and technical benefits for employing foam-mat drying. Foam-mat drying process is an alternative method that allows the removal of water from liquid materials and pureed materials. In this drying process, a liquid material is converted into foam that is stable by being whipped after adding an edible foaming agent. The stable foam is then spread out in sheet or mat and dried by using hot air (40-90°C) at atmospheric pressure. Methyl cellulose (0.25-2%), egg white (3-20%), maltodextrin (0.5-05%), and gum Arabic (2-9%) are the commonly utilized additives for the foam-mat drying process at the given range, either combined together for their effectiveness or individual effect. The foam-mat drying process is suitable for heat sensitive, viscous, and sticky products that cannot be dried using other forms of drying methods such as spray drying because of the state of product. More interest has developed for foam-mat drying because of the simplicity, cost effectiveness, high speed drying, and improved product quality it provides.

MatMRI and MatHIFU: software toolboxes for real-time monitoring and control of MR-guided HIFU

PubMed Central

2013-01-01

Background The availability of open and versatile software tools is a key feature to facilitate pre-clinical research for magnetic resonance imaging (MRI) and magnetic resonance-guided high-intensity focused ultrasound (MR-HIFU) and expedite clinical translation of diagnostic and therapeutic medical applications. In the present study, two customizable software tools that were developed at the Thunder Bay Regional Research Institute are presented for use with both MRI and MR-HIFU. Both tools operate in a MATLAB®; environment. The first tool is named MatMRI and enables real-time, dynamic acquisition of MR images with a Philips MRI scanner. The second tool is named MatHIFU and enables the execution and dynamic modification of user-defined treatment protocols with the Philips Sonalleve MR-HIFU therapy system to perform ultrasound exposures in MR-HIFU therapy applications. Methods MatMRI requires four basic steps: initiate communication, subscribe to MRI data, query for new images, and unsubscribe. MatMRI can also pause/resume the imaging and perform real-time updates of the location and orientation of images. MatHIFU requires four basic steps: initiate communication, prepare treatment protocol, and execute treatment protocol. MatHIFU can monitor the state of execution and, if required, modify the protocol in real time. Results Four applications were developed to showcase the capabilities of MatMRI and MatHIFU to perform pre-clinical research. Firstly, MatMRI was integrated with an existing small animal MR-HIFU system (FUS Instruments, Toronto, Ontario, Canada) to provide real-time temperature measurements. Secondly, MatMRI was used to perform T2-based MR thermometry in the bone marrow. Thirdly, MatHIFU was used to automate acoustic hydrophone measurements on a per-element basis of the 256-element transducer of the Sonalleve system. Finally, MatMRI and MatHIFU were combined to produce and image a heating pattern that recreates the word ‘HIFU’ in a tissue

Indexing and Retrieval in ERIC: The 20th Year.

ERIC Educational Resources Information Center

Barnett, Lynn

This brief review of the Educational Resources Information Center (ERIC) system is intended to make users more aware of (1) the system as a whole, (2) the process of indexing educational literature for the database, and (3) the role of the Thesaurus of ERIC Descriptors in the overall information dissemination process. An overview of the ERIC…

La Base de Donnees ERIC: Evaluation de Son Utilisation et Discussion des Choix du Systeme (The ERIC Database: An Evaluation of Its Use and a Discussion of the System Model).

ERIC Educational Resources Information Center

Malrieu, Denise

1983-01-01

This overview of the ERIC system begins with a brief history of the system; a description of the types and numbers of materials contained in the database; sources of types of information for educators that are not processed by ERIC; and the various publications and reference materials produced by and for the system. The analysis of ERIC usage in…

Database Changes (Post-Publication). ERIC Processing Manual, Section X.

ERIC Educational Resources Information Center

Brandhorst, Ted, Ed.

The purpose of this section is to specify the procedure for making changes to the ERIC database after the data involved have been announced in the abstract journals RIE or CIJE. As a matter of general ERIC policy, a document or journal article is not re-announced or re-entered into the database as a new accession for the purpose of accomplishing a…

Positive Discipline. ERIC Digest.

ERIC Educational Resources Information Center

ERIC Clearinghouse on Elementary and Early Childhood Education, Urbana, IL.

This ERIC Digest suggests methods and language that can be used in handling difficult, but common, situations involving young children. Discussion focuses on: (1) 12 methods of discipline that promote self-worth; (2) the process of creating a positive climate that promotes self-discipline; (3) harmful and negative disciplinary methods; and (4)…

ERIC/RCS Report: Animals in Literature.

ERIC Educational Resources Information Center

O'Donnell, Holly

1980-01-01

Notes children's continuing interest in animal stories, examines some characteristics of animal stories as discussed in ERIC documents, and suggests booklists that include listings of animal stories. (ET)

OBITUARY: Professor Jan Evetts in memoriam

NASA Astrophysics Data System (ADS)

Dew-Hughes, David; Campbell, Archie; Glowacki, Bartek

2005-11-01

It is with great sadness that we report the death of Jan Evetts, who lost his second battle with cancer on 18 August 2005. In 1988 he was appointed Founding Editor of this journal where his leadership created the foundation upon which its success rests today. He made an outstanding series of contributions to the science of superconductivity and to the understanding of superconducting materials, and was an indefatigable champion of the development of applications of superconductivity. The loss to the scientific community is incalculable, as is attested by the many communications received from colleagues throughout the world. Professor Jan Edgar Evetts (1939-2005) Professor Jan Edgar Evetts (1939-2005) Jan was born on 31 March 1939, and attended the Dragon School in Oxford, and later Haileybury. He was awarded an exhibition to read Natural Sciences at Pembroke College, Cambridge in 1958 and took his BA degree in 1961. He then undertook a Certificate of Postgraduate Study in Physics under the supervision of Professor Neville Mott. He was the first student to undertake this newly-instituted course; the title of his thesis was `The Resistance of Transition Metals'. In 1962 he joined David Dew-Hughes' embryonic superconducting materials research group, along with Archie Campbell and Anant Narlikar. In fact it was Jan's enthusiasm for the proposed course of research that helped convince David that he should follow Professor Alan Cottrell's suggestion to apply metallurgical methodology to the study of the factors that controlled critical current density in the type II superconductors that were then under development for applications in magnets. Competing theories for the critical current density at that time were fine filaments or `Mendelssohn Sponge' versus the pinning of Abrikosov quantized vortices. The results of the group's work, to which Jan made a major contribution, came down heavily in favour of the latter theory. Jan's outstanding characteristic was his

Introduction. ERIC Processing Manual, Section I.

ERIC Educational Resources Information Center

Brandhorst, Ted, Ed.

This document describes the major organizational components of the Educational Resources Information Center (ERIC) system, the interactions between those components, and the major products and services provided by those components. (WTB)

ERIC Annual Report, 2002: Summarizing the Recent Accomplishments of the Educational Resources Information Center.

ERIC Educational Resources Information Center

Smarte, Lynn; Starcher, Heather

This ERIC Annual Report presents both accomplishments and historical perspectives, as 2001 marks 35 years of ERIC service in delivering educational research and information to the public. This annual report describes the developments in the database of educational literature, the growing variety of ERIC Web-based products and user services, and…

ERIC Annual Report, 1999: Summarizing the Recent Accomplishments of the Educational Resources Information Center.

ERIC Educational Resources Information Center

Smarte, Lynn

This 1999 annual report, summarizing the accomplishments of the Educational Resources Information System (ERIC) system in 1998, begins with a section that highlights progress towards meeting goals, as well as selected statistics. The second section, comprising the bulk of the report, provides an overview of ERIC, including the ERIC database, user…

ERIC Annual Report, 2000: Summarizing the Recent Accomplishments of the Educational Resources Information Center.

ERIC Educational Resources Information Center

Smarte, Lynn

This 2000 annual report, summarizing the accomplishments of the Educational Resources Information Center (ERIC) system in 1999, begins with a section that highlights progress towards meeting goals, as well as selected statistics. The second section, comprising the bulk of the report, provides an overview of ERIC, including the ERIC database, user…

Aerobic sulfate reduction in microbial mats

NASA Technical Reports Server (NTRS)

Canfield, Donald E.; Des Marais, David J.

1991-01-01

Measurements of bacterial sulfate reduction and dissolved oxygen (O2) in hypersaline bacterial mats from Baja California, Mexico, revealed that sulfate reduction occurred consistently within the well-oxygenated photosynthetic zone of the mats. This evidence that dissimilatory sulfate reduction can occur in the presence of O2 challenges the conventional view that sulfate reduction is a strictly anaerobic process. At constant temperature, the rates of sulfate reduction in oxygenated mats during daytime were similar to rates in anoxic mats at night: thus, during a 24-hour cycle, variations in light and O2 have little effect on rates of sulfate reduction in these mats.

Flow-induced Development of Unicellular Cyanobacterial Mats

NASA Astrophysics Data System (ADS)

Gong, J.; Tice, M. M.

2011-12-01

Microbial mats/biofilms are abundant microbial growth structures throughout the history of life on Earth. Understanding the mechanisms for their morphogenesis and interactions with physical sedimentary forces are important topics that allow deeper understanding of related records. When subjected to hydrodynamic influences, mats are known to vary in morphology and structure in response to fluid shear, yet mechanistically, the underlying cellular architecture due to interactions with flow remain unexplained. Moreover, mats are found to emerge larger scale roughness elements and modified cohesive strength growing under flow. It is a mystery how and why these mat-community-level features are linked in association with modified boundary layers at the mats surface. We examined unicellular cyanobacterium Synechocystis sp. PCC 6803 in a circular flow bioreactor designed to maintain a fixed set of hydrodynamic conditions. The use of monoculture strains and unidirectional currents, while not replicating natural mat systems (almost certainly multi-species and often multi-directional currents under complex wind or tidal wave actions), helps to simplify these systems and allows for specific testing of hypotheses regarding how mats evolve distinctive morphologies induced by flow. The unique design of the reactor also makes measurements such as critical erosional shear stress of the mats possible, in addition to microscopic, macroscopic imaging and weeks of continuous mats growth monitoring. We report the finding that linear chains, filament-like cell groups were present from unicellular cyanobacterial mats growing under flow (~1-5 cm/s) and these structures are organized within ~1-3mm size streamers and ~0.5-1mm size nodular macrostructures. Ultra-small, sub-micron thick EPS strings are observed under TEM and are likely the cohesive architectural elements in mats across different fluid regimes. Mat cohesion generally grows with and adapts to increasing flow shear stress within

ERIC Processing Manual. Rules and Guidelines for the Acquisition, Selection, and Technical Processing of Documents and Journal Articles by the Various Components of the ERIC Network.

ERIC Educational Resources Information Center

Brandhorst, Ted, Ed.; And Others

This loose-leaf manual provides the detailed rules, guidelines, and examples to be used by the components of the Educational Resources Information Center (ERIC) Network in acquiring and selecting documents and in processing them (i.e., cataloging, indexing, abstracting) for input to the ERIC computer system and subsequent announcement in…

Editorial: A dedication to Professor Jan Evetts

NASA Astrophysics Data System (ADS)

Weber, Harald; Dew-Hughes, David; Campbell, Archie; Barber, Zoe; Somekh, Rob; Glowacki, Bartek

2006-03-01

A few days before the beginning of the 7th European Conference on Applied Superconductivity we learned that Professor Jan Evetts, a pioneer of superconductor research, a brilliant scientist, a wonderful person and a great personal friend, had passed away. We therefore decided to dedicate the 7th European Conference on Applied Superconductivity to the memory of Jan Evetts. The following citation is based on material provided by his former supervisor (D Dew-Hughes) and his closest co-workers in Cambridge. Professor Jan Edgar Evetts (1939-2005) Professor Jan Edgar Evetts (1939-2005) Jan Evetts passed away after losing his second battle with cancer on 24th August 2005. He made an outstanding series of contributions to the science of superconductivity and to the understanding of superconducting materials and was an indefatigable champion of the development of applications of superconductivity. The loss to the superconductivity community is incalculable, as attested by the many communications received from colleagues throughout the world. Jan was born on 31 March 1939, and attended the Dragon School in Oxford, and later Haileybury. He was awarded an exhibition to read Natural Sciences at Pembroke College, Cambridge. He entered the college in 1958 and took his BA degree in 1961. He then undertook a Certificate of Postgraduate Study in Physics under the supervision of Professor Neville Mott. He was the first student to undertake this newly-instituted course; the title of his thesis was `The Resistance of Transition Metals'. In 1962 he joined David Dew-Hughes' superconducting materials research group, along with Archie Campbell and Anant Narlikar. In fact it was Jan's enthusiasm for the proposed course of research that helped convince David that he should follow Professor Alan Cottrell's suggestion to apply metallurgical methodology to the study of the factors that controlled critical current density in the type II superconductors that were then under development for

Using Intact Iron Microbial Mats to Gain Insights Into Mat Ecology and Geochemical Niche at the Microbial Scale

NASA Astrophysics Data System (ADS)

Glazer, B. T.; Chan, C. S. Y.; Mcallister, S.; Leavitt, A.; Emerson, D.

2015-12-01

Microbial mats are formed by microorganisms working in coordinated symbiosis, often benefitting the community by controlling the local geochemical or physical environment. Thus, the ecology of the mat depends on the individual roles of microbes organized into niches within a larger architecture. Chemolithotrophic Fe-oxidizing bacteria (FeOB) form distinctive Fe oxyhydroxide biominerals which constitute the building blocks of the mat. However, the majority of our progress has been in understanding the overall community structure. Understanding the physical mat structure on the microbial scale is important to unraveling FeOB evolution, the biogeochemistry and ecology of Fe-rich habitats, and ultimately interpreting FeOB biosignatures in the rock record. Mats in freshwater and marine environments contain strikingly similar biomineral morphologies, yet they are formed by phylogenetically distinct microorganisms. This suggests that the overall architecture and underlying genetics of freshwater and marine mats has evolved to serve particular roles specific to Fe oxidation. Thus, we conducted a comparative study of Fe seep freshwater mats and marine hydrothermal mats. We have developed a new approach to sampling Fe mats in order to preserve the delicate structure for analysis by confocal and scanning electron microscopy. Our analyses of these intact mats show that freshwater and marine mats are similarly initiated by a single type of structure-former. These ecosystem engineers form either a hollow sheath or a twisted stalk biomineral during mat formation, with a highly directional structure. These microbes appear to be the vanguard organisms that anchor the community within oxygen/Fe(II) gradients, further allowing for community succession in the mat interior as evidenced by other mineralized morphologies. Patterns in biomineral thickness and directionality were indicative of redox gradients and temporal changes in the geochemical environment. These observations show that

Infant Child Care. ERIC Digest.

ERIC Educational Resources Information Center

Howes, Carollee

This ERIC Digest briefly reviews studies of maternal employment, child care settings, and links between children's development and family and child care influences. Studies of maternal employment suggest that infants' positive relationships with caregivers may compensate for insecure attachments with mothers. If future research supports this…

Cost and Usage Study of the Educational Resources Information Center (ERIC) System. Final Report.

ERIC Educational Resources Information Center

McDonald, Dennis D; And Others

A detailed descriptive analysis of both the direct and indirect costs incurred by the Federal government in operating the ERIC system, and the user population and user demand for ERIC products and services, this study is based on data gathered from a number of complementary sources. These sources included a survey of ERIC's U.S. intermediate…

The Legacy of Jan Kappers.

ERIC Educational Resources Information Center

Bakker, Dirk J.

1997-01-01

This brief introduction to E. Jan Kappers' article "Outpatient Treatment of Dyslexia through Stimulation of the Cerebral Hemispheres" reviews the lifetime work of Kappers in the field of dyslexia. (CR)

M.A.T. Programs.

ERIC Educational Resources Information Center

Wildman, Louis

A proposal is presented for developing a Master of Arts in Teaching (MAT) program at California State University, Bakersfield. The criteria for a MAT program are examined by outlining existing programs at: (1) Harvard Graduate School; (2) University of California, Berkeley; (3) Portland State University; (4) Stanford University; (5) University of…

The Shy Child. ERIC Digest.

ERIC Educational Resources Information Center

Hyson, Marion C.; Van Trieste, Karen

This ERIC digest: (1) describes types and manifestations of shyness among children; (2) briefly reviews research on genetic, temperamental, and environmental influences on shyness; (3) distinguishes between normal and problematic shyness; and (4) suggests ways for parents and teachers to help the shy child by accepting the whole child, building…

Coaching for Tests. ERIC Digest.

ERIC Educational Resources Information Center

Wildemuth, Barbara

The term "coaching" applies to a variety of types of test preparation programs which vary in length, instructional method, and content. Most research on the effectiveness of coaching has examined the Scholastic Aptitude Test (SAT), a measure of academic abilities used to predict college performance. This ERIC Digest reviews studies of…

PA15 Beer mat chat.

PubMed

Hazelwood, Mark A; Patterson, Rebecca M

2015-04-01

Storytelling/remembrance can the reduce isolation of recently (and less recently) bereaved people, and are beneficial to participants. Traditional rituals and approaches which supported storytelling/remembrance are declining in Scotland. Pubs are hubs of social interaction and storytelling, especially for men. To explore the acceptability of beer mats in pubs as a prompt to storytelling and remembrance of people who have died, and to promote To Absent Friends, a peoples' festival of storytelling and remembrance. 5 mats were designed - each had a carefully selected quotation or piece of trivia relating to loss or remembrance, plus a web link to www.toabsentfriends.org.uk. 20,000 mats were made available to order. Feedback regarding acceptability was elicited through conversation with bar tenders, direct observation and a questionnaire dispatched with some orders. A press release was issued. The mats were generally viewed as being acceptable. A local brewer distributed Approximately 15,000 mats to pubs across Edinburgh. The main Edinburgh newspaper ran a prominent article about the mats, the To Absent Friends Festival and the value of greater openness about death and dying. Beer mats are an acceptable way of introducing reflection on loss, grief and mortality into pubs. More research is needed to establish the effectiveness of the mats in prompting storytelling and remembrance. © 2015, Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

Vocabulary Development and Maintenance--Descriptors. ERIC Processing Manual, Section VIII (Part 1).

ERIC Educational Resources Information Center

Houston, Jim, Ed.

Comprehensive rules, guidelines, and examples are provided for use by ERIC indexers and lexicographers in developing and maintaining the "Thesaurus of ERIC Descriptors." Evaluation and decision criteria, research procedures, and inputting details for adding new Descriptors are documented. Instructions for modifying existing Thesaurus…

Early Childhood Curricula. ERIC/EECE Report.

ERIC Educational Resources Information Center

Cesarone, Bernard

2003-01-01

Summarizes recent ERIC documents and journal articles, and highlights some World Wide Web resources that describe, evaluate, or compare various curricula or instructional methods, such as Creative Curriculum, High/Scope, the Montessori Method, Waldorf Schools, and Direct Instruction. (Author)

Refugees in the United States: A Bibliography of ERIC Documents. ERIC/CUE Bibliography Number 7.

ERIC Educational Resources Information Center

Ascher, Carol; Alladice, Darryl

This bibliography contains 303 citations of conference papers, research and project reports, and other materials drawn from the ERIC database. The entries are organized according to a number of issues relating to the resettlement and adaptation of Indochinese, Cuban, Haitian, and Russian refugees in the United States. The categories include:…

Grandma Moses Meets Eric Carle

ERIC Educational Resources Information Center

Sutley, Jane

2012-01-01

This activity features artwork by "Grandma Moses" in which children will learn the picture plane in terms of foreground, middle ground, and background. The teacher also introduces the children to Eric Carle's colorful collaged images in his books. Using the two artists' methods, children experimented and invented new techniques and colors. As the…

China's Vocational Universities. ERIC Digest.

ERIC Educational Resources Information Center

Ding, Anning

This ERIC Digest describes the development and characteristics of vocational universities (VUs) in China. In response to the demand for increased numbers of trained technical workers in the 1980's, VUs developed and the higher vocational education system in China was reformed. Currently, 101 vocational universities are in existence in China. These…

ERIC Abstracts: A Collection of ERIC Document Resumes on Citizen Involvement in the Control of Schools.

ERIC Educational Resources Information Center

American Association of School Administrators, Washington, DC.

ERIC abstracts on citizen involvement in the control of schools, announced in RIE through Novermber 1970, are presented. The key terms used in compiling this collection are "citizen participation,""decentralization,""parent participation,""parent school relationship,""school community relationship," and "school district autonomy." The following…

The Only Child. ERIC Digest.

ERIC Educational Resources Information Center

Steiner, Karen

Smaller families in general (including the one-child option) are becoming more popular. This ERIC Digest focuses on changing trends in family size, reasons for choosing to have only one child, differences between only children and those with siblings, and the advantages of being an only child. Changing family patterns, economic concerns, and new…

Vocabulary Development and Maintenance--Identifiers. ERIC Processing Manual, Section VIII (Part 2).

ERIC Educational Resources Information Center

Weller, Carolyn R., Ed.; Houston, Jim, Ed.

Comprehensive rules, guidelines, and examples are provided for use by ERIC indexers and lexicographers in creating and using Identifiers, and in developing and maintaining the ERIC Identifier file via the "Identifier Authority List (IAL)." Identifiers and the IAL are defined/described: Identifiers are highly specific entities, including…

Cost and Usage Study of the Educational Resources Information Center (ERIC) System. A Descriptive Summary.

ERIC Educational Resources Information Center

Heinmiller, Joseph L.

Based on data gathered from a number of complementary sources, this study provides a detailed descriptive analysis of both the direct and indirect costs incurred by the Federal government in operating the ERIC system, and the user population and user demand for ERIC products and services. Data sources included a survey of ERIC's U.S. intermediate…

Analysis of the MAT1-1 and MAT1-2 Gene Ratio in Black Koji Molds Isolated from Meju.

PubMed

Mageswari, Anbazhagan; Kim, Jeong-Seon; Cheon, Kyu-Ho; Kwon, Soon-Wo; Yamada, Osamu; Hong, Seung-Beom

2016-12-01

Aspergillus luchuensis is known as an industrially important fungal species used for making fermented foods such as awamori and shochu in Japan, makgeolli and Meju in Korea, and Pu-erh tea in China. Nonetheless, this species has not yet been widely studied regarding mating-type genes. In this study, we examined the MAT1-1 and MAT1-2 gene ratio in black koji molds ( A. luchuensis , Aspergillus niger , and Aspergillus tubingensis ) and in Aspergillus welwitschiae isolated from Meju, a fermented soybean starting material for traditional soy sauce and soybean paste in Korea. The number of strains with the MAT1-1 locus was 2 of 23 ( A. luchuensis ), 6 of 13 ( A. tubingensis ), 21 of 28 ( A. niger ), and 5 of 10 ( A. welwitschiae ). Fungal species A. tubingensis and A. welwitschiae showed a 1 : 1 ratio of MAT1-1 and MAT1-2 mating-type loci. In contrast, A. luchuensis revealed predominance of MAT1-2 (91.3%) and A. niger of MAT1-1 (75%). We isolated and identified 2 A. luchuensis MAT1-1 strains from Meju, although all strains for making shochu in Japan are of the MAT1-2 type. These strains may be a good resource for breeding of A. luchuensis to be used in the Asian fermented-food industry.

Analysis of the MAT1-1 and MAT1-2 Gene Ratio in Black Koji Molds Isolated from Meju

PubMed Central

Mageswari, Anbazhagan; Kim, Jeong-seon; Cheon, Kyu-Ho; Kwon, Soon-Wo

2016-01-01

Aspergillus luchuensis is known as an industrially important fungal species used for making fermented foods such as awamori and shochu in Japan, makgeolli and Meju in Korea, and Pu-erh tea in China. Nonetheless, this species has not yet been widely studied regarding mating-type genes. In this study, we examined the MAT1-1 and MAT1-2 gene ratio in black koji molds (A. luchuensis, Aspergillus niger, and Aspergillus tubingensis) and in Aspergillus welwitschiae isolated from Meju, a fermented soybean starting material for traditional soy sauce and soybean paste in Korea. The number of strains with the MAT1-1 locus was 2 of 23 (A. luchuensis), 6 of 13 (A. tubingensis), 21 of 28 (A. niger), and 5 of 10 (A. welwitschiae). Fungal species A. tubingensis and A. welwitschiae showed a 1 : 1 ratio of MAT1-1 and MAT1-2 mating-type loci. In contrast, A. luchuensis revealed predominance of MAT1-2 (91.3%) and A. niger of MAT1-1 (75%). We isolated and identified 2 A. luchuensis MAT1-1 strains from Meju, although all strains for making shochu in Japan are of the MAT1-2 type. These strains may be a good resource for breeding of A. luchuensis to be used in the Asian fermented-food industry. PMID:28154484

Ectomycorrhizal mats alter forest soil biogeochemistry

Treesearch

Laurel A. Kluber; Kathryn M. Tinnesand; Bruce A. Caldwell; Susie M. Dunham; Rockie R. Yarwood; Peter J. Bottomley; David D. Myrold

2010-01-01

Dense hyphal mats formed by ectomycorrhizal (EcM) fungi are prominent features in Douglas-fir forest ecosystems, and have been estimated to cover up to 40% of the soil surface in some forest stands. Two morphotypes of EcM mats have been previously described: rhizomorphic mats, which have thick hyphal rhizomorphs and are found primarily in the organic horizon, and...

Meet EPA Microbiologist Eric Villegas, Ph.D.

EPA Pesticide Factsheets

Eric Villegas, Ph.D. is a research microbiologist in EPA's Office of Research and Development. His recent work focuses on next generation sequencing technology to better understand risks associated with waterborne parasites.

Distance Education at the Elementary and Secondary Level. A Select ERIC Bibliography. ERIC/IR Mini-Bib.

ERIC Educational Resources Information Center

Preston, Nancy R., Comp.

This annotated bibliography lists 10 articles and documents selected through a search of the Educational Resources Information Center (ERIC) database. They are: (1) "The Use of Computers in the Instructional Process in Australian Distance Education" (Geoff Arger and Debbie Clayton); (2) "Distance Education Technologies: All That Glitters Is Not…

Magnetoacoustic tomography with magnetic induction (MAT-MI)

NASA Astrophysics Data System (ADS)

Xu, Yuan; He, Bin

2005-11-01

We report our theoretical and experimental investigations on a new imaging modality, magnetoacoustic tomography with magnetic induction (MAT-MI). In MAT-MI, the sample is located in a static magnetic field and a time-varying (µs) magnetic field. The time-varying magnetic field induces an eddy current in the sample. Consequently, the sample will emit ultrasonic waves by the Lorentz force. The ultrasonic signals are collected around the object to reconstruct images related to the electrical impedance distribution in the sample. MAT-MI combines the good contrast of electrical impedance tomography with the good spatial resolution of sonography. MAT-MI has two unique features due to the solenoid nature of the induced electrical field. Firstly, MAT-MI could provide an explicit or simple quantitative reconstruction algorithm for the electrical impedance distribution. Secondly, it promises to eliminate the shielding effects of other imaging modalities in which the current is applied directly with electrodes. In the theoretical part, we provide formulae for both the forward and inverse problems of MAT-MI and estimate the signal amplitude in biological tissues. In the experimental part, the experimental setup and methods are introduced and the signals and the image of a metal object by means of MAT-MI are presented. The promising pilot experimental results suggest the feasibility of the proposed MAT-MI approach.

Indexing. ERIC Processing Manual, Section VII.

ERIC Educational Resources Information Center

Houston, Jim, Ed.

Rules and guidelines are provided for subject indexing in the ERIC system. The principle of "subject access" is discussed with particular reference to "coordinate indexing," which involves designating subject content by unit terms (or tags) that may be put together or "coordinated" for subsequent retrieval. The nature…

ERIC/EECE Report. Mixed Age Grouping.

ERIC Educational Resources Information Center

Cesarone, Bernard

1995-01-01

Summarizes eight recent ERIC documents and seven journal articles on mixed-age grouping. Includes discussions of teaching in the multiage classroom, Kentucky's Primary Program, developmentally appropriate practices in the primary grades, thematic instruction, attitudes toward mixed-age grouping, and questions and answers about mixed-age grouping.…

Launch of Mercury-Redstone vehicle 2 on Jan. 21, 1961

NASA Image and Video Library

1961-08-10

S61-01942 (31 Jan. 1961) --- Launch of the Mercury-Redstone 2 (MR-2) vehicle on Jan. 31, 1961. The 16-minute suborbital flight carried biomedical test subject chimpanzee (Ham) aboard. Photo credit: NASA

Eric Garcia: Warrior with a Pen

ERIC Educational Resources Information Center

Briggs, Judith

2013-01-01

Eric Garcia's large-scale oil paintings, drawings, installations, prints, and political cartoons examine versions of American history that have been overlooked and whitewashed. Aware that dominant history reflects a strategy of power, Garcia embraces the confluence of history, culture, and politics to challenge historical mythologies and…

How to Search the ERIC File.

ERIC Educational Resources Information Center

Mathies, Lorraine

1972-01-01

The ERIC information system is designed for computerized information storage and retrieval. While the computer can play an increasingly more vital role in facilitating reference searches of large literature collections, experience shows that manual searching gives the user skills and expertise that are essential to effectively use the computerized…

Biogeochemistry of Microbial Mats

NASA Technical Reports Server (NTRS)

DesMarais, David J.; DeVincenizi, D. (Technical Monitor)

2002-01-01

The hierarchical organization of microbial ecosystems determines the rates of processes that shape Earth's environment, define the stage upon which major evolutionary events occurred, and create biosignatures in sediments and atmospheres. In cyanobacterial mats, oxygenic photosynthesis provides energy, organic substrates and oxygen to the ecosystem. Incident light changes with depth in the mat, both in intensity and spectral composition, and counteracting gradients of oxygen and sulfide shape the chemical microenvironment. A combination of benefits and hazards of light, oxygen and sulfide promotes the allocation of the various essential mat processes between light and dark periods and to various depths in the mat. Microliters produce hydrogen, small organic acids, nitrogen and sulfur species. Such compounds fuel a flow of energy and electrons in these ecosystems and thus shape interactions between groups of microorganisms. Coordinated observations of population distribution, abundance, and activity for an entire community are making fundamental questions in ecology accessible. These questions address those factors that sustain the remarkable diversity of microorganisms that are now being revealed by molecular techniques. These questions also target the processes that shape the various kinds of biosignatures that we will seek, both in ancient rocks from Earth and Mars, and in atmospheres of distant planets beyond our Solar System.

Solution blowing of chitosan/PVA hydrogel nanofiber mats.

PubMed

Liu, Ruifang; Xu, Xianlin; Zhuang, Xupin; Cheng, Bowen

2014-01-30

Both nanofiber mats and hydrogel have their own advantages in wound healing. In this study, a novel hydrogel nanofiber mats were fabricated via solution blowing of chitosan and PVA solution, with various content of ethylene glycol diglycidyl ether (EGDE) as cross-linker. SEM observation showed that the fibers were several hundred nanometers in diameter with smooth surface and distributed randomly forming three-dimensional mats. The structure of the chitosan/PVA nanofibers was examined by FTIR and XPS, and the results showed that the cross-linking reaction occurred between EGDE and the hydroxyl groups. The mats could quickly hydrate in an aqueous environment to form hydrogel. Their value of equilibrate water absorption varied from 680 to 459% various content of EGDE. The nanofiber mats showed good bactericidal activity against Escherichia coli. The chitosan/PVA hydrogel nanofiber mats showed the combination advantages of nanofibrous mats and hydrogel dressing, and were suggested as potential application in wound healing. Copyright © 2013 Elsevier Ltd. All rights reserved.

Selection. ERIC Processing Manual, Section III.

ERIC Educational Resources Information Center

Brandhorst, Ted, Ed.

Rules and guidelines are provided governing the selection of documents and journal articles to be included in the ERIC database. Selection criteria are described under the five headings: (1) Appropriateness of content/subject matter; (2) Suitability of format, medium, document type; (3) Quality of content; (4) Legibility and reproducibility; (5)…

Teaching about Presidential Elections. ERIC Digest.

ERIC Educational Resources Information Center

Vontz, Thomas S.; Nixon, William A.

Although elections are an annual theme in many social studies classrooms, presidential election years prompt increased interest among students in the electoral process and offer an opportunity to teach about a national election as it happens. This ERIC Digest describes the legal requirements and traditions of U.S. presidential elections, processes…

School Productivity. ERIC Digest, Number 119.

ERIC Educational Resources Information Center

Hadderman, Margaret

Some of the issues surrounding school productivity are discussed in this ERIC digest. It presents the results of early research that explored whether there is a relationship between educational funding and student outcomes. Some of the reasons behind schools' productivity problems are presented, including problems with unstable governance and the…

Compositions of constructed microbial mats

DOEpatents

Bender, Judith A.; Phillips, Peter C.

1999-01-01

Compositions and methods of use of constructed microbial mats, comprising cyanobacteria and purple autotrophic bacteria and an organic nutrient source, in a laminated structure, are described. The constructed microbial mat is used for bioremediation of different individual contaminants and for mixed or multiple contaminants, and for production of beneficial compositions and molecules.

Reading Teachers and Their Students (ERIC/RCS).

ERIC Educational Resources Information Center

Sensenbaugh, Roger

1992-01-01

Presents annotations of nine articles from the ERIC database that discuss the pedagogical relationship between reading teachers and their students. Includes articles that deal with whole-language instruction, student motivation, instructional grouping, questioning techniques, and the characteristics of effective teachers. (PRA)

Teaching Broadcast Journalism: An ERIC/RCS Report

ERIC Educational Resources Information Center

Swiss, Thom; Ladevich, Laurel

1977-01-01

Offers an annotated bibliography of documents available through the ERIC system that can aid teachers in developing a broadcast journalism course or curriculum, adding to an established one, or expanding a print-oriented journalism curriculum to include broadcast journalism. (GW)

Computer-Based Education: The Best of ERIC, June 1976-1982. Revised and Updated.

ERIC Educational Resources Information Center

Hall, Keith A.

This revision of the annotated bibliography, "Computer-Based Education: The Best of ERIC, June 1976-August 1980," includes 224 new entries as well as most of the 156 ERIC documents and journal articles originally cited. The new materials reflect the increased activity in the field with contributions about new technology (artificial…

Jan Potocki et le "Gothic Novel"

ERIC Educational Resources Information Center

Finne, Jacques

1970-01-01

Establishes a parallel between the supernatural and fantastic qualities of Le Comte Jan Potocki's literary works, and the English gothic novels by comparing the elements of terror, mysterious atmosphere, and the supernatural beings involved. (DS)

Use of palm-mat geotextiles for rainsplash erosion control

NASA Astrophysics Data System (ADS)

Bhattacharyya, R.; Fullen, M. A.; Davies, K.; Booth, C. A.

2010-07-01

Soil detachment by raindrop action (rainsplash erosion) is a very important subprocess of erosion by water. It is a particular problem in the UK as most soils are sandy or loamy sand in texture and lands have gentle to medium slope. However, few studies report potential rainsplash erosion control options under field conditions. Hence, the utilization of palm-mat geotextiles as a rainsplash erosion control technique was investigated at Hilton, east Shropshire, U.K. (52°33'5.7″ N, 2°19'18.3″ W). Geotextile-mats constructed from Borassus aethiopum (Borassus palm of West Africa) and Mauritia flexuosa (Buriti palm of South America) leaves are termed Borassus mats and Buriti mats, respectively. Two-year field experiments were conducted at Hilton to study the effects of emplacing Borassus and Buriti mats on rainsplash erosion of a loamy sand soil. Two sets (12 plots each) of experiments were established to study the effects of these mats on splash height and splash erosion. Splash height needs to be known to assess the transport mechanism of major soil fraction and its constituents on sloping land by rainsplash. In both sets, six randomly-selected plots were covered with mats, and the rest were bare. Results (during 22/01/2007‒23/01/2009; total precipitation = 1731.5 mm) show that Borassus mat-covered plots had ˜ 89% ( P < 0.001) less total splash erosion (2.97 kg m - 2 ) than bare plots (27.02 kg m - 2 ). Comparatively, mean splash height from Borassus mat-covered plots (0.12 m) was significantly ( P < 0.001) less than the bare plots, by ˜ 54%. However, Buriti mat-cover on bare plots had no significant ( P > 0.05) effect in rainsplash erosion control during that period, although plots with Buriti mats significantly ( P < 0.05) decreased splash height (by ˜ 18%) compared with bare plots (0.26 m). Buriti mats, probably due to their ˜ 43, 62 and 50% lower cover percentage (44%), mass per unit area (413 g - 2 ) and thickness (10 mm), respectively, compared with

Regulation of electron transfer processes affects phototrophic mat structure and activity

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ha, Phuc T.; Renslow, Ryan S.; Atci, Erhan

Phototrophic microbial mats are among the most diverse ecosystems in nature. These systems undergo daily cycles in redox potential caused by variations in light energy input and metabolic interactions among the microbial species. In this work, solid electrodes with controlled potentials were placed under mats to study the electron transfer processes between the electrode and the microbial mat. The phototrophic microbial mat was harvested from Hot Lake, a hypersaline, epsomitic lake located near Oroville (Washington, USA). We operated two reactors: graphite electrodes were polarized at potentials of -700 mV Ag/AgCl [cathodic (CAT) mat system] and +300 mV Ag/AgCl [anodic (AN)more » mat system] and the electron transfer rates between the electrode and mat were monitored. We observed a diel cycle of electron transfer rates for both AN and CAT mat systems. Interestingly, the CAT mats generated the highest reducing current at the same time points that the AN mats showed the highest oxidizing current. To characterize the physicochemical factors influencing electron transfer processes, we measured depth profiles of dissolved oxygen (DO) and sulfide in the mats using microelectrodes. We further demonstrated that the mat-to-electrode and electrode-to-mat electron transfer rates were light- and temperature-dependent. Using nuclear magnetic resonance (NMR) imaging, we determined that the electrode potential regulated the diffusivity and porosity of the microbial mats. Both porosity and diffusivity were higher in the CAT mats than in the AN mats. We also used NMR spectroscopy for high-resolution quantitative metabolite analysis and found that the CAT mats had significantly higher concentrations of osmoprotectants such as betaine and trehalose. Subsequently, we performed amplicon sequencing across the V4 region of the 16S rRNA gene of incubated mats to understand the impact of electrode potential on microbial community structure. In conclusion, these data suggested that

Regulation of electron transfer processes affects phototrophic mat structure and activity

DOE PAGES

Ha, Phuc T.; Renslow, Ryan S.; Atci, Erhan; ...

2015-09-03

Phototrophic microbial mats are among the most diverse ecosystems in nature. These systems undergo daily cycles in redox potential caused by variations in light energy input and metabolic interactions among the microbial species. In this work, solid electrodes with controlled potentials were placed under mats to study the electron transfer processes between the electrode and the microbial mat. The phototrophic microbial mat was harvested from Hot Lake, a hypersaline, epsomitic lake located near Oroville (Washington, USA). We operated two reactors: graphite electrodes were polarized at potentials of -700 mV Ag/AgCl [cathodic (CAT) mat system] and +300 mV Ag/AgCl [anodic (AN)more » mat system] and the electron transfer rates between the electrode and mat were monitored. We observed a diel cycle of electron transfer rates for both AN and CAT mat systems. Interestingly, the CAT mats generated the highest reducing current at the same time points that the AN mats showed the highest oxidizing current. To characterize the physicochemical factors influencing electron transfer processes, we measured depth profiles of dissolved oxygen (DO) and sulfide in the mats using microelectrodes. We further demonstrated that the mat-to-electrode and electrode-to-mat electron transfer rates were light- and temperature-dependent. Using nuclear magnetic resonance (NMR) imaging, we determined that the electrode potential regulated the diffusivity and porosity of the microbial mats. Both porosity and diffusivity were higher in the CAT mats than in the AN mats. We also used NMR spectroscopy for high-resolution quantitative metabolite analysis and found that the CAT mats had significantly higher concentrations of osmoprotectants such as betaine and trehalose. Subsequently, we performed amplicon sequencing across the V4 region of the 16S rRNA gene of incubated mats to understand the impact of electrode potential on microbial community structure. In conclusion, these data suggested that

Delivery Systems for Distance Education. ERIC Digest.

ERIC Educational Resources Information Center

Schamber, Linda

This ERIC digest provides a brief overview of the video, audio, and computer technologies that are currently used to deliver instruction for distance education programs. The video systems described include videoconferencing, low-power television (LPTV), closed-circuit television (CCTV), instructional fixed television service (ITFS), and cable…

ERIC/ChESS: Teaching High School Economics.

ERIC Educational Resources Information Center

Smiddie, Laura

1990-01-01

Presents an annotated list of materials from the Educational Resources Information Center (ERIC) database for high school teachers concerned with teaching economic concepts. Materials include lesson plans using writing exercises; simulations in stock market operations; class activities on economics and the U.S. Constitution; and instructional…

ERIC/ChESS: Teaching World History Today.

ERIC Educational Resources Information Center

Seiter, David M.

1989-01-01

Lists and describes some resources on teaching world history that are available from the Educational Resource Information Center (ERIC). Articles cover periodization, humanistic approaches, hierarchical organization of knowledge, skills in world history, teaching about Japan to students in Texas, Oklahoma, and Louisiana, global history, and a…

Eric Boe and Bob Behnken - Dragon Tour

NASA Image and Video Library

2017-03-08

Astronaut Eric Boe examines hardware during a tour of the SpaceX facility in Hawthorne, California. SpaceX is developing its Crew Dragon spacecraft and Falcon 9 rocket in partnership with NASA’s Commercial Crew Program to carry astronauts to and from the International Space Station.

Eric Boe and Bob Behnken - Dragon Tour

NASA Image and Video Library

2017-03-08

Astronauts Bob Behnken, left, and Eric Boe are outside the SpaceX facility in Hawthorne, California. SpaceX is developing its Crew Dragon spacecraft and Falcon 9 rocket in partnership with NASA’s Commercial Crew Program to carry astronauts to and from the International Space Station.

Studying Microbial Mat Functioning Amidst "Unexpected Diversity": Methodological Approaches and Initial Results from Metatranscriptomes of Mats Over Diel cycles, iTags from Long Term Manipulations, and Biogeochemical Cycling in Simplified Microbial Mats Constructed from Cultures

NASA Astrophysics Data System (ADS)

Bebout, B.; Bebout, L. E.; Detweiler, A. M.; Everroad, R. C.; Lee, J.; Pett-Ridge, J.; Weber, P. K.

2014-12-01

Microbial mats are famously amongst the most diverse microbial ecosystems on Earth, inhabiting some of the most inclement environments known, including hypersaline, dry, hot, cold, nutrient poor, and high UV environments. The high microbial diversity of microbial mats makes studies of microbial ecology notably difficult. To address this challenge, we have been using a combination of metagenomics, metatranscriptomics, iTags and culture-based simplified microbial mats to study biogeochemical cycling (H2 production, N2 fixation, and fermentation) in microbial mats collected from Elkhorn Slough, Monterey Bay, California. Metatranscriptomes of microbial mats incubated over a diel cycle have revealed that a number of gene systems activate only during the day in Cyanobacteria, while the remaining appear to be constitutive. The dominant cyanobacterium in the mat (Microcoleus chthonoplastes) expresses several pathways for nitrogen scavenging undocumented in cultured strains, as well as the expression of two starch storage and utilization cycles. Community composition shifts in response to long term manipulations of mats were assessed using iTags. Changes in community diversity were observed as hydrogen fluxes increased in response to a lowering of sulfate concentrations. To produce simplified microbial mats, we have isolated members of 13 of the 15 top taxa from our iTag libraries into culture. Simplified microbial mats and simple co-cultures and consortia constructed from these isolates reproduce many of the natural patterns of biogeochemical cycling in the parent natural microbial mats, but against a background of far lower overall diversity, simplifying studies of changes in gene expression (over the short term), interactions between community members, and community composition changes (over the longer term), in response to environmental forcing.

Freedom of Expression: A Troublesome Imperative. ERIC Report.

ERIC Educational Resources Information Center

Del Polito, Carolyn M.

1980-01-01

Presents an annotated bibliography of 19 items from ERIC identifying troublesome paradoxes regarding the media and freedom of expression. Items are categorized by issues identified as relevant to radio and television, commercial advertising, and the press. (JMF)

Cyanobacterial mats: Microanalysis of community metabolism

NASA Technical Reports Server (NTRS)

Cohen, Y.; Bermudes, D.; Fischer, U.; Haddad, R.; Prufert, L.; Scheulderman-Suylen, T.; Shaw, T.

1985-01-01

The microbial communities in two sites were studied using several approaches: (1) light microscopy; (2) the measurement of microprofiles of oxygen and sulfide at the surface of the microbial mat; (3) the study of diurnal variation of oxygen and sulfides; (4) in situ measurement of photosynthesis and sulfate reduction and study of the coupling of these two processes; (5) measurement of glutathione in the upper layers of the microbial mat as a possible oxygen quencher; (6) measurement of reduced iron as a possible intermediate electron donor along the established redoxcline in the mats; (7) measurement of dissolved phosphate as an indicator of processes of break down of organic matter in these systems; and (8) measurement of carbon dioxide in the interstitial water and its delta C-13 in an attempt to understand the flow of CO2 through the systems. Microbial processes of primary production and initial degradation at the most active zone of the microbial mat were analyzed.

Abstracting/Annotating. ERIC Processing Manual, Section VI.

ERIC Educational Resources Information Center

Brandhorst, Ted, Ed.

Rules and guidelines are provided for the preparation of abstracts and annotations for documents and journal articles entering the ERIC database. Various types of abstracts are defined, including the Informative, Indicative, and mixed Informative-Indicative. Advice is given on how to select the abstract type appropriate for the particular…

Design of ERIC Usage Studies. Volume I.

ERIC Educational Resources Information Center

ERIC Clearinghouse on Information Resources, Syracuse, NY.

Tables showing the types of Educational Resources Information Center (ERIC) products and their dispersion provide background information for the executive summaries of usage study design reports focusing on three levels: (1) system operations; (2) subscribers to the services provided; and (3) the ultimate "end-users" of the service. The…

Television Violence and Children. ERIC/EECE Report.

ERIC Educational Resources Information Center

Cesarone, Bernard

1998-01-01

Summarizes 12 recent documents and journal articles from the ERIC database that discuss topics related to television violence and children. Articles cited address the effects of television violence on child behavior and attitudes at school and home, and methods of reducing the impact of television on children. (JPB)

Benthic Marine Cyanobacterial Mat Ecosystems: Biogeochemistry and Biomarkers

NASA Technical Reports Server (NTRS)

DesMarais, David J.; DeVincenzi, Donald (Technical Monitor)

2001-01-01

Cyanobacterial mats are complete ecosystems that can include processes of primary production, diagenesis and lithification. Light sustains oxygenic photosynthesis, which in turn provides energy, organic matter and oxygen to the community. Due to both absorption and scattering phenomena, incident light is transformed with depth in the mat, both in intensity and spectral composition. Mobile photo synthesizers optimize their position with respect to this light gradient. When photosynthesis ceases at night, the upper layers of the mat become reduced and sulfidic. Counteracting gradients of oxygen and sulfide combine to provide daily-contrasting environments separated on a scale of a few mm. The functional complexity of mats, coupled with the highly proximal and ordered spatial arrangement of biota, offers the potential for a staggering number of interactions. At a minimum, the products of each functional group of microorganisms affect the other groups both positively and negatively. For example, cyanobacteria generate organic matter (potential substrates) but also oxygen (a toxin for many anaerobes). Anaerobic activity recycles nutrients to the photosynthesizers but also generates potentially toxic sulfide. The combination of benefits and hazards of light, oxygen and sulfide promotes the allocation of the various essential mat processes between light and dark periods, and to various depths in the mat. Observations of mats have produced numerous surprises. For example, obligately anaerobic processes can occur in the presence of abundant oxygen, highly reduced gases are produced in the presence of abundant sulfate, meiofauna thrive at high sulfide concentrations, and the mats' constituent populations respond to environmental changes in complex ways. While photosynthetic bacteria dominate the biomass and productivity of the mat, nonphotosynthetic, anaerobic processes constitute the ultimate biological filter on the ecosystem's emergent biosignatures, including those

Ecophysiological Changes in Microbial Mats Incubated in a Greenhouse Collaboratory

NASA Technical Reports Server (NTRS)

Bebout, Brad; DesMarais, David J.; GarciaPichel, Ferran; Hogan, Mary; Jahnke, Linda; Keller, Richard M.; Miller, Scott R.

2001-01-01

Microbial mats are modern examples of the earliest microbial communities known. Among the best studied are microbial mats growing in hypersaline ponds managed for the production of salt by Exportadora de Sal, S.A. de C.V., Guerrero Negro, Baja California Sur, Mexico. In May, 2001, we collected mats from Ponds 4 and 5 in this system and returned them to Ames Research Center, where they have been maintained for a period of over nine months. We report here on both the ecophysiological changes occurring in the mats over that period of time as well as the facility in which they were incubated. Mats (approximately 1 sq. meter total area) were incubated in a greenhouse facility modified to provide the mats with natural levels of visible and ultraviolet radiation as well as constantly flowing, temperature-controlled water. Two replicated treatments were maintained, a 'high salinity' treatment (about 120 ppt) and a 'low salinity' treatment (about 90 ppt). Rates of net biological activity (e.g., photosynthesis, respiration, trace gas production) in the mats were relatively constant over the several months, and were similar to rates of activity measured in the field. However, over the course of the incubation, mats in both treatments changed in physical appearance. The most obvious change was that mats in the higher salinity treatments developed a higher proportion of carotenoid pigments (relative to chlorophyll), resulting in a noticeably orange color in the high salinity mats. This trend is also seen in the natural salinity gradient present at the field site. Changes in the community composition of the mats, as assayed by denaturing gradient gel electrophoresis (DGGE), as well as biomarker compounds produced in the mats were also monitored. The degree to which the mats kept in the greenhouse changed from the originally collected mats, as well as differences between high and low salinity mats will be discussed. Additional information is contained in the original extended

Author! Author! Jan Brett: Hedgehogs, Trolls, and a Gingerbread Baby

ERIC Educational Resources Information Center

Brodie, Carolyn S.

2005-01-01

This column presents a brief biography of author Jan Brett. According to Jan Brett's official webpage, there have been more than twenty-eight million of her books printed. Her titles can always be found on the best-selling children's book author/illustrator lists. Brett is one of the most beloved and recognized children's book illustrators and is…

Alternative Models for the ERIC Clearinghouse Network.

ERIC Educational Resources Information Center

Greenwood, P. W.; Weiler, D. M.

The National Center for Educational Communication (NCEC) contracted with Rand to develop a range of potential objectives and structures for the Educational Resources Information Center (ERIC) system that could render it more effective in the future. The Rand study team surveyed the scope and sources of education literature and studied the…

Simulation and Gaming: The Best of ERIC.

ERIC Educational Resources Information Center

Coombs, Don H., Comp.

Most of the 101 citations included in this annotated bibliography on simulation and gaming were derived from a search of the Educational Resources Information Center (ERIC) indexes. Entries were published between 1972 and 1975. The bibliography is divided into nine sections: theory and research; social studies materials; environment, land use, and…

Eric Boe and Bob Behnken Dragon Tour

NASA Image and Video Library

2017-03-08

During a tour of SpaceX headquarters in Hawthorne, California, commercial crew astronauts Eric Boe, left, and Bob Behnken view the Crew Dragon on March 8, 2017. Crew Dragon is being developed and manufactured in partnership with NASA's Commercial Crew Program to return human spaceflight capabilities to the U.S.

The User Interface of ERIC on the Macintosh: A Qualitative Study of Novice Users.

ERIC Educational Resources Information Center

Thomas, Patricia

The experience of novice users searching SilverPlatter's ERIC CD-ROM on the Macintosh was studied. Ten students from an introductory master's level course in library and information science were recruited as volunteer subjects. Subjects were asked to complete a search on the ERIC CD-ROM; and data were collected via observations, a think-aloud…

RAPD- and ERIC-Based Typing of Clinical and Environmental Pseudomonas aeruginosa Isolates.

PubMed

Auda, Ibtesam Ghadban; Al-Kadmy, Israa M S; Kareem, Sawsan Mohammed; Lafta, Aliaa Khyuon; A'Affus, Mustafa Hussein Obeid; Khit, Ibrahim Abd Aloahd; Al Kheraif, Abdulaziz Abdullah; Divakar, Darshan Devang; Ramakrishnaiah, Ravikumar

2017-03-01

Pseudomonas aeruginosa is a major cause of nosocomial infection in children and adults, resulting in significant morbidity and mortality due to its ability to acquire drug resistance. The ability of P. aeruginosa in the environment to cause infection in individuals has been reported previously; henceforth, surveillance of the emergence and transmission of P. aeruginosa strains among patients is important for infection control in a clinical setup. Various gene-typing methods have been used for epidemiological typing of P. aeruginosa isolates for the purpose of surveillance. In this work, the suitability and comparability of two typing methods, enterobacterial repetitive intergenic consensus (ERIC)-PCR and random amplification of polymorphic DNA (RAPD)-PCR fingerprinting, were studied to characterize P. aeruginosa strains isolated from clinical and environmental sources. Forty-four clinical and environmental bacterial isolates of P. aeruginosa were collected between October 2015 and January 2016. DNA extraction, ERIC-PCR and RAPD-PCR, agarose gel electrophoresis, and phylogenetic analyses were carried using the unweighted pair-group method with mean. RAPD typing revealed less clonality among clinical isolates, whereas the ERIC method showed greater similarity in comparison with RAPD. Environmental isolates, however, showed greater similarity using RAPD compared with ERIC typing. With only a few exceptions, most clinical isolates were distinct from environmental isolates, irrespective of the typing method. In conclusion, both the RAPD and ERIC typing methods proved to be good tools in understanding clonal diversity. The results also suggest that there is no relationship between clinical and environmental isolates. The absence of clonality among the clinical isolates may indicate that most P. aeruginosa infection cases could be endemic and not epidemic and that endemic infections may be due to nonclonal strains of P. aeruginosa.

JAN transistor and diode characterization test program

NASA Technical Reports Server (NTRS)

Takeda, H.

1977-01-01

A statistical summary of electrical characterization was performed on JAN diodes and transistors. Parameters are presented with test conditions, mean, standard deviation, lowest reading, 10% point, 90% point and highest reading.

La Disciplina Positiva (Positive Discipline). ERIC Digest.

ERIC Educational Resources Information Center

ERIC Clearinghouse on Elementary and Early Childhood Education, Urbana, IL.

This ERIC Digest suggests methods and language that can be used in handling difficult, but common, situations involving young children. The digest explains 12 methods of disciplining children that promote children's self-worth. These methods are: (1) showing children that the reasons for their actions are understood; (2) stating reasons; (3)…

Online Public Access Catalogs. ERIC Fact Sheet.

ERIC Educational Resources Information Center

Cochrane, Pauline A.

A listing is presented of 17 documents in the ERIC database concerning the Online Catalog (sometimes referred to as OPAC or Online Public Access Catalog), a computer-based and supported library catalog designed for patron use. The database usually represents recent acquisitions and often contains information about books on order and items in…

Information Technology in Education: The Best of ERIC.

ERIC Educational Resources Information Center

Ely, Donald P.

This publication highlights 48 recent ERIC listings which help to explain the variety of emerging technologies for the delivery of information in educational settings. Specific technologies addressed include cable television, electronic mail, satellite communication, teleconferencing, videodisc, and videotex. Entries were selected for inclusion…

Chlorophyll and carotenoid pigments in solar saltern microbial mats

NASA Astrophysics Data System (ADS)

Villanueva, Joan; Grimalt, Joan O.; de Wit, Rutger; Keely, Brendan J.; Maxwell, James R.

1994-11-01

The distributions of carotenoids, chlorophylls, and their degradation products have been studied in two microbial mat systems developed in the calcite and calcite/gypsum evaporite domains of a solar saltern system. Phormidium valderianum and Microcoleus chthonoplastes are the dominant cyanobacterial species, respectively, and large amounts of Chloroflexus-like bacteria occur in the carbonate/gypsum mat. In both systems, the major pigments are chlorophyll a, zeaxanthin, β-carotene and myxoxanthophyll, which originate from these mat-building cyanobacteria. This common feature contrasts with differences in other pigments that are specific for each mat community. Thus, chlorophyll c and fucoxanthin, reflecting diatom inputs, are only found in the calcite mat, whereas the calcite/gypsum mat contains high concentrations of bacteriochlorophylls c produced by the multicellular green filamentous bacteria. In both cases, the depth concentration profiles (0-30 and 0-40 mm) show a relatively good preservation of the cyanobacterial carotenoids, zeaxanthin, β-carotene, myxoxanthophyll, and echinenone. This contrasts with the extensive biodegradation of cyanobacterial remains observed microscopically. Fucoxanthin in the calcite mat is also transformed at a faster rate than the cyanobacterial carotenoids. Chlorophyll a, the major pigment in both mats, exhibits different transformation pathways. In the calcite/gypsum mat, it is transformed via C-13 2 carbomethoxy defunctionalization prior to loss of the phytyl chain, leading to the formation of pyrophaeophytin a and, subsequently, pyrophaeophorbide a. On the other hand, the occurrence of the enzyme chlorophyllase, attributed to diatoms in the calcite mat, gives rise to extensive phytyl hydrolysis, with the formation of chlorophyllide a, pyrophaeophorbide a and, in minor proportion, phaeophorbide a. Studies of the sources of the photosynthetic pigments and of their transformation pathways in such simplified ecosystems provide a

Spatial patterns of cyanobacterial mat growth on sand ripples

NASA Astrophysics Data System (ADS)

Mariotti, G.; Klepac-Ceraj, V.; Perron, J. T.; Bosak, T.

2016-02-01

Photosynthetic microbial mats produce organic matter, cycle nutrients, bind pollutants and stabilize sediment in sandy marine environments. Here, we investigate the influence of bedforms and wave motion on the growth rate, composition and spatial variability of microbial mats by growing cyanobacterial mats on a rippled bed of carbonate sand in a wave tank. The tank was forced with an oscillatory flow with velocities below the threshold for sediment motion yet able to induce a porewater flow within the sediment. Different spatial patterns developed in mats depending on the initial biochemistry of the water medium. When growing in a medium rich in nitrogen, phosphorous and micronutrients, mats grew faster on ripple troughs than on ripple crests. After two months, mats covered the bed surface uniformly, and the microbial communities on the crests and in the troughs had similar compositions. Differences in bed shear stress and nutrient availability between crests and troughs were not able to explain the faster growth in the troughs. We hypothesize that this growth pattern is due to a "strainer" effect, i.e. the suspended bacteria from the inoculum were preferentially delivered to troughs by the wave-induced porewater flow. In the experiments initiated in a medium previously used up by a microbial mat and thus depleted in nutrients, mats grew preferentially on the ripple crests. This spatial pattern persisted for nearly two years, and the microbial composition on troughs and crests was different. We attribute this pattern to the upwelling of porewater in the crests, which increased the delivery of nutrients from sediment to the cyanobacteria on the bed surface. Thus, the macroscopic patterns formed by photosynthetic microbial mats on sand ripples may be used to infer whether mats are nutrient-limited and whether they are recently colonized or older than a month.

Development of kenaf mat for slope stabilization

NASA Astrophysics Data System (ADS)

Ahmad, M. M.; Manaf, M. B. H. Ab; Zainol, N. Z.

2017-09-01

This study focusing on the ability of kenaf mat to act as reinforcement to laterite compared to the conventional geosynthetic in term of stabilizing the slope. Kenaf mat specimens studied in this paper are made up from natural kenaf fiber with 3mm thickness, 150mm length and 20mm width. With the same size of specimens, geosynthetic that obtain from the industry are being tested for both direct shear and tensile tests. Plasticity index of the soil sample used is equal to 13 which indicate that the soil is slightly plastic. Result shows that the friction angle of kenaf mat is higher compared to friction between soil particles itself. In term of resistance to tensile load, the tensile strength of kenaf mat is 0.033N/mm2 which is lower than the tensile strength of geosynthetic.

Communications Skills. The Best of ERIC, Number 39.

ERIC Educational Resources Information Center

ERIC Clearinghouse on Educational Management, Eugene, OR.

The twelve items in this annotated bibliography are entries in the ERIC system concerning communication between principals and teachers, principals and students, and managers and subordinates. Research studies cited center on organizational communications and decision-making processes and structures, the importance of proper leave-taking…

Measuring Attitudes Toward Reading. An Annotated ERIC Bibliography.

ERIC Educational Resources Information Center

Hahn, Christine T., Comp.

This 30-item annotated bibliography provides access to information concerning the development and use of tests and procedures for evaluating student attitudes toward reading. Based upon a computer search of five data bases--Educational Resources Information Center (ERIC), Psychological Abstracts, Exceptional Child Education Abstracts, Sociological…

The Korean War: An ERIC/ChESS Sample.

ERIC Educational Resources Information Center

Pinhey, Laura A.

2000-01-01

Provides a list of teaching materials and general background documents about the Korean War from the ERIC database. Offers directions for obtaining the full text of materials about the division of South and North Korea, the geography of Korea, and South Korea's economic development. (CMK)

Are floating algal mats a refuge from hypoxia for estuarine invertebrates?

PubMed Central

Knysh, Kyle M.; Theriault, Emma F.; Pater, Christina C.; Courtenay, Simon C.; van den Heuvel, Michael R.

2017-01-01

Eutrophic aquatic habitats are characterized by the proliferation of vegetation leading to a large standing biomass that upon decomposition may create hypoxic (low-oxygen) conditions. This is indeed the case in nutrient impacted estuaries of Prince Edward Island, Canada, where macroalgae, from the genus Ulva, form submerged ephemeral mats. Hydrological forces and gases released from photosynthesis and decomposition lead to these mats occasionally floating to the water’s surface, henceforth termed floating mats. Here, we explore the hypothesis that floating mats are refugia during periods of sustained hypoxia/anoxia and examine how the invertebrate community responds to it. Floating mats were not always present, so in the first year (2013) sampling was attempted monthly and limited to when both floating and submerged mats occurred. In the subsequent year sampling was weekly, but at only one estuary due to logistical constraints from increased sampling frequency, and was not limited to when both mat types occurred. Water temperature, salinity, and pH were monitored bi-weekly with dissolved oxygen concentration measured hourly. The floating and submerged assemblages shared many of the same taxa but were statistically distinct communities; submerged mats tended to have a greater proportion of benthic animals and floating mats had more mobile invertebrates and insects. In 2014, sampling happened to occur in the weeks before the onset of anoxia, during 113 consecutive hours of sustained anoxia, and for four weeks after normoxic conditions returned. The invertebrate community on floating mats appeared to be unaffected by anoxia, indicating that these mats may be refugia during times of oxygen stress. Conversely, there was a dramatic decrease in animal abundances that remained depressed on submerged mats for two weeks. Cluster analysis revealed that the submerged mat communities from before the onset of anoxia and four weeks after anoxia were highly similar to each other

Spatially-resolved carbon flow through a hypersaline phototrophic microbial mat

NASA Astrophysics Data System (ADS)

Moran, J.; Lindemann, S. R.; Cory, A. B.; Courtney, S.; Cole, J. K.; Fredrickson, J.

2013-12-01

Hot Lake is a hypersaline, meromictic lake located in an endorheic basin in north-central Washington. Low annual rainfall and high evaporation rates contribute to the lake's high salinity. The predominant dissolved salt is magnesium sulfate, of which monimolimnion waters may seasonally exceed 2 M concentrations. Induced by its high salinity and meromictic nature, Hot Lake displays an inverse thermal gradient with deep horizons seasonally exceeding 50 °C. Despite extreme conditions, dense benthic microbial mats composed of cyanobacteria, anoxygenic photoheterotrophs, and bacterial heterotroph populations develop in the lake. These mats can exceed 1 cm in thickness and display vertical stratification in color due to bacterial pigmentation. Typical mat stratification includes an orange surface layer underlain by green and purple layers at increasing depth. Carbonates, including aragonite and magnesite, are observed within the mat and their formation is likely induced or influenced by microbial metabolic activities and associated pH excursions. We are exploring the role Hot Lake's microbial mats play in carbon cycling. Cyanobacteria are the dominant CO2-fixing organisms in the mat and we seek to understand the spatial and metabolic controls on how the carbon initially fixed by mat cyanobacteria is transferred to associated heterotrophic populations spread throughout the mat strata. Secondly, we seek to understand the overall net carbon balance of the mat through a growing season. We are using a stable isotope probing approach for assessing carbon uptake and migration through representative mat samples. We performed a series of ex situ incubations of freshly harvested mat samples in lake water amended with 13C-labeled bicarbonate or substrates commonly consumed by heterotrophs (including acetate and glucose) and using multiple stable isotope techniques to track label uptake, residence time, remineralization, and location within the mat. In addition to bulk isotope

Teaching Critical Reading through Literature. ERIC Digest.

ERIC Educational Resources Information Center

Collins, Norma Decker

Noting that it is only within the last decade that schools have begun to identify ways to optimize language use to promote higher level thinking, this ERIC Digest focuses on developing thinking skills in reading. The digest discusses the impetus for critical reading, the use of children's literature as a tool for teaching thinking skills, a…

Eric Boe and Bob Behnken Dragon Tour

NASA Image and Video Library

2017-03-08

During a tour of SpaceX headquarters in Hawthorne, California, commercial crew astronauts Bob Behnken, left, and Eric Boe participate in joint test team training using mockup components of the Crew Dragon on March 8, 2017. Crew Dragon is being developed and manufactured in partnership with NASA's Commercial Crew Program to return human spaceflight capabilities to the U.S.

Nitrogen cycle in microbial mats: completely unknown?

NASA Astrophysics Data System (ADS)

Coban, O.; Bebout, B.

2015-12-01

Microbial mats are thought to have originated around 3.7 billion years ago, most likely in the areas around submarine hydrothermal vents, which supplied a source of energy in the form of reduced chemical species from the Earth's interior. Active hydrothermal vents are also believed to exist on Jupiter's moon Europa, Saturn's moon Enceladus, and on Mars, earlier in that planet's history. Microbial mats have been an important force in the maintenance of Earth's ecosystems and the first photosynthesis was also originated there. Microbial mats are believed to exhibit most, if not all, biogeochemical processes that exist in aquatic ecosystems, due to the presence of different physiological groups of microorganisms therein. While most microbially mediated biogeochemical transformations have been shown to occur within microbial mats, the nitrogen cycle in the microbial mats has received very little study in spite of the fact that nitrogen usually limits growth in marine environments. We will present the first results in the determination of a complete nitrogen budget for a photosynthetic microbial mat. Both in situ sources and sinks of nitrogen in photosynthetic microbial mats are being measured using stable isotope techniques. Our work has a particular focus on recently described, but poorly understood, processes, e.g., anammox and dissimilatory nitrate reduction, and an emphasis on understanding the role that nitrogen cycling may play in generating biogenic nitrogen isotopic signatures and biomarker molecules. Measurements of environmental controls on nitrogen cycling should offer insight into the nature of co-evolution of these microbial communities and their planets of origin. Identifying the spatial (microscale) as well as temporal (diel and seasonal) distribution of nitrogen transformations, e.g., rates of nitrification and denitrification, within mats, particularly with respect to the distribution of photosynthetically-produced oxygen, is anticipated. The results

Nonwoven glass fiber mat reinforces polyurethane adhesive

NASA Technical Reports Server (NTRS)

Roseland, L. M.

1967-01-01

Nonwoven glass fiber mat reinforces the adhesive properties of a polyurethane adhesive that fastens hardware to exterior surfaces of aluminum tanks. The mat is embedded in the uncured adhesive. It ensures good control of the bond line and increases the peel strength.

Microbial mats and the early evolution of life

NASA Technical Reports Server (NTRS)

Des Marais, D. J.

1990-01-01

Microbial mats have descended from perhaps the oldest and most widespread biological communities known. Mats harbor microbes that are crucial for studies of bacterial phylogeny and physiology. They illustrate how several oxygen-sensitive biochemical processes have adapted to oxygen, and they show how life adapted to dry land long before the rise of plants. The search for the earliest grazing protists and metazoa in stromatolites is aided by observations of mats: in them, organic compounds characteristic of ancient photosynthetic protists can be identified. Recent mat studies suggest that the 13C/12C increase observed over geological time in stromatolitic organic matter was driven at least in part by a long-term decline in atmospheric carbon dioxide levels.

Vandalism Prevention. The Best of ERIC, Number 20.

ERIC Educational Resources Information Center

ERIC Clearinghouse on Educational Management, Eugene, OR.

Twelve publications in the ERIC system were reexamined and more detailed annotations written for this booklet. The approaches to vandalism prevention cited range from a U.S. Senate committee attempting to measure the cost of school vandalism nationwide to measures taken by individual school systems. (MLF)

The Industrial Revolution: An ERIC/ChESS Sample.

ERIC Educational Resources Information Center

Pinhey, Laura A.

2000-01-01

Provides a list, from the ERIC database, of teaching materials and background information on the Industrial Revolution. Specific topics include life in Lowell (Massachusetts), the global impact of the Industrial Revolution, and England's Industrial Revolution. Offers directions for obtaining the full text of these materials. (CMK)

Modeling for Ship Power System Emulation

DTIC Science & Technology

2009-05-08

oscilloscope output. Also determines Tdp and Tdpp . clear all load w6inertia_JAN19.mat; % radial speed profile from JAN19_6.mat wreal=f3...Known value. See Appendix I. % Xdp, Xdpp, Tdp, and Tdpp are estimated from this program (trial and % error) Xdp = 1.7...Match Xdp, Xdpp, Tdp, and Tdpp to oscope data Xdpp = .81216; Tdp = 45e-3; Tdpp =15e-3; ib = []; % Capture classical

Maté: a risk factor for oral and oropharyngeal cancer.

PubMed

Goldenberg, David

2002-10-01

Maté is a tea-like beverage consumed mainly in Argentina, Uruguay, Paraguay, southern Brazil and to a lesser degree in other areas of the world such as Germany, Syria, Lebanon and Northern Israel. It is brewed from the dried leaves and stemlets of the perennial tree Ilex paraguarensis ("yerba mate") a species that belongs to the Aquifoliaceae family. Maté consumption has been associated with an increased rate of oral and oropharyngeal cancers. The purpose of this study is to review the literature and discuss the role of Maté consumption in the development of oral and oropharyngeal cancer and the potential carcinogenic mechanisms. A review of the relevant literature linking Maté consumption with oral and oropharyngeal cancer and the carcinogenicity of Maté was performed. The search was performed using Medline, library catalogues, OCLC first search and ISI web of science databases. Case control studies on Maté drinking populations and, in vivo and in vitro studies on the carcinogenicity of Maté were reviewed. The populations reviewed in many of these studies also used alcohol and tobacco products confounding the influence of Maté as an independent risk factor. There is evidence in the literature that Maté consumption is in itself carcinogenic and plays a role in the development of cancers of the oral cavity and oropharynx. Although the exact mechanism of carcinogenesis is still unknown, available information suggests that Maté drinking should be considered one of the risk factors for oral and oropharyngeal cancer.

Fast releasing oral electrospun PVP/CD nanofiber mats of taste-masked meloxicam.

PubMed

Samprasit, Wipada; Akkaramongkolporn, Prasert; Ngawhirunpat, Tanasait; Rojanarata, Theerasak; Kaomongkolgit, Ruchadaporn; Opanasopit, Praneet

2015-06-20

Fast release and taste masking of meloxicam (MX)-loaded polyvinylpyrrolidone (PVP)/cyclodextrin (CD) nanofiber mats were developed using an electrospinning process. CDs were blended to improve the stability of the mats. The morphology and diameter of the mats were determined using scanning electron microscopy (SEM); physical and mechanical properties were also studied. The MX content, disintegration time, MX release and cytotoxicity of the mats were investigated. In vivo studies were also performed in healthy human volunteers. The results indicated that the mats were successfully prepared with fiber in the nanometer range. MX was well incorporated into the mats, with an amorphous form. The mats showed suitable tensile strength. CDs improved the physical stability by their cage-like supramolecular structure to protect from humidity and moisture, and create bead free nanofiber mats. The nanofiber mats with CDs were physically stable without any hygroscopicity and fusion. A fast disintegration and release of MX was achieved. Moreover, this mat released MX faster than the MX powder and commercial tablets. The cytotoxicity test revealed that mats were safe for a 5-min incubation. The disintegration studies indicated that in vivo disintegration agreed with the in vitro studies; the mat rapidly disintegrated in the mouth. The less bitter of MX was occurred in the mats that incorporated CD, menthol and aspartame. In addition, this mat was physical stable for 6 months. The results suggest that these mats may be a good candidate for fast dissolving drug delivery systems of bitter drugs to increase the palatability of dosage forms. Copyright © 2015 Elsevier B.V. All rights reserved.

Geosynthetic Reinforcement of Sand-Mat Layer above Soft Ground

PubMed Central

Park, Jong-Beom; Park, Hyun-Soo; Kim, Daehyeon

2013-01-01

In order to improve the bearing capacity of soft ground for the purpose of getting trafficability of construction vehicles, the reinforcement of geosynthetics for sand-mat layers on soft ground has often been used. As the strength of the geosynthetics increases, and the sand-mat system becomes stronger, the bearing capacity of sand-mat systems will be increased. The depths of geosynthetics, reinforced in sand-mat layers, were varied with respect to the width of footing. The tensile strengths of geosynthetics were also varied to evaluate the effect of reinforcement on the bearing capacity of soft ground. The dispersion angles, with varying sand-mat thicknesses, were also determined in consideration of the tensile strength of geosynthetics and the depths of reinforcement installations. The bearing capacity ratios, with the variation of footing width and reinforced embedment depth, were determined for the geosynthetics-only, reinforced soft ground, 1-layer sand-mat system and 2-layer sand-mat system against the non-reinforced soft ground. From the test results of various models, a principle that better explains the concept of geosynthetic reinforcement has been found. On the basis of this principle, a new bearing capacity equation for practical use in the design of geosynthetically reinforced soft ground has been proposed by modifying Yamanouchi’s equation. PMID:28788392

Design and Construction of Mat Foundations

DTIC Science & Technology

1989-11-01

column loads indicates the effectiveness of stiffening beams in spreading applied loads ... beams centered on rows of columns , (3) a shear and moment diagram may be constructed assuming that the column loads are point loads , (4) the mat depth...flexible consisting of precast concrete panels on a structural steel frame. Column loads , Figure 48, lead to an average pressure of 1.4 ksf. The mat

Starting and Operating a Child Care Center. ERIC/EECE Report.

ERIC Educational Resources Information Center

Cesarone, Bernard

2001-01-01

Reviews ERIC documents and journal articles that discuss various issues related to starting, operating, and marketing a child care center. Annotations include center and family care operations. (Author/DLH)

Full-Day or Half-Day Kindergarten? ERIC Digest.

ERIC Educational Resources Information Center

Rothenberg, Dianne

This ERIC Digest examines how changing family patterns have affected the full-day/half-day kindergarten issue, discussing why schools are currently considering alternative scheduling and describing the advantages and disadvantages of each type of program. The following changing family patterns affecting the choice of full-day kindergarten programs…

Metabolic potential of lithifying cyanobacteria-dominated thrombolitic mats.

PubMed

Mobberley, Jennifer M; Khodadad, Christina L M; Foster, Jamie S

2013-11-01

Thrombolites are unlaminated carbonate deposits formed by the metabolic activities of microbial mats and can serve as potential models for understanding the molecular mechanisms underlying the formation of lithifying communities. To assess the metabolic complexity of these ecosystems, high throughput DNA sequencing of a thrombolitic mat metagenome was coupled with phenotypic microarray analysis. Functional protein analysis of the thrombolite community metagenome delineated several of the major metabolic pathways that influence carbonate mineralization including cyanobacterial photosynthesis, sulfate reduction, sulfide oxidation, and aerobic heterotrophy. Spatial profiling of metabolite utilization within the thrombolite-forming microbial mats suggested that the top 5 mm contained a more metabolically diverse and active community than the deeper within the mat. This study provides evidence that despite the lack of mineral layering within the clotted thrombolite structure there is a vertical gradient of metabolic activity within the thrombolitic mat community. This metagenomic profiling also serves as a foundation for examining the active role individual functional groups of microbes play in coordinating metabolisms that lead to mineralization.

Diversity and stratification of archaea in a hypersaline microbial mat.

PubMed

Robertson, Charles E; Spear, John R; Harris, J Kirk; Pace, Norman R

2009-04-01

The Guerrero Negro (GN) hypersaline microbial mats have become one focus for biogeochemical studies of stratified ecosystems. The GN mats are found beneath several of a series of ponds of increasing salinity that make up a solar saltern fed from Pacific Ocean water pumped from the Laguna Ojo de Liebre near GN, Baja California Sur, Mexico. Molecular surveys of the laminated photosynthetic microbial mat below the fourth pond in the series identified an enormous diversity of bacteria in the mat, but archaea have received little attention. To determine the bulk contribution of archaeal phylotypes to the pond 4 study site, we determined the phylogenetic distribution of archaeal rRNA gene sequences in PCR libraries based on nominally universal primers. The ratios of bacterial/archaeal/eukaryotic rRNA genes, 90%/9%/1%, suggest that the archaeal contribution to the metabolic activities of the mat may be significant. To explore the distribution of archaea in the mat, sequences derived using archaeon-specific PCR primers were surveyed in 10 strata of the 6-cm-thick mat. The diversity of archaea overall was substantial albeit less than the diversity observed previously for bacteria. Archaeal diversity, mainly euryarchaeotes, was highest in the uppermost 2 to 3 mm of the mat and decreased rapidly with depth, where crenarchaeotes dominated. Only 3% of the sequences were specifically related to known organisms including methanogens. While some mat archaeal clades corresponded with known chemical gradients, others did not, which is likely explained by heretofore-unrecognized gradients. Some clades did not segregate by depth in the mat, indicating broad metabolic repertoires, undersampling, or both.

OTIS Basic Index Access System (OBIAS); A System for Retrieval of Information From the ERIC and CIJE Data Bases Utilizing a Direct Access Inverted Index of Descriptors and a Reformatted Direct Access ERIC-CIJE File.

ERIC Educational Resources Information Center

Bracken, Paula

The OTIS Basic Index Access System (OBIAS) for searching the ERIC data base is described. This system offers two advantages over the previous system. First, search time has been halved, reducing the cost per search to an estimated $10 on a batch basis. Second, the "OTIS ERIC Descripter Catalog" which contains all descriptors used in the…

MatLab Programming for Engineers Having No Formal Programming Knowledge

NASA Technical Reports Server (NTRS)

Shaykhian, Linda H.; Shaykhian, Gholam Ali

2007-01-01

MatLab is one of the most widely used very high level programming languages for Scientific and engineering computations. It is very user-friendly and needs practically no formal programming knowledge. Presented here are MatLab programming aspects and not just the MatLab commands for scientists and engineers who do not have formal programming training and also have no significant time to spare for learning programming to solve their real world problems. Specifically provided are programs for visualization. Also, stated are the current limitations of the MatLab, which possibly can be taken care of by Mathworks Inc. in a future version to make MatLab more versatile.

ERB master archival tape specification no. T 134081 ERB MAT, revision 1

NASA Technical Reports Server (NTRS)

1984-01-01

The Earth radiation budget (ERB)MAT tapes are generated by the ERB MATGEN software using the IBM 3081 computer system operated by the Science and Applications Computer Center at Goddard Space Flight Center. All MAT's are 9-track and MAT data are in ascending time order. The gross tape format for NIMBUS year-1 and year-2 MAT's is different from the format of MAT's starting with year-3. The MATs from the first two years are to contain one day's worth of data while all other MATs are to contain multiple day's worth of data stacked onto the tapes.

Computer-Based Education. The Best of ERIC, 1988.

ERIC Educational Resources Information Center

McLaughlin, Pamela

This annotated bibliography provides an overview of literature entered into the ERIC database in 1988 on computer use in elementary and secondary education, adult education, and special education. The first of four sections provides a list of overview documents on: computer-assisted instruction. Focusing on special applications, the second section…

Resources for Using a Global Approach in Elementary Social Studies. TeachERIC Resource Series, No. 2.

ERIC Educational Resources Information Center

Social Science Education Consortium, Inc., Boulder, CO.

This annotated bibliography, one of four separate resources in the "Teach ERIC Resource Series," cites materials that will help elementary teachers incorporate a global approach into social studies instruction. All materials listed are available through the ERIC system and in journal articles. The purpose of the Series is to help familiarize…

Jan Tschichold and the Language of Modernism.

ERIC Educational Resources Information Center

Storkerson, Peter

1996-01-01

States that in "The New Typography," Jan Tschichold explicates a functionalist and information-based theory of typographic design and demonstrates its application in numerous typographic examples of varied genres. Outlines Tschichold's typographic position; analyzes his style of visual communication; and considers subsequent developments…

Method for production of carbon nanofiber mat or carbon paper

DOEpatents

Naskar, Amit K.

2015-08-04

Method for the preparation of a non-woven mat or paper made of carbon fibers, the method comprising carbonizing a non-woven mat or paper preform (precursor) comprised of a plurality of bonded sulfonated polyolefin fibers to produce said non-woven mat or paper made of carbon fibers. The preforms and resulting non-woven mat or paper made of carbon fiber, as well as articles and devices containing them, and methods for their use, are also described.

Targeting S-adenosylmethionine biosynthesis with a novel allosteric inhibitor of Mat2A

DOE Office of Scientific and Technical Information (OSTI.GOV)

Quinlan, Casey L.; Kaiser, Stephen E.; Bolaños, Ben

S-Adenosyl-L-methionine (SAM) is an enzyme cofactor used in methyl transfer reactions and polyamine biosynthesis. The biosynthesis of SAM from ATP and L-methionine is performed by the methionine adenosyltransferase enzyme family (Mat; EC 2.5.1.6). Human methionine adenosyltransferase 2A (Mat2A), the extrahepatic isoform, is often deregulated in cancer. We identified a Mat2A inhibitor, PF-9366, that binds an allosteric site on Mat2A that overlaps with the binding site for the Mat2A regulator, Mat2B. Studies exploiting PF-9366 suggested a general mode of Mat2A allosteric regulation. Allosteric binding of PF-9366 or Mat2B altered the Mat2A active site, resulting in increased substrate affinity and decreased enzymemore » turnover. These data support a model whereby Mat2B functions as an inhibitor of Mat2A activity when methionine or SAM levels are high, yet functions as an activator of Mat2A when methionine or SAM levels are low. The ramification of Mat2A activity modulation in cancer cells is also described.« less

Teaching and Learning about the Earth. ERIC Digest.

ERIC Educational Resources Information Center

Lee, Hyonyong

This ERIC Digest investigates the earth and space science guidelines of the National Science Education Standards. These guidelines are frequently referred to as the earth system and include components such as plate tectonics, the water cycle, and the carbon cycle. This Digest describes the development of earth systems science and earth systems…

Contributions of ectomycorrhizal fungal mats to forest soil respiration

Treesearch

C. Phillips; L.A. Kluber; J.P. Martin; B.A. Caldwell; B.J. Bond

2012-01-01

Distinct aggregations of fungal hyphae and rhizomorphs, or “mats”, formed by some genera of ectomycorrhizal (EcM) fungi are common features of soils in coniferous forests of the Pacific Northwest. We measured in situ respiration rates of Piloderma mats and neighboring non-mat soils in an old-growth Douglas-fir forest in western Oregon to investigate whether there was...

Sulfate reducing bacteria in microbial mats: Changing paradigms, new discoveries

NASA Astrophysics Data System (ADS)

Baumgartner, L. K.; Reid, R. P.; Dupraz, C.; Decho, A. W.; Buckley, D. H.; Spear, J. R.; Przekop, K. M.; Visscher, P. T.

2006-03-01

Sulfate reducing bacteria (SRB) have existed throughout much of Earth's history and remain major contributors to carbon cycling in modern systems. Despite their importance, misconceptions about SRB are prevalent. In particular, SRB are commonly thought to lack oxygen tolerance and to exist only in anoxic environments. Through the last two decades, researchers have discovered that SRB can, in fact, tolerate and even respire oxygen. Investigations of microbial mat systems have demonstrated that SRB are both abundant and active in the oxic zones of mats. Additionally, SRB have been found to be highly active in the lithified zones of microbial mats, suggesting a connection between sulfate reduction and mat lithification. In the present paper, we review recent research on SRB distribution and present new preliminary findings on both the diversity and distribution of δ-proteobacterial SRB in lithifying and non-lithifying microbial mat systems. These preliminary findings indicate the unexplored diversity of SRB in a microbial mat system and demonstrate the close microspatial association of SRB and cyanobacteria in the oxic zone of the mat. Possible mechanisms and further studies to elucidate mechanisms for carbonate precipitation via sulfate reduction are also discussed.

ERIC Documents on Foreign Language Teaching and Linguistics: List Number 15. CAL-ERIC/CLL Series on Languages and Linguistics, No. 38.

ERIC Educational Resources Information Center

Eddy, Peter, Comp.; And Others

1976-01-01

This is the fifteenth in a series of catalogues of ERIC documents of interest to teachers and researchers in foreign languages and linguistics. The documents cited in the present list appeared in "Resources in Education" from January through June 1975. Titles are listed under the following headings and subheadings: (1) general: administration,…

Photosynthetic Microbial Mats are Exemplary Sources of Diverse Biosignatures (Invited)

NASA Astrophysics Data System (ADS)

Des Marais, D. J.; Jahnke, L. L.

2013-12-01

Marine cyanobacterial microbial mats are widespread, compact, self-contained ecosystems that create diverse biosignatures and have an ancient fossil record. Within the mats, oxygenic photosynthesis provides organic substrates and O2 to the community. Both the absorption and scattering of light change the intensity and spectral composition of incident radiation as it penetrates a mat. Some phototrophs utilize infrared light near the base of the photic zone. A mat's upper layers can become highly reduced and sulfidic at night. Counteracting gradients of O2 and sulfide shape the chemical environment and provide daily-contrasting microenvironments separated on a scale of a few mm. Radiation hazards (UV, etc.), O2 and sulfide toxicity elicit motility and other physiological responses. This combination of benefits and hazards of light, O2 and sulfide promotes the allocation of various essential mat processes between light and dark periods and to various depths in the mat. Associated nonphotosynthetic communities, including anaerobes, strongly influence many of the ecosystem's overall characteristics, and their processes affect any biosignatures that enter the fossil record. A biosignature is an object, substance and/or pattern whose origin specifically requires a biological agent. The value of a biosignature depends not only on the probability of life creating it, but also on the improbability of nonbiological processes producing it. Microbial mats create biosignatures that identify particular groups of organisms and also reveal attributes of the mat ecosystem. For example, branched hydrocarbons and pigments can be diagnostic of cyanobacteria and other phototrophic bacteria, and isoprenoids can indicate particular groups of archea. Assemblages of lipid biosignatures change with depth due to changes in microbial populations and diagenetic transformations of organic matter. The 13C/12C values of organic matter and carbonates reflect isotopic discrimination by particular

The New Philanthropist: Eric Schnell--Ohio State University

ERIC Educational Resources Information Center

Library Journal, 2005

2005-01-01

As head of information technology at the Prior Health Sciences Library, Eric Schnell likes to improve products that don't fully meet his library's purposes. His first major software product, the award-winning Prospero Electronic Delivery Project, is a web-based document delivery system designed to complement Ariel[R] by converting documents to a…

Biogeochemical cycles of carbon, sulfur, and free oxygen in a microbial mat

NASA Technical Reports Server (NTRS)

Canfield, Donald E.; Des Marais, David J.

1993-01-01

Complete budgets for carbon and oxygen have been constructed for cyanobacterial mats dominated by Microcoleus chthonoplastes from the evaporating ponds of a salt works. We infer from the data the various sinks for O2 as well as the sources of carbon for primary production. Although seasonal variability exists, a major percentage of the O2 produced during the day did not diffuse out of the mat but was used within the mat to oxidize both organic carbon and the sulfide produced by sulfate reduction. At night, most of the O2 that diffused into the mat was used to oxidize sulfide, with O2 respiration of minor importance. During the day, the internal mat processes of sulfate reduction and O2 respiration generated as much or more inorganic carbon (DIC) for primary production as diffusion into the mat. Oxygenic photosynthesis was the most important process of carbon fixation. At night, the DIC lost from the mat was mostly from sulfate reduction. Elemental fluxes across the mat/brine interface indicated that carbon with an oxidation state of greater than zero was taken up by the mat during the day and liberated from the mat at night. Overall, carbon with an average oxidation state of near zero accumulated in the mat. Both carbon fixation and carbon oxidation rates varied with temperature by a similar amount.

Argonne Director Eric Isaacs addresses the National Press Club

ScienceCinema

Eric Isaccs

2017-12-09

Argonne Director Eric Isaacs addresses the National Press Club on 9/15/2009. To build a national economy based on sustainable energy, the nation must first "reignite its innovation ecology," he said. Issacs makes the case for investing in science to secure America's future.

Argonne Director Eric Isaacs addresses the National Press Club

DOE Office of Scientific and Technical Information (OSTI.GOV)

Eric Isaccs

2009-09-17

Argonne Director Eric Isaacs addresses the National Press Club on 9/15/2009. To build a national economy based on sustainable energy, the nation must first "reignite its innovation ecology," he said. Issacs makes the case for investing in science to secure America's future.

Water flow and solute transport in floating fen root mats

NASA Astrophysics Data System (ADS)

Stofberg, Sija F.; EATM van der Zee, Sjoerd

2015-04-01

Floating fens are valuable wetlands, found in North-Western Europe, that are formed by floating root mats when old turf ponds are colonized by plants. These terrestrialization ecosystems are known for their biodiversity and the presence of rare plant species, and the root mats reveal different vegetation zones at a small scale. The vegetation zones are a result of strong gradients in abiotic conditions, including groundwater dynamics, nutrients and pH. To prevent irreversible drought effects such as land subsidence and mineralization of peat, water management involves import of water from elsewhere to maintain constant surface water levels. Imported water may have elevated levels of salinity during dry summers, and salt exposure may threaten the vegetation. To assess the risk of exposure of the rare plant species to salinity, the hydrology of such root mats must be understood. Physical properties of root mats have scarcely been investigated. We have measured soil characteristics, hydraulic conductivity, vertical root mat movement and groundwater dynamics in a floating root mat in the nature reserve Nieuwkoopse Plassen, in the Netherlands. The root mat mostly consists of roots and organic material, in which the soil has a high saturated water content, and strongly varies in its stage of decomposition. We have found a distinct negative correlation between degree of decomposition and hydraulic conductivity, similar to observations for bogs in the literature. Our results show that the relatively young, thin edge of the root mat that colonizes the surface water has a high hydraulic conductivity and floats in the surface water, resulting in very small groundwater fluctuations within the root mat. The older part of the root mat, that is connected to the deeper peat layers is hydrologically more isolated and the material has a lower conductivity. Here, the groundwater fluctuates strongly with atmospheric forcing. The zones of hydraulic properties and vegetation, appear to

BIOGEOCHEMICAL STUDIES OF PHOTOSYNTHETIC MICROBIAL MATS AND THEIR BIOTA

NASA Technical Reports Server (NTRS)

DesMarais, David; Discipulo, M.; Turk, K.; Londry, K. L.

2005-01-01

Photosynthetic microbial mats offer an opportunity to define holistic functionality at the millimeter scale. At the same time. their biogeochemistry contributes to environmental processes on a planetary scale. These mats are possibly direct descendents of the most ancient biological communities; communities in which oxygenic photosynthesis might have been invented. Mats provide one of the best natural systems to study how microbial populations associate to control dynamic biogeochemical gradients. These are self- sustaining, complete ecosystems in which light energy absorbed over a dial (24 hour) cycle drives the synthesis of spatially-organized, diverse biomass. Tightly-coupled microorganisms in the mat have specialized metabolisms that catalyze transformations of carbon, nitrogen, sulfur, and a host of other elements.

Professor Eric Can't See: A Project-Based Learning Case for Neurobiology Students.

PubMed

Ogilvie, Judith Mosinger; Ribbens, Eric

2016-01-01

"Professor Eric Can't See" is a semi-biographical case study written for an upper level undergraduate Neurobiology of Disease course. The case is integrated into a unit using a project-based learning approach to investigate the retinal degenerative disorder Retinitis pigmentosa and the visual system. Some case study scenes provide specific questions for student discussion and problem-based learning, while others provide background for student inquiry and related active learning exercises. The case was adapted from "'Chemical Eric' Can't See," and could be adapted for courses in general neuroscience or sensory neuroscience.

Dynamics of archaea at fine spatial scales in Shark Bay mat microbiomes

NASA Astrophysics Data System (ADS)

Wong, Hon Lun; Visscher, Pieter T.; White, Richard Allen, III; Smith, Daniela-Lee; Patterson, Molly M.; Burns, Brendan P.

2017-04-01

The role of archaea in microbial mats is poorly understood. Delineating the spatial distribution of archaea with mat depth will enable resolution of putative niches in these systems. In the present study, high throughput amplicon sequencing was undertaken in conjunction with analysis of key biogeochemical properties of two mats (smooth and pustular) from Shark Bay, Australia. One-way analysis of similarity tests indicated the archaeal community structures of smooth and pustular mats were significantly different (global R = 1, p = 0.1%). Smooth mats possessed higher archaeal diversity, dominated by Parvarchaeota. The methanogenic community in smooth mats was dominated by hydrogenotrophic Methanomicrobiales, as well as methylotrophic Methanosarcinales, Methanococcales, Methanobacteriales and Methanomassiliicoccaceae. Pustular mats were enriched with Halobacteria and Parvarchaeota. Key metabolisms (bacterial and archaeal) were measured, and the rates of oxygen production/consumption and sulfate reduction were up to four times higher in smooth than in pustular mats. Methane production peaked in the oxic layers and was up to seven-fold higher in smooth than pustular mats. The finding of an abundance of anaerobic methanogens enriched at the surface where oxygen levels were highest, coupled with peak methane production in the oxic zone, suggests putative surface anoxic niches in these microbial mats.

Daily Life in Japanese High Schools. ERIC Digest.

ERIC Educational Resources Information Center

Johnson, Marcia L.; Johnson, Jeffrey R.

This ERIC Digest asserts that the Japanese education system is one of the most influential agents molding Japanese youth. This influence is especially great due to the large amount of time students spend in schools. Six topics examine aspects of daily high school life: (1) Getting to School; (2) At School; (3) Extracurricular Activities; (4)…

Computer-Based Education: The Best of ERIC, 1989.

ERIC Educational Resources Information Center

McLaughlin, Pamela

This collection is designed for use by educators who need to make decisions about the use of microcomputers in schools, or who want to keep abreast of new developments in the field. The report provides an overview of the literature entered into the ERIC database in 1989 on computer use in elementary and secondary education, adult education, and…

Peace and Nuclear War. ERIC Digest No. 21.

ERIC Educational Resources Information Center

Zola, John; Zola, Jaye

This ERIC Digest examines the nature of peace and nuclear war education, rationales for its inclusion in public school programs, and ways to deal with the controversial nature of the topics. A distinction between peace education and nuclear war education is followed by a description of four basic themes offered as a rationale for peace and nuclear…

Biogeochemical cycles of carbon, sulfur, and free oxygen in a microbial mat

NASA Astrophysics Data System (ADS)

Canfield, Donald E.; Des Marais, David J.

1993-08-01

Complete budgets for carbon and oxygen have been constructed for cyanobacterial mats dominated by Microcoleus chthonoplastes from the evaporating ponds of a salt works located in Guerrero Negro, Baja California Sur, Mexico. Included in the budget are measured rates of O 2 production, sulfate reduction, and elemental exchange across the mat/brine interface, day and night, at various temperatures and times of the year. We infer from this data the various sinks for O 2, as well as the sources of carbon for primary production. To summarize, although seasonal variability exists, a major percentage of the O 2 produced during the day did not diffuse out of the mat but was used within the mat to oxidize both organic carbon and the sulfide produced by sulfate reduction. At night, most of the O 2 that diffused into the mat was used to oxidize sulfide, with O 2 respiration of minor importance. During the day, the internal mat processes of sulfate reduction and O 2 respiration generated as much or more inorganic carbon (DIC) for primary production as diffusion into the mat. Also, oxygenic photosynthesis was the most important process of carbon fixation, although anoxygenic photosynthesis may have been important at low light levels during some times of the year. At night, the DIC lost from the mat was mostly from sulfate reduction. Elemental fluxes across the mat/brine interface indicated that carbon with an oxidation state of greater than zero was taken up by the mat during the day and liberated from the mat at night. Overall, carbon with an average oxidation state of near zero accumulated in the mat. Both carbon fixation and carbon oxidation rates varied with temperature by a similar amount. These mats are thus closely coupled systems where rapid rates of photosynthesis both require and fuel rapid rates of heterotrophic carbon oxidation.

Processes of carbonate precipitation in modern microbial mats

NASA Astrophysics Data System (ADS)

Dupraz, Christophe; Reid, R. Pamela; Braissant, Olivier; Decho, Alan W.; Norman, R. Sean; Visscher, Pieter T.

2009-10-01

Microbial mats are ecosystems that arguably greatly affected the conditions of the biosphere on Earth through geological time. These laminated organosedimentary systems, which date back to > 3.4 Ga bp, are characterized by high metabolic rates, and coupled to this, rapid cycling of major elements on very small (mm-µm) scales. The activity of the mat communities has changed Earth's redox conditions (i.e. oxidation state) through oxygen and hydrogen production. Interpretation of fossil microbial mats and their potential role in alteration of the Earth's geochemical environment is challenging because these mats are generally not well preserved. Preservation of microbial mats in the fossil record can be enhanced through carbonate precipitation, resulting in the formation of lithified mats, or microbialites. Several types of microbially-mediated mineralization can be distinguished, including biologically-induced and biologically influenced mineralization. Biologically-induced mineralization results from the interaction between biological activity and the environment. Biologically-influenced mineralization is defined as passive mineralization of organic matter (biogenic or abiogenic in origin), whose properties influence crystal morphology and composition. We propose to use the term organomineralization sensu lato as an umbrella term encompassing biologically influenced and biologically induced mineralization. Key components of organomineralization sensu lato are the "alkalinity" engine (microbial metabolism and environmental conditions impacting the calcium carbonate saturation index) and an organic matrix comprised of extracellular polymeric substances (EPS), which may provide a template for carbonate nucleation. Here we review the specific role of microbes and the EPS matrix in various mineralization processes and discuss examples of modern aquatic (freshwater, marine and hypersaline) and terrestrial microbialites.

Trends in Library and Information Science: 1989. ERIC Digest.

ERIC Educational Resources Information Center

Eisenberg, Michael B.

Based on a content analysis of professional journals, conference proceedings, ERIC documents, annuals, and dissertations in library and information science, the following current trends in the field are discussed: (1) there are important emerging roles and responsibilities for information professionals; (2) the status and image of librarians…

Library Literacy Programs for English Language Learners. ERIC Digest.

ERIC Educational Resources Information Center

McMurrer, Eileen; Terrill, Lynda

This digest summarizes the history of public libraries and library literacy programs; describes current delivery models; and discusses initiatives in library literacy, profiling one successful public library program that serves adult English language learners and their families. (Adjunct ERIC Clearinghouse for ESL Literacy Education) (Author/VWL)

Fabrication of nanofiber mats from electrospinning of functionalized polymers

NASA Astrophysics Data System (ADS)

Oktay, Burcu; Kayaman-Apohan, Nilhan; Erdem-Kuruca, Serap

2014-08-01

Electrospinning technique enabled us to prepare nanofibers from synthetic and natural polymers. In this study, it was aimed to fabricate electrospun poly(vinyl alcohol) (PVA) based nanofibers by reactive electrospinning process. To improve endurance of fiber toward to many solvents, PVA was functionalized with photo-crosslinkable groups before spinning. Afterward PVA was crosslinked by UV radiation during electrospinning process. The nanofiber mats were characterized by scanning electron microscopy (SEM). The results showed that homogenous, uniform and crosslinked PVA nanofibers in diameters of about 200 nm were obtained. Thermal stability of the nanofiber mat was investigated with thermal gravimetric analysis (TGA). Also the potential use of this nanofiber mats for tissue engineering was examined. Osteosarcoma (Saos) cells were cultured on the nanofiber mats.

Direct piezoelectric responses of soft composite fiber mats

NASA Astrophysics Data System (ADS)

Varga, M.; Morvan, J.; Diorio, N.; Buyuktanir, E.; Harden, J.; West, J. L.; Jákli, A.

2013-04-01

Recently soft fiber mats electrospun from solutions of Barium Titanate (BT) ferroelectric ceramics particles and polylactic acid (PLA) were found to have large (d33 ˜ 1 nm/V) converse piezoelectric signals offering a myriad of applications ranging from active implants to smart textiles. Here, we report direct piezoelectric measurements (electric signals due to mechanical stress) of the BT/PLA composite fiber mats at several BT concentrations. A homemade testing apparatus provided AC stresses in the 50 Hz-1.5 kHz-frequency range. The piezoelectric constant d33 ˜ 0.5 nC/N and the compression modulus Y ˜ 104-105 Pa found are in agreement with the prior converse piezoelectric and compressibility measurements. Importantly, the direct piezoelectric signal is large enough to power a small LCD by simple finger tapping of a 0.15 mm thick 2-cm2 area mat. We propose using these mats in active Braille cells and in liquid crystal writing tablets.

Enzyme functionalized electrospun chitosan mats for antimicrobial treatment.

PubMed

Bösiger, Peter; Tegl, Gregor; Richard, Isabelle M T; Le Gat, Luce; Huber, Lukas; Stagl, Viktoria; Mensah, Anna; Guebitz, Georg M; Rossi, René M; Fortunato, Giuseppino

2018-02-01

This work presents electrospun chitosan mats, functionalized with glucose oxidase (GOX) to implement an in-situ hydrogen peroxide (H 2 O 2 ) generation system. The as spun CTS-PEO mats exhibited a smooth and homogenous morphology in combination with a high specific surface area (5.4m 2 /g) providing an excellent basis for further functionalization and subsequent glutaraldehyde crosslinking provided them with superior mechanical stability in aqueous environments. GOX was covalently immobilized, as proven by XPS, and resulted in activity recoveries between 20 and 40%. The functional mats generated a steady state concentration of ∼60μM H 2 O 2 per cm 2 which resulted in growth inhibition of E. coli and of S. aureus already after two hours of incubation. Additional cytotoxicity tests of the modified mats against mouse fibroblasts did not show an influence on the viability of the cells which proved it a functional biomaterial of great potential for biomedical applications. Copyright © 2017 Elsevier Ltd. All rights reserved.

Computer Applications in Education: The Best of ERIC 1990.

ERIC Educational Resources Information Center

McLaughlin, Pamela

This collection provides an overview of literature entered into the ERIC database in 1990 on computer applications in elementary and secondary education, adult education, and special education. The first of four sections contains a list of overview documents on computer assisted instruction. Focusing on special applications, the second section…

Dynamics of archaea at fine spatial scales in Shark Bay mat microbiomes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wong, Hon Lun; Visscher, Pieter T.; White, III, Richard Allen

Modern microbial mats provide remarkable insights into assembly, function and origin of complex microbial ecosystems. An excellent model of such systems is located in Shark Bay, Australia. Although bacteria have been extensively investigated in these communities, the role of archaea in microbial mats is poorly understood. Delineating the spatial distribution of archaea with mat depth will enable resolution of specific niches associated with this domain. In the present study, high throughput amplicon sequencing was undertaken in conjunction with key biogeochemical properties of two mat types (smooth and pustular). A total of 13,547,552 unfiltered sequences were obtained, and classified sequences weremore » affiliated to three archaeal and candidate phyla, Parvarchaeota, Euryarchaeota and Crenarchaeota. One way analysis of similarity tests (ANOSIM) indicated the archaeal community structures of smooth and pustular mats were significantly different (global R = 1, p = 0.1 %). Smooth mats possessed higher archaeal diversity, dominated by Parvarchaeota, followed by Thermoplasmata, Class marine benthic group B and Halobacteria. The methanogenic community in smooth mats was dominated by hydrogenotrophic Methanomicrobiales, as well as methylotrophic Methanosarcinales, Methanococcales, Methanobacteriales and Methanomassiliicoccaceae. Conversely, pustular mats were enriched with Halobacteria and Parvarchaeota. The rates of oxygen production/consumption as well as sulphate reduction were up to four times higher in smooth than in pustular mats. Methane production peaked in the oxic part of mats and was up to seven-fold higher in smooth than in pustular mats. Metabolic cooperation in putative surface anoxic niches is proposed to be key in efficient cycling of key nutrients in these systems.« less

Evaluation of polyacrylonitrile electrospun nano-fibrous mats as leukocyte removal filter media.

PubMed

Pourbaghi, Raha; Zarrebini, Mohammad; Semnani, Dariush; Pourazar, Abbasali; Akbari, Nahid; Shamsfar, Reihaneh

2018-07-01

Removal of leukocytes from blood products is the most effective means for elimination of undesirable side effects and prevention of possible reactions in recipients. Micro-fibrous mats are currently used for removal of leukocytes from blood. In this study, samples of electrospun nano-fibrous mats were produced. The performance of the produced electrospun nano-fibrous mats as means of leukocytes removal from fresh whole blood was both evaluated and compared with that of commercially available micro-fibrous mats. In order to produce the samples, polyacrylonitrile (PAN) nano-fibrous mats were made under different electrospinning conditions. Mean fiber diameter, pore characterization and surface roughness of the PAN nano-fibrous mats were determined using image processing technique. In order to evaluate the surface tension of the fabricated mats, water contact angle was measured. The leukocyte removal performance, erythrocytes recovery percent and hemolysis rate of the nano-fibrous mats were compared. The effectiveness of nano-fibrous mats in removing leukocyte was established using both scanning electron microscope and optical microscope. Results showed that for given weight, the fabricated nano-fibrous mats were not only more efficient but also more cost-effective than their commercial counterparts. Results confirmed that changes in mean fiber diameter, the number of layer and weight of each layer in the absence of any chemical reaction or physical surface modification, the fabricated nano-fibrous mats were able to remove 5-log of leukocytes. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 106B: 1759-1769, 2018. © 2017 Wiley Periodicals, Inc.

Dynamics of archaea at fine spatial scales in Shark Bay mat microbiomes

DOE PAGES

Wong, Hon Lun; Visscher, Pieter T.; White, III, Richard Allen; ...

2017-04-11

Modern microbial mats provide remarkable insights into assembly, function and origin of complex microbial ecosystems. An excellent model of such systems is located in Shark Bay, Australia. Although bacteria have been extensively investigated in these communities, the role of archaea in microbial mats is poorly understood. Delineating the spatial distribution of archaea with mat depth will enable resolution of specific niches associated with this domain. In the present study, high throughput amplicon sequencing was undertaken in conjunction with key biogeochemical properties of two mat types (smooth and pustular). A total of 13,547,552 unfiltered sequences were obtained, and classified sequences weremore » affiliated to three archaeal and candidate phyla, Parvarchaeota, Euryarchaeota and Crenarchaeota. One way analysis of similarity tests (ANOSIM) indicated the archaeal community structures of smooth and pustular mats were significantly different (global R = 1, p = 0.1 %). Smooth mats possessed higher archaeal diversity, dominated by Parvarchaeota, followed by Thermoplasmata, Class marine benthic group B and Halobacteria. The methanogenic community in smooth mats was dominated by hydrogenotrophic Methanomicrobiales, as well as methylotrophic Methanosarcinales, Methanococcales, Methanobacteriales and Methanomassiliicoccaceae. Conversely, pustular mats were enriched with Halobacteria and Parvarchaeota. The rates of oxygen production/consumption as well as sulphate reduction were up to four times higher in smooth than in pustular mats. Methane production peaked in the oxic part of mats and was up to seven-fold higher in smooth than in pustular mats. Metabolic cooperation in putative surface anoxic niches is proposed to be key in efficient cycling of key nutrients in these systems.« less

Cyanobacterial reuse of extracellular organic carbon in microbial mats

PubMed Central

Stuart, Rhona K; Mayali, Xavier; Lee, Jackson Z; Craig Everroad, R; Hwang, Mona; Bebout, Brad M; Weber, Peter K; Pett-Ridge, Jennifer; Thelen, Michael P

2016-01-01

Cyanobacterial organic matter excretion is crucial to carbon cycling in many microbial communities, but the nature and bioavailability of this C depend on unknown physiological functions. Cyanobacteria-dominated hypersaline laminated mats are a useful model ecosystem for the study of C flow in complex communities, as they use photosynthesis to sustain a more or less closed system. Although such mats have a large C reservoir in the extracellular polymeric substances (EPSs), the production and degradation of organic carbon is not well defined. To identify extracellular processes in cyanobacterial mats, we examined mats collected from Elkhorn Slough (ES) at Monterey Bay, California, for glycosyl and protein composition of the EPS. We found a prevalence of simple glucose polysaccharides containing either α or β (1,4) linkages, indicating distinct sources of glucose with differing enzymatic accessibility. Using proteomics, we identified cyanobacterial extracellular enzymes, and also detected activities that indicate a capacity for EPS degradation. In a less complex system, we characterized the EPS of a cyanobacterial isolate from ES, ESFC-1, and found the extracellular composition of biofilms produced by this unicyanobacterial culture were similar to that of natural mats. By tracing isotopically labeled EPS into single cells of ESFC-1, we demonstrated rapid incorporation of extracellular-derived carbon. Taken together, these results indicate cyanobacteria reuse excess organic carbon, constituting a dynamic pool of extracellular resources in these mats. PMID:26495994

Molecular Ecological and Stable Isotopic Studies of Nitrogen Fixation in Modern Microbial Mats

NASA Technical Reports Server (NTRS)

Bebout, B. M.; Crumbliss, L. L.; DesMarais, D. J.; Hogan, M. E.; Omoregie, E.; Turk, K. A.; Zehr, J. P.

2003-01-01

Nitrogen is usually the element limiting biological productivity in the marine environment. Microbial mats, laminated microbial communities analogous to some of the oldest forms of life on Earth, are often the sites of high rates of N fixation (the energetically expensive conversion of atmospheric dinitrogen into a biologically useful form). The N fixing enzyme nitrogenase is generally considered to be of ancient origin, and is widely distributed throughout the Bacterial and Archaeal domains of life, indicating an important role for this process over evolutionary time. The stable isotopic signature of N fixation is purportedly recognizable in organic matter (ancient kerogens as well as present-day microbial mats) as a delta (15)N(sub organic) near zero. We studied two microbial mats exhibiting different rates of N fixation in order to better understand the impact of N fixation on the delta (15)N (sub organic) of the mats, as well as what organisms are important in this process. Mats dominated by the cyanobacterium Microcoleus chthonoplastes grow in permanently submerged hypersaline salterns, and exhibit low rates of N fixation, whereas mats dominated by the cyanobacterium Lyngbya spp grow in an intertidal area, and exhibit rates of N fixation an order of magnitude higher. To examine successional stages in mat growth, both developing and established mats at each location were sampled. PCR and RT-PCR based approaches were used to identify, respectively, the organisms containing nifH (one of the genes that encode nitrogenase) as well as those expressing nifH in these mats. Both mats exhibited a distinct diel cycle of N fixation, with highest rates occurring at night. The delta (15)N(sub organic) of the subtidal Microcoleus mats is near zero whereas the delta (15)N(sub organic) is slightly more positive (+ 2-3%), in the intertidal Lyngbya mats, an interesting difference in view of the fact that overall rates of activity in the intertidal mats are much higher that those

Drug Testing. ERIC Digest Series Number EA 35.

ERIC Educational Resources Information Center

Klauke, Amy

The issue of drug testing is the focus of this ERIC Digest. Several aspects of drug testing discussed in question-and-answer format: (1) What is the current status of drug use in the schools? (2) What legal questions arise when schools consider drug testing? (3) How might drug testing be applied in a fair, economical, and legally safe manner? (4)…

A Parent's Guide to the ERIC Database. Where To Turn with Your Questions about Schooling. Revised Edition.

ERIC Educational Resources Information Center

Howley, Craig B.; And Others

This guide explains what the Educational Resources Information Center (ERIC) database is and how it can be used by parents to learn more about schooling and parenting. The guide also presents sample records of 55 documents in the ERIC database. The cited resources are particularly relevant to parents' concerns about meeting children's basic needs,…

State of the Art and Future Trends in Special Education 1980: An Analysis Using the ERIC Data Base.

ERIC Educational Resources Information Center

Cambel, Marion, Ed.

The report analyzes trends in research and programs in special education. Twelve reviewers from each of the divisions of The Council for Exceptional Children (CEC) reviewed abstracts of ERIC (Educational Resources Information Center) documents (project reports, research reports, and conference presentations). The ERIC documents resulted from a…

Children's Rights and Child Advocacy: An ERIC Abstract Bibliography.

ERIC Educational Resources Information Center

ERIC Clearinghouse on Early Childhood Education, Champaign, IL.

This abstract bibliography cites recent ERIC documents and journal articles concerning the rights of children--in relation to the home, the school and other institutions--and advocacy for children. Entries include resumes from Resources in Education (RIE), January 1974 through December 1977, and citations from Current Index to Journals in…

DSM-5 and ADHD - an interview with Eric Taylor.

PubMed

Taylor, Eric

2013-09-12

In this podcast we talk to Prof Eric Taylor about the changes to the diagnosis of Attention Deficit Hyperactivity Disorder (ADHD) in DSM-5 and how these changes will affect clinical practice. The podcast for this interview is available at: http://www.biomedcentral.com/sites/2999/download/Taylor.mp3.

Computer Applications in Education: The Best of ERIC 1991.

ERIC Educational Resources Information Center

McLaughlin, Pamela

This annotated bibliography is the sixth annual compilation of the abstracts of 228 documents added to the ERIC database during the year 1991 in the area of computer applications in elementary and secondary schools. The types of materials included are administrator guides, bibliographies, conference papers, evaluative reports, literature reviews,…

76 FR 39844 - Action Affecting Export Privileges; ERIC COHEN

Federal Register 2010, 2011, 2012, 2013, 2014

2011-07-07

... DEPARTMENT OF COMMERCE Bureau of Industry and Security Action Affecting Export Privileges; ERIC... continuing through and including on or about June 6, 2005, Cohen engaged in a transaction or took actions..., permission, or privilege granted, or to be granted, to Cohen. Fourth, Cohen agrees not to take any action or...

Locating Vocational Education Curriculum and Instructional Materials. ERIC Digest.

ERIC Educational Resources Information Center

Wagner, Judith O.

This digest provides a variety of sources for vocational education curricula, lesson plans, and other instructional materials. The section on networking includes listservs and World Wide Web sites that lead to curriculum resources and other valuable information. Access points to the ERIC database are listed, as are instructional materials labs and…

GETTING TO KNOW YOU. ERIC PASLAY.

PubMed

Rosenfeld, Cheryl A

2017-03-01

If you're a country music fan, you've probably heard of Eric Paslay; 33, a Nashville-based platinum-selling singer/songwriter. After starting to play guitar at age 15, Paslay knew by 18 that music was his path. In 2011, he signed with EMI Records Nashville, and since then he has had five number one hits, including four recorded by other artists such as Rascal Flatts as well as "Friday Night," the lead single from his self-titled debut album. His latest album, "Dressed in Black," includes the single "Angels in This Town."

Research on Bayes matting algorithm based on Gaussian mixture model

NASA Astrophysics Data System (ADS)

Quan, Wei; Jiang, Shan; Han, Cheng; Zhang, Chao; Jiang, Zhengang

2015-12-01

The digital matting problem is a classical problem of imaging. It aims at separating non-rectangular foreground objects from a background image, and compositing with a new background image. Accurate matting determines the quality of the compositing image. A Bayesian matting Algorithm Based on Gaussian Mixture Model is proposed to solve this matting problem. Firstly, the traditional Bayesian framework is improved by introducing Gaussian mixture model. Then, a weighting factor is added in order to suppress the noises of the compositing images. Finally, the effect is further improved by regulating the user's input. This algorithm is applied to matting jobs of classical images. The results are compared to the traditional Bayesian method. It is shown that our algorithm has better performance in detail such as hair. Our algorithm eliminates the noise well. And it is very effectively in dealing with the kind of work, such as interested objects with intricate boundaries.

Reduced Gas Cycling in Microbial Mats: Implications for Early Earth

NASA Technical Reports Server (NTRS)

Hoehler, Tori M.; Bebout, Brad M.; DesMarais, David J.; DeVincenzi, Donald L. (Technical Monitor)

2000-01-01

For more than half the history of life on Earth, biological productivity was dominated by photosynthetic microbial mats. During this time, mats served as the preeminent biological influence on earth's surface and atmospheric chemistry and also as the primary crucible for microbial evolution. We find that modern analogs of these ancient mat communities generate substantial quantities of hydrogen, carbon monoxide, and methane. Escape of these gases from the biosphere would contribute strongly to atmospheric evolution and potentially to the net oxidation of earth's surface; sequestration within the biosphere carries equally important implications for the structure, function, and evolution of anaerobic microbial communities within the context of mat biology.

MAT@USC Candidates and Latino English Language Learners

ERIC Educational Resources Information Center

Lomeli, Cynthia Leticia

2012-01-01

The purpose of this study was to further understand the perceptions of MAT@USC teacher candidates and how their perceptions and previous experiences affect the educational experiences of Latino English language learners. Three questions were developed to guide this study: (1) What are the perceptions of MAT@USC candidates in selected courses…

Eric Stahlberg Named to FCW’s Federal 100 | FNLCR Staging

Cancer.gov

Eric Stahlberg, Ph.D., director of high-performance computing at the Frederick National Lab, has been named one of FCW‘s Federal 100 for his work in predictive oncology and his role in the collaboration between the National Cancer Institute and the

Teaching about World War II: An ERIC/ChESS Sample.

ERIC Educational Resources Information Center

Schlene, Vickie L.

1991-01-01

Presents nine documents from the ERIC database dealing with teaching about World War II. Includes articles addressing the lessons of Pearl Harbor, the Holocaust, the wartime internment of Japanese Americans, industry's response to the war, and the moral lessons of Nazism. (SG)

Hypersaline Microbial Mat Lipid Biomarkers

NASA Technical Reports Server (NTRS)

Jahnke, Linda L.; Embaye, Tsegereda; Turk, Kendra A.; Summons, Roger E.

2002-01-01

Lipid biomarkers and compound specific isotopic abundances are powerful tools for studies of contemporary microbial ecosystems. Knowledge of the relationship of biomarkers to microbial physiology and community structure creates important links for understanding the nature of early organisms and paleoenvironments. Our recent work has focused on the hypersaline microbial mats in evaporation ponds at Guerrero Negro, Baja California Sur, Mexico. Specific biomarkers for diatoms, cyanobacteria, archaea, green nonsulfur (GNS), sulfate reducing, sulfur oxidizing and methanotrophic bacteria have been identified. Analyses of the ester-bound fatty acids indicate a highly diverse microbial community, dominated by photosynthetic organisms at the surface. The delta C-13 of cyanobacterial biomarkers such as the monomethylalkanes and hopanoids are consistent with the delta C-13 measured for bulk mat (-10%o), while a GNS biomarker, wax esters (WXE), suggests a more depleted delta C-13 for GNS biomass (-16%o). This isotopic relationship is different than that observed in mats at Octopus Spring, Yellowstone National Park (YSNP) where GNS appear to grow photoheterotrophic ally. WXE abundance, while relatively low, is most pronounced in an anaerobic zone just below the cyanobacterial layer. The WXE isotope composition at GN suggests that these bacteria utilize photoautotrophy incorporating dissolved inorganic carbon (DIC) via the 3-hydroxypropionate pathway using H2S or H2.

Anoxic carbon flux in photosynthetic microbial mats as revealed by metatranscriptomics [Anoxic carbon flux in photosynthetic microbial mats as revealed by metatranscriptomics and NanoSIMS.

DOE PAGES

Burow, Luke C.; Woebken, Dagmar; Marshall, Ian PG; ...

2012-11-29

Photosynthetic microbial mats possess extraordinary phylogenetic and functional diversity that makes linking specific pathways with individual microbial populations a daunting task. Close metabolic and spatial relationships between Cyanobacteria and Chloroflexi have previously been observed in diverse microbial mats. Here in this paper, we report that an expressed metabolic pathway for the anoxic catabolism of photosynthate involving Cyanobacteria and Chloroflexi in microbial mats can be reconstructed through metatranscriptomic sequencing of mats collected at Elkhorn Slough, Monterey Bay, CA, USA. In this reconstruction, Microcoleus spp., the most abundant cyanobacterial group in the mats, ferment photosynthate to organic acids, CO 2 and Hmore » 2 through multiple pathways, and an uncultivated lineage of the Chloroflexi take up these organic acids to store carbon as polyhydroxyalkanoates. The metabolic reconstruction is consistent with metabolite measurements and single cell microbial imaging with fluorescence in situ hybridization and NanoSIMS.« less

Anoxic carbon flux in photosynthetic microbial mats as revealed by metatranscriptomics [Anoxic carbon flux in photosynthetic microbial mats as revealed by metatranscriptomics and NanoSIMS.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Burow, Luke C.; Woebken, Dagmar; Marshall, Ian PG

Photosynthetic microbial mats possess extraordinary phylogenetic and functional diversity that makes linking specific pathways with individual microbial populations a daunting task. Close metabolic and spatial relationships between Cyanobacteria and Chloroflexi have previously been observed in diverse microbial mats. Here in this paper, we report that an expressed metabolic pathway for the anoxic catabolism of photosynthate involving Cyanobacteria and Chloroflexi in microbial mats can be reconstructed through metatranscriptomic sequencing of mats collected at Elkhorn Slough, Monterey Bay, CA, USA. In this reconstruction, Microcoleus spp., the most abundant cyanobacterial group in the mats, ferment photosynthate to organic acids, CO 2 and Hmore » 2 through multiple pathways, and an uncultivated lineage of the Chloroflexi take up these organic acids to store carbon as polyhydroxyalkanoates. The metabolic reconstruction is consistent with metabolite measurements and single cell microbial imaging with fluorescence in situ hybridization and NanoSIMS.« less

Teaching about the Constitutional Rights of Students. ERIC Digest.

ERIC Educational Resources Information Center

Gottlieb, Stephen S.

This ERIC digest presents a rationale for teaching students about their rights and responsibilities as citizens under the U.S. Constitution. Social studies teachers have a special role in shaping the lives of young citizens and influencing whether students become politically involved adults. Specific constitutional rights such as the right of a…

Teaching about the Pacific Rim. ERIC Digest No. 43.

ERIC Educational Resources Information Center

Wojtan, Linda S.

This ERIC Digest examines: (1) the meaning of the term "Pacific Rim"; (2) reasons for emphasizing the Pacific Rim in the social studies curriculum; and (3) useful strategies for teaching about this part of the world. The terms, Pacific Rim and Pacific Basin, are used. interchangeably; however, the "Rim" refers to those nations…

Genotype diversity of Escherichia coli isolates in natural waters determined by PFGE and ERIC-PCR.

PubMed

Casarez, Elizabeth A; Pillai, Suresh D; Di Giovanni, George D

2007-08-01

Most library-dependent bacterial source tracking studies using Escherichia coli (E. coli) have focused on strain diversity of isolates obtained from known human and animal faecal sources for library development. In contrast, this study evaluated the genotype variation of E. coli isolated from natural surface water using pulsed field gel electrophoresis (PFGE) and enterobacterial repetitive intergenic consensus sequence polymerase chain reaction (ERIC-PCR) to better understand these naturally occurring populations. A total of 650 water samples were collected over a nine month period from eleven sampling stations from Lake Waco and Belton Lake in Central Texas. Of the 650 water samples collected, 412 were positive for E. coli, yielding a total of 631 E. coli isolates (1-12 isolates collected per sample). PFGE and ERIC-PCR patterns were successfully generated for 555 isolates and were compared using the curve-based Pearson's product-moment correlation coefficient. The 555 E. coli isolates represented 461 PFGE genotypes, with 84% (386/461) of the genotypes being represented by individual isolates. The remaining 75 genotypes were represented by 2-5 isolates each. Using ERIC-PCR, the 555 E. coli isolates represented 175 genotypes, with 63% (109/175) of the genotypes being represented by individual isolates. In contrast to the PFGE results, two ERIC-PCR genotypes represented 37% of the E. coli isolates, (83 and 124 isolates, respectively), and were found throughout the watersheds both spatially and temporally. Based on the PFGE genotype diversity of water isolates, there is little evidence that a small number of environmentally-adapted E. coli represent dominant populations in the studied waterbodies. However, with the lower discriminatory power technique ERIC-PCR, an opposing conclusion might have been drawn. These results emphasize the importance of considering the resolving power of the source tracking technique being used when assessing strain diversity and

Methane Production by Microbial Mats Under Low Sulfate Concentrations

NASA Technical Reports Server (NTRS)

Bebout, Brad M.; Hoehler, Tori M.; Thamdrup, Bo; Albert, Dan; Carpenter, Steven P.; Hogan, Mary; Turk, Kendra; DesMarais, David J.

2003-01-01

Cyanobacterial mats collected in hypersaline salterns were incubated in a greenhouse under low sulfate concentrations ([SO4]) and examined for their primary productivity and emissions of methane and other major carbon species. Atmospheric greenhouse warming by gases such as carbon dioxide and methane must have been greater during the Archean than today in order to account for a record of moderate to warm paleoclemates, despite a less luminous early sun. It has been suggested that decreased levels of oxygen and sulfate in Archean oceans could have significantly stimulated microbial methanogenesis relative to present marine rates, with a resultant increase in the relative importance of methane in maintaining the early greenhouse. We maintained modern microbial mats, models of ancient coastal marine communities, in artificial brine mixtures containing both modern [SO4=] (ca. 70 mM) and "Archean" [SO4] (less than 0.2 mM). At low [SO4], primary production in the mats was essentially unaffected, while rates of sulfate reduction decreased by a factor of three, and methane fluxes increased by up to ten-fold. However, remineralization by methanogenesis still amounted to less than 0.4 % of the total carbon released by the mats. The relatively low efficiency of conversion of photosynthate to methane is suggested to reflect the particular geometry and chemical microenvironment of hypersaline cyanobacterial mats. Therefore, such mats w-ere probably relatively weak net sources of methane throughout their 3.5 Ga history, even during periods of low- environmental levels oxygen and sulfate.

Mating-Type Genes and MAT Switching in Saccharomyces cerevisiae

PubMed Central

Haber, James E.

2012-01-01

Mating type in Saccharomyces cerevisiae is determined by two nonhomologous alleles, MATa and MATα. These sequences encode regulators of the two different haploid mating types and of the diploids formed by their conjugation. Analysis of the MATa1, MATα1, and MATα2 alleles provided one of the earliest models of cell-type specification by transcriptional activators and repressors. Remarkably, homothallic yeast cells can switch their mating type as often as every generation by a highly choreographed, site-specific homologous recombination event that replaces one MAT allele with different DNA sequences encoding the opposite MAT allele. This replacement process involves the participation of two intact but unexpressed copies of mating-type information at the heterochromatic loci, HMLα and HMRa, which are located at opposite ends of the same chromosome-encoding MAT. The study of MAT switching has yielded important insights into the control of cell lineage, the silencing of gene expression, the formation of heterochromatin, and the regulation of accessibility of the donor sequences. Real-time analysis of MAT switching has provided the most detailed description of the molecular events that occur during the homologous recombinational repair of a programmed double-strand chromosome break. PMID:22555442

Arc_Mat: a Matlab-based spatial data analysis toolbox

NASA Astrophysics Data System (ADS)

Liu, Xingjian; Lesage, James

2010-03-01

This article presents an overview of Arc_Mat, a Matlab-based spatial data analysis software package whose source code has been placed in the public domain. An earlier version of the Arc_Mat toolbox was developed to extract map polygon and database information from ESRI shapefiles and provide high quality mapping in the Matlab software environment. We discuss revisions to the toolbox that: utilize enhanced computing and graphing capabilities of more recent versions of Matlab, restructure the toolbox with object-oriented programming features, and provide more comprehensive functions for spatial data analysis. The Arc_Mat toolbox functionality includes basic choropleth mapping; exploratory spatial data analysis that provides exploratory views of spatial data through various graphs, for example, histogram, Moran scatterplot, three-dimensional scatterplot, density distribution plot, and parallel coordinate plots; and more formal spatial data modeling that draws on the extensive Spatial Econometrics Toolbox functions. A brief review of the design aspects of the revised Arc_Mat is described, and we provide some illustrative examples that highlight representative uses of the toolbox. Finally, we discuss programming with and customizing the Arc_Mat toolbox functionalities.

Comparative microbial diversity analyses of modern marine thrombolitic mats by barcoded pyrosequencing.

PubMed

Mobberley, Jennifer M; Ortega, Maya C; Foster, Jamie S

2012-01-01

Thrombolites are unlaminated carbonate structures that form as a result of the metabolic interactions of complex microbial mat communities. Thrombolites have a long geological history; however, little is known regarding the microbes associated with modern structures. In this study, we use a barcoded 16S rRNA gene-pyrosequencing approach coupled with morphological analysis to assess the bacterial, cyanobacterial and archaeal diversity associated with actively forming thrombolites found in Highborne Cay, Bahamas. Analyses revealed four distinct microbial mat communities referred to as black, beige, pink and button mats on the surfaces of the thrombolites. At a coarse phylogenetic resolution, the domain bacterial sequence libraries from the four mats were similar, with Proteobacteria and Cyanobacteria being the most abundant. At the finer resolution of the rRNA gene sequences, significant differences in community structure were observed, with dramatically different cyanobacterial communities. Of the four mat types, the button mats contained the highest diversity of Cyanobacteria, and were dominated by two sequence clusters with high similarity to the genus Dichothrix, an organism associated with the deposition of carbonate. Archaeal diversity was low, but varied in all mat types, and the archaeal community was predominately composed of members of the Thaumarchaeota and Euryarchaeota. The morphological and genetic data support the hypothesis that the four mat types are distinctive thrombolitic mat communities. © 2011 Society for Applied Microbiology and Blackwell Publishing Ltd.

Protocyanobacteria: Oxygenic and Anoxygenic photosynthesis in mat-forming bacteria

NASA Technical Reports Server (NTRS)

Cohen, Y.

1985-01-01

The oldest record of life is preserved in prePhanerozoic stromatolites dated 3500 million years old and is most likely of filamentous mat-forming cyanobacteria. The sedimentary records of cyanobacterial mats in stromatolites are the most abundant record of life throughout the prePhanerozoic. Stromatolites persisted into the Phanerozoic Eon, yet they become much less pronounced relative to earlier ones. The abundance and persistence of cyanobacterial mats throughout most of geological time point to the evolutionary success of these kinds of microbial communities and their possible role in the evolution of the earth and atmosphere.

Biodiversity of the microbial mat of the Garga hot spring.

PubMed

Rozanov, Alexey Sergeevich; Bryanskaya, Alla Victorovna; Ivanisenko, Timofey Vladimirovich; Malup, Tatyana Konstantinovna; Peltek, Sergey Evgenievich

2017-12-28

Microbial mats are a good model system for ecological and evolutionary analysis of microbial communities. There are more than 20 alkaline hot springs on the banks of the Barguzin river inflows. Water temperature reaches 75 °C and pH is usually 8.0-9.0. The formation of microbial mats is observed in all hot springs. Microbial communities of hot springs of the Baikal rift zone are poorly studied. Garga is the biggest hot spring in this area. In this study, we investigated bacterial and archaeal diversity of the Garga hot spring (Baikal rift zone, Russia) using 16S rRNA metagenomic sequencing. We studied two types of microbial communities: (i) small white biofilms on rocks in the points with the highest temperature (75 °C) and (ii) continuous thick phototrophic microbial mats observed at temperatures below 70 °C. Archaea (mainly Crenarchaeota; 19.8% of the total sequences) were detected only in the small biofilms. The high abundance of Archaea in the sample from hot springs of the Baikal rift zone supplemented our knowledge of the distribution of Archaea. Most archaeal sequences had low similarity to known Archaea. In the microbial mats, primary products were formed by cyanobacteria of the genus Leptolyngbya. Heterotrophic microorganisms were mostly represented by Actinobacteria and Proteobacteria in all studied samples of the microbial mats. Planctomycetes, Chloroflexi, and Chlorobi were abundant in the middle layer of the microbial mats, while heterotrophic microorganisms represented mostly by Firmicutes (Clostridia, strict anaerobes) dominated in the bottom part. Besides prokaryotes, we detect some species of Algae with help of detection their chloroplasts 16 s rRNA. High abundance of Archaea in samples from hot springs of the Baikal rift zone supplemented our knowledge of the distribution of Archaea. Most archaeal sequences had low similarity to known Archaea. Metagenomic analysis of microbial communities of the microbial mat of Garga hot spring showed that

Rural Philosophy for Education: Wendell Berry's Tradition. ERIC Digest.

ERIC Educational Resources Information Center

Theobald, Paul

This ERIC Digest reviews past and present rural educational philosophy, focusing on the views of Wendell Berry, a Kentucky farmer and novelist who in recent years has emerged as a leading American philosopher. The major difference underlying rural and urban living is the relationship of people with nature. Rural living is much more closely related…

Ideas for Integrating Japan into the Curriculum. ERIC Digest.

ERIC Educational Resources Information Center

Wojtan, Linda S.

This ERIC Digest discusses how, by studying Japan, the larger context of the Asia-Pacific region can be explored and students can be introduced to current realities. The top 5 competitive countries for 1994 were the United States, Singapore, Japan, Hong Kong, and Germany. Because of the increasing interdependence between the United States and…

Macro Analysis Tool - MAT

EPA Science Inventory

This product is an easy-to-use Excel-based macro analysis tool (MAT) for performing comparisons of air sensor data with reference data and interpreting the results. This tool tackles one of the biggest hurdles in citizen-led community air monitoring projects – working with ...

Protein and Bacterial Antifouling Behavior of Melt-Coextruded Nanofiber Mats.

PubMed

Kim, Si-Eun; Zhang, Cong; Advincula, Abigail A; Baer, Eric; Pokorski, Jonathan K

2016-04-13

Antifouling surfaces are important for biomedical devices to prevent secondary infections and mitigate the effects of the foreign body response. Herein, we describe melt-coextruded poly(ε-caprolactone) (PCL) nanofiber mats grafted with antifouling polymers. Nonwoven PCL fiber mats are produced using a multilayered melt coextrusion process followed by high-pressure hydroentanglement to yield porous patches. The resulting fiber mats show submicrometer cross-sectional fiber dimensions and yield pore sizes that were nearly uniform, with a mean pore size of 1.6 ± 0.9 μm. Several antifouling polymers, including hydrophilic, zwitterionic, and amphipathic molecules, are grafted to the surface of the mats using a two-step procedure that includes photochemistry followed by the copper-catalyzed azide-alkyne cycloaddition reaction. Fiber mats are evaluated using separate adsorption tests for serum proteins and E. coli. The results indicate that poly(oligo(ethylene glycol) methyl ether methacrylate)-co-(trifluoroethyl methacrylate) (poly(OEGMEMA-co-TFEMA)) grafted mats exhibit approximately 85% less protein adhesion and 97% less E. coli adsorption when compared to unmodified PCL fibermats. In dynamic antifouling testing, the amphiphilic fluorous polymer surface shows the highest flux and highest rejection value of foulants. The work presented within has implications on the high-throughput production of antifouling microporous patches for medical applications.

Polyelectrolyte-Functionalized Nanofiber Mats Control the Collection and Inactivation of Escherichia coli

PubMed Central

Rieger, Katrina A.; Porter, Michael; Schiffman, Jessica D.

2016-01-01

Quantifying the effect that nanofiber mat chemistry and hydrophilicity have on microorganism collection and inactivation is critical in biomedical applications. In this study, the collection and inactivation of Escherichia coli K12 was examined using cellulose nanofiber mats that were surface-functionalized using three polyelectrolytes: poly (acrylic acid) (PAA), chitosan (CS), and polydiallyldimethylammonium chloride (pDADMAC). The polyelectrolyte functionalized nanofiber mats retained the cylindrical morphology and average fiber diameter (~0.84 µm) of the underlying cellulose nanofibers. X-ray photoelectron spectroscopy (XPS) and contact angle measurements confirmed the presence of polycations or polyanions on the surface of the nanofiber mats. Both the control cellulose and pDADMAC-functionalized nanofiber mats exhibited a high collection of E. coli K12, which suggests that mat hydrophilicity may play a larger role than surface charge on cell collection. While the minimum concentration of polycations needed to inhibit E. coli K12 was 800 µg/mL for both CS and pDADMAC, once immobilized, pDADMAC-functionalized nanofiber mats exhibited a higher inactivation of E. coli K12, (~97%). Here, we demonstrate that the collection and inactivation of microorganisms by electrospun cellulose nanofiber mats can be tailored through a facile polyelectrolyte functionalization process. PMID:28773422

Phylogenetic stratigraphy in the Guerrero Negro hypersaline microbial mat.

PubMed

Harris, J Kirk; Caporaso, J Gregory; Walker, Jeffrey J; Spear, John R; Gold, Nicholas J; Robertson, Charles E; Hugenholtz, Philip; Goodrich, Julia; McDonald, Daniel; Knights, Dan; Marshall, Paul; Tufo, Henry; Knight, Rob; Pace, Norman R

2013-01-01

The microbial mats of Guerrero Negro (GN), Baja California Sur, Mexico historically were considered a simple environment, dominated by cyanobacteria and sulfate-reducing bacteria. Culture-independent rRNA community profiling instead revealed these microbial mats as among the most phylogenetically diverse environments known. A preliminary molecular survey of the GN mat based on only ∼1500 small subunit rRNA gene sequences discovered several new phylum-level groups in the bacterial phylogenetic domain and many previously undetected lower-level taxa. We determined an additional ∼119,000 nearly full-length sequences and 28,000 >200 nucleotide 454 reads from a 10-layer depth profile of the GN mat. With this unprecedented coverage of long sequences from one environment, we confirm the mat is phylogenetically stratified, presumably corresponding to light and geochemical gradients throughout the depth of the mat. Previous shotgun metagenomic data from the same depth profile show the same stratified pattern and suggest that metagenome properties may be predictable from rRNA gene sequences. We verify previously identified novel lineages and identify new phylogenetic diversity at lower taxonomic levels, for example, thousands of operational taxonomic units at the family-genus levels differ considerably from known sequences. The new sequences populate parts of the bacterial phylogenetic tree that previously were poorly described, but indicate that any comprehensive survey of GN diversity has only begun. Finally, we show that taxonomic conclusions are generally congruent between Sanger and 454 sequencing technologies, with the taxonomic resolution achieved dependent on the abundance of reference sequences in the relevant region of the rRNA tree of life.

A Global Perspective on Human Rights Education. ERIC Digest.

ERIC Educational Resources Information Center

Patrick, John J.

This ERIC Digest outlines what is meant by the phrase human rights and the origin of the concept. It also traces the delineation of the concept of human rights from the 17th century antecedent of "natural rights" to its eventual incarnation as inherent political or personal rights, such as freedom of speech, press, assembly, and…

Science/Technology/Society in the Social Studies. ERIC Digest.

ERIC Educational Resources Information Center

Heath, Phillip A.

The current trend to include the relationships of science and technology to human societies in the social studies curriculum is the focus of this ERIC Digest. The Digest discusses: (1) major themes in education on science/technology/society (STS); (2) the rationale for emphasizing STS in the social studies; and (3) how to include STS in the…

ERIC on Compact Disc (CD-ROM). A Case Study.

ERIC Educational Resources Information Center

Brandhorst, Ted

ORI, Inc., and SilverPlatter, Inc., have joined together in a joint venture to offer the ERIC database to the public on compact laser disc (CD-ROM). Data from both "Resources in Education" (RIE) and "Current Index to Journals in Education" (CIJE) will be offered on a single disc from January 1983 to the present (with the disc…

Pressure Mapping Mat for Tele-Home Care Applications

PubMed Central

Saenz-Cogollo, Jose Francisco; Pau, Massimiliano; Fraboni, Beatrice; Bonfiglio, Annalisa

2016-01-01

In this paper we present the development of a mat-like pressure mapping system based on a single layer textile sensor and intended to be used in home environments for monitoring the physical condition of persons with limited mobility. The sensor is fabricated by embroidering silver-coated yarns on a light cotton fabric and creating pressure-sensitive resistive elements by stamping the conductive polymer poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) at the crossing points of conductive stitches. A battery-operated mat prototype was developed and includes the scanning circuitry and a wireless communication module. A functional description of the system is presented together with a preliminary experimental evaluation of the mat prototype in the extraction of plantar pressure parameters. PMID:26978369

Earth Observations taken by the Expedition 18 Crew

NASA Image and Video Library

2009-01-30

ISS018-E-025705 (30 Jan. 2009) --- Betsiboka River floods in Madagascar are featured in this image photographed by an Expedition 18 crewmember on the International Space Station. Between Jan. 18-20, 2009, Tropical Storm Eric swept along the east coast of the island nation of Madagascar. Rain from this storm fell in the catchment of the Betsiboka River, one of the main rivers in northern Madagascar. In an unlikely coincidence, a larger storm, Cyclone Fanele crossed central Madagascar the next day on Jan. 21, with its outer bands dropping more rain in the Betsiboka basin. By the time this image was taken on the Jan. 30, the river was flooding all along its length.

Using Film To Teach History: An ERIC/ChESS Sample.

ERIC Educational Resources Information Center

Pinhey, Laura

2002-01-01

Provides citations with abstracts from the ERIC database focusing on using film to teach history. Includes background information and teaching materials on topics such as using documentary films, the use of film and television to teach history, and teaching history using the film,"JFK," by Oliver Stone. (CMK)

Q & A with Ed Tech Leaders: Interview with Eric Chiang

ERIC Educational Resources Information Center

Viner, Mark; Shaughnessy, Michael F.

2016-01-01

The authors present this interview with Eric Chiang, Associate Professor of Economics, Director of Instructional Technology, and Technology Director for the Online MBA Program at Florida Atlantic University. He has authored 26 peer-reviewed research publications and is the author of "CoreEconomics," an economic principles textbook now in…

Recent International Documents and Journal Articles from the ERIC Database.

ERIC Educational Resources Information Center

International Journal of Early Years Education, 1998

1998-01-01

Annotates recent international documents and journal articles from the ERIC database. Document topics include racial equality, and balancing early childhood education and work. Journal article topics include foster care in Iraqi Kurdistan; child care in Sweden; teacher-child interaction in Australian centers; teacher education in Brazil, Iceland,…

Supervision: Exploring the Effective Components. ERIC/CASS Counseling Digest Series.

ERIC Educational Resources Information Center

Borders, L. DiAnne, Ed.

This document contains a collection of ERIC Digests on supervision, a topic of critical professional importance for counselors. Following an introductory article by the guest editor, L. DiAnne Borders, "Supervision: Exploring the Effective Components," 19 digests address a different facet of supervision. The 19 digests are: (1)…

Flakeboard thickness swelling. Part I, Stress relaxation in a flakeboard mat

Treesearch

R. L. Geimer; J. H. Kwon; J. Bolton

1998-01-01

The steam injection schedule best suited for dimensionally stabilizing a flake mat is one in which steam treatment is initiated before the press is closed and is continued at least until the mat attains target thickness. Experiments showed that resinless mats treated with 20 sec of steam at 600 kPa had maximum thickness swelling of 205% compared to 350% for resinless...

Orbiting Carbon Observatory Briefing

NASA Image and Video Library

2009-01-29

Eric Ianson speaks during a media briefing to discuss the upcoming Orbiting Carbon Observatory mission, the first NASA spacecraft dedicated to studying carbon dioxide, Thursday, Jan. 29, 2009, at NASA Headquarters in Washington. Photo Credit: (NASA/Paul E. Alers)

Project To Design a Marketing Plan for Promoting Educators' Awareness of and Access to ERIC Products. Proposed Marketing Plan.

ERIC Educational Resources Information Center

Contemporary Associates, Inc., Washington, DC.

The proposed strategy, which is designed to maximize the effectiveness and minimize the costs of marketing the Information Analysis Products (IAPs) produced by the 16 ERIC Clearinghouses, is based on a study of the concept of centralized versus decentralized ordering of selected ERIC products. The experiment measured four variables--postage,…

The biogeochemistry of microbial mats, stromatolites and the ancient biosphere

NASA Technical Reports Server (NTRS)

Desmarais, D. J.; Canfield, D. E.

1991-01-01

Stromatolites offer an unparalleled geologic record of early life, because they constitute the oldest and most abundant recognizable remains of microbial ecosystems. Microbial mats are living homologs of stromatolites; thus, the physiology of the microbiota as well as the processes which create those features of mats (e.g., biomarker organic compounds, elemental and stable isotopic compositions) which are preserved in the ancient record. Observations of the carbon isotopic composition (delta C-13) of stromatolites and microbial mats were made and are consistent with the hypothesis that atmospheric CO2 concentrations have declined by at least one to two orders of magnitude during the past 2.5 Ga. Whereas delta C-13 values of carbonate carbon average about 0 permil during both the early and mid-Proterozoic, the delta C-13 values of stromatolitic organic matter increase from an average of -35 between 2.0 and 2.6 Ga ago to an average of about -28 about 1.0 Ga ago. Modern microbial mats in hypersaline environments have delta C-13 values typically in the range of -5 to -9, relative to an inorganic bicarbonate source at 0 permil. Both microbial mats and pur cultures of cyanobacteria grown in waters in near equilibrium with current atmospheric CO2 levels exhibit minimal discrimination against C-13. In contrast, hot spring cyanobacterial mats or cyanobacterial cultures grown under higher CO2 levels exhibit substantially greater discrimination. If care is taken to compare modern mats with stromatolites from comparable environments, it might be possible to estimate ancient levels of atmospheric CO2. In modern microbial mats, a tight coupling exists between photosynthetic organic carbon production and subsequent carbon oxidation, mostly by sulfate reduction. The rate of one process fuels a high rate of the other, with much of the sulfate reduction occurring within the same depth interval as oxygenic photosynthesis. Other aspects of this study are presented.

30 CFR 77.513 - Insulating mats at power switches.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Insulating mats at power switches. 77.513... COAL MINES Electrical Equipment-General § 77.513 Insulating mats at power switches. Dry wooden... switchboards and power-control switches where shock hazards exist. However, metal plates on which a person...

30 CFR 77.513 - Insulating mats at power switches.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Insulating mats at power switches. 77.513... COAL MINES Electrical Equipment-General § 77.513 Insulating mats at power switches. Dry wooden... switchboards and power-control switches where shock hazards exist. However, metal plates on which a person...

30 CFR 77.513 - Insulating mats at power switches.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Insulating mats at power switches. 77.513... COAL MINES Electrical Equipment-General § 77.513 Insulating mats at power switches. Dry wooden... switchboards and power-control switches where shock hazards exist. However, metal plates on which a person...

30 CFR 77.513 - Insulating mats at power switches.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 30 Mineral Resources 1 2013-07-01 2013-07-01 false Insulating mats at power switches. 77.513... COAL MINES Electrical Equipment-General § 77.513 Insulating mats at power switches. Dry wooden... switchboards and power-control switches where shock hazards exist. However, metal plates on which a person...

30 CFR 77.513 - Insulating mats at power switches.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Insulating mats at power switches. 77.513... COAL MINES Electrical Equipment-General § 77.513 Insulating mats at power switches. Dry wooden... switchboards and power-control switches where shock hazards exist. However, metal plates on which a person...

Reactive composite compositions and mat barriers

DOEpatents

Langton, Christine A.; Narasimhan, Rajendran; Karraker, David G.

2001-01-01

A hazardous material storage area has a reactive multi-layer composite mat which lines an opening into which a reactive backfill and hazardous material are placed. A water-inhibiting cap may cover the hazardous material storage area. The reactive multi-layer composite mat has a backing onto which is placed an active layer which will neutralize or stabilize hazardous waste and a fronting layer so that the active layer is between the fronting and backing layers. The reactive backfill has a reactive agent which can stabilize or neutralize hazardous material and inhibit the movement of the hazardous material through the hazardous material storage area.

Eric Boe and Bob Behnken Dragon Tour

NASA Image and Video Library

2017-03-08

Astronaut Bob Behnken emerges from the hatch of a SpaceX Crew Dragon spacecraft in manufacturing at SpaceX's headquarters and factory in Hawthorne, California. Behnken is one of four NASA astronauts selected to train with Boeing and SpaceX ahead of flight tests for NASA's Commercial Crew Program. Along with Behnken, Eric Boe, Doug Hurley and Suni Williams are working with the companies on their independent spacecraft and launch vehicles being developed to take astronauts to the International Space Station. Photo credit: SpaceX

Teaching about the Life and Health of Cells. ERIC Digest.

ERIC Educational Resources Information Center

Haury, David L.

Modern technology in life and health sciences brings a new understanding to the study of cells and as a result, the National Science Education Standards emphasize understanding of science and technology. This ERIC Digest describes the central role of cell biology (cytology) in understanding these areas and explains conceptual difficulties and…

The Case Method in Teacher Education: Alaskan Models. ERIC Digest.

ERIC Educational Resources Information Center

Kleinfeld, Judith

This ERIC digest discusses the theoretical basis of case teaching and examines its strengths and limitations as a tool for teacher education. Case teaching presents authentic, concrete teaching problems for students to analyze. The study of a classroom fight, for example, might draw discussion of racial, ethical, political, and other community…

Electrospun polyvinylpyrrolidone (PVP)/green tea extract composite nanofiber mats and their antioxidant activities

NASA Astrophysics Data System (ADS)

Pusporini, Pusporini; Edikresnha, Dhewa; Sriyanti, Ida; Suciati, Tri; Miftahul Munir, Muhammad; Khairurrijal, Khairurrijal

2018-05-01

Electrospinning was employed to make PVP (polyvinylpyrrolidone)/GTE (green tea extract) composite nanofiber mats. The electrospun PVP nanofiber mat as well as the PVP/GTE nanofiber mats were uniform. The average fiber diameter of PVP/GTE composite nanofiber mat decreased with increasing the GTE weight fraction (or decreasing the PVP weight fraction) in the PVP/GTE solution because the PVP/GTE solution concentration decreased. Then, the broad FTIR peak representing the stretching vibrations of O–H in hydroxyl groups of phenols and the stretching of N–H in amine groups of the GTE paste shifted to higher wavenumbers in the PVP/GTE composite nanofiber mats. These peak shifts implied that PVP and catechins of GTE in the PVP/GTE composite nanofiber mats had intermolecular interactions via hydrogen bonds between carbonyl groups of PVP and hydroxyl groups of catechins in GTE. Lastly, the antioxidant activity of the PVP/GTE composite nanofiber mat increased with reducing the average fiber diameter because the amount of catechins in the composite nanofiber mat increased with the increase of surface area due to the reduction of the average fiber diameter.

Spatiotemporal patterns in community structure of macroinvertebrates inhabiting calcareous periphyton mats

USGS Publications Warehouse

Liston, S.E.; Trexler, J.C.

2005-01-01

Calcareous floating periphyton mats in the southern Everglades provide habitat for a diverse macroinvertebrate community that has not been well characterized. Our study described this community in an oligotrophic marsh, compared it with the macroinvertebrate community associated with adjacent epiphytic algae attached to macrophytes in the water column, and detected spatial patterns in density and community structure. The floating periphyton mat (floating mat) and epiphytic algae in the water column (submerged epiphyton) were sampled at 4 sites (???1 km apart) in northern Shark River Slough, Everglades National Park (ENP), in the early (July) and late (November) wet season. Two perpendicular 90-m transects were established at each site and ???100 samples were taken in a nested design. Sites were located in wet-prairie spikerush-dominated sloughs with similar water depths and emergent macrophyte communities. Floating mats were sampled by taking cores (6-cm diameter) that were sorted under magnification to enumerate infauna retained on a 250-??m-mesh sieve and with a maximum dimension >1 mm. Our results showed that floating mats provide habitat for a macroinvertebrate community with higher densities (no. animals/g ash-free dry mass) of Hyalella azteca, Dasyhelea spp., and Cladocera, and lower densities of Chironomidae and Planorbella spp. than communities associated with submerged epiphyton. Densities of the most common taxa increased 3x to 15x from early to late wet season, and community differences between the 2 habitat types became more pronounced. Floating-mat coverage and estimated floating-mat biomass increased 20 to 30%, and 30 to 110%, respectively, at most sites in the late wet season. Some intersite variation was observed in individual taxa, but no consistent spatial pattern in any taxon was detected at any scale (from 0.2 m to 3 km). Floating mats and their resident macroinvertebrate communities are important components in the Everglades food web. This

STS-133 crew members Lindsey, Boe and Drew during Tool/Repair Kits training with instructor

NASA Image and Video Library

2010-01-26

JSC2010-E-014264 (26 Jan. 2010) --- NASA astronaut Eric Boe, STS-133 pilot, participates in an ISS tools and repair kits training session in the Space Vehicle Mock-up Facility at NASA's Johnson Space Center. Instructor Ivy Apostolakopoulos assisted Boe.

STS-133 crew members Lindsey, Boe and Drew during Tool/Repair Kits training with instructor

NASA Image and Video Library

2010-01-26

JSC2010-E-014266 (26 Jan. 2010) --- NASA astronauts Steve Lindsey (right), STS-133 commander; and Eric Boe, pilot, participate in an ISS tools and repair kits training session in the Space Vehicle Mock-up Facility at NASA's Johnson Space Center.

Fabrication and In Vitro/In Vivo Performance of Mucoadhesive Electrospun Nanofiber Mats Containing α-Mangostin.

PubMed

Samprasit, Wipada; Rojanarata, Theerasak; Akkaramongkolporn, Prasert; Ngawhirunpat, Tanasait; Kaomongkolgit, Ruchadaporn; Opanasopit, Praneet

2015-10-01

This study aimed to fabricate mucoadhesive electrospun nanofiber mats containing α-mangostin for the maintenance of oral hygiene and reduction of the bacterial growth that causes dental caries. Synthesized thiolated chitosan (CS-SH) blended with polyvinyl alcohol (PVA) was selected as the mucoadhesive polymer. α-Mangostin was incorporated into the CS-SH/PVA solution and electrospun to obtain nanofiber mats. Scanning electron microscopy, differential scanning calorimetry, X-ray diffraction, and tensile strength testing were used to characterize the mats. The swelling degree and mucoadhesion were also determined. The nanofiber mats were further evaluated regarding their α-mangostin content, in vitro α-mangostin release, antibacterial activity, cytotoxicity, in vivo performance, and stability. The results indicated that the mats were in the nanometer range. The α-mangostin was well incorporated into the mats, with an amorphous form. The mats showed suitable tensile strength, swelling, and mucoadhesive properties. The loading capacity increased when the initial amount of α-mangostin was increased. Rapid release of α-mangostin from the mats was achieved. Additionally, a fast bacterial killing rate occurred at the lowest concentration of nanofiber mats when α-mangostin was added to the mats. The mats were less cytotoxic after use for 72 h. Moreover, in vivo testing indicated that the mats could reduce the number of oral bacteria, with a good mouth feel. The mats maintained the amount of α-mangostin for 6 months. The results suggest that α-mangostin-loaded mucoadhesive electrospun nanofiber mats may be a promising material for oral care and the prevention of dental caries.

4. Historic American Buildings Survey Roger Sturtevant, Photographer Jan. 28, ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

4. Historic American Buildings Survey Roger Sturtevant, Photographer Jan. 28, 1934 CHURCH FROM NORTH-WEST - Mission San Antonio de Padua, Hunter Liggett Military Reservation, Jolon, Monterey County, CA

1. Historic American Buildings Survey Roger Sturtevant, Photographer Jan. 28, ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

1. Historic American Buildings Survey Roger Sturtevant, Photographer Jan. 28, 1934 VIEW FROM SOUTH (FRONT) - Mission San Antonio de Padua, Hunter Liggett Military Reservation, Jolon, Monterey County, CA

Antibacterial electrospun chitosan-polyethylene oxide nanocomposite mats containing ZIF-8 nanoparticles.

PubMed

Kohsari, Iraj; Shariatinia, Zahra; Pourmortazavi, Seied Mahdi

2016-10-01

Antimicrobial chitosan-polyethylene oxide (CS-PEO) nanofiber mats loaded with 3, 5 and 10% (w/w) of zeolitic imidazolate framework-8 nanoparticles (ZIF-8 NPs, ∼60nm diameter) were developed by electrospinning technique. The CS-PEO-GA-3% ZIF-8 NPs crosslinked with glutaraldehyde (GA) vapor was also prepared. The electrospun mats were characterized by various analysis including FE-SEM, EDAX, elemental mapping, FT-IR, contact angle, TGA/DSC as well as tensile strength analysis. The nanofibers had average diameters within the range ∼70-120nm. Antimicrobial activities of the CS-PEO and CS-PEO-3% ZIF-8 mats were evaluated by the viable cell-counting method for determining their effectiveness in reducing or halting the growth of Staphylococcus aureus and Escherichia coli bacteria so that the CS-PEO mat containing 3% ZIF-8 revealed 100% bactericidal activity against both kinds of bacteria. The crosslinked CS-PEO-GA-3% ZIF-8 NPs sample was less thermally stable but more hydrophilic than its related non-crosslinked mat reflecting there was no need to crosslink the fibers using a chemical crosslinker having adverse effects. The highest hydrophobicity and appropriate thermal and tensile properties of CS-PEO-3% ZIF-8 NPs among those of the mats including 5 and 10% ZIF-8 NPs suggested that the mentioned mat is the most suitable sample for food coating applications. Copyright © 2016 Elsevier B.V. All rights reserved.

Users guide for ERB 7 MAT (including the first year quality control)

NASA Technical Reports Server (NTRS)

Groveman, B.

1984-01-01

In the first section of this report background information for the use of the ERB-7 Master Archival Tapes (MAT) is provided. The second section gives details regarding the scientific validity and quality of the MAT. The MAT data analyzed covers the period from November 16, 1978 to October 31, 1979.

Compositions and method of use of constructed microbial mats

DOEpatents

Bender, Judith A.; Phillips, Peter C.

1997-01-01

Compositions and methods of use of constructed microbial mats, comprising cyanobacteria and purple autotrophic bacteria and an organic nutrient source, in a laminated structure, are described. The constructed microbial mat is used for bioremediation of different individual contaminants and for mixed or multiple contaminants, and for production of beneficial compositions and molecules.

2. Historic American Buildings Survey Roger Sturtevant, Photographer Jan. 28, ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

2. Historic American Buildings Survey Roger Sturtevant, Photographer Jan. 28, 1934 SOUTH ELEVATION OF CHURCH (FRONT) - Mission San Antonio de Padua, Hunter Liggett Military Reservation, Jolon, Monterey County, CA

Capital Outlay: A Critical Concern in Rural Education. ERIC Digest.

ERIC Educational Resources Information Center

Hunter, James; Howley, Craig B.

This digest, which is based primarily on the 1989 ERIC/CRESS monograph entitled "Achievement of Equity in Capital Outlay Financing: A Policy Analysis for the States," by D. Thompson G. Stewart, D. Honeyman, and R. Wood, addresses possible solutions to the emerging problem of capital outlay financing, with special attention to facilities…

The MAT-sf: identifying risk for major mobility disability.

PubMed

Rejeski, W Jack; Rushing, Julia; Guralnik, Jack M; Ip, Edward H; King, Abby C; Manini, Todd M; Marsh, Anthony P; McDermott, Mary M; Fielding, Roger A; Newman, Anne B; Tudor-Locke, Catrine; Gill, Thomas M

2015-05-01

The assessment of mobility is essential to both aging research and clinical geriatric practice. A newly developed self-report measure of mobility, the mobility assessment tool-short form (MAT-sf), uses video animations as an innovative method to improve measurement accuracy/precision. The primary aim of the current study was to evaluate whether MAT-sf scores can be used to identify risk for major mobility disability (MMD). This article is based on data collected from the Lifestyle Interventions and Independence for Elders study and involved 1,574 older adults between the ages of 70-89. The MAT-sf was administered at baseline; MMD, operationalized as failure to complete the 400-m walk ≤ 15 minutes, was evaluated at 6-month intervals across a period of 42 months. The outcome of interest was the first occurrence of MMD or incident MMD. After controlling for age, sex, clinic site, and treatment arm, baseline MAT-sf scores were found to be effective in identifying risk for MMD (p < .0001). Partitioning the MAT-sf into four groups revealed that persons with scores <40, 40-49, 50-59, and 60+ had failure rates across 42 months of follow-up of 66%, 52%, 35%, and 22%, respectively. The MAT-sf is a quick and efficient way of identifying older adults at risk for MMD. It could be used to clinically identify older adults that are in need of intervention for MMD and provides a simple means for monitoring the status of patients' mobility, an important dimension of functional health. © The Author 2015. Published by Oxford University Press on behalf of The Gerontological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

3. Historic American Buildings Survey Roger Sturtevant, Photographer Jan. 28, ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

3. Historic American Buildings Survey Roger Sturtevant, Photographer Jan. 28, 1934 FRONT OF CHURCH FROM SOUTH-EAST - Mission San Antonio de Padua, Hunter Liggett Military Reservation, Jolon, Monterey County, CA

The compression of wood/thermoplastic fiber mats during consolidation

Treesearch

Karl R. Englund; Michael P. Wolcott; John C. Hermanson

2004-01-01

Secondary processing of non-woven wood and wood/thermoplastic fiber mats is generally performed using compression molding, where heated platens or dies form the final product. Although the study and use of wood-fiber composites is widespread, few research efforts have explicitly described the fundamentals of mat consolidation. In contrast, the wood composite literature...

Validity Study of a Jump Mat Compared to the Reference Standard Force Plate.

PubMed

Rogan, Slavko; Radlinger, Lorenz; Imhasly, Caroline; Kneubuehler, Andrea; Hilfiker, Roger

2015-12-01

In the field of vertical jump diagnostics, force plates (FP) are the reference standard. Recently, despite a lack of evidence, jump mats have been used increasingly. Important factors in favor of jumping mats are their low cost and portability. This validity study compared the Haynl-Elektronik jump mat (HE jump mat) with the reference standard force plate. Ten healthy volunteers participated and each participant completed three series of five drop jumps (DJ). The parameters ground contact time (GCT) and vertical jump height (VJH) from the HE jump mat and the FP were used to evaluate the concurrent validity. The following statistical calculations were performed: Pearson's correlation (r), Bland-Altman plots (standard and for adjusted trend), and regression equations. The Bland-Altman plots suggest that the HE jump mat measures shorter contact times and higher jump heights than the FP. The trend-adjusted Bland-Altman plot shows higher mean differences and wider wing-spreads of confidence limits during longer GCT. During the VJH the mean differences and the wing-spreads of the confidence limits throughout the range present as relatively constant. The following regression equations were created, as close as possible to the true value: GCT = 5.920385 + 1.072293 × [value HE jump mat] and VJH = -1.73777 + 1.011156 × [value HE jump mat]. The HE jump mat can be recommended in relation to the validity of constraints. In this study, only a part of the quality criteria were examined. For the final recommendation it is advised to examine the HE jump mat on the other quality criteria (test-retest reliability, sensitivity change).

Microbial and Functional Gene Diversity in the Thrombolitic Mats of Highborne Cay, Bahamas

NASA Astrophysics Data System (ADS)

Foster, J. S.; Mobberley, J. M.

2010-04-01

In this study we examine the metagenome of modern thrombolitic mats. Our results indicate that thrombolitic mats are far more diverse than previously assumed; and gene analysis is now elucidating the molecular pathways needed for thrombolitic mat development.

Accuracy of a vertical jump contact mat for determining jump height and flight time.

PubMed

Whitmer, Tyler D; Fry, Andrew C; Forsythe, Charles M; Andre, Matthew J; Lane, Michael T; Hudy, Andrea; Honnold, Darric E

2015-04-01

Several devices are available to measure vertical jump (VJ) height based on flight time, VJ reach height, or ground reaction forces. The purpose of this study was to determine the accuracy of a VJ mat for measuring flight time and VJ height compared with a VJ tester or a force plate. Seventeen men and 18 women (X ± SD; age = 20.9 ± 0.7 years, height = 176.1 ± 0.9 cm, weight = 72.6 ± 13.5 kg) served as subjects. Subjects performed counter-movement vertical jumps while standing on both a force plate (1,000 Hz) and a VJ mat. A Vertec VJ tester was used to measure jump reach. Compared with the force plate, the VJ mat reported greater VJ height (VJ mat = 0.50 ± 0.12 m, force plate = 0.34 ± 0.10 m) and flight time (VJ mat = 0.629 ± 0.078 seconds, force plate = 0.524 ± 0.077 seconds). Comparison of VJ heights from the VJ mat and the Vertec revealed no significant differences (Vertec = 0.48 ± 0.11 m). Regression analyses indicated strong relationships between testing methods and suggested that high VJ performances may be underestimated with the VJ mat. This particular VJ mat compared favorably with the Vertec but not the force plate. It seems that the different flight times derived from the VJ mat may permit the VJ mat to be in closer agreement with VJ heights from the Vertec. Also, the VJ mat may not be an appropriate tool for assessing high VJ performances (i.e., ≥0.70 m; ≈28 inches). Practitioners and researchers using similar VJ mats may not obtain accurate flight times and may underestimate high performers.

Argonne Director Eric Isaacs talks about ARRA funding at Argonne

DOE Office of Scientific and Technical Information (OSTI.GOV)

Isaacs, Eric

2009-01-01

Argonne is set to receive over $150 million in stimulus funds. Director Eric Isaacs describes how these funds will be put to good use—hiring employees and contractors, cleaning up the nuclear footprint, and investing in technologies for America's future. More info on Argonne and ARRA here: http://www.anl.gov/recovery/index.html

Systems Theory and the Earth Systems Approach in Science Education. ERIC Digest.

ERIC Educational Resources Information Center

Lee, Hyongyong

The systems approach provides a framework for integrating different scientific disciplines. This approach is used often in Earth Systems Education. This ERIC Digest describes the systems theory and its influence on science education. (Contains 16 references.) (YDS)

The Effects of Low Sulfate Concentrations on Modern Microbial Mat Communities: A Long Term Manipulation

NASA Technical Reports Server (NTRS)

Bebout, Brad; Carpenter, Steve; DesMarais, David J.; Discipulo, Mykell; Hogan, Mary; Turk, Kendra

2002-01-01

Microbial mats were widespread during the first ca. 2 Ga. of our biosphere's history. To better understand microbial ecosystems and their biomarkers under the low sulfate levels present in early oceans, we attempted a long-term (ca. 1 year) manipulation of sulfate in modem mats. Mats collected from salt ponds at Guerrero Negro, Baja Calif. Sur were incubated in a Greenhouse "Collaboratory" at Ames. Mats were maintained in artificial seawater brine containing either: 1) sulfate levels normal for these mats (70 mM), or 2) brine in which sulfate was replaced by chloride. Sulfate concentrations in the "low sulfate" brine gradually approached their lowest (to date) value of 0. 1 mM as sulfate was consumed and/or diffused out of the mat over a period of ca. 4 months. During that period of time, a number of differences between the treatments emerged. Relative to the "low sulfate" mats, "normal sulfate" mats had: 1) lower consumption of oxygen in the lower levels of the mat, 2) higher efficiencies of oxygenic photosynthesis, and 3) higher rates of nitrogen fixation. Rates of methane production by the mats increased greatly as sulfate concentrations fell below ca. 0.2 mM. In contrast, "low" and "normal" sulfate mats had similar net rates of exchange of O2 and dissolved inorganic C between the mats and overlying water. Reduced sulfate levels have diverse impacts upon these ecosystems.

Quantifying Thin Mat Floating Marsh Strength and Interaction with Hydrodynamic Conditions

NASA Astrophysics Data System (ADS)

Collins, J. H., III; Sasser, C.; Willson, C. S.

2016-12-01

Louisiana possesses over 350,000 acres of unique floating vegetated systems known as floating marshes or flotants. Floating marshes make up 70% of the Terrebonne and Barataria basin wetlands and exist in several forms, mainly thick mat or thin mat. Salt-water intrusion, nutria grazing, and high-energy wave events are believed to be some contributing factors to the degradation of floating marshes; however, there has been little investigation into the hydrodynamic effects on their structural integrity. Due to their unique nature, floating marshes could be susceptible to changes in the hydrodynamic environment that may result from proposed river freshwater and sediment diversion projects introducing flow to areas that are typically somewhat isolated. This study aims to improve the understanding of how thin mat floating marshes respond to increased hydrodynamic stresses and, more specifically, how higher water velocities might increase the washout probability of this vegetation type. There are two major components of this research: 1) A thorough measurement of the material properties of the vegetative mats as a root-soil matrix composite material; and 2) An accurate numerical simulation of the hydrodynamics and forces imposed on the floating marsh mats by the flow. To achieve these goals, laboratory and field experiments were conducted using a customized device to measure the bulk properties of typical floating marshes. Additionally, Delft-3D FLOW and ANSYS FLUENT were used to simulate the flow around a series of simplified mat structures in order to estimate the hydrodynamic forcings on the mats. The hydrodynamic forcings are coupled with a material analysis, allowing for a thorough analysis of their interaction under various conditions. The 2-way Fluid Structure Interaction (F.S.I.) between the flow and the mat is achieved by coupling a Finite Element Analysis (F.E.A.) solver in ANSYS with FLUENT. The flow conditions necessary for the structural failure of the

Lipid Biomarkers for a Hypersaline Microbial Mat Community

NASA Technical Reports Server (NTRS)

Jahnke, Linda; Orphan, Victoria; Embaye, Tsegereda; Turk, Kendra; Kubo, Mike; Summons, Roger

2004-01-01

The use of lipid biomarkers and their carbon isotopic compositions are valuable tools for establishing links to ancient microbial ecosystems. Various lipids associated with specific microbial groups can serve as biomarkers for establishing organism source and function in contemporary microbial ecosystems (membrane lipids), and by analogy, potential relevance to ancient organic-rich sedimentary rocks (geolipids). As witnessed by the stromatolite record, benthic microbial mats grew in shallow water lagoonal environments. Our recent work has focused on lipid biomarker analysis of a potential analogue for such ancient mats growing in a set of hypersaline evaporation ponds at Guerrero Negro, Baja California Sur, Mexico. The aerobic, surface layer of this mat (0 to 1 mm) contained a variety of ester-bound fatty acids (FA) representing a diverse bacterial population including cyanobacteria, sulphate reducers (SRB) and heterotrophs. Biomarkers for microeukaryotes detected in this layer included sterols, C-20 polyunsaturated FA and a highly branched isoprenoid, diagnostic for diatoms. Cyanobacteria were also indicated by the presence of a diagnostic set of mid-chain methylalkanes. C-28, to C-34 wax esters (WXE) present in relatively small amounts in the upper 3 mm of the mat are considered biomarkers for green non-sulphur bacteria. Ether-bound isoprenoids were also identified although in considerably lower abundance than ester-bound FA (approx. 1:l0). These complex ether lipids included archatol, hydroxyarchaeol and a C-40 tetraether, all in small amounts. After ether cleavage with boron tribromide, the major recovered isoprenyl was a C-30:1. This C(sub 30;1) yelded squalane after hydrogenation, a known geobiomarker for hypersaline environments in ancient oils and sediments. In this mat, it represents the dominant Archaeal population. The carbon isotopic composition of biomarker lipids were generally depleted relative to the bulk organic material (delta C-13 TOC -10%). Most

Argonne Director Eric Isaacs talks about ARRA funding at Argonne

ScienceCinema

Isaacs, Eric

2018-01-01

Argonne is set to receive over $150 million in stimulus funds. Director Eric Isaacs describes how these funds will be put to good use—hiring employees and contractors, cleaning up the nuclear footprint, and investing in technologies for America's future. More info on Argonne and ARRA here: http://www.anl.gov/recovery/index.html

Eric Hoffer (1902-83) Revisited: Books and Ideas (A Dialogue).

ERIC Educational Resources Information Center

Parker, Franklin; Parker, Betty J.

This paper is structured in the form of a dialog between its two authors. It chronicles the life of Eric Hoffer, a self-taught philosopher and San Francisco longshoreman. Hoffer wrote "The True Believer" (1951), eight other books, and many articles. The paper describes his working life and the influences that led him to write on such…

Lipids of recently-deposited algal mats at Laguna Mormona, Baja California

NASA Technical Reports Server (NTRS)

Cardoso, J.; Brooks, P. W.; Eglinton, G.; Goodfellow, R.; Maxwell, J. R.; Philp, R. P.

1976-01-01

A preliminary survey of the lipid composition of the core of a recently deposited algal mat of a subtropical, hypersaline coastal pond is described. Two layers of the core were examined: the upper, 2-cm-thick layer, comprising the fresh algal mat of predominantly the blue-green species Microcoleus chthonoplastes, and the black anaerobic algal ooze at a depth of 10 cm. About 75% of the n-alkanes in the mat were accounted for by n-C17, with smaller amounts of higher homologues maximizing at n-C27. The ooze was characterized by a bimodal distribution with maxima at n-C17 and n-C27. The n-alkanoic acids distributions were similar to the corresponding n-alkane distributions. A marked decrease in the ratio of monounsaturated to saturated acids in the ooze relative to the mat was observed, which indicates a preferential removal of unsaturated components. Certain triterpenes of the hopane skeletal type were present in the mat and ooze. The presence of stanols and sterenes in the ooze with similar carbon number distributions suggests a relationship between them.

Eric Davidson and deep time.

PubMed

Erwin, Douglas H

2017-10-13

Eric Davidson had a deep and abiding interest in the role developmental mechanisms played in generating evolutionary patterns documented in deep time, from the origin of the euechinoids to the processes responsible for the morphological architectures of major animal clades. Although not an evolutionary biologist, Davidson's interests long preceded the current excitement over comparative evolutionary developmental biology. Here I discuss three aspects at the intersection between his research and evolutionary patterns in deep time: First, understanding the mechanisms of body plan formation, particularly those associated with the early diversification of major metazoan clades. Second, a critique of early claims about ancestral metazoans based on the discoveries of highly conserved genes across bilaterian animals. Third, Davidson's own involvement in paleontology through a collaborative study of the fossil embryos from the Ediacaran Doushantuo Formation in south China.

The MATS Satellite Mission - Tomographic Perspectives on the Mesosphere

NASA Astrophysics Data System (ADS)

Karlsson, B.; Gumbel, J.

2015-12-01

Tomography in combination with space-borne limb imaging opens exciting new ways of probing atmospheric structures. MATS (Mesospheric Airglow/Aerosol Tomography and Spectroscopy) is a new Swedish satellite mission that applies these ideas to the mesosphere. MATS science questions focus on mesospheric wave activity and noctilucent clouds. Primary measurement targets are O2 Atmospheric band dayglow and nightglow in the near infrared (759-767 nm) and sunlight scattered from noctilucent clouds in the ultraviolet (270-300 nm). While tomography provides horizontally and vertically resolved data, spectroscopy allows analysis in terms of mesospheric composition, temperature and cloud properties. This poster introduces instrument and analysis ideas, and discusses scientific perspectives and connections to other missions. MATS is being prepared for a launch in 2018.

Low-Light Anoxygenic Photosynthesis and Fe-S-Biogeochemistry in a Microbial Mat

PubMed Central

Haas, Sebastian; de Beer, Dirk; Klatt, Judith M.; Fink, Artur; Rench, Rebecca McCauley; Hamilton, Trinity L.; Meyer, Volker; Kakuk, Brian; Macalady, Jennifer L.

2018-01-01

We report extremely low-light-adapted anoxygenic photosynthesis in a thick microbial mat in Magical Blue Hole, Abaco Island, The Bahamas. Sulfur cycling was reduced by iron oxides and organic carbon limitation. The mat grows below the halocline/oxycline at 30 m depth on the walls of the flooded sinkhole. In situ irradiance at the mat surface on a sunny December day was between 0.021 and 0.084 μmol photons m-2 s-1, and UV light (<400 nm) was the most abundant part of the spectrum followed by green wavelengths (475–530 nm). We measured a light-dependent carbon uptake rate of 14.5 nmol C cm-2 d-1. A 16S rRNA clone library of the green surface mat layer was dominated (74%) by a cluster (>97% sequence identity) of clones affiliated with Prosthecochloris, a genus within the green sulfur bacteria (GSB), which are obligate anoxygenic phototrophs. Typical photopigments of brown-colored GSB, bacteriochlorophyll e and (β-)isorenieratene, were abundant in mat samples and their absorption properties are well-adapted to harvest light in the available green and possibly even UV-A spectra. Sulfide from the water column (3–6 μmol L-1) was the main source of sulfide to the mat as sulfate reduction rates in the mats were very low (undetectable-99.2 nmol cm-3 d-1). The anoxic water column was oligotrophic and low in dissolved organic carbon (175–228 μmol L-1). High concentrations of pyrite (FeS2; 1–47 μmol cm-3) together with low microbial process rates (sulfate reduction, CO2 fixation) indicate that the mats function as net sulfide sinks mainly by abiotic processes. We suggest that abundant Fe(III) (4.3–22.2 μmol cm-3) is the major source of oxidizing power in the mat, and that abiotic Fe-S-reactions play the main role in pyrite formation. Limitation of sulfate reduction by low organic carbon availability along with the presence of abundant sulfide-scavenging iron oxides considerably slowed down sulfur cycling in these mats. PMID:29755448

Low-Light Anoxygenic Photosynthesis and Fe-S-Biogeochemistry in a Microbial Mat.

PubMed

Haas, Sebastian; de Beer, Dirk; Klatt, Judith M; Fink, Artur; Rench, Rebecca McCauley; Hamilton, Trinity L; Meyer, Volker; Kakuk, Brian; Macalady, Jennifer L

2018-01-01

We report extremely low-light-adapted anoxygenic photosynthesis in a thick microbial mat in Magical Blue Hole, Abaco Island, The Bahamas. Sulfur cycling was reduced by iron oxides and organic carbon limitation. The mat grows below the halocline/oxycline at 30 m depth on the walls of the flooded sinkhole. In situ irradiance at the mat surface on a sunny December day was between 0.021 and 0.084 μmol photons m -2 s -1 , and UV light (<400 nm) was the most abundant part of the spectrum followed by green wavelengths (475-530 nm). We measured a light-dependent carbon uptake rate of 14.5 nmol C cm -2 d -1 . A 16S rRNA clone library of the green surface mat layer was dominated (74%) by a cluster (>97% sequence identity) of clones affiliated with Prosthecochloris , a genus within the green sulfur bacteria (GSB), which are obligate anoxygenic phototrophs. Typical photopigments of brown-colored GSB, bacteriochlorophyll e and (β-)isorenieratene, were abundant in mat samples and their absorption properties are well-adapted to harvest light in the available green and possibly even UV-A spectra. Sulfide from the water column (3-6 μmol L -1 ) was the main source of sulfide to the mat as sulfate reduction rates in the mats were very low (undetectable-99.2 nmol cm -3 d -1 ). The anoxic water column was oligotrophic and low in dissolved organic carbon (175-228 μmol L -1 ). High concentrations of pyrite (FeS 2 ; 1-47 μmol cm -3 ) together with low microbial process rates (sulfate reduction, CO 2 fixation) indicate that the mats function as net sulfide sinks mainly by abiotic processes. We suggest that abundant Fe(III) (4.3-22.2 μmol cm -3 ) is the major source of oxidizing power in the mat, and that abiotic Fe-S-reactions play the main role in pyrite formation. Limitation of sulfate reduction by low organic carbon availability along with the presence of abundant sulfide-scavenging iron oxides considerably slowed down sulfur cycling in these mats.

Colonization of oak wilt fungal mats by Ophiostoma piceae during spring in Minnesota

Treesearch

Jennifer Juzwik; Jason M. Meyer

1997-01-01

The colonization of Ceratocystis fagacearum fungal mats of different ages by Ophiostoma piceae on Quercus spp. was determined in three east-central Minnesota locations during the spring of 1995. The extent of the mat area colonized by O. piceae generally increased with mat age. Subsamples per...

Teaching Geography in American History. ERIC Trends/Issues, Paper No. 1.

ERIC Educational Resources Information Center

Backler, Alan

This ERIC Trends Issues paper highlights the complementary qualities of geography and history and recommends the infusion of geography core themes into high school U.S. history courses. Part 1, "Rationale for Teaching Geography in American History," features information about: (1) overcoming the neglect of geography instruction; (2)…

Instructional Facilities for the Information Age. An ERIC Information Analysis Product.

ERIC Educational Resources Information Center

Knirk, Frederick G.

Intended to assist educators and trainers who must make recommendations about facilities to architects and school authorities, this ERIC information analysis project summarizes research on the design of both classrooms and individualized learning spaces that will optimize learning. Six teaching/learning space topics are considered: (1) light and…

Computer-Based Education. The Best of ERIC, June 1976-August 1980.

ERIC Educational Resources Information Center

Hall, Keith A.

This bibliography contains annotations of reports, reviews, conference proceedings, other documents, and journal articles on computer based education (CBE), most of which were derived from a search of the Educational Resources Information Center (ERIC) system. Covering June 1976 through August 1980, this compilation serves as an update to two…

Bioflumology: Microbial mat growth in flumes

NASA Astrophysics Data System (ADS)

Airo, A.; Weigert, S.; Beck, C.

2014-04-01

The emergence of oxygenic photosynthesis resulted in a transformational change of Earth's geochemical cycles and the subsequent evolution of life. However, it remains vigorously debated when this metabolic ability had evolved in cyanobacteria. This is largely because studies of Archean microfossil morphology, molecular biomarkers, and isotopic characteristics are frequently ambiguous. However, the high degree of morphological similarities between modern photosynthetic and Archean fossil mats has been interpreted to indicate phototactic microbial behavior or oxygenic photosynthesis. In order to better evaluate the relationship between mat morphology and metabolism, we here present a laboratory set-up for conducting month-long experiments in several sterilizable circular flumes designed to allow single-species cyanobacterial growth under adjustable fluid-flow conditions and protected from contamination.

Ecological succession leads to chemosynthesis in mats colonizing wood in sea water.

PubMed

Kalenitchenko, Dimitri; Dupraz, Marlène; Le Bris, Nadine; Petetin, Carole; Rose, Christophe; West, Nyree J; Galand, Pierre E

2016-09-01

Chemosynthetic mats involved in cycling sulfur compounds are often found in hydrothermal vents, cold seeps and whale falls. However, there are only few records of wood fall mats, even though the presence of hydrogen sulfide at the wood surface should create a perfect niche for sulfide-oxidizing bacteria. Here we report the growth of microbial mats on wood incubated under conditions that simulate the Mediterranean deep-sea temperature and darkness. We used amplicon and metagenomic sequencing combined with fluorescence in situ hybridization to test whether a microbial succession occurs during mat formation and whether the wood fall mats present chemosynthetic features. We show that the wood surface was first colonized by sulfide-oxidizing bacteria belonging to the Arcobacter genus after only 30 days of immersion. Subsequently, the number of sulfate reducers increased and the dominant Arcobacter phylotype changed. The ecological succession was reflected by a change in the metabolic potential of the community from chemolithoheterotrophs to potential chemolithoautotrophs. Our work provides clear evidence for the chemosynthetic nature of wood fall ecosystems and demonstrates the utility to develop experimental incubation in the laboratory to study deep-sea chemosynthetic mats.

Enhanced antibacterial nanocomposite mats by coaxial electrospinning of polycaprolactone fibers loaded with Zn-based nanoparticles.

PubMed

Prado-Prone, Gina; Silva-Bermudez, Phaedra; Almaguer-Flores, Argelia; García-Macedo, Jorge A; García, Victor I; Rodil, Sandra E; Ibarra, Clemente; Velasquillo, Cristina

2018-04-16

ZnO and Zn acetate nanoparticles were embedded in polycaprolactone coaxial-fibers and uniaxial-fibers matrices to develop potential antibacterial nanocomposite wound dressings (mats). Morphology, composition, wettability, crystallinity and fiber structure of mats were characterized. Antibacterial properties of mats were tested against E. coli and S. aureus by turbidity and MTT assays. The effect of UVA illumination (prior to bacteria inoculation) on mats' antibacterial activity was also studied. Results showed that a coaxial-fibers design maintained nanoparticles distributed in the outer-shell of fibers and, in general, enhanced the antibacterial effect of the mats, in comparison to conventional uniaxial-fibers mats. Results indicated that mats simultaneously inhibited planktonic and biofilm bacterial growth by, probably, two main antibacterial mechanisms; 1) release of Zn 2+ ions (mainly from Zn acetate nanoparticles) and 2) photocatalytic oxidative processes exerted by ZnO nanoparticles. Antibacterial properties of mats were significantly improved by coaxial-fibers design and exposure to UVA-light prior to bacteria inoculation. Copyright © 2018 Elsevier Inc. All rights reserved.

B-Scan Based Acoustic Source Reconstruction for Magnetoacoustic Tomography with Magnetic Induction (MAT-MI)

PubMed Central

Mariappan, Leo; Li, Xu; He, Bin

2011-01-01

We present in this study an acoustic source reconstruction method using focused transducer with B mode imaging for magnetoacoustic tomography with magnetic induction (MAT-MI). MAT-MI is an imaging modality proposed for non-invasive conductivity imaging with high spatial resolution. In MAT-MI acoustic sources are generated in a conductive object by placing it in a static and a time-varying magnetic field. The acoustic waves from these sources propagate in all directions and are collected with transducers placed around the object. The collected signal is then usedto reconstruct the acoustic source distribution and to further estimate the electrical conductivity distribution of the object. A flat piston transducer acting as a point receiver has been used in previous MAT-MI systems to collect acoustic signals. In the present study we propose to use B mode scan scheme with a focused transducer that gives a signal gain in its focus region and improves the MAT-MI signal quality. A simulation protocol that can take into account different transducer designs and scan schemes for MAT-MI imaging is developed and used in our evaluation of different MAT-MI system designs. It is shown in our computer simulations that, as compared to the previous approach, the MAT-MI system using B-scan with a focused transducer allows MAT-MI imaging at a closer distance and has improved system sensitivity. In addition, the B scan imaging technique allows reconstruction of the MAT-MI acoustic sources with a discrete number of scanning locations which greatly increases the applicability of the MAT-MI approach especially when a continuous acoustic window is not available in real clinical applications. We have also conducted phantom experiments to evaluate the proposed method and the reconstructed image shows a good agreement with the target phantom. PMID:21097372

Thermoelectric Properties of Poly(3-Hexylthiophene) Nanofiber Mat with a Large Void Fraction.

PubMed

Hiura, Shogo; Okada, Naoki; Wakui, Junma; Narita, Hikari; Kanehashi, Shinji; Shimomura, Takeshi

2017-04-28

The thermoelectric properties of a poly(3-hexylthiophene) (P3HT) nanofiber mat which has higher crystallinity-and thus exhibits larger carrier mobility-than a non-fibrous P3HT film, were investigated. No significant difference was observed in the maximum values of the power factor between the P3HT nanofiber mat and the P3HT film. However, the thermal conductivity of the nanofiber mat was less than half that of the film despite having almost the same electrical conductivity. This higher thermoelectric property of the nanofiber mat than the film is attributed to the existence of highly effective conducting pathways and a large void fraction, and the result means that the nanofiber mat was a good candidate for use as a thermoelectric material.

The Next Big Thing - Eric Haseltine

DOE Office of Scientific and Technical Information (OSTI.GOV)

Eric Haseltine

2009-09-16

Eric Haseltine, Haseltine Partners president and former chief of Walt Disney Imagineering, presented "The Next Big Thing," on Sept. 11, at the ORNL. He described the four "early warning signs" that a scientific breakthrough is imminent, and then suggested practical ways to turn these insights into breakthrough innovations. Haseltine is former director of research at the National Security Agency and associate director for science and technology for the director of National Intelligence, former executive vice president of Walt Disney Imagineering and director of engineering for Hughes Aircraft. He has 15 patents in optics, special effects and electronic media, and moremore » than 100 publications in science and technical journals, the web and Discover Magazine.« less

The Next Big Thing - Eric Haseltine

ScienceCinema

Eric Haseltine

2017-12-09

Eric Haseltine, Haseltine Partners president and former chief of Walt Disney Imagineering, presented "The Next Big Thing," on Sept. 11, at the ORNL. He described the four "early warning signs" that a scientific breakthrough is imminent, and then suggested practical ways to turn these insights into breakthrough innovations. Haseltine is former director of research at the National Security Agency and associate director for science and technology for the director of National Intelligence, former executive vice president of Walt Disney Imagineering and director of engineering for Hughes Aircraft. He has 15 patents in optics, special effects and electronic media, and more than 100 publications in science and technical journals, the web and Discover Magazine.

Carbonate mineralisation in sabkha microbial mats; a comparative study of field and laboratory systems

NASA Astrophysics Data System (ADS)

Dutton, Kirsten E.; Paul, Andreas; Lessa Andrade, Luiza; Sherry, Angela; Lokier, Stephen; Head, Ian M.; van der Land, Cees

2017-04-01

Microbial mats and their lithified counterparts are some of the earliest evidence of life on Earth. The coastal sabkha in Abu Dhabi, United Arab Emirates, is a modern setting where microbial mats flourish in a hypersaline and arid environment. These microbial communities are composed of microbes such as cyanobacteria, thermoplasmata and sulphate-reducing bacteria. The mats thrive as they are protected from predators, which are excluded by the extreme environmental conditions. Microbial mats are highly reactive to change, with their microbial communities and geochemistry varying on a millimetre scale, likely controlling mineralisation processes. Exact carbonate mineralisation rates within coastal sabkha microbial mats have not to date been quantified. Defining the mineralisation pathways and knowledge of precise mineralisation rates will help to explain how these organosedimentary structures are retained in the rock record. A fundamental understanding of the role of microbial mats in the formation of different carbonate phases is important, yet there are also other practical implications. For example, structures observed in core from the oil-bearing Arab Formation have been likened to modern microbial mats in terms of structure and mineralogy. The depositional configuration and primary mineralogy generated by microbial mats may control syndepositional lithification and later diagenesis thereby influencing reservoir porosity and permeability. In order to constrain factors effecting mineralisation and early lithification, experimentation in a controlled laboratory environment is required. Parameters for experimentation have been established during fieldwork and were applied to a tank-based laboratory simulation of sabkha microbial mats. These parameters include light, salinity and cation and anion water chemistry, gas production chemistry and vertical mat growth. Parameters were measured weekly with sampling for mineralogical and microbial community analysis on a

Carbon nanotube mat as mediator-less glucose sensor electrode.

PubMed

Ryu, Jongeun; Kim, Hansang; Lee, Sangeui; Hahn, H Thomas; Lashmore, David

2010-02-01

In this paper, the direct electron transfer of glucose oxidase (GOx) on carbon nanotube (CNT) mat electrode is demonstrated. Because of the electrical conductivity and mechanical strength of CNT mat, it can be used as an electrode as well as a catalyst support. Therefore, the preparation process for the CNT mat based sensor electrode is simpler than that of the conventional CNT dispersed sensor electrodes. GOx was covalently immobilized on the oxidized CNT mat, which is connected to a wire by using silver paste and epoxy glue. Attenuated Total Reflectance Fourier Transform-Infrared (ATR-FTIR) result shows transmittance peaks at 1637 cm(-1) and 1525 cm(-1) which are corresponding to the band I and II of amide. Cyclic voltammetric shows a pair of well-defined redox peaks with the average formal potential of -0.425 V (vs. Ag/AgCl reference electrode) in the phosphate buffered saline solution (1 x PBS, pH 7.4). Calculated electron transfer rate constant and the surface density of GOx were 1.71 s(-1) and (3.27 +/- 0.20) x 10(-13) mol/cm2, respectively. Cyclic voltammograms of GOx-CNT mat in glucose solution show that the immobilized GOx retains its catalytic activity to glucose. The amperometric sensor response showed a linear dependence on the glucose concentration in the range of 0.2 mM to 2.18 mM with a detection sensitivity of 4.05 microA mM(-1) cm(-2). The Michaelis-Menten constant of the immobilized GOx was calculated to be 2.18 mM.

Photosynthesis below the surface in a cryptic microbial mat

NASA Astrophysics Data System (ADS)

Rothschild, Lynn J.; Giver, Lorraine J.

2002-10-01

The discovery of subsurface communities has encouraged speculation that such communities might be present on planetary bodies exposed to harsh surface conditions, including the early Earth. While the astrobiology community has focused on the deep subsurface, near-subsurface environments are unique in that they provide some protection while allowing partial access to photosynthetically active radiation. Previously we identified near-surface microbial communities based on photosynthesis. Here we assess the productivity of such an ecosystem by measuring in situ carbon fixation rates in an intertidal marine beach through a diurnal cycle, and find them surprisingly productive. Gross fixation along a transect (99×1 m) perpendicular to the shore was highly variable and depended on factors such as moisture and mat type, with a mean of ~41 mg C fixed m[minus sign]2 day[minus sign]1. In contrast, an adjacent well-established cyanobacterial mat dominated by Lyngbya aestuarii was ~12 times as productive (~500 mg C fixed m[minus sign]2 day[minus sign]1). Measurements made of the Lyngbya mat at several times per year revealed a correlation between total hours of daylight and gross daily production. From these data, annual gross fixation was estimated for the Lyngbya mat and yielded a value of ~1.3×105 g m[minus sign]2 yr[minus sign]1. An analysis of pulse-chase data obtained in the study in conjunction with published literature on similar ecosystems suggests that subsurface interstitial mats may be an overlooked endogenous source of organic carbon, mostly in the form of excreted fixed carbon.

Alpha Matting with KL-Divergence Based Sparse Sampling.

PubMed

Karacan, Levent; Erdem, Aykut; Erdem, Erkut

2017-06-22

In this paper, we present a new sampling-based alpha matting approach for the accurate estimation of foreground and background layers of an image. Previous sampling-based methods typically rely on certain heuristics in collecting representative samples from known regions, and thus their performance deteriorates if the underlying assumptions are not satisfied. To alleviate this, we take an entirely new approach and formulate sampling as a sparse subset selection problem where we propose to pick a small set of candidate samples that best explains the unknown pixels. Moreover, we describe a new dissimilarity measure for comparing two samples which is based on KLdivergence between the distributions of features extracted in the vicinity of the samples. The proposed framework is general and could be easily extended to video matting by additionally taking temporal information into account in the sampling process. Evaluation on standard benchmark datasets for image and video matting demonstrates that our approach provides more accurate results compared to the state-of-the-art methods.

Overcoming Risk: An Annotated Bibliography of Publications Developed by ERIC Clearinghouses.

ERIC Educational Resources Information Center

Schwartz, Wendy, Ed.; Howley, Craig, Ed.

This publication contains two essays and an annotated bibliography of publications about risk. The entries in the bibliography were produced by the various clearinghouses in the ERIC system. The first essay, "Who Is at Risk? Definitions, Demographics, and Decisions," by Aaron M. Pallas, categorizes personal, family, and environmental factors that…

Astronaut Jan Davis monitors Commercial Protein Crystal Growth experiment

NASA Image and Video Library

1994-02-03

STS060-21-031 (3-11 Feb 1994) --- Using a lap top computer, astronaut N. Jan Davis monitors systems for the Commercial Protein Crystal Growth (CPCG) experiment onboard the Space Shuttle Discovery. Davis joined four other NASA astronauts and a Russian cosmonaut for eight days in space aboard Discovery.

Freedom of Speech: A Clear and Present Need to Teach. ERIC Report.

ERIC Educational Resources Information Center

Boileau, Don M.

1983-01-01

Presents annotations of 21 documents in the ERIC system on the following subjects: (1) theory of freedom of speech; (2) theorists; (3) research on freedom of speech; (4) broadcasting and freedom of speech; and (5) international questions of freedom of speech. (PD)

Electrospun poly(methyl methacrylate) fibrous mat showing piezoelectric properties

NASA Astrophysics Data System (ADS)

Nobeshima, Taiki; Ishii, Yuya; Sakai, Heisuke; Uemura, Sei; Yoshida, Manabu

2018-05-01

A piezoelectric effect, such as actuation behavior with voltage application, could be observed from a poly(methyl methacrylate) (PMMA) fibrous mat fabricated by electrospinning. This fibrous mat increased or decreased its thickness in accordance with the polarity of the applied voltage, which appears to be an inverse piezoelectric effect. The appearance d T constant was as large as 8.5 nm/V owing to the softness of the fibrous structure, and the coupling constant K T = 0.31 indicated its efficient piezoelectric property. This piezoelectric behavior was repeatedly observed to be stable at room temperature. In addition, the polarization components of the fibrous mat, which are considered to be the origin of its piezoelectric effect, and its relaxation behavior were confirmed from the results of thermally stimulated current measurements.

Antimicrobial Activity of Silver Ions Released from Zeolites Immobilized on Cellulose Nanofiber Mats.

PubMed

Rieger, Katrina A; Cho, Hong Je; Yeung, Hiu Fai; Fan, Wei; Schiffman, Jessica D

2016-02-10

In this study, we exploit the high silver ion exchange capability of Linde Type A (LTA) zeolites and present, for the first time, electrospun nanofiber mats decorated with in-house synthesized silver (Ag(+)) ion exchanged zeolites that function as molecular delivery vehicles. LTA-Large zeolites with a particle size of 6.0 μm were grown on the surface of the cellulose nanofiber mats, whereas LTA-Small zeolites (0.2 μm) and three-dimensionally ordered mesoporous-imprinted (LTA-Meso) zeolites (0.5 μm) were attached to the surface of the cellulose nanofiber mats postsynthesis. After the three zeolite/nanofiber mat assemblies were ion-exchanged with Ag(+) ions, their ion release profiles and ability to inactivate Escherichia coli (E. coli) K12 were evaluated as a function of time. LTA-Large zeolites immobilized on the nanofiber mats displayed more than an 11 times greater E. coli K12 inactivation than the Ag-LTA-Large zeolites that were not immobilized on the nanofiber mats. This study demonstrates that by decorating nanometer to micrometer scale Ag(+) ion-exchanged zeolites on the surface of high porosity, hydrophilic cellulose nanofiber mats, we can achieve a tunable release of Ag(+) ions that inactivate bacteria faster and are more practical to use in applications over powder zeolites.

Organismal and spatial partitioning of energy and macronutrient transformations within a hypersaline mat

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mobberley, Jennifer M.; Lindemann, Stephen R.; Bernstein, Hans C.

2017-03-21

Phototrophic mat communities are model ecosystems for studying energy cycling and elemental transformations because complete biogeochemical cycles occur over millimeter-to-centimeter scales. Characterization of energy and nutrient capture within hypersaline phototrophic mats has focused on specific processes and organisms, however little is known about community-wide distribution of and linkages between these processes. To investigate energy and macronutrient capture and flow through a structured community, the spatial and organismal distribution of metabolic functions within a compact hypersaline mat community from Hot Lake have been broadly elucidated through species-resolved metagenomics and geochemical, microbial diversity, and metabolic gradient measurements. Draft reconstructed genomes of abundantmore » organisms revealed three dominant cyanobacterial populations differentially distributed across the top layers of the mat suggesting niche separation along light and oxygen gradients. Many organisms contained diverse functional profiles, allowing for metabolic response to changing conditions within the mat. Organisms with partial nitrogen and sulfur metabolisms were widespread indicating dependence upon metabolite exchange. In addition, changes in community spatial structure were observed over the diel. These results indicate that organisms within the mat community have adapted to the temporally dynamic environmental gradients in this hypersaline mat through metabolic flexibility and fluid syntrophic interactions, including shifts in spatial arrangements.« less

Niche differentiation of bacterial communities at a millimeter scale in Shark Bay microbial mats

NASA Astrophysics Data System (ADS)

Wong, Hon Lun; Smith, Daniela-Lee; Visscher, Pieter T.; Burns, Brendan P.

2015-10-01

Modern microbial mats can provide key insights into early Earth ecosystems, and Shark Bay, Australia, holds one of the best examples of these systems. Identifying the spatial distribution of microorganisms with mat depth facilitates a greater understanding of specific niches and potentially novel microbial interactions. High throughput sequencing coupled with elemental analyses and biogeochemical measurements of two distinct mat types (smooth and pustular) at a millimeter scale were undertaken in the present study. A total of 8,263,982 16S rRNA gene sequences were obtained, which were affiliated to 58 bacterial and candidate phyla. The surface of both mats were dominated by Cyanobacteria, accompanied with known or putative members of Alphaproteobacteria and Bacteroidetes. The deeper anoxic layers of smooth mats were dominated by Chloroflexi, while Alphaproteobacteria dominated the lower layers of pustular mats. In situ microelectrode measurements revealed smooth mats have a steeper profile of O2 and H2S concentrations, as well as higher oxygen production, consumption, and sulfate reduction rates. Specific elements (Mo, Mg, Mn, Fe, V, P) could be correlated with specific mat types and putative phylogenetic groups. Models are proposed for these systems suggesting putative surface anoxic niches, differential nitrogen fixing niches, and those coupled with methane metabolism.

Interaction of gelatin with polyenes modulates antifungal activity and biocompatibility of electrospun fiber mats

PubMed Central

Lakshminarayanan, Rajamani; Sridhar, Radhakrishnan; Loh, Xian Jun; Nandhakumar, Muruganantham; Barathi, Veluchamy Amutha; Kalaipriya, Madhaiyan; Kwan, Jia Lin; Liu, Shou Ping; Beuerman, Roger Wilmer; Ramakrishna, Seeram

2014-01-01

Topical application of antifungals does not have predictable or well-controlled release characteristics and requires reapplication to achieve therapeutic local concentration in a reasonable time period. In this article, the efficacy of five different US Food and Drug Administration-approved antifungal-loaded (amphotericin B, natamycin, terbinafine, fluconazole, and itraconazole) electrospun gelatin fiber mats were compared. Morphological studies show that incorporation of polyenes resulted in a two-fold increase in fiber diameter and the mats inhibit the growth of yeasts and filamentous fungal pathogens. Terbinafine-loaded mats were effective against three filamentous fungal species. Among the two azole antifungals compared, the itraconazole-loaded mat was potent against Aspergillus strains. However, activity loss was observed for fluconazole-loaded mats against all of the test organisms. The polyene-loaded mats displayed rapid candidacidal activities as well. Biophysical and rheological measurements indicate strong interactions between polyene antifungals and gelatin matrix. As a result, the polyenes stabilized the triple helical conformation of gelatin and the presence of gelatin decreased the hemolytic activity of polyenes. The polyene-loaded fiber mats were noncytotoxic to primary human corneal and sclera fibroblasts. The reduction of toxicity with complete retention of activity of the polyene antifungal-loaded gelatin fiber mats can provide new opportunities in the management of superficial skin infections. PMID:24920895

Geochemistry of NE Atlantic non-rifting zones, Iceland and Jan Mayen

NASA Astrophysics Data System (ADS)

Tronnes, R. G.; Waight, T.

2005-12-01

The fertile components of the NE Atlantic mantle are sampled preferentially by alkaline basalts in the volcanic flank zones of Iceland and in the Jan Mayen and Vesteris seamount areas. Our data from primitive flank zone lavas from Iceland and Jan Mayen demonstrate a HIMU-affinity with enrichment of HFSE, U/Pb, Th/U and Nb/Th. In PM-normalized spider diagrams the least enriched samples have weakly positive Sr-anomalies, whereas the most enriched samples have negative Sr-anomalies. The entire sample suite shows negative Sr-Nd-isotope correlation, whereas the samples of each volcanic system or flank zone generally lack such a correlation. Our data confirm the anomalously high 87/86Sr of the Orafajokull volcanic system in the eastern flank zone. The results are consistent with existing data for other primitive flank zone basalts from Iceland and Jan Mayen. Common geochemical features linking alkaline flank zone basalts and high-degree tholeiitic melts include high 87/86Sr (and probably 176/177Hf) for a given 143/144Nd, negative delta-207Pb (except for Orafajokull) and positive delta-Nb. Alkaline flank zone basalts have generally higher 87/86Sr, 206/204Pb and 18/16O and lower 143/144Nd, 187/188Os and 3/4He than rift zone tholeiites. The different 18/16O ratios in flank and rift zone basalts are consistent with seafloor hydrothermal alteration of the upper and lower parts of recycled oceanic lithosphere, respectively. Olivine-melt fractionation may contribute to the difference. Indications of lower 187/188Os in alkaline basalts compared to nearby rift zone tholeiites could be caused by subduction zone loss of Re from the upper part of recycled slabs. The partial melting and volcanic sampling of the fertile mantle components under Iceland and the NE Atlantic is governed by the crustal structure and geometry of the Icelandic volcanic zones and the lateral deflection of the upwelling heterogeneous mantle source originating under central Iceland. Based on the pattern of V

Bacterial Diversity in Microbial Mats and Sediments from the Atacama Desert.

PubMed

Rasuk, Maria Cecilia; Fernández, Ana Beatriz; Kurth, Daniel; Contreras, Manuel; Novoa, Fernando; Poiré, Daniel; Farías, María Eugenia

2016-01-01

The Atacama Desert has extreme environmental conditions that allow the development of unique microbial communities. The present paper reports the bacterial diversity of microbial mats and sediments and its mineralogical components. Some physicochemical conditions of the water surrounding these ecosystems have also been studied trying to determine their influence on the diversity of these communities. In that way, mats and sediments distributed among different hypersaline lakes located in salt flats of the Atacama Desert were subjected to massive parallel sequencing of the V4 region of the 16S rRNA genes of Bacteria. A higher diversity in sediment than in mat samples have been found. Lakes that harbor microbial mats have higher salinity than lakes where mats are absent. Proteobacteria and/or Bacteroidetes are the major phyla represented in all samples. An interesting item is the finding of a low proportion or absence of Cyanobacteria sequences in the ecosystems studied, suggesting the possibility that other groups may be playing an essential role as primary producers in these extreme environments. Additionally, the large proportion of 16S rRNA gene sequences that could not be classified at the level of phylum indicates potential new phyla present in these ecosystems.

Investigation of needleless electrospun PAN nanofiber mats

NASA Astrophysics Data System (ADS)

Sabantina, Lilia; Mirasol, José Rodríguez; Cordero, Tomás; Finsterbusch, Karin; Ehrmann, Andrea

2018-04-01

Polyacrylonitrile (PAN) can be spun from a nontoxic solvent (DMSO, dimethyl sulfoxide) and is nevertheless waterproof, opposite to the biopolymers which are spinnable from aqueous solutions. This makes PAN an interesting material for electrospinning nanofiber mats which can be used for diverse biotechnological or medical applications, such as filters, cell growth, wound healing or tissue engineering. On the other hand, PAN is a typical base material for producing carbon nanofibers. Nevertheless, electrospinning PAN necessitates convenient spinning parameters to create nanofibers without too many membranes or agglomerations. Thus we have studied the influence of spinning parameters on the needleless electrospinning process of PAN dissolved in DMSO and the resulting nanofiber mats.

Selected properties of MDF and flakeboard overlaid with fiberglass mats

Treesearch

Zhiyong Cai

2006-01-01

Nonwoven fiberglass face laminates have long been applied to consolidated wood- based composites to improve their performance and serviceability. In this study, fiberglass mats with 50 percent resin binder were applied as face laminates to unconsolidated wood fiber or flake mats, then hot-pressed to make overlaid medium density fiberboard and flakeboard. Fiberglass...

The Student as Commuter: Developing a Comprehensive Institutional Response. ERIC Digest.

ERIC Educational Resources Information Center

Jacoby, Barbara

A preview is given of ASHE-ERIC report no. 7 which focuses on commuting students at colleges and universities and how institutions of higher education can begin to respond to these students' special circumstances that are greatly affecting their educational experience. The diversity of commuter students and their educational goals requires the use…

JiJi De GuanJiao FangFa (Positive Discipline). ERIC Digest.

ERIC Educational Resources Information Center

ERIC Clearinghouse on Elementary and Early Childhood Education, Champaign, IL.

This ERIC Digest suggests methods and language that can be used in handling difficult, but common, situations involving young children. Discussion focuses on: (1) 12 methods of discipline that promote self-worth; (2) the process of creating a positive climate that promotes self-discipline; (3) harmful and negative disciplinary methods; and (4)…

The Architecture of Iron Microbial Mats Reflects the Adaptation of Chemolithotrophic Iron Oxidation in Freshwater and Marine Environments

PubMed Central

Chan, Clara S.; McAllister, Sean M.; Leavitt, Anna H.; Glazer, Brian T.; Krepski, Sean T.; Emerson, David

2016-01-01

Microbes form mats with architectures that promote efficient metabolism within a particular physicochemical environment, thus studying mat structure helps us understand ecophysiology. Despite much research on chemolithotrophic Fe-oxidizing bacteria, Fe mat architecture has not been visualized because these delicate structures are easily disrupted. There are striking similarities between the biominerals that comprise freshwater and marine Fe mats, made by Beta- and Zetaproteobacteria, respectively. If these biominerals are assembled into mat structures with similar functional morphology, this would suggest that mat architecture is adapted to serve roles specific to Fe oxidation. To evaluate this, we combined light, confocal, and scanning electron microscopy of intact Fe microbial mats with experiments on sheath formation in culture, in order to understand mat developmental history and subsequently evaluate the connection between Fe oxidation and mat morphology. We sampled a freshwater sheath mat from Maine and marine stalk and sheath mats from Loihi Seamount hydrothermal vents, Hawaii. Mat morphology correlated to niche: stalks formed in steeper O2 gradients while sheaths were associated with low to undetectable O2 gradients. Fe-biomineralized filaments, twisted stalks or hollow sheaths, formed the highly porous framework of each mat. The mat-formers are keystone species, with nascent marine stalk-rich mats comprised of novel and uncommon Zetaproteobacteria. For all mats, filaments were locally highly parallel with similar morphologies, indicating that cells were synchronously tracking a chemical or physical cue. In the freshwater mat, cells inhabited sheath ends at the growing edge of the mat. Correspondingly, time lapse culture imaging showed that sheaths are made like stalks, with cells rapidly leaving behind an Fe oxide filament. The distinctive architecture common to all observed Fe mats appears to serve specific functions related to chemolithotrophic Fe

Jan Hudde and the Quotient Rule before Newton and Leibniz

ERIC Educational Resources Information Center

Curtin, Daniel J.

2005-01-01

This article describes some of the work of Jan Hudde who anticipated some results of calculus. Prior to a career as a Burgomaster of Amsterdam, Hudde engaged in mathematics. His method of finding maxima and minima is especially interesting.

The calcium carbonate saturation state in cyanobacterial mats throughout Earth’s history

NASA Astrophysics Data System (ADS)

Aloisi, Giovanni

2008-12-01

Through early lithification, cyanobacterial mats produced vast amounts of CaCO 3 on Precambrian carbonate platforms (before 540 Myr ago). The superposition of lithified cyanobacterial mats forms internally laminated, macroscopic structures known as stromatolites. Similar structures can be important constituents of Phanerozoic carbonate platforms (540 Myr to present). Early lithification in modern marine cyanobacterial mats is thought to be driven by a metabolically-induced increase of the CaCO 3 saturation state ( Ω) in the mat. However, it is uncertain which microbial processes produce the Ω increase and to which extent similar Ω shifts were possible in Precambrian oceans whose chemistry differed from that of the modern ocean. I developed a numerical model that calculates Ω in cyanobacterial mats and used it to tackle these questions. The model is first applied to simulate Ω in modern calcifying cyanobacterial mats forming at Highborne Cay (Bahamas); it shows that while cyanobacterial photosynthesis increases Ω considerably, sulphate reduction has a small and opposite effect on mat Ω because it is coupled to H 2S oxidation with O 2 which produces acidity. Numerical experiments show that the magnitude of the Ω increase is proportional to DIC in DIC-limited waters (DIC < 3-10 mM), is proportional to pH when ambient water DIC is not limiting and always proportional to the concentration of Ca 2+ in ambient waters. With oceanic Ca 2+ concentrations greater than a few millimolar, an appreciable increase in Ω occurs in mats under a wide range of environmental conditions, including those supposed to exist in the oceans of the past 2.8 Gyr. The likely lithological expression is the formation of the microsparitic stromatolite microtexture—indicative of CaCO 3 precipitation within the mats under the control of microbial activity—which is found in carbonate rocks spanning from the Precambrian to recent. The model highlights the potential for an increase in the

IPM Analysis of the Final Mercury and Air Toxics Standards (MATS)

EPA Pesticide Factsheets

EPA used version 4.10_MATS of the Integrated Planning Model (IPM) to analyze the impact of the Mercury and Air Toxics Standards (MATS) rule on the U.S. electric power sector. Learn about the results and view links to documentation.

The Extracellular Matrix in Photosynthetic Mats: A Cyanobacterial Gingerbread House

NASA Astrophysics Data System (ADS)

Stuart, R.; Stannard, W.; Bebout, B.; Pett-Ridge, J.; Mayali, X.; Weber, P. K.; Lipton, M. S.; Lee, J.; Everroad, R. C.; Thelen, M.

2014-12-01

Hypersaline laminated cyanobacterial mats are excellent model systems for investigating photoautotrophic contributions to biogeochemical cycling on a millimeter scale. These self-sustaining ecosystems are characterized by steep physiochemical gradients that fluctuate dramatically on hour timescales, providing a dynamic environment to study microbial response. However, elucidating the distribution of energy from light absorption into biomass requires a complete understanding of the various constituents of the mat. Extracellular polymeric substances (EPS), which can be composed of proteins, polysaccharides, lipids and DNA are a major component of these mats and may function in the redistribution of nutrients and metabolites within the community. To test this notion, we established a model mat-building culture for comparison with the phylogenetically diverse natural mat communities. In these two systems we determined how proteins and glycans in the matrix changed as a function of light and tracked nutrient flow from the matrix. Using mass spectrometry metaproteomics analysis, we found homologous proteins in both field and culture extracellular matrix that point to cyanobacterial turnover of amino acids, inorganic nutrients, carbohydrates and nucleic acids from the EPS. Other abundant functions identified included oxidative stress response from both the cyanobacteria and heterotrophs and cyanobacterial structural proteins that may play a role in mat cohesion. Several degradative enzymes also varied in abundance in the EPS in response to light availability, suggesting active secretion. To further test cyanobacterial EPS turnover, we generated isotopically-labeled EPS and used NanoSIMS to trace uptake of this labeled EPS. Our findings suggest Cyanobacteria may facilitate nutrient transfer to other groups, as well as uptake of their own products through degradation of EPS components. This work provides evidence for the essential roles of EPS for storage, structural

Sedimentary Parameters Controlling Occurrence and Preservation of Microbial Mats in Siliciclastic Depositional Systems

NASA Technical Reports Server (NTRS)

Noffke, Nora; Knoll, Andrew H.

2001-01-01

Shallow-marine, siliciclastic depositional systems are governed by physical sedimentary processes. Mineral precipitation or penecontemporaneous cementation play minor roles. Today, coastal siliciclastic environments may be colonized by a variety of epibenthic, mat-forming cyanobacteria. Studies on microbial mats showed that they are not randomly distributed in modern tidal environments. Distribution and abundancy is mainly function of a particular sedimentary facies. Fine-grained sands composed of "clear" (translucent) quartz particles constitute preferred substrates for cyanobacteria. Mat-builders also favor sites characterized by moderate hydrodynamic flow regimes, which permit biomass enrichment and construction of mat fabrics without lethal burial of mat populations by fine sediments. A comparable facies relationship can be observed in ancient siliciclastic shelf successions from the terminal Neoproterozoic Nama Group, Namibia. Wrinkle structures that record microbial mats are present but sparsely distributed in mid- to inner shelf sandstones of the Nudaus Formation. The sporadic distribution of these structures reflects both the narrow ecological window that governs mat development and the distinctive taphonomic conditions needed to preserve the structures. These observations caution that statements about changing mat abundance across the Proterozoic-Cambrian boundary must be firmly rooted in paleoenvironmental and taphonomic analysis. Understanding the factors that influence the formation and preservation of microbial structures in siliciclastic regimes can facilitate exploration for biological signatures in Earth's oldest rocks. Moreover, insofar as these structures can be preserved on bedding surfaces and are not easily mimicked by physical processes, they constitute a set of biological markers that can be searched for on Mars by remotely controlled rovers.

STS-133 crew members Lindsey, Boe and Drew during Tool/Repair Kits training with instructor

NASA Image and Video Library

2010-01-26

JSC2010-E-014267 (26 Jan. 2010) --- NASA astronauts Steve Lindsey (center), STS-133 commander; Eric Boe (left), pilot; and Alvin Drew, mission specialist, participate in an ISS tools and repair kits training session in the Space Vehicle Mock-up Facility at NASA's Johnson Space Center.

Urinary Concentrations of Polycyclic Aromatic Hydrocarbon Metabolites in Maté Drinkers in Rio Grande do Sul, Brazil

PubMed Central

Lopes, Antonio Barros; Metzdorf, Marcela; Metzdorf, Luiza; Ramalho, Marcos Paulo; Kavalco, Caroline; Etemadi, Arash; Pritchett, Natalie R.; Murphy, Gwen; Calafat, Antonia M.; Abnet, Christian C.; Dawsey, Sanford M.; Fagundes, Renato Borges

2017-01-01

Background Consumption of maté, an infusion of the herb Ilex paraguariensis (yerba maté), is associated with increased risk of esophageal squamous cell carcinoma (ESCC), but the carcinogenic mechanism is unclear. Commercial brands of yerba maté contain high levels of carcinogenic polycyclic aromatic hydrocarbons (PAHs), which are acquired during the traditional drying process. The purpose of this study was to characterize exposure to PAHs in maté drinkers over a wide range of maté consumption. Methods We recruited 244 adults who answered a questionnaire and collected a fasting spot urine specimen. We quantified urinary concentrations of seven PAH metabolites, and assessed associations between self-reported recent maté consumption and urinary PAH metabolites by multivariate regression. Results Recent maté consumption showed a significant dose-response association with 6 of 7 PAH metabolites in unadjusted models (p-for-trend <0.05). After adjustment for creatinine and potential confounders, concentrations of 2-naphthol, 1-hydroxyphenanthrene, and the sum of 2- and 3-hydroxyphenanthrene remained significantly associated with recent maté intake. The sum of the urinary concentrations of the phenanthrene metabolites was similar or higher among maté drinkers who did not smoke than among smokers who did not drink maté. Conclusions Urinary concentrations of PAH metabolites were significantly associated with self-reported amount of recent maté intake, and drinking maté increased urinary concentrations of some PAH metabolites as much as smoking cigarettes. Impact Drinking maté is a source of exposure to potentially carcinogenic PAHs, consistent with the hypothesis that the PAH content of maté may contribute to the increased risk of ESCC in maté drinkers. PMID:29263183

Toolbox for the Modeling and Analysis of Thermodynamic Systems (T-MATS) Users' Workshop Presentations

NASA Technical Reports Server (NTRS)

Litt, Jonathan S. (Compiler)

2018-01-01

NASA Glenn Research Center hosted a Users' Workshop on the Toolbox for the Modeling and Analysis of Thermodynamic Systems (T-MATS) on August 21, 2017. The objective of this workshop was to update the user community on the latest features of T-MATS, and to provide a forum to present work performed using T-MATS. Presentations highlighted creative applications and the development of new features and libraries, and emphasized the flexibility and simulation power of T-MATS.

4. Historic American Buildings Survey, Nelson E. Baldwin, Photographer, Jan. ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

4. Historic American Buildings Survey, Nelson E. Baldwin, Photographer, Jan. 16, 1937, View - Second to Third Floor Stairs Old Homeopathic Hospital, 123 North Pearl St., Albany, N.Y. - Old Homeopathic Hospital (Interiors), 123 North Pearl Street, Albany, Albany County, NY

1. Historic American Buildings Survey, Nelson E. Baldwin, Photographer, Jan. ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

1. Historic American Buildings Survey, Nelson E. Baldwin, Photographer, Jan. 16, 1937, View - Stairway from First to Second Floor Old Homeopathic Hospital (Office of the HABS), Albany, N.Y. - Old Homeopathic Hospital (Interiors), 123 North Pearl Street, Albany, Albany County, NY

2. Historic American Buildings Survey, Nelson E. Baldwin, Photographer, Jan. ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

2. Historic American Buildings Survey, Nelson E. Baldwin, Photographer, Jan. 16, 1937, View - Interior Door Opening into Apartment on First Floor, 123 North Pearl St., Albany, N.Y. - Old Homeopathic Hospital (Interiors), 123 North Pearl Street, Albany, Albany County, NY

3. Historic American Buildings Survey, Nelson E. Baldwin, Photographer, Jan. ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

3. Historic American Buildings Survey, Nelson E. Baldwin, Photographer, Jan. 16, 1937, View - Double Doors and Columns in Apartment on First Floor, 123 North Pearl St., Albany, N.Y. - Old Homeopathic Hospital (Interiors), 123 North Pearl Street, Albany, Albany County, NY

Micropatterned stretchable circuit and strain sensor fabricated by lithography on an electrospun nanofiber mat.

PubMed

Park, Minwoo; Im, Jungkyun; Park, Jongjin; Jeong, Unyong

2013-09-11

This paper describes a novel approach for composite nanofiber mats and its application to fabricate a strain sensor. Electrospun poly(4-vinylpyridine) (P4VP) nanofiber mats are micropatterned by a lithographic approach that includes selective oxidation of the nanofibers and removal of unreacted fibers. The P4VP/HAuCl4 complex is converted to P4VP/Au composites by chemical reduction. We investigate the electrical resistivity of the composite mats according to the number of complexation-and-reduction cycles, the thickness of the fiber mats, and the annealing temperatures which control the percolation of the Au nanoparticles in the fiber mats. Nozzle printing of a polymeric solution on the patterned nanofiber mats simply produces an array of strain-sensitive and strain-invariant units. The patterns demonstrate high strain-sensing performance without any mechanical and electrical failure over 200 bending cycles in the strain range of ε<0.17.

Highly Maneuverable Aircraft Technology (HiMAT) flight-flutter test program

NASA Technical Reports Server (NTRS)

Kehoe, M. W.

1984-01-01

The highly maneuverable aircraft technology (HiMAT) vehicle was evaluated in a joint NASA and Air Force flight test program. The HiMAT vehicle is a remotely piloted research vehicle. Its design incorporates the use of advanced composite materials in the wings, and canards for aeroelastic tailoring. A flight-flutter test program was conducted to clear a sufficient flight envelope to allow for performance, stability and control, and loads testing. Testing was accomplished with and without flight control-surface dampers. Flutter clearance of the vehicle indicated satisfactory damping and damping trends for the structural modes of the HiMAT vehicle. The data presented include frequency and damping plotted as a function of Mach number.

Tracing biosignatures from the Recent to the Jurassic in sabkha-associated microbial mats

NASA Astrophysics Data System (ADS)

van der Land, Cees; Dutton, Kirsten; Andrade, Luiza; Paul, Andreas; Sherry, Angela; Fender, Tom; Hewett, Guy; Jones, Martin; Lokier, Stephen W.; Head, Ian M.

2017-04-01

Microbial mat ecosystems have been operating at the sediment-fluid interface for over 3400 million years, influencing the flux, transformation and preservation of carbon from the biosphere to the physical environment. These ecosystems are excellent recorders of rapid and profound changes in earth surface environments and biota as they often survive crisis-induced extreme paleoenvironmental conditions. Their biosignatures, captured in the preserved organic matter and the biominerals that form the microbialite rock, constitute a significant tool in understanding geobiological processes and the interactions of the microbial communities with sediments and with the prevailing physical chemical parameters, as well as the environmental conditions at a local and global scale. Nevertheless, the exact pathways of diagenetic organic matter transformation and early-lithification, essential for the accretion and preservation in the geological record as microbialites, are not well understood. The Abu Dhabi coastal sabkha system contains a vast microbial mat belt that is dominated by continuous polygonal and internally-laminated microbial mats across the upper and middle intertidal zones. This modern system is believed to be the best analogue for the Upper Jurassic Arab Formation, which is both a prolific hydrocarbon reservoir and source rock facies in the United Arab Emirates and in neighbouring countries. In order to characterise the processes that lead to the formation of microbialites we investigated the modern and Jurassic system using a multidisciplinary approach, including growth of field-sampled microbial mats under controlled conditions in the laboratory and field-based analysis of microbial communities, mat mineralogy and organic biomarker analysis. In this study, we focus on hydrocarbon biomarker data obtained from the surface of microbial mats actively growing in the intertidal zone of the modern system. By comparing these findings to data obtained from recently

HIDRA-MAT: A Material Analysis Tool for Fusion Devices

NASA Astrophysics Data System (ADS)

Andruczyk, Daniel; Rizkallah, Rabel; Bedoya, Felipe; Kapat, Aveek; Schamis, Hanna; Allain, Jean Paul

2017-10-01

The former WEGA stellarator which is now operating as HIDRA at the University of Illinois will be almost exclusively used to study the intimate relationship between the plasma interacting with surfaces of different materials. A Material Analysis Tool (HIDRA-MAT) is being designed and will be built based on the successful Material Analysis and Particle Probe (MAPP) which is currently used on NSTX-U at PPPL. This will be an in-situ material diagnostic probe, meaning that all analysis can be done without breaking vacuum. This allows surface changes to be studied in real-time. HIDRA-MAT will consist of several in-situ diagnostics including Langmuir probes (LP), Thermal Desorption Spectroscopy (TDS), X-ray Photo Spectroscopy (XPS) and Ion Scattering Spectroscopy (ISS). This presentation will outline the HIDRA-MAT diagnostic and initial design, as well as its integration into the HIDRA system.

Using Talking Mats to Support Communication in Persons with Huntington's Disease

ERIC Educational Resources Information Center

Ferm, Ulrika; Sahlin, Anna; Sundin, Linda; Hartelius, Lena

2010-01-01

Background: Many individuals with Huntington's disease experience reduced functioning in cognition, language and communication. Talking Mats is a visually based low technological augmentative communication framework that supports communication in people with different cognitive and communicative disabilities. Aims: To evaluate Talking Mats as a…

Motivating Teachers. The Best of ERIC on Educational Management, Number 60.

ERIC Educational Resources Information Center

ERIC Clearinghouse on Educational Management, Eugene, OR.

Two documents and ten journal articles on teacher motivation, selected from those recently made available through the ERIC system, are described in this report. Topics include the need for teacher incentive systems; the use of open-space schools in which several classes are taught simultaneously in one large room; the ways in which school boards…

Eric's Journey: A Restructured School's Inclusion Program and a Student with Disabilities.

ERIC Educational Resources Information Center

Richardson, Don H.

1998-01-01

Profiles a Milford, Connecticut, middle school's efforts to help Eric Kowalchick, a developmentally disabled adolescent, develop life skills and friendships, prepare for work, pursue school and community club memberships, and attend high school classes. The school's mainstreaming program is a success, thanks to an institutional mission understood…

Urinary Concentrations of Polycyclic Aromatic Hydrocarbon Metabolites in Maté Drinkers in Rio Grande do Sul, Brazil.

PubMed

Lopes, Antonio Barros; Metzdorf, Marcela; Metzdorf, Luiza; Sousa, Marcos Paulo Ramalho; Kavalco, Caroline; Etemadi, Arash; Pritchett, Natalie R; Murphy, Gwen; Calafat, Antonia M; Abnet, Christian C; Dawsey, Sanford M; Fagundes, Renato Borges

2018-03-01

Background: Consumption of maté , an infusion of the herb Ilex paraguariensis (yerba maté) , is associated with increased risk of esophageal squamous cell carcinoma (ESCC), but the carcinogenic mechanism is unclear. Commercial brands of yerba maté contain high levels of carcinogenic polycyclic aromatic hydrocarbons (PAHs), which are acquired during the traditional drying process. The purpose of this study was to characterize exposure to PAHs in maté drinkers over a wide range of maté consumption. Methods: We recruited 244 adults who answered a questionnaire and collected a fasting spot urine specimen. We quantified urinary concentrations of seven PAH metabolites and assessed associations between self-reported recent maté consumption and urinary PAH metabolites by multivariate regression. Results: Recent maté consumption showed a significant dose-response association with 6 of 7 PAH metabolites in unadjusted models ( P trend < 0.05). After adjustment for creatinine and potential confounders, concentrations of 2-naphthol, 1-hydroxyphenanthrene, and the sum of 2- and 3-hydroxyphenanthrene remained significantly associated with recent maté intake. The sum of the urinary concentrations of the phenanthrene metabolites was similar or higher among maté drinkers who did not smoke than among smokers who did not drink maté Conclusions: Urinary concentrations of PAH metabolites were significantly associated with self-reported amounts of recent maté intake, and drinking maté increased urinary concentrations of some PAH metabolites as much as smoking cigarettes. Impact: Drinking maté is a source of exposure to potentially carcinogenic PAHs, consistent with the hypothesis that the PAH content of maté may contribute to the increased risk of ESCC in maté drinkers. Cancer Epidemiol Biomarkers Prev; 27(3); 331-7. ©2017 AACR . ©2017 American Association for Cancer Research.

Deletion and Complementation of the Mating Type (MAT) Locus of the Wheat Head Blight Pathogen Gibberella zeae

PubMed Central

Desjardins, A. E.; Brown, D. W.; Yun, S.-H.; Proctor, R. H.; Lee, T.; Plattner, R. D.; Lu, S.-W.; Turgeon, B. G.

2004-01-01

Gibberella zeae, a self-fertile, haploid filamentous ascomycete, causes serious epidemics of wheat (Triticum aestivum) head blight worldwide and contaminates grain with trichothecene mycotoxins. Anecdotal evidence dating back to the late 19th century indicates that G. zeae ascospores (sexual spores) are a more important inoculum source than are macroconidia (asexual spores), although the fungus can produce both during wheat head blight epidemics. To develop fungal strains to test this hypothesis, the entire mating type (MAT1) locus was deleted from a self-fertile (MAT1-1/MAT1-2), virulent, trichothecene-producing wild-type strain of G. zeae. The resulting MAT deletion (mat1-1/mat1-2) strains were unable to produce perithecia or ascospores and appeared to be unable to mate with the fertile strain from which they were derived. Complementation of a MAT deletion strain by transformation with a copy of the entire MAT locus resulted in recovery of production of perithecia and ascospores. MAT deletion strains and MAT-complemented strains retained the ability to produce macroconidia that could cause head blight, as assessed by direct injection into wheat heads in greenhouse tests. Availability of MAT-null and MAT-complemented strains provides a means to determine the importance of ascospores in the biology of G. zeae and perhaps to identify novel approaches to control wheat head blight. PMID:15066842

rMATS: robust and flexible detection of differential alternative splicing from replicate RNA-Seq data.

PubMed

Shen, Shihao; Park, Juw Won; Lu, Zhi-xiang; Lin, Lan; Henry, Michael D; Wu, Ying Nian; Zhou, Qing; Xing, Yi

2014-12-23

Ultra-deep RNA sequencing (RNA-Seq) has become a powerful approach for genome-wide analysis of pre-mRNA alternative splicing. We previously developed multivariate analysis of transcript splicing (MATS), a statistical method for detecting differential alternative splicing between two RNA-Seq samples. Here we describe a new statistical model and computer program, replicate MATS (rMATS), designed for detection of differential alternative splicing from replicate RNA-Seq data. rMATS uses a hierarchical model to simultaneously account for sampling uncertainty in individual replicates and variability among replicates. In addition to the analysis of unpaired replicates, rMATS also includes a model specifically designed for paired replicates between sample groups. The hypothesis-testing framework of rMATS is flexible and can assess the statistical significance over any user-defined magnitude of splicing change. The performance of rMATS is evaluated by the analysis of simulated and real RNA-Seq data. rMATS outperformed two existing methods for replicate RNA-Seq data in all simulation settings, and RT-PCR yielded a high validation rate (94%) in an RNA-Seq dataset of prostate cancer cell lines. Our data also provide guiding principles for designing RNA-Seq studies of alternative splicing. We demonstrate that it is essential to incorporate biological replicates in the study design. Of note, pooling RNAs or merging RNA-Seq data from multiple replicates is not an effective approach to account for variability, and the result is particularly sensitive to outliers. The rMATS source code is freely available at rnaseq-mats.sourceforge.net/. As the popularity of RNA-Seq continues to grow, we expect rMATS will be useful for studies of alternative splicing in diverse RNA-Seq projects.

Metagenomic and metabolic profiling of nonlithifying and lithifying stromatolitic mats of Highborne Cay, The Bahamas.

PubMed

Khodadad, Christina L M; Foster, Jamie S

2012-01-01

Stromatolites are laminated carbonate build-ups formed by the metabolic activity of microbial mats and represent one of the oldest known ecosystems on Earth. In this study, we examined a living stromatolite located within the Exuma Sound, The Bahamas and profiled the metagenome and metabolic potential underlying these complex microbial communities. The metagenomes of the two dominant stromatolitic mat types, a nonlithifying (Type 1) and lithifying (Type 3) microbial mat, were partially sequenced and compared. This deep-sequencing approach was complemented by profiling the substrate utilization patterns of the mats using metabolic microarrays. Taxonomic assessment of the protein-encoding genes confirmed previous SSU rRNA analyses that bacteria dominate the metagenome of both mat types. Eukaryotes comprised less than 13% of the metagenomes and were rich in sequences associated with nematodes and heterotrophic protists. Comparative genomic analyses of the functional genes revealed extensive similarities in most of the subsystems between the nonlithifying and lithifying mat types. The one exception was an increase in the relative abundance of certain genes associated with carbohydrate metabolism in the lithifying Type 3 mats. Specifically, genes associated with the degradation of carbohydrates commonly found in exopolymeric substances, such as hexoses, deoxy- and acidic sugars were found. The genetic differences in carbohydrate metabolisms between the two mat types were confirmed using metabolic microarrays. Lithifying mats had a significant increase in diversity and utilization of carbon, nitrogen, phosphorus and sulfur substrates. The two stromatolitic mat types retained similar microbial communities, functional diversity and many genetic components within their metagenomes. However, there were major differences detected in the activity and genetic pathways of organic carbon utilization. These differences provide a strong link between the metagenome and the

Fermentation couples Chloroflexi and sulfate-reducing bacteria to Cyanobacteria in hypersaline microbial mats

PubMed Central

Lee, Jackson Z.; Burow, Luke C.; Woebken, Dagmar; Everroad, R. Craig; Kubo, Mike D.; Spormann, Alfred M.; Weber, Peter K.; Pett-Ridge, Jennifer; Bebout, Brad M.; Hoehler, Tori M.

2013-01-01

Past studies of hydrogen cycling in hypersaline microbial mats have shown an active nighttime cycle, with production largely from Cyanobacteria and consumption from sulfate-reducing bacteria (SRB). However, the mechanisms and magnitude of hydrogen cycling have not been extensively studied. Two mats types near Guerrero Negro, Mexico—permanently submerged Microcoleus microbial mat (GN-S), and intertidal Lyngbya microbial mat (GN-I)—were used in microcosm diel manipulation experiments with 3-(3,4-dichlorophenyl)-1,1-dimethylurea (DCMU), molybdate, ammonium addition, and physical disruption to understand the processes responsible for hydrogen cycling between mat microbes. Across microcosms, H2 production occurred under dark anoxic conditions with simultaneous production of a suite of organic acids. H2 production was not significantly affected by inhibition of nitrogen fixation, but rather appears to result from constitutive fermentation of photosynthetic storage products by oxygenic phototrophs. Comparison to accumulated glycogen and to CO2 flux indicated that, in the GN-I mat, fermentation released almost all of the carbon fixed via photosynthesis during the preceding day, primarily as organic acids. Across mats, although oxygenic and anoxygenic phototrophs were detected, cyanobacterial [NiFe]-hydrogenase transcripts predominated. Molybdate inhibition experiments indicated that SRBs from a wide distribution of DsrA phylotypes were responsible for H2 consumption. Incubation with 13C-acetate and NanoSIMS (secondary ion mass-spectrometry) indicated higher uptake in both Chloroflexi and SRBs relative to other filamentous bacteria. These manipulations and diel incubations confirm that Cyanobacteria were the main fermenters in Guerrero Negro mats and that the net flux of nighttime fermentation byproducts (not only hydrogen) was largely regulated by the interplay between Cyanobacteria, SRBs, and Chloroflexi. PMID:24616716

Fermentation couples Chloroflexi and sulfate-reducing bacteria to Cyanobacteria in hypersaline microbial mats

DOE PAGES

Lee, Jackson Z.; Burow, Luke C.; Woebken, Dagmar; ...

2014-01-01

Past studies of hydrogen cycling in hypersaline microbial mats have shown an active nighttime cycle, with production largely from Cyanobacteria and consumption from sulfate-reducing bacteria (SRB). However, the mechanisms and magnitude of hydrogen cycling have not been extensively studied. Two mats types near Guerrero Negro, Mexico$-$ permanently submerged Microcoleus microbial mat (GN-S), and intertidal Lyngbya microbial mat (GN-I)$-$were used in microcosm diel manipulation experiments with 3-(3,4-dichlorophenyl)-1,1-dimethylurea (DCMU), molybdate, ammonium addition, and physical disruption to understand the processes responsible for hydrogen cycling between mat microbes. Across microcosms, H 2 production occurred under dark anoxic conditions with simultaneous production of a suitemore » of organic acids. H 2 production was not significantly affected by inhibition of nitrogen fixation, but rather appears to result from constitutive fermentation of photosynthetic storage products by oxygenic phototrophs. Comparison to accumulated glycogen and to CO 2 flux indicated that, in the GN-I mat, fermentation released almost all of the carbon fixed via photosynthesis during the preceding day, primarily as organic acids. Across mats, although oxygenic and anoxygenic phototrophs were detected, cyanobacterial [NiFe]-hydrogenase transcripts predominated. Molybdate inhibition experiments indicated that SRBs from a wide distribution of DsrA phylotypes were responsible for H 2 consumption. Incubation with 13C-acetate and NanoSIMS (secondary ion mass-spectrometry) indicated higher uptake in both Chloroflexi and SRBs relative to other filamentous bacteria. These manipulations and diel incubations confirm that Cyanobacteria were the main fermenters in Guerrero Negro mats and that the net flux of nighttime fermentation byproducts (not only hydrogen) was largely regulated by the interplay between Cyanobacteria, SRBs, and Chloroflexi.« less

Remembering Joan (Jan) Mary Anderson (1932-2015).

PubMed

Chow, Wah Soon; Horton, Peter; Barrett, Martin; Osmond, Charles Barry

2016-08-01

Joan Mary Anderson, known to most people as Jan, was born on May 12, 1932 in Dunedin, New Zealand. She died on August 28, 2015 in Canberra, Australia. To celebrate her life, we present here a brief biography, some comments on her discoveries in photosynthesis during a career spanning more than half a century, and reminiscences from family and friends. We remember this wonderful person who had an unflagging curiosity, creative ability to think laterally, enthusiasm, passion, generosity and love of color and culture.

Hydroponic root mats for wastewater treatment-a review.

PubMed

Chen, Zhongbing; Cuervo, Diego Paredes; Müller, Jochen A; Wiessner, Arndt; Köser, Heinz; Vymazal, Jan; Kästner, Matthias; Kuschk, Peter

2016-08-01

Hydroponic root mats (HRMs) are ecotechnological wastewater treatment systems where aquatic vegetation forms buoyant filters by their dense interwoven roots and rhizomes, sometimes supported by rafts or other floating materials. A preferential hydraulic flow is created in the water zone between the plant root mat and the bottom of the treatment system. When the mat touches the bottom of the water body, such systems can also function as HRM filter; i.e. the hydraulic flow passes directly through the root zone. HRMs have been used for the treatment of various types of polluted water, including domestic wastewater; agricultural effluents; and polluted river, lake, stormwater and groundwater and even acid mine drainage. This article provides an overview on the concept of applying floating HRM and non-floating HRM filters for wastewater treatment. Exemplary performance data are presented, and the advantages and disadvantages of this technology are discussed in comparison to those of ponds, free-floating plant and soil-based constructed wetlands. Finally, suggestions are provided on the preferred scope of application of HRMs.

Teaching Foreign Policy in the Post-Cold War Era. ERIC Digest.

ERIC Educational Resources Information Center

Graseck, Susan

This ERIC Digest discusses issues relating to teaching about U.S. foreign policy in the changing international environment following the end of the Cold War era and the disintegration of the Soviet Union. The document treats: (1) the need and rationale for teaching and learning about current foreign policy issues; (2) main themes in foreign policy…

An Alternative to QUERY: Batch-Searching of the ERIC Information Collections.

ERIC Educational Resources Information Center

Krahmer, Edward; Horne, Kent

A manual describing the RIC computer search program for retrieval of information from ERIC, CIJE, and other collections is presented. It is pointed out that two versions of this program have been developed. The first is for an IBM 360/370 computer. This version has been operational on a production basis for nearly a year. Four installations of…

Community living long before man: fossil and living microbial mats and early life

NASA Technical Reports Server (NTRS)

Margulis, L.; Lopez Baluja, L.; Awramik, S. M.; Sagan, D.

1986-01-01

Microbial mats are layered communities of bacteria that form cohesive structures, some of which are preserved in sedimentary rocks as stromatolites. Certain rocks, approximately three and a half thousand million years old and representing the oldest known fossils, are interpreted to derive from microbial mats and to contain fossils of microorganisms. Modern microbial mats (such as the one described here from Matanzas, Cuba) and their fossil counterparts are of great interest in the interpretation of early life on Earth. Since examination of microbial mats and stromatolites increases our understanding of long-term stability and change, within the global environment, such structures should be protected wherever possible as natural science preserves. Furthermore, since they have existed virtually from the time of life's origin, microbial mats have developed exemplary mechanisms of local community persistence and may even play roles in the larger global environment that we do not understand.

A niche for cyanobacteria producing chlorophyll f within a microbial mat.

PubMed

Ohkubo, Satoshi; Miyashita, Hideaki

2017-10-01

Acquisition of additional photosynthetic pigments enables photosynthetic organisms to survive in particular niches. To reveal the ecological significance of chlorophyll (Chl) f, we investigated the distribution of Chl and cyanobacteria within two microbial mats. In a 7-mm-thick microbial mat beneath the running water of the Nakabusa hot spring, Japan, Chl f was only distributed 4.0-6.5 mm below the surface, where the intensity of far-red light (FR) was higher than that of photosynthetically active radiation (PAR). In the same mat, two ecotypes of Synechococcus and two ecotypes of Chl f-producing Leptolyngbya were detected in the upper and deeper layers, respectively. Only the Leptolyngbya strains could grow when FR was the sole light source. These results suggest that the deeper layer of the microbial mat was a habitat for Chl f-producing cyanobacteria, and Chl f enabled them to survive in a habitat with little PAR.

Integrated Surveillance for the Next Generation Air Transportation System. Final Report of the Integrated Surveillance Study Team

DTIC Science & Technology

2008-10-31

Navigation Services Working Group Jan de Regt FAA Tony Richardson JPDO Technical Support James Roberts DoD AFFSA Eric Rolfe JPDO Air Navigation...Kirsch DHS Drew Kuepper DoD eragency Architecture and Engineering Division Jay Merkle JPDO Int Paul Polski DHS ing GroupElizabeth Lynn ye JPDO Air

Sway Area and Velocity Correlated With MobileMat Balance Error Scoring System (BESS) Scores.

PubMed

Caccese, Jaclyn B; Buckley, Thomas A; Kaminski, Thomas W

2016-08-01

The Balance Error Scoring System (BESS) is often used for sport-related concussion balance assessment. However, moderate intratester and intertester reliability may cause low initial sensitivity, suggesting that a more objective balance assessment method is needed. The MobileMat BESS was designed for objective BESS scoring, but the outcome measures must be validated with reliable balance measures. Thus, the purpose of this investigation was to compare MobileMat BESS scores to linear and nonlinear measures of balance. Eighty-eight healthy collegiate student-athletes (age: 20.0 ± 1.4 y, height: 177.7 ± 10.7 cm, mass: 74.8 ± 13.7 kg) completed the MobileMat BESS. MobileMat BESS scores were compared with 95% area, sway velocity, approximate entropy, and sample entropy. MobileMat BESS scores were significantly correlated with 95% area for single-leg (r = .332) and tandem firm (r = .474), and double-leg foam (r = .660); and with sway velocity for single-leg (r = .406) and tandem firm (r = .601), and double-leg (r = .575) and single-leg foam (r = .434). MobileMat BESS scores were not correlated with approximate or sample entropy. MobileMat BESS scores were low to moderately correlated with linear measures, suggesting the ability to identify changes in the center of mass-center of pressure relationship, but not higher-order processing associated with nonlinear measures. These results suggest that the MobileMat BESS may be a clinically-useful tool that provides objective linear balance measures.

Complex polar lipids of a hot spring cyanobacterial mat and its cultivated inhabitants

NASA Technical Reports Server (NTRS)

Ward, D. M.; Panke, S.; Kloppel, K. D.; Christ, R.; Fredrickson, H.

1994-01-01

The complex polar lipids of the hot spring cyanobacterial mat in the 50 to 55 degrees C region of Octopus Spring, Yellowstone National Park, and of thermophilic bacteria cultivated from this or similar habitats, were compared in an attempt to understand the microbial sources of the major lipid biomarkers in this community. Intact complex lipids were analyzed directly by fast atom bombardment mass spectrometry (FAB-MS), two-dimensional thin-layer chromatography (TLC), and combined TLC-FAB-MS. FAB-MS and TLC gave qualitatively similar results, suggesting that the mat contains major lipids most like those of the cyanobacterial isolate we studied, Synechococcus sp. strain Y-7c-s. These include monoglycosyl, diglycosyl, and sulfoquinosovyl diglycerides (MG, DG, and SQ, respectively) and phosphatidyl glycerol (PG). Though Chloroflexus aurantiacus also contains MG, DG, and PG, the fatty acid chain lengths of mat MGs, DGs, and PGs resemble more those of cyanobacterial than green nonsulfur bacterial lipids. FAB-MS spectra of the lipids of nonphototrophic bacterial isolates were distinctively different from those of the mat and phototrophic isolates. The lipids of these nonphototrophic isolates were not detected in the mat, but most could be detected when added to mat samples. The mat also contains major glycolipids and aminophospholipids of unknown structure and origin. FAB-MS and TLC did not always give quantitatively similar results. In particular, PG and SQ may give disproportionately high FAB-MS responses.

Vertical Geochemical Profiling Across a 3.33 Ga Microbial Mat from Barberton

NASA Astrophysics Data System (ADS)

Westall, F.; Lemelle, L.; Simionovici, A.; Southam, G.; Maclean, L.; Salomé, M.; Wirick, S.; Toporski, J.; Jauss, A.

2008-03-01

The Josefdal Chert (3.33 Ga), Barberton, contains a superbly preserved microbial mat. High resolution geochemical profiling across the mat documents textures and compositions indicative of a mixed microbial community of anoxygenic photosynthesisers and probably SRBs.

Cantera Integration with the Toolbox for Modeling and Analysis of Thermodynamic Systems (T-MATS)

NASA Technical Reports Server (NTRS)

Lavelle, Thomas M.; Chapman, Jeffryes W.; May, Ryan D.; Litt, Jonathan S.; Guo, Ten-Huei

2014-01-01

NASA Glenn Research Center (GRC) has recently developed a software package for modeling generic thermodynamic systems called the Toolbox for the Modeling and Analysis of Thermodynamic Systems (T-MATS). T-MATS is a library of building blocks that can be assembled to represent any thermodynamic system in the Simulink(Registered TradeMark) (The MathWorks, Inc.) environment. These elements, along with a Newton Raphson solver (also provided as part of the T-MATS package), enable users to create models of a wide variety of systems. The current version of T-MATS (v1.0.1) uses tabular data for providing information about a specific mixture of air, water (humidity), and hydrocarbon fuel in calculations of thermodynamic properties. The capabilities of T-MATS can be expanded by integrating it with the Cantera thermodynamic package. Cantera is an object-oriented analysis package that calculates thermodynamic solutions for any mixture defined by the user. Integration of Cantera with T-MATS extends the range of systems that may be modeled using the toolbox. In addition, the library of elements released with Cantera were developed using MATLAB native M-files, allowing for quicker prototyping of elements. This paper discusses how the new Cantera-based elements are created and provides examples for using T-MATS integrated with Cantera.

Cantera Integration with the Toolbox for Modeling and Analysis of Thermodynamic Systems (T-MATS)

NASA Technical Reports Server (NTRS)

Lavelle, Thomas M.; Chapman, Jeffryes W.; May, Ryan D.; Litt, Jonathan S.; Guo, Ten-Huei

2014-01-01

NASA Glenn Research Center (GRC) has recently developed a software package for modeling generic thermodynamic systems called the Toolbox for the Modeling and Analysis of Thermodynamic Systems (T-MATS). T-MATS is a library of building blocks that can be assembled to represent any thermodynamic system in the Simulink (The MathWorks, Inc.) environment. These elements, along with a Newton Raphson solver (also provided as part of the T-MATS package), enable users to create models of a wide variety of systems. The current version of T-MATS (v1.0.1) uses tabular data for providing information about a specific mixture of air, water (humidity), and hydrocarbon fuel in calculations of thermodynamic properties. The capabilities of T-MATS can be expanded by integrating it with the Cantera thermodynamic package. Cantera is an object-oriented analysis package that calculates thermodynamic solutions for any mixture defined by the user. Integration of Cantera with T-MATS extends the range of systems that may be modeled using the toolbox. In addition, the library of elements released with Cantera were developed using MATLAB native M-files, allowing for quicker prototyping of elements. This paper discusses how the new Cantera-based elements are created and provides examples for using T-MATS integrated with Cantera.

Effects of tacky mat contamination on bond degradation for Chemlok/liner and NBR/liner bonds

NASA Technical Reports Server (NTRS)

Padilla, A. M.

1989-01-01

Tacky mats are placed by the rubber lay-up areas for the solid rocket motor segments. These mats dust off the shoes prior to entering the platform where the lay-up work is performed. The possibility exists that a tacky mat could be touched with gloved hands prior to handling the uncured nitride butadiene rubber (NBR). Tests were run to determine if NBR were accidentally touched would there be any degradation of the liner/NBR bond. The tacky mats were judged solely on the basis of bond degradation caused by either direct or indirect contamination. Test results all indicate that there was no notable NBR/Chemlok or liner/NBR bond degradation on samples that came into contact with the tacky mat material. Testing procedures are described. The tacky mat adhesive composition does not contain fluorocarbons or release agents that would affect bonding.

6. PHOTOCOPY FROM 'ILLUSTRATED CIRCULAR OF ROOTS'NEW IRON BLOWER,' Jan. ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

6. PHOTOCOPY FROM 'ILLUSTRATED CIRCULAR OF ROOTS'NEW IRON BLOWER,' Jan. 1880, p. 14, FROM FILES OF ROOTS-CONNERSVILLE BLOWER CO. CONNERSVILLE, IND. - P. H. & F. M. Roots Company, Eastern Avenue, Connersville, Fayette County, IN

Eric Davidson, his philosophy, and the history of science.

PubMed

Deichmann, Ute

2017-10-16

Eric Davidson, a passionate molecular developmental biologist and intellectual, believed that conceptual advances in the sciences should be based on knowledge of conceptual history. Convinced of the superiority of a causal-analytical approach over other methods, he succeeded in successfully applying this approach to the complex feature of organismal development by introducing the far-reaching concept of developmental Gene Regulatory Networks. This essay reviews Davidson's philosophy, his support for the history of science, and some aspects of his scientific personality.

matK-QR classifier: a patterns based approach for plant species identification.

PubMed

More, Ravi Prabhakar; Mane, Rupali Chandrashekhar; Purohit, Hemant J

2016-01-01

DNA barcoding is widely used and most efficient approach that facilitates rapid and accurate identification of plant species based on the short standardized segment of the genome. The nucleotide sequences of maturaseK ( matK ) and ribulose-1, 5-bisphosphate carboxylase ( rbcL ) marker loci are commonly used in plant species identification. Here, we present a new and highly efficient approach for identifying a unique set of discriminating nucleotide patterns to generate a signature (i.e. regular expression) for plant species identification. In order to generate molecular signatures, we used matK and rbcL loci datasets, which encompass 125 plant species in 52 genera reported by the CBOL plant working group. Initially, we performed Multiple Sequence Alignment (MSA) of all species followed by Position Specific Scoring Matrix (PSSM) for both loci to achieve a percentage of discrimination among species. Further, we detected Discriminating Patterns (DP) at genus and species level using PSSM for the matK dataset. Combining DP and consecutive pattern distances, we generated molecular signatures for each species. Finally, we performed a comparative assessment of these signatures with the existing methods including BLASTn, Support Vector Machines (SVM), Jrip-RIPPER, J48 (C4.5 algorithm), and the Naïve Bayes (NB) methods against NCBI-GenBank matK dataset. Due to the higher discrimination success obtained with the matK as compared to the rbcL , we selected matK gene for signature generation. We generated signatures for 60 species based on identified discriminating patterns at genus and species level. Our comparative assessment results suggest that a total of 46 out of 60 species could be correctly identified using generated signatures, followed by BLASTn (34 species), SVM (18 species), C4.5 (7 species), NB (4 species) and RIPPER (3 species) methods As a final outcome of this study, we converted signatures into QR codes and developed a software matK -QR Classifier (http

Community structure of free-floating filamentous cyanobacterial mats from the Wonder Lake geothermal springs in the Philippines.

PubMed

Lacap, Donnabella C; Smith, Gavin J D; Warren-Rhodes, Kimberley; Pointing, Stephen B

2005-07-01

Cyanobacterial mats were characterized from pools of 45-60 degrees C in near-neutral pH, low-sulphide geothermal springs in the Philippines. Mat structure did not vary with temperature. All mats possessed highly ordered layers of airspaces at both the macroscopic and microscopic level, and these appear to be an adaptation to a free-floating growth habit. Upper mat layers supported biomass with elevated carotenoid:chlorophyll a ratios and an as yet uncharacterized waxy layer on the dorsal surface. Microscopic examination revealed mats comprised a single Fischerella morphotype, with abundant heterocysts throughout mats at all temperatures. Molecular analysis of mat community structure only partly matched morphological identification. All samples supported greater 16S rDNA-defined diversity than morphology suggested, with a progressive loss in the number of genotypes with increasing temperature. Fischerella-like sequences were recovered from mats occurring at all temperatures, but some mats also yielded Oscillatoria-like sequences, although corresponding phenotypes were not observed. Phylogenetic analysis revealed that Fischerella-like sequences were most closely affiliated with Fischerella major and the Oscillatoria-like sequences with Oscillatoria amphigranulata.

Jan Swammerdam's frogs

PubMed Central

Sleigh, Charlotte

2012-01-01

Having discussed insect metamorphosis at length, Jan Swammerdam's Bybel der Natuure (1679/1737) reached its climax with a substantial description of the generation and muscular activity of frogs. This paper explores the rhetorical role of frogs in Swammerdam's ‘great work’, showing how they were the Archimedean point from which he aimed to reorder all of creation—from insects to humans—within one glorious, God-ordained natural history and philosophy. Swammerdam linked insects to frogs through a demonstration that all underwent epigenesis; and frogs were then linked to humans through a demonstration of their identical muscular activity. The success of Swammerdam's strategy required a theological reconstruction of the frog, traditionally an ungodly creature, such that trustworthy knowledge could be obtained from its body. Perhaps surprisingly, this act of theological cleansing is shown to be somewhat prefigured in the distinctly non-experimental natural history of Edward Topsell (1608). The paper also examines Swammerdam's interactions with the mystic Antoinette Bourignon, and his challenges in reconciling a spirituality of meletetics with a material epistemology in natural philosophy. Differences are revealed between the natural analogies given by Swammerdam in his published and unpublished writings, undermining to a certain extent the triumphal insect–frog–human rhetorical structure of the Bybel.

Close association of active nitrifiers with Beggiatoa mats covering deep-sea hydrothermal sediments.

PubMed

Winkel, Matthias; de Beer, Dirk; Lavik, Gaute; Peplies, Jörg; Mußmann, Marc

2014-06-01

Hydrothermal sediments in the Guaymas Basin are covered by microbial mats that are dominated by nitrate-respiring and sulphide-oxidizing Beggiatoa. The presence of these mats strongly correlates with sulphide- and ammonium-rich fluids venting from the subsurface. Because ammonium and oxygen form opposed gradients at the sediment surface, we hypothesized that nitrification is an active process in these Beggiatoa mats. Using biogeochemical and molecular methods, we measured nitrification and determined the diversity and abundance of nitrifiers. Nitrification rates ranged from 74 to 605 μmol N l(-1)  mat day(-1), which exceeded those previously measured in hydrothermal plumes and other deep-sea habitats. Diversity and abundance analyses of archaeal and bacterial ammonia monooxygenase subunit A genes, archaeal 16S ribosomal RNA pyrotags and fluorescence in situ hybridization confirmed that ammonia- and nitrite-oxidizing microorganisms were associated with Beggiatoa mats. Intriguingly, we observed cells of bacterial and potential thaumarchaeotal ammonia oxidizers attached to narrow, Beggiatoa-like filaments. Such a close spatial coupling of nitrification and nitrate respiration in mats of large sulphur bacteria is novel and may facilitate mat-internal cycling of nitrogen, thereby reducing loss of bioavailable nitrogen in deep-sea sediments. © 2013 Society for Applied Microbiology and John Wiley & Sons Ltd.

Eric Freed Named Deputy Director of HIV Drug Resistance Program | Poster

Cancer.gov

Editor’s note: The text for this article was adapted from an e-mail announcement to the Center for Cancer Research community from Robert Wiltrout, Ph.D., on September 8, 2014. Robert Wiltrout, Ph.D., director, NCI Center for Cancer Research (CCR), recently announced the appointment of Eric Freed, Ph.D., as deputy director of the HIV Drug Resistance Program (HIV DRP). Freed

High Areal Capacity Si/LiCoO 2 Batteries from Electrospun Composite Fiber Mats

DOE Office of Scientific and Technical Information (OSTI.GOV)

Self, Ethan C.; Naguib, Michael; Ruther, Rose E.

Here, freestanding nanofiber mat Li-ion battery anodes containing Si nanoparticles, carbon black, and poly(acrylic acid) (Si/C/PAA) are prepared using electrospinning. The mats are compacted to a high fiber volume fraction (~0.85), and interfiber contacts are welded by exposing the mat to methanol vapor. A compacted+welded fiber mat anode containing 40 wt % Si exhibits high capacities of 1,484 mA h g -1 (3,500 mA h gmore » $$-1\\atop{Si}$$) at 0.1 C and 489 mAh g -1 at 1 C and good cycling stability (e.g., 73% capacity retention over 50 cycles). Post-mortem analysis of the fiber mats shows that the overall electrode structure is preserved during cycling. Whereas many nanostructured Si anodes are hindered by their low active material loadings and densities, thick, densely packed Si/C/PAA fiber mat anodes reported here have high areal and volumetric capacities (e.g., 4.5 mA h cm -2 and 750 mA h cm -3, respectively). A full cell containing an electrospun Si/C/PAA anode and electrospun LiCoO 2-based cathode has a high specific energy density of 270 Wh kg -1. The excellent performance of the electrospun Si/C/PAA fiber mat anodes is attributed to the: (i) PAA binder which interacts with the SiO x surface of Si nanoparticles and (ii) high material loading, high fiber volume fraction, and welded interfiber contacts of the electrospun mats« less

High Areal Capacity Si/LiCoO 2 Batteries from Electrospun Composite Fiber Mats

DOE PAGES

Self, Ethan C.; Naguib, Michael; Ruther, Rose E.; ...

2017-03-24

Here, freestanding nanofiber mat Li-ion battery anodes containing Si nanoparticles, carbon black, and poly(acrylic acid) (Si/C/PAA) are prepared using electrospinning. The mats are compacted to a high fiber volume fraction (~0.85), and interfiber contacts are welded by exposing the mat to methanol vapor. A compacted+welded fiber mat anode containing 40 wt % Si exhibits high capacities of 1,484 mA h g -1 (3,500 mA h gmore » $$-1\\atop{Si}$$) at 0.1 C and 489 mAh g -1 at 1 C and good cycling stability (e.g., 73% capacity retention over 50 cycles). Post-mortem analysis of the fiber mats shows that the overall electrode structure is preserved during cycling. Whereas many nanostructured Si anodes are hindered by their low active material loadings and densities, thick, densely packed Si/C/PAA fiber mat anodes reported here have high areal and volumetric capacities (e.g., 4.5 mA h cm -2 and 750 mA h cm -3, respectively). A full cell containing an electrospun Si/C/PAA anode and electrospun LiCoO 2-based cathode has a high specific energy density of 270 Wh kg -1. The excellent performance of the electrospun Si/C/PAA fiber mat anodes is attributed to the: (i) PAA binder which interacts with the SiO x surface of Si nanoparticles and (ii) high material loading, high fiber volume fraction, and welded interfiber contacts of the electrospun mats« less

75 FR 55360 - In the Matter of Mattingly Testing Services, Inc. Molt, MT; Order Revoking License (Effective...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-09-10

... radiation safety officer, and due to expire on February 28, 2016. The license authorizes Mattingly to... effectiveness of Mattingly's radiation safety and compliance programs by commencing an assessment of Mattingly's radiation safety program within 30 days of NRC's approval of the consultant; by reviewing Mattingly's...

Concept Mapping: A Graphical System for Understanding the Relationship between Concepts. ERIC Digest.

ERIC Educational Resources Information Center

Plotnick, Eric

This ERIC Digest discusses concept mapping, a technique for representing the structure of information visually. Concept mapping can be used to brainstorm, design complex structures, communicate complex ideas, aid learning by explicitly integrating new and old knowledge, and assess understanding or diagnose misunderstanding. Visual representation…

Teaching Democracy in East Central Europe: The Case of Poland. ERIC Digest.

ERIC Educational Resources Information Center

Remy, Richard C.

This ERIC digest discusses the Education for Democratic Citizenship in Poland (EDCP) project, a cooperative effort of the Polish Ministry of National Education, the Mershon Center at The Ohio State University, and the Bureau for Civic Education in Local Control Schools at Warsaw, Poland. The digest discusses the background of the project, the…

Cumulative Index of ERIC Resources in Counseling and Personnel Services. 1967-1976.

ERIC Educational Resources Information Center

Walz, Garry R.; And Others

This cumulative index contains over 5500 titles from the ERIC collection, and represents all the document input from the Clearinghouse on Counseling and Personnel Services between 1967-1976. Topics cover theoretical and practical information in all areas of counseling and guidance as well as in drug abuse, aging, sexuality and death. Directions…

Fact Sheets from the ERIC Clearinghouse on Handicapped and Gifted Children, 1980.

ERIC Educational Resources Information Center

ERIC Clearinghouse on Handicapped and Gifted Children, Reston, VA.

The document is a compilation of 15 fact sheets developed during 1980 by the ERIC Clearinghouse on Handicapped and Gifted Children. Fact sheets are single sheets which provide basic information in a question-answer format and include additional resources and references. The fact sheets have the following titles: "Sex Education for Retarded…

Microbial Species Richness and Metabolic Activities in Hypersaline Microbial Mats: Insight into Biosignature Formation Through Lithification

NASA Astrophysics Data System (ADS)

Baumgartner, Laura K.; Dupraz, Christophe; Buckley, Daniel H.; Spear, John R.; Pace, Norman R.; Visscher, Pieter T.

2009-11-01

Microbial mats in the hypersaline lake of Salt Pan, Eleuthera, Bahamas, display a gradient of lithification along a transect from the center to the shore of the lake. These mats exist under similar geochemical conditions, with light quantity and quality as the sole major environmental difference. Therefore, we hypothesized that the microbial community may be driving the differences in lithification and, by extension, mineral biosignature formation. The lithifying and non-lithifying mat communities were compared (via 16S rRNA gene sequencing, 485 and 464 sequences, respectively) over both temporal and spatial scales. Seven bacterial groups dominated in all the microbial mat libraries: bacteriodetes, alphaproteobacteria, deltaproetobacteria, chloroflexi, spirochaetes, cyanobacteria, and planctomycetes. The mat communities were all significantly different over space, time, and lithification state. Species richness is significantly higher in the non-lithifying mats, potentially due to differences in mat structure and activity. This increased richness may impact lithification and, hence, biosignature production.

Methylmercury enters an aquatic food web through acidophilic microbial mats in Yellowstone National Park, Wyoming.

PubMed

Boyd, Eric S; King, Susan; Tomberlin, Jeffery K; Nordstrom, D Kirk; Krabbenhoft, David P; Barkay, Tamar; Geesey, Gill G

2009-04-01

Microbial mats are a visible and abundant life form inhabiting the extreme environments in Yellowstone National Park (YNP), WY, USA. Little is known of their role in food webs that exist in the Park's geothermal habitats. Eukaryotic green algae associated with a phototrophic green/purple Zygogonium microbial mat community that inhabits low-temperature regions of acidic (pH approximately 3.0) thermal springs were found to serve as a food source for stratiomyid (Diptera: Stratiomyidae) larvae. Mercury in spring source water was taken up and concentrated by the mat biomass. Monomethylmercury compounds (MeHg(+)), while undetectable or near the detection limit (0.025 ng l(-1)) in the source water of the springs, was present at concentrations of 4-7 ng g(-1) dry weight of mat biomass. Detection of MeHg(+) in tracheal tissue of larvae grazing the mat suggests that MeHg(+) enters this geothermal food web through the phototrophic microbial mat community. The concentration of MeHg(+) was two to five times higher in larval tissue than mat biomass indicating MeHg(+) biomagnification occurred between primary producer and primary consumer trophic levels. The Zygogonium mat community and stratiomyid larvae may also play a role in the transfer of MeHg(+) to species in the food web whose range extends beyond a particular geothermal feature of YNP.

Increasing Mechanical Properties of 2-D-Structured Electrospun Nylon 6 Non-Woven Fiber Mats.

PubMed

Xiang, Chunhui; Frey, Margaret W

2016-04-07

Tensile strength, Young's modulus, and toughness of electrospun nylon 6 non-woven fiber mats were improved by increasing individual nanofiber strength and fiber-fiber load sharing. Single-walled carbon nanotubes (CNTs) were used as reinforcement to increase the strength of the electrospun nylon 6 nanofibers. Young's modulus, tensile strength, and toughness of the nylon 6 non-woven fiber mats electrospun from 20 wt % solutions increased 51%, 87%, and 136%, respectively, after incorporating 1 wt % CNTs into the nylon 6 nanofibers. Three methods were investigated to enhance fiber-fiber load sharing: increasing friction between fibers, thermal bonding, and solvent bonding. The addition of beaded nylon 6 nanofibers into the non-woven fiber mats to increase fiber-fiber friction resulted in a statistically significantly increase in Young's modulus over comparable smooth non-woven fiber mats. After annealing, tensile strength, elongation, and toughness of the nylon 6 non-woven fiber mats electrospun from 20 wt % + 10 wt % solutions increased 26%, 28%, and 68% compared to those from 20 wt % solutions. Solvent bonding with formic acid vapor at room temperature for 30 min caused increases of 56%, 67%, and 39% in the Young's modulus, tensile strength, and toughness of non-woven fiber mats, respectively. The increases attributed to increased individual nanofiber strength and solvent bonding synergistically resulted in the improvement of Young's modulus of the electrospun nylon 6 non-woven fiber mats.

Microbial communities inhabiting hypersaline microbial mats from the Abu Dhabi sabkha

NASA Astrophysics Data System (ADS)

Andrade, Luiza; Dutton, Kirsten; Paul, Andreas; van der Land, Cees; Sherry, Angela; Lokier, Stephen; Head, Ian

2017-04-01

Microbial mats are organo-sedimentary structures that are typically found in areas with extreme environmental conditions. Since these ecosystems are considered to be representative of the oldest forms of life on Earth, the study of microbial mats can inform our understanding of the development of life early in the history of our planet. In this study, we used hypersaline microbial mats from the Abu Dhabi sabkha (coastal salt flats). Cores of microbial mats (ca. 90 mm depth) were collected within an intertidal region. The cores were sliced into layers 2-3 mm thick and genomic DNA was extracted from each layer. A fragment of the 16S rRNA encoding gene was amplified in all DNA extracts, using barcoded primers, and the amplicons sequenced with the Ion Torrent platform to investigate the composition of the microbial communities down the depth of the cores. Preliminary results revealed a high proportion of Archaea (15.5-40.8% abundance) in all layers, with Halobacteria appearing to be more significant in the first 40 mm (0.4-10.3% of the total microbial community). Members of the Deltaproteobacteria were dominant in almost all layers of the microbial mat (≤ 48.6% relative abundance); however this dominance was not reflected in the first 8 mm, where the abundance was less than 2%. Chloroflexi and Anaerolinea, representing 93% of bacterial abundance, dominated the first 8 mm depth and decreased at greater depth (≤ 3% relative abundance). Cyanobacteria were found only in the top 10 mm, with unexpected low abundance (≤ 3% of the total number of reads). These results show a vertical zonation of microbial communities and processes in the microbial mats. Further analyses are underway to investigate if these patterns are repeated at other sites along a transect of the sabkha, and to relate the microbial composition to the physical-chemical conditions of the sites.

The micromorphology of Younger Dryas-aged black mats from Nevada, Arizona, Texas and New Mexico

NASA Astrophysics Data System (ADS)

Harris-Parks, Erin

2016-01-01

Black mats are organic-rich sediments and soils that form in wet environments associated with spring discharge. Micromorphological and geochemical analyses of 25 black mats dating to the Younger Dryas Chronozone (12.9-11.7 ka) and early Holocene were conducted to determine their composition and depositional environment. Samples were collected from Arizona, New Mexico, Texas and Nevada. Micromorphological analyses were conducted on thin sections using polarized and blue fluorescent light. These analyses determined that black mats contain humic acids, fine (5-20 μm) plant fragments, diatoms, phytoliths, and gastropods. The dominant type of organic matter in black mats is derived from herbaceous plants, contradicting previous studies that supported algal or charcoal sources. Differences in the micromorphological characteristics of the samples revealed that black mats formed as three different types, organic horizons, moist soils and, ponded sediments, depending on their topographic position in relation to the water table. The microscopic evidence found in black mats supports the presence of widespread wet environments in Nevada and Arizona during the Younger Dryas Chronozone, clearly indicating a sustained period of greater effective moisture, optimal for spring discharge and black mat formation.

Iron microbial mats in modern and phanerozoic environments

NASA Astrophysics Data System (ADS)

Baele, Jean-Marc; Bouvain, Frédéric; De Jong, Jeroen; Matielli, Nadine; Papier, Séverine; Préat, Alain

2008-08-01

The recognition of iron microbial mats in terrestrial environments is of great relevance for the search for extraterrestrial life, especially on mars where significant iron minerals were identified in the subsurface. Most researches focused on very ancient microbial mats (e.g. BIFs) since they formed on Earth at a time where similar conditions are supposed to have prevailed on Mars too. However, environmental proxies are often difficult to use for these deposits on Earth which, in addition, may be heavily transformed due to diagenesis or even metamorphism. Here we present modern and phanerozoic iron microbial mats occurrences illustrating the wide variety of environments in which they form, including many marine settings, ponds, creeks, caves, volcanoes, etc. Contrarily to their Precambrian counterparts, Modern and Phanerozoic deposits are usually less affected by diagenesis and the environmental conditions likely to be better constrained. Therefore, their investigation may help for the search for morphological and geochemical biosignatures (e.g. iron isotopes) in ancient iron microbial occurrences on Earth but also on other Planets. In particular, many of the case studies presented here show that microstromatolithe-like morphologies may be valuable targets for screening potential biosignatures in various rock types.

Flow visualization study of the HiMAT RPRV

NASA Technical Reports Server (NTRS)

Lorincz, D. J.

1980-01-01

Water tunnel studies were performed to qualitatively define the flow field of the highly maneuverable aircraft technology remotely piloted research vehicle (HiMAT RPRV). Particular emphasis was placed on defining the vortex flows generated at high angles of attack. The flow visualization tests were conducted in the Northrop water tunnel using a 1/15 scale model of the HiMAT RPRV. Flow visualization photographs were obtained for angles of attack up to 40 deg and sideslip angles up to 5 deg. The HiMAT model was investigated in detail to determine the canard and wing vortex flow field development, vortex paths, and vortex breakdown characteristics as a function of angle of attack and sideslip. The presence of the canard caused the wing vortex to form further outboard and delayed the breakdown of the wing vortex to higher angles of attack. An increase in leading edge camber of the maneuver configuration delayed both the formation and the breakdown of the wing and canard vortices. Additional tests showed that the canard vortex was sensitive to variations in inlet mass flow ratio and canard flap deflection angle.

A precision multi-sampler for deep-sea hydrothermal microbial mat studies

NASA Astrophysics Data System (ADS)

Breier, J. A.; Gomez-Ibanez, D.; Reddington, E.; Huber, J. A.; Emerson, D.

2012-12-01

A new tool was developed for deep-sea microbial mat studies by remotely operated vehicles and was successfully deployed during a cruise to the hydrothermal vent systems of the Mid-Cayman Rise. The Mat Sampler allows for discrete, controlled material collection from complex microbial structures, vertical-profiling within thick microbial mats and particulate and fluid sample collection from venting seafloor fluids. It has a reconfigurable and expandable sample capacity based on magazines of 6 syringes, filters, or water bottles. Multiple magazines can be used such that 12-36 samples can be collected routinely during a single dive; several times more if the dive is dedicated for this purpose. It is capable of hosting in situ physical, electrochemical, and optical sensors, including temperature and oxygen probes in order to guide sampling and to record critical environmental parameters at the time and point of sample collection. The precision sampling capability of this instrument will greatly enhance efforts to understand the structured, delicate, microbial mat communities that grow in diverse benthic habitats.

Enhancement of the in-plane shear properties of carbon fiber composites containing carbon nanotube mats

NASA Astrophysics Data System (ADS)

Kim, Hansang

2015-01-01

The in-plane shear property of carbon fiber laminates is one of the most important structural features of aerospace and marine structures. Fiber-matrix debonding caused by in-plane shear loading is the major failure mode of carbon fiber composites because of the stress concentration at the interfaces. In this study, carbon nanotube mats (CNT mat) were incorporated in two different types of carbon fiber composites. For the case of woven fabric composites, mechanical interlocking between the CNTs and the carbon fibers increased resistance to shear failure. However, not much improvement was observed for the prepreg composites as a result of incorporation of the CNT mats. The reinforcement mechanism of the CNT mat layer was investigated by a fractographic study using scanning electron microscopy. In addition, the CNT mat was functionalized by three different methods and the effectiveness of the functionalization methods was determined and the most appropriate functionalization method for the CNT mat was air oxidation.

Q & A with Ed Tech Leaders: Interview with Jan Herrington

ERIC Educational Resources Information Center

Fulgham, Susan M.; Shaughnessy, Michael F.

2014-01-01

Jan Herrington is a Professor of Education at Murdoch University in Perth, Western Australia, where she teaches educational technology in the School of Education, including a compulsory first year unit called "Living and Learning with Technology." She has been active in the promotion and support of the effective use of educational…

Coping with Stress. The Best of ERIC on Educational Management, Number 50.

ERIC Educational Resources Information Center

ERIC Clearinghouse on Educational Management, Eugene, OR.

The twelve items in this annotated bibliography are entries in the ERIC system intended to help administrators in coping with stress. The publications cited deal with causes of stress, how to manage stress, how to make life style changes, how to recognize stressors, and work patterns associated with Type A behavior. The publications listed also…

The type of mat (Contact vs. Photocell) affects vertical jump height estimated from flight time.

PubMed

García-López, Juan; Morante, Juan C; Ogueta-Alday, Ana; Rodríguez-Marroyo, Jose A

2013-04-01

The purposes of this study were to analyze the validity and reliability of 2 photocell mats and to probe the possible influence of the type of mat (contact vs. photocell) on vertical jump height estimated from flight time. In 2 separate studies, 89 and 92 physical students performed 3 countermovement jumps that were simultaneously registered by a Force Plate (gold standard method), 2 photocell mats (SportJump System Pro and ErgoJump Plus), and a contact mat (SportJump-v1.0). The first study showed that the 2 photocell mats underestimated the vertical jump height (1.3 ± 0.2 cm and 5.9 ± 5.2 cm, respectively), but only SportJump System Pro showed a high correlation with the Force Plate (r = 0.999 and 0.676, respectively) and good intraday reliability (coefficient of variation = 2.98 and 15.94%, intraclass correlation coefficients = 0.95-0.97 and 0.45-0.57, respectively). The second study demonstrated a strong correlation (r = 0.994) between the 2 technologies (contact vs. photocell mats) with differences in vertical jump height of 2.0 ± 0.8 cm (95% confidence interval = 1.9-2.1 cm), which depended on both flight time and subjects' body mass. In conclusion, SportJump System Pro was a valid and reliable device. The new devices to measure vertical jump height from flight time should be validated. The type of mat (contact vs. photocell) affected approximately 6% the vertical jump height (approximately 2 cm in this study), which should be considered in further studies. The use of validated photocell mats instead of the contact mats was recommended.

Diversity and physiology of polyhydroxyalkanoate-producing and -degrading strains in microbial mats.

PubMed

Villanueva, Laura; Del Campo, Javier; Guerrero, Ricardo

2010-10-01

Photosynthetic microbial mats are sources of microbial diversity and physiological strategies that reflect the physical and metabolic interactions between their resident species. This study focused on the diversity and activity of polyhydroxyalkanoate-producing and -degrading bacteria and their close partnership with cyanobacteria in an estuarine and a hypersaline microbial mat. The aerobic heterotrophic population was characterized on the basis of lipid biomarkers (respiratory quinones, sphingoid bases), polyhydroxyalkanoate determination, biochemical analysis of the isolates, and interaction assays. Most of the polyhydroxyalkanoate-producing isolates obtained from an estuarine mat belonged to the Halomonas and Labrenzia genera, while species of Sphingomonas and Bacillus were more prevalent in the hypersaline mat. Besides, the characterization of heterotrophic bacteria coisolated with filamentous cyanobacteria after selection suggested a specific association between them and diversification of the heterotrophic partner belonging to the Halomonas genus. Preliminary experiments suggested that syntrophic associations between strains of the Pseudoalteromonas and Halomonas genera explain the dynamics of polyhydroxyalkanoate accumulation in some microbial mats. These metabolic interactions and the diversity of the bacteria that participate in them are most likely supported by the strong mutual dependence of the partners. © 2010 Federation of European Microbiological Societies. Published by Blackwell Publishing Ltd. All rights reserved.

Preface - BraMat 2017

NASA Astrophysics Data System (ADS)

Munteanu, Daniel

2018-04-01

The main goal of the BraMat 2017 Conference was, as for the previous editions, to stimulate an international exchange of information in the field of materials science and engineering and to establish future research directions. The main topics of this edition included: ​Metallic materials (Section I), Biomaterials (Section II), Ceramics, polymers and composite materials (Section III), Surface engineering (Section IV), Nanomaterials (Section V), Welding engineering (Section VI), Safety engineering (Section VII), and Magnesium science and engineering (Section VIII).

Methylmercury enters an aquatic food web through acidophilic microbial mats in Yellowstone National Park, Wyoming

USGS Publications Warehouse

Boyd, E.S.; King, S.; Tomberlin, J.K.; Nordstrom, D. Kirk; Krabbenhoft, D.P.; Barkay, T.; Geesey, G.G.

2009-01-01

Summary Microbial mats are a visible and abundant life form inhabiting the extreme environments in Yellowstone National Park (YNP), WY, USA. Little is known of their role in food webs that exist in the Park's geothermal habitats. Eukaryotic green algae associated with a phototrophic green/purple Zygogonium microbial mat community that inhabits low-temperature regions of acidic (pH ??? 3.0) thermal springs were found to serve as a food source for stratiomyid (Diptera: Stratiomyidae) larvae. Mercury in spring source water was taken up and concentrated by the mat biomass. Monomethylmercury compounds (MeHg +), while undetectable or near the detection limit (0.025 ng l -1) in the source water of the springs, was present at concentrations of 4-7 ng g-1 dry weight of mat biomass. Detection of MeHg + in tracheal tissue of larvae grazing the mat suggests that MeHg+ enters this geothermal food web through the phototrophic microbial mat community. The concentration of MeHg+ was two to five times higher in larval tissue than mat biomass indicating MeHg+ biomagnification occurred between primary producer and primary consumer trophic levels. The Zygogonium mat community and stratiomyid larvae may also play a role in the transfer of MeHg+ to species in the food web whose range extends beyond a particular geothermal feature of YNP. ?? 2008 The Authors. Journal compilation ?? 2008 Society for Applied Microbiology and Blackwell Publishing Ltd.

Localized electron transfer rates and microelectrode-based enrichment of microbial communities within a phototrophic microbial mat.

PubMed

Babauta, Jerome T; Atci, Erhan; Ha, Phuc T; Lindemann, Stephen R; Ewing, Timothy; Call, Douglas R; Fredrickson, James K; Beyenal, Haluk

2014-01-01

Phototrophic microbial mats frequently exhibit sharp, light-dependent redox gradients that regulate microbial respiration on specific electron acceptors as a function of depth. In this work, a benthic phototrophic microbial mat from Hot Lake, a hypersaline, epsomitic lake located near Oroville in north-central Washington, was used to develop a microscale electrochemical method to study local electron transfer processes within the mat. To characterize the physicochemical variables influencing electron transfer, we initially quantified redox potential, pH, and dissolved oxygen gradients by depth in the mat under photic and aphotic conditions. We further demonstrated that power output of a mat fuel cell was light-dependent. To study local electron transfer processes, we deployed a microscale electrode (microelectrode) with tip size ~20 μm. To enrich a subset of microorganisms capable of interacting with the microelectrode, we anodically polarized the microelectrode at depth in the mat. Subsequently, to characterize the microelectrode-associated community and compare it to the neighboring mat community, we performed amplicon sequencing of the V1-V3 region of the 16S gene. Differences in Bray-Curtis beta diversity, illustrated by large changes in relative abundance at the phylum level, suggested successful enrichment of specific mat community members on the microelectrode surface. The microelectrode-associated community exhibited substantially reduced alpha diversity and elevated relative abundances of Prosthecochloris, Loktanella, Catellibacterium, other unclassified members of Rhodobacteraceae, Thiomicrospira, and Limnobacter, compared with the community at an equivalent depth in the mat. Our results suggest that local electron transfer to an anodically polarized microelectrode selected for a specific microbial population, with substantially more abundance and diversity of sulfur-oxidizing phylotypes compared with the neighboring mat community.

Localized electron transfer rates and microelectrode-based enrichment of microbial communities within a phototrophic microbial mat

PubMed Central

Babauta, Jerome T.; Atci, Erhan; Ha, Phuc T.; Lindemann, Stephen R.; Ewing, Timothy; Call, Douglas R.; Fredrickson, James K.; Beyenal, Haluk

2014-01-01

Phototrophic microbial mats frequently exhibit sharp, light-dependent redox gradients that regulate microbial respiration on specific electron acceptors as a function of depth. In this work, a benthic phototrophic microbial mat from Hot Lake, a hypersaline, epsomitic lake located near Oroville in north-central Washington, was used to develop a microscale electrochemical method to study local electron transfer processes within the mat. To characterize the physicochemical variables influencing electron transfer, we initially quantified redox potential, pH, and dissolved oxygen gradients by depth in the mat under photic and aphotic conditions. We further demonstrated that power output of a mat fuel cell was light-dependent. To study local electron transfer processes, we deployed a microscale electrode (microelectrode) with tip size ~20 μm. To enrich a subset of microorganisms capable of interacting with the microelectrode, we anodically polarized the microelectrode at depth in the mat. Subsequently, to characterize the microelectrode-associated community and compare it to the neighboring mat community, we performed amplicon sequencing of the V1–V3 region of the 16S gene. Differences in Bray-Curtis beta diversity, illustrated by large changes in relative abundance at the phylum level, suggested successful enrichment of specific mat community members on the microelectrode surface. The microelectrode-associated community exhibited substantially reduced alpha diversity and elevated relative abundances of Prosthecochloris, Loktanella, Catellibacterium, other unclassified members of Rhodobacteraceae, Thiomicrospira, and Limnobacter, compared with the community at an equivalent depth in the mat. Our results suggest that local electron transfer to an anodically polarized microelectrode selected for a specific microbial population, with substantially more abundance and diversity of sulfur-oxidizing phylotypes compared with the neighboring mat community. PMID:24478768

Black Mats, Spring-Fed Streams, and Late-Glacial-Age Recharge in the Southern Great Basin

USGS Publications Warehouse

Quade, Jay; Forester, R.M.; Pratt, W.L.; Carter, C.

1998-01-01

Black mats are prominent features of the late Pleistocene and Holocene stratigraphic record in the southern Great Basin. Faunal, geochemical, and sedimentological evidence shows that the black mats formed in several microenvironments related to spring discharge, ranging from wet meadows to shallow ponds. Small land snails such as Gastrocopta tappaniana and Vertigo berryi are the most common mollusk taxa present. Semiaquatic and aquatic taxa are less abundant and include Catinellids, Fossaria parva, Gyraulus parvus, and others living today in and around perennial seeps and ponds. The ostracodes Cypridopsis okeechobi and Scottia tumida, typical of seeps and low-discharge springs today, as well as other taxa typical of springs and wetlands, are common in the black mats. Several new species that lived in the saturated subsurface also are present, but lacustrine ostracodes are absent. The ??13C values of organic matter in the black mats range from -12 to -26???, reflecting contributions of tissue from both C3 (sedges, most shrubs and trees) and C4 (saltbush, saltgrass) plants. Carbon-14 dates on the humate fraction of 55 black mats fall between 11,800 to 6300 and 2300 14C yr B.P. to modern. The total absence of mats in our sample between 6300 and 2300 14C yr B.P. likely reflects increased aridity associated with the mid-Holocene Altithermal. The oldest black mats date to 11,800-11,600 14C yr B.P., and the peak in the 14C black mat distribution falls at ???10,000 14C yr B.P. As the formation of black mats is spring related, their abundance reflects refilling of valley aquifers starting no later than 11,800 and peaking after 11,000 14C yrB.P. Reactivation of spring-fed channels shortly before 11,200 14C yr B.P. is also apparent in the stratigraphic records from the Las Vegas and Pahrump Valleys. This age distribution suggests that black mats and related spring-fed channels in part may have formed in response to Younger Dryas (YD)-age recharge in the region. However, the

Black Mats, Spring-Fed Streams, and Late-Glacial-Age Recharge in the Southern Great Basin

NASA Astrophysics Data System (ADS)

Quade, Jay; Forester, Richard M.; Pratt, William L.; Carter, Claire

1998-03-01

Black mats are prominent features of the late Pleistocene and Holocene stratigraphic record in the southern Great Basin. Faunal, geochemical, and sedimentological evidence shows that the black mats formed in several microenvironments related to spring discharge, ranging from wet meadows to shallow ponds. Small land snails such as Gastrocopta tappanianaand Vertigo berryiare the most common mollusk taxa present. Semiaquatic and aquatic taxa are less abundant and include Catinellids, Fossaria parva, Gyraulus parvus,and others living today in and around perennial seeps and ponds. The ostracodes Cypridopsis okeechobiand Scottia tumida,typical of seeps and low-discharge springs today, as well as other taxa typical of springs and wetlands, are common in the black mats. Several new species that lived in the saturated subsurface also are present, but lacustrine ostracodes are absent. The δ 13C values of organic matter in the black mats range from -12 to -26‰, reflecting contributions of tissue from both C 3(sedges, most shrubs and trees) and C 4(saltbush, saltgrass) plants. Carbon-14 dates on the humate fraction of 55 black mats fall between 11,800 to 6300 and 2300 14C yr B.P. to modern. The total absence of mats in our sample between 6300 and 2300 14C yr B.P. likely reflects increased aridity associated with the mid-Holocene Altithermal. The oldest black mats date to 11,800-11,600 14C yr B.P., and the peak in the 14C black mat distribution falls at ˜10,000 14C yr B.P. As the formation of black mats is spring related, their abundance reflects refilling of valley aquifers starting no later than 11,800 and peaking after 11,000 14C yr B.P. Reactivation of spring-fed channels shortly before 11,200 14C yr B.P. is also apparent in the stratigraphic records from the Las Vegas and Pahrump Valleys. This age distribution suggests that black mats and related spring-fed channels in part may have formed in response to Younger Dryas (YD)-age recharge in the region. However, the

MAT - MULTI-ATTRIBUTE TASK BATTERY FOR HUMAN OPERATOR WORKLOAD AND STRATEGIC BEHAVIOR RESEARCH

NASA Technical Reports Server (NTRS)

Comstock, J. R.

1994-01-01

MAT, a Multi-Attribute Task battery, gives the researcher the capability of performing multi-task workload and performance experiments. The battery provides a benchmark set of tasks for use in a wide range of laboratory studies of operator performance and workload. MAT incorporates tasks analogous to activities that aircraft crew members perform in flight, while providing a high degree of experiment control, performance data on each subtask, and freedom to use non-pilot test subjects. The MAT battery primary display is composed of four separate task windows which are as follows: a monitoring task window which includes gauges and warning lights, a tracking task window for the demands of manual control, a communication task window to simulate air traffic control communications, and a resource management task window which permits maintaining target levels on a fuel management task. In addition, a scheduling task window gives the researcher information about future task demands. The battery also provides the option of manual or automated control of tasks. The task generates performance data for each subtask. The task battery may be paused and onscreen workload rating scales presented to the subject. The MAT battery was designed to use a serially linked second computer to generate the voice messages for the Communications task. The MATREMX program and support files, which are included in the MAT package, were designed to work with the Heath Voice Card (Model HV-2000, available through the Heath Company, Benton Harbor, Michigan 49022); however, the MATREMX program and support files may easily be modified to work with other voice synthesizer or digitizer cards. The MAT battery task computer may also be used independent of the voice computer if no computer synthesized voice messages are desired or if some other method of presenting auditory messages is devised. MAT is written in QuickBasic and assembly language for IBM PC series and compatible computers running MS-DOS. The

STS-133 crew members Lindsey, Boe and Drew during Tool/Repair Kits training with instructor

NASA Image and Video Library

2010-01-26

JSC2010-E-014262 (26 Jan. 2010) --- NASA astronauts Eric Boe (left), STS-133 pilot; Steve Lindsey, commander; and Alvin Drew, mission specialist, participate in an ISS tools and repair kits training session in the Space Vehicle Mock-up Facility at NASA's Johnson Space Center. Instructor Ivy Apostolakopoulos assisted the crew members.

Increasing Mechanical Properties of 2-D-Structured Electrospun Nylon 6 Non-Woven Fiber Mats

PubMed Central

Xiang, Chunhui; Frey, Margaret W.

2016-01-01

Tensile strength, Young’s modulus, and toughness of electrospun nylon 6 non-woven fiber mats were improved by increasing individual nanofiber strength and fiber–fiber load sharing. Single-walled carbon nanotubes (CNTs) were used as reinforcement to increase the strength of the electrospun nylon 6 nanofibers. Young’s modulus, tensile strength, and toughness of the nylon 6 non-woven fiber mats electrospun from 20 wt % solutions increased 51%, 87%, and 136%, respectively, after incorporating 1 wt % CNTs into the nylon 6 nanofibers. Three methods were investigated to enhance fiber–fiber load sharing: increasing friction between fibers, thermal bonding, and solvent bonding. The addition of beaded nylon 6 nanofibers into the non-woven fiber mats to increase fiber-fiber friction resulted in a statistically significantly increase in Young’s modulus over comparable smooth non-woven fiber mats. After annealing, tensile strength, elongation, and toughness of the nylon 6 non-woven fiber mats electrospun from 20 wt % + 10 wt % solutions increased 26%, 28%, and 68% compared to those from 20 wt % solutions. Solvent bonding with formic acid vapor at room temperature for 30 min caused increases of 56%, 67%, and 39% in the Young’s modulus, tensile strength, and toughness of non-woven fiber mats, respectively. The increases attributed to increased individual nanofiber strength and solvent bonding synergistically resulted in the improvement of Young’s modulus of the electrospun nylon 6 non-woven fiber mats. PMID:28773397

Optical properties of benthic photosynthetic communities: fiber-optic studies of cyanobacterial mats

NASA Technical Reports Server (NTRS)

Jorgensen, B. B.; Des Marais, D. J.

1988-01-01

A fiber-optic microphobe was used to analyze the spectral light gradients in benthic cyanobacterial mats with 50-micrometer depth resolution and 10-nm spectral resolution. Microcoleus chthononplastes mats were collected from hypersaline, coastal ponds at Guerrero Negro, Baja California. Gradients of spectral radiance, L, were measured at different angles through the mats and the spherically integrated scalar irradiance, Eo, was calculated. Maximal spectral light attenuation was found at the absorption peaks for the dominant photosynthetic pigments: chlorophyll a at 430 and 670 nm, carotenoids at 450-500 nm, phycocyanin at 620 nm, and bacteriochlorophyll a at 800-900 nm. Scattered light had a marked spectral effect on the scalar irradiance which near the mat surface reached up to 190% of the incident irradiance. The spherically integrated irradiance thus differed strongly from the incident irradiance both in total intensity and in spectral composition. These basic optical properties are important for the understanding of photosynthesis and light harvesting in benthic and epiphytic communities.

An extraterrestrial habitat on earth: The algal mat of Don Jaun Pond

NASA Astrophysics Data System (ADS)

Siegel, B. Z.; Siegel, S. M.; Chen, J.; Larock, P.

On the edge of Don Juan Pond in the Wright Valley of Antarctica lies a mat of mineral and detritus cemented by organic matter. In spite of a CaCl2 concentration of about 33% (w/v), the mat contains Oscillatoria and other cyanobacteria, unicellular forms, colonial forms rich in carotenoids, and diatoms. Bacteria are rare; fungal filaments are not. Oscillatoria showed motility, but only at temperatures <10°C. Acetone extracts of the mat and nearby muds yielded visible spectra similar to those of laboratory grown O. sancta, with 50- to 70-fold molar ratio of chlorophyll a to b. Although rare, tardigrades were also found. The algal mat had enzymatic activities characteristic of peroxidase, catalase, dehydrogenase, and amylase. Cellulose, chitin, protein, lipid and ATP were present. Previously, algae in the Wright Valley have been described in melt water, not in the brine itself. Wright Valley has been used as a near sterile Martian model. It obviously contains an array of hardy terrestrial organisms.

Setting the stage for the EPOS ERIC: Integration of the legal, governance and financial framework

NASA Astrophysics Data System (ADS)

Atakan, Kuvvet; Bazin, Pierre-Louis; Bozzoli, Sabrina; Freda, Carmela; Giardini, Domenico; Hoffmann, Thomas; Kohler, Elisabeth; Kontkanen, Pirjo; Lauterjung, Jörn; Pedersen, Helle; Saleh, Kauzar; Sangianantoni, Agata

2017-04-01

EPOS - the European Plate Observing System - is the ESFRI infrastructure serving the need of the solid Earth science community at large. The EPOS mission is to create a single sustainable, and distributed infrastructure that integrates the diverse European Research Infrastructures for solid Earth science under a common framework. Thematic Core Services (TCS) and Integrated Core Services (Central Hub, ICS-C and Distributed, ICS-D) are key elements, together with NRIs (National Research Infrastructures), in the EPOS architecture. Following the preparatory phase, EPOS has initiated formal steps to adopt an ERIC legal framework (European Research Infrastructure Consortium). The statutory seat of EPOS will be in Rome, Italy, while the ICS-C will be jointly operated by France, UK and Denmark. The TCS planned so far cover: seismology, near-fault observatories, GNSS data and products, volcano observations, satellite data, geomagnetic observations, anthropogenic hazards, geological information modelling, multiscale laboratories and geo-energy test beds for low carbon energy. In the ERIC process, EPOS and all its services must achieve sustainability from a legal, governance, financial, and technical point of view, as well as full harmonization with national infrastructure roadmaps. As EPOS is a distributed infrastructure, the TCSs have to be linked to the future EPOS ERIC from legal and governance perspectives. For this purpose the TCSs have started to organize themselves as consortia and negotiate agreements to define the roles of the different actors in the consortium as well as their commitment to contribute to the EPOS activities. The link to the EPOS ERIC shall be made by service agreements of dedicated Service Providers. A common EPOS data policy has also been developed, based on the general principles of Open Access and paying careful attention to licensing issues, quality control, and intellectual property rights, which shall apply to the data, data products

Validation of FRP Matting Requirements

DTIC Science & Technology

2016-08-01

airfield pavements using crushed stone. A side-by-side comparison between FRP and folded fiberglass matting (FFM) was performed on simulated small...medium, and large craters in Portland cement concrete and asphalt concrete pavements . The demonstration took place at the Silver Flag Exercise Site...report are not to be construed as an official Department of the Army position unless so designated by other authorized documents. DESTROY THIS

Lipophilic pigments from cyanobacterial (blue-green algal) and diatom mats in Hamelin Pool, Shark Bay, Western Australia

NASA Technical Reports Server (NTRS)

Palmisano, A. C.; Summons, R. E.; Cronin, S. E.; Des Marais, D. J.

1989-01-01

Lipophilic pigments were examined in microbial mat communities dominated by cyanobacteria in the intertidal zone and by diatoms in the subtidal and sublittoral zones of Hamelin Pool, Shark Bay, Western Australia. These microbial mats have evolutionary significance because of their similarity to lithfied stromatolites from the Proterozoic and Early Paleozoic eras. Fucoxanthin, diatoxanthin, diadinoxanthin, beta-carotene, and chlorophylls a and c characterized the diatom mats, whereas cyanobacterial mats contained myxoxanthophyll, zeaxanthin, echinenone, beta-carotene, chlorophyll a and, in some cases, sheath pigment. The presence of bacteriochlorophyll a within the mats suggest a close association of photosynthetic bacteria with diatoms and cyanobacteria. The high carotenoids : chlorophyll a ratios (0.84-2.44 wt/wt) in the diatom mats suggest that carotenoids served a photoprotective function in this high light environment. By contrast, cyanobacterial sheath pigment may have largely supplanted the photoprotective role of carotenoids in the intertidal mats.

Mineralogy of Iron Microbial Mats from Loihi Seamount

PubMed Central

Toner, Brandy M.; Berquó, Thelma S.; Michel, F. Marc; Sorensen, Jeffry V.; Templeton, Alexis S.; Edwards, Katrina J.

2011-01-01

Extensive mats of Fe oxyhydroxides and associated Fe-oxidizing microbial organisms form in diverse geochemical settings – freshwater seeps to deep-sea vents – where ever opposing Fe(II)-oxygen gradients prevail. The mineralogy, reactivity, and structural transformations of Fe oxyhydroxides precipitated from submarine hydrothermal fluids within microbial mats remains elusive in active and fossil systems. In response, a study of Fe microbial mat formation at the Loihi Seamount was conducted to describe the physical and chemical characteristics of Fe-phases using extended X-ray absorption fine structure spectroscopy, powder X-ray diffraction, synchrotron radiation X-ray total scattering, low-temperature magnetic measurements, and Mössbauer spectroscopy. Particle sizes of 3.5–4.6 nm were estimated from magnetism data, and coherent scattering domain (CSD) sizes as small as 1.6 nm are indicated by pair distribution function (PDF) analysis. Disorder in the nanostructured Fe-bearing phases results in limited intermediate-range structural order: less than that of standard two-line ferrihydrite (Fh), except for the Pohaku site. The short-range ordered natural Fh (FhSRO) phases were stable at 4°C in the presence of oxygen for at least 1 year and during 400°C treatment. The observed stability of the FhSRO is consistent with magnetic observations that point to non-interacting nanoparticles. PDF analyses of total scattering data provide further evidence for FhSRO particles with a poorly ordered silica coating. The presence of coated particles explains the small CSD for the mat minerals, as well as the stability of the minerals over time and against heating. The mineral properties observed here provide a starting point from which progressively older and more extensively altered Fe deposits may be examined, with the ultimate goal of improved interpretation of past biogeochemical conditions and diagenetic processes. PMID:22485113

Study on the Strength of GFRP/Stainless Steel Adhesive Joints Reinforced with Glass Mat

NASA Astrophysics Data System (ADS)

Iwasa, Masaaki

The adhesive strengths of glass fiber reinforced plastics/metal adhesive joints reinforced with glass mat under tensile shear loads and tensile loads were investigated analytically and experimentally. First, the stress singularity parameters of the bonding edges were analyzed by FEM for various types of adhesive joints reinforced with glass mat. The shear stress and normal stress distributions near the bonding edge can be expressed by two stress singularity parameters. Second, tensile shear tests were performed on taper lap joint and taper lap joint reinforced with glass mat and tensile tests were performed on T-type adhesive joint and T-type adhesive joint reinforced with glass mat. The relationships between the loads and the crosshead displacements were measured. We concluded that reinforcing adhesive joints has a greater effect on strength under tensile load than under tensile shear load. The adhesive joints strength reinforced with glass mat can be evaluated by using stress singularity parameters.

Engineering and Scientific Applications: Using MatLab(Registered Trademark) for Data Processing and Visualization

NASA Technical Reports Server (NTRS)

Sen, Syamal K.; Shaykhian, Gholam Ali

2011-01-01

MatLab(TradeMark)(MATrix LABoratory) is a numerical computation and simulation tool that is used by thousands Scientists and Engineers in many countries. MatLab does purely numerical calculations, which can be used as a glorified calculator or interpreter programming language; its real strength is in matrix manipulations. Computer algebra functionalities are achieved within the MatLab environment using "symbolic" toolbox. This feature is similar to computer algebra programs, provided by Maple or Mathematica to calculate with mathematical equations using symbolic operations. MatLab in its interpreter programming language form (command interface) is similar with well known programming languages such as C/C++, support data structures and cell arrays to define classes in object oriented programming. As such, MatLab is equipped with most of the essential constructs of a higher programming language. MatLab is packaged with an editor and debugging functionality useful to perform analysis of large MatLab programs and find errors. We believe there are many ways to approach real-world problems; prescribed methods to ensure foregoing solutions are incorporated in design and analysis of data processing and visualization can benefit engineers and scientist in gaining wider insight in actual implementation of their perspective experiments. This presentation will focus on data processing and visualizations aspects of engineering and scientific applications. Specifically, it will discuss methods and techniques to perform intermediate-level data processing covering engineering and scientific problems. MatLab programming techniques including reading various data files formats to produce customized publication-quality graphics, importing engineering and/or scientific data, organizing data in tabular format, exporting data to be used by other software programs such as Microsoft Excel, data presentation and visualization will be discussed.

[Book Review] Waterfowl ecology and management by Guy A. Baldassarre and Eric G. Bolen

USGS Publications Warehouse

Olsen, Glenn H.

2007-01-01

A review of: Waterfowl Ecology and Management. Second Edition. By Guy A Baldassarre and , Eric G Bolen; illustrated by , Tamara R Sayre. Malabar (Florida): Krieger Publishing. $112.50. xii + 567 p; ill.; index. ISBN: 1‐57524‐260‐5. 2006

Identification of Desulfobacterales as primary hydrogenotrophs in a complex microbial mat community

DOE PAGES

Burow, L. C.; Woebken, D.; Marshall, I. P. G.; ...

2014-04-15

Hypersaline microbial mats have been shown to produce significant quantities of H 2 under dark, anoxic conditions via cyanobacterial fermentation. This flux of a widely accessible microbial substrate has potential to significantly influence the ecology of the mat, and any consumption will affect the net efflux of H 2 that might otherwise be captured as a resource. Here, we focus on H 2 consumption in a microbial mat from Elkhorn Slough, California, USA, for which H 2 production has been previously characterized. Active biologic H 2 consumption in this mat is indicated by a significant time-dependent decrease in added Hmore » 2 compared with a killed control. Inhibition of sulfate reduction, as indicated by a decrease in hydrogen sulfide production relative to controls, resulted in a significant increase in H 2 efflux, suggesting that sulfate-reducing bacteria (SRB) are important hydrogenotrophs. Low methane efflux under these same conditions indicated that methanogens are likely not important hydrogenotrophs. Analyses of genes and transcripts that encode for rRNA or dissimilatory sulfite reductase, using both PCR-dependent and PCR-independent metatranscriptomic sequencing methods, demonstrated that Desulfobacterales are the dominant, active SRB in the upper, H 2-producing layer of the mat (0–2 mm). This hypothesis was further supported by the identification of transcripts encoding hydrogenases derived from Desulfobacterales capable of H 2 oxidation. Analysis of molecular data provided no evidence for the activity of hydrogenotrophic methanogens. Lastly, the combined biogeochemical and molecular data strongly indicate that SRB belonging to the Desulfobacterales are the quantitatively important hydrogenotrophs in the Elkhorn Slough mat.« less

Morphological Survey of Microbial Mats Near Deep-Sea Thermal Vents †

PubMed Central

Jannasch, Holger W.; Wirsen, Carl O.

1981-01-01

A microscopic survey is presented of the most commonly observed and morphologically conspicuous microorganisms found attached to natural surfaces or to artificial materials deposited in the immediate vicinity of thermal submarine vents at the Galapagos Rift ocean spreading zone at a depth of 2,550 meters. Of special interest were the following findings: (i) all surfaces intermittently exposed to H2S-containing hydrothermal fluid were covered by layers, ca. 5 to 10 μm thick, of procaryotic, gram-negative cells interspaced with amorphous metal (Mn-Fe) deposits; (ii) although some of the cells were encased by dense metal deposits, there was little apparent correlation between metal deposition and the occurrence of microbial mats, (iii) highly differentiated forms appeared to be analogues of certain cyanobacteria, (iv) isolates from massive mats of a prosthecate bacterium could be identified as Hyphomicrobium spp., (v) intracellular membrane systems similar to those found in methylotrophic and nitrifying bacteria were observed in approximately 20% of the cells composing the mats, (vi) thiosulfate enrichments made from mat material resulted in isolations of different types of sulfur-oxidizing bacteria including the obligately chemolithotrophic genus Thiomicrospira. Images PMID:16345722

Localized electron transfer rates and microelectrode-based enrichment of microbial communities within a phototrophic microbial mat

DOE Office of Scientific and Technical Information (OSTI.GOV)

Babauta, Jerome T.; Atci, Erhan; Ha, Phuc T.

2014-01-01

Phototrophic microbial mats frequently exhibit sharp, light-dependent redox gradients that regulate microbial respiration on specific electron acceptors as a function of depth. In this work, a benthic phototrophic microbial mat from Hot Lake, a hypersaline, epsomitic lake located near Oroville in north-central Washington, was used to develop a microscale electrochemical method to study local electron transfer processes within the mat. To characterize the physicochemical variables influencing electron transfer, we initially quantified redox potential, pH, and dissolved oxygen gradients by depth in the mat under photic and aphotic conditions. We further demonstrated that power output of a mat fuel cell wasmore » light-dependent. To study local electron transfer processes, we deployed a microscale electrode (microelectrode) with tip size ~20 μm. To enrich a subset of microorganisms capable of interacting with the microelectrode, we anodically polarized the microelectrode at depth in the mat. Subsequently, to characterize the microelectrode- associated community and compare it to the neighboring mat community, we performed amplicon sequencing of the V1-V3 region of the 16S gene. Differences in Bray-Curtis beta diversity, illustrated by large changes in relative abundance at the phylum level, suggested successful enrichment of specific mat community members on the microelectrode surface. The microelectrode-associated community exhibited substantially reduced alpha diversity and elevated relative abundances of Prosthecochloris, Loktanella, Catellibacterium, other unclassified members of Rhodobacteraceae, Thiomicrospira, and Limnobacter, compared with the community at an equivalent depth in the mat. Our results suggest that local electron transfer to an anodically polarized microelectrode selected for a specific microbial population, with substantially more abundance and diversity of sulfur-oxidizing phylotypes compared with the neighboring mat community.« less

How To Use the SilverPlatter Software To Search the ERIC CD ROM.

ERIC Educational Resources Information Center

Merrill, Paul F.

This manual provides detailed instructions for using SilverPlatter software to search the ERIC CD ROM (Compact Disk Read Only Memory), a large bibliographic database relating to education which contains reference information on numerous journal articles from over 750 journals cited in the "Current Index to Journals in Education" (CIJE),…

Assembly and Succession of Iron Oxide Microbial Mat Communities in Acidic Geothermal Springs

DOE PAGES

Beam, Jacob P.; Bernstein, Hans C.; Jay, Zackary J.; ...

2016-02-15

Biomineralized ferric oxide microbial mats are ubiquitous features on Earth, are common in hot springs of Yellowstone National Park (YNP, WY, USA), and form due to direct interaction between microbial and physicochemical processes. The overall goal of this study was to determine the contribution of different community members to the assembly and succession of acidic high-temperature Fe(III)-oxide mat ecosystems. Spatial and temporal changes in Fe(III)-oxide accretion and the abundance of relevant community members were monitored over 70 days using sterile glass microscope slides incubated in the outflow channels of two acidic geothermal springs (pH = 3-3.5; temperature = 68-75°C) inmore » YNP. Hydrogenobaculum spp. were the most abundant taxon identified during early successional stages (4-40 days), and have been shown to oxidize arsenite, sulfide, and hydrogen coupled to oxygen reduction. Iron-oxidizing populations of Metallosphaera yellowstonensis were detected within 4 days, and reached steady-state levels within 14-30 days, corresponding to visible Fe(III)-oxide accretion. Heterotrophic archaea colonized near 30 days, and emerged as the dominant functional guild after 70 days and in mature Fe(III)-oxide mats (1-2 cm thick). First-order rate constants of Fe(III)-oxide accretion ranged from 0.046 to 0.05 day -1 , and in situ microelectrode measurements showed that the oxidation of Fe(II) is limited by the diffusion of O2 into the Fe(III)-oxide mat. The formation of microterracettes also implicated O2 as a major variable controlling microbial growth and subsequent mat morphology. The assembly and succession of Fe(III)-oxide mat communities follows a repeatable pattern of colonization by lithoautotrophic organisms, and the subsequent growth of diverse organoheterotrophs. The unique geochemical signatures and micromorphology of extant biomineralized Fe(III)-oxide mats are also useful for understanding other Fe(II)-oxidizing systems.« less

Assembly and Succession of Iron Oxide Microbial Mat Communities in Acidic Geothermal Springs.

PubMed

Beam, Jacob P; Bernstein, Hans C; Jay, Zackary J; Kozubal, Mark A; Jennings, Ryan deM; Tringe, Susannah G; Inskeep, William P

2016-01-01

Biomineralized ferric oxide microbial mats are ubiquitous features on Earth, are common in hot springs of Yellowstone National Park (YNP, WY, USA), and form due to direct interaction between microbial and physicochemical processes. The overall goal of this study was to determine the contribution of different community members to the assembly and succession of acidic high-temperature Fe(III)-oxide mat ecosystems. Spatial and temporal changes in Fe(III)-oxide accretion and the abundance of relevant community members were monitored over 70 days using sterile glass microscope slides incubated in the outflow channels of two acidic geothermal springs (pH = 3-3.5; temperature = 68-75°C) in YNP. Hydrogenobaculum spp. were the most abundant taxon identified during early successional stages (4-40 days), and have been shown to oxidize arsenite, sulfide, and hydrogen coupled to oxygen reduction. Iron-oxidizing populations of Metallosphaera yellowstonensis were detected within 4 days, and reached steady-state levels within 14-30 days, corresponding to visible Fe(III)-oxide accretion. Heterotrophic archaea colonized near 30 days, and emerged as the dominant functional guild after 70 days and in mature Fe(III)-oxide mats (1-2 cm thick). First-order rate constants of Fe(III)-oxide accretion ranged from 0.046 to 0.05 day(-1), and in situ microelectrode measurements showed that the oxidation of Fe(II) is limited by the diffusion of O2 into the Fe(III)-oxide mat. The formation of microterracettes also implicated O2 as a major variable controlling microbial growth and subsequent mat morphology. The assembly and succession of Fe(III)-oxide mat communities follows a repeatable pattern of colonization by lithoautotrophic organisms, and the subsequent growth of diverse organoheterotrophs. The unique geochemical signatures and micromorphology of extant biomineralized Fe(III)-oxide mats are also useful for understanding other Fe(II)-oxidizing systems.

Sulfate-reducing bacteria and their activities in cyanobacterial mats of Solar Lake (Sinai, Egypt)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Teske, A.; Ramsing, N.B.; Habicht, K.

1998-08-01

The sulfate-reducing bacteria within the surface layer of the hypersaline cyanobacterial mat of Solar Lake (Sinai, Egypt) were investigated with combined microbiological, molecular, and biogeochemical approaches. The diurnally oxic surface layer contained between 10{sup 6} and 10{sup 7} cultivable sulfate-reducing bacteria ml{sup {minus}1} day{sup {minus}1}, both in the same range as and sometimes higher than those in anaerobic deeper mat layers. In the oxic surface layer and in the mat layers below, filamentous sulfate-reducing Desulfonema bacteria were found in variable densities of 10{sup 4} and 10{sup 6} cells ml{sup {minus}1}. A Desulfonema-related, diurnally migrating bacterium was detected with PCR andmore » denaturing gradient gel electrophoresis within and below the oxic surface layer. Facultative aerobic respiration, filamentous morphology, motility, diurnal migration, and aggregate formation were the most conspicuous adaptations of Solar Lake sulfate-reducing bacteria to the mat matrix and to diurnal oxygen stress. A comparison of sulfate reduction rates within the mat and previously published photosynthesis rates showed that CO{sub 2} from sulfate reduction in the upper 5 mm accounted for 7 to 8% of the total photosynthetic CO{sub 2} demand of the mat.« less

Development of feedback-speed-control system of fixed-abrasive tool for mat-surface fabrication

NASA Astrophysics Data System (ADS)

Yanagihara, K.; Kita, R.

2018-01-01

This study deals with the new method to fabricate a mat-surface by using fixed-abrasive tool. Mat-surface is a surface with microscopic irregularities whose dimensions are close to the wavelengths of visible light (400-700 nanometers). In order to develop the new method to fabricate mat-surface without pre-masking and large scale back up facility, utilization of fixed-abrasive tool is discussed. The discussion clarifies that abrasives in shot blasting are given kinetic energy along to only plunge-direction while excluding traverse-direction. If the relative motion between tool and work in fixed-abrasive process can be realized as that in blasting, mat-surface will be accomplished with fixed-abrasive process. To realize the proposed idea, new surface-fabrication system to which is adopted feedback-speed-control of abrasive wheel has been designed. The system consists of micro-computer unit (MPU), work-speed sensor, fixed-abrasive wheel, and wheel driving unit. The system can control relative speed between work and wheel in optimum range to produce mat-surface. Finally experiment to verify the developed system is carried out. The results of experiments show that the developed system is effective and it can produce the surface from grinding to mat-surface seamlessly.

Electron microscopy study of microbial mat in the North Fiji basin hydrothermal vent

NASA Astrophysics Data System (ADS)

Park, H.; Kim, J. W.; Lee, J. W.

2017-12-01

Hydrothermal vent systems consisting of hydrothermal vent, hydrothermal sediment and microbial mat are widely spread around the ocean, particularly spreading axis, continental margin and back-arc basin. Scientists have perceived that the hydrothermal systems, which reflect the primeval earth environment, are one of the best places to reveal the origin of life and extensive biogeochemical process of microbe-mineral interaction. In the present study multiline of analytical methods (X-Ray Diffraction (XRD), Scanning Electron Microscopy (SEM) and Transmission Electron Microscopy (TEM)) were utilized to investigate the mineralogy/chemistry of microbe-mineral interaction in hydrothermal microbial mat. Microbial mat samples were recovered by Canadian scientific submersible ROPOS on South Pacific North Fiji basin KIOST hydrothermal vent expedition 1602. XRD analysis showed that red-colored microbial mat contains Fe-oxides and Fe-oxyhydroxides. Various morphologies of minerals in the red-colored microbial mat observed by SEM are mainly showed sheath shaped, resembled with Leptothrix microbial structure, stalks shaped, similar with Marioprofundus microbial structure and globule shaped microbial structures. They are also detected with DNA analysis. The cross sectional observation of microbial structures encrusted with Fe-oxide and Fe-oxyhydroxide at a nano scale by Transmission Electron Microscopy (TEM) and Focused Ion Beam (FIB) technique was developed to verify the structural/biogeochemical properties in the microbe-mineral interaction. Systematic nano-scale measurements on the biomineralization in the microbial mat leads the understandings of biogeochemical environments around the hydrothermal vent.

14. 'ANNISQUAM POINT JAN. 4, 1898.' Photocopy of photograph ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

14. 'ANNISQUAM POINT -- JAN. 4, 1898.' Photocopy of photograph (original glass plate negative #T86 in the collection of the Annisquam Historical Society, Annisquam, Massachusetts). Photographer: Martha Harvey (1862-1949). (The handwritten legend along the top edge of the photograph is scratched in the emulsion of the original glass plate negative. Consequently it reads in reverse when printed.) - Annisquam Bridge, Spanning Lobster Cove between Washington & River Streets, Gloucester, Essex County, MA

The impact of long-term hydrocarbon exposure on the structure, activity, and biogeochemical functioning of microbial mats.

PubMed

Aubé, Johanne; Senin, Pavel; Pringault, Olivier; Bonin, Patricia; Deflandre, Bruno; Bouchez, Olivier; Bru, Noëlle; Biritxinaga-Etchart, Edurne; Klopp, Christophe; Guyoneaud, Rémy; Goñi-Urriza, Marisol

2016-10-15

Photosynthetic microbial mats are metabolically structured systems driven by solar light. They are ubiquitous and can grow in hydrocarbon-polluted sites. Our aim is to determine the impact of chronic hydrocarbon contamination on the structure, activity, and functioning of a microbial mat. We compared it to an uncontaminated mat harboring similar geochemical characteristics. The mats were sampled in spring and fall for 2years. Seasonal variations were observed for the reference mat: sulfur cycle-related bacteria dominated spring samples, while Cyanobacteria dominated in autumn. The contaminated mat showed minor seasonal variation; a progressive increase of Cyanobacteria was noticed, indicating a perturbation of the classical seasonal behavior. Hydrocarbon content was the main factor explaining the differences in the microbial community structure; however, hydrocarbonoclastic bacteria were among rare or transient Operational Taxonomic Units (OTUs) in the contaminated mat. We suggest that in long-term contaminated systems, hydrocarbonoclastic bacteria cannot be considered a sentinel of contamination. Copyright © 2016 Elsevier Ltd. All rights reserved.

[Inefficiency of electrosmog-shielding mats. Part 2: radio frequency range].

PubMed

Leitgeb, N; Cech, R

2005-09-01

It could already be shown that electromagnetic shielding mats do not reduce but even enhance electric field exposure in daily life situations. By measurements and numerical simulations the claims of manufacturers were checked who pretend that radio frequency electromagnetic fields can be shielded to 99% and more, and transferred to earth by earth cables (if attached). It could be shown that in the radio frequency range such products do not fulfil the justified expectations of customers, but in most cases even cause the opposite. The results depend on the electric properties of the material. Good electric conductivity of shielding mats even considerably increases electromagnetic field exposure. To connect the mats with earth potential by an attached cable might increase the beliefs on a protective effect, however, this is not capable to enhance the shielding effect. The investigation demonstrates that in spite of references made to experts opinions manufacturers claims about the shielding efficiency of radio frequency fields are misleading and fool clients about the real situation. Overall, acquisition and use of electrosmog shielding mats must be discouraged. If at all, shielding can be reached by placing a shielding cover between the source and the person. However, even in this case, efficiency is much lower than promised by manufacturers and decreases even more if it is taken into account that the head naturally remains uncovered and hence unshielded.

The ichthyofauna of drifting macrophyte mats in the Ivinhema River, upper Paraná River basin, Brazil

USGS Publications Warehouse

Bulla, C. K.; Gomes, Luiz Carlos; Miranda, Leandro E.; Agostinho, A. A.

2011-01-01

We describe the fish assemblages associated with drifting macrophyte mats and consider their possible role as dispersal vectors in the Ivinhema River, a major tributary of the upper Paraná River, Brazil. Fish associated with drifting mats were sampled in the main river channel during January and March 2005, when the wind and/or the increased water level were sufficient to transport macrophyte stands. Fish in the drifting mats were sampled with a floating sieve (4 m long x 2 m wide x 0.6 m high, and 2 mm mesh size). In the laboratory, larvae, juvenile, and adult fish were counted and identified to the lowest possible taxonomic level. In four drifting macrophyte mats we captured 218 individuals belonging to at least 28 species, 17 families, and 6 orders. Aphyocharax dentatus, Serrasalmus spp., and Trachelyopterus galeatus were the most abundant taxa associated with the mats, but species richness ranged from 6 to 24 species per mat. In addition, 85% of the total number of individuals caught was larvae and juveniles. Although preliminary and based on limited samples, this study of drifting macrophyte mats was the first one in the last unregulated stretch of the Paraná River remaining inside Brazilian territory, and alerts us to the potential role of macrophytes mats as dispersers of fish species in the region.

When to Go to the Mat

ERIC Educational Resources Information Center

Smith, Carol A.

2017-01-01

School leaders rightly tend toward collaboration and consensus-building when it comes to important decisions affecting students. But there are moments when, perhaps to their own surprise, they may find themselves willing to "go to the mat" on an important decision, whether consensus has been reached or not. Smith, a professor and chair…

Microbial Diversity and Lipid Abundance in Microbial Mats from a Sulfidic, Saline, Warm Spring in Utah, USA

NASA Astrophysics Data System (ADS)

Gong, J.; Edwardson, C.; Mackey, T. J.; Dzaugis, M.; Ibarra, Y.; Course 2012, G.; Frantz, C. M.; Osburn, M. R.; Hirst, M.; Williamson, C.; Hanselmann, K.; Caporaso, J.; Sessions, A. L.; Spear, J. R.

2012-12-01

The microbial diversity of Stinking Springs, a sulfidic, saline, warm spring northeast of the Great Salt Lake was investigated. The measured pH, temperature, salinity, and sulfide concentration along the flow path ranged from 6.64-7.77, 40-28° C, 2.9-2.2%, and 250 μM to negligible, respectively. Five sites were selected along the flow path and within each site microbial mats were dissected into depth profiles based on the color and texture of the mat layers. Genomic DNA was extracted from each layer, and the 16S rRNA gene was amplified and sequenced on the Roche 454 Titanium platform. Fatty acids were also extracted from the mat layers and analyzed by liquid chromatography and mass spectrometry. The mats at Stinking Springs were classified into roughly two morphologies with respect to their spatial distribution: loose, sometimes floating mats proximal to the spring source; and thicker, well-laminated mats distal to the spring source. Loosely-laminated mats were found in turbulent stream flow environments, whereas well-laminated mats were common in less turbulent sheet flows. Phototrophs, sulfur oxidizers, sulfate reducers, methanogens, other bacteria and archaea were identified by 16S rRNA gene sequences. Diatoms, identified by microscopy and lipid analysis were found to increase in abundance with distance from the source. Methanogens were generally more abundant in deeper mat laminae. Photoheterotrophs were found in all mat layers. Microbial diversity increased significantly with depth at most sites. In addition, two distinct microbial streamers were identified and characterized at the two fast flowing sites. These two streamer varieties were dominated by either cyanobacteria or flavobacteria. Overall, our genomic and lipid analysis suggest that the physical and chemical environment is more predictive of the community composition than mat morphology. Site Map

Magnetoacoustic Tomography with Magnetic Induction (MAT-MI) for Breast Tumor Imaging: Numerical Modeling and Simulation

PubMed Central

Zhou, Lian; Li, Xu; Zhu, Shanan; He, Bin

2011-01-01

Magnetoacoustic tomography with magnetic induction (MAT-MI) was recently introduced as a noninvasive electrical conductivity imaging approach with high spatial resolution close to ultrasound imaging. In the present study, we test the feasibility of the MAT-MI method for breast tumor imaging using numerical modeling and computer simulation. Using the finite element method, we have built three dimensional numerical breast models with varieties of embedded tumors for this simulation study. In order to obtain an accurate and stable forward solution that does not have numerical errors caused by singular MAT-MI acoustic sources at conductivity boundaries, we first derive an integral forward method for calculating MAT-MI acoustic sources over the entire imaging volume. An inverse algorithm for reconstructing the MAT-MI acoustic source is also derived with spherical measurement aperture, which simulates a practical setup for breast imaging. With the numerical breast models, we have conducted computer simulations under different imaging parameter setups and all the results suggest that breast tumors that have large conductivity contrast to its surrounding tissues as reported in literature may be readily detected in the reconstructed MAT-MI images. In addition, our simulations also suggest that the sensitivity of imaging breast tumors using the presented MAT-MI setup depends more on the tumor location and the conductivity contrast between the tumor and its surrounding tissues than on the tumor size. PMID:21364262

UAV, DGPS, and Laser Transit Mapping of Microbial Mat Ecosystems on Little Ambergris Cay, B.W.I.

NASA Astrophysics Data System (ADS)

Stein, N.; Quinn, D. P.; Grotzinger, J. P.; Fischer, W. W.; Knoll, A. H.; Cantine, M.; Gomes, M. L.; Grotzinger, H. M.; Lingappa, U.; Metcalfe, K.; O'Reilly, S. S.; Orzechowski, E. A.; Riedman, L. A.; Strauss, J. V.; Trower, L.

2016-12-01

Little Ambergris Cay is a 6 km long, 1.6 km wide uninhabited island on the Caicos platform in the Turks and Caicos. Little Ambergris provides an analog for the study of microbial mat development in the sedimentary record. Recent field mapping during July of 2016 used UAV- and satellite-based images, differential GPS (DGPS), and total station theodolite (TST) measurements to characterize sedimentology and biofacies across the entirety of Little Ambergris Cay. Nine facies were identified in-situ during DGPS island transects including oolitic grainstone bedrock, sand flats, cutbank and mat-filled channels, hardground-lined bays with EPS-rich mat particles, mangroves, EPS mats, polygonal mats, and mats with blistered surface texture. These facies were mapped onto a 15 cm/pixel visible light orthomosaic of the island generated from more than 1500 nadir images taken by a UAV at 350 m standoff distance. A corresponding stereogrammetric digital elevation map was generated from drone images and 910 DGPS measurements acquired during several island transects. More than 1000 TST measurements provide additional facies elevation constraints, control points for satellite-based water depth calculations, and means to cross-calibrate and reconstruct the topographic profile of bedrock exposed at the beach. Additionally, the thickness of the underlying Holocene sediment fill was estimated over several island transects using a depth probe. Sub-cm resolution drone-based orthophotos of microbial mats were used to quantify polygonal mat size and textures. The mapping results highlight that sedimentary and bio-facies (including mat morphology and fabrics) correlate strongly with elevation. Notably, mat morphology was observed to be highly sensitive to cm-scale variations in topography and water depth. The productivity metric NDVI was computed for mat and vegetation facies using nadir images from a UAV-mounted two-band red-NIR camera. In combination with in situ facies mapping, these

58. Neg. No. F160a, Jan 11, 1933, INTERIOROFFICE BUILDING/ ASSEMBLY ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

58. Neg. No. F-160a, Jan 11, 1933, INTERIOR-OFFICE BUILDING/ ASSEMBLY BUILDING, FIRST AID ROOM - Ford Motor Company Long Beach Assembly Plant, Assembly Building, 700 Henry Ford Avenue, Long Beach, Los Angeles County, CA

Evaluation of gallic acid loaded zein sub-micron electrospun fibre mats as novel active packaging materials.

PubMed

Neo, Yun Ping; Swift, Simon; Ray, Sudip; Gizdavic-Nikolaidis, Marija; Jin, Jianyong; Perera, Conrad O

2013-12-01

The applicability of gallic acid loaded zein (Ze-GA) electrospun fibre mats towards potential active food packaging material was evaluated. The surface chemistry of the electrospun fibre mats was determined using X-ray photon spectroscopy (XPS). The electrospun fibre mats showed low water activity and whitish colour. Thermogravimetric analysis (TGA) and Attenuated Total Reflectance-Fourier Transform Infrared (ATR-FTIR) spectroscopy revealed the stability of the fibre mats over time. The Ze-GA fibre mats displayed similar rapid release profiles, with Ze-GA 20% exhibiting the fastest release rate in water as compared to the others. Gallic acid diffuses from the electrospun fibres in a Fickian diffusion manner and the data obtained exhibited a better fit to Higuchi model. L929 fibroblast cells were cultured on the electrospun fibres to demonstrate the absence of cytotoxicity. Overall, the Ze-GA fibre mats demonstrated antibacterial activity and properties consistent with those considered desirable for active packaging material in the food industry. Copyright © 2013 Elsevier Ltd. All rights reserved.

Career Academies: Educating Urban Students for Career Success. ERIC/CUE Digest, Number 84.

ERIC Educational Resources Information Center

Burnett, Gary

This ERIC Digest reviews the school restructuring tool of career academies serving the non-college bound student. The career academy movement began with the Electrical Academy in Philadelphia, Pennsylvania. The model was exported to California where it became the basis for the Peninsula Academies in the Sequoia Union High School District and from…

Reflecting on Attention-Deficient Hyperactivity Disorder and Disablement in Education with Eric Fromm

ERIC Educational Resources Information Center

Veck, Wayne

2012-01-01

Drawing upon the thought of Eric Fromm, this paper argues that efforts to understand and counter behaviour that causes difficulties in education should begin in a critical and reflective engagement with both the conditions of human freedom and the character of educational institutions and society as a whole. Fromm's critique of dominating ideas…

Learning about the Human Genome. Part 2: Resources for Science Educators. ERIC Digest.

ERIC Educational Resources Information Center

Haury, David L.

This ERIC Digest identifies how the human genome project fits into the "National Science Education Standards" and lists Human Genome Project Web sites found on the World Wide Web. It is a resource companion to "Learning about the Human Genome. Part 1: Challenge to Science Educators" (Haury 2001). The Web resources and…

What Can I Become: Educational Aspirations of Students in Rural America. ERIC Digest.

ERIC Educational Resources Information Center

Haas, Toni

This ERIC Digest reports on the educational aspirations of rural youth compared with students living in urban and suburban areas. Research indicates that in comparison to urban youth, rural young people felt their parents were much more supportive of their taking full-time jobs, attending trade schools, or entering the military rather than…

Evolution of Mat Strength from the Paleoarchean to the Modern: A Record of Evolving Microbial Communities?

NASA Astrophysics Data System (ADS)

Tice, M.; Pope, M.; Thornton, D.

2011-12-01

Fossil microbial mats, i.e. surface-attached communities of benthic microorganisms, form the most extensive record of life on Earth. Qualitatively changing mat morphologies from 3.43-0.56-billion-years-ago may reflect the evolution of microorganism communities or changing environmental conditions. However, mat morphogenesis is not well understood or easily quantifiable, making interpretation of the mat record difficult. We show that microbial mat cohesion increased from ~1 Pa to ~13 Pa at 2.7-billion-years-ago (Ga), and has remained high for most of the rest of Earth history. This initial increase may represent an early increase in the productivity of mat communities, a change in the composition of extracellular polymeric substances (EPS) produced by mat-formers, or a change in the composition of seawater affecting EPS strength. The appearance of early high-strength communities was coincident with the appearance of voids representing gas bubbles in the apices of conical stromatolites; together, these changes may record the emergence of productive mat communities dominated by oxygenic cyanobacteria. The earliest high-strength communities, like early bubble-forming conical stromatolites, grew in low-energy environments. The appearance of high-strength communities in shallow-water environments starting 2.63-2.52 Ga coincided with the appearance of the first barrier reef complexes. We hypothesize that the first oxygenic cyanobacteria were most competitive with anoxygenic phototrophs in diffusion-limited environments. As the cyanobacteria became more proficient at oxygenic photosynthesis, they eventually outcompeted anoxygenic phototrophs in higher-energy environments. Competition with higher strength seaweed and grazing by metazoans has displaced mat communities from essentially all modern high-energy niches.

MAT2B promotes adipogenesis by modulating SAMe levels and activating AKT/ERK pathway during porcine intramuscular preadipocyte differentiation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhao, Cunzhen; Chen, Xiaochang; Wu, Wenjing

Intramuscular fat (IMF) has been demonstrated as one of the crucial factors of livestock meat quality. The MAT2B protein with MAT2α catalyzes the formation of methyl donor S- adenosylmethionine (SAMe) to mediate cell metabolism including proliferation and apoptosis. However, the regulatory effect of MAT2B on IMF deposition is still unclear. In this study, the effect of MAT2B on adipogenesis and its potential mechanism during porcine intramuscular preadipocyte differentiation was studied. The results showed that overexpression of MAT2B promoted adipogenesis and significantly up-regulated the mRNA and protein levels of adipogenic marker genes including FASN, PPARγ and aP2, consistently, knockdown of MAT2Bmore » inhibited lipid accumulation and down-regulated the mRNA and protein levels of the above genes. Furthermore, flow cytometry and EdU-labeling assay indicated that MAT2B regulate adipogenesis was partly due to influence intracellular SAMe levels and further affect cell clonal expansion. Also, increased expression of MAT2B activated the phosphorylations of AKT and ERK1/2, whereas knockdown of MAT2B blocked AKT signaling and repressed the phosphorylation of ERK1/2. Moreover, the inhibitory effect of LY294002 (a specific PI3K inhibitor) on the activities of AKT and ERK1/2 was partially recovered by overexpression of MAT2B in porcine intramuscular adipocytes. Finally, Co-IP experiments showed that MAT2B can directly interact with AKT. Taken together, our findings suggested that MAT2B acted as a positive regulator through modifying SAMe levels as well as activating AKT/ERK signaling pathway to promote porcine intramuscular adipocyte differentiation. - Highlights: • MAT2B up-regulates the expression of adipogenic marker genes and promotes porcine intramuscular preadipocyte differentiation. • MAT2B influences intracellular SAMe levels and further affects cell clonal expansion. • MAT2B interacts with AKT and activates AKT/ERK signaling pathway.« less

Diversity, distribution and hydrocarbon biodegradation capabilities of microbial communities in oil-contaminated cyanobacterial mats from a constructed wetland.

PubMed

Abed, Raeid M M; Al-Kharusi, Samiha; Prigent, Stephane; Headley, Tom

2014-01-01

Various types of cyanobacterial mats were predominant in a wetland, constructed for the remediation of oil-polluted residual waters from an oil field in the desert of the south-eastern Arabian Peninsula, although such mats were rarely found in other wetland systems. There is scarce information on the bacterial diversity, spatial distribution and oil-biodegradation capabilities of freshwater wetland oil-polluted mats. Microbial community analysis by Automated Ribosomal Spacer Analysis (ARISA) showed that the different mats hosted distinct microbial communities. Average numbers of operational taxonomic units (OTUsARISA) were relatively lower in the mats with higher oil levels and the number of shared OTUsARISA between the mats was <60% in most cases. Multivariate analyses of fingerprinting profiles indicated that the bacterial communities in the wetland mats were influenced by oil and ammonia levels, but to a lesser extent by plant density. In addition to oil and ammonia, redundancy analysis (RDA) showed also a significant contribution of temperature, dissolved oxygen and sulfate concentration to the variations of the mats' microbial communities. Pyrosequencing yielded 282,706 reads with >90% of the sequences affiliated to Proteobacteria (41% of total sequences), Cyanobacteria (31%), Bacteriodetes (11.5%), Planctomycetes (7%) and Chloroflexi (3%). Known autotrophic (e.g. Rivularia) and heterotrophic (e.g. Azospira) nitrogen-fixing bacteria as well as purple sulfur and non-sulfur bacteria were frequently encountered in all mats. On the other hand, sequences of known sulfate-reducing bacteria (SRBs) were rarely found, indicating that SRBs in the wetland mats probably belong to yet-undescribed novel species. The wetland mats were able to degrade 53-100% of C12-C30 alkanes after 6 weeks of incubation under aerobic conditions. We conclude that oil and ammonia concentrations are the major key players in determining the spatial distribution of the wetland mats' microbial

The role of simulation in the development and flight test of the HiMAT vehicle

NASA Technical Reports Server (NTRS)

Evans, M. B.; Schilling, L. J.

1984-01-01

Real time simulations have been essential in the flight test program of the highly maneuverable aircraft technology (HiMAT) remotely piloted research vehicle at NASA Ames Research Center's Dryden Flight Research Facility. The HiMAT project makes extensive use of simulations in design, development, and qualification for flight, pilot training, and flight planning. Four distinct simulations, each with varying amounts of hardware in the loop, were developed for the HiMAT project. The use of simulations in detecting anomalous behavior of the flight software and hardware at the various stages of development, verification, and validation has been the key to flight qualification of the HiMAT vehicle.

Timescales of Growth Response of Microbial Mats to Environmental Change in an Ice-Covered Antarctic Lake

PubMed Central

Hawes, Ian; Sumner, Dawn Y.; Andersen, Dale T.; Jungblut, Anne D.; Mackey, Tyler J.

2013-01-01

Lake Vanda is a perennially ice-covered, closed-basin lake in the McMurdo Dry Valleys, Antarctica. Laminated photosynthetic microbial mats cover the floor of the lake from below the ice cover to >40 m depth. In recent decades, the water level of Lake Vanda has been rising, creating a “natural experiment” on development of mat communities on newly flooded substrates and the response of deeper mats to declining irradiance. Mats in recently flooded depths accumulate one lamina (~0.3 mm) per year and accrue ~0.18 µg chlorophyll-a cm−2 y−1. As they increase in thickness, vertical zonation becomes evident, with the upper 2-4 laminae forming an orange-brown zone, rich in myxoxanthophyll and dominated by intertwined Leptolyngbya trichomes. Below this, up to six phycobilin-rich green/pink-pigmented laminae form a subsurface zone, inhabited by Leptolyngbya, Oscillatoria and Phormidium morphotypes. Laminae continued to increase in thickness for several years after burial, and PAM fluorometry indicated photosynthetic potential in all pigmented laminae. At depths that have been submerged for >40 years, mats showed similar internal zonation and formed complex pinnacle structures that were only beginning to appear in shallower mats. Chlorophyll-a did not change over time and these mats appear to represent resource-limited “climax” communities. Acclimation of microbial mats to changing environmental conditions is a slow process, and our data show how legacy effects of past change persist into the modern community structure. PMID:24832656

Timescales of growth response of microbial mats to environmental change in an ice-covered antarctic lake.

PubMed

Hawes, Ian; Sumner, Dawn Y; Andersen, Dale T; Jungblut, Anne D; Mackey, Tyler J

2013-01-25

Lake Vanda is a perennially ice-covered, closed-basin lake in the McMurdo Dry Valleys, Antarctica. Laminated photosynthetic microbial mats cover the floor of the lake from below the ice cover to >40 m depth. In recent decades, the water level of Lake Vanda has been rising, creating a "natural experiment" on development of mat communities on newly flooded substrates and the response of deeper mats to declining irradiance. Mats in recently flooded depths accumulate one lamina (~0.3 mm) per year and accrue ~0.18 µg chlorophyll-a cm-2 y-1. As they increase in thickness, vertical zonation becomes evident, with the upper 2-4 laminae forming an orange-brown zone, rich in myxoxanthophyll and dominated by intertwined Leptolyngbya trichomes. Below this, up to six phycobilin-rich green/pink-pigmented laminae form a subsurface zone, inhabited by Leptolyngbya, Oscillatoria and Phormidium morphotypes. Laminae continued to increase in thickness for several years after burial, and PAM fluorometry indicated photosynthetic potential in all pigmented laminae. At depths that have been submerged for >40 years, mats showed similar internal zonation and formed complex pinnacle structures that were only beginning to appear in shallower mats. Chlorophyll-a did not change over time and these mats appear to represent resource-limited "climax" communities. Acclimation of microbial mats to changing environmental conditions is a slow process, and our data show how legacy effects of past change persist into the modern community structure.

4. Photographic copy of historic photograph. Jan.June 1948 OAMA. (Original ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

4. Photographic copy of historic photograph. Jan.-June 1948 OAMA. (Original print located at Ogden Air Logistics Center, Hill Air Force Base, Utah). Photographer unknown. - Hill Field, North of State Highway 193, East of Interstate 15, South of Davis-Weber Canal, West of Wherry Road, Layton, Davis County, UT

10. Photographic copy of historic photograph. Jan.June 1954 OAMA. (Original ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

10. Photographic copy of historic photograph. Jan.-June 1954 OAMA. (Original print located at Ogden Air Logistics Center, Hill Air Force Base, Utah). Photographer unknown. - Hill Field, North of State Highway 193, East of Interstate 15, South of Davis-Weber Canal, West of Wherry Road, Layton, Davis County, UT

7. Photographic copy of historic photograph. Jan.June 1951 OAMA. (Original ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

7. Photographic copy of historic photograph. Jan.-June 1951 OAMA. (Original print located at Ogden Air Logistics Center, Hill Air Force Base, Utah). Photographer unknown. - Hill Field, North of State Highway 193, East of Interstate 15, South of Davis-Weber Canal, West of Wherry Road, Layton, Davis County, UT

6. Photographic copy of historic photograph. Jan.June 1951 OAMA. (Original ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

6. Photographic copy of historic photograph. Jan.-June 1951 OAMA. (Original print located at Ogden Air Logistics Center, Hill Air Force Base, Utah). Photographer unknown. - Hill Field, North of State Highway 193, East of Interstate 15, South of Davis-Weber Canal, West of Wherry Road, Layton, Davis County, UT

Fabricating poly(1,8-octanediol citrate) elastomer based fibrous mats via electrospinning for soft tissue engineering scaffold.

PubMed

Zhu, Lei; Zhang, Yuanzheng; Ji, Yali

2017-06-01

Poly(1,8-octanediol citrate) (POC) is a recently developed biodegradable crosslinked elastomer that possesses good cytocompatibility and matchable mechanical properties to soft tissues. However, the thermosetting characteristic reveals a big challenge to manufacture its porous scaffold. Herein, POC elastomer was electrospun into fiber mat using poly(L-lactic acid) (PLLA) as a spinnable carrier. The obtained POC/PLLA fiber mats were characterized by scanning electron microscopy (SEM), dynamic mechanical analysis (DMA), uniaxial tensile test, static-water-contact-angle, thermal analysis, in vitro degradation and biocompatibility test. It was found that the fibrous structure could be formed so long as the POC pre-polymer's content was no more than 50 wt%. The presence of elastic POC component not only strengthened the fiber mats but also toughened the fiber mats. The hydrophilicity of 50/50 fiber mat significantly improved. In vitro degradation rate of POC based fiber mats was much faster than that of pure PLLA. Cyto- and histo-compatibility tests confirmed that the POC/PLLA fiber mats had good biocompatibility for potential applications in soft tissue engineering.

Molecular typing of uropathogenic E. coli strains by the ERIC-PCR method.

PubMed

Ardakani, Maryam Afkhami; Ranjbar, Reza

2016-04-01

Escherichia coli (E. coli) is the most common cause of urinary infections in hospitals. The aim of this study was to evaluate the ERIC-PCR method for molecular typing of uropathogenic E. coli strains isolated from hospitalized patients. In a cross sectional study, 98 E. coli samples were collected from urine samples taken from patients admitted to Baqiyatallah Hospital from June 2014 to January 2015. The disk agar diffusion method was used to determine antibiotic sensitivity. DNA proliferation based on repetitive intergenic consensus was used to classify the E. coli strains. The products of proliferation were electrophoresed on 1.5% agarose gel, and their dendrograms were drawn. The data were analyzed by online Insillico software. The method used in this research proliferated numerous bands (4-17 bands), ranging from 100 to 3000 base pairs. The detected strains were classified into six clusters (E1-E6) with 70% similarity between them. In this study, uropathogenic E. coli strains belonged to different genotypic clusters. It was found that ERIC-PCR had good differentiation power for molecular typing of uropathogenic E. coli strains isolated from the patients in the study.

Remembering Jan Svoboda: A Personal Reflection.

PubMed

Weiss, Robin A

2018-04-18

The Czech scientist Jan Svoboda was a pioneer of Rous sarcoma virus (RSV). In the 1960s, before the discovery of reverse transcriptase, he demonstrated the long-term persistence of the viral genome in non-productive mammalian cells, and he supported the DNA provirus hypothesis of Howard Temin. He showed how the virus can be rescued in the infectious form and elucidated the replication-competent nature of the Prague strain of RSV later used for the identification of the src oncogene. His studies straddled molecular oncology and virology, and he remained an active contributor to the field until his death last year. Throughout the 50 years that I was privileged to know Svoboda as my mentor and friend, I admired his depth of scientific inquiry and his steadfast integrity in the face of political oppression.

Microbial Mat Communities along an Oxygen Gradient in a Perennially Ice-Covered Antarctic Lake

PubMed Central

Hawes, Ian; Mackey, Tyler J.; Krusor, Megan; Doran, Peter T.; Sumner, Dawn Y.; Eisen, Jonathan A.; Hillman, Colin; Goroncy, Alexander K.

2015-01-01

Lake Fryxell is a perennially ice-covered lake in the McMurdo Dry Valleys, Antarctica, with a sharp oxycline in a water column that is density stabilized by a gradient in salt concentration. Dissolved oxygen falls from 20 mg liter−1 to undetectable over one vertical meter from 8.9- to 9.9-m depth. We provide the first description of the benthic mat community that falls within this oxygen gradient on the sloping floor of the lake, using a combination of micro- and macroscopic morphological descriptions, pigment analysis, and 16S rRNA gene bacterial community analysis. Our work focused on three macroscopic mat morphologies that were associated with different parts of the oxygen gradient: (i) “cuspate pinnacles” in the upper hyperoxic zone, which displayed complex topography and were dominated by phycoerythrin-rich cyanobacteria attributable to the genus Leptolyngbya and a diverse but sparse assemblage of pennate diatoms; (ii) a less topographically complex “ridge-pit” mat located immediately above the oxic-anoxic transition containing Leptolyngbya and an increasing abundance of diatoms; and (iii) flat prostrate mats in the upper anoxic zone, dominated by a green cyanobacterium phylogenetically identified as Phormidium pseudopriestleyi and a single diatom, Diadesmis contenta. Zonation of bacteria was by lake depth and by depth into individual mats. Deeper mats had higher abundances of bacteriochlorophylls and anoxygenic phototrophs, including Chlorobi and Chloroflexi. This suggests that microbial communities form assemblages specific to niche-like locations. Mat morphologies, underpinned by cyanobacterial and diatom composition, are the result of local habitat conditions likely defined by irradiance and oxygen and sulfide concentrations. PMID:26567300

Microbial Mat Communities along an Oxygen Gradient in a Perennially Ice-Covered Antarctic Lake.

PubMed

Jungblut, Anne D; Hawes, Ian; Mackey, Tyler J; Krusor, Megan; Doran, Peter T; Sumner, Dawn Y; Eisen, Jonathan A; Hillman, Colin; Goroncy, Alexander K

2016-01-15

Lake Fryxell is a perennially ice-covered lake in the McMurdo Dry Valleys, Antarctica, with a sharp oxycline in a water column that is density stabilized by a gradient in salt concentration. Dissolved oxygen falls from 20 mg liter(-1) to undetectable over one vertical meter from 8.9- to 9.9-m depth. We provide the first description of the benthic mat community that falls within this oxygen gradient on the sloping floor of the lake, using a combination of micro- and macroscopic morphological descriptions, pigment analysis, and 16S rRNA gene bacterial community analysis. Our work focused on three macroscopic mat morphologies that were associated with different parts of the oxygen gradient: (i) "cuspate pinnacles" in the upper hyperoxic zone, which displayed complex topography and were dominated by phycoerythrin-rich cyanobacteria attributable to the genus Leptolyngbya and a diverse but sparse assemblage of pennate diatoms; (ii) a less topographically complex "ridge-pit" mat located immediately above the oxic-anoxic transition containing Leptolyngbya and an increasing abundance of diatoms; and (iii) flat prostrate mats in the upper anoxic zone, dominated by a green cyanobacterium phylogenetically identified as Phormidium pseudopriestleyi and a single diatom, Diadesmis contenta. Zonation of bacteria was by lake depth and by depth into individual mats. Deeper mats had higher abundances of bacteriochlorophylls and anoxygenic phototrophs, including Chlorobi and Chloroflexi. This suggests that microbial communities form assemblages specific to niche-like locations. Mat morphologies, underpinned by cyanobacterial and diatom composition, are the result of local habitat conditions likely defined by irradiance and oxygen and sulfide concentrations. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

Compound-specific Isotope Analysis of Cyanobacterial Pure cultures and Microbial Mats: Effects of Photorespiration?

NASA Technical Reports Server (NTRS)

Jahnke, L. L.; Summons, R. E.

2006-01-01

Microbial mats are considered modern homologs of Precambrian stromatolites. The carbon isotopic compositions of organic matter and biomarker lipids provide clues to the depositional environments of ancient mat ecosystems. As the source of primary carbon fixation for over two billion years, an understanding of cyanobacterial lipid biosynthesis, associated isotopic discriminations, and the influence of physiological factors on growth and isotope expression is essential to help us compare modern microbial ecosystems to their ancient counterparts. Here, we report on the effects of photorespiration (PR) on the isotopic composition of cyanobacteria and biomarker lipids, and on potential PR effects associated with the composition of various microbial mats. The high light, high O2 and limiting CO2 conditions often present at the surface of microbial mats are known to support PR in cyanobacteria. The oxygenase function of ribulose bisphosphate carboxylase/oxygenase can result in photoexcretion of glycolate and subsequent degration by heterotrophic bacteria. We have found evidence which supports an isotopic depletion (increased apparent E) scaled to O2 level associated with growth of Phormidium luridum at low CO2 concentrations (less than 0.04%). Similar to previous studies, isotopic differences between biomass and lipid biomarkers, and between lipid classes were positively correlated with overall fractionation, and should provide a means of estimating the influence of PR on overall isotopic composition of microbial mats. Several examples of microbial mats growing in the hydrothermal waters of Yellowstone National Park and the hypersaline marine evaporation ponds at Guerrero Negro, Baja Sur Mexico will be compared with a view to PR as a possible explanation of the relatively heavy C-isotope composition of hypersaline mats.

Accuracy of Jump-Mat Systems for Measuring Jump Height.

PubMed

Pueo, Basilio; Lipinska, Patrycja; Jiménez-Olmedo, José M; Zmijewski, Piotr; Hopkins, Will G

2017-08-01

Vertical-jump tests are commonly used to evaluate lower-limb power of athletes and nonathletes. Several types of equipment are available for this purpose. To compare the error of measurement of 2 jump-mat systems (Chronojump-Boscosystem and Globus Ergo Tester) with that of a motion-capture system as a criterion and to determine the modifying effect of foot length on jump height. Thirty-one young adult men alternated 4 countermovement jumps with 4 squat jumps. Mean jump height and standard deviations representing technical error of measurement arising from each device and variability arising from the subjects themselves were estimated with a novel mixed model and evaluated via standardization and magnitude-based inference. The jump-mat systems produced nearly identical measures of jump height (differences in means and in technical errors of measurement ≤1 mm). Countermovement and squat-jump height were both 13.6 cm higher with motion capture (90% confidence limits ±0.3 cm), but this very large difference was reduced to small unclear differences when adjusted to a foot length of zero. Variability in countermovement and squat-jump height arising from the subjects was small (1.1 and 1.5 cm, respectively, 90% confidence limits ±0.3 cm); technical error of motion capture was similar in magnitude (1.7 and 1.6 cm, ±0.3 and ±0.4 cm), and that of the jump mats was similar or smaller (1.2 and 0.3 cm, ±0.5 and ±0.9 cm). The jump-mat systems provide trustworthy measurements for monitoring changes in jump height. Foot length can explain the substantially higher jump height observed with motion capture.

Rapid spectrofluorometric screening of poly-hydroxyalkanoate-producing bacteria from microbial mats.

PubMed

Berlanga, Mercedes; Montero, M T; Fernández-Borrell, Jordi; Guerrero, Ricardo

2006-06-01

Microbial mat ecosystems are characterized by both seasonal and diel fluctuations in several physicochemical variables, so that resident microorganisms must frequently adapt to the changing conditions of their environment. It has been pointed out that, under stress conditions, bacterial cells with higher contents of poly-hydroxyalkanoates (PHA) survive longer than those with lower PHA content. In the present study, PHA-producing strains from Ebro Delta microbial mats were selected using the Nile red dying technique and the relative accumulation of PHA was monitored during further laboratory cultivation. The number of heterotrophic isolates in trypticase soy agar (TSA) was ca. 107 colony-forming units/g microbial mat. Of these, 100 randomly chosen colonies were replicated on mineral salt agar limited in nitrogen, and Nile red was added to the medium to detect PHA. Orange fluorescence, produced upon binding of the dye to polymer granules in the cell, was detected in approximately 10% of the replicated heterotrophic isolates. The kinetics of PHA accumulation in Pseudomonas putida, and P. oleovorans were compared with those of several of the environmental isolates spectrofluorometry. PHA accumulation, measured as relative fluorescence intensity, resulted in a steady-state concentration after 48 h of incubation in all strains assayed. At 72 h, the maximum fluorescence intensity of each strain incubated with glucose and fructose was usually similar. MAT-28 strain accumulated more PHA than the other isolates. The results show that data obtained from environmental isolates can highly improve studies based on modeling-simulation programs, and that microbial mats constitute an excellent source for the isolation of PHA-producing strains with industrial applications.

Full-Scale Evaluation of DuraDeck (registered trademark) and MegaDeck (trademark) Matting Systems

DTIC Science & Technology

2013-07-01

plates studded with threaded bolts were placed ERDC/GSL TR-13-27 10 underneath two pre-drilled corners of the panel. The plates were positioned so...metal plates studded with threaded ERDC/GSL TR-13-27 4 Figure 1. DuraDeck® mat panel, top surface. Figure 2. DuraDeck® mat panel, bottom surface...ERDC/GSL TR-13-27 5 bolts , as shown in Figure 3, underneath the mat corners and then installing special connector nuts from the top surface

CCP Astronaut Eric Boe, GOES-S Prepared for Launch

NASA Image and Video Library

2018-02-28

NASA astronaut Eric Boe, one of four astronauts working with the agency’s Commercial Crew Program, had the opportunity to check out the Crew Access Tower at Space Launch Complex 41 (SLC-41) Wednesday with a United Launch Alliance Atlas V on the pad. Boe, along with launch operations engineers from NASA, Boeing, and ULA, climbed the launch pad tower to evaluate lighting and spotlights after dark. The survey helped ensure crew members will have acceptable visibility as they prepare to launch aboard Boeing’s Starliner spacecraft on the Crew Flight Test to the International Space Station targeted for later this year.

Widespread anatoxin-a detection in benthic cyanobacterial mats throughout a river network

PubMed Central

Kudela, Raphael M.; Power, Mary E.

2018-01-01

Benthic algae fuel summer food webs in many sunlit rivers, and are hotspots for primary and secondary production and biogeochemical cycling. Concerningly, riverine benthic algal assemblages can become dominated by toxic cyanobacteria, threatening water quality and public health. In the Eel River in Northern California, over a dozen dog deaths have been attributed to cyanotoxin poisonings since 2000. During the summers of 2013–2015, we documented spatial and temporal patterns of cyanotoxin concentrations in the watershed, showing widespread distribution of anatoxin-a in benthic cyanobacterial mats. Solid phase adsorption toxin tracking (SPATT) samplers were deployed weekly to record dissolved microcystin and anatoxin-a levels at 10 sites throughout the watershed, and 187 Anabaena-dominated or Phormidium-dominated cyanobacterial mat samples were collected from 27 locations to measure intracellular anatoxin-a (ATX) and microcystins (MCY). Anatoxin-a levels were higher than microcystin for both SPATT (mean MCY = 0.8 and ATX = 4.8 ng g resin-1 day-1) and cyanobacterial mat samples (mean MCY = 0.074 and ATX = 1.89 μg g-1 DW). Of the benthic mats sampled, 58.9% had detectable anatoxin-a (max = 70.93 μg g-1 DW), while 37.6% had detectable microcystins (max = 2.29 μg g-1 DW). SPATT cyanotoxin levels peaked in mid-summer in warm mainstem reaches of the watershed. This is one of the first documentations of widespread anatoxin-a occurrence in benthic cyanobacterial mats in a North American watershed. PMID:29775481

Kodak T-Mat G film in rotational panoramic radiography.

PubMed

Ponce, A Z; McDavid, W D; Lundeen, R C; Morris, C R

1986-06-01

Panoramic radiographs were taken of a tissue-equivalent phantom to evaluate T-Mat G and Ortho G films in combination with rare earth screens. The radiographs were compared to radiographs made with high-speed calcium tungstate screens and Kodak XRP film. The reduction in the amount of radiation necessary for the use of rare earth screens (50% to 70%) was accomplished by lowering the mA and adding filtration. All evaluated films were diagnostically acceptable. There was a marked preference of the T-Mat radiographs over the Ortho G radiographs and a slight preference over radiographs made with the standard calcium-tungstate screen-film system.

Simulated Carbon Cycling in a Model Microbial Mat.

NASA Astrophysics Data System (ADS)

Decker, K. L.; Potter, C. S.

2006-12-01

We present here the novel addition of detailed organic carbon cycling to our model of a hypersaline microbial mat ecosystem. This ecosystem model, MBGC (Microbial BioGeoChemistry), simulates carbon fixation through oxygenic and anoxygenic photosynthesis, and the release of C and electrons for microbial heterotrophs via cyanobacterial exudates and also via a pool of dead cells. Previously in MBGC, the organic portion of the carbon cycle was simplified into a black-box rate of accumulation of simple and complex organic compounds based on photosynthesis and mortality rates. We will discuss the novel inclusion of fermentation as a source of carbon and electrons for use in methanogenesis and sulfate reduction, and the influence of photorespiration on labile carbon exudation rates in cyanobacteria. We will also discuss the modeling of decomposition of dead cells and the ultimate release of inorganic carbon. The detailed modeling of organic carbon cycling is important to the accurate representation of inorganic carbon flux through the mat, as well as to accurate representation of growth models of the heterotrophs under different environmental conditions. Because the model ecosystem is an analog of ancient microbial mats that had huge impacts on the atmosphere of early earth, this MBGC can be useful as a biological component to either early earth models or models of other planets that potentially harbor life.

Enhancing the Mechanical Properties of Electrospun Nanofiber Mats through Controllable Welding at the Cross Points.

PubMed

Li, Haoxuan; Zhu, Chunlei; Xue, Jiajia; Ke, Qinfei; Xia, Younan

2017-05-01

This communication describes a simple and effective method for welding electrospun nanofibers at the cross points to enhance the mechanical properties of their nonwoven mats. The welding is achieved by placing a nonwoven mat of the nanofibers in a capped vial with the vapor of a proper solvent. For polycaprolactone (PCL) nanofibers, the solvent is dichloromethane (DCM). The welding can be managed in a controllable fashion by simply varying the partial pressure of DCM and/or the exposure time. Relative to the pristine nanofiber mat, the mechanical strength of the welded PCL nanofiber mat can be increased by as much as 200%. Meanwhile, such a treatment does not cause any major structural changes, including morphology, fiber diameter, and pore size. This study provides a generic method for improving the mechanical properties of nonwoven nanofiber mats, holding great potential in various applications. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

NASA Planetary Science Division's Instrument Development Programs, PICASSO and MatISSE

NASA Technical Reports Server (NTRS)

Gaier, James R.

2016-01-01

The Planetary Science Division (PSD) has combined several legacy instrument development programs into just two. The Planetary Instrument Concepts Advancing Solar System Observations (PICASSO) program funds the development of low TRL instruments and components. The Maturation of Instruments for Solar System Observations (MatISSE) program funds the development of instruments in the mid-TRL range. The strategy of PSD instrument development is to develop instruments from PICASSO to MatISSE to proposing for mission development.

Bibliometric Characteristics of Articles on Key Competences Indexed in ERIC from 1990 to 2013

ERIC Educational Resources Information Center

Buscà Donet, Francesc; Ambròs Pallares, Alba; Burset Burillo, Sílvia

2017-01-01

This paper analyses the bibliometric characteristics of 616 journal articles on key competences indexed in ERIC in a 23-year-period following documentary analysis. This observation method allowed us to highlight key elements like the population, educational level, topics, etc. to focus whether this literature contributes towards implementing…

Halloysite nanotube-based electrospun ceramic nanofibre mat: a novel support for zeolite membranes

PubMed Central

Chen, Zhuwen; Zeng, Jiaying; Lv, Dong; Gao, Jinqiang; Zhang, Jian; Bai, Shan; Li, Ruili; Wu, Jingshen

2016-01-01

Some key parameters of supports such as porosity, pore shape and size are of great importance for fabrication and performance of zeolite membranes. In this study, we fabricated millimetre-thick, self-standing electrospun ceramic nanofibre mats and employed them as a novel support for zeolite membranes. The nanofibre mats were prepared by electrospinning a halloysite nanotubes/polyvinyl pyrrolidone composite followed by a programmed sintering process. The interwoven nanofibre mats possess up to 80% porosity, narrow pore size distribution, low pore tortuosity and highly interconnected pore structure. Compared with the commercial α-Al2O3 supports prepared by powder compaction and sintering, the halloysite nanotube-based mats (HNMs) show higher flux, better adsorption of zeolite seeds, adhesion of zeolite membranes and lower Al leaching. Four types of zeolite membranes supported on HNMs have been successfully synthesized with either in situ crystallization or a secondary growth method, demonstrating good universality of HNMs for supporting zeolite membranes. PMID:28083098

Controls on O2 Production in Cyanobacterial Mats and Implications for Earth's Oxygenation

NASA Astrophysics Data System (ADS)

Dick, Gregory J.; Grim, Sharon L.; Klatt, Judith M.

2018-05-01

Cyanobacterial mats are widely assumed to have been globally significant hot spots of biogeochemistry and evolution during the Archean and Proterozoic, but little is known about their quantitative contributions to global primary productivity or Earth's oxygenation. Modern systems show that mat biogeochemistry is the outcome of concerted activities and intimate interactions between various microbial metabolisms. Emerging knowledge of the regulation of oxygenic and sulfide-driven anoxygenic photosynthesis by versatile cyanobacteria, and their interactions with sulfur-oxidizing bacteria and sulfate-reducing bacteria, highlights how ecological and geochemical processes can control O2 production in cyanobacterial mats in unexpected ways. This review explores such biological controls on O2 production. We argue that the intertwined effects of light availability, redox geochemistry, regulation and competition of microbial metabolisms, and biogeochemical feedbacks result in emergent properties of cyanobacterial mat communities that are all critical yet largely overlooked mechanisms to potentially explain the protracted nature of Earth's oxygenation.

Halloysite nanotube-based electrospun ceramic nanofibre mat: a novel support for zeolite membranes

NASA Astrophysics Data System (ADS)

Chen, Zhuwen; Zeng, Jiaying; Lv, Dong; Gao, Jinqiang; Zhang, Jian; Bai, Shan; Li, Ruili; Hong, Mei; Wu, Jingshen

2016-12-01

Some key parameters of supports such as porosity, pore shape and size are of great importance for fabrication and performance of zeolite membranes. In this study, we fabricated millimetre-thick, self-standing electrospun ceramic nanofibre mats and employed them as a novel support for zeolite membranes. The nanofibre mats were prepared by electrospinning a halloysite nanotubes/polyvinyl pyrrolidone composite followed by a programmed sintering process. The interwoven nanofibre mats possess up to 80% porosity, narrow pore size distribution, low pore tortuosity and highly interconnected pore structure. Compared with the commercial α-Al2O3 supports prepared by powder compaction and sintering, the halloysite nanotube-based mats (HNMs) show higher flux, better adsorption of zeolite seeds, adhesion of zeolite membranes and lower Al leaching. Four types of zeolite membranes supported on HNMs have been successfully synthesized with either in situ crystallization or a secondary growth method, demonstrating good universality of HNMs for supporting zeolite membranes.

Assembly and Succession of Iron Oxide Microbial Mat Communities in Acidic Geothermal Springs

PubMed Central

Beam, Jacob P.; Bernstein, Hans C.; Jay, Zackary J.; Kozubal, Mark A.; Jennings, Ryan deM.; Tringe, Susannah G.; Inskeep, William P.

2016-01-01

Biomineralized ferric oxide microbial mats are ubiquitous features on Earth, are common in hot springs of Yellowstone National Park (YNP, WY, USA), and form due to direct interaction between microbial and physicochemical processes. The overall goal of this study was to determine the contribution of different community members to the assembly and succession of acidic high-temperature Fe(III)-oxide mat ecosystems. Spatial and temporal changes in Fe(III)-oxide accretion and the abundance of relevant community members were monitored over 70 days using sterile glass microscope slides incubated in the outflow channels of two acidic geothermal springs (pH = 3–3.5; temperature = 68–75°C) in YNP. Hydrogenobaculum spp. were the most abundant taxon identified during early successional stages (4–40 days), and have been shown to oxidize arsenite, sulfide, and hydrogen coupled to oxygen reduction. Iron-oxidizing populations of Metallosphaera yellowstonensis were detected within 4 days, and reached steady-state levels within 14–30 days, corresponding to visible Fe(III)-oxide accretion. Heterotrophic archaea colonized near 30 days, and emerged as the dominant functional guild after 70 days and in mature Fe(III)-oxide mats (1–2 cm thick). First-order rate constants of Fe(III)-oxide accretion ranged from 0.046 to 0.05 day−1, and in situ microelectrode measurements showed that the oxidation of Fe(II) is limited by the diffusion of O2 into the Fe(III)-oxide mat. The formation of microterracettes also implicated O2 as a major variable controlling microbial growth and subsequent mat morphology. The assembly and succession of Fe(III)-oxide mat communities follows a repeatable pattern of colonization by lithoautotrophic organisms, and the subsequent growth of diverse organoheterotrophs. The unique geochemical signatures and micromorphology of extant biomineralized Fe(III)-oxide mats are also useful for understanding other Fe(II)-oxidizing systems. PMID:26913020

Das US-Fachinformationssystem ERIC und die Entwicklung eines Fachinformationssystems Bildung in der Bundesrepublik Deutschland (The American Subject Information System ERIC and the Development of an Information System on Education in the German Federal Republic).

ERIC Educational Resources Information Center

Nachrichten fur Dokumentation, 1982

1982-01-01

In order to further develop West German information services for education, it is suggested that the ERIC structural model--a coordinating central office and a network of clearinghouses--be developed as a continuation of the existing "Dokumentationsring Padagogik" (DOPAED) documentation service. (16 references) (EJS)

Structure and function of natural sulphide-oxidizing microbial mats under dynamic input of light and chemical energy

PubMed Central

Klatt, Judith M; Meyer, Steffi; Häusler, Stefan; Macalady, Jennifer L; de Beer, Dirk; Polerecky, Lubos

2016-01-01

We studied the interaction between phototrophic and chemolithoautotrophic sulphide-oxidizing microorganisms in natural microbial mats forming in sulphidic streams. The structure of these mats varied between two end-members: one characterized by a layer dominated by large sulphur-oxidizing bacteria (SOB; mostly Beggiatoa-like) on top of a cyanobacterial layer (B/C mats) and the other with an inverted structure (C/B mats). C/B mats formed where the availability of oxygen from the water column was limited (<5 μm). Aerobic chemolithotrophic activity of the SOB depended entirely on oxygen produced locally by cyanobacteria during high light conditions. In contrast, B/C mats formed at locations where oxygen in the water column was comparatively abundant (>45 μM) and continuously present. Here SOB were independent of the photosynthetic activity of cyanobacteria and outcompeted the cyanobacteria in the uppermost layer of the mat where energy sources for both functional groups were concentrated. Outcompetition of photosynthetic microbes in the presence of light was facilitated by the decoupling of aerobic chemolithotrophy and oxygenic phototrophy. Remarkably, the B/C mats conserved much less energy than the C/B mats, although similar amounts of light and chemical energy were available. Thus ecosystems do not necessarily develop towards optimal energy usage. Our data suggest that, when two independent sources of energy are available, the structure and activity of microbial communities is primarily determined by the continuous rather than the intermittent energy source, even if the time-integrated energy flux of the intermittent energy source is greater. PMID:26405833

Magnetoacoustic Tomography with Magnetic Induction (MAT-MI) for Imaging Electrical Conductivity of Biological Tissue: A Tutorial Review

PubMed Central

Li, Xu; Yu, Kai; He, Bin

2016-01-01

Magnetoacoustic tomography with magnetic induction (MAT-MI) is a noninvasive imaging method developed to map electrical conductivity of biological tissue with millimeter level spatial resolution. In MAT-MI, a time-varying magnetic stimulation is applied to induce eddy current inside the conductive tissue sample. With the existence of a static magnetic field, the Lorentz force acting on the induced eddy current drives mechanical vibrations producing detectable ultrasound signals. These ultrasound signals can then be acquired to reconstruct a map related to the sample’s electrical conductivity contrast. This work reviews fundamental ideas of MAT-MI and major techniques developed in these years. First, the physical mechanisms underlying MAT-MI imaging are described including the magnetic induction and Lorentz force induced acoustic wave propagation. Second, experimental setups and various imaging strategies for MAT-MI are reviewed and compared together with the corresponding experimental results. In addition, as a recently developed reverse mode of MAT-MI, magneto-acousto-electrical tomography with magnetic induction (MAET-MI) is briefly reviewed in terms of its theory and experimental studies. Finally, we give our opinions on existing challenges and future directions for MAT-MI research. With all the reported and future technical advancement, MAT-MI has the potential to become an important noninvasive modality for electrical conductivity imaging of biological tissue. PMID:27542088

Reliability, agreement, and validity of digital weighing scale with MatScan in limb load measurement.

PubMed

Kumar, Senthil N S; Omar, Baharudin; Htwe, Ohnmar; Joseph, Leonard H; Krishnan, Jagannathan; Jafarzedah Esfehani, Ali; Min, Lee L

2014-01-01

Limb loading measurements serve as an objective evaluation of asymmetrical weight bearing in the lower limb. Digital weighing scales (DWSs) could be used in clinical settings for measurement of static limb loading. However, ambiguity exists whether limb loading measurements of DWSs are comparable with a standard tool such as MatScan. A cross-sectional study composed of 33 nondisabled participants was conducted to investigate the reliability, agreement, and validity of DWSs with MatScan in static standing. Amounts of weight distribution and plantar pressure on the individual lower limb were measured using two DWSs (A, B) and MatScan during eyes open (EO) and eyes closed (EC) conditions. The results showed that intra- and interrater reliability (3, 1) were excellent (0.94-0.97) within and between DWS A and B. Bland-Altman plot revealed good agreement between DWS and MatScan in EO and EC conditions. The area under the receiver operating characteristic curve was significant and identified as 0.68 (p = 0.01). The measurements obtained with DWSs are valid and in agreement with MatScan measurements. Hence, DWSs could be used interchangeably with MatScan and could provide clinicians an objective measurement of limb loading suitable for clinical settings.

Molecular Diversity of Cyanobacteria Inhabiting Coniform Structures and Surrounding Mat in a Yellowstone Hot Spring

NASA Astrophysics Data System (ADS)

Lau, Evan; Nash, Cody Z.; Vogler, Detlev R.; Cullings, K. W.

2005-02-01

Lithified coniform structures are common within cyanobacterial mats in Yellowstone National Park hot springs. It is unknown whether these structures and the mats from which they develop are inhabited by the same cyanobacterial populations. Denaturing gradient gel electrophoresis and sequencing and phylogenetic analysis of 16S rDNA was used to determine whether (1) three different morphological types of lithified coniform structures are inhabited by different cyanobacterial species, (2) these species are partitioned along a vertical gradient of these structures, and (3) lithified and non-lithified sections of mat are inhabited by different cyanobacterial species. Our results, based on multiple samplings, indicate that the cyanobacterial community compositions in the three lithified morphological types were identical and lacked any vertical differentiation. However, lithified and non-lithified portions of the same mat were inhabited by distinct and different populations of cyanobacteria. Cyanobacteria inhabiting lithified structures included at least one undefined Oscillatorialean taxon, which may represent the dominant cyanobacteria genus in lithified coniform stromatolites, Phormidium, three Synechococcus-like species, and two unknown cyanobacterial taxa. In contrast, the surrounding mats contained four closely related Synechococcus-like species. Our results indicate that the distribution of lithified coniform stromatolites may be dependent on the presence of one or more microorganisms, which are phylogenetically different from those inhabiting surrounding non-lithified mats.

Modifying landing mat material properties may decrease peak contact forces but increase forefoot forces in gymnastics landings.

PubMed

Mills, Chris; Yeadon, Maurice R; Pain, Matthew T G

2010-09-01

This study investigated how changes in the material properties of a landing mat could minimise ground reaction forces (GRF) and internal loading on a gymnast during landing. A multi-layer model of a gymnastics competition landing mat and a subject-specific seven-link wobbling mass model of a gymnast were developed to address this aim. Landing mat properties (stiffness and damping) were optimised using a Simplex algorithm to minimise GRF and internal loading. The optimisation of the landing mat parameters was characterised by minimal changes to the mat's stiffness (<0.5%) but increased damping (272%) compared to the competition landing mat. Changes to the landing mat resulted in reduced peak vertical and horizontal GRF and reduced bone bending moments in the shank and thigh compared to a matching simulation. Peak bone bending moments within the thigh and shank were reduced by 6% from 321.5 Nm to 302.5Nm and GRF by 12% from 8626 N to 7552 N when compared to a matching simulation. The reduction in these forces may help to reduce the risk of bone fracture injury associated with a single landing and reduce the risk of a chronic injury such as a stress fracture.

A Process for the Creation of T-MATS Propulsion System Models from NPSS data

NASA Technical Reports Server (NTRS)

Chapman, Jeffryes W.; Lavelle, Thomas M.; Litt, Jonathan S.; Guo, Ten-Huei

2014-01-01

A modular thermodynamic simulation package called the Toolbox for the Modeling and Analysis of Thermodynamic Systems (T-MATS) has been developed for the creation of dynamic simulations. The T-MATS software is designed as a plug-in for Simulink (Math Works, Inc.) and allows a developer to create system simulations of thermodynamic plants (such as gas turbines) and controllers in a single tool. Creation of such simulations can be accomplished by matching data from actual systems, or by matching data from steady state models and inserting appropriate dynamics, such as the rotor and actuator dynamics for an aircraft engine. This paper summarizes the process for creating T-MATS turbo-machinery simulations using data and input files obtained from a steady state model created in the Numerical Propulsion System Simulation (NPSS). The NPSS is a thermodynamic simulation environment that is commonly used for steady state gas turbine performance analysis. Completion of all the steps involved in the process results in a good match between T-MATS and NPSS at several steady state operating points. Additionally, the T-MATS model extended to run dynamically provides the possibility of simulating and evaluating closed loop responses.

A Process for the Creation of T-MATS Propulsion System Models from NPSS Data

NASA Technical Reports Server (NTRS)

Chapman, Jeffryes W.; Lavelle, Thomas M.; Litt, Jonathan S.; Guo, Ten-Huei

2014-01-01

A modular thermodynamic simulation package called the Toolbox for the Modeling and Analysis of Thermodynamic Systems (T-MATS) has been developed for the creation of dynamic simulations. The T-MATS software is designed as a plug-in for Simulink(Trademark) and allows a developer to create system simulations of thermodynamic plants (such as gas turbines) and controllers in a single tool. Creation of such simulations can be accomplished by matching data from actual systems, or by matching data from steady state models and inserting appropriate dynamics, such as the rotor and actuator dynamics for an aircraft engine. This paper summarizes the process for creating T-MATS turbo-machinery simulations using data and input files obtained from a steady state model created in the Numerical Propulsion System Simulation (NPSS). The NPSS is a thermodynamic simulation environment that is commonly used for steady state gas turbine performance analysis. Completion of all the steps involved in the process results in a good match between T-MATS and NPSS at several steady state operating points. Additionally, the T-MATS model extended to run dynamically provides the possibility of simulating and evaluating closed loop responses.

A Process for the Creation of T-MATS Propulsion System Models from NPSS Data

NASA Technical Reports Server (NTRS)

Chapman, Jeffryes W.; Lavelle, Thomas M.; Litt, Jonathan S.; Guo, Ten-Huei

2014-01-01

A modular thermodynamic simulation package called the Toolbox for the Modeling and Analysis of Thermodynamic Systems (T-MATS) has been developed for the creation of dynamic simulations. The T-MATS software is designed as a plug-in for Simulink(Registered TradeMark) and allows a developer to create system simulations of thermodynamic plants (such as gas turbines) and controllers in a single tool. Creation of such simulations can be accomplished by matching data from actual systems, or by matching data from steady state models and inserting appropriate dynamics, such as the rotor and actuator dynamics for an aircraft engine. This paper summarizes the process for creating T-MATS turbo-machinery simulations using data and input files obtained from a steady state model created in the Numerical Propulsion System Simulation (NPSS). The NPSS is a thermodynamic simulation environment that is commonly used for steady state gas turbine performance analysis. Completion of all the steps involved in the process results in a good match between T-MATS and NPSS at several steady state operating points. Additionally, the T-MATS model extended to run dynamically provides the possibility of simulating and evaluating closed loop responses.

Microbial mats: an ecological niche for fungi

PubMed Central

Cantrell, Sharon A.; Duval-Pérez, Lisabeth

2013-01-01

Fungi were documented in tropical hypersaline microbial mats and their role in the degradation of complex carbohydrates (exopolymeric substance – EPS) was explored. Fungal diversity is higher during the wet season with Acremonium, Aspergillus, Cladosporium, and Penicillium among the more common genera. Diversity is also higher in the oxic layer and in young and transient mats. Enrichments with xanthan (a model EPS) show that without antibiotics (full community) degradation is faster than enrichments with antibacterial (fungal community) and antifungal (bacterial community) agents, suggesting that degradation is performed by a consortium of organisms (bacteria and fungi). The combined evidence from all experiments indicates that bacteria carried out approximately two-third of the xanthan degradation. The pattern of degradation is similar between seasons and layers but degradation is faster in enrichments from the wet season. The research suggests that fungi thrive in these hypersaline consortia and may participate in the carbon cycle through the degradation of complex carbohydrates. PMID:23577004

Full-Scale Instrumented Testing and Analysis of Matting Systems for Airfield Parking Ramps and Taxiways

DTIC Science & Technology

2007-12-01

system can only be precisely determined by examining all the materials used in the mat, their structure , orientation, dimensions, etc. and determining...ER D C/ G SL T R- 07 -3 3 Full-Scale Instrumented Testing and Analysis of Matting Systems for Airfield Parking Ramps and Taxiways Chad...ERDC/GSL TR-07-33 December 2007 Full-Scale Instrumented Testing and Analysis of Matting Systems for Airfield Parking Ramps and Taxiways Chad A

Resources on Law-Related Education: Documents and Journal Articles in ERIC. Yearbook No. 3.

ERIC Educational Resources Information Center

Healy, Langdon T., Ed.; Vontz, Thomas S., Ed.

This ERIC resource is a guide to the array of law-related education (LRE) resources available to teachers. The annotated bibliography offers resources for essential knowledge of the law, innovative teaching methods, and guides to national LRE programs. Included in this collection are abstracts of LRE documents and journal articles, arranged…

Wetting and Coalescence of Drops of Self-Healing Agents on Electrospun Nanofiber Mats.

PubMed

An, Seongpil; Kim, Yong Il; Lee, Min Wook; Yarin, Alexander L; Yoon, Sam S

2017-10-10

Here we study experimentally the behavior of liquid healing agents released in vascular core-shell nanofiber mats used in self-healing engineered materials. It is shown that wettability-driven spreading of liquid drops is accompanied by the imbibition into the nanofiber matrix, and its laws deviate from those known for spreading on an intact surface. We also explore coalescence of the released drops on nanofiber mats, in particular, coalescence of drops of resin monomer and cure important for self-healing. The coalescence process is also affected by the imbibition into the pores of an underlying nanofiber mat. A theoretical model is developed to account for the imbibition effect on drop coalescence.

A Cyanine Dye Encapsulated Porous Fibrous Mat for Naked-Eye Ammonia Sensing.

PubMed

Ji, Chendong; Ma, Lijing; Yin, Meizhen; Yang, Wantai; Pan, Kai

2016-08-19

Electrospun ultrathin fiber-based sensors are desirable because of their practicality and sensitivity. Ammonia-detection systems are in high demand in different areas, including the industrial and agricultural fields. However, current technologies rely on large and complex instruments that restrict their actual utilization. Herein, we report a flexible naked-eye ammonia sensor, the polylactic acid-cyanine (PLA-Cy) fibrous mat, which was fabricated by blending a carboxyl-functionalized cyanine dye (D1) into electospun PLA porous fibers. The sensing mat was shown to undergo a naked-eye-detectable color change from white to blue upon exposure to ammonia vapor. The mat showed high selectivity to ammonia gas with a detection limit of 3.3 ppm. Aggregated D1 was first encapsulated by PLA and was then ionized by NH3 . These mechanisms were examined by photophysical studies and scanning electron microscopy. The aggregation-deaggregation process of D1 in the PLA-Cy fibrous mat led to the color change. This work provides a facile method for the naked-eye detection of ammonia and a novel strategy for the use of organic dyes in ammonia sensing. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Remembering Jan Svoboda: A Personal Reflection

PubMed Central

Weiss, Robin A.

2018-01-01

The Czech scientist Jan Svoboda was a pioneer of Rous sarcoma virus (RSV). In the 1960s, before the discovery of reverse transcriptase, he demonstrated the long-term persistence of the viral genome in non-productive mammalian cells, and he supported the DNA provirus hypothesis of Howard Temin. He showed how the virus can be rescued in the infectious form and elucidated the replication-competent nature of the Prague strain of RSV later used for the identification of the src oncogene. His studies straddled molecular oncology and virology, and he remained an active contributor to the field until his death last year. Throughout the 50 years that I was privileged to know Svoboda as my mentor and friend, I admired his depth of scientific inquiry and his steadfast integrity in the face of political oppression. PMID:29670049

Dinitrogen-fixing cyanobacteria in microbial mats of two shallow coral reef ecosystems.

PubMed

Charpy, Loic; Palinska, Katarzyna A; Casareto, Beatriz; Langlade, Marie José; Suzuki, Yoshimi; Abed, Raeid M M; Golubic, Stjepko

2010-01-01

Dinitrogen-fixing organisms in cyanobacterial mats were studied in two shallow coral reef ecosystems: La Reunion Island, southwestern Indian Ocean, Sesoko (Okinawa) Island, and northwestern Pacific Ocean. Rapidly expanding benthic miniblooms, frequently dominated by a single cyanobacterial taxon, were identified by microscopy and molecular tools. In addition, nitrogenase activity by these blooms was measured in situ. Dinitrogen fixation and its contribution to mat primary production were calculated using (15)N(2) and (13)C methods. Dinitrogen-fixing cyanobacteria from mats in La Reunion and Sesoko showed few differences in taxonomic composition. Anabaena sp. among heterocystous and Hydrocoleum majus and Symploca hydnoides among nonheterocystous cyanobacteria occurred in microbial mats of both sites. Oscillatoria bonnemaisonii and Leptolyngbya spp. occurred only in La Reunion, whereas Hydrocoleum coccineum dominated in Sesoko. Other mats dominated by Hydrocoleum lyngbyaceum, Phormidium laysanense, and Trichocoleus tenerrimus occurred at lower frequencies. The 24-h nitrogenase activity, as measured by acetylene reduction, varied between 11 and 324 nmoles C(2)H(2) reduced microg(-1) Chl a. The highest values were achieved by heterocystous Anabaena sp. performed mostly during the day. Highest values for nonheterocystous cyanobacteria were achieved by H. coccineum mostly during the night. Daily nitrogen fixation varied from nine (Leptolyngbya) to 238 nmoles N(2) microg(-1) Chl day(-1) (H. coccineum). Primary production rates ranged from 1,321 (S. hydnoides) to 9,933 nmoles C microg(-1) Chl day(-1) (H. coccineum). Dinitrogen fixation satisfied between 5% and 21% of the nitrogen required for primary production.

Total mercury and methyl-mercury contents and accumulation in polar microbial mats.

PubMed

Camacho, Antonio; Rochera, Carlos; Hennebelle, Raphaëlle; Ferrari, Christophe; Quesada, Antonio

2015-03-15

Although polar regions are considered isolated and pristine areas, the organisms that inhabit these zones are exposed to global pollution. Heavy metals, such as mercury, are global pollutants and can reach almost any location on Earth. Mercury may come from natural, volcanic or geological sources, or result from anthropogenic sources, in particular industrial or mining activities. In this study, we have investigated one of the most prominent biological non-marine communities in both polar regions, microbial mats, in terms of their Hg and methyl-mercury (MeHg) concentrations and accumulation capacities. The main hypotheses posed argued on the importance of different factors, and to test them, we have measured Hg concentrations in microbial mats that were collected from 6 locations in different ecological situations. For this purpose, the direct anthropogenic impacts, volcanic influences, proximity to the seashore, latitudinal gradients and C contents were investigated. Our results show that, other than the direct anthropogenic influence, none of the other hypotheses alone satisfactorily explains the Hg content in microbial mats. In contrast, the MeHg contents were noticeably different between the investigated locations, with a higher proportion of MeHg on the McMurdo Ice Shelf (Antarctica) and a lower proportion on Ward Hunt Island (High Arctic). Furthermore, our results from in situ experiments indicated that the microbial mats from South Shetland Islands could quickly accumulate (48 h) Hg when Hg dissolved salts were supplied. Over short-term periods, these mats do not transform Hg into MeHg under field conditions. Copyright © 2014 Elsevier B.V. All rights reserved.

Diatom-driven recolonization of microbial mat-dominated siliciclastic tidal flat sediments.

PubMed

Pan, Jerónimo; Cuadrado, Diana G; Bournod, Constanza N

2017-10-01

Modern microbial mats and biofilms play a paramount role in sediment biostabilization. When sporadic storms affect tidal flats of Bahía Blanca Estuary, the underlying siliciclastic sediment is exposed by physical disruption of the mat, and in a few weeks' lapse, a microbial community re-establishes. With the objective of studying colonization patterns and the ecological succession of microorganisms at the scale of these erosional structures, these were experimentally made and their biological recolonization followed for 8 weeks, with replication in winter and spring. Motile pennate diatoms led the initial colonization following two distinct patterns: a dominance by Cylindrotheca closterium in winter and by naviculoid and nitzschioid diatoms in spring. During the first 7 days, cell numbers increased 2- to 17-fold. Cell densities further increased exhibiting sigmoidal community growth, reaching 2.9-8.9 × 106 cells cm-3 maxima around day 30; centric diatoms maintained low densities throughout. In 56 days after removal of the original mat, filamentous cyanobacteria that dominate mature mats did not establish a significant biomass, leading to the rejection of the hypothesis that cyanobacteria would drive the colonization. The observed dominance of pennate diatoms is attributed to extrinsic factors determined by tidal flooding, and intrinsic ones, e.g. motility, nutrient affinity and high growth rate. © FEMS 2017. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

[Jan Pilecki (1821-1878) and achievements his Druskieninkai].

PubMed

Kierzek, Andrzej; Kuciel-Lewandowska, Jadwiga; Pozowski, Andrzej; Borowicz-Paprocka, Małgorzata

2012-01-01

The history of development of health resort Druskieniki basing on Adam Wrzosek, an eminent Polish historian of medicine pointed out. The beauty and advantages of this health resort is depicted widely. The living and professional achievements of Jan Pilecki (1821-1878), an eminent physician of health resort, his significance for development and of Druskieninkai are presented in more detail. The medical indications and contraindications in Druskieniki basing on his own experiences have been reported. Pilecki was a author of many medical publications in Polish medical magazines. His papers contained interested medical observations and description of social life and entertainments in this health resort.

Characterization and Modification of Electrospun Fiber Mats for Use in Composite Proton Exchange Membranes

NASA Astrophysics Data System (ADS)

Mannarino, Matthew Marchand

Electrostatic fiber formation, or electrospinning, offers a particularly simple and robust method to create polymeric nanofibers of various sizes and morphologies. In electrospinning, a viscoelastic fluid is charged so that a liquid jet is ejected from the surface of the fluid (typically in the form of a drop supplied by a needle or spinneret) and collected on a grounded plate, creating a nonwoven fiber mat. Modification of the diameter of the fibers as well as the porosity, specific surface area, and mechanical properties of the mat allows one to tailor electrospun mats for specific applications. Despite the widespread and rapidly growing use of electrospinning in the fabrication of novel nanomaterials, there are no simple, universal methods of predicting, a priori, the properties of electrospun fibers from knowledge of the polymer solution properties and electrospinning operating conditions alone. Changing a single fluid or processing parameter can affect the jet and fiber formation through several mechanisms. For example, using a different solvent can change several properties of the electrospinning fluid, such as the dielectric constant, conductivity, surface tension, and solute-solvent interaction. The work in this thesis seeks to develop a simple relation for predicting terminal jet diameter during electrospinning, which accounts for solution viscoelasticity as well as solution conductivity and operating parameters that can be easily measured and controlled. The mechanical and tribological properties of electrospun fiber mats are of paramount importance to their utility as components in a variety of applications. Although some mechanical properties of these mats have been investigated previously, reports of their tribological properties are essentially nonexistent. In this thesis, electrospun nanofiber mats of poly(trimethyl hexamethylene terephthalamide) (PA 6(3)T) and poly(hexamethylene adipamide) (PA 6,6) are characterized mechanically and tribologically

The Use of ERIC Tapes in Scandinavia, Searching With Thesaurus Terms in Natural Language.

ERIC Educational Resources Information Center

Tell, Bjorn V.; And Others

Since February 1971 the Royal Institute of Technology, Stockholm, has been running the ERIC data base mainly for SDI purposes. The implementation of the data base into the generalized search system, ABACUS, is described. One hundred and fifty-eight users received SDI service at present, 99 from governmental and educational institutions, 23 from…

Engineering and Scientific Applications: Using MatLab(Registered Trademark) for Data Processing and Visualization

NASA Technical Reports Server (NTRS)

Sen, Syamal K.; Shaykhian, Gholam Ali

2011-01-01

MatLab(R) (MATrix LABoratory) is a numerical computation and simulation tool that is used by thousands Scientists and Engineers in many cou ntries. MatLab does purely numerical calculations, which can be used as a glorified calculator or interpreter programming language; its re al strength is in matrix manipulations. Computer algebra functionalities are achieved within the MatLab environment using "symbolic" toolbo x. This feature is similar to computer algebra programs, provided by Maple or Mathematica to calculate with mathematical equations using s ymbolic operations. MatLab in its interpreter programming language fo rm (command interface) is similar with well known programming languag es such as C/C++, support data structures and cell arrays to define c lasses in object oriented programming. As such, MatLab is equipped with most ofthe essential constructs of a higher programming language. M atLab is packaged with an editor and debugging functionality useful t o perform analysis of large MatLab programs and find errors. We belie ve there are many ways to approach real-world problems; prescribed methods to ensure foregoing solutions are incorporated in design and ana lysis of data processing and visualization can benefit engineers and scientist in gaining wider insight in actual implementation of their perspective experiments. This presentation will focus on data processing and visualizations aspects of engineering and scientific applicati ons. Specifically, it will discuss methods and techniques to perform intermediate-level data processing covering engineering and scientifi c problems. MatLab programming techniques including reading various data files formats to produce customized publication-quality graphics, importing engineering and/or scientific data, organizing data in tabu lar format, exporting data to be used by other software programs such as Microsoft Excel, data presentation and visualization will be discussed. The presentation will emphasize creating

Comparative protein modeling of methionine S-adenosyltransferase (MAT) enzyme from Mycobacterium tuberculosis: a potential target for antituberculosis drug discovery.

PubMed

Khedkar, Santosh A; Malde, Alpeshkumar K; Coutinho, Evans C

2005-01-01

Mycobacterium tuberculosis (Mtb) is a successful pathogen that overcomes the numerous challenges presented by the immune system of the host. In the last 40 years few anti-TB drugs have been developed, while the drug-resistance problem is increasing; there is thus a pressing need to develop new anti-TB drugs active against both the acute and chronic growth phases of the mycobacterium. Methionine S-adenosyltransferase (MAT) is an enzyme involved in the synthesis of S-adenosylmethionine (SAM), a methyl donor essential for mycolipid biosynthesis. As an anti-TB drug target, Mtb-MAT has been well validated. A homology model of MAT has been constructed using the X-ray structures of E. coli MAT (PDB code: 1MXA) and rat MAT (PDB code: 1QM4) as templates, by comparative protein modeling principles. The resulting model has the correct stereochemistry as gauged from the Ramachandran plot and good three-dimensional (3D) structure compatibility as assessed by the Profiles-3D score. The structurally and functionally important residues (active site) of Mtb-MAT have been identified using the E. coli and rat MAT crystal structures and the reported point mutation data. The homology model conserves the topological and active site features of the MAT family of proteins. The differences in the molecular electrostatic potentials (MEP) of Mtb and human MAT provide evidences that selective and specific Mtb-MAT inhibitors can be designed using the homology model, by the structure-based drug design approaches.

Gro2mat: a package to efficiently read gromacs output in MATLAB.

PubMed

Dien, Hung; Deane, Charlotte M; Knapp, Bernhard

2014-07-30

Molecular dynamics (MD) simulations are a state-of-the-art computational method used to investigate molecular interactions at atomic scale. Interaction processes out of experimental reach can be monitored using MD software, such as Gromacs. Here, we present the gro2mat package that allows fast and easy access to Gromacs output files from Matlab. Gro2mat enables direct parsing of the most common Gromacs output formats including the binary xtc-format. No openly available Matlab parser currently exists for this format. The xtc reader is orders of magnitudes faster than other available pdb/ascii workarounds. Gro2mat is especially useful for scientists with an interest in quick prototyping of new mathematical and statistical approaches for Gromacs trajectory analyses. © 2014 Wiley Periodicals, Inc. Copyright © 2014 Wiley Periodicals, Inc.

Preparation and adsorption behavior of aminated electrospun polyacrylonitrile nanofiber mats for heavy metal ion removal.

PubMed

Kampalanonwat, Pimolpun; Supaphol, Pitt

2010-12-01

Polyacrylonitrile (PAN) nanofiber mats were prepared by electrospinning and they were further modified to contain amidino diethylenediamine chelating groups on their surface via heterogeneous reaction with diethylenetriamine (DETA). The obtained aminated PAN (APAN) nanofiber mats were evaluated for their chelating property with four types of metal ions, namely Cu(II), Ag(I), Fe(II), and Pb(II) ions. The amounts of the metal ions adsorbed onto the APAN nanofiber mats were influenced by the initial pH and the initial concentration of the metal ion solutions. Increasing the contact time also resulted in a monotonous increase in the adsorbed amounts of the metal ions, which finally reached equilibria at about 10 h for Cu(II) ions and about 5 h for Ag(I), Fe(II), and Pb(II) ions. The maximal adsorption capacities of the metal ions on the APAN nanofiber mats, as calculated from the Langmuir model, were 150.6, 155.5, 116.5, and 60.6 mg g(-1), respectively. Lastly, the spent APAN nanofiber mats could be facilely regenerated with a hydrochloric acid (HCl) aqueous solution.

Thermophilic methanogenesis in a hot-spring algal-bacterial mat (71 to 30/sup 0/C)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ward, D.M.

1978-06-01

Algal-bacterial mats which grow in the effluent channels of alkaline hot springs provided an environment suitable for studying natural thermophilic methane-producing bacteria. Methane was rapidly produced in cores taken from the mat and appeared to be an end product of decomposition of the algal-bacterial organic matter. Formaldehyde prevented production of methane. Initial methanogenic rate was lower and methanogenesis became exponential when samples were permitted to cool before laboratory incubation. Methanogenesis occurred and methanogenic bateria were present over a range of 68 to 30/sup 0/C, with optimum methanogenesis near 45/sup 0/C. The temperature distribution of methanogenesis in the mat is discussedmore » relative to published results on standing crop, primary production, and decomposition in the thermal gradient. The depth distribution of methanogenesis was similar to that of freshwater sediments, with a zone of intense methanogenesis near the mat surface. Methanogenesis in deeper mat layers was very low or undetectable despite large numbers of viable methanogenic bacteria and could not be stimulated by addition of anoxic source water, sulfide, or a macronutrient solution.« less

Nitrogen Fixation (Acetylene Reduction) Associated with Duckweed (Lemnaceae) Mats

PubMed Central

Zuberer, D. A.

1982-01-01

Duckweed (Lemnaceae) mats in Texas and Florida were investigated, using the acetylene reduction assay, to determine whether nitrogen fixation occurred in these floating aquatic macrophyte communities. N2-fixing microorganisms were enumerated by plating or most-probable-number techniques, using appropriate N-free media. Results of the investigations indicated that substantial N2-fixation (C2H2) was associated with duckweed mats in Texas and Florida. Acetylene reduction values ranged from 1 to 18 μmol of C2H4 g (dry weight)−1 day−1 for samples incubated aerobically in light. Dark N2 fixation was always two- to fivefold lower. 3-(3,4-Dichlorophenyl)-1,1-dimethylurea (7 to 10 μM) reduced acetylene reduction to levels intermediate between light and dark incubation. Acetylene reduction was generally greatest for samples incubated anaerobically in the light. It was estimated that 15 to 20% of the N requirement of the duckweed could be supplied through biological nitrogen fixation. N2-fixing heterotrophic bacteria (105 cells g [wet weight]−1 and cyanobacteria (105 propagules g [wet weight]−1 were associated with the duckweed mats. Azotobacter sp. was not detected in these investigations. One diazotrophic isolate was classified as Klebsiella. PMID:16345992

Distinctive fungal and bacterial communities are associated with mats formed by ectomycorrhizal fungi

Treesearch

Laurel A. Kluber; Jane E. Smith; David D. Myrold

2011-01-01

The distinct rhizomorphic mats formed by ectomycorrhizal Piloderma fungi are common features of the organic soil horizons of coniferous forests of the Pacific Northwest. These mats have been found to cover 25-40% of the forest floor in some Douglas-fir stands, and are associated with physical and biochemical properties that distinguish them from...

Resistance and resilience of floating mat fens in interior Alaska following airboat disturbance

Treesearch

Amy Zacheis; Kate Doran

2009-01-01

The floating mat fens of the Tanana Flats in interior Alaska are productive wetlands near the urban center of Fairbanks. Airboat traffic has created a network of trails through the floating vegetation mats. We established protected areas along established trails, which allowed for measurement of plant community resistance to airboat traffic and resilience following...

Community Structure of Lithotrophically-Driven Hydrothermal Microbial Mats from the Mariana Arc and Back-Arc

PubMed Central

Hager, Kevin W.; Fullerton, Heather; Butterfield, David A.; Moyer, Craig L.

2017-01-01

The Mariana region exhibits a rich array of hydrothermal venting conditions in a complex geological setting, which provides a natural laboratory to study the influence of local environmental conditions on microbial community structure as well as large-scale patterns in microbial biogeography. We used high-throughput amplicon sequencing of the bacterial small subunit (SSU) rRNA gene from 22 microbial mats collected from four hydrothermally active locations along the Mariana Arc and back-arc to explore the structure of lithotrophically-based microbial mat communities. The vent effluent was classified as iron- or sulfur-rich corresponding with two distinct community types, dominated by either Zetaproteobacteria or Epsilonproteobacteria, respectively. The Zetaproteobacterial-based communities had the highest richness and diversity, which supports the hypothesis that Zetaproteobacteria function as ecosystem engineers creating a physical habitat within a chemical environment promoting enhanced microbial diversity. Gammaproteobacteria were also high in abundance within the iron-dominated mats and some likely contribute to primary production. In addition, we also compare sampling scale, showing that bulk sampling of microbial mats yields higher diversity than micro-scale sampling. We present a comprehensive analysis and offer new insights into the community structure and diversity of lithotrophically-driven microbial mats from a hydrothermal region associated with high microbial biodiversity. Our study indicates an important functional role of for the Zetaproteobacteria altering the mat habitat and enhancing community interactions and complexity. PMID:28970817

Vitamin E-loaded silk fibroin nanofibrous mats fabricated by green process for skin care application.

PubMed

Sheng, Xiaoyue; Fan, Linpeng; He, Chuanglong; Zhang, Kuihua; Mo, Xiumei; Wang, Hongsheng

2013-05-01

In the present study, we reported fabrication and skin benefit of a novel vitamin E (VE)-loaded silk fibroin (SF) nanofibrous mats. RRR-α-Tocopherol polyethylene glycol 1000 succinate (VE TPGS), a water-soluble derivative of VE, was incorporated into SF nanofiber successfully by aqua solution electrospinning for the first time. Morphology of the composite nanofibers changed with the different amount of VE TPGS: a ribbon-like shape for lower loading dose of VE TPGS, while a round shape for higher loading dose (more than 4% (wt/wt) based on the weight of SF). After treated with 75% (v/v) ethanol vapor, the composite nanofibrous mats showed an excellent water-resistant ability. In vitro study disclosed a sustained release behavior of VE TPGS disassociated from the nanofibrous mats. The mouse skin fibroblasts (L929 cells) cultured on the VE-loaded SF nanofibrous mats spread and proliferated much better than on cover slips. Moreover, the incorporation of VE TPGS was found strengthening the ability of SF nanofibrous mats on protecting the cells against oxidation stress induced by tert-butyl hydroperoxide. Our data presented impressive skin benefits of this VE-loaded SF nanofibrous mats, suggesting a promising applicative potential of this novel product on personal skin care, tissue regeneration and other related area. Copyright © 2013 Elsevier B.V. All rights reserved.

Benthic cyanobacterial mats in the high arctic: multi-layer structure and fluorescence responses to osmotic stress.

PubMed

Lionard, Marie; Péquin, Bérangère; Lovejoy, Connie; Vincent, Warwick F

2012-01-01

Cyanobacterial mats are often a major biological component of extreme aquatic ecosystems, and in polar lakes and streams they may account for the dominant fraction of total ecosystem biomass and productivity. In this study we examined the vertical structure and physiology of Arctic microbial mats relative to the question of how these communities may respond to ongoing environmental change. The mats were sampled from Ward Hunt Lake (83°5.297'N, 74°9.985'W) at the northern coast of Arctic Canada, and were composed of three visibly distinct layers. Microsensor profiling showed that there were strong gradients in oxygen within each layer, with an overall decrease from 100% saturation at the mat surface to 0%, at the bottom, accompanied by an increase of 0.6 pH units down the profile. Gene clone libraries (16S rRNA) revealed the presence of Oscillatorian sequences throughout the mat, while Nostoc related species dominated the two upper layers, and Nostocales and Synechococcales sequences were common in the bottom layer. High performance liquid chromatography analyses showed a parallel gradient in pigments, from high concentrations of UV-screening scytonemin in the upper layer to increasing zeaxanthin and myxoxanthin in the bottom layer, and an overall shift from photoprotective to photosynthetic carotenoids down the profile. Climate change is likely to be accompanied by lake level fluctuations and evaporative concentration of salts, and thus increased osmotic stress of the littoral mat communities. To assess the cellular capacity to tolerate increasing osmolarity on physiology and cell membrane integrity, mat sections were exposed to a gradient of increasing salinities, and PAM measurements of in vivo chlorophyll fluorescence were made to assess changes in maximum quantum yield. The results showed that the mats were tolerant of up to a 46-fold increase in salinity. These features imply that cyanobacterial mats are resilient to ongoing climate change, and that in the

A study on tinea gladiatorum in young wrestlers and dermatophyte contamination of wrestling mats from Sari, Iran

PubMed Central

Hedayati, Mohammad T; Afshar, Parvaneh; Shokohi, Tahereh; Aghili, Reza

2007-01-01

Objective To study the prevalence of tinea gladiatorum among young wrestlers and dermatophyte contamination of wrestling mats from Sari city, the capital of Mazandaran, a northern province of Iran. Design 324 wrestlers (aged 9–20 years) from 7 active clubs in Sari city were examined, and skin scrapings were obtained from 135 wrestlers suspected of having tinea gladiatorum. The scraped skin samples were evaluated with potassium hydroxide. Pleated carpet sterile fragments (5×5 cm) were used for to survey of wrestling mat contamination. Sabouraud's dextrose agar with and without chloramphenicole and cyclohexamide was used to culture scrapings and wrestling mat samples. The dermatophytes were identified by routine laboratory techniques. Results Our study showed that of the 324 wrestlers, 65 (20.1%) had tinea gladiatorum. Most lesions were on the trunk and head. All the wrestling mat samples were positive for dermatophytes. Trichophyton tonsurans was isolated from all the scrapings and wrestling mat samples. Conclusion Considering that several colonies of T tonsurans were isolated from all the wrestling mats and from wrestlers with tinea gladiatorum (as the only dermatophyte species) we think that the contamination of wrestling mats with T tonsurans has a crucial role in the injection of wrestlers. PMID:17138633

HazMatID (trademark) Replacement Project

DTIC Science & Technology

2013-05-09

replacement for the Smiths Detection HazMatIDTM on the 886H allowance standard, a search of Fourier transform infrared spectroscopy ( FTIR ) instruments was...uses FTIR spectroscopy. It has the capability to identify chemical warfare agents, explosives , toxic industrial chemicals, narcotics, and...uses FTIR technology , providing a wider spectral coverage and higher spectral resolution. Findings: As I operated the Mobile-IR, I found it to

Mulching effects of plant fiber and plant fiber-polyester mats combined with fertilizer on loblslly pine seedlings

Treesearch

James D. Haywood; John A. Youngquist

1991-01-01

In this preliminary study, several mattings, combined with and without fertilizer application, were tested around newly planted loblolly, pine (Pinus taeda L.) seedlings. After 9 months in the field, jute- polyester and jute mats had similar survival rates relitive to controls, but hemlock-po1yvester mats had depressed survival when used in...

Frontiers in Laser Cooling, Single-Molecule Biophysics, and Energy Science: A Talk from Eric Cornell

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cornell, Eric

2008-08-30

Eric Cornell presents a talk at Frontiers in Laser Cooling, Single-Molecule Biophysics and Energy Science, a scientific symposium honoring Steve Chu, director of Lawrence Berkeley National Laboratory and recipient of the 1997 Nobel Prize in Physics. The symposium was held August 30, 2008 in Berkeley.

Frontiers in Laser Cooling, Single-Molecule Biophysics, and Energy Science: A Talk from Eric Cornell

ScienceCinema

Cornell, Eric

2018-02-05

Eric Cornell presents a talk at Frontiers in Laser Cooling, Single-Molecule Biophysics and Energy Science, a scientific symposium honoring Steve Chu, director of Lawrence Berkeley National Laboratory and recipient of the 1997 Nobel Prize in Physics. The symposium was held August 30, 2008 in Berkeley.

Electrospun PVA/Bentonite Nanocomposites Mats for Drug Delivery

PubMed Central

Ferrández-Rives, Mariola; Gómez Ribelles, José Luis

2017-01-01

Electrospun mats and films of polyvinyl alcohol (PVA) hydrogel are produced for drug delivery. To provide mechanical consistency to the gel a reinforcement by nanoclays is introduced in the polymer matrix. Four different suspensions of nanoparticles in the polymer solution are prepared in an adequate solvent. These suspensions are subjected to an electrospinning process to produce the nanofiber mat, while films are produced by casting. The influence of the process parameters over the nanofibers microstructure is analyzed by scanning electron microscopy (SEM). The effectiveness of nanoclay encapsulation in the nanocomposites is tested by a thermogravimetric analysis. A crosslinking reaction in solution is carried out to prevent the dissolution of the nanocomposites in aqueous media. A model protein (bovine serum albumin, BSA) is absorbed in the nanocomposites to characterize the release kinetics in phosphate-buffered saline (PBS). PMID:29261123

The epsomitic phototrophic microbial mat of Hot Lake, Washington: community structural responses to seasonal cycling

PubMed Central

Lindemann, Stephen R.; Moran, James J.; Stegen, James C.; Renslow, Ryan S.; Hutchison, Janine R.; Cole, Jessica K.; Dohnalkova, Alice C.; Tremblay, Julien; Singh, Kanwar; Malfatti, Stephanie A.; Chen, Feng; Tringe, Susannah G.; Beyenal, Haluk; Fredrickson, James K.

2013-01-01

Phototrophic microbial mats are compact ecosystems composed of highly interactive organisms in which energy and element cycling take place over millimeter-to-centimeter-scale distances. Although microbial mats are common in hypersaline environments, they have not been extensively characterized in systems dominated by divalent ions. Hot Lake is a meromictic, epsomitic lake that occupies a small, endorheic basin in north-central Washington. The lake harbors a benthic, phototrophic mat that assembles each spring, disassembles each fall, and is subject to greater than tenfold variation in salinity (primarily Mg2+ and SO2−4) and irradiation over the annual cycle. We examined spatiotemporal variation in the mat community at five time points throughout the annual cycle with respect to prevailing physicochemical parameters by amplicon sequencing of the V4 region of the 16S rRNA gene coupled to near-full-length 16S RNA clone sequences. The composition of these microbial communities was relatively stable over the seasonal cycle and included dominant populations of Cyanobacteria, primarily a group IV cyanobacterium (Leptolyngbya), and Alphaproteobacteria (specifically, members of Rhodobacteraceae and Geminicoccus). Members of Gammaproteobacteria (e.g., Thioalkalivibrio and Halochromatium) and Deltaproteobacteria (e.g., Desulfofustis) that are likely to be involved in sulfur cycling peaked in summer and declined significantly by mid-fall, mirroring larger trends in mat community richness and evenness. Phylogenetic turnover analysis of abundant phylotypes employing environmental metadata suggests that seasonal shifts in light variability exert a dominant influence on the composition of Hot Lake microbial mat communities. The seasonal development and organization of these structured microbial mats provide opportunities for analysis of the temporal and physical dynamics that feed back to community function. PMID:24312082

The Epsomitic Phototrophic Microbial Mat of Hot Lake, Washington. Community Structural Responses to Seasonal Cycling

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lindemann, Stephen R.; Moran, James J.; Stegen, James C.

2013-11-13

Phototrophic microbial mats are compact ecosystems composed of highly interactive organisms in which energy and element cycling take place over millimeter-to-centimeter-scale distances. Although microbial mats are common in hypersaline environments, they have not been extensively characterized in systems dominated by divalent ions. Hot Lake is a meromictic, epsomitic lake that occupies a small, endorheic basin in north-central Washington. The lake harbors a benthic, phototrophic mat that assembles each spring, disassembles each fall, and is subject to greater than tenfold variation in salinity (primarily Mg 2+ and SO 2 -4) and irradiation over the annual cycle. We examined spatiotemporal variation inmore » the mat community at five time points throughout the annual cycle with respect to prevailing physicochemical parameters by amplicon sequencing of the V4 region of the 16S rRNA gene coupled to near-full-length 16S RNA clone sequences. The composition of these microbial communities was relatively stable over the seasonal cycle and included dominant populations of Cyanobacteria, primarily a group IV cyanobacterium (Leptolyngbya), and Alphaproteobacteria (specifically, members of Rhodobacteraceae and Geminicoccus). Members of Gammaproteobacteria (e.g., Thioalkalivibrio and Halochromatium) and Deltaproteobacteria (e.g., Desulfofustis) that are likely to be involved in sulfur cycling peaked in summer and declined significantly by mid-fall, mirroring larger trends in mat community richness and evenness. Phylogenetic turnover analysis of abundant phylotypes employing environmental metadata suggests that seasonal shifts in light variability exert a dominant influence on the composition of Hot Lake microbial mat communities. The seasonal development and organization of these structured microbial mats provide opportunities for analysis of the temporal and physical dynamics that feed back to community function.« less

Thermally Altered Silurian Cyanobacterial Mats: A Key to Earth's Oldest Fossils

NASA Astrophysics Data System (ADS)

Kazmierczak, Józef; Kremer, Barbara

2009-10-01

Diagenetic changes in thermally altered cyanobacterial mats from early Silurian black radiolarian cherts of southwestern Poland (Bardzkie Montains, Sudetes) have been studied. These early diagenetically silicified mats are composed of variously degraded remains of benthic microbes that resemble some modern chroococcalean and pleurocapsalean cyanobacteria. Two modes of degradational processes have been recognized in the studied mats: (i) early postmortem biodegradation and (ii) late diagenetic thermal or thermobaric degradation. The latter led to partial transformation of the fossilized organic remnants of cyanobacterial sheaths and capsules, which resulted in the formation of objects morphologically distant from the original microbiota but preserved features that allow for their identification as bona fide biogenic structures. Some of these thermally generated Silurian fossils are highly similar to the controversial microfossil-like carbonaceous structures described from the Early Archean Apex Chert of Australia. This similarity opens a promising way for credible recognition of remnants of cyanobacteria and similar microbiota in other thermally metamorphosed Archean sedimentary rocks

ISSR, ERIC and RAPD techniques to detect genetic diversity in the aphid pathogen Pandora neoaphidis.

PubMed

Tymon, Anna M; Pell, Judith K

2005-03-01

The entomopathogenic fungus Pandora neoaphidis is an important natural enemy of aphids. ISSR, ERIC (Enterobacterial Repetitive Intergenic Consensus) and RAPD PCR-based DNA fingerprint analyses were undertaken to study intra-specific variation amongst 30 isolates of P. neoaphidis worldwide, together with six closely related species of Entomophthorales. All methods yielded scorable binary characters, and distance matrices were constructed from both individual and combined data sets. Neighbour-joining was used to construct consensus phylogenetic trees which showed that although P. neoaphidis isolates were highly polymorphic they separated into a monophyletic group compared with the other Entomophthorales tested. Three distinct subclades were found, with UK isolates occupying two of these. No specific correlation with aphid host species was established for any of the isolates apart from those in one cluster which contained isolates obtained from nettle aphid, Microlophium carnosum. ERIC, ISSR and RAPD analysis allowed the rapid genetic characterisation and differentiation of isolates with the generation of potential isolate- and cluster specific-diagnostic DNA markers.

The Eggøyan eruption in 1732, Jan Mayen; an emerging ankaramitic surtseyjan type eruption

NASA Astrophysics Data System (ADS)

Gjerlxw, E.; Hoskuldsson, A.; Pedersen, R. B.; Thorseth, I. H.

2011-12-01

Jan Mayen is a volcanic island situated at 71°N and 8°W. The Island is build up of two main edifices, Sør Jan and Nord Jan (Beerenberg). Volcanic activity on the island is little known, and however at least 4 eruptions are documented at the island since early 18th century. An expedition to the island in summer 2011 reveals that first of these eruptions formed the tuffcone Eggøyan in 1732 AD. The Eggøyan tuffcone is situated at the north east foot of Beerenberg volcano, about 2.5 km from the coastline marked by Valberget. The tuffcone is about 1.5 km in diameter and emerges from about 35 m depth to reach the altitude of at least 217 m above sea level. Pre Eggøyan Lava flows on the sandy coast west of the edifice are covered by up to 1.6 m of ash some 3 km from the vent. These lava flows have been suggested to be formed in the 1732 eruption and the 1818 eruption of Jan Mayen. However, they are covered with the Eggøyan tephra and thus considerable older. Volcanic tephra from the Eggøyan eruption forms the uppermost tephra layer on the Eastern flanks of Beerenberg. Contemporary description of the 1732 eruption, tell of violent explosive eruption at the east side of Beerenberg observed by German whalers for 28 hours, while sailing past the island in May that year. A Dutch wailer group arriving to the island in June that year, report fine ash covering the island in such a way they sink up to mid leg into it. Our study this summer shows that the only eruption these descriptions can report to are the Eggøyan eruption, dating it precisely to the spring 1732. The eruptive products are made up of frothy glass and ol, cpx and opx crystals, which characterize the flank eruptions of Beerenberg. In this presentation we shall present first results of intense fragmentation of deep gas rich ankaramitic magma from the Jan Mayen are and its interaction with seawater in shallow coastal settings.

Information Technology and the Informed Citizen: New Challenges for Government and Libraries. ERIC Digest.

ERIC Educational Resources Information Center

White, Charles S.

Arguing that the foundation of a free civilization is an informed citizenry, this ERIC digest discusses the new challenges faced by the government and libraries in the wake of the Information Age. As electronic technology has accelerated the production and transmission of information, it has become more difficult for the average citizen to access,…

Methane-Oxidizing Bacteria Shunt Carbon to Microbial Mats at a Marine Hydrocarbon Seep

DOE Office of Scientific and Technical Information (OSTI.GOV)

Paul, Blair G.; Ding, Haibing; Bagby, Sarah C.

The marine subsurface is a reservoir of the greenhouse gas methane. While microorganisms living in water column and seafloor ecosystems are known to be a major sink limiting net methane transport from the marine subsurface to the atmosphere, few studies have assessed the flow of methane-derived carbon through the benthic mat communities that line the seafloor on the continental shelf where methane is emitted. We analyzed the abundance and isotope composition of fatty acids in microbial mats grown in the shallow Coal Oil Point seep field off Santa Barbara, CA, USA, where seep gas is a mixture of methane andmore » CO 2. We further used stable isotope probing (SIP) to track methane incorporation into mat biomass. We found evidence that multiple allochthonous substrates supported the rich growth of these mats, with notable contributions from bacterial methanotrophs and sulfur-oxidizers as well as eukaryotic phototrophs. Fatty acids characteristic of methanotrophs were shown to be abundant and 13C-enriched in SIP samples, and DNA-SIP identified members of the methanotrophic family Methylococcaceae as major 13CH 4 consumers. Members of Sulfuricurvaceae, Sulfurospirillaceae, and Sulfurovumaceae are implicated in fixation of seep CO 2. The mats’ autotrophs support a diverse assemblage of co-occurring bacteria and protozoa, with Methylophaga as key consumers of methane-derived organic matter. This study identifies the taxa contributing to the flow of seep-derived carbon through microbial mat biomass, revealing the bacterial and eukaryotic diversity of these remarkable ecosystems.« less

Methane-Oxidizing Bacteria Shunt Carbon to Microbial Mats at a Marine Hydrocarbon Seep

DOE PAGES

Paul, Blair G.; Ding, Haibing; Bagby, Sarah C.; ...

2017-02-27

The marine subsurface is a reservoir of the greenhouse gas methane. While microorganisms living in water column and seafloor ecosystems are known to be a major sink limiting net methane transport from the marine subsurface to the atmosphere, few studies have assessed the flow of methane-derived carbon through the benthic mat communities that line the seafloor on the continental shelf where methane is emitted. We analyzed the abundance and isotope composition of fatty acids in microbial mats grown in the shallow Coal Oil Point seep field off Santa Barbara, CA, USA, where seep gas is a mixture of methane andmore » CO 2. We further used stable isotope probing (SIP) to track methane incorporation into mat biomass. We found evidence that multiple allochthonous substrates supported the rich growth of these mats, with notable contributions from bacterial methanotrophs and sulfur-oxidizers as well as eukaryotic phototrophs. Fatty acids characteristic of methanotrophs were shown to be abundant and 13C-enriched in SIP samples, and DNA-SIP identified members of the methanotrophic family Methylococcaceae as major 13CH 4 consumers. Members of Sulfuricurvaceae, Sulfurospirillaceae, and Sulfurovumaceae are implicated in fixation of seep CO 2. The mats’ autotrophs support a diverse assemblage of co-occurring bacteria and protozoa, with Methylophaga as key consumers of methane-derived organic matter. This study identifies the taxa contributing to the flow of seep-derived carbon through microbial mat biomass, revealing the bacterial and eukaryotic diversity of these remarkable ecosystems.« less

Methane-Oxidizing Bacteria Shunt Carbon to Microbial Mats at a Marine Hydrocarbon Seep

PubMed Central

Paul, Blair G.; Ding, Haibing; Bagby, Sarah C.; Kellermann, Matthias Y.; Redmond, Molly C.; Andersen, Gary L.; Valentine, David L.

2017-01-01

The marine subsurface is a reservoir of the greenhouse gas methane. While microorganisms living in water column and seafloor ecosystems are known to be a major sink limiting net methane transport from the marine subsurface to the atmosphere, few studies have assessed the flow of methane-derived carbon through the benthic mat communities that line the seafloor on the continental shelf where methane is emitted. We analyzed the abundance and isotope composition of fatty acids in microbial mats grown in the shallow Coal Oil Point seep field off Santa Barbara, CA, USA, where seep gas is a mixture of methane and CO2. We further used stable isotope probing (SIP) to track methane incorporation into mat biomass. We found evidence that multiple allochthonous substrates supported the rich growth of these mats, with notable contributions from bacterial methanotrophs and sulfur-oxidizers as well as eukaryotic phototrophs. Fatty acids characteristic of methanotrophs were shown to be abundant and 13C-enriched in SIP samples, and DNA-SIP identified members of the methanotrophic family Methylococcaceae as major 13CH4 consumers. Members of Sulfuricurvaceae, Sulfurospirillaceae, and Sulfurovumaceae are implicated in fixation of seep CO2. The mats’ autotrophs support a diverse assemblage of co-occurring bacteria and protozoa, with Methylophaga as key consumers of methane-derived organic matter. This study identifies the taxa contributing to the flow of seep-derived carbon through microbial mat biomass, revealing the bacterial and eukaryotic diversity of these remarkable ecosystems. PMID:28289403

Biodiversity within hot spring microbial mat communities: molecular monitoring of enrichment cultures

NASA Technical Reports Server (NTRS)

Ward, D. M.; Santegoeds, C. M.; Nold, S. C.; Ramsing, N. B.; Ferris, M. J.; Bateson, M. M.

1997-01-01

We have begun to examine the basis for incongruence between hot spring microbial mat populations detected by cultivation or by 16S rRNA methods. We used denaturing gradient gel electrophoresis (DGGE) to monitor enrichments and isolates plated therefrom. At near extincting inoculum dilutions we observed Chloroflexus-like and cyanobacterial populations whose 16S rRNA sequences have been detected in the 'New Pit' Spring Chloroflexus mat and the Octopus Spring cyanobacterial mat. Cyanobacterial populations enriched from 44 to 54 degrees C and 56 to 63 degrees C samples at near habitat temperatures were similar to those previously detected in mat samples of comparable temperatures. However, a lower temperature enrichment from the higher temperature sample selected for the populations found in the lower temperature sample. Three Thermus populations detected by both DGGE and isolation exemplify even more how enrichment may bias our view of community structure. The most abundant population was adapted to the habitat temperature (50 degrees C), while populations adapted to 65 degrees C and 70 degrees C were 10(2)- and 10(4)-fold less abundant, respectively. However, enrichment at 70 degrees C favored the least abundant strain. Inoculum dilution and incubation at the habitat temperature favored the more numerically relevant populations. We enriched many other aerobic chemoorganotrophic populations at various inoculum dilutions and substrate concentrations, most of whose 16S rRNA sequences have not been detected in mats. A common feature of numerically relevant cyanobacterial, Chloroflexus-like and aerobic chemorganotrophic populations, is that they grow poorly and resist cultivation on solidified medium, suggesting plating bias, and that the medium composition and incubation conditions may not reflect the natural microenvironments these populations inhabit.

Production and Consumption of Hydrogen in Hot Spring Microbial Mats Dominated by a Filamentous Anoxygenic Photosynthetic Bacterium

PubMed Central

Otaki, Hiroyo; Everroad, R. Craig; Matsuura, Katsumi; Haruta, Shin

2012-01-01

Microbial mats containing the filamentous anoxygenic photosynthetic bacterium Chloroflexus aggregans develop at Nakabusa hot spring in Japan. Under anaerobic conditions in these mats, interspecies interaction between sulfate-reducing bacteria as sulfide producers and C. aggregans as a sulfide consumer has been proposed to constitute a sulfur cycle; however, the electron donor utilized for microbial sulfide production at Nakabusa remains to be identified. In order to determine this electron donor and its source, ex situ experimental incubation of mats was explored. In the presence of molybdate, which inhibits biological sulfate reduction, hydrogen gas was released from mat samples, indicating that this hydrogen is normally consumed as an electron donor by sulfate-reducing bacteria. Hydrogen production decreased under illumination, indicating that C. aggregans also functions as a hydrogen consumer. Small amounts of hydrogen may have also been consumed for sulfur reduction. Clone library analysis of 16S rRNA genes amplified from the mats indicated the existence of several species of hydrogen-producing fermentative bacteria. Among them, the most dominant fermenter, Fervidobacterium sp., was successfully isolated. This isolate produced hydrogen through the fermentation of organic carbon. Dispersion of microbial cells in the mats resulted in hydrogen production without the addition of molybdate, suggesting that simultaneous production and consumption of hydrogen in the mats requires dense packing of cells. We propose a cyclic electron flow within the microbial mats, i.e., electron flow occurs through three elements: S (elemental sulfur, sulfide, sulfate), C (carbon dioxide, organic carbon) and H (di-hydrogen, protons). PMID:22446313

Eric Kandel's Reductionism in Art and Brain Science - Bridging the Two Cultures.

PubMed

Bilsky, Ed

2017-01-01

Reductive art is a term to describe an artistic style or an aesthetic, rather than an art movement. It is stripping down as a new way of seeing. Movements and other terms that are sometimes associated with reductive art include abstract art, minimalism, ABC art, anti-illusionism, cool art, and rejective art. Eric Kandel's fifth book focuses on reductionism as the principle guiding an ongoing dialogue between the worlds of science and art .

Development of an active isolation mat based on dielectric elastomer stack actuators for mechanical vibration cancellation

NASA Astrophysics Data System (ADS)

Karsten, Roman; Flittner, Klaus; Haus, Henry; Schlaak, Helmut F.

2013-04-01

This paper describes the development of an active isolation mat for cancelation of vibrations on sensitive devices with a mass of up to 500 gram. Vertical disturbing vibrations are attenuated actively while horizontal vibrations are damped passively. The dimensions of the investigated mat are 140 × 140 × 20 mm. The mat contains 5 dielectric elastomer stack actuators (DESA). The design and the optimization of active isolation mat are realized by ANSYS FEM software. The best performance shows a DESA with air cushion mounted on its circumference. Within the mounting encased air increases static and reduces dynamic stiffness. Experimental results show that vibrations with amplitudes up to 200 μm can be actively eliminated.

Nitrogen fixation in a non-heterocystous cyanobacterial mat from a mountain river

NASA Astrophysics Data System (ADS)

Berrendero, Esther; Valiente, Eduardo Fernández; Perona, Elvira; Gómez, Claudia L.; Loza, Virginia; Muñoz-Martín, M. Ángeles; Mateo, Pilar

2016-08-01

In situ nitrogen fixation was investigated in a cyanobacterial mat growing on the bed of rocks of the Muga River, Spain. The filamentous non-heterocystous cyanobacterium Schizothrix dominated the mat, showing nitrogenase activity in the light at similar rates to those found in nearby heterocystous Rivularia colonies. N2 fixation in the light was significantly increased by an inhibitor of PSII and oxygen evolution, DCMU (3-[3,4-dichlorophenyl]-1,1-dimethylurea), and anaerobic conditions. However, no nitrogenase activity was found in the dark. Addition of fructose as a respiratory substrate induced nitrogenase activity in samples incubated under aerobic conditions in the dark but not in anaerobic conditions. Microelectrode oxygen profiles showed internal microaerobic microzones where nitrogen fixation might concentrate. Analyses of the 16S rRNA gene revealed only the presence of sequences belonging to filamentous non-heterocystous cyanobacteria. nifH gene diversity showed that the major phylotypes also belonged to this group. One of the three strains isolated from the Schizothrix mat was capable of fixing N2 and growing in the absence of combined N. This was consistent with the nifH gene analysis. These results suggest a relevant contribution of non-heterocystous cyanobacteria to nitrogen fixation in these mats.

Author's Guide and Style Manual to Publications of the ERIC Clearinghouse on Reading. Preliminary Edition.

ERIC Educational Resources Information Center

Siffin, Catherine F.; And Others

Guidelines for preparing monographs, short interpretive papers, and bibliographies for the ERIC Clearinghouse on Reading are given in Part I. Special considerations which are discussed concerning monographs are (1) identification of the problem area, (2) focus, (3) audience, (4) research base, (5) treatment of the research, (6) comprehensiveness,…

Millimeter Wavelength Observations of Galactic Sources with the Mobile Anisotropy Telescope (MAT)

NASA Astrophysics Data System (ADS)

Cruz, K. L.; Caldwell, R.; Devlin, M. J.; Dorwart, W. B.; Herbig, T.; Miller, A. D.; Nolta, M. R.; Page, L. A.; Puchalla, J. L.; Torbet, E.; Tran, H. T.

1999-12-01

The Mobile Anisotropy Telescope (MAT) has completed two observing seasons (1997 and 1998) in Chile from the Cerro Toco site. Although the primary goal of MAT was to measure anisotropy in the Cosmic Microwave Background (CMB) radiation, the chosen observation scheme also allowed daily viewing of the Galactic Plane. We present filtered maps at 30, 40 and 144 GHz of a region of the Galactic Plane which contains several millimeter-bright regions including the Carinae nebula and IRAS 11097-6102. We report the best fit brightness temperatures as well as the total flux densities in the MAT beams (0.9, 0.6 and 0.2 degrees FWHM) . The data are calibrated with respect to Jupiter whose flux is known to better than 8% in all frequency bands. This work was funded by the National Science Foundation and the Packard Foundation.

Topographic control of mat-surface structures evolution: Examples from modern evaporitic carbonate (Abu Dhabi) and evaporitic siliciclastic (Tunisia) tidal flats.

NASA Astrophysics Data System (ADS)

Hafid Bouougri, El; Porada, Hubertus

2010-05-01

In terms of optimal light utilization, mat surfaces ideally are flat. In nature, however, flat mat surfaces are observed rarely or in restricted patches only. Rather they are shaped by a variety of linear and subcircular to irregular protrusions at various scales, including overgrown upturned crack margins, bulges (‘petees'), domes (‘blisters' and ‘pustules'), reticulate networks with tufts and pinnacles etc. These features are so characteristic that ‘mat types' have been established according to their prevalence, e.g., film, flat, smooth, crinkle, blister, tufted, cinder, mammilate, pustular and polygonal mats (Kendall and Skipwith, 1969; Logan et al., 1974). Responsible for the development of such mat surface features are environmental (physical and chemical) factors and, in reaction, the opportunistic growth behaviour of the participating bacterial taxa. Theoretically, a ‘juvenile' mat may be assumed as being flat, evolving into various forms with typical surface morphologies according to environmental impacts and respective bacterial reactions. Observations in the Abu Dhabi evaporitic carbonate tidal flats and Tunisian evaporitic siliciclastic tidal flats demonstrate that topography plays a fundamental role, both on the large scale of the tidal flat and on the small scale of mat surface morphology. It controls, together with related factors like, e.g., frequency of tidal flooding; duration of water cover; frequency and duration of subaerial exposure, the spatial distribution and the temporal evolution of mat surface structures. On the tidal flat scale, topographic differences result a priori from its seaward gradient and may arise additionally from physical processes which may modify the substrate surface and produce in the intertidal and lower supratidal zones narrow creeks and shallow depressions meandering perpendicular to the slope. Within a wide tidal flat without local topographic changes in the tidal zones, mat surface structures display a

The Top 10 Reasons to Pursue a Career in Science & Technology - by Eric Isaacs

DOE Office of Scientific and Technical Information (OSTI.GOV)

Isaacs, Eric

2011-01-01

Eric Isaacs, director of Argonne National Laboratory and a physicist by training, spoke to recipients of the U.S. Department of Energy Office of Science Graduate Fellowships. Among the topics: Why choose a career in science and tech? More info on the fellowships, which are offered every year: http://scgf.orau.gov/index.html August 9, 2010

The Top 10 Reasons to Pursue a Career in Science & Technology - by Eric Isaacs

ScienceCinema

Isaacs, Eric

2018-02-07

Eric Isaacs, director of Argonne National Laboratory and a physicist by training, spoke to recipients of the U.S. Department of Energy Office of Science Graduate Fellowships. Among the topics: Why choose a career in science and tech? More info on the fellowships, which are offered every year: http://scgf.orau.gov/index.html August 9, 2010

Evaluation of various isotherm models, and metal sorption potential of cyanobacterial mats in single and multi-metal systems.

PubMed

Kumar, Dhananjay; Pandey, Lalit K; Gaur, J P

2010-12-01

Isotherm curves for the biosorption of Cu(II), Cd(II) and Pb(II) by the biomass of five different cyanobacterial mats (Mat # 1-5) showed concave shape and plateau. Suitability of ten different isotherm models was evaluated for the equilibrium modeling of these isotherm curves, however, only the Toth model was found appropriate. Mat # 2, dominated by Phormidium sp., was identified as an excellent metal biosorbent because: (i) the Toth estimated maximum biosorption capacity (mmol g(-1)) of Mat # 2 for Pb(II) (1.028), Cu(II) (0.696) and Cd(II) (0.549) was the highest among the tested mats and compares favourably with Langmuir estimated metal sorption capacity of many seaweeds, regarded as the best metal biosorbents, (ii) Na+, K+ and Ca2+ did not substantially inhibit the biosorption of the test metals, (iii) and total metal sorption ability of Mat # 2 increased or remained unaffected in binary and ternary metal systems. Copyright © 2010 Elsevier B.V. All rights reserved.

Timeline: exorcizing the animal spirits: Jan Swammerdam on nerve function.

PubMed

Cobb, M

2002-05-01

For more than 1,500 years, nerves were thought to function through the action of 'animal spirits'. In the seventeenth century, René Descartes conceived of these 'spirits' as liquids or gases, and used the idea to explain reflex action. But he was rapidly proven wrong by a young Dutchman, Jan Swammerdam. Swammerdam's elegant experiments pioneered the frog nerve muscle preparation and laid the foundation of our modern understanding of nerve function.

Jan Evangelista Purkynje (1787-1869): first to describe fingerprints.

PubMed

Grzybowski, Andrzej; Pietrzak, Krzysztof

2015-01-01

Fingerprints have been used for years as the accepted tool in criminology and for identification. The first system of classification of fingerprints was introduced by Jan Evangelista Purkynje (1787-1869), a Czech physiologist, in 1823. He divided the papillary lines into nine types, based on their geometric arrangement. This work, however, was not recognized internationally for many years. In 1858, Sir William Herschel (1833-1917) registered fingerprints for those signing documents at the Indian magistrate's office in Jungipoor. Henry Faulds (1843-1930) in 1880 proposed using ink for fingerprint determination and people identification, and Francis Galton (1822-1911) collected 8000 fingerprints and developed their classification based on the spirals, loops, and arches. In 1892, Juan Vucetich (1858-1925) created his own fingerprint identification system and proved that a woman was responsible for killing two of her sons. In 1896, a London police officer Edward Henry (1850-1931) expanded on earlier systems of classification and used papillary lines to identify criminals; it was his system that was adopted by the forensic world. The work of Jan Evangelista Purkynje (1787-1869) (Figure 1), who in 1823 was the first to describe in detail fingerprints, is almost forgotten. He also established their classification. The year 2013 marked the 190th anniversary of the publication of his work on this topic. Our contribution is an attempt to introduce the reader to this scientist and his discoveries in the field of fingerprint identification. Copyright © 2015.

2. X15 RUN UP AREA (Jan 59). A sharp, higher ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

2. X-15 RUN UP AREA (Jan 59). A sharp, higher altitide low oblique aerial view to the north, showing runway, at far left; X-15 Engine Test Complex in the center. This view predates construction of observation bunkers. - Edwards Air Force Base, X-15 Engine Test Complex, Rogers Dry Lake, east of runway between North Base & South Base, Boron, Kern County, CA

Within-Mat Variability in Anatoxin-a and Homoanatoxin-a Production among Benthic Phormidium (Cyanobacteria) Strains

PubMed Central

Wood, Susanna A.; Smith, Francine M. J.; Heath, Mark W.; Palfroy, Thomas; Gaw, Sally; Young, Roger G.; Ryan, Ken G.

2012-01-01

Benthic Phormidium mats can contain high concentrations of the neurotoxins anatoxin-a and homoanatoxin-a. However, little is known about the co-occurrence of anatoxin-producing and non-anatoxin-producing strains within mats. There is also no data on variation in anatoxin content among toxic genotypes isolated from the same mat. In this study, 30 Phormidium strains were isolated from 1 cm2 sections of Phormidium-dominated mats collected from three different sites. Strains were grown to stationary phase and their anatoxin-a, homoanatoxin-a, dihydroanatoxin-a and dihydrohomoanatoxin-a concentrations determined using liquid chromatography-mass spectrometry. Each strain was characterized using morphological and molecular (16S rRNA gene sequences) techniques. Eighteen strains produced anatoxin-a, dihydroanatoxin-a or homoanatoxin-a. Strains isolated from each mat either all produced toxins, or were a mixture of anatoxin and non-anatoxin-producing genotypes. Based on morphology these genotypes could not be separated. The 16S rRNA gene sequence comparisons showed a difference of at least 17 nucleotides among anatoxin and non-anatoxin-producing strains and these formed two separate sub-clades during phylogenetic analysis. The total anatoxin concentration among toxic strains varied from 2.21 to 211.88 mg kg−1 (freeze dried weight), representing a 100 fold variation in toxin content. These data indicate that both the relative abundance of anatoxin and non-anatoxin-producing genotypes, and variations in anatoxin producing capability, can influence the overall toxin concentration of benthic Phormidium mat samples. PMID:23162704

HiMAT highly maneuverable aircraft technology, flight report

NASA Technical Reports Server (NTRS)

1982-01-01

Flight verification of a primary flight control system, designed to control the unstable HiMAT aircraft is presented. The initial flight demonstration of a maneuver autopilot in the level cruise mode and the gathering of a limited amount of airspeed calibration data.

Reclamation of skid roads with fiber mats and native vegetation: effects on erosion

Treesearch

shawn T. Grushecky; David w. McGill; William Grafton; John Edwards; Lisa Tager

2007-01-01

A research study was established to test the effectiveness of fiber mats and native seed mixtures in reducing soil erosion from newly-constructed skid roads in the Elk River Watershed in central West Virginia. Twelve road sections of equal grade were paired with a randomly-selected section receiving a fiber mat and native grass seed while the other road section was not...

Development of novel electrospun dual-drug fiber mats loaded with a combination of ampicillin and metronidazole.

PubMed

Schkarpetkin, Dennis; Reise, Markus; Wyrwa, Ralf; Völpel, Andrea; Berg, Albrecht; Schweder, Martina; Schnabelrauch, Matthias; Watts, David C; Sigusch, Bernd W

2016-08-01

Our study was performed with the aim of preparing electrospun polylactide fibers with a combination of ampicillin (AMP) and metronidazole (MNZ) and investigating their drug release behavior and the antibacterial effect on Aggregatibacter actinomycetemcomitans and other oral pathogens. AMP and MNZ were integrated as a combination in two separate fibers (dual fiber mats - DFW mix) of electrospun PLA fiber mats by means of multijet electrospinning and in a single fiber (single fiber mats - SFW mix). HPLC (high-performance liquid chromatography) was used to measure the released drug quantities. Agar diffusion tests were used to determine the antibacterial effect of the eluates on A. actinomycetemcomitans, Fusobacterium nucleatum, Porphyromonas gingivalis and Enterococcus faecalis. The neutral red test was made to examine the cytocompatibility of the eluates with human gingival fibroblasts (hGFs). The release of the active agents varied with the antibiotic concentrations initially used in the fiber mats, but also with the distribution of the active agents in one or two fibers. Of the total quantity of MNZ (AMP), the SFW mix fiber mats released >60% (>70%) within a span of 5min, and 76% (71%) after 96h. With these drug concentrations released by the fiber mats (≥5m%), an antibacterial effect was achieved on A. actinomycetemcomitans and on all other species tested. Fiber mats and their eluates have no cytotoxic influence on human gingival fibroblasts (hGFs). Electrospun AMP/MNZ-loaded polymer fibers are a potential drug delivery system for use in periodontal and endodontic infections. Copyright © 2016 The Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

Unravelling core microbial metabolisms in the hypersaline microbial mats of Shark Bay using high-throughput metagenomics

PubMed Central

Ruvindy, Rendy; White III, Richard Allen; Neilan, Brett Anthony; Burns, Brendan Paul

2016-01-01

Modern microbial mats are potential analogues of some of Earth's earliest ecosystems. Excellent examples can be found in Shark Bay, Australia, with mats of various morphologies. To further our understanding of the functional genetic potential of these complex microbial ecosystems, we conducted for the first time shotgun metagenomic analyses. We assembled metagenomic next-generation sequencing data to classify the taxonomic and metabolic potential across diverse morphologies of marine mats in Shark Bay. The microbial community across taxonomic classifications using protein-coding and small subunit rRNA genes directly extracted from the metagenomes suggests that three phyla Proteobacteria, Cyanobacteria and Bacteriodetes dominate all marine mats. However, the microbial community structure between Shark Bay and Highbourne Cay (Bahamas) marine systems appears to be distinct from each other. The metabolic potential (based on SEED subsystem classifications) of the Shark Bay and Highbourne Cay microbial communities were also distinct. Shark Bay metagenomes have a metabolic pathway profile consisting of both heterotrophic and photosynthetic pathways, whereas Highbourne Cay appears to be dominated almost exclusively by photosynthetic pathways. Alternative non-rubisco-based carbon metabolism including reductive TCA cycle and 3-hydroxypropionate/4-hydroxybutyrate pathways is highly represented in Shark Bay metagenomes while not represented in Highbourne Cay microbial mats or any other mat forming ecosystems investigated to date. Potentially novel aspects of nitrogen cycling were also observed, as well as putative heavy metal cycling (arsenic, mercury, copper and cadmium). Finally, archaea are highly represented in Shark Bay and may have critical roles in overall ecosystem function in these modern microbial mats. PMID:26023869