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Microscopic agglutination test on captive rattlesnakes : Data on serovars and titers

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T.C.S. Rodrigues

2016-06-01

Full Text Available The microscopic agglutination test (MAT is considered the “golden standard” leptospirosis serodiagnostic test, but there is little information about it as it pertains to snakes. To fill this information gap, we provide data on serovars and titers of fifty-six Crotalus durissus collilineatus sera samples that tested positive by MAT (10.1016/j.actatropica.2016.02.006 (Rodrigues et al., 2016 [5]. These data are presented in a table, along with a description of the methodology used for sample collection and serologic testing.
Reverse-Transcriptase PCR Detection of Leptospira: Absence of Agreement with Single-Specimen Microscopic Agglutination Testing.

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Waggoner, Jesse J; Balassiano, Ilana; Mohamed-Hadley, Alisha; Vital-Brazil, Juliana Magalhães; Sahoo, Malaya K; Pinsky, Benjamin A

2015-01-01

Reference diagnostic tests for leptospirosis include nucleic acid amplification tests, bacterial culture, and microscopic agglutination testing (MAT) of acute and convalescent serum. However, clinical laboratories often do not receive paired specimens. In the current study, we tested serum samples using a highly sensitive real-time nucleic acid amplification test for Leptospira and compared results to MAT performed on the same specimens. 478 serum samples from suspected leptospirosis cases in Rio de Janeiro were tested using a real-time RT-PCR for the diagnosis of leptospirosis, malaria and dengue (the Lepto-MD assay). The Lepto-MD assay detects all species of Leptospira (saprophytic, intermediate, and pathogenic), and in the current study, we demonstrate that this assay amplifies both Leptospira RNA and DNA. Dengue virus RNA was identified in 10 patients, and no cases of malaria were detected. A total of 65 samples (13.6%) were positive for Leptospira: 35 samples (7.3%) in the Lepto-MD assay, 33 samples (6.9%) by MAT, and 3 samples tested positive by both (kappa statistic 0.02). Poor agreement between methods was consistent regardless of the titer used to define positive MAT results or the day of disease at sample collection. Leptospira nucleic acids were detected in the Lepto-MD assay as late as day 22, and cycle threshold values did not differ based on the day of disease. When Lepto-MD assay results were added to the MAT results for all patients in 2008 (n=818), the number of detected leptospirosis cases increased by 30.4%, from 102 (12.5%) to 133 (16.3%). This study demonstrates a lack of agreement between nucleic acid detection of Leptospira and single-specimen MAT, which may result from the clearance of bacteremia coinciding with the appearance of agglutinating antibodies. A combined testing strategy for acute leptospirosis, including molecular and serologic testing, appears necessary to maximize case detection.
A comparison of titers of anti-Brucella antibodies of naturally infected and healthy vaccinated cattle by standard tube agglutination test, microtiter plate agglutination test, indirect hemagglutination assay, and indirect enzyme-linked immunosorbent assay

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Anju Mohan

2016-07-01

Full Text Available Aim: We determined the antibody response in cattle naturally infected with brucellosis and normal healthy adult cattle vaccinated during calf hood with strain 19. Materials and Methods: The antibody titers were measured by standard tube agglutination test (STAT, microtiter plate agglutination test (MAT, indirect hemagglutination assay (IHA, and indirect enzyme-linked immunosorbent assay (iELISA as per standard protocols. Results: The mean STAT titers were 1.963±0.345 in infected cattle and 1.200±0.155 in healthy vaccinated cattle. The difference was extremely significant (p<0.0001. The mean MAT titers were 2.244±0.727 in infected cattle and 1.200±0.155 in healthy vaccinated cattle. The difference was very significant (p<0.005. The mean IHA titers in infected cattle were 2.284±0.574, and those in healthy vaccinated cattle were 1.200±0.155. The difference was extremely significant (p=0.0002. However, the difference in mean iELISA titers of infected cattle (1.3678±0.014 and healthy vaccinated cattle (1.367±0.014 was non-significant. The infected animals showed very high titers of agglutinating antibodies compared to the vaccinated animals. However, it cannot be ascertained whether these antibodies are due to vaccine or response to infection. Since the infected animals had been vaccinated earlier, the current infection may suggest that vaccination was unable to induce protective levels of antibody. The heightened antibody response after infection may also indicate a secondary immune response to the antigens common to the vaccine strain and wild Brucella organisms. Conclusion: The brucellosis infected animals showed very high titers of agglutinating antibodies compared to the vaccinated animals.
Agglutinating antibodies against pathogenic Leptospira in healthy dogs and horses indicate common exposure and regular occurrence of subclinical infections

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D.J. Houwers; M.G.A. Goris (Marga); T.H. Abdoel (Theresia); J.A. Kas (Jeroen); S.S. Knobbe (Sandra); A.M. van Dongen (Astrid); F.E. Westerduin (Fenna); W.R. Klein (Wim); R.A. Hartskeerl (Rudy)

2011-01-01

textabstractIn order to get insight in the level of exposure to pathogenic Leptospira under the moderate sea climate conditions in the Netherlands, healthy dogs and horses were tested for antibodies using the Microscopic Agglutination Test (MAT). 55% of 198 dogs tested had agglutinating antibodies
Clinical manifestation, serology marker & microscopic agglutination test (MAT) to mortality in human leptospirosis

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

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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.
Comparison of agglutinating and neutralizing antibodies to serovar hardjo in sows immunized with two commercial whole culture polivalent anti-leptospira bacterins

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Soto, Francisco Rafael Martins; Pinheiro, Sônia Regina; Morais, Zenaide Maria; Gonçales, Amane Paldês; de Azevedo, Sérgio Santos; Bernardi, Fernanda; Camargo, Sebastião Rodrigues; Vasconcellos, Silvio Arruda

2008-01-01

It was performed the comparison of the intensity and duration of agglutinating and neutralizing antibodies to serovar Hardjo in swines vaccinated with two commercial anti-leptospira bacterins. Sows no reactive to 24 Leptospira sp serovars in the microscopic agglutination test (MAT) were divided in three groups: Group A (n=08): received two vaccine A doses with 30 days interval, Group B (n=08) two vaccine B doses with 30 days interval and Group C (n=08): control no vaccinated against leptospirosis.Blood samples were collected each 30 days during six months following the first vaccination. The sera were tested by MAT and growth inhibition test (GIT) to serovar Hardjo in order to evaluate respectively agglutinating and neutralizing antibodies. It was found that neutralizing antibodies persisted for a longer time than the agglutinating ones and that the absence of agglutinating antibodies does not means in the absence of the neutralizing. The peaks of agglutinating antibodies was obtained at least 30 days earlier than that produced by neutralizing. The duration of both kinds of antibodies measured differed between the two bacterines tested. The period for inducing neutralizing antibodies against serovar Hardjo indicated that gilts must be immunized with two doses of whole culture anti-leptospira bacterines applied 30 days each other at least 90 days before the first mating. For the maintenance of hight levels of neutralizing antibodies the revaccinations must be performed every six months after the first vaccination. PMID:24031250
Application of direct agglutination test (DAT) and fast agglutination screening test (FAST) for sero-diagnosis of visceral leishmaniasis in endemic area of Minas Gerais, Brazil

NARCIS (Netherlands)

Silva, Eduardo S.; Schoone, Gerard J.; Gontijo, Celia M. F.; Brazil, Reginaldo P.; Pacheco, Raquel S.; Schallig, Henk D. F. H.

2005-01-01

The direct agglutination test (DAT) has proved to be a very important sero-diagnostic tool combining high levels of intrinsic validity and ease of performance. Otherwise, fast agglutination screening test (FAST) utilises only one serum dilution making the test very suitable for the screening of
Evaluation of the Leptospira species microscopic agglutination test in experimentally vaccinated cats and Leptospira species seropositivity in aged azotemic client-owned cats.

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Shropshire, Sarah B; Veir, Julia K; Morris, Arianne K; Lappin, Michael R

2016-10-01

The objectives of this study were to validate the microscopic agglutination test (MAT) using feline sera, determine cross-reactivity of Borrelia burgdorferi antibodies in the MAT, and evaluate if there is an association between Leptospira species seropositivity in aged (⩾10 years) client-owned cats with and without azotemia (creatinine >2 g/dl). A four-serovar canine leptospiral vaccine was administered to two specific pathogen-free (SPF) cats on days 0 and 14. The MAT was performed intermittently until day 42 for the serovars Canicola, Grippotyphosa, Hardjo, Icterohaemorrhagiae, Pomona and Bratislava, with a cut-off value of ⩾1:100. Five purpose-bred cats were infested with wild-caught Ixodes scapularis adults with an average B burgdorferi infection rate of 50%, and tested for antibodies against B burgdorferi C6 peptide and DNA in skin biopsies, as well as by MAT. Sera from 66 azotemic and 75 non-azotemic cats ⩾10 years of age were tested for Leptospira species antibodies using the MAT and results were compared by the χ(2) test. Both SPF cats seroconverted by week 3 and formed antibodies against at least one serovar. There was no cross-reactivity in the MAT using samples from cats with antibodies to B burgdorferi. MAT results were positive for 4/66 azotemic cats and 8/75 non-azotemic cats; these results were not statistically different. The MAT can be interpreted using feline serum and does not appear to cross-react in cats with B burgdorferi antibodies. There was no association between Leptospira species MAT results and azotemia in this group of aged client-owned cats but further studies are needed to determine if leptospirosis contributes to feline chronic kidney disease. © The Author(s) 2015.
MAT FOR LEPTOSPIROSIS DIAGNOSIS

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Esti Rahardianingtyas.

2014-06-01

Full Text Available Leptospirosis is a disease caused by bacterial infection leptospira interrogans.Leptospira bacteria is a spiral bacterium with solid strands with two flagella periplasmik.Septicaemic phase patient samples taken from the blood and cerebrospinal fluid, whereassamples taken at phase immune extracted from urine. The diagnosis of leptospirosis occurdirectly or indirectly. Diagnosis is done by directly isolate and identify the causative agents ofthe agent. Diagnosis is done indirectly by detecting specific antibodies from the patient's body.Gold Standard of the diagnosis of leptospirosis is MAT. Mat made by reacting antibodies toleptospira antigen. Positive results seen with clump formed.Key words: Leptospirosis, Leptospirosis Diagnostic, MAT (Microscopic Agglutination Test Leptospirosis merupakan penyakit yang disebabkan karena infeksi bakteri leptospirainterrogans. Bakteri leptospira merupakan bakteri spiral dengan untaian yang padat dengan duaflagella periplasmik. Sampel pasien pada fase septicaemic diambil dari darah dan cairanserebrospinal, sedangkan sampel yang diambil pada fase immune diambil dari urine. Diagnosisleptospirosis dilakukan secara langsung maupun tidak langsung. Diagnosis secara langsungdilakukan dengan cara mengisolasi agen penyebab dan mengidentifikasi agen tersebut. Diagnosissecara tidak langsung dilakukan dengan cara mendeteksi antibodi spesiflk dari dalam tubuhpasien. Gold Standart dari diagnosis leptospirosis adalah MAT. Mat dilakukan dengan caramereaksikan antibodi dengan antigen leptospira. Hasil positif dilihat dengan terbentuk gumpalanagglutinasiKata kunci: Leptospirosis, Leptospira, Leptospirosis Diagnosis.
Microbead agglutination based assays

KAUST Repository

Kodzius, Rimantas

2013-01-21

We report a simple and rapid room temperature assay for point-of-care (POC) testing that is based on specific agglutination. Agglutination tests are based on aggregation of microbeads in the presence of a specific analyte thus enabling the macroscopic observation. Such tests are most often used to explore antibody-antigen reactions. Agglutination has been used for protein assays using a biotin/streptavidin system as well as a hybridization based assay. The agglutination systems are prone to selftermination of the linking analyte, prone to active site saturation and loss of agglomeration at high analyte concentrations. We investigated the molecular target/ligand interaction, explaining the common agglutination problems related to analyte self-termination, linkage of the analyte to the same bead instead of different microbeads. We classified the agglutination process into three kinds of assays: a two- component assay, a three-component assay and a stepped three- component assay. Although we compared these three kinds of assays for recognizing DNA and protein molecules, the assay can be used for virtually any molecule, including ions and metabolites. In total, the optimized assay permits detecting analytes with high sensitivity in a short time, 5 min, at room temperature. Such a system is appropriate for POC testing.
Microbead agglutination based assays

KAUST Repository

Kodzius, Rimantas; Castro, David; Foulds, Ian G.; Parameswaran, Ash M.; Sumanpreet, K. Chhina

2013-01-01

We report a simple and rapid room temperature assay for point-of-care (POC) testing that is based on specific agglutination. Agglutination tests are based on aggregation of microbeads in the presence of a specific analyte thus enabling
Latex agglutination test (LAT) for the diagnosis of typhoid fever.

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Sahni, Gopal Shankar

2013-06-01

The efficacy of latex agglutination test in the rapid diagnosis of typhoid fever was studied and the result compared with that of blood culture. This study included 80 children suffering from typhoid fever, among which 40 were confirmed by blood culture isolation and 40 had possible typhoid fever based on high Widal's titre (a four-fold rise in the titre of antibody to typhi "O" and "H" antigen was considered as a positive Widal's test result). Eighty children, 40 with febrile illness confirmed to be other than typhoid and 40 normal healthy children were used as negative controls. The various groups were: (i) Study group ie, group I had 40 children confirmed by culture isolation of Salmonella typhi(confirmed typhoid cases). (ii) Control groups ie, (a) group II with 40 febrile controls selected from paediatrics ward where cause other than S typhi has been established, (b) group III with 40 afebrile healthy controls that were siblings of the children admitted in paediatric ward for any reason with no history of fever and TAB vaccination in the last one year, and (c) group IV with 40 children with high Widal's titre in paired sera sample. Widal's test with paired sera with a one week interval between collections were done in all 40 patients. Latex aggtutination test which could detect 900 ng/ml of antigen as observed in checker board titration, was positive in all 40 children from group I who had positive blood culture and in 30 children from group IV who had culture negative and had high Widal's titre positive. Latex agglutination test was positive in 4 children in group II and none in group III. Using blood culture positive cases as true positive and children in groups II and III as true negative, the test had a sensitivity of 100% and specificity of 96%. Latex agglutination test was found to be significantly sensitive (100%) and specific (96%) and could detect 75% more cases in group IV (possible typhoid cases). Thus latex agglutination test can be used for rapid
Comparison of agglutination test, microscopy and nPCR for ...

African Journals Online (AJOL)

action (nPCR) for the detection of T. gondii infection in mice (n=399) inoculated with heart .... Direct Agglutination Test (DAT) (Toxo screen DA, Biomerieux®, France) fol- ... 0.3 µl external forward Primer (50 µM), 0.3 µl external reverse Primer.
Development of a fast agglutination screening test (FAST) for the detection of anti-Leishmania antibodies in dogs

NARCIS (Netherlands)

Schallig, H. D. F. H.; Schoone, G. J.; Beijer, E. G. M.; Kroon, C. C. M.; Hommers, M.; Ozbel, Y.; Ozensoy, S.; da Silva, E. S.; Cardoso, L. M.; da Silva, E. D.

2002-01-01

A fast agglutination screening test (FAST) for the detection of anti-Leishinania antibodies in serum samples from dogs with visceral leishmamosis was developed. The test is based on the direct agglutination test (DAT), but combines a higher parasite concentration with a smaller test volume. In
Serotyping of Actinobacillus pleuropneumoniae serotype 5 strains using a monoclonal-based polystyrene agglutination test

DEFF Research Database (Denmark)

Dubreuil, J.D.; Letellier, A.; Stenbæk, Eva

1996-01-01

A polystyrene agglutination test has been developed for serotyping Actinobacillus pleuropneumoniae serotype 5a and 5b strains. Protein A-coated polystyrene microparticles were sensitized with a murine monoclonal antibody recognizing an epitope on serotype 5 LPS-O chain as shown by SDS-PAGE and We......A polystyrene agglutination test has been developed for serotyping Actinobacillus pleuropneumoniae serotype 5a and 5b strains. Protein A-coated polystyrene microparticles were sensitized with a murine monoclonal antibody recognizing an epitope on serotype 5 LPS-O chain as shown by SDS...... suspension of bacterial cells grown for 18 h. All A, pleuropneumoniae strains had been previously serotyped using standard procedures, The polystyrene agglutination test was rapid (less than 3 min) and easy to perform. Overall a very good correlation (97.3%) with the standard techniques was found...
Typhoid fever in a Tertiary Hospital in Nigeria: Another look at the Widal agglutination test as a preferred option for diagnosis.

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Enabulele, Osahon; Awunor, Simeon Nyemike

2016-01-01

Single Widal agglutination test rather than blood culture, is commonly employed to diagnose typhoid fever in Nigeria. We took another look at the Widal agglutination test as a preferred option for diagnosis of typhoid fever by determining the specificity and sensitivity of Widal agglutination test in febrile adult patients. Two hundred and seventy-one blood samples from consecutive adults (>18 years) with febrile illness attending the General Practice Clinic of the University of Benin Teaching Hospital were tested using the Widal agglutination test, blood culture, and malaria parasite test on each sample to establish the diagnosis of typhoid fever. Of the 271 blood samples 124 (45.76%) were positive following a Widal agglutination test, 60 (22.10%) blood samples grew Salmonella organisms on blood culture while 55 (20.29%) blood samples showed a co-infection of typhoid fever and malaria. A sensitivity of 35%, specificity of 51%, positive predictive value of 17%, and a negative predictive value of 73% were observed for Widal agglutination test as a diagnostic modality for typhoid fever infection. A single Widal agglutination test is not a valid diagnostic option for typhoid fever while co-infection with malaria parasite is the preponderant microbiological finding in typhoid fever infections. The severity of malaria parasitemia is associated with positive titers on Widal test.
DNA & Protein detection based on microbead agglutination

KAUST Repository

Kodzius, Rimantas

2012-06-06

We report a simple and rapid room temperature assay for point-of-care (POC) testing that is based on specific agglutination. Agglutination tests are based on aggregation of microparticles in the presence of a specific analyte thus enabling the macroscopic observation. Agglutination-based tests are most often used to explore the antibody-antigen reactions. Agglutination has been used for mode protein assays using a biotin/streptavidin two-component system, as well as a hybridization based two-component assay; however, as our work shows, two-component systems are prone to self-termination of the linking analyte and thus have a lower sensitivity. Three component systems have also been used with DNA hybridization, as in our work; however, their assay requires 48 hours for incubation, while our assay is performed in 5 minutes making it a real candidate for POC testing. We demonstrate three assays: a two-component biotin/streptavidin assay, a three-component hybridization assay using single stranded DNA (ssDNA) molecules and a stepped three-component hybridization assay. The comparison of these three assays shows our simple stepped three-component agglutination assay to be rapid at room temperature and more sensitive than the two-component version by an order of magnitude. An agglutination assay was also performed in a PDMS microfluidic chip where agglutinated beads were trapped by filter columns for easy observation. We developed a rapid (5 minute) room temperature assay, which is based on microbead agglutination. Our three-component assay solves the linker self-termination issue allowing an order of magnitude increase in sensitivity over two–component assays. Our stepped version of the three-component assay solves the issue with probe site saturation thus enabling a wider range of detection. Detection of the agglutinated beads with the naked eye by trapping in microfluidic channels has been shown.
Rapid detection of microalbuminuria in diabetic patients by an agglutination inhibition test

International Nuclear Information System (INIS)

Giampietro, O.; Miccoli, R.; Di Palma, L.; Bertolotto, A.; Anichini, R.; Navalesi, R.; Clerico, A.

1986-01-01

Subclinical elevation of urinary albumin excretion (UAlbE) early in the course of diabetes mellitus has been suggested to predict later clinical proteinuria and mortality. UAlbE is currently measured using radioimmunoassay (RIA) or radial immunodiffusion methods. However, these procedures are expensive and time-consuming and cannot be used as screening methods. Recently, an agglutination test (AT) has been suggested as a routinary method for the screening of microalbuminuria in diabetic patients. In this paper the results obtained are compared with an AT procedure and RIA method in a screening program of microproteinuria in diabetic patients. An immunological test (a latex agglutination assay) for the analysis of albuminura is used, which human albumin was adsorbed to latex beads (about 0.3 μl of a urine sample. Urine samples containing an albumin concentration >40 μg/ml were found to inhibit the agglutination of latex beads with antiserum. The RIA and AT results showed good agreement when urine samples were assayed soon after collection or after a short period of storage (≤3 weeks at -20 grade centigrades). The AT procedure has been adjusted in order to give a positive response (no agglutination) over the range of supranormal concentrations of urinary albumin (>40 μg/ml), which are on the other hand undetectable by Albustix. In addition, it is possible to perform a semiquantitative test using various dilutions of urine samples with albumin concentration > 40 μg/ml, so to estimate approximately the UAlbE. The AT method is simple, fast and specific, and has proved to be useful for the identification of diabetic patients at risk for developing clinical nephropathy. Therefore, it may be used in screening programs for diabetic microproteinuria
Comparative experiments for tube agglutination test of pullorum antiserum with gamma ray Co/sup 60/ irradiated salmonella pullorum

Energy Technology Data Exchange (ETDEWEB)

Seo, B K [City Univ. of Seoul, Seoul (Republic of Korea)

1976-01-01

An agglutinability between naturally infected positive chicken serum of pullorum disease and hyperimmunized rabbit antiserum was compared. And the following results were obtained and summarized. On the agglutinability, Salmonella pullorum antigen which irradiated gamma-ray was better than another both formalized and heated antigen. Time of judgemented as positive titer in the tube agglutination test to the naturally infected positive chicken serum was it most suitable for 12 hours at 37/sup 0/C. Agglutination titer of positive immune chicken serum against gamma-ray irradiate Salmonella pullorum were as 320 approximately 640x.

THE INVESTIGATION OF BRUCELLA ANTIBODY WITH MILK RING TEST AND AGGLUTINATION TEST IN MILK COLLECTED FROM SAMSUN REGION

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Goknur TERZI

2006-06-01

Full Text Available In this study Brucella antibodies were investigated with agglutination test (Whey-AT and Milk Ring Test (MRT in a total of 100 milk samples as 50 of cow milk and 50 of goat milk collected from center and villages of Samsun. According to MRT Brucella antibodies was positive at 10 samples (20 % of cow milk and 6 samples (12 % of goat milk. In cow milk, 4 (8 % positive, 3 (6 % suspicious and 43 (86 % negative samples; in goat milk 3 (6 % positive, 2 (4 % suspicious and 45 (90 % negative samples were determined according to antibodies titre of serum agglutination test (Whey-AT. [TAF Prev Med Bull 2006; 5(3.000: 196-203
Rapid latex agglutination test for the serodiagnosis of human brucellosis

NARCIS (Netherlands)

Abdoel, Theresia H.; Smits, Henk L.

2007-01-01

We developed and evaluated a user-friendly latex agglutination assay for the serodiagnosis of human brucellosis. The assay was obtained by coating colored latex beads with Brucella lipopolysaccharides and drying of the activated beads onto white agglutination cards. Individual cards were sealed in a
Comparison of Rose Bengal Plate Agglutination, Standard tube agglutination and Indirect ELISA tests for detection of Brucella antibodies in Cows and Buffaloes

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S. N. Ghodasara

2010-04-01

Full Text Available A total of 180 serum samples (107 cows, 73 buffaloes from cases of abortion and various reproductive disorders were collected for detection of Brucella antibody by Rose Bengal Plate Agglutination Test (RBPT, Serum Tube Agglutination Test (STAT and indirect- ELISA (i-ELISA. The overall prevalence of brucellosis by RBPT, STAT and i-ELISA were 11.21%, 16.00% and 24.30% in cows 9.59%, 12.33% and 26.03% in buffaloes respectively. Overall seroprevalence of Brucellosis in cases of abortion, R.O.P. by RBPT, STAT and i-ELISA were 11.32%, 16.04% and 32.08% respectively. When three serological tests were compared, seropositivity was found highest by i-ELISA (25%, followed by STAT (14.45% and RBPT (10.56%. The results shows higher prevalence of brucellosis in cases of abortion and R.O.P., while at lower level from various reproductive disorders as detected serologically indicating endemicity of the infection in villages around Anand city, Gujarat. [Vet. World 2010; 3(2.000: 61-64
DNA & Protein detection based on microbead agglutination

KAUST Repository

Kodzius, Rimantas; Castro, David; Foulds, Ian G.; Parameswaran, Ash M.; Sumanpreet, K. Chhina

2012-01-01

the macroscopic observation. Agglutination-based tests are most often used to explore the antibody-antigen reactions. Agglutination has been used for mode protein assays using a biotin/streptavidin two-component system, as well as a hybridization based two
[Detection of anti-Leptospira antibodies in sera of patients in the latex agglutination test].

Science.gov (United States)

Volina, E G; Sarukhanova, L E; Iashina, N V; Prokopov, N I; Shkarlat, P E; Barysheva, I V

2001-01-01

The results of the preliminary evaluation of the sensitivity and specificity of the newly developed diagnostic test based on the determination of genus-specific antibodies to leptospires in the latex agglutination test, are presented. This test makes it possible to detect anti-Leptospira antibodies of any serogroup. The advantages of the developed test have been determined.
Good agreement of conventional and gel-based direct agglutination test in immune-mediated haemolytic anaemia

NARCIS (Netherlands)

Piek, C.J.; Teske, E.; van Leeuwen, M.W.; Day, M.J.

2012-01-01

Abstract Background The aim of this study was to compare a gel-based test with the traditional direct agglutination test (DAT) for the diagnosis of immune-mediated haemolytic anaemia (IMHA). Methods Canine (n = 247) and feline (n = 74) blood samples were submitted for DAT testing to two
Determination of immune status in dogs against CPV-2 by recombinant protein based latex agglutination test.

Science.gov (United States)

Thomas, Jobin; Singh, Mithilesh; Goswami, T K; Glora, Philma; Chakravarti, Soumendu; Chander, Vishal; Upmanyu, Vikramaditya; Verma, Suman; Sharma, Chhavi; Mahendran, K

2017-09-01

Canine parvoviral enteritis is a highly contagious viral illness caused by canine parvovirus-2 (CPV-2) which affects puppies of mainly 6-20 weeks of age. Vaccination is pivotal in preventing and controlling CPV-2 infection. Determination of antibody status is a critical determinant for successful vaccination. The hemagglutination inhibition (HI) test is 'gold standard' test for quantification of antibodies specific to CPV-2, although the execution of this test is not feasible under field conditions. The present study was undertaken to develop a point of care testing to determine immune status prior to CPV-2 vaccination or to detect seroconversion in immunized dogs by latex agglutination test (LAT) using recombinant antigen. Truncated portion of VP2 protein (tVP2) of CPV-2 was selected on the basis of antigenic indices, overexpressed the recombinant protein in E. coli system and was subsequently used in development of LAT. A total of 59 serum samples obtained from vaccinated (n = 54) and healthy unvaccinated (n = 5) dogs were tested. The positivity was observed in 85% (46/54) of these dogs with varying agglutination pattern. The overall sensitivity and specificity of latex agglutination test in comparison to HI test was recorded as 90% and 88% respectively with an agreement value of 90% (CI = 95%). Copyright © 2017 International Alliance for Biological Standardization. Published by Elsevier Ltd. All rights reserved.
Rapid detection of microalbuminuria in diabetic patients by an agglutination inhibition test. Comparison with radioimmunoassay

Energy Technology Data Exchange (ETDEWEB)

Giampietro, O; Miccoli, R; Di Palma, L; Bertolotto, A; Anichini, R; Navalesi, R; Clerico, A

1986-01-01

Subclinical elevation of urinary albumin excretion (UAlbE) early in the course of diabetes mellitus has been suggested to predict later clinical proteinuria and mortality. UAlbE is currently measured using radioimmunoassay (RIA) or radial immunodiffusion methods. However, these procedures are expensive and time-consuming and cannot be used as screening methods. Recently, an agglutination test (AT) has been suggested as a routinary method for the screening of microalbuminuria in diabetic patients. In this paper the results obtained are compared with an AT procedure and RIA method in a screening program of microproteinuria in diabetic patients. An immunological test (a latex agglutination assay) for the analysis of albuminura is used, which human albumin was adsorbed to latex beads (about 0.3 ..mu..l of a urine sample. Urine samples containing an albumin concentration >40 ..mu..g/ml were found to inhibit the agglutination of latex beads with antiserum. The RIA and AT results showed good agreement when urine samples were assayed soon after collection or after a short period of storage (less than or equal to3 weeks at -20 grade centigrades). The AT procedure has been adjusted in order to give a positive response (no agglutination) over the range of supranormal concentrations of urinary albumin (>40 ..mu..g/ml), which are on the other hand undetectable by Albustix. In addition, it is possible to perform a semiquantitative test using various dilutions of urine samples with albumin concentration > 40 ..mu..g/ml, so to estimate approximately the UAlbE. The AT method is simple, fast and specific, and has proved to be useful for the identification of diabetic patients at risk for developing clinical nephropathy. Therefore, it may be used in screening programs for diabetic microproteinuria. 21 refs.
Rapid detection of methicillin resistance in Staphylococcus aureus isolates by the MRSA-screen latex agglutination test

NARCIS (Netherlands)

W.B. van Leeuwen (Willem); C. van Pelt (Cindy); A. Luijendijk (Ad); H.A. Verbrugh (Henri); W.H.F. Goessens (Wil)

1999-01-01

textabstractThe slide agglutination test MRSA-Screen (Denka Seiken Co., Niigata, Japan) was compared with the mecA PCR ("gold standard") for the detection of methicillin resistance in Staphylococcus aureus. The MRSA-Screen test detected the penicillin-binding protein 2a
Diagnostic value of latex agglutination test in diagnosis of acute bacterial meningitis

Directory of Open Access Journals (Sweden)

Syeda Fasiha Mohammadi

2013-01-01

Full Text Available Objectives: To know the incidence of bacterial meningitis in children below five years of age. To compare conventional culture and antigen detection methods ( Latex agglutination test. Materials and Methods: 100 CSF samples of clinically suspected meningitis cases in children below 5 years of age were included. The samples were subjected to cell count, Gram stain, culture and LAT. The organisms isolated in the study were characterized according to standard procedures. Results: Of the 100 cases studied, 31 cases were diagnosed as ABM by Gram stain, culture and latex agglutination test as per WHO criteria. The hospital frequency of ABM was 1.7%. 15 (48.38 cases were culture positive. Gram stain was positive in 22(70.96 cases and LAT in 17(54.83 cases. Haemophilus influenzae was the most common causative agent of acute bacterial meningitis followed by S.pneumoniae. Case fatality rate was 45.16%.The sensitivity and specificity of LAT was 66.66% and 87.91% respectively. Conclusion : Bacterial meningitis is a medical emergency and early diagnosis and treatment is life saving and reduces chronic morbidity. LAT was more sensitive compared to conventional Gram stain and Culture technique in identifying the fastidious organisms like H.influenzae, S.pneumoniae and Group B Streptococcus. However, the combination of Gram stain, Culture and LAT proved to be more productive than any of the single tests alone.
Comparison of the indirect fluorescent antibody test and modified agglutination test for detection of anti-Toxoplasma gondii antibodies in rats / Comparação da reação de imunofluorescência indireta e do teste de aglutinação modificado na detecção de anticorpos anti-Toxoplasma gondii em ratos

Directory of Open Access Journals (Sweden)

Roberta Lemos Freire

2010-09-01

Full Text Available The toxoplasmosis is a zoonosis caused by Toxoplasma gondii and affects a lot of species of carnivores and omnivores, including the human. The rodents are important in the transmition cycle because they act as an infection font to felines, the definitive host of this protozoan. The objective of this work was to evaluate the Modified Agglutination Test (MAT for the serologic diagnosis of toxoplasmosis in rats, comparing with the Indirect Fluorescent Antibody Test (IFAT, which has been considered the golden standard in animal toxoplasmosis diagnosis. Kappa test was used for comparing the serologic tests (IFAT and MAT and for determination of cutoff appropriate to MAT in this animal species. 182 rats were caught on local recycling of solid waste and solid residue storage in Londrina city, Paraná. Out of the 182 rats, nine (4.94% were positive to IFAT at a dilution of 1:16, and 17 (9.34% and five (2.75% were reactive to MAT in dilutions 1:25 and 1:50, respectively. The comparison of results between the techniques presented kappa coefficients of 0.26 and 0.55, respectively at 1:25 and 1:50 dilutions of MAT. It can be concluded that the dilution 1:50 is the most suitable to be used as cutoff for detecting T. gondii antibodies in rats using MAT, because agreed with IFAT.A toxoplasmose é uma zoonose causada pelo Toxoplasma gondii que acomete várias espécies carnívoras e onívoras, incluindo o ser humano. Os roedores são importantes na cadeia epidemiológica da doença por servirem de fonte de infecção aos felídeos, os hospedeiros definitivos deste protozoário. O objetivo deste trabalho foi avaliar o Teste de Aglutinação Modificada (MAT na detecção de anticorpos contra T. gondii em ratos, comparando-o à Reação de Imunofluorescência Indireta (RIFI, considerada padrão ouro para o diagnóstico da toxoplasmose animal. Empregou-se o teste kappa para a comparação dos testes sorológicos (RIFI e MAT e para a determinação do ponto de corte
Sensitivity and specificity of various serologic tests for detection of Toxoplasma gondii infection in naturally infected sows

DEFF Research Database (Denmark)

Dubey, J.P.; Thulliez, P.; Weigel, R.M.

1995-01-01

antibodies by use of the modified agglutination test (MAT), latex agglutination test (LAT), indirect hemagglutination test (IHAT), and ELISA. Toxoplasma gondii was isolated from 170 hearts of 1,000 sows by bioassays in mice and cats. The percentage of samples diagnosed as positive for each of the serologic......, 29.4 and 98.3% for IHAT, 45.9 and 96.9% for LAT, and 72.9 and 85.9% for ELISA. The dye test was run at 1:20 dilution on only 893 sera because of bacterial contamination and presence of anticomplement substances. Dye test antibodies were found in 17.8% of the sera, and sensitivity and specificity were...
Leishmaniasis Direct Agglutination Test: Using Pictorials as Training Materials to Reduce Inter-Reader Variability and Improve Accuracy

NARCIS (Netherlands)

Adams, Emily R.; Jacquet, Diane; Schoone, Gerard; Gidwani, Kamlesh; Boelaert, Marleen; Cunningham, Jane

2012-01-01

Background: The Direct Agglutination Test (DAT) has a high diagnostic accuracy and remains, in some geographical areas, part of the diagnostic algorithm for Visceral Leishmaniasis (VL). However, subjective interpretation of results introduces potential for inter-reader variation. We report an
Latex agglutination using the periplasmic proteins antigen of Brucella melitensis is a successful, rapid, and specific serodiagnostic test for ovine brucellosis.

Science.gov (United States)

Ismael, Alaa Bassuny; Swelum, Ayman Abdel-Aziz; Mostafa, Salama A-H; Alhumiany, Abdel-Rahman A

2016-09-01

Brucellosis, especially caused by Brucella melitensis, is considered the most-widespread zoonosis in the world, particularly in developing countries. This study was planned to develop an accurate test for diagnosis of ovine brucellosis using a specific hot saline extracted soluble Brucella melitensis periplasmic proteins (SBPPs). The efficacy of the latex agglutination test (LAT) using SBPPs compared to the Rose Bengal test (RBT), buffered plate agglutination test (BPAT), serum agglutination test (SAT), and an indirect enzyme-linked immunosorbent assay (i-ELISA) was evaluated in the field diagnosis of ovine brucellosis. The test performance was evaluated by estimating sensitivity (Se), specificity (Sp), positive predictive value (PPV), negative predictive value (NPV), disease prevalence (DP), positive likelihood ratio (PLR), and negative likelihood ratio (NLR) using test agreement and bacteriological culture in 1777 samples. The false-positive result was significantly (P ⩽0.05) lower in LAT than RBT, BPAT, SAT, and i-ELISA. With reference to test agreement, the Se, Sp, PPV, and PLR were highest (P ⩽0.05) in LAT 99.33%, 99.88%, 98.68%, and 827.25%, respectively. With reference to bacteriological culture, the LAT and i-ELISA tests showed a significant difference in Se with SAT. However, no significant difference in specificity was detected. The DP was 8.44% in the five tests. In conclusion, LAT using SBPPs of B. melitensis could be a suitable serodiagnostic field test for ovine brucellosis, with high sensitivity and specificity. © The Author(s) 2016.
The direct agglutination test as an alternative method for the diagnosis of canine and human visceral leishmaniasis

NARCIS (Netherlands)

Terán-Angel, Guillermo; Schallig, Henk; Zerpa, Olga; Rodríguez, Vestalia; Ulrich, Marian; Cabrera, Maira

2007-01-01

Visceral leishmaniasis is the most severe clinical form of leishmaniasis and is often fatal without proper treatment. Therefore, early and accurate diagnosis is important, but often difficult in endemic areas. The aim was to evaluate a direct agglutination test as a potential visceral leishmaniasis
An influenza A virus agglutination test using antibody-like polymers.

Science.gov (United States)

Sukjee, Wannisa; Thitithanyanont, Arunee; Wiboon-Ut, Suwimon; Lieberzeit, Peter A; Paul Gleeson, M; Navakul, Krongkaew; Sangma, Chak

2017-10-01

Antibodies are commonly used in diagnostic routines to identify pathogens. The testing protocols are relatively simple, requiring a certain amount of a specific antibody to detect its corresponding pathogen. Antibody functionality can be mimicked by synthesizing molecularly imprinted polymers (MIPs), i.e. polymers that can selectively recognize a given template structure. Thus, MIPs are sometimes termed 'plastic antibody (PA)'. In this study, we have synthesized new granular MIPs using influenza A virus templates by precipitation polymerization. The selective binding of influenza A to the MIP particles was assessed and subsequently contrasted with other viruses. The affinities of influenza A virus towards the MIP was estimated based on an agglutination test by measuring the amount of influenza subtypes absorbed onto the MIPs. The MIPs produced using the H1N1 template showed specific reactivity to H1N1 while those produced using H5N1 and H3N2 templates showed cross-reactivity.
Sero-epidemiological assessment and diagnosis of visceral leishmaniasis in an endemic locality using Fast Agglutination Screening Test (FAST)

NARCIS (Netherlands)

Hailu, A.; Kroon, C. C. M.; Schoone, G. J.; Berhe, N.; Schallig, H. D. F. H.; Kager, P. A.

2002-01-01

The Fast Agglutination Screening Test (FAST) was employed on sera obtained from an endemic area of visceral leishmaniasis in southwestern Ethiopia, in February 2000. The study involved (i) active case detection among 1575 residents of two villages; and (ii) passive case detection in an outpatient
Antibody responses measured by various serologic tests in pigs orally inoculated with low numbers of Toxoplasma gondii oocysts

DEFF Research Database (Denmark)

Dubey, J. P.; Andrews, C.D.; Lind, Peter

1996-01-01

) infective oocysts, and 6 pigs served as uninoculated controls. Blood (serum) samples were obtained at 1- to 3-week intervals until euthanasia. At necropsy, the brain, heart, and tongue of pigs were bioassayed in mice and cats for isolation of T gondii. Modified agglutination test (MAT), using whole, fixed...
9 CFR 147.1 - The standard tube agglutination test. 1

Science.gov (United States)

2010-01-01

... may be done with a suitable pencil on etched portions of the tube, or by means of fast-gum labels. (3..., high agglutinability, but are not sensitive to negative and nonspecific sera. The stock cultures may be... for at least 20 hours at 37 °C. (h) The results shall be recorded as: N, or − (negative) when the...
ELISA Cut-off Point for the Diagnosis of Human Brucellosis; a Comparison with Serum Agglutination Test

Directory of Open Access Journals (Sweden)

Anahita Sanaei Dashti

2012-03-01

Full Text Available Background: Brucellosis is a world-wide disease, which has a diverse clinical manifestation, and its diagnosis has to be proven by laboratory data. Serum agglutination test (SAT is the most-widely used test for diagnosing brucellosis. The enzyme linked immunosorbent assay (ELISA can also determine specific antibody classes against brucella. It is a sensitive, simple and rapid test, which could be an acceptable alternative to SAT with fewer limitations, however, like any other new test it should be further evaluated and standardized for various populations. This study was planned to determine an optimal cut-off point, for ELISA which would offer maximum sensitivity and specificity for the test when compared to SAT.Methods: Four hundred and seven patients with fever and other compatible symptoms of brucellosis were enrolled in the study. Serum agglutination test, 2-Mercaptoethanol test, and ELISA were performed on their sera. Results: The cut-off point of 53 IU/ml of ELISA-IgG yielded the maximal sensitivity and specificity comparing to the other levels of ELISA-IgG, and was considered the best cut off-point of ELISA-IgG to diagnose acute brucellosis. At this cut-off, the sensitivity, specificity, positive predictive value, negative predictive value, positive likelihood ratio, and negative likelihood ratio were 84.09%, 85.38%, 62.20, 94.90, 5.75, 0.18, respectively.Conclusion: The best cut-off point of ELISA-IgG is 53 IU/ml, which yields the maximal sensitivity and specificity to diagnose acute brucellosis.

Making antigen of trypanosoma evansi and its examination by catt (card agglutination test) method

International Nuclear Information System (INIS)

Arifin, M; Irtisam; Estikoma Dyah; Yulia Ernawati; Boky, J.T

1998-01-01

An experiment was carried out for making antigen (Ag) of T. evansi by using experimental animals rats and guinea pigs for for developing parasites, and in cattle for making immune serum and normal serum. The parasites were irradiated by gamma rays ( 60 Co) at a dose of 300 Gy. The determination of antigen was done by using Card Agglutination Test (CATT) to the field samples serum of cattle. The results obtained showed that antigen was good enough potently and stable at minus 70 0 C storage during five months. (author)
[Diagnosis of human brucellosis. Role of pH in the seroagglutination test and influence of pH on the agglutinating activity of IgM, IgG and IgA antibodies].

Science.gov (United States)

Rubio Vallejo, Manuel; del Pozo, José L; Del Pozo León, José Luis; Hernández-Molina, Juan Manuel; Dorronsoro Ibero, Inés; Marrodán Ciordia, Teresa; Díaz García, Ramón

2002-04-01

To evaluate the role of pH in the seroagglutination test (SAT)and Rose Bengal (RB) test, and to determine the influence of pH on the agglutinating activity of IgM, IgG and IgA antibodies. The SAT was performed at pH 7.2 or pH 5.0 in standard microtiter-type polystyrene plates using Ring Test antigen or the Brucella suspension (BRUCAPT) provided in the Brucellacapt kits. Specific antibodies against native hapten were determined by radial immunodiffusion. Additionally, IgG, IgA and IgM fractions were separated from 8 sera by absorption chromatography and their agglutinating capacity was studied at pH 7.2 and 5.0. We studied 72 sera from patients with clinical brucellosis taken at the time of hospitalization, 16 from persons in contact with infected animals, and 16 from healthy donors. SAT results at pH 5.0 correlated with those obtained with the Rose Bengal test. Four Rose Bengal-positive sera were found to be SAT-negative at pH 7.2 and SAT-positive at pH 5.0. SAT performed at pH 5.0 with BRUCAPT antigen yielded higher titers than tests performed at pH 7.2 or 5.0 with Ring Test antigen (p IgA fractions were SAT-negative at pH 7.2 and SAT-positive at pH 5.0; the other 5 agglutinated at both pH conditions and were DTT-sensitive. All IgA fractions but one were positive by Rose Bengal. Agglutinating activity of the IgM fraction was not affected by pH. The SAT performed with the buffer and antigen suspension included in the Brucellacapt kit (pH 5.0) is highly useful for detecting agglutinating and non-agglutinating antibodies at pH 7.2.
High Fidelity, High Volume Agglutinate Manufacturing Process, Phase I

Data.gov (United States)

National Aeronautics and Space Administration — Up to 65% of the lunar soils are comprised of agglutinates. Although the importance of agglutinate in simulants is often debated, the fact is that agglutinates...
Comparison of Brucella immunoglobulin M and G flow assays with serum agglutination and 2-mercaptoethanol tests in the diagnosis of brucellosis

NARCIS (Netherlands)

Zeytinoğlu, Ayşin; Turhan, Ajda; Altuğlu, Imre; Bilgiç, Altinay; Abdoel, Theresia H.; Smits, Henk L.

2006-01-01

The diagnostic value of Brucella IgM/IgG flow assays was evaluated in comparison with serum agglutination and 2-mercaptoethanol tests by testing a selection of serum samples submitted to the laboratory because of clinical suspicion of brucellosis. All 39 admission and 11 follow-up samples that
Towards a high throughput droplet-based agglutination assay

KAUST Repository

Kodzius, Rimantas; Castro, David; Foulds, Ian G.

2013-01-01

This work demonstrates the detection method for a high throughput droplet based agglutination assay system. Using simple hydrodynamic forces to mix and aggregate functionalized microbeads we avoid the need to use magnetic assistance or mixing structures. The concentration of our target molecules was estimated by agglutination strength, obtained through optical image analysis. Agglutination in droplets was performed with flow rates of 150 µl/min and occurred in under a minute, with potential to perform high-throughput measurements. The lowest target concentration detected in droplet microfluidics was 0.17 nM, which is three orders of magnitude more sensitive than a conventional card based agglutination assay.
Towards a high throughput droplet-based agglutination assay

KAUST Repository

Kodzius, Rimantas

2013-10-22

This work demonstrates the detection method for a high throughput droplet based agglutination assay system. Using simple hydrodynamic forces to mix and aggregate functionalized microbeads we avoid the need to use magnetic assistance or mixing structures. The concentration of our target molecules was estimated by agglutination strength, obtained through optical image analysis. Agglutination in droplets was performed with flow rates of 150 µl/min and occurred in under a minute, with potential to perform high-throughput measurements. The lowest target concentration detected in droplet microfluidics was 0.17 nM, which is three orders of magnitude more sensitive than a conventional card based agglutination assay.
A study of the incubation of microbead agglutination assays in a microfluidic system

KAUST Repository

Castro, David

2016-12-19

This work reports on a quantitative study of the incubation of a microbead-based agglutination assay inside a microfluidic system. In this system, a droplet (1.25µL) consisting of a mixture of functionalized microbeads and analyte is flowed through a 0.51mm internal diameter silicone tube. Hydrodynamic forces alone produce a very efficient mixing of the beads within the droplet. We tested the agglutination at different speeds and show a robust response at the higher range of speeds (150 – 200µL/min), while also reaching a completion in the agglutination process. At these velocities, a length of 180cm is shown to be sufficient to confidently measure the agglutination assay, which takes between 2.5 – 3 minutes. This high throughput quantification method has the potential of accelerating the measurements of various types of biomarkers, which can greatly benefit the fields of biology and medicine.
Good agreement of conventional and gel-based direct agglutination test in immune-mediated haemolytic anaemia

Directory of Open Access Journals (Sweden)

Piek Christine J

2012-02-01

Full Text Available Abstract Background The aim of this study was to compare a gel-based test with the traditional direct agglutination test (DAT for the diagnosis of immune-mediated haemolytic anaemia (IMHA. Methods Canine (n = 247 and feline (n = 74 blood samples were submitted for DAT testing to two laboratories. A subset of canine samples was categorized as having idiopathic IMHA, secondary IMHA, or no IMHA. Results The kappa values for agreement between the tests were in one laboratory 0.86 for canine and 0.58 for feline samples, and in the other 0.48 for canine samples. The lower agreement in the second laboratory was caused by a high number of positive canine DATs for which the gel test was negative. This group included significantly more dogs with secondary IMHA. Conclusions The gel test might be used as a screening test for idiopathic IMHA and is less often positive in secondary IMHA than the DAT.
Red Blood Cell Agglutination for Blood Typing Within Passive Microfluidic Biochips.

Science.gov (United States)

Huet, Maxime; Cubizolles, Myriam; Buhot, Arnaud

2018-04-19

Pre-transfusion bedside compatibility test is mandatory to check that the donor and the recipient present compatible groups before any transfusion is performed. Although blood typing devices are present on the market, they still suffer from various drawbacks, like results that are based on naked-eye observation or difficulties in blood handling and process automation. In this study, we addressed the development of a red blood cells (RBC) agglutination assay for point-of-care blood typing. An injection molded microfluidic chip that is designed to enhance capillary flow contained anti-A or anti-B dried reagents inside its microchannel. The only blood handling step in the assay protocol consisted in the deposit of a blood drop at the tip of the biochip, and imaging was then achieved. The embedded reagents were able to trigger RBC agglutination in situ, allowing for us to monitor in real time the whole process. An image processing algorithm was developed on diluted bloods to compute real-time agglutination indicator and was further validated on undiluted blood. Through this proof of concept, we achieved efficient, automated, real time, and quantitative measurement of agglutination inside a passive biochip for blood typing which could be further generalized to blood biomarker detection and quantification.
Evaluation of latex agglutination test (KAtex) for early diagnosis of kala-azar.

Science.gov (United States)

Ahsan, M M; Islam, M N; Mollah, A H; Hoque, M A; Hossain, M A; Begum, Z; Islam, M T

2010-07-01

Kala-azar is one of the major public health problem in Bangladesh. But the diagnosis of the problem often is difficult, unusual and time consuming, a simple, noninvasive, easy to perform, reliable and rapid diagnostic test has been a long-felt need of the clinicians. Therefore, the present study was conducted to see the sensitivity and specificity of Latex Agglutination test (KAtex) to detect leishmanial antigen from urine of kala-azar cases. The study was carried out in the department of Paediatrics, Mymensingh Medical College and Hospital, Bangladesh during July to December, 2008. A total of 100 urine samples were collected of which 50 were confirmed kala-azar cases and 50 were age and sex matched controls. Out of 50 kala-azar cases 47 showed positive result of KAtex. The test was also positive in 01 out of 30 healthy controls. None of the febrile controls was positive by KAtex. The sensitivity, specificity, positive predictive value and negative predictive value of the test using presence of LD bodies in splenic and/or bone marrow aspirate as gold standard were 94%, 98%, 97.91% and 94.23% respectively. KAtex is simple, noninvasive, easy to perform, rapid and reliable test for diagnosing kala-azar in endemic area and useful for small, less equipped laboratories as well as for the laboratories with better facilities.
Two-Phase Microfluidic Systems for High Throughput Quantification of Agglutination Assays

KAUST Repository

Castro, David

2018-04-01

agglutination assay, and turn it into a quantitative High Sensitivity-CRP test, with a lower detection limit of 0.5 mg/L using light scattering. Agglutination assays are an incredibly versatile tool, capable of detecting an ever-growing catalog of infectious diseases, proteins and metabolites. A system such as that presented in this thesis is a step towards being able to produce high throughput microfluidic solutions with widespread adoption.
Rapid detection of methicillin resistance in coagulase-negative staphylococci by a penicillin-binding protein 2a-specific latex agglutination test.

Science.gov (United States)

Horstkotte, M A; Knobloch, J K; Rohde, H; Mack, D

2001-10-01

The detection of PBP 2a by the MRSA-Screen latex agglutination test with 201 clinical coagulase-negative staphylococci had an initial sensitivity of 98% and a high degree of specificity for Staphylococcus epidermidis strains compared to PCR for mecA. Determination of oxacillin MICs evaluated according to the new breakpoint (0.5 microg/ml) of the National Committee for Clinical Laboratory Standards exhibited an extremely low specificity for this population.
Surgical management of vulvovaginal agglutination due to lichen planus.

Science.gov (United States)

Fairchild, Pamela S; Haefner, Hope K

2016-02-01

Lichen planus is a rare dermatological disorder that is often associated with painful and disfiguring vulvovaginal effects. At the University of Michigan Center for Vulvar Diseases, we see many women with vulvovaginal lichen planus each year, with marked scarring and vulvovaginal agglutination that precludes vaginal intercourse and causes difficulty with urination. Through our experience, we developed a protocol for the operative management and postoperative care for severe vulvovaginal agglutination. Our objective is to share this protocol with a wider audience so that providers who see patients with these devastating effects of lichen planus can benefit from our experience to better serve this patient population. The figure represents a case of erosive lichen planus with early vaginal agglutination. The video reviews the pathophysiology and presentation of lichen planus. We then present a case of scarring and agglutination in a young woman, including our surgical management and postoperative care recommendations. Copyright © 2016 Elsevier Inc. All rights reserved.
Comparative determination of the rheumatic factor by means of agglutination, immunofluorescence and radioimmunoassay

Energy Technology Data Exchange (ETDEWEB)

Jaeger, L.; Storz, H.; Hein, G.; Schlenvoigt, G. (Friedrich-Schiller-Universitaet, Jena (German Democratic Republic). Bereich Medizin)

1982-01-01

The rheumatic factor (RF) was determined by means of agglutination, immunofluorescence (IF) test and radioimmunoassay (RIPEGA) in random groups of 56 patients with rheumatoid arthritis (RA), 13 patients with seronegative RA and 39 patients with psoriasis arthropathica. All three methods are of equal value with regard to the number of positive results. Further classification of seronegative patients, i.e. patients with a negative agglutination reaction and the clinical symptoms of RA is possible with the IF method and, above all, by means of RIPEGA. But because of the comprehensive test devices the two methods are only an alternative. Titer differences are attributed to the different indication principles and the immunological heterogeneity of RF. An improvement of the diagnosis of activity was not possible.
Comparative determination of the rheumatic factor by means of agglutination, immunofluorescence and radioimmunoassay

International Nuclear Information System (INIS)

Jaeger, L.; Storz, H.; Hein, G.; Schlenvoigt, G.

1982-01-01

The rheumatic factor (RF) was determined by means of agglutination, immunofluorescence (IF) test and radioimmunoassay (RIPEGA) in random groups of 56 patients with rheumatoid arthritis (RA), 13 patients with seronegative RA and 39 patients with psoriasis arthropathica. All three methods are of equal value with regard to the number of positive results. Further classification of seronegative patients, i.e. patients with a negative agglutination reaction and the clinical symptoms of RA is possible with the IF method and, above all, by means of RIPEGA. But because of the comprehensive test devices the two methods are only an alternative. Titer differences are attributed to the different indication principles and the immunological heterogeneity of RF. An improvement of the diagnosis of activity was not possible. (author)
HiRadMat: materials under scrutiny

CERN Multimedia

Anaïs Schaeffer

2011-01-01

CERN's new facility, HiRadMat (High Radiation to Materials), which is designed to test materials for the world's future particle accelerators, should be operational and welcoming its first experiments by the end of the year. The HiRadMat facility, located in the TNC tunnel. The materials used in the LHC and its experiments are exposed to very high-energy particles. The LHC machine experts obviously didn't wait for the first collisions in the world's most powerful accelerator to put the materials through their paces - the equipment was validated following a series of stringent tests. And these tests will get even tougher now, with the arrival of HiRadMat. The tunnel that formerly housed the West Area Neutrino Facility (WANF) has been completely revamped to make way for CERN's latest facility, HiRadMat. Supported by the Radioprotection service, a team from the Engineering (EN) Department handled the dismantling operations from October 2009 to December 2010. "We could only work on disman...
Applicability of the Monocyte Activation Test (MAT) in the quality control of the 17DD yellow fever vaccine.

Science.gov (United States)

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.
Rapid Detection of Methicillin Resistance in Coagulase-Negative Staphylococci by a Penicillin-Binding Protein 2a-Specific Latex Agglutination Test

OpenAIRE

Horstkotte, Matthias A.; Knobloch, Johannes K.-M.; Rohde, Holger; Mack, Dietrich

2001-01-01

The detection of PBP 2a by the MRSA-Screen latex agglutination test with 201 clinical coagulase-negative staphylococci had an initial sensitivity of 98% and a high degree of specificity for Staphylococcus epidermidis strains compared to PCR for mecA. Determination of oxacillin MICs evaluated according to the new breakpoint (0.5 μg/ml) of the National Committee for Clinical Laboratory Standards exhibited an extremely low specificity for this population.
The Classroom-Friendly ABO Blood Types Kit: Blood Agglutination Simulation

Science.gov (United States)

Arnold, Savittree Rochanasmita; Kruatong, Tussatrin; Dahsah, Chanyah; Suwanjinda, Duongdearn

2012-01-01

The classroom-friendly ABO blood type kit was developed by combining advantages of modelling and a simulation laboratory to teach the topics of ABO blood types and blood transfusion. Teachers can easily simulate the agglutination reaction on a blood type testing plate in the classroom, and show the students how this reaction occurs by using the…
Reactivity of various leishmanial antigens in a direct agglutination test and their value in differentiating post-kala azar dermal leishmaniasis from leprosy and other skin conditions

NARCIS (Netherlands)

El Harith, A.; Chowdhury, S.; Al-Masum, A.; Semião-Santos, S.; Das, P. K.; Akhter, S.; Vetter, J. C.; Haq, I.

1996-01-01

A direct agglutination test (DAT) for the detection of post-kala azar dermal leishmaniasis (PKDL) was evaluated in conditions that simulate the disease clinically or immunologically. A reference strain of Leishmania donovani (LEM 1399), and antigen preparations from Leishmania isolates from

A comparison of sperm agglutination and immobilization assays with a quantitative ELISA for anti-sperm antibody in serum.

Science.gov (United States)

Lynch, D M; Leali, B A; Howe, S E

1986-08-01

An enzyme-linked immunosorbent assay (ELISA) that quantitates antisperm antibody in serum was compared with standard sperm agglutination and immobilization assays with the use of sera from 40 normal and 292 subfertile individuals. Quantitation of the assay was accomplished by standardizing assay parameters, including the incorporation of a standard reference curve, the number of whole target sperm, the optimal dilution of serum, the selection of microtiter plate, and the time and temperatures involved in the adsorption and incubation phases. With this method, the level of antisperm antibody binding to target sperm in 40 normal fertile individuals was found to be 2.3 (+/- 1.1 standard deviation [SD]) fg immunoglobulin (Ig)/sperm. An increased mean level of 7.4 +/- 3.7 fg Ig/sperm was determined in 84 infertile patients with positive agglutination and/or immobilization tests. In 208 individuals with negative agglutination and immobilization tests the mean concentration of antisperm antibody was 2.5 +/- 1.3 fg Ig/sperm. Postvasectomy patients assayed by this method had a mean Ig binding value of 7.1 +/- 2.4 fg Ig/sperm. The infertile group with positive agglutination and/or immobilization tests had a significantly higher mean antisperm antibody level than the normal fertile group, according to the Student's t-test for independent samples (P less than 0.001). This indirect serum-based assay reproducibly quantitates antisperm antibody binding to whole target sperm, suggests the normal and abnormal levels of antisperm antibody, and correlates with standard functional assays.
The Dutch Brucella abortus monitoring programme for cattle: the impact of false-positive serological reactions and comparison of serological tests.

Science.gov (United States)

Emmerzaal, A; de Wit, J J; Dijkstra, Th; Bakker, D; van Zijderveld, F G

2002-02-01

The Dutch national Brucella abortus eradication programme for cattle started in 1959. Sporadic cases occurred yearly until 1995; the last infected herd was culled in 1996. In August 1999 the Netherlands was declared officially free of bovine brucellosis by the European Union. Before 1999, the programme to monitor the official Brucella-free status of bovine herds was primarily based on periodical testing of dairy herds with the milk ring test (MRT) and serological testing of all animals older than 1 year of age from non-dairy herds, using the micro-agglutination test (MAT) as screening test. In addition, serum samples of cattle that aborted were tested with the MAT. The high number of false positive reactions in both tests and the serum agglutination test (SAT) and complement fixation test (CFT) used for confirmation seemed to result in unnecessary blockade of herds, subsequent testing and slaughter of animals. For this reason, a validation study was performed in which three indirect enzyme-linked immunosorbent assays (ELISAs), the CFT and the SAT were compared using a panel of sera from brucellosis-free cattle, sera from experimentally infected cattle, and sera from cattle experimentally infected with bacteria which are known to induce cross-reactive antibodies (Pasteurella, Salmonella, Yersinia, and Escherichia). Moreover, four ELISAs and the MRT were compared using a panel of 1000 bulk milk samples from Brucella-free herds and 12 milk samples from Brucella abortus- infected cattle. It is concluded that the ELISA obtained from ID-Lelystad is the most suitable test to monitor the brucelosis free status of herds because it gives rise to fewer false-positive reactions than the SAT.
Development of kenaf mat for slope stabilization

Science.gov (United States)

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.
Structural analysis of closure cap barriers: A pre-test study for the Bentonite Mat Demonstration Project

International Nuclear Information System (INIS)

Gong, Chung; Pelfrey, J.R.

1993-01-01

The Bentonite Mat Demonstration Project (BMDP) is a field demonstration study to determine the construction/installation requirements, permeability, and subsidence performance characteristics of a composite barrier. The composite barrier will consist of on-site sandy-clay blanketed by a bentonite mat and a flexible High Density Polyethylene (HDPE) liner (also called flexible membrane liner). Construction of one control test pad and three bentonite test pads are planned. The control test pad will be used to establish baseline data. Underneath the composite clay cap is a four feet thick loose sand layer in which cavities will be created by evacuation of sand. The present work provides a mathematical model for the BMDP. The mathematical model will be used to simulate the mechanical and structural responses of the composite clay cap during the testing processes. Based upon engineering experience and technical references, a set of nominal soil parameters have been selected
Evolution of Shock Melt Compositions in Lunar Agglutinates

Science.gov (United States)

Vance, A. M.; Christoffersen, R.; Keller, L. P.

2015-01-01

Lunar agglutinates are aggregates of regolith grains fused together in a glassy matrix of shock melt produced during smaller-scale (mostly micrometeorite) impacts. Agglutinate formation is a key space weathering process under which the optically-active component of nanophase metallic Fe (npFe(sup 0)) is added to the lunar regolith. Here we have used energy-dispersive X-ray (EDX) compositional spectrum imaging in the SEM to quantify the chemical homogeneity of agglutinitic glass, correlate its homogeneity to its parent soil maturity, and identify the principle chemical components contributing to the shock melt compositional variations.
Determination of degree of RBC agglutination for blood typing using a small quantity of blood sample in a microfluidic system.

Science.gov (United States)

Chang, Yaw-Jen; Ho, Ching-Yuan; Zhou, Xin-Miao; Yen, Hsiu-Rong

2018-04-15

Blood typing assay is a critical test to ensure the serological compatibility of a donor and an intended recipient prior to a blood transfusion. This paper presents a microfluidic blood typing system using a small quantity of blood sample to determine the degree of agglutination of red blood cell (RBC). Two measuring methods were proposed: impedimetric measurement and electroanalytical measurement. The charge transfer resistance in the impedimetric measurement and the power parameter in the electroanalytical measurement were used for the analysis of agglutination level. From the experimental results, both measuring methods provide quantitative results, and the parameters are linearly and monotonically related to the degree of RBC agglutination. However, the electroanalytical measurement is more reliable than the impedimetric technique because the impedimetric measurement may suffer from many influencing factors, such as chip conditions. Five levels from non-agglutination (level 0) to strong agglutination (level 4+) can be discriminated in this study, conforming to the clinical requirement to prevent any risks in transfusion. Copyright © 2017 Elsevier B.V. All rights reserved.
Seroepidemiological detection of antibodies against Leptospira spp using microscopic agglutination test in Urmia cows and sheep

Directory of Open Access Journals (Sweden)

Ramin Ag

2013-01-01

Full Text Available The study was designed to determine the level of incidence, titer and various serovars of leptospira in 203 cows and 166 sheep at Urmia abattoir in 2011. Blood samples were collected during the slaughter of animals and sera were separated to evaluate the serological reaction to Leptospira spp by Microscopic Agglutination Test (MAT using live antigens representing Leptospira interrogans serogroups: pomona, grippotyphosa, canicola, hardjo, icterrohaemoragiae, and ballum. Overall, 36% of cows and 19.3% of sheep including 33.8% of bulls, 40.5% of female cows, 18.3% of rams and 25% of ewes had a positive reaction to at least one of the leptospira serovars. The most prevalent serovars in cows were pomona (22.7%, grippotyphosa (13.8%, and hardjo (8.4%, and in sheep were grippotyphosa (66.7%, pomona (26.2% and canicola (7.1%. Other serovars were not detected in cows and sheep. The most prevalent serological titers of 1:100 and 1:200 in cows was 18.2% and 26.6%, and for sheep were 13.5% and 8%, respectively, and of 1:400 in sheep was 2.3%. Cows with a positive reaction to one, two and three serovars were 28.6%, 5.9%, and 1.5% and sheep positive to one and two serovars were 13.3% and 6%, respectively. Age comparison in seropositive cows and sheep showed a significantly increased infection (p<0.05 from young to adult ruminants, while no differences were seen regarding gender. The main mixed serovars were between grippotyphosa/pomona, grippotyphosa/canicola and canicola/pomona. The gender comparison of the serovars' distribution revealed that the pomona and grippotyphosa were predominant among other leptospiral serovars in cows and sheep, respectively. In conclusion, the rate of leptospirosis in Urmia cows was about 2 fold in sheep. The most current serovars in cows and sheep were pomona and grippotyphosa, respectively. The majority of animals was infected with one serovar, but polyserovars, are also possible. The highest titer (1:200 was observed in cows
Imaging based agglutination measurement of magnetic micro-particles on a lab-on-a-disk platform

DEFF Research Database (Denmark)

Wantiya, P.; Burger, Robert; Alstrøm, Tommy Sonne

2014-01-01

In this work we present a magnetic micro beads based agglutination assay on a centrifugal microfluidic platform. An imaging based method is used to quantify bead agglutination and measure the concentration of antibodies or C-reactive protein in solution.......In this work we present a magnetic micro beads based agglutination assay on a centrifugal microfluidic platform. An imaging based method is used to quantify bead agglutination and measure the concentration of antibodies or C-reactive protein in solution....
Evaluation of an Immunocapture-Agglutination Test (Brucellacapt) for Serodiagnosis of Human Brucellosis

Science.gov (United States)

Orduña, Antonio; Almaraz, Ana; Prado, Ana; Gutierrez, M. Purificación; Garcia-Pascual, Agustina; Dueñas, Ana; Cuervo, Milagros; Abad, Ramon; Hernández, Beatriz; Lorenzo, Belen; Bratos, Miguel A.; Torres, Antonio Rodriguez

2000-01-01

We evaluated the validity and the usefulness of a new test for the diagnosis of human brucellosis based on an immunocapture-agglutination technique. A total of 315 sera from 82 patients with a diagnosis of brucellosis, 157 sera from patients in whom brucellosis was suspected but not confirmed, and 412 sera from people living in rural areas with endemic brucellosis were studied. The seroagglutination test (SAT), Coombs anti-Brucella test, and Brucellacapt test were evaluated. All the initial sera from the 82 patients proved to be positive in Brucellacapt and Coombs tests, while only 75 (91.4%) were positive in the SAT. If a ≥1/160 diagnostic threshold titer was defined for the Brucellacapt test, Coombs test, and SAT, the sensitivities were 95.1, 91.5, and 65.8%, respectively. Taking the same diagnostic threshold titer for the 157 sera from the unconfirmed but suspected patients, the specificities of the Brucellacapt, Coombs, and SAT were 81.5, 96.2, and 100%, respectively; for the 412 control sera, the specificities were 99.0, 99.8, and 100%. The diagnostic efficiency (area below the receiver operating characteristic curve) of Brucellacapt was 0.987852 (95% confidence interval [CI], 0.95109 to 0.99286), very similar to the diagnostic efficiency of the Coombs test (0.97611; 95% CI, 0.94781 to 0.99146) and higher than that of SAT (0.91013; 95% CI, 0.86649 to 0.94317). The results of the Brucellacapt test were compared with those of the Coombs test (correlation coefficient, 0.956; P = 0.000) and SAT (correlation coefficient, 0.866; P = 0.000). The study shows very good correlation between the Brucellacapt and Coombs tests, with a high concordance between titers obtained in the two tests. Nevertheless, lower correlation and concordance were found between the Brucellacapt and Coombs tests when the results for titers of ≥1/160 were compared (0.692; P = 0.000). In acute brucellosis, the Brucellacapt and Coombs tests render positive titers of ≥1/160. When the titers
R and G color component competition of RGB image decomposition as a criterion to register RBC agglutinates for blood group typing.

Science.gov (United States)

Doubrovski, Valeri A; Ganilova, Yuliya A; Zabenkov, Igor V

2014-03-01

A new approach of the criterion assignment for registration of erythrocyte agglutinates to instrumentally determine blood group type is suggested. The criterion is based on comparison of R and G components of RGB decomposition of microscopy digital image taken for the blood-serum mixture sample. For the chosen experimental conditions, the minimal size (area) of RBC agglutinate to be registered by the criterion suggested is estimated theoretically. The proposed method was tested experimentally on the example of monitoring agglutinates in flow. The encouraging experimental results were obtained for improvement of the resolving power of the method; the optimal experimental conditions were revealed for maximum resolution. Though the suggested method was realized for dynamic (flow) blood group determination, it could also be applied for diagnostics in a stationary environment. This approach increases the reliability of RBC agglutinates registration and, hence, blood group typing. The results may be used to develop the apparatus for automated determination of human blood group.
Effects of preprocessing method on TVOC emission of car mat

Science.gov (United States)

Wang, Min; Jia, Li

2013-02-01

The effects of the mat preprocessing method on total volatile organic compounds (TVOC) emission of car mat are studied in this paper. An appropriate TVOC emission period for car mat is suggested. The emission factors for total volatile organic compounds from three kinds of new car mats are discussed. The car mats are preprocessed by washing, baking and ventilation. When car mats are preprocessed by washing, the TVOC emission for all samples tested are lower than that preprocessed in other methods. The TVOC emission is in stable situation for a minimum of 4 days. The TVOC emitted from some samples may exceed 2500μg/kg. But the TVOC emitted from washed Polyamide (PA) and wool mat is less than 2500μg/kg. The emission factors of total volatile organic compounds (TVOC) are experimentally investigated in the case of different preprocessing methods. The air temperature in environment chamber and the water temperature for washing are important factors influencing on emission of car mats.
BrucellaCapt versus classical tests in the serological diagnosis and management of human brucellosis.

Science.gov (United States)

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.
Aplicabilidade do Teste de Ativação de Monócitos (MAT no Brasil: importância da sua utilização como teste para detecção de pirogênios no controle da qualidade de produtos injetáveis | Applicability of the Monocyte Activation Test (MAT in Brazil: the importance of its use as a test for the detection of pyrogens in the quality control of injectable products

Directory of Open Access Journals (Sweden)

Cristiane Caldeira da Silva

2015-08-01

Full Text Available O MAT (sigla do inglês Monocyte Activation Test é considerado um potencial substituto do Teste de Pirogênios, entretanto: i. não foi avaliado para um número suficiente de produtos; ii. faltam dados que possam garantir sua capacidade em detectar pirogênios não endotoxinas; e iii. deve ser realizada a validação do método para cada classe de produtos. O objetivo foi identificar as monografias que requerem testes de pirogenicidade e propor os produtos que têm por base somente o teste de pirogênios como um ponto de partida para futuros estudos. As monografias específicas nas Farmacopeias Americana, Europeia e Brasileira que recomendam o Teste de Pirogênios ou Teste de Endotoxina Bacteriana ou LAL (sigla do inglês Limulus Amebocyte Lysate foram: Teste de Pirogênios: 20 monografias na Americana, 37 na Europeia e 28 na Brasileira. LAL: 619 monografias na Americana, 157 na Europeia e 41 na Brasileira. Somente quatro produtos requerem testes de pirogenicidade nas três farmacopeias analisadas. O Teste de Pirogênios e LAL são recomendados em seis monografias na Brasileira e 15 na Europeia. Na Brasileira, a maior parte dessas monografias é referente a produtos biológicos, sugerindo, assim, que estes devam ser os primeiros a ser testados, uma vez que são ensaiados em animais. ----------------------------------------------------------------------------------------------- Monocyte Activation Test (MAT is thought to be a good replacement for rabbit pyrogen test (RPT; however, MAT remains controversial. MAT was not adequately evaluated in a sufficient number of products, and there is no sufficient data that support the ability of MAT to detect non-endotoxin pyrogens. Furthermore, MAT was used subject to validation for each specific product. The aim of this study was to identify in main pharmacopoeias, whose monographs require pyrogenicity tests, and propose those products for which only the rabbit pyrogen test is required to be used as a
Talking Mats

DEFF Research Database (Denmark)

2012-01-01

Talking Mats are visualizations in the handy size of a set of cards used to support interviews with people with mental disabilities.......Talking Mats are visualizations in the handy size of a set of cards used to support interviews with people with mental disabilities....
Are the Major Agglutinative Languages Genetically Related?

Science.gov (United States)

Hakola, H. P. A.

1989-01-01

Examination of accidental CVC and CV correspondences among languages representing 5 large families of agglutinative languages found that comparison pairs had much more similarity between basic 100-word vocabularies than would have been possible by mere chance, supporting the hypothesis that those 5 language families were mutually related.…
Isolation, in vitro culture, ultrastructure study, and characterization by lectin-agglutination tests of Phytomonas isolated from tomatoes (Lycopersicon esculentum) and cherimoyas (Anona cherimolia) in southeastern Spain.

Science.gov (United States)

Sanchez-Moreno, M; Fernandez-Becerra, C; Mascaro, C; Rosales, M J; Dollet, M; Osuna, A

1995-01-01

Plants of Lycopersicon esculentum (grown in greenhouses) and Anona cherimolia cultivated in southeastern Spain were examined for the presence of trypanosomatid flagellates. Kinetoplastid protozoa were found in the fruits but not in the phloem or other plant tissues. Parasites were detected from the onset of fruiting. Isolates were detected from the onset of fruiting. Isolates were adapted to in vitro culturing in monophase media. The form and the structural organization was studied by scanning and transmission electron microscopy. The parasites showed an ultrastructural pattern similar to that of other species of the genus Phytomonas. In tomatoes experimentally inoculated with flagellates cultivated in vitro, we observed that the parasites did not lose their infectious capacity. Three strains of trypanosomatids of the genus Phytomonas, isolated from different species of Euphorbia (E. characias and E. hyssopifolia) and from Cocos nucifera, were compared with our isolates by lectin-agglutination tests. Our isolates were different from the two strains isolated from Euphorbia, but with this technique we could not differentiate our isolates from those of the coconut, nor could we differentiate between the isolates, their ultrastructural similarity together with their similar behavior in the lectin-agglutination test suggesting that these isolates have a common origin.
PREVALENCE OF ANTIBODIES AGAINST TOXOPLASMA GONDII IN POLAR BEARS (URSUS MARITIMUS) FROM SVALBARD AND EAST GREENLAND

Science.gov (United States)

Serum samples from 419 polar bears (Ursus maritimus) from Svalbard and the Barents Sea (collected 1990 - 2000) and 108 polar bears from East Greenland (collected 1999 - 2004) were assayed for antibodies against Toxoplasma gondii using the modified agglutination test (MAT). Antibody prevalences were ...
Protein and Bacterial Antifouling Behavior of Melt-Coextruded Nanofiber Mats.

Science.gov (United States)

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.
Physical and Mechanical Properties of Jute Mat Reinforced Epoxy Composites

Directory of Open Access Journals (Sweden)

S.M Sadaf

2011-11-01

Full Text Available Cellulose jute fibre offers a number of benefits as reinforcement for synthetic polymers since it has a high specific strength and stiffness, low hardness, relatively low density and biodegradability. To reduce moisture uptake and hence to improve the mechanical properties of the composites, bleached jute mats were incorporated as reinforcing elements in the epoxy matrix. Composites at varying volume fractions and different orientations of jute mat were fabricated by hot compression machine under specific pressures and temperatures. Tensile, flexure, impact and water absorption tests of composites were conducted. Jute mat oriented at (0 ± 45–90° composites showed reduced strength compared to (0–90° fibre mat composites. Impact strength and water uptake of high volume fraction jute mat reinforced composites was higher compared to that of lower volume fraction composites. Fracture surfaces of jute mat composites were analyzed under SEM. Fracture surface of (0–90° jute mat oriented composites showed twisted fibres, while (0 ± 45–90° jute mat oriented composites had fibre pull-out without any twisting. Overall, composites containing 52% jute mat at orientations of (0–90° showed better properties compared to other fabricated composites.
Effects of tacky mat contamination on bond degradation for Chemlok/liner and NBR/liner bonds

Science.gov (United States)

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.

Document Categorization with Modified Statistical Language Models for Agglutinative Languages

Directory of Open Access Journals (Sweden)

Tantug

2010-11-01

Full Text Available In this paper, we investigate the document categorization task with statistical language models. Our study mainly focuses on categorization of documents in agglutinative languages. Due to the productive morphology of agglutinative languages, the number of word forms encountered in naturally occurring text is very large. From the language modeling perspective, a large vocabulary results in serious data sparseness problems. In order to cope with this drawback, previous studies in various application areas suggest modified language models based on different morphological units. It is reported that performance improvements can be achieved with these modified language models. In our document categorization experiments, we use standard word form based language models as well as other modified language models based on root words, root words and part-of-speech information, truncated word forms and character sequences. Additionally, to find an optimum parameter set, multiple tests are carried out with different language model orders and smoothing methods. Similar to previous studies on other tasks, our experimental results on categorization of Turkish documents reveal that applying linguistic preprocessing steps for language modeling provides improvements over standard language models to some extent. However, it is also observed that similar level of performance improvements can also be acquired by simpler character level or truncated word form models which are language independent.
MatLab Script and Functional Programming

Science.gov (United States)

Shaykhian, Gholam Ali

2007-01-01

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

Science.gov (United States)

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.
Biomedical Applications of Antibacterial Nanofiber Mats Made of Electrospinning with Wire Electrodes

Directory of Open Access Journals (Sweden)

Yi-Jun Pan

2016-02-01

Full Text Available Twisted stainless steel wires are used as wire electrodes for electrospinning the polyvinyl alcohol (PVA/zinc citrate nanofiber mats. The morphology and diameter of the nanofibers in PVA/zinc citrate nanofiber mats are evaluated. We measured the antibacterial efficacy against Staphylococcus aureus (S. aureus and Escherichia coli (E. coli of the nanofiber mats. We also examined the cell adhesion affinity of mammalian tissue culture cells on these nanofiber mats. Our results indicate that an increase in zinc citrate increases the viscosity and electrical conductivity of PVA solution. In addition, increasing zinc citrate results in a smaller diameter of nanofibers that reaches below 100 nm. According to the antibacterial test results, increasing zinc citrate enlarges the inhibition zone of S. aureus but only has a bacteriostatic effect against E. coli. Finally, cell adhesion test results indicate that all nanofiber mats have satisfactory cell attachment regardless of the content of zinc citrate.
MAT-DB - A database for nuclear energy related materials data

International Nuclear Information System (INIS)

Over, H.H.

2009-01-01

The web-enabled materials database (Mat-DB) of JRC-IE has a long-term history in storing materials test data resulting from European and international research projects. The database structure and the user-guidance has bee permanently updated improved and optimized. The database is implemented in the secure ODIN portal: https://odin.jrc.ec.europa.eu of JRC-IE. This architecture guarantees fast access to confidential and public data and documentation which are stored in an inter-related document management database (DoMa). It is a part of JRC's nuclear knowledge management. Mat-DB hosts the whole pool of IAEA surveillance data of reactor pressure vessel materials from different nuclear power plants of the member states. Mat-DB contains also thousands of European GEN IV reactor systems related R and D materials data which are an important basis for the evaluating and extrapolating design data for candidate materials and setting up design rules covering high temperature exposure, irradiation and corrosion. Those data and rules would match also fusion related components. Mat-DB covers thermo-mechanical and thermo-physical properties data of engineering alloys at low, elevated and high temperatures for base materials and joints, including irradiated materials for nuclear fission and fusion applications, thermal barrier coated materials for gas turbines and properties of corroded materials. The corrosion part refers to weight gain/loss data of high temperature exposed engineering alloys and ceramic materials. For each test type the database structure reflects international test standards and recommendations. Mat-DB features an extensive library of evaluation programs for web-enabled assessment of uniaxial creep, fatigue, crack growth and high temperature corrosion properties. Evaluations can be performed after data retrieval or independently of Mat-DB by transferring other materials data in a given format to the programs. The fast evaluation processes help the user to
Radiation-induced alterations in binding of concanavalin A to cells and in their susceptibility to agglutination

International Nuclear Information System (INIS)

Takahashi, Kazuhide; Kaneko, Ichiro

1986-01-01

Cell susceptibility to agglutination mediated by a plant lectin, concanavalin A (Con A), and the binding capacity of Con A to cells following γ-irradiation have been examined in mouse myeloid leukaemia cells cultured in suspension. Irradiation caused an immediate decrease in the amount of Con A bound to the cell surface, whereas susceptibility of irradiated cells to agglutination by Con A was unchanged when compared to that of the unirradiated cells. Post-irradiation incubation of cells at 37 0 resulted in a temporary, more than 1.3-fold increase in cell susceptibility to agglutination 60 min after irradiation, whereas binding capacity of cells for Con A gradually-recovered following irradiation, reaching a comparable level to that of unirradiated cells 3 h after irradiation. Cell susceptibility to agglutination by Con A does not depend strongly on its binding capacity. (author)
Fabrication and In Vitro/In Vivo Performance of Mucoadhesive Electrospun Nanofiber Mats Containing α-Mangostin.

Science.gov (United States)

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.
Prospective evaluation of three rapid diagnostic tests for diagnosis of human leptospirosis.

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Marga G A Goris

Full Text Available BACKGROUND: Diagnosis of leptospirosis by the microscopic agglutination test (MAT or by culture is confined to specialized laboratories. Although ELISA techniques are more common, they still require laboratory facilities. Rapid Diagnostic Tests (RDTs can be used for easy point-of-care diagnosis. This study aims to evaluate the diagnostic performance of the RDTs LeptoTek Dri Dot, LeptoTek Lateral Flow, and Leptocheck-WB, prospectively. METHODOLOGY: During 2001 to 2012, one or two of the RDTs at the same time have been applied prior to routine diagnostics (MAT, ELISA and culture on serum specimens from participants sent in for leptospirosis diagnosis. The case definition was based on MAT, ELISA and culture results. Participants not fulfilling the case definition were considered not to have leptospirosis. The diagnostic accuracy was determined based on the 1(st submitted sample and paired samples, either in an overall analysis or stratified according to days post onset of illness. RESULTS: The overall sensitivity and specificity for the LeptoTek Dri Dot was 75% respectively 96%, for the LeptoTek Lateral Flow 78% respectively 95%, and for the Leptocheck-WB 78% respectively 98%. Based on the 1(st submitted sample the sensitivity was low (51% for LeptoTek Dri Dot, 69% for LeptoTek Lateral Flow, and 55% for Leptocheck-WB, but substantially increased when the results of paired samples were combined, although accompanied by a lower specificity (82% respectively 91% for LeptoTek Dri Dot, 86% respectively 84% for LeptoTek Lateral Flow, and 80% respectively 93% for Leptocheck-WB. CONCLUSIONS: All three tests present antibody tests contributing to the diagnosis of leptospirosis, thus supporting clinical suspicion and contributing to awareness. Since the overall sensitivity of the tested RDTs did not exceed 80%, one should be cautious to rely only on an RDT result, and confirmation by reference tests is strongly recommended.
Comparison of a New and Rapid Method: Brucella Coombs Gel Test With Other Diagnostic Tests.

Science.gov (United States)

Kalem, Fatma; Ergün, Ayşe Gül; Durmaz, Süleyman; Doğan, Metin; Ertuğrul, Ömür; Gündem, Seval

2016-09-01

The aim of this study was to detect reliability of Brucella Coombs gel test (BCGT) by comparing with with ELISA (IgG + IgM), Standard agglutination test, and Brucella immunocapture agglutination methods in serological diagnosis of brucellosis. Brucella Coombs gel test (BCGT), Brucella ELISA (IgG + IgM), Standard agglutination test, and Brucella immunocapture agglutination tests of 78 patients with presumptive diagnosis of brucellosis which were sent to Microbiology Laboratory of Konya Numune Hospital from various regions of Konya were studied. Of 78 patients with ELISA IgG and IgM, STA, BICA and BCGT; 26, 21, 10, 12 and 12 were positive. When compared with BICA, the sensitivity and specifity of BCGT were 100% and 100%, respectively. According to results BCGT can be used as a diagnostic test in routine laboratories after more comprehensive studies in control groups and patients. © 2016 Wiley Periodicals, Inc.
A deep-sea agglutinated foraminifer tube constructed with planktonic foraminifer shells of a single species

Science.gov (United States)

Pearson, Paul N.; Expedition 363 Shipboard Scientific Party, IODP

2018-01-01

Agglutinated foraminifera are marine protists that show apparently complex behaviour in constructing their shells, involving selecting suitable sedimentary grains from their environment, manipulating them in three dimensions, and cementing them precisely into position. Here we illustrate a striking and previously undescribed example of complex organisation in fragments of a tube-like foraminifer (questionably assigned to Rhabdammina) from 1466 m water depth on the northwest Australian margin. The tube is constructed from well-cemented siliciclastic grains which form a matrix into which hundreds of planktonic foraminifer shells are regularly spaced in apparently helical bands. These shells are of a single species, Turborotalita clarkei, which has been selected to the exclusion of all other bioclasts. The majority of shells are set horizontally in the matrix with the umbilical side upward. This mode of construction, as is the case with other agglutinated tests, seems to require either an extraordinarily selective trial-and-error process at the site of cementation or an active sensory and decision-making system within the cell.
Estimation of axial stiffness of plant fibres from compaction of non-woven mats

DEFF Research Database (Denmark)

Gamstedt, E. K.; Bommier, E.; Madsen, Bo

2014-01-01

-plane randomly oriented fibre mats. The model by Toll is used to relate the load-displacement curve from the test to the Young modulus of the fibre, taking into account the natural variability in fibre cross section. Several tests have been performed on hemp fibre mats and compared with results from single...
Toxoplasmosis in Caribbean islands: Seroprevalence in pregnant women in ten countries, and isolation and report of new genetic types of Toxoplasma gondii from dogs from St. Kitts, West Indies

Science.gov (United States)

Little is known of clinical toxoplasmosis in humans and animals in the Caribbean countries. We investigated the prevalence of IgG and IgMantibodies in 437 pregnant women from 10 English speaking Caribbean countries. Antibodies (IgG) to T. gondii (modified agglutination test, MAT, cut-off 1:6) were f...
Testing the utility of matK and ITS DNA regions for discrimination of Allium species

Science.gov (United States)

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 ...
Modeling the pullout characteristics of welded wire mats embedded in silty sand

International Nuclear Information System (INIS)

Sampaco, C.L.; Anderson, L.R.; Nielson, M.R.

1994-01-01

This paper is an outgrowth of the on-going research on discrete finite element modeling of welded wire mesh reinforced soil structures such as the welded wire and RSE walls. The stiffness characteristics of the wire mesh-soil interfaces are modeled by a nonlinear hyperbolic relationship between the applied pullout stress and the associated mat placement. The relevant parameters are estimated from laboratory pullout tests that were conducted for welded wire mats embedded on silty sand. Since the bulk of the pullout resistance of welded wire mesh reinforcements is derived from the bearing resistance of the transverse wires that constitute the test mats. This feature permits proper evaluation of actual interface parameters for the actual reinforced soil structures in which the actual lengths of the mats are longer (i.e. more transverse members) than the specimen used in the laboratory pullout tests. The resulting pullout stress-displacement formulations are then verified by comparing the predicted pullout resistance to the existing specifications and design methods for estimated the pullout capacities of grid reinforcements. 22 refs., 13 figs
Negative serosurvey of Toxoplasma gondii antibodies in Golden-headed Lion Tamarin (Leontopithecus chrysomelas from Niterói/RJ, Brazil

Directory of Open Access Journals (Sweden)

Camila Vieira Molina

Full Text Available Abstract New World Nonhuman Primates are highly susceptible to clinical toxoplasmosis. Serum samples from 126 recently captured Leontopithecus chrysomelas, from an exotic and invasive population, were tested for Toxoplasma gondii antibodies by the modified agglutination test (MAT, cut-off 1:25; all were seronegative. The MAT is highly specific and is not species-specific. This is the first report of T. gondii survey in this tamarin in the wild. This result is consistent with prior reports that showed the high susceptibility of the species to infection by T. gondii usually with high mortality rates.
A simple system for in-droplet incubation and quantification of agglutination assays

KAUST Repository

Castro, David

2013-10-28

This work reports on a simple system for quantitative sensing of a target analyte based on agglutination in micro-channels. Functionalized microbeads and analyte with no prior incubation are flowed in droplets (~2μL) through a thin silicone tube filled with mineral oil at a flow rate of 150 μL/min. Hydrodynamic forces alone produce a highly efficient mixing of the beads within the droplet, without the need of complex mixing structures or magnetic actuation. The setup allows rapid observation of agglutination (<2 min), which is quantified using image analysis, and has potential application to high-throughput analysis.
A simple system for in-droplet incubation and quantification of agglutination assays

KAUST Repository

Castro, David; Kodzius, Rimantas; Foulds, Ian G.

2013-01-01

This work reports on a simple system for quantitative sensing of a target analyte based on agglutination in micro-channels. Functionalized microbeads and analyte with no prior incubation are flowed in droplets (~2μL) through a thin silicone tube filled with mineral oil at a flow rate of 150 μL/min. Hydrodynamic forces alone produce a highly efficient mixing of the beads within the droplet, without the need of complex mixing structures or magnetic actuation. The setup allows rapid observation of agglutination (<2 min), which is quantified using image analysis, and has potential application to high-throughput analysis.
Synthesis for Lunar Simulants: Glass, Agglutinate, Plagioclase, Breccia

Science.gov (United States)

Weinstein, Michael; Wilson, Stephen A.; Rickman, Douglas L.; Stoeser, Douglas

2012-01-01

The video describes a process for making glass for lunar regolith simulants that was developed from a patented glass-producing technology. Glass composition can be matched to simulant design and specification. Production of glass, pseudo agglutinates, plagioclase, and breccias is demonstrated. The system is capable of producing hundreds of kilograms of high quality glass and simulants per day.
Speeding up pyrogenicity testing: Identification of suitable cell components and readout parameters for an accelerated monocyte activation test (MAT).

Science.gov (United States)

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.
Estimation of axial stiffness of plant fibres from compaction of non-woven mats

International Nuclear Information System (INIS)

Gamstedt, E K; Bommier, E; Madsen, B

2014-01-01

Plant fibres are known to show a large variability in stiffness, which makes it time-consuming to experimentally characterize this property by conventional tensile testing. In this work, an alternative method is used, where the average fibre stiffness is back-calculated from compaction tests of in-plane randomly oriented fibre mats. The model by Toll is used to relate the load–displacement curve from the test to the Young modulus of the fibre, taking into account the natural variability in fibre cross section. Several tests have been performed on hemp fibre mats and compared with results from single-fibre tensile testing. The average back-calculated Young's modulus of the fibres was 45 GPa, whereas the average value from tensile testing ranged from 30 to 60 GPa. The straightforward compaction test can be useful in ranking of fibre stiffness, provided that the mat is composed of well-separated fibres and not of twisted yarns. (paper)

Cross neutralizing antibodies in hamsters vaccinated with leptospiral bacterins produced with three serovars of serogroup Sejroe

Directory of Open Access Journals (Sweden)

Rosana Tabata

2002-09-01

Full Text Available Three leptospiral bacterins, produced with different serovars of Serogroup Sejroe, namely the hardjo (bacterin A, wolffi (bacterin B and guaricura (bacterin C, were evaluated in male hamsters (Mesocricetus auratus by comparing the agglutinating and neutralizing antibodies titers using microscopic agglutination (MAT and in vitro growth inhibition (GIT tests. The immunization schedule was based on two 1.0 mL doses of non-diluted formalininactivated whole culture bacterin given through subcutaneous route with 10-day interval. The challenge was performed ten days after the second vaccine dose, when the animals were inoculated with 0.2 mL of non-inactivated cultures of each serovar through intraperitoneal route. On the 21st post-challenge day (PCD, all animals were bled and their sera were joined in pools (n=8 and tested by MAT and GIT. All vaccinated and control animals presented no clinical signs of leptospirosis after the challenge, but the serovar guaricura was isolated from the kidneys of control animals on the 21st PCD. The MAT results showed cross agglutinins between serovars hardjo and wolffi, and between wolffi and guaricura. The GIT results revealed the presence of cross neutralizing antibodies between serovars wolffi or guaricura against hardjo, wolffi and guaricura. It was found that the tested strain of serovar hardjo did not produce detectable levels of neutralizing antibodies, indicating its poor immunogenicity.
Bioactive extracts of red seaweeds Pterocladiella capillacea and Osmundaria obtusiloba (Floridophyceae: Rhodophyta) with antioxidant and bacterial agglutination potential.

Science.gov (United States)

de Alencar, Daniel Barroso; de Carvalho, Fátima Cristiane Teles; Rebouças, Rosa Helena; Dos Santos, Daniel Rodrigues; Dos Santos Pires-Cavalcante, Kelma Maria; de Lima, Rebeca Larangeira; Baracho, Bárbara Mendes; Bezerra, Rayssa Mendes; Viana, Francisco Arnaldo; Dos Fernandes Vieira, Regine Helena Silva; Sampaio, Alexandre Holanda; de Sousa, Oscarina Viana; Saker-Sampaio, Silvana

2016-04-01

To evaluate the antioxidant, antibacterial and bacterial cell agglutination activities of the hexane (Hex) and 70% ethanol (70% EtOH) extracts of two species of red seaweeds Pterocladiella capillacea (P. capillacea) and Osmundaria obtusiloba. In vitro antioxidant activity was determined by DPPH radical scavenging assay, ferric-reducing antioxidant power assay, ferrous ion chelating assay, β-carotene bleaching assay and total phenolic content quantification. Antimicrobial activity was tested using the method of disc diffusion on Mueller-Hinton medium. The ability of algal extracts to agglutinate bacterial cells was also tested. The 70% EtOH extract of the two algae showed the highest values of total phenolic content compared to the Hex extract. The results of DPPH for both extracts (Hex, 70% EtOH) of Osmundaria obtusiloba (43.46% and 99.47%) were higher than those of P. capillacea (33.04% and 40.81%) at a concentration of 1000 μg/mL. As for the ferrous ion chelating, there was an opposite behavior, extracts of P. capillacea had a higher activity. The extracts showed a low ferric-reducing antioxidant power, with optical density ranging from 0.054 to 0.180. Antioxidant activities of all extracts evaluated for β-carotene bleaching were above 40%. There was no antibacterial activity against bacterial strains tested. However, the extracts of both species were able to agglutinate bacterial Gram positive cells of Staphylococcus aureus and Gram negative cells of Escherichia coli, multidrug-resistant Salmonella and Vibrio harveyi. This is the first report of the interaction between these algal extracts, rich in natural compounds with antioxidant potential, and Gram positive and Gram negative bacterial cells. Copyright © 2016 Hainan Medical College. Production and hosting by Elsevier B.V. All rights reserved.
Thermomechanical analyses of phenolic foam reinforced with glass fiber mat

International Nuclear Information System (INIS)

Zhou, Jintang; Yao, Zhengjun; Chen, Yongxin; Wei, Dongbo; Wu, Yibing

2013-01-01

Highlights: • Over 10% glass fiber was used to reinforce phenolic foam in the shape of glass fiber mat. • Nucleating agents were used together with glass fiber mat and improved tensile strength of phenolic foam by 215.6%. • Nucleating agents lead to a smaller bubble size of phenolic foam. • The glass transition temperature of phenolic foam remained unchanged during the reinforcement. - Abstract: In this paper, thermomechanical analysis (TMA) and dynamic mechanical analysis were employed to study the properties of phenolic foam reinforced with glass fiber mat. Unreinforced phenolic foam was taken as the control sample. Mechanical tests and scanning electron microscopy were performed to confirm the results of TMA. The results show that glass fiber mat reinforcement improves the mechanical performance of phenolic foam, and nucleating agents improve it further. Phenolic foam reinforced with glass fiber mat has a smaller thermal expansion coefficient compared with unreinforced foam. The storage modulus of the reinforced phenolic foam is also higher than that in unreinforced foam, whereas the loss modulus of the former is lower than that of the latter. The glass transition temperature of the phenolic foam matrix remains unchanged during the reinforcement
Evaluation of Penicillin Binding Protein 2a Latex Agglutination Assay for Identification of Methicillin-Resistant Staphylococcus aureus Directly from Blood Cultures

OpenAIRE

Chapin, Kimberle C.; Musgnug, Michael C.

2004-01-01

The penicillin binding protein 2a (PBP2a) latex agglutination test using a blood culture pellet was compared to the oxacillin screen agar method using isolated colonies. For blood cultures positive for Staphylococcus aureus (n = 70), the direct PBP2a test was 18% sensitive and 100% specific. The PBP2a test shows poor sensitivity when used directly with positive blood cultures.
Seroprevalence of Mycoplasma gallisepticum antibody by ELISA and serum plate agglutination test of laying chicken

Directory of Open Access Journals (Sweden)

Md. Zulfekar Ali

2015-01-01

Full Text Available Aim: Mycoplasma gallisepticum (MG is important avian pathogen responsible for chronic respiratory disease of chicken and turkeys, which result in large economic loss for the poultry industry. The objectives of this study were determination of seroprevalence of MG antibody of commercial layer chicken at laying period in selected areas of Bangladesh. Materials and Methods: A total of 563 blood samples were collected randomly from selected commercial layer chickens at laying period during the period from July to December, 2013. Indirect enzyme linked immunosorbent assay (iELISA and serum plate agglutination (SPA test were performed to detect the presence of antibodies against MG. Results: Of 563 samples, 64.47% and 56.13% showed an overall prevalence of MG antibodies in iELISA and SPA test respectively. Prevalence of MG was recorded the highest (69.63% at 50-55 weeks of age compared with lowest (53.26% at 56-61 weeks of age (p<0.05. Significant (p<0.05 effect of breed were observed in the seroprevalence of MG infection in layer birds in the present study. The overall, 68.77%, 63.74% and 59.37% prevalence were found respectively in sonali, ISA Brown and White leg horn. The prevalence of MG antibodies was the highest (70.13% in December followed by November (68%, October (65.67%, August (63.46%, September (58.54% and July (51.78% month. The seroprevalence of MG antibodies was higher (69.63% in most of the large flocks and lower (56.82% in small flocks. Conclusion: Therefore, might be suggested that the commercial layer farms should be routinely checked to monitor MG infection and the reactor birds should be culled since MG organism has the potential to transmit vertically. The correlation between MG antibody in month and flock size was not significant (p=0.359 and p=0.868, respectively.
Matérn thinned Cox processes

DEFF Research Database (Denmark)

Andersen, Ina Trolle; Hahn, Ute

2016-01-01

and hard core behaviour can be achieved by applying a dependent Matérn thinning to a Cox process. An exact formula for the intensity of a Matérn thinned shot noise Cox process is derived from the Palm distribution. For the more general class of Matérn thinned Cox processes, formulae for the intensity...
Matérn thinned Cox processes

DEFF Research Database (Denmark)

Andersen, Ina Trolle; Hahn, Ute

of clustering and hard core behaviour can be achieved by applying a dependent Matérn thinning to a Cox process. An exact formula for the intensity of a Matérn thinned shot noise Cox process is derived from the Palm distribution. For the more general class of Matérn thinned Cox processes, formulae...
Ectomycorrhizal mats alter forest soil biogeochemistry

Science.gov (United States)

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...
Two-Phase Microfluidic Systems for High Throughput Quantification of Agglutination Assays

KAUST Repository

Castro, David

2018-01-01

assay, with a minimum detection limit of 50 ng/mL using optical image analysis. We compare optical image analysis and light scattering as quantification methods, and demonstrate the first light scattering quantification of agglutination assays in a two
Application of PCR-based DNA sequencing technique for the detection of Leptospira in peripheral blood of septicemia patients

OpenAIRE

Ram, S.; Vimalin, J.M.; Jambulingam, M.; Tiru, V.; Gopalakrishnan, R.K.; Madhavan, H.N.

2012-01-01

Aim: Isolation, dark field detection and microscopic agglutination test (MAT) are considered ―gold standard‖ tests for diagnosis of Leptospirosis. Several PCR assays are reported but very few have been evaluated for detection of Leptospirosis. Therefore, this study was undertaken. This study aims to design and standardize polymerase chain reaction (PCR) - based DNA sequencing technique for the detection of pathogenic Leptospira from peripheral blood of patients clinically diagnosed with septi...
Leptospira Serovars for Diagnosis of Leptospirosis in Humans and Animals in Africa: Common Leptospira Isolates and Reservoir Hosts.

Science.gov (United States)

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.
Molecular ecology of microbial mats

NARCIS (Netherlands)

Bolhuis, H.; Cretoiu, M.S.; Stal, L.J.

2014-01-01

Phototrophic microbial mats are ideal model systems for ecological and evolutionary analysis of highly diverse microbial communities. Microbial mats are small-scale, nearly closed, and self-sustaining benthic ecosystems that comprise the major element cycles, trophic levels, and food webs. The steep
Agglutinating and bactericidal properties of fractions of rabbit anti-Vibrio cholerae serum.

Science.gov (United States)

Pike, R M; Chandler, C H

1969-06-01

The major portion of the agglutinating and bactericidal activity of the sera of rabbits immunized with live Vibrio cholerae or with cholera vaccine was found in the gammaM fractions during the early stages of immunization. After 5 weeks or more, gammaG fractions accounted for more than half of the agglutinating activity. When late antibody was measured as the amount of protein precipitated by somatic antigens, nearly 3 times as much gammaG as gammaM was required for agglutination, and about 30 times as much gammaG as gammaM was required to kill 50% of a standard inoculum in the presence of complement. The ratio of vibriocidal to agglutinin titer of gammaG fractions at different stages of immunization was more variable than that of gammaM fractions. More complement was required for a vibriocidal effect by gammaG than by gammaM. Increasing the amount of complement decreased the amount of both gammaG and gammaM required to kill, but smaller amounts of gammaM required disproportionately larger amounts of complement. Less time was required by gammaM than by gammaG to kill 50% of the inoculum. Removal of the group-reactive antibody from anti-Ogawa serum and serum fractions by absorption with Inaba reduced the vibriocidal titer by more than one-half.
Diagnosis of Trichomonous vaginalis by microscopy, latex agglutination, diamond's media, and PCR in symptomatic women, Khartoum, Sudan.

Science.gov (United States)

Saleh, Amir M; Abdalla, Hamid S; Satti, Abdelsalam B; Babiker, Suad M; Gasim, Gasim I; Adam, Ishag

2014-03-06

Trichomoniasis is the most common sexually transmitted disease. However, limited data are available on an effective technique for the diagnosis of Trichomonas vaginalis. A cross-sectional study was conducted to evaluate the accuracy of wet mount microscopy, latex agglutination, Diamond's media, and polymerase chain reaction (PCR) for detection of T. vaginalis among symptomatic women who attended the gynecological clinic at Khartoum, Sudan. Of the 297 women studied, 252 (84.8%) were positive for T. vaginalis by wet mount microscopy, 257 (86.5%) by latex agglutination, 253 (85.2%) by Diamond's media, and 253 (85.2%) by PCR. The sensitivity and specificity of wet mount microscopy were 99.2% and 97.7%, respectively, compared with PCR. The sensitivity and specificity of latex agglutination and Diamond's media were 99.6% and 88.6%, and 100.0% and 86.4%, respectively, compared with PCR. In this study, wet mount microscopy, latex agglutination, and Diamond's media were found to be highly sensitive and specific. However, the availability and cost effectiveness might limit the use of Diamond's media and PCR in routine practice. The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/7859723851211496.
Validity Study of a Jump Mat Compared to the Reference Standard Force Plate.

Science.gov (United States)

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).
Growth, composition and metal removal potential of a Phormidium bigranulatum-dominated mat at elevated levels of cadmium

Energy Technology Data Exchange (ETDEWEB)

Kumar, Dhananjay [Plant Molecular Biology and Plant Physiology Lab, Lab no. 114, School of Life Sciences, Jawaharlal Nehru University, New Delhi 110 067 (India); Yadav, Arpana [Laboratory of Algal Biology, Department of Botany, Banaras Hindu University, Varanasi 221 005 (India); Gaur, J.P., E-mail: gaurjp@yahoo.co.in [Laboratory of Algal Biology, Department of Botany, Banaras Hindu University, Varanasi 221 005 (India)

2012-07-15

Prompted by the fact that interaction of metals with cyanobacterial mats has been little studied, the present study evaluates the response of a cyanobacterial mat, dominated by Phormidium bigranulatum, to elevated concentrations of Cd{sup 2+} in the medium. The mat failed to grow at 7 {mu}M of Cd{sup 2+} when the metal as also the mat inoculum were simultaneously added to the medium right in the beginning of the experiment due to marked sensitivity of P. bigranulatum, the main constituent of the mat, to high concentrations of Cd{sup 2+}. However, the mat previously grown in Cd{sup 2+}-free medium for a time period of 1-4 weeks grew successfully when exposed to media containing very high concentrations of Cd{sup 2+}. Four-week-old mat could grow at 250 {mu}M of Cd{sup 2+}, which has been found toxic to many cyanobacteria and algae by previous researchers. Greater tolerance of older mats to Cd{sup 2+} may be due to greater proportion of exopolysaccharides, which are well known to sequester metal ions extracellularly, in them. Whereas the relative proportion of P. bigranulatum declined at high concentrations of the test metal that of green algae increased due most likely to their tolerance to Cd{sup 2+}. Air bubbles were seen entrapped in the mat due obviously to photosynthetic activity. Elevated concentrations of Cd{sup 2+} reduced the number of air bubbles in the mat. Decline in number of air bubbles at high concentrations of metal ions was more prominent in the case of younger mat than in the older one. The present study also evaluated changes in species composition of mats of different age that were subsequently grown in Cd{sup 2+} enriched culture medium. Younger mats showed change in species composition at very low concentrations of Cd{sup 2+}, but older mats showed little changes even at very high concentrations of the test metal. Hence older mats more strongly resisted to changes in its species composition than the younger ones upon exposure to high
Structural Changes in Stx1 Engineering Monoclonal Antibody Improves Its Functionality as Diagnostic Tool for a Rapid Latex Agglutination Test

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Daniela Luz

2018-02-01

Full Text Available Stx1 toxin is one of the AB5 toxins of Shiga toxin-producing Escherichia coli (STEC responsible for foodborne intoxication during outbreaks. The single-chain variable fragment (scFv is the most common recombinant antibody format; it consists of both variable chains connected by a peptide linker with conserved specificity and affinity for antigen. The drawbacks of scFv production in bacteria are the heterologous expression, conformation and stability of the molecule, which could change the affinity for the antigen. In this work, we obtained a stable and functional scFv-Stx1 in bacteria, starting from IgG produced by hybridoma cells. After structural modifications, i.e., change in protein orientation, vector and linker, its solubility for expression in bacteria was increased as well as the affinity for its antigen, demonstrated by a scFv dissociation constant (KD of 2.26 × 10−7 M. Also, it was able to recognize purified Stx1 and cross-reacted with Stx2 toxin by ELISA (Enzyme-Linked Immunosorbent Assay, and detected 88% of Stx1-producing strains using a rapid latex agglutination test. Thus, the scFv fragment obtained in the present work is a bacteria-produced tool for use in a rapid diagnosis test, providing an alternative for STEC diagnosis.
Out-of-plane ultimate shear strength of RC mat-slab foundations

International Nuclear Information System (INIS)

Kumagai, Hitoshi; Nukui, Yasushi; Imamura, Akira; Terayama, Takeshi; Hagiwara, Tetsuya; Kojima, Isao

2011-01-01

There have been few studies on the out-of-plane shear in RC mat-slab foundations, and the reasonable method has been demanded to estimate ultimate shear strength of RC mat-slab foundations in the nuclear facilities. In the previous study, the out-of-plane loading tests on the 20 square slab specimens had been performed to collect the fundamental data. In this study, the test results were successfully predicted by 3D non-linear Finite Element Analysis. It has been confirmed that the ultimate shear stress in the slab specimen can be estimated by the Arakawa's formula, which is commonly used to estimate the shear strength of RC beams. (author)
A latex agglutination test for the field determination of abnormal vitellogenin production in male fishes contaminated by estrogen mimics

International Nuclear Information System (INIS)

Magalhaes, Ilizabete; Pihan, Jean-Claude; Falla, Jairo

2004-01-01

Estrogen mimics are pollutants present in the aquatic environment. These compounds induce abnormalities in the reproductive system of male fishes, which lead to a total or partial male feminization, or to their demasculinization. Ultimately, these alterations could lead to a disappearance of the total contaminated fish population. Moreover, these toxic substances possess the capacity to mimic endogenous estrogens and to induce the abnormal production of vitellogenin (VTG) in male and immature fishes. The purpose of this research was to develop an easy, specific, cheap and fast method for diagnosing the contamination of male fishes by estrogen mimics, using VTG as biomarker. The selected method is based on a reverse latex agglutination test (rLAT), developed with monoclonal antibodies specific of this biomarker. The development of this VTG-rLAT has involved, firstly, the purification of carp VTG to produce monoclonal antibodies, specifics of this protein. One of these antibodies was selected to recover latex particles (diameter: 1 μm). Finally, the immunoreactivity of the VTG-rLAT was verified with different fish plasma samples from males treated with 17β-estradiol and non-treated males or females in vitellogenesis
Smart monitoring of fluid intake and bladder voiding using pressure sensitive mats.

Science.gov (United States)

Cohen-McFarlane, Madison; Green, James R; Knoefel, Frank; Goubran, Rafik

2016-08-01

Pressure sensitive mats have been used in noninvasive smart monitoring for a variety of problems including breathing rate monitoring, sleep monitoring, mobility, and weight. This paper describes a proof of concept application of pressure mats to monitor fluid intake/output (fluid cycle) events during the night. The ability to more accurately track such events has potential implications for monitoring those individuals who have nocturia, a condition where a person wakes at night to urinate. Data were collected from a healthy young female subject instructed to drink as much water as was comfortable (700mL) and lie in a supine position on a mattress located directly on three pressure mats. This was compared to an initial data set collected immediately after voiding but before drinking, 30 minutes after drinking, 60 minutes after drinking and a final data set after again voiding the bladder. The additional pressure from the 700mL of water was detectible and tracked over the course of the hour-long testing session under idealized conditions. This provides a proof-of-concept that nocturnal fluid intake and bladder voiding events can be tracked using non-invasive pressure-sensitive mats, however additional testing and development is required to achieve a deployable monitoring system.

Mononucleosis spot test

Science.gov (United States)

Monospot test; Heterophile antibody test; Heterophile agglutination test; Paul-Bunnell test; Forssman antibody test ... The mononucleosis spot test is done when symptoms of mononucleosis are ... Fatigue Fever Large spleen (possibly) Sore throat Tender ...
Leishmaniasis direct agglutination test: using pictorials as training materials to reduce inter-reader variability and improve accuracy.

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Emily R Adams

Full Text Available BACKGROUND: The Direct Agglutination Test (DAT has a high diagnostic accuracy and remains, in some geographical areas, part of the diagnostic algorithm for Visceral Leishmaniasis (VL. However, subjective interpretation of results introduces potential for inter-reader variation. We report an assessment of inter-laboratory agreement and propose a pictorial-based approach to standardize reading of the DAT. METHODOLOGY: In preparation for a comparative evaluation of immunochromatographic diagnostics for VL, a proficiency panel of 15 well-characterized sera, DAT-antigen from a single batch and common protocol was sent to nine laboratories in Latin-America, East-Africa and Asia. Agreement (i.e., equal titre or within 1 titer with the reading by the reference laboratory was computed. Due to significant inter-laboratory disagreement on-site refresher training was provided to all technicians performing DAT. Photos of training plates were made, and end-titres agreed upon by experienced users of DAT within the Visceral-Leishmaniasis Laboratory-Network (VL-LN. RESULTS: Pre-training, concordance in DAT results with reference laboratories was only 50%, although agreement on negative sera was high (94%. After refresher training concordance increased to 84%; agreement on negative controls increased to 98%. Variance in readings significantly decreased after training from 3.3 titres to an average of 1.0 titre (two-sample Wilcoxon rank-sum (Mann-Whitney test (z = -3,624 and p = 0.0003. CONCLUSION: The most probable explanation for disagreement was subjective endpoint reading. Using pictorials as training materials may be a useful tool to reduce disparity in results and promote more standardized reading of DAT, without compromising diagnostic sensitivity.
An Insight into the proteome of Crithidia fasciculata choanomastigotes as a comparative approach to axenic growth, peanut lectin agglutination and differentiation of Leishmania spp. promastigotes.

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Pedro J Alcolea

Full Text Available The life cycle of the trypanosomatid Crithidia fasciculata is monogenetic, as the unique hosts of these parasites are different species of culicids. The comparison of these non-pathogenic microorganisms evolutionary close to other species of trypanosomatids that develop digenetic life cycles and cause chronic severe sickness to millions of people worldwide is of outstanding interest. A ground-breaking analysis of differential protein abundance in Crithidia fasciculata is reported herein. The comparison of the outcome with previous gene expression profiling studies developed in the related human pathogens of the genus Leishmania has revealed substantial differences between the motile stages of these closely related organisms in abundance of proteins involved in catabolism, redox homeostasis, intracellular signalling, and gene expression regulation. As L. major and L. infantum agglutinate with peanut lectin and non-agglutinating parasites are more infective, the agglutination properties were evaluated in C. fasciculata. The result is that choanomastigotes are able to agglutinate with peanut lectin and a non-agglutinating subpopulation can be also isolated. As a difference with L. infantum, the non-agglutinating subpopulation over-expresses the whole machinery for maintenance of redox homeostasis and the translation factors eIF5a, EF1α and EF2, what suggests a relationship between the lack of agglutination and a differentiation process.
Siwonhan-mat: The third taste of Korean foods

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Soon Ah Kang

2016-03-01

Conclusion: Siwonhan-mat is a unique sensation found in Korean food. Understanding siwonhan-mat is a key to learning about Korean food and its food culture. Therefore, this paper serves an important role in understanding Korean food. Siwonhan-mat is often mistranslated using words to describe temperature, such as cool. This misinterpretation has resulted in confusion over the original meaning of siwonhan-mat and contributed to the incorrect usage of the word.
Does siwonhan-mat represent delicious in Korean foods?

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Dai Ja Jang

2016-06-01

Conclusion: Balancing kan is a determining factor of siwonhan-mat in Korean cuisine. Particularly, a strong association between siwonhan-mat and deliciousness was found in kuk and tang, suggesting the importance of siwonhan-mat in experiencing the best flavor in Korean food.
Widal agglutination titre: a rapid serological diagnosis of typhoid fever in developing countries

International Nuclear Information System (INIS)

Aftab, R.; Khurshid, R.

2009-01-01

To study the reliability of a single Widal test and to find out the diagnostic significance of 'O' and 'H' agglutinin titre in the diagnosis of typhoid fever. Community-based case-control study conducted from Jan 2001 to June 2007. The blood samples were collected from the medical and out door department of Sir Ganga Ram Hospitals, Lahore. The diagnostic value of an acute phase single Widal agglutination test for suspected typhoid fever was evaluated in 733 consecutive patients with fever lasting 6 or more days. In 733 patients with fever 84 (11.45%) were positive for Widal test. A noteworthy rise 1/320 of H and/or O agglutinin titre was observed in 86 (11.3%) of patients with typhoid fever. In the absence of vaccination an elevated level of H and/or O agglutinin titre of 1: 320 is of diagnostic value for typhoid fever especially in our setting where a single sample of serum is relied on for the diagnosis of typhoid fever. (author)
Widal agglutination titre: a rapid serological diagnosis of typhoid fever in developing countries

Energy Technology Data Exchange (ETDEWEB)

Aftab, R [Fatima Jinnah Medical College Lahore, Lahore (Pakistan). Dept. of Pathology; Khurshid, R [Fatima Jinnah Medical College Lahore, Lahore (Pakistan). Dept. of Biochemistry

2009-01-15

To study the reliability of a single Widal test and to find out the diagnostic significance of 'O' and 'H' agglutinin titre in the diagnosis of typhoid fever. Community-based case-control study conducted from Jan 2001 to June 2007. The blood samples were collected from the medical and out door department of Sir Ganga Ram Hospitals, Lahore. The diagnostic value of an acute phase single Widal agglutination test for suspected typhoid fever was evaluated in 733 consecutive patients with fever lasting 6 or more days. In 733 patients with fever 84 (11.45%) were positive for Widal test. A noteworthy rise 1/320 of H and/or O agglutinin titre was observed in 86 (11.3%) of patients with typhoid fever. In the absence of vaccination an elevated level of H and/or O agglutinin titre of 1: 320 is of diagnostic value for typhoid fever especially in our setting where a single sample of serum is relied on for the diagnosis of typhoid fever. (author)
Phenotypic variation and characterization of mutant matting in shiitake

International Nuclear Information System (INIS)

Ibrahim Mahmood; Azhar Mohamad

2016-01-01

Shiitake (Lentinula edodes) is an edible mushroom that has many uses such as: pharmaceutical, nutraceutical and cosmeceutical industries. In this study, we will induce Shiitake to create the genetic variation via exposing the spores of shiitake to gamma (γ) ray at different doses (0-700 Gy) then make the matting between two different monokaryon mycelium (MM). potato dextrose agar (PDA), this media will be used for spore germination and monokaryon mycelium subculturing during this study. The compatibility of the matting will be observed macroscopically (observing on the plates of PDA) and microscopically (by observing the clamps test under the microscope (Olympus brand)). The finding of this study, there is no significant changing in the growth performance of irradiated monokaryon mycelium in comparing with non-irradiated mycelium. From 108 matting only 15 were compatibles. This study, the physical mutagen will be used followed by mating as a normal stage of life cycle for creating potential strain of shiitake with alteration in phenotypic characterization of dikaryon mycelium (DM) as a compatible mating for two MM. (author)
Regulation of electron transfer processes affects phototrophic mat structure and activity

Science.gov (United States)

Ha, Phuc T.; Renslow, Ryan S.; Atci, Erhan; Reardon, Patrick N.; Lindemann, Stephen R.; Fredrickson, James K.; Call, Douglas R.; Beyenal, Haluk

2015-01-01

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 mVAg/AgCl [cathodic (CAT) mat system] and +300 mVAg/AgCl [anodic (AN) 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. These data suggested that variation in the
Regulation of electron transfer processes affects phototrophic mat structure and activity

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Haluk eBeyenal

2015-09-01

Full Text Available 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 mVAg/AgCl (cathodic mat system and +300 mVAg/AgCl (anodic 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 anodic and cathodic mat systems. Interestingly, the cathodic mats generated the highest reducing current at the same time points that the anodic mats showed the highest oxidizing current. To characterize the physicochemical factors influencing electron transfer processes, we measured depth profiles of dissolved oxygen 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 cathodic mats than in the anodic mats. We also used NMR spectroscopy for high-resolution quantitative metabolite analysis and found that the cathodic 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. These data suggested that
Regulation of electron transfer processes affects phototrophic mat structure and activity.

Science.gov (United States)

Ha, Phuc T; Renslow, Ryan S; Atci, Erhan; Reardon, Patrick N; Lindemann, Stephen R; Fredrickson, James K; Call, Douglas R; Beyenal, Haluk

2015-01-01

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 mVAg/AgCl [cathodic (CAT) mat system] and +300 mVAg/AgCl [anodic (AN) 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. These data suggested that variation in the
Disruption of photoautotrophic intertidal mats by filamentous fungi

DEFF Research Database (Denmark)

Carreira, Cátia; Staal, Marc Jaap; Falkoski, Daniel

2015-01-01

Summary: Ring-like structures, 2.0-4.8cm in diameter, observed in photosynthetic microbial mats on the Wadden Sea island Schiermonnikoog (the Netherlands) showed to be the result of the fungus Emericellopsis sp. degrading the photoautotrophic top layer of the mat. The mats were predominantly comp...
Direct detection of methicillin resistance in Staphylococcus aureus in blood culture broth by use of a penicillin binding protein 2a latex agglutination test.

Science.gov (United States)

Qian, Qinfang; Venkataraman, Lata; Kirby, James E; Gold, Howard S; Yamazumi, Toshiaki

2010-04-01

We studied the utility of performing a penicillin binding protein 2a latex agglutination (PBP-LA) assay directly on Bactec blood culture broth samples containing Staphylococcus aureus to rapidly detect methicillin resistance. The sensitivity, specificity, positive predictive value, and negative predictive value of this method were 94.1%, 97.5%, 98%, and 92.9%, respectively.
Contributions of Ectomycorrhizal Fungal Mats to Forest Soil Carbon Cycles

Science.gov (United States)

Kluber, L. A.; Phillips, C. L.; Myrold, D. D.; Bond, B. J.

2008-12-01

Ectomycorrhizal (EM) fungi are a prominent and ubiquitous feature of forest soils, forming symbioses with most tree species, yet little is known about the magnitude of their impact on forest carbon cycles. A subset of EM fungi form dense, perennial aggregations of hyphae, which have elevated respiration rates compared with neighboring non-mat soils. These mats are a foci of EM activity and thereby a natural laboratory for examining how EM fungi impact forest soils. In order to constrain the contributions of EM fungi to forest soil respiration, we quantified the proportion of respiration derived from EM mat soils in an old-growth Douglas-fir stand in western Oregon. One dominant genus of mat-forming fungi, Piloderma, covered 56% of the soil surface area. Piloderma mats were monitored for respiration rates over 15 months and found to have on average 10% higher respiration than non-mat soil. At the stand level, this amounts to roughly 6% of soil respiration due to the presence of Piloderma mats. We calculate that these mats may constitute 27% of autotrophic respiration, based on respiration rates from trenched plots in a neighboring forest stand. Furthermore, enzyme activity and microbial community profiles in mat and non-mat soil provide evidence that specialized communities utilizing chitin contribute to this increased efflux. With 60% higher chitinase activity in mats, the breakdown of chitin is likely an important carbon flux while providing carbon and nitrogen to the microbial communities associated with mats. Quantitative PCR showed similar populations of fungi and bacteria in mat and non-mat soils; however, community analysis revealed distinct fungal and bacterial communities in the two soil types. The higher respiration associated with EM mats does not appear to be due only to a proliferation of EM fungi, but to a shift in overall community composition to organisms that efficiently utilize the unique resources available within the mat, including plant and
Investigation of VEGGIE Root Mat

Science.gov (United States)

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
Isolation of Leptospira santarosai, serovar guaricura from buffaloes (Bubalus bubalis in Vale do Ribeira, São Paulo, Brazil

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Vasconcellos Silvio A.

2001-01-01

Full Text Available In April 1998 urine samples from adult female buffaloes were collected in a farm located in Registro, Vale do Ribeira, São Paulo State, Brazil. The urine samples obtained after furosemide injection were immediately transported to the laboratory in liquid modified EMJH medium and seeded, by the serial dilution technique, into Fletcher's or modified EMJH-0.2% agar, both of them with 5-fluorouracil 100mg/mL. The intraperitoneoum inoculation of 0.5 mL was also performed with each urine sample in young, adult hamsters (Mesocricetus auratus. All samples seeded directly in culture medium were contaminated. The hamsters did not show any sign of disease and were killed at the 21st post inoculation day. At this time kidney cultures of these animals were performed and from one of them, one leptospira strain (M04-98 was isolated, identified as belonging to serogroup Sejroe by Microscopic Agglutination Test (MAT with a panel of 36 rabbit sera against serovars representative for the pathogenic serogroups. Subsequently, MAT was carried out with antisera against the 19 reference strains of serogroup Sejroe, revealing a close relationship with serovar guaricura. Afterwards the MAT was done with a panel of 18 monoclonal antibodies representative for serovars of serogroup Sejroe. The histogram closely resembled that of serovar guaricura. So Cross Agglutination Absorption Test (CAAT was carried out with the buffalo isolate and serovar guaricura, supporting the relationship between the buffalo isolate and serovar guaricura.
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

Science.gov (United States)

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.
Determination of triiodothyronine using RIA-Mat T3 kit

International Nuclear Information System (INIS)

Hara, Masao

1975-01-01

A RIA-Mat T 3 kit was used for an in vitro measurement of triiodothyronine in serum. A resin strip was utilized to absorb free triiodothyronine after the serum was incubated with antibody against triiodothyronine. This test was easy to manipulate and the reproducibility test with same sera, dilution test, and recovery test were also satisfactory. The normal range of triiodothyronine determined with this test kit was 119 +- 40 ng/dl using 50 test sera. Ninety sera with various thyroid diseases were also determined. (auth.)
Experimental Studies on Geocells and Mat Systems for Stabilization of Unpaved Shoulders and Temporary Roads

Science.gov (United States)

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

Science.gov (United States)

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.

Fabrication and Characterization of Electrospun Polycaprolactone Blended with Chitosan-Gelatin Complex Nanofibrous Mats

Directory of Open Access Journals (Sweden)

Yongfang Qian

2014-01-01

Full Text Available Design and fabrication of nanofibrous scaffolds should mimic the native extracellular matrix. This study is aimed at investigating electrospinning of polycaprolactone (PCL blended with chitosan-gelatin complex. The morphologies were observed from scanning electron microscope. As-spun blended mats had thinner fibers than pure PCL. X-ray diffraction was used to analyze the degree of crystallinity. The intensity at two peaks at 2θ of 21° and 23.5° gradually decreased with the percentage of chitosan-gelatin complex increasing. Moreover, incorporation of the complex could obviously improve the hydrophilicity of as-spun blended mats. Mechanical properties of as-spun nanofibrous mats were also tested. The elongation at break of fibrous mats increased with the PCL content increasing and the ultimate tensile strength varied with different weight ratios. The as-spun mats had higher tensile strength when the weight ratio of PCL to CS-Gel was 75/25 compared to pure PCL. Both as-spun PCL scaffolds and PCL/CS-Gel scaffolds supported the proliferation of porcine iliac endothelial cells, and PCL/CS-Gel had better cell viability than pure PCL. Therefore, electrospun PCL/Chitosan-gelatin nanofibrous mats with weight ratio of 75/25 have better hydrophilicity mechanical properties, and cell proliferation and thus would be a promising candidate for tissue engineering scaffolds.
Occurrence of anti-Toxoplasma gondii antibodies in greater rheas (Rhea americana) at the Reproduction Centre for Wild Animals in Mossoró, Rio Grande do Norte, Brazil

OpenAIRE

SOARES, H.S.; ALVES, N.D.; PEREIRA, R.H.M.A.; MATOS, S.M.; PENA, H.F.J.; GENNARI, S.M.; FEIJÓ, F.M.C.; AMÓRA, S.S.A.; PEIXOTO, G.C.X.

2010-01-01

Anti-Toxoplasma gondii antibodies were evaluated in greater rheas (Rhea americana) from the Reproduction Centre for Wild Animals located at the Universidade Federal Rural do Semiárido in the city of Mossoró, Rio Grande do Norte, by the modified agglutination test (MAT ≥25). It was verified that, from the 69 examined birds, 4.3% (three rheas) tested positive. The research about ratites toxoplasmoses are scarce, this way, the results showed the importance of the T. gondii diagnosis ...
Proposed method for agglutinating antibody titer analysis and its use as indicator of acquired immunity in pacu, Piaractus mesopotamicus

Directory of Open Access Journals (Sweden)

JD Biller-Takahashi

Full Text Available Antibody can be assessed by agglutinating antibody titer which is a quantitative measure of circulating antibodies in serum from fish previously immunized. The antibody evaluation has been performed with different fish species, and is considered a reliable method that can be applied to confirm several hypothesis regarding acquired immunity, even in conjunction with precise methods to describe immune mechanisms. In order to provide appropriate analytical methods for future studies on the specific immune system of native fish, the present study standardized on assay to measure the serum agglutinating antibody titer produced after immunization with inactivated A. hydrophila and levamisole administration in pacu. It was possible to determine the agglutinating antibodies titer in a satisfactorily way in pacu immunized with inactive A. hydrophila, and the highest titers were observed on fish fed with levamisole.
Spatial patterns of cyanobacterial mat growth on sand ripples

Science.gov (United States)

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.
Novel platelet-agglutinating protein from a thrombotic thrombocytopenic purpura plasma.

OpenAIRE

Siddiqui, F A; Lian, E C

1985-01-01

A novel platelet-agglutinating protein (PAP) was purified approximately 2,000-fold from the plasma of a patient with thrombotic thrombocytopenic purpura (TTP) by ammonium sulfate fractionation, DEAE-Sephacel and concanavalin A-Sepharose chromatographies. On sodium dodecyl sulfate-polyacrylamide gel electrophoresis, with and without reduction, this preparation revealed a major protein band with a molecular weight of 37,000, and a minor band with a molecular weight of 32,000-34,000. After eluti...
DECIPHERING LEPTOSPIROSIS-A DIAGNOSTIC MYSTERY: AN INSIGHT

Directory of Open Access Journals (Sweden)

Mohit Bhatia, B L Umapathy

2015-07-01

Full Text Available Leptospirosis is an emerging infectious disease which has been recognized as the most common zoonotic infection in the world. It affects human beings and many other species of vertebrates .Most commonly, the infection is acquired by direct or indirect exposure to urine of reservoir animals through contaminated soil, mud & water entering via small abrasions or breaches in the skin & mucous membranes during occupational, recreational or vocational activities. The signs & symptoms resemble a wide range of bacterial & viral diseases & sometimes can present as food poisoning, chemical poisoning & snake bite also due to which the diagnosis is often missed. This review article aims to focus on the role of Dark Field Microscopy (DFM, culture, Enzyme Linked Immuno Sorbent Assay (ELISA, Macroscopic Slide Agglutination test (MSAT, Microscopic Agglutination Test (MAT and Faine’s criteria in the diagnosis of leptospirosis.
Projet ViscoMatData

OpenAIRE

ENGUENG,; ABIB,

2009-01-01

ViscoMatData est un logiciel extranet d'une gestion d'une base de données multilingue sur les propriétés des matériaux viscoélastiques des chaussées. Ce rapport constitue l'un des livrables de la deuxième partie de ce projet. Pour présenter le travail réalisé durant cette deuxième partie, nous commencerons par faire un rappel sur le contexte du projet et le projet et le projet lui-même. Puis, nous nous intéresserons à l'architecture mise en place pour le développement, la réalisation et nous ...
Beaded Fiber Mats of PVA Containing Unsaturated Heteropoly Salt

Institute of Scientific and Technical Information of China (English)

Guo Cheng YANG; Yan PAN; Jian GONG; Chang Lu SHAO; Shang Bin WEN; Chen SHAO; Lun Yu QU

2004-01-01

Poly(vinyl alcohol) (PVA) fiber mats containing unsaturated heteropoly salt was prepared for the first time. IR, X-ray diffraction and SEM photographs characterized the beaded fiber mats.The viscoelasticity and the conductivity of the solution were the key factors that influence the formation of the beaded fiber mats.
Two-step activation of meiosis by the mat1 locus in Schizosaccharomyces pombe

DEFF Research Database (Denmark)

Willer, M; Hoffmann, Ulla-Lisbeth; Styrkársdóttir, U

1995-01-01

in which the mat1 locus plays two roles in controlling meiosis. In the first instance, the mat1-Pc and mat1-Mc functions are required to produce the mating pheromones and receptors that allow the generation of a pheromone signal. This signal is required to induce the expression of mat1-Pm and mat1-Mm......The mat1 locus is a key regulator of both conjugation and meiosis in the fission yeast Schizosaccharomyces pombe. Two alternative DNA segments of this locus, mat1-P and mat1-M, specify the haploid cell types (Plus and Minus). Each segment includes two genes: mat1-P includes mat1-Pc and mat1-Pm....... This appears to be the major pheromone-dependent step in controlling meiosis since ectopic expression of these genes allows meiosis in the absence of mat1-Pc and mat1-Mc. The mat1-Pm and mat1-Mm products complete the initiation of meiosis by activating transcription of the mei3 gene....
Prevalence of agglutinating antibodies to Sarcocystis neurona in skunks (Mephitis Mephitis), raccoons (Procyon lotor), and opossums (Didelphis Virginiana) from Connecticut.

Science.gov (United States)

Mitchell, Sheila M; Richardson, Dennis J; Cheadle, M Andy; Zajac, Anne M; Lindsay, David S

2002-10-01

Equine protozoal myeloencephalitis is the most important protozoan disease of horses in North America and is usually caused by Sarcocystis neurona. Natural cases of encephalitis caused by S. neurona have been reported in skunks (Mephitis mephitis) and raccoons (Procyon lotor). Opossums (Didelphis spp.) are the only known definitive host. Sera from 24 striped skunks, 12 raccoons, and 7 opossums (D. virginiana) from Connecticut were examined for agglutinating antibodies to S. neurona using the S. neurona agglutination test (SAT) employing formalin-fixed merozoites as antigen. The SAT was validated for skunk sera using pre- and postinfection serum samples from 2 experimentally infected skunks. Of the 24 (46%) skunks 11 were positive, and all 12 raccoons were positive for S. neurona antibodies. None of the 7 opossums was positive for antibodies to S. neurona. These results suggest that exposure to sporocysts of S. neurona by intermediate hosts is high in Connecticut. The absence of antibodies in opossums collected from the same areas is most likely because of the absence of systemic infection in the definitive host.
Mucoadhesive electrospun chitosan-based nanofibre mats for dental caries prevention.

Science.gov (United States)

Samprasit, Wipada; Kaomongkolgit, Ruchadaporn; Sukma, Monrudee; Rojanarata, Theerasak; Ngawhirunpat, Tanasait; Opanasopit, Praneet

2015-03-06

The mucoadhesive electrospun nanofibre mats were developed using chitosan (CS) and thiolated chitosan (CS-SH) as mucoadhesive polymers. Garcinia mangostana (GM) extract was incorporated into nanofibre mats. The antibacterial activity in the single and combined agents was evaluated against dental caries pathogens. The morphology of mats was observed using SEM. The mats were evaluated for GM extract amount, mucoadhesion, in vitro release, antibacterial activity and cytotoxicity. The mucoadhesion and antibacterial activity were determined in healthy human volunteers. The prepared mats were in nanoscale with good physical and mucoadhesive properties. The CS-SH caused the higher mucoadhesion. All mats rapidly released active substances, which had the synergistic antibacterial activity. In addition, the reduction of bacteria and good mucoadhesion in the oral cavity occurred without cytotoxicity. The results suggest that mats have the potential to be mucoadhesive dosage forms to maintain oral hygiene by reducing the bacterial growth that causes the dental caries. Copyright © 2014 Elsevier Ltd. All rights reserved.
Polycaprolactone-Chitin Nanofibrous Mats as Potential Scaffolds for Tissue Engineering

Directory of Open Access Journals (Sweden)

Min Sup Kim

2012-01-01

Full Text Available We describe here the preparation of poly(caprolactone (PCL-chitin nanofibrous mats by electrospinning from a blended solution of PCL and chitin dissolved in a cosolvent, 1,1,1,3,3,3-hexafluoro-2-propanol and trifluoroacetic acid. Scanning electron microscopy showed that the neutralized PCL-chitin nanofibrous mats were morphologically stable, with a mean diameter of 340.5±2.6 nm, compared with a diameter of 524.2±12.1 nm for PCL mats. The nanofibrous mats showed decreased water contact angles as the proportion of chitin increased. However, the tensile properties of nanofibrous mats containing 30~50% (wt/wt chitin were enhanced compared with PCL-only mats. In vitro studies showed that the viability of human dermal fibroblasts (HDFs for up to 7 days in culture was higher on composite (OD value: 1.42±0.09 than on PCL-only (0.51±0.14 nanofibrous mats, with viability correlated with chitin concentration. Together, our results suggest that PCL-chitin nanofibrous mats can be used as an implantable substrate to modulate HDF viability in tissue engineering.
Testlet-Based Multidimensional Adaptive Testing.

Science.gov (United States)

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.
Testlet-based Multidimensional Adaptive Testing

Directory of Open Access Journals (Sweden)

Andreas Frey

2016-11-01

Full Text Available 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, 1.5 and testlet sizes (3 items, 6 items, 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.
Microbial communities and exopolysaccharides from Polynesian mats.

Science.gov (United States)

Rougeaux, H; Guezennec, M; Che, L M; Payri, C; Deslandes, E; Guezennec, J

2001-03-01

Microbial mats present in two shallow atolls of French Polynesia were characterized by high amounts of exopolysaccharides associated with cyanobacteria as the predominating species. Cyanobacteria were found in the first centimeters of the gelatinous mats, whereas deeper layers showing the occurrence of the sulfate reducers Desulfovibrio and Desulfobacter species as determined by the presence of specific biomarkers. Exopolysaccharides were extracted from these mats and partially characterized. All fractions contained both neutral sugars and uronic acids with a predominance of the former. The large diversity in monosaccharides can be interpreted as the result of exopolymer biosynthesis by either different or unidentified cyanobacterial species.
Prevalence of antibodies to Trypanosoma cruzi, Toxoplasma gondii, Encephalitozoon cuniculi, Sarcocystis neurona, Besnoitia darlingi, and Neospora caninum in North American opossums, Didelphis virginiana, from southern Louisiana.

Science.gov (United States)

Houk, Alice E; Goodwin, David G; Zajac, Anne M; Barr, Stephen C; Dubey, J P; Lindsay, David S

2010-12-01

We examined the prevalence of antibodies to zoonotic protozoan parasites ( Trypanosoma cruzi, Toxoplasma gondii, and Encephalitozoon cuniculi) and protozoans of veterinary importance ( Neospora caninum, Sarcocystis neurona, and Besnoitia darlingi) in a population of North American opossums ( Didelphis virginiana) from Louisiana. Samples from 30 opossums were collected as part of a survey for T. cruzi in Louisiana. Frozen sera from these 30 opossums were examined using an indirect immunofluorescent antibody test (IFAT) against in vitro-produced antigenic stages of these protozoans. Additionally, 24 of the 30 samples were examined using hemoculture, and all 30 were examined in the modified direct agglutination test (MAT) for antibodies to To. gondii. The prevalences of reactive IFAT samples were as follows: 60% for T. cruzi, 27% for To. gondii, 23% for E. cuniculi, 17% for S. neurona, 47% for B. darlingi, and 0% for N. caninum. Hemoculture revealed that 16 (67%) of 24 samples were positive for T. cruzi, compared to 18 of 30 (60%) by IFAT. The sensitivity and specificity for the IFAT compared to hemoculture was 100% for each. The modified direct agglutination test revealed that 9 (30%) of the 30 samples from opossums had antibodies to To. gondii , compared to 8 (27%) using the IFAT. The sensitivity and specificity of the IFAT compared to the MAT was 100% and 72%, respectively.
Serological investigation of Leptospira infection and its circulation in one intensive-type water buffalo farm in the Philippines.

Science.gov (United States)

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 (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.
Photocatalytic and antibacterial properties of a TiO2/nylon-6 electrospun nanocomposite mat containing silver nanoparticles

International Nuclear Information System (INIS)

Pant, Hem Raj; Pandeya, Dipendra Raj; Nam, Ki Taek; Baek, Woo-il; Hong, Seong Tshool; Kim, Hak Yong

2011-01-01

Silver-impregnated TiO 2 /nylon-6 nanocomposite mats exhibit excellent characteristics as a filter media with good photocatalytic and antibacterial properties and durability for repeated use. Silver nanoparticles (NPs) were successfully embedded in electrospun TiO 2 /nylon-6 composite nanofibers through the photocatalytic reduction of silver nitrate solution under UV-light irradiation. TiO 2 NPs present in nylon-6 solution were able to cause the formation of a high aspect ratio spider-wave-like structure during electrospinning and facilitated the UV photoreduction of AgNO 3 to Ag. TEM images, UV-visible and XRD spectra confirmed that monodisperse Ag NPs (approximately 4 nm in size) were deposited selectively upon the TiO 2 NPs of the prepared nanocomposite mat. The antibacterial property of a TiO 2 /nylon-6 composite mat loaded with Ag NPs was tested against Escherichia coli, and the photoactive property was tested against methylene blue. All of the results showed that TiO 2 /nylon-6 nanocomposite mats loaded with Ag NPs are more effective than composite mats without Ag NPs. The prepared material has potential as an economically friendly photocatalyst and water filter media because it allows the NPs to be reused.
Use of commercial extenders and alternatives to prevent sperm agglutination for cryopreservation of brown bear semen.

Science.gov (United States)

Gomes-Alves, S; Alvarez, M; Nicolas, M; Lopez-Urueña, E; Martínez-Rodríguez, C; Borragan, S; de Paz, P; Anel, L

2014-08-01

The objective of this study was to evaluate different bovine and canine commercial semen extenders for cryopreservation of brown bear ejaculates and the effect of semen collection directly into extender on sperm agglutination. Semen samples were obtained by electroejaculation from 13 adult males. In experiment 1, eleven ejaculates from eight bears were used to evaluate Bioxcell and Andromed as extenders, whereas in experiment 2, nine ejaculates from six bears were used to evaluate Triladyl canine, CaniPro, and Extender 2 as extenders. An extender specifically developed for brown bears (Test-Tris-fructose-egg yolk-glycerol, TTF-ULE/bear) served as a control extender in both experiments. After thawing, total and progressive sperm motility and sperm viability were greater (P bear and Andromed extenders than for Bioxcell in experiment 1 and greater (P bear extender than for Triladyl Canine, CaniPro, and Extender 2 in experiment 2. In experiment 3, addition of handling extender (TTF-H) to the semen collection tube for eight ejaculates from seven bears resulted in less (P bear is the most suitable extender for brown bear semen cryopreservation, but comparable results can be obtained with the commercial extender Andromed. In addition, collection of ejaculates directly in TTF-H extender decreases sperm agglutination in fresh samples. Copyright © 2014 Elsevier Inc. All rights reserved.
Characterizing Microbial Mat Morphology with Structure from Motion Techniques in Ice-Covered Lake Joyce, McMurdo Dry Valleys, Antarctica

Science.gov (United States)

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

Developing DNA barcoding (matK) primers for marama bean ...

African Journals Online (AJOL)

The homology found with Tylosema fassoglensis (trnK gene) and Pisum sativum (matK gene) suggests that an identical region was amplified for Tylosema esculentum. A phylogenetic tree was constructed based on the matK sequences and the results suggest that the matK region can also be used in determining levels of ...
Influence of layer-by-layer assembled electrospun poly (L-lactic acid) nanofiber mats on the bioactivity of endothelial cells

Energy Technology Data Exchange (ETDEWEB)

Wu, Keke; Zhang, Xiazhi; Yang, Wufeng; Liu, Xiaoyan; Jiao, Yanpeng, E-mail: tjiaoyp@jnu.edu.cn; Zhou, Changren

2016-12-30

Highlights: • Layer-by-layer assembled PLLA nanofiber mats were successfully prepared. • The modified PLLA nanofiber mats enhanced the adhesion, proliferation of endothelial cells. • The modified PLLA nanofiber mats had inhibited the inflammatory response to some extent. - Abstract: 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.
Diversity and stratification of archaea in a hypersaline microbial mat.

Science.gov (United States)

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.
SEROLOGICAL AND MOLECULAR SURVEY OF Leptospira spp. AMONG CART HORSES FROM AN ENDEMIC AREA OF HUMAN LEPTOSPIROSIS IN CURITIBA, SOUTHERN BRAZIL

Directory of Open Access Journals (Sweden)

Mariane Angélica Finger

2014-12-01

Full Text Available 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.
Targeting S-adenosylmethionine biosynthesis with a novel allosteric inhibitor of Mat2A

Energy Technology Data Exchange (ETDEWEB)

Quinlan, Casey L.; Kaiser, Stephen E.; Bolaños, Ben; Nowlin, Dawn; Grantner, Rita; Karlicek-Bryant, Shannon; Feng, Jun Li; Jenkinson, Stephen; Freeman-Cook, Kevin; Dann, Stephen G.; Wang, Xiaoli; Wells, Peter A.; Fantin, Valeria R.; Stewart, Al E.; Grant, Stephan K. (Pfizer)

2017-05-29

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 enzyme 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.
MatLab Programming for Engineers Having No Formal Programming Knowledge

Science.gov (United States)

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.
Les humains sont-ils des entités matérielles ?

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Tauveron Matthias

2012-07-01

Full Text Available Nous étudions la sémantique des noms d’humains dans le lexique français. Dans la littérature, ces noms ont un positionnement indéterminé ou ambigu par rapport au critère concret/abstrait. Ce fait est regrettable car ce critère est considéré comme fondamental. Nous montrons leur positionnement particulier vis-à-vis de ce critère au travers de l’étude de métaphores attestées en corpus dans divers textes écrits. Nous suivons l’optique de Lakoff et Johnson en considérant que la métaphore est un révélateur des catégories de pensée. Dans cet esprit, la question est de savoir si les humains sont des entités matérielles ou non. L’étude est menée sur deux paramètres définitoires des entités matérielles : la masse et la spatialité. Nous apportons des caractérisations lexicales de ces deux propriétés. La masse est envisagée généralement, autour des noms, adjectifs et verbes relevés dans les dictionnaires. Nous proposons une synthèse des divers paramètres dénotant la spatialité dans la littérature, sous la forme de six points indépendants (forme, intérieur/extérieur, sous-parties, changement de posture, localisation, déplacement. L’étude de la spatialité est menée systématiquement dans ces directions grâce à des tests issus des caractérisations lexicales de ces aspects. Les tests font voir que, si les humains sont dotés d’une certaine dimension matérielle (qu’ils partagent ainsi avec les objets concrets, ils ont également au moins trois autres dimensions qui font qu’ils ne se réduisent pas à des objets matériels. Nous montrons ainsi que l’humain est, dans le lexique français, doté d’une multiplicité ontologique : en plus d’une dimension matérielle, il dispose d’une dimension psychologique, une dimension praxéologique et une dimension sociale. De plus, l’étude des métaphores montre que la dimension matérielle est souvent réduite voire anéantie par rapport aux
Diazotrophic microbial mats

NARCIS (Netherlands)

Severin, I.; Stal, L.J.; Seckbach, J.; Oren, A.

2010-01-01

Microbial mats have been the focus of scientific research for a few decades. These small-scale ecosystems are examples of versatile benthic communities of microorganisms, usually dominated by phototrophic bacteria (e.g., Krumbein et al., 1977; Jørgensen et al., 1983). They develop as vertically
Leptospirosis serosurvey in bovines from Brazilian Pantanal using IGG ELISA with recombinant protein LipL32 and microscopic agglutination test Sorodiagnóstico de leptospirose em bovinos do Pantanal brasileiro utilizando ELISA IgG com proteína recombinante LipL32 e soroaglutinação microscópica

Directory of Open Access Journals (Sweden)

Renata Graça Pinto Tomich

2007-12-01

Full Text Available This investigation was carried out in Brazilian Pantanal: region with important biodiversity. This region's climatic conditions, hydrology and geomorphology as well as the existence of great variety of wild species favor the maintenance of the Leptospira in the environment. The aim of this study was to evaluate IgG ELISA with recombinant protein LipL32 in comparison with microscopic agglutination test (MAT and additionally contribute to the knowledge of the distribution of the one of most important worldwide zoonotic infection, assessing the seropositivity of bovine leptospirosis in beef cattle herds of Brazilian Pantanal, an important ecological preserved area, where cattle constitute not only the most important economic resource but also the major activity compatible of the conservation of natural resource of the region. Out of 282 samples of cattle serum analyzed, 143 (50.71% were positive in MAT. The serovar Hardjo (genotypic Hardjoprajitno and Hardjobovis, Wolffi and Ballum showed the largest frequency of reactive samples. In the IgG ELISA rLipL32, 161 samples (57.09% were positive. This result was higher than obtained by MAT (pEste estudo foi realizado no Pantanal brasileiro: região que apresenta importante biodiversidade. As condições de clima, hidrologia e geomorfologia dessa região, bem como a existência de grande variedade de espécies animais silvestres, favorecem a manutenção da Leptospira no meio ambiente. O objetivo desse estudo foi avaliar o ELISA IgG com proteína recombinante LipL32 em comparação com a soroaglutinação microscópica (SAM para o diagnóstico sorológico de Leptospira. Adicionalmente, contribuir para o conhecimento da distribuição da leptospirose bovina, uma das mais importantes zoonoses mundialmente distribuída. Foi avaliada a soropositividade para essa bactéria em rebanhos bovinos de corte da região do Pantanal, uma área onde o bovino constitui não apenas o recurso econômico mais importante
Accuracy of Jump-Mat Systems for Measuring Jump Height.

Science.gov (United States)

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.
Method for production of carbon nanofiber mat or carbon paper

Science.gov (United States)

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.
Misidentification of Vibrio cholerae O155 isolated from imported shrimp as O serogroup O139 due to cross-agglutination with commercial O139 antisera

DEFF Research Database (Denmark)

Dalsgaard, A.; Mazur, J.; Dalsgaard, Inger

2002-01-01

. The strain contained two plasmids, in contrast to other O139 strains, which normally do not contain plasmids. The characteristics of the strain led to further agglutination testing with other antisera that are not commercially available, and the strain was found to agglutinate O155 antiserum in repeated...... was isolated from imported raw frozen shrimp. The toxigenicity of the strain was analyzed, and the results of a polymerase chain reaction showed that the V. cholerae strain did not contain the virulence genes ctx, tcp9, and zot, which are normally found in V. cholerae O1 and O139. The strain was resistant...... to colistin and spectinomycin. The high susceptibility of the strain to antimicrobial agents was confirmed by the lack of an SXT element, a self-transmissible, chromosomal genetic element that is normally present in O139 strains and encodes resistance to sulfonamides, trimethoprim, and streptomycin...
Microbial mat ecosystems: Structure types, functional diversity, and biotechnological application

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Cristina M. Prieto-Barajas

2018-01-01

Full Text Available Microbial mats are horizontally stratified microbial communities, exhibiting a structure defined by physiochemical gradients, which models microbial diversity, physiological activities, and their dynamics as a whole system. These ecosystems are commonly associated with aquatic habitats, including hot springs, hypersaline ponds, and intertidal coastal zones and oligotrophic environments, all of them harbour phototrophic mats and other environments such as acidic hot springs or acid mine drainage harbour non-photosynthetic mats. This review analyses the complex structure, diversity, and interactions between the microorganisms that form the framework of different types of microbial mats located around the globe. Furthermore, the many tools that allow studying microbial mats in depth and their potential biotechnological applications are discussed.
Impacts of papain and neuraminidase enzyme treatment on electrohydrodynamics and IgG-mediated agglutination of type A red blood cells.

Science.gov (United States)

Hyono, Atsushi; Gaboriaud, Fabien; Mazda, Toshio; Takata, Youichi; Ohshima, Hiroyuki; Duval, Jérôme F L

2009-09-15

The stability of native and enzyme-treated human red blood cells of type A (Rh D positive) against agglutination is investigated under conditions where it is mediated by immunoglobuline G (IgG) anti-D antibody binding. The propensity of cells to agglutinate is related to their interphasic (electrokinetic) properties. These properties significantly depend on the concentration of proteolytic papain enzyme and protease-free neuraminidase enzyme that the cells are exposed to. The analysis is based on the interpretation of electrophoretic data of cells by means of the numerical theory for the electrokinetics of soft (bio)particles. A significant reduction of the hydrodynamic permeability of the external soft glycoprotein layer of the cells is reported under the action of papain. This reflects a significant decrease in soft surface layer thickness and a loss in cell surface integrity/rigidity, as confirmed by nanomechanical AFM analysis. Neuraminidase action leads to an important decrease in the interphase charge density by removing sialic acids from the cell soft surface layer. This is accompanied by hydrodynamic softness modulations less significant than those observed for papain-treated cells. On the basis of these electrohydrodynamic characteristics, the overall interaction potential profiles between two native cells and two enzyme-treated cells are derived as a function of the soft surface layer thickness in the Debye-Hückel limit that is valid for cell suspensions under physiological conditions (approximately 0.16 M). The thermodynamic computation of cell suspension stability against IgG-mediated agglutination then reveals that a decrease in the cell surface layer thickness is more favorable than a decrease in interphase charge density for inducing agglutination. This is experimentally confirmed by agglutination data collected for papain- and neuraminidase-treated cells.
Prevalence of agglutinating antibodies to Toxoplasma gondii and Sarcocystis neurona in beavers (Castor canadensis) from Massachusetts

Science.gov (United States)

Jordan, C.N.; Kaur, T.; Koenen, K.; DeStefano, S.; Zajac, A.M.; Lindsay, D.S.

2005-01-01

The present study examined the seroprevalence of Toxoplasma gondii and Sarcocystls neurona in a population of beavers (Castor canadensis) from Massachusetts. Sixty-two blood samples were collected during the field seasons over 3 consecutive years from different animals. Blood was collected onto filter paper and shipped to the Department of Biomedical Sciences, Virginia Tech, Blacksburg, Virginia, for parasite testing. The samples were tested at dilutions of 1:25, 1:50, and 1:100 against each parasite antigen by modified agglutination tests to determine whether antibodies to either parasite were present in the blood. Six of 62 samples (10%) were positive for T. gondii, with 2 samples having titers of 1:25 and 4 having titers of 1:50. Four of 62 samples (6%) were positive for S. neurona, with 2 samples having titers of 1:25 and 2 having titers of 1:50. ?? American Society of Pathologists 2005.
Contributions of ectomycorrhizal fungal mats to forest soil respiration

Science.gov (United States)

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 âmatsâ, 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...
Photocatalytic and antibacterial properties of a TiO{sub 2}/nylon-6 electrospun nanocomposite mat containing silver nanoparticles

Energy Technology Data Exchange (ETDEWEB)

Pant, Hem Raj [Department of Bionanosystem Engineering, Chonbuk National University, Jeonju 561-756 (Korea, Republic of); Department of Engineering Science and Humanities, Institute of Engineering, Pulchowk Campus, Tribhuvan University, Kathmandu (Nepal); Pandeya, Dipendra Raj [Department of Microbiology and Immunology, Institute for Medical Science, Chonbuk National University, Jeonju, 561-756 (Korea, Republic of); Nam, Ki Taek; Baek, Woo-il [Department of Textile Engineering, Chonbuk National University, Jeonju 561-756 (Korea, Republic of); Hong, Seong Tshool [Department of Microbiology and Immunology, Institute for Medical Science, Chonbuk National University, Jeonju, 561-756 (Korea, Republic of); Kim, Hak Yong, E-mail: khy@jbnu.ac.kr [Department of Textile Engineering, Chonbuk National University, Jeonju 561-756 (Korea, Republic of)

2011-05-15

Silver-impregnated TiO{sub 2}/nylon-6 nanocomposite mats exhibit excellent characteristics as a filter media with good photocatalytic and antibacterial properties and durability for repeated use. Silver nanoparticles (NPs) were successfully embedded in electrospun TiO{sub 2}/nylon-6 composite nanofibers through the photocatalytic reduction of silver nitrate solution under UV-light irradiation. TiO{sub 2} NPs present in nylon-6 solution were able to cause the formation of a high aspect ratio spider-wave-like structure during electrospinning and facilitated the UV photoreduction of AgNO{sub 3} to Ag. TEM images, UV-visible and XRD spectra confirmed that monodisperse Ag NPs (approximately 4 nm in size) were deposited selectively upon the TiO{sub 2} NPs of the prepared nanocomposite mat. The antibacterial property of a TiO{sub 2}/nylon-6 composite mat loaded with Ag NPs was tested against Escherichia coli, and the photoactive property was tested against methylene blue. All of the results showed that TiO{sub 2}/nylon-6 nanocomposite mats loaded with Ag NPs are more effective than composite mats without Ag NPs. The prepared material has potential as an economically friendly photocatalyst and water filter media because it allows the NPs to be reused.
Total mercury and methyl-mercury contents and accumulation in polar microbial mats.

Science.gov (United States)

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

Science.gov (United States)

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

Science.gov (United States)

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.

Prevalence of Toxoplasma gondii antibodies in domestic donkeys (Equus asinus) in Durango, Mexico slaughtered for human consumption

OpenAIRE

Alvarado-Esquivel, Cosme; Alvarado-Esquivel, Domingo; Dubey, Jitender P

2015-01-01

Background Nothing is known about Toxoplasma gondii prevalence in donkeys in Mexico. Meat from donkey is consumed by humans in Mexico and also exported to other countries. We sought to determine the presence of antibodies against T. gondii in 239 domestic donkeys (Equus asinus) for slaughter in Durango, Mexico using the modified agglutination test (MAT). Donkeys were sampled in four premises (trade centers) where donkeys were gather for shipment to abattoirs in other Mexican states. Results A...
Water flow and solute transport in floating fen root mats

Science.gov (United States)

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
On a grain of sand - a microhabitat for the opportunistic agglutinated foraminifera Hemisphaerammina apta n. sp., from the early Eocene Arctic Ocean

Science.gov (United States)

McNeil, David H.; Neville, Lisa A.

2018-02-01

Hemisphaerammina apta n. sp. is an attached monothalamous agglutinated foraminifera discovered in shelf sediments of the early Eocene Arctic Ocean. It is a simple yet distinctive component of the endemic agglutinated foraminiferal assemblage that colonized the Arctic Ocean after the microfaunal turnover caused by the Paleocene-Eocene Thermal Maximum. Associated foraminifera are characterized by a high percentage of monothalamous species (up to 60 %) and are entirely agglutinated indicating a brackish (mesohaline) early Eocene Arctic Ocean. Hemisphaerammina apta occurs exclusively as individuals attached to fine detrital grains (0.2 to 1.8 mm) of sediment. It is a small species (0.06 to 0.2 mm in diameter), fine-grained, with a low hemispherical profile, no floor across the attachment area, no substantive marginal flange, no internal structures, and no aperture. Lacking an aperture, it apparently propagated and fed through minute (micrometre-sized) interstitial pores in the test wall. Attachment surfaces vary from concave to convex and rough to smooth. Grains for attachment are diverse in shape and type but are predominantly of quartz and chert. The presence of H. apta in the early Eocene was an opportunistic response to an environment with an active hydrological system (storm events). Attachment to grains of sand would provide a more stable base on a sea floor winnowed by storm-generated currents. Active transport is indicated by the relative abundance of reworked foraminifera mixed with in situ species. Contemporaneous reworking and colonization by H. apta is suggested by its attachment to a reworked specimen of Cretaceous foraminifera.
Microbial mat structures in profile: The Neoproterozoic Sonia Sandstone, Rajasthan, India

Science.gov (United States)

Samanta, Pradip; Mukhopadhyay, Soumik; Mondal, Anudeb; Sarkar, Subir

2011-01-01

Ubiquitous microorganisms, especially cyanobacteria preferably grow on the sediment surface thereby producing microbial mats. In the absence of grazers and bioturbators, microbial mat is a unique feature of the Proterozoic. Most of the papers so far published described a wide variety of bed surface microbial mat structures with rare illustrations from sections perpendicular to bedding. Nonetheless, bed surface exposures are relatively rare in rock records. This limitation of bed surface exposures in rock records suggest that a study of microbial mats in bed-across sections is needed. The 60 m thick coastal marine interval of the Sonia Sandstone Formation is bounded between two terrestrial intervals, a transgressive lag at the base and an unconformity at the top, and has been chosen for exploration of microbial mat structures in bed-across sections. A wide variety of microbial mat-induced structures in bed-across sections are preserved within the coastal interval of the Sonia Sandstone. Though many of these structures are similar in some aspects with bed surface structures, some of those presented here are new. The palaeogeographic range of these microbial structures extends from supralittoral to neritic. Diagenetic alterations of microbial mats produce pyrite and those zones are suitable for the preservation of microbial remains. SEM and EDAX analyses show fossil preservation of filamentous microbial remains that confirm the presence of microbial mats within the coastal interval of the Sonia Sandstone. Effects of proliferation of microbial mats in the siliciclastic depositional setting are numerous. The mat-cover on sediment surfaces hinders reworking and/or erosion of the sediments thereby increases the net sedimentation rate. Successive deposition and preservation of thick microbial mat layer under reducing environments should have a great potential for hydrocarbon production and preservation and therefore these Proterozoic formations could be a target for
Sperm Impairment by Sperm Agglutinating Factor Isolated from Escherichia coli: Receptor Specific Interactions

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Kiranjeet Kaur

2013-01-01

Full Text Available In an earlier work done in our laboratory, we have been able to isolate a sperm agglutinating strain of Escherichia coli from the semen sample of a male attending infertility clinic. Further, factor responsible for sperm agglutination (SAF was isolated and purified, and, using SAF as a tool, corresponding SAF binding receptor from human spermatozoa has been purified. Characterization of SAF and SAF binding receptor using MALDI-TOF showed homology to glutamate decarboxylase and MHC class I molecule, respectively. Coincubation of SAF with spermatozoa not only resulted in spermagglutination but could also compromise other sperm parameters, namely, Mg2+ dependent ATPase activity and apoptosis. Intravaginal administration of SAF could lead to infertility in Balb/c mice. SAF induced impairment of sperm parameters, and infertility was observed to be due to interaction of SAF with sperm surface receptor component as, when purified receptor was introduced, receptor completely inhibited all the detrimental effects induced by SAF. From these results, it could be concluded that interaction of SAF with spermatozoa is receptor mediated.
Functional and Expression Analyses of the Pneumocystis MAT Genes Suggest Obligate Sexuality through Primary Homothallism within Host Lungs

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S. Richard

2018-02-01

Full Text Available Fungi of the genus Pneumocystis are obligate parasites that colonize mammals’ lungs and are host species specific. Pneumocystis jirovecii and Pneumocystis carinii infect, respectively, humans and rats. They can turn into opportunistic pathogens in immunosuppressed hosts, causing severe pneumonia. Their cell cycle is poorly known, mainly because of the absence of an established method of culture in vitro. It is thought to include both asexual and sexual phases. Comparative genomic analysis suggested that their mode of sexual reproduction is primary homothallism involving a single mating type (MAT locus encompassing plus and minus genes (matMc, matMi, and matPi; Almeida et al., mBio 6:e02250-14, 2015. Thus, each strain would be capable of sexual reproduction alone (self-fertility. However, this is a working hypothesis derived from computational analyses that is, in addition, based on the genome sequences of single isolates. Here, we tested this hypothesis in the wet laboratory. The function of the P. jirovecii and P. carinii matMc genes was ascertained by restoration of sporulation in the corresponding mutant of fission yeast. Using PCR, we found the same single MAT locus in all P. jirovecii isolates and showed that all three MAT genes are often concomitantly expressed during pneumonia. Extensive homology searches did not identify other types of MAT transcription factors in the genomes or cis-acting motifs flanking the MAT locus that could have been involved in MAT switching or silencing. Our observations suggest that Pneumocystis sexuality through primary homothallism is obligate within host lungs to complete the cell cycle, i.e., produce asci necessary for airborne transmission to new hosts.
Utilization of MatPIV program to different geotechnical models

Science.gov (United States)

Aklik, P.; Idinger, G.

2009-04-01

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.
Two-step activation of meiosis by the mat1 locus in Schizosaccharomyces pombe

DEFF Research Database (Denmark)

Willer, M; Hoffmann, Ulla-Lisbeth; Styrkársdóttir, U

1995-01-01

of meiosis is based largely on indirect observations, and a more precise investigation of these events was required to define the interaction between the mat1 genes. Here we resolve this issue using synthetic pheromones and P/M strains with mutations in either mat1-Pc or mat1-Mc. Our results suggest a model...... in which the mat1 locus plays two roles in controlling meiosis. In the first instance, the mat1-Pc and mat1-Mc functions are required to produce the mating pheromones and receptors that allow the generation of a pheromone signal. This signal is required to induce the expression of mat1-Pm and mat1-Mm...
Storage of yerba maté in controlled atmosphere

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Sarah Lemos Cogo Prestes

2014-04-01

Full Text Available The aim of this study was to evaluate the effect of controlled atmosphere in the change of color, chlorophyll degradation and phenolic compounds concentration in yerba maté thickly ground (“cancheada” and thinly milled (“socada”. Yerba maté samples from the towns of Arvorezinha (RS - Brazil and São Mateus do Sul (PR - Brazil were stored in four levels of oxygen (1, 3, 6 and 20.9kPa of O2 and four levels of carbon dioxide (0, 3, 6 and 18kPa of CO2 and then were analyzed, after nine months of storage. According to the results, the O2 partial pressure reduction decreased the loss of green coloration, kept a higher content of chlorophylls and of total phenolic compounds. In relation to the different levels of CO2, a response as remarkable as O2 was not observed. The yerba maté that was thickly ground (“cancheada” presented a better storage potential than the one thinly milled (“socada” in the storage with O2 and with CO2. The 1kPa of O2 condition kept the yerba maté greener and with a higher content of chlorophylls and of total phenolic compounds after nine months of storage. The CO2 partial pressure kept the yerba maté coloration greener and with a higher content of chlorophylls and of total phenolic compounds, regardless of the level used, in the maté from both cultivation areas.
Critique de la dématérialisation

OpenAIRE

Robert , Pascal

2004-01-01

International audience; La notion de " dématérialisation " constitue actuellement l'une des pièces maîtresses de l'idéologie de la communication. Or, après enquête, nous constatons que la dématérialisation ne se rencontre ni dans les TIC ni dans les réseaux où se dévoilent en revanche un nouveau mode de matérialisation ainsi qu'un processus de virtualisation par changement d'échelle. Nous nous interrogeons donc sur la fonction sociale et politique que cette notion joue dans les discours qui l...
Fabrication of nanofiber mats from electrospinning of functionalized polymers

Science.gov (United States)

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

2014-08-01

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

International Nuclear Information System (INIS)

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

2014-01-01

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

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Nadeem Mohd

1995-01-01

Full Text Available Matting of hair been reported from time to time due to treatment of hair with detergent, shampoos, waving lotions, setting lotions and bleaches. A case of matting of hairs in a young girl due to a change in the brand of shampoo is reported.
Regulation of electron transfer processes affects phototrophic mat structure and activity

OpenAIRE

Ha, Phuc T.; Renslow, Ryan S.; Atci, Erhan; Reardon, Patrick N.; Lindemann, Stephen R.; Fredrickson, James K.; Call, Douglas R.; Beyenal, Haluk

2015-01-01

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

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

2017-09-13

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, 2017. © 2017 Wiley Periodicals, Inc.
Charpy V, an application in Mat lab

International Nuclear Information System (INIS)

Castillo M, J.A.; Torres V, M.

2003-01-01

The obtained results with the system Charpy V V 1 designed in Mat lab for the estimate of parameters of three mathematical models are shown. The adjustment of data is used to determine the fracture energy, the lateral expansion and the percentage of ductility of steels coming from the reactor vessels of Laguna Verde, Veracruz. The data come from test tubes type Charpy V of irradiated material and not irradiated. To verify our results they were compared with those obtained by General Electric of data coming from the Laguna Verde nuclear power plant. (Author)
A sperm-agglutinating lectin from seeds of Jack fruit (Artocarpus heterophyllus).

Science.gov (United States)

Namjuntra, P; Muanwongyathi, P; Chulavatnatol, M

1985-04-30

A lectin specific for N-acetylgalactosamine was isolated from seed extract of Jack fruit (Artocarpus heterophyllus) by ammonium sulfate precipitation, followed by affinity chromatography on a Affigel-galactosamine-agarose column. The lectin possessed agglutinating activities for human and rat sperm as well as human red blood cells. It was found to have Mr = 62,000 consisting of two dissimilar subunits of Mr = 18,000 and 13,000. It also cross-reacted with an antibody against the lectin of Osage Orange (Maclura pomifera).
Chitosan-rectorite nanospheres immobilized on polystyrene fibrous mats via alternate electrospinning/electrospraying techniques for copper ions adsorption

Science.gov (United States)

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.
MAT@USC Candidates and Latino English Language Learners

Science.gov (United States)

Lomeli, Cynthia Leticia

2012-01-01

The purpose of this study was to further understand the perceptions of MAT@USC teacher candidates and how their perceptions and previous experiences affect the educational experiences of Latino English language learners. Three questions were developed to guide this study: (1) What are the perceptions of MAT@USC candidates in selected courses…
Interaction of gelatin with polyenes modulates antifungal activity and biocompatibility of electrospun fiber mats

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Lakshminarayanan R

2014-05-01

Full Text Available Rajamani Lakshminarayanan,1,2 Radhakrishnan Sridhar,3,4 Xian Jun Loh,5 Muruganantham Nandhakumar,1 Veluchamy Amutha Barathi,1,6 Madhaiyan Kalaipriya,3,4 Jia Lin Kwan,1 Shou Ping Liu,1,2 Roger Wilmer Beuerman,1,2 Seeram Ramakrishna3,4,7 1Singapore Eye Research Institute, 2Signature Research Program in Neuroscience and Behavioral Disorders, Duke-NUS Graduate Medical School, 3Department of Mechanical Engineering, National University of Singapore, 4Center for Nanofibers and Nanotechnology, National University of Singapore, 5Institute of Materials Research and Engineering, A*STAR (Agency for Science, Technology and Research, 3 Research Link, Singapore, 6Department of Ophthalmology, Yong Loo Lin School of Medicine, National University of Singapore, 7NUS Nanoscience and Nanotechnology Initiative, Singapore Abstract: 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

Mating-Type Genes and MAT Switching in Saccharomyces cerevisiae

Science.gov (United States)

Haber, James E.

2012-01-01

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

Science.gov (United States)

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.
Biodiversity of the microbial mat of the Garga hot spring.

Science.gov (United States)

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

2017-12-28

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

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Marc Torrent

Full Text Available Antimicrobial proteins and peptides (AMPs are important effectors of the innate immune system that play a vital role in the prevention of infections. Recent advances have highlighted the similarity between AMPs and amyloid proteins. Using the Eosinophil Cationic Protein as a model, we have rationalized the structure-activity relationships between amyloid aggregation and antimicrobial activity. Our results show how protein aggregation can induce bacteria agglutination and cell death. Using confocal and total internal reflection fluorescence microscopy we have tracked the formation in situ of protein amyloid-like aggregates at the bacteria surface and on membrane models. In both cases, fibrillar aggregates able to bind to amyloid diagnostic dyes were detected. Additionally, a single point mutation (Ile13 to Ala can suppress the protein amyloid behavior, abolishing the agglutinating activity and impairing the antimicrobial action. The mutant is also defective in triggering both leakage and lipid vesicle aggregation. We conclude that ECP aggregation at the bacterial surface is essential for its cytotoxicity. Hence, we propose here a new prospective biological function for amyloid-like aggregates with potential biological relevance.
Evaluation of two automated chemiluminescence immunoassays, the LIAISON Treponema Screen and the ARCHITECT Syphilis TP, and the Treponema pallidum particle agglutination test for laboratory diagnosis of syphilis.

Science.gov (United States)

Wellinghausen, Nele; Dietenberger, Hanna

2011-08-01

Automated Treponema pallidum-specific chemi-luminescence immunoassays (CLIA) run on random-access analyzers allow for rapid diagnosis of syphilis infection. We evaluated the LIAISON Treponema Screen (LIA) and the ARCHITECT Syphilis TP (ARCH) in comparison to the Treponema pallidum particle agglutination (TPPA) test, as a screening test for syphilis. We performed a prospective study using 577 sera submitted for diagnosis of syphilis, including 318 samples from pregnant women. In addition, 42 stored sera from 32 patients with clinically and serologically characterized syphilis infection were investigated. In the prospective study, the sensitivity and specificity of LIA, ARCH, and TPPA were 100% (18/18), 100% (17/17), and 100% (18/18), and 100% (558/558), 99.8% (552/553), and 99.6% (556/558), respectively. In pregnant women, the specificity of LIA and ARCH was 100% (317/317) and of TPPA 99.7% (316/317). One sample from a child with assumed exposure to maternal antitreponemal antibodies was omitted from analysis. LIA, ARCH, and TPPA were also positive in all investigated sera from patients with known syphilis. Both automated CLIA demonstrated excellent diagnostic sensitivity and specificity when evaluated as a screening test for syphilis under routine conditions of a diagnostic laboratory. Thus, these may be used independently as an alternative to the manual TPPA screen.
Flow of light energy in benthic photosynthetic microbial mats

Energy Technology Data Exchange (ETDEWEB)

Al-Najjar, Mohammad Ahmad A.

2010-12-15

The work in this thesis demonstrates the assessment of the energy budget inside microbial mat ecosystems, and the factors affecting light utilization efficiency. It presents the first balanced light energy budget for benthic microbial mat ecosystems, and shows how the budget and the spatial distribution of the local photosynthetic efficiencies within the euphotic zone depend on the absorbed irradiance (Jabs). The energy budget was dominated by heat dissipation on the expense of photosynthesis. The maximum efficiency of photosynthesis was at light limiting conditions When comparing three different marine benthic photosynthetic ecosystems (originated from Abu-Dhabi, Arctic, and Exmouth Gulf in Western Australia), differences in the efficiencies were calculated. The results demonstrated that the maximum efficiency depended on mat characteristics affecting light absorption and scattering; such as, photopigments ratio and distribution, and the structural organization of the photosynthetic organisms relative to other absorbing components of the ecosystem (i.e., EPS, mineral particles, detritus, etc.). The maximum efficiency decreased with increasing light penetration depth, and increased with increasing the accessory pigments (phycocyanin and fucoxanthin)/chlorophyll ratio. Spatial heterogeneity in photosynthetic efficiency, pigment distribution, as well as light acclimation in microbial mats originating from different geographical locations was investigated. We used a combined pigment imaging approach (variable chlorophyll fluorescence and hyperspectral imaging), and fingerprinting approach. For each mat, the photosynthetic activity was proportional to the local pigment concentration in the photic zone, but not for the deeper layers and between different mats. In each mat, yield of PSII and E1/2 (light acclimation) generally decreased in parallel with depth, but the gradients in both parameters varied greatly between samples. This mismatch between pigments concentration
Enhancing the mechanical properties of electrospun polyester mats by heat treatment

Directory of Open Access Journals (Sweden)

M. Kancheva

2015-01-01

Full Text Available Microfibrous materials with a targeted design based on poly(L-lactic acid (PLA and poly(ε-caprolactone (PCL were prepared by electrospinning and by combining electrospinning and electrospraying. Several approaches were used: (i electrospinning of a common solution of the two polymers, (ii simultaneous electrospinning of two separate solutions of PLA and PCL, (iii electrospinning of PLA solution in conjunction with electrospraying of PCL solution, and (iv alternating layer-by-layer deposition by electrospinning of separate PLA and PCL solutions. The mats were heated at the melting temperature of PCL (60°", thus achieving melting of PCL fibers/particles and thermal sealing of the fibers. The mats subjected to thermal treatment were characterized by greater mean fiber diameters and reduced values of the water contact angle compared to the pristine mats. Heat treatment of the mats affected their thermal stability and led to an increase in the crystallinity degree of PLA incorporated in the mats, whereas that of PCL was reduced. All mats were characterized by enhanced mechanical properties after thermal treatment as compared to the non-treated fibrous materials.
Polyelectrolyte-Functionalized Nanofiber Mats Control the Collection and Inactivation of Escherichia coli

Directory of Open Access Journals (Sweden)

Katrina A. Rieger

2016-04-01

Full Text Available 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.
Polyelectrolyte-Functionalized Nanofiber Mats Control the Collection and Inactivation of Escherichia coli

Science.gov (United States)

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

2016-01-01

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

Science.gov (United States)

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

Science.gov (United States)

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 (pgeographically linked co-sampling of humans and animals to establish the main sources of leptospirosis in the region. PMID:25629781
Synthesis of CuAlO2 nanofibrous mats by electrospinning

International Nuclear Information System (INIS)

Zhao Shizhen; Li Miaoyu; Liu Xiaomin; Han Gaoyi

2009-01-01

Electrospinning as a versatile method for preparation of nanofibers has been used to fabricate the polyvinylalcohol nanofibers containing equal molar of aluminum nitrate and copper acetate. After pretreated at 400 deg. C, the composite fibrous mats were annealed at 1100 deg. C in air for 5 h and then the delafossite-structured p-type CuAlO 2 ceramics fibrous mats were obtained. The obtained CuAlO 2 ceramics fibrous mats were characterized by scanning electrical microscope, X-ray diffraction and diffuse reflectance spectroscopy. The direct energy gap of the prepared CuAlO 2 ceramics fibrous mats was measured to be about 3.38 eV. The CuAlO 2 behaved like semiconductors and the thermally activated energy was about 0.25 eV.
Reactive Capping Mat Development and Evaluation for Sequestering Contaminants in Sediments

Science.gov (United States)

2011-08-01

82 Figure 5.3-30. Biogas bubble flow/dissipation at Day 0 (left) and Day 12 (right) of the gas permeability test...were carried out at different loading rates of the select contaminants with both bare amendment and amendment preloaded with humic acid to obtain ...0.28 lb/ft2 activated carbon, 0.23 lb/ft2 apatite, 0.28 lb/ft2 organoclay) obtained from the small-scale test mat recovered from Cottonwood Bay
Latex agglutination test

Science.gov (United States)

... Updated by: Frank A. Greco, MD, PhD, Director, Biophysical Laboratory, Edith Nourse Rogers Memorial Hospital, Bedford, MA. ... any medical emergency or for the diagnosis or treatment of any medical condition. A licensed physician should ...
Mobile Application Testing in Pakistan: A Survey

Directory of Open Access Journals (Sweden)

Muhammad Saqib

2017-12-01

Full Text Available Research regarding MAT (Mobile Application Testing in Pakistan is hard to discover and to the best of our knowledge, no work has been done in surveying MAT in Pakistan. In this work, we have examined the current trend and status of MAT in Pakistan. Main objective was to investigate to what extent MAT is currently applied in Pakistan software companies and what experience the companies have with using MAT. Furthermore, efforts were made to find out what testers think about MAT, e.g. issue, advantages and disadvantages of MAT, what factors affects MAT and how they plan to improve MAT. In order to achieve our objectives, we used a comprehensive online survey so we converted our research questions into correspondence survey questions. We served a questionnaire of the survey to 66 testing relevant officials of leading software companies in different cities of Pakistan to develop a model study about general trend and status of MAT which can be generalized all over Pakistan. We received 56 replies in total after over 2 months. After that, we used SPSS tool to analyze the replies of this questionnaire. Cross-Tabulation Analysis and Pearson Chi-square tests have been computed to examine the results. We found some interesting results on current status and practice of MAT in Pakistan software companies.
Flakeboard thickness swelling. Part I, Stress relaxation in a flakeboard mat

Science.gov (United States)

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...
Características físicas de dietas para peixes confeccionadas com diferentes aglutinantes Influence of agglutinants on physical stability of fish diets

Directory of Open Access Journals (Sweden)

Margarida Maria Barros

2002-04-01

Full Text Available Este experimento teve por objetivo avaliar a eficiência de diferentes aglutinantes, a seco e na água, por meio da estabilidade física do pélete. Foram avaliadas duas técnicas de processamento (com ou sem vapor e seis aglutinantes (carboximetilcelulose, polimetilcarbamida, amido de mandioca, alginato de sódio, polivinilpirrolidona, goma guar, através da análise de variância no esquema fatorial (2x6, além de um controle, ao qual não foi acrescido aglutinante. Concluiu-se que o aglutinante melhora significativamente a resistência física do grânulo, independente da técnica de processamento; que o vapor determina grânulos mais estáveis quando em contato com a água e, que o alginato de sódio proporciona grânulos fisicamente mais estáveis, em ambas as técnicas de processamento, enquanto a goma guar a pior.The aim of this paper was to determine the influence of different dry and water agglutinants, through physical stability of pellets. The agglutinants were sodium alginate, guar gum, polymetylcarbamide, polyvinylpirrolidone, carboxymetilcellulose, and cassava starch. The manufacturing processes were two: with and without steam and extrusion. These treatments were evaluated through the variance analysis technique with the factorial scheme 2 x 6 (two processes and six agglutinants, and one control where no extra agglutinants was added. Results showed that, independently of processing technique, the presence the agglutinants improves the physical resistance of the pellets significantly, giving the whole pellets more stability while in contact with water, and that the sodium alginate gives pellets the highest aggregated characteristic, in both processes, while that guar gum gives the lowest.
Sequester of metals and mineralization of organic contaminants with microbial mats

International Nuclear Information System (INIS)

Bender, J.; Phillips, P.; Gould, J.P.

1995-01-01

Several recalcitrant organic contaminants are completely mineralized to simple products by microbial mats. Contaminants include chlordane, PCB, TNT, petroleum distillates, BM compounds and TCE in a mixed contaminant solution containing Zn. Degradation rates are relatively rapid under both dark and light conditions. In addition to complete degradation of organic materials, mats have been used to reduce selenate to elemental selenium, remove Pb, Cd, Cu, Zn, Co, Cr, Fe and Mn from water and sequester uranium (U 238 ) at a rate of 3.19 mg/m 2 /h. Results of three pilot projects, including field pond treatment of mine drainage and bioreactor treatment of BTEX compounds will be reported. Microbial mats are natural heterotrophic and autotrophic communities dominated by cyanobacteria (blue-green algae). They are self-organized laminated structures annealed fightly together by slimy secretions from various microbial components. The surface slime of the mats effectively immobilizes the ecosystem to a variety of substrates, thereby stabilizing the most efficient internal microbial structure. Cyanobacteria mats are generated for bioremediation applications by enriching a water surface with ensiled grass clippings together with mat inocula developed in the laboratory
Ricinus communis agglutinin-mediated agglutination and fusion of glycolipid-containing phospholipid vesicles: effect of carbohydrate head group size, calcium ions, and spermine.

Science.gov (United States)

Hoekstra, D; Düzgüneş, N

1986-03-25

The glycolipids galactosylcerebroside (GalCer), lactosylceramide (LacCer), and trihexosylceramide (Gb3) were inserted into phospholipid vesicles, consisting of phosphatidylethanolamine and phosphatidic acid. The extent to which their carbohydrate head groups protruded beyond the vesicle surface and their interference with membrane approach were examined by determining vesicle susceptibility toward type I Ricinus communis agglutinin (RCA1) induced agglutination and Ca2+- and spermine-induced aggregation and fusion either in the presence or in the absence of the lectin. The initial agglutination rates increased in the order GalCer much less than LacCer less than Gb3, while a reversed order was obtained for Ca2+- and spermine-induced aggregation and fusion, indicating an enhanced steric interference on close approach of bilayers with increasing head group size. The lectin-mediated agglutination rates for LacCer- and Gb3-containing vesicles increased by an order of magnitude when Ca2+ was also included in the medium, at a concentration that did not induce aggregation per se. Charge neutralization could not account for this observation as the polyvalent cation spermine did not display this synergistic effect with RCA1. Addition of Ca2+ to preagglutinated vesicles substantially reduced the threshold cation concentration for fusion (micromolar vs. millimolar). Quantitatively, this concentration decreased with decreasing carbohydrate head group size, indicating that the head group protrusion determined the interbilayer distance within the vesicle aggregate. The distinct behavior of Ca2+ vs. spermine on RCA1-induced agglutination on the one hand and fusion on the other indicated that Ca2+ regulates the steric orientation of the carbohydrate head group, which appears to be related to its ability to dehydrate the bilayer. As a result, lectin agglutinability becomes enhanced while fusion will be interrupted as the interbilayer distance increases, the threshold head group size
Electrospun polyvinylpyrrolidone (PVP)/green tea extract composite nanofiber mats and their antioxidant activities

Science.gov (United States)

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.

MICROBIAL MATS - A JOINT VENTURE

NARCIS (Netherlands)

VANGEMERDEN, H

Microbial mats characteristically are dominated by a few functional groups of microbes: cyanobacteria, colorless sulfur bacteria, purple sulfur bacteria, and sulfate-reducing bacteria. Their combined metabolic activities result in steep environmental microgradients, particularly of oxygen and
Photosynthetic microbial mats today, on early Earth, (and on early Mars?)

Science.gov (United States)

Des Marais, D. J.

2008-05-01

Marine hypersaline cyanobacterial mats offer insights about their ancient ancestors, whose fossil record is 3.43 billion years old. Studies of mat microbiota have greatly expanded the known diversity of ancient microbial lineages. Their evolution was shaped by mat microenvironments, which can differ substantially from their surroundings. Oxygenic photosynthesis perhaps developed in microbial mats and probably triggered a major evolutionary transformation and diversification of the early biosphere. Gross primary production rates in cyanobacterial mats can rival the most productive ecosystems known. Sunlight changes in intensity and spectral composition as it penetrates mats, and counteracting gradients of O2 and sulfide shape the chemical microenvironment. A combination of benefits and hazards of light, O2 and sulfide promotes the allocation of the various essential mat processes between light and dark periods and to various depths in the mat. Close inspection has revealed surprises, for example: anoxygenic phototrophs inside cyanobacterial sheaths, record- high sulfate reduction rates in O2-saturated conditions, and high H2 fluxes into overlying waters. Diverse organic biomarker compounds have been documented that are amenable to long-term preservation. Such coordinated observations of populations, processes and products are making fundamental questions in ecology accessible. Cyanobacterial mats have robust fossil records in part because they populated stable continental platforms and margins, contributing to sediments having high preservation potential. Proterozoic cyanobacterial fossils and organic biomarkers are well documented. The 3.43 Ga Strelley Pool cherts, W. Australia, reveal diverse stromatolites that populated a partially restricted, low-energy shallow hypersaline basin. Molecular studies of extant bacteria hint that early chlorophyll-utilizing photosynthesizers required geochemical sources of reductants. Did these anoxygenic phototrophs once sustain an
Antibacterial electrospun chitosan-polyethylene oxide nanocomposite mats containing ZIF-8 nanoparticles.

Science.gov (United States)

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

2016-10-01

Antimicrobial chitosan-polyethylene oxide (CS-PEO) nanofiber mats loaded with 3, 5 and 10% (w/w) of zeolitic imidazolate framework-8 nanoparticles (ZIF-8 NPs, ∼60nm diameter) were developed by electrospinning technique. The CS-PEO-GA-3% ZIF-8 NPs crosslinked with glutaraldehyde (GA) vapor was also prepared. The electrospun mats were characterized by various analysis including FE-SEM, EDAX, elemental mapping, FT-IR, contact angle, TGA/DSC as well as tensile strength analysis. The nanofibers had average diameters within the range ∼70-120nm. Antimicrobial activities of the CS-PEO and CS-PEO-3% ZIF-8 mats were evaluated by the viable cell-counting method for determining their effectiveness in reducing or halting the growth of Staphylococcus aureus and Escherichia coli bacteria so that the CS-PEO mat containing 3% ZIF-8 revealed 100% bactericidal activity against both kinds of bacteria. The crosslinked CS-PEO-GA-3% ZIF-8 NPs sample was less thermally stable but more hydrophilic than its related non-crosslinked mat reflecting there was no need to crosslink the fibers using a chemical crosslinker having adverse effects. The highest hydrophobicity and appropriate thermal and tensile properties of CS-PEO-3% ZIF-8 NPs among those of the mats including 5 and 10% ZIF-8 NPs suggested that the mentioned mat is the most suitable sample for food coating applications. Copyright © 2016 Elsevier B.V. All rights reserved.
Bactericidal antibody against a representative epidemiological meningococcal serogroup B panel confirms that MATS underestimates 4CMenB vaccine strain coverage.

Science.gov (United States)

Frosi, Giacomo; Biolchi, Alessia; Lo Sapio, Morena; Rigat, Fabio; Gilchrist, Stefanie; Lucidarme, Jay; Findlow, Jamie; Borrow, Ray; Pizza, Mariagrazia; Giuliani, Marzia Monica; Medini, Duccio

2013-10-09

4CMenB (Bexsero), a vaccine developed against invasive meningococcal disease caused by capsular group B strains (MenB), was recently licensed for use by the European Medicines Agency. Assessment of 4CMenB strain coverage in specific epidemiologic settings is of primary importance to predict vaccination impact on the burden of disease. The Meningococcal Antigen Typing System (MATS) was developed to predict 4CMenB strain coverage, using serum bactericidal antibody assay with human complement (hSBA) data from a diverse panel of strains not representative of any specific epidemiology. To experimentally validate the accuracy of MATS-based predictions against strains representative of a specific epidemiologic setting. We used a stratified sampling method to identify a representative sample from all MenB disease isolates collected from England and Wales in 2007-2008, tested the strains in the hSBA assay with pooled sera from infant and adolescent vaccinees, and compared these results with MATS. MATS predictions and hSBA results were significantly associated (P=0.022). MATS predicted coverage of 70% (95% CI, 55-85%) was largely confirmed by 88% killing in the hSBA (95% CI, 72-95%). MATS had 78% accuracy and 96% positive predictive value against hSBA. MATS is a conservative predictor of strain coverage by the 4CMenB vaccine in infants and adolescents. Crown Copyright © 2013. Published by Elsevier Ltd. All rights reserved.
Carbon cycling and calcification in hypersaline microbial mats

OpenAIRE

Ludwig, Rebecca

2004-01-01

Phototrophic microbial mats are laminated aggregations of microorganisms that thrive in extreme and oligotrophic environments. Primary production rates by oxygenic phototrophs are extremely high. Primary producers supply heterotrophic mat members with organic carbon, which in turn regenerate CO2 needed for autotrophic carbon fixation. Another potential source of CO2 is calcification, which is known to shift the carbonate equilibrium towards CO2. This thesis investigated the carbon cycle of mi...
Lab-on-a-disc agglutination assay for protein detection by optomagnetic readout and optical imaging using nano- and micro-sized magnetic beads

DEFF Research Database (Denmark)

Uddin, Rokon; Burger, Robert; Donolato, Marco

2016-01-01

of manual steps involved. The detection of the target protein was achieved in two ways: (1) optomagnetic readout using magnetic nanobeads (MNBs); (2) optical imaging using magnetic microbeads (MMBs). The optomagnetic readout of agglutination is based on optical measurement of the dynamics of MNB aggregates...... whereas the imaging method is based on direct visualization and quantification of the average size of MMB aggregates. By enhancing magnetic particle agglutination via application of strong magnetic field pulses, we obtained identical limits of detection of 25 pM with the same sample-to-answer time (15 min...
An experiment to test advanced materials impacted by intense proton pulses at CERN HiRadMat facility

CERN Document Server

Bertarelli, A; Boccone, V; Carra, F; Cerutti, F; Charitonidis, N; Charrondiere, C; Dallocchio, A; Fernandez Carmona, P; Francon, P; Gentini, L; Guinchard, M; Mariani, N; Masi, A; Marques dos Santos, S D; Moyret, P; Peroni, L; Redaelli, S; Scapin, M

2013-01-01

Predicting the consequences of highly energetic particle beams impacting protection devices as collimators or high power target stations is a fundamental issue in the design of state-of-the-art facilities for high-energy particle physics. These complex dynamic phenomena can be successfully simulated resorting to highly non-linear numerical tools (Hydrocodes). In order to produce accurate results, however, these codes require reliable material constitutive models that, at the extreme conditions induced by a destructive beam impact, are scarce and often inaccurate. In order to derive or validate such models a comprehensive, first-of-its-kind experiment has been recently carried out at CERN HiRadMat facility: performed tests entailed the controlled impact of intense and energetic proton pulses on a number of specimens made of six different materials. Experimental data were acquired relying on embedded instrumentation (strain gauges, temperature probes and vacuum sensors) and on remote-acquisition devices (laser ...
Thermodynamics and phase transformations the selected works of Mats Hillert

CERN Document Server

Lilensten, Jean

2006-01-01

This book is a compendium of Mat Hillert's publications. Mat Hillert is a world specialist in metal alloy at the origin of a universal computing code used to calculate the diagrams of phase. This work is in English.
Poly(L-lactide)/halloysite nanotube electrospun mats as dual-drug delivery systems and their therapeutic efficacy in infected full-thickness burns.

Science.gov (United States)

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.
A Thermal Physiological Comparison of Two HazMat Protective Ensembles With and Without Active Convective Cooling

Science.gov (United States)

Williamson, Rebecca; Carbo, Jorge; Luna, Bernadette; Webbon, Bruce W.

1998-01-01

Wearing impermeable garments for hazardous materials clean up can often present a health and safety problem for the wearer. Even short duration clean up activities can produce heat stress injuries in hazardous materials workers. It was hypothesized that an internal cooling system might increase worker productivity and decrease likelihood of heat stress injuries in typical HazMat operations. Two HazMat protective ensembles were compared during treadmill exercise. The different ensembles were created using two different suits: a Trelleborg VPS suit representative of current HazMat suits and a prototype suit developed by NASA engineers. The two life support systems used were a current technology Interspiro Spirolite breathing apparatus and a liquid air breathing system that also provided convective cooling. Twelve local members of a HazMat team served as test subjects. They were fully instrumented to allow a complete physiological comparison of their thermal responses to the different ensembles. Results showed that cooling from the liquid air system significantly decreased thermal stress. The results of the subjective evaluations of new design features in the prototype suit were also highly favorable. Incorporation of these new design features could lead to significant operational advantages in the future.
Low-Light Anoxygenic Photosynthesis and Fe-S-Biogeochemistry in a Microbial Mat.

Science.gov (United States)

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

2018-01-01

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

International Nuclear Information System (INIS)

Rebout, B.M.; Garcia-Pichel, F.

1995-01-01

Exposure to moderate doses of UV B (0.35 to 0.79 W m -2 s -1 or 0.98 to 2.2 μmol of photons m -2 s -1 at 310 nm) caused the surface layers of microbial mats from Solar Lake, Sinai, Egypt, to become visibly lighter green. Concurrent with the color change were rapid and dramatic reductions in gross photosynthesis and in the resultant high porewater oxygen concentrations in the surface layers of the mats. The depths at which both maximum gross photosynthesis and maximum oxygen concentrations occurred were displaced downward. In contrast, gross photosynthesis in the deeper layers of the mats increased in response to UV B incident upon the surface. The cessation of exposure to UV B partially reversed all of these changes. Taken together, these responses suggest that photoautotrophic members of the mat community, most likely the dominant cyanobacterium Microcoleus chthonoplastes, were migrating in response to the added UV B. The migration phenomenon was also observed in response to increases in visible radiation and UV A, but UV B was ca. 100-fold more effective than visible radiation and ca. 20-fold more effective than UV A in provoking the response. Migrating microorganisms within this mat are apparently able to sense UV B directly and respond behaviorally to limit their exposure to UV. Because of strong vertical gradients of light and dissolved substances in microbial mats, the migration and the resultant vertical redistribution of photosynthetic activity have important consequences for both the photobiology of the cyanobacteria and the net primary productivity of the mat ecosystem
A quantitative PCR (TaqMan assay for pathogenic Leptospira spp

Directory of Open Access Journals (Sweden)

Symonds Meegan L

2002-07-01

Full Text Available Abstract Background Leptospirosis is an emerging infectious disease. The differential diagnosis of leptospirosis is difficult due to the varied and often "flu like" symptoms which may result in a missed or delayed diagnosis. There are over 230 known serovars in the genus Leptospira. Confirmatory serological diagnosis of leptospirosis is usually made using the microscopic agglutination test (MAT which relies on the use of live cultures as the source of antigen, often performed using a panel of antigens representative of local serovars. Other techniques, such as the enzyme linked immunosorbent assay (ELISA and slide agglutination test (SAT, can detect different classes of antibody but may be subject to false positive reactions and require confirmation of these results by the MAT. Methods The polymerase chain reaction (PCR has been used to detect a large number of microorganisms, including those of clinical significance. The sensitivity of PCR often precludes the need for isolation and culture, thus making it ideal for the rapid detection of organisms involved in acute infections. We employed real-time (quantitative PCR using TaqMan chemistry to detect leptospires in clinical and environmental samples. Results and Conclusions The PCR assay can be applied to either blood or urine samples and does not rely on the isolation and culture of the organism. Capability exists for automation and high throughput testing in a clinical laboratory. It is specific for Leptospira and may discriminate pathogenic and non-pathogenic species. The limit of detection is as low as two cells.
Human leptospirosis in Tanzania: sequencing and phylogenetic analysis confirm that pathogenic Leptospira species circulate among agro-pastoralists living in Katavi-Rukwa ecosystem.

Science.gov (United States)

Muller, Shabani K; Assenga, Justine A; Matemba, Lucas E; Misinzo, Gerald; Kazwala, Rudovick R

2016-06-10

Leptospirosis is a neglected zoonotic disease of worldwide public health importance. The disease affects humans, domestic animals and wildlife. However, leptospirosis is challenging in its diagnosis in humans. Culture technique, which is time consuming, is not recommended for clinical diagnosis. For these reasons, serological and molecular techniques remain the test of choice. The major objective of this study was to explore the genetic characteristic of Leptospira species which are prevalent among agro-pastoralists living in Katavi-Rukwa Ecosystem, Tanzania. A cross-sectional epidemiological study was carried out in the Katavi-Region South-west, Tanzania between August, 2013 and November, 2014. A total of 267 participants were randomly recruited for the study. Microscopic agglutination test (MAT) was used to detect antibody against six Leptospira antigens including local serogroups Icterohaemorrhagiae, Ballum, Grippotyphosa, Sejroe and reference serogroups Hebdomadis, and Australis. Samples with MAT titers ≥ 1:160 were scored as positive, samples with MAT titers ranging from 1:20 to 1:80 were scored as exposed to Leptospira, and absence of agglutination titers was scored as negative. All MAT positive samples, including the low titre samples were subjected to PCR using the respective 16S rRNA primers for the pathogenic and non-pathogenic species. Out of 267 samples tested, 80 (29.9 %) were positive with MAT. The major circulating leptospiral serogroups were Sejroe (15.7 %,), Icterohaemorrhagiae (8.9 %), Grippotyphosa (4.8 %), Hebdomadis (3.37 %), Australis (1.49 %) and Ballum (1.19 %). By using PCR, 33 (15.7 %) out of 210 samples were pathogenic Leptospira while no saprophytic Leptospira spp. was detected. Partial 16S rRNA gene sequences of Leptospira species which were obtained from this study were submitted to GenBank and acquired accession numbers KP313246 and KP313247. Phylogenetic analysis of the nucleotide sequences revealed that species
Superhydrophobic PVDF and PVDF-HFP nanofibrous mats with antibacterial and anti-biofouling properties

Energy Technology Data Exchange (ETDEWEB)

Spasova, M.; Manolova, N. [Laboratory of Bioactive Polymers, Institute of Polymers, Bulgarian Academy of Sciences, Acad. G. Bonchev St, bl. 103A, BG-1113 Sofia (Bulgaria); Markova, N. [Institute of Microbiology, Bulgarian Academy of Sciences, Acad. G. Bonchev St, bl. 26, BG-1113 Sofia (Bulgaria); Rashkov, I., E-mail: rashkov@polymer.bas.bg [Laboratory of Bioactive Polymers, Institute of Polymers, Bulgarian Academy of Sciences, Acad. G. Bonchev St, bl. 103A, BG-1113 Sofia (Bulgaria)

2016-02-15

Graphical abstract: - Highlights: • New PVDF and PVDF-HFP nanofibers decorated with ZnO nanoparticles and a model drug. • The nanofibrous materials were fabricated by one-pot electrospinning. • The obtained materials are superhybrophobic and possess antibacterial properties. - Abstract: Superhydrophobic nanofibrous materials of poly(vinylidene fluoride) (PVDF) and poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP) were prepared by one-pot electrospinning technique. The mats were decorated with ZnO nanoparticles with silanized surface and a model drug – 5-chloro-8-hydroxyquinolinol (5Cl8HQ). The obtained hybrid nanofibrous materials were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), contact angle measurements, mechanical and microbiological tests. The results showed that the incorporation of ZnO nanoparticles into PVDF and PVDF-HFP nanofibers increased the hydrophobicity (contact angle 152°), improved the thermal stability and imparted to the nanofibrous materials anti-adhesive and antimicrobial properties. The mats containing the model drug possessed antibacterial activity against Escherichia coli and Staphylococcus aureus. The results suggested that the obtained hybrid mats could find potential biomedical applications requiring antibacterial and anti-biofouling properties.
Laboratory evaluation of a simple and rapid latex agglutination assay for the serodiagnosis of typhoid fever

NARCIS (Netherlands)

Abdoel, Theresia H.; Pastoor, Rob; Smits, Henk L.; Hatta, Mochammad

2007-01-01

A latex agglutination assay for the serodiagnosis of typhoid fever was evaluated on samples collected from patients with clinical suspicion of typhoid fever in South Sulawesi, Indonesia, where the disease is endemic. The latex assay is very easy to use, gives a rapid result and may be used as a
Coastal microbial mats: the physiology of a small-scale ecosystem

NARCIS (Netherlands)

Stal, L.J.

2001-01-01

Coastal inter-tidal sandy sediments, salt marshes and mangrove forests often support the development of microbial mats. Microbial mats are complex associations of one or several functional groups of microorganisms and their formation usually starts with the growth of a cyanobacterial population on a
Maximizing the chances of detecting pathogenic leptospires in mammals

DEFF Research Database (Denmark)

Tulsiani, Suhella; Graham, G C; Dohnt, M F

2011-01-01

. In the earlier field investigation, serum, renal tissue and urine were collected from wild mammals, for the detection of pathogenic leptospires by culture, the microscopic agglutination test (MAT), real-time PCR and silver impregnation of smears. Although 27.6% of the rodents investigated were found leptospire....../ml, did not affect the viability or the detection of leptospires in culture, and is therefore unlikely to reduce the chances of isolating leptospires from an animal that has been euthanized with the compound. It appears that collecting multiple samples from each mammal being checked will improve...
Discovery of a leptospirosis cluster amidst a pneumonic plague outbreak in a miners' camp in the Democratic Republic of the Congo.

Science.gov (United States)

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

Directory of Open Access Journals (Sweden)

Sebastian Haas

2018-04-01

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

Low Seroprevalence of Leishmania infantum and Toxoplasma gondii in the Horse Population in Israel.

Science.gov (United States)

Aharonson-Raz, Karin; Baneth, Gad; Lopes, Ana Patrícia; Brancal, Hugo; Schallig, Henk; Cardoso, Luís; Steinman, Amir

2015-12-01

A cross-sectional investigation was done on the seroprevalence of Leishmania infantum and Toxoplasma gondii infection among apparently healthy horses in Israel. This survey included 383 horses distributed in 22 farms throughout Israel during the years 2011-2013. Serum samples were tested for the presence of immunoglobulin G (IgG) antibodies using the direct agglutination test (DAT) specific to Leishmania and by the modified agglutination test (MAT) for the presence of IgG antibodies to T. gondii. Low seroprevalences were detected for both L. infantum and T. gondii in the horse population in Israel; of the 338 horses tested, 6 (1.4%) were found to be seropositive for L. infantum and 11 (2.5%) for T. gondii, with no significant association between seroprevalence and demographic/environmental factors. An ongoing geographical expansion of L. infantum, previously reported in humans and dogs in Israel, was also supported by our results in horses. Here we present evidence of exposure of horses to L. infantum and T. gondii in Israel. Continuous seroprevalence surveillance in horses, such as the one performed in this study, might further elucidate the eco-epidemiology of these two important zoonotic parasites in this country.
An outbreak of leptospirosis among Peruvian military recruits.

Science.gov (United States)

Russell, Kevin L; Montiel Gonzalez, Marco A; Watts, Douglas M; Lagos-Figueroa, Roberto C; Chauca, Gloria; Ore, Marianela; Gonzalez, Jose E; Moron, Cecilia; Tesh, Robert B; Vinetz, Joseph M

2003-07-01

Acute undifferentiated febrile illnesses are common in tropical developing countries but are difficult to diagnose on clinical grounds alone. Leptospirosis is rarely diagnosed, despite evidence that sporadic cases and epidemics continue to occur worldwide. The purpose of this study was to diagnose an outbreak of acute undifferentiated febrile illness among Peruvian military recruits that developed after a training exercise in the high jungle rainforest of Peru. Of 193 military recruits, 78 developed an acute febrile illness with varied manifestations. Of these, 72 were found to have acute leptospirosis by a microscopic agglutination test (MAT). An enzyme-linked immunosorbent assay using Leptospira biflexa antigen was insensitive for the detection of anti-leptospiral IgM antibodies compared with the MAT (20 of 72, 28%). This outbreak of acute undifferentiated febrile illness among Peruvian military recruits was due to leptospirosis. High clinical suspicion, initiation of preventative measures, and performance of appropriate diagnostic testing is warranted in similar settings to identify, treat, and prevent leptospirosis.
Effects of feeding ratio of beet pulp to alfalfa hay or grass hay on ruminal mat characteristics and chewing activity in Holstein dry cows.

Science.gov (United States)

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 rumination time for AH was shorter than that for GH (P content (P 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 ruminal mat was greater for increasing BP content (P ruminal mat PRV on total rumination time resulted in a high positive correlation (r = 0.744; P 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.
Modular Algorithm Testbed Suite (MATS): A Software Framework for Automatic Target Recognition

Science.gov (United States)

2017-01-01

NAVAL SURFACE WARFARE CENTER PANAMA CITY DIVISION PANAMA CITY, FL 32407-7001 TECHNICAL REPORT NSWC PCD TR-2017-004 MODULAR ...31-01-2017 Technical Modular Algorithm Testbed Suite (MATS): A Software Framework for Automatic Target Recognition DR...flexible platform to facilitate the development and testing of ATR algorithms. To that end, NSWC PCD has created the Modular Algorithm Testbed Suite
Evaluation of the Widal tube agglutination test for the diagnosis of typhoid fever among children admitted to a rural hdospital in Tanzania and a comparison with previous studies

Directory of Open Access Journals (Sweden)

Malahiyo Rajabu

2010-06-01

Full Text Available Abstract Background The diagnosis of typhoid fever is confirmed by culture of Salmonella enterica serotype Typhi (S. typhi. However, a more rapid, simpler, and cheaper diagnostic method would be very useful especially in developing countries. The Widal test is widely used in Africa but little information exists about its reliability. Methods We assessed the performance of the Widal tube agglutination test among febrile hospitalized Tanzanian children. We calculated the sensitivity, specificity, positive predictive value (PPV, and negative predictive value (NPV of various anti-TH and -TO titers using culture-confirmed typhoid fever cases as the "true positives" and all other febrile children with blood culture negative for S. typhi as the "true negatives." Results We found that 16 (1% of 1,680 children had culture-proven typhoid fever. A single anti-TH titer of 1:80 and higher was the optimal indicator of typhoid fever. This had a sensitivity of 75%, specificity of 98%, NPV of 100%, but PPV was only 26%. We compared our main findings with those from previous studies. Conclusion Among febrile hospitalized Tanzanian children with a low prevalence of typhoid fever, a Widal titer of ≥ 1:80 performed well in terms of sensitivity, specificity, and NPV. However a test with improved PPV that is similarly easy to apply and cost-efficient is desirable.
Alpha Matting with KL-Divergence Based Sparse Sampling.

Science.gov (United States)

Karacan, Levent; Erdem, Aykut; Erdem, Erkut

2017-06-22

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

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Susanna A. Wood

2017-10-01

Full Text Available The prevalence of benthic proliferations of the anatoxin-producing cyanobacterium Phormidium are increasing in cobble-bed rivers worldwide. Studies to date have shown high spatial and temporal variability in anatoxin concentrations among mats. In this study we determined anatoxin quotas (toxins per cell in field samples and compared these results to the conventionally-used concentrations (assessed per dry weight of mat. Three mats were selected at sites in two rivers and were sampled every 2–3 h for 24–26 h. The samples were lyophilized and ground to a fine homogenous powder. Two aliquots of known weights were analyzed for anatoxin congeners using liquid chromatography-mass spectrometry, or digital droplet PCR with Phormidium-specific anaC primers to measure absolute quantities of gene copies. Anatoxin concentrations in the mats varied 59- and 303-fold in the two rivers over the study periods. A similar pattern was observed among gene copies (53- and 2828-fold. When converted to anatoxin quotas there was markedly less variability (42- and 16-fold, but significantly higher anatoxin quotas were observed in mats from the second river (p < 0.001, Student’s t-test. There were no obvious temporal patterns with high and low anatoxin concentrations or quotas measured at each sampling time and across the study period. These results demonstrate that variability in anatoxin concentrations among mats is primarily due to the abundance of toxic genotypes. No consistent modulation in anatoxin production was observed during the study, although significant differences in anatoxin quotas among rivers suggest that site-specific physiochemical or biological factors may influence anatoxin production.
Electrospinning and stabilization of chitosan nanofiber mats

Science.gov (United States)

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

Energy Technology Data Exchange (ETDEWEB)

Mobberley, Jennifer M.; Lindemann, Stephen R.; Bernstein, Hans C.; Moran, James J.; Renslow, Ryan S.; Babauta, Jerome; Hu, Dehong; Beyenal, Haluk; Nelson, William 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 abundant 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.
Modification of PLGA Nanofibrous Mats by Electron Beam Irradiation for Soft Tissue Regeneration

Directory of Open Access Journals (Sweden)

Jae Baek Lee

2015-01-01

Full Text Available Biodegradable poly(lactide-co-glycolide (PLGA has found widespread use in modern medical practice. However, the degradation rate of PLGA should be adjusted for specific biomedical applications such as tissue engineering, drug delivery, and surgical implantation. This study focused on the effect of electron beam radiation on nanofibrous PLGA mats in terms of physical properties and degradation behavior with cell proliferation. PLGA nanofiber mats were prepared by electrospinning, and electron beam was irradiated at doses of 50, 100, 150, 200, 250, and 300 kGy. PLGA mats showed dimensional integrity after electron beam irradiation without change of fiber diameter. The degradation behavior of a control PLGA nanofiber (0 kGy and electron beam-irradiated PLGA nanofibers was analyzed by measuring the molecular weight, weight loss, change of chemical structure, and fibrous morphology. The molecular weight of the PLGA nanofibers decreased with increasing electron beam radiation dose. The mechanical properties of the PLGA nanofibrous mats were decreased with increasing electron beam irradiation dose. Cell proliferation behavior on all electron beam irradiated PLGA mats was similar to the control PLGA mats. Electron beam irradiation of PLGA nanofibrous mats is a potentially useful approach for modulating the biodegradation rate of tissue-specific nonwoven nanofibrous scaffolds, specifically for soft tissue engineering applications.
The contribution of microbial mats to the arsenic geochemistry of an ancient gold mine

International Nuclear Information System (INIS)

Drewniak, Lukasz; Maryan, Natalia; Lewandowski, Wiktor; Kaczanowski, Szymon; Sklodowska, Aleksandra

2012-01-01

The ancient Zloty Stok (SW Poland) gold mine is such an environment, where different microbial communities, able to utilize inorganic arsenic species As(III) and As(V), are found. The purpose of the present study was to (i) estimate prokaryotic diversity in the microbial mats in bottom sediments of this gold mine, (ii) identify microorganisms that can metabolize arsenic, and (iii) estimate their potential role in the arsenic geochemistry of the mine and in the environment. The oxidation/reduction experiments showed that the microbial mat community may significantly contribute to arsenic contamination in groundwater. The presence of both arsenite oxidizing and dissimilatory arsenate reducing bacteria in the mat was confirmed by the detection of arsenite oxidase and dissimilatory arsenate reductase genes, respectively. This work also demonstrated that microorganisms utilizing other compounds that naturally co-occur with arsenic are present within the microbial mat community and may contribute to the arsenic geochemistry in the environment. - Highlights: ► The microbial mats from this ancient gold mine are highly diverse community. ► As(III) oxidizing and As(V) reducing bacteria are present in the mats. ► As redox transformations are linked to the metabolism of microbial mats bacteria. ► Microbial mats play a crucial role in the As biogeochemical cycle within the mine. - The microbial mats from this ancient gold mine can mediate oxidation/reduction reaction of arsenic and in this way may significantly contribute to arsenic contamination in groundwater.
Characterization and Modification of Electrospun Fiber Mats for Use in Composite Proton Exchange Membranes

Science.gov (United States)

Mannarino, Matthew Marchand

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)
Matérn-based nonstationary cross-covariance models for global processes

KAUST Repository

Jun, Mikyoung

2014-01-01

-covariance models, based on the Matérn covariance model class, that are suitable for describing prominent nonstationary characteristics of the global processes. In particular, we seek nonstationary versions of Matérn covariance models whose smoothness parameters
Mechanical characterization of glass fiber (woven roving/chopped strand mat E-glass fiber) reinforced polyester composites

Science.gov (United States)

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.
Electrospun magnetic nanofibre mats – A new bondable biomaterial using remotely activated magnetic heating

Energy Technology Data Exchange (ETDEWEB)

Zhong, Yi [Department of Materials Engineering, University of British Columbia, Vancouver (Canada); Key Laboratory of Science & Technology of Eco-Textile, Ministry of Education, College of Chemistry, Chemical Engineering and Biotechnology, Donghua University, Shanghai (China); Leung, Victor; Yuqin Wan, Lynn [Department of Materials Engineering, University of British Columbia, Vancouver (Canada); Dutz, Silvio [Institut für Biomedizinische Technik und Informatik, Technische Universität Ilmenau (Germany); Department of Nano Biophotonics, Leibniz Institute of Photonic Technology, Jena (Germany); Ko, Frank K., E-mail: frank.ko@ubc.ca [Department of Materials Engineering, University of British Columbia, Vancouver (Canada); Häfeli, Urs O., E-mail: urs.hafeli@ubc.ca [Faculty of Pharmaceutical Sciences, University of British Columbia, Vancouver (Canada)

2015-04-15

A solvothermal process was adopted to produce hydrophilic magnetite (Fe{sub 3}O{sub 4}) nanoparticles which were subsequently emulsified with a chloroform/methanol (70/30 v/v) solution of poly(caprolactone) (PCL) and then electrospun into a 0.2 mm thick PCL mat. The magnetic heating of the mats at a field amplitude of 25 kA/m and frequency of 400 kHz exhibited promising efficiency for magnetic hyperthermia, with a specific absorption rate of about 40 W/g for the magnetic mat. The produced heat was used to melt the magnetic mat onto the surrounding non-magnetic polymer mat from within, without destroying the nanostructure of the non-magnetic polymer more than 0.5 mm away. Magnetic nanofibre mats might thus be useful for internal heat sealing applications, and potentially also for thermotherapy.
Investigation of needleless electrospun PAN nanofiber mats

Science.gov (United States)

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

2018-04-01

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

Directory of Open Access Journals (Sweden)

Letícia B Rocha

2014-09-01

Full Text Available Enteropathogenic and enterohemorrhagic Escherichia coli (EPEC/EHEC are human intestinal pathogens responsible for diarrhea in both developing and industrialized countries. In research laboratories, EPEC and EHEC are defined on the basis of their pathogenic features; nevertheless, their identification in routine laboratories is expensive and laborious. Therefore, the aim of the present work was to develop a rapid and simple assay for EPEC/EHEC detection. Accordingly, the EPEC/EHEC-secreted proteins EspA and EspB were chosen as target antigens.First, we investigated the ideal conditions for EspA/EspB production/secretion by ELISA in a collection of EPEC/EHEC strains after cultivating bacterial isolates in Dulbecco's modified Eagle's medium (DMEM or DMEM containing 1% tryptone or HEp-2 cells-preconditioned DMEM, employing either anti-EspA/anti-EspB polyclonal or monoclonal antibodies developed and characterized herein. Subsequently, a rapid agglutination latex test (RALT was developed and tested with the same collection of bacterial isolates.EspB was defined as a biomarker and its corresponding monoclonal antibody as the tool for EPEC/EHEC diagnosis; the production of EspB was better in DMEM medium. RALT assay has the sensitivity and specificity required for high-impact diagnosis of neglected diseases in the developing world.RALT assay described herein can be considered an alternative assay for diarrhea diagnosis in low-income countries since it achieved 97% sensitivity, 98% specificity and 97% efficiency.
The heterothallic sugarbeet pathogen Cercospora beticola contains exon fragments of both MAT genes that are homogenized by concerted evolution.

Science.gov (United States)

Bolton, Melvin D; de Jonge, Ronnie; Inderbitzin, Patrik; Liu, Zhaohui; Birla, Keshav; Van de Peer, Yves; Subbarao, Krishna V; Thomma, Bart P H J; Secor, Gary A

2014-01-01

Dothideomycetes is one of the most ecologically diverse and economically important classes of fungi. Sexual reproduction in this group is governed by mating type (MAT) genes at the MAT1 locus. Self-sterile (heterothallic) species contain one of two genes at MAT1 (MAT1-1-1 or MAT1-2-1) and only isolates of opposite mating type are sexually compatible. In contrast, self-fertile (homothallic) species contain both MAT genes at MAT1. Knowledge of the reproductive capacities of plant pathogens are of particular interest because recombining populations tend to be more difficult to manage in agricultural settings. In this study, we sequenced MAT1 in the heterothallic Dothideomycete fungus Cercospora beticola to gain insight into the reproductive capabilities of this important plant pathogen. In addition to the expected MAT gene at MAT1, each isolate contained fragments of both MAT1-1-1 and MAT1-2-1 at ostensibly random loci across the genome. When MAT fragments from each locus were manually assembled, they reconstituted MAT1-1-1 and MAT1-2-1 exons with high identity, suggesting a retroposition event occurred in a homothallic ancestor in which both MAT genes were fused. The genome sequences of related taxa revealed that MAT gene fragment pattern of Cercospora zeae-maydis was analogous to C. beticola. In contrast, the genome of more distantly related Mycosphaerella graminicola did not contain MAT fragments. Although fragments occurred in syntenic regions of the C. beticola and C. zeae-maydis genomes, each MAT fragment was more closely related to the intact MAT gene of the same species. Taken together, these data suggest MAT genes fragmented after divergence of M. graminicola from the remaining taxa, and concerted evolution functioned to homogenize MAT fragments and MAT genes in each species. Published by Elsevier Inc.
Evaluation of chromogenic medium and direct latex agglutination test for detection of group B streptococcus in vaginal specimens from pregnant women in Lebanon and Kuwait.

Science.gov (United States)

Ghaddar, Nahed; Alfouzan, Wadha; Anastasiadis, Elie; Al Jiser, Tamima; Itani, Saad Eddine; Dernaika, Racha; Eid, Toufic; Ghaddar, Ali; Charafeddine, Adib; Dhar, Rita; El Hajj, Hiba

2014-10-01

This study was undertaken to evaluate chromogenic medium and a direct latex agglutination test (DLA) for detection of Group B Streptococcus (GBS) in the vaginal specimens of pregnant women, and to ascertain the prevalence of GBS in this population in Kuwait and Lebanon. Vaginal swabs, collected from women at 35-37 weeks of gestation, were cultured on 5 % sheep blood agar (SBA), colistin nalidixic acid agar (CNA), Strept B Select chromogenic agar (SBS) as well as Lim enrichment broth in 168 cases in Lebanon while only SBA was used for 1391 samples in Kuwait. In addition, vaginal samples from 102 GBS-positive and 20 GBS-negative women near the time of delivery were collected in Kuwait for evaluation of the DLA test. During the study period, the prevalence of GBS colonization was determined to be 20.7 % (288/1391) in Kuwait while 18.4 % (31) of 168 pregnant women in Lebanon had vaginal cultures positive for GBS. By direct plating of vaginal swabs on the three media used, the isolation rates of GBS were 51.6, 64.5 and 77.4 % on SBA, CNA and SBS, respectively, which increased to 90.35, 93.1 and 96.8 %, respectively, following subculture in Lim broth after 18 h of incubation. The sensitivity of the DLA test was found to be dependent on the density of GBS colonization, resulting in 100 % sensitivity and 100 % specificity for heavy (>10(2) c.f.u. per swab) and moderately heavy (50-100 c.f.u. per swab) growth of GBS. However, for vaginal specimens yielding women. The DLA test, in particular, could prove to be a useful tool for immediate detection of GBS in women near delivery so that intrapartum antibiotic prophylaxis can be initiated. © 2014 The Authors.
Toolbox for the Modeling and Analysis of Thermodynamic Systems (T-MATS) Users' Workshop Presentations

Science.gov (United States)

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.

Development and characterization of cefazolin loaded zinc oxide nanoparticles composite gelatin nanofiber mats for postoperative surgical wounds

International Nuclear Information System (INIS)

Rath, Goutam; Hussain, Taqadus; Chauhan, Gaurav; Garg, Tarun; Goyal, Amit Kumar

2016-01-01

Systemic antibiotic therapy in post-operative wound care remain controversial leading to escalation in levels of multi-resistant bacteria with unwanted morbidity and mortality. Recently zinc (Zn) because of multiple biophysiological functions, gain considerable interest for wound care. Based on our current understanding, the present study was designed with an intent to produce improve therapeutic approaches for post-operative wound management using composite multi-functional antibiotic carrier. The study involved the fabrication, characterization and pre-clinical evaluation of cefazolin nanofiber mats loaded with zinc oxide (ZnO) and comparing co-formulated mats with individual component, enable a side by side comparison of the benefits of our intervention. Minimum inhibitory concentration (MIC) of the drug, ZnO nanoparticles (ZnONPs) and drug-ZnONP mixture against Staphylococcus aureus was determined using micro dilution assay. The fabricated nanofibers were then evaluated for in-vitro antimicrobial activity and the mechanism of inhibition was predicted by scanning electron microscopy (SEM). Further these nanofiber mats were evaluated in-vivo for wound healing efficacy in Wistar rats. Study revealed that the average diameter of the nanofibers is around 200–900 nm with high entrapment efficiency and display sustained drug release behavior. The combination of ZnO and cefazolin in 1:1 weight ratio showed higher anti-bacterial activity of 1.9 ± 0.2 μg/ml. Transmission electron microscopy of bacterial cells taken from the zone of inhibition revealed the phenomenon of cell lysis in tested combination related to cell wall disruption. Further composite medicated nanofiber mats showed an accelerated wound healing as compared to plain cefazolin and ZnONP loaded mats. Macroscopical and histological evaluations demonstrated that ZnONP hybrid cefazolin nanofiber showed enhanced cell adhesion, epithelial migration, leading to faster and more efficient collagen synthesis
Perfect simulation and moment properties for the Matérn type III process

DEFF Research Database (Denmark)

Møller, Jesper; Huber, Mark L.; Wolpert, Robert L.

2010-01-01

In a seminal work, Bertil Matérn introduced several types of processes for modeling repulsive point processes. In this paper an algorithm is presented for the perfect simulation of the Matérn III process within a bounded window in , fully accounting for edge effects. A simple upper bound on the m......In a seminal work, Bertil Matérn introduced several types of processes for modeling repulsive point processes. In this paper an algorithm is presented for the perfect simulation of the Matérn III process within a bounded window in , fully accounting for edge effects. A simple upper bound...
Tracing biosignatures from the Recent to the Jurassic in sabkha-associated microbial mats

Science.gov (United States)

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

2017-04-01

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

Science.gov (United States)

Wieland, A; Zopfi, J; Benthien, M; Kühl, M

2005-01-01

In situ microsensor measurements were combined with biogeochemical methods to determine oxygen, sulfur, and carbon cycling in microbial mats growing in a solar saltern (Salin-de-Giraud, France). Sulfate reduction rates closely followed the daily temperature changes and were highest during the day at 25 degrees C and lowest during the night at 11 degrees C, most probably fueled by direct substrate interactions between cyanobacteria and sulfate-reducing bacteria. Sulfate reduction was the major mineralization process during the night and the contribution of aerobic respiration to nighttime DIC production decreased. This decrease of aerobic respiration led to an increasing contribution of sulfide (and iron) oxidation to nighttime O2 consumption. A peak of elemental sulfur in a layer of high sulfate reduction at low sulfide concentration underneath the oxic zone indicated anoxygenic photosynthesis and/or sulfide oxidation by iron, which strongly contributed to sulfide consumption. We found a significant internal carbon cycling in the mat, and sulfate reduction directly supplied DIC for photosynthesis. The mats were characterized by a high iron content of 56 micromol Fe cm(-3), and iron cycling strongly controlled the sulfur cycle in the mat. This included sulfide precipitation resulting in high FeS contents with depth, and reactions of iron oxides with sulfide, especially after sunset, leading to a pronounced gap between oxygen and sulfide gradients and an unusual persistence of a pH peak in the uppermost mat layer until midnight.
Regulation of mat responses by a differentiation MAPK pathway in Saccharomyces cerevisiae.

Directory of Open Access Journals (Sweden)

Sheelarani Karunanithi

Full Text Available Fungal species exhibit diverse behaviors when presented with extracellular challenges. Pathogenic fungi can undergo cell differentiation and biofilm formation in response to fluctuating nutrient levels, and these responses are required for virulence. In the model fungal eukaryote Saccharomyces cerevisiae, nutrient limitation induces filamentous growth and biofilm/mat formation. Both responses require the same signal transduction (MAPK pathway and the same cell adhesion molecule (Flo11 but have been studied under different conditions. We found that filamentous growth and mat formation are aspects of a related response that is regulated by the MAPK pathway. Cells in yeast-form mats differentiated into pseudohyphae in response to nutrient limitation. The MAPK pathway regulated mat expansion (in the plane of the XY-axis and substrate invasion (downward in the plane of the Z-axis, which optimized the mat's response to extracellular nutrient levels. The MAPK pathway also regulated an upward growth pattern (in the plane of the Z-axis in response to nutrient limitation and changes in surface rigidity. Upward growth allowed for another level of mat responsiveness and resembled a type of colonial chemorepulsion. Together our results show that signaling pathways play critical roles in regulating social behaviors in which fungal cells participate. Signaling pathways may regulate similar processes in pathogens, whose highly nuanced responses are required for virulence.
Detection of pathogenic Leptospira from selected environment in Kelantan and Terengganu, Malaysia.

Science.gov (United States)

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

Directory of Open Access Journals (Sweden)

Jackson Z Lee

2014-02-01

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

Science.gov (United States)

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.
Photosynthetic and Behavioral Versatility of the Cyanobacterium Oscillatoria-Boryana in a Sulfide-Rich Microbial Mat

DEFF Research Database (Denmark)

CASTENHOLZ, RW; JØRGENSEN, BB; DAMELIO, E.

1991-01-01

and predominant population which was spread over the mat surface during darkness and on overcast days ( 300 W m-2), O. boryana disappeared almost entirely from the mat surface to a position of about 1 mm below the surface pellicle of the mat. O2, sulfide, and pH microelectrodes inserted into excised mat cores...... photosynthesis of O. boryana occurred. This capability was confirmed for O. boryana by [C-14]-photoincorporation and sulfide-microelectrode experiments. Forced exposure to high irradiance levels (500-700 W m-2) was inhibitory to oxygenic photosynthesis in O. boryana, but these intensities impinging on mats...
Temperature dependent transport and dielectric properties of cadmium titanate nanofiber mats

Directory of Open Access Journals (Sweden)

Z. Imran

2013-03-01

Full Text Available We investigate electrical and dielectric properties of cadmium titanate (CdTiO3 nanofiber mats prepared by electrospinning. The nanofibers were polycrystalline having diameter ∼50 nm-200 nm, average length ∼100 μm and crystallite size ∼25 nm. Alternating current impedance measurements were carried out from 318 K – 498 K. The frequency of ac signal was varied from 2 – 105 Hz. The complex impedance plots revealed two depressed semicircular arcs indicating the bulk and interface contribution to overall electrical behavior of nanofiber mats. The bulk resistance was found to increase with decrease in temperature exhibiting typical semiconductor like behavior. The modulus analysis shows the non-Debye type conductivity relaxation in nanofiber mats. The ac conductivity spectrum obeyed the Jonscher power law. Analysis of frequency dependent ac conductivity revealed presence of the correlated barrier hopping (CBH in nanofiber mats over the entire temperature range.
A niche for cyanobacteria producing chlorophyll f within a microbial mat.

Science.gov (United States)

Ohkubo, Satoshi; Miyashita, Hideaki

2017-10-01

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

Science.gov (United States)

Hanci, Hayrunisa; Igan, Hakan; Uyanik, Muhammet Hamidullah

2017-01-01

Many serological tests have been used for the diagnosis of human brucellosis. A new serological method is identified as Brucella Coombs gel test based on the principle of centrifugation gel system similar to the gel system used in blood group determination. In this system, if Brucella antibodies were present in the serum, antigen and antibody would remain as a pink complex on the gel. Otherwise, the pink Brucella antigens would precipitate at the bottom of the gel card system. In this study, we aimed to compare the Brucella Coombs gel test, a new, rapid screen and titration method for detection of non-agglutinating IgG with the Brucella Coombs test. For this study, a total of 88 serum samples were obtained from 45 healthy persons and 43 individuals who had clinical signs and symptoms of brucellosis. For each specimen, Rose Bengal test, standard agglutination test, Coombs test and Brucella Coombs gel test were carried out. Sensitivity and specificity of Brucella Coombs gel test were found as 100.0 and 82.2%, respectively. Brucella Coombs gel test can be used as a screening test with high sensitivity. By the help of pink Brucella antigen precipitation, the tests' evaluation is simple and objective. In addition, determination of Brucella antibody by rapid titration offers another important advantage.
Sway Area and Velocity Correlated With MobileMat Balance Error Scoring System (BESS) Scores.

Science.gov (United States)

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.
Seroprevalence of brucellosis among cattle slaughtered in three municipal abattoirs of Gombe state, Northeastern Nigeria

Directory of Open Access Journals (Sweden)

Saleh Mohammed Jajere

2016-10-01

Full Text Available Aim: A cross-sectional study was conducted to determine the seroprevalence of bovine brucellosis among cattle slaughtered at three municipal abattoirs of Gombe State, Nigeria. Materials and Methods: A total of 200 blood samples collected from slaughtered cattle of different breeds (Sokoto Gudali - 50, White Fulani - 102, Red bororo – 34, and Crossbreeds - 14, sex (males - 19 and females - 181, and from different locations (Billiri - 30, Yamaltu Deba – 50, and Gombe - 120 were screened for brucellosis using rose bengal plate test (RBPT, serum agglutination test (SAT, and microtiter agglutination test (MAT. Results: Of the 200 serum samples analyzed, 7 (3.5%, 10 (5.0% and 18 (9.0% were positive by RBPT, SAT and MAT, respectively. The results showed no statistically significant association between sex and seropositivity to bovine brucellosis. However, seropositivity of bovine brucellosis was higher in females than in males. Similarly, no statistically significant association was observed between breed and occurrence of bovine brucellosis. Moreover, the prevalence of brucellosis was higher in Sokoto Gudali as compared with the other breeds. Based on the study locations, higher seroprevalence was observed in animals screened from Billiri as compared with those from other locations (p<0.05. Conclusion: The presence of Brucella abortus antigen in the sera of slaughtered cattle in Gombe state poses a significant public health risk. Therefore, it is important to carry out further epidemiological studies on fulani herdsmen and cattle herds in the study area, in order to explore the risk factors associated with the occurrence and perpetuation of brucellosis among cattle herds, ascertain the prevalence and status of the disease among both farms and nomadic herds.
Cantera Integration with the Toolbox for Modeling and Analysis of Thermodynamic Systems (T-MATS)

Science.gov (United States)

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.
Aspects of the ecology of mat-forming lichens

Directory of Open Access Journals (Sweden)

P. D. Crittenden

2000-03-01

Full Text Available Lichen species in the genera Cladonia (subgenus Cladina, Cetraria, Stereocaulon and Alectoria are important vegetation components on well-drained terrain and on elevated micro-sites in peatlands in boreal-Arctic regions. These lichens often form closed mats, the component thalli in which grow vertically upwards at the apices and die off in the older basal regions; they are therefore only loosely attached to the underlying soil. This growth habit is relatively unusual in lichens being found in <0.5% of known species. It might facilitate internal nutrienr recycling and higher growth rates and, together with the production of allelochemicals, it might underlie the considerable ecological success of mat-forming lichens; experiments to critically assess the importance of these processes are required. Mat-forming lichens can constitute in excess of 60% of the winter food intake of caribou and reindeer. Accordingly there is a pressing need for data on lichen growth rates, measured as mass increment, in order to help determine the carrying capacity of winter ranges for rhese herbivores and to better predict recovery rates following grazing. Trampling during the snow-free season fragments lichen thalli; mat-forming lichens regenerate very successfully from thallus fragments provided trampling does nor re-occur. Frequent recurrence of trampling creates disturbed habitats from which lichens will rapidly become eliminated consistent with J.P. Grime's CSR strategy theory. Such damage to lichen ground cover has occurred where reindeer or caribou are unable to migrate away from their winter range such as on small islands or where political boundaries have been fenced; it can also occur on summer range that contains a significant lichen component and on winter range where numbers of migrarory animals become excessive. Species of Stereocaulon, and other genera that contain cyanobacteria (most notably Peltigera and Nephroma, are among the principal agents of
Foraminiferans as food for Cephalaspideans (Gastropoda: Opisthobranchia), with notes on secondary tests around calcareous foraminiferans

DEFF Research Database (Denmark)

Cedhagen, Tomas

1996-01-01

species, Ammonia batavus and two agglutinating species, Ammoscalaria pseudospiralis and Ammotium cassis. The test (shell) material of the latter two species was sand grains (quartz). It was inferred that the gastropods avoid agglutinating foraminiferans as food. Many calcareous but not agglutinating......The food of four species of Cephalaspidea (Philine aperta, Philine denticulata, Philine scabra and Cylichna cylindracea) was studied in animals collected on silty clay bottoms at 20-35 m depth on the west coast of Sweden. The specimens were dissected. Only calcareous foraminiferans were found...... foraminiferans surround themselves with a “secondary test”, a cyst or covering of foreign particles around the test. This structure has earlier been called a “reproductive cyst” or “feeding cyst” in some species. “Secondary tests” are primarily connected with feeding, but might also be a preadaptation for other...
Electrospun chitosan-based nanocomposite mats reinforced with chitin nanocrystals for wound dressing

CSIR Research Space (South Africa)

Naseria, N

2014-08-01

Full Text Available The aim of this study was to develop electrospun chitosan/polyethylene oxide-based randomly oriented fiber mats reinforced with chitin nanocrystals (ChNC) for wound dressing. Microscopy studies showedporous mats of smooth and beadless fibers...
Testing of Some Canine Blood Types in Transfusion Compatibility Assessment

Directory of Open Access Journals (Sweden)

L Ognean

2014-01-01

Full Text Available Blood types were determined using SHIGETA (n=136 and DEA1.1 (n=25 kits, in two groups of dogs, consisting of patients that underwent blood transfusions and healthy donors. The tests were conducted in accordance with the procedures established by the manufacturers, using specific monoclonal antibodies kits, heparinized blood for the tube agglutination (TUBE and slide (SLIDE methods, and EDTA treated blood for the CARD and chromatographic (CHROM methods. The clear expression of tube agglutination reaction in the SHIGETA kit provided a good detection of antigens. Positive reactions with anti-DEA1.1 were clear and evident with the CHROM test. SHIGETA tests revealed a predominance 1.1B (47.05% of blood type, common in Rotweilers (81.81% and Romanian Shepherds (73.68% and group 1(-B (24.26%, frequently found in German Shepherds (54.16%, these also representing an important source of compatible blood. DEA1.1 type test, revealed a high frequency of positive dogs (75%, associated with lower number of potential donors. Extrapolation of SHIGETA groups into the DEA system, confirmed the 1(-B positive dogs as DEA 1.1 negative, and their prevalence in German Shepherds also confirmed their known tendency to be “ideal donors”. The CHROME test showed a good efficiency in auto agglutination control and detecting DEA1.1 positive dogs, including patients with severe forms of anemia.
Microbial Mats on the Orkney Islands Revisited: Microenvironment and Microbial Community Composition

DEFF Research Database (Denmark)

Wieland, A.; Kühl, M.; McGowan, L.

2003-01-01

of these sediments. High amounts of algal lipids and slightly higher numbers (genera, abundances) of cyanobacteria were found in Waulkmill Bay mats. However, overall only a few genera and low numbers of unicellular and filamentous cyanobacteria were present in mats from Waulkmill and Swanbister beach, as deduced...... fragment length polymorphism) analysis in Swanbister beach mats, the depth distribution of different populations of purple and sulfate-reducing bacteria could be related to the microenvironmental conditions. Oxygen, but also sulfide and other (inorganic and organic) sulfur compounds, seems to play...

Sensitivity, specificity and predictive probability values of serum agglutination test titres for the diagnosis of Salmonella Dublin culture-positive bovine abortion and stillbirth.

Science.gov (United States)

Sánchez-Miguel, C; Crilly, J; Grant, J; Mee, J F

2018-06-01

The objective of this study was to determine the diagnostic value of maternal serology for the diagnosis of Salmonella Dublin bovine abortion and stillbirth. A retrospective, unmatched, case-control study was carried out using twenty year's data (1989-2009) from bovine foetal submissions to an Irish government veterinary laboratory. Cases (n = 214) were defined as submissions with a S. Dublin culture-positive foetus from a S. Dublin unvaccinated dam where results of maternal S. Dublin serology were available. Controls (n = 415) were defined as submissions where an alternative diagnosis other than S. Dublin was made in a foetus from an S. Dublin unvaccinated dam where the results of maternal S. Dublin serology were available. A logistic regression model was fitted to the data: the dichotomous dependent variable was the S. Dublin foetal culture result, and the independent variables were the maternal serum agglutination test (SAT) titre results. Salmonella serology correctly classified 87% of S. Dublin culture-positive foetuses at a predicted probability threshold of 0.44 (cut-off at which sensitivity and specificity are at a maximum, J = 0.67). The sensitivity of the SAT at the same threshold was 73.8% (95% CI: 67.4%-79.5%), and the specificity was 93.2% (95% CI: 90.3%-95.4%). The positive and negative predictive values were 84.9% (95% CI: 79.3%-88.6%) and 87.3% (95% CI: 83.5%-91.3%), respectively. This study illustrates that the use of predicted probability values, rather than the traditional arbitrary breakpoints of negative, inconclusive and positive, increases the diagnostic value of the maternal SAT. Veterinary laboratory diagnosticians and veterinary practitioners can recover from the test results, information previously categorized, particularly from those results declared to be inconclusive. © 2017 Blackwell Verlag GmbH.
Evaluation of efficacy of some serological tests used for diagnosis of ...

African Journals Online (AJOL)

These samples were subjected to the different serological tests including Rose Bengal plate antigen test, Tube Agglutination test, Rivanol test, Indirect Enzyme Linked Immunosorbent Assay and Competitive Enzyme Linked Immunosorbent Assay. Statistical analysis of the obtained results in different cattle groups was ...
Determination of 210Po in tea, mat and their infusions and its annual intake by Syrians

International Nuclear Information System (INIS)

Al-Masri, M.S.; Nashawati, A.; Amin, Y.; Al-Akel, B.

2004-01-01

Polonium-210 was determined in 34 kinds of imported tea and 9 kinds of mat collected from the Syrian local market. The 210 Po concentration was found to vary from 5.5 to 39 Bq x kg -1 and 47 to 82 Bq x kg -1 in tea and mat samples, respectively. In addition 210 Po was also determined in tea and mat infusions where different infusion conditions have been examined: amount, temperature and infusion time. The results have shown that the amount of 210 Po transferred from tea and mat leaves to the aqueous extract ranged from 9 to 21% and 3 to 15%, respectively. The annual intake of 210 Po by Syrians due to tea consumption and mat infusions was calculated and found to be 9 Bq and 151 Bq for tea and mat respectively: washing of mat with warm water is recommended before preparation the infusions to decrease the annual intake of 210 Po. (author)
Methylmercury enters an aquatic food web through acidophilic microbial mats in Yellowstone National Park, Wyoming.

Science.gov (United States)

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.
Rigid Polyurethane Foam Thermal Insulation Protected with Mineral Intumescent Mat

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Kirpluks Mikelis

2014-12-01

Full Text Available One of the biggest disadvantages of rigid polyurethane (PU foams is its low thermal resistance, high flammability and high smoke production. Greatest advantage of this thermal insulation material is its low thermal conductivity (λ, which at 18-28 mW/(m•K is superior to other materials. To lower the flammability of PU foams, different flame retardants (FR are used. Usually, industrially viable are halogenated liquid FRs but recent trends in EU regulations show that they are not desirable any more. Main concern is toxicity of smoke and health hazard form volatiles in PU foam materials. Development of intumescent passive fire protection for foam materials would answer problems with flammability without using halogenated FRs. It is possible to add expandable graphite (EG into PU foam structure but this increases the thermal conductivity greatly. Thus, the main advantage of PU foam is lost. To decrease the flammability of PU foams, three different contents 3%; 9% and 15% of EG were added to PU foam formulation. Sample with 15% of EG increased λ of PU foam from 24.0 to 30.0 mW/(m•K. This paper describes the study where PU foam developed from renewable resources is protected with thermally expandable intumescent mat from Technical Fibre Products Ltd. (TFP as an alternative to EG added into PU material. TFP produces range of mineral fibre mats with EG that produce passive fire barrier. Two type mats were used to develop sandwich-type PU foams. Also, synergy effect of non-halogenated FR, dimethyl propyl phosphate and EG was studied. Flammability of developed materials was assessed using Cone Calorimeter equipment. Density, thermal conductivity, compression strength and modulus of elasticity were tested for developed PU foams. PU foam morphology was assessed from scanning electron microscopy images.
Enhancement of the in-plane shear properties of carbon fiber composites containing carbon nanotube mats

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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.
Russian Army Mat as a Code System Controlling Behaviour in the Russian army

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Vadim Mikhailin

2004-09-01

Full Text Available This text is to be a shortened, restructured and based on somewhat another factological foundation version of my article “Russkii mat kak muzhskoi obstsennyi kod: problema proiskhozhdeniia i evoliutsiia statusa”, published in # 43 of Novoe Literaturnoe Obozrenie. Tracing the genesis of mat to the specific modes of behaviour, peculiar to the archaic male warrior bands, I’m going to show that the military milieu (and some other, structurally close to it social strata, has always been – and remain – absolutely adequate for the mat speaking. Moreover, mat has always carried on within these strata rather specific function connected with creating of one’s identity as a military, and its use offers various and sometimes the only possible means of impact at one’s equal or subordinate (or even superior. As a matter of fact, mat is a basis for a whole code system, controlling different military behaviour practices. The problems of the freshers’ adaptation and of the national specificities in the late Soviet and modern Russian army are to be considered with special respect.
Discovery of a Leptospirosis Cluster Amidst a Pneumonic Plague Outbreak in a Miners’ Camp in the Democratic Republic of the Congo

Science.gov (United States)

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
Put to the test

CERN Document Server

Katarina Anthony

2015-01-01

This summer, the HiRadMat (High Radiation to Materials) facility began testing the first HL-LHC collimator jaw prototypes. How they perform when bombarded with high-energy, high-intensity beams will go on to shape the particle accelerators of the future... The three collimator jaws prior to installation in the HiRadMat facility. Preliminary results have found that molybdenum-graphite is by far the most robust of the novel materials. As copper-diamond is denser and more electrically conductive, it may have applications in the HL-LHC collimation system locations less exposed to beam accidents. The HiRadMat facility uses SPS beams to test materials and accelerator components in extreme conditions. As accelerators grow more powerful, they require materials that can withstand extreme conditions of temperature and pressure as well as high levels of radiation. In 2012, in a HiRadMat experiment, six different materials were probed for possible use in collimators and absorbers. The re...
Preface - BraMat 2017

Science.gov (United States)

Munteanu, Daniel

2018-04-01

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

Science.gov (United States)

Giebel, Felix; Picker, Susanne M; Gathof, Birgit S

2008-01-01

SUMMARY: OBJECTIVE: Pretransfusion ABO compatibility testing is a simple and required precaution against ABO-incompatible transfusion, which is one of the greatest threats in transfusion medicine. While distinct agglutination is most important for correct test interpretation, protection against infectious diseases and ease of handling are crucial for accurate test performance. Therefore, the aim of this study was to evaluate differences in test card design, handling, and user safety. DESIGN: Four different bedside test cards with pre-applied antibodies were evaluated by 100 medical students using packed red blood cells of different ABO blood groups. Criteria of evaluation were: agglutination, labelling, handling, and safety regarding possible user injuries. Criteria were rated subjectively according to German school notes ranging from 1 = very good to 6 = very bad/insufficient. RESULTS: Overall, all cards received very good/good marks. The ABO blood group was identified correctly in all cases. Three cards (no. 1, no. 3, no. 4) received statistically significant (p labelling (1.5 vs. 2.2-2.4), handling (1.9-2.0 vs. 2.5), and user safety (2.5 vs. 3.4). Analysis of card self-explanation revealed no remarkable differences. CONCLUSION: Despite good performance of all card systems tested, the best results when including all criteria evaluated were obtained with card no. 4 (particularly concerning clear agglutination), followed by cards no. 2, no. 1, and no. 3.
Vibrio cholerae O1 secretes an extracellular matrix in response to antibody-mediated agglutination.

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Danielle E Baranova

Full Text Available Vibrio cholerae O1 is one of two serogroups responsible for epidemic cholera, a severe watery diarrhea that occurs after the bacterium colonizes the human small intestine and secretes a potent ADP-ribosylating toxin. Immunity to cholera is associated with intestinal anti-lipopolysaccharide (LPS antibodies, which are known to inhibit V. cholerae motility and promote bacterial cell-cell crosslinking and aggregation. Here we report that V. cholerae O1 classical and El Tor biotypes produce an extracellular matrix (ECM when forcibly immobilized and agglutinated by ZAC-3 IgG, an intestinally-derived monoclonal antibody (MAb against the core/lipid A region of LPS. ECM secretion, as demonstrated by crystal violet staining and scanning electron microscopy, occurred within 30 minutes of antibody exposure and peaked by 3 hours. Non-motile mutants of V. cholerae did not secrete ECM following ZAC-3 IgG exposure, even though they were susceptible to agglutination. The ECM was enriched in O-specific polysaccharide (OSP but not Vibrio polysaccharide (VPS. Finally, we demonstrate that ECM production by V. cholerae in response to ZAC-3 IgG was associated with bacterial resistant to a secondary complement-mediated attack. In summary, we propose that V. cholerae O1, upon encountering anti-LPS antibodies in the intestinal lumen, secretes an ECM (or O-antigen capsule possibly as a strategy to shield itself from additional host immune factors and to exit an otherwise inhospitable host environment.
Localized electron transfer rates and microelectrode-based enrichment of microbial communities within a phototrophic microbial mat

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Jerome eBabauta

2014-01-01

Full Text Available 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 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.

Science.gov (United States)

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

Science.gov (United States)

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

1998-01-01

Black mats are prominent features of the late Pleistocene and Holocene stratigraphic record in the southern Great Basin. Faunal, geochemical, and sedimentological evidence shows that the black mats formed in several microenvironments related to spring discharge, ranging from wet meadows to shallow ponds. Small land snails such as Gastrocopta tappaniana and Vertigo berryi are the most common mollusk taxa present. Semiaquatic and aquatic taxa are less abundant and include Catinellids, Fossaria parva, Gyraulus parvus, and others living today in and around perennial seeps and ponds. The ostracodes Cypridopsis okeechobi and Scottia tumida, typical of seeps and low-discharge springs today, as well as other taxa typical of springs and wetlands, are common in the black mats. Several new species that lived in the saturated subsurface also are present, but lacustrine ostracodes are absent. The ??13C values of organic matter in the black mats range from -12 to -26???, reflecting contributions of tissue from both C3 (sedges, most shrubs and trees) and C4 (saltbush, saltgrass) plants. Carbon-14 dates on the humate fraction of 55 black mats fall between 11,800 to 6300 and 2300 14C yr B.P. to modern. The total absence of mats in our sample between 6300 and 2300 14C yr B.P. likely reflects increased aridity associated with the mid-Holocene Altithermal. The oldest black mats date to 11,800-11,600 14C yr B.P., and the peak in the 14C black mat distribution falls at ???10,000 14C yr B.P. As the formation of black mats is spring related, their abundance reflects refilling of valley aquifers starting no later than 11,800 and peaking after 11,000 14C yrB.P. Reactivation of spring-fed channels shortly before 11,200 14C yr B.P. is also apparent in the stratigraphic records from the Las Vegas and Pahrump Valleys. This age distribution suggests that black mats and related spring-fed channels in part may have formed in response to Younger Dryas (YD)-age recharge in the region. However, the
Increasing Mechanical Properties of 2-D-Structured Electrospun Nylon 6 Non-Woven Fiber Mats

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Chunhui Xiang

2016-04-01

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

Science.gov (United States)

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.
Kejadian Leptospirosis pada Anjing di Daerah Istimewa Yogyakarta (CASE OF CANINE LEPTOSPIROSIS IN THE CITY OF YOGYAKARTA

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Guntari Titik Mulyani

2017-09-01

Full Text Available Leptospirosis is a zoonotic disease, which is caused by Leptospira interrogans. The incidence of leptospirosis in dogs varies according to region and season, and is considered as emerging infectious diseases in humans. Clinical symptoms of leptospirosis in dogs vary greatly, some dogs are asymptomatic, with mild symptoms, and others progress to severe illness until death. The study aims to determine cases of canine leptospirosis in Yogyakarta, and identify the serovar that infect them. A total of 20 dogs without symptoms, with mild symptoms, to severe symptoms of leptospirosis were collected their serum and further tested using Microscopic Agglutination Test (MAT conducted at the Center for Veterinary Research (BBLitvet Bogor. History of vaccination is recorded as a consideration in interpreting the MAT results. The results showed that three out of the 20 samples were positive leptospirosis. Of the three positive samples, one was identified as serovar bataviae, another one as serovar bataviae and tarrasovi, and the last as serovar bataviae, tarrasovi, ichterohaemorrhagiae, canicola, celledoni, pyrogenes, cynopteri, and rachmati, respectively. The three dogs with leptospirosis showed similar clinical symptoms i.e. Anorexia, lethargy, and fever. It can be concluded that there are cases of canine leptospirosis in Yogyakarta which is predominantly caused by Leptospira interrogans serovar bataviae. ABSTRAK Leptospirosis adalah penyakit zoonosis, yang disebabkan oleh Leptospira interrogans. Kejadian leptospirosis pada anjing bervariasi menurut wilayah dan musim, dan dianggap sebagai penyakit menular yang muncul pada manusia. Gejala klinis leptospirosis pada anjing sangat bervariasi, beberapa anjing tanpa menunjukkan gejala, dengan gejala ringan, dan yang lain melanjut menjadi penyakit yang parah sampai kematian. Penelitian ini bertujuan untuk mengetahui kasus leptospirosis pada anjing di Propinsi Daerah Istimewa Yogyakarta, dan mengidentifikasi
Engineering and Scientific Applications: Using MatLab(Registered Trademark) for Data Processing and Visualization

Science.gov (United States)

Sen, Syamal K.; Shaykhian, Gholam Ali

2011-01-01

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

Science.gov (United States)

Avalos-Téllez, Rosalía; Carrillo-Casas, Erika M; Atilano-López, Daniel; Godínez-Reyes, Carlos R; Díaz-Aparicio, Efrén; Ramírez-Delgado, David; Ramírez-Echenique, María F; Leyva-Leyva, Margarita; Suzán, Gerardo; Suárez-Güemes, Francisco

2016-04-28

The California sea lion ( Zalophus californianus ), a permanent inhabitant of the Gulf of California in Mexico, is susceptible to pathogenic Leptospira spp. infection, which can result in hepatic and renal damage and may lead to renal failure and death. During summer 2013, we used the microscopic agglutination test (MAT) to investigate the prevalence of anti-Leptospira antibodies in blood of clinically healthy sea lion pups from seven rookery islands on the Pacific Coast of Baja California (Pacific Ocean) and in the Gulf of California. We also used PCR to examine blood for Leptospira DNA. Isolation of Leptospira in liquid media was unsuccessful. We found higher antibody prevalence in sea lions from the rookery islands in the gulf than in those from the Pacific Coast. Antibodies against 11 serovars were identified in the Gulf of California population; the most frequent reactions were against serovars Bataviae (90%), Pyrogenes (86%), Wolffi (86%), Celledoni (71%), and Pomona (65%). In the Pacific Ocean population, MAT was positive against eight serovars, where Wolffi (88%), Pomona (75%), and Bataviae (70%) were the most frequent. Serum samples agglutinated with more than one Leptospira serovar. The maximum titer was 3,200. Each island had a different serology profile, and islands combined showed a distinct profile for each region. We detected pathogenic Leptospira DNA in 63% of blood samples, but we found no saprophytic Leptospira. Positive PCR results were obtained in blood samples with high and low MAT titers. Together, these two methods enhance the diagnosis and interpretation of sea lion leptospirosis. Our results may be related to human activities or the presence of other reservoirs with which sea lions interact, and they may also be related to sea lion stranding.

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

Science.gov (United States)

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.
The heterothallic sugarbeet pathogen Cercospora beticola contains exon fragments of both MAT genes that are homogenized by concerted evolution

NARCIS (Netherlands)

Bolton, M.D.; Jonge, de R.; Inderbitzin, P.; Liu, Z.; Birla, K.; Peer, Van de Y.; Subbarao, K.; Thomma, B.P.H.J.; Secor, G.

2014-01-01

Dothideomycetes is one of the most ecologically diverse and economically important classes of fungi. Sexual reproduction in this group is governed by mating type (MAT) genes at the MAT1 locus. Self-sterile (heterothallic) species contain one of two genes at MAT1 (MAT1-1-1 or MAT1-2-1) and only
Four new species of deep water agglutinated foraminifera from the Oligocene-Miocene of the Congo Fan (offshore Angola)

OpenAIRE

Kender, S.; Kaminski, M. A.; Jones, R. W.

2006-01-01

Four new species of deep-water agglutinated benthic foraminifera are described from the Oligocene and Miocene of the Congo Fan, offshore Angola. Scherochorella congoensis n.sp., Paratrochamminoides goroyskiformis n.sp., Haplophragmoides nauticus n.sp. and Portatrochammina profunda n.sp. all occur in deep-sea turbiditic shales and sands from the distal section of the Congo Fan.
Assembly and Succession of Iron Oxide Microbial Mat Communities in Acidic Geothermal Springs

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Jacob P. Beam

2016-02-01

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

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Elsayed A. Elbadry

2012-01-01

Full Text Available Recycled needle punched jute fiber mats as a first natural fiber reinforcement system and these jute mats used as a core needle punched with recycled jute fabric cloths as skin layers as a second natural fiber reinforcement system were used for unsaturated polyester matrix composites via modifying the hand lay-up technique with resin preimpregnation into the jute fiber in vacuum. The effect of skin jute fabric on the tensile and bending properties of jute mat composites was investigated for different fiber weight contents. Moreover, the notch sensitivity of these composites was also compared by using the characteristic distance do calculated by Finite Element Method (FEM. The results showed that the tensile and flexural properties of jute mat composites increased by increasing the fiber weight content and by adding the jute fabric as skin layers. On the other hand, by adding the skins, the characteristic distance decreased and, therefore, the notch sensitivity of the composites increased. The fracture behavior investigated by SEM showed that extensive fiber pull-out mechanism was revealed at the tension side of jute mat composites under the bending load and by adding the jute cloth, the failure mode of jute mat was changed to fiber bridge mechanism.
Electron microscopy study of microbial mat in the North Fiji basin hydrothermal vent

Science.gov (United States)

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

2017-12-01

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

Science.gov (United States)

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.
Vulnerability of R-MAT networks with communities

Directory of Open Access Journals (Sweden)

Nikolay Alexandrovich Kinash

2016-06-01

Full Text Available A generator R-MAT for modeling networks with different laws of link constructions within and between communities has been developed. Network attack simulations have been performed and pertinent robustness of diverse network combinations has been concluded.
Anti-fatigue mats, low back pain, and electromyography: An interventional study.

Science.gov (United States)

Aghazadeh, Javad; Ghaderi, Mahmoud; Azghani, Mahmood-Reza; Khalkhali, Hamid-Reza; Allahyari, Teimour; Mohebbi, Iraj

2015-01-01

Increasing bilateral gluteus medius co-activation has been identified as one of the most important factors in developing low back pain due to prolonged standing in healthy people. This study aims to investigate the impact of an anti-fatigue mat on the bilateral gluteus medius co-activation pattern and to report the low back pain subjectively in 2 different standing positions on the normal rigid surface and on the anti-fatigue mat. While carrying out an easy simulated profession, 16 participants who had no low back pain background were requested to stand for 2 h in each position, with and without using the anti-fatigue floor mat, respectively. At the beginning of standing process and at every 15 min until the time of 120 min lapses, electric activities for the bilateral gluteus medius co-activation and subjective pain level in low back area were collected by the surface electromyogeraphy (EMG) and the visual analogue scale (VAS), respectively in each position. The obtained findings revealed that the anti-fatigue mat significantly decreased subjective pain level in low back area among 15 participants (p 0.05). The findings obtained under this study related to the impact of the anti-fatigue mat upon the low back pain based on the increase of > 10 mm on the VAS threshold, which showed that this intervention had no significant impact upon decreasing the number of patients suffering from the low back pain and also minimizing the bilateral gluteus medius co-activation in both pain developer groups (p > 0.05). However, 73% of the participants preferred to apply it. It seems that the anti-fatigue mat may be useful in reducing the low back pain although it objectively didn't significantly change the gluteus medius co-activation pattern related to the low back pain. This work is available in Open Access model and licensed under a CC BY-NC 3.0 PL license.
Microbial Diversity and Lipid Abundance in Microbial Mats from a Sulfidic, Saline, Warm Spring in Utah, USA

Science.gov (United States)

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

Directory of Open Access Journals (Sweden)

Miguel A. Hidalgo-Salazar

2018-03-01

Full Text Available 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. Keywords: Biocomposites, Natural materials, Nonwoven Fique fiber mat, LLDPE, Epoxy Resin
Integration of agglutination assay for protein detection in microfluidic disc using Blu-ray optical pickup unit and optical fluid scanning

DEFF Research Database (Denmark)

Uddin, Rokon; Burger, Robert; Donolato, Marco

2015-01-01

We present a novel strategy for thrombin detection by combining a magnetic bead based agglutination assay and low-cost microfluidic disc. The detection method is based on an optomagnetic readout system implemented using a Blu-ray optical pickup unit (OPU) as main optoelectronic component. The ass...
Reproducibilidad de test de aceleración y cambio de dirección en fútbol. [Reproducibility of test acceleration and change of direction in football].

Directory of Open Access Journals (Sweden)

Julio Calleja-González

2015-04-01

Full Text Available El fútbol es un deporte multifacético en donde los factores condicionales y antropométricos son pre-requisitos necesarios para competir a alto nivel. Especialmente la velocidad y la agilidad son necesarias para alcanzar el rendimiento en fútbol. En el estudio participaron 10 jugadores (21,2 ± 2,0 años; 1,81 ± 0,1 m; 73,7 ± 5,9 kg; 22,5 ± 0,8 kg.m-2 con 3 años de experiencia en categoría regional. La reproducibilidad del test de sprint 20 metros y los test de capacidad de cambiar de dirección (MAT y test de sprint con cambios de dirección de 90ºS (90ºS fue analizada mediante el diseñó de test-retest. La reproducibilidad se calculó mediante el Coeficiente de Correlación Intraclase (CCI. La representación de la concordancia entre sesiones mediante el método de Bland y Altman. Los resultados sugieren una reproducibilidad aceptable de los test analizados. Se ha obtenido una asociación moderada entre los dos test de capacidad de cambio de dirección (MAT y 90ºS, r = 0,74. Una baja entre el sprint 20 m y el 90ºS (r = 0,46 y una baja entre el sprint 20 m y el MAT (r = 0,53. Los test de 20 m, MAT y 90ºS mostraron buenos valores de reproducibilidad absoluta y relativa. Podemos afirmar, que se ha obtenido una asociación moderada entre los test de capacidad de cambio de dirección (MAT y 90ºS. Una baja asociación entre el sprint 20 m y el MAT y una asociación baja entre el sprint 20 m y el test de 90ºS. Abstract Soccer is a many-sided sport, where the conditional and anthropometrical factors are necessary pre-requirements to compete in high level. Especially the speed and the agility, they are necessary to reach the yield in soccer. In the study 10 players took part (21,2 ± 2,0 years; 1,81 ± 0,1 m; 73,7 ± 5,9 kg; 22,5 ± 0,8 kg.m-2 with 3 years of experience in regional category. The reproducibility of the 20 meters sprint test and the test of capacity to change direction (MAT and test of sprint with way changes of 90ºS (90
MAT2B promotes adipogenesis by modulating SAMe levels and activating AKT/ERK pathway during porcine intramuscular preadipocyte differentiation

Energy Technology Data Exchange (ETDEWEB)

Zhao, Cunzhen; Chen, Xiaochang; Wu, Wenjing; Wang, Wusu; Pang, Weijun; Yang, Gongshe, E-mail: gsyang999@hotmail.com

2016-05-15

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 MAT2B 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.
Tagging target genes of the mat1-2-1 transcription factor in Fusarium verticillioides (Gibberella fujikuroi MP-A)

NARCIS (Netherlands)

Keszthelyi, A.; Jeney, A.; Kerenyi, Z.; Mendes, O.; Waalwijk, C.; Hornok, L.

2007-01-01

Mating type in filamentous ascomycetes is controlled by idiomorphic alleles, named MAT1-1 and MAT1-2, which contain 1-3 genes. Of these genes MAT1-1-1 and MAT1-2-1 encode putative transcription factors and are thus considered to be the major regulators of sexual communication and mating. Fungi with
Chapitre 4. Matériaux de construction et de décoration

OpenAIRE

Harlé-Sambet, Yvonne; Cabart, Hubert; Charmoillaux, Julie; Girard, Ghislaine

2017-01-01

Si la brique apparaît comme le matériau le plus utilisé lors de la construction du château, on est cependant frappé par la variété des autres matériaux mis en œuvre. Les murs les plus anciens du logis est (XIIe siècle) ainsi que les fondations et le soubassement du château de brique (fin XIIIe siècle) sont constitués de maçonneries de galets liés au mortier. Le galet est en effet le matériau le plus fréquemment utilisé à toutes les époques dans les constructions du bas-Dauphiné. Cependant à B...
Seroprevalence of Toxoplasma gondii and Neospora caninum in feral cats (Felis silvestris catus) in Majorca, Balearic Islands, Spain.

Science.gov (United States)

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

Directory of Open Access Journals (Sweden)

Anne D. Jungblut

2013-01-01

Full Text Available 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.
MatMCNP: A Code for Producing Material Cards for MCNP

Energy Technology Data Exchange (ETDEWEB)

DePriest, Kendall Russell [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Saavedra, Karen C. [American Structurepoint, Inc., Indianapolis, IN (United States)

2014-09-01

A code for generating MCNP material cards (MatMCNP) has been written and verified for naturally occurring, stable isotopes. The program allows for material specification as either atomic or weight percent (fractions). MatMCNP also permits the specification of enriched lithium, boron, and/or uranium. In addition to producing the material cards for MCNP, the code calculates the atomic (or number) density in atoms/barn-cm as well as the multiplier that should be used to convert neutron and gamma fluences into dose in the material specified.
Solid phase radioimmunoassay for quantitation of IgM rheumatoid factor (RF). Comparison with agglutination techniques and radioimmunoprecipitation polyethylene glycol assay (RIPEGA)

Energy Technology Data Exchange (ETDEWEB)

Herrmann, D.; Jaeger, L.; Hein, G.; Henzgen, M.; Fiebig, H.; Schlenvoigt, G.; Vogelsang, H. (Friedrich-Schiller-Universitaet, Jena (German Democratic Republic). Bereich Medizin; Karl-Marx-Universitaet, Leipzig (German Democratic Republic). Sektion Biowissenschaften)

1985-01-01

A solid-phase radioimmunoassay capable of detecting nanogram quantities of human IgM rheumatoid factor using a monoclonal anti-..mu..-chain antibody is described. Human IgG did not interfere with the detection of IgM RF by this method. The small nonspecific binding of nonRF IgM to the human IgG coated tubes utilized in the assay must be corrected for by assaying samples in parallel bovine serum albumin coated control tubes only in cases of deviation of IgM from normal range. 69 coded and randomly arranged sera from patients with rheumatoid arthritis (RA), nonrheumatic joint diseases and healthy adult control subjects were investigated by this method, agglutination techniques as well as RIPEGA. A good correlation between solid-phase radioimmunoassay and agglutination techniques was found. Patients with seropositive RA had significantly higher concentrations of IgM RF than seronegative RA patients or control subjects.

Mekh-mat entrance examinations problems

CERN Document Server

Vardi, I

2000-01-01

This paper provides a complete solution set to 25 ``killer problems'' given to Jewish candidates to the Mekh--mat at Moscow State University during the 1970's and 1980's. Typically, the problems are at the mathematical olympiad level and some feature interesting theorems. However, a number of the problems are flawed, or even completely wrong. The paper therefore includes an evaluation of the problems in the style of a referee report.
Rapid spectrofluorometric screening of poly-hydroxyalkanoate-producing bacteria from microbial mats.

Science.gov (United States)

Berlanga, Mercedes; Montero, M T; Fernández-Borrell, Jordi; Guerrero, Ricardo

2006-06-01

Microbial mat ecosystems are characterized by both seasonal and diel fluctuations in several physicochemical variables, so that resident microorganisms must frequently adapt to the changing conditions of their environment. It has been pointed out that, under stress conditions, bacterial cells with higher contents of poly-hydroxyalkanoates (PHA) survive longer than those with lower PHA content. In the present study, PHA-producing strains from Ebro Delta microbial mats were selected using the Nile red dying technique and the relative accumulation of PHA was monitored during further laboratory cultivation. The number of heterotrophic isolates in trypticase soy agar (TSA) was ca. 107 colony-forming units/g microbial mat. Of these, 100 randomly chosen colonies were replicated on mineral salt agar limited in nitrogen, and Nile red was added to the medium to detect PHA. Orange fluorescence, produced upon binding of the dye to polymer granules in the cell, was detected in approximately 10% of the replicated heterotrophic isolates. The kinetics of PHA accumulation in Pseudomonas putida, and P. oleovorans were compared with those of several of the environmental isolates spectrofluorometry. PHA accumulation, measured as relative fluorescence intensity, resulted in a steady-state concentration after 48 h of incubation in all strains assayed. At 72 h, the maximum fluorescence intensity of each strain incubated with glucose and fructose was usually similar. MAT-28 strain accumulated more PHA than the other isolates. The results show that data obtained from environmental isolates can highly improve studies based on modeling-simulation programs, and that microbial mats constitute an excellent source for the isolation of PHA-producing strains with industrial applications.
Full-Scale Evaluation of DuraDeck (registered trademark) and MegaDeck (trademark) Matting Systems

Science.gov (United States)

2013-07-01

plates studded with threaded bolts were placed ERDC/GSL TR-13-27 10 underneath two pre-drilled corners of the panel. The plates were positioned so...metal plates studded with threaded ERDC/GSL TR-13-27 4 Figure 1. DuraDeck® mat panel, top surface. Figure 2. DuraDeck® mat panel, bottom surface...ERDC/GSL TR-13-27 5 bolts , as shown in Figure 3, underneath the mat corners and then installing special connector nuts from the top surface
Ammolagena clavata (Jones and Parker, 1860), an agglutinated benthic foraminiferal species - first report from the Recent sediments, Arabian Sea, Indian Ocean region

Digital Repository Service at National Institute of Oceanography (India)

Nigam, R.; Mazumder, A.; Saraswat, R.

The rare presence of the agglutinated foraminiferal species Ammolagena clavata is presented for the first time from the Recent sediments of the Indian Ocean region. This species has previously been reported in Recent sediments from all other oceans...
Simulated Carbon Cycling in a Model Microbial Mat.

Science.gov (United States)

Decker, K. L.; Potter, C. S.

2006-12-01

We present here the novel addition of detailed organic carbon cycling to our model of a hypersaline microbial mat ecosystem. This ecosystem model, MBGC (Microbial BioGeoChemistry), simulates carbon fixation through oxygenic and anoxygenic photosynthesis, and the release of C and electrons for microbial heterotrophs via cyanobacterial exudates and also via a pool of dead cells. Previously in MBGC, the organic portion of the carbon cycle was simplified into a black-box rate of accumulation of simple and complex organic compounds based on photosynthesis and mortality rates. We will discuss the novel inclusion of fermentation as a source of carbon and electrons for use in methanogenesis and sulfate reduction, and the influence of photorespiration on labile carbon exudation rates in cyanobacteria. We will also discuss the modeling of decomposition of dead cells and the ultimate release of inorganic carbon. The detailed modeling of organic carbon cycling is important to the accurate representation of inorganic carbon flux through the mat, as well as to accurate representation of growth models of the heterotrophs under different environmental conditions. Because the model ecosystem is an analog of ancient microbial mats that had huge impacts on the atmosphere of early earth, this MBGC can be useful as a biological component to either early earth models or models of other planets that potentially harbor life.
An investigation of electrospun Henna leaves extract-loaded chitosan based nanofibrous mats for skin tissue engineering

Energy Technology Data Exchange (ETDEWEB)

Yousefi, Iman, E-mail: iman_yousefi@ut.ac.ir [School of Chemical Engineering, College of Engineering, University of Tehran, Tehran (Iran, Islamic Republic of); Medical Biomaterials Research Center (MBRC), Tehran University of Medical Sciences, Tehran (Iran, Islamic Republic of); Pakravan, Mehdi [Department of Chemical Engineering, Ecole Polytechnique de Montreal, Montreal, Quebec (Canada); Rahimi, Hoda [Department of Pharmacognosy, School of Pharmacy, Shahid Beheshti University of Medical Sciences, Tehran (Iran, Islamic Republic of); Bahador, Abbas; Farshadzadeh, Zahra [Department of Microbiology, School of Medicine, Tehran University of Medical Sciences, Tehran (Iran, Islamic Republic of); Haririan, Ismael, E-mail: haririan@tums.ac.ir [Medical Biomaterials Research Center (MBRC), Tehran University of Medical Sciences, Tehran (Iran, Islamic Republic of); Department of Pharmaceutical Biomaterial, Tehran University of Medical Sciences, Tehran (Iran, Islamic Republic of); Department of Pharmaceutics, School of Pharmacy, Tehran University of Medical Sciences, Tehran (Iran, Islamic Republic of)

2017-06-01

Wound healing characteristics of some plant extracts have been well known for many years, and they have been utilized for such applications in traditional way. Recently electrospun nanofibrous mats showed promising properties for tissue engineering and especially for skin repair. It is expected that incorporation of plant extracts into such structures could provide higher performance and synergistic effect for biomedical and wound healing applications. The final purpose of this study is to fabricate chitosan based nanofiber mats loaded with a traditional plant extract of Lawsonia inermis (Henna) leaves to enhance the antibacterial efficacy and wound healing of the precursor nanofibers. The morphology, structure, mechanical properties and swelling and weight loss degree of the electrospun nanofibers have been investigated in this study. Antibacterial activity, cell biocompatibility evaluations and in vivo wound healing activity of the abovementioned mats were also studied. The FESEM images of Henna leaves extract-loaded nanofibers proved that homogeneous, smooth and defect free nanofibers of 64–87 nm in diameter have been prepared. Presence of Henna extract in the electrospun fibers was approved by Fourier Transform Infrared spectroscopy. Incorporation of Henna extract into the nanofiber mats exhibited significant synergistic antibacterial activity against bacterial cells. It was well supported by the results of cell viability and proliferation of human foreskin fibroblast cells on the prepared scaffolds. Therefore, the results of this work showed that Henna leaves extract incorporated chitosan nonwoven mats have a great potential to be used as the biodegradable, biobased and antibacterial wound healing dressings. - Highlights: • Henna leaves extract were successfully loaded into chitosan based nanofiber mats. • These mats demonstrated significant synergistic antibacterial activity. • Combined properties of chitosan nanofibers and Henna promoted cell
An investigation of electrospun Henna leaves extract-loaded chitosan based nanofibrous mats for skin tissue engineering

International Nuclear Information System (INIS)

Yousefi, Iman; Pakravan, Mehdi; Rahimi, Hoda; Bahador, Abbas; Farshadzadeh, Zahra; Haririan, Ismael

2017-01-01

Wound healing characteristics of some plant extracts have been well known for many years, and they have been utilized for such applications in traditional way. Recently electrospun nanofibrous mats showed promising properties for tissue engineering and especially for skin repair. It is expected that incorporation of plant extracts into such structures could provide higher performance and synergistic effect for biomedical and wound healing applications. The final purpose of this study is to fabricate chitosan based nanofiber mats loaded with a traditional plant extract of Lawsonia inermis (Henna) leaves to enhance the antibacterial efficacy and wound healing of the precursor nanofibers. The morphology, structure, mechanical properties and swelling and weight loss degree of the electrospun nanofibers have been investigated in this study. Antibacterial activity, cell biocompatibility evaluations and in vivo wound healing activity of the abovementioned mats were also studied. The FESEM images of Henna leaves extract-loaded nanofibers proved that homogeneous, smooth and defect free nanofibers of 64–87 nm in diameter have been prepared. Presence of Henna extract in the electrospun fibers was approved by Fourier Transform Infrared spectroscopy. Incorporation of Henna extract into the nanofiber mats exhibited significant synergistic antibacterial activity against bacterial cells. It was well supported by the results of cell viability and proliferation of human foreskin fibroblast cells on the prepared scaffolds. Therefore, the results of this work showed that Henna leaves extract incorporated chitosan nonwoven mats have a great potential to be used as the biodegradable, biobased and antibacterial wound healing dressings. - Highlights: • Henna leaves extract were successfully loaded into chitosan based nanofiber mats. • These mats demonstrated significant synergistic antibacterial activity. • Combined properties of chitosan nanofibers and Henna promoted cell
Halloysite nanotube-based electrospun ceramic nanofibre mat: a novel support for zeolite membranes

Science.gov (United States)

Chen, Zhuwen; Zeng, Jiaying; Lv, Dong; Gao, Jinqiang; Zhang, Jian; Bai, Shan; Li, Ruili; Hong, Mei; Wu, Jingshen

2016-12-01

Some key parameters of supports such as porosity, pore shape and size are of great importance for fabrication and performance of zeolite membranes. In this study, we fabricated millimetre-thick, self-standing electrospun ceramic nanofibre mats and employed them as a novel support for zeolite membranes. The nanofibre mats were prepared by electrospinning a halloysite nanotubes/polyvinyl pyrrolidone composite followed by a programmed sintering process. The interwoven nanofibre mats possess up to 80% porosity, narrow pore size distribution, low pore tortuosity and highly interconnected pore structure. Compared with the commercial α-Al2O3 supports prepared by powder compaction and sintering, the halloysite nanotube-based mats (HNMs) show higher flux, better adsorption of zeolite seeds, adhesion of zeolite membranes and lower Al leaching. Four types of zeolite membranes supported on HNMs have been successfully synthesized with either in situ crystallization or a secondary growth method, demonstrating good universality of HNMs for supporting zeolite membranes.
Controls on O2 Production in Cyanobacterial Mats and Implications for Earth's Oxygenation

Science.gov (United States)

Dick, Gregory J.; Grim, Sharon L.; Klatt, Judith M.

2018-05-01

Cyanobacterial mats are widely assumed to have been globally significant hot spots of biogeochemistry and evolution during the Archean and Proterozoic, but little is known about their quantitative contributions to global primary productivity or Earth's oxygenation. Modern systems show that mat biogeochemistry is the outcome of concerted activities and intimate interactions between various microbial metabolisms. Emerging knowledge of the regulation of oxygenic and sulfide-driven anoxygenic photosynthesis by versatile cyanobacteria, and their interactions with sulfur-oxidizing bacteria and sulfate-reducing bacteria, highlights how ecological and geochemical processes can control O2 production in cyanobacterial mats in unexpected ways. This review explores such biological controls on O2 production. We argue that the intertwined effects of light availability, redox geochemistry, regulation and competition of microbial metabolisms, and biogeochemical feedbacks result in emergent properties of cyanobacterial mat communities that are all critical yet largely overlooked mechanisms to potentially explain the protracted nature of Earth's oxygenation.
Comparison of three diagnostic methods for the detection of Toxoplasma gondii in free range chickens.

Science.gov (United States)

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

Science.gov (United States)

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.
Magnetoacoustic Tomography with Magnetic Induction (MAT-MI) for Imaging Electrical Conductivity of Biological Tissue: A Tutorial Review

Science.gov (United States)

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 Varian MAT-250 mass spectrometer. Steady isotopes laboratory; Espectrometro de masas Varian MAT-250. Laboratorio de isotopos estables

Energy Technology Data Exchange (ETDEWEB)

Hernandez M, V.; Tavera D, M.L. [Instituto Nacional de Investigaciones Nucleares, A.P. 18-1027, 11801 Mexico D.F. (Mexico)

1997-07-01

This work treats over the performance and applications of the Varian Mat-250 mass spectrometer which is in the environmental isotope laboratory. It can be applied over topics such as: ions formation, acceleration and collimation, ions separation, ions detection, data transformation, sampling, {delta} notation. (Author)
Yerba Mat? (Ilex paraguariensis) Metabolic, Satiety, and Mood State Effects at Rest and during Prolonged Exercise

OpenAIRE

Alkhatib, Ahmad; Atcheson, Roisin

2017-01-01

Yerba Mat? (YM), has become a popular herb ingested for enhancing metabolic health and weight-loss outcomes. No studies have tested the combined metabolic, satiety, and psychomotor effects of YM during exercise. We tested whether YM ingestion affects fatty acid oxidation (FAO), profile of mood state score (POMS), and subjective appetite scale (VAS), during prolonged moderate exercise. Twelve healthy active females were randomized to ingest either 2 g of YM or placebo (PLC) in a repeated-measu...
Spatial patterns and links between microbial community composition and function in cyanobacterial mats

KAUST Repository

Alnajjar, Mohammad Ahmad; Ramette, Alban; Kü hl, Michael; Hamza, Waleed; Klatt, Judith M.; Polerecky, Lubos

2014-01-01

We imaged reflectance and variable fluorescence in 25 cyanobacterial mats from four distant sites around the globe to assess, at different scales of resolution, spatial variabilities in the physiological parameters characterizing their photosynthetic capacity, including the absorptivity by chlorophyll a (Achl), maximum quantum yield of photosynthesis (Ymax), and light acclimation irradiance (Ik). Generally, these parameters significantly varied within individual mats on a sub-millimeter scale, with about 2-fold higher variability in the vertical than in the horizontal direction. The average vertical profiles of Ymax and Ik decreased with depth in the mat, while Achl exhibited a sub-surface maximum. The within-mat variability was comparable to, but often larger than, the between-sites variability, whereas the within-site variabilities (i.e., between samples from the same site) were generally lowest. When compared based on averaged values of their photosynthetic parameters, mats clustered according to their site of origin. Similar clustering was found when the community composition of the mats' cyanobacterial layers were compared by automated ribosomal intergenic spacer analysis (ARISA), indicating a significant link between the microbial community composition and function. Although this link is likely the result of community adaptation to the prevailing site-specific environmental conditions, our present data is insufficient to identify the main factors determining these patterns. Nevertheless, this study demonstrates that the spatial variability in the photosynthetic capacity and light acclimation of benthic phototrophic microbial communities is at least as large on a sub-millimeter scale as it is on a global scale, and suggests that this pattern of variability scaling is similar for the microbial community composition. © 2014 Al-Najjar, Ramette, Kühl, Hamza, Klatt and Polerecky.
Spatial patterns and links between microbial community composition and function in cyanobacterial mats

KAUST Repository

Alnajjar, Mohammad Ahmad

2014-08-06

We imaged reflectance and variable fluorescence in 25 cyanobacterial mats from four distant sites around the globe to assess, at different scales of resolution, spatial variabilities in the physiological parameters characterizing their photosynthetic capacity, including the absorptivity by chlorophyll a (Achl), maximum quantum yield of photosynthesis (Ymax), and light acclimation irradiance (Ik). Generally, these parameters significantly varied within individual mats on a sub-millimeter scale, with about 2-fold higher variability in the vertical than in the horizontal direction. The average vertical profiles of Ymax and Ik decreased with depth in the mat, while Achl exhibited a sub-surface maximum. The within-mat variability was comparable to, but often larger than, the between-sites variability, whereas the within-site variabilities (i.e., between samples from the same site) were generally lowest. When compared based on averaged values of their photosynthetic parameters, mats clustered according to their site of origin. Similar clustering was found when the community composition of the mats\\' cyanobacterial layers were compared by automated ribosomal intergenic spacer analysis (ARISA), indicating a significant link between the microbial community composition and function. Although this link is likely the result of community adaptation to the prevailing site-specific environmental conditions, our present data is insufficient to identify the main factors determining these patterns. Nevertheless, this study demonstrates that the spatial variability in the photosynthetic capacity and light acclimation of benthic phototrophic microbial communities is at least as large on a sub-millimeter scale as it is on a global scale, and suggests that this pattern of variability scaling is similar for the microbial community composition. © 2014 Al-Najjar, Ramette, Kühl, Hamza, Klatt and Polerecky.
Accuracy of a dual path platform (DPP assay for the rapid point-of-care diagnosis of human leptospirosis.

Directory of Open Access Journals (Sweden)

Scott A Nabity

Full Text Available Diagnosis of leptospirosis by the gold standard serologic assay, the microscopic agglutination test (MAT, requires paired sera and is not widely available. We developed a rapid assay using immunodominant Leptospira immunoglobulin-like (Lig proteins in a Dual Path Platform (DPP. This study aimed to evaluate the assay's diagnostic performance in the setting of urban transmission.We determined test sensitivity using 446 acute and convalescent sera from MAT-confirmed case-patients with severe or mild leptospirosis in Brazil. We assessed test specificity using 677 sera from the following groups: healthy residents of a Brazilian slum with endemic transmission, febrile outpatients from the same slum, healthy blood donors, and patients with dengue, hepatitis A, and syphilis. Three operators independently interpreted visual results without knowing specimen status.The overall sensitivity for paired sera was 100% and 73% for severe and mild disease, respectively. In the acute phase, the assay achieved a sensitivity of 85% and 64% for severe and mild leptospirosis, respectively. Within seven days of illness onset, the assay achieved a sensitivity of 77% for severe disease and 60% for mild leptospirosis. Sensitivity of the DPP assay was similar to that for IgM-ELISA and increased with both duration of symptoms (chi-square regression P = 0.002 and agglutinating titer (Spearman ρ = 0.24, P<0.001. Specificity was ≥93% for dengue, hepatitis A, syphilis, febrile outpatients, and blood donors, while it was 86% for healthy slum residents. Inter-operator agreement ranged from very good to excellent (kappa: 0.82-0.94 and test-to-test reproducibility was also high (kappa: 0.89.The DPP assay performed acceptably well for diagnosis of severe acute clinical leptospirosis and can be easily implemented in hospitals and health posts where leptospirosis is a major public health problem. However, test accuracy may need improvement for mild disease and early stage
Discrepancies in Weil-Felix and microimmunofluorescence test results for Rocky Mountain spotted fever.

Science.gov (United States)

Hechemy, K E; Stevens, R W; Sasowski, S; Michaelson, E E; Casper, E A; Philip, R N

1979-01-01

Only 4.2% of 284 single specimens and 17.6% of 51 pairs of sera reactive in Weil-Felix agglutination tests for Rocky Mountain spotted fever were confirmed by a specific Rickettsia rickettsii microimmunofluorescence test. PMID:107194
A Process for the Creation of T-MATS Propulsion System Models from NPSS data

Science.gov (United States)

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

2014-01-01

A modular thermodynamic simulation package called the Toolbox for the Modeling and Analysis of Thermodynamic Systems (T-MATS) has been developed for the creation of dynamic simulations. The T-MATS software is designed as a plug-in for Simulink (Math Works, Inc.) and allows a developer to create system simulations of thermodynamic plants (such as gas turbines) and controllers in a single tool. Creation of such simulations can be accomplished by matching data from actual systems, or by matching data from steady state models and inserting appropriate dynamics, such as the rotor and actuator dynamics for an aircraft engine. This paper summarizes the process for creating T-MATS turbo-machinery simulations using data and input files obtained from a steady state model created in the Numerical Propulsion System Simulation (NPSS). The NPSS is a thermodynamic simulation environment that is commonly used for steady state gas turbine performance analysis. Completion of all the steps involved in the process results in a good match between T-MATS and NPSS at several steady state operating points. Additionally, the T-MATS model extended to run dynamically provides the possibility of simulating and evaluating closed loop responses.
Thermal Protection System Materials (TPSM): 3D MAT

Data.gov (United States)

National Aeronautics and Space Administration — The 3D MAT Project seeks to design and develop a game changing Woven Thermal Protection System (TPS) technology tailored to meet the needs of the Orion Multi-Purpose...

A Modeling Comparison of Methanogenesis from Noncompetitive vs Competitive Substrates in a Simulated Hypersaline Microbial Mat

Science.gov (United States)

Decker, K. L.; Potter, C.; Hoehler, T.

2005-12-01

The well-documented assumption about methanogens that co-occur in hypersaline mat communities with sulfate-reducing bacteria (SRB) is that they rely entirely on non-competitive substrates for methanogenesis. The reason for this is that during sulfate reduction, sulfur-reducing bacteria efficiently utilize H2, leaving a concentration too low for methanogenesis. Early results from recent work on a hypersaline microbial mat from salt evaporation ponds of Guerrero Negro, Baja, Mexico cast doubt that methanogenesis only occurs via non-competitive substrates, because it shows an excess of H2 in the mat rather than a paucity. We explore the use of our simulation model of the microbial biogeochemistry of a hypersaline mat (named MBGC) to compare methane production rates in a 1 cm thick mat when the methanogens use competitive substrates versus noncompetitive substrates. In the `non-competitive substrate' version of the model, methanogens rely exclusively on methylated amines that are accumulated as compatible solutes in cyanobacteria and released after lysis. In contrast, the `competitive substrate' models examine methanogen use of substrates (such as H2 + acetate) with different SRB population sizes (from absent to low). The comparison of these models of methane and sulfide biogeochemistry of a hypersaline mat has both ecological and geobiological significance, as one hypothesis of Archean microbial mats is that they existed in a low sulfate environment.
An experiment to test advanced materials impacted by intense proton pulses at CERN HiRadMat facility

Energy Technology Data Exchange (ETDEWEB)

Bertarelli, A., E-mail: alessandro.bertarelli@cern.ch [CERN, Engineering Department, Mechanical and Materials Engineering Group (EN-MME), CH-1211 Geneva 23 (Switzerland); Berthome, E. [CERN, Engineering Department, Mechanical and Materials Engineering Group (EN-MME), CH-1211 Geneva 23 (Switzerland); Boccone, V. [CERN, Engineering Department, Sources, Targets and Interactions Group (EN-STI), CH-1211 Geneva 23 (Switzerland); Carra, F. [CERN, Engineering Department, Mechanical and Materials Engineering Group (EN-MME), CH-1211 Geneva 23 (Switzerland); Cerutti, F. [CERN, Engineering Department, Sources, Targets and Interactions Group (EN-STI), CH-1211 Geneva 23 (Switzerland); Charitonidis, N. [CERN, Engineering Department, Machines and Experimental Facilities Group (EN-MEF), CH-1211 Geneva 23 (Switzerland); École Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne (Switzerland); Charrondiere, C. [CERN, Engineering Department, Industrial Controls and Engineering Group (EN-ICE), CH-1211 Geneva 23 (Switzerland); Dallocchio, A.; Fernandez Carmona, P.; Francon, P.; Gentini, L.; Guinchard, M.; Mariani, N. [CERN, Engineering Department, Mechanical and Materials Engineering Group (EN-MME), CH-1211 Geneva 23 (Switzerland); Masi, A. [CERN, Engineering Department, Sources, Targets and Interactions Group (EN-STI), CH-1211 Geneva 23 (Switzerland); Marques dos Santos, S.D.; Moyret, P. [CERN, Engineering Department, Mechanical and Materials Engineering Group (EN-MME), CH-1211 Geneva 23 (Switzerland); Peroni, L. [Politecnico di Torino, Department of Mechanical and Aerospace Engineering (DIMEAS), Corso Duca degli Abruzzi 24, 10129 Torino (Italy); Redaelli, S. [CERN, Beams Department, Accelerators and Beams Physics Group (BE-ABP), CH-1211 Geneva 23 (Switzerland); Scapin, M. [Politecnico di Torino, Department of Mechanical and Aerospace Engineering (DIMEAS), Corso Duca degli Abruzzi 24, 10129 Torino (Italy)

2013-08-01

Predicting the consequences of highly energetic particle beams impacting protection devices as collimators or high power target stations is a fundamental issue in the design of state-of-the-art facilities for high-energy particle physics. These complex dynamic phenomena can be successfully simulated resorting to highly non-linear numerical tools (Hydrocodes). In order to produce accurate results, however, these codes require reliable material constitutive models that, at the extreme conditions induced by a destructive beam impact, are scarce and often inaccurate. In order to derive or validate such models a comprehensive, first-of-its-kind experiment has been recently carried out at CERN HiRadMat facility: performed tests entailed the controlled impact of intense and energetic proton pulses on a number of specimens made of six different materials. Experimental data were acquired relying on embedded instrumentation (strain gauges, temperature probes and vacuum sensors) and on remote-acquisition devices (laser Doppler vibrometer and high-speed camera). The method presented in this paper, combining experimental measurements with numerical simulations, may find applications to assess materials under very high strain rates and temperatures in domains well beyond particle physics (severe accidents in fusion and fission nuclear facilities, space debris impacts, fast and intense loadings on materials and structures etc.)
Reefs under Siege—the Rise, Putative Drivers, and Consequences of Benthic Cyanobacterial Mats

Directory of Open Access Journals (Sweden)

Amanda K. Ford

2018-02-01

Full Text Available Benthic cyanobacteria have commonly been a small but integral component of coral reef ecosystems, fulfilling the critical function of introducing bioavailable nitrogen to an inherently oligotrophic environment. Though surveys may have previously neglected benthic cyanobacteria, or grouped them with more conspicuous benthic groups, emerging evidence strongly indicates that they are becoming increasingly prevalent on reefs worldwide. Some species can form mats comprised by a diverse microbial consortium which allows them to exist across a wide range of environmental conditions. This review evaluates the putative driving factors of increasing benthic cyanobacterial mats, including climate change, declining coastal water quality, iron input, and overexploitation of key consumer and ecosystem engineer species. Ongoing global environmental change can increase growth rates and toxin production of physiologically plastic benthic cyanobacterial mats, placing them at a considerable competitive advantage against reef-building corals. Once established, strong ecological feedbacks [e.g., inhibition of coral recruitment, release of dissolved organic carbon (DOC] reinforce reef degradation. The review also highlights previously overlooked implications of mat proliferation, which can extend beyond reef health and affect human health and welfare. Though identifying (opportunistic consumers of mats remains a priority, their perceived low palatability implies that herbivore management alone may be insufficient to control their proliferation and must be accompanied by local measures to improve water quality and watershed management.
HiRadMat: A high‐energy, pulsed beam, material irradiation facility

CERN Multimedia

Charitonidis, Nikolaos

2016-01-01

HiRadMat is a facility constructed in 2011, designed to provide high-intensity pulsed beams to an irradiation area where different material samples or accelerator components can be tested. The facility, located at the CERN SPS accelerator complex, uses a 440 GeV proton beam with a pulse length up to 7.2 μs and a maximum intensity up to 1E13 protons / pulse. The facility, a unique place for performing state-of-the art beam-to-material experiments, operates under transnational access and welcomes and financially supports, under certain conditions, experimental teams to perform their experiments.
Diatom-driven recolonization of microbial mat-dominated siliciclastic tidal flat sediments.

Science.gov (United States)

Pan, Jerónimo; Cuadrado, Diana G; Bournod, Constanza N

2017-10-01

Modern microbial mats and biofilms play a paramount role in sediment biostabilization. When sporadic storms affect tidal flats of Bahía Blanca Estuary, the underlying siliciclastic sediment is exposed by physical disruption of the mat, and in a few weeks' lapse, a microbial community re-establishes. With the objective of studying colonization patterns and the ecological succession of microorganisms at the scale of these erosional structures, these were experimentally made and their biological recolonization followed for 8 weeks, with replication in winter and spring. Motile pennate diatoms led the initial colonization following two distinct patterns: a dominance by Cylindrotheca closterium in winter and by naviculoid and nitzschioid diatoms in spring. During the first 7 days, cell numbers increased 2- to 17-fold. Cell densities further increased exhibiting sigmoidal community growth, reaching 2.9-8.9 × 106 cells cm-3 maxima around day 30; centric diatoms maintained low densities throughout. In 56 days after removal of the original mat, filamentous cyanobacteria that dominate mature mats did not establish a significant biomass, leading to the rejection of the hypothesis that cyanobacteria would drive the colonization. The observed dominance of pennate diatoms is attributed to extrinsic factors determined by tidal flooding, and intrinsic ones, e.g. motility, nutrient affinity and high growth rate. © FEMS 2017. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.
COMPETITION BETWEEN ANOXYGENIC PHOTOTROPHIC BACTERIA AND COLORLESS SULFUR BACTERIA IN A MICROBIAL MAT

NARCIS (Netherlands)

VISSCHER, PT; VANDENENDE, FP; SCHAUB, BEM; VANGEMERDEN, H

The populations of chemolithoautotrophic (colorless) sulfur bacteria and anoxygenic phototrophic bacteria were enumerated in a marine microbial mat. The highest population densities were found in the 0-5 mm layer of the mat: 2.0 X 10(9) cells CM-3 sediment, and 4.0 X 10(7) cells cm-3 sediment for
Perfect simulation and moment properties for the Matérn type III process

DEFF Research Database (Denmark)

Møller, Jesper; Huber, Mark L.; Wolpert, Robert L.

In a seminal work, Bertil Matérn introduced several types of processes for modeling repulsive point processes. In this paper an algorithm is presented for the perfect simulation of the Mat´ern III process within a bounded window in Rd fully accounting for edge effects. A simple upper bound...
Títulos de anticorpos aglutinantes induzidos por vacinas comerciais contra leptospirose bovina Agglutinating antibody titers induced by commercial vaccines against bovine leptospirosis

Directory of Open Access Journals (Sweden)

Gabriela de Godoy Cravo Arduino

2009-07-01

Full Text Available No presente estudo, 100 fêmeas bovinas foram divididas em cinco grupos de 20 animais cada. Os grupos experimentais receberam quatro diferentes vacinas comerciais (B, C, D e E, e um grupo permaneceu como controle. Amostras foram colhidas no dia da aplicação da primeira dose e nos dias 3, 7, 14, 21, 28, 35, 42, 49, 56, 63, 70, 77, 84, 91, 120, 150 e 180 pós-vacinação (PV. A triagem dos animais foi feita pela análise sorológica com 6 antígenos de leptospiras, escolhendo-se os animais não reagentes. Os títulos de anticorpos foram monitorados pela soroaglutinação microscópica (SAM com os sorovares Canicola, Grippotyphosa, Hardjo, Icterohaemorrhagiae, Pomona e Wolffi. Todas as vacinas induziram, aos 3 dias PV, títulos de anticorpos aglutinantes para os sorovares Hardjo e Wolffi, que persistiram até o 150º dia PV. Os sorovares Hardjo e Wolffi induziram os maiores títulos de anticorpos aglutinantes. A vacina D, apesar de não possuir o sorovar Wolffi em sua composição foi capaz de induzir anticorpos aglutinantes contra este sorovar. Somente foram detectados anticorpos contra o sorovar Canicola nos animais vacinados com a bacterina D. A vacina que induziu os maiores títulos médios de anticorpos, considerando todos os sorovares testados foi a D.In the investigation 100 heifers were used, divided into 5 groups of 20 animals each. The four experimental groups were vaccinated using distinct commercial polyvalent bacterines: B, C, D and E, and A group was the control. Samples were collected at days 0, 3, 7, 14, 21, 28, 35, 42, 49, 56, 63, 70, 77, 84, 91, 120, 150 and 180 from the first injection of the vaccine. The selection of the animals for the experimental groups was done based on a serological screening with 6 antigens of Leptospira sp. constituted by non-reagent animals. The vaccine titers were monitored using the microscopic agglutination test (MAT for Canicola, Grippotyphosa, Hardjo, Icterohaemorrhagiae, Pomona and Wolffi
Gro2mat: a package to efficiently read gromacs output in MATLAB.

Science.gov (United States)

Dien, Hung; Deane, Charlotte M; Knapp, Bernhard

2014-07-30

Molecular dynamics (MD) simulations are a state-of-the-art computational method used to investigate molecular interactions at atomic scale. Interaction processes out of experimental reach can be monitored using MD software, such as Gromacs. Here, we present the gro2mat package that allows fast and easy access to Gromacs output files from Matlab. Gro2mat enables direct parsing of the most common Gromacs output formats including the binary xtc-format. No openly available Matlab parser currently exists for this format. The xtc reader is orders of magnitudes faster than other available pdb/ascii workarounds. Gro2mat is especially useful for scientists with an interest in quick prototyping of new mathematical and statistical approaches for Gromacs trajectory analyses. © 2014 Wiley Periodicals, Inc. Copyright © 2014 Wiley Periodicals, Inc.
Fatigue Characteristic of Chopped Strand Mat/Polyester Composite

Directory of Open Access Journals (Sweden)

I Made Astika

2012-11-01

Full Text Available The application of composite as an alternatif material to substitute of metal has better properties than metal such as light, high elasticity, corrosion and fatigue resistance. Some components in its application are subjected to millions of varying stress cycles that initiated to fatigue failure such as crack, delamination and fracture. The strength of composite is influenced by construction, fiber type, orientation and fiber fraction. The objective of this experiment is to investigate the fatigue characteristic on SCM composite. Material composite to be used is glass fiber with chopped strand mat (CSM as fiber and Yukalac 157 BQTN-EX with 1% hardener (Mexpox as matrix. The mold process was built with hand lay-up. Fiber volume fractions in composite are 40, 32 and 24 %. The tests to be done on composite are fatigue and tensile test. The research show that the increasing of fiber fraction in composite affects increasing of fatigue life, endurance limit and tensile strength. Fatigue failure modes of composite are debonding, matrix cracking, delamination and fiber fracture.
Safety Protocols at MAT Lab

International Nuclear Information System (INIS)

Wadawale, A.; Chopade, S.; Chaudhury, K.; Pal, M.K.; Kushwah, N.; Shah, A.Y.; Kedarnath, G.; Priyadarsini, K.I.; Jain, V.K.

2017-01-01

MAT Lab of Chemistry Division, BARC (A Class 10000 Clean room laboratory) has been in operation since 2004 for process development of ultra-purification of several strategically important materials (Ga, As, Sb, In, CsI and Ge) and synthesis of their organometallic compounds. Of these, work related to purification of As, Sb, and In, has been discontinued. Due to high toxicity and pyrophoric nature of some of the compounds, stringent safety regulations were formulated and subsequently implemented by the division
Distinctive fungal and bacterial communities are associated with mats formed by ectomycorrhizal fungi

Science.gov (United States)

Laurel A. Kluber; Jane E. Smith; David D. Myrold

2011-01-01

The distinct rhizomorphic mats formed by ectomycorrhizal Piloderma fungi are common features of the organic soil horizons of coniferous forests of the Pacific Northwest. These mats have been found to cover 25-40% of the forest floor in some Douglas-fir stands, and are associated with physical and biochemical properties that distinguish them from...
Enhanced dechlorination of trichloroethylene using electrospun polymer nanofibrous mats immobilized with iron/palladium bimetallic nanoparticles

Energy Technology Data Exchange (ETDEWEB)

Ma, Hui [State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, Donghua University, Shanghai 201620 (China); College of Chemistry, Chemical Engineering and Biotechnology, Donghua University, Shanghai 201620 (China); Huang, Yunpeng; Shen, Mingwu; Guo, Rui; Cao, Xueyan [College of Chemistry, Chemical Engineering and Biotechnology, Donghua University, Shanghai 201620 (China); Shi, Xiangyang, E-mail: xshi@dhu.edu.cn [State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, Donghua University, Shanghai 201620 (China); College of Chemistry, Chemical Engineering and Biotechnology, Donghua University, Shanghai 201620 (China); CQM - Centro de Quimica da Madeira, Universidade da Madeira, Campus da Penteada, 9000-390 Funchal (Portugal)

2012-04-15

Fe/Pd bimetallic nanoparticles (NPs) have held great promise for treating trichloroethylene (TCE)-contaminated groundwater, without the accumulation of chlorinated intermediates. However, the conventionally used colloidal Fe/Pd NPs usually aggregate rapidly, resulting in a reduced reactivity. To reduce the particle aggregation, we employed electrospun polyacrylic acid (PAA)/polyvinyl alcohol (PVA) polymer nanofibers as a nanoreactor to immobilize Fe/Pd bimetallic NPs. In the study, the water-stable PAA/PVA nanofibrous mats were complexed with Fe (III) ions via the binding with the free carboxyl groups of PAA for subsequent formation and immobilization of zero-valent iron (ZVI) NPs. Fe/Pd bimetallic NPs were then formed by the partial reduction of Pd(II) ions with ZVI NPs. The formed electrospun nanofibrous mats containing Fe/Pd bimetallic NPs with a diameter of 2.8 nm were characterized by scanning electron microscopy, energy-dispersive spectroscopy, transmission electron microscopy, thermogravimetric analysis, and inductively coupled plasma-atomic emission spectroscopy. The Fe/Pd NP-containing electrospun PAA/PVA nanofibrous mats exhibited higher reactivity than that of the ZVI NP-containing mats or colloidal Fe/Pd NPs in the dechlorination of trichloroethylene (TCE), which was used as a model contaminant. With the high surface area to volume ratio, high porosity, and great reusability of the fibrous mats immobilized with the bimetallic NPs, the composite nanofibrous mats should be amenable for applications in remediation of various environmental contaminants.
Enhanced dechlorination of trichloroethylene using electrospun polymer nanofibrous mats immobilized with iron/palladium bimetallic nanoparticles

International Nuclear Information System (INIS)

Ma, Hui; Huang, Yunpeng; Shen, Mingwu; Guo, Rui; Cao, Xueyan; Shi, Xiangyang

2012-01-01

Fe/Pd bimetallic nanoparticles (NPs) have held great promise for treating trichloroethylene (TCE)-contaminated groundwater, without the accumulation of chlorinated intermediates. However, the conventionally used colloidal Fe/Pd NPs usually aggregate rapidly, resulting in a reduced reactivity. To reduce the particle aggregation, we employed electrospun polyacrylic acid (PAA)/polyvinyl alcohol (PVA) polymer nanofibers as a nanoreactor to immobilize Fe/Pd bimetallic NPs. In the study, the water-stable PAA/PVA nanofibrous mats were complexed with Fe (III) ions via the binding with the free carboxyl groups of PAA for subsequent formation and immobilization of zero-valent iron (ZVI) NPs. Fe/Pd bimetallic NPs were then formed by the partial reduction of Pd(II) ions with ZVI NPs. The formed electrospun nanofibrous mats containing Fe/Pd bimetallic NPs with a diameter of 2.8 nm were characterized by scanning electron microscopy, energy-dispersive spectroscopy, transmission electron microscopy, thermogravimetric analysis, and inductively coupled plasma-atomic emission spectroscopy. The Fe/Pd NP-containing electrospun PAA/PVA nanofibrous mats exhibited higher reactivity than that of the ZVI NP-containing mats or colloidal Fe/Pd NPs in the dechlorination of trichloroethylene (TCE), which was used as a model contaminant. With the high surface area to volume ratio, high porosity, and great reusability of the fibrous mats immobilized with the bimetallic NPs, the composite nanofibrous mats should be amenable for applications in remediation of various environmental contaminants.
Vitamin E-loaded silk fibroin nanofibrous mats fabricated by green process for skin care application.

Science.gov (United States)

Sheng, Xiaoyue; Fan, Linpeng; He, Chuanglong; Zhang, Kuihua; Mo, Xiumei; Wang, Hongsheng

2013-05-01

In the present study, we reported fabrication and skin benefit of a novel vitamin E (VE)-loaded silk fibroin (SF) nanofibrous mats. RRR-α-Tocopherol polyethylene glycol 1000 succinate (VE TPGS), a water-soluble derivative of VE, was incorporated into SF nanofiber successfully by aqua solution electrospinning for the first time. Morphology of the composite nanofibers changed with the different amount of VE TPGS: a ribbon-like shape for lower loading dose of VE TPGS, while a round shape for higher loading dose (more than 4% (wt/wt) based on the weight of SF). After treated with 75% (v/v) ethanol vapor, the composite nanofibrous mats showed an excellent water-resistant ability. In vitro study disclosed a sustained release behavior of VE TPGS disassociated from the nanofibrous mats. The mouse skin fibroblasts (L929 cells) cultured on the VE-loaded SF nanofibrous mats spread and proliferated much better than on cover slips. Moreover, the incorporation of VE TPGS was found strengthening the ability of SF nanofibrous mats on protecting the cells against oxidation stress induced by tert-butyl hydroperoxide. Our data presented impressive skin benefits of this VE-loaded SF nanofibrous mats, suggesting a promising applicative potential of this novel product on personal skin care, tissue regeneration and other related area. Copyright © 2013 Elsevier B.V. All rights reserved.
Community Structure of Lithotrophically-Driven Hydrothermal Microbial Mats from the Mariana Arc and Back-Arc

Directory of Open Access Journals (Sweden)

Kevin W. Hager

2017-08-01

Full Text Available The Mariana region exhibits a rich array of hydrothermal venting conditions in a complex geological setting, which provides a natural laboratory to study the influence of local environmental conditions on microbial community structure as well as large-scale patterns in microbial biogeography. We used high-throughput amplicon sequencing of the bacterial small subunit (SSU rRNA gene from 22 microbial mats collected from four hydrothermally active locations along the Mariana Arc and back-arc to explore the structure of lithotrophically-based microbial mat communities. The vent effluent was classified as iron- or sulfur-rich corresponding with two distinct community types, dominated by either Zetaproteobacteria or Epsilonproteobacteria, respectively. The Zetaproteobacterial-based communities had the highest richness and diversity, which supports the hypothesis that Zetaproteobacteria function as ecosystem engineers creating a physical habitat within a chemical environment promoting enhanced microbial diversity. Gammaproteobacteria were also high in abundance within the iron-dominated mats and some likely contribute to primary production. In addition, we also compare sampling scale, showing that bulk sampling of microbial mats yields higher diversity than micro-scale sampling. We present a comprehensive analysis and offer new insights into the community structure and diversity of lithotrophically-driven microbial mats from a hydrothermal region associated with high microbial biodiversity. Our study indicates an important functional role of for the Zetaproteobacteria altering the mat habitat and enhancing community interactions and complexity.
Risk factors of leptospirosis among febrile hospital admissions in northeastern Malaysia.

Science.gov (United States)

Rafizah, A A Noor; Aziah, B D; Azwany, Y N; Imran, M Kamarul; Rusli, A Mohamed; Nazri, S Mohd; Nikman, A Mohd; Nabilah, I; Asma', H Siti; Zahiruddin, W M; Zaliha, I

2013-01-01

Leptospirosis is a worldwide zoonotic disease. Risk factors for the disease may vary among countries. This study was conducted to determine the risk factors of leptospirosis among febrile cases. A hospital-based cross-sectional study was conducted among 999 febrile patients admitted to 10 hospitals in northeastern Malaysia, from August 2010 to February 2011. An interviewer-guided proforma sheet on sociodemography, type of occupation and social history data was distributed to all adult patients with fever on admission. Serum sample for leptospirosis was screened by IgM Enzyme-linked Immunosorbent Assay (IgM ELISA) test and confirmed by Microscopic Agglutination Test (MAT). The cut-off point for positive MAT was ≥ 1:400 titer in single acute specimens. Seroprevalence of leptospirosis was 8.4% (95% CI: 6.8, 10.3) (n=84/999) by MAT. Multiple logistic regression analysis showed that the high risk occupation group (OR: 1.95, 95% CI: 1.22, 3.13) (p=0.005) and history of recent recreational activity (OR: 2.36, 95% CI: 1.46, 3.85) (pMalaysia. Identification of high risk occupational group and history of recent recreational activity will help to increase the index of suspicion to diagnose leptospirosis among febrile inpatients due to its mimicking other common febrile illnesses in Malaysia. Copyright © 2013 Elsevier Inc. All rights reserved.
The Sclerotinia sclerotiorum Mating Type Locus (MAT) Contains a 3.6-kb Region That Is Inverted in Every Meiotic Generation

Science.gov (United States)

Maruthachalam, Karunakaran; Wu, Bo-Ming; Subbarao, Krishna V.

2013-01-01

Sclerotinia sclerotiorum is a fungal plant pathogen and the causal agent of lettuce drop, an economically important disease of California lettuce. The structure of the S. sclerotiorum mating type locus MAT has previously been reported and consists of two idiomorphs that are fused end-to-end as in other homothallics. We investigated the diversity of S. sclerotiorum MAT using a total of 283 isolates from multiple hosts and locations, and identified a novel MAT allele that differed by a 3.6-kb inversion and was designated Inv+, as opposed to the previously known S. sclerotiorum MAT that lacked the inversion and was Inv-. The inversion affected three of the four MAT genes: MAT1-2-1 and MAT1-2-4 were inverted and MAT1-1-1 was truncated at the 3’-end. Expression of MAT genes differed between Inv+ and Inv- isolates. In Inv+ isolates, only one of the three MAT1-2-1 transcript variants of Inv- isolates was detected, and the alpha1 domain of Inv+ MAT1-1-1 transcripts was truncated. Both Inv- and Inv+ isolates were self-fertile, and the inversion segregated in a 1∶1 ratio regardless of whether the parent was Inv- or Inv+. This suggested the involvement of a highly regulated process in maintaining equal proportions of Inv- and Inv+, likely associated with the sexual state. The MAT inversion region, defined as the 3.6-kb MAT inversion in Inv+ isolates and the homologous region of Inv- isolates, was flanked by a 250-bp inverted repeat on either side. The 250-bp inverted repeat was a partial MAT1-1-1 that through mediation of loop formation and crossing over, may be involved in the inversion process. Inv+ isolates were widespread, and in California and Nebraska constituted half of the isolates examined. We speculate that a similar inversion region may be involved in mating type switching in the filamentous ascomycetes Chromocrea spinulosa, Sclerotinia trifoliorum and in certain Ceratocystis species. PMID:23457637
Comment on "Performance of a spin based insulated gate field effect transistor" [cond-mat/0603260] [cond-mat/0603260

OpenAIRE

Bandyopadhyay, S.; Cahay, M.

2006-01-01

In a recent e-print [cond-mat/0603260] Hall and Flatte claim that a particular spin based field effect transistor (SPINFET), which they have analyzed, will have a lower threshold voltage, lower switching energy and lower leakage current than a comparable metal oxide semiconductor field effect transistor (MOSFET). Here, we show that all three claims of HF are invalid.
The false sero-negativity of brucella standard agglutination test: Prozone phenomenon

Directory of Open Access Journals (Sweden)

İrfan Binici

2011-12-01

Full Text Available Objectives: We aimed to assess prozone phenomenon that is quite rare and causes false negativity in serological diagnosisof brucellosis with standard dilution titers.Materials and methods: In this study the tests of four cases that have false negative serological results were evaluated.Blood cultures were obtained from all cases while cerebrospinal fluid cultures were studied in the two cases. Standardagglutination test (SAT and Coombs test were performed to all patients.Results: SAT and Coombs test was negative in titers up to 1/640 in all cases. The SAT and Coombs tests in cerebrospinalfluid (CSF of the two cases with neurobrucellosis diagnosis were negative, as well. Since the clinical and laboratoryfindings suggested the brucellosis, the serums were restudied by diluting up to 1/10240 titer and we saw that the first3 cases became positive at a titer of 1/1280. The fourth case remained negative and therefore, we applied high dilutionCoombs test. This time the test gave a positive result at 1/10240 titer beginning from 1/2560 titer. B.melitensis wasisolated from two cases.Conclusion: SAT and Coombs’ test must be diluted to titers 1/2560 or more in order to exclude false sero-negativity incases with clinical and laboratory findings suggesting brucellosis. J Microbiol Infect Dis 2011; 1(3:110-113

Rapid reactivation of cyanobacterial photosynthesis and migration upon rehydration of desiccated marine microbial mats

Directory of Open Access Journals (Sweden)

Arjun eChennu

2015-12-01

Full Text Available Desiccated cyanobacterial mats are the dominant biological feature in the Earth's arid zones. While the response of desiccated cyanobacteria to rehydration is well documented for terrestrial systems, information about the response in marine systems is lacking. We used high temporal resolution hyperspectral imaging, liquid chromatography, pulse-amplitude fluorometry, oxygen microsensors and confocal laser microscopy to study this response in a desiccated microbial mat from Exmouth Gulf, Australia. During the initial 15 minutes after rehydration chlorophyll a concentrations increased 2-5 fold and cyanobacterial photosynthesis was re-established. Although the mechanism behind this rapid increase of chlorophyll a remains unknown, we hypothesize that it involves resynthesis from a precursor stored in desiccated cyanobacteria. The subsequent phase (15 min – 48 h involved migration of the reactivated cyanobacteria towards the mat surface, which led, together with a gradual increase in chlorophyll a, to a further increase in photosynthesis. We conclude that the response involving an increase in chlorophyll a and recovery of photosynthetic activity within minutes after rehydration is common for cyanobacteria from desiccated mats of both terrestrial and aquatic origin. However the response of upward migration and its triggering factor appears to be mat-specific and likely linked to other factors.
Rapid Reactivation of Cyanobacterial Photosynthesis and Migration upon Rehydration of Desiccated Marine Microbial Mats

KAUST Repository

Chennu, Arjun

2015-12-24

Desiccated cyanobacterial mats are the dominant biological feature in the Earth’s arid zones. While the response of desiccated cyanobacteria to rehydration is well-documented for terrestrial systems, information about the response in marine systems is lacking. We used high temporal resolution hyperspectral imaging, liquid chromatography, pulse-amplitude fluorometry, oxygen microsensors, and confocal laser microscopy to study this response in a desiccated microbial mat from Exmouth Gulf, Australia. During the initial 15 min after rehydration chlorophyll a concentrations increased 2–5 fold and cyanobacterial photosynthesis was re-established. Although the mechanism behind this rapid increase of chlorophyll a remains unknown, we hypothesize that it involves resynthesis from a precursor stored in desiccated cyanobacteria. The subsequent phase (15 min–48 h) involved migration of the reactivated cyanobacteria toward the mat surface, which led, together with a gradual increase in chlorophyll a, to a further increase in photosynthesis. We conclude that the response involving an increase in chlorophyll a and recovery of photosynthetic activity within minutes after rehydration is common for cyanobacteria from desiccated mats of both terrestrial and marine origin. However, the response of upward migration and its triggering factor appear to be mat-specific and likely linked to other factors.
Rapid Reactivation of Cyanobacterial Photosynthesis and Migration upon Rehydration of Desiccated Marine Microbial Mats

KAUST Repository

Chennu, Arjun; Grinham, Alistair; Polerecky, Lubos; de Beer, Dirk; Alnajjar, Mohammad Ahmad

2015-01-01

Desiccated cyanobacterial mats are the dominant biological feature in the Earth’s arid zones. While the response of desiccated cyanobacteria to rehydration is well-documented for terrestrial systems, information about the response in marine systems is lacking. We used high temporal resolution hyperspectral imaging, liquid chromatography, pulse-amplitude fluorometry, oxygen microsensors, and confocal laser microscopy to study this response in a desiccated microbial mat from Exmouth Gulf, Australia. During the initial 15 min after rehydration chlorophyll a concentrations increased 2–5 fold and cyanobacterial photosynthesis was re-established. Although the mechanism behind this rapid increase of chlorophyll a remains unknown, we hypothesize that it involves resynthesis from a precursor stored in desiccated cyanobacteria. The subsequent phase (15 min–48 h) involved migration of the reactivated cyanobacteria toward the mat surface, which led, together with a gradual increase in chlorophyll a, to a further increase in photosynthesis. We conclude that the response involving an increase in chlorophyll a and recovery of photosynthetic activity within minutes after rehydration is common for cyanobacteria from desiccated mats of both terrestrial and marine origin. However, the response of upward migration and its triggering factor appear to be mat-specific and likely linked to other factors.
Diatom, cyanobacterial and microbial mats as indicators of hydrocarbon contaminated Arctic streams and waters

Energy Technology Data Exchange (ETDEWEB)

Ziervogel, H.; Selann, J.; Adeney, B. [EBA Engineering Consultants Ltd., Edmonton, AB (Canada); Nelson, J.A. [J.B. Services, Sarnia, ON (Canada); Murdock, E. [Nunavut Power, Iqaluit (Canada)

2003-07-01

An environmental assessment conducted at Repulse Bay, Nunavut in the summer of 2001 revealed a recent diesel spill flowing from the groundwater into a creek. The spill had not been reported. When Arctic surface waters mix with hydrocarbon impacted groundwater and sediments, distinctive mats of diatom, cyanobacteria and other bacteria are formed. These mats have the potential for phytoremediation of hydrocarbons. This paper explained the apparent dominance of mats in contaminated Arctic waters and why they promote biodegradation of hydrocarbons. Hydrocarbon-contaminated soils and groundwater are generally anaerobic. The higher dissolved carbon dioxide in polluted soils and groundwater can benefit photosynthetic cyanobacteria and diatom found in oligotrophic, lower alkalinity Arctic waters. The anaerobic and aerobic bacteria can potentially take advantage of the hydrogen substrate and the nitrogen fixing abilities of the cyanobacteria. Zooplankton predators may be killed off by the toxicity of the polluted groundwater. The paper provides examples where a microbial mat reduced the sulfate content of a hydrocarbon-impacted Arctic stream by 100 ppm, and where a pond covered in a benthic microbial mat showed no evidence of hydrocarbons in the water overlying sediments contaminated with hydrocarbons at concentrations measured at 30,000 ppm. 19 refs., 3 tabs., 8 figs.
Counting viruses and bacteria in photosynthetic microbial mats

NARCIS (Netherlands)

Carreira, C; Staal, M.; Middelboe, M.; Brussaard, C.P.D.

2015-01-01

Viral abundances in benthic environments are the highest found in aquatic systems. Photosynthetic microbial mats represent benthic environments with high microbial activity and possibly high viral densities, yet viral abundances have not been examined in such systems. Existing extraction procedures
Production and Consumption of Hydrogen in Hot Spring Microbial Mats Dominated by a Filamentous Anoxygenic Photosynthetic Bacterium

Science.gov (United States)

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
The mating type locus (MAT and sexual reproduction of Cryptococcus heveanensis: insights into the evolution of sex and sex-determining chromosomal regions in fungi.

Directory of Open Access Journals (Sweden)

Banu Metin

2010-05-01

Full Text Available Mating in basidiomycetous fungi is often controlled by two unlinked, multiallelic loci encoding homeodomain transcription factors or pheromones/pheromone receptors. In contrast to this tetrapolar organization, Cryptococcus neoformans/Cryptococcus gattii have a bipolar mating system, and a single biallelic locus governs sexual reproduction. The C. neoformans MAT locus is unusually large (>100 kb, contains >20 genes, and enhances virulence. Previous comparative genomic studies provided insights into how this unusual MAT locus might have evolved involving gene acquisitions into two unlinked loci and fusion into one contiguous locus, converting an ancestral tetrapolar system to a bipolar one. Here we tested this model by studying Cryptococcus heveanensis, a sister species to the pathogenic Cryptococcus species complex. An extant sexual cycle was discovered; co-incubating fertile isolates results in the teleomorph (Kwoniella heveanensis with dikaryotic hyphae, clamp connections, septate basidia, and basidiospores. To characterize the C. heveanensis MAT locus, a fosmid library was screened with C. neoformans/C. gattii MAT genes. Positive fosmids were sequenced and assembled to generate two large probably unlinked MAT gene clusters: one corresponding to the homeodomain locus and the other to the pheromone/receptor locus. Strikingly, two divergent homeodomain genes (SXI1, SXI2 are present, similar to the bE/bW Ustilago maydis paradigm, suggesting one or the other homeodomain gene was recently lost in C. neoformans/C. gattii. Sequencing MAT genes from other C. heveanensis isolates revealed a multiallelic homeodomain locus and at least a biallelic pheromone/receptor locus, similar to known tetrapolar species. Taken together, these studies reveal an extant C. heveanensis sexual cycle, define the structure of its MAT locus consistent with tetrapolar mating, and support the proposed evolutionary model for the bipolar Cryptococcus MAT locus revealing
Bioremediation of mixed microbial mats: System development of mixed contaminants for application at the Savannah River Site. Annual technical progress report, October 1, 1995--September 30, 1996

International Nuclear Information System (INIS)

Bender, J.; Phillips, P.

1996-01-01

The fundamental objective of this project is to develop and field test the mixed microbial mat bioremediation system for decontamination of target sites at SRS. Although microbial mats have performed well in several pilot projects in the past, atypical problems and site characteristics at SRS demand special field designs. In the interest of designing a pilot and locating it at an appropriate site, the project investigators have worked closely with the technical staff at the SREL. We have concluded that the diverse characteristics of contaminations at SRS may dictate testing several pilot designs during the course of this project
Super-Hydrophobic High Throughput Electrospun Cellulose Acetate (CA) Nanofibrous Mats as Oil Selective Sorbents

Science.gov (United States)

Han, Chao

The threat of oil pollution increases with the expansion of oil exploration and production activities, as well as the industrial growth around the world. Use of sorbents is a common method to deal with the oil spills. In this work, an advanced sorbent technology is described. A series of non-woven Cellulose Acetate (CA) nanofibrous mats with a 3D fibrous structure were synthesized by a novel high-throughput electrospinning technique. The precursor was solutions of CA/ acetic acid-acetone in various concentrations. Among them, 15.0% CA exhibits a superhydrophobic surface property, with a water contact angle of 128.95°. Its oil sorption capacity is many times higher the oil sorption capacity of the best commercial sorbent available in the market. Also, it showed good buoyancy properties on the water both as dry-mat and oil-saturated mat. In addition, it is biodegradable, easily available, easily manufactured, so the CA nanofibrous mat is an excellent candidate as oil sorbent for oil spill in water treatment.
Millimeter Wavelength Observations of Galactic Sources with the Mobile Anisotropy Telescope (MAT)

Science.gov (United States)

Cruz, K. L.; Caldwell, R.; Devlin, M. J.; Dorwart, W. B.; Herbig, T.; Miller, A. D.; Nolta, M. R.; Page, L. A.; Puchalla, J. L.; Torbet, E.; Tran, H. T.

1999-12-01

The Mobile Anisotropy Telescope (MAT) has completed two observing seasons (1997 and 1998) in Chile from the Cerro Toco site. Although the primary goal of MAT was to measure anisotropy in the Cosmic Microwave Background (CMB) radiation, the chosen observation scheme also allowed daily viewing of the Galactic Plane. We present filtered maps at 30, 40 and 144 GHz of a region of the Galactic Plane which contains several millimeter-bright regions including the Carinae nebula and IRAS 11097-6102. We report the best fit brightness temperatures as well as the total flux densities in the MAT beams (0.9, 0.6 and 0.2 degrees FWHM) . The data are calibrated with respect to Jupiter whose flux is known to better than 8% in all frequency bands. This work was funded by the National Science Foundation and the Packard Foundation.
Mats and LaSpec: High-precision experiments using ion traps and lasers at Fair

Energy Technology Data Exchange (ETDEWEB)

Rodriguez, D.; Lallena, A.M.; Blaum, K.; Bohm, C.; Cakirli, R.B.; Crespo Lopez-Urrutia, J.R.; Eliseev, S.; Ketelaer, J.; Kreim, M.S.; Kowalska, M.; Litvinov, Y.A.; Nagy, S.; Neidherr, D.; Repp, J.; Roux, C.; Schabinger, B.; Ullrich, J.; Nortershauser, W.; Eberhardt, K.; Geppert, C.; Kramer, J.; Krieger, A.; Sanchez, R.; Ahammed, M.; Das, P.; Ray, A.; Algora, A.; Rubio, B.; Tain, J.L.; Audi, G.; Lunney, D.; Naimi, S.; Aysto, J.; Jokinen, A.; Kolhinen, V.; Moore, I.; Beck, D.; Block, M.; Geissel, H.; Heinz, S.; Herfurth, F.; Litvinov, Y.A.; Minaya-Ramirez, E.; Plab, W.R.; Quint, W.; Scheidenberger, C.; Winkler, M.; Bender, M.; Billowes, J.; Campbell, P.; Flanagan, K.T.; Schwarz, S.; Bollen, G.; Ferrer, R.; George, S.; Kester, O.; Brodeur, M.; Brunner, T.; Delheij, P.; Dilling, J.; Ettenauer, S.; Lapierre, A.; Bushaw, B.A.; Cano-Ott, D.; Martinez, T.; Cortes, G.; Gomez-Hornillos, M.B.; Dax, A.; Herlert, A.; Yordanov, D.; De, A.; Dickel, T.; Geissel, H.; Jesch, C.; Kuhl, T.; Petrick, M.; PlaB, W.R.; Scheidenberger, C.; Garcia-Ramos, J.E.; Gartzke, E.; Habs, D.; Szerypo, J.; Thirolf, P.G.; Weber, C.; Gusev, Y.; Nesterenko, D.; Novikov, Y.N.; Popov, A.; Seliverstov, M.; Vasiliev, A.; Vorobjev, G.; Heenen, P.H.; Marx, G.; Schweikhard, L.; Ziegler, F.; Hobein, M.; Schuch, R.; Solders, A.; Suhonen, M.; Huber, G.; Wendt, K.; Huyse, M.; Koudriavtsev, I.; Neyens, G.; Van Duppen, P.; Le Blanc, F.; Matos, M.; Reinhard, P.G.; Schneider, D.

2010-05-15

Nuclear ground state properties including mass, charge radii, spins and moments can be determined by applying atomic physics techniques such as Penning-trap based mass spectrometry and laser spectroscopy. The MATS and LaSpec setups at the low-energy beamline at FAIR will allow us to extend the knowledge of these properties further into the region far from stability. With MATS (Precision Measurements of very short-lived nuclei using an Advanced Trapping System for highly-charged ions) at FAIR we aim to apply several techniques to very short-lived radionuclides: High-accuracy mass measurements, in-trap conversion electron and alpha spectroscopy, and trap-assisted spectroscopy. The experimental setup of MATS is a unique combination of an electron beam ion trap for charge breeding, ion traps for beam preparation, and a high-precision Penning trap system for mass measurements and decay studies. For the mass measurements, MATS offers both a high accuracy and a high sensitivity. A relative mass uncertainty of 10{sup -9} can be reached by employing highly-charged ions and a non-destructive Fourier-Transform Ion-Cyclotron-Resonance (FT-ICR) detection technique on single stored ions. Decay studies in ion traps will become possible with MATS. Laser spectroscopy of radioactive isotopes and isomers is an efficient and model-independent approach for the determination of nuclear ground and isomeric state properties. Hyperfine structures and isotope shifts in electronic transitions exhibit readily accessible information on the nuclear spin, magnetic dipole and electric quadrupole moments as well as root-mean-square charge radii. The accuracy of laser-spectroscopic-determined nuclear properties is very high while requirements concerning production rates are moderate. This Technical Design Report describes a new Penning trap mass spectrometry setup as well as a number of complementary experimental devices for laser spectroscopy. Since MATS and LaSpec require high-quality low
Mats and LaSpec: High-precision experiments using ion traps and lasers at Fair

International Nuclear Information System (INIS)

Rodriguez, D.; Lallena, A.M.; Blaum, K.; Bohm, C.; Cakirli, R.B.; Crespo Lopez-Urrutia, J.R.; Eliseev, S.; Ketelaer, J.; Kreim, M.S.; Kowalska, M.; Litvinov, Y.A.; Nagy, S.; Neidherr, D.; Repp, J.; Roux, C.; Schabinger, B.; Ullrich, J.; Nortershauser, W.; Eberhardt, K.; Geppert, C.; Kramer, J.; Krieger, A.; Sanchez, R.; Ahammed, M.; Das, P.; Ray, A.; Algora, A.; Rubio, B.; Tain, J.L.; Audi, G.; Lunney, D.; Naimi, S.; Aysto, J.; Jokinen, A.; Kolhinen, V.; Moore, I.; Beck, D.; Block, M.; Geissel, H.; Heinz, S.; Herfurth, F.; Litvinov, Y.A.; Minaya-Ramirez, E.; Plab, W.R.; Quint, W.; Scheidenberger, C.; Winkler, M.; Bender, M.; Billowes, J.; Campbell, P.; Flanagan, K.T.; Schwarz, S.; Bollen, G.; Ferrer, R.; George, S.; Kester, O.; Brodeur, M.; Brunner, T.; Delheij, P.; Dilling, J.; Ettenauer, S.; Lapierre, A.; Bushaw, B.A.; Cano-Ott, D.; Martinez, T.; Cortes, G.; Gomez-Hornillos, M.B.; Dax, A.; Herlert, A.; Yordanov, D.; De, A.; Dickel, T.; Geissel, H.; Jesch, C.; Kuhl, T.; Petrick, M.; PlaB, W.R.; Scheidenberger, C.; Garcia-Ramos, J.E.; Gartzke, E.; Habs, D.; Szerypo, J.; Thirolf, P.G.; Weber, C.; Gusev, Y.; Nesterenko, D.; Novikov, Y.N.; Popov, A.; Seliverstov, M.; Vasiliev, A.; Vorobjev, G.; Heenen, P.H.; Marx, G.; Schweikhard, L.; Ziegler, F.; Hobein, M.; Schuch, R.; Solders, A.; Suhonen, M.; Huber, G.; Wendt, K.; Huyse, M.; Koudriavtsev, I.; Neyens, G.; Van Duppen, P.; Le Blanc, F.; Matos, M.; Reinhard, P.G.; Schneider, D.

2010-01-01

Nuclear ground state properties including mass, charge radii, spins and moments can be determined by applying atomic physics techniques such as Penning-trap based mass spectrometry and laser spectroscopy. The MATS and LaSpec setups at the low-energy beamline at FAIR will allow us to extend the knowledge of these properties further into the region far from stability. With MATS (Precision Measurements of very short-lived nuclei using an Advanced Trapping System for highly-charged ions) at FAIR we aim to apply several techniques to very short-lived radionuclides: High-accuracy mass measurements, in-trap conversion electron and alpha spectroscopy, and trap-assisted spectroscopy. The experimental setup of MATS is a unique combination of an electron beam ion trap for charge breeding, ion traps for beam preparation, and a high-precision Penning trap system for mass measurements and decay studies. For the mass measurements, MATS offers both a high accuracy and a high sensitivity. A relative mass uncertainty of 10 -9 can be reached by employing highly-charged ions and a non-destructive Fourier-Transform Ion-Cyclotron-Resonance (FT-ICR) detection technique on single stored ions. Decay studies in ion traps will become possible with MATS. Laser spectroscopy of radioactive isotopes and isomers is an efficient and model-independent approach for the determination of nuclear ground and isomeric state properties. Hyperfine structures and isotope shifts in electronic transitions exhibit readily accessible information on the nuclear spin, magnetic dipole and electric quadrupole moments as well as root-mean-square charge radii. The accuracy of laser-spectroscopic-determined nuclear properties is very high while requirements concerning production rates are moderate. This Technical Design Report describes a new Penning trap mass spectrometry setup as well as a number of complementary experimental devices for laser spectroscopy. Since MATS and LaSpec require high-quality low-energy beams
Multifunctional ZnO/Nylon 6 nanofiber mats by an electrospinning–electrospraying hybrid process for use in protective applications

Directory of Open Access Journals (Sweden)

Narendiran Vitchuli, Quan Shi, Joshua Nowak, Kathryn Kay, Jane M Caldwell, Frederick Breidt, Mohamed Bourham, Marian McCord and Xiangwu Zhang

2011-01-01

Full Text Available ZnO/Nylon 6 nanofiber mats were prepared by an electrospinning–electrospraying hybrid process in which ZnO nanoparticles were dispersed on the surface of Nylon 6 nanofibers without becoming completely embedded. The prepared ZnO/Nylon 6 nanofiber mats were evaluated for their abilities to kill bacteria or inhibit their growth and to catalytically detoxify chemicals. Results showed that these ZnO/Nylon 6 nanofiber mats had excellent antibacterial efficiency (99.99% against both the Gram-negative Escherichia coli and Gram-positive Bacillus cereus bacteria. In addition, they exhibited good detoxifying efficiency (95% against paraoxon, a simulant of highly toxic chemicals. ZnO/Nylon 6 nanofiber mats were also deposited onto nylon/cotton woven fabrics and the nanofiber mats did not significantly affect the moisture vapor transmission rates and air permeability values of the fabrics. Therefore, ZnO/Nylon 6 nanofiber mats prepared by the electrospinning–electrospraying hybrid process are promising material candidates for protective applications.
Multifunctional ZnO/Nylon 6 nanofiber mats by an electrospinning-electrospraying hybrid process for use in protective applications

Energy Technology Data Exchange (ETDEWEB)

Vitchuli, Narendiran; Shi Quan; McCord, Marian; Zhang Xiangwu [Fiber and Polymer Science Program, Department of Textile Engineering, Chemistry and Science, North Carolina State University, Raleigh, NC 27695-8301 (United States); Nowak, Joshua; Bourham, Mohamed [Department of Nuclear Engineering, North Carolina State University, Raleigh, NC 27695-7909 (United States); Kay, Kathryn [Department of Microbiology, North Carolina State University, Raleigh, NC 27695-7610 (United States); Caldwell, Jane M; Breidt, Frederick, E-mail: bourham@ncsu.edu, E-mail: mmccord@ncsu.edu, E-mail: xiangwu_zhang@ncsu.edu [Department of Food Science, North Carolina Agricultural Research Service, North Carolina State University, Raleigh, NC 27695-7624 (United States)

2011-10-15

ZnO/Nylon 6 nanofiber mats were prepared by an electrospinning-electrospraying hybrid process in which ZnO nanoparticles were dispersed on the surface of Nylon 6 nanofibers without becoming completely embedded. The prepared ZnO/Nylon 6 nanofiber mats were evaluated for their abilities to kill bacteria or inhibit their growth and to catalytically detoxify chemicals. Results showed that these ZnO/Nylon 6 nanofiber mats had excellent antibacterial efficiency (99.99%) against both the Gram-negative Escherichia coli and Gram-positive Bacillus cereus bacteria. In addition, they exhibited good detoxifying efficiency (95%) against paraoxon, a simulant of highly toxic chemicals. ZnO/Nylon 6 nanofiber mats were also deposited onto nylon/cotton woven fabrics and the nanofiber mats did not significantly affect the moisture vapor transmission rates and air permeability values of the fabrics. Therefore, ZnO/Nylon 6 nanofiber mats prepared by the electrospinning-electrospraying hybrid process are promising material candidates for protective applications.
Soft Soil Impact Testing and Simulation of Aerospace Structures

Science.gov (United States)

Fasanella, Edwin L.; Jackson, Karen E.; Kellas, Sotiris

2008-01-01

In June 2007, a 38-ft/s vertical drop test of a 5-ft-diameter, 5-ft-long composite fuselage section that was retrofitted with a novel composite honeycomb Deployable Energy Absorber (DEA) was conducted onto unpacked sand. This test was one of a series of tests to evaluate the multi-terrain capabilities of the DEA and to generate test data for model validation. During the test, the DEA crushed approximately 6-in. and left craters in the sand of depths ranging from 7.5- to 9-in. A finite element model of the fuselage section with DEA was developed for execution in LS-DYNA, a commercial nonlinear explicit transient dynamic code. Pre-test predictions were generated in which the sand was represented initially as a crushable foam material MAT_CRUSHABLE_FOAM (Mat 63). Following the drop test, a series of hemispherical penetrometer tests were conducted to assist in soil characterization. The penetrometer weighed 20-lb and was instrumented with a tri-axial accelerometer. Drop tests were performed at 16-ft/s and crater depths were measured. The penetrometer drop tests were simulated as a means for developing a more representative soil model based on a soil and foam material definition MAT_SOIL_AND FOAM (Mat 5) in LS-DYNA. The model of the fuselage with DEA was reexecuted using the updated soil model and test-analysis correlations are presented.
Detection of Toxoplasma gondii DNA in horse meat from supermarkets in France and performance evaluation of two serological tests

Directory of Open Access Journals (Sweden)

Aroussi Abdelkrim

2015-01-01

Full Text Available In France, some cases of severe toxoplasmosis have been linked to the consumption of horse meat that had been imported from the American continent where atypical strains of Toxoplasma gondii are more common than in Europe. Many seroprevalence studies are presented in the literature but risk assessment of T. gondii infection after horse meat consumption is not possible in the absence of validated serological tests and the unknown correlation between detection of antibodies against T. gondii and presence of tissue cysts. We performed magnetic-capture polymerase chain reaction (MC-PCR to detect T. gondii DNA in 231 horse meat samples purchased in supermarkets in France and evaluated the performance and level of agreement of the modified agglutination test (MAT and enzyme-linked immunosorbent assay (ELISA in the meat juices. The serological tests lacked sensitivity, specificity, and agreement between them, and there was no correlation with the presence of T. gondii DNA in horse meat, raising concerns about the reliability of T. gondii seroprevalence data in horses from the literature. T. gondii DNA was detected in 43% of horse meat samples but the absence of strain isolation in mice following inoculation of more than 100 horse meat samples suggests a low distribution of cysts in skeletal muscles and a low risk of T. gondii infection associated with horse meat consumption. However, to avoid any risk of toxoplasmosis, thorough cooking of horse meat is recommended.
Detection of Toxoplasma gondii DNA in horse meat from supermarkets in France and performance evaluation of two serological tests.

Science.gov (United States)

Aroussi, Abdelkrim; Vignoles, Philippe; Dalmay, François; Wimel, Laurence; Dardé, Marie-Laure; Mercier, Aurélien; Ajzenberg, Daniel

2015-01-01

In France, some cases of severe toxoplasmosis have been linked to the consumption of horse meat that had been imported from the American continent where atypical strains of Toxoplasma gondii are more common than in Europe. Many seroprevalence studies are presented in the literature but risk assessment of T. gondii infection after horse meat consumption is not possible in the absence of validated serological tests and the unknown correlation between detection of antibodies against T. gondii and presence of tissue cysts. We performed magnetic-capture polymerase chain reaction (MC-PCR) to detect T. gondii DNA in 231 horse meat samples purchased in supermarkets in France and evaluated the performance and level of agreement of the modified agglutination test (MAT) and enzyme-linked immunosorbent assay (ELISA) in the meat juices. The serological tests lacked sensitivity, specificity, and agreement between them, and there was no correlation with the presence of T. gondii DNA in horse meat, raising concerns about the reliability of T. gondii seroprevalence data in horses from the literature. T. gondii DNA was detected in 43% of horse meat samples but the absence of strain isolation in mice following inoculation of more than 100 horse meat samples suggests a low distribution of cysts in skeletal muscles and a low risk of T. gondii infection associated with horse meat consumption. However, to avoid any risk of toxoplasmosis, thorough cooking of horse meat is recommended. © A. Aroussi et al., published by EDP Sciences, 2015.
Within-mat variability in anatoxin-a and homoanatoxin-a production among benthic Phormidium (cyanobacteria) strains.

Science.gov (United States)

Wood, Susanna A; Smith, Francine M J; Heath, Mark W; Palfroy, Thomas; Gaw, Sally; Young, Roger G; Ryan, Ken G

2012-10-01

Benthic Phormidium mats can contain high concentrations of the neurotoxins anatoxin-a and homoanatoxin-a. However, little is known about the co-occurrence of anatoxin-producing and non-anatoxin-producing strains within mats. There is also no data on variation in anatoxin content among toxic genotypes isolated from the same mat. In this study, 30 Phormidium strains were isolated from 1 cm(2) sections of Phormidium-dominated mats collected from three different sites. Strains were grown to stationary phase and their anatoxin-a, homoanatoxin-a, dihydroanatoxin-a and dihydrohomoanatoxin-a concentrations determined using liquid chromatography-mass spectrometry. Each strain was characterized using morphological and molecular (16S rRNA gene sequences) techniques. Eighteen strains produced anatoxin-a, dihydroanatoxin-a or homoanatoxin-a. Strains isolated from each mat either all produced toxins, or were a mixture of anatoxin and non-anatoxin-producing genotypes. Based on morphology these genotypes could not be separated. The 16S rRNA gene sequence comparisons showed a difference of at least 17 nucleotides among anatoxin and non-anatoxin-producing strains and these formed two separate sub-clades during phylogenetic analysis. The total anatoxin concentration among toxic strains varied from 2.21 to 211.88 mg kg(-1) (freeze dried weight), representing a 100 fold variation in toxin content. These data indicate that both the relative abundance of anatoxin and non-anatoxin-producing genotypes, and variations in anatoxin producing capability, can influence the overall toxin concentration of benthic Phormidium mat samples.
Unravelling core microbial metabolisms in the hypersaline microbial mats of Shark Bay using high-throughput metagenomics

Energy Technology Data Exchange (ETDEWEB)

Ruvindy, Rendy; White III, Richard Allen; Neilan, Brett Anthony; Burns, Brendan Paul

2015-05-29

Modern microbial mats are potential analogues of some of Earth’s earliest ecosystems. Excellent examples can be found in Shark Bay, Australia, with mats of various morphologies. To further our understanding of the functional genetic potential of these complex microbial ecosystems, we conducted for the first time shotgun metagenomic analyses. We assembled metagenomic nextgeneration sequencing data to classify the taxonomic and metabolic potential across diverse morphologies of marine mats in Shark Bay. The microbial community across taxonomic classifications using protein-coding and small subunit rRNA genes directly extracted from the metagenomes suggests that three phyla Proteobacteria, Cyanobacteria and Bacteriodetes dominate all marine mats. However, the microbial community structure between Shark Bay and Highbourne Cay (Bahamas) marine systems appears to be distinct from each other. The metabolic potential (based on SEED subsystem classifications) of the Shark Bay and Highbourne Cay microbial communities were also distinct. Shark Bay metagenomes have a metabolic pathway profile consisting of both heterotrophic and photosynthetic pathways, whereas Highbourne Cay appears to be dominated almost exclusively by photosynthetic pathways. Alternative non-rubisco-based carbon metabolism including reductive TCA cycle and 3-hydroxypropionate/4-hydroxybutyrate pathways is highly represented in Shark Bay metagenomes while not represented in Highbourne Cay microbial mats or any other mat forming ecosystems investigated to date. Potentially novel aspects of nitrogen cycling were also observed, as well as putative heavy metal cycling (arsenic, mercury, copper and cadmium). Finally, archaea are highly represented in Shark Bay and may have critical roles in overall ecosystem function in these modern microbial mats.
Sewage, green algal mats anchored by lugworms, and the effects on Turbellaria and small Polychaeta

Science.gov (United States)

Reise, Karsten

1983-06-01

On sandy tidal flats at the Island of Sylt (North Sea) ephemeral mats of green algae covered wide areas in the vicinity of sewage outflows. Algae became anchored in the feeding funnels of lugworms ( Arenicola marina) and thus were able to resist displacement by tidal currents. Below the algal mats anoxic conditions extend to the sediment surface. After about one month a rough sea removed all algae. Polychaetes endured this short-term environmental deterioration, while the more sensitive Turbellaria decreased in abundance and species richness. Diatom-feeders were affected most, predators to a medium extent, and bacteria-feeders the least affected. Rare and very abundant species were more affected than moderately abundant ones. None of the turbellarian species increased in abundance and none colonized the algal mats above the sediment. In a semicontrolled experiment with daily hand-removal of drift algae from a 100-m2 plot within an extensive field of algal mats, this cleaned "island" served as a refuge to Turbellaria escaping from their algal covered habitat. Here abundance doubled relative to initial conditions and was 5-times higher than below algal mats.

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

Science.gov (United States)

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 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.
115 THE SENSITIVITY OF DIAZO TEST IN THE DIAGNOSIS OF ...

African Journals Online (AJOL)

Salmonella typhi was the predominant serotype causing typhoid/paratyphoid fevers, followed by S. paratypi A; S. paratyphi C and S. paratyphi B respectively. Although. Diazo test does not appear to be reliable, it could still be useful alongside with Widal agglutination test in endemic rural or urban areas where electricity and ...
LEPINOCONUS CHIOCCHINII GEN. N., N. SP., A CONICAL AGGLUTINATED FORAMINIFERA FROM THE UPPER CRETACEOUS OF ITALY

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ERZIKA CRUZ-ABAD

2017-04-01

Full Text Available A new conical agglutinated foraminifer, Lepinoconus chiocchinii gen n., n. sp. from the lower Campanian shallow-water platform deposits of the Lepini Mountains (central Apennines, Italy, is described. It has a pseudo-keriothecal wall structure, uniserial arrangement of the adult chambers and multiple apertures. The exoskeleton is constituted by beams (main and intercalary continuous from one chamber to the next, while the endoskeleton bears pillars. The new taxon is included in the Coskinolinidae family. Lepinoconus chiocchinii gen. n., n. sp. is known from southern Italy, Greece and Albania.
MATS and LaSpec: High-precision experiments using ion traps and lasers at FAIR

Science.gov (United States)

Rodríguez, D.; Blaum, K.; Nörtershäuser, W.; Ahammed, M.; Algora, A.; Audi, G.; Äystö, J.; Beck, D.; Bender, M.; Billowes, J.; Block, M.; Böhm, C.; Bollen, G.; Brodeur, M.; Brunner, T.; Bushaw, B. A.; Cakirli, R. B.; Campbell, P.; Cano-Ott, D.; Cortés, G.; Crespo López-Urrutia, J. R.; Das, P.; Dax, A.; de, A.; Delheij, P.; Dickel, T.; Dilling, J.; Eberhardt, K.; Eliseev, S.; Ettenauer, S.; Flanagan, K. T.; Ferrer, R.; García-Ramos, J.-E.; Gartzke, E.; Geissel, H.; George, S.; Geppert, C.; Gómez-Hornillos, M. B.; Gusev, Y.; Habs, D.; Heenen, P.-H.; Heinz, S.; Herfurth, F.; Herlert, A.; Hobein, M.; Huber, G.; Huyse, M.; Jesch, C.; Jokinen, A.; Kester, O.; Ketelaer, J.; Kolhinen, V.; Koudriavtsev, I.; Kowalska, M.; Krämer, J.; Kreim, S.; Krieger, A.; Kühl, T.; Lallena, A. M.; Lapierre, A.; Le Blanc, F.; Litvinov, Y. A.; Lunney, D.; Martínez, T.; Marx, G.; Matos, M.; Minaya-Ramirez, E.; Moore, I.; Nagy, S.; Naimi, S.; Neidherr, D.; Nesterenko, D.; Neyens, G.; Novikov, Y. N.; Petrick, M.; Plaß, W. R.; Popov, A.; Quint, W.; Ray, A.; Reinhard, P.-G.; Repp, J.; Roux, C.; Rubio, B.; Sánchez, R.; Schabinger, B.; Scheidenberger, C.; Schneider, D.; Schuch, R.; Schwarz, S.; Schweikhard, L.; Seliverstov, M.; Solders, A.; Suhonen, M.; Szerypo, J.; Taín, J. L.; Thirolf, P. G.; Ullrich, J.; van Duppen, P.; Vasiliev, A.; Vorobjev, G.; Weber, C.; Wendt, K.; Winkler, M.; Yordanov, D.; Ziegler, F.

2010-05-01

Nuclear ground state properties including mass, charge radii, spins and moments can be determined by applying atomic physics techniques such as Penning-trap based mass spectrometry and laser spectroscopy. The MATS and LaSpec setups at the low-energy beamline at FAIR will allow us to extend the knowledge of these properties further into the region far from stability. The mass and its inherent connection with the nuclear binding energy is a fundamental property of a nuclide, a unique “fingerprint”. Thus, precise mass values are important for a variety of applications, ranging from nuclear-structure studies like the investigation of shell closures and the onset of deformation, tests of nuclear mass models and mass formulas, to tests of the weak interaction and of the Standard Model. The required relative accuracy ranges from 10-5 to below 10-8 for radionuclides, which most often have half-lives well below 1 s. Substantial progress in Penning trap mass spectrometry has made this method a prime choice for precision measurements on rare isotopes. The technique has the potential to provide high accuracy and sensitivity even for very short-lived nuclides. Furthermore, ion traps can be used for precision decay studies and offer advantages over existing methods. With MATS (Precision Measurements of very short-lived nuclei using an A_dvanced Trapping System for highly-charged ions) at FAIR we aim to apply several techniques to very short-lived radionuclides: High-accuracy mass measurements, in-trap conversion electron and alpha spectroscopy, and trap-assisted spectroscopy. The experimental setup of MATS is a unique combination of an electron beam ion trap for charge breeding, ion traps for beam preparation, and a high-precision Penning trap system for mass measurements and decay studies. For the mass measurements, MATS offers both a high accuracy and a high sensitivity. A relative mass uncertainty of 10-9 can be reached by employing highly-charged ions and a non
Environmental controls on photosynthetic microbial mat distribution and morphogenesis on a 3.42 Ga clastic-starved platform.

Science.gov (United States)

Tice, Michael M

2009-12-01

Three morphotypes of microbial mats are preserved in rocks deposited in shallow-water facies of the 3.42 Ga Buck Reef chert (BRC). Morphotype alpha consists of fine anastomosing and bifurcating carbonaceous laminations, which loosely drape underlying detrital grains or form silica-filled lenses. Morphotype beta consists of meshes of fine carbonaceous strands intergrown with detrital grains and dark laminations, which loosely drape coarse detrital grains. Morphotype gamma consists of fine, even carbonaceous laminations that tightly drape underlying detrital grains. Preservation of nearly uncompacted mat morphologies and detrital grains deposited during mat growth within a well-characterized sedimentary unit makes quantitative correlation between morphology and paleoenvironment possible. All mats are preserved in the shallowest-water interval of those rocks deposited below normal wave base and above storm wave base. This interval is bounded below by a transgressive lag formed during regional flooding and above by a small condensed section that marks a local relative sea-level maximum. Restriction of all mat morphotypes to the shallowest interval of the storm-active layer in the BRC ocean reinforces previous interpretations that these mats were constructed primarily by photosynthetic organisms. Morphotypes alpha and beta dominate the lower half of this interval and grew during deposition of relatively coarse detrital carbonaceous grains, while morphotype gamma dominates the upper half and grew during deposition of fine detrital carbonaceous grains. The observed mat distribution suggests that either light intensity or, more likely, small variations in ambient current energy acted as a first-order control on mat morphotype distribution. These results demonstrate significant environmental control on biological morphogenetic processes independent of influences from siliciclastic sedimentation.
Nanofiber mat spinal cord dressing-released glutamate impairs blood-spinal cord barrier

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Dorota Sulejczak

2016-12-01

Full Text Available An excessive glutamate level can result in excitotoxic damage and death of central nervous system (CNS cells, and is involved in the pathogenesis of many CNS diseases. It may also be related to a failure of the blood-spinal cord barrier (BSCB. This study was aimed at examining the effects of extended administration of monosodium glutamate on the BSCB and spinal cord cells in adult male Wistar rats. The glutamate was delivered by subarachnoidal application of glutamate-carrying electrospun nanofiber mat dressing at the lumbar enlargement level. Half of the rats with the glutamate-loaded mat application were treated systemically with the histone deacetylase inhibitor valproic acid. A group of intact rats and a rat group with subarachnoidal application of an ‘empty’ (i.e., carrying no glutamate nanofiber mat dressing served as controls. All the rats were euthanized three weeks later and lumbar fragments of their spinal cords were harvested for histological, immunohistochemical and ultrastructural studies. The samples from controls revealed normal parenchyma and BSCB morphology, whereas those from rats with the glutamate-loaded nanofiber mat dressing showed many intraparenchymal microhemorrhages of variable sizes. The capillaries in the vicinity of the glutamate-carrying dressing (in the meninges and white matter alike were edematous and leaky, and their endothelial cells showed degenerative changes: extensive swelling, enhanced vacuolization and the presence of vascular intraluminal projections. However, endothelial tight junctions were generally well preserved. Some endothelial cells were dying by necrosis or apoptosis. The adjacent parenchyma showed astrogliosis with astrocytic hypertrophy and swelling of perivascular astrocytic feet. Neurons in the parenchyma revealed multiple symptoms of degeneration, including, inter alia, perikaryal, dendritic and axonal swelling, and destruction of organelles. All the damage symptoms were slightly less
Phylogenetic Evidence for the Existence of Novel Thermophilic Bacteria in Hot Spring Sulfur-Turf Microbial Mats in Japan

Science.gov (United States)

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
Diagnostic Efficacy of Modified Coagglutination Test in the Diagnosis of Human Brucellosis

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Mohite S.T

2013-07-01

Full Text Available Background: Laboratory help is must for thediagnosis of human brucellosis due to proteanclinical manifestations. As culture is hazardous,time consuming and less sensitive, serologicaltests are preferred for the diagnosis. Aggluti-nation tests like Rose Bengal PlateTest (RBPT, Serum Agglutination tests (SAT,2-Mercaptoethanol test (2-ME that are com-monly employed for the diagnosis either lacksensitivity or specificity. Coombs test andBrucellacapt though are sensitive and specific,workout costly. Therefore, modifiedcoagglutination test was developed and its di-agnostic efficacy was evaluated. Aims and Ob-jectives: To develop modified coagglutinationtest for the diagnosis of human brucellosis andcompare it with Coombs test. Materials andMethods: Serum samples collected from 191brucellosis patients and 100 controls were sub-jected to 2-ME, Coombs test and modifiedcoagglutination test (MCOAG. Blood culturewas performed by Castanedas method in all thepatients. Results: Significant difference in thepositivity rate was seen between MCOAG and2-ME. The results of MCOAG were compa-rable with Coombs test. Conclusions: Modi-fied coagglutination test is a better option toCoombs test for the serodiagnosis of brucel-losis in resource constrained countries as it issensitive, specific and cost effective.
Thermodynamics and phase transformations: the selected works of Mats Hillert

International Nuclear Information System (INIS)

Agren, J.; Brechet, Y.; Hutchinson, Ch.; Purdy, G.

2006-01-01

For over half a century, Mats Hillert has contributed greatly to the science of materials. He is widely known and respected as an innovator and an educator, a scientist with an enormous breadth of interest and depth of insight. In acknowledgment of his many contributions, a conference was held in Stockholm in December 2004 to mark his eightieth birthday. This volume was conceived prior to, and publicly announced during the conference. The difficult choice of twenty-four papers from a publication list of more than three hundred was carried out in consultation with Mats. He also suggested or approved the scientists who would be invited to write a brief introduction to each paper. A brief reading of the topics of the selected papers and their introductions reveals something of their range and depth. Several early selections (for example, those on 'The Role of Interfacial Energy during Solid State Phase Transformations', and 'A Solid-Solution Model for Inhomogeneous Systems') contained seminal material that established Mats as a leading figure in the study of phase transformations in solids. Others established his presence in the areas of solidification and computational thermodynamics. A review of his full publication list shows that he has consistently built upon those early foundational papers, and maintained a dominant position in those fields. Although many of his contributions have been of a theoretical nature, he has always maintained a close contact with experiment, and indeed, he has designed numerous critical experiments. This volume represents a judicious sampling of Mats Hillert's extensive body of work; it is necessarily incomplete, but it is hoped and expected that it will prove useful to students of materials science and engineering at all levels, and that it will inspire the further study and appreciation of his many contributions. (authors)
Microbial mat-induced sedimentary structures in siliciclastic sediments

Indian Academy of Sciences (India)

This paper addresses macroscopic signatures of microbial mat-related structures within the. 1.6Ga-old Chorhat Sandstone ... Sandstone differentiated in facies superposed one over the other and their respective structural assemblages (b). may be ..... within the classification of primary sedimentary struc- tures; J. Sed. Res.
Lectin-induced agglutination method of urinary exosomes isolation followed by mi-RNA analysis: Application for prostate cancer diagnostic.

Science.gov (United States)

Samsonov, Roman; Shtam, Tatiana; Burdakov, Vladimir; Glotov, Andrey; Tsyrlina, Evgenia; Berstein, Lev; Nosov, Alexander; Evtushenko, Vladimir; Filatov, Michael; Malek, Anastasia

2016-01-01

Prostate cancer is the most common cancer in men. Prostate-specific antigen has, however, insufficient diagnostic specificity. Novel complementary diagnostic approaches are greatly needed. MiRNAs are small regulatory RNAs which play an important role in tumorogenesis and are being investigated as a cancer biomarker. In addition to their intracellular regulatory functions, miRNAs are secreted into the extracellular space and can be found in various body fluids, including urine. The stability of extracellular miRNAs is defined by association with proteins, lipoprotein particles, and membrane vesicles. Among the known forms of miRNA packaging, tumour-derived exosome-enclosed miRNAs is thought to reflect the vital activity of cancer cells. The assessment of the exosomal fraction of urinary miRNA may present a new and highly specific method for prostate cancer diagnostics; however, this is challenged by the absence of reliable and inexpensive methods for isolation of exosomes. Prostate cancer (PC) cell lines and urine samples collected from 35 PC patients and 35 healthy donors were used in the study. Lectins, phytohemagglutinin, and concanavalin A were used to induce agglutination of exosomes. The efficiency of isolation process was evaluated by AFM and DLS assays. The protein content of isolated exosomes was analysed by western blotting. Exosomal RNA was assayed by automated electrophoresis and expression level of selected miRNAs was evaluated by RT-qPCR. The diagnostic potency of the urinary exosomal miRNA assessment was estimated by the ROC method. The formation of multi-vesicular agglutinates in urine can be induced by incubation with lectin at a final concentration of 2 mg/ml. These agglutinates contain urinary exosomes and may be pelleted by centrifugation with a relatively low G-force. The analysis of PC-related miRNA in urinary exosomes revealed significant up-regulation of miR-574-3p, miR-141-5p, and miR-21-5p associated with PC. Lectin-induced aggregation is a
Charpy V, an application in Mat lab; Charpy V, una aplicacion en Matlab

Energy Technology Data Exchange (ETDEWEB)

Castillo M, J.A.; Torres V, M. [ININ, 52045 Ocoyoacac, Estado de Mexico (Mexico)

2003-07-01

The obtained results with the system Charpy V{sub V}1 designed in Mat lab for the estimate of parameters of three mathematical models are shown. The adjustment of data is used to determine the fracture energy, the lateral expansion and the percentage of ductility of steels coming from the reactor vessels of Laguna Verde, Veracruz. The data come from test tubes type Charpy V of irradiated material and not irradiated. To verify our results they were compared with those obtained by General Electric of data coming from the Laguna Verde nuclear power plant. (Author)
Rapid serum agglutination and agar gel immunodiffusion tests associated to clinical signs in rams experimentally infected with Brucella ovis Teste de soro aglutinação rápida e do teste de imunodifusão em gel de ágar associados aos sinais clínicos em carneiros infectados experimentalmente com Brucella ovis

Directory of Open Access Journals (Sweden)

Cristiane Nakada Nozaki

2011-08-01

Full Text Available The purpose of this study was to evaluate the agar gel immunodiffusion and the rapid serum agglutination tests associated to clinical signs in rams experimentally infected with Brucella ovis. The serological profile during the 12 months of infection showed a large fluctuation of antibodies that favors the failure in the diagnostic. The evaluation of tests after the experimental infection allowed to suggest that none of the tests were able to detect the infection throughout the period of study. The study reinforces the importance of considering the clinical signs to support the diagnosis of Brucella ovis infection in rams.O objetivo deste estudo foi avaliar o uso do teste de imunodifusão em gel de ágar e o teste sorológico de aglutinação rápida comparados aos sinais clínicos em carneiros infectados experimentalmente com Brucella ovis para o diagnóstico confirmatório da brucelose ovina. O perfil sorológico durante os 12 meses pós-infecção mostrou flutuação da resposta por anticorpos, que favorece a falha no diagnóstico. A avaliação dos testes indicou que nenhum dos testes foi capaz de detectar a infecção durante todo o período de estudo. O estudo ressalta a importância de considerar os sinais clínicos para apoiar o diagnóstico confirmatório da infecção por Brucella ovis em carneiros.
An unusual presentation of brucellosis, involving multiple organ systems, with low agglutinating titers: a case report

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Khorvash Farzin

2007-07-01

Full Text Available Abstract Background Brucellosis is a multi-system disease that may present with a broad spectrum of clinical manifestations. While hepatic involvement in brucellosis is not rare, it may rarely involve the kidney or display with cardiac manifestations. Central nervous system involvement in brucellosis sometimes can cause demyelinating syndromes. Here we present a case of brucella hepatitis, myocarditis, acute disseminated encephalomyelitis, and renal failure. Case presentation A 26-year-old man presented with fever, ataxia, and dysarthria. He was a shepherd and gave a history of low grade fever, chilly sensation, cold sweating, loss of appetite, arthralgia and 10 Kg weight loss during the previous 3 months. He had a body temperature of 39°C at the time of admission. On laboratory tests he had elevated level of liver enzymes, blood urea nitrogen, Creatinine, Creatine phosphokinase (MB, and moderate proteinuria. He also had abnormal echocardiography and brain MRI. Enzyme-linked immunosorbent assay for IgG and IgM was negative. Standard tube agglutination test (STAT and 2-mercaptoethanol (2-ME titers were 1:80 and 1:40 respectively. Finally he was diagnosed with brucellosis by positive blood culture and the polymerase chain reaction for Brucella mellitensis. Conclusion In endemic areas clinicians should consider brucellosis in any unusual presentation involving multiple organ systems, even if serology is inconclusive. In endemic areas low STAT and 2-ME titers should be considered as an indication of brucellosis and in these cases additional testing is recommended to rule out brucellosis.
Effects of Elevated Carbon Dioxide and Salinity on the Microbial Diversity in Lithifying Microbial Mats

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Steven R. Ahrendt

2014-03-01

Full Text Available Atmospheric levels of carbon dioxide (CO2 are rising at an accelerated rate resulting in changes in the pH and carbonate chemistry of the world’s oceans. However, there is uncertainty regarding the impact these changing environmental conditions have on carbonate-depositing microbial communities. Here, we examine the effects of elevated CO2, three times that of current atmospheric levels, on the microbial diversity associated with lithifying microbial mats. Lithifying microbial mats are complex ecosystems that facilitate the trapping and binding of sediments, and/or the precipitation of calcium carbonate into organosedimentary structures known as microbialites. To examine the impact of rising CO2 and resulting shifts in pH on lithifying microbial mats, we constructed growth chambers that could continually manipulate and monitor the mat environment. The microbial diversity of the various treatments was compared using 16S rRNA gene pyrosequencing. The results indicated that elevated CO2 levels during the six month exposure did not profoundly alter the microbial diversity, community structure, or carbonate precipitation in the microbial mats; however some key taxa, such as the sulfate-reducing bacteria Deltasulfobacterales, were enriched. These results suggest that some carbonate depositing ecosystems, such as the microbialites, may be more resilient to anthropogenic-induced environmental change than previously thought.
Seroprevalence of Neospora infection in horses and donkeys in Hamedan province, Western Iran

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Jamal Gharekhani

2013-06-01

Full Text Available Aim: The aim of the present study was to determine the seroprevalence of Neospora infection in horses and donkeys in Hamedan province, Western Iran.Materials and Methods:In cross-sectional study, Blood samples (n=220 were collected from 120 horses and 100 donkeys in 2012 year. All sera were screened for Neosporausing Neosporamodified direct agglutination test (N-MAT. Results:Antibodies to Neospora infection in horses and donkeys were reported in 40.8% and 52%, respectively. There was not significant correlation demonstrated between infection rates in different age groups and genders.Conclusion: The current study is the first report of Neospora infection in donkeys from Iran. Further investigations and designing control strategies is recommended
A Constitutively Mannose-Sensitive Agglutinating Salmonella enterica subsp. enterica Serovar Typhimurium Strain, Carrying a Transposon in the Fimbrial Usher Gene stbC, Exhibits Multidrug Resistance and Flagellated Phenotypes

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Kuan-Hsun Wu

2012-01-01

Full Text Available Static broth culture favors Salmonella enterica subsp. enterica serovar Typhimurium to produce type 1 fimbriae, while solid agar inhibits its expression. A transposon inserted in stbC, which would encode an usher for Stb fimbriae of a non-flagellar Salmonella enterica subsp. enterica serovar Typhimurium LB5010 strain, conferred it to agglutinate yeast cells on both cultures. RT-PCR revealed that the expression of the fimbrial subunit gene fimA, and fimZ, a regulatory gene of fimA, were both increased in the stbC mutant when grown on LB agar; fimW, a repressor gene of fimA, exhibited lower expression. Flagella were observed in the stbC mutant and this phenotype was correlated with the motile phenotype. Microarray data and RT-PCR indicated that the expression of three genes, motA, motB, and cheM, was enhanced in the stbC mutant. The stbC mutant was resistant to several antibiotics, consistent with the finding that expression of yhcQ and ramA was enhanced. A complementation test revealed that transforming a recombinant plasmid possessing the stbC restored the mannose-sensitive agglutination phenotype to the stbC mutant much as that in the parental Salmonella enterica subsp. enterica serovar Typhimurium LB5010 strain, indicating the possibility of an interplay of different fimbrial systems in coordinating their expression.
The effect Mat Pilates practice on muscle mass in elderly women

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Leliz Cristina Sampaio Queiroz

2016-01-01

Full Text Available Objective: to verify that the Mat Pilates practice increases muscle mass in elderly women. Methods: quasi-experimental study with primary data collection and with a convenience sample. The muscle mass of 43 elderly was evaluated for 11 weeks, by calculating the arm muscle area, before and after the intervention. Results:statistically significant difference was observed (p<0.002 between the average value of the arm muscle area, before (35.56cm2 and after the exercises (42.72cm2. Conclusion: mat Pilates program generates positive effect on increasing the muscle mass of elderly.
Contradicción, coherencia y compromiso: Matías Usero Torrente

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Tezanos Gandarillas, Marisa

2001-06-01

Full Text Available The current article studies the figure of Matías Usero Torrente. His thought is considered by the author as a preceding of the principals ideas that emphasized about the relations between State and Society during the sixties in Spain.

En el presente artículo se analiza la figura de Matías Usero Torrente. Su pensamiento es considerado por la autora del estudio como antecesor de las principales ideas que sobre las relaciones de la Iglesia con el Estado y la Sociedad cristalizaron en la década de los 60 en España.
Distribution and Composition of Thiotrophic Mats in the Hypoxic Zone of the Black Sea (150-170 m Water Depth, Crimea Margin).

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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 km(2) 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

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

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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…
Bacterial and archaeal diversity in two hot spring microbial mats from the geothermal region of Tengchong, China.

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Pagaling, Eulyn; Grant, William D; Cowan, Don A; Jones, Brian E; Ma, Yanhe; Ventosa, Antonio; Heaphy, Shaun

2012-07-01

We investigated the bacterial and archaeal diversity in two hot spring microbial mats from the geothermal region of Tengchong in the Yunnan Province, China, using direct molecular analyses. The Langpu (LP) laminated mat was found by the side of a boiling pool with temperature of 60-65 °C and a pH of 8.5, while the Tengchong (TC) streamer mat consisted of white streamers in a slightly acidic (pH 6.5) hot pool outflow with a temperature of 72 °C. Four 16S rRNA gene clone libraries were constructed and restriction enzyme analysis of the inserts was used to identify unique sequences and clone frequencies. From almost 200 clones screened, 55 unique sequences were retrieved. Phylogenetic analysis showed that the LP mat consisted of a diverse bacterial population [Cyanobacteria, Chloroflexi, Chlorobia, Nitrospirae, 'Deinococcus-Thermus', Proteobacteria (alpha, beta and delta subdivisions), Firmicutes, Bacteroidetes and Actinobacteria], while the archaeal population was dominated by methanogenic Euryarchaeota and Crenarchaeota. In contrast, the TC streamer mat consisted of a bacterial population dominated by Aquificae, while the archaeal population also contained Korarchaeota as well as Crenarchaeota and methanogenic Euryarchaeota. These mats harboured clone sequences affiliated to unidentified lineages, suggesting that they are a potential source for discovering novel bacteria and archaea.
Design of a smart textile mat to study pressure distribution on multiple foam material configurations

NARCIS (Netherlands)

Donselaar, van R.; Chen, W.

2011-01-01

In this paper, we present a design of a smart textile pressure mat to study the pressure distribution with multiple foam material configurations for neonatal monitoring at Neonatal Intensive Care Units (NICU). A smart textile mat with 64 pressure sensors has been developed including software at the
Matting of Hair Due to Halo-egg Shampoo

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Z M Mani

1983-01-01

Full Text Available A case of hair matting in an 18 year old female is reported. The hair got densely entangled immediately after washing the hair with ′Halo Egg′ shampoo. The hair was disentangled completely after prolonged dipping of the hair in arachis oil frr 5 days.
Diversity of nitrogen-fixing bacteria in cyanobacterial mats

NARCIS (Netherlands)

Severin, I.; Acinas, S.G.; Stal, L.J.

2010-01-01

The structure of the microbial community and the diversity of the functional gene for dinitrogenase reductase and its transcripts were investigated by analyzing >1400 16S rRNA gene and nifH sequences from two microbial mats situated in the intertidal zone of the Dutch barrier island Schiermonnikoog.
HiRadMat at CERN/SPS - A dedicated facility providing high intensity beam pulses to material samples

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Charitonidis, N; Efthymiopoulos, I

2014-01-01

HiRadMat (High Radiation to Materials), constructed in 2011, 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, high power beam targets, collimators…) can be tested. The facility uses a 440 GeV proton beam extracted from the CERN SPS with a pulse length of up to 7.2 us, and with a maximum pulse energy of 3.4 MJ (3xE13 proton/pulse). In addition to protons, ion beams with energy of 440 GeV/charge and total pulse energy of 21 kJ can be provided. The beam parameters can be tuned to match the needs of each experiment. HiRadMat is not an irradiation facility where large doses on equipment can be accumulated. It is rather a test area designed to perform single pulse experiments to evaluate the effect of high‐intensity pulsed beams on materials or accelerator component assemblies in a controlled environment. The fa‐ cility is designed for a maximum of 1E16 protons per year, dist...
The Use of Maltodextrin Matrices to Control the Release of Minerals from Fortified Maté

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Miguel E. Schmalko

2012-04-01

Full Text Available Normal 0 false false false EN-US X-NONE X-NONE The aim of this research was to study the sensorial acceptance of a fortified food containing different minerals (calcium, magnesium and iron and to determine the actual quantities present (bioaccessibility when extracted in maté. A sensorial analysis was performed to compare sensorial quality of fortified and non-fortified maté. Although panelists identified differences between the fortified and non-fortified maté, only 3% of them commented on an unpleasant flavor. Sequential extraction assays were performed simulating maté consumption under laboratory conditions. Profile concentration diminished sharply after the second extraction. Magnesium was found to be completely extracted in the first 500 mL. Calcium and Iron were extracted in a very low percentage (29% and 25%, respectively. The outlet rate of the minerals was fitted to two models, and a good fitness (p < 0:001 in all cases was obtained.
Marine Microbial Mats and the Search for Evidence of Life in Deep Time and Space

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Des Marais, David J.

2011-01-01

Cyanobacterial mats in extensive seawater evaporation ponds at Guerrero Negro, Baja California, Mexico, have been excellent subjects for microbial ecology research. The studies reviewed here have documented the steep and rapidly changing environmental gradients experienced by mat microorganisms and the very high rates of biogeochemical processes that they maintained. Recent genetic studies have revealed an enormous diversity of bacteria as well as the spatial distribution of Bacteria, Archaea and Eukarya. These findings, together with emerging insights into the intimate interactions between these diverse populations, have contributed substantially to our understanding of the origins, environmental impacts, and biosignatures of photosynthetic microbial mats. The biosignatures (preservable cells, sedimentary fabrics, organic compounds, minerals, stable isotope patterns, etc.) potentially can serve as indicators of past life on early Earth. They also can inform our search for evidence of any life on Mars. Mars exploration has revealed evidence of evaporite deposits and thermal spring deposits; similar deposits on Earth once hosted ancient microbial mat ecosystems.
Validity of Hip-worn Inertial Measurement Unit Compared to Jump Mat for Jump Height Measurement in Adolescents.

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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.
Toxoplasmosis in Tammar wallabies (Macropus eugenii) in the Budapest Zoo and Botanical Garden (2006-2010).

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Sós, Endre; Szigeti, Alexandra; Fok, Eva; Molnár, Viktor; Erdélyi, Károly; Perge, Edina; Biksi, Imre; Gál, János

2012-09-01

Smaller macropodid species (commonly referred to as wallabies) are extremely susceptible to toxoplasmosis: in most cases, infection with Toxoplasma gondii leads to death within a short time. Between June 2006 and July 2010, T. gondii was detected by immunohistochemical examination in six Tammar wallabies (Macropus eugenii) that died in the Budapest Zoo and Botanical Garden; in another four specimens histopathology revealed T. gondii-like organisms (which could not be differentiated from Neospora caninum solely by morphology), and in another 11 animals toxoplasmosis as the possible cause of death could not be excluded. The current zoo population of 12 Tammar wallabies was tested for T. gondii IgG antibodies by the modified agglutination test (MAT), with negative results. We suppose that most of the deaths were due to acute toxoplasmosis resulting from a recent infection.
Impacts of Canada's minimum age for tobacco sales (MATS) laws on youth smoking behaviour, 2000-2014.

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Callaghan, Russell Clarence; Sanches, Marcos; Gatley, Jodi; Cunningham, James K; Chaiton, Michael Oliver; Schwartz, Robert; Bondy, Susan; Benny, Claire

2018-01-13

Recently, the US Institute of Medicine has proposed that raising the minimum age for tobacco purchasing/sales to 21 years would likely lead to reductions in smoking behavior among young people. Surprisingly few studies, however, have assessed the potential impacts of minimum-age tobacco restrictions on youth smoking. To estimate the impacts of Canadian minimum age for tobacco sales (MATS) laws on youth smoking behaviour. A regression-discontinuity design, using seven merged cycles of the Canadian Community Health Survey, 2000-2014. Survey respondents aged 14-22 years (n=98 320). Current Canadian MATS laws are 18 years in Alberta, Saskatchewan, Manitoba, Quebec, the Yukon and Northwest Territories, and 19 years of age in the rest of the country. Current, occasional and daily smoking status; smoking frequency and intensity; and average monthly cigarette consumption. In comparison to age groups slightly younger than the MATS, those just older had significant and abrupt increases immediately after the MATS in the prevalence of current smokers (absolute increase: 2.71%; 95% CI 0.70% to 4.80%; P=0.009) and daily smokers (absolute increase: 2.43%; 95% CI 0.74% to 4.12%; P=0.005). Average past-month cigarette consumption within age groups increased immediately following the MATS by 18% (95% CI 3% to 39%; P=0.02). There was no evidence of significant increases in smoking intensity for daily or occasional smokers after release from MATS restrictions. The study provides relevant evidence supporting the effectiveness of Canadian MATS laws for limiting smoking among tobacco-restricted youth. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.
Preservation in microbial mats: mineralization by a talc-like phase of a fish embedded in a microbial sarcophagus

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Iniesto, Miguel; Zeyen, Nina; López-Archilla, Ana; Bernard, Sylvain; Buscalioni, Ángela; Guerrero, M. Carmen; Benzerara, Karim

2015-09-01

Microbial mats have been repeatedly suggested to promote early fossilization of macroorganisms. Yet, experimental simulations of this process remain scarce. Here, we report results of 5 year-long experiments performed onfish carcasses to document the influence of microbial mats on mineral precipitation during early fossilization. Carcasses were initially placed on top of microbial mats. After two weeks, fishes became coated by the mats forming a compact sarcophagus, which modified the microenvironment close to the corpses. Our results showed that these conditions favoured the precipitation of a poorly crystalline silicate phase rich in magnesium. This talc-like mineral phase has been detected in three different locations within the carcasses placed in microbial mats for more than 4 years: 1) within inner tissues, colonized by several bacillary cells; 2) at the surface of bones of the upper face of the corpse buried in the mat; and 3) at the surface of several bones such as the dorsal fin which appeared to be gradually replaced by the Mg-silicate phase. This mineral phase has been previously shown to promote bacteria fossilization. Here we provide first experimental evidence that such Mg-rich phase can also be involved in exceptional preservation of animals.
Serological Evidence of Exposure to Leptospira spp. in Veterinary Students and Other University Students in Trinidad and Tobago

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Ambrose James

2013-01-01

Full Text Available The study compared the serological evidence of leptospirosis in 212 students in four schools (veterinary, dental, advanced nursing education and pharmacy of the University of the West Indies (UWI, by testing for IgG immunoglobulins to Leptospira spp. using the enzyme-linked immunosorbent assay (ELISA and the microscopic agglutination test (MAT. Overall, of 212 students tested by the ELISA, 12 (5.7% and 31 (14.6% were positive and borderline, respectively. Amongst the 113 veterinary students 11 (9.7% and 19 (16.8% were seropositive and borderline respectively compared with nonveterinary students with corresponding values of 1 (1.0% and 12 (12.1%. The frequency of serological evidence of leptospirosis by the ELISA was statistically significantly (; higher in veterinary students, 26.5% (30 of 113 than in nonveterinary students, 13.1% (13 of 99. By the MAT, the seropositivity for leptospirosis was similar for veterinary students, 7.1% (8 of 113 and nonveterinary students, 7.1% (7 of 99. For veterinary students, the prevalent infecting serovar was Icterohaemorrhagiae Copenhageni while amongst nonveterinary students, the prevalent serovar was Australis Rachmati. Being a veterinary student was the only risk factor that was significantly associated with Leptospira infection indicating that veterinary students need to be cognizant and to practise preventive measures for leptospirosis.
Early diagnosis of leptospirosis

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Andrea Babic-Erceg

2014-06-01

Full Text Available A 25-years old man from Zagreb, Croatia, was admitted to the University Hospital for Infectious Diseases four days after the onset of symptoms such as fever, intense pain in the calves and anuria. The patient owned a rabbit and, before the onset of the disease, repaired some rubber pipes damaged by rodents. At admission, he had a severe clinical picture with fever, hypotension, jaundice, immobility, and pain in leg muscles. Treatment with ceftriaxone was initiated in combination with volume restitution. Renal failure soon ensued. Consequently continuous venovenous hemodiaphiltration therapy was performed. Due to acute respiratory distress syndrome, the patient was mechanically ventilated. The patient’s condition gradually improved and he recovered fully from multi-organ failure. Diagnosis was confirmed by a microscopic agglutination test (MAT covering 15 leptospira serovars and real-time polymerase-chain reaction (PCR. The first serum sample taken on day 6 tested negative for leptospira, while PCR showed positive results for leptospiral DNA. The second serum sample taken on day 13 tested positive for serovar Canicola serogroup Canicola, serovar Patoc, serovar Grippotyphosa serogroup Grippotyphosa and serovar Tarassovi serogroup Tarassovi (titre 4000, 4000, 1000 and 2000, respectively, while PCR was negative. This report highlights the benefits of combining MAT and PCR methods in early diagnosis of leptospirosis.
Mechanical and electro-rheological properties of electrospun poly(vinyl alcohol) nanofibre mats filled with carbon black nanoparticles

International Nuclear Information System (INIS)

Chuangchote, Surawut; Sirivat, Anuvat; Supaphol, Pitt

2007-01-01

The present contribution reports, for the first time, the mechanical and electro-rheological properties of electrospun poly(vinyl alcohol) (PVA) nanofibre mats with or without the incorporation of carbon black (CB) nanoparticles. The effects of sonication and the addition of CB on morphological appearance, average diameter of the as-spun fibre mats, and that of the individual fibres, were thoroughly investigated. Incorporation of CB (1-10% based on the weight of PVA) in 10% w/v PVA solution did not affect the morphology and average diameter of the obtained fibres (∼160 nm), but it affected both the mechanical and the electro-rheological properties of the as-spun PVA/CB fibre mats, in which the mats became more rigid with the addition and increasing amount of CB
Genetic and mechanistic evaluation for the mixed-field agglutination in B3 blood type with IVS3+5G>A ABO gene mutation.

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Ding-Ping Chen

Full Text Available BACKGROUND: The ABO blood type B(3 is the most common B subtype in the Chinese population with a frequency of 1/900. Although IVS3+5G>A (rs55852701 mutation of B gene has been shown to associate with the development of B(3 blood type, genetic and mechanistic evaluation for the unique mixed-field agglutination phenotype has not yet been completely addressed. METHODOLOGY/PRINCIPAL FINDINGS: In this study, we analyzed 16 cases of confirmed B(3 individuals and found that IVS3+5G>A attributes to all cases of B(3. RT-PCR analyses revealed the presence of at least 7 types of aberrant B(3 splicing transcripts with most of the transcripts causing early termination and producing non-functional protein during translation. The splicing transcript without exon 3 that was predicted to generate functional B(3 glycosyltransferase lacking 19 amino acids at the N-terminal segment constituted only 0.9% of the splicing transcripts. Expression of the B(3 cDNA with exon 3 deletion in the K562 erythroleukemia cells revealed that the B(3 glycosyltransferase had only 40% of B(1 activity in converting H antigen to B antigen. Notably, the typical mixed-field agglutination of B(3-RBCs can be mimicked by adding anti-B antibody to the K562-B(3 cells. CONCLUSIONS/SIGNIFICANCE: This study thereby demonstrates that both aberrant splicing of B transcripts and the reduced B(3 glycosyltransferase activity contribute to weak B expression and the mixed-field agglutination of B(3, adding to the complexity for the regulatory mechanisms of ABO gene expression.
[The effects of 16-weeks pilates mat program on anthropometric variables and body composition in active adult women after a short detraining period].

Science.gov (United States)

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.
The effects of Mat Pilates and Reformer Pilates in patients with Multiple Sclerosis: A randomized controlled study.

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Bulguroglu, I; Guclu-Gunduz, A; Yazici, G; Ozkul, C; Irkec, C; Nazliel, B; Batur-Caglayan, H Z

2017-01-01

Pilates is an exercise method which increases strength and endurance of core muscles and improves flexibility, dynamic postural control and balance. To analyze and compare the effects of Mat and Reformer Pilates methods in Patients with Multiple Sclerosis (MS). Thirty-eight patients with MS were included in the study. Participants were randomly divided into 3 groups as Mat Pilates, Reformer Pilates and control groups. The subjects in the Pilates groups did Mat or Reformer Pilates for 8 weeks, 2 days a week. The control group did breathing and relaxation exercises at home. Balance, functional mobility, core stability, fatigue severity and quality of life were evaluated. Balance, functional mobility, core stability, fatigue severity and quality of life improved after Pilates in Mat and Reformer Pilates groups (p 0.05). When the gain obtained in the Pilates groups is compared, it has been observed that progress has been more in trunk flexor muscle strength in the Reformer Pilates group (p 0.05). As a result, patients with MS have seen similar benefits in Reformer Pilates and Mat Pilates methods.
Earth's Earliest Ecosystems in the C: The Use of Microbial Mats to Demonstrate General Principles of Scientific Inquiry and Microbial Ecology

Science.gov (United States)

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.
Bagging system, soil stabilization mat, and tent frame for a lunar base

Science.gov (United States)

1990-01-01

Georgia Tech's School of Textile and Fiber Engineering and School of Mechanical Engineering participated in four cooperative design efforts this year. Each of two interdisciplinary teams designed a system consisting of a lunar regolith bag and an apparatus for filling this bag. The third group designed a mat for stabilization of lunar soil during takeoff and landing, and a method for packaging and deploying this mat. Finally, the fourth group designed a sunlight diffusing tent to be used as a lunar worksite. Summaries of these projects are given.

Experimental weed control of Najas marina ssp. intermedia and Elodea nuttallii in lakes using biodegradable jute matting

Directory of Open Access Journals (Sweden)

Markus A. Hoffmann

2013-10-01

Full Text Available The use of jute matting in managing the invasive aquatic macrophyte species Elodea nuttallii (Planch. H. St. John and Najas marina ssp. intermedia (Wolfg. ex Gorski Casper (Najas intermedia was studied in laboratory experiments and field trials. Four German lakes with predominant population of Najas intermedia or Elodea nuttalli were chosen for the experiment and areas between 150 and 300 m² were covered with jute textile. The effect of the matting on the growth of invasive and non-invasive macrophytes was determined through comparison with control transects. Biodegradable jute matting successfully suppressed the invasive macrophyte Najas intermedia and significantly reduced the growth of Elodea nuttalli in lakes. The results indicate that the capability of the matting to inhibit the growth of Elodea nuttallii and Najas intermedia depends on the mesh size of the jute weaving and that environmental conditions can affect its efficiency. Various indigenous species like Charales or Potamogeton pusillus L. were able to grow through the jute fabric and populate the treated areas. Until the end of the vegetation period, none of the invasive species were able to penetrate the covering and establish a stable population; in fact, in the subsequent year the jute matting affected only the spread of Najas intermedia. Jute matting proved to be an easy-to-use and cheap method to control the growth of Elodea nuttallii and Najas intermedia.
Use of filter papers to determine seroprevalence of Toxoplasma gondii among hunted ungulates in remote Peruvian Amazon.

Science.gov (United States)

Aston, Emily J; Mayor, Pedro; Bowman, Dwight D; Mohammed, Hussni O; Liotta, Janice L; Kwok, Oliver; Dubey, J P

2014-04-01

Toxoplasmosis is a zoonosis caused by the protozoan Toxoplasma gondii, and it is found worldwide. To determine whether ungulates are reservoirs of T. gondii in an isolated and remote region of the northeastern Peruvian Amazon, antibodies to T. gondii were determined in 5 species of ungulates by the modified agglutination test (MAT). These animals were hunted by subsistence hunters along the Yavarí-Mirín River, in the northeastern Peruvian Amazon. Blood samples were collected by hunters on filter papers. For determination of T. gondii antibodies, blood was eluted from filter papers, and a titer of 1:25 was considered indicative of exposure to T. gondii. Antibodies to T. gondii were found in 26 (31.0%) peccaries (Pecari tajacu, Tayassu pecari), six (17.1%) brocket deer (Mazama americana, Mazama gouazoubira), and four (40.0%) lowland tapir (Tapirus terrestris). We also introduced a modification to the MAT protocol that allows the extraction of fluid samples from several types of laboratory-grade filter paper, thus enabling researchers to easily adapt their approaches to the materials presented to them.
Use of filter papers to determine seroprevalence of Toxoplasma gondii among hunted ungulates in remote Peruvian Amazon☆

Science.gov (United States)

Aston, Emily J.; Mayor, Pedro; Bowman, Dwight D.; Mohammed, Hussni O.; Liotta, Janice L.; Kwok, Oliver; Dubey, J.P.

2013-01-01

Toxoplasmosis is a zoonosis caused by the protozoan Toxoplasma gondii, and it is found worldwide. To determine whether ungulates are reservoirs of T. gondii in an isolated and remote region of the northeastern Peruvian Amazon, antibodies to T. gondii were determined in 5 species of ungulates by the modified agglutination test (MAT). These animals were hunted by subsistence hunters along the Yavarí-Mirín River, in the northeastern Peruvian Amazon. Blood samples were collected by hunters on filter papers. For determination of T. gondii antibodies, blood was eluted from filter papers, and a titer of 1:25 was considered indicative of exposure to T. gondii. Antibodies to T. gondii were found in 26 (31.0%) peccaries (Pecari tajacu, Tayassu pecari), six (17.1%) brocket deer (Mazama americana, Mazama gouazoubira), and four (40.0%) lowland tapir (Tapirus terrestris). We also introduced a modification to the MAT protocol that allows the extraction of fluid samples from several types of laboratory-grade filter paper, thus enabling researchers to easily adapt their approaches to the materials presented to them. PMID:24918073
Leptospirosis among Hospitalized Febrile Patients in Northern Tanzania

Science.gov (United States)

Biggs, Holly M.; Bui, Duy M.; Galloway, Renee L.; Stoddard, Robyn A.; Shadomy, Sean V.; Morrissey, Anne B.; Bartlett, John A.; Onyango, Jecinta J.; Maro, Venance P.; Kinabo, Grace D.; Saganda, Wilbrod; Crump, John A.

2011-01-01

We enrolled consecutive febrile admissions to two hospitals in Moshi, Tanzania. Confirmed leptospirosis was defined as a ≥ 4-fold increase in microscopic agglutination test (MAT) titer; probable leptospirosis as reciprocal MAT titer ≥ 800; and exposure to pathogenic leptospires as titer ≥ 100. Among 870 patients enrolled in the study, 453 (52.1%) had paired sera available, and 40 (8.8%) of these met the definition for confirmed leptospirosis. Of 832 patients with ≥ 1 serum sample available, 30 (3.6%) had probable leptospirosis and an additional 277 (33.3%) had evidence of exposure to pathogenic leptospires. Among those with leptospirosis the most common clinical diagnoses were malaria in 31 (44.3%) and pneumonia in 18 (25.7%). Leptospirosis was associated with living in a rural area (odds ratio [OR] 3.4, P < 0.001). Among those with confirmed leptospirosis, the predominant reactive serogroups were Mini and Australis. Leptospirosis is a major yet underdiagnosed cause of febrile illness in northern Tanzania, where it appears to be endemic. PMID:21813847
Clinical evaluation of the Byk LIA-mat CA125 II assay: discussion of a reference value.

Science.gov (United States)

Bonfrer, J M; Korse, C M; Verstraeten, R A; van Kamp, G J; Hart, G A; Kenemans, P

1997-03-01

The Byk LIA-mat CA125 II assay was compared with the Centocor IRMA CA125 II. Serum samples studied (n = 1012) were obtained from 652 apparently healthy females, 61 pregnant women, and 299 patients with benign and malignant gynecological tumors. The CA125 II assay value at the 95th percentile of the total healthy group was 29 kU/L for the LIA-mat and 32 kU/L for the Centocor assay. For the LIA-mat assay the 95th percentile was 31 kU/L (Centocor 36 kU/L) for the group 55 years of age. By using ROC curves we found the optimal pretreatment Byk LIA-mat CA125 II value differentiating between benign and malignant ovarian tumors to be 95 kU/L. Pretreatment CA125 values > 1000 kU/L were detected in serum samples of patients with advanced epithelial ovarian cancer.
Physicochemical characterization of different trademarks of compound Yerba Maté and their herbs

OpenAIRE

Scipioni,Griselda Patricia; Ferreyra,Darío Jorge; Schmalko,Miguel Eduardo

2007-01-01

The objectives of this study were to evaluate the physicochemical characteristics of the main herbs used in the mixture of yerba maté with other aromatic herbs and the characterization of the trademarks of compound yerba maté. Moisture, water extract, total ash, acid-insoluble ash and caffeine concentration were determined. Results showed higher values of moisture content, total and aci-insoluble ash and lower water extracts in the herbs. Determinations were carried out in nine trademarks of ...
Distribution and Composition of Thiotrophic Mats in the Hypoxic Zone of the Black Sea (150–170 m Water Depth, Crimea Margin)

Science.gov (United States)

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
Presence of antibodies against Leptospira serovars in Chaetophractus villosus (Mammalia, Dasypodidae), La Pampa province, Argentina.

Science.gov (United States)

Kin, Marta S; Brihuega, Bibiana; Fort, Marcelo; Delgado, Fernando; Bedotti, Daniel; Casanave, Emma B

2015-01-01

Leptospirosis is a zoonosis of worldwide distribution. The aim of this study was to examine the presence of antibodies against 21 Leptospira reactive serovars in Chaetophractus villosus in La Pampa province, Argentina, using the microscopic agglutination test (MAT). Pathologic changes compatible with leptospirosis and in situ detection of the agent by immunohistochemistry were studied in 24 and 3 individuals respectively. Only 35/150 (23.3%) serum samples had antibodies against Leptospira sp. Six percent of the samples reacted with serovar Canicola, 4.7% with serovar Castellonis, 1.3% with serovar Icterohemorrhagieae and 0.7% with serovar Hardjo. Sixteen (10.6%) serum samples agglutinated with Castellonis-Icterohemorrhagiae and Canicola-Castellonis serovars, both with 4.7%, and Canicola-Hardjo and Castellonis-Canicola-Icterohemorrhagiae both with 0.6%. Fourteen animals had variable degrees of lesions, which were more severe in animals with higher serological titers (3200), and Leptospira sp. was detected in 3 animals by immunohistochemistry. These results represent the first record of the presence of Leptospira in C. villosus in La Pampa. Copyright © 2015 Asociación Argentina de Microbiología. Publicado por Elsevier España, S.L.U. All rights reserved.
A Matérn model of the spatial covariance structure of point rain rates

KAUST Repository

Sun, Ying; Bowman, Kenneth P.; Genton, Marc G.; Tokay, Ali

2014-01-01

It is challenging to model a precipitation field due to its intermittent and highly scale-dependent nature. Many models of point rain rates or areal rainfall observations have been proposed and studied for different time scales. Among them, the spectral model based on a stochastic dynamical equation for the instantaneous point rain rate field is attractive, since it naturally leads to a consistent space–time model. In this paper, we note that the spatial covariance structure of the spectral model is equivalent to the well-known Matérn covariance model. Using high-quality rain gauge data, we estimate the parameters of the Matérn model for different time scales and demonstrate that the Matérn model is superior to an exponential model, particularly at short time scales.
A Matérn model of the spatial covariance structure of point rain rates

KAUST Repository

Sun, Ying

2014-07-15

It is challenging to model a precipitation field due to its intermittent and highly scale-dependent nature. Many models of point rain rates or areal rainfall observations have been proposed and studied for different time scales. Among them, the spectral model based on a stochastic dynamical equation for the instantaneous point rain rate field is attractive, since it naturally leads to a consistent space–time model. In this paper, we note that the spatial covariance structure of the spectral model is equivalent to the well-known Matérn covariance model. Using high-quality rain gauge data, we estimate the parameters of the Matérn model for different time scales and demonstrate that the Matérn model is superior to an exponential model, particularly at short time scales.
Diversity of Mat-Forming Fungi in Relation to Soil Properties, Disturbance, and Forest Ecotype at Crater Lake National Park, Oregon, USA

Directory of Open Access Journals (Sweden)

James M. Trappe

2012-04-01

Full Text Available In forest ecosystems, fungal mats are functionally important in nutrient and water uptake in litter and wood decomposition processes, in carbon resource allocation, soil weathering and in cycling of soil resources. Fungal mats can occur abundantly in forests and are widely distributed globally. We sampled ponderosa pine/white fir and mountain hemlock/noble fir communities at Crater Lake National Park for mat-forming soil fungi. Fungus collections were identified by DNA sequencing. Thirty-eight mat-forming genotypes were identified; members of the five most common genera (Gautieria, Lepiota, Piloderma, Ramaria, and Rhizopogon comprised 67% of all collections. The mycorrhizal genera Alpova and Lactarius are newly identified as ectomycorrhizal mat-forming taxa, as are the saprotrophic genera Flavoscypha, Gastropila, Lepiota and Xenasmatella. Twelve typical mat forms are illustrated, representing both ectomycorrhizal and saprotrophic fungi that were found. Abundance of fungal mats was correlated with higher soil carbon to nitrogen ratios, fine woody debris and needle litter mass in both forest ecotypes. Definitions of fungal mats are discussed, along with some of the challenges in defining what comprises a fungal “mat”.
Evaluating carbon stores at the earth-atmosphere interface: moss and lichen mats of subarctic Alaska

Science.gov (United States)

Robert J. Smith; Sarah Jovan; Bruce. McCune

2015-01-01

A fundamental goal of the forest inventory in interior Alaska is to accurately estimate carbon pools in a way that sheds light on the feedbacks between forests and climate. In boreal forests, moss and lichen mats often serve as the interface between soils and the atmosphere, therefore characterizing the biomass and composition of mats is essential for understanding how...
The Varian MAT-250 mass spectrometer. Steady isotopes laboratory

International Nuclear Information System (INIS)

Hernandez M, V.; Tavera D, M.L.

1997-01-01

This work treats over the performance and applications of the Varian Mat-250 mass spectrometer which is in the environmental isotope laboratory. It can be applied over topics such as: ions formation, acceleration and collimation, ions separation, ions detection, data transformation, sampling, δ notation. (Author)
High influx of carbon in walls of agglutinated foraminifers during the Permian-Triassic transition in global oceans

Science.gov (United States)

Nestell, Galina P.; Nestell, Merlynd K.; Ellwood, Brooks B.; Wardlaw, Bruce R.; Basu, Asish R.; Ghosh, Nilotpal; Phuong Lan, Luu Thi; Rowe, Harry D.; Hunt, Andrew G.; Tomkin, Jonathan H.; Ratcliffe, Kenneth T.

2015-01-01

The Permian–Triassic mass extinction is postulated to be related to the rapid volcanism that produced the Siberian flood basalt (Traps). Unrelated volcanic eruptions producing several episodes of ash falls synchronous with the Siberian Traps are found in South China and Australia. Such regional eruptions could have caused wildfires, burning of coal deposits, and the dispersion of coal fly ash. These eruptions introduced a major influx of carbon into the atmosphere and oceans that can be recognized in the wallstructure of foraminiferal tests present in survival populations in the boundary interval strata. Analysis of free specimens of foraminifers recovered from residues of conodont samples taken at aPermian–Triassic boundary section at Lung Cam in northern Vietnam has revealed the presence of a significant amount of elemental carbon, along with oxygen and silica, in their test wall structure, but an absence of calcium carbonate. These foraminifers, identified as Rectocornuspira kalhori, Cornuspira mahajeri, and Earlandia spp. and whose tests previously were considered to be calcareous, are confirmed to be agglutinated, and are now referred to as Ammodiscus kalhori and Hyperammina deformis. Measurement of the 207Pb/204Pb ratios in pyrite clusters attached to the foraminiferal tests confirmed that these tests inherited the Pb in their outer layer from carbon-contaminated seawater. We conclude that the source of the carbon could have been either global coal fly ash or forest fire-dispersed carbon, or a combination of both, that was dispersed into the Palaeo-Tethys Ocean immediately after the end-Permian extinction event.
Drug-loaded electrospun mats of poly(vinyl alcohol) fibres and their release characteristics of four model drugs

Science.gov (United States)

Taepaiboon, Pattama; Rungsardthong, Uracha; Supaphol, Pitt

2006-05-01

Mats of PVA nanofibres were successfully prepared by the electrospinning process and were developed as carriers of drugs for a transdermal drug delivery system. Four types of non-steroidal anti-inflammatory drug with varying water solubility property, i.e. sodium salicylate (freely soluble in water), diclofenac sodium (sparingly soluble in water), naproxen (NAP), and indomethacin (IND) (both insoluble in water), were selected as model drugs. The morphological appearance of the drug-loaded electrospun PVA mats depended on the nature of the model drugs. The 1H-nuclear magnetic resonance results confirmed that the electrospinning process did not affect the chemical integrity of the drugs. Thermal properties of the drug-loaded electrospun PVA mats were analysed by differential scanning calorimetry and thermogravimetric analysis. The molecular weight of the model drugs played a major role on both the rate and the total amount of drugs released from the as-prepared drug-loaded electrospun PVA mats, with the rate and the total amount of the drugs released decreasing with increasing molecular weight of the drugs. Lastly, the drug-loaded electrospun PVA mats exhibited much better release characteristics of the model drugs than drug-loaded as-cast films.
Expansion rate and geometry of floating vegetation mats on the margins of thermokarst lakes, northern Seward Peninsula, Alaska, USA

Science.gov (United States)

Parsekian, A.D.; Jones, Benjamin M.; Jones, M.; Grosse, G.; Walter, Anthony K.M.; Slater, L.

2011-01-01

Investigations on the northern Seward Peninsula in Alaska identified zones of recent (<50years) permafrost collapse that led to the formation of floating vegetation mats along thermokarst lake margins. The occurrence of floating vegetation mat features indicates rapid degradation of near-surface permafrost and lake expansion. This paper reports on the recent expansion of these collapse features and their geometry is determined using geophysical and remote sensing measurements. The vegetation mats were observed to have an average thickness of 0.57m and petrophysical modeling indicated that gas content of 1.5-5% enabled floatation above the lake surface. Furthermore, geophysical investigation provides evidence that the mats form by thaw and subsidence of the underlying permafrost rather than terrestrialization. The temperature of the water below a vegetation mat was observed to remain above freezing late in the winter. Analysis of satellite and aerial imagery indicates that these features have expanded at maximum rates of 1-2myr-1 over a 56year period. Including the spatial coverage of floating 'thermokarst mats' increases estimates of lake area by as much as 4% in some lakes. ?? 2011 John Wiley & Sons, Ltd.
Effects of filamentous macroalgae mats on growth and survival of eelgrass, Zostera marina, seedlings

DEFF Research Database (Denmark)

Rasmussen, Jonas; Olesen, Birgit; Krause-Jensen, Dorte

2012-01-01

A laboratory experiment was conducted to assess the effect of filamentous algae mats on the performance of seedlings of the eelgrass, Zostera marina. The seedlings were covered by three levels (3, 6 and 9 cm) of natural (Chaetomorpha linum) and imitation algae mats and it was hypothesized that th...
Community phylogenetic analysis of moderately thermophilic cyanobacterial mats from China, the Philippines and Thailand.

Science.gov (United States)

Hongmei, Jing; Aitchison, Jonathan C; Lacap, Donnabella C; Peerapornpisal, Yuwadee; Sompong, Udomluk; Pointing, Stephen B

2005-08-01

Most community molecular studies of thermophilic cyanobacterial mats to date have focused on Synechococcus occurring at temperatures of approximately 50-65 degrees C. These reveal that molecular diversity exceeds that indicated by morphology, and that phylogeographic lineages exist. The moderately thermophilic and generally filamentous cyanobacterial mat communities occurring at lower temperatures have not previously been investigated at the community molecular level. Here we report community diversity in mats of 42-53 degrees C recovered from previously unstudied geothermal locations. Separation of 16S rRNA gene-defined genotypes from community DNA was achieved by DGGE. Genotypic diversity was greater than morphotype diversity in all mats sampled, although genotypes generally corresponded to observed morphotypes. Thirty-six sequences were recovered from DGGE bands. Phylogenetic analyses revealed these to form novel thermophilic lineages distinct from their mesophilic counterparts, within Calothrix, Cyanothece, Fischerella, Phormidium, Pleurocapsa, Oscillatoria and Synechococcus. Where filamentous cyanobacterial sequences belonging to the same genus were recovered from the same site, these were generally closely affiliated. Location-specific sequences were observed for some genotypes recovered from geochemically similar yet spatially separated sites, thus providing evidence for phylogeographic lineages that evolve in isolation. Other genotypes were more closely affiliated to geographically remote counterparts from similar habitats suggesting that adaptation to certain niches is also important.
Mechanism study of selective heavy metal ion removal with polypyrrole-functionalized polyacrylonitrile nanofiber mats

International Nuclear Information System (INIS)

Wang, Jianqiang; Luo, Chao; Qi, Genggeng; Pan, Kai; Cao, Bing

2014-01-01

Graphical abstract: - Highlights: • PAN/PPy core/shell nanofiber used for Cr(VI) removal. • Adsorption mechanisms were investigated. • Selective adsorption performances were investigated. - Abstract: Polyacrylonitrile/polypyrrole (PAN/PPy) core/shell nanofiber mat was prepared through electrospinning followed by a simple chemical oxidation method. The polypyrrole-functionalized nanofiber mats showed selective adsorption performance for anions. The interaction between heavy metal anions and polypyrrole (especially the interaction between Cr 2 O 7 2− and polypyrrole) during the adsorption process was studied. The results showed that the adsorption process included two steps: one was the anion exchange process between the Cl − and Cr(VI), and the other was the redox process for the Cr(VI) ions. The adsorption amount was related to the protonation time of the PAN/PPy nanofiber mat and increased as protonation time increased. Meanwhile, the Cr(VI) ions were reduced to Cr(III) through the reaction with amino groups of polypyrrole (from secondary amines to tertiary amines). PAN/PPy nanofiber mat showed high selectivity for Cr(VI), and the adsorption performance was nearly unaffected by other co-existing anions (Cl − , NO 3 − , and SO 4 2− ) except for PO 4 3− for the pH change
The Harris and Beath footprinting mat: diagnostic validity and clinical use.

Science.gov (United States)

Silvino, N; Evanski, P M; Waugh, T R

1980-09-01

Pain on the plantar aspect of the forefoot is a common malady whose specific cause is often difficult to diagnose. Using the Berkemann Laboratory version of the original mat of Harris and Beath, and a calibration curve, the patterns on a footprint can be translated into their actual pressure values withhin the range of 0.27 kg/cm2 to 4.80 kg/cm2. Using the procedure presented here, inexperienced subjects were able to estimate the pressure values of random prints of unknown pressure within a standard deviation of 0.28 kg/cm2 from their actual values. The mat is valuable for diagnosis of pressure metatarsalgia and other disorders of the foot. The specificity was 0.77, sensitivity was 0.57, with the sum being equal to 1.34. These results indicate that there is a relatively large population of normal people wit excessive localized pressure under their metatarsal heads who do not complain of pain. The apparently low sensitivty of the mat in this study does not seem to be a limitation, but is an indication of the haziness involved in the differential diagnosis of forefoot pain. Pressure metatarsalgia can be quantitated by analysis of the Harris footprint.

Zirconium Hydroxide-coated Nanofiber Mats for Nerve Agent Decontamination.

Science.gov (United States)

Kim, Sohee; Ying, Wu Bin; Jung, Hyunsook; Ryu, Sam Gon; Lee, Bumjae; Lee, Kyung Jin

2017-03-16

Diverse innovative fabrics with specific functionalities have been developed for requirements such as self-decontamination of chemical/biological pollutants and toxic nerve agents. In this work, Zr(OH) 4 -coated nylon-6,6 nanofiber mats were fabricated for the decontamination of nerve agents. Nylon-6,6 fabric was prepared via the electrospinning process, followed by coating with Zr(OH) 4 , which was obtained by the hydrolysis of Zr(OBu) 4 by a sol-gel reaction on nanofiber surfaces. The reaction conditions were optimized by varying the amounts of Zr(OBu) 4 ,the reaction time, and the temperature of the sol-gel reaction. The composite nanofibers show high decontamination efficiency against diisopropylfluorophosphate, which is a nerve agent analogue, due to its high nucleophilicity that aids in the catalysis of the hydrolysis of the phosphonate ester bonds. Composite nanofiber mats have a large potential and can be applied in specific fields such as military and medical markets. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.
Biocompatibility of plasma-treated poly(3-hydroxybutyrate-co-3-hydroxyvalerate) nanofiber mats modified by silk fibroin for bone tissue regeneration

Energy Technology Data Exchange (ETDEWEB)

Unalan, Irem [Biomedical Technologies Department, Graduate School of Natural and Applied Sciences, Dokuz Eylul University, Izmir (Turkey); Colpankan, Oylum [Metallurgical and Materials Engineering Department, Faculty of Engineering, Dokuz Eylul University, Izmir (Turkey); Albayrak, Aylin Ziylan, E-mail: aylin.albayrak@deu.edu.tr [Metallurgical and Materials Engineering Department, Faculty of Engineering, Dokuz Eylul University, Izmir (Turkey); Gorgun, Cansu [Biomedical Technologies Department, Graduate School of Natural and Applied Sciences, Ege University, Izmir (Turkey); Urkmez, Aylin Sendemir [Biomedical Technologies Department, Graduate School of Natural and Applied Sciences, Ege University, Izmir (Turkey); Bioengineering Department, Faculty of Engineering, Ege University, Izmir (Turkey)

2016-11-01

The objective of this study was to produce biocompatible plasma-treated and silk-fibroin (SF) modified poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) nanofiber mats. The mats were plasma-treated using O{sub 2} or N{sub 2} gas to increase their hydrophilicity followed by SF immobilization for the improvement of biocompatibility. Contact angle measurements and SEM showed increased hydrophilicity and no disturbed morphology, respectively. Cell proliferation assay revealed that SF modification together with N{sub 2} plasma (PS/N{sub 2}) promoted higher osteoblastic (SaOs-2) cell viability. Although, O{sub 2} plasma triggered more mineral formation on the mats, it showed poor cell viability. Consequently, the PS/N{sub 2} nanofiber mats would be a potential candidate for bone tissue engineering applications. - Highlights: • N{sub 2}-plasma treated and silk fibroin modified mats do not show hydrophobic recovery. • Biomineralization is better on O{sub 2}-plasma treated and silk fibroin modified mats. • SaOS-2 cells like to proliferate on N{sub 2}-plasma treated surfaces.
Microbial mat of the thermal springs Kuchiger Republic of Buryatia: species composition, biochemical properties and electrogenic activity in biofuel cell

Science.gov (United States)

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.
Linking phylogenetic and functional diversity to nutrient spiraling in microbial mats from Lower Kane Cave (USA).

Science.gov (United States)

Engel, Annette Summers; Meisinger, Daniela B; Porter, Megan L; Payn, Robert A; Schmid, Michael; Stern, Libby A; Schleifer, K H; Lee, Natuschka M

2010-01-01

Microbial mats in sulfidic cave streams offer unique opportunities to study redox-based biogeochemical nutrient cycles. Previous work from Lower Kane Cave, Wyoming, USA, focused on the aerobic portion of microbial mats, dominated by putative chemolithoautotrophic, sulfur-oxidizing groups within the Epsilonproteobacteria and Gammaproteobacteria. To evaluate nutrient cycling and turnover within the whole mat system, a multidisciplinary strategy was used to characterize the anaerobic portion of the mats, including application of the full-cycle rRNA approach, the most probable number method, and geochemical and isotopic analyses. Seventeen major taxonomic bacterial groups and one archaeal group were retrieved from the anaerobic portions of the mats, dominated by Deltaproteobacteria and uncultured members of the Chloroflexi phylum. A nutrient spiraling model was applied to evaluate upstream to downstream changes in microbial diversity based on carbon and sulfur nutrient concentrations. Variability in dissolved sulfide concentrations was attributed to changes in the abundance of sulfide-oxidizing microbial groups and shifts in the occurrence and abundance of sulfate-reducing microbes. Gradients in carbon and sulfur isotopic composition indicated that released and recycled byproduct compounds from upstream microbial activities were incorporated by downstream communities. On the basis of the type of available chemical energy, the variability of nutrient species in a spiraling model may explain observed differences in microbial taxonomic affiliations and metabolic functions, thereby spatially linking microbial diversity to nutrient spiraling in the cave stream ecosystem.
Effect of the flexibility of the base mat on seismic response of a PWR-reactor building

International Nuclear Information System (INIS)

Waas, G.; Riggs, H.R.

1983-01-01

The flexibility of the base mat influences the stiffness and the radiation damping of foundations, In this paper its effect on the seismic response of an axisymmetric PWR-reactor building is investigated. The base mat of the building is stiffened by cylindrical concrete walls and by a rigid block in the center. Soft and stiff soil conditions are considered. The structure and its foundation are modelled by axisymmetric shell and volume elements with Fourier expansions in the circumferential direction. The soil is treated as a horizontally layered viscoelastic medium. Soil and structure are coupled along nodal rings. The stiffness matrix of the soil is computed using an explicit semi-analytic solution for displacements caused by ring loads acting on the surface or within a layered medium. The analysis is performed in the frequency domain, and the response in the time domain is computed by the fast Fourier transformation. The earthquake response is computed with and without including the flexibility of the relatively stiff base mat. The comparison shows that including the flexibility of the mat has hardly any effect on the resonant frequencies and the damping of the fundamental rocking and vertical modes. This is the case for soft and stiff soil conditions. However, the flexibility of the mat strongly affects the first structural deformation mode, in which the external and internal structures deflect in opposite directions. (orig./HP)
Effect of salinity on nitrogenase activity and composition of the active diazotrophic community in intertidal microbial mats

NARCIS (Netherlands)

Severin, I.; Confurius-Guns, V.; Stal, L.J.

2012-01-01

Microbial mats are often found in intertidal areas experiencing a large range of salinities. This study investigated the effect of changing salinities on nitrogenase activity and on the composition of the active diazotrophic community ( transcript libraries) of three types of microbial mats situated
Effect of natural fiber types and sodium silicate coated on natural fiber mat/PLA composites: Tensile properties and rate of fire propagation

Science.gov (United States)

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

International Nuclear Information System (INIS)

Thongpin, C; Srimuk, J; Hipkam, N; Wachirapong, P

2015-01-01

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 H 2 SO 4 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. (paper)
Usefulness of a single-assay chemiluminescence test (Tularaemia VIRCLIA IgG + IgM monotest) for the diagnosis of human tularemia. Comparison of five serological tests.

Science.gov (United States)

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.
Phototrophs in high-iron-concentration microbial mats: physiological ecology of phototrophs in an iron-depositing hot spring

Science.gov (United States)

Pierson, B. K.; Parenteau, M. N.; Griffin, B. M.

1999-01-01

At Chocolate Pots Hot Springs in Yellowstone National Park the source waters have a pH near neutral, contain high concentrations of reduced iron, and lack sulfide. An iron formation that is associated with cyanobacterial mats is actively deposited. The uptake of [(14)C]bicarbonate was used to assess the impact of ferrous iron on photosynthesis in this environment. Photoautotrophy in some of the mats was stimulated by ferrous iron (1.0 mM). Microelectrodes were used to determine the impact of photosynthetic activity on the oxygen content and the pH in the mat and sediment microenvironments. Photosynthesis increased the oxygen concentration to 200% of air saturation levels in the top millimeter of the mats. The oxygen concentration decreased with depth and in the dark. Light-dependent increases in pH were observed. The penetration of light in the mats and in the sediments was determined. Visible radiation was rapidly attenuated in the top 2 mm of the iron-rich mats. Near-infrared radiation penetrated deeper. Iron was totally oxidized in the top few millimeters, but reduced iron was detected at greater depths. By increasing the pH and the oxygen concentration in the surface sediments, the cyanobacteria could potentially increase the rate of iron oxidation in situ. This high-iron-content hot spring provides a suitable model for studying the interactions of microbial photosynthesis and iron deposition and the role of photosynthesis in microbial iron cycling. This model may help clarify the potential role of photosynthesis in the deposition of Precambrian banded iron formations.
Development of a Twin-spool Turbofan Engine Simulation Using the Toolbox for Modeling and Analysis of Thermodynamic Systems (T-MATS)

Science.gov (United States)

Zinnecker, Alicia M.; Chapman, Jeffryes W.; Lavelle, Thomas M.; Litt, Johathan S.

2014-01-01

The Toolbox for Modeling and Analysis of Thermodynamic Systems (T-MATS) is a tool that has been developed to allow a user to build custom models of systems governed by thermodynamic principles using a template to model each basic process. Validation of this tool in an engine model application was performed through reconstruction of the Commercial Modular Aero-Propulsion System Simulation (C-MAPSS) (v2) using the building blocks from the T-MATS (v1) library. In order to match the two engine models, it was necessary to address differences in several assumptions made in the two modeling approaches. After these modifications were made, validation of the engine model continued by integrating both a steady-state and dynamic iterative solver with the engine plant and comparing results from steady-state and transient simulation of the T-MATS and C-MAPSS models. The results show that the T-MATS engine model was accurate within 3 of the C-MAPSS model, with inaccuracy attributed to the increased dimension of the iterative solver solution space required by the engine model constructed using the T-MATS library. This demonstrates that, given an understanding of the modeling assumptions made in T-MATS and a baseline model, the T-MATS tool provides a viable option for constructing a computational model of a twin-spool turbofan engine that may be used in simulation studies.
Brief report on development of indigofera pseudotinctoria mats high flavonoid mutant and anti-oxidation of its exacts

International Nuclear Information System (INIS)

Shen Xiaoxia; Mei Shufang; Shu Xiaoli; Wu Dianxing

2010-01-01

Mutant high in flavonoid was successfully developed after the dry seeds of Indigofera pseudotinctoria Mats were irradiated by 300 Gy 60 Co gamma rays. The contents of flavonoid in different tissues of mutant line MJ-HF1 were all higher than that of the wild type, especially in the seeds and leaves, which was 5.89 and 1.46 times of the wild type. Anti-oxidation testing showed that the flavonoid exacts from MJ-HF1 could decrease the contents of malondialdehyde(MDA) and increase the activities of superoxide dismutase (SOD) in the aged white mice in a 30-day feeding test. (authors)
Comparison of the cystine-tryptic digest agar-carbohydrate co-agglutination and BACTEC Neisseria differentiation methods for identification of Neisseria gonorrhoeae in the clinical laboratory

International Nuclear Information System (INIS)

Morello, J.A.; Beheshti, S.; Bohnhoff, M.

1980-01-01

The author evaluated CTA-carbohydrate, BACTEC and co-agglutination systems to determine their accuracy for identifying N. gonorrhoeae strains and for distinguishing them from other Neisseria species. BACTEC is a radiometric assay based on the measurement of liberated radiolabelled CO 2 from metabolised carbohydrates which have been tagged with 14 C. (Auth.)
Occurrence of antibodies to Toxoplasma gondii in rheas (Rhea americana and ostriches (Struthio camelus from farms of different Brazilian regions

Directory of Open Access Journals (Sweden)

Amanda Brentano Almeida

Full Text Available This study aimed to verify the occurrence of antibodies againstToxoplasma gondii in rheas (Rhea americana and ostriches (Struthio camelus commercially breeding in Brazil. Blood samples from 20 rheas and 46 ostriches (young and adults were serologically tested using a technique known as modified agglutination test (MAT at an initial titration of 1:16 for ostriches and 1:25 for rheas. Antibodies against T. gondii were found in 50% (10/20 of the rheas, with titers ranging from 1:25 to 1:6,400. The incidence of antibodies against T. gondii in ostriches was 17.4% (8/46 with titers ranging from 1:16 to 1:256. Birds showing titers higher than 1:200 forT. gondii were mainly the young ones. Therefore, rheas and ostriches may be parasitized by T. gondii, showing high levels of antibodies against this parasite.
Community structure and function of high-temperature chlorophototrophic microbial mats inhabiting diverse geothermal environments

DEFF Research Database (Denmark)

Klatt, Christian G.; Inskeep, William P.; Herrgard, Markus

2013-01-01

Six phototrophic microbial mat communities from different geothermal springs (YNP) were studied using metagenome sequencing and geochemical analyses. The primary goals of this work were to determine differences in community composition of high-temperature phototrophic mats distributed across...... the Yellowstone geothermal ecosystem, and to identify metabolic attributes of predominant organisms present in these communities that may correlate with environmental attributes important in niche differentiation. Random shotgun metagenome sequences from six phototrophic communities (average 53Mbp/site) were...
Numerical Study on the Seismic Response of Structure with Consideration of the Behavior of Base Mat Uplift

Directory of Open Access Journals (Sweden)

Guo-Bo Wang

2017-01-01

Full Text Available The foundation might be separated from the supporting soil if the earthquake is big enough, which is known as base mat uplift. This paper proposed a simplified calculation model in which spring element is adopted to simulate the interaction between soil and structure. The load-deformation curve (F-D curve of the spring element can be designated to represent the base mat uplift, in which the pressure can be applied while tensile forces are not allowed. Key factors, such as seismic wave types, seismic wave excitation directions, seismic wave amplitudes, soil shear velocities, structure stiffness, and the ratio of structure height to width (H/B, were considered in the analysis. It is shown that (1 seismic wave type has significant influence on structure response due to different frequency components it contained; (2 the vertical input of seismic wave greatly affected structure response in vertical direction, while it has little impacts in horizontal direction; (3 base mat uplift is easier to take place in soil with higher shear velocity; (4 structure H/B value has complicated influence on base mat uplift. The outcome of this research is assumed to provide some references for the seismic design of the structure due to base mat uplift.
Chemical engineering and thermodynamics using Mat lab

International Nuclear Information System (INIS)

Kim Heon; Kim, Moon Gap; Lee, Hak Yeong; Yeo, Yeong Gu; Ham, Seong Won

2002-02-01

This book consists of twelve chapters and four appendixes about chemical engineering and thermodynamics using Mat lab, which deals with introduction, energy budget, entropy, thermodynamics process, generalization on any fluid, engineering equation of state for PVT properties, deviation of the function, phase equilibrium of pure fluid, basic of multicomponent, phase equilibrium of compound by state equation, activity model and reaction system. The appendixes is about summary of computer program, related mathematical formula and material property of pure component.
Matted-fiber divertor tagets for sputter resistance

International Nuclear Information System (INIS)

Gierszewski, P.J.; Todreas, N.E.; Mikic, B.; Yang, T.F.

1981-06-01

Reductions in net sputtering yields can be obtained by altering the surface topography to maximize redeposition of sputtered atoms. A simple analysis is used to indicate a potential reduction by a factor of 2 to 5 for matted fiber divertor targets, relatively independent of incident, reflected and sputtered atom distributions. The fiber temperature is also shown to be acceptable, even up to 10 MW/m 2 , for reasonably combinations of materials, fiber diameter and fiber spacing
Coastal Microbial Mat Diversity along a Natural Salinity Gradient

NARCIS (Netherlands)

Bolhuis, H.; Fillinger, L.; Stal, L.J.

2013-01-01

The North Sea coast of the Dutch barrier island of Schiermonnikoog is covered by microbial mats that initiate a succession of plant communities that eventually results in the development of a densely vegetated salt marsh. The North Sea beach has a natural elevation running from the low water mark to
Establishing Sphagnum cultures on bog grassland, cut-over bogs, and floating mats: procedures, costs and area potential in Germany

Directory of Open Access Journals (Sweden)

S. Wichmann

2017-04-01

Full Text Available Sphagnum biomass is valued as a high-quality constituent of horticultural growing media. The cultivation of Sphagnum (peatmoss was tested successfully on peat soil and on artificial mats floating on acidic water bodies. But whether Sphagnum farming is economically feasible is unclear. Drawing on experience gained during four research projects in Germany we compared the procedures, costs and area potential for establishing large-scale Sphagnum cultures. Establishment costs were clearly lower for soil-based cultivation (€8.35 m-2 to €12.80 m 2 than for water-based cultivation (€17.34 m-2 to €21.43 m-2. Relating costs to the predicted dry mass yield over the total cultivation time resulted in values of €1,723 t-1 on cut-over bog, €2,646 t-1 on former bog grassland, €9,625 t -1 on floating mats without pre-cultivation and €11,833 t-1 on pre-cultivated Sphagnum mats. The high production costs of the mats (without pre-cultivation 54 % and with pre-cultivation 63 % of total costs resulted in the highest overall costs. In the case of soil-based Sphagnum cultures, the costs of purchasing Sphagnum diaspores were most influential (on bog grassland 46 % and on cut-over bog 71 % of total costs. The lowest costs relate to cut-over bog because of the smaller effort required for site preparation compared to taking off the topsoil of former bog grassland and the limited costs for the assumed irrigation system. In the case of former bog grassland, the high investment costs for the project-specific automatic water management boosted the establishment costs. Taking into account potential savings on the irrigation system and the high area potential, bog grassland emerges as the most promising land category for Sphagnum farming in Germany.

Flavours – det smakar doft : Upplevelsen av mat och vin i kombination

OpenAIRE

Hult, Jonas; Lagnetoft, David; Nygren, Nadia

2011-01-01

Inledning: Den vetenskapliga förankringen om mat och vin i kombination är låg. Upplevelsenav en måltid involverar alla de mänskliga sinnena, vilket således har gjort den svår att mäta.Hur stor roll spelar egentligen grundsmakerna och krävs det ytterligare element för att lyfta enkombination av mat och vin till högre höjder?Bakgrund: Förutom smaklökarna på tungan som bildar den grundläggande uppfattningen avdet vi stoppar i munnen, är det främst munkänsla och flavours som bidrar till helheten ...
Context, Biogeochemistry, and Morphology of Diverse and Spatially Extensive Microbial Mats, Little Ambergris Cay, Turks and Caicos Islands, B.W.I.

Science.gov (United States)

Present, T. M.; Trower, L.; Stein, N.; Alleon, J.; Bahniuk, A.; Gomes, M. L.; Lingappa, U.; Metcalfe, K.; Orzechowski, E. A.; Riedman, L. A.; Sanders, C. B.; Morris, D. K.; O'Reilly, S.; Sibert, E. C.; Thorpe, M.; Tarika, M.; Fischer, W. W.; Knoll, A. H.; Grotzinger, J. P.

2017-12-01

Little Ambergris Cay (21.3° N, 71.7° W) was the site of an integrated geobiological study conducted in July 2016 and August 2017. The cay ( 6 km x 1.6 km) is developed on a broad bank influenced by strong easterly trade winds (avg. 7.5 m/s), where convergent ooid shoals culminate in a linear shoal extending almost 25 km westward from the cay. Lithified upper shoreface to eolian ooid grainstones form a 2 m high bedrock rim that protects an extensive interior tidal marsh with well-developed microbial mats. Local breaches in the rim allow tidal flows to inundate interior bays floored by microbial mats. Three mat types were observed based on texture: dark toned "blister mat" that flanks the bays where they intersect with the bedrock rim; light-toned "polygonal mat" that covers broad tracts of the bay and is exposed at low tide; and lighter-toned "EPS mat" that is generally submerged even at low tide. The millimeter-to decimeter-thick layered mats overlie laterally extensive ooid sands, generally unlithified except for a few hardgrounds. The mats and underlying sediments were sampled by vibracoring, push coring, and piezometers. Biogeochemical analyses include groundwater salinity, pH, DIC, alkalinity, cation composition, DNA content, photosynthetic efficiency, C and S isotope composition, lipid biomarkers, and taphonomic state. Groundwater and interstitial water chemical analyses were integrated with hydrologic observations of tidal channels' level and flow. Visible light UAV images from 350 m standoff distance were processed to generate a 15 cm/pixel mosaic of the island that was used in combination with a DGPS survey, multispectral Landsat images (m-scale resolution) and Worldview satellite images (30 cm resolution) to map the island's topography, mats, and sedimentologic facies. A UAV-based VNIR hyperspectral camera was used to quantify pigment concentrations in the mats at cm-resolution over decameter scales. Sub-cm-scale bed textures, including those expressed
Dynamics of bacterial populations during bench-scale bioremediation of oily seawater and desert soil bioaugmented with coastal microbial mats.

Science.gov (United States)

Ali, Nidaa; Dashti, Narjes; Salamah, Samar; Sorkhoh, Naser; Al-Awadhi, Husain; Radwan, Samir

2016-03-01

This study describes a bench-scale attempt to bioremediate Kuwaiti, oily water and soil samples through bioaugmentation with coastal microbial mats rich in hydrocarbonoclastic bacterioflora. Seawater and desert soil samples were artificially polluted with 1% weathered oil, and bioaugmented with microbial mat suspensions. Oil removal and microbial community dynamics were monitored. In batch cultures, oil removal was more effective in soil than in seawater. Hydrocarbonoclastic bacteria associated with mat samples colonized soil more readily than seawater. The predominant oil degrading bacterium in seawater batches was the autochthonous seawater species Marinobacter hydrocarbonoclasticus. The main oil degraders in the inoculated soil samples, on the other hand, were a mixture of the autochthonous mat and desert soil bacteria; Xanthobacter tagetidis, Pseudomonas geniculata, Olivibacter ginsengisoli and others. More bacterial diversity prevailed in seawater during continuous than batch bioremediation. Out of seven hydrocarbonoclastic bacterial species isolated from those cultures, only one, Mycobacterium chlorophenolicum, was of mat origin. This result too confirms that most of the autochthonous mat bacteria failed to colonize seawater. Also culture-independent analysis of seawater from continuous cultures revealed high-bacterial diversity. Many of the bacteria belonged to the Alphaproteobacteria, Flavobacteria and Gammaproteobacteria, and were hydrocarbonoclastic. Optimal biostimulation practices for continuous culture bioremediation of seawater via mat bioaugmentation were adding the highest possible oil concentration as one lot in the beginning of bioremediation, addition of vitamins, and slowing down the seawater flow rate. © 2016 The Author. Microbial Biotechnology published by John Wiley & Sons Ltd and Society for Applied Microbiology.
Spatial structure and activity of sedimentary microbial communities underlying a Beggiatoa spp. mat in a Gulf of Mexico hydrocarbon seep.

Directory of Open Access Journals (Sweden)

Karen G Lloyd

Full Text Available BACKGROUND: Subsurface fluids from deep-sea hydrocarbon seeps undergo methane- and sulfur-cycling microbial transformations near the sediment surface. Hydrocarbon seep habitats are naturally patchy, with a mosaic of active seep sediments and non-seep sediments. Microbial community shifts and changing activity patterns on small spatial scales from seep to non-seep sediment remain to be examined in a comprehensive habitat study. METHODOLOGY/PRINCIPAL FINDINGS: We conducted a transect of biogeochemical measurements and gene expression related to methane- and sulfur-cycling at different sediment depths across a broad Beggiatoa spp. mat at Mississippi Canyon 118 (MC118 in the Gulf of Mexico. High process rates within the mat ( approximately 400 cm and approximately 10 cm from the mat's edge contrasted with sharply diminished activity at approximately 50 cm outside the mat, as shown by sulfate and methane concentration profiles, radiotracer rates of sulfate reduction and methane oxidation, and stable carbon isotopes. Likewise, 16S ribosomal rRNA, dsrAB (dissimilatory sulfite reductase and mcrA (methyl coenzyme M reductase mRNA transcripts of sulfate-reducing bacteria (Desulfobacteraceae and Desulfobulbaceae and methane-cycling archaea (ANME-1 and ANME-2 were prevalent at the sediment surface under the mat and at its edge. Outside the mat at the surface, 16S rRNA sequences indicated mostly aerobes commonly found in seawater. The seep-related communities persisted at 12-20 cm depth inside and outside the mat. 16S rRNA transcripts and V6-tags reveal that bacterial and archaeal diversity underneath the mat are similar to each other, in contrast to oxic or microoxic habitats that have higher bacterial diversity. CONCLUSIONS/SIGNIFICANCE: The visual patchiness of microbial mats reflects sharp discontinuities in microbial community structure and activity over sub-meter spatial scales; these discontinuities have to be taken into account in geochemical and
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.

Science.gov (United States)

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.
[EIA-IgG antibody measles prevention level estimated from measles neutralizing, particle agglutination and hemagglutination-inhibition antibody titer].

Science.gov (United States)

Takayama, Naohide; Saika, Shizuko; Ichinohe, Sadato

2009-09-01

Measles hemagglutination inhibition (HI) antibody titer, widely used in clinical practice to simply and easily determine the measles immunity level has, in recent years, been increasingly replaced by measles IgG-antibody titer determined by enzyme-immunoassay (EIA). HI antibody titer appears to reflect this protective level, because HI measures the antibody against H protein required for the measles virus to adhere to host cells. EIA-IgG antibody titer does not correlate with the protective level, similar to particle agglutination (PA) titer, because EIA measures different antibodies, including those unrelated to measles protection. After determining HI, PA, neutralizing test (NT) results, and EIA-IgG antibody titer for individual specimens, we compared EIA-IgG antibody titer obtained using an EIA-Kit (Denka Seiken) to HI, PA, and NT titer with the following results: (1) Subjects with EIA-IgG titer of > or = 12.0 may be protected against measles: (2) Subjects with EIA-IgG titer of 4.0 to 8.0 appear to be protected insufficiently requiring a booster dose against measles: (3) Subjects with EIA-IgG titer of 8.0 to 12.0 may benefit from booster vaccination.
Mechanical and thermal properties of biocomposites from nonwoven industrial Fique fiber mats with Epoxy Resin and Linear Low Density Polyethylene

Science.gov (United States)

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.
Enhanced Piezoelectricity in a Robust and Harmonious Multilayer Assembly of Electrospun Nanofiber Mats and Microbead-Based Electrodes.

Science.gov (United States)

Kim, Young Won; Lee, Han Bit; Yeon, Si Mo; Park, Jeanho; Lee, Hye Jin; Yoon, Jonghun; Park, Suk Hee

2018-02-14

Here, we present a simple yet highly efficient method to enhance the output performance of a piezoelectric device containing electrospun nanofiber mats. Multiple nanofiber mats were assembled together to harness larger piezoelectric sources in the as-spun fibers, thereby providing enhanced voltage and current outputs compared to those of a single-mat device. In addition to the multilayer assembly, microbead-based electrodes were integrated with the nanofiber mats to deliver a complexed compression and tension force excitation to the piezoelectric layers. A vacuum-packing process was performed to attain a tight and well-organized assembly of the device components even though the total thickness was several millimeters. The integrated piezoelectric device exhibited a maximum voltage and current of 10.4 V and 2.3 μA, respectively. Furthermore, the robust integrity of the device components could provide high-precision sensitivity to perceive small pressures down to approximately 100 Pa while retaining a linear input-output relationship.
Mechanism study of selective heavy metal ion removal with polypyrrole-functionalized polyacrylonitrile nanofiber mats

Energy Technology Data Exchange (ETDEWEB)

Wang, Jianqiang; Luo, Chao [Key Laboratory of Carbon Fiber and Functional Polymers, Ministry of Education, Beijing University of Chemical Technology, Beijing 100029 (China); Qi, Genggeng [Department of Materials Science and Engineering, Cornell University, Ithaca, NY (United States); Pan, Kai, E-mail: pankai@mail.buct.edu.cn [Key Laboratory of Carbon Fiber and Functional Polymers, Ministry of Education, Beijing University of Chemical Technology, Beijing 100029 (China); Department of Materials Science and Engineering, Cornell University, Ithaca, NY (United States); Cao, Bing, E-mail: bcao@mail.buct.edu.cn [Key Laboratory of Carbon Fiber and Functional Polymers, Ministry of Education, Beijing University of Chemical Technology, Beijing 100029 (China)

2014-10-15

Graphical abstract: - Highlights: • PAN/PPy core/shell nanofiber used for Cr(VI) removal. • Adsorption mechanisms were investigated. • Selective adsorption performances were investigated. - Abstract: Polyacrylonitrile/polypyrrole (PAN/PPy) core/shell nanofiber mat was prepared through electrospinning followed by a simple chemical oxidation method. The polypyrrole-functionalized nanofiber mats showed selective adsorption performance for anions. The interaction between heavy metal anions and polypyrrole (especially the interaction between Cr{sub 2}O{sub 7}{sup 2−} and polypyrrole) during the adsorption process was studied. The results showed that the adsorption process included two steps: one was the anion exchange process between the Cl{sup −} and Cr(VI), and the other was the redox process for the Cr(VI) ions. The adsorption amount was related to the protonation time of the PAN/PPy nanofiber mat and increased as protonation time increased. Meanwhile, the Cr(VI) ions were reduced to Cr(III) through the reaction with amino groups of polypyrrole (from secondary amines to tertiary amines). PAN/PPy nanofiber mat showed high selectivity for Cr(VI), and the adsorption performance was nearly unaffected by other co-existing anions (Cl{sup −}, NO{sub 3}{sup −}, and SO{sub 4}{sup 2−}) except for PO{sub 4}{sup 3−} for the pH change.
Direct Detection of Methicillin Resistance in Staphylococcus aureus in Blood Culture Broth by Use of a Penicillin Binding Protein 2a Latex Agglutination Test▿

OpenAIRE

Qian, Qinfang; Venkataraman, Lata; Kirby, James E.; Gold, Howard S.; Yamazumi, Toshiaki

2010-01-01

We studied the utility of performing a penicillin binding protein 2a latex agglutination (PBP-LA) assay directly on Bactec blood culture broth samples containing Staphylococcus aureus to rapidly detect methicillin resistance. The sensitivity, specificity, positive predictive value, and negative predictive value of this method were 94.1%, 97.5%, 98%, and 92.9%, respectively.
Constitutive modelling of creep in a long fiber random glass mat thermoplastic composite

Science.gov (United States)

Dasappa, Prasad

The primary objective of this proposed research is to characterize and model the creep behaviour of Glass Mat Thermoplastic (GMT) composites under thermo-mechanical loads. In addition, tensile testing has been performed to study the variability in mechanical properties. The thermo-physical properties of the polypropylene matrix including crystallinity level, transitions and the variation of the stiffness with temperature have also been determined. In this work, the creep of a long fibre GMT composite has been investigated for a relatively wide range of stresses from 5 to 80 MPa and temperatures from 25 to 90°C. The higher limit for stress is approximately 90% of the nominal tensile strength of the material. A Design of Experiments (ANOVA) statistical method was applied to determine the effects of stress and temperature in the random mat material which is known for wild experimental scatter. Two sets of creep tests were conducted. First, preliminary short-term creep tests consisting of 30 minutes creep followed by recovery were carried out over a wide range of stresses and temperatures. These tests were carried out to determine the linear viscoelastic region of the material. From these tests, the material was found to be linear viscoelastic up-to 20 MPa at room temperature and considerable non-linearities were observed with both stress and temperature. Using Time-Temperature superposition (TTS) a long term master curve for creep compliance for up-to 185 years at room temperature has been obtained. Further, viscoplastic strains were developed in these tests indicating the need for a non-linear viscoelastic viscoplastic constitutive model. The second set of creep tests was performed to develop a general non-linear viscoelastic viscoplastic constitutive model. Long term creep-recovery tests consisting of 1 day creep followed by recovery has been conducted over the stress range between 20 and 70 MPa at four temperatures: 25°C, 40°C, 60°C and 80°C. Findley's model
Diagnostic accuracy of an in-house ELISA using the intermediate species Leptospira fainei as antigen for diagnosis of acute leptospirosis in dogs.

Science.gov (United States)

Penna, Bruno; Marassi, Carla D; Libonati, Hugo; Narduche, Lorena; Lilenbaum, Walter; Bourhy, Pascale

2017-02-01

Diagnosis of animal leptospirosis is still challenging. The microscopic agglutination test, is the current method for diagnosing leptospirosis. However, this technique requires specific equipment, highly trained staff and the maintenance of live cultures of several reference strains of Leptospira for use as antigens. Recently, an ELISA (enzyme-linked immunosorbent assay) employing a Leptospira fainei serovar Hurstbridge based antigen for the early diagnostic of human leptospirosis was developed. In this study we estimate the diagnostic sensitivity and specificity of this test in identifying acute canine leptospirosis. A total of 271 serum samples divided into five panels and tested by MAT as a reference test, were used to evaluate the ELISA. Comparing acutely and non-acutely infected dogs, ELISA-Hb showed 95.6% sensitivity and 93% specificity. L. fainei-based ELISA is adequate for diagnosing acute canine leptospirosis, with high sensitivity and specificity and presenting practical advantages when compared to current techniques. Copyright © 2016 Elsevier Ltd. All rights reserved.
Polymer solution, fiber mat, and nanofiber membrane-electrode-assembly therewith, and method of fabricating same

DEFF Research Database (Denmark)

2016-01-01

of fibers. The fibers may further include particles of a catalyst. The fiber mat may be used to form an electrode or a membrane. In a further aspect, a fuel cell membrane-electrode-assembly has an anode electrode, a cathode electrode, and a membrane disposed between the anode electrode and the cathode...... electrode. Each of the anode electrode, the cathode electrode and the membrane may be formed with a fiber mat....
Assessing Children's Anxiety Using the Modified Short State-Trait Anxiety Inventory and Talking Mats: A Pilot Study

Directory of Open Access Journals (Sweden)

Stefan Nilsson

2012-01-01

Full Text Available Background. Preoperative anxiety complicates treatment and requires assessment by nurses in children. Children, with or without disability, are helped when pictures are used to support communication. The purpose of this pilot study was to test the reliability and validity of the modified short State-Trait Anxiety Inventory (STAI using a modified Talking Mats method in children undergoing day surgeries. Method. A modified short STAI with pictorial support along the lines of the Talking Mats method was pre- and postoperatively administered to 42 typically developing children aged three to nine years. The parents assessed the children’s anxiety, simultaneously and independently, by scoring the short STAI by proxy. Results. The modified short STAI showed moderate internal consistency and good construct validity in the age group seven to nine years. Conclusions. The results of this study support the use of the instrument for self-reports in children aged seven to nine years. Future research will explore the possibilities of also using this instrument for children with cognitive and communicative difficulties.
Effect of salinity on carbon and sulfur cycles in Umm Alhool sabkha microbial mat ecosystem in Qatar

KAUST Repository

Alnajjar, Mohammad Ahmad

2012-10-19

Microbial mats are only present under extreme conditions, where grazing by higher organisms is limited. Therefore, microbial mats may provide insight into extraterrestrial life, due to their adaptations to extreme temperatures, desiccation or salinity. They are faced with a diurnal cycle with variable length based on their location, which exposes them to extreme salinity conditions (i.e., water withdrawal and high evaporation). Cyanobacteria in the photic zone of a mat ecosystem supply the other microorganism with the required organic material to produce energy and grow. Subsequently, this will reproduce the nutrients needed by the phototrophs through elemental re-mineralization. In this work, we investigated the effect of water salinity that covers the microbial mat ecosystem of Umm Alhool sabkha, Qatar, regarding the most important processes within microbial mats: photosynthesis and sulfate reduction (SR). Our results showed that both photosynthetic and sulfate reduction rates decreased with increasing the salinity. The microbial community structure, assessed by 454 pyro-sequencing, revealed that the cyanobacterial community structure changed in response to the change in salinity. This was not the case for the sulfate reducer community structure, which stayed as it is in the mats incubated at different salinities. Therefore, we speculate that salinity affects the photosynthetic community structure, and consequently affects the photosynthetic activity of the whole ecosystem. However, sulfate reduction rates decreased due to less organic material supply from the upper layers and not due to change in microbial community structure of SR. Other factors such as the activity of the enzymes could also have an effect on SRR, but it was not investigated in this study.
VocMat projekt - uudsed e-õppe võimalused turismiasjalistele / Heli Tooman

Index Scriptorium Estoniae

Tooman, Heli, 1949-

2008-01-01

Turismivaldkonna spetsialistidele mõeldud koolitusprojektist VocMat (Vocational Management Training for the Tourism Industry). Projekti partneriteks Eestis on Ettevõtluse Arendamise Sihtasutuse Turismiarenduskeskus ja Tartu Ülikooli Pärnu kolledzh. Lisa: Kokkuvõte
Seroprevalence, Detection of DNA in Blood and Milk, and Genotyping of Toxoplasma gondii in a Goat Population in Italy

Directory of Open Access Journals (Sweden)

Francesca Mancianti

2013-01-01

Full Text Available Toxoplasma gondii is the causative agent of a major zoonosis with cosmopolitan distribution and is known to be transmitted mainly by the ingestion of undercooked or raw animal products. Drinking unpasteurized goat’s milk is a risk factor associated with human toxoplasmosis. However, very little is known about the excretion of DNA in goat milk. Aim of the present study was to determine the seroprevalence of T. gondii infection using a modified agglutination test (MAT, to detect T. gondii DNA by nested-PCR (n-PCR in samples of blood and milk from seropositive goats, and to genotype DNA isolates using 11 molecular markers in 127 adult lactating goats from 6 farms in Italy. Positive MAT results were found in 60.6% of goats while 13% of blood and milk samples from seropositive goats were positive to n-PCR. A kappa coefficient of 1 indicated a perfect agreement between blood and milk n-PCR. Genetic characterization of isolates revealed the occurrence of genotype III (, genotype I (, and atypical genotypes with hints for genotype I (. Our results suggest that the risk of excretion of Toxoplasma tachyzoites might frequently occur in milk of seropositive goats testing positive to n-PCR on blood.
Seroprevalence of Toxoplasma gondii infection in captive mammals in three zoos in Mexico City, Mexico.

Science.gov (United States)

Alvarado-Esquivel, Cosme; Gayosso-Dominguez, Edgar Arturo; Villena, Isabelle; Dubey, J P

2013-09-01

Antibodies to Toxoplasma gondii were determined in 167 mammals in three 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); 4 of 4 cougars (Puma concolor); 10 of 13 jaguars (Panthera onca); 5 of 5 leopards (Panthera pardus); 7 of 7 lions (Panthera leo); 2 of 3 tigers (Panthera tigris); 2 of 3 ocelots (Leopardus pardalis); 2 of 2 Sumatran tigers (Panthera tigris sumatrae); lof 2 Jaguarundi (Herpailurus jagouaroundi); but not in 0 of 2 oncillas (Leopardus tigrinus). Such high seroprevalence in wild felids is of public health significance because of the potential of oocyst shedding. Four of 6 New World primates (2 of 2 Geoffroy's spider monkeys [Ateles geoffroyi], 1 of 3 Patas monkeys [Erythrocebus patas], and 1 of 1 white-headed capuchin [Cebus capucinus]) had high MAT titers of 3,200, suggesting recently acquired infection; these animals are highly susceptible to clinical toxoplasmosis. However, none of these animals were ill. Seropositivity to T. gondii was found for the first time in a number of species.
Prevalence of agglutinating antibodies to Toxoplasma gondii in striped skunks (Mephitis mephitis), opossums (Didelphis virginiana), and raccoons (Procyon lotor) from Connecticut

OpenAIRE

Mitchell, S. M.; Richardson, D. J.; Lindsay, D. S.

2006-01-01

The prevalence of agglutinating antibodies to Toxoplasma gondii was examined in striped skunks (Mephitis mephitis), opossums (Didelphis virginiana), and raccoons (Procyon lotor) from 8 cities in Connecticut. Ten (42%) of the 24 striped skunks, 2 of 7 (29%) opossums, and 12 of 12 (100%) raccoons were positive at dilutions of 1:50 or greater. These results suggest that T. gondii is prevalent in the environment, or prey items, or both, of these omnivores in Connecticut.
Prevalence of agglutinating antibodies to Toxoplasma gondii in striped skunks (Mephitis mephitis), opossums (Didelphis virginiana), and raccoons (Procyon lotor) from Connecticut.

Science.gov (United States)

Mitchell, Sheila M; Richardson, Dennis J; Lindsay, David S

2006-06-01

The prevalence of agglutinating antibodies to Toxoplasma gondii was examined in striped skunks (Mephitis mephitis), opossums (Didelphis virginiana), and raccoons (Procyon lotor) from 8 cities in Connecticut. Ten (42%) of the 24 striped skunks, 2 of 7 (29%) opossums, and 12 of 12 (100%) raccoons were positive at dilutions of 1:50 or greater. These results suggest that T. gondii is prevalent in the environment, or prey items, or both, of these omnivores in Connecticut.

Biocidal Activity of Plasma Modified Electrospun Polysulfone Mats Functionalized with Polyethyleneimine-Capped Silver Nanoparticles

KAUST Repository

Schiffman, Jessica D.

2011-11-01

The incorporation of silver nanoparticles (AgNPs) into polymeric nanofibers has attracted a great deal of attention due to the strong antimicrobial activity that the resulting fibers exhibit. However, bactericidal efficacy of AgNP-coated electrospun fibrous mats has not yet been demonstrated. In this study, polysulfone (PSf) fibers were electrospun and surface-modified using an oxygen plasma treatment, which allowed for facile irreversible deposition of cationically charged polyethyleneimine (PEI)-AgNPs via electrostatic interactions. The PSf-AgNP mats were characterized for relative silver concentration as a function of plasma treatment time using ICP-MS and changes in contact angle. Plasma treatment of 60 s was the shortest time required for maximum loss of bacteria (Escherichia coli) viability. Time-dependent bacterial cytotoxicity studies indicate that the optimized PSf-AgNP mats exhibit a high level of inactivation against both Gram negative bacteria, Escherichia coli, and Gram positive bacteria, Bacillus anthracis and Staphylococcus aureus. © 2011 American Chemical Society.
Large red cyanobacterial mats (Spirulina subsalsa Oersted ex Gomont in the shallow sublittoral of the southern Baltic

Directory of Open Access Journals (Sweden)

Piotr Balazy

2014-06-01

Full Text Available We report the first observation of large red cyanobacterial mats in the southern Baltic Sea. The mats (up to 2.5 m in diameter were observed by SCUBA divers at 7.7 m depth on loamy sediments in the Gulf of Gdańsk in mid-November 2013. The main structure of the mat was formed by cyanobacteria Spirulina subsalsa Oersted ex Gomont; a number of other cyanobacteria, diatoms and nematode species were also present. After a few days in the laboratory, the red trichomes of S. subsalsa started to turn blue-green in colour, suggesting the strong chromatic acclimation abilities of this species.
The development of stromatolitic features from laminated microbial mats in the coastal sabkha of Abu Dhabi (UAE)

Science.gov (United States)

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

2017-04-01

Stromatolitic features are documented from both marine and terrestrial environments worldwide. These features form through a combination of trapping and binding of allochthonous grains, and through microbially mediated and/or controlled precipitation of carbonate minerals. The combined effects of these processes result in the continuous vertical and lateral growth of stromatolites. While the Abu Dhabi coastal sabkha is well known for a vast microbial mat belt that is dominated by continuous polygonal and internally-laminated microbial mats, no stromatolitic features have been reported from this area so far. In this study, we report evidence for stromatolitic features from the coastal sabkha of Abu Dhabi, based on observations in an intertidal but permanently submerged pool. This pool lies embedded within the laminated microbial mat zone, and is marked by the development of true laminated stromatolite at its margins and microbial build-ups at its centre. In order to characterise processes that lead to the formation of these stromatolitic features, and to develop a conceptual model that describes their development in the context of variations in sea level, tidal energy and other environmental factors, we employ a multitude of environmental, sedimentological, mineralogical and geochemical methods. These methods include the analysis of water data in terms of temporal variations in temperature, salinity, dissolved oxygen and water level, the analysis of petrographic thin sections of both lithified and unlithified features as well as an analysis of the stromatolites' mineralogical composition, and the amounts of incorporated organic carbon and calcium carbonate. Initial results suggest that the development of the observed stromatolitic features in the coastal sabkha of Abu Dhabi is the result of a complex interplay between simultaneous erosion of laminated microbial mat, and biotic/abiotic lithification processes. Initially, the location of this pool was characterised by
Electrospun silk-elastin-like fibre mats for tissue engineering applications

International Nuclear Information System (INIS)

Machado, Raul; Da Costa, André; Padrão, Jorge; Gomes, Andreia; Casal, Margarida; Sencadas, Vitor; Costa, Carlos M; Lanceros-Méndez, Senentxu; Garcia-Arévalo, Carmen; Rodríguez-Cabello, José Carlos

2013-01-01

Protein-based polymers are present in a wide variety of organisms fulfilling structural and mechanical roles. Advances in protein engineering and recombinant DNA technology allow the design and production of recombinant protein-based polymers (rPBPs) with an absolute control of its composition. Although the application of recombinant proteins as biomaterials is still an emerging technology, the possibilities are limitless and far superior to natural or synthetic materials, as the complexity of the structural design can be fully customized. In this work, we report the electrospinning of two new genetically engineered silk-elastin-like proteins (SELPs) consisting of alternate silk- and elastin-like blocks. Electrospinning was performed with formic acid and aqueous solutions at different concentrations without addition of further agents. The size and morphology of the electrospun structures was characterized by scanning electron microscopy showing its dependence on the concentration and solvent used. Treatment with methanol-saturated air was employed to stabilize the structure and promote water insolubility through a time-dependent conversion of random coils into β-sheets (FTIR). The resultant methanol-treated electrospun mats were characterized for swelling degree (570–720%), water vapour transmission rate (1083 g/m 2 /day) and mechanical properties (modulus of elasticity ∼126 MPa). Furthermore, the methanol-treated SELP fibre mats showed no cytotoxicity and were able to support adhesion and proliferation of normal human skin fibroblasts. Adhesion was characterized by a filopodia-mediated mechanism. These results demonstrate that SELP fibre mats can provide promising solutions for the development of novel biomaterials suitable for tissue engineering applications. (paper)
Response of cyanobacterial mats to nutrient and salinity changes

Czech Academy of Sciences Publication Activity Database

Rejmánková, E.; Komárková, Jaroslava

2005-01-01

Roč. 83, č. 2 (2005), s. 87-107 ISSN 0304-3770. [INTECOL International Wetlands Conference /7./. Utrecht, 25.07.2004-30.7.2004] Grant - others:NSF(US) 0089211 Institutional research plan: CEZ:AV0Z60170517 Keywords : cyanobacterial mats * Belize * P-N impact Subject RIV: EH - Ecology, Behaviour Impact factor: 1.344, year: 2005
Evaluation of the WavTrac Expeditionary Mobility Matting System

Science.gov (United States)

2017-04-01

Dr. Timothy W. Rushing was Chief, APB; Dr. Gordon W. McMahon was Chief, ESMD; and Nicholas Boone was the Technical Director for Force Projection...were tan in color and had a nonskid material applied to the wearing surface. Typical mat dimensions were 12 ft, 2 in. wide by 48 ft, 6 in. long
Advanced HVAC modeling with FemLab/Simulink/MatLab

NARCIS (Netherlands)

Schijndel, van A.W.M.

2003-01-01

The combined MatLab toolboxes FemLab and Simulink are evaluated as solvers for HVAC problems based on partial differential equations (PDEs). The FemLab software is designed to simulate systems of coupled PDEs, 1-D, 2-D or 3-D, nonlinear and time dependent. In order to show how the program works, a
Effect of cross-linking on properties and release characteristics of sodium salicylate-loaded electrospun poly(vinyl alcohol) fibre mats

International Nuclear Information System (INIS)

Taepaiboon, Pattama; Rungsardthong, Uracha; Supaphol, Pitt

2007-01-01

Cross-linking of electrospun (e-spun) fibre mats (beaded fibre morphology with the average diameter of the fibre segments between beads being ∼108 nm) of poly(vinyl alcohol) (PVA) containing sodium salicylate (SS), used as the model drug, was achieved by exposing the fibre mats to the vapour from 5.6 M aqueous solution of either glutaraldehyde or glyoxal for various exposure time intervals, followed by a heat treatment in a vacuum oven. With increasing the exposure time in the cross-linking chamber, the morphology of the e-spun fibre mats gradually changed from a porous to dense structure. Both the degree of swelling and the percentage of weight loss of the cross-linked fibre mats (i.e. ∼200-530% and ∼15-57%, respectively) were lower than those of the untreated ones (i.e. ∼610% and ∼67%, respectively). Cross-linking was also responsible for the monotonic increase in the storage moduli of the cross-linked SS-loaded e-spun PVA fibre mats with increasing exposure time in the cross-linking chamber. The release characteristic of the model drug from the SS-loaded e-spun PVA fibre mats both before and after cross-linking was assessed by the transdermal diffusion through a pig skin method. The cumulative release of the drug from these matrices could be divided into two stages: 0-4 and 4-72 h, in which the amount of SS released in the first stage increased very rapidly, while it was much slower in the second stage. Cross-linking slowed down the release of SS from the drug-loaded fibre mats appreciably and both the rate of release and the total amount of the drug released were decreasing functions of the exposure time interval in the cross-linking chamber. Lastly, the cross-linked SS-loaded e-spun PVA fibre mats were non-toxic to normal human dermal fibroblasts
Multi-locus DNA barcoding identifies matK as a suitable marker for species identification in Hibiscus L.

Science.gov (United States)

Poovitha, Sundar; Stalin, Nithaniyal; Balaji, Raju; Parani, Madasamy

2016-12-01

The genus Hibiscus L. includes several taxa of medicinal value and species used for the extraction of natural dyes. These applications require the use of authentic plant materials. DNA barcoding is a molecular method for species identification, which helps in reliable authentication by using one or more DNA barcode marker. In this study, we have collected 44 accessions, representing 16 species of Hibiscus, distributed in the southern peninsular India, to evaluate the discriminatory power of the two core barcodes rbcLa and matK together with the suggested additional regions trnH-psbA and ITS2. No intraspecies divergence was observed among the accessions studied. Interspecies divergence was 0%-9.6% with individual markers, which increased to 0%-12.5% and 0.8%-20.3% when using two- and three-marker combinations, respectively. Differentiation of all the species of Hibiscus was possible with the matK DNA barcode marker. Also, in two-marker combinations, only those combinations with matK differentiated all the species. Though all the three-marker combinations showed 100% species differentiation, species resolution was consistently better when the matK marker formed part of the combination. These results clearly showed that matK is more suitable when compared to rbcLa, trnH-psbA, and ITS2 for species identification in Hibiscus.
Development of a Twin-Spool Turbofan Engine Simulation Using the Toolbox for the Modeling and Analysis of Thermodynamic Systems (T-MATS)

Science.gov (United States)

Zinnecker, Alicia M.; Chapman, Jeffryes W.; Lavelle, Thomas M.; Litt, Jonathan S.

2014-01-01

The Toolbox for the Modeling and Analysis of Thermodynamic Systems (T-MATS) is a tool that has been developed to allow a user to build custom models of systems governed by thermodynamic principles using a template to model each basic process. Validation of this tool in an engine model application was performed through reconstruction of the Commercial Modular Aero-Propulsion System Simulation (C-MAPSS) (v2) using the building blocks from the T-MATS (v1) library. In order to match the two engine models, it was necessary to address differences in several assumptions made in the two modeling approaches. After these modifications were made, validation of the engine model continued by integrating both a steady-state and dynamic iterative solver with the engine plant and comparing results from steady-state and transient simulation of the T-MATS and C-MAPSS models. The results show that the T-MATS engine model was accurate within 3% of the C-MAPSS model, with inaccuracy attributed to the increased dimension of the iterative solver solution space required by the engine model constructed using the T-MATS library. This demonstrates that, given an understanding of the modeling assumptions made in T-MATS and a baseline model, the T-MATS tool provides a viable option for constructing a computational model of a twin-spool turbofan engine that may be used in simulation studies.
49 CFR 393.108 - How is the working load limit of a tiedown, or the load restraining value of a friction mat...

Science.gov (United States)

2010-10-01

... load restraining value of a friction mat, determined? 393.108 Section 393.108 Transportation Other... load restraining value of a friction mat, determined? (a) The working load limit (WLL) of a tiedown... load limits. (g) Friction mats which are not marked or rated by the manufacturer shall be considered to...
El tablero de bambú prensado, una nueva propuesta tecnológica The bamboo mat board, a new technological proposal

Directory of Open Access Journals (Sweden)

Lena Mora Rodriguez

2008-01-01

Full Text Available Este artículo presenta un estudio que propone el uso de bambú como una nueva tecnología de madera laminada. La tecnología usa tejidos de bambú dispuestos de manera ortogonal formando tableros que pueden reemplazar a la madera tradicional en ciertos elementos estructurales. Tableros de bambú prensados, hechos con Bambusa Vulgaris Schrab y diferentes presiones y temperaturas durante la fabricación, son caracterizados en el laboratorio mediante ensayos mecánicos.This paper presents a study that proposes the use of bamboo as a new laminated wood technology. The technology uses pressed fabrics of bamboo placed in orthogonal directions to build mat boards that can replace wood in certain structural elements. Bamboo mat boards, made with Bambusa Vulgaris Schrab using different temperatures and pressure during fabrication, are characterized in the lab by means of mechanical testing.
Inter- and intra-examiner reliability of footprint pattern analysis obtained from diabetics using the Harris mat.

Science.gov (United States)

Cisneros, Lígia de Loiola; Fonseca, Tiago H S; Abreu, Vivianni C

2010-01-01

High plantar pressure is a proven risk factor for ulceration among individuals with diabetes mellitus. The Harris and Beath footprinting mat is one of the tools used in screening for foot ulceration risk among these subjects. There are no reports in the literature on the reliability of footprint analysis using print pattern criteria. The aim of this study was to evaluate the inter- and intra-examiner reliability of the analysis of footprint patterns obtained using the Harris and Beath footprinting mat. Footprints were taken from 41 subjects using the footprinting mat. The images were subjected to analysis by three independent examiners. To investigate the intra-examiner reliability, the analysis was repeated by one of the examiners one week later. The weighted kappa coefficient was excellent (K(w) > 0.80) for the inter- and intra-examiner analyses for most of the points studied on both feet. The criteria for analyzing footprint patterns obtained using the Harris and Beath footprinting mat presented good reliability and high to excellent inter- and intra-examiner agreement. This method is reliable for analyses involving one or more examiners. Article registered in the Australian New Zealand Clinical Trials Registry (ANZCTR) under the number ACTRN12609000693224.
Characterization of chemosynthetic microbial mats associated with intertidal hydrothermal sulfur vents in White Point, San Pedro, CA, USA

Directory of Open Access Journals (Sweden)

Priscilla J Miranda

2016-07-01

Full Text Available The shallow-sea hydrothermal vents at White Point (WP in Palos Verdes (PV on the southern California coast support microbial mats and provide easily accessed settings in which to study chemolithoautotrophic sulfur cycling. Previous studies have cultured sulfur-oxidizing bacteria from the WP mats; however, almost nothing is known about the in situ diversity and activity of the microorganisms in these habitats. We studied the diversity, micron-scale spatial associations and metabolic activity of the mat community via sequence analysis of 16S rRNA and aprA genes, Fluorescence in situ Hybridization (FISH microscopy and sulfate-reduction rate (SRR measurements. Sequence analysis revealed a diverse group of bacteria, dominated by sulfur cycling gamma-, epsilon- and deltaproteobacterial lineages such as Marithrix, Sulfurovum and Desulfuromusa. FISH microscopy suggests a close physical association between sulfur-oxidizing and sulfur-reducing genotypes, while radiotracer studies showed low, but detectable, SRR. Comparative 16S rRNA gene sequence analyses indicate the WP sulfur vent microbial mat community is similar, but distinct from other hydrothermal vent communities representing a range of biotopes and lithologic settings. These findings suggest a complete biological sulfur cycle is operating in the WP mat ecosystem mediated by diverse bacterial lineages, with some similarity with deep-sea hydrothermal vent communities.
Effect of Furnish on Temperature and Vapor Pressure Behavior in the Center of Mat Panels during Hot Pressing

Directory of Open Access Journals (Sweden)

Muhammad Navis Rofii

2014-07-01

Full Text Available Particleboard achieves its overall performance characteristics during hot pressing process. As this process is influenced by several factors, particularly temperature and pressure, it is very important to understand the behavior of both. This study investigates the effects of furnish materials on temperature and vapor pressure behavior inside particleboard mat panels during hot pressing. Strand type particles from hinoki and ring-flaker recycled wood particles were used as furnish for laboratory-scale particleboard panels with a target density of 0.76 g/cm³. Mat panels with a moisture content of about 10% were hot pressed at a platen temperature of 180°C and an initial pressure of 3 MPa until the mat center reached the same temperature as the platen. A press monitoring device (PressMAN Lite was used for detecting the temperature and vapor pressure change in the center of the mat panels. The study showed that the furnish type affected the temperature and vapor behavior inside the mat panels. Particleboard made of hinoki strand resulted in a longer plateau time, a higher plateau temperature and a higher gas pressure generated during hot pressing than those of ring-flaker recycled wood particles. Mixed board resulted in values between those of the two other furnish materials.
Social yoga mats: reinforcing synergy between physical and social activity

DEFF Research Database (Denmark)

Nagargoje, Arun; Sokoler, Tomas; Maybach, Karl

2011-01-01

This paper discusses our early research into the design space for digital technologies that extend the existing synergistic relationship between physical and social activity from fitness centers to the home. We focus on yoga activity for senior citizens and explore the concept of social yoga mats...
Mechanisms of Mindfulness Training: Monitor and Acceptance Theory (MAT)1

Science.gov (United States)

Lindsay, Emily K.; Creswell, J. David

2016-01-01

Despite evidence linking trait mindfulness and mindfulness training with a broad range of effects, still little is known about its underlying active mechanisms. Mindfulness is commonly defined as (1) the ongoing monitoring of present-moment experience (2) with an orientation of acceptance. Building on conceptual, clinical, and empirical work, we describe a testable theoretical account to help explain mindfulness effects on cognition, affect, stress, and health outcomes. Specifically, Monitor and Acceptance Theory (MAT) posits that (1), by enhancing awareness of one’s experiences, the skill of attention monitoring explains how mindfulness improves cognitive functioning outcomes, yet this same skill can increase affective reactivity. Second (2), by modifying one’s relation to monitored experience, acceptance is necessary for reducing affective reactivity, such that attention monitoring and acceptance skills together explain how mindfulness improves negative affectivity, stress, and stress-related health outcomes. We discuss how MAT contributes to mindfulness science, suggest plausible alternatives to the account, and offer specific predictions for future research. PMID:27835764
Modular development mat reinforcing and liners containment/annulus building. Final report supplement. Volume I

International Nuclear Information System (INIS)

Wainrib, J.

1978-06-01

The feasibility of developing a modular system approach for the construction of containment mats has been established. The investigative results obtained from a plant used for the modular study has determined that (1) modularization results in a 10-week reduction in the construction schedule critical path over that for the conventional approach, and (2) modularization is cost effective and could result in a savings of approximately $10,700,000. Accordingly, it is recommended that the modular system approach be adopted as standard practice for the construction of containment mats
Community Structure and Activity of a Highly Dynamic and Nutrient-Limited Hypersaline Microbial Mat in Um Alhool Sabkha, Qatar

KAUST Repository

Al-Thani, Roda

2014-03-21

The Um Alhool area in Qatar is a dynamic evaporative ecosystem that receives seawater from below as it is surrounded by sand dunes. We investigated the chemical composition, the microbial activity and biodiversity of the four main layers (L1–L4) in the photosynthetic mats. Chlorophyll a (Chl a) concentration and distribution (measured by HPLC and hyperspectral imaging, respectively), the phycocyanin distribution (scanned with hyperspectral imaging), oxygenic photosynthesis (determined by microsensor), and the abundance of photosynthetic microorganisms (from 16S and 18S rRNA sequencing) decreased with depth in the euphotic layer (L1). Incident irradiance exponentially attenuated in the same zone reaching 1% at 1.7-mm depth. Proteobacteria dominated all layers of the mat (24%–42% of the identified bacteria). Anoxygenic photosynthetic bacteria (dominated by Chloroflexus) were most abundant in the third red layer of the mat (L3), evidenced by the spectral signature of Bacteriochlorophyll as well as by sequencing. The deep, black layer (L4) was dominated by sulfate reducing bacteria belonging to the Deltaproteobacteria, which were responsible for high sulfate reduction rates (measured using 35S tracer). Members of Halobacteria were the dominant Archaea in all layers of the mat (92%–97%), whereas Nematodes were the main Eukaryotes (up to 87%). Primary productivity rates of Um Alhool mat were similar to those of other hypersaline microbial mats. However, sulfate reduction rates were relatively low, indicating that oxygenic respiration contributes more to organic material degradation than sulfate reduction, because of bioturbation. Although Um Alhool hypersaline mat is a nutrient-limited ecosystem, it is interestingly dynamic and phylogenetically highly diverse. All its components work in a highly efficient and synchronized way to compensate for the lack of nutrient supply provided during regular inundation periods.
Metagenomic Assembly of the Dominant Zetaproteobacteria in an Iron-oxidizing Hydrothermal Microbial Mat

Science.gov (United States)

Moyer, C. L.; Fullerton, H.

2013-12-01

Iron is the fourth most abundant element in the Earth's crust and is potentially one of the most abundant energy sources on the earth as an electron donor for chemolithoautotrophic growth coupled to Fe(II) oxidation. Despite the rapid abiotic oxidation rate of iron, many microbes have adapted to feeding off this fleeting energy source. One such bacterial class is the Zetaproteobacteria. Iron-dominated microbial mat material was collected with a small-scale syringe sampler from Loihi Seamount, Hawaii. From this sample, gDNA was extracted and prepared for paired-end Illumina sequencing. Reconstruction of SSU rDNA genes using EMERGE allowed for comparison to previous SSU rDNA surveys. Clone libraries and qPCR show these microbial mats to be dominated by Zetaproteobacteria. Results from our in silico reconstruction confirm these initial findings. RDP classification of the EMERGE reconstructed sequences resulted in 44% of the community being identified as Zetaproteobacteria. The most abundant SSU rDNA has 99% similarity to Zeta OTU-2, and only a 94% similarity to M. ferrooxidans PV-1. Zeta OTU-2 has been shown to be the most cosmopolitan population in iron-dominated hydrothermal systems from across Pacific Ocean. Metagenomic assembly has resulted in many contigs with high identity to M. ferrooxidans as identified, by BLAST. However, with large differences in SSU rRNA similarity, M. ferrooxidans PV-1 is not an adequate reference. Current work is focusing on reconstruction of the dominant microbial mat member, without the use of a reference genome through an iterative assembly approach. The resulting 'pan-genome' will be compared to other Zetaproteobacteria (at the class level) and the functional ecology of this cosmopolitan microbial mat community member will be extrapolated. Thus far, we have detected multiple housekeeping genes involved in DNA replication, transcription and translation. The most abundant metabolic gene we have found is Aconitase, a key enzyme in the

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