Testlet-Based Multidimensional Adaptive Testing.

PubMed

Frey, Andreas; Seitz, Nicki-Nils; Brandt, Steffen

2016-01-01

Multidimensional adaptive testing (MAT) is a highly efficient method for the simultaneous measurement of several latent traits. Currently, no psychometrically sound approach is available for the use of MAT in testlet-based tests. Testlets are sets of items sharing a common stimulus such as a graph or a text. They are frequently used in large operational testing programs like TOEFL, PISA, PIRLS, or NAEP. To make MAT accessible for such testing programs, we present a novel combination of MAT with a multidimensional generalization of the random effects testlet model (MAT-MTIRT). MAT-MTIRT compared to non-adaptive testing is examined for several combinations of testlet effect variances (0.0, 0.5, 1.0, and 1.5) and testlet sizes (3, 6, and 9 items) with a simulation study considering three ability dimensions with simple loading structure. MAT-MTIRT outperformed non-adaptive testing regarding the measurement precision of the ability estimates. Further, the measurement precision decreased when testlet effect variances and testlet sizes increased. The suggested combination of the MTIRT model therefore provides a solution to the substantial problems of testlet-based tests while keeping the length of the test within an acceptable range.

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…

Testlet-Based Multidimensional Adaptive Testing

PubMed Central

Frey, Andreas; Seitz, Nicki-Nils; Brandt, Steffen

2016-01-01

Multidimensional adaptive testing (MAT) is a highly efficient method for the simultaneous measurement of several latent traits. Currently, no psychometrically sound approach is available for the use of MAT in testlet-based tests. Testlets are sets of items sharing a common stimulus such as a graph or a text. They are frequently used in large operational testing programs like TOEFL, PISA, PIRLS, or NAEP. To make MAT accessible for such testing programs, we present a novel combination of MAT with a multidimensional generalization of the random effects testlet model (MAT-MTIRT). MAT-MTIRT compared to non-adaptive testing is examined for several combinations of testlet effect variances (0.0, 0.5, 1.0, and 1.5) and testlet sizes (3, 6, and 9 items) with a simulation study considering three ability dimensions with simple loading structure. MAT-MTIRT outperformed non-adaptive testing regarding the measurement precision of the ability estimates. Further, the measurement precision decreased when testlet effect variances and testlet sizes increased. The suggested combination of the MTIRT model therefore provides a solution to the substantial problems of testlet-based tests while keeping the length of the test within an acceptable range. PMID:27917132

Fiber webs

Treesearch

Roger M. Rowell; James S. Han; Von L. Byrd

2005-01-01

Wood fibers can be used to produce a wide variety of low-density three-dimensional webs, mats, and fiber-molded products. Short wood fibers blended with long fibers can be formed into flexible fiber mats, which can be made by physical entanglement, nonwoven needling, or thermoplastic fiber melt matrix technologies. The most common types of flexible mats are carded, air...

Serological diagnosis of Leptospirosis in bovine serum samples using a microsphere immunoassay.

PubMed

Wynwood, S J; Burns, M A; Graham, G C; Weier, S L; McKay, D B; Craig, S B

2016-01-01

Leptospirosis causes significant economic loss within the cattle industry worldwide. Current diagnostic methods are generally inadequate for dealing with large numbers of samples, are outdated, and provide little useful diagnostic and epidemiological information. This aim of this study was to apply a microsphere immunoassay (MIA), utilising Luminex xMap technology, to 200 bovine serum samples to determine this method's usefulness in leptospirosis diagnosis in comparison with the current gold standard, the microscopic agglutination test (MAT). Although MAT is the most widely used laboratory test for the diagnosis of leptospirosis, its reliance on live cultures, subjective interpretation of results and an inability to differentiate between antibody classes, suggest MAT is no longer the best method for the diagnosis of leptospirosis. The results presented in this paper show that MIA was able to determine reactive from non-reactive samples when compared with MAT, and was able to differentiate IgG and IgM classes of antibody. The results suggest increased sensitivity in MIA and the ability to multiplex up to 500 antigens at one time allows for significant improvements in cost-effectiveness as well as a reduced dependency on live cultures. The relatively low cost, high throughput platform and differentiation of antibody class, as shown in previous research, make this assay worthy of consideration for the diagnosis of leptospirosis in small-scale or large-scale bovine populations.

Serological diagnosis of Leptospirosis in bovine serum samples using a microsphere immunoassay

PubMed Central

Wynwood, S. J.; Burns, M. A.; Graham, G. C.; Weier, S. L.; McKay, D. B.; Craig, S. B.

2016-01-01

Leptospirosis causes significant economic loss within the cattle industry worldwide. Current diagnostic methods are generally inadequate for dealing with large numbers of samples, are outdated, and provide little useful diagnostic and epidemiological information. This aim of this study was to apply a microsphere immunoassay (MIA), utilising Luminex xMap technology, to 200 bovine serum samples to determine this method's usefulness in leptospirosis diagnosis in comparison with the current gold standard, the microscopic agglutination test (MAT). Although MAT is the most widely used laboratory test for the diagnosis of leptospirosis, its reliance on live cultures, subjective interpretation of results and an inability to differentiate between antibody classes, suggest MAT is no longer the best method for the diagnosis of leptospirosis. The results presented in this paper show that MIA was able to determine reactive from non-reactive samples when compared with MAT, and was able to differentiate IgG and IgM classes of antibody. The results suggest increased sensitivity in MIA and the ability to multiplex up to 500 antigens at one time allows for significant improvements in cost-effectiveness as well as a reduced dependency on live cultures. The relatively low cost, high throughput platform and differentiation of antibody class, as shown in previous research, make this assay worthy of consideration for the diagnosis of leptospirosis in small-scale or large-scale bovine populations. PMID:26835139

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.

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

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.

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...

Development of Cellulose/PVDF-HFP Composite Membranes for Advanced Battery Separators

NASA Astrophysics Data System (ADS)

Castillo, Alejandro; Agubra, Victor; Alcoutlabi, Mataz; Mao, Yuanbing

Improvements in battery technology are necessary as Li-ion batteries transition from consumer electronic to vehicular and industrial uses. An important bottle-neck in battery efficiency and safety is the quality of the separators, which prevent electric short-circuits between cathode and anode, while allowing an easy flow of ions between them. In this study, cellulose acetate was dissolved in a mixed solvent with poly(vinylpyrrolidone) (PVP), and the mixture was forcespun in a peudo paper making process to yield nanofibrillated nonwoven mats. The mats were soaked in NaOH/Ethanol to strip PVP and regenerate cellulose from its acetate precursor. The cellulose mats were then dipped in poly(vinylidenefluoride-co-hexafluoropropylene) (PVDF-HFP) to yield the cellulose/PVDF-HFP composte membranes. These membranes were characterized chemically through FTIR spectroscopy and solvent-stability tests, thermally through DSC, physically by stress/strain measurements along with weight-based electrolyte uptake, and electrically by AC-impedance spectroscopy combined with capacitative cycling.

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.

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

HiMAT Subscale Research Vehicle Mated to B-52 Mothership in Flight, Close-up View

NASA Technical Reports Server (NTRS)

1980-01-01

A close-up view of the Highly Maneuverable Aircraft Technology (HiMAT) research vehicle attached to a wing pylon on NASA's B-52 mothership during a 1980 test flight. The HiMAT used sharply swept-back wings and a canard configuration to test possible technology for advanced fighters. NASA B-52, Tail Number 008, is an air launch carrier aircraft, 'mothership,' as well as a research aircraft platform that has been used on a variety of research projects. The aircraft, a 'B' model built in 1952 and first flown on June 11, 1955, is the oldest B-52 in flying status and has been used on some of the most significant research projects in aerospace history. Some of the significant projects supported by B-52 008 include the X-15, the lifting bodies, HiMAT (highly maneuverable aircraft technology), Pegasus, validation of parachute systems developed for the space shuttle program (solid-rocket-booster recovery system and the orbiter drag chute system), and the X-38. The B-52 served as the launch vehicle on 106 X-15 flights and flew a total of 159 captive-carry and launch missions in support of that program from June 1959 to October 1968. Information gained from the highly successful X-15 program contributed to the Mercury, Gemini, and Apollo human spaceflight programs as well as space shuttle development. Between 1966 and 1975, the B-52 served as the launch aircraft for 127 of the 144 wingless lifting body flights. In the 1970s and 1980s, the B-52 was the launch aircraft for several aircraft at what is now the Dryden Flight Research Center, Edwards, California, to study spin-stall, high-angle-of attack, and maneuvering characteristics. These included the 3/8-scale F-15/spin research vehicle (SRV), the HiMAT (Highly Maneuverable Aircraft Technology) research vehicle, and the DAST (drones for aerodynamic and structural testing). The aircraft supported the development of parachute recovery systems used to recover the space shuttle solid rocket booster casings. It also supported eight orbiter (space shuttle) drag chute tests in 1990. In addition, the B-52 served as the air launch platform for the first six Pegasus space boosters. During its many years of service, the B-52 has undergone several modifications. The first major modification was made by North American Aviation (now part of Boeing) in support of the X-15 program. This involved creating a launch-panel-operator station for monitoring the status of the test vehicle being carried, cutting a large notch in the right inboard wing flap to accommodate the vertical tail of the X-15 aircraft, and installing a wing pylon that enables the B-52 to carry research vehicles and test articles to be air-launched/dropped. Located on the right wing, between the inboard engine pylon and the fuselage, this wing pylon was subjected to extensive testing prior to its use. For each test vehicle the B-52 carried, minor changes were made to the launch-panel operator's station. Built originally by the Boeing Company, the NASA B-52 is powered by eight Pratt & Whitney J57-19 turbojet engines, each of which produce 12,000 pounds of thrust. The aircraft's normal launch speed has been Mach 0.8 (about 530 miles per hour) and its normal drop altitude has been 40,000 to 45,000 feet. It is 156 feet long and has a wing span of 185 feet. The heaviest load it has carried was the No. 2 X-15 aircraft at 53,100 pounds. Project manager for the aircraft is Roy Bryant.

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.

Maternal uniparental disomy 14 syndrome demonstrates prader-willi syndrome-like phenotype.

PubMed

Hosoki, Kana; Kagami, Masayo; Tanaka, Touju; Kubota, Masaya; Kurosawa, Kenji; Kato, Mitsuhiro; Uetake, Kimiaki; Tohyama, Jun; Ogata, Tsutomu; Saitoh, Shinji

2009-12-01

To delineate the significance of maternal uniparental disomy 14 (upd(14)mat) and related disorders in patients with a Prader-Willi syndrome (PWS)-like phenotype. We examined 78 patients with PWS-like phenotype who lacked molecular defects for PWS. The MEG3 methylation test followed by microsatellite polymorphism analysis of chromosome 14 was performed to detect upd(14)mat or other related abnormalities affecting the 14q32.2-imprinted region. We identified 4 patients with upd(14)mat and 1 patient with an epimutation in the 14q32.2 imprinted region. Of the 4 patients with upd(14)mat, 3 had full upd(14)mat and 1 was mosaic. Upd(14)mat and epimutation of 14q32.2 represent clinically discernible phenotypes and should be designated "upd(14)mat syndrome." This syndrome demonstrates a PWS-like phenotype particularly during infancy. The MEG3 methylation test can detect upd(14)mat syndrome defects and should therefore be performed for all undiagnosed infants with hypotonia.

Flight Test of Advanced Digital Control Concepts.

DTIC Science & Technology

1982-03-01

34 equations, and this result is then compared against the "model" equations. OPTION :::CREATrE ,CIEY, COFPY, MAT ,AMAT, COIP-YUMAT, BMAT , 74 COPFY, CMAT...BMATY .-COPY, NMAT, AMAT ,72 ,COPY, GMAT, RMA, COP:Y, (MAT, BMA’TCOFY, MA T ,AMAT >74, COPY, CMA’TsmA, PCOPY, RMAT, BmAT , pCOPYVMiAT , AMAo.T 72...COP’Y, MAT, AMAT, >75, COPY , MAtT, BMAT , COPY, ZMAT, AMAT, 74 ,COP’Y, MAT, TMAT, COPY, VMAT, AMAT, .:COPY ,RMAiT, MAT,73,COPW GMAT, E4MAT, COP-"YTMAT

Heuristic Constraint Management Methods in Multidimensional Adaptive Testing

ERIC Educational Resources Information Center

Born, Sebastian; Frey, Andreas

2017-01-01

Although multidimensional adaptive testing (MAT) has been proven to be highly advantageous with regard to measurement efficiency when several highly correlated dimensions are measured, there are few operational assessments that use MAT. This may be due to issues of constraint management, which is more complex in MAT than it is in unidimensional…

ECOMAT INC. BIOLOGICAL DENIFTRICATION PROCESS; SITE TECHNOLOGY CAPSULE

EPA Science Inventory

EcoMat, Inc. of Hayward, California (EcoMat) has developed an ex situ anoxic biofilter biodenitrification (BDN) process. The process uses specific biocarriers and bacteria to treat nitrate-contaminated water and employs a patented reactor that retains biocarrier within the syste...

Performance and durability tests of smart icephobic coatings to reduce ice adhesion

NASA Astrophysics Data System (ADS)

Janjua, Zaid A.; Turnbull, Barbara; Choy, Kwang-Leong; Pandis, Christos; Liu, Junpeng; Hou, Xianghui; Choi, Kwing-So

2017-06-01

The accretion of ice can cause damage in applications ranging from power lines and shipping decks, to wind turbines and rail infrastructure. In particular on aircraft, it can change aerodynamic characteristics, greatly affecting the flight safety. Commercial aircraft are therefore required to be equipped with de-icing devices, such as heating mats over the wings. The application of icephobic coatings near the leading edge of a wing can in theory reduce the high power requirements of heating mats, which melt ice that forms there. Such coatings are effective in preventing the accretion of runback ice, formed from airborne supercooled droplets, or the water that the heating mats generate as it is sheared back over the wing's upper surface. However, the durability and the practicality of applying them over a large wing surface have been prohibitive factors in deploying this technology so far. Here, we evaluated the ice adhesion strength of four non-conductive coatings and seven thermally conductive coatings by shearing ice samples from coated plates by spinning them in a centrifuge device. The durability of the coating performance was also assessed by repeating the tests, each time regrowing ice samples on the previously-used coatings. Contact angle parameters of each coating were tested for each test to determine influence on ice adhesion strength. The results indicate that contact angle hysteresis is a crucial parameter in determining icephobicity of a coating and hydrophobicity is not necessarily linked to icephobicity.

HiMAT Subscale Research Vehicle Mated to B-52 Mothership in Flight

NASA Technical Reports Server (NTRS)

1980-01-01

The Highly Maneuverable Aircraft Technology (HiMAT) research vehicle is shown here mated to a wing pylon on NASA's B-52 mothership aircraft. The HiMAT was a technology demonstrator to test structures and configurations for advanced fighter concepts. Over the course of more than 40 years, the B-52 proved a valuable workhorse for NASA's Dryden Flight Research Center (under various names), launching a wide variety of vehicles and conducting numerous other research flights. NASA B-52, Tail Number 008, is an air launch carrier aircraft, 'mothership,' as well as a research aircraft platform that has been used on a variety of research projects. The aircraft, a 'B' model built in 1952 and first flown on June 11, 1955, is the oldest B-52 in flying status and has been used on some of the most significant research projects in aerospace history. Some of the significant projects supported by B-52 008 include the X-15, the lifting bodies, HiMAT (highly maneuverable aircraft technology), Pegasus, validation of parachute systems developed for the space shuttle program (solid-rocket-booster recovery system and the orbiter drag chute system), and the X-38. The B-52 served as the launch vehicle on 106 X-15 flights and flew a total of 159 captive-carry and launch missions in support of that program from June 1959 to October 1968. Information gained from the highly successful X-15 program contributed to the Mercury, Gemini, and Apollo human spaceflight programs as well as space shuttle development. Between 1966 and 1975, the B-52 served as the launch aircraft for 127 of the 144 wingless lifting body flights. In the 1970s and 1980s, the B-52 was the launch aircraft for several aircraft at what is now the Dryden Flight Research Center, Edwards, California, to study spin-stall, high-angle-of attack, and maneuvering characteristics. These included the 3/8-scale F-15/spin research vehicle (SRV), the HiMAT (Highly Maneuverable Aircraft Technology) research vehicle, and the DAST (drones for aerodynamic and structural testing). The aircraft supported the development of parachute recovery systems used to recover the space shuttle solid rocket booster casings. It also supported eight orbiter (space shuttle) drag chute tests in 1990. In addition, the B-52 served as the air launch platform for the first six Pegasus space boosters. During its many years of service, the B-52 has undergone several modifications. The first major modification was made by North American Aviation (now part of Boeing) in support of the X-15 program. This involved creating a launch-panel-operator station for monitoring the status of the test vehicle being carried, cutting a large notch in the right inboard wing flap to accommodate the vertical tail of the X-15 aircraft, and installing a wing pylon that enables the B-52 to carry research vehicles and test articles to be air-launched/dropped. Located on the right wing, between the inboard engine pylon and the fuselage, this wing pylon was subjected to extensive testing prior to its use. For each test vehicle the B-52 carried, minor changes were made to the launch-panel operator's station. Built originally by the Boeing Company, the NASA B-52 is powered by eight Pratt & Whitney J57-19 turbojet engines, each of which produce 12,000 pounds of thrust. The aircraft's normal launch speed has been Mach 0.8 (about 530 miles per hour) and its normal drop altitude has been 40,000 to 45,000 feet. It is 156 feet long and has a wing span of 185 feet. The heaviest load it has carried was the No. 2 X-15 aircraft at 53,100 pounds. Project manager for the aircraft is Roy Bryant.

Validation of a Microsphere Immunoassay for Serological Leptospirosis Diagnosis in Human Serum by Comparison to the Current Gold Standard

PubMed Central

Wynwood, Sarah J.; Burns, Mary-Anne A.; Graham, Glenn C.; Weier, Steven L.; McKay, David B.; Craig, Scott B.

2015-01-01

A microsphere immunoassay (MIA) utilising Luminex xMap technology that is capable of determining leptospirosis IgG and IgM independently was developed. The MIA was validated using 200 human samples submitted for routine leptospirosis serology testing. The traditional microscopic agglutination (MAT) method (now 100 years old) suffers from a significant range of technical problems including a dependence on antisera which is difficult to source and produce, false positive reactions due to auto-agglutination and an inability to differentiate between IgG and IgM antibodies. A comparative validation method of the MIA against the MAT was performed and used to determine the ability of the MIA to detect leptospiral antibodies when compared with the MAT. The assay was able to determine samples in the reactive, equivocal and non-reactive ranges when compared to the MAT and was able to differentiate leptospiral IgG antibodies from leptospiral IgM antibodies. The MIA is more sensitive than the MAT and in true infections was able to detect low levels of antibody in the later stages of the acute phase as well as detect higher levels of IgM antibody earlier in the immune phase of the infection. The relatively low cost, high throughput platform and significantly reduced dependency on large volumes of rabbit antisera make this assay worthy of consideration for any microbiological assay that currently uses agglutination assays. PMID:25807009

Bear Creek Valley characterization area mixed wastes passive in situ treatment technology demonstration project - status report

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

Watson, D.; Leavitt, M.; Moss, D.

1997-03-01

Historical waste disposal activities within the Bear Creek Valley (BCV) Characterization Area (CA), at the U.S. Department of Energy (DOE) Oak Ridge Y-12 plant, have contaminated groundwater and surface water above human health risk levels and impacted the ecology of Bear Creek. Contaminates include nitrate, radioisotopes, metals, volatile organic chemicals (VOCS), and common ions. This paper provides a status report on a technology demonstration project that is investigating the feasibility of using passive in situ treatment systems to remove these contaminants. Although this technology may be applicable to many locations at the Oak Ridge Y-12 Plant, the project focuses onmore » collecting the information needed to take CERCLA removal actions in 1998 at the S-3 Disposal Ponds site. Phase 1 has been completed and included site characterization, laboratory screening of treatment media (sorbents; and iron), and limited field testing of biological treatment systems. Batch tests using different Y-12 Plant waters were conducted to evaluate the removal efficiencies of most of the media. Phase 1 results suggest that the most promising treatment media are Dowex 21 k resin, peat moss, zero-valent iron, and iron oxides. Phase 2 will include in-field column testing of these media to assess loading rates, and concerns with clogging, by-products, and long-term treatment efficiency and media stability. Continued testing of wetlands and algal mats (MATs) will be conducted to determine if they can be used for in-stream polishing of surface water. Hydraulic testing of a shallow trench and horizontal well will also be completed during Phase 2. 4 refs., 3 tabs.« less

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.

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.

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.

Influence of free-stall flooring on comfort and hygiene of dairy cows during warm climatic conditions.

PubMed

De Palo, P; Tateo, A; Zezza, F; Corrente, M; Centoducati, P

2006-12-01

An evaluation of behavioral and hygienic conditions was carried out with 4 materials used as free-stall flooring for dairy cows: polyethylene vinyl acetate (EVA) and polypropylene vinyl acetate (PVA) mats, wood shavings, and solid manure. The free-stall type selected by cows was evaluated in response to changes in environmental temperature and humidity. Two tests were used: 1) a preference test, in which 8 cows were housed in a pen with 32 free stalls and 4 types of flooring; and 2) an aversion test, in which 32 cows were placed in 4 pens, each with 8 free stalls. The free stalls in each pen had a single type of bedding material. These tests showed that the comfort of dairy cows was predominantly influenced by environmental conditions. The preference test for lying showed that cows preferred free-stall floors with EVA mats over those with PVA mats, wood shavings, and solid manure (332.4 +/- 24.0 vs. 130.8 +/- 6.2, 160.9 +/- 23.7, and 102.6 +/- 23.2 min/d, respectively), but under conditions of heat stress, with a temperature-humidity index > 80, they chose wood shavings and solid manure lying areas. These results were confirmed by the aversion test. In all experimental and environmental conditions, the PVA mats were the least suitable. The mats contaminated with organic manure and the free stalls bedded with wood shavings and organic solids did not differ in either the coliform load on the lying surfaces (EVA mats: 290 +/- 25; PVA mats: 306 +/- 33; wood shavings: 290 +/- 39; and solid manure: 305 +/- 23 log(10) cfu/mL) or the total bacterial count in the raw milk (EVA mats: 232 +/- 22; PVA mats: 233 + 24; wood shavings: 221 +/- 24; and solid manure: 220 +/- 25 log(10) cfu/mL). These results demonstrate that the comfort of dairy cows housed in barns with free stalls as resting areas does not depend only on the material used, but also on the value of the material in microenvironmental conditions.

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...

Design and Performance of an Enhanced Bioremediation Pilot Test in a Tidal Wetland Seep, West Branch Canal Creek, Aberdeen Proving Ground, Maryland

USGS Publications Warehouse

Majcher, Emily H.; Lorah, Michelle M.; Phelan, Daniel J.; McGinty, Angela L.

2009-01-01

Because of a lack of available in situ remediation methods for sensitive wetland environments where contaminated groundwater discharges, the U.S. Geological Survey, in cooperation with the U.S. Army Garrison, Aberdeen Proving Ground, Maryland, conceived, designed, and pilot tested a permeable reactive mat that can be placed horizontally at the groundwater/surface-water interface. Development of the reactive mat was part of an enhanced bioremediation study in a tidal wetland area along West Branch Canal Creek at Aberdeen Proving Ground, where localized areas of preferential discharge (seeps) transport groundwater contaminated with carbon tetrachloride, chloroform, tetrachloroethene, trichloroethene, and 1,1,2,2-tetrachloroethane from the Canal Creek aquifer to land surface. The reactive mat consisted of a mixture of commercially available organic- and nutrient-rich peat and compost that was bioaugmented with a dechlorinating microbial consortium, WBC-2, developed for this study. Due to elevated chlorinated methane concentrations in the pilot test site, a layer of zero-valent iron mixed with the peat and compost was added at the base of the reactive mat to promote simultaneous abiotic and biotic degradation. The reactive mat for the pilot test area was designed to optimize chlorinated volatile organic compound degradation efficiency without altering the geotechnical and hydraulic characteristics, or creating undesirable water quality in the surrounding wetland area, which is referred to in this report as achieving geotechnical, hydraulic, and water-quality compatibility. Optimization of degradation efficiency was achieved through the selection of a sustainable organic reactive matrix, electron donor, and bioaugmentation method. Consideration of geotechnical compatibility through design calculations of bearing capacity, settlement, and geotextile selection showed that a 2- to 3-feet tolerable thickness of the mat was possible, with 0.17 feet settlement predicted for unconsolidated sediments between 1.5 and 6 years following installation of the reactive mat. To ensure hydraulic compatibility in the mat design, mat materials that had a hydraulic conductivity greater than the surrounding wetland sediments were selected, and the mixture was optimized to consist of 1.5 parts compost, 1.5 parts peat and 1 part sand as a safeguard against fluidization. Sediment and matrix properties also indicated that a nonwoven geotextile with a cross-plane flow greater than that of the native sediments was suitable as the base of the reactive mat. Another nonwoven geotextile was selected for installation between the iron mix and organic zones of the mat to create more laminar flow conditions within the mat. Total metals and sequential extraction procedure analyses of mat materials, which were conducted to evaluate water-quality compatibility of the mat materials, showed that concentrations of metals in the compost ranged from one-half to one order of magnitude below consensus-based probable effect concentrations in sediment. A 22-inch-thick reactive mat, containing 0.5 percent WBC-2 by volume, was constructed at seep area 3-4W and monitored from October 2004 through October 2005 for the pilot test. No local, immediate failure of the mat or of wetland sediments was observed during mat installation, indicating that design estimates of bearing capacity and geotextile textile selection ensured the integrity of the mat and wetland sediments during and following installation. Measurements of surface elevation of the mat showed an average settlement of the mat surface of approximately 0.25 feet after 10 months, which was near the predicted settlement for unconsolidated sediment. Monitoring showed rapid establishment and sustainment throughout the year of methanogenic conditions conducive to anaerobic biodegradation and efficient dechlorination activity by WBC-2. The median mass removal of chloromethanes and total chloroethenes and ethane during the

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 certain limits. Overall topological roughness of the mats were analyzed and estimated in terms of the skin friction of the mats surfaces interacting with flow. Then, together with the critical erosional cohesive strength of the mats estimated, we present a theoretical physical model linking morphology and material strength of mats to overlying fluid flow. If this model were further tested true, it suggests that physical flows may very well have a controlling effect on the properties of mats growing within it.

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.

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.

State-of-the-Art Technologies for Construction in Space: a Review.

DTIC Science & Technology

1987-09-01

reinforcing fiber or fiber mat. Investigations of bonding, thermal stress, forming tech- niques, specific strengths, specific moduli, and microfracture...diameter and about 15 ft long. The graphite fibers follow the length of the tube and the polymer compound used as the matrix is applied over the graphite...combination of Sthese approaches to obtain the best simulation of the low-Earth orbit environment. Most materials tested to date are polymers such as

Simple Strategy to Prevent Severe Head Trauma in Judo —Biomechanical Analysis—

PubMed Central

Murayama, Haruo; Hitosugi, Masahito; Motozawa, Yasuki; Ogino, Masahiro; Koyama, Katsuhiro

2013-01-01

To determine whether the use of an under-mat has an effect on impact forces to the head in Judo, a Judo expert threw an anthropomorphic test device using the Osoto-gari and Ouchi-gari techniques onto a tatami (judo mat) with and without an under-mat. Head acceleration was measured and the head injury criterion (HIC) values with or without under-mat were compared. The use of an under-mat significantly decreased (p = 0.021) the HIC values from 1174.7 ± 246.7 (without under-mat) to 539.3 ± 43.5 in Ouchi-gari and from 330.0 ± 78.3 (without under-mat) to 156.1 ± 30.4 in Osoto-gari. The use of an under-mat simply reduces impact forces to the head in Judo. Rule changes are not necessary and the enjoyment and health benefits of Judo are maintained. PMID:24067767

Simple strategy to prevent severe head trauma in Judo.

PubMed

Murayama, Haruo; Hitosugi, Masahito; Motozawa, Yasuki; Ogino, Masahiro; Koyama, Katsuhiro

2013-01-01

To determine whether the use of an under-mat has an effect on impact forces to the head in Judo, a Judo expert threw an anthropomorphic test device using the Osoto-gari and Ouchi-gari techniques onto a tatami (judo mat) with and without an under-mat. Head acceleration was measured and the head injury criterion (HIC) values with or without under-mat were compared. The use of an under-mat significantly decreased (p = 0.021) the HIC values from 1174.7 ± 246.7 (without under-mat) to 539.3 ± 43.5 in Ouchi-gari and from 330.0 ± 78.3 (without under-mat) to 156.1 ± 30.4 in Osoto-gari. The use of an under-mat simply reduces impact forces to the head in Judo. Rule changes are not necessary and the enjoyment and health benefits of Judo are maintained.

Applicability of the Monocyte Activation Test (MAT) in the quality control of the 17DD yellow fever vaccine.

PubMed

de Mattos, Katherine Antunes; Navega, Elaine Cristina Azevedo; Silva, Vitor Fernandes; Almeida, Alessandra Santos; da Silva, Cristiane Caldeira; Presgrave, Octavio Augusto França; Junior, Daniel da Silva Guedes; Delgado, Isabella Fernandes

2018-03-01

The need for alternatives to animal use in pyrogen testing has been driven by the Three Rs concept. This has resulted in the inclusion of the monocyte activation test (MAT) in the European Pharmacopoeia, 2010. However, some technical and regulatory obstacles must be overcome to ensure the effective implementation of the MAT by the industry, especially for the testing of biological products. The yellow fever (YF) vaccine (17DD-YFV) was chosen for evaluation in this study, in view of: a) the 2016-2018 outbreak of YF in Brazil; b) the increase in demand for 17DD-YFV doses; c) the complex production process with live attenuated virus; d) the presence of possible test interference factors, such as residual process components (e.g. ovalbumin); and e) the need for the investigation of other pyrogens that are not detectable by the methods prescribed in the YF vaccine monograph. The product-specific testing was carried out by using cryopreserved and fresh whole blood, and IL-6 and IL-1β levels were used as the marker readouts. After assessing the applicability of the MAT on a 1:10 dilution of 17DD-YFV, endotoxin and non-endotoxin pyrogens were quantified in spiked batches, by using the lipopolysaccharide and lipoteichoic acid standards, respectively. The quantitative analysis demonstrated the correlation between the MAT and the Limulus amoebocyte lysate (LAL) assays, with respect to the limits of endotoxin recovery in spiked batches and the detection of no pyrogenic contamination in commercial batches of 17DD-YFV. The data demonstrated the applicability of the MAT for 17DD-YFV pyrogen testing, and as an alternative method that can contribute to biological quality control studies. 2018 FRAME.

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.

A Comparison of Standardized Achievement Test Scores on Right and Left Brain Dominant Fourth-Grade Students.

ERIC Educational Resources Information Center

Bell, Michael L.; Roubinek, Darrell L.

1989-01-01

Compares fourth-graders' subtest scores on the Stanford Achievement Test (SAT), the Iowa Test of Basic Skills (ITBS), and the Metropolitan Achievement Test (MAT). Finds right-brain dominant students scored better on four SAT subtests, and left-brain dominant students scored better on four ITBS subtests and two MAT subtests. (NH)

Self-Healing Nanofiber-Reinforced Polymer Composites. 1. Tensile Testing and Recovery of Mechanical Properties.

PubMed

Lee, Min Wook; An, Seongpil; Jo, Hong Seok; Yoon, Sam S; Yarin, Alexander L

2015-09-09

The present work aims at development of self-healing materials capable of partially restoring their mechanical properties under the conditions of prolonged periodic loading and unloading, which is characteristic, for example, of aerospace applications. Composite materials used in these and many other applications frequently reveal multiple defects stemming from their original inhomogeneity, which facilitates microcracking and delamination at ply interfaces. Self-healing nanofiber mats may effectively prevent such damage without compromising material integrity. Two types of core-shell nanofibers were simultaneously electrospun onto the same substrate in order to form a mutually entangled mat. The first type of core-shell fibers consisted of resin monomer (dimethylsiloxane) within the core and polyacrylonitrile within the shell. The second type of core-shell nanofibers consisted of cure (dimethyl-methyl hydrogen-siloxane) within the core and polyacrylonitrile within the shell. These mutually entangled nanofiber mats were used for tensile testing, and they were also encased in polydimethylsiloxane to form composites that were also subsequently subjected to tensile testing. During tensile tests, the nanofibers can be damaged in stretching up to the plastic regime of deformation. Then, the resin monomer and cure was released from the cores and the polydimethylsiloxane resin was polymerized, which might be expected to result in the self-healing properties of these materials. To reveal and evaluate the self-healing properties of the polyacrylonitrile-resin-cure nanofiber mats and their composites, the results were compared to the tensile test results of the monolithic polyacrylonitrile nanofiber mats or composites formed by encasing polyacrylonitrile nanofibers in a polydimethylsiloxane matrix. The latter do not possess self-healing properties, and indeed, do not recover their mechanical characteristics, in contrast to the polyacrylonitrile-resin-cure nanofiber mats and the composites reinforced by such mats. This is the first work, to the best of our knowledge, where self-healing nanofibers and composites based on them were developed, tested, and revealed restoration of mechanical properties (stiffness) in a 24 h rest period at room temperature.

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.

Proof testing a bridge deck design with glass fiber reinforced polymer bars as top mat of reinforcement.

DOT National Transportation Integrated Search

2003-01-01

The primary objective of this project was to test a full-scale prototype of a bridge deck design containing glass fiber reinforced polymer (GFRP) bars as the top mat of reinforcement. The test deck mimics the design of the deck of one span of the new...

Evaluation of surveillance case definition in the diagnosis of leptospirosis, using the Microscopic Agglutination Test: a validation study.

PubMed

Dassanayake, Dinesh L B; Wimalaratna, Harith; Agampodi, Suneth B; Liyanapathirana, Veranja C; Piyarathna, Thibbotumunuwe A C L; Goonapienuwala, Bimba L

2009-04-22

Leptospirosis is endemic in both urban and rural areas of Sri Lanka and there had been many out breaks in the recent past. This study was aimed at validating the leptospirosis surveillance case definition, using the Microscopic Agglutination Test (MAT). The study population consisted of patients with undiagnosed acute febrile illness who were admitted to the medical wards of the Teaching Hospital Kandy, from 1st July 2007 to 31st July 2008. The subjects were screened to diagnose leptospirosis according to the leptospirosis case definition. MAT was performed on blood samples taken from each patient on the 7th day of fever. Leptospirosis case definition was evaluated in regard to sensitivity, specificity and predictive values, using a MAT titre >or= 1:800 for confirming leptospirosis. A total of 123 patients were initially recruited of which 73 had clinical features compatible with the surveillance case definition. Out of the 73 only 57 had a positive MAT result (true positives) leaving 16 as false positives. Out of the 50 who didn't have clinical features compatible with the case definition 45 had a negative MAT as well (true negatives), therefore 5 were false negatives. Total number of MAT positives was 62 out of 123. According to these results the test sensitivity was 91.94%, specificity 73.77%, positive predictive value and negative predictive values were 78.08% and 90% respectively. Diagnostic accuracy of the test was 82.93%. This study confirms that the surveillance case definition has a very high sensitivity and negative predictive value with an average specificity in diagnosing leptospirosis, based on a MAT titre of >or= 1: 800.

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.

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

Smart Book Charts

NASA Technical Reports Server (NTRS)

Chinnapongse, Ronald L.

2015-01-01

Smart book charts for TPSM: Heatshield for Extreme Entry Environment Technology (HEEET), Conformal Ablative TPS (CA-TPS), 3D Woven Multifunctional Ablative TPS (3D MAT), and Adaptable, Deployable, Entry and Placement Technology (ADEPT).

i RadMat: A thermo-mechanical testing system for in situ high-energy X-ray characterization of radioactive specimens

DOE PAGES

Zhang, Xuan; Xu, Chi; Wang, Leyun; ...

2017-01-27

Here, we present an in situ Radiated Materials (iRadMat) experimental module designed to interface with a servo-hydraulic load frame for X-ray measurements at beamline 1-ID at the Advanced Photon Source. This new capability allows in situ studies of radioactive specimens subject to thermo-mechanical loading using a suite of high-energy X-ray scattering and imaging techniques. The iRadMat is a radiation-shielded vacuum heating system with the sample rotation-under-load capability. We describe the design features and performances of the iRadMat and present a dataset from a 300 °C uniaxial tensile test of a neutron-irradiated pure Fe specimen to demonstrate its capabilities.

Six weeks of Mat Pilates training are enough to improve functional capacity in elderly women.

PubMed

Bertoli, Josefina; Biduski, Grazieli Maria; de la Rocha Freitas, Cíntia

2017-10-01

The aim of the study was to evaluate the effect of Mat Pilates on the functional capacity (FC) of elderly women before and after six weeks of intervention. Eighteen women aged 62.28 (±2.34) participated in the study. Timed Up and Go test, Timed Up Stairs, Timed Down Stairs, 30-s Chair Stand, Chair Sit-and-Reach and Back Scratch tests were assessed. The results showed significant improvements in all FC tests after six weeks of the Mat Pilates intervention. Summarizing, only six weeks of Mat Pilates training of 60 min per session, three times a week, three series beginning with six repetitions and eight repetitions at the last two weeks of intervention, were enough to improve FC in elderly women. Furthermore, the exercises difficulty increased from beginners to intermediate. Copyright © 2016 Elsevier Ltd. All rights reserved.

Characterizing Microbial Mat Morphology with Structure from Motion Techniques in Ice-Covered Lake Joyce, McMurdo Dry Valleys, Antarctica

NASA Astrophysics Data System (ADS)

Mackey, T. J.; Leidman, S. Z.; Allen, B.; Hawes, I.; Lawrence, J.; Jungblut, A. D.; Krusor, M.; Coleman, L.; Sumner, D. Y.

2015-12-01

Structure from Motion (SFM) techniques can provide quantitative morphological documentation of otherwise inaccessible benthic ecosystems such as microbial mats in Lake Joyce, a perennially ice-covered lake of the Antarctic McMurdo Dry Valleys (MDV). Microbial mats are a key ecosystem of MDV lakes, and diverse mat morphologies like pinnacles emerge from interactions among microbial behavior, mineralization, and environmental conditions. Environmental gradients can be isolated to test mat growth models, but assessment of mat morphology along these gradients is complicated by their inaccessibility: the Lake Joyce ice cover is 4-5 m thick, water depths containing diverse pinnacle morphologies are 9-14 m, and relevant mat features are cm-scale. In order to map mat pinnacle morphology in different sedimentary settings, we deployed drop cameras (SeaViewer and GoPro) through 29 GPS referenced drill holes clustered into six stations along a transect spanning 880 m. Once under the ice cover, a boom containing a second GoPro camera was unfurled and rotated to collect oblique images of the benthic mats within dm of the mat-water interface. This setup allowed imaging from all sides over a ~1.5 m diameter area of the lake bottom. Underwater lens parameters were determined for each camera in Agisoft Lens; images were reconstructed and oriented in space with the SFM software Agisoft Photoscan, using the drop camera axis of rotation as up. The reconstructions were compared to downward facing images to assess accuracy, and similar images of an object with known geometry provided a test for expected error in reconstructions. Downward facing images identify decreasing pinnacle abundance in higher sedimentation settings, and quantitative measurements of 3D reconstructions in KeckCAVES LidarViewer supplement these mat morphological facies with measurements of pinnacle height and orientation. Reconstructions also help isolate confounding variables for mat facies trends with measurements of lake bottom slope and underlying relief that could influence pinnacle growth. Comparison of 3D reconstructions to downward-facing drop camera images demonstrate that SFM is a powerful tool for documenting diverse mat morphologies across environmental gradients in ice-covered lakes.

Status of DSMT research program

NASA Technical Reports Server (NTRS)

Mcgowan, Paul E.; Javeed, Mehzad; Edighoffer, Harold H.

1991-01-01

The status of the Dynamic Scale Model Technology (DSMT) research program is presented. DSMT is developing scale model technology for large space structures as part of the Control Structure Interaction (CSI) program at NASA Langley Research Center (LaRC). Under DSMT a hybrid-scale structural dynamics model of Space Station Freedom was developed. Space Station Freedom was selected as the focus structure for DSMT since the station represents the first opportunity to obtain flight data on a complex, three-dimensional space structure. Included is an overview of DSMT including the development of the space station scale model and the resulting hardware. Scaling technology was developed for this model to achieve a ground test article which existing test facilities can accommodate while employing realistically scaled hardware. The model was designed and fabricated by the Lockheed Missile and Space Co., and is assembled at LaRc for dynamic testing. Also, results from ground tests and analyses of the various model components are presented along with plans for future subassembly and matted model tests. Finally, utilization of the scale model for enhancing analysis verification of the full-scale space station is also considered.

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.

Advances in lightweight nickel electrode technology

NASA Technical Reports Server (NTRS)

Coates, Dwaine; Paul, Gary; Daugherty, Paul

1989-01-01

Studies are currently underway to further the development of lightweight nickel electrode technology. Work is focused primarily on the space nickel-hydrogen system and nickel-iron system but is also applicable to the nickel-cadmium and nickel-zinc systems. The goal is to reduce electrode weight while maintaining or improving performance, thereby increasing electrode energy density. Two basic electrode structures are being investigated. The first is the traditional nickel sponge produced from sintered nickel-carbonyl powder. The second is a new material for this application which consists of a non-woven mat of nickel fiber. Electrodes are being manufactured, tested, and evaluated at the electrode and cell level.

Advances in lightweight nickel electrode technology

NASA Technical Reports Server (NTRS)

Coates, Dwaine; Paul, Gary; Wheeler, James R.; Daugherty, Paul

1989-01-01

Studies are currently underway to further the development of lightweight nickel electrode technology. Work is focused primarily on the space nickel-hydrogen system and nickel-iron system but is also applicable to the nickel-cadmium and nickel-zinc systems. The goal is to reduce electrode weight while maintaining or improving performance thereby increasing electrode energy density. Two basic electrode structures are being investigated. The first is the traditional nickel sponge produced from sintered nickel-carbonyl powder and the second is a new material for this application which consists of a non-woven mat of nickel fiber. Electrodes are being manufactured, tested and evaluated at the electrode and cell level.

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.

Bayesian estimation of sensitivity and specificity of the modified agglutination test and bioassay for detection of Toxoplasma gondii in free-range chickens

USDA-ARS?s Scientific Manuscript database

Toxoplasma gondii infects virtually all warm-blooded animals worldwide. Serological tests, including the modified agglutination test (MAT), are often used to determine exposure to the parasite. The MAT can be used for all hosts because it does not need species-specific reagents and has been shown to...

Testing the utility of matK and ITS DNA regions for discrimination of Allium species

USDA-ARS?s Scientific Manuscript database

Molecular phylogenetic analysis of the genus Allium L. has been mainly based on the nucleotide sequences of ITS region. In 2009 matK and rbcL were accepted as a two-locus DNA barcode to classify plant species by the Consortium for the Barcode of Life (CBOL) Plant Working Group. MatK region has been ...

Bone marrow fat accumulation accelerated by high fat diet is suppressed by exercise

PubMed Central

Styner, Maya; Thompson, William R.; Galior, Kornelia; Uzer, Gunes; Wu, Xin; Kadari, Sanjay; Case, Natasha; Xie, Zhihui; Sen, Buer; Romaine, Andrew; Pagnotti, Gabriel M.; Rubin, Clinton T.; Styner, Martin A.; Horowitz, Mark C.; Rubin, Janet

2014-01-01

Marrow adipose tissue (MAT), associated with skeletal fragility and hematologic insufficiency, remains poorly understood and difficult to quantify. We tested the response of MAT to high fat diet (HFD) and exercise using a novel volumetric analysis, and compared it to measures of bone quantity. We hypothesized that HFD would increase MAT and diminish bone quantity, while exercise would slow MAT acquisition and promote bone formation. Eight week-old female C57BL/6 mice were fed a regular (RD) or HFD, and exercise groups were provided voluntary access to running wheels (RD-E, HFD-E). Femoral MAT was assessed by μCT (lipid binder osmium) using a semi-automated approach employing rigid co-alignment, regional bone masks and was normalized for total femoral volume (TV) of the bone compartment. MAT was 2.6-fold higher in HFD relative to RD mice. Exercise suppressed MAT in RD-E mice by more than half compared with RD. Running similarly inhibited MAT acquisition in HFD mice. Exercise significantly increased bone quantity in both diet groups. Thus, HFD caused significant accumulation of MAT; importantly running exercise limited MAT acquisition while promoting bone formation during both diets. That MAT is exquisitely responsive to diet and exercise, and its regulation by exercise appears to be inversely proportional to effects on exercise induced bone formation, is relevant for an aging and sedentary population. PMID:24709686

Mobile Jump Assessment (mJump): A Descriptive and Inferential Study.

PubMed

Mateos-Angulo, Alvaro; Galán-Mercant, Alejandro; Cuesta-Vargas, Antonio

2015-08-26

Vertical jump tests are used in athletics and rehabilitation to measure physical performance in people of different age ranges and fitness. Jumping ability can be analyzed through different variables, and the most commonly used are fly time and jump height. They can be obtained by a variety of measuring devices, but most are limited to laboratory use only. The current generation of smartphones contains inertial sensors that are able to record kinematic variables for human motion analysis, since they are tools for easy access and portability for clinical use. The aim of this study was to describe and analyze the kinematics characteristics using the inertial sensor incorporated in the iPhone 4S, the lower limbs strength through a manual dynamometer, and the jump variables obtained with a contact mat in the squat jump and countermovement jump tests (fly time and jump height) from a cohort of healthy people. A cross sectional study was conducted on a population of healthy young adults. Twenty-seven participants performed three trials (n=81 jumps) of squat jump and countermovement jump tests. Acceleration variables were measured through a smartphone's inertial sensor. Additionally, jump variables from a contact mat and lower limbs dynamometry were collected. In the present study, the kinematic variables derived from acceleration through the inertial sensor of a smartphone iPhone 4S, dynamometry of lower limbs with a handheld dynamometer, and the height and flight time with a contact mat have been described in vertical jump tests from a cohort of young healthy subjects. The development of the execution has been described, examined and identified in a squat jump test and countermovement jump test under acceleration variables that were obtained with the smartphone. The built-in iPhone 4S inertial sensor is able to measure acceleration variables while performing vertical jump tests for the squat jump and countermovement jump in healthy young adults. The acceleration kinematics variables derived from the smartphone's inertial sensor are higher in the countermovement jump test than the squat jump test. ©Alvaro Mateos-Angulo, Alejandro Galán-Mercant, Antonio Cuesta-Vargas. Originally published in JMIR Rehabilitation and Assistive Technology (http://rehab.jmir.org), 26.08.2015.

Usefulness of a single-assay chemiluminescence test (Tularaemia VIRCLIA IgG + IgM monotest) for the diagnosis of human tularemia. Comparison of five serological tests.

PubMed

Cubero, África; Durántez, Carlos; Almaraz, Ana; Fernández-Lago, Luis; Gutiérrez, María P; Castro, María J; Bratos, Miguel A; Simarro, María; March, Gabriel A; Orduña, Antonio

2018-04-01

The aim of this work was to ascertain the usefulness of a new commercially-available single-assay chemiluminescence test (CHT) for the diagnosis of human tularemia (Tularaemia VIRCLIA IgG + IgM monotest, Vircell, Santa Fe, Granada, Spain). A total of 773 sera from 773 patients including 364 initial sera from patients with diagnosed tularemia, patients with suspected tularemia not confirmed (100), healthy people (152), patients with serology positive to Brucella (97), patients diagnosed with other infectious diseases (30), and patients diagnosed with autoimmune diseases (30) were included. All sera were tested by CHT, "in-house" microagglutination test (MAT), immunochromatographic test (ICT) (Virapid Tularaemia, Vircell, Santa Fe Granada, Spain), and "in-house" ELISA IgG, and ELISA IgM. Of the total initial sera, 334 (sensitivity 91.8%) were positive in the CHT, 332 (sensitivity 91.2%) in the MAT, 330 (sensitivity 90.7%) in the ICT, and 328 (sensitivity 90.1%) in the ELISA IgG and ELISA IgM tests. The specificity of the CHT was 96.7%; of the MAT, 100%; of the ICT, 98.7%; and of the ELISA IgG and ELISA IgM, 97.4%. In the group of patients with serology positive to Brucella, at least 12.4% of sera were positive in tularemia tests (12.4% in ELISA IgM, 13.4% in MAT, 14.4% in ICT, and 15.5% in CHT and ELISA IgG). In conclusion, CHT presents a sensitivity and specificity in early diagnosis of human tularemia, similar to MAT, ICT, and ELISA IgG and ELISA IgM. Its single assay design allows lower costs, especially in areas of low endemicity or inter-epidemic periods.

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...

A STUDY OF RECOVERING A REED ECOSYSTEM USING POROUS CONCRETE IN THE LAKE BIWA SHORE

NASA Astrophysics Data System (ADS)

Takeda, Naho; Kato, Hayato; Okamoto, Takahisa; Kojima, Takayuki

In this study, reed planting tests were carried out at the Biyo-center, an experiment station on the Lake Biwa shore, in order to evaluate the feasibility of a planting method with porous concrete (PoC method). Reed planting tests with coconut-fiber mats (mat method), which were generally used around Lake Biwa, were simultaneously carried out to compare with the PoC method. The reeds planted by the PoC method grew better than the ones planted by the mat method, and the number of reeds which were washed away by waves was smaller than that planted by the mat method. The result of the observation of reeds planted in the PoC showed plant maturation, and reeds could ta ke root into the PoC without interference with the voids of the PoC. As a result, it was shown that the reed planting tests with the PoC method was simple and effective, so it would become in harmony with the environment around Lake Biwa.

The effect of the 4MAT learning model on the achievement and motivation of 7th grade students on the subject of particulate nature of matter and an examination of student opinions on the model

NASA Astrophysics Data System (ADS)

Aktas, İdris; Bılgın, İbrahim

2015-01-01

Background:Many researchers agree that students, especially primary students, have learning difficulties on the 'Particulate Nature of Matter' unit. One reason for this difficulty is not considering individual differences for teaching science. In 4MAT model learning, environment is arranged according to individual differences. Purpose:The purpose of this study is to examine (1) the effects of the 4MAT learning model on the7th grade students' academic achievement and motivation on the 'Particulate Nature of Matter' unit and (2) identify student opinions on the 4MAT model. Sample:The sample consists of 235 students (115 experimental, 120 control) in Turkey. Design and methods:Experimental groups were instructed with the 4MAT model while control groups were instructed with a traditional method. Achievement Test (AchToM) and Motivation Scale (MotScl) were administered to students as pre- and post-tests. Moreover, the opinions of students in the experimental groups on the 4MAT model were ascertained through open-ended questions after the application. Results:According to independent t-test results, statistical difference in favour of the experimental groups was detected between the post-AchToM (ES = 1.43; p < .0001) and post-MotScl (ES = 0.32; p < .05) scores. According to data obtained from the questionnaire, the application of the 4MAT model increases student motivation and participation in the lesson, lessons are more amusing and enjoyable, and the self-confidence of the students increases. Besides these positive opinions, however, a few students stated that the method took too much time, they were not motivated and it did not help them in understanding the subject. Conclusions:The 4MAT model is more effective than traditional method in terms of increasing achievement and motivation. The model takes all learners into account. Thus, the teacher or educator should use the 4MAT model to ensure all students' learning in their classroom.

Soluble β-(1,3)-glucans enhance LPS-induced response in the monocyte activation test, but inhibit LPS-mediated febrile response in rabbits: Implications for pyrogenicity tests.

PubMed

Pardo-Ruiz, Zenia; Menéndez-Sardiñas, Dalia E; Pacios-Michelena, Anabel; Gabilondo-Ramírez, Tatiana; Montero-Alejo, Vivian; Perdomo-Morales, Rolando

2016-01-01

In the present study, we aimed to determine the influence of β-(1,3)-d-glucans on the LPS-induced pro-inflammatory cytokine response in the Monocyte Activation Test (MAT) for pyrogens, and on the LPS-induced febrile response in the Rabbit Pyrogen Test (RPT), thus evaluating the resulting effect in the outcome of each test. It was found that β-(1,3)-d-glucans elicited the production of pro-inflammatory cytokines IL-1β, IL-6 and TNF-α, also known as endogenous pyrogens, but not enough to classify them as pyrogenic according to MAT. The same β-(1,3)-d-glucans samples were non-pyrogenic by RPT. However, β-(1,3)-d-glucans significantly enhanced the LPS-induced pro-inflammatory cytokines response in MAT, insomuch that samples containing non-pyrogenic concentrations of LPS become pyrogenic. On the other hand, β-(1,3)-d-glucans had no effect on sub-pyrogenic LPS doses in the RPT, but surprisingly, inhibited the LPS-induced febrile response of pyrogenic LPS concentrations. Thus, while β-(1,3)-d-glucans could mask the LPS pyrogenic activity in the RPT, they exerted an overstimulation of pro-inflammatory cytokines in the MAT. Hence, MAT provides higher safety since it evidences an unwanted biological response, which is not completely controlled and is overlooked by the RPT. Copyright © 2015 Elsevier B.V. All rights reserved.

Marrow adipose tissue spectrum in obesity and type 2 diabetes mellitus.

PubMed

de Araújo, Iana M; Salmon, Carlos E G; Nahas, Andressa K; Nogueira-Barbosa, Marcello H; Elias, Jorge; de Paula, Francisco J A

2017-01-01

To assess the association of bone mass and marrow adipose tissue (MAT) with other fat depots, insulin resistance, bone remodeling markers, adipokines and glucose control in type 2 diabetes and obesity. The study groups comprised 24 controls (C), 26 obese (O) and 28 type 2 diabetes. Dual-energy X-ray absorptiometry was used to determine bone mineral density (BMD). Blood samples were collected for biochemical measurements. 1 H Magnetic resonance spectroscopy was used to assess MAT in the L3 vertebra, and abdominal magnetic resonance imaging was used to assess intrahepatic lipids in visceral (VAT) and subcutaneous adipose tissue. Regression analysis models were used to test the association between parameters. At all sites tested, BMD was higher in type 2 diabetes than in O and C subjects. The C group showed lower VAT values than the type 2 diabetes group and lower IHL than the O and type 2 diabetes groups. However, MAT was similar in the 3 groups. Osteocalcin and C-terminal telopeptide of type 1 collagen were lower in type 2 diabetes than those in C and O subjects. Moreover, at all sites, BMD was negatively associated with osteocalcin. No association was observed between MAT and VAT. No relationship was observed among MAT and HOMA-IR, leptin, adiponectin or Pref-1, but MAT was positively associated with glycated hemoglobin. MAT is not a niche for fat accumulation under conditions of energy surplus and type 2 diabetes, also is not associated with VAT or insulin resistance. MAT is associated with glycated hemoglobin. © 2017 European Society of Endocrinology.

New strategy for the survey of Toxoplasma gondii in meat for human consumption.

PubMed

Villena, Isabelle; Durand, Benoit; Aubert, Dominique; Blaga, Radu; Geers, Régine; Thomas, Myriam; Perret, Catherine; Alliot, Annie; Escotte-Binet, Sandie; Thébault, Anne; Boireau, Pascal; Halos, Lénaïg

2012-02-10

Monitoring of Toxoplasma infection in animals destined for human consumption is a great challenge for human toxoplasmosis prevention. This study aimed to compare results obtained from a naturally infected population of sheep using different tests and targeting an original matrix: meat samples and muscle fluids collected at the slaughterhouse. A commercial ELISA test was performed on diaphragm fluids from 419 ovine carcasses collected at the slaughterhouse. A MAT (modified agglutination test) was performed on heart fluids obtained from the same animals. In addition, all hearts were bioassayed in mice. Serological test agreement, the relative sensitivity of ELISA MAT and mouse bioassay as well as a correlation between titres and parasite isolation probability were statistically evaluated. The overall agreement (kappa coefficient=0.64) of ELISA on diaphragm fluids and MAT on heart fluids is substantial and subsequently both tests can be used for epidemiological studies. Relative sensitivity was higher for MAT performed on cardiac fluids (90%) than ELISA on diaphragm fluid (61%). For both serological tests, relative sensitivity is lower in lambs younger than 12 months. Relative sensitivity of mouse inoculation was 42%. A significant correlation was obtained between increasing MAT titres and probability to isolate live parasite from the heart. When the fluid titre was higher than 1:16, parasites were isolated in 65% of cases. When it was lower, isolation failed in 95% of the cases. According to our results, cardiac fluids appear to be a relevant matrix for toxoplasmosis survey in meat. Copyright © 2011 Elsevier B.V. All rights reserved.

The Lassen Astrobiology Intern Program - Concept, Implementation and Evaluation

NASA Astrophysics Data System (ADS)

Des Marais, D. J.; Dueck, S. L.; Davis, H. B.; Parenteau, M. N.; Kubo, M. D.

2014-12-01

The program goal was to provide a hands-on astrobiology learning experience to high school students by introducing astrobiology and providing opportunities to conduct field and lab research with NASA scientists. The program sought to increase interest in interdisciplinary science, technology, engineering, math and related careers. Lassen Volcanic National Park (LVNP), Red Bluff High School and the Ames Team of the NASA Astrobiology Institute led the program. LVNP was selected because it shares aspects of volcanism with Mars and it hosts thermal springs with microbial mat communities. Students documented volcanic deposits, springs and microbial mats. They analyzed waters and sampled rocks, water and microorganisms. They cultured microorganisms and studied chemical reactions between rocks and simulated spring waters. Each student prepared a report to present data and discuss relationships between volcanic rocks and gases, spring waters and microbial mats. At a "graduation" event the students presented their findings to the Red Bluff community. They visited Ames Research Center to tour the facilities and learn about science and technology careers. To evaluate program impact, surveys were given to students after lectures, labs, fieldwork and discussions with Ames scientists. Students' work was scored using rubrics (labs, progress reports, final report, presentation). Students took pre/post tests on core astrobiology concepts. Parents, teachers, rangers, Ames staff and students completed end-of-year surveys on program impact. Several outcomes were documented. Students had a unique and highly valued learning experience with NASA scientists. They understood what scientists do through authentic scientific work, and what scientists are like as individuals. Students became knowledgeable about astrobiology and how it can be pursued in the lab and in the field. The students' interest increased markedly in astrobiology, interdisciplinary studies and science generally.

Experimental Studies on Geocells and Mat Systems for Stabilization of Unpaved Shoulders and Temporary Roads

NASA Astrophysics Data System (ADS)

Guo, Jun

Geosynthetics have been used to improve the performance of geomaterials, especially when weak soil exists in roadway applications. In this study, two types of geosynthetic materials, geocell and a mat system, were studied for their applications for unpaved roads and shoulders. The study of geocell was focused on its application for unpaved shoulders. The ability of geocell to improve different geomaterials over intermediate strength subgrade and its possible effect on vegetation were investigated. The study of the mat system was focused on investigating the performance of the mat system over soft and intermediate subgrade with different strengths under cyclic loading to simulate temporary roadway conditions. In the study of geocell for the application for unpaved shoulders, six large scale plate loading tests were conducted on a single type of geocell on target 5% CBR subgrade to investigate the benefits of geocell reinforcement on different base course and topsoil combinations. Different base course and topsoil combinations were investigated including: 200-mm thick unreinforced aggregate, 200-mm thick soil-aggregate mixture (50% aggregate and 50% top soil) with and without geocell reinforcement, 200-mm thick geocell-reinforced topsoil, 50-mm thick aggregate over 150-mm soil-aggregate mixture (50% aggregate and 50% top soil), and 50-mm thick top soil over 150-mm thick geocell-reinforced soil-aggregate mixture (50% aggregate and 50% top soil). Earth pressure cells were install at the interface between subgrade and base course to monitor the load distribution. The cyclic plate loading tests showed that geocell effectively reduced the permanent deformation and the geocell-reinforced soil-aggregate mixture slightly outperformed the unreinforced aggregate at the same thickness. The plate loading tests also suggested the topsoil cover resulted in large permanent deformations. A one-year long outdoor field vegetation test was conducted on base courses with different combinations of aggregate and topsoil including: 200-mm thick unreinforced topsoil, 200-mm thick soil-aggregate mixture (50% aggregate and 50% topsoil), 50-mm thick aggregate over 150-mm soil-aggregate mixture (50% aggregate and 50% topsoil), and 50-mm thick topsoil over 150-mm reinforced soil-aggregate mixture (50% aggregate and 50% topsoil) to investigate the possible effect of geocell on shoulder vegetation established mainly by tall fescue grass and perennial ryegrass. One control (unreinforced) section and one geocell-reinforced section were prepared for each base course combination with a surface area of 1.5 m by 1.5 m. During the one-year test period, soil moisture temperature and volumetric moisture content were monitored. Weather data, such as precipitation and air temperature, were obtain from the nearby weather station at the Lawrence airport. Vegetation growth was evaluated by grass leaf blade length, root length, and grass density. Vegetation biomass was obtained at the end of the test. The test results showed no definite evidence of geocell influencing the vegetation in unpaved shoulders. In the study of the mat system, six large-scale cyclic plate loading tests were conducted on a single type of polyethylene mat system with anchorage to study its performance over soft and intermediate subgrade with the CBR ranging from 1% to 4%. For the comparison purposes, test sections with and without the mat system were prepared and evaluated. For the test section with 1% CBR subgrade, an aggregate base course was used for the test section without the mat system to enable the cyclic plate loading test. The size of the mat system under the investigation was 1.92 m by 1.92 m. A cyclic load at the magnitude of 40 kN was applied through a 300 mm diameter loading plate with a thin rubber pad to simulate a vehicle tire. Earth pressure cells were installed at the interface between the mat system and the subgrade to monitor the load distribution. Loading plate displacements were measured by the displacement transducer inside the actuator. Test results concluded that the mat system was more effective over the intermediate subgrade than the soft subgrade and when large permanent deformations were allowed.

The Matrix Analogies Test: A Validity Study with the K-ABC.

ERIC Educational Resources Information Center

Smith, Douglas K.

The Matrix Analogies Test-Expanded Form (MAT-EF) and Kaufman Assessment Battery for Children (K-ABC) were administered in counterbalanced order to two randomly selected samples of students in grades 2 through 5. The MAT-EF was recently developed to measure non-verbal reasoning. The samples included 26 non-handicapped second graders in a rural…

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

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

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.

Polyacrylonitrile nanofibers with added zeolitic imidazolate frameworks (ZIF-7) to enhance mechanical and thermal stability

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

Lee, Min Wook; An, Seongpil; Song, Kyo Yong

2015-12-28

Zeolitic imidazolate framework 7/polyacrylonitrile (ZIF-7/PAN) nanofiber mat of high porosity and surface area can be used as a flexible fibrous filtration membrane that is subjected to various modes of mechanical loading resulting in stresses and strains. Therefore, the stress-strain relation of ZIF-7/PAN nanofiber mats in the elastic and plastic regimes of deformation is of significant importance for numerous practical applications, including hydrogen storage, carbon dioxide capture, and molecular sensing. Here, we demonstrated the fabrication of ZIF-7/PAN nanofiber mats via electrospinning and report their mechanical properties measured in tensile tests covering the elastic and plastic domains. The effect of the matmore » fabrication temperature on the mechanical properties is elucidated. We showed the superior mechanical strength and thermal stability of the compound ZIF-7/PAN nanofiber mats in comparison with that of pure PAN nanofiber mats. Material characterization including scanning electron microscope, energy-dispersive X-ray spectroscopy, tensile tests, differential scanning calorimetry, and Fourier transform infrared spectroscopy revealed the enhanced chemical bonds of the ZIF-7/PAN complex.« less

Influence of layer-by-layer assembled electrospun poly (L-lactic acid) nanofiber mats on the bioactivity of endothelial cells

NASA Astrophysics Data System (ADS)

Wu, Keke; Zhang, Xiazhi; Yang, Wufeng; Liu, Xiaoyan; Jiao, Yanpeng; Zhou, Changren

2016-12-01

Electrospun poly(L-lactic acid) (PLLA) nanofiber mats were successfully modified by deposition of multilayers with chitosan (CS), heparin (Hep) and graphene oxide (GO) through electrostatic layer-by-layer (LBL) self-assembly method. In this study, the surface properties of PLLA nanofiber mats before and after modification were investigated via scanning electron microscope (SEM), atomic force microscopy (AFM), attenuated total reflectance fourier transformation infrared spectroscopy (ATR-FTIR), X-ray photoelectron spectroscopy (XPS) and water contact angle measurement. In addition, the cytocompatibility of the modified PLLA nanofiber mats were investigated by testing endothelial cells compatibility, including cell attachment, cell proliferation and cell cycle. The results revealed that the surfaces of modified PLLA nanofiber mats become much rougher, stifiness and the hydrophilicity of the LBL modified PLLA nanofiber mats were improved compared to original PLLA one. Moreover, the modified PLLA nanofiber mats had promoted the endothelial cells viability attachment significantly. Besides, we studied the PLLA nanofiber mats on the expression of necrosis factor (TNF-α), interleukine-1β (IL-1β), monocyte chemoattractant protein-1 (MCP-1) and vascular cell adhesion molecule-1 (VCAM-1) in endothelial cells. The results showed that modified PLLA nanofiber mats had inhibited the inflammatory response to some extent.

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

Atmospheric Pressure Plasma-Electrospin Hybrid Process for Protective Applications

NASA Astrophysics Data System (ADS)

Vitchuli Gangadharan, Narendiran

2011-12-01

Chemical and biological (C-B) warfare agents like sarin, sulfur mustard, anthrax are usually dispersed into atmosphere in the form of micro aerosols. They are considered to be dangerous weapon of mass destruction next to nuclear weapons. The airtight protective clothing materials currently available are able to stop the diffusion of threat agents but not good enough to detoxify them, which endangers the wearers. Extensive research efforts are being made to prepare advanced protective clothing materials that not only prevent the diffusion of C-B agents, but also detoxify them into harmless products thus ensuring the safety and comfort of the wearer. Electrospun nanofiber mats are considered to have effective filtration characteristics to stop the diffusion of submicron level particulates without sacrificing air permeability characteristics and could be used in protective application as barrier material. In addition, functional nanofibers could be potentially developed to detoxify the C-B warfare threats into harmless products. In this research, electrospun nanofibers were deposited on fabric surface to improve barrier efficiency without sacrificing comfort-related properties of the fabrics. Multi-functional nanofibers were fabricated through an electrospinning-electrospraying hybrid process and their ability to detoxify simulants of C-B agents was evaluated. Nanofibers were also deposited onto plasma-pretreated woven fabric substrate through a newly developed plasma-electrospinning hybrid process, to improve the adhesive properties of nanofibers on the fabric surface. The nanofiber adhesion and durability properties were evaluated by peel test, flex and abrasion resistance tests. In this research work, following tasks have been carried out: i) Controlled deposition of nanofiber mat onto woven fabric substrate Electrospun Nylon 6 fiber mats were deposited onto woven 50/50 Nylon/Cotton fabric with the motive of making them into protective material against submicron-level aerosol chemical and biological threats. Polymer solution concentration, electrospinning voltage, and deposition areal density were varied to establish the relationship of processing-structure-filtration efficiency for electrospun fiber mats. A high barrier efficiency of greater than 99.5% was achieved on electrospun fiber mats without sacrificing air permeability and pressure drop. ii) Fabrication and Characterization of Multifunctional ZnO/Nylon 6 nanofibers ZnO/Nylon 6 nanofiber mats were prepared by an electrospinning-electrospraying hybrid process, The electrospinning of polymer solution and electrospraying of ZnO particles were carried out simultaneously such that the ZnO nanoparticles were dispersed on the surface of Nylon 6 nanofibers. The prepared ZnO/Nylon 6 nanofiber mats were tested for detoxifying characteristics against simulants of C-B agents. The results showed that ZnO/Nylon 6 functional nanofiber mats exhibited good detoxification action against paraoxon and have antibacterial efficiency over 99.99% against both the gram-negative E. coli and gram positive B. cereus bacteria. iii) Improving adhesion of electrospun nanofiber mat onto woven fabric by plasma pretreatment of substrate fabric and plasma-electrospinning hybrid process Electrospun nanofibers were deposited onto plasma-pretreated woven fabric to improve the adhesion. In addition, the plasma-electrospinning hybrid process was developed and used in which the nanofibers were subjected to in-situ plasma treatment during electrospinning. The effects of plasma treatement on substrate fabric and electrospun fibers were characterized by water contact angle test, XPS analyses. The improvement of nanofiber adhesive properties on fabric substrate was evaluated by peel test, flex resistance test and abrasion resistance test. The test results showed that the plasma treatment caused introduction of active chemical groups on substrate fabric and electrospun nanofibers. These active chemical assisted in possible cross-linking formation between nanofiber mat and substrate fabric, and this hypothesis was supported by improved adhesion strength, flex resistance and abrasion resistance of nanofiber mat.

Modified Light Duty AM2 Capability Assessment

DTIC Science & Technology

The Modified Light -Duty AM2 matting was designed specifically for lightweight, remote-piloted aircraft (RPA) applications. An in- depth study was... Ratio (CBR) of 6. To understand the full potential of the Modified Light -Duty AM2, a full- scale evaluation was performed with contingency C-17 and...stir welding for use in fabrication of the lightweight RPA matting in conjunction with a full- scale test on the Modified Light -Duty AM2 matting system

Comparative evaluation of recombinant LigB protein and heat-killed antigen-based latex agglutination test with microscopic agglutination test for diagnosis of bovine leptospirosis.

PubMed

Nagalingam, Mohandoss; Thirumalesh, Sushma Rahim Assadi; Kalleshamurthy, Triveni; Niharika, Nakkala; Balamurugan, Vinayagamurthy; Shome, Rajeswari; Sengupta, Pinaki Prasad; Shome, Bibek Ranjan; Prabhudas, Krishnamsetty; Rahman, Habibur

2015-10-01

This study aimed to develop latex agglutination test (LAT) using recombinant leptospiral immunoglobulin-like protein (LigB) (rLigB) antigen and compare its diagnostic efficacy with LAT using conventional heat-killed leptospiral antigen and microscopic agglutination test (MAT) in diagnosing bovine leptospirosis. The PCR-amplified 1053-bp ligB gene sequences from Leptospira borgpetersenii Hardjo serovar were cloned in pET 32 (a) vector at EcoRI and NotI sites and expressed in BL21 E. coli cells as fusion protein with thioredoxin (-57 kDa) and characterized by SDS-PAGE and immunoblot. Out of 390 serum samples [cattle (n = 214), buffaloes (n = 176)] subjected to MAT, 115 samples showed reciprocal titre≥100 up to 1600 against one or more serovars. For recombinant LigB protein/antigen-based LAT, agglutination was observed in the positive sample, while no agglutination was observed in the negative sample. Similarly, heat-killed leptospiral antigen was prepared from and used in LAT for comparison with MAT. A two-sided contingency table was used for analysis of LAT using both the antigens separately against MAT for 390 serum samples. The sensitivity, specificity and positive and negative predictive values of recombinant LigB LAT were found to be 75.65, 91.27, 78.38 and 89.96 %, respectively, and that of heat-killed antigen-based LAT were 72.17, 89.82, 74.77 and 88.53 %, respectively, in comparison with MAT. This developed test will be an alternative/complementary to the existing battery of diagnostic assays/tests for specific detection of pathogenic Leptospira infection in bovine population.

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-mimicking heating phantom. Conclusions MatMRI and MatHIFU leverage existing MRI and MR-HIFU clinical platforms to facilitate pre-clinical research. MatMRI substantially simplifies the real-time acquisition and processing of MR data. MatHIFU facilitates the testing and characterization of new therapy applications using the Philips Sonalleve clinical MR-HIFU system. Under coordination with Philips Healthcare, both MatMRI and MatHIFU are intended to be freely available as open-source software packages to other research groups. PMID:25512856

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.

Development of electrospun beaded fibers from Thai silk fibroin and gelatin for controlled release application.

PubMed

Somvipart, Siraporn; Kanokpanont, Sorada; Rangkupan, Rattapol; Ratanavaraporn, Juthamas; Damrongsakkul, Siriporn

2013-04-01

Thai silk fibroin and gelatin are attractive biomaterials for tissue engineering and controlled release applications due to their biocompatibility, biodegradability, and bioactive properties. The development of electrospun fiber mats from silk fibroin and gelatin were reported previously. However, burst drug release from such fiber mats remained the problem. In this study, the formation of beads on the fibers aiming to be used for the sustained release of drug was of our interest. The beaded fiber mats were fabricated using electrospinning technique by controlling the solution concentration, weight blending ratio of Thai silk fibroin/gelatin blend, and applied voltage. It was found that the optimal conditions including the solution concentration and the weight blending ratio of Thai silk fibroin/gelatin at 8-10% (w/v) and 70/30, respectively, with the applied voltage at 18 kV provided the fibers with homogeneous formation of beads. Then, the beaded fiber mats obtained were crosslinked by the reaction of carbodiimide hydrochloride (EDC)/N-hydroxysuccinimide (NHS). Methylene blue as a model active compound was loaded on the fiber mats. The release test of methylene blue from the beaded fiber mats was carried out in comparison to that of the smooth fiber mats without beads. It was found that the beaded fiber mats could prolong the release of methylene blue, comparing to the smooth fiber mats without beads. This was possibly due to the beaded fiber mats that would absorb and retain higher amount of methylene blue than the fiber mats without beads. Thai silk fibroin/gelatin beaded fiber mats were established as an effective carrier for the controlled release applications. Copyright © 2013 Elsevier B.V. All rights reserved.

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).

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.

Performance Prediction Relationships for AM2 Airfield Matting Developed from Full-Scale Accelerated Testing and Laboratory Experimentation

DTIC Science & Technology

2018-01-01

work, the prevailing methods used to predict the performance of AM2 were based on the CBR design procedure for flexible pavements using a small number...suitable for design and evaluation frameworks currently used for airfield pavements and matting systems. DISCLAIMER: The contents of this report...methods used to develop the equivalency curves equated the mat-surfaced area to an equivalent thickness of flexible pavement using the CBR design

Evaluating five different loci (rbcL, rpoB, rpoC1, matK, and ITS) for DNA barcoding of Indian orchids.

PubMed

Parveen, Iffat; Singh, Hemant K; Malik, Saloni; Raghuvanshi, Saurabh; Babbar, Shashi B

2017-08-01

Orchidaceae, one of the largest families of angiosperms, is represented in India by 1600 species distributed in diverse habitats. Orchids are in high demand owing to their beautiful flowers and therapeutic properties. Overexploitation and habitat destruction have made many orchid species endangered. In the absence of effective identification methods, illicit trade of orchids continues unabated. Considering DNA barcoding as a potential identification tool, species discrimination capability of five loci, ITS, matK, rbcL, rpoB, and rpoC1, was tested in 393 accessions of 94 Indian orchid species belonging to 47 genera, including one listed in Appendix I of CITES and 26 medicinal species. ITS provided the highest species discrimination rate of 94.9%. While, among the chloroplast loci, matK provided the highest species discrimination rate of 85.7%. None of the tested loci individually discriminated 100% of the species. Therefore, multi-locus combinations of up to five loci were tested for their species resolution capability. Among two-locus combinations, the maximum species resolution (86.7%) was provided by ITS+matK. ITS and matK sequences of the medicinal orchids were species specific, thus providing unique molecular identification tags for their identification and detection. These observations emphasize the need for the inclusion of ITS in the core barcode for plants, whenever required and available.

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.

Evaluation and comparison of native and recombinant LipL21 protein-based ELISAs for diagnosis of bovine leptospirosis.

PubMed

Joseph, Siju; Thomas, Naicy; Thangapandian, E; Singh, Vijendra P; Verma, Rishendra; Srivastava, S K

2012-03-01

A 21-kDa leptospiral lipoprotein (LipL21) was evaluated for its diagnostic potential to detect bovine leptospirosis by ELISA. Both native LipL21 (nLipL21) and recombinant LipL21 (rLipL21) proteins were tested and compared regarding diagnostic efficiency, and no statistically significant difference was observed. The sensitivity of rLipL21 ELISA for 62 microscopic agglutination test (MAT) positive sera was 100% and the specificity with 378 MAT negative sera was 97.09%. Thus, rLipL21 protein-based ELISA could be used as an alternative to MAT for the diagnosis of bovine leptospirosis.

Microbial Diversity Analysis of the Bacterial and Archaeal Population in Present Day Stromatolites

NASA Technical Reports Server (NTRS)

Ortega, Maya C.

2011-01-01

Stromatolites are layered sedimentary structures resulting from microbial mat communities that remove carbon dioxide from their environment and biomineralize it as calcium carbonate. Although prevalent in the fossil record, stromatolites are rare in the modem world and are only found in a few locations including Highbome Cay in the Bahamas. The stromatolites found at this shallow marine site are analogs to ancient microbial mat ecosystems abundant in the Precambrian period on ancient Earth. To understand how stromatolites form and develop, it is important to identify what microorganisms are present in these mats, and how these microbes contribute to geological structure. These results will provide insight into the molecular and geochemical processes of microbial communities that prevailed on ancient Earth. Since stromatolites are formed by lithifying microbial mats that are able to mineralize calcium carbonate, understanding the biological mechanisms involved may lead to the development of carbon sequestration technologies that will be applicable in human spaceflight, as well as improve our understanding of global climate and its sustainability. The objective of my project was to analyze the archaeal and bacterial dIversity in stromatolites from Highborn Cay in the Bahamas. The first step in studying the molecular processes that the microorganisms carry out is to ascertain the microbial complexity within the mats, which includes identifying and estimating the numbers of different microbes that comprise these mats.

Calcium Silicate/Chitosan-Coated Electrospun Poly (Lactic Acid) Fibers for Bone Tissue Engineering.

PubMed

Su, Chu-Jung; Tu, Ming-Gene; Wei, Li-Ju; Hsu, Tuan-Ti; Kao, Chia-Tze; Chen, Tsui-Han; Huang, Tsui-Hsien

2017-05-05

Electrospinning technology allows fabrication of nano- or microfibrous fibers with inorganic and organic matrix and it is widely applied in bone tissue engineering as it allows precise control over the shapes and structures of the fibers. Natural bone has an ordered composition of organic fibers with dispersion of inorganic apatite among them. In this study, poly (lactic acid) (PLA) mats were fabricated with electrospinning and coated with chitosan (CH)/calcium silicate (CS) mixer. The microstructure, chemical component, and contact angle of CS/CH-PLA composites were analyzed by scanning electron microscopy, X-ray diffraction, and Fourier transform infrared spectroscopy. In vitro, various CS/CH-coated PLA mats increased the formation of hydroxyapatite on the specimens' surface when soaked in cell cultured medium. During culture, several biological characteristics of the human mesenchymal stem cells (hMSCs) cultured on CS/CH-PLA groups were promoted as compared to those on pure PLA mat. Increased secretion levels of Collagen I and fibronectin were observed in calcium silicate-powder content. Furthermore, with comparison to PLA mats without CS/CH, CS10 and CS15 mats markedly enhanced the proliferation of hMSCs and their osteogenesis properties, which was characterized by osteogenic-related gene expression. These results clearly demonstrated that the biodegradable and electroactive CS/CH-PLA composite mats are an ideal and suitable candidate for bone tissue engineering.

Evaluation of a recombinant LigB protein of Leptospira interrogans serovar Canicola in an enzyme-linked immunosorbent assay for the serodiagnosis of bovine leptospirosis.

PubMed

Sankar, Surya; Harshan, Hiron M; Somarajan, S R; Srivastava, S K

2010-06-01

A recombinant leptospiral lipoprotein, LigB, was evaluated for use in the diagnosis of bovine leptospirosis by enzyme-linked immunosorbent assay (rLigB IgG ELISA). The standard reference test (Microscopic agglutination test, MAT) of 200 serum samples from cattle suspected of leptospirosis showed that 95 (47.5%) samples had positive agglutination titres, which ranged from 100 to 1600. In rLigB IgG ELISA, 49% of the samples were positive. Sensitivity of IgG ELISA for 95 bovine sera, which had MAT titres of greater than or equal to 100, were 100%. ELISA showed a specificity of 97.1% with 105 bovine sera, which were negative at a 1:50 dilution in MAT for Leptospira interrogans serovars. The results of ELISA and MAT correspond very good. When analytical specificity of IgG ELISA was evaluated using bovine serum samples from animals showing the serum antibodies to other pathogens, no cross-reaction was observed. Thus the recombinant LigB IgG ELISA can be used instead of the MAT as an aid to the diagnosis of bovine leptospirosis. Copyright 2009. Published by Elsevier India Pvt Ltd.

Aerodynamic configuration development of the highly maneuverable aircraft technology remotely piloted research vehicle

NASA Technical Reports Server (NTRS)

Gingrich, P. B.; Child, R. D.; Panageas, G. N.

1977-01-01

The aerodynamic development of the highly maneuverable aircraft technology remotely piloted research vehicle (HiMAT/RPRV) from the conceptual design to the final configuration is presented. The design integrates several advanced concepts to achieve a high degree of transonic maneuverability, and was keyed to sustained maneuverability goals while other fighter typical performance characteristics were maintained. When tests of the baseline configuration indicated deficiencies in the technology integration and design techniques, the vehicle was reconfigured to satisfy the subcritical and supersonic requirements. Drag-due-to-lift levels only 5 percent higher than the optimum were obtained for the wind tunnel model at a lift coefficient of 1 for Mach numbers of up to 0.8. The transonic drag rise was progressively lowered with the application of nonlinear potential flow analyses coupled with experimental data.

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

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.

Innovative technologies in course Electrical engineering and electronics

NASA Astrophysics Data System (ADS)

Kuznetsov, E. V.; Kiselev, V. I.; Kulikova, E. A.

2017-11-01

Department of Electrical Engineering and Nondestructive Testing, NRU “MPEI”, has been working on development Electronic Learning Resources (ELRs) in course Electrical Engineering and Electronics for several years. This work have been focused on education intensification and effectiveness while training bachelors in nonelectrical specializations including students from Thermal and Atomic Power Engineering Institute. The developed ELRs are united in a tutorial module consisting of three parts (Electrical Circuits, Electrical Machines, Basics of Electronics): electronic textbook and workbook (ETW); virtual laboratory sessions (VLS); training sessions (ETS); personal tasks (PT); testing system that contains electronic tests in all course subjects and built-in verification of a student’s work results in ETW, VLS, ETS, PT. The report presents samples of different ELRs in html format and MathCAD, MatLAB Simulink applications, copyrighted programs in Java2, Delphi, VB6, C++. The report also contains the experience description, advantages and disadvantages of the new technologies. It is mentioned that ELRs provide new opportunities in course studying.

EVALUATION OF WILDER CONSTRUCTION COMPANY'S MATCON ™ COVER TECHNOLOGY - INNOVATIVE TECHNOLOGY EVALUATION REPORT

EPA Science Inventory

MatCon is a polymer modified asphalt material designed specifically for waste containment applications. The modifications to the material differentiate it from conventional paving asphalt by minimizing the damaging effects of environmental exposure that could detract from the de...

Poly(L-lactide)/halloysite nanotube electrospun mats as dual-drug delivery systems and their therapeutic efficacy in infected full-thickness burns.

PubMed

Zhang, Xiazhi; Guo, Rui; Xu, Jiqing; Lan, Yong; Jiao, Yanpeng; Zhou, Changren; Zhao, Yaowu

2015-11-01

In this study, poly(L-lactide) (PLLA)/halloysite nanotube (HNT) electrospun mats were prepared as a dual-drug delivery system. HNTs were used to encapsulate polymyxin B sulphate (a hydrophilic drug). Dexamethasone (a hydrophobic drug) was directly dissolved in the PLLA solution. The drug-loaded HNTs with optimised encapsulation efficiency were then mixed with the PLLA solution for subsequent electrospinning to form composite dual-drug-loaded fibre mats. The structure, morphology, degradability and mechanical properties of the electrospun composite mats were characterised in detail. The results showed that the HNTs were uniformly distributed in the composite PLLA mats. The HNTs content in the mats could change the morphology and average diameter of the electrospun fibres. The HNTs improved both the tensile strength of the PLLA electrospun mats and their degradation ratio. The drug-release kinetics of the electrospun mats were investigated using ultraviolet-visible spectrophotometry. The HNTs/PLLA ratio could be varied to adjust the release of polymyxin B sulphate and dexamethasone. The antibacterial activity in vitro of the mats was evaluated using agar diffusion and turbidimetry tests, which indicated the antibacterial efficacy of the dual-drug delivery system against Gram-positive and -negative bacteria. Healing in vivo of infected full-thickness burns and infected wounds was investigated by macroscopic observation, histological observation and immunohistochemical staining. The results indicated that the electrospun mats were capable of co-loading and co-delivering hydrophilic and hydrophobic drugs, and could potentially be used as novel antibacterial wound dressings. © The Author(s) 2015.

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.

Elephants know when their bodies are obstacles to success in a novel transfer task

PubMed Central

Dale, Rachel; Plotnik, Joshua M.

2017-01-01

The capacity to recognise oneself as separate from other individuals and objects is difficult to investigate in non-human animals. The hallmark empirical assessment, the mirror self-recognition test, focuses on an animal’s ability to recognise itself in a mirror and success has thus far been demonstrated in only a small number of species with a keen interest in their own visual reflection. Adapting a recent study done with children, we designed a new body-awareness paradigm for testing an animal’s understanding of its place in its environment. In this task, Asian elephants (Elephas maximus) were required to step onto a mat and pick up a stick attached to it by rope, and then pass the stick forward to an experimenter. In order to do the latter, the elephants had to see their body as an obstacle to success and first remove their weight from the mat before attempting to transfer the stick. The elephants got off the mat in the test significantly more often than in controls, where getting off the mat was unnecessary. This task helps level the playing field for non-visual species tested on cognition tasks and may help better define the continuum on which body- and self-awareness lie. PMID:28402335

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.

ECN-14280

NASA Image and Video Library

1980-12-30

The HiMAT (Highly Maneuverable Aircraft Technology) subscale research vehicle, seen here during a research flight, was flown by the NASA Dryden Flight Research Center, Edwards, California, from mid 1979 to January 1983. The aircraft demonstrated advanced fighter technologies that have been used in the development of many modern high performance military aircraft.

ECN-14273

NASA Image and Video Library

1980-12-30

The HiMAT (Highly Maneuverable Aircraft Technology) subscale research vehicle, seen here during a research flight, was flown by the NASA Dryden Flight Research Center, Edwards, California, from mid 1979 to January 1983. The aircraft demonstrated advanced fighter technologies that have been used in the development of many modern high performance military aircraft.

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 cohesion and protection, with active light-dependent turnover by both Cyanobacteria and the heterotrophic community.

Screening cut-stump control of Chinese tallowtree, sweetgum and yaupon with aminocyclopyrachlor

Treesearch

J. L. Yeiser; M. Link; J. Grogan

2012-01-01

Aminocyclopyrachlor (MAT28) was investigated for the potential control of unwanted woody rootstocks of Chinese tallowtree (Triadica sebifera), sweetgum (Liquidambar styraciflua), and yaupon (Ilex vomitoria). A cutstump application of MAT28+Brush and Basal Oil by Helena was tested against standard treatments: (1)...

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

Material-mediated pyrogens in medical devices: Applicability of the in vitro Monocyte Activation Test.

PubMed

Borton, Lindsey K; Coleman, Kelly P

2018-06-14

Pyrogenicity presents a challenge to clinicians, medical device manufactures, and regulators. A febrile response may be caused by endotoxin contamination, microbial components other than endotoxin, or chemical agents that generate a material-mediated pyrogenic response. While test methods for the assessment of endotoxin contamination and some microbial components other than endotoxin are well-established, material-mediated pyrogens remain elusively undefined. This review presents the findings of literature searches conducted to identify material-mediated pyrogens associated with medical devices. The in vivo rabbit pyrogen test (RPT) is considered to be the "gold standard" for medical device pyrogenicity testing, despite the fact that few medical device-derived material-mediated pyrogens are known. In line with global efforts to reduce the use of research animals, an in vitro monocyte activation test (MAT) has the potential to replace the RPT. The MAT is used to detect substances that activate human monocytes to release cytokines. This review will also describe the potential opportunities and challenges associated with MAT adoption for the detection of material-mediated pyrogens in medical device testing.

Reliability and validity of a novel tool to comprehensively assess food and beverage marketing in recreational sport settings.

PubMed

Prowse, Rachel J L; Naylor, Patti-Jean; Olstad, Dana Lee; Carson, Valerie; Mâsse, Louise C; Storey, Kate; Kirk, Sara F L; Raine, Kim D

2018-05-31

Current methods for evaluating food marketing to children often study a single marketing channel or approach. As the World Health Organization urges the removal of unhealthy food marketing in children's settings, methods that comprehensively explore the exposure and power of food marketing within a setting from multiple marketing channels and approaches are needed. The purpose of this study was to test the inter-rater reliability and the validity of a novel settings-based food marketing audit tool. The Food and beverage Marketing Assessment Tool for Settings (FoodMATS) was developed and its psychometric properties evaluated in five public recreation and sport facilities (sites) and subsequently used in 51 sites across Canada for a cross-sectional analysis of food marketing. Raters recorded the count of food marketing occasions, presence of child-targeted and sports-related marketing techniques, and the physical size of marketing occasions. Marketing occasions were classified by healthfulness. Inter-rater reliability was tested using Cohen's kappa (κ) and intra-class correlations (ICC). FoodMATS scores for each site were calculated using an algorithm that represented the theoretical impact of the marketing environment on food preferences, purchases, and consumption. Higher FoodMATS scores represented sites with higher exposure to, and more powerful (unhealthy, child-targeted, sports-related, large) food marketing. Validity of the scoring algorithm was tested through (1) Pearson's correlations between FoodMATS scores and facility sponsorship dollars, and (2) sequential multiple regression for predicting "Least Healthy" food sales from FoodMATS scores. Inter-rater reliability was very good to excellent (κ = 0.88-1.00, p < 0.001; ICC = 0.97, p < 0.001). There was a strong positive correlation between FoodMATS scores and food sponsorship dollars, after controlling for facility size (r = 0.86, p < 0.001). The FoodMATS score explained 14% of the variability in "Least Healthy" concession sales (p = 0.012) and 24% of the variability total concession and vending "Least Healthy" food sales (p = 0.003). FoodMATS has high inter-rater reliability and good validity. As the first validated tool to evaluate the exposure and power of food marketing in recreation facilities, the FoodMATS provides a novel means to comprehensively track changes in food marketing environments that can assist in developing and monitoring the impact of policies and interventions.

EC79-12055

NASA Image and Video Library

1980-01-03

The HiMAT (Highly Maneuverable Aircraft Technology) subscale research vehicle, seen here after landing to conclude a research flight, was flown by the NASA Dryden Flight Research Center, Edwards, California, from mid 1979 to January 1983. The aircraft demonstrated advanced fighter technologies that have been used in the development of many modern high performance military aircraft.

EC80-14281

NASA Image and Video Library

1980-12-30

The HiMAT (Highly Maneuverable Aircraft Technology) subscale research vehicle, seen here during a research flight, was flown by the NASA Dryden Flight Research Center, Edwards, California, from mid 1979 to January 1983. The aircraft demonstrated advanced fighter technologies that have been used in the development of many modern high performance military aircraft.

Utilization of MatPIV program to different geotechnical models

NASA Astrophysics Data System (ADS)

Aklik, P.; Idinger, G.

2009-04-01

The Particle Imaging Velocimetry (PIV) technique is being used to measure soil displacements. PIV has been used for many years in fluid mechanics; but for physical modeling in geotechnical engineering, this technique is still relatively new. PIV is a worldwide growth in soil mechanics over the last decade owing to the developments in digital cameras and laser technologies. The use of PIV is feasible provided the surface contains sufficient texture. A Cambridge group has shown that natural sand contains enough texture for applying PIV. In a texture-based approach, the only requirement is for any patch, big or small to be sufficiently unique so that statistical tracking of this patch is possible. In this paper, some of the soil mechanic's models were investigated such as retaining walls, slope failures, and foundations. The photographs were taken with the help of the high resolution digital camera, the displacements of soils were evaluated with free software named as MatPIV and the displacement graphics between the two images were obtained. Nikon D60 digital camera is 10.2 MB and it has special properties which makes it possible to use in PIV applications. These special properties are Airflow Control System and Image Sensor cleaning for protection against dust, Active D-Lighting for highlighted or shadowy areas while shooting, advanced three-point AF system for fast, efficient and precise autofocus. Its fast and continuous shooting mode enables up to 100 JPEG images at three frames per second. Norm Sand (DIN 1164) was used for all the models in a glass rectangular box. For every experiment, MatPIV was used to calculate the velocities from the two images. MatPIV program was used in two ways such as easy way and difficult way: In the easy way, the two images with 64*64 pixels with 50% or 75% overlap of the interrogation windows were taken into consideration and the calculation was performed with a single iteration through the images and the result consisted of four matrices measured in pixels and pixels/second. At the end of the iteration, the results were visualized. In the application of difficult way of MatPIV, a grid of points into the research model was inserted and the first image was taken with the Nikon D60 digital camera. Afterwards, how large a pixel in the image and the orientation of the coordinate system were calculated. If there are no particles to perform PIV calculations in the investigated region, the best way is to mask out this empty region. The crucial step in PIV is the particle image analysis, which is to determine the displacements between two successive images. The first image was divided into a grid of test patches. Each test patch consisted of a sample of the image matrix of size L * L pixels. To find the displacement of the test patch between images 1 and 2, a search patch was extracted from the second image. The cross-correlation of test patch and search patch was evaluated. The resulting normalized correlation plane indicated the "degree of match" between the test and search patch. The highest peak in the normalized correlation plane indicated the displacement vector of the test patch. The procedure described above for evaluation a single displacement vector was repeated for the entire grid of test patches, producing the displacement field between the image pair. After having performed the calculations, there were so many wild vectors due to low image quality in some parts of the images to be removed with the help of the different filters. There are four different filters in MatPIV, these are: signal-to-noise ratio filter, peak height filter, global filter, and local filter. The filters were used step by step to decide which filter could give the best result for the related images. As a last step, both of the ways were compared in each geotechnical model.

Feasibility and Efficacy of Mat Pilates on People with Mild-to-Moderate Parkinson's Disease: A Preliminary Study.

PubMed

Cancela, Jose Maria; Mollinedo Cardalda, Irimia; Ayán, Carlos; de Oliveira, Iris Machado

2018-04-01

This pilot study aimed at assessing the feasibility and efficacy of a Mat Pilates program in people with mild-to-moderate Parkinson's disease (PD). The participants carried out a Mat Pilates program twice a week for 12 weeks. The Senior Fitness Test battery and the 39-item PD Questionnaire were used to assess the effects of the program on the participants' fitness level and quality of life. A total of 16 patients with mild-to-moderate PD volunteered for and finished the study. The Mat Pilates program proved to be feasible. Adherence to the program was excellent, and no adverse effects were observed. The program had a positive effect on the participants' fitness levels, except for shoulder range of motion and dynamic balance, and on their quality of life. Assessments at follow-up indicated a regression in the improvements obtained by the end of the intervention, even though the sample still showed higher levels of fitness and quality of life than those tested at baseline. Mat Pilates is feasible and may be a beneficial rehabilitation strategy to improve fitness and quality of life in people with mild-to-moderate PD. Future randomized controlled trials might determine the extent of such benefits.

Preferences of dairy cows for three stall surface materials with small amounts of bedding.

PubMed

Norring, M; Manninen, E; de Passillé, A M; Rushen, J; Saloniemi, H

2010-01-01

Farmers' concerns about the economy, cost of labor, and hygiene have resulted in reduced use of organic bedding in stalls for dairy cows; however, the reduced use of organic bedding possibly impairs cow comfort. The effects of different stall surface materials were evaluated in an unheated building in which only a small amount of bedding was used. The lying time and preferences of 18 cows using 3 stall surface materials (concrete, soft rubber mat, and sand) were compared. All materials were lightly bedded with a small amount of straw, and the amount of straw added to each stall was measured. The cows only had access to stalls of one surface type while their lying time was observed. Lying times were longest on the rubber mats compared with other surfaces (rubber mat 768; concrete 727; sand 707+/-16 min/d). In a preference test, cows had access to 2 of the 3 types of stalls for 10 d and their stall preference was measured. Cows preferred stalls with rubber mats to stalls with a concrete floor (median 73 vs. 18 from a total of 160 observations per day; interquartile range was 27 and 12, respectively), but showed no preference for sand stalls compared with stalls with a concrete floor or with rubber mats. More straw was needed on sand stalls compared with concrete or mat (638+/-13 g/d on sand, 468+/-10 g/d on concrete, and 464+/-8 g/d on rubber mats). Lying times on bedded mats indicated that mats were comfortable for the cows. If availability or cost of bedding material requires limiting the amount of bedding used, rubber mats may help maintain cow comfort. Copyright 2010 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Economical and simple production of containerized hardwood seedlings

Treesearch

Merrill C. Hoyle

1982-01-01

An automatic mat-watering system for growing hardwood seedlings in containers was designed and tested. The system has only one moving part, and no electrical requirements. There is no need to calculate different watering schedules for different growth phases, different hardwood species, or different evapotranspiration conditions. Results were excellent with mat...

Dosimetric comparison of 3D conformal, IMRT, and V-MAT techniques for accelerated partial-breast irradiation (APBI)

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

Qiu, Jian-Jian; Department of Radiation Oncology, Fudan University Shanghai Cancer Center, Shanghai; Department of Oncology, Shanghai Medical College, Fudan University, Shanghai

2014-07-01

The purpose is to dosimetrically compare the following 3 delivery techniques: 3-dimensional conformal radiation therapy (3D-CRT), intensity-modulated arc therapy (IMRT), and volumetric-modulated arc therapy (V-MAT) in the treatment of accelerated partial-breast irradiation (APBI). Overall, 16 patients with T1/2N0 breast cancer were treated with 3D-CRT (multiple, noncoplanar photon fields) on the RTOG 0413 partial-breast trial. These cases were subsequently replanned using static gantry IMRT and V-MAT technology to understand dosimetric differences among these 3 techniques. Several dosimetric parameters were used in plan quality evaluation, including dose conformity index (CI) and dose-volume histogram analysis of normal tissue coverage. Quality assurance studies includingmore » gamma analysis were performed to compare the measured and calculated dose distributions. The IMRT and V-MAT plans gave more conformal target dose distributions than the 3D-CRT plans (p < 0.05 in CI). The volume of ipsilateral breast receiving 5 and 10 Gy was significantly less using the V-MAT technique than with either 3D-CRT or IMRT (p < 0.05). The maximum lung dose and the ipsilateral lung volume receiving 10 (V{sub 10}) or 20 Gy (V{sub 20}) were significantly less with both V-MAT and IMRT (p < 0.05). The IMRT technique was superior to 3D-CRT and V-MAT of low dose distributions in ipsilateral lung (p < 0.05 in V{sub 5} and D{sub 5}). The total mean monitor units (MUs) for V-MAT (621.0 ± 111.9) were 12.2% less than those for 3D-CRT (707.3 ± 130.9) and 46.5% less than those for IMRT (1161.4 ± 315.6) (p < 0.05). The average machine delivery time was 1.5 ± 0.2 minutes for the V-MAT plans, 7.0 ± 1.6 minutes for the 3D-CRT plans, and 11.5 ± 1.9 minutes for the IMRT plans, demonstrating much less delivery time for V-MAT. Based on this preliminary study, V-MAT and IMRT techniques offer improved dose conformity as compared with 3D-CRT techniques without increasing dose to the ipsilateral lung. In terms of MU and delivery time, V-MAT is significantly more efficient for APBI than for conventional 3D-CRT and static-beam IMRT.« less

Sensitometric and image analysis of T-grain film.

PubMed

Thunthy, K H; Weinberg, R

1986-08-01

The new Kodak T-grain film is the result of a new technology that makes fast films with high image resolution. The purpose of the investigation was to determine the sensitometric properties and image quality of a T-grain film (T-Mat G) and also to compare this film with a green-sensitive orthochromatic film (Ortho G) and a blue-sensitive film (XRP). The criteria for film evaluation were relative speed, average contrast, exposure latitude, and image resolution. The results showed that the T-Mat G film is twice as fast as the X-Omat RP film and, one and one-third times as fast as the Ortho G film. T-Mat G also produces high resolution and high contrast. This is contrary to the widely held notion that speed is inversely proportional to image quality.

Development of a Continuum Damage Mechanics Material Model of a Graphite-Kevlar(Registered Trademark) Hybrid Fabric for Simulating the Impact Response of Energy Absorbing Kevlar(Registered Trademark) Hybrid Fabric for Simulating the Impact Response of Energy Absorbing

NASA Technical Reports Server (NTRS)

Jackson, Karen E.; Fasanella, Edwin L.; Littell, Justin D.

2017-01-01

This paper describes the development of input properties for a continuum damage mechanics based material model, Mat 58, within LS-DYNA(Registered Trademark) to simulate the response of a graphite-Kevlar(Registered Trademark) hybrid plain weave fabric. A limited set of material characterization tests were performed on the hybrid graphite-Kevlar(Registered Trademark) fabric. Simple finite element models were executed in LS-DYNA(Registered Trademark) to simulate the material characterization tests and to verify the Mat 58 material model. Once verified, the Mat 58 model was used in finite element models of two composite energy absorbers: a conical-shaped design, designated the "conusoid," fabricated of four layers of hybrid graphite-Kevlar(Registered Trademark) fabric; and, a sinusoidal-shaped foam sandwich design, designated the "sinusoid," fabricated of the same hybrid fabric face sheets with a foam core. Dynamic crush tests were performed on components of the two energy absorbers, which were designed to limit average vertical accelerations to 25- to 40-g, to minimize peak crush loads, and to generate relatively long crush stroke values under dynamic loading conditions. Finite element models of the two energy absorbers utilized the Mat 58 model that had been verified through material characterization testing. Excellent predictions of the dynamic crushing response were obtained.

Simulating the Response of a Composite Honeycomb Energy Absorber. Part 2; Full-Scale Impact Testing

NASA Technical Reports Server (NTRS)

Fasanella, Edwin L.; Annett, Martin S.; Jackson, Karen E.; Polanco, Michael A.

2012-01-01

NASA has sponsored research to evaluate an externally deployable composite honeycomb designed to attenuate loads in the event of a helicopter crash. The concept, designated the Deployable Energy Absorber (DEA), is an expandable Kevlar(Registered TradeMark) honeycomb. The DEA has a flexible hinge that allows the honeycomb to be stowed collapsed until needed during an emergency. Evaluation of the DEA began with material characterization of the Kevlar(Registered TradeMark)-129 fabric/epoxy, and ended with a full-scale crash test of a retrofitted MD-500 helicopter. During each evaluation phase, finite element models of the test articles were developed and simulations were performed using the dynamic finite element code, LS-DYNA(Registered TradeMark). The paper will focus on simulations of two full-scale impact tests involving the DEA, a mass-simulator and a full-scale crash of an instrumented MD-500 helicopter. Isotropic (MAT24) and composite (MAT58) material models, which were assigned to DEA shell elements, were compared. Based on simulations results, the MAT58 model showed better agreement with test.

Field Evaluations Test Plan for Validation of Alternative Low-Emission Surface Preparation/Depainting Technologies for Structural Steel

NASA Technical Reports Server (NTRS)

Lewis, Pattie

2005-01-01

Headquarters National Aeronautics and Space Administration (NASA) chartered the Acquisition Pollution Prevention (AP2) Office to coordinate agency activities affecting pollution prevention issues identified during system and component acquisition and sustainment processes. The primary objectives of the AP2 Office are to: (1) Reduce or eliminate the use of hazardous materials (HazMats) or hazardous processes at manufacturing, remanufacturing, and sustainment locations. (2) Avoid duplication of effort in actions required to reduce or eliminate HazMats through joint center cooperation and technology sharing. To achieve a substrate condition suitable for the application of a coating system, both new and old (in-situ) substrates must undergo some type of surface preparation and/or depainting operation to ensure adhesion of the new coating system. The level of cleanliness or anchor profile desired is typically a function of the type of coating to be applied and the specification being adhered to. In high performance environments, cleanliness and surface profile requirements for carbon steel (the dominant substrate for facilities, structures and equipment) dictates the use of abrasive media. Many of the abrasive media currently used across NASA and Air Force Space Command (AFSPC) installations generate large quantities of fugitive particulate emissions and waste. The high quantities of airborne dust and waste generated from these operations pose significant environmental concern. Efforts to contain emissions and the reduce quantity of waste generated have significant implications on project cost; this is often a deterrent to engaging in maintenance activities. In response to recent technological developments and NASA's and AFSPC's need to undertake environmentally conscious corrosion prevention projects, a review of the industry needs to be undertaken to evaluate surface preparation technologies (materials and processes) for embrace. This project will identify, evaluate and approve alternative surface preparation technologies for use at NASA and AFSPC installations. Materials and processes will be evaluated with the goal of selecting those processes that will improve corrosion protection at critical systems, facilitate easier maintenance activity, extend maintenance cycles, eliminate flight hardware contamination and reduce the amount of hazardous waste generated. This Field Evaluations Test Plan defines the field evaluation and testing requirements for validating alternative surface preparation/depainting technologies and supplements the JTP. The field evaluations will be performed at Stennis Space Center, Mississippi, under the oversight of the Project Engineer. Additional field evaluations may be performed at other NASA centers or AFSPC facilities.

Effects of feeding ratio of beet pulp to alfalfa hay or grass hay on ruminal mat characteristics and chewing activity in Holstein dry cows.

PubMed

Izumi, Kenichi; Unno, Chigusa

2010-04-01

The influence of the feeding ratio of a non-forage fiber source and hay on ruminal mat characteristics and chewing activity was evaluated in dairy dry cows. Cows were fed four different diets: the ratios of alfalfa hay (AH) to beet pulp (BP) were 8:2 (dry matter basis, A8B2) and 2:8 (A2B8), and those of grass hay (GH) to BP were 8:2 (G8B2) and 2:8 (G2B8). Total eating time was decreased with increasing BP content (P < 0.01). Total rumination time for AH was shorter than that for GH (P < 0.01), and it decreased with increasing BP content (P < 0.01). The ruminal mat was detected by using a penetration resistance test of the rumen digesta. Penetration resistance value (PRV) of ruminal mat was highest with the G8B2 diet and PRV decreased with increasing BP content (P < 0.05) and feeding AH (P < 0.05). Thickness of the ruminal mat was greater for increasing BP content (P < 0.05). Simple linear regression of ruminal mat PRV on total rumination time resulted in a high positive correlation (r = 0.744; P < 0.001; n = 16). The results demonstrated that increasing the PRV of the ruminal mat stimulated rumination activity and a ruminal mat could be formed, although it was soft even when cows were offered a large quantity of BP.

DNA barcodes for Mexican Cactaceae, plants under pressure from wild collecting.

PubMed

Yesson, Chris; Bárcenas, Rolando T; Hernández, Héctor M; Ruiz-Maqueda, María de la Luz; Prado, Alberto; Rodríguez, Víctor M; Hawkins, Julie A

2011-09-01

DNA barcodes could be a useful tool for plant conservation. Of particular importance is the ability to identify unknown plant material, such as from customs seizures of illegally collected specimens. Mexican cacti are an example of a threatened group, under pressure because of wild collection for the xeriscaping trade and private collectors. Mexican cacti also provide a taxonomically and geographically coherent group with which to test DNA barcodes. Here, we sample the matK barcode for 528 species of Cactaceae including approximately 75% of Mexican species and test the utility of the matK region for species-level identification. We find that the matK DNA barcode can be used to identify uniquely 77% of species sampled, and 79-87% of species of particular conservation importance. However, this is far below the desired rate of 95% and there are significant issues for PCR amplification because of the variability of primer sites. Additionally, we test the nuclear ITS regions for the cactus subfamily Opuntioideae and for the genus Ariocarpus (subfamily Cactoideae). We observed higher rates of variation for ITS (86% unique for Opuntioideae sampled) but a much lower PCR success, encountering significant intra-individual polymorphism in Ariocarpus precluding the use of this marker in this taxon. We conclude that the matK region should provide useful information as a DNA barcode for Cactaceae if the problems with primers can be addressed, but matK alone is not sufficiently variable to achieve species-level identification. Additional complementary regions should be investigated as ITS is shown to be unsuitable. © 2011 Blackwell Publishing Ltd.

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.

Mating Types and Optimum Culture Conditions for Sexual State Formation of Fusarium fujikuroi Isolates

PubMed Central

Kim, Jung-Mi; Hong, Sung Kee; Kim, Wan Gyu; Chun, Se-Chul; Yu, Seung-Hun

2009-01-01

Twenty-five isolates of Fusarium fujikuroi acquired from rice seeds and rice plants evidencing symptoms of Bakanae disease were evaluated to determine their mating types and characterize the formation of their sexual state. The mating types of the isolates were evaluated via multiplex PCR with the diagnostic primers of the mating-type (MAT) region: GFmat1a, GFmat1b, GFmat2c, and GFmat2d. Among the 25 isolates, 11 were identified as MAT-1 (male), and 14 as MAT-2 (female). Four MAT-1 isolates and three MAT-2 isolates were mated and cultured to evaluate the optimal culture conditions for the production of their sexual states. Among four tested media, 10% V8 juice agar proved optimal for the perithecial production of the isolates. The isolates also generated the largest numbers of perithecia when incubated at 23℃ in alternating cycles of 12 hr fluorescent light and NUV fluorescent light and 12 hr darkness. PMID:23983543

Facile and green fabrication of electrospun poly(vinyl alcohol) nanofibrous mats doped with narrowly dispersed silver nanoparticles.

PubMed

Lin, Song; Wang, Run-Ze; Yi, Ying; Wang, Zheng; Hao, Li-Mei; Wu, Jin-Hui; Hu, Guo-Han; He, Hua

2014-01-01

Submicrometer-scale poly(vinyl alcohol) (PVA) nanofibrous mats loaded with aligned and narrowly dispersed silver nanoparticles (AgNPs) are obtained via the electrospinning process from pure water. This facile and green procedure did not need any other chemicals or organic solvents. The doped AgNPs are narrowly distributed, 4.3±0.7 nm and their contents on the nanofabric mats can be easily tuned via in situ ultraviolet light irradiation or under preheating conditions, but with different particle sizes and size distributions. The morphology, loading concentrations, and dispersities of AgNPs embedded within PVA nanofiber mats are characterized by transmission electron microscopy, scanning electron microscopy, energy dispersive X-ray spectroscopy, ultraviolet-visible spectra, X-ray photoelectron spectroscopy, and X-ray diffraction, respectively. Moreover, the biocidal activities and cytotoxicity of the electrospun nanofiber mats are determined by zone of inhibition, dynamic shaking method, and cell counting kit (CCK)-8 assay tests.

Chitosan-rectorite nanospheres immobilized on polystyrene fibrous mats via alternate electrospinning/electrospraying techniques for copper ions adsorption

NASA Astrophysics Data System (ADS)

Tu, Hu; Huang, Mengtian; Yi, Yang; Li, Zhenshun; Zhan, Yingfei; Chen, Jiajia; Wu, Yang; Shi, Xiaowen; Deng, Hongbing; Du, Yumin

2017-12-01

Chitosan (CS), as a kind of well characterized biopolymer, has been used for heavy metal adsorption due to its low cost and high efficacy. However, when used directly, chitosan particles had small surface area and weak mechanical strength which is unfavorable to metal adsorption and reused. Besides, it cannot be easily recycled that may cause a secondary pollution. In this paper, CS and layered silicate rectorite (REC) were fully mixed and the mixtures were subsequently electrosprayed nano-sized spheres, which were immobilized on the surface of electrospun polystyrene (PS) mats for metal adsorption. The morphology analysis taken from SEM confirmed that CS-REC nanospheres were loaded on the surface of PS fibrous mats. Small Angle X-ray diffraction patterns showed that the interlayer distance of REC in composite mats was enlarged by the intercalation of CS chains; such structure meant bigger surface area which was helpful for metal adsorption. The data of contact angle implied that PS mats coated with CS-REC nanospheres exhibited better hydrophilicity than PS mats, which was conductive to adsorption rate. Besides, the copper ions adsorption of composite mats was tested at different conditions including the adsorption time, the initial pH and the initial concentration of copper ion. The results demonstrated that PS mats coated with CS-REC nanospheres had the adsorption capacity up to 134 mg/g. In addition, the addition of REC containing Ca2+ could also improve the metal adsorption because of cation exchange. The desorption assay indicated that PS mats immobilized with CS and CS-REC still kept high adsorption ability which retained 74% and 78% after three adsorption-desorption cycles.

Assessing universality of DNA barcoding in geographically isolated selected desert medicinal species of Fabaceae and Poaceae

PubMed Central

Hussain, Fatma; Ahmed, Nisar; Ghorbani, Abdolbaset

2018-01-01

In pursuit of developing fast and accurate species-level molecular identification methods, we tested six DNA barcodes, namely ITS2, matK, rbcLa, ITS2+matK, ITS2+rbcLa, matK+rbcLa and ITS2+matK+rbcLa, for their capacity to identify frequently consumed but geographically isolated medicinal species of Fabaceae and Poaceae indigenous to the desert of Cholistan. Data were analysed by BLASTn sequence similarity, pairwise sequence divergence in TAXONDNA, and phylogenetic (neighbour-joining and maximum-likelihood trees) methods. Comparison of six barcode regions showed that ITS2 has the highest number of variable sites (209/360) for tested Fabaceae and (106/365) Poaceae species, the highest species-level identification (40%) in BLASTn procedure, distinct DNA barcoding gap, 100% correct species identification in BM and BCM functions of TAXONDNA, and clear cladding pattern with high nodal support in phylogenetic trees in both families. ITS2+matK+rbcLa followed ITS2 in its species-level identification capacity. The study was concluded with advocating the DNA barcoding as an effective tool for species identification and ITS2 as the best barcode region in identifying medicinal species of Fabaceae and Poaceae. Current research has practical implementation potential in the fields of pharmaco-vigilance, trade of medicinal plants and biodiversity conservation. PMID:29576968

Evaluation of Faun MLC-70 Trackway Mat System Under Simulated F-15 Traffic

DTIC Science & Technology

2014-05-01

stronger soils. Results of traffic tests presented herein include individual mat panel properties, pretest and posttest sub- grade soil conditions, subgrade...strength of the subgrade had changed during the evaluation. The average pretest and posttest CBR measurements for each item are shown in Table 3... Pretest A1 25.2 50 A2 33.3 60 A3 30.9 35 Posttest A1 12.5 10 -12.7 -40 A2 18.5 15 -14.8 -45 A3 12.8 30 -18.1 -5 2.3.1.2 Mat

BrucellaCapt versus classical tests in the serological diagnosis and management of human brucellosis.

PubMed

Casanova, Aurora; Ariza, Javier; Rubio, Manuel; Masuet, Cristina; Díaz, Ramón

2009-06-01

The BrucellaCapt test is an immunocapture agglutination test suggested as a possible substitute for the Coombs test in the diagnosis of human brucellosis. Here it is compared with classical tests using 321 samples from 48 patients with brucellosis (6.9 +/- 1.7 samples per patient), including 20 patients with focal disease and 8 patients with a total of 9 relapse episodes (mean follow-up, 18 months). The BrucellaCapt test was used according to the manufacturer's instructions, and we also used a variant of the BrucellaCapt test in which the microtiter plates were not coated with antibodies against total human immunoglobulin (BCAPV). The correlation between the BrucellaCapt and BCAPV tests was 0.982 (P < 0.001), with 260 coincident pairs of titers (81%). The areas under the receiver operating characteristic curve for the BrucellaCapt and BCAPV tests with respect to the Coombs test were 0.969 and 0.960, respectively. Upon admission, the BrucellaCapt, BCAPV, and Coombs tests and the microagglutination test (MAT) were positive for all cases: titers were 1/2,560 by the BrucellaCapt test, 1/2,560 by the BCAPV test, 1/1,280 by the Coombs test, and 1/320 by the MAT. The decreases in the BrucellaCapt and BCAPV titers over time were pronounced in comparison with the Coombs titers. Cumulative probabilities of persistence 12 months after therapy were as follows: 80% by the BrucellaCapt test, 80% by the BCAPV test, 87% by the Coombs test, and 35% by the MAT. Serological changes during relapse were detected in seven cases (88%) by the Coombs test, in five cases by the BrucellaCapt and BCAPV tests, and in three cases by the MAT. The BrucellaCapt test is a sensitive, specific, and simple test for routine use in human brucellosis. Similar results were obtained with the BCAPV test. However, in some cases of relapse and chronic forms of the disease, the slight changes observed in low-affinity antibodies alone are better detected by the Coombs test.

How Important Are Rats As Vectors of Leptospirosis in the Mekong Delta of Vietnam?

PubMed Central

Loan, Hoang Kim; Van Cuong, Nguyen; Takhampunya, Ratree; Kiet, Bach Tuan; Campbell, James; Them, Lac Ngoc; Bryant, Juliet E.; Tippayachai, Bousaraporn; Van Hoang, Nguyen; Morand, Serge; Hien, Vo Be

2015-01-01

Abstract Leptospirosis is a zoonosis known to be endemic in the Mekong Delta of Vietnam, even though clinical reports are uncommon. We investigated leptospira infection in rats purchased in food markets during the rainy season (October) (n=150), as well as those trapped during the dry season (February–March) (n=125) in the region using RT-PCR for the lipL32 gene, confirmed by 16S rRNA, as well as by the microscopic agglutination test (MAT). Results were compared with the serovar distribution of human cases referred from Ho Chi Minh City hospitals (2004–2012) confirmed by MAT (n=45). The MAT seroprevalence among rats was 18.3%. The highest MAT seroprevalence corresponded, in decreasing order, to: Rattus norvegicus (33.0%), Bandicota indica (26.5%), Rattus tanezumi (24.6%), Rattus exulans (14.3%), and Rattus argentiventer (7.1%). The most prevalent serovars were, in descending order: Javanica (4.6% rats), Lousiana (4.2%), Copenageni (4.2%), Cynopterie (3.7%), Pomona (2.9%), and Icterohaemorrhagiae (2.5%). A total of 16 rats (5.8%) tested positive by RT-PCR. Overall, larger rats tended to have a higher prevalence of detection. There was considerable agreement between MAT and PCR (kappa=0.28 [0.07–0.49]), although significantly more rats were positive by MAT (McNemar 29.9 (p<0.001). MAT prevalence was higher among rats during the rainy season compared with rats in the dry season. There are no current available data on leptospira serovars in humans in the Mekong Delta, although existing studies suggest limited overlapping between human and rat serovars. Further studies should take into account a wider range of potential reservoirs (i.e., dogs, pigs) as well as perform geographically linked co-sampling of humans and animals to establish the main sources of leptospirosis in the region. PMID:25629781

How important are rats as vectors of leptospirosis in the Mekong Delta of Vietnam?

PubMed

Loan, Hoang Kim; Van Cuong, Nguyen; Takhampunya, Ratree; Kiet, Bach Tuan; Campbell, James; Them, Lac Ngoc; Bryant, Juliet E; Tippayachai, Bousaraporn; Van Hoang, Nguyen; Morand, Serge; Hien, Vo Be; Carrique-Mas, Juan J

2015-01-01

Leptospirosis is a zoonosis known to be endemic in the Mekong Delta of Vietnam, even though clinical reports are uncommon. We investigated leptospira infection in rats purchased in food markets during the rainy season (October) (n=150), as well as those trapped during the dry season (February-March) (n=125) in the region using RT-PCR for the lipL32 gene, confirmed by 16S rRNA, as well as by the microscopic agglutination test (MAT). Results were compared with the serovar distribution of human cases referred from Ho Chi Minh City hospitals (2004-2012) confirmed by MAT (n=45). The MAT seroprevalence among rats was 18.3%. The highest MAT seroprevalence corresponded, in decreasing order, to: Rattus norvegicus (33.0%), Bandicota indica (26.5%), Rattus tanezumi (24.6%), Rattus exulans (14.3%), and Rattus argentiventer (7.1%). The most prevalent serovars were, in descending order: Javanica (4.6% rats), Lousiana (4.2%), Copenageni (4.2%), Cynopterie (3.7%), Pomona (2.9%), and Icterohaemorrhagiae (2.5%). A total of 16 rats (5.8%) tested positive by RT-PCR. Overall, larger rats tended to have a higher prevalence of detection. There was considerable agreement between MAT and PCR (kappa=0.28 [0.07-0.49]), although significantly more rats were positive by MAT (McNemar 29.9 (p<0.001). MAT prevalence was higher among rats during the rainy season compared with rats in the dry season. There are no current available data on leptospira serovars in humans in the Mekong Delta, although existing studies suggest limited overlapping between human and rat serovars. Further studies should take into account a wider range of potential reservoirs (i.e., dogs, pigs) as well as perform geographically linked co-sampling of humans and animals to establish the main sources of leptospirosis in the region.

Molecular Ecology of Hypersaline Microbial Mats: Current Insights and New Directions.

PubMed

Wong, Hon Lun; Ahmed-Cox, Aria; Burns, Brendan Paul

2016-01-05

Microbial mats are unique geobiological ecosystems that form as a result of complex communities of microorganisms interacting with each other and their physical environment. Both the microorganisms present and the network of metabolic interactions govern ecosystem function therein. These systems are often found in a range of extreme environments, and those found in elevated salinity have been particularly well studied. The purpose of this review is to briefly describe the molecular ecology of select model hypersaline mat systems (Guerrero Negro, Shark Bay, S'Avall, and Kiritimati Atoll), and any potentially modulating effects caused by salinity to community structure. In addition, we discuss several emerging issues in the field (linking function to newly discovered phyla and microbial dark matter), which illustrate the changing paradigm that is seen as technology has rapidly advanced in the study of these extreme and evolutionally significant ecosystems.

Mechanical characterization of glass fiber (woven roving/chopped strand mat E-glass fiber) reinforced polyester composites

NASA Astrophysics Data System (ADS)

Bhaskar, V. Vijaya; Srinivas, Kolla

2017-07-01

Polymer reinforced composites have been replacing most of the engineering material and their applications become more and more day by day. Polymer composites have been analyzing from past thirty five years for their betterment for adapting more applications. This paper aims at the mechanical properties of polyester reinforced with glass fiber composites. The glass fiber is reinforced with polyester in two forms viz Woven Rovings (WRG) and Chopped Strand Mat (CSMG) E-glass fibers. The composites are fabricated by hand lay-up technique and the composites are cut as per ASTM Standard sizes for corresponding tests like flexural, compression and impact tests, so that flexural strength, compression strength, impact strength and inter laminar shear stress(ILSS) of polymer matrix composites are analyzed. From the tests and further calculations, the polyester composites reinforced with Chopped Strand Mat glass fiber have shown better performance against flexural load, compression load and impact load than that of Woven Roving glass fiber.

Assessment of Bioremediation Technologies: Focus on Technologies Suitable for Field-Level Demonstrations and Applicable to DoD Contaminants.

DTIC Science & Technology

1995-06-01

include leachate collection systems and some form of aeration. The reactor is set up on an impermeable liner to prevent contaminant migration. Treatment...Bioremediation Microbial Mats Phytoremediation /construc- ted wetlands White Rot Fungus Full scale commercial technology for treatment of hydro...validation Phytoremediation / Constructed Wetlands Some scaled up batch demonstrations. Primarily laboratory scale. White Rot Fungus Pilot scale

Smart pillow for heart-rate monitoring using a fiber optic sensor

NASA Astrophysics Data System (ADS)

Chen, Zhihao; Teo, Ju Teng; Ng, Soon Huat; Yim, Huiqing

2011-03-01

In this paper, we propose and demonstrate a new method to monitor heart rate using fiber optic microbending based sensor for in-bed non-intrusive monitoring. The sensing system consists of transmitter, receiver, sensor mat, National Instrument (NI) data acquisition (DAQ) card and a computer for signal processing. The sensor mat is embedded inside a commercial pillow. The heart rate measurement system shows an accuracy of +/-2 beats, which has been successfully demonstrated in a field trial. The key technological advantage of our system is its ability to measure heart rate with no preparation and minimal compliance by the patient.

Evaluation of recombinant LigB antigen-based indirect ELISA and latex agglutination test for the serodiagnosis of bovine leptospirosis in India.

PubMed

Deneke, Yosef; Sabarinath, T; Gogia, Neha; Lalsiamthara, Jonathan; Viswas, K N; Chaudhuri, Pallab

2014-08-01

Leptospirosis is a zoonotic disease caused by pathogenic spirochetes of the genus Leptospira, causing febrile infection characterized by multi-organ failure in humans and animals. Leptospiral Ig-like protein B (LigB) is a surface-expressed antigen that mediates host cell invasion or attachment. In this study, N-terminal conserved region of LigB protein (46 kDa) was evaluated for its diagnostic potential to detect anti-leptospiral antibodies in the sera of various animal species. Dot blot analysis revealed immunoreactivity of Leptospira-positive sera of cattle, buffalo, dog, sheep and goat to purified LigB protein. We have analyzed 1126 bovine serum samples, collected from Northern and Eastern part of India, by microscopic agglutination test (MAT) and recombinant LigB (rLigB) based ELISA and latex agglutination test (LAT). The sensitivity of rLigB based ELISA for 554 MAT positive sera was 96.9% and the specificity with 572 MAT negative sera was 91.08% whereas LAT showed sensitivity and specificity of 93.68% and 92.31%, respectively. Kappa values of 0.879 and 0.860 for recombinant antigen based ELISA and LAT indicate excellent agreement with the gold standard serological test, MAT, for the detection of anti-leptospiral antibodies in sera. Further, LAT based on rLigB antigen is a simple and rapid test, suitable for serodiagnosis of leptospirosis under field conditions, owing to its portability and longer shelf life. Copyright © 2014 Elsevier Ltd. All rights reserved.

Micro-hybrid electric vehicle application of valve-regulated lead-acid batteries in absorbent glass mat technology: Testing a partial-state-of-charge operation strategy

NASA Astrophysics Data System (ADS)

Schaeck, S.; Stoermer, A. O.; Hockgeiger, E.

The BMW Group has launched two micro-hybrid functions in high volume models in order to contribute to reduction of fuel consumption in modern passenger cars. Both the brake energy regeneration (BER) and the auto-start-stop function (ASSF) are based on the conventional 14 V vehicle electrical system and current series components with only little modifications. An intelligent control algorithm of the alternator enables recuperative charging in braking and coasting phases, known as BER. By switching off the internal combustion engine at a vehicle standstill the idling fuel consumption is effectively reduced by ASSF. By reason of economy and package a lead-acid battery is used as electrochemical energy storage device. The BMW Group assembles valve-regulated lead-acid (VRLA) batteries in absorbent glass mat (AGM) technology in the micro-hybrid electrical power system since special challenges arise for the batteries. By field data analysis a lower average state-of-charge (SOC) due to partial state-of-charge (PSOC) operation and a higher cycling rate due to BER and ASSF are confirmed in this article. Similar to a design of experiment (DOE) like method we present a long-term lab investigation. Two types of 90 Ah VRLA AGM batteries are operated with a test bench profile that simulates the micro-hybrid vehicle electrical system under varying conditions. The main attention of this lab testing is focused on capacity loss and charge acceptance over cycle life. These effects are put into context with periodically refresh charging the batteries in order to prevent accelerated battery aging due to hard sulfation. We demonstrate the positive effect of refresh chargings concerning preservation of battery charge acceptance. Furthermore, we observe moderate capacity loss over 90 full cycles both at 25 °C and at 3 °C battery temperature.

Long-term antibody responses of cats fed toxoplasma gondii tissue cysts.

PubMed

Dubey, J P; Lappin, M R; Thulliez, P

1995-12-01

As part of a long-term study on immunity to oocyst shedding, 12 4-6-mo-old cats were inoculated orally with tissue cysts of the ME-49 strain (6 cats) or the TS-2 strain (6 cats) of Toxoplasma gondii. Two cats fed the ME-49 strain died or were killed because of acute toxoplasmosis 12 and 13 days after inoculation (DAI), respectively. On day 39 after primary infection, 5 cats (2 infected with the ME-49 strain and 3 infected with the TS-2 strain) were challenged orally with tissue cysts of the ME-49 strain. One cat died following rechallenge infection due to causes unrelated to toxoplasmosis. Seventy-seven months after primary infection, the remaining 9 cats were challenged orally with tissue cysts of the P89 strain of T. gondii. Blood samples were obtained weekly or monthly and sera were analyzed for antibodies to T. gondii using the modified agglutination test (MAT), the Sabin-Feldman dye test (DT), and the enzyme-linked immunosorbent assay (ELISA) for IgM (IgM-ELISA) or IgG (IgG-ELISA). The MAT was performed using both formalin-fixed (FF) and acetone-fixed (AF) tachyzoites. The MAT (FF) was the most sensitive test; cats seroconverted within 14 DAI and high titers (> 10,000) persisted > 6 yr, although cats had no clinical signs. The MAT titers using the AF detected recent exposure and titers declined sharply after 2 mo postinoculation. DT and ELISA titers were lower and developed slower than MAT titers. Fluctuations in antibody titers were limited to 8-fold during the 6-yr observation period. Anamnestic serum antibody responses were seen in 2 cats after the final challenge, but not after first challenge.

Evaluation of the diagnostic value of serologic microagglutination testing and a polymerase chain reaction assay for diagnosis of acute leptospirosis in dogs in a referral center.

PubMed

Fraune, Claudia Kümmerle; Schweighauser, Ariane; Francey, Thierry

2013-05-15

To determine the diagnostic value of a serologic microagglutination test (MAT) and a PCR assay on urine and blood for the diagnosis of leptospirosis in dogs with acute kidney injury (AKI). Cross-sectional study. Animals-76 dogs with AKI in a referral hospital (2008 to 2009). Dogs' leptospirosis status was defined with a paired serologic MAT against a panel of 11 Leptospira serovars as leptospirosis-associated (n = 30) or nonleptospirosis-associated AKI (12). In 34 dogs, convalescent serologic testing was not possible, and leptospirosis status was classified as undetermined. The diagnostic value of the MAT single acute or convalescent blood sample was determined in dogs in which leptospirosis status could be classified. The diagnostic value of a commercially available genus-specific PCR assay was evaluated by use of 36 blood samples and 20 urine samples. Serologic acute testing of an acute blood sample had a specificity of 100% (95% CI, 76% to 100%), a sensitivity of 50% (33% to 67%), and an accuracy of 64% (49% to 77%). Serologic testing of a convalescent blood sample had a specificity of 92% (65% to 99%), a sensitivity of 100% (87% to 100%), and an accuracy of 98% (88% to 100%). Results of the Leptospira PCR assay were negative for all samples from dogs for which leptospirosis status could be classified. Serologic MAT results were highly accurate for diagnosis of leptospirosis in dogs, despite a low sensitivity for early diagnosis. In this referral setting of dogs pretreated with antimicrobials, testing of blood and urine samples with a commercially available genus-specific PCR assay did not improve early diagnosis.

Evaluation of Material Models within LS-DYNA(Registered TradeMark) for a Kevlar/Epoxy Composite Honeycomb

NASA Technical Reports Server (NTRS)

Polanco, Michael A.; Kellas, Sotiris; Jackson, Karen

2009-01-01

The performance of material models to simulate a novel composite honeycomb Deployable Energy Absorber (DEA) was evaluated using the nonlinear explicit dynamic finite element code LS-DYNA(Registered TradeMark). Prototypes of the DEA concept were manufactured using a Kevlar/Epoxy composite material in which the fibers are oriented at +/-45 degrees with respect to the loading axis. The development of the DEA has included laboratory tests at subcomponent and component levels such as three-point bend testing of single hexagonal cells, dynamic crush testing of single multi-cell components, and impact testing of a full-scale fuselage section fitted with a system of DEA components onto multi-terrain environments. Due to the thin nature of the cell walls, the DEA was modeled using shell elements. In an attempt to simulate the dynamic response of the DEA, it was first represented using *MAT_LAMINATED_COMPOSITE_FABRIC, or *MAT_58, in LS-DYNA. Values for each parameter within the material model were generated such that an in-plane isotropic configuration for the DEA material was assumed. Analytical predictions showed that the load-deflection behavior of a single-cell during three-point bending was within the range of test data, but predicted the DEA crush response to be very stiff. In addition, a *MAT_PIECEWISE_LINEAR_PLASTICITY, or *MAT_24, material model in LS-DYNA was developed, which represented the Kevlar/Epoxy composite as an isotropic elastic-plastic material with input from +/-45 degrees tensile coupon data. The predicted crush response matched that of the test and localized folding patterns of the DEA were captured under compression, but the model failed to predict the single-cell three-point bending response.

A field operational test on valve-regulated lead-acid absorbent-glass-mat batteries in micro-hybrid electric vehicles. Part I. Results based on kernel density estimation

NASA Astrophysics Data System (ADS)

Schaeck, S.; Karspeck, T.; Ott, C.; Weckler, M.; Stoermer, A. O.

2011-03-01

In March 2007 the BMW Group has launched the micro-hybrid functions brake energy regeneration (BER) and automatic start and stop function (ASSF). Valve-regulated lead-acid (VRLA) batteries in absorbent glass mat (AGM) technology are applied in vehicles with micro-hybrid power system (MHPS). In both part I and part II of this publication vehicles with MHPS and AGM batteries are subject to a field operational test (FOT). Test vehicles with conventional power system (CPS) and flooded batteries were used as a reference. In the FOT sample batteries were mounted several times and electrically tested in the laboratory intermediately. Vehicle- and battery-related diagnosis data were read out for each test run and were matched with laboratory data in a data base. The FOT data were analyzed by the use of two-dimensional, nonparametric kernel estimation for clear data presentation. The data show that capacity loss in the MHPS is comparable to the CPS. However, the influence of mileage performance, which cannot be separated, suggests that battery stress is enhanced in the MHPS although a battery refresh function is applied. Anyway, the FOT demonstrates the unsuitability of flooded batteries for the MHPS because of high early capacity loss due to acid stratification and because of vanishing cranking performance due to increasing internal resistance. Furthermore, the lack of dynamic charge acceptance for high energy regeneration efficiency is illustrated. Under the presented FOT conditions charge acceptance of lead-acid (LA) batteries decreases to less than one third for about half of the sample batteries compared to new battery condition. In part II of this publication FOT data are presented by multiple regression analysis (Schaeck et al., submitted for publication [1]).

Advanced sampling techniques for hand-held FT-IR instrumentation

NASA Astrophysics Data System (ADS)

Arnó, Josep; Frunzi, Michael; Weber, Chris; Levy, Dustin

2013-05-01

FT-IR spectroscopy is the technology of choice to identify solid and liquid phase unknown samples. The challenging ConOps in emergency response and military field applications require a significant redesign of the stationary FT-IR bench-top instruments typically used in laboratories. Specifically, field portable units require high levels of resistance against mechanical shock and chemical attack, ease of use in restrictive gear, extreme reliability, quick and easy interpretation of results, and reduced size. In the last 20 years, FT-IR instruments have been re-engineered to fit in small suitcases for field portable use and recently further miniaturized for handheld operation. This article introduces the HazMatID™ Elite, a FT-IR instrument designed to balance the portability advantages of a handheld device with the performance challenges associated with miniaturization. In this paper, special focus will be given to the HazMatID Elite's sampling interfaces optimized to collect and interrogate different types of samples: accumulated material using the on-board ATR press, dispersed powders using the ClearSampler™ tool, and the touch-to-sample sensor for direct liquid sampling. The application of the novel sample swipe accessory (ClearSampler) to collect material from surfaces will be discussed in some detail. The accessory was tested and evaluated for the detection of explosive residues before and after detonation. Experimental results derived from these investigations will be described in an effort to outline the advantages of this technology over existing sampling methods.

Promoting physical activity with a school-based dance mat exergaming intervention: qualitative findings from a natural experiment.

PubMed

Burges Watson, Duika; Adams, Jean; Azevedo, Liane B; Haighton, Catherine

2016-07-20

Physical activity is critical to improving health and well-being in children. Quantitative studies have found a decline in activity in the transition from primary to secondary education. Exergames (active video games) might increase physical activity in adolescents. In January 2011 exergame dance mat systems were introduced in to all secondary schools across two local authority districts in the UK. We performed a quasi-experimental evaluation of a natural experiment using a mixed methods design. The quantitative findings from this work have been previously published. The aim of this linked qualitative study was to explore the implementation of the dance mat scheme and offer insights into its uptake as a physical activity intervention. Embedded qualitative interviews at baseline and 12 month follow-up with purposively selected physical education teachers (n = 20) and 25 focus groups with a convenience sample of pupils (n = 120) from five intervention schools were conducted. Analysis was informed by sociology of translation approach. At baseline, participants (both teachers and pupils) reported different expectations about the dance mats and how they could be employed. Variation in use was seen at follow-up. In some settings they were frequently used to engage hard to reach groups of pupils. Overall, the dance mats were not used routinely to increase physical activity. However there were other unanticipated benefits to pupils such as improved reaction time, co-ordination and mathematic skills. The use of dance mats was limited in routine physical education classes because of contextual issues (school/government policy) technological failures (batteries/updates) and because of expectations about how and where they could be used. Our linked quantitative study (previously published) suggested that the dance mats were not particularly effective in increasing physical activity, but the qualitative results (reported here) show that the dance mats were not used routinely enough to show a significant effect on physical activity of the intervention. This research demonstrates the benefit of using mixed methods to evaluate complex physical activity interventions. Those planning any intervention for promoting physical activity in schools need to understand the distinction between physical activity and physical education.

Molecular manipulation of the mating-type system and development of a new approach for characterizing pathogen virulence in Pyrenophora tritici-repentis

USDA-ARS?s Scientific Manuscript database

The ascomycete Pyrenophora tritici-repentis (Ptr) is an important fungal pathogen worldwide that causes tan spot of wheat. The fungus is self-fertile because each isolate contains both mating type (MAT) idiomorphs. In this work, we developed knockouts of the MAT genes in Ptr and tested fertility of ...

The Search for Life on Mars Using Macroscopically Visible Microbial Mats (Stromatolites) in 3.5 3.3 Ga Cherts from the Pilbara in Australia and Barberton in South Africa as Analogues

NASA Astrophysics Data System (ADS)

Westall, F.; Hofmann, B.; Brack, A.

2004-03-01

Microbial mats from early terrestrial environments can be macroscopically visible and represent excellent analogues in the search for life on Mars. Tests using the Beagle 2 camera show that they can be observed by in situ instrumentation.

A hetero-core fiber optic smart mat sensor for discrimination between a moving human and object on temporal loss peaks

NASA Astrophysics Data System (ADS)

Hosoki, Ai; Nishiyama, Michiko; Choi, Yongwoon; Watanabe, Kazuhiro

2011-05-01

In this paper, we propose discrimination method between a moving human and object by means of a hetero-core fiber smart mat sensor which induces the optical loss change in time. In addition to several advantages such as flexibility, thin size and resistance to electro-magnetic interference for a fiber optic sensor, a hetero-core fiber optic sensor is sensitive to bending action of the sensor portion and independent of temperature fluctuations. Therefore, the hetero-core fiber thin mat sensor can have a fewer sensing portions than the conventional floor pressure sensors, furthermore, can detect the wide area covering the length of strides. The experimental results for human walking tests showed that the mat sensors were reproducibly working in real-time under limiting locations the foot passed in the mat sensor. Focusing on the temporal peak numbers in the optical loss, human walking and wheeled platform moving action induced the peak numbers in the range of 1 - 3 and 5 - 7, respectively, for the 10 persons including 9 male and 1 female. As a result, we conclude that the hetero-core fiber mat sensor is capable of discriminating between the moving human and object such as a wheeled platform focusing on the peak numbers in the temporal optical loss.

A pilot study on the improvement of the lying area of finishing pigs by a soft lying mat.

PubMed

Savary, Pascal; Gygax, Lorenz; Jungbluth, Thomas; Wechsler, Beat; Hauser, Rudolf

2011-01-01

In this pilot study, we tested whether a soft mat (foam covered with a heat-sealed thermoplastic) reduces alterations and injuries at the skin and the leg joints.The soft mat in the lying area of partly slatted pens was compared to a lying area consisting of either bare or slightly littered (100 g straw per pig and day) concrete flooring. In this study we focused on skin lesions on the legs of finishing pigs as indicators of impaired welfare. Pigs were kept in 19 groups of 8-10 individuals and were examined for skin lesions around the carpal and tarsal joints either at a weight of <35 kg, or at close to 100 kg. The likelihood of hairless patches and wounds at the tarsal joints was significantly lower in pens with the soft lying mat than in pens with a bare concrete floor. Pens with a littered concrete floor did not differ compared to pens with a bare concrete floor. The soft lying mat thus improved floor quality in the lying area in terms of preventing skin lesions compared to bare and slightly littered concrete flooring. Such soft lying mats have thus the potential to improve lying comfort and welfare of finishing pigs.

Micropatterned coculture of vascular endothelial and smooth muscle cells on layered electrospun fibrous mats toward blood vessel engineering.

PubMed

Li, Huinan; Liu, Yaowen; Lu, Jinfu; Wei, Jiaojun; Li, Xiaohong

2015-06-01

A major challenge in vascular engineering is the establishment of proper microenvironment to guide the spatial organization, growth, and extracellular matrix (ECM) productions of cells found in blood vessels. In the current study, micropatterned fibrous mats with distinct ridges and grooves of different width were created to load smooth muscle cells (SMCs), which were assembled by stacking on vascular endothelial cell (EC)-loaded flat fibrous mats to mimic the in vivo-like organized structure of blood vessels. SMCs were mainly distributed in the ridges, and aligned fibers in the patterned regions led to the formation of elongated cell bodies, intense actin filaments, and expressions of collagen I and α-smooth muscle actin in a parallel direction with fibers. ECs spread over the flat fibrous mats and expressed collagen IV and laminin with a cobblestone-like feature. A z-stack scanning of fluorescently stained fibrous mats indicated that SMCs effectively infiltrated into fibrous scaffolds at the depth of around 200 μm. Compared with SMCs cultured alone, the coculture with ECs enhanced the proliferation, infiltration, and cytoskeleton elongation of SMCs on patterned fibrous mats. Although the coculture of SMCs made no significant difference in the EC growth, the coculture system on patterned fibrous scaffolds promoted ECM productions of both ECs and SMCs. Thus, this patterned fibrous configuration not only offers a promising technology in the design of tissue engineering scaffolds to construct blood vessels with durable mechanical properties, but also provides a platform for patterned coculture to investigate cell-matrix and cell-cell interactions in highly organized tissues. © 2014 Wiley Periodicals, Inc.

Generation of selectable marker-free transgenic eggplant resistant to Alternaria solani using the R/RS site-specific recombination system.

PubMed

Darwish, Nader Ahmed; Khan, Raham Sher; Ntui, Valentine Otang; Nakamura, Ikuo; Mii, Masahiro

2014-03-01

Marker-free transgenic eggplants, exhibiting enhanced resistance to Alternaria solani , can be generated on plant growth regulators (PGRs)- and antibiotic-free MS medium employing the multi-auto-transformation (MAT) vector, pMAT21 - wasabi defensin , wherein isopentenyl transferase ( ipt ) gene is used as a positive selection marker. Use of the selection marker genes conferring antibiotic or herbicide resistance in transgenic plants has been considered a serious problem for environment and the public. Multi-auto-transformation (MAT) vector system has been one of the tools to excise the selection marker gene and produce marker-free transgenic plants. Ipt gene was used as a selection marker gene. Wasabi defensin gene, isolated from Wasabia japonica (a Japanese horseradish which has been a potential source of antimicrobial proteins), was used as a gene of interest. Wasabi defensin gene was cloned from the binary vector, pEKH-WD, to an ipt-type MAT vector, pMAT21, by gateway cloning technology and transferred to Agrobacterium tumefaciens strain EHA105. Infected cotyledon explants of eggplant were cultured on PGRs- and antibiotic-free MS medium. Extreme shooty phenotype/ipt shoots were produced by the explants infected with the pMAT21-wasabi defensin (WD). The same PGRs- and antibiotic-free MS medium was used in subcultures of the ipt shoots. Subsequently, morphologically normal shoots emerged from the Ipt shoots. Molecular analyses of genomic DNA from transgenic plants confirmed the integration of the WD gene and excision of the selection marker (ipt gene). Expression of the WD gene was confirmed by RT-PCR and Northern blot analyses. In vitro whole plant and detached leaf assay of the marker-free transgenic plants exhibited enhanced resistance against Alternaria solani.

Academic performance, career potential, creativity, and job performance: can one construct predict them all?

PubMed

Kuncel, Nathan R; Hezlett, Sarah A; Ones, Deniz S

2004-01-01

This meta-analysis addresses the question of whether 1 general cognitive ability measure developed for predicting academic performance is valid for predicting performance in both educational and work domains. The validity of the Miller Analogies Test (MAT; W. S. Miller, 1960) for predicting 18 academic and work-related criteria was examined. MAT correlations with other cognitive tests (e.g., Raven's Matrices [J. C. Raven, 1965]; Graduate Record Examinations) also were meta-analyzed. The results indicate that the abilities measured by the MAT are shared with other cognitive ability instruments and that these abilities are generalizably valid predictors of academic and vocational criteria, as well as evaluations of career potential and creativity. These findings contradict the notion that intelligence at work is wholly different from intelligence at school, extending the voluminous literature that supports the broad importance of general cognitive ability (g).

Associations of soft flooring materials in free stalls with milk yield, clinical mastitis, teat lesions, and removal of dairy cows.

PubMed

Ruud, L E; Bøe, K E; Osterås, O

2010-04-01

The objective was to test if there was an association between free-stall base softness and milk yield, incidence of clinical mastitis (CM), teat lesions, and removal of cows. In a questionnaire sent to 1,923 dairy farms presumed to be using free-stall housing, farmers were asked for information regarding housing and stall base; for example, the year of installation and the product name or brand of their mats or mattresses. This information was merged with data for milk yield, CM, teat lesions, and removal of cows extracted from the Norwegian Dairy Herd Recording System for the years after installation of mats or mattresses. After exclusion of invalid contributions, the data set consisted of 29,326 lactations for milk yield distributed over 363 free-stalled herds in Norway. The farms were stratified into 5 categories according to the softness of the stall surface measured as millimeter impact of a sphere with a diameter of 120 mm at 2-kN load: 1=concrete, softness of 0mm; 2=rubber, softness of 1 to 8mm; 3=soft mats, softness of 9 to 16 mm; 4=multilayer mats, softness of 17 to 24 mm; and 5=mattresses, softness over 24 mm. Lactation curves were estimated as modified Wood's lactation curves using test-day data and mixed models with repeated measurements, adjusting for days in milk, parity, and softness of free-stall flooring. Herds on concrete free-stall bases yielded 6,727+/-146 kg of milk from 5 to 305 days in milk. In comparison, herds showed a decrease of 0.3% on rubber, an increase of 2.4% on soft mats, an increase of 4.5% on multilayer mats, and an increase of 3.9% on mattresses. Compared with concrete, the hazard ratio (HR) of CM was less on rubber, multilayer mats, and mattresses [HR=0.89 (0.79-0.99), 0.85 (0.73-0.996), and 0.80 (0.73-0.88), respectively]. Compared with concrete, the HR of teat lesions was less on rubber, soft mats, multilayer mats, and mattresses [HR=0.41 (0.26-0.65), 0.33 (0.24-0.44), 0.12 (0.04-0.38), and 0.47 (0.33-0.67), respectively]. The HR of removal of cows was less on mattresses compared with concrete, rubber, soft mats, and multilayer mats, with HR=0.90 (0.84-0.97), 0.88 (0.80-0.97), 0.86 (0.80-0.93), and 0.85 (0.76-0.95), respectively. A soft free-stall base contributed significantly to increased milk yield and fewer incidences of CM, teat lesions, and removal of cows. Copyright (c) 2010 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Maté drinking and esophageal squamous cell carcinoma in South America: pooled results from two large multicenter case-control studies.

PubMed

Lubin, Jay H; De Stefani, Eduardo; Abnet, Christian C; Acosta, Gisele; Boffetta, Paolo; Victora, Cesar; Graubard, Barry I; Muñoz, Nubia; Deneo-Pellegrini, Hugo; Franceschi, Silvia; Castellsagué, Xavier; Ronco, Alvaro L; Dawsey, Sanford M

2014-01-01

Maté tea is a nonalcoholic infusion widely consumed in southern South America, and may increase risk of esophageal squamous cell carcinoma (ESCC) and other cancers due to polycyclic aromatic hydrocarbons (PAH) and/or thermal injury. We pooled two case-control studies: a 1988 to 2005 Uruguay study and a 1986 to 1992 multinational study in Argentina, Brazil, Paraguay, and Uruguay, including 1,400 cases and 3,229 controls. We computed ORs and fitted a linear excess OR (EOR) model for cumulative maté consumption in liters/day-year (LPDY). The adjusted OR for ESCC with 95% confidence interval (CI) by ever compared with never use of maté was 1.60 (1.2-2.2). ORs increased linearly with LPDY (test of nonlinearity; P = 0.69). The estimate of slope (EOR/LPDY) was 0.009 (0.005-0.014) and did not vary with daily intake, indicating maté intensity did not influence the strength of association. EOR/LPDY estimates for consumption at warm, hot, and very hot beverage temperatures were 0.004 (-0.002-0.013), 0.007 (0.003-0.013), and 0.016 (0.009-0.027), respectively, and differed significantly (P < 0.01). EOR/LPDY estimates were increased in younger (<65) individuals and never alcohol drinkers, but these evaluations were post hoc, and were homogeneous by sex. ORs for ESCC increased linearly with cumulative maté consumption and were unrelated to intensity, so greater daily consumption for shorter duration or lesser daily consumption for longer duration resulted in comparable ORs. The strength of association increased with higher maté temperatures. Increased understanding of cancer risks with maté consumption enhances the understanding of the public health consequences given its purported health benefits.

Benchscale Assessment of the Efficacy of a Reactive Core Mat to Isolate PAH-spiked Aquatic Sediments.

PubMed

Meric, Dogus; Barbuto, Sara; Sheahan, Thomas C; Shine, James P; Alshawabkeh, Akram N

2014-01-01

This paper describes the results of a benchscale testing program to assess the efficacy of a reactive core mat (RCM) for short term isolation and partial remediation of contaminated, subaqueous sediments. The 1.25 cm thick RCM (with a core reactive material such as organoclay with filtering layers on top and bottom) is placed on the sediment, and approximately 7.5 - 10 cm of overlying soil is placed on the RCM for stability and protection. A set of experiments were conducted to measure the sorption characteristics of the mat core (organoclay) and sediment used in the experiments, and to determine the fate of semi-volatile organic contaminants and non-reactive tracers through the sediment and reactive mat. The experimental study was conducted on naphthalene-spiked Neponset River (Milton, MA) sediment. The results show nonlinear sorption behavior for organoclay, with sorption capacity increasing with increasing naphthalene concentration. Neponset River sediment showed a notably high sorption capacity, likely due to the relatively high organic carbon fraction (14%). The fate and transport experiments demonstrated the short term efficiency of the reactive mat to capture the contamination that is associated with the post-capping period during which the highest consolidation-induced advective flux occurs, driving solid particles, pore fluid and soluble contaminants toward the reactive mat. The goal of the mat placement is to provide a physical filtering and chemically reactive layer to isolate contamination from the overlying water column. An important finding is that because of the high sorption capacity of the Neponset River sediment, the physical filtering capability of the mat is as critical as its chemical reactive capacity.

Clinical audit and national survey on the assessment of collateral circulation before radial forearm free flap harvest.

PubMed

Abdullakutty, Anwer; Bajwa, Mandeep S; Patel, Sonum; D'Souza, Jacob

2017-01-01

Controversy exists regarding the use of Duplex Ultrasound (DUS) in addition to the Modified Allen's Test (MAT) for the assessment of collateral circulation prior to elevation of the Radial Forearm Free Flap (RFFF). A survey amongst members of BAOMS Head & Neck Oncology Subspecialty Interest Group and a completed local audit was undertaken to assess the need for DUS. Data for the initial audit was collected retrospectively between 2010 and 2013. Both MAT and DUS was performed routinely during this period. The results of the survey and initial audit led to a change in practice and DUS was no longer requested. The re-audit was performed prospectively between 2013 and 2015. The results of the survey showed that all respondents performed MAT. DUS was performed 'always' by 40%, 'sometimes' by 13.3% and 'never' by 46.7%. A total of 41 patients were included in the initial audit, 6 had an abnormal DUS but only 1 had an abnormal MAT. Five cases had an abnormal DUS but normal MAT and went on to have their ipsilateral RFFF raised without ischaemic complications. The patient with an abnormal MAT had their contralateral RFFF raised. No patients suffered ischaemic complications during the initial audit. A total of 48 patients were included in the re-audit 2 of which had an abnormal MAT and their contralateral RFFF raised. No patients suffered ischaemic complications during the re-audit. In conclusion, routine use of DUS did not provide any additional information above the MAT in identifying patients at risk of ischaemic complications. Copyright © 2016 European Association for Cranio-Maxillo-Facial Surgery. All rights reserved.

History of medication-assisted treatment and its association with initiating others into injection drug use in San Diego, CA.

PubMed

Mittal, Maria Luisa; Vashishtha, Devesh; Sun, Shelly; Jain, Sonia; Cuevas-Mota, Jazmine; Garfein, Richard; Strathdee, Steffanie A; Werb, Dan

2017-10-03

Medication-assisted treatment (MAT) remains the gold standard for the treatment of opioid use disorder. MAT also reduces the frequency of injecting among people who inject drugs (PWID). Relatedly, data suggest that PWID play a key role in the initiation of others into drug injecting by exposing injecting practices to injection-naïve drug users. Our primary objective was to test whether a history of MAT enrollment is associated with a reduced odds of PWID providing injection initiation assistance. Preventing Injecting by Modifying Existing Responses (PRIMER; NIDA DP2-DA040256-01), is a multi-site cohort study assessing the impact of socio-structural factors on the risk that PWID provide injection initiation assistance. Data were drawn from a participating cohort of PWID in San Diego, CA. The primary outcome was reporting ever providing injection initiation assistance; the primary predictor was reporting ever being enrolled in MAT. Logistic regression was used to model associations between MAT enrollment and ever initiating others into injecting while adjusting for potential confounders. Participants (n = 354) were predominantly male (n = 249, 70%). Thirty-eight percent (n = 135) of participants reported ever initiating others into injection drug use. In multivariate analysis, participants who reported a history of MAT enrollment had significantly decreased odds of ever providing injection initiation assistance (Adjusted Odds Ratio [AOR]: 0.62, 95% Confidence Interval [CI]: 0.39-0.99). These preliminary findings suggest an association between MAT enrollment and a lower odds that male PWID report providing injection initiation assistance to injection-naïve drug users. Further research is needed to identify the pathways by which MAT enrollment may impact the risk that PWID initiate others into drug injecting.

The Perils They Face: Using Key Texts to Prepare Passionate Teachers for an Unfriendly World

ERIC Educational Resources Information Center

Shrock, Randall

2004-01-01

The administrators at Earlham College wanted teachers who entered its M.A.T. program to develop a "fire in the belly" to teach, and to have the ability to confront the realities of U. S. schools, including standardized testing (which seems at odds with passionate teaching and learning). Prior to entering the Earlham College M.A.T. program,…

Testing the Efficacy of DNA Barcodes for Identifying the Vascular Plants of Canada.

PubMed

Braukmann, Thomas W A; Kuzmina, Maria L; Sills, Jesse; Zakharov, Evgeny V; Hebert, Paul D N

2017-01-01

Their relatively slow rates of molecular evolution, as well as frequent exposure to hybridization and introgression, often make it difficult to discriminate species of vascular plants with the standard barcode markers (rbcL, matK, ITS2). Previous studies have examined these constraints in narrow geographic or taxonomic contexts, but the present investigation expands analysis to consider the performance of these gene regions in discriminating the species in local floras at sites across Canada. To test identification success, we employed a DNA barcode reference library with sequence records for 96% of the 5108 vascular plant species known from Canada, but coverage varied from 94% for rbcL to 60% for ITS2 and 39% for matK. Using plant lists from 27 national parks and one scientific reserve, we tested the efficacy of DNA barcodes in identifying the plants in simulated species assemblages from six biogeographic regions of Canada using BLAST and mothur. Mean pairwise distance (MPD) and mean nearest taxon distance (MNTD) were strong predictors of barcode performance for different plant families and genera, and both metrics supported ITS2 as possessing the highest genetic diversity. All three genes performed strongly in assigning the taxa present in local floras to the correct genus with values ranging from 91% for rbcL to 97% for ITS2 and 98% for matK. However, matK delivered the highest species discrimination (~81%) followed by ITS2 (~72%) and rbcL (~44%). Despite the low number of plant taxa in the Canadian Arctic, DNA barcodes had the least success in discriminating species from this biogeographic region with resolution ranging from 36% with rbcL to 69% with matK. Species resolution was higher in the other settings, peaking in the Woodland region at 52% for rbcL and 87% for matK. Our results indicate that DNA barcoding is very effective in identifying Canadian plants to a genus, and that it performs well in discriminating species in regions where floristic diversity is highest.

Testing the Efficacy of DNA Barcodes for Identifying the Vascular Plants of Canada

PubMed Central

Kuzmina, Maria L.; Sills, Jesse; Zakharov, Evgeny V.; Hebert, Paul D. N.

2017-01-01

Their relatively slow rates of molecular evolution, as well as frequent exposure to hybridization and introgression, often make it difficult to discriminate species of vascular plants with the standard barcode markers (rbcL, matK, ITS2). Previous studies have examined these constraints in narrow geographic or taxonomic contexts, but the present investigation expands analysis to consider the performance of these gene regions in discriminating the species in local floras at sites across Canada. To test identification success, we employed a DNA barcode reference library with sequence records for 96% of the 5108 vascular plant species known from Canada, but coverage varied from 94% for rbcL to 60% for ITS2 and 39% for matK. Using plant lists from 27 national parks and one scientific reserve, we tested the efficacy of DNA barcodes in identifying the plants in simulated species assemblages from six biogeographic regions of Canada using BLAST and mothur. Mean pairwise distance (MPD) and mean nearest taxon distance (MNTD) were strong predictors of barcode performance for different plant families and genera, and both metrics supported ITS2 as possessing the highest genetic diversity. All three genes performed strongly in assigning the taxa present in local floras to the correct genus with values ranging from 91% for rbcL to 97% for ITS2 and 98% for matK. However, matK delivered the highest species discrimination (~81%) followed by ITS2 (~72%) and rbcL (~44%). Despite the low number of plant taxa in the Canadian Arctic, DNA barcodes had the least success in discriminating species from this biogeographic region with resolution ranging from 36% with rbcL to 69% with matK. Species resolution was higher in the other settings, peaking in the Woodland region at 52% for rbcL and 87% for matK. Our results indicate that DNA barcoding is very effective in identifying Canadian plants to a genus, and that it performs well in discriminating species in regions where floristic diversity is highest. PMID:28072819

Mast cell activation test in the diagnosis of allergic disease and anaphylaxis.

PubMed

Bahri, Rajia; Custovic, Adnan; Korosec, Peter; Tsoumani, Marina; Barron, Martin; Wu, Jiakai; Sayers, Rebekah; Weimann, Alf; Ruiz-Garcia, Monica; Patel, Nandinee; Robb, Abigail; Shamji, Mohamed H; Fontanella, Sara; Silar, Mira; Mills, E N Clare; Simpson, Angela; Turner, Paul J; Bulfone-Paus, Silvia

2018-03-05

Food allergy is an increasing public health issue and the most common cause of life-threatening anaphylactic reactions. Conventional allergy tests assess for the presence of allergen-specific IgE, significantly overestimating the rate of true clinical allergy and resulting in overdiagnosis and adverse effect on health-related quality of life. To undertake initial validation and assessment of a novel diagnostic tool, we used the mast cell activation test (MAT). Primary human blood-derived mast cells (MCs) were generated from peripheral blood precursors, sensitized with patients' sera, and then incubated with allergen. MC degranulation was assessed by means of flow cytometry and mediator release. We compared the diagnostic performance of MATs with that of existing diagnostic tools to assess in a cohort of peanut-sensitized subjects undergoing double-blind, placebo-controlled challenge. Human blood-derived MCs sensitized with sera from patients with peanut, grass pollen, and Hymenoptera (wasp venom) allergy demonstrated allergen-specific and dose-dependent degranulation, as determined based on both expression of surface activation markers (CD63 and CD107a) and functional assays (prostaglandin D 2 and β-hexosaminidase release). In this cohort of peanut-sensitized subjects, the MAT was found to have superior discrimination performance compared with other testing modalities, including component-resolved diagnostics and basophil activation tests. Using functional principle component analysis, we identified 5 clusters or patterns of reactivity in the resulting dose-response curves, which at preliminary analysis corresponded to the reaction phenotypes seen at challenge. The MAT is a robust tool that can confer superior diagnostic performance compared with existing allergy diagnostics and might be useful to explore differences in effector cell function between basophils and MCs during allergic reactions. Copyright © 2018 The Authors. Published by Elsevier Inc. All rights reserved.

Technology development for phosphoric acid fuel cell powerplant, phase 2

NASA Technical Reports Server (NTRS)

Christner, L.

1981-01-01

The development of materials, cell components, and reformers for on site integrated energy systems is described. Progress includes: (1) heat-treatment of 25 sq cm, 350 sq cm and 1200 sq cm cell test hardware was accomplished. Performance of fuel cells is improved by using this material; (2) electrochemical and chemical corrosion rates of heat-treated and as-molded graphite/phenolic resin composites in phosphoric acid were determined; (3) three cell, 5 in. x 15 in. stacks operated for up to 10,000 hours and 12 in. x 17 in. five cell stacks were tested for 5,000 hours; (4) a three cell 5 in. x 15 in. stack with 0.12 mg Pt/sq cm anodes and 0.25 mg Pt/sq cm cathodes was operated for 4,500 hours; and (5) an ERC proprietary high bubble pressure matrix, MAT-1, was tested for up to 10,000 hours.

Characterization and in vitro evaluation of electrospun chitosan/polycaprolactone blend fibrous mat for skin tissue engineering.

PubMed

Prasad, Tilak; Shabeena, E A; Vinod, D; Kumary, T V; Anil Kumar, P R

2015-01-01

The electrospinning technique allows engineering biomimetic scaffolds within micro to nanoscale range mimicking natural extracellular matrix (ECM). Chitosan (CS) and polycaprolactone (PCL) were dissolved in a modified solvent mixture consisting of formic acid and acetone (3:7) and mixed in different weight ratios to get chitosan-polycaprolactone [CS-PCL] blend solutions. The CS-PCL blend polymer was electrospun in the same solvent system and compared with PCL. The physicochemical characterization of the electrospun fibrous mats was done using scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), tensile test, swelling properties, water contact angle (WCA) analysis, surface profilometry and thermo gravimetric analysis (TGA). The CS-PCL fibrous mat showed decreased hydrophobicity. The CS-PCL mats also showed improved swelling property, tensile strength, thermal stability and surface roughness. The cytocompatibility of the CS-PCL and PCL fibrous mats were examined using mouse fibroblast (L-929) cell line by direct contact and cellular activity with extract of materials confirmed non-cytotoxic nature. The potential of CS-PCL and PCL fibrous mats as skin tissue engineering scaffolds were assessed by cell adhesion, viability, proliferation and actin distribution using human keratinocytes (HaCaT) and L-929 cell lines. Results indicate that CS-PCL is a better scaffold for attachment and proliferation of keratinocytes and is a potential material for skin tissue engineering.

Production of thick uniform-coating films containing rectorite on nanofibers through the use of an automated coating machine.

PubMed

Wu, Yang; Li, Xueyong; Shi, Xiaowen; Zhan, Yingfei; Tu, Hu; Du, Yumin; Deng, Hongbing; Jiang, Linbin

2017-01-01

When an efficient automated coating machine is used to process layer-by-layer (LBL) deposited nanofibrous mats, it causes an obvious planar effect on the surface of the mats, which can be eliminated through ultimate immersion. During this process, chitosan (CS) - rectorite (REC) intercalated composite films are built on the surface of cellulose acetate (CA) nanofibrous mats by a coating machine. Then, the immersion process is utilized to allow positively charged CS or CS-REC intercalated composites to uniformly assemble on the surface of negatively charged CA nanofibers. An investigation into the morphology of the resultant scaffolds confirms that the uniquely small pore size, high specific surface area and typically three-dimensional (3D) structure of nanofibrous mats remain present. The results of Fourier transform infrared (FT-IR) and X-ray photoelectron spectroscopy (XPS) indicate that it is feasible to assemble nanofibrous mats using a coating machine. The intercalated structure of CS-REC is confirmed by the results of small-angle X-ray diffraction (SAXRD) and wide-angle X-ray diffraction (WAXRD). The results of the cell experiment and antibacterial test demonstrate that the addition of REC not only has little impact on the cytocompatibility of the mats but also enhances their ability to inhibit bacteria. Copyright © 2016 Elsevier B.V. All rights reserved.

Usage of Leptospira spp. local strains as antigens increases the sensitivity of the serodiagnosis of bovine leptospirosis.

PubMed

Pinto, Priscila S; Loureiro, Ana P; Penna, Bruno; Lilenbaum, Walter

2015-09-01

Leptospirosis is a zoonotic disease that occurs worldwide, particularly in tropical countries. In livestock the agent is responsible for reproductive problems such as infertility and abortion. Serogroup Sejroe, particularly serovar Hardjo, prevails in cattle in several regions. The microscopic agglutination test (MAT) is the current method for diagnosing leptospirosis. It has been proposed that the inclusion of local strains could detect a larger set of seroreactive animals. In that context, the aim of the present study was to evaluate if the usage of local strains as antigens increases the sensitivity of the serodiagnosis of bovine leptospirosis. Blood and urine samples were collected from 314 bovines from several herds randomly selected in a slaughterhouse in Rio de Janeiro, Brazil. Serological diagnosis was made with MAT using a 21 reference-strains panel (MAT21). Additionally, 12 local strains (MAT33) were included as antigens. PCR was performed with the urine samples and it was positive on 71 out of 222 samples (31.9%). MAT21 identified as seroreactive 173 (55.1%) out of the 314 animals studied, with Sejroe the most common (38.1%). In MAT33, 204 (65.0%) animals were seroreactive with a significant increase on seroreactivity (9.9%). In conclusion, MAT presented with a significant increase of sensitivity when local strains were used as antigens. Among the local strains, 2013_U152 (KP263062) (serogroup Shermani) and 2013_U280 (KP263069) (serogroup Grippotyphosa) showed to be more antigenic. Copyright © 2015. Published by Elsevier B.V.

Biogeochemistry of Stinking Springs, Utah. Part II: Microbial Diversity and Photo- and Chemo-Autotrophic Growth Rates in a Layered Microbial Mat

NASA Astrophysics Data System (ADS)

Monteverde, D.; Metzger, J. G.; Bournod, C.; Kelly, H.; Johnson, H.; Sessions, A. L.; Osburn, M.; Shapiro, R. S.; Rideout, J.; Johnston, D. T.; Stevenson, B.; Stamps, B. W.; Vuono, D.; Hanselmann, K.; Spear, J. R.

2013-12-01

Layered microbial mats have garnered attention for their high phylogenetic diversity and exploitation of geochemical gradients often on the mm scale. However, despite their novelty and implications for early life diversification, little is known about layered microbial mat growth rates or the interdependence of the microbial communities within the system. Stinking Springs, a warm, sulfidic, saline spring northeast of the Great Salt Lake, serves as our test-site to investigate some of these questions. Stinking Springs undergoes downstream changes in pH (6.59-8.14), sulfide (527μM - below detection), sulfate (13-600μM), TCO2 (7.77-3.71mM), and temperature (40-21°C) along its ~150m flow path. The first 10m of discharge is channelized, beyond that, the spring supports a 10 to 40mm-thick layered microbial mat covering ~40% of the total spring runoff area. The mat was divided into four texturally-distinct layers which were each analyzed for 16S rRNA, lipid abundance, and bicarbonate and acetate uptake rates in addition to standard microscopy analyses. 16S rRNA analyses confirmed high taxa diversity within each layer, which varied significantly in taxa makeup such that no single phylum dominated the abundance (>33%) in more than one mat layer. The taxonomic diversity tended to increase with mat depth, a similar finding to other studies on layered microbial mats. A mat sampling transect across 16 meters showed that layer taxonomic diversity was conserved horizontally for all four mat layers, which implies mat depth has a larger control on diversity than physical or chemical parameters. Microscopy indicated the presence of diatoms in all layers which was confirmed by lipid abundance of sterols and long-branch fatty acid methyl esters. Incubation experiments were conducted in light and dark conditions over 24 hours with separate 13C-tagged bicarbonate and acetate additions. Heterotrophic growth rates (acetate uptake; 0.03-0.65%/day) were higher than autotrophic growth rates (bicarbonate uptake; 0-0.16%/day) under both dark and light conditions. Light conditions yielded higher growth rates for both heterotrophs and autotrophs and the highest rates were consistently found in the top mat layer and decreased with depth. The addition of 13C-acetate and concomitant high uptake is a measure of potential heterotrophy since in situ acetate concentrations are unlikely to be as high. 13C-bicarbonate uptake, on the other hand, should quantitatively represent the autotrophic growth rate. The Stinking Spring layered microbial mats display high taxonomic diversity, which is conserved horizontally across distances of meters and varies significantly with depth. Mats experience highest growth in the surface layer likely driven by phototrophs; high rates of bicarbonate uptake in the dark indicate considerable chemoautotrophy. Covariation in the heterotroph growth rates and 16S rRNA heterotroph abundance with mat depth indicates that heterotrophy may play an important role in the growth of these layered mats.

Report: EPA Needs to Improve Its Information Technology Audit Follow-Up Processes

EPA Pesticide Factsheets

Report #16-P-0100, March 10, 2016. The EPA’s audit follow-up oversight for offices reviewed did not ensure that agreed-to corrective actions were managed effectively in the agency’s Management Audit Tracking System (MATS).

Progress in the development of lightweight nickel electrode

NASA Technical Reports Server (NTRS)

Britton, Doris L.

1992-01-01

The use of the lightweight nickel electrode, in place of the heavy-sintered state-of-the-art nickel electrode, will lead to improvements in specific energy and performance of the nickel-hydrogen cell. Preliminary testing indicates that a nickel fiber mat is a promising support candidate for the nickel hydroxide active material. Nickel electrodes made from fiber mats, with nickel and cobalt powder added to the fiber, were tested at LeRC. To date, over 8000 cycles have been accumulated, at 40 percent depth-of-discharge, using the lightweight fiber electrode, in a boiler plate nickel-hydrogen cell.

Electrospun nanofiber-based thermite textiles and their reactive properties.

PubMed

Yan, Shi; Jian, Guoqiang; Zachariah, Michael R

2012-12-01

In this work, we present a first time fabrication of thermite-based nanofiber mats with a nitrocellulose composite energetic binder to create a new class of energetic 1D nanocomposite. The as prepared thermite based nanofibrous mats were characterized and tested for their burning behavior, and compared with the pure nitrocellulose and nanoaluminum incorporated nanofibers for their combustion performances. Thermite-based nanofibers show enhanced burning rates in combustion tests, which correlate to the mass loading of nanothermite relative to binder in nanofibers. The electrospinning method demonstrates the possibility of avoiding some of the problems associated with melt casting nanometalized propellants.

WORKERS FABRICATE ROOF SLABS FOR MTR BUILDING AT THE CONSTRUCTION ...

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

WORKERS FABRICATE ROOF SLABS FOR MTR BUILDING AT THE CONSTRUCTION SITE. FORMS WERE MADE OF STEEL. AFTER AN INCH OF CONCRETE HAD BEEN POURED IN THE FORM, A MAT OF REINFORCING STEEL WAS PLACED ON IT. THE REMAINDER OF THE FORM WAS FILLED, AND THE CONCRETE WAS VIBRATED, STRUCK, AND TROWELED. GROOVES AT CORNER WILL HAVE 1/4 INCH RODS WELDED INTO THE EYE OF THE STEEL MAT FOR GROUNDING. INL NEGATIVE NO. 578. Unknown Photographer, 9/1/1950 - Idaho National Engineering Laboratory, Test Reactor Area, Materials & Engineering Test Reactors, Scoville, Butte County, ID

Photo-assisted generation of phospholipid polymer substrates for regiospecific protein conjugation and control of cell adhesion.

PubMed

Tanaka, Masako; Iwasaki, Yasuhiko

2016-08-01

Novel photo-reactive phospholipid polymers were synthesized for use in the preparation of nonfouling surfaces with protein conjugation capacity. Poly[2-methacryloyloxyethyl phosphorylcholine (MPC)-ran-N-methacryloyl-(l)-tyrosinemethylester (MAT)] (P(MPC/MAT)) was synthesized by conventional radical polymerization, with the MAT units capable of being oxidized by 254nm UV irradiation. Because of this photo-oxidation, active species such as catechol and quinone were alternately generated in the copolymer. A silicon wafer was subjected to surface modification through spin coating of P(MPC/MAT) from an aqueous solution for use as a model substrate. The surface was then irradiated several times with UV light. The thickness of the polymer layers formed on the Si wafers was influenced by various parameters such as polymer concentration, UV irradiation time, and composition of the MAT units in P(MPC/MAT). Oxidized MAT units were advantageous not only for polymer adhesion to a solid surface but also for protein conjugation with the adhered polymers. The amount of protein immobilized on UV-irradiated P(MPC/MAT) was dependent on the composition of the MAT units in the polymer. Furthermore, it was confirmed that protein immobilization on the polymer occurred through the oxidized MAT units because the protein adsorption was significantly reduced upon blocking these units through pretreatment with glycine. Conjugation of regiospecific protein could also be achieved through the use of a photomask. In addition, nonspecific protein adsorption was reduced on the non-irradiated regions whose surface was covered with physisorbed P(MPC/MAT). Therefore, P(MPC/MAT) can be used in the preparation of nonfouling substrates, which enable micrometer-sized manipulation of proteins through photo-irradiation. Function of proteins immobilized on MPC copolymers was also confirmed by cell adhesion test. As such, photo-reactive MPC copolymers are suitable for performing controlled protein conjugation and preparing polymer-protein hybrid platforms for use in biomedical and diagnostic devices. Novel photo-reactive phospholipid polymers have been synthesized for immobilization on solid surfaces and regiospecific protein conjugation. Tyrosine residues embedded in 2-methacryloyloxyethyl phosphorylcholine (MPC) copolymers could be photo-oxidized, resulting in polymers able to form layers on a solid surface and conjugate with proteins. Moreover, nonspecific biofouling on the surface significantly reduced when the oxidized tyrosine units in the polymer layers were blocked. Upon UV irradiation through a photomask, the UV-exposed tyrosine units were selectively oxidized, forming the only specific regions in which protein conjugation could occur. Copyright © 2016 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Simulink-aided Design and Implementation of Sensorless BLDC Motor Digital Control System

NASA Astrophysics Data System (ADS)

Zhilenkov, A. A.; Tsvetkov, Y. N.; Chistov, V. B.; Nyrkov, A. P.; Sokolov, S. S.

2017-07-01

The paper describes the process of creating of brushless direct current motor’s digital control system. The target motor has no speed sensor, so back-EMF method is used for commutation control. Authors show how to model the control system in MatLab/Simulink and to test it onboard STM32F4 microcontroller.This technology allows to create the most flexible system, which will control possible with a personal computer by communication lines. It is possible to examine the signals in the circuit of the actuator without any external measuring instruments - testers, oscilloscopes, etc. - and output waveforms and measured values of signals directly on the host PC.

Loss of Ductility Caused by AlN Precipitation in Hadfield Steel

NASA Astrophysics Data System (ADS)

Radis, Rene; Schlacher, Christian; Kozeschnik, Ernst; Mayr, Peter; Enzinger, Norbert; Schröttner, Hartmuth; Sommitsch, Christof

2012-04-01

Two modified X120Mn12 Hadfield steels, differing in the amount of the alloying elements Al and N, are analyzed with respect to AlN precipitation and its effects on ductility. Charpy impact tests are performed, demonstrating the loss of ductility in the one grade containing a high density of AlN precipitates. The characterization of the precipitates is carried out by high-resolution scanning electron microscopy (HRSEM). Depending on chemical composition, primary and secondary AlN precipitates are detected on prior austenite grain boundaries and within the bulk volume. The experimental observations are confirmed by thermokinetic simulations, using the software package MatCalc (Vienna University of Technology, Vienna, Austria).

Temperature-dependant shifts in a wet tropical Hawaiian forest ecosystem: impact on belowground carbon stocks, dynamics, and processes

NASA Astrophysics Data System (ADS)

Crow, S. E.; Litton, C. M.; Giardina, C. P.

2009-12-01

Global patterns suggest a positive correlation between temperature and total belowground carbon (C) flux and partitioning in temperate and tropical regions, but these relationships have yet to be tested within a given ecosystem type. We established a transect of nine permanent forest plots along an elevation gradient (800-1600 m) in native-dominated Metrosideros polymorpha / Acacia koa rainforest developed in volcanic ash soils along the windward slope of Mauna Kea, Hawaii. Along the transect parent material, bedrock age, species composition, and plant available water are nearly constant and only mean annual temperature (MAT) varies substantially (13°C-18°C). We hypothesized that warmer temperatures at lower elevations would drive greater C flux and partitioning to belowground, which represents a direct input of C into belowground stocks. Roots are often sources of stabilized soil organic matter, thus we expected that increased belowground flux and partitioning of C at higher MATs would increase soil C stocks within recalcitrant C pools, even if bulk soil C stock decreases overall. In fact, our data suggest non-linear relationships between temperature and the distribution of C among soil pools based on sequential density fractionation at 1.6 and 2.4 g mL-1, and radiocarbon-based estimates of mean residence time. The proportion of C recovered within the mineral-associated heavy fraction (>2.4 g mL-1) was greatest at the highest MAT (nearly 30% of total soil C), initially declined at the mid-MAT plots (~10% of total soil C), but then increased again at the lowest MAT plots (~25%). Although the proportion of soil C within the heavy fraction was lowest at the mid-MAT plots, the mean residence time of heavy fraction C was greatest in these plots (570-663 yr for the mid-MAT plots versus 120-220 yr for the highest MAT plots and 64-308 for the lowest MAT plots), suggesting that the mineral-associated C in the mid-MAT plots was the most stabilized. In contrast, the proportion of C recovered within the rapidly cycling light fraction (<1.6 g mL-1) initially increased as MAT decreased, from <10% to a peak of nearly 50% of total soil C in the mid-MAT plots, but then decreased again in the plots with lowest MAT. High temperature both directly and indirectly stimulates weathering in these soils-which are thought to be within the phase of maximum nutrient availability, productivity, and potential SOM stabilization during ecosystem development-through increased belowground activity. However, complex feedbacks between temperature, resource allocation, weathering rate, and carbon storage may be driving non-linear relationships between temperature and soil processes.

Postnatal treatment with metyrapone attenuates the effects of diet-induced obesity in female rats exposed to early-life stress.

PubMed

Murphy, Margaret O; Herald, Joseph B; Wills, Caleb T; Unfried, Stanley G; Cohn, Dianne M; Loria, Analia S

2017-02-01

Experimental studies in rodents have shown that females are more susceptible to exhibiting fat expansion and metabolic disease compared with males in several models of fetal programming. This study tested the hypothesis that female rat pups exposed to maternal separation (MatSep), a model of early-life stress, display an exacerbated response to diet-induced obesity compared with male rats. Also, we tested whether the postnatal treatment with metyrapone (MTP), a corticosterone synthase inhibitor, would attenuate this phenotype. MatSep was performed in WKY offspring by separation from the dam (3 h/day, postnatal days 2-14). Upon weaning, male and female rats were placed on a normal (ND; 18% kcal fat) or high-fat diet (HFD; 60% kcal fat). Nondisturbed littermates served as controls. In male rats, no diet-induced differences in body weight (BW), glucose tolerance, and fat tissue weight and morphology were found between MatSep and control male rats. However, female MatSep rats displayed increased BW gain, fat pad weights, and glucose intolerance compared with control rats (P < 0.05). Also, HFD increased plasma corticosterone (196 ± 51 vs. 79 ± 18 pg/ml, P < 0.05) and leptin levels (1.8 ± 0.4 vs. 1.3 ± 0.1 ng/ml, P < 0.05) in female MatSep compared with control rats, whereas insulin and adiponectin levels were similar between groups. Female control and MatSep offspring were treated with MTP (50 µg/g ip) 30 min before the daily separation. MTP treatment significantly attenuated diet-induced obesity risk factors, including elevated adiposity, hyperleptinemia, and glucose intolerance. These findings show that exposure to stress hormones during early life could be a key event to enhance diet-induced obesity and metabolic disease in female rats. Thus, pharmacological and/or behavioral inflection of the stress levels is a potential therapeutic approach for prevention of early life stress-enhanced obesity and metabolic disease. Copyright © 2017 the American Physiological Society.

3D Multifunctional Ablative Thermal Protection System

NASA Technical Reports Server (NTRS)

Feldman, Jay; Venkatapathy, Ethiraj; Wilkinson, Curt; Mercer, Ken

2015-01-01

NASA is developing the Orion spacecraft to carry astronauts farther into the solar system than ever before, with human exploration of Mars as its ultimate goal. One of the technologies required to enable this advanced, Apollo-shaped capsule is a 3-dimensional quartz fiber composite for the vehicle's compression pad. During its mission, the compression pad serves first as a structural component and later as an ablative heat shield, partially consumed on Earth re-entry. This presentation will summarize the development of a new 3D quartz cyanate ester composite material, 3-Dimensional Multifunctional Ablative Thermal Protection System (3D-MAT), designed to meet the mission requirements for the Orion compression pad. Manufacturing development, aerothermal (arc-jet) testing, structural performance, and the overall status of material development for the 2018 EM-1 flight test will be discussed.

Risk assessment of medically assisted reproduction and advanced maternal ages in the development of Prader-Willi syndrome due to UPD(15)mat.

PubMed

Matsubara, K; Murakami, N; Fukami, M; Kagami, M; Nagai, T; Ogata, T

2016-05-01

Recent studies have suggested that disomic oocyte-mediated uniparental disomy 15 (UPD(15)mat) is increased in patients with Prader-Willi syndrome (PWS) born after medically assisted reproduction (MAR). However, it remains unknown whether the increase is primarily due to MAR procedure itself or advanced maternal childbearing ages as a predisposing factor for the disomic oocyte production. To examine this matter, we studied 122 naturally conceived PWS patients (PWS-NC group) and 13 MAR-conceived patients (PWS-MAR group). The relative frequency of disomic oocyte-mediated UPD(15)mat was significantly higher in PWS-MAR group than in PWS-NC group (7/13 vs 20/122, p = 0.0045), and the maternal childbearing ages were significantly higher in PWS-MAR group than in PWS-NC group [median (range), 38 (26-45) vs 30 (19-42), p = 0.0015]. However, the logistic regression analysis revealed no significant association between the occurrence of disomic oocyte-mediated UPD(15)mat and MAR, after adjusting for childbearing age (p = 0.25). Consistent with this, while the frequency of assisted reproductive technology (ART)-conceived livebirths was higher in the PWS patients than in the Japanese general population (6.4% vs 1.1%, p = 0.00018), the distribution of childbearing ages was significantly skewed to the increased ages in the PWS patients (p < 2.2 × 10(-16) ). These results argue against a positive association of MAR procedure itself with the development of UPD(15)mat. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Effects of stabilization exercises with a Swiss ball on neck-shoulder pain and mobility of adults with prolonged exposure to VDTs.

PubMed

Ahn, Jeoung-Ah; Kim, Joong-Hwi; Bendik, Anthony L; Shin, Ju-Yong

2015-04-01

[Purpose] This study compared the effects on neck-shoulder pain and mobility of strengthening exercises for the neck flexors and scapular retractors performed on a Swiss ball and a mat. [Subjects] Twenty student volunteers were the subjects. [Methods] The students were randomly assigned to two groups: Mat group (n=10), and Swiss ball group (n=10). At pre-test, post-test, and 1-week follow-up pain was assessed using the visual analogue scale (VAS), the pain pressure threshold (PPT) of the shoulder was measured with an algometer, and neck mobility was measured with a Zebris. [Results] The data analysis revealed that there was a significant decrease in pain and significant increase in neck flexion in both groups, and the Swiss ball group showed better results. [Conclusion] Strengthening the neck flexors and scapular retractors for stabilization of the neck using exercises on a Swiss ball was more effective at reducing the pain and stabilizing the neck than mat exercises.

Change of Direction Ability Performance in Cerebral Palsy Football Players According to Functional Profiles

PubMed Central

Reina, Raúl; Sarabia, Jose M.; Yanci, Javier; García-Vaquero, María P.; Campayo-Piernas, María

2016-01-01

The aims of the present study were to evaluate the validity and reliability of the two different change of direction ability (CODA) tests in elite football players with cerebral palsy (CP) and to analyse the differences in performance of this ability between current functional classes (FT) and controls. The sample consisted of 96 international cerebral palsy football players (FPCP) and 37 football players. Participants were divided into four different groups according to the International Federation of Cerebral Palsy Football (IFCPF) classes and a control group (CG): FT5 (n = 8); FT6 (n = 12); FT7 (n = 62); FT8 (n = 14); and CG (n = 37). The reproducibility of Modified Agility Test (MAT) and Illinois Agility Test (IAT) (ICC = 0.82–0.95, SEM = 2.5–5.8%) showed excellent to good values. In two CODA tests, CG performed faster scores compared with FPCP classes (p < 0.01, d = 1.76–3.26). In IAT, FT8 class comparisons regarding the other classes were: FT5 (p = 0.047, d = 1.05), FT6 (p = 0.055, d = 1.19), and FT7 (p = 0.396, d = 0.56). With regard to MAT, FT8 class was also compared with FT5 (p = 0.006, d = 1.30), FT6 (p = 0.061, d = 0.93), and FT7 (p = 0.033, d = 1.01). No significant differences have been found between FT5, FT6, and FT7 classes. According to these results, IAT and MAT could be useful and reliable and valid tests to analyse CODA in FPCP. Each test (IAT and MAT) could be applied considering the cut point that classifiers need to make a decision about the FT8 class and the other FT classes (FT5, FT6, and FT7). PMID:26779037

Lipopolysaccharide Specific Immunochromatography Based Lateral Flow Assay for Serogroup Specific Diagnosis of Leptospirosis in India

PubMed Central

Vanithamani, Shanmugam; Shanmughapriya, Santhanam; Narayanan, Ramasamy; Raja, Veerapandian; Kanagavel, Murugesan; Sivasankari, Karikalacholan; Natarajaseenivasan, Kalimuthusamy

2015-01-01

Background Leptospirosis is a re-emerging infectious disease that is under-recognized due to low-sensitivity and cumbersome serological tests. MAT is the gold standard test and it is the only serogroup specific test used till date. Rapid reliable alternative serogroup specific tests are needed for surveillance studies to identify locally circulating serogroups in the study area. Methods/Principal Findings In the present investigation the serological specificity of leptospiral lipopolysaccharides (LPS) was evaluated by enzyme linked immunosorbent assay (ELISA), dot blot assay and rapid immunochromatography based lateral flow assay (ICG-LFA). Sera samples from 120 MAT positive cases, 174 cases with febrile illness other than leptospirosis, and 121 seronegative healthy controls were evaluated for the diagnostic sensitivity and specificity of the developed assays. LPS was extracted from five locally predominant circulating serogroups including: Australis (27.5%), Autumnalis (11.7%), Ballum (25.8%), Grippotyphosa (12.5%), Pomona (10%) and were used as antigens in the diagnostics to detect IgM antibodies in patients’ sera. The sensitivity observed by IgM ELISA and dot blot assay using various leptospiral LPS was >90% for homologous sera. Except for Ballum LPS, no other LPS showed cross-reactivity to heterologous sera. An attempt was made to develop LPS based ICG-LFA for rapid and sensitive serogroup specific diagnostics of leptospirosis. The developed ICG-LFA showed sensitivity in the range between 93 and 100% for homologous sera. The Wilcoxon analysis showed LPS based ICG-LFA did not differ significantly from the gold standard MAT (P>0.05). Conclusion The application of single array of LPS for serogroup specific diagnosis is first of its kind. The developed assay could potentially be evaluated and employed for as MAT alternative. PMID:26340095

Maintaining two mating types: structure of the mating type locus and its role in heterokaryosis in Podospora anserina.

PubMed

Grognet, Pierre; Bidard, Frédérique; Kuchly, Claire; Tong, Laetitia Chan Ho; Coppin, Evelyne; Benkhali, Jinane Ait; Couloux, Arnaud; Wincker, Patrick; Debuchy, Robert; Silar, Philippe

2014-05-01

Pseudo-homothallism is a reproductive strategy elected by some fungi producing heterokaryotic sexual spores containing genetically different but sexually compatible nuclei. This lifestyle appears as a compromise between true homothallism (self-fertility with predominant inbreeding) and complete heterothallism (with exclusive outcrossing). However, pseudohomothallic species face the problem of maintaining heterokaryotic mycelia to fully benefit from this lifestyle, as homokaryons are self-sterile. Here, we report on the structure of chromosome 1 in mat+ and mat- isolates of strain S of the pseudohomothallic fungus Podospora anserina. Chromosome 1 contains either one of the mat+ and mat- mating types of P. anserina, which is mostly found in nature as a mat+/mat- heterokaryotic mycelium harboring sexually compatible nuclei. We identified a "mat" region ∼0.8 Mb long, devoid of meiotic recombination and containing the mating-type idiomorphs, which is a candidate to be involved in the maintenance of the heterokaryotic state, since the S mat+ and S mat- strains have different physiology that may enable hybrid-vigor-like phenomena in the heterokaryons. The mat region contains 229 coding sequences. A total of 687 polymorphisms were detected between the S mat+ and S mat- chromosomes. Importantly, the mat region is colinear between both chromosomes, which calls for an original mechanism of recombination inhibition. Microarray analyses revealed that 10% of the P. anserina genes have different transcriptional profiles in S mat+ and S mat-, in line with their different phenotypes. Finally, we show that the heterokaryotic state is faithfully maintained during mycelium growth of P. anserina, yet mat+/mat+ and mat-/mat- heterokaryons are as stable as mat+/mat- ones, evidencing a maintenance of heterokaryosis that does not rely on fitness-enhancing complementation between the S mat+ and S mat- strains.

Quantum Approaches to Logic Circuit Synthesis and Testing

DTIC Science & Technology

2006-06-01

with n qubits using Octave (Oct), MATLAB (MAT), Blitz++ (B++) and QuIDDPro (QP) with Oracle Design 1. 42 Table 4: Simulating Grover’s...algorithm with n qubits using Octave (Oct), MATLAB (MAT), Blitz++ (B++) and QuIDDPro (QP) with Oracle Design 2. 43 Table 5: Number of Grover iterations...to accurately characterize the effects of gate and systematic error in a quantum circuit that generates remotely entangled EPR pairs. An

Computer-Adaptive Testing: Implications for Students' Achievement, Motivation, Engagement, and Subjective Test Experience

ERIC Educational Resources Information Center

Martin, Andrew J.; Lazendic, Goran

2018-01-01

The present study investigated the implications of computer-adaptive testing (operationalized by way of multistage adaptive testing; MAT) and "conventional" fixed order computer testing for various test-relevant outcomes in numeracy, including achievement, test-relevant motivation and engagement, and subjective test experience. It did so…

Enjoying Sad Music: Paradox or Parallel Processes?

PubMed Central

Schubert, Emery

2016-01-01

Enjoyment of negative emotions in music is seen by many as a paradox. This article argues that the paradox exists because it is difficult to view the process that generates enjoyment as being part of the same system that also generates the subjective negative feeling. Compensation theories explain the paradox as the compensation of a negative emotion by the concomitant presence of one or more positive emotions. But compensation brings us no closer to explaining the paradox because it does not explain how experiencing sadness itself is enjoyed. The solution proposed is that an emotion is determined by three critical processes—labeled motivational action tendency (MAT), subjective feeling (SF) and Appraisal. For many emotions the MAT and SF processes are coupled in valence. For example, happiness has positive MAT and positive SF, annoyance has negative MAT and negative SF. However, it is argued that in an aesthetic context, such as listening to music, emotion processes can become decoupled. The decoupling is controlled by the Appraisal process, which can assess if the context of the sadness is real-life (where coupling occurs) or aesthetic (where decoupling can occur). In an aesthetic context sadness retains its negative SF but the aversive, negative MAT is inhibited, leaving sadness to still be experienced as a negative valanced emotion, while contributing to the overall positive MAT. Individual differences, mood and previous experiences mediate the degree to which the aversive aspects of MAT are inhibited according to this Parallel Processing Hypothesis (PPH). The reason for hesitancy in considering or testing PPH, as well as the preponderance of research on sadness at the exclusion of other negative emotions, are discussed. PMID:27445752

Comparison of three diagnostic methods for the detection of Toxoplasma gondii in free range chickens.

PubMed

Hamidinejat, H; Nabavi, L; Mayahi, M; Ghourbanpoor, M; Pourmehdi Borojeni, M; Norollahi Fard, S; Shokrollahi, M

2014-09-01

Detection of Toxoplasma gondii in free range chickens is an indicator of the prevalence and distribution pattern of T. gondii in the environment. For this purpose, serologic assays especially modified agglutination test (MAT) is the main approach in the literature. The main goal of this study was to compare the polymerase chain reaction (PCR) based on amplification of first internal transcribed spacer (ITS-1) of ribosomal DNA gene, ELISA, and MAT to demonstrate T. gondii infection in free range chicken. A total of 106 adult free - range chickens were killed. Blood, whole heart and brain samples were taken. Sera were examined for the presence of T. gondii antibodies by ELISA and MAT as well. Selected tissues were used for PCR and bioassay in mice. The results revealed that 48.11%, 51.89%, 46.23% and 27.36% of chickens were positive in ELISA, MAT, PCR and bioassay in mice respectively. Good correlation between the results of PCR, ELISA and MAT were detected, but not with bioassay in mice. Compared with PCR, the sensitivity and specificity of ELISA were 92.16% and 96.36% respectively and also for MAT, the sensitivity was 81.81% and the specificity was 92.15%. The specific diagnosis of T. gondii infection in chickens is central to a better understanding of the epidemiology and dynamics of transmission among the various host population and is particularly important for planning effective optimal prevention and control programs. Our data in the present study demonstrated that PCR, ELISA and the MAT are helpful and precise methods to detect T. gondii in naturally infected free-range chickens.

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 practIcal scripts (pro grams) that extend the basic features of MatLab TOPICS mclude (1) Ma trix and vector analysis and manipulations (2) Mathematical functions (3) Symbolic calculations & functions (4) Import/export data files (5) Program lOgic and flow control (6) Writing function and passing parameters (7) Test application programs

Dynamic footprint measurement collection technique and intrarater reliability: ink mat, paper pedography, and electronic pedography.

PubMed

Fascione, Jeanna M; Crews, Ryan T; Wrobel, James S

2012-01-01

Identifying the variability of footprint measurement collection techniques and the reliability of footprint measurements would assist with appropriate clinical foot posture appraisal. We sought to identify relationships between these measures in a healthy population. On 30 healthy participants, midgait dynamic footprint measurements were collected using an ink mat, paper pedography, and electronic pedography. The footprints were then digitized, and the following footprint indices were calculated with photo digital planimetry software: footprint index, arch index, truncated arch index, Chippaux-Smirak Index, and Staheli Index. Differences between techniques were identified with repeated-measures analysis of variance with post hoc test of Scheffe. In addition, to assess practical similarities between the different methods, intraclass correlation coefficients (ICCs) were calculated. To assess intrarater reliability, footprint indices were calculated twice on 10 randomly selected ink mat footprint measurements, and the ICC was calculated. Dynamic footprint measurements collected with an ink mat significantly differed from those collected with paper pedography (ICC, 0.85-0.96) and electronic pedography (ICC, 0.29-0.79), regardless of the practical similarities noted with ICC values (P = .00). Intrarater reliability for dynamic ink mat footprint measurements was high for the footprint index, arch index, truncated arch index, Chippaux-Smirak Index, and Staheli Index (ICC, 0.74-0.99). Footprint measurements collected with various techniques demonstrate differences. Interchangeable use of exact values without adjustment is not advised. Intrarater reliability of a single method (ink mat) was found to be high.

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 code in MAT is written for Microsoft QuickBasic 4.5 and Microsoft Macro Assembler 5.1. This package requires a joystick and EGA or VGA color graphics. An 80286, 386, or 486 processor machine is highly recommended. The standard distribution medium for MAT is a 5.25 inch 360K MS-DOS format diskette. The files are compressed using the PKZIP file compression utility. PKUNZIP is included on the distribution diskette. MAT was developed in 1992. IBM PC is a registered trademark of International Business Machines. MS-DOS, Microsoft QuickBasic, and Microsoft Macro Assembler are registered trademarks of Microsoft Corporation. PKZIP and PKUNZIP are registered trademarks of PKWare, Inc.

Gaussian process regression for geometry optimization

NASA Astrophysics Data System (ADS)

Denzel, Alexander; Kästner, Johannes

2018-03-01

We implemented a geometry optimizer based on Gaussian process regression (GPR) to find minimum structures on potential energy surfaces. We tested both a two times differentiable form of the Matérn kernel and the squared exponential kernel. The Matérn kernel performs much better. We give a detailed description of the optimization procedures. These include overshooting the step resulting from GPR in order to obtain a higher degree of interpolation vs. extrapolation. In a benchmark against the Limited-memory Broyden-Fletcher-Goldfarb-Shanno optimizer of the DL-FIND library on 26 test systems, we found the new optimizer to generally reduce the number of required optimization steps.

Evaluation of single and multilocus DNA barcodes towards species delineation in complex tree genus Terminalia

PubMed Central

Mishra, Priyanka; Kumar, Amit; Nagireddy, Akshitha; Shukla, Ashutosh K.

2017-01-01

DNA barcoding is used as a universal tool for delimiting species boundaries in taxonomically challenging groups, with different plastid and nuclear regions (rbcL, matK, ITS and psbA-trnH) being recommended as primary DNA barcodes for plants. We evaluated the feasibility of using these regions in the species-rich genus Terminalia, which exhibits various overlapping morphotypes with pantropical distribution, owing to its complex taxonomy. Terminalia bellerica and T. chebula are ingredients of the famous Ayurvedic Rasayana formulation Triphala, used for detoxification and rejuvenation. High demand for extracted phytochemicals as well as the high trade value of several species renders mandatory the need for the correct identification of traded plant material. Three different analytical methods with single and multilocus barcoding regions were tested to develop a DNA barcode reference library from 222 individuals representing 41 Terminalia species. All the single barcodes tested had a lower discriminatory power than the multilocus regions, and the combination of matK+ITS had the highest resolution rate (94.44%). The average intra-specific variations (0.0188±0.0019) were less than the distance to the nearest neighbour (0.106±0.009) with matK and ITS. Distance-based Neighbour Joining analysis outperformed the character-based Maximum Parsimony method in the identification of traded species such as T. arjuna, T. chebula and T. tomentosa, which are prone to adulteration. rbcL was shown to be a highly conservative region with only 3.45% variability between all of the sequences. The recommended barcode combination, rbcL+matK, failed to perform in the genus Terminalia. Considering the complexity of resolution observed with single regions, the present study proposes the combination of matK+ITS as the most successful barcode in Terminalia. PMID:28829803

Should Ballet Dancers Vary Postures and Underfoot Surfaces When Practicing Postural Balance?

PubMed

Steinberg, Nili; Waddington, Gordon; Adams, Roger; Karin, Janet; Tirosh, Oren

2018-01-01

Postural balance (PB) is an important component skill for professional dancers. However, the effects of different types of postures and different underfoot surfaces on PB have not adequately been addressed. The main aim of this study was to investigate the effect of different conditions of footwear, surfaces, and standing positions on static and dynamic PB ability of young ballet dancers. A total of 36 male and female young professional ballet dancers (aged 14-19 years) completed static and dynamic balance testing, measured by head and lumbar accelerometers, while standing on one leg in the turnout position, under six different conditions: (1) "relaxed" posture; (2) "ballet" posture; (3) barefoot; (4) ballet shoes with textured insoles; (5) barefoot on a textured mat; and (6) barefoot on a spiky mat. A condition effect was found for static and dynamic PB. Static PB was reduced when dancers stood in the ballet posture compared with standing in the relaxed posture and when standing on a textured mat and on a spiky mat (p < .05), and static PB in the relaxed posture was significantly better than PB in all the other five conditions tested. Dynamic PB was significantly better while standing in ballet shoes with textured insoles and when standing on a spiky mat compared with all other conditions (p < .05). The practical implications derived from this study are that both male and female dancers should try to be relaxed in their postural muscles when practicing a ballet aligned position, including dance practice on different types of floors and on different types of textured/spiky materials may result in skill transfer to practice on normal floor surfaces, and both static and dynamic PB exercises should be assessed and generalized into practical dance routines.

A knowledge-based system design/information tool for aircraft flight control systems

NASA Technical Reports Server (NTRS)

Mackall, Dale A.; Allen, James G.

1991-01-01

Research aircraft have become increasingly dependent on advanced electronic control systems to accomplish program goals. These aircraft are integrating multiple disciplines to improve performance and satisfy research objective. This integration is being accomplished through electronic control systems. Systems design methods and information management have become essential to program success. The primary objective of the system design/information tool for aircraft flight control is to help transfer flight control system design knowledge to the flight test community. By providing all of the design information and covering multiple disciplines in a structured, graphical manner, flight control systems can more easily be understood by the test engineers. This will provide the engineers with the information needed to thoroughly ground test the system and thereby reduce the likelihood of serious design errors surfacing in flight. The secondary object is to apply structured design techniques to all of the design domains. By using the techniques in the top level system design down through the detailed hardware and software designs, it is hoped that fewer design anomalies will result. The flight test experiences are reviewed of three highly complex, integrated aircraft programs: the X-29 forward swept wing; the advanced fighter technology integration (AFTI) F-16; and the highly maneuverable aircraft technology (HiMAT) program. Significant operating technologies, and the design errors which cause them, is examined to help identify what functions a system design/informatin tool should provide to assist designers in avoiding errors.

Evaluation of DNA barcode candidates for the discrimination of Artemisia L.

PubMed

Liu, Geyu; Ning, Huixia; Ayidaerhan, Nurbolati; Aisa, Haji Akber

2017-11-01

Because of the very similar morphologies and wide diversity of Artemisia L. varieties, they are difficult to identify, and there have been many arguments about the systematic classification Artemisia L., especially concerning the division of species. DNA barcode technology is used to rapidly identify species based on standard short DNA sequences. To evaluate seven candidate DNA barcodes (ITS, ITS2, psbA-trnH, rbcL, matK, rpoB, and rpoC1) regarding their ability to identify closely related species of the Artemisia genus in Xinjiang. The corresponding PCR amplification efficiency, detectable genetic divergence, identification efficiency and phylogenetic tree were assessed. We found that the internal transcribed spacer (ITS) region exhibited the highest interspecific divergence, which was significantly higher than the observed intraspecific variation and showed the highest identification efficiency, followed by ITS2, psbA-trnH and, finally, rpoB. matK, rbcL, and rpoC1 performed poorly in this evaluation. ITS, ITS2, and psbA-trnH were able to perfectly identify the tested species Artemisia annua, A. absinthium, A. rupestris, A. tonurnefortiana, A. austriaca, A. dracunculus, A. vulgaris, and A. macrocephala. Therefore, we propose the ITS, ITS2, and psbA-trnH regions as promising DNA barcodes for the closely related species of Artemisia L. in Xinjiang.

Air data position-error calibration using state reconstruction techniques

NASA Technical Reports Server (NTRS)

Whitmore, S. A.; Larson, T. J.; Ehernberger, L. J.

1984-01-01

During the highly maneuverable aircraft technology (HiMAT) flight test program recently completed at NASA Ames Research Center's Dryden Flight Research Facility, numerous problems were experienced in airspeed calibration. This necessitated the use of state reconstruction techniques to arrive at a position-error calibration. For the HiMAT aircraft, most of the calibration effort was expended on flights in which the air data pressure transducers were not performing accurately. Following discovery of this problem, the air data transducers of both aircraft were wrapped in heater blankets to correct the problem. Additional calibration flights were performed, and from the resulting data a satisfactory position-error calibration was obtained. This calibration and data obtained before installation of the heater blankets were used to develop an alternate calibration method. The alternate approach took advantage of high-quality inertial data that was readily available. A linearized Kalman filter (LKF) was used to reconstruct the aircraft's wind-relative trajectory; the trajectory was then used to separate transducer measurement errors from the aircraft position error. This calibration method is accurate and inexpensive. The LKF technique has an inherent advantage of requiring that no flight maneuvers be specially designed for airspeed calibrations. It is of particular use when the measurements of the wind-relative quantities are suspected to have transducer-related errors.

Electrospinning of Nanodiamond-Modified Polysaccharide Nanofibers with Physico-Mechanical Properties Close to Natural Skins

PubMed Central

Mahdavi, Mina; Mahmoudi, Nafiseh; Rezaie Anaran, Farzad; Simchi, Abdolreza

2016-01-01

Electrospinning of biopolymers has gained significant interest for the fabrication of fibrous mats for potential applications in tissue engineering, particularly for wound dressing and skin regeneration. In this study, for the first time, we report successful electrospinning of chitosan-based biopolymers containing bacterial cellulous (33 wt %) and medical grade nanodiamonds (MND) (3 nm; up to 3 wt %). Morphological studies by scanning electron microscopy showed that long and uniform fibers with controllable diameters from 80 to 170 nm were prepared. Introducing diamond nanoparticles facilitated the electrospinning process with a decrease in the size of fibers. Fourier transform infrared spectroscopy determined hydrogen bonding between the polymeric matrix and functional groups of MND. It was also found that beyond 1 wt % MND, percolation networks of nanoparticles were formed which affected the properties of the nanofibrous mats. Uniaxial tensile testing of the woven mats determined significant enhancement of the strength (from 13 MPa to 25 MP) by dispersion of 1 wt % MND. The hydrophilicity of the mats was also remarkably improved, which was favorable for cell attachment. The water vapor permeability was tailorable in the range of 342 to 423 µg·Pa−1·s−1·m−1. The nanodiamond-modified mats are potentially suitable for wound healing applications. PMID:27399726

Involvement of microbial mats in early fossilization by decay delay and formation of impressions and replicas of vertebrates and invertebrates

NASA Astrophysics Data System (ADS)

Iniesto, Miguel; Buscalioni, Ángela D.; Carmen Guerrero, M.; Benzerara, Karim; Moreira, David; López-Archilla, Ana I.

2016-05-01

Microbial mats have been hypothesized to improve the persistence and the preservation of organic remains during fossilization processes. We test this hypothesis with long-term experiments (up to 5.5 years) using invertebrate and vertebrate corpses. Once placed on mats, the microbial community coats the corpses and forms a three-dimensional sarcophagus composed of microbial cells and exopolymeric substances (EPS). This coverage provides a template for i) moulding superficial features, resulting in negative impressions, and ii) generating replicas. The impressions of fly setulae, fish scales and frog skin verrucae are shaped mainly by small cells in an EPS matrix. Microbes also replicate delicate structures such as the three successive layers that compose a fish eye. The sarcophagus protects the body integrity, allowing the persistence of inner organs such as the ovaries and digestive apparatus in flies, the swim bladder and muscles in fish, and the bone marrow in frog legs. This study brings strong experimental evidence to the idea that mats favour metazoan fossilization by moulding, replicating and delaying decay. Rapid burial has classically been invoked as a mechanism to explain exceptional preservation. However, mats may play a similar role during early fossilization as they can preserve complex features for a long time.

Clinical manifestation, serology marker & microscopic agglutination test (MAT) to mortality in human leptospirosis

NASA Astrophysics Data System (ADS)

Perdhana, S. A. P.; Susilo, R. S. B.; Arifin; Redhono, D.; Sumandjar, T.

2018-03-01

Leptospirosis is a potentially fatal zoonosis that is endemic in many tropical regions and causes large epidemics after heavy rainfall and flooding. Severe disease is estimated 5–15% of all human infections. Its mortality rate is 5-40%. MAT, isolation of the organism, or leptospiral DNA in PCR are used to confirm Leptospirosis. This cross-sectional analytic study recruited 26 hospitalized leptospirosis patients admitted to Dr. Moewardi Hospital Surakarta. The diagnosis was based on clinical, laboratory and epidemiological findings. The onset of the disease was the date when the first symptom started, and the end of the analysis was the date when the patient died or discharged. Modified Faine’s score ≥ 25 tend to die (45.5%) while modified Faine’s score 20 – 24 tend to heal (60%) (OR 1.250; CI 0.259-6.029; p=1.0). Seropositive IgM predicts mortality 7.8 times higher than seronegative IgM (OR 7.800; CI 1.162-52.353; p=0.038). MAT positive predict mortality 10.667 times higher than MAT negative (OR 10.667; CI 1.705-66.720; p=0.015). Clinical manifestation, MAT, and serologic marker are all correlated with mortality in Leptospirosis. However, statistically, clinical manifestation has an insignificant correlation.

Involvement of microbial mats in early fossilization by decay delay and formation of impressions and replicas of vertebrates and invertebrates

PubMed Central

Iniesto, Miguel; Buscalioni, Ángela D.; Carmen Guerrero, M.; Benzerara, Karim; Moreira, David; López-Archilla, Ana I.

2016-01-01

Microbial mats have been hypothesized to improve the persistence and the preservation of organic remains during fossilization processes. We test this hypothesis with long-term experiments (up to 5.5 years) using invertebrate and vertebrate corpses. Once placed on mats, the microbial community coats the corpses and forms a three-dimensional sarcophagus composed of microbial cells and exopolymeric substances (EPS). This coverage provides a template for i) moulding superficial features, resulting in negative impressions, and ii) generating replicas. The impressions of fly setulae, fish scales and frog skin verrucae are shaped mainly by small cells in an EPS matrix. Microbes also replicate delicate structures such as the three successive layers that compose a fish eye. The sarcophagus protects the body integrity, allowing the persistence of inner organs such as the ovaries and digestive apparatus in flies, the swim bladder and muscles in fish, and the bone marrow in frog legs. This study brings strong experimental evidence to the idea that mats favour metazoan fossilization by moulding, replicating and delaying decay. Rapid burial has classically been invoked as a mechanism to explain exceptional preservation. However, mats may play a similar role during early fossilization as they can preserve complex features for a long time. PMID:27162204

Comparison of impact force attenuation by various combinations of hip protector and flooring material using a simplified fall-impact simulation device.

PubMed

Li, Ning; Tsushima, Eiki; Tsushima, Hitoshi

2013-04-05

Use of hip protectors and compliant flooring has been recommended for preventing hip fracture due to falls. We aimed to identify the factors attenuating forces in falls by comparing and analyzing the impact forces occurring with various combinations of hip protectors and flooring materials. We designed a simplified pendulum device to simulate the impact force at the hip during falling. The impact force was measured on pressure-sensitive recording film under combined conditions of two kinds of hip protector (hard or soft shell) and three kinds of floor material (concrete, wooden, or tatami matting). We then calculated the percentage force attenuation under each test condition compared with the use of a concrete floor and no hip protector. All the tests using tatami matting reduced the impact to below the average fracture threshold of elderly people (3472N). A combination of tatami and soft hip protector provided the best attenuation (72.5%). Multiple regression analyses showed that use of tatami matting and a soft hip protector had the biggest force-attenuation effect. The soft hip protector gave better percentage force attenuation than did the hard one. Use of tatami matting as a flooring material could be an effective strategy for helping prevent hip fractures. Copyright © 2013 Elsevier Ltd. All rights reserved.

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 variation in the electrochemical conditions under which mats were generated significantly impacted the relative abundances of mat members and mat metabolism.« less

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 variation in the electrochemical conditions under which mats were generated significantly impacted the relative abundances of mat members and mat metabolism.« less

Clean Energy Business Plan Competition

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

Maxted, Sara Jane; Lojewski, Brandon; Scherson, Yaniv

Top Students Pitch Clean Energy Business Plans The six regional finalists of the National Clean Energy Business Plan Competition pitched their business plans to a panel of judges June 13 in Washington, D.C. The expert judges announced NuMat Technologies from Northwestern University as the grand prize winner.

Role of research aircraft in technology development

NASA Technical Reports Server (NTRS)

Szalai, K. J.

1984-01-01

The United States's aeronautical research program has been rich in the use of research aircraft to explore new flight regimes, develop individual aeronautical concepts, and investigate new vehicle classes and configurations. This paper reviews the NASA supercritical wing, digital fly-by-wire, HiMAT, and AD-1 oblique-wing flight research programs, and draws from these examples general conclusions regarding the role and impact of research aircraft in technology development. The impact of a flight program on spinoff technology is also addressed. The secondary, serendipitous results are often highly significant. Finally, future research aircraft programs are examined for technology trends and expected results.

Test and Analysis of Foam Impacting a 6x6 Inch RCC Flat Panel

NASA Technical Reports Server (NTRS)

Lessard, Wendy B.

2006-01-01

This report presents the testing and analyses of a foam projectile impacting onto thirteen 6x6 inch flat panels at a 90 degrees incidence angle. The panels tested in this investigation were fabricated of Reinforced-Carbon-Carbon material and were used to aid in the validation of an existing material model, MAT58. The computational analyses were performed using LS-DYNA, which is a physics-based, nonlinear, transient, finite element code used for analyzing material responses subjected to high impact forces and other dynamic conditions. The test results were used to validate LS-DYNA predictions and to determine the threshold of damage generated by the MAT58 cumulative damage material model. The threshold of damage parameter represents any external or internal visible RCC damage detectable by nondestructive evaluation techniques.

Zero Robotics at Kennedy Space Center Visitor Complex

NASA Image and Video Library

2017-08-11

A programmable off-the-shelf Sphero robot is shown on a Mars mat at the Center for Space Education at NASA's Kennedy Space Center in Florida. The Spheros were available for students to practice their programming skills by navigating the robots around a challenge course on the mat. Students used the mat and Sphero robots during "loss of signal" times when the connection to the International Space Station was temporarily unavailable. Teams from across the state of Florida were gathered at Kennedy for the finals of the Zero Robotics Middle School Summer Program national championship. The five-week program allows rising sixth- through ninth-graders to write programs for small satellites called SPHERES (Synchronized, Position, Hold, Engage, Reorient, Experimental Satellites). Finalists saw their code tested aboard the orbiting laboratory.

Dairy cow preferences for soft or hard flooring when standing or walking.

PubMed

Telezhenko, E; Lidfors, L; Bergsten, C

2007-08-01

Concrete is the most commonly used alley flooring in confined dairy herds because of its qualities of construction and ease of cleaning. Nevertheless, the hardness, abrasiveness, and slipperiness of concrete floors have adverse effects on animal well-being and health, and yielding rubber flooring is becoming popular as a way of improving the flooring conditions on walkways. The aim of this study was to investigate preferences of dairy cows for rubber compared with concrete flooring under the conditions of a commercial dairy farm. The study was conducted in an organic dairy herd with free-stall housing. Floor preference was tested on groups of standing cows in a 120-m2 holding pen before milking, and 1 yr later on a 12- x 3-m walkway. The holding pen and the walkway were divided lengthwise into 2 identical sections. Two types of solid rubber mats (soft and extra soft) were tested against solid concrete in the holding pen. Slatted and solid rubber mats were tested against slatted concrete in the walkway. Each floor type was tested over 4 d on the left side and 4 d on the right side of the holding pen and the walkway, respectively. Concrete flooring on both sides of the sections was tested as a control before the testing of different section materials. All observations of the distribution of cows in the sections were made from video recordings captured in association with the afternoon milking. The number of cows on each section was recorded approximately every 7 min in the holding pen, and continuously on the walkway. A significantly higher proportion of cows stood on the side with the soft and extra soft rubber mats (65.1 +/- 2.7 and 69.3 +/- 2.6%, respectively, mean +/- SEM) compared with the control distribution when only the solid concrete was available (50.9 +/- 3.9%). A significantly higher proportion of nonlame cows walked exclusively on the side with the slatted (64.5 +/- 5.4%, d 4) or solid rubber mats (68.2 +/- 5.1%, d 4) compared with controls (28.9 +/- 4.3%). Lame cows within a group of walking cows did not show a higher preference for soft flooring as distinct as nonlame cows (52.7 +/- 6.9 and 59.4 +/- 6.2% for the solid and slatted rubber mats, respectively, at d 4 vs. 40.3 +/- 6.2% for control), presumably because of competition with other, higher ranked cows. It was concluded that the majority of cows preferred to walk and stand on soft rubber rather than on concrete flooring.

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 oxidation, including (1) removing Fe oxyhydroxide waste without entombing cells or clogging flow paths through the mat and (2) colonizing niches where Fe(II) and O2 overlap. This work improves our understanding of Fe mat developmental history and how mat morphology links to metabolism. We can use these results to interpret biogenicity, metabolism, and paleoenvironmental conditions of Fe microfossil mats, which would give us insight into Earth's Fe and O2 history. PMID:27313567

Large Crater Repair at Silver Flag Exercise Site, Tyndall Air Force Base, Florida

DTIC Science & Technology

2015-08-01

fiberglass mat ( FFM ) survived medium-speed braking events and was deemed suitable for use on taxiways and aprons. 2. The current USAF FFM system failed...braking events due to failure of the connector bushings. After replacement with more robust connector bushings from the FFM system, the FRP system...withstood the high-speed taxi events that caused the FFM to fail. ERDC/GSL TR-15-27 2 4. AM2 aluminum matting was successfully tested as a suitable

Direct Piezoelectricity of Soft Composite Electrospun Fibers

NASA Astrophysics Data System (ADS)

Varga, Michael; Morvan, Jason; Diorio, Nick; Buyuktanir, Ebru; Harden, John; West, John; Jakli, Antal

2013-03-01

Recently soft fiber mats electrospun from solutions of Barium Titanate (BT) ferroelectric ceramics particles and poly lactic acid (PLA) were found to have large (d33 1nm/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 various BT concentrations. A testing apparatus was designed and constructed solely for these measurements involving AC stresses provided by a speaker in 10Hz-10kHz frequency range. The piezoelectric constant d33 ~1nC/N was found to be in agreement with the prior converse piezoelectric measurements. The largest signals were obtained with 6% BT/PLA composites, probably because the BT particles at higher concentrations could not be dispersed homogeneously. Importantly the direct piezoelectric signal is large enough to power a small LCD by simply pressing a 0.2mm thick 2 cm2 area mat by a finger. We expect to use these mats in active Braille cells and in liquid crystal writing tablets.

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.

Implications of a 3.472-3.333 Gyr-old subaerial microbial mat from the Barberton greenstone belt, South Africa for the UV environmental conditions on the early Earth.

PubMed

Westall, Frances; de Ronde, Cornel E J; Southam, Gordon; Grassineau, Nathalie; Colas, Maggy; Cockell, Charles; Lammer, Helmut

2006-10-29

Modelling suggests that the UV radiation environment of the early Earth, with DNA weighted irradiances of about three orders of magnitude greater than those at present, was hostile to life forms at the surface, unless they lived in specific protected habitats. However, we present empirical evidence that challenges this commonly held view. We describe a well-developed microbial mat that formed on the surface of volcanic littoral sediments in an evaporitic environment in a 3.5-3.3Ga-old formation from the Barberton greenstone belt. Using a multiscale, multidisciplinary approach designed to strongly test the biogenicity of potential microbial structures, we show that the mat was constructed under flowing water by 0.25 microm filaments that produced copious quantities of extracellular polymeric substances, representing probably anoxygenic photosynthesizers. Associated with the mat is a small colony of rods-vibroids that probably represent sulphur-reducing bacteria. An embedded suite of evaporite minerals and desiccation cracks in the surface of the mat demonstrates that it was periodically exposed to the air in an evaporitic environment. We conclude that DNA-damaging UV radiation fluxes at the surface of the Earth at this period must either have been low (absorbed by CO2, H2O, a thin organic haze from photo-dissociated CH4, or SO2 from volcanic outgassing; scattered by volcanic, and periodically, meteorite dust, as well as by the upper layers of the microbial mat) and/or that the micro-organisms exhibited efficient gene repair/survival strategies.

[The effects of 16-weeks pilates mat program on anthropometric variables and body composition in active adult women after a short detraining period].

PubMed

Vaquero-Cristóbal, Raquel; Alacid, Fernando; Esparza-Ros, Francisco; Muyor, José M; López-Miñarro, Pedro Ángel

2015-04-01

previous studies have analysed the effect of mat Pilates practice on anthropometric variables and body composition in sedentaries. To date no researchs have investigated the benefits of Pilates on these variables after a short detraining period. to determine the effect of a 16-week mat Pilates program on anthropometric variables, body composition and somatotype of women with previous practice experience after three weeks of detraining period. twenty-one women underwent a complete anthropometric assessment according with ISAK guidelines before and after a 16 week mat Pilates program (two days, one hour). All women had one to three years of mat Pilates experience and came to three weeks of detraining period (Christmas holiday). women showed significant decreases for body mass, BMI, upper limb (biceps and triceps) and trunk (subscapular, iliac crest, supraspinale and abdominal) individual skinfolds, 6 and 8 skinfold sums, endomorphy and fat mass; and a significant increases for muscle mass. The mean somatotype was classified as mesomorphic endomorph in the pre- (4.91, 4.01, 1.47) and post-test (4.68, 4.16, 1.69). Eight women changed their somatotype clasification after the intervention program. the practice of mat Pilates for 16 weeks caused changes associated with health state improvements on anthropometric variables, especially on skinfolds which significantly decreased, body composition (fat and muscle masses decreased and increased, respectively) and somatotype (there was a significantly decreased on the endomorph component in experienced women after three week of detraning. Copyright AULA MEDICA EDICIONES 2014. Published by AULA MEDICA. All rights reserved.

Formation of Microbial Streamers by Flow-Induced Shear and Their Hydrodynamic Effects

NASA Astrophysics Data System (ADS)

Gong, J.; Olsen, K. A.; Nguyen, T.; Tice, M. M.; 2012; 2013, G. C.

2014-12-01

Microbial streamers are productive elements of surface-attached microbial communities that paradoxically seem to roughen mats under rapid, high shear flows, potentially exposing the mat to greater risk of erosion. They are common features found in modern hot-spring outflow channels, yet their formation mechanisms and effects on mat erosion are poorly understood. We test a hypothesis that streamers are produced by shear-induced viscoelastic deformation, and that streamers grow to heal detached turbulent boundary layers. Laboratory flume experiments were conducted using Particle Image/Tracking Velocimetry (PIV/PTV) to gain quantitative insights into the behavior of flows around small projections constructed from 3D-printed plastics or hydrated EPS gels, as well as artificial streamers. The combined use of fabricated hard and viscoelastic shapes, tracer particles, sheet lasers and high speed cameras allowed visualization of flows and quantitative measurements. Results show that primary and secondary flows (backflow behind projections) combine to produce deformations that drive the elongation of the top and ultimately initiate streamer formation. With insufficient secondary flows, streamers are not able to rise up from the basal mat. This implies that a combination of sufficient topographic relief and flow strength is required for streamers to form. In addition, flow measurements indicate that the presence of artificial streamers made the surface hydraulically smoother, and in effect reducing bed shear at the base. These results suggest a novel set of feedbacks that could reduce net mat erosion in energetic flows, and could help guide the evaluation of biosignatures in sedimentary rocks deposited in the presence of microbial mats.

Reducing Behavioral Health Inpatient Readmissions for People With Substance Use Disorders: Do Follow-Up Services Matter?

PubMed

Reif, Sharon; Acevedo, Andrea; Garnick, Deborah W; Fullerton, Catherine A

2017-08-01

Individuals with substance use disorders are at high risk of hospital readmission. This study examined whether follow-up services received within 14 days of discharge from an inpatient hospital stay or residential detoxification reduced 90-day readmissions among Medicaid enrollees whose index admission included a substance use disorder diagnosis. Claims data were analyzed for Medicaid enrollees ages 18-64 with a substance use disorder diagnosis coded in any position for an inpatient hospital stay or residential detoxification in 2008 (N=30,439). Follow-up behavioral health services included residential, intensive outpatient, outpatient, and medication-assisted treatment (MAT). Analyses included data from ten states or fewer, based on a minimum number of index admissions and the availability of follow-up services or MAT. Survival analyses with time-varying independent variables were used to test the association of receipt of follow-up services and MAT with behavioral health readmissions. Two-thirds (67.7%) of these enrollees received no follow-up services within 14 days. Twenty-nine percent were admitted with a primary behavioral health diagnosis within 90 days of discharge. Survival analyses showed that MAT and residential treatment were associated with reduced risk of 90-day behavioral health admission. Receipt of outpatient treatment was associated with increased readmission risk, and, in only one model, receipt of intensive outpatient services was also associated with increased risk. Provision of MAT or residential treatment for substance use disorders after an inpatient or detoxification stay may help prevent readmissions. Medicaid programs should be encouraged to reduce barriers to MAT and residential treatment in order to prevent behavioral health admissions.

Pleiotropic effects of methionine adenosyltransferases deregulation as determinants of liver cancer progression and prognosis.

PubMed

Frau, Maddalena; Feo, Francesco; Pascale, Rosa M

2013-10-01

Downregulation of liver-specific MAT1A gene, encoding S-adenosylmethionine (SAM) synthesizing isozymes MATI/III, and upregulation of widely expressed MAT2A, encoding MATII isozyme, known as MAT1A:MAT2A switch, occurs in hepatocellular carcinoma (HCC). Being inhibited by its reaction product, MATII isoform upregulation cannot compensate for MATI/III decrease. Therefore, MAT1A:MAT2A switch contributes to decrease in SAM level in rodent and human hepatocarcinogenesis. SAM administration to carcinogen-treated rats prevents hepatocarcinogenesis, whereas MAT1A-KO mice, characterized by chronic SAM deficiency, exhibit macrovesicular steatosis, mononuclear cell infiltration in periportal areas, and HCC development. This review focuses upon the pleiotropic changes, induced by MAT1A/MAT2A switch, associated with HCC development. Epigenetic control of MATs expression occurs at transcriptional and post-transcriptional levels. In HCC cells, MAT1A/MAT2A switch is associated with global DNA hypomethylation, decrease in DNA repair, genomic instability, and signaling deregulation including c-MYC overexpression, rise in polyamine synthesis, upregulation of RAS/ERK, IKK/NF-kB, PI3K/AKT, and LKB1/AMPK axis. Furthermore, decrease in MAT1A expression and SAM levels results in increased HCC cell proliferation, cell survival, and microvascularization. All of these changes are reversed by SAM treatment in vivo or forced MAT1A overexpression or MAT2A inhibition in cultured HCC cells. In human HCC, MAT1A:MAT2A and MATI/III:MATII ratios correlate negatively with cell proliferation and genomic instability, and positively with apoptosis and global DNA methylation. This suggests that SAM decrease and MATs deregulation represent potential therapeutic targets for HCC. Finally, MATI/III:MATII ratio strongly predicts patients' survival length suggesting that MAT1A:MAT2A expression ratio is a putative prognostic marker for human HCC. Copyright © 2013 European Association for the Study of the Liver. Published by Elsevier B.V. All rights reserved.

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

Language and Culture in the Multi-Ethnic Community: Spoken-Language Assessment

ERIC Educational Resources Information Center

Matluck, Joseph H.; Mace-Matluck, Betty J.

1975-01-01

Describes the research approach used to develop the MAT-SEA-CAL Oral Proficiency tests designed by the authors. Language test performance depends on both language proficiency and knowledge of the culture. (TL)

Polyamine and methionine adenosyltransferase 2A crosstalk in human colon and liver cancer

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

Tomasi, Maria Lauda; USC Research Center for Liver Diseases, Keck School of Medicine of University of Southern California, Los Angeles, CA 90033; The Southern California Research Center for Alcoholic and Pancreatic Diseases and Cirrhosis, Keck School of Medicine of University of Southern California, Los Angeles, CA 90033

Methionine adenosyltransferase (MAT) is an essential enzyme that is responsible for the biosynthesis of S-adenosylmethionine (SAMe), the principal methyl donor and precursor of polyamines. MAT1A is expressed in normal liver and MAT2A is expressed in all extrahepatic tissues. MAT2A expression is increased in human colon cancer and in colon cancer cells treated with mitogens, whereas silencing MAT2A resulted in apoptosis. The aim of the current work was to examine the mechanism responsible for MAT2A-dependent growth and apoptosis. We found that in RKO (human adenocarcinoma cell line) cells, MAT2A siRNA treatment lowered cellular SAMe and putrescine levels by 70–75%, increased apoptosismore » and inhibited growth. Putrescine supplementation blunted significantly MAT2A siRNA-induced apoptosis and growth suppression. Putrescine treatment (100 pmol/L) raised MAT2A mRNA level to 4.3-fold of control, increased the expression of c-Jun and c-Fos and binding to an AP-1 site in the human MAT2A promoter and the promoter activity. In human colon cancer specimens, the expression levels of MAT2A, ornithine decarboxylase (ODC), c-Jun and c-Fos are all elevated as compared to adjacent non-tumorous tissues. Overexpression of ODC in RKO cells also raised MAT2A mRNA level and MAT2A promoter activity. ODC and MAT2A are also overexpressed in liver cancer and consistently, similar MAT2A-ODC-putrescine interactions and effects on growth and apoptosis were observed in HepG2 cells. In conclusion, there is a crosstalk between polyamines and MAT2A. Increased MAT2A expression provides more SAMe for polyamines biosynthesis; increased polyamine (putrescine in this case) can activate MAT2A at the transcriptional level. This along with increased ODC expression in cancer all feed forward to further enhance the proliferative capacity of the cancer cell. -- Highlights: • MAT2A knockdown depletes putrescine and leads to apoptosis. • Putrescine attenuates MAT2A knockdown-induced apoptosis and growth suppression. • Putrescine induces AP-1, which activates MAT2A promoter to increase its expression. • Putrescine increases ornithine decarboxylase expression, which induce MAT2A promoter. • Expression of MAT2A correlates with that of ornithine decarboxylase in colon cancer.« less

Polycaprolactone nanofibres loaded with 20(S)-protopanaxadiol for in vitro and in vivo anti-tumour activity study

PubMed Central

Liu, Dan-qing; Cheng, Zhi-qiang; Feng, Qing-jie; Li, He-jie; Ye, Shu-feng

2018-01-01

In this work, 20(S)-protopanaxadiol (PPD)-loaded polycaprolactone (PCL) nanofibres were successfully fabricated by the electrospinning technique using Tween 80 as a solubilizer. Firstly, smooth and continuous nanofibres were collected using suitable solvents and appropriate spinning conditions. Secondly, nanofibre mats were characterized by scanning electron microscopy, thermogravimetric (TG) analysis, Fourier transform infrared spectroscopy and mechanical testing. Finally, nanofibrous membranes were evaluated using water contact angle, in vitro drug release, biodegradation test, in vitro and in vivo anti-tumour activity and cell apoptosis assay. Scanning electron microscopic observations indicated that the diameter of the drug-loaded nanofibres increased with the increase of drug concentration. TG analysis and mechanical test showed that nanofibres were equipped with great thermal and mechanical properties. Biodegradation test exhibited that the structure of fabricated nanofibres had a certain degree of change after 15 days. An in vitro release study showed that PPD from drug-loaded nanofibres could be released in a sustained and prolonged mode. The cytotoxic effect of drug-loaded nanofibre mats examined on human laryngeal carcinoma cells (Hep-2 cells) demonstrated that the prepared nanofibres had a remarkable anti-tumour effect. Meanwhile, the drug-loaded fibre mats showed a super anti-tumour effect in an in vivo anti-tumour study. All in all, PCL nanofibres could be a potential carrier of PPD for cancer treatment. PMID:29892448

Fabrication and Characterization of a Composite Fibrous Construct with Photocatalytic Activity and Physical Adsorption Capabilities for Water Treatment Applications

NASA Astrophysics Data System (ADS)

Everett, Dominique Tresten

Environmental pollution has exponentially increased since the industrial revolution due to many advancements in technology which has led to the use of innovative materials. In the manufacturing and fabrication processes of modern technology, society has become victim to the contamination via production byproducts. This issue needs to be addressed with greater efforts to solve this worldwide issue to ultimately minimize these potential detrimental public health effects and improve environmental preservation. This research study focuses on contributing to efforts with minimizing wastewater pollution by the fabrication and characterization of complex porosity gradient fibrous membrane that purifies via particle size exclusion, photocatalysis and also physical adsorption. The membrane consists of a nano/mico-fibrous composite network fabricated by side-by-side electrospinning for the initial aim of this study. The experimental setup resulted in a novel morphological structure that yields exceptional catalytic responsiveness in visible light compared to conventional materials that are currently used. Subsequently, there is a thermal bonded discontinuous polymeric microfibrous mat with activated carbon granule incorporation to serve as a superior mechanical stability agent with high physical adsorption capability. The second aim was to investigate fiber length dependence on mechano-morphological properties while achieving adequate activated carbon during processing when subjected to post-fabrication thermal bonding of resulting mat. Furthermore, the third aim was to fabricate the complex construct by combining methods from the first and second aim to assemble a system that filters through two water purification mechanisms (photocatalysis and physical adsorption) simultaneously. This study was investigated for characterization and verification for various aspects such as morphological analyses, crystallographic assessments, mechanical testing, while defining construct functionality by examining adsorption and photodegradation performance.

Mechanical and thermal properties of biocomposites from nonwoven industrial Fique fiber mats with Epoxy Resin and Linear Low Density Polyethylene

NASA Astrophysics Data System (ADS)

Hidalgo-Salazar, Miguel A.; Correa, Juan P.

2018-03-01

In this work Linear Low Density Polyethylene-nonwoven industrial Fique fiber mat (LLDPE-Fique) and Epoxy Resin-nonwoven industrial Fique fiber mat (EP-Fique) biocomposites were prepared using thermocompression and resin film infusion processes. Neat polymeric matrices and its biocomposites were tested following ASTM standards in order to evaluate tensile and flexural mechanical properties. Also, thermal behavior of these materials has been studied by differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). Tensile and flexural test revealed that nonwoven Fique reinforced composites exhibited higher modulus and strength but lower deformation capability as compared with LLDPE and EP neat matrices. TG thermograms showed that nonwoven Fique fibers incorporation has an effect on the thermal stability of the composites. On the other hand, Fique fibers did not change the crystallization and melting processes of the LLDPE matrix but restricts the motion of EP macromolecules chains thus increases the Tg of the EP-Fique composite. Finally, this work opens the possibility of considering non-woven Fique fibers as a reinforcement material with a high potential for the manufacture of biocomposites for automotive applications. In addition to the processing test specimens, it was also possible to manufacture a part of LLDPE-Fique, and one part of EP-Fique.

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

Silk fibroin in tissue engineering.

PubMed

Kasoju, Naresh; Bora, Utpal

2012-07-01

Tissue engineering (TE) is a multidisciplinary field that aims at the in vitro engineering of tissues and organs by integrating science and technology of cells, materials and biochemical factors. Mimicking the natural extracellular matrix is one of the critical and challenging technological barriers, for which scaffold engineering has become a prime focus of research within the field of TE. Amongst the variety of materials tested, silk fibroin (SF) is increasingly being recognized as a promising material for scaffold fabrication. Ease of processing, excellent biocompatibility, remarkable mechanical properties and tailorable degradability of SF has been explored for fabrication of various articles such as films, porous matrices, hydrogels, nonwoven mats, etc., and has been investigated for use in various TE applications, including bone, tendon, ligament, cartilage, skin, liver, trachea, nerve, cornea, eardrum, dental, bladder, etc. The current review extensively covers the progress made in the SF-based in vitro engineering and regeneration of various human tissues and identifies opportunities for further development of this field. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Parallel Loss of Plastid Introns and Their Maturase in the Genus Cuscuta

PubMed Central

McNeal, Joel R.; Kuehl, Jennifer V.; Boore, Jeffrey L.; Leebens-Mack, Jim; dePamphilis, Claude W.

2009-01-01

Plastid genome content and arrangement are highly conserved across most land plants and their closest relatives, streptophyte algae, with nearly all plastid introns having invaded the genome in their common ancestor at least 450 million years ago. One such intron, within the transfer RNA trnK-UUU, contains a large open reading frame that encodes a presumed intron maturase, matK. This gene is missing from the plastid genomes of two species in the parasitic plant genus Cuscuta but is found in all other published land plant and streptophyte algal plastid genomes, including that of the nonphotosynthetic angiosperm Epifagus virginiana and two other species of Cuscuta. By examining matK and plastid intron distribution in Cuscuta, we add support to the hypothesis that its normal role is in splicing seven of the eight group IIA introns in the genome. We also analyze matK nucleotide sequences from Cuscuta species and relatives that retain matK to test whether changes in selective pressure in the maturase are associated with intron deletion. Stepwise loss of most group IIA introns from the plastid genome results in substantial change in selective pressure within the hypothetical RNA-binding domain of matK in both Cuscuta and Epifagus, either through evolution from a generalist to a specialist intron splicer or due to loss of a particular intron responsible for most of the constraint on the binding region. The possibility of intron-specific specialization in the X-domain is implicated by evidence of positive selection on the lineage leading to C. nitida in association with the loss of six of seven introns putatively spliced by matK. Moreover, transfer RNA gene deletion facilitated by parasitism combined with an unusually high rate of intron loss from remaining functional plastid genes created a unique circumstance on the lineage leading to Cuscuta subgenus Grammica that allowed elimination of matK in the most species-rich lineage of Cuscuta. PMID:19543388

Parallel loss of plastid introns and their maturase in the genus Cuscuta.

PubMed

McNeal, Joel R; Kuehl, Jennifer V; Boore, Jeffrey L; Leebens-Mack, Jim; dePamphilis, Claude W

2009-06-19

Plastid genome content and arrangement are highly conserved across most land plants and their closest relatives, streptophyte algae, with nearly all plastid introns having invaded the genome in their common ancestor at least 450 million years ago. One such intron, within the transfer RNA trnK-UUU, contains a large open reading frame that encodes a presumed intron maturase, matK. This gene is missing from the plastid genomes of two species in the parasitic plant genus Cuscuta but is found in all other published land plant and streptophyte algal plastid genomes, including that of the nonphotosynthetic angiosperm Epifagus virginiana and two other species of Cuscuta. By examining matK and plastid intron distribution in Cuscuta, we add support to the hypothesis that its normal role is in splicing seven of the eight group IIA introns in the genome. We also analyze matK nucleotide sequences from Cuscuta species and relatives that retain matK to test whether changes in selective pressure in the maturase are associated with intron deletion. Stepwise loss of most group IIA introns from the plastid genome results in substantial change in selective pressure within the hypothetical RNA-binding domain of matK in both Cuscuta and Epifagus, either through evolution from a generalist to a specialist intron splicer or due to loss of a particular intron responsible for most of the constraint on the binding region. The possibility of intron-specific specialization in the X-domain is implicated by evidence of positive selection on the lineage leading to C. nitida in association with the loss of six of seven introns putatively spliced by matK. Moreover, transfer RNA gene deletion facilitated by parasitism combined with an unusually high rate of intron loss from remaining functional plastid genes created a unique circumstance on the lineage leading to Cuscuta subgenus Grammica that allowed elimination of matK in the most species-rich lineage of Cuscuta.

Evaluation of In-House and Commercial Serological Tests for Diagnosis of Human Tularemia

PubMed Central

Yanes, Hadjila; Hennebique, Aurélie; Pelloux, Isabelle; Boisset, Sandrine; Bicout, Dominique J.; Caspar, Yvan

2017-01-01

ABSTRACT Tularemia is a zoonosis caused by the bacterium Francisella tularensis. Its specific diagnosis remains based on serological methods, while F. tularensis is rarely detected in clinical samples by culture or PCR. The aim of the present study was to evaluate the performance of the Serion enzyme-linked immunosorbent assay (ELISA) classic Francisella tularensis IgG and IgM tests (Virion/Serion GmbH Institute, Würzburg, Germany) and the VIRapid tularemia immunochromatographic test (ICT) (Vircell, Granada, Spain) compared to that of the in-house microagglutination test (MAT) and indirect immunofluorescence assay (IFA) currently used at the French National Reference Center for Francisella. We evaluated 256 consecutive sera from 208 patients, including 51 confirmed and 23 probable tularemia cases, and 134 control patients not infected with F. tularensis. The IFA tests displayed 72.5% sensitivity for IgM (cutoff titer ≥80) and 74.5% for IgG (cutoff titer ≥160), and 99.3% specificity for both IgM and IgG. Using cutoffs advocated by the manufacturer, the Serion ELISAs displayed 88.2% sensitivity for IgM and 86.3% for IgG antibodies; specificity was 94.8% for IgM and 95.5% for IgG. Compared to MAT and IFA tests, the Serion ELISAs allowed earlier detection of specific antibodies (1 to 2 weeks versus 2 to 3 weeks after the onset of symptoms). The ICT sensitivity and specificity were 90% and 83.6%, respectively, when considering the cutoff advocated by the manufacturer. In conclusion, the Serion ELISAs are useful as screening tests for tularemia diagnosis, but additional confirmatory tests (such as MAT and IFA) are needed, especially in areas of low endemicity. PMID:29118164

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.

Hybrid PV HgCdTe Detectors: Technology Reliability and Failure Physics Program

DTIC Science & Technology

1988-01-01

interconnect reliability. 3-1 8912-16 SECTION 4 ACKNOWLEDGEMENTS The authors would like to thank Dr. Marion Reine, Dr. Andrei Szilagyi , Nancy Hartle... Szilagyi , Mat. Res. Soc. Syrnp. Proc. 69, 257, (1986) 9. Private communications with Andrei Szilagy. 10. R.J. Briggs, J.W. Marciniec, P.H. Zimmermann and

Calendar of Selected Aeronautical and Space Meetings (Calendrier des Manifestations Aeronautiques et Spatiales (Selection). Juillet-July 1984.

DTIC Science & Technology

1984-06-01

Structures, Mat~riaux et M~canique appliquce 47 08 - Physique de l’Atmnosph~re et Environnement terrestre 62 09 - Information, Documentation et...University Institute of Technology: Box 534,75121 Uppsala SW UW University of Wisconsin: Madison, WI 53706 US VDE Verbend Deutacher Elektroteclker

GCD TechPort Data Sheets Thermal Protection System Materials (TPSM) Project

NASA Technical Reports Server (NTRS)

Chinnapongse, Ronald L.

2014-01-01

The Thermal Protection System Materials (TPSM) Project consists of three distinct project elements: the 3-Dimensional Multifunctional Ablative Thermal Protection System (3D MAT) project element; the Conformal Ablative Thermal Protection System (CA-TPS) project element; and the Heatshield for Extreme Entry Environment Technology (HEEET) project element. 3D MAT seeks to design, develop and deliver a game changing material solution based on 3-dimensional weaving and resin infusion approach for manufacturing a material that can function as a robust structure as well as a thermal protection system. CA-TPS seeks to develop and deliver a conformal ablative material designed to be efficient and capable of withstanding peak heat flux up to 500 W/ sq cm, peak pressure up to 0.4 atm, and shear up to 500 Pa. HEEET is developing a new ablative TPS that takes advantage of state-of-the-art 3D weaving technologies and traditional manufacturing processes to infuse woven preforms with a resin, machine them to shape, and assemble them as a tiled solution on the entry vehicle substructure or heatshield.

Presence and Functionality of Mating Type Genes in the Supposedly Asexual Filamentous Fungus Aspergillus oryzae

PubMed Central

Wada, Ryuta; Maruyama, Jun-ichi; Yamaguchi, Haruka; Yamamoto, Nanase; Wagu, Yutaka; Paoletti, Mathieu; Archer, David B.; Dyer, Paul S.

2012-01-01

The potential for sexual reproduction in Aspergillus oryzae was assessed by investigating the presence and functionality of MAT genes. Previous genome studies had identified a MAT1-1 gene in the reference strain RIB40. We now report the existence of a complementary MAT1-2 gene and the sequencing of an idiomorphic region from A. oryzae strain AO6. This allowed the development of a PCR diagnostic assay, which detected isolates of the MAT1-1 and MAT1-2 genotypes among 180 strains assayed, including industrial tane-koji isolates. Strains used for sake and miso production showed a near-1:1 ratio of the MAT1-1 and MAT1-2 mating types, whereas strains used for soy sauce production showed a significant bias toward the MAT1-2 mating type. MAT1-1 and MAT1-2 isogenic strains were then created by genetic manipulation of the resident idiomorph, and gene expression was compared by DNA microarray and quantitative real-time PCR (qRT-PCR) methodologies under conditions in which MAT genes were expressed. Thirty-three genes were found to be upregulated more than 10-fold in either the MAT1-1 host strain or the MAT1-2 gene replacement strain relative to each other, showing that both the MAT1-1 and MAT1-2 genes functionally regulate gene expression in A. oryzae in a mating type-dependent manner, the first such report for a supposedly asexual fungus. MAT1-1 expression specifically upregulated an α-pheromone precursor gene, but the functions of most of the genes affected were unknown. The results are consistent with a heterothallic breeding system in A. oryzae, and prospects for the discovery of a sexual cycle are discussed. PMID:22327593

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

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.

BCI`s RBSM test methods: Eight years in the making

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

NONE

1993-03-01

RBSM stands for recombinant battery separator mat. This is the acronym chosen after a lot of debate during eight years of committee work to develop test methods to characterize separators which are used in valve regulated lead acid batteries. This paper discusses the test methods.

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.

An Intrusion Detection System for the Protection of Railway Assets Using Fiber Bragg Grating Sensors

PubMed Central

Catalano, Angelo; Bruno, Francesco Antonio; Pisco, Marco; Cutolo, Antonello; Cusano, Andrea

2014-01-01

We demonstrate the ability of Fiber Bragg Gratings (FBGs) sensors to protect large areas from unauthorized activities in railway scenarios such as stations or tunnels. We report on the technological strategy adopted to protect a specific depot, representative of a common scenario for security applications in the railway environment. One of the concerns in the protection of a railway area centers on the presence of rail-tracks, which cannot be obstructed with physical barriers. We propose an integrated optical fiber system composed of FBG strain sensors that can detect human intrusion for protection of the perimeter combined with FBG accelerometer sensors for protection of rail-track access. Several trials were carried out in indoor and outdoor environments. The results demonstrate that FBG strain sensors bonded under a ribbed rubber mat enable the detection of intruder break-in via the pressure induced on the mat, whereas the FBG accelerometers installed under the rails enable the detection of intruders walking close to the railroad tracks via the acoustic surface waves generated by footsteps. Based on a single enabling technology, this integrated system represents a valuable intrusion detection system for railway security and could be integrated with other sensing functionalities in the railway field using fiber optic technology. PMID:25268920

Implications of a 3.472–3.333 Gyr-old subaerial microbial mat from the Barberton greenstone belt, South Africa for the UV environmental conditions on the early Earth

PubMed Central

Westall, Frances; de Ronde, Cornel E.J; Southam, Gordon; Grassineau, Nathalie; Colas, Maggy; Cockell, Charles; Lammer, Helmut

2006-01-01

Modelling suggests that the UV radiation environment of the early Earth, with DNA weighted irradiances of about three orders of magnitude greater than those at present, was hostile to life forms at the surface, unless they lived in specific protected habitats. However, we present empirical evidence that challenges this commonly held view. We describe a well-developed microbial mat that formed on the surface of volcanic littoral sediments in an evaporitic environment in a 3.5–3.3 Ga-old formation from the Barberton greenstone belt. Using a multiscale, multidisciplinary approach designed to strongly test the biogenicity of potential microbial structures, we show that the mat was constructed under flowing water by 0.25 μm filaments that produced copious quantities of extracellular polymeric substances, representing probably anoxygenic photosynthesizers. Associated with the mat is a small colony of rods–vibroids that probably represent sulphur-reducing bacteria. An embedded suite of evaporite minerals and desiccation cracks in the surface of the mat demonstrates that it was periodically exposed to the air in an evaporitic environment. We conclude that DNA-damaging UV radiation fluxes at the surface of the Earth at this period must either have been low (absorbed by CO2, H2O, a thin organic haze from photo-dissociated CH4, or SO2 from volcanic outgassing; scattered by volcanic, and periodically, meteorite dust, as well as by the upper layers of the microbial mat) and/or that the micro-organisms exhibited efficient gene repair/survival strategies. PMID:17008224

Primary care models for treating opioid use disorders: What actually works? A systematic review

PubMed Central

Klasa, Katarzyna; Bush, Christopher; Heisler, Michele; Chopra, Vineet; Bohnert, Amy

2017-01-01

Background Primary care-based models for Medication-Assisted Treatment (MAT) have been shown to reduce mortality for Opioid Use Disorder (OUD) and have equivalent efficacy to MAT in specialty substance treatment facilities. Objective The objective of this study is to systematically analyze current evidence-based, primary care OUD MAT interventions and identify program structures and processes associated with improved patient outcomes in order to guide future policy and implementation in primary care settings. Data sources PubMed, EMBASE, CINAHL, and PsychInfo. Methods We included randomized controlled or quasi experimental trials and observational studies evaluating OUD treatment in primary care settings treating adult patient populations and assessed structural domains using an established systems engineering framework. Results We included 35 interventions (10 RCTs and 25 quasi-experimental interventions) that all tested MAT, buprenorphine or methadone, in primary care settings across 8 countries. Most included interventions used joint multi-disciplinary (specialty addiction services combined with primary care) and coordinated care by physician and non-physician provider delivery models to provide MAT. Despite large variability in reported patient outcomes, processes, and tasks/tools used, similar key design factors arose among successful programs including integrated clinical teams with support staff who were often advanced practice clinicians (nurses and pharmacists) as clinical care managers, incorporating patient “agreements,” and using home inductions to make treatment more convenient for patients and providers. Conclusions The findings suggest that multidisciplinary and coordinated care delivery models are an effective strategy to implement OUD treatment and increase MAT access in primary care, but research directly comparing specific structures and processes of care models is still needed. PMID:29040331

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.

Release of metronidazole from electrospun poly(L-lactide-co-D/L-lactide) fibers for local periodontitis treatment.

PubMed

Reise, Markus; Wyrwa, Ralf; Müller, Ulrike; Zylinski, Matthias; Völpel, Andrea; Schnabelrauch, Matthias; Berg, Albrecht; Jandt, Klaus D; Watts, David C; Sigusch, Bernd W

2012-02-01

We aimed to achieve detailed biomaterials characterization of a drug delivery system for local periodontitis treatment based on electrospun metronidazole-loaded resorbable polylactide (PLA) fibers. PLA fibers loaded with 0.1-40% (w/w) MNA were electrospun and were characterized by SEM and DSC. HPLC techniques were used to analyze the release profiles of metronidazole (MNA) from these fibers. The antibacterial efficacy was determined by measuring inhibition zones of drug-containing aliquots from the same electrospun fiber mats in an agar diffusion test. Three pathogenic periodontal bacterial strains: Fusobacterium nucleatum, Aggregatibacter actinomycetemcomitans and Porphyromonas gingivalis were studied. Cytotoxicity testing was performed with human gingival fibroblasts by: (i) counting viable cells via live/dead staining methods and (ii) by exposing cells directly onto the surface of MNA-loaded fibers. MNA concentration influenced fiber diameters and thus w/w surface areas: diameter being minimal and area maximal at 20% MNA. HPLC showed that these 20% MNA fibers had the fastest initial MNA release. From the third day, MNA release was slower and nearly linear with time. All fiber mats released 32-48% of their total drug content within the first 7 days. Aliquots of media taken from the fiber mats inhibited the growth of all three bacterial strains. MNA released up to the 28th day from fiber mats containing 40% MNA significantly decreased the viability of F. nucleatum and P. gingivalis and up to the 2nd day also for the resistant A. actinomycetemcomitans. All of the investigated fibers and aliquots showed excellent cytocompatibility. This study shows that MNA-loaded electrospun fiber mats represent an interesting class of resorbable drug delivery systems. Sustained drug release properties and cytocompatibility suggest their potential clinical applicability for the treatment of periodontal diseases. Copyright © 2011 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

Higher urine 1-hydroxy pyrene glucuronide (1-OHPG) is associated with tobacco smoke exposure and drinking maté in healthy subjects from Rio Grande do Sul, Brazil

PubMed Central

Fagundes, Renato B; Abnet, Christian C; Strickland, Paul T; Kamangar, Farin; Roth, Mark J; Taylor, Philip R; Dawsey, Sanford M

2006-01-01

Background The highest rates of esophageal squamous cell carcinoma (ESCC) in Brazil occur in Rio Grande do Sul, the most southern state, which has incidence rates of 20.4/100,000/year for men and 6.5/100,000/year for women. Exposure to carcinogenic polycyclic aromatic hydrocarbons (PAHs) through tobacco smoke and other sources may increase the risk of ESCC. The aims of the current study were to investigate the degree and sources of PAH exposure of the inhabitants of this region of southern Brazil. Methods Two hundred healthy adults (half smokers, half non smokers, half male and half female) were recruited, given a standardized questionnaire, and asked to provide a urine sample for measurement of 1-hydroxypyrene glucuronide (1-OHPG), a PAH metabolite). Urine 1-OHPG concentrations were measured using immunoaffinity chromatography and synchronous fluorescence spectroscopy and urine cotinine was measured using a dipstick test. We examined factors associated with 1-OHPG concentration using Wilcoxon tests and multiple linear regression. Results Urine 1-hydroxypyrene glucuronide (1-OHPG) was successfully measured on 199 subjects. The median (interquartile range) of urine 1-OHPG in the 199 participants was 2.09 pmol/mL (0.51, 5.84). Tobacco smoke exposure and maté drinking were statistically significantly associated with higher urine 1-OHPG concentrations in the multivariate linear regression model. Conclusion Tobacco smoke and maté both contribute to high levels of benzo[a]pyrene exposure in the people of southern Brazil. This high PAH exposure may contribute to the high rates of ESCC observed in this population. The increased urine 1-OHPG concentrations associated with maté suggest that contaminants, not just thermal injury, may help explain the increased risk of ESCC previously reported for maté consumption. PMID:16729889

Medication-assisted treatment in criminal justice agencies affiliated with the criminal justice-drug abuse treatment studies (CJ-DATS): availability, barriers, and intentions.

PubMed

Friedmann, Peter D; Hoskinson, Randall; Gordon, Michael; Schwartz, Robert; Kinlock, Timothy; Knight, Kevin; Flynn, Patrick M; Welsh, Wayne N; Stein, Lynda A R; Sacks, Stanley; O'Connell, Daniel J; Knudsen, Hannah K; Shafer, Michael S; Hall, Elizabeth; Frisman, Linda K

2012-01-01

Medication-assisted treatment (MAT) is underutilized in the treatment of drug-dependent, criminal justice populations. This study surveyed criminal justice agencies affiliated with the Criminal Justice Drug Abuse Treatment Studies (CJ-DATS) to assess use of MAT and factors influencing use of MAT. A convenience sample (N = 50) of criminal justice agency respondents (e.g., jails, prisons, parole/probation, and drug courts) completed a survey on MAT practices and attitudes. Pregnant women and individuals experiencing withdrawal were most likely to receive MAT for opiate dependence in jail or prison, whereas those reentering the community from jail or prison were the least likely to receive MAT. Factors influencing use of MAT included criminal justice preferences for drug-free treatment, limited knowledge of the benefits of MAT, security concerns, regulations prohibiting use of MAT for certain agencies, and lack of qualified medical staff. Differences across agency type in the factors influencing use and perceptions of MAT were also examined. MAT use is largely limited to detoxification and maintenance of pregnant women in criminal justice settings. Use of MAT during the community reentry period is minimal. Addressing inadequate knowledge and negative attitudes about MAT may increase its adoption, but better linkages to community pharmacotherapy during the reentry period might overcome other issues, including security, liability, staffing, and regulatory concerns. The CJ-DATS collaborative MAT implementation study to address inadequate knowledge, attitudes, and linkage will be described.

Maternal inheritance of mitochondria: multipolarity, multiallelism and hierarchical transmission of mitochondrial DNA in the true slime mold Physarum polycephalum.

PubMed

Moriyama, Yohsuke; Kawano, Shigeyuki

2010-03-01

Direct evidence of digestion of paternal mitochondrial DNA (mtDNA) has been found in the true slime mold Physarum polycephalum. This is the first report on the selective digestion of mtDNA inside the zygote, and is striking evidence for the mechanism of maternal inheritance of mitochondria. Moreover, two mitochondrial nuclease activities were detected in this organism as-candidates for the nucleases responsible for selective digestion of mtDNA. In the true slime mold, there is an additional-feature of the uniparental inheritance of mitochondria.Although mitochondria are believed to be inherited from the maternal lineage in nearly all eukaryotes, the mating types of the true slime mold P. polycephalum is not restricted to two: there are three mating loci--matA, matB,and matC--and these loci have 16, 15, and 3 alleles,-respectively. Interestingly, the transmission patterns of mtDNA are determined by the matA locus, in a hierarchical-fashion (matA hierarchy) as follows: matA7[matA2[matA11[matA12[matA15/matA16[matA1[matA6.The strain possessing the higher status of matA would be the mtDNA donor in crosses. Furthermore, we have found that some crosses showed biparental inheritance of mitochondria.This review describes the phenomenon of hierarchical transmission of mtDNA in true slime molds, and discusses the presumed molecular mechanism of maternal and biparental inheritance.

The Four-Day School Week: An Examination of Long-Term Student Achievement at the Middle and Secondary Levels

ERIC Educational Resources Information Center

Fagergren, Peter J.

2003-01-01

Academic achievement under a four-day school week is compared to the traditional five-day school week. Test scores from the CAT [California Achievement Test], ITBS [Iowa Test of Basic Skills], TASK [Stanford Test of Academic Skills], SAT [Stanford Achievement Test], TAP [Tests of Academic Proficiency], and MAT [Metropolitan Achievement Test] were…

Examination of the Hepatitis C Virus care continuum among individuals with an opioid use disorder in substance use treatment.

PubMed

Brown, Jennifer L; Gause, Nicole K; Lewis, Daniel; Winhusen, Theresa

2017-05-01

Hepatitis C Virus (HCV) risk is elevated for individuals with an opioid use disorder (OUD). Routine HCV testing is recommended for high-risk individuals, including those with an injection drug use history. HCV antibody testing addresses the first step in the HCV treatment care cascade, with uptake and completion of HCV treatment among individuals with chronic HCV as the optimal care cascade endpoint. The aim of this study was to characterize self-reported HCV treatment cascade outcomes among individuals with an OUD in outpatient medication assisted treatment (MAT). Individuals receiving methadone or buprenorphine treatment (N=202, 67.8% female, M age=35.0, SD=8.4) completed a brief, anonymous paper-and-pencil survey examining self-reported history of HCV testing, diagnosis, and treatment. Descriptive statistics characterized HCV treatment cascade outcomes. A majority (79.3%) endorsed a lifetime HCV testing history; 34.9% were tested for HCV during the past year. Of those with a lifetime HCV testing history, 42.7% indicated they have been told they have HCV (n=67/157), with 21% (n=14/67) of those individuals reporting that they have been told they have chronic HCV, and 71.4% (n=10/14) of those with chronic HCV reporting receipt of HCV treatment. Results underscore gaps in the HCV care continuum among individuals with OUD in MAT. Interventions to increase uptake of HCV testing, communication of HCV diagnostic and treatment information by medical providers, linkage to HCV medical care, and uptake and adherence to HCV treatment are urgently needed, particularly among individuals with an OUD in MAT. Copyright © 2017 Elsevier Inc. All rights reserved.

Assessment of the nutrient removal effectiveness of floating treatment wetlands applied to urban retention ponds.

PubMed

Wang, Chih-Yu; Sample, David J

2014-05-01

The application of floating treatment wetlands (FTWs) in point and non-point source pollution control has received much attention recently. Although the potential of this emerging technology is supported by various studies, quantifying FTW performance in urban retention ponds remains elusive due to significant research gaps. Actual urban retention pond water was utilized in this mesocosm study to evaluate phosphorus and nitrogen removal efficiency of FTWs. Multiple treatments were used to investigate the contribution of each component in the FTW system with a seven-day retention time. The four treatments included a control, floating mat, pickerelweed (Pontederia cordata L.), and softstem bulrush (Schoenoplectus tabernaemontani). The water samples collected on Day 0 (initial) and 7 were analyzed for total phosphorus (TP), total particulate phosphorus, orthophosphate, total nitrogen (TN), organic nitrogen, ammonia nitrogen, nitrate-nitrite nitrogen, and chlorophyll-a. Statistical tests were used to evaluate the differences between the four treatments. The effects of temperature on TP and TN removal rates of the FTWs were described by the modified Arrhenius equation. Our results indicated that all three FTW designs, planted and unplanted floating mats, could significantly improve phosphorus and nitrogen removal efficiency (%, E-TP and E-TN) compared to the control treatment during the growing season, i.e., May through August. The E-TP and E-TN was enhanced by 8.2% and 18.2% in the FTW treatments planted with the pickerelweed and softstem bulrush, respectively. Organic matter decomposition was likely to be the primary contributor of nutrient removal by FTWs in urban retention ponds. Such a mechanism is fostered by microbes within the attached biofilms on the floating mats and plant root surfaces. Among the results of the four treatments, the FTWs planted with pickerelweed had the highest E-TP, and behaved similarly with the other two FTW treatments for nitrogen removal during the growth period. The temperature effects described by the modified Arrhenius equation revealed that pickerelweed is sensitive to temperature and provides considerable phosphorus removal when water temperature is greater than 25 °C. However, the nutrient removal effectiveness of this plant species may be negligible for water temperatures below 15 °C. The study also assessed potential effects of shading from the FTW mats on water temperature, DO, pH, and attached-to-substrate periphyton/vegetation. Copyright © 2014 Elsevier Ltd. All rights reserved.

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, indicating recovery. When mobile animals were considered alone, there was an exponential relationship between the percentage of animals on floating mats, relative to the total number on both mat types, and hypoxia. The occupation of floating mats by invertebrates at all times, and their dominance there during hypoxia/anoxia, provides support for the hypothesis that floating mats are refugia. PMID:28348927

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.

Use of Lightweight Cellular Mats to Reduce the Settlement of Structure on Soft Soil

NASA Astrophysics Data System (ADS)

Ganasan, R.; Lim, A. J. M. S.; Wijeyesekera, D. C.

2016-07-01

Construction of structures on soft soils gives rise to some difficulties in Malaysia and other country especially in settlement both in short and long term. The focus of this research is to minimize the differential and non-uniform settlement on peat soil with the use of an innovative cellular mat. The behaviour and performance of the lightweight geo-material (in block form) is critically investigated and in particular the use as a fill in embankment on soft ground. Hemic peat soil, sponge and innovative cellular mat will be used as the main material in this study. The monitoring in settlement behavior from this part of research will be done as laboratory testing only. The uneven settlement in this problem was uniquely monitored photographically using spot markers. In the end of the research, it is seen that the innovative cellular mat has reduce the excessive and differential settlement up to 50% compare to flexible and rigid foundations. This had improve the stiffness of soils as well as the porous contain in cellular structure which help in allowing water/moisture to flow through in or out thus resulting in prevent the condition of floating.

Semiochemical mediated enhancement of males to complement sterile insect technique in management of the tephritid pest Bactrocera tryoni (Froggatt).

PubMed

Khan, Mohammed Abul Monjur; Manoukis, Nicholas C; Osborne, Terry; Barchia, Idris M; Gurr, Geoff M; Reynolds, Olivia L

2017-10-17

Queensland fruit fly, Bactrocera tryoni (Froggatt), is the most significant pest of Australia's $9 billion horticulture industry. The sterile insect technique (SIT) and cue-lure (a synthetic analogue of raspberry ketone (RK))-based male annihilation technique (MAT) are two of the most effective management tools against this pest. However, combining these two approaches is considered incompatible as MAT kills sterile and 'wild' males indiscriminately. In the present study we tested the effect of pre-release feeding of B. tryoni on RK on their post-release survival and response to MAT in field cages and in a commercial orchard. In both settings, survival was higher for RK supplemented adults compared to control (i.e. RK denied) adults. A lower number of RK supplemented sterile males were recaptured in MAT baited traps in both the field cages and orchard trials compared to RK denied sterile males. The advantage of this novel "male replacement" approach (relatively selective mortality of wild males at lure-baited traps while simultaneously releasing sterile males) is increasing the ratio of sterile to wild males in the field population, with potential for reducing the number of sterile males to be released.

Serotype and mating type characterization of Cryptococcus neoformans by multiplex PCR.

PubMed

Carvalho, Vívian Gonçalves; Terceti, Mateus Souza; Dias, Amanda Latercia Tranches; Paula, Claudete Rodrigues; Lyon, Juliana Pereira; de Siqueira, Antônio Martins; Franco, Marília Caixeta

2007-01-01

Cryptococcus neoformans is an encapsulated yeast, etiological agent of cryptococcosis. The species is commonly associated with pigeon droppings and plant materials. The aim of the present work was to verify the presence of the yeast in pigeon droppings, and to identify the isolates obtained in serotypes and mating types (MAT). Ten samples of pigeon droppings were collected in the rural area of the city of Alfenas, Brazil. Samples were inoculated in agar Niger medium for fungal isolation and 22 isolates with characteristics of C. neoformans were obtained. The serotypes and MAT were determined by multiplex PCR using specific primers. Serotypes were also determined by using the Kit Crypto Check. Among the 22 samples evaluated, eight were identified as C. neoformans by classic identification tests. These samples were characterized as serotype A by the Kit Crypto check and as serotype A MAT alpha by the multiplex PCR. The present study reinforces the evidence that pigeon droppings are a reservoir for C. neoformans and confirms the prevalence of C. neoformans var. grubii (A alpha) among environmental isolates. It also demonstrates that multiplex PCR is an acceptable alternative for serotype analysis because it reduces the costs for each reaction and analyses serotype and MAT simultaneously.

Fe-oxidizing microbes are hydrothermal vent ecosystem engineers at the Loihi Seamount (Invited)

NASA Astrophysics Data System (ADS)

Chan, C. S.; McAllister, S.; Leavitt, A.; Emerson, D.; Moyer, C. L.; Glazer, B. T.

2013-12-01

Microaerophilic Fe-oxidizing microorganisms (FeOM) colonize gradients of Fe(II) and oxygen, taking advantage of the available chemical energy. Vast communities of FeOM proliferate at deep sea hydrothermal vents, forming mineralized mats that range from centimeters to meters thick. Because these mats structure the environment for both FeOM and the entire microbial community, the Fe-oxidizers are acting as ecosystem engineers. What organisms are responsible for initiating these mats, and how does the physical structure and community composition develop as the mats mature? By connecting structure, function, and ecology, we can better interpret modern mat structures, as well as ancient fossilized mats. We have been studying Fe microbial mats at Loihi Seamount in Hawaii, a long-term study site that has become a model for Fe oxidation in marine hydrothermal systems. Recent improvements in ROV imaging systems allow us to see a great range of mat textures and colors, which may represent diverse habitats and/or different stages of mat development. With improved imaging and sampling techniques, we have been able to obtain discrete, intact samples of these delicate microbial mats. Previous bulk sampling methods showed that mats consist of a mixture of Fe-mineralized morphologies. Our analyses of intact mats show that mats are initiated by one type of structure-former (either a stalk-former like Mariprofundus ferrooxydans or a Zetaproteobacterial sheath-former). These microbes may be the vanguard organisms that stabilize chemical gradients in this dynamic environment, allowing colonization by other organisms (evidenced by branching tubes, fibrillar nests, and other morphologies). We will show evidence of the composition and development of these mats, and discuss parallels between these marine Fe mats and their freshwater counterparts, supporting the idea that FeOM engineer environments favorable for growth.

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 abstract.

Mechanical and transport properties of layer-by-layer electrospun composite proton exchange membranes for fuel cell applications.

PubMed

Mannarino, Matthew M; Liu, David S; Hammond, Paula T; Rutledge, Gregory C

2013-08-28

Composite membranes composed of highly conductive and selective layer-by-layer (LbL) films and electrospun fiber mats were fabricated and characterized for mechanical strength and electrochemical selectivity. The LbL component consists of a proton-conducting, methanol-blocking poly(diallyl dimethyl ammonium chloride)/sulfonated poly(2,6-dimethyl-1,4-phenylene oxide) (PDAC/sPPO) thin film. The electrospun fiber component consists of poly(trimethyl hexamethylene terephthalamide) (PA 6(3)T) fibers in a nonwoven mat of 60-90% porosity. The bare mats were annealed to improve their mechanical properties, which improvements are shown to be retained in the composite membranes. Spray LbL assembly was used as a means for the rapid formation of proton-conducting films that fill the void space throughout the porous electrospun matrix and create a fuel-blocking layer. Coated mats as thin as 15 μm were fabricated, and viable composite membranes with methanol permeabilities 20 times lower than Nafion and through-plane proton selectivity five and a half times greater than Nafion are demonstrated. The mechanical properties of the spray coated electrospun mats are shown to be superior to the LbL-only system and possess intrinsically greater dimensional stability and lower mechanical hysteresis than Nafion under hydrated conditions. The composite proton exchange membranes fabricated here were tested in an operational direct methanol fuel cell. The results show the potential for higher open circuit voltages (OCV) and comparable cell resistances when compared to fuel cells based on Nafion.

Vitamin-loaded electrospun cellulose acetate nanofiber mats as transdermal and dermal therapeutic agents of vitamin A acid and vitamin E.

PubMed

Taepaiboon, Pattama; Rungsardthong, Uracha; Supaphol, Pitt

2007-09-01

The present contribution reports the use of mats of electrospun cellulose acetate (CA; acetyl content=39.8%; Mw=30,000 Da) nanofibers as carriers for delivery of the model vitamins, all-trans retinoic acid or vitamin A acid (Retin-A) and alpha-tocopherol or vitamin E (Vit-E). The amounts of Vit-E and Retin-A loaded in the base CA solution [17% w/v in 2:1 v/v acetone/N,N-dimethylacetamide (DMAc)] were 5 and 0.5 wt% (based on the weight of CA), respectively. Cross-sectionally round and smooth fibers were obtained. The average diameters of these fibers ranged between 247 and 265 nm. The total immersion of the vitamin-loaded as-spun CA fiber mats in the acetate buffer solutions containing either 0.5 vol % Tween 80 or 0.5 vol % Tween 80 and 10 vol % methanol was used to arrive at the cumulative release of the vitamins from the fiber mat samples. The same was also conducted on the vitamin-loaded solution-cast CA films for comparison. In most cases, the vitamin-loaded as-spun fiber mats exhibited a gradual and monotonous increase in the cumulative release of the vitamins over the test periods (i.e., 24 h for Vit-E-loaded samples and 6 h for Retin-A-loaded ones), while the corresponding as-cast films exhibited a burst release of the vitamins.

Identification of cattle, buffaloes and rodents as reservoir animals of Leptospira in the District of Gampaha, Sri Lanka.

PubMed

Denipitiya, D T H; Chandrasekharan, N V; Abeyewickreme, W; Hartskeerl, R A; Hapugoda, M D

2017-03-23

Leptospirosis is an important emerging infectious disease in Sri Lanka. Rats are the most important reservoir of Leptospira but domestic and wild mammals may also act as important maintenance or accidental hosts. In Sri Lanka, knowledge of reservoir animals of leptospires is poor. The objective of this study was to identify potential reservoir animals of Leptospira in the District of Gampaha, Sri Lanka. Blood and kidney samples were collected from 38 rodents and mid-stream urine samples were randomly collected from 45 cattle and five buffaloes in the District of Gampaha. Kidney and urine samples were tested by real-time polymerase chain reaction (PCR) and serum samples were tested by the microscopic agglutination test (MAT). Of the 38 rodent kidney samples, 11% (4/38) were positive by real-time PCR. The prevalence of leptospiral carriage was 11% (3/26) and 8% (1/12) in female and male rodents, respectively. Three rodent serum samples were positive by MAT. Of the 50 cattle/buffalo urine samples tested, 10% (5/50) were positive by real-time PCR. The prevalence of leptospiral carriage was 9% (4/45) and 20% (1/5) in cattle and buffaloes, respectively. Results of PCR and MAT showed that Leptospira were present in a significant proportion of the rodents and farm animals tested in this study and suggest that these (semi-) domestic animals form an infection reservoir for Leptospira. Therefore, there is a potential zoonotic risk to public health, most notably to farmers in this area.

Biomarkers: d13C and d15N Distribution Tightly Coupled to Nutrient Dynamics and Viral Lysing in a Microbial Mat From Death Valley, California

NASA Astrophysics Data System (ADS)

Hewson, I.; Archer, R.; Mahaffey, C.; Scott, J.; Tsapin, A.

2002-12-01

Extrapolations into ancient biomes make many assumptions and inferences regarding life modes and environmental habitat. While definition of a stromatolite as an extinct microbial biome by petrographic analysis is promising, Life interacts with is environment, actively manipulating energy flow across chemical disequilibria gradients, harvesting energy crucial for physiological maintenance and reproduction. Such structuring of communities in turn, leaves specific chemical/isotopic imprints related to physiological processes of prokaryotic communities specific to each oxidation/redox horizon. We examine stable isotopic d13C signals (d13C and d15N) as potential biomarkers reflecting bacterial physiology and microbial community nutrient-energy dynamics. While isotopes may reveal ancient chemical structuring of microbial mats, we also turn to invoking viral lysing of bacterial hosts in nutrient cycling within modern extreme environments as well as ancient stromatic structures of early Earth. Our records of d13C indicate extreme enrichment(-12%) for Corg in our extant mat due to CO2 limitation across a hypersaline diffusive barrier at the mat's surface. d15N is lowest at the mat's surface (indicating N2- fixation) where nitrogen- fixing cyanobacteria Microcoleus sp. are present . Viruses are extremely abundant in the microbial mat, exceeding bacterial abundances by a factor of ten. The ratio of viruses to bacteria was very high (VBR = 39 ñ 10) compared with abundances in marine sediments. Distribution of viruses closely follows distribution of bacteria, suggesting bacteria as primary hosts. The ratio of viruses to bacteria is inversely correlated to the concentration of organic C suggesting virus abundance is responsive to host substrate availability. High ratios of viruses to bacteria in mid-mat horizons (2.5 - 3.7 cm) above increasing levels of d13C in deeper horizons, coupled with a lack of increase in bacteria, suggests that viral lysis contributes to significant downward organic C (polysaccaride exudates) transport within the mat. Subsequent accumulation of d13C as well as heavier d15N in deeper sediment(denitrification)horizons elucidates tight nutrient coupling between evaporite substrate, nitrogen fixing primary producers and downcore zones of active denitrification and sulphate reduction. Discrepencies between d13C of ancient stromatolites (in line with C-3 photosynthetic pathways) and modern analogues (Badwater, CA) suggest a migration of microbial mats towards more extreme environments through time. A methodology for isotopically testing environmental and physiological responses in the geological record is presented here.

Presence of antigen and antibodies in serum and genital discharges of cows from dairy herds naturally infected with Leptospira interrogans serovar hardjo.

PubMed

Dhaliwal, G S; Murray, R D; Dobson, H; Montgomery, J; Ellis, W A

1996-03-01

Samples of cervico-vaginal mucus from 163 bulling cows (group 1) and post calving discharges from 59 newly calved cows (group 2) in five dairy herds naturally infected with Leptospira interrogans serovar hardjo were examined for the presence of antigen and IgG and IgA antibodies by using two ELISA systems which were protein or carbohydrate based. Corresponding serum samples were examined for systemic immune responses by using a microscopic agglutination test (MAT) and IgG-ELISA tests. Antigen was detected by direct immunofluorescence in six of the 163 samples of cervico-vaginal mucus. Both IgG and IgA antibodies were detected by ELISA in the genital discharges with a prevalence much higher than that obtained by the MAT but lower than that observed with the serum IgG-ELISA. Combining both groups, none of the MAT-positive cattle was negative by serum-ELISA. By using the protein or carbohydrate fraction serum IgG-ELISA assays, respectively, 29 or 41 per cent of the MAT-negative cows were positive at a titre of at least 1:40. Similarly, eight or 23 samples (10 or 27 per cent) had titres of at least 1:20 in the genital discharge ELISA for IgG and IgA antibodies, respectively. The serum IgG-ELISA was the most efficient in detecting hardjo antibodies, but in group 2 the IgG- and IgA-ELISA of the post calving discharge proved to be equally effective.

Microbialite Biosignature Analysis by Mesoscale X-ray Fluorescence (μXRF) Mapping

NASA Astrophysics Data System (ADS)

Tice, Michael M.; Quezergue, Kimbra; Pope, Michael C.

2017-11-01

As part of its biosignature detection package, the Mars 2020 rover will carry PIXL, the Planetary Instrument for X-ray Lithochemistry, a spatially resolved X-ray fluorescence (μXRF) spectrometer. Understanding the types of biosignatures detectable by μXRF and the rock types μXRF is most effective at analyzing is therefore an important goal in preparation for in situ Mars 2020 science and sample selection. We tested mesoscale chemical mapping for biosignature interpretation in microbialites. In particular, we used μXRF to identify spatial distributions and associations between various elements ("fluorescence microfacies") to infer the physical, biological, and chemical processes that produced the observed compositional distributions. As a test case, elemental distributions from μXRF scans of stromatolites from the Mesoarchean Nsuze Group (2.98 Ga) were analyzed. We included five fluorescence microfacies: laminated dolostone, laminated chert, clotted dolostone and chert, stromatolite clast breccia, and cavity fill. Laminated dolostone was formed primarily by microbial mats that trapped and bound loose sediment and likely precipitated carbonate mud at a shallow depth below the mat surface. Laminated chert was produced by the secondary silicification of microbial mats. Clotted dolostone and chert grew as cauliform, cryptically laminated mounds similar to younger thrombolites and was likely formed by a combination of mat growth and patchy precipitation of early-formed carbonate. Stromatolite clast breccias formed as lag deposits filling erosional scours and interstromatolite spaces. Cavities were filled by microquartz, Mn-rich dolomite, and partially dolomitized calcite. Overall, we concluded that μXRF is effective for inferring genetic processes and identifying biosignatures in compositionally heterogeneous rocks.

Evaluating the capacity of plant DNA barcodes to discriminate species of cotton (Gossypium: Malvaceae).

PubMed

Ashfaq, Muhammad; Asif, Muhammad; Anjum, Zahid Iqbal; Zafar, Yusuf

2013-07-01

Although two plastid regions have been adopted as the standard markers for plant DNA barcoding, their limited resolution has provoked the consideration of other gene regions, especially in taxonomically diverse genera. The genus Gossypium (cotton) includes eight diploid genome groups (A-G, and K) and five allotetraploid species which are difficult to discriminate morphologically. In this study, we tested the effectiveness of three widely used markers (matK, rbcL, and ITS2) in the discrimination of 20 diploid and five tetraploid species of cotton. Sequences were analysed locus-wise and in combinations to determine the most effective strategy for species identification. Sequence recovery was high, ranging from 92% to 100% with mean pairwise interspecific distance highest for ITS2 (3.68%) and lowest for rbcL (0.43%). At a 0.5% threshold, the combination of matK+ITS2 produced the greatest number of species clusters. Based on 'best match' analysis, the combination of matK+ITS2 was best, while based on 'all species barcodes' analysis, ITS2 gave the highest percentage of correct species identifications (98.93%). The combination of sequences for all three markers produced the best resolved tree. The disparity index test based on matK+rbcL+ITS2 was significant (P < 0.05) for a higher number of species pairs than the individual gene sequences. Although all three barcodes separated the species with respect to their genome type, no single combination of barcodes could differentiate all the Gossypium species, and tetraploid species were particularly difficult. © 2013 John Wiley & Sons Ltd.

Inversion of the chromosomal region between two mating type loci switches the mating type in Hansenula polymorpha.

PubMed

Maekawa, Hiromi; Kaneko, Yoshinobu

2014-11-01

Yeast mating type is determined by the genotype at the mating type locus (MAT). In homothallic (self-fertile) Saccharomycotina such as Saccharomyces cerevisiae and Kluveromyces lactis, high-efficiency switching between a and α mating types enables mating. Two silent mating type cassettes, in addition to an active MAT locus, are essential components of the mating type switching mechanism. In this study, we investigated the structure and functions of mating type genes in H. polymorpha (also designated as Ogataea polymorpha). The H. polymorpha genome was found to harbor two MAT loci, MAT1 and MAT2, that are ∼18 kb apart on the same chromosome. MAT1-encoded α1 specifies α cell identity, whereas none of the mating type genes were required for a identity and mating. MAT1-encoded α2 and MAT2-encoded a1 were, however, essential for meiosis. When present in the location next to SLA2 and SUI1 genes, MAT1 or MAT2 was transcriptionally active, while the other was repressed. An inversion of the MAT intervening region was induced by nutrient limitation, resulting in the swapping of the chromosomal locations of two MAT loci, and hence switching of mating type identity. Inversion-deficient mutants exhibited severe defects only in mating with each other, suggesting that this inversion is the mechanism of mating type switching and homothallism. This chromosomal inversion-based mechanism represents a novel form of mating type switching that requires only two MAT loci.

Technology for Ice Rinks

NASA Technical Reports Server (NTRS)

1983-01-01

Ron Urban's International Ice Shows set up portable ice rinks for touring troupes performing on temporary rinks at amusement parks, sports arenas, dinner theaters, shopping malls and civic centers. Key to enhanced rink portability, fast freezing and maintaining ice consistency is a mat of flexible tubing called ICEMAT, an offshoot of a solar heating system developed by Calmac, Mfg. under contract with Marshall.

Superconductive Microwave Single-Flux-Quantum Digital Circuits and Corresponding Opto-Electronic Interfaces: On-Going Studies and First Experimental Results

DTIC Science & Technology

2005-07-13

UHLMANN University of Technology Ilmenau– PO Box 105565 – D-98684 Ilmenau - Germany RESUME : Les circuits numériques supraconducteurs micro-ondes...circuits RSFQ. Ce banc de mesure comporte deux types d’interfaces opto-RSFQ, basées sur des matériaux semiconducteurs et supraconducteurs , respectivement

Clinical, serological and echocardiographic examination of healthy field dogs before and after vaccination with a commercial tetravalent leptospirosis vaccine.

PubMed

Spiri, Andrea M; Rodriguez-Campos, Sabrina; Matos, José M; Glaus, Tony M; Riond, Barbara; Reusch, Claudia E; Hofmann-Lehmann, Regina; Willi, Barbara

2017-05-25

Leptospirosis is a re-emerging bacterial zoonosis caused by spirochetes of the genus Leptospira. Severe disease has been reported in dogs in Europe despite vaccination with bivalent Leptospira vaccines. Recently, a tetravalent canine Leptospira vaccine (Nobivac® L4) was licenced in Europe. The goal of this study was to investigate clinical signs, microscopic agglutination test (MAT) titres, haematology, blood biochemistry, cardiac (c) Troponin I levels and echocardiography before and after vaccination with this tetravalent vaccine. Forty-eight healthy dogs were prospectively enrolled and vaccinated twice, 3-4 weeks apart (T0 and T1). Before vaccination (T0) and 16-31 days after the second vaccination (T2), MAT (n = 48), haematology (n = 48), blood biochemistry (n = 36) and cTroponin I measurements (n = 29) were performed, and MAT was repeated 347-413 days after the second vaccination (T3, n = 44). Echocardiography was performed before the first and second vaccination (T0 and T1, n = 24). Mild and transient clinical signs within 5 days following the first and second vaccination occurred in 23% and 10% of the dogs, respectively. Before the first vaccination (T0), all dogs showed negative MAT titres for the tested serovars except for Canicola (50% with titres 100-400). At T2, positive MAT titres to the serovars Canicola (100%), Australis (89%), Grippotyphosa (86%), Bratislava (60%), Autumnalis (58%), Copenhageni (42%), Pomona (12%), Pyrogenes (8%) and Icterohaemorrhagiae (2%) were found. Median to high titres (≥ 400) were most common to the serovar Canicola (92%) and less common to the serovars Australis (41%), Grippotyphosa (21%), Bratislava (12%), Autumnalis (4%), Pyrogenes (4%) and Pomona (2%). At T3, positive MAT titres (titre range: 100-400) were found in 2-18% of the dogs to serovars of the vaccine serogroups and in 2-18% of the dogs to the non-vaccine serovars Pomona, Autumnalis, Pyrogenes and Ballum. Haematology, blood biochemistry, cTroponin I levels and echocardiography results did not change significantly following vaccination. Clinical signs following vaccination with Nobivac® L4 were transient and mild in all cases. Seroconversion differed considerably among individual dogs and among the vaccine serogroups.

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 in the submerged hypersaline mats. Developing mats in both the subtidal and intertidal locations had delta (15)N(sub organic) values very near those of the established mats. Further work is necessary in order to determine the importance of other transformations of nitrogen on the delta (15)N(sub organic) signature of the mats.

Calcium-dependent protein kinase CPK28 targets the methionine adenosyltransferases for degradation by the 26S proteasome and affects ethylene biosynthesis and lignin deposition in Arabidopsis.

PubMed

Jin, Yu; Ye, Nenghui; Zhu, Fuyuan; Li, Haoxuan; Wang, Juan; Jiang, Liwen; Zhang, Jianhua

2017-04-01

S-adenosylmethionine (AdoMet) is synthesized by methionine adenosyltransferase (MAT), and plays an essential role in ethylene biosynthesis and other methylation reactions. Despite increasing knowledge of MAT regulation at transcriptional levels, how MAT is post-translationally regulated remains unknown in plant cells. Phosphorylation is an important post-translational modification for regulating the activity of enzymes, protein function and signaling transduction. Using molecular and biochemical approaches, we have identified the phosphorylation of MAT proteins by calcium-dependent protein kinase (CPK28). Phenotypically, both MAT2-overexpressing transgenic plants and cpk28 mutants display short hypocotyls and ectopic lignifications. Their shortened hypocotyl phenotypes are caused by ethylene overproduction and rescued by ethylene biosynthesis inhibitor aminoethoxyvinylglycine treatment. Genetic evidence reveals that MAT2 mutation restores the phenotype of ectopic lignification in CPK28-deficient plants. We find that total MAT proteins and AdoMet are increased in cpk28 mutants, but decreased in CPK28-overexpressing seedlings. We also find that MATs in OE::CPK28 are degraded through the 26S proteasome pathway. Our work suggests that CPK28 targets MATs (MAT1, MAT2 and MAT3) for degradation by the 26S proteasome pathway, and thus affects ethylene biosynthesis and lignin deposition in Arabidopsis. © 2017 The Authors The Plant Journal © 2017 John Wiley & Sons Ltd.

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.

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.

Toxoplasma gondii infections in chickens - performance of various antibody detection techniques in serum and meat juice relative to bioassay and DNA detection methods.

PubMed

Schares, G; Koethe, M; Bangoura, B; Geuthner, A-C; Randau, F; Ludewig, M; Maksimov, P; Sens, M; Bärwald, A; Conraths, F J; Villena, I; Aubert, D; Opsteegh, M; Van der Giessen, J

2018-05-19

Chickens, especially if free-range, are frequently exposed to Toxoplasma gondii, and may represent an important reservoir for T. gondii. Poultry products may pose a risk to humans, when consumed undercooked. In addition, chickens are regarded as sensitive indicators for environmental contamination with T. gondii oocysts and have been used as sentinels. The aim of the present study was to determine the suitability of commonly used antibody detection methods, i.e. the modified agglutination test (MAT), IFAT and ELISA to detect T. gondii-infected chickens. Samples of experimentally and naturally infected chickens were used. The infection state of all chickens was determined by Magnetic-Capture (MC-) real-time PCR (RT PCR). Naturally exposed chickens were additionally examined by mouse bioassay and conventional RT PCR on acidic pepsin digests (PD-RT PCR). Blood serum and meat juice of various sources were tested for antibodies to T. gondii. In naturally infected chickens, there was substantial agreement between the mouse bioassay and MC-RT PCR or the mouse bioassay and conventional PD-RT PCR. PD-RT PCR was slightly more sensitive than MC-RT PCR, as all (26/26) bioassay-positive chickens also tested positive in at least one of the tissues tested (heart, drumstick). By MC-RT PCR, 92.3% (24/26) of the naturally infected bioassay-positive chickens were positive. The diagnostic sensitivity of MC-RT PCR was clearly related to the organ examined. Based on a quantitative assessment of the MC-RT PCR results in experimentally infected chickens, brain and heart tissues harbored an at least 100 times higher parasite concentration than breast, thigh or drumstick musculature. In naturally infected chickens, only three out of 24 birds, which were MC-RT PCR-positive in heart samples, also tested positive in drumstick musculature. Under experimental conditions, the agreement between MC-RT PCR and the serological techniques revealed 100% diagnostic sensitivity and specificity. Under field conditions, examinations of sera by ELISA, IFAT and MAT showed good performance in identifying chickens that were positive in either a mouse bioassay, MC-RT PCR, or PD-RT PCR as illustrated by diagnostic sensitivities of 87.5%, 87.5% and 65.2%, respectively, and diagnostic specificities of 86.2%, 82.8% and 100%, respectively. The examination of meat juice samples from breast, drumstick or heart musculature revealed similar or even better results in the ELISA. The results in the MAT with meat juice from breast musculature were less consistent than those of ELISA and IFAT because a number of negative chickens tested false-positive in the MAT. The MAT performed similar to ELISA and IFAT when applied to test meat juice samples collected from heart, thigh or drumstick musculature. Copyright © 2018 Australian Society for Parasitology. Published by Elsevier Ltd. All rights reserved.

Leptospirosis outbreak following severe flooding: a rapid assessment and mass prophylaxis campaign; Guyana, January-February 2005.

PubMed

Dechet, Amy M; Parsons, Michele; Rambaran, Madan; Mohamed-Rambaran, Pheona; Florendo-Cumbermack, Anita; Persaud, Shamdeo; Baboolal, Shirematee; Ari, Mary D; Shadomy, Sean V; Zaki, Sherif R; Paddock, Christopher D; Clark, Thomas A; Harris, Lazenia; Lyon, Douglas; Mintz, Eric D

2012-01-01

Leptospirosis is a zoonosis usually transmitted through contact with water or soil contaminated with urine from infected animals. Severe flooding can put individuals at greater risk for contracting leptospirosis in endemic areas. Rapid testing for the disease and large-scale interventions are necessary to identify and control infection. We describe a leptospirosis outbreak following severe flooding and a mass chemoprophylaxis campaign in Guyana. From January-March 2005, we collected data on suspected leptospirosis hospitalizations and deaths. Laboratory testing included anti-leptospiral dot enzyme immunoassay (DST), immunohistochemistry (IHC) staining, and microscopic agglutination testing (MAT). DST testing was conducted for 105 (44%) of 236 patients; 52 (50%) tested positive. Four (57%) paired serum samples tested by MAT were confirmed leptospirosis. Of 34 total deaths attributed to leptospirosis, postmortem samples from 10 (83%) of 12 patients were positive by IHC. Of 201 patients interviewed, 89% reported direct contact with flood waters. A 3-week doxycycline chemoprophylaxis campaign reached over 280,000 people. A confirmed leptospirosis outbreak in Guyana occurred after severe flooding, resulting in a massive chemoprophylaxis campaign to try to limit morbidity and mortality.

Assessing biological and chemical signatures related to nutrient removal by floating islands in stormwater mesocosms.

PubMed

Chang, Ni-Bin; Islam, Kamrul; Marimon, Zachary; Wanielista, Martin P

2012-07-01

Aquatic floating plants on BioHaven mats were tested for their potential use as a Best Management Practice to be incorporated within existing stormwater detention ponds. Plants were analyzed for their capability to remove nutrient-pollution in parallel with the study of ecological dynamics. Experiments were carried out in cylindrical mesocosms of 5 m diameter and 1.2 m height, above-ground pools with a water volume of 14 m(3). The design parameters tested were for 5% and 10% vegetated floating island coverage of the mesocosm, both with and without shoreline plants called littoral zone. This littoral shelf was 0.5 m thick, graded at a downward slope of 1:5 toward the center using loamy soil with low organic matter content, excavated from below turf grass. Endemic plant species were chosen for the experimental location in central Florida based on a wetland identification manual by the Florida Department of Environmental Protection to ensure the study was not compromised by unique climate requirements of the plants. Nutrient and aquatic chemical conditions such as pH, dissolved oxygen, temperature, turbidity, and chlorophyll a were monitored to understand their relationships to the general wetland ecosystem. Real-time polymerase chain reaction analysis identified the microbial activity near the rhizospheric zone. Logistical placement considerations were made using spatial sampling across the horizontal plane of the mesocosms, beneath and around the root zone, to determine if nutrients tend to aggregate around the floating island. This study concluded that the application of floating islands as a stormwater technology can remove nutrients through plant uptake and biological activity. The most cost-effective size in the outdoor mesocosms was 5% surface area coverage of the mat. Copyright © 2012 Elsevier Ltd. All rights reserved.

Leptospirosis in domestic animals in France: serological results from 1988 to 2007.

PubMed

André-Fontaine, G

2016-12-01

Leptospirosis is a common infection in domestic animals. The microscopic agglutination test (MAT) is used for serological diagnosis. From 1988 to 2007, the Leptospira Medical and Molecular Bacteriology Laboratory at the Nantes National College of Veterinary Medicine, Food Science and Engineering used the MAT to test serum samples from more than 40,000 cattle, 40,000 pigs, 20,000 horses and 9,500 dogs. Five Leptospira serogroups were prominent, with specific variations within the four animal species: Icterohaemorrhagiae, Australis, Sejroë, Grippotyphosa and Autumnalis. The prevalence and incidence of each serogroup varied for each species over the 20-year period: some serogroups were emergent during some years but disappeared later. This study reports the complex epidemiological features of leptospirosis. © OIE (World Organisation for Animal Health), 2016.

Simulating the Response of a Composite Honeycomb Energy Absorber. Part 1; Dynamic Crushing of Components and Multi-Terrain Impacts

NASA Technical Reports Server (NTRS)

Jackson, Karen E.; Fasanella, Edwin L.; Polanco, Michael A.

2012-01-01

This paper describes the experimental and analytical evaluation of an externally deployable composite honeycomb structure that is designed to attenuate impact energy during helicopter crashes. The concept, designated the Deployable Energy Absorber (DEA), utilizes an expandable Kevlar (Registered Trademark) honeycomb to dissipate kinetic energy through crushing. The DEA incorporates a unique flexible hinge design that allows the honeycomb to be packaged and stowed until needed for deployment. Experimental evaluation of the DEA included dynamic crush tests of multi-cell components and vertical drop tests of a composite fuselage section, retrofitted with DEA blocks, onto multi-terrain. Finite element models of the test articles were developed and simulations were performed using the transient dynamic code, LSDYNA (Registered Trademark). In each simulation, the DEA was represented using shell elements assigned two different material properties: Mat 24, an isotropic piecewise linear plasticity model, and Mat 58, a continuum damage mechanics model used to represent laminated composite fabrics. DEA model development and test-analysis comparisons are presented.

Serodiagnosis of bovine leptospirosis by IgG-enzyme-linked immunosorbent assay and latex agglutination test.

PubMed

Senthilkumar, T M A; Subathra, M; Ramadass, P; Ramaswamy, V

2010-02-01

The efficacy of a recombinant leptospiral outer membrane protein LipL41 as an antigen for conducting IgG-Enzyme linked immunosorbent assay (ELISA) and latex agglutination test (LAT) for serodiagnosis of bovine leptospirosis was evaluated. The recombinant LipL41 antigen developed and used for detecting the antibodies was specific in detection of the pathogenic serovars of Leptospira, as the expression of the LipL41 antigen is restricted only to pathogenic leptospires. A total of 430 bovine serum samples were subjected to IgG-ELISA and LAT, and the sensitivity and specificity were assessed in comparison with microscopic agglutination test (MAT). The sensitivity and specificity of IgG-ELISA and LAT were 86.84% and 93.16%, and 95.42% and 98.33% respectively. Both the tests are found to be sensitive, specific and concurred with the standard MAT. The study concluded that the rLipL41 protein could be used as a potential diagnostic antigen in different assay formats for bovine leptospirosis.

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

Universal Plant DNA Barcode Loci May Not Work in Complex Groups: A Case Study with Indian Berberis Species

PubMed Central

Roy, Sribash; Tyagi, Antariksh; Shukla, Virendra; Kumar, Anil; Singh, Uma M.; Chaudhary, Lal Babu; Datt, Bhaskar; Bag, Sumit K.; Singh, Pradhyumna K.; Nair, Narayanan K.; Husain, Tariq; Tuli, Rakesh

2010-01-01

Background The concept of DNA barcoding for species identification has gained considerable momentum in animals because of fairly successful species identification using cytochrome oxidase I (COI). In plants, matK and rbcL have been proposed as standard barcodes. However, barcoding in complex genera is a challenging task. Methodology and Principal Findings We investigated the species discriminatory power of four reportedly most promising plant DNA barcoding loci (one from nuclear genome- ITS, and three from plastid genome- trnH-psbA, rbcL and matK) in species of Indian Berberis L. (Berberidaceae) and two other genera, Ficus L. (Moraceae) and Gossypium L. (Malvaceae). Berberis species were delineated using morphological characters. These characters resulted in a well resolved species tree. Applying both nucleotide distance and nucleotide character-based approaches, we found that none of the loci, either singly or in combinations, could discriminate the species of Berberis. ITS resolved all the tested species of Ficus and Gossypium and trnH-psbA resolved 82% of the tested species in Ficus. The highly regarded matK and rbcL could not resolve all the species. Finally, we employed amplified fragment length polymorphism test in species of Berberis to determine their relationships. Using ten primer pair combinations in AFLP, the data demonstrated incomplete species resolution. Further, AFLP analysis showed that there was a tendency of the Berberis accessions to cluster according to their geographic origin rather than species affiliation. Conclusions/Significance We reconfirm the earlier reports that the concept of universal barcode in plants may not work in a number of genera. Our results also suggest that the matK and rbcL, recommended as universal barcode loci for plants, may not work in all the genera of land plants. Morphological, geographical and molecular data analyses of Indian species of Berberis suggest probable reticulate evolution and thus barcode markers may not work in this case. PMID:21060687

Serodiagnosis of Equine Leptospirosis by Enzyme-Linked Immunosorbent Assay Using Four Recombinant Protein Markers

PubMed Central

Ye, Cuilian; Yan, Weiwei; McDonough, Patrick L.; McDonough, Sean P.; Mohamed, Hussni; Divers, Thomas J.; Chang, Yung-Fu

2014-01-01

Leptospirosis, caused by Leptospira spp., is one of the most common zoonotic diseases in the world. We tested four recombinant proteins of Leptospira interrogans, namely, rLipL21, rLoa22, rLipL32, and rLigACon4-8, to evaluate their potential for use as antigens for the diagnosis of equine leptospirosis. We employed equine sera (n = 130) that were microscopic agglutination test (MAT) negative and sera (n = 176) that were MAT positive for the 5 serovars that most commonly cause equine leptospirosis. The sensitivity and specificity of ELISA compared to MAT were 82.39% and 86.15%, respectively, for LigACon4-8, 77.84% and 92.31%, respectively, for Loa22, 77.84% and 86.15%, respectively, for LipL32, and 84.66% and 83.85%, respectively, for LipL21. When one of the two antigens was test positive, the sensitivity and specificity of ELISA were 93.75% and 78.46%, respectively, for rLigACon4-8 and LipL32, 93.18% and 76.15%, respectively, for rLigACon4-8 and LipL21, 89.77% and 80.77%, respectively, for rLigACon4-8 and Loa22, 91.48% and 78.46%, respectively, for LipL21 and Loa22, 93.75% and 76.92%, respectively, for LipL21 and LipL32, and 90.34% and 80.77%, respectively, for Loa22 and LipL32. In conclusion, we have developed an indirect ELISA utilizing rLigACon4-8, rLoa22, rLipL32, and rLipL21 as diagnostic antigens for equine leptospirosis. The use of four antigens in the ELISA was found to be sensitive and specific, the assay was easy to perform, and the results concurred with the results of the standard Leptospira MAT. PMID:24451330

State-wide hospital clinical laboratory plan for measuring cholinesterase activity for individuals suspected of exposure to nerve agent chemical weapons.

PubMed

Wu, Alan H B; Smith, Andrew; McComb, Robert; Bowers, George N; Makowski, Gregory S; McKay, Charles A; Vena, Jason; McDonagh, John; Hopfer, Sidney; Sena, Salvatore F; Malkus, Herbert; Forte, Elaine; Kelly, Katherine

2008-02-01

Hospital laboratories currently lack the capacity to provide emergency determination of cholinesterase activity. We have developed a hospital-based 3-tiered system to test plasma for butyrylcholinesterase (BChE) activity and whole blood for red cell acetylcholinesterase (AChE) activity using available technology and personnel. Interagency communications, toxidrome definition, and patient triage will be coordinated by the Connecticut Department of Public Health and the Poison Control Center. Initial BChE data documents good precision between institutions (coefficient of variation < 8%). Laboratory testing of plasma or blood for cholinesterase activity is important in the management of nerve agent exposure and in ruling out disease in those with non-specific symptoms in the setting of a terrorist attack or accidental exposure. Rapid availability of strong hospital-based analytic support in a smoothly functioning network of clinical, public health, and laboratory services will facilitate overall regional response to chemical terrorism or large scale HazMat events.

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.

Extruder Operator (plastics mat.) 6-51.468--Technical Report on Standardization of the General Aptitude Test Battery.

ERIC Educational Resources Information Center

Manpower Administration (DOL), Washington, DC. U.S. Training and Employment Service.

The United States Training and Employment Service General Aptitude Test Battery (GATB), first published in 1947, has been included in a continuing program of research to validate the tests against success in many different occupations. The GATB consists of 12 tests which measure nine aptitudes: General Learning Ability; Verbal Aptitude; Numerical…

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 communities and that these mats contribute directly to the removal of hydrocarbons from oil field wastewaters.

Evidence for Sexual Reproduction: Identification, Frequency, and Spatial Distribution of Venturia effusa (Pecan Scab) Mating Type Idiomorphs.

PubMed

Young, Carolyn A; Bock, Clive H; Charlton, Nikki D; Mattupalli, Chakradhar; Krom, Nick; Bowen, Joanna K; Templeton, Matthew; Plummer, Kim M; Wood, Bruce W

2018-05-10

Venturia effusa (syn. Fusicladium effusum), causal agent of pecan scab, is the most prevalent pathogen of pecan (Carya illinoinensis), causing severe yield losses in the southeastern United States. V. effusa is currently known only by its asexual (conidial) stage. However, the degree and distribution of genetic diversity observed within and among populations of V. effusa are typical of a sexually reproducing fungal pathogen, and comparable with other dothideomycetes with a known sexual stage, including the closely related apple scab pathogen, V. inaequalis. Using the mating type (MAT) idiomorphs from V. inaequalis, we identified a single MAT gene, MAT1-1-1, in a draft genome of V. effusa. The MAT1-1-1 locus is flanked by two conserved genes encoding a DNA lyase (APN2) and a hypothetical protein. The MAT locus spanning the flanking genes was amplified and sequenced from a subset of 14 isolates, of which 7 contained MAT1-1-1 and the remaining samples contained MAT1-2-1. A multiplex polymerase chain reaction screen was developed to amplify MAT1-1-1, MAT1-2-1, and a conserved reference gene encoding β-tubulin, and used to screen 784 monoconidial isolates of V. effusa collected from 11 populations of pecan across the southeastern United States. A hierarchical sampling protocol representing region, orchard, and tree allowed for analysis of MAT structure at different spatial scales. Analysis of this collection revealed the frequency of the MAT idiomorphs is in a 1:1 equilibrium of MAT1-1:MAT1-2. The apparent equilibrium of the MAT idiomorphs provides impetus for a renewed effort to search for the sexual stage of V. effusa. [Formula: see text] Copyright © 2018 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license .

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.

Evaluation of the recombinant LipL32 in enzyme-linked immunosorbent assay for the serodiagnosis of bovine leptospirosis.

PubMed

Bomfim, Maria Rosa Quaresma; Ko, Albert; Koury, Matilde Cota

2005-08-10

The recombinant leptospiral protein LipL32 was evaluated for use in the diagnosis of bovine leptospirosis by enzyme-linked immunosorbent assay (rLipL32 IgG ELISA). The microscopic agglutination test (MAT) of 150 serum samples from cattle suspected of leptospirosis showed that 125 (83.3%) samples had positive reciprocal agglutination titres, which ranged from 100 to 1600. The highest titres were observed for the serovars Hardjoprajitno and Bratislava. In the rLipL32 IgG ELISA, 83.3% of the samples were positive. The sensitivity of IgG ELISA for 125 bovine sera, which had MAT titres of greater than or equal to 100, was 100%. ELISA showed a specificity of 100% with 58 bovine sera, which were negative at a 1:50 dilution in the MAT for Leptospira interrogans serovars. When analytical specificity of the IgG ELISA was evaluted using 60 bovine serum samples from animals showing serum antibodies to other pathogens that cause abortion in cattle, such as Babesia sp., Anaplasma sp. and Brucella sp. and no cross-reaction was observed. The recombinant LipL32 IgG ELISA can be an alternative to the MAT for diagnosis of leptospiral infection in cattle.

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

Alignment of Irregular Grains by Mechanical Torques

NASA Astrophysics Data System (ADS)

Hoang, Thiem; Cho, Jungyeon; Lazarian, A.

2018-01-01

We study the alignment of irregular dust grains by mechanical torques due to the drift of grains through the ambient gas. We first calculate mechanical alignment torques (MATs) resulting from specular reflection of gas atoms for seven irregular shapes: one shape of mirror symmetry, three highly irregular shapes (HIS), and three weakly irregular shapes (WIS). We find that the grain with mirror symmetry experiences negligible MATs due to its mirror-symmetry geometry. Three HIS can produce strong MATs, which exhibit some generic properties as radiative torques (RATs), while three WIS produce less efficient MATs. We then study grain alignment by MATs for the different angles between the drift velocity and the ambient magnetic field, for paramagnetic and superparamagnetic grains assuming efficient internal relaxation. We find that for HIS grains, MATs can align subsonically drifting grains in the same way as RATs, with low-J and high-J attractors. For supersonic drift, MATs can align grains with low-J and high-J attractors, analogous to RAT alignment by anisotropic radiation. We also show that the joint action of MATs and magnetic torques in grains with iron inclusions can lead to perfect MAT alignment. Our results point out the potential importance of MAT alignment for HIS grains predicted by the analytical model of Lazarian & Hoang, although more theoretical and observational studies are required due to uncertainty in the shape of interstellar grains. We outline astrophysical environments where MAT alignment is potentially important.

Honey/Chitosan Nanofiber Wound Dressing Enriched with Allium sativum and Cleome droserifolia: Enhanced Antimicrobial and Wound Healing Activity.

PubMed

Sarhan, Wessam A; Azzazy, Hassan M E; El-Sherbiny, Ibrahim M

2016-03-01

Two natural extracts were loaded within fabricated honey, poly(vinyl alcohol), chitosan nanofibers (HPCS) to develop biocompatible antimicrobial nanofibrous wound dressing. The dried aqueous extract of Cleome droserifolia (CE) and Allium sativum aqueous extract (AE) and their combination were loaded within the HPCS nanofibers in the HPCS-CE, HPCS-AE, and HPCS-AE/CE nanofiber mats, respectively. It was observed that the addition of AE resulted in the least fiber diameter (145 nm), whereas the addition of the AE and CE combination resulted in the least swelling ability and the highest weight loss. In vitro antibacterial testing against Staphylococcus aureus, Escherichia coli, Methicillin-resistant S. aureus (MRSA), and multidrug-resistant Pseudomonas aeruginosa was performed in comparison with the commercial dressing AquacelAg and revealed that the HPCS-AE and HPCS-AE/CE nanofiber mats allowed complete inhibition of S. aureus and the HPCS-AE/CE exhibited mild antibacterial activity against MRSA. A preliminary in vivo study revealed that the developed nanofiber mats enhanced the wound healing process as compared to the untreated control as proved by the enhanced wound closure rates in mice and by the histological examination of the wounds. Moreover, comparison with the commercial dressing Aquacel Ag, the HPCS, and HPCS-AE/CE demonstrated similar effects on the wound healing process, whereas the HPCS/AE allowed an enhanced wound closure rate. Cell culture studies proved the biocompatibility of the developed nanofiber mats in comparison with the commercial Aquacel Ag, which exhibited noticeable cytotoxicity. The developed natural nanofiber mats hold potential as promising biocompatible antibacterial wound dressing.

My Attitudes toward Science (MATS): The Development of a Multidimensional Instrument Measuring Students' Science Attitudes

ERIC Educational Resources Information Center

Hillman, Susan J.; Zeeman, Stephan I.; Tilburg, Charles E.; List, Henrietta E.

2016-01-01

The number of students in the United States choosing science, technology, engineering or mathematics careers is declining at a time when demand for these occupations is rapidly increasing. Numerous efforts have been undertaken to reverse this trend, yet results are uncertain. One's attitude is key to many choices one makes, and this includes, for…

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.

Lignin-based active anode materials synthesized from low-cost renewable resources

DOEpatents

Rios, Orlando; Tenhaeff, Wyatt Evan; Daniel, Claus; Dudney, Nancy Johnston; Johs, Alexander; Nunnery, Grady Alexander; Baker, Frederick Stanley

2016-06-07

A method of making an anode includes the steps of providing fibers from a carbonaceous precursor, the carbon fibers having a glass transition temperature T.sub.g. In one aspect the carbonaceous precursor is lignin. The carbonaceous fibers are placed into a layered fiber mat. The fiber mat is fused by heating the fiber mat in the presence of oxygen to above the T.sub.g but no more than 20% above the T.sub.g to fuse fibers together at fiber to fiber contact points and without melting the bulk fiber mat to create a fused fiber mat through oxidative stabilization. The fused fiber mat is carbonized by heating the fused fiber mat to at least 650.degree. C. under an inert atmosphere to create a carbonized fused fiber mat. A battery anode formed from carbonaceous precursor fibers is also disclosed.

Organic geochemical studies of modern microbial mats from Shark Bay: Part I: Influence of depth and salinity on lipid biomarkers and their isotopic signatures.

PubMed

Pagès, A; Grice, K; Ertefai, T; Skrzypek, G; Jahnert, R; Greenwood, P

2014-09-01

The present study investigated the influence of abiotic conditions on microbial mat communities from Shark Bay, a World Heritage area well known for a diverse range of extant mats presenting structural similarities with ancient stromatolites. The distributions and stable carbon isotopic values of lipid biomarkers [aliphatic hydrocarbons and polar lipid fatty acids (PLFAs)] and bulk carbon and nitrogen isotope values of biomass were analysed in four different types of mats along a tidal flat gradient to characterize the microbial communities and systematically investigate the relationship of the above parameters with water depth. Cyanobacteria were dominant in all mats, as demonstrated by the presence of diagnostic hydrocarbons (e.g. n-C17 and n-C17:1). Several subtle but important differences in lipid composition across the littoral gradient were, however, evident. For instance, the shallower mats contained a higher diatom contribution, concordant with previous mat studies from other locations (e.g. Antarctica). Conversely, the organic matter (OM) of the deeper mats showed evidence for a higher seagrass contribution [high C/N, 13C-depleted long-chain n-alkanes]. The morphological structure of the mats may have influenced CO2 diffusion leading to more 13C-enriched lipids in the shallow mats. Alternatively, changes in CO2 fixation pathways, such as increase in the acetyl COA-pathway by sulphate-reducing bacteria, could have also caused the observed shifts in δ13C values of the mats. In addition, three smooth mats from different Shark Bay sites were analysed to investigate potential functional relationship of the microbial communities with differing salinity levels. The C25:1 HBI was identified in the high salinity mat only and a lower abundance of PLFAs associated with diatoms was observed in the less saline mats, suggesting a higher abundance of diatoms at the most saline site. Furthermore, it appeared that the most and least saline mats were dominated by autotrophic biomass using different CO2 fixation pathways. © 2014 John Wiley & Sons Ltd.

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 the FeOB create the structure of the environment for the entire microbial community, acting as environmental engineers. Furthermore, they leave behind distinctive signatures of environmental conditions (e.g. presence of oxygen, hydrothermal pulsing), which can be recorded in the rock record.

Speeding up pyrogenicity testing: Identification of suitable cell components and readout parameters for an accelerated monocyte activation test (MAT).

PubMed

Stoppelkamp, Sandra; Würschum, Noriana; Stang, Katharina; Löder, Jasmin; Avci-Adali, Meltem; Toliashvili, Leila; Schlensak, Christian; Wendel, Hans Peter; Fennrich, Stefan

2017-02-01

Pyrogen testing represents a crucial safety measure for parental drugs and medical devices, especially in direct contact with blood or liquor. The European Pharmacopoeia regulates these quality control measures for parenterals. Since 2010, the monocyte activation test (MAT) has been an accepted pyrogen test that can be performed with different human monocytic cell sources: whole blood, isolated monocytic cells or monocytic cell lines with IL1β, IL6, or TNFα as readout cytokines. In the present study, we examined the three different cell sources and cytokine readout parameters with the scope of accelerating the assay time. We could show that despite all cell types being able to detect pyrogens, primary cells were more sensitive than the monocytic cell line. Quantitative real-time PCR revealed IL6 mRNA transcripts having the largest change in Ct-values upon LPS-stimulation compared to IL1β and TNFα, but quantification was unreliable. IL6 protein secretion from whole blood or peripheral blood mononuclear cells (PBMC) was also best suited for an accelerated assay with a larger linear range and higher signal-to-noise ratios upon LPS-stimulation. The unique combination with propan-2-ol or a temperature increase could additionally increase the cytokine production for earlier detection in PBMC. The increased incubation temperature could finally increase not only responses to lipopolysaccharides (LPS) but also other pyrogens by up to 13-fold. Therefore, pyrogen detection can be accelerated considerably by using isolated primary blood cells with an increased incubation temperature and IL6 as readout. These results could expedite assay time and thus help to promote further acceptance of the MAT. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

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 Borassus mats, were not effective in rainsplash erosion control. Both mats did not significantly ( P > 0.05) improve selected soil properties (i.e., soil organic matter, particle size distribution, aggregate stability and total soil carbon) as soil organic matter (SOM) input from mat-decomposition was much less than total SOM content. However, the changes in fine and medium sand contents (after 2 years) in the Borassus covered plots were significantly ( P < 0.05; n = 6) related to the total rainsplash erosion during 2007‒2009. Emplacement of Borassus and Buriti mats on bare soils did not decrease SOM contents after 2 years, indicating that improvements in some soil properties might occur over longer durations. After ˜ 10 months, Buriti mats lost ˜ 70% of their initial weight ( P < 0.001) and their initial cover percentage ( C, %) decreased drastically ( P < 0.05); whereas, Borassus mats maintained similar C to the initial condition, although mass per unit area decreased by ˜ 20% ( P < 0.05). Moreover, the functional longevity of Borassus mats was ˜ 2 years against only 1 year for Buriti mats. Hence, use of Borassus mats is highly effective for rainsplash erosion control in the UK.

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.

Toxoplasma gondii in stranded marine mammals from the North Sea and Eastern Atlantic Ocean: Findings and diagnostic difficulties.

PubMed

van de Velde, Norbert; Devleesschauwer, Brecht; Leopold, Mardik; Begeman, Lineke; IJsseldijk, Lonneke; Hiemstra, Sjoukje; IJzer, Jooske; Brownlow, Andrew; Davison, Nicholas; Haelters, Jan; Jauniaux, Thierry; Siebert, Ursula; Dorny, Pierre; De Craeye, Stéphane

2016-10-30

The occurrence of the zoonotic protozoan parasite Toxoplasma gondii in marine mammals remains a poorly understood phenomenon. In this study, samples from 589 marine mammal species and 34 European otters (Lutra lutra), stranded on the coasts of Scotland, Belgium, France, The Netherlands and Germany, were tested for the presence of T. gondii. Brain samples were analysed by polymerase chain reaction (PCR) for detection of parasite DNA. Blood and muscle fluid samples were tested for specific antibodies using a modified agglutination test (MAT), a commercial multi-species enzyme-linked immunosorbent assay (ELISA) and an immunofluorescence assay (IFA). Out of 193 animals tested by PCR, only two harbour porpoise (Phocoena phocoena) cerebrum samples, obtained from animals stranded on the Dutch coast, tested positive. The serological results showed a wide variation depending on the test used. Using a cut-off value of 1/40 dilution in MAT, 141 out of 292 animals (41%) were positive. Using IFA, 30 out of 244 tested samples (12%) were positive at a 1/50 dilution. The commercial ELISA yielded 7% positives with a cut-off of the sample-to-positive (S/P) ratio≥50; and 12% when the cut-off was set at S/P ratio≥20. The high number of positives in MAT may be an overestimation due to the high degree of haemolysis of the samples and/or the presence of lipids. The ELISA results could be an underestimation due to the use of a multispecies conjugate. Our results confirm the presence of T. gondii in marine mammals in The Netherlands and show exposure to the parasite in both the North Sea and the Eastern Atlantic Ocean. We also highlight the limitations of the tests used to diagnose T. gondii in stranded marine mammals. Copyright © 2016 Elsevier B.V. All rights reserved.

A new experimental material for modeling relief dynamics and interactions between tectonics and surface processes

NASA Astrophysics Data System (ADS)

Graveleau, F.; Hurtrez, J.-E.; Dominguez, S.; Malavieille, J.

2011-12-01

We developed a new granular material (MatIV) to study experimentally landscape evolution in active mountain belt piedmonts. Its composition and related physical properties have been determined using empirical criteria derived from the scaling of deformation, erosion-transport and sedimentation natural processes. MatIV is a water-saturated composite material made up with 4 granular components (silica powder, glass microbeads, plastic powder and graphite) whose physical, mechanical and erosion-related properties were measured with different laboratory tests. Mechanical measurements were made on a modified Hubbert-type direct shear apparatus. Erosion-related properties were determined using an experimental set-up that allows quantifying the erosion/sedimentation budget from tilted relaxation topographies. For MatIV, we also investigated the evolution of mean erosion rates and stream power erosion law exponents in 1D as a function of slope. Our results indicate that MatIV satisfies most of the defined criteria. It deforms brittlely according to the linear Mohr-Coulomb failure criterion and localizes deformation along discrete faults. Its erosion pattern is characterized by realistic hillslope and channelized processes (slope diffusion, mass wasting, channel incision). During transport, eroded particles are sorted depending on their density and shape, which results in stratified alluvial deposits displaying lateral facies variations. To evaluate the degree of similitude between model and nature, we used a new experimental device that combines accretionary wedge deformation mechanisms and surface runoff erosion processes. Results indicate that MatIV succeeded in producing detailed morphological and sedimentological features (drainage basin, channel network, terrace, syntectonic alluvial fan). Geometric, kinematic and dynamic similarity criteria have been investigated to compare precisely model to nature. Although scaling is incomplete, it yields particularly informative orders of magnitude. With all these characteristics, MatIV appears as a very promising material to investigate experimentally a wide range of scientific questions dealing with relief dynamics and interactions between tectonics, erosion and sedimentation processes.

Factors affecting stall use for different freestall bases.

PubMed

Wagner-Storch, A M; Palmer, R W; Kammel, D W

2003-06-01

The objective of this study was to compare stall use (stall occupancy and cow position) by barn side for factors affecting stall use. A closed circuit television system recorded stall use four times per day for a 9-mo period starting May 9, 2001. Six factors were analyzed: stall base, distance to water, stall location within stall base section, stall location within barn, inside barn temperature, and length of time cows were exposed to stall bases. Two barn sides with different stocking densities were analyzed: low (66%), with cows milked by robotic milker; and high (100%), with cows milked 2X in parlor. Six stall base types were tested: two mattresses, a waterbed, a rubber mat, concrete, and sand (high side only). The base types were grouped 3 to 7 stalls/section and randomly placed in each row. Cows spent more time in mattress-based stalls, but the highest percentage lying was in sand-based stalls. The following significant stall occupancy percentages were found: sand had the highest percentage of cows lying on the high stocking density side (69%), followed by mattress type 1 (65%) > mattress type 2 (57%) > waterbed (45%) > rubber mat (33%) > concrete (23%). Mattress type 1 had the highest percentage stalls occupied (88%), followed by mattress type 2 (84%) > sand (79%) > soft rubber mat (65%) > waterbed (62%) > concrete (39%). On the low stocking rate side, mattress type 1 had the highest percentage cows lying (45%) and occupied (59.6%), followed by mattress type 2 > waterbed > soft rubber mat > concrete. Cow lying and stalls occupied percentages were highest for stalls 1) not at the end of a section, and 2) on the outside row, and varied by base type for time cows exposed to stalls and inside barn temperature. Lying and occupied percentages were different for different mattress types. The percentage of stalls with cows standing was higher for mat and mattress-based stalls. Results show mattress type 1 and sand to be superior and rubber mats and concrete inferior stall bases.

γ-Fe2O3 nanoparticles filled polyvinyl alcohol as potential biomaterial for tissue engineering scaffold.

PubMed

Ngadiman, Nor Hasrul Akhmal; Idris, Ani; Irfan, Muhammad; Kurniawan, Denni; Yusof, Noordin Mohd; Nasiri, Rozita

2015-09-01

Maghemite (γ-Fe2O3) nanoparticle with its unique magnetic properties is recently known to enhance the cell growth rate. In this study, γ-Fe2O3 is mixed into polyvinyl alcohol (PVA) matrix and then electrospun to form nanofibers. Design of experiments was used to determine the optimum parameter settings for the electrospinning process so as to produce elctrospun mats with the preferred characteristics such as good morphology, Young's modulus and porosity. The input factors of the electrospinnning process were nanoparticles content (1-5%), voltage (25-35 kV), and flow rate (1-3 ml/h) while the responses considered were Young's modulus and porosity. Empirical models for both responses as a function of the input factors were developed and the optimum input factors setting were determined, and found to be at 5% nanoparticle content, 35 kV voltage, and 1 ml/h volume flow rate. The characteristics and performance of the optimum PVA/γ-Fe2O3 nanofiber mats were compared with those of neat PVA nanofiber mats in terms of morphology, thermal properties, and hydrophilicity. The PVA/γ-Fe2O3 nanofiber mats exhibited higher fiber diameter and surface roughness yet similar thermal properties and hydrophilicity compared to neat PVA PVA/γ-Fe2O3 nanofiber mats. Biocompatibility test by exposing the nanofiber mats with human blood cells was performed. In terms of clotting time, the PVA/γ-Fe2O3 nanofibers exhibited similar behavior with neat PVA. The PVA/γ-Fe2O3 nanofibers also showed higher cells proliferation rate when MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay was done using human skin fibroblast cells. Thus, the PVA/γ-Fe2O3 electrospun nanofibers can be a promising biomaterial for tissue engineering scaffolds. Copyright © 2015 Elsevier Ltd. All rights reserved.

Marrow Adipose Tissue Quantification of the Lumbar Spine by Using Dual-Energy CT and Single-Voxel 1H MR Spectroscopy: A Feasibility Study

PubMed Central

Daley, Scott M.; Kalra, Mannudeep K.; Brown, J. Keenan; Miller, Karen K.; Torriani, Martin

2015-01-01

Purpose To test the performance of dual-energy computed tomography (CT) in the assessment of marrow adipose tissue (MAT) content of the lumbar spine by using proton (hydrogen 1 [1H]) magnetic resonance (MR) spectroscopy as a reference standard and to determine the influence of MAT on the assessment of bone mineral density (BMD). Materials and Methods This study was institutional review board approved and complied with HIPAA guidelines. Written informed consent was obtained. Twelve obese osteopenic but otherwise healthy subjects (mean age ± standard deviation, 43 years ± 13) underwent 3-T 1H MR spectroscopy of the L2 vertebra by using a point-resolved spatially localized spectroscopy sequence without water suppression. The L2 vertebra was scanned with dual-energy CT (80 and 140 kV) by using a dual-source multi–detector row CT scanner with a calibration phantom. Mean basis material composition relative to the phantom was estimated in the L2 vertebra. Volumetric BMD was measured with and without correction for MAT. Bland-Altman 95% limits of agreement and Pearson correlation coefficients were calculated. Results There was excellent agreement between 1H MR spectroscopy and dual-energy CT, with a mean difference in fat fraction of −0.02 between the techniques, with a 95% confidence interval of −0.24, 0.20. There was a strong correlation between marrow fat fraction obtained with 1H MR spectroscopy and that obtained with dual-energy CT (r = 0.91, P < .001). The presence of MAT led to underestimation of BMD, and this bias increased with increasing MAT content (P < .001). Conclusion Dual-energy CT can be used to assess MAT content and BMD of the lumbar spine in a single examination and provides data that closely agree and correlate with 1H MR spectroscopy data. © RSNA, 2015 PMID:25988401

Graft extrusion in both the coronal and sagittal planes is greater after medial compared with lateral meniscus allograft transplantation but is unrelated to early clinical outcomes.

PubMed

Lee, Dae-Hee; Lee, Chang-Rack; Jeon, Jin-Ho; Kim, Kyung-Ah; Bin, Seong-Il

2015-01-01

Graft extrusion after meniscus allograft transplantation (MAT) may be affected by horn fixation, which differs between medial and lateral MAT. Few studies have compared graft extrusion, especially sagittal extrusion, after medial and lateral MAT. In patients undergoing medial and lateral MAT, graft extrusion is likely similar and not correlated with postoperative Lysholm scores. Cohort study; Level of evidence, 2. Meniscus graft extrusion in the coronal and sagittal planes was compared in 51 knees undergoing medial MAT and 84 undergoing lateral MAT. Distances from the anterior and posterior articular cartilage margins to the anterior (anterior cartilage meniscus distance [ACMD]) and posterior (posterior cartilage meniscus distance [PCMD]) horns, respectively, were assessed on immediate postoperative magnetic resonance imaging and compared in patients undergoing medial and lateral MAT. Correlations between coronal and sagittal graft extrusion and between extrusion and the Lysholm score were compared in the 2 groups. In the coronal plane, mean absolute (4.3 vs 2.7 mm, respectively; P<.001) and relative (39% vs 21%, respectively; P<.001) graft extrusions were significantly greater for medial than lateral MAT. In the sagittal plane, mean absolute and relative ACMD and PCMD values were significantly greater for medial than lateral MAT (P<.001 each). For both medial and lateral MAT, mean absolute and relative ACMDs were significantly larger than PCMDs (P<.001 each). Graft extrusion>3 mm in the coronal plane was significantly more frequent in the medial (78%) than in the lateral (35%) MAT group. In the sagittal plane, the frequencies of ACMDs (72% vs 39%, respectively) and PCMDs (23% vs 4%, respectively) >3 mm were also significantly greater in the medial than in the lateral MAT group. Coronal and sagittal extrusions were not correlated with postoperative Lysholm scores for both medial and lateral MAT. The amount and incidence of graft extrusion were greater after medial than lateral MAT in both the coronal and sagittal planes. In the sagittal plane, graft extrusion was greater and more frequent on the anterior than the posterior horn in both medial and lateral MAT. However, graft extrusion was not correlated with early clinical outcomes after both medial and lateral MAT. © 2014 The Author(s).

Microbialite Biosignature Analysis by Mesoscale X-ray Fluorescence (μXRF) Mapping.

PubMed

Tice, Michael M; Quezergue, Kimbra; Pope, Michael C

2017-11-01

As part of its biosignature detection package, the Mars 2020 rover will carry PIXL, the Planetary Instrument for X-ray Lithochemistry, a spatially resolved X-ray fluorescence (μXRF) spectrometer. Understanding the types of biosignatures detectable by μXRF and the rock types μXRF is most effective at analyzing is therefore an important goal in preparation for in situ Mars 2020 science and sample selection. We tested mesoscale chemical mapping for biosignature interpretation in microbialites. In particular, we used μXRF to identify spatial distributions and associations between various elements ("fluorescence microfacies") to infer the physical, biological, and chemical processes that produced the observed compositional distributions. As a test case, elemental distributions from μXRF scans of stromatolites from the Mesoarchean Nsuze Group (2.98 Ga) were analyzed. We included five fluorescence microfacies: laminated dolostone, laminated chert, clotted dolostone and chert, stromatolite clast breccia, and cavity fill. Laminated dolostone was formed primarily by microbial mats that trapped and bound loose sediment and likely precipitated carbonate mud at a shallow depth below the mat surface. Laminated chert was produced by the secondary silicification of microbial mats. Clotted dolostone and chert grew as cauliform, cryptically laminated mounds similar to younger thrombolites and was likely formed by a combination of mat growth and patchy precipitation of early-formed carbonate. Stromatolite clast breccias formed as lag deposits filling erosional scours and interstromatolite spaces. Cavities were filled by microquartz, Mn-rich dolomite, and partially dolomitized calcite. Overall, we concluded that μXRF is effective for inferring genetic processes and identifying biosignatures in compositionally heterogeneous rocks. Key Words: Stromatolites-Biosignatures-Spectroscopy-Archean. Astrobiology 17, 1161-1172.

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.

Rewetting effects on soil CO2 flux and nutrients leaching in alpine Kobresia pasture on the Tibetan Plateau

NASA Astrophysics Data System (ADS)

Liu, Shibin; Schleuss, Per; Kuzyakov, Yakov

2015-04-01

Kobresia pygmaea pastures of the Tibetan Plateau are one of the most important ecosystems around the world due to its large grazing area and very high soil organic carbon storage. Since the last decades grasslands of the TP are highly affected by grassland degradation because of various sedimentary programs and strongly increase grazing pressure. Climate changes (e.g. increased precipitation and temperature) may accelerate this degradation processes by enhancing soil organic matter mineralization and nutrients leaching. We exposed repeated rewetting cycles to test the effects of increased precipitation frequency on CO2 fluxes and leaching on varying K. pygmaea root mats (including: intact root mats (KL); recently died root mats (KD); crust covered root mats (LI)). Two phases were conducted (a) to identify the response of nighttime CO2 flux to changing soil moisture and (b) to investigate the impacts of rewetting cycles on day-, night-, and full day CO2 fluxes together with leaching of carbon (C) and nitrogen (N). Nighttime CO2 fluxes correlated positively with soil moisture, indicating that increasing precipitation will accelerate SOC losses due to increasing mineralization rates. KD showed highest C losses as CO2 efflux and also the highest leaching compared to KL and LI. It indicates that dying of Kobresia root mats (as induced by overgrazing and continuously removal of photosynthetically active shoot biomass) will rapidly decrease SOC storage. The lowest C losses (from soil respiration and DOC leaching) were obtained in the crust covered root mats (LI), because most C losses have already occurred during the early period. Highest N losses (especially NO3-) were obtained in the highly degraded pasture (LI). Due to long-term SOM decomposition of crust covered root mats (LI) in situ, inorganic nitrogen (NO3-) was accumulated in and was leached out during the first rewetting cycles. In contrast, no losses of NH4+ and NO3- occurred for intact Kobresia root mats (KL), because the plants took up mineral nitrogen. These results were consistent to very low C/N ratios of leachates in crust-covered root mats. The low C/N ratio in LI was mainly connected by nitrogen accumulation before leaching, whereas the slightly lower C/N ratio in KD was mainly affected by carbon losses (DOC) due to increased SOM decomposition. This study indicates that in combination overgrazing and precipitation change might strongly reduce SOC storage. Furthermore, the high nutrient losses after initial degradation of these N and P limited grasslands might have dramatic consequences for this ecosystem. Therefore, saving and restoration of natural vegetation cover by decreasing grazing intensities is the only strategy to maintain soil fertility and protect Kobresia ecosystems against degradation.

A wide variety of injection molding technologies is now applicable to small series and mass production

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

Bloß, P., E-mail: bloss@kuz-leipzig.de, E-mail: juettner@kuz-leipzig.de, E-mail: jacob@kuz-leipzig.de, E-mail: loeser@kuz-leipzig.de, E-mail: michaelis@kuz-leipzig.de, E-mail: krajewsky@kuz-leipzig.de; Jüttner, G., E-mail: bloss@kuz-leipzig.de, E-mail: juettner@kuz-leipzig.de, E-mail: jacob@kuz-leipzig.de, E-mail: loeser@kuz-leipzig.de, E-mail: michaelis@kuz-leipzig.de, E-mail: krajewsky@kuz-leipzig.de; Jacob, S., E-mail: bloss@kuz-leipzig.de, E-mail: juettner@kuz-leipzig.de, E-mail: jacob@kuz-leipzig.de, E-mail: loeser@kuz-leipzig.de, E-mail: michaelis@kuz-leipzig.de, E-mail: krajewsky@kuz-leipzig.de

2014-05-15

Micro plastic parts open new fields for application, e. g., to electronics, sensor technologies, optics, and medical engineering. Before micro parts can go to mass production, there is a strong need of having the possibility for testing different designs and materials including material combinations. Hence, flexible individual technical and technological solutions for processing are necessary. To manufacture high quality micro parts, a micro injection moulding machine named formicaPlast based on a two-step plunger injection technology was developed. Resulting from its design, the residence time and the accuracy problems for managing small shot volumes with reproducible high accuracy are uncompromisingly solved.more » Due to their simple geometry possessing smooth transitions and non adherent inner surfaces, the plunger units allow to process 'all' thermoplastics from polyolefines to high performance polymers, optical clear polymers, thermally sensitive bioresorbables, highly filled systems (the so-called powder injection molding PIM), and liquid silicon rubber (LSR, here with a special kit). The applied platform strategy in the 1K and 2K version allows integrating automation for assembling, handling and packaging. A perpendicular arrangement allows encapsulation of inserts, also partially, and integration of this machine into process chains. Considering a wide variety of different parts consisting of different materials, the high potential of the technology is demonstrated. Based on challenging industrial parts from electronic applications (2K micro MID and bump mat, where both are highly structured parts), the technological solutions are presented in more detail.« less

Advanced algorithms for the identification of mixtures using condensed-phase FT-IR spectroscopy

NASA Astrophysics Data System (ADS)

Arnó, Josep; Andersson, Greger; Levy, Dustin; Tomczyk, Carol; Zou, Peng; Zuidema, Eric

2011-06-01

FT-IR spectroscopy is the technology of choice to identify solid and liquid phase unknown samples. Advances in instrument portability have made possible the use of FT-IR spectroscopy in emergency response and military field applications. The samples collected in those harsh environments are rarely pure and typically contain multiple chemical species in water, sand, or inorganic matrices. In such critical applications, it is also desired that in addition to broad chemical identification, the user is warned immediately if the sample contains a threat or target class material (i.e. biological, narcotic, explosive). The next generation HazMatID 360 combines the ruggedized design and functionality of the current HazMatID with advanced mixture analysis algorithms. The advanced FT-IR instrument allows effective chemical assessment of samples that may contain one or more interfering materials like water or dirt. The algorithm was the result of years of cumulative experience based on thousands of real-life spectra sent to our ReachBack spectral analysis service by customers in the field. The HazMatID 360 combines mixture analysis with threat detection and chemical hazard classification capabilities to provide, in record time, crucial information to the user. This paper will provide an overview of the software and algorithm enhancements, in addition to examples of improved performance in mixture identification.

Automatic content-based analysis of georeferenced image data: Detection of Beggiatoa mats in seafloor video mosaics from the HÅkon Mosby Mud Volcano

NASA Astrophysics Data System (ADS)

Jerosch, K.; Lüdtke, A.; Schlüter, M.; Ioannidis, G. T.

2007-02-01

The combination of new underwater technology as remotely operating vehicles (ROVs), high-resolution video imagery, and software to compute georeferenced mosaics of the seafloor provides new opportunities for marine geological or biological studies and applications in offshore industry. Even during single surveys by ROVs or towed systems large amounts of images are compiled. While these underwater techniques are now well-engineered, there is still a lack of methods for the automatic analysis of the acquired image data. During ROV dives more than 4200 georeferenced video mosaics were compiled for the HÅkon Mosby Mud Volcano (HMMV). Mud volcanoes as HMMV are considered as significant source locations for methane characterised by unique chemoautotrophic communities as Beggiatoa mats. For the detection and quantification of the spatial distribution of Beggiatoa mats an automated image analysis technique was developed, which applies watershed transformation and relaxation-based labelling of pre-segmented regions. Comparison of the data derived by visual inspection of 2840 video images with the automated image analysis revealed similarities with a precision better than 90%. We consider this as a step towards a time-efficient and accurate analysis of seafloor images for computation of geochemical budgets and identification of habitats at the seafloor.

Discovery of a Leptospirosis Cluster Amidst a Pneumonic Plague Outbreak in a Miners’ Camp in the Democratic Republic of the Congo

PubMed Central

Bertherat, Eric; Mueller, Melissa J.; Shako, Jean-Christophe; Picardeau, Mathieu

2014-01-01

Conditions in the Democratic Republic of the Congo provide an ideal environment for leptospirosis and plague, both of which can cause severe pulmonary manifestations. In December 2004, an outbreak of lethal pneumonia occurred in a local mining camp, affecting 130 persons and killing 57 of them. Clinical signs, fast disease spread, and initial laboratory investigations suggested pneumonic plague. While leptospirosis had not recently been described in the region, it was considered as a differential diagnosis. Anti-Leptospira antibodies were detected by microscopic agglutination test (MAT). A confirmed case of leptospirosis was defined as having consistent clinical signs and any one of the following: seroconversion or four-fold increase in MAT titre for paired serum samples, or a MAT titre ≥ 1:400 for acute-phase serum samples. Twenty-nine of the 54 patients or convalescents tested for leptospirosis were seropositive. Two cases showed a confirmed infection for both plague and leptospirosis. While evidence supports the plague nature of this outbreak, the results suggest that some of the suspected plague cases might be due to leptospirosis. In any case, this diagnosis will have to be evoked in the future if a similar outbreak occurs in this region of Africa. PMID:24514425

Discovery of a leptospirosis cluster amidst a pneumonic plague outbreak in a miners' camp in the Democratic Republic of the Congo.

PubMed

Bertherat, Eric; Mueller, Melissa J; Shako, Jean-Christophe; Picardeau, Mathieu

2014-02-07

Conditions in the Democratic Republic of the Congo provide an ideal environment for leptospirosis and plague, both of which can cause severe pulmonary manifestations. In December 2004, an outbreak of lethal pneumonia occurred in a local mining camp, affecting 130 persons and killing 57 of them. Clinical signs, fast disease spread, and initial laboratory investigations suggested pneumonic plague. While leptospirosis had not recently been described in the region, it was considered as a differential diagnosis. Anti-Leptospira antibodies were detected by microscopic agglutination test (MAT). A confirmed case of leptospirosis was defined as having consistent clinical signs and any one of the following: seroconversion or four-fold increase in MAT titre for paired serum samples, or a MAT titre ≥ 1:400 for acute-phase serum samples. Twenty-nine of the 54 patients or convalescents tested for leptospirosis were seropositive. Two cases showed a confirmed infection for both plague and leptospirosis. While evidence supports the plague nature of this outbreak, the results suggest that some of the suspected plague cases might be due to leptospirosis. In any case, this diagnosis will have to be evoked in the future if a similar outbreak occurs in this region of Africa.

Quantitative analysis of Ostracoda and water masses around Japan: Application to Pliocene and Pleistocene paleoceanography

USGS Publications Warehouse

Ikeya, Noriyuki; Cronin, Thomas M.

1993-01-01

An ostracode data base consisting of 273 samples from coretops and comprising 226 species was developed for the seas around the Japanese Islands to determine zoogeographic patterns and for application to Pliocene and Pleistocene paleoceanography in the area. Quantitative analyses of the 59 most common taxa between 0 and 300m water depth indicate that ostracode associations are controlled by the main oceanic water masses around Japan and that bottom water temperature is a key factor influencing species distributions. Ostracodes from the following water masses were studied: warm Kuroshio Current, Tsushima Current (Tsugaru Current and Soya Current), Japan Sea intermediate water, Japan Sea proper water and cold Oyashio Current. In order to apply the modem coretop data base to fossil ostracode assemblages, the modem analog technique (MAT) using a squared chord distance (SCD) measure of dissimilarity was tested as a means of comparing fossil and modem assemblages. SCD values of 0.25 or less adequately identify modem analogs from the coretop data set at the local ecological level (i.e. within the same modern bay), while values of 0.25-0.5 identify modem analogs at the level of the zoogeographic province. The MAT method was tested against 3 Pliocene and 11 Pleistocene formations in Japan to examine the use of the MAT in paleoceanographic reconstruction.

DNA barcoding of perennial fruit tree species of agronomic interest in the genus Annona (Annonaceae)

PubMed Central

Larranaga, Nerea; Hormaza, José I.

2015-01-01

The DNA barcode initiative aims to establish a universal protocol using short genetic sequences to discriminate among animal and plant species. Although many markers have been proposed to become the barcode of plants, the Consortium for the Barcode of Life (CBOL) Plant Working Group recommended using as a core the combination of two portions of plastid coding region, rbcL and matK. In this paper, specific markers based on matK sequences were developed for 7 closely related Annona species of agronomic interest (Annona cherimola, A. reticulata, A. squamosa, A. muricata, A. macroprophyllata, A. glabra, and A. purpurea) and the discrimination power of both rbcL and matK was tested using also sequences of the genus Annona available in the Barcode of Life Database (BOLD) data systems. The specific sequences developed allowed the discrimination among all those species tested. Moreover, the primers generated were validated in six additional species of the genus (A. liebmanniana, A. longiflora, A. montana, A. senegalensis, A. emarginata and A. neosalicifolia) and in an interspecific hybrid (A. cherimola x A. squamosa). The development of a fast, reliable and economic approach for species identification in these underutilized subtropical fruit crops in a very initial state of domestication is of great importance in order to optimize genetic resource management. PMID:26284104

Experimental evaluation and design of unfilled and concrete-filled FRP composite piles : Task 5 : laminate durability testing : final report.

DOT National Transportation Integrated Search

2015-05-01

The overall goal of this project is the experimental evaluation and design of unfilled and concrete-filled FRP composite piles for load-bearing in bridges. This report covers Task 5, Laminate Durability Testing. : Mechanical properties of the FRP mat...

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.

Electrospun antimicrobial hybrid mats: Innovative packaging material for meat and meat-products.

PubMed

Amna, Touseef; Yang, Jieun; Ryu, Kyeong-Seon; Hwang, I H

2015-07-01

To prevent the development and spread of spoilage/pathogenic microorganisms via meat foodstuffs, antimicrobial nanocomposite packaging can serve as a potential alternative. The objective of this study was to develop a new class of antimicrobial hybrid packaging mat composed of biodegradable polyurethane supplemented with virgin olive oil and zinc oxide via electrospinning. Instead of mixing antimicrobial compounds directly with food, incorporation in packaging materials allows the functional effect at food surfaces where microbial activity is localized. The nanofibers were characterized by SEM, EDX, XRD and TEM. The antibacterial activity was tested against two common foodborne pathogens viz., Staphylococcus aureus and Salmonella typhimurium. The present results indicated that incorporation of olive oil in the polymer affected morphology of PU nanofibers and nanocomposite packaging were able to inhibit growth of pathogens. Thus; as-spun mat can be used as prospective antimicrobial packaging, which potentially reduces contamination of meat/meat-products. Moreover, introduced biodegradable packaging for meat products could serve to replace PVC films and simultaneously help to protect natural environment.

Discriminatory power of rbcL barcode locus for authentication of some of United Arab Emirates (UAE) native plants.

PubMed

Maloukh, Lina; Kumarappan, Alagappan; Jarrar, Mohammad; Salehi, Jawad; El-Wakil, Houssam; Rajya Lakshmi, T V

2017-06-01

DNA barcoding of United Arab Emirates (UAE) native plants is of high practical and scientific value as the plants adapt to very harsh environmental conditions that challenge their identification. Fifty-one plant species belonged to 22 families, 2 monocots, and 20 eudicots; a maximum number of species being legumes and grasses were collected. To authenticate the morphological identification of the wild plant taxa, rbcL and matK regions were used in the study. The primer universality and discriminatory power of rbcL is 100%, while it is 35% for matK locus for these plant species. The sequences were submitted to GenBank; accession numbers were obtained for all the rbcL sequences and for 6 of matK sequences. We suggest rbcL as a promising barcode locus for the tested group of 51 plants. In the present study, an inexpensive, simple method of identification of rare desert plant taxa through rbcL barcode is being reported.

2010 ACVIM Small Animal Consensus Statement on Leptospirosis: Diagnosis, Epidemiology, Treatment, and Prevention

PubMed Central

Sykes, JE; Hartmann, K; Lunn, KF; Moore, GE; Stoddard, RA; Goldstein, RE

2011-01-01

This report offers a consensus opinion on the diagnosis, epidemiology, treatment, and prevention of leptospirosis in dogs, an important zoonosis. Clinical signs of leptospirosis in dogs relate to development of renal disease, hepatic disease, uveitis, and pulmonary hemorrhage. Disease may follow periods of high rainfall, and can occur in dogs roaming in proximity to water sources, farm animals, or wildlife, or dogs residing in suburban environments. Diagnosis is based on acute and convalescent phase antibody titers by the microscopic agglutination test (MAT), with or without use of polymerase chain reaction assays. There is considerable interlaboratory variation in MAT results, and the MAT does not accurately predict the infecting serogroup. The recommended treatment for optimal clearance of the organism from renal tubules is doxycycline, 5 mg/kg PO q12h, for 14 days. Annual vaccination can prevent leptospirosis caused by serovars included in the vaccine and is recommended for dogs at risk of infection. PMID:21155890

Measuring modules for the research of compensators of reactive power with voltage stabilization in MATLAB

NASA Astrophysics Data System (ADS)

Vlasayevsky, Stanislav; Klimash, Stepan; Klimash, Vladimir

2017-10-01

A set of mathematical modules was developed for evaluation the energy performance in the research of electrical systems and complexes in the MatLab. In the electrotechnical library SimPowerSystems of the MatLab software, there are no measuring modules of energy coefficients characterizing the quality of electricity and the energy efficiency of electrical apparatus. Modules are designed to calculate energy coefficients characterizing the quality of electricity (current distortion and voltage distortion) and energy efficiency indicators (power factor and efficiency) are presented. There are described the methods and principles of building the modules. The detailed schemes of modules built on the elements of the Simulink Library are presented, in this connection, these modules are compatible with mathematical models of electrical systems and complexes in the MatLab. Also there are presented the results of the testing of the developed modules and the results of their verification on the schemes that have analytical expressions of energy indicators.

Potential Alternatives Report for Validation of Alternative Low-Emission Surface PreparationlDepainting Technologies for Structural Steel

NASA Technical Reports Server (NTRS)

Lewis, Pattie

2006-01-01

For this project, particulates and solvents used during the depainting process of steel structures were the identified hazardous material (HazMat) targeted for elimination or reduction. This Potential Alternatives Report (PAR) provides technical analyses of identified alternatives to the current coating removal processes, criteria used to select alternatives for further analysis, and a list of those alternatives recommended for testing. The initial coating removal alternatives list was compiled using literature searches and center participant recommendations. The involved project participants initially considered fifteen (15) alternatives. In late 2004, stakeholders down-selected the list and identified specific processes as potential alternatives to the current depainting methods. The selected alternatives were: 1. Plastic Blast Media 2. Hard Abrasive Media 3. Sponge Blast Media 4. Mechanical Removal with Vacuum Attachment 5. Liquid Nitrogen 6. Laser Coating Removal Available information about these processes was used to analyze the technical merits and the potential environmental, safety, and occupational health (ESOH) impacts of these methods. A preliminary cost benefit analysis will be performed to determine if implementation of alternative technologies is economically justified. NASA AP2

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 analysis (via elemental analysis IRMS and gas bench IRMS) we are employing laser ablation IRMS (LA-IRMS) to provide a spatially-resolved accounting of label uptake through the mat cross section. This technique permits isotope analysis at the 50 μm scale, and can provide multiple isotope analyses within each mat strata. By coupling LA-IRMS analysis with laminar sectioning of the mat and amplicon sequencing of the rrnA gene, we seek to establish linkages between phylogeny and function over the course of a diel cycle with highlighted emphasis on evidence of carbon transfer between mat laminae and the phylotypes that inhabit them. We are also using a series of carbon accumulation microcosms to quantify net carbon fixation over the seasonal cycle. These microcosms are deployed at multiple depths to provide an accounting of carbon cycling under the specific geochemical conditions experienced at variable depth. Coupling the data from these individual microcosms to our bathymetric survey of Hot Lake permits us to estimate total mat carbon fixation, and therefore to begin to assess the impact of the mat on the greater lake carbon cycle.

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.

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.

DD3MAT - a code for yield criteria anisotropy parameters identification.

NASA Astrophysics Data System (ADS)

Barros, P. D.; Carvalho, P. D.; Alves, J. L.; Oliveira, M. C.; Menezes, L. F.

2016-08-01

This work presents the main strategies and algorithms adopted in the DD3MAT inhouse code, specifically developed for identifying the anisotropy parameters. The algorithm adopted is based on the minimization of an error function, using a downhill simplex method. The set of experimental values can consider yield stresses and r -values obtained from in-plane tension, for different angles with the rolling direction (RD), yield stress and r -value obtained for biaxial stress state, and yield stresses from shear tests performed also for different angles to RD. All these values can be defined for a specific value of plastic work. Moreover, it can also include the yield stresses obtained from in-plane compression tests. The anisotropy parameters are identified for an AA2090-T3 aluminium alloy, highlighting the importance of the user intervention to improve the numerical fit.

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.

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 typical shore-parallel zonality. In contrast, in tidal flats with slight changes in topography, the typical shore-parallel zonality appears disturbed mainly along the intertidal and lower supratidal zones. The mat surface structures within each tidal zone show local and lateral transitions but all evolve from an incipient flat or polygonal mat. On the mat scale, microtopographic differences are created by the mats themselves, e.g., in the form of upturned crack margins, bulges and domes. All these are small-scale topographic highs that influence the distribution of microbial activity and mat growth dynamics. In the Abu Dhabi area it is observed that smooth or polygonal mats may grade temporally into mammilate, cinder or pustular and tufted mats along an evolutionary path controlled by preferred growth along bulges and upturned crack margins. A similar temporal evolution appears in the intertidal and supratidal zones in Tunisia where local changes on mat-surface induce a variety of mat-growth struc¬tures on and along upturned crack margins, gas domes and isolated to polygonal bulges and petee ridges. References Kendall C.G.St.C, Skipwith, P.A.d'E. (1968) Recent algal mats of a Persian gulf lagoon. J. Sedim. Res., 38, 1040-1058. Logan B.W. Hoffman P. Gebelein, C.D. (1974) Algal mats, cryptalgal fabrics, and structures, Hamelin Pool, Western Australia. AAPG Mem., 22, 140-194.

Maintaining Two Mating Types: Structure of the Mating Type Locus and Its Role in Heterokaryosis in Podospora anserina

PubMed Central

Grognet, Pierre; Bidard, Frédérique; Kuchly, Claire; Tong, Laetitia Chan Ho; Coppin, Evelyne; Benkhali, Jinane Ait; Couloux, Arnaud; Wincker, Patrick; Debuchy, Robert; Silar, Philippe

2014-01-01

Pseudo-homothallism is a reproductive strategy elected by some fungi producing heterokaryotic sexual spores containing genetically different but sexually compatible nuclei. This lifestyle appears as a compromise between true homothallism (self-fertility with predominant inbreeding) and complete heterothallism (with exclusive outcrossing). However, pseudohomothallic species face the problem of maintaining heterokaryotic mycelia to fully benefit from this lifestyle, as homokaryons are self-sterile. Here, we report on the structure of chromosome 1 in mat+ and mat− isolates of strain S of the pseudohomothallic fungus Podospora anserina. Chromosome 1 contains either one of the mat+ and mat− mating types of P. anserina, which is mostly found in nature as a mat+/mat− heterokaryotic mycelium harboring sexually compatible nuclei. We identified a “mat” region ∼0.8 Mb long, devoid of meiotic recombination and containing the mating-type idiomorphs, which is a candidate to be involved in the maintenance of the heterokaryotic state, since the S mat+ and S mat− strains have different physiology that may enable hybrid-vigor-like phenomena in the heterokaryons. The mat region contains 229 coding sequences. A total of 687 polymorphisms were detected between the S mat+ and S mat− chromosomes. Importantly, the mat region is colinear between both chromosomes, which calls for an original mechanism of recombination inhibition. Microarray analyses revealed that 10% of the P. anserina genes have different transcriptional profiles in S mat+ and S mat−, in line with their different phenotypes. Finally, we show that the heterokaryotic state is faithfully maintained during mycelium growth of P. anserina, yet mat+/mat+ and mat−/mat− heterokaryons are as stable as mat+/mat− ones, evidencing a maintenance of heterokaryosis that does not rely on fitness-enhancing complementation between the S mat+ and S mat− strains. PMID:24558260

Effects of post-fracture non-weight-bearing immobilization on muscle atrophy, intramuscular and intermuscular adipose tissues in the thigh and calf.

PubMed

Yoshiko, Akito; Yamauchi, Koun; Kato, Takayuki; Ishida, Koji; Koike, Teruhiko; Oshida, Yoshiharu; Akima, Hiroshi

2018-06-09

Disuse and/or a non-weight-bearing condition changes muscle composition, with decreased skeletal muscle tissue and increased fat within (intramuscular adipose tissue, IntraMAT) and between (intermuscular adipose tissue, InterMAT) given muscles. Excessive adipose tissue contributes to dysfunctional and metabolically impaired muscle. How these adipose tissues change during orthopedic treatment (e.g., cast immobilization, daily use of crutches) is not well documented. This study aimed to quantify changes in IntraMAT, InterMAT, and thigh and calf muscle tissue during orthopedic treatment. We studied 8 patients with fifth metatarsal bone or fibular fractures. The ankle joint involved underwent plaster casting for approximately 4 weeks, with crutches used during that time. Axial T1-weighted MRI at the mid-thigh and a 30% proximal site at the calf were obtained to measure IntraMAT and InterMAT cross-sectional areas (CSAs) and skeletal muscle tissue CSA before treatment and 4 weeks afterward. Thigh and calf muscle tissue CSAs were significantly decreased from before to after treatment: thigh, 85.8 ± 7.6 to 77.1 ± 7.3 cm 2 ; calf, 53.3 ± 5.5 to 48.9 ± 5.0 cm 2 (p < 0.05). None of the IntraMAT or InterMAT changes was statistically significant. There was a relation between the percentage change of thigh IntraMAT CSA and muscle tissue CSA (r s  = -0.86, p < 0.01). The 4 weeks of treatment primarily induced skeletal muscle atrophy with less of an effect on IntraMAT or InterMAT. There is a risk of increasing IntraMAT relatively by decreasing skeletal muscle tissue size during orthopedic treatment.

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

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

The Oncogene PDRG1 Is an Interaction Target of Methionine Adenosyltransferases

PubMed Central

Garrido, Francisco; Reytor, Edel; Portillo, Francisco; Pajares, María A.

2016-01-01

Methionine adenosyltransferases MAT I and MAT III (encoded by Mat1a) catalyze S-adenosylmethionine synthesis in normal liver. Major hepatic diseases concur with reduced levels of this essential methyl donor, which are primarily due to an expression switch from Mat1a towards Mat2a. Additional changes in the association state and even in subcellular localization of these isoenzymes are also detected. All these alterations result in a reduced content of the moderate (MAT I) and high Vmax (MAT III) isoenzymes, whereas the low Vmax (MAT II) isoenzyme increases and nuclear accumulation of MAT I is observed. These changes derive in a reduced availability of cytoplasmic S-adenosylmethionine, together with an effort to meet its needs in the nucleus of damaged cells, rendering enhanced levels of certain epigenetic modifications. In this context, the putative role of protein-protein interactions in the control of S-adenosylmethionine synthesis has been scarcely studied. Using yeast two hybrid and a rat liver library we identified PDRG1 as an interaction target for MATα1 (catalytic subunit of MAT I and MAT III), further confirmation being obtained by immunoprecipitation and pull-down assays. Nuclear MATα interacts physically and functionally with the PDRG1 oncogene, resulting in reduced DNA methylation levels. Increased Pdrg1 expression is detected in acute liver injury and hepatoma cells, together with decreased Mat1a expression and nuclear accumulation of MATα1. Silencing of Pdrg1 expression in hepatoma cells alters their steady-state expression profile on microarrays, downregulating genes associated with tumor progression according to GO pathway analysis. Altogether, the results unveil the role of PDRG1 in the control of the nuclear methylation status through methionine adenosyltransferase binding and its putative collaboration in the progression of hepatic diseases. PMID:27548429

Gait of dairy cows on floors with different slipperiness.

PubMed

Telezhenko, E; Magnusson, M; Bergsten, C

2017-08-01

This study assessed the slip resistance of different types of solid flooring in cattle housing using a range of technical tests and gait analysis. Dynamic and static coefficient of friction, skid resistance, and abrasiveness were tested on concrete flooring with a smooth finish, a grooved pattern, or a tamped pattern, acid-resistant mastic asphalt, soft rubber mats, and a worn slatted concrete floor. Coefficients of friction and skid resistance were tested under clean and slurry-soiled conditions. Linear kinematic variables were assessed in 40 cows with trackway measurements after the cows passed over the floors in a straight walk. All gait variables were assessed as deviations from those obtained on the slatted concrete floor, which was used as a baseline. The coefficient of friction tests divided the floors into 3 categories: concrete flooring, which had a low coefficient of friction (0.29-0.41); mastic asphalt flooring, which had medium values (0.38-0.45); and rubber mats, which had high values (0.49-0.57). The highest abrasion (g/10 m) was on the asphalt flooring (4.48), and the concrete flooring with a tamped pattern had significantly higher abrasiveness (2.77) than the other concrete floors (1.26-1.60). Lowest values on the skid-resistance tests (dry/wet) were for smooth concrete (79/35) and mastic asphalt (65/47), especially with a slurry layer on the surface. Gait analysis mainly differentiated floors with higher friction and abrasion by longer strides and better tracking. Step asymmetry was lower on floors with high skid-resistance values. The most secure cow gait, in almost every aspect, was observed on soft rubber mats. Relationships between gait variables and physical floor characteristics ranged from average to weak (partial correlations 0.54-0.16). Thus, none of the physical characteristics alone was informative enough to characterize slip resistance. With reference to gait analysis, the abrasiveness of the hard surfaces was more informative than the coefficient of friction, but the effect of pattern was better detected by skid-resistance measurements. Consequently, several physical characteristics are needed to objectively describe the slip resistance of cattle floors. Soft rubber mats gave better tracking than hard, solid floors, even with a grooved surface or a tamped pattern. Copyright © 2017 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Unlocking Potentials of Microwaves for Food Safety and Quality

PubMed Central

Tang, Juming

2015-01-01

Microwave is an effective means to deliver energy to food through polymeric package materials, offering potential for developing short-time in-package sterilization and pasteurization processes. The complex physics related to microwave propagation and microwave heating require special attention to the design of process systems and development of thermal processes in compliance with regulatory requirements for food safety. This article describes the basic microwave properties relevant to heating uniformity and system design, and provides a historical overview on the development of microwave-assisted thermal sterilization (MATS) and pasteurization systems in research laboratories and used in food plants. It presents recent activities on the development of 915 MHz single-mode MATS technology, the procedures leading to regulatory acceptance, and sensory results of the processed products. The article discusses needs for further efforts to bridge remaining knowledge gaps and facilitate transfer of academic research to industrial implementation. PMID:26242920

Unlocking Potentials of Microwaves for Food Safety and Quality.

PubMed

Tang, Juming

2015-08-01

Microwave is an effective means to deliver energy to food through polymeric package materials, offering potential for developing short-time in-package sterilization and pasteurization processes. The complex physics related to microwave propagation and microwave heating require special attention to the design of process systems and development of thermal processes in compliance with regulatory requirements for food safety. This article describes the basic microwave properties relevant to heating uniformity and system design, and provides a historical overview on the development of microwave-assisted thermal sterilization (MATS) and pasteurization systems in research laboratories and used in food plants. It presents recent activities on the development of 915 MHz single-mode MATS technology, the procedures leading to regulatory acceptance, and sensory results of the processed products. The article discusses needs for further efforts to bridge remaining knowledge gaps and facilitate transfer of academic research to industrial implementation. © 2015 Institute of Food Technologists®

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.

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.

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.

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. Post-spin thermal annealing was used to modify the fiber morphology, inter-fiber welding, and crystallinity within the fibers. Morphological changes, in-plane tensile response, friction coefficient, and wear rate were characterized as functions of the annealing temperature. The Young's moduli, yield stresses and toughnesses of the PA 6(3)T nonwoven mats improved by two- to ten-fold when annealed slightly above the glass transition temperature, but at the expense of mat porosity. The mechanical and tribological properties of the thermally annealed P A 6,6 fiber mats exhibited significant improvements through the Brill transition temperature, comparable to the improvements observed for amorphous P A 6(3)T electrospun mats annealed near the glass transition temperature. The wear rates for both polymer systems correlate with the yield properties of the mat, in accordance with a modified Ratner-Lancaster model. The variation in mechanical and tribological properties of the mats with increasing annealing temperature is consistent with the formation of fiber-to-fiber junctions and a mechanism of abrasive wear that involves the breakage of these junctions between fibers. A mechanically robust proton exchange membrane with high ionic conductivity and selectivity is an important component in many electrochemical energy devices such as fuel cells, batteries, and photovoltaics. The ability to control and improve independently the mechanical response, ionic conductivity, and selectivity properties of a membrane is highly desirable in the development of next generation electrochemical devices. In this thesis, the use of layer-by-layer (LbL) assembly of polyelectrolytes is used to generate three different polymer film morphologies on highly porous electrospun fiber mats: webbed, conformal coating, and pore-bridging films. Specifically, depending on whether a vacuum is applied to the backside of the mat or not, the spray-LbL assembly either fills the voids of the mat with the proton conducting material or forms a continuous fuel-blocking film. The LbL component consists of a proton-conducting, methanolimpermeable poly(diallyl dimethyl ammonium chloride)/sulfonated poly(2,6-dimethyl 1,4-phenylene oxide) (PDAC/sPPO) thin film. The electrospun fiber component consists of PA 6(3)T fibers of average diameter between 400 and 800 nm, in a nonwoven matrix of 60-90% porosity depending on the temperature of thermal annealing utilized to improve the mechanical properties. This thesis demonstrates the versatility and flexibility of this fabrication technique, since any ion conducting LbL system may be sprayed onto any electrospun fiber mat, allowing for independent control of functionality and mechanical properties. The mechanical properties of the spray coated electrospun mats are shown to be superior to the LbL-only system, and possess intrinsically greater dimensional stability and lower mechanical hysteresis than Nafion under hydration cycling. The electrochemical selectivity of the composite LbL-electrospun membrane is found to be superior to Nafion, which makes them a viable alternative proton exchange membrane for fuel cell applications. The composite proton exchange membranes fabricated in this work were tested in an operational direct methanol fuel cell, with results showing the capability for higher open circuit voltages (OCV) and comparable cell resistances when compared to Nafion. (Copies available exclusively from MIT Libraries, libraries.mit.edu/docs - docs@mit.edu)

[Characterization of Black and Dichothrix Cyanobacteria Based on the 16S Ribosomal RNA Gene Sequence

NASA Technical Reports Server (NTRS)

Ortega, Maya

2010-01-01

My project focuses on characterizing different cyanobacteria in thrombolitic mats found on the island of Highborn Cay, Bahamas. Thrombolites are interesting ecosystems because of the ability of bacteria in these mats to remove carbon dioxide from the atmosphere and mineralize it as calcium carbonate. In the future they may be used as models to develop carbon sequestration technologies, which could be used as part of regenerative life systems in space. These thrombolitic communities are also significant because of their similarities to early communities of life on Earth. I targeted two cyanobacteria in my research, Dichothrix spp. and whatever black is, since they are believed to be important to carbon sequestration in these thrombolitic mats. The goal of my summer research project was to molecularly identify these two cyanobacteria. DNA was isolated from each organism through mat dissections and DNA extractions. I ran Polymerase Chain Reactions (PCR) to amplify the 16S ribosomal RNA (rRNA) gene in each cyanobacteria. This specific gene is found in almost all bacteria and is highly conserved, meaning any changes in the sequence are most likely due to evolution. As a result, the 16S rRNA gene can be used for bacterial identification of different species based on the sequence of their 16S rRNA gene. Since the exact sequence of the Dichothrix gene was unknown, I designed different primers that flanked the gene based on the known sequences from other taxonomically similar cyanobacteria. Once the 16S rRNA gene was amplified, I cloned the gene into specialized Escherichia coli cells and sent the gene products for sequencing. Once the sequence is obtained, it will be added to a genetic database for future reference to and classification of other Dichothrix sp.

Distribution and Composition of Thiotrophic Mats in the Hypoxic Zone of the Black Sea (150–170 m Water Depth, Crimea Margin)

PubMed Central

Jessen, Gerdhard L.; Lichtschlag, Anna; Struck, Ulrich; Boetius, Antje

2016-01-01

At the Black Sea chemocline, oxygen- and sulfide-rich waters meet and form a niche for thiotrophic pelagic bacteria. Here we investigated an area of the Northwestern Black Sea off Crimea close to the shelf break, where the chemocline reaches the seafloor at around 150–170 m water depth, to assess whether thiotrophic bacteria are favored in this zone. Seafloor video transects were carried out with the submersible JAGO covering 20 km2 on the region between 110 and 200 m depth. Around the chemocline we observed irregular seafloor depressions, covered with whitish mats of large filamentous bacteria. These comprised 25–55% of the seafloor, forming a belt of 3 km width around the chemocline. Cores from the mats obtained with JAGO showed higher accumulations of organic matter under the mats compared to mat-free sediments. The mat-forming bacteria were related to Beggiatoa-like large filamentous sulfur bacteria based on 16S rRNA sequences from the mat, and visual characteristics. The microbial community under the mats was significantly different from the surrounding sediments and enriched with taxa affiliated with polymer degrading, fermenting and sulfate reducing microorganisms. Under the mats, higher organic matter accumulation, as well as higher remineralization and radiotracer-based sulfate reduction rates were measured compared to outside the mat. Mat-covered and mat-free sediments showed similar degradability of the bulk organic matter pool, suggesting that the higher sulfide fluxes and subsequent development of the thiotrophic mats in the patches are consequences of the accumulation of organic matter rather than its qualitative composition. Our observations suggest that the key factors for the distribution of thiotrophic mat-forming communities near to the Crimean shelf break are hypoxic conditions that (i) repress grazers, (ii) enhance the accumulation and degradation of labile organic matter by sulfate-reducers, and (iii) favor thiotrophic filamentous bacteria which are adapted to exploit steep gradients in oxygen and sulfide availability; in addition to a specific seafloor topography which may relate to internal waves at the shelf break. PMID:27446049

Seronegativity of bovines face to their own recovered leptospiral isolates.

PubMed

Libonati, Hugo; Pinto, Priscila S; Lilenbaum, Walter

2017-07-01

Leptospirosis is an important cause of reproductive failure in cattle. The standard diagnostic tool (MAT) is recommended for herd but not for individual diagnosis. The aim of this study was to evaluate the humoral response of bovines face to their own recovered isolates. A total of 25 bovine from which leptospires were recovered were tested by MAT against reference strains and their own isolates. Only three cows (12%) presented seroreactivity against their own isolates. This study demonstrates that cattle may not react against their own isolates and highlights the importance of interpreting serological negative results with caution. Copyright © 2017 Elsevier Ltd. All rights reserved.

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.

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

Development Challenges of Game-Changing Entry System Technologies From Concept to Mission Infusion

NASA Technical Reports Server (NTRS)

Venkatapathy, Ethiraj; Beck, Robin; Ellerby, Don; Feldman, Jay; Gage, Peter; Munk, Michelle; Wercinski, Paul

2016-01-01

Realization within the US and NASA that future exploration both Human and Robotic will require innovative new technologies led to the creation of the Space Technology Mission Directorate and investment in game changing technologies with high pay-off. Some of these investments will see success and others, due to many of the constraints, will not attain their goal. The co-authors of this proposed presentation have been involved from concept to mission infusion aspects of entry technologies that are game changing. The four example technologies used to describe the challenges experienced along the pathways to success are at different levels of maturity. They are Conformal, 3-D MAT, HEEET and ADEPT. The four examples in many ways capture broad aspects of the challenges of maturation and illustrate what led some to be exceptionally successful and how others had to be altered in order remain viable game changing technologies.

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.

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.

Report of Defense Science Board Task Force on Industry-to-Industry International Armaments Cooperation. Phase II. Japan

DTIC Science & Technology

1984-06-01

TEMPERATURE MAT’LS IMAGE RECOGNITION ROCKET PROPULSION SPEECH RECOGNITION/TRANSLATION COMPUTER-AIDED DESIGN ARTIFICIAL INTELLIGENCE PRODUCTION TECHNOLOGY...planning, intelligence exchange, and logistics. While not called out in the Guidelines, any further standardization in equipments and interoperability...COST AND TIME THAN DEVELCPING THEM -ESTABLISHMENT OF PRODUCTIVE LONG-TERM BUSINESS RELATIONSH IPS WITH JAPANESE COMPAN IES * PROBLEM -POSSIBILITY OF

JPRS Report, Science & Technology, Europe, Economic Competitiveness

DTIC Science & Technology

1991-04-25

business), and entertainment electronics com- panies such as Sony , Pioneer, JVC, Hitachi and Mat- sushita ("National Panasonic") in particular are...of outsiders from Southeast Asia, who are making life miser- able for the already too numerous big producers, such as BASF, Sony , TDK, Maxell, FDM...Motor, Mitsubishi Motor, and Yamaha Motor (motorcycles, alongside its parent com- pany Yamaha Corporation, which is also in the musical instrument

Phylogenetic Analysis of Nuclear-Encoded RNA Maturases

PubMed Central

Malik, Sunita; Upadhyaya, KC; Khurana, SM Paul

2017-01-01

Posttranscriptional processes, such as splicing, play a crucial role in gene expression and are prevalent not only in nuclear genes but also in plant mitochondria where splicing of group II introns is catalyzed by a class of proteins termed maturases. In plant mitochondria, there are 22 mitochondrial group II introns. matR, nMAT1, nMAT2, nMAT3, and nMAT4 proteins have been shown to be required for efficient splicing of several group II introns in Arabidopsis thaliana. Nuclear maturases (nMATs) are necessary for splicing of mitochondrial genes, leading to normal oxidative phosphorylation. Sequence analysis through phylogenetic tree (including bootstrapping) revealed high homology with maturase sequences of A thaliana and other plants. This study shows the phylogenetic relationship of nMAT proteins between A thaliana and other nonredundant plant species taken from BLASTP analysis. PMID:28607538

Préface

NASA Astrophysics Data System (ADS)

Mazière, D.

2002-04-01

Faisant suite aux deux précédents colloques "Matériaux pour les machines thermiques" et "Matériaux pour le nucléaire" , le colloque 2001 de l'INSTN intitulé "Matériaux pour les énergies propres" s'est focalisé sur les problèmes de matériaux encore à résoudre dans ce secteur industriel. Le colloque de métallurgie est traditionnellement organisé par des ense ignants du DEA Métallurgie et Matériaux et un comité scientifique choisi chaq ue année en liaison avec le thème traité. Les étudiants de ce DEA, qui est hab ilité entre Paris XI, Paris VI, l'Ecole des Mines de Paris, l'Ecole Centrale de Pari s et l'INSTN, sont invités à participer à ce colloque et aux débats scientifiques qui s'y déroulent. Des conférences invitées à caractère péda gogique permettent d'introduire les différents thèmes abordés qui sont ensuite développés dans des présentations plus novatrices. Cette manifestation a pour ambition de favoriser la rencontre de scientifiques d'horizons divers venant de milieux académiques ou industriels entre eux et avec les étudiants et thésards. Cette 44e édition, dont les comptes rendus sont publiés ici, a fait le point sur les problèmes de matériaux rencontrés lors de la production, du stockage et de la conversion des énergies dites propres en englobant lesprogrès constants des industriels de l'automobile. Ce colloque a réuni, du 26 au 28 juin 2001, 63 participants provenant d'universités ou grandes écoles (18), du CEA (17), du CNRS (10) et de l'industrie ou de centres de recherche associés. L'ensemble des problèmes de matériaux de ce secteur ont été examinés au cours des six sessions ci-dessous : dépollution des gaz d'échappement ; combustion catalytique en production thermique ; nouvelles batteries ; piles à combustibles ; production et stockage d'hydrogène ; production et stockage d'énergie solaire. Vingt huit communications dont vingt deux orales ont illustré les dével oppements en cours. Dix-sept d'entre elles sont développées dans cet ouvrage. On pourra consulter avec profit le numéro 44 des Clefs CEA "Nouvelles Technologies de l'énergie" en complément du présent ouvrage.

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.

Earth's Earliest Ecosystems in the C: The Use of Microbial Mats to Demonstrate General Principles of Scientific Inquiry and Microbial Ecology

NASA Technical Reports Server (NTRS)

Bebout, Brad M.; Bucaria, Robin

2006-01-01

Microbial mats are living examples of the most ancient biological communities on Earth. As Earth's earliest ecosystems, they are centrally important to understanding the history of life on our planet and are useful models for the search for life elsewhere. As relatively compact (but complete) ecosystems, microbial mats are also extremely useful for educational activities. Mats may be used to demonstrate a wide variety of concepts in general and microbial ecology, including the biogeochemical cycling of elements, photosynthesis and respiration, and the origin of the Earth's present oxygen containing atmosphere. Microbial mats can be found in a number of common environments accessible to teachers, and laboratory microbial mats can be constructed using materials purchased from biological supply houses. With funding from NASA's Exobiology program, we have developed curriculum and web-based activities centered on the use of microbial mats as tools for demonstrating general principles in ecology, and the scientific process. Our web site (http://microbes.arc.nasa.gov) includes reference materials, lesson plans, and a "Web Lab", featuring living mats maintained in a mini-aquarium. The site also provides information as to how research on microbial mats supports NASA's goals, and various NASA missions. A photo gallery contains images of mats, microscopic views of the organisms that form them, and our own research activities. An animated educational video on the web site uses computer graphic and video microscopy to take students on a journey into a microbial mat. These activities are targeted to a middle school audience and are aligned with the National Science Standards.

Cyanobacterial construction of hot spring siliceous stromatolites in Yellowstone National Park.

PubMed

Pepe-Ranney, Charles; Berelson, William M; Corsetti, Frank A; Treants, Merika; Spear, John R

2012-05-01

Living stromatolites growing in a hot spring in Yellowstone National Park are composed of silica-encrusted cyanobacterial mats. Two cyanobacterial mat types grow on the stromatolite surfaces and are preserved as two distinct lithofacies. One mat is present when the stromatolites are submerged or at the water-atmosphere interface and the other when stromatolites protrude from the hot spring. The lithofacies created by the encrustation of submerged mats constitutes the bulk of the stromatolites, is comprised of silica-encrusted filaments, and is distinctly laminated. To better understand the cyanobacterial membership and community structure differences between the mats, we collected mat samples from each type. Molecular methods revealed that submerged mat cyanobacteria were predominantly one novel phylotype while the exposed mats were predominantly heterocystous phylotypes (Chlorogloeopsis HTF and Fischerella). The cyanobacterium dominating the submerged mat type does not belong in any of the subphylum groups of cyanobacteria recognized by the Ribosomal Database Project and has also been found in association with travertine stromatolites in a Southwest Japan hot spring. Cyanobacterial membership profiles indicate that the heterocystous phylotypes are 'rare biosphere' members of the submerged mats. The heterocystous phylotypes likely emerge when the water level of the hot spring drops. Environmental pressures tied to water level such as sulfide exposure and possibly oxygen tension may inhibit the heterocystous types in submerged mats. These living stromatolites are finely laminated and therefore, in texture, may better represent similarly laminated ancient forms compared with more coarsely laminated living marine examples. © 2012 Society for Applied Microbiology and Blackwell Publishing Ltd.

Detection of pathogenic Leptospira from selected environment in Kelantan and Terengganu, Malaysia.

PubMed

Ridzlan, F R; Bahaman, A R; Khairani-Bejo, S; Mutalib, A R

2010-12-01

Leptospirosis is recognized as one of the important zoonotic diseases in the world including Malaysia. A total of 145 soil and water samples were collected from selected National Service Training Centres (NSTC) in Kelantan and Terengganu. The samples were inoculated into modified semisolid Ellinghausen McCullough Johnson Harris (EMJH) medium, incubated at room temperature for 1 month and examined under the dark-field microscope. Positive growth of the leptospiral isolates were then confirmed with 8-Azaguanine Test, Polymerase Chain Reaction (PCR) assay and Microscopic Agglutination Test (MAT). Fifteen cultures (10.34%) exhibited positive growths which were seen under dark field microscope whilst only 20% (3/15) were confirmed as pathogenic species. based on 8-Azaguanine Test and PCR. Serological identification of the isolates with MAT showed that hebdomadis was the dominant serovar in Terengganu. Pathogenic leptospires can be detected in Malaysian environment and this has the potential to cause an outbreak. Therefore, precautionary steps against leptospirosis should be taken by camp authorities to ensure the safety of trainees.

AM2 Mat End Connector Modeling and Performance Validation

DTIC Science & Technology

2015-08-01

9 3.2.1 Subgrade construction and posttest forensics...layout. 3.2.1 Subgrade construction and posttest forensics The test section subgrade was built using in-place material from a previous AM2 test...area 50 ft wide by 42 ft long of the existing test bed was removed and replaced with newly processed material. Posttest values from the previous

Leptospirosis Outbreak following Severe Flooding: A Rapid Assessment and Mass Prophylaxis Campaign; Guyana, January–February 2005

PubMed Central

Dechet, Amy M.; Parsons, Michele; Rambaran, Madan; Mohamed-Rambaran, Pheona; Florendo-Cumbermack, Anita; Persaud, Shamdeo; Baboolal, Shirematee; Ari, Mary D.; Shadomy, Sean V.; Zaki, Sherif R.; Paddock, Christopher D.; Clark, Thomas A.; Harris, Lazenia; Lyon, Douglas; Mintz, Eric D.

2012-01-01

Background Leptospirosis is a zoonosis usually transmitted through contact with water or soil contaminated with urine from infected animals. Severe flooding can put individuals at greater risk for contracting leptospirosis in endemic areas. Rapid testing for the disease and large-scale interventions are necessary to identify and control infection. We describe a leptospirosis outbreak following severe flooding and a mass chemoprophylaxis campaign in Guyana. Methodology/Principal Findings From January–March 2005, we collected data on suspected leptospirosis hospitalizations and deaths. Laboratory testing included anti-leptospiral dot enzyme immunoassay (DST), immunohistochemistry (IHC) staining, and microscopic agglutination testing (MAT). DST testing was conducted for 105 (44%) of 236 patients; 52 (50%) tested positive. Four (57%) paired serum samples tested by MAT were confirmed leptospirosis. Of 34 total deaths attributed to leptospirosis, postmortem samples from 10 (83%) of 12 patients were positive by IHC. Of 201 patients interviewed, 89% reported direct contact with flood waters. A 3-week doxycycline chemoprophylaxis campaign reached over 280,000 people. Conclusions A confirmed leptospirosis outbreak in Guyana occurred after severe flooding, resulting in a massive chemoprophylaxis campaign to try to limit morbidity and mortality. PMID:22808049

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...

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.

Validity of Hip-worn Inertial Measurement Unit Compared to Jump Mat for Jump Height Measurement in Adolescents.

PubMed

Rantalainen, T; Hesketh, K D; Rodda, C; Duckham, R L

2018-06-16

Jump tests assess lower body power production capacity, and can be used to evaluate athletic ability and development during growth. Wearable inertial measurement units (IMU) seem to offer a feasible alternative to laboratory-based equipment for jump height assessments. Concurrent validity of these devices for jump height assessments has only been established in adults. Therefore, the purpose of this study was to evaluate the concurrent validity of IMU-based jump height estimate compared to contact mat-based jump height estimate in adolescents. Ninety-five adolescents (10-13 years-of-age; girls N=41, height = 154 (SD 9) cm, weight = 44 (11) kg; boys N=54, height=156 (10) cm, weight = 46 (13) kg) completed three counter-movement jumps for maximal jump height on a contact mat. Inertial recordings (accelerations, rotations) were concurrently recorded with a hip-worn IMU (sampling at 256 Hz). Jump height was evaluated based on flight time. The mean IMU-derived jump height was 27.1 (SD 3.8) cm, and the corresponding mean jump-mat-derived value was 21.5 (3.4) cm. While a significant 26% mean difference was observed between the methods (5.5 [95% limits of agreement 2.2 to 8.9] cm, p = 0.006), the correspondence between methods was excellent (ICC = 0.89). The difference between methods was weakly positively associated with jump height (r = 0.28, P = 0.007). Take-off velocity derived jump height was also explored but produced only fair congruence. In conclusion, IMU-derived jump height exhibited excellent congruence to contact mat-based jump height and therefore presents a feasible alternative for jump height assessments in adolescents. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

Élaboration et performances de matériaux supraconducteurs {YBa_2Cu_3O_7} massifs texturés de taille croissante

NASA Astrophysics Data System (ADS)

Chaud, X.; Gautier-Picard, P.; Beaugnon, E.; Porcar, L.; Bourgault, D.; Tournier, R.; Erraud, A.; Tixador, P.

1998-03-01

Industrial applications of the bulk superconducting YBa_2Cu_3O_7 material imply to control the growth of large oriented monodomains in samples of big size (several centimeters). The laboratory EPM-Matformag is committed to produce such materials according to three different methods (zone melting, solidification controlled by a magnetic field, crystal growth from a seed). The results obtained show that it is possible by such methods to elaborate a material with high performances at the centimeter scale and to produce it in series. The availability of such materials allows the measure of physical properties on a large scale and the testing of prototypes for cryo-electrotechnical applications (magnetic bearing, flywheel, coupling device, current lead...). Les applications industrielles des matériaux supraconducteurs massifs YBa_2Cu_3O_7 impliquent de contrôler la croissance de larges monodomaines orientés dans des échantillons de grande taille (plusieurs centimètres). Le laboratoire EPM-Matformag s'est appliqué à produire de tels matériaux selon trois techniques différentes (fusion de zone, solidification contrôlée sous champ magnétique, croissance cristalline à partir d'un germe). Les résultats obtenus montrent qu'il est possible par de telles techniques d'obtenir un matériau performant à l'échelle des centimètres et de le produire en série. La disponibilité de tels matériaux permet de mesurer des propriétés physiques à grande échelle et de tester des prototypes d'applications cryo-électrotechniques (palier magnétique, volant d'inertie, coupleur, amenée de courant, limiteur de courant...).

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.

The Inside Information about Safety Surfacing.

ERIC Educational Resources Information Center

Thompson, Donna; Hudson, Susan

2003-01-01

Tested the impact attenuation characteristics of safety surfaces used in indoor child care play settings. Found that the most common surfaces used were indoor/outdoor carpet, various types of mats, and safety floor tiles. Nearly 60 percent of tested materials had a critical fall height of 1 foot or less. Concluded that carpet, safety tile, and…

HiRadMat at CERN SPS - A test facility with high intensity beam pulses to material samples

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

Charitonidis, N.; Fabich, A.; Efthymiopoulos, I.

2015-07-01

HiRadMat (High Irradiation to Materials) is a facility at CERN designed to provide high-intensity pulsed beams to an irradiation area where material samples as well as accelerator component assemblies (e.g. vacuum windows, shock tests on high power targets, collimators) can be tested. The beam parameters (SPS 440 GeV protons with a pulse energy of up to 3.4 MJ, or alternatively lead/argon ions at the proton equivalent energy) can be tuned to match the needs of each experiment. It is a test area designed to perform single pulse experiments to evaluate the effect of high-intensity pulsed beams on materials in amore » dedicated environment, excluding long-time irradiation studies. The facility is designed for a 10{sup 16} maximum number of protons per year, in order to limit the activation to acceptable levels for human intervention. This paper will demonstrate the possibilities for research using this facility and showing examples of upcoming experiments scheduled in the beam period 2014/2015. (authors)« less

Magnetoacoustic Tomography with Magnetic Induction for Electrical Conductivity based Tissue imaging

NASA Astrophysics Data System (ADS)

Mariappan, Leo

Electrical conductivity imaging of biological tissue has attracted considerable interest in recent years owing to research indicating that electrical properties, especially electrical conductivity and permittivity, are indicators of underlying physiological and pathological conditions in biological tissue. Also, the knowledge of electrical conductivity of biological tissue is of interest to researchers conducting electromagnetic source imaging and in design of devices that apply electromagnetic energy to the body such as MRI. So, the need for a non-invasive, high resolution impedance imaging method is highly desired. To address this need we have studied the magnetoacoustic tomography with magnetic induction (MAT-MI) method. In MAT-MI, the object is placed in a static and a dynamic magnetic field giving rise to ultrasound waves. The dynamic field induces eddy currents in the object, and the static field leads to generation of acoustic vibrations from Lorentz force on the induced currents. The acoustic vibrations are at the same frequency as the dynamic magnetic field, which is chosen to match the ultrasound frequency range. These ultrasound signals can be measured by ultrasound probes and are used to reconstruct MAT-MI acoustic source images using possible ultrasound imaging approaches .The reconstructed high spatial resolution image is indicative of the object's electrical conductivity contrast. We have investigated ultrasound imaging methods to reliably reconstruct the MAT-MI image under the practical conditions of limited bandwidth and transducer geometry. The corresponding imaging algorithm, computer simulation and experiments are developed to test the feasibility of these different methods. Also, in experiments, we have developed a system with the strong static field of an MRI magnet and a strong pulsed magnetic field to evaluate MAT-MI in biological tissue imaging. It can be seen from these simulations and experiments that conductivity boundary images with millimeter resolution can be reliably reconstructed with MAT-MI. Further, to estimate the conductivity distribution throughout the object, we reconstruct a vector source image corresponding to the induced eddy currents. As the current source is uniformly present throughout the object, we are able to reliably estimate the internal conductivity distribution for a more complete imaging. From the computer simulations and experiments it can be seen that MAT-MI method has the potential to be a clinically applicable, high resolution, non-invasive method for electrical conductivity imaging.

tweezercalib 2.0: Faster version of MatLab package for precise calibration of optical tweezers

NASA Astrophysics Data System (ADS)

Hansen, Poul Martin; Tolić-Nørrelykke, Iva Marija; Flyvbjerg, Henrik; Berg-Sørensen, Kirstine

2006-03-01

We present a vectorized version of the MatLab (MathWorks Inc.) package tweezercalib for calibration of optical tweezers with precision. The calibration is based on the power spectrum of the Brownian motion of a dielectric bead trapped in the tweezers. Precision is achieved by accounting for a number of factors that affect this power spectrum, as described in vs. 1 of the package [I.M. Tolić-Nørrelykke, K. Berg-Sørensen, H. Flyvbjerg, Matlab program for precision calibration of optical tweezers, Comput. Phys. Comm. 159 (2004) 225-240]. The graphical user interface allows the user to include or leave out each of these factors. Several "health tests" are applied to the experimental data during calibration, and test results are displayed graphically. Thus, the user can easily see whether the data comply with the theory used for their interpretation. Final calibration results are given with statistical errors and covariance matrix. New version program summaryTitle of program: tweezercalib Catalogue identifier: ADTV_v2_0 Program summary URL:http://cpc.cs.qub.ac.uk/summaries/ADTV_v2_0 Program obtainable from: CPC Program Library, Queen's University of Belfast, N. Ireland Reference in CPC to previous version: I.M. Tolić-Nørrelykke, K. Berg-Sørensen, H. Flyvbjerg, Comput. Phys. Comm. 159 (2004) 225 Catalogue identifier of previous version: ADTV Does the new version supersede the original program: Yes Computer for which the program is designed and others on which it has been tested: General computer running MatLab (Mathworks Inc.) Operating systems under with the program has been tested: Windows2000, Windows-XP, Linux Programming language used: MatLab (Mathworks Inc.), standard license Memory required to execute with typical data: Of order four times the size of the data file High speed storage required: none No. of lines in distributed program, including test data, etc.: 135 989 No. of bytes in distributed program, including test data, etc.: 1 527 611 Distribution format: tar. gz Nature of physical problem: Calibrate optical tweezers with precision by fitting theory to experimental power spectrum of position of bead doing Brownian motion in incompressible fluid, possibly near microscope cover slip, while trapped in optical tweezers. Thereby determine spring constant of optical trap and conversion factor for arbitrary-units-to-nanometers for detection system. Method of solution: Elimination of cross-talk between quadrant photo-diode's output channels for positions (optional). Check that distribution of recorded positions agrees with Boltzmann distribution of bead in harmonic trap. Data compression and noise reduction by blocking method applied to power spectrum. Full accounting for hydrodynamic effects: Frequency-dependent drag force and interaction with nearby cover slip (optional). Full accounting for electronic filters (optional), for "virtual filtering" caused by detection system (optional). Full accounting for aliasing caused by finite sampling rate (optional). Standard non-linear least-squares fitting. Statistical support for fit is given, with several plots facilitating inspection of consistency and quality of data and fit. Summary of revisions: A faster fitting routine, adapted from [J. Nocedal, Y.x. Yuan, Combining trust region and line search techniques, Technical Report OTC 98/04, Optimization Technology Center, 1998; W.H. Press, B.P. Flannery, S.A. Teukolsky, W.T. Vetterling, Numerical Recipes. The Art of Scientific Computing, Cambridge University Press, Cambridge, 1986], is applied. It uses fewer function evaluations, and the remaining function evaluations have been vectorized. Calls to routines in Toolboxes not included with a standard MatLab license have been replaced by calls to routines that are included in the present package. Fitting parameters are rescaled to ensure that they are all of roughly the same size (of order 1) while being fitted. Generally, the program package has been updated to comply with MatLab, vs. 7.0, and optimized for speed. Restrictions on the complexity of the problem: Data should be positions of bead doing Brownian motion while held by optical tweezers. For high precision in final results, data should be time series measured over a long time, with sufficiently high experimental sampling rate: The sampling rate should be well above the characteristic frequency of the trap, the so-called corner frequency. Thus, the sampling frequency should typically be larger than 10 kHz. The Fast Fourier Transform used works optimally when the time series contain 2 data points, and long measurement time is obtained with n>12-15. Finally, the optics should be set to ensure a harmonic trapping potential in the range of positions visited by the bead. The fitting procedure checks for harmonic potential. Typical running time: Seconds Unusual features of the program: None References: The theoretical underpinnings for the procedure are found in [K. Berg-Sørensen, H. Flyvbjerg, Power spectrum analysis for optical tweezers, Rev. Sci. Ins. 75 (2004) 594-612].

Comparative functional ultrastructure of two hypersaline submerged cyanobacterial mats - Guerrero Negro, Baja California Sur, Mexico, and Solar Lake, Sinai, Egypt

NASA Technical Reports Server (NTRS)

D'Amelio, Elisa D'antoni; Des Marais, David J.; Cohen, Jehuda

1989-01-01

The ultrastructure of the submerged microbial mat from the Solar Lake (SL), Egypt, was compared to that of samples from the Guerrero Negro (GN), Mexico, salt pans. The locations and distributions of the main organisms were determined light microscopy, and the corresponding ultrathin sections were examined under TEM; chemical microprofile analyses were carried out on the day of sampling for microscopic studies. Both communities were found to be dominated by Microleus chthonoplastes, although several morphological species found in the GN mat were absent from the SL mat, including the Tropica nigra and the 'big' Microleus chthonoplastes component. The chemical microprofiles of oxygen, sulfide, pH, and the oxygenic photosynthesis in the two mats were virtually identical. In both mats, the photic zone was restricted to the upper 800 microns of the mat, and oxygenic photosynthesis was detected down to 600 microns.

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.

Functional electrospun nanofibers for multimodal sensitive detection of biogenic amines in food via a simple dipstick assay.

PubMed

Yurova, Nadezhda S; Danchuk, Alexandra; Mobarez, Sarah N; Wongkaew, Nongnoot; Rusanova, Tatiana; Baeumner, Antje J; Duerkop, Axel

2018-01-01

Electrospun nanofibers (ENFs) are promising materials for rapid diagnostic tests like lateral flow assays and dipsticks because they offer an immense surface area while excluding minimal volume, a variety of functional surface groups, and can entrap functional additives within their interior. Here, we show that ENFs on sample pads are superior in comparison to standard polymer membranes for the optical detection of biogenic amines (BAs) in food using a dipstick format. Specifically, cellulose acetate (CA) fibers doped with 2 mg/mL of the chromogenic and fluorogenic amine-reactive chameleon dye Py-1 were electrospun into uniform anionic mats. Those extract cationic BAs from real samples and Py-1 transduces BA concentrations into a change of color, reflectance, and fluorescence. Dropping a BA sample onto the nanofiber mat converts the weakly fluorescent pyrylium dye Py-1 into a strongly red emitting pyridinium dye. For the first time, a simple UV lamp excites fluorescence and a digital camera acts as detector. The intensity ratio of the red to the blue channel of the digital image is dependent on the concentration of most relevant BAs indicating food spoilage from 10 to 250 μM. This matches the permitted limits for BAs in foods and no false positive signals arise from secondary and tertiary amines. BA detection in seafood samples was also demonstrated successfully. The nanofiber mat dipsticks were up to sixfold more sensitive than those using a polymer membrane with the same dye embedded. Hence, nanofiber-based tests are not only superior to polymer-based dipstick assays, but will also improve the performance of established tests related to food safety, medical diagnostics, and environmental testing. Graphical Absract ᅟ.

49 CFR 393.122 - What are the rules for securing paper rolls?

Code of Federal Regulations, 2014 CFR

2014-10-01

... prevented by filling the void, blocking, bracing, tiedowns or friction mats. The paper rolls may also be... vehicle, exceeds the diameter of the paper rolls, rearward movement must be prevented by friction mats... less than 1.75 times its diameter, and it is restrained against forward movement by friction mat(s...

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.

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.

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.

The green alga, Cladophora, promotes Escherichia coli growth and contamination of recreational waters in Lake Michigan.

PubMed

Vanden Heuvel, Amy; McDermott, Colleen; Pillsbury, Robert; Sandrin, Todd; Kinzelman, Julie; Ferguson, John; Sadowsky, Michael; Byappanahalli, Muruleedhara; Whitman, Richard; Kleinheinz, Gregory T

2010-01-01

A linkage between Cladophora mats and exceedances of recreational water quality criteria has been suggested, but not directly studied. This study investigates the spatial and temporal association between Escherichia coli concentrations within and near Cladophora mats at two northwestern Lake Michigan beaches in Door County, Wisconsin. Escherichia coli concentrations in water underlying mats were significantly greater than surrounding water (p < 0.001). Below mat E. coli increased as the stranded mats persisted at the beach swash zone. Water adjacent to Cladophora mats had lower E. coli concentrations, but surpassed EPA swimming criteria the majority of sampling days. A significant positive association was found between E. coli concentrations attached to Cladophora and in underlying water (p < 0.001). The attached E. coli likely acted as a reservoir for populating water underlying the mat. Fecal bacterial pathogens, however, could not be detected by microbiological culture methods either attached to mat biomass or in underlying water. Removal of Cladophora mats from beach areas may improve aesthetic and microbial water quality at affected beaches. These associations and potential natural growth of E. coli in bathing waters call into question the efficacy of using E. coli as a recreational water quality indicator of fecal contaminations.

Long Term Manipulations of Intact Microbial Mat Communities in a Greenhouse Collaboratory: Simulating Earth's Present and Past Field Environments

NASA Technical Reports Server (NTRS)

Bebout, Brad; DesMarais, David J.; Discipulo, Mykell; Embaye, Tsegereda; Garcia-Pichel, Ferran; Hogan, Mary; Jahnke, Linda L.; Keller, Richard M.; Miller, Scott R.; Prufert-Bebout, Leslie E.;

Long-Term Manipulations of Intact Microbial Mat Communities in a Greenhouse Collaboratory: Simulating Earth's Present and Past Field Environments

NASA Astrophysics Data System (ADS)

Bebout, Brad M.; Carpenter, Steven P.; Des Marais, David J.; Discipulo, Mykell; Embaye, Tsegereda; Garcia-Pichel, Ferran; Hoehler, Tori M.; Hogan, Mary; Jahnke, Linda L.; Keller, Richard M.; Miller, Scott R.; Prufert-Bebout, Leslie E.; Raleigh, Chris; Rothrock, Michael; Turk, Kendra

2002-12-01

Photosynthetic microbial mat communities were obtained from marine hypersaline saltern ponds, maintained in a greenhouse facility, and examined for the effects of salinity variations. Because these microbial mats are considered to be useful analogs of ancient marine communities, they offer insights about evolutionary events during the >3 billion year time interval wherein mats co-evolved with Earth's lithosphere and atmosphere. Although photosynthetic mats can be highly dynamic and exhibit extremely high activity, the mats in the present study have been maintained for >1 year with relatively minor changes. The major groups of microorganisms, as assayed using microscopic, genetic, and biomarker methodologies, are essentially the same as those in the original field samples. Field and greenhouse mats were similar with respect to rates of exchange of oxygen and dissolved inorganic carbon across the mat-water interface, both during the day and at night. Field and greenhouse mats exhibited similar rates of efflux of methane and hydrogen. Manipulations of salinity in the water overlying the mats produced changes in the community that strongly resemble those observed in the field. A collaboratory testbed and an array of automated features are being developed to support remote scientific experimentation with the assistance of intelligent software agents. This facility will permit teams of investigators the opportunity to explore ancient environmental conditions that are rare or absent today but that might have influenced the early evolution of these photosynthetic ecosystems.

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

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

Fabrication of a novel scaffold of clotrimazole-microemulsion-containing nanofibers using an electrospinning process for oral candidiasis applications.

PubMed

Tonglairoum, Prasopchai; Ngawhirunpat, Tanasait; Rojanarata, Theerasak; Kaomongkolgit, Ruchadaporn; Opanasopit, Praneet

2015-02-01

Clotrimazole (CZ)-loaded microemulsion-containing nanofiber mats were developed as an alternative for oral candidiasis applications. The microemulsion was composed of oleic acid (O), Tween 80 (T80), and a co-surfactant such as benzyl alcohol (BzOH), ethyl alcohol (EtOH) or isopropyl alcohol (IPA). The nanofiber mats were obtained by electrospinning a blended solution of a CZ-loaded microemulsion and a mixed polymer solution of 2% (w/v) chitosan (CS) and 10% (w/v) polyvinyl alcohol (PVA) at a weight ratio of 30:70. The nanofiber mats were characterized using various analytical techniques. The entrapment efficiency, drug release, antifungal activity and cytotoxicity were investigated. The average diameter of the nanofiber mats was in the range of 105.91-125.56 nm. The differential scanning calorimetry (DSC) and powder X-ray diffractometry (PXRD) results revealed the amorphous state of the CZ-loaded microemulsions incorporated into the nanofiber mats. The entrapment efficiency of CZ in the mats was approximately 72.58-98.10%, depended on the microemulsion formulation. The release experiment demonstrated different CZ release characteristics from nanofiber mats prepared using different CZ-loaded microemulsions. The extent of drug release from the fiber mats at 4h was approximately 64.81-74.15%. The release kinetics appeared to follow Higuchi's model. In comparison with CZ lozenges (10mg), the nanofiber mats exhibited more rapid killing activity. Moreover, the nanofiber mats demonstrated desirable mucoadhesive properties and were safe for 2h. Therefore, the nanofiber mats have the potential to be promising candidates for oral candidiasis applications. Copyright © 2014 Elsevier B.V. All rights reserved.

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 basis for the understanding of the distribution patterns of these compounds in more complex aquatic environments.

Effect of natural fiber types and sodium silicate coated on natural fiber mat/PLA composites: Tensile properties and rate of fire propagation

NASA Astrophysics Data System (ADS)

Thongpin, C.; Srimuk, J.; hipkam, N.; Wachirapong, P.

2015-07-01

In this study, 3 types of natural fibres, i.e. jute, sisal and abaca, were plain weaved to fibre mat. Before weaving, the fibres were treated with 5% NaOH to remove hemi cellulose and lignin. The weaving was performed by hand using square wooden block fit with nails for weaving using one and two types of natural fibres as weft and warp fibre to produce natural fibre mat. The fibre mat was also impregnated in sodium silicate solution extracted from rich husk ash. The pH of the solution was adjusted to pH 7 using H2SO4 before impregnation. After predetermined time, sodium silicate was gelled and deposited on the mat. The fabric mat and sodium silicate coated mat were then impregnated with PLA solution to produce prepreg. Dried pepreg was laminated with PLA sheet using compressing moulding machine to obtain natural fibre mat/PLA composite. The composite containing abaca aligned in longitudinal direction with respect to tension force enhanced Young's modulus more than 300%. Fibre mat composites with abaca aligned in longitudinal direction also showed tensile strength enhancement nearly 400% higher than neat PLA. After coating with sodium silicate, the tensile modulus of the composites was found slightly increased. The silicate coating was disadvantage on tensile strength of the composite due to the effect of sodium hydroxide solution that was used as solvent for silicate extraction from rice husk ash. However, sodium silicate could retard rate of fire propagation about 50%compare to neat PLA and about 10% reduction compared to fibre mat composites without sodium silicate coated fibre mat.

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.

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 physiology of the mats, as well as new insights into the biological processes associated with carbonate precipitation in modern marine stromatolites.

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 measurements provided ground truth for reduction of multispectral Landsat and Worldview-2 satellite images to evaluate mat distribution and diversity across a range of spatial and spectral facies variations.

Investigation of VEGGIE Root Mat

NASA Technical Reports Server (NTRS)

Subbiah, Arun M.

2013-01-01

VEGGIE is a plant growth facility that utilizes the phenomenon of capillary action as its primary watering system. A cloth made of Meta Aramid fiber, known as Nomex is used to wick water up from a reservoir to the bottom of the plants roots. This root mat system is intended to be low maintenance with no moving parts and requires minimal crew interface time. Unfortunately, the water wicking rates are inconsistent throughout the plant life cycle, thus causing plants to die. Over-wicking of water occurs toward the beginning of the cycle, while under-wicking occurs toward the middle. This inconsistency of wicking has become a major issue, drastically inhibiting plant growth. The primary objective is to determine the root cause of the inconsistent wicking through experimental testing. Suspect causes for the capillary water column to break include: a vacuum effect due to a negative pressure gradient in the water reservoir, contamination of material due to minerals in water and back wash from plant fertilizer, induced air bubbles while using syringe refill method, and material limitations of Nomex's ability to absorb and retain water. Experimental testing will be conducted to systematically determine the cause of under and over-wicking. Pressure gages will be used to determine pressure drop during the course of the plant life cycle and during the water refill process. A debubbler device will be connected to a root mat in order to equalize pressure inside the reservoir. Moisture and evaporation tests will simultaneously be implemented to observe moisture content and wicking rates over the course of a plant cycle. Water retention tests will be performed using strips of Nomex to determine materials wicking rates, porosity, and absorptivity. Through these experimental tests, we will have a better understanding of material properties of Nomex, as well as determine the root cause of water column breakage. With consistent test results, a forward plan can be achieved to resolve the issue and give valuable insight for the next generation of VEGGIE.

Outcomes of Osteochondral Allograft Transplantation With and Without Concomitant Meniscus Allograft Transplantation: A Comparative Matched Group Analysis.

PubMed

Frank, Rachel M; Lee, Simon; Cotter, Eric J; Hannon, Charles P; Leroux, Timothy; Cole, Brian J

2018-03-01

Osteochondral allograft transplantation (OCA) is often performed with concomitant meniscus allograft transplantation (MAT) as a strategy for knee joint preservation, although to date, the effect of concomitant MAT on outcomes and failure rates after OCA has not been assessed. To determine clinical outcomes for patients undergoing OCA with MAT as compared with a matched cohort of patients undergoing isolated OCA. Control study; Level of evidence, 3. Patients who underwent OCA of the medial or lateral femoral condyle without concomitant MAT by a single surgeon were compared with a matched group of patients who underwent OCA with concomitant MAT (ipsilateral compartment). The patients were matched per age, sex, body mass index, and number of previous ipsilateral knee operations ±1. Patient-reported outcomes, complications, reoperations, and survival rates were compared between groups. One hundred patients undergoing OCA (50 isolated, 50 with MAT) with a mean ± SD follow-up of 4.9 ± 2.7 years (minimum, 2 years) were included (age, 31.7 ± 9.8 years; 52% male). Significantly more patients underwent OCA to the medial femoral condyle (n = 59) than the lateral femoral condyle (n = 41, P < .0001). Patients underwent 2.7 ± 1.7 operations on the ipsilateral knee before OCA. There were no significant differences between the groups regarding reoperation rate (n = 18 for OCA with MAT, n = 17 for OCA without MAT, P = .834), time to reoperation (2.2 ± 2.4 years for OCA with MAT, 3.4 ± 2.7 years for OCA without MAT, P = .149), or failure rates (n = 7 [14%] for OCA with MAT, n = 7 [14%] for OCA without MAT, P > .999). There were no significant differences in patient-reported clinical outcome scores between the groups at final follow-up. There was no significant difference in failure rates between patients undergoing medial femoral condyle OCA (n = 12, 15.3%) and lateral femoral condyle OCA (n = 5, 12.2%, P = .665). These results imply that with appropriate surgical indications to address meniscus deficiency in patients otherwise indicated for OCA and despite the added surgical time and complexity of concomitant MAT, outcomes are favorable, with an 86% OCA graft survivorship at 5 years. This information can be used to counsel patients undergoing OCA with concomitant MAT as part of a knee joint preservation strategy.

Investigations of the mechanical properties of bi-layer and trilayer fiber reinforced composites

NASA Astrophysics Data System (ADS)

Jayakrishna, K.; Balasubramani, K.; Sultan, M. T. H.; Karthikeyan, S.

2016-10-01

Natural fibers are renewable raw materials with an environmental-friendly properties and they are recyclable. The mechanical properties of bi-layer and tri-layer thermoset polymer composites have been analyzed. The bi-layer composite consists of basalt and jute mats, while the tri-layer composite consists of basalt fiber, jute fiber and glass fiber mats. In both cases, the epoxy resin was used as the matrix and PTFE as a filler in the composites. The developed trilayer natural fiber composite can be used in various industrial applications such as automobile parts, construction and manufacturing. Furthermore, it also can be adopted in aircraft interior decoration and designed body parts. Flexural, impact, tensile, compression, shear and hardness tests, together with density measurement, were conducted to study the mechanical properties of both bi-layer and tri-layer composites. From the comparison, the tri-layer composite was found to perform in a better way in all tests.

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 biweekly basis. In addition to these parameter measurements already in place in current experiments, temperature and tidal cycle were monitored in the field. Over the course of the first three months, the microbial mat, which was submerged in an artificial seawater medium, grew vertically and developed a green surface at the top and sides. Thermogravimetric analysis has established that the top 1 mm surface mat biomass contains carbonate minerals, leading to an initial inferred carbonate mineralisation rate of approximately 0.5 g per 1 cm2 per year (approx. per 10 g surface mat material). This rate of mineralisation will become more accurate as more analysis is completed particularly comparing samples of mat, initially before they went in to the tank experiment and after incremental time periods, 3 months, 6 months etc. Further analysis of mat growth will establish the extent to which the precipitated carbonate minerals result from microbial activity and the types of minerals precipitated. The rate of mineralisation can be scaled-up to the km scale with the potential to isolate mineralisation rates promoted by different communities and in different types of microbial mat.

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...

Ultrafine polybenzimidazole (PBI) fibers. [separators for alkaline batteries and dfuel cells

NASA Technical Reports Server (NTRS)

Chenevey, E. C.

1979-01-01

Mats were made from ultrafine polybenzimidazole (PBI) fibers to provide an alternate to the use of asbestos as separators in fuel cells and alkaline batteries. To minimize distortion during mat drying, a process to provide a dry fibrid was developed. Two fibrid types were developed: one coarse, making mats for battery separators; the other fine, making low permeability matrices for fuel cells. Eventually, it was demonstrated that suitable mat fabrication techniques yielded fuel cell separators from the coarser alkaline battery fibrids. The stability of PBI mats to 45% KOH at 123 C can be increased by heat treatment at high temperatures. Weight loss data to 1000 hours exposure show the alkali resistance of the mats to be superior to that of asbestos.

The Use of the Miller Analogies Test as a Screening Device for Mexican-American Graduate Students.

ERIC Educational Resources Information Center

Duling, John A.

The determination of whether or not the Miller Analogies Test (MAT) is a valid screening device to use with a culturally diverse populace was examined. The study was conducted at New Mexico State University (NMSU) using 2 sample groups. Sample A consisted of 560 Anglos and 101 Mexican Americans tested by the NMSU Counseling Center during a 2-year…

[Effect of propriocetiv trainings tools for the muscles in stance stability].

PubMed

Dohm-Acker, M; Spitzenpfeil, P; Hartmann, U

2008-03-01

Today in each therapy and training program proprioceptive exercises are integrated. A lot of equipment you can buy. But for an more effective training exercises and equipment should be select more regarding the aim and the problem of the training. In literature is not much written about the specific way proprioction equipment stimulate different muscles. In this study 15 students of sport sciences (25.7 +/- 2.2 years, 8 male, 7 female) were tested for a period of 15 seconds in a single-leg standing position on a small rocker board, a wobble board, a gym mat and the Posturomed(c). The exercise was done just one time on each tool in a random way. The effect of the exercise was measured by EMG on six main stabilising muscles, m. tibialis ant., m. peroneus long., m. gastrocnemius med. And lat., m. semimembranosus and m. vastus med. At the end of the test series MVC of each muscle was tested. For the analysis we regarded the first, middle and last second of the test. Also the maximum peak over 0.5 sec. and the average of the whole test was integrated into the data base. The statistics was done with the Wilcoxen-Test. The experimental standard deviation was defined of 5 %. The highest EMG activity we noticed on the small rocker board. The activity was over the whole test series significant higher in the muscles m. tibialis ant., m. peroneus long. and m. gastrocnemius. The m. semimebranusus shows in all exercises the slightest EMG activity, the m. peroneus long. shows the highest activity. During the test all muscles decrease in EMG activity except m. peroneus long. on the small rocker board and the Posturomed. With these facts of EMG activity during proprioceptive exercises we are able to advice training more specifically: Because of the decreasing activity we advice doing repeated intervals not longer than 15 seconds. In the aim of ankle stabilisation use the small rocker board and the gym mat. For rehabilitation and prevention on the knee use the Posturomed, the mat or even the small rocker board. The advocacies are given looking to the tested rehab tools.

Seroprevalence of Toxoplasma gondii antibodies in humans from rural Western Amazon, Brazil.

PubMed

Cavalcante, G T; Aguilar, D M; Camargo, L M A; Labruna, M B; de Andrade, H F; Meireles, L R; Dubey, J P; Thulliez, P; Dias, R A; Gennari, S M

2006-06-01

Antibodies to Toxoplasma gondii were assayed in sera of 266 humans from 71 farms located at Rondônia State, Western Amazon, Brazil, by the modified agglutination test (MAT) and the indirect immunofluorescent antibody test (IFAT). Antibodies were found in 195 humans (73.3%), with MAT titers of 1:25 in 11, 1:50 in 11, 1:100 in 16, 1:200 in 27, 1:400 in 38, 1:800 in 37, 1:1,600 in 22, and 1:3,200 or higher in 33. From the 71 farms visited, 69 had seropositive humans. Prevalence of anti-T. gondii antibodies increased with age of the people (P < 0.05), and no difference was observed in the occurrence by gender (P > 0.05). A sanitary questionnaire was applied in each farm, and statistical association between the serologic status and several variables were analyzed. Home-grown vegetable consumption and origin of drinking water (well or river) were the independent variables that displayed significant association (P = 0.002 and 0.02, respectively). Higher values of occurrence were found in people with consumption of home-grown vegetables (76.1%) and people that drink well water (75.4%) compared with people that did not consume this type of food (61.9%) and drink river water (55.2%). By IFAT (> or = 1:16), 194 of 266 (73%) humans were seropositive and there was a good correlation between MAT and IFAT.

Seroprevalence of Toxoplasma gondii and Neospora caninum in feral cats (Felis silvestris catus) in Majorca, Balearic Islands, Spain.

PubMed

Millán, Javier; Cabezón, Oscar; Pabón, Marcela; Dubey, J P; Almería, Sonia

2009-11-12

Felids are important in the epidemiology of Toxoplasma gondii infection because they are the only hosts that can excrete environmentally resistant oocysts. Antibodies to T. gondii and Neospora caninum were determined in serum samples from 59 feral cats (Felis silvestris catus) captured in baited traps during authorized predator control campaigns in Majorca, Balearic Islands, Spain. Antibodies to T. gondii assayed by the modified agglutination test (MAT) were found in 50 (84.7%) of 59 cats with MAT titers of 1:25 in one cat, 1:200 in four cats, 1:500 in seven cats, 1:1000 in nine cats, and >or=1:2000 in 29 cats. Seroprevalence (MAT, 1:25 or more) was significantly higher in adults (94.6%) than in juveniles (<6 months old; 40.0%). Seroprevalence to N. caninum, assayed by cELISA (VMRD) and confirmed by an indirect fluorescent antibody test, was low (6.8%, 4 of 59). The prevalence of T. gondii observed in wild cats in Majorca is one of the highest reported worldwide in this species and the highest observed in Europe to date. The results suggest that feral cats in Majorca have a high rate of T. gondii infection with important implications for public health on the island since the seropositive cats are likely to have already shed T. gondii oocysts in the environment.

Characterization of the protective capacity of flooring systems using force-deflection profiling.

PubMed

Glinka, Michal N; Karakolis, Thomas; Callaghan, Jack P; Laing, Andrew C

2013-01-01

'Safety floors' aim to decrease the risk of fall-related injuries by absorbing impact energy during falls. Ironically, excessive floor deflection during walking or standing may increase fall risk. In this study we used a materials testing system to characterize the ability of a range of floors to absorb energy during simulated head and hip impacts while resisting deflection during simulated single-leg stance. We found that energy absorption for all safety floors (mean (SD)=14.8 (4.9)J) and bedside mats (25.1 (9.3)J) was 3.2- to 5.4-fold greater than the control condition (commercial carpet). While footfall deflections were not significantly different between safety floors (1.8 (0.7)mm) and the control carpet (3.7 (0.6)mm), they were significantly higher for two bedside mats. Finally, all of the safety floors, and two bedside mats, displayed 3-10 times the energy-absorption-to-deflection ratios observed for the baseline carpet. Overall, these results suggest that the safety floors we tested effectively addressed two competing demands required to reduce fall-related injury risk; namely the ability to absorb substantial impact energy without increasing footfall deflections. This study contributes to the literature suggesting that safety floors are a promising intervention for reducing fall-related injury risk in older adults. Copyright © 2012 IPEM. Published by Elsevier Ltd. All rights reserved.

Leptospira Serovars for Diagnosis of Leptospirosis in Humans and Animals in Africa: Common Leptospira Isolates and Reservoir Hosts.

PubMed

Mgode, Georgies F; Machang'u, Robert S; Mhamphi, Ginethon G; Katakweba, Abdul; Mulungu, Loth S; Durnez, Lies; Leirs, Herwig; Hartskeerl, Rudy A; Belmain, Steven R

2015-12-01

The burden of leptospirosis in humans and animals in Africa is higher than that reported from other parts of the world. However, the disease is not routinely diagnosed in the continent. One of major factors limiting diagnosis is the poor availability of live isolates of locally circulating Leptospira serovars for inclusion in the antigen panel of the gold standard microscopic agglutination test (MAT) for detecting antibodies against leptospirosis. To gain insight in Leptospira serovars and their natural hosts occurring in Tanzania, concomitantly enabling the improvement of the MAT by inclusion of fresh local isolates, a total of 52 Leptospira isolates were obtained from fresh urine and kidney homogenates, collected between 1996 and 2006 from small mammals, cattle and pigs. Isolates were identified by serogrouping, cross agglutination absorption test (CAAT), and molecular typing. Common Leptospira serovars with their respective animal hosts were: Sokoine (cattle and rodents); Kenya (rodents and shrews); Mwogolo (rodents); Lora (rodents); Qunjian (rodent); serogroup Grippotyphosa (cattle); and an unknown serogroup from pigs. Inclusion of local serovars particularly serovar Sokoine in MAT revealed a 10-fold increase in leptospirosis prevalence in Tanzania from 1.9% to 16.9% in rodents and 0.26% to 10.75% in humans. This indicates that local serovars are useful for diagnosis of human and animal leptospirosis in Tanzania and other African countries.

Leptospira Serovars for Diagnosis of Leptospirosis in Humans and Animals in Africa: Common Leptospira Isolates and Reservoir Hosts

PubMed Central

Mgode, Georgies F.; Machang’u, Robert S.; Mhamphi, Ginethon G.; Katakweba, Abdul; Mulungu, Loth S.; Durnez, Lies; Leirs, Herwig; Hartskeerl, Rudy A.; Belmain, Steven R.

2015-01-01

The burden of leptospirosis in humans and animals in Africa is higher than that reported from other parts of the world. However, the disease is not routinely diagnosed in the continent. One of major factors limiting diagnosis is the poor availability of live isolates of locally circulating Leptospira serovars for inclusion in the antigen panel of the gold standard microscopic agglutination test (MAT) for detecting antibodies against leptospirosis. To gain insight in Leptospira serovars and their natural hosts occurring in Tanzania, concomitantly enabling the improvement of the MAT by inclusion of fresh local isolates, a total of 52 Leptospira isolates were obtained from fresh urine and kidney homogenates, collected between 1996 and 2006 from small mammals, cattle and pigs. Isolates were identified by serogrouping, cross agglutination absorption test (CAAT), and molecular typing. Common Leptospira serovars with their respective animal hosts were: Sokoine (cattle and rodents); Kenya (rodents and shrews); Mwogolo (rodents); Lora (rodents); Qunjian (rodent); serogroup Grippotyphosa (cattle); and an unknown serogroup from pigs. Inclusion of local serovars particularly serovar Sokoine in MAT revealed a 10-fold increase in leptospirosis prevalence in Tanzania from 1.9% to 16.9% in rodents and 0.26% to 10.75% in humans. This indicates that local serovars are useful for diagnosis of human and animal leptospirosis in Tanzania and other African countries. PMID:26624890

Absolute position calculation for a desktop mobile rehabilitation robot based on three optical mouse sensors.

PubMed

Zabaleta, Haritz; Valencia, David; Perry, Joel; Veneman, Jan; Keller, Thierry

2011-01-01

ArmAssist is a wireless robot for post stroke upper limb rehabilitation. Knowing the position of the arm is essential for any rehabilitation device. In this paper, we describe a method based on an artificial landmark navigation system. The navigation system uses three optical mouse sensors. This enables the building of a cheap but reliable position sensor. Two of the sensors are the data source for odometry calculations, and the third optical mouse sensor takes very low resolution pictures of a custom designed mat. These pictures are processed by an optical symbol recognition algorithm which will estimate the orientation of the robot and recognize the landmarks placed on the mat. The data fusion strategy is described to detect the misclassifications of the landmarks in order to fuse only reliable information. The orientation given by the optical symbol recognition (OSR) algorithm is used to improve significantly the odometry and the recognition of the landmarks is used to reference the odometry to a absolute coordinate system. The system was tested using a 3D motion capture system. With the actual mat configuration, in a field of motion of 710 × 450 mm, the maximum error in position estimation was 49.61 mm with an average error of 36.70 ± 22.50 mm. The average test duration was 36.5 seconds and the average path length was 4173 mm.

Serological investigation of Leptospira infection and its circulation in one intensive-type water buffalo farm in the Philippines.

PubMed

Villanueva, Marvin A; Mingala, Claro N; Gloriani, Nina G; Yanagihara, Yasutake; Isoda, Norikazu; Nakajima, Chie; Suzuki, Yasuhiko; Koizumi, Nobuo

2016-02-01

Water buffalo is an indispensable livestock in the Philippines. Leptospirosis is a serious zoonosis that can be fatal to humans and cause reproductive problems in livestock. Leptospirosis has been reported in some countries where water buffaloes are commercially raised, highlighting the Leptospira prevalence in this farming system, but information on leptospirosis in water buffalo farms in the Philippines is limited. In this study, we collected blood samples from rats (n = 21), and water buffaloes (n = 170) from different groups and locations in one intensive-type buffalo farm in the Philippines. Serum was analyzed by microscopic agglutination test (MAT). Anti-Leptospira antibodies reacting with serogroups Canicola, Icterohaemorrhagiae and Pomona were found in sera of 30% tested rats, and 48% of water buffalo sera tested positive for at least one Leptospira strain, in which serogroups Mini, Hebdomadis, Tarassovi and Pyrogenes were predominantly agglutinated. The number of seropositive young water buffaloes (< 1 year-old) was lower than that of older seropositive ones. Furthermore, sera from younger water buffaloes were reactive with single serotypes with low MAT titers, but older animals were reactive with multiple Leptospira strains with variable MAT titers. In addition, antibodies against serogroups Icterohaemorrhagiae and Pomona were detected in both animals. Finally, Leptospira infection was found associated with age and animal grouping, highlighting the impact of management in the persistence of leptospirosis at intensive-type buffalo farm settings in the Philippines. Further investigation and appropriate control strategies are required to prevent leptospirosis from causing risks to public health and economic losses to the water buffalo farming industry.

Vertically aligned carbon nanotubes for microelectrode arrays applications.

PubMed

Castro Smirnov, J R; Jover, Eric; Amade, Roger; Gabriel, Gemma; Villa, Rosa; Bertran, Enric

2012-09-01

In this work a methodology to fabricate carbon nanotube based electrodes using plasma enhanced chemical vapour deposition has been explored and defined. The final integrated microelectrode based devices should present specific properties that make them suitable for microelectrode arrays applications. The methodology studied has been focused on the preparation of highly regular and dense vertically aligned carbon nanotube (VACNT) mat compatible with the standard lithography used for microelectrode arrays technology.

Coordinating Learning Agents for Active Information Collection

DTIC Science & Technology

2011-06-30

the experiments were not particularly sensitive to this parameter. By limiting the number of actions that are updated (DANT-L in black/ dark ), the...Bazzan, A. and Ossowski, S. (eds.), Applications of Agent Technology in Traffic and Transportation (Springer, 2005). [19] Mataric , M. J., Coordination...organizing market (1998), preprint cond- mat/9802177. [19] Jones, C. and Mataric , M. J., Adaptive division of labor in large-scale multi-robot systems, in IEEE

B-52B Cockpit Instrument Panel

NASA Technical Reports Server (NTRS)

1996-01-01

This photo shows a close-up view of the instrument panel in the cockpit of NASA's B-52 research aircraft. Over the course of more than 40 years, the B-52 launched numerous experimental aircraft, ranging from the X-15 to the HiMAT, and was also used as a flying testbed for a variety of other research projects. NASA B-52, Tail Number 008, is an air launch carrier aircraft, 'mothership,' as well as a research aircraft platform that has been used on a variety of research projects. The aircraft, a 'B' model built in 1952 and first flown on June 11, 1955, is the oldest B-52 in flying status and has been used on some of the most significant research projects in aerospace history. Some of the significant projects supported by B-52 008 include the X-15, the lifting bodies, HiMAT (highly maneuverable aircraft technology), Pegasus, validation of parachute systems developed for the space shuttle program (solid-rocket-booster recovery system and the orbiter drag chute system), and the X-38. The B-52 served as the launch vehicle on 106 X-15 flights and flew a total of 159 captive-carry and launch missions in support of that program from June 1959 to October 1968. Information gained from the highly successful X-15 program contributed to the Mercury, Gemini, and Apollo human spaceflight programs as well as space shuttle development. Between 1966 and 1975, the B-52 served as the launch aircraft for 127 of the 144 wingless lifting body flights. In the 1970s and 1980s, the B-52 was the launch aircraft for several aircraft at what is now the Dryden Flight Research Center, Edwards, California, to study spin-stall, high-angle-of attack, and maneuvering characteristics. These included the 3/8-scale F-15/spin research vehicle (SRV), the HiMAT (Highly Maneuverable Aircraft Technology) research vehicle, and the DAST (drones for aerodynamic and structural testing). The aircraft supported the development of parachute recovery systems used to recover the space shuttle solid rocket booster casings. It also supported eight orbiter (space shuttle) drag chute tests in 1990. In addition, the B-52 served as the air launch platform for the first six Pegasus space boosters. During its many years of service, the B-52 has undergone several modifications. The first major modification was made by North American Aviation (now part of Boeing) in support of the X-15 program. This involved creating a launch-panel-operator station for monitoring the status of the test vehicle being carried, cutting a large notch in the right inboard wing flap to accommodate the vertical tail of the X-15 aircraft, and installing a wing pylon that enables the B-52 to carry research vehicles and test articles to be air-launched/dropped. Located on the right wing, between the inboard engine pylon and the fuselage, this wing pylon was subjected to extensive testing prior to its use. For each test vehicle the B-52 carried, minor changes were made to the launch-panel operator's station. Built originally by the Boeing Company, the NASA B-52 is powered by eight Pratt & Whitney J57-19 turbojet engines, each of which produce 12,000 pounds of thrust. The aircraft's normal launch speed has been Mach 0.8 (about 530 miles per hour) and its normal drop altitude has been 40,000 to 45,000 feet. It is 156 feet long and has a wing span of 185 feet. The heaviest load it has carried was the No. 2 X-15 aircraft at 53,100 pounds. Project manager for the aircraft is Roy Bryant.

A knowledge-based system design/information tool for aircraft flight control systems

NASA Technical Reports Server (NTRS)

Mackall, Dale A.; Allen, James G.

1989-01-01

Research aircraft have become increasingly dependent on advanced control systems to accomplish program goals. These aircraft are integrating multiple disciplines to improve performance and satisfy research objectives. This integration is being accomplished through electronic control systems. Because of the number of systems involved and the variety of engineering disciplines, systems design methods and information management have become essential to program success. The primary objective of the system design/information tool for aircraft flight control system is to help transfer flight control system design knowledge to the flight test community. By providing all of the design information and covering multiple disciplines in a structured, graphical manner, flight control systems can more easily be understood by the test engineers. This will provide the engineers with the information needed to thoroughly ground test the system and thereby reduce the likelihood of serious design errors surfacing in flight. The secondary objective is to apply structured design techniques to all of the design domains. By using the techniques in the top level system design down through the detailed hardware and software designs, it is hoped that fewer design anomalies will result. The flight test experiences of three highly complex, integrated aircraft programs are reviewed: the X-29 forward-swept wing, the advanced fighter technology integration (AFTI) F-16, and the highly maneuverable aircraft technology (HiMAT) program. Significant operating anomalies and the design errors which cause them, are examined to help identify what functions a system design/information tool should provide to assist designers in avoiding errors.

Pyrogen detection methods: Comparison of bovine whole blood assay (bWBA) and monocyte activation test (MAT)

PubMed Central

2014-01-01

Background Pyrogen detection is of utmost importance in pharmaceutical industry, laboratories and health care institutions. As an alternative to the animal-consuming rabbit pyrogen test or Limulus amoebocyte lysate test, the monocyte activation test was introduced as a gold standard method in the European Pharmacopoeia. However, the monocyte activation test has not gained wide acceptance in practice. Methods We stimulated bovine whole blood with different endotoxin preparations (lipopolysaccharide E.coli 0127:B8 and 0113:H10), as well as the non-endotoxin pyrogens peptidoglycan and lipoteichoic acid. Prostaglandin E2 (PGE2) served as read out. Results Employing PGE2 as read out enabled detection limits of 0.04 EU/ml for lipopolysaccharide 0127:B8, 0.25 EU/ml for lipopolysaccharide 0113:H10 and 10 μg/ml of lipoteichoic acid as well as peptidoglycan. To evaluate the bWBA test system as a possible alternative to the MAT we performed a peer-to-peer comparison of the two methods and confirmed similar sensitivities. Conclusions In conclusion, the bovine whole blood assay (bWBA) reproducibly enabled sensitive detection of endotoxin and non-endotoxin pyrogens and may thus become a viable alternative for pyrogen testing. PMID:25209100

Analysis of bacterial and archaeal diversity in coastal microbial mats using massive parallel 16S rRNA gene tag sequencing.

PubMed

Bolhuis, Henk; Stal, Lucas J

2011-11-01

Coastal microbial mats are small-scale and largely closed ecosystems in which a plethora of different functional groups of microorganisms are responsible for the biogeochemical cycling of the elements. Coastal microbial mats play an important role in coastal protection and morphodynamics through stabilization of the sediments and by initiating the development of salt-marshes. Little is known about the bacterial and especially archaeal diversity and how it contributes to the ecological functioning of coastal microbial mats. Here, we analyzed three different types of coastal microbial mats that are located along a tidal gradient and can be characterized as marine (ST2), brackish (ST3) and freshwater (ST3) systems. The mats were sampled during three different seasons and subjected to massive parallel tag sequencing of the V6 region of the 16S rRNA genes of Bacteria and Archaea. Sequence analysis revealed that the mats are among the most diverse marine ecosystems studied so far and consist of several novel taxonomic levels ranging from classes to species. The diversity between the different mat types was far more pronounced than the changes between the different seasons at one location. The archaeal community for these mats have not been studied before and revealed a strong reaction on a short period of draught during summer resulting in a massive increase in halobacterial sequences, whereas the bacterial community was barely affected. We concluded that the community composition and the microbial diversity were intrinsic of the mat type and depend on the location along the tidal gradient indicating a relation with salinity.

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

Electrospinning and stabilization of chitosan nanofiber mats

NASA Astrophysics Data System (ADS)

Grimmelsmann, N.; Grothe, T.; Homburg, S. V.; Ehrmann, A.

2017-10-01

Chitosan is of special interest for biotechnological and medical applications due to its antibacterial, antifungal and other intrinsic physical and chemical properties. The biopolymer can, e.g., be used for biotechnological purposes, as a filter medium, in medical products, etc. In all these applications, the inner surface should be maximized to increase the contact area with the filtered medium etc. and thus the chitosan’s efficacy. Chitosan dissolves in acidic solutions, opposite to neutral water. Electrospinning is possible, e.g., by co-spinning with PEO (poly(ethylene oxide)). Tests with different chitosan:PEO ratios revealed that higher PEO fractions resulted in better spinnability and more regular fibre mats, but make stabilization of the fibre structure more challenging.

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

The green alga, Cladophora, promotes Escherichia coli growth and contamination of recreational waters in Lake Michigan

USGS Publications Warehouse

Heuvel, A.V.; McDermott, C.; Pillsbury, R.; Sandrin, T.; Kinzelman, J.; Ferguson, J.; Sadowsky, M.; Byappanahalli, M.; Whitman, R.; Kleinheinz, G.T.

2010-01-01

A linkage between Cladophora mats and exceedances of recreational water quality criteria has been suggested, but not directly studied. Th is study investigates the spatial and temporal association between Escherichia coli concentrations within and near Cladophora mats at two northwestern Lake Michigan beaches in Door County, Wisconsin. Escherichia coli concentrations in water underlying mats were significantly greater than surrounding water (p < 0.001). Below mat E. coli increased as the stranded mats persisted at the beach swash zone. Water adjacent to Cladophora mats had lower E. coli concentrations, but surpassed EPA swimming criteria the majority of sampling days. A signifi cant positive association was found between E. coli concentrations attached to Cladophora and in underlying water (p < 0.001). The attached E. coli likely acted as a reservoir for populating water underlying the mat. Fecal bacterial pathogens, however, could not be detected by microbiological culture methods either attached to mat biomass or in underlying water. Removal of Cladophora mats from beach areas may improve aesthetic and microbial water quality at affected beaches. These associations and potential natural growth of E. coli in bathing waters call into question the efficacy of using E. coli as a recreational water quality indicator of fecal contaminations. Copyright ?? 2010 by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America. All rights reserved.

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.

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.

Steps for Action : getting intelligent transportation systems ready for the year 2000

DOT National Transportation Integrated Search

1998-09-01

Hazardous Materials Incident Response Cross-Cutting report summarizes and interprets the results of three Field Operational Tests (FOTs) that are evaluating systems for improving the accuracy and availability of HazMat information provided to emergen...

Clean Air Act Second Prospective Report Study Science Advisory Board Review Teleconference, August 11, 2010

EPA Pesticide Factsheets

This technical memorandum provides a description of the Adjustment to the Primary Particulate Matter Emissions Estimates and the Modeled Attainment Test Software Analysis (MATS) Procedure for the 812 Second Prospective Analysis

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.

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.

Diagnostic Classification Models and Multidimensional Adaptive Testing: A Commentary on Rupp and Templin

ERIC Educational Resources Information Center

Frey, Andreas; Carstensen, Claus H.

2009-01-01

On a general level, the objective of diagnostic classifications models (DCMs) lies in a classification of individuals regarding multiple latent skills. In this article, the authors show that this objective can be achieved by multidimensional adaptive testing (MAT) as well. The authors discuss whether or not the restricted applicability of DCMs can…

Prevalence and genetic characterization of Toxoplasma gondii in free-range chickens from grocery stores and farms

USDA-ARS?s Scientific Manuscript database

Chickens are considered important in the epidemiology of Toxoplasma gondii. Chicken hearts (n=1185) obtained from the local markets were tested for T. gondii infection. Antibodies to T. gondii were assayed in fluid removed from the heart cavity using the modified agglutination test (MAT) at 1:5, 1:2...

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

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.

Medication assisted treatment in US drug courts: results from a nationwide survey of availability, barriers and attitudes.

PubMed

Matusow, Harlan; Dickman, Samuel L; Rich, Josiah D; Fong, Chunki; Dumont, Dora M; Hardin, Carolyn; Marlowe, Douglas; Rosenblum, Andrew

2013-01-01

Drug treatment courts are an increasingly important tool in reducing the census of those incarcerated for non-violent drug offenses; medication assisted treatment (MAT) is proven to be an effective treatment for opioid addiction. However, little is known about the availability of and barriers to MAT provision for opioid-addicted people under drug court jurisdiction. Using an online survey, we assessed availability, barriers, and need for MAT (especially agonist medication) for opioid addiction in drug courts. Ninety-eight percent reported opioid-addicted participants, and 47% offered agonist medication (56% for all MAT including naltrexone). Barriers included cost and court policy. Responses revealed significant uncertainty, especially among non-MAT providing courts. Political, judicial and administrative opposition appear to affect MAT's inconsistent use and availability in drug court settings. These data suggest that a substantial, targeted educational initiative is needed to increase awareness of the treatment and criminal justice benefits of MAT in the drug courts. Copyright © 2013 Elsevier Inc. All rights reserved.

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.

Suspected microbial-induced sedimentary structures (MISS) in Furongian (Upper Cambrian; Jiangshanian, Sunwaptan) strata of the Upper Mississippi Valley

USGS Publications Warehouse

Eoff, Jennifer D.

2014-01-01

The Furongian (Upper Cambrian; Jiangshanian and Sunwaptan) Tunnel City Group (Lone Rock Formation and Mazomanie Formation), exposed in Wisconsin and Minnesota, represents a shallow-marine clastic environment during a time of exceptionally high sea level. Lithofacies from shoreface to transitional-offshore settings document deposition in a wave- and storm-dominated sea. Flooding of the cratonic interior was associated with formation of a condensed section and the extensive development of microbial mats. Biolamination, mat fragments, wrinkle structures, and syneresis cracks are preserved in various sandstone facies of the Lone Rock Formation, as is evidence for the cohesive behavior of sand. These microbial-induced sedimentary structures (MISS) provide unique signals of biological–physical processes that physical structures alone cannot mimic. The MISS are associated with a trilobite extinction event in the Steptoean–Sunwaptan boundary interval. This may support recent claims that Phanerozoic microbial mats were opportunistic disaster forms that flourished during periods of faunal turnover. Further investigation of stratigraphic, taphonomic, and other potential biases, however, is needed to fully test this hypothesis.

Predicting the Dynamic Crushing Response of a Composite Honeycomb Energy Absorber Using Solid-Element-Based Models in LS-DYNA

NASA Technical Reports Server (NTRS)

Jackson, Karen E.

2010-01-01

This paper describes an analytical study that was performed as part of the development of an externally deployable energy absorber (DEA) concept. The concept consists of a composite honeycomb structure that can be stowed until needed to provide energy attenuation during a crash event, much like an external airbag system. One goal of the DEA development project was to generate a robust and reliable Finite Element Model (FEM) of the DEA that could be used to accurately predict its crush response under dynamic loading. The results of dynamic crush tests of 50-, 104-, and 68-cell DEA components are presented, and compared with simulation results from a solid-element FEM. Simulations of the FEM were performed in LS-DYNA(Registered TradeMark) to compare the capabilities of three different material models: MAT 63 (crushable foam), MAT 26 (honeycomb), and MAT 126 (modified honeycomb). These material models are evaluated to determine if they can be used to accurately predict both the uniform crushing and final compaction phases of the DEA for normal and off-axis loading conditions

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.

Development Challenges of Game-Changing Entry System Technologies from Concept to Mission Infusion

NASA Technical Reports Server (NTRS)

Venkatapathy, Ethiraj; Beck, Robin; Ellerby, Don; Feldman, Jay; Gage, Peter; Munk, Michelle; Wercinski, Paul

2015-01-01

Realization within the US and NASA that future exploration both Human and Robotic will require innovative new technologies led to the creation of the Space Technology Mission Directorate and investment in game changing technologies with high pay-off. Some of these investments will see success and others, due to many of the constraints, will not attain their goal. The co-authors of this proposed presentation have been involved from concept to mission infusion aspects of entry technologies that are game changing. The four example technologies used to describe the challenges experienced along the pathways to success are at different levels of maturity. They are Conformal, 3-D MAT, HEEET and ADEPT. The four examples in many ways capture broad aspects of the challenges of maturation and illustrate what led some to be exceptionally successful and how others had to be altered in order remain viable game changing technologies. Subsystem technologies for robotic and human missions?

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 microorganisms as well as networks of C flow within mats; thus they offer insights about community structure. For example, relative 13C/12C values of individual lipid biosignatures can indicate trophic relationships between key groups of microorganisms. Mat microenvironments can affect the stability of authigenic minerals and alter the chemical compositions and crystal forms of carbonate, sulfate and metal oxide minerals. Interactions between low molecular weight organic compounds and sulfides in mat pore waters can produce alkyl sulfide gases. Processes associated with these physically coherent biofilms can trap and bind detrital grains, enhance mineral precipitation or dissolution, and stabilize sediment surfaces. Accordingly mats can create distinctive sedimentary fabrics and structures. Stromatolites are the most ancient, widespread examples of such fabrics and structures. Thus photosynthetic microbial mats create diverse biosignatures that, when preserved in the geologic record, can help to identify the former presence of key populations of microorganisms and reveal key processes that occurred within ancient mats as well as the interactions between those ecosystems and their environment.

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...

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...

17 CFR 249.1300T - Form MA-T, for temporary registration as a municipal advisor, and for amendments to, and...

Code of Federal Regulations, 2014 CFR

2014-04-01

... 17 Commodity and Securities Exchanges 4 2014-04-01 2014-04-01 false Form MA-T, for temporary... Information Regarding Certain Natural Persons § 249.1300T Form MA-T, for temporary registration as a municipal... Register citations affecting Form MA-T, see the List of CFR Sections Affected, which appears in the Finding...

Exposure to brominated and organophosphate ester flame retardants in U.S. childcare environments: Effect of removal of flame-retarded nap mats on indoor levels.

PubMed

Stubbings, W A; Schreder, E D; Thomas, M B; Romanak, K; Venier, M; Salamova, A

2018-07-01

We assessed exposure to 39 brominated and 16 organophosphate ester flame retardants (FRs) from both dust and indoor air at seven childcare centres in Seattle, USA, and investigated the importance of nap mats as a source of these chemicals. Many childcare centres serving young children use polyurethane foam mats for the children's naptime. Until recently, the vast majority of these mats sold in the United States contained flame-retarded polyurethane foam to meet California Technical Bulletin 117 (TB117) requirements. With the 2013 update of TB117, allowing manufacturers to meet flammability standards without adding FRs to filling materials, FR-free nap mats have become widely available. We conducted an intervention study by actively switching out FR-treated nap mats with FR-free nap mats and measuring FR levels in indoor air and dust before and after the switch-out. The predominant FRs found in dust and indoor air were 2-ethylhexyl tetrabromobenzoate (EHTBB) and tris(1-chloro-2-propyl) phosphate (TCIPP), respectively. Nap mat samples analysed from four of the six centres contained a Firemaster ® mixture, while one mat was predominantly treated with tris(1,3-dichloroisopropyl) phosphate (TDCIPP) and the other contained no detectable target FRs. After replacement, there was a significant decrease (p = 0.03-0.09) in median dust concentrations for bis(2-ethylhexyl) tetrabromophthalate (BEHTBP), EHTBB, tris(4-butylphenyl) phosphate (TBPP), and TDCIPP with reductions of 90%, 79%, 65%, and 42%, respectively. These findings suggest that the nap mats were an important source of these FRs to dust in the investigated childcare environments and that a campaign of swapping out flame-retarded mats for FR-free ones would reduce exposure to these chemicals. While calculated exposure estimates to the investigated FRs via inhalation, dust ingestion, and dermal absorption were below established reference dose values, they are likely underestimated when considering the toddlers' direct contact to the mats and personal cloud effects. Copyright © 2018 Elsevier Ltd. All rights reserved.

Contribution by Macroalgal Mats to Primary Production of a Shallow Embayment Under High and Low Nitrogen-loading Rates

NASA Astrophysics Data System (ADS)

Peckol, P.; Rivers, J. S.

1996-09-01

The limits on primary production in areas undergoing eutrophication may be set by indirect effects of nitrogen loading, i.e. decreasing irradiances, associated with proliferating opportunistic algae. Using in situphoton flux density (PFD) availability estimates within unattached algal mats and photosynthetic parameters determined from photosynthesis vs.irradiance (P vs.I) curves generated for the dominant components of mat assemblages, Cladophora vagabundaand Gracilaria tikvahiae, seasonal net mat production rate for estuaries (Waquoit Bay, Massachusetts, U.S.A.) receiving high (Childs River) and low (Sage Lot Pond) N-loading rates were determined. Although abundance of C. vagabundawas 2× greater than G. tikvahiae, the former species contributed only about 50% of total mat productivity, due largely to rapid light attenuation within the dense algal mat. While mat production was low and similar at both sides during winter (≈0·35 g C m -2 day -1), for other seasons, the net mat daytime productivity at Childs River, the N-loaded site, was 2·5× higher than rates determined for Sage Lot Pond. Although annual net daytime production at Childs River (1094 g C m -2 year -1) was comparable to estimates for other algal mat assemblages in eutrophic systems, primary production of the Waquoit Bay system was found to become self-limiting as available PFD controls maximum productivity. In photosynthetically inactive portions of the algal mat, carbon release was estimated from tissue-loss measurements at 0·14 g C m -2 day -1for C. vagabundaand 0·05 g C m -2 day -1for G. tikvahiae. Annual in situC release of 73 g C m -2is ≈20% of annual net mat production (fixed carbon not respired by algae) in this embayment. Although both estuaries showed net autotrophy year round (Pg:R>1), the high metabolic cost of a large, inactive mat resulted in lower Pg:R ratios at Childs Rivers than at Sage Lot Pond, particularly during the summer period of peak production. Thus, it is predicted that the Waquoit Bay system will experience an overall decline in Pg:R ratios and consequent increase in anoxic events as eutrophication continues.

Forward-swept wing configuration designed for high maneuverability by use of a transonic computational method

NASA Technical Reports Server (NTRS)

Mann, M. J.; Mercer, C. E.

1986-01-01

A transonic computational analysis method and a transonic design procedure have been used to design the wing and the canard of a forward-swept-wing fighter configuration for good transonic maneuver performance. A model of this configuration was tested in the Langley 16-Foot Transonic Tunnel. Oil-flow photographs were obtained to examine the wind flow patterns at Mach numbers from 0.60 to 0.90. The transonic theory gave a reasonably good estimate of the wing pressure distributions at transonic maneuver conditions. Comparison of the forward-swept-wing configuration with an equivalent aft-swept-wing-configuration showed that, at a Mach number of 0.90 and a lift coefficient of 0.9, the two configurations have the same trimmed drag. The forward-swept wing configuration was also found to have trimmed drag levels at transonic maneuver conditions which are comparable to those of the HiMAT (highly maneuverable aircraft technology) configuration and the X-29 forward-swept-wing research configuration. The configuration of this study was also tested with a forebody strake.

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 sedimentary textures, organic compounds, and minerals that enter the fossil record. The ability of cyanobacterial mats to channel abundant solar energy into the creation and maintenance of complex structures and processes has created a multitude of consequences, both for sedimentation and for the early evolution of our biosphere.

Passive Mixing Capabilities of Micro- and Nanofibres When Used in Microfluidic Systems.

PubMed

Matlock-Colangelo, Lauren; Colangelo, Nicholas W; Fenzl, Christoph; Frey, Margaret W; Baeumner, Antje J

2016-08-05

Nanofibres are increasingly being used in the field of bioanalytics due to their large surface-area-to-volume ratios and easy-to-functionalize surfaces. To date, nanofibres have been studied as effective filters, concentrators, and immobilization matrices within microfluidic devices. In addition, they are frequently used as optical and electrochemical transduction materials. In this work, we demonstrate that electrospun nanofibre mats cause appreciable passive mixing and therefore provide dual functionality when incorporated within microfluidic systems. Specifically, electrospun nanofibre mats were integrated into Y-shaped poly(methyl methacrylate) microchannels and the degree of mixing was quantified using fluorescence microscopy and ImageJ analysis. The degree of mixing afforded in relationship to fibre diameter, mat height, and mat length was studied. We observed that the most mixing was caused by small diameter PVA nanofibres (450-550 nm in diameter), producing up to 71% mixing at the microchannel outlet, compared to up to 51% with polystyrene microfibres (0.8-2.7 μm in diameter) and 29% mixing in control channels containing no fibres. The mixing afforded by the PVA nanofibres is caused by significant inhomogeneity in pore size and distribution leading to percolation. As expected, within all the studies, fluid mixing increased with fibre mat height, which corresponds to the vertical space of the microchannel occupied by the fibre mats. Doubling the height of the fibre mat led to an average increase in mixing of 14% for the PVA nanofibres and 8% for the PS microfibres. Overall, mixing was independent of the length of the fibre mat used (3-10 mm), suggesting that most mixing occurs as fluid enters and exits the fibre mat. The mixing effects observed within the fibre mats were comparable to or better than many passive mixers reported in literature. Since the nanofibre mats can be further functionalized to couple analyte concentration, immobilization, and detection with enhanced fluid mixing, they are a promising nanomaterial providing dual-functionality within lab-on-a-chip devices.

Passive Mixing Capabilities of Micro- and Nanofibres When Used in Microfluidic Systems

PubMed Central

Matlock-Colangelo, Lauren; Colangelo, Nicholas W.; Fenzl, Christoph; Frey, Margaret W.; Baeumner, Antje J.

2016-01-01

Nanofibres are increasingly being used in the field of bioanalytics due to their large surface-area-to-volume ratios and easy-to-functionalize surfaces. To date, nanofibres have been studied as effective filters, concentrators, and immobilization matrices within microfluidic devices. In addition, they are frequently used as optical and electrochemical transduction materials. In this work, we demonstrate that electrospun nanofibre mats cause appreciable passive mixing and therefore provide dual functionality when incorporated within microfluidic systems. Specifically, electrospun nanofibre mats were integrated into Y-shaped poly(methyl methacrylate) microchannels and the degree of mixing was quantified using fluorescence microscopy and ImageJ analysis. The degree of mixing afforded in relationship to fibre diameter, mat height, and mat length was studied. We observed that the most mixing was caused by small diameter PVA nanofibres (450–550 nm in diameter), producing up to 71% mixing at the microchannel outlet, compared to up to 51% with polystyrene microfibres (0.8–2.7 μm in diameter) and 29% mixing in control channels containing no fibres. The mixing afforded by the PVA nanofibres is caused by significant inhomogeneity in pore size and distribution leading to percolation. As expected, within all the studies, fluid mixing increased with fibre mat height, which corresponds to the vertical space of the microchannel occupied by the fibre mats. Doubling the height of the fibre mat led to an average increase in mixing of 14% for the PVA nanofibres and 8% for the PS microfibres. Overall, mixing was independent of the length of the fibre mat used (3–10 mm), suggesting that most mixing occurs as fluid enters and exits the fibre mat. The mixing effects observed within the fibre mats were comparable to or better than many passive mixers reported in literature. Since the nanofibre mats can be further functionalized to couple analyte concentration, immobilization, and detection with enhanced fluid mixing, they are a promising nanomaterial providing dual-functionality within lab-on-a-chip devices. PMID:27527184

Mean Annual Temperature Drives Microbial Nitrogen Cycling and Fine Root Nutrient Foraging Across a Tropical Montane Wet Forest Elevation Gradient

NASA Astrophysics Data System (ADS)

Pierre, S.; Litton, C. L. M.; Giardina, C. P.; Sparks, J. P.; Groffman, P. M.; Hewson, I.; Fahey, T. J.

2017-12-01

Mean annual temperature (MAT) is positively correlated with rates of primary production and carbon (C) turnover in forests globally, but the underlying biotic drivers of these relationships remain poorly resolved. We hypothesized that (1) MAT increases nitrifier abundance and thereby nitrate (NO-) bioavailability in soils and (2) increased NO- bioavailability reduces fine root nitrogen (N) demand. We used an ecologically well-constrained natural elevation gradient (13˚C -18˚C) in a tropical wet motane forest on the Island of Hawaii to study to role of MAT in situ. Our previous work showed that MAT drives increased soil NO- bioavailability in situ (r²=0.79, P=0.003), and indicated that the abundance of ammonia oxidizing archaea is strongly and positively correlated with MAT in situ (r²=0.34, P<0.001; Pierre et. al. 2017). Using fertilized fine root ingrowth cores (+N, +P, +N+P, control) across the same MAT gradient, we found that increasing MAT and bulk soil NO- bioavailability produced a significant negative fine root response to the +N+P treatment (P=0.023), and no response to other fertilization treatments. Increasing MAT and soil NO- bioavailability led to increased percent arbuscular mycorrhizal (AM) colonization of fine roots (r²=0.43, P=0.004), but no treatment effect on AM colonization was observed. Our results suggest that N and P generally co-limit fine root foraging across the gradient, while higher MAT and bulk soil NO- bioavailability interact to reduce fine root foraging effort. Further, higher MAT and greater N fertility in soils may reduce the C limitation of AM fungal colonization. We conclude that MAT drives N-rich conditions, which allow for lower N foraging effort, but greater C investment in P acquisition through AM fine root colonization.

Marrow Adipose Tissue in Older Men: Association with Visceral and Subcutaneous Fat, Bone Volume, Metabolism, and Inflammation.

PubMed

Bani Hassan, Ebrahim; Demontiero, Oddom; Vogrin, Sara; Ng, Alvin; Duque, Gustavo

2018-03-26

Marrow (MAT) and subcutaneous (SAT) adipose tissues display different metabolic profiles and varying associations with aging, bone density, and fracture risk. Using a non-invasive imaging methodology, we aimed to investigate the associations between MAT, SAT, and visceral fat (VAT) with bone volume, bone remodeling markers, insulin resistance, and circulating inflammatory mediators in a population of older men. In this cross-sectional study, 96 healthy men (mean age 67 ± 5.5) were assessed for anthropometric parameters, body composition, serum biochemistry, and inflammatory panel. Using single-energy computed tomography images, MAT (in L2 and L3 and both hips), VAT, and SAT (at the level of L2-L3 and L4-L5) were measured employing Slice-O-Matic software (Tomovision), which enables specific tissue demarcation applying previously reported Hounsfield unit thresholds. MAT volume was similar in all anatomical sites and independent of BMI. In all femoral regions of interest (ROIs) there was a strong negative association between bone and MAT volumes (r = - 0.840 to - 0.972, p < 0.001), with location-dependent variations in the lumbar spine. Unlike VAT and SAT, no associations between MAT and serum glucose, inflammatory markers or insulin resistance indicators were found. Bone decline occurred without red marrow expansion; thus lost bone was mainly (if not exclusively) replaced by MAT. In conclusion, strong inverse correlations between MAT and bone mass, which have been previously observed in women, were also confirmed in older men. However, MAT volume in all ROIs was interrelated and unlike women, mainly independent of VAT or SAT. The lack of strong association between MAT vs VAT/SAT, and its discordant associations with metabolic and inflammatory mediators provide further evidence on MAT's distinct attributes in older men.

Evolutionary conserved longevity genes and human cognitive abilities in elderly cohorts

PubMed Central

Lopez, Lorna M; Harris, Sarah E; Luciano, Michelle; Liewald, Dave; Davies, Gail; Gow, Alan J; Tenesa, Albert; Payton, Antony; Ke, Xiayi; Whalley, Lawrence J; Fox, Helen; Haggerty, Paul; Ollier, William; Pickles, Andrew; Porteous, David J; Horan, Michael A; Pendleton, Neil; Starr, John M; Deary, Ian J

2012-01-01

Genetic influences have an important role in the ageing process. The genetic factors that influence success in bodily ageing may also contribute to the successful ageing of cognitive abilities. A comparative genomics approach found longevity genes conserved between yeast Saccharomyces cerevisiae and nematode Caenorhabditis elegans. We hypothesised that these longevity genes influence variance in cognitive ability and age-related cognitive decline in humans. Here, we investigated six of these genes that have human orthologs and show expression in the brain. We tested AFG3L2 (MIM: 604581, AFG3 ATPase family gene 3-like 2 (yeast)), FRAP1 (MIM: 601231, a FK506 binding protein 12-rapamycin associated protein), MAT1A, MAT2A (MIM: 610550 and 601468, methionine adenosyltransferases I alpha and II alpha, respectively), SYNJ1 and SYNJ2 (MIM: 604297 and 609410, synaptojanin-1 and synaptojanin-2, respectively) in approximately 1000 healthy older Scots: the Lothian Birth Cohort 1936 (LBC1936). They were tested on general cognitive ability at age 11 years. At a mean age of 70 years, they re-sat the same general cognitive ability test and underwent an additional battery of diverse cognitive tests. In all, 70 tag and functional SNPs in the six longevity genes were genotyped and tested for association with cognition and cognitive ageing in LBC1936. Suggestive associations were detected between SNPs in SYNJ2, MAT1A, AFG3L2 and SYNJ1 and a general memory factor and general cognitive ability at age 11 and 70 years. Replication studies for cognitive ability associations were performed in 2506 samples from the Cognitive Ageing Genetics in England and Scotland consortium. A meta-analysis replicated the SYNJ2 association with cognitive abilities (lowest P=0.00077). SYNJ2 is a novel gene in which variation is potentially associated with cognitive abilities. PMID:22045296

Reactivation of a cryptobiotic stream ecosystem in the McMurdo Dry Valleys, Antarctica: A long-term geomorphological experiment

USGS Publications Warehouse

McKnight, Diane M.; Tate, C.M.; Andrews, E.D.; Niyogi, D.K.; Cozzetto, K.; Welch, K.; Lyons, W.B.; Capone, D.G.

2007-01-01

The McMurdo Dry Valleys of Antarctica contain many glacial meltwater streams that flow for 6 to 12??weeks during the austral summer and link the glaciers to the lakes on the valley floors. Dry valley streams gain solutes longitudinally through weathering reactions and microbial processes occurring in the hyporheic zone. Some streams have thriving cyanobacterial mats. In streams with regular summer flow, the mats are freeze-dried through the winter and begin photosynthesizing with the onset of flow. To evaluate the longer term persistence of cyanobacterial mats, we diverted flow to an abandoned channel, which had not received substantial flow for approximately two decades. Monitoring of specific conductance showed that for the first 3??years after the diversion, the solute concentrations were greater in the reactivated channel than in most other dry valley streams. We observed that cyanobacterial mats became abundant in the reactivated channel within a week, indicating that the mats had been preserved in a cryptobiotic state in the channel. Over the next several years, these mats had high rates of productivity and nitrogen fixation compared to mats from other streams. Experiments in which mats from the reactivated channel and another stream were incubated in water from both of the streams indicated that the greater solute concentrations in the reactivated channel stimulated net primary productivity of mats from both streams. These stream-scale experimental results indicate that the cryptobiotic preservation of cyanobacterial mats in abandoned channels in the dry valleys allows for rapid response of these stream ecosystems to climatic and geomorphological change, similar to other arid zone stream ecosystems. ?? 2006 Elsevier B.V. All rights reserved.

Ecosystem carbon storage does not vary with mean annual temperature in Hawaiian tropical montane wet forests.

PubMed

Selmants, Paul C; Litton, Creighton M; Giardina, Christian P; Asner, Gregory P

2014-09-01

Theory and experiment agree that climate warming will increase carbon fluxes between terrestrial ecosystems and the atmosphere. The effect of this increased exchange on terrestrial carbon storage is less predictable, with important implications for potential feedbacks to the climate system. We quantified how increased mean annual temperature (MAT) affects ecosystem carbon storage in above- and belowground live biomass and detritus across a well-constrained 5.2 °C MAT gradient in tropical montane wet forests on the Island of Hawaii. This gradient does not systematically vary in biotic or abiotic factors other than MAT (i.e. dominant vegetation, substrate type and age, soil water balance, and disturbance history), allowing us to isolate the impact of MAT on ecosystem carbon storage. Live biomass carbon did not vary predictably as a function of MAT, while detrital carbon declined by ~14 Mg of carbon ha(-1) for each 1 °C rise in temperature - a trend driven entirely by coarse woody debris and litter. The largest detrital pool, soil organic carbon, was the most stable with MAT and averaged 48% of total ecosystem carbon across the MAT gradient. Total ecosystem carbon did not vary significantly with MAT, and the distribution of ecosystem carbon between live biomass and detritus remained relatively constant across the MAT gradient at ~44% and ~56%, respectively. These findings suggest that in the absence of alterations to precipitation or disturbance regimes, the size and distribution of carbon pools in tropical montane wet forests will be less sensitive to rising MAT than predicted by ecosystem models. This article also provides needed detail on how individual carbon pools and ecosystem-level carbon storage will respond to future warming. © 2014 John Wiley & Sons Ltd.

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.

Novel poly(ε-caprolactone)/gelatin wound dressings prepared by emulsion electrospinning with controlled release capacity of Ketoprofen anti-inflammatory drug.

PubMed

Basar, A O; Castro, S; Torres-Giner, S; Lagaron, J M; Turkoglu Sasmazel, H

2017-12-01

In the present study, a single and binary Ketoprofen-loaded mats of ultrathin fibers were developed by electrospinning and their physical properties and drug release capacity was analyzed. The single mat was prepared by solution electrospinning of poly(ε-caprolactone) (PCL) with Ketoprofen at a weight ratio of 5wt%. This Ketoprofen-containing PCL solution was also used as the oil phase in a 7:3 (wt/wt) emulsion with gelatin dissolved in acidified water. The resultant stable oil-in-water (O/W) emulsion of PCL-in-gelatin, also containing Ketoprofen at 5wt%, was electrospun to produce the binary mat. Cross-linking process was performed by means of glutaraldehyde vapor on the electrospun binary mat to prevent dissolution of the hydrophilic gelatin phase. The performed characterization indicated that Ketoprofen was successfully embedded in the single and binary electrospun mats, i.e. PCL and PCL/gelatin, and both mats showed high hydrophobicity but poor thermal resistance. In vitro release studies interestingly revealed that, in comparison to the single PCL electrospun mat, the binary PCL/gelatin mat significantly hindered Ketoprofen burst release and exhibited a sustained release capacity of the drug for up to 4days. In addition, the electrospun Ketoprofen-loaded mats showed enhanced attachment and proliferation of L929 mouse fibroblast cells, presenting the binary mat the highest cell growth yield due to its improved porosity. The here-developed electrospun materials clearly show a great deal of potential as novel wound dressings with an outstanding controlled capacity to release drugs. Copyright © 2017 Elsevier B.V. All rights reserved.

Freeze-thaw revival of rotifers and algae in a desiccated, high-elevation (5500 meters) microbial mat, high Andes, Perú.

PubMed

Schmidt, S K; Darcy, J L; Sommers, Pacifica; Gunawan, Eva; Knelman, J E; Yager, Karina

2017-05-01

This is the first study of the highest elevation cyanobacteria-dominated microbial mat yet described. The desiccated mat was sampled in 2010 from an ephemeral rock pool at 5500 m above sea level in the Cordillera Vilcanota of southern Perú. After being frozen for 6 years at -20 °C in the lab, pieces of the mat were sequenced to fully characterize both the 16 and 18S microbial communities and experiments were conducted to determine if organisms in the mat could revive and become active under the extreme freeze-thaw conditions that these mats experience in the field. Sequencing revealed an unexpectedly diverse, multi-trophic microbial community with 16S OTU richness comparable to similar, seasonally desiccated mats from the Dry Valleys of Antarctica and low elevation sites in the Atacama Desert region. The bacterial community of the mat was dominated by phototrophs in the Cyanobacteria (Nostoc) and the Rhodospirillales, whereas the eukaryotic community was dominated by predators such as bdelloid rotifers (Philodinidae). Microcosm experiments showed that bdelloid rotifers in the mat were able to come out of dormancy and actively forage even under realistic field conditions (diurnal temperature fluctuations of -12 °C at night to + 27 °C during the day), and after being frozen for 6 years. Our results broaden our understanding of the diversity of life in periodically desiccated, high-elevation habitats and demonstrate that extreme freeze-thaw cycles per se are not a major factor limiting the development of at least some members of these unique microbial mat systems.

APPLICATIONS ANALYSIS REPORT: SITE PROGRAM DEMONSTRATION TEST SOLIDITECH, INC. SOLIDIFICATION/ STABILIZATION PROCESS

EPA Science Inventory

This Applications Analysis Report evaluates the Soliditech, Inc., solidification/ stabilization process for the on-site treatment of waste materials. The Soliditech process mixes and chemically treats waste material with Urrichem (a proprietary reagent), additives, pozzolanic mat...

The Model Analyst’s Toolkit: Scientific Model Development, Analysis, and Validation

DTIC Science & Technology

2015-02-20

being integrated within MAT, including Granger causality. Granger causality tests whether a data series helps when predicting future values of another...relations by econometric models and cross-spectral methods. Econometrica: Journal of the Econometric Society, 424-438. Granger, C. W. (1980). Testing ... testing dataset. This effort is described in Section 3.2. 3.1. Improvements in Granger Causality User Interface Various metrics of causality are

Physical properties and morphology of electrospun composite fiber mats of polyhydroxyalkanoate containing nanoclay and tricalcium phosphate additives

NASA Astrophysics Data System (ADS)

Tanadchangsaeng, N.; Boonyagul, S.

2018-05-01

Recently, nanofiber research has gained substantial attention from scientists. In this study, the main component of the nanofiber sheet is polyhydroxyalkanoate (PHA) polymer, which is strong, ductile, flexible and adhesive to human skin. Two major additives of nanofiber sheet that we applied are nanoclay and tricalcium phosphate. The additives are generally synthetic substances that can be chemically synthesized and compatible with tissues body. Nanoclay has a low density, strong, durable to compressive strength and humidity. While, tricalcium phosphate is a calcium phosphate ceramic that is biocompatible to human tissue. From the reasons above, we proposed to choose both nanoclay and tricalcium phosphate for adding into PHA nanofibers for film formation. Thus, this study aims to investigate the morphological and mechanical properties of the fiber mat by using PHA added with various amount of nanoclay and tricalcium phosphate at 0.1%, 1% and 10% by weight, and fabricate nanofiber samples by electrospinning technique. The tested results of scanning electron microscope (SEM) morphology show that the fibers have a uniformed pattern. The PHA containing nanoclay of all additive contents exhibited micrometer diameter distributions, while PHA loaded with 1% tricalcium phosphate still had the nano-scale diameter range, and might be the optimum additive load for further nanometer medical applications. A tensile test was performed to determine the effect of nanoclay and tricalcium phosphate contents on the mechanical properties of the electrospun PHA films, and reflect the level of modularity. With nanoclay components being integrated into the polymer matrix, subsequent reduction in fiber crystallinity was occurred after addition of nanoclay with an increase of modulus value. The results confirmed that PHA fiber mat containing 1% nanoclay may have a potential for using as a rigid scaffold which bearing force loading in human organ system. Whereas, it can be indicated that PHA fiber mat containing 1% tricalcium phosphate might be employed as a flexible scaffold for biomedical materials application due to a high elongation at break value.

High prevalence and genotypes of Toxoplasma gondii isolated from organic pigs in northern USA.

PubMed

Dubey, J P; Hill, D E; Rozeboom, D W; Rajendran, C; Choudhary, S; Ferreira, L R; Kwok, O C H; Su, C

2012-08-13

The ingestion of undercooked pork infected with Toxoplasma gondii is considered an important source of transmission of this parasite. While T. gondii infection in confinement raised market pigs (market pigs are typically used for fresh, unprocessed pork products) in the USA has decreased significantly over the last 20 years, infection levels in pigs with access to the outdoors can be quite high. An upsurge in consumer demand for 'organically raised', 'humanely raised' and 'free range' pork products has resulted in increasing numbers of hogs being raised in non-confinement systems. To determine T. gondii infection rate in these organic pigs, prevalence of T. gondii in organically raised pigs in two establishments (Farm 1, Farm 2) in Michigan was investigated. Serum and tissue samples from 33 pigs on the farm were available for T. gondii evaluation at slaughter. Serological testing was performed using both ELISA and the modified agglutination test (MAT). Antibodies to T. gondii were detected by both ELISA and MAT in 30 of 33 animals with MAT titers of 1:25 in three, 1:50 in six, 1:100 in seven, 1:200 in 13, and 1:400 in one. Hearts of all 33 pigs were bioassayed for T. gondii in mice; T. gondii was isolated from 17 pigs including one from a seronegative (both ELISA and MAT) pig. Genetic typing of 16 of the 17 T. gondii isolates using the SAG1, SAG2, SAG3, BTUB, GRA6, c22-8, c29-2, L358, PK1 and Apico loci revealed clonal Type II from Farm 1 and clonal Type III on Farm 2. These results revealed very high prevalence of T. gondii in organic pigs for the first time in USA, indicating potentially increased health risk of consuming organic swine products. Published by Elsevier B.V.

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.

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.

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.

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.

Effect of salinity changes on the bacterial diversity, photosynthesis and oxygen consumption of cyanobacterial mats from an intertidal flat of the Arabian Gulf.

PubMed

Abed, Raeid M M; Kohls, Katharina; de Beer, Dirk

2007-06-01

The effects of salinity fluctuation on bacterial diversity, rates of gross photosynthesis (GP) and oxygen consumption in the light (OCL) and in the dark (OCD) were investigated in three submerged cyanobacterial mats from a transect on an intertidal flat. The transect ran 1 km inland from the low water mark along an increasingly extreme habitat with respect to salinity. The response of GP, OCL and OCD in each sample to various salinities (65 per thousand, 100 per thousand, 150 per thousand and 200 per thousand) were compared. The obtained sequences and the number of unique operational taxonomic units showed clear differences in the mats' bacterial composition. While cyanobacteria decreased from the lower to the upper tidal mat, other bacterial groups such as Chloroflexus and Cytophaga/Flavobacteria/Bacteriodetes showed an opposite pattern with the highest dominance in the middle and upper tidal mats respectively. Gross photosynthesis and OCL at the ambient salinities of the mats decreased from the lower to the upper tidal zone. All mats, regardless of their tidal location, exhibited a decrease in areal GP, OCL and OCD rates at salinities > 100 per thousand. The extent of inhibition of these processes at higher salinities suggests an increase in salt adaptation of the mats microorganisms with distance from the low water line. We conclude that the resilience of microbial mats towards different salinity regimes on intertidal flats is accompanied by adjustment of the diversity and function of their microbial communities.

Sunlight-induced self-healing of a microcapsule-type protective coating.

PubMed

Song, Young-Kyu; Jo, Ye-Hyun; Lim, Ye-Ji; Cho, Sung-Youl; Yu, Hwan-Chul; Ryu, Byung-Cheol; Lee, Sang-In; Chung, Chan-Moon

2013-02-01

Photopolymerization behavior of a methacryloxypropyl-terminated polydimethylsiloxane (MAT-PDMS) healing agent was investigated in the presence of benzoin isobutyl ether (BIE) photoinitiator by Fourier transform infrared (FT-IR) spectroscopy. MAT-PDMS and BIE were microencapsulated with urea-formaldehyde polymer. The surface and shell morphology of the microcapsules was investigated by scanning electron microscopy (SEM). Mean diameter and size distribution of the microcapsules could be controlled by agitation rate. A coating matrix formulation was prepared by sol-gel reaction of tetraethyl orthosilicate (TEOS) in the presence of a polysiloxane and by subsequent addition of an adhesion promoter. The formulation and microcapsules were mixed to give a self-healing coating formulation, which was then sprayed to surface of cellulose-fiber-reinforced-cement (CRC) board or mortar. Contact angle measurements showed that both the polymerized MAT-PDMS and the prepared coating matrix are hydrophobic, and the coating matrix has good wettability with MAT-PDMS. It was confirmed by optical microscopy and SEM that, when the self-healing coating is damaged, the healing agent is released from ruptured microcapsules and fills the damaged region. The self-healing coating was evaluated as protective coating for mortar, and it was demonstrated by water permeability and chloride ion penetration tests that our system has sunlight-induced self-healing capability. Our self-healing coating is the first example of capsule-type photoinduced self-healing system, and offers the advantages of catalyst-free, environmentally friendly, inexpensive, practical healing.

An Energy Balance Model to Predict Chemical Partitioning in a Photosynthetic Microbial Mat

NASA Technical Reports Server (NTRS)

Hoehler, Tori M.; Albert, Daniel B.; DesMarais, David J.

2006-01-01

Studies of biosignature formation in photosynthetic microbial mat communities offer potentially useful insights with regards to both solar and extrasolar astrobiology. Biosignature formation in such systems results from the chemical transformation of photosynthetically fixed carbon by accessory microorganisms. This fixed carbon represents a source not only of reducing power, but also energy, to these organisms, so that chemical and energy budgets should be coupled. We tested this hypothesis by applying an energy balance model to predict the fate of photosynthetic productivity under dark, anoxic conditions. Fermentation of photosynthetically fixed carbon is taken to be the only source of energy available to cyanobacteria in the absence of light and oxygen, and nitrogen fixation is the principal energy demand. The alternate fate for fixed carbon is to build cyanobacterial biomass with Redfield C:N ratio. The model predicts that, under completely nitrogen-limited conditions, growth is optimized when 78% of fixed carbon stores are directed into fermentative energy generation, with the remainder allocated to growth. These predictions were compared to measurements made on microbial mats that are known to be both nitrogen-limited and populated by actively nitrogen-fixing cyanobacteria. In these mats, under dark, anoxic conditions, 82% of fixed carbon stores were diverted into fermentation. The close agreement between these independent approaches suggests that energy balance models may provide a quantitative means of predicting chemical partitioning within such systems - an important step towards understanding how biological productivity is ultimately partitioned into biosignature compounds.

Population genetic structure and mycotoxin potential of the wheat crown rot and head blight pathogen Fusarium culmorum in Algeria.

PubMed

Laraba, Imane; Boureghda, Houda; Abdallah, Nora; Bouaicha, Oussama; Obanor, Friday; Moretti, Antonio; Geiser, David M; Kim, Hye-Seon; McCormick, Susan P; Proctor, Robert H; Kelly, Amy C; Ward, Todd J; O'Donnell, Kerry

2017-06-01

Surveys for crown rot (FCR) and head blight (FHB) of Algerian wheat conducted during 2014 and 2015 revealed that Fusarium culmorum strains producing 3-acetyl-deoxynivalenol (3ADON) or nivalenol (NIV) were the causal agents of these important diseases. Morphological identification of the isolates (n FCR=110, n FHB=30) was confirmed by sequencing a portion of TEF1. To assess mating type idiomorph, trichothecene chemotype potential and global population structure, the Algerian strains were compared with preliminary sample of F. culmorum from Italy (n=27), Australia (n=30) and the United States (n=28). A PCR assay for MAT idiomorph revealed that MAT1-1 and MAT1-2 strains were segregating in nearly equal proportions, except within Algeria where two-thirds of the strains were MAT1-2. An allele-specific PCR assay indicated that the 3ADON trichothecene genotype was predominant globally (83.8% 3ADON) and in each of the four countries sampled. In vitro toxin analyses confirmed trichothecene genotype PCR data and demonstrated that most of the strains tested (77%) produced culmorin. Global population genetic structure of 191 strains was assessed using nine microsatellite markers (SSRs). AMOVA of the clone corrected data indicated that 89% of the variation was within populations. Bayesian analysis of the SSR data identified two globally distributed, sympatric populations within which both trichothecene chemotypes and mating types were represented. Copyright © 2017. Published by Elsevier Inc.

Phylogenetic Evidence for the Existence of Novel Thermophilic Bacteria in Hot Spring Sulfur-Turf Microbial Mats in Japan

PubMed Central

Yamamoto, Hiroyuki; Hiraishi, Akira; Kato, Kenji; Chiura, Hiroshi X.; Maki, Yonosuke; Shimizu, Akira

1998-01-01

So-called sulfur-turf microbial mats, which are macroscopic white filaments or bundles consisting of large sausage-shaped bacteria and elemental sulfur particles, occur in sulfide-containing hot springs in Japan. However, no thermophiles from sulfur-turf mats have yet been isolated as cultivable strains. This study was undertaken to determine the phylogenetic positions of the sausage-shaped bacteria in sulfur-turf mats by direct cloning and sequencing of 16S rRNA genes amplified from the bulk DNAs of the mats. Common clones with 16S rDNA sequences with similarity levels of 94.8 to 99% were isolated from sulfur-turf mat samples from two geographically remote hot springs. Phylogenetic analysis showed that the phylotypes of the common clones formed a major cluster with members of the Aquifex-Hydrogenobacter complex, which represents the most deeply branching lineage of the domain bacteria. Furthermore, the bacteria of the sulfur-turf mat phylotypes formed a clade distinguishable from that of other members of the Aquifex-Hydrogenobacter complex at the order or subclass level. In situ hybridization with clone-specific probes for 16S rRNA revealed that the common phylotype of sulfur-turf mat bacteria is that of the predominant sausage-shaped bacteria. PMID:9572936

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.

Morphological signatures of microbial activity across sediment and light microenvironments of Lake Vanda, Antarctica

NASA Astrophysics Data System (ADS)

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

2017-11-01

Cyanobacteria-dominated microbial mats in Lake Vanda grow with pinnacles and ridges separated by prostrate mat. Rocks protrude over microbial mats on the lake bottom to create localized, dm-scale gradients in sedimentation and irradiance. The effects of sedimentation on pinnacle and ridge growth were isolated from photosynthetic activity by contrasting growth across microenvironmental gradients. Sedimentation rate was measured as the mass of sand and mud sized sediment in mat that accumulated over 11 years, and the incident light was modeled near and under rocks by reconstructing topography using Structure from Motion techniques. Morphologically diverse pinnacles and ridges were documented in both exposed and sheltered mat microenvironments, in addition to growing downward from the underside of overhanging rocks. Mat that grew with > 40% irradiance under overhangs did not have consistent differences in pinnacle density or ridge abundance as a function of sedimentation rates or irradiance when compared to exposed mat. However, their morphology did change significantly with changes in the direction of incident irradiance. Where irradiance was < 40% ambient or light intersected the mat at very low angles, few pinnacles were present and ridges were preferentially aligned parallel to incident light direction. These observations indicate that pinnacle nucleation and spacing were not strongly influenced by sedimentation but pinnacle and ridge morphology varied in response to directional irradiance.

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

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

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.

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.

Alternate nozzle ablative materials program

NASA Technical Reports Server (NTRS)

Kimmel, N. A.

1984-01-01

Four subscale solid rocket motor tests were conducted successfully to evaluate alternate nozzle liner, insulation, and exit cone structural overwrap components for possible application to the Space Shuttle Solid Rocket Motor (SRM) nozzle asasembly. The 10,000 lb propellant motor tests were simulated, as close as practical, the configuration and operational environment of the full scale SRM. Fifteen PAN based and three pitch based materials had no filler in the phenolic resin, four PAN based materials had carbon microballoons in the resin, and the rest of the materials had carbon powder in the resin. Three nozzle insulation materials were evaluated; an aluminum oxide silicon oxide ceramic fiber mat phenolic material with no resin filler and two E-glass fiber mat phenolic materials with no resin filler. It was concluded by MTI/WD (the fabricator and evaluator of the test nozzles) and NASA-MSFC that it was possible to design an alternate material full scale SRM nozzle assembly, which could provide an estimated 360 lb increased payload capability for Space Shuttle launches over that obtainable with the current qualified SRM design.

Microbial mat of the thermal springs Kuchiger Republic of Buryatia: species composition, biochemical properties and electrogenic activity in biofuel cell

NASA Astrophysics Data System (ADS)

Aleksandrovich Yuriev, Denis; Viktorovna Zaitseva, Svetlana; Olegovna Zhdanova, Galina; Yurievich Tolstoy, Mikhail; Dondokovna Barkhutova, Darima; Feodorovna Vyatchina, Olga; Yuryevna Konovalova, Elena; Iosifovich Stom, Devard

2018-02-01

Electrogenic, molecular and some other properties of a microbial mat isolated from the Kuchiger hot spring (Kurumkansky District, Republic of Buryatia) were studied. Molecular analysis showed that representatives of Proteobacteria (85.5 % of the number of classified bacterial sequences) prevailed in the microbial mat of the Kuchiger springs, among which sulfur bacteria of the genus Thiothrix were the most numerous. In the microbial mat there were bacteria from the families Rhodocyclaceae, Comamonadaceae and Flavobacteriaceae. Phylum Bacteroidetes, Cyanobacteria/Chloroplast, Fusobacteria, Fibrobacteres, Acidobacteria, Chlorobi, Spirochaetes, Verrucomicrobia, Firmicutes, Deinococcus-Thermus, Chloroflexi and Actinobacteria are also noted in the composition of the microbial mat. Under the experimental conditions using Kuchiger-mat 16 as bioagents, glucose and peptone as substrates, the power of BFC was 240 and 221 mW / m2, respectively. When replacing the substrate with sodium acetate, the efficiency of the BFC was reduced by a factor of 10 (20 mW / m2). The prospects of using a microbial mat “Kuchiger-16” as an electrogen in BFC when utilizing alkaline waste water components to generate electricity are discussed.

Measured and predicted structural behavior of the HiMAT tailored composite wing

NASA Technical Reports Server (NTRS)

Nelson, Lawrence H.

1987-01-01

A series of load tests was conducted on the HiMAT tailored composite wing. Coupon tests were also run on a series of unbalanced laminates, including the ply configuration of the wing, the purpose of which was to compare the measured and predicted behavior of unbalanced laminates, including - in the case of the wing - a comparison between the behavior of the full scale structure and coupon tests. Both linear and nonlinear finite element (NASTRAN) analyses were carried out on the wing. Both linear and nonlinear point-stress analyses were performed on the coupons. All test articles were instrumented with strain gages, and wing deflections measured. The leading and trailing edges were found to have no effect on the response of the wing to applied loads. A decrease in the stiffness of the wing box was evident over the 27-test program. The measured load-strain behavior of the wing was found to be linear, in contrast to coupon tests of the same laminate, which were nonlinear. A linear NASTRAN analysis of the wing generally correlated more favorably with measurements than did a nonlinear analysis. An examination of the predicted deflections in the wing root region revealed an anomalous behavior of the structural model that cannot be explained. Both hysteresis and creep appear to be less significant in the wing tests than in the corresponding laminate coupon tests.

MAT Program Test Summary Report. Biconic Body with Slice/Flap

DTIC Science & Technology

1982-01-01

with a six-component internal strain -gage balances using conventional foil and semiconductor gages. Balance details are described in Reference 1. The...115. Smk TABLE 13. TEST DATA SUMMARY 10,50/70 SLICED BICONE WITH FLAP M. =8 Re. = 3.7 x10 6/ft a. Force and Moment Data RN" TRIP HT." SLICES so 1

Seroprevalence of Toxoplasma gondii infection in captive mammals in three zoos in Mexico City, Mexico

USDA-ARS?s Scientific Manuscript database

Antibodies to Toxoplasma gondii were determined in 167 mammals in 3 zoos in Mexico City, Mexico using the modified agglutination test (MAT). Overall, antibodies to T. gondii were found in 89 (53.3%) of the 167 animals tested. Antibodies were found in 35 of 43 wild Felidae: 2 of 2 bobcats (Lynx rufus...

Integrating shotcrete walls into the natural landscape by application of 'Green Walls'

NASA Astrophysics Data System (ADS)

Medl, Alexandra; Kikuta, Silvia

2017-04-01

Steep slopes resulting from major road infrastructure constructions are increasingly perceived as disagreeable disturbance in the landscape. Thus, a tool to consider landscape aspects and integrate these slopes into the natural environment is required. The challenge is to establish a sustainable vegetation layer despite of adverse circumstances such as inclinations of almost 90⁰, exposed position of slopes near streets and lack of soil and water supply. The objective of this study was to assess the performance of an innovative greening technology for vertical structures (shotcrete wall) in terms of vegetation development on varying plant substrates and geotextiles. The field experiment in Steinach am Brenner, Tyrol, Austria, included testing three plant substrates on basis of nearby rocky excavation material ('Innsbrucker Quarzphyllit', 'Bündnerschiefer' and 'Zentralgneis') combined with compost. Additionally, five geotextiles (geogrid (3x4 mm), geogrid (9x10 mm), coir net, coir mat, geo mat) were applied for evaluation. All test combinations were evaluated regarding vegetation cover and biomass production from 2015 to 2016. Analyses of chemical properties were conducted for all plant substrates. Results showed highest vegetation cover ratio on 'Bündnerschiefer' and 'Innsbrucker Quarzphyllit', which can be explained by the favorable mineral composition (nutrient storage capacity) and chemical properties of compost (lower values of electrical conductivity and C/N ratio). In conclusion, the use of 'Green Walls' filled with 'Bündnerschiefer' or 'Innsbrucker Quarzphyllit' plant substrate in combination with netlike geotextiles proved best, since geo grid and coir net turned out as most successful one year after installation. 'Green Walls' are promising in terms of establishing an optimal vegetation cover on vertical structures and are well suited for integrating shotcrete walls into the landscape. The use of local excavation material for greening purposes can be confirmed, whereby the admixture of high-quality compost is necessary to guarantee satisfying results.

Biogeochemistry of hypersaline microbial mats illustrates the dynamics of modern microbial ecosystems and the early evolution of the biosphere

NASA Technical Reports Server (NTRS)

Des Marais, David J.

2003-01-01

Photosynthetic microbial mats are remarkably complete self-sustaining ecosystems at the millimeter scale, yet they have substantially affected environmental processes on a planetary scale. These mats may be direct descendents of the most ancient biological communities in which even oxygenic photosynthesis might have developed. Photosynthetic mats are excellent natural laboratories to help us to learn how microbial populations associate to control dynamic biogeochemical gradients.

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.

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.

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.

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 be very similar and likely functionally related. Our experimental field data were used for modelling water flow and solute transport in floating fens, using HYDRUS 2D. Fluctuations of surface water and root mat, as well as geometry and unsaturated zone parameters can have a major influence on groundwater fluctuations and the exchange between rain and surface water and the water in the root mats. In combination with the duration of salt pulses in surface water, and sensitivity of fen plants to salinity (Stofberg et al. 2014, submitted), risks for rare plants can be anticipated.

Insights into the Processing of Carbon by Early Microbial Ecosystems

NASA Technical Reports Server (NTRS)

DesMarais, D.; Bebout, B.; Carpenter, S.; Discipulo, S.; Londry, K.; Habicht, K.; Turk, K.

2003-01-01

Interactions between Earth and the biosphere that were crucial for early biological evolution also influenced substantially the processes that circulate C between its reservoirs in the atmosphere, ocean, crust and mantle. The C-13 C-12 values of crustal carbonates and organics have recorded changes both in biological discrimination and in the relative rates of burial of organics and carbonates. A full interpretation of these patterns needs further isotopic studies of microbial ecosystems and individual anaerobes. Thus we measured carbon isotope discrimination during autotrophic and heterotrophic growth of pure cultures of sulfate-reducing bacteria and archaea (SRB and SRA). Discrimination during CO2 assimilation is significantly larger than during heterotrophic growth on lactate or acetate. SRB grown lithoautotrophically consumed less than 3% of available CO2 and exhibited substantial discrimination, as follows: Desulfobacterium autotrophicum (alpha 1.0100 to 1.0123), Desulfobacter hydrogenophilus (alpha = 0.0138), and Desulfotomuculum acetoxidans (alpha = 1.0310). Mixotrophic growth of Desulfovibrio desulfuricans on acetate and CO2 resulted in biomass with delta C-13 composition intermediate to that of the substrates. We have recently extended these experiments to include the thermophilic SRA Archeoglobus spp. Ecological forces also influence isotopic discrimination. Accordingly, we quantified the flow of C and other constituents in modern marine cyanobacterial mats, whose ancestry extends back billions of years. Such ecosystem processes shaped the biosignatures that entered sediments and atmospheres. At Guerrero Negro, BCS, Mexico, we examined mats dominated by Microcoleus (subtidal) and Lyngbya (intertidal to supratidal) cyanobacteria. During 24 hour cycles, we observed the exchange of O2 and dissolved inorganic C (DIC) between mats and the overlying water. Microcoleus mats assimilated near-equal amounts of DIC during the day as they released at night, but Lyngbya mats typically showed net uptake of DIC over the diel cycle. Patterns of O2 daytime release and nighttime uptake mirrored these DIC trends in both mat types. Nighttime DIC effluxes from Microcoleus mats were equivalent in the presence versus absence of O2, whereas nighttime DIC effluxes from Lyngbya mats dropped markedly in the absence of O2. Thus aerobic diagenesis was more important in Lyngbya mats than in Microcoleus mats, perhaps because trapped O2 bubbles persist only in Lyngbya mats at night and thus sustain populations of aerbes. In both mat types, effluxes of H2, CH4 and short-chain fatty acids were much greater at night in the absence of 02, emphasizing the importance of fermentation. Differences observed between Microcoleus versus Lyngbya mats forecast differences in their microbial populations and in their patterns of gene expression.

SEROLOGICAL AND MOLECULAR SURVEY OF Leptospira spp. AMONG CART HORSES FROM AN ENDEMIC AREA OF HUMAN LEPTOSPIROSIS IN CURITIBA, SOUTHERN BRAZIL

PubMed Central

Finger, Mariane Angélica; de Barros, Ivan Roque; Leutenegger, Christian; Estrada, Marko; Ullmann, Leila Sabrina; Langoni, Hélio; Kikuti, Mariana; Dornbush, Peterson Triches; Deconto, Ivan; Biondo, Alexander Welker

2014-01-01

Introduction: Cart horses are a re-emerging population employed to carry recyclable material in cities. Methods: Sixty-two horses were sampled in an endemic area of human leptospirosis. The microscopic agglutination test (MAT) and real-time polymerase chain reaction (qPCR) were performed. Results: A seropositivity of 75.8% with serovar Icterohaemorrhagiae in 80.8% of the horses was observed. Blood and urine were qPCR negative. MAT showed positive correlations with rainfall (p = 0.02) and flooding (p = 0.03). Conclusions: Although horses may be constantly exposed to Leptospira spp. in the environment mostly because of rainfall and flooding, no leptospiremia or leptospiruria were observed in this study. PMID:25351539

Information yield: a comparison of Kodak T-Mat G, Ortho L and RP X-Omat films.

PubMed

Miles, D A; Van Dis, M L; Peterson, M G

1989-02-01

The information yield from two rare-earth screen-film combinations, Lanex Regular/T-Mat G (TMG) and Lanex regular/Ortho L (OL) has been compared with that from a conventional calcium-tungstate combination, X-Omatic regular/RP X-Omat (XRP), by means of perceptibility curves generated from an aluminum test object. The TMG and OL systems were faster than the XRP and the OL had the widest latitude. The maximum number of details perceived was similar for all three systems. The results support the suggestion that the TMG and OL systems permit more information to be perceived than XRP and that the newer imaging systems do not lose information despite their increased speed.

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

Ignavibacterium album gen. nov., sp. nov., a moderately thermophilic anaerobic bacterium isolated from microbial mats at a terrestrial hot spring and proposal of Ignavibacteria classis nov., for a novel lineage at the periphery of green sulfur bacteria.

PubMed

Iino, Takao; Mori, Koji; Uchino, Yoshihito; Nakagawa, Tatsunori; Harayama, Shigeaki; Suzuki, Ken-Ichiro

2010-06-01

A moderately thermophilic chemoheterotrophic bacterium, strain Mat9-16(T), was isolated from microbial mats developed in hot spring water streams from Yumata, Nagano, Japan. Cells of strain Mat9-16(T) were strictly anaerobic, Gram-stain-negative, non-sporulating, non-motile and short to long rods (2.0-15.5 mum in length). Strain Mat9-16(T) grew fermentatively with optimum growth at 45 degrees C, pH 7.0-7.5 and 1 % NaCl (w/v). Phylogenetic analysis based on the 16S rRNA gene revealed that strain Mat9-16(T) was affiliated with an uncultivated lineage, and the nearest cultivated neighbours were green sulfur bacteria belonging to the class Chlorobea with 77-83 % sequence similarity. However, strain Mat9-16(T) could not grow phototrophically and did not possess light-harvesting structures, morphologically and genetically, such as the chlorosomes of green sulfur bacteria. On the basis of phenotypic features and phylogenetic position, a novel genus and species are proposed for strain Mat9-16(T), to be named Ignavibacterium album gen. nov., sp. nov. (=NBRC 101810(T) =DSM 19864(T)). We also propose to place the cultivated bacterial lineage accommodating the sole representative Mat9-16(T) in a novel class, Ignavibacteria classis nov. In addition, we present a formal description of the phylum-level taxon 'Chlorobi' as Chlorobi phyl. nov.

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

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.

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

Vínculos sobre um modelo de quartessência de Chaplygin usando observações do satélite chandra da fração de massa de gás em aglomerados de galáxias

NASA Astrophysics Data System (ADS)

de Souza, R. S.

2003-08-01

Observações de Supernovas do tipo Ia mostram que a expansão do Universo está acelerando. Segundo as equações de Einstein uma componente com pressão negativa (energia escura) é necessária para explicar a aceleração cósmica. Além da energia escura é usualmente admitido que no Universo há também uma matéria exótica com pressão zero, que é chamada de matéria escura. Essa componente possui um papel fundamental na formação de estruturas no Universo. Recentemente tem se explorado a possibilidade de que matéria e energia escura poderiam ser unificadas através de uma única componente, que tem sido denominada de quartessência. Um exemplo de fluido com essas características é o Gás de Chaplygin Generalizado, que possui uma equação de estado da forma p = -A/ra. Inicialmente consideramos o caso especial a = 1 (gás de Chaplygin) e vinculamos parâmetros do modelo utilizando observações em raios-X do satélite Chandra da fração de massa de gás em aglomerados de galáxias. Uma comparação dos vínculos obtidos com esse teste com outros testes, tais como supernovas e idade do Universo, mostra que esse teste é bastante restritivo. Exibiremos ainda resultados para o caso em que a curvatura é nula e o parâmetro a está compreendido no intervalo -1 < a 1.

Étude de la réponse photoacoustique d'objets massifs en 3D

NASA Astrophysics Data System (ADS)

Séverac, H.; Mousseigne, M.; Franceschi, J. L.

1996-11-01

In some sectors such as microelectronics or the physics of materials, reliability is of capital importance. It is also particularly attractive to have access on informations on the material behaviour without the use of a destructive test like chemical analysis or others mechanical tests. The submitted method for non-destructive testing is based on the waves generation with a laser beam. The aim of studying the various waves in the three-dimensional space is to bring informations about materials response. Thermoelastic modelisation allowed a rigorous analytic approach and to give rise to a software written in Turbo-Pascal for a more general solution. Dans les secteurs où la fiabilité est capitale, tels la micro-électronique ou la physique des matériaux, il est particulièrement utile d'accéder aux informations sur le comportement du matériau sans avoir à utiliser une méthode destructive (analyses chimiques ou autres essais mécaniques). La méthode de contrôle non destructif présentée est basée sur la génération d'ondes par impact d'un faisceau laser focalisé à la surface d'un échantillon, sans atteindre le régime d'ablation. L'étude de la propagation des diverses ondes dans l'espace tridimensionnel permet d'apporter des mesures quantitatives sur l'analyse de la réponse des matériaux utilisés. La modélisation des phénomènes thermoélastiques a permis une approche analytique rigoureuse et donné naissance à un logiciel de simulation écrit en Turbo-Pascal pour des études plus générales.

Comparison of commercial ELISA tests for the detection of Toxoplasma antibodies in the meat juice of naturally infected pigs.

PubMed

Felin, Elina; Näreaho, Anu; Fredriksson-Ahomaa, Maria

2017-04-30

Toxoplasmosis is a globally distributed protozoal zoonosis. Pigs are considered an important reservoir of Toxoplasma gondii and pork a major infection source of human toxoplasmosis. ELISA methods are commonly used diagnostic tools for detecting Toxoplasma infections. They are also used for slaughterhouse-based serological monitoring of toxoplasmosis in pigs to identify positive farms. The methods used are non-standardised with varying sensitivity and specificity. In our study, four commercial ELISA tests for the detection of Toxoplasma antibodies in the meat juice of slaughter pigs were compared with a modified agglutination test (MAT) as a reference. The cut-off values of the ELISA tests provided by the manufacturer varied between 0.20 and 0.50, and clearly influenced prevalence. The sensitivity of tests I, II and III varied between 96.4 and 78.6. Sensitivity was unacceptably low (3.6) for test IV (cut-off=0.30). Tests I, II and III had the highest accuracy and the best agreement with the reference test when a cut-off of 0.30 was used. Test II and III showed very good agreement (K=0.92 and 0.84, respectively) with the MAT. A very strong correlation (Pearson correlation >0.89) was observed between the S/P values of tests I, II and III. Our results demonstrate that the test and cut-off value used influence the results of the apparent seroprevalence studies. Copyright © 2017 Elsevier B.V. All rights reserved.