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Sample records for agglutination test lat

  1. Development and evaluation of a latex agglutination test for the rapid serodiagnosis of tularemia.

    PubMed

    Rastawicki, Waldemar; Rokosz-Chudziak, Natalia; Chróst, Anna; Gierczyński, Rafał

    2015-05-01

    A latex agglutination test (LAT) was developed for a rapid detection of antibodies against Francisella tularensis. The assay is performed by mixing serum with antigen-coated latex beads and read within 5 min. Developed LAT has been proved to be a specific, sensitive, fast, easy-to-perform and cost-efficient tool for the routine diagnosis of tularemia.

  2. Column agglutination technology: the antiglobulin test.

    PubMed

    Reis, K J; Chachowski, R; Cupido, A; Davies, D; Jakway, J; Setcavage, T M

    1993-08-01

    A new system for typing and screening blood, based on the sieving effect of glass bead microparticles, has been developed. The test is performed in a microcolumn in which the red cell agglutinates are trapped in the glass bead matrix during centrifugation, and unagglutinated cells form a pellet at the bottom of the column. Anti-human globulin reagents were incorporated in the diluent and the new test system, column agglutination technology, was compared to conventional tube tests and low-ionic-strength method. Sera and plasmas (228 samples) were screened for red cell antibodies with two anti-human globulin reagents: one containing only anti-IgG and the other containing both anti-IgG and anti-C3b, -C3d. After initial testing, there was 94-percent agreement between column agglutination technology and tube tests, and after repeat testing, there was 97-percent agreement. The column agglutination technology anti-human globulin test eliminates the need to wash red cells, which decreases the overall test time. The test is easy to perform, and the results are more objective than those with tube and microplate methods.

  3. Development of a blocking latex agglutination test for the detection of antibodies to chicken anemia virus.

    PubMed

    Trinh, Dai Quang; Ogawa, Haruko; Bui, Vuong Nghia; Nguyen, Tham Thi Hong; Gronsang, Dulyatad; Baatartsogt, Tugsbaatar; Kizito, Mugimba Kahoza; AboElkhair, Mohammed; Yamaguchi, Shigeo; Nguyen, Viet Khong; Imai, Kunitoshi

    2015-09-01

    A blocking latex agglutination test (b-LAT) developed in this study was evaluated for the detection of antibodies against chicken anemia virus (CAV) in chickens. Polystyrene latex beads were coupled with a neutralizing monoclonal antibody (mAb) to CAV (mAb-beads). When mAb-beads were mixed with antigens prepared from the lysate of MDCC-MSB1 cells infected with CAV, agglutination occurred. A short pre-incubation of CAV antigens with CAV-specific antiserum inhibited the agglutination of mAb-beads. The test results were obtained within 5min. The specificity of b-LAT was evaluated using sera from specific pathogen-free chickens and sera containing antibodies to avian influenza virus, Newcastle disease virus, infectious bursal disease virus, and Marek's disease virus; nonspecific agglutination and cross-reactivity with antibodies to unrelated viruses were not observed. The examination of 94 serum samples collected from commercial breeder chickens of various ages (17-63 weeks) revealed good agreement (93.6%, Kappa value=0.82) between b-LAT and a virus neutralization test, known to be most sensitive and specific in the detection of antibodies to CAV. These results indicate that b-LAT, a simple and rapid test, is a useful and reliable tool in CAV serology.

  4. Development of a Specific Latex Agglutination Test to Detect Antibodies of Enterovirus 71.

    PubMed

    Qin, Bo; Zhang, Jianhua; Xie, Wenhao; Liu, Xuehong; He, Tingting; Chen, Jinkun; Dong, Xuejun

    2015-10-01

    A latex agglutination test (LAT) was developed for the rapid detection of antibodies against the VP1 or VP1 proteins of Enterovirus 71 (EV71). The proteins of interest including prokaryotically expressed VP1 and two strains of anti-VP1 monoclonal antibody (McAb) against EV71 were covalently linked to carboxylated latex using ethyl-dimethyl-amino-propyl carbodiimide (EDC) to prepare sensitized latex beads. LAT was evaluated by an enzyme-linked immunosorbent assay (ELISA) as a reference test. The VP1-LAT showed a sensitivity of 87.0%, specificity of 88.9%, and an agreement ratio of 90.0% in detecting VP1 in 100 serum samples from experimentally infected mice, whereas these values were 86.8, 96.7, and 93.3%, respectively, for 608 clinical human serum samples. The VP1-LAT has advantages over other assays in terms of low cost, rapidity, chemical stability, high sensitivity, repeatability, and specificity. The LAT established in the present study is a rapid and simple test suitable for field monitoring of antibodies against VP1-EV71. PMID:26363276

  5. Improving agglutination tests by working in microfluidic channels.

    PubMed

    Degré, G; Brunet, E; Dodge, A; Tabeling, P

    2005-06-01

    Latex agglutination tests are used for the diagnosis of diseases in man and animals. They are generally simple, cheap, and do not require sophisticated equipment, nor highly specialized skills. In this Technical Note, we put latex agglutination tests in a microfluidic format. The experiment is performed in PDMS (polydimethylsiloxane) microchannels, using streptavidin-coated superparamagnetic beads and a magnetic field. The target molecule is biotinylated protein A. By taking full advantage of the microfluidic conditions (scaling down of the detection volume and controlled action of the shear flow), we achieved an analytical sensitivity of 10 fmol l(-1)(several hundreds of fg ml(-1)) and a fast response (a few minutes) ; the test is also quantitative. Performances of agglutination tests can thus be improved by orders of magnitude by adapting them to a microfluidic format; this comes in addition to the usual advantages offered by this technology (integration, high throughput etc.).

  6. Latex agglutination using the periplasmic proteins antigen of Brucella melitensis is a successful, rapid, and specific serodiagnostic test for ovine brucellosis.

    PubMed

    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. PMID:27207442

  7. A rapid slide agglutination test for the diagnosis of neurocysticercosis in the rural health set up

    PubMed Central

    Biswas, Rakhi; Parija, Subhash Chandra

    2011-01-01

    Background: Simple and rapid latex-based diagnostic tests have been used for detecting specific antigens or antibodies in several diseases. Aims: The aim of the present study was to standardize and evaluate the latex agglutination test (LAT) for the detection of Taenia solium metacestode antigen in the cerebrospinal fluid (CSF) and serum for the diagnosis of neurocysticercosis (NCC). Settings and Design: The study was conducted at Department of Microbiology, Jawaharlal Institute of Post graduate medical education and research after obtaining informed consent from the study subjects. Materials and Methods: In the present study, CSF and serum samples were collected from clinically suspected NCC, CT/MRI proven cases of NCC, non-cysticercal central nervous system infection control and from healthy control subjects. CSF was not collected from healthy controls. Polyclonal antisera raised in rabbits against porcine T. solium metacestode complete homogenate antigen, was used in the LAT to detect the antigen in the specimens. Statistical Analysis Used: The statistical analysis was carried out using Epi Info. The sensitivity, specificity, positive predictive value, and negative predictive value of the LAT were calculated. Results: The LAT exhibited sensitivity of 64.7% and specificity of 85.7% with CSF samples and sensitivity of 52.08% and specificity of 96% with serum samples. Conclusions: Results of the present study shows that the LAT can be employed as a moderately sensitive and specific test for the detection of T. solium metacestode antigen in the CSF and serum specimens for the diagnosis of NCC in poorly equipped laboratories. PMID:23508849

  8. [The pretransfusion bedside agglutination test is not a "Gold Standard"].

    PubMed

    Levy, G

    2008-11-01

    ABO-incompatible transfusions remain frequent in Europe despite the technological progresses in relation with the potential number of human errors during the control procedures of the transfusion chain. The agglutination bedside-test is only one step of this chain and the amelioration of the security will be achieved by its replacement by an electronical check.

  9. Rapid Detection of Contagious Caprine Pleuropneumonia Using a Mycoplasma capricolum subsp. capripneumoniae Capsular Polysaccharide-Specific Antigen Detection Latex Agglutination Test

    PubMed Central

    March, J. B.; Gammack, C.; Nicholas, R.

    2000-01-01

    Latex microspheres (diameter, 8 μm) were coated with anti-Mycoplasma capricolum subsp. capripneumoniae polyclonal immunoglobulin G (IgG) antiserum (anti-F38 biotype). The coated microspheres, when used in a latex agglutination test (LAT), detected M. capricolum subsp. capripneumoniae antigen in the serum of goats with contagious caprine pleuropneumoniae (CCPP). Beads also agglutinated strongly in the presence of purified M. capricolum subsp. capripneumoniae capsular polysaccharide (CPS). Preabsorption of CPS-specific antibodies prior to coating of the beads removed agglutinating activity in the presence of M. capricolum subsp. capripneumoniae, strongly suggesting that CPS is the likely soluble antigen recognized by the test. In addition, the specificity of the LAT exactly mirrored that of an M. capricolum subsp. capripneumoniae CPS-specific monoclonal antibody (WM25): of the 8 other mycoplasma species tested, agglutination was observed only with bovine serogroup 7. The LAT detected all 11 strains of M. capricolum subsp. capripneumoniae examined in this study, with a sensitivity level of 2 ng of CPS, or the equivalent of 1.7 × 104 CFU, in a reaction volume of 0.03 ml of serum. With field sera from goats with CCPP, the results of the LAT exhibited a 67% correlation with the results of the currently used complement fixation test (CFT), with the main discrepancy in diagnosis resulting from the increased sensitivity of the LAT compared to that of CFT. This antigen-detection LAT should prove particularly useful in identifying animals in the earliest stages of CCPP and combines sensitivity and low cost with ease of application in the field, without the need for any specialist training or equipment. PMID:11060083

  10. Development and evaluation of a recombinant-glycoprotein-based latex agglutination test for rabies virus antibody assessment.

    PubMed

    Jemima, Ebenezer Angel; Manoharan, Seeralan; Kumanan, Kathaperumal

    2014-08-01

    The measurement of neutralizing antibodies induced by the glycoprotein of rabies virus is indispensable for assessing the level of neutralizing antibodies in animals or humans. A rapid fluorescent focus inhibition test (RFFIT) has been approved by WHO and is the most widely used method to measure the virus-neutralizing antibody content in serum, but a rapid test system would be of great value to screen large numbers of serum samples. To develop and evaluate a latex agglutination test (LAT) for measuring rabies virus antibodies, a recombinant glycoprotein was expressed in an insect cell system and purified, and the protein was coated onto latex beads at concentrations of 0.1, 0.25, 0.5, 0.75, and 1 mg/ml to find out the optimal concentration for coating latex beads. It was found that 0.5 mg/ml of recombinant protein was optimal for coating latex beads, and this concentration was used to sensitize the latex beads for screening of dog serum samples. Grading of LAT results was done with standard reference serum with known antibody titers. A total of 228 serum samples were tested, out of which 145 samples were positive by both RFFIT and LAT, and the specificity was found to be 100 %. In RFFIT, 151 samples were positive, the sensitivity was found to be 96.03 %, and the accuracy/concordance was found to be 97.39 %. A rapid field test-a latex agglutination test (LAT)-was developed and evaluated for rabies virus antibody assessment using recombinant glycoprotein of rabies virus expressed in an insect cell system.

  11. Evaluation of three commercial agglutination tests for the identification of Staphylococcus aureus.

    PubMed

    Pennell, D R; Rott-Petri, J A; Kurzynski, T A

    1984-10-01

    Three commercially available rapid slide agglutination tests for the identification of Staphylococcus aureus were evaluated with 354 recent clinical isolates (165 strains of S. aureus). The test results of two latex agglutination products, SeroSTAT Staph (Scott Laboratories, Inc.) and Staphylatex (American Micro Scan), and one hemagglutination product, Staphyloslide (BBL Microbiology Systems), were compared with the results of the tube coagulase test, which was read at 4 h (4-h tube coagulase test) and, if negative, again after overnight incubation at room temperature (24-h tube coagulase test). Discrepancies between agglutination and tube coagulase identifications were resolved by use of the thermonuclease, mannitol fermentation, and slide coagulase tests. All sensitivities, specificities, predictive values of a positive result, and predictive values of a negative result for the three agglutination tests were at least 98.8% and comparable with the 4-h tube coagulase test. Best results were obtained with the 24-h tube coagulase test, which yielded one false-negative and no false-positive tests. Agglutination identifications may be performed on organisms taken directly from a primary plate when sufficient growth is present. Kit agglutination procedures yield rapid and reliable identifications and are easy to perform. This study also demonstrates the usefulness of the 24-h tube coagulase test.

  12. Environmental Tests of the Flight GLAST LAT Tracker Towers

    SciTech Connect

    Bagagli, R.; Baldini, L.; Bellazzini, R.; Barbiellini, G.; Belli, F.; Borden, T.; Brez, A.; Brigida, M.; Caliandro, G.A.; Cecchi, C.; Cohen-Tanugi, J.; Angelis, A.De; Drell, P.; Favuzzi, C.; Fusco, P.; Gargano, F.; Germani, S.; Giglietto, N.; Giordano, F.; Goodman, J.; Himel, T.

    2008-03-12

    The Gamma-ray Large Area Space telescope (GLAST) is a gamma-ray satellite scheduled for launch in 2008. Before the assembly of the Tracker subsystem of the Large Area Telescope (LAT) science instrument of GLAST, every component (tray) and module (tower) has been subjected to extensive ground testing required to ensure successful launch and on-orbit operation. This paper describes the sequence and results of the environmental tests performed on an engineering model and all the flight hardware of the GLAST LAT Tracker. Environmental tests include vibration testing, thermal cycles and thermal-vacuum cycles of every tray and tower as well as the verification of their electrical performance.

  13. Comparison of two agglutination tests for differentiation between coagulase positive and coagulase negative staphylococci.

    PubMed

    Flesland, O

    1987-02-01

    Two agglutination tests, Monostaph (Bionor A/S, N-3700 Skien, Norway) and Staphaurex (Wellcome), for the identification of Staphylococcus aureus have been evaluated. Using the coagulase test as reference method both tests were equally reliable and in complete aggrement with the coagulase tube test when tested on 216 strains of Micrococcaceae.

  14. Rapid Detection of Contagious Bovine Pleuropneumonia by a Mycoplasma mycoides subsp. mycoides SC Capsular Polysaccharide-Specific Antigen Detection Latex Agglutination Test

    PubMed Central

    March, John B.; Kerr, Karen; Lema, Benedict

    2003-01-01

    A latex agglutination test (LAT) has been developed for the diagnosis of contagious bovine pleuropneumonia (CBPP). The latex microspheres were coated with MmmSC polyclonal immunoglobulin G antiserum and detected MmmSC antigen in the serum of cattle infected with CBPP and in growth medium containing MmmSC. The specific antigen recognizsed by this test appeared to be the capsular polysaccharide (CPS). The LAT recognized all 23 strains of MmmSC examined in this study, with a sensitivity level of 2 ng of CPS, or the equivalent of 5 × 103 CFU, in a reaction volume of 0.03 ml. Therefore, rapid identification of MmmSC cultures should be possible. Agglutination was also observed with the related goat pathogens and “Mycoplasma mycoides” cluster members Mycoplasma mycoides subsp. mycoides large colony biotype (four of six strains positive) and Mycoplasma mycoides subsp. capri (three of six strains positive), in agreement with the suggestion that these latter two mycoplasmas may in fact represent a single species (although collectively exhibiting two capsular serotypes). Comparisons in diagnosis with the complement fixation test (CFT) were made by using African field sera from CBPP-infected cattle. After 2 (or 3) min of incubation, the test detected 55% (or 61%) of CFT-positive sera and 29% (or 40%) of CFT-negative sera, with an overall correlation in diagnosis of 62% (or 61%). The rates for false-positive diagnoses made by using “known” CBPP-negative sera from the United Kingdom were 3 or 13% after 2 or 3 min of incubation, respectively. The data agree with previous findings that some CBPP CFT-negative misdiagnoses may occur due to “antibody eclipsing” by excess circulating antigen. The LAT combines low cost and high specificity with ease of application in the field, without the need for any specialist training or equipment. PMID:12626448

  15. [Use of a latex-agglutination test for determining anti-measles antibody titer].

    PubMed

    Aleksander, S K; Lukin, Iu V; Iuminova, N V; Krasnova, V P; Andzhaparidze, O G

    1995-01-01

    A new diagnostic agent for microtitration of antimeasles antibodies, making use of polyacrolein microspheres conjugated with purified measles virus has been developed. Parallel titration of blood sera of children and adults in latex agglutination test and in routine test (hemagglutination inhibition, passive hemagglutination, immunofluorescent tests) demonstrated a sufficient specificity of the new test, sensitivity compatible to that of hemagglutination inhibition, and correlation of the results of all tests.

  16. Cross-reactivity in Cryptococcus antigen latex agglutination test in two commercial kits.

    PubMed

    Tone, Kazuya; Umeda, Yoshiko; Makimura, Koichi

    2016-05-01

    This article presents an examination of the cross-reactivity of pathogenic fungi with Cryptococcus neoformans in two commercial Cryptococcus antigen latex agglutination tests performed across 39 fungal strains. Some fungi were newly indicated as Cryptococcus cross-reactive, and the two kits showed differences in cross-reactive fungi. PMID:26922300

  17. A microtitration agglutination test for detecting group E streptococcus infection in swine.

    PubMed

    Armstrong, C H; Wood, R L; Wessman, G E

    1982-04-01

    A microtitration agglutination test was developed and evaluated for detecting infection of swine with group E streptococci type IV, the most common causative agent of streptococcic lymphadenitis of swine. Whole cell agglutinogens representing group and type antigens of group E streptococci were tested in the microtitration agglutination test against reference antisera to Streptococcus groups A, B, C, D, E, F, G. H, K, L, M, N, O, P, Q, R, S and U, as well as specific antisera to types II, IV and V of group E. Group E specific agglutinogens were unsatisfactory in the microtitration agglutination test because of cross reactions with group P and U antisera and because of poor reproducibility of the test. Type specific agglutinogens of group E streptococci reacted only with their respective homologous antisera and not with any heterologous group antisera. None of the group E streptococci agglutinogens reacted with 52 normal swine sera. Agglutinogen made from group E streptococci type IV was selected for further evaluation in the microtitration agglutination test because group E streptococci types II and V are considered to be of minor importance in the etiology of streptococcic lymphadenitis of swine. Swine experimentally infected with a type IV strain developed significant titers in the microtitration agglutination test. All swine tested negative before exposure and seroconverted (titer >/=4) two to six weeks postexposure.The microtitration agglutination test was used by two different laboratories to test 187 duplicate samples of serum from infected swine. A total of 94.1% of the tests were read at either the same titer (48.1%) or a difference of not more than one dilution (46.0%) at the two laboratories. There was disagreement between the two laboratories in the test-positive test-negative status of 19 of the sera (10.2%). Titers of two of the sera differed by two dilutions (<4 at one laboratory and 8 at the other). The remaining 17 sera differed in titer by only one

  18. Characterization of two different agglutinators in the latex fixation test, occurring in normal human sera

    PubMed Central

    Klein, F.; Valkenburg, H. A.; Van Zwet, Theda L.; Lafeber, Geertruida J. M.

    1966-01-01

    Using a sensitive modification of the latex fixation test it is possible to detect a small agglutinating effect in about 60 per cent of normal human sera, after these have been heated for 30 minutes at 56°. This was shown to be caused by an IgM globulin with the properties of a rheumatoid factor. The factor is able to react with human IgG globulin and may represent an antibody to the IgG part of circulating antigen—antibody complexes. The heat treatment probably inactivates an inhibitor of the latex fixation reaction. In addition all normal human sera give an agglutination reaction with IgG coated latex at incubation temperatures of 37° or lower. It was shown that these reactions are caused by a thermolabile, non-reducible component with a sedimentation constant of about 10. This component is probably identical with the complement component C'1q. The agglutinating activity was found in the α2—β1 region after electrophoresis of untreated serum, but in the slow γ region after treatment of the serum with EDTA. This kind of agglutination may cause false positive reactions in latex tests which are carried out at 37° or less. ImagesFIG. 1FIG. 3 PMID:4160336

  19. Widal agglutination test − 100 years later: still plagued by controversy

    PubMed Central

    Olopoenia, L.; King, A.

    2000-01-01

    We review the significance of the Widal agglutination test in the diagnosis of typhoid fever. Over 100 years since its introduction as a serologic means of detecting the presence of typhoid fever, the Widal test continues to be plagued with controversies involving the quality of the antigens used and interpretation of the result, particularly in endemic areas. Areas of concern with clinical and laboratory significance discussed in this review include: the techniques of test performance, interpretation of results, limitation of the value of the test results in endemic typhoid areas, the quality of the antigens used, and alternative diagnostic tests.


Keywords: Widal agglutination test; typhoid fever PMID:10644383

  20. Evaluation of latex agglutination and microtube coagulase tests for detection of Staphylococcus aureus.

    PubMed

    Pourshadi, M; Klaas, J

    1984-09-01

    In a blind study, a latex agglutination test (Serostat Staphylococcus, Scott Laboratories) and a microtube coagulase test (Staphase, API) were evaluated for their ability to detect Staphylococcus aureus. Of 289 isolates of catalase-positive, gram-positive cocci, 122 were identified as S. aureus based on positive reactions in at least three of the following tests: tube coagulase, slide coagulase, DNase production, or anaerobic fermentation of mannitol. The latex agglutination test gave positive reactions for all S. aureus isolates and 10 (6%) non-S. aureus isolates. The slide coagulase test was positive for 121 S. aureus isolates and three (2%) non-S. aureus isolates. The microtube coagulase test detected 53, 90, and 98% of the S. aureus isolates after 2, 4, and 24 hr, respectively. In contrast, the conventional tube coagulase test detected 97% of the S. aureus isolates after 2 hr, and 98% after 4 and 24 hr. Two isolates of S. aureus gave negative tube coagulase reactions at 37 degrees C, but positive reactions at room temperature after 24 hr. The combination of tube and slide coagulase tests provided the most reliable results. The slide and tube coagulase tests gave more reliable results than the latex agglutination and microtube coagulase tests, respectively.

  1. Comparison of genomic and antimicrobial resistance features of latex agglutination test-positive and latex agglutination test-negative Staphylococcus aureus isolates causing bovine mastitis.

    PubMed

    Moser, A; Stephan, R; Corti, S; Johler, S

    2013-01-01

    The dairy industry suffers massive economic losses due to staphylococcal mastitis in cattle. The Staphaureux latex agglutination test (Oxoid, Basel, Switzerland) was reported to lead to negative results in 54% of bovine Staphylococcus aureus strains, and latex-negative strains are thought to be less virulent than Staphaurex latex-positive strains. However, comparative information on virulence and resistance profiles of these 2 groups of Staph. aureus is scarce. Our objective was to associate the latex agglutination phenotype of Staph. aureus strains isolated from bovine mastitis milk with data on clonal complexes, virulence genes, and antibiotic resistance to (1) determine the virulence profiles of the Staphaureux test positive and Staphaurex test negative groups, and (2) provide data needed to improve treatment of bovine mastitis and to identify potential vaccine targets. Seventy-eight Staph. aureus strains isolated from 78 cows on 57 Swiss farms were characterized. Latex agglutination was tested by Staphaureux kit, and resistance profiles were generated by disk diffusion. A DNA microarray was used to assign clonal complexes (CC) and to determine virulence and resistance gene profiles. By the Staphaureux test, 49% of the isolates were latex-positive and 51% were latex-negative. All latex-negative strains were assigned to CC151, whereas latex-positive strains were assigned to various clonal complexes, including CC97 (n=16), CC8 (n=10), CC479 (n=5), CC20 (n=4), CC7 (n=1), CC9 (n=1), and CC45 (n=1). Although the latex-negative isolates were susceptible to all antimicrobial agents tested, 24% of latex-positive isolates were classified as intermediate with regard to cefalexin-kanamycin and 13% were resistant to both ampicillin and penicillin. Microarray profiles of latex-negative isolates were highly similar, but differed largely from those of latex-positive isolates. Although the latex-negative group lacked several enterotoxin genes and sak, it exhibited significantly

  2. [Assessment of a commonly available latex particle agglutination test in rapid, bacteriologic cerebrospinal fluid diagnosis].

    PubMed

    Grubbauer, H M; Dornbusch, H J; Zobel, G; Thiel, W

    1988-01-01

    36 cerebrospinal fluid specimens (CSF) from patients with bacterial meningitis were tested for the presence of bacterial antigens with the "Slidex Meningite Kit" (Bio Merieux). This kit has latex particles coated with antibodies against hemophilus influenzae type B (Hib) streptococcus pneumoniae (SP) and neisseria meningitidis (NM) group A and C. With the LAT we could detect the bacterial antigens in 84% of bacterial meningitis cases, 23 of the 27 of Hib meningitis (85.2%), all of the 6 cases of SP meningitis (100%) and two of the three NM meningitis cases. The test is handicapped by the fact, that there is no antiserum against NM sero-group B, the main cause of NM meningitis in Austria. There were no false positive results with the LAT. False negative results were obtained in 19.2% of Hib and in one case of NM. Even under sufficient antibiotic therapy and with negative culture we could detect 9 Hib- and 1 NM-cases during the first 12-48 hours of therapy with this method. The LAT-Kit is a useful addition to standard methods of CSF examinations in bacterial meningitis. With the LAT a rapid bacteriological diagnosis is possible within 15 minutes. The Kit is also able to identify bacterial antigens even with negative culture and after initiation of antibiotic treatment. PMID:3133628

  3. The modified card agglutination test: an accurate tool for detecting anaplasmosis in Columbian black-tailed deer.

    PubMed

    Howarth, A; Hokama, Y; Amerault, T E

    1976-07-01

    Inoculation of susceptible calves confirmed that the modified card agglutination test accurately detected the anaplasmosis infection status of each of 35 Columbian black-tailed deer (Odocoileus hemionus columbianus). Anaplasma marginale, and specific antibodies, were demonstrated only in calves which received blood from deer that were positive by the card test. The modified card agglutination testing of deer serum was performed in the manner recommended for testing cattle serum with bovine-origin antigen and bovine serum factor.

  4. The evolution of pretransfusion testing: from agglutination to solid-phase red cell adherence tests.

    PubMed

    Plapp, F V; Sinor, L T; Rachel, J M

    1989-01-01

    Hospital transfusion services and blood centers still use manual hemagglutination tests for most of their serological procedures. Automation of hemagglutination reactions has proven to be difficult, primarily because hemagglutination lacks an objective endpoint which can be easily interpreted by inexpensive instruments. Alternatively, solid-phase red cell adherence assays for ABO cell and serum grouping, Rh typing, red cell and platelet antibody screening, red cell and platelet crossmatching, IgA deficiency screening, hepatitis B surface antigen, and HIV antibody screening have been developed. The performance of these assays compares favorably with current hemagglutination and enzyme immunoassay methods. All of these tests share a common objective endpoint of adherence or nonadherence of indicator red cells. This uniformity allows easy interpretation of results visually, spectrophotometrically, or by image analysis. The latter technique has the potential to revolutionize the reading and interpretation of all agglutination tests. Solid-phase red cell adherence tests in microplates are ideal for batch processing large numbers of specimens. However, adherence tests are not restricted to this format. Therefore, blood grouping dipsticks have been produced, which permit testing of individual blood samples even outside of the laboratory.

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

    PubMed Central

    Rodrigues, T.C.S.; Santos, A.L.Q.; Lima, A.M.C.; Gomes, D.O.; Cardoso, G.F.; Brites, V.L.C.

    2016-01-01

    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. PMID:27077089

  6. Serological diagnosis of brucellosis in water buffaloes (Bubalus bubalis): comparison among complement fixation, serum agglutination and rose bengal plate test.

    PubMed

    Mathias, L A; Pinto, A A

    1983-12-01

    The results of a comparative study among complement fixation (CFT), plate agglutination (PAT), tube agglutination (TAT) and Rose Bengal plate tests ( RBPT ) to the serodiagnosis of brucellosis in Indian buffaloes are reported. Sera from 212 buffaloes unvaccinated against brucellosis were examined and the CFT was able to reveal significant titres in sera with low agglutinating titres. From 109 sera which did not show agglutination titres in the PAT, four showed complement fixing titre greater than 1 in 200. All the positive sera to the RBPT gave complement fixing titre equal to or greater than 1 in 20. In sera that showed negative result to the RBPT the CFT was able to reveal relatively high titres. From 131 sera negative to the RBPT five showed complement fixing titres greater than 1 in 60.

  7. Agglutinated tests in post-Sturtian cap carbonates of Namibia and Mongolia

    NASA Astrophysics Data System (ADS)

    Bosak, T.; Lahr, D. J. G.; Pruss, S. B.; Macdonald, F. A.; Dalton, L.; Matys, E.

    2011-08-01

    Paleomagnetic data suggest that the early Cryogenian (Sturtian) glaciation extended to sea level at low latitude. The impact of this dramatic environmental change on biota, and the composition of ecosystems in the immediate aftermath of the Sturtian glaciation remain virtually unknown. Here we report the discovery of abundant agglutinated tests in organic-rich carbonates directly overlying Sturtian glacial deposits from two different paleocontinents: the Rasthof Formation of the Congo craton in northern Namibia and the Tsagaan Oloom Formation of the Dzabkhan terrane in Mongolia. The most abundant tests preserve morphological and compositional characters consistent with those found in at least two different families of modern lobose testate amoebae (Amoebozoa), a group of heterotrophic microbial eukaryotes. The presence of spatially and compositionally variable clay minerals, quartz and microcline on the test walls is a signature of widespread biological agglutination. The post-glacial fossil assemblages differ from the most common pre-Sturtian vase-shaped fossil testate amoebae, perhaps as a result of different preservational mechanisms or of the appearance of new forms after the glaciation. The apparent local abundance of eukaryotic body fossils in the post-Sturtian carbonates suggests that the Cryogenian limestones and dolostones may host a currently unexplored fossil record of modern eukaryotes.

  8. Seroprevalence of Mycoplasma pneumoniae in HIV-infected patients using a microparticle agglutination test.

    PubMed

    Shankar, Esaki Muthu; Kumarasamy, Nagalingeswaran; Balakrishnan, Pachamuthu; Vengatesan, A; Kownhar, Hayath; Solomon, Suniti; Rao, Usha Anand

    2006-06-01

    Mycoplasma pneumoniae is increasingly recognized as a common and important pathogen in community settings, and is responsible for various pulmonary and extrapulmonary conditions in the normal population. However, the seroepidemiology of acute M. pneumoniae infection in HIV-infected individuals is still unclear worldwide. This study examined the seroprevalence of antibodies to M. pneumoniae in HIV-infected patients admitted with respiratory complaints at a tertiary AIDS care centre in Chennai, India. A commercial gelatin microparticle agglutination test (Serodia-Myco II, Fujirebio) was used for the determination of antibodies against M. pneumoniae in acute serum specimens. Of the 200 HIV-infected patients with underlying pulmonary conditions tested, 34 (17 % positivity; 95 % CI 12-23 %) had antibodies specific to M. pneumoniae, while among the 40 patients with no underlying pulmonary symptoms, five (12.5 % positivity; 95 % CI 4-27 %) had evidence of anti-M. pneumoniae antibody. This shows that the incidence of M. pneumoniae seropositivity is greater in patients with underlying pulmonary complaints. Most positive titres were found in the age group 28-37 years in the symptomatic and symptom-free groups (64.7 and 60 %, respectively). The positive titres ranged from 40 to >20 480. High titres (> or =320) were found in 10 out of the 39 patients (25.6 %). This seroprevalence study reports a 16.2 % prevalence of M. pneumoniae infections in HIV-infected patients by a particle agglutination test.

  9. Development of a latex agglutination test with recombinant variant surface glycoprotein for serodiagnosis of surra.

    PubMed

    Rogé, S; Baelmans, R; Claes, F; Lejon, V; Guisez, Y; Jacquet, D; Büscher, P

    2014-10-15

    Serodiagnosis of surra is commonly performed with the CATT/Trypanosoma evansi direct agglutination test. This antibody detection test is based on lyophilised bloodstream form trypanosomes propagated in rats and presenting the predominant variant surface glycoprotein (VSG) RoTat 1.2 on their surface. Recently, the N-terminal fragment of VSG RoTat 1.2 has been expressed as a recombinant protein in the yeast Pichia pastoris and showed diagnostic potential in ELISA. This recombinant antigen has now been incorporated in a latex agglutination test, the rLATEX/T. evansi. In this study, we compared the diagnostic accuracy of rLATEX/T. evansi and CATT/T. evansi with immune trypanolysis (TL) as reference test on a total of 1717 sera from camels, horses, bovines, water buffaloes, dogs and sheep. The rLATEX/T. evansi displayed a slightly better agreement with TL than CATT/T. evansi (kappa [κ] respectively 0.84 and 0.72). The sensitivities of rLATEX/T. evansi (84.2%, 95% CI 80.8-87.1) and CATT/T. evansi (84.0%, 95% CI 80.6-87.0) were similar, but rLATEX/T. evansi was significantly more specific (97.7%, 95% CI 96.7-98.4) than CATT/T. evansi (89.4%; 95% CI 87.6-91.1). We consider the rLATEX/T. evansi an alternative for the CATT/T. evansi, with the advantage that the use of a purified recombinant antigen leads to a more standardised diagnostic test with an improved specificity. Moreover, it eliminates the use of laboratory animals and can be easily scaled-up, e.g. in biofermentors.

  10. Comparative evaluation of Rose Bengal plate agglutination test, mallein test, and some conventional serological tests for diagnosis of equine glanders.

    PubMed

    Naureen, Abeera; Saqib, Muhammad; Muhammad, Ghulan; Hussain, Muhammad H; Asi, Muhammad N

    2007-07-01

    The Rose Bengal plate agglutination test (RBT) was evaluated for the diagnosis of equine glanders, and its diagnostic efficiency was compared with that of mallein and other serological tests, including indirect hemagglutination test (IHAT), complement fixation test (CFT), and modified counter immunoelectrophoresis test (mCIET). Sera from 70 naturally infected culture-positive, 96 potentially exposed cohorts, and 110 healthy equines were tested. All tests but mCIET showed 100% specificity when testing the sera from glanders-negative equines. The calculated sensitivities of RBT, IHAT, CFT, mCIET, and mallein test when testing culture-positive equines were 90.0, 97.1, 91.4, 81.4, and 75.7%, respectively. The RBT was significantly (P < 0.05) more sensitive than the mallein test and mCIET. The positive and negative predictive values of each test (RBT, IHAT, CFT, mallein test, and mCIET) were as follows: 100 and 94, 100 and 98.2, 100 and 96.7, 100 and 86.6, and 90.5 and 88.6, respectively. On comparing glandered and nonglandered animals, the highest agreement (0.987) was found between RBT and CFT followed by RBT and IHAT (0.940), RBT and mallein test (0.871), and RBT and mCIET (0.852). Because the RBT is simpler and rapid to perform, the inclusion of the test as a supplementary test for the diagnosis of glanders in field conditions is recommended.

  11. Evaluation of six agglutination tests for Staphylococcus aureus identification depending upon local prevalence of meticillin-resistant S. aureus (MRSA).

    PubMed

    Weist, Klaus; Cimbal, Ann-Katrin; Lecke, Christoph; Kampf, Günter; Rüden, Henning; Vonberg, Ralf-Peter

    2006-03-01

    Most routine laboratory detection of Staphylococcus aureus isolates is based on rapid agglutination test systems. Failure of agglutination assays to identify meticillin-resistant S. aureus strains (MRSA) has been demonstrated. The aim of this study was to evaluate six commercially available agglutination tests for the detection of meticillin-sensitive S. aureus (MSSA) and mecA-positive MRSA strains. The Dry Spot Staphytect Plus test (Oxoid), the Pastorex Staph Plus test (Bio-Rad), the Slidex Staph-Kit and Slidex Staph Plus test (bioMérieux), the Staphaurex Plus test (Remel) and the Staphylase Test (Oxoid) were used. As determined by pulsed field gel electrophoresis, 52 distinct MRSA strains from five countries, 83 MSSA strains and 150 coagulase-negative staphylococci were included. Species identification and determination of susceptibility patterns were performed using colony morphology, Gram stain, catalase testing, tube coagulase testing, DNase testing, mannitol fermentation, susceptibility testing towards oxacillin by Etest, coagulase gene PCR, fibrinogen receptor gene PCR and PCR of the mecA gene. Sensitivity of the agglutination tests ranged from 82.7 to 100.0 % for MRSA strains and 92.8 to 100.0 % for MSSA strains, respectively. Specificity of the test systems ranged from 91.3 to 99.1 %. None of the six agglutination assays produced correct reactions for all staphylococci tested. Only the Dry Spot Staphytect Plus test correctly identified all 52 MRSA strains. For the other tests kits, sensitivity of MRSA detection was lower than for MSSA isolates. Depending upon the local MRSA prevalence and the parameter of interest (sensitivity or specificity), these test systems may be useful for routine diagnostic purposes.

  12. Seroprevalence of bovine leptospiral antibodies by microscopic agglutination test in Southeast of Iran

    PubMed Central

    Khalili, Mohammad; Sakhaee, Ehsanollah; Aflatoonian, Mohammad Reza; Abdollahpour, Gholamreza; Tabrizi, Saeed Sattari; Damaneh, Elham Mohammadi; Hossini-nasab, Sajad

    2014-01-01

    Objective To evaluate serological findings of bovine leptospirosis which is a zoonotic disease with worldwide distribution caused by Leptospira interrogans. Methods One hundred and sixty seven sera were collected from 9 commercial dairy herds in jiroft suburbs, from July to October 2011. Microscopic agglutination test (MAT) was used to evaluates serological findings of bovine leptospirosis in Jiroft suburb dairy farms, Kerman province, Iran. Results Antibodies were found by MAT at least against one serovar of Leptospira interrogans in 29 samples (17.36%) among 167 sera at a dilution 1:100 or higher, and Leptospira pomona was the most prevalent serovar. Positive titers against more than one serovar were detected in 6 sera of the positive samples. Conclusion This study is the first report of leptospirosis in Southeast Iran and showed that Leptospira pomona was the most and Leptospira icterohaemorrhagiae the least prevalent serovars in Southeast Iran. PMID:25182718

  13. Evaluation of a latex agglutination test (PYLOGEN) for the detection of Helicobacter pylori in stool specimens.

    PubMed

    Blanco, Silvia; Forné, Montse; Lacoma, Alicia; Prat, Cristina; Cuesta, Miguel Angel; Fuenzalida, Loreto; Viver, Josep Maria; Domínguez, Jose

    2009-04-01

    The aim of the study was to assess a new latex agglutination (LA) stool antigen assay (PYLOGEN; CerTest Biotec, Zaragoza, Spain) in the diagnosis of Helicobacter pylori infection and to monitor its eradication after treatment. The LA test has been approved for sale in Europe, and its approval from the US Food and Drug Administration is still pending. The individuals enrolled were classified into 3 groups of patients: Group 1 consisted of 38 patients who are H. pylori positive. The diagnosis of H. pylori infection was established if there was concordance between 2 test results (urea breath test [UBT], rapid urease test, and histopathologic study) or if the culture alone was positive. Patients with only 1 positive test were considered indeterminate and were excluded from the study. Group 2 comprised 9 patients without positive tests and who were considered to be H. pylori negative. Group 3 consisted of 57 patients who received eradication treatment. The sensitivity and specificity of the test were 78.9% and 100%, respectively. The results of the UBT of the patients were studied 6 weeks after eradication therapy. The sensitivity and specificity of the LA test relative to UBT for patients after treatment were 75% and 93.3%, respectively.

  14. Simple solutions to false results with plate/slide agglutination tests in diagnosis of infectious diseases of man and animals

    PubMed Central

    Saxena, Hari Mohan; Chothe, Shubhada; Kaur, Paviter

    2015-01-01

    We have developed a new Superagglutination test for serodiagnosis of infectious diseases. It differs from conventional plate/slide agglutination tests (PAT/SAT) by three additional steps: prior staining of serum antibody by adding a dye and addition of diluted biotinylated antiglobulin and avidin in sequence after mixing the antigen with the test serum. The new steps circumvent the problems of false positive and false negative results of PAT/SAT. In serodiagnosis of brucellosis, Superagglutination test had higher positive predictive value and specificity than Rose Bengal Plate Test (RBPT) and Standard Tube Agglutination Test (STAT) and higher negative predictive value and sensitivity than RBPT, STAT, ELISA and Complement Fixation Test (CFT).•Superagglutination is a simple, accurate and economic screening test for infections.•More specificity, sensitivity, positive & negative predictive value than RBPT, STAT.•More sensitivity, negative predictive value than ELISA and Complement Fixation Test. PMID:26844209

  15. Comparison of fluorescent antibody and microscopic agglutination testing for Leptospira in pregnant and nonpregnant cows.

    PubMed

    Rajeev, Sreekumari; Berghaus, Roy D; Overton, Michael W; Pence, Mel E; Baldwin, Charles A

    2010-01-01

    Serum and urine samples from 30 cows (15 pregnant and 15 nonpregnant) from each of 10 Georgia dairy herds (total cows = 300) were examined by microscopic agglutination testing (MAT) and direct fluorescent antibody testing (FAT), respectively. Seven of the 10 herds had at least 1 cow with a positive FAT, and all of the herds had at least 1 cow with a reciprocal MAT titer > or =100 for 1 or more serovars. Serological testing was not helpful in identifying the infecting serovar for cows with a positive FAT result. The MAT titers for all 7 of the serovars evaluated were significantly correlated with one another, with 17 (81%) of the 21 Spearman rank correlation coefficients > or =0.4 in magnitude. Twenty (56%) of 36 FAT-positive cows did not have a titer that was highest for any particular serovar. Four of the 7 herds that reported using a Leptospira borgpetersenii serovar Hardjo-bovis vaccine had one or more FAT-positive cows compared with 3 out of 3 herds that reported they were not using this type of vaccine, although this difference was not statistically significant.

  16. [Standardization of neutralization tests using the COBL cell line and comparison with the particle agglutination test for measles serology].

    PubMed

    Korukluoğlu, Gülay; Yalçinkaya, Tülay; Ozkaya, Etem; Kurtoğlu, Demet; Gözalan, Ayşegül; Miyamura, Kikuko

    2002-04-01

    The aim of the present study was the detection and comparison of measles antibody titers with particle agglutination (PA) and neutralization (Nt) methods, in the sera samples of 364 subjects from different age groups. PA method was performed with a commercial test kit (Serodiameasles, Fujirebio Com. Japan), and Nt test which was standardized in this study, by using COBL (cord blood) cell lines, has been started to use in our laboratory as a reference method. As a result, antibody titers detected by PA were in parallel to the titers which detected by Nt test, and it was concluded that the differences in antibody titers would arise from the differences of test principles and viral antigens.

  17. Typhoid fever in a Tertiary Hospital in Nigeria: Another look at the Widal agglutination test as a preferred option for diagnosis

    PubMed Central

    Enabulele, Osahon; Awunor, Simeon Nyemike

    2016-01-01

    Background: 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. Materials and Methods: 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. Results: 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. Conclusion: 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. PMID:27397952

  18. Evaluation of an Immunocapture-Agglutination Test (Brucellacapt) for Serodiagnosis of Human Brucellosis

    PubMed Central

    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

  19. Evaluation of latex agglutination tests for fibrin-fibrinogen degradation products in the forensic identification of menstrual blood.

    PubMed

    Akutsu, Tomoko; Watanabe, Ken; Motani, Hisako; Iwase, Hirotaro; Sakurada, Koichi

    2012-01-01

    The identification of menstrual blood is important when discriminating menstruation from vaginal trauma in sexual assault cases. The aim of this study was to evaluate two fibrin-fibrinogen degradation product (FDP)-latex agglutination test kits, FDPL® Test (FDP-L) and FDP Plasma "RD" (FDP-P), for their ability to forensically identify menstrual blood. Sensitivity and specificity of the two kits were compared for menstrual blood and various body fluids, and the sensitivity of the FDP-latex agglutination test kit was also compared with that of an immunochromatographic test for human hemoglobin. The robustness of the FDP-latex agglutination test was compared with that of gene expression analysis of menstrual blood specific markers. The FDP-L kit was more sensitive than the FDP-P kit, but it cross-reacted with peripheral bloodstains from healthy volunteers. The FDP-P kit was specific for menstrual blood, with the exception of postmortem blood samples, and was not affected by other body fluids. In an FDP-negative menstrual blood sample, the sensitivity of human hemoglobin detection was lower than for FDP-positive samples and peripheral blood stains, suggesting that determination of human hemoglobin could be useful in interpreting negative results in the FDP-latex agglutination test. In menstrual blood samples incubated in wet conditions, FDP was found to be a robust marker in the identification of menstrual blood compared with mRNA markers. FDP-P testing was shown to be a suitable and highly efficient rapid screening test for the laboratory identification of menstrual blood.

  20. Usefulness of PCR and Antigen Latex Agglutination Test with Samples Obtained by Transthoracic Needle Aspiration for Diagnosis of Pneumococcal Pneumonia

    PubMed Central

    García, Amparo; Rosón, Beatriz; Pérez, José Luis; Verdaguer, Ricard; Dorca, Jordi; Carratalà, Jordi; Casanova, Aurora; Manresa, Frederic; Gudiol, Francesc

    1999-01-01

    In a large number of cases, the etiology of community-acquired pneumonia (CAP) is not established. Some cases are probably caused by Streptococcus pneumoniae. Transthoracic needle aspiration (TNA) culture has a limited sensitivity which might be improved by antigen detection or gene amplification techniques. We evaluated the capacity of a PCR assay and a latex agglutination test to detect S. pneumoniae in samples obtained by TNA from 95 patients with moderate-to-severe CAP. Latex agglutination and PCR had sensitivities of 52.2 and 91.3%, specificities of 88.7 and 83.3%, positive predictive values of 62.3 and 65.6%, and negative predictive values of 83.3 and 96.5%, respectively, when culture techniques were used as the “gold standard.” When we considered expanded criteria for the diagnosis of pneumococcal pneumonia as a standard for our calculations, latex agglutination and PCR had sensitivities of 53.6 and 89.7%, specificities of 93.0 and 90.0%, positive predictive values of 78.9 and 81.3%, and negative predictive values of 80.3 and 94.7%, respectively. The additional diagnosis provided by the PCR assay compared to latex agglutination was 12.2% (95% confidence interval of the difference from 0.4 to 20.1%). PCR was more sensitive than TNA culture, particularly in patients who had received prior antibiotic therapy (83.3 versus 33.3%). Although PCR is a very sensitive and specific technique, it has not proved to be cost-effective in clinical practice. Conversely, latex agglutination is a fast and simple method whose results might have significant implications for initial antibiotic therapy. PMID:9986837

  1. Seroprevalence of Mycoplasma gallisepticum antibody by ELISA and serum plate agglutination test of laying chicken

    PubMed Central

    Ali, Md. Zulfekar; Rahman, Md. Mostafizer; Sultana, Shirin

    2015-01-01

    Aim: Mycoplasma gallisepticum (MG) is important avian pathogens responsible for chronic respiratory diseases 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). PMID:27046987

  2. 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

    PubMed Central

    Mohan, Anju; Saxena, Hari Mohan; Malhotra, Puneet

    2016-01-01

    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. PMID:27536032

  3. [Evaluation of commercial usefulness for microparticle agglutination Serodia-Myco II test for serodiagnosis of Mycoplasma pneumonia infections].

    PubMed

    Rastawicki, Waldemar; Kałuzewski, Stanisław; Jagielski, Marek; Gierczyński, Rafał

    2002-01-01

    The usefulness of Serodia-Myco II agglutination test (Fujirebio, Japan) for diagnosis of the M. pneumoniae infections was evaluated. A total of 66 serum samples obtained from patients with respiratory tract infections were tested by Serodia-Myco II test, complement fixation (CF) test, ELISA-IgG/-IgM, and by latex agglutination (LA) test prepared in our laboratory. Using CF test and ELISA as the reference tests, Serodia-Myco II test gave too many false positive results. This test in relation to CF test, ELISA-IgM, ELISA-IgG, and LA test showed a very high sensitivity, virtually 100%, with a low specificity, below 50%. It seems that oversensitivity of the Serodia-Myco II test is caused by too low cut off (40) value recommended by the manufacturer. The Serodia-Myco II test may be used in routine serodiagnosis of mycoplasmosis under condition that cut off value will be raised to 160 and the positive results of this test will be confirmed by the CF test or ELISA.

  4. Comparison of three commercial rapid agglutination test kits for identification of coagulase positive staphylococci from foods and animals.

    PubMed

    Holme, I J; Rosef, O; Ewald, S

    1991-01-01

    Three rapid agglutination assays for the identification of Staphylococcus aureus Monostaph (Bionor A/S, Skien, Norway), Staphyslide-Test (BioMerieux, Lyon, France) and Staph-Rapid-Test (Roche, Basel, Switzerland), were compared. A total of 104 Gram-positive, catalase positive cocci were tested: Nineteen Staphylococcus reference strains comprising 15 spp. (4 strains were coagulase positive), and 7 Micrococcus reference strains comprising 4 spp.; 22 food isolates comprising 13 S. aureus, 8 coagulase positive Staphylococcus spp., and 1 Micrococcus sp.; 56 animal isolates comprising 11 S. aureus, 9 S. hyicus subsp. hyicus, 2 S. intermedius, 15 coagulase positive and 19 coagulase negative Staphylococcus spp. Totally 54 strains were coagulase positive. Considering agglutination of a coagulase positive strain as a correct identification, Monostaph, Staph-Rapid-Test, and Staphyslide-Test correctly identified 52 (96.3%), 47 (87.0%) and 48 (89.0%) of the coagulase positive staphylococci, respectively. Monostaph, Staph-Rapid-Test and Staphyslide-Test showed 1 (2.0%), 4 (8.0%) and 4 (8.0%) false positive reactions respectively. Monostaph, Staph-Rapid-Test and Staphyslide-Test gave 0 (0.0%), 6 (5.8%) and 7 (6.7%) non-interpretable reactions, respectively. Monostaph may be a good alternative to the tube-coagulase test for rapid and reliable identification of coagulase positive staphylococci from both food and veterinary sources. However, false negative reactions may occur with coagulase positive strains of S. hyicus subsp. hyicus and S. intermedius.

  5. Improvement of a latex agglutination test for the evaluation of oxacillin resistance in coagulase-negative staphylococci.

    PubMed

    Corso, A; Soloaga, R; Faccone, D; Gagetti, P; Corbella, S; Iglesias, M; Galas, M

    2004-11-01

    The "Slidex MRSA Detection" test (Denka Seiken, Japan) is a latex agglutination assay able to detect PBP2a. We evaluated its ability to differentiate mecA-positive from mecA-negative coagulase-negative staphylococci. We included 100 coagulase-negative staphylococci clinical isolates belonging to 9 species, 54 mecA positive and 46 mecA negative, as characterized by PCR. The specificity achieved using the manufacturer's instructions was 100%, but the sensitivity was only 57%. To increase sensitivity, we introduced modifications into the standard protocol. Using either large inocula or oxacillin induction before test performance, we achieved 100% sensitivity.

  6. A prototype of the direct agglutination test kit (DAT-Canis) for the serological diagnosis of canine visceral leishmaniasis.

    PubMed

    Oliveira, Edward; Saliba, Juliana Wilke; Oliveira, Diana; Dias, Edelberto Santos; Paz, Gustavo Fontes

    2016-05-15

    This report describes the stege I/II development of a new direct agglutination test (DAT) for the diagnosis of canine visceral leishmaniasis (CVL) using freeze-dried antigen produced Coomassie blue-stained Leishmania (Leishmania) infantum promastigotes. In stage I, 16 canine serum samples, collected from eight dogs carrying CVL and eight healthy dogs, were assessed with the DAT using 2-mercaptoethanol (2-ME), N-acetyl-cysteine (NAC), kaolin or NAC plus urea (NAC+U) to improve the assay conditions. Stage II assessed the diagnostic accuracy with 100 serum samples collected from dogs with symptomatic CVL and clinically healthy dogs, comparing the four different sample diluents. The CVL-DAT prototype kit showed equivalent performances when 2-ME, NAC or NAC+U were used: 97.1% sensitivity (CI: 83-99.8%), 97% specificity (CI: 88.5-99.5%) and a 97% diagnostic accuracy (CI: 90.8-99.2). With kaolin, a 94.1% sensitivity (CI: 79-99%), 97% specificity (CI: 88.5-99.5%) and 96% diagnostic accuracy were observed (CI: 89.5-98.7), with no statistically significant differences among the four reagents (p=1.0). The NAC plus urea in sample diluent decreased non-specific agglutination, promoted a better defined sharp-edged blue spot and was thus chosen as a component for the new DAT prototype to diagnose canine VL, designated DAT-Canis.

  7. Diagnosis of Leptospirosis: Comparison between Microscopic Agglutination Test, IgM-ELISA and IgM Rapid Immunochromatography Test

    PubMed Central

    Niloofa, Roshan; Fernando, Narmada; de Silva, Nipun Lakshitha; Karunanayake, Lilani; Wickramasinghe, Hasith; Dikmadugoda, Nandana; Premawansa, Gayani; Wickramasinghe, Rajitha; de Silva, H. Janaka; Premawansa, Sunil; Rajapakse, Senaka; Handunnetti, Shiroma

    2015-01-01

    Background Leptospirosis is diagnosed on clinical grounds, and confirmed by microscopic agglutination test (MAT). IgM-ELISA (Serion-Virion) and immunochromatography test (Leptocheck-WB) are two immunodiagnostic assays for leptospirosis. Their sensitivity, specificity and applicability in Sri Lanka have not been systematically evaluated. Methods Clinically diagnosed leptospirosis patients (n = 919) were recruited from three hospitals in the Western Province of Sri Lanka, during June 2012 to December 2013. MAT, IgM-ELISA and Leptocheck-WB were performed on all patient sera. MAT titer of ≥400 in single sample, four-fold rise or seroconversion ≥100 in paired samples were considered as positive for MAT. For diagnostic confirmation, MAT was performed during both acute and convalescent phases. Anti-leptospiral IgM ≥20 IU/ml and appearance of a band in the test window were considered as positive for IgM-ELISA and Leptocheck-WB test respectively. Patients with an alternative diagnosis (n = 31) were excluded. Data analysis was performed using two methods, i) considering MAT as reference standard and ii) using Bayesian latent class model analysis (BLCM) which considers each test as imperfect. Results MAT, IgM-ELISA and Leptocheck-WB positivity were 39.8%, 45.8% and 38.7% respectively during the acute phase. Acute-phase MAT had specificity and sensitivity of 95.7% and 55.3% respectively, when compared to overall MAT positivity. IgM-ELISA and Leptocheck-WB had similar diagnostic sensitivity when compared with acute-phase MAT as the gold standard, although IgM-ELISA showed higher specificity (84.5%) than Leptocheck-WB (73.3%). BLCM analysis showed that IgM-ELISA and Leptocheck-WB had similar sensitivities (86.0% and 87.4%), while acute-phase MAT had the lowest sensitivity (77.4%). However, acute-phase MAT had high specificity (97.6%), while IgM-ELISA and Leptocheck-WB showed similar but lower specificity (84.5% and 82.9%). Conclusions Both IgM-ELISA and Leptocheck-WB shows

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

  9. Reverse-Transcriptase PCR Detection of Leptospira: Absence of Agreement with Single-Specimen Microscopic Agglutination Testing

    PubMed Central

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

    2015-01-01

    Background 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. Methods/Principal Findings 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%). Conclusions/Significance 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

  10. Prozone effects in microscopic agglutination tests for leptospirosis in the sera of mice infected with the pathogenic Leptospira interrogans serovar Canicola

    PubMed Central

    Shimabukuro, Fabio Hiroto; da Costa, Veruska Maia; da Silva, Rodrigo Costa; Langoni, Hélio; da Silva, Aristeu Vieira; de Carvalho, Lídia Raquel; Domingues, Paulo Francisco

    2013-01-01

    Mice experimentally infected with a pathogenic strain of Leptospira interrogans serovar Canicola produced false negative results (prozone effect) in a microscopic agglutination test (MAT). This prozone effect occurred in several serum samples collected at different post-infection times, but it was more prominent in samples collected from seven-42 days post-infection and for 1:50 and 1:100 sample dilutions. This phenomenon was correlated with increased antibody titres in the early post-infection phase. While prozone effects are often observed in serological agglutination assays for the diagnosis of animal brucellosis and human syphilis, they are not widely reported in leptospirosis MATs. PMID:23903987

  11. Environmental Test Activity on the Flight Modules of the GLAST LAT Tracker

    SciTech Connect

    Brigida, M.; Caliandro, A.; Favuzzi, C.; Fusco, P.; Gargano, F.; Giglietto, N.; Giordano, F.; Loparco, F.; Marangelli, B.; Mazziotta, M.N.; Mirizzi, N.; Raino, S.; Spinelli, P.; /Bari U. /INFN, Bari

    2007-02-15

    The GLAST Large Area Telescope (LAT) is a gamma-ray telescope consisting of a silicon micro-strip detector tracker followed by a segmented CsI calorimeter and covered by a segmented scintillator anticoincidence system that will search for {gamma}-rays in the 20 MeV-300 GeV energy range. The results of the environmental tests performed on the flight modules (towers) of the Tracker are presented. The aim of the environmental tests is to verify the performance of the silicon detectors in the expected mission environment. The tower modules are subjected to dynamic tests that simulate the launch environment and thermal vacuum test that reproduce the thermal gradients expected on orbit. The tower performance is continuously monitored during the whole test sequence. The environmental test activity, the results of the tests and the silicon tracker performance are presented.

  12. Comparison of indirect fluorescent antibody test and modified agglutination test for detecting Toxoplasma gondii immunoglobulin G antibodies in dog and cat.

    PubMed

    Macrì, Gladia; Sala, Marcello; Linder, Alicia M; Pettirossi, Nadia; Scarpulla, Manuela

    2009-07-01

    The present study describes the comparison between a modified agglutination test (MAT) and the indirect fluorescent antibody test (IFAT) for the detection of Toxoplasma specific IgG antibodies in dog and cat sera. MAT showed an "almost perfect" agreement with IFAT in detecting positive and negative results in cat sera, where as only a "substantial" agreement was observed in dog sera due to false negative results. Differences relative to sample dilution were recorded and serological titres obtained by MAT and IFAT are not directly comparable in cat and dog sera.

  13. Particle agglutination test "Serodia HIV-1/2" as a novel anti-HIV-1/2 screening test: comparative study on 3311 serum samples.

    PubMed

    Poljak, M; Zener, N; Seme, K; Kristancic, L

    1997-01-01

    Enzyme immunoassays are most widely used screening tests for antibodies to human immunodeficiency viruses (HIV). Nevertheless, the need of simpler, noninstrumented tests is evident in many parts of the world, where laboratory facilities and trained personnel are limited, and HIV incidence is high. A recently developed variant of gelatin-particle agglutination tests, Serodia HIV-1/2 (Fujirebio Inc., Tokyo, Japan), is one of such simple and noninstrumented tests. To evaluate its utility, 3311 serum samples (281 anti-HIV-1 positive, 8 anti-HIV-2 positive and 3022 anti-HIV-1/2 negative) obtained from 2632 individuals from Slovenia, other parts of former Yugoslavia and Senegal were investigated. No false-negative results and only one false-positive result were obtained during the procedures, giving overall sensitivity and specificity of the particle agglutination test of 100% and 99.97%, respectively. We have concluded that Serodia HIV-1/2 test is highly specific and sensitive for detection of anti-HIV-1/2 antibodies, suitable for small blood banks and for epidemiological surveys.

  14. Rose Bengal plate agglutination and counterimmunoelectrophoresis tests on spinal fluid in the diagnosis of Brucella meningitis.

    PubMed Central

    Díaz, R; Maraví-Poma, E; Delgado, G; Rivero, A

    1978-01-01

    Rose Bengal and counterimmunoelectrophoresis, two tests that detect antibodies against different structural antigens, when carried out on spinal fluid permitted rapid diagnosis of human Brucella meningitis. The Rose Bengal test was positive in five out of five patients studied, and counterimmunoelectrophoresis was positive in all but one. The Brucella meningitis was characterized by an increase of immunoglobulin G in the cerebrospinal fluid. PMID:632350

  15. Evaluation of a rapid strip and a particle agglutination tests for syphilis diagnosis.

    PubMed

    Juárez-Figueroa, Luis; Uribe-Salas, Felipe; García-Cisneros, Santa; Olamendi-Portugal, María; Conde-Glez, Carlos J

    2007-10-01

    The availability of new diagnostic approaches, which are easier and faster to perform than conventional tests, offers the opportunity to improve the attention given to public health problems as syphilis. This study aimed to evaluate a rapid immunochromatographic strip test (Determine TP; Abbott Laboratories, Chicago, IL) and a nonequipment demanding particle microagglutination test (Serodia TP-PA; Fujirebio, Japan) for qualitative detection of treponemic antibodies. Sera from 548 women belonging to 3 population groups were tested; one of them showing low syphilis seroprevalence (1.5%) and the other 2 showing higher seroprevalences (>15%). By comparison with the gold standard (Venereal Disease Research Laboratories plus fluorescent treponemal antibody absorption), sensitivity and specificity values for both diagnostic tests were calculated. Sensitivity values of both tests evaluated were higher than 95% for 2 groups of 3 addressed; in one of the high syphilis prevalence groups, Serodia TP-PA showed 88.6% sensitivity. Specificity values were above 95% for all 3 groups. The use of simple/rapid treponemic tests as those included here may prove to be a suitable replacement for the traditional syphilis serology diagnosis approach, particularly at primary care settings.

  16. Collaborative evaluation of antigen detection by a commercial latex agglutination test and enzyme immunoassay in the diagnosis of invasive candidiasis.

    PubMed Central

    Lemieux, C; St-Germain, G; Vincelette, J; Kaufman, L; de Repentigny, L

    1990-01-01

    The Cand-Tec Candida detection system and enzyme immunoassay for serum mannan were retrospectively compared in a controlled collaborative evaluation of antigen detection in 32 patients with candidiasis proven by biopsy or culture from a normally sterile site and with sera drawn within 7 days of inclusion. With a threshold titer of 1/8, which excluded false-positive results in 17 hospitalized patients without candidiasis, sensitivities for all 32 patients with candidiasis were 44% for the Cand-Tec assay and 17% for the enzyme immunoassay. Both assays provided greater sensitivity when sera were drawn within 24 h of inclusion in the study and in the category of patients with invasive candidiasis (57% by Cand-Tec and 33% by enzyme immunoassay). The Cand-Tec assay gave false-positive results (titer, greater than or equal to 1/8) in 4 of 6 patients with transient candidemia, in 1 of 20 otherwise healthy patients with rheumatoid factor, and in 1 patient with a positive cryptococcal latex agglutination test. Three serum specimens from 3 of 32 patients with candidiasis contained rheumatoid factor and gave titers of greater than or equal to 1/8 by the Cand-Tec assay. Detection of serum mannan by enzyme immunoassay was less sensitive but more specific than the Cand-Tec Candida detection system for the diagnosis of invasive candidiasis. PMID:2179258

  17. Detection of enterotoxigenic Clostridium perfringens in food and fecal samples with a duplex PCR and the slide latex agglutination test.

    PubMed Central

    Fach, P; Popoff, M R

    1997-01-01

    A duplex PCR procedure was evaluated for the detection of Clostridium perfringens in food and biological samples and for the identification of enterotoxigenic strains. This method uses two sets of primers which amplify in the same reaction two different DNA fragments simultaneously: the 283-bp C. perfringens phospholipase C gene fragment and the 426-bp enterotoxin gene fragment. Internal primers within the two primer sets confirmed the specificity of the method by DNA-DNA hybridization with the PCR products. No cross-reaction was observed with other Clostridium species or with other bacteria routinely found in food. The detection level was approximately 10(5) C. perfringens cells per g of stool or food sample. When overnight enrichment culture was used, 10 C. perfringens cells per g was detected in 57 artificially contaminated food samples. The duplex PCR is a rapid, sensitive, and reliable method for the detection and identification of enterotoxigenic C. perfringens strains in food samples. A slide latex agglutination test was also evaluated as a rapid, simple technique for the detection of C. perfringens enterotoxin in stool samples. PMID:9361409

  18. A novel agglutination test for antigen-specific detection of platelet antibodies.

    PubMed

    Meyer, Oliver; Agaylan, Ashraf; Borchert, Hans-Hubert; Aslan, Tunay; Bombard, Stéphane; Kiesewetter, Holger; Salama, Abdulgabar

    2006-10-15

    A simple and rapid antigen-specific assay for the identification antibodies to platelets is lacking, yet. Red-dyed polystyrene microbeads were coated with monoclonal antibodies to various platelet glycoprotein complexes, and used for the detection of platelet autoantibodies and alloantibodies. The results were largely identical with those obtained by monoclonal antibody-specific immobilization of platelet antigen assay (MAIPA). The new test is reliable yet less complex and time-consuming than the currently available assays, and it can be implemented in any routine laboratory. PMID:16933262

  19. Selective mineral composition, functional test morphology and paleoecology of the agglutinated foraminiferal genus Colominella Popescu, 1998 in the Mediterranean Pliocene (Liguria, Italy)

    NASA Astrophysics Data System (ADS)

    Nicoletta, Mancin; Elena, Basso; Camilla, Pirini; Michael A., Kaminski

    2012-12-01

    Specimens of Colominella (agglutinated Foraminifera) from a Pliocene Mediterranean succession were analysed through a scanning electron microscope (SEM) equipped with an energy-dispersive X-ray spectrometer (EDX) to document their test microstructure. Colominella develops a complex large test with a mostly biserial chamber arrangement, but with the internal chamber lumens partitioned by vertical and horizontal plates that form a labyrinthine structure of alcoves. This internal partition occurs from the first chambers but is completely masked from the outside by the thick wall. The test-wall microstructure is characterized by canaliculi (parapores) that are externally covered by a pavement of agglutinated grains. The mineralogical characterization of the agglutinated grains and the secreted cement shows that the grains are strongly selected as regards to size, arrangement and composition, with the coarse grains placed close to the outer wall. Moreover, these coarse grains, forming a pavement, are made of monocrystalline quartz, whereas the inner part of the skeleton is mostly composed of dolomite. The carbonate cement is less abundant and appears as cloudy light grey areas among the detrital grains. These shell features can be interpreted as functional adaptations to perform kleptoplastidy and/or to house functional photosymbionts, probably induced by stable environmental conditions as in warm shallow waters characterized by low nutrient flux.

  20. Traces of dissolved particles, including coccoliths, in the tests of agglutinated foraminifera from the Challenger Deep (10,897 m water depth, western equatorial Pacific)

    NASA Astrophysics Data System (ADS)

    Gooday, A. J.; Uematsu, K.; Kitazato, H.; Toyofuku, T.; Young, J. R.

    2010-02-01

    We examined four multilocular agglutinated foraminiferan tests from the Challenger Deep, the deepest point in the world's oceans and well below the depth at which biogenic and most detrital minerals disappear from the sediment. The specimens represent undescribed species. Three are trochamminaceans in which imprints and other traces of dissolved agglutinated particles are visible in the orange or yellowish organic test lining. In Trochamminacean sp. A, a delicate meshwork of organic cement forms ridges between the grain impressions. The remnants of test particles include organic structures identifiable as moulds of coccoliths produced by the genus Helicosphaera. Their random alignment suggests that they were agglutinated individually rather than as fragments of a coccosphere. Trochamminacean sp. C incorporates discoidal structures with a central hole; these probably represent the proximal sides of isolated distal shields of another coccolith species, possibly Hayaster perplexus. Imprints of planktonic foraminiferan test fragments are also present in both these trochamminaceans. In Trochamminacean sp. B, the test surface is densely pitted with deep, often angular imprints ranging from roughly equidimensional to rod-shaped. The surfaces are either smooth, or have prominent longitudinal striations, probably made by cleavage traces. We presume these imprints represent mineral grains of various types that subsequently dissolved. X-ray microanalyses reveal strong peaks for Ca associated with grain impressions and coccolith remains in Trochamminacean sp. C. Minor peaks for this element are associated with coccolith remains and planktonic foraminiferan imprints in Trochamminacean sp. A. These Ca peaks possibly originate from traces of calcite remaining on the test surfaces. Agglutinated particles, presumably clay minerals, survive only in the fourth specimen (' Textularia' sp.). Here, the final 4-5 chambers comprise a pavement of small, irregularly shaped grains with flat

  1. Latex agglutination test

    MedlinePlus

    ... antigens in a variety of body fluids including saliva, urine, cerebrospinal fluid, or blood. ... depends on what type of sample is needed. Saliva Urine Blood Cerebrospinal fluid ( lumbar puncture ) The sample ...

  2. Comparative assessment of the leprosy antibody absorption test, Mycobacterium leprae extract enzyme-linked immunosorbent assay, and gelatin particle agglutination test for serodiagnosis of lepromatous leprosy.

    PubMed Central

    Escobar-Gutiérrez, A; Amezcua, M E; Pastén, S; Pallares, F; Cázares, J V; Pulido, R M; Flores, O; Castro, E; Rodríguez, O

    1993-01-01

    A comparative assessment of three serological methods for leprosy diagnosis (the fluorescent leprosy antibody absorption [FLA-ABS] test, the Mycobacterium leprae soluble-extract enzyme-linked immunosorbent assay [ELISA], and the M. leprae particle agglutination [MLPA] test) was carried out. The objective was to identify their performance in clinical and epidemiological diagnosis of leprosy. The study group included 45 lepromatous leprosy patients under treatment. Specificity was > 95% for all three assays, and sensitivity was 95, 58, and 74% for the FLA-ABS test, the MLPA test, and the ELISA, respectively. The only cross-reactivity for M. tuberculosis-infected patients was with the soluble-extract ELISA. Although the FLA-ABS test displayed the highest specificity and sensitivity values, it can only be used in well-developed laboratories, and the patient's clinical and epidemiological background must be considered when results are interpreted because the test remains positive after therapeutic success and could be positive for some household contacts. The MLPA test is easier to perform and interpret, and it is adequate for small laboratories and epidemiological studies intended to detect active untreated or irregularly treated leprosy cases. Therefore, the FLA-ABS and MLPA tests are complementary, and both should be used for serodiagnosis of leprosy. PMID:8501238

  3. Rapid identification of Streptococcus pneumoniae in blood cultures by using the ImmuLex, Slidex and Wellcogen latex agglutination tests and the BinaxNOW antigen test.

    PubMed

    Altun, O; Athlin, S; Almuhayawi, M; Strålin, K; Özenci, V

    2016-04-01

    Rapid identification of Streptococcus pneumoniae in blood culture (BC) bottles is important for early directed antimicrobial therapy in pneumococcal bacteraemia. We evaluated a new latex agglutination (LA) test on BC bottles, the ImmuLex™ S. pneumoniae Omni (Statens Serum Institut, Denmark), and compared the performance with the Slidex® pneumo-Kit (bioMérieux, France) and the Wellcogen™ S. pneumoniae (Remel, UK) LA tests, as well as the BinaxNOW® S. pneumoniae (Alere, USA) antigen test. The four tests were directly applied on 358 positive BC bottles with Gram-positive cocci in pairs or chains and on 15 negative bottles. Valid test results were recorded in all cases for ImmuLex and BinaxNOW and in 88.5 % (330/373) and 94.1 % (351/373) of cases for Slidex and Wellcogen, respectively. Based on bottles positive for S. pneumoniae by conventional methods, the sensitivity of ImmuLex was 99.6 %, similar to the other tests (range, 99.6-100 %). Based on bottles positive for non-pneumococcal pathogens, the specificity of ImmuLex was 82.6 %, in comparison to 97.6 % for Slidex (p < 0.01) and 85.4 % for Wellcogen (p = ns). The BinaxNOW test had a lower specificity (64.1 %) than any LA test (p < 0.01). On BC bottles positive for α-haemolytic streptococci, ImmuLex was positive in 12/67 (17.9 %) cases, Slidex in 2/59 (3.4 %) cases, Wellcogen in 11/64 (17.2 %) cases and BinaxNOW in 25/67 (37.3 %) cases. In conclusion, the ImmuLex test provides a valid and sensitive technique for the rapid detection of S. pneumoniae in BC bottles, similar to the other compared methods. However, the specificity was sub-optimal, since the test may cross-react with other Gram-positive bacteria. PMID:26796552

  4. Sero-epidemiology of equine toxoplasmosis using a latex agglutination test in the three metropolises of Punjab, Pakistan.

    PubMed

    Saqib, M; Hussain, M H; Sajid, M S; Mansoor, M K; Asi, M N; Fadya, A A K; Zohaib, A; Sial, A U R; Muhammad, G; Ullah, I

    2015-06-01

    Toxoplasmosis is a serious threat for livestock in addition to being of zoonotic significance. In this study, serodiagnosis of equine toxoplasmosis was conducted in a randomly selected population from the 3 metropolises of Punjab, Pakistan. To this end, 272 draught equines were screened using a commercial latex agglutination assay kit. Association of probable risk factors of equine toxoplasmosis was also documented. A total of 91 (33.5%) equines were found sero-positive for Toxoplama (T.) gondii having antibody titers ranging between 1:32 to 1:612. The highest rates of seropositive cases were observed in donkeys (58.7%) followed by mules (28.6%) and horses (23.5%). Age, sex and species of draught equines were found not to be statistically (p>0.05) associated with the distribution of T. gondii antibodies. The results of the study provided a baseline data for the exposure of equine population in this area. In addition, it is recommended that the contiguous population of domestic ruminants and possible reservoirs such as feral cats should be screened in order to explore the potential risk for the human population in Pakistan.

  5. Usefulness of the rK39-Immunochromatographic Test, Direct Agglutination Test, and Leishmanin Skin Test for Detecting Asymptomatic Leishmania Infection in Children in a New Visceral Leishmaniasis Focus in Amhara State, Ethiopia

    PubMed Central

    Gadisa, Endalamaw; Custodio, Estefanía; Cañavate, Carmen; Sordo, Luis; Abebe, Zelalem; Nieto, Javier; Chicharro, Carmen; Aseffa, Abraham; Yamuah, Lawrence; Engers, Howard; Moreno, Javier; Cruz, Israel

    2012-01-01

    In areas where visceral leishmaniasis is anthroponotic, asymptomatically infected patients may play a role in transmission. Additionally, the number of asymptomatic patients in a disease-endemic area will also provide information on transmission dynamics. Libo Kemkem and Fogera districts (Amhara State, Ethiopia) are now considered newly established areas to which visceral leishmaniasis is endemic. In selected villages in these districts, we conducted a study to assess the usefulness of different approaches to estimate the asymptomatic infection rate. Of 605 participants, the rK39 immunochromatographic test was able to detect asymptomatic infection in 1.5% (9 of 605), direct agglutination test in 5.3% (32 of 605), and leishmanin skin test in 5.6% (33 of 589); the combined use of serologic methods and leishmanin skin test enabled detecting asymptomatic infection in 10.1% (61 of 605). We conclude that the best option to detect asymptomatic infection in this new visceral leishmaniasis–endemic focus is the combined use of the direct agglutination test and the leishmanin skin test. PMID:22556076

  6. Evaluation of the card agglutination test (CATT/T. evansi) for detection of Trypanosoma evansi infection in water buffaloes (Bubalus bubalis) in Egypt.

    PubMed

    Hilali, M; Abdel-Gawad, A; Nassar, A; Abdel-Wahab, A; Magnus, E; Büscher, P

    2004-05-01

    A card agglutination test (CATT/T. evansi) was evaluated for detection of antibodies against Trypanosoma evansi (T. evansi) in experimentally and naturally infected buffaloes. Four calves were inoculated with a strain of T. evansi isolated from a dromedary camel. Parasitological examination of the calves revealed trypanosomes in the blood from days 4 to 9 post-inoculation (PI). General emaciation appeared from day 26 PI and aggravated until the end of the experiment (day 88 PI). Antibodies against T. evansi were detectable from day 8 PI till the end of the experiment. Parasitological examination of 200 water buffalo blood samples obtained from slaughterhouses revealed negative results. Serological examination of these animals showed that 48 (24%) water buffaloes had anti-T. evansi antibodies. PMID:15110402

  7. Evaluation of the card agglutination test (CATT/T. evansi) for detection of Trypanosoma evansi infection in water buffaloes (Bubalus bubalis) in Egypt.

    PubMed

    Hilali, M; Abdel-Gawad, A; Nassar, A; Abdel-Wahab, A; Magnus, E; Büscher, P

    2004-05-01

    A card agglutination test (CATT/T. evansi) was evaluated for detection of antibodies against Trypanosoma evansi (T. evansi) in experimentally and naturally infected buffaloes. Four calves were inoculated with a strain of T. evansi isolated from a dromedary camel. Parasitological examination of the calves revealed trypanosomes in the blood from days 4 to 9 post-inoculation (PI). General emaciation appeared from day 26 PI and aggravated until the end of the experiment (day 88 PI). Antibodies against T. evansi were detectable from day 8 PI till the end of the experiment. Parasitological examination of 200 water buffalo blood samples obtained from slaughterhouses revealed negative results. Serological examination of these animals showed that 48 (24%) water buffaloes had anti-T. evansi antibodies.

  8. Application of latex beads agglutination test for the detection of the antibody against virus-infection-associated (VIA) antigen of foot-and-mouth disease (FMD) virus.

    PubMed

    Sugimura, T; Suzuki, T; Chatchawanchonteera, A; Sinuwonkwat, P; Tsuda, T; Murakami, Y

    2000-07-01

    Latex beads agglutination (LA) for the detection of the antibody against virus infection-associated (VIA) antigen of foot-and-mouth disease (FMD) virus was estimated using experimentally infected animals. The VIA antibody titer by the LA test were compared with the neutralization titer and the titer by agarose gel diffusion (AGD) test, which has been used as a standard method for VIA antibody titration. The latex beads were coated with VIA antigen in carbonate buffer solution (0.5 M, pH 9.6) for the test. The sensitivity of the LA test was clearly higher than that of the AGD test in the results for cattle and swine infected experimentally. The antibody was detected in the bovine serum obtained at the 13th week after inoculation by the LA but not by the AGD test. The LA test appears to be simple, rapid and sensitive for the detection of the antibody of FMD virus in the surveillance of FMD and the FMD quarantine of imported animals.

  9. Validation of the modified agglutination test for the detection of Toxoplasma gondii in free-range chickens by using cat and mouse bioassay.

    PubMed

    Dubey, J P; Laurin, E; Kwowk, O C H

    2016-03-01

    The modified agglutination test (MAT) is one of the most commonly used tests for the detection of antibodies to Toxoplasma gondii in animal and human sera. The objective of the present study was to evaluate the diagnostic accuracy of the MAT and bioassay in free-range/backyard (FR) chickens (Gallus domesticus). Previously-published T. gondii test results from 2066 chickens from 19 countries were compiled for the present study. The frequency of isolation of T. gondii increased for MAT titres between 1:5 and 1:160, and ranged from 61 to 75% for antibody titres of 1:160, 1:320, and ⩾1:640. Twenty-three cats fed pooled hearts from a total of 802 FR seronegative (MAT, <1:5) chickens from several countries did not excrete oocysts, indicating a high negative predictive value of MAT because FR chickens would have been exposed to many microbes; cats are the most sensitive indicators of T. gondii infection in tissues and can excrete millions of oocysts after ingesting even a few bradyzoites. Of the 29 cats in this study, six cats, fed hearts pooled from 15-122 FR chickens, excreted oocysts; but these identifications were likely related to misidentification or prozone. Results of the present study support the validity of MAT for the detection of T. gondii infection in chickens.

  10. Performance of rK39 immunochromatography and freeze-dried direct agglutination tests in the diagnosis of imported visceral leishmaniasis.

    PubMed

    El-Moamly, Amal; El-Sweify, Mohamed; Hafeez, Mohamed

    2012-01-01

    Visceral leishmaniasis (VL) is one of the neglected tropical diseases that require a global policy for integrated control programs. The disease is fatal if untreated, affects ∼500,000 persons/year, and is most prevalent in poor countries. Treatment is expensive and carries a risk of toxicity. Therefore, sensitive and specific diagnosis of VL is crucial to avoid under- or overdiagnosis. Selecting an appropriate serological diagnostic test is an issue of controversy and depends on geographic location. The study aimed to evaluate the performance of two serological techniques: recombinant antigen K39 (rK39)-immunochromatographic (IC) lateral flow assay (InBios, USA) that uses a recombinant Leishmania antigen K39 and the specific IgG detection by direct agglutination test (DAT, for the diagnosis of imported VL in non-endemic region (Saudi Arabia). The diagnostic accuracy of the two assays was assessed using bone marrow aspiration, direct microscopic examination, and culture on NNN agar as the "gold standard". The bone marrow specimens from Indian, Sudanese, and Bengali patients (n = 98) with suspected VL features were cultured. Thirty-five specimens were positive (36%). The sensitivity and specificity of rK39-IC test were 89% (95% CI 78-99) and 92% (95% CI 85-99), respectively. DAT (with cutoff ≥1:1,600) showed comparable results (sensitivity 94%; 95% CI 87-101 and specificity 95%; 95% CI 90-100). To conclude, the performance of rK39-IC test and DAT is comparable. Both tests are moderately sensitive and specific and could be used to facilitate the global drive to eliminate this disease. The rK39-IC test is a rapid, easy-to-perform test and can be used as a point-of-care diagnostic method.

  11. 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

    PubMed Central

    Munhoz, Danielle D.; Cardoso, Lucas T. A.; Luz, Daniela E.; Andrade, Fernanda B.; Horton, Denise S. P. Q.; Elias, Waldir P.; Piazza, Roxane M. F.

    2014-01-01

    Background 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. Methodology 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. Principal findings 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. Conclusion 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. PMID:25254981

  12. 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.

    PubMed

    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 <50 c.f.u. per swab, the sensitivity, specificity, positive and negative predictive values of the DLA test were 100, 55.5, 63.6 and 100 %, respectively. In conclusion, a chromogenic agar, such as SBS, and a DLA test can be used for rapid detection of GBS in pregnant 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. PMID:25082944

  13. A comparative study of Toxoplasma gondii seroprevalence in mink using a modified agglutination test, a Western blot, and enzyme-linked immunosorbent assays.

    PubMed

    Gu, Yi; Wang, Zedong; Cai, Yufeng; Li, Xiaoxing; Wei, Feng; Shang, Limin; Li, Jiping; Liu, Quan

    2015-09-01

    Toxoplasma gondii can infect almost all warm-blooded animals, and many serological methods have been developed to detect T. gondii infection in a variety of animal species. In the present study, the seroprevalence of T. gondii infection in farmed mink in northeast China was determined using the modified agglutination test (MAT), a Western blot (WB), and 3 enzyme-linked immunosorbent assays (ELISAs) with protein A/G conjugate, using either of 2 recombinant dense granule antigens, GRA1 and GRA7, or Toxoplasma soluble antigens (TSA). There was no significant difference between the detection results of the GRA1-, GRA7-, and TSA-ELISAs and WB (McNemar chi-square, P > 0.05), but a significant difference was observed between MAT and WB (P < 0.05). A near perfect agreement (97.0%) was found between the GRA7-ELISA and WB (κ = 0.83), and a substantial agreement (92.4-93.1%) was observed in the TSA- and GRA1-ELISAs (κ = 0.68-0.73). The GRA7-ELISA showed the highest sensitivity and specificity, and the lowest false-positive and negative rates, while the MAT gave both a low sensitivity and frequent false positives in comparison to the WB. Receiver operating characteristic analysis revealed the largest area under curve of 0.85 (95% confidence interval: 0.74-0.96), and the highest relative sensitivity (72.7%) and specificity (99.0%) for a cutoff value of 0.19 in the GRA7-ELISA. These results indicate that the GRA7-ELISA is suitable for detection of T. gondii infection in mink and that MAT should be used with caution.

  14. Evaluation of two rK39 dipstick tests, direct agglutination test, and indirect fluorescent antibody test for diagnosis of visceral leishmaniasis in a new epidemic site in highland Ethiopia.

    PubMed

    Cañavate, Carmen; Herrero, Merce; Nieto, Javier; Cruz, Israel; Chicharro, Carmen; Aparicio, Pilar; Mulugeta, Abate; Argaw, Daniel; Blackstock, Anna J; Alvar, Jorge; Bern, Caryn

    2011-01-01

    We assessed the performance characteristics of two rK39 immunochromatographic tests, a direct agglutination test (DAT), and an indirect immunofluorescent antibody test (IFAT) in the site of a new epidemic of visceral leishmaniasis (VL) in northwestern Ethiopia. The study population was composed of 179 patients with suspected VL and 67 controls. The sensitivities of Kalazar Detect(®), DiaMed-IT Leish(®), DAT, and IFAT in 35 polymerase chain reaction-confirmed VL cases were 94.3%, 91.4%, 91.4%, and 100%, respectively, and the specificities were 98.5%, 94%, 98.5%, and 98.5%, respectively. In a Bayesian latent class analysis of all 246 specimens, the estimated sensitivities were 90.5%, 89%, 88.8%, and 96% for Kalazar Detect(®), DiaMed-IT Leish(®), DAT, and IFAT, respectively; DAT showed the highest estimated specificity (97.4%). Both rK39 immunochromatographic tests perform as well as DAT, and are suitable for VL diagnosis in first-level health centers in this area of Ethiopia.

  15. Evaluation of Two rK39 Dipstick Tests, Direct Agglutination Test, and Indirect Fluorescent Antibody Test for Diagnosis of Visceral Leishmaniasis in a New Epidemic Site in Highland Ethiopia

    PubMed Central

    Cañavate, Carmen; Herrero, Merce; Nieto, Javier; Cruz, Israel; Chicharro, Carmen; Aparicio, Pilar; Mulugeta, Abate; Argaw, Daniel; Blackstock, Anna J.; Alvar, Jorge; Bern, Caryn

    2011-01-01

    We assessed the performance characteristics of two rK39 immunochromatographic tests, a direct agglutination test (DAT), and an indirect immunofluorescent antibody test (IFAT) in the site of a new epidemic of visceral leishmaniasis (VL) in northwestern Ethiopia. The study population was composed of 179 patients with suspected VL and 67 controls. The sensitivities of Kalazar Detect®, DiaMed-IT Leish®, DAT, and IFAT in 35 polymerase chain reaction–confirmed VL cases were 94.3%, 91.4%, 91.4%, and 100%, respectively, and the specificities were 98.5%, 94%, 98.5%, and 98.5%, respectively. In a Bayesian latent class analysis of all 246 specimens, the estimated sensitivities were 90.5%, 89%, 88.8%, and 96% for Kalazar Detect®, DiaMed-IT Leish®, DAT, and IFAT, respectively; DAT showed the highest estimated specificity (97.4%). Both rK39 immunochromatographic tests perform as well as DAT, and are suitable for VL diagnosis in first-level health centers in this area of Ethiopia. PMID:21212210

  16. Diagnosis of myocardial infarction based on lectin-induced erythrocyte agglutination: a feasibility study

    NASA Astrophysics Data System (ADS)

    Bocsi, József; Nieschke, Kathleen; Mittag, Anja; Reichert, Thomas; Laffers, Wiebke; Marecka, Monika; Pierzchalski, Arkadiusz; Piltz, Joachim; Esche, Hans-Jürgen; Wolf, Günther; Dähnert, Ingo; Baumgartner, Adolf; Tarnok, Attila

    2014-03-01

    Myocardial infarction (MI) is an acute life-threatening disease with a high incidence worldwide. Aim of this study was to test lectin-carbohydrate binding-induced red blood cell (RBC) agglutination as an innovative tool for fast, precise and cost effective diagnosis of MI. Five lectins (Ricinus communis agglutinin (RCA), Phaseolus vulgaris erythroagglutinin (PHA), Datura stramonium agglutinin (DSA), Artocarpus agglutinin (ArA), Triticum agglutinin (TA)) were tested for ability to differentiate between agglutination characteristics in patients with MI (n = 101) or angina pectoris without MI (AP) (n = 34) and healthy volunteers (HV) as control (n =68) . RBC agglutination was analyzed by light absorbance of a stirred RBC suspension in the green to red light spectrum in an agglutimeter (amtec, Leipzig, Germany) for 15 min after lectin addition. Mean cell count in aggregates was estimated from light absorbance by a mathematical model. Each lectin induced RBC agglutination. RCA led to the strongest RBC agglutination (~500 RBCs/aggregate), while the others induced substantially slower agglutination and lead to smaller aggregate sizes (5-150 RBCs/aggregate). For all analyzed lectins the lectin-induced RBC agglutination of MI or AP patients was generally higher than for HV. However, only PHA induced agglutination that clearly distinguished MI from HV. Variance analysis showed that aggregate size after 15 min. agglutination induced by PHA was significantly higher in the MI group (143 RBCs/ aggregate) than in the HV (29 RBC-s/aggregate, p = 0.000). We hypothesize that pathological changes during MI induce modification of the carbohydrate composition on the RBC membrane and thus modify RBC agglutination. Occurrence of carbohydrate-lectin binding sites on RBC membranes provides evidence about MI. Due to significant difference in the rate of agglutination between MI > HV the differentiation between these groups is possible based on PHA-induced RBC-agglutination. This novel assay

  17. Mannanoligosaccharide agglutination by Salmonella enterica strains isolated from carrier pigs

    PubMed Central

    Borowsky, Luciane; Corção, Gertrudes; Cardoso, Marisa

    2009-01-01

    Type-1 fimbriae are associated with most Salmonella enterica serovars and are an essential factor for host colonization. Mannanoligosaccharides (MOS), a prebiotic that is agglutinated by type-1 fimbriae, are proposed for the control of enterobacteria colonization and may be an alternative to Salmonella control in pigs. The aim of this study was to evaluate the capability of porcine Salmonella strains to adhere to MOS in vitro. A total of 108 strains of Salmonella sp. isolated from carrier pigs were evaluated for the amplification of fimA and fimH genes, agglutination of MOS and hemagglutination. In all tested strains, amplicons of expected size were detected for both fimA and fimH gene. In the hemagglutination assays, 31 (28.7%) strains presented mannose–sensitive agglutination of erythrocytes, indicating that the strains were expressing type-1 fimbriae. Considering only strains expressing the type-1 fimbriae, 23 (74.2%) presented a strong agglutination of MOS, 3 (9.6%) a weak reaction and 5 (16.2%) none. The results indicate that Salmonella enterica strains expressing type-1 fimbriae can agglutinate effectively in vitro to MOS. PMID:24031388

  18. Manufacturing High-Fidelity Lunar Agglutinate Simulants

    NASA Technical Reports Server (NTRS)

    Gutafson, R. J.; Edmunson, J. E.; Rickman, D. L.

    2010-01-01

    The lunar regolith is very different from many naturally occurring material on Earth because it forms in the unique, impact-dominated environment of the lunar surface. Lunar regolith is composed of five basic particle types: mineral fragments, pristine crystalline rock fragments, breccia fragments, glasses of various kinds, and agglutinates (glass-bonded aggregates). Agglutinates are abundant in the lunar regolith, especially in mature regoliths where they can be the dominant component.This presentation will discuss the technical feasibility of manufacturing-simulated agglutinate particles that match many of the unique properties of lunar agglutinates.

  19. GUST LAT Multiwavelength Planning

    NASA Technical Reports Server (NTRS)

    Thompson, D. J.

    2004-01-01

    Because gamma-ray astrophysics profits in powerful ways from multi-wavelength studies, the GLAST Large Area Telescope (LAT) Collaboration has started multiwavelength planning well before the scheduled 2007 launch. Many aspects of this program are of direct interest to observers using VERITAS and other atmospheric Cerenkov telescopes, whose capabilities complement those of GLAST. This talk with describe some of the current developmental concepts for GLAST LAT multiwavelength work, including release of data for transient sources, nearly-continuous monitoring of selected time-variable sources, pulsar timing, follow-on observations for source identification, coordinated blazar campaigns, and cross-calibration with other high-energy telescopes. Although few details are firm at this stage of preparation for GLAST, the LAT Collaboration looks forward to cooperation with a broad cross-section of the multiwave-length community. The GLAST Large Area Telescope is an international effort, with U.S. funding provided by the Department of Energy and NASA.

  20. Evaluation of the diagnostic accuracy of the modified agglutination test (MAT) and an indirect ELISA for the detection of serum antibodies against Toxoplasma gondii in sheep through Bayesian approaches.

    PubMed

    Mainar-Jaime, R C; Barberán, M

    2007-09-01

    The diagnostic accuracies of the modified agglutination test (MAT) and indirect ELISA test for the detection of serum antibodies against Toxoplasma gondii in sheep were evaluated through Bayesian approaches on two populations of sheep created from three different groups of animals (T. gondii-aborted ewes, colostrums-deprived newborn lambs, and ewe-lambs and adult ewes with unknown T. gondii infection status). Tests showed a high degree of agreement (kappa statistic = 0.93; 95% confidence interval = 0.87, 0.98) and a significant specificity (Sp) correlation (gamma(Sp) = 0.26; 95% credibility interval = 0.017, 0.61). When prior information was used for all unknown parameters the posterior medians for the sensitivity (Se) and Sp of the MAT and ELISA were, respectively, 92.6% (95% credibility interval = 85.2, 96.9), 95.5% (89.9, 98.7), 90.5% (83.4, 95.6), and 97.8% (94.2, 99.5). These estimates remained similar when uninformative priors were included. The Se estimates of the MAT and ELISA were higher than those obtained on pigs in other study using the same approach (Se = 80.6% and Sp = 89.5% for the MAT, and Se = 71.5% and Sp = 85.5% for the ELISA [Georgiadis, M.P., Wesley, O.J., Gardner, I.A., Singh, R., 2003. Correlation-adjusted estimation of sensitivity and specificity of two diagnostic tests. Appl. Stat. 52, 63-78]. This finding supported the believe that test performances may vary when applied on different animal species. Thus, if these tests are planned to be used on animal species other than sheep or pigs, their diagnostic accuracy should be re-assessed to prevent biased inferences from their results.

  1. Isolation of a Factor from Apple that Agglutinates Erwinia amylovora12

    PubMed Central

    Romeiro, R.; Karr, A.; Goodman, R.

    1981-01-01

    Extracts prepared from apple seeds contain a factor (AF) capable of agglutinating cells of Erwinia amylovora. In drop agglutination tests, AF is more active in agglutinating an avirulent, acapsular strain of E. amylovora than a virulent, capsular strain. AF precipitates in agar plates with a receptor derived from boiled cells of avirulent acapsular strain and, therefore, can be located during fractionation by rocket electrophoresis. AF was heat-stable and had a pH optimum for agglutination near ≅3.6 pH. The agglutination activity was not affected by the presence of Mg2+, Ca2+, or EDTA. AF was separated into two fractions (AF I and AF II) by elution from a Bio-Gel P-100 column. The precipitin and agglutination activities associated with AF II were found to be present in a positively charged molecule which was sensitive to treatment with protease and trypsin and, hence, presumably resides in a protein. The approximate molecular weight of AF II was determined to be 12,600 daltons. Besides precipitating the receptor derived from cells of avirulent acapsular strain, AF II was capable of precipitating extracellular polysaccharide from cultures of virulent capsular strain, sodium polygalacturonate, and carboxymethylcellulose. These three polymers also inhibited the agglutination activity associated with AF II. AF II could be replaced by poly-l-lysines in both the precipitin and agglutination assays. In addition, in antigen absorption experiments, poly-l-lysines were found to remove the receptors for AF II from the boiled extracts of avirulent acapsular strain. Based on these observations, it is proposed that the activity of AF II resides in a highly positively charged protein which causes agglutination of bacterial cells by interacting on a charge-charge basis with negatively charged components on the surface of the bacterial cells. PMID:16661997

  2. Sharper Fermi LAT Images

    NASA Astrophysics Data System (ADS)

    Portillo, Stephen; Finkbeiner, Douglas P.

    2015-01-01

    The Large Area Telescope on the Fermi Gamma-ray Space Telescope has a point spread function with large tails, consisting of events affected by tracker ineffiencies, inactive volumes, and hard scattering; these tails can make source confusion a limiting factor. The parameter CTBCORE, available in the publicly available Extended Fermi LAT data, estimates the quality of each event's direction reconstruction; by implementing a cut in this parameter, the tails of the point spread function can be suppressed at the cost of losing effective area. We implement cuts on CTBCORE and present updated instrument response functions derived from the Fermi LAT data itself, along with all-sky maps generated with these cuts. Having shown the effectiveness of these cuts, especially at low energies, we encourage their use in analyses where angular resolution is more important than Poisson noise.

  3. Light-scattering analysis of ultrasonic wave's influence on the RBC agglutination in vitro

    NASA Astrophysics Data System (ADS)

    Doubrovski, Valeri A.; Dvoretski, Costanten N.

    1999-04-01

    Elastic light scattering is one of the most often used optical methods to analyze the cells agglutination reaction - the base of a great number of medical diagnostic test and biomedical investigations. The increase of the resolution of methods and apparatus towards the induced cells aggregation - the foundation of the reaction of agglutination, is quite an actual problem. The solution of this problem increases the reliability of the diagnostic test and gives an opportunity to achieve the diagnostic information in the cases when the traditional approaches do not lead to the diagnostic results. The attempt to increase the resolution of the immune reaction analyzer by means of ultrasonic waves action on the reagent mixture in vitro is taken in this paper. The RBC agglutination reaction which is usually used for the blood group type examination is chosen as an example of an object of the investigation. Different laser optical trains of the devices based on the turbidimetric and nephelometric methods and their combination are analyzed here. The influence of the ultrasonic wave time interval action and of the features of the sample preparation procedure on the resolution towards the agglutination process was investigated in this work. It is shown that the ultrasonic wave action on the reagent mixture leads to a large gain in the resolution of the device towards the RBC agglutination process. The experiments showed that the resolution of the device was enough to register the agglutination process even for the erythrocytes with weak agglutination ability when the reaction was invisible without ultrasonic action. It occurred that the diagnostic test time was more than by an order shortened due to the ultrasonic wave action. The optimal ultrasonic time interval action, the sample preparation technology and experimental technique were defined. The principle of the ultrasonic wave action on the cells agglutination process suggested here can be spread out on the immune

  4. Process to create simulated lunar agglutinate particles

    NASA Technical Reports Server (NTRS)

    Gustafson, Robert J. (Inventor); Gustafson, Marty A. (Inventor); White, Brant C. (Inventor)

    2011-01-01

    A method of creating simulated agglutinate particles by applying a heat source sufficient to partially melt a raw material is provided. The raw material is preferably any lunar soil simulant, crushed mineral, mixture of crushed minerals, or similar material, and the heat source creates localized heating of the raw material.

  5. Fermi's Large Area Telescope (LAT)

    NASA Video Gallery

    Fermi’s Large Area Telescope (LAT) is the spacecraft’s main scientificinstrument. This animation shows a gamma ray (purple) entering the LAT,where it is converted into an electron (red) and a...

  6. Screening of bacterial isolates for mannose-specific lectin activity by agglutination of yeasts.

    PubMed Central

    Mirelman, D; Altmann, G; Eshdat, Y

    1980-01-01

    A total of 393 clinical bacterial isolates were tested for their ability to agglutinate yeast cells of either Saccharomyces cerevisiae or Candida albicans. A positive agglutination of yeasts that could be prevented by methyl alpha-D-mannoside was taken as an indication for the possible presence of a mannose-specific lectin (carbohydrate-binding protein) on the surface of the tested bacteria. Agglutination tests on glass slides showed that 38% of all the isolates tested were positive in their capacity to agglutinate yeasts. Among the various strains tested, all isolates of Serratia marcescens, Proteus morganii, and Citrobacter diversus, as well as 94% of Klebsiella pneumoniae, were positive. On the other hand, only 46% of the Escherichia coli, 48% of the salmonellae, 44% of the Citrobacter freundii, and 71% of the Aeromonas hydrophila isolates were positive. A quantitative determination of the lectin activity done by observing the agglutination of yeasts in microtiter plates showed that S. marcescens isolates were the most avid binders to the yeast, whereas Klebsiella and Citrobacter isolates were the weakest. PMID:6989854

  7. Evaluation of the usefulness of six commercial agglutination assays for serologic diagnosis of toxoplasmosis.

    PubMed

    Villard, Odile; Cimon, Bernard; Franck, Jacqueline; Fricker-Hidalgo, Hélène; Godineau, Nadine; Houze, Sandrine; Paris, Luc; Pelloux, Hervé; Villena, Isabelle; Candolfi, Ermanno

    2012-07-01

    Six agglutination tests for detecting Toxoplasma gondii-specific antibodies (immunoglobulin G or M) in serum were performed and compared. In total, 599 sera were examined using direct and indirect agglutination assays. Sensitivity varied from 93.7% to 100% and specificity from 97.1% to 99.2%. In a selected population with interfering diseases, the percentage of false positives ranged from 4.3% to 10.9%. Although an overall agreement of 100% was found for chronic toxoplasmosis, sensitivity for the detection of confirmed acute toxoplasmosis ranged from 86.4% to 97.3%. Regarding the large variability in terms of the performance of the 6 assays, tests based on the hemagglutination principle were found to be better than the other agglutination tests for all the panels evaluated, meaning that they could be used as qualitative or semiquantitative low-cost screening assays.

  8. The production curve for agglutinates in planetary regoliths

    NASA Astrophysics Data System (ADS)

    McKay, D. S.; Basu, A.

    1983-11-01

    Models for the production of agglutinates are developed that can be applied to the lunar surface or to any planetary or asteroidal body lacking an atmosphere. Models are developed using rate equations for progressively more complex situations and range from Model 1, which is a simple linear increase of agglutinate content with time, to Model 4, which includes provision for recycling of existing agglutinates and replenishment and burial of exposed soil. Model 4 has some aspects of a steady state because, depending on the rate constants, agglutinate content may be limited to an intermediate value, even for long exposure times. In an extreme case, agglutinate content may be limited to a value near zero. These models predict that agglutinates should be low in abundance in areas of thin regolith, such as the Lunokhod-2 site on the moon, and on asteroids. The models may also help explain the apparent low agglutinate abundances of lunar regolith breccias and meteorite regolith breccias.

  9. LATS1 (LATS, large tumor suppressor, homolog 1 (Drosophila))

    PubMed Central

    Visser-Grieve, Stacy; van Rensburg, Helena J Janse; Yang, Xiaolong

    2015-01-01

    LATS1 tumor suppressor is a serine/threonine kinase of the AGC kinase family and a core component of the Hippo pathway in mammals. LATS1 regulates various biological processes such as cell cycle progression, genetic stability, cell motility and adhesion, apoptosis, stem cell renewal and differentiation (Visser and Yang, 2010; Mo et al., 2014). LATS1 performs these functions by phosphorylating various substrates such as transcriptional co-activators YAP and TAZ (Zhao et al., 2007; Hao et al., 2008). LATS1 is also required for tissue homeostasis in both flies and mice (Visser et al., 2010). In addition to its roles in a broad spectrum of normal biological processes, loss of LATS1 has been shown to be important for the development of cancer and resistance to chemotherapeutic drugs (Visser et al., 2010). Therefore, understanding the molecular mechanisms underlying loss-of-LATS1-induced tumorigenesis and drug resistance will shed light on the design of new cancer treatment strategies in the future.

  10. Ultrasensitive Antibody Detection by Agglutination-PCR (ADAP)

    PubMed Central

    2016-01-01

    Antibodies are widely used biomarkers for the diagnosis of many diseases. Assays based on solid-phase immobilization of antigens comprise the majority of clinical platforms for antibody detection, but can be undermined by antigen denaturation and epitope masking. These technological hurdles are especially troublesome in detecting antibodies that bind nonlinear or conformational epitopes, such as anti-insulin antibodies in type 1 diabetes patients and anti-thyroglobulin antibodies associated with thyroid cancers. Radioimmunoassay remains the gold standard for these challenging antibody biomarkers, but the limited multiplexability and reliance on hazardous radioactive reagents have prevented their use outside specialized testing facilities. Here we present an ultrasensitive solution-phase method for detecting antibodies, termed antibody detection by agglutination-PCR (ADAP). Antibodies bind to and agglutinate synthetic antigen–DNA conjugates, enabling ligation of the DNA strands and subsequent quantification by qPCR. ADAP detects zepto- to attomoles of antibodies in 2 μL of sample with a dynamic range spanning 5–6 orders of magnitude. Using ADAP, we detected anti-thyroglobulin autoantibodies from human patient plasma with a 1000-fold increased sensitivity over an FDA-approved radioimmunoassay. Finally, we demonstrate the multiplexability of ADAP by simultaneously detecting multiple antibodies in one experiment. ADAP’s combination of simplicity, sensitivity, broad dynamic range, multiplexability, and use of standard PCR protocols creates new opportunities for the discovery and detection of antibody biomarkers. PMID:27064772

  11. Agglutinates and carbon accumulation in Apollo 17 lunar soils

    NASA Technical Reports Server (NTRS)

    Basu, A.; Meinschein, W. G.

    1976-01-01

    A critical review of maturity with respect to the abundance of implanted solar wind elements (SWE) in lunar soils indicates: (1) that the Rosiwal Principle has limited applicability in determining implantation of SWE in lunar soils, and (2) that despite a depletion of SWE in agglutinitic glass, agglutinates are enriched in SWE due to the presence of buried surfaces of numerous clasts within agglutinates. A statistical analysis of published data of several Apollo 17 soils indicates that the abundance of carbon and, by analogy, the abundance of other SWE are correlatable with the agglutinate content and the mean grain size of lunar soils. Microscopic examination of more than 5000 grains of agglutinates in polished thin sections reveals a wide range of variability in the mineralogy, grain size distribution, degree of recycling, etc., of the clast population in agglutinates. This indicates that the volume-correlated SWE content of agglutinates may vary and need not be constant.

  12. The chemistry of some individual lunar soil agglutinates

    NASA Technical Reports Server (NTRS)

    Gibbons, R. V.; Hoerz, F.; Schaal, R. B.

    1976-01-01

    The inquiry is centered on the composition of agglutinate glasses examined via microprobe techniques. The glass chemistry of the agglutinates is brought into relation with compositions of constituent detritus and bulk compositions of the parent soils, with recent reported results taken into cognizance. Electron microprobe analysis data were examined for possible chemical fractionation resulting from meteoritic impacts and formation of agglutinates in the lunar regolith; individual agglutinates from lunar soils 78222, 71061, and 60009 were probed. Differences between impact glasses and corresponding bulk soils were scrutinized. Agglutinate glass analyses tend to cluster near the bulk soil compositions. A slight enrichment in mafic elements in grand averages of the agglutinate clusters relative to the bulk soils was found. Evidence of total impact melts and minor partial shock melts is examined.

  13. Nitrogen isotopic signatures in agglutinates from breccia 79035

    NASA Technical Reports Server (NTRS)

    Kerridge, John F.; Kim, Yoosook; Kim, Jin S.; Marti, Kurt

    1993-01-01

    Agglutinates in the size range 125-175 microns from regolith breccia 79035 are substantially depleted in N compared with bulk 79035. Isotopically, agglutinate N closely resembles that found previously in ilmenite separates. The minimum (delta)N-15 value found during stepwise pyrolysis of agglutinates is significantly heavier than that observed for bulk 79035. The major host phase for trapped N in 79035, and the host phase of the lightest isotopic component(s), remain unidentified.

  14. Penicillamine prevents ram sperm agglutination in media that support capacitation.

    PubMed

    Leahy, T; Rickard, J P; Aitken, R J; de Graaf, S P

    2016-02-01

    Ram spermatozoa are difficult to capacitate in vitro. Here we describe a further complication, the unreported phenomenon of head-to-head agglutination of ram spermatozoa following dilution in the capacitation medium Tyrodes plus albumin, lactate and pyruvate (TALP). Sperm agglutination is immediate, specific and persistent and is not associated with a loss of motility. Agglutination impedes in vitro sperm handling and analysis. So the objectives of this study were to investigate the cause of sperm agglutination and potential agents which may reduce agglutination. The percentage of non-agglutinated, motile spermatozoa increased when bicarbonate was omitted from complete TALP suggesting that bicarbonate ions stimulate the agglutination process. d-penicillamine (PEN), a nucleophilic thiol, was highly effective at reducing agglutination. The inclusion of 250 μM PEN in TALP reduced the incidence of motile, agglutinated spermatozoa from 76.7 ± 2.7% to 2.8 ± 1.4%. It was then assessed if PEN (1 mM) could be included in existing ram sperm capacitation protocols (TALP +1 mM dibutyryl cAMP, caffeine and theophylline) to produce spermatozoa that were simultaneously capacitated and non-agglutinated. This protocol resulted in a sperm population which displayed high levels of tyrosine phosphorylated proteins and lipid disordered membranes (merocyanine-540) while remaining motile, viable, acrosome-intact and non-agglutinated. In summary, PEN (1 mM) can be included in ram sperm capacitation protocols to reduce sperm agglutination and allow for the in vitro assessment of ram sperm capacitation.

  15. The Classroom-Friendly ABO Blood Types Kit: Blood Agglutination Simulation

    ERIC Educational Resources Information Center

    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…

  16. Systems, devices, and methods for agglutination assays using sedimentation

    DOEpatents

    Schaff, Ulrich Y.; Sommer, Gregory J.; Singh, Anup K.

    2016-01-26

    Embodiments of the present invention include methods for conducting agglutination assays using sedimentation. Aggregates may be exposed to sedimentation forces and travel through a density medium to a detection area. Microfluidic devices, such as microfluidic disks, are described for conducting the agglutination assays, as are systems for conducting the assays.

  17. MEMS reagent and sample handling procedure: Feasibility of viral antibody detection by passive immune agglutination

    NASA Technical Reports Server (NTRS)

    Bailey, G. D.; Tenoso, H. J.

    1975-01-01

    An attempt was made to develop a test requiring no preadsorption steps for the assessment of antibodies to rubella and mumps viruses using the passive immune agglutination (PIA) method. Both rubella and mumps antigens and antibodies were prepared. Direct PIA tests, using rubella antigen-coated beads, and indirect PIA tests, using rubella antibody-coated beads, were investigated. Attempts, using either method, were unsuccessful. Serum interference along with nonspecific agglutination of beads by the rubella antigen resulted in no specific response under the test conditions investigated. A new, highly sensitive approach, the enzyme immunoassay (EIA) test system, is recommended to overcome the nonspecificity. This system is a logical outgrowth of some of the solid phase work done on MEMS and represents the next generation tests system that can be directly applied to early disease detection and monitoring.

  18. Rapid method for detection of Coxiella burnetii antibodies using high-density particle agglutination.

    PubMed Central

    Nguyen, S V; Otsuka, H; Zhang, G Q; To, H; Yamaguchi, T; Fukushi, H; Noma, A; Hirai, K

    1996-01-01

    A high-density particle agglutination test, using erythrocyte-sensitizing substance from phase II Coxiella burnetii adsorbed to high-density composite particles, was developed for rapid serodiagnosis of Q fever. The test was compared with the microimmunofluorescence test for sensitivity and specificity by using 3,036 human serum samples collected in Gifu Prefecture, Japan. An excellent agreement was found between the two tests for the acute-phase group and paired serum samples, but some discordant results were observed in the single-sample group. The sensitivity and specificity of the high-density particle agglutination test were both 100% in the former group and 81.6 and 99.9%, respectively, in the latter group. The test is a very promising tool for routine serodiagnosis of Q fever because of its simplicity, sensitivity, and specificity. PMID:8940428

  19. LAT Perspectives in Detection of High Energy Cosmic Ray Electrons

    NASA Technical Reports Server (NTRS)

    Moiseev, Alexander; Ormes, J. F.; Funk, Stefan

    2007-01-01

    The GLAST Large Area Telescope (LAT) science objectives and capabilities in the detection of high energy electrons in the energy range from 20 GeV to approx. 1 TeV are presented. LAT simulations are used to establish the event selections. It is found that maintaining the efficiency of electron detection at the level of 30% the residual hadron contamination does not exceed 2-3% of the electron flux. LAT should collect approx. ten million of electrons with the energy above 20 GeV for each year of observation. Precise spectral reconstruction with high statistics presents us with a unique opportunity to investigate several important problems such as studying galactic models of IC radiation, revealing the signatures of nearby sources such as high energy cutoff in the electron spectrum, testing the propagation model, and searching for KKDM particles decay through their contribution to the electron spectrum.

  20. The specificity of antisera against Bordetella pertussis examined by bacterial agglutination.

    PubMed

    Fredriksen, J H; Frøholm, L O; Kjennerud, U

    1987-12-01

    The specificity of conventional, adsorbed antisera against agglutinogens 1, 2, and 3 of Bordetella pertussis was examined by slide agglutination and by agglutination in microtitre wells. Unadsorbed hyperimmune sera showed higher agglutinating activity against autologous or homologous cells than against cells of heterologous serotype. Adsorption of sera with heterologous cells increased the serotype specificity considerably. In spite of extensive adsorption, these anti-agglutinogen sera were still found to cross-react with B. parapertussis and/or B. bronchiseptica strains. Adsorption experiments with B. pertussis hyperimmune sera against serotype 1-, 1.2-, and 1.3-organisms demonstrated that the cross-reacting surface antigens differed from the agglutinogens 1, 2, and 3. Thus, in making species-specific reagents for diagnostic use it may be of value to include adsorption with B. parapertussis and probably with B. bronchiseptica. Limited data indicated that there is no need to use B. avium for adsorption. The agglutination assays were also used to test three monoclonal antibodies stated to be specific for the agglutinogens 1, 2, and 3, respectively. Some anomalous behaviour for the anti-agglutinogen 1 reagent was found, whereas the anti-agglutinogen 2 and 3 reagents corresponded well with the present polyclonal factor sera. PMID:2894108

  1. Measuring glass abundances in lunar agglutinates. [Abstract only

    NASA Technical Reports Server (NTRS)

    Strait, M. M.; Basu, A.; Mckay, D. S.; Robinson, R.

    1994-01-01

    The purpose of this study is to develop a standard method for measuring modal abundances of glass in single agglutinates in the lunar regolith. Not only does agglutinitic glass increase in single agglutinates as clasts of older agglutinates get incorporated into newer agglutinates with increasing maturity, but it is in this glassy phase that nanophase superparamagnetic Fe metal originates as a result of reduction reactions during the agglutination process. We report the results of two sets of independent measurements using two different methods to determine the proportion of glass in single agglutinates. We have used polished grain mounts (PGM) of five hand-picked single agglutinates from Apollo 16 soil 61181. The ISI Scanning Electron Microscope (SEM) fitted with a high-resolution Backscattered Electron (BSE) detector was used to collect high-contrast BSE images of the agglutinates. Several images were collected to represent each single agglutinate. The contrast, brightness, and focus were adjusted to optimize each image collected. Histograms of the grayscale range for all images produced four 'peaks' corresponding to epoxy, glass, crystalline phases, and metal grains. We analyzed every grid point for 12 elements with a less than 1 micron electron beam using a CAMECA SX-50 electron probe microanalyzer (EPM). If any analysis was not within about 10% of the stoichiometry of a known lunar mineral, we considered that point to be nonmineralic. Our results show that there is a remarkable correspondence in the glass percentages obtained by the two methods. The EPM method may overestimate glass because secondary fluorescence from dusty clasts in agglutinitic glass can give the appearance of nonmineralic targets. The BSE method may underestimate glass because the diversity of compositions of agglutinitic glass may not be contained under one grayscale 'peak' during image analysis.

  2. Anatomy of individual agglutinates from a lunar highland soil

    NASA Astrophysics Data System (ADS)

    Basu, Abhijit; McKay, David S.; Morris, Richard V.; Wentworth, Susan J.

    1996-11-01

    We report results of our investigation of the relationship between values of Is/FeO (relative concentration of nanophase Fe0 divided by total FeO content), glass abundance, total Fe content, and degree of digestion of <20 μm clasts for 22 individual agglutinates (250-1000 μm) from the mature Apollo 16 soil 61181 (Is/FeO = 82 units in the <250 μm fraction). Agglutinates are important products of space weathering on the Moon, and they influence spectral observations at visible and near-IR wavelengths. Values of Is/FeO for individual agglutinates (250-1000 μm) within this single soil span a range from 3 to 262 units which is larger than the range observed for all Apollo 16 bulk soils (˜0 to 110 units). No correlation was observed between Is/FeO and glass abundance and FeO concentrations for either agglutinitic glass or whole agglutinate particles under investigation. Our results suggest that the variation in Is/FeO for agglutinates from a single soil may be in part a consequence of natural mixing processes on the Moon that produce highly-variable environments (with respect to surface exposure) for agglutinate formation and in part to variable kinetics of reactions in an agglutinate melt, which are influenced by a variety of factors including melt composition, temperature, impactor velocity, and quench rate. We cannot exclude but do not see evidence for other processes including addition of exotic agglutinates, micrometeoritic bombardment into compositionally-diverse microtargets, recycling of agglutinates, preferential melting of very fine soil particles, and production of nanophase Fe0 in amorphous rims of very fine irradiated lunar grains contributing to the observed variation of Is/FeO.

  3. Lectin-mediated agglutination of murine lymphoma cells. Cell surface deformability and reversibility of agglutination by saccharides.

    PubMed

    Nicolson, G L; Poste, G

    1979-07-01

    Agglutination of S49 mouse lymphoma cells by Ricinus communis I agglutinin can be reversed by the competing haptenic saccharide, lactose, soon after agglutination, but after further incubation in the absence of lectin the agglutination reaction could not be reversed by lactose and the cells remained as multicell aggregates. The irreversibility of S49 cell agglutination was time, temperature and lectin concentration dependent and its onset correlated with ultrastructurally observed deformation of adjacent cell surfaces and an increase in the proportion of adjacent cell surface areas in close apposition within multicell aggregates. Pretreatment of S49 cells with cytochalasin B or cytochalasin B plus vinblastine enhanced R. communis I agglutinin-mediated agglutination, while vinblastine alone and fluoride plus azide had essentially no effect. When drug-treated cells were agglutinated and then incubated in lectin-free drug-containing media for various times prior to lactose addition, the drug effects were more pronounced. Cytochalasin B alone or with vinblastine inhibited lactose reversal of S49 cell agglutination compared to the drug-free controls, while fluoride plus azide enhanced hapten reversibility. Electron microscopic analysis revealed that the onset of agglutination irreversibility correlated with cell surface deformation in the drug-treated cells. Cell aggregates that were more readily reversible by lactose (fluoride plus azide) were unchanged or less deformed, while S49 aggregates treated with cytochalasin B plus vinblastine were more deformed compared to controls without drugs. These experiments suggest a role for cell surface deformability as an important secondary effect during lectin-mediated cell agglutination of S49 lymphoma cells.

  4. Antibody blocks acquisition of bacterial colonization through agglutination.

    PubMed

    Roche, A M; Richard, A L; Rahkola, J T; Janoff, E N; Weiser, J N

    2015-01-01

    Invasive infection often begins with asymptomatic colonization of mucosal surfaces. A murine model of bacterial colonization with Streptococcus pneumoniae was used to study the mechanism for mucosal protection by immunoglobulin. In previously colonized immune mice, bacteria were rapidly sequestered within large aggregates in the nasal lumen. To further examine the role of bacterial agglutination in protection by specific antibodies, mice were passively immunized with immunoglobulin G (IgG) purified from antipneumococcal sera or pneumococcal type-specific monoclonal human IgA (hIgA1 or hIgA2). Systemically delivered IgG accessed the mucosal surface and blocked acquisition of colonization and transmission between littermates. Optimal protection by IgG was independent of Fc fragment and complement and, therefore, did not involve an opsonophagocytic mechanism. Enzymatic digestion or reduction of IgG before administration showed that protection required divalent binding that maintained its agglutinating effect. Divalent hIgA1 is cleaved by the pneumococcal member of a family of bacterial proteases that generate monovalent Fabα fragments. Thus, passive immunization with hIgA1 blocked colonization by an IgA1-protease-deficient mutant (agglutinated) but not the protease-producing wild-type parent (not agglutinated), whereas protease-resistant hIgA2 agglutinated and blocked colonization by both. Our findings highlight the importance of agglutinating antibodies in mucosal defense and reveal how successful pathogens evade this effect.

  5. Evaluation of a latex agglutination assay for the identification of Burkholderia pseudomallei and Burkholderia mallei.

    PubMed

    Duval, Brea D; Elrod, Mindy G; Gee, Jay E; Chantratita, Narisara; Tandhavanant, Sarunporn; Limmathurotsakul, Direk; Hoffmaster, Alex R

    2014-06-01

    Cases of melioidosis and glanders are rare in the United States, but the etiologic agents of each disease (Burkholderia pseudomallei and Burkholderia mallei, respectively) are classified as Tier 1 select agents because of concerns about their potential use as bioterrorism agents. A rapid, highly sensitive, and portable assay for clinical laboratories and field use is required. Our laboratory has further evaluated a latex agglutination assay for its ability to identify B. pseudomallei and B. mallei isolates. This assay uses a monoclonal antibody that specifically recognizes the capsular polysaccharide produced by B. pseudomallei and B. mallei, but is absent in closely related Burkholderia species. A total of 110 B. pseudomallei and B. mallei were tested, and 36 closely related Burkholderia species. The latex agglutination assay was positive for 109 of 110 (99.1% sensitivity) B. pseudomallei and B. mallei isolates tested.

  6. Agglutination of human erythrocytes by the interaction of Zn(2+)ion with histidine-651 on the extracellular domain of band 3.

    PubMed

    Kiyotake, Kento; Ochiai, Hideharu; Yamaguchi, Takeo

    2016-05-01

    Clustering of band 3, chloride/bicarbonate exchanger, has been reported in Zn(2+)-treated human erythrocytes. However, the agglutination of human erythrocytes is also induced by the interaction of Zn(2+)ion with histidine on band 3. Identification of histidine that interacts with Zn(2+)ion remains to be determined. The Zn(2+)-induced agglutination of human erythrocytes was unaffected by chymotrypsin cleavage of the small loop region containing His-547 in the extracellular domain of band 3. On the other hand, papain digestion of the large loop region containing His-651 in band 3 inhibited such Zn(2+)-induced agglutination. Moreover, Zn(2+)-induced erythrocyte agglutination was inhibited by the peptide (ARGWVIHPLG) containing His-651, but not by the peptide such as ARGWVIRPLG, which His-651 was substituted by arginine. Among 10 kinds of animal erythrocytes tested, interestingly, no agglutination by Zn(2+)ions was observed in cow cells only that the forth amino acid in the upstream from His-669 on the large loop of cow band 3 is aspartate (Asp-665) instead of glycine. As expected, the agglutination of human erythrocytes by Zn(2+) ions was inhibited in the presence of aspartate. These data indicate that the interaction of Zn(2+) ion with His-651 residue of band 3 plays an important role in the Zn(2+)-induced agglutination of human erythrocytes.

  7. Search for Spatially Extended Fermi-LAT Sources Using Two Years of Data

    SciTech Connect

    Lande, Joshua; Ackermann, Markus; Allafort, Alice; Ballet, Jean; Bechtol, Keith; Burnett, Toby; Cohen-Tanugi, Johann; Drlica-Wagner, Alex; Funk, Stefan; Giordano, Francesco; Grondin, Marie-Helene; Kerr, Matthew; Lemoine-Goumard, Marianne

    2012-07-13

    Spatial extension is an important characteristic for correctly associating {gamma}-ray-emitting sources with their counterparts at other wavelengths and for obtaining an unbiased model of their spectra. We present a new method for quantifying the spatial extension of sources detected by the Large Area Telescope (LAT), the primary science instrument on the Fermi Gamma-ray Space Telescope (Fermi). We perform a series of Monte Carlo simulations to validate this tool and calculate the LAT threshold for detecting the spatial extension of sources. We then test all sources in the second Fermi -LAT catalog (2FGL) for extension. We report the detection of seven new spatially extended sources.

  8. Detection of Salmonella enterica serovar Enteritidis (SE) Antibodies in Serum Using A Polystyrene Bead/SE Flagella Agglutination Assay

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Serologic screening of flocks can be an important method to detect Salmonella enteritidis (SE) infections but can be labor intensive or lack specificity. Our goal was to develop a rapid agglutination assay using SE flagella adsorbed to polystyrene beads as a simple, relatively specific test to dete...

  9. Evolution of carbon isotopes, agglutinates, and the lunar regolith

    NASA Technical Reports Server (NTRS)

    Desmarais, D. J.; Basu, A.; Hayes, J. M.; Meinschein, W. G.

    1975-01-01

    Apollo 17 light-mantle soils and Apollo 15 Apennine Front soils are compared with respect to isotopic enrichment of C-13 and the maturity of the site. Analyses of soil-size fractions indicate that while the carbon concentration on particle surfaces remains relatively constant with increasing soil maturity, total surface-correlated carbon increases due to increasing total soil surface area. The role of agglutinates in the incorporation of surface-correlated carbon into aggregate grains is examined; agglutinates contain a major percentage of the carbon found in mature soil, and the volume-correlated carbon component in agglutinates apparently continues to increase after the surface-correlated carbon concentrations have reached a constant value. Constraints that may limit the carbon concentration in lunar soils to a value not greater than 300 micrograms/g are considered.

  10. Purification of Oncornaviruses by Agglutination with Concanavalin A

    PubMed Central

    Stewart, Margaret L.; Summers, Donald F.; Soeiro, Ruy; Fields, Bernard N.; Maizel, Jacob V.

    1973-01-01

    Concanavalin A (Con A) has been used to rapidly and selectively agglutinate murine and avian oncornavirions from culture medium or plasma. The agglutinated virus was concentrated rapidly and gently by low-speed centrifugation and solubilization with α-methyl mannoside. Infectious virus was purified 2.3 times with respect to nucleic-acid content, and more than 60% of its infectivity was recovered. Infectious particles of densities 1.18 and 1.16 g/cm3 were found in mouse cells infected with Friend virus. Con A reacted only with particles of density 1.16 g/cm3, indicating heterogeneity with respect to carbohydrate content or structure as well as buoyant density. Electron microscopy of virus agglutinated with Con A showed a zone of Con A-glycoprotein complexes averaging 12-15 nm in thickness. Images PMID:4514301

  11. Studying red blood cell agglutination by measuring membrane viscosity with optical tweezers

    NASA Astrophysics Data System (ADS)

    Fernandes, Heloise P.; Fontes, Adriana; de Thomaz, André A.; Barbosa, Luiz C.; Barjas-Castro, Maria L.; Cesar, Carlos L.

    2007-09-01

    The red blood cell (RBC) viscoelastic membrane contains proteins and glycoproteins embedded in a fluid lipid bilayer that are responsible for cell agglutination. Manipulating RBCs rouleaux with a double optical tweezers, we observed that the cells slide easily one over the others but are strongly connected by their edges. An explanation for this behavior could be the fact that when the cells slide one over the others, proteins are dragged through the membrane. It confers to the movement a viscous characteristic that is dependent of the velocity between the RBCs and justifies why is so easy to slide them apart. Therefore, in a first step of this work, by measuring the force as a function of the relative velocity between two cells, we confirmed this assumption and used this viscous characteristic of the RBC rouleaux to determine the apparent membrane viscosity of the cell. As this behavior is related to the proteins interactions, we can use the apparent membrane viscosity to obtain a better understanding about cell agglutination. Methods related to cell agglutination induced by antigen-antibody interactions are the basis of most of tests used in transfusion centers. Then, in a second step of this work, we measured the apparent membrane viscosity using antibodies. We observed that this methodology is sensitive to different kinds of bindings between RBCs. Better comprehension of the forces and bindings between RBCs could improve the sensibility and specificity of the hemagglutination reactions and also guides the development of new potentiator substances.

  12. Prueba de Aptitud para el Aprendizaje de Lenguas Extranjeras (PAPALE) Language Aptitude Test (LAT) (First and Second Versions). English for Special Purposes. Emergency Care Attendant.

    ERIC Educational Resources Information Center

    Muro, Gertrude

    This book contains two versions of the Language Aptitude Test. It is part of a package of materials developed for use in an English for Special Purposes project, which offers classes in reading, grammar, and emergency care attendant training for limited English proficient students. Introductory material describes the parts of two versions and…

  13. Evolution of Shock Melt Compositions in Lunar Agglutinates

    NASA Technical Reports Server (NTRS)

    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.

  14. Synthesis for Lunar Simulants: Glass, Agglutinate, Plagioclase, Breccia

    NASA Technical Reports Server (NTRS)

    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.

  15. Agglutinating serum for distinguishing Staphylococcus aureus of human biotype.

    PubMed

    Live, I

    1975-08-01

    Antiserum to Staphylococcus aureus strain 17 was treated with S. aureus strain 61218 until the antibodies against thermostable agglutinogen were removed. The absorbed serum agglutinated phage-typable as well as phageuntypable staphylococci of human biotype, whether recovered from people or from dogs. PMID:125241

  16. Automated Science Processing for GLAST LAT Data

    SciTech Connect

    Chiang, James

    2007-07-12

    Automated Science Processing (ASP) will be performed by the GLAST Large Area Telescope (LAT) Instrument Science Operations Center (ISOC) on data from the satellite as soon as the Level 1 data are available in the ground processing pipeline. ASP will consist of time-critical science analyses that will facilitate follow-up and multi-wavelength observations of transient sources. These analyses include refinement of gamma-ray burst (GRB) positions, timing, flux and spectral properties, off-line searches for untriggered GRBs and gamma-ray afterglows, longer time scale monitoring of a standard set of sources (AGNs, X-ray binaries), and searches for previously unknown flaring sources in the LAT band. We describe the design of ASP and its scientific products; and we show results of a prototype implementation, driven by the standard LAT data processing pipeline, as applied to simulated LAT and GBM data.

  17. Automated Science Processing for GLAST LAT Data

    SciTech Connect

    Chiang, James; Carson, Jennifer; Focke, Warren; /SLAC

    2007-10-15

    Automated Science Processing (ASP) will be performed by the GLAST Large Area Telescope (LAT) Instrument Science Operations Center (ISOC) on data from the satellite as soon as the Level 1 data are available in the ground processing pipeline. ASP will consist of time-critical science analyses that will facilitate follow-up and multi-wavelength observations of transient sources. These analyses include refinement of gamma-ray burst (GRB) positions, timing, flux and spectral properties, off-line searches for untriggered GRBs and gamma-ray afterglows, longer time scale monitoring of a standard set of sources (AGNs, X-ray binaries), and searches for previously unknown flaring sources in the LAT band. We describe the design of ASP and its scientific products; and we show results of a prototype implementation, driven by the standard LAT data processing pipeline, as applied to simulated LAT and GBM data.

  18. Pneumococcal antigen detection in cerebrospinal fluid: a comparative study on counter immunoelectrophoresis, latex agglutination and coagglutination.

    PubMed

    Rai, G P; Zachariah, K; Sharma, R; Phadke, S; Belapurkar, K M

    2003-07-01

    The sensitivity, specificity, accuracy and predictive values of counter immunoelectrophoresis (CIE), latex agglutination (LA) and coagglutination (CoAg) tests were compared for detection of pneumococcal antigen in cerebrospinal fluid (CSF) of patients suspected of meningitis. A total of 95 CSF samples comprising 15 culture proven, 47 clinically suspected but culture negative cases of meningitis and 33 controls were screened by above tests. Among three tests, LA was found to have high sensitivity and moderately high negative predictive value than CIE and CoAg tests. However, CIE had slightly better specificity than LA and CoAg tests. Accuracywise CIE and LA tests were comparable than CoAg test. CIE and LA tests had high positive predictive value than CoAg test.

  19. Agglutinates as recorders of regolith evolution - Application to the Apollo 17 drill core

    SciTech Connect

    Laul, J.C.; Smith, M.R.

    1984-11-15

    Chemical data are reported for agglutinates from 26 depth intervals of the Apollo 17 deep drill core, and the compositions of the agglutinates are compared with those of the soils in which they occur. The agglutinate sequence suggests a scenario in which several closely-spaced depositional events were involved in the formation of the drill core, rather than a continuous accumulation process.

  20. Agglutinates as recorders of regolith evolution - Application to the Apollo 17 drill core

    NASA Technical Reports Server (NTRS)

    Laul, J. C.; Smith, M. R.; Papike, J. J.; Simon, S. B.

    1984-01-01

    Chemical data are reported for agglutinates from 26 depth intervals of the Apollo 17 deep drill core, and the compositions of the agglutinates are compared with those of the soils in which they occur. The agglutinate sequence suggests a scenario in which several closely-spaced depositional events were involved in the formation of the drill core, rather than a continuous accumulation process.

  1. Agglutinates as recorders of regolith evolution - Application to the Apollo 17 drill core

    NASA Astrophysics Data System (ADS)

    Laul, J. C.; Smith, M. R.; Papike, J. J.; Simon, S. B.

    1984-11-01

    Chemical data are reported for agglutinates from 26 depth intervals of the Apollo 17 deep drill core, and the compositions of the agglutinates are compared with those of the soils in which they occur. The agglutinate sequence suggests a scenario in which several closely-spaced depositional events were involved in the formation of the drill core, rather than a continuous accumulation process.

  2. Fast Magnetic Field-Enhanced Linear Colloidal Agglutination Immunoassay.

    PubMed

    Daynès, Aurélien; Temurok, Nevzat; Gineys, Jean-Philippe; Cauet, Gilles; Nerin, Philippe; Baudry, Jean; Bibette, Jérôme

    2015-08-01

    We present the principle of a fast magnetic field enhanced colloidal agglutination assay, which is based on the acceleration of the recognition rate between ligands and receptors induced by magnetic forces. By applying a homogeneous magnetic field of 20 mT for only 7 s, we detect CRP (C-reactive protein) in human serum at a concentration as low as 1 pM for a total cycle time of about 1 min in a prototype analyzer. Such a short measurement time does not impair the performances of the assay when compared to longer experiments. The concentration range dynamic is shown to cover 3 orders of magnitude. An analytical model of agglutination is also successfully fitting our data obtained with a short magnetic pulse.

  3. An inhibitor to erythrocyte agglutination in bovine albumin preparations.

    PubMed

    Gunson, H H; Phillips, P K

    1975-01-01

    Three out of 28 commercial preparations of bovine serum albumin have been encountered which have an inhibitory effect on the assay of anti-Rh-o(D) using the Technicon AutoAnalyser. The inhibitory property, which can also be demonstrated by standard manual serological techniques, appears to be directed towards the second stage of the agglutination reaction. An automated screening procedure for bovine serum albumin preparations and some properties of the inhibitor are described.

  4. Concanavalin A-induced agglutination of human leukemic and lymphoma cells.

    PubMed

    Maca, R D

    1976-04-01

    With a newly developed turbidometric method, concanavalin A was shown to agglutinate normal lymphocytes, lymphoma cells, and leukemic cells from chronic lymphocytic leukemia and from acute myelocytic and lymphocytic leukemia. However, there was a marked difference in the kinetics of this agglutination process. Leukemic blast cells and cells from a patient with convoluted lymphoma agglutinated poorly in this system. Conversely, the degree of agglutination for chronic lymphocytic leukemia cells was greater than that for the blast cells and also slightly greater than that for normal lymphocytes. Cultured cells from a Burkitt's lymphoma (Raji) and from a patient with poorly differentiated lymphoma agglutinated very rapidly with concanavalin A. Prior incubation of all cell types with neuraminidase markedly enhanced the agglutination process similar to that of trypsinization. Thus, these studies illustrate the usefulness of this method in quantitating the kinetics of agglutination of various human neoplastic cell types by concanavalin A. PMID:1063062

  5. Mononucleosis spot test

    MedlinePlus

    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 ...

  6. Fermi-LAT Observations of Galactic Transients

    NASA Technical Reports Server (NTRS)

    Hays, Elizabeth

    2011-01-01

    This slide presentation reviews the observations of Galactic transients by the Large Area Telescope (LAT) on the Fermi Gamma Ray Space Telescope. The LAT is producing spectacular results for the GeV transient sky, some of which are shown and reviewed. Some of the results in the GeV range that are discussed in this presentation are: (1) New blazars and unidentified transients (2) the jet of the Cygnus X-3 microquasar (3) gamma rays from V407 Cygni nova (4) Fast high-energy gamma-ray flares from the Crab Nebula

  7. LATS2 Positively Regulates Polycomb Repressive Complex 2.

    PubMed

    Torigata, Kosuke; Daisuke, Okuzaki; Mukai, Satomi; Hatanaka, Akira; Ohka, Fumiharu; Motooka, Daisuke; Nakamura, Shota; Ohkawa, Yasuyuki; Yabuta, Norikazu; Kondo, Yutaka; Nojima, Hiroshi

    2016-01-01

    LATS2, a pivotal Ser/Thr kinase of the Hippo pathway, plays important roles in many biological processes. LATS2 also function in Hippo-independent pathway, including mitosis, DNA damage response and epithelial to mesenchymal transition. However, the physiological relevance and molecular basis of these LATS2 functions remain obscure. To understand novel functions of LATS2, we constructed a LATS2 knockout HeLa-S3 cell line using TAL-effector nuclease (TALEN). Integrated omics profiling of this cell line revealed that LATS2 knockout caused genome-wide downregulation of Polycomb repressive complex 2 (PRC2) and H3K27me3. Cell-cycle analysis revealed that downregulation of PRC2 was not due to cell cycle aberrations caused by LATS2 knockout. Not LATS1, a homolog of LATS2, but LATS2 bound PRC2 on chromatin and phosphorylated it. LATS2 positively regulates histone methyltransferase activity of PRC2 and their expression at both the mRNA and protein levels. Our findings reveal a novel signal upstream of PRC2, and provide insight into the crucial role of LATS2 in coordinating the epigenome through regulation of PRC2. PMID:27434182

  8. LATS2 Positively Regulates Polycomb Repressive Complex 2

    PubMed Central

    Torigata, Kosuke; Daisuke, Okuzaki; Mukai, Satomi; Hatanaka, Akira; Ohka, Fumiharu; Motooka, Daisuke; Nakamura, Shota; Ohkawa, Yasuyuki; Yabuta, Norikazu; Kondo, Yutaka; Nojima, Hiroshi

    2016-01-01

    LATS2, a pivotal Ser/Thr kinase of the Hippo pathway, plays important roles in many biological processes. LATS2 also function in Hippo-independent pathway, including mitosis, DNA damage response and epithelial to mesenchymal transition. However, the physiological relevance and molecular basis of these LATS2 functions remain obscure. To understand novel functions of LATS2, we constructed a LATS2 knockout HeLa-S3 cell line using TAL-effector nuclease (TALEN). Integrated omics profiling of this cell line revealed that LATS2 knockout caused genome-wide downregulation of Polycomb repressive complex 2 (PRC2) and H3K27me3. Cell-cycle analysis revealed that downregulation of PRC2 was not due to cell cycle aberrations caused by LATS2 knockout. Not LATS1, a homolog of LATS2, but LATS2 bound PRC2 on chromatin and phosphorylated it. LATS2 positively regulates histone methyltransferase activity of PRC2 and their expression at both the mRNA and protein levels. Our findings reveal a novel signal upstream of PRC2, and provide insight into the crucial role of LATS2 in coordinating the epigenome through regulation of PRC2. PMID:27434182

  9. Measurement of RBC agglutination with microscopic cell image analysis in a microchannel chip.

    PubMed

    Cho, Chi Hyun; Kim, Ju Yeon; Nyeck, Agnes E; Lim, Chae Seung; Hur, Dae Sung; Chung, Chanil; Chang, Jun Keun; An, Seong Soo A; Shin, Sehyun

    2014-01-01

    Since Landsteiner's discovery of ABO blood groups, RBC agglutination has been one of the most important immunohematologic techniques for ABO and RhD blood groupings. The conventional RBC agglutination grading system for RhD blood typings relies on macroscopic reading, followed by the assignment of a grade ranging from (-) to (4+) to the degree of red blood cells clumping. However, with the new scoring method introduced in this report, microscopically captured cell images of agglutinated RBCs, placed in a microchannel chip, are used for analysis. Indeed, the cell images' pixel number first allows the differentiation of agglutinated and non-agglutinated red blood cells. Finally, the ratio of agglutinated RBCs per total RBC counts (CRAT) from 90 captured images is then calculated. During the trial, it was observed that the agglutinated group's CRAT was significantly higher (3.77-0.003) than that of the normal control (0). Based on these facts, it was established that the microchannel method was more suitable for the discrimination between agglutinated RBCs and non-agglutinated RhD negative, and thus more reliable for the grading of RBCs agglutination than the conventional method.

  10. Evaluation of Polysaccharide-Based Latex Agglutination Assays for the Rapid Detection of Antibodies to Burkholderia pseudomallei

    PubMed Central

    Suttisunhakul, Vichaya; Chantratita, Narisara; Wikraiphat, Chanthiwa; Wuthiekanun, Vanaporn; Douglas, Zakiya; Day, Nicholas P. J.; Limmathurotsakul, Direk; Brett, Paul J.; Burtnick, Mary N.

    2015-01-01

    Melioidosis is a severe disease caused by the Gram-negative bacterium Burkholderia pseudomallei. Diagnosis of melioidosis currently relies on the isolation of B. pseudomallei from clinical samples, which can take several days. An indirect hemagglutination assay (IHA) is widely used for serodiagnosis, but it has a short shelf life, is poorly standardized, and requires a viable bacteria culture performed in a biosafety level 3 (BSL-3) laboratory. To improve the diagnostic methods, we have developed two rapid latex agglutination tests based on purified B. pseudomallei O-polysaccharide (OPS) and capsular polysaccharide (CPS) antigens. The immunodiagnostic potential of these tests was evaluated using serum from culture-confirmed melioidosis patients (N = 143) and healthy donors from either endemic (N = 199) or non-endemic areas (N = 90). The sensitivity of the OPS-based latex agglutination assay (OPS-latex; 84.4%) was significantly higher than both the CPS-latex (69.5%) (P < 0.001) and IHA (69.5%) (P = 0.001). When evaluated with Thai donor serum, the OPS-latex had comparable specificity (56.9%) to the CPS-latex (63.8%) (P = 0.053), but was significantly lower than the IHA (67.6%) (P = 0.002). In contrast, all tests with U.S. donor serum were highly specific (≥ 97.8%). These results suggest that polysaccharide-based latex agglutination assays may be useful for serodiagnosis of melioidosis in non-endemic areas. PMID:26123956

  11. The GLAST Mission, LAT and GRBs

    SciTech Connect

    Omodei, Nicola; /INFN, Pisa

    2006-04-05

    The GLAST Large Area Telescope (LAT) is the next generation satellite experiment for high-energy gamma-ray astronomy. It is a pair conversion telescope built with a plastic anticoincidence shield, a segmented CsI electromagnetic calorimeter, and the largest silicon strip tracker ever built. It will cover the energy range from 30 MeV to 300 GeV, shedding light on many issues left open by its predecessor EGRET. One of the most exciting science topics is the detection and observation of gamma-ray bursts (GRBs). In this paper we present the work done so far by the GRB LAT science group in studying the performance of the LAT detector to observe GRBs.We report on the simulation framework developed by the group as well as on the science tools dedicated to GRBs data analysis. We present the LAT sensitivity to GRBs obtained with such simulations, and, finally, the general scheme of GRBs detection that will be adopted on orbit.

  12. Amyloidogenic amyloid-β-peptide variants induce microbial agglutination and exert antimicrobial activity.

    PubMed

    Spitzer, Philipp; Condic, Mateja; Herrmann, Martin; Oberstein, Timo Jan; Scharin-Mehlmann, Marina; Gilbert, Daniel F; Friedrich, Oliver; Grömer, Teja; Kornhuber, Johannes; Lang, Roland; Maler, Juan Manuel

    2016-01-01

    Amyloid-β (Aβ) peptides are the main components of the plaques found in the brains of patients with Alzheimer's disease. However, Aβ peptides are also detectable in secretory compartments and peripheral blood contains a complex mixture of more than 40 different modified and/or N- and C-terminally truncated Aβ peptides. Recently, anti-infective properties of Aβ peptides have been reported. Here, we investigated the interaction of Aβ peptides of different lengths with various bacterial strains and the yeast Candida albicans. The amyloidogenic peptides Aβ1-42, Aβ2-42, and Aβ3p-42 but not the non-amyloidogenic peptides Aβ1-40 and Aβ2-40 bound to microbial surfaces. As observed by immunocytochemistry, scanning electron microscopy and Gram staining, treatment of several bacterial strains and Candida albicans with Aβ peptide variants ending at position 42 (Aβx-42) caused the formation of large agglutinates. These aggregates were not detected after incubation with Aβx-40. Furthermore, Aβx-42 exerted an antimicrobial activity on all tested pathogens, killing up to 80% of microorganisms within 6 h. Aβ1-40 only had a moderate antimicrobial activity against C. albicans. Agglutination of Aβ1-42 was accelerated in the presence of microorganisms. These data demonstrate that the amyloidogenic Aβx-42 variants have antimicrobial activity and may therefore act as antimicrobial peptides in the immune system. PMID:27624303

  13. Amyloidogenic amyloid-β-peptide variants induce microbial agglutination and exert antimicrobial activity

    PubMed Central

    Spitzer, Philipp; Condic, Mateja; Herrmann, Martin; Oberstein, Timo Jan; Scharin-Mehlmann, Marina; Gilbert, Daniel F.; Friedrich, Oliver; Grömer, Teja; Kornhuber, Johannes; Lang, Roland; Maler, Juan Manuel

    2016-01-01

    Amyloid-β (Aβ) peptides are the main components of the plaques found in the brains of patients with Alzheimer’s disease. However, Aβ peptides are also detectable in secretory compartments and peripheral blood contains a complex mixture of more than 40 different modified and/or N- and C-terminally truncated Aβ peptides. Recently, anti-infective properties of Aβ peptides have been reported. Here, we investigated the interaction of Aβ peptides of different lengths with various bacterial strains and the yeast Candida albicans. The amyloidogenic peptides Aβ1-42, Aβ2-42, and Aβ3p-42 but not the non-amyloidogenic peptides Aβ1-40 and Aβ2-40 bound to microbial surfaces. As observed by immunocytochemistry, scanning electron microscopy and Gram staining, treatment of several bacterial strains and Candida albicans with Aβ peptide variants ending at position 42 (Aβx-42) caused the formation of large agglutinates. These aggregates were not detected after incubation with Aβx-40. Furthermore, Aβx-42 exerted an antimicrobial activity on all tested pathogens, killing up to 80% of microorganisms within 6 h. Aβ1-40 only had a moderate antimicrobial activity against C. albicans. Agglutination of Aβ1-42 was accelerated in the presence of microorganisms. These data demonstrate that the amyloidogenic Aβx-42 variants have antimicrobial activity and may therefore act as antimicrobial peptides in the immune system. PMID:27624303

  14. Comparison of sensitivities and specificities of latex agglutination and an enzyme-linked immunosorbent assay for detection of antibodies to the human immunodeficiency virus in African sera.

    PubMed

    Francis, H L; Kabeya, M; Kafuama, N; Riggins, C; Colebunders, R; Ryder, R; Curran, J; Izaley, L; Quinn, T C

    1988-11-01

    The sensitivities, specificities, and positive and negative predictive values of the Cambridge BioScience Corp. (Worcester, Mass.) human immunodeficiency virus latex agglutination assay were compared by using three different blood preparations. By using the manufacturer's standard test method with diluted sera, the sensitivity of latex agglutination was 100%, the specificity was 99.58%, and the positive and negative predictive values were 99.26 and 100%, respectively. Use of diluted whole blood or undiluted whole blood did not significantly affect the sensitivity (mean, 99.72%), specificity (mean, 99.47%), positive predictive value (mean, 99.07%), or negative predictive value (mean, 99.89%). The latex agglutination assay is a simple, rapid assay for the detection of human immunodeficiency virus that would be useful in Third World countries or other areas where enzyme-linked immunosorbent assays are not available or cannot be used.

  15. Prevalence of agglutinating antibodies to Toxoplasma gondii and Sarcocystis neurona in beavers (Castor canadensis) from Massachusetts

    USGS Publications Warehouse

    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.

  16. Formation of agglutinate-like particles in an experimental regolith

    NASA Technical Reports Server (NTRS)

    See, Thomas H.; Horz, Friedrich

    1988-01-01

    Agglutinate-like particles composed predominantly of glass were produced from a fragmental gabbro target that was repetitively impacted by Ni-alloy projectiles. The experimental glasses are much more heterogeneous in composition than their lunar counterparts, and they are dominated by incomplete mixing of melted component minerals and by plagioclase-rich compositions. Most of the particles are found to be highly enriched in feldspar and to be sustantially fractionated relative to the initial bulk target. It is suggested that fractionation trends within lunar agglutinitic glasses may be partly due to phase-specific melting.

  17. Agglutination of human O erythrocytes by influenza A(H1N1) viruses freshly isolated from patients.

    PubMed

    Murakami, T; Haruki, K; Seto, Y; Kimura, T; Minoshiro, S; Shibe, K

    1991-04-01

    The hemagglutinin titers of 10 influenza A (H1N1) viruses were examined using the erythrocytes of several species. Human O erythrocytes showed the highest agglutination titer to the viruses, whereas chicken erythrocytes showed a low titer. These findings were noted for at least 10 passages by serial dilutions of the viruses in Madin-Darby canine kidney (MDCK) cells. All influenza A(H1N1) viruses, plaque-cloned directly from throat-washing specimens of patients, also agglutinated human O but not chicken erythrocytes. The results of a hemadsorption test indicated that chicken erythrocytes possess less affinity to MDCK cells infected with the A/Osaka City/2/88(H1N1) stain than to those infected with the A/Yamagata/120/86(H1N1) strain which is used as an inactivated influenza vaccine in Japan. However, there were no significant differences between the A/Osaka City/2/88 and the A/Yamagata/120/86 strains in the hemagglutination inhibition test. Since human O erythrocytes have high agglutination activity to influenza A(H1N1) and also to A(H3N2) and B viruses in MDCK cells, these erythrocytes may be useful for the serological diagnosis of influenza. PMID:2066386

  18. Agglutination of human O erythrocytes by influenza A(H1N1) viruses freshly isolated from patients.

    PubMed

    Murakami, T; Haruki, K; Seto, Y; Kimura, T; Minoshiro, S; Shibe, K

    1991-04-01

    The hemagglutinin titers of 10 influenza A (H1N1) viruses were examined using the erythrocytes of several species. Human O erythrocytes showed the highest agglutination titer to the viruses, whereas chicken erythrocytes showed a low titer. These findings were noted for at least 10 passages by serial dilutions of the viruses in Madin-Darby canine kidney (MDCK) cells. All influenza A(H1N1) viruses, plaque-cloned directly from throat-washing specimens of patients, also agglutinated human O but not chicken erythrocytes. The results of a hemadsorption test indicated that chicken erythrocytes possess less affinity to MDCK cells infected with the A/Osaka City/2/88(H1N1) stain than to those infected with the A/Yamagata/120/86(H1N1) strain which is used as an inactivated influenza vaccine in Japan. However, there were no significant differences between the A/Osaka City/2/88 and the A/Yamagata/120/86 strains in the hemagglutination inhibition test. Since human O erythrocytes have high agglutination activity to influenza A(H1N1) and also to A(H3N2) and B viruses in MDCK cells, these erythrocytes may be useful for the serological diagnosis of influenza.

  19. GLAST LAT And Pulsars: What Do We Learn from Simulations?

    SciTech Connect

    Razzano, Massimiliano; Harding, Alice K.; /NASA, Goddard

    2007-10-24

    Gamma-ray pulsars are among the best targets for the Large Area Telescope (LAT) aboard the GLAST mission. The higher sensitivity, time and energy resolution of the LAT will provide data of fundamental importance to understand the physics of these fascinating objects. Powerful tools for studying the LAT capabilities for pulsar science are the simulation programs developed within the GLAST Collaboration. Thanks to these simulations it is possible to produce a detailed distribution of gamma-ray photons in energy and phase that can be folded through the LAT Instrument Response Functions (IRFs). Here we present some of the main interesting results from the simulations developed to study the discovery potential of the LAT. In particular we will focus on the capability of the LAT to discover new radio-loud gamma-ray pulsars, on the discrimination between Polar Cap and Outer Gap models, and on the LAT pulsar sensitivity.

  20. An evolutionarily conserved negative feedback mechanism in the Hippo pathway reflects functional difference between LATS1 and LATS2

    PubMed Central

    Park, Gun-Soo; Oh, Hyangyee; Kim, Minchul; Kim, Tackhoon; Johnson, Randy L.; Irvine, Kenneth D.; Lim, Dae-Sik

    2016-01-01

    The Hippo pathway represses YAP oncoprotein activity through phosphorylation by LATS kinases. Although variety of upstream components has been found to participate in the Hippo pathway, the existence and function of negative feedback has remained uncertain. We found that activated YAP, together with TEAD transcription factors, directly induces transcription of LATS2, but not LATS1, to form a negative feedback loop. We also observed increased mRNA levels of Hippo upstream components upon YAP activation. To reveal the physiological role of this negative feedback regulation, we deleted Lats2 or Lats1 in the liver-specific Sav1-knockout mouse model which develops a YAP-induced tumor. Additional deletion of Lats2 severely enhanced YAP-induced tumorigenic phenotypes in a liver specific Sav1 knock-out mouse model while additional deletion of Lats1 mildly affected the phenotype. Only Sav1 and Lats2 double knock-down cells formed larger colonies in soft agar assay, thereby recapitulating accelerated tumorigenesis seen in vivo. Importantly, this negative feedback is evolutionarily conserved, as Drosophila Yorkie (YAP ortholog) induces transcription of Warts (LATS2 ortholog) with Scalloped (TEAD ortholog). Collectively, we demonstrated the existence and function of an evolutionarily conserved negative feedback mechanism in the Hippo pathway, as well as the functional difference between LATS1 and LATS2 in regulation of YAP. PMID:27006470

  1. Decreased reactivation of a herpes simplex virus type 1 (HSV-1) latency associated transcript (LAT) mutant using the in vivo mouse UV-B model of induced reactivation

    PubMed Central

    BenMohamed, Lbachir; Osorio, Nelson; Srivastava, Ruchi; Khan, Arif A.; Simpson, Jennifer L.; Wechsler, Steven L.

    2015-01-01

    Blinding ocular herpetic disease in humans is due to herpes simplex virus type 1 (HSV-1) reactivations from latency, rather than to primary acute infection. The cellular and molecular mechanisms that control the HSV-1 latency-reactivation cycle remain to be fully elucidated. The aim of this study was to determine if reactivation of the HSV-1 latency associated transcript (LAT) deletion mutant (dLAT2903) was impaired in this model, as it is in the rabbit model of induced and spontaneous reactivation and in the explant TG induced reactivation model in mice. The eyes of mice latently infected with wild type HSV-1 strain McKrae (LAT(+) virus) or dLAT2903 (LAT(−) virus) were irradiated with UV-B and reactivation was determined. We found that compared to LAT(−) virus, LAT(+) virus reactivated at a higher rate as determined by shedding of virus in tears on days 3 to 7 after UV-B treatment. Thus, the UV-B induced reactivation model of HSV-1 appears to be a useful small animal model for studying the mechanisms involved in how LAT enhances the HSV-1 reactivation phenotype. The utility of the model for investigating the immune evasion mechanisms regulating the HSV-1 latency/reactivation cycle and for testing the protective efficacy of candidate therapeutic vaccines and drugs are discussed. PMID:26002839

  2. Studying red blood cell agglutination by measuring electrical and mechanical properties with a double optical tweezers

    NASA Astrophysics Data System (ADS)

    Fontes, Adriana; Fernandes, Heloise P.; de Thomaz, André A.; Barbosa, Luiz C.; Barjas-Castro, Maria L.; Cesar, Carlos L.

    2007-07-01

    The red blood cell (RBC) viscoelastic membrane contains proteins and glycolproteins embedded in, or attached, to a fluid lipid bilayer and are negatively charged, which creates a repulsive electric (zeta) potential between the cells and prevents their aggregation in the blood stream. The basis of the immunohematologic tests is the interaction between antigens and antibodies that causes hemagglutination. The identification of antibodies and antigens is of fundamental importance for the transfusional routine. This agglutination is induced by decreasing the zeta-potential through the introduction of artificial potential substances. This report proposes the use of the optical tweezers to measure the membrane viscosity, the cell adhesion, the zeta-potential and the size of the double layer of charges (CLC) formed around the cell in an electrolytic solution. The adhesion was quantified by slowly displacing two RBCs apart until the disagglutination. The CLC was measured using the force on the bead attached to a single RBC in response to an applied voltage. The zeta-potential was obtained by measuring the terminal velocity after releasing the RBC from the optical trap at the last applied voltage. For the membrane viscosity experiment, we trapped a bead attached to RBCs and measured the force to slide one RBC over the other as a function of the relative velocity. After we tested the methodology, we performed measurements using antibody and potential substances. We observed that this experiment can provide information about cell agglutination that helps to improve the tests usually performed in blood banks. We also believe that this methodology can be applied for measurements of zeta-potentials in other kind of samples.

  3. An experimental investigation of agglutinate melting mechanisms - Shocked mixtures of sodium and potassium feldspars

    NASA Technical Reports Server (NTRS)

    Simon, S. B.; Papike, J. J.; Horz, F.; See, T. H.

    1985-01-01

    The results of an experiment designed to test the validity of the model for agglutinate formation involving fusion of the finest fraction or F3 are reported. Impact glasses were formed from various mixes of orthoclase and albite powders, which were used as analogs for soils with chemically constrasting coarse and fine fractions. The results showed that the single most important factor displacing the composition of a small-scale impact melt from the bulk composition of the source regolith is the fractionated composition of the finest soil fraction. Volatile loss and the amount of melting, which in turn are determined by the degree of shock, are also important. As predicted by the model, the lower pressure melts are the most fractionated, and higher pressure is accompanied by increased melting causing glass compositions to approach the bulk. In general, the systematics predicted by the model are observed; the model appears to be valid.

  4. Overexpression of L-Type Amino Acid Transporter 1 (LAT1) and 2 (LAT2): Novel Markers of Neuroendocrine Tumors

    PubMed Central

    Barollo, Susi; Bertazza, Loris; Watutantrige-Fernando, Sara; Censi, Simona; Cavedon, Elisabetta; Galuppini, Francesca; Pennelli, Gianmaria; Fassina, Ambrogio; Citton, Marilisa; Rubin, Beatrice; Pezzani, Raffaele; Benna, Clara; Opocher, Giuseppe; Iacobone, Maurizio; Mian, Caterina

    2016-01-01

    Background 6-18F-fluoro-L-3,4-dihydroxyphenylalanine (18F-FDOPA) PET is a useful tool in the clinical management of pheochromocytoma (PHEO) and medullary thyroid carcinoma (MTC). 18F-FDOPA is a large neutral amino acid biochemically resembling endogenous L-DOPA and taken up by the L-type amino acid transporters (LAT1 and LAT2). This study was conducted to examine the expression of the LAT system in PHEO and MTC. Methods Real-time PCR and Western blot analyses were used to assess LAT1 and LAT2 gene and protein expression in 32 PHEO, 38 MTC, 16 normal adrenal medulla and 15 normal thyroid tissue samples. Immunohistochemistry method was applied to identify the proteins’ subcellular localization. Results LAT1 and LAT2 were overexpressed in both PHEO and MTC by comparison with normal tissues. LAT1 presented a stronger induction than LAT2, and their greater expression was more evident in PHEO (15.1- and 4.1-fold increases, respectively) than in MTC (9.9- and 4.1-fold increases, respectively). Furthermore we found a good correlation between LAT1/2 and GLUT1 expression levels. A positive correlation was also found between urinary noradrenaline and adrenaline levels and LAT1 gene expression in PHEO. The increased expression of LAT1 is also confirmed at the protein level, in both PHEO and MTC, with a strong cytoplasmic localization. Conclusions The present study is the first to provide experimental evidence of the overexpression in some NET cancers (such as PHEO or MTC) of L-type amino acid transporters, and the LAT1 isoform in particular, giving the molecular basis to explain the increase of the DOPA uptake seen in such tumor cells. PMID:27224648

  5. An early Cambrian agglutinated tubular lophophorate with brachiopod characters

    PubMed Central

    Zhang, Z.-F.; Li, G.-X.; Holmer, L. E.; Brock, G. A.; Balthasar, U.; Skovsted, C. B.; Fu, D.-J.; Zhang, X.-L.; Wang, H.-Z.; Butler, A.; Zhang, Z.-L.; Cao, C.-Q.; Han, J.; Liu, J.-N.; Shu, D.-G.

    2014-01-01

    The morphological disparity of lophotrochozoan phyla makes it difficult to predict the morphology of the last common ancestor. Only fossils of stem groups can help discover the morphological transitions that occurred along the roots of these phyla. Here, we describe a tubular fossil Yuganotheca elegans gen. et sp. nov. from the Cambrian (Stage 3) Chengjiang Lagerstätte (Yunnan, China) that exhibits an unusual combination of phoronid, brachiopod and tommotiid (Cambrian problematica) characters, notably a pair of agglutinated valves, enclosing a horseshoe-shaped lophophore, supported by a lower bipartite tubular attachment structure with a long pedicle with coelomic space. The terminal bulb of the pedicle provided anchorage in soft sediment. The discovery has important implications for the early evolution of lophotrochozoans, suggesting rooting of brachiopods into the sessile lophotrochozoans and the origination of their bivalved bauplan preceding the biomineralization of shell valves in crown brachiopods. PMID:24828016

  6. An early Cambrian agglutinated tubular lophophorate with brachiopod characters

    NASA Astrophysics Data System (ADS)

    Zhang, Z.-F.; Li, G.-X.; Holmer, L. E.; Brock, G. A.; Balthasar, U.; Skovsted, C. B.; Fu, D.-J.; Zhang, X.-L.; Wang, H.-Z.; Butler, A.; Zhang, Z.-L.; Cao, C.-Q.; Han, J.; Liu, J.-N.; Shu, D.-G.

    2014-05-01

    The morphological disparity of lophotrochozoan phyla makes it difficult to predict the morphology of the last common ancestor. Only fossils of stem groups can help discover the morphological transitions that occurred along the roots of these phyla. Here, we describe a tubular fossil Yuganotheca elegans gen. et sp. nov. from the Cambrian (Stage 3) Chengjiang Lagerstätte (Yunnan, China) that exhibits an unusual combination of phoronid, brachiopod and tommotiid (Cambrian problematica) characters, notably a pair of agglutinated valves, enclosing a horseshoe-shaped lophophore, supported by a lower bipartite tubular attachment structure with a long pedicle with coelomic space. The terminal bulb of the pedicle provided anchorage in soft sediment. The discovery has important implications for the early evolution of lophotrochozoans, suggesting rooting of brachiopods into the sessile lophotrochozoans and the origination of their bivalved bauplan preceding the biomineralization of shell valves in crown brachiopods.

  7. [Evaluation of gelatin particle agglutination method for detection of Treponema pallidum antibody].

    PubMed

    Deguchi, M; Hosotsubo, H; Yamashita, N; Ohmine, T; Asari, S

    1994-10-01

    Treponema pallidum hemagglutination (HA) is one of the most frequently used methods for the detection of Treponema pallidum (T. pallidum) antibodies. Recently, an innovative agglutination method using artificial carriers was newly developed, and is now available as a routine method. In order to compare the newly developed particle agglutination (PA) method (FUJIREBIO INC.) with the conventional HA method, T. pallidum antibody titers of numerous sera were measured by respective methods. In the stability study, reconstituted reagent was stable for at least three weeks. Sample inactivation (56 degrees C/30 min) demonstrated no effect on the test results. Among 800 sera, 132 (16.6%) positives (+), 633 (79.1%) negatives (-) and (4.3%) indeterminates (+) were obtained by HA method. Meanwhile, 144 (18.0%) positives (+), 627 (78.4%) negatives (-) and 29 (3.6%) indeterminates (+) were obtained by PA method. The correlation between PA and HA method was 97.8%, and the antibody titers obtained by PA method showed good correlation with HA method. Those samples which showed discrepancy between PA and HA method in the above study were further examined with fluorescent treponemal antibody-absorption (FTA-ABS) method. The results obtained from FTA-ABS method were almost consistent with those obtained from PA method. For respective syphilis patients in stage I and II, antibody titer was monitored by HA, PA and RPR method. The results indicated that changes in antibody titer obtained from PA method was approximately the same as the titer changes obtained from RPR method. Namely, PA method detected the presence of IgM earlier than HA method.(ABSTRACT TRUNCATED AT 250 WORDS)

  8. Red blood cell membrane viscoelasticity, agglutination and zeta potential measurements with double optical tweezers

    NASA Astrophysics Data System (ADS)

    Fontes, Adriana; Fernandes, Heloise P.; Barjas-Castro, Maria L.; de Thomaz, André A.; de Ysasa Pozzo, Liliana; Barbosa, Luiz C.; Cesar, Carlos L.

    2006-02-01

    The red blood cell (RBC) viscoelastic membrane contains proteins and glycolproteins embedded in, or attached, to a fluid lipid bilayer and are negatively charged, which creates a repulsive electric (zeta) potential between the cells and prevents their aggregation in the blood stream. There are techniques, however, to decrease the zeta potential to allow cell agglutination which are the basis of most of the tests of antigen-antibody interactions in blood banks. This report shows the use of a double optical tweezers to measure RBC membrane viscosity, agglutination and zeta potential. In our technique one of the optical tweezers trap a silica bead that binds strongly to a RBC at the end of a RBCs rouleaux and, at the same time, acts as a pico-Newton force transducer, after calibration through its displacement from the equilibrium position. The other optical tweezers trap the RBC at the other end. To measure the membrane viscosity the optical force is measured as a function of the velocity between the RBCs. To measure the adhesion the tweezers are slowly displaced apart until the RBCs disagglutination happens. The RBC zeta potential is measured in two complimentary ways, by the force on the silica bead attached to a single RBC in response to an applied electric field, and the conventional way, by the measurement of terminal velocity of the RBC after released from the optical trap. These two measurements provide information about the RBC charges and, also, electrolytic solution properties. We believe this can improve the methods of diagnosis in blood banks.

  9. International collaborative study of the endogenous reference gene LAT52 used for qualitative and quantitative analyses of genetically modified tomato.

    PubMed

    Yang, Litao; Zhang, Haibo; Guo, Jinchao; Pan, Liangwen; Zhang, Dabing

    2008-05-28

    One tomato ( Lycopersicon esculentum) gene, LAT52, has been proved to be a suitable endogenous reference gene for genetically modified (GM) tomato detection in a previous study. Herein are reported the results of a collaborative ring trial for international validation of the LAT52 gene as endogenous reference gene and its analytical systems; 14 GMO detection laboratories from 8 countries were invited, and results were finally received from 13. These data confirmed the species specificity by testing 10 plant genomic DNAs, less allelic variation and stable single copy number of the LAT52 gene, among 12 different tomato cultivars. Furthermore, the limit of detection of LAT52 qualitative PCR was proved to be 0.1%, which corresponded to 11 copies of haploid tomato genomic DNA, and the limit of quantification for the quantitative PCR system was about 10 copies of haploid tomato genomic DNA with acceptable PCR efficiency and linearity. Additionally, the bias between the test and true values of 8 blind samples ranged from 1.94 to 10.64%. All of these validated results indicated that the LAT52 gene is suitable for use as an endogenous reference gene for the identification and quantification of GM tomato and its derivates.

  10. [Methicillin resistance detection in Staphylococcus aureus: comparison between conventional methods and MRSA-Screen latex agglutination technique].

    PubMed

    Soloaga, R; Corso, A; Gagetti, P; Faccone, D; Galas, M

    2004-01-01

    Methicillin-resistant Staphylococcus aureus (MRSA) is a significant pathogen that has emerged over the last four decades, causing both nosocomial and community-acquired infections. Rapid and accurate detection of methicillin resistance in S. aureus is important for the use of appropriate antimicrobial therapy and for the control of nosocomial spread of MRSA strains. We evaluated the efficiency of conventional methods for detection of methicillin resistance such as the disk diffusion, agar dilution, oxacillin agar screen test, and the latex agglutination test MRSA-Screen latex, in 100 isolates of S. aureus, 79 mecA positive and 21 mecA negative. The MRSA-Screen latex (Denka Seiken, Niigata, Japón), is a latex agglutination method that detects the presence of PLP-2a, product of mecA gene in S. aureus. The PCR of the mecA gene was used as the "gold standard" for the evaluation of the different methods tested. The percentages of sensitivity and specificity were as follows: disk difusión 97 and 100%, agar dilution 97 and 95%, oxacillin agar screen test 100 and 100%, and MRSA-Screen latex, 100 and 100 %. All methods presented high sensitivity and specificity, but MRSA-Screen latex had the advantage of giving a reliable result, equivalent to PCR, in only 15 minutes.

  11. Momordica charantia seed lectin: toxicity, bacterial agglutination and antitumor properties.

    PubMed

    Kabir, Syed Rashel; Nabi, Md Mahamodun; Nurujjaman, Md; Abu Reza, Md; Alam, A H M Khurshid; Uz Zaman, Rokon; Khalid-Bin-Ferdaus, Khandaker Md; Amin, Ruhul; Khan, Md Masudul Hasan; Hossain, Md Anowar; Uddin, Md Salim; Mahmud, Zahid Hayat

    2015-03-01

    In last three decades, several studies were carried out on the D-galactose-specific lectin of Momordica charantia seeds (MCL). In the present study, in vitro growth inhibition (8-23 %) at different concentrations (6-24 μg/ml) of MCL was observed against Ehrlich ascites carcinoma (EAC) cells by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. MCL also showed 28, 45, and 75 % growth inhibitions against EAC cells when administered 1.2, 2.0, and 2.8 mg/kg/day (i.p.), respectively for five consequent days in vivo in mice. After lectin treatment, the level of red blood cell and hemoglobin was increased significantly with the decrease of white blood cell and maintained the normal level when compared with EAC-bearing control and normal mice without EAC cells. Although MCL caused cell cycle arrest at G0/G1 phase of EAC cells, any irregular shape or apoptotic morphological alterations in the lectin-treated EAC cells was not observed by an optical and fluorescence microscope. Lectin showed toxicity against brine shrimp nauplii with an LC50 value of 49.7 μg/ml. Four out of seven pathogenic bacteria were agglutinated by MCL in the absence of inhibitory sugar D-lactose/D-galactose. In conclusion, MCL showed strong cytotoxic effect and therefore can be used as a potent anticancer chemotherapeutic agent. PMID:25542240

  12. Human rotavirus detection by agglutination of antibody-coated erythrocytes.

    PubMed

    Sanekata, T; Okada, H

    1983-06-01

    We sensitized sheep erythrocytes (SRBC) with antibodies against human rotavirus strain Wa (SRBC-antiWa) and antibodies against calf rotavirus strain NCDV (SRBC-antiNCDV). These were readily agglutinated in the presence of homologous antigens, i.e., human rotavirus and calf rotavirus. By the hemagglutination of SRBC-antiWa and SRBC-antiNCDV (reverse passive hemagglutination [RPHA]), titration of rotavirus in extracts from feces of children suffering from diarrhea (61 specimens) was carried out. We found that the ratio of titers determined with SRBC-antiWa and SRBC-antiNCDV varied remarkably from specimen to specimen. This indicated that the antigenic determinants on human rotavirus in patients feces cross-react with antibodies against NCDV to varying extents. To express the cross-reactivity of human rotavirus with antibodies to NCDV, we propose a Wa/NCDV rotavirus index which can be calculated from the RPHA titer with SRBC-antiWa and SRBC-antiNCDV as follows: Wa/NCDV rotavirus index = (antiWa-RPHA titer of specimen/antiWa-RPHA titer of NCDV)/(antiNCDV-RPHA titer of specimen/antiNCDV-RPHA titer of NCDV).

  13. Commensal symbiosis between agglutinated polychaetes and sulfate-reducing bacteria.

    PubMed

    Guido, A; Mastandrea, A; Rosso, A; Sanfilippo, R; Tosti, F; Riding, R; Russo, F

    2014-05-01

    Pendant bioconstructions occur within submerged caves in the Plemmirio Marine Protected Area in SE Sicily, Italy. These rigid structures, here termed biostalactites, were synsedimentarily lithified by clotted-peloidal microbial carbonate that has a high bacterial lipid biomarker content with abundant compounds derived from sulfate-reducing bacteria. The main framework builders are polychaete serpulid worms, mainly Protula with subordinate Semivermilia and Josephella. These polychaetes have lamellar and/or fibrillar wall structure. In contrast, small agglutinated terebellid tubes, which are a minor component of the biostalactites, are discontinuous and irregular with a peloidal micritic microfabric. The peloids, formed by bacterial sulfate reduction, appear to have been utilized by terebellids to construct tubes in an environment where other particulate sediment is scarce. We suggest that the bacteria obtained food from the worms in the form of fecal material and/or from the decaying tissue of surrounding organisms and that the worms obtained peloidal micrite with which to construct their tubes, either as grains and/or as tube encompassing biofilm. Peloidal worm tubes have rarely been reported in the recent but closely resemble examples in the geological record that extend back at least to the early Carboniferous. This suggests a long-lived commensal relationship between some polychaete worms and heterotrophic, especially sulfate-reducing, bacteria.

  14. The First Fermi LAT Supernova Remnant Catalog

    NASA Astrophysics Data System (ADS)

    Acero, F.; Ackermann, M.; Ajello, M.; Baldini, L.; Ballet, J.; Barbiellini, G.; Bastieri, D.; Bellazzini, R.; Bissaldi, E.; Blandford, R. D.; Bloom, E. D.; Bonino, R.; Bottacini, E.; Brandt, T. J.; Bregeon, J.; Bruel, P.; Buehler, R.; Buson, S.; Caliandro, G. A.; Cameron, R. A.; Caputo, R.; Caragiulo, M.; Caraveo, P. A.; Casandjian, J. M.; Cavazzuti, E.; Cecchi, C.; Chekhtman, A.; Chiang, J.; Chiaro, G.; Ciprini, S.; Claus, R.; Cohen, J. M.; Cohen-Tanugi, J.; Cominsky, L. R.; Condon, B.; Conrad, J.; Cutini, S.; D'Ammando, F.; de Angelis, A.; de Palma, F.; Desiante, R.; Digel, S. W.; Di Venere, L.; Drell, P. S.; Drlica-Wagner, A.; Favuzzi, C.; Ferrara, E. C.; Franckowiak, A.; Fukazawa, Y.; Funk, S.; Fusco, P.; Gargano, F.; Gasparrini, D.; Giglietto, N.; Giommi, P.; Giordano, F.; Giroletti, M.; Glanzman, T.; Godfrey, G.; Gomez-Vargas, G. A.; Grenier, I. A.; Grondin, M.-H.; Guillemot, L.; Guiriec, S.; Gustafsson, M.; Hadasch, D.; Harding, A. K.; Hayashida, M.; Hays, E.; Hewitt, J. W.; Hill, A. B.; Horan, D.; Hou, X.; Iafrate, G.; Jogler, T.; Jóhannesson, G.; Johnson, A. S.; Kamae, T.; Katagiri, H.; Kataoka, J.; Katsuta, J.; Kerr, M.; Knödlseder, J.; Kocevski, D.; Kuss, M.; Laffon, H.; Lande, J.; Larsson, S.; Latronico, L.; Lemoine-Goumard, M.; Li, J.; Li, L.; Longo, F.; Loparco, F.; Lovellette, M. N.; Lubrano, P.; Magill, J.; Maldera, S.; Marelli, M.; Mayer, M.; Mazziotta, M. N.; Michelson, P. F.; Mitthumsiri, W.; Mizuno, T.; Moiseev, A. A.; Monzani, M. E.; Moretti, E.; Morselli, A.; Moskalenko, I. V.; Murgia, S.; Nemmen, R.; Nuss, E.; Ohsugi, T.; Omodei, N.; Orienti, M.; Orlando, E.; Ormes, J. F.; Paneque, D.; Perkins, J. S.; Pesce-Rollins, M.; Petrosian, V.; Piron, F.; Pivato, G.; Porter, T. A.; Rainò, S.; Rando, R.; Razzano, M.; Razzaque, S.; Reimer, A.; Reimer, O.; Renaud, M.; Reposeur, T.; Rousseau, R.; Saz Parkinson, P. M.; Schmid, J.; Schulz, A.; Sgrò, C.; Siskind, E. J.; Spada, F.; Spandre, G.; Spinelli, P.; Strong, A. W.; Suson, D. J.; Tajima, H.; Takahashi, H.; Tanaka, T.; Thayer, J. B.; Thompson, D. J.; Tibaldo, L.; Tibolla, O.; Torres, D. F.; Tosti, G.; Troja, E.; Uchiyama, Y.; Vianello, G.; Wells, B.; Wood, K. S.; Wood, M.; Yassine, M.; den Hartog, P. R.; Zimmer, S.

    2016-05-01

    To uniformly determine the properties of supernova remnants (SNRs) at high energies, we have developed the first systematic survey at energies from 1 to 100 GeV using data from the Fermi Large Area Telescope (LAT). Based on the spatial overlap of sources detected at GeV energies with SNRs known from radio surveys, we classify 30 sources as likely GeV SNRs. We also report 14 marginal associations and 245 flux upper limits. A mock catalog in which the positions of known remnants are scrambled in Galactic longitude allows us to determine an upper limit of 22% on the number of GeV candidates falsely identified as SNRs. We have also developed a method to estimate spectral and spatial systematic errors arising from the diffuse interstellar emission model, a key component of all Galactic Fermi LAT analyses. By studying remnants uniformly in aggregate, we measure the GeV properties common to these objects and provide a crucial context for the detailed modeling of individual SNRs. Combining our GeV results with multiwavelength (MW) data, including radio, X-ray, and TeV, we demonstrate the need for improvements to previously sufficient, simple models describing the GeV and radio emission from these objects. We model the GeV and MW emission from SNRs in aggregate to constrain their maximal contribution to observed Galactic cosmic rays.

  15. The Cenozoic Diversity of Agglutinated Foraminifera - Evidence for a late Oligocene to early Miocene diversification event

    NASA Astrophysics Data System (ADS)

    Kaminski, Michael; Setoyama, Eiichi; Kender, Sev; Cetean, Claudia

    2014-05-01

    The agglutinated foraminifera are among the most abundant micro-organisms in the deep marine environment and have a diversity record extending back to the late Precambrian. We present an updated diversity curve for agglutinated foraminiferal genera based on the stratigraphic ranges of all the agglutinated genera recognized as valid in the classification of Kaminski (2014). The data set for this analysis is based on the stratigraphic ranges of agglutinated genera published in Foraminiferal Genera and their Classification, which has been subsequently updated based on published studies and our new observations. The mean standing diversity of agglutinated foraminiferal genera was compiled by counting the number of boundary crossers rather than the number of genera in each stage. In this study, we report the stratigraphic and geographical occurrence of a benthic foraminiferal diversification event that has previously received little attention. In the latest Oligocene to earliest Miocene a number of trochospiral agglutinated genera with alveolar or canaliculate walls first appeared in the fossil record. Our studies of late Oligocene of the Congo fan, offshore Angola (Kender et al., 2008; Cetean and Kaminski, 2011) have revealed a diverse assemblage that includes new taxa of deep-water agglutinated foraminifera. In a biostratigraphic study of the Miocene foraminiferal assemblages Kender et al. (2008) noted steadily increasing diversity and proportions of infaunal agglutinated foraminiferal morphotypes over the lower Miocene interval. The proportion of infaunal agglutinated foraminifera assigned to the order Textularida increased dramatically in the lower mid-Miocene, suggesting expansion of the oxygen minimum zone into deeper waters. In addition to the trochospiral alveolar genera, several species of Reticulophragmium and Cyclammina display rapid diversification into numerous separate lineages that are at present not reflected in our generic diversity record owing to

  16. Fermi LAT Observations of Cosmic-Ray Electrons

    NASA Technical Reports Server (NTRS)

    Moiseev, Alexander

    2011-01-01

    Designed as a gamma-ray instrument, the LAT is a capable detector of high energy cosmic ray electrons. The LAT is composed of a 4x4 array of identical towers. Each tower has a Tracker and a Calorimeter module. Entire LAT is covered by segmented Anti-Coincidence Detector (ACD). The electron data analysis is based on that developed for photons. The main challenge is to identify and separate electrons from all other charged species, mainly CR protons (for gamma-ray analysis this is provided by the Anti-Coincidence Detector)

  17. Prevalence of agglutinating antibodies to Toxoplasma gondii in adult and fetal mule deer (Odocoileus hemionus) from Nebraska.

    PubMed

    Lindsay, David S; McKown, Richard D; DiCristina, Jennifer A; Jordan, Carly N; Mitchell, Sheila; Oates, David W; Sterner, Mauritz C

    2005-12-01

    Toxoplasma gondii is an apicomplexan parasite of mammals and birds. Herbivores acquire postnatal infection by ingesting oocysts from contaminated food or water. Toxoplasma gondii infection is common in white-tailed deer, Odocoileus virginianus, but little is known about the prevalence of infection in mule deer, O. hemionus. We examined sera from 89 mule deer from Nebraska for agglutinating antibodies to T. gondii using the modified direct agglutination test (MAT) with formalin-fixed tachyzoites as antigen. Thirty-one (35%) of the samples were positive at dilutions of > or = 1:25. Samples were examined from 29 fetuses from these mule deer and none were positive in the MAT. Sera from 14 white-tailed deer from Nebraska were also examined and 6 (43%) were positive for T. gondii. Samples were examined from 5 fetuses from these white-tailed deer and none was positive in the MAT. Our results in both deer species from Nebraska are similar to studies conducted in white-tailed deer from other regions of the United States. Our findings indicate that mule deer are frequently infected with T. gondii and that mule-deer meat may be a source of human infection.

  18. Chandra and Swift Observations of Unidentified Fermi-LAT Objects

    NASA Astrophysics Data System (ADS)

    Donato, Davide; Cheung, T.; Gehrels, N.

    2010-03-01

    In the last year we targeted some of the unidentified Fermi-LAT objects (UFOs) at high Galactic latitude with Chandra and Swift in order to determine the basic properties (positions, fluxes, hardness ratios) of all X-ray sources within the Fermi-LAT localization circles. These satellites enable us to detect the X-ray conterparts with a flux limit that is at least an order of magnitude lower than achieved in extant RASS data and to further follow-up at other wavelengths, with the ultimate goal to reveal the nature of these enigmatic gamma-ray sources. Here we present the results obtained with 5 Chandra pointings of high Galactic latitude UFOs in the Fermi-LAT 3-months bright source list. The association of detected X-ray sources within the improved 11-months Fermi-LAT localization circles with available optical and radio observations is discussed.

  19. Laser-assisted tympanostomy (LAT) in adult individuals

    NASA Astrophysics Data System (ADS)

    Prokopakis, E. P.; Lachanas, V. A.; Helidonis, Emmanuel S.; Velegrakis, G.

    2004-06-01

    Objectives: To assess outcome, in adult individuals undergone Laser Assisted Tympanostomy (LAT) without ventilation tube placement. Method: LAT was performed on a total of 95 ears (72 individuals). Indications included serous otitis media with effusion (44 ears/31 patients), eustachian tube dysfunction (32 ears/24 patients), acute otitis media (13 ears/11 patients), and endoscopic visualization of the middle ear (6 ears/6 patients). Results: Middle ear disease was resolved after the closure of tympanostomy in 48% of patients with serous otitis media with effusion. In 78% of patients with Eustachian tube dysfunction symptoms were diminished. All patients with acute otitis media had a satisfactory outcome. LAT was found quite effective in patients undergoing middle ear endoscopy. Conclusion: LAT without ventilation tubes provides a safe alternative surgical option in adult patients in certain cases. The selection criteria for this procedure are addressed in detail.

  20. [Detection of toxoplasma-specific IgM antibodies--comparison with the ISAGA (immunosorbent agglutination assay) and immunofluorescence results].

    PubMed

    Saathoff, M; Seitz, H M

    1985-01-01

    Serum samples from 702 persons were examined for Toxoplasma-specific IgM-antibodies using the immunosorbent agglutination assay (ISAGA) and the immunofluorescence-test (IIFT). 250 samples showed a positive reaction in the Sabin-Feldman-test (SFT) with titers greater than or equal to 1: 1 024, 58% were positive in ISAGA and 36% in the IIFT. Samples of persons with acute Toxoplasma-infection, showed high titers in the ISAGA and SFT as well, even in cases where the IgM-IIFT was negative. SFT-negative sera and others with weakly-positive reactions and also rheuma-positive samples were negative in the ISAGA. It is discussed how far it is possible to determine the duration of the Toxoplasma infection by applying the ISAGA in combination with other antibody tests.

  1. Effect of C-Terminal Protein Tags on Pentitol and l-Arabinose Transport by Ambrosiozyma monospora Lat1 and Lat2 Transporters in Saccharomyces cerevisiae

    PubMed Central

    Richard, Peter; Valkonen, Mari; Viljanen, Kaarina

    2014-01-01

    Functional expression in heterologous hosts is often less successful for integral membrane proteins than for soluble proteins. Here, two Ambrosiozyma monospora transporters were successfully expressed in Saccharomyces cerevisiae as tagged proteins. Growth of A. monospora on l-arabinose instead of glucose caused transport activities of l-arabinose, l-arabitol, and ribitol, measured using l-[1-3H]arabinose, l-[14C]arabitol, and [14C]ribitol of demonstrated purity. A. monospora LAT1 and LAT2 genes were cloned earlier by using their ability to improve the growth of genetically engineered Saccharomyces cerevisiae on l-arabinose. However, the l-arabinose and pentitol transport activities of S. cerevisiae carrying LAT1 or LAT2 are only slightly greater than those of control strains. S. cerevisiae carrying the LAT1 or LAT2 gene fused in frame to the genes for green fluorescent protein (GFP) or red fluorescent protein (mCherry) or adenylate kinase (AK) exhibited large (>3-fold for LAT1; >20-fold for LAT2) increases in transport activities. Lat1-mCherry transported l-arabinose with high affinity (Km ≈ 0.03 mM) and l-arabitol and ribitol with very low affinity (Km ≥ 75 mM). The Lat2-GFP, Lat2-mCherry, and Lat2-AK fusion proteins could not transport l-arabinose but were high-affinity pentitol transporters (Kms ≈ 0.2 mM). The l-arabinose and pentitol transport activities of A. monospora could not be completely explained by any combination of the observed properties of tagged Lat1 and Lat2, suggesting either that tagging and expression in a foreign membrane alters the transport kinetics of Lat1 and/or Lat2 or that A. monospora contains at least one more l-arabinose transporter. PMID:24561586

  2. Effect of C-terminal protein tags on pentitol and L-arabinose transport by Ambrosiozyma monospora Lat1 and Lat2 transporters in Saccharomyces cerevisiae.

    PubMed

    Londesborough, John; Richard, Peter; Valkonen, Mari; Viljanen, Kaarina

    2014-05-01

    Functional expression in heterologous hosts is often less successful for integral membrane proteins than for soluble proteins. Here, two Ambrosiozyma monospora transporters were successfully expressed in Saccharomyces cerevisiae as tagged proteins. Growth of A. monospora on l-arabinose instead of glucose caused transport activities of l-arabinose, l-arabitol, and ribitol, measured using l-[1-(3)H]arabinose, l-[(14)C]arabitol, and [(14)C]ribitol of demonstrated purity. A. monospora LAT1 and LAT2 genes were cloned earlier by using their ability to improve the growth of genetically engineered Saccharomyces cerevisiae on l-arabinose. However, the l-arabinose and pentitol transport activities of S. cerevisiae carrying LAT1 or LAT2 are only slightly greater than those of control strains. S. cerevisiae carrying the LAT1 or LAT2 gene fused in frame to the genes for green fluorescent protein (GFP) or red fluorescent protein (mCherry) or adenylate kinase (AK) exhibited large (>3-fold for LAT1; >20-fold for LAT2) increases in transport activities. Lat1-mCherry transported l-arabinose with high affinity (Km ≈ 0.03 mM) and l-arabitol and ribitol with very low affinity (Km ≥ 75 mM). The Lat2-GFP, Lat2-mCherry, and Lat2-AK fusion proteins could not transport l-arabinose but were high-affinity pentitol transporters (Kms ≈ 0.2 mM). The l-arabinose and pentitol transport activities of A. monospora could not be completely explained by any combination of the observed properties of tagged Lat1 and Lat2, suggesting either that tagging and expression in a foreign membrane alters the transport kinetics of Lat1 and/or Lat2 or that A. monospora contains at least one more l-arabinose transporter.

  3. Rheologic characterization of vegetal lectins by dissociation of induced erythrocyte agglutinates.

    PubMed

    Rasia, R J; Valverde, J R; Gentils, M; Cauchois, C; Stoltz, J F

    1997-01-01

    Energy evolved from hemagglutination reaction or spent in dissociating erythrocyte agglutinates has been proved to be an excellent parameter for analyzing cell-cell interactions mediated by bridging molecules such as antibodies or lectins. We developed a new rheo-optical method to estimate the energy of dissociation of red blood cell agglutinates. In a Couette shear field agglutinates can be dissociated until a suspension of monodispersed cells is obtained. Intensity of light backscattered by suspended agglutinates increases during their mechanical dissociation. Variation of backscattered light intensity correlates with the energy spent in the process. The adhesive energy of erythrocyte agglutination induced by lectins has been estimated by applying this method. Two specific lectins (Dolichus Biflorus agglutinin and Ulex Europaeus agglutinin) and a new lectin obtained from Amarantus Cruentus seeds which specificity is unknown were studied. Results obtained in this work for Dolichus Biflorus lectin are comparable with values published by other authors. An asymptotic decrease of adhesive energy was observed when the mechanical dissociation was applied several times on the same sample. Our results suggest that the cell detachment is accompanied by the extraction of membrane receptors. This finding is consistent with results obtained by other authors.

  4. Induction of inducible nitric oxide synthase expression in ammonia-exposed cultured astrocytes is coupled to increased arginine transport by upregulated y(+)LAT2 transporter.

    PubMed

    Zielińska, Magdalena; Milewski, Krzysztof; Skowrońska, Marta; Gajos, Anna; Ziemińska, Elżbieta; Beręsewicz, Andrzej; Albrecht, Jan

    2015-12-01

    One of the aspects of ammonia toxicity to brain cells is increased production of nitric oxide (NO) by NO synthases (NOSs). Previously we showed that ammonia increases arginine (Arg) uptake in cultured rat cortical astrocytes specifically via y(+)L amino acid transport system, by activation of its member, a heteromeric y(+)LAT2 transporter. Here, we tested the hypothesis that up-regulation of y(+)LAT2 underlies ammonia-dependent increase of NO production via inducible NOS (iNOS) induction, and protein nitration. Treatment of rat cortical astrocytes for 48 with 5 mM ammonium chloride ('ammonia') (i) increased the y(+)L-mediated Arg uptake, (ii) raised the expression of iNOS and endothelial NOS (eNOS), (iii) stimulated NO production, as manifested by increased nitrite+nitrate (Griess) and/or nitrite alone (chemiluminescence), and consequently, (iv) evoked nitration of tyrosine residues of proteins in astrocytes. Except for the increase of eNOS, all the above described effects of ammonia were abrogated by pre-treatment of astrocytes with either siRNA silencing of the Slc7a6 gene coding for y(+)LAT2 protein, or antibody to y(+)LAT2, indicating their strict coupling to y(+)LAT2 activity. Moreover, induction of y(+)LAT2 expression by ammonia was sensitive to Nf-κB inhibitor, BAY 11-7085, linking y(+)LAT2 upregulation to the Nf-κB activation in this experimental setting as reported earlier and here confirmed. Importantly, ammonia did not affect y(+)LAT2 expression nor y(+)L-mediated Arg uptake activity in the cultured cerebellar neurons, suggesting astroglia-specificity of the above described mechanism. The described coupling of up-regulation of y(+)LAT2 transporter with iNOS in ammonia-exposed astrocytes may be considered as a mechanism to ensure NO supply for protein nitration. Ammonia (NH4(+)) increases the expression and activity of the L-arginine (Arg) transporter (Arg/neutral amino acids [NAA] exchanger) y(+)LAT2 in cultured rat cortical astrocytes by a mechanism

  5. Induction of inducible nitric oxide synthase expression in ammonia-exposed cultured astrocytes is coupled to increased arginine transport by upregulated y(+)LAT2 transporter.

    PubMed

    Zielińska, Magdalena; Milewski, Krzysztof; Skowrońska, Marta; Gajos, Anna; Ziemińska, Elżbieta; Beręsewicz, Andrzej; Albrecht, Jan

    2015-12-01

    One of the aspects of ammonia toxicity to brain cells is increased production of nitric oxide (NO) by NO synthases (NOSs). Previously we showed that ammonia increases arginine (Arg) uptake in cultured rat cortical astrocytes specifically via y(+)L amino acid transport system, by activation of its member, a heteromeric y(+)LAT2 transporter. Here, we tested the hypothesis that up-regulation of y(+)LAT2 underlies ammonia-dependent increase of NO production via inducible NOS (iNOS) induction, and protein nitration. Treatment of rat cortical astrocytes for 48 with 5 mM ammonium chloride ('ammonia') (i) increased the y(+)L-mediated Arg uptake, (ii) raised the expression of iNOS and endothelial NOS (eNOS), (iii) stimulated NO production, as manifested by increased nitrite+nitrate (Griess) and/or nitrite alone (chemiluminescence), and consequently, (iv) evoked nitration of tyrosine residues of proteins in astrocytes. Except for the increase of eNOS, all the above described effects of ammonia were abrogated by pre-treatment of astrocytes with either siRNA silencing of the Slc7a6 gene coding for y(+)LAT2 protein, or antibody to y(+)LAT2, indicating their strict coupling to y(+)LAT2 activity. Moreover, induction of y(+)LAT2 expression by ammonia was sensitive to Nf-κB inhibitor, BAY 11-7085, linking y(+)LAT2 upregulation to the Nf-κB activation in this experimental setting as reported earlier and here confirmed. Importantly, ammonia did not affect y(+)LAT2 expression nor y(+)L-mediated Arg uptake activity in the cultured cerebellar neurons, suggesting astroglia-specificity of the above described mechanism. The described coupling of up-regulation of y(+)LAT2 transporter with iNOS in ammonia-exposed astrocytes may be considered as a mechanism to ensure NO supply for protein nitration. Ammonia (NH4(+)) increases the expression and activity of the L-arginine (Arg) transporter (Arg/neutral amino acids [NAA] exchanger) y(+)LAT2 in cultured rat cortical astrocytes by a mechanism

  6. The first Fermi LAT supernova remnant catalog

    DOE PAGES

    Acero, F.

    2016-05-16

    To uniformly determine the properties of supernova remnants (SNRs) at high energies, we have developed the first systematic survey at energies from 1 to 100 GeV using data from the Fermi Large Area Telescope. Based on the spatial overlap of sources detected at GeV energies with SNRs known from radio surveys, we classify 30 sources as likely GeV SNRs. We also report 14 marginal associations and 245 flux upper limits. A mock catalog in which the positions of known remnants are scrambled in Galactic longitude, allows us to determine an upper limit of 22% on the number of GeV candidatesmore » falsely identified as SNRs. We have also developed a method to estimate spectral and spatial systematic errors arising from the diffuse interstellar emission model, a key component of all Galactic Fermi LAT analyses. By studying remnants uniformly in aggregate, we measure the GeV properties common to these objects and provide a crucial context for the detailed modeling of individual SNRs. Combining our GeV results with multiwavelength (MW) data, including radio, X-ray, and TeV, demonstrates the need for improvements to previously sufficient, simple models describing the GeV and radio emission from these objects. As a result, we model the GeV and MW emission from SNRs in aggregate to constrain their maximal contribution to observed Galactic cosmic rays.« less

  7. LAT-1 activity of meta-substituted phenylalanine and tyrosine analogs.

    PubMed

    Augustyn, Evan; Finke, Karissa; Zur, Arik A; Hansen, Logan; Heeren, Nathan; Chien, Huan-Chieh; Lin, Lawrence; Giacomini, Kathleen M; Colas, Claire; Schlessinger, Avner; Thomas, Allen A

    2016-06-01

    The transporter protein Large-neutral Amino Acid Transporter 1 (LAT-1, SLC7A5) is responsible for transporting amino acids such as tyrosine and phenylalanine as well as thyroid hormones, and it has been exploited as a drug delivery mechanism. Recently its role in cancer has become increasingly appreciated, as it has been found to be up-regulated in many different tumor types, and its expression levels have been correlated with prognosis. Substitution at the meta position of aromatic amino acids has been reported to increase affinity for LAT-1; however, the SAR for this position has not previously been explored. Guided by newly refined computational models of the binding site, we hypothesized that groups capable of filling a hydrophobic pocket would increase binding to LAT-1, resulting in improved substrates relative to parent amino acid. Tyrosine and phenylalanine analogs substituted at the meta position with halogens, alkyl and aryl groups were synthesized and tested in cis-inhibition and trans-stimulation cell assays to determine activity. Contrary to our initial hypothesis we found that lipophilicity was correlated with diminished substrate activity and increased inhibition of the transporter. The synthesis and SAR of meta-substituted phenylalanine and tyrosine analogs is described.

  8. LAT-1 activity of meta-substituted phenylalanine and tyrosine analogs.

    PubMed

    Augustyn, Evan; Finke, Karissa; Zur, Arik A; Hansen, Logan; Heeren, Nathan; Chien, Huan-Chieh; Lin, Lawrence; Giacomini, Kathleen M; Colas, Claire; Schlessinger, Avner; Thomas, Allen A

    2016-06-01

    The transporter protein Large-neutral Amino Acid Transporter 1 (LAT-1, SLC7A5) is responsible for transporting amino acids such as tyrosine and phenylalanine as well as thyroid hormones, and it has been exploited as a drug delivery mechanism. Recently its role in cancer has become increasingly appreciated, as it has been found to be up-regulated in many different tumor types, and its expression levels have been correlated with prognosis. Substitution at the meta position of aromatic amino acids has been reported to increase affinity for LAT-1; however, the SAR for this position has not previously been explored. Guided by newly refined computational models of the binding site, we hypothesized that groups capable of filling a hydrophobic pocket would increase binding to LAT-1, resulting in improved substrates relative to parent amino acid. Tyrosine and phenylalanine analogs substituted at the meta position with halogens, alkyl and aryl groups were synthesized and tested in cis-inhibition and trans-stimulation cell assays to determine activity. Contrary to our initial hypothesis we found that lipophilicity was correlated with diminished substrate activity and increased inhibition of the transporter. The synthesis and SAR of meta-substituted phenylalanine and tyrosine analogs is described. PMID:27106710

  9. Timing and Fermi LAT Analysis of Four Millisecond Pulsars Discovered in Parkes Radio Searches of Gamma-ray Sources

    NASA Astrophysics Data System (ADS)

    Ray, Paul S.; Ransom, Scott M.; Camilo, Fernando M.; Kerr, Matthew; Reynolds, John; Sarkissian, John; Freire, Paulo; Thankful Cromartie, H.; Barr, Ewan D.

    2016-01-01

    We present phase-connected timing solutions for four binary millisecond pulsars discovered in searches of Fermi LAT gamma-ray sources using the Parkes radio telescope. Follow-up timing observations of PSRs J0955-6150, J1012-4235, J1036-8317, and J1946-5403 have yielded timing models with precise orbital and astrometric parameters. For each pulsar, we also did a gamma-ray spectral analysis using LAT Pass 8 data and generated photon probabilities for use in a weighted H-test pulsation test. In all 4 cases, we detect significant gamma-ray pulsations, confirming the identification with the gamma-ray source originally targeted in the discovery observations. We describe the results of the pulse timing and gamma-ray spectral and timing analysis and the characteristics of each of the systems. The Fermi-LAT Collaboration acknowledges support for LAT development, operation and data analysis from NASA and DOE (United States), CEA/Irfu and IN2P3/CNRS (France), ASI and INFN (Italy), MEXT, KEK, and JAXA (Japan), and the K.A. Wallenberg Foundation, the Swedish Research Council and the National Space Board (Sweden). Science analysis support in the operations phase from INAF (Italy) and CNES (France) is also gratefully acknowledged. NRL participation was funded by NASA.

  10. Agglutinates as recorders of fossil soil compositions. [of Apollo 17 lunar probes

    NASA Technical Reports Server (NTRS)

    Taylor, G. J.; Wentworth, S.; Warner, R. D.; Keil, K.

    1978-01-01

    The composition of agglutinates in polished sections of the Apollo 17 drill core was studied in an attempt to deduce the nature of the Taurus-Littrow valley regolith prior to the formation of the Camelot and Central Cluster craters. The agglutinate compositions in the soils differed from the host soil compositions except for samples from the North Massif. Local materials from the valley floor and the massifs appear to form the pre-Central Cluster regolith. It is also shown that chemical mixing models for bulk soil compositions can be misleading unless the petrologic characteristics of each soil are taken into account.

  11. Fermi-LAT observations of the Sagittarius B complex

    NASA Astrophysics Data System (ADS)

    Yang, Rui-zhi; Jones, David I.; Aharonian, Felix

    2015-08-01

    Aims: We use 5 years of Fermi-LAT data towards the Galactic-centre giant molecular cloud complex, Sagittarius B, to test questions of how well-mixed the Galactic component of cosmic rays are and what the level of the cosmic-ray sea in different parts of the Galaxy is. Methods: We use dust-opacity maps from the Planck satellite to obtain independent methods for background subtraction and an estimate for the mass of the region. We then present high-quality spectra of γ-ray emission from 0.3 to 30 GeV and obtain an estimate of the cosmic-ray spectrum from the region. Results: We obtain an estimate of the mass of the region of 1.5 ± 0.2 × 107M⊙ using the Planck data, which agrees well with molecular-line-derived estimates for the same region. We find that the γ-ray flux from this region is fitted well with a cosmic-ray spectrum that is the same as is observed locally, with evidence of a small over-density at intermediate (1-10 GeV) energies. Conclusions: We conclude that the γ-ray and cosmic-ray spectrum in the region can be well-fitted using a local cosmic-ray spectrum.

  12. Boronophenylalanine, a boron delivery agent for boron neutron capture therapy, is transported by ATB0,+, LAT1 and LAT2.

    PubMed

    Wongthai, Printip; Hagiwara, Kohei; Miyoshi, Yurika; Wiriyasermkul, Pattama; Wei, Ling; Ohgaki, Ryuichi; Kato, Itsuro; Hamase, Kenji; Nagamori, Shushi; Kanai, Yoshikatsu

    2015-03-01

    The efficacy of boron neutron capture therapy relies on the selective delivery of boron carriers to malignant cells. p-Boronophenylalanine (BPA), a boron delivery agent, has been proposed to be localized to cells through transporter-mediated mechanisms. In this study, we screened aromatic amino acid transporters to identify BPA transporters. Human aromatic amino acid transporters were functionally expressed in Xenopus oocytes and examined for BPA uptake and kinetic parameters. The roles of the transporters in BPA uptake were characterized in cancer cell lines. For the quantitative assessment of BPA uptake, HPLC was used throughout the study. Among aromatic amino acid transporters, ATB(0,+), LAT1 and LAT2 were found to transport BPA with Km values of 137.4 ± 11.7, 20.3 ± 0.8 and 88.3 ± 5.6 μM, respectively. Uptake experiments in cancer cell lines revealed that the LAT1 protein amount was the major determinant of BPA uptake at 100 μM, whereas the contribution of ATB(0,+) became significant at 1000 μM, accounting for 20-25% of the total BPA uptake in MCF-7 breast cancer cells. ATB(0,+), LAT1 and LAT2 transport BPA at affinities comparable with their endogenous substrates, suggesting that they could mediate effective BPA uptake in vivo. The high and low affinities of LAT1 and ATB(0,+), respectively, differentiate their roles in BPA uptake. ATB(0,+), as well as LAT1, could contribute significantly to the tumor accumulation of BPA at clinical dose.

  13. Outbreak of Uncommon O4 Non-Agglutinating Salmonella Typhimurium Linked to Minced Pork, Saxony-Anhalt, Germany, January to April 2013

    PubMed Central

    Helmeke, Carina; Kohlstock, Claudia; Prager, Rita; Tietze, Erhard; Rabsch, Wolfgang; Karagiannis, Ioannis; Werber, Dirk; Frank, Christina; Fruth, Angelika

    2015-01-01

    Introduction In January 2013, the National Reference Centre for Salmonella (NRC) detected a salmonellosis cluster in Saxony-Anhalt, Germany, caused by uncommon O4 non-agglutinating, monophasic Salmonella (S.) Typhimurium DT193. Circulating predominant monophasic S. Typhimurium DT193 clones typically display resistance phenotype ASSuT. We investigated common exposures to control the outbreak, and conducted microbiological investigations to assess the strains’ phenotype. Methods We conducted a case-control study defining cases as persons living or working in Saxony-Anhalt diagnosed with the O4 non-agglutinating strain between January and March 2013. We selected two controls contemporarily reported with norovirus infection, frequency-matched on residence and age group, per case. We interviewed regarding food consumption, especially pork and its place of purchase. We calculated odds ratios (ORs) with 95% confidence intervals (95% CI) using logistic regression. The NRC investigated human and food isolates by PCR, SDS-PAGE, MLST, PFGE, MLVA and susceptibility testing. Results Altogether, 68 O4 non-agglutinating human isolates were confirmed between January and April 2013. Of those, 61 were assigned to the outbreak (median age 57 years, 44% female); 83% cases ≥ 60 years were hospitalized. Eating raw minced pork from butcheries within 3 days was associated with disease (31 cases, 28 controls; OR adjusted for sex: 3.6; 95% CI: 1.0-13). Phage type DT193 and MLST ST34 were assigned, and isolates’ lipopolysaccharide (LPS) matched control strains. Isolates linked to Saxony-Anhalt exhibited PFGE type 5. ASSuT- and ACSSuT phenotype proportions were 34 and 39% respectively; 54% were resistant to chloramphenicol. Three pork isolates matched the outbreak strain. Discussion Raw minced pork was the most likely infection vehicle in this first reported outbreak caused by O4 non-agglutinating, mostly chloramphenicol-resistant S. Typhimurium DT193. High hospitalization proportions

  14. The First FERMI-LAT Gamma-Ray Burst Catalog

    NASA Technical Reports Server (NTRS)

    Ackermann, M.; Ajello, M.; Asano, K.; Axelsson, M.; Baldini, L.; Ballet, J.; Barbiellini, G.; Bastieri, D.; Bechtol, K.; Bellazzini, R.; Bhat, P. N.; Bissaldi, E.; Bloom, E. D.; Bonamente, E.; Bonnell, J.; Bouvier, A.; Brandt, T. J.; Bregeon, J.; Brigida, M.; Bruel, P.; Burgess, J. Michael; Buson, S.; Byrne, D.; Caliandro, G. A.; Ferrara, E. C.; Gehrels, N.; Guiriec, S.; McEnery, J. E.; Nemmen, R.; Perkins, J. S.; Racusin, J. L.; Thompson, D. J.; Kouveliotou, C.

    2013-01-01

    In three years of observations since the beginning of nominal science operations in 2008 August, the Large Area Telescope (LAT) on board the Fermi Gamma-Ray Space Telescope has observed high-energy great than (20 MeV) gamma-ray emission from 35 gamma-ray bursts (GRBs). Among these, 28 GRBs have been detected above 100 MeV and 7 GRBs above approximately 20 MeV. The first Fermi-LAT catalog of GRBs is a compilation of these detections and provides a systematic study of high-energy emission from GRBs for the first time. To generate the catalog, we examined 733 GRBs detected by the Gamma-Ray Burst Monitor (GBM) on Fermi and processed each of them using the same analysis sequence. Details of the methodology followed by the LAT collaboration for the GRB analysis are provided. We summarize the temporal and spectral properties of the LAT-detected GRBs. We also discuss characteristics of LAT-detected emission such as its delayed onset and longer duration compared with emission detected by the GBM, its power-law temporal decay at late times, and the fact that it is dominated by a power-law spectral component that appears in addition to the usual Band model.

  15. THE FIRST FERMI-LAT GAMMA-RAY BURST CATALOG

    SciTech Connect

    Ackermann, M.; Ajello, M.; Asano, K.; Axelsson, M.; Baldini, L.; Ballet, J.; Bastieri, D.; Bechtol, K.; Bloom, E. D.; Bellazzini, R.; Bregeon, J.; Bhat, P. N.; Bissaldi, E.; Bonamente, E.; Bonnell, J.; Brandt, T. J.; Bouvier, A. E-mail: giacomov@slac.stanford.edu; and others

    2013-11-01

    In three years of observations since the beginning of nominal science operations in 2008 August, the Large Area Telescope (LAT) on board the Fermi Gamma-Ray Space Telescope has observed high-energy (∼> 20 MeV) γ-ray emission from 35 gamma-ray bursts (GRBs). Among these, 28 GRBs have been detected above 100 MeV and 7 GRBs above ∼20 MeV. The first Fermi-LAT catalog of GRBs is a compilation of these detections and provides a systematic study of high-energy emission from GRBs for the first time. To generate the catalog, we examined 733 GRBs detected by the Gamma-Ray Burst Monitor (GBM) on Fermi and processed each of them using the same analysis sequence. Details of the methodology followed by the LAT collaboration for the GRB analysis are provided. We summarize the temporal and spectral properties of the LAT-detected GRBs. We also discuss characteristics of LAT-detected emission such as its delayed onset and longer duration compared with emission detected by the GBM, its power-law temporal decay at late times, and the fact that it is dominated by a power-law spectral component that appears in addition to the usual Band model.

  16. Fermi-LAT Observations of the LIGO Event GW150914

    NASA Astrophysics Data System (ADS)

    Ackermann, M.; Ajello, M.; Albert, A.; Anderson, B.; Arimoto, M.; Atwood, W. B.; Axelsson, M.; Baldini, L.; Ballet, J.; Barbiellini, G.; Baring, M. G.; Bastieri, D.; Becerra Gonzalez, J.; Bellazzini, R.; Bissaldi, E.; Blandford, R. D.; Bloom, E. D.; Bonino, R.; Bottacini, E.; Brandt, T. J.; Bregeon, J.; Britto, R. J.; Bruel, P.; Buehler, R.; Burnett, T. H.; Buson, S.; Caliandro, G. A.; Cameron, R. A.; Caputo, R.; Caragiulo, M.; Caraveo, P. A.; Casandjian, J. M.; Cavazzuti, E.; Charles, E.; Chekhtman, A.; Chiang, J.; Chiaro, G.; Ciprini, S.; Cohen-Tanugi, J.; Cominsky, L. R.; Condon, B.; Costanza, F.; Cuoco, A.; Cutini, S.; D’Ammando, F.; de Palma, F.; Desiante, R.; Digel, S. W.; Di Lalla, N.; Di Mauro, M.; Di Venere, L.; Domínguez, A.; Drell, P. S.; Dubois, R.; Dumora, D.; Favuzzi, C.; Fegan, S. J.; Ferrara, E. C.; Franckowiak, A.; Fukazawa, Y.; Funk, S.; Fusco, P.; Gargano, F.; Gasparrini, D.; Gehrels, N.; Giglietto, N.; Giomi, M.; Giommi, P.; Giordano, F.; Giroletti, M.; Glanzman, T.; Godfrey, G.; Gomez-Vargas, G. A.; Granot, J.; Green, D.; Grenier, I. A.; Grondin, M.-H.; Grove, J. E.; Guillemot, L.; Guiriec, S.; Hadasch, D.; Harding, A. K.; Hays, E.; Hewitt, J. W.; Hill, A. B.; Horan, D.; Jogler, T.; Jóhannesson, G.; Kamae, T.; Kensei, S.; Kocevski, D.; Kuss, M.; La Mura, G.; Larsson, S.; Latronico, L.; Lemoine-Goumard, M.; Li, J.; Li, L.; Longo, F.; Loparco, F.; Lovellette, M. N.; Lubrano, P.; Madejski, G. M.; Magill, J.; Maldera, S.; Manfreda, A.; Marelli, M.; Mayer, M.; Mazziotta, M. N.; McEnery, J. E.; Meyer, M.; Michelson, P. F.; Mirabal, N.; Mizuno, T.; Moiseev, A. A.; Monzani, M. E.; Moretti, E.; Morselli, A.; Moskalenko, I. V.; Murgia, S.; Negro, M.; Nuss, E.; Ohsugi, T.; Omodei, N.; Orienti, M.; Orlando, E.; Ormes, J. F.; Paneque, D.; Perkins, J. S.; Pesce-Rollins, M.; Piron, F.; Pivato, G.; Porter, T. A.; Racusin, J. L.; Rainò, S.; Rando, R.; Razzaque, S.; Reimer, A.; Reimer, O.; Reposeur, T.; Ritz, S.; Rochester, L. S.; Romani, R. W.; Saz Parkinson, P. M.; Sgrò, C.; Simone, D.; Siskind, E. J.; Smith, D. A.; Spada, F.; Spandre, G.; Spinelli, P.; Suson, D. J.; Tajima, H.; Thayer, J. G.; Thayer, J. B.; Thompson, D. J.; Tibaldo, L.; Torres, D. F.; Troja, E.; Uchiyama, Y.; Venters, T. M.; Vianello, G.; Wood, K. S.; Wood, M.; Zaharijas, G.; Zhu, S.; Zimmer, S.

    2016-05-01

    The Fermi Large Area Telescope (LAT) has an instantaneous field of view (FoV) covering ∼ 1/5 of the sky and it completes a survey of the entire sky in high-energy gamma-rays every 3 hr. It enables searches for transient phenomena over timescales from milliseconds to years. Among these phenomena could be electromagnetic counterparts to gravitational wave (GW) sources. In this paper, we present a detailed study of the LAT observations relevant to Laser Interferometer Gravitational-wave Observatory (LIGO) event GW150914, which is the first direct detection of gravitational waves and has been interpreted as being due to the coalescence of two stellar-mass black holes. The localization region for GW150914 was outside the LAT FoV at the time of the GW signal. However, as part of routine survey observations, the LAT observed the entire LIGO localization region within ∼70 minutes of the trigger and thus enabled a comprehensive search for a γ-ray counterpart to GW150914. The study of the LAT data presented here did not find any potential counterparts to GW150914, but it did provide limits on the presence of a transient counterpart above 100 MeV on timescales of hours to days over the entire GW150914 localization region.

  17. The First Fermi-LAT Gamma-Ray Burst Catalog

    NASA Astrophysics Data System (ADS)

    Ackermann, M.; Ajello, M.; Asano, K.; Axelsson, M.; Baldini, L.; Ballet, J.; Barbiellini, G.; Bastieri, D.; Bechtol, K.; Bellazzini, R.; Bhat, P. N.; Bissaldi, E.; Bloom, E. D.; Bonamente, E.; Bonnell, J.; Bouvier, A.; Brandt, T. J.; Bregeon, J.; Brigida, M.; Bruel, P.; Buehler, R.; Burgess, J. Michael; Buson, S.; Byrne, D.; Caliandro, G. A.; Cameron, R. A.; Caraveo, P. A.; Cecchi, C.; Charles, E.; Chaves, R. C. G.; Chekhtman, A.; Chiang, J.; Chiaro, G.; Ciprini, S.; Claus, R.; Cohen-Tanugi, J.; Connaughton, V.; Conrad, J.; Cutini, S.; D'Ammando, F.; de Angelis, A.; de Palma, F.; Dermer, C. D.; Desiante, R.; Digel, S. W.; Dingus, B. L.; Di Venere, L.; Drell, P. S.; Drlica-Wagner, A.; Dubois, R.; Favuzzi, C.; Ferrara, E. C.; Fitzpatrick, G.; Foley, S.; Franckowiak, A.; Fukazawa, Y.; Fusco, P.; Gargano, F.; Gasparrini, D.; Gehrels, N.; Germani, S.; Giglietto, N.; Giommi, P.; Giordano, F.; Giroletti, M.; Glanzman, T.; Godfrey, G.; Goldstein, A.; Granot, J.; Grenier, I. A.; Grove, J. E.; Gruber, D.; Guiriec, S.; Hadasch, D.; Hanabata, Y.; Hayashida, M.; Horan, D.; Hou, X.; Hughes, R. E.; Inoue, Y.; Jackson, M. S.; Jogler, T.; Jóhannesson, G.; Johnson, A. S.; Johnson, W. N.; Kamae, T.; Kataoka, J.; Kawano, T.; Kippen, R. M.; Knödlseder, J.; Kocevski, D.; Kouveliotou, C.; Kuss, M.; Lande, J.; Larsson, S.; Latronico, L.; Lee, S.-H.; Longo, F.; Loparco, F.; Lovellette, M. N.; Lubrano, P.; Massaro, F.; Mayer, M.; Mazziotta, M. N.; McBreen, S.; McEnery, J. E.; McGlynn, S.; Michelson, P. F.; Mizuno, T.; Moiseev, A. A.; Monte, C.; Monzani, M. E.; Moretti, E.; Morselli, A.; Murgia, S.; Nemmen, R.; Nuss, E.; Nymark, T.; Ohno, M.; Ohsugi, T.; Omodei, N.; Orienti, M.; Orlando, E.; Paciesas, W. S.; Paneque, D.; Panetta, J. H.; Pelassa, V.; Perkins, J. S.; Pesce-Rollins, M.; Piron, F.; Pivato, G.; Porter, T. A.; Preece, R.; Racusin, J. L.; Rainò, S.; Rando, R.; Rau, A.; Razzano, M.; Razzaque, S.; Reimer, A.; Reimer, O.; Reposeur, T.; Ritz, S.; Romoli, C.; Roth, M.; Ryde, F.; Saz Parkinson, P. M.; Schalk, T. L.; Sgrò, C.; Siskind, E. J.; Sonbas, E.; Spandre, G.; Spinelli, P.; Suson, D. J.; Tajima, H.; Takahashi, H.; Takeuchi, Y.; Tanaka, Y.; Thayer, J. G.; Thayer, J. B.; Thompson, D. J.; Tibaldo, L.; Tierney, D.; Tinivella, M.; Torres, D. F.; Tosti, G.; Troja, E.; Tronconi, V.; Usher, T. L.; Vandenbroucke, J.; van der Horst, A. J.; Vasileiou, V.; Vianello, G.; Vitale, V.; von Kienlin, A.; Winer, B. L.; Wood, K. S.; Wood, M.; Xiong, S.; Yang, Z.

    2013-11-01

    In three years of observations since the beginning of nominal science operations in 2008 August, the Large Area Telescope (LAT) on board the Fermi Gamma-Ray Space Telescope has observed high-energy (gsim 20 MeV) γ-ray emission from 35 gamma-ray bursts (GRBs). Among these, 28 GRBs have been detected above 100 MeV and 7 GRBs above ~20 MeV. The first Fermi-LAT catalog of GRBs is a compilation of these detections and provides a systematic study of high-energy emission from GRBs for the first time. To generate the catalog, we examined 733 GRBs detected by the Gamma-Ray Burst Monitor (GBM) on Fermi and processed each of them using the same analysis sequence. Details of the methodology followed by the LAT collaboration for the GRB analysis are provided. We summarize the temporal and spectral properties of the LAT-detected GRBs. We also discuss characteristics of LAT-detected emission such as its delayed onset and longer duration compared with emission detected by the GBM, its power-law temporal decay at late times, and the fact that it is dominated by a power-law spectral component that appears in addition to the usual Band model.

  18. Serotyping scheme for Campylobacter jejuni and Campylobacter coli based on direct agglutination of heat-stable antigens.

    PubMed

    Frost, J A; Oza, A N; Thwaites, R T; Rowe, B

    1998-02-01

    Campylobacter is now the most frequently reported cause of gastrointestinal disease in England and Wales, yet few isolates are characterized beyond the genus level. The majority of isolates are Campylobacter jejuni (90%), with most of the remainder being Campylobacter coli. We describe an adaptation of the Penner serotyping scheme in which passive hemagglutination has been replaced by detection of heat-stable antigens by direct bacterial agglutination; absorbed antisera are used where appropriate. This scheme has been used to type 2,407 C. jejuni samples and 182 C. coli samples isolated in Wales between April 1996 and March 1997. Forty-seven C. jejuni serotypes were identified, with the 10 most prevalent serotypes accounting for 53% of the isolates tested; 19% of the isolates were untypeable. Only fifteen C. coli serotypes were identified, with three serotypes accounting for 69% of the isolates. This scheme provides a baseline for epidemiological studies of C. jejuni and C. coli.

  19. Lats1 suppresses centrosome overduplication by modulating the stability of Cdc25B

    PubMed Central

    Mukai, Satomi; Yabuta, Norikazu; Yoshida, Kaori; Okamoto, Ayumi; Miura, Daisaku; Furuta, Yasuhide; Abe, Takaya; Nojima, Hiroshi

    2015-01-01

    Numerical aberration of the centrosome results in chromosome missegregation, eventually leading to chromosomal instability, a hallmark of human tumor malignancy. Large tumor suppressors 1 and 2 (Lats1 and Lats2) are central kinases in the Hippo pathway and regulate development and tumorigenesis by coordinating the balance between cell proliferation and apoptosis. Importantly, Lats1 and Lats2 also play pivotal roles in cell cycle checkpoint and mitosis. The Lats proteins localize at centrosomes, but their centrosomal functions remain elusive. Here, we generated Lats1-null knockout (Lats1−/−) mice and established Lats1-null mouse embryonic fibroblasts (MEFs). In Lats1−/− MEFs, centrosomes were markedly overduplicated, leading to severe mitotic defects such as chromosome missegregation and cytokinesis failure. We also found that Lats1 physically interacts with Cdc25B phosphatase that localizes both at the centrosome and in the nucleus and regulates the linkage between the centrosome cycle and mitotic progression. Although Lats1 did not phosphorylate Cdc25B, loss of Lats1 in MEFs caused abnormal accumulation of Cdc25B protein and hyperactivation of Cdk2 toward nucleophosmin (NPM/B23), one of the licensing factors involved in centriole duplication. Taken together, these data suggest that Lats1 regulates Cdc25B protein level and subsequent Cdk2 activity, thereby suppressing centrosome overduplication during interphase. PMID:26530630

  20. Agglutinating monoclonal antibodies that specifically recognize lipooligosaccharide A of Bordetella pertussis.

    PubMed Central

    Li, Z M; Cowell, J L; Brennan, M J; Burns, D L; Manclark, C R

    1988-01-01

    Monoclonal antibodies that specifically agglutinate strains of Bordetella pertussis having serotype 1 agglutinogen were uniquely reactive with the electrophoretically slow-migrating A form of lipooligosaccharide. These monoclonal antibodies should be useful for the structural analysis of B. pertussis lipooligosaccharide and for the establishment of a better-defined serogroup for Bordetella species. Images PMID:2893776

  1. Agglutinating monoclonal antibodies that specifically recognize lipooligosaccharide A of Bordetella pertussis.

    PubMed

    Li, Z M; Cowell, J L; Brennan, M J; Burns, D L; Manclark, C R

    1988-03-01

    Monoclonal antibodies that specifically agglutinate strains of Bordetella pertussis having serotype 1 agglutinogen were uniquely reactive with the electrophoretically slow-migrating A form of lipooligosaccharide. These monoclonal antibodies should be useful for the structural analysis of B. pertussis lipooligosaccharide and for the establishment of a better-defined serogroup for Bordetella species. PMID:2893776

  2. The incomplete anti-Rh antibody agglutination mechanism of trypsinized ORh+ red cells.

    PubMed Central

    Margni, R A; Leoni, J; Bazzurro, M

    1977-01-01

    The capacity for binding to trypsinized and non-trypsinized ORh+ red cells, of the IgG incomplete anti-Rh antibody and its F(ab')2 and Fc fragments has been investigated. An analysis has also been made of the capacity of non-specific human IgG, aggregated non-specific human IgG, human IgM (19S) and IgM (7S), and of fragments Fcgamma, Fcmu and Fc5mu to inhibit the agglutination of trypsinized ORh+ red cells by the IgG incomplete anti-Rh antibody. The results obtained indicate that these antibodies behave in a similar manner to that of nonprecipitating antibodies, and that the agglutination of trypsinized red cells seems to be a mixed reaction due to the interaction of an Fab fragment with its Rh antigenic determinant present in the surface of a red cell and the Fc of the same molecule with a receptor for Fc present in adjacent red cells. The trypsin treatment apparently results in the liberation of occult Fc receptors. It has also been demonstrated that in the agglutination of ORh+ red cells by IgG incomplete anti-Rh antibody in the presence of albumin, interaction must occur in some manner between the albumin and the Fc fragment since the F(ab')2 fragment does not give rise to agglutination under such conditions. Images Figure 1 PMID:415968

  3. An integrated fiberoptic-microfluidic device for agglutination detection and blood typing.

    PubMed

    Ramasubramanian, Melur K; Alexander, Stewart P

    2009-02-01

    In this paper, an integrated fiberoptic-microfluidic device for the detection of agglutination for blood type cross-matching has been described. The device consists of a straight microfluidic channel through with a reacted RBC suspension is pumped with the help of a syringe pump. The flow intersects an optical path created by an emitter-received fiber optic pair integrated into the microfluidic device. A 650 nm laser diode is used as the light source and a silicon photodiode is used to detect the light intensity. The spacing between the tips of the two optic fibers can be adjusted. When fiber spacing is large and the concentration of the suspension is high, scattering phenomenon becomes the dominant mechanism for agglutination detection while at low concentrations and small spacing, optointerruption becomes the dominant mechanism. An agglutination strength factor (ASF) is calculated from the data. Studies with a variety of blood types indicate that the sensing method correctly identifies the agglutination reaction in all cases. A disposable integrated device can be designed for future implementation of the method for near-bedside pre-transfusion check. PMID:18815884

  4. Capsular gene typing of Streptococcus agalactiae compared to serotyping by latex agglutination.

    PubMed

    Yao, Kaihu; Poulsen, Knud; Maione, Domenico; Rinaudo, C Daniela; Baldassarri, Lucilla; Telford, John L; Sørensen, Uffe B Skov; Kilian, Mogens

    2013-02-01

    We evaluated three different PCR-based capsular gene typing methods applied to 312 human and bovine Streptococcus agalactiae (group B Streptococcus [GBS]) isolates and compared the results to serotyping results obtained by latex agglutination. Among 281 human isolates 27% could not be typed by latex agglutination. All 312 isolates except 5 could be typed by the three PCR methods combined. Two of these methods were multiplex assays. Among the isolates that were typeable by both latex agglutination and capsular gene typing, 94% showed agreement between the two methods. However, each of the PCR methods showed limitations. One of the methods did not include all 10 recognized serotypes, one misidentified eight isolates of serotypes Ib and IV as serotype Ia, and one did not distinguish between serotypes VII and IX. For five isolates that showed aberrant patterns in the capsular gene typing, long-range PCR targeting the cps operon disclosed large insertions or deletions affecting the cps gene cluster. A sensitive flow cytometric assay based on serotype-specific antibodies applied to 76 selected isolates that were nontypeable by latex agglutination revealed that approximately one-half of these did express capsular polysaccharide. A procedure for convenient and reliable capsular gene typing to be included in epidemiological and surveillance studies of S. agalactiae is proposed. PMID:23196363

  5. A Southern Sky Survey with Fermi LAT and ASKAP

    SciTech Connect

    Cameron, Robert A.; /SLAC /KIPAC, Menlo Park

    2010-04-29

    We present the prospects for a future joint gamma-ray and radio survey of southern hemisphere sources using the Fermi Large Area Telescope (LAT) and the upcoming Australian Square Kilometre Array Pathfinder (ASKAP) radio telescope. ASKAP is a next generation radio telescope designed to perform surveys at GHz frequencies at a much higher survey speed than previous radio telescopes, and is scheduled to start engineering observations in 2011. The survey capabilities of both Fermi LAT and ASKAP are described, and the planned science surveys for ASKAP are summarized. We give some expected details of the Variable and Slow Transient (VAST) survey using ASKAP, which will search for transients on timescales from 5 seconds to years. Some observational properties of faint and transient sources seen at gamma-ray and radio wavelengths are summarized, and prospects and strategies for using ASKAP survey data for LAT source counterpart identification are summarized.

  6. Exfoliative toxin detection using reversed passive latex agglutination: clinical and epidemiologic applications.

    PubMed Central

    Kawabata, A; Ichiyama, S; Iinuma, Y; Hasegawa, Y; Ohta, M; Shimokata, K

    1997-01-01

    A rapid and simple method for detecting exfoliative toxin serotypes A and B from clinical isolates has been developed as a test kit (EXT-RPLA; Denka Seiken Co. Ltd., Niigata, Japan). This method is based on reversed passive latex agglutination. The detection limit of the EXT-RPLA observed for purified exfoliative toxin serotypes A and B was 1 ng/ml. We evaluated the clinical and epidemiologic uses of the EXT-RPLA. A total of 381 isolates of Staphylococcus aureus, 292 from various clinical specimens and 89 from the skin of dermatologic patients, were studied. The EXT-RPLA detected 19 exfoliative toxin producers, including 16 serotype A producers and 3 serotype B producers, but no double producers. The sensitivity and specificity of the EXT-RPLA were confirmed by the newborn mouse bioassay and a PCR assay for the structural genes for exfoliative toxin serotypes A and B (eta and etb, respectively). The overall positivity rate of exfoliative toxin producers was 5.0% (19 of 381), including 16 serotype A isolates and 3 serotype B isolates. Of the 89 isolates from the skin of dermatologic patients, 12 (13.5%) were positive for exfoliative toxin production. Only 2 (1.3%) of the 153 methicillin-resistant S. aureus isolates produced exfoliative toxin, while 17 (7.5%) of the 228 methicillin-sensitive isolates produced exfoliative toxin. The EXT-RPLA assay is a simple and reliable method for detecting exfoliative toxin, and we recommend its use for the rapid diagnosis of staphylococcal scalded skin syndrome. We also recommend its use for detection of this syndrome so that effective control measures can be taken against the spread of this syndrome. PMID:9230367

  7. Interactions with lectins and agglutination profiles of clinical, food, and environmental isolates of Listeria.

    PubMed Central

    Facinelli, B; Giovanetti, E; Casolari, C; Varaldo, P E

    1994-01-01

    On the basis of preliminary trials with 14 collection strains of Listeria, five lectins (Canavalia ensiformis, concanavalin A; Griffonia simplicifolia lectin I; Helix pomatia agglutinin; Ricinus communis agglutinin; and Triticum vulgaris wheat germ agglutinin) were selected to set up a microtiter agglutination assay. The lectin agglutination profiles of 174 clinical, food, and environmental strains of Listeria monocytogenes, Listeria innocua, and Listeria seeligeri were investigated. Data on the standard determination of the antigenic structure were available for clinical strains; nonclinical isolates were assigned to serogroup 1 or 4 with commercial antisera. The listeria-lectin interaction was related to serological type rather than species; in particular, the strains assigned to serogroup 1 or belonging to serovars 1/2a, 1/2b, 1/2c, 3a, 3b, and 7 were never agglutinated by G. simplicifolia lectin I. The five-lectin set proved to be capable of detecting differences between serologically identical isolates of L. monocytogenes. Of the 150 isolates of this species, 144 were distributed over 15 different lectin agglutination profiles and 6 autoagglutinated, the overall typeability being 96%. However, the profiles encountered among L. monocytogenes isolates were not randomly distributed. With strains assigned to serogroup 1 or belonging to serovars 1/2a, 1/2b, 1/2c, and 3b, the clinical isolates fell into only two of the eight patterns recorded overall; with strains of serogroup 4 and serovar 4b, food and environmental isolates were distributed over eight of the nine patterns found in total, while clinical isolates were distributed over five patterns. In a comparative study of 15 epidemiologically relevant isolates of L. monocytogenes from five distinct outbreaks, strains with identical phage types and/or DNA fingerprints displayed identical lectin profiles. The heterogeneity of agglutination profiles may form the basis of a new approach to L. monocytogenes typing

  8. The production of nominal and verbal inflection in an agglutinative language: evidence from Hungarian.

    PubMed

    Nemeth, Dezso; Janacsek, Karolina; Turi, Zsolt; Lukacs, Agnes; Peckham, Don; Szanka, Szilvia; Gazso, Dorottya; Lovassy, Noemi; Ullman, Michael T

    2015-01-01

    The contrast between regular and irregular inflectional morphology has been useful in investigating the functional and neural architecture of language. However, most studies have examined the regular/irregular distinction in non-agglutinative Indo-European languages (primarily English) with relatively simple morphology. Additionally, the majority of research has focused on verbal rather than nominal inflectional morphology. The present study attempts to address these gaps by introducing both plural and past tense production tasks in Hungarian, an agglutinative non-Indo-European language with complex morphology. Here we report results on these tasks from healthy Hungarian native-speaking adults, in whom we examine regular and irregular nominal and verbal inflection in a within-subjects design. Regular and irregular nouns and verbs were stem on frequency, word length, and phonological structure, and both accuracy and response times were acquired. The results revealed that the regular/irregular contrast yields similar patterns in Hungarian, for both nominal and verbal inflection, as in previous studies of non-agglutinative Indo-European languages: the production of irregular inflected forms was both less accurate and slower than of regular forms, both for plural and past-tense inflection. The results replicate and extend previous findings to an agglutinative language with complex morphology. Together with previous studies, the evidence suggests that the regular/irregular distinction yields a basic behavioral pattern that holds across language families and linguistic typologies. Finally, the study sets the stage for further research examining the neurocognitive substrates of regular and irregular morphology in an agglutinative non-Indo-European language.

  9. The production of nominal and verbal inflection in an agglutinative language: evidence from Hungarian.

    PubMed

    Nemeth, Dezso; Janacsek, Karolina; Turi, Zsolt; Lukacs, Agnes; Peckham, Don; Szanka, Szilvia; Gazso, Dorottya; Lovassy, Noemi; Ullman, Michael T

    2015-01-01

    The contrast between regular and irregular inflectional morphology has been useful in investigating the functional and neural architecture of language. However, most studies have examined the regular/irregular distinction in non-agglutinative Indo-European languages (primarily English) with relatively simple morphology. Additionally, the majority of research has focused on verbal rather than nominal inflectional morphology. The present study attempts to address these gaps by introducing both plural and past tense production tasks in Hungarian, an agglutinative non-Indo-European language with complex morphology. Here we report results on these tasks from healthy Hungarian native-speaking adults, in whom we examine regular and irregular nominal and verbal inflection in a within-subjects design. Regular and irregular nouns and verbs were stem on frequency, word length, and phonological structure, and both accuracy and response times were acquired. The results revealed that the regular/irregular contrast yields similar patterns in Hungarian, for both nominal and verbal inflection, as in previous studies of non-agglutinative Indo-European languages: the production of irregular inflected forms was both less accurate and slower than of regular forms, both for plural and past-tense inflection. The results replicate and extend previous findings to an agglutinative language with complex morphology. Together with previous studies, the evidence suggests that the regular/irregular distinction yields a basic behavioral pattern that holds across language families and linguistic typologies. Finally, the study sets the stage for further research examining the neurocognitive substrates of regular and irregular morphology in an agglutinative non-Indo-European language. PMID:25769039

  10. A critical role for the regulation of Syk from agglutination to aggregation in human platelets.

    PubMed

    Shih, Chun-Ho; Chiang, Tin-Bin; Wang, Wen-Jeng

    2014-01-10

    Agglucetin, a tetrameric glycoprotein (GP) Ibα agonist from Formosan Agkistrodon acutus venom, has been characterized as an agglutination inducer in human washed platelets (WPs). In platelet-rich plasma (PRP), agglucetin dramatically elicits a biphasic response of agglutination and subsequent aggregation. For clarifying the intracellular signaling events from agglutination to aggregation in human platelets, we examined the essential signaling molecules involved through the detection of protein tyrosine phosphorylation (PTP). In WPs, an anti-GPIbα monoclonal antibody (mAb) AP1, but not a Src kinase inhibitor PP1, completely inhibited agglucetin-induced agglutination. However, PP1 but not AP1 had a potent suppression on platelet aggregation by a GPVI activator convulxin. The PTP analyses showed agglucetin alone can cause a weak pattern involving sequential phosphorylation of Lyn/Fyn, Syk, SLP-76 and phospholipase Cγ2 (PLCγ2). Furthermore, a Syk-selective kinase inhibitor, piceatannol, significantly suppressed the aggregating response in agglucetin-activated PRP. Analyzed by flow cytometry, the binding capacity of fluorophore-conjugated PAC-1, a mAb recognizing activated integrin αIIbβ3, was shown to increase in agglucetin-stimulated platelets. Again, piceatannol but not PP1 had a concentration-dependent suppression on agglucetin-induced αIIbβ3 exposure. Moreover, the formation of signalosome, including Syk, SLP-76, VAV, adhesion and degranulation promoting adapter protein (ADAP) and PLCγ2, are required for platelet aggregation in agglucetin/fibrinogen-activated platelets. In addition, GPIbα-ligation via agglucetin can substantially promote the interactions between αIIbβ3 and fibrinogen. Therefore, the signal pathway of Lyn/Fyn/Syk/SLP-76/ADAP/VAV/PLCγ2/PKC is sufficient to trigger platelet aggregation in agglucetin/fibrinogen-pretreated platelets. Importantly, Syk may function as a major regulator for the response from GPIbα-initiated agglutination to

  11. A critical role for the regulation of Syk from agglutination to aggregation in human platelets.

    PubMed

    Shih, Chun-Ho; Chiang, Tin-Bin; Wang, Wen-Jeng

    2014-01-10

    Agglucetin, a tetrameric glycoprotein (GP) Ibα agonist from Formosan Agkistrodon acutus venom, has been characterized as an agglutination inducer in human washed platelets (WPs). In platelet-rich plasma (PRP), agglucetin dramatically elicits a biphasic response of agglutination and subsequent aggregation. For clarifying the intracellular signaling events from agglutination to aggregation in human platelets, we examined the essential signaling molecules involved through the detection of protein tyrosine phosphorylation (PTP). In WPs, an anti-GPIbα monoclonal antibody (mAb) AP1, but not a Src kinase inhibitor PP1, completely inhibited agglucetin-induced agglutination. However, PP1 but not AP1 had a potent suppression on platelet aggregation by a GPVI activator convulxin. The PTP analyses showed agglucetin alone can cause a weak pattern involving sequential phosphorylation of Lyn/Fyn, Syk, SLP-76 and phospholipase Cγ2 (PLCγ2). Furthermore, a Syk-selective kinase inhibitor, piceatannol, significantly suppressed the aggregating response in agglucetin-activated PRP. Analyzed by flow cytometry, the binding capacity of fluorophore-conjugated PAC-1, a mAb recognizing activated integrin αIIbβ3, was shown to increase in agglucetin-stimulated platelets. Again, piceatannol but not PP1 had a concentration-dependent suppression on agglucetin-induced αIIbβ3 exposure. Moreover, the formation of signalosome, including Syk, SLP-76, VAV, adhesion and degranulation promoting adapter protein (ADAP) and PLCγ2, are required for platelet aggregation in agglucetin/fibrinogen-activated platelets. In addition, GPIbα-ligation via agglucetin can substantially promote the interactions between αIIbβ3 and fibrinogen. Therefore, the signal pathway of Lyn/Fyn/Syk/SLP-76/ADAP/VAV/PLCγ2/PKC is sufficient to trigger platelet aggregation in agglucetin/fibrinogen-pretreated platelets. Importantly, Syk may function as a major regulator for the response from GPIbα-initiated agglutination to

  12. The Production of Nominal and Verbal Inflection in an Agglutinative Language: Evidence from Hungarian

    PubMed Central

    Peckham, Don; Szanka, Szilvia; Gazso, Dorottya; Lovassy, Noemi; Ullman, Michael T.

    2015-01-01

    The contrast between regular and irregular inflectional morphology has been useful in investigating the functional and neural architecture of language. However, most studies have examined the regular/irregular distinction in non-agglutinative Indo-European languages (primarily English) with relatively simple morphology. Additionally, the majority of research has focused on verbal rather than nominal inflectional morphology. The present study attempts to address these gaps by introducing both plural and past tense production tasks in Hungarian, an agglutinative non-Indo-European language with complex morphology. Here we report results on these tasks from healthy Hungarian native-speaking adults, in whom we examine regular and irregular nominal and verbal inflection in a within-subjects design. Regular and irregular nouns and verbs were stem on frequency, word length, and phonological structure, and both accuracy and response times were acquired. The results revealed that the regular/irregular contrast yields similar patterns in Hungarian, for both nominal and verbal inflection, as in previous studies of non-agglutinative Indo-European languages: the production of irregular inflected forms was both less accurate and slower than of regular forms, both for plural and past-tense inflection. The results replicate and extend previous findings to an agglutinative language with complex morphology. Together with previous studies, the evidence suggests that the regular/irregular distinction yields a basic behavioral pattern that holds across language families and linguistic typologies. Finally, the study sets the stage for further research examining the neurocognitive substrates of regular and irregular morphology in an agglutinative non-Indo-European language. PMID:25769039

  13. Antileukocyte antibody in postpartum and renal transplant subjects. A comparison of capillary agglutination and lymphocytotoxicity reactions.

    PubMed

    Thompson, J S; Jackson, D; Greazel, N A; Parmely, M J; Severson, C D

    1976-02-01

    Sera were obtained from 48 gravida II prenatal and 211 multiparous nonpregnant females and examined for leukocyte antibodies comparing a standard lymphocytotoxicity (CY) test with capillary agglutination (CA). Antibody was detected in 41% of the samples in both groups but only CA tests were positive with approximately one-half of the prenatal and three-fourths of the multiparous specimens. Although, CA reactions, when accompanied by positive CY responses, usually correlated with HLA, no correlation with HLA, 5b, or the neutrophil antigens was determined for 35 of the 48 sera reacting only by CA. As a model to test the specificity of CA positive-CY negative antisera, four extensively studied sera were further analyzed in 16 families. Independent segregation from the HLA complex and ABO and Rh antigens was confirmed and two of the sera appeared to detect separate clusters of reactions in conjunction with some of the other reagents. Pre- and postgraft samples obtained from 23 living related and 75 cadaveric renal transplanted patients were investigated and compared for graft function and prospective tissue typing. Although direct crossmatches were negative prior to surgery, 17.9% of the pretransplant samples from living related and 28.0% from cadaveric recipients contained detectable antibody when tested against a cell panel. Similar to the prenatal and multiparous groups, the majority of these responses were detected by CA. Following engraftment, antibody first became evident in 11 of 19 (58%) living related and in 23 of 53 (48.2%) cadaveric hosts. There was a striking association between the development of CA and CY antibody and failure, as contrasted to 100% 9-month or greater survival in 10 of 10 living related and 15 of 15 cadaveric transplants in whom only CA antibodies arose postoperatively. In total, these studies indicate that CA reacts with HLA antigens in common with CY tests. In addition, CA may detect HLA when CY is negative but many other reactions

  14. Why do intimate partners live apart? Evidence on LAT relationships across Europe

    PubMed Central

    Liefbroer, Aart C.; Poortman, Anne-Rigt; Seltzer, Judith A.

    2015-01-01

    BACKGROUND Most research asks whether or not cohabitation has come to rival marriage. Little is known about the meaning of living apart together (LAT) relationships, and whether LAT is an alternative to marriage and cohabitation or a dating relationship. OBJECTIVE We examine across Europe: (1) the prevalence of LAT, (2) the reasons for LAT, and (3) the correlates of (a) LAT relationships vis-à-vis being single, married, or cohabiting, and (b) different types of LAT union. METHODS Using Generations and Gender Survey data from ten Western and Eastern European countries, we present descriptive statistics about LATs and estimate multinominal logistic regression models to assess the correlates of being in different types of LAT unions. RESULTS LAT relationships are uncommon, but they are more common in Western than Eastern Europe. Most people in LAT unions intend to live together but are apart for practical reasons. LAT is more common among young people, those enrolled in higher education, people with liberal attitudes, highly educated people, and those who have previously cohabited or been married. Older people and divorced or widowed persons are more likely to choose LAT to maintain independence. Surprisingly, attitudinal and educational differences are more pronounced in Eastern Europe than in Western Europe. CONCLUSIONS A tentative conclusion is that LAT is more often a stage in the union formation process than an alternative to marriage and cohabitation. Yet some groups do view LAT as substituting for marriage and cohabitation, and these groups differ between East and West. In Eastern Europe a cultural, highly educated elite seems to be the first to resist traditional marriage norms and embrace LAT (and cohabitation) as alternative living arrangements, whereas this is less the case in Western Europe. In Western Europe, LAT unions are mainly an alternative for persons who have been married before or had children in a prior relationship. PMID:26085812

  15. Activated PLC-γ1 is catalytically induced at LAT but activated PLC-γ1 is localized at both LAT- and TCR-containing complexes.

    PubMed

    Cruz-Orcutt, Noemi; Vacaflores, Aldo; Connolly, Sean F; Bunnell, Stephen C; Houtman, Jon C D

    2014-04-01

    Phospholipase C-γ1 (PLC-γ1) is a key regulator of T cell receptor (TCR)-induced signaling. Activation of the TCR enhances PLC-γ1 enzymatic function, resulting in calcium influx and the activation of PKC family members and RasGRP. The current model is that phosphorylation of LAT tyrosine 132 facilitates the recruitment of PLC-γ1, leading to its activation and function at the LAT complex. In this study, we examined the phosphorylation kinetics of LAT and PLC-γ1 and the cellular localization of activated PLC-γ1. We observed that commencement of the phosphorylation of LAT tyrosine 132 and PLC-γ1 tyrosine 783 occurred simultaneously, supporting the current model. However, once begun, PLC-γ1 activation occurred more rapidly than LAT tyrosine 132. The association of LAT and PLC-γ1 was more transient than the interaction of LAT and Grb2 and a pool of activated PLC-γ1 translocated away from LAT to cellular structures containing the TCR. These studies demonstrate that LAT and PLC-γ1 form transient interactions that catalyze the activation of PLC-γ1, but that activated PLC-γ1 resides in both LAT and TCR clusters. Together, this work highlights that our current model is incomplete and the activation and function of PLC-γ1 in T cells is highly complex.

  16. Studying Gamma-Ray Blazars With the GLAST-LAT

    SciTech Connect

    Lott, B.; Carson, J.; Madejski, G.; Ciprini, S.; Dermer, C.D.; Giommi, P.; Lonjou, V.; Reimer, A.; /Stanford U., HEPL /KIPAC, Menlo Park

    2007-11-13

    Thanks to its sensitivity (4 10{sup -9} ph (E> 100 MeV) cm{sup -2} s{sup -1} for one year of observation), the GLAST LAT should detect many more (over a thousand) gamma-ray blazars than currently known. This large blazar sample will enable detailed population studies to be carried out. Moreover, the LAT large field-of-view combined with the scanning mode will provide a very uniform exposure over the sky, allowing a constant monitoring of several tens of blazars and flare alerts to be issued. This poster presents the LAT performance relevant to blazar studies, more particularly related to timing and spectral properties. Major specific issues regarding the blazar phenomenon that the LAT data should shed light on thanks to these capabilities will be discussed, as well as the different approaches foreseen to address them. The associated data required in other bands, to be collected in contemporaneous/simultaneous multiwavelength campaigns are mentioned as well.

  17. Comparison of a dot immunobinding assay, latex agglutination, and cytotoxin assay for laboratory diagnosis of Clostridium difficile-associated diarrhea.

    PubMed

    Woods, G L; Iwen, P C

    1990-05-01

    C. diff-CUBE, a dot immunobinding assay (DIA) (Difco Laboratories, Ann Arbor, Mich.) for detection of Clostridium difficile toxin A in stool specimens, was compared with latex agglutination (LA) (Marion Laboratories, Kansas City, Mo.) and cytotoxin assay (CTA) for the laboratory diagnosis of C. difficile-associated diarrhea. A total of 200 stool specimens collected from 169 patients with suspected C. difficile diarrhea were tested. Of the 198 specimens evaluated by all three methods, 36 (18%) from 36 patients were positive by one or more of the tests. Twenty-five, 26, and 23 specimens were positive by CTA, DIA, and LA, respectively; 14 were positive by all three methods. Eight specimens yielded nonspecific LA test results; all eight were negative by CTA, and one was positive by DIA. DIA results agreed with CTA results in 183 (92%) cases and with LA results in 175 (88%) cases. CTA and LA results agreed in 179 (90%) cases. Freezing of the specimen did not appear to adversely affect either the DIA or LA test. These preliminary results suggest that C. diff-CUBE may be useful as a rapid screen for the diagnosis of C. difficile-associated diarrhea. However, for optimum laboratory diagnosis, further testing of all stools that are negative by DIA is warranted.

  18. Comparison of immunofluorescence, particle agglutination, and enzyme immunoassays for detection of human T-cell leukemia virus type I antibody in African sera.

    PubMed

    Verdier, M; Denis, F; Leonard, G; Sangare, A; Patillaud, S; Prince-David, M; Essex, M

    1990-09-01

    The effectiveness of four screening tests for detecting antibody to human T-cell leukemia virus type I (HTLV-I) was determined by using 2,700 African serum specimens. The tests studied were indirect immunofluorescence, particle agglutination from Fujirebio, and two enzyme immunoassays, one from Abbott Laboratories that used virus lysate from HUT 102 cells and the other from Cambridge BioScience Corp. that used an env recombinant protein. Positive and doubtful sera were confirmed by Western immunoblot and radioimmunoprecipitation assay with Food and Drug Administration seropositivity criteria. The best results were obtained with the two enzyme immunoassays, which were more sensitive (100 and 98.6% [Abbott and Cambridge, respectively]) and more specific (98.7 and 96.5%). Indirect immunofluorescence exhibited difficulties for reading and interpretation. With particle agglutination, prozone was observed for 9 of 78 HTLV-I-positive serum specimens. False-positives in any of the tests were not linked to cross-reactions with human immunodeficiency viruses. However, confirmation tests remain necessary for HTLV-I screening.

  19. LATS1/WARTS phosphorylates MYPT1 to counteract PLK1 and regulate mammalian mitotic progression

    PubMed Central

    Chiyoda, Tatsuyuki; Sugiyama, Naoyuki; Shimizu, Takatsune; Naoe, Hideaki; Kobayashi, Yusuke; Ishizawa, Jo; Arima, Yoshimi; Tsuda, Hiroshi; Ito, Masaaki; Kaibuchi, Kozo; Aoki, Daisuke; Ishihama, Yasushi

    2012-01-01

    In the mitotic exit network of budding yeast, Dbf2 kinase phosphorylates and regulates Cdc14 phosphatase. In contrast, no phosphatase substrates of LATS1/WARTS kinase, the mammalian equivalent of Dbf2, has been reported. To address this discrepancy, we performed phosphoproteomic screening using LATS1 kinase. Screening identified MYPT1 (myosin phosphatase–targeting subunit 1) as a new substrate for LATS1. LATS1 directly and preferentially phosphorylated serine 445 (S445) of MYPT1. An MYPT1 mutant (S445A) failed to dephosphorylate Thr 210 of PLK1 (pololike kinase 1), thereby activating PLK1. This suggests that LATS1 promotes MYPT1 to antagonize PLK1 activity. Consistent with this, LATS1-depleted HeLa cells or fibroblasts from LATS1 knockout mice showed increased PLK1 activity. We also found deoxyribonucleic acid (DNA) damage–induced LATS1 activation caused PLK1 suppression via the phosphorylation of MYPT1 S445. Furthermore, LATS1 knockdown cells showed reduced G2 checkpoint arrest after DNA damage. These results indicate that LATS1 phosphorylates a phosphatase as does the yeast Dbf2 and demonstrate a novel role of LATS1 in controlling PLK1 at the G2 DNA damage checkpoint. PMID:22641346

  20. A STACKED ANALYSIS OF 115 PULSARS OBSERVED BY THE FERMI LAT

    SciTech Connect

    McCann, A.

    2015-05-10

    Due to the low gamma-ray fluxes from pulsars above 50 GeV and the small collecting area of space-based telescopes, the gamma-ray emission discovered by the Fermi Large Area Telescope (LAT) in ∼150 pulsars is largely unexplored at these energies. In this regime, the uncertainties on the spectral data points and/or the constraints from upper limits are not sufficient to provide robust tests of competing emission models in individual pulsars. The discovery of power-law-type emission from the Crab pulsar at energies exceeding 100 GeV provides a compelling justification for exploration of other pulsars at these energies. We applied the method of aperture photometry to measure pulsar emission spectra from Fermi-LAT data and present a stacked analysis of 115 pulsars selected from the Second Fermi-LAT catalog of gamma-ray pulsars. This analysis, which uses an average of ∼4.2 yr of data per pulsar, aggregates low-level emission which cannot be resolved in individual objects but can be detected in an ensemble. We find no significant stacked excess at energies above 50 GeV. An upper limit of 30% of the Crab pulsar level is found for the average flux from 115 pulsars in the 100–177 GeV energy range at the 95% confidence level. Stacked searches exclusive to the young pulsar sample, the millisecond pulsar sample, and several other promising sub-samples also return no significant excesses above 50 GeV.

  1. Comparison of type 2 and type 6 fimbriae of Bordetella pertussis by using agglutinating monoclonal antibodies.

    PubMed Central

    Li, Z M; Brennan, M J; David, J L; Carter, P H; Cowell, J L; Manclark, C R

    1988-01-01

    Two types of fimbriae have been identified on the pathogenic gram-negative organism Bordetella pertussis. Monoclonal antibodies to these fimbriae were produced to better understand the role of fimbriae as serotype-specific agglutinogens and to investigate the antigenic relationship between these fimbriae. Three monoclonal antibodies were identified that specifically agglutinated B. pertussis cells containing the U.S. Reference Factor 2 agglutinogen, and six monoclonal antibodies were produced that agglutinated only those strains containing the U.S. Reference Factor 6 agglutinogen. Indirect immunofluorescence studies and immunogold electron microscopy demonstrated that these monoclonal antibodies bind to an outer membrane component on serotype-specific strains of B. pertussis. All of the monoclonal antibodies reacted with native or partially assembled type-specific fimbriae but not with monomeric fimbrial subunits as indicated by Western blot (immunoblot) analysis. The fimbrial agglutinogens recognized by the monoclonal antibodies were also uniquely reactive with either U.S. Reference Factor 2 or 6 antiserum (Eldering agglutinogen 2 or 6 polyclonal antiserum) in an indirect ELISA. No cross-reactivity of the monoclonal antibodies with the unrelated fimbriae was observed in any of the comparative immunological studies. Some of the monoclonal antibodies agglutinated certain strains of B. bronchiseptica, suggesting that this closely related species can contain antigenically similar fimbriae. These monoclonal antibodies should prove useful for further structural and functional analysis of Bordetella fimbriae and for studies on the role that these antigens play in prevention of infection and disease. Images PMID:2903125

  2. Comparison of type 2 and type 6 fimbriae of Bordetella pertussis by using agglutinating monoclonal antibodies.

    PubMed

    Li, Z M; Brennan, M J; David, J L; Carter, P H; Cowell, J L; Manclark, C R

    1988-12-01

    Two types of fimbriae have been identified on the pathogenic gram-negative organism Bordetella pertussis. Monoclonal antibodies to these fimbriae were produced to better understand the role of fimbriae as serotype-specific agglutinogens and to investigate the antigenic relationship between these fimbriae. Three monoclonal antibodies were identified that specifically agglutinated B. pertussis cells containing the U.S. Reference Factor 2 agglutinogen, and six monoclonal antibodies were produced that agglutinated only those strains containing the U.S. Reference Factor 6 agglutinogen. Indirect immunofluorescence studies and immunogold electron microscopy demonstrated that these monoclonal antibodies bind to an outer membrane component on serotype-specific strains of B. pertussis. All of the monoclonal antibodies reacted with native or partially assembled type-specific fimbriae but not with monomeric fimbrial subunits as indicated by Western blot (immunoblot) analysis. The fimbrial agglutinogens recognized by the monoclonal antibodies were also uniquely reactive with either U.S. Reference Factor 2 or 6 antiserum (Eldering agglutinogen 2 or 6 polyclonal antiserum) in an indirect ELISA. No cross-reactivity of the monoclonal antibodies with the unrelated fimbriae was observed in any of the comparative immunological studies. Some of the monoclonal antibodies agglutinated certain strains of B. bronchiseptica, suggesting that this closely related species can contain antigenically similar fimbriae. These monoclonal antibodies should prove useful for further structural and functional analysis of Bordetella fimbriae and for studies on the role that these antigens play in prevention of infection and disease. PMID:2903125

  3. The Life Cycle of Entzia, an Agglutinated Foraminifer from the Salt Marshes in Transylvania

    NASA Astrophysics Data System (ADS)

    Kaminski, Michael; Telespan, Andreea; Balc, Ramona; Filipescu, Sorin; Varga, Ildiko; Görög, Agnes

    2013-04-01

    The small salt marshes associated with Miocene salt domes in Transylvania are host to a variety of marine organisms, including communities of halophytic plants as well as an agglutinated foraminifer that is normally found in coastal salt marshes worldwide. Originally described as the species Entzia tetrastoma by Daday (1884), the foraminifer is more widely known by the name Jadammina macrescens (Brady, 1870). Because the genus name Entzia has priority over Jadammina, the valid name of this taxon is Entzia macrescens (Brady, 1870). In 2007, we discovered a living population of Entzia inhabiting a small salt marsh just outside the town of Turda in central Transylvania, only a kilometer from the famous Maria Theresa Salt Mine. This is the first discovery of a living population of Entzia in Transylvania since the species was originally described in 1884. To determine whether or not the specimens we found represent a breeding population, samples were collected from the marsh on a monthly basis over the span of a year. This species can be found among the roots of the halophytic plants, in the uppermost one or two centimeters of the mud. Sediment samples were preserved in Vodka with Rose Bengal to distinguish living and dead specimens, and examined quantitatively. To document the life cycle of the species the following metrics were carried out: test size, abundance, number of chambers, ratio between live and dead specimens, and the diameter of the proloculus. An increase in the mean diameter of specimens was found from October to December. However the mean diameter decreased again in January, which suggests that asexual reproduction had apparently taken place. Small specimens again appeared in March, when sexual reproduction is presumed to have taken place. The median proloculus diameter was smallest in April and May, but the monthly changes in mean proloculus size within the population over the span of a year are not significant. However, specimens with largest

  4. D-penicillamine prevents ram sperm agglutination by reducing the disulphide bonds of a copper-binding sperm protein.

    PubMed

    Leahy, T; Rickard, J P; Aitken, R J; de Graaf, S P

    2016-05-01

    Head-to-head agglutination of ram spermatozoa is induced by dilution in the Tyrode's capacitation medium with albumin, lactate and pyruvate (TALP) and ameliorated by the addition of the thiol d-penicillamine (PEN). To better understand the association and disassociation of ram spermatozoa, we investigated the mechanism of action of PEN in perturbing sperm agglutination. PEN acts as a chelator of heavy metals, an antioxidant and a reducing agent. Chelation is not the main mechanism of action, as the broad-spectrum chelator ethylenediaminetetraacetic acid and the copper-specific chelator bathocuproinedisulfonic acid were inferior anti-agglutination agents compared with PEN. Oxidative stress is also an unlikely mechanism of sperm association, as PEN was significantly more effective in ameliorating agglutination than the antioxidants superoxide dismutase, ascorbic acid, α-tocopherol and catalase. Only the reducing agents cysteine and DL-dithiothreitol displayed similar levels of non-agglutinated spermatozoa at 0 h compared with PEN but were less effective after 3 h of incubation (37 °C). The addition of 10 µM Cu(2+) to 250 µM PEN + TALP caused a rapid reversion of the motile sperm population from a non-agglutinated state to an agglutinated state. Other heavy metals (cobalt, iron, manganese and zinc) did not provoke such a strong response. Together, these results indicate that PEN prevents sperm association by the reduction of disulphide bonds on a sperm membrane protein that binds copper. ADAM proteins are possible candidates, as targeted inhibition of the metalloproteinase domain significantly increased the percentage of motile, non-agglutinated spermatozoa (52.0% ± 7.8) compared with TALP alone (10.6% ± 6.1).

  5. FERMI-LAT DETECTION OF PULSED GAMMA-RAYS ABOVE 50 GeV FROM THE VELA PULSAR

    SciTech Connect

    Leung, Gene C. K.; Takata, J.; Ng, C. W.; Cheng, K. S.; Kong, A. K. H.; Tam, P. H. T.; Hui, C. Y. E-mail: takata@hku.hk

    2014-12-20

    The first Fermi-Large Area Telescope (LAT) catalog of sources above 10 GeV reported evidence of pulsed emission above 25 GeV from 12 pulsars, including the Vela pulsar, which showed evidence of pulsation at >37 GeV energy bands. Using 62 months of Fermi-LAT data, we analyzed the gamma-ray emission from the Vela pulsar and searched for pulsed emission above 50 GeV. Having confirmed the significance of the pulsation in 30-50 GeV with the H test (p-value ∼10{sup –77}), we extracted its pulse profile using the Bayesian block algorithm and compared it with the distribution of the five observed photons above 50 GeV using the likelihood ratio test. Pulsation was significantly detected for photons above 50 GeV with a p-value of =3 × 10{sup –5} (4.2σ). The detection of pulsation is significant above 4σ at >79 GeV and above 3σ at >90 GeV energy bands, making this the highest energy pulsation significantly detected by the LAT. We explore the non-stationary outer gap scenario of the very high-energy emissions from the Vela pulsar.

  6. Search for Dark Matter Satellites Using the FERMI-LAT

    SciTech Connect

    Ackermann, M.; Albert, A.; Baldini, L.; Ballet, J.; Barbiellini, G.; Bastieri, D.; Bechtol, K.; Bellazzini, R.; Blandford, R.D.; Bloom, E.D.; Bonamente, E.; Borgland, A.W.; Bottacini, E.; Brandt, T.J.; Bregeon, J.; Brigida, M.; Bruel, P.; Buehler, R.; Burnett, T.H.; Caliandro, G.A.; Cameron, R.A.; /more authors..

    2012-08-16

    Numerical simulations based on the {Lambda}CDM model of cosmology predict a large number of as yet unobserved Galactic dark matter satellites. We report the results of a Large Area Telescope (LAT) search for these satellites via the {gamma}-ray emission expected from the annihilation of weakly interacting massive particle (WIMP) dark matter. Some dark matter satellites are expected to have hard {gamma}-ray spectra, finite angular extents, and a lack of counterparts at other wavelengths. We sought to identify LAT sources with these characteristics, focusing on {gamma}-ray spectra consistent with WIMP annihilation through the b{bar b} channel. We found no viable dark matter satellite candidates using one year of data, and we present a framework for interpreting this result in the context of numerical simulations to constrain the velocity-averaged annihilation cross section for a conventional 100 GeV WIMP annihilating through the b{bar b} channel.

  7. LAT Onboard Science: Gamma-Ray Burst Identification

    SciTech Connect

    Kuhn, Frederick; Bonnell, Jerry; Hughes, Richard; Norris, Jay; Ritz, Steven; Russell, James; Smith, Patrick; Winer, Brian; /Ohio State U.

    2007-10-15

    The main goal of the Large Area Telescope (LAT) onboard science program is to provide quick identification and localization of Gamma Ray Bursts (GRB) onboard the LAT for follow-up observations by other observatories. The GRB identification and localization algorithm will provide celestial coordinates with an error region that will be distributed via the Gamma ray burst Coordinate Network (GCN). We present results that show our sensitivity to bursts as characterized using Monte Carlo simulations of the GLAST observatory. We describe and characterize the method of onboard track determination and the GRB identification and localization algorithm. Onboard track determination is considerably different than in the onground case, resulting in a substantially altered point spread function. The algorithm contains tunable parameters which may be adjusted after launch when real bursts characteristics at very high energies have been identified.

  8. LAT Onboard Science: Gamma-Ray Burst Identification

    SciTech Connect

    Kuehn, Frederick; Hughes, Richard; Smith, Patrick; Winer, Brian; Bonnell, Jerry; Norris, Jay; Ritz, Steven; Russell, James

    2007-07-12

    The main goal of the Large Area Telescope (LAT) onboard science program is to provide quick identification and localization of Gamma Ray Bursts (GRB) onboard the LAT for follow-up observations by other observatories. The GRB identification and localization algorithm will provide celestial coordinates with an error region that will be distributed via the Gamma ray burst Coordinate Network (GCN). We present results that show our sensitivity to bursts as characterized using Monte Carlo simulations of the GLAST observatory. We describe and characterize the method of onboard track determination and the GRB identification and localization algorithm. Onboard track determination is considerably different than in the on-ground case, resulting in a substantially altered point spread function. The algorithm contains tunable parameters which may be adjusted after launch when real bursts characteristics at very high energies have been identified.

  9. Search for Dark Matter Satellites Using the Fermi-Lat

    NASA Technical Reports Server (NTRS)

    Ackermann, M.; Albert, A.; Baldini, L.; Ballet, J.; Barbiellini, G.; Bastieri, D.; Bechtol, K.; Bellazzini, R.; Blandford, R. D.; Bloom, E. D.; Bonamente, E.; Borgland, A. W.; Bottacini, E.; Brandt, T. J.; Bregeon, J.; Brigida, M.; Bruel, P.; Buehler, R.; Burnett, T. H.; Caliandro, G. A.; Cameron, R. A.; Caraveo, P. A.; Casandjian, J. M.; McEnery, J. E.; Troja, E.

    2012-01-01

    Numerical simulations based on the ACDM model of cosmology predict a large number of as yet unobserved Galactic dark matter satellites. We report the results of a Large Area Telescope (LAT) search for these satellites via the gamma-ray emission expected from the annihilation of weakly interacting massive particle (WIMP) dark matter. Some dark matter satellites are expected to have hard gamma-ray spectra, finite angular extents, and a lack of counterparts at other wavelengths. We sought to identify LAT sources with these characteristics, focusing on gamma-ray spectra consistent with WIMP annihilation through the bb(sup raised bar) channel. We found no viable dark matter satellite candidates using one year of data, and we present a framework for interpreting this result in the context of numerical simulations to constrain the velocity-averaged annihilation cross section for a conventional 100 Ge V WIMP annihilating through the bb(sup raised bar) channel.

  10. Jacalin: isolation, characterization, and influence of various factors on its interaction with human IgA1, as assessed by precipitation and latex agglutination.

    PubMed

    Hagiwara, K; Collet-Cassart, D; Kobayashi, K; Vaerman, J P

    1988-01-01

    An IgA1-specific lectin, Jacalin, was isolated from dried seeds of the jackfruit, Artocarpus integrifolia, by affinity binding to IgA1-Sepharose and elution with D-galactose. Jacalin is a glycoprotein with two non-covalently bound subunits (15 and 18 K). Interactions between Jacalin and human Igs were studied by precipitation in gel and in solution, and by agglutination of IgA1-coated latex by Jacalin. Jacalin precipitated only with IgA1-containing samples, including monomers, polymers, monoclonal, polyclonal and secretory IgA1, but not IgA2 of both A2m(1) and A2m(2) allotypes, nor with IgG1, 2, 3 and 4, IgM, IgD, and IgE; after neuraminidase treatment, only IgA1 and IgD were precipitated. Jacalin had a relatively broad pH range of activity in both precipitation and agglutination of IgA1-latex. Bivalent metal cations (Ca, Mg, Mn, Cu, Zn, Co, Cd), EDTA, Triton X-100, Tween-20, Na deoxycholate and ionic strength did not influence these reactions. Na dodecylsulphate, guanidine and urea inhibited the reactions whereas NP-40 rather enhanced them. Among 39 types of sugar tested, 10 displayed inhibitory activity, decreasing in the following order: p-nitrophenyl-alpha-D-galactopyranoside, 1-O-methyl-alpha-D-galactopyranoside, D-melibiose, p-nitrophenyl-beta-D-galactopyranoside, GalNAc, stachyose, 1-O-methyl-alpha-D-mannopyranoside, D-galactose, D-galactosamine and 1-O-methyl-alpha-D-glucopyranoside. IgA1, treated with neuraminidase or not, but not the other human Igs, was also an excellent inhibitor of agglutination, being more powerful than the best sugars studied. Only neuraminidase-treated IgD was also inhibitory, but less so than IgA1. Jacalin preferentially bound to alpha-linked non-reducing D-galactose. The configuration of OH-groups at C-2, C-4 and C-6 of D-galactose was important for the reaction. Jacalin recognizes terminal Gal beta 1-3GalNac-, as in the IgA1-hinge, and/or GalNAc-, but not Gal beta 1-4GlcNAc-, nor Gal beta 1-6GlcNAc-, nor their sialylayted

  11. Fermi LAT Stacking Analysis of Swift Localized GRBs

    NASA Astrophysics Data System (ADS)

    Ackermann, M.; Ajello, M.; Anderson, B.; Atwood, W. B.; Axelsson, M.; Baldini, L.; Barbiellini, G.; Bastieri, D.; Bellazzini, R.; Bhat, P. N.; Bissaldi, E.; Bonino, R.; Bottacini, E.; Brandt, T. J.; Bregeon, J.; Bruel, P.; Buehler, R.; Buson, S.; Caliandro, G. A.; Cameron, R. A.; Caragiulo, M.; Caraveo, P. A.; Cecchi, C.; Charles, E.; Chekhtman, A.; Chiang, J.; Chiaro, G.; Ciprini, S.; Claus, R.; Cohen-Tanugi, J.; Conrad, J.; Cutini, S.; D'Ammando, F.; de Angelis, A.; de Palma, F.; Desiante, R.; Di Venere, L.; Drell, P. S.; Favuzzi, C.; Focke, W. B.; Franckowiak, A.; Funk, S.; Fusco, P.; Gargano, F.; Gasparrini, D.; Gehrels, N.; Giglietto, N.; Giordano, F.; Giroletti, M.; Godfrey, G.; Grenier, I. A.; Grove, J. E.; Guiriec, S.; Hewitt, J. W.; Hill, A. B.; Horan, D.; Jóhannesson, G.; Kocevski, D.; Kouveliotou, C.; Kuss, M.; Larsson, S.; Li, J.; Li, L.; Longo, F.; Loparco, F.; Lovellette, M. N.; Lubrano, P.; Mayer, M.; Mazziotta, M. N.; McEnery, J. E.; Michelson, P. F.; Mizuno, T.; Monzani, M. E.; Morselli, A.; Murgia, S.; Nemmen, R.; Nuss, E.; Ohno, M.; Ohsugi, T.; Omodei, N.; Orienti, M.; Orlando, E.; Paneque, D.; Perkins, J. S.; Pesce-Rollins, M.; Piron, F.; Pivato, G.; Porter, T. A.; Racusin, J. L.; Rainò, S.; Rando, R.; Razzano, M.; Reimer, A.; Reimer, O.; Schaal, M.; Schulz, A.; Sgrò, C.; Siskind, E. J.; Spada, F.; Spandre, G.; Spinelli, P.; Takahashi, H.; Thayer, J. B.; Tibaldo, L.; Tinivella, M.; Torres, D. F.; Tosti, G.; Troja, E.; Vianello, G.; von Kienlin, A.; Werner, M.; Wood, K. S.

    2016-05-01

    We perform a comprehensive stacking analysis of data collected by the Fermi Large Area Telescope (LAT) of γ-ray bursts (GRBs) localized by the Swift spacecraft, which were not detected by the LAT but which fell within the instrument’s field of view at the time of trigger. We examine a total of 79 GRBs by comparing the observed counts over a range of time intervals to that expected from designated background orbits, as well as by using a joint likelihood technique to model the expected distribution of stacked counts. We find strong evidence for subthreshold emission at MeV to GeV energies using both techniques. This observed excess is detected during intervals that include and exceed the durations typically characterizing the prompt emission observed at keV energies and lasts at least 2700 s after the co-aligned burst trigger. By utilizing a novel cumulative likelihood analysis, we find that although a burst’s prompt γ-ray and afterglow X-ray flux both correlate with the strength of the subthreshold emission, the X-ray afterglow flux measured by Swift’s X-ray Telescope at 11 hr post trigger correlates far more significantly. Overall, the extended nature of the subthreshold emission and its connection to the burst’s afterglow brightness lend further support to the external forward shock origin of the late-time emission detected by the LAT. These results suggest that the extended high-energy emission observed by the LAT may be a relatively common feature but remains undetected in a majority of bursts owing to instrumental threshold effects.

  12. Evaluation of the Monotonic Lagrangian Grid and Lat-Long Grid for Air Traffic Management

    NASA Technical Reports Server (NTRS)

    Kaplan, Carolyn; Dahm, Johann; Oran, Elaine; Alexandrov, Natalia; Boris, Jay

    2011-01-01

    The Air Traffic Monotonic Lagrangian Grid (ATMLG) is used to simulate a 24 hour period of air traffic flow in the National Airspace System (NAS). During this time period, there are 41,594 flights over the United States, and the flight plan information (departure and arrival airports and times, and waypoints along the way) are obtained from an Federal Aviation Administration (FAA) Enhanced Traffic Management System (ETMS) dataset. Two simulation procedures are tested and compared: one based on the Monotonic Lagrangian Grid (MLG), and the other based on the stationary Latitude-Longitude (Lat- Long) grid. Simulating one full day of air traffic over the United States required the following amounts of CPU time on a single processor of an SGI Altix: 88 s for the MLG method, and 163 s for the Lat-Long grid method. We present a discussion of the amount of CPU time required for each of the simulation processes (updating aircraft trajectories, sorting, conflict detection and resolution, etc.), and show that the main advantage of the MLG method is that it is a general sorting algorithm that can sort on multiple properties. We discuss how many MLG neighbors must be considered in the separation assurance procedure in order to ensure a five-mile separation buffer between aircraft, and we investigate the effect of removing waypoints from aircraft trajectories. When aircraft choose their own trajectory, there are more flights with shorter duration times and fewer CD&R maneuvers, resulting in significant fuel savings.

  13. Gamma-ray blazars and active galactic nuclei seen by the Fermi-LAT

    NASA Astrophysics Data System (ADS)

    Lott, B.; Cavazzuti, E.; Ciprini, S.; Cutini, S.; Gasparrini, D.

    2015-03-01

    The third catalog of active galactic nuclei (AGNs) detected by the Fermi-LAT (3LAC) is presented. It is based on the third Fermi-LAT catalog (3FGL) of sources detected with a test statistic (TS) greater than 25 using the first 4 years of data. The 3LAC includes 1591 AGNs located at high Galactic latitudes, |b| > 10 (with 28 duplicate associations, thus corresponding to 1563 gamma-ray sources among 2192 sources in the 3FGL catalog), a 71% increase over the second catalog based on 2 years of data. A very large majority of these AGNs (98%) are blazars. About half of the newly detected blazars are of unknown type, i.e., they lack spectroscopic information of sufficient quality to determine the strength of their emission lines. The general properties of the 3LAC sample confirm previous findings from earlier catalogs, but some new subclasses (e.g., intermediate- and high-synchrotron-peaked FSRQs) have now been significantly detected.

  14. Five Years of the Fermi LAT Flare Advocate

    NASA Astrophysics Data System (ADS)

    Carpenter, Bryce; Ojha, R.; Gasparrini, D.; Ciprini, S.; Fermi LAT Collaboration; Fermi LAT Flare Advocates

    2014-01-01

    Since the launch of the Fermi satellite, the Fermi Large Area Telescope (LAT) team has run a program that provides a daily review of the the gamma-ray sky as soon as Fermi LAT data becomes available. The Flare Advocate/Gamma-ray Sky Watcher (FA-GSW) program allows a rapid analysis of the Automatic Science Processing (ASP) products and triggers dedicated followup analyses by several LAT science groups such as those studying Galactic transients, extragalactic sources and new gamma-ray sources. Significant gamma-ray detections also trigger rapid communications to the entire astrophysical community via astronomical telegrams and gamma-ray coordination network notices. The FA-GSW program plays a key role in maximizing the science return from Fermi by increasing the rate of multi-frequency observations of sources in an active gamma-ray state. In the past ~5 years blazar flaring activity of varying strength and duty cycles, gravitationally lensed blazars, flares from Galactic sources (like Nova Delphini and the Crab Nebula), unidentified transients near and off the Galactic plane, and emission from the quiet and flaring Sun, represent the range of detections made. Flare Advocates have published about 250 Astronomical Telegrams and they publish a weekly blog. Timely, extensive multi-frequency campaigns have been organized to follow-up on these phenomena leading to some of Fermi’s most interesting results.

  15. Constraining decaying dark matter with Fermi LAT gamma-rays

    SciTech Connect

    Zhang, Le; Sigl, Günter; Weniger, Christoph; Maccione, Luca; Redondo, Javier E-mail: christoph.weniger@desy.de E-mail: redondo@mppmm.mpg.de

    2010-06-01

    High energy electrons and positrons from decaying dark matter can produce a significant flux of gamma rays by inverse Compton off low energy photons in the interstellar radiation field. This possibility is inevitably related with the dark matter interpretation of the observed PAMELA and FERMI excesses. The aim of this paper is providing a simple and universal method to constrain dark matter models which produce electrons and positrons in their decay by using the Fermi LAT gamma-ray observations in the energy range between 0.5 GeV and 300 GeV. We provide a set of universal response functions that, once convolved with a specific dark matter model produce the desired constraints. Our response functions contain all the astrophysical inputs such as the electron propagation in the galaxy, the dark matter profile, the gamma-ray fluxes of known origin, and the Fermi LAT data. We study the uncertainties in the determination of the response functions and apply them to place constraints on some specific dark matter decay models that can well fit the positron and electron fluxes observed by PAMELA and Fermi LAT. To this end we also take into account prompt radiation from the dark matter decay. We find that with the available data decaying dark matter cannot be excluded as source of the PAMELA positron excess.

  16. Limits on dark matter annihilation signals from the Fermi LAT 4-year measurement of the isotropic gamma-ray background

    SciTech Connect

    Collaboration: Fermi LAT Collaboration

    2015-09-01

    We search for evidence of dark matter (DM) annihilation in the isotropic gamma-ray background (IGRB) measured with 50 months of Fermi Large Area Telescope (LAT) observations. An improved theoretical description of the cosmological DM annihilation signal, based on two complementary techniques and assuming generic weakly interacting massive particle (WIMP) properties, renders more precise predictions compared to previous work. More specifically, we estimate the cosmologically-induced gamma-ray intensity to have an uncertainty of a factor ∼ 20 in canonical setups. We consistently include both the Galactic and extragalactic signals under the same theoretical framework, and study the impact of the former on the IGRB spectrum derivation. We find no evidence for a DM signal and we set limits on the DM-induced isotropic gamma-ray signal. Our limits are competitive for DM particle masses up to tens of TeV and, indeed, are the strongest limits derived from Fermi LAT data at TeV energies. This is possible thanks to the new Fermi LAT IGRB measurement, which now extends up to an energy of 820 GeV. We quantify uncertainties in detail and show the potential this type of search offers for testing the WIMP paradigm with a complementary and truly cosmological probe of DM particle signals.

  17. Limits on dark matter annihilation signals from the Fermi LAT 4-year measurement of the isotropic gamma-ray background

    SciTech Connect

    Ackermann, M.

    2015-09-02

    We search for evidence of dark matter (DM) annihilation in the isotropic gamma-ray background (IGRB) measured with 50 months of Fermi Large Area Telescope (LAT) observations. An improved theoretical description of the cosmological DM annihilation signal, based on two complementary techniques and assuming generic weakly interacting massive particle (WIMP) properties, renders more precise predictions compared to previous work. More specifically, we estimate the cosmologically-induced gamma-ray intensity to have an uncertainty of a factor ~ 20 in canonical setups. We consistently include both the Galactic and extragalactic signals under the same theoretical framework, and study the impact of the former on the IGRB spectrum derivation. We find no evidence for a DM signal and we set limits on the DM-induced isotropic gamma-ray signal. Our limits are competitive for DM particle masses up to tens of TeV and, indeed, are the strongest limits derived from Fermi LAT data at TeV energies. This is possible thanks to the new Fermi LAT IGRB measurement, which now extends up to an energy of 820 GeV. As a result, we quantify uncertainties in detail and show the potential this type of search offers for testing the WIMP paradigm with a complementary and truly cosmological probe of DM particle signals.

  18. Limits on dark matter annihilation signals from the Fermi LAT 4-year measurement of the isotropic gamma-ray background

    DOE PAGES

    Ackermann, M.

    2015-09-02

    We search for evidence of dark matter (DM) annihilation in the isotropic gamma-ray background (IGRB) measured with 50 months of Fermi Large Area Telescope (LAT) observations. An improved theoretical description of the cosmological DM annihilation signal, based on two complementary techniques and assuming generic weakly interacting massive particle (WIMP) properties, renders more precise predictions compared to previous work. More specifically, we estimate the cosmologically-induced gamma-ray intensity to have an uncertainty of a factor ~ 20 in canonical setups. We consistently include both the Galactic and extragalactic signals under the same theoretical framework, and study the impact of the former onmore » the IGRB spectrum derivation. We find no evidence for a DM signal and we set limits on the DM-induced isotropic gamma-ray signal. Our limits are competitive for DM particle masses up to tens of TeV and, indeed, are the strongest limits derived from Fermi LAT data at TeV energies. This is possible thanks to the new Fermi LAT IGRB measurement, which now extends up to an energy of 820 GeV. As a result, we quantify uncertainties in detail and show the potential this type of search offers for testing the WIMP paradigm with a complementary and truly cosmological probe of DM particle signals.« less

  19. Latex agglutination assays for detection of non-O157 Shiga toxin-producing Escherichia coli serogroups O26, O45, O103, O111, O121, and O145.

    PubMed

    Medina, Marjorie B; Shelver, Weilin L; Fratamico, Pina M; Fortis, Laurie; Tillman, Glenn; Narang, Neelam; Cray, William C; Esteban, Emilio; Debroy, Andchitrita

    2012-05-01

    Latex agglutination assays utilizing polyclonal antibodies were developed for the top six non-O157 Shiga toxin-producing Escherichia coli (STEC) serogroups. Rabbit antisera were affinity purified through protein A/G columns, and the isolated immunoglobulins (IgGs) were covalently immobilized onto polystyrene latex particles. The resulting latex-IgG complex had a protein (IgG) load of 0.20 to 0.28 mg/ml in a 1% latex suspension. Optimum conditions for the agglutination assay consisted of utilizing 20 μm l of latex-IgG reagent containing 2.0 to 2.8 μm g IgG in a 0.5% latex suspension. Agglutination or flocculation was observed almost instantly after mixing the colonies with the latex-IgG, indicating STEC strains. More than 100 target and nontarget strains were tested in more than 3,000 test replicates. All target organisms produced positive results, but three antisera (anti-O26, anti-O103, and anti-O145) cross-reacted with some other STECs. The anti-O103 and anti-O145 latex reagents cross-reacted with O26 strains, and the anti-O26 cross-reacted with O103 strains. The latex-IgG reagents are stable for at least 1 year and are easy to prepare. These agglutination assays can be used for identification of presumptive non-O157 STEC colonies from agar media. The techniques used to prepare the latex reagents also can be utilized for testing other STEC serogroups, other E. coli serotypes, or other pathogens to ensure safe foods to consumers.

  20. Latex agglutination assays for detection of non-O157 Shiga toxin-producing Escherichia coli serogroups O26, O45, O103, O111, O121, and O145.

    PubMed

    Medina, Marjorie B; Shelver, Weilin L; Fratamico, Pina M; Fortis, Laurie; Tillman, Glenn; Narang, Neelam; Cray, William C; Esteban, Emilio; Debroy, Andchitrita

    2012-05-01

    Latex agglutination assays utilizing polyclonal antibodies were developed for the top six non-O157 Shiga toxin-producing Escherichia coli (STEC) serogroups. Rabbit antisera were affinity purified through protein A/G columns, and the isolated immunoglobulins (IgGs) were covalently immobilized onto polystyrene latex particles. The resulting latex-IgG complex had a protein (IgG) load of 0.20 to 0.28 mg/ml in a 1% latex suspension. Optimum conditions for the agglutination assay consisted of utilizing 20 μm l of latex-IgG reagent containing 2.0 to 2.8 μm g IgG in a 0.5% latex suspension. Agglutination or flocculation was observed almost instantly after mixing the colonies with the latex-IgG, indicating STEC strains. More than 100 target and nontarget strains were tested in more than 3,000 test replicates. All target organisms produced positive results, but three antisera (anti-O26, anti-O103, and anti-O145) cross-reacted with some other STECs. The anti-O103 and anti-O145 latex reagents cross-reacted with O26 strains, and the anti-O26 cross-reacted with O103 strains. The latex-IgG reagents are stable for at least 1 year and are easy to prepare. These agglutination assays can be used for identification of presumptive non-O157 STEC colonies from agar media. The techniques used to prepare the latex reagents also can be utilized for testing other STEC serogroups, other E. coli serotypes, or other pathogens to ensure safe foods to consumers. PMID:22564929

  1. Development of a particle agglutination assay system for detecting Japanese encephalitis virus-specific human IgM, using hydroxyapatite-coated nylon beads.

    PubMed

    Yamamoto, Akira; Nakayama, Mikio; Kurosawa, Yae; Sugo, Ken; Karasawa, Hideharu; Ogawa, Tetsuro; Takasaki, Tomohiko; Tashiro, Masato; Kurane, Ichiro

    2002-07-01

    Japanese encephalitis virus-specific IgM is a reliable indicator for serodiagnosis of Japanese encephalitis. A particle agglutination (PA) assay system was developed to detect anti-Japanese encephalitis virus IgM in human serum samples. The newly developed PA assay consisted of hydroxyapatite-coated nylon beads and V-bottom 96-well microplates. Hydroxyapatite-coated nylon beads were coated with Japanese encephalitis virus antigens. Japanese encephalitis virus antigen-coated, hydroxyapatite-coated nylon beads agglutinated in the IgM-captured wells when anti-Japanese encephalitis virus IgM-positive serum samples were used. A button pattern was formed at the bottom of the wells when anti-Japanese encephalitis virus IgM-negative serum samples were used. Thirty anti-Japanese encephalitis virus IgM-positive serum samples from Japanese encephalitis-confirmed cases were tested by the PA assay. All these serum samples were determined to be Japanese encephalitis virus IgM-positive. IgM titers determined by the PA assay corresponded to those determined by enzyme-linked immunosorbent assay. The titers were consistent in two independent PA assays. These results indicate that the newly developed PA assay is a reliable method for detecting anti-Japanese encephalitis virus IgM in human serum samples and that this assay will be a suitable diagnostic system especially in rural areas of Asia.

  2. Kinetics and time dependence of the differential agglutination of acetone [AC]- and formalin [HS]-fixed Toxoplasma tachyzoites by serum of mice with experimental toxoplasmosis.

    PubMed

    Ali, Nehad Mahmoud; Habib, Khaled Sayed Mohamed

    2012-04-01

    Researches to specify a serologic diagnostic test capable of determining the stage of toxoplasmosis, whether recent or latent, have been hampered by lack of knowing the real time of infection. Studying the precise kinetics of the differential agglutination of acetone [AC]-fixed versus that of formalin [HS]-fixed tachyzoites (differential agglutination test or AC/HS test) by sera of mice during the course of toxoplasmosis and assessment of its value in the differentiation between recent and latent infections in mice were the aims of the present work. Experimental toxoplasmosis was induced in mice, sera were collected sequentially and AC/HS test, FAST-ELISA to determine levels of IgM and IgG and microscopic examination of brain for Toxoplasma cysts were done. Both AC and HS specific patterns in the AC/HS test were noted to be dependent on the time from the onset of infection. Acute patterns of the AC/HS test were observed early in infection till before the appearance of brain cysts. Non-acute patterns were obtained late on 28th day post infection coinciding with the disappearance of IgM, persistence of IgG and presence of cysts in brains. The AC antibody was high in the recent phase of infection, and then it declined to be replaced by high sustained level of HS antibody late in infection. In conclusion, in the presence of both IgM and IgG, the appearance of either equivocal pattern or the non-acute pattern in the AC/HS test is significant in ruling out acute infection in mice.

  3. Nanoscale Mineralogy and Composition of Experimental Regolith Agglutinates Produced under Asteroidal Impact Conditions

    NASA Technical Reports Server (NTRS)

    Christoffersen, Roy; Cintala, M. J.; Keller, L. P.; See, T. H.; Horz, F.

    2013-01-01

    On the Moon, the energetics of smaller impactors and the physical/chemical characteristics of the granular regolith target combine to form a key product of lunar space weathering: chemically reduced shock melts containing optically-active nanophase Fe metal grains (npFe0) [1]. In addition to forming the optically dark glassy matrix phase in lunar agglutinitic soil particles [1], these shock melts are becoming increasingly recognized for their contribution to optically active patina coatings on a wide range of exposed rock and grain surfaces in the lunar regolith [2]. In applying the lessons of lunar space weathering to asteroids, the potential similarities and differences in regolith-hosted shock melts on the Moon compared to those on asteroids has become a topic of increasing interest [3,4]. In a series of impact experiments performed at velocities applicable to the asteroid belt [5], Horz et al. [6] and See and Horz [7] have previously shown that repeated impacts into a gabbroic regolith analog target can produce melt-welded grain aggregates morphologically very similar to lunar agglutinates [6,7]. Although these agglutinate-like particles were extensively analyzed by electron microprobe and scanning electron microscopy (SEM) as part of the original study [7], a microstructural and compositional comparison of these aggregates to lunar soil agglutinates at sub-micron scales has yet to be made. To close this gap, we characterized a representative set of these aggregates using a JEOL 7600 field-emission scanning electron microscope (FE-SEM), and JEOL 2500SE field-emission scanning transmission electron microscope (FE-STEM) both optimized for energy dispersive X-ray spectroscopy (EDX) compositional spectrum imaging at respective analytical spatial resolutions of 0.5 to 1 micron, and 2 to 4 nm.

  4. Local hydrocortisone treatment of sperm-agglutinating antibodies in infertile women.

    PubMed

    Ulcová-Gallová, Z; Mráz, L; Plánicková, E; Macků, F; Ulc, I

    1988-01-01

    Local sperm-agglutinating antibodies (LSAA) in the cervical ovulatory mucus may be a cause of primary infertility. A group of 17 infertile women with LSAA treated without effect with artificial insemination and then condom therapy were studied. After hydrocortisone application to the ectocervix for up to four cycles, LSAA disappeared totally in 13 patients; six of them have given birth to babies. No side effects of treatment were observed. Hydrocortisone for local immunosuppression may become a new method of therapy in cervical immunological infertility.

  5. A sperm-agglutinating lectin from seeds of Jack fruit (Artocarpus heterophyllus).

    PubMed

    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).

  6. The LATS2 tumor suppressor inhibits SREBP and suppresses hepatic cholesterol accumulation

    PubMed Central

    Aylon, Yael; Gershoni, Anat; Rotkopf, Ron; Biton, Inbal E.; Porat, Ziv; Koh, Anna P.; Sun, Xiaochen; Lee, Youngmin; Fiel, Maria-Isabel; Hoshida, Yujin; Friedman, Scott L.; Johnson, Randy L.; Oren, Moshe

    2016-01-01

    The Hippo signaling pathway is a major regulator of organ size. In the liver, Hippo pathway deregulation promotes hyperplasia and hepatocellular carcinoma primarily through hyperactivation of its downstream effector, YAP. The LATS2 tumor suppressor is a core member of the Hippo pathway. A screen for LATS2-interacting proteins in liver-derived cells identified the transcription factor SREBP2, master regulator of cholesterol homeostasis. LATS2 down-regulation caused SREBP activation and accumulation of excessive cholesterol. Likewise, mice harboring liver-specific Lats2 conditional knockout (Lats2-CKO) displayed constitutive SREBP activation and overexpressed SREBP target genes and developed spontaneous fatty liver disease. Interestingly, the impact of LATS2 depletion on SREBP-mediated transcription was clearly distinct from that of YAP overexpression. When challenged with excess dietary cholesterol, Lats2-CKO mice manifested more severe liver damage than wild-type mice. Surprisingly, apoptosis, inflammation, and fibrosis were actually attenuated relative to wild-type mice, in association with impaired p53 activation. Subsequently, Lats2-CKO mice failed to recover effectively from cholesterol-induced damage upon return to a normal diet. Additionally, decreased LATS2 mRNA in association with increased SREBP target gene expression was observed in a subset of human nonalcoholic fatty liver disease cases. Together, these findings further highlight the tight links between tumor suppressors and metabolic homeostasis. PMID:27013235

  7. The Search for Milky Way Halo Substructure WIMP Annihilations Using the GLAST LAT

    SciTech Connect

    Wai, Larry; /SLAC

    2007-02-05

    The GLAST LAT Collaboration is one among several experimental groups, covering a wide range of approaches, pursuing the search for the nature of dark matter. The GLAST LAT has the unique ability to find new sources of high energy gamma radiation emanating directly from WIMP annihilations in situ in the universe. Using it's wide band spectral and full sky spatial capabilities, the GLAST LAT can form ''images'' in high energy gamma-rays of dark matter substructures in the gamma-ray sky. We describe a preliminary feasibility study for indirect detection of milky way dark matter satellites using the GLAST LAT.

  8. High influx of carbon in walls of agglutinated foraminifers during the Permian-Triassic transition in global oceans

    USGS Publications Warehouse

    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.

  9. Legionella species and serogroups in Malaysian water cooling towers: identification by latex agglutination and PCR-DNA sequencing of isolates.

    PubMed

    Yong, Stacey Foong Yee; Goh, Fen-Ning; Ngeow, Yun Fong

    2010-03-01

    In this study, we investigated the distribution of Legionella species in water cooling towers located in different parts of Malaysia to obtain information that may inform public health policies for the prevention of legionellosis. A total of 20 water samples were collected from 11 cooling towers located in three different states in east, west and south Malaysia. The samples were concentrated by filtration and treated with an acid buffer before plating on to BCYE agar. Legionella viable counts in these samples ranged from 100 to 2,000 CFU ml(-1); 28 isolates from the 24 samples were examined by latex agglutination as well as 16S rRNA and rpoB PCR-DNA sequencing. These isolates were identified as Legionella pneumophila serogroup 1 (35.7%), L. pneumophila serogroup 2-14 (39%), L. pneumophila non-groupable (10.7%), L. busanensis, L. gormanii, L. anisa and L. gresilensis. L. pneumophila was clearly the predominant species at all sampling sites. Repeat sampling from the same cooling tower and testing different colonies from the same water sample showed concurrent colonization by different serogroups and different species of Legionella in some of the cooling towers. PMID:20009251

  10. Antimicrobial Action and Cell Agglutination by the Eosinophil Cationic Protein Are Modulated by the Cell Wall Lipopolysaccharide Structure

    PubMed Central

    Pulido, David; Moussaoui, Mohammed; Andreu, David; Nogués, M. Victòria

    2012-01-01

    Antimicrobial proteins and peptides (AMPs) are essential effectors of innate immunity, acting as a first line of defense against bacterial infections. Many AMPs exhibit high affinity for cell wall structures such as lipopolysaccharide (LPS), a potent endotoxin able to induce sepsis. Hence, understanding how AMPs can interact with and neutralize LPS endotoxin is of special relevance for human health. Eosinophil cationic protein (ECP) is an eosinophil secreted protein with high activity against both Gram-negative and Gram-positive bacteria. ECP has a remarkable affinity for LPS and a distinctive agglutinating activity. By using a battery of LPS-truncated E. coli mutant strains, we demonstrate that the polysaccharide moiety of LPS is essential for ECP-mediated bacterial agglutination, thereby modulating its antimicrobial action. The mechanism of action of ECP at the bacterial surface is drastically affected by the LPS structure and in particular by its polysaccharide moiety. We have also analyzed an N-terminal fragment that retains the whole protein activity and displays similar cell agglutination behavior. Conversely, a fragment with further minimization of the antimicrobial domain, though retaining the antimicrobial capacity, significantly loses its agglutinating activity, exhibiting a different mechanism of action which is not dependent on the LPS composition. The results highlight the correlation between the protein's antimicrobial activity and its ability to interact with the LPS outer layer and promote bacterial agglutination. PMID:22330910

  11. Antimicrobial action and cell agglutination by the eosinophil cationic protein are modulated by the cell wall lipopolysaccharide structure.

    PubMed

    Pulido, David; Moussaoui, Mohammed; Andreu, David; Nogués, M Victòria; Torrent, Marc; Boix, Ester

    2012-05-01

    Antimicrobial proteins and peptides (AMPs) are essential effectors of innate immunity, acting as a first line of defense against bacterial infections. Many AMPs exhibit high affinity for cell wall structures such as lipopolysaccharide (LPS), a potent endotoxin able to induce sepsis. Hence, understanding how AMPs can interact with and neutralize LPS endotoxin is of special relevance for human health. Eosinophil cationic protein (ECP) is an eosinophil secreted protein with high activity against both Gram-negative and Gram-positive bacteria. ECP has a remarkable affinity for LPS and a distinctive agglutinating activity. By using a battery of LPS-truncated E. coli mutant strains, we demonstrate that the polysaccharide moiety of LPS is essential for ECP-mediated bacterial agglutination, thereby modulating its antimicrobial action. The mechanism of action of ECP at the bacterial surface is drastically affected by the LPS structure and in particular by its polysaccharide moiety. We have also analyzed an N-terminal fragment that retains the whole protein activity and displays similar cell agglutination behavior. Conversely, a fragment with further minimization of the antimicrobial domain, though retaining the antimicrobial capacity, significantly loses its agglutinating activity, exhibiting a different mechanism of action which is not dependent on the LPS composition. The results highlight the correlation between the protein's antimicrobial activity and its ability to interact with the LPS outer layer and promote bacterial agglutination.

  12. 9 CFR 147.1 - The standard tube agglutination test. 1

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... should be incubated 48 hours at 37 °C., and the surface growth washed off with sufficient phenolized (0.5... surface growth washed off with sufficient phenolized (0.5 percent) saline (0.85 percent) solution to make... percent) solution containing 0.5 percent phenol. After the bacterial mass has been uniformly suspended...

  13. 9 CFR 147.1 - The standard tube agglutination test. 1

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... should be incubated 48 hours at 37 °C., and the surface growth washed off with sufficient phenolized (0.5... surface growth washed off with sufficient phenolized (0.5 percent) saline (0.85 percent) solution to make... percent) solution containing 0.5 percent phenol. After the bacterial mass has been uniformly suspended...

  14. 9 CFR 147.1 - The standard tube agglutination test. 1

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... should be incubated 48 hours at 37 °C., and the surface growth washed off with sufficient phenolized (0.5... surface growth washed off with sufficient phenolized (0.5 percent) saline (0.85 percent) solution to make... percent) solution containing 0.5 percent phenol. After the bacterial mass has been uniformly suspended...

  15. 9 CFR 147.1 - The standard tube agglutination test. 1

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... should be incubated 48 hours at 37 °C., and the surface growth washed off with sufficient phenolized (0.5... surface growth washed off with sufficient phenolized (0.5 percent) saline (0.85 percent) solution to make... percent) solution containing 0.5 percent phenol. After the bacterial mass has been uniformly suspended...

  16. 9 CFR 147.1 - The standard tube agglutination test. 1

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... should be incubated 48 hours at 37 °C., and the surface growth washed off with sufficient phenolized (0.5... surface growth washed off with sufficient phenolized (0.5 percent) saline (0.85 percent) solution to make... percent) solution containing 0.5 percent phenol. After the bacterial mass has been uniformly suspended...

  17. A Possible Role for Agglutinated Foraminifers in the Growth of Deep-Water Coral Bioherms

    NASA Astrophysics Data System (ADS)

    Messing, C. G.; Reed, J. K.; Brooke, S. D.

    2008-05-01

    Exploration of deep-water bioherms dominated by the scleractinian corals Lophelia pertusa and Enallopsammia profunda along the east coast of Florida in ~400-800 m depth reveals an often dense and rich assemblage of small (~1-30 mm) epifauna on dead coral branches, which is often dominated by agglutinated astrorhizacean foraminifers accompanied by thecate and athecate hydroids, sponges, stylasterids, anemones and barnacles. The dominant agglutinated foraminifer is an arborescent form up to 15 mm tall, consisting of a basal tube that gives rise to branchlets of successively decreasing diameter and thickly coated with fine-grained material including coccoliths and diatom frustules. The large numbers of foraminifers generate an enormous adhesive, sediment-trapping surface area and may represent an important accelerated route for sediment deposition and bioherm growth relative to baffling of suspended sediment particles by the coral branches themselves. These foraminifers also occur on still living coral, suggesting that they may either contribute to coral death or invade stressed colonies. They may thus be responsible for or contribute to the small percent of living corals observed in many of these habitats. Other epifauna appear to colonize after the coral has died.

  18. Homogeneous agglutination assay based on micro-chip sheathless flow cytometry.

    PubMed

    Ma, Zengshuai; Zhang, Pan; Cheng, Yinuo; Xie, Shuai; Zhang, Shuai; Ye, Xiongying

    2015-11-01

    Homogeneous assays possess important advantages that no washing or physical separation is required, contributing to robust protocols and easy implementation which ensures potential point-of-care applications. Optimizing the detection strategy to reduce the number of reagents used and simplify the detection device is desirable. A method of homogeneous bead-agglutination assay based on micro-chip sheathless flow cytometry has been developed. The detection processes include mixing the capture-probe conjugated beads with an analyte containing sample, followed by flowing the reaction mixtures through the micro-chip sheathless flow cytometric device. The analyte concentrations were detected by counting the proportion of monomers in the reaction mixtures. Streptavidin-coated magnetic beads and biotinylated bovine serum albumin (bBSA) were used as a model system to verify the method, and detection limits of 0.15 pM and 1.5 pM for bBSA were achieved, using commercial Calibur and the developed micro-chip sheathless flow cytometric device, respectively. The setup of the micro-chip sheathless flow cytometric device is significantly simple; meanwhile, the system maintains relatively high sensitivity, which mainly benefits from the application of forward scattering to distinguish aggregates from monomers. The micro-chip sheathless flow cytometric device for bead agglutination detection provides us with a promising method for versatile immunoassays on microfluidic platforms.

  19. Ethanol induces human red cell shape transformations and enhanced ligand-mediated agglutinability

    SciTech Connect

    Weinstein, R.S.; McLawhon, R.W.; Marikovsky, Y.

    1986-03-01

    Ethanol concentrations are markedly elevated in rat stomach wall when ulcerogenic doses of 100 % ethanol (2 ml for 5 to 10 minutes) are instilled in rat gastric lumen. The authors observed that red cells in gastric mucosal postcapillary venules become spiculated and interadherent under these conditions. The authors have now studied this phenomenon in vitro using washing human red cells. Concentrations of high grade ethanol ranging from 2 to 10% (v/v) in physiological buffered saline (pH 7.3) without Ca/sup + +/ or Mg/sup + +/ at 25/sup 0/C rapidly transformed human red cells into spiculated forms. 2% ethanol transformed human red cells into disco-echinocytes in 15 min. whereas 10% ethanol transformed red blood cells into echinocytes within 3 min. Washing out of ethanol at 1 hour reverted the echinocytes into discocytes. However, following 3 hours of incubation in 10% ethanol washing out of ethanol produced stomatocytes. The ethanol-induced echinocytic shape transformations were accompanied by a dose-related increase in red cell agglutinability with poly-L-lysine or the plant lectin wheat germ agglutinin. The enhanced agglutinability was reversed by restoring the red cell shape changes and alterations in surface properties may play a role in the pathogenesis of ethanol-induced gastric ulcers.

  20. Proposed method for agglutinating antibody titer analysis and its use as indicator of acquired immunity in pacu, Piaractus mesopotamicus.

    PubMed

    Biller-Takahashi, J D; Montassier, H J; Takahashi, L S; Urbinati, E C

    2014-02-01

    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.

  1. Pulsars above 10 GeV: Fermi LAT Observations and Questions

    NASA Technical Reports Server (NTRS)

    Thomson, Dave

    2012-01-01

    The success of the Fermi Large Area Telescope in studying gamma-ray pulsars offers hints about future work above 10 GeV. The infrastructure for discovering pulsars will be similar between LAT and any future telescope. Some of the Fermi LAT results suggest intriguing questions about the future of high-energy pulsar studies.

  2. Reciprocal regulation of amino acid import and epigenetic state through Lat1 and EZH2

    PubMed Central

    Dann, Stephen G; Ryskin, Michael; Barsotti, Anthony M; Golas, Jonathon; Shi, Celine; Miranda, Miriam; Hosselet, Christine; Lemon, Luanna; Lucas, Judy; Karnoub, Maha; Wang, Fang; Myers, Jeremy S; Garza, Scott J; Follettie, Maximillian T; Geles, Kenneth G; Klippel, Anke; Rollins, Robert A; Fantin, Valeria R

    2015-01-01

    Lat1 (SLC7A5) is an amino acid transporter often required for tumor cell import of essential amino acids (AA) including Methionine (Met). Met is the obligate precursor of S-adenosylmethionine (SAM), the methyl donor utilized by all methyltransferases including the polycomb repressor complex (PRC2)-specific EZH2. Cell populations sorted for surface Lat1 exhibit activated EZH2, enrichment for Met-cycle intermediates, and aggressive tumor growth in mice. In agreement, EZH2 and Lat1 expression are co-regulated in models of cancer cell differentiation and co-expression is observed at the invasive front of human lung tumors. EZH2 knockdown or small-molecule inhibition leads to de-repression of RXRα resulting in reduced Lat1 expression. Our results describe a Lat1-EZH2 positive feedback loop illustrated by AA depletion or Lat1 knockdown resulting in SAM reduction and concomitant reduction in EZH2 activity. shRNA-mediated knockdown of Lat1 results in tumor growth inhibition and points to Lat1 as a potential therapeutic target. PMID:25979827

  3. Why doesn't lat/lon calculated by the GCTP projection parameters match lat/lon report in the Latitude / Longitude fields in the product? Which fields are affected by the geolocation problem?

    Atmospheric Science Data Center

    2014-12-08

    ... and "Longitude" fields which explicitly specify the lat/lon location for the center of each pixel. The "Latitude" and "Longitude" ... geolocation information. By comparing the implicit lat/lon against the explicit lat/lon, one can determine which pixels have been ...

  4. Annihilation Lines from Dark Matter with the Fermi-LAT

    SciTech Connect

    Ylinen, Tomi

    2010-06-23

    Dark matter is today one of the most intriguing but so far unresolved issues in physics. Many extensions of the Standard Model of particle physics predict a stable Weakly Interacting Massive Particle (WIMP) that may annihilate directly into two gamma-rays. If the WIMPs are non-relativistic, the gamma-rays from this channel will have an energy equal to the mass of the WIMP. The signature caused by this annihilation is a spectral line, smeared out only by the energy resolution of the detector. The signal would be a ''smoking gun'' for dark matter, since no other astrophysical source should be able to produce it. We present here the preliminary results from the search for a dark matter line on a limited data set from the Fermi Large Area Telescope (LAT), the main instrument onboard the Fermi Gamma-ray Space Telescope, which was successfully launched on June 11, 2008. The Fermi-LAT is a pair-conversion detector for gamma-rays with an energy range from 20 MeV to 300 GeV and has an unprecedented resolution and sensitivity.

  5. The cell agglutination agent, phytohemagglutinin-L, improves the efficiency of somatic nuclear transfer cloning in cattle (Bos taurus).

    PubMed

    Du, Fuliang; Shen, Perng-Chih; Xu, Jie; Sung, Li-Ying; Jeong, B-Seon; Lucky Nedambale, Tshimangadzo; Riesen, John; Cindy Tian, X; Cheng, Winston T K; Lee, Shan-Nan; Yang, Xiangzhong

    2006-02-01

    One of the several factors that contribute to the low efficiency of mammalian somatic cloning is poor fusion between the small somatic donor cell and the large recipient oocyte. This study was designed to test phytohemagglutinin (PHA) agglutination activity on fusion rate, and subsequent developmental potential of cloned bovine embryos. The toxicity of PHA was established by examining its effects on the development of parthenogenetic bovine oocytes treated with different doses (Experiment 1), and for different durations (Experiment 2). The effective dose and duration of PHA treatment (150 microg/mL, 20 min incubation) was selected and used to compare membrane fusion efficiency and embryo development following somatic cell nuclear transfer (Experiment 3). Cloning with somatic donor fibroblasts versus cumulus cells was also compared, both with and without PHA treatment (150 microg/mL, 20 min). Fusion rate of nuclear donor fibroblasts, after phytohemagglutinin treatment, was increased from 33 to 61% (P < 0.05), and from 59 to 88% (P < 0.05) with cumulus cell nuclear donors. The nuclear transfer (NT) efficiency per oocyte used was improved following PHA treatment, for both fibroblast (13% versus 22%) as well as cumulus cells (17% versus 34%; P < 0.05). The cloned embryos, both with and without PHA treatment, were subjected to vitrification and embryo transfer testing, and resulted in similar survival (approximately 90% hatching) and pregnancy rates (17-25%). Three calves were born following vitrification and embryo transfer of these embryos; two from the PHA-treated group, and one from non-PHA control group. We concluded that PHA treatment significantly improved the fusion efficiency of somatic NT in cattle, and therefore, increased the development of cloned blastocysts. Furthermore, within a determined range of dose and duration, PHA had no detrimental effect on embryo survival post-vitrification, nor on pregnancy or calving rates following embryo transfer.

  6. New genetic variants of LATS1 detected in urinary bladder and colon cancer.

    PubMed

    Saadeldin, Mona K; Shawer, Heba; Mostafa, Ahmed; Kassem, Neemat M; Amleh, Asma; Siam, Rania

    2014-01-01

    LATS1, the large tumor suppressor 1 gene, encodes for a serine/threonine kinase protein and is implicated in cell cycle progression. LATS1 is down-regulated in various human cancers, such as breast cancer, and astrocytoma. Point mutations in LATS1 were reported in human sarcomas. Additionally, loss of heterozygosity of LATS1 chromosomal region predisposes to breast, ovarian, and cervical tumors. In the current study, we investigated LATS1 genetic variations including single nucleotide polymorphisms (SNPs), in 28 Egyptian patients with either urinary bladder or colon cancers. The LATS1 gene was amplified and sequenced and the expression of LATS1 at the RNA level was assessed in 12 urinary bladder cancer samples. We report, the identification of a total of 29 variants including previously identified SNPs within LATS1 coding and non-coding sequences. A total of 18 variants were novel. Majority of the novel variants, 13, were mapped to intronic sequences and un-translated regions of the gene. Four of the five novel variants located in the coding region of the gene, represented missense mutations within the serine/threonine kinase catalytic domain. Interestingly, LATS1 RNA steady state levels was lost in urinary bladder cancerous tissue harboring four specific SNPs (16045 + 41736 + 34614 + 56177) positioned in the 5'UTR, intron 6, and two silent mutations within exon 4 and exon 8, respectively. This study identifies novel single-base-sequence alterations in the LATS1 gene. These newly identified variants could potentially be used as novel diagnostic or prognostic tools in cancer.

  7. New genetic variants of LATS1 detected in urinary bladder and colon cancer

    PubMed Central

    Saadeldin, Mona K.; Shawer, Heba; Mostafa, Ahmed; Kassem, Neemat M.; Amleh, Asma; Siam, Rania

    2015-01-01

    LATS1, the large tumor suppressor 1 gene, encodes for a serine/threonine kinase protein and is implicated in cell cycle progression. LATS1 is down-regulated in various human cancers, such as breast cancer, and astrocytoma. Point mutations in LATS1 were reported in human sarcomas. Additionally, loss of heterozygosity of LATS1 chromosomal region predisposes to breast, ovarian, and cervical tumors. In the current study, we investigated LATS1 genetic variations including single nucleotide polymorphisms (SNPs), in 28 Egyptian patients with either urinary bladder or colon cancers. The LATS1 gene was amplified and sequenced and the expression of LATS1 at the RNA level was assessed in 12 urinary bladder cancer samples. We report, the identification of a total of 29 variants including previously identified SNPs within LATS1 coding and non-coding sequences. A total of 18 variants were novel. Majority of the novel variants, 13, were mapped to intronic sequences and un-translated regions of the gene. Four of the five novel variants located in the coding region of the gene, represented missense mutations within the serine/threonine kinase catalytic domain. Interestingly, LATS1 RNA steady state levels was lost in urinary bladder cancerous tissue harboring four specific SNPs (16045 + 41736 + 34614 + 56177) positioned in the 5′UTR, intron 6, and two silent mutations within exon 4 and exon 8, respectively. This study identifies novel single-base-sequence alterations in the LATS1 gene. These newly identified variants could potentially be used as novel diagnostic or prognostic tools in cancer. PMID:25628642

  8. Quick serological detection of a cancer biomarker with an agglutinated supramolecular glycoprobe.

    PubMed

    He, Xiao-Peng; Hu, Xi-Le; Jin, Hong-Ying; Gan, Jiemin; Zhu, Huili; Li, Jia; Long, Yi-Tao; Tian, He

    2015-09-01

    While serology represents the forefront technique for cancer diagnosis, current clinical methods for the detection of serum biomarkers have flaws in terms of the need of complicated manipulations, long analytical time, and high cost. Here, we develop a supramolecular glycoprobe for the quick serological detection of a cancer biomarker. The probe formed by agglutination between self-assembled glyco-gold nanoparticles and a lectin shows subtle optical variations upon the competitive recognition of a glycoprotein biomarker secreted by cancer cells, tumor-bearing mice, as well as clinical cancer patients, with no response to a series of controls including the serum of hepatitis patients. This research provides an insight into the development of effective tools for serological diagnosis of cancer.

  9. Cflec-5, a pattern recognition receptor in scallop Chlamys farreri agglutinating yeast Pichia pastoris.

    PubMed

    Zhang, Huan; Kong, Pengfei; Wang, Lingling; Zhou, Zhi; Yang, Jialong; Zhang, Ying; Qiu, Limei; Song, Linsheng

    2010-07-01

    C-type lectins are a superfamily of carbohydrate-recognition proteins which play crucial roles as pattern recognition receptors (PRRs) in the innate immunity. In this study, the full-length cDNA of a C-type lectin was cloned from scallop Chlamys farreri (designated as Cflec-5) by expression sequence tag (EST) analysis and rapid amplification of cDNA ends (RACE) approach. The full-length cDNA of Cflec-5 was of 1412 bp. The open reading frame encoded a polypeptide of 153 amino acids, including a signal sequence and a conserved carbohydrate-recognition domain with the EPN motif determining the mannose-binding specificity. The deduced amino acid sequence of Cflec-5 showed high similarity to members of C-type lectin superfamily. The quantitative real-time PCR was performed to investigate the tissue distribution of Cflec-5 mRNA and its temporal expression profiles in hemocytes post pathogen-associated molecular patterns (PAMPs) stimulation. In healthy scallops, the Cflec-5 mRNA was mainly detected in gill and mantle, and marginally in other tissues. The mRNA expression of Cflec-5 could be significantly induced by lipopolysaccharide (LPS) and glucan stimulation and reached the maximum level at 6 h and 12 h, respectively. But its expression level did not change significantly during peptidoglycan (PGN) stimulation. The function of Cflec-5 was investigated by recombination and expression of the cDNA fragment encoding its mature peptide in Escherichia coli Rosetta Gami (DE3). The recombinant Cflec-5 agglutinated Pichia pastoris in a calcium-independent way. The agglutinating activity could be inhibited by d-mannose, LPS and glucan, but not by d-galactose or PGN. These results collectively suggested that Cflec-5 was involved in the innate immune response of scallops and might contribute to nonself-recognition through its interaction with various PAMPs. PMID:20211738

  10. Oncogenicity of L-type amino-acid transporter 1 (LAT1) revealed by targeted gene disruption in chicken DT40 cells: LAT1 is a promising molecular target for human cancer therapy

    SciTech Connect

    Ohkawa, Mayumi; Ohno, Yoshiya; Masuko, Kazue; Takeuchi, Akiko; Suda, Kentaro; Kubo, Akihiro; Kawahara, Rieko; Okazaki, Shogo; Tanaka, Toshiyuki; Saya, Hideyuki; Seki, Masayuki; Enomoto, Takemi; Yagi, Hideki; Hashimoto, Yoshiyuki; Masuko, Takashi

    2011-03-25

    Highlights: {yields} We established LAT1 amino-acid transporter-disrupted DT40 cells. {yields} LAT1-disrupted cells showed slow growth and lost the oncogenicity. {yields} siRNA and mAb inhibited human tumor growth in vitro and in vivo. {yields} LAT1 is a promising target molecule for cancer therapy. -- Abstract: L-type amino-acid transporter 1 (LAT1) is the first identified light chain of CD98 molecule, disulfide-linked to a heavy chain of CD98. Following cDNA cloning of chicken full-length LAT1, we have constructed targeting vectors for the disruption of chicken LAT1 gene from genomic DNA of chicken LAT1 consisting of 5.4 kb. We established five homozygous LAT1-disrupted (LAT1{sup -/-}) cell clones, derived from a heterozygous LAT1{sup +/-} clone of DT40 chicken B cell line. Reactivity of anti-chicken CD98hc monoclonal antibody (mAb) with LAT1{sup -/-} DT40 cells was markedly decreased compared with that of wild-type DT40 cells. All LAT1{sup -/-} cells were deficient in L-type amino-acid transporting activity, although alternative-splice variant but not full-length mRNA of LAT1 was detected in these cells. LAT1{sup -/-} DT40 clones showed outstandingly slow growth in liquid culture and decreased colony-formation capacity in soft agar compared with wild-type DT40 cells. Cell-cycle analyses indicated that LAT1{sup -/-} DT40 clones have prolonged cell-cycle phases compared with wild-type or LAT1{sup +/-} DT40 cells. Knockdown of human LAT1 by small interfering RNAs resulted in marked in vitro cell-growth inhibition of human cancer cells, and in vivo tumor growth of HeLa cells in athymic mice was significantly inhibited by anti-human LAT1 mAb. All these results indicate essential roles of LAT1 in the cell proliferation and occurrence of malignant phenotypes and that LAT1 is a promising candidate as a molecular target of human cancer therapy.

  11. Study of agglutination of mouse mammary carcinoma (FM3A) cell induced by egg agglutinin of Rana catesbiana. II. Phytohemagglutinin P and protamine.

    PubMed

    Takeda, S; Kubota, K; Endo, Y; Matsuzawa, T

    1981-01-01

    When mouse mammary carcinoma (FM3A) cells were treated with egg agglutinin of Rana catesbiana for 15 min at 25 degrees C, percent total particle number of both cell aggregates and single cells was in direct proportion to the cell electrophoretic mobility. Phytohemagglutinin P mediated agglutination proceeded with biphasic kinetics: the higher the concentration of phytohemagglutinin P the shorter was the lag period between the first and second stages of agglutination. In protamine-mediated agglutination, the percent total particle number was reduced at low concentrations, while the electrophoretic mobility reduced only at high concentrations. Agglutinating and cytotoxic activities of these three reagents were in an intimate relation: the higher the agglutinating activity, the greater was their cytotoxic activity. PMID:6969671

  12. Agglutination of Histoplasma capsulatum by IgG monoclonal antibodies against Hsp60 impacts macrophage effector functions.

    PubMed

    Guimarães, Allan Jefferson; Frases, Susana; Pontes, Bruno; de Cerqueira, Mariana Duarte; Rodrigues, Marcio L; Viana, Nathan Bessa; Nimrichter, Leonardo; Nosanchuk, Joshua Daniel

    2011-02-01

    Histoplasma capsulatum can efficiently survive within macrophages, facilitating H. capsulatum translocation from the lung into the lymphatics and bloodstream. We have recently generated monoclonal antibodies (MAbs) to an H. capsulatum surface-expressed heat shock protein of 60 kDa (Hsp60) that modify disease in a murine histoplasmosis model. Interestingly, the MAbs induced different degrees of yeast cell agglutination in vitro. In the present study, we characterized the agglutination effects of the antibodies to Hsp60 on H. capsulatum yeast cells by light microscopy, flow cytometry, dynamic light scattering, measuring zeta potential, and using optical tweezers. We found that immunoglobulin Gs (IgGs) to Hsp60 cause H. capsulatum aggregation dependent on the (i) concentration of MAbs, (ii) MAb binding constant, and (iii) IgG subclass. Furthermore, infection of macrophages using agglutinates of various sizes after incubation with different Hsp60-binding MAbs induced association to macrophages through distinct cellular receptors and differentially affected macrophage antifungal functions. Hence, the capacity of IgG MAbs to agglutinate H. capsulatum significantly impacted pathogenic mechanisms of H. capsulatum during macrophage infection, and the effect was dependent on the antibody subclass and antigen epitope.

  13. Agglutination of Histoplasma capsulatum by IgG Monoclonal Antibodies against Hsp60 Impacts Macrophage Effector Functions▿

    PubMed Central

    Guimarães, Allan Jefferson; Frases, Susana; Pontes, Bruno; de Cerqueira, Mariana Duarte; Rodrigues, Marcio L.; Viana, Nathan Bessa; Nimrichter, Leonardo; Nosanchuk, Joshua Daniel

    2011-01-01

    Histoplasma capsulatum can efficiently survive within macrophages, facilitating H. capsulatum translocation from the lung into the lymphatics and bloodstream. We have recently generated monoclonal antibodies (MAbs) to an H. capsulatum surface-expressed heat shock protein of 60 kDa (Hsp60) that modify disease in a murine histoplasmosis model. Interestingly, the MAbs induced different degrees of yeast cell agglutination in vitro. In the present study, we characterized the agglutination effects of the antibodies to Hsp60 on H. capsulatum yeast cells by light microscopy, flow cytometry, dynamic light scattering, measuring zeta potential, and using optical tweezers. We found that immunoglobulin Gs (IgGs) to Hsp60 cause H. capsulatum aggregation dependent on the (i) concentration of MAbs, (ii) MAb binding constant, and (iii) IgG subclass. Furthermore, infection of macrophages using agglutinates of various sizes after incubation with different Hsp60-binding MAbs induced association to macrophages through distinct cellular receptors and differentially affected macrophage antifungal functions. Hence, the capacity of IgG MAbs to agglutinate H. capsulatum significantly impacted pathogenic mechanisms of H. capsulatum during macrophage infection, and the effect was dependent on the antibody subclass and antigen epitope. PMID:21134968

  14. Modeling of Virion Collisions in Cervicovaginal Mucus Reveals Limits on Agglutination as the Protective Mechanism of Secretory Immunoglobulin A

    PubMed Central

    Chen, Alex; McKinley, Scott A.; Shi, Feng; Wang, Simi; Mucha, Peter J.; Harit, Dimple; Forest, M. Gregory; Lai, Samuel K.

    2015-01-01

    Secretory immunoglobulin A (sIgA), a dimeric antibody found in high quantities in the gastrointestinal mucosa, is broadly associated with mucosal immune protection. A distinguishing feature of sIgA is its ability to crosslink pathogens, thereby creating pathogen/sIgA aggregates that are too large to traverse the dense matrix of mucin fibers in mucus layers overlying epithelial cells and consequently reducing infectivity. Here, we use modeling to investigate this mechanism of “immune exclusion” based on sIgA-mediated agglutination, in particular the potential use of sIgA to agglutinate HIV in cervicovaginal mucus (CVM) and prevent HIV transmission. Utilizing reported data on HIV diffusion in CVM and semen, we simulate HIV collision kinetics in physiologically-thick mucus layers–a necessary first step for sIgA-induced aggregation. We find that even at the median HIV load in semen of acutely infected individuals possessing high viral titers, over 99% of HIV virions will penetrate CVM and reach the vaginal epithelium without colliding with another virion. These findings imply that agglutination is unlikely to be the dominant mechanism of sIgA-mediated protection against HIV or other sexually transmitted pathogens. Rather, we surmise that agglutination is most effective against pathogens either present at exceedingly high concentrations or that possess motility mechanisms other than Brownian diffusion that significantly enhance encounter rates. PMID:26132216

  15. Boronophenylalanine, a boron delivery agent for boron neutron capture therapy, is transported by ATB0,+, LAT1 and LAT2

    PubMed Central

    Wongthai, Printip; Hagiwara, Kohei; Miyoshi, Yurika; Wiriyasermkul, Pattama; Wei, Ling; Ohgaki, Ryuichi; Kato, Itsuro; Hamase, Kenji; Nagamori, Shushi; Kanai, Yoshikatsu

    2015-01-01

    The efficacy of boron neutron capture therapy relies on the selective delivery of boron carriers to malignant cells. p-Boronophenylalanine (BPA), a boron delivery agent, has been proposed to be localized to cells through transporter-mediated mechanisms. In this study, we screened aromatic amino acid transporters to identify BPA transporters. Human aromatic amino acid transporters were functionally expressed in Xenopus oocytes and examined for BPA uptake and kinetic parameters. The roles of the transporters in BPA uptake were characterized in cancer cell lines. For the quantitative assessment of BPA uptake, HPLC was used throughout the study. Among aromatic amino acid transporters, ATB0,+, LAT1 and LAT2 were found to transport BPA with Km values of 137.4 ± 11.7, 20.3 ± 0.8 and 88.3 ± 5.6 μM, respectively. Uptake experiments in cancer cell lines revealed that the LAT1 protein amount was the major determinant of BPA uptake at 100 μM, whereas the contribution of ATB0,+ became significant at 1000 μM, accounting for 20–25% of the total BPA uptake in MCF-7 breast cancer cells. ATB0,+, LAT1 and LAT2 transport BPA at affinities comparable with their endogenous substrates, suggesting that they could mediate effective BPA uptake in vivo. The high and low affinities of LAT1 and ATB0,+, respectively, differentiate their roles in BPA uptake. ATB0,+, as well as LAT1, could contribute significantly to the tumor accumulation of BPA at clinical dose. PMID:25580517

  16. A low cost and high throughput magnetic bead-based immuno-agglutination assay in confined droplets.

    PubMed

    Teste, Bruno; Ali-Cherif, Anaïs; Viovy, Jean Louis; Malaquin, Laurent

    2013-06-21

    Although passive immuno-agglutination assays consist of one step and simple procedures, they are usually not adapted for high throughput analyses and they require expensive and bulky equipment for quantitation steps. Here we demonstrate a low cost, multimodal and high throughput immuno-agglutination assay that relies on a combination of magnetic beads (MBs), droplets microfluidics and magnetic tweezers. Antibody coated MBs were used as a capture support in the homogeneous phase. Following the immune interaction, water in oil droplets containing MBs and analytes were generated and transported in Teflon tubing. When passing in between magnetic tweezers, the MBs contained in the droplets were magnetically confined in order to enhance the agglutination rate and kinetics. When releasing the magnetic field, the internal recirculation flows in the droplet induce shear forces that favor MBs redispersion. In the presence of the analyte, the system preserves specific interactions and MBs stay in the aggregated state while in the case of a non-specific analyte, redispersion of particles occurs. The analyte quantitation procedure relies on the MBs redispersion rate within the droplet. The influence of different parameters such as magnetic field intensity, flow rate and MBs concentration on the agglutination performances have been investigated and optimized. Although the immuno-agglutination assay described in this work may not compete with enzyme linked immunosorbent assay (ELISA) in terms of sensitivity, it offers major advantages regarding the reagents consumption (analysis is performed in sub microliter droplet) and the platform cost that yields to very cheap analyses. Moreover the fully automated analysis procedure provides reproducible analyses with throughput well above those of existing technologies. We demonstrated the detection of biotinylated phosphatase alkaline in 100 nL sample volumes with an analysis rate of 300 assays per hour and a limit of detection of 100 pM.

  17. Changing Horses in Midstream: Fermi LAT Computing and SCons

    NASA Astrophysics Data System (ADS)

    Bogart, J. R.; Golpayegani, N.

    2011-07-01

    (For the Fermi LAT Collaboration) Several years into GLAST (now Fermi) offline software development it became evident we would need a replacement for our original build system, the Configuration Management Tool (CMT) developed at CERN, in order to support Mac users and to keep pace with newer compilers and operating system versions on our traditional platforms, Linux and Windows. The open source product SCons emerged as the only viable alternative and development began in earnest several months before Fermi's successful launch in June of 2008. Over two years later the conversion is nearing completion. This paper describes the conversion to and our use of SCons, concentrating on the resulting environment for users and developers and how it was achieved. Topics discussed include SCons and its interaction with Fermi code, GoGui, a cross-platform gui for Fermi developers, and issues specific to Windows developer support.

  18. Cerebral cortex hyperthyroidism of newborn mct8-deficient mice transiently suppressed by lat2 inactivation.

    PubMed

    Núñez, Bárbara; Martínez de Mena, Raquel; Obregon, Maria Jesus; Font-Llitjós, Mariona; Nunes, Virginia; Palacín, Manuel; Dumitrescu, Alexandra M; Morte, Beatriz; Bernal, Juan

    2014-01-01

    Thyroid hormone entry into cells is facilitated by transmembrane transporters. Mutations of the specific thyroid hormone transporter, MCT8 (Monocarboxylate Transporter 8, SLC16A2) cause an X-linked syndrome of profound neurological impairment and altered thyroid function known as the Allan-Herndon-Dudley syndrome. MCT8 deficiency presumably results in failure of thyroid hormone to reach the neural target cells in adequate amounts to sustain normal brain development. However during the perinatal period the absence of Mct8 in mice induces a state of cerebral cortex hyperthyroidism, indicating increased brain access and/or retention of thyroid hormone. The contribution of other transporters to thyroid hormone metabolism and action, especially in the context of MCT8 deficiency is not clear. We have analyzed the role of the heterodimeric aminoacid transporter Lat2 (Slc7a8), in the presence or absence of Mct8, on thyroid hormone concentrations and on expression of thyroid hormone-dependent cerebral cortex genes. To this end we generated Lat2-/-, and Mct8-/yLat2-/- mice, to compare with wild type and Mct8-/y mice during postnatal development. As described previously the single Mct8 KO neonates had a transient increase of 3,5,3'-triiodothyronine concentration and expression of thyroid hormone target genes in the cerebral cortex. Strikingly the absence of Lat2 in the double Mct8Lat2 KO prevented the effect of Mct8 inactivation in newborns. The Lat2 effect was not observed from postnatal day 5 onwards. On postnatal day 21 the Mct8 KO displayed the typical pattern of thyroid hormone concentrations in plasma, decreased cortex 3,5,3'-triiodothyronine concentration and Hr expression, and concomitant Lat2 inactivation produced little to no modifications. As Lat2 is expressed in neurons and in the choroid plexus, the results support a role for Lat2 in the supply of thyroid hormone to the cerebral cortex during early postnatal development. PMID:24819605

  19. Differential Requirement for LAT and SLP-76 in GPVI versus T Cell Receptor Signaling

    PubMed Central

    Judd, Barbi A.; Myung, Peggy S.; Obergfell, Achim; Myers, Erin E.; Cheng, Alec M.; Watson, Stephen P.; Pear, Warren S.; Allman, David; Shattil, Sanford J.; Koretzky, Gary A.

    2002-01-01

    Mice deficient in the adaptor Src homology 2 domain-containing leukocyte phosphoprotein of 76 kD (SLP-76) exhibit a bleeding disorder and lack T cells. Linker for activation of T cells (LAT)-deficient mice exhibit a similar T cell phenotype, but show no signs of hemorrhage. Both SLP-76 and LAT are important for optimal platelet activation downstream of the collagen receptor, GPVI. In addition, SLP-76 is involved in signaling mediated by integrin αIIbβ3. Because SLP-76 and LAT function coordinately in T cell signal transduction, yet their roles appear to differ in hemostasis, we investigated in detail the functional consequences of SLP-76 and LAT deficiencies in platelets. Previously we have shown that LAT−/− platelets exhibit defective responses to the GPVI-specific agonist, collagen-related peptide (CRP). Consistent with this, we find that surface expression of P-selectin in response to high concentrations of GPVI ligands is reduced in both LAT- and SLP-76–deficient platelets. However, platelets from LAT−/− mice, but not SLP-76−/− mice, aggregate normally in response to high concentrations of collagen and convulxin. Additionally, unlike SLP-76, LAT is not tyrosine phosphorylated after fibrinogen binding to integrin αIIbβ3, and collagen-stimulated platelets deficient in LAT spread normally on fibrinogen-coated surfaces. Together, these findings indicate that while LAT and SLP-76 are equally required for signaling via the T cell antigen receptor (TCR) and pre-TCR, platelet activation downstream of GPVI and αIIbβ3 shows a much greater dependency on SLP-76 than LAT. PMID:11901197

  20. Cerebral cortex hyperthyroidism of newborn mct8-deficient mice transiently suppressed by lat2 inactivation.

    PubMed

    Núñez, Bárbara; Martínez de Mena, Raquel; Obregon, Maria Jesus; Font-Llitjós, Mariona; Nunes, Virginia; Palacín, Manuel; Dumitrescu, Alexandra M; Morte, Beatriz; Bernal, Juan

    2014-01-01

    Thyroid hormone entry into cells is facilitated by transmembrane transporters. Mutations of the specific thyroid hormone transporter, MCT8 (Monocarboxylate Transporter 8, SLC16A2) cause an X-linked syndrome of profound neurological impairment and altered thyroid function known as the Allan-Herndon-Dudley syndrome. MCT8 deficiency presumably results in failure of thyroid hormone to reach the neural target cells in adequate amounts to sustain normal brain development. However during the perinatal period the absence of Mct8 in mice induces a state of cerebral cortex hyperthyroidism, indicating increased brain access and/or retention of thyroid hormone. The contribution of other transporters to thyroid hormone metabolism and action, especially in the context of MCT8 deficiency is not clear. We have analyzed the role of the heterodimeric aminoacid transporter Lat2 (Slc7a8), in the presence or absence of Mct8, on thyroid hormone concentrations and on expression of thyroid hormone-dependent cerebral cortex genes. To this end we generated Lat2-/-, and Mct8-/yLat2-/- mice, to compare with wild type and Mct8-/y mice during postnatal development. As described previously the single Mct8 KO neonates had a transient increase of 3,5,3'-triiodothyronine concentration and expression of thyroid hormone target genes in the cerebral cortex. Strikingly the absence of Lat2 in the double Mct8Lat2 KO prevented the effect of Mct8 inactivation in newborns. The Lat2 effect was not observed from postnatal day 5 onwards. On postnatal day 21 the Mct8 KO displayed the typical pattern of thyroid hormone concentrations in plasma, decreased cortex 3,5,3'-triiodothyronine concentration and Hr expression, and concomitant Lat2 inactivation produced little to no modifications. As Lat2 is expressed in neurons and in the choroid plexus, the results support a role for Lat2 in the supply of thyroid hormone to the cerebral cortex during early postnatal development.

  1. Effect of Redox Balance Alterations on Cellular Localization of LAT and Downstream T-Cell Receptor Signaling Pathways

    PubMed Central

    Gringhuis, Sonja I.; Papendrecht-van der Voort, Ellen A. M.; Leow, Angela; Levarht, E. W. Nivine; Breedveld, Ferdinand C.; Verweij, Cornelis L.

    2002-01-01

    The integral membrane protein linker for activation of T cells (LAT) is a central adapter protein in the T-cell receptor (TCR)-mediated signaling pathways. The cellular localization of LAT is extremely sensitive to intracellular redox balance alterations. Reduced intracellular levels of the antioxidant glutathione (GSH), a hallmark of chronic oxidative stress, resulted in the membrane displacement of LAT, abrogated TCR-mediated signaling and consequently hyporesponsiveness of T lymphocytes. The membrane displacement of LAT is accompanied by a considerable difference in the mobility of LAT upon native and nonreducing denaturing polyacrylamide gel electrophoresis analysis, a finding indicative of a conformational change. Targeted mutation of redox-sensitive cysteine residues within LAT created LAT mutants which remain membrane anchored under conditions of chronic oxidative stress. The expression of redox-insensitive LAT mutants allows for restoration of TCR-mediated signal transduction, whereas CD28-mediated signaling pathways remained impaired. These results are indicative that the membrane displacement of LAT as a result of redox balance alterations is a consequence of a conformational change interfering with the insertion of LAT into the plasma membrane. Conclusively, the data suggest a role for LAT as a crucial intermediate in the sensitivity of TCR signaling and hence T lymphocytes toward chronic oxidative stress. PMID:11756537

  2. Stabilization of a prokaryotic LAT transporter by random mutagenesis.

    PubMed

    Rodríguez-Banqueri, Arturo; Errasti-Murugarren, Ekaitz; Bartoccioni, Paola; Kowalczyk, Lukasz; Perálvarez-Marín, Alex; Palacín, Manuel; Vázquez-Ibar, José Luis

    2016-04-01

    The knowledge of three-dimensional structures at atomic resolution of membrane transport proteins has improved considerably our understanding of their physiological roles and pathological implications. However, most structural biology techniques require an optimal candidate within a protein family for structural determination with (a) reasonable production in heterologous hosts and (b) good stability in detergent micelles. SteT, the Bacillus subtilis L-serine/L-threonine exchanger is the best-known prokaryotic paradigm of the mammalian L-amino acid transporter (LAT) family. Unfortunately, SteT's lousy stability after extracting from the membrane prevents its structural characterization. Here, we have used an approach based on random mutagenesis to engineer stability in SteT. Using a split GFP complementation assay as reporter of protein expression and membrane insertion, we created a library of 70 SteT mutants each containing random replacements of one or two residues situated in the transmembrane domains. Analysis of expression and monodispersity in detergent of this library permitted the identification of evolved versions of SteT with a significant increase in both expression yield and stability in detergent with respect to wild type. In addition, these experiments revealed a correlation between the yield of expression and the stability in detergent micelles. Finally, and based on protein delipidation and relipidation assays together with transport experiments, possible mechanisms of SteT stabilization are discussed. Besides optimizing a member of the LAT family for structural determination, our work proposes a new approach that can be used to optimize any membrane protein of interest. PMID:26976827

  3. Immunofluorescence, enzyme-linked immunosorbent assay, particle agglutination and western blot for the detection of antibody to human immunodeficiency virus type 1.

    PubMed

    Auwanit, W; Ayuthaya, P I; Balachandra, K; Jayavasu, C; Phanthumachinda, B; Ikuta, K; Yamanishi, K; Kanai, K

    1990-03-01

    Immunofluorescence assay (IFA) has been applied for detection of antibody to human immunodeficiency virus type 1 (HIV-1). To compare the IFA with an enzyme-linked immunosorbent assay (ELISA) and particle agglutination (PA), we examined the antibody response to HIV-1 in 475 sera from AIDS, PGL and ARC patients as well as several risk groups and healthy persons by three methods. The positive results by any methods were confirmed by western blot (WB). The results by all methods were well correlated on the sera from 45 asymptomatic male homosexuals and 70 female prostitutes. There were some false positive results by ELISA in the sera from prisoners and healthy persons. Four sera from drug abusers were positive only by PA and IFA and were negative by ELISA. All were WB-inconclusive. Particle agglutination and IFA results were compared with western blot analysis on 208 ELISA-positive sera. All IFA-strongly positive sera (84%) were positive by western blot. The sera with weakly positive, negative and inconclusive results by IFA (16%) were possibly any of positive, inconclusive or negative by western blot. By PA, 200 of 208 (97%) sera were PA-positive and 1% of these sera were WB-inconclusive while the PA-negative sera were either negative or inconclusive by western blot. These results suggested that PA is a simple and sensitive method for screening of HIV-1 antibody while IFA could be a primary confirmatory test and western blot would then be used for confirming any IFA-negative or inconclusive results.

  4. Searching for Dark Matter Signatures in the GLAST LAT Electron Flux

    NASA Technical Reports Server (NTRS)

    Moiseev, Alexander; Profumo, Stefano

    2008-01-01

    We explored several viable scenarios of how LAT might observe DM, when the spectral feature is predicted to be observed in the HE electron flux It has been demonstrated elsewhere that LAT will be capable to detect HE electrons flux in energy range from 20 GeV to - 1 TeV with 520% energy resolution and good statistics If there is a DM-caused feature in the HE electron flux (in the range 20 GeV - 1 TeV), LAT will be the best current instrument to observe it!

  5. NEW FERMI-LAT EVENT RECONSTRUCTION REVEALS MORE HIGH-ENERGY GAMMA RAYS FROM GAMMA-RAY BURSTS

    SciTech Connect

    Atwood, W. B.; Baldini, L.; Bregeon, J.; Pesce-Rollins, M.; Sgro, C.; Tinivella, M.; Bruel, P.; Cohen-Tanugi, J.; Granot, J.; Longo, F.; Razzaque, S.; Zimmer, S. E-mail: nicola.omodei@stanford.edu

    2013-09-01

    Based on the experience gained during the four and a half years of the mission, the Fermi-LAT Collaboration has undertaken a comprehensive revision of the event-level analysis going under the name of Pass 8. Although it is not yet finalized, we can test the improvements in the new event reconstruction with the special case of the prompt phase of bright gamma-ray bursts (GRBs), where the signal-to-noise ratio is large enough that loose selection cuts are sufficient to identify gamma rays associated with the source. Using the new event reconstruction, we have re-analyzed 10 GRBs previously detected by the Large Area Telescope (LAT) for which an X-ray/optical follow-up was possible and found four new gamma rays with energies greater than 10 GeV in addition to the seven previously known. Among these four is a 27.4 GeV gamma ray from GRB 080916C, which has a redshift of 4.35, thus making it the gamma ray with the highest intrinsic energy ({approx}147 GeV) detected from a GRB. We present here the salient aspects of the new event reconstruction and discuss the scientific implications of these new high-energy gamma rays, such as constraining extragalactic background light models, Lorentz invariance violation tests, the prompt emission mechanism, and the bulk Lorentz factor of the emitting region.

  6. Fermi-LAT Gamma-ray Bursts and Insight from Swift

    NASA Technical Reports Server (NTRS)

    Racusin, Judith L.

    2011-01-01

    A new revolution in GRB observation and theory has begun over the last 3 years since the launch of the Fermi gamma-ray space telescope. The new window into high energy gamma-rays opened by the Fermi-LAT is providing insight into prompt emission mechanisms and possibly also afterglow physics. The LAT detected GRBs appear to be a new unique subset of extremely energetic and bright bursts. In this talk I will discuss the context and recent discoveries from these LAT GRBs and the large database of broadband observations collected by Swift over the last 7 years and how through comparisons between the Swift, GBM, and LAT GRB samples, we can learn about the unique characteristics and relationships between each population.

  7. Transferable class C beta-lactamases in Escherichia coli strains isolated in Greek hospitals and characterization of two enzyme variants (LAT-3 and LAT-4) closely related to Citrobacter freundii AmpC beta-lactamase.

    PubMed

    Gazouli, M; Tzouvelekis, L S; Vatopoulos, A C; Tzelepi, E

    1998-10-01

    Among 2133 isolates of Escherichia coli obtained during 1996 from 10 Greek hospitals, 63 (3%) were resistant to cefoxitin. Typing by ERIC2-PCR indicated that the cefoxitin-resistant (FOXr) isolates were distinct. beta-Lactamase studies and hybridization experiments showed that most strains produced beta-lactamases related to the AmpC chromosomal cephalosporinase of Citrobacter freundii. The enzymes were encoded by similar non-self-transmissible plasmids. The bla genes encoding two beta-lactamases (LAT-3 and LAT-4) with isoelectric points 8.9 and 9.4, respectively, were cloned and sequenced. The deduced amino acid sequences displayed a high degree of homology (>95%) with the AmpC beta-lactamase of C. freundii. The patterns of resistance to beta-lactams of the FOXr E. coli depended on the quantity of class C enzymes and the simultaneous expression of other beta-lactamases. In a few isolates a 36 kDa outer-membrane protein, presumably a porin, was not expressed at detectable quantities. These isolates were resistant to cefoxitin, and their susceptibility to the other beta-lactams tested was not significantly decreased.

  8. ATel draft: Fermi LAT detection of a new Gamma-ray Source PKS 2247-131

    NASA Astrophysics Data System (ADS)

    Buson, S.

    2016-07-01

    The Large Area Telescope (LAT), on board the Fermi Gamma-ray Space Telescope, has observed strong gamma-ray emission from a source positionally consistent with the radio source PKS 2247-131 with coordinates RA=342.4983854 deg, Dec=-12.8546736 deg (J2000; Beasley et al. 2002, ApJS, 141, 13). This source is not in any published LAT catalog and was not detected by AGILE or EGRET.

  9. LATS2-mediated YAP1 phosphorylation is involved in HCC tumorigenesis

    PubMed Central

    Guo, Chao; Wang, Xintian; Liang, Lufeng

    2015-01-01

    YAP (yes-associated protein) is a transcriptional co-activator that acts downstream of the Hippo signaling pathway and regulates multiple cellular processes, including proliferation and apoptosis. Although YAP plays an important role in various tumors, the underlying mechanism in hepatocellular carcinoma (HCC) tumorigenesis remains unclear. In this study, we observed that the LATS2 was highly expressed in Bel-7402 and HepG2 cell lines, and LATS2 protein level was negatively correlated with YAP1 in HCC cells. And then, we inhibited LATS2 expression by transfecting with siRNA. Western blot and Immunofluorescent staining analysis demonstrated that LATS2 inhibition decreased the dephosphorylation of YAP1 protein and promoted YAP1 nuclear accumulation in HCC cells. Moreover, Immunoprecipitation assay results also indicated that Yap binds directly to TEAD2 and LATS2 inhibition-mediated dephosphorylation increased the YAP1/TEAD2 association, leading to YAP1/TEAD2 transcriptional activation, which in turn upregulated cell invasion in HCC cells. Taken together, our current data indicated a new regulatory mechanism of YAP1 by the LATS2-mediated phosphorylation that was involved in HCC tumorigenesis. PMID:25973055

  10. MicroRNA-181b promotes ovarian cancer cell growth and invasion by targeting LATS2

    SciTech Connect

    Xia, Ying; Gao, Yan

    2014-05-09

    Highlights: • miR-181b is upregulated in human ovarian cancer tissues. • miR-181b promotes ovarian cancer cell proliferation and invasion. • LATS2 is a direct target of miR-181b. • LATS2 is involved in miR-181b-induced ovarian cancer cell growth and invasion. - Abstract: MicroRNAs (miRNAs) are strongly implicated in tumorigenesis and metastasis. In this study, we showed significant upregulation of miR-181b in ovarian cancer tissues, compared with the normal ovarian counterparts. Forced expression of miR-181b led to remarkably enhanced proliferation and invasion of ovarian cancer cells while its knockdown induced significant suppression of these cellular events. The tumor suppressor gene, LATS2 (large tumor suppressor 2), was further identified as a novel direct target of miR-181b. Specifically, miR-181b bound directly to the 3′-untranslated region (UTR) of LATS2 and suppressed its expression. Restoration of LATS2 expression partially reversed the oncogenic effects of miR-181b. Our results indicate that miR-181b promotes proliferation and invasion by targeting LATS2 in ovarian cancer cells. These findings support the utility of miR-181b as a potential diagnostic and therapeutic target for ovarian cancer.

  11. An acousto-optical method for registration of erythrocytes' agglutination reaction—sera color influence on the resolving power

    NASA Astrophysics Data System (ADS)

    Doubrovski, V. A.; Medvedeva, M. F.; Torbin, S. O.

    2016-01-01

    The absorption spectra of agglutinating sera were used to determine blood groups. It was shown experimentally that the sera color significantly affects the resolving power of the acousto-optical method of blood typing. In order to increase the resolving power of the method and produce an invariance of the method for sera color, we suggested introducing a probing light beam individually for different sera. The proposed technique not only improves the resolving power of the method, but also reduces the risk of false interpretation of the experimental results and, hence, error in determining the blood group of the sample. The latter is especially important for the typing of blood samples with weak agglutination of erythrocytes. This study can be used in the development of an instrument for instrumental human blood group typing based on the acousto-optical method.

  12. [Evaluation of a latex agglutination assay method for the determination of plasmin/alpha 2 plasmin inhibitor complex].

    PubMed

    Murakami, F; Iijima, K; Nakamura, K; Ikawa, S

    1994-06-01

    We evaluated a latex agglutination assay method for concentration of plasmin/alpha 2 plasmin inhibitor complex (PPI) developed recently. The latex reagent consisted of two kinds of latex particles, one was coated with monoclonal antibody against plasmin (JIPPI-3) and another coated with monoclonal antibody against modified alpha 2 plasmin inhibitor (JIPPI-50). A correlation of concentrations of PPI between this method and ordinary EIA kit was very good (r = 0.969). Within-run precision of latex agglutination reagent also was good. The concentrations of PPI in plasmas of 40 in 43 normal subjects were 0-0.8 microgram/ml and others were 0.8-1.6 microgram/ml. Plasma levels of PPI were markedly elevated in patients with DIC. In addition, half of the patients with malignant tumors or liver diseases had increased levels of PPI. 16 of 32 cases with selected diseases (18 malignant tumors, 4 liver diseases, 2 infectious diseases, 2 cerebral contusions, 6 others) showed abnormal levels in PPI (> or = 0.8 microgram/ml) during several days preceding the elevation of FDP. It suggested that PPI could reflect fibrinolysis earlier than FDP. This latex agglutination assay is a simple and rapid method, and specific for the determination of PPI concentration as well as EIA method. We conclude that this assay method is very convenient for clinical use. PMID:8051804

  13. Detection of heat-stable antigens of Campylobacter jejuni and C. coli by direct agglutination and passive hemagglutination.

    PubMed

    Oza, A N; Thwaites, R T; Wareing, D R A; Bolton, F J; Frost, J A

    2002-03-01

    The two serotyping schemes for the detection of heat-stable antigens of Campylobacter jejuni and Campylobacter coli use the same strains for antiserum production but differ in the detection systems used for identifying agglutination. The Penner method uses passive hemagglutination (PHA) while the Laboratory of Enteric Pathogens method uses the same antisera but in a whole-bacterial-cell direct agglutination (DA) protocol. C. jejuni produces a polysaccharide capsule, which is antigenic, and is the main component detected by the PHA method. The DA method will detect both capsule antigens and lipopolysaccharide (LPS) or lipooligosaccharide (LOS) surface antigens. Comparison of both methods by using a selection of isolates from human infection has shown a range of variation in agglutination specificity, reflecting the differences in antigens detected by the two methods. While 27.4% of the 416 C. jejuni isolates reacted with the antisera raised against the same type strains by either method, the majority showed a range of more complex relationships. None of the 37 C. coli isolates reacted with the same antiserum by both methods. Together the two schemes gave a total of 102 distinct combined serogroups for C. jejuni and 16 for C. coli. Thus, while some clonally related isolates share the same capsule and LOS or LPS antigens, other strains appear to have a common capsule antigen but differ in their LPS or LOS structures or vice versa.

  14. Agglutinating Activity and Structural Characterization of Scalarin, the Major Egg Protein of the Snail Pomacea scalaris (d’Orbigny, 1832)

    PubMed Central

    Ituarte, Santiago; Dreon, Marcos Sebastián; Ceolin, Marcelo; Heras, Horacio

    2012-01-01

    Apple snail perivitellins are emerging as ecologically important reproductive proteins. To elucidate if the protective functions of the egg proteins of Pomacea canaliculata (Caenogastropoda, Ampullariidae), involved in embryo defenses, are present in other Pomacea species we studied scalarin (PsSC), the major perivitellin of Pomacea scalaris. Using small angle X-ray scattering, fluorescence and absorption spectroscopy and biochemical methods, we analyzed PsSC structural stability, agglutinating activity, sugar specificity and protease resistance. PsSC aggluttinated rabbit, and, to a lesser extent, human B and A erythrocytes independently of divalent metals Ca2+ and Mg2+ were strongly inhibited by galactosamine and glucosamine. The protein was structurally stable between pH 2.0 to 10.0, though agglutination occurred only between pH 4.0 to 8.0 (maximum activity at pH 7.0). The agglutinating activity was conserved up to 60°C and completely lost above 80°C, in agreement with the structural thermal stability of the protein (up to 60°C). PsSC was able to withstand in vitro gastrointestinal digestion, and showed no trypsin inhibition activity. The presence of lectin activity has been reported in eggs of other Pomacea snails, but here we link for the first time, this activity to an apple snail multifunctional perivitellin. This novel role for a snail egg storage protein is different from closely related P.canaliculata defensive proteins. PMID:23185551

  15. The Fermi-LAT view of the colliding wind binaries

    NASA Astrophysics Data System (ADS)

    Pshirkov, M. S.

    2016-03-01

    Colliding wind binaries (CWBs) have been considered as a possible high-energy γ-ray sources for some time, however no system other than η Car has been detected. In the Letter, a sample of seven CWBs (WR 11, WR 70, WR 137, WR 140, WR 146, WR 147) which, by means of theoretic modelling, were deemed most promising candidates, was analysed using almost 7 yr of the Fermi-Large Area Telescope (LAT) data. WR 11 (γ2 Vel) was detected at 6.1σ confidence level with a photon flux in 0.1-100 GeV range (1.8 ± 0.6) × 10-9 ph cm-2 s-1 and an energy flux (2.7 ± 0.5) × 10-12 erg cm-2 s-1. At the adopted distance d = 340 pc this corresponds to a luminosity L = (3.7 ± 0.7) × 1031 erg s-1. This luminosity amounts to ˜6 × 10-6 fraction of the total wind kinetic power and ˜1.6 × 10-4 fraction of the power injected into the wind-wind interaction region of this system. Upper limits were set on the high energy flux from the WR 70 and WR 140 systems.

  16. Fermi-LAT Observation of Supernova Remnant S147

    SciTech Connect

    Katsuta, J.; Uchiyama, Y.; Tanaka, T.; Tajima, H.; Bechtol, K.; Funk, S.; Lande, J.; Ballet, J.; Hanabata, Y.; Lemoine-Goumard, M.; Takahashi, T.; /JAXA, Sagamihara

    2012-08-17

    We present an analysis of gamma-ray data obtained with the Large Area Telescope (LAT) onboard the Fermi Gamma-ray Space Telescope in the region around SNR S147 (G180.0-1.7). A spatially extended gamma-ray source detected in an energy range of 0.2-10 GeV is found to coincide with SNR S147. We confirm its spatial extension at >5{sigma} confidence level. The gamma-ray flux is (3.8 {+-} 0.6) x 10{sup -8} photons cm{sup -2} s{sup -1}, corresponding to a luminosity of 1.3 x 10{sup 34} (d/1.3 kpc){sup 2} erg s{sup -1} in this energy range. The gamma-ray emission exhibits a possible spatial correlation with prominent H{alpha} filaments of S147. There is no indication that the gamma-ray emission comes from the associated pulsar PSR J0538+2817. The gamma-ray spectrum integrated over the remnant is likely dominated by the decay of neutral {pi} mesons produced through the proton-proton collisions in the filaments. Reacceleration of pre-existing CRs and subsequent adiabatic compression in the filaments is sufficient to provide the required energy density of high-energy protons.

  17. Fermi LAT Observation of Centaurus a Radio Galaxy

    NASA Astrophysics Data System (ADS)

    Sahakyan, N. V.

    2013-01-01

    The results of analysis of approximately 3 year gamma-ray observations (August 2008-July 2011) of the core of radio galaxy Centaurus A with the Fermi Large Area Telescope (Fermi LAT) are presented. Binned likelihood analysis method applying to the data shows that below several GeV the spectrum can be described by a single power-law with photon index Γ = 2.73 ± 0.06. However, at higher energies the new data show significant excess above the extrapolation of the energy spectrum from low energies. The comparison of the corresponding Spectral Energy Distribution (SED) at GeV energies with the SED in the TeV energy band reported by the H.E.S.S. collaboration shows that we deal with two or perhaps even three components of gamma-radiation originating from different regions located within the central 10 kpc of Centaurus A. The analysis of gamma-ray data of Centaurus A lobe accumulated from the beginning of the operation until November 14, 2011 show extension of the HE gamma-ray emission beyond the WMAP radio image in the case of the Northern lobe [9]. The possible origins of gamma-rays from giant radio lobes of Centaurus A are discussed in the context of hadronic and leptonic scenarios.

  18. Solar System Gamma Ray observations using Fermi-LAT detector

    SciTech Connect

    Giglietto, N.

    2009-04-08

    The Fermi Gamma-ray Space Telescope, launched in June 2008, is an international space mission dedicated to the study of the high-energy gamma rays from the Universe. The main instrument aboard Fermi is the Large Area Telescope (LAT), a pair conversion telescope equipped with the state-of-the art in gamma-ray detectors technology, and operating at energies >30 MeV. During first two months of data taking, Fermi has detected high-energy gamma rays from the quiet Sun and the Moon. This emission is produced by interactions of cosmic rays; by nucleons with the solar and lunar surface, and electrons with solar photons in the heliosphere. While the Moon was detected by EGRET on CGRO with low statistics, Fermi provides high-sensitivity measurements on a daily basis allowing both short- and long-term variability to be studied. Since Galactic cosmic rays are at their maximum flux at solar minimum we expect that the quiescent solar and lunar emission to be a maximum during the period covered by this report. Fermi is the only mission capable of monitoring the Sun at energies above several hundred MeV over the full 24th solar cycle. We present first analysis showing images of Moon and the quiet emission of the solar disk, giving a description of the analysis tools used.

  19. Three Millisecond Pulsars in Fermi LAT Unassociated Bright Sources

    NASA Technical Reports Server (NTRS)

    Ransom, S. M.; Ray, P. S.; Camilo, F.; Roberts, M. S. E.; Celik, O.; Wolff, M. T.; Cheung, C. C.; Kerr, M.; Pennucci, T.; DeCesar, M. E.; Cognard, I.; Lyne, A. G.; Stappers, B. W.; Freire, P. C. C.; Grove, J. E.; Abdo, A. A.; Desvignes, G.; Donato, D.; Ferrara, E. C.; Gehrels, N.; Guillemot, L.; Gwon, C.; Johnston, S.; Harding, A. K.; Thompson, D. J.

    2010-01-01

    We searched for radio pulsars in 25 of the non-variable, unassociated sources in the Fermi LAT Bright Source List with the Green Bank Telescope at 820 MHz. We report the discovery of three radio and gamma-ray millisecond pulsar (MSPs) from a high Galactic latitude subset of these sources. All of the pulsars are in binary systems, which would have made them virtually impossible to detect in blind gamma-ray pulsation searches. They seem to be relatively normal, nearby (<= 2 kpc) MSPs. These observations, in combination with the Fermi detection of gamma-rays from other known radio MSPs, imply that most, if not all, radio MSPs are efficient gamma-ray producers. The gamma-ray spectra of the pulsars are power law in nature with exponential cutoffs at a few Ge V, as has been found with most other pulsars. The MSPs have all been detected as X-ray point sources. Their soft X-ray luminosities of approx 10(exp 30) - 10(exp 31) erg/s are typical of the rare radio MSPs seen in X-rays.

  20. THREE MILLISECOND PULSARS IN FERMI LAT UNASSOCIATED BRIGHT SOURCES

    SciTech Connect

    Ransom, S. M.; Ray, P. S.; Wolff, M. T.; Grove, J. E.; Camilo, F.; Roberts, M. S. E.; Celik, Oe.; DeCesar, M. E.; Ferrara, E. C.; Gehrels, N.; Cheung, C. C.; Abdo, A. A.; Kerr, M.; Pennucci, T.; Cognard, I.; Freire, P. C. C.; Desvignes, G.; Donato, D. E-mail: Paul.Ray@nrl.navy.mil

    2011-01-20

    We searched for radio pulsars in 25 of the non-variable, unassociated sources in the Fermi LAT Bright Source List with the Green Bank Telescope at 820 MHz. We report the discovery of three radio and {gamma}-ray millisecond pulsars (MSPs) from a high Galactic latitude subset of these sources. All of the pulsars are in binary systems, which would have made them virtually impossible to detect in blind {gamma}-ray pulsation searches. They seem to be relatively normal, nearby ({<=}2 kpc) MSPs. These observations, in combination with the Fermi detection of {gamma}-rays from other known radio MSPs, imply that most, if not all, radio MSPs are efficient {gamma}-ray producers. The {gamma}-ray spectra of the pulsars are power law in nature with exponential cutoffs at a few GeV, as has been found with most other pulsars. The MSPs have all been detected as X-ray point sources. Their soft X-ray luminosities of {approx}10{sup 30}-10{sup 31} erg s{sup -1} are typical of the rare radio MSPs seen in X-rays.

  1. Essential amino acid transporter Lat4 (Slc43a2) is required for mouse development

    PubMed Central

    Guetg, Adriano; Mariotta, Luca; Bock, Lukas; Herzog, Brigitte; Fingerhut, Ralph; Camargo, Simone M R; Verrey, François

    2015-01-01

    Amino acid (AA) uniporter Lat4 (Slc43a2) mediates facilitated diffusion of branched-chain AAs, methionine and phenylalanine, although its physiological role and subcellular localization are not known. We report that Slc43a2 knockout mice were born at expected Mendelian frequency but displayed an ∼10% intrauterine growth retardation and low amniotic fluid AAs, suggesting defective transplacental transport. Postnatal growth was strongly reduced, with premature death occurring within 9 days such that further investigations were made within 3 days of birth. Lat4 immunofluorescence showed a strong basolateral signal in the small intestine, kidney proximal tubule and thick ascending limb epithelial cells of wild-type but not Slc43a2 null littermates and no signal in liver and skeletal muscle. Experiments using Xenopus laevis oocytes demonstrated that Lat4 functioned as a symmetrical low affinity uniporter with a K0.5 of ∼5 mm for both in- and efflux. Plasma AA concentration was decreased in Slc43a2 null pups, in particular that of non-essential AAs alanine, serine, histidine and proline. Together with an increased level of plasma long chain acylcarnitines and a strong alteration of liver gene expression, this indicates malnutrition. Attempts to rescue pups by decreasing the litter size or by nutrients injected i.p. did not succeed. Radioactively labelled leucine but not lysine given per os accumulated in the small intestine of Slc43a2null pups, suggesting the defective transcellular transport of Lat4 substrates. In summary, Lat4 is a symmetrical uniporter for neutral essential AAs localizing at the basolateral side of (re)absorbing epithelia and is necessary for early nutrition and development. Key points Lat4 (Slc43a2) transports branched-chain amino acids, phenylalanine and methionine, and is expressed in kidney tubule and small intestine epithelial cells. Using a new knockout model as a negative control, it is shown that Lat4 is expressed at the basolateral

  2. Deep view of the Large Magellanic Cloud with six years of Fermi-LAT observations

    NASA Astrophysics Data System (ADS)

    Ackermann, M.; Albert, A.; Atwood, W. B.; Baldini, L.; Ballet, J.; Barbiellini, G.; Bastieri, D.; Bellazzini, R.; Bissaldi, E.; Bloom, E. D.; Bonino, R.; Brandt, T. J.; Bregeon, J.; Bruel, P.; Buehler, R.; Caliandro, G. A.; Cameron, R. A.; Caragiulo, M.; Caraveo, P. A.; Cavazzuti, E.; Cecchi, C.; Charles, E.; Chekhtman, A.; Chiang, J.; Chiaro, G.; Ciprini, S.; Cohen-Tanugi, J.; Cutini, S.; D'Ammando, F.; de Angelis, A.; de Palma, F.; Desiante, R.; Digel, S. W.; Drell, P. S.; Favuzzi, C.; Ferrara, E. C.; Focke, W. B.; Franckowiak, A.; Fusco, P.; Gargano, F.; Gasparrini, D.; Giglietto, N.; Giordano, F.; Godfrey, G.; Grenier, I. A.; Grondin, M.-H.; Guillemot, L.; Guiriec, S.; Harding, A. K.; Hill, A. B.; Horan, D.; Jóhannesson, G.; Knödlseder, J.; Kuss, M.; Larsson, S.; Latronico, L.; Li, J.; Li, L.; Longo, F.; Loparco, F.; Lubrano, P.; Maldera, S.; Martin, P.; Mayer, M.; Mazziotta, M. N.; Michelson, P. F.; Mizuno, T.; Monzani, M. E.; Morselli, A.; Murgia, S.; Nuss, E.; Ohsugi, T.; Orienti, M.; Orlando, E.; Ormes, J. F.; Paneque, D.; Pesce-Rollins, M.; Piron, F.; Pivato, G.; Porter, T. A.; Rainò, S.; Rando, R.; Razzano, M.; Reimer, A.; Reimer, O.; Romani, R. W.; Sánchez-Conde, M.; Schulz, A.; Sgrò, C.; Siskind, E. J.; Smith, D. A.; Spada, F.; Spandre, G.; Spinelli, P.; Suson, D. J.; Takahashi, H.; Thayer, J. B.; Tibaldo, L.; Torres, D. F.; Tosti, G.; Troja, E.; Vianello, G.; Wood, M.; Zimmer, S.

    2016-02-01

    Context. The nearby Large Magellanic Cloud (LMC) provides a rare opportunity of a spatially resolved view of an external star-forming galaxy in γ-rays. The LMC was detected at 0.1-100 GeV as an extended source with CGRO/EGRET and using early observations with the Fermi-LAT. The emission was found to correlate with massive star-forming regions and to be particularly bright towards 30 Doradus. Aims: Studies of the origin and transport of cosmic rays (CRs) in the Milky Way are frequently hampered by line-of-sight confusion and poor distance determination. The LMC offers a complementary way to address these questions by revealing whether and how the γ-ray emission is connected to specific objects, populations of objects, and structures in the galaxy. Methods: We revisited the γ-ray emission from the LMC using about 73 months of Fermi-LAT P7REP data in the 0.2-100 GeV range. We developed a complete spatial and spectral model of the LMC emission, for which we tested several approaches: a simple geometrical description, template-fitting, and a physically driven model for CR-induced interstellar emission. Results: In addition to identifying PSR J0540-6919 through its pulsations, we find two hard sources positionally coincident with plerion N 157B and supernova remnant N 132D, which were also detected at TeV energies with H.E.S.S. We detect an additional soft source that is currently unidentified. Extended emission dominates the total flux from the LMC. It consists of an extended component of about the size of the galaxy and additional emission from three to four regions with degree-scale sizes. If it is interpreted as CRs interacting with interstellar gas, the large-scale emission implies a large-scale population of ~1-100 GeV CRs with a density of ~30% of the local Galactic value. On top of that, the three to four small-scale emission regions would correspond to enhancements of the CR density by factors 2 to 6 or higher, possibly more energetic and younger populations

  3. Recombinant outer membrane protein C of Aeromonas hydrophila elicits mixed immune response and generates agglutinating antibodies.

    PubMed

    Yadav, Sunita Kumari; Meena, Jitendra Kumar; Sharma, Mahima; Dixit, Aparna

    2016-08-01

    Aeromonas hydrophila is a gram-negative fish pathogenic bacterium, also responsible for causing opportunistic pathological conditions in humans. It causes a number of diseases in fish due to which the fish industry incurs huge economic losses annually. Due to problems of antibiotic resistance, and the rapidity with which the infection spreads among fishes, vaccination remains the most effective strategy to combat this infection in fish populations. Among various virulence factors associated with bacterial virulence, outer membrane proteins have been widely evaluated for their vaccine potential owing to their surface exposure and related role in pathogenicity. In the present study, we have investigated the immunogenic potential of a non-specific porin, outer membrane protein C (OmpC) whose expression is regulated by the two-component regulatory system and plays a major role in the survival of A. hydrophila under different osmolaric conditions. The full-length gene (~1 kb) encoding OmpC of A. hydrophila was cloned, characterized and expressed in E. coli. High yield (~112 mg/L at shake flask level) of the recombinant OmpC (rOmpC) (~40 kDa) of A. hydrophila was obtained upon purification from inclusion bodies using Ni(2+)-NTA affinity chromatography. Immunization with purified rOmpC in murine model generated high endpoint (>1:40,000) titers. IgG isotyping, ELISA and ELISPOT assay indicated mixed immune response with a TH2 bias. Also, the anti-rOmpC antibodies were able to agglutinate A. hydrophila in vitro and exhibited specific cross-reactivity with different Aeromonas strains, which will facilitate easy detection of different Aeromonas isolates in infected samples. Taken together, these data clearly indicate that rOmpC could serve as an effective vaccine against different strains of Aeromonas, a highly heterogenous group of bacteria. PMID:27328672

  4. Agglutinating secretory IgA preserves intestinal epithelial cell integrity during apical infection by Shigella flexneri.

    PubMed

    Mathias, Amandine; Longet, Stéphanie; Corthésy, Blaise

    2013-08-01

    Shigella flexneri, by invading intestinal epithelial cells (IECs) and inducing inflammatory responses of the colonic mucosa, causes bacillary dysentery. Although M cells overlying Peyer's patches are commonly considered the primary site of entry of S. flexneri, indirect evidence suggests that bacteria can also use IECs as a portal of entry to the lamina propria. Passive delivery of secretory IgA (SIgA), the major immunoglobulin secreted at mucosal surfaces, has been shown to protect rabbits from experimental shigellosis, but no information exists as to its molecular role in maintaining luminal epithelial integrity. We have established that the interaction of virulent S. flexneri with the apical pole of a model intestinal epithelium consisting of polarized Caco-2 cell monolayers resulted in the progressive disruption of the tight junction network and actin depolymerization, eventually resulting in cell death. The lipopolysaccharide (LPS)-specific agglutinating SIgAC5 monoclonal antibody (MAb), but not monomeric IgAC5 or IgGC20 MAbs of the same specificity, achieved protective functions through combined mechanisms, including limitation of the interaction between S. flexneri and epithelial cells, maintenance of the tight junction seal, preservation of the cell morphology, reduction of NF-κB nuclear translocation, and inhibition of proinflammatory mediator secretion. Our results add to the understanding of the function of SIgA-mediated immune exclusion by identifying a mode of action whereby the formation of immune complexes translates into maintenance of the integrity of epithelial cells lining the mucosa. This novel mechanism of protection mediated by SIgA is important to extend the arsenal of effective strategies to fight against S. flexneri mucosal invasion. PMID:23753631

  5. Agglutinating Secretory IgA Preserves Intestinal Epithelial Cell Integrity during Apical Infection by Shigella flexneri

    PubMed Central

    Mathias, Amandine; Longet, Stéphanie

    2013-01-01

    Shigella flexneri, by invading intestinal epithelial cells (IECs) and inducing inflammatory responses of the colonic mucosa, causes bacillary dysentery. Although M cells overlying Peyer's patches are commonly considered the primary site of entry of S. flexneri, indirect evidence suggests that bacteria can also use IECs as a portal of entry to the lamina propria. Passive delivery of secretory IgA (SIgA), the major immunoglobulin secreted at mucosal surfaces, has been shown to protect rabbits from experimental shigellosis, but no information exists as to its molecular role in maintaining luminal epithelial integrity. We have established that the interaction of virulent S. flexneri with the apical pole of a model intestinal epithelium consisting of polarized Caco-2 cell monolayers resulted in the progressive disruption of the tight junction network and actin depolymerization, eventually resulting in cell death. The lipopolysaccharide (LPS)-specific agglutinating SIgAC5 monoclonal antibody (MAb), but not monomeric IgAC5 or IgGC20 MAbs of the same specificity, achieved protective functions through combined mechanisms, including limitation of the interaction between S. flexneri and epithelial cells, maintenance of the tight junction seal, preservation of the cell morphology, reduction of NF-κB nuclear translocation, and inhibition of proinflammatory mediator secretion. Our results add to the understanding of the function of SIgA-mediated immune exclusion by identifying a mode of action whereby the formation of immune complexes translates into maintenance of the integrity of epithelial cells lining the mucosa. This novel mechanism of protection mediated by SIgA is important to extend the arsenal of effective strategies to fight against S. flexneri mucosal invasion. PMID:23753631

  6. A kinase shRNA screen links LATS2 and the pRB tumor suppressor.

    PubMed

    Tschöp, Katrin; Conery, Andrew R; Litovchick, Larisa; Decaprio, James A; Settleman, Jeffrey; Harlow, Ed; Dyson, Nicholas

    2011-04-15

    pRB-mediated inhibition of cell proliferation is a complex process that depends on the action of many proteins. However, little is known about the specific pathways that cooperate with the Retinoblastoma protein (pRB) and the variables that influence pRB's ability to arrest tumor cells. Here we describe two shRNA screens that identify kinases that are important for pRB to suppress cell proliferation and pRB-mediated induction of senescence markers. The results reveal an unexpected effect of LATS2, a component of the Hippo pathway, on pRB-induced phenotypes. Partial knockdown of LATS2 strongly suppresses some pRB-induced senescence markers. Further analysis shows that LATS2 cooperates with pRB to promote the silencing of E2F target genes, and that reduced levels of LATS2 lead to defects in the assembly of DREAM (DP, RB [retinoblastoma], E2F, and MuvB) repressor complexes at E2F-regulated promoters. Kinase assays show that LATS2 can phosphorylate DYRK1A, and that it enhances the ability of DYRK1A to phosphorylate the DREAM subunit LIN52. Intriguingly, the LATS2 locus is physically linked with RB1 on 13q, and this region frequently displays loss of heterozygosity in human cancers. Our results reveal a functional connection between the pRB and Hippo tumor suppressor pathways, and suggest that low levels of LATS2 may undermine the ability of pRB to induce a permanent cell cycle arrest in tumor cells.

  7. Evidence of hadronic interaction in Tycho Supernova Remnant using Fermi-LAT data

    NASA Astrophysics Data System (ADS)

    Caragiulo, M.; Di Venere, L.

    2014-11-01

    The Fermi Large Area Telescope (LAT) has observed Tycho Supernova Remnant in the MeV-GeV energy range. The spectrum has been studied using the first three years of data and new data are being collected. We present a multiwavelength model of the observed spectrum from radio to TeV energy range, based on the hypothesis of hadronic origin of γ-rays. As described by the Fermi acceleration theory, a single proton population was considered, modeled with a simple power-law in momentum. The photon emissivity is computed following Kamae et al (2006) [T. Kamae, et al., ApJ 647 (2006) 692]. The leptonic component is also taken into account according to Giordano et al. (2012) [F. Giordano, et al., ApJ 744 (2012) L2] prescriptions and it turns out to be negligible with respect to the hadronic one. The model returns a spectral index of 2.23 (± 0.05) and an acceleration efficiency of 5% of the total kinetic energy expelled in Supernova explosion and it may provide a hint of the acceleration processes in SNRs up to energies close to the knee of cosmic ray spectrum. This work shows that experimental data can be easily explained with a simple model, representing a good test for the acceleration theory.

  8. Cloning of two genes (LAT1,2) encoding specific L: -arabinose transporters of the L: -arabinose fermenting yeast Ambrosiozyma monospora.

    PubMed

    Verho, Ritva; Penttilä, Merja; Richard, Peter

    2011-07-01

    We identified and characterized two genes, LAT1 and LAT2, which encode specific L: -arabinose transporters. The genes were identified in the L: -arabinose fermenting yeast Ambrosiozyma monospora. The yeast Saccharomyces cerevisiae had only very low L: -arabinose transport activity; however, when LAT1 or LAT2 was expressed, L: -arabinose transport was facilitated. When the LAT1 or LAT2 were expressed in an S. cerevisiae mutant where the main hexose transporters were deleted, the L: -arabinose transporters could not restore growth on D: -glucose, D: -fructose, D: -mannose or D: -galactose. This indicates that these sugars are not transported and suggests that the transporters are specific for L: -arabinose.

  9. ENERGETIC FERMI/LAT GRB 100414A: ENERGETIC AND CORRELATIONS

    SciTech Connect

    Urata, Yuji; Tsai, Patrick P.; Huang, Kuiyun; Yamaoka, Kazutaka; Tashiro, Makoto S.

    2012-03-20

    This study presents multi-wavelength observational results for energetic GRB 100414A with GeV photons. The prompt spectral fitting using Suzaku/WAM data yielded spectral peak energies of E{sup src}{sub peak} of 1458.7{sup +132.6}{sub -106.6} keV and E{sub iso} of 34.5{sup +2.0}{sub -1.8} Multiplication-Sign 10{sup 52} erg with z = 1.368. The optical afterglow light curves between 3 and 7 days were effectively fitted according to a simple power law with a temporal index of {alpha} = -2.6 {+-} 0.1. The joint light curve with earlier Swift/UVOT observations yields a temporal break at 2.3 {+-} 0.2 days. This was the first Fermi/LAT detected event that demonstrated the clear temporal break in the optical afterglow. The jet opening angle derived from this temporal break was 5.{sup 0}8, consistent with those of other well-observed long gamma-ray bursts (GRBs). The multi-wavelength analyses in this study showed that GRB 100414A follows E{sup src}{sub peak}-E{sub iso} and E{sup src}{sub peak}-E{sub {gamma}} correlations. The late afterglow revealed a flatter evolution with significant excesses at 27.2 days. The most straightforward explanation for the excess is that GRB 100414A was accompanied by a contemporaneous supernova. The model light curve based on other GRB-SN events is marginally consistent with that of the observed light curve.

  10. Identification of a novel latency-specific splice donor signal within the herpes simplex virus type 1 2.0-kilobase latency-associated transcript (LAT): translation inhibition of LAT open reading frames by the intron within the 2.0-kilobase LAT.

    PubMed

    Spivack, J G; Woods, G M; Fraser, N W

    1991-12-01

    Herpes simplex virus type 1 establishes latent infection in trigeminal ganglia of mice infected via the eye. A family of three colinear viral transcripts (LATs), 2.0, 1.5, and 1.45 kb, is present in latently infected ganglia. To characterize these LATs, lambda gt10 cDNA libraries were constructed with RNAs isolated from the trigeminal ganglia of latently infected mice. A series of recombinant bacteriophage were isolated containing cDNA inserts covering 1.7 kb of the 2.0-kb LAT. Splice junctions of the smaller LATs and the 3' end of the 2.0-kb LAT were identified by sequence analysis of RNA polymerase chain reaction products. No splice acceptor site, which does not support the hypotheses that the 2.0-kb LAT is an intron. However, the data are consistent with the possibility of a short leader sequence or multiple LAT transcription start sites. To generate the smaller 1.5- and 1.45-kb LATs, there is a 559-nucleotide intron spliced from the 2.0-kb LAT in strain F and a 556-nucleotide intron in strain 17+. The nucleotide sequences at the 5' and 3' ends of these introns are characteristic of spliced transcripts from eukaryotic protein-encoding genes, with one significant difference; i.e., the 5' end of the LAT intron is GC instead of the consensus sequence GT. This splice donor sequence is conserved in herpes simplex virus type 1 strains F, 17+, and KOS. Processing of the 2.0-kb LAT to form the spliced LATs preserves two open reading frames (ORFs) at the 3' end of the LATs; no new ORFs are created. Splicing of the LATs positions a 276-nucleotide leader sequence close to these ORFs and removes an intron that inhibits their translation in vitro. The novel 5' structure of the intron within the 2.0-kb LAT may be part of a control mechanism for transcription processing that results in splicing of the LATs only in sensory neurons during latent infection and reactivation but not during the viral replication cycle.

  11. Cerebral Cortex Hyperthyroidism of Newborn Mct8-Deficient Mice Transiently Suppressed by Lat2 Inactivation

    PubMed Central

    Núñez, Bárbara; Martínez de Mena, Raquel; Obregon, Maria Jesus; Font-Llitjós, Mariona; Nunes, Virginia; Palacín, Manuel; Dumitrescu, Alexandra M.; Morte, Beatriz; Bernal, Juan

    2014-01-01

    Thyroid hormone entry into cells is facilitated by transmembrane transporters. Mutations of the specific thyroid hormone transporter, MCT8 (Monocarboxylate Transporter 8, SLC16A2) cause an X-linked syndrome of profound neurological impairment and altered thyroid function known as the Allan-Herndon-Dudley syndrome. MCT8 deficiency presumably results in failure of thyroid hormone to reach the neural target cells in adequate amounts to sustain normal brain development. However during the perinatal period the absence of Mct8 in mice induces a state of cerebral cortex hyperthyroidism, indicating increased brain access and/or retention of thyroid hormone. The contribution of other transporters to thyroid hormone metabolism and action, especially in the context of MCT8 deficiency is not clear. We have analyzed the role of the heterodimeric aminoacid transporter Lat2 (Slc7a8), in the presence or absence of Mct8, on thyroid hormone concentrations and on expression of thyroid hormone-dependent cerebral cortex genes. To this end we generated Lat2-/-, and Mct8-/yLat2-/- mice, to compare with wild type and Mct8-/y mice during postnatal development. As described previously the single Mct8 KO neonates had a transient increase of 3,5,3′-triiodothyronine concentration and expression of thyroid hormone target genes in the cerebral cortex. Strikingly the absence of Lat2 in the double Mct8Lat2 KO prevented the effect of Mct8 inactivation in newborns. The Lat2 effect was not observed from postnatal day 5 onwards. On postnatal day 21 the Mct8 KO displayed the typical pattern of thyroid hormone concentrations in plasma, decreased cortex 3,5,3′-triiodothyronine concentration and Hr expression, and concomitant Lat2 inactivation produced little to no modifications. As Lat2 is expressed in neurons and in the choroid plexus, the results support a role for Lat2 in the supply of thyroid hormone to the cerebral cortex during early postnatal development. PMID:24819605

  12. Constraints on the pMSSM from LAT Observations of Dwarf Spheroidal Galaxies

    SciTech Connect

    Cotta, R.C.; Drlica-Wagner, A.; Murgia, S.; Bloom, E.D.; Hewett, J.L.; Rizzo, T.G.; /SLAC

    2012-03-15

    We examine the ability for the Large Area Telescope (LAT) to constrain Minimal Supersymmetric Standard Model (MSSM) dark matter through a combined analysis of Milky Way dwarf spheroidal galaxies. We examine the Lightest Supersymmetric Particles (LSPs) for a set of {approx}71k experimentally valid supersymmetric models derived from the phenomenological-MSSM (pMSSM). We find that none of these models can be excluded at 95% confidence by the current analysis; nevertheless, many lie within the predicted reach of future LAT analyses. With two years of data, we find that the LAT is currently most sensitive to light LSPs (mLSP < 50 GeV) annihilating into {tau}-pairs and heavier LSPs annihilating into b{bar b}. Additionally, we find that future LAT analyses will be able to probe some LSPs that form a sub-dominant component of dark matter. We directly compare the LAT results to direct detection experiments and show the complementarity of these search methods.

  13. NuLat: A Novel Design for a Reactor Anti-Neutrino Detector

    NASA Astrophysics Data System (ADS)

    Rountree, S. Derek; NuLat Collaboration

    2015-04-01

    NuLat is a proposed very-short baseline (3-10m) reactor electron antineutrino (anti-νe) experiment that will probe the current best fit for light sterile neutrino mixing, the 5 MeV excess seen in current short baseline reactor experiments, and serve as a portable surface detector for cooperative (~ 30m baseline) surface monitoring of reactors. The NuLat detector will use an optically segmented 3D Raghavan optical lattice (ROL) detector that channels light via total internal reflection from a scintillation event down the 3 primary axes to the detector faces. The high degree of segmentation allows for each voxel's energy to be determined independently of other voxels, thus providing high temporal and spatial resolution and energy reconstruction independent of position. NuLat detects anti-νe via inverse beta decay (IBD), which produces a positron and a neutron. Most of the time, the positron deposits its kinetic energy into a single voxel allowing superior derivation of the incident anti-νe's energy. The final state neutron is captured via (n, α) on 6 Li or 10 B after a characteristic delay time giving a coincidence tag. This talk will discuss the physics reach of NuLat using a solid loaded scintillator, and the timeline of the NuLat reactor anti-νe program. This research has been funded in part by the National Science Foundation on Award Numbers 1001394 and 1001078.

  14. The X-Ray Counterpart to LAT PSR J2021+4026 and Its Interesting Spectrum

    NASA Technical Reports Server (NTRS)

    Weisskopf, Martin C.; Becker, W.; Carraminana, A.; De Luca, A.; Dormandy, M.; Harding, A.; Kanbach, G.; O'Dell, S. L.; Parkinson, P. Saz; Ray, P.; Razzano, M.; Romani, R.; Tennant, A. F.; Swarz, D. A.; Thompson, D.; Ziegler, M.

    2011-01-01

    We report on the likely identification of the X-ray counterpart to LAT PSR J2021+4026, using the Chandra X-Ray Observatory ACIS-S3 and timing analysis of Large Area telescope (LAT) data from the Fermi satellite. The X-ray source that lies closest (10 arcsec) to the position determined from the Fermi-LAT timing solution has no cataloged infrared-to-visible counterpart and we have set an upper limit to its optical I and R band emission. The source exhibits a X-ray spectrum which is different when compared to Geminga and CTA 1, and this may have implications for the evolutionary track of radio-quiet gamma-ray pulsars.

  15. Sharper Fermi LAT images: instrument response functions for an improved event selection

    SciTech Connect

    Portillo, Stephen K. N.; Finkbeiner, Douglas P.

    2014-11-20

    The Large Area Telescope (LAT) on the Fermi Gamma-ray Space Telescope has a point-spread function (PSF) with large tails, consisting of events affected by tracker inefficiencies, inactive volumes, and hard scattering; these tails can make source confusion a limiting factor. The parameter CTBCORE, available in the publicly available Extended Fermi LAT data (available at http://fermi.gsfc.nasa.gov/ssc/data/access/), estimates the quality of each event's direction reconstruction; by implementing a cut in this parameter, the tails of the PSF can be suppressed at the cost of losing effective area. We implement cuts on CTBCORE and present updated instrument response functions derived from the Fermi LAT data itself, along with all-sky maps generated with these cuts. Having shown the effectiveness of these cuts, especially at low energies, we encourage their use in analyses where angular resolution is more important than Poisson noise.

  16. Sharper Fermi LAT Images: Instrument Response Functions for an Improved Event Selection

    NASA Astrophysics Data System (ADS)

    Portillo, Stephen K. N.; Finkbeiner, Douglas P.

    2014-11-01

    The Large Area Telescope (LAT) on the Fermi Gamma-ray Space Telescope has a point-spread function (PSF) with large tails, consisting of events affected by tracker inefficiencies, inactive volumes, and hard scattering; these tails can make source confusion a limiting factor. The parameter CTBCORE, available in the publicly available Extended Fermi LAT data (available at http://fermi.gsfc.nasa.gov/ssc/data/access/), estimates the quality of each event's direction reconstruction; by implementing a cut in this parameter, the tails of the PSF can be suppressed at the cost of losing effective area. We implement cuts on CTBCORE and present updated instrument response functions derived from the Fermi LAT data itself, along with all-sky maps generated with these cuts. Having shown the effectiveness of these cuts, especially at low energies, we encourage their use in analyses where angular resolution is more important than Poisson noise.

  17. Differential agglutination by soybean agglutinin of human leukemia and neuroblastoma cell lines: potential application to autologous bone marrow transplantation.

    PubMed

    Reisner, Y

    1983-11-01

    Normal human bone marrow cells were mixed with radioactively labeled tumor cells from different leukemia and neuroblastoma cell lines, and the cell mixtures were separated by differential agglutination with soybean agglutinin. It is shown that the cell fraction unagglutinated by soybean agglutinin, which was previously found to be capable of reconstituting the hematopoietic system of lethally irradiated recipients, can be purged of tumor cells with varying efficiency depending on the tumor cell expression of soybean agglutinin receptors as detected by flow cytofluorimetry with fluoresceinated soybean agglutinin.

  18. Evaluation of four commercial IgG- and IgM-specific enzyme immunoassays for detecting Mycoplasma pneumoniae antibody: comparison with particle agglutination assay.

    PubMed

    Yoo, Soo Jin; Oh, Hye-Jeon; Shin, Bo-Moon

    2007-10-01

    Diagnosis of Mycoplasma pneumoniae infection is important due to its variable clinical manifestations and absence of response to beta-lactams. Introduction of enzyme immunoassays (EIAs) for serologic diagnosis of M. pneumoniae has made it possible to separate the analyses of specific IgG and IgM antibodies. We compared four different commercial EIAs, ImmunoWELL IgG, IgM (GenBio), Medac IgG, IgA, IgM (Medac), Platelia IgG, IgM (Sanofi Pasteur), and Ridascreen IgG, IgA, IgM (r-Biopharm) with indirect particle agglutination assay (PA), Serodia-MycoII (Fujirebio). We tested 91 specimens from 73 pediatric patients (2-17 yr) hospitalized at a tertiary-care hospital between December 2005 and January 2006. The measurements of IgM EIAs were correlated with PA titers (Spearman's correlation coefficient, from 0.89 to 0.92) with high concordance rates, ranging from 82.4% to 92.3%. However, some negative IgM-EIA results in PA-positive specimens indicated that serial samplings with convalescent sera would be necessary to confirm M. pneumoniae infection.

  19. Tomography of the Fermi-LAT γ-Ray Diffuse Extragalactic Signal via Cross Correlations with Galaxy Catalogs

    NASA Astrophysics Data System (ADS)

    Xia, Jun-Qing; Cuoco, Alessandro; Branchini, Enzo; Viel, Matteo

    2015-03-01

    Building on our previous cross-correlation analysis (Xia et al. 2011) between the isotropic γ-ray background (IGRB) and different tracers of the large-scale structure of the universe, we update our results using 60 months of data from the Large Area Telescope (LAT) on board the Fermi Gamma-ray Space Telescope (Fermi). We perform a cross-correlation analysis both in configuration and spherical harmonics space between the IGRB and objects that may trace the astrophysical sources of the IGRB: QSOs in the Sloan Digital Sky Survey (SDSS) DR6, the SDSS DR8 Main Galaxy Sample, luminous red galaxies (LRGs) in the SDSS catalog, infrared-selected galaxies in the Two Micron All Sky Survey (2MASS), and radio galaxies in the NRAO VLA Sky Survey (NVSS). The benefit of correlating the Fermi-LAT signal with catalogs of objects at various redshifts is to provide tomographic information on the IGRB, which is crucial in separating the various contributions and clarifying its origin. The main result is that, unlike in our previous analysis, we now observe a significant (>3.5σ) cross-correlation signal on angular scales smaller than 1° in the NVSS, 2MASS, and QSO cases and, at lower statistical significance (∼3.0σ), with SDSS galaxies. The signal is stronger in two energy bands, E > 0.5 GeV and E > 1 GeV, but it is also seen at E > 10 GeV. No cross-correlation signal is detected between Fermi data and the LRGs. These results are robust against the choice of the statistical estimator, estimate of errors, map cleaning procedure, and instrumental effects. Finally, we test the hypothesis that the IGRB observed by Fermi-LAT originates from the summed contributions of three types of unresolved extragalactic sources: BL Lacertae objects (BL Lacs), flat spectrum radio quasars (FSRQs), and star-forming galaxies (SFGs). We find that a model in which the IGRB is mainly produced by SFGs (72-37+23% with 2σ errors), with BL Lacs and FSRQs giving a minor contribution, provides a good fit to

  20. A Case of Leser-Trélat Syndrome Associated with a Renal Cell Carcinoma

    PubMed Central

    Barth, Dietrich; Puhlmann, Silvio; Barth, Joachim

    2015-01-01

    Seborrheic keratoses can often be found in elderly people. In general, they appear gradually. In cases of a sudden eruption with itching it might be paraneoplastic. Although some authors doubt the existence of the paraneoplastic Leser-Trélat syndrome, we present a case of sudden eruption of seborrheic keratoses connected with a newly diagnosed renal cell carcinoma. As far as we know, this is the first case report of a Leser-Trélat syndrome with a malignancy of the kidney. PMID:26500537

  1. Fermi-LAT Gamma-ray Observations of Nova Lupus 2016 (ASASSN-16kt)

    NASA Astrophysics Data System (ADS)

    Cheung, C. C.; Jean, P.; Shore, S. N.; Fermi Large Area Telescope Collaboration

    2016-10-01

    The Fermi Gamma-ray Space Telescope performed a ~6-day Target of Opportunity (ToO) observation of Nova Lupus 2016 (ATel #9538, #9539, CBET #4322) that commenced on September 28. Considering earlier all-sky survey Large Area Telescope (LAT) observations as well, preliminary analysis indicates gamma-ray emission at ~2 sigma was detected around 1 to 2 days after the optical peak on September 25th (pre-validated AAVSO visual lightcurve; ATel #9550, CBET #4322) when the optical spectra show opaque ejecta, similar to previous gamma-ray detected novae (Fermi-LAT collaboration, 2014 Science 345, 554; Cheung et al. 2016 ApJ 826, 142).

  2. First Results From GLAST-LAT Integrated Towers Cosmic Ray Data Taking And Monte Carlo Comparison

    SciTech Connect

    Brigida, M.; Caliandro, A.; Favuzzi, C.; Fusco, P.; Gargano, F.; Giordano, F.; Giglietto, N.; Loparco, F.; Marangelli, B.; Mazziotta, M.N.; Mirizzi, N.; Raino, S.; Spinelli, P.; /Bari U. /INFN, Bari

    2007-02-15

    GLAST Large Area Telescope (LAT) is a gamma ray telescope instrumented with silicon-strip detector planes and sheets of converter, followed by a calorimeter (CAL) and surrounded by an anticoincidence system (ACD). This instrument is sensitive to gamma rays in the energy range between 20 MeV and 300 GeV. At present, the first towers have been integrated and pre-launch data taking with cosmic ray muons is being performed. The results from the data analysis carried out during LAT integration will be discussed and a comparison with the predictions from the Monte Carlo simulation will be shown.

  3. Cloning and molecular characterization of cationic amino acid transporter y⁺LAT1 in grass carp (Ctenopharyngodon idellus).

    PubMed

    Yang, Jixuan; Tan, Qingsong; Zhu, Wenhuan; Chen, Chen; Liang, Xufang; Pan, Lei

    2014-02-01

    The solute carrier family 7A, member 7 gene encodes the light chain- y⁺L amino acid transporter-1 (y⁺LAT1) of the heterodimeric carrier responsible for cationic amino acid (CAA) transport across the basolateral membranes of epithelial cells in intestine and kidney. Rising attention has been given to y⁺LAT1 involved in CAA metabolic pathways and growth control. The molecular characterization and function analysis of y⁺LAT1 in grass carp (Ctenopharyngodon idellus) is currently unknown. In the present study, full-length cDNA (2,688 bp), which encodes y⁺LAT1 and contains a 5'-untranslated region (319 bp), an open reading frame (1,506 bp) and a 3'-untranslated region (863 bp), has been cloned from grass carp. Amino acid sequence of grass carp y⁺LAT1 contains 11 transmembrane domains and shows 95 %, 80 % and 75 % sequence similarity to zebra fish, amphibian and mammalian y⁺LAT1, respectively. The tissue distribution and expression regulation by fasting of y⁺LAT1 mRNA were analyzed using real-time PCR. Our results showed that y⁺LAT1 mRNA was highly expressed in midgut, foregut and spleen while weakly expressed in hindgut, kidney, gill, brain, heart, liver and muscle. Nutritional status significantly influenced y⁺LAT1 mRNA expression in fish tissues, such as down-regulation of y⁺LAT1 mRNA expression after fasting (14 days).

  4. 9 CFR 145.14 - Testing.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 0579-0007) Editorial Note: For Federal Register citations affecting § 145.14, see the List of CFR...-typhoid shall be the standard tube agglutination test, the microagglutination test, the enzyme-linked... microtest antigens and enzyme-linked immunosorbent assay reagents shall also be approved by the...

  5. 9 CFR 145.14 - Testing.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 0579-0007) Editorial Note: For Federal Register citations affecting § 145.14, see the List of CFR...-typhoid shall be the standard tube agglutination test, the microagglutination test, the enzyme-linked... microtest antigens and enzyme-linked immunosorbent assay reagents shall also be approved by the...

  6. Minimization of bacterial size allows for complement evasion and is overcome by the agglutinating effect of antibody

    PubMed Central

    Dalia, Ankur B.; Weiser, Jeffrey N.

    2011-01-01

    SUMMARY The complement system, which functions by lysing pathogens directly or by promoting their uptake by phagocytes, is critical for controlling many microbial infections. Here we show that in Streptococcus pneumoniae, increasing bacterial chain length sensitizes this pathogen to complement deposition and subsequent uptake by human neutrophils. Consistent with this, we show that minimizing chain length provides wild-type bacteria with a competitive advantage in vivo in a model of systemic infection. Investigating how the host overcomes this virulence strategy, we find that antibody promotes complement-dependent opsonophagocytic killing of Streptococcus pneumoniae and lysis of Haemophilus influenzae independent of Fc-mediated effector functions. Consistent with the agglutinating effect of antibody, F(ab′)2 but not Fab could promote this effect. Therefore, increasing pathogen size, whether by natural changes in cellular morphology or via antibody-mediated agglutination, promotes complement-dependent killing. These observations have broad implications for how cell size and morphology can affect virulence among pathogenic microbes. PMID:22100164

  7. Insights into the Antimicrobial Mechanism of Action of Human RNase6: Structural Determinants for Bacterial Cell Agglutination and Membrane Permeation

    PubMed Central

    Pulido, David; Arranz-Trullén, Javier; Prats-Ejarque, Guillem; Velázquez, Diego; Torrent, Marc; Moussaoui, Mohammed; Boix, Ester

    2016-01-01

    Human Ribonuclease 6 is a secreted protein belonging to the ribonuclease A (RNaseA) superfamily, a vertebrate specific family suggested to arise with an ancestral host defense role. Tissue distribution analysis revealed its expression in innate cell types, showing abundance in monocytes and neutrophils. Recent evidence of induction of the protein expression by bacterial infection suggested an antipathogen function in vivo. In our laboratory, the antimicrobial properties of the protein have been evaluated against Gram-negative and Gram-positive species and its mechanism of action was characterized using a membrane model. Interestingly, our results indicate that RNase6, as previously reported for RNase3, is able to specifically agglutinate Gram-negative bacteria as a main trait of its antimicrobial activity. Moreover, a side by side comparative analysis with the RN6(1–45) derived peptide highlights that the antimicrobial activity is mostly retained at the protein N-terminus. Further work by site directed mutagenesis and structural analysis has identified two residues involved in the protein antimicrobial action (Trp1 and Ile13) that are essential for the cell agglutination properties. This is the first structure-functional characterization of RNase6 antimicrobial properties, supporting its contribution to the infection focus clearance. PMID:27089320

  8. siRNA delivery targeting to the lung via agglutination-induced accumulation and clearance of cationic tetraamino fullerene

    NASA Astrophysics Data System (ADS)

    Minami, Kosuke; Okamoto, Koji; Doi, Kent; Harano, Koji; Noiri, Eisei; Nakamura, Eiichi

    2014-05-01

    The efficient treatment of lung diseases requires lung-selective delivery of agents to the lung. However, lung-selective delivery is difficult because the accumulation of micrometer-sized carriers in the lung often induces inflammation and embolization-related toxicity. Here we demonstrate a lung-selective delivery system of small interfering RNA (siRNA) by controlling the size of carrier vehicle in blood vessels. The carrier is made of tetra(piperazino)fullerene epoxide (TPFE), a water-soluble cationic tetraamino fullerene. TPFE and siRNA form sub-micrometer-sized complexes in buffered solution and these complexes agglutinate further with plasma proteins in the bloodstream to form micrometer-sized particles. The agglutinate rapidly clogs the lung capillaries, releases the siRNA into lung cells to silence expression of target genes, and is then cleared rapidly from the lung after siRNA delivery. We applied our delivery system to an animal model of sepsis, indicating the potential of TPFE-based siRNA delivery for clinical applications.

  9. Monounsaturated fatty acid ether oligomers formed during heating of virgin olive oil show agglutination activity against human red blood cells.

    PubMed

    Patrikios, Ioannis S; Mavromoustakos, Thomas M

    2014-01-29

    The present work focuses on the characterization of molecules formed when virgin olive oil is heated at 130 °C for 24 h open in air, which are found to be strong agglutinins. The hemagglutinating activity of the newly formed molecule isolated from the heated virgin olive oil sample was estimated against human red blood cells (RBCs). Dimers and polymers (high molecular weight molecules) were identified through thin layer chromatography (TLC) of the oil mixture. (1)H and (13)C nuclear magnetic resonance (NMR) and gas chromatography-mass spectroscopy (GC-MS) were the methods used for structural characterization. Among others, oligomerization of at least two monounsaturated fatty acids (FA) by an ether linkage between the hydrocarbon chains is involved. Light microscopy was used to characterize and visualize the agglutination process. Agglutination without fusion or lysis was observed. It was concluded that the heating of virgin olive oil open in air, among other effects, produces oligomerization as well as polymerization of unsaturated FA, possibly of monohydroxy, monounsaturated FA that is associated with strong hemagglutinating activity against human RBCs. The nutritional value and the effects on human health of such oligomers are not discussed in the literature and remain to be investigated. PMID:24410166

  10. Study of polycation effects on erythrocyte agglutination mediated by anti-glycophorins using microscopic image digital analysis

    NASA Astrophysics Data System (ADS)

    Riquelme, B.; Dumas, D.; Relancio, F.; Fontana, A.; Alessi, A.; Foresto, P.; Grandfils, C.; Stoltz, J.; Valverde, J.

    2006-04-01

    The aim of this work was to study synthetic polycation effects on erythrocyte agglutination mediated by anti-glycophorin using image digital analysis. Polycations are oligomers or polymers of natural or synthetic origin, which bear a great number of positive charges at pH 7.4. Several of these polycations are nowadays used in clinic for human and veterinary purposes. New applications of polycations to the development of new drug delivery systems are investigated, in order to promote the drug absorption through the gastro-intestinal and blood brain barriers. However, up to now, there are no clear relationships between macromolecular features of polycations (molecular weight, mean charge density, charge repartition, etc.) and their interactions with blood elements (which bear superficial negative charges). The interaction on the red blood cell membrane with synthetic polycations having well-controlled macromolecular features and functionalized with pendent polyethylene glycol segments was investigated. The alterations over stationary and dynamic viscoelastic properties of erythrocyte membranes were analyzed through laser diffractometry. Image digital analysis was used to study erythrocyte agglutination mediated by anti-glycophorin. Results show different reactivities of the polycations on the erythrocyte membrane. These findings could provide more information about the mechanisms of polycation interaction on erythrocyte membranes. We consider that this work could provide useful tools to understand and improve the haemocompatibility of polycations and enlarge their potential in clinic.

  11. Differential lytic and agglutinating activity of the anti-Lewis(x) monoclonal antibody FC-2.15 on human polymorphonuclear neutrophils and MCF-7 breast tumor cells. In vitro and ex vivo studies.

    PubMed

    Capurro, M; Ballaré, C; Bover, L; Portela, P; Mordoh, J

    1999-01-01

    The Lewis(x) (Le(x)) trisaccharide (CD15) linked to proteins and glycolipids is highly expressed on the surface of normal human polymorphonuclear neutrophils (PMN) and several human neoplasias, such as breast and gastrointestinal carcinomas and chronic myeloid leukemias. FC-2.15 is an IgM murine mAb that specifically recognizes Le(x) and has been previously shown to mediate the in vitro lysis of Le(x)(+) cells by human complement. In a phase I clinical trial of FC-2.15, a temporary neutropenia was the main toxicity, and antitumor responses were observed. In order to characterize FC-2.15 further and determine the physiological relevance of Le(x) binding, the reactivity of FC-2.15 on PMN was investigated under several conditions. Flow cytometry revealed a strong reactivity of FC-2.15 with almost 100% of PMN, and Scatchard analysis demonstrated an affinity constant of 5.14 x 10(9) M(-1) and 1.11 x 10(6) antigen sites/cell. In vitro, the binding of Le(x) epitopes by FC-2.15 induced PMN homotypic aggregation, only 28.4 +/- 4.1% remaining as single cells. When PMN and the Le(x)(+) MCF-7 breast cancer cells were co-incubated, FC-2.15 induced heterotypic aggregation. In 51Cr-release assays employing human complement, FC-2.15 lysed 93.4 +/- 7.9% of PMN and 87.8 +/- 10.7% of MCF-7 cells. However, when the effect of FC-2.15 was tested in ex vivo circulating blood, no lytic activity against PMN was detected, whereas MCF-7 cells were still lysed. Blood smears demonstrated that FC-2.15 induced PMN agglutination and heterotypic aggregates when MCF-7 cells were present. A pretreatment of PMN with colchicine impaired PMN agglutination both in vitro (single PMN = 81.15 +/- 4.35%) and in ex vivo circulating blood. In the latter condition, FC-2.15-lytic activity was restored, suggesting that PMN homotypic aggregation by FC-2.15, but not lysis, is dependent on microtubule integrity and that PMN agglutination hinders their lysis. Moreover, when 51Cr-release assays were performed

  12. Fermi-LAT Gamma-Ray Bursts and Insights from Swift

    NASA Technical Reports Server (NTRS)

    Racusin, Judith L.

    2010-01-01

    A new revolution in Gamma-ray Burst (GRB) observations and theory has begun over the last two years since the launch of the Fermi Gamma-ray Space Telescope. The new window into high energy gamma-rays opened by the Fermi-Large Area Telescope (LAT) is providing insight into prompt emission mechanisms and possibly also afterglow physics. The LAT detected GRBs appear to be a new unique subset of extremely energetic and bright bursts compared to the large sample detected by Swift over the last 6 years. In this talk, I will discuss the context and recent discoveries from these LAT GRBs and the large database of broadband observations collected by the Swift X-ray Telescope (XRT) and UV/Optical Telescope (UVOT). Through comparisons between the GRBs detected by Swift-BAT, G8M, and LAT, we can learn about the unique characteristics, physical differences, and the relationships between each population. These population characteristics provide insight into the different physical parameters that contribute to the diversity of observational GRB properties.

  13. Novel Technique for Monitoring the Performance of the LAT Instrument on Board the GLAST Satellite

    SciTech Connect

    Paneque, D.; Borgland, A.; Bovier, A.; Bloom, E.; Edmonds, Y.; Funk, S.; Godfrey, G.; Rando, R.; Wai, L.; Wang, P.

    2007-06-13

    The Gamma-ray Large Area Space Telescope (GLAST) is an observatory designed to perform gamma-ray astronomy in the energy range 20 MeV to 300 GeV, with supporting measurements for gamma-ray bursts from 10 keV to 25 MeV. GLAST will be launched at the end of 2007, opening a new and important window on a wide variety of high energy astrophysical phenomena . The main instrument of GLAST is the Large Area Telescope (LAT), which provides break-through high-energy measurements using techniques typically used in particle detectors for collider experiments. The LAT consists of 16 identical towers in a four-by-four grid, each one containing a pair conversion tracker and a hodoscopic crystal calorimeter, all covered by a segmented plastic scintillator anti-coincidence shield. The scientific return of the instrument depends very much on how accurately we know its performance, and how well we can monitor it and correct potential problems promptly. We report on a novel technique that we are developing to help in the characterization and monitoring of LAT by using the power of classification trees to pinpoint in a short time potential problems in the recorded data. The same technique could also be used to evaluate the effect on the overall LAT performance produced by potential instrumental problems.

  14. VizieR Online Data Catalog: Fermi LAT third source catalog (3FGL) (Acero+, 2015)

    NASA Astrophysics Data System (ADS)

    Acero, F.; Ackermann, M.; Ajello, M.; Albert, A.; Atwood, W. B.; Axelsson, M.; Baldini, L.; Ballet, J.; Barbiellini, G.; Bastieri, D.; Belfiore, A.; Bellazzini, R.; Bissaldi, E.; Blandford, R. D.; Bloom, E. D.; Bogart, J. R.; Bonino, R.; Bottacini, E.; Bregeon, J.; Britto, R. J.; Bruel, P.; Buehler, R.; Burnett, T. H.; Buson, S.; Caliandro, G. A.; Cameron, R. A.; Caputo, R.; Caragiulo, M.; Caraveo, P. A.; Casandjian, J. M.; Cavazzuti, E.; Charles, E.; Chaves, R. C. G.; Chekhtman, A.; Cheung, C. C.; Chiang, J.; Chiaro, G.; Ciprini, S.; Claus, R.; Cohen-Tanugi, J.; Cominsky, L. R.; Conrad, J.; Cutini, S.; D'Ammando, F.; de Angelis, A.; Deklotz, M.; de Palma, F.; Desiante, R.; Digel, S. W.; di Venere, L.; Drell, P. S.; Dubois, R.; Dumora, D.; Favuzzi, C.; Fegan, S. J.; Ferrara, E. C.; Finke, J.; Franckowiak, A.; Fukazawa, Y.; Funk, S.; Fusco, P.; Gargano, F.; Gasparrini, D.; Giebels, B.; Giglietto, N.; Giommi, P.; Giordano, F.; Giroletti, M.; Glanzman, T.; Godfrey, G.; Grenier, I. A.; Grondin, M.-H.; Grove, J. E.; Guillemot, L.; Guiriec, S.; Hadasch, D.; Harding, A. K.; Hays, E.; Hewitt, J. W.; Hill, A. B.; Horan, D.; Iafrate, G.; Jogler, T.; Johannesson, G.; Johnson, R. P.; Johnson, A. S.; Johnson, T. J.; Johnson, W. N.; Kamae, T.; Kataoka, J.; Katsuta, J.; Kuss, M.; La Mura, G.; Landriu, D.; Larsson, S.; Latronico, L.; Lemoine-Goumard, M.; Li, J.; Li, L.; Longo, F.; Loparco, F.; Lott, B.; Lovellette, M. N.; Lubrano, P.; Madejski, G. M.; Massaro, F.; Mayer, M.; Mazziotta, M. N.; McEnery, J. E.; Michelson, P. F.; Mirabal, N.; Mizuno, T.; Moiseev, A. A.; Mongelli, M.; Monzani, M. E.; Morselli, A.; Moskalenko, I. V.; Murgia, S.; Nuss, E.; Ohno, M.; Ohsugi, T.; Omodei, N.; Orienti, M.; Orlando, E.; Ormes, J. F.; Paneque, D.; Panetta, J. H.; Perkins, J. S.; Pesce-Rollins, M.; Piron, F.; Pivato, G.; Porter, T. A.; Racusin, J. L.; Rando, R.; Razzano, M.; Razzaque, S.; Reimer, A.; Reimer, O.; Reposeur, T.; Rochester, L. S.; Romani, R. W.; Salvetti, D.; Sanchez-Conde, M.; Saz Parkinson, P. M.; Schulz, A.; Siskind, E. J.; Smith, D. A.; Spada, F.; Spandre, G.; Spinelli, P.; Stephens, T. E.; Strong, A. W.; Suson, D. J.; Takahashi, H.; Takahashi, T.; Tanaka, Y.; Thayer J. G, .; Thayer, J. B.; Thompson, D. J.; Tibaldo, L.; Tibolla, O.; Torres, D. F.; Torresi, E.; Tosti, G.; Troja, E.; van Klaveren, B.; Vianello, G.; Winer, B. L.; Wood, K. S.; Wood, M.; Zimmer, S.

    2015-08-01

    The data for the 3FGL catalog were taken during the period from 2008 August 4 (15:43 UTC) to 2012 July 31 (22:46 UTC), to covering close to 4yr. The LAT detects γ-rays in the energy range from 20MeV to more than 300GeV. (3 data files).

  15. 2FHL: The Second Catalog of Hard Fermi-LAT Sources

    NASA Astrophysics Data System (ADS)

    Ackermann, M.; Ajello, M.; Atwood, W. B.; Baldini, L.; Ballet, J.; Barbiellini, G.; Bastieri, D.; Becerra Gonzalez, J.; Bellazzini, R.; Bissaldi, E.; Blandford, R. D.; Bloom, E. D.; Bonino, R.; Bottacini, E.; Brandt, T. J.; Bregeon, J.; Bruel, P.; Buehler, R.; Buson, S.; Caliandro, G. A.; Cameron, R. A.; Caputo, R.; Caragiulo, M.; Caraveo, P. A.; Cavazzuti, E.; Cecchi, C.; Charles, E.; Chekhtman, A.; Cheung, C. C.; Chiang, J.; Chiaro, G.; Ciprini, S.; Cohen, J. M.; Cohen-Tanugi, J.; Cominsky, L. R.; Conrad, J.; Cuoco, A.; Cutini, S.; D'Ammando, F.; de Angelis, A.; de Palma, F.; Desiante, R.; Di Mauro, M.; Di Venere, L.; Domínguez, A.; Drell, P. S.; Favuzzi, C.; Fegan, S. J.; Ferrara, E. C.; Focke, W. B.; Fortin, P.; Franckowiak, A.; Fukazawa, Y.; Funk, S.; Furniss, A. K.; Fusco, P.; Gargano, F.; Gasparrini, D.; Giglietto, N.; Giommi, P.; Giordano, F.; Giroletti, M.; Glanzman, T.; Godfrey, G.; Grenier, I. A.; Grondin, M.-H.; Guillemot, L.; Guiriec, S.; Harding, A. K.; Hays, E.; Hewitt, J. W.; Hill, A. B.; Horan, D.; Iafrate, G.; Hartmann, Dieter; Jogler, T.; Jóhannesson, G.; Johnson, A. S.; Kamae, T.; Kataoka, J.; Knödlseder, J.; Kuss, M.; La Mura, G.; Larsson, S.; Latronico, L.; Lemoine-Goumard, M.; Li, J.; Li, L.; Longo, F.; Loparco, F.; Lott, B.; Lovellette, M. N.; Lubrano, P.; Madejski, G. M.; Maldera, S.; Manfreda, A.; Mayer, M.; Mazziotta, M. N.; Michelson, P. F.; Mirabal, N.; Mitthumsiri, W.; Mizuno, T.; Moiseev, A. A.; Monzani, M. E.; Morselli, A.; Moskalenko, I. V.; Murgia, S.; Nuss, E.; Ohsugi, T.; Omodei, N.; Orienti, M.; Orlando, E.; Ormes, J. F.; Paneque, D.; Perkins, J. S.; Pesce-Rollins, M.; Petrosian, V.; Piron, F.; Pivato, G.; Porter, T. A.; Rainò, S.; Rando, R.; Razzano, M.; Razzaque, S.; Reimer, A.; Reimer, O.; Reposeur, T.; Romani, R. W.; Sánchez-Conde, M.; Saz Parkinson, P. M.; Schmid, J.; Schulz, A.; Sgrò, C.; Siskind, E. J.; Spada, F.; Spandre, G.; Spinelli, P.; Suson, D. J.; Tajima, H.; Takahashi, H.; Takahashi, M.; Takahashi, T.; Thayer, J. B.; Thompson, D. J.; Tibaldo, L.; Torres, D. F.; Tosti, G.; Troja, E.; Vianello, G.; Wood, K. S.; Wood, M.; Yassine, M.; Zaharijas, G.; Zimmer, S.

    2016-01-01

    We present a catalog of sources detected above 50 GeV by the Fermi-Large Area Telescope (LAT) in 80 months of data. The newly delivered Pass 8 event-level analysis allows the detection and characterization of sources in the 50 GeV-2 TeV energy range. In this energy band, Fermi-LAT has detected 360 sources, which constitute the second catalog of hard Fermi-LAT sources (2FHL). The improved angular resolution enables the precise localization of point sources (˜1.‧7 radius at 68% C. L.) and the detection and characterization of spatially extended sources. We find that 86% of the sources can be associated with counterparts at other wavelengths, of which the majority (75%) are active galactic nuclei and the rest (11%) are Galactic sources. Only 25% of the 2FHL sources have been previously detected by Cherenkov telescopes, implying that the 2FHL provides a reservoir of candidates to be followed up at very high energies. This work closes the energy gap between the observations performed at GeV energies by Fermi-LAT on orbit and the observations performed at higher energies by Cherenkov telescopes from the ground.

  16. Regulation of the human LAT gene by the Elf-1 transcription factor

    PubMed Central

    Finco, Timothy S; Justice-Healy, Geri E; Patel, Shivani J; Hamilton, Victoria E

    2006-01-01

    Background The LAT gene encodes an intracellular adaptor protein that links cell-surface receptor engagement to numerous downstream signalling events, and thereby plays an integral role in the function of cell types that express the gene, including T cells, mast cells, natural killer cells, and platelets. To date, the mechanisms responsible for the transcriptional regulation of this gene have not been investigated. Results In this study we have mapped the transcriptional start sites for the human LAT gene and localized the 5' and 3' boundaries of the proximal promoter. We find that the promoter contains both positive and negative regulatory regions, and that two binding sites for the Ets family of transcription factors have a strong, positive effect on gene expression. Each site binds the Ets family member Elf-1, and overexpression of Elf-1 augments LAT promoter activity. The promoter also contains a Runx binding site adjacent to one of the Ets sites. This site, which is shown to bind Runx-1, has an inhibitory effect on gene expression. Finally, data is also presented indicating that the identified promoter may regulate cell-type specific expression. Conclusion Collectively, these results provide the first insights into the transcriptional regulation of the LAT gene, including the discovery that the Ets transcription factor Elf-1 may play a central role in its expression. PMID:16464244

  17. Fermi LAT Gamma-ray Observations of IceCube-160731

    NASA Astrophysics Data System (ADS)

    Cheung, C. C.; Toomey, M. W.; Kocevski, D.; Buson, S.

    2016-08-01

    We report follow-up of the extremely high-energy (EHE) IceCube-160731 neutrino event (AMON GCN notice; http://gcn.gsfc.nasa.gov/notices_amon/6888376_128290.amon) with all-sky survey data from the Large Area Telescope (LAT), on board the Fermi Gamma-ray Space Telescope.

  18. FERMI-LAT SEARCH FOR PULSAR WIND NEBULAE AROUND GAMMA-RAY PULSARS

    SciTech Connect

    Ackermann, M.; Ajello, M.; Bechtol, K.; Berenji, B.; Bloom, E. D.; Borgland, A. W.; Bouvier, A.; Buehler, R.; Baldini, L.; Bellazzini, R.; Bregeon, J.; Brez, A.; Ballet, J.; Bastieri, D.; Buson, S.; Bonamente, E.; Brigida, M.; Bruel, P.

    2011-01-01

    The high sensitivity of the Fermi-LAT (Large Area Telescope) offers the first opportunity to study faint and extended GeV sources such as pulsar wind nebulae (PWNe). After one year of observation the LAT detected and identified three PWNe: the Crab Nebula, Vela-X, and the PWN inside MSH 15-52. In the meantime, the list of LAT detected pulsars increased steadily. These pulsars are characterized by high energy loss rates ( E-dot ) from {approx}3 x 10{sup 33} erg s{sup -1} to 5 x 10{sup 38} erg s{sup -1} and are therefore likely to power a PWN. This paper summarizes the search for PWNe in the off-pulse windows of 54 LAT-detected pulsars using 16 months of survey observations. Ten sources show significant emission, seven of these likely being of magnetospheric origin. The detection of significant emission in the off-pulse interval offers new constraints on the {gamma}-ray emitting regions in pulsar magnetospheres. The three other sources with significant emission are the Crab Nebula, Vela-X, and a new PWN candidate associated with the LAT pulsar PSR J1023-5746, coincident with the TeV source HESS J1023-575. We further explore the association between the HESS and the Fermi source by modeling its spectral energy distribution. Flux upper limits derived for the 44 remaining sources are used to provide new constraints on famous PWNe that have been detected at keV and/or TeV energies.

  19. Dephosphorylation of the adaptor LAT and phospholipase C-γ by SHP-1 inhibits natural killer cell cytotoxicity.

    PubMed

    Matalon, Omri; Fried, Sophia; Ben-Shmuel, Aviad; Pauker, Maor H; Joseph, Noah; Keizer, Danielle; Piterburg, Marina; Barda-Saad, Mira

    2016-01-01

    Natural killer (NK) cells discriminate between healthy cells and virally infected or transformed self-cells by tuning activating and inhibitory signals received through cell surface receptors. Inhibitory receptors inhibit NK cell function by recruiting and activating the tyrosine phosphatase Src homology 2 (SH2) domain-containing protein tyrosine phosphatase-1 (SHP-1) to the plasma membrane. However, to date, the guanine nucleotide exchange factor VAV1 is the only direct SHP-1 substrate identified in NK cells. We reveal that the adaptor protein linker for activation of T cells (LAT) as well as phospholipase C-γ1 (PLC-γ1) and PLC-γ2 are SHP-1 substrates. Dephosphorylation of Tyr(132) in LAT by SHP-1 in NK cells abrogated the recruitment of PLC-γ1 and PLC-γ2 to the immunological synapse between the NK cell and a cancer cell target, which reduced NK cell degranulation and target cell killing. Furthermore, the ubiquitylation of LAT by the E3 ubiquitin ligases c-Cbl and Cbl-b, which was induced by LAT phosphorylation, led to the degradation of LAT in response to the engagement of inhibitory receptors on NK cells, which abrogated NK cell cytotoxicity. Knockdown of the Cbl proteins blocked LAT ubiquitylation, which promoted NK cell function. Expression of a ubiquitylation-resistant mutant LAT blocked inhibitory receptor signaling, enabling cells to become activated. Together, these data identify previously uncharacterized SHP-1 substrates and inhibitory mechanisms that determine the response of NK cells.

  20. VizieR Online Data Catalog: The second Fermi-LAT >50GeV catalog (2FHL) (Ackermann+, 2016)

    NASA Astrophysics Data System (ADS)

    Ackermann, M.; Ajello, M.; Atwood, W. B.; Baldini, L.; Ballet, J.; Barbiellini, G.; Bastieri, D.; Becerra Gonzalez, J.; Bellazzini, R.; Bissaldi, E.; Blandford, R. D.; Bloom, E. D.; Bonino, R.; Bottacini, E.; Brandt, T. J.; Bregeon, J.; Bruel, P.; Buehler, R.; Buson, S.; Caliandro, G. A.; Cameron, R. A.; Caputo, R.; Caragiulo, M.; Caraveo, P. A.; Cavazzuti, E.; Cecchi, C.; Charles, E.; Chekhtman, A.; Cheung, C. C.; Chiang, J.; Chiaro, G.; Ciprini, S.; Cohen, J. M.; Cohen-Tanugi, J.; Cominsky, L. R.; Conrad, J.; Cuoco, A.; Cutini, S.; D'Ammando, F.; de Angelis, A.; de Palma, F.; Desiante, R.; di Mauro, M.; di Venere, L.; Dominguez, A.; Drell, P. S.; Favuzzi, C.; Fegan, S. J.; Ferrara, E. C.; Focke, W. B.; Fortin, P.; Franckowiak, A.; Fukazawa, Y.; Funk, S.; Furniss, A. K.; Fusco, P.; Gargano, F.; Gasparrini, D.; Giglietto, N.; Giommi, P.; Giordano, F.; Giroletti, M.; Glanzman, T.; Godfrey, G.; Grenier, I. A.; Grondin, M.-H.; Guillemot, L.; Guiriec, S.; Harding, A. K.; Hays, E.; Hewitt, J. W.; Hill, A. B.; Horan, D.; Iafrate, G.; Hartmann, D.; Jogler, T.; Johannesson, G.; John Son, A. S.; Kamae, T.; Kataoka, J.; Knodlseder, J.; Kuss, M.; La Mura, G.; Larsson, S.; Latronico, L.; Lemoine-Goumard, M.; Li, J.; Li, L.; Longo, F.; Loparco, F.; Lott, B.; Lovellette, M. N.; Lubrano, P.; Madejski, G. M.; Maldera, S.; Manfreda, A.; Mayer, M.; Mazziotta, M. N.; Michelson, P. F.; Mirabal, N.; Mitthumsiri, W.; Mizuno, T.; Moiseev, A. A.; Monzani, M. E.; Morselli, A.; Moskalenko, I. V.; Murgia, S.; Nuss, E.; Ohsugi, T.; Omodei, N.; Orienti, M.; Orlando, E.; Ormes, J. F.; Paneque, D.; Perkins, J. S.; Pesce-Rollins, M.; Petrosian, V.; Piron, F.; Pivato, G.; Porter, T. A.; Raino, S.; Rando, R.; Razzano, M.; Razzaque, S.; Reimer, A.; Reimer, O.; Reposeur, T.; Romani, R. W.; Sanchez-Conde, M.; Parkinson, P. M. S.; Schmid, J.; Schulz, A.; Sgro, C.; Siskind, E. J.; Spada, F.; Spandre, G.; Spinelli, P.; Suson, D. J.; Tajima, H.; Takahashi, H.; Takahashi, M.; Takahashi, T.; Thayer, J. B.; Thompson, D. J.; Tibaldo, L.; Torres, D. F.; Tosti, G.; Troja, E.; Vianello, G.; Wood, K. S.; Wood, M.; Yassine, M.; Zaharijas, G.; Zimmer, S.

    2016-02-01

    The Large Area Telescope (LAT) on board the Fermi gamma-ray space telescope has been surveying the whole sky since 2008 August. In this paper we use 80 months of Pass 8 data to produce a catalog of sources detected by the LAT at energies between 50GeV and 2TeV. This constitutes the second catalog of hard Fermi-LAT sources, named 2FHL, which allows a thorough study of the properties of the whole sky in the sub-TeV domain. (4 data files).

  1. Immunoglobulin-Mediated Agglutination of and Biofilm Formation by Escherichia coli K-12 Require the Type 1 Pilus Fiber

    PubMed Central

    Orndorff, Paul E.; Devapali, Aditya; Palestrant, Sarah; Wyse, Aaron; Everett, Mary Lou; Bollinger, R. Randal; Parker, William

    2004-01-01

    The binding of human secretory immunoglobulin A (SIgA), the primary immunoglobulin in the gut, to Escherichia coli is thought to be dependent on type 1 pili. Type 1 pili are filamentous bacterial surface attachment organelles comprised principally of a single protein, the product of the fimA gene. A minor component of the pilus fiber (the product of the fimH gene, termed the adhesin) mediates attachment to a variety of host cell molecules in a mannose inhibitable interaction that has been extensively described. We found that the aggregation of E. coli K-12 by human secretory IgA (SIgA) was dependent on the presence of the pilus fiber, even in the absence of the mannose specific adhesin or in the presence of 25 mM α-CH3Man. The presence of pilus without adhesin also facilitated SIgA-mediated biofilm formation on polystyrene, although biofilm formation was stronger in the presence of the adhesin. IgM also mediated aggregation and biofilm formation in a manner dependent on pili with or without adhesin. These findings indicate that the pilus fiber, even in the absence of the adhesin, may play a role in biologically important processes. Under conditions in which E. coli was agglutinated by SIgA, the binding of SIgA to E. coli was not increased by the presence of the pili, with or without adhesin. This observation suggests that the pili, with or without adhesin, affect factors such as cell surface rigidity or electrostatic repulsion, which can affect agglutination but which do not necessarily determine the level of bound immunoglobulin. PMID:15039312

  2. 21 CFR 606.151 - Compatibility testing.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... identification. (b) The use of fresh recipient serum or plasma samples less than 3 days old for all...) Procedures to demonstrate incompatibility between the donor's cell type and the recipient's serum or plasma... demonstrate agglutinating, coating and hemolytic antibodies, the recipient's cells shall be tested with...

  3. New Results on High Energy Cosmic Ray Electrons Observed with Fermi LAT and Their Implications on the Models of Pulsars

    NASA Technical Reports Server (NTRS)

    Moiseev, Alexander

    2010-01-01

    This viewgraph presentation describes, in detail, the Fermi Large Area Telescope (LAT) and GLAST Burst Monitor (GBM). Observations made from the June 11, 2008 launch and a discussion of observations made of high energy cosmic ray electrons is also presented.

  4. Fermi-LAT Gamma-Ray Detections of Classical Novae V1369 Centauri 2013 and V5668 Sagittarii 2015

    NASA Astrophysics Data System (ADS)

    Cheung, C. C.; Jean, P.; Shore, S. N.; Stawarz, Ł.; Corbet, R. H. D.; Knödlseder, J.; Starrfield, S.; Wood, D. L.; Desiante, R.; Longo, F.; Pivato, G.; Wood, K. S.

    2016-08-01

    We report the Fermi Large Area Telescope (LAT) detections of high-energy (>100 MeV) γ-ray emission from two recent optically bright classical novae, V1369 Centauri 2013 and V5668 Sagittarii 2015. At early times, Fermi target-of-opportunity observations prompted by their optical discoveries provided enhanced LAT exposure that enabled the detections of γ-ray onsets beginning ˜2 days after their first optical peaks. Significant γ-ray emission was found extending to 39-55 days after their initial LAT detections, with systematically fainter and longer-duration emission compared to previous γ-ray-detected classical novae. These novae were distinguished by multiple bright optical peaks that encompassed the time spans of the observed γ-rays. The γ-ray light curves and spectra of the two novae are presented along with representative hadronic and leptonic models, and comparisons with other novae detected by the LAT are discussed.

  5. Fermi LAT detection of a new high-energy transient gamma-ray source Fermi J0751-5136

    NASA Astrophysics Data System (ADS)

    Kocevski, D.; Buson, S.

    2016-08-01

    During the week from 18 July through 25 July, 2016, the Large Area Telescope (LAT), one of the two instruments on the Fermi Gamma-ray Space Telescope, observed gamma-ray activity from a previously unidentified transient source.

  6. Fermi-LAT Gamma-Ray Detections of Classical Novae V1369 Centauri 2013 and V5668 Sagittarii 2015

    NASA Astrophysics Data System (ADS)

    Cheung, C. C.; Jean, P.; Shore, S. N.; Stawarz, Ł.; Corbet, R. H. D.; Knödlseder, J.; Starrfield, S.; Wood, D. L.; Desiante, R.; Longo, F.; Pivato, G.; Wood, K. S.

    2016-08-01

    We report the Fermi Large Area Telescope (LAT) detections of high-energy (>100 MeV) γ-ray emission from two recent optically bright classical novae, V1369 Centauri 2013 and V5668 Sagittarii 2015. At early times, Fermi target-of-opportunity observations prompted by their optical discoveries provided enhanced LAT exposure that enabled the detections of γ-ray onsets beginning ˜2 days after their first optical peaks. Significant γ-ray emission was found extending to 39–55 days after their initial LAT detections, with systematically fainter and longer-duration emission compared to previous γ-ray-detected classical novae. These novae were distinguished by multiple bright optical peaks that encompassed the time spans of the observed γ-rays. The γ-ray light curves and spectra of the two novae are presented along with representative hadronic and leptonic models, and comparisons with other novae detected by the LAT are discussed.

  7. Properties of Streptococcus mutans Grown in a Synthetic Medium: Binding of Glucosyltransferase and In Vitro Adherence, and Binding of Dextran/Glucan and Glycoprotein and Agglutination

    PubMed Central

    Wu-Yuan, Christine D.; Tai, Stella; Slade, Hutton D.

    1979-01-01

    The influence of culture media on various properties of Streptococcus mutans was investigated. Strains of S. mutans (serotypes c, d, f, and g) were grown in a complex medium (Todd-Hewitt broth [THB]) or a synthetic medium (SYN). The SYN cells, in contrast to THB cells, did not bind extracellular glucosyltransferase and did not produce in vitro adherence. Both types of cells possessed constitutive levels of glucosyltransferase. B13 cells grown in SYN plus invertase-treated glucose possessed the same level of constitutive enzyme as THB cells. In contrast to THB cells, the SYN cells of seven serotype strains did not agglutinate upon the addition of high-molecular-weight dextran/glucan. Significant quantities of lower-molecular-weight (2 × 104 or 7 × 104) dextran and B13 glucan were bound by SYN cells. SYN cells agglutinated weakly in anti-glucan serum (titers, 0 to 16), whereas THB cells possessed titers of 32 to 256. Evidence for the existence of a second binding site in agglutination which does not possess a glucan-like polymer has been obtained. B13 cells grown in invertase-treated THB agglutinated to the same degree as normal THB cells. The nature of this site is unknown. SYN cells possess the type-specific polysaccharide antigen. B13 cells did not bind from THB a glycoprotein which reacts with antisera to the A, B, or T blood group antigens or which allows agglutination upon the addition of dextran. The results demonstrate that S. mutans grown in a chemically defined medium possesse markedly different biochemical and biological activities than cells grown in a complex organic medium. PMID:457252

  8. Detection of 16 gamma-ray pulsars through blind frequency searches using the Fermi LAT.

    PubMed

    Abdo, A A; Ackermann, M; Ajello, M; Anderson, B; Atwood, W B; Axelsson, M; Baldini, L; Ballet, J; Barbiellini, G; Baring, M G; Bastieri, D; Baughman, B M; Bechtol, K; Bellazzini, R; Berenji, B; Bignami, G F; Blandford, R D; Bloom, E D; Bonamente, E; Borgland, A W; Bregeon, J; Brez, A; Brigida, M; Bruel, P; Burnett, T H; Caliandro, G A; Cameron, R A; Caraveo, P A; Casandjian, J M; Cecchi, C; Celik, O; Chekhtman, A; Cheung, C C; Chiang, J; Ciprini, S; Claus, R; Cohen-Tanugi, J; Conrad, J; Cutini, S; Dermer, C D; de Angelis, A; de Luca, A; de Palma, F; Digel, S W; Dormody, M; do Couto e Silva, E; Drell, P S; Dubois, R; Dumora, D; Farnier, C; Favuzzi, C; Fegan, S J; Fukazawa, Y; Funk, S; Fusco, P; Gargano, F; Gasparrini, D; Gehrels, N; Germani, S; Giebels, B; Giglietto, N; Giommi, P; Giordano, F; Glanzman, T; Godfrey, G; Grenier, I A; Grondin, M-H; Grove, J E; Guillemot, L; Guiriec, S; Gwon, C; Hanabata, Y; Harding, A K; Hayashida, M; Hays, E; Hughes, R E; Jóhannesson, G; Johnson, R P; Johnson, T J; Johnson, W N; Kamae, T; Katagiri, H; Kataoka, J; Kawai, N; Kerr, M; Knödlseder, J; Kocian, M L; Kuss, M; Lande, J; Latronico, L; Lemoine-Goumard, M; Longo, F; Loparco, F; Lott, B; Lovellette, M N; Lubrano, P; Madejski, G M; Makeev, A; Marelli, M; Mazziotta, M N; McConville, W; McEnery, J E; Meurer, C; Michelson, P F; Mitthumsiri, W; Mizuno, T; Monte, C; Monzani, M E; Morselli, A; Moskalenko, I V; Murgia, S; Nolan, P L; Norris, J P; Nuss, E; Ohsugi, T; Omodei, N; Orlando, E; Ormes, J F; Paneque, D; Parent, D; Pelassa, V; Pepe, M; Pesce-Rollins, M; Pierbattista, M; Piron, F; Porter, T A; Primack, J R; Rainò, S; Rando, R; Ray, P S; Razzano, M; Rea, N; Reimer, A; Reimer, O; Reposeur, T; Ritz, S; Rochester, L S; Rodriguez, A Y; Romani, R W; Ryde, F; Sadrozinski, H F-W; Sanchez, D; Sander, A; Saz Parkinson, P M; Scargle, J D; Sgrò, C; Siskind, E J; Smith, D A; Smith, P D; Spandre, G; Spinelli, P; Starck, J-L; Strickman, M S; Suson, D J; Tajima, H; Takahashi, H; Takahashi, T; Tanaka, T; Thayer, J G; Thompson, D J; Tibaldo, L; Tibolla, O; Torres, D F; Tosti, G; Tramacere, A; Uchiyama, Y; Usher, T L; Van Etten, A; Vasileiou, V; Vilchez, N; Vitale, V; Waite, A P; Wang, P; Watters, K; Winer, B L; Wolff, M T; Wood, K S; Ylinen, T; Ziegler, M

    2009-08-14

    Pulsars are rapidly rotating, highly magnetized neutron stars emitting radiation across the electromagnetic spectrum. Although there are more than 1800 known radio pulsars, until recently only seven were observed to pulse in gamma rays, and these were all discovered at other wavelengths. The Fermi Large Area Telescope (LAT) makes it possible to pinpoint neutron stars through their gamma-ray pulsations. We report the detection of 16 gamma-ray pulsars in blind frequency searches using the LAT. Most of these pulsars are coincident with previously unidentified gamma-ray sources, and many are associated with supernova remnants. Direct detection of gamma-ray pulsars enables studies of emission mechanisms, population statistics, and the energetics of pulsar wind nebulae and supernova remnants. PMID:19574346

  9. Identifying Unidentified Fermi-LAT Objects (UFOs) at High-Latitude

    NASA Astrophysics Data System (ADS)

    Cheung, Chi Teddy

    2009-09-01

    We propose a Chandra study of 8 high Galactic latitude gamma-ray sources in the Fermi-LAT bright source list. These sources are currently unidentified, i.e., they are not clearly associated with established classes of gamma-ray emitters like blazars and pulsars. The proposed observations will determine the basic properties (fluxes, positions, hardness ratio/spectra) of all X-ray sources down to a 0.3-10 keV flux limit of 1.5e-14 erg/cm2/s within the Fermi-LAT localization circles. This will enable further follow-up at other wavelengths, with the ultimate goal to reveal the nature of these enigmatic gamma-ray sources.

  10. Fermi LAT Results and Perspectives in Measurements of High Energy Galactic Cosmic Rays

    NASA Technical Reports Server (NTRS)

    Moiseev, Alexander

    2010-01-01

    Real breakthrough during last 1-1.5 years in cosmic ray electrons: ATIC, HESS, Pamela, and finally Fermi-LAT. New quality data have made it possible to start quantitative modeling. With the new data more puzzles than before on CR electrons origin. Need "multi-messenger" campaign: electrons, positrons, gammas, X-ray, radio, neutrino... It is viable that we are dealing with at least two distinct mechanisms of "primary" electron (both signs) production: a softer spectrum of negative electrons, and a harder spectrum of both e(+)+e(-). Exotic (e.g. DM) origin is not ruled out. Upper limits on CR electrons anisotropy are set. Good perspectives to have the Fermi LAT results on proton spectrum and positron fraction.

  11. Fermi-LAT confirmation of enhanced gamma-ray activity from the Crab nebula

    NASA Astrophysics Data System (ADS)

    Cheung, C. C.

    2016-10-01

    Preliminary LAT analysis confirms the recent enhanced gamma-ray activity from the Crab nebula detected by AGILE (ATel #9586). The daily-averaged gamma-ray fluxes (E > 100 MeV) from the direction of the Crab Nebula were (4.8 +/- 0.5) x 10^-6 ph cm^-2 s^-1 (Sep 30), (3.3 +/- 0.4) x 10^-6 ph cm^-2 s^-1 (Oct 1), and (4.5 +/- 0.5) x 10^-6 ph cm^-2 s^-1 (Oct 2). These are up to a factor of ~1.8 greater than the average gamma-ray flux of (2.71 +/- 0.02) x 10^-6 ph cm^-2 s^-1 reported in the third Fermi-LAT source catalog (Acero et al. 2015, ApJS, 218, 23). All fluxes given are the sums of the pulsar and nebular emission, and with statistical uncertainties only.

  12. LAT gel, a powerful tool underused in the repair of paediatric lacerations.

    PubMed

    Wang, B; Hill, V K P; Wilson, M H; Felstead, A M

    2014-08-01

    Paediatric lacerations presenting to emergency departments are a common cause of referral to surgical specialties in the UK. LAT gel (lidocaine, adrenaline, and tetracaine) is a safe and effective topical anaesthetic that can aid with the closure of uncomplicated lacerations, particularly in the paediatric trauma setting. The benefits to both the patient and management in terms of the avoidance of a general anaesthetic and the freeing up of hospital resources (e.g. beds, staffing, emergency theatre) make it an invaluable tool in the arsenal of the emergency department. The authors describe a reliable method of anaesthetizing lacerations with LAT gel and question its underuse within the emergency departments in the South West region of the UK. PMID:24861471

  13. A Fermi/LAT Trigger of Grating Observations of One Bright Nova in Outburst

    NASA Astrophysics Data System (ADS)

    Starrfield, Sumner

    2013-09-01

    A new and perplexing result in 2012 was the discovery by the Fermi/LAT that two Classical Novae (Mon 2012 and Sco 2012) were emitting gamma-rays at E > 100 MeV. The cause of this VHE emission is currently not understood but X-ray grating observations early in the outburst should shed light on the cause. We propose to obtain 2 grating spectra with Chandra of one bright CN in outburst. Our target will be determined based on a detection by the Fermi/Large Area Telescope (LAT), a confirmation by ground-based spectroscopy that it is a CN, and a Swift/XRT determination that it is sufficiently bright for an HETG+ACIS-S grating observation. A second spectrum will be obtained with the LETG+HRC-S when the nova has transitioned into the Super Soft Source phase.

  14. Comparative evaluation of gel column agglutination and erythrocyte magnetized technology for red blood cell alloantibody titration.

    PubMed

    Dubey, Anju; Sonker, Atul; Chaudhary, Rajendra K

    2015-01-01

    Antibody titration is traditionally performed using a conventional test tube (CTT) method, which is subjected to interlaboratory variations because of a lack of standardization and reproducibility. The aim of this study is to compare newer methods such as get column technology (GCT) and erythrocyte magnetized technology (EMT) for antibody titration in terms of accuracy and precision. Patient serum samples that contained immunoglobin G (IgG) red blood cell (RBC) alloantibodies of a single specificity for Rh or K anitgens were identified during routine transfusion service testing and stored. Titration and scoring were performed separately by and stored. Titration and scoring were performed separately by different laboratory personnel on CTT, GCT, and EMT. Testing was performed a total of three times on each sample. Results were analyzed for accuracy and precision. A total of 50 samples were tested. Only 20 percent of samples tested with GCT shoed titers identical to CTT, whereas 48 percent of samples tested with EMT showed titers identical to CTT. Overall, the mean of th titer difference from CTT was higher using GCT (+0.31) compared with that using EMT (+0.13). Precision shown by CTT was 30 percent, EMT was 76 percent, and GCT was 92 percent on repeat testing. GCT showed higher titer values in comparison with CTT but was found to be the most precise. EMT titers were comparable to CTT, and its precision was intermediate. Further studies to validate this method are required.

  15. Fermi-LAT upper limits on gamma-ray emission from colliding wind binaries

    NASA Astrophysics Data System (ADS)

    Werner, M.; Reimer, O.; Reimer, A.; Egberts, K.

    2013-07-01

    Context. Colliding wind binaries (CWBs) are thought to give rise to a plethora of physical processes including acceleration and interaction of relativistic particles. Observation of synchrotron radiation in the radio band confirms there is a relativistic electron population in CWBs. Accordingly, CWBs have been suspected sources of high-energy γ-ray emission since the COS-B era. Theoretical models exist that characterize the underlying physical processes leading to particle acceleration and quantitatively predict the non-thermal energy emission observable at Earth. Aims: We strive to find evidence of γ-ray emission from a sample of seven CWB systems: WR 11, WR 70, WR 125, WR 137, WR 140, WR 146, and WR 147. Theoretical modelling identified these systems as the most favourable candidates for emitting γ-rays. We make a comparison with existing γ-ray flux predictions and investigate possible constraints. Methods: We used 24 months of data from the Large Area Telescope (LAT) on-board the Fermi Gamma Ray Space Telescope to perform a dedicated likelihood analysis of CWBs in the LAT energy range. Results: We find no evidence of γ-ray emission from any of the studied CWB systems and determine corresponding flux upper limits. For some CWBs the interplay of orbital and stellar parameters renders the Fermi -LAT data not sensitive enough to constrain the parameter space of the emission models. In the cases of WR140 and WR147, the Fermi -LAT upper limits appear to rule out some model predictions entirely and constrain theoretical models over a significant parameter space. A comparison of our findings to the CWB η Car is made.

  16. Recent Evidence for Gamma-ray Line Emission from Fermi-LAT: WIMP or Artifact?

    NASA Astrophysics Data System (ADS)

    Su, Meng; Finkbeiner, D. P.

    2013-04-01

    The recent claims of a gamma-ray line in the Galactic center at 130 GeV have generated excitement, not least because it could be a signal of dark matter annihilation. I will summarize the current state of the observations of the Galactic center, clusters, and unassociated halo objects. I will also speculate about models of particle dark matter that could explain the data, and possible systematic of the Fermi-LAT instrument that might contaminate the line detection.

  17. Fermi LAT detection of renewed and strong GeV activity from blazar 3C 279

    NASA Astrophysics Data System (ADS)

    Cutini, Sara

    2015-06-01

    The Large Area Telescope (LAT), one of two instruments on the Fermi Gamma-ray Space Telescope, has observed an intense gamma-ray flare from a source positionally consistent with the flat spectrum radio quasar 3C 279, also known as 3FGL J1256.1-0547 (Acero et al. 2015, APJS, 218, 23), with radio coordinates R.A.: 194.0465271 deg, Dec: -5.7893119 deg (J2000.0; Johnston et al. 1995, AJ, 110, 880).

  18. Fermi LAT observations of PSR J1119-6127 before and after its recent bursts

    NASA Astrophysics Data System (ADS)

    Tam, P. H. Thomas

    2016-08-01

    We report on the Fermi LAT observations of PSR J1119-6127, a rotation-powered pulsar with high magnetic field that showed two magnetar-like bursts on 2016-07-27 13:02:07.91 UT and 2016-07-28 01:27:51 UT, recorded by the Fermi GBM and Swift BAT instruments, respectively (Kennea et al., GCN Circ. 19735/ATel #9274; Younes et al., GCN Circ. 19736).

  19. Fermi LAT detection of a GeV flare from 4C +01.02

    NASA Astrophysics Data System (ADS)

    Buson, S.

    2013-09-01

    The Large Area Telescope (LAT), one of the two instruments on the Fermi Gamma-ray Space Telescope, observed a gamma-ray outburst from a source positionally consistent with the flat spectrum radio quasar 4C +01.02, also known as BZQ J0108+0135 (RA: 01h08m38.8s DEC : +01d35m00s, J2000.0, Kenneth et al. 1995) with redshift z=2.099 (Hewett et al. 1995).

  20. Time Stretching of the GeV Emission of GRBs: Fermi-LAT Data versus Geometrical Model

    NASA Astrophysics Data System (ADS)

    Piskunov, Maxim S.; Rubtsov, Grigory I.

    2016-06-01

    It is known that the high-energy (\\gt 100 {MeV}) emission of gamma-ray bursts is delayed with respect to the low-energy emission. However, the dependence of light curves on energy has not been studied for the high-energy bands. In this paper, we consider the bursts observed by Fermi LAT from 2008 August 4 to 2011 August 1, for which at least 10 photons were observed with energy greater than 1 {GeV}. These include four bursts: GRB 080916C, GRB 090510, GRB 090902B, and GRB 090926A. We use the Kolmogorov-Smirnov test to compare the light curves in the two bands 100 {MeV}\\lt E\\lt 1 {GeV} and E\\gt 1 {GeV}. For GRB 080916C and GRB 090510 the light curves in the two bands are statistically compatible. However, for GRB 090926A, the higher-energy light curve is stretched compared to the lower-energy one with a statistical significance of 3.3σ and, for GRB 090902B, on the contrary, the lower-energy curve is stretched with 2.3σ significance. We argue that the observed diversity of stretching factors may be explained using a simple geometrical model. The model assumes that the jet opening angle depends on the emission energy in a way that the most energetic photons are radiated near the axis of the jet. All of the bursts are considered equivalent in their rest frames, and the observed light curves differ only due to different redshifts and view directions. The model conforms to the total burst energy constraint and matches the Fermi-LAT observations of the fraction of GRBs visible in the 100 {MeV}\\lt E\\lt 1 {GeV} band, which may be observed at higher energies. The model predicts the distribution of observable stretching factors, which may be tested in future data. Finally, we propose a method to estimate the observer's off-axis angle based on the stretching factor and the fraction of the high-energy photons. The code for modeling is open source and is publicly available on GitHub (https://github.com/maxitg/GammaRays).

  1. Afterglow Population Studies from Swift Follow-Up Observations of Fermi LAT GRBs

    NASA Technical Reports Server (NTRS)

    Racusin, Judith L.; Oates, S. R.; McEnery, J.; Vasileiou, V.; Troja, E.; Gehrels, N.

    2010-01-01

    The small population of Fermi LAT detected GRBs discovered over the last year has been providing interesting and unexpected clues into GRB prompt and afterglow emission mechanisms. Over the last 5 years, it has been Swift that has provided the robust data set of UV/optical and X-ray afterglow observations that opened many windows into other components of GRB emission structure. We explore the new ability to utilize both of these observatories to study the same GRBs over 10 orders of magnitude in energy, although not always concurrently. Almost all LAT GRBs that have been followed-up by Swift within 1-day have been clearly detected and carefully observed. We will present the context of the lower-energy afterglows of this special subset of GRBs that has > 100 MeV emission compared to the hundreds in the Swift database that may or may not have been observed by LAT, and theorize upon the relationship between these properties and the origin of the high energy gamma-ray emission.

  2. Resolving the hadronic accelerator IC 443 with Fermi-LAT and VERITAS

    NASA Astrophysics Data System (ADS)

    Hewitt, John W.; Hays, Elizabeth A.; Tajima, Hiro; Schmid, Julia; LAT Collaboration, VERITAS Collaboration

    2016-01-01

    Supernova remnants (SNRs) close to molecular clouds are ideal astrophysical laboratories to study cosmic ray acceleration and injection into the Galaxy. The Galactic SNR IC 443 is among the brightest and best-studied of such systems, detected as an extended gamma-ray source at both GeV and TeV energies. Previous observations with the AGILE and Fermi-LAT gamma-ray space telescopes have shown a low-energy cutoff at <200 MeV indicating relativistic protons are responsible for gamma-ray emission. Observations by the MAGIC and VERITAS ground-based gamma-ray telescopes show a steepening spectrum at TeV energies. Now, with updated Fermi-LAT observations using 7 yr of Pass 8 data above 1 GeV, the gamma-ray morphology of IC 443 is revealed as an inhomogeneous shell. Multi-wavelength observations have mapped the detailed physical conditions across the interaction site between the SNR and cloud, allowing us to separately study gamma-ray emission regions on scales less than 10 pc. We find an excellent correlation between GeV gamma-rays and the TeV morphology determined by VERITAS. The combination of new VERITAS and Fermi-LAT observations of IC 443 allows an unprecedented study of the environmental dependence of cosmic-ray diffusion in and around a hadronic accelerator.

  3. Cap and trade schemes on waste management: A case study of the Landfill Allowance Trading Scheme (LATS) in England

    SciTech Connect

    Calaf-Forn, Maria; Roca, Jordi; Puig-Ventosa, Ignasi

    2014-05-01

    Highlights: • LATS has been effective to achieve a reduction of the amount of landfilled waste. • LATS has been one of the few environmental instruments for waste management with a cap and trade methodology. • LATS has achieved to increase recycling of the biodegradable and other waste fractions. - Abstract: The Landfill Allowance Trading Scheme (LATS) is one of the main instruments used in England to enforce the landfill diversion targets established in the Directive 1999/31/EC of the European Parliament and of the Council of 26 April 1999 on the landfill of waste (Landfill Directive). Through the LATS, biodegradable municipal waste (BMW) allowances for landfilling are allocated to each local authority, otherwise known as waste disposal authorities (WDAs). The quantity of landfill allowances received is expected to decrease continuously from 2005/06 to 2019/20 so as to meet the objectives of the Landfill Directive. To achieve their commitments, WDAs can exchange, buy, sell or transfer allowances among each other, or may re-profile their own allocation through banking and/or borrowing. Despite the goals for the first seven years – which included two target years (2005/06 and 2009/10) – being widely achieved (the average allocation of allowances per WDA was 22.9% higher than those finally used), market activity among WDAs was high and prices were not very stable. Results in terms of waste reduction and recycling levels have been satisfactory. The reduction of BMW landfilled (in percentage) was higher during the first seven years of the LATS period (2005/06–2011/12) (around 7% annually) than during the previous period (2001/02–2004/05) (4.2% annually). Since 2008, the significance of the LATS diminished because of an increase in the rate of the UK Landfill Tax. The LATS was suppressed after the 2012/13 target year, before what it was initially scheduled. The purpose of this paper is to describe the particularities of the LATS, analyse its performance as

  4. HIGH-FREQUENCY RADIO PROPERTIES OF SOURCES IN THE FERMI-LAT 1 YEAR POINT SOURCE CATALOG

    SciTech Connect

    Mahony, Elizabeth K.; Sadler, Elaine M.; Murphy, Tara; Ekers, Ronald D.; Edwards, Philip G.; Massardi, Marcella

    2010-08-01

    The high-frequency radio sky, like the gamma-ray sky surveyed by the Fermi satellite, is dominated by flat spectrum radio quasars and BL Lac objects at bright flux levels. To investigate the relationship between radio and gamma-ray emission in extragalactic sources, we have cross-matched the Australia Telescope 20 GHz survey catalog (AT20G) with the Fermi-LAT 1 year Point Source Catalog (1FGL). The 6.0 sr of sky covered by both catalogs ({delta} < 0{sup 0}, |b|>1.{sup 0}5) contains 5890 AT20G radio sources and 604 1FGL gamma-ray sources. The AT20G source positions are accurate to within {approx}1 arcsec and, after excluding known Galactic sources, 43% of Fermi 1FGL sources have an AT20G source within the 95% Fermi confidence ellipse. Monte Carlo tests imply that at least 95% of these matches are genuine associations. Only five gamma-ray sources (1% of the Fermi catalog) have more than one AT20G counterpart in the Fermi error box. The AT20G matches also generally support the active galactic nucleus (AGN) associations in the First LAT AGN Catalog. We find a trend of increasing gamma-ray flux density with 20 GHz radio flux density. The Fermi detection rate of AT20G sources is close to 100% for the brightest 20 GHz sources, decreasing to 20% at 1 Jy, and to roughly 1% at 100 mJy. Eight of the matched AT20G sources have no association listed in 1FGL and are presented here as potential gamma-ray AGNs for the first time. We also identify an alternative AGN counterpart to one 1FGL source. The percentage of Fermi sources with AT20G detections decreases toward the Galactic plane, suggesting that the 1FGL catalog contains at least 50 Galactic gamma-ray sources in the southern hemisphere that are yet to be identified.

  5. Cap and trade schemes on waste management: a case study of the landfill allowance trading scheme (LATS) in England.

    PubMed

    Calaf-Forn, Maria; Roca, Jordi; Puig-Ventosa, Ignasi

    2014-05-01

    The Landfill Allowance Trading Scheme (LATS) is one of the main instruments used in England to enforce the landfill diversion targets established in the Directive 1999/31/EC of the European Parliament and of the Council of 26 April 1999 on the landfill of waste (Landfill Directive). Through the LATS, biodegradable municipal waste (BMW) allowances for landfilling are allocated to each local authority, otherwise known as waste disposal authorities (WDAs). The quantity of landfill allowances received is expected to decrease continuously from 2005/06 to 2019/20 so as to meet the objectives of the Landfill Directive. To achieve their commitments, WDAs can exchange, buy, sell or transfer allowances among each other, or may re-profile their own allocation through banking and/or borrowing. Despite the goals for the first seven years - which included two target years (2005/06 and 2009/10) - being widely achieved (the average allocation of allowances per WDA was 22.9% higher than those finally used), market activity among WDAs was high and prices were not very stable. Results in terms of waste reduction and recycling levels have been satisfactory. The reduction of BMW landfilled (in percentage) was higher during the first seven years of the LATS period (2005/06-2011/12) (around 7% annually) than during the previous period (2001/02-2004/05) (4.2% annually). Since 2008, the significance of the LATS diminished because of an increase in the rate of the UK Landfill Tax. The LATS was suppressed after the 2012/13 target year, before what it was initially scheduled. The purpose of this paper is to describe the particularities of the LATS, analyse its performance as a waste management policy, make a comparison with the Landfill Tax, discuss its main features as regards efficiency, effectiveness and the application of the "polluter pays" principle and finally discuss if the effect of the increase in the Landfill Tax is what made the LATS ultimately unnecessary.

  6. Imaging the L-Type Amino Acid Transporter-1 (LAT1) with Zr-89 ImmunoPET

    PubMed Central

    Ikotun, Oluwatayo F.; Marquez, Bernadette V.; Huang, Chaofeng; Masuko, Kazue; Daiji, Miyamoto; Masuko, Takashi; McConathy, Jonathan; Lapi, Suzanne E.

    2013-01-01

    The L-type amino acid transporter-1 (LAT1, SLC7A5) is upregulated in a wide range of human cancers, positively correlated with the biological aggressiveness of tumors, and a promising target for both imaging and therapy. Radiolabeled amino acids such as O-(2-[18F]fluoroethyl)-L-tyrosine (FET) that are transport substrates for system L amino acid transporters including LAT1 have met limited success for oncologic imaging outside of the brain, and thus new strategies are needed for imaging LAT1 in systemic cancers. Here, we describe the development and biological evaluation of a novel zirconium-89 labeled antibody, [89Zr]DFO-Ab2, targeting the extracellular domain of LAT1 in a preclinical model of colorectal cancer. This tracer demonstrated specificity for LAT1 in vitro and in vivo with excellent tumor imaging properties in mice with xenograft tumors. PET imaging studies showed high tumor uptake, with optimal tumor-to-non target contrast achieved at 7 days post administration. Biodistribution studies demonstrated tumor uptake of 10.5 ± 1.8 percent injected dose per gram (%ID/g) at 7 days with a tumor to muscle ratio of 13 to 1. In contrast, the peak tumor uptake of the radiolabeled amino acid [18F]FET was 4.4 ± 0.5 %ID/g at 30 min after injection with a tumor to muscle ratio of 1.4 to 1. Blocking studies with unlabeled anti-LAT1 antibody demonstrated a 55% reduction of [89Zr]DFO-Ab2 accumulation in the tumor at 7 days. These results are the first report of direct PET imaging of LAT1 and demonstrate the potential of immunoPET agents for imaging specific amino acid transporters. PMID:24143237

  7. A zebrafish intelectin ortholog agglutinates both Gram-negative and Gram-positive bacteria with binding capacity to bacterial polysaccharide.

    PubMed

    Chen, Lei; Yan, Jie; Sun, Weiping; Zhang, Yan; Sui, Chao; Qi, Jing; Du, Yijun; Feng, Lijun

    2016-08-01

    Intelectins are glycan-binding lectins found in various species including cephalochordates, urochordates, fish, amphibians and mammals. But their detailed functions are not well studied in zebrafish which is a good model to study native immunity. In this study, we cloned a zebrafish intelectin ortholog, zebrafish intelectin 2 (zITLN2), which contains a conserved fibrinogen-related domain (FReD) in the N-terminus and the unique intelectin domain in the C-terminus. We examined the tissue distribution of zITLN2 in adult zebrafish and found that zITLN2 was expressed in various organs with the highest level in intestine. Like amphioxus intelectins, zITLN2 expression was upregulated in adult zebrafish infected with Staphylococcus aureus with the highest expression level at 12 h after challenge. Recombinant zITLN2 protein expressed in E. coli was able to agglutinate both Gram-negative and Gram-positive bacteria to similar degrees in a calcium-dependent manner. Furthermore, recombinant zITLN2 bound lipopolysaccharide (LPS) and peptidoglycan (PGN) comparably. Our work on zITLN2 provided further information to understand functions of this new family of lectins and the innate immunity in vertebrates. PMID:27329687

  8. Tectonic significance of magnetic and gravity data across northern California (lat. 39[degree]N. to lat. 41[degree]N. )

    SciTech Connect

    Griscom, A.; Roberts, C.W.; Halvorson, P.F. )

    1993-04-01

    Aeromagnetic and isostatic residual gravity maps of an east-west transect across northern California show important tectonic features. A linear magnetic anomaly and west-sloping gradient extends over 300 km along the Franciscan-Great Valley contact (FGC) and across the Klamath Mountains province (KM) north to lat. 40[degree]45'N. The anomaly source lies at depths of 5--10 km beneath the KM and the FGC, and implies that the Franciscan complex of the Coast Ranges is thrust (and wedged) at least 80 km eastward beneath the KM to approximately long. 122[degree]40 minutes W. Calculations on a circular gravity low of [minus]50 mGal centered at the circular Bald Rock pluton (diameter about 15 km) in the Sierran foothills indicate a pluton thickness of about 15 km. The nearby Cascade and Merrimac plutons are located on the gradients of this gravity anomaly, have a relatively minor effect on it, and thus are interpreted to be thick (up to 5 km) laccolithic sills that emanate from the Bald Rock pluton, thinning away from it to a feather edge. Model studies indicate that the northeast contact of the Feather River periodotite body (FRPB) north of lat. 39[degree]40 minutes N. generally dips steeply northeast or vertical. The same contact south of this latitude dips east at angles of about 45[degree] to depths of at least 10 km. Magnetic patterns extending from the northern Sierra across the Cascades to the Klamath Mountains suggest that the FRPB may correlate with the Trinity ophiolite.

  9. Rapid Effects of a Protective O-Polysaccharide-Specific Monoclonal IgA on Vibrio cholerae Agglutination, Motility, and Surface Morphology

    PubMed Central

    Levinson, Kara J.; De Jesus, Magdia

    2015-01-01

    2D6 is a dimeric monoclonal immunoglobulin A (IgA) specific for the nonreducing terminal residue of Ogawa O-polysaccharide (OPS) of Vibrio cholerae. It was previously demonstrated that 2D6 IgA is sufficient to passively protect suckling mice from oral challenge with virulent V. cholerae O395. In this study, we sought to define the mechanism by which 2D6 IgA antibody protects the intestinal epithelium from V. cholerae infection. In a mouse ligated-ileal-loop assay, 2D6 IgA promoted V. cholerae agglutination in the intestinal lumen and limited the ability of the bacteria to associate with the epithelium, particularly within the crypt regions. In vitro fluorescence digital video microscopy analysis of antibody-treated V. cholerae in liquid medium revealed that 2D6 IgA not only induced the rapid (5- to 10-min) onset of agglutination but was an equally potent inhibitor of bacterial motility. Scanning electron microscopy showed that 2D6 IgA promoted flagellum-flagellum cross-linking, as well as flagellar entanglement with bacterial bodies, suggesting that motility arrest may be a consequence of flagellar tethering. However, monovalent 2D6 Fab fragments also inhibited V. cholerae motility, demonstrating that antibody-mediated agglutination and motility arrest are separate phenomena. While 2D6 IgA is neither bactericidal nor bacteriostatic, exposure of V. cholerae to 2D6 IgA (or Fab fragments) resulted in a 5-fold increase in surface-associated blebs, as well an onset of a wrinkled surface morphotype. We propose that the protective immunity conferred by 2D6 IgA is the result of multifactorial effects on V. cholerae, including agglutination, motility arrest, and possibly outer membrane stress. PMID:25667263

  10. Prevalence of agglutinating antibodies to Toxoplasma gondii in striped skunks (Mephitis mephitis), opossums (Didelphis virginiana), and raccoons (Procyon lotor) from Connecticut.

    PubMed

    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.

  11. Mutation of the phospholipase C-gamma1-binding site of LAT affects both positive and negative thymocyte selection.

    PubMed

    Sommers, Connie L; Lee, Jan; Steiner, Kevin L; Gurson, Jordan M; Depersis, Corinne L; El-Khoury, Dalal; Fuller, Claudette L; Shores, Elizabeth W; Love, Paul E; Samelson, Lawrence E

    2005-04-01

    Linker for activation of T cells (LAT) is a scaffolding adaptor protein that is critical for T cell development and function. A mutation of LAT (Y136F) that disrupts phospholipase C-gamma1 activation and subsequent calcium influx causes a partial block in T cell development and leads to a severe lymphoproliferative disease in homozygous knock-in mice. One possible contribution to the fatal disease of LAT Y136F knock-in mice could be from autoreactive T cells generated in these mice because of altered thymocyte selection. To examine the impact of the LAT Y136F mutation on thymocyte positive and negative selection, we bred this mutation onto the HY T cell receptor (TCR) transgenic, recombination activating gene-2 knockout background. Female mice with this genotype showed a severe defect in positive selection, whereas male mice exhibited a phenotype resembling positive selection (i.e., development and survival of CD8(hi) HY TCR-specific T cells) instead of negative selection. These results support the hypothesis that in non-TCR transgenic, LAT Y136F knock-in mice, altered thymocyte selection leads to the survival and proliferation of autoreactive T cells that would otherwise be negatively selected in the thymus.

  12. Lab-on-a-disc agglutination assay for protein detection by optomagnetic readout and optical imaging using nano- and micro-sized magnetic beads.

    PubMed

    Uddin, Rokon; Burger, Robert; Donolato, Marco; Fock, Jeppe; Creagh, Michael; Hansen, Mikkel Fougt; Boisen, Anja

    2016-11-15

    We present a biosensing platform for the detection of proteins based on agglutination of aptamer coated magnetic nano- or microbeads. The assay, from sample to answer, is integrated on an automated, low-cost microfluidic disc platform. This ensures fast and reliable results due to a minimum 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 25pM with the same sample-to-answer time (15min 30s) using the two differently sized beads for the two detection methods. In both cases a sample volume of only 10µl is required. The demonstrated automation, low sample-to-answer time and portability of both detection instruments as well as integration of the assay on a low-cost disc are important steps for the implementation of these as portable tools in an out-of-lab setting.

  13. Lab-on-a-disc agglutination assay for protein detection by optomagnetic readout and optical imaging using nano- and micro-sized magnetic beads.

    PubMed

    Uddin, Rokon; Burger, Robert; Donolato, Marco; Fock, Jeppe; Creagh, Michael; Hansen, Mikkel Fougt; Boisen, Anja

    2016-11-15

    We present a biosensing platform for the detection of proteins based on agglutination of aptamer coated magnetic nano- or microbeads. The assay, from sample to answer, is integrated on an automated, low-cost microfluidic disc platform. This ensures fast and reliable results due to a minimum 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 25pM with the same sample-to-answer time (15min 30s) using the two differently sized beads for the two detection methods. In both cases a sample volume of only 10µl is required. The demonstrated automation, low sample-to-answer time and portability of both detection instruments as well as integration of the assay on a low-cost disc are important steps for the implementation of these as portable tools in an out-of-lab setting. PMID:27183287

  14. Agglutinating mouse IgG3 compares favourably with IgMs in typing of the blood group B antigen: Functionality and stability studies

    PubMed Central

    Klaus, Tomasz; Bzowska, Monika; Kulesza, Małgorzata; Kabat, Agnieszka Martyna; Jemioła-Rzemińska, Małgorzata; Czaplicki, Dominik; Makuch, Krzysztof; Jucha, Jarosław; Karabasz, Alicja; Bereta, Joanna

    2016-01-01

    Mouse immunoglobulins M (IgMs) that recognize human blood group antigens induce haemagglutination and are used worldwide for diagnostic blood typing. Contrary to the current belief that IgGs are too small to simultaneously bind antigens on two different erythrocytes, we obtained agglutinating mouse IgG3 that recognized antigen B of the human ABO blood group system. Mouse IgG3 is an intriguing isotype that has the ability to form Fc-dependent oligomers. However, F(ab′)2 fragments of the IgG3 were sufficient to agglutinate type B red blood cells; therefore, IgG3-triggered agglutination did not require oligomerization. Molecular modelling indicated that mouse IgG3 has a larger range of Fab arms than other mouse IgG subclasses and that the unique properties of mouse IgG3 are likely due to the structure of its hinge region. With a focus on applications in diagnostics, we compared the stability of IgG3 and two IgMs in formulated blood typing reagents using an accelerated storage approach and differential scanning calorimetry. IgG3 was much more stable than IgMs. Interestingly, the rapid decrease in IgM activity was caused by aggregation of the molecules and a previously unknown posttranslational proteolytic processing of the μ heavy chain. Our data point to mouse IgG3 as a potent diagnostic tool. PMID:27484487

  15. Agglutinating mouse IgG3 compares favourably with IgMs in typing of the blood group B antigen: Functionality and stability studies.

    PubMed

    Klaus, Tomasz; Bzowska, Monika; Kulesza, Małgorzata; Kabat, Agnieszka Martyna; Jemioła-Rzemińska, Małgorzata; Czaplicki, Dominik; Makuch, Krzysztof; Jucha, Jarosław; Karabasz, Alicja; Bereta, Joanna

    2016-01-01

    Mouse immunoglobulins M (IgMs) that recognize human blood group antigens induce haemagglutination and are used worldwide for diagnostic blood typing. Contrary to the current belief that IgGs are too small to simultaneously bind antigens on two different erythrocytes, we obtained agglutinating mouse IgG3 that recognized antigen B of the human ABO blood group system. Mouse IgG3 is an intriguing isotype that has the ability to form Fc-dependent oligomers. However, F(ab')2 fragments of the IgG3 were sufficient to agglutinate type B red blood cells; therefore, IgG3-triggered agglutination did not require oligomerization. Molecular modelling indicated that mouse IgG3 has a larger range of Fab arms than other mouse IgG subclasses and that the unique properties of mouse IgG3 are likely due to the structure of its hinge region. With a focus on applications in diagnostics, we compared the stability of IgG3 and two IgMs in formulated blood typing reagents using an accelerated storage approach and differential scanning calorimetry. IgG3 was much more stable than IgMs. Interestingly, the rapid decrease in IgM activity was caused by aggregation of the molecules and a previously unknown posttranslational proteolytic processing of the μ heavy chain. Our data point to mouse IgG3 as a potent diagnostic tool. PMID:27484487

  16. Concanavalin A-mediated agglutination and distribution of concanavalin A-binding sites in Acanthamoeba following treatment with colchicine and cytochalasin B.

    PubMed

    Paatero, G; Isomaa, B; Ranninen, T; Wessberg, S

    1983-01-01

    Incubation of Acanthamoeba castellanii (Neff strain) with FITC-ConA (15 micrograms/ml) resulted in the appearance of patches of fluorescence on the amoebae within 2 min of incubation. These patches disappeared following treatment of the amoebae with alpha-MeMan. Pretreatment of the amoebae with colchicine or cytochalasin B or with colchicine and cytochalasin B in combination did not significantly alter the distribution pattern of fluorescence in the amoebae. 2,4-Dinitrophenol and incubation at 4 degrees C on the other hand decreased the degree of patching of the amoebae. Pretreatment with 2,4-dinitrophenol and incubation at 4 degrees C also decreased the ConA-mediated agglutination of the amoebae. No effect on the ConA-mediated agglutination was, however, observed following pretreatment of the amoebae with colchicine and cytochalasin B neither alone nor in combination. Our results indicate that ConA-mediated agglutination and long-range ConA-receptor mobility in the Acanthamoeba are not under the control of structures sensitive to cytochalasin B or colchicine. PMID:6682041

  17. Fermi-LAT observations of supernova remnants Kesteven 79

    SciTech Connect

    Auchettl, Katie; Slane, Patrick; Castro, Daniel

    2014-03-01

    In this paper, we report on the detection of γ-ray emission coincident with the Galactic supernova remnant (SNR) Kesteven 79 (Kes 79). We analyzed approximately 52 months of data obtained with the Large Area Telescope on board the Fermi Gamma-ray Space Telescope. Kes 79 is thought to be interacting with adjacent molecular clouds, based on the presence of strong {sup 12}CO J = 1 → 0 and HCO{sup +} J = 1 → 0 emission and the detection of 1720 MHz line emission toward the east of the remnant. Acceleration of cosmic rays is expected to occur at SNR shocks, and SNRs interacting with dense molecular clouds provide a good testing ground for detecting and analyzing the production of γ-rays from the decay of π{sup 0} into two γ-ray photons. This analysis investigates γ-ray emission coincident with Kes 79, which has a detection significance of ∼7σ. Additionally, we present an investigation of the spatial and spectral characteristics of Kes 79 using multiple archival XMM-Newton observations of this remnant. We determine the global X-ray properties of Kes 79 and estimate the ambient density across the remnant. We also performed a similar analysis for Galactic SNR Kesteven 78 (Kes 78), but due to large uncertainties in the γ-ray background model, no conclusion can be made about an excess of GeV γ-ray associated with the remnant.

  18. Gamma-telescopes Fermi/LAT and GAMMA-400 Trigger Systems Event Recognizing Methods Comparison

    NASA Astrophysics Data System (ADS)

    Arkhangelskaja, I. V.; Murchenko, A. E.; Chasovikov, E. N.; Arkhangelskiy, A. I.; Kheymits, M. D.

    Usually instruments for high-energy γ-quanta registration consists of converter (where γ-quanta produced pairs) and calorimeter for particles energy measurements surrounded by anticoincidence shield used to events identification (whether incident particle was charged or neutral). The influence of pair formation by γ-quanta in shield and the backsplash (moved in the opposite direction particles created due high energy γ-rays interact with calorimeter) should be taken into account. It leads to decrease both effective area and registration efficiency at E>10 GeV. In the presented article the event recognizing methods used in Fermi/LAT trigger system is considered in comparison with the ones applied in counting and triggers signals formation system of gamma-telescope GAMMA-400. The GAMMA-400 (Gamma Astronomical Multifunctional Modular Apparatus) will be the new high-apogee space γ-observatory. The GAMMA-400 consist of converter-tracker based on silicon-strip coordinate detectors interleaved with tungsten foils, imaging calorimeter make of 2 layers of double (x, y) silicon strip coordinate detectors interleaved with planes of CsI(Tl) crystals and the electromagnetic calorimeter CC2 consists only of CsI(Tl) crystals. Several plastics detections systems used as anticoincidence shield, for particles energy and moving direction estimations. The main differences of GAMMA-400 constructions from Fermi/LAT one are using the time-of-flight system with base of 50 cm and double layer structure of plastic detectors provides more effective particles direction definition and backsplash rejection. Also two calorimeters in GAMMA-400 composed the total absorbtion spectrometer with total thickness ∼ 25 X0 or ∼1.2 λ0 for vertical incident particles registration and 54 X0 or 2.5 λ0 for laterally incident ones (where λ0 is nuclear interaction length). It provides energy resolution 1-2% for 10 GeV-3.0×103 GeV events while the Fermi/LAT energy resolution does not reach such a

  19. Involvement of the L-Type Amino Acid Transporter Lat2 in the Transport of 3,3'-Diiodothyronine across the Plasma Membrane.

    PubMed

    Kinne, Anita; Wittner, Melanie; Wirth, Eva K; Hinz, Katrin M; Schülein, Ralf; Köhrle, Josef; Krause, Gerd

    2015-09-01

    Thyroid hormones are transported across cell membranes by transmembrane transporter proteins, for example by members of the monocarboxylate transporter (MCT) and the L-type amino acid transporter (LAT) families. LATs consist of a light chain (e.g. LAT2) and a heavy chain (CD98), which is essential for their cell surface expression and functionality. The specificity of Lat2 for thyroid hormones and their metabolites and its role in their transport was not fully clear. This fact motivated us to establish a cell system to elucidate the uptake of thyroid hormones and their metabolites by mouse Lat2. The coinjection of cRNA coding for Lat2 and CD98 into Xenopus laevis oocytes resulted in a markedly increased level of 3,3'-diiodo-L-thyronine (3,3'-T2) and to some extent also enhanced T3 transport. To gain insight into properties of thyroid hormones and their metabolites transported by Lat2, we inhibited 3,3'-T2 uptake by various iodothyronine derivatives. T1 and T2 derivatives as well as 2-aminobicyclo-[2, 2,1]-heptane-2-carboxylic acid strongly competed with 3,3'-T2 uptake. In addition, we performed T2 uptake measurements with the thyroid hormone-specific transporter MCT8. For both Lat2 and MCT8, Km values in a low micromolar range were calculated. We demonstrated that oocytes are a suitable system for thyroid hormone transport studies mediated by Lat2. Our data indicates that Lat2 compared to other thyroid hormone transporters prefers 3,3'-T2 as the substrate. Thus, Lat2 might contribute to the availability of thyroid hormone by importing and/or exporting 3,3'-T2, which is generated either by T3 inactivation or by rapid deiodinase 1-mediated rT3 degradation. PMID:26601072

  20. Differentiation of Helicobacter pylori Isolates Based on Lectin Binding of Cell Extracts in an Agglutination Assay

    PubMed Central

    Hynes, Sean O.; Hirmo, Siiri; Wadström, Torkel; Moran, Anthony P.

    1999-01-01

    Plant and animal lectins with various carbohydrate specificities were used to type 35 Irish clinical isolates of Helicobacter pylori and the type strain NCTC 11637 in a microtiter plate assay. Initially, a panel of eight lectins with the indicated primary specificities were used: Anguilla anguilla (AAA), Lotus tetragonolobus (Lotus A), and Ulex europaeus I (UEA I), specific for α-l-fucose; Solanum tuberosum (STA) and Triticum vulgaris (WGA), specific for β-N-acetylglucosamine; Glycine max (SBA), specific for β-N-acetylgalactosamine; Erythrina cristagali (ECA), specific for β-galactose and β-N-acetylgalactosamine; and Lens culinaris (LCA), specific for α-mannose and α-glucose. Three of the lectins (SBA, STA, and LCA) were not useful in aiding in strain discrimination. An optimized panel of five lectins (AAA, ECA, Lotus A, UEA I, and WGA) grouped all 36 strains tested into eight lectin reaction patterns. For optimal typing, pretreatment by washing bacteria with a low-pH buffer to allow protein release, followed by proteolytic degradation to eliminate autoagglutination, was used. Lectin types of treated samples were stable and reproducible. No strain proved to be untypeable by this system. Electrophoretic and immunoblotting analyses of lipopolysaccharides (LPSs) indicated that the lectins interact primarily, but not solely, with the O side chain of H. pylori LPS. PMID:10325361

  1. Fermi-LAT detection of a GeV flare from blazar TXS 0646-176

    NASA Astrophysics Data System (ADS)

    Ciprini, Stefano

    2015-07-01

    The Large Area Telescope (LAT), one of the two instruments on the Fermi Gamma-ray Space Telescope, has observed increasing gamma-ray flux from a source positionally consistent with the flat spectrum radio quasar TXS 0646-176 , also known as MRC 0646-176 and 3FGL J0648.8-1740, with radio counterpart position R.A.: 102.11874 deg, -17.73484 deg, (J2000.0, Petrov et al. 2006, AJ, 131, 1872 ) and with redshift z=1.232 (Hewitt & Burbidge 1993, ApJS, 87, 451).

  2. Fermi LAT detection of increase gamma-ray emission from OJ 248

    NASA Astrophysics Data System (ADS)

    Orienti, M.; D'Ammando, F.

    2012-09-01

    The Large Area Telescope (LAT), on board the Fermi Gamma-ray Space Telescope, has observed gamma-ray flaring activity from a source positionally consistent with the flat spectrum radio quasar OJ 248 (also known as 2FGL J0830.5+2407, Nolan et al. 2012, ApJS, 199, 31) with radio coordinates R.A.: 127.7170254 deg, Dec: 24.1832836 deg (J2000, Johnston et al. 1995, AJ, 110, 880) at redshift z=0.94 (Hewitt & Burbidge 1993, ApJS, 87, 451).

  3. VizieR Online Data Catalog: The first Fermi LAT SNR catalog (1SC) (Acero+, 2016)

    NASA Astrophysics Data System (ADS)

    Acero, F.; Ackermann, M.; Ajello, M.; Baldini, L.; Ballet, J.; Barbiellini, G.; Bastieri, D.; Bellazzini, R.; Bissaldi, E.; Blandford, R. D.; Bloom, E. D.; Bonino, R.; Bottacini, E.; Brandt, T. J.; Bregeon, J.; Bruel, P.; Buehler, R.; Buson, S.; Caliandro, G. A.; Cameron, R. A.; Caputo, R.; Caragiulo, M.; Caraveo, P. A.; Casandjian, J. M.; Cavazzuti, E.; Cecchi, C.; Chekhtman, A.; Chiang, J.; Chiaro, G.; Ciprini, S.; Claus, R.; Cohen, J. M.; Cohen-Tanugi, J.; Cominsky, L. R.; Condon, B.; Conrad, J.; Cutini, S.; D'Ammando, F.; de Angelis, A.; de Palma, F.; Desiante, R.; Digel, S. W.; di Venere, L.; Drell, P. S.; Drlica-Wagner, A.; Favuzzi, C.; Ferrara, E. C.; Franckowiak, A.; Fukazawa, Y.; Funk, S.; Fusco, P.; Gargano, F.; Gasparrini, D.; Giglietto, N.; Giommi, P.; Giordano, F.; Giroletti, M.; Glanzman, T.; Godfrey, G.; Gomez-Vargas, G. A.; Grenier, I. A.; Grondin, M.-H.; Guillemot, L.; Guiriec, S.; Gustafsson, M.; Hadasch, D.; Harding, A. K.; Hayashida, M.; Hays, E.; Hewitt, J. W.; Hill, A. B.; Horan, D.; Hou, X.; Iafrate, G.; Jogler, T.; Johannesson, G.; Johnson!, A. S.; Ka, Mae T.; Katagiri, H.; Kataoka, J.; Katsuta, J.; Kerr, M.; Knodlseder, J.; Kocevski, D.; Kuss, M.; Laffon, H.; Lande, J.; Larsson, S.; Latronico, L.; Lemoine-Goumard, M.; Li, J.; Li, L.; Longo, F.; Loparco, F.; Lovellette, M. N.; Lubrano, P.; Magill, J.; Maldera, S.; Marelli, M.; Mayer, M.; Mazziotta, M. N.; Michelson, P. F.; Mitthumsiri, W.; Mizuno, T.; Moiseev, A. A.; Monzani, M. E.; Moretti, E.; Morselli, A.; Moskalenko, I. V.; Murgia, S.; Nemmen, R.; Nuss, E.; Ohsugi, T.; Omodei, N.; Orienti, M.; Orlando, E.; Ormes, J. F.; Paneque, D.; Perkins, J. S.; Pesce-Rollins, M.; Petrosian, V.; Piron, F.; Pivato, G.; Porter, T. A.; Raino, S.; Rando, R.; Razzano, M.; Razzaque, S.; Reimer, A.; Reimer, O.; Renaud, M.; Reposeur, T.; Rousseau, R.; Saz Parkinson, P. M.; Schmid, J.; Schulz, A.; Sgro, C.; Siskind, E. J.; Spada, F.; Spandre, G.; Spinelli, P.; Strong, A. W.; Suson, D. J.; Tajima, H.; Takahashi, H.; Tanaka, T.; Thayer, J. B.; Thompson, D. J.; Tibaldo, L.; Tibolla, O.; Torres, D. F.; Tosti, G.; Troja, E.; Uchiyama, Y.; Vianello, G.; Wells, B.; Wood, K. S.; Wood, M.; Yassine, M.; Den Hartog P. R.; Zimmer, S.

    2016-06-01

    We have systematically characterized the Fermi/LAT 1-100GeV emission from 36 months (from 2008 August 4 to 2011 August 4) in 279 regions containing known radio SNRs, identifying sources emitting in the regions and then determining the likelihood that the source nearest the SNR is associated with it. We found 102 candidates, 30 of which have sufficient spatial overlap and significance with the alternative IEMs to suggest they are the GeV counterparts to their corresponding radio SNRs and an additional 14 candidates which may also be related to the SNRs. (3 data files).

  4. Fermi LAT detection of increasing gamma-ray activity of blazar OJ 287

    NASA Astrophysics Data System (ADS)

    Escande, L.; Schinzel, F. K.

    2011-10-01

    The Large Area Telescope (LAT), one of the two instruments on the Fermi Gamma-ray Space Telescope, has observed an increasing gamma-ray flux from a source positionally consistent with the optically bright BL Lac object OJ 287 (RA: 08h 54m 48.874s , Dec: +20d 06m 30.64s, J2000.0, Johnston et al. 1995, AJ, 110, 880) at z=0.306 (Falomo, Scarpa, & Bersanelli 1994, ApJS, 93, 125; Sitko & Junkkarinen 1985, PASP, 97, 1158).

  5. Fermi-LAT Detection of a Gamma-ray Flare from Cygnus X-3

    NASA Astrophysics Data System (ADS)

    Cheung, C. C.; Loh, Alan

    2016-09-01

    The Large Area Telescope (LAT), one of the two instruments on the Fermi Gamma-ray Space Telescope, has observed a gamma-ray flare from the high-mass X-ray binary Cygnus X-3. Preliminary analysis indicates that on 2016 September 15 and 16, the gamma-ray source was observed with respective daily averaged fluxes (E > 100MeV) of (2.2+/-0.4) x 10^-6 photons cm^-2 s^-1 and (2.8+/-0.4) x 10^-6 photons cm^-2 s^-1 (errors are statistical only).

  6. Fermi LAT and Swift flare of the FSRQ 4C +40.25

    NASA Astrophysics Data System (ADS)

    Carpenter, Bryce; Ojha, Roopesh; Pivato, Giovanna; Fermi Large Area Telescope Collaboration

    2015-11-01

    The Large Area Telescope (LAT) on board the Fermi Gamma-ray Space Telescope has observed a gamma-ray flare from a source positionally consistent with the flat spectrum radio quasar (FSRQ) 4C +40.25 (also known as B2 1020+40 and 3FGL J1023.1+3952, Acero et al. 2015, ApJS 218, 23) with coordinates RA: 10h 23m 11.5661s, Dec: 39d 48m 15.378s, J2000, (Helmboldt et al. 2007, ApJ, 658, 203) and a redshift of 1.254 (Xu et al. 1994, AJ, 108, 395).

  7. Fermi LAT Detection of a Gamma-ray Flare from the BL Lac Object ON 246

    NASA Astrophysics Data System (ADS)

    Becerra, Josefa

    2015-06-01

    The Large Area Telescope (LAT) on board the Fermi Gamma-ray Space Telescope has observed increasing gamma-ray flux from a source positionally consistent with the BL Lac object ON 246 (RA=187.55871 deg, Dec=25.30198 deg, J2000, Beasley et al. 2002, ApJS, 141, 13; with redshift z=0.135, Nass et al. 1996, A&A, 309, 419), also known as S3 1227+25 and 3FGL J1230.3+2519 (3FGL; Acero et al. 2015, arXiv:1501.02003).

  8. Fermi-LAT detection of strong flaring activity from the FSRQ CTA 102

    NASA Astrophysics Data System (ADS)

    Becerra, J.; Carpenter, Bryce; Cutini, Sara

    2016-02-01

    The Large Area Telescope (LAT) on board the Fermi Gamma-ray Space Telescope has observed increasing gamma-ray activity from a source positionally consistent with the flat spectrum radio quasar CTA 102 (also known as 3FGL J2232.5+1143, Acero et al. 2015, ApJS, 218, 23) with radio coordinates R.A.: 338.1517038 deg, Dec: 11.7308067 deg (J2000, Johnston et al. 1995, AJ, 110, 880) at redshift z=1.037 (Schmidt 1965, ApJ, 141, 1295).

  9. Fermi LAT detection of renewed activity from the blazar PKS 1502+106

    NASA Astrophysics Data System (ADS)

    Ciprini, Stefano

    2015-06-01

    The Large Area Telescope (LAT), one of two instruments on the Fermi Gamma-ray Space Telescope, has observed increasing gamma-ray flux from a source positionally consistent with the flat spectrum radio quasar PKS 1502+106 (also known as OR 103, S3 1502+10 and 3FGL J1504.4+1029, Acero et al., arXiv:1501.02003), with radio coordinates, (J2000.0), R.A.: 226.10408 deg, Dec: 10.49422 deg (Johnston et al. 1995, AJ, 110, 880). This blazar has a redshift of z=1.8383 (Hewett & Wild 2010, MNRAS, 405, 2302).

  10. Fermi LAT Detection of a Rapid, Powerful Gamma-ray Flare of the FSRQ CTA 102

    NASA Astrophysics Data System (ADS)

    Carpenter, Bryce; Ojha, Roopesh

    2015-12-01

    The Large Area Telescope (LAT) on board the Fermi Gamma-ray Space Telescope has observed increasing gamma-ray flux from a source positionally consistent with the flat spectrum radio quasar CTA 102 (also known as 3FGL J2232.5+1143, Acero et al. 2015, ApJS, 218, 23) with radio coordinates R.A.: 338.1517038 deg, Dec: 11.7308067 deg (J2000, Johnston et al. 1995, AJ, 110, 880) at redshift z=1.037 (Schmidt 1965, ApJ, 141, 1295).

  11. Fermi LAT detection of a GeV flare from PKS 1124-186

    NASA Astrophysics Data System (ADS)

    Allafort, A.

    2011-03-01

    The Large Area Telescope (LAT), one of the two instruments on the Fermi Gamma-ray Space Telescope, has observed an increasing gamma-ray flux from a source positionally consistent with the flat spectrum radio quasar PKS 1124-186, also known as CGRaBS J1127-1857 and 1FGL J1126.8-1854 (RA=11h27m04.3924s, DEC=-18d57m17.440s, J2000; Johnston et al. 1995, AJ, 110, 880). The source is located at redshift z=1.048 (Drinkwater et al.

  12. Fermi LAT detection of a GeV flare from PKS 0235-618

    NASA Astrophysics Data System (ADS)

    Cutini, Sara

    2010-06-01

    The Large Area Telescope (LAT), one of the two instruments on the Fermi Gamma-ray Space Telescope, has observed an increasing gamma-ray flux from 1FGL J0238.3-6132 (Abdo, A. et al 2010, ApJ, 715, 429) a source positionally consistent with the Flat Spectrum Radio Quasar PKS 0235-618 (RA: 02h36m53.2457s DEC: -61d36m15.183, J2000, Fey, A. et al. 2004, AJ, 127, 1791) with a redshift of z=0.465 (Healey, S.

  13. Leser-Trélat Sign in Tumor-Stage Mycosis Fungoides.

    PubMed

    Rowe, Brandon; Shevchenko, Alina; Yosipovitch, Gil

    2016-01-01

    A 71-year-old man presented with numerous pruritic seborrheic keratoses, with an eruptive onset over the course of 3 months. At presentation, he was also found to have hypopigmented tumors diffusely scattered throughout his body that were found to be mycosis fungoides on histologic examination. A theory regarding the pathophysiology of the development of eruptive seborrheic keratoses in the presence of mycosis fungoides is briefly discussed and 10 previous case reports of the Leser-Trélat sign in the setting of mycosis fungoides are reviewed.

  14. Fermi/LAT search for counterpart to the IceCube event 67093193 (run 127853)

    NASA Astrophysics Data System (ADS)

    Vianello, G.; Magill, J. D.; Omodei, N.; Kocevski, D.; Ajello, M.; Buson, S.; Krauss, F.; Chiang, J.

    2016-04-01

    on behalf of the Fermi-LAT team: We have searched the Fermi Large Area Telescope data for a high-energy gamma-ray counterpart for the IceCube High Energy Starting Event (HESE) 67093193, detected in run 127853 on 2016-04-27 05:52:32.00 UT (AMON GCN notice rev. 2, http://gcn.gsfc.nasa.gov/notices_amon/67093193_127853.amon . See http://gcn.gsfc.nasa.gov/doc/Public_Doc_AMON_IceCube_GCN_Alerts_v2.pdf for a description of HESE events and related GCN notices).

  15. Interaction forces between red cells agglutinated by antibody. II. Measurement of hydrodynamic force of breakup.

    PubMed Central

    Tha, S P; Shuster, J; Goldsmith, H L

    1986-01-01

    The expressions derived in the previous paper for the respective normal, F3, and shear forces, Fshear, acting along and perpendicular to the axis of a doublet of rigid spheres, were used to determine the hydrodynamic forces required to separate two red cell spheres of antigenic type B crosslinked by the corresponding antibody. Cells were sphered and swollen in isotonic buffered glycerol containing 8 X 10(-5) M sodium dodecyl sulfate, fixed in 0.085% glutaraldehyde, and suspended in aqueous glycerol (viscosity: 15-34 mPa s), containing 0.15 M NaCl and anti-B antibody from human hyperimmune antiserum at concentrations from 0.73 to 3.56 vol%. After incubating and mixing for 12 h, doublets were observed through a microscope flowing in a 178-micron tube by gravity feed between two reservoirs. Using a traveling microtube apparatus, the doublets were tracked in a constantly accelerating flow and the translational and rotational motions were recorded on videotape until breakup occurred. From a frame by frame replay of the tape, the radial position, velocity and orientation of the doublet were obtained and the normal and shear forces of separation at breakup computed. Both forces increased significantly with increasing antiserum concentration, the mean values of F3 increasing from 0.060 to 0.197 nN, and Fshear from 0.023 to 0.072 nN. There was no significant effect of glycerol viscosity on the forces of separation. It was not possible to determine whether the shear or normal force was responsible for doublet separation. Measurements of the mean dimensionless period of rotation, TG, of doublets in suspensions containing 0.73 and 2.40% antiserum undergoing steady flow were also made to test whether the spheres were rigidly linked or capable of some independent rotation. A fairly narrow distribution in TG about the value 15.64, predicted for rigidly-linked doublets, was obtained at both antiserum concentrations. Images FIGURE 1 PMID:3801572

  16. The Search for High Energy Extended Emission by Fermi-LAT from Swift-Localized Gamma-Ray Bursts

    SciTech Connect

    Chiang, J.; Racusin, J.L.; /NASA, Goddard

    2012-05-01

    The brighter Fermi-LAT bursts have exhibited emission at energies >0.1 GeV that persists as late as {approx}2 ks after the prompt phase has nominally ended. This so-called 'extended emission' could arise from continued activity of the prompt burst mechanism or it could be the start of a high energy afterglow component. The high energy extended emission seen by the LAT has typically followed a t{sup -}{gamma} power-law temporal decay where {gamma} {approx} 1.2-1.7 and has shown no strong indication of spectral evolution. In contrast, the prompt burst emission generally displays strong spectral variability and more complex temporal changes in the LAT band. This differing behavior suggests that the extended emission likely corresponds to an early afterglow phase produced by an external shock. In this study, we look for evidence of high energy extended emission from 145 Swift-localized GRBs that have occurred since the launch of Fermi. A majority of these bursts were either outside of the LAT field-of-view or were otherwise not detected by the LAT during the prompt phase. However, because of the scanning operation of the Fermi satellite, the long-lived extended emission of these bursts may be detectable in the LAT data on the {approx}few ks time scale. We will look for emission from individual bursts and will perform a stacking analysis in order to set bounds on this emission for the sample as a whole. The detection of such emission would have implications for afterglow models and for the overall energy budget of GRBs.

  17. Suenos Indocumentados: Using LatCrit to Explore the Testimonios of Undocumented and U.S. Born Chicana College Students on Discourses of Racist Nativism in Education

    ERIC Educational Resources Information Center

    Huber, Lindsay Perez

    2010-01-01

    Latina/o critical race theory (LatCrit) is used as an overarching framework that examines the intersectionality of race, class, and gender while also acknowledging the unique forms of subordination within the Latina/o community based on immigration status, language, phenotype, and ethnicity. LatCrit allows for the specific examination of race and…

  18. VizieR Online Data Catalog: Fermi-LAT flaring gamma-ray sources from FAVA (Ackermann+, 2013)

    NASA Astrophysics Data System (ADS)

    Ackermann, M.; Ajello, M.; Albert, A.; Allafort, A.; Antolini, E.; Baldini, L.; Ballet, J.; Barbiellini, G.; Bastieri, D.; Bechtol, K.; Bellazzini, R.; Blandford, R. D.; Bloom, E. D.; Bonamente, E.; Bottacini, E.; Bouvier, A.; Brandt, T. J.; Bregeon, J.; Brigida, M.; Bruel, P.; Buehler, R.; Buson, S.; Caliandro, G. A.; Cameron, R. A.; Caraveo, P. A.; Cavazzuti, E.; Cecchi, C.; Charles, E.; Chekhtman, A.; Cheung, C. C.; Chiang, J.; Chiaro, G.; Ciprini, S.; Claus, R.; Cohen-Tanugi, J.; Conrad, J.; Cutini, S.; Dalton, M.; D'Ammando, F.; de Angelis, A.; de Palma, F.; Dermer, C. D.; di Venere, L.; Drell, P. S.; Drlica-Wagner, A.; Favuzzi, C.; Fegan, S. J.; Ferrara, E. C.; Focke, W. B.; Franckowiak, A.; Fukazawa, Y.; Funk, S.; Fusco, P.; Gargano, F.; Gasparrini, D.; Germani, S.; Giglietto, N.; Giordano, F.; Giroletti, M.; Glanzman, T.; Godfrey, G.; Grenier, I. A.; Grondin, M.-H.; Grove, J. E.; Guiriec, S.; Hadasch, D.; Hanabata, Y.; Harding, A. K.; Hayashida, M.; Hays, E.; Hewitt, J.; Hill, A. B.; Horan, D.; Hou, X.; Hughes, R. E.; Inoue, Y.; Jackson, M. S.; Jogler, T.; J! Ohannesso, N. G.; Johnson, W. N.; Kamae, T.; Kataoka, J.; Kawano, T.; Knodlseder, J.; Kuss, M.; Lande, J.; Larsson, S.; Latronico, L.; Lemoine-Goumard, M.; Longo, F.; Loparco, F.; Lott, B.; Lovellette, M. N.; Lubrano, P.; Mayer, M.; Mazziotta, M. N.; McEnery, J. E.; Michelson, P. F.; Mitthumsiri, W.; Mizuno, T.; Monte, C.; Monzani, M. E.; Morselli, A.; Moskalenko, I. V.; Murgia, S.; Nemmen, R.; Nuss, E.; Ohsugi, T.; Okumura, A.; Omodei, N.; Orienti, M.; Orlando, E.; Ormes, J. F.; Paneque, D.; Panetta, J. H.; Perkins, J. S.; Pesce-Rollins, M.; Piron, F.; Pivato, G.; Porter, T. A.; Raino, S.; Rando, R.; Razzano, M.; Reimer, A.; Reimer, O.; Romoli, C.; Roth, M.; Sanchez-Conde, M.; Scargle, J. D.; Schulz, A.; Sgro, C.; Siskind, E. J.; Spandre, G.; Spinelli, P.; Suson, D. J.; Takahashi, H.; Takeuchi, Y.; Thayer, J. G.; Thayer, J. B.; Thompson, D. J.; Tibaldo, L.; Tinivella, M.; Torres, D. F.; Tosti, G.; Troja, E.; Tronconi, V.; Usher, T. L.; Vandenbroucke, J.; Vasileiou, V.; Vianello, G.; Vitale, V.; Winer, B. L.; Wood, K. S.; Wood, M.; Yang, Z.

    2015-01-01

    We applied FAVA (Fermi All-sky Variability Analysis) to the first 47 months of Fermi/LAT observations (2008 August 4 to 2012 July 16 UTC), in weekly time intervals. The total number of weeks is 206. We considered two ranges of gamma-ray energy, E>100MeV and E>800MeV, to increase the sensitivity for spectrally soft and hard flares, respectively. We generate measured and expected count maps with a resolution of 0.25deg2 per pixel. We found LAT counterparts for 192 of the 215 FAVA sources. Most of the associated sources, 177, are AGNs. (2 data files).

  19. Constraints on the Galactic Halo Dark Matter from Fermi-LAT Diffuse Measurements

    NASA Technical Reports Server (NTRS)

    Ackermann, M.; Ajello, M.; Atwood, W. B.; Baldini, L.; Barbiellini, G.; Bastieri, D.; Bechtol, K.; Bellazzini, R.; Blandford, R. D.; Bloom, E. D.; Bonamente, E.; Borgland, A. W.; Bottacini, E.; Brandt, Theresa J.; Bregeon, J.; Brigida, M.; Bruel, P.; Buehler, R.; Buson, S.; Caliandro, G. A.; Cameron, R. A.; Caraveo, P A.; Casandjian, J. M.; Cecchi, C.; Chekhtman, A.; Chiang, J.; Ciprini, S.; Claus, R.; Cohen-Tanugi, J.; Conrad, J.; Cuoco, A.; Guiriec, Sylvain Germain; McEnery, Julie E.; Scargle. J. D.; Troja, Eleonora

    2012-01-01

    We have performed an analysis of the diffuse gamma-ray emission with the Fermi Large Area Telescope (LAT) in the Milky Way halo region, searching for a signal from dark matter annihilation or decay. In the absence of a robust dark matter signal, constraints are presented. We consider both gamma rays produced directly in the dark matter annihilation/decay and produced by inverse Compton scattering of the e+/e- produced in the annihilation/decay. Conservative limits are derived requiring that the dark matter signal does not exceed the observed diffuse gamma-ray emission. A second set of more stringent limits is derived based on modeling the foreground astrophysical diffuse emission using the GALPROP code. Uncertainties in the height of the diffusive cosmic-ray halo, the distribution of the cosmic-ray sources in the Galaxy, the index of the injection cosmic-ray electron spectrum, and the column density of the interstellar gas are taken into account using a profile likelihood formalism, while the parameters governing the cosmic-ray propagation have been derived from fits to local cosmic-ray data. The resulting limits impact the range of particle masses over which dark matter thermal production in the early universe is possible, and challenge the interpretation of the PAMELA/Fermi-LAT cosmic ray anomalies as the annihilation of dark matter.

  20. Search for gamma-ray emissions from AE Aquarii with Fermi LAT

    NASA Astrophysics Data System (ADS)

    Li, Jian; Rea, Nanda; De Ona Wilhelmi, Emma; Torres, Diego F.; Hou, Xian

    2016-07-01

    AE Aquarii is a cataclysmic variable with the fastest known rotating magnetized white dwarf (P_{spin} = 33.08 s). We report on deep searches for gamma-ray emission and pulsations from AE Aquarii in seven years of Fermi-LAT Pass 8 data. Using different X-ray observations spanning 20 years, we substantially extended the timing ephemeris of AE Aquarii. A spin phase jump was discovered between MJD 55122.5 - 56078.64 by X-ray timing analysis. Using the extended timing ephemeris, we searched for gamma-ray pulsations at the spin period and its first harmonic. No gamma-ray pulsation were detected above 3 sigma significance. Neither steady gamma-ray emission nor gamma-ray variability of AE Aquarii were detected by Fermi-LAT. We impose the most restrictive upper limit on the gamma-ray emission from AE Aquarii to date, as 1.23×10^{-12} erg cm^{-2} s^{-1} in 0.1-300 GeV range providing constrains on models.

  1. Search for gamma-ray emission from star-forming galaxies with Fermi LAT

    NASA Astrophysics Data System (ADS)

    Rojas-Bravo, César; Araya, Miguel

    2016-11-01

    Recent studies have found a positive correlation between the star formation rate (SFR) of galaxies and their gamma-ray luminosity. Galaxies with a high SFR are expected to produce a large amount of high-energy cosmic rays, which emit gamma-rays when interacting with the interstellar medium and radiation fields. We search for gamma-ray emission from a sample of galaxies within and beyond the Local Group with data from the LAT instrument onboard the Fermi satellite. We exclude recently detected galaxies (NGC 253, M82, NGC 4945, NGC 1068, NGC 2146, Arp 220) and use seven years of cumulative `Pass 8' data from the LAT in the 100 MeV to 100 GeV range. No new detections are seen in the data and upper limits for the gamma-ray fluxes are calculated. The correlation between gamma-ray luminosity and infrared luminosity for galaxies obtained using our new upper limits is in agreement with a previously published correlation, but the new upper limits imply that some galaxies are not as efficient gamma-ray emitters as previously thought.

  2. Fermi-LAT Observations of High-Energy Gamma-Ray Emission toward the Galactic Center

    NASA Astrophysics Data System (ADS)

    Ajello, M.; Albert, A.; Atwood, W. B.; Barbiellini, G.; Bastieri, D.; Bechtol, K.; Bellazzini, R.; Bissaldi, E.; Blandford, R. D.; Bloom, E. D.; Bonino, R.; Bottacini, E.; Brandt, T. J.; Bregeon, J.; Bruel, P.; Buehler, R.; Buson, S.; Caliandro, G. A.; Cameron, R. A.; Caputo, R.; Caragiulo, M.; Caraveo, P. A.; Cecchi, C.; Chekhtman, A.; Chiang, J.; Chiaro, G.; Ciprini, S.; Cohen-Tanugi, J.; Cominsky, L. R.; Conrad, J.; Cutini, S.; D’Ammando, F.; de Angelis, A.; de Palma, F.; Desiante, R.; Di Venere, L.; Drell, P. S.; Favuzzi, C.; Ferrara, E. C.; Fusco, P.; Gargano, F.; Gasparrini, D.; Giglietto, N.; Giommi, P.; Giordano, F.; Giroletti, M.; Glanzman, T.; Godfrey, G.; Gomez-Vargas, G. A.; Grenier, I. A.; Guiriec, S.; Gustafsson, M.; Harding, A. K.; Hewitt, J. W.; Hill, A. B.; Horan, D.; Jogler, T.; Jóhannesson, G.; Johnson, A. S.; Kamae, T.; Karwin, C.; Knödlseder, J.; Kuss, M.; Larsson, S.; Latronico, L.; Li, J.; Li, L.; Longo, F.; Loparco, F.; Lovellette, M. N.; Lubrano, P.; Magill, J.; Maldera, S.; Malyshev, D.; Manfreda, A.; Mayer, M.; Mazziotta, M. N.; Michelson, P. F.; Mitthumsiri, W.; Mizuno, T.; Moiseev, A. A.; Monzani, M. E.; Morselli, A.; Moskalenko, I. V.; Murgia, S.; Nuss, E.; Ohno, M.; Ohsugi, T.; Omodei, N.; Orlando, E.; Ormes, J. F.; Paneque, D.; Pesce-Rollins, M.; Piron, F.; Pivato, G.; Porter, T. A.; Rainò, S.; Rando, R.; Razzano, M.; Reimer, A.; Reimer, O.; Ritz, S.; Sánchez-Conde, M.; Saz Parkinson, P. M.; Sgrò, C.; Siskind, E. J.; Smith, D. A.; Spada, F.; Spandre, G.; Spinelli, P.; Suson, D. J.; Tajima, H.; Takahashi, H.; Thayer, J. B.; Torres, D. F.; Tosti, G.; Troja, E.; Uchiyama, Y.; Vianello, G.; Winer, B. L.; Wood, K. S.; Zaharijas, G.; Zimmer, S.

    2016-03-01

    The Fermi Large Area Telescope (LAT) has provided the most detailed view to date of the emission toward the Galactic center (GC) in high-energy γ-rays. This paper describes the analysis of data taken during the first 62 months of the mission in the energy range 1–100 GeV from a 15° × 15° region about the direction of the GC. Specialized interstellar emission models (IEMs) are constructed to enable the separation of the γ-ray emissions produced by cosmic ray particles interacting with the interstellar gas and radiation fields in the Milky Way into that from the inner ∼1 kpc surrounding the GC, and that from the rest of the Galaxy. A catalog of point sources for the 15° × 15° region is self-consistently constructed using these IEMs: the First Fermi-LAT Inner Galaxy Point Source Catalog (1FIG). The spatial locations, fluxes, and spectral properties of the 1FIG sources are presented, and compared with γ-ray point sources over the same region taken from existing catalogs. After subtracting the interstellar emission and point-source contributions a residual is found. If templates that peak toward the GC are used to model the positive residual the agreement with the data improves, but none of the additional templates tried account for all of its spatial structure. The spectrum of the positive residual modeled with these templates has a strong dependence on the choice of IEM.

  3. EINSTEIN@HOME DISCOVERY OF FOUR YOUNG GAMMA-RAY PULSARS IN FERMI LAT DATA

    SciTech Connect

    Pletsch, H. J.; Allen, B.; Aulbert, C.; Bock, O.; Eggenstein, H. B.; Fehrmann, H.; Machenschalk, B.; Papa, M. A.; Guillemot, L.; Champion, D. J.; Karuppusamy, R.; Kramer, M.; Ng, C.; Anderson, D.; Hammer, D.; Siemens, X.; Keith, M.; Ray, P. S. E-mail: lucas.guillemot@cnrs-orleans.fr

    2013-12-10

    We report the discovery of four gamma-ray pulsars, detected in computing-intensive blind searches of data from the Fermi Large Area Telescope (LAT). The pulsars were found using a novel search approach, combining volunteer distributed computing via Einstein@Home and methods originally developed in gravitational-wave astronomy. The pulsars PSRs J0554+3107, J1422–6138, J1522–5735, and J1932+1916 are young and energetic, with characteristic ages between 35 and 56 kyr and spin-down powers in the range 6 × 10{sup 34}—10{sup 36} erg s{sup –1}. They are located in the Galactic plane and have rotation rates of less than 10 Hz, among which the 2.1 Hz spin frequency of PSR J0554+3107 is the slowest of any known gamma-ray pulsar. For two of the new pulsars, we find supernova remnants coincident on the sky and discuss the plausibility of such associations. Deep radio follow-up observations found no pulsations, suggesting that all four pulsars are radio-quiet as viewed from Earth. These discoveries, the first gamma-ray pulsars found by volunteer computing, motivate continued blind pulsar searches of the many other unidentified LAT gamma-ray sources.

  4. Radio Detection of the Fermi-LAT Blind Search Millisecond Pulsar J1311-3430

    NASA Technical Reports Server (NTRS)

    Ray, P. S.; Ransom, S. M.; Cheung, C. C.; Giroletti, M.; Cognard, I.; Camilo, F.; Bhattacharyya, B.; Roy, J.; Romani, R. W.; Ferrara, E. C.; Guillemot, L.; Johnston, S.; Keith, M.; Kerr, M.; Kramer, M.; Pletsch, H. J.; Parkinson, P. M. Saz

    2013-01-01

    We report the detection of radio emission from PSR J1311.3430, the first millisecond pulsar (MSP) discovered in a blind search of Fermi Large Area Telescope (LAT) gamma-ray data. We detected radio pulsations at 2 GHz, visible for less than 10% of approximately 4.5 hr of observations using the Green Bank Telescope (GBT). Observations at 5 GHz with the GBT and at several lower frequencies with Parkes, Nan cay, and the Giant Metrewave Radio Telescope resulted in non-detections. We also report the faint detection of a steep spectrum continuum radio source (0.1 mJy at 5 GHz) in interferometric imaging observations with the Jansky Very Large Array. These detections demonstrate that PSR J1311.3430 is not radio quiet and provide additional evidence that radio-quiet MSPs are rare. The radio dispersion measure of 37.8 pc cm(exp -3) provides a distance estimate of 1.4 kpc for the system, yielding a gamma-ray efficiency of 30%, typical of LAT-detected MSPs. We see apparent excess delay in the radio pulses as the pulsar appears from eclipse and we speculate on possible mechanisms for the non-detections of the pulse at other orbital phases and observing frequencies.

  5. Search for gamma-ray emission from star-forming galaxies with Fermi LAT

    NASA Astrophysics Data System (ADS)

    Rojas-Bravo, César; Araya, Miguel

    2016-08-01

    Recent studies have found a positive correlation between the star-formation rate of galaxies and their gamma-ray luminosity. Galaxies with a high star-formation rate are expected to produce a large amount of high-energy cosmic rays, which emit gamma-rays when interacting with the interstellar medium and radiation fields. We search for gamma-ray emission from a sample of galaxies within and beyond the Local Group with data from the LAT instrument onboard the Fermi satellite. We exclude recently detected galaxies (NGC 253, M82, NGC 4945, NGC 1068, NGC 2146, Arp 220) and use seven years of cumulative "Pass 8" data from the LAT in the 100 MeV to 100 GeV range. No new detections are seen in the data and upper limits for the gamma-ray fluxes are calculated. The correlation between gamma-ray luminosity and infrared luminosity for galaxies obtained using our new upper limits is in agreement with a previously published correlation, but the new upper limits imply that some galaxies are not as efficient gamma-ray emitters as previously thought.

  6. Fermi LAT Observations of the Crab Nebula During the Exceptional April 2011 Outburst

    NASA Technical Reports Server (NTRS)

    Hays, Elizabeth

    2012-01-01

    The Crab Nebula, formerly thought to be steady in gamma rays, shows unexpected and occasionally dramatic variability in high-energy gamma rays. The Large Area Telescope (LAT) on Fermi recorded several strong outbursts, including dedicated pointed observations of the brightest yet seen, a spectacular flare in April 2011. These observations provide a particularly detailed look at the temporal and spectral characteristics of the nebula during the flare. The LAT data show an additional component in the spectral energy distribution that peaks at a maximum of $375\\pm26\\mathrm{MeV}$. In the probable scenario that this component is synchrotron emission, the electrons are accelerated to extreme energies that are difficult to reconcile with the very rapid change in flux and the expectation for acceleration processes and conditions occurring within the pulsar wind nebula. The physical location and mechanism driving the flares remains undetermined despite observations across the spectrum made by a variety of instruments including the Hubble Space Telescope, the Chandra X-ray Observatory, and the Very Large Array. I will present timing and spectral studies of the high-energy gamma-ray data, discuss implications for the origin of the flares, and highlight preparations for the next major flare.

  7. RADIO DETECTION OF THE FERMI-LAT BLIND SEARCH MILLISECOND PULSAR J1311-3430

    SciTech Connect

    Ray, P. S.; Wood, K. S.; Ransom, S. M.; Cheung, C. C.; Giroletti, M.; Cognard, I.; Camilo, F.; Bhattacharyya, B.; Roy, J.; Romani, R. W.; Kerr, M.; Ferrara, E. C.; Guillemot, L.; Kramer, M.; Johnston, S.; Keith, M.; Pletsch, H. J.; Saz Parkinson, P. M.

    2013-01-20

    We report the detection of radio emission from PSR J1311-3430, the first millisecond pulsar (MSP) discovered in a blind search of Fermi Large Area Telescope (LAT) gamma-ray data. We detected radio pulsations at 2 GHz, visible for <10% of {approx}4.5 hr of observations using the Green Bank Telescope (GBT). Observations at 5 GHz with the GBT and at several lower frequencies with Parkes, Nancay, and the Giant Metrewave Radio Telescope resulted in non-detections. We also report the faint detection of a steep spectrum continuum radio source (0.1 mJy at 5 GHz) in interferometric imaging observations with the Jansky Very Large Array. These detections demonstrate that PSR J1311-3430 is not radio quiet and provide additional evidence that radio-quiet MSPs are rare. The radio dispersion measure of 37.8 pc cm{sup -3} provides a distance estimate of 1.4 kpc for the system, yielding a gamma-ray efficiency of 30%, typical of LAT-detected MSPs. We see apparent excess delay in the radio pulses as the pulsar appears from eclipse and we speculate on possible mechanisms for the non-detections of the pulse at other orbital phases and observing frequencies.

  8. Search for Large Extra Dimensions Based on Observations of Neutron Stars with the Fermi-LAT

    SciTech Connect

    Berenji, Bijan

    2012-09-19

    Large extra dimensions (LED) have been proposed to account for the apparent weakness of gravitation. These theories also indicate that the postulated massive Kaluza-Klein (KK) gravitons may be produced by nucleon-nucleon bremsstrahlung in the course of core collapse of supernovae. Hannestad and Raffelt have predicted energy spectra of gamma ray emission from the decay of KK gravitons trapped by the gravity of the remnant neutron stars (NS). These and other authors have used EGRET data on NS to obtain stringent limits on LED. Fermi-LAT is observing radio pulsar positions obtained from radio and x-ray catalogs. NS with certain characteristics are unlikely emitter of gamma rays, and emit in radio and perhaps x-rays. This talk will focus on the blind analysis we plan to perform, which has been developed using the 1st 2 months of all sky data and Monte Carlo simulations, to obtain limits on LED based on about 1 year of Fermi-LAT data. Preliminary limits from this analysis using these first 2 months of data will be also be discussed.

  9. GRB2-Mediated Recruitment of THEMIS to LAT Is Essential for Thymocyte Development

    PubMed Central

    Paster, Wolfgang; Brockmeyer, Claudia; Fu, Guo; Simister, Philip C.; de Wet, Ben; Martinez-Riaño, Ana; Hoerter, John A. H.; Feller, Stephan M.; Wülfing, Christoph; Gascoigne, Nicholas R. J.

    2013-01-01

    Thymocyte-expressed molecule involved in selection (THEMIS) is a recently identified regulator of thymocyte positive selection. THEMIS’s mechanism of action is unknown, and whether it has a role in TCR-proximal signaling is controversial. In this article, we show that THEMIS and the adapter molecule growth factor receptor–bound protein 2 (GRB2) associate constitutively through binding of a conserved PxRPxK motif within the proline-rich region 1 of THEMIS to the C-terminal SH3-domain of GRB2. This association is indispensable for THEMIS recruitment to the immunological synapse via the transmembrane adapter linker for activation of T cells (LAT) and for THEMIS phosphorylation by Lck and ZAP-70. Two major sites of tyrosine phosphorylation were mapped to a YY-motif close to proline-rich region 1. The YY-motif was crucial for GRB2 binding, suggesting that this region of THEMIS might control local phosphorylation-dependent conformational changes important for THEMIS function. Finally, THEMIS binding to GRB2 was required for thymocyte development. Our data firmly assign THEMIS to the TCR-proximal signaling cascade as a participant in the LAT signalosome and suggest that the THEMIS–GRB2 complex might be involved in shaping the nature of Ras signaling, thereby governing thymic selection. PMID:23460737

  10. Fermi LAT Observations of Gamma-Ray Transients Near the Galactic Plane

    NASA Technical Reports Server (NTRS)

    Hays, Elizabeth Anne

    2010-01-01

    The Large Area Telescope (LAT) on the Fermi Gamma-ray Space Telescope provides unprecedented sensitivity for all-sky monitoring of gamma-ray activity from 20 MeV to >300 GeV. The observatory scans the entire sky every three hours and allows a general search for flaring activity on daily timescales. This search is conducted automatically as part of the ground processing and allows a fast response to transient events, typically less than a day. Most flares are spatially associated with known blazars, but in several cases during the first year of observations, gamma-ray flares occurring near the Galactic plane did not reveal any initially compelling counterparts. This prompted follow-up observations in X-ray, optical, and radio to attempt to identify the origin of the emission and probe the possible existence of a class of transient gamma-ray sources in the Galaxy. We will report on the details of these LAT events and the results of the multi-wavelength counterpart searches.

  11. The First Fermi-LAT Catalog of Sources Above 10 GeV

    NASA Technical Reports Server (NTRS)

    Ackermann, M.; Ajello, M.; Allafort, A.; Atwood, W. B.; Baldini, L.; Ballet, J.; Barbiellini, G.; Bastieri, D.; Bechtol, K.; Moiseev, Alexander A.

    2013-01-01

    We present a catalog of gamma-ray sources at energies above 10 GeV based on data from the Large Area Telescope (LAT) accumulated during the first 3 yr of the Fermi Gamma-ray Space Telescope mission. The first Fermi-LAT catalog of >10 GeV sources (1FHL) has 514 sources. For each source we present location, spectrum, a measure of variability, and associations with cataloged sources at other wavelengths. We found that 449 (87%) could be associated with known sources, of which 393 (76% of the 1FHL sources) are active galactic nuclei. Of the 27 sources associated with known pulsars, we find 20 (12) to have significant pulsations in the range >10 GeV (>25 GeV). In this work we also report that, at energies above 10 GeV, unresolved sources account for 27% +/- 8% of the isotropic ? -ray background, while the unresolved Galactic population contributes only at the few percent level to the Galactic diffuse background. We also highlight the subset of the 1FHL sources that are best candidates for detection at energies above 50-100 GeV with current and future ground-based ? -ray observatories.

  12. IFT20 controls LAT recruitment to the immune synapse and T-cell activation in vivo.

    PubMed

    Vivar, Omar I; Masi, Giulia; Carpier, Jean-Marie; Magalhaes, Joao G; Galgano, Donatella; Pazour, Gregory J; Amigorena, Sebastian; Hivroz, Claire; Baldari, Cosima T

    2016-01-12

    Biogenesis of the immune synapse at the interface between antigen-presenting cells and T cells assembles and organizes a large number of membrane proteins required for effective signaling through the T-cell receptor. We showed previously that the intraflagellar transport protein 20 (IFT20), a component of the intraflagellar transport system, controls polarized traffic during immune synapse assembly. To investigate the role of IFT20 in primary CD4(+) T cells in vitro and in vivo, we generated mice bearing a conditional defect of IFT20 expression in T cells. We show that in the absence of IFT20, although cell spreading and the polarization of the centrosome were unaffected, T-cell receptor (TCR)-mediated signaling and recruitment of the signaling adaptor LAT (linker for activation of T cells) at the immune synapse were reduced. As a consequence, CD4(+) T-cell activation and proliferation were also defective. In vivo, conditional IFT20-deficient mice failed to mount effective antigen-specific T-cell responses, and their T cells failed to induce colitis after adoptive transfer to Rag(-/-) mice. IFT20 is therefore required for the delivery of the intracellular pool of LAT to the immune synapse in naive primary T lymphocytes and for effective T-cell responses in vivo. PMID:26715756

  13. IFT20 controls LAT recruitment to the immune synapse and T-cell activation in vivo

    PubMed Central

    Vivar, Omar I.; Masi, Giulia; Carpier, Jean-Marie; Magalhaes, Joao G.; Galgano, Donatella; Pazour, Gregory J.; Amigorena, Sebastian; Hivroz, Claire; Baldari, Cosima T.

    2016-01-01

    Biogenesis of the immune synapse at the interface between antigen-presenting cells and T cells assembles and organizes a large number of membrane proteins required for effective signaling through the T-cell receptor. We showed previously that the intraflagellar transport protein 20 (IFT20), a component of the intraflagellar transport system, controls polarized traffic during immune synapse assembly. To investigate the role of IFT20 in primary CD4+ T cells in vitro and in vivo, we generated mice bearing a conditional defect of IFT20 expression in T cells. We show that in the absence of IFT20, although cell spreading and the polarization of the centrosome were unaffected, T-cell receptor (TCR)-mediated signaling and recruitment of the signaling adaptor LAT (linker for activation of T cells) at the immune synapse were reduced. As a consequence, CD4+ T-cell activation and proliferation were also defective. In vivo, conditional IFT20-deficient mice failed to mount effective antigen-specific T-cell responses, and their T cells failed to induce colitis after adoptive transfer to Rag−/− mice. IFT20 is therefore required for the delivery of the intracellular pool of LAT to the immune synapse in naive primary T lymphocytes and for effective T-cell responses in vivo. PMID:26715756

  14. Study of LAT1 Expression in Brain Metastases: Towards a Better Understanding of the Results of Positron Emission Tomography Using Amino Acid Tracers

    PubMed Central

    Papin-Michault, Caroline; Bonnetaud, Christelle; Dufour, Maxime; Almairac, Fabien; Coutts, Mickael; Patouraux, Stéphanie; Virolle, Thierry; Darcourt, Jacques; Burel-Vandenbos, Fanny

    2016-01-01

    Positron emission tomography using radiolabeled amino acid (PET-AA) appears to be promising in distinguishing between recurrent tumour and radionecrosis in the follow-up of brain metastasis (BM). The amino acid transporter LAT1 and its cofactor CD98, which are involved in AA uptake, have never been investigated in BM. The aim of our study was to determine and compare the expression of LAT1 and CD98 in BM and in non-tumoral brain tissue (NT). The expression of LAT1 and CD98 were studied by immunohistochemistry in 67 BM, including 18 BM recurrences after radiotherapy, in 53 NT, and in 13 cases of patients with previously irradiated brain tumor and investigated by [18F] FDOPA-PET. LAT1 and CD98 expression were detected in 98.5% and 59.7% of BM respectively and were significantly associated with BM tissue as compared to NT (p<0.001). LAT1 expression in recurrent BM was significantly increased as compared to newly occurring BM. Ten cases investigated by [18F] FDOPA-PET corresponding to recurrent BM displayed significant [18F] FDOPA uptake and LAT1 overexpression whereas three cases corresponding to radionecrosis showed no or low uptake and LAT1 expression. LAT1 expression level and [18F] FDOPA uptake were significantly correlated. In conclusion, we hypothesized that BM may overexpress the AA transporter LAT1. We have shown that LAT1 overexpression was common in BM and was specific for BM as compared to healthy brain. These results could explain the specific BM uptake on PET-AA. PMID:27276226

  15. Comparative studies on serological tests for syphilis

    PubMed Central

    Nakamura, Keizo; Ishizaka, Kimishige

    1954-01-01

    A comparative study was undertaken by the authors to determine the most reliable of the serodiagnostic tests for syphilis in current use in Japan. The criteria for the selection of sera, the way in which the standard tests were chosen, and the statistical method used for evaluating the results are described, and some of the detailed results are given. Five tests—the VDRL test, the agglutination test, Ogata's test, the Kahn test (with cardiolipin antigen), and Browning's test modified by Taniguchi (with cardiolipin antigen)—were found to be comparable in reliability to the Kolmer (Lederle) and VDRL (Lederle) tests employed in the USA. PMID:14364183

  16. Evaluation of C. diff.-CUBE test for detection of Clostridium difficile-associated diarrhea.

    PubMed

    Kurzynski, T A; Kimball, J L; Schultz, D A; Schell, R F

    1992-08-01

    The toxin B assay was used to evaluate C. diff.-CUBE, a new dot-immunobinding assay (DIA) for the laboratory diagnosis of Clostridium difficile-associated diarrhea. The widely used latex agglutination test was also included for comparison. Stools from 100 patients suspected of having C. difficile-associated diarrhea were tested. The toxin B assay, latex agglutination, and DIA tests were positive for 12%, 9%, and 22% of the specimens, respectively. The sensitivity, specificity, and positive and negative predictive values of the DIA test were 67%, 84%, 36%, and 95%, respectively, compared with the toxin B assay. The specificity (98%) and positive predictive value (78%) for the latex agglutination test were significantly higher than those of the DIA test. Of 13 specimens solely positive by the DIA test, 11 were cultured and none were positive. Clinical assessment supported only two of the 13 positive DIA results. When clinical assessment was included in the analysis, the DIA positive predictive value rose to 45%. Although the sensitivity and negative predictive values of the DIA test are comparable to the latex agglutination test, the low specificity and positive predictive values of the DIA test make it an inappropriate method to use for screening in a population with a low prevalence of true positives.

  17. Confronting recent AMS-02 positron fraction and Fermi-LAT extragalactic γ-ray background measurements with gravitino dark matter

    NASA Astrophysics Data System (ADS)

    Carquín, Edson; Díaz, Marco A.; Gómez-Vargas, Germán A.; Panes, Boris; Viaux, Nicolás

    2016-03-01

    Recent positron flux fraction measurements in cosmic-rays (CR) made by the AMS-02 detector confirm and extend the evidence on the existence of a new (yet unknown) source of high energy electrons and positrons. We test the gravitino dark matter of bilinear R-parity violating supersymmetric models as this electrons/positrons source. Being a long lived weak-interacting and spin 3/2 particle, it offers several particularities which makes it an attractive dark matter candidate. We compute the electron, positron and γ-ray fluxes produced by each gravitino decay channel as it would be detected at the Earth's position. Combining the flux from the different decay modes we are able to reproduce AMS-02 measurements of the positron fraction, as well as the electron and positron fluxes, with a gravitino dark matter mass in the range 1-3 TeV and lifetime of ˜1.0-0.7×1026 s. The high statistics measurement of electron and positron fluxes, and the flattening in the behaviour of the positron fraction recently found by AMS-02 allow us to determine that the preferred gravitino decaying mode by the fit is W±τ∓, unlike previous analyses. Then we study the viability of these scenarios through their implication in γ-ray observations. For this we use the Extragalactic γ-ray Background recently reported by the Fermi-LAT Collaboration and a state-of-the-art model of its known contributors. Based on the γ-ray analysis we exclude the gravitino parameter space which provides an acceptable explanation of the AMS-02 data. Therefore, we conclude that the gravitino of bilinear R-parity violating models is ruled out as the unique primary source of electrons and positrons needed to explain the rise in the positron fraction.

  18. Buffered Plate Antigen Test as a Screening Test for Diagnosis of Human Brucellosis

    PubMed Central

    Lucero, Nidia E.; Bolpe, Jorge E.

    1998-01-01

    Brucellosis in Argentina is currently investigated in bank donor blood by the standard plate agglutination test (PAT). This study evaluated the buffered plate antigen test (BPA), now used to screen for bovine brucellosis, as a screen for human disease. Of 57 sera from patients with culture-confirmed brucellosis, 100% were detected with the BPA. Of 142 sera positive by rose bengal (RB) and complement fixation (CF), from patients with clinical evidence of brucellosis, the BPA detected 100%. Of 307 sera from a nonsymptomatic population that were RB and CF negative, the BPA detected 99.67% of the negative sera. The data indicate that the BPA is satisfactory compared to the other agglutination tests employed. It is an inexpensive and practical screening test and reduces the nonspecific reactions detected by the PAT. PMID:9574720

  19. GRB2 Nucleates T Cell Receptor-Mediated LAT Clusters That Control PLC-γ1 Activation and Cytokine Production.

    PubMed

    Bilal, Mahmood Yousif; Houtman, Jon C D

    2015-01-01

    GRB2 is a ubiquitously expressed adaptor protein required for signaling downstream of multiple receptors. To address the role of GRB2 in receptor-mediated signaling, the expression of GRB2 was suppressed in human CD4+ T cells and its role downstream of the T cell receptor (TCR) was examined. Interestingly, GRB2 deficient T cells had enhanced signaling from complexes containing the TCR. However, GRB2 deficient T cells had substantially reduced production of IL-2 and IFN-γ. This defect was attributed to diminished formation of linker for activation of T cells (LAT) signaling clusters, which resulted in reduced MAP kinase activation, calcium flux, and PLC-γ1 recruitment to LAT signaling clusters. Add back of wild-type GRB2, but not a novel N-terminal SH3 domain mutant, rescued LAT microcluster formation, calcium mobilization, and cytokine release, providing the first direct evidence that GRB2, and its ability to bind to SH3 domain ligands, is required for establishing LAT microclusters. Our data demonstrate that the ability of GRB2 to facilitate protein clusters is equally important in regulating TCR-mediated functions as its capacity to recruit effector proteins. This highlights that GRB2 regulates signaling downstream of adaptors and receptors by both recruiting effector proteins and regulating the formation of signaling complexes.

  20. Fermi LAT Detection of a New Gamma-ray Source Associated with B2 0748+33

    NASA Astrophysics Data System (ADS)

    Cheung, C. C.

    2016-10-01

    The Large Area Telescope (LAT), one of two instruments on the Fermi Gamma-ray Space Telescope, has observed strong gamma-ray emission from a source positionally consistent with the flat-spectrum radio quasar B2 0748+33 with coordinates R.A. = 117.9736383 deg, Decl.

  1. 50 CFR Table 2c to Part 660... - Sablefish North of 36° N. lat. Allocations, 2014 and Beyond

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 50 Wildlife and Fisheries 13 2014-10-01 2014-10-01 false Sablefish North of 36° N. lat. Allocations, 2014 and Beyond 2c Table 2c to Part 660, Subpart C Wildlife and Fisheries FISHERY CONSERVATION AND MANAGEMENT, NATIONAL OCEANIC AND ATMOSPHERIC ADMINISTRATION, DEPARTMENT OF COMMERCE...

  2. 50 CFR Table 1c to Part 660... - Sablefish North of 36° N. lat. Allocations, 2013

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 50 Wildlife and Fisheries 13 2014-10-01 2014-10-01 false Sablefish North of 36° N. lat. Allocations, 2013 1c Table 1c to Part 660, Subpart C Wildlife and Fisheries FISHERY CONSERVATION AND MANAGEMENT, NATIONAL OCEANIC AND ATMOSPHERIC ADMINISTRATION, DEPARTMENT OF COMMERCE (CONTINUED) FISHERIES...

  3. ATel 7545: Fermi LAT Detection of a GeV flare from spectrally hard FSRQ S4 1800+44

    NASA Astrophysics Data System (ADS)

    Buson, S.; Fermi LAT Collaboration

    2015-05-01

    The Large Area Telescope (LAT), one of the two instruments on the Fermi Gamma-ray Space Telescope, has observed increasing gamma-ray flux and an unusually hard gamma-ray spectrum from a source positionally consistent with the flat spectrum radio quasar (FSRQ) S4 1800+44 (also known as 3FGL J1801.5+4403, Acero et al. ...

  4. Fermi-LAT detection of hard spectrum gamma-ray activity from the FSRQ PKS 1532+01

    NASA Astrophysics Data System (ADS)

    Ciprini, S.; Cheung, C. C.

    2015-03-01

    The Large Area Telescope (LAT), one of the two instruments on the Fermi Gamma-ray Space Telescope, has observed increasing gamma-ray flux and an unusually hard gamma-ray spectrum from a source positionally consistent with the flat spectrum radio quasar (FSRQ) PKS 1532+01 (also known as 3FGL J1534.5+0128, Acero et al.

  5. ATel 7453: Fermi LAT detection of a GeV flare from the FSRQ PKS 2032+107

    NASA Astrophysics Data System (ADS)

    Orienti, M.; D'Ammando, F.; Fermi Large Area Telescope Collaboration

    2015-04-01

    The Large Area Telescope (LAT), on board the Fermi Gamma-ray Space Telescope, has observed gamma-ray flaring activity from a source positionally consistent with the flat spectrum radio quasar PKS 2032+107 (also known as 3FGL J2035.3+1055, Acero et al. ...

  6. Fermi-LAT TOO observations of PSR J1119-6127 following its 2016 magnetar-like outburst

    NASA Astrophysics Data System (ADS)

    Younes, G.; Archibald, R.; Kouveliotou, C.; Kaspi, V.; Ray, P. S.; McEnery, J.; Fermi LAT Collaboration

    2016-08-01

    We requested and obtained Fermi-LAT target of opportunity (TOO) observations of the high-B gamma-ray pulsar PSR J1119-6127 between 2016 August 1 - 8. This pulsar recently showed magnetar-like bursts on 2016 July 27 and 28 (GCNs #19735, #19736, and ATel #9274).

  7. Erratum to ATel 6655: Fermi LAT Detection of a new Gamma-ray source Fermi J0507-5641

    NASA Astrophysics Data System (ADS)

    Carpenter, B.; Ojha, R.

    2014-11-01

    (The flux units have been corrected to x10^-6 photons cm^-2 s^-1.) The Large Area Telescope (LAT), one of the two instruments on the Fermi Gamma-ray Space Telescope, has observed strong gamma-ray emission from a new source.

  8. Genetic and Mechanistic Evaluation for the Mixed-Field Agglutination in B3 Blood Type with IVS3+5G>A ABO Gene Mutation

    PubMed Central

    Wang, Wei-Ting; Sun, Chien-Feng

    2012-01-01

    Background The ABO blood type B3 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 B3 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 B3 individuals and found that IVS3+5G>A attributes to all cases of B3. RT-PCR analyses revealed the presence of at least 7 types of aberrant B3 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 B3 glycosyltransferase lacking 19 amino acids at the N-terminal segment constituted only 0.9% of the splicing transcripts. Expression of the B3 cDNA with exon 3 deletion in the K562 erythroleukemia cells revealed that the B3 glycosyltransferase had only 40% of B1 activity in converting H antigen to B antigen. Notably, the typical mixed-field agglutination of B3-RBCs can be mimicked by adding anti-B antibody to the K562-B3 cells. Conclusions/Significance This study thereby demonstrates that both aberrant splicing of B transcripts and the reduced B3 glycosyltransferase activity contribute to weak B expression and the mixed-field agglutination of B3, adding to the complexity for the regulatory mechanisms of ABO gene expression. PMID:22624005

  9. EIGHT {gamma}-RAY PULSARS DISCOVERED IN BLIND FREQUENCY SEARCHES OF FERMI LAT DATA

    SciTech Connect

    Saz Parkinson, P. M.; Dormody, M.; Ziegler, M.; Belfiore, A.; Johnson, R. P.; Ray, P. S.; Abdo, A. A.; Grove, J. E.; Gwon, C.; Ballet, J.; Burnett, T. H.; Caliandro, G. A.; Camilo, F.; Caraveo, P. A.; De Luca, A.; Ferrara, E. C.; Harding, A. K.; Johnson, T. J.; Freire, P. C. C. E-mail: mdormody@ucsc.ed E-mail: Paul.Ray@nrl.navy.mi

    2010-12-10

    We report the discovery of eight {gamma}-ray pulsars in blind frequency searches of {approx}650 source positions using the Large Area Telescope (LAT), on board the Fermi Gamma-ray Space Telescope. We present the timing models, light curves, and detailed spectral parameters of the new pulsars. PSRs J1023-5746, J1044-5737, J1413-5205, J1429-5911, and J1954+2836 are young ({tau}{sub c} < 100 kyr), energetic (E-dot {approx}>10{sup 36} erg s{sup -1}), and located within the Galactic plane (|b| < 3{sup 0}). The remaining three pulsars, PSRs J1846+0919, J1957+5033, and J2055+25, are less energetic, and located off the plane. Five pulsars are associated with sources included in the Fermi-LAT bright {gamma}-ray source list, but only one, PSR J1413-6205, is clearly associated with an EGRET source. PSR J1023-5746 has the smallest characteristic age ({tau}{sub c} = 4.6 kyr) and is the most energetic (E-dot = 1.1x10{sup 37} erg s{sup -1}) of all {gamma}-ray pulsars discovered so far in blind searches. By analyzing >100 ks of publicly available archival Chandra X-ray data, we have identified the likely counterpart of PSR J1023-5746 as a faint, highly absorbed source, CXOU J102302.8-574606. The large X-ray absorption indicates that this could be among the most distant {gamma}-ray pulsars detected so far. PSR J1023-5746 is positionally coincident with the TeV source HESS J1023-575, located near the young stellar cluster Westerlund 2, while PSR J1954+2836 is coincident with a 4.3{sigma} excess reported by Milagro at a median energy of 35 TeV. PSRs J1957+5033 and J2055+25 have the largest characteristic ages ({tau}{sub c} {approx} 1 Myr) and are the least energetic (E-dot {approx}5x10{sup 33} erg s{sup -1}) of the newly discovered pulsars. We used recent XMM observations to identify the counterpart of PSR J2055+25 as XMMU J205549.4+253959. Deep radio follow-up observations of the eight pulsars resulted in no detections of pulsations and upper limits comparable to the faintest known

  10. Cap and trade schemes on waste management: a case study of the landfill allowance trading scheme (LATS) in England.

    PubMed

    Calaf-Forn, Maria; Roca, Jordi; Puig-Ventosa, Ignasi

    2014-05-01

    The Landfill Allowance Trading Scheme (LATS) is one of the main instruments used in England to enforce the landfill diversion targets established in the Directive 1999/31/EC of the European Parliament and of the Council of 26 April 1999 on the landfill of waste (Landfill Directive). Through the LATS, biodegradable municipal waste (BMW) allowances for landfilling are allocated to each local authority, otherwise known as waste disposal authorities (WDAs). The quantity of landfill allowances received is expected to decrease continuously from 2005/06 to 2019/20 so as to meet the objectives of the Landfill Directive. To achieve their commitments, WDAs can exchange, buy, sell or transfer allowances among each other, or may re-profile their own allocation through banking and/or borrowing. Despite the goals for the first seven years - which included two target years (2005/06 and 2009/10) - being widely achieved (the average allocation of allowances per WDA was 22.9% higher than those finally used), market activity among WDAs was high and prices were not very stable. Results in terms of waste reduction and recycling levels have been satisfactory. The reduction of BMW landfilled (in percentage) was higher during the first seven years of the LATS period (2005/06-2011/12) (around 7% annually) than during the previous period (2001/02-2004/05) (4.2% annually). Since 2008, the significance of the LATS diminished because of an increase in the rate of the UK Landfill Tax. The LATS was suppressed after the 2012/13 target year, before what it was initially scheduled. The purpose of this paper is to describe the particularities of the LATS, analyse its performance as a waste management policy, make a comparison with the Landfill Tax, discuss its main features as regards efficiency, effectiveness and the application of the "polluter pays" principle and finally discuss if the effect of the increase in the Landfill Tax is what made the LATS ultimately unnecessary. PMID:24661742

  11. MicroRNA-103 promotes tumor growth and metastasis in colorectal cancer by directly targeting LATS2

    PubMed Central

    Zheng, Yong-Bin; Xiao, Kuang; Xiao, Gao-Chun; Tong, Shi-Lun; Ding, Yu; Wang, Qiu-Shuang; Li, Sheng-Bo; Hao, Zhi-Nan

    2016-01-01

    Colorectal cancer (CRC) has become the third most common cancer worldwide and leads to a high mortality rate. Although colorectal cancer has been studied widely, the underlying molecular mechanism remains unclear. Increasing evidence shows that the abnormal expression of microRNAs (miRNAs) is involved in tumorigenesis. Previous studies have reported that miRNA-103 (miR-103) is dysregulated in CRC; however, the expression, function and mechanism of miR-103 in CRC are not well known. The present study showed that miR-103 was overexpressed in the primary tumor tissues of patients with CRC and was significantly associated with a more aggressive phenotype of CRC in patients. Survival rate analysis demonstrated that CRC patients with high miR-103 expression had a poorer overall survival compared with CRC patients with low miR-103 expression. In CRC cell lines, miR-103 inhibition significantly decreased the proliferation, invasion and migration of the cells in vitro. Furthermore, miR-103 repressed large tumor suppressor kinase 2 (LATS2) expression by directly binding to the LATS2-3′-untranslated region, and an inverse correlation was identified between the expression of miR-103 and LATS2 messenger RNA in primary CRC tissues. In addition, the restoration of LATS2 led to suppressed proliferation, invasion and migration of CRC cells. In vivo, miR-103 promotes tumor growth in nude mice. In summary, miR-103 performs a critical role in the promotion of the invasive and metastatic capacities of CRC, possibly by directly targeting LATS2. This miRNA may be involved in the development and progression of CRC. PMID:27602163

  12. A comparative electromyographical investigation of muscle utilization patterns using various hand positions during the lat pull-down.

    PubMed

    Signorile, Joseph F; Zink, Attila J; Szwed, Steven P

    2002-11-01

    This study aimed at investigating the effects of different hand positions on the electromyographic (EMG) activity of shoulder muscles during the performance of the lat pull-down exercise. Ten healthy men performed 3 repetitions of the lat pull-down exercise using their experimentally determined 10RM (repetition maximum) weight. Four different common variations of the lat pull-down were used: close grip (CG), supinated grip (SG), wide grip anterior (WGA), and wide grip posterior (WGP). Normalized root mean square of the EMG (NrmsEMG) activity for the right posterior deltoid (PD), latissimus dorsi (LD), pectoralis major (PM), teres major (TM), and long head of the triceps (TLH) were recorded using surface electrodes and normalized using maximum voluntary contractions. Repeated measures analysis of variance for each muscle detected statistical differences (p < 0.05) in myoelectric activity among hand positions during both the concentric and eccentric phases of the exercise. During the concentric phase, NrmsEMG results for the LD included WGA > WGP, SG, CG. For the TLH: WGA > WGP, SG, CG and WGP > CG, SG. For the PD: CG, WGA, SG > WGP. For the PM: CG, WGA, SG > WGP. During the eccentric phase, the LD produced the following patterns: WGA > WGP, SG, CG and WGP > CG. The TLH pattern showed WGA > SG and CG. For the PD: CG > WGA, WGP. The results indicate that changes in handgrip position affect the activities of specific muscles during the lat pull-down movement. Also, performance of the lat pull-down exercise using the WGA hand position produces greater muscle activity in the LD than any other hand position during both the concentric or eccentric phases of the movement.

  13. MicroRNA-103 promotes tumor growth and metastasis in colorectal cancer by directly targeting LATS2

    PubMed Central

    Zheng, Yong-Bin; Xiao, Kuang; Xiao, Gao-Chun; Tong, Shi-Lun; Ding, Yu; Wang, Qiu-Shuang; Li, Sheng-Bo; Hao, Zhi-Nan

    2016-01-01

    Colorectal cancer (CRC) has become the third most common cancer worldwide and leads to a high mortality rate. Although colorectal cancer has been studied widely, the underlying molecular mechanism remains unclear. Increasing evidence shows that the abnormal expression of microRNAs (miRNAs) is involved in tumorigenesis. Previous studies have reported that miRNA-103 (miR-103) is dysregulated in CRC; however, the expression, function and mechanism of miR-103 in CRC are not well known. The present study showed that miR-103 was overexpressed in the primary tumor tissues of patients with CRC and was significantly associated with a more aggressive phenotype of CRC in patients. Survival rate analysis demonstrated that CRC patients with high miR-103 expression had a poorer overall survival compared with CRC patients with low miR-103 expression. In CRC cell lines, miR-103 inhibition significantly decreased the proliferation, invasion and migration of the cells in vitro. Furthermore, miR-103 repressed large tumor suppressor kinase 2 (LATS2) expression by directly binding to the LATS2-3′-untranslated region, and an inverse correlation was identified between the expression of miR-103 and LATS2 messenger RNA in primary CRC tissues. In addition, the restoration of LATS2 led to suppressed proliferation, invasion and migration of CRC cells. In vivo, miR-103 promotes tumor growth in nude mice. In summary, miR-103 performs a critical role in the promotion of the invasive and metastatic capacities of CRC, possibly by directly targeting LATS2. This miRNA may be involved in the development and progression of CRC.

  14. miR-21 modulates resistance of HR-HPV positive cervical cancer cells to radiation through targeting LATS1

    SciTech Connect

    Liu, Shikai; Song, Lili Zhang, Liang; Zeng, Saitian; Gao, Fangyuan

    2015-04-17

    Although multiple miRNAs are found involved in radioresistance development in HR-HPV positive (+) cervical cancer, only limited studies explored the regulative mechanism of the miRNAs. miR-21 is one of the miRNAs significantly upregulated in HR-HPV (+) cervical cancer is also significantly associated with radioresistance. However, the detailed regulative network of miR-21 in radioresistance is still not clear. In this study, we confirmed that miR-21 overexpression was associated with higher level of radioresistance in HR-HPV (+) cervical cancer patients and thus decided to further explore its role. Findings of this study found miR-21 can negatively affect radiosensitivity of HR-HPV (+) cervical cancer cells and decrease radiation induced G2/M block and increase S phase accumulation. By using dual luciferase assay, we verified a binding site between miR-21 and 3′-UTR of large tumor suppressor kinase 1 (LATS1). Through direct binding, miR-21 can regulate LATS1 expression in cervical cancer cells. LATS1 overexpression can reverse miR-21 induced higher colony formation rate and also reduced miR-21 induced S phase accumulation and G2/M phase block reduction under radiation treatment. These results suggested that miR-21-LATS1 axis plays an important role in regulating radiosensitivity. - Highlights: • miR-21 is highly expressed in HR-HPV (+) radioresistant cervical cancer patients. • miR-21 can negatively affect radiosensitivity of HR-HPV (+) cervical cancer cells. • miR-21 can decrease radiation induced G2/M block and increase S phase accumulation. • miR-21 modulates radiosensitivity cervical cancer cell by directly targeting LATS1.

  15. Analysis of a herpes simplex virus type 1 LAT mutant with a deletion between the putative promoter and the 5' end of the 2.0-kilobase transcript.

    PubMed Central

    Maggioncalda, J; Mehta, A; Fraser, N W; Block, T M

    1994-01-01

    A herpes simplex virus type 1 strain 17 mutant with a deletion between genomic nucleotides 118880 and 119250 was constructed and called 17 delta Sty. The deletion removes most of a putative secondary LAT promoter (called LAPII) as well as 370 of the first 449 nucleotides of the proposed 8.5-kb transcript believed to be the precursor of 2.0-kb LAT. 17 delta Sty was shown to produce major 2.0-kb LATs in tissue culture. Moreover, trigeminal nerves from latently infected mice contained an intact 1.45- to 2.0-kb LAT as well as the minor LATs which are recognized by probes specific for regions downstream of the 2.0-kb LAT. Finally, 17 delta Sty reactivated with normal kinetics from the trigeminal ganglia of latently infected mice in the explant cocultivation assay and egressed from tissue culture cells as efficiently as wild-type virus. These results clearly show that the region deleted in 17 delta Sty is dispensable for intact 2-kb LAT production, viral egress in tissue culture, and normal reactivation from latently infected neurons in mice. Images PMID:7966571

  16. MicroRNA-373 (miR-373) post-transcriptionally regulates large tumor suppressor, homolog 2 (LATS2) and stimulates proliferation in human esophageal cancer

    SciTech Connect

    Lee, Kuen-Haur; Goan, Yih-Gang; Hsiao, Michael; Lee, Chien-Hsing; Jian, Shu-Huei; Lin, Jen-Tai; Chen, Yuh-Ling; Lu, Pei-Jung

    2009-09-10

    LATS2 is a member of the LATS tumor suppressor family. It has been implicated in regulation of the cell cycle and apoptosis. Frequent loss of heterozygosity (LOH) of LATS2 has been reported in human esophageal cancer. But, the LATS2 gene expression and its regulatory mechanism in esophageal cancer remain unclear. The present study has shown that LATS2 protein expression was mediated by miR-373 at the post-transcriptional level and inversely correlated with miR-373 amounts in esophageal cancer cell lines. Furthermore, we demonstrated that the direct inhibition of LATS2 protein was mediated by miR-373 and manipulated the expression of miR-373 to affect esophageal cancer cells growth. Moreover, this correlation was supported by data collected ex vivo, in which esophageal cancer tissues from esophageal squamous cell carcinoma (ESCC) patients were analyzed. Finally, by miRNA microarray analysis, four miRNAs including miR-373 were over-expressed in ESCC samples. Our findings reveal that miR-373 would be a potential oncogene and it participates in the carcinogenesis of human esophageal cancer by suppressing LATS2 expression.

  17. MicroRNA-373 (miR-373) post-transcriptionally regulates large tumor suppressor, homolog 2 (LATS2) and stimulates proliferation in human esophageal cancer.

    PubMed

    Lee, Kuen-Haur; Goan, Yih-Gang; Hsiao, Michael; Lee, Chien-Hsing; Jian, Shu-Huei; Lin, Jen-Tai; Chen, Yuh-Ling; Lu, Pei-Jung

    2009-09-10

    LATS2 is a member of the LATS tumor suppressor family. It has been implicated in regulation of the cell cycle and apoptosis. Frequent loss of heterozygosity (LOH) of LATS2 has been reported in human esophageal cancer. But, the LATS2 gene expression and its regulatory mechanism in esophageal cancer remain unclear. The present study has shown that LATS2 protein expression was mediated by miR-373 at the post-transcriptional level and inversely correlated with miR-373 amounts in esophageal cancer cell lines. Furthermore, we demonstrated that the direct inhibition of LATS2 protein was mediated by miR-373 and manipulated the expression of miR-373 to affect esophageal cancer cells growth. Moreover, this correlation was supported by data collected ex vivo, in which esophageal cancer tissues from esophageal squamous cell carcinoma (ESCC) patients were analyzed. Finally, by miRNA microarray analysis, four miRNAs including miR-373 were over-expressed in ESCC samples. Our findings reveal that miR-373 would be a potential oncogene and it participates in the carcinogenesis of human esophageal cancer by suppressing LATS2 expression.

  18. Constraining Inert Triplet dark matter by the LHC and FermiLAT

    SciTech Connect

    Ayazi, Seyed Yaser; Firouzabadi, S. Mahdi E-mail: smmfirouz@yahoo.com

    2014-11-01

    We study collider phenomenology of inert triplet scalar dark matter at the LHC. We discuss possible decay of Higgs boson to dark matter candidate and apply current experimental data for invisible Higgs decay and R{sub γγ} to constrain parameter space of our model. We also investigate constraints on dark matter coming from forthcoming measurement, R{sub Zγ} and mono-Higgs production. We analytically calculate the annihilation cross section of dark matter candidate into 2γ and Zγ and then use FermiLAT data to put constraints on parameter space of Inert Triplet Model. We found that this limit can be stronger than the constraints provided by LUX experiment for low mass DM.

  19. Fermi-LAT Gamma-Ray Variability Study of Misaligned AGN

    NASA Astrophysics Data System (ADS)

    Grandi, P.; Torresi, E.; De Rosa, A.; Rainó, S.; Malaguti, G.

    2013-12-01

    We review the gamma-ray variability properties of AGN with a jet not directly pointing at the observer, i.e. Misaligned AGN. This class is mainly populated by nearby low power radio galaxies (i.e. FRIs). The high power radio sources (i.e. FRIIs) are indeed rare in the GeV sky. Our Fermi-LAT inspection of 4 years of data reveals different temporal behaviors, supporting the idea that beaming/jet structural differences could characterize the FRI-FRII jets. The case of 3C111 (FRII) and NGC6251 (FRI) are treated in detail. New insights into the location and dimension of the gamma-ray dissipation regions are provided for galaxies with different radio morphologies.

  20. Extending the Fermi-LAT data processing pipeline to the grid

    SciTech Connect

    Zimmer, S.; Arrabito, L.; Glanzman, T.; Johnson, T.; Lavalley, C.; Tsaregorodtsev, A.

    2015-05-12

    The Data Handling Pipeline ("Pipeline") has been developed for the Fermi Gamma-Ray Space Telescope (Fermi) Large Area Telescope (LAT) which launched in June 2008. Since then it has been in use to completely automate the production of data quality monitoring quantities, reconstruction and routine analysis of all data received from the satellite and to deliver science products to the collaboration and the Fermi Science Support Center. Aside from the reconstruction of raw data from the satellite (Level 1), data reprocessing and various event-level analyses are also reasonably heavy loads on the pipeline and computing resources. These other loads, unlike Level 1, can run continuously for weeks or months at a time. Additionally, it receives heavy use in performing production Monte Carlo tasks.

  1. Detection of a flare at Fermi LAT energies during a multiwavelength campaign on Markarian 180

    NASA Astrophysics Data System (ADS)

    Sbarra, C.; Bastieri, D.; Fermi LAT Collaboration

    2012-11-01

    We present the results of the analysis of Markarian 180 (1ES 1133+704), a BL Lac object embedded in a giant elliptical galaxy, obtained for a period of 45 day, during which multi-wavelength observations were ongoing. The multi-wavelength campaign on Mrk180 was in 2008 (from 2008-10-24 to 2008-12-08) and was coordinated by Stefan Rugamer (MAGIC Collaboration). The Mrk 180 is associated with a quasar-like object whose distance can be determined unambiguously, thanks to the measurement of absorption line that gives the redshift (z=0.046; Ulrich 1978). The source was observed by the LAT of the Fermi satellite, and it was possible to discover a change of flux, at the energies 100 MeV-300 GeV, during the multi-wavelength campaign period. Results of the analysis are shown.

  2. Search for Gamma-Ray Millisecond Pulsars with the Fermi LAT

    NASA Technical Reports Server (NTRS)

    Harding, Alice K.

    2009-01-01

    Prior to the launch of Fermi, only weak gamma-ray pulsations from a single millisecond pulsar, PSR J0218+4232, had been reported. A firm detection of gamma rays from a member of this class of pulsar having periods near neutron star break-up and magnetic dipole moments well below those of normal pulsars would provide new insights into pulsar acceleration and emission. Using accurate ephemerides obtained from several radio telescopes as well as the unprecedented accuracy of the GPS-derived clocks used by Fermi and the LAT, we have searched for gamma-ray pulsations from known pulsars over a broad range of timing parameters. We will present some results from our search for pulsed gamma rays from millisecond pulsars.

  3. MAGNETICALLY AND BARYONICALLY DOMINATED PHOTOSPHERIC GAMMA-RAY BURST MODEL FITS TO FERMI-LAT OBSERVATIONS

    SciTech Connect

    Veres, Peter; Meszaros, Peter; Zhang, Bin-Bin

    2013-02-10

    We consider gamma-ray burst models where the radiation is dominated by a photospheric region providing the MeV Band spectrum, and an external shock region responsible for the GeV radiation via inverse Compton scattering. We parameterize the initial dynamics through an acceleration law {Gamma}{proportional_to}r {sup {mu}}, with {mu} between 1/3 and 1 to represent the range between an extreme magnetically dominated and a baryonically dominated regime, depending also on the magnetic field configuration. We compare these models to several bright Fermi-LAT bursts, and show that both the time-integrated and the time-resolved spectra, where available, can be well described by these models. We discuss the parameters which result from these fits, and discuss the relative merits and shortcomings of the two models.

  4. Constraints on the spectrum of HESS J0632+057 from Fermi-LAT data

    NASA Astrophysics Data System (ADS)

    Malyshev, D.; Chernyakova, M.

    2016-09-01

    We report on the results of ˜7.5 yrs of the very-high energy (10-600 GeV) observations of HESS J0632+057 with Fermi-LAT. In the highest energy band, 200 - 600 GeV, the source is detected with the statistical significance ≳ 4.7σ at orbital phases 0.2 - 0.4 and 0.6 - 0.8 at which HESS J0632+057 is known to demonstrate enhanced emission in TeV energy band. The analysis did not reveal the emission from HESS J0632+057 at lower energies and different orbital phases. Using the upper limits on source's flux we locate the break of the spectrum to >140 GeV and low-energy slope <1.6 (3σ statistical significance).

  5. Comparative health survey of Luangpraot-Tanlium and Marialai communities Lat Krabang district, Bangkok.

    PubMed

    Srilerdfa, Kittiya; Srisamut, Nongnutch; Maiwai, Yuwadee

    2003-09-01

    The objective of the present descriptive study was to investigate the demographic and health status of Thai people in Luangpraot-Tanlium (LPT) and Marialai community (MRL) of Lat Krabang district in Bangkok. These two communities are the pilot project of the "Healthy Community" of Lat Krabang BMA hospital. The total number of households of LPT and MRL are 263 and 240, the population is 957 and 1057, males to female ratio was 1:1.2. The median household income of the residents in both communities is 9,000 baht/month/family. About 49 per cent of people have no health insurance and 22 per cent have social welfare (for underserved population). Both communities are comparable in terms of sex, age, marital status, contraceptive use, history of physical examination, chronic diseases and environmental sanitation. MRL has more trade certificate educational attainment, history of Pap smears and voluntary health insurance than LPT. LPT seemed to be prominent to have more governmental employees and governmental subsidised reimbursement for health care access. People of LPT required health and dental care more often from hospital health teams than MRL. They needed annual health check ups, care for chronic diseases and mosquito eradication. LPT also reported more garbage disposal using the burning method, greater use of rain and tap water and significant poorer sewerage and toilet facility systems when compared with MRL. The reported prevalence of chronic diseases are 1.7 fold higher in MRL than in LPT. Percentage of vaccination coverage (BCG, OPV&DPTI-II-III, HBVI-II-III, Measles vaccine) among children aged less than 1 year was 100 per cent and 1-5 years was 90 per cent (OPV & DPTIV-V).

  6. Fermi-LAT and Suzaku Observations of the Radio Galaxy Centaurus B

    SciTech Connect

    Katsuta, Junichiro; Tanaka, Y.T.; Stawarz, L.; O'Sullivan, S.P.; Cheung, C.C.; Kataoka, J.; Funk, S.; Yuasa, T.; Odaka, H.; Takahashi, T.; Svoboda, J.; /European Space Agency

    2012-08-17

    CentaurusB is a nearby radio galaxy positioned in the Southern hemisphere close to the Galactic plane. Here we present a detailed analysis of about 43 months accumulation of Fermi-LAT data and of newly acquired Suzaku X-ray data for Centaurus B. The source is detected at GeV photon energies, although we cannot completely exclude the possibility that it is an artifact due to incorrect modeling of the bright Galactic diffuse emission in the region. The LAT image provides a weak hint of a spatial extension of the {gamma} rays along the radio lobes, which is consistent with the lack of source variability in the GeV range. We note that the extension cannot be established statistically due to the low number of the photons. Surprisingly, we do not detect any diffuse emission of the lobes at X-ray frequencies, with the provided upper limit only marginally consistent with the previously claimed ASCA flux. The broad-band modeling shows that the observed {gamma}-ray flux of the source may be produced within the lobes, if the diffuse non-thermal X-ray emission component is not significantly below the derived Suzaku upper limit. This association would imply that efficient in-situ acceleration of the ultrarelativistic particles is occurring and that the lobes are dominated by the pressure from the relativistic particles. However, if the diffuse X-ray emission is much below the Suzaku upper limits, the observed {gamma}-ray flux is not likely to be produced within the lobes, but instead within the unresolved core of Centaurus B. In this case, the extended lobes could be dominated by the pressure of the magnetic field.

  7. Fermi LAT detection of renewed GeV gamma-ray activity associated with the flat-spectrum radio source PKS 2247-131

    NASA Astrophysics Data System (ADS)

    Gasparrini, D.

    2016-10-01

    The Large Area Telescope (LAT), on board the Fermi Gamma-ray Space Telescope, has observed a renewed strong gamma-ray activity from a source positionally consistent with the flat-spectrum radio source PKS 2247-131 with coordinates RA=342.4983854 deg, Dec=-12.8546736 deg (J2000; Beasley et al. 2002, ApJS, 141, 13). Fermi-LAT already reported a flare on ATel #9285 but this source is not in any published LAT catalog and was not detected by AGILE or EGRET.

  8. A new treatment for human malignant melanoma targeting L-type amino acid transporter 1 (LAT1): A pilot study in a canine model

    SciTech Connect

    Fukumoto, Shinya; Hanazono, Kiwamu; Fu, Dah-Renn; Endo, Yoshifumi; Kadosawa, Tsuyoshi; Iwano, Hidetomo; Uchide, Tsuyoshi

    2013-09-13

    Highlights: •LAT1 is highly expressed in tumors but at low levels in normal tissues. •We examine LAT1 expression and function in malignant melanoma (MM). •LAT1 expression in MM tissues and cell lines is higher than those in normal tissues. •LAT1 selective inhibitors inhibit amino acid uptake and cell growth in MM cells. •New chemotherapeutic protocols including LAT1 inhibitors are effective for treatment. -- Abstract: L-type amino acid transporter 1 (LAT1), an isoform of amino acid transport system L, transports branched or aromatic amino acids essential for fundamental cellular activities such as cellular growth, proliferation and maintenance. This amino acid transporter recently has received attention because of its preferential and up-regulated expression in a variety of human tumors in contrast to its limited distribution and low-level expression in normal tissues. In this study, we explored the feasibility of using LAT1 inhibitor as a new therapeutic agent for human malignant melanomas (MM) using canine spontaneous MM as a model for human MM. A comparative study of LAT expression was performed in 48 normal tissues, 25 MM tissues and five cell lines established from MM. The study observed LAT1 mRNA levels from MM tissues and cell lines that were significantly (P < 0.01) higher than in normal tissues. Additionally, MM with distant metastasis showed a higher expression than those without distant metastasis. Functional analysis of LAT1 was performed on one of the five cell lines, CMeC-1. [{sup 3}H]L-Leucine uptake and cellular growth activities in CMeC-1 were inhibited in a dose-dependent manner by selective LAT1 inhibitors (2-amino-2-norbornane-carboxylic acid, BCH and melphalan, LPM). Inhibitory growth activities of various conventional anti-cancer drugs, including carboplatin, cyclophosphamide, dacarbazine, doxorubicin, mitoxantrone, nimustine, vinblastine and vincristine, were significantly (P < 0.05) enhanced by combination use with BCH or LPM

  9. Introducing point mutations into the ATGs of the putative open reading frames of the HSV-1 gene encoding the latency associated transcript (LAT) reduces its anti-apoptosis activity.

    PubMed

    Carpenter, Dale; Henderson, Gail; Hsiang, Chinhui; Osorio, Nelson; BenMohamed, Lbachir; Jones, Clinton; Wechsler, Steven L

    2008-02-01

    The herpes simplex virus type 1 (HSV-1) latency associated transcript (LAT) gene has anti-apoptosis activity that directly or indirectly enhances the virus's reactivation phenotype in small animal models. The first 1.5 kb of the primary 8.3 kb LAT is sufficient and some or all of it is necessary for LAT's anti-apoptosis in transient transfection assays and for LAT's ability to enhance the reactivation phenotype. Based on LAT's genomic sequence, the first 1.5 kb contains eight potential open reading frames (ORFs) defined as an ATG followed by an in frame termination codon. In this study, point mutations were introduced into the ATGs of ORFs present in the 1.5 kb fragment of LAT. Mutagenesis of all eight ATGs in LAT ORFs consistently reduced the anti-apoptotic activity of LAT in transiently transfected mouse neuroblastoma cells regardless of whether apoptosis was induced by caspase 8 or caspase 9. Mutation of the six ATGs located in the stable intron sequences within the 1.5 kb LAT had a dramatic effect on caspase 9, but not caspase 8, induced apoptosis. For both caspase 8 and caspase 9 induced apoptosis, mutating the two ATGs in the exon of the LAT 1.5 kb fragment reduced, but did not eliminate the anti-apoptotic activity of LAT. These studies suggest that altering the fine structure of regulatory RNA or expression of a putative LAT ORF regulates the anti-apoptosis activity of LAT. These studies also indicate that more than one function is present in the 1.5 kb LAT fragment.

  10. Isolation and identification of Duck tembusu virus strain lH and development of latex-agglutination diagnostic method for rapid detection of antibodies.

    PubMed

    Wang, Quanxi; Wen, Yaping; Yifan Huang; Wu, Yijian; Cai, Yilong; Xu, Lihui; Wang, Changkang; Li, Ang; Wu, Baocheng; Chen, Jilong

    2014-12-01

    SUMMARY. An outbreak of egg-drop syndrome occurred on a Sheldrake duck farm in Longhai in Fujian Province, China, in 2012. The main clinical symptoms were sharply reduced egg production, crooked necks, and death. We isolated the virus from the sick ducks, identified it, and observed the histopathologic changes after viral infection. We detected viral RNA in the blood and feces of the infected ducks and developed a latex-agglutination diagnostic method to detect anti-Tembusu-virus antibodies. Our results show that the pathogenic virus is a Tembusu virus. The histopathologic changes included follicular cell degeneration and necrosis, follicular cavity filled with blood cells, massive necrosis in the brain, and degeneration and necrosis of the nerve and glial cells. When the transmission of the virus in the infected ducks was studied, the duck blood was positive for viral nucleic acid for up to 29 days, and the feces were positive for viral nucleic acid for up to 13 days. We successfully established a simple, rapid, and easy- to-use latex-agglutination diagnostic method for the detection of antibodies against duck Tembusu virus. PMID:25619007

  11. HdhCTL1 is a novel C-type lectin of abalone Haliotis discus hannai that agglutinates Gram-negative bacterial pathogens.

    PubMed

    Zhang, Jian; Qiu, Reng; Hu, Yong-hua

    2014-12-01

    C-type lectins (CTLs) are Ca(2+)-dependent carbohydrate recognition proteins, which play important roles in the innate immunity of both vertebrates and invertebrates. In this study, we identified and characterized a C-type lectin (named HdhCTL1) from Pacific abalone, Haliotis discus hannai. HdhCTL1 is composed of 176 amino acid residues and shares low (23.9%) identity with the known CTL of abalone. HdhCTL1 possesses a putative signal peptide and a carbohydrate-recognition domain (CRD) typical of CTLs. The CRD of HdhCTL1 contains four disulfide bond-forming cysteine residues that are highly conserved in CTLs. HdhCTL1 mRNA was detected in a wide range of tissues and expressed abundantly in the digestive gland. Experimental infection with the bacterial pathogen Vibrio anguillarum significantly upregulated HdhCTL1 expression in a time-dependent manner. Recombinant HdhCTL1 (rHdhCTL1) purified from Escherichia coli was able to agglutinate Gram-negative bacterial pathogens. The agglutinating ability of rHdhCTL1 was abolished in the presence of mannose. These results suggest that HdhCTL1 is a novel CTL which is likely to be involved in host defense against bacterial infection. PMID:25301718

  12. HdhCTL1 is a novel C-type lectin of abalone Haliotis discus hannai that agglutinates Gram-negative bacterial pathogens.

    PubMed

    Zhang, Jian; Qiu, Reng; Hu, Yong-hua

    2014-12-01

    C-type lectins (CTLs) are Ca(2+)-dependent carbohydrate recognition proteins, which play important roles in the innate immunity of both vertebrates and invertebrates. In this study, we identified and characterized a C-type lectin (named HdhCTL1) from Pacific abalone, Haliotis discus hannai. HdhCTL1 is composed of 176 amino acid residues and shares low (23.9%) identity with the known CTL of abalone. HdhCTL1 possesses a putative signal peptide and a carbohydrate-recognition domain (CRD) typical of CTLs. The CRD of HdhCTL1 contains four disulfide bond-forming cysteine residues that are highly conserved in CTLs. HdhCTL1 mRNA was detected in a wide range of tissues and expressed abundantly in the digestive gland. Experimental infection with the bacterial pathogen Vibrio anguillarum significantly upregulated HdhCTL1 expression in a time-dependent manner. Recombinant HdhCTL1 (rHdhCTL1) purified from Escherichia coli was able to agglutinate Gram-negative bacterial pathogens. The agglutinating ability of rHdhCTL1 was abolished in the presence of mannose. These results suggest that HdhCTL1 is a novel CTL which is likely to be involved in host defense against bacterial infection.

  13. Low level of LAT-PLC-γ1 interaction is associated with Th2 polarized differentiation: a contributing factor to the etiology of asthma.

    PubMed

    Peng, Xiaohua; Cui, Zhilei; Gu, Wen; Xu, Weiguo; Guo, Xuejun

    2014-07-01

    Linker for activation of T cells (LAT) is a key adaptor in the T cell receptor (TCR) signaling pathway. The expression of LAT is lower in asthmatic patients than that in healthy people, but there is little knowledge about the mechanism underlying this phenomenon. This study was aimed to determine whether LAT-PLC-γ1 interaction was involved in the development of asthma. It was shown that the phosphorylation of PLC-γ1 decreased in the asthmatic mouse model and Th2 cell differentiated CD4(+) T cells. In addition, depleted endogenous PLC-γ1 promoted CD4(+) T cells to differentiate into IL-4-Productor. It was therefore concluded that the low level of LAT-PLC-γ1 interaction was associated with Th2 polarized differentiation, and this may contribute to the etiology of asthma.

  14. Molecular events involved in up-regulating human Na+-independent neutral amino acid transporter LAT1 during T-cell activation.

    PubMed

    Nii, T; Segawa, H; Taketani, Y; Tani, Y; Ohkido, M; Kishida, S; Ito, M; Endou, H; Kanai, Y; Takeda, E; Miyamoto Ki

    2001-09-15

    We investigated the regulation of system-L amino acid transporter (LAT1) during T-cell activation. In quiescent T-cells, L-leucine transport is mediated mainly by the system-L amino acid transport system and is increased significantly during T-cell activation by PMA and ionomycin. In quiescent T-cells, the LAT1 protein was heterocomplexed with 4F2 heavy chain (4F2hc) in the plasma membrane. During T-cell activation, the amounts of 4F2hc and LAT1 heterocomplex were significantly elevated compared with those in quiescent T-cells. In addition, by Northern-blot analysis, these increments were found to be due to elevated levels of LAT1 and 4F2hc mRNA. Transient expression of constructs comprising various LAT1 gene promoter fragments, which contained all three of the GC boxes, was sufficient for promoting luciferase expression in Jurkat T-cells, but the promoter of the LAT1 gene did not respond to PMA and ionomycin. Similar observations were observed in the human 4F2hc gene promoter. In nuclear run-on assay, the LAT1 and 4F2hc genes were actively transcribed even in quiescent T-cells, but the low levels of both transcripts were shown to be the result of a block to transcription elongation within the exon 1 intron 1 regions. These findings indicated that a removal of the block to mRNA elongation stimulates the induction of system-L amino acid transporter gene transcripts (LAT1 and 4F2hc) in activated T-cells. PMID:11535130

  15. The half-life of the HSV-1 1.5-kb LAT intron is similar to the half-life of the 2.0-kb LAT intron.

    PubMed

    Brinkman, Kerry K; Mishra, Prakhar; Fraser, Nigel W

    2013-02-01

    Herpes simplex virus type 1 establishes a latent infection in the sensory neurons of the peripheral nervous system of humans. Although about 80 genes are expressed during the lytic cycle of the virus infection, essentially only one gene is expressed during the latent cycle. This gene is known as the latency-associated transcript (LAT), and it appears to play a role in the latency cycle through an anti-apoptotic function in the 5' end of the gene and miRNA encoded along the length of the transcript which downregulate some of the viral immediate-early gene products. The LAT gene is about 8.3 kb long and consists of two exons separated by an unusual intron. The intron between the exons consists of two nested introns. This arrangement of introns has been called a twintron. Furthermore, the larger (2 kb) intron has been shown to be very stable. In this study, we measure the stability of the shorter 1.5-kb nested intron and find its half-life is similar to the longer intron. This was achieved by deleting the 0.5-kb overlapping intron from a plasmid construct designed to express the LAT transcript from a tet-inducible promoter and measuring the half-life of the 1.5-kb intron in tissue culture cells. This finding supports the hypothesis that it is the common branch-point region of these nested introns that is responsible for their stability.

  16. The half-life of the HSV-1 1.5-kb LAT intron is similar to the half-life of the 2.0-kb LAT intron.

    PubMed

    Brinkman, Kerry K; Mishra, Prakhar; Fraser, Nigel W

    2013-02-01

    Herpes simplex virus type 1 establishes a latent infection in the sensory neurons of the peripheral nervous system of humans. Although about 80 genes are expressed during the lytic cycle of the virus infection, essentially only one gene is expressed during the latent cycle. This gene is known as the latency-associated transcript (LAT), and it appears to play a role in the latency cycle through an anti-apoptotic function in the 5' end of the gene and miRNA encoded along the length of the transcript which downregulate some of the viral immediate-early gene products. The LAT gene is about 8.3 kb long and consists of two exons separated by an unusual intron. The intron between the exons consists of two nested introns. This arrangement of introns has been called a twintron. Furthermore, the larger (2 kb) intron has been shown to be very stable. In this study, we measure the stability of the shorter 1.5-kb nested intron and find its half-life is similar to the longer intron. This was achieved by deleting the 0.5-kb overlapping intron from a plasmid construct designed to express the LAT transcript from a tet-inducible promoter and measuring the half-life of the 1.5-kb intron in tissue culture cells. This finding supports the hypothesis that it is the common branch-point region of these nested introns that is responsible for their stability. PMID:23335177

  17. Analysis of the cumulative neutrino flux from Fermi LAT blazar populations using 3 years of IceCube data

    NASA Astrophysics Data System (ADS)

    Glüsenkamp, Thorsten

    2016-07-01

    The recent discovery of a diffuse neutrino flux up to PeV energies raises the question of which populations of astrophysical sources contribute to this diffuse signal. One extragalactic candidate source population to produce high-energy neutrinos are Blazars. We present results from a likelihood analysis searching for cumulative neutrino emission from Blazar populations selected with the 2nd Fermi LAT AGN catalogue (2LAC) using an IceCube data set that has been optimized for the detection of individual sources. In contrast to previous searches with IceCube, the investigated populations contain up to hundreds of sources, the biggest one being the entire Blazar sample measured by the Fermi-LAT. No significant neutrino signal was found from any of these populations. Some implications of this non-observation for the origin of the observed PeV diffuse signal will be discussed.

  18. MAP4K family kinases act in parallel to MST1/2 to activate LATS1/2 in the Hippo pathway

    PubMed Central

    Meng, Zhipeng; Moroishi, Toshiro; Mottier-Pavie, Violaine; Plouffe, Steven W.; Hansen, Carsten G.; Hong, Audrey W.; Park, Hyun Woo; Mo, Jung-Soon; Lu, Wenqi; Lu, Shicong; Flores, Fabian; Yu, Fa-Xing; Halder, Georg; Guan, Kun-Liang

    2015-01-01

    The Hippo pathway plays a central role in tissue homoeostasis, and its dysregulation contributes to tumorigenesis. Core components of the Hippo pathway include a kinase cascade of MST1/2 and LATS1/2 and the transcription co-activators YAP/TAZ. In response to stimulation, LATS1/2 phosphorylate and inhibit YAP/TAZ, the main effectors of the Hippo pathway. Accumulating evidence suggests that MST1/2 are not required for the regulation of YAP/TAZ. Here we show that deletion of LATS1/2 but not MST1/2 abolishes YAP/TAZ phosphorylation. We have identified MAP4K family members—Drosophila Happyhour homologues MAP4K1/2/3 and Misshapen homologues MAP4K4/6/7—as direct LATS1/2-activating kinases. Combined deletion of MAP4Ks and MST1/2, but neither alone, suppresses phosphorylation of LATS1/2 and YAP/TAZ in response to a wide range of signals. Our results demonstrate that MAP4Ks act in parallel to and are partially redundant with MST1/2 in the regulation of LATS1/2 and YAP/TAZ, and establish MAP4Ks as components of the expanded Hippo pathway. PMID:26437443

  19. The host galaxy and Fermi-LAT counterpart of HESS J1943+213

    NASA Astrophysics Data System (ADS)

    Peter, D.; Domainko, W.; Sanchez, D. A.; van der Wel, A.; Gässler, W.

    2014-11-01

    Context. The very-high energy (VHE, E> 100 GeV) gamma-ray sky shows diverse Galactic and extragalactic source populations. For some sources the astrophysical object class could not be identified so far. Aims: The nature (Galactic or extragalactic) of the VHE gamma-ray source HESS J1943+213 is explored. We specifically investigate the proposed near-infrared counterpart 2MASS J19435624+2118233 of HESS J1943+213 and investigate the implications of a physical association. Methods: We present K-band imaging from the 3.5 m CAHA telescope of 2MASS J19435624+2118233. Furthermore, 5 years of Fermi-LAT data were analyzed to search for a high-energy (HE, 100 MeV LAT a HE counterpart is found with a power-law spectrum above 1 GeV, with a normalization of (3.0 ± 0.8stat ± 0.6sys) × 10-15 cm-2 s-1 MeV-1 at the decorrelation energy Edec = 15.1 GeV and a spectral index of Γ = 1.59 ± 0.19stat ± 0.13sys. This gamma-ray spectrum shows a rather sharp break between the HE and VHE regimes of ΔΓ = 1.47 ± 0.36. Conclusions: The infrared and HE data strongly favor an extragalactic origin of HESS J1943+213, where the infrared counterpart traces the host galaxy of an extreme blazar and where the rather sharp spectral break between the HE and VHE regime indicates attenuation on extragalactic background light. The

  20. Fermi-LAT detection of a renewed fast gamma-ray activity from PKS 1824-582

    NASA Astrophysics Data System (ADS)

    Cutini, Sara

    2016-09-01

    The Large Area Telescope (LAT), one of the two instruments on the Fermi Gamma-ray Space Telescope, has observed significant gamma-ray emission from a source positionally consistent with the extragalactic radio source PKS 1824-582 with coordinates RA=18h29m12.4023s, Dec=-58d13m55.161s (J2000; Fey et al. 2006, AJ, 132, 1944).

  1. Fermi LAT detection of a GeV gamma-ray flare from the BL Lac object AP Librae

    NASA Astrophysics Data System (ADS)

    Ciprini, Stefano

    2016-08-01

    The Large Area Telescope (LAT), one of the two instruments on the Fermi Gamma-ray Space Telescope, has observed increasing gamma-ray flux from a source positionally consistent with the BL Lac object AP Lib (also known as PKS 1514-24 and 3FGL J1517.6-2422), with radio counterpart position R.A.: 229.424221 deg, Dec.: -24.372076 deg, (J2000.0, Johnston et al. 1995, AJ, 110, 880).

  2. Fermi LAT detection of increasing gamma-ray activity from NGC 1275 and B3 0908+416B

    NASA Astrophysics Data System (ADS)

    Pivato, G.; Buson, S.

    2015-10-01

    The Large Area Telescope (LAT), one of the two instruments on the Fermi Gamma-ray Space Telescope, has observed increasing gamma-ray flux from sources positionally consistent with the flat spectrum radio quasar B3 0908+416B (also known as 3FGL J0912.2+4126, Acero et al. 2015 ApJS, 218, 23) and the radio galaxy NGC 1275 (also known as Perseus A and 3FGL J0319.8+4130).

  3. Fermi LAT detection of renewed GeV gamma-ray activity from blazar AO 0235+164

    NASA Astrophysics Data System (ADS)

    Ciprini, Stefano

    2015-09-01

    The Large Area Telescope (LAT), one of two instruments on the Fermi Gamma-ray Space Telescope, has observed flaring gamma-ray emission from a source positionally consistent with the blazar AO 0235+164 (also known as OD 160, PKS 0235+164, 1ES 0235+164 and 3FGL J0238.6+1636), with radio coordinates (J2000) R.A.: 39.662209 deg, Dec.: 16.616465 deg.

  4. Fermi LAT detection of a GeV flare from blazar NRAO 190 (PKS 0440-00)

    NASA Astrophysics Data System (ADS)

    Buson, S.; Gasparrini, D.

    2013-06-01

    The Large Area Telescope (LAT), one of the two instruments on the Fermi Gamma-ray Space Telescope, observed a gamma-ray outburst from a source positionally consistent with the flat spectrum radio quasar NRAO 190 (also known as PKS 0440-00, DA 145, OF -067; RA: 04h 42m 38.661s, Dec: -00d 17m 43.42s, J2000.0) with redshift 0.844 (Hewitt & Burbidge 1987, 63, 1).

  5. On your mark, get set, GROW! LePRK2-LAT52 interactions regulate pollen tube growth.

    PubMed

    Johnson, Mark A; Preuss, Daphne

    2003-03-01

    Recent discoveries show that LAT52 and LePRK2, two pollen-specific proteins, interact in what might be an autocrine signaling system. This exciting finding indicates that successful fertilization requires ligand-receptor kinase signals that regulate pollen-tube growth. The stage is now set to identify other components of this pathway and to explore their connections with the many signals exchanged between pollen and pistil.

  6. Phosphorylation of CHO1 by Lats1/2 regulates the centrosomal activation of LIMK1 during cytokinesis

    PubMed Central

    Okamoto, Ayumi; Yabuta, Norikazu; Mukai, Satomi; Torigata, Kosuke; Nojima, Hiroshi

    2015-01-01

    Large tumor suppressor 1 and 2 (Lats1/2) regulate centrosomal integrity, chromosome segregation and cytokinesis. As components of the centralspindlin complex, the kinesin-like protein CHO1 and its splicing variant MKLP1 colocalize with chromosome passenger proteins and GTPases and regulate the formation of the contractile ring and cytokinesis; however, the regulatory mechanisms of CHO1/MKLP1 remain elusive. Here, we show that Lats1/2 phosphorylate Ser716 in the F-actin-interacting region of CHO1, which is absent in MKLP1. Phosphorylated CHO1 localized to the centrosomes and midbody, and the actin polymerization factor LIM-kinase 1 (LIMK1) was identified as its binding partner. Overexpression of constitutively phosphorylated and non-phosphorylated CHO1 altered the mitotic localization and activation of LIMK1 at the centrosomes in HeLa cells, leading to the inhibition of cytokinesis through excessive phosphorylation of Cofilin and mislocalization of Ect2. These results suggest that Lats1/2 stringently control cytokinesis by regulating CHO1 phosphorylation and the mitotic activation of LIMK1 on centrosomes. PMID:25786116

  7. LATS-YAP/TAZ controls lineage specification by regulating TGFβ signaling and Hnf4α expression during liver development

    PubMed Central

    Lee, Da-Hye; Park, Jae Oh; Kim, Tae-Shin; Kim, Sang-Kyum; Kim, Tack-hoon; Kim, Min-chul; Park, Gun Soo; Kim, Jeong-Hwan; Kuninaka, Shinji; Olson, Eric N.; Saya, Hideyuki; Kim, Seon-Young; Lee, Ho; Lim, Dae-Sik

    2016-01-01

    The Hippo pathway regulates the self-renewal and differentiation of various adult stem cells, but its role in cell fate determination and differentiation during liver development remains unclear. Here we report that the Hippo pathway controls liver cell lineage specification and proliferation separately from Notch signalling, using mice and primary hepatoblasts with liver-specific knockout of Lats1 and Lats2 kinase, the direct upstream regulators of YAP and TAZ. During and after liver development, the activation of YAP/TAZ induced by loss of Lats1/2 forces hepatoblasts or hepatocytes to commit to the biliary epithelial cell (BEC) lineage. It increases BEC and fibroblast proliferation by up-regulating TGFβ signalling, but suppresses hepatoblast to hepatocyte differentiation by repressing Hnf4α expression. Notably, oncogenic YAP/TAZ activation in hepatocytes induces massive p53-dependent cell senescence/death. Together, our results reveal that YAP/TAZ activity levels govern liver cell differentiation and proliferation in a context-dependent manner. PMID:27358050

  8. Gamma-Ray Observations of the Supernova Remnant RX J0852.0-4622 with the Fermi LAT

    SciTech Connect

    Tanaka, T.; Allafort, A.; Ballet, J.; Funk, S.; Giordano, F.; Hewitt, J.; Lemoine-Goumard, M.; Tajima, H.; Tibolla, O.; Uchiyama, Y.; /Stanford U., HEPL /KIPAC, Menlo Park

    2011-12-13

    We report on gamma-ray observations of the supernova remnant (SNR) RX J0852.0-4622 with the Large Area Telescope (LAT) aboard the Fermi Gamma-ray Space Telescope. In the Fermi LAT data, we find a spatially extended source at the location of the SNR. The extension is consistent with the SNR size seen in other wavelengths such as X-rays and TeV gamma rays, leading to the identification of the gamma-ray source with the SNR. The spectrum is well described as a power law with a photon index of {Lambda} = 1.85 {+-} 0.06 (stat){sub -0.19}{sup +0.18} (sys), which smoothly connects to the H.E.S.S. spectrum in the TeV energy band. We discuss the gamma-ray emission mechanism based on multiwavelength data. The broadband data can be fit well by a model in which the gamma rays are of hadronic origin. We also consider a scenario with inverse Compton scattering of electrons as the emission mechanism of the gamma rays. Although the leptonic model predicts a harder spectrum in the Fermi LAT energy range, the model can fit the data considering the statistical and systematic errors.

  9. The adaptor molecules LAT and SLP-76 are specifically targeted by Yersinia to inhibit T cell activation

    PubMed Central

    Gerke, Christiane; Falkow, Stanley; Chien, Yueh-hsiu

    2005-01-01

    T cell responses are critical to the survival of Yersinia-infected animals. Yersinia have the ability to directly suppress T lymphocyte activation through the virulence factor YopH, a tyrosine phosphatase. Using single cell video microscopy and FACS analysis, here we show that even an average of one Yersinia per T cell is sufficient to inhibit or alter T cell responses. This efficient inhibition is traced to specific targeting by YopH of the adaptor proteins, linker for activation of T cells (LAT) and SH2-domain–containing leukocyte protein of 76 kD (SLP-76), which are crucial for T cell antigen receptor (TCR) signaling. A catalytically inactive YopH translocated via the type III secretory pathway from the bacteria into T cells primarily binds to LAT and SLP-76. Furthermore, among the proteins of the TCR signaling pathway, the tyrosine phosphorylation levels of LAT and SLP-76 are the most affected in T cells exposed to low numbers of Yersinia pseudotuberculosis. This is the first example showing that a pathogen targets these adaptor proteins in the TCR signaling pathway, suggesting a novel mechanism by which pathogens may efficiently alter T cell–mediated immune responses. PMID:15699071

  10. Phosphotyrosine-mediated LAT assembly on membranes drives kinetic bifurcation in recruitment dynamics of the Ras activator SOS.

    PubMed

    Huang, William Y C; Yan, Qingrong; Lin, Wan-Chen; Chung, Jean K; Hansen, Scott D; Christensen, Sune M; Tu, Hsiung-Lin; Kuriyan, John; Groves, Jay T

    2016-07-19

    The assembly of cell surface receptors with downstream signaling molecules is a commonly occurring theme in multiple signaling systems. However, little is known about how these assemblies modulate reaction kinetics and the ultimate propagation of signals. Here, we reconstitute phosphotyrosine-mediated assembly of extended linker for the activation of T cells (LAT):growth factor receptor-bound protein 2 (Grb2):Son of Sevenless (SOS) networks, derived from the T-cell receptor signaling system, on supported membranes. Single-molecule dwell time distributions reveal two, well-differentiated kinetic species for both Grb2 and SOS on the LAT assemblies. The majority fraction of membrane-recruited Grb2 and SOS both exhibit fast kinetics and single exponential dwell time distributions, with average dwell times of hundreds of milliseconds. The minor fraction exhibits much slower kinetics, extending the dwell times to tens of seconds. Considering this result in the context of the multistep process by which the Ras GEF (guanine nucleotide exchange factor) activity of SOS is activated indicates that kinetic stabilization from the LAT assembly may be important. This kinetic proofreading effect would additionally serve as a stochastic noise filter by reducing the relative probability of spontaneous SOS activation in the absence of receptor triggering. The generality of receptor-mediated assembly suggests that such effects may play a role in multiple receptor proximal signaling processes.

  11. Characterizing high-energy light curves of Fermi/Lat GRBs

    SciTech Connect

    Gillette, Jarred

    2015-08-21

    A systematic analysis of the light curves of Gamma-Ray Burst (GRBs) with redshift and detected at high-energy (> 100 MeV) by Fermi/LAT has never been done before our work, because there were only a handful of detections. Now we have 20 of those, which we can use to characterize the GRBs in their rest frame. We compared a characteristic decay times Tc of GRBs with redshifts using the new “Pass 8” data, and used a Crystal Ball function to parametrize GRB characteristics. An unexpected anti-correlation between Tc and the peak flux was observed. This means that brighter peaked GRBs have shorter durations. There is also no correlation between the Tc and the decay index, which makes the anti-correlation with brightness more clear. This results appears to be consistent with the External Shock model, which is one of the competing hypothesis on the origin of the high-energy emission. We did not observe any bimodality, which is seen in GRBs at lower energies.

  12. Fermi LAT upper limits on gamma-ray emission from colliding wind binaries

    NASA Astrophysics Data System (ADS)

    Werner, M.; Reimer, O.; Reimer, A.; Egberts, K.

    2012-12-01

    Colliding wind binaries (CWBs) are thought to give rise to a plethora of physical processes including acceleration and interaction of relativistic particles. Consequently, CWBs have been considered as putative gamma-ray emitters since the COS-B era. On the basis of 24 months of Fermi-LAT data, seven CWB systems are analyzed: WR 11, WR 70, WR 125, WR 137, WR 140, WR 146 and WR 147. Specific theoretical predictions for the gamma-ray emission of CWBs identify these systems as the most promising candidates among known WR-binaries due to their respective stellar and orbital parameters. We find no evidence of gamma-ray emission from any of the studied CWB systems and flux upper limits are determined. In some of the studied CWBs the interplay of orbital and stellar parameters render the Fermi data as not sufficiently sensitive to constrain parameters of the emission model. In others large uncertainties in input parameters of the gamma-ray emission model yield a large variance among model parameters that can be accommodated by the data. However, in the case of WR 140 and WR 147, the Fermi upper limits appear to rule out some early model predictions and constrain later theoretical models over a significant parameter space.

  13. PAMELA and Fermi LAT signals from long-lived Kaluza-Klein dark matter

    SciTech Connect

    Okada, Nobuchika; Yamada, Toshifumi

    2009-10-01

    We propose a simple extension of the minimal universal extra dimension model by introducing a small curvature. The model is formulated as a small anti-de Sitter curvature limit of the five-dimensional standard model (SM) in the Randall-Sundrum background geometry. While the lightest Kaluza-Klein (KK) particle can be thermal relic dark matter as usual in the universal extra dimension model, the KK parity is explicitly broken in the presence of the small curvature and the KK dark matter decays into the SM fermions with a long lifetime. Couplings of the KK dark matter with SM fermion pairs in the five-dimensional bulk are controlled by fermion bulk masses. By tuning bulk masses of quarks, we can suppress KK dark matter decay into quarks. With a suitable choice of bulk masses for leptons, KK dark matter decay into leptons can account for the cosmic-ray electron/positron excesses reported by the recent PAMELA and Fermi LAT satellite experiments.

  14. Characterizing high-energy light curves of Fermi/LatGRBs - Oral Presentation

    SciTech Connect

    Gillette, Jarred

    2015-08-23

    A systematic analysis of the light curves of Gamma-Ray Burst (GRBs) with redshift and detected at high-energy (> 100 MeV) by Fermi/LAT has never been done before our work, because there were only a handful of detections. Now we have 20 of those, which we can use to characterize the GRBs in their rest frame. We compared a characteristic decay times Tc of GRBs with redshifts using the new "Pass8" data, and used a Crystal Ball function to parametrize GRB characteristics. An unexpected anti-correlation between Tc and the peak flux was observed. This means that brighter peaked GRBs have shorter durations. There is also no correlation between Tc and the decay index, which is one of the competing hypothesis on the origin of the high-energy emission. We did not observe any bimodality, which is seen in GRBs at lower energies.

  15. Implications of Fermi-LAT observations on the origin of IceCube neutrinos

    SciTech Connect

    Wang, Bin; Li, Zhuo; Zhao, Xiaohong E-mail: zhaoxh@ynao.ac.cn

    2014-11-01

    The IceCube (IC) collaboration recently reported the detection of TeV-PeV extraterrestrial neutrinos whose origin is yet unknown. By the photon-neutrino connection in pp and pγ interactions, we use the Fermi-LAT observations to constrain the origin of the IC detected neutrinos. We find that Galactic origins, i.e., the diffuse Galactic neutrinos due to cosmic ray (CR) propagation in the Milky Way, and the neutrinos from the Galactic point sources, may not produce the IC neutrino flux, thus these neutrinos should be of extragalactic origin. Moreover, the extragalactic gamma-ray bursts (GRBs) may not account for the IC neutrino flux, the jets of active galactic nuclei may not produce the IC neutrino spectrum, but the starburst galaxies (SBGs) may be promising sources. As suggested by the consistency between the IC detected neutrino flux and the Waxman-Bahcall bound, GRBs in SBGs may be the sources of both the ultrahigh energy, ∼> 10{sup 19}eV, CRs and the 1–100 PeV CRs that produce the IC detected TeV-PeV neutrinos.

  16. Anisotropies in the Diffuse Gamma-Ray Background Measured by the Fermi LAT

    NASA Technical Reports Server (NTRS)

    Ferrara, E. C.; McEnery, J. E.; Troja, E.

    2012-01-01

    The contribution of unresolved sources to the diffuse gamma-ray background could induce anisotropies in this emission on small angular scales. We analyze the angular power spectrum of the diffuse emission measured by the Fermi LAT at Galactic latitudes absolute value of b > 30 deg in four energy bins spanning 1 to 50 GeV. At multipoles l >= 155, corresponding to angular scales approx < 2 deg, angular power above the photon noise level is detected at > 99.99% CL in the 1-2 GeV, 2- 5 GeV, and 5- 10 GeV energy bins, and at > 99% CL at 10-50 GeV. Within each energy bin the measured angular power takes approximately the same value at all multipoles l >= 155, suggesting that it originates from the contribution of one or more unclustered source populations. The amplitude of the angular power normalized to the mean intensity in each energy bin is consistent with a constant value at all energies, C(sub p) / (I)(exp 2) = 9.05 +/- 0.84 x 10(exp -6) sr, while the energy dependence of C(sub p) is consistent with the anisotropy arising from one or more source populations with power-law photon spectra with spectral index Gamma (sub s) = 2.40 +/- 0.07. We discuss the implications of the measured angular power for gamma-ray source populations that may provide a contribution to the diffuse gamma-ray background.

  17. Agglutinated foraminifera from the Sydney Coalfield, Nova Scotia: Their use as indicators of sea-level changes in Carboniferous coal-bearing strata

    SciTech Connect

    Wightman, W.G.; Scott, D.B.; Medioli, F.M.; Gibling, M.R. . Centre for Marine Geology)

    1992-01-01

    Agglutinated foraminifera and arcellaceans (the camoebians) were examined from Carboniferous (Late Westphalian-Stephanian) cyclothems in the Sydney Basin of Nova Scotia. Their presence confirms that the laterally extensive coal seams, limestones, mudstones and carbonaceous shales were deposited in a paralic setting. Four distinctive assemblages are documented from the coal-bearing strata, and these may be used as accurate paleo sea-level indicators on the basis of the modern distribution of similar assemblages. Mixed assemblages dominated by Ammobaculites characterize siltstones overlying the coal seams, an association typical of mineralic substrates within modern estuarine environments. Assemblages dominated by small, finely agglutinated specimens of Ammotium and Ammobaculites occur in organic rich strata between coal seam splits. Similar assemblages are found in modern salt marshes and upper estuarine settings. Trochammina dominated assemblages occur in mudstones underlying the coal seams. Such assemblages are typical of higher elevations in modern brackish and saline marshes. Monotypic assemblages of the arcellacean Difflugia are also found in the seat earths below coal seams. Similar associations occur today in mineralic substrates below modern freshwater floating marshes. The presence of a Trochammina assemblage has aided recognition of a maximum flooding (transgression) surface below the base of an incised paleovalley, interpreted as a type 1 sequence boundary, in the Bonar cyclothem of the Sydney Basin. The valley incision is attributed to glacioeustatic sea-level lowering. The upper 10m of the 25m thick valley fill contains assemblages of Difflugia, which are succeeded by Trochammina assemblages within the seat earth beneath the coal at the top of the cyclothem.

  18. Mechanistic Evaluation for Mixed-field Agglutination in the K562 Cell Study Model with Exon 3 Deletion of A1 Gene.

    PubMed

    Chen, Ding-Ping; Tseng, Ching-Ping; Lin, Chi-Jui; Wang, Wei-Ting; Sun, Chien-Feng

    2015-01-01

    In the case of blood type B3 with typical mixed-field agglutination of RBCs in the presence of anti-B or anti-AB antibody, a number of genetic alternations have been reported. It is well known that the IVS3+5G→A mutation in the B gene destroys the consensus of the splice donor site leading to exon 3 skipping during mRNA splicing. The lack of exon 3 likely causes a short stem region, producing an unstable B3 protein, and is concomitant with a decrease in B3 protein expression. Whether the phenomenon also appears in the type A blood group is of question. In this study, we evaluate whether exon 3 deletion in the blood type A gene also results in mixed-field phenotype. Site-directed mutagenesis was used to generate cDNA encoding A1 gene with exon 3 deletion. The cDNA was stably expressed in K562 cells. The expression of A antigen was compared with expression in parental K562 cells that did not express A antigen and in the stable K562 cell line expressing A(1) cDNA by flow cytometry analyses. The expression of A antigen in A1 stable cells and parental K562 cells was set as 100% and 0%, respectively. The mean relative percentage of A antigen expression for the cells of A1 with exon 3 deletion was 59.9% of A1 stable cells. Consistent with the observations of B3, which is B gene with exon 3 deletion, mixed field agglutination was observed for the cells expressing A1 with exon 3 deletion. Exon 3 deletion results in mixed field phenotype in both type A and B RBCs. However, the degree of antigen expression change for exon 3 deletion in A gene was less severe when compared with the deletion occurred in B gene. PMID:26663798

  19. Brightest Fermi-LAT flares of PKS 1222+216: implications on emission and acceleration processes

    SciTech Connect

    Kushwaha, Pankaj; Singh, K. P.; Sahayanathan, Sunder

    2014-11-20

    We present a high time resolution study of the two brightest γ-ray outbursts from a blazar PKS 1222+216 observed by the Fermi Large Area Telescope (LAT) in 2010. The γ-ray light curves obtained in four different energy bands, 0.1-3, 0.1-0.3, 0.3-1, and 1-3 GeV, with time bins of six hours, show asymmetric profiles with similar rise times in all the bands but a rapid decline during the April flare and a gradual one during the June flare. The light curves during the April flare show an ∼2 day long plateau in 0.1-0.3 GeV emission, erratic variations in 0.3-1 GeV emission, and a daily recurring feature in 1-3 GeV emission until the rapid rise and decline within a day. The June flare shows a monotonic rise until the peak, followed by a gradual decline powered mainly by the multi-peak 0.1-0.3 GeV emission. The peak fluxes during both the flares are similar except in the 1-3 GeV band in April, which is twice the corresponding flux during the June flare. Hardness ratios during the April flare indicate spectral hardening in the rising phase followed by softening during the decay. We attribute this behavior to the development of a shock associated with an increase in acceleration efficiency followed by its decay leading to spectral softening. The June flare suggests hardening during the rise followed by a complicated energy dependent behavior during the decay. Observed features during the June flare favor multiple emission regions while the overall flaring episode can be related to jet dynamics.

  20. Fermi-LAT Constraints on the Pulsar Wind Nebula Nature of HESS J1857+026

    NASA Technical Reports Server (NTRS)

    Rousseau, R.; Grondin, M.-H.; VanEtten, A.; Lemoine-Goumard, M.; Bogdanov, S.; Hessels, J. W. T.; Kaspi, V. M.; Arzoumanian, Z.; Camilo, F.; Casandjian, J. M.; Espinoza, C. M.; Johnston, S.; Lyne, A. G.; Smith, D. A.; Stappers, B. W.; Caliandro, G. A.

    2012-01-01

    Since its launch, the Fermi satellite has firmly identified 5 pulsar wind nebulae plus a large number of candidates, all powered by young and energetic pulsars. HESS J1857+026 is a spatially extended gamma-ray source detected by H.E.S.S. and classified as a possible pulsar wind nebula candidate powered by PSR J1856+0245. Aims. We search for -ray pulsations from PSR J1856+0245 and explore the characteristics of its associated pulsar wind nebula. Methods. Using a rotational ephemeris obtained from the Lovell telescope at Jodrell Bank Observatory at 1.5 GHz, we phase.fold 36 months of gamma-ray data acquired by the Large Area Telescope (LAT) aboard Fermi. We also perform a complete gamma-ray spectral and morphological analysis. Results. No pulsation was detected from PSR J1856+0245. However, significant emission is detected at a position coincident with the TeV source HESS J1857+026. The gamma-ray spectrum is well described by a simple power law with a spectral index of Gamma = 1.53 +/- 0.11(sub stat) +/- 0.55(sub syst) and an energy flux of G(0.1 C100 GeV) = (2.71 +/- 0.52(sub stat) +/- 1.51(sub syst) X 10(exp -11) ergs/ sq cm/s. This implies a gamma.ray efficiency of approx 5 %, assuming a distance of 9 kpc, the gamma-ray luminosity of L(sub gamma) (sub PWN) (0.1 C100 GeV) = (2.5 +/- 0.5(sub stat) +/- 1.5(sub syst)) X 10(exp 35)(d/(9kpc))(exp 2) ergs/s and E-dot = 4.6 X 10(exp 36) erg /s, in the range expected for pulsar wind nebulae. Detailed multi-wavelength modeling provides new constraints on its pulsar wind nebula nature.

  1. Deep Morphological and Spectral Study of the SNR RCW 86 with Fermi-LAT

    NASA Astrophysics Data System (ADS)

    Ajello, M.; Baldini, L.; Barbiellini, G.; Bastieri, D.; Bellazzini, R.; Bissaldi, E.; Bloom, E. D.; Bonino, R.; Bottacini, E.; Brandt, T. J.; Bregeon, J.; Bruel, P.; Buehler, R.; Caliandro, G. A.; Cameron, R. A.; Caragiulo, M.; Cavazzuti, E.; Charles, E.; Chekhtman, A.; Ciprini, S.; Cohen-Tanugi, J.; Condon, B.; Costanza, F.; Cutini, S.; D'Ammando, F.; de Palma, F.; Desiante, R.; Di Lalla, N.; Di Mauro, M.; Di Venere, L.; Drell, P. S.; Dubner, G.; Dumora, D.; Duvidovich, L.; Favuzzi, C.; Focke, W. B.; Fusco, P.; Gargano, F.; Gasparrini, D.; Giacani, E.; Giglietto, N.; Glanzman, T.; Green, D. A.; Grenier, I. A.; Guiriec, S.; Hays, E.; Hewitt, J. W.; Hill, A. B.; Horan, D.; Jogler, T.; Jóhannesson, G.; Jung-Richardt, I.; Kensei, S.; Kuss, M.; Larsson, S.; Latronico, L.; Lemoine-Goumard, M.; Li, J.; Li, L.; Longo, F.; Loparco, F.; Lovellette, M. N.; Lubrano, P.; Magill, J.; Maldera, S.; Manfreda, A.; Mayer, M.; Mazziotta, M. N.; McEnery, J. E.; Michelson, P. F.; Mitthumsiri, W.; Mizuno, T.; Monzani, M. E.; Morselli, A.; Moskalenko, I. V.; Negro, M.; Nuss, E.; Orienti, M.; Orlando, E.; Ormes, J. F.; Paneque, D.; Perkins, J. S.; Pesce-Rollins, M.; Piron, F.; Pivato, G.; Porter, T. A.; Rainò, S.; Rando, R.; Razzano, M.; Reimer, A.; Reimer, O.; Reposeur, T.; Schmid, J.; Schulz, A.; Sgrò, C.; Simone, D.; Siskind, E. J.; Spada, F.; Spandre, G.; Spinelli, P.; Thayer, J. B.; Tibaldo, L.; Torres, D. F.; Tosti, G.; Troja, E.; Uchiyama, Y.; Vianello, G.; Vink, J.; Wood, K. S.; Yassine, M.

    2016-03-01

    RCW 86 is a young supernova remnant (SNR) showing a shell-type structure at several wavelengths and is thought to be an efficient cosmic-ray (CR) accelerator. Earlier Fermi Large Area Telescope results reported the detection of γ-ray emission coincident with the position of RCW 86 but its origin (leptonic or hadronic) remained unclear due to the poor statistics. Thanks to 6.5 years of data acquired by the Fermi-LAT and the new event reconstruction Pass 8, we report the significant detection of spatially extended emission coming from RCW 86. The spectrum is described by a power-law function with a very hard photon index ({{Γ }}=1.42+/- {0.1}{{stat}}+/- {0.06}{{syst}}) in the 0.1-500 GeV range and an energy flux above 100 MeV of (2.91+/- {0.8}{{stat}}+/- {0.12}{{syst}}) × {10}-11 erg cm-2 s-1. Gathering all the available multiwavelength (MWL) data, we perform a broadband modeling of the nonthermal emission of RCW 86 to constrain parameters of the nearby medium and bring new hints about the origin of the γ-ray emission. For the whole SNR, the modeling favors a leptonic scenario in the framework of a two-zone model with an average magnetic field of 10.2 ± 0.7 μG and a limit on the maximum energy injected into protons of 2 × 1049 erg for a density of 1 cm-3. In addition, parameter values are derived for the north-east and south-west (SW) regions of RCW 86, providing the first indication of a higher magnetic field in the SW region.

  2. Hunting dark matter gamma-ray lines with the Fermi LAT

    SciTech Connect

    Vertongen, Gilles; Weniger, Christoph E-mail: weniger@mppmu.mpg.de

    2011-05-01

    Monochromatic photons could be produced in the annihilation or decay of dark matter particles. At high energies, the search for such line features in the cosmic gamma-ray spectrum is essentially background free because plausible astrophysical processes are not expected to produce such a signal. The observation of a gamma-ray line would hence be a 'smoking-gun' signature for dark matter, making the search for such signals particularly attractive. Among the different dark matter models predicting gamma-ray lines, the local supersymmetric extension of the standard model with small R-parity violation and gravitino LSP is of particular interest because it provides a framework where primordial nucleosynthesis, gravitino dark matter and thermal leptogenesis are naturally consistent. Using the two-years Fermi LAT data, we present a dedicated search for gamma-ray lines coming from dark matter annihilation or decay in the Galactic halo. Taking into account the full detector response, and using a binned profile likelihood method, we search for significant line features in the energy spectrum of the diffuse flux observed in different regions of the sky. No evidence for a line signal at the 5σ level is found for photon energies between 1 and 300 GeV, and conservative bounds on dark matter decay rates and annihilation cross sections are presented. Implications for gravitino dark matter in presence of small R-parity violation are discussed, as well as the impact of our results on the prospect for seeing long-lived neutralinos or staus at the LHC.

  3. Fermi-LAT constraints on the pulsar wind nebula nature of HESS J1857+026

    NASA Astrophysics Data System (ADS)

    Rousseau, R.; Grondin, M.-H.; Van Etten, A.; Lemoine-Goumard, M.; Bogdanov, S.; Hessels, J. W. T.; Kaspi, V. M.; Arzoumanian, Z.; Camilo, F.; Casandjian, J. M.; Espinoza, C. M.; Johnston, S.; Lyne, A. G.; Smith, D. A.; Stappers, B. W.; Caliandro, G. A.

    2012-08-01

    Context. Since its launch, the Fermi satellite has firmly identified 5 pulsar wind nebulae plus a large number of candidates, all powered by young and energetic pulsars. HESS J1857 + 026 is a spatially extended γ-ray source detected by H.E.S.S. and classified as a possible pulsar wind nebula candidate powered by PSR J1856 + 0245. Aims: We search for γ-ray pulsations from PSR J1856+0245 and explore the characteristics of its associated pulsar wind nebula. Methods: Using a rotational ephemeris obtained from the Lovell telescope at Jodrell Bank Observatory at 1.5 GHz, we phase-fold 36 months of γ-ray data acquired by the Large Area Telescope (LAT) aboard Fermi. We also perform a complete γ-ray spectral and morphological analysis. Results: No γ-ray pulsations were detected from PSR J1856+0245. However, significant emission is detected at a position coincident with the TeV source HESS J1857 + 026. The γ-ray spectrum is well described by a simple power-law with a spectral index of Γ = 1.53 ± 0.11stat ± 0.55syst and an energy flux of G(0.1-100 GeV) = (2.71 ± 0.52stat ± 1.51syst) × 10-11 erg cm-2 s-1. The γ-ray luminosity is LPWNγ (0.1-100 GeV)=(2.5 ± 0.5stat ± 1.5syst) × 1035 (d/9 kpc)2 erg s-1, assuming a distance of 9 kpc. This implies a γ-ray efficiency of ~5% for Ė = 4.6 × 1036 erg s-1, in the range expected for pulsar wind nebulae. Detailed multi-wavelength modeling provides new constraints on its pulsar wind nebula nature.

  4. Limits on Large Extra Dimensions Based on Observations of Neutron Stars with the Fermi-LAT

    NASA Technical Reports Server (NTRS)

    Ferrara, E. C.; Scargle, J. D.; Troja, E.

    2012-01-01

    We present limits for the compactification scale in the theory of Large Extra Dimensions (LED) proposed by Arkani-Hamed, Dimopoulos, and Dvali. We use 11 months of data from the Fermi Large Area Telescope (Fermi-LAT) to set gamma ray flux limits for 6 gamma-ray faint neutron stars (NS). To set limits on LED we use the model of Hannestad and Raffelt (HR) that calculates the Kaluza-Klein (KK) graviton production in supernova cores and the large fraction subsequently gravitationally bound around the resulting NS. The predicted decay of the bound KK gravitons to should contribute to the flux from NSs. Considering 2 to 7 extra dimensions of the same size in the context of the HR model, we use Monte Carlo techniques to calculate the expected differential flux of gamma-rays arising from these KK gravitons, including the effects of the age of the NS, graviton orbit, and absorption of gamma-rays in the magnetosphere of the NS. We compare our Monte Carlo-based differential flux to the experimental differential flux using maximum likelihood techniques to obtain our limits on LED. Our limits are more restrictive than past EGRET-based optimistic limits that do not include these important corrections. Additionally, our limits are more stringent than LHC based limits for 3 or fewer LED, and comparable for 4 LED. We conclude that if the effective Planck scale is around a TeV, then for 2 or 3 LED the compactification topology must be more complicated than a torus.

  5. Limits on Large Extra Dimensions Based on Observations of Neutron Stars with the Fermi-LAT

    SciTech Connect

    Ajello, M.; Baldini, L.; Barbiellini, G.; Bastieri, D.; Bechtol, K.; Bellazzini, R.; Berenji, B.; Bloom, E.D.; Bonamente, E.; Borgland, A.W.; Bregeon, J.; Brigida, M.; Bruel, P.; Buehler, R.; Buson, S.; Caliandro, G.A.; Cameron, R.A.; Caraveo, P.A.; Casandjian, J.M.; Cecchi, C.; Charles, E.; /more authors..

    2012-08-17

    We present limits for the compactification scale in the theory of Large Extra Dimensions (LED) proposed by Arkani-Hamed, Dimopoulos, and Dvali. We use 11 months of data from the Fermi Large Area Telescope (Fermi-LAT) to set gamma ray flux limits for 6 gamma-ray faint neutron stars (NS). To set limits on LED we use the model of Hannestad and Raffelt (HR) that calculates the Kaluza-Klein (KK) graviton production in supernova cores and the large fraction subsequently gravitationally bound around the resulting NS. The predicted decay of the bound KK gravitons to {gamma}{gamma} should contribute to the flux from NSs. Considering 2 to 7 extra dimensions of the same size in the context of the HR model, we use Monte Carlo techniques to calculate the expected differential flux of gamma-rays arising from these KK gravitons, including the effects of the age of the NS, graviton orbit, and absorption of gamma-rays in the magnetosphere of the NS. We compare our Monte Carlo-based differential flux to the experimental differential flux using maximum likelihood techniques to obtain our limits on LED. Our limits are more restrictive than past EGRET-based optimistic limits that do not include these important corrections. Additionally, our limits are more stringent than LHC based limits for 3 or fewer LED, and comparable for 4 LED. We conclude that if the effective Planck scale is around a TeV, then for 2 or 3 LED the compactification topology must be more complicated than a torus.

  6. Hunting dark matter gamma-ray lines with the Fermi LAT

    NASA Astrophysics Data System (ADS)

    Vertongen, Gilles; Weniger, Christoph

    2011-05-01

    Monochromatic photons could be produced in the annihilation or decay of dark matter particles. At high energies, the search for such line features in the cosmic gamma-ray spectrum is essentially background free because plausible astrophysical processes are not expected to produce such a signal. The observation of a gamma-ray line would hence be a `smoking-gun' signature for dark matter, making the search for such signals particularly attractive. Among the different dark matter models predicting gamma-ray lines, the local supersymmetric extension of the standard model with small R-parity violation and gravitino LSP is of particular interest because it provides a framework where primordial nucleosynthesis, gravitino dark matter and thermal leptogenesis are naturally consistent. Using the two-years Fermi LAT data, we present a dedicated search for gamma-ray lines coming from dark matter annihilation or decay in the Galactic halo. Taking into account the full detector response, and using a binned profile likelihood method, we search for significant line features in the energy spectrum of the diffuse flux observed in different regions of the sky. No evidence for a line signal at the 5σ level is found for photon energies between 1 and 300 GeV, and conservative bounds on dark matter decay rates and annihilation cross sections are presented. Implications for gravitino dark matter in presence of small R-parity violation are discussed, as well as the impact of our results on the prospect for seeing long-lived neutralinos or staus at the LHC.

  7. Comparison of counter-immunoelectrophoresis with other serological tests in the diagnosis of human brucellosis

    PubMed Central

    Díaz, R.; Maravi-Poma, E.; Rivero, A.

    1976-01-01

    Sera from 65 persons with clinical brucellosis were employed in a comparison of standard and rapid serological tests. The results obtained with the Rose Bengal test correlated very well with those of the standard tube agglutination test, whereas results with the rapid plate agglutination test and the Coombs (antiglobulin) test were inferior. Absorption of patients' sera with specific anti-human immunoglobulin sera showed that IgM was active in the Rose Bengal test but not in the Coombs test, whereas IgG and IgA were active in both tests. In addition to the A & M antigen, which plays the most important role in the agglutination, Rose Bengal, and Coombs tests, other antigenic fractions of Brucella were examined in precipitation tests. A protein antigen reacted with 94% of the sera in counter-immunoelectrophoresis. On the basis of the results with both groups of sera, the Rose Bengal test and counter-immunoelectrophoresis appear to be the most promising methods for diagnosing clinical brucellosis. The tests differ qualitatively since different Brucella antigens are employed. PMID:791532

  8. Oriented Cell Division in the C. elegans Embryo Is Coordinated by G-Protein Signaling Dependent on the Adhesion GPCR LAT-1

    PubMed Central

    Fiedler, Franziska; Sastradihardja, Tania; Binder, Claudia; Schnabel, Ralf; Kungel, Jana; Rothemund, Sven; Hennig, Christian; Schöneberg, Torsten; Prömel, Simone

    2015-01-01

    Orientation of spindles and cell division planes during development of many species ensures that correct cell-cell contacts are established, which is vital for proper tissue formation. This is a tightly regulated process involving a complex interplay of various signals. The molecular mechanisms underlying several of these pathways are still incompletely understood. Here, we identify the signaling cascade of the C. elegans latrophilin homolog LAT-1, an essential player in the coordination of anterior-posterior spindle orientation during the fourth round of embryonic cell division. We show that the receptor mediates a G protein-signaling pathway revealing that G-protein signaling in oriented cell division is not solely GPCR-independent. Genetic analyses showed that through the interaction with a Gs protein LAT-1 elevates intracellular cyclic AMP (cAMP) levels in the C. elegans embryo. Stimulation of this G-protein cascade in lat-1 null mutant nematodes is sufficient to orient spindles and cell division planes in the embryo in the correct direction. Finally, we demonstrate that LAT-1 is activated by an intramolecular agonist to trigger this cascade. Our data support a model in which a novel, GPCR-dependent G protein-signaling cascade mediated by LAT-1 controls alignment of cell division planes in an anterior-posterior direction via a metabotropic Gs-protein/adenylyl cyclase pathway by regulating intracellular cAMP levels. PMID:26505631

  9. Mutation of the phospholipase C-γ1–binding site of LAT affects both positive and negative thymocyte selection

    PubMed Central

    Sommers, Connie L.; Lee, Jan; Steiner, Kevin L.; Gurson, Jordan M.; DePersis, Corinne L.; El-Khoury, Dalal; Fuller, Claudette L.; Shores, Elizabeth W.; Love, Paul E.; Samelson, Lawrence E.

    2005-01-01

    Linker for activation of T cells (LAT) is a scaffolding adaptor protein that is critical for T cell development and function. A mutation of LAT (Y136F) that disrupts phospholipase C-γ1 activation and subsequent calcium influx causes a partial block in T cell development and leads to a severe lymphoproliferative disease in homozygous knock-in mice. One possible contribution to the fatal disease of LAT Y136F knock-in mice could be from autoreactive T cells generated in these mice because of altered thymocyte selection. To examine the impact of the LAT Y136F mutation on thymocyte positive and negative selection, we bred this mutation onto the HY T cell receptor (TCR) transgenic, recombination activating gene-2 knockout background. Female mice with this genotype showed a severe defect in positive selection, whereas male mice exhibited a phenotype resembling positive selection (i.e., development and survival of CD8hi HY TCR-specific T cells) instead of negative selection. These results support the hypothesis that in non-TCR transgenic, LAT Y136F knock-in mice, altered thymocyte selection leads to the survival and proliferation of autoreactive T cells that would otherwise be negatively selected in the thymus. PMID:15795236

  10. Oriented Cell Division in the C. elegans Embryo Is Coordinated by G-Protein Signaling Dependent on the Adhesion GPCR LAT-1.

    PubMed

    Müller, Antje; Winkler, Jana; Fiedler, Franziska; Sastradihardja, Tania; Binder, Claudia; Schnabel, Ralf; Kungel, Jana; Rothemund, Sven; Hennig, Christian; Schöneberg, Torsten; Prömel, Simone

    2015-10-01

    Orientation of spindles and cell division planes during development of many species ensures that correct cell-cell contacts are established, which is vital for proper tissue formation. This is a tightly regulated process involving a complex interplay of various signals. The molecular mechanisms underlying several of these pathways are still incompletely understood. Here, we identify the signaling cascade of the C. elegans latrophilin homolog LAT-1, an essential player in the coordination of anterior-posterior spindle orientation during the fourth round of embryonic cell division. We show that the receptor mediates a G protein-signaling pathway revealing that G-protein signaling in oriented cell division is not solely GPCR-independent. Genetic analyses showed that through the interaction with a Gs protein LAT-1 elevates intracellular cyclic AMP (cAMP) levels in the C. elegans embryo. Stimulation of this G-protein cascade in lat-1 null mutant nematodes is sufficient to orient spindles and cell division planes in the embryo in the correct direction. Finally, we demonstrate that LAT-1 is activated by an intramolecular agonist to trigger this cascade. Our data support a model in which a novel, GPCR-dependent G protein-signaling cascade mediated by LAT-1 controls alignment of cell division planes in an anterior-posterior direction via a metabotropic Gs-protein/adenylyl cyclase pathway by regulating intracellular cAMP levels.

  11. Fermi-LAT Discovery of Extended Gamma-Ray Emission in the Direction of Supernova Remnant W51C

    SciTech Connect

    Abdo, A.A.; Ackermann, M.; Ajello, M.; Baldini, L.; Ballet, J.; Barbiellini, G.; Baring, M.G.; Bastieri, D.; Baughman, B.M.; Bechtol, K.; Bellazzini, R.; Berenji, B.; Blandford, R.D.; Bloom, E.D.; Bonamente, E.; Borgland, A.W.; Bouvier, A.; Bregeon, J.; Brez, A.; Brigida, M.; Bruel, P.; /more authors..

    2012-03-30

    The discovery of bright gamma-ray emission coincident with supernova remnant (SNR) W51C is reported using the Large Area Telescope (LAT) onboard the Fermi Gamma-ray Space Telescope. W51C is a middle-aged remnant ({approx}10{sup 4} yr) with intense radio synchrotron emission in its shell and known to be interacting with a molecular cloud. The gamma-ray emission is spatially extended, broadly consistent with the radio and X-ray extent of SNR W51C. The energy spectrum in the 0.2-50 GeV band exhibits steepening toward high energies. The luminosity is greater than 1 x 10{sup 36} erg s{sup -1} given the distance constraint of D > 5.5 kpc, which makes this object one of the most luminous gamma-ray sources in our Galaxy. The observed gamma-rays can be explained reasonably by a combination of efficient acceleration of nuclear cosmic rays at supernova shocks and shock-cloud interactions. The decay of neutral p mesons produced in hadronic collisions provides a plausible explanation for the gamma-ray emission. The product of the average gas density and the total energy content of the accelerated protons amounts to {bar n}{sub H} W{sub p} {approx_equal} 5 x 10{sup 51} (D/6 kpc){sup 2} erg cm{sup -3}. Electron density constraints from the radio and X-ray bands render it difficult to explain the LAT signal as due to inverse Compton scattering. The Fermi LAT source coincident with SNR W51C sheds new light on the origin of Galactic cosmic rays.

  12. GAMMA-RAY FLARING ACTIVITY FROM THE GRAVITATIONALLY LENSED BLAZAR PKS 1830–211 OBSERVED BY Fermi LAT

    SciTech Connect

    Abdo, A. A.; Ackermann, M.; Buehler, R.; Ajello, M.; Allafort, A.; Bechtol, K.; Blandford, R. D.; Borgland, A. W.; Caliandro, G. A.; Cameron, R. A.; Amin, M. A.; Baldini, L.; Bellazzini, R.; Barbiellini, G.; Bastieri, D.; Buson, S.; Bonamente, E.; Bregeon, J.; Bulmash, D. E-mail: stefano.ciprini@asdc.asi.it E-mail: dammando@ira.inaf.it E-mail: sara.buson@pd.infn.it E-mail: dammando@ira.inaf.it; and others

    2015-02-01

    The Large Area Telescope (LAT) on board the Fermi Gamma-ray Space Telescope routinely detects the MeV-peaked flat-spectrum radio quasar PKS 1830–211 (z = 2.507). Its apparent isotropic γ-ray luminosity (E > 100 MeV), averaged over ∼3 years of observations and peaking on 2010 October 14/15 at 2.9 × 10{sup 50} erg s{sup –1}, makes it among the brightest high-redshift Fermi blazars. No published model with a single lens can account for all of the observed characteristics of this complex system. Based on radio observations, one expects time-delayed variability to follow about 25 days after a primary flare, with flux about a factor of 1.5 less. Two large γ-ray flares of PKS 1830–211 have been detected by the LAT in the considered period, and no substantial evidence for such a delayed activity was found. This allows us to place a lower limit of about 6 on the γ-ray flux ratio between the two lensed images. Swift XRT observations from a dedicated Target of Opportunity program indicate a hard spectrum with no significant correlation of X-ray flux with the γ-ray variability. The spectral energy distribution can be modeled with inverse Compton scattering of thermal photons from the dusty torus. The implications of the LAT data in terms of variability, the lack of evident delayed flare events, and different radio and γ-ray flux ratios are discussed. Microlensing effects, absorption, size and location of the emitting regions, the complex mass distribution of the system, an energy-dependent inner structure of the source, and flux suppression by the lens galaxy for one image path may be considered as hypotheses for understanding our results.

  13. Fermi-LAT detection of a GeV gamma-ray flare from the blazar PKS 0514-459

    NASA Astrophysics Data System (ADS)

    Ciprini, Stefano

    2016-01-01

    The Large Area Telescope (LAT), one of the two instruments on the Fermi Gamma-ray Space Telescope, has observed increasing gamma-ray flux from a source positionally consistent with the flat spectrum radio quasar PKS 0514-459 (also known as RX J0515.7-4556 and 3FGL J0515.3-4557), with radio counterpart position R.A.: 78.938767 deg, Dec.: -45.945369 deg (J2000.0, Costa & Loyola 1996, A & AS, 115, 75) and with redshift z=0.194 (Stickel, Kuehr, & Fried 1993, A & AS, 97, 483).

  14. Fermi LAT and GASP detections of a concurrent GeV and optical flare from the blazar OJ 287

    NASA Astrophysics Data System (ADS)

    Ciprini, S.; Gasparrini, D.; Reyes, L. C.; Tanaka, Y. T.; Tosti, G.; Villata, M.; Raiteri, C. M.; Takalo, L. O.

    2009-10-01

    The Large Area Telescope (LAT), one of the two instruments on the Fermi Gamma-ray Space Telescope discovered a rapid gamma-ray flare from a source positionally consistent with the optically bright BL Lac object OJ 287 (RA: 08h 54m 48.874s , Dec: +20d 06m 30.64s, J2000.0, Johnston et al. 1995, AJ, 110, 880, -- redshift z=0.306, Falomo, Scarpa, & Bersanelli 1994, ApJS, 93, 125; Sitko & Junkkarinen 1985, PASP, 97, 1158).

  15. Space Detectors for Gamma Rays (100 MeV-100 GeV): from Egret to Fermi LAT

    NASA Technical Reports Server (NTRS)

    Thompson, David J.

    2015-01-01

    The design of spaceborne high-energy (E is greater than 100 MeV) gamma-ray detectors depends on two principal factors: (1) the basic physics of detecting and measuring the properties of the gamma rays; and (2) the constraints of operating such a detector in space for an extended period. Improvements in technology have enabled major advances in detector performance, as illustrated by two successful instruments, EGRET on the Compton Gamma Ray Observatory and LAT on the Fermi Gamma-ray Space Telescope.

  16. Fermi-LAT detection of hard spectrum gamma-ray flare from FSRQ S4 1800+44

    NASA Astrophysics Data System (ADS)

    Gasparrini, D.; Buson, S.

    2016-03-01

    The Large Area Telescope (LAT), one of the two instruments on the Fermi Gamma-ray Space Telescope, has observed increasing gamma-ray flux and an unusually hard gamma-ray spectrum from a source positionally consistent with the flat spectrum radio quasar (FSRQ) S4 1800+44 (also known as 3FGL J1801.5+4403, Acero et al. 2015, ApJS, 218, 23) with radio counterpart coordinates (J2000.0), R.A. = 270.3846454 deg, Dec. = 44.0727500 deg (Johnston et al. 1995, AJ, 110, 880).

  17. Fermi LAT detection of increasing gamma-ray emission from the radio-loud NLSy1 PKS 1502+036

    NASA Astrophysics Data System (ADS)

    D'Ammando, Filippo; Ciprini, Stefano

    2015-12-01

    The Large Area Telescope (LAT), on board the Fermi Gamma-ray Space Telescope, has observed gamma-ray flaring activity from a source positionally consistent with the radio-loud narrow-line Seyfert 1 PKS 1502+036 (also known as 3FGL J1505.1+0326, Acero et al. 2015, ApJS, 218, 23), with radio coordinates (J2000.0), R.A.: 226.2769879 deg, Dec.: 3.4418922 deg (Fey et al. 2004, AJ, 127, 3587) at redshift z = 0.4078 (Hewett & Wild 2010, MNRAS, 405, 2302).

  18. Fermi-LAT detection of a GeV gamma-ray flare from the blazar PKS 1313-333

    NASA Astrophysics Data System (ADS)

    Ciprini, Stefano

    2016-01-01

    The Large Area Telescope (LAT), one of the two instruments on the Fermi Gamma-ray Space Telescope, has observed increasing gamma-ray flux from a source positionally consistent with the flat spectrum radio quasar PKS 1313-333 (also known as TXS 1313-333, OP -322, 2EG J1314-3430 and 3FGL J1316.0-3338), with radio counterpart position R.A.: 199.033275 deg, Dec.: -33.64977 deg, (J2000.0, Johnston et al. 1995, AJ, 110, 880) and with redshift z=1.210 (Jauncey et al. 1982, AJ, 87, 763).

  19. Fermi-LAT detection of a GeV gamma-ray flare from the BL Lac object OT 081

    NASA Astrophysics Data System (ADS)

    Becerra Gonzalez, J.; Thompson, D.; Fermi-LAT Collaboration

    2016-07-01

    The Large Area Telescope (LAT), one of the two instruments on the Fermi Gamma-ray Space Telescope, has observed increasing gamma-ray flux from a source positionally consistent with the BL Lac object OT 081 (also known as PKS 1749+096, 4C 09.57, 0FGL J1751.5+0935, 1FGL J1751.5+0937, 2FGL J1751.5+0938, 1FHL J1751.5+0938, 3FGL J1751.5+0939), with the radio counterpart position R.A.: 267.88674 deg, Dec.: 9.65020 deg (J2000.0, Lanyi et al. 2010, AJ, 139, 1695).

  20. Increase of glycocalyx and altered lectin agglutination profiles of Pasteurella haemolytica A1 after incubation in bovine subcutaneous tissue chambers in vivo or in ruminant serum in vitro.

    PubMed Central

    Brogden, K; Clarke, C

    1997-01-01

    Pasteurella haemolytica serotype A1 (bovine strain OK) was incubated for 2 and 6 h in bovine subcutaneous tissue chambers in vivo, and ovine strain 82-25 and bovine strain L011 were incubated in vitro for 2 h in heat-inactivated ovine or bovine serum from which gamma globulin had been depleted by protein G affinity chromatography to assess changes in morphology and lectin agglutination profiles (strains 82-25 and L101 only). Cells, removed from chambers after 2 h, were covered with an extensive, dense glycocalyx extending approximately 0.5 microm from the cell surface. In many cells, the glycocalyx was separated from the cell surface by a clear, electron-transparent area. Cells, removed at 6 h, were covered with a sparse glycocalyx of fine fibers 0.2 to 0.3 microm from the cell surface. Strains 82-25 and L101, incubated for 2 h in heat-inactivated ovine or bovine serum or in heat-inactivated ovine or bovine serum depleted of gamma globulin by protein G affinity chromatography, were also covered with a glycocalyx. The glycocalyx did not bind protein A-colloidal gold and therefore did not contain aggregates of accumulated antibody. Strains 82-25 and L101 were incubated individually for 2 h in 10 mM sodium phosphate buffer (pH 7.2) containing 0.14 M NaCl, 0.5 mM CaCl2, and 0.15 mM MgCl2 or with this buffer and either 25% heat-inactivated, gamma globulin-depleted ovine serum or 25% heat-inactivated, gamma globulin-depleted bovine serum. Agglutination profiles were then determined with 17 lectins in 10 mM HEPES-buffered saline (pH 8.4) with 0.1 mM CaCl2 and 0.08% sodium azide. Profiles did not vary with 10 of 17 lectins. However, profiles did vary with peanut agglutinin, Phaseolus vulgaris leucoagglutinin, Sophora japonica agglutinin, Maackia amurensis lectin II, Narcissus pseudonarcissus (daffodil) lectin, Griffonia simplicifolia lectin I, and Pisum sativum agglutinin. Altered profiles indicate a change in the bacterial cell surface, possibly by adsorption or

  1. VLBA observations of radio faint Fermi-LAT sources above 10 GeV

    NASA Astrophysics Data System (ADS)

    Lico, R.; Giroletti, M.; Orienti, M.; D'Ammando, F.

    2016-10-01

    Context. The first Fermi-LAT high-energy source catalog (1FHL), containing γ-ray sources detected above 10 GeV, is an ideal sample for characterizing the physical properties of the most extreme γ-ray sources. Aims: We investigate the pc scale properties of a subsample of radio faint 1FHL sources with the aim of confirming the proposed blazar associations by revealing a compact high brightness temperature radio core, and we propose new low-frequency counterparts for the unassociated γ-ray sources (UGS). Moreover, we increase the number of 1FHL sources with high-resolution observations to explore the possible connection between radio and γ rays at E> 10 GeV. Methods: We observed 84 1FHL sources, mostly blazars of high synchrotron peaked (HSP) type, in the northern sky with the Very Long Baseline Array (VLBA) at 5 GHz. These sources lack high-resolution radio observations and have at least one NRAO VLA sky survey counterpart within the 95% confidence radius. For those sources without a well-identified radio counterpart we exploit the VLBA multiple phase-center correlation capability to identify the possible low-frequency candidates. Results: For ~93% of the sources in our sample we reveal a compact high brightness temperature radio core, which supports their proposed blazar association. The vast majority of the detected sources are radio weak, with a median VLBI flux density value of 16.3 mJy. For the detected sources we obtain an average brightness temperature on the order of 2 × 1010 K. We find a compact component for 16 UGS, for which we propose a new low-frequency association. Conclusions: We find brightness temperature values that do not require high Doppler factors, and are in agreement with the expected values for the equipartition of energy between particles and magnetic field. We find strong indications for the blazar nature of all of the detected UGS, for which we propose new low-frequency associations. The characterization of the physical properties of

  2. Extending the Fermi-LAT Data Processing Pipeline to the Grid

    NASA Astrophysics Data System (ADS)

    Zimmer, S.; Arrabito, L.; Glanzman, T.; Johnson, T.; Lavalley, C.; Tsaregorodtsev, A.

    2012-12-01

    The Data Handling Pipeline (“Pipeline”) has been developed for the Fermi Gamma-Ray Space Telescope (Fermi) Large Area Telescope (LAT) which launched in June 2008. Since then it has been in use to completely automate the production of data quality monitoring quantities, reconstruction and routine analysis of all data received from the satellite and to deliver science products to the collaboration and the Fermi Science Support Center. Aside from the reconstruction of raw data from the satellite (Level 1), data reprocessing and various event-level analyses are also reasonably heavy loads on the pipeline and computing resources. These other loads, unlike Level 1, can run continuously for weeks or months at a time. In addition it receives heavy use in performing production Monte Carlo tasks. In daily use it receives a new data download every 3 hours and launches about 2000 jobs to process each download, typically completing the processing of the data before the next download arrives. The need for manual intervention has been reduced to less than 0.01% of submitted jobs. The Pipeline software is written almost entirely in Java and comprises several modules. The software comprises web-services that allow online monitoring and provides charts summarizing work flow aspects and performance information. The server supports communication with several batch systems such as LSF and BQS and recently also Sun Grid Engine and Condor. This is accomplished through dedicated job control services that for Fermi are running at SLAC and the other computing site involved in this large scale framework, the Lyon computing center of IN2P3. While being different in the logic of a task, we evaluate a separate interface to the Dirac system in order to communicate with EGI sites to utilize Grid resources, using dedicated Grid optimized systems rather than developing our own. More recently the Pipeline and its associated data catalog have been generalized for use by other experiments, and are

  3. Probing the cosmic-ray content of galaxy clusters by stacking Fermi-LAT count maps

    NASA Astrophysics Data System (ADS)

    Huber, B.; Tchernin, C.; Eckert, D.; Farnier, C.; Manalaysay, A.; Straumann, U.; Walter, R.

    2013-12-01

    Aims: Radio observations have shown that galaxy clusters are giant reservoirs of cosmic rays (CR). Although a gamma-ray signal from the cluster volume is expected to arise through interactions of CR protons with the ambient plasma, a confirming observation is still missing. Methods: We searched for a cumulative gamma-ray emission in the direction of galaxy clusters by analysing a collection of stacked Fermi-LAT count maps. Additionally, we investigated possible systematic differences in the emission between cool-core and non-cool-core cluster populations. Results: Making use of a sample of 53 clusters selected from the HIFLUGCS catalog, we do not detect a significant signal from the stacked sample. The upper limit on the average flux per cluster derived for the total stacked sample is at the level of a few 10-11 ph cm-2 s-1 at a 95% confidence level in the 1-300 GeV band, assuming power-law spectra with photon indices 2.0, 2.4, 2.8, and 3.2. Separate stacking of the cool-core and non-cool-core clusters in the sample lead to similar values of around 5 × 10-11 ph cm-2 s-1 and 2 × 10-11 ph cm-2 s-1, respectively. Conclusions: Under the assumption that decaying π0, produced in collisions between CRs and the ambient thermal gas, are responsible for gamma-ray emission, we set upper limits on the average CR content in galaxy clusters. For the entire cluster population, our upper limit on the gamma-ray flux translates into an upper limit on the average CR-to-thermal energy ratio of 4.6% for a photon index of 2.4, although it is possible for individual systems to exceed this limit. Our 95% upper limits are at the level expected from numerical simulations, which most likely suggests that the injection of CR at cosmological shocks is less efficient than previously assumed.

  4. The Fermi LAT/GBM detection of pulsed gamma-ray emission from PSR J1846-0258 up to 100 MeV

    NASA Astrophysics Data System (ADS)

    Kuiper, Lucien; Dekker, Ariane

    2016-05-01

    Applying phase coherent timing models, created using RXTE PCA and Swift XRT monitoring data of PSR J1846-0258 covering the period August 4, 2008 - March 11, 2016 (MJD 54682 - 57458), in timing analyses of Fermi LAT (PASS8) and Fermi GBM (TTE) data yielded for the first time the detection of pulsed gamma-ray emission from PSR J1846-0258 up to 100 MeV. Phase folding the barycentered Fermi LAT events (period MJD 56185-56338, i.e. Sept.

  5. Fermi-LAT, FACT, MAGIC and VERITAS detection of increasing gamma-ray activity from the high-energy peaked BL Lac object 1ES 1959+650

    NASA Astrophysics Data System (ADS)

    Buson, S.; Magill, J. D.; Dorner, D.; Biland, A.; Mirzoyan, R.; Mukherjee, R.

    2016-04-01

    The Fermi-LAT, FACT, MAGIC and VERITAS collaborations report the detection of enhanced gamma-ray activity from a source positionally consistent with the very-high-energy peaked BL Lac object 1ES 1959+650 (a.k.a 3FGL J2000.0+6509, in the 3rd LAT source catalog, 3FGL, Acero et al. 2015, ApJS 218, 23) with radio coordinates (J2000) R.A.: 299.999384 deg, Dec.: 65.148514 deg (Beasley et al. 2002, ApJS, 141, 13). This source has a redshift z=0.047 (Schachter et al. 1993, ApJ, 412, 541).

  6. Identification of an amphioxus intelectin homolog that preferably agglutinates gram-positive over gram-negative bacteria likely due to different binding capacity to LPS and PGN.

    PubMed

    Yan, Jie; Wang, Jianfeng; Zhao, Yaqi; Zhang, Jingye; Bai, Changcun; Zhang, Changqing; Zhang, Chao; Li, Kailin; Zhang, Haiqing; Du, Xiumin; Feng, Lijun

    2012-07-01

    Intelectin is a recently described galactofuranose-binding lectin that plays a role in innate immunity in vertebrates. Little is known about intelectin in invertebrates, including amphioxus, the transitional form between vertebrates and invertebrates. We cloned an amphioxus intelectin homolog, AmphiITLN-like, coding 302 amino acids with a conserved fibrinogen-related domain (FReD) in the N-terminus and an Intelectin domain in the C-terminus. In situ hybridization in adult amphioxus showed that AmphiITLN-like transcripts were highly expressed in the digestive tract and the skin. Quantitative real-time PCR revealed that AmphiITLN-like is significantly up-regulated in response to Staphylococcus aureus challenge, but only modestly to Escherichia coli. In addition, recombinant AmphiITLN-like expressed in E. coli agglutinates Gram-negative and Gram-positive bacteria to different degrees in a calcium dependent manner. Recombinant AmphiITLN-like could bind lipopolysaccharide (LPS) and peptidoglycan (PGN), the major cell wall components of Gram-negative and Gram-positive bacteria, respectively, with a higher affinity to PGN. Our work identified and characterized for the first time an amphioxus intelectin homolog, and provided insight into the evolution and function of the intelectin family.

  7. Recombinant jacalin-like plant lectins are produced at high levels in Nicotiana benthamiana and retain agglutination activity and sugar specificity.

    PubMed

    Fernandez-del-Carmen, Asun; Juárez, Paloma; Presa, Silvia; Granell, Antonio; Orzáez, Diego

    2013-02-20

    The plant kingdom is an underexplored source of valuable proteins which, like plant lectins, display unique interacting specificities. Furthermore, plant protein diversity remains under-exploited due to the low availability and heterogeneity of native sources. All these hurdles could be overcome with recombinant production. A narrow phylogenetic gap between the native source and the recombinant platform is likely to facilitate proper protein processing and stability; therefore, the plant cell chassis should be specially suited for the recombinant production of many plant native proteins. This is illustrated herein with the recombinant production of two representatives of the plant jacalin-related lectin (JRLs) protein family in Nicotiana benthamiana using state-of-the-art magnICON technology. Mannose-specific Banlec JRL was produced at very high levels in leaves, reaching 1.0mg of purified protein per gram of fresh weight and showing strong agglutination activity. Galactose-specific jacalin JRL, with its complicated processing requirements, was also successfully produced in N. benthamiana at levels of 0.25 mg of purified protein per gram of fresh weight. Recombinant Jacalin (rJacalin) proved efficient in the purification of human IgA1, and was able to discriminate between plant-made and native IgA1 due to their differential glycosylation status. Together, these results show that the plant cell factory should be considered a primary option in the recombinant production of valuable plant proteins.

  8. Fermi-LAT γ-ray anisotropy and intensity explained by unresolved radio-loud active galactic nuclei

    SciTech Connect

    Mauro, Mattia Di; Cuoco, Alessandro; Donato, Fiorenza; Siegal-Gaskins, Jennifer M. E-mail: alessandro.cuoco@to.infn.it E-mail: jsg@tapir.caltech.edu

    2014-11-01

    Radio-loud active galactic nuclei (AGN) are expected to contribute substantially to both the intensity and anisotropy of the isotropic γ-ray background (IGRB). In turn, the measured properties of the IGRB can be used to constrain the characteristics of proposed contributing source classes. We consider individual subclasses of radio-loud AGN, including low-, intermediate-, and high-synchrotron-peaked BL Lacertae objects, flat-spectrum radio quasars, and misaligned AGN. Using updated models of the γ-ray luminosity functions of these populations, we evaluate the energy-dependent contribution of each source class to the intensity and anisotropy of the IGRB. We find that collectively radio-loud AGN can account for the entirety of the IGRB intensity and anisotropy as measured by the Fermi Large Area Telescope (LAT). Misaligned AGN provide the bulk of the measured intensity but a negligible contribution to the anisotropy, while high-synchrotron-peaked BL Lacertae objects provide the dominant contribution to the anisotropy. In anticipation of upcoming measurements with the Fermi-LAT and the forthcoming Cherenkov Telescope Array, we predict the anisotropy in the broader energy range that will be accessible to future observations.

  9. A Statistical Approach to Recognizing Source Classes for Unassociated Sources in the First FERMI-LAT Catalog

    NASA Technical Reports Server (NTRS)

    Ackermann, M.; Ajello, M.; Allafort, A.; Antolini, E.; Baldini, L.; Ballet, J.; Barbiellini, G.; Bastieri, D.; Bellazzini, R.; Berenji, B.; Blandford, R. D.; Bloom, E. D.; Bonamente, E.; Borgland, A. W.; Bouvier, A.; Brandt, T. J.; Celik, O.; DeCesar, M. E.; Ferrara, E. C.; Gehrels, N.; Harding, A.K.; Hays, E.; McEnery, J. E.; Thompson, D. J.; Troja, E.

    2012-01-01

    The Fermi Large Area Telescope (LAT) First Source Catalog (1FGL) provided spatial, spectral, and temporal properties for a large number of gamma -ray sources using a uniform analysis method. After correlating with the mostcomplete catalogs of source types known to emit gamma rays, 630 of these sources are "unassociated" (i.e., have no obvious counterparts at other wavelengths). Here, we employ two statistical analyses of the primary gamma-ray characteristics for these unassociated sources in an effort to correlate their gamma-ray properties with the active galactic nucleus (AGN) and pulsar populations in 1FGL. Based on the correlation results, we classify 221 AGN-like and 134 pulsar-like sources in the 1FGL unassociated sources. The results of these source "classifications" appear to match the expected source distributions, especially at high Galactic latitudes. While useful for planning future multiwavelength follow-up observations, these analyses use limited inputs, and their predictions should not be considered equivalent to "probable source classes" for these sources. We discuss multiwavelength results and catalog cross-correlations to date, and provide new source associations for 229 Fermi-LAT sources that had no association listed in the 1FGL catalog. By validating the source classifications against these new associations, we find that the new association matches the predicted source class in approximately 80% of the sources.

  10. Dark Matter implications of the Fermi-LAT measurement of anisotropies in the diffuse gamma-ray background: Status report

    NASA Astrophysics Data System (ADS)

    Fornasa, Mattia; Zavala, Jesus; Sánchez-Conde, Miguel A.; Prada, Francisco; Vogelsberger, Mark

    2012-11-01

    For the first time, the Fermi-LAT measured the angular power spectrum (APS) of anisotropies in the diffuse gamma-ray background. The data is found to be broadly compatible with a model with contributions from the point sources in the 1-yr catalog, the galactic diffuse background, and the extragalactic isotropic emission; however, deviations are present at both large and small angular scales. In this study, we complement the model with a contribution from Dark Matter (DM) whose distribution is modeled exploiting the results of the most recent N-body simulations, considering the contribution of extragalactic halos and subhalos (from Millennium-II) and of galactic substructures (from Aquarius). With the use of the Fermi Science Tools, these simulations serve as templates to produce mock gamma-ray count maps for DM gamma-ray emission, both in the case of an annihilating and a decaying DM candidate. The APS will then be computed and compared with the Fermi-LAT results to derive constraints on the DM particle physics properties. The possible systematic due to an imperfect model of the galactic foreground is also studied and taken into account properly. The present paper reports on the status of the project.

  11. Fermi-LAT Detection of Gravitational Lens Delayed Gamma-Ray Flares from Blazar B0218+357

    NASA Technical Reports Server (NTRS)

    Cheung, C. C.; Larsson, S.; Scargle, J. D.; Amin, M. A.; Blandford, R. D.; Bulmash, D.; Chiang, J.; Ciprini, S.; Corbet, R. D. H.; Falco, E. E.; Marshall, P. J.; Wood, D. L.; Ajello, M.; Bastieri, D.; Chekhtman, A.; D'Ammando, F.; Giroletti, M.; Grove, J. E.; Lott, B.; Ohja, R.; Orienti, M.; Perkins, J. S.; Razzano, M.; Smith, A. W.; Thompson, D. J.; Wood, K. S.

    2014-01-01

    Using data from the Fermi Large Area Telescope (LAT), we report the first clear gamma-ray measurement of a delay between flares from the gravitationally lensed images of a blazar. The delay was detected in B0218+357, a known double-image lensed system, during a period of enhanced gamma-ray activity with peak fluxes consistently observed to reach greater than 20-50 times its previous average flux. An auto-correlation function analysis identified a delay in the gamma-ray data of 11.46 plus or minus 0.16 days (1 sigma) that is approximately 1 day greater than previous radio measurements. Considering that it is beyond the capabilities of the LAT to spatially resolve the two images, we nevertheless decomposed individual sequences of superposing gamma-ray flares/delayed emissions. In three such approximately 8-10 day-long sequences within an approximately 4-month span, considering confusion due to overlapping flaring emission and flux measurement uncertainties, we found flux ratios consistent with approximately 1, thus systematically smaller than those from radio observations. During the first, best-defined flare, the delayed emission was detailed with a Fermi pointing, and we observed flux doubling timescales of approximately 3-6 hours implying as well extremely compact gamma-ray emitting regions.

  12. Extending Fermi-LAT and H.E.S.S. limits on gamma-ray lines from dark matter annihilation

    NASA Astrophysics Data System (ADS)

    Profumo, Stefano; Queiroz, Farinaldo S.; Yaguna, Carlos E.

    2016-10-01

    Gamma-ray lines from dark matter annihilation (χχ → γX, where X = γ, h, Z) are always accompanied, at lower energies, by a continuum gamma-ray spectrum stemming both from radiative corrections (X = γ) and from the decay debris of the second particle possibly present in the final state (X = h, Z). This model-independent gamma-ray emission can be exploited to derive novel limits on gamma-ray lines that do not rely on the line feature. Although such limits are not expected to be as stringent as those based on the line feature, they can be used to probe the existence of gamma-ray lines for dark matter masses beyond the largest energies accessible to current telescopes. Here, we use continuous gamma-ray searches from Fermi-LAT observations of Milky Way dwarf spheroidal galaxies and from H.E.S.S. observations of the Galactic halo to extend the limits on the annihilation cross-sections into monochromatic photons to dark matter masses well beyond 500 GeV (Fermi-LAT) and 20 TeV (H.E.S.S.). In this large-mass regime, our results provide the first constraints on gamma-ray lines from dark matter annihilation.

  13. First Fermi LAT detection of a strong GeV gamma-ray flare from blazar PKS 0403-13

    NASA Astrophysics Data System (ADS)

    Ciprini, Stefano

    2016-07-01

    The Large Area Telescope (LAT), one of the two instruments on the Fermi Gamma-ray Space Telescope, has observed increasing gamma-ray flux from a source positionally consistent with the flat spectrum radio quasar PKS 0403-13 (also known as TXS 0403-132, OF -105, RX J0405.5-1308, and 3FGL J0405.5-1307), with radio counterpart position R.A.: 61.391680 deg, Dec.: -13.137136 deg (J2000.0, Fey et al. 2004, AJ, 127, 3587) and with redshift z=0.5706+/-0.0001 (Marziani et al. 1996, ApJS, 104, 37). Preliminary analysis indicates that on 2016 July 11, PKS 0403-13 was in a high state with a daily averaged gamma-ray flux (E > 100 MeV) of (1.6+/-0.3) X 10^-6 photons cm^-2 s^-1 (statistical uncertainty only), about 140 times greater than its four-year average flux reported in the third Fermi-LAT source catalog (3FGL, Acero et al. 2015, ApJS, 218, 23). The corresponding daily averaged spectral photon index (E > 100 MeV) of 2.3+/-0.2 (statistical uncertainty only) is compatible with the 3FGL catalog value of 2.35+/-0.11.

  14. Fermi-LAT detection of a GeV gamma-ray flare from the blazar PKS 2023-07

    NASA Astrophysics Data System (ADS)

    Ciprini, Stefano; Fermi Large Area Telescope Collaboration

    2016-04-01

    The Large Area Telescope (LAT), one of the two instruments on the Fermi Gamma-ray Space Telescope, has observed increasing gamma-ray flux from a source positionally consistent with the flat spectrum radio quasar PKS 2023-07 (also known as NRAO 629, TXS 2022-077, 3EG J2025-0744, 1AGLR J2027-0747 and 3FGL J2025.6-0736), with radio counterpart position R.A.: 306.419418 deg, Dec.: -7.597969 deg (J2000.0, Beasley et al. 2002, ApJS, 141, 13) and with redshift z=1.388 (Drinkwater et al. 1997, MNRAS, 284, 85). Preliminary analysis indicates that on 2016 April 9, PKS 2023-07 was in a high state with a daily averaged gamma-ray flux (E > 100 MeV) of (2.0+/-0.3) X 10^-6 photons cm^-2 s^-1 (statistical uncertainty only), about 16 times greater than its four-year average flux reported in the third Fermi-LAT source catalog (3FGL, Acero et al. 2015, ApJS, 218, 23). The corresponding daily averaged spectral photon index (E > 100 MeV) of 2.4+/-0.2 (statistical uncertainty only) is compatible with the 3FGL catalog value of 2.18+/-0.03.

  15. Chandra X-Ray Observations of the Two Brightest Unidentified High Galactic Latitude Fermi-LAT Gamma-Ray Sources

    NASA Technical Reports Server (NTRS)

    Cheung, C. C.; Donato, D.; Gehrels, N.; Sokolovsky, K. V.; Giroletti, M.

    2012-01-01

    We present Chandra ACIS-I X-ray observations of 0FGL J1311.9-3419 and 0FGL J1653.4-0200, the two brightest high Galactic latitude (absolute value (beta) >10 deg) gamma-ray sources from the three-month Fermi Large Area Telescope (LAT) bright source list that are still unidentified. Both were also detected previously by EGRET, and despite dedicated multi-wavelength follow-up, they are still not associated with established classes of gamma-ray emitters like pulsars or radio-loud active galactic nuclei. X-ray sources found in the ACIS-I fields of view are cataloged, and their basic properties are determined. These are discussed as candidate counterparts to 0FGL J1311.9-3419 and 0FGL J1653.4-0200, with particular emphasis on the brightest of the 9 and 13 Chandra sources detected within the respective Fermi-LAT 95% confidence regions. Further follow-up studies, including optical photometric and spectroscopic observations, are necessary to identify these X-ray candidate counterparts in order to ultimately reveal the nature of these enigmatic gamma-ray objects.

  16. OP12BORON NEUTRON CAPTURE THERAPY (BNCT): OPTIMISATION OF BORON UPTAKE AND PATIENT STRATIFICATION BY LAT1 IMPROVES BIOLOGICAL TARGETING WITH REDUCED RADIATION TIME, AND INCREASED CHANCE OF TUMOUR CONTROL

    PubMed Central

    Cruickshank, G.; Detta, A.; Ngoga, D.; Lockyer, N.; Pheonix, B.; Ghani, Z.; Green, S.

    2014-01-01

    INTRODUCTION: The interaction between an epithermal neutron beam, now deliverable with LINAC technology, and tumour cell accumulated Boron from borono-phenylalanine (BPA), releases an intracellular alpha particle and Li ion causing irrecoverable double strand DNA breaks, insensitive to hypoxia and cell cycle state. Augmented uptake of BPA in GBM cells due to LAT1 upregulation allows targeting of tumour cells, but optimisation of BPA delivery, and neutron exposure time, need clarification before a Phase I trial. METHOD: A pharmacokinetic (Pk)study of newly formulated BPA delivered by iv or close arterial infusion with preinfusion barrier opening, has been carried out in 10 new GBM patients. Plasma, ECF microdialysis, LAT1 activity, Tumour and brain around tumour (BAT) boron10 concentrations of have been used to model the optimum period for neutron beam therapy. RESULTS: 75% of GBM cells are LAT 1 positive, many more than the proliferative index PCNA. Pk studies indicate a three compartment model of BPA cell uptake rate limited by LAT1 exchange kinetics plateauing at four hours. LAT 1 density determines cell Boron dose. LAT1 uptake activity varies between core tumour cells and BAT tumour cells. LAT1 expression maybe particularly elevated in patients with unmethylated MGMT promoter. CONCLUSION: Patients with >50% LAT1 expression are likely to benefit from BNCT with non-LAT1 cells best treated with reduced fraction RT. The BPA uptake pattern favours BAT region tumour cells: those left after surgery regardless of -oxic or cell cycle status. BNCT offers a way of RT dose escalation to discontiguous GBM cells avoiding normal brain, exploits the biology of LAT1 and may offer benefit to patients unresponsive to Temozolomide.

  17. H-deficient Bombay and para-Bombay red blood cells are most strongly agglutinated by the galactophilic lectins of Aplysia and Pseudomonas aeruginosa that detect I and P1 antigens.

    PubMed

    Gilboa-Garber, N; Sudakevitz, D; Levene, C; Rahimi-Levene, N; Yahalom, V

    2006-01-01

    The galactophilic lectins Aplysia gonad lectin (AGL) and Pseudomonas aeruginosa lectin (PA-IL), which detect human I and P1 RBC antigens, were examined for hemagglutination of H+ (group O and B) and H-deficient (Bombay and para-Bombay phenotype) RBCs. The results were compared with those obtained using two other galactophilic lectins, Maclura pomifera lectin (MPL) and Arachis hypogaea (peanut) agglutinin (PNA), which share T-antigen affinity, and two fucose-binding H-specific lectins, Ulex europaeus (UEA-I) and Pseudomonas aeruginosa lectin (PA-IIL), as well as with those achieved with anti-I serum. The results revealed that, in contrast to UEA-I and PA-IIL, which preferentially agglutinated H+ RBCs, and to MPL and PNA, which similarly agglutinated all examined RBCs, AGL, PA-IL, and the anti-I serum agglutinated the H-deficient RBCs more strongly than did the H+ RBCs. These findings could be attributed to increased levels of I and P1 antigens on those RBCs resulting from the use of the free common H-type 2 precursor for their synthesis. Since both PA-IL and PA-IIL are regarded as potential pathogen adhesins, it would be interesting to statistically compare the sensitivities of individuals of H+ and H-deficient RBC populations to P. aeruginosa infections.

  18. Fermi/LAT Observations of Swift/BAT Seyfert Galaxies: On the Contribution of Radio-Quiet Active Galactic Nuclei to the Extragalactic gamma-Ray Background

    NASA Technical Reports Server (NTRS)

    Teng, Stacy H.; Mushotzky, Richard F.; Sambruna, Rita M.; Davis, David S.; Reynolds, Christopher S.

    2011-01-01

    We present the analysis of 2.1 years of Fermi Large Area Telescope (LAT) data on 491 Seyfert galaxies detected by the Swift Burst Alert Telescope (BAT) survey. Only the two nearest objects, NGC 1068 and NGC 4945, which were identified in the Fermi first year catalog, are detected. Using Swift/BAT and radio 20 cm fluxes, we define a new radio-loudness parameter R(sub X,BAT) where radio-loud objects have logR(sub X,BAT) > -4.7. Based on this parameter, only radio-loud sources are detected by Fermi/LAT. An upper limit to the flux of the undetected sources is derived to be approx.2x10(exp -11) photons/sq cm/s, approximately seven times lower than the observed flux of NGC 1068. Assuming a median redshift of 0.031, this implies an upper limit to the gamma-ray (1-100 GeV) luminosity of < approx.3x10(exp 41) erg/s. In addition, we identified 120 new Fermi/LAT sources near the Swift/BAT Seyfert galaxies with significant Fermi/LAT detections. A majority of these objects do not have Swift/BAT counterparts, but their possible optical counterparts include blazars, flat-spectrum radio quasars, and quasars.

  19. 50 CFR Table 2 (south) to Part 660... - 2010 Trip Limits for Limited Entry Fixed Gear South of 40°10′ N. Lat.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... Gear South of 40°10â² N. Lat. 2 Table 2 (South) to Part 660, Subpart E Wildlife and Fisheries FISHERY CONSERVATION AND MANAGEMENT, NATIONAL OCEANIC AND ATMOSPHERIC ADMINISTRATION, DEPARTMENT OF COMMERCE (CONTINUED) FISHERIES OFF WEST COAST STATES Pt. 660, Subpt. E, Table 2 Table 2 (South) to Part 660, Subpart E—2010...

  20. 50 CFR Table 2 (north) to Part 660... - 2010 Trip Limits for Limited Entry Fixed Gear North of 40°10′ N. Lat.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... Gear North of 40°10â² N. Lat. 2 Table 2 (North) to Part 660, Subpart E Wildlife and Fisheries FISHERY CONSERVATION AND MANAGEMENT, NATIONAL OCEANIC AND ATMOSPHERIC ADMINISTRATION, DEPARTMENT OF COMMERCE (CONTINUED) FISHERIES OFF WEST COAST STATES Pt. 660, Subpt. E, Table 2 Table 2 (North) to Part 660, Subpart E—2010...