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Sample records for acrosin amidase activity

  1. Acrosin activity is a good predictor of boar sperm freezability.

    PubMed

    Pinart, Elisabeth; Yeste, Marc; Bonet, Sergi

    2015-06-01

    The main aim of this study was to determine whether acrosin activity could predict boar sperm freezability. For this purpose, we characterized the changes in sperm quality and acrosin activity throughout the cryopreservation procedure of sperm samples from 30 Pietrain boars by analyzing four critical steps: step 1 (extended sperm at 15 °C), step 2 (cooled sperm at 5 °C), step 3 (30 minutes postthaw), and step 4 (240 minutes postthaw). Freezability ejaculate groups were set on the basis of sperm motility and membrane integrity after freeze-thawing. Results obtained highlighted the low predictive value in terms of freezability of sperm motility and kinematics and sperm membrane integrity, as no differences between good and poor freezability ejaculates were seen before cryopreservation. Significant differences (P < 0.05) between ejaculate groups were observed in the cooling step at 5 °C for sperm kinetic parameters, and after thawing for sperm motility and membrane integrity. In contrast, acrosin activity appeared as an indicator of boar sperm freezability because the differences (P < 0.05) between good and poor freezability ejaculates manifested yet in extended samples at 15 °C. On the other hand, we also found that variations in sperm kinematics, membrane lipid disorder, intracellular calcium content, acrosome integrity, and acrosin activity throughout the cryopreservation procedure were indicative of a significant damage in spermatozoa during the cooling step in both ejaculate groups. In conclusion, the main finding of our study is that acrosin activity can be used as a reliable predictor of boar sperm freezability because it differs significantly between good and poor freezability ejaculates yet before freeze-thawing procedures took place, i.e., in the refrigeration step at 15 °C.

  2. Determination of activable proacrosin/acrosin in bovine sperm using an irreversible isocoumarin serine protease inhibitor.

    PubMed

    Palencia, D D; Garner, D L; Hudig, D; Holcombe, D W; Burner, C A; Redelman, D; Fernandez, G C; Abuelyaman, A S; Kam, C M; Powers, J C

    1996-09-01

    The activable proacrosin/acrosin levels in bovine sperm were examined using fluorescent staining and flow cytometry. The proportion of sperm with active acrosin were determined using the biotinylated isocoumarin serine protease inhibitor, Bi-Aca-Aca-OMe-IC (BIC). The presence of bound inhibitor on sperm was then determined by secondary labeling with avidin fluorescein conjugate. The proportion of sperm with activable proacrosin/acrosin was assessed by using detergent treatment to expose the active acrosin in intact sperm. The difference between untreated and detergent-treated aliquots was used to estimate the proportion of sperm with activable proacrosin/acrosin. In the 24-h stored samples from six bulls, the mean proportion of sperm with activable proacrosin/acrosin was 78.8 +/- 2.8%, whereas the mean proportion with exposed acrosin after cryopreservation of these samples was 55.8 +/- 4.1%. Significant differences (p < 0.05) were found among bulls in the proportion of sperm with activable proacrosin/acrosin both before and after cryopreservation. Activable proacrosin/acrosin levels in samples of cryopreserved sperm from five bulls were not correlated with fertility. These results do indicate, however, that the irreversible isocoumarin serine protease inhibitor BIC can be used to determine the proportion of sperm cells that retain activable proacrosin/acrosin after cryopreservation and thawing.

  3. Characterization of proacrosin/acrosin system after liquid storage and cryopreservation of turkey semen (Meleagris gallopavo).

    PubMed

    Słowińska, M; Liszewska, E; Dietrich, G J; Ciereszko, A

    2012-09-15

    This study was designed to identify the effect of liquid storage at 4 °C for 48 h and cryopreservation on the proacrosin/acrosin system of turkey spermatozoa. Anti-acrosin I antibodies were produced and used to demonstrate Western blot analysis profile of the proacrosin/acrosin system of sperm and seminal plasma and possible changes in the proacrosin/acrosin system of turkey sperm stored for 2.5, 24, and 48 h or cryopreserved. At the same time acrosin-like activity was examined by the measurement of amidase activity of sperm extracts, sperm suspension, and seminal plasma of turkey semen. A computer-assisted sperm analysis system was used to monitor the sperm motility characteristics of turkey sperm stored for 48 h or cryopreserved. Different profiles of the sperm proacrosin/acrosin system were observed regarding the presence or absence of inhibitors (p-nitrophenyl-p'-guanidine benzoate [NPGB] and Kazal family inhibitor) during the extraction process. When NPGB was present three main bands were observed with the molecular weight ranging from 66 to 35 kDa. Bands corresponding to acrosin I and II were not observed. In sperm extract without NPGB, three or four bands were observed with the molecular weight ranging from 41 to 30 kDa. The bands corresponding to acrosin I and II were observed. During liquid storage a decrease in sperm motility and an increase in sperm-extracted amidase activity were observed. After 24 and 48 h of storage, extracted amidase activity was higher than at 2.5 h by 24% and 31%, respectively. However, no changes in the Western blot analysis profiles of sperm extract and seminal plasma were visible during liquid storage. After cryopreservation a decrease in sperm motility and all sperm motility parameters were observed. In contrast to liquid storage, cryopreservation did not increase extracted amidase activity. However, changes in Western blot analysis profiles were visible in sperm extract and seminal plasma after cryopreservation. After

  4. The circadian Clock gene regulates acrosin activity of sperm through serine protease inhibitor A3K

    PubMed Central

    Cheng, Shuting; Liang, Xin; Wang, Yuhui; Jiang, Zhou; Liu, Yanyou; Hou, Wang; Li, Shiping; Zhang, Jing

    2015-01-01

    Our previous study found that CLOCK knockdown in the testes of male mice led to a reduced fertility, which might be associated with the lower acrosin activity. In this present study, we examined the differential expression in proteins of CLOCK knockdown sperm. Clock gene expression was knocked down in cells to confirm those differentially expressions and serine protease inhibitor SERPINA3K was identified as a potential target. The up-regulated SERPINA3K revealed an inverse relationship with Clock knockdown. Direct treatment of normal sperm with recombinant SERPINA3K protein inhibited the acrosin activity and reduced in vitro fertilization rate. The luciferase reporter gene assay showed that the down-regulated of Clock gene could activate the Serpina3k promoter, but this activation was not affected by the mutation of E-box core sequence. Co-IP demonstrated a natural interaction between SERPIAN3K and RORs (α and β). Taken together, these results demonstrated that SERPINA3K is involved in the Clock gene-mediated male fertility by regulating acrosin activity and provide the first evidence that SERPINA3K could be regulated by Clock gene via retinoic acid-related orphan receptor response elements. PMID:26264441

  5. Acrosin activity in turkey spermatozoa: assay by clinical method and effect of zinc and benzamidine on the activity.

    PubMed

    Glogowski, J; Jankowski, J; Faruga, A; Ottobre, J S; Ciereszko, A

    2001-09-15

    We optimized a clinical assay developed for measuring total acrosin activity for mammalian and fish semen for use in turkey spermatozoa. The main modifications included dilution of semen to a final concentration of 25 to 1000 x 10(3) spermatozoa, an increase of Triton X-100 concentration to 0.05% and 1 hr preincubation without substrate, Acrosin activity in turkey spermatozoa was much higher than in human spermatozoa (about 100-times) but similar to that of boar sperm. To optimize this assay for turkey spermatozoa, it was necessary to use higher Triton X-100 concentrations in the reaction mixture. There was a better catalytic efficiency at higher temperatures and a special requirement for a preincubation period for proacrosin activation. We observed high inhibition of acrosin activity by zinc added during preincubation (90% at 0.01 mM of zinc chloride). Benzamidine also inhibited turkey acrosin, and the extent of inhibition was similar for the incubation or preincubation period. When zinc ions were added during incubation, this inhibition was lower (24%). The results suggest that zinc influences proacrosin activation of turkey spermatozoa. This influence may be important for successful long-term storage of spermatozoa in the hen's oviduct.

  6. Amidase activity in soils. IV. Effects of trace elements and pesticides

    SciTech Connect

    Frankenberger, W.T., Jr.; Tabatabai, M.A.

    1981-11-01

    Amidase was recently detected in soils, and this study was carried out to assess the effects of 21 trace elements, 12 herbicides, 2 fungicides, and 2 insecticides on the activity of this enzyme. Results showed that most of the trace elements and pesticides studied inhibited amidase activity in soils. The degree of inhibition varied among the soils used. When the trace elements were compared by using 5 ..mu..mol/g of soil, the average inhibition of amidase in three soils showed that Ag(I), Hg(I), As(III), and Se(IV) were the most effective inhibitors, but only Ag(I) and As(III) showed average inhibition > 50%. The least effective inhibitors (average inhibition < 3%) included Cu(I), Ba(II), Cu(II), Fe(II), Ni(II), Al(III), Fe(III), Ti(IV), V(IV), As(V), Mo(VI), and W(VI). Other elements that inhibited amidase activity in soils were Cd(II), Co(II), Mn(II), Pb(II), Sn(II), Zn(II), B(III), and Cr(III). Enzyme kinetic studies showed that As(III) was a competitive inhibitor of amidase, whereas Ag(I), Hg(II), and Se(IV) were noncompetitive inhibitors. When the pesticides studied were compared by using 10 ..mu..g of active ingredient per gram of soil, the average inhibition of amidase in three soils ranged from 2% with dinitroamine, EPTC plus R-25788, and captan to 10% with butylate. Other pesticides that inhibited amidase activity in soils were atrazine, naptalam, chloramben, dicamba, cyanazine, 2,4-D, alachlor, paraquat, trifluralin, maneb, diazinon, and malathion. The inhibition of amidase by diazinon, alachlor, and butylate followed noncompetitive kinetics.

  7. Fragments of pro-peptide activate mature penicillin amidase of Alcaligenes faecalis.

    PubMed

    Kasche, Volker; Galunsky, Boris; Ignatova, Zoya

    2003-12-01

    Penicillin amidase from Alcaligenes faecalis is a recently identified N-terminal nucleophile hydrolase, which possesses the highest specificity constant (kcat/Km) for the hydrolysis of benzylpenicillin compared with penicillin amidases from other sources. Similar to the Escherichia coli penicillin amidase, the A. faecalis penicillin amidase is maturated in vivo from an inactive precursor into the catalytically active enzyme, containing one tightly bound Ca2+ ion, via a complex post-translational autocatalytic processing with a multi-step excision of a small internal pro-peptide. The function of the pro-region is so far unknown. In vitro addition of chemically synthesized fragments of the pro-peptide to purified mature A. faecalis penicillin amidase increased its specific activity up to 2.3-fold. Mutations were used to block various steps in the proteolytic processing of the pro-peptide to obtain stable mutants with covalently attached fragments of the pro-region to their A-chains. These extensions of the A-chain raised the activity up to 2.3-fold and increased the specificity constants for benzylpenicillin hydrolysis mainly by an increase of the turnover number (kcat).

  8. The autolytic activity of the recombinant amidase of Staphylococcus saprophyticus is inhibited by its own recombinant GW repeats.

    PubMed

    Hell, Wolfgang; Reichl, Sylvia; Anders, Agnes; Gatermann, Sören

    2003-10-10

    The Aas (autolysin/adhesin of Staphylococcus saprophyticus) is a multifunctional surface protein containing two enzymatic domains an N-acetyl-muramyl-L-alanine amidase, an endo-beta-N-acetyl-D-glucosaminidase, and two different regions of repetitive sequences, an N-terminal and a C-terminal repetitive domain. The C-terminal repetitive domain is built up by the repeats R1, R2 and R3, which interconnect the putative active centers of the amidase and glucosaminidase. To investigate the influence of the C-terminal repeats and the N-terminal repeats on the amidase activity, the repetitive domains and fragments of them were cloned and expressed in Escherichia coli. The influence of the different fragments on the activity of the recombinant amidase of the Aas, consisting of the active center of the enzyme and repeat R1, was investigated in a turbidimetric microassay. The different fragments derived from the C-terminal repeats inhibited the amidase activity, while the N-terminal repeats did not influence the activity of the enzyme. The inhibiting activity increased with the number of GW repeats the recombinant fragment contained. Thus we conclude, that the C-terminal GW repeats and not the N-terminal repeats are necessary for the cell wall targeting and the autolytic function of the amidase.

  9. Crystal structures of bacterial peptidoglycan amidase AmpD and an unprecedented activation mechanism.

    PubMed

    Carrasco-López, Cesar; Rojas-Altuve, Alzoray; Zhang, Weilie; Hesek, Dusan; Lee, Mijoon; Barbe, Sophie; André, Isabelle; Ferrer, Pilar; Silva-Martin, Noella; Castro, German R; Martínez-Ripoll, Martín; Mobashery, Shahriar; Hermoso, Juan A

    2011-09-09

    AmpD is a cytoplasmic peptidoglycan (PG) amidase involved in bacterial cell-wall recycling and in induction of β-lactamase, a key enzyme of β-lactam antibiotic resistance. AmpD belongs to the amidase_2 family that includes zinc-dependent amidases and the peptidoglycan-recognition proteins (PGRPs), highly conserved pattern-recognition molecules of the immune system. Crystal structures of Citrobacter freundii AmpD were solved in this study for the apoenzyme, for the holoenzyme at two different pH values, and for the complex with the reaction products, providing insights into the PG recognition and the catalytic process. These structures are significantly different compared with the previously reported NMR structure for the same protein. The NMR structure does not possess an accessible active site and shows the protein in what is proposed herein as an inactive "closed" conformation. The transition of the protein from this inactive conformation to the active "open" conformation, as seen in the x-ray structures, was studied by targeted molecular dynamics simulations, which revealed large conformational rearrangements (as much as 17 Å) in four specific regions representing one-third of the entire protein. It is proposed that the large conformational change that would take the inactive NMR structure to the active x-ray structure represents an unprecedented mechanism for activation of AmpD. Analysis is presented to argue that this activation mechanism might be representative of a regulatory process for other intracellular members of the bacterial amidase_2 family of enzymes.

  10. Crystal Structures of Bacterial Peptidoglycan Amidase AmpD and an Unprecedented Activation Mechanism*

    PubMed Central

    Carrasco-López, Cesar; Rojas-Altuve, Alzoray; Zhang, Weilie; Hesek, Dusan; Lee, Mijoon; Barbe, Sophie; André, Isabelle; Ferrer, Pilar; Silva-Martin, Noella; Castro, German R.; Martínez-Ripoll, Martín; Mobashery, Shahriar; Hermoso, Juan A.

    2011-01-01

    AmpD is a cytoplasmic peptidoglycan (PG) amidase involved in bacterial cell-wall recycling and in induction of β-lactamase, a key enzyme of β-lactam antibiotic resistance. AmpD belongs to the amidase_2 family that includes zinc-dependent amidases and the peptidoglycan-recognition proteins (PGRPs), highly conserved pattern-recognition molecules of the immune system. Crystal structures of Citrobacter freundii AmpD were solved in this study for the apoenzyme, for the holoenzyme at two different pH values, and for the complex with the reaction products, providing insights into the PG recognition and the catalytic process. These structures are significantly different compared with the previously reported NMR structure for the same protein. The NMR structure does not possess an accessible active site and shows the protein in what is proposed herein as an inactive “closed” conformation. The transition of the protein from this inactive conformation to the active “open” conformation, as seen in the x-ray structures, was studied by targeted molecular dynamics simulations, which revealed large conformational rearrangements (as much as 17 Å) in four specific regions representing one-third of the entire protein. It is proposed that the large conformational change that would take the inactive NMR structure to the active x-ray structure represents an unprecedented mechanism for activation of AmpD. Analysis is presented to argue that this activation mechanism might be representative of a regulatory process for other intracellular members of the bacterial amidase_2 family of enzymes. PMID:21775432

  11. Identification of active sites in amidase: Evolutionary relationship between amide bond- and peptide bond-cleaving enzymes

    PubMed Central

    Kobayashi, Michihiko; Fujiwara, Yoshie; Goda, Masahiko; Komeda, Hidenobu; Shimizu, Sakayu

    1997-01-01

    Mainly based on various inhibitor studies previously performed, amidases came to be regarded as sulfhydryl enzymes. Not completely satisfied with this generally accepted interpretation, we performed a series of site-directed mutagenesis studies on one particular amidase of Rhodococcus rhodochrous J1 that was involved in its nitrile metabolism. For these experiments, the recombinant amidase was produced as the inclusion body in Escherichia coli to greatly facilitate its recovery and subsequent purification. With regard to the presumptive active site residue Cys203, a Cys203 → Ala mutant enzyme still retained 11.5% of the original specific activity. In sharp contrast, substitutions in certain other positions in the neighborhood of Cys203 had a far more dramatic effect on the amidase. Glutamic acid substitution of Asp191 reduced the specific activity of the mutant enzyme to 1.33% of the wild-type activity. Furthermore, Asp191 → Asn substitution as well as Ser195 → Ala substitution completely abolished the specific activity. It would thus appear that, among various conserved residues residing within the so-called signature sequence common to all amidases, the real active site residues are Asp191 and Ser195 rather than Cys203. Inasmuch as an amide bond (CO-NH2) in the amide substrate is not too far structurally removed from a peptide bond (CO-NH-), the signature sequences of various amidases were compared with the active site sequences of various types of proteases. It was found that aspartic acid and serine residues corresponding to Asp191 and Ser195 of the Rhodococcus amidase are present within the active site sequences of aspartic proteinases, thus suggesting the evolutionary relationship between the two. PMID:9342349

  12. An Activity-Based Probe for N-Acylethanolamine Acid Amidase

    PubMed Central

    Armirotti, Andrea; Summa, Maria; Bertozzi, Fabio; Garau, Gianpiero; Bandiera, Tiziano; Piomelli, Daniele

    2015-01-01

    N-Acylethanolamine acid amidase (NAAA) is a lysosomal cysteine hydrolase involved in the degradation of saturated and monounsaturated fatty acid ethanolamides (FAEs), a family of endogenous lipid signaling molecules that includes oleoylethanolamide (OEA) and palmitoylethanolamide (PEA). Among the reported NAAA inhibitors, α–amino–β–lactone (3–aminooxetan–2–one) derivatives have been shown to prevent FAE hydrolysis in innate-immune and neural cells and to reduce reactions to inflammatory stimuli. Recently, we disclosed two potent and selective NAAA inhibitors, the compounds ARN077 (5-phenylpentyl N-[(2S,3R)-2-methyl-4-oxo-oxetan-3-yl]carbamate) and ARN726 (4-cyclohexylbutyl-N-[(S)-2-oxoazetidin-3-yl]carbamate). The former is active in vivo by topical administration in rodent models of hyperalgesia and allodynia, while the latter exerts systemic anti-inflammatory effects in mouse models of lung inflammation. In the present study, we designed and validated a derivative of ARN726 as the first activity-based protein profiling (ABPP) probe for the in vivo detection of NAAA. The newly synthesized molecule 1 is an effective in vitro and in vivo click-chemistry activity based probe (ABP), which is able to capture the catalytically active form of NAAA in Human Embryonic Kidney 293 (HEK293) cells overexpressing human NAAA as well as in rat lung tissue. Competitive ABPP with 1 confirmed that ARN726 and ARN077 inhibit NAAA in vitro and in vivo. Compound 1 is a useful new tool to identify activated NAAA both in vitro and in vivo, and to investigate the physiological and pathological roles of this enzyme. PMID:26102511

  13. Cell Separation in Vibrio cholerae Is Mediated by a Single Amidase Whose Action Is Modulated by Two Nonredundant Activators

    PubMed Central

    Möll, Andrea; Dörr, Tobias; Alvarez, Laura; Chao, Michael C.; Davis, Brigid M.; Cava, Felipe

    2014-01-01

    Synthesis and hydrolysis of septal peptidoglycan (PG) are critical processes at the conclusion of cell division that enable separation of daughter cells. Cleavage of septal PG is mediated by PG amidases, hydrolytic enzymes that release peptide side chains from the glycan strand. Most gammaproteobacteria, including Escherichia coli, encode several functionally redundant periplasmic amidases. However, members of the Vibrio genus, including the enteric pathogen Vibrio cholerae, encode only a single PG amidase, AmiB. Here, we show that V. cholerae AmiB is crucial for cell division and growth. Genetic and biochemical analyses indicated that AmiB is regulated by two activators, EnvC and NlpD, at least one of which is required for AmiB's localization to the cell division site. Localization of the activators (and thus of AmiB) is dependent upon the cell division protein FtsN. These factors mediate septal PG cleavage in E. coli as well; however, their precise roles vary between the two organisms in a number of ways. Notably, even though V. cholerae EnvC and NlpD appear to be functionally redundant under most growth conditions tested, NlpD is specifically required for intestinal colonization in the infant mouse model of cholera and for V. cholerae resistance against bile salts, perhaps due to environmental regulation of AmiB or its activators. Collectively, our findings reveal that although the cellular components that enable cleavage of septal PG appear to be generally conserved between E. coli and V. cholerae, they can be combined into diverse functional regulatory networks. PMID:25182499

  14. Altered Activity, Social Behavior, and Spatial Memory in Mice Lacking the NTAN1p Amidase and the Asparagine Branch of the N-End Rule Pathway

    PubMed Central

    Kwon, Yong Tae; Balogh, Seth A.; Davydov, Ilia V.; Kashina, Anna S.; Yoon, Jeong Kyo; Xie, Youming; Gaur, Arti; Hyde, Lynn; Denenberg, Victor H.; Varshavsky, Alexander

    2000-01-01

    The N-end rule relates the in vivo half-life of a protein to the identity of its N-terminal residue. N-terminal asparagine and glutamine are tertiary destabilizing residues, in that they are enzymatically deamidated to yield secondary destabilizing residues aspartate and glutamate, which are conjugated to arginine, a primary destabilizing residue. N-terminal arginine of a substrate protein is bound by the Ubr1-encoded E3α, the E3 component of the ubiquitin-proteasome-dependent N-end rule pathway. We describe the construction and analysis of mouse strains lacking the asparagine-specific N-terminal amidase (NtN-amidase), encoded by the Ntan1 gene. In wild-type embryos, Ntan1 was strongly expressed in the branchial arches and in the tail and limb buds. The Ntan1−/− mouse strains lacked the NtN-amidase activity but retained glutamine-specific NtQ-amidase, indicating that the two enzymes are encoded by different genes. Among the normally short-lived N-end rule substrates, only those bearing N-terminal asparagine became long-lived in Ntan1−/− fibroblasts. The Ntan1−/− mice were fertile and outwardly normal but differed from their congenic wild-type counterparts in spontaneous activity, spatial memory, and a socially conditioned exploratory phenotype that has not been previously described with other mouse strains. PMID:10805755

  15. The CHAP domain: a large family of amidases including GSP amidase and peptidoglycan hydrolases.

    PubMed

    Bateman, Alex; Rawlings, Neil D

    2003-05-01

    Cleavage of peptidoglycan plays an important role in bacterial cell division, cell growth and cell lysis. Here, we reveal that several known peptidoglycan amidases fall into a family, which includes many proteins of previously unknown function. The family includes two different peptidoglycan cleavage activities: L-muramoyl-L-alanine amidase and D-alanyl-glycyl endopeptidase activity. The family includes the amidase portion of the bifunctional glutathionylspermidine synthase/amidase enzyme from bacteria and pathogenic trypanosomes. The glutathionylspermidine synthase is thought to be a key component of the alternative pathway in trypanosomes for protection from oxygen-radical damage and has been proposed as a potential drug target. The CHAP (cysteine, histidine-dependent amidohydrolases/peptidases) domain is often found in association with other domains that cleave peptidoglycan. The large number of multifunctional hydrolases suggests that they might act in a cooperative manner to cleave specialized substrates.

  16. Inhibitors of acrosin and granulocyte proteinases from human genital tract secretions.

    PubMed

    Schiessler, H; Arnhold, M; Ohlsson, K; Fritz, H

    1976-09-01

    Human seminal plasma contains two acid-stable proteinase inhibitors, HUSI-II (Mr approximately 6500) and HUSI-I, (Mr approximately 11 000) with different inhibition specificities. The inhibitory activity of HUSI-II is strongly limited to trypsin and acrosin; both enzyme-inhibitor complexes are very stable (e.g. bovine trypsin-HUSI-II complex: Ki = 1 x 10(-10)M; human acrosin-HUSI-II complex: Ki = 2.7 x 10(-10)M). The inhibitor from human seminal plasma HUSI-II may therefore be seen as the natural antagonist of the sperm protease acrosin. In addition to pancreatic trypsin and alpha-chymotrypsin, HUSI-I forms strong complexes with neutral proteases of the lysosome-like granules from human granulocytes, for example, the elastase (Ki = 2.5 x 10(-9)M) and cathepsin G, the chymotrypsin like protease (Ki = 7 x 10(-8)M).

  17. PL3 Amidase, a Tailor-made Lysin Constructed by Domain Shuffling with Potent Killing Activity against Pneumococci and Related Species

    PubMed Central

    Blázquez, Blas; Fresco-Taboada, Alba; Iglesias-Bexiga, Manuel; Menéndez, Margarita; García, Pedro

    2016-01-01

    The emergence and spread of antibiotic-resistant bacteria is pushing the need of alternative treatments. In this context, phage therapy is already a reality to successfully fight certain multiresistant bacteria. Among different phage gene products, murein hydrolases responsible of phage progeny liberation (also called lysins or endolysins) are weapons that target specific peptidoglycan bonds, leading to lysis and death of susceptible bacteria when added from the outside. In the pneumococcal system, all but one phage murein hydrolases reported to date share a choline-binding domain that recognizes cell walls containing choline residues in the (lipo)teichoic acids. Some purified pneumococcal or phage murein hydrolases, as well as several chimeric proteins combining natural catalytic and cell wall-binding domains (CBDs) have been used as effective antimicrobials. In this work we have constructed a novel chimeric N-acetylmuramoyl-L-alanine amidase (PL3) by fusing the catalytic domain of the Pal amidase (a phage-coded endolysin) to the CBD of the LytA amidase, the major pneumococcal autolysin. The physicochemical properties of PL3 and the bacteriolytic effect against several pneumococci (including 48 multiresistant representative strain) and related species, like Streptococcus pseudopneumoniae, Streptococcus mitis, and Streptococcus oralis, have been studied. Results have shown that low doses of PL3, in the range of 0.5–5 μg/ml, are enough to practically sterilize all choline-containing strains tested. Moreover, a single 20-μg dose of PL3 fully protected zebrafish embryos from infection by S. pneumoniae D39 strain. Importantly, PL3 keeps 95% enzymatic activity after 4 weeks at 37°C and can be lyophilized without losing activity, demonstrating a remarkable robustness. Such stability, together with a prominent efficacy against a narrow spectrum of human pathogens, confers to PL3 the characteristic to be an effective therapeutic. In addition, our results demonstrate

  18. Sperm acrosin levels in semen: comparison between ACCU-SPERM and Kennedy's methods.

    PubMed

    Ikemoto, I; Fanning, L; Loughlin, K R; Agarwal, A

    1994-01-01

    The purpose of this experiment was to evaluate the accuracy, specificity, and sensitivity of a new acrosin activity assay, ACCU-SPERM, and to correlate these results with the original Kennedy method. Thirty-nine specimens (26 patients and 13 donors) of 54 (72%) were found to be in the normal range (> 25 microIU acrosin/10(6) sperm) by the Kennedy method; the other 15 specimens were in either the indeterminate or subfertile range (< 14 microIU). However, according to the ACCU-SPERM method, (normal: 6.6-27 AAI; infertile: < 3.6), 90% of specimens (49 of 54) whose acrosin activity was measured were in the subfertile or infertile range. Similarly, only 28% (4 of 14) of donors in the ACCU-SPERM method were in the normal range in contrast to the 93% (13 of 14) in Kennedy. After calculating the ACCU-SPERM normal range in our laboratory using the linear regression curve between the acrosin values generated by the Kennedy and ACCU-SPERM methods, we again compared results of the two methods. The new normal range of > 1.82 AAI in ACCU-SPERM corresponded to > 25 microIU in the Kennedy method; similarly a value of < 1.35 AAI in ACCU-SPERM corresponded to < 14 microIU in the Kennedy technique. Analysis of the results generated by the two methods revealed a poor correlation with a positive concordance of 51% and a negative concordance of 50% in both assays. These results strongly suggest that the ACCU-SPERM method for measurement of acrosin activity is not a reliable assay.

  19. AmiE, a novel N-acylhomoserine lactone acylase belonging to the amidase family, from the activated-sludge isolate Acinetobacter sp. strain Ooi24.

    PubMed

    Ochiai, Seiji; Yasumoto, Sera; Morohoshi, Tomohiro; Ikeda, Tsukasa

    2014-11-01

    Many Gram-negative bacteria use N-acyl-l-homoserine lactones (AHLs) as quorum-sensing signal molecules. We have reported that Acinetobacter strains isolated from activated sludge have AHL-degrading activity. In this study, we cloned the amiE gene as an AHL-degradative gene from the genomic library of Acinetobacter sp. strain Ooi24. High-performance liquid chromatography analysis revealed that AmiE functions as an AHL acylase, which hydrolyzes the amide bond of AHL. AmiE showed a high level of degrading activity against AHLs with long acyl chains but no activity against AHLs with acyl chains shorter than eight carbons. AmiE showed homology with a member of the amidases (EC 3.5.1.4) but not with any known AHL acylase enzymes. An amino acid sequence of AmiE from Ooi24 showed greater than 99% identities with uncharacterized proteins from Acinetobacter ursingii CIP 107286 and Acinetobacter sp. strain CIP 102129, but it was not found in the draft or complete genome sequences of other Acinetobacter strains. The presence of transposase-like genes around the amiE genes of these three Acinetobacter strains suggests that amiE is transferred by a putative transposon. Furthermore, the expression of AmiE in Pseudomonas aeruginosa PAO1 reduced AHL accumulation and elastase activity, which were regulated by AHL-mediated quorum sensing.

  20. [Cloning and analysis of a new aliphatic amidase gene from Rhodococcus erythropolis TA37].

    PubMed

    Lavrov, K V; Karpova, I Yu; Epremyan, A S; Yanenko, A S

    2014-10-01

    A new aliphatic amidase gene (ami), having a level of similarity with the nearest homologs of no more than 77%, was identified in the Rhodococcus erythropolis TA37 strain, which is able to hydrolyze a wide range of amides. The amidase gene was cloned within a 3.7 kb chromosomal locus, which also contains putative acetyl-CoA ligase and ABC-type transportergenes. The structure of this locus in the R. erythropolis TA37 strain differs from the structure of loci in other Rhodococcus strains. The amidase gene is expressed in Escherichia coli cells. It was demonstrated that amidase (generated in the recombinant strain) efficiently hydrolyzes acetamide (aliphatic anmide) and does not use 4'-nitroacetanilide (N-substituted amide) as a substrate. Insertional inactivation of the amidase gene in the R. erythropolis TA37 strain results in a considerable decrease (by at least 6-7 times) in basal amidase activity, indicating functional amidase activity in the R. erythropolis TA37 strain.

  1. Functional Characterization of Corynebacterium glutamicum Mycothiol S-Conjugate Amidase

    PubMed Central

    Si, Meiru; Long, Mingxiu; Chaudhry, Muhammad Tausif; Xu, Yixiang; Zhang, Pan; Zhang, Lei; Shen, Xihui

    2014-01-01

    The present study focuses on the genetic and biochemical characterization of mycothiol S-conjugate amidase (Mca) of Corynebacterium glutamicum. Recombinant C. glutamicum Mca was heterologously expressed in Escherichia coli and purified to apparent homogeneity. The molecular weight of native Mca protein determined by gel filtration chromatography was 35 kDa, indicating that Mca exists as monomers in the purification condition. Mca showed amidase activity with mycothiol S-conjugate of monobromobimane (MSmB) in vivo while mca mutant lost the ability to cleave MSmB. In addition, Mca showed limited deacetylase activity with N-acetyl-D-glucosamine (GlcNAc) as substrate. Optimum pH for amidase activity was between 7.5 and 8.5, while the highest activity in the presence of Zn2+ confirmed Mca as a zinc metalloprotein. Amino acid residues conserved among Mca family members were located in C. glutamicum Mca and site-directed mutagenesis of these residues indicated that Asp14, Tyr137, His139 and Asp141 were important for activity. The mca deletion mutant showed decreased resistance to antibiotics, alkylating agents, oxidants and heavy metals, and these sensitive phenotypes were recovered in the complementary strain to a great extent. The physiological roles of Mca in resistance to various toxins were further supported by the induced expression of Mca in C. glutamicum under various stress conditions, directly under the control of the stress-responsive extracytoplasmic function-sigma (ECF-σ) factor SigH. PMID:25514023

  2. Purification and properties of an amidase from Rhodococcus erythropolis MP50 which enantioselectively hydrolyzes 2-arylpropionamides.

    PubMed Central

    Hirrlinger, B; Stolz, A; Knackmuss, H J

    1996-01-01

    An enantioselective amidase from Rhodococcus erythropolis MP50 was purified to homogeneity. The enzyme has a molecular weight of about 480,000 and is composed of identical subunits with molecular weights of about 61,000. The NH2-terminal amino acid sequence was significantly different from previously published sequences of bacterial amidases. The purified amidase hydrolyzed a wide range of aliphatic and aromatic amides, The highest enzyme activities were found with amides carrying hydrophobic residues, such as pentyl or naphthoyl. The purified enzyme converted racemic 2-phenylpropionamide, naproxen amide [2-(6-methoxy-2-naphthyl) propionamide], and ketoprofen amide [2-(3'-benzoylphenyl)propionamide] to the corresponding S-acids with an enantiomeric excess of >99% and an almost 50% conversion of the racemic amides. The enzyme also hydrolyzed different alpha-amino amides but without significant enantioselectivity. PMID:8655547

  3. l-Selective Amidase with Extremely Broad Substrate Specificity from Ochrobactrum anthropi NCIMB 40321

    PubMed Central

    Sonke, Theo; Ernste, Sandra; Tandler, Renate F.; Kaptein, Bernard; Peeters, Wilco P. H.; van Assema, Friso B. J.; Wubbolts, Marcel G.; Schoemaker, Hans E.

    2005-01-01

    An industrially attractive l-specific amidase was purified to homogeneity from Ochrobactrum anthropi NCIMB 40321 wild-type cells. The purified amidase displayed maximum initial activity between pH 6 and 8.5 and was fully stable for at least 1 h up to 60°C. The purified enzyme was strongly inhibited by the metal-chelating compounds EDTA and 1,10-phenanthroline. The activity of the EDTA-treated enzyme could be restored by the addition of Zn2+ (to 80%), Mn2+ (to 400%), and Mg2+ (to 560%). Serine and cysteine protease inhibitors did not influence the purified amidase. This enzyme displayed activity toward a broad range of substrates consisting of α-hydrogen- and (bulky) α,α-disubstituted α-amino acid amides, α-hydroxy acid amides, and α-N-hydroxyamino acid amides. In all cases, only the l-enantiomer was hydrolyzed, resulting in E values of more than 150. Simple aliphatic amides, β-amino and β-hydroxy acid amides, and dipeptides were not converted. The gene encoding this l-amidase was cloned via reverse genetics. It encodes a polypeptide of 314 amino acids with a calculated molecular weight of 33,870. Since the native enzyme has a molecular mass of about 66 kDa, it most likely has a homodimeric structure. The deduced amino acid sequence showed homology to a few other stereoselective amidases and the acetamidase/formamidase family of proteins (Pfam FmdA_AmdA). Subcloning of the gene in expression vector pTrc99A enabled efficient heterologous expression in Escherichia coli. Altogether, this amidase has a unique set of properties for application in the fine-chemicals industry. PMID:16332774

  4. An intravaginal contraceptive device for the delivery of an acrosin and hyaluronidase inhibitor.

    PubMed

    Burck, P J; Zimmerman, R E

    1984-02-01

    A study was begun to develop a contraceptive delivery system that would free the user from precoital or daily administration and utilize a nonhormonal agent as the active ingredient. Testing of such a system in rabbits has led to the development of a device that will release a controlled level of an acrosin and hyaluronidase inhibitor into the vagina. This toroidal device is composed of a core of tetradecyl sodium sulfate (TDSS) incorporated in polyurethane surrounded by a rate-limiting membrane of polyurethane. Such devices had a sustained in vitro TDSS release rate of greater than or equal to 400 micrograms/day for over 30 days. These devices had a complete contraceptive effect in 15 rabbits bred weekly for 4 weeks. The contraceptive effect is due to release of the TDSS into the vagina and the subsequent binding of the TDSS to spermatozoa in the female reproductive tract. TDSS has a very low toxicity profile in the rat, dog, and rabbit.

  5. Crystallization, diffraction data collection and preliminary crystallographic analysis of hexagonal crystals of Pseudomonas aeruginosa amidase

    SciTech Connect

    Andrade, Jorge; Karmali, Amin; Carrondo, Maria A.; Frazão, Carlos

    2007-03-01

    Crystals of aliphatic amidase (acylamide amidohydrolase; EC 3.5.1.4) from P. aeruginosa were obtained in space group P6{sub 3}22 and diffracted to 1.25 Å resolution. The aliphatic amidase (acylamide amidohydrolase; EC 3.5.1.4) from Pseudomonas aeruginosa is a hexameric enzyme composed of six identical subunits with a molecular weight of ∼38 kDa. Since microbial amidases are very important enzymes in industrial biocatalysis, the structural characterization of this enzyme will help in the design of novel catalytic activities of commercial interest. The present study reports the successful crystallization of the wild-type amidase from P. aeruginosa. Native crystals were obtained and a complete data set was collected at 1.4 Å resolution, although the crystals showed diffraction to 1.25 Å resolution. The crystals were found to belong to space group P6{sub 3}22, with unit-cell parameters a = b = 102.60, c = 151.71 Å, and contain one molecule in the asymmetric unit.

  6. Purification, cloning, and primary structure of a new enantiomer-selective amidase from a Rhodococcus strain: structural evidence for a conserved genetic coupling with nitrile hydratase.

    PubMed

    Mayaux, J F; Cerbelaud, E; Soubrier, F; Yeh, P; Blanche, F; Pétré, D

    1991-11-01

    A new enantiomer-selective amidase active on several 2-aryl propionamides was identified and purified from a newly isolated Rhodococcus strain. The characterized amidase is an apparent homodimer, each molecule of which has an Mr of 48,554; it has a specific activity of 16.5 mumol of S(+)-2-phenylpropionic acid formed per min per mg of enzyme from the racemic amide under our conditions. An oligonucleotide probe was deduced from limited peptide information and was used to clone the corresponding gene, named amdA. As expected, significant homologies were found between the amino acid sequences of the enantiomer-selective amidase of Rhodococcus sp., the corresponding enzyme from Brevibacterium sp. strain R312, and several known amidases, thus confirming the existence of a structural class of amidase enzymes. Genes probably coding for the two subunits of a nitrile hydratase, albeit in an inverse order, were found 39 bp downstream of amdA, suggesting that such a genetic organization might be conserved in different microorganisms. Although we failed to express an active Rhodococcus amidase in Escherichia coli, even in conditions allowing the expression of an active R312 enzyme, the high-level expression of the active recombinant enzyme could be demonstrated in Brevibacterium lactofermentum by using a pSR1-derived shuttle vector.

  7. Purification, cloning, and primary structure of a new enantiomer-selective amidase from a Rhodococcus strain: structural evidence for a conserved genetic coupling with nitrile hydratase.

    PubMed Central

    Mayaux, J F; Cerbelaud, E; Soubrier, F; Yeh, P; Blanche, F; Pétré, D

    1991-01-01

    A new enantiomer-selective amidase active on several 2-aryl propionamides was identified and purified from a newly isolated Rhodococcus strain. The characterized amidase is an apparent homodimer, each molecule of which has an Mr of 48,554; it has a specific activity of 16.5 mumol of S(+)-2-phenylpropionic acid formed per min per mg of enzyme from the racemic amide under our conditions. An oligonucleotide probe was deduced from limited peptide information and was used to clone the corresponding gene, named amdA. As expected, significant homologies were found between the amino acid sequences of the enantiomer-selective amidase of Rhodococcus sp., the corresponding enzyme from Brevibacterium sp. strain R312, and several known amidases, thus confirming the existence of a structural class of amidase enzymes. Genes probably coding for the two subunits of a nitrile hydratase, albeit in an inverse order, were found 39 bp downstream of amdA, suggesting that such a genetic organization might be conserved in different microorganisms. Although we failed to express an active Rhodococcus amidase in Escherichia coli, even in conditions allowing the expression of an active R312 enzyme, the high-level expression of the active recombinant enzyme could be demonstrated in Brevibacterium lactofermentum by using a pSR1-derived shuttle vector. Images FIG. 5 PMID:1938876

  8. Purification, characterization, gene cloning and nucleotide sequencing of D: -stereospecific amino acid amidase from soil bacterium: Delftia acidovorans.

    PubMed

    Hongpattarakere, Tipparat; Komeda, Hidenobu; Asano, Yasuhisa

    2005-12-01

    The D-amino acid amidase-producing bacterium was isolated from soil samples using an enrichment culture technique in medium broth containing D-phenylalanine amide as a sole source of nitrogen. The strain exhibiting the strongest activity was identified as Delftia acidovorans strain 16. This strain produced intracellular D-amino acid amidase constitutively. The enzyme was purified about 380-fold to homogeneity and its molecular mass was estimated to be about 50 kDa, on sodium dodecyl sulfate polyacrylamide gel electrophoresis. The enzyme was active preferentially toward D-amino acid amides rather than their L-counterparts. It exhibited strong amino acid amidase activity toward aromatic amino acid amides including D-phenylalanine amide, D-tryptophan amide and D-tyrosine amide, yet it was not specifically active toward low-molecular-weight D-amino acid amides such as D-alanine amide, L-alanine amide and L-serine amide. Moreover, it was not specifically active toward oligopeptides. The enzyme showed maximum activity at 40 degrees C and pH 8.5 and appeared to be very stable, with 92.5% remaining activity after the reaction was performed at 45 degrees C for 30 min. However, it was mostly inactivated in the presence of phenylmethanesulfonyl fluoride or Cd2+, Ag+, Zn2+, Hg2+ and As3+ . The NH2 terminal and internal amino acid sequences of the enzyme were determined; and the gene was cloned and sequenced. The enzyme gene damA encodes a 466-amino-acid protein (molecular mass 49,860.46 Da); and the deduced amino acid sequence exhibits homology to the D-amino acid amidase from Variovorax paradoxus (67.9% identity), the amidotransferase A subunit from Burkholderia fungorum (50% identity) and other enantioselective amidases.

  9. A Novel Amidase (Half-Amidase) for Half-Amide Hydrolysis Involved in the Bacterial Metabolism of Cyclic Imides

    PubMed Central

    Soong, Chee-Leong; Ogawa, Jun; Shimizu, Sakayu

    2000-01-01

    A novel amidase involved in bacterial cyclic imide metabolism was purified from Blastobacter sp. strain A17p-4. The enzyme physiologically functions in the second step of cyclic imide degradation, i.e., the hydrolysis of monoamidated dicarboxylates (half-amides) to dicarboxylates and ammonia. Enzyme production was enhanced by cyclic imides such as succinimide and glutarimide but not by amide compounds which are conventional substrates and inducers of known amidases. The purified amidase showed high catalytic efficiency toward half-amides such as succinamic acid (Km = 6.2 mM; kcat = 5.76 s−1) and glutaramic acid (Km = 2.8 mM; kcat = 2.23 s−1). However, the substrates of known amidases such as short-chain (C2 to C4) aliphatic amides, long-chain (above C16) aliphatic amides, amino acid amides, aliphatic diamides, α-keto acid amides, N-carbamoyl amino acids, and aliphatic ureides were not substrates for the enzyme. Based on its high specificity toward half-amides, the enzyme was named half-amidase. This half-amidase exists as a monomer with an Mr of 48,000 and was strongly inhibited by heavy metal ions and sulfhydryl reagents. PMID:10788365

  10. Endogenous molecules stimulating N-acylethanolamine-hydrolyzing acid amidase (NAAA).

    PubMed

    Tai, Tatsuya; Tsuboi, Kazuhito; Uyama, Toru; Masuda, Kim; Cravatt, Benjamin F; Houchi, Hitoshi; Ueda, Natsuo

    2012-05-16

    Fatty acid amide hydrolase (FAAH) plays the central role in the degradation of bioactive N-acylethanolamines such as the endocannabinoid arachidonoylethanolamide (anandamide) in brain and peripheral tissues. A lysosomal enzyme referred to as N-acylethanolamine-hydrolyzing acid amidase (NAAA) catalyzes the same reaction with preference to palmitoylethanolamide, an endogenous analgesic and neuroprotective substance, and is therefore expected as a potential target of therapeutic drugs. In the in vitro assays thus far performed, the maximal activity of NAAA was achieved in the presence of both nonionic detergent (Triton X-100 or Nonidet P-40) and the SH reagent dithiothreitol. However, endogenous molecules that might substitute for these synthetic compounds remain poorly understood. Here, we examined stimulatory effects of endogenous phospholipids and thiol compounds on recombinant NAAA. Among different phospholipids tested, choline- or ethanolamine-containing phospholipids showed potent effects, and 1 mM phosphatidylcholine increased NAAA activity by 6.6-fold. Concerning endogenous thiol compounds, dihydrolipoic acid at 0.1-1 mM was the most active, causing 8.5-9.0-fold stimulation. These results suggest that endogenous phospholipids and dihydrolipoic acid may contribute in keeping NAAA active in lysosomes. Even in the presence of phosphatidylcholine and dihydrolipoic acid, however, the preferential hydrolysis of palmitoylethanolamide was unaltered. We also investigated a possible compensatory induction of NAAA mRNA in brain and other tissues of FAAH-deficient mice. However, NAAA expression levels in all the tissues examined were not significantly altered from those in wild-type mice.

  11. A cytoplasmic peptidoglycan amidase homologue controls mycobacterial cell wall synthesis

    PubMed Central

    Boutte, Cara C; Baer, Christina E; Papavinasasundaram, Kadamba; Liu, Weiru; Chase, Michael R; Meniche, Xavier; Fortune, Sarah M; Sassetti, Christopher M; Ioerger, Thomas R; Rubin, Eric J

    2016-01-01

    Regulation of cell wall assembly is essential for bacterial survival and contributes to pathogenesis and antibiotic tolerance in Mycobacterium tuberculosis (Mtb). However, little is known about how the cell wall is regulated in stress. We found that CwlM, a protein homologous to peptidoglycan amidases, coordinates peptidoglycan synthesis with nutrient availability. Surprisingly, CwlM is sequestered from peptidoglycan (PG) by localization in the cytoplasm, and its enzymatic function is not essential. Rather, CwlM is phosphorylated and associates with MurA, the first enzyme in PG precursor synthesis. Phosphorylated CwlM activates MurA ~30 fold. CwlM is dephosphorylated in starvation, resulting in lower MurA activity, decreased cell wall metabolism, and increased tolerance to multiple antibiotics. A phylogenetic analysis of cwlM implies that localization in the cytoplasm drove the evolution of this factor. We describe a system that controls cell wall metabolism in response to starvation, and show that this regulation contributes to antibiotic tolerance. DOI: http://dx.doi.org/10.7554/eLife.14590.001 PMID:27304077

  12. Substitution of Glu-59 by Val in amidase from Pseudomonas aeruginosa results in a catalytically inactive enzyme.

    PubMed

    Karmali, A; Tata, R; Brown, P R

    2000-09-01

    A mutant strain, KLAM59, of Pseudomonas aeruginosa has been isolated that synthesizes a catalytically inactive amidase. The mutation in the amidase gene has been identified (Glu59Val) by direct sequencing of PCR-amplified mutant gene and confirmed by sequencing the cloned PCR-amplified gene. The wild-type and altered amidase genes were cloned into an expression vector and both enzymes were purified by affinity chromatography on epoxy-activated Sepharose 6B-acetamide followed by gel filtration chromatography. The mutant enzyme was catalytically inactive, and it was detected in column fractions by monoclonal antibodies previously raised against the wild-type enzyme using an ELISA sandwich method. The recombinant wild-type and mutant enzymes were purified with a final recovery of enzyme in the range of 70-80%. The wild-type and mutant enzymes behaved differently on the affinity column as shown by their elution profiles. The molecular weights of the purified wild-type and mutant amidases were found to be 210,000 and 78,000 Dalton, respectively, by gel filtration chromatography. On the other hand, the mutant enzyme ran as a single protein band on SDS-PAGE and native PAGE with a M(r) of 38,000 and 78,000 Dalton, respectively. These data suggest that the substitution Glu59Val was responsible for the dimeric structure of the mutant enzyme as opposed to the hexameric form of the wild-type enzyme. Therefore, the Glu59 seems to be a critical residue in the maintenance of the native quaternary structure of amidase.

  13. Endogenous Molecules Stimulating N-Acylethanolamine-Hydrolyzing Acid Amidase (NAAA)

    PubMed Central

    2012-01-01

    Fatty acid amide hydrolase (FAAH) plays the central role in the degradation of bioactive N-acylethanolamines such as the endocannabinoid arachidonoylethanolamide (anandamide) in brain and peripheral tissues. A lysosomal enzyme referred to as N-acylethanolamine-hydrolyzing acid amidase (NAAA) catalyzes the same reaction with preference to palmitoylethanolamide, an endogenous analgesic and neuroprotective substance, and is therefore expected as a potential target of therapeutic drugs. In the in vitro assays thus far performed, the maximal activity of NAAA was achieved in the presence of both nonionic detergent (Triton X-100 or Nonidet P-40) and the SH reagent dithiothreitol. However, endogenous molecules that might substitute for these synthetic compounds remain poorly understood. Here, we examined stimulatory effects of endogenous phospholipids and thiol compounds on recombinant NAAA. Among different phospholipids tested, choline- or ethanolamine-containing phospholipids showed potent effects, and 1 mM phosphatidylcholine increased NAAA activity by 6.6-fold. Concerning endogenous thiol compounds, dihydrolipoic acid at 0.1–1 mM was the most active, causing 8.5–9.0-fold stimulation. These results suggest that endogenous phospholipids and dihydrolipoic acid may contribute in keeping NAAA active in lysosomes. Even in the presence of phosphatidylcholine and dihydrolipoic acid, however, the preferential hydrolysis of palmitoylethanolamide was unaltered. We also investigated a possible compensatory induction of NAAA mRNA in brain and other tissues of FAAH-deficient mice. However, NAAA expression levels in all the tissues examined were not significantly altered from those in wild-type mice. PMID:22860206

  14. Bioreactor cultivation of Escherichia coli for production of recombinant penicillin G amidase from Alcaligenes faecalis.

    PubMed

    Deak, Peter M; Lutz-Wahl, Sabine; Bothe, Harald; Fischer, Lutz

    2003-03-01

    The penicillin G amidase (PGA) from Alcaligenes faecalis, which has interesting properties for use in combinatorial biochemistry, was produced by recombinant expression in Escherichia coli. The corresponding gene was cloned into a multicopy vector under the strict regulatory control of the rhamnose inducible promoter. Cells were grown in a synthetic minimal medium in a bioreactor (5 l working vol.), and production of PGA was induced by repeated addition of the inducer rhamnose, that served also as a carbon source. The fermentation yield was about 4500 units PGA activity per liter of culture medium.

  15. Substitutions of Thr-103-Ile and Trp-138-Gly in amidase from Pseudomonas aeruginosa are responsible for altered kinetic properties and enzyme instability.

    PubMed

    Karmali, A; Pacheco, R; Tata, R; Brown, P

    2001-03-01

    Pseudomonas aeruginosa Ph1 is a mutant strain derived from strain AI3. The strain AI3 is able to use acetanilide as a carbon source through a mutation (T103I) in the amiE gene that encodes an aliphatic amidase (EC 3.5.1.4). The mutations in the amiE gene have been identified (Thr103Ile and Trp138Gly) by direct sequencing of PCR-amplified mutant gene from strain Ph1 and confirmed by sequencing the cloned PCR-amplified gene. Site-directed mutagenesis was used to alter the wild-type amidase gene at position 138 for Gly. The wild-type and mutant amidase genes (W138G, T103I-W138G, and T103I) were cloned into an expression vector and these enzymes were purified by affinity chromatography on epoxy-activated Sepharose 6B-acetamide/phenylacetamide followed by gel filtration chromatography. Altered amidases revealed several differences in kinetic properties, namely, in substrate specificity, sensitivity to urea, optimum pH, and enzyme stability, compared with the wild-type enzyme. The W138G enzyme acted on acetamide, acrylamide, phenylacetamide, and p-nitrophenylacetamide, whereas the double mutant (W138G and T103I) amidase acted only on p-nitrophenylacetamide and phenylacetamide. On the other hand, the T103I enzyme acted on p-nitroacetanilide and acetamide. The heat stability of altered enzymes revealed that they were less thermostable than the wild-type enzyme, as the mutant (W138G and W138G-T103I) enzymes exhibited t1/2 values of 7.0 and 1.5 min at 55 degrees C, respectively. The double substitution T103I and W138G on the amidase molecule was responsible for increased instability due to a conformational change in the enzyme molecule as detected by monoclonal antibodies. This conformational change in altered amidase did not alter its M(r) value and monoclonal antibodies reacted differently with the active and inactive T103I-W138G amidase.

  16. A breakthrough in enzyme technology to fight penicillin resistance-industrial application of penicillin amidase.

    PubMed

    Buchholz, Klaus

    2016-05-01

    Enzymatic penicillin hydrolysis by penicillin amidase (also penicillin acylase, PA) represents a Landmark: the first industrially and economically highly important process using an immobilized biocatalyst. Resistance of infective bacteria to antibiotics had become a major topic of research and industrial activities. Solutions to this problem, the antibiotics resistance of infective microorganisms, required the search for new antibiotics, but also the development of derivatives, notably penicillin derivatives, that overcame resistance. An obvious route was to hydrolyse penicillin to 6-aminopenicillanic acid (6-APA), as a first step, for the introduction via chemical synthesis of various different side chains. Hydrolysis via chemical reaction sequences was tedious requiring large amounts of toxic chemicals, and they were cost intensive. Enzymatic hydrolysis using penicillin amidase represented a much more elegant route. The basis for such a solution was the development of techniques for enzyme immobilization, a highly difficult task with respect to industrial application. Two pioneer groups started to develop solutions to this problem in the late 1960s and 1970s: that of Günter Schmidt-Kastner at Bayer AG (Germany) and that of Malcolm Lilly of Imperial College London. Here, one example of this development, that at Bayer, will be presented in more detail since it illustrates well the achievement of a solution to the problems of industrial application of enzymatic processes, notably development of an immobilization method for penicillin amidase suitable for scale up to application in industrial reactors under economic conditions. A range of bottlenecks and technical problems of large-scale application had to be overcome. Data giving an inside view of this pioneer achievement in the early phase of the new field of biocatalysis are presented. The development finally resulted in a highly innovative and commercially important enzymatic process to produce 6-APA that

  17. Structure-function analysis of Staphylococcus aureus amidase reveals the determinants of peptidoglycan recognition and cleavage.

    PubMed

    Büttner, Felix Michael; Zoll, Sebastian; Nega, Mulugeta; Götz, Friedrich; Stehle, Thilo

    2014-04-18

    The bifunctional major autolysin AtlA of Staphylococcus aureus cleaves the bacterium's peptidoglycan network (PGN) at two distinct sites during cell division. Deletion of the enzyme results in large cell clusters with disordered division patterns, indicating that AtlA could be a promising target for the development of new antibiotics. One of the two functions of AtlA is performed by the N-acetylmuramyl-l-alanine amidase AmiA, which cleaves the bond between the carbohydrate and the peptide moieties of PGN. To establish the structural requirements of PGN recognition and the enzymatic mechanism of cleavage, we solved the crystal structure of the catalytic domain of AmiA (AmiA-cat) in complex with a peptidoglycan-derived ligand at 1.55 Å resolution. The peptide stem is clearly visible in the structure, forming extensive contacts with protein residues by docking into an elongated groove. Less well defined electron density and the analysis of surface features indicate likely positions of the carbohydrate backbone and the pentaglycine bridge. Substrate specificity analysis supports the importance of the pentaglycine bridge for fitting into the binding cleft of AmiA-cat. PGN of S. aureus with l-lysine tethered with d-alanine via a pentaglycine bridge is completely hydrolyzed, whereas PGN of Bacillus subtilis with meso-diaminopimelic acid directly tethered with d-alanine is not hydrolyzed. An active site mutant, H370A, of AmiA-cat was completely inactive, providing further support for the proposed catalytic mechanism of AmiA. The structure reported here is not only the first of any bacterial amidase in which both the PGN component and the water molecule that carries out the nucleophilic attack on the carbonyl carbon of the scissile bond are present; it is also the first peptidoglycan amidase complex structure of an important human pathogen.

  18. Characterization of a Thermostable d-Stereospecific Alanine Amidase from Brevibacillus borstelensis BCS-1

    PubMed Central

    Baek, Dae Heoun; Kwon, Seok-Joon; Hong, Seung-Pyo; Kwak, Mi-Sun; Lee, Mi-Hwa; Song, Jae Jun; Lee, Seung-Goo; Yoon, Ki-Hong; Sung, Moon-Hee

    2003-01-01

    A gene encoding a new thermostable d-stereospecific alanine amidase from the thermophile Brevibacillus borstelensis BCS-1 was cloned and sequenced. The molecular mass of the purified enzyme was estimated to be 199 kDa after gel filtration chromatography and about 30 kDa on sodium dodecyl sulfate-polyacrylamide gel electrophoresis, indicating that the enzyme could be composed of a hexamer with identical subunits. The purified enzyme exhibited strong amidase activity towards d-amino acid-containing aromatic, aliphatic, and branched amino acid amides yet exhibited no enzyme activity towards l-amino acid amides, d-amino acid-containing peptides, and NH2-terminally protected amino acid amides. The optimum temperature and pH for the enzyme activity were 85°C and 9.0, respectively. The enzyme remained stable within a broad pH range from 7.0 to 10.0. The enzyme was inhibited by dithiothreitol, 2-mercaptoethanol, and EDTA yet was strongly activated by Co2+ and Mn2+. The kcat/Km for d-alaninamide was measured as 544.4 ± 5.5 mM−1 min−1 at 50°C with 1 mM Co2+. PMID:12571020

  19. Identification and characterization of a novel D-amidase gene from Variovorax paradoxus and its expression in Escherichia coli.

    PubMed

    Krieg, L; Slusarczyk, H; Verseck, S; Kula, M-R

    2005-02-01

    The gene for the newly described D-amidase from Variovorax paradoxus (Krieg et al. 2002) was cloned and functionally expressed in Escherichia coli. Since native enzyme was available in minute amounts only, we determined the N-terminal sequence of the enzyme and utilized the Universal GenomeWalker Approach to make use of the common internal sequence of the amidase signature family. The high GC content of the gene made it necessary to employ an appropriate DNA polymerase in the amplification reactions. Thus, the sequence of the complete gene and the flanking regions was established. In independent experiments, the gene was then amplified from genomic DNA of V. paradoxus, expressed in E. coli, and characterized. The recombinant enzyme has a specific activity of 1.7 units/mg with racemic tert-leucine amide as substrate and is a homodimer of 49.6-kDa monomers.

  20. Protein S-thiolation by Glutathionylspermidine (Gsp): the role of Escherichia coli Gsp synthetASE/amidase in redox regulation.

    PubMed

    Chiang, Bing-Yu; Chen, Tzu-Chieh; Pai, Chien-Hua; Chou, Chi-Chi; Chen, Hsuan-He; Ko, Tzu-Ping; Hsu, Wen-Hung; Chang, Chun-Yang; Wu, Whei-Fen; Wang, Andrew H-J; Lin, Chun-Hung

    2010-08-13

    Certain bacteria synthesize glutathionylspermidine (Gsp), from GSH and spermidine. Escherichia coli Gsp synthetase/amidase (GspSA) catalyzes both the synthesis and hydrolysis of Gsp. Prior to the work reported herein, the physiological role(s) of Gsp or how the two opposing GspSA activities are regulated had not been elucidated. We report that Gsp-modified proteins from E. coli contain mixed disulfides of Gsp and protein thiols, representing a new type of post-translational modification formerly undocumented. The level of these proteins is increased by oxidative stress. We attribute the accumulation of such proteins to the selective inactivation of GspSA amidase activity. X-ray crystallography and a chemical modification study indicated that the catalytic cysteine thiol of the GspSA amidase domain is transiently inactivated by H(2)O(2) oxidation to sulfenic acid, which is stabilized by a very short hydrogen bond with a water molecule. We propose a set of reactions that explains how the levels of Gsp and Gsp S-thiolated proteins are modulated in response to oxidative stress. The hypersensitivities of GspSA and GspSA/glutaredoxin null mutants to H(2)O(2) support the idea that GspSA and glutaredoxin act synergistically to regulate the redox environment of E. coli.

  1. Purification, cloning, and primary structure of an enantiomer-selective amidase from Brevibacterium sp. strain R312: structural evidence for genetic coupling with nitrile hydratase.

    PubMed Central

    Mayaux, J F; Cerebelaud, E; Soubrier, F; Faucher, D; Pétré, D

    1990-01-01

    An enantiomer-selective amidase active on several 2-aryl and 2-aryloxy propionamides was identified and purified from Brevibacterium sp. strain R312. Oligonucleotide probes were designed from limited peptide sequence information and were used to clone the corresponding gene, named amdA. Highly significant homologies were found at the amino acid level between the deduced sequence of the enantiomer-selective amidase and the sequences of known amidases such as indoleacetamide hydrolases from Pseudomonas syringae and Agrobacterium tumefaciens and acetamidase from Aspergillus nidulans. Moreover, amdA is found in the same orientation and only 73 bp upstream from the gene coding for nitrile hydratase, strongly suggesting that both genes are part of the same operon. Our results also showed that Rhodococcus sp. strain N-774 and Brevibacterium sp. strain R312 are probably identical, or at least very similar, microorganisms. The characterized amidase is an apparent homodimer of Mr 2 x 54,671 which exhibited under our conditions a specific activity of about 13 to 17 mumol of 2-(4-hydroxyphenoxy)propionic R acid formed per min per mg of enzyme from the racemic amide. Large amounts of an active recombinant enzyme could be produced in Escherichia coli at 30 degrees C under the control of an E. coli promoter and ribosome-binding site. Images PMID:2254253

  2. Functional Characterization of a Novel Amidase Involved in Biotransformation of Triclocarban and its Dehalogenated Congeners in Ochrobactrum sp. TCC-2.

    PubMed

    Yun, Hui; Liang, Bin; Qiu, Jiguo; Zhang, Long; Zhao, Youkang; Jiang, Jiandong; Wang, Aijie

    2017-01-03

    Haloaromatic antimicrobial triclocarban (3,4,4'-trichlorocarbanilide, TCC) is a refractory contaminant which is frequently detected in various aquatic and sediment environments globally. However, few TCC-degrading communities or pure cultures have been documented, and functional enzymes involved in TCC biodegradation hitherto have not yet been characterized. In this study, a bacterial strain, Ochrobactrum sp. TCC-2, capable of degrading TCC under both aerobic and anaerobic conditions was isolated from a sediment sample. A novel amidase gene (tccA), responsible for the hydrolysis of the two amide bonds of TCC and its dehalogenated congeners 4,4'-dichlorocarbanilide (DCC) and carbanilide (NCC) to more biodegradable chloroaniline or aniline products, was cloned and characterized. TccA shares low amino acid sequence identity (27 to 38%) with other biochemically characterized amidases and contains the conserved catalytic triad (Ser-Ser-Lys) of the amidase signature enzyme family. TccA was stable over a pH range of 5.0 to 10.0 and at temperatures lower than 60 °C, and it was constitutively expressed in strain TCC-2. In contrast to the halogenated TCC and DCC, the nonchlorinated NCC was the preferred substrate for TccA. TccA also had hydrolysis activity to a broad spectrum of amide bonds in herbicides, insecticides, and chemical intermediates. The constitutive expression and broad substrate spectrum of TccA suggested strain TCC-2 may be potentially useful for bioremediation applications.

  3. Structure-Guided Functional Characterization of DUF1460 Reveals a New, Highly Specific NlpC/P60 Amidase Family

    PubMed Central

    Xu, Qingping; Mengin-Lecreulx, Dominique; Patin, Delphine; Grant, Joanna C.; Chiu, Hsiu-Ju; Jaroszewski, Lukasz; Knuth, Mark W.; Godzik, Adam; Lesley, Scott A.; Elsliger, Marc-André; Deacon, Ashley M.; Wilson, Ian A.

    2014-01-01

    SUMMARY GlcNAc-1,6-anhydro-MurNAc-tetrapeptide is a major peptidoglycan degradation intermediate and a cytotoxin. It is generated by lytic transglycosylases and further degraded and recycled by various enzymes. We have identified and characterized a novel, highly specific N-acetylmuramoyl-L-alanine amidase (AmiA) from Bacteroides uniformis, a member of the DUF1460 protein family, that hydrolyzes GlcNAc-1,6-anhydro-MurNAc-peptide into disaccharide and stem peptide. The high-resolution apo-structure at 1.15 Å resolution shows that AmiA is related to NlpC/P60 γ-D-Glu-meso-diaminopimelic acid amidases and shares a common catalytic core and cysteine peptidase-like active site. AmiA has evolved structural adaptations that reconfigure the substrate recognition site. The preferred substrates for AmiA were predicted in silico based on structural and bioinformatics data, and were subsequently characterized experimentally. Further crystal structures of AmiA in complexes with GlcNAc-1,6-anhydro-MurNAc and GlcNAc have enabled us to elucidate substrate recognition and specificity. DUF1460 is highly conserved in structure and defines a new amidase family. PMID:25465128

  4. Structure-guided functional characterization of DUF1460 reveals a highly specific NlpC/P60 amidase family.

    PubMed

    Xu, Qingping; Mengin-Lecreulx, Dominique; Patin, Delphine; Grant, Joanna C; Chiu, Hsiu-Ju; Jaroszewski, Lukasz; Knuth, Mark W; Godzik, Adam; Lesley, Scott A; Elsliger, Marc-André; Deacon, Ashley M; Wilson, Ian A

    2014-12-02

    GlcNAc-1,6-anhydro-MurNAc-tetrapeptide is a major peptidoglycan degradation intermediate and a cytotoxin. It is generated by lytic transglycosylases and further degraded and recycled by various enzymes. We have identified and characterized a highly specific N-acetylmuramoyl-L-alanine amidase (AmiA) from Bacteroides uniformis, a member of the DUF1460 protein family, that hydrolyzes GlcNAc-1,6-anhydro-MurNAc-peptide into disaccharide and stem peptide. The high-resolution apo structure at 1.15 Å resolution shows that AmiA is related to NlpC/P60 γ-D-Glu-meso-diaminopimelic acid amidases and shares a common catalytic core and cysteine peptidase-like active site. AmiA has evolved structural adaptations that reconfigure the substrate recognition site. The preferred substrates for AmiA were predicted in silico based on structural and bioinformatics data, and subsequently were characterized experimentally. Further crystal structures of AmiA in complexes with GlcNAc-1,6-anhydro-MurNAc and GlcNAc have enabled us to elucidate substrate recognition and specificity. DUF1460 is highly conserved in structure and defines another amidase family.

  5. Hydrazidase, a Novel Amidase Signature Enzyme That Hydrolyzes Acylhydrazides

    PubMed Central

    Oinuma, Ken-Ichi; Takuwa, Atsushi; Taniyama, Kosuke; Doi, Yuki

    2015-01-01

    The degradation mechanisms of natural and artificial hydrazides have been elucidated. Here we screened and isolated bacteria that utilize the acylhydrazide 4-hydroxybenzoic acid 1-phenylethylidene hydrazide (HBPH) from soils. Physiological and phylogenetic studies identified one bacterium as Microbacterium sp. strain HM58-2, from which we purified intracellular hydrazidase, cloned its gene, and prepared recombinant hydrazidase using an Escherichia coli expression system. The Microbacterium sp. HM58-2 hydrazidase is a 631-amino-acid monomer that was 31% identical to indoleacetamide hydrolase isolated from Bradyrhizobium japonicum. Phylogenetic studies indicated that the Microbacterium sp. HM58-2 hydrazidase constitutes a novel hydrazidase group among amidase signature proteins that are distributed within proteobacteria, actinobacteria, and firmicutes. The hydrazidase stoichiometrically hydrolyzed the acylhydrazide residue of HBPH to the corresponding acid and hydrazine derivative. Steady-state kinetics showed that the enzyme hydrolyzes structurally related 4-hydrozybenzamide to hydroxybenzoic acid at a lower rate than HBPH, indicating that the hydrazidase prefers hydrazide to amide. The hydrazidase contains the catalytic Ser-Ser-Lys motif that is conserved among members of the amidase signature family; it shares a catalytic mechanism with amidases, according to mutagenesis findings, and another hydrazidase-specific mechanism must exist that compensates for the absence of the catalytic Ser residue. The finding that an environmental bacterium produces hydrazidase implies the existence of a novel bacterial mechanism of hydrazide degradation that impacts its ecological role. PMID:25583978

  6. Nitrile Hydratase and Amidase from Rhodococcus rhodochrous Hydrolyze Acrylic Fibers and Granular Polyacrylonitriles

    PubMed Central

    Tauber, M. M.; Cavaco-Paulo, A.; Robra, K.-H.; Gübitz, G. M.

    2000-01-01

    Rhodococcus rhodochrous NCIMB 11216 produced nitrile hydratase (320 nkat mg of protein−1) and amidase activity (38.4 nkat mg of protein−1) when grown on a medium containing propionitrile. These enzymes were able to hydrolyze nitrile groups of both granular polyacrylonitriles (PAN) and acrylic fibers. Nitrile groups of PAN40 (molecular mass, 40 kDa) and PAN190 (molecular mass, 190 kDa) were converted into the corresponding carbonic acids to 1.8 and 1.0%, respectively. In contrast, surfacial nitrile groups of acrylic fibers were only converted to the corresponding amides. X-ray photoelectron spectroscopy analysis showed that 16% of the surfacial nitrile groups were hydrolyzed by the R. rhodochrous enzymes. Due to the enzymatic modification, the acrylic fibers became more hydrophilic and thus, adsorption of dyes was enhanced. This was indicated by a 15% increase in the staining level (K/S value) for C.I. Basic Blue 9. PMID:10742253

  7. Structure and mechanism of Escherichia coli glutathionylspermidine amidase belonging to the family of cysteine; histidine-dependent amidohydrolases/peptidases.

    PubMed

    Pai, Chien-Hua; Wu, Hsing-Ju; Lin, Chun-Hung; Wang, Andrew H-J

    2011-03-01

    The bifunctional Escherichia coli glutathionylspermidine synthetase/amidase (GspSA) catalyzes both the synthesis and hydrolysis of Gsp. Its amidase domain (GspA), which catalyzes the hydrolysis of Gsp into glutathione and spermidine, plays an important role in redox sensing and protein S-thiolation. To gain insight of the regulation and catalytic mechanism of and further understand the recycling of the Gsp dimer and Gsp-S-protein adducts, we solved two crystal structures of GspA and GspSA both with the C59A mutation and bound with the substrate, Gsp. In both structures, Cys59, His131, and Glu147 form the catalytic triad, which is similar to other cysteine proteases. Comparison of the GspA_Gsp complex and apo GspSA structures indicates that on binding with Gsp, the side chains of Asn149 and Gln58 of the amidase domain are induced to move closer to the carbonyl oxygen of the cleaved amide bond of Gsp, thereby participating in catalysis. In addition, the helix-loop region of GspA, corresponding to the sequence (30)YSSLDPQEYEDDA(42), involves in regulating the substrate binding. Our previous study indicated that the thiol of Cys59 of GspA is only oxidized to sulfenic acid by H(2)O(2). When comparing the active site of GspA with those of other cysteine proteases, we found that limited space and hydrophobicity of the environment around Cys59 play an important role to inhibit its further oxidation. The structural results presented here not only elucidate the catalytic mechanism and regulation of GspA but also help us to design small molecules to inhibit or probe for the activity of GspA.

  8. The Structure of Allophanate Hydrolase from Granulibacter bethesdensis Provides Insights into Substrate Specificity in the Amidase Signature Family

    SciTech Connect

    Lin, Yi; Maurice, Martin

    2013-01-02

    Allophanate hydrolase (AH) catalyzes the hydrolysis of allophanate, an intermediate in atrazine degradation and urea catabolism pathways, to NH3 and CO2. AH belongs to the amidase signature family, which is characterized by a conserved block of 130 amino acids rich in Gly and Ser and a Ser-cis-Ser-Lys catalytic triad. In this study, the first structures of AH fromGranulibacter bethesdensis were determined, with and without the substrate analogue malonate, to 2.2 and 2.8 Å, respectively. The structures confirm the identity of the catalytic triad residues and reveal an altered dimerization interface that is not conserved in the amidase signature family. The structures also provide insights into previously unrecognized substrate specificity determinants in AH. Two residues, Tyr299 and Arg307, are within hydrogen bonding distance of a carboxylate moiety of malonate. Both Tyr299 and Arg307 were mutated, and the resulting modified enzymes revealed >3 order of magnitude reductions in both catalytic efficiency and substrate stringency. It is proposed that Tyr299 and Arg307 serve to anchor and orient the substrate for attack by the catalytic nucleophile, Ser172. The structure further suggests the presence of a unique C-terminal domain in AH. While this domain is conserved, it does not contribute to catalysis or to the structural integrity of the core domain, suggesting that it may play a role in mediating transient and specific interactions with the urea carboxylase component of urea amidolyase. Analysis of the AH active site architecture offers new insights into common determinants of catalysis and specificity among divergent members of the amidase signature family.

  9. A Metagenomic Study Highlights Phylogenetic Proximity of Quorum-Quenching and Xenobiotic-Degrading Amidases of the AS-Family

    PubMed Central

    Tannières, Mélanie; Beury-Cirou, Amélie; Vigouroux, Armelle; Mondy, Samuel; Pellissier, Franck; Dessaux, Yves; Faure, Denis

    2013-01-01

    Quorum-sensing (QS) signals of the N-acylhomoserine lactone (NAHL) class are cleaved by quorum-quenching enzymes, collectively named NAHLases. Here, functional metagenomics allowed the discovery of a novel bacterial NAHLase in a rhizosphere that was treated with γ-caprolactone. As revealed by rrs-DGGE and rrs-pyrosequencing, this treatment increased the percentage of the NAHL-degrading bacteria and strongly biased the structure of the bacterial community, among which Azospirillum dominated. Among the 29 760 fosmids of the metagenomic library, a single one was detected that expressed the qsdB gene conferring NAHL-degradation upon E. coli and decreased QS-regulated virulence in Pectobacterium. Phylogenetic analysis of the 34 orfs of the fosmid suggested that it would belong to an unknown Proteobacterium - probably a γ-proteobacterium. qPCR quantification of the NAHLase-encoding genes attM, qsdA, and qsdB revealed their higher abundance in the γ-caprolactone-treated rhizosphere as compared to an untreated control. The purified QsdB enzyme exhibited amidase activity. QsdB is the first amidase signature (AS) family member exhibiting NAHLase-activity. Point mutations in the AS-family catalytic triad K-S-S abolished the NAHLase activity of QsdB. This study extends the diversity of NAHLases and highlights a common phylogenic origin of AS-family enzymes involved in the degradation of natural compounds, such as NAHLs, and xenobiotics, such as nylon and linuron. PMID:23762380

  10. Enzyme-substrate binding landscapes in the process of nitrile biodegradation mediated by nitrile hydratase and amidase.

    PubMed

    Zhang, Yu; Zeng, Zhuotong; Zeng, Guangming; Liu, Xuanming; Chen, Ming; Liu, Lifeng; Liu, Zhifeng; Xie, Gengxin

    2013-08-01

    The continuing discharge of nitriles in various industrial processes has caused serious environmental consequences of nitrile pollution. Microorganisms possess several nitrile-degrading pathways by direct interactions of nitriles with nitrile-degrading enzymes. However, these interactions are largely unknown and difficult to experimentally determine but important for interpretation of nitrile metabolisms and design of nitrile-degrading enzymes with better nitrile-converting activity. Here, we undertook a molecular modeling study of enzyme-substrate binding modes in the bi-enzyme pathway for degradation of nitrile to acid. Docking results showed that the top substrates having favorable interactions with nitrile hydratase from Rhodococcus erythropolis AJ270 (ReNHase), nitrile hydratase from Pseudonocardia thermophila JCM 3095 (PtNHase), and amidase from Rhodococcus sp. N-771 (RhAmidase) were benzonitrile, 3-cyanopyridine, and L-methioninamide, respectively. We further analyzed the interactional profiles of these top poses with corresponding enzymes, showing that specific residues within the enzyme's binding pockets formed diverse contacts with substrates. This information on binding landscapes and interactional profiles is of great importance for the design of nitrile-degrading enzyme mutants with better oxidation activity toward nitriles or amides in the process of pollutant treatments.

  11. Development of new inhibitors for N-acylethanolamine-hydrolyzing acid amidase as promising tool against bladder cancer.

    PubMed

    Vago, Riccardo; Bettiga, Arianna; Salonia, Andrea; Ciuffreda, Pierangela; Ottria, Roberta

    2017-02-01

    The endocannabinoid system is a signaling system involved in a wide range of biological effects. Literature strongly suggests the endocannabinoid system role in the pathogenesis of cancer and that its pharmacological activation produces therapeutic benefits. Last research promotes the endocannabinoid system modulation by inhibition of endocannabinoids hydrolytic enzymes instead of direct activation of endocannabinoid receptors to avoid detrimental effects on cognition and motor control. Here we report the identification of N-acylethanolamine-hydrolyzing acid amidase (NAAA) inhibitors able to reduce cell proliferation and migration and cause cell death on different bladder cancer cell lines. These molecules were designed, synthesized and characterized and active compounds were selected by a fluorescence high-throughput screening method set-up on human recombinant NAAA that also allows to characterize the mechanism of inhibition. Together our results suggest an important role for NAAA in cell migration and in inducing tumor cell death promoting this enzyme as pharmacological target against bladder cancer.

  12. A peptidoglycan recognition protein from Sciaenops ocellatus is a zinc amidase and a bactericide with a substrate range limited to Gram-positive bacteria.

    PubMed

    Li, Mo-Fei; Zhang, Min; Wang, Chun-Lin; Sun, Li

    2012-02-01

    Peptidoglycan recognition proteins (PGRPs) are a family of innate immune molecules that recognize bacterial peptidoglycan. PGRPs are highly conserved in invertebrates and vertebrates including fish. However, the biological function of teleost PGRP remains largely uninvestigated. In this study, we identified a PGRP homologue, SoPGLYRP-2, from red drum (Sciaenops ocellatus) and analyzed its activity and potential function. The deduced amino acid sequence of SoPGLYRP-2 is composed of 482 residues and shares 46-94% overall identities with known fish PGRPs. SoPGLYRP-2 contains at the C-terminus a single zinc amidase domain with conserved residues that form the catalytic site. Quantitative RT-PCR analysis detected SoPGLYRP-2 expression in multiple tissues, with the highest expression occurring in liver and the lowest expression occurring in brain. Experimental bacterial infection upregulated SoPGLYRP-2 expression in kidney, spleen, and liver in time-dependent manners. To examine the biological activity of SoPGLYRP-2, purified recombinant proteins representing the intact SoPGLYRP-2 (rSoPGLYRP-2) and the amidase domain (rSoPGLYRP-AD) were prepared from Escherichia coli. Subsequent analysis showed that rSoPGLYRP-2 and rSoPGLYRP-AD (i) exhibited comparable Zn(2+)-dependent peptidoglycan-lytic activity and were able to recognize and bind to live bacterial cells, (ii) possessed bactericidal effect against Gram-positive bacteria and slight bacteriostatic effect against Gram-negative bacteria, (iii) were able to block bacterial infection into host cells. These results indicate that SoPGLYRP-2 is a zinc-dependent amidase and a bactericide that targets preferentially at Gram-positive bacteria, and that SoPGLYRP-2 is likely to play a role in host innate immune defense during bacterial infection.

  13. Resolving the database sequence discrepancies for the Staphylococcus aureus bacteriophage phi 11 amidase.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    There are two conflicting primary nucleotide sequences of the Staphylococcus aureus bacteriophage '11 amidase gene in public databases. Nucleotide sequence differences as well as alternative translational start site assignments result in three non-identical protein sequence predictions in Genbank f...

  14. Structural and Biochemical Analyses of Mycobacterium tuberculosis N-Acetylmuramyl-l-alanine Amidase Rv3717 Point to a Role in Peptidoglycan Fragment Recycling*

    PubMed Central

    Prigozhin, Daniil M.; Mavrici, Daniela; Huizar, John P.; Vansell, Hilary J.; Alber, Tom

    2013-01-01

    Peptidoglycan hydrolases are key enzymes in bacterial cell wall homeostasis. Understanding the substrate specificity and biochemical activity of peptidoglycan hydrolases in Mycobacterium tuberculosis is of special interest as it can aid in the development of new cell wall targeting therapeutics. In this study, we report biochemical and structural characterization of the mycobacterial N-acetylmuramyl-l-alanine amidase, Rv3717. The crystal structure of Rv3717 in complex with a dipeptide product shows that, compared with previously characterized peptidoglycan amidases, the enzyme contains an extra disulfide-bonded β-hairpin adjacent to the active site. The structure of two intermediates in assembly reveal that Zn2+ binding rearranges active site residues, and disulfide formation promotes folding of the β-hairpin. Although Zn2+ is required for hydrolysis of muramyl dipeptide, disulfide oxidation is not required for activity on this substrate. The orientation of the product in the active site suggests a role for a conserved glutamate (Glu-200) in catalysis; mutation of this residue abolishes activity. The product binds at the head of a closed tunnel, and the enzyme showed no activity on polymerized peptidoglycan. These results point to a potential role for Rv3717 in peptidoglycan fragment recycling. PMID:24019530

  15. Increasing plant growth by modulating omega-amidase expression in plants

    DOEpatents

    Unkefer, Pat J.; Anderson, Penelope S.; Knight, Thomas J.

    2015-06-30

    The present disclosure relates to compositions and methods for increasing the leaf-to-root ratio of the signal metabolite 2-oxoglutaramate and related proline molecules in plants by modulating levels of .omega.-amidase to increase nitrogen use efficiency, resulting in enhanced growth, faster growth rates, greater seed and fruit/pod yields, earlier and more productive flowering, increased tolerance to high salt conditions, and increased biomass yields.

  16. Application of protein N-terminal amidase in enzymatic synthesis of dipeptides containing acidic amino acids specifically at the N-terminus.

    PubMed

    Arai, Toshinobu; Noguchi, Atsushi; Takano, Eriko; Kino, Kuniki

    2013-04-01

    Dipeptides exhibit unique physiological functions and physical properties, e.g., l-aspartyl-l-phenylalanine-methyl ester (Asp-Phe-OMe, aspartame) as an artificial sweetener, and functional studies of peptides have been carried out in various fields. Therefore, to establish a manufacturing process for the useful dipeptides, we investigated its enzymatic synthesis by utilizing an l-amino acid ligase (Lal), which catalyzes dipeptide synthesis in an ATP-dependent manner. Many Lals were obtained, but the Lals recognizing acidic amino acids as N-terminal substrates have not been identified. To increase the variety of dipeptides that are enzymatically synthesized, we proposed a two-step synthesis: Asn-Xaa and Gln-Xaa (Asn, l-asparagine; Gln, l-glutamine; and Xaa, arbitrary amino acids) synthesized by Lals were continuously deamidated by a novel amidase, yielding Asp-Xaa and Glu-Xaa (Asp, l-aspartic acid; and Glu, l-glutamic acid). We searched for amidases that specifically deamidate the N-terminus of Asn or Gln in dipeptides since none have been previously reported. We focused on the protein N-terminal amidase from Saccharomyces cerevisiae (NTA1), and assayed its activity toward dipeptides. Our findings showed that NTA1 deamidated l-asparaginyl-l-valine (Asn-Val) and l-glutaminyl-glycine (Gln-Gly), but did not deamidate l-valyl-l-asparagine and l-alanyl-l-glutamine, suggesting that this deamidation activity is N-terminus specific. The specific activity toward Asn-Val and Gln-Gly were 190 ± 30 nmol min(-1) mg(-1)·protein and 136 ± 6 nmol min(-1) mg(-1)·protein. Additionally, we examined some characteristics of NTA1. Acidic dipeptide synthesis was examined by a combination of Lals and NTA1, resulting in the synthesis of 12 kinds of Asp-Xaa, including Asp-Phe, a precursor of aspartame, and 11 kinds of Glu-Xaa.

  17. Effect of the increased stability of the penicillin amidase mRNA on the protein expression levels.

    PubMed

    Viegas, Sandra C; Schmidt, Dorothea; Kasche, Volker; Arraiano, Cecília M; Ignatova, Zoya

    2005-09-12

    Several factors at transcriptional, post-transcriptional or post-translational level determine the fate of a target protein and can severely restrict its yield. Here, we focus on the post-transcriptional regulation of the biosynthesis of the periplasmic protein, penicillin amidase (PA). The PA mRNA stability was determined under depleted RNase conditions in strains carrying single or multiple RNase deletions. Single deletion of the endonuclease RNase E yielded, as the highest, a fourfold stabilization of the PA mRNA. This effect, however, was reduced twice at post-translational level. The RNase II, generating secondary exonucleolytic cleavages in the mRNA, although not significantly influencing the PA mRNA decay, led also to an increase of the amount of mature PA. The non-proportional correlation between increased mRNA longevity and amount of active enzyme propose that the rational strategies for yield improvement must be based on a simultaneous tuning of more than one yield restricting factor.

  18. Acrosin-binding protein (ACRBP) and triosephosphate isomerase (TPI) are good markers to predict boar sperm freezing capacity.

    PubMed

    Vilagran, Ingrid; Castillo, Judit; Bonet, Sergi; Sancho, Sílvia; Yeste, Marc; Estanyol, Josep M; Oliva, Rafael

    2013-09-15

    Sperm cryopreservation is the most efficient method for storing boar sperm samples for a long time. However, one of the inconveniences of this method is the large variation between and within boars in the cryopreservation success of their sperm. The aim of the present work was thus to find reliable and useful predictive biomarkers of the good and poor capacity to withstand the freeze-thawing process in boar ejaculates. To find these biomarkers, the amount of proteins present in the total proteome in sperm cells were compared between good freezability ejaculates (GFE) and poor freezability ejaculates (PFE) using the two-dimensional difference gel electrophoresis technique. Samples were classified as GFE and PFE using progressive motility and viability of the sperm at 30 and 240 minutes after thawing, and the proteomes from each group, before starting cryopreservation protocols, were compared. Because two proteins, acrosin binding protein (ACRBP) and triosephosphate isomerase (TPI), presented the highest significant differences between GFE and PFE groups in two-dimensional difference gel electrophoresis assessment, Western blot analyses for ACRBP and TPI were also performed for validation. ACRBP normalized content was significantly lower in PFE than in GFE (P < 0.05), whereas the TPI amounts were significantly lower in GFE (P < 0.05) than in PFE. The association of ACRBP and TPI with postthaw sperm viability and motility was confirmed using Pearson's linear correlation. In conclusion, ACRBP and TPI can be used as markers of boar sperm freezability before starting the cryopreservation procedure, thereby avoiding unnecessary costs involved in this practice.

  19. Functional and structural analysis of the major amidase (Atl) in Staphylococcus.

    PubMed

    Götz, Friedrich; Heilmann, Christine; Stehle, Thilo

    2014-03-01

    The cytoplasmic membrane of most bacteria is surrounded by a more or less thick murein layer (peptidoglycan) that protects the protoplast from mechanical damage, osmotic rupture and lysis. When bacteria are dividing processes are initiated stepwise that involve DNA replication, constriction of the membranes, cell growth, biosynthesis of new murein, and finally the generation of two daughter cells. As the daughter cells are still covalently interlinked by the murein network they must be separated by specific peptidoglycan hydrolases, also referred to as autolysins. In staphylococci, the major autolysin (Atl) and its processed products N-acetylmuramoyl-l-alanine amidase (AM) and endo-β-N-acetylglucosaminidase (GL) have been in the research focus for long time. This review addresses phenotypic consequences of atl mutants, impact of Atl in virulence, the mechanism of targeting to the septum region, regulation of atl, the structure of the amidase and the repeat regions, as well as the phylogeny of Atl and its use in Staphylococcus genus and species typing.

  20. Identification and characterization of a thermostable and cobalt-dependent amidase from Burkholderia phytofirmans ZJB-15079 for efficient synthesis of (R)-3,3,3-trifluoro-2-hydroxy-2-methylpropionic acid.

    PubMed

    Wu, Zhe-Ming; Zheng, Ren-Chao; Tang, Xiao-Ling; Zheng, Yu-Guo

    2017-03-01

    Enantiomerically pure 3,3,3-trifluoro-2-hydroxy-2-methylpropionic acids are important chiral building blocks for a series of pharmaceuticals. Here, a bacteria strain with 3,3,3-trifluoro-2-hydroxy-2-methylpropanamide-degrading ability was screened and identified as Burkholderia phytofirmans ZJB-15079, from which a novel amidase (Bp-Ami) was cloned and demonstrated to be capable of kinetic resolution of rac-3,3,3-trifluoro-2-hydroxy-2-methylpropanamide to optically pure (R)-3,3,3-trifluoro-2-hydroxy-2-methylpropionic acid. Phylogenetic analysis revealed that Bp-Ami was closely located to the acetamidase/formamidase (FmdA_AmdA) family, and it shared high homology with acetamidases. Bp-Ami was found to be the first cobalt-dependent FmdA_AmdA family amidase. The enzyme activity was significantly increased by 37.7-fold in the presence of 1 mM Co(2+), with a specific activity of 753.5 U/mg, K m value of 24.73 mM, and k cat /K m value of 22.47 mM(-1) s(-1). As an enzyme from mesophile, Bp-Ami exhibited extreme thermostability with a half-life of 47.93 h at 80 °C, which was even superior to other reported amidases from thermophiles. The whole cell catalysis of 200 g/L 3,3,3-trifluoro-2-hydroxy-2-methylpropanamide by Escherichia coli harboring Bp-Ami (5 g/L) resulted in 44 % yield and an enantiomeric excess (ee p) of 95 % within 10 min (E = 86). The high substrate tolerance, high specific activity, and extreme thermostability demonstrated the great potential of Bp-Ami for efficient biocatalytic synthesis of (R)-3,3,3-trifluoro-2-hydroxy-2-methylpropionic acid.

  1. Pleiotropic Effects of Cell Wall Amidase LytA on Streptococcus pneumoniae Sensitivity to the Host Immune Response

    PubMed Central

    Ramos-Sevillano, Elisa; Urzainqui, Ana; Campuzano, Susana; Moscoso, Miriam; González-Camacho, Fernando; Domenech, Mirian; Rodríguez de Córdoba, Santiago; Sánchez-Madrid, Francisco; Brown, Jeremy S.; García, Ernesto

    2014-01-01

    The complement system is a key component of the host immune response for the recognition and clearance of Streptococcus pneumoniae. In this study, we demonstrate that the amidase LytA, the main pneumococcal autolysin, inhibits complement-mediated immunity independently of effects on pneumolysin by a complex process of impaired complement activation, increased binding of complement regulators, and direct degradation of complement C3. The use of human sera depleted of either C1q or factor B confirmed that LytA prevented activation of both the classical and alternative pathways, whereas pneumolysin inhibited only the classical pathway. LytA prevented binding of C1q and the acute-phase protein C-reactive protein to S. pneumoniae, thereby reducing activation of the classical pathway on the bacterial surface. In addition, LytA increased recruitment of the complement downregulators C4BP and factor H to the pneumococcal cell wall and directly cleaved C3b and iC3b to generate degradation products. As a consequence, C3b deposition and phagocytosis increased in the absence of LytA and were markedly enhanced for the lytA ply double mutant, confirming that a combination of LytA and Ply is essential for the establishment of pneumococcal pneumonia and sepsis in a murine model of infection. These data demonstrate that LytA has pleiotropic effects on complement activation, a finding which, in combination with the effects of pneumolysin on complement to assist with pneumococcal complement evasion, confirms a major role of both proteins for the full virulence of the microorganism during septicemia. PMID:25404032

  2. Characterization of an inducible amidase from Pseudomonas acidovorans AE1.

    PubMed

    Alt, J; Heymann, E; Krisch, K

    1975-05-06

    The main molecular and catalytic properties of an acetanilide-hydrolyzing enzyme from Pseudomonas acidovorans AE 1, purified to a homogeneous state, were investigated. The molecular weight was 57 500 as determined by gel filtration and 55 300 as computed from the amino acid composition. By polyacrylamide gel electrophoresis in dodecylsulfate a polypeptide chain weight of 56 700 was obtained. Based on the reaction of the highly purufied enzyme with diethyl-4-nitrophenyl phosphate an equivalent weight of approximately 59 100 was found. From these results it was concluded that the enzyme consists of a single polypeptide chain and contains one active site per molecule. The enzyme hydrolyzed esters as well as certain aromatic amides. It also catalysed the transfer of acetyl groups to phenetidine yielding phenacetin. The activities towards aliphatic esters were much smaller. The enzyme was stable at pH values ranging from 7 to 9 and its pH-optimum was about 10. It was strongly inhibited by organophosphorous compounds, like diethyl-4-nitrophenyl phosphate or diisopropylphosphorofluoridate, as well as by physostigmine sulfate and -SH-blocking reagents, like HgCl-2 or 4-chloromercuribenzoic acid. o-Nitrophenol caused a competitive inhibition and phenetidine an uncompetitive inhibition.

  3. Potential analgesic effects of a novel N-acylethanolamine acid amidase inhibitor F96 through PPAR-α

    PubMed Central

    Yang, Longhe; Li, Long; Chen, Ling; Li, Yanting; Chen, Huixia; Li, Yuhang; Ji, Guangnian; Lin, Donghai; Liu, Zuguo; Qiu, Yan

    2015-01-01

    Pharmacological blockade of N-acylethanolamine acid amidase (NAAA) activity is an available approach for inflammation and pain control through restoring the ability of endogenous PEA. But the recently reported NAAA inhibitors suffer from the chemical and biological unstable properties, which restrict functions of NAAA inhibition in vivo. It is still unrevealed whether systematic inhibition of NAAA could modulate PEA-mediated pain signalings. Here we reported an oxazolidinone imide compound 3-(6-phenylhexanoyl) oxazolidin-2-one (F96), which potently and selectively inhibited NAAA activity (IC50 = 270 nM). Intraperitoneal (i.p.) injection of F96 (3–30 mg/kg) dose-dependently reduced ear edema and restored PEA levels of ear tissues in 12-O-Tetradecanoylphorbol-13-acetate (TPA) induced ear edema models. Furthermore, F96 inhibited acetic acid-induced writhing and increased spared nerve injury induced tactile allodynia thresholds in a dose-dependent manner. Pharmacological effects of F96 (10 mg/kg, i.p.) on various animal models were abolished in PPAR-α−/− mice, and were prevented by PPAR-α antagonist MK886 but not by canabinoid receptor type 1 (CB1) antagonist Rimonabant nor canabinoid receptor type 2 (CB2) antagonist SR144528. Zebrafish embryos experiments showed better security and lower toxicity for F96 than ibuprofen. These results revealed that F96 might be useful in treating inflammatory and neuropathic pain by NAAA inhibition depending on PPAR-α receptors. PMID:26310614

  4. The aliphatic amidase AmiE is involved in regulation of Pseudomonas aeruginosa virulence

    PubMed Central

    Clamens, Thomas; Rosay, Thibaut; Crépin, Alexandre; Grandjean, Teddy; Kentache, Takfarinas; Hardouin, Julie; Bortolotti, Perrine; Neidig, Anke; Mooij, Marlies; Hillion, Mélanie; Vieillard, Julien; Cosette, Pascal; Overhage, Joerg; O’Gara, Fergal; Bouffartigues, Emeline; Dufour, Alain; Chevalier, Sylvie; Guery, Benoit; Cornelis, Pierre; Feuilloley, Marc G. J.; Lesouhaitier, Olivier

    2017-01-01

    We have previously shown that the eukaryotic C-type natriuretic peptide hormone (CNP) regulates Pseudomonas aeruginosa virulence and biofilm formation after binding on the AmiC sensor, triggering the amiE transcription. Herein, the involvement of the aliphatic amidase AmiE in P. aeruginosa virulence regulation has been investigated. The proteome analysis of an AmiE over-producing strain (AmiE+) revealed an expression change for 138 proteins, including some that are involved in motility, synthesis of quorum sensing compounds and virulence regulation. We observed that the AmiE+ strain produced less biofilm compared to the wild type, and over-produced rhamnolipids. In the same line, AmiE is involved in P. aeruginosa motilities (swarming and twitching) and production of the quorum sensing molecules N-acyl homoserine lactones and Pseudomonas Quinolone Signal (PQS). We observed that AmiE overproduction reduced levels of HCN and pyocyanin causing a decreased virulence in different hosts (i.e. Dictyostelium discoideum and Caenorhabditis elegans). This phenotype was further confirmed in a mouse model of acute lung infection, in which AmiE overproduction resulted in an almost fully virulence decrease. Taken together, our data suggest that, in addition to its role in bacterial secondary metabolism, AmiE is involved in P. aeruginosa virulence regulation by modulating pilus synthesis and cell-to-cell communication. PMID:28117457

  5. Amidase, a cell wall hydrolase, elicits protective immunity against Staphylococcus aureus and S. epidermidis.

    PubMed

    Nair, Nisha; Vinod, Vivek; Suresh, Maneesha K; Vijayrajratnam, Sukhithasri; Biswas, Lalitha; Peethambaran, Reshmi; Vasudevan, Anil Kumar; Biswas, Raja

    2015-01-01

    The morbidity and the mortality associated with Staphylococcus aureus and S. epidermidis infections have greatly increased due to the rapid emergence of highly virulent and antibiotic resistant strains. Development of a vaccine-based therapy is greatly desired. However, no staphylococcal vaccine is available till date. In this study, we have identified Major amidase (Atl-AM) as a prime candidate for future vaccine design against these pathogens. Atl-AM is a multi-functional non-covalently cell wall associated protein which is involved in staphylococcal cell separation after cell division, host extracellular matrix adhesion and biofilm formation. Atl-AM is present on the surface of diverse S. aureus and S. epidermidis strains. When used in combination with Freund's adjuvant, Atl-AM generated a mixed Th1 and Th2 mediated immune response which is skewed more toward Th1; and showed increased production of opsonophagocytic IgG2a and IgG2b antibodies. Significant protective immune response was observed when vaccinated mice were challenged with S. aureus or S. epidermidis. Vaccination prevented the systemic dissemination of both organisms. Our results demonstrate the remarkable efficacy of Atl-AM as a vaccine candidate against both of these pathogens.

  6. Identity of cofactor bound to mycothiol conjugate amidase (Mca) influenced by expression and purification conditions.

    PubMed

    Kocabas, Evren; Liu, Hualan; Hernick, Marcy

    2015-08-01

    Mycothiol serves as the primary reducing agent in Mycobacterium species, and is also a cofactor for the detoxification of xenobiotics. Mycothiol conjugate amidase (Mca) is a metalloamidase that catalyzes the cleavage of MS-conjugates to form a mercapturic acid, which is excreted from the mycobacterium, and 1-D-myo-inosityl-2-amino-2-deoxy-α-D-glucopyranoside. Herein we report on the metal cofactor preferences of Mca from Mycobacterium smegmatis and Mycobacterium tuberculosis. Importantly, results from homology models of Mca from M. smegmatis and M. tuberculosis suggest that the metal binding site of Mca is identical to that of the closely related protein N-acetyl-1-D-myo-inosityl-2-amino-2-deoxy-α-D-glucopyranoside deacetylase (MshB). This finding is supported by results from zinc ion affinity measurements that indicate Mca and MshB have comparable K(D)(ZnII) values (~10-20 pM). Furthermore, results from pull-down experiments using Halo-Mca indicate that Mca purifies with (stoichiometric) Fe(2+) when purified under anaerobic conditions, and Zn(2+) when purified under aerobic conditions. Consequently, Mca is likely a Fe(2+)-dependent enzyme under physiological conditions; with Zn(2+)-Mca an experimental artifact that could become biologically relevant under oxidatively stressed conditions. Importantly, these findings suggest that efforts towards the design of Mca inhibitors should include targeting the Fe(2+) form of the enzyme.

  7. Crystal Structure of Murein-Tripeptide Amidase MpaA from Escherichia coli O157 at 2.6 Å Resolution.

    PubMed

    Ma, Yinliang; Bai, Guohui; Cui, Yaqi; Zhao, Jing; Yuan, Zenglin; Liu, Xiuhua

    2017-01-01

    Peptidoglycan (PG) is an essential component of the cell wall, and undergoes reconstruction by various PG hydrolases during cell growth, development and division. The murein- tripeptide (Mtp) amidase MpaA belongs to PG hydrolase family and is responsible for cleaving the γ-D-Glumeso- Dap amide bond in the Mtp released during PG turnover. The current paper reports the crystal structure of MpaA from Escherichia coli (E. coli) O157 at 2.6 Å resolution. The asymmetric unit consists of two protein molecules and each monomer represents the common α/β fold of metallocarboxypeptidases (MCP). The Tyr133-Asp143 loop appears to mediate the entrance and binding of the substrate into the active groove. A structural comparison of MpaA with its homologue from Vibrio harveyi showed that MpaA has narrower active pocket entrance with a smaller surface opening, which is determined by the Val204-Thr211 loop. The reported structure provides a starting point for the molecular mechanism of MpaA in a significant human pathogen.

  8. X-Ray Structure of the Amidase Domain of AtzF, the Allophanate Hydrolase from the Cyanuric Acid-Mineralizing Multienzyme Complex

    PubMed Central

    Balotra, Sahil; Newman, Janet; Cowieson, Nathan P.; French, Nigel G.; Campbell, Peter M.; Briggs, Lyndall J.; Warden, Andrew C.; Easton, Christopher J.; Peat, Thomas S.

    2014-01-01

    The activity of the allophanate hydrolase from Pseudomonas sp. strain ADP, AtzF, provides the final hydrolytic step for the mineralization of s-triazines, such as atrazine and cyanuric acid. Indeed, the action of AtzF provides metabolic access to two of the three nitrogens in each triazine ring. The X-ray structure of the N-terminal amidase domain of AtzF reveals that it is highly homologous to allophanate hydrolases involved in a different catabolic process in other organisms (i.e., the mineralization of urea). The smaller C-terminal domain does not appear to have a physiologically relevant catalytic function, as reported for the allophanate hydrolase of Kluyveromyces lactis, when purified enzyme was tested in vitro. However, the C-terminal domain does have a function in coordinating the quaternary structure of AtzF. Interestingly, we also show that AtzF forms a large, ca. 660-kDa, multienzyme complex with AtzD and AtzE that is capable of mineralizing cyanuric acid. The function of this complex may be to channel substrates from one active site to the next, effectively protecting unstable metabolites, such as allophanate, from solvent-mediated decarboxylation to a dead-end metabolic product. PMID:25362066

  9. 3–Aminoazetidin–2–one Derivatives as N–Acylethanolamine Acid Amidase (NAAA) Inhibitors Suitable for Systemic Administration

    PubMed Central

    Fiasella, Annalisa; Nuzzi, Andrea; Summa, Maria; Armirotti, Andrea; Tarozzo, Glauco; Tarzia, Giorgio; Mor, Marco; Bertozzi, Fabio; Bandiera, Tiziano; Piomelli, Daniele

    2014-01-01

    N Acylethanolamine acid amidase (NAAA) is a cysteine hydrolase that catalyzes the hydrolysis of endogenous lipid mediators such as palmitoylethanolamide (PEA). PEA has been shown to exert anti–inflammatory and antinociceptive effects in animals by engaging peroxisome proliferator–activated receptor–α (PPAR–α). Thus preventing PEA degradation by inhibiting NAAA may provide a novel approach for the treatment of pain and inflammatory states. Recently, 3–aminooxetan–2–one compounds were identified as a class of highly potent NAAA inhibitors. The utility of these compounds is limited, however, by their low chemical and plasma stabilities. In the present study, we synthesized and tested a series of N–(2–oxoazetidin–3–yl)amides as a novel class of NAAA inhibitors with good potency and improved physicochemical properties, suitable for systemic administration. Moreover, we elucidated the main structural features of 3–aminoazetidin–2–one derivatives that are critical for NAAA inhibition. PMID:24828120

  10. Improved penicillin amidase production using a genetically engineered mutant of escherichia coli ATCC 11105

    SciTech Connect

    Robas, N.; Zouheiry, H.; Branlant, G.; Branlant, C. )

    1993-01-05

    Penicillin G amidase (PGA) is a key enzyme for the industrial production of penicillin G derivatives used in therapeutics. Escherichia coli ATCC 11105 is the more commonly used strain for PGA production. To improve enzyme yield, the authors constructed various recombinant E. coli HB 101 and ATCC 11105 strains. For each strain, PGA production was determined for various concentrations of glucose and phenylacetic acid (PAA) in the medium. The E. coli strain, G271, was identified as the best performer (800 U NIPAB/L). This strain was obtained as follows: an E. coli ATCC 11105 mutant (E. coli G133) was first selected based on a low negative effect of glucose on PGA production. This mutant was then transformed with a pBR322 derivative containing the PGA gene. Various experiments were made to try to understand the reason for the high productivity of E. coli G271. The host strain, E. coli G133, was found to be mutated in one (or more) gene(s) whose product(s) act(s) in trans on the PGA gene expression. Its growth is not inhibited by high glucose concentration in the medium. Interestingly, whereas glucose still exerts some negative effect on the PGA production by E. coli G133, PGA production by its transformant (E. coli G271) is stimulated by glucose. The reason for this stimulation is discussed. Transformation of E. coli G133 with a pBR322 derivative containing the HindIII fragment of the PGA gene, showed that the performance of E. coli G271 depends both upon the host strain properties and the plasmid structure. Study of the production by the less efficient E. coli HB101 derivatives brought some light on the mechanism of regulation of the PGA gene.

  11. Human Tissue Kallikrein Activity in Angiographically Documented Chronic Stable Coronary Artery Disease

    PubMed Central

    Figueiredo, Estêvão Lanna; Magalhães, Carolina Antunes; Belli, Karlyse Claudino; Mandil, Ari; Garcia, José Carlos Faria; Araújo, Rosanã Aparecida; Figueiredo, Amintas Fabiano de Souza; Pellanda, Lucia Campos

    2015-01-01

    Background Human tissue kallikrein (hK1) is a key enzyme in the kallikrein–kinin system (KKS). hK1-specific amidase activity is reduced in urine samples from hypertensive and heart failure (HF) patients. The pathophysiologic role of hK1 in coronary artery disease (CAD) remains unclear. Objective To evaluate hK1-specific amidase activity in the urine of CAD patients Methods Sixty-five individuals (18–75 years) who underwent cardiac catheterism (CATH) were included. Random midstream urine samples were collected immediately before CATH. Patients were classified in two groups according to the presence of coronary lesions: CAD (43 patients) and non-CAD (22 patients). hK1 amidase activity was estimated using the chromogenic substrate D-Val-Leu-Arg-Nan. Creatinine was determined using Jaffé’s method. Urinary hK1-specific amidase activity was expressed as µM/(min · mg creatinine) to correct for differences in urine flow rates. Results Urinary hK1-specific amidase activity levels were similar between CAD [0.146 µM/(min ·mg creatinine)] and non-CAD [0.189 µM/(min . mg creatinine)] patients (p = 0.803) and remained similar to values previously reported for hypertensive patients [0.210 µM/(min . mg creatinine)] and HF patients [0.104 µM/(min . mg creatinine)]. CAD severity and hypertension were not observed to significantly affect urinary hK1-specific amidase activity. Conclusion CAD patients had low levels of urinary hK1-specific amidase activity, suggesting that renal KKS activity may be reduced in patients with this disease. PMID:26351984

  12. Comparison of methods for detecting mitomycin C- and ethyl nitrosourea-induced germ cell damage in mice: sperm enzyme activities, sperm motility, and testis weight

    SciTech Connect

    Ficsor, G.; Oldford, G.M.; Loughlin, K.R.; Panda, B.B.; Dubien, J.L.; Ginsberg, L.C.

    1984-01-01

    Testes weights, sperm motility and enzyme activities in single sperm were compared with respect to their ability to detect either developmental or mutational damage to germ cells. Male mice were injected i.p. with 2.5 mg/kg mitomycin C (MC) or 50 or 100 mg/kg ethylnitrosourea (ENU) or saline and were then killed at times such that sperm derived from treated vas sperm (SZ), spermatids (ST), preleptotene-late-spermatogonial cells (PLSG), spermatogonial cells (SG), or spermatogonial stem cells (SGS) could be evaluated. The authors conclude that testis weight, which is easily obtained, is a sensitive indicator of germ cell damage by these agents. Sperm from each animal were evaluated for sperm motility, acrosin activity, succinic dehydrogenase (SDH) activity with or without the competitive inhibitor malonate or after exposure to 60/sup 8/C for 10 min. The latter two assays were to detect sperm enzymes resistant to the inhibitor or heat. The presence of the acrosin protein was also detected immunologically. Of the sperm assays, acrosin activity proved to be the most sensitive indicator of germ cell damage and was the simplest to measure.

  13. Inefficient Tat-dependent export of periplasmic amidases in an Escherichia coli strain with mutations in two DedA family genes.

    PubMed

    Sikdar, Rakesh; Doerrler, William T

    2010-02-01

    The DedA family genes are found in most bacterial genomes. Two of these proteins are Escherichia coli YqjA and YghB, predicted inner membrane proteins of unknown function sharing 61% amino acid identity. The E. coli single deletion mutants are largely without phenotype, but the double mutant (BC202; Delta yqjA::Tet(r) Delta yghB::Kan(r)) is characterized by incomplete cell division, temperature sensitivity, and altered phospholipid levels (K. Thompkins et al., J. Bacteriol. 190:4489-4500, 2008). In this report, we have better characterized the cell division chaining defect of BC202. Fluorescence recovery after photobleaching indicates that 58% of the cells in chains are compartmentalized by at least a cytoplasmic membrane. Green fluorescent protein fusions to the cell division proteins FtsZ, ZipA, FtsI, FtsL, and FtsQ are correctly localized to new septation sites in BC202. Periplasmic amidases AmiC and AmiA, secreted by the twin arginine transport (Tat) pathway, are localized to the cytoplasm in BC202. Overexpression of AmiA, AmiC, or AmiB, a periplasmic amidase secreted via the general secretory pathway, restores normal cell division but does not suppress the temperature sensitivity of BC202, indicating that YghB and YqjA may play additional roles in cellular physiology. Strikingly, overexpression of the Tat export machinery (TatABC) results in normal cell division and growth at elevated temperatures. These data collectively suggest that the twin arginine pathway functions inefficiently in BC202, likely due to the altered levels of membrane phospholipids in this mutant. These results underscore the importance of membrane composition in the proper function of the Tat protein export pathway.

  14. Probing the Ser-Ser-Lys catalytic triad mechanism of peptide amidase: computational studies of the ground state, transition state, and intermediate.

    PubMed

    Valiña, Anna Liza B; Mazumder-Shivakumar, Devleena; Bruice, Thomas C

    2004-12-21

    Peptide amidase (Pam), a hydrolytic enzyme that belongs to the amidase signature (AS) family, selectively catalyzes the hydrolysis of the C-terminal amide bond (CO-NH(2)) of peptides. The recent availability of the X-ray structures of Pam, fatty acid amide hydrolase, and malonamidase E2 has led to the proposal of a novel Ser-Ser-Lys catalytic triad mechanism for the amide hydrolysis by the AS enzymes. The molecular dynamics (MD) simulations using the CHARMM force field were performed to explore the catalytic mechanism of Pam. The 1.8 A X-ray crystal structure of Pam in complex with the amide analogue of chymostatin was chosen for the initial coordinates for the MD simulations. The five systems that were investigated are as follows: (i) enzyme.substrate with Lys123-NH(2), (ii) enzyme.substrate with Lys123-NH(3)(+), (iii) enzyme.substrate with Lys123-NH(3)(+) and Ser226-O(-), (iv) enzyme.transition state, and (v) enzyme.tetrahedral intermediate. Our data support the presence of the hydrogen bonding network among the catalytic triad residues, Ser226, Ser202, and Lys123, where Ser226 acts as the nucleophile and Ser202 bridges Ser226 and Lys123. The MD simulation supports the catalytic role of the crystallographic waters, Wat1 and Wat2. In all the systems that have been studied, the backbone amide nitrogens of Asp224 and Thr223 create an oxyanion hole by hydrogen bonding to the terminal amide oxygen of the substrate, and stabilize the oxyanion tetrahedral intermediate. The results from both our computational investigation and previously published experimental pH profile support two mechanisms. In a mechanism that is relevant at lower pH, the Lys123-NH(3)(+)-Ser202 dyad provides structural support to the catalytic residue Ser226, which in turn carries out a nucleophilic attack at the substrate amide carbonyl in concert with Wat1-mediated deprotonation and stabilization of the tetrahedral transition state by the oxyanion hole. In the mechanism operating at higher pH, the

  15. Pro-sequence and Ca2+-binding: implications for folding and maturation of Ntn-hydrolase penicillin amidase from E. coli.

    PubMed

    Ignatova, Zoya; Wischnewski, Frank; Notbohm, Holger; Kasche, Volker

    2005-05-13

    Penicillin amidase (PA) is a bacterial periplasmic enzyme synthesized as a pre-pro-PA precursor. The pre-sequence mediates membrane translocation. The intramolecular pro-sequence is expressed along with the A and B chains but is rapidly removed in an autocatalytic manner. In extensive studies we show here that the pro-peptide is required for the correct folding of PA. Pro-PA and PA unfold via a biphasic transition that is more pronounced in the case of PA. According to size-exclusion chromatography and limited proteolysis experiments, the inflection observed in the equilibrium unfolding curves corresponds to an intermediate in which the N-terminal domain (A-chain) still possesses native-like topology, whereas the B-chain is unfolded to a large extent. In a series of in vitro experiments with a slow processing mutant pro-PA, we show that the pro-sequence in cis functions as a folding catalyst and accelerates the folding rate by seven orders of magnitude. In the absence of the pro-domain the PA refolds to a stable inactive molten globule intermediate that has native-like secondary but little tertiary structure. The pro-sequence of the homologous Alcaligenes faecalis PA can facilitate the folding of the hydrolase domain of Escherichia coli PA when added in trans (as a separate polypeptide chain). The isolated pro-sequence has a random structure in solution. However, difference circular dichroism spectra of native PA and native PA with pro-peptide added in trans suggest that the pro-sequence adopts an alpha-helical conformation in the context of the mature PA molecule. Furthermore, our results establish that Ca2+, found in the crystal structure, is not directly involved in the folding process. The cation shifts the equilibrium towards the native state and facilitates the autocatalytic processing of the pro-peptide.

  16. Role of the N-Acetylmuramoyl-l-Alanyl Amidase, AmiA, of Helicobacter pylori in Peptidoglycan Metabolism, Daughter Cell Separation, and Virulence

    PubMed Central

    Chaput, Catherine; Ecobichon, Chantal; Pouradier, Nadine; Rousselle, Jean-Claude; Namane, Abdelkader

    2016-01-01

    The human gastric pathogen, Helicobacter pylori, is becoming increasingly resistant to most available antibiotics. Peptidoglycan (PG) metabolism is essential to eubacteria, hence, an excellent target for the development of new therapeutic strategies. However, our knowledge on PG metabolism in H. pylori remains poor. We have further characterized an isogenic mutant of the amiA gene encoding a N-acetylmuramoyl-l-alanyl amidase. The amiA mutant displayed long chains of unseparated cells, an impaired motility despite the presence of intact flagella and a tolerance to amoxicillin. Interestingly, the amiA mutant was impaired in colonizing the mouse stomach suggesting that AmiA is a valid target in H. pylori for the development of new antibiotics. Using reverse phase high-pressure liquid chromatography, we analyzed the PG muropeptide composition and glycan chain length distribution of strain 26695 and its amiA mutant. The analysis showed that H. pylori lacked muropeptides with a degree of cross-linking higher than dimeric muropeptides. The amiA mutant was also characterized by a decrease of muropeptides carrying 1,6-anhydro-N-acetylmuramic acid residues, which represent the ends of the glycan chains. This correlated with an increase of very long glycan strands in the amiA mutant. It is suggested that these longer glycan strands are trademarks of the division site. Taken together, we show that the low redundancy on genes involved in PG maturation supports H. pylori as an actractive alternative model to study PG metabolism and cell shape regulation. PMID:27447281

  17. Activation of proacrosin accompanies upregulation of sp32 protein tyrosine phosphorylation in pig sperm.

    PubMed

    Sun, P L; Yang, L X; Cui, J-J; Tian, Y; Liu, Y; Jin, Y

    2013-12-11

    This study investigated the relationship between acrosin activation and pig sperm proacrosin binding protein (sp32) phosphorylation levels. Differently processed pig spermatozoa (fresh semen sperm, capacitation sperm, acrosome reaction sperm, capacitation-like sperm, and thawed sperm) were subjected to sodium dodecyl sulfate polyacrylamide gel electrophoresis and Western blot analysis. The fresh semen and capacitation sperm groups both produced proacrosin protein bands of 55 kDa; however, the result of the fresh semen sperm group was clearer than that of the capacitation sperm group. The thawed sperm group showed a shallow strip at 55 kDa. The capacitation and acrosome reaction sperm groups produced obvious proacrosin protein bands at 35 kDa, and the strips of the capacitation sperm group were again clearer. A faint band was visible at 32 kDa in the acrosome reaction sperm group. The capacitation, thawed, and acrosome reaction sperm groups showed significant strips in sp32, and the bands of the acrosome reaction sperm group were shallower than those of the 2 other groups. The capacitation and thawed sperm groups produced significant strips at 40 kDa, and the capacitation sperm group produced an additional strip at 55 kDa. In conclusion, sp32 phosphorylation levels can promote proacrosin activation into the active acrosin.

  18. Activity of n-propyl pyrazinoate against pyrazinamide-resistant Mycobacterium tuberculosis: investigations into mechanism of action of and mechanism of resistance to pyrazinamide.

    PubMed

    Speirs, R J; Welch, J T; Cynamon, M H

    1995-06-01

    The mechanism of action of pyrazinamide (PZA) is not known. One hypothesis is that PZA functions as a prodrug of pyrazinoic acid. Susceptibility to PZA correlates with amidase activity of the Mycobacterium tuberculosis isolate in question. PZA-resistant isolates retain susceptibility in vitro to pyrazinoic acid and n-propyl pyrazinoate. Esters of pyrazinoic acid appear to circumvent the requirement for activation by mycobacterial amidase. The MICs of n-propyl pyrazinoate for M. tuberculosis isolates are lower than those of pyrazinoic acid. Further studies to assess the effects of modifications of the alcohol and pyrazine moieties of pyrazinoate esters on in vitro and in vivo antituberculosis activity are under way. This may lead to a candidate compound with enhanced activity against both PZA-susceptible and PZA-resistant M. tuberculosis isolates suitable for clinical development.

  19. AmiA is a penicillin target enzyme with dual activity in the intracellular pathogen Chlamydia pneumoniae

    PubMed Central

    Klöckner, Anna; Otten, Christian; Derouaux, Adeline; Vollmer, Waldemar; Bühl, Henrike; De Benedetti, Stefania; Münch, Daniela; Josten, Michaele; Mölleken, Katja; Sahl, Hans-Georg; Henrichfreise, Beate

    2014-01-01

    Intracellular Chlamydiaceae do not need to resist osmotic challenges and a functional cell wall was not detected in these pathogens. Nevertheless, a recent study revealed evidence for circular peptidoglycan-like structures in Chlamydiaceae and penicillin inhibits cytokinesis, a phenomenon known as the chlamydial anomaly. Here, by characterizing a cell wall precursor-processing enzyme, we provide insights into the mechanisms underlying this mystery. We show that AmiA from Chlamydia pneumoniae separates daughter cells in an Escherichia coli amidase mutant. Contrary to homologues from free-living bacteria, chlamydial AmiA uses lipid II as a substrate and has dual activity, acting as an amidase and a carboxypeptidase. The latter function is penicillin sensitive and assigned to a penicillin-binding protein motif. Consistent with the lack of a regulatory domain in AmiA, chlamydial CPn0902, annotated as NlpD, is a carboxypeptidase, rather than an amidase activator, which is the case for E. coli NlpD. Functional conservation of AmiA implicates a role in cytokinesis and host response modulation. PMID:24953137

  20. Thin-Layer Polymer Wrapped Enzymes Encapsulated in Hierarchically Mesoporous Silica with High Activity and Enhanced Stability

    NASA Astrophysics Data System (ADS)

    Zhang, Fang; Wang, Meitao; Liang, Chao; Jiang, Huangyong; Shen, Jian; Li, Hexing

    2014-03-01

    A novel soft-hard cooperative approach was developed to synthesize bioactive mesoporous composite by pre-wrapping Penicillin G amidase with poly(acrylaimde) nanogel skin and subsequently incorporating such Penicillin G amidase nanocapsules into hierarchically mesoporous silica. The as-received bioactive mesoporous composite exhibited comparable activity and extraordinarily high stability in comparison with native Penicillin G amidase and could be used repetitively in the water-medium hydrolysis of penicillin G potassium salt. Furthermore, this strategy could be extended to the synthesis of multifunctional bioactive mesoporous composite by simultaneously introducing glucose oxidase nanocapsules and horseradish peroxidase nanocapsules into hierarchically mesoporous silica, which demonstrated a synergic effect in one-pot tandem oxidation reaction. Improvements in the catalytic performances were attributed to the combinational unique structure from soft polymer skin and hard inorganic mesoporous silica shell, which cooperatively helped enzyme molecules to retain their appropriate geometry and simultaneously decreased the enzyme-support negative interaction and mass transfer limitation under heterogeneous conditions.

  1. Thin-Layer Polymer Wrapped Enzymes Encapsulated in Hierarchically Mesoporous Silica with High Activity and Enhanced Stability

    PubMed Central

    Zhang, Fang; Wang, Meitao; Liang, Chao; Jiang, Huangyong; Shen, Jian; Li, Hexing

    2014-01-01

    A novel soft-hard cooperative approach was developed to synthesize bioactive mesoporous composite by pre-wrapping Penicillin G amidase with poly(acrylaimde) nanogel skin and subsequently incorporating such Penicillin G amidase nanocapsules into hierarchically mesoporous silica. The as-received bioactive mesoporous composite exhibited comparable activity and extraordinarily high stability in comparison with native Penicillin G amidase and could be used repetitively in the water-medium hydrolysis of penicillin G potassium salt. Furthermore, this strategy could be extended to the synthesis of multifunctional bioactive mesoporous composite by simultaneously introducing glucose oxidase nanocapsules and horseradish peroxidase nanocapsules into hierarchically mesoporous silica, which demonstrated a synergic effect in one-pot tandem oxidation reaction. Improvements in the catalytic performances were attributed to the combinational unique structure from soft polymer skin and hard inorganic mesoporous silica shell, which cooperatively helped enzyme molecules to retain their appropriate geometry and simultaneously decreased the enzyme-support negative interaction and mass transfer limitation under heterogeneous conditions. PMID:24651701

  2. Thin-layer polymer wrapped enzymes encapsulated in hierarchically mesoporous silica with high activity and enhanced stability.

    PubMed

    Zhang, Fang; Wang, Meitao; Liang, Chao; Jiang, Huangyong; Shen, Jian; Li, Hexing

    2014-03-21

    A novel soft-hard cooperative approach was developed to synthesize bioactive mesoporous composite by pre-wrapping Penicillin G amidase with poly(acrylaimde) nanogel skin and subsequently incorporating such Penicillin G amidase nanocapsules into hierarchically mesoporous silica. The as-received bioactive mesoporous composite exhibited comparable activity and extraordinarily high stability in comparison with native Penicillin G amidase and could be used repetitively in the water-medium hydrolysis of penicillin G potassium salt. Furthermore, this strategy could be extended to the synthesis of multifunctional bioactive mesoporous composite by simultaneously introducing glucose oxidase nanocapsules and horseradish peroxidase nanocapsules into hierarchically mesoporous silica, which demonstrated a synergic effect in one-pot tandem oxidation reaction. Improvements in the catalytic performances were attributed to the combinational unique structure from soft polymer skin and hard inorganic mesoporous silica shell, which cooperatively helped enzyme molecules to retain their appropriate geometry and simultaneously decreased the enzyme-support negative interaction and mass transfer limitation under heterogeneous conditions.

  3. Hepatocyte growth factor activator is a potential target proteinase for Kazal-type inhibitor in turkey (Meleagris gallopavo) seminal plasma.

    PubMed

    Słowińska, Mariola; Bukowska, Joanna; Hejmej, Anna; Bilińska, Barbara; Kozłowski, Krzysztof; Jankowski, Jan; Ciereszko, Andrzej

    2015-08-01

    A peculiar characteristic of turkey seminal plasma is the increased activity of serine proteinases. It is of interest if the single-domain Kazal-type inhibitor controls the activity of turkey seminal plasma proteinases. Pure preparations of the Kazal-type inhibitor and anti-Kazal-type inhibitor monospecific immunoglobulin Gs were used as ligands in affinity chromatography for proteinase isolation from turkey seminal plasma. Gene expression and the immunohistochemical detection of the single-domain Kazal-type inhibitor in the reproductive tract of turkey toms are described. The hepatocyte growth factor activator (HGFA) was identified in the binding fraction in affinity chromatography. Hepatocyte growth factor activator activity was inhibited by the Kazal-type inhibitor in a dose-dependent manner. This protease was a primary physiological target for the single-domain Kazal-type inhibitor. Numerous proteoforms of HGFA were present in turkey seminal plasma, and phosphorylation was the primary posttranslational modification of HGFA. In addition to HGFA, acrosin was a target proteinase for the single-domain Kazal-type inhibitor. In seminal plasma, acrosin was present only in complexes with the Kazal-type inhibitor and was not present as a free enzyme. The single-domain Kazal-type inhibitor was specific for the reproductive tract. The germ cell-specific expression of Kazal-type inhibitors in the testis indicated an important function in spermatogenesis; secretion by the epithelial cells of the epididymis and the ductus deferens indicated that the Kazal-type inhibitor was an important factor involved in the changes in sperm membranes during maturation and in the maintenance of the microenvironment in which sperm maturation occurred and sperm was stored. The role of HGFA in these processes remains to be established.

  4. [E. coli penicillin amidase. Physico-chemical properties of the enzyme covalently bound to the 2-(3'-amino-4'-methoxyphenyl)-sulfonylethyl ester of cellulose].

    PubMed

    Nys, P S; Savitskaia, E M; Voronovich, T N; Bulycheva, M S; Virnik, A D

    1977-11-01

    The effect of the procedure of the enzyme binding with the carrier on the properties of the heterogenous catalyst obtained by covalent binding of penicillinamidase (PA) with cellulose 2-(3'-amino-4'-methoxyphenyl)-sulphonylethyl ether by means of the bifunctional reagent, i.e. glutaric aldehyde was studied. It was shown that the amount of the bound enzyme increased with a rise in the amount of the enzyme taken for the binding, while the binding efficiency characterizing the part of the active enzyme in the total amount of the bound PA decreased practically 2 times. The use of the enzyme preparations with different purify levels for the binding provided differentiation of the effects resulting in the activity loss on immobilization. In other words it provided separate estimation of the inactivation effect of the matrix and the immobilization procedure, as well as the interaction of the enzyme molecules with each other and other protein molecules.

  5. Murein Lytic Enzyme TgaA of Bifidobacterium bifidum MIMBb75 Modulates Dendritic Cell Maturation through Its Cysteine- and Histidine-Dependent Amidohydrolase/Peptidase (CHAP) Amidase Domain

    PubMed Central

    Zanoni, Ivan; Balzaretti, Silvia; Miriani, Matteo; Taverniti, Valentina; De Noni, Ivano; Presti, Ilaria; Stuknyte, Milda; Scarafoni, Alessio; Arioli, Stefania; Iametti, Stefania; Bonomi, Francesco; Mora, Diego; Karp, Matti; Granucci, Francesca

    2014-01-01

    Bifidobacteria are Gram-positive inhabitants of the human gastrointestinal tract that have evolved close interaction with their host and especially with the host's immune system. The molecular mechanisms underlying such interactions, however, are largely unidentified. In this study, we investigated the immunomodulatory potential of Bifidobacterium bifidum MIMBb75, a bacterium of human intestinal origin commercially used as a probiotic. Particularly, we focused our attention on TgaA, a protein expressed on the outer surface of MIMBb75's cells and homologous to other known bacterial immunoactive proteins. TgaA is a peptidoglycan lytic enzyme containing two active domains: lytic murein transglycosylase (LT) and cysteine- and histidine-dependent amidohydrolase/peptidase (CHAP). We ran immunological experiments stimulating dendritic cells (DCs) with the B. bifidum MIMBb75 and TgaA, with the result that both the bacterium and the protein activated DCs and triggered interleukin-2 (IL-2) production. In addition, we observed that the heterologous expression of TgaA in Bifidobacterium longum transferred to the bacterium the ability to induce IL-2. Subsequently, immunological experiments performed using two purified recombinant proteins corresponding to the single domains LT and CHAP demonstrated that the CHAP domain is the immune-reactive region of TgaA. Finally, we also showed that TgaA-dependent activation of DCs requires the protein CD14, marginally involves TRIF, and is independent of Toll-like receptor 4 (TLR4) and MyD88. In conclusion, our study suggests that the bacterial CHAP domain is a novel microbe-associated molecular pattern actively participating in the cross talk mechanisms between bifidobacteria and the host's immune system. PMID:24814791

  6. Murein lytic enzyme TgaA of Bifidobacterium bifidum MIMBb75 modulates dendritic cell maturation through its cysteine- and histidine-dependent amidohydrolase/peptidase (CHAP) amidase domain.

    PubMed

    Guglielmetti, Simone; Zanoni, Ivan; Balzaretti, Silvia; Miriani, Matteo; Taverniti, Valentina; De Noni, Ivano; Presti, Ilaria; Stuknyte, Milda; Scarafoni, Alessio; Arioli, Stefania; Iametti, Stefania; Bonomi, Francesco; Mora, Diego; Karp, Matti; Granucci, Francesca

    2014-09-01

    Bifidobacteria are Gram-positive inhabitants of the human gastrointestinal tract that have evolved close interaction with their host and especially with the host's immune system. The molecular mechanisms underlying such interactions, however, are largely unidentified. In this study, we investigated the immunomodulatory potential of Bifidobacterium bifidum MIMBb75, a bacterium of human intestinal origin commercially used as a probiotic. Particularly, we focused our attention on TgaA, a protein expressed on the outer surface of MIMBb75's cells and homologous to other known bacterial immunoactive proteins. TgaA is a peptidoglycan lytic enzyme containing two active domains: lytic murein transglycosylase (LT) and cysteine- and histidine-dependent amidohydrolase/peptidase (CHAP). We ran immunological experiments stimulating dendritic cells (DCs) with the B. bifidum MIMBb75 and TgaA, with the result that both the bacterium and the protein activated DCs and triggered interleukin-2 (IL-2) production. In addition, we observed that the heterologous expression of TgaA in Bifidobacterium longum transferred to the bacterium the ability to induce IL-2. Subsequently, immunological experiments performed using two purified recombinant proteins corresponding to the single domains LT and CHAP demonstrated that the CHAP domain is the immune-reactive region of TgaA. Finally, we also showed that TgaA-dependent activation of DCs requires the protein CD14, marginally involves TRIF, and is independent of Toll-like receptor 4 (TLR4) and MyD88. In conclusion, our study suggests that the bacterial CHAP domain is a novel microbe-associated molecular pattern actively participating in the cross talk mechanisms between bifidobacteria and the host's immune system.

  7. Daughter cell separation is controlled by cytokinetic ring-activated cell wall hydrolysis.

    PubMed

    Uehara, Tsuyoshi; Parzych, Katherine R; Dinh, Thuy; Bernhardt, Thomas G

    2010-04-21

    During bacterial cytokinesis, hydrolytic enzymes are used to split wall material shared by adjacent daughter cells to promote their separation. Precise control over these enzymes is critical to prevent breaches in wall integrity that can cause cell lysis. How these potentially lethal hydrolases are regulated has remained unknown. Here, we investigate the regulation of cell wall turnover at the Escherichia coli division site. We show that two components of the division machinery with LytM domains (EnvC and NlpD) are direct regulators of the cell wall hydrolases (amidases) responsible for cell separation (AmiA, AmiB and AmiC). Using in vitro cell wall cleavage assays, we show that EnvC activates AmiA and AmiB, whereas NlpD activates AmiC. Consistent with these findings, we show that an unregulated EnvC mutant requires functional AmiA or AmiB but not AmiC to induce cell lysis, and that the loss of NlpD phenocopies an AmiC(-) defect. Overall, our results suggest that cellular amidase activity is regulated spatially and temporally by coupling their activation to the assembly of the cytokinetic ring.

  8. Daughter cell separation is controlled by cytokinetic ring-activated cell wall hydrolysis

    PubMed Central

    Uehara, Tsuyoshi; Parzych, Katherine R; Dinh, Thuy; Bernhardt, Thomas G

    2010-01-01

    During bacterial cytokinesis, hydrolytic enzymes are used to split wall material shared by adjacent daughter cells to promote their separation. Precise control over these enzymes is critical to prevent breaches in wall integrity that can cause cell lysis. How these potentially lethal hydrolases are regulated has remained unknown. Here, we investigate the regulation of cell wall turnover at the Escherichia coli division site. We show that two components of the division machinery with LytM domains (EnvC and NlpD) are direct regulators of the cell wall hydrolases (amidases) responsible for cell separation (AmiA, AmiB and AmiC). Using in vitro cell wall cleavage assays, we show that EnvC activates AmiA and AmiB, whereas NlpD activates AmiC. Consistent with these findings, we show that an unregulated EnvC mutant requires functional AmiA or AmiB but not AmiC to induce cell lysis, and that the loss of NlpD phenocopies an AmiC− defect. Overall, our results suggest that cellular amidase activity is regulated spatially and temporally by coupling their activation to the assembly of the cytokinetic ring. PMID:20300061

  9. Activity Augmentation of Amphioxus Peptidoglycan Recognition Protein BbtPGRP3 via Fusion with a Chitin Binding Domain

    PubMed Central

    Wang, Wen-Jie; Cheng, Wang; Luo, Ming; Yan, Qingyu; Yu, Hong-Mei; Li, Qiong; Cao, Dong-Dong; Huang, Shengfeng; Xu, Anlong; Mariuzza, Roy A.; Chen, Yuxing; Zhou, Cong-Zhao

    2015-01-01

    Peptidoglycan recognition proteins (PGRPs), which have been identified in most animals, are pattern recognition molecules that involve antimicrobial defense. Resulting from extraordinary expansion of innate immune genes, the amphioxus encodes many PGRPs of diverse functions. For instance, three isoforms of PGRP encoded by Branchiostoma belcheri tsingtauense, termed BbtPGRP1~3, are fused with a chitin binding domain (CBD) at the N-terminus. Here we report the 2.7 Å crystal structure of BbtPGRP3, revealing an overall structure of an N-terminal hevein-like CBD followed by a catalytic PGRP domain. Activity assays combined with site-directed mutagenesis indicated that the individual PGRP domain exhibits amidase activity towards both DAP-type and Lys-type peptidoglycans (PGNs), the former of which is favored. The N-terminal CBD not only has the chitin-binding activity, but also enables BbtPGRP3 to gain a five-fold increase of amidase activity towards the Lys-type PGNs, leading to a significantly broadened substrate spectrum. Together, we propose that modular evolution via domain shuffling combined with gene horizontal transfer makes BbtPGRP1~3 novel PGRPs of augmented catalytic activity and broad recognition spectrum. PMID:26479246

  10. EC300: a phage-based, bacteriolysin-like protein with enhanced antibacterial activity against Enterococcus faecalis.

    PubMed

    Proença, Daniela; Leandro, Clara; Garcia, Miguel; Pimentel, Madalena; São-José, Carlos

    2015-06-01

    Bacteriophage lytic enzymes, either endolysins or virion-associated lysins, have been receiving considerable attention as potential antibacterial agents, particularly for the combat of antibiotic-resistant Gram-positive pathogens. A conclusion that easily emerges from the careful analysis of a great number of reports on the field is that the activity of phage lytic enzymes is rarely studied in conditions that support robust growth of the target bacteria. Here, we report the construction and study of a chimerical lysin, EC300, which was designed to target and kill Enterococcus faecalis in conditions supporting vigorous bacterial growth. EC300 resulted from the fusion of a predicted M23 endopeptidase domain of a virion-associated lysin to the putative cell wall binding domain of a previously characterized amidase endolysin, both produced by the E. faecalis phage F170/08. This bacteriolysin-like protein exhibited a clear enhanced lytic activity over the parental endolysin when both were assayed in a rich bacterial growth medium. We demonstrate the killing efficacy of EC300 against growing cells of a panel of typed E. faecalis clinical strains with high level of antibiotic resistance. The possible reasons for the marked difference between the lytic performance of EC300 and that of the amidase are discussed.

  11. Subcellular Localization of Rice Leaf Aryl Acylamidase Activity 1

    PubMed Central

    Gaynor, John J.; Still, Cecil C.

    1983-01-01

    The intracellular localization of aryl acylamidase (aryl-acylamide amidohydrolase, EC 3.5.1.13) in rice (Oryza sativa L. var Starbonnet) leaves was investigated. The enzyme hydrolyzes and detoxifies the herbicide propanil (3,4-dichloropropionanilide) thereby accounting for immunity of the rice plant to herbicidal action. Fractionation of mesophyll protoplasts by differential centrifugation yielded the highest specific activity of amidase in the crude mitochondrial fraction. Further separation of density gradients of the silica sol Percoll also indicated that this enzyme was mitochondrial. By the use of biochemical markers, the purified mitochondrial fraction was shown to be substantially free of contamination from nuclei, chloroplasts, golgi, and plasma membranes. Subfractionation of the purified mitochondria suggests that this enzyme is located on the outer membrane. PMID:16662987

  12. Substrate-Competitive Activity-Based Profiling of Ester Prodrug Activating Enzymes.

    PubMed

    Xu, Hao; Majmudar, Jaimeen D; Davda, Dahvid; Ghanakota, Phani; Kim, Ki H; Carlson, Heather A; Showalter, Hollis D; Martin, Brent R; Amidon, Gordon L

    2015-09-08

    Understanding the mechanistic basis of prodrug delivery and activation is critical for establishing species-specific prodrug sensitivities necessary for evaluating preclinical animal models and potential drug-drug interactions. Despite significant adoption of prodrug methodologies for enhanced pharmacokinetics, functional annotation of prodrug activating enzymes is laborious and often unaddressed. Activity-based protein profiling (ABPP) describes an emerging chemoproteomic approach to assay active site occupancy within a mechanistically similar enzyme class in native proteomes. The serine hydrolase enzyme family is broadly reactive with reporter-linked fluorophosphonates, which have shown to provide a mechanism-based covalent labeling strategy to assay the activation state and active site occupancy of cellular serine amidases, esterases, and thioesterases. Here we describe a modified ABPP approach using direct substrate competition to identify activating enzymes for an ethyl ester prodrug, the influenza neuraminidase inhibitor oseltamivir. Substrate-competitive ABPP analysis identified carboxylesterase 1 (CES1) as an oseltamivir-activating enzyme in intestinal cell homogenates. Saturating concentrations of oseltamivir lead to a four-fold reduction in the observed rate constant for CES1 inactivation by fluorophosphonates. WWL50, a reported carbamate inhibitor of mouse CES1, blocked oseltamivir hydrolysis activity in human cell homogenates, confirming CES1 is the primary prodrug activating enzyme for oseltamivir in human liver and intestinal cell lines. The related carbamate inhibitor WWL79 inhibited mouse but not human CES1, providing a series of probes for analyzing prodrug activation mechanisms in different preclinical models. Overall, we present a substrate-competitive activity-based profiling approach for broadly surveying candidate prodrug hydrolyzing enzymes and outline the kinetic parameters for activating enzyme discovery, ester prodrug design, and

  13. Diacerein is a potent and selective inhibitor of palmitoylethanolamide inactivation with analgesic activity in a rat model of acute inflammatory pain.

    PubMed

    Petrosino, Stefania; Ahmad, Akbar; Marcolongo, Gabriele; Esposito, Emanuela; Allarà, Marco; Verde, Roberta; Cuzzocrea, Salvatore; Di Marzo, Vincenzo

    2015-01-01

    Palmitoylethanolamide (PEA) is produced by mammalian cells from its biosynthetic precursor, N-palmitoyl-phosphatidyl-ethanolamine, and inactivated by enzymatic hydrolysis to palmitic acid and ethanolamine. Apart from fatty acid amide hydrolase (FAAH), the N-acylethanolamine-hydrolyzing acid amidase (NAAA), a lysosomal enzyme, was also shown to catalyze the hydrolysis of PEA and to limit its analgesic and anti-inflammatory action. Here we report the finding of a new potential inhibitor of NAAA, EPT4900 (4,5-diacetyloxy-9,10-dioxo-anthracene-2-carboxylic acid, diacerein). EPT4900 exhibited a high inhibitory activity on human recombinant NAAA over-expressed in HEK293 cells (HEK-NAAA cells). EPT4900 selectively increased the levels of PEA in intact HEK-NAAA cells, and inhibited inflammation as well as hyperalgesia in rats treated with an intraplantar injection of carrageenan. This latter effect was accompanied by elevation of PEA endogenous levels in the paw skin.

  14. Activity.

    ERIC Educational Resources Information Center

    Clearing: Nature and Learning in the Pacific Northwest, 1984

    1984-01-01

    Presents three activities: (1) investigating succession in a schoolground; (2) investigating oak galls; and (3) making sun prints (photographs made without camera or darkroom). Each activity includes a list of materials needed and procedures used. (JN)

  15. [Activated Sludge Bacteria Transforming Cyanopyridines and Amides of Pyridinecarboxylic Acids].

    PubMed

    Demakov, V A; Vasil'ev, D M; Maksimova, Yu G; Pavlova, Yu A; Ovechkina, G V; Maksimov, A Yu

    2015-01-01

    Species diversity of bacteria from the activated sludge of Perm biological waste treatment facilities capable of transformation of cyanopyridines and amides of pyridinecarboxylic acids was investigated. Enrichment cultures in mineral media with 3-cyanopyridine as the sole carbon and nitrogen source were used to obtain 32 clones of gram-negative heterotrophic bacteria exhibiting moderate growth on solid and liquid media with 3- and 4-cyanopyridine. Sequencing of the 16S rRNA gene fragments revealed that the clones with homology of at least 99% belonged to the genera Acinetobacte, Alcaligenes, Delftia, Ochrobactrum, Pseudomonas, Stenotrophomonas, and Xanthobacter. PCR analysis showed that 13 out of 32 isolates contained the sequences (-1070 bp) homologous to the nitrilase genes reported previously in Alcaligenes faecalis JM3 (GenBank, D13419.1). Nine clones were capable of nitrile and amide transformation in minimal salt medium. Acinetobacter sp. 11 h and Alcaligenes sp. osv transformed 3-cyanopyridine to nicotinamide, while most of the clones possessed amidase activity (0.5 to 46.3 mmol/(g h) for acetamide and 0.1 to 5.6 mmol/(g h) for nicotinamide). Nicotinamide utilization by strain A. faecalis 2 was shown to result in excretion of a secondary metabolite, which was identified as dodecyl acrylate at 91% probability.

  16. Characterization of AmiBA2446, a Novel Bacteriolytic Enzyme Active against Bacillus Species

    PubMed Central

    Mehta, Krunal K.; Paskaleva, Elena E.; Azizi-Ghannad, Saba; Ley, Daniel J.; Page, Martin A.

    2013-01-01

    There continues to be a need for developing efficient and environmentally friendly treatments for Bacillus anthracis, the causative agent of anthrax. One emerging approach for inactivation of vegetative B. anthracis is the use of bacteriophage endolysins or lytic enzymes encoded by bacterial genomes (autolysins) with highly evolved specificity toward bacterium-specific peptidoglycan cell walls. In this work, we performed in silico analysis of the genome of Bacillus anthracis strain Ames, using a consensus binding domain amino acid sequence as a probe, and identified a novel lytic enzyme that we termed AmiBA2446. This enzyme exists as a homodimer, as determined by size exclusion studies. It possesses N-acetylmuramoyl-l-alanine amidase activity, as determined from liquid chromatography-mass spectrometry (LC-MS) analysis of muropeptides released due to the enzymatic digestion of peptidoglycan. Phylogenetic analysis suggested that AmiBA2446 was an autolysin of bacterial origin. We characterized the effects of enzyme concentration and phase of bacterial growth on bactericidal activity and observed close to a 5-log reduction in the viability of cells of Bacillus cereus 4342, a surrogate for B. anthracis. We further tested the bactericidal activity of AmiBA2446 against various Bacillus species and demonstrated significant activity against B. anthracis and B. cereus strains. We also demonstrated activity against B. anthracis spores after pretreatment with germinants. AmiBA2446 enzyme was also stable in solution, retaining its activity after 4 months of storage at room temperature. PMID:23872558

  17. Carbon starvation increases endoglycosidase activities and production of "unconjugated N-glycans" in Silene alba cell-suspension cultures.

    PubMed Central

    Lhernould, S; Karamanos, Y; Priem, B; Morvan, H

    1994-01-01

    We previously reported the occurrence of oligomannosides and xylomannosides corresponding to unconjugated N-glycans (UNGs) in the medium of a white campion (Silene alba) cell suspension. Attention has been focused on these oligosaccharides since it was shown that they confer biological activities in plants. In an attempt to elucidate the origin of these oligosaccharides, we studied two endoglycosidase activities, putative enzymes involved in their formation. The previously described peptide-N4-(N-acetyl-glucosaminyl) asparagine amidase activity and the endo-N-acetyl-beta-D-glucosaminidase activity described in this paper were both quantified in white campion cells during the culture cycle with variable initial concentrations of sucrose. The lower the sucrose supply, the higher the two activities. Furthermore, endoglycosidase activities were greatly enhanced after the disappearance of sugar from the medium. The production of UNGs in the culture medium rose correlatively. These data strongly suggest that the production of UNGs in our white campion cell-suspension system is due to the increase of these endoglycosidase activities, which reach their highest levels of activity during conditions of carbon starvation. PMID:7991689

  18. Activities.

    ERIC Educational Resources Information Center

    Bippert, Judy

    1993-01-01

    Presents activities designed to give students an opportunity to solve concrete problems involving spatial relationships and logical thinking utilizing hands-on manipulatives. Provides teacher instructions and four reproducible worksheets. (MDH)

  19. Improved Production of Active Streptomyces griseus Trypsin with a Novel Auto-Catalyzed Strategy

    PubMed Central

    Zhang, Yunfeng; Ling, Zhenmin; Du, Guocheng; Chen, Jian; Kang, Zhen

    2016-01-01

    N-terminal sequences play crucial roles in regulating expression, translation, activation and enzymatic properties of proteins. To reduce cell toxicity of intracellular trypsin and increase secretory expression, we developed a novel auto-catalyzed strategy to produce recombinant trypsin by engineering the N-terminus of mature Streptomyces griseus trypsin (SGT). The engineered N-terminal peptide of SGT was composed of the thioredoxin, glycine-serine linker, His6-tag and the partial bovine trypsinogen pro-peptide (DDDDK). Furthermore, we constructed a variant TLEI with insertion of the artificial peptide at N-terminus and site-directed mutagenesis of the autolysis residue R145. In fed-batch fermentation, the production of extracellular trypsin activity was significantly improved to 47.4 ± 1.2 U·ml−1 (amidase activity, 8532 ± 142.2 U·ml−1 BAEE activity) with a productivity of 0.49 U·ml−1·h−1, which was 329% greater than that of parent strain Pichia pastoris GS115-SGT. This work has significant potential to be scaled-up for microbial production of SGT. In addition, the N-terminal peptide engineering strategy can be extended to improve heterologous expression of other toxic enzymes. PMID:26983398

  20. Ubiquitin-activating enzyme (UBA1) is required for sperm capacitation, acrosomal exocytosis and sperm-egg coat penetration during porcine fertilization.

    PubMed

    Yi, Y-J; Zimmerman, S W; Manandhar, G; Odhiambo, J F; Kennedy, C; Jonáková, V; Maňásková-Postlerová, P; Sutovsky, M; Park, C-S; Sutovsky, P

    2012-04-01

    Protein ubiquitination is a stable, covalent post-translational modification that alters protein activity and/or targets proteins for proteolysis by the 26S proteasome. The E1-type ubiquitin-activating enzyme (UBA1) is responsible for ubiquitin activation, the initial step of ubiquitin-protein ligation. Proteasomal proteolysis of ubiquitinated spermatozoa and oocyte proteins occurs during mammalian fertilization, particularly at the site of sperm acrosome contact with oocyte zona pellucida. However, it is not clear whether the substrates are solely proteins ubiquitinated during gametogenesis or if de novo ubiquitination also occurs during fertilization supported by ubiquitin-activating and -conjugating enzymes present in the sperm acrosome. Along this line of inquiry, UBA1 was detected in boar sperm-acrosomal extracts by Western blotting (WB). Immunofluorescence revealed accumulation of UBA1 in the nuclei of spermatogonia, spermatocytes and spermatids, and in the acrosomal caps of round and elongating spermatids. Thiol ester assays utilizing biotinylated ubiquitin and isolated sperm acrosomes confirmed the enzymatic activity of the resident UBA1. A specific UBA1 inhibitor, PYR-41, altered the remodelling of the outer acrosomal membrane (OAM) during sperm capacitation, monitored using flow cytometry of fluorescein isothiocyanate-conjugated peanut agglutinin (FITC-PNA). Although viable and motile, the spermatozoa capacitated in the presence of PYR-41, showed significantly reduced fertilization rates during in vitro fertilization (IVF; p < 0.05). Similarly, the fertilization rate was lowered by the addition of PYR-41 directly into fertilization medium during IVF. In WB, high Mr bands, suggestive of protein ubiquitination, were detected in non-capacitated spermatozoa by antibodies against ubiquitin; WB with anti-phosphotyrosine antibodies and antibodies against acrosomal proteins SPINK2 (acrosin inhibitor) and AQN1 (spermadhesin) revealed that the capacitation

  1. Activities.

    ERIC Educational Resources Information Center

    Kincaid, Charlene; And Others

    1993-01-01

    Presents an activity in which students collect and organize data from a real-world simulation of the scientific concept of half life. Students collect data using a marble sifter, analyze the data using a graphing calculator, and determine an appropriate mathematical model. Includes reproducible worksheets. (MDH)

  2. Preparation and characterization of kasuga-silica-conjugated nanospheres for sustained antimicrobial activity

    NASA Astrophysics Data System (ADS)

    Ding, Guanglong; Li, Deguang; Liu, Yao; Guo, Mingcheng; Duan, Yongheng; Li, Jianqiang; Cao, Yongsong

    2014-11-01

    Controlled release formulation of pesticides is highly desirable for attaining the most effective utilization of the pesticide as well as reducing environmental pollution. Nano-sized controlled release formulations can provide better penetration through cuticle and deliver the active ingredients efficiently to the targeted tissue. In this study, a novel strategy for the preparation of a nanoconjugate derived from kasugamycin with amino-modified silica was developed. The kasugamycin was connected with amino-modified silica matrix by an amide bond, which could avoid the initial burst release effectively and prolong the duration remarkably. The results showed the kasuga-silica can protect kasugamycin against photo-degradation effectively and the release rate of the active ingredient of nanoconjugate was related to the temperature, pH value, and the particle size (52.5-315.4 nm). With reduced particle size as well as increased temperature and acidity, the release of the active ingredient was faster. This amide linkage of kasuga-silica could be degraded by amidase effectively. This nanoconjugate displayed a better and a sustained bactericidal efficacy against E. coli than kasugamycin technical, which makes it a potential candidate as a controlled release conjugate for kasugamycin in the future.

  3. Pseudomonas aeruginosa mutants resistant to urea inhibition of growth on acetanilide.

    PubMed

    Gregoriou, M; Brown, P R; Tata, R

    1977-11-01

    Pseudomonas aeruginosa AI 3 was able to grow in medium containing acetanilide (N-phenylacetamide) as a carbon source when NH4+ was the nitrogen source but not when urea was the nitrogen source. AIU mutants isolated from strain AI 3 grew on either medium. Urease levels in bacteria grown in the presence of urea were 10-fold lower when NH4+ or acetanilide was also in the medium, but there were no apparent differences in urease or its synthesis between strain AI 3 and mutant AIU 1N. The first metabolic step in the acetanilide utlization is catalyzed by an amidase. Amidases in several AIU strains showed altered physiochemical properties. Urea inhibited amidase in a time-dependent reaction, but the rates of the inhibitory reaction with amidases from the AIU mutants were slower than with AI 3 amidase. The purified amidase from AIU 1N showed a marked difference in its pH/activity profile from that obtained with purified AI 3 amidase. These observations indicate that the ability of strain AIU 1N and the other mutants to grow on acetanilide/urea medium is associated with a mutation in the amidase structural gene; this was confirmed for strain AIU 1N by transduction.

  4. Staphylococcus haemolyticus prophage ΦSH2 endolysin relies on cysteine, histidine-dependent amidohydrolases/peptidases activity for lysis 'from without'.

    PubMed

    Schmelcher, Mathias; Korobova, Olga; Schischkova, Nina; Kiseleva, Natalia; Kopylov, Paul; Pryamchuk, Sergey; Donovan, David M; Abaev, Igor

    2012-12-31

    Staphylococcus aureus is an important pathogen, with methicillin-resistant (MRSA) and multi-drug resistant strains becoming increasingly prevalent in both human and veterinary clinics. S. aureus causing bovine mastitis yields high annual losses to the dairy industry. Conventional treatment of mastitis by broad range antibiotics is often not successful and may contribute to development of antibiotic resistance. Bacteriophage endolysins present a promising new source of antimicrobials. The endolysin of prophage ΦSH2 of Staphylococcus haemolyticus strain JCSC1435 (ΦSH2 lysin) is a peptidoglycan hydrolase consisting of two catalytic domains (CHAP and amidase) and an SH3b cell wall binding domain. In this work, we demonstrated its lytic activity against live staphylococcal cells and investigated the contribution of each functional module to bacterial lysis by testing a series of deletion constructs in zymograms and turbidity reduction assays. The CHAP domain exhibited three-fold higher activity than the full length protein and optimum activity in physiological saline. This activity was further enhanced by the presence of bivalent calcium ions. The SH3b domain was shown to be required for full activity of the complete ΦSH2 lysin. The full length enzyme and the CHAP domain showed activity against multiple staphylococcal strains, including MRSA strains, mastitis isolates, and CoNS.

  5. Phage endolysins with broad antimicrobial activity against Enterococcus faecalis clinical strains.

    PubMed

    Proença, Daniela; Fernandes, Sofia; Leandro, Clara; Silva, Filipa Antunes; Santos, Sofia; Lopes, Fátima; Mato, Rosario; Cavaco-Silva, Patrícia; Pimentel, Madalena; São-José, Carlos

    2012-06-01

    Increasing antibiotic resistance of bacterial pathogens has drawn the attention to the potential use of bacteriophage endolysins as alternative antibacterial agents. Here we have identified, characterized, and studied the lytic potential of two endolysins, Lys168 and Lys170, from phages infecting Enterococcus faecalis. Lys168 and Lys170 belong to the cysteine, histidine-dependent amidohydrolases/peptidases (CHAP) and amidase-2 protein families, respectively. Lys168 is quite a unique enterococcal phage endolysin. It shares 95% amino acidic identity with the endolysin of Staphylococcus aureus phage SAP6, which in turn is distantly related to all known CHAP endolysins of S. aureus phages. Lys170 seems to be a natural chimera assembling catalytic and cell-wall-binding domains of different origin. Both endolysins showed a clear preference to act against E. faecalis and they were able to lyse a high proportion of clinical isolates of this species. Specifically, Lys168 and Lys170 lysed more than 70% and 90% of the tested isolates, respectively, which included a panel of diverse and typed strains representative of highly prevalent clonal complexes. Lys170 was active against all tested E. faecalis VRE strains. The quasi specificity toward E. faecalis is discussed considering the nature of the enzymes' functional domains and the structure of the cell wall peptidoglycan.

  6. Isolation and characterization of a novel phage lysin active against Paenibacillus larvae, a honeybee pathogen

    PubMed Central

    LeBlanc, Lucy; Nezami, Sara; Yost, Diane; Tsourkas, Philippos; Amy, Penny S

    2015-01-01

    Paenibacillus larvae is the causative agent of American foulbrood (AFB) disease which affects early larval stages during honeybee development. Due to its virulence, transmissibility, capacity to develop antibiotic resistance, and the inherent resilience of its endospores, Paenibacillus larvae is extremely difficult to eradicate from infected hives which often must be burned. AFB contributes to the worldwide decline of honeybee populations, which are crucial for pollination and the food supply. We have isolated a novel bacteriophage lysin, PlyPalA, from the genome of a novel Paenibacillus larvae bacteriophage originally extracted from an environmental sample. PlyPalA has an N-terminal N-acetylmuramoyl-L-alanine amidase catalytic domain and possesses lytic activity against infectious strains of Paenibacillus larvae without harming commensal bacteria known to compose the honeybee larval microbiota. A single dose of PlyPalA rescued 75% of larvae infected with endospores, showing that it represents a powerful tool for future treatment of AFB. This represents the first time that lysins have been tested for therapeutic use in invertebrates. PMID:26904379

  7. Factor C acts as a lipopolysaccharide-responsive C3 convertase in horseshoe crab complement activation.

    PubMed

    Ariki, Shigeru; Takahara, Shusaku; Shibata, Toshio; Fukuoka, Takaaki; Ozaki, Aya; Endo, Yuichi; Fujita, Teizo; Koshiba, Takumi; Kawabata, Shun-ichiro

    2008-12-01

    The complement system in vertebrates plays an important role in host defense against and clearance of invading microbes, in which complement component C3 plays an essential role in the opsonization of pathogens, whereas the molecular mechanism underlying C3 activation in invertebrates remains unknown. In an effort to understand the molecular activation mechanism of invertebrate C3, we isolated and characterized an ortholog of C3 (designated TtC3) from the horseshoe crab Tachypleus tridentatus. Flow cytometric analysis using an Ab against TtC3 revealed that the horseshoe crab complement system opsonizes both Gram-negative and Gram-positive bacteria. Evaluation of the ability of various pathogen-associated molecular patterns to promote the proteolytic conversion of TtC3 to TtC3b in hemocyanin-depleted plasma indicated that LPS, but not zymosan, peptidoglycan, or laminarin, strongly induces this conversion, highlighting the selective response of the complement system to LPS stimulation. Although originally characterized as an LPS-sensitive initiator of hemolymph coagulation stored within hemocytes, we identified factor C in hemolymph plasma. An anti-factor C Ab inhibited various LPS-induced phenomena, including plasma amidase activity, the proteolytic activation of TtC3, and the deposition of TtC3b on the surface of Gram-negative bacteria. Moreover, activated factor C present on the surface of Gram-negative bacteria directly catalyzed the proteolytic conversion of the purified TtC3, thereby promoting TtC3b deposition. We conclude that factor C acts as an LPS-responsive C3 convertase on the surface of invading Gram-negative bacteria in the initial phase of horseshoe crab complement activation.

  8. Quantitative Structure-Activity Relationships for Organophosphate Enzyme Inhibition (Briefing Charts)

    DTIC Science & Technology

    2011-09-22

    Cleft Muscarinic/Nicotinic Receptor Cholinergic Nervous System “Normal Mechanism of Action” Citrate Pyruvate Acetyl CoA + + 6 Cholinergic...Choline Carrier Synaptic Cleft Muscarinic/Nicotinic Receptor CoA + + Acetylcholinesterase Hyperstimulation Citrate Pyruvate 7 Physiologically...neurotoxicity FAAH, CB1 Cannabinoid interactions AFMID teratogenesis APH neuropeptide metabolism Carboxylesterases Amidases Toxicity

  9. Peltatoside Isolated from Annona crassiflora Induces Peripheral Antinociception by Activation of the Cannabinoid System.

    PubMed

    Oliveira, Cristina da Costa; Veloso, Clarice de Carvalho; Ferreira, Renata Cristina Mendes; Lage, Gisele Avelar; Pimenta, Lúcia Pinheiro Santos; Duarte, Igor Dimitri Gama; Romero, Thiago Roberto Lima; Perez, Andrea de Castro

    2017-02-01

    Peltatoside is a natural compound isolated from leaves of Annona crassiflora Mart., a plant widely used in folk medicine. This substance is an analogue of quercetin, a flavonoid extensively studied because of its diverse biological activities, including analgesic effects. Besides, a previous study suggested, by computer structure analyses, a possible quercetin-CB1 cannabinoid receptor interaction. Thus, the aim of this work was to assess the antinociceptive effect of peltatoside and analyze the cannabinoid system involvement in this action. The mouse paw pressure test was used and hyperalgesia was induced by intraplantar injection of carrageenan (200 µg/paw). All used drugs were administered by intraplantar administration in Swiss male mice (n = 6). Peltatoside (100 µg/paw) elicited a local inhibition of hyperalgesia. The peripheral antinociceptive action of peltatoside was antagonized by the CB1 cannabinoid antagonist AM251 (160 µg/paw), but not by CB2 cannabinoid antagonist AM630 (100 µg/paw). In order to assess the role of endocannabinoids in this peripheral antinociceptive effect, we used (i) [5Z,8Z,11Z,14Z]-5,8,11,14-eicosatetraenyl-methyl ester phosphonofluoridic acid, an inhibitor of anandamide amidase; (ii) JZL184, an inhibitor for monoacylglycerol lipase, the primary enzyme responsible for degrading the endocannabinoid 2-arachidonoylglycerol; and (iii) VDM11, an endocannabinoid reuptake inhibitor. MAFP, JZL184, and VDM11 did not induce antinociception, respectively, at the doses 0.5, 3.8, and 2.5 µg/paw, however, these three drugs were able to potentiate the peripheral antinociceptive effect of peltatoside at an intermediary dose (50 µg/paw). Our results suggest that this natural substance is capable of inducing analgesia through the activation of peripheral CB1 receptors, involving endocannabinoids in this process.

  10. Structural and biochemical studies on Vibrio cholerae Hsp31 reveals a novel dimeric form and Glutathione-independent Glyoxalase activity

    PubMed Central

    Dey, Sanjay

    2017-01-01

    Vibrio cholerae experiences a highly hostile environment at human intestine which triggers the induction of various heat shock genes. The hchA gene product of V. cholerae O395, referred to a hypothetical intracellular protease/amidase VcHsp31, is one such stress-inducible homodimeric protein. Our current study demonstrates that VcHsp31 is endowed with molecular chaperone, amidopeptidase and robust methylglyoxalase activities. Through site directed mutagenesis coupled with biochemical assays on VcHsp31, we have confirmed the role of residues in the vicinity of the active site towards amidopeptidase and methylglyoxalase activities. VcHsp31 suppresses the aggregation of insulin in vitro in a dose dependent manner. Through crystal structures of VcHsp31 and its mutants, grown at various temperatures, we demonstrate that VcHsp31 acquires two (Type-I and Type-II) dimeric forms. Type-I dimer is similar to EcHsp31 where two VcHsp31 monomers associate in eclipsed manner through several intersubunit hydrogen bonds involving their P-domains. Type-II dimer is a novel dimeric organization, where some of the intersubunit hydrogen bonds are abrogated and each monomer swings out in the opposite directions centering at their P-domains, like twisting of wet cloth. Normal mode analysis (NMA) of Type-I dimer shows similar movement of the individual monomers. Upon swinging, a dimeric surface of ~400Å2, mostly hydrophobic in nature, is uncovered which might bind partially unfolded protein substrates. We propose that, in solution, VcHsp31 remains as an equilibrium mixture of both the dimers. With increase in temperature, transformation to Type-II form having more exposed hydrophobic surface, occurs progressively accounting for the temperature dependent increase of chaperone activity of VcHsp31. PMID:28235098

  11. Role of the major pneumococcal autolysin in the atypical response of a clinical isolate of Streptococcus pneumoniae.

    PubMed Central

    Díaz, E; López, R; García, J L

    1992-01-01

    The autolytic enzyme (an N-acetylmuramyl-L-alanine amidase) of a clinical isolate, strain 101/87, which is classified as an atypical pneumococcus, has been studied for the first time. The lytA101 gene coding for this amidase (LYTA101) has been cloned, sequenced, and expressed in Escherichia coli. The LYTA101 amidase has been purified and shown to be similar to the main autolytic enzyme (LYTA) present in the wild-type strain of Streptococcus pneumoniae, although it exhibits a lower specific activity, a higher sensitivity to inhibition by free choline, and a modified thermosensitivity with respect to LYTA. Most important, in contrast with the LYTA amidase, the activity of the LYTA101 amidase was inhibited by sodium deoxycholate. This property is most probably responsible of the deoxycholate-insensitive phenotype shown by strain 101/87. Phenotypic curing of strain 101/87 by externally adding purified LYTA or LYTA101 amidase restored in this strain some typical characteristics of the wild-type strain of pneumococcus (e.g., formation of diplo cells and sensitization to lysis by sodium deoxycholate), although the amount of the LYTA101 amidase required to restore these properties was much higher than in the case of the LYTA amidase. Our results indicate that modifications in the primary structure or in the mechanisms that control the activity of cell wall lytic enzymes seem to be responsible for the characteristics exhibited by some strains of S. pneumoniae that have been classically misclassified and should be now considered atypical pneumococcal strains. Images PMID:1355082

  12. Selective and reversible thiol-pegylation, an effective approach for purification and characterization of five fully active ficin (iso)forms from Ficus carica latex.

    PubMed

    Azarkan, Mohamed; Matagne, André; Wattiez, Ruddy; Bolle, Laetitia; Vandenameele, Julie; Baeyens-Volant, Danielle

    2011-10-01

    The latex of Ficus carica constitutes an important source of many proteolytic components known under the general term of ficin (EC 3.4.22.3) which belongs to the cysteine proteases of the papain family. So far, no data on the purification and characterization of individual forms of these proteases are available. An effective strategy was used to fractionate and purify to homogeneity five ficin forms, designated A, B, C, D1 and D2 according to their sequence of elution from a cation-exchange chromatographic support. Following rapid fractionation on a SP-Sepharose Fast Flow column, the different ficin forms were chemically modified by a specific and reversible monomethoxypolyethylene glycol (mPEG) reagent. In comparison with their un-derivatized counterparts, the mPEG-protein derivatives behaved differently on the ion-exchanger, allowing us for the first time to obtain five highly purified ficin molecular species titrating 1mol of thiol group per mole of enzyme. The purified ficins were characterized by de novo peptide sequencing and peptide mass fingerprinting analyzes, using mass spectrometry. Circular dichroism measurements indicated that all five ficins were highly structured, both in term of secondary and tertiary structure. Furthermore, analysis of far-UV CD spectra allowed calculation of their secondary structural content. Both these data and the molecular masses determined by MS reinforce the view that the enzymes belong to the family of papain-like proteases. The five ficin forms also displayed different specific amidase activities against small synthetic substrates like dl-BAPNA and Boc-Ala-Ala-Gly-pNA, suggesting some differences in their active site organization. Enzymatic activity of the five ficin forms was completely inhibited by specific cysteine and cysteine/serine proteases inhibitors but was unaffected by specific serine, aspartic and metallo proteases inhibitors.

  13. Bacteriophages of the family siphoviridae contain amidase enzymes that lyse Clostridium perfringens

    Technology Transfer Automated Retrieval System (TEKTRAN)

    *Agtech-Danisco, current address In chickens Clostridium perfringens (Cp) is the etiologic agent of necrotic enteritis and causes gas gangrene along with being the third leading cause of bacterial food-borne gastroenteritis in humans. While the disease in poultry can be controlled by antibiotics, th...

  14. BACTERIOPHAGES OF THE FAMILY SIPHOVIRIDAE CONTAIN AMIDASE ENZYMES THAT LYSE CLOSTRIDIUM PERFRINGENS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In chickens Clostridium perfringens (Cp) is the etiologic agent of necrotic enteritis and causes gas gangrene along with being the third leading cause of bacterial food-borne gastroenteritis in humans. While the disease in poultry can be controlled by antibiotics, there is increasing pressure to ban...

  15. High Systemic Exposure of Pyrazinoic Acid Has Limited Antituberculosis Activity in Murine and Rabbit Models of Tuberculosis

    PubMed Central

    Tasneen, Rokeya; O'Brien, Paul; Sarathy, Jansy; Safi, Hassan; Pinn, Michael; Alland, David; Dartois, Véronique

    2016-01-01

    Pyrazinamide (PZA) is a prodrug requiring conversion to pyrazinoic acid (POA) by an amidase encoded by pncA for in vitro activity. Mutation of pncA is the most common cause of PZA resistance in clinical isolates. To determine whether the systemic delivery of POA or host-mediated conversion of PZA to POA could circumvent such resistance, we evaluated the efficacy of orally administered and host-derived POA in vivo. Dose-ranging plasma and intrapulmonary POA pharmacokinetics and the efficacy of oral POA or PZA treatment against PZA-susceptible tuberculosis were determined in BALB/c and C3HeB/FeJ mice. The activity of host-derived POA was assessed in rabbits infected with a pncA-null mutant and treated with PZA. Median plasma POA values for the area under the concentration-time curve from 0 h to infinity (AUC0–∞) were 139 to 222 μg·h/ml and 178 to 287 μg·h/ml after doses of PZA and POA of 150 mg/kg of body weight, respectively, in mice. Epithelial lining fluid POA concentrations in infected mice were comparable after POA and PZA administration. In chronically infected BALB/c mice, PZA at 150 mg/kg reduced lung CFU counts by >2 log10 after 4 weeks. POA was effective only at 450 mg/kg, which reduced lung CFU counts by ∼0.7 log10. POA had no demonstrable bactericidal activity in C3HeB/FeJ mice, nor did PZA administered to rabbits infected with a PZA-resistant mutant. Oral POA administration and host-mediated conversion of PZA to POA producing plasma POA exposures comparable to PZA administration was significantly less effective than PZA. These results suggest that the intrabacillary delivery of POA and that producing higher POA concentrations at the site of infection will be more effective strategies for maximizing POA efficacy. PMID:27139472

  16. Effect of You Gui Wan on mouse sperm fertilising ability in vivo and in vitro.

    PubMed

    Jiang, X-H; Yie, S-M; Zhen, X; Den, Y-L; Liang, X; Hu, X; Li, L-M; Li, Q-J; Cao, S; Lu, H

    2014-04-01

    This study is to explore whether YGW has an impact on sperm fertilising ability in mice. Twenty male mice were randomly divided into two groups. In vivo experiments, one group of animals were orally administrated with YGW decoction and another group administered with saline for 14 days. Afterwards, the animals were mated with their female partners. Percentages of retrieved zygotes were then compared. In vitro experiments, in vitro fertilisation (IVF) assay, sperm acrosome reaction and acrosin activity were used to compare sperm fertilising ability between the two groups. The YGW-treated group had a significantly higher percentage of zygotes than the saline controls (P = 0.005). The IVF rates induced by spermatozoa from the herb-treated mice were also significantly higher than those from the control animals (P = 0.015). The sperm acrosin activity of the herb-treated group was significantly higher than that of the saline-treated group (P = 0.048), although there was no significant difference in testicular weight, sperm count and sperm motility. These data suggest that YGW decoction has a significant effect on normal sperm fertilising ability both in vivo and in vitro, which may be due to, at least in part, increments in the sperm acrosin activity.

  17. Association between phthalate metabolites and biomarkers of reproductive function in 1066 Chinese men of reproductive age.

    PubMed

    Pan, Yitao; Jing, Jun; Dong, Fengshou; Yao, Qi; Zhang, Wei; Zhang, Hongxia; Yao, Bing; Dai, Jiayin

    2015-12-30

    Phthalates are suspected endocrine disrupting chemicals that impair male reproductive function in animal and epidemiological studies. We investigated associations between urinary phthalate metabolites and acrosin activity, along with that between insulin like-factor 3 (INSL3), a Leydig cell function marker, in Chinese adult men and assessed the association between the metabolites and male reproductive function. Serum levels of INSL3 and other hormones, semen parameters, and urinary concentrations of 14 phthalate metabolites in 1066 men were measured. The unadjusted concentrations of phthalates were included as independent variables and urinary creatinine as a separate covariate. INSL3 was negatively associated with mono-2-ethylhexyl phthalate (MEHP) and %MEHP [percentage of MEHP to all di(2-ethylhexyl) phthalate (DEHP) metabolites]. Acrosin activity was negatively associated with mono-n-butyl phthalate (MBP), mono-isobutyl phthalate (MiBP), MEHP and %MEHP. MBP and MiBP were also negatively associated with total testosterone (T), free androgen index (FAI), free testosterone (FT), luteinizing hormone (LH) and sperm morphology and positively associated with DNA fragmentation index (DFI). A negative association between %MEHP and sperm motility was observed. Several other metabolites were also associated with reproductive function. This is the first report on the inverse associations of phthalate metabolites with acrosin activity and INSL3. Phthalates may cause multiple adverse results on reproductive function at environmental levels.

  18. Examination of Potential Anti-Tumor Activity of N-Thiolated b-Lactam Antibiotics in Nude Mice Bearing Human Breast Tumors

    DTIC Science & Technology

    2006-08-01

    to their mechanism of action, production of reactive oxygen species (ROS), which leads to toxicity of the cardiomyocytes and subsequent chronic and...agents for methicillin-resistant Staphylococcus aureus. Bioorg Med Chem Lett 12, 2229-2231 (2002) 14. Holt, R.J. and G.T. Stewart: Production of Amidase...drugs, termed N-thiolated beta- lactams, which are highly effective at inhibiting bacterial growth in drug-resistant strains of Staphylococcus aureus (5

  19. The Gonococcal NlpD Protein Facilitates Cell Separation by Activating Peptidoglycan Cleavage by AmiC

    PubMed Central

    Stohl, Elizabeth A.; Lenz, Jonathan D.; Dillard, Joseph P.

    2015-01-01

    ABSTRACT Key steps in bacterial cell division are the synthesis and subsequent hydrolysis of septal peptidoglycan (PG), which allow efficient separation of daughter cells. Extensive studies in the Gram-negative, rod-shaped bacterium Escherichia coli have revealed that this hydrolysis is highly regulated spatially and temporally. Neisseria gonorrhoeae is an obligate Gram-negative, diplococcal pathogen and is the only causative agent of the sexually transmitted infection gonorrhea. We investigated how cell separation proceeds in this diplococcal organism. We demonstrated that deletion of the nlpD gene in strain FA1090 leads to poor growth and to an altered colony and cell morphology. An isopropyl-beta-d-galactopyranoside (IPTG)-regulated nlpD complemented construct can restore these defects only when IPTG is supplied in the growth medium. Thin-section transmission electron microscopy (TEM) revealed that the nlpD mutant strain grew in large clumps containing live and dead bacteria, which was consistent with deficient cell separation. Biochemical analyses of purified NlpD protein showed that it was able to bind purified PG. Finally, we showed that, although NlpD has no hydrolase activity itself, NlpD potentiates the hydrolytic activity of AmiC. These results indicate that N. gonorrhoeae NlpD is required for proper cell growth and division through its interactions with the amidase AmiC. IMPORTANCE N. gonorrhoeae is the sole causative agent of the sexually transmitted infection gonorrhea. The incidence of antibiotic-resistant gonococcal infections has risen sharply in recent years, and N. gonorrhoeae has been classified as a “superbug” by the CDC. Since there is a dearth of new antibiotics to combat gonococcal infections, elucidating the essential cellular process of N. gonorrhoeae may point to new targets for antimicrobial therapies. Cell division and separation is one such essential process. We identified and characterized the gonococcal nlpD gene and showed that

  20. Active-R filter

    DOEpatents

    Soderstrand, Michael A.

    1976-01-01

    An operational amplifier-type active filter in which the only capacitor in the circuit is the compensating capacitance of the operational amplifiers, the various feedback and coupling elements being essentially solely resistive.

  1. Get Active

    MedlinePlus

    ... Basics: Health Benefits What are the benefits of physical activity? Physical activity increases your chances of living longer. ... pain Help you feel better about yourself Is physical activity for everyone? Yes! Physical activity is good for ...

  2. A chimeric LysK-lysostaphin fusion enzyme lysing Staphylococcus aureus cells: a study of both kinetics of inactivation and specifics of interaction with anionic polymers

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A staphylolytic fusion protein (K-L) was created, harboring three unique lytic activities comprised of the LysK CHAP endopeptidase, and amidase domains, and the lysostaphin glycyl-glycine endopeptidase domain. To assess the potential of possible therapeutic applications, the kinetic behavior of K-L...

  3. The proteolytic system of pineapple stems revisited: Purification and characterization of multiple catalytically active forms.

    PubMed

    Matagne, André; Bolle, Laetitia; El Mahyaoui, Rachida; Baeyens-Volant, Danielle; Azarkan, Mohamed

    2017-02-23

    Crude pineapple proteases extract (aka stem bromelain; EC 3.4.22.4) is an important proteolytic mixture that contains enzymes belonging to the cysteine proteases of the papain family. Numerous studies have been reported aiming at the fractionation and characterization of the many molecular species present in the extract, but more efforts are still required to obtain sufficient quantities of the various purified protease forms for detailed physicochemical, enzymatic and structural characterization. In this work, we describe an efficient strategy towards the purification of at least eight enzymatic forms. Thus, following rapid fractionation on a SP-Sepharose FF column, two sub-populations with proteolytic activity were obtained: the unbound (termed acidic) and bound (termed basic) bromelain fractions. Following reversible modification with monomethoxypolyethylene glycol (mPEG), both fractions were further separated on Q-Sepharose FF and SP-Sepharose FF, respectively. This procedure yielded highly purified molecular species, all titrating ca. 1 mol of thiol group per mole of enzyme, with distinct biochemical properties. N-terminal sequencing allowed identifying at least eight forms with proteolytic activity. The basic fraction contained previously identified species, i.e. basic bromelain forms 1 and 2, ananain forms 1 and 2, and comosain (MEROPS identifier: C01.027). Furthermore, a new proteolytic species, showing similarities with basic bomelain forms 1 and 2, was discovered and termed bromelain form 3. The two remaining species were found in the acidic bromelain fraction and were arbitrarily named acidic bromelain forms 1 and 2. Both, acidic bromelain forms 1, 2 and basic bromelain forms 1, 2 and 3 are glycosylated, while ananain forms 1 and 2, and comosain are not. The eight protease forms display different amidase activities against the various substrates tested, namely small synthetic chromogenic compounds (DL-BAPNA and Boc-Ala-Ala-Gly-pNA), fluorogenic compounds

  4. Activation detector

    DOEpatents

    Bell, Zane William [Oak Ridge, TN; Boatner, Lynn Allen [Oak Ridge, TN

    2009-12-08

    A method of detecting an activator, the method including impinging with an activator a receptor material lacking a photoluminescent material and generating a by-product of a radioactive decay due to the activator impinging the reeptor material. The method further including, generating light from the by-product via the Cherenkov effect and identifying a characteristic of the activator based on the light.

  5. In Vitro Effect of Cell Phone Radiation on Motility, DNA Fragmentation and Clusterin Gene Expression in Human Sperm

    PubMed Central

    Zalata, Adel; El-Samanoudy, Ayman Z; Shaalan, Dalia; El-Baiomy, Youssef; Mostafa, Taymour

    2015-01-01

    Background Use of cellular phones emitting radiofrequency electromagnetic field (RF-EMF) has been increased exponentially and become a part of everyday life. This study aimed to investigate the effects of in vitro RF-EMF exposure emitted from cellular phones on sperm motility index, sperm DNA fragmentation and seminal clusterin (CLU) gene expression. Materials and Methods In this prospective study, a total of 124 semen samples were grouped into the following main categories: i. normozoospermia (N, n=26), ii. asthenozoospermia (A, n=32), iii. asthenoteratozoospermia (AT, n=31) and iv. oligoasthenoteratozoospermia (OAT, n=35). The same semen samples were then divided into two portions non-exposed and exposed samples to cell phone radiation for 1 hour. Before and immediately after exposure, both aliquots were subjected to different assessments for sperm motility, acrosin activity, sperm DNA fragmentation and CLU gene expression. Statistical differences were analyzed using paired t student test for comparisons between two sub-groups where p<0.05 was set as significant. Results There was a significant decrease in sperm motility, sperm linear velocity, sperm linearity index, and sperm acrosin activity, whereas there was a significant increase in sperm DNA fragmentation percent, CLU gene expression and CLU protein levels in the exposed semen samples to RF-EMF compared with non-exposed samples in OAT>AT>A>N groups, respectively (p<0.05). Conclusion Cell phone emissions have a negative impact on exposed sperm motility index, sperm acrosin activity, sperm DNA fragmentation and seminal CLU gene expression, especially in OAT cases. PMID:25918601

  6. Catalyst activator

    DOEpatents

    McAdon, Mark H.; Nickias, Peter N.; Marks, Tobin J.; Schwartz, David J.

    2001-01-01

    A catalyst activator particularly adapted for use in the activation of metal complexes of metals of Group 3-10 for polymerization of ethylenically unsaturated polymerizable monomers, especially olefins, comprising two Group 13 metal or metalloid atoms and a ligand structure including at least one bridging group connecting ligands on the two Group 13 metal or metalloid atoms.

  7. Outdoor Activities.

    ERIC Educational Resources Information Center

    Minneapolis Independent School District 275, Minn.

    Twenty-four activities suitable for outdoor use by elementary school children are outlined. Activities designed to make children aware of their environment include soil painting, burr collecting, insect and pond water collecting, studies of insect galls and field mice, succession studies, and a model of natural selection using dyed toothpicks. A…

  8. Physical activity

    MedlinePlus

    ... activity -- which includes an active lifestyle and routine exercise -- plus eating well, is the best way to stay healthy. ... goal. Your goal might be to: Manage a health condition Reduce stress ... other benefits, such as: Better control of your weight and ...

  9. Astronomy Activities.

    ERIC Educational Resources Information Center

    Greenstone, Sid

    This document consists of activities and references for teaching astronomy. The activities (which include objectives, list of materials needed, and procedures) focus on: observing the Big Dipper and locating the North Star; examining the Big Dipper's stars; making and using an astrolabe; examining retograde motion of Mars; measuring the Sun's…

  10. Activated Charcoal

    MedlinePlus

    ... is used to treat poisonings, reduce intestinal gas (flatulence), lower cholesterol levels, prevent hangover, and treat bile ... lower cholesterol levels in the blood. Decreasing gas (flatulence). Some studies show that activated charcoal is effective ...

  11. Activity Theory.

    ERIC Educational Resources Information Center

    Koschmann, Timothy; Roschelle, Jeremy; Nardi, Bonnie A.

    1998-01-01

    Includes three articles that discuss activity theory, based on "Context and Consciousness." Topics include human-computer interaction; computer interfaces; hierarchical structuring; mediation; contradictions and development; failure analysis; and designing educational technology. (LRW)

  12. Galactosyl prodrug of palmitoylethanolamide: synthesis, stability, cell permeation and cytoprotective activity.

    PubMed

    Luongo, Elvira; Russo, Roberto; Avagliano, Carmen; Santoro, Anna; Melisi, Daniela; Orefice, Nicola Salvatore; Raso, Giuseppina Mattace; Meli, Rosaria; Magliocca, Salvatore; Nieddu, Maria; Santiago, Gilvandete Maria Pinheiro; Boatto, Gianpiero; Calignano, Antonio; Rimoli, Maria Grazia

    2014-10-01

    N-Palmitoylethanolamide (PEA) is emerging as a novel therapeutic agent in the treatment of neuropathic pain and neurodegenerative diseases. Unfortunately, PEA poorly reaches the central nervous system (CNS), after peripheral administration, since it is inactivated through intracellular hydrolysis by lipid amidases. Since prodrug approach is one of the most popular methods used to increase cell permeability, the aim of this paper consists in the synthesis of a new galactosyl prodrug of PEA, the palmitoylethanolamide-succinamyl-D-galactos-6'-yl ester (PEAGAL). Biological experiments both in neuroblastoma and in C6 glioma cells, together with quantitative analyses performed through a LC-MS-MS technique, demonstrate the better efficacy of PEAGAL compared to PEA and its higher cell permeation. Our results encourage further experiments in animal models of neuropathic pain and of neurological disorders and/or neurodegenerative diseases, in order to promote a more effective peripherally administrated derivative of PEA.

  13. Metabolism of benzonitrile and butyronitrile by Klebsiella pneumoniae

    SciTech Connect

    Nawaz, M.S.; Heinze, T.M.; Cerniglia, C.E. )

    1992-01-01

    A strain of Klebsiella pneumoniae that used aliphatic nitriles as the sole source of nitrogen was adapted to benzonitrile as the sole source of carbon and nitrogen. Gas chromatographic and mass spectral analyses of culture filtrates indicated that K. pneumoniae metabolized 8.4 mM benzonitrile to 4.0 mM benzoic acid and 2.7 mM ammonia. In addition, butyronitrile was metabolized to butyramide and ammonia. The isolate also degraded mixtures of benzonitrile and aliphatic nitriles. Cell extracts contained nitrile hydratase and amidase activities. The enzyme activities were higher with butyronitrile and butyramide than with benzonitrile and benzamide, and amidase activities were twofold higher than nitrile hydratase activities. K. pneumoniae appears promising for the bioremediation of sites contaminated with aliphatic and aromatic nitriles.

  14. Plant metacaspase activation and activity.

    PubMed

    Minina, Elena A; Stael, Simon; Van Breusegem, Frank; Bozhkov, Peter V

    2014-01-01

    Metacaspases are essential for cell death regulation in plants. Further understanding of biochemistry of metacaspases and their molecular function in plant biology requires a set of robust methods for detection of metacaspase activation and quantitative analysis of corresponding proteolytic activity. Here we describe methods for purification of recombinant metacaspases, measurement of enzymatic activity of recombinant and endogenous metacaspases in vitro and in cell lysates, respectively, and finally detection of metacaspase activation in vivo. Additionally, an in vitro metacaspase protein substrate cleavage assay based on the cell-free production of substrate protein followed by proteolysis with recombinant metacaspase is presented. These methods have been originally developed for type II metacaspases from Arabidopsis and Norway spruce (Picea abies), but they can be used as templates for type I metacaspases, as well as for type II metacaspases from other species.

  15. Active colloids

    NASA Astrophysics Data System (ADS)

    Aranson, Igor S.

    2013-01-01

    A colloidal suspension is a heterogeneous fluid containing solid microscopic particles. Colloids play an important role in our everyday life, from food and pharmaceutical industries to medicine and nanotechnology. It is useful to distinguish two major classes of colloidal suspensions: equilibrium and active, i.e., maintained out of thermodynamic equilibrium by external electric or magnetic fields, light, chemical reactions, or hydrodynamic shear flow. While the properties of equilibrium colloidal suspensions are fairly well understood, active colloids pose a formidable challenge, and the research is in its early exploratory stage. One of the most remarkable properties of active colloids is the possibility of dynamic self-assembly, a natural tendency of simple building blocks to organize into complex functional architectures. Examples range from tunable, self-healing colloidal crystals and membranes to self-assembled microswimmers and robots. Active colloidal suspensions may exhibit material properties not present in their equilibrium counterparts, e.g., reduced viscosity and enhanced self-diffusivity, etc. This study surveys the most recent developments in the physics of active colloids, both in synthetic and living systems, with the aim of elucidation of the fundamental physical mechanisms governing self-assembly and collective behavior.

  16. Active microwaves

    NASA Technical Reports Server (NTRS)

    Evans, D.; Vidal-Madjar, D.

    1994-01-01

    Research on the use of active microwaves in remote sensing, presented during plenary and poster sessions, is summarized. The main highlights are: calibration techniques are well understood; innovative modeling approaches have been developed which increase active microwave applications (segmentation prior to model inversion, use of ERS-1 scatterometer, simulations); polarization angle and frequency diversity improves characterization of ice sheets, vegetation, and determination of soil moisture (X band sensor study); SAR (Synthetic Aperture Radar) interferometry potential is emerging; use of multiple sensors/extended spectral signatures is important (increase emphasis).

  17. Activated Sludge.

    ERIC Educational Resources Information Center

    Saunders, F. Michael

    1978-01-01

    Presents the 1978 literature review of wastewater treatment. This review covers: (1) activated sludge process; (2) process control; (3) oxygen uptake and transfer; (4) phosphorus removal; (5) nitrification; (6) industrial wastewater; and (7) aerobic digestion. A list of 136 references is also presented. (HM)

  18. Activities: Spirolaterals.

    ERIC Educational Resources Information Center

    Brannan, Richard; McFadden, Scott

    1981-01-01

    A set of activities designed to help students discover properties about order-3 spirolaterals on square grid paper is presented. The materials are prepared on worksheets designed for easy duplication. The lessons can lead to investigations involving spirolaterals of many other orders and shapes. (MP)

  19. Leaf Activities.

    ERIC Educational Resources Information Center

    Mingie, Walter

    Leaf activities can provide a means of using basic concepts of outdoor education to learn in elementary level subject areas. Equipment needed includes leaves, a clipboard with paper, and a pencil. A bag of leaves may be brought into the classroom if weather conditions or time do not permit going outdoors. Each student should pick a leaf, examine…

  20. Learning Activities.

    ERIC Educational Resources Information Center

    Tipton, Tom, Ed.

    1983-01-01

    Presents a flow chart for naming inorganic compounds. Although it is not necessary for students to memorize rules, preliminary skills needed before using the chart are outlined. Also presents an activity in which the mass of an imaginary atom is determined using lead shot, Petri dishes, and a platform balance. (JN)

  1. Activity report

    SciTech Connect

    Yu, S W

    2008-08-11

    This report is aimed to show the author's activities to support the LDRD. The title is 'Investigation of the Double-C Behavior in the Pu-Ga Time-Temperature-Transformation Diagram' The sections are: (1) Sample Holder Test; (2) Calculation of x-ray diffraction patterns; (3) Literature search and preparing publications; (4) Tasks Required for APS Experiments; and (5) Communications.

  2. Identification of bovine sperm acrosomal proteins that interact with a 32-kDa acrosomal matrix protein.

    PubMed

    Nagdas, Subir K; Smith, Linda; Medina-Ortiz, Ilza; Hernandez-Encarnacion, Luisa; Raychoudhury, Samir

    2016-03-01

    Mammalian fertilization is accomplished by the interaction between sperm and egg. Previous studies from this laboratory have identified a stable acrosomal matrix assembly from the bovine sperm acrosome termed the outer acrosomal membrane-matrix complex (OMC). This stable matrix assembly exhibits precise binding activity for acrosin and N-acetylglucosaminidase. A highly purified OMC fraction comprises three major (54, 50, and 45 kDa) and several minor (38-19 kDa) polypeptides. The set of minor polypeptides (38-19 kDa) termed "OMCrpf polypeptides" is selectively solubilized by high-pH extraction (pH 10.5), while the three major polypeptides (55, 50, and 45 kDa) remain insoluble. Proteomic identification of the OMC32 polypeptide (32 kDa polypeptide isolated from high-pH soluble fraction of OMC) yielded two peptides that matched the NCBI database sequence of acrosin-binding protein. Anti-OMC32 recognized an antigenically related family of polypeptides (OMCrpf polypeptides) in the 38-19-kDa range with isoelectric points ranging between 4.0 and 5.1. Other than glycohydrolases, OMC32 may also be complexed to other acrosomal proteins. The present study was undertaken to identify and localize the OMC32 binding polypeptides and to elucidate the potential role of the acrosomal protein complex in sperm function. OMC32 affinity chromatography of a detergent-soluble fraction of bovine cauda sperm acrosome followed by mass spectrometry-based identification of bound proteins identified acrosin, lactadherin, SPACA3, and IZUMO1. Co-immunoprecipitation analysis also demonstrated the interaction of OMC32 with acrosin, lactadherin, SPACA3, and IZUMO1. Our immunofluorescence studies revealed the presence of SPACA3 and lactadherin over the apical segment, whereas IZUMO1 is localized over the equatorial segment of Triton X-100 permeabilized cauda sperm. Immunoblot analysis showed that a significant portion of SPACA3 was released after the lysophosphatidylcholine (LPC)-induced acrosome

  3. Identification of Bovine Sperm Acrosomal Proteins that Interact with a 32kDa Acrosomal Matrix Protein

    PubMed Central

    Nagdas, Subir K; Smith, Linda; Medina-Ortiz, Ilza; Hernandez-Encarnacion, Luisa; Raychoudhury, Samir

    2016-01-01

    Mammalian fertilization is accomplished by the interaction between sperm and egg. Previous studies from this laboratory have identified a stable acrosomal matrix assembly from the bovine sperm acrosome termed the outer acrosomal membrane-matrix complex (OMC). This stable matrix assembly exhibits precise binding activity for acrosin and N-acetylglucosaminidase. A highly purified OMC fraction is comprised of three major (54, 50, and 45kDa) and several minor (38–19kDa) polypeptides. The set of minor polypeptides (38–19kDa) termed “OMCrpf polypeptides” is selectively solubilized by high-pH extraction (pH 10.5) while the three major polypeptides (55, 50 and 45kDa) remain insoluble. Proteomic identification of the OMC32 polypeptide (32kDa polypeptide isolated from high-pH soluble fraction of OMC) yielded two peptides that matched the NCBI database sequence of acrosin-binding protein. Anti-OMC32 recognized an antigenically related family of polypeptides (OMCrpf polypeptides) in the 38–19kDa range with isoelectric points ranging between 4.0 and 5.1. Other than glycohydrolases, OMC32 may also be complexed to other acrosomal proteins. The present study was undertaken to identify and localize the OMC32 binding polypeptides and to elucidate the potential role of the acrosomal protein complex in sperm function. OMC32 affinity chromatography of a detergent soluble fraction of bovine cauda sperm acrosome followed by mass spectrometry-based identification of bound proteins identified acrosin, lactadherin, SPACA3, and IZUMO1. Co-immunoprecipitation analysis also demonstrated the interaction of OMC32 with acrosin, lactadherin, SPACA3, and IZUMO1. Our immunofluorescence studies revealed the presence of SPACA3 and lactadherin over the apical segment; whereas, IZUMO1 is localized over the equatorial segment of Triton X-100 permeabilized cauda sperm. Immunoblot analysis showed that a significant portion of SPACA3 was released after the lysophosphatidyl choline (LPC

  4. Antimicrobial Activity.

    PubMed

    2016-01-01

    Natural products of higher plants may possess a new source of antimicrobial agents with possibly novel mechanisms of action. They are effective in the treatment of infectious diseases while simultaneously mitigating many of the side effects that are often associated with conventional antimicrobials. A method using scanning electron microscope (SEM) to study the morphology of the bacterial and fungal microbes and thus determining antimicrobial activity is presented in the chapter.

  5. Analgesic Activity.

    PubMed

    2016-01-01

    Analgesics are agents which selectively relieve pain by acting in the CNS and peripheral pain mediators without changing consciousness. Analgesics may be narcotic or non-narcotic. The study of pain in animals raises ethical, philosophical, and technical problems. Both peripheral and central pain models are included to make the test more evident for the analgesic property of the plant. This chapter highlights methods such as hot plate and formalin and acetic acid-induced pain models to check the analgesic activity of medicinal plants.

  6. Active packaging with antifungal activities.

    PubMed

    Nguyen Van Long, N; Joly, Catherine; Dantigny, Philippe

    2016-03-02

    There have been many reviews concerned with antimicrobial food packaging, and with the use of antifungal compounds, but none provided an exhaustive picture of the applications of active packaging to control fungal spoilage. Very recently, many studies have been done in these fields, therefore it is timely to review this topic. This article examines the effects of essential oils, preservatives, natural products, chemical fungicides, nanoparticles coated to different films, and chitosan in vitro on the growth of moulds, but also in vivo on the mould free shelf-life of bread, cheese, and fresh fruits and vegetables. A short section is also dedicated to yeasts. All the applications are described from a microbiological point of view, and these were sorted depending on the name of the species. Methods and results obtained are discussed. Essential oils and preservatives were ranked by increased efficacy on mould growth. For all the tested molecules, Penicillium species were shown more sensitive than Aspergillus species. However, comparison between the results was difficult because it appeared that the efficiency of active packaging depended greatly on the environmental factors of food such as water activity, pH, temperature, NaCl concentration, the nature, the size, and the mode of application of the films, in addition to the fact that the amount of released antifungal compounds was not constant with time.

  7. Mycobacteriophage Endolysins: Diverse and Modular Enzymes with Multiple Catalytic Activities

    PubMed Central

    Payne, Kimberly M.; Hatfull, Graham F.

    2012-01-01

    The mycobacterial cell wall presents significant challenges to mycobacteriophages – viruses that infect mycobacterial hosts – because of its unusual structure containing a mycolic acid-rich mycobacterial outer membrane attached to an arabinogalactan layer that is in turn linked to the peptidoglycan. Although little is known about how mycobacteriophages circumvent these barriers during the process of infection, destroying it for lysis at the end of their lytic cycles requires an unusual set of functions. These include Lysin B proteins that cleave the linkage of mycolic acids to the arabinogalactan layer, chaperones required for endolysin delivery to peptidoglycan, holins that regulate lysis timing, and the endolysins (Lysin As) that hydrolyze peptidoglycan. Because mycobacterial peptidoglycan contains atypical features including 3→3 interpeptide linkages, it is not surprising that the mycobacteriophage endolysins also have non-canonical features. We present here a bioinformatic dissection of these lysins and show that they are highly diverse and extensively modular, with an impressive number of domain organizations. Most contain three domains with a novel N-terminal predicted peptidase, a centrally located amidase, muramidase, or transglycosylase, and a C-terminal putative cell wall binding domain. PMID:22470512

  8. Active tectonics

    SciTech Connect

    Not Available

    1986-01-01

    This study is part of a series of Studies in Geophysics that have been undertaken for the Geophysics Research Forum by the Geophysics Study Committee. One purpose of each study is to provide assessments from the scientific community to aid policymakers in decisions on societal problems that involve geophysics. An important part of such assessments is an evaluation of the adequacy of current geophysical knowledge and the appropriateness of current research programs as a source of information required for those decisions. The study addresses our current scientific understanding of active tectonics --- particularly the patterns and rates of ongoing tectonic processes. Many of these processes cannot be described reasonably using the limited instrumental or historical records; however, most can be described adequately for practical purposes using the geologic record of the past 500,000 years. A program of fundamental research focusing especially on Quaternary tectonic geology and geomorphology, paleoseismology, neotectonics, and geodesy is recommended to better understand ongoing, active tectonic processes. This volume contains 16 papers. Individual papers are indexed separately on the Energy Database.

  9. Isolation and characterization of an ovoinhibitor, a multidomain Kazal-like inhibitor from Turkey (Meleagris gallopavo) seminal plasma.

    PubMed

    Słowińska, Mariola; Liszewska, Ewa; Nynca, Joanna; Bukowska, Joanna; Hejmej, Anna; Bilińska, Barbara; Szubstarski, Jarosław; Kozłowski, Krzysztof; Jankowski, Jan; Ciereszko, Andrzej

    2014-11-01

    Turkey seminal plasma contains three serine proteinase inhibitors. Two of them, with low molecular masses (6 kDa), were identified as single-domain Kazal-type inhibitors responsible for regulating acrosin activity. Our experimental objective was to isolate and characterize the inhibitor with the high molecular weight from turkey seminal plasma. The inhibitor was purified using hydrophobic interaction and affinity chromatography. Pure preparations of the inhibitor were used for identification by mass spectrometry, for determination of physicochemical properties (molecular weight, pI, and content and composition of the carbohydrate component), for kinetic studies, and for antibacterial tests. Gene expression and immunohistochemical detection of the inhibitor were analyzed in the testis, epididymis, and ductus deferens. The inhibitor with a high molecular weight from turkey seminal plasma was identified as an ovoinhibitor, which was found in avian semen for the first time. The turkey seminal plasma ovoinhibitor was a six-tandem homologous Kazal-type domain serine proteinase inhibitor that targeted multiple proteases, including subtilisin, trypsin, and elastase, but not acrosin. Our results suggested that hepatocyte growth factor activator was a potential target proteinase for the ovoinhibitor in turkey seminal plasma. The presence of the ovoinhibitor within the turkey reproductive tract suggested that its role was to maintain a microenvironment for sperm in the epididymis and ductus deferens. The turkey seminal plasma ovoinhibitor appeared to play a significant role in an antibacterial semen defense against Bacillus subtilis and Staphylococcus aureus.

  10. An ATP-binding cassette transporter-like complex governs cell-wall hydrolysis at the bacterial cytokinetic ring.

    PubMed

    Yang, Desirée C; Peters, Nick T; Parzych, Katherine R; Uehara, Tsuyoshi; Markovski, Monica; Bernhardt, Thomas G

    2011-11-08

    ATP-binding cassette transporters are ubiquitous membrane protein complexes that move substrates across membranes. They do so using ATP-induced conformational changes in their nucleotide-binding domains to alter the conformation of the transport cavity formed by their transmembrane domains. In Escherichia coli, an ATP-binding cassette transporter-like complex composed of FtsE (nucleotide-binding domain) and FtsX (transmembrane domain) has long been known to be important for cytokinesis, but its role in the process has remained mysterious. Here we identify FtsEX as a regulator of cell-wall hydrolysis at the division site. Cell-wall material synthesized by the division machinery is shared initially by daughter cells and must be split by hydrolytic enzymes called "amidases" to drive daughter-cell separation. We recently showed that the amidases require activation at the cytokinetic ring by proteins with LytM domains, of which EnvC is the most critical. In this report, we demonstrate that FtsEX directly recruits EnvC to the septum via an interaction between EnvC and a periplasmic loop of FtsX. Importantly, we also show that FtsEX variants predicted to be ATPase defective still recruit EnvC to the septum but fail to promote cell separation. Our results thus suggest that amidase activation via EnvC in the periplasm is regulated by conformational changes in the FtsEX complex mediated by ATP hydrolysis in the cytoplasm. Since FtsE has been reported to interact with the tubulin-like FtsZ protein, our model provides a potential mechanism for coupling amidase activity with the contraction of the FtsZ cytoskeletal ring.

  11. Recombinant expression of a putative prophage amidase cloned from the genome of Listeria monocytogenes that lyses the bacterium and its biofilm

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Listeria monocytogenes is a Gram-positive, non-sporeforming, catalase-positive rod that is a major bacterial food-borne disease agent, causing listeriosis. Listeria can be associated with uncooked meats including poultry, uncooked vegetables, soft cheeses and unpasteurized milk. The bacterium can be...

  12. Recombinant Expression of a Genome-encoded N-acetylmuramoyl-L-alanine Amidase that Synergistically Lyses Listeria monocytogenes Biofilms with a Protease

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Listeria monocytogenes plays a significant role in human food-borne disease caused by eating food contaminated with the bacterium and although incidence is low it is a leading cause of life-threatening, bacterial food-borne disease in humans. L. monocytogenes serotypes 1/2a and 4b can form mixed-cu...

  13. Expression of a Clostridium perfringens genome-encoded putative N-acetylmuramoyl-L-alanine amidase as a potential antimicrobial to control the bacterium

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Clostridium perfringens is a Gram-positive, spore-forming anaerobic bacterium that plays a substantial role in non-foodborne human, animal and avian diseases as well as human foodborne disease. Previously discovered C. perfringens bacteriophage lytic enzyme amino acid sequences were utilized to iden...

  14. IASS Activity

    NASA Astrophysics Data System (ADS)

    Hojaev, Alisher S.; Ibragimova, Elvira M.

    2015-08-01

    It’s well known, astronomy in Uzbekistan has ancient roots and traditions (e.g., Mirzo Ulugh Beg, Abū al-Rayhān al-Bīrūnī, Abū ‘Abdallāh al-Khwārizmī) and astronomical heritage carefully preserved. Nowadays uzbek astronomers play a key role in scientific research but also in OAD and Decadal Plan activity in the Central Asia region. International Aerospace School (IASS) is an amazing and wonderful event held annually about 30 years. IASS is unique project in the region, and at the beginning we spent the Summer and Winter Schools. At present in the summer camp we gather about 50 teenage and undergraduate students over the country and abroad (France, Malaysia, Turkey, Azerbaijan, Pakistan, Russia, etc.). They are selected on the basis of tests of astronomy and space issues. During two weeks of IASS camp the invited scientists, cosmonauts and astronauts as well as other specialists give lectures and engage in practical exercises with IASS students in astronomy, including daily observations of the Sun and night sky observations with meniscus telescope, space research and exploration, aerospace modelling, preparation and presentation of original projects. This is important that IASS gives not theoretical grounds only but also practically train the students and the hands-on training is the major aims of IASS. Lectures and practice in the field of astronomy carried out with the direct involvement and generous assistance of Uranoscope Association (Paris, France). The current 26-th IASS is planned to held in July 2015.

  15. Physical Activity (Exercise)

    MedlinePlus

    ... Physical activity (exercise) fact sheet ePublications Physical activity (exercise) fact sheet How can physical activity improve my ... recent hip surgery More information on physical activity (exercise) For more information about physical activity (exercise), call ...

  16. The two-component cell lysis genes holWMY and lysWMY of the Staphylococcus warneri M phage varphiWMY: cloning, sequencing, expression, and mutational analysis in Escherichia coli.

    PubMed

    Yokoi, Ken-Ji; Kawahigashi, Nobutaka; Uchida, Maiko; Sugahara, Kazuki; Shinohara, Masayuki; Kawasaki, Ken-Ichi; Nakamura, Shogo; Taketo, Akira; Kodaira, Ken-Ichi

    2005-05-23

    From the genome library of Staphylococcus warneri M, the two successive cell-lysis genes (holWMY and lytWMY) were cloned and characterized. The lytWMY gene encoded a protein (LysWMY), whose calculated molecular mass and pI were 54 kDa and 8.95, respectively. When overproduced in Escherichia coli, lysWMY directed a protein of 45 kDa (smaller than the predicted molecular mass), having N-terminal 13 residues identical with those predicted from DNA. Comparative analysis revealed that LysWMY significantly resembles the putative N-acetylmuramoyl-L-alanine amidases encoded by the staphylococcal phages phi11, 80 alpha, and Twort. Examination of modular organization of LysWMY identified three putative domains CHAP (for D-alanyl-glycyl endopeptidase), amidase (L-muramoyl-L-alanine amidase), and SH3 (cell wall recognition). Gene knockout analysis revealed that each of the two domains of CHAP and amidase was responsible for cell-lytic activity on a zymogram gel. Site-directed mutation of Cys29Ala, His92Ala, or Asn114Ala in the CHAP domain substantially reduced cell-lytic activity, suggesting that this Cys-His-Asn triad is crucial for the enzymatic function. On the other hand, the holWMY gene encoded a protein (HolWMY) with molecular mass and pI of 16 kDa and 4.36; this protein contained two potential transmembrane helices, resembling other predicted holins (a cytoplasmic membrane-disrupting protein) encoded by the S. aureus phage, phi11, 80 alpha, and Twort. Upon mitomycin C exposure of S. warneri M, a prophage (phiWMY) was induced and the virion was examined under electron microscopy. PCR amplification and sequencing revealed the presence of the holWMY-lysWMY genes in the phage genome.

  17. Diisopropyl fluorophosphate labeling of sperm-associated proteinases

    SciTech Connect

    Odem, R.R.; Willand, J.L.; Polakoski, K.L. )

    1990-02-01

    Proteinase inhibitors have been shown to be capable of preventing various aspects of fertilization. Diisopropyl fluorophosphate (DFP) is an irreversible inhibitor of trypsin-like enzymes that is commercially available in a radiolabeled form. The experiments described herein were designed to determine if DFP would prevent sperm function in live, motile sperm and to identify the sperm proteins bound with DFP. DFP at 5 mM concentrations had no observable effect on sperm motility, but inhibited the penetration of zona-free hamster ova by human sperm (5.5%) compared to controls (33.5%). Acid extracts of motile sperm that had been incubated with radiolabeled DFP and collected by the swim-up procedure demonstrated the presence of radiolabeled DFP, and the autoradiography of the sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) gels of these extracts localized the uptake of radiolabeled DFP to proteins in the molecular weight region of the proacrosin-acrosin system. Acid-extracted proteinases from semen samples incubated with DFP demonstrated a concentration-dependent inhibition of both esterolytic hydrolysis of benzoyl-arginine ethyl ester on spectrophotometric analysis and proteolytic activity on gelatin SDS-PAGE zymography. DFP-labeled proteins were precipitated by highly specific antibodies to proacrosin. These results demonstrated that DFP is capable of inhibiting sperm function, and that it associates with the proacrosin-acrosin system in live motile sperm.

  18. A mechanism for differential release of acrosomal enzymes during the acrosome reaction.

    PubMed Central

    Hardy, D M; Oda, M N; Friend, D S; Huang, T T

    1991-01-01

    To study the organization of fertilization enzymes in the sperm acrosome, we isolated and characterized two physicochemically distinct acrosomal fractions of guinea-pig spermatozoa. A soluble fraction contained the 25,000-Mr acrosomal autoantigen, AA1, and most of the acrosomal hyaluronidase and dipeptidyl peptidase II activity. A particulate fraction, designated acrosomal matrix (AM), consisted of membraneless crescent-shaped structures, and contained most of the acrosomal proacrosin. The AM also contained a 28,000-Mr putative proacrosin-binding protein, and a very-high-Mr component which, on reduction, was dissociated into 48,000-Mr and 67,000-Mr subunits. Autoproteolytic dissolution of the AM correlated with proteolysis by acrosin of the 28,000-Mr and 48,000-Mr AM molecules. Components of both the AM and the soluble fraction were localized by immuno-electron microscopy to the electron-dense region of the guinea-pig sperm acrosome. We conclude that acrosomal molecules are segregated into soluble and matrix compartments. This segregation is a function of disulphide bonding and non-covalent interactions among the relatively few components of the AM. Association of acrosin with the AM may be the mechanism by which this enzyme's release from the spermatozoon during the acrosome reaction is delayed relative to the release of other acrosomal molecules. Images Fig. 1. Fig. 2. Fig. 3. Fig. 4. Fig. 5. Fig. 6. Fig. 7. Fig. 8. PMID:1903927

  19. A new acylamidase from Rhodococcus erythropolis TA37 can hydrolyze N-substituted amides.

    PubMed

    Lavrov, K V; Zalunin, I A; Kotlova, E K; Yanenko, A S

    2010-08-01

    A new acylamidase was isolated from Rhodococcus erythropolis TA37 and characterized. N-Substituted acrylamides (isopropyl acrylamide, N,N-dimethyl-aminopropyl acrylamide, and methylene-bis-acrylamide), acid para-nitroanilides (4'-nitroacetanilide, Gly-pNA, Ala-pNA, Leu-pNA), and N-acetyl derivatives of glycine, alanine, and leucine are good substrates for this enzyme. Aliphatic amides (acetamide, acrylamide, isobutyramide, n-butyramide, and valeramide) are also used as substrates but with less efficiency. The enzyme subunit mass by SDS-PAGE is 55 kDa. Maximal activity is exhibited at pH 7-8 and 55°C. The enzyme is stable for 15 h at 22°C and for 0.5 h at 45°C. The Michaelis constant (K(m)) is 0.25 mM with Gly-pNA and 0.55 mM with Ala-pNA. The acylamidase activity is suppressed by inhibitors of serine proteases (phenylmethylsulfonyl fluoride and diisopropyl fluorophosphate) but is not suppressed by inhibitors of aliphatic amidases (acetaldehyde and nitrophenyl disulfides). The N-terminal amino acid sequence of the acylamidase is highly homologous to those of two putative amidases detected from sequenced R. erythropolis genomes. It is suggested that the acylamidase together with the detected homologs forms a new class within the amidase signature family.

  20. Activation Energy

    NASA Technical Reports Server (NTRS)

    Gadeken, Owen

    2002-01-01

    Teaming is so common in today's project management environment that most of us assume it comes naturally. We further assume that when presented with meaningful and challenging work, project teams will naturally engage in productive activity to complete their tasks. This assumption is expressed in the simple (but false) equation: Team + Work = Teamwork. Although this equation appears simple and straightforward, it is far from true for most project organizations whose reality is a complex web of institutional norms based on individual achievement and rewards. This is illustrated by the very first successful team experience from my early Air Force career. As a young lieutenant, I was sent to Squadron Officer School, which was the first in the series of Air Force professional military education courses I was required to complete during my career. We were immediately formed into teams of twelve officers. Much of the course featured competition between these teams. As the most junior member of my team, I quickly observed the tremendous pressure to show individual leadership capability. At one point early in the course, almost everyone in our group was vying to become the team leader. This conflict was so intense that it caused us to fail miserably in our first outdoor team building exercise. We spent so much time fighting over leadership that we were unable to complete any of the events on the outdoor obstacle course. This complete lack of success was so disheartening to me that I gave our team little hope for future success. What followed was a very intense period of bickering, conflict, and even shouting matches as our dysfunctional team tried to cope with our early failures and find some way to succeed. British physician and researcher Wilfred Bion (Experiences in Groups, 1961) discovered that there are powerful psychological forces inherent in all groups that divert from accomplishing their primary tasks. To overcome these restraining forces and use the potential

  1. Staying Active: Physical Activity and Exercise

    MedlinePlus

    ... How much physical activity should I do each week? The Centers for Disease Control and Prevention recommend ... 150 minutes of moderate-intensity aerobic activity a week, along with muscle-strengthening activities on 2 days ...

  2. Adolescent sexual activity.

    PubMed

    Braverman, P K; Strasburger, V C

    1993-11-01

    Adolescents are becoming sexually active at younger ages. One half of the adolescents in the United States are sexually active. This article reviews adolescent sexual activity, including rates of sexual activity, sexual practices, gay and lesbian youth, and factors affecting the initiation of sexual activity. In addition, adolescent pregnancy, with possible outcomes and effects on teen parents and their offspring, is discussed.

  3. Guide to Physical Activity

    MedlinePlus

    ... Families ( We Can! ) Health Professional Resources Guide to Physical Activity Physical activity is an important part of your ... to injury. Examples of moderate-intensity amounts of physical activity Common Chores Washing and waxing a car for ...

  4. Physical Activity Assessment

    Cancer.gov

    Current evidence convincingly indicates that physical activity reduces the risk of colon and breast cancer. Physical activity may also reduce risk of prostate cancer. Scientists are also evaluating potential relationships between physical activity and other cancers.

  5. Political activity for physical activity: health advocacy for active transport

    PubMed Central

    2011-01-01

    Effective health advocacy is a priority for efforts to increase population participation in physical activity. Local councils are an important audience for this advocacy. The aim of the current study was to describe features of advocacy for active transport via submissions to city council annual plans in New Zealand, and the impact of an information sheet to encourage the health sector to be involved in this process. Written submissions to city council's annual consultation process were requested for 16 city councils over the period of three years (2007/08, 2008/09, and 2009/10). Submissions were reviewed and categories of responses were created. An advocacy information sheet encouraging health sector participation and summarising some of the evidence-base related to physical activity, active transport and health was released just prior to the 2009/10 submission time. Over the period of the study, city councils received 47,392 submissions, 17% of which were related to active transport. Most submissions came from city residents, with a small proportion (2%) from the health sector. The largest category of submissions was in support of pedestrian and cycling infrastructure, design and maintenance of facilities and additional features to support use of these transport modes. Health arguments featured prominently in justifications for active transport initiatives, including concerns about injury risk, obesity, physical inactivity, personal safety and facilities for people with disabilities. There was evidence that the information sheet was utilised by some health sector submitters (12.5%), providing tentative support for initiatives of this nature. In conclusion, the study provides novel information about the current nature of health advocacy for active transport and informs future advocacy efforts about areas for emphasis, such as health benefits of active transport, and potential alliances with other sectors such as environmental sustainability, transport and urban

  6. Home Activities for Fours.

    ERIC Educational Resources Information Center

    Ferguson-Florissant School District, Ferguson, MO.

    These home learning activity guides have been developed for parents to use with their 4-year-old children. Most of the activities require only household items that are often thrown away and can be recycled for learning activities. Some require no materials at all. The guides frequently begin with a discussion of home activities; progress through…

  7. Active commuting to school

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Declines in physical activity levels have coincided with increasing rates of obesity in children. This is problematic because physical activity has been shown to attenuate weight gain in children. Active commuting to school is one way of increasing children's physical activity. However, given the hi...

  8. Civil Law: 12 Activities.

    ERIC Educational Resources Information Center

    Dresbach, Debra

    These learning activities on civil law are intended to supplement the secondary level Scholastic materials "Living Law." Case studies, simulations, and role-play activities are included. Information provided for each activity includes a brief overview, background information, teacher instructions and a description of each activity.…

  9. Increasing Youth Physical Activity with Activity Calendars

    ERIC Educational Resources Information Center

    Eckler, Seth

    2016-01-01

    Physical educators often struggle with ways to get their students to be active beyond the school day. One strategy to accomplish this is the use of physical activity calendars (PACs). The purpose of this article is to support the use of PACs and give practical advice for creating effective PACs.

  10. Protective effect of resveratrol on spermatozoa function in male infertility induced by excess weight and obesity

    PubMed Central

    Cui, Xiangrong; Jing, Xuan; Wu, Xueqing; Yan, Meiqin

    2016-01-01

    Male infertility is a complex, multifactorial and polygenic disease that contributes to ~50% cases of infertility. Previous studies have demonstrated that excess weight and obesity factors serve an important role in the development of male infertility. An increasing number of studies have reported that resveratrol may regulate the response of cells to specific stimuli that induce cell injury, as well as decrease germ cell apoptosis in mice or rats. In the present study, the semen quality and serum sex hormone levels were evaluated in 324 men, which included 73 underweight, 82 normal weight, 95 overweight and 74 obese men. All patients were referred to The Reproductive Medicine Center of Shanxi Women and Infants Hospital (Taiyuan, China) between January 2013 and January 2015. The aim of the present study was to investigate the effects of resveratrol treatment on the motility, plasma zinc concentration and acrosin activity of sperm from obese males. The sperm concentration, normal sperm morphology, semen volumes, DNA fragmentation rates and testosterone levels in men from the overweight and obese groups were markedly decreased when compared with men in the normal weight group. In addition, the progressive motility, seminal plasma zinc concentration and spermatozoa acrosin activity were notably decreased in the obese group compared with the normal weight group. However, estradiol levels were significantly increased in the overweight, obese and underweight groups compared with the normal weight group. Notably, semen samples from obese males with astenospermia treated with 0–100 µmol/l resveratrol for 30 min demonstrated varying degrees of improvement in sperm motility. When these semen samples were treated with 30 µmol/l resveratrol, sperm motility improved when compared to other doses of resveratrol. Therefore, 30 µmol/l resveratrol was selected for further experiments. Upon treatment of semen samples with resveratrol (30 µmol/l) for 30 min, the seminal plasma

  11. Protective effect of resveratrol on spermatozoa function in male infertility induced by excess weight and obesity.

    PubMed

    Cui, Xiangrong; Jing, Xuan; Wu, Xueqing; Yan, Meiqin

    2016-11-01

    Male infertility is a complex, multifactorial and polygenic disease that contributes to ~50% cases of infertility. Previous studies have demonstrated that excess weight and obesity factors serve an important role in the development of male infertility. An increasing number of studies have reported that resveratrol may regulate the response of cells to specific stimuli that induce cell injury, as well as decrease germ cell apoptosis in mice or rats. In the present study, the semen quality and serum sex hormone levels were evaluated in 324 men, which included 73 underweight, 82 normal weight, 95 overweight and 74 obese men. All patients were referred to The Reproductive Medicine Center of Shanxi Women and Infants Hospital (Taiyuan, China) between January 2013 and January 2015. The aim of the present study was to investigate the effects of resveratrol treatment on the motility, plasma zinc concentration and acrosin activity of sperm from obese males. The sperm concentration, normal sperm morphology, semen volumes, DNA fragmentation rates and testosterone levels in men from the overweight and obese groups were markedly decreased when compared with men in the normal weight group. In addition, the progressive motility, seminal plasma zinc concentration and spermatozoa acrosin activity were notably decreased in the obese group compared with the normal weight group. However, estradiol levels were significantly increased in the overweight, obese and underweight groups compared with the normal weight group. Notably, semen samples from obese males with astenospermia treated with 0‑100 µmol/l resveratrol for 30 min demonstrated varying degrees of improvement in sperm motility. When these semen samples were treated with 30 µmol/l resveratrol, sperm motility improved when compared to other doses of resveratrol. Therefore, 30 µmol/l resveratrol was selected for further experiments. Upon treatment of semen samples with resveratrol (30 µmol/l) for 30 min, the seminal

  12. Ascorbic acid, catalase and chlorpromazine reduce cryopreservation-induced damages to crossbred bull spermatozoa.

    PubMed

    Paudel, K P; Kumar, S; Meur, S K; Kumaresan, A

    2010-04-01

    The present study evaluated the effectiveness of ascorbic acid, catalase, chlorpromazine and their combinations in reducing the cryodamages to crossbred bull (Bos taurus x Bos indicus) spermatozoa. A total of 32 ejaculates (eight each from four bulls) were diluted in Tris-citric acid-fructose-egg yolk-glycerol extender. Each ejaculate was split into six parts (five treatment and one control). Treatment groups included 10 mm ascorbic acid, 0.1 mm chlorpromazine, 200 IU/ml catalase, 10 mm ascorbic acid + 0.1 mm chlorpromazine or 200 IU/ml catalase + 0.1 mm chlorpromazine in the extender. Fluorescent probes (Fluorescein isothiocyanate--Pisum sativum agglutinin + Propidium iodide) were used for the assessment of spermatozoa viability and acrosomal status. The proportion of acrosome intact live (AIL), acrosome intact dead, acrosome reacted live and acrosome reacted dead sperm was assessed in fresh, equilibrated and frozen-thawed semen. The functional status of the sperm was assessed using hypo-osmotic sperm swelling test (HOSST). Activities of acrosin and hyaluronidase enzyme were also determined. Lipid peroxidation level was assayed based on the melonaldehyde (MDA) production. In cryopreserved semen, the values of AIL spermatozoa, HOSST response, hyaluronidase and acrosin activity were reduced by 53%, 47%, 34% and 54%, respectively from their initial values in fresh semen. However, MDA level was threefold higher in the frozen-thawed sperm compared with fresh sperm. Significant (p < 0.05) improvement in motility, viability, HOSST response, retention of hyaluonidase and acrosin and reduction in MDA was recorded in ascorbic acid, catalase, ascorbic acid + chlorpromazine and catalase + chlorpromazine incorporated groups. The percentage of AIL sperm was significantly (p < 0.05) higher in ascorbic acid, catalase and ascorbic acid + chlorpromazine incorporated groups compared with the control. Chlorpromazine alone did not improve the post-thaw semen quality but when combined

  13. Cultural Activation of Consumers.

    PubMed

    Siegel, Carole E; Reid-Rose, Lenora; Joseph, Adriana M; Hernandez, Jennifer C; Haugland, Gary

    2016-02-01

    This column discusses "cultural activation," defined as a consumer's recognition of the importance of providing cultural information to providers about cultural affiliations, challenges, views about, and attitudes toward behavioral health and general medical health care, as well as the consumer's confidence in his or her ability to provide this information. An aid to activation, "Cultural Activation Prompts," and a scale that measures a consumer's level of activation, the Cultural Activation Measurement Scale, are described. Suggestions are made about ways to introduce cultural activation as a component of usual care.

  14. Smoking, physical activity, and active life expectancy.

    PubMed

    Ferrucci, L; Izmirlian, G; Leveille, S; Phillips, C L; Corti, M C; Brock, D B; Guralnik, J M

    1999-04-01

    The effect of smoking and physical activity on active and disabled life expectancy was estimated using data from the Established Populations for Epidemiologic Studies of the Elderly (EPESE). Population-based samples of persons aged > or = 65 years from the East Boston, Massachusetts, New Haven, Connecticut, and Iowa sites of the EPESE were assessed at baseline between 1981 and 1983 and followed for mortality and disability over six annual follow-ups. A total of 8,604 persons without disability at baseline were classified as "ever" or "never" smokers and doing "low," "moderate," or "high" level physical activity. Active and disabled life expectancies were estimated using a Markov chain model. Compared with smokers, men and women nonsmokers survived 1.6-3.9 and 1.6-3.6 years longer, respectively, depending on level of physical activity. When smokers were disabled and close to death, most nonsmokers were still nondisabled. Physical activity, from low to moderate to high, was significantly associated with more years of life expectancy in both smokers (9.5, 10.5, 12.9 years in men and 11.1, 12.6, 15.3 years in women at age 65) and nonsmokers (11.0, 14.4, 16.2 years in men and 12.7, 16.2, 18.4 years in women at age 65). Higher physical activity was associated with fewer years of disability prior to death. These findings provide strong and explicit evidence that refraining from smoking and doing regular physical activity predict a long and healthy life.

  15. Population Education. Awareness Activities.

    ERIC Educational Resources Information Center

    Brouse, Deborah E.

    1990-01-01

    Described are awareness activities that deal with human population growth, resources, and the environment. Activities include simulations, mathematical exercises, and discussions of the topic. Specific examples of what individuals can do to help are listed. (KR)

  16. Major operations and activities

    SciTech Connect

    Black, D.G.

    1995-06-01

    This section of the 1994 Hanford Site Environmental Report summarizes the major operations and activities on the site. These operations and activities include site management, waste management, environmental restoration and corrective actions, and research and technology development.

  17. Family Activities for Fitness

    ERIC Educational Resources Information Center

    Grosse, Susan J.

    2009-01-01

    This article discusses how families can increase family togetherness and improve physical fitness. The author provides easy ways to implement family friendly activities for improving and maintaining physical health. These activities include: walking, backyard games, and fitness challenges.

  18. Active magnetic regenerator

    DOEpatents

    Barclay, John A.; Steyert, William A.

    1982-01-01

    The disclosure is directed to an active magnetic regenerator apparatus and method. Brayton, Stirling, Ericsson, and Carnot cycles and the like may be utilized in an active magnetic regenerator to provide efficient refrigeration over relatively large temperature ranges.

  19. ACS Community Activities Contests

    NASA Astrophysics Data System (ADS)

    Burgener, Marisa

    2007-08-01

    The Committee on Community Activities and the Office of Community Activities announce the winners of the Illustrated Haiku Contest, Earth Day 2007 and the Poster Contest, National Chemistry Week 2006.

  20. Activity Theory and Ontology

    ERIC Educational Resources Information Center

    Peim, Nick

    2009-01-01

    This paper seeks to re-examine Yrio Engestrom's activity theory as a technology of knowledge designed to enable positive transformations of specific practices. The paper focuses on a key paper where Engestrom defines the nature and present state of activity theory. Beginning with a brief account of the relations between activity theory and…

  1. Measurement of Physical Activity.

    ERIC Educational Resources Information Center

    Dishman, Rod K.; Washburn, Richard A.; Schoeller, Dale A.

    2001-01-01

    Valid assessment of physical activity must be unobtrusive, practical to administer, and specific about physical activity type, frequency, duration, and intensity. Assessment methods can be categorized according to whether they provide direct or indirect (e.g., self-report) observation of physical activity, body motion, physiological response…

  2. Horticultural Practices. Activity Guides.

    ERIC Educational Resources Information Center

    Bania, Kent; Cummings, John, Ed.

    The 88 activity guides in this document are intended to supplement the initial or organized instruction of the agricultural teacher at the secondary educational level. Some of the activities require one student to complete, others may need two or more students working in a team. Some activities also require followup checking within a few days to…

  3. Highlights of 1981 activities

    NASA Technical Reports Server (NTRS)

    1981-01-01

    The highlights of NASA's 1981 activities are presented, including the results of the two flights of the space shuttle Columbia and the Voyager 2 encounter with Saturn. Accomplishments in the areas of space transportation operations; space science; aeronautical, energy, and space research and development; as well as space tracking, international activities, and 1981 launch activities are discussed.

  4. Bonus Activity Book.

    ERIC Educational Resources Information Center

    Learning, 1992

    1992-01-01

    Provides on-task activities to fill in unexpected extra moments in elementary classes. The activities require little preparation and take 5-15 minutes to complete. There are activities for math, language arts, social science, science, critical thinking, and computer. An outer space board game is also included. (SM)

  5. Activity Sheets. Draft Copy.

    ERIC Educational Resources Information Center

    Duke Power Company, Educational Services Dept., Charlotte, NC.

    This document consists of energy vocabulary activities, three games, worksheets, laboratory activities/exercises, and an introductory classroom exercise designed to introduce energy concepts to students. Vocabulary activities focus on coal and energy consumption. The three games (with instructions) focus on various aspects of energy and energy…

  6. Technology Learning Activities I.

    ERIC Educational Resources Information Center

    International Technology Education Association, Reston, VA.

    This guide contains 30 technology learning activities. Activities may contain all or some of the following: an introduction, objectives, materials and equipment, challenges, limitations, notes and investigations, resources and references used, and evaluation ideas. Activity titles are: (1) Occupations in Construction Technology; (2) Designing a…

  7. Technology Systems. Laboratory Activities.

    ERIC Educational Resources Information Center

    Brame, Ray; And Others

    This guide contains 43 modules of laboratory activities for technology education courses. Each module includes an instructor's resource sheet and the student laboratory activity. Instructor's resource sheets include some or all of the following elements: module number, course title, activity topic, estimated time, essential elements, objectives,…

  8. Computers + Student Activities Handbook.

    ERIC Educational Resources Information Center

    Masie, Elliott; Stein, Michele

    Designed to provide schools with the tools to start utilizing computers for student activity programs without additional expenditures, this handbook provides beginning computer users with suggestions and ideas for using computers in such activities as drama clubs, yearbooks, newspapers, activity calendars, accounting programs, room utilization,…

  9. Climate Change: An Activity.

    ERIC Educational Resources Information Center

    Lewis, Garry

    1995-01-01

    Presents a segment of the Geoscience Education booklet, Climate Change, that contains information and activities that enable students to gain a better appreciation of the possible effects human activity has on the Earth's climate. Describes the Terrace Temperatures activity that leads students through an investigation using foraminifera data to…

  10. Effect of estrogens on boar sperm capacitation in vitro

    PubMed Central

    2010-01-01

    Background Mammalian sperm must undergo a series of controlled molecular processes in the female reproductive tract called capacitation before they are capable of penetrating and fertilizing the egg. Capacitation, as a complex biological process, is influenced by many molecular factors, among which steroidal hormone estrogens play their role. Estrogens, present in a high concentration in the female reproductive tract are generally considered as primarily female hormones. However, there is increasing evidence of their important impact on male reproductive parameters. The purpose of this study is to investigate the effect of three natural estrogens such as estrone (E1), 17beta-estradiol (E2) and estriol (E3) as well as the synthetical one, 17alpha-ethynylestradiol (EE2) on boar sperm capacitation in vitro. Methods Boar sperm were capacitated in vitro in presence of estrogens. Capacitation progress in control and experimental samples was analyzed by flow cytometry with the anti-acrosin monoclonal antibody (ACR.2) at selected times of incubation. Sperm samples were analyzed at 120 min of capacitation by CTC (chlortetracycline) assay, immunocytochemistry and flow cytometry with anti-acrosin ACR.2 antibody. Furthermore, sperm samples and capacitating media were analyzed by immunocytochemistry, ELISA with the ACR.2 antibody, and the acrosin activity assay after induced acrosomal reaction (AR). Results Estrogens stimulate sperm capacitation of boar sperm collected from different individuals. The stimulatory effect depends on capacitation time and is highly influenced by differences in the response to estrogens such as E2 by individual animals. Individual estrogens have relatively same effect on capacitation progress. In the boar samples with high estrogen responsiveness, estrogens stimulate the capacitation progress in a concentration-dependent manner. Furthermore, estrogens significantly increase the number of acrosome-reacted sperm after zona pellucida- induced acrosomal

  11. Characterization of five novel endolysins from Gram-negative infecting bacteriophages.

    PubMed

    Walmagh, Maarten; Boczkowska, Barbara; Grymonprez, Barbara; Briers, Yves; Drulis-Kawa, Zuzanna; Lavigne, Rob

    2013-05-01

    We here characterize five globular endolysins, encoded by a set of Gram-negative infecting bacteriophages: BcepC6gp22 (Burkholderia cepacia phage BcepC6B), P2gp09 (Escherichia coli phage P2), PsP3gp10 (Salmonella enterica phage PsP3), K11gp3.5 and KP32gp15 (Klebsiella pneumoniae phages K11 and KP32, respectively). In silico, BcepC6gp22, P2gp10 and PsP3gp10 are predicted to possess lytic transglycosylase activity, whereas K11gp3.5 and KP32gp15 have putative amidase activity. All five endolysins show muralytic activity on the peptidoglycan of several Gram-negative bacterial species. In vitro, Pseudomonas aeruginosa PAO1 is clearly sensitive for the antibacterial action of the five endolysins in the presence of the outer membrane permeabilizer EDTA: reductions are ranging from 1.89 to 3.08 log units dependent on the endolysin. The predicted transglycosylases BcepC6gp22, P2gp10 and PsP3gp10 have a substantially higher muralytic and in vitro antibacterial activity compared to the predicted amidases K11gp3.5 and KP32gp15, highlighting the impact of the catalytic specificity on endolysin activity. Furthermore, initial data exclude the synergistic lethal effect of a combination of the predicted transglycosylase PsP3gp10 and the predicted amidase K11gp3.5 on PAO1. As these globular endolysins show a lower enzymatic and antibacterial activity, in comparison to modular endolysins, we suggest that the latter should be favored for antibacterial applications.

  12. Vestibular activation of sympathetic nerve activity

    NASA Technical Reports Server (NTRS)

    Ray, C. A.; Carter, J. R.

    2003-01-01

    AIM: The vestibulosympathetic reflex refers to sympathetic nerve activation by the vestibular system. Animal studies indicate that the vestibular system assists in blood pressure regulation during orthostasis. Although human studies clearly demonstrate activation of muscle sympathetic nerve activity (MSNA) during engagement of the otolith organs, the role of the vestibulosympathetic reflex in maintaining blood pressure during orthostasis is not well-established. Examination of the vestibulosympathetic reflex with other cardiovascular reflexes indicates that it is a powerful and independent reflex. Ageing, which is associated with an increased risk for orthostatic hypotension, attenuates the vestibulosympathetic reflex. The attenuated reflex is associated with a reduction in arterial pressure. CONCLUSION: These findings suggest that the vestibulosympathetic reflex assists in blood pressure regulation in humans, but future studies examining this reflex in other orthostatically intolerant populations are necessary to address this hypothesis.

  13. Metabolism Supports Macrophage Activation

    PubMed Central

    Langston, P. Kent; Shibata, Munehiko; Horng, Tiffany

    2017-01-01

    Macrophages are found in most tissues of the body, where they have tissue- and context-dependent roles in maintaining homeostasis as well as coordinating adaptive responses to various stresses. Their capacity for specialized functions is controlled by polarizing signals, which activate macrophages by upregulating transcriptional programs that encode distinct effector functions. An important conceptual advance in the field of macrophage biology, emerging from recent studies, is that macrophage activation is critically supported by metabolic shifts. Metabolic shifts fuel multiple aspects of macrophage activation, and preventing these shifts impairs appropriate activation. These findings raise the exciting possibility that macrophage functions in various contexts could be regulated by manipulating their metabolism. Here, we review the rapidly evolving field of macrophage metabolism, discussing how polarizing signals trigger metabolic shifts and how these shifts enable appropriate activation and sustain effector activities. We also discuss recent studies indicating that the mitochondria are central hubs in inflammatory macrophage activation. PMID:28197151

  14. Activated carbon from biomass

    NASA Astrophysics Data System (ADS)

    Manocha, S.; Manocha, L. M.; Joshi, Parth; Patel, Bhavesh; Dangi, Gaurav; Verma, Narendra

    2013-06-01

    Activated carbon are unique and versatile adsorbents having extended surface area, micro porous structure, universal adsorption effect, high adsorption capacity and high degree of surface reactivity. Activated carbons are synthesized from variety of materials. Most commonly used on a commercial scale are cellulosic based precursors such as peat, coal, lignite wood and coconut shell. Variation occurs in precursors in terms of structure and carbon content. Coir having very low bulk density and porous structure is found to be one of the valuable raw materials for the production of highly porous activated carbon and other important factor is its high carbon content. Exploration of good low cost and non conventional adsorbent may contribute to the sustainability of the environment and offer promising benefits for the commercial purpose in future. Carbonization of biomass was carried out in a horizontal muffle furnace. Both carbonization and activation were performed in inert nitrogen atmosphere in one step to enhance the surface area and to develop interconnecting porosity. The types of biomass as well as the activation conditions determine the properties and the yield of activated carbon. Activated carbon produced from biomass is cost effective as it is easily available as a waste biomass. Activated carbon produced by combination of chemical and physical activation has higher surface area of 2442 m2/gm compared to that produced by physical activation (1365 m2/gm).

  15. Factor XII Contact Activation.

    PubMed

    Naudin, Clément; Burillo, Elena; Blankenberg, Stefan; Butler, Lynn; Renné, Thomas

    2017-03-27

    Contact activation is the surface-induced conversion of factor XII (FXII) zymogen to the serine protease FXIIa. Blood-circulating FXII binds to negatively charged surfaces and this contact to surfaces triggers a conformational change in the zymogen inducing autoactivation. Several surfaces that have the capacity for initiating FXII contact activation have been identified, including misfolded protein aggregates, collagen, nucleic acids, and platelet and microbial polyphosphate. Activated FXII initiates the proinflammatory kallikrein-kinin system and the intrinsic coagulation pathway, leading to formation of bradykinin and thrombin, respectively. FXII contact activation is well characterized in vitro and provides the mechanistic basis for the diagnostic clotting assay, activated partial thromboplastin time. However, only in the past decade has the critical role of FXII contact activation in pathological thrombosis been appreciated. While defective FXII contact activation provides thromboprotection, excess activation underlies the swelling disorder hereditary angioedema type III. This review provides an overview of the molecular basis of FXII contact activation and FXII contact activation-associated disease states.

  16. Marine Biology Activities. Ocean Related Curriculum Activities.

    ERIC Educational Resources Information Center

    Pauls, John

    The ocean affects all of our lives. Therefore, awareness of and information about the interconnections between humans and oceans are prerequisites to making sound decisions for the future. Project ORCA (Ocean Related Curriculum Activities) has developed interdisciplinary curriculum materials designed to meet the needs of students and teachers…

  17. Patterns in Active Nematics

    NASA Astrophysics Data System (ADS)

    Yeomans, Julia M.

    Active systems, from bacterial suspensions to cellular monolayers, are continuously driven out of equilibrium by local injection of energy from their constituent elements and exhibit turbulent-like, chaotic patterns. We describe how active systems can be stabilised by tuning a physical feature of the system, friction. We demonstrate how the crossover between wet active systems, whose behaviour is dominated by hydrodynamics, and dry active matter where any flow is screened, can be achieved by using friction as a control parameter and demonstrate vortex ordering at the wet-dry crossover. We show that the self organisation of vortices into lattices is accompanied by the spatial ordering of topological defects leading to active crystal-like structures. The emergence of vortex lattices which leads to the positional ordering of topological defects may be a useful step towards the design and control of active materials.

  18. Activated recombinant adenovirus proteinases

    DOEpatents

    Anderson, C.W.; Mangel, W.F.

    1999-08-10

    This application describes methods and expression constructs for producing activatable recombinant adenovirus proteinases. Purified activatable recombinant adenovirus proteinases and methods of purification are described. Activated adenovirus proteinases and methods for obtaining activated adenovirus proteinases are further included. Isolated peptide cofactors of adenovirus proteinase activity, methods of purifying and identifying peptide cofactors are also described. Antibodies immunoreactive with adenovirus proteinases, immunospecific antibodies, and methods for preparing them are also described. Other related methods and materials are also described. 29 figs.

  19. Activated recombinant adenovirus proteinases

    DOEpatents

    Anderson, Carl W.; Mangel, Walter F.

    1999-08-10

    This application describes methods and expression constructs for producing activatable recombinant adenovirus proteinases. Purified activatable recombinant adenovirus proteinases and methods of purification are described. Activated adenovirus proteinases and methods for obtaining activated adenovirus proteinases are further included. Isolated peptide cofactors of adenovirus proteinase activity, methods of purifying and identifying said peptide cofactors are also described. Antibodies immunoreactive with adenovirus proteinases, immunospecific antibodies, and methods for preparing them are also described. Other related methods and materials are also described.

  20. Activity in distant comets

    NASA Technical Reports Server (NTRS)

    Luu, Jane X.

    1992-01-01

    Activity in distant comets remains a mystery in the sense that we still have no complete theory to explain the various types of activity exhibited by different comets at large distances. This paper explores the factors that should play a role in determining activity in a distant comet, especially in the cases of comet P/Tempel 2, comet Schwassmann-Wachmann 1, and 2060 Chiron.

  1. Thermally Activated Driver

    NASA Technical Reports Server (NTRS)

    Kinard, William H.; Murray, Robert C.; Walsh, Robert F.

    1987-01-01

    Space-qualified, precise, large-force, thermally activated driver (TAD) developed for use in space on astro-physics experiment to measure abundance of rare actinide-group elements in cosmic rays. Actinide cosmic rays detected using thermally activated driver as heart of event-thermometer (ET) system. Thermal expansion and contraction of silicone oil activates driver. Potential applications in fluid-control systems where precise valve controls are needed.

  2. [Biomedical activity of biosurfactants].

    PubMed

    Krasowska, Anna

    2010-07-23

    Biosurfactants, amphiphilic compounds, synthesized by microorganisms have surface, antimicrobial and antitumor properties. Biosurfactants prevent adhesion and biofilms formation by bacteria and fungi on various surfaces. For many years microbial surfactants are used as antibiotics with board spectrum of activity against microorganisms. Biosurfactants act as antiviral compounds and their antitumor activities are mediated through induction of apoptosis. This work presents the current state of knowledge related to biomedical activity of biosurfactants.

  3. NASA metrication activities

    NASA Technical Reports Server (NTRS)

    Vlannes, P. N.

    1978-01-01

    NASA's organization and policy for metrification, history from 1964, NASA participation in Federal agency activities, interaction with nongovernmental metrication organizations, and the proposed metrication assessment study are reviewed.

  4. Active Flow Control Activities at NASA Langley

    NASA Technical Reports Server (NTRS)

    Anders, Scott G.; Sellers, William L., III; Washburn, Anthony E.

    2004-01-01

    NASA Langley continues to aggressively investigate the potential advantages of active flow control over more traditional aerodynamic techniques. This paper provides an update to a previous paper and describes both the progress in the various research areas and the significant changes in the NASA research programs. The goals of the topics presented are focused on advancing the state of knowledge and understanding of controllable fundamental mechanisms in fluids as well as to address engineering challenges. An organizational view of current research activities at NASA Langley in active flow control as supported by several projects is presented. On-center research as well as NASA Langley funded contracts and grants are discussed at a relatively high level. The products of this research are to be demonstrated either in bench-top experiments, wind-tunnel investigations, or in flight as part of the fundamental NASA R&D program and then transferred to more applied research programs within NASA, DOD, and U.S. industry.

  5. Active Students in Webinars

    ERIC Educational Resources Information Center

    Kolås, Line; Nordseth, Hugo; Yri, Jørgen Sørlie

    2015-01-01

    To ensure student activity in webinars we have defined 10 learning tasks focusing on production and communication e.g. collaborative writing, discussion and polling, and investigated how the technology supports the learning activities. The three project partners in the VisPed-project use different video-conferencing systems, and we analyzed how it…

  6. [Field Learning Activities].

    ERIC Educational Resources Information Center

    Nolde Forest Environmental Education Center, Reading, PA.

    Seventy field activities, pertinent to outdoor, environmental studies, are described in this compilation. Designed for elementary and junior high school students, the activities cover many discipline areas--science, social studies, language arts, health, history, mathematics, and art--and many are multidisciplinary in use. Topics range from soil…

  7. Warm-Up Activities.

    ERIC Educational Resources Information Center

    Mingguang, Yang

    1999-01-01

    Discusses how warm-up activities can help to make the English-as-a-foreign-language classroom a lively and interesting place. Warm-up activities are games carried out at the beginning of each class to motivate students to make good use of class time. (Author/VWL)

  8. Nutrition Activities Resource Guide.

    ERIC Educational Resources Information Center

    New York City Board of Education, Brooklyn, NY. Div. of Special Education.

    The resource guide suggests activities to help special education students make appropriate choices about their nutritional habits. It is explained that the activities can be infused into other curriculum areas. The guide consists of five themes and includes performance objectives for each: foods eaten at school (planning a school lunch, keeping a…

  9. Science World Activities Book.

    ERIC Educational Resources Information Center

    Wisconsin Academy of Sciences, Arts and Letters, Madison.

    This document consists of three sections. Section I contains 19 activities developed by master teachers for the Science World '84 summer science program. These activities focus on studies involving airplane controls, trash bag kites, computers, meteorology, compass orienteering, soils, aquatic ecosystems, bogs, and others. Objectives, materials…

  10. The Journal Synthesizing Activity.

    ERIC Educational Resources Information Center

    Garber, Zev

    The journal synthesizing activity is intended to combine aspects of the formal essay with that of a diary. Activities associated with lecture topics are written up as short journal entries of approximately five typewritten pages and are turned in during the weekly class session at which the related topic is being discussed. The journal project…

  11. Activation of fly ash

    DOEpatents

    Corbin, D.R.; Velenyi, L.J.; Pepera, M.A.; Dolhyj, S.R.

    1986-08-19

    Fly ash is activated by heating a screened magnetic fraction of the ash in a steam atmosphere and then reducing, oxidizing and again reducing the hydrothermally treated fraction. The activated fly ash can be used as a carbon monoxide disproportionating catalyst useful in the production of hydrogen and methane.

  12. Activating Event Knowledge

    ERIC Educational Resources Information Center

    Hare, Mary; Jones, Michael; Thomson, Caroline; Kelly, Sarah; McRae, Ken

    2009-01-01

    An increasing number of results in sentence and discourse processing demonstrate that comprehension relies on rich pragmatic knowledge about real-world events, and that incoming words incrementally activate such knowledge. If so, then even outside of any larger context, nouns should activate knowledge of the generalized events that they denote or…

  13. Coordinating Shared Activities

    NASA Technical Reports Server (NTRS)

    Clement, Bradley

    2004-01-01

    Shared Activity Coordination (ShAC) is a computer program for planning and scheduling the activities of an autonomous team of interacting spacecraft and exploratory robots. ShAC could also be adapted to such terrestrial uses as helping multiple factory managers work toward competing goals while sharing such common resources as floor space, raw materials, and transports. ShAC iteratively invokes the Continuous Activity Scheduling Planning Execution and Replanning (CASPER) program to replan and propagate changes to other planning programs in an effort to resolve conflicts. A domain-expert specifies which activities and parameters thereof are shared and reports the expected conditions and effects of these activities on the environment. By specifying these conditions and effects differently for each planning program, the domain-expert subprogram defines roles that each spacecraft plays in a coordinated activity. The domain-expert subprogram also specifies which planning program has scheduling control over each shared activity. ShAC enables sharing of information, consensus over the scheduling of collaborative activities, and distributed conflict resolution. As the other planning programs incorporate new goals and alter their schedules in the changing environment, ShAC continually coordinates to respond to unexpected events.

  14. Activities: More Calculator Capers.

    ERIC Educational Resources Information Center

    Schmalz, Rosemary

    1983-01-01

    Provided is an activity designed to give grades 7-12 students opportunities to discover numerical patterns and to derive general conclusions from observing data. The activity focuses attention on patterns in products such as 33x34, 333x334, and 3333x3334. Three worksheets and answers are included. (JN)

  15. Choreography of AMPK activation.

    PubMed

    Langendorf, Christopher G; Kemp, Bruce E

    2015-01-01

    A recent study published in Cell Research by Li and colleagues reports a detailed biophysical and structural study of AMPK's intra-molecular interactions during activation. By employing subunit tagging and proximity analysis with the aid of AlphaScreen instrumentation, Li et al. add to our understanding of the choreography of activation of AMPK by both nucleotides and phosphorylation.

  16. Rainy Day Activities.

    ERIC Educational Resources Information Center

    Texas Child Care, 1997

    1997-01-01

    Experienced caregivers plan ahead for rainy days. This article describes specific rainy day activities for young children, such as books and crafts to learn about rain (rain in a jar, making a rainbow), simple cooking activities (taffy pull, cinnamon candy tea), and games (mummy wrap, hunt the thimble, rain lotto). (EV)

  17. Laboratory Activities in Israel

    ERIC Educational Resources Information Center

    Mamlok-Naaman, Rachel; Barnea, Nitza

    2012-01-01

    Laboratory activities have long had a distinctive and central role in the science curriculum, and science educators have suggested that many benefits accrue from engaging students in science laboratory activities. Many research studies have been conducted to investigate the educational effectiveness of laboratory work in science education in…

  18. Peak Longevity Physical Activity

    Cancer.gov

    People who engage in three to five times the recommended minimum level of leisure-time physical activity derive the greatest benefit in terms of mortality reduction when compared with people who do not engage in leisure-time physical activity.

  19. Curriculum Activities on Aging.

    ERIC Educational Resources Information Center

    Schmall, Vicki L.; Benge, Nancy

    This paper contains learning activities on aging for use with elementary, high school, and university students in health, family relationships, social studies, and art courses. The activities are intended to help youth develop a more realistic understanding of the aging process and to become aware of both the problems and benefits associated with…

  20. Students Active in Leadership.

    ERIC Educational Resources Information Center

    Brutcher, Robert

    2001-01-01

    Describes SAIL (Students Active in Leadership) as a school-based, youth-directed group. States that the program helps teenagers learn leadership skills by developing and implementing community service activities. SAIL finds partners with whom to collaborate among local businesses, government, and health associations, and these partners provide the…

  1. Ten Minute Writing Activities.

    ERIC Educational Resources Information Center

    Markus, Sharyn

    Designed with junior high school students in mind, the activities in this booklet are offered as ways to stimulate interest in writing using as little as ten minutes of class time. The activities are arranged in six sections: (1) developing observation skills and paying attention to details; (2) word play, descriptive words, and word collections…

  2. Nature's engines: active matter

    NASA Astrophysics Data System (ADS)

    Yeomans, Julia M.

    2017-03-01

    Active materials, bacteria, molecular motors, and self-propelled colloids, continuously transform chemical energy from the environment to mechanical work. Dense active matter, from layers of cells to flocks of birds, self-assembles into intricate patterns. Nature's engines are complex and efficient, and we would like to exploit her ideas to fabricate nano-machines.

  3. Activation of fly ash

    DOEpatents

    Corbin, David R.; Velenyi, Louis J.; Pepera, Marc A.; Dolhyj, Serge R.

    1986-01-01

    Fly ash is activated by heating a screened magnetic fraction of the ash in a steam atmosphere and then reducing, oxidizing and again reducing the hydrothermally treated fraction. The activated fly ash can be used as a carbon monoxide disproportionating catalyst useful in the production of hydrogen and methane.

  4. Activity Book: Ocean Ecology.

    ERIC Educational Resources Information Center

    Learning, 1992

    1992-01-01

    Presents a collection of activities to help elementary students study ocean ecology. The activities have students investigate ocean inhabitants, analyze animal adaptations, examine how temperature and saltiness affect ocean creatures, and learn about safeguarding the sea. Student pages offer reproducible learning sheets. (SM)

  5. [Biosignals of dermal activity].

    PubMed

    Rathkolb, O; Gallei, L

    1993-01-01

    Electrodermal activity (EDA) summarizes different electrophysiological dimensions of human skin. EDA is based on the activity of sweat glands and their innervation by the autonomic nervous system. EDA is used as indicator in the additional diagnostic assessment of patients in the fields of neurology and psychosomatic medicine.

  6. Active galactic nuclei

    PubMed Central

    Fabian, Andrew C.

    1999-01-01

    Active galactic nuclei are the most powerful, long-lived objects in the Universe. Recent data confirm the theoretical idea that the power source is accretion into a massive black hole. The common occurrence of obscuration and outflows probably means that the contribution of active galactic nuclei to the power density of the Universe has been generally underestimated. PMID:10220363

  7. Reflections on Activity Theory

    ERIC Educational Resources Information Center

    Bakhurst, David

    2009-01-01

    It is sometimes suggested that activity theory represents the most important legacy of Soviet philosophy and psychology. But what exactly "is" activity theory? The canonical account in the West is given by Engestrom, who identifies three stages in the theory's development: from Vygotsky's insights, through Leontiev's articulation of the…

  8. Student Activities. Managing Liability.

    ERIC Educational Resources Information Center

    Bennett, Barbara; And Others

    This monograph suggests ways that college or university administrations can undertake a systematic and careful review of the risks posed by students' activities. Its purpose is to provide guidance in integrating the risk management process into a school's existing approaches to managing student organizations and activities. It is noted that no…

  9. The Activity of Trypsin

    ERIC Educational Resources Information Center

    Russo, Salvatore F.; Holzman, Tom

    1977-01-01

    Describes an experiment that illustrates the following points concerning the experimental determination of trypsin activity: (1) there is a difference in basing enzyme concentration on weight, absorbance, or active sites; and (2) the method of expressing enzyme concentration determines the value of specific, molecular, and catalytic center…

  10. Metastasis and AKT activation.

    PubMed

    Qiao, Meng; Sheng, Shijie; Pardee, Arthur B

    2008-10-01

    Metastasis is responsible for 90% of cancer patient deaths. More information is needed about the molecular basis for its potential detection and treatment. The activated AKT kinase is necessary for many events of the metastatic pathway including escape of cells from the tumor's environment, into and then out of the circulation, activation of proliferation, blockage of apoptosis, and activation of angiogenesis. A series of steps leading to metastatic properties can be initiated upon activation of AKT by phosphorylation on Ser-473. These findings lead to the question of how this activation is connected to metastasis. Activated AKT phosphorylates GSK-3beta causing its proteolytic removal. This increases stability of the negative transcription factor SNAIL, thereby decreasing transcription of the transmembrane protein E-cadherin that forms adhesions between adjacent cells, thereby permitting their detachment. How is AKT hyperactivated in metastatic cells? Increased PI3K or TORC2 kinase activity- or decreased PHLPP phosphatase could be responsible. Furthermore, a positive feedback mechanism is that the decrease of E-cadherin lowers PTEN and thereby increases PIP3, further activating AKT and metastasis.

  11. Aging and Semantic Activation.

    ERIC Educational Resources Information Center

    Howard, Darlene V.

    Three studies tested the theory that long term memory consists of a semantically organized network of concept nodes interconnected by leveled associations or relations, and that when a stimulus is processed, the corresponding concept node is assumed to be temporarily activated and this activation spreads to nearby semantically related nodes. In…

  12. Activities of the ILO.

    ERIC Educational Resources Information Center

    Labour Education, 1984

    1984-01-01

    Seven articles on International Labour Organization (ILO) activities cover study groups at ILO headquarters, a Philippine rural workers seminar, women's participation in Central American union activities, worksite courses in India, and seminars and symposia in Cape Verde, Mauritius, and Sierra Leone. (SK)

  13. Learning Activities for Toddlers.

    ERIC Educational Resources Information Center

    Texas Child Care, 1996

    1996-01-01

    Suggests activities to help toddlers develop skills in the four important areas of self-help, creativity, world mastery, and coordination. Activities include hand washing, button practice, painting, movement and music, bubble making, creation of a nature mural, and a shoe print trail. (TJQ)

  14. Active and Healthy Schools

    ERIC Educational Resources Information Center

    Ball, Stephen; Kovarik, Jessica; Leidy, Heather

    2015-01-01

    The Active and Healthy School Program (AHS) can be used to alter the culture and environment of a school to help children make healthier choices. The purpose of this study was to determine the effectiveness of AHS to increase physical activity while decreasing total screen time, increase healthy food choices, and improve knowledge about physical…

  15. ZOOMsci Activity Guide.

    ERIC Educational Resources Information Center

    Wade, Meredith

    This activity guide is based on the Public Broadcasting System's (PBS) program "ZOOM." It is designed for educators with activities that are categorized into three themes: (1) Things That Go, which includes "Air" which explores air pressure, "Rubber Bands" which discovers the potential energy of rubber bands,…

  16. Emotionally Intense Science Activities

    ERIC Educational Resources Information Center

    King, Donna; Ritchie, Stephen; Sandhu, Maryam; Henderson, Senka

    2015-01-01

    Science activities that evoke positive emotional responses make a difference to students' emotional experience of science. In this study, we explored 8th Grade students' discrete emotions expressed during science activities in a unit on Energy. Multiple data sources including classroom videos, interviews and emotion diaries completed at the end of…

  17. Active optical zoom system

    DOEpatents

    Wick, David V.

    2005-12-20

    An active optical zoom system changes the magnification (or effective focal length) of an optical imaging system by utilizing two or more active optics in a conventional optical system. The system can create relatively large changes in system magnification with very small changes in the focal lengths of individual active elements by leveraging the optical power of the conventional optical elements (e.g., passive lenses and mirrors) surrounding the active optics. The active optics serve primarily as variable focal-length lenses or mirrors, although adding other aberrations enables increased utility. The active optics can either be LC SLMs, used in a transmissive optical zoom system, or DMs, used in a reflective optical zoom system. By appropriately designing the optical system, the variable focal-length lenses or mirrors can provide the flexibility necessary to change the overall system focal length (i.e., effective focal length), and therefore magnification, that is normally accomplished with mechanical motion in conventional zoom lenses. The active optics can provide additional flexibility by allowing magnification to occur anywhere within the FOV of the system, not just on-axis as in a conventional system.

  18. Emotionally Intense Science Activities

    NASA Astrophysics Data System (ADS)

    King, Donna; Ritchie, Stephen; Sandhu, Maryam; Henderson, Senka

    2015-08-01

    Science activities that evoke positive emotional responses make a difference to students' emotional experience of science. In this study, we explored 8th Grade students' discrete emotions expressed during science activities in a unit on Energy. Multiple data sources including classroom videos, interviews and emotion diaries completed at the end of each lesson were analysed to identify individual student's emotions. Results from two representative students are presented as case studies. Using a theoretical perspective drawn from theories of emotions founded in sociology, two assertions emerged. First, during the demonstration activity, students experienced the emotions of wonder and surprise; second, during a laboratory activity, students experienced the intense positive emotions of happiness/joy. Characteristics of these activities that contributed to students' positive experiences are highlighted. The study found that choosing activities that evoked strong positive emotional experiences, focused students' attention on the phenomenon they were learning, and the activities were recalled positively. Furthermore, such positive experiences may contribute to students' interest and engagement in science and longer term memorability. Finally, implications for science teachers and pre-service teacher education are suggested.

  19. List 9 - Active CERCLIS Sites:

    EPA Pesticide Factsheets

    The List 9 displays the sequence of activities undertaken at active CERCLIS sites. An active site is one at which site assessment, removal, remedial, enforcement, cost recovery, or oversight activities are being planned or conducted.

  20. THE ACTIVE CENTAURS

    SciTech Connect

    Jewitt, David

    2009-05-15

    The Centaurs are recent escapees from the Kuiper Belt that are destined either to meet fiery oblivion in the hot inner regions of the solar system or to be ejected to the interstellar medium by gravitational scattering from the giant planets. Dynamically evolved Centaurs, when captured by Jupiter and close enough to the Sun for near-surface water ice to sublimate, are conventionally labeled as 'short-period' (specifically, Jupiter-family) comets. Remarkably, some Centaurs show comet-like activity even when far beyond the orbit of Jupiter, suggesting mass loss driven by a process other than the sublimation of water ice. We observed a sample of 23 Centaurs and found nine to be active, with mass-loss rates measured from several kg s{sup -1} to several tonnes s{sup -1}. Considered as a group, we find that the 'active Centaurs' in our sample have perihelia smaller than the inactive Centaurs (median 5.9 AU versus 8.7 AU), and smaller than the median perihelion distance computed for all known Centaurs (12.4 AU). This suggests that their activity is thermally driven. We consider several possibilities for the origin of the mass loss from the active Centaurs. Most are too cold for activity at the observed levels to originate via the sublimation of crystalline water ice. Solid carbon monoxide and carbon dioxide have the opposite problem: they are so volatile that they should drive activity in Centaurs at much larger distances than observed. We consider the possibility that activity in the Centaurs is triggered by the conversion of amorphous ice into the crystalline form accompanied by the release of trapped gases, including carbon monoxide. By imposing the condition that crystallization should occur when the crystallization time is shorter than the orbital period we find a qualitative match to the perihelion distribution of the active Centaurs and conclude that the data are consistent with the hypothesis that the Centaurs contain amorphous ice.

  1. Physics of solar activity

    NASA Technical Reports Server (NTRS)

    Sturrock, Peter A.

    1993-01-01

    The aim of the research activity was to increase our understanding of solar activity through data analysis, theoretical analysis, and computer modeling. Because the research subjects were diverse and many researchers were supported by this grant, a select few key areas of research are described in detail. Areas of research include: (1) energy storage and force-free magnetic field; (2) energy release and particle acceleration; (3) radiation by nonthermal electrons; (4) coronal loops; (5) flare classification; (6) longitude distributions of flares; (7) periodicities detected in the solar activity; (8) coronal heating and related problems; and (9) plasma processes.

  2. Algorithm-development activities

    NASA Technical Reports Server (NTRS)

    Carder, Kendall L.

    1994-01-01

    The task of algorithm-development activities at USF continues. The algorithm for determining chlorophyll alpha concentration, (Chl alpha) and gelbstoff absorption coefficient for SeaWiFS and MODIS-N radiance data is our current priority.

  3. MARIHUANA ACTIVITY OF CANNABINOL.

    PubMed

    Loewe, S

    1945-12-14

    Cannabinol, generally believed to be an inert component of hemp oil, is shown to have marihuana activity. The significance of this observation with regard to the relationship between structure and mamactivity in the class of cannabinols is discussed.

  4. Balance Food and Activity

    MedlinePlus

    ... eNewsletters Calendar Balance Food and Activity What is Energy Balance? Energy is another word for "calories." Your ... adults, fewer calories are needed at older ages. Energy Balance in Real Life Think of it as ...

  5. Activities in Teaching Weather

    ERIC Educational Resources Information Center

    Tonn, Martin

    1977-01-01

    Presented is a unit composed of activities for teaching weather. Topics include cloud types and formation, simple weather instruments, and the weather station. Illustrations include a weather chart and instruments. A bibliography is given. (MA)

  6. Extravehicular activity technology discipline

    NASA Technical Reports Server (NTRS)

    Webbon, Bruce W.

    1990-01-01

    Viewgraphs on extravehicular activity technology discipline for Space Station Freedom are presented. Topics covered include: extravehicular mobility unit; airlock and EMU support equipment; tools, mobility aids, and workstations; and telerobotic work aids interfaces.

  7. French space activities

    NASA Technical Reports Server (NTRS)

    Blanc, R.

    1982-01-01

    The four main points of research and development of space programs by France are explained. The National Center of Space Studies is discussed, listing the missions of the Center and describing the activities of the staff.

  8. Active Fire Mapping Program

    MedlinePlus

    Active Fire Mapping Program Current Large Incidents (Home) New Large Incidents Fire Detection Maps MODIS Satellite Imagery VIIRS Satellite Imagery Fire Detection GIS Data Fire Data in Google Earth ...

  9. ERLN Activities Details

    EPA Pesticide Factsheets

    Environmental Response Laboratory Network activities include the All Hazard Receipt Facility and Screening Protocol, standardizing chemical methods, Chemical Warfare Agent Fixed Laboratory Pilot Project, microbial efforts, and WLA response plan.

  10. The Activity Centre.

    ERIC Educational Resources Information Center

    Australian Mathematics Teacher, 1989

    1989-01-01

    Presents four examples on arithmetic mean and harmonic mean. Provides solution of each of the examples and instructional activities related to the examples. Lists eight references on mathematical problem solving. (YP)

  11. Active at Any Size

    MedlinePlus

    ... a row. Your muscles need time to recover. Mind and body exercise Your local hospital or fitness, ... can be viewed at www.ClinicalTrials.gov . Additional Reading Tips to Help You Get Active Identifies and ...

  12. Exercise and activity - children

    MedlinePlus

    ... and most other organized sports (such as soccer, swimming, and dancing) Younger children cannot stick with the ... your child's preferences and abilities. Individual activities include swimming, running, skiing, or biking. Group sports are another ...

  13. Active terahertz metamaterials

    SciTech Connect

    Chen, Hou-tong

    2009-01-01

    We demonstrate planar terahertz metamaterial devices enabling actively controllable transmission amplitude, phase, or frequency at room temperature via carrier depletion or photoexcitation in the semiconductor substrate or in semiconductor materials incorporated into the metamaterial structure.

  14. Enrichment Activities for Geometry.

    ERIC Educational Resources Information Center

    Usiskin, Zalman

    1983-01-01

    Enrichment activities that teach about geometry as they instruct in geometry are given for some significant topics. The facets of geometry included are tessellations, round robin tournaments, geometric theorems on triangles, and connections between geometry and complex numbers. (MNS)

  15. Interactive Design Activism

    NASA Astrophysics Data System (ADS)

    Goulev, Petar; Farrer, Joan

    The following sections are included: * Introduction * Computers and Human Well-being * To Fuzzy or Yes (No)! * Interactive Design Activism * Sensing the Sun * Personalised Public Health Advice * Modifying Human Behaviour * Transdisciplinarity, Knowledge Transfer and Multi-domain

  16. Island Watershed Activity.

    ERIC Educational Resources Information Center

    Benson, Rod

    2003-01-01

    Describes a 90-minute "Island Watershed" activity to help earth science students understand the concept of the water cycle. Introduces a surface waters unit appropriate for students in grades 7-10. Includes watershed project guidelines. (Author/KHR)

  17. Active Limiters For Photodetectors

    NASA Technical Reports Server (NTRS)

    Katz, Joseph; Cheng, Li-Jen

    1990-01-01

    Active or "smart" electro-optical shutters proposed for protection of photodetectors, imaging devices, and other sensitive optical or optoelectronic elements. Responds rapidly and automatically to increase in illumination above prescribed level.

  18. Math Lab Activities

    ERIC Educational Resources Information Center

    Brumbaugh, Douglas K.; Hynes, Michael C.

    1974-01-01

    The goals, objects, materials and grade levels are specified in this description of a laboratory activity involving analytic geometry concepts. Students mark out bicycle gymkhana courses in which directions to participants are given by Cartesian coordinates. (JP)

  19. Low activation ferritic alloys

    DOEpatents

    Gelles, David S.; Ghoniem, Nasr M.; Powell, Roger W.

    1986-01-01

    Low activation ferritic alloys, specifically bainitic and martensitic stainless steels, are described for use in the production of structural components for nuclear fusion reactors. They are designed specifically to achieve low activation characteristics suitable for efficient waste disposal. The alloys essentially exclude molybdenum, nickel, nitrogen and niobium. Strength is achieved by substituting vanadium, tungsten, and/or tantalum in place of the usual molybdenum content in such alloys.

  20. Low activation ferritic alloys

    DOEpatents

    Gelles, D.S.; Ghoniem, N.M.; Powell, R.W.

    1985-02-07

    Low activation ferritic alloys, specifically bainitic and martensitic stainless steels, are described for use in the production of structural components for nuclear fusion reactors. They are designed specifically to achieve low activation characteristics suitable for efficient waste disposal. The alloys essentially exclude molybdenum, nickel, nitrogen and niobium. Strength is achieved by substituting vanadium, tungsten, and/or tantalum in place of the usual molybdenum content in such alloys.

  1. RAVEN Quality Assurance Activities

    SciTech Connect

    Cogliati, Joshua Joseph

    2015-09-01

    This report discusses the quality assurance activities needed to raise the Quality Level of Risk Analysis in a Virtual Environment (RAVEN) from Quality Level 3 to Quality Level 2. This report also describes the general RAVEN quality assurance activities. For improving the quality, reviews of code changes have been instituted, more parts of testing have been automated, and improved packaging has been created. For upgrading the quality level, requirements have been created and the workflow has been improved.

  2. Activated partial thromboplastin time.

    PubMed

    Ignjatovic, Vera

    2013-01-01

    Activated partial thromboplastin time (APTT) is a commonly used coagulation assay that is easy to perform, is affordable, and is therefore performed in most coagulation laboratories, both clinical and research, worldwide. The APTT is based on the principle that in citrated plasma, the addition of a platelet substitute, factor XII activator, and CaCl2 allows for formation of a stable clot. The time required for the formation of a stable clot is recorded in seconds and represents the actual APTT result.

  3. Active aperture phased arrays

    NASA Astrophysics Data System (ADS)

    Shenoy, R. P.

    1989-04-01

    Developments towards the realization of active aperture phased arrays are reviewed. The technology and cost aspects of the power amplifier and phase shifter subsystems are discussed. Consideration is given to research concerning T/R modules, MESFETs, side lobe control, beam steering, optical control techniques, and printed circuit antennas. Methods for configuring the array are examined, focusing on the tile and brick configurations. It is found that there is no technological impediment for introducing active aperture phased arrays.

  4. Intercreativity: Mapping Online Activism

    NASA Astrophysics Data System (ADS)

    Meikle, Graham

    How do activists use the Internet? This article maps a wide range of activist practice and research by applying and developing Tim Berners-Lee's concept of ‘intercreativity' (1999). It identifies four dimensions of Net activism: intercreative texts, tactics, strategies and networks. It develops these through examples of manifestations of Net activism around one cluster of issues: support campaigns for refugees and asylum seekers.

  5. ABB: active bandwidth broker

    NASA Astrophysics Data System (ADS)

    Wong, Kason; Law, Eddie

    2001-07-01

    In this paper, we shall discuss a novel design on the policy-based management for the Internet. This design deploys the concept of active networking. As opposed to the traditional network design, active network empowers network node with the ability to manipulate data and program code in packets, and configure the network properties according to the needs of different applications. The policy-based management can control network routers in order to realize end-to-end Quality of Service (QoS), such as differentiated and integrated services, across the Internet. For the moment, the Internet Engineering Task Force (IETF) has defined the framework of the policy-based management. It employs a simple client/server model that uses Common Open Policy Service (COPS) protocol to facilitate policy management and control. Our design of Active Bandwidth Broker (ABB) belongs to an active application. Our goals are to distribute centralized workload of the policy-based management over multiple active nodes in the active networks, introduce mobility of the bandwidth brokers, and allows load sharing to the policy-based management. This results a network-wide intelligent, highly available, and consistent QoS control that allows performance protection for voice, video and Internet business application while reducing costs for growing networks.

  6. Rheology of Active Gels

    NASA Astrophysics Data System (ADS)

    Chen, Daniel

    2015-03-01

    Active networks drive a diverse range of critical processes ranging from motility to division in living cells, yet a full picture of their rheological capabilities in non-cellular contexts is still emerging, e.g., How does the rheological response of a network capable of remodeling under internally-generated stresses differ from that of a passive biopolymer network? In order to address this and other basic questions, we have engineered an active gel composed of microtubules, bidirectional kinesin motors, and molecular depletant that self-organizes into a highly dynamic network of active bundles. The network continually remodels itself under ATP-tunable cycles of extension, buckling, fracturing, and self-healing. Using confocal rheometry we have simultaneously characterized the network's linear and non-linear rheological responses to shear deformation along with its dynamic morphology. We find several surprising and unique material properties for these active gels; most notably, rheological cloaking, the ability of the active gel to drive large-scale fluid mixing over several orders of flow magnitude while maintaining an invariant, solid-like rheological profile and spontaneous flow under confinement, the ability to exert micro-Newton forces to drive persistent directed motion of the rheometer tool. Taken together, these results and others to be discussed highlight the rich stress-structure-dynamics relationships in this class of biologically-derived active gels.

  7. Antimicrobial activity of flavonoids.

    PubMed

    Cushnie, T P Tim; Lamb, Andrew J

    2005-11-01

    Flavonoids are ubiquitous in photosynthesising cells and are commonly found in fruit, vegetables, nuts, seeds, stems, flowers, tea, wine, propolis and honey. For centuries, preparations containing these compounds as the principal physiologically active constituents have been used to treat human diseases. Increasingly, this class of natural products is becoming the subject of anti-infective research, and many groups have isolated and identified the structures of flavonoids possessing antifungal, antiviral and antibacterial activity. Moreover, several groups have demonstrated synergy between active flavonoids as well as between flavonoids and existing chemotherapeutics. Reports of activity in the field of antibacterial flavonoid research are widely conflicting, probably owing to inter- and intra-assay variation in susceptibility testing. However, several high-quality investigations have examined the relationship between flavonoid structure and antibacterial activity and these are in close agreement. In addition, numerous research groups have sought to elucidate the antibacterial mechanisms of action of selected flavonoids. The activity of quercetin, for example, has been at least partially attributed to inhibition of DNA gyrase. It has also been proposed that sophoraflavone G and (-)-epigallocatechin gallate inhibit cytoplasmic membrane function, and that licochalcones A and C inhibit energy metabolism. Other flavonoids whose mechanisms of action have been investigated include robinetin, myricetin, apigenin, rutin, galangin, 2,4,2'-trihydroxy-5'-methylchalcone and lonchocarpol A. These compounds represent novel leads, and future studies may allow the development of a pharmacologically acceptable antimicrobial agent or class of agents.

  8. Phytase activity in lichens.

    PubMed

    Higgins, Niall F; Crittenden, Peter D

    2015-10-01

    Phytase activity was investigated in 13 lichen species using a novel assay method. The work tested the hypothesis that phytase is a component of the suite of surface-bound lichen enzymes that hydrolyse simple organic forms of phosphorus (P) and nitrogen (N) deposited onto the thallus surface. Hydrolysis of inositol hexaphosphate (InsP6 , the substrate for phytase) and appearance of lower-order inositol phosphates (InsP5 -InsP1 ), the hydrolysis products, were measured by ion chromatography. Phytase activity in Evernia prunastri was compared among locations with contrasting rates of N deposition. Phytase activity was readily measurable in epiphytic lichens (e.g. 11.3 μmol InsP6 hydrolysed g(-1)  h(-1) in Bryoria fuscescens) but low in two terricolous species tested (Cladonia portentosa and Peltigera membranacea). Phytase and phosphomonoesterase activities were positively correlated amongst species. In E. prunastri both enzyme activities were promoted by N enrichment and phytase activity was readily released into thallus washings. InsP6 was not detected in tree canopy throughfall but was present in pollen leachate. Capacity to hydrolyse InsP6 appears widespread amongst lichens potentially promoting P capture from atmospheric deposits and plant leachates, and P cycling in forest canopies. The enzyme assay used here might find wider application in studies on plant root-fungal-soil systems.

  9. T cell activation.

    PubMed

    Smith-Garvin, Jennifer E; Koretzky, Gary A; Jordan, Martha S

    2009-01-01

    This year marks the 25th anniversary of the first Annual Review of Immunology article to describe features of the T cell antigen receptor (TCR). In celebration of this anniversary, we begin with a brief introduction outlining the chronology of the earliest studies that established the basic paradigm for how the engaged TCR transduces its signals. This review continues with a description of the current state of our understanding of TCR signaling, as well as a summary of recent findings examining other key aspects of T cell activation, including cross talk between the TCR and integrins, the role of costimulatory molecules, and how signals may negatively regulate T cell function.Acronyms and DefinitionsAdapter protein: cellular protein that functions to bridge molecular interactions via characteristic domains able to mediate protein/protein or protein/lipid interactions Costimulation: signals delivered to T cells by cell surface receptors other than the TCR itself that potentiate T cell activation cSMAC: central supramolecular activation cluster Immunoreceptor tyrosine-based activation motif (ITAM): a short peptide sequence in the cytoplasmic tails of key surface receptors on hematopoietic cells that is characterized by tyrosine residues that are phosphorylated by Src family PTKs, enabling the ITAM to recruit activated Syk family kinases Inside-out signaling: signals initiated by engagement of immunoreceptors that lead to conformational changes and clustering of integrins, thereby increasing the affinity and avidity of the integrins for their ligands NFAT: nuclear factor of activated T cells PI3K: phosphoinositide 3-kinase PKC: protein kinase C PLC: phospholipase C pMHC: peptide major histocompatibility complex (MHC) complex pSMAC: peripheral supramolecular activation cluster PTK: protein tyrosine kinase Signal transduction: biochemical events linking surface receptor engagement to cellular responses TCR: T cell antigen receptor

  10. Sirtuin activators and inhibitors

    PubMed Central

    Villalba, José M.; Alcaín, Francisco J.

    2012-01-01

    Sirtuins 1-7 (SIRT1-7) belong to the third class of deacetylase enzymes, which are dependent on NAD+ for activity. Sirtuins activity is linked to gene repression, metabolic control, apoptosis and cell survival, DNA repair, development, inflammation, neuroprotection and healthy aging. Because sirtuins modulation could have beneficial effects on human diseases there is a growing interest in the discovery of small molecules modifying their activity. We review here those compounds known to activate or inhibit sirtuins, discussing the data that support the use of sirtuin-based therapies. Almost all sirtuin activators have been described only for SIRT1. Resveratrol is a natural compound which activates SIRT1, and may help in the treatment or prevention of obesity, and in preventing tumorigenesis and the aging-related decline in heart function and neuronal loss. Due to its poor bioavailability, reformulated versions of resveratrol with improved bioavailability have been developed (resVida, Longevinex®, SRT501). Molecules that are structurally unrelated to resveratrol (SRT1720, SRT2104, SRT2379, among others) have been also developed to stimulate sirtuin activities more potently than resveratrol. Sirtuin inhibitors with a wide range of core structures have been identified for SIRT1, SIRT2, SIRT3 and SIRT5 (splitomicin, sirtinol, AGK2, cambinol, suramin, tenovin, salermide, among others). SIRT1 inhibition has been proposed in the treatment of cancer, immunodeficiency virus infections, Fragile X mental retardation syndrome and for preventing or treating parasitic diseases, whereas SIRT2 inhibitors might be useful for the treatment of cancer and neurodegenerative diseases. PMID:22730114

  11. Antimutagenic activity of spearmint.

    PubMed

    Yu, Tian-Wei; Xu, Meirong; Dashwood, Roderick H

    2004-01-01

    The antimutagenic activity of spearmint (Mentha spicata), a popular food flavoring agent, was studied in the Salmonella assay. Spearmint leaves were brewed in hot water for 5 min at concentrations up to 5% (w/v), and the water extracts were tested against the direct-acting mutagens 4-nitro-1,2-phenylenediamine (NPD) and 2-hydroxyamino-3-methyl-3H-imidazo[4,5-f]quinoline (N-OH-IQ) using Salmonella typhimurium strain TA98. Nontoxic concentrations of spearmint extract inhibited the mutagenic activity of N-OH-IQ in a concentration-dependent fashion, but had no effect against NPD. These experiments by design focused on the water extract consumed commonly as an herbal tea, but chloroform and methanol extracts of spearmint also possessed antimutagenic activity against N-OH-IQ. Water extract of spearmint inhibited the mutagenic activity of the parent compound, 2-amino-3-methyl-3H-imidazo[4,5-f]quinoline (IQ), in the presence of rat liver S9; however, the concentration for 50% inhibition (IC50) against IQ was approximately 10-fold higher than in assays with N-OH-IQ minus S9. At concentrations similar to those used in the Salmonella assays, spearmint extract inhibited two of the major enzymes that play a role in the metabolic activation of IQ, namely, cytochromes P4501A1 and 1A2, based on ethoxyresorufin O-deethylase and methoxyresorufin O-demethylase assays in vitro. In vivo, rats were given spearmint water extract (2%; w/v) as the sole source of drinking fluid before, during, and after 2-week treatment with IQ; colonic aberrant crypt foci were inhibited significantly at 8 weeks (P < 0.05, compared with rats given IQ alone). Collectively, these findings suggest that spearmint tea protects against IQ and possibly other heterocyclic amines through inhibition of carcinogen activation and via direct effects on the activated metabolite(s).

  12. [Inflammasome: activation mechanisms].

    PubMed

    Suárez, Raibel; Buelvas, Neudo

    2015-03-01

    Inflammation is a rapid biologic response of the immune system in vascular tissues, directed to eliminate stimuli capable of causing damage and begin the process of repair. The macromolecular complexes known as "inflammasomes" are formed by a receptor, either NOD (NLR) or ALR, the receptor absent in melanoma 2 (AIM2). In addition, the inflammasome is formed by the speck-like protein associated to apoptosis (ASC) and procaspase-1, that may be activated by variations in the ionic and intracellular and extracellular ATP concentrations; and the loss of stabilization of the fagolisosomme by internalization of insoluble crystals and redox mechanisms. As a result, there is activation of the molecular platform and the processing of inflammatory prointerleukins to their active forms. There are two modalities of activation of the inflammasome: canonical and non-canonical, both capable of generating effector responses. Recent data associate NLRP 3, IL-1β and IL-18 in the pathogenesis of a variety of diseases, including atherosclerosis, type II diabetes, hyperhomocysteinemia, gout, malaria and hypertension. The inflammasome cascade is emerging as a new chemotherapeutic target in these diseases. In this review we shall discuss the mechanisms of activation and regulation of the inflammasome that stimulate, modulate and resolve inflammation.

  13. Chromatin as active matter

    NASA Astrophysics Data System (ADS)

    Agrawal, Ankit; Ganai, Nirmalendu; Sengupta, Surajit; Menon, Gautam I.

    2017-01-01

    Active matter models describe a number of biophysical phenomena at the cell and tissue scale. Such models explore the macroscopic consequences of driving specific soft condensed matter systems of biological relevance out of equilibrium through ‘active’ processes. Here, we describe how active matter models can be used to study the large-scale properties of chromosomes contained within the nuclei of human cells in interphase. We show that polymer models for chromosomes that incorporate inhomogeneous activity reproduce many general, yet little understood, features of large-scale nuclear architecture. These include: (i) the spatial separation of gene-rich, low-density euchromatin, predominantly found towards the centre of the nucleus, vis a vis. gene-poor, denser heterochromatin, typically enriched in proximity to the nuclear periphery, (ii) the differential positioning of individual gene-rich and gene-poor chromosomes, (iii) the formation of chromosome territories, as well as (iv), the weak size-dependence of the positions of individual chromosome centres-of-mass relative to the nuclear centre that is seen in some cell types. Such structuring is induced purely by the combination of activity and confinement and is absent in thermal equilibrium. We systematically explore active matter models for chromosomes, discussing how our model can be generalized to study variations in chromosome positioning across different cell types. The approach and model we outline here represent a preliminary attempt towards a quantitative, first-principles description of the large-scale architecture of the cell nucleus.

  14. Active flows on trees

    NASA Astrophysics Data System (ADS)

    Forrow, Aden; Woodhouse, Francis G.; Dunkel, Jörn

    2016-11-01

    Coherent, large scale dynamics in many nonequilibrium physical, biological, or information transport networks are driven by small-scale local energy input. We introduce and explore a generic model for compressible active flows on tree networks. In contrast to thermally-driven systems, active friction selects discrete states with only a small number of oscillation modes activated at distinct fixed amplitudes. This state selection can interact with graph topology to produce different localized dynamical time scales in separate regions of large networks. Using perturbation theory, we systematically predict the stationary states of noisy networks. Our analytical predictions agree well with a Bayesian state estimation based on a hidden Markov model applied to simulated time series data on binary trees. While the number of stable states per tree scales exponentially with the number of edges, the mean number of activated modes in each state averages 1 / 4 the number of edges. More broadly, these results suggest that the macroscopic response of active networks, from actin-myosin networks in cells to flow networks in Physarum polycephalum, can be dominated by a few select modes.

  15. Interpreting EEG alpha activity.

    PubMed

    Bazanova, O M; Vernon, D

    2014-07-01

    Exploring EEG alpha oscillations has generated considerable interest, in particular with regards to the role they play in cognitive, psychomotor, psycho-emotional and physiological aspects of human life. However, there is no clearly agreed upon definition of what constitutes 'alpha activity' or which of the many indices should be used to characterize it. To address these issues this review attempts to delineate EEG alpha-activity, its physical, molecular and morphological nature, and examine the following indices: (1) the individual alpha peak frequency; (2) activation magnitude, as measured by alpha amplitude suppression across the individual alpha bandwidth in response to eyes opening, and (3) alpha "auto-rhythmicity" indices: which include intra-spindle amplitude variability, spindle length and steepness. Throughout, the article offers a number of suggestions regarding the mechanism(s) of alpha activity related to inter and intra-individual variability. In addition, it provides some insights into the various psychophysiological indices of alpha activity and highlights their role in optimal functioning and behavior.

  16. Active thermal cloak

    NASA Astrophysics Data System (ADS)

    Nguyen, Dang Minh; Xu, Hongyi; Zhang, Youming; Zhang, Baile

    2015-09-01

    Thermal cloaking, as an ultimate thermal "illusion" phenomenon, is the result of advanced heat manipulation with thermal metamaterials—heat can be guided around a hidden object smoothly without disturbing the ambient thermal environment. However, all previous thermal metamaterial cloaks were passive devices, lacking the functionality of switching on/off and the flexibility of changing geometries. In this letter, we report an active thermal cloaking device that is controllable. Different from previous thermal cloaking approaches, this thermal cloak adopts active thermoelectric components to "pump" heat from one side to the other side of the hidden object, in a process controlled by input electric voltages. Our work not only incorporates active components in thermal cloaking but also provides controllable functionality in thermal metamaterials that can be used to construct more flexible thermal devices.

  17. Activity Cycles in Stars

    NASA Technical Reports Server (NTRS)

    Hathaway, David H.

    2009-01-01

    Starspots and stellar activity can be detected in other stars using high precision photometric and spectrometric measurements. These observations have provided some surprises (starspots at the poles - sunspots are rarely seen poleward of 40 degrees) but more importantly they reveal behaviors that constrain our models of solar-stellar magnetic dynamos. The observations reveal variations in cycle characteristics that depend upon the stellar structure, convection zone dynamics, and rotation rate. In general, the more rapidly rotating stars are more active. However, for stars like the Sun, some are found to be inactive while nearly identical stars are found to be very active indicating that periods like the Sun's Maunder Minimum (an inactive period from 1645 to 1715) are characteristic of Sun-like stars.

  18. Antimicrobial activity of spices.

    PubMed

    Arora, D S; Kaur, J

    1999-08-01

    Spices have been shown to possess medicinal value, in particular, antimicrobial activity. This study compares the sensitivity of some human pathogenic bacteria and yeasts to various spice extracts and commonly employed chemotherapeutic substances. Of the different spices tested only garlic and clove were found to possess antimicrobial activity. The bactericidal effect of garlic extract was apparent within 1 h of incubation and 93% killing of Staphylococcus epidermidis and Salmonella typhi was achieved within 3 h. Yeasts were totally killed in 1 h by garlic extract but in 5 h with clove. Some bacteria showing resistance to certain antibiotics were sensitive to extracts of both garlic and clove. Greater anti-candidal activity was shown by garlic than by nystatin. Spices might have a great potential to be used as antimicrobial agents.

  19. PRODUCTS OF ACTIVATED LYMPHOCYTES

    PubMed Central

    Sorg, Clemens; Bloom, Barry R.

    1973-01-01

    General methods were developed and applied to the biosynthesis and purification of products of activated lymphocytes available in minute quantities. The activity studied here was the migration inhibitory factor (MIF) produced by purified protein derivative (PPD)- or concanavalin A (Con A)-stimulated lymphocytes obtained from one guinea pig or less. The methods selected yielded results in terms of two chemical parameters characteristic of the molecules involved, namely Kd on Sephadex G-75 and isoionic point, pI, on isoelectric focusing. When supernatants were fractionated on G-75 columns, there were several areas even in control supernatants which produced migration inhibition relative to medium controls. However, in PPD- and Con A-stimulated supernatants, at least one peak of MIF activity was found solely in the stimulated cultures, with a Kd of 0.15. A double-labeling technique was used to characterize the proteins of this peak. Control, unstimulated cultures were labeled with [14C]leucine and stimulated cultures were labeled with [3H]leucine. After mixing the supernatants and G-75 filtration, a major "ratiolabeled" broad peak. i.e. one with increased 3H/14C ratio, was found. When a narrow portion of this peak about Kd 0.15, containing most of the MIF activity, was subjected to analytical isoelectric focusing, all of the label was associated with proteins of lower net charge than albumin. A unique ratiolabeled peak was found in PPD- and Con A-stimulated fractions with a pI of approx. 5.3. A micropreparative isoelectric focusing technique was developed and yielded MIF activity in the same region as the major ratiolabeled peak. Further study will be required to ascertain whether the ratiolabeled protein is MIF. By following the Kd, pI, and 3H/14C labeling ratio, at least 14 products of activated lymphocytes, synthesized either de novo or in increased amounts, could be distinguished. PMID:4688317

  20. Active cleaning technique device

    NASA Technical Reports Server (NTRS)

    Shannon, R. L.; Gillette, R. B.

    1973-01-01

    The objective of this program was to develop a laboratory demonstration model of an active cleaning technique (ACT) device. The principle of this device is based primarily on the technique for removing contaminants from optical surfaces. This active cleaning technique involves exposing contaminated surfaces to a plasma containing atomic oxygen or combinations of other reactive gases. The ACT device laboratory demonstration model incorporates, in addition to plasma cleaning, the means to operate the device as an ion source for sputtering experiments. The overall ACT device includes a plasma generation tube, an ion accelerator, a gas supply system, a RF power supply and a high voltage dc power supply.

  1. Actively coupled optical waveguides

    NASA Astrophysics Data System (ADS)

    Alexeeva, N. V.; Barashenkov, I. V.; Rayanov, K.; Flach, S.

    2014-01-01

    We consider light propagation through a pair of nonlinear optical waveguides with absorption, placed in a medium with power gain. The active medium boosts the in-phase component of the overlapping evanescent fields of the guides, while the nonlinearity of the guides couples it to the damped out-of-phase component creating a feedback loop. As a result, the structure exhibits stable stationary and oscillatory regimes in a wide range of gain-loss ratios. We show that the pair of actively coupled (AC) waveguides can act as a stationary or integrate-and-fire comparator sensitive to tiny differences in their input powers.

  2. MCO Monitoring activity description

    SciTech Connect

    SEXTON, R.A.

    1998-11-09

    Spent Nuclear Fuel remaining from Hanford's N-Reactor operations in the 1970s has been stored under water in the K-Reactor Basins. This fuel will be repackaged, dried and stored in a new facility in the 200E Area. The safety basis for this process of retrieval, drying, and interim storage of the spent fuel has been established. The monitoring of MCOS in dry storage is a currently identified issue in the SNF Project. This plan outlines the key elements of the proposed monitoring activity. Other fuel stored in the K-Reactor Basins, including SPR fuel, will have other monitoring considerations and is not addressed by this activity description.

  3. Inflammasomes and Their Activation

    PubMed Central

    Khare, Sonal; Luc, Nancy; Dorfleutner, Andrea; Stehlik, Christian

    2011-01-01

    The innate immune system relies on the recognition of pathogens by pattern recognition receptors as a first line of defense and to initiate the adaptive immune response. Substantial progress has been made in defining the role of Nod (nucleotide-binding oligimerization domain)-like receptors and AIM2 (absent in melanoma 2) as pattern recognition receptors that activate inflammasomes in macrophages. Inflammasomes are protein platforms essential for the activation of inflammatory caspases and subsequent maturation of their pro-inflammatory cytokine substrates and induction of pyroptosis. This paper summarizes recent developments regarding the function of Nod-like receptors in immunity and disease. PMID:21083527

  4. Activated carbon material

    DOEpatents

    Evans, A. Gary

    1978-01-01

    Activated carbon particles for use as iodine trapping material are impregnated with a mixture of selected iodine and potassium compounds to improve the iodine retention properties of the carbon. The I/K ratio is maintained at less than about 1 and the pH is maintained at above about 8.0. The iodine retention of activated carbon previously treated with or coimpregnated with triethylenediamine can also be improved by this technique. Suitable flame retardants can be added to raise the ignition temperature of the carbon to acceptable standards.

  5. Antibacterial activity of grepafloxacin.

    PubMed

    Wiedemann, B; Heisig, P

    1997-12-01

    Grepafloxacin has an extremely broad spectrum of activity. Its activity against Gram-positive bacteria exceeds that of currently available quinolones. Grepafloxacin-resistant mutants seem to occur less frequently than ciprofloxacin- or ofloxacin-resistant mutants, and the increase in MIC against the former mutants is less than that of the latter. This applies only to the relative differences (in dilution steps); the absolute values are similar. Grepafloxacin kills Gram-positive bacteria at concentrations little above the MIC. Its pharmacodynamic profile against pneumococci is promising, favouring use of this drug for respiratory tract infections.

  6. Active seismic experiment

    NASA Technical Reports Server (NTRS)

    Kovach, R. L.; Watkins, J. S.; Talwani, P.

    1972-01-01

    The Apollo 16 active seismic experiment (ASE) was designed to generate and monitor seismic waves for the study of the lunar near-surface structure. Several seismic energy sources are used: an astronaut-activated thumper device, a mortar package that contains rocket-launched grenades, and the impulse produced by the lunar module ascent. Analysis of some seismic signals recorded by the ASE has provided data concerning the near-surface structure at the Descartes landing site. Two compressional seismic velocities have so far been recognized in the seismic data. The deployment of the ASE is described, and the significant results obtained are discussed.

  7. Space construction activities

    NASA Technical Reports Server (NTRS)

    1991-01-01

    The Center for Space Construction at the University of Colorado at Boulder was established in 1988 as a University Space Engineering Research Center. The mission of the Center is to conduct interdisciplinary engineering research which is critical to the construction of future space structures and systems and to educate students who will have the vision and technical skills to successfully lead future space construction activities. The research activities are currently organized around two central projects: Orbital Construction and Lunar Construction. Summaries of the research projects are included.

  8. Cosmogenic activation of materials

    NASA Astrophysics Data System (ADS)

    Amaré, J.; Beltrán, B.; Capelli, S.; Capozzi, F.; Carmona, J. M.; Cebrián, S.; Cremonesi, O.; García, E.; Irastorza, I. G.; Gómez, H.; Luzón, G.; Martínez, M.; Morales, J.; Ortiz de Solórzano, A.; Pavan, M.; Pobes, C.; Puimedón, J.; Rodríguez, A.; Ruz, J.; Sarsa, M. L.; Torres, L.; Villar, J. A.

    2005-09-01

    The problem of cosmogenic activation produced at sea level in materials typically used in underground experiments looking for rare events is being studied. Several nuclear data libraries have been screened looking for relevant isotope production cross-sections and different codes which can be applied to activation studies have been reviewed. The excitation functions for some problems of interest like production of 60Co and 68Ge in germanium and production of 60Co in tellurium have been obtained taking into account both measurements and calculations and a preliminary estimate of the corresponding rates of production at sea level has been performed.

  9. A conformational switch controls cell wall-remodelling enzymes required for bacterial cell division.

    PubMed

    Yang, Desirée C; Tan, Kemin; Joachimiak, Andrzej; Bernhardt, Thomas G

    2012-08-01

    Remodelling of the peptidoglycan (PG) exoskeleton is intimately tied to the growth and division of bacteria. Enzymes that hydrolyse PG are critical for these processes, but their activities must be tightly regulated to prevent the generation of lethal breaches in the PG matrix. Despite their importance, the mechanisms regulating PG hydrolase activity have remained elusive. Here we investigate the control of cell division hydrolases called amidases (AmiA, AmiB and AmiC) required for Escherichia coli cell division. Poorly regulated amiB mutants were isolated encoding lytic AmiB variants with elevated basal PG hydrolase activities in vitro. The structure of an AmiB orthologue was also solved, revealing that the active site of AmiB is occluded by a conserved alpha helix. Strikingly, most of the amino acid substitutions in the lytic AmiB variants mapped to this domain and are predicted to disrupt its interaction with the active site. Our results therefore support a model in which cell separation is stimulated by the reversible relief of amidase autoinhibition governed by conserved subcomplexes within the cytokinetic ring. Analogous conformational control mechanisms are likely to be part of a general strategy used to control PG hydrolases present within multienzyme PG-remodelling machines.

  10. [Problem Solving Activities.

    ERIC Educational Resources Information Center

    Wisconsin Univ. - Stout, Menomonie. Center for Vocational, Technical and Adult Education.

    The teacher directed problem solving activities package contains 17 units: Future Community Design, Let's Build an Elevator, Let's Construct a Catapult, Let's Design a Recreational Game, Let's Make a Hand Fishing Reel, Let's Make a Wall Hanging, Let's Make a Yo-Yo, Marooned in the Past, Metrication, Mousetrap Vehicles, The Multi System…

  11. [Biological activity of Spirulina].

    PubMed

    Blinkova, L P; Gorobets, O B; Baturo, A P

    2001-01-01

    In this review information of Spirulina platensis (SP), a blue-green alga (photosynthesizing cyanobacterium) having diverse biological activity is presented. Due to high content of highly valuable proteins, indispensable amino acids, vitamins, beta-carotene and other pigments, mineral substances, indispensable fatty acids and polysaccharides, PS has been found suitable for use as bioactive additive. SP produces an immunostimulating effect by enhancing the resistance of humans, mammals, chickens and fish to infections, the capacity of influencing hemopoiesis, stimulating the production of antibodies and cytokines. Under the influence of SP macrophages, T and B cells are activated. SP sulfolipids have proved to be effective against HIV. Preparations obtained from SP biomass have also been found active against herpesvirus, cytomegalovirus, influenza virus, etc. SP extracts are capable in inhibiting cancerogenesis. SP preparations are regarded as functional products contributing to the preservation of the resident intestinal microflora, especially lactic acid bacilli and bifidobacteria, and to a decrease in the level of Candida albicans. The biological activity of SP with respect to microorganisms holds good promise for using these microalgae as components of culture media.

  12. Active Authentication: Beyond Passwords

    DTIC Science & Technology

    2011-11-18

    semantic analysis (how you construct sentences); Forensic authorship Keystroke pattern; Mouse movement Fingerprint ; Iris pattern; Vein...Solutions Physiological Biometrics Sensors tracking the physical attributes of you • DNA • Ear Geometry • Facial Geometry • Fingerprint • Iris...Preview Fingerprint Forensic authorship2 Mouse tracking1 How you behave Physical aspects of you The context you exist in • The Active Authentication

  13. An Active Attraction.

    ERIC Educational Resources Information Center

    Burns, Joseph C.; Buzzelli, Cary

    1992-01-01

    Describes a unit on magnetism that utilizes hands-on activities in which students make hypotheses for discrepant behavior, discover whether a magnet attracts one object through another, measure the strength of magnets, explore levitating paper clips, and play a game dependent on magnetic attraction. (MDH)

  14. Active control system trends

    NASA Technical Reports Server (NTRS)

    Yore, E. E.; Gunderson, D. C.

    1976-01-01

    The active control concepts which achieve the benefit of improved mission performance and lower cost and generate system trends towards improved dynamic performance, more integration, and digital fly by wire mechanization are described. Analytical issues and implementation requirements and tools and approaches developed to address the analytical and implementation issues are briefly discussed.

  15. Arsenic activation neutron detector

    DOEpatents

    Jacobs, Eddy L.

    1981-01-01

    A detector of bursts of neutrons from a deuterium-deuteron reaction includes a quantity of arsenic adjacent a gamma detector such as a scintillator and photomultiplier tube. The arsenic is activated by the 2.5 Mev neutrons to release gamma radiation which is detected to give a quantitative representation of detected neutrons.

  16. Arsenic activation neutron detector

    DOEpatents

    Jacobs, E.L.

    1980-01-28

    A detector of bursts of neutrons from a deuterium-deuteron reaction includes a quantity of arsenic adjacent a gamma detector such as a scintillator and photomultiplier tube. The arsenic is activated by the 2.5-MeV neutrons to release gamma radiation which is detected to give a quantitative representation of detected neutrons.

  17. Earthfest. Activity Book.

    ERIC Educational Resources Information Center

    Weilbacher, Mike

    1991-01-01

    An activity book to help elementary teachers and students explore the environment offers information and questions about spaceships; an ecology primer and poster with questions; information on animal adaptation with poster and questions; ecological and dramatic arts projects; a script for performance; and suggestions to make Earth Day celebrations…

  18. Regional Activities Division. Papers.

    ERIC Educational Resources Information Center

    International Federation of Library Associations, The Hague (Netherlands).

    Papers on library network activities in Canada, the Third World, Japan, Malaysia, Brazil, and Sweden which were presented at the 1982 International Federation of Library Associations (IFLA) conference include: (1) "Canada: A Voluntary and Flexible Network," a review by Guy Sylvestre of the political, social, and economic structures…

  19. Learning Activity Package, Algebra.

    ERIC Educational Resources Information Center

    Evans, Diane

    A set of ten teacher-prepared Learning Activity Packages (LAPs) in beginning algebra and nine in intermediate algebra, these units cover sets, properties of operations, number systems, open expressions, solution sets of equations and inequalities in one and two variables, exponents, factoring and polynomials, relations and functions, radicals,…

  20. Educating for Political Activity

    ERIC Educational Resources Information Center

    Chitty, Clyde

    2010-01-01

    The term "political activity" can be interpreted in a myriad of different ways, but in this paper, it is taken to mean involvement in a variety of campaigns around issues affecting the way we live and the sort of society we want to live in. At a time when support for the main political parties has never been weaker, it is essential that…

  1. Active microwave water equivalence

    NASA Technical Reports Server (NTRS)

    Boyne, H. S.; Ellerbruch, D. A.

    1980-01-01

    Measurements of water equivalence using an active FM-CW microwave system were conducted over the past three years at various sites in Colorado, Wyoming, and California. The measurement method is described. Measurements of water equivalence and stratigraphy are compared with ground truth. A comparison of microwave, federal sampler, and snow pillow measurements at three sites in Colorado is described.

  2. Active Learning Methods

    ERIC Educational Resources Information Center

    Zayapragassarazan, Z.; Kumar, Santosh

    2012-01-01

    Present generation students are primarily active learners with varied learning experiences and lecture courses may not suit all their learning needs. Effective learning involves providing students with a sense of progress and control over their own learning. This requires creating a situation where learners have a chance to try out or test their…

  3. Bonus Activity Book.

    ERIC Educational Resources Information Center

    Learning, 1993

    1993-01-01

    Elementary level activity book presents suggestions for teaching students about endangered and threatened species worldwide. Students learn about what is causing the rapid extinction rate and what needs to be done. They also discover the value of rainforests and why conservationists are fighting to save them. (SM)

  4. Macrophage activation and polarization.

    PubMed

    Martinez, Fernando Oneissi; Sica, Antonio; Mantovani, Alberto; Locati, Massimo

    2008-01-01

    Macrophages are widely distributed immune system cells that play an indispensable role in homeostasis and defense. They can be phenotypically polarized by the microenvironment to mount specific functional programs. Polarized macrophages can be broadly classified in two main groups: classically activated macrophages (or M1), whose prototypical activating stimuli are IFNgamma and LPS, and alternatively activated macrophages (or M2), further subdivided in M2a (after exposure to IL-4 or IL-13), M2b (immune complexes in combination with IL-1beta or LPS) and M2c (IL-10, TGFbeta or glucocorticoids). M1 exhibit potent microbicidal properties and promote strong IL-12-mediated Th1 responses, whilst M2 support Th2-associated effector functions. Beyond infection M2 polarized macrophages play a role in resolution of inflammation through high endocytic clearance capacities and trophic factor synthesis, accompanied by reduced pro-inflammatory cytokine secretion. Similar functions are also exerted by tumor-associated macrophages (TAM), which also display an alternative-like activation phenotype and play a detrimental pro-tumoral role. Here we review the main functions of polarized macrophages and discuss the perspectives of this field.

  5. Active Ingredient - AZ

    EPA Pesticide Factsheets

    EPA Pesticide Chemical Search allows a user to easily find the pesticide chemical or active ingredient that they are interested in by using an array of simple to advanced search options. Chemical Search provides a single point of reference for easy access to information previously published in a variety of locations, including various EPA web pages and Regulations.gov.

  6. Shark Tagging Activities.

    ERIC Educational Resources Information Center

    Current: The Journal of Marine Education, 1998

    1998-01-01

    In this group activity, children learn about the purpose of tagging and how scientists tag a shark. Using a cut-out of a shark, students identify, measure, record data, read coordinates, and tag a shark. Includes introductory information about the purpose of tagging and the procedure, a data sheet showing original tagging data from Tampa Bay, and…

  7. Engineers and Active Responsibility.

    PubMed

    Pesch, Udo

    2015-08-01

    Knowing that technologies are inherently value-laden and systemically interwoven with society, the question is how individual engineers can take up the challenge of accepting the responsibility for their work? This paper will argue that engineers have no institutional structure at the level of society that allows them to recognize, reflect upon, and actively integrate the value-laden character of their designs. Instead, engineers have to tap on the different institutional realms of market, science, and state, making their work a 'hybrid' activity combining elements from the different institutional realms. To deal with this institutional hybridity, engineers develop routines and heuristics in their professional network, which do not allow societal values to be expressed in a satisfactory manner. To allow forms of 'active' responsibility, there have to be so-called 'accountability forums' that guide moral reflections of individual actors. The paper will subsequently look at the methodologies of value-sensitive design (VSD) and constructive technology assessment (CTA) and explore whether and how these methodologies allow engineers to integrate societal values into the design technological artifacts and systems. As VSD and CTA are methodologies that look at the process of technological design, whereas the focus of this paper is on the designer, they can only be used indirectly, namely as frameworks which help to identify the contours of a framework for active responsibility of engineers.

  8. Activities: Visualization, Estimation, Computation.

    ERIC Educational Resources Information Center

    Maletsky, Evan M.

    1982-01-01

    The material is designed to help students build a cone model, visualize how its dimensions change as its shape changes, estimate maximum volume position, and develop problem-solving skills. Worksheets designed for duplication for classroom use are included. Part of the activity involves student analysis of a BASIC program. (MP)

  9. Intermittent Activity in AGN

    NASA Astrophysics Data System (ADS)

    Janiuk, A.; Czerny, B.; Siemiginowska, A.

    2004-10-01

    There is a growing evidence that the AGN activity could be intermittent. It remains an open question if this behavior is caused by changes in the fuel sup- ply to the supermassive black hole from the large distances, or rather by a processes intrinsic to the active nucleus. We consider the possibility that ac- cretion onto a supermassive black hole is controlled by an accretion disk which is subject to the hydro- gen ionization instability. This drives the observed on-off activity cycle, since periodically the accretion flow becomes inefficient and the disk goes to quies- cence. We consider effects of the MHD turbulence on the viscosity during the evolution of a standard α - disk. We perform a self-consistency check of the α de- scription of the angular momentum transfer. Hav- ing shown that the viscosity parameter is constant throughout the whole instability cycle, as implied by the strength of the MHD turbulence, we calcu- late the time evolution of the disk under the influ- ence of the ionization instability. We demonstrate that if the accretion onto a supermassive black hole proceeds through an outer standard accretion disk and inner, radiatively inefficient and advection dom- inated flow, the modelled amplitudes of disk lumi- nosity variations are sufficiently high to account for the observations. Key words: accretion disks; galaxies: active.

  10. Highlights of 1976 activities

    NASA Technical Reports Server (NTRS)

    Fitzpatrick, M.

    1976-01-01

    Highlights of NASA's 1976 activities are summarized. Sixteen successful launches were made. Two landings of Viking spacecraft on Mars and rollout of the space shuttle orbiter are reviewed. Applications of aerospace science to education, health care, and community services are also discussed.

  11. Activities from Asia.

    ERIC Educational Resources Information Center

    Texas Child Care, 1995

    1995-01-01

    Notes that the best way to learn about another culture is to know how its habits, traditions, and environments differ from or resemble our own. Provides several activities to help young children understand Asian cultures, including cooking, origami, and games and festivals. (HTH)

  12. Highlights of 1978 activities

    NASA Technical Reports Server (NTRS)

    1978-01-01

    General highlights of NASA's activities for 1978 are presented. The highlights are categorized into topics such as space science, space transportation systems, space and terrestrial applications, environment, technology utilization, aeronautics, space research and technology, energy programs, and international. A list of the 1978 launches including: (1) launch date; (2) payload designation; (3) launch vehicle; (4) launch site and (5) mission remarks is also presented.

  13. Multidisciplinary Wildlife Teaching Activities.

    ERIC Educational Resources Information Center

    Hernbrode, William R., Ed.

    This guide provides information and activities descriptions designed to allow the teacher to use wildlife concepts in the teaching of various subjects. The author suggests that wildlife and animals are tremendous motivators for children and hold their attention. In the process, concepts of wildlife interaction with man and the environment are…

  14. Active-bridge oscillator

    DOEpatents

    Wessendorf, Kurt O.

    2001-01-01

    An active bridge oscillator is formed from a differential amplifier where positive feedback is a function of the impedance of one of the gain elements and a relatively low value common emitter resistance. This use of the nonlinear transistor parameter h stabilizes the output and eliminates the need for ALC circuits common to other bridge oscillators.

  15. Immunizations: Active vs. Passive

    MedlinePlus

    ... a certain type of wild animal bites a child. Passive immunizations for hepatitis A (gamma globulin) may be helpful ... A is common. They are typically given before children or adults leave on their ... active vaccination is preferable. Keep in mind that passive immunizations ...

  16. 85 Engaging Movement Activities.

    ERIC Educational Resources Information Center

    Weikart, Phyllis S.; Carlton, Elizabeth B.

    This book presents activities to keep K-6 students moving in a variety of ways as they learn. The movement experiences are planned around key curriculum concepts in movement and music as well as in academic curriculum areas. The experiences develop students' basic timing, language abilities, vocabulary, concentration, planning skills, and…

  17. Classification of Physical Activity

    PubMed Central

    Turksoy, Kamuran; Paulino, Thiago Marques Luz; Zaharieva, Dessi P.; Yavelberg, Loren; Jamnik, Veronica; Riddell, Michael C.; Cinar, Ali

    2015-01-01

    Physical activity has a wide range of effects on glucose concentrations in type 1 diabetes (T1D) depending on the type (ie, aerobic, anaerobic, mixed) and duration of activity performed. This variability in glucose responses to physical activity makes the development of artificial pancreas (AP) systems challenging. Automatic detection of exercise type and intensity, and its classification as aerobic or anaerobic would provide valuable information to AP control algorithms. This can be achieved by using a multivariable AP approach where biometric variables are measured and reported to the AP at high frequency. We developed a classification system that identifies, in real time, the exercise intensity and its reliance on aerobic or anaerobic metabolism and tested this approach using clinical data collected from 5 persons with T1D and 3 individuals without T1D in a controlled laboratory setting using a variety of common types of physical activity. The classifier had an average sensitivity of 98.7% for physiological data collected over a range of exercise modalities and intensities in these subjects. The classifier will be added as a new module to the integrated multivariable adaptive AP system to enable the detection of aerobic and anaerobic exercise for enhancing the accuracy of insulin infusion strategies during and after exercise. PMID:26443291

  18. Production Systems. Laboratory Activities.

    ERIC Educational Resources Information Center

    Gallaway, Ann, Ed.

    This production systems guide provides teachers with learning activities for secondary students. Introductory materials include an instructional planning outline and worksheet, an outline of essential elements, domains and objectives, a course description, and a content outline. The guide contains 30 modules on the following topics: production…

  19. Dissemination Activities Report

    ERIC Educational Resources Information Center

    Barclay, Hanna; Batatia, Hudj; Bauters, Merja; Ben Ami, Zvi; Drachman, Raul; Flouris, Giorgos; Jadin, Tanja; Jalonen, Satu; Karlgren, Klas; Karpati, Andrea; Kotzinos, Dimitris; Lakkala, Minna; Lallimo, Jiri; Moen, Anne; Nygard, Kathrine; Paavola, Sami; Padiglia, Sheila; Scapolla, Marina; Sins, Patrick; Vasileva, Tania

    2008-01-01

    In the first 24 months of the project, KP-Lab members were highly dedicated to dissemination and were engaged in various dissemination activities that contributed to the prime objective of the KP-Lab dissemination efforts which is "to make the project widely known to a variety of prospective users and, at a later stage, to promote the…

  20. Designing Metacognitive Activities.

    ERIC Educational Resources Information Center

    Lin, Xiaodong

    2001-01-01

    Proposes a framework for thinking about how metacognition research might apply to design activities. Examines two basic approaches to supporting metacognition: strategy training, and creation of a supportive social environment for metacognition. Identifies two kinds of content that are taught using these two approaches: knowledge about a specific…

  1. Geology: The Active Earth.

    ERIC Educational Resources Information Center

    Braus, Judy, Ed.

    1987-01-01

    Ranger Rick's NatureScope is a creative education series dedicated to inspiring in children an understanding and appreciation of the natural world while developing the skills they will need to make responsible decisions about the environment. The topic of this issue is "Geology: The Active Earth." Contents are organized into the…

  2. Marketing coprovided activities.

    PubMed

    Dickerson, Pamela S

    2014-05-01

    Coproviding is a wonderful way for two or more organizations to work together to provide continuing nursing education. To be transparent to the learners, marketing materials identify the parties involved and prominently note the name of the organization accountable for developing the activity and awarding the contact hours.

  3. Communication Systems. Laboratory Activities.

    ERIC Educational Resources Information Center

    Sutherland, Barbara, Ed.

    This communication systems guide provides teachers with learning activities for secondary students. Introductory materials include an instructional planning outline and worksheet, an outline of essential elements, a list of objectives, a course description, and a content outline. The guide contains 32 modules on the following topics: story…

  4. Chaperone activation by unfolding.

    PubMed

    Foit, Linda; George, Jenny S; Zhang, Bin W; Brooks, Charles L; Bardwell, James C A

    2013-04-02

    Conditionally disordered proteins can alternate between highly ordered and less ordered configurations under physiological conditions. Whereas protein function is often associated with the ordered conformation, for some of these conditionally unstructured proteins, the opposite applies: Their activation is associated with their unfolding. An example is the small periplasmic chaperone HdeA, which is critical for the ability of enteric bacterial pathogens like Escherichia coli to survive passage through extremely acidic environments, such as the human stomach. At neutral pH, HdeA is a chaperone-inactive dimer. On a shift to low pH, however, HdeA monomerizes, partially unfolds, and becomes rapidly active in preventing the aggregation of substrate proteins. By mutating two aspartic acid residues predicted to be responsible for the pH-dependent monomerization of HdeA, we have succeeded in isolating an HdeA mutant that is active at neutral pH. We find this HdeA mutant to be substantially destabilized, partially unfolded, and mainly monomeric at near-neutral pH at a concentration at which it prevents aggregation of a substrate protein. These results provide convincing evidence for direct activation of a protein by partial unfolding.

  5. Ocean Drilling Simulation Activity.

    ERIC Educational Resources Information Center

    Telese, James A.; Jordan, Kathy

    The Ocean Drilling Project brings together scientists and governments from 20 countries to explore the earth's structure and history as it is revealed beneath the oceans' basins. Scientific expeditions examine rock and sediment cores obtained from the ocean floor to learn about the earth's basic processes. The series of activities in this…

  6. Organizing Preservation Activities.

    ERIC Educational Resources Information Center

    Cloonan, Michele

    This resource guide considers issues in the staffing and organization of preservation activities. It provides guidance in implementing a systematic preservation program and evaluates the structures of various types of preservation programs. The following articles complement the discussion of program models and implementation: (1)…

  7. Activities: Some Colorful Mathematics.

    ERIC Educational Resources Information Center

    DeTemple, Duane W.; Walker, Dean A.

    1996-01-01

    Describes three activities in discrete mathematics that involve coloring geometric objects: counting colored regions of overlapping simple closed curves, counting colored triangulations of polygons, and determining the number of colors required to paint the plane so that no two points one inch apart are the same color. (MKR)

  8. Physical Activities for Preschool.

    ERIC Educational Resources Information Center

    Adkins, Dorothy C.; And Others

    The underlying premise of the University of Hawaii Physical Activities for Preschool curriculum is that important contributions to a positive self-concept are made by motor independence and a realistic body image. Program objectives include: (1) the development of strength, endurance, and flexibility in skills that involve the muscles,…

  9. Activating silent argonautes.

    PubMed

    Kidwell, Mary Anne; Doudna, Jennifer A

    2013-07-01

    Multiple Argonaute proteins are implicated in gene silencing by RNA interference (RNAi), but only one is known to be an endonuclease that can cleave target mRNAs. Chimeric Argonaute proteins now reveal an unexpected mechanism by which mutations distal to the catalytic center can unmask intrinsic catalytic activity, results hinting at structurally mediated regulation.

  10. Commission 10: Solar Activity

    NASA Astrophysics Data System (ADS)

    van Driel-Gesztelyi, Lidia; Schrijver, Carolus J.; Klimchuk, James A.; Charbonneau, Paul; Fletcher, Lyndsay; Hasan, S. Sirajul; Hudson, Hugh S.; Kusano, Kanya; Mandrini, Cristina H.; Peter, Hardi; Vršnak, Bojan; Yan, Yihua

    2012-04-01

    Commission 10 of the International Astronomical Union has more than 650 members who study a wide range of activity phenomena produced by our nearest star, the Sun. Solar activity is intrinsically related to solar magnetic fields and encompasses events from the smallest energy releases (nano- or even picoflares) to the largest eruptions in the Solar System, coronal mass ejections (CMEs), which propagate into the Heliosphere reaching the Earth and beyond. Solar activity is manifested in the appearance of sunspot groups or active regions, which are the principal sources of activity phenomena from the emergence of their magnetic flux through their dispersion and decay. The period 2008-2009 saw an unanticipated extended solar cycle minimum and unprecedentedly weak polar-cap and heliospheric field. Associated with that was the 2009 historical maximum in galactic cosmic rays flux since measurements begun in the middle of the 20th Century. Since then Cycle 24 has re-started solar activity producing some spectacular eruptions observed with a fleet of spacecraft and ground-based facilities. In the last triennium major advances in our knowledge and understanding of solar activity were due to continuing success of space missions as SOHO, Hinode, RHESSI and the twin STEREO spacecraft, further enriched by the breathtaking images of the solar atmosphere produced by the Solar Dynamic Observatory (SDO) launched on 11 February 2010 in the framework of NASA's Living with a Star program. In August 2012, at the time of the IAU General Assembly in Beijing when the mandate of this Commission ends, we will be in the unique position to have for the first time a full 3-D view of the Sun and solar activity phenomena provided by the twin STEREO missions about 120 degrees behind and ahead of Earth and other spacecraft around the Earth and ground-based observatories. These new observational insights are continuously posing new questions, inspiring and advancing theoretical analysis and

  11. 45 CFR 1226.8 - Prohibited activities.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... SERVICE PROHIBITIONS ON ELECTORAL AND LOBBYING ACTIVITIES Volunteer Activities § 1226.8 Prohibited activities. (a) Electoral Activity. Volunteers shall not engage in any activity which may, directly...

  12. Interdisciplinary Astronomy Activities

    NASA Astrophysics Data System (ADS)

    Nerantzis, Nikolaos; Mitrouda, Aikaterini; Reizopoulou, Ioanna; Sidiropoulou, Eirini; Hatzidimitriou, Antonios

    2016-04-01

    On November 9th, 2015, three didactical hours were dedicated to Interdisciplinary Astronomy Activities (http://wp.me/p6Hte2-1I). Our students and their teachers formed three groups and in rotation, were engaged with the following activities: (a) viewing unique images of the Cosmos in the mobile planetarium STARLAB (http://www.planitario.gr/tholos-starlab-classic-standard.html), (b) watching the following videos: Journey to the end of the universe (https://youtu.be/Ufl_Nwbl8xs), Rosetta update (https://youtu.be/nQ9ivd7wv30), The Solar System (https://youtu.be/d66dsagrTa0), Ambition the film (https://youtu.be/H08tGjXNHO4) in the school's library. Students and teachers were informed about our solar system, the Rosetta mission, the universe, etc. and (c) tactile activities such as Meet our home and Meet our neighbors (http://astroedu.iau.org, http://nuclio.org/astroneighbours/resources) and the creation of planets' 3D models (Geology-Geography A' Class Student's book, pg.15). With the activities above we had the pleasure to join the Cosmic Light Edu Kit / International Year of Light 2015 program. After our Interdisciplinary Astronomy Activities, we did a "small" research: our students had to fill an evaluation about their educational gains and the results can be found here http://wp.me/p6Hte2-2q. Moreover, we discussed about Big Ideas of Science (http://wp.me/p3oRiZ-dm) and through the "big" impact of the Rosetta mission & the infinity of our universe, we print posters with relevant topics and place them to the classrooms. We thank Rosa Doran (Nuclio - President of the Executive Council) for her continuous assistance and support on innovative science teaching proposals. She is an inspiration.

  13. Activities. Inductive and Deductive Reasoning.

    ERIC Educational Resources Information Center

    O'Daffer, Phares G.; And Others

    1990-01-01

    Provided are the activity sheets for students and the teaching guide for this middle school geometry activity. Materials, prerequisites, objectives, and procedures are listed. Extension activities are suggested. An answer key is included. (CW)

  14. 101 Environmental Education Activities. Booklet 6--Social Studies Activities.

    ERIC Educational Resources Information Center

    Whitney, Helen, Comp.

    Based on the environment and directed at elementary and intermediate level students, 5 field trips are a significant part of the 12 social studies activities in the sixth booklet by the Upper Mississippi River ECO-Center outlining environmental and outdoor education activities. Most of the activities include objectives, activity description,…

  15. Integration of Active Video Games in Extracurricular Activity at Schools

    ERIC Educational Resources Information Center

    Lee, Jung Eun; Huang, Charles; Pope, Zachary; Gao, Zan

    2015-01-01

    Active video games require players to be physically active. Dance Dance Revolution (DDR) is an interactive dancing game that requires fast-foot movement coordinated with energetic music and visuals. The Wii and Xbox Kinect games have also become good active video games for the promotion of physical activity participation. These games are much more…

  16. Is Enhanced Physical Activity Possible Using Active Videogames?

    PubMed

    Baranowski, Tom; Baranowski, Janice; O'Connor, Teresia; Lu, Amy Shirong; Thompson, Debbe

    2012-06-01

    Our research indicated that 10-12-year-old children receiving two active Wii(™) (Nintendo(®); Nintendo of America, Inc., Redmond, WA) console videogames were no more physically active than children receiving two inactive videogames. Research is needed on how active videogames may increase physical activity.

  17. Active braze process

    SciTech Connect

    Levine, I.L.; Pike, R.A.

    1990-11-02

    Active metal bonding using Cusil (silver-copper) braze alloys is a well established method used at GE Neutron Devices (GEND) for bonding metal to metal, metal to ceramics, and ceramics to ceramics. However, there are many instances in which using a silver alloy for bonding is undesirable (e.g., in vacuum tube envelopes, or where sequential braze steps at different temperatures are required to complete an assembly). The Material and Processes Laboratory at GEND has discovered a new method of active brazing with non-silver alloys which has proved especially successful in ceramic-to-ceramic joints. This method has the added advantage of eliminating several steps which are required in conventional bonding techniques. 2 figs., 10 tabs.

  18. Myofilament length dependent activation.

    PubMed

    de Tombe, Pieter P; Mateja, Ryan D; Tachampa, Kittipong; Ait Mou, Younss; Farman, Gerrie P; Irving, Thomas C

    2010-05-01

    The Frank-Starling law of the heart describes the interrelationship between end-diastolic volume and cardiac ejection volume, a regulatory system that operates on a beat-to-beat basis. The main cellular mechanism that underlies this phenomenon is an increase in the responsiveness of cardiac myofilaments to activating Ca(2+) ions at a longer sarcomere length, commonly referred to as myofilament length-dependent activation. This review focuses on what molecular mechanisms may underlie myofilament length dependency. Specifically, the roles of inter-filament spacing, thick and thin filament based regulation, as well as sarcomeric regulatory proteins are discussed. Although the "Frank-Starling law of the heart" constitutes a fundamental cardiac property that has been appreciated for well over a century, it is still not known in muscle how the contractile apparatus transduces the information concerning sarcomere length to modulate ventricular pressure development.

  19. Mount Erebus activity

    NASA Astrophysics Data System (ADS)

    An international team of scientists reports that unusually high seismic activity joggled Mount Erebus last fall. However, the Antarctic volcano showed no external signs of an eruption.When scientists from the United States, Japan, and New Zealand returned to the world's southernmost active volcano last November for their annual field expedition, they found that seismic stations recorded 650 small tremors on October 8; prior to that, the number of quakes had averaged between 20 and 80 per day. The October 8 maximum was followed by 140 on October 9 and 120 on October 10. Philip R. Kyle, assistant professor of geochemistry at the New Mexico Institute of Mining and Technology in Socorro and leader of the team studying Mount Erebus, noted that some of the strongest earthquakes recorded during the team's 3 years of observations occurred on October 8; these registered less than 2 on the Richter scale.

  20. UNESCO's activities in ethics.

    PubMed

    ten Have, Henk A M J

    2010-03-01

    UNESCO is an intergovernmental organization with 193 Member States. It is concerned with a broad range of issues regarding education, science and culture. It is the only UN organisation with a mandate in science. Since 1993 it is addressing ethics of science and technology, with special emphasis on bioethics. One major objective of the ethics programme is the development of international normative standards. This is particularly important since many Member States only have a limited infrastructure in bioethics, lacking expertise, educational programs, bioethics committees and legal frameworks. UNESCO has recently adopted the Universal Declaration on Bioethics and Human Rights. The focus of current activities is now on implementation of this Declaration. Three activities are discussed that aim at improving and reinforcing the ethics infrastructure in relation to science and technology: the Global Ethics Observatory, the Ethics Education Programme and the Assisting Bioethics Committees project.

  1. LANSCE Activity Report

    SciTech Connect

    Amy Robinson; Audrey Archuleta; Barbara Maes; Dan Strottman; Earl Hoffman; Garth Tietjen; Gene Farnum; Geoff Greene; Joyce Roberts; Ken Johnson; Paul Lewis; Roger Pynn; Stan Schriber; Steve Sterbenz; Steve Wender; Sue Harper

    1999-02-01

    The Los Alamos Neutron Science Center Activity Report describes scientific and technological progress and achievements in LANSCE Division during the period of 1995 to 1998. This report includes a message from the Division Director, an overview of LANSCE, sponsor overviews, research highlights, advanced projects and facility upgrades achievements, experimental and user program accomplishments, news and events, and a list of publications. The research highlights cover the areas of condensed-matter science and engineering, accelerator science, nuclear science, and radiography. This report also contains a compact disk that includes an overview, the Activity Report itself, LANSCE operations progress reports for 1996 and 1997, experiment reports from LANSCE users, as well as a search capability.

  2. Myofilament length dependent activation

    SciTech Connect

    de Tombe, Pieter P.; Mateja, Ryan D.; Tachampa, Kittipong; Mou, Younss Ait; Farman, Gerrie P.; Irving, Thomas C.

    2010-05-25

    The Frank-Starling law of the heart describes the interrelationship between end-diastolic volume and cardiac ejection volume, a regulatory system that operates on a beat-to-beat basis. The main cellular mechanism that underlies this phenomenon is an increase in the responsiveness of cardiac myofilaments to activating Ca{sup 2+} ions at a longer sarcomere length, commonly referred to as myofilament length-dependent activation. This review focuses on what molecular mechanisms may underlie myofilament length dependency. Specifically, the roles of inter-filament spacing, thick and thin filament based regulation, as well as sarcomeric regulatory proteins are discussed. Although the 'Frank-Starling law of the heart' constitutes a fundamental cardiac property that has been appreciated for well over a century, it is still not known in muscle how the contractile apparatus transduces the information concerning sarcomere length to modulate ventricular pressure development.

  3. Techniques for active passivation

    SciTech Connect

    Roscioli, Joseph R.; Herndon, Scott C.; Nelson, Jr., David D.

    2016-12-20

    In one embodiment, active (continuous or intermittent) passivation may be employed to prevent interaction of sticky molecules with interfaces inside of an instrument (e.g., an infrared absorption spectrometer) and thereby improve response time. A passivation species may be continuously or intermittently applied to an inlet of the instrument while a sample gas stream is being applied. The passivation species may have a highly polar functional group that strongly binds to either water or polar groups of the interfaces, and once bound presents a non-polar group to the gas phase in order to prevent further binding of polar molecules. The instrument may be actively used to detect the sticky molecules while the passivation species is being applied.

  4. Nematicidal activity of terpenoids.

    PubMed

    Abdel-Rahman, Fawzia H; Alaniz, Nina M; Saleh, Mahmoud A

    2013-01-01

    Thirty four phytoterpenoids were evaluated for their nematicidal effect using the model nematode Caenorhabditis elegans. Nematicidal activities of the tested compounds at concentrations of 50 μg/mL showed wide variation in their effects ranging from no effect, weak, moderate and strong effects. Terpenoids exerting 50% or higher mortality at 50 μg/mL were further tested at five different concentrations to calculate the concentration that will kill 50% of the nematode population (LC(50)). Among the most effective terpenoids were carvacrol, thymol, nerolidol, α-terpinene, geraniol, citronellol, farnesol, limonene, pseudoionone and eugenol in a descending order. These compounds exhibited a dose-dependent effect. The results suggest that the selected monoterpenoids and essential oils with a high concentration of these compounds mayprovide potential natural nematicides and merit further study as botanical nematicides for the control of both plant and animal parasitic nematodes. In general, oxygenated terpenoids and phenolic terpenoids exhibited higher nematicidal activity than hydrocarbons terpenoids.

  5. Active region seismology

    NASA Technical Reports Server (NTRS)

    Bogdan, Tom; Braun, D. C.

    1995-01-01

    Active region seismology is concerned with the determination and interpretation of the interaction of the solar acoustic oscillations with near-surface target structures, such as magnetic flux concentration, sunspots, and plage. Recent observations made with a high spatial resolution and a long temporal duration enabled measurements of the scattering matrix for sunspots and solar active regions to be carried out as a function of the mode properties. Based on this information, the amount of p-mode absorption, partial-wave phase shift, and mode mixing introduced by the sunspot, could be determined. In addition, the possibility of detecting the presence of completely submerged magnetic fields was raised, and new procedures for performing acoustic holography of the solar interior are being developed. The accumulating evidence points to the mode conversion of p-modes to various magneto-atmospheric waves within the magnetic flux concentration as being the unifying physical mechanism responsible for these diverse phenomena.

  6. Cisplatin triggers platelet activation.

    PubMed

    Togna, G I; Togna, A R; Franconi, M; Caprino, L

    2000-09-01

    Clinical observations suggest that anticancer drugs could contribute to the thrombotic complications of malignancy in treated patients. Thrombotic microangiopathy, myocardial infarction, and cerebrovascular thrombotic events have been reported for cisplatin, a drug widely used in the treatment of many solid tumours. The aim of this study is to explore in vitro cisplatin effect on human platelet reactivity in order to define the potentially active role of platelets in the pathogenesis of cisplatin-induced thrombotic complications. Our results demonstrate that cisplatin increases human platelet reactivity (onset of platelet aggregation wave and thromboxane production) to non-aggregating concentrations of the agonists involving arachidonic acid metabolism. Direct or indirect activation of platelet phospholipase A(2) appears to be implicated. This finding contributes to a better understanding of the pathogenesis of thrombotic complications occurring during cisplatin-based chemotherapy.

  7. Active optical zoom system.

    PubMed

    Wang, Di; Wang, Qiong-Hua; Shen, Chuan; Zhou, Xin; Liu, Chun-Mei

    2014-11-01

    In this work, we propose an active optical zoom system. The zoom module of the system is formed by a liquid lens and a spatial light modulator (SLM). By controlling the focal lengths of the liquid lens and the encoded digital lens on the SLM panel, we can change the magnification of an image without mechanical moving parts and keep the output plane stationary. The magnification can change from 1/3 to 3/2 as the focal length of the encoded lens on the SLM changes from infinity to 24 cm. The proposed active zoom system is simple and flexible, and has widespread application in optical communications, imaging systems, and displays.

  8. Active microchannel heat exchanger

    DOEpatents

    Tonkovich, Anna Lee Y [Pasco, WA; Roberts, Gary L [West Richland, WA; Call, Charles J [Pasco, WA; Wegeng, Robert S [Richland, WA; Wang, Yong [Richland, WA

    2001-01-01

    The present invention is an active microchannel heat exchanger with an active heat source and with microchannel architecture. The microchannel heat exchanger has (a) an exothermic reaction chamber; (b) an exhaust chamber; and (c) a heat exchanger chamber in thermal contact with the exhaust chamber, wherein (d) heat from the exothermic reaction chamber is convected by an exothermic reaction exhaust through the exhaust chamber and by conduction through a containment wall to the working fluid in the heat exchanger chamber thereby raising a temperature of the working fluid. The invention is particularly useful as a liquid fuel vaporizer and/or a steam generator for fuel cell power systems, and as a heat source for sustaining endothermic chemical reactions and initiating exothermic reactions.

  9. METABOLIC ENGINEERING TO DEVELOP A PATHWAY FOR THE SELECTIVE CLEAVAGE OF CARBON-NITROGEN BONDS

    SciTech Connect

    John J. Kilbane III

    2003-12-01

    The objective of the project is to develop biochemical pathways for the selective cleavage of C-N bonds in molecules found in petroleum. The initial phase of the project will focus on the isolation or development of an enzyme capable of cleaving the C-N bond in aromatic amides, specifically 2-aminobiphenyl. The objective of the second phase of the research will be to construct a biochemical pathway for the selective removal of nitrogen from carbazole by combining the carA genes from Sphingomonas sp. GTIN11 with the gene(s) encoding an appropriate amidase. The objective of the final phase of the project will be to develop derivative CN bond cleaving enzymes that have broader substrate ranges and to demonstrate the use of such strains to selectively remove nitrogen from petroleum. The project is on schedule and no major difficulties have been encountered. During the first year of the project (October, 2002-September, 2003) enrichment culture experiments have resulted in the isolation of promising cultures that may be capable of cleaving C-N bonds in aromatic amides, several amidase genes have been cloned and are currently undergoing directed evolution to obtain derivatives that can cleave C-N bonds in aromatic amides, and the carA genes from Sphingomonas sp. GTIN11, and Pseudomonas resinovorans CA10 were cloned in vectors capable of replicating in Escherichia coli. Future research will address expression of these genes in Rhodococcus erythropolis. Enrichment culture experiments and directed evolution experiments continue to be a main focus of research activity and further work is required to obtain an appropriate amidase that will selectively cleave C-N bonds in aromatic substrates. Once an appropriate amidase gene is obtained it must be combined with genes encoding an enzyme capable of converting carbazole to 2'aminobiphenyl-2,3-diol: specifically carA genes. The carA genes from two sources have been cloned and are ready for construction of C-N bond cleavage pathway

  10. Environmental health program activities

    NASA Technical Reports Server (NTRS)

    Bergtholdt, C. P.

    1969-01-01

    Activities reported include studies on toxic air contaminants, excessive noise, poor lighting, food sanitation, water pollution, and exposure to nonionizing radiation as health hazards. Formulations for a radiological health manual provide guidance to personnel in the procurement and safe handling of radiation producing equipment and Apollo mission planning. A literature search and development of a water analysis laboratory are outlined to obtain information regarding microbiological problems involving potable water, waste management, and personal hygiene.

  11. [Chronotropic activity of semax].

    PubMed

    Arushanian, E B; Popov, A V

    2008-01-01

    The chronic administration of nootropic drug Semax, a peptide analog of ACTH (4-10), normalized the circadian locomotor rhythm in rats (with an increase in its amplitude, a shift in the acrophase, and a change of the spectral characteristics) and reduced the integral chronobiological index. It is suggested that the rhythm-synchronizing chronotropic activity may be a part of the specific effect of this cognitive enhancer.

  12. Imaging nervous system activity.

    PubMed

    Fields, Douglas R; Shneider, Neil; Mentis, George Z; O'Donovan, Michael J

    2009-10-01

    This unit describes methods for loading ion- and voltage-sensitive dyes into neurons, with a particular focus on the spinal cord as a model system. In addition, we describe the use of these dyes to visualize neural activity. Although the protocols described here concern spinal networks in culture or an intact in vitro preparation, they can be, and have been, widely used in other parts of the nervous system.

  13. Assay of FAAH Activity.

    PubMed

    Bari, Monica; Feole, Monica; Maccarrone, Mauro

    2016-01-01

    Fatty acid amide hydrolase (FAAH) is an intracellular enzyme responsible for the hydrolysis of endogenous anandamide (AEA), a reaction that terminates the biological effects of this lipid mediator. The final products of this reaction are arachidonic acid and ethanolamine. In the method described herein, FAAH activity is measured through the use of a radioactive substrate by quantification of reaction products, that is, [(14)C]-ethanolamine from [(14)C-ethanolamine]-AEA.

  14. Active inference and learning.

    PubMed

    Friston, Karl; FitzGerald, Thomas; Rigoli, Francesco; Schwartenbeck, Philipp; O'Doherty, John; Pezzulo, Giovanni

    2016-09-01

    This paper offers an active inference account of choice behaviour and learning. It focuses on the distinction between goal-directed and habitual behaviour and how they contextualise each other. We show that habits emerge naturally (and autodidactically) from sequential policy optimisation when agents are equipped with state-action policies. In active inference, behaviour has explorative (epistemic) and exploitative (pragmatic) aspects that are sensitive to ambiguity and risk respectively, where epistemic (ambiguity-resolving) behaviour enables pragmatic (reward-seeking) behaviour and the subsequent emergence of habits. Although goal-directed and habitual policies are usually associated with model-based and model-free schemes, we find the more important distinction is between belief-free and belief-based schemes. The underlying (variational) belief updating provides a comprehensive (if metaphorical) process theory for several phenomena, including the transfer of dopamine responses, reversal learning, habit formation and devaluation. Finally, we show that active inference reduces to a classical (Bellman) scheme, in the absence of ambiguity.

  15. Active Brownian rods

    NASA Astrophysics Data System (ADS)

    Peruani, Fernando

    2016-11-01

    Bacteria, chemically-driven rods, and motility assays are examples of active (i.e. self-propelled) Brownian rods (ABR). The physics of ABR, despite their ubiquity in experimental systems, remains still poorly understood. Here, we review the large-scale properties of collections of ABR moving in a dissipative medium. We address the problem by presenting three different models, of decreasing complexity, which we refer to as model I, II, and III, respectively. Comparing model I, II, and III, we disentangle the role of activity and interactions. In particular, we learn that in two dimensions by ignoring steric or volume exclusion effects, large-scale nematic order seems to be possible, while steric interactions prevent the formation of orientational order at large scales. The macroscopic behavior of ABR results from the interplay between active stresses and local alignment. ABR exhibit, depending on where we locate ourselves in parameter space, a zoology of macroscopic patterns that ranges from polar and nematic bands to dynamic aggregates.

  16. Active polarization descattering.

    PubMed

    Treibitz, Tali; Schechner, Yoav Y

    2009-03-01

    Vision in scattering media is important but challenging. Images suffer from poor visibility due to backscattering and attenuation. Most prior methods for scene recovery use active illumination scanners (structured and gated), which can be slow and cumbersome, while natural illumination is inapplicable to dark environments. The current paper addresses the need for a non-scanning recovery method, that uses active scene irradiance. We study the formation of images under widefield artificial illumination. Based on the formation model, the paper presents an approach for recovering the object signal. It also yields rough information about the 3D scene structure. The approach can work with compact, simple hardware, having active widefield, polychromatic polarized illumination. The camera is fitted with a polarization analyzer. Two frames of the scene are taken, with different states of the analyzer or polarizer. A recovery algorithm follows the acquisition. It allows both the backscatter and the object reflection to be partially polarized. It thus unifies and generalizes prior polarization-based methods, which had assumed exclusive polarization of either of these components. The approach is limited to an effective range, due to image noise and illumination falloff. Thus, the limits and noise sensitivity are analyzed. We demonstrate the approach in underwater field experiments.

  17. Active quantum plasmonics.

    PubMed

    Marinica, Dana Codruta; Zapata, Mario; Nordlander, Peter; Kazansky, Andrey K; M Echenique, Pedro; Aizpurua, Javier; Borisov, Andrei G

    2015-12-01

    The ability of localized surface plasmons to squeeze light and engineer nanoscale electromagnetic fields through electron-photon coupling at dimensions below the wavelength has turned plasmonics into a driving tool in a variety of technological applications, targeting novel and more efficient optoelectronic processes. In this context, the development of active control of plasmon excitations is a major fundamental and practical challenge. We propose a mechanism for fast and active control of the optical response of metallic nanostructures based on exploiting quantum effects in subnanometric plasmonic gaps. By applying an external dc bias across a narrow gap, a substantial change in the tunneling conductance across the junction can be induced at optical frequencies, which modifies the plasmonic resonances of the system in a reversible manner. We demonstrate the feasibility of the concept using time-dependent density functional theory calculations. Thus, along with two-dimensional structures, metal nanoparticle plasmonics can benefit from the reversibility, fast response time, and versatility of an active control strategy based on applied bias. The proposed electrical manipulation of light using quantum plasmonics establishes a new platform for many practical applications in optoelectronics.

  18. THE ACTIVE ASTEROIDS

    SciTech Connect

    Jewitt, David

    2012-03-15

    Some asteroids eject dust, unexpectedly producing transient, comet-like comae and tails. First ascribed to the sublimation of near-surface water ice, mass-losing asteroids (also called 'main-belt comets') can in fact be driven by a surprising diversity of mechanisms. In this paper, we consider 11 dynamical asteroids losing mass, in nine of which the ejected material is spatially resolved. We address mechanisms for producing mass loss including rotational instability, impact ejection, electrostatic repulsion, radiation pressure sweeping, dehydration stresses, and thermal fracture, in addition to the sublimation of ice. In two objects (133P and 238P) the repetitive nature of the observed activity leaves ice sublimation as the only reasonable explanation, while in a third ((596) Scheila), a recent impact is the cause. Another impact may account for activity in P/2010 A2, but this tiny object can also be explained as having shed mass after reaching rotational instability. Mass loss from (3200) Phaethon is probably due to cracking or dehydration at extreme ({approx}1000 K) perihelion temperatures, perhaps aided by radiation pressure sweeping. For the other bodies, the mass-loss mechanisms remain unidentified, pending the acquisition of more and better data. While the active asteroid sample size remains small, the evidence for an astonishing diversity of mass-loss processes in these bodies is clear.

  19. Active quantum plasmonics

    PubMed Central

    Marinica, Dana Codruta; Zapata, Mario; Nordlander, Peter; Kazansky, Andrey K.; M. Echenique, Pedro; Aizpurua, Javier; Borisov, Andrei G.

    2015-01-01

    The ability of localized surface plasmons to squeeze light and engineer nanoscale electromagnetic fields through electron-photon coupling at dimensions below the wavelength has turned plasmonics into a driving tool in a variety of technological applications, targeting novel and more efficient optoelectronic processes. In this context, the development of active control of plasmon excitations is a major fundamental and practical challenge. We propose a mechanism for fast and active control of the optical response of metallic nanostructures based on exploiting quantum effects in subnanometric plasmonic gaps. By applying an external dc bias across a narrow gap, a substantial change in the tunneling conductance across the junction can be induced at optical frequencies, which modifies the plasmonic resonances of the system in a reversible manner. We demonstrate the feasibility of the concept using time-dependent density functional theory calculations. Thus, along with two-dimensional structures, metal nanoparticle plasmonics can benefit from the reversibility, fast response time, and versatility of an active control strategy based on applied bias. The proposed electrical manipulation of light using quantum plasmonics establishes a new platform for many practical applications in optoelectronics. PMID:26824066

  20. Sesterterpenoids with Anticancer Activity

    PubMed Central

    Evidente, Antonio; Kornienko, Alexander; Lefranc, Florence; Cimmino, Alessio; Dasari, Ramesh; Evidente, Marco; Mathieu, Véronique; Kiss, Robert

    2016-01-01

    Terpenes have received a great deal of attention in the scientific literature due to complex, synthetically challenging structures and diverse biological activities associated with this class of natural products. Based on the number of C5 isoprene units they are generated from, terpenes are classified as hemi- (C5), mono- (C10), sesqui- (C15), di- (C20), sester- (C25), tri (C30), and tetraterpenes (C40). Among these, sesterterpenes and their derivatives known as sesterterpenoids, are ubiquitous secondary metabolites in fungi, marine organisms, and plants. Their structural diversity encompasses carbotricyclic ophiobolanes, polycyclic anthracenones, polycyclic furan-2-ones, polycyclic hydroquinones, among many other carbon skeletons. Furthermore, many of them possess promising biological activities including cytotoxicity and the associated potential as anticancer agents. This review discusses the natural sources that produce sesterterpenoids, provides sesterterpenoid names and their chemical structures, biological properties with the focus on anticancer activities and literature references associated with these metabolites. A critical summary of the potential of various sesterterpenoids as anticancer agents concludes the review. PMID:26295461

  1. Transport to Rhebpress activity.

    PubMed

    Garrido, Amanda; Brandt, Marta; Djouder, Nabil

    2016-01-01

    The small GTPases from the rat sarcoma (Ras) superfamily are a heterogeneous group of proteins of about 21 kDa that act as molecular switches, modulating cell signaling pathways and controlling diverse cellular processes. They are active when bound to guanosine triphosphate (GTP) and inactive when bound to guanosine diphosphate (GDP). Ras homolog enriched in brain (Rheb) is a member of the Ras GTPase superfamily and a key activator of the mammalian/mechanistic target of rapamycin complex 1 (mTORC1). We recently determined that microspherule protein 1 (MCRS1) maintains Rheb at lysosomal surfaces in an amino acid-dependent manner. MCRS1 depletion promotes the formation of the GDP-bound form of Rheb, which is then delocalized from the lysosomal platform and transported to endocytic recycling vesicles, leading to mTORC1 inactivation. During this delocalization process, Rheb-GDP remains farnesylated and associated with cellular endomembranes. These findings provide new insights into the regulation of small GTPases, whose activity depends on both their GTP/GDP switch state and their capacity to move between different cellular membrane-bound compartments. Dynamic spatial transport between compartments makes it possible to alter the proximity of small GTPases to their activatory sites depending on the prevailing physiological and cellular conditions.

  2. Thermal activity on Enceladus

    NASA Astrophysics Data System (ADS)

    Tobie, G.; Besserer, J.; Behounkova, M.; Cadek, O.; Choblet, G.; Sotin, C.

    2009-04-01

    Observations by Cassini have revealed that Enceladus' souh pole is highly active, with jets of icy particles and water vapour emanated from narrow tectonic ridges, called "tiger stripes". This jet activity is associated to a very high thermal emission mainly focused along the tectonic ridges. Heat power required to sustain such an activity is probably related to the dissipation of mechanical energy due to tidal forces exerted by Saturn. However, the dissipation process and its relation to the tectonic features are not clearly established. Both shear heating along the tectonic ridges and viscous dissipation in the convective part of the ice shell could contribute to the energy budget (Nimmo et al. 2007, Tobie et al. 2008). Tobie et al. (2008) pointed out that only interior models with a liquid water layer at depth, covering at least ~2/3 of the southern hemisphere, can explain the observed magnitude of dissipation and its particular location at the south pole. However, the long term stability of such a liquid reservoir remains problematic (Roberts and Nimmo 2007) and the possible link between the liquid reservoir and the surface activities is unknown. Concentration of tidal stresses along the tiger ridges have also been invoked as a mechanism to trigger the eruptive processes (Hurtford et al. 2007, Smith-Konter et al. 2008). However, those models do not take into account a realistic rheological structure for the ice shell when computing the fluctuating stress field. Moreover, the effect of the faults on the background tidal stress is neglected. In particular, low viscosity values are expected to be associated with the shear zone along the tiger stripes and may have a significant impact of the global tidal stress field. In order to self-consistently determine the tidal deformation and its impact on the thermal activity on Enceladus, we are currently developing a 3D model that combines a thermal convection code in spherical geometry (Choblet et al. 2007) and a

  3. Gender Issues: An Activity File.

    ERIC Educational Resources Information Center

    Fountain, Susan

    This activity file grew out of research of an "Images of Women in Development" project of the Centre for Global Education at the University of York, England. The activities are intended for students in the 8- to 13-year-old range to learn more about gender issues. The activities are divided into four sections: (1) awareness-raising activities in…

  4. Metric Activities, Grades K-6.

    ERIC Educational Resources Information Center

    Draper, Bob, Comp.

    This pamphlet presents worksheets for use in fifteen activities or groups of activities designed for teaching the metric system to children in grades K through 6. The approach taken in several of the activities is one of conversion between metric and English units. The majority of the activities concern length, area, volume, and capacity. A…

  5. Changing Conceptions of Activation Energy.

    ERIC Educational Resources Information Center

    Pacey, Philip D.

    1981-01-01

    Provides background material which relates to the concept of activation energy, fundamental in the study of chemical kinetics. Compares the related concepts of the Arrhenius activation energy, the activation energy at absolute zero, the enthalpy of activation, and the threshold energy. (CS)

  6. Science Activities in Energy: Conservation.

    ERIC Educational Resources Information Center

    Oak Ridge Associated Universities, TN.

    Presented is a science activities in energy package which includes 14 activities relating to energy conservation. Activities are simple, concrete experiments for fourth, fifth and sixth grades, which illustrate principles and problems relating to energy. Each activity is outlined on a simple card which is introduced by a question. A teacher's…

  7. Epsiodic Activity in Radio Galaxies

    SciTech Connect

    Saikia, D.J.; Konar, C.; Jamrozy, M.; Machalski, J.; Gupta, Neeraj; Stawarz, L.; Mack, K.-H.; Siemiginowska, A.; /Harvard-Smithsonian Ctr. Astrophys.

    2007-10-15

    One of the interesting issues in our understanding of active galactic nuclei is the duration of their active phase and whether such activity is episodic. In this paper we summarize our recent results on episodic activity in radio galaxies obtained with the GMRT and the VLA.

  8. Antifertility effects of tetradecyl sodium sulphate in rabbits.

    PubMed

    Zimmerman, R E; Nevin, R S; Allen, D J; Jones, C D; Goettel, M E; Burck, P J

    1983-07-01

    Acrosin and acrosomal hyaluronidase were inhibited by tetradecyl sodium sulphate (TDSS) in vitro at concentrations of less than 10(-4) M. TDSS prevented the removal in vitro of the cumulus oophorus by testicular hyaluronidase and the zona pellucida by acrosin. TDSS had a contraceptive effect in rabbits when administered intravaginally before coitus or released at levels of 1-3 micrograms/day from intrauterine silicone rubber devices.

  9. Molecular and functional characterization of peptidoglycan-recognition protein SC2 (PGRP-SC2) from Nile tilapia (Oreochromis niloticus) involved in the immune response to Streptococcus agalactiae.

    PubMed

    Gan, Zhen; Chen, Shannan; Hou, Jing; Huo, Huijun; Zhang, Xiaolin; Ruan, Baiye; Laghari, Zubair Ahmed; Li, Li; Lu, Yishan; Nie, Pin

    2016-07-01

    PGRP-SC2, the member of PGRP family, plays an important role in regulation of innate immune response. In this paper, a PGRP-SC2 gene of Nile tilapia, Oreochromis niloticus (designated as On-PGRP-SC2) was cloned and its expression pattern under the infection of Streptococcus agalactiae was investigated. Sequence analysis showed main structural features required for amidase activity were detected in the deduced amino acid sequence of On-PGRP-SC2. In healthy tilapia, the On-PGRP-SC2 transcripts could be detected in all the examined tissues, with the most abundant expression in the muscle. When infected with S. agalactiae, there was a clear time-dependent expression pattern of On-PGRP-SC2 in the spleen, head kidney and brain. The assays for the amidase activity suggested that recombinant On-PGRP-SC2 protein had a Zn(2+)-dependent PGN-degrading activity. Moreover, our works showed that recombinant On-PGRP-SC2 protein could significantly reduce bacterial load in target organs attacked by S. agalactiae. These findings indicated that On-PGRP-SC2 may play important roles in the immune response to S. agalactiae in Nile tilapia.

  10. The active asteroids

    NASA Astrophysics Data System (ADS)

    Jewitt, D.

    2014-07-01

    Active asteroids simultaneously possess the orbits of main-belt asteroids and the physical appearances of comets; they show transient dust comae and solar-radiation pressure-swept tails. Apart from the shear surprise at finding such strange objects in the asteroid belt, the active asteroids are scientifically interesting for several reasons. Although we are limited to scarcely more than a dozen examples, the active asteroids already reveal the distinct action of different physical processes, each previously unobserved and carrying big-picture importance for understanding the solar system. 1. IMPACT. An unambiguous asteroid-asteroid impact was observed in 2010, when a 30-m scale body struck 100-km diameter (596) Scheila. Direct observations of impacts hold scientific importance both by sampling this natural process at full scale (compared with laboratory impacts conducted at tiny scales) and because impact statistics will allow us to assess the erosion rate in the asteroid belt and the contribution of asteroid dust to the interplanetary medium. 2. CRITICAL ROTATION. Several objects have been observed in which the best explanation seems to lie with spin-up to critical periods, presumably (but not certainly) caused by YORP. Examples of both likely mass-shedding (P/2010 A2, P/2013 P5) and full break-up (P/2013 R3, shown below) exist. It has been suggested that, at sub-kilometer sizes, spin-up disruption rates may surpass impact disruption rates. Future observations will show whether or not this is true, and may ultimately lead to an improved understanding of the physics of break-up. 3. THERMAL DISINTEGRATION. Geminid parent (3200) Phaethon shows on-going mass-loss at perihelion, driven by the 1000-K surface temperatures found there. The mechanisms appear to be some combination of thermal fracture and desiccation stress. 4. SUBLIMATION. Two objects have shown repeated activity that appears to be correlated with position in the orbit. The best example is 133P, which has

  11. Asthma and physical activity.

    PubMed

    Oseid, S

    1982-01-01

    Physical activity regularly leads to a decline in lung function in children and adolescents with asthma. This decline is a consequence of what is known as exercise-induced asthma (EIA), and can be determined and graded with the help of lung function tests before and after submaximal workloads on the ergometer cycle or the treadmill. Typical EIA appears in asthmatic individuals with entirely normal lung function before the effort, but EIA may also become clinically manifest with exercise in patients who have a subclinical degree of obstruction. The grade of EIA is essentially dependent on the duration and intensity of effort but also on the type of exercise. For example, free running causes much greater bronchoconstriction than swimming. The temperature and humidity of the inspired air may partially explain this difference. At the Voksentoppen Allergy Institute we find that about 85% of children develop a fall in lung function of 15% or more after a six minute ergometer cycle test. With typical EIA the fall may be totally or partially abolished by prophylactic medication 10 minutes before the start of the test. Disodium cromoglycate (Intal) and/or beta-adrenergic drugs are regularly used before all physical activity. Training programmes must be based on the interval principle. Swimming, ball games, relay races and dancing are examples of useful activities in the training and rehabilitation of children and adolescents with asthma. Through prophylactic medication and physical training, the aerobic work capacity, muscle strength and lung function in asthmatic children is improved. Training also leads to a significant mobilisation of mental resources and an increase in social integration.

  12. Active travel intervention and physical activity behaviour: an evaluation.

    PubMed

    Norwood, Patricia; Eberth, Barbara; Farrar, Shelley; Anable, Jillian; Ludbrook, Anne

    2014-07-01

    A physically active lifestyle is an important contributor to individual health and well-being. The evidence linking higher physical activity levels with better levels of morbidity and mortality is well understood. Despite this, physical inactivity remains a major global risk factor for mortality and, consequently, encouraging individuals to pursue physically active lifestyles has been an integral part of public health policy in many countries. Physical activity promotion and interventions are now firmly on national health policy agendas, including policies that promote active travel such as walking and cycling. This study evaluates one such active travel initiative, the Smarter Choices, Smarter Places programme in Scotland, intended to encourage uptake of walking, cycling and the use of public transport as more active forms of travel. House to house surveys were conducted before and after the programme intervention, in May/June 2009 and 2012 (12,411 surveys in 2009 and 9542 in 2012), for the evaluation of the programme. This paper analyses the physical activity data collected, focussing on what can be inferred from the initiative with regards to adult uptake of physical activity participation and whether, for those who participated in physical activity, the initiative impacted on meeting recommended physical activity guidelines. The results suggest that the initiative impacted positively on the likelihood of physical activity participation and meeting the recommended physical activity guidelines. Individuals in the intervention areas were on average 6% more likely to meet the physical activity guidelines compared to individuals in the non intervention areas. However, the absolute prevalence of physical activity participation declined in both intervention and control areas over time. Our evaluation of this active transport initiative indicates that similar programmes may aid in contributing to achieving physical activity targets and adds to the international

  13. Rationales for regulatory activity

    SciTech Connect

    Perhac, R.M.

    1997-02-01

    The author provides an outline which touches on the types of concerns about risk evaluation which are addressed in the process of establishing regulatory guides. Broadly he says regulatory activity serves three broad constituents: (1) Paternalism (private risk); (2) Promotion of social welfare (public risks); (3) Protection of individual rights (public risks). He then discusses some of the major issues encountered in reaching a decision on what is an acceptable level of risk within each of these areas, and how one establishes such a level.

  14. GPS Activities at SLAC

    SciTech Connect

    Behrend, Dirk

    2002-11-19

    The Alignment Engineering Group of the Stanford Linear Accelerator Center (SLAC) started to use RTK (real-time kinematic) GPS equipment in order to perform structure mapping and GIS-related tasks on the SLAC campus. In a first step a continuously observing GPS station (SLAC M40) was set up. This station serves as master control station for all differential GPS activities on site and its coordinates have been determined in the well-defined global geodetic datum ITRF2000 at a given reference epoch. Some trials have been performed to test the RTK method. The tests have proven RTK to be very fast and efficient.

  15. Reuse of activated alumina

    SciTech Connect

    Hobensack, J.E.

    1991-12-31

    Activated alumina is used as a trapping media to remove trace quantities of UF{sub 6} from process vent streams. The current uranium recovery method employs concentrated nitric acid which destroys the alumina pellets and forms a sludge which is a storage and disposal problem. A recently developed technique using a distilled water rinse followed by three dilute acid rinses removes on average 97% of the uranium, and leaves the pellets intact with crush strength and surface area values comparable with new material. Trapping tests confirm the effectiveness of the recycled alumina as UF{sub 6} trapping media.

  16. Crew Activity Analyzer

    NASA Technical Reports Server (NTRS)

    Murray, James; Kirillov, Alexander

    2008-01-01

    The crew activity analyzer (CAA) is a system of electronic hardware and software for automatically identifying patterns of group activity among crew members working together in an office, cockpit, workshop, laboratory, or other enclosed space. The CAA synchronously records multiple streams of data from digital video cameras, wireless microphones, and position sensors, then plays back and processes the data to identify activity patterns specified by human analysts. The processing greatly reduces the amount of time that the analysts must spend in examining large amounts of data, enabling the analysts to concentrate on subsets of data that represent activities of interest. The CAA has potential for use in a variety of governmental and commercial applications, including planning for crews for future long space flights, designing facilities wherein humans must work in proximity for long times, improving crew training and measuring crew performance in military settings, human-factors and safety assessment, development of team procedures, and behavioral and ethnographic research. The data-acquisition hardware of the CAA (see figure) includes two video cameras: an overhead one aimed upward at a paraboloidal mirror on the ceiling and one mounted on a wall aimed in a downward slant toward the crew area. As many as four wireless microphones can be worn by crew members. The audio signals received from the microphones are digitized, then compressed in preparation for storage. Approximate locations of as many as four crew members are measured by use of a Cricket indoor location system. [The Cricket indoor location system includes ultrasonic/radio beacon and listener units. A Cricket beacon (in this case, worn by a crew member) simultaneously transmits a pulse of ultrasound and a radio signal that contains identifying information. Each Cricket listener unit measures the difference between the times of reception of the ultrasound and radio signals from an identified beacon

  17. Minor meteor shower activity

    NASA Astrophysics Data System (ADS)

    Rendtel, J.

    2016-01-01

    Video meteor observations provide us with data to analyze structures in minor meteor showers or weak features in flux profiles. Samples obtained independently by other techniques allow to calibrate the data sets and to improve the confidence of results as demonstrated with a few results. Both, the confirmation of events predicted by model calculation and the input of observational data to improve the modelling results may help to better understand meteoroid stream evolution processes. Furthermore, calibrated data series can be used for studies of the long-term evolution of meteor shower activity.

  18. Enceladus: Starting Hydrothermal Activity

    NASA Technical Reports Server (NTRS)

    Matson, D. L.; Castillo-Rogez, J. C.; Johnson, T. V.; Lunine, J. I.; Davies, A. G.

    2011-01-01

    We describe a process for starting the hydrothermal activity in Enceladus' South Polar Region. The process takes advantage of fissures that reach the water table, about 1 kilometer below the surface. Filling these fissures with fresh ocean water initiates a flow of water up from an ocean that can be self-sustaining. In this hypothesis the heat to sustain the thermal anomalies and the plumes comes from a slightly warm ocean at depth. The heat is brought to the surface by water that circulates up, through the crust and then returns to the ocean.

  19. Active terahertz metamaterials

    SciTech Connect

    Chen, Hou-tong; O' Hara, John F; Taylor, Antoinette J

    2009-01-01

    In this paper we present an overview of research in our group in terahertz (THz) metamaterials and their applications. We have developed a series of planar metamaterials operating at THz frequencies, all of which exhibit a strong resonant response. By incorporating natural materials, e.g. semiconductors, as the substrates or as critical regions of metamaterial elements, we are able to effectively control the metamaterial resonance by the application of external stimuli, e.g., photoexcitation and electrical bias. Such actively controllable metamaterials provide novel functionalities for solid-state device applications with unprecedented performance, such as THz spectroscopy, imaging, and many others.

  20. Athena: Assessment Phase Activities

    NASA Astrophysics Data System (ADS)

    Lumb, David; Ayre, Mark

    2015-09-01

    The Athena mission concept has been proposed by the community in response to science themes of the Hot and Energetic Universe. Unlike other, competitive, mission selection exercises this "Large" class observatory mission has essentially been pre-selected. Nevertheless it has to be demonstrated that Athena meets the programmatic constraints of 1Bn euro cost cap, and a readiness level appropriate for formal mission adoption by the end 2019. This should be confirmed through a Phase A study conducted with two parallel industry activities. We describe the technical and programmatic content of these and latest progress in space and ground segment definition.

  1. Activation of solar flares

    SciTech Connect

    Cargill, P.J.; Migliuolo, S.; Hood, A.W.

    1984-11-01

    The physics of the activation of two-ribbon solar flares via the MHD instability of coronal arcades is presented. The destabilization of a preflare magnetic field is necessary for a rapid energy release, characteristic of the impulsive phase of the flare, to occur. The stability of a number of configurations are examined, and the physical consequences and relative importance of varying pressure profiles and different sets of boundary conditions (involving field-line tying) are discussed. Instability modes, driven unstable by pressure gradients, are candidates for instability. Shearless vs. sheared equilibria are also discussed. (ESA)

  2. ECLSS medical support activities

    NASA Technical Reports Server (NTRS)

    Crump, William J.; Kilgore, Melvin V., Jr.

    1991-01-01

    During the period from April 10, 1990 to April 9, 1991, the Consortium for the Space Life Sciences provided technical assistance to the NASA/MSFC water recovery efforts. This assistance was in the form of literature reviews, technical recommendations, and presentations. This final report summarizes the activities completed during this period and identifies those areas requiring additional efforts. The tasks which the University of Alabama in Huntsville (UAH) water recovery team addressed were either identified by MSFC technical representatives or chosen from those outlined in the subject statement of work.

  3. Bioethics activities in India.

    PubMed

    Kumar, Nandini K

    2006-01-01

    The Indian Council of Medical Research formulates, coordinates and promotes biomedical research in India. In 1980, they formulated the first national ethical guidelines. They offer a number of different training programmes, from 1 day to 6 months. The council is developing a core curriculum for teaching bioethics, which would be applied uniformly in medical schools throughout the country. Drug development and ethics is also important in India, particularly now that the local pharmaceutical industry is expanding and so many drugs trials are outsourced to the country. The council is also very active in encouraging the development of ethics review committees.

  4. AMS Prototyping Activities

    NASA Technical Reports Server (NTRS)

    Burleigh, Scott

    2008-01-01

    This slide presentation reviews the activity around the Asynchronous Message Service (AMS) prototype. An AMS reference implementation has been available since late 2005. It is aimed at supporting message exchange both in on-board environments and over space links. The implementation incoroporates all mandatory elements of the draft recommendation from July 2007: (1) MAMS, AMS, and RAMS protocols. (2) Failover, heartbeats, resync. (3) "Hooks" for security, but no cipher suites included in the distribution. The performance is reviewed, and a Benchmark latency test over VxWorks Message Queues is shown as histograms of a count vs microseconds per 1000-byte message

  5. Imaging nervous system activity.

    PubMed

    Fields, R D; O'Donovan, M J

    2001-05-01

    Optical imaging methods rely upon visualization of three types of signals: (1) intrinsic optical signals, including light scattering and reflectance, birefringence, and spectroscopic changes of intrinsic molecules, such as NADH or oxyhemoglobin; (2) changes in fluorescence or absorbance of voltage-sensitive membrane dyes; and (3) changes in fluorescence or absorbance of calcium-sensitive indicator dyes. Of these, the most widely used approach is fluorescent microscopy of calcium-sensitive dyes. This unit describes protocols for the use of calcium-sensitive dyes and voltage-dependent dyes for studies of neuronal activity in culture, tissue slices, and en-bloc preparations of the central nervous system.

  6. ASTP RBCC Activities

    NASA Technical Reports Server (NTRS)

    Nelson, Karl W.; McArthur, Craig; Leopard, Larry (Technical Monitor)

    2000-01-01

    This presentation reviews the activities of the Advanced Space Transportation Program (ASTP) in the development of Rocket-Based Combined Cycle (RBCC)technology. The document consist of the presentation slides for a talk scheduled to be given to the World Aviation Congress and Exhibit of SAE. Included in the review is discussion of recent accomplishments in the area of Advanced Reusable technologies (ART), which includes work in flowpath testing, and system studies of the various vehicle/engine combinations including RBCC, Turbine Based Combined Cycle (TBCC) and Pulsed Detonation Engine (PDE). Pictures of the proposed RBCC Flowpaths are included. The next steps in the development process are reviewed.

  7. Hypnotic activity of brotizolam

    PubMed Central

    Uzzan, B.; Warot, D.; Chermat, P.; Dantlo, B.; Bornstein, S.; Simon, P.

    1983-01-01

    1 A double-blind, crossover study was carried out in general practice on the hypnotic activity of 0.25 mg brotizolam in patients aged between 18 and 70 years complaining of insomnia (11 men, 28 women). 2 Patients reported that they slept better, that they awoke less frequently and that they slept longer with brotizolam than with placebo. Overall the patients preferred brotizolam to placebo, and subjective assessments of well-being after brotizolam did not differ from those after placebo. Brotizolam was well tolerated and there were no incidents of note. PMID:6362701

  8. Monitoring international nuclear activity

    SciTech Connect

    Firestone, R.B.

    2006-05-19

    The LBNL Table of Isotopes website provides primary nuclearinformation to>150,000 different users annually. We have developedthe covert technology to identify users by IP address and country todetermine the kinds of nuclear information they are retrieving. Wepropose to develop pattern recognition software to provide an earlywarning system to identify Unusual nuclear activity by country or regionSpecific nuclear/radioactive material interests We have monitored nuclearinformation for over two years and provide this information to the FBIand LLNL. Intelligence is gleaned from the website log files. Thisproposal would expand our reporting capabilities.

  9. Neutron activation analysis system

    DOEpatents

    Taylor, M.C.; Rhodes, J.R.

    1973-12-25

    A neutron activation analysis system for monitoring a generally fluid media, such as slurries, solutions, and fluidized powders, including two separate conduit loops for circulating fluid samples within the range of radiation sources and detectors is described. Associated with the first loop is a neutron source that emits s high flux of slow and thermal neutrons. The second loop employs a fast neutron source, the flux from which is substantially free of thermal neutrons. Adjacent to both loops are gamma counters for spectrographic determination of the fluid constituents. Other gsmma sources and detectors are arranged across a portion of each loop for deterMining the fluid density. (Official Gazette)

  10. Physical Activity in Elderly

    PubMed Central

    Tirpakova, Veronika; Sedliak, Milan; Kern, Helmut; Mayr, Winfried; Hamar, Dušan

    2015-01-01

    Aging is a multifactorial irreversible process associated with significant decline in muscle mass and neuromuscular functions. One of the most efficient methods to counteract age-related changes in muscle mass and function is physical exercise. An alternative effective intervention to improve muscle structure and performance is electrical stimulation. In the present work we present the positive effects of physical activity in elderly and a study where the effects of a 8-week period of functional electrical stimulation and strength training with proprioceptive stimulation in elderly are compared. PMID:26913164

  11. Activities for the classroom

    NASA Astrophysics Data System (ADS)

    Stark, Joyce

    From my research experiences on board the R/V Atlantis, I have developed experiments that can be used in an integrated science program or for biology. These activities reflect life in extreme environments on Earth such as the hydrothermal vents and on other planets and moons in our solar system. Students can learn to map the oceans of Europa and discover how plants grow on Mars. Students have designed research projects from the experimentation that I was involved with through the REVEL program.

  12. The Active Solid Earth

    NASA Astrophysics Data System (ADS)

    Ebinger, Cynthia

    2016-04-01

    Dynamic processes in Earth's crust, mantle and core shape Earth's surface and magnetic field over time scales of seconds to millennia, and even longer time scales as recorded in the ca. 4 Ga rock record. Our focus is the earthquake-volcano deformation cycles that occur over human time scales, and their comparison with time-averaged deformation studies, with emphasis on mantle plume provinces where magma and volatile release and vertical tectonics are readily detectable. Active deformation processes at continental and oceanic rift and back arc zones provide critical constraints on mantle dynamics, the role of fluids (volatiles, magma, water), and plate rheology. For example, recent studies of the East African rift zone, which formed above one of Earth's largest mantle upwellings reveal that magma production and volatile release rates are comparable to those of magmatic arcs, the archetypal zones of continental crustal creation. Finite-length faults achieve some plate deformation, but magma intrusion in the form of dikes accommodates extension in continental, back-arc, and oceanic rifts, and intrusion as sills causes permanent uplift that modulates the local time-space scales of earthquakes and volcanoes. Volatile release from magma intrusion may reduce fault friction and permeability, facilitating aseismic slip and creating magma pathways. We explore the implications of active deformation studies to models of the time-averaged structure of plume and extensional provinces in continental and oceanic plate settings.

  13. Raman activated cell sorting.

    PubMed

    Song, Yizhi; Yin, Huabing; Huang, Wei E

    2016-08-01

    Single cell Raman spectra (SCRS) are intrinsic biochemical profiles and 'chemical images' of single cells which can be used to characterise phenotypic changes, physiological states and functions of cells. On the base of SCRS, Raman activated cell sorting (RACS) provides a label-free cell sorting approach, which can link single cells to their chemical or phenotypic profiles. Overcoming naturally weak Raman signals, establishing Raman biomarker as sorting criteria to RACS and improving specific sorting technology are three challenges of developing RACS. Advances on Raman spectroscopy such as stimulated Raman scattering (SRS) and pre-screening helped to increase RACS sorting speed. Entire SCRS can be characterised using pattern recognition methods, and specific Raman bands can be extracted as biomarkers for RACS. Recent advances on cell sorting technologies based on microfluidic device and surface-ejection enable accurate and reliable single cell sorting from complex samples. A high throughput RACS will be achievable in near future by integrating fast Raman detection system such as SRS with microfluidic RACS and Raman activated cell ejection (RACE).

  14. Microbiologically active nanocomposite media

    NASA Astrophysics Data System (ADS)

    Petranovskii, Vitalii; Panina, Lyudmila; Bogomolova, Eugenia; Belostotskaya, Galina

    2003-07-01

    The most recent approach to the development of novel antimicrobial and antifungal agents is based on the application of synthetic and natural zeolites, because zeolites are known to be the carrier and slow releaser of the heavy metals with olygodynamic properties. The microbiological activity of the ion-exchanged zeolites is attributed to the ionic state of the metal sreleased from the zeolites by ion re-exchange. In the present work we used low cost natural clinoptilolite (Cli) as a substrate for copper and silver in different states. The state of oxidation of the exchanged metal in zeolite with supported Cu and Ag species (in the form of cations, small clusters, sub-coloidal particles, large particles) in order to fit them to fulfill the following criteria: to demonstrate their high protective abilities against fungi and long-term stability. The study of structure of samples with XRD, UV-visible spectroscopy, FTIR, their stability with temperature and during storage was carried out for obtaining the correct correlation with microbiological activity.

  15. Activating event knowledge.

    PubMed

    Hare, Mary; Jones, Michael; Thomson, Caroline; Kelly, Sarah; McRae, Ken

    2009-05-01

    An increasing number of results in sentence and discourse processing demonstrate that comprehension relies on rich pragmatic knowledge about real-world events, and that incoming words incrementally activate such knowledge. If so, then even outside of any larger context, nouns should activate knowledge of the generalized events that they denote or typically play a role in. We used short stimulus onset asynchrony priming to demonstrate that (1) event nouns prime people (sale-shopper) and objects (trip-luggage) commonly found at those events; (2) location nouns prime people/animals (hospital-doctor) and objects (barn-hay) commonly found at those locations; and (3) instrument nouns prime things on which those instruments are commonly used (key-door), but not the types of people who tend to use them (hose-gardener). The priming effects are not due to normative word association. On our account, facilitation results from event knowledge relating primes and targets. This has much in common with computational models like LSA or BEAGLE in which one word primes another if they frequently occur in similar contexts. LSA predicts priming for all six experiments, whereas BEAGLE correctly predicted that priming should not occur for the instrument-people relation but should occur for the other five. We conclude that event-based relations are encoded in semantic memory and computed as part of word meaning, and have a strong influence on language comprehension.

  16. Active Near Earth Asteroids

    NASA Astrophysics Data System (ADS)

    Jenniskens, Peter

    2015-08-01

    Past activity from Near Earth Asteroids is recorded in the meteoroid streams that cause our meteor showers. Automated meteoroid orbit surveys by photographic, low-light video, specular radar, and head-echo radar reflections are providing the first maps of meteor shower activity at different particle sizes. There are distinct differences in particle size distributions among streams. The underlaying mechanisms that created these streams are illuminated: fragmentation from spin-up or thermal stresses, meteoroid ejection by water vapor drag, and ejection of icy particles by CO and CO2 sublimation. The distribution of the meteoroid orbital elements probe the subsequent evolution by planetary perturbations and sample the range of dynamical processes to which Near Earth Asteroids are exposed. The non-stream "sporadic" meteors probe early stages in the evolution from meteoroid streams into the zodiacal dust cloud. We see that the lifetime of large meteoroids is generally not limited by collisions. Results obtained by the CAMS video survey of meteoroid orbits are compared to those from other orbit surveys. Since October 2010, over 200,000 meteoroid orbits have been measured. First results from an expansion into the southern hemisphere are also presented, as are first results from the measurement of main element compositions. Among the many streams detected so far, the Geminid and Sextantid showers stand out by having a relatively high particle density and derive from parent bodies that appear to have originated in the main belt.

  17. Visualizing cellulase activity.

    PubMed

    Bubner, Patricia; Plank, Harald; Nidetzky, Bernd

    2013-06-01

    Commercial exploitation of lignocellulose for biotechnological production of fuels and commodity chemicals requires efficient-usually enzymatic-saccharification of the highly recalcitrant insoluble substrate. A key characteristic of cellulose conversion is that the actual hydrolysis of the polysaccharide chains is intrinsically entangled with physical disruption of substrate morphology and structure. This "substrate deconstruction" by cellulase activity is a slow, yet markedly dynamic process that occurs at different length scales from and above the nanometer range. Little is currently known about the role of progressive substrate deconstruction on hydrolysis efficiency. Application of advanced visualization techniques to the characterization of enzymatic degradation of different celluloses has provided important new insights, at the requisite nano-scale resolution and down to the level of single enzyme molecules, into cellulase activity on the cellulose surface. Using true in situ imaging, dynamic features of enzyme action and substrate deconstruction were portrayed at different morphological levels of the cellulose, thus providing new suggestions and interpretations of rate-determining factors. Here, we review the milestones achieved through visualization, the methods which significantly promoted the field, compare suitable (model) substrates, and identify limiting factors, challenges and future tasks.

  18. [Sport and physical activity].

    PubMed

    Bria, S; Zeppilli, P

    2010-01-01

    A regular sport activity involves physical and psychological benefits helping to improve the quality of life at any age. This aspect is even more important in the developing age, when the sport takes on a role of training and education. In this context, instances directed to allow adolescent and young adults with heart disease to practice sports seem justified, and they're becoming more pressing since when the diagnostic and therapeutic advances, especially in cardiac surgery and in interventional hemodynamics, allow an increasing number of patients, previously allocated to physical inactivity, to lead an active lifestyle. However, we have to keep in mind that congenital heart disease population is varied, not only by the nature of the malformation, but also because in the same cardiopathy you can find subjects in "natural history" or after surgery and, between them, subjects treated with several techniques and different outcomes. This justifies the need for a close collaboration between sports doctors, cardiologists and heart surgeons, particularly in the management of the most difficult and delicate problems.

  19. Active Astronomy Roadshow Haiti

    NASA Astrophysics Data System (ADS)

    Laycock, Silas; Oram, Kathleen; Alabre, Dayana; Douyon, Ralph; UMass Lowell Haiti Development Studies Center

    2016-01-01

    College-age Haitian students working with advisors and volunteers from UMass Lowell in 2015 developed and tested an activity-based K-8 curriculum in astronomy, space, and earth science. Our partner school is located in Les Cayes, Haiti a city where only 65% of children attend school, and only half of those will complete 6th grade. Astronomy provides an accessible and non-intimidating entry into science, and activity-based learning contrasts with the predominant traditional teaching techniques in use in Haiti, to reach and inspire a different cohort of learners. Teachers are predominantly women in Haiti, so part of the effort involves connecting them with scientists, engineers and teacher peers in the US. As a developing nation, it is vital for Haitian (as for all) children to grow up viewing women as leaders in science. Meanwhile in the US, few are aware of the reality of getting an education in a 3rd world nation (i.e. most of the world), so we also joined with teachers in Massachusetts to give US school children a peek at what daily life is like for their peers living in our vibrant but impoverished neighbor. Our Haitian partners are committed to helping their sister-schools with curriculum and educator workshops, so that the overall quality of education can rise, and not be limited to the very few schools with access to resources. We will describe the activites, motivation, and and the lessons learned from our first year of the project.

  20. Neutron activation for ITER

    SciTech Connect

    Barnes, C.W.; Loughlin, M.J.; Nishitani, Takeo

    1996-04-29

    There are three primary goals for the Neutron Activation system for ITER: maintain a robust relative measure of fusion power with stability and high dynamic range (7 orders of magnitude); allow an absolute calibration of fusion power (energy); and provide a flexible and reliable system for materials testing. The nature of the activation technique is such that stability and high dynamic range can be intrinsic properties of the system. It has also been the technique that demonstrated (on JET and TFTR) the highest accuracy neutron measurements in DT operation. Since the gamma-ray detectors are not located on the tokamak and are therefore amenable to accurate characterization, and if material foils are placed very close to the ITER plasma with minimum scattering or attenuation, high overall accuracy in the fusion energy production (7--10%) should be achievable on ITER. In the paper, a conceptual design is presented. A system is shown to be capable of meeting these three goals, also detailed design issues remain to be solved.

  1. Tracking dynamic team activity

    SciTech Connect

    Tambe, M.

    1996-12-31

    AI researchers are striving to build complex multi-agent worlds with intended applications ranging from the RoboCup robotic soccer tournaments, to interactive virtual theatre, to large-scale real-world battlefield simulations. Agent tracking - monitoring other agent`s actions and inferring their higher-level goals and intentions - is a central requirement in such worlds. While previous work has mostly focused on tracking individual agents, this paper goes beyond by focusing on agent teams. Team tracking poses the challenge of tracking a team`s joint goals and plans. Dynamic, real-time environments add to the challenge, as ambiguities have to be resolved in real-time. The central hypothesis underlying the present work is that an explicit team-oriented perspective enables effective team tracking. This hypothesis is instantiated using the model tracing technology employed in tracking individual agents. Thus, to track team activities, team models are put to service. Team models are a concrete application of the joint intentions framework and enable an agent to track team activities, regardless of the agent`s being a collaborative participant or a non-participant in the team. To facilitate real-time ambiguity resolution with team models: (i) aspects of tracking are cast as constraint satisfaction problems to exploit constraint propagation techniques; and (ii) a cost minimality criterion is applied to constrain tracking search. Empirical results from two separate tasks in real-world, dynamic environments one collaborative and one competitive - are provided.

  2. Regulation of inflammasome activation.

    PubMed

    Man, Si Ming; Kanneganti, Thirumala-Devi

    2015-05-01

    Inflammasome biology is one of the most exciting and rapidly growing areas in immunology. Over the past 10 years, inflammasomes have been recognized for their roles in the host defense against invading pathogens and in the development of cancer, auto-inflammatory, metabolic, and neurodegenerative diseases. Assembly of an inflammasome complex requires cytosolic sensing of pathogen-associated molecular patterns or danger-associated molecular patterns by a nucleotide-binding domain and leucine-rich repeat receptor (NLR) or absent in melanoma 2 (AIM2)-like receptors (ALR). NLRs and ALRs engage caspase-1, in most cases requiring the adapter protein apoptosis-associated speck-like protein containing a CARD (ASC), to catalyze proteolytic cleavage of pro-interleukin-1β (pro-IL-1β) and pro-IL-18 and drive pyroptosis. Recent studies indicate that caspase-8, caspase-11, IL-1R-associated kinases (IRAK), and receptor-interacting protein (RIP) kinases contribute to inflammasome functions. In addition, post-translational modifications, including ubiquitination, deubiquitination, phosphorylation, and degradation control almost every aspect of inflammasome activities. Genetic studies indicate that mutations in NLRP1, NLRP3, NLRC4, and AIM2 are linked with the development of auto-inflammatory diseases, enterocolitis, and cancer. Overall, these findings transform our understanding of the basic biology and clinical relevance of inflammasomes. In this review, we provide an overview of the latest development of inflammasome research and discuss how inflammasome activities govern health and disease.

  3. Activities in dementia care: A comparative assessment of activity types.

    PubMed

    Lokon, Elizabeth; Sauer, Philip E; Li, Yue

    2016-12-05

    This exploratory study compares the impact of five activity types on the well-being of institutionalized people with dementia: the intergenerational art program Opening Minds through Art, art and music therapies, creative activities, non-creative activities, and no activities at all. We validated the Scripps Modified Greater Cincinnati Chapter Well-Being Observational Tool, and used that instrument to systematically observe N = 67 people with dementia as they participated in different activity types. People with dementia showed the highest well-being scores during Opening Minds through Art compared to all other activities. No significant well-being differences were found between creative activities led by licensed art/music therapist versus regular activity staff. Furthermore, no significant well-being differences were found between creative and non-creative activities that were both led by regular activity staff. Overall, people with dementia benefit from participating in activities, regardless of the type (creative or non-creative), or who conducts them (licensed therapists or activity staff). However, in order for people with dementia to reach significantly high levels of overall well-being, we recommend that activities are specifically designed for people with dementia and incorporate a 1:1 ratio between people with dementia and well-trained volunteers/staff members.

  4. The active video games' narrative impact on children's physical activities

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Active video games (AVGs) capable of inducing physical activity offer an innovative approach to combating childhood obesity. Unfortunately, children's AVG game play decreases quickly, underscoring the need to identify novel methods for player engagement. Narratives have been demonstrated to influenc...

  5. Active Magnetic Regenerative Liquefier

    SciTech Connect

    Barclay, John A.; Oseen-Send, Kathryn; Ferguson, Luke; Pouresfandiary, Jamshid; Cousins, Anand; Ralph, Heather; Hampto, Tom

    2016-01-12

    This final report for the DOE Project entitled Active Magnetic Regenerative Liquefier (AMRL) funded under Grant DE-FG36-08GO18064 to Heracles Energy Corporation d.b.a. Prometheus Energy (Heracles/Prometheus) describes an active magnetic regenerative refrigerator (AMRR) prototype designed and built during the period from July 2008 through May 2011. The primary goal of this project was to make significant technical advances toward highly efficient liquefaction of hydrogen. Conventional hydrogen liquefiers at any scale have a maximum FOM of ~0.35 due primarily to the intrinsic difficulty of rapid, efficient compression of either hydrogen or helium working gases. Numerical simulation modeling of high performance AMRL designs indicates certain designs have promise to increase thermodynamic efficiency from a FOM of ~0.35 toward ~0.5 to ~0.6. The technical approach was the use of solid magnetic working refrigerants cycled in and out of high magnetic fields to build an efficient active regenerative magnetic refrigeration module providing cooling power for AMRL. A single-stage reciprocating AMRR with a design temperature span from ~290 K to ~120 K was built and tested with dual magnetic regenerators moving in and out of the conductively-cooled superconducting magnet subsystem. The heat transfer fluid (helium) was coupled to the process stream (refrigeration/liquefaction load) via high performance heat exchangers. In order to maximize AMRR efficiency a helium bypass loop with adjustable flow was incorporated in the design because the thermal mass of magnetic refrigerants is higher in low magnetic field than in high magnetic field. Heracles/Prometheus designed experiments to measure AMRR performance under a variety of different operational parameters such as cycle frequency, magnetic field strength, heat transfer fluid flow rate, amount of bypass flow of the heat transfer fluid while measuring work input, temperature span, cooling capability as a function of cold temperature

  6. Overview of Langley activities in active controls research

    NASA Technical Reports Server (NTRS)

    Abel, I.; Newsom, J. R.

    1981-01-01

    The application of active controls technology to reduce aeroelastic response of aircraft structures offers a potential for significant payoffs in terms of aerodynamic efficiency and weight savings. The activities of the Langley Research Center (laRC) in advancing active controls technology. Activities are categorized into the development of appropriate analysis tools, control law synthesis methodology, and experimental investigations aimed at verifying both analysis and synthesis methodology.

  7. The potential of the acetonitrile biodegradation by Mesorhizobium sp. F28.

    PubMed

    Feng, Yun-Shu; Lee, Chi-Mei

    2009-05-30

    Mesorhizobium sp. F28 was used in the NHase/amidase enzyme system to convert acetonitrile into acetamide and acetic acid, and the cells grew with the production of acetic acid. The NHase activity of the strain F28 was 78 U mg(-1)dcw, observed in the conversion of 19.5mM acetonitrile at 0.2h. As the initial pH value was between 6.5 and 8.3, 18.3mM acetonitrile completely converted into acetamide within 2h and the accumulation of acetamide subsequently converted into acetic acid and ammonia within 46h. When 20.3mM acetamide was added in the medium, the conversion rate of acetonitrile was 80% at 2h and the conversion rate of the accumulative acetamide was slightly affected. The concentrations of acetic acid and ammonia were respectively 6.01 and 6.68 mM at 46h. The addition of acetic acid decreased the activities of the NHase and amidase. The conversion rate of acetonitrile was 94% at 9.5h and traces of acetic acid (0.25 mM) and ammonia (0.29 mM) were produced. The effects of product-inhibition indicated that the appropriate operation of bioreactor would be beneficial for Mesorizobium sp. F28 to degrade acetonitrile continuously.

  8. Youth Physical Activity Resource Use and Activity Measured by Accelerometry

    ERIC Educational Resources Information Center

    Maslow, Andra L.; Colabianchi, Natalie

    2011-01-01

    Objectives: To examine whether use of physical activity resources (e.g., parks) was associated with daily physical activity measured by accelerometry. Methods: One hundred eleven adolescents completed a travel diary with concurrent accelerometry. The main exposure was self-reported use of a physical activity resource (none /1 resources). The main…

  9. Examining Activism in Practice: A Qualitative Study of Archival Activism

    ERIC Educational Resources Information Center

    Novak, Joy Rainbow

    2013-01-01

    While archival literature has increasingly discussed activism in the context of archives, there has been little examination of the extent to which archivists in the field have accepted or incorporated archival activism into practice. Scholarship that has explored the practical application of archival activism has predominately focused on case…

  10. Activity Based Curriculum for Elementary Education. Additional Activities, K-6.

    ERIC Educational Resources Information Center

    Wichita Public Schools, KS.

    This elementary curriculum is a vehicle to provide manipulative activities that reinforce academic skills through meaningful, relevant, activity-based awareness of modern society. The twenty-six activity plans included in the curriculum place a major emphasis upon realistic or concrete experiences that deal with the manipulation and exploration of…

  11. Active Play: Exploring the Influences on Children's School Playground Activities

    ERIC Educational Resources Information Center

    Hyndman, Brendon; Benson, Amanda; Telford, Amanda

    2016-01-01

    Because children spend so much of their time in schools, their playgrounds offer a good setting for promoting active play in young lives. Teachers, instead of considering active play a taxing demand on their busy day, have begun to develop an informal curriculum for it. The authors review the research on children's active play and explores its…

  12. 101 Environmental Education Activities. Booklet 2--Language Art Activities.

    ERIC Educational Resources Information Center

    Whitney, Helen, Comp.

    This booklet containing 20 language arts activities is the second in the series "101 Environmental Education Activities" produced by the Upper Mississippi River ECO-Center. The description of each activity contains learning objectives, directions, and suggested student evaluation standards. Elementary and intermediate level students…

  13. 101 Environmental Education Activities. Booklet 4--Science Activities.

    ERIC Educational Resources Information Center

    Whitney, Helen, Comp.

    Fourth in the series "101 Environmental Education Activities" by the Upper Mississippi River ECO-Center, the booklet contains 39 environment-based science activities directed to students in primary, intermediate, and junior high classes. Organization of the activities usually includes grade level, objectives, procedures, and materials,…

  14. 101 Environmental Education Activities. Booklet 1--Art and Music Activities.

    ERIC Educational Resources Information Center

    Whitney, Helen, Comp.

    First of a series of 6 publications containing environmental education activities, this booklet by the Upper Mississippi River ECO-Center describes 12 environmentally-based art and music activities for elementary and intermediate grades. Each activity description contains objectives, preparation, materials, directions, student evaluation, and…

  15. Is enhanced physical activity possible using active videogames?

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Our research indicated that 10– to 12-year-old children receiving two active Wii (TM)(Nintendo (R); Nintendo of America, Inc., Redmond, WA) console videogames were no more physically active than children receiving two inactive videogames. Research is needed on how active videogames may increase phys...

  16. Summary of JPL Activities

    NASA Technical Reports Server (NTRS)

    Timmerman, Paul J.; Surampudi, Subbarao

    2000-01-01

    A viewgraph presentation outlines the Jet Propulsion Laboratory (JPL) flight programs, including past, present and future missions targeting Solar System exploration. Details, including launch dates and batteries used, are given for Deep Space 1 (Asteroid Rendezvous), Deep Space 2 (Mars Penetrator), Mars Global Surveyor, Mars Surveyor '98, Stardust, Europa Orbiter, Mars Surveyor 2001, Mars 2003 Lander and Rover, and Genesis (Solar Dust Return). Earth science projects are also outlined: Active Cavity Radiometer Irradiance Monitor (ARIMSAT), Ocean Topography Experiment (TOPEX/Poseidon), Jason-1 (TOPEX follow-on), and QuikScat/Seawinds (Ocean Winds Tracking). The status, background, and plans are given for several batteries: (1) 2.5 inch common pressure vessel (CPV), (2) 3.5 inch CPV, (3) Ni-H2, and (4) Li-Ion.

  17. P21 activated kinases

    PubMed Central

    Rane, Chetan K; Minden, Audrey

    2014-01-01

    The p21 activated kinases (Paks) are well known effector proteins for the Rho GTPases Cdc42 and Rac. The Paks contain 6 members, which fall into 2 families of proteins. The first family consists of Paks 1, 2, and 3, and the second consists of Paks 4, 5, and 6. While some of the Paks are ubiquitously expressed, others have more restrictive tissue specificity. All of them are found in the nervous system. Studies using cell culture, transgenic mice, and knockout mice, have revealed important roles for the Paks in cytoskeletal organization and in many aspects of cell growth and development. This review discusses the basic structures of the Paks, and their roles in cell growth, development, and in cancer. PMID:24658305

  18. Extravehicular activity welding experiment

    NASA Technical Reports Server (NTRS)

    Watson, J. Kevin

    1989-01-01

    The In-Space Technology Experiments Program (INSTEP) provides an opportunity to explore the many critical questions which can only be answered by experimentation in space. The objective of the Extravehicular Activity Welding Experiment definition project was to define the requirements for a spaceflight experiment to evaluate the feasibility of performing manual welding tasks during EVA. Consideration was given to experiment design, work station design, welding hardware design, payload integration requirements, and human factors (including safety). The results of this effort are presented. Included are the specific objectives of the flight test, details of the tasks which will generate the required data, and a description of the equipment which will be needed to support the tasks. Work station requirements are addressed as are human factors, STS integration procedures and, most importantly, safety considerations. A preliminary estimate of the cost and the schedule for completion of the experiment through flight and postflight analysis are given.

  19. Active Piezoelectric Diaphragms

    NASA Technical Reports Server (NTRS)

    Bryant, Robert G.; Effinger, Robert T., IV; Aranda, Isaiah, Jr.; Copeland, Ben M.; Covington, Ed W., III

    2002-01-01

    Several active piezoelectric diaphragms were fabricated by placing unelectroded piezoelectric disks between copper clad films patterned with Inter-Circulating Electrodes "ICE". When a voltage potential is applied to the electrodes, the result is radially distributed electric field that mechanically strains the piezo-ceramic along the Z-axis (perpendicular to the applied electric field), rather than the expected in-plane (XY-axis) direction. Unlike other out of plane piezoelectric actuators, which are benders, these Radial Field Diaphragms (RFDs) strain concentrically yet afford high displacements while maintaining a constant circumference. This paper covers the fabrication and characterization of these diaphragms as a function of poling field strength, ceramic diameter and line spacing, as well as the surface topography, the resulting strain field and displacement as a function of applied voltage ranging from DC to 10 Hz.

  20. Mechanically Activated Ion Channels

    PubMed Central

    Ranade, Sanjeev S.; Syeda, Ruhma; Patapoutian, Ardem

    2015-01-01

    Mechanotransduction, the conversion of physical forces into biochemical signals, is an essential component of numerous physiological processes including not only conscious senses of touch and hearing, but also unconscious senses such as blood pressure regulation. Mechanically activated (MA) ion channels have been proposed as sensors of physical force, but the identity of these channels and an understanding of how mechanical force is transduced has remained elusive. A number of recent studies on previously known ion channels along with the identification of novel MA ion channels have greatly transformed our understanding of touch and hearing in both vertebrates and invertebrates. Here, we present an updated review of eukaryotic ion channel families that have been implicated in mechanotransduction processes and evaluate the qualifications of the candidate genes according to specified criteria. We then discuss the proposed gating models for MA ion channels and highlight recent structural studies of mechanosensitive potassium channels. PMID:26402601

  1. DPAL activities in Japan

    NASA Astrophysics Data System (ADS)

    Endo, Masamori; Wani, Fumio

    2015-02-01

    Activities on diode pumped alkali laser (DPAL) in Japan is reviewed. We have started alkali laser works in 2011, and currently, we are the only players in Japan. Our interests are application oriented, and it is not only defense but also industrial. DPAL is a good candidate as a source of remote laser machining, thanks to its scalability and extremely good beam quality. We are studying on scientific and engineering problems of Cs DPAL with a small-scale apparatus. A commercial diode laser with volume Bragg grating outcoupler is used to pump the gain cell longitudinally. A 6.5 W continuous-wave output with optical to optical efficiency of 56% (based on the absorbed power) has been achieved. Numerical simulation codes are developed to understand the physics of DPAL and to help future developments.

  2. Active submarine volcano sampled

    USGS Publications Warehouse

    Taylor, B.

    1983-01-01

    On June 4, 1982, two full dredge hauls of fresh lava were recovered from the upper flanks of Kavachi submarine volcano, Solomon Islands, in the western Pacific Ocean, from the water depths of 1,200 and 2,700 feet. the shallower dredge site was within 0.5 mile of the active submarine vent shown at the surface by an area of slick water, probably caused by gas emissions. Kavachi is a composite stratovolcano that has been observed to erupt every year or two for at least the last 30 years (see photographs). An island formed in 1952, 1961, 1965, and 1978; but, in each case, it rapidly eroded below sea level. The latest eruption was observed by Solair pilots during the several weeks up to and including May 18, 1982. 

  3. Mechanically Activated Ion Channels.

    PubMed

    Ranade, Sanjeev S; Syeda, Ruhma; Patapoutian, Ardem

    2015-09-23

    Mechanotransduction, the conversion of physical forces into biochemical signals, is essential for various physiological processes such as the conscious sensations of touch and hearing, and the unconscious sensation of blood flow. Mechanically activated (MA) ion channels have been proposed as sensors of physical force, but the identity of these channels and an understanding of how mechanical force is transduced has remained elusive. A number of recent studies on previously known ion channels along with the identification of novel MA ion channels have greatly transformed our understanding of touch and hearing in both vertebrates and invertebrates. Here, we present an updated review of eukaryotic ion channel families that have been implicated in mechanotransduction processes and evaluate the qualifications of the candidate genes according to specified criteria. We then discuss the proposed gating models for MA ion channels and highlight recent structural studies of mechanosensitive potassium channels.

  4. Monitoring active volcanoes

    USGS Publications Warehouse

    Tilling, Robert I.

    1987-01-01

    One of the most spectacular, awesomely beautiful, and at times destructive displays of natural energy is an erupting volcano, belching fume and ash thousands of meters into the atmosphere and pouring out red-hot molten lava in fountains and streams. Countless eruptions in the geologic past have produced volcanic rocks that form much of the Earth's present surface. The gradual disintegration and weathering of these rocks have yielded some of the richest farmlands in the world, and these fertile soils play a significant role in sustaining our large and growing population. Were it not for volcanic activity, the Hawaiian Islands with their sugar cane and pineapple fields and magnificent landscapes and seascapes would not exist to support their residents and to charm their visitors. Yet, the actual eruptive processes are catastrophic and can claim life and property.

  5. CNES gondola development activities

    NASA Astrophysics Data System (ADS)

    Vargas, André; Verdier, Nicolas; Escarnot, Jean-Pierre; Vargas, André

    Recent safety rules and gondola obsolescence oblige CNES to initiate new developments to improve performances according scientific needs. A large project called NOSYCA will able to offer versatile housekeeping and science telemetry system for Zero Pressure Balloons. This concept is modular, use IP protocol for scientific high data rate and mix telemetry systems to perform long duration flight. To respect safety duties, the long duration flight ISBA gondola is modified. New functions are implemented to increase reliability for stratospheric super and zero Pressure balloons flights. "Pointed gondola activity" is also concerned by improvements. After the First Fireball flight, new equipment designs are in progress for future missions. At least, boundary layer balloons performances of science payload and housekeeping system increase with new instrumentation and network telemetry concepts.

  6. Factors regulating microglia activation

    PubMed Central

    Kierdorf, Katrin; Prinz, Marco

    2013-01-01

    Microglia are resident macrophages of the central nervous system (CNS) that display high functional similarities to other tissue macrophages. However, it is especially important to create and maintain an intact tissue homeostasis to support the neuronal cells, which are very sensitive even to minor changes in their environment. The transition from the “resting” but surveying microglial phenotype to an activated stage is tightly regulated by several intrinsic (e.g., Runx-1, Irf8, and Pu.1) and extrinsic factors (e.g., CD200, CX3CR1, and TREM2). Under physiological conditions, minor changes of those factors are sufficient to cause fatal dysregulation of microglial cell homeostasis and result in severe CNS pathologies. In this review, we discuss recent achievements that gave new insights into mechanisms that ensure microglia quiescence. PMID:23630462

  7. Implementation team activities

    NASA Astrophysics Data System (ADS)

    Linder, F.

    2002-12-01

    The implementation Team (IT) is a body reporting to the SCSB,. It has been assigned the task of preparing and harmonising policy, standards and specification proposals for evaluation, qualification and quality control, thus enabling a coherent and cost-effective ESCC Specification System for the procurement of EEE space components. Among the 10 recommendations issued by the SCAHC, 7 have been studied under the auspices of the Implementation Team. Its main activities have been the updating and modernising of the ESA/SCC system in order to meet user needs and to be compatible with market trends. In particular it updated the technical aspects of generic specifications for the different component families and introduced the QML concept into the SCC system. It has also studied and discussed other topics such as procurement standards, a reliability system, mutual recognition, databases and the preferred parts list. A summary of the progress made in all these fields will be presented below.

  8. Actively stressed marginal networks.

    PubMed

    Sheinman, M; Broedersz, C P; MacKintosh, F C

    2012-12-07

    We study the effects of motor-generated stresses in disordered three-dimensional fiber networks using a combination of a mean-field theory, scaling analysis, and a computational model. We find that motor activity controls the elasticity in an anomalous fashion close to the point of marginal stability by coupling to critical network fluctuations. We also show that motor stresses can stabilize initially floppy networks, extending the range of critical behavior to a broad regime of network connectivities below the marginal point. Away from this regime, or at high stress, motors give rise to a linear increase in stiffness with stress. Finally, we demonstrate that our results are captured by a simple, constitutive scaling relation highlighting the important role of nonaffine strain fluctuations as a susceptibility to motor stress.

  9. Lightning activity on Jupiter

    NASA Technical Reports Server (NTRS)

    Borucki, W. J.; Bar-Nun, A.; Scarf, F. L.; Look, A. F.; Hunt, G. E.

    1982-01-01

    Photographic observations of the nightside of Jupiter by the Voyager 1 spacecraft show the presence of extensive lightning activity. Detection of whistlers by the plasma wave analyzer confirms the optical observations and implies that many flashes were not recorded by the Voyager camera because the intensity of the flashes was below the threshold sensitivity of the camera. Measurements of the optical energy radiated per flash indicate that the observed flashes had energies similar to that for terrestrial superbolts. The best estimate of the lightning energy dissipation rate of 0.0004 W/sq m was derived from a consideration of the optical and radiofrequency measurements. The ratio of the energy dissipated by lightning compared to the convective energy flux is estimated to be between 0.000027 and 0.00005. The terrestrial value is 0.0001.

  10. Small Active Radiation Monitor

    NASA Technical Reports Server (NTRS)

    Badhwar, Gautam D.

    2004-01-01

    A device, named small active radiation monitor, allows on-orbit evaluations during periods of increased radiation, after extravehicular activities, or at predesignated times for crews on such long-duration space missions as on the International Space Station. It also permits direct evaluation of biological doses, a task now performed using a combination of measurements and potentially inaccurate simulations. Indeed the new monitor can measure a full array of radiation levels, from soft x-rays to hard galactic cosmic-ray particles. With refinement, it will benefit commercial (nuclear power-plant workers, airline pilots, medical technicians, physicians/dentists, and others) and military personnel as well as the astronauts for whom thermoluminescent dosimeters are inadequate. Civilian and military personnel have long since graduated from film badges to thermoluminescent dosimeters. Once used, most dosimeters must be returned to a central facility for processing, a step that can take days or even weeks. While this suffices for radiation workers for whom exposure levels are typically very low and of brief duration, it does not work for astronauts. Even in emergencies and using express mail, the results can often be delayed by as much as 24 hours. Electronic dosimeters, which are the size of electronic oral thermometers, and tattlers, small electronic dosimeters that sound an alarm when the dose/dose rate exceeds preset values, are also used but suffer disadvantages similar to those of thermoluminescent dosimeters. None of these devices fully answers the need of rapid monitoring during the space missions. Instead, radiation is monitored by passive detectors, which are read out after the missions. Unfortunately, these detectors measure only the absorbed dose and not the biologically relevant dose equivalent. The new monitor provides a real-time readout, a time history of radiation exposures (both absorbed dose and biologically relevant dose equivalent), and a count of the

  11. Earthquake activity in Oklahoma

    SciTech Connect

    Luza, K.V.; Lawson, J.E. Jr. )

    1989-08-01

    Oklahoma is one of the most seismically active areas in the southern Mid-Continent. From 1897 to 1988, over 700 earthquakes are known to have occurred in Oklahoma. The earliest documented Oklahoma earthquake took place on December 2, 1897, near Jefferson, in Grant County. The largest known Oklahoma earthquake happened near El Reno on April 9, 1952. This magnitude 5.5 (mb) earthquake was felt from Austin, Texas, to Des Moines, Iowa, and covered a felt area of approximately 362,000 km{sup 2}. Prior to 1962, all earthquakes in Oklahoma (59) were either known from historical accounts or from seismograph stations outside the state. Over half of these events were located in Canadian County. In late 1961, the first seismographs were installed in Oklahoma. From 1962 through 1976, 70 additional earthquakes were added to the earthquake database. In 1977, a statewide network of seven semipermanent and three radio-telemetry seismograph stations were installed. The additional stations have improved earthquake detection and location in the state of Oklahoma. From 1977 to 1988, over 570 additional earthquakes were located in Oklahoma, mostly of magnitudes less than 2.5. Most of these events occurred on the eastern margin of the Anadarko basin along a zone 135 km long by 40 km wide that extends from Canadian County to the southern edge of Garvin County. Another general area of earthquake activity lies along and north of the Ouachita Mountains in the Arkoma basin. A few earthquakes have occurred in the shelves that border the Arkoma and Anadarko basins.

  12. Science Activities for School Trips.

    ERIC Educational Resources Information Center

    Quint, Walter C.

    1980-01-01

    Describes ways in which physics-learning activity packets can be used by high school students participating in trips organized by other departments. Provides an example of physics activities incorporated into an airplane trip to Disney World. (CS)

  13. Antinociceptive activity of Helicteres isora.

    PubMed

    Venkatesh, Sama; Laxmi, K Sai; Reddy, B Madhava; Ramesh, M

    2007-02-01

    Helicteres isora root extracts were studied for antinociceptive activity on acetic acid-induced writhing test in mice, at a dose of 250 mg/kg. Petroleum ether, chloroform and aqueous ethanol extracts have shown significant activity.

  14. Physical Activity and Your Heart

    MedlinePlus

    ... more energy than resting. Walking, running, dancing, swimming, yoga, and gardening are a few examples of physical activity. According to the Department of Health and Human Services' 2008 Physical Activity Guidelines for ...

  15. Environmental Education Tips: Weather Activities.

    ERIC Educational Resources Information Center

    Brainard, Audrey H.

    1989-01-01

    Provides weather activities including questions, on weather, heating the earth's surface, air, tools of the meteorologist, clouds, humidity, wind, and evaporation. Shows an example of a weather chart activity. (RT)

  16. Physical activity extends life expectancy

    Cancer.gov

    Leisure-time physical activity is associated with longer life expectancy, even at relatively low levels of activity and regardless of body weight, according to a study by a team of researchers led by the NCI.

  17. Antiviral activities of photoactive perylenequinones.

    PubMed

    Hudson, J B; Imperial, V; Haugland, R P; Diwu, Z

    1997-02-01

    Nine perylenequinones (PQ), including some familiar naturally occurring pigments, were compared for their light-mediated antiviral efficacies. Calphostin C was the most active compound against the two target viruses, herpes simplex virus type 1 and Sindbis virus. Hypocrellins A and B were also very active. However, three cercosporin-like PQ were substantially less active in spite of their high quantum yields of singlet oxygen, whereas phleichrome, another efficient singlet oxygen producer, showed no detectable antiviral activity. One other PQ, which was a very weak singlet oxygen producer, also showed no antiviral activity. None of the active compounds showed significant antiviral activity in the dark. Thus, for some groups of PQ there was correlation between quantum yield of singlet oxygen (1O2) and antiviral efficacy, but there are evidently other structural features of PQ that influence activity.

  18. Papermaking as a Science Activity.

    ERIC Educational Resources Information Center

    Fetters, Marcia K.

    2000-01-01

    Describes a simple procedure for making paper and provides some suggestions for extending and modifying the activity. The activity is correlated to the National Science Standards and Benchmarks for Science Literacy. (SAH)

  19. Diabetes Diet, Eating, & Physical Activity

    MedlinePlus

    ... Disease, & Other Dental Problems Diabetes & Sexual & Urologic Problems Diabetes Diet, Eating, & Physical Activity Nutrition and physical activity ... What foods can I eat if I have diabetes? You may worry that having diabetes means going ...

  20. The Study of Animal Activity

    ERIC Educational Resources Information Center

    Westling, Bruce

    1971-01-01

    Describes how to measure the daily rhythm of activity (photoperiodism) of small mammals. Three methods for recording information are reviewed including instructions for making a recorder. Includes suggestions for activities and experiments. (PR)

  1. Organic active materials for batteries

    SciTech Connect

    Abouimrane, Ali; Weng, Wei; Amine, Khalil

    2016-08-16

    A rechargeable battery includes a compound having at least two active sites, R.sup.1 and R.sup.2; wherein the at least two active sites are interconnected by one or more conjugated moieties; each active site is coordinated to one or more metal ions M.sup.a+ or each active site is configured to coordinate to one or more metal ions; and "a" is 1, 2, or 3.

  2. Insight into hydroxides-activated coals: chemical or physical activation?

    SciTech Connect

    Alcaniz-Monge, J.; Illan-Gomez, M.J.

    2008-02-15

    The objective of this paper is to get an insight into the chemical activation mechanism using KOH and NaOH as activated agents. Three coals have been selected as carbon precursors. It was found that KOH and NaOH develop a similar narrow microporosity, independently of the coal rank, whereas only KOH generates supermicroporosity. Temperature-programmed desorption experiments, carried out with impregnated anthracite, show differences on the gas evolved during the activated carbon preparation using the two activating agents. Thus, whereas hydrogen profiles are quite similar for both activated agents, the CO and H{sub 2}O profiles are different. It is remarkable the high amount of H{sub 2}O evolved at the maximum treatment temperature for both activating agents. The results obtained to allow conclusion that the chemical activation is due to a combination of different process driving the development of material porosity.

  3. Assessing and Increasing Physical Activity

    ERIC Educational Resources Information Center

    Van Camp, Carole M.; Hayes, Lynda B.

    2012-01-01

    Increasing physical activity is a crucial component of any comprehensive approach to combat the growing obesity epidemic. This review summarizes recent behavioral research on the measurement of physical activity and interventions aimed at increasing physical activity and provides directions for future research.

  4. Encapsulation of new active ingredients

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The organic construct consumed as food comes packaged in units that carry the active components, protects the entrapped active materials until delivered to targeted human organ. The packaging and delivery role is mimicked in the microencapsulation tools used to deliver active ingredients in process...

  5. Art Activities for the Handicapped.

    ERIC Educational Resources Information Center

    Laurie, Frank, Comp.

    Intended for professionals interested in incorporating arts activities into the educational programs for disabled students, Part One of the document contains arts activities contributed by clinician-presenters in the 1978 Illinois series of Very Special Arts Festivals; while Part Two contains activities contributed by clinician-presenters and…

  6. Hospitality Services. Student Activity Book.

    ERIC Educational Resources Information Center

    Texas Tech Univ., Lubbock. Home Economics Curriculum Center.

    This student activity book contains pencil-and-paper activities for use in a hospitality services course focusing on the food and lodging segments of the hospitality and tourism industry. The activities are organized into 29 chapters on the following topics: hospitality services industry; professional ethics; organization/management structures in…

  7. Activation Cascading in Sign Production

    ERIC Educational Resources Information Center

    Navarrete, Eduardo; Peressotti, Francesca; Lerose, Luigi; Miozzo, Michele

    2017-01-01

    In this study, we investigated how activation unfolds in sign production by examining whether signs that are not produced have their representations activated by semantics (cascading of activation). Deaf signers were tested with a picture-picture interference task. Participants were presented with pairs of overlapping pictures and named the green…

  8. RELAXIN ACTIVATES PEROXISOME PROLIFERATOR-ACTIVATED RECEPTOR GAMMA

    PubMed Central

    Singh, Sudhir; Bennett, Robert G

    2009-01-01

    SUMMARY Relaxin is a polypeptide hormone that triggers multiple signaling pathways through its receptor RXFP1. Many of relaxin’s functions, including vascular and antifibrotic effects, are similar to those induced by activation of PPARγ. In this study, we tested the hypothesis that relaxin signaling through RXFP1 would activate PPARγ activity. In cells overexpressing RXFP1 (HEK-RXFP1), relaxin increased transcriptional activity through a PPAR response element (PPRE) in a concentration-dependent manner. In cells lacking RXFP1, relaxin had no effect. Relaxin increased both the baseline activity and the response to the PPARγ agonists rosiglitazone and 15d-PGJ2, but not to agonists of PPARα or PPARδ. In HEK-RXFP1 cells infected with adenovirus expressing PPARγ, relaxin increased transcriptional activity through PPRE, and this effect was blocked with an adenovirus expressing a dominant-negative PPARγ. Knockdown of PPARγ using siRNA resulted in a decrease in the response to both relaxin and rosiglitazone. Both relaxin and rosiglitazone increased expression of the PPARγ target genes CD36 and LXRα in HEK-RXFP1 and in THP-1 cells naturally expressing RXFP1. Relaxin did not increase PPARγ mRNA or protein levels. Treatment of cells with GW9662, an inhibitor of PPARγ ligand binding, effectively blocked rosiglitazone-induced PPARγ activation, but had no effect on relaxin activation of PPARγ. These results suggest that relaxin activates PPARγ activity, and increases the overall response in the presence PPARγ agonists. This activation is dependent on the presence of RXFP1. Furthermore, relaxin activates PPARγ via a ligand-independent mechanism. These studies represent the first report that relaxin can activate the transcriptional activity of PPARγ. PMID:19712722

  9. Oriented active shape models.

    PubMed

    Liu, Jiamin; Udupa, Jayaram K

    2009-04-01

    Active shape models (ASM) are widely employed for recognizing anatomic structures and for delineating them in medical images. In this paper, a novel strategy called oriented active shape models (OASM) is presented in an attempt to overcome the following five limitations of ASM: 1) lower delineation accuracy, 2) the requirement of a large number of landmarks, 3) sensitivity to search range, 4) sensitivity to initialization, and 5) inability to fully exploit the specific information present in the given image to be segmented. OASM effectively combines the rich statistical shape information embodied in ASM with the boundary orientedness property and the globally optimal delineation capability of the live wire methodology of boundary segmentation. The latter characteristics allow live wire to effectively separate an object boundary from other nonobject boundaries with similar properties especially when they come very close in the image domain. The approach leads to a two-level dynamic programming method, wherein the first level corresponds to boundary recognition and the second level corresponds to boundary delineation, and to an effective automatic initialization method. The method outputs a globally optimal boundary that agrees with the shape model if the recognition step is successful in bringing the model close to the boundary in the image. Extensive evaluation experiments have been conducted by utilizing 40 image (magnetic resonance and computed tomography) data sets in each of five different application areas for segmenting breast, liver, bones of the foot, and cervical vertebrae of the spine. Comparisons are made between OASM and ASM based on precision, accuracy, and efficiency of segmentation. Accuracy is assessed using both region-based false positive and false negative measures and boundary-based distance measures. The results indicate the following: 1) The accuracy of segmentation via OASM is considerably better than that of ASM; 2) The number of landmarks

  10. Distributed Active Archive Center

    NASA Technical Reports Server (NTRS)

    Bodden, Lee; Pease, Phil; Bedet, Jean-Jacques; Rosen, Wayne

    1993-01-01

    The Goddard Space Flight Center Version 0 Distributed Active Archive Center (GSFC V0 DAAC) is being developed to enhance and improve scientific research and productivity by consolidating access to remote sensor earth science data in the pre-EOS time frame. In cooperation with scientists from the science labs at GSFC, other NASA facilities, universities, and other government agencies, the DAAC will support data acquisition, validation, archive and distribution. The DAAC is being developed in response to EOSDIS Project Functional Requirements as well as from requirements originating from individual science projects such as SeaWiFS, Meteor3/TOMS2, AVHRR Pathfinder, TOVS Pathfinder, and UARS. The GSFC V0 DAAC has begun operational support for the AVHRR Pathfinder (as of April, 1993), TOVS Pathfinder (as of July, 1993) and the UARS (September, 1993) Projects, and is preparing to provide operational support for SeaWiFS (August, 1994) data. The GSFC V0 DAAC has also incorporated the existing data, services, and functionality of the DAAC/Climate, DAAC/Land, and the Coastal Zone Color Scanner (CZCS) Systems.

  11. Photoperiodism and Enzyme Activity

    PubMed Central

    Queiroz, Orlando; Morel, Claudine

    1974-01-01

    Metabolic readjustments after a change from long days to short days appear, in Kalanchoe blossfeldiana, to be achieved through the operation of two main mechanisms: variation in enzyme capacity, and circadian rhythmicity. After a lag time, capacity in phosphoenolpyruvate carboxylase and capacity in aspartate aminotransferase increase exponentially and appear to be allometrically linked during 50 to 60 short days; then a sudden fall takes place in the activity of the former. Malic enzyme and alanine aminotransferase behave differently. Thus, the operation of the two sections of the pathway (before and after the malate step) give rise to a continuously changing functional compartmentation in the pathway. Circadian rhythmicity, on the other hand, produces time compartmentation through phase shifts and variation in amplitude, independently for each enzyme. These characteristics suggest that the operation of a so-called biological clock would be involved. We propose the hypothesis that feedback regulation would be more accurate and efficient when applied to an already oscillating, clock-controlled enzyme system. PMID:16658749

  12. Optically active quantum dots

    NASA Astrophysics Data System (ADS)

    Gerard, Valerie; Govan, Joseph; Loudon, Alexander; Baranov, Alexander V.; Fedorov, Anatoly V.; Gun'ko, Yurii K.

    2015-10-01

    The main goal of our research is to develop new types of technologically important optically active quantum dot (QD) based materials, study their properties and explore their biological applications. For the first time chiral II-VI QDs have been prepared by us using microwave induced heating with the racemic (Rac), D- and L-enantiomeric forms of penicillamine as stabilisers. Circular dichroism (CD) studies of these QDs have shown that D- and L-penicillamine stabilised particles produced mirror image CD spectra, while the particles prepared with a Rac mixture showed only a weak signal. It was also demonstrated that these QDs show very broad emission bands between 400 and 700 nm due to defects or trap states on the surfaces of the nanocrystals. These QDs have demonstrated highly specific chiral recognition of various biological species including aminoacids. The utilisation of chiral stabilisers also allowed the preparation of new water soluble white emitting CdS nano-tetrapods, which demonstrated circular dichroism in the band-edge region of the spectrum. Biological testing of chiral CdS nanotetrapods displayed a chiral bias for an uptake of the D- penicillamine stabilised nano-tetrapods by cancer cells. It is expected that this research will open new horizons in the chemistry of chiral nanomaterials and their application in nanobiotechnology, medicine and optical chemo- and bio-sensing.

  13. VERA Geodetic Activities

    NASA Technical Reports Server (NTRS)

    Jike, Takaaki; Tamura, Yoshiaki; Shizugami, Makoto

    2013-01-01

    This report briefly describes the geodetic activities of VERA in the year 2012. The regular geodetic observations are carried out both in K- and S/X-bands. The frequency of regular observations is three times a month-twice for the VERA internal observations in K-band. The networks of the S/X sessions are JADE of GSI and IVS-T2. The raw data of the T2 and JADE sessions are electronically transferred to the Bonn, Haystack, and GSI correlators via Internet. Gravimetric observations are carried out at the VERA stations. An SG was installed at Mizusawa and placed in the vicinity of the VERA antenna in order to monitor vertical displacement at the end of 2008, and the observations continued throughout the year. Also at the VERA-Ishigakijima station, continuous operation of the SG started in 2012. The crustal movements generated by the 2011 earthquake off the Pacific coast of Tohoku continued during 2012, and displacement of the VERA-Mizusawa position by post-seismic creeping continued.

  14. Active control of convection

    NASA Astrophysics Data System (ADS)

    Singer, Jonathan; Bau, Haim H.

    1991-12-01

    It is demonstrated theoretically that active (feedback) control can be used to alter the characteristics of thermal convection in a toroidal, vertical loop heated from below and cooled from above. As the temperature difference between the heated and cooled sections of the loop increases, the flow in the uncontrolled loop changes from no motion to steady, time-independent motion to temporally oscillatory, chaotic motion. With the use of a feedback controller effecting small perturbations in the boundary conditions, one can maintain the no-motion state at significantly higher temperature differences than the critical one corresponding to the onset of convection in the uncontrolled system. Alternatively, one can maintain steady, time-independent flow under conditions in which the flow would otherwise be chaotic. That is, the controller can be used to suppress chaos. Likewise, it is possible to stabilize periodic nonstable orbits that exist in the chaotic regime of the uncontrolled system. Finally, the controller also can be used to induce chaos in otherwise laminar (fully predictable), nonchaotic flow.

  15. ADASY (Active Daylighting System)

    NASA Astrophysics Data System (ADS)

    Vázquez-Moliní, Daniel; González-Montes, Mario; Fernández-Balbuena, Antonio Á.; Bernabéu, Eusebio; García-Botella, Ángel; García-Rodríguez, Lucas; Pohl, Wilfried

    2009-08-01

    The main objective of ADASY (Active Daylighting System) work is to design a façade static daylighting system oriented to office applications, mainly. The goal of the project is to save energy by guiding daylight into a building for lighting purpose. With this approach we can reduce the electrical load for artificial lighting, completing it with sustainable energy. The collector of the system is integrated on a vertical façade and its distribution guide is always horizontal inside of the false ceiling. ADASY is designed with a specific patent pending caption system, a modular light-guide and light extractor luminaire system. Special care has been put on the final cost of the system and its building integration purpose. The current ADASY configuration is able to illuminate 40 m2 area with a 300lx-400lx level in the mid time work hours; furthermore it has a good enough spatial uniformity distribution and a controlled glare. The data presented in this study are the result of simulation models and have been confirmed by a physical scaled prototype. ADASY's main advantages over regular illumination systems are: -Low maintenance; it has not mobile pieces and therefore it lasts for a long time and require little attention once installed. - No energy consumption; solar light continue working even if there has been a power outage. - High quality of light: the colour rendering of light is very high - Psychological benefits: People working with daylight get less stress and more comfort, increasing productivity. - Health benefits

  16. Battery equalization active methods

    NASA Astrophysics Data System (ADS)

    Gallardo-Lozano, Javier; Romero-Cadaval, Enrique; Milanes-Montero, M. Isabel; Guerrero-Martinez, Miguel A.

    2014-01-01

    Many different battery technologies are available for the applications which need energy storage. New researches are being focused on Lithium-based batteries, since they are becoming the most viable option for portable energy storage applications. As most of the applications need series battery strings to meet voltage requirements, battery imbalance is an important matter to be taken into account, since it leads the individual battery voltages to drift apart over time, and premature cells degradation, safety hazards, and capacity reduction will occur. A large number of battery equalization methods can be found, which present different advantages/disadvantages and are suitable for different applications. The present paper presents a summary, comparison and evaluation of the different active battery equalization methods, providing a table that compares them, which is helpful to select the suitable equalization method depending on the application. By applying the same weight to the different parameters of comparison, switch capacitor and double-tiered switching capacitor have the highest ratio. Cell bypass methods are cheap and cell to cell ones are efficient. Cell to pack, pack to cell and cell to pack to cell methods present a higher cost, size, and control complexity, but relatively low voltage and current stress in high-power applications.

  17. Use of different derivatives of D-Val-Leu-Arg for studying kallikrein activities in cat submandibular glands and saliva.

    PubMed

    Garrett, J R; Kidd, A; Kyriacou, K; Smith, R E

    1985-07-01

    Glandular kallikrein shows a special selectivity for D-Val-Leu-Arg-4-methoxy-2-naphthylamide in comparison with other potential oligopeptide substrates and it provides a useful histochemical substrate, although the reaction may not always be specific. However, in cat submandibular saliva, a biochemical assay using the closely related D-Val-Leu-Arg-7-amino-4-trifluoromethylcoumarin (AFC) as substrate, which affords more sensitive detection, showed that soya bean trypsin inhibitor causes no inhibition. This indicates that there are unlikely to be contaminating enzymes competing for the substrate in this body fluid. Support for this observation has been gained by the useful new enzyme overlay membrane technique for fluorescent assessment of reactive bands of enzymes after isoelectric focusing, using membranes of cellulose acetate impregnated with D-Val-Leu-Arg-AFC. Comparison of results after isoelectric focusing of purified cat submandibular kallikrein with samples of cat submandibular saliva confirmed that the substrate is monospecific for kallikrein in saliva of the cat. This knowledge has enabled us to start assessing the dynamics of the secretion of kallikrein by the gland. Testing individual drops of saliva has shown that an amazingly rapid mobilization of kallikrein occurs in high concentrations on sympathetic nerve stimulation. The corresponding oligopeptide-based inhibitor D-Val-Leu-Arg-chloromethyl ketone was found to be strongly inhibitory of the amidase reaction by kallikrein but showed a low specificity for kallikrein. Nevertheless, its effects have been tested in vivo by the intravascular route and it caused an increase in the resting salivary vascular resistance whether administered close-arterially or intravenously. Thus, it would seem that a kallikrein-like protease does influence the background tone in the vessels and the source of this enzyme is thought to be mast cells.

  18. Perspectives in active liquid crystals.

    PubMed

    Majumdar, Apala; Cristina, Marchetti M; Virga, Epifanio G

    2014-11-28

    Active soft matter is a young, growing field, with potential applications to a wide variety of systems. This Theme Issue explores this emerging new field by highlighting active liquid crystals. The collected contributions bridge theory to experiment, mathematical theories of passive and active nematics, spontaneous flows to defect dynamics, microscopic to continuum levels of description, spontaneous activity to biological activation. While the perspectives offered here only span a small part of this rapidly evolving field, we trust that they might provide the interested reader with a taste for this new class of non-equilibrium systems and their rich behaviour.

  19. Recurrent Activity in Radio Galaxies

    SciTech Connect

    Jamrozy, Marek; Konar, Chiranjib; Machalski, Jerzy; Mack, Karl-Heinz; Saikia, Dhruba; Siemiginowska, Aneta; Stawarz, Lukasz; /KIPAC, Menlo Park /Jagiellonian U.

    2007-10-15

    One of the outstanding issues concerning extragalactic radio sources is the total duration of their active phase and the possible existence of duty cycles of their nuclear activity. A duty cycle can be recognized if there is a mechanism which preserves the information of past activity for a sufficiently long time after a new activity has started up. If a new cycle starts before the radio lobes created during a former activity period have faded, we can recognize this by the observations of a young radio source embedded in an old relic structure.

  20. Activated sintering of zirconium dioxide

    NASA Astrophysics Data System (ADS)

    Panin, V. E.; Slosman, A. I.; Matrenin, S. V.

    1996-02-01

    A new phenomenon has been observed — the activated sintering of a zirconium ceramic in the hydrogen-nitrogen plasma of a glow discharge. It is shown that the activation energy is considerably lower than the activation energy for sintering in a vacuum furnace. This makes it possible to reduce sintering temperature, refine the grains, and improve the mechanical properties of the ceramic. It is proposed that the mechanism by which sintering is activated is connected with the activating effect of hydrogen during a structural transformation involving the formation of oxynitride phases.

  1. Global optogenetic activation of inhibitory interneurons during epileptiform activity.

    PubMed

    Ledri, Marco; Madsen, Marita Grønning; Nikitidou, Litsa; Kirik, Deniz; Kokaia, Merab

    2014-02-26

    Optogenetic techniques provide powerful tools for bidirectional control of neuronal activity and investigating alterations occurring in excitability disorders, such as epilepsy. In particular, the possibility to specifically activate by light-determined interneuron populations expressing channelrhodopsin-2 provides an unprecedented opportunity of exploring their contribution to physiological and pathological network activity. There are several subclasses of interneurons in cortical areas with different functional connectivity to the principal neurons (e.g., targeting their perisomatic or dendritic compartments). Therefore, one could optogenetically activate specific or a mixed population of interneurons and dissect their selective or concerted inhibitory action on principal cells. We chose to explore a conceptually novel strategy involving simultaneous activation of mixed populations of interneurons by optogenetics and study their impact on ongoing epileptiform activity in mouse acute hippocampal slices. Here we demonstrate that such approach results in a brief initial action potential discharge in CA3 pyramidal neurons, followed by prolonged suppression of ongoing epileptiform activity during light exposure. Such sequence of events was caused by massive light-induced release of GABA from ChR2-expressing interneurons. The inhibition of epileptiform activity was less pronounced if only parvalbumin- or somatostatin-expressing interneurons were activated by light. Our data suggest that global optogenetic activation of mixed interneuron populations is a more effective approach for development of novel therapeutic strategies for epilepsy, but the initial action potential generation in principal neurons needs to be taken in consideration.

  2. Trypsin activity is not involved in premature, intrapancreatic trypsinogen activation.

    PubMed

    Halangk, Walter; Krüger, Burkhard; Ruthenbürger, Manuel; Stürzebecher, Jörg; Albrecht, Elke; Lippert, Hans; Lerch, Markus M

    2002-02-01

    A premature and intracellular activation of digestive zymogens is thought to be responsible for the onset of pancreatitis. Because trypsin has a critical role in initiating the activation cascade of digestive enzymes in the gut, it has been assumed that trypsin also initiates intracellular zymogen activation in the pancreas. We have tested this hypothesis in isolated acini and lobules from rat pancreas. Intracellular trypsinogen activation was induced by supramaximal secretagogue stimulation and measured using either specific trypsin substrates or immunoreactivity of the trypsinogen activation peptide (TAP). To prevent a trypsin-induced trypsinogen activation, we used the cell-permeant, highly specific, and reversible inhibitor Nalpha-(2-naphthylsulfonyl)-3-amidinophenylalanine-carboxymethylpiperazide (S124), and to prevent cathepsin-induced trypsinogen activation, we used the cysteine protease inhibitor E-64d. Incubation of acini or lobules in the presence of S124 completely prevented the generation of trypsin activity in response to supramaximal caerulein but had no effect whatsoever on the generation of TAP. Conversely, when trypsin activity was recovered at the end of the experiment by either washout of S124 from acini or extensive dilution of lobule homogenates, it was up to 400% higher than after caerulein alone and corresponded, in molar terms, to the generation of TAP. Both trypsin activity and TAP release were inhibited in parallel by E-64d. We conclude that caerulein-induced trypsinogen activation in the pancreas is caused by an E-64d-inhibitable mechanism such as cathepsin-induced trypsinogen activation, and neither involves nor requires intracellular trypsin activity. Specific trypsin inhibition, on the other hand, prevents 80% of trypsin inactivation or autodegradation in the pancreas.

  3. Dynamic Patterns in Active Fluids

    NASA Astrophysics Data System (ADS)

    Jülicher, Frank

    2012-02-01

    Biological matter is inherently dynamic and exhibits active properties. A key example is the force generation by molecular motors in the cell cytoskeleton. Such active processes give rise to the generation of active mechanical stresses and spontaneous flows in gel-like cytoskeletal networks. Active material behaviors play a key role for the dynamics of cellular processes such as cell locomotion and cell division. We will discuss intracellular flow patterns that are created by active processes in the cell cortex. By combining theory with quantitative experiments we show that observed flow patterns result from profiles of active stress generation in the system. We will also consider the situation where active stress is regulated by a diffusing molecular species. In this case, spatial concentration patterns are generated by the interplay of stress regulation and self-generated flow fields.

  4. Active Kids Active Minds: A Physical Activity Intervention to Promote Learning?

    ERIC Educational Resources Information Center

    lisahunter; Abbott, Rebecca; Macdonald, Doune; Ziviani, Jennifer; Cuskelly, Monica

    2014-01-01

    This study assessed the feasibility and impact of introducing a programme of an additional 30 minutes per day of moderate physical activity within curriculum time on learning and readiness to learn in a large elementary school in south-east Queensland, Australia. The programme, Active Kids Active Minds (AKAM), involved Year 5 students (n = 107),…

  5. Strategy as active waiting.

    PubMed

    Sull, Donald N

    2005-09-01

    Successful executives who cut their teeth in stable industries or in developed countries often stumble when they face more volatile markets. They falter, in part, because they assume they can gaze deep into the future and develop a long-term strategy that will confer a sustainable competitive advantage. But visibility into the future of volatile markets is sharply limited because so many different variables are in play. Factors such as technological innovation, customers' evolving needs, government policy, and changes in the capital markets interact with one another to create unexpected outcomes. Over the past six years, Donald Sull, an associate professor at London Business School, has led a research project examining some of the world's most volatile markets, from national markets like China and Brazil to industries like enterprise software, telecommunications, and airlines. One of the most striking findings from this research is the importance of taking action during comparative lulls in the storm. Huge business opportunities are relatively rare; they come along only once or twice in a decade. And, for the most part, companies can't manufacture those opportunities; changes in the external environment converge to make them happen. What managers can do is prepare for these golden opportunities by managing smart during the comparative calm of business as usual. During these periods of active waiting, leaders must probe the future and remain alert to anomalies that signal potential threats or opportunities; exercise restraint to preserve their war chests; and maintain discipline to keep the troops battle ready. When a golden opportunity or"sudden death"threat emerges, managers must have the courage to declare the main effort and concentrate resources to seize the moment.

  6. Mechanically Active Electrospun Materials

    NASA Astrophysics Data System (ADS)

    Robertson, Jaimee M.

    Electrospinning, a technique used to fabricate small diameter polymer fibers, has been employed to develop unique, active materials falling under two categories: (1) shape memory elastomeric composites (SMECs) and (2) water responsive fiber mats. (1) Previous work has characterized in detail the properties and behavior of traditional SMECs with isotropic fibers embedded in an elastomer matrix. The current work has two goals: (i) characterize laminated anisotropic SMECs and (ii) develop a fabrication process that is scalable for commercial SMEC manufacturing. The former ((i)) requires electrospinning aligned polymer fibers. The aligned fibers are similarly embedded in an elastomer matrix and stacked at various fiber orientations. The resulting laminated composite has a unique response to tensile deformation: after stretching and releasing, the composite curls. This curling response was characterized based on fiber orientation. The latter goal ((ii)) required use of a dual-electrospinning process to simultaneously electrospin two polymers. This fabrication approach incorporated only industrially relevant processing techniques, enabling the possibility of commercial application of a shape memory rubber. Furthermore, the approach had the added benefit of increased control over composition and material properties. (2) The strong elongational forces experienced by polymer chains during the electrospinning process induce molecular alignment along the length of electrospun fibers. Such orientation is maintained in the fibers as the polymer vitrifies. Consequently, residual stress is stored in electrospun fiber mats and can be recovered by heating through the polymer's glass transition temperature. Alternatively, the glass transition temperature can be depressed by introducing a plasticizing agent. Poly(vinyl acetate) (PVAc) is plasticized by water, and its glass transition temperature is lowered below room temperature. Therefore, the residual stress can be relaxed at room

  7. Characterization of a novel cell wall binding domain-containing Staphylococcus aureus endolysin LysSA97.

    PubMed

    Chang, Yoonjee; Ryu, Sangryeol

    2017-01-01

    Endolysin from Staphylococcus aureus phage SA97 (LysSA97) was cloned and investigated. LysSA97 specifically lyse the staphylococcal strains and effectively disrupted staphylococcal biofilms. Bioinformatic analysis of LysSA97 revealed a novel putative cell wall binding domain (CBD) as well as two enzymatically active domains (EADs) containing cysteine, histidine-dependent amidohydrolases/peptidases (CHAP, PF05257) and N-acetylmuramoyl-L-alanine amidase (Amidase-3, PF01520) domains. Comparison of 98 endolysin genes of S. aureus phages deposited in GenBank showed that they can be classified into six groups based on their domain composition. Interestingly, approximately 80.61 % of the staphylococcal endolysins have a src-homology 3 (SH3, PF08460) domain as CBD, but the remaining 19.39 %, including LysSA97, has a putative C-terminal CBD with no homology to the known CBD. The fusion protein containing green fluorescent protein and the putative CBD of LysSA97 showed a specific binding spectrum against staphylococcal cells comparable to SH3 domain (PF08460), suggesting that the C-terminal domain of LysSA97 is a novel CBD of staphylococcal endolysins.

  8. AMPK activators: mechanisms of action and physiological activities

    PubMed Central

    Kim, Joungmok; Yang, Goowon; Kim, Yeji; Kim, Jin; Ha, Joohun

    2016-01-01

    AMP-activated protein kinase (AMPK) is a central regulator of energy homeostasis, which coordinates metabolic pathways and thus balances nutrient supply with energy demand. Because of the favorable physiological outcomes of AMPK activation on metabolism, AMPK has been considered to be an important therapeutic target for controlling human diseases including metabolic syndrome and cancer. Thus, activators of AMPK may have potential as novel therapeutics for these diseases. In this review, we provide a comprehensive summary of both indirect and direct AMPK activators and their modes of action in relation to the structure of AMPK. We discuss the functional differences among isoform-specific AMPK complexes and their significance regarding the development of novel AMPK activators and the potential for combining different AMPK activators in the treatment of human disease. PMID:27034026

  9. Fluidization and Active Thinning by Molecular Kinetics in Active Gels.

    PubMed

    Oriola, David; Alert, Ricard; Casademunt, Jaume

    2017-02-24

    We derive the constitutive equations of an active polar gel from a model for the dynamics of elastic molecules that link polar elements. Molecular binding kinetics induces the fluidization of the material, giving rise to Maxwell viscoelasticity and, provided that detailed balance is broken, to the generation of active stresses. We give explicit expressions for the transport coefficients of active gels in terms of molecular properties, including nonlinear contributions on the departure from equilibrium. In particular, when activity favors linker unbinding, we predict a decrease of viscosity with activity-active thinning-of kinetic origin, which could explain some experimental results on the cell cortex. By bridging the molecular and hydrodynamic scales, our results could help understand the interplay between molecular perturbations and the mechanics of cells and tissues.

  10. Being active when you have heart disease

    MedlinePlus

    Heart disease - activity; CAD - activity; Coronary artery disease - activity; Angina - activity ... Getting regular exercise when you have heart disease is important. Exercise can make your heart muscle stronger. It may also help you be more active without chest pain or ...

  11. Rest Rust ! Physical active for active and healthy ageing

    PubMed Central

    Vollenbroek-Hutten, M; Pais, S; Ponce, S; Dekker-van Weering, M; Jansen-Kosterink, S; Schena, F; Tabarini, N; Carotenuto, F; Iadicicco, V; Illario, M

    2015-01-01

    The aim of this paper is to give an insight on how physical activity can be defined, parameterized and measured in older adults and on different options to deal with citizen physical activity promotion at European level. Three relevant aspects are highlighted: When talking about physical activity, two different aspects are often unfairly mixed up: “physical activity” and “physical capacity”. Physical activity, is referred to as the level of physical activity someone is actually performing in daily life.Physical capacity is referred to as the maximum physical activity a person can perform.Both physical activity and physical capacity can be expressed in different dimensions such as time, frequency, or type of activity with the consequence that there are many tools and techniques available. In order to support people to choose an appropriate instrument in their everyday practice a list of 9 criteria that are considered important is defined.Older adults score differently across the various physical dimensions, so strategies to promote physical activity should consider individual differences, in order to adapt for these variations. PMID:27042429

  12. Activated coconut shell charcoal carbon using chemical-physical activation

    NASA Astrophysics Data System (ADS)

    Budi, Esmar; Umiatin, Nasbey, Hadi; Bintoro, Ridho Akbar; Wulandari, Futri; Erlina

    2016-02-01

    The use of activated carbon from natural material such as coconut shell charcoal as metal absorbance of the wastewater is a new trend. The activation of coconut shell charcoal carbon by using chemical-physical activation has been investigated. Coconut shell was pyrolized in kiln at temperature about 75 - 150 °C for about 6 hours in producing charcoal. The charcoal as the sample was shieved into milimeter sized granule particle and chemically activated by immersing in various concentration of HCl, H3PO4, KOH and NaOH solutions. The samples then was physically activated using horizontal furnace at 400°C for 1 hours in argon gas environment with flow rate of 200 kg/m3. The surface morphology and carbon content of activated carbon were characterized by using SEM/EDS. The result shows that the pores of activated carbon are openned wider as the chemical activator concentration is increased due to an excessive chemical attack. However, the pores tend to be closed as further increasing in chemical activator concentration due to carbon collapsing.

  13. Silicon active photonic devices

    NASA Astrophysics Data System (ADS)

    Dimitropoulos, Dimitrios

    Active photonic devices utilizing the optical nonlinearities of silicon have emerged in the last 5 years and the effort for commercial photonic devices in the material that has been the workhorse of electronics has been building up since. This dissertation presents the theory for some of these devices. We are concerned herein with CW lasers, amplifiers and wavelength converters that are based on the Raman effect. There have already been cursory experimental demonstrations of these devices and some of their limitations are already apparent. Most of the limitations observed are because of the appearance of effects that are competing with stimulated Raman scattering. Under the high optical powers that are necessary for the Raman effect (tens to hundrends of mW's) the process of optical two-photon (TPA) absorption occurs. The absorption of optical power that it causes itself is weak but in the process electrons and holes are generated which can further absorb light through the free-carrier absorption effect (FCA). The effective "lifetime" that these carriers have determines the magnitude of the FCA loss. We present a model for the carrier lifetime in Silicon-On-Insulator (SOI) waveguides and numerical simulations to understand how this critical parameter varies and how it can be controlled. A p-i-n junction built along SOI waveguides can help achieve lifetime of the order of 20--100 ps but the price one has to pay is on-chip electrical power consumption on the order of 100's of mWs. We model CW Raman lasers and we find that the carrier lifetime reduces the output power. If the carrier lifetime exceeds a certain "critical" value optical losses become overwhelming and lasing is impossible. As we show, in amplifiers, the nonlinear loss does not only result in diminished gain, but also in a higher noise figure. Finally the effect of Coherent anti-Stokes Raman scattering (CARS) is examined. The effect is important because with a pump frequency at 1434nm coherent power

  14. Rapid Active Sampling Package

    NASA Technical Reports Server (NTRS)

    Peters, Gregory

    2010-01-01

    A field-deployable, battery-powered Rapid Active Sampling Package (RASP), originally designed for sampling strong materials during lunar and planetary missions, shows strong utility for terrestrial geological use. The technology is proving to be simple and effective for sampling and processing materials of strength. Although this originally was intended for planetary and lunar applications, the RASP is very useful as a powered hand tool for geologists and the mining industry to quickly sample and process rocks in the field on Earth. The RASP allows geologists to surgically acquire samples of rock for later laboratory analysis. This tool, roughly the size of a wrench, allows the user to cut away swaths of weathering rinds, revealing pristine rock surfaces for observation and subsequent sampling with the same tool. RASPing deeper (.3.5 cm) exposes single rock strata in-situ. Where a geologist fs hammer can only expose unweathered layers of rock, the RASP can do the same, and then has the added ability to capture and process samples into powder with particle sizes less than 150 microns, making it easier for XRD/XRF (x-ray diffraction/x-ray fluorescence). The tool uses a rotating rasp bit (or two counter-rotating bits) that resides inside or above the catch container. The container has an open slot to allow the bit to extend outside the container and to allow cuttings to enter and be caught. When the slot and rasp bit are in contact with a substrate, the bit is plunged into it in a matter of seconds to reach pristine rock. A user in the field may sample a rock multiple times at multiple depths in minutes, instead of having to cut out huge, heavy rock samples for transport back to a lab for analysis. Because of the speed and accuracy of the RASP, hundreds of samples can be taken in one day. RASP-acquired samples are small and easily carried. A user can characterize more area in less time than by using conventional methods. The field-deployable RASP used a Ni

  15. Enhanced NIF neutron activation diagnostics.

    PubMed

    Yeamans, C B; Bleuel, D L; Bernstein, L A

    2012-10-01

    The NIF neutron activation diagnostic suite relies on removable activation samples, leading to operational inefficiencies and a fundamental lower limit on the half-life of the activated product that can be observed. A neutron diagnostic system measuring activation of permanently installed samples could remove these limitations and significantly enhance overall neutron diagnostic capabilities. The physics and engineering aspects of two proposed systems are considered: one measuring the (89)Zr/(89 m)Zr isomer ratio in the existing Zr activation medium and the other using potassium zirconate as the activation medium. Both proposed systems could improve the signal-to-noise ratio of the current system by at least a factor of 5 and would allow independent measurement of fusion core velocity and fuel areal density.

  16. CDPK Activation in PRR Signaling.

    PubMed

    Seybold, Heike; Boudsocq, Marie; Romeis, Tina

    2017-01-01

    Calcium-dependent protein kinases undergo a rapid biochemical activation in response to an intracellular Ca increase induced by the PRR-dependent perception of a pathogen-related stimulus. Based on SDS gel resolution, the in-gel kinase assay allows the analysis of multiple in vivo protein samples in parallel, combining the advantage of protein separation according to molecular mass with the activity read-out of a protein kinase assay. It thus enables to follow the transient CDPK activation and inactivation in response to in vivo elicitation with a time-wise resolution. In addition, changes of CDPK phosphorylation activity often correlate with slight shifts in the enzyme's apparent molecular mass, indicating posttranslational modifications and a conformational change of the active enzyme compared to its inactive resting form. These band shifts can be detected by a simple immunoblotting to monitor CDPK activation.

  17. Swim pressure of active matter

    NASA Astrophysics Data System (ADS)

    Takatori, Sho; Yan, Wen; Brady, John; Caltech Team

    2014-11-01

    Through their self-motion, all active matter systems generate a unique ``swim pressure'' that is entirely athermal in origin. This new source for the active stress exists at all scales in both living and nonliving active systems, and also applies to larger organisms where inertia is important (i.e., the Stokes number is not small). Here we explain the origin of the swim stress and develop a simple thermodynamic model to study the self-assembly and phase separation in active soft matter. Our new swim stress perspective can help analyze and exploit a wide class of active soft matter, from swimming bacteria and catalytic nanobots, schools of fish and birds, and molecular motors that activate the cellular cytoskeleton.

  18. Enhanced NIF neutron activation diagnostics

    SciTech Connect

    Yeamans, C. B.; Bleuel, D. L.; Bernstein, L. A.

    2012-10-15

    The NIF neutron activation diagnostic suite relies on removable activation samples, leading to operational inefficiencies and a fundamental lower limit on the half-life of the activated product that can be observed. A neutron diagnostic system measuring activation of permanently installed samples could remove these limitations and significantly enhance overall neutron diagnostic capabilities. The physics and engineering aspects of two proposed systems are considered: one measuring the {sup 89}Zr/{sup 89m}Zr isomer ratio in the existing Zr activation medium and the other using potassium zirconate as the activation medium. Both proposed systems could improve the signal-to-noise ratio of the current system by at least a factor of 5 and would allow independent measurement of fusion core velocity and fuel areal density.

  19. Active Cells for Multifunctional Structures

    DTIC Science & Technology

    2014-09-24

    techniques to explore a variety of cell designs.  Designed a simplified active cell using Nitinol as the actuation method and relying on Joule heating...for contraction of the cell.  Developed manufacturing techniques for reliably creating Nitinol spring coils in a variety of diameters and gauges...design of the active cells to maximum the stroked length of the active cells by tuning the stiffness of a passive spring in parallel with the Nitinol

  20. Antiangiogenic Activity of Glycyrrhiza Extract

    NASA Astrophysics Data System (ADS)

    Li, Ying-Qiu

    The bioactivity of extract of glycyrrhiza was detected by zebrafish antiangiogenic model after 70% ethanol extract of glycyrrhiza was extracted with petroleum ether, ethyl acetate, n-butanol. The inhibition of the extracts in antiangiogenic activity showed that the highest active components existed in ethyl acetate extract of glycyrrhiza. The ethyl acetate extract of glycyrrhiza was separated by polyamide column chromatography to obtain 7 fractions (Fr1-Fr7), which Fr5 and Fr6 showed antiangiogenic activity.

  1. In Situ Activation of Microcapsules

    NASA Technical Reports Server (NTRS)

    Morrison, Dennis R. (Inventor); Mosier, Benjamin (Inventor)

    2000-01-01

    Disclosed are microcapsules comprising a polymer shell enclosing two or more immiscible liquid phases in which a drug, or a prodrug and a drug activator are partitioned into separate phases. or prevented from diffusing out of the microcapsule by a liquid phase in which the drug is poorly soluble. Also disclosed are methods of using the microcapsules for in situ activation of drugs where upon exposure to an appropriate energy source the internal phases mix and the drug is activated in situ.

  2. Macrophage Biochemistry, Activation and Function

    DTIC Science & Technology

    1981-01-01

    glucoeidase +8 . . Sulfatase c +8 Modified from Morahan, 1980. b(+)Exhibit@ activity; (-) lacks activity; (+) weak or marginal activity. ’References: (1...endoplasmic reticulum enzymes, sulfatase c and alkaline a-glucosidase. Dissociation of the lysosomal enzyme patterns from sulfatase c and alkaline r...1974; Beaufay et al., 1974). Peritoneal macrophages are deficient or contain inauf- • -𔃼 :’- 41 ficient quantities of the classical constituents to be

  3. L3 Study Team Activities

    NASA Astrophysics Data System (ADS)

    Shoemaker, David; L3ST Team

    2017-01-01

    The NASA-Chartered L3 Study Team is working to develop the US community participation and to support NASA's contribution to the ESA-led LISA mission to observe gravitational waves via space-based detectors. The present activities of the L3ST will be described, and the next steps for the Study Team will also be given. NASA supports travel activities and support for the Study Team activities.

  4. Active auditory mechanics in mosquitoes.

    PubMed Central

    Göpfert, M. C.; Robert, D.

    2001-01-01

    In humans and other vertebrates, hearing is improved by active contractile properties of hair cells. Comparable active auditory mechanics is now demonstrated in insects. In mosquitoes, Johnston's organ transduces sound-induced vibrations of the antennal flagellum. A non-muscular 'motor' activity enhances the sensitivity and tuning of the flagellar mechanical response in physiologically intact animals. This motor is capable of driving the flagellum autonomously, amplifying sound-induced vibrations at specific frequencies and intensities. Motor-related electrical activity of Johnston's organ strongly suggests that mosquito hearing is improved by mechanoreceptor motility. PMID:11270428

  5. Geomagnetic response to solar activity.

    NASA Technical Reports Server (NTRS)

    Mead, G. D.

    1972-01-01

    The relationship between solar activity and geomagnetic variations is discussed in the light of spacecraft data obtained during the last decade. The effects of centers of solar activity responsible for producing geomagnetic activity on earth are believed to be transmitted through the solar wind, and there is usually a delay of two or three days before the onset of magnetic activity. Attempts to make a one-to-one correspondence between specific solar events and specific magnetic storms, however, are usually unsuccessful, because of the complex and indirect processes linking the two phenomena. Normally, only statistical tendencies can be shown.

  6. Activated T lymphocytes in uveitis.

    PubMed Central

    Deschênes, J.; Char, D. H.; Kaleta, S.

    1988-01-01

    Two colour flow cytometry techniques were used to assess the activation stages of peripheral and intraocular T lymphocytes in uveitis. Increased numbers of T lymphocytes bearing the interleukin-2 (IL-2) receptors were found in intraocular fluids or peripheral blood or both of 35/51 patients with uveitis. This increased expression of IL-2 receptors on lymphocytes correlated with increased expression of other early T lymphocyte activation markers, HLA-DR and L-35. Both T helper cells (Leu-3A+) and suppressor cells (Leu 2A+) were activated in vivo. A positive correlation was seen between lymphocyte activation and clinical uveitis activity. In idiopathic uveitis activation of Leu-3A lymphocytes (helper/inducer) was significantly increased, and intraocular activation of the Leu-2A lymphocytes (cytotoxic/suppressor) was significantly decreased. These data show that some patients with idiopathic uveitis have a perturbation of T helper cells. Twenty-two of 31 patients with idiopathic uveitis, not associated with systemic disease, had increased peripheral T lymphocyte activation. This finding indicates that in some inflammations believed to be restricted to the eye an abnormal systemic immune activation exists. PMID:2964862

  7. Active surveillance for prostate cancer.

    PubMed

    Romero-Otero, Javier; García-Gómez, Borja; Duarte-Ojeda, José M; Rodríguez-Antolín, Alfredo; Vilaseca, Antoni; Carlsson, Sigrid V; Touijer, Karim A

    2016-03-01

    It is worth distinguishing between the two strategies of expectant management for prostate cancer. Watchful waiting entails administering non-curative androgen deprivation therapy to patients on development of symptomatic progression, whereas active surveillance entails delivering curative treatment on signs of disease progression. The objectives of the two management strategies and the patients enrolled in either are different: (i) to review the role of active surveillance as a management strategy for patients with low-risk prostate cancer; and (ii) review the benefits and pitfalls of active surveillance. We carried out a systematic review of active surveillance for prostate cancer in the literature using the National Center for Biotechnology Information's electronic database, PubMed. We carried out a search in English using the terms: active surveillance, prostate cancer, watchful waiting and conservative management. Selected studies were required to have a comprehensive description of the demographic and disease characteristics of the patients at the time of diagnosis, inclusion criteria for surveillance, and a protocol for the patients' follow up. Review articles were included, but not multiple papers from the same datasets. Active surveillance appears to reduce overtreatment in patients with low-risk prostate cancer without compromising cancer-specific survival at 10 years. Therefore, active surveillance is an option for select patients who want to avoid the side-effects inherent to the different types of immediate treatment. However, inclusion criteria for active surveillance and the most appropriate method of monitoring patients on active surveillance have not yet been standardized.

  8. International Activities Related to Pesticides

    EPA Pesticide Factsheets

    Regulating pesticides involves many international issues and working with our regulatory partners in other countries. Learn about EPA's activities, upcoming meetings and workshops, and various regulatory issues.

  9. Physical Activity and Cancer Survivorship

    PubMed Central

    Garcia, David O.; Thomson, Cynthia A.

    2015-01-01

    There has been an increase in the cancer survivor population in the United States over the past several decades primarily due to improvements in early detection of first malignancies and effective treatment modalities. A wealth of evidence has demonstrated that regular physical activity is associated with a lower risk of death, all-cause mortality, cancer recurrence, and several chronic diseases, including type 2 diabetes and cardiovascular disease, common comorbid conditions in people who have survived cancer. Physical activity also is a central component of weight management. Methods This review summarizes the current physical activity recommendations and the evidence linking physical activity to improvements in weight management, physiological effects, and psychological health outcomes for cancer survivors. Results The available literature suggests physical activity is safe and is positively associated with weight management, cardiorespiratory fitness, muscular strength and endurance, quality of life, fatigue, and other psychosocial factors in cancer survivors. Yet relationships related to specific cancer diagnoses, treatments, and underlying cardiometabolic mechanisms associated with survival have not been thoroughly examined in randomized controlled trials. Furthermore, factors that influence adherence to physical activity behaviors must be identified to develop effective exercise programs. The use of objective measures of physical activity and the standardization of reporting outcome measures within intervention trials are needed to complement this effort. Conclusions Healthcare providers should consider individual differences among cancer survivors and tailor physical activity programs to meet the individual needs of the patient to assist in the adoption and maintenance of a physically active lifestyle. PMID:25335787

  10. Studies in geophysics: Active tectonics

    NASA Technical Reports Server (NTRS)

    1986-01-01

    Active tectonics is defined within the study as tectonic movements that are expected to occur within a future time span of concern to society. Such movements and their associated hazards include earthquakes, volcanic eruptions, and land subsidence and emergence. The entire range of geology, geophysics, and geodesy is, to some extent, pertinent to this topic. The needs for useful forecasts of tectonic activity, so that actions may be taken to mitigate hazards, call for special attention to ongoing tectonic activity. Further progress in understanding active tectonics depends on continued research. Particularly important is improvement in the accuracy of dating techniques for recent geologic materials.

  11. Demand Activated Manufacturing Architecture

    SciTech Connect

    Bender, T.R.; Zimmerman, J.J.

    2001-02-07

    Honeywell Federal Manufacturing & Technologies (FM&T) engineers John Zimmerman and Tom Bender directed separate projects within this CRADA. This Project Accomplishments Summary contains their reports independently. Zimmerman: In 1998 Honeywell FM&T partnered with the Demand Activated Manufacturing Architecture (DAMA) Cooperative Business Management Program to pilot the Supply Chain Integration Planning Prototype (SCIP). At the time, FM&T was developing an enterprise-wide supply chain management prototype called the Integrated Programmatic Scheduling System (IPSS) to improve the DOE's Nuclear Weapons Complex (NWC) supply chain. In the CRADA partnership, FM&T provided the IPSS technical and business infrastructure as a test bed for SCIP technology, and this would provide FM&T the opportunity to evaluate SCIP as the central schedule engine and decision support tool for IPSS. FM&T agreed to do the bulk of the work for piloting SCIP. In support of that aim, DAMA needed specific DOE Defense Programs opportunities to prove the value of its supply chain architecture and tools. In this partnership, FM&T teamed with Sandia National Labs (SNL), Division 6534, the other DAMA partner and developer of SCIP. FM&T tested SCIP in 1998 and 1999. Testing ended in 1999 when DAMA CRADA funding for FM&T ceased. Before entering the partnership, FM&T discovered that the DAMA SCIP technology had an array of applications in strategic, tactical, and operational planning and scheduling. At the time, FM&T planned to improve its supply chain performance by modernizing the NWC-wide planning and scheduling business processes and tools. The modernization took the form of a distributed client-server planning and scheduling system (IPSS) for planners and schedulers to use throughout the NWC on desktops through an off-the-shelf WEB browser. The planning and scheduling process within the NWC then, and today, is a labor-intensive paper-based method that plans and schedules more than 8,000 shipped parts

  12. Platelet activating factor activity in the phospholipids of bovine spermatozoa

    SciTech Connect

    Parks, J.E.; Hough, S.; Elrod, C. )

    1990-11-01

    Platelet activating factor (PAF) has been detected in sperm from several mammalian species and can affect sperm motility and fertilization. Because bovine sperm contain a high percentage of ether-linked phospholipid precursors required for PAF synthesis, a study was undertaken to determine the PAF activity of bovine sperm phospholipids. Total lipids of washed, ejaculated bull sperm were extracted, and phospholipids were fractionated by thin-layer chromatography. Individual phospholipid fractions were assayed for PAF activity on the basis of (3H)serotonin release from equine platelets. PAF activity was detected in the PAF fraction (1.84 pmol/mumol total phospholipid) and in serine/inositol (PS/PI), choline (CP), and ethanolamine phosphoglyceride (EP) and cardiolipin (CA) fractions. Activity was highest in the CP fraction (8.05 pmol/mumol total phospholipid). Incomplete resolution of PAF and neutral lipids may have contributed to the activity in the PS/PI and CA fractions, respectively. Phospholipids from nonsperm sources did not stimulate serotonin release. Platelet activation by purified PAF and by sperm phospholipid fractions was inhibited by the receptor antagonist SRI 63-675. These results indicate that bovine sperm contain PAF and that other sperm phospholipids, especially CP and EP, which are high in glycerylether components, are capable of receptor-mediated platelet activation.

  13. Brain activation associated with active and passive lower limb stepping

    PubMed Central

    Jaeger, Lukas; Marchal-Crespo, Laura; Wolf, Peter; Riener, Robert; Michels, Lars; Kollias, Spyros

    2014-01-01

    Reports about standardized and repeatable experimental procedures investigating supraspinal activation in patients with gait disorders are scarce in current neuro-imaging literature. Well-designed and executed tasks are important to gain insight into the effects of gait-rehabilitation on sensorimotor centers of the brain. The present study aims to demonstrate the feasibility of a novel imaging paradigm, combining the magnetic resonance (MR)-compatible stepping robot (MARCOS) with sparse sampling functional magnetic resonance imaging (fMRI) to measure task-related BOLD signal changes and to delineate the supraspinal contribution specific to active and passive stepping. Twenty-four healthy participants underwent fMRI during active and passive, periodic, bilateral, multi-joint, lower limb flexion and extension akin to human gait. Active and passive stepping engaged several cortical and subcortical areas of the sensorimotor network, with higher relative activation of those areas during active movement. Our results indicate that the combination of MARCOS and sparse sampling fMRI is feasible for the detection of lower limb motor related supraspinal activation. Activation of the anterior cingulate and medial frontal areas suggests motor response inhibition during passive movement in healthy participants. Our results are of relevance for understanding the neural mechanisms underlying gait in the healthy. PMID:25389396

  14. Active Brownian particles with velocity-alignment and active fluctuations

    NASA Astrophysics Data System (ADS)

    Großmann, R.; Schimansky-Geier, L.; Romanczuk, P.

    2012-07-01

    We consider a model of active Brownian particles (ABPs) with velocity alignment in two spatial dimensions with passive and active fluctuations. Here, active fluctuations refers to purely non-equilibrium stochastic forces correlated with the heading of an individual active particle. In the simplest case studied here, they are assumed to be independent stochastic forces parallel (speed noise) and perpendicular (angular noise) to the velocity of the particle. On the other hand, passive fluctuations are defined by a noise vector independent of the direction of motion of a particle, and may account, for example, for thermal fluctuations. We derive a macroscopic description of the ABP gas with velocity-alignment interaction. Here, we start from the individual-based description in terms of stochastic differential equations (Langevin equations) and derive equations of motion for the coarse-grained kinetic variables (density, velocity and temperature) via a moment expansion of the corresponding probability density function. We focus here on the different impact of active and passive fluctuations on onset of collective motion and show how active fluctuations in the active Brownian dynamics can change the phase-transition behaviour of the system. In particular, we show that active angular fluctuations lead to an earlier breakdown of collective motion and to the emergence of a new bistable regime in the mean-field case.

  15. From Physical Activity Guidelines to a National Activity Plan

    ERIC Educational Resources Information Center

    Bornstein, Daniel B.; Pate, Russell R.

    2014-01-01

    The U.S. National Physical Activity Plan (NPAP) is a comprehensive strategic plan aimed at increasing physical activity levels in all segments of the American population. The purpose of this paper is to summarize the development of the NPAP, provide an update on the status of the NPAP, and comment on the future of the NPAP. The NPAP was released…

  16. How Active Are Your Students? Increasing Physical Activity in Schools

    ERIC Educational Resources Information Center

    Avery, Marybell; Brandt, Janet

    2010-01-01

    The U. S. Department of Health and Human Services recommends that youth engage in at least 60 minutes of physical activity each day, most of which should be either moderate- or vigorous-intensity aerobic physical activity. Half of this amount (30 minutes) should be achieved during the school day. NASPE provides guidance in the form of a…

  17. Reading Aloud Activity in L2 and Cerebral Activation

    ERIC Educational Resources Information Center

    Takeuchi, Osamu; Ikeda, Maiko; Mizumoto, Atsushi

    2012-01-01

    This article explores the cerebral mechanism of reading aloud activities in L2 learners. These activities have been widely used in L2 learning and teaching, and its effect has been reported in various Asian L2 learning contexts. However, the reasons for its effectiveness have not been examined. In order to fill in this gap, two studies using a…

  18. 101 Environmental Education Activities. Booklet 3--Mathematics Activities.

    ERIC Educational Resources Information Center

    Schaljo, Roger, Comp.

    Each of the 14 environment-related mathematics activities included in this publication by the Upper Mississippi River ECO-Center includes objectives, materials needed, preparation, and activity description. Occasionally, variations and helpful hints are added. Because the student can gain experience to help him with the practical application of…

  19. Active microrheology in active matter systems: Mobility, intermittency, and avalanches.

    PubMed

    Reichhardt, C; Reichhardt, C J Olson

    2015-03-01

    We examine the mobility and velocity fluctuations of a driven particle moving through an active matter bath of self-mobile disks for varied density or area coverage and varied activity. We show that the driven particle mobility can exhibit nonmonotonic behavior that is correlated with distinct changes in the spatiotemporal structures that arise in the active media. We demonstrate that the probe particle velocity distributions exhibit specific features in the different dynamic regimes and identify an activity-induced uniform crystallization that occurs for moderate activity levels and is distinct from the previously observed higher activity cluster phase. The velocity distribution in the cluster phase has telegraph noise characteristics produced when the probe particle moves alternately through high-mobility areas that are in the gas state and low-mobility areas that are in the dense phase. For higher densities and large activities, the system enters what we characterize as an active jamming regime. Here the probe particle moves in intermittent jumps or avalanches that have power-law-distributed sizes that are similar to the avalanche distributions observed for nonactive disk systems near the jamming transition.

  20. Basic Business and Economics: Varied Activities Encourage Active Student Involvement.

    ERIC Educational Resources Information Center

    Baker, Robert Lee, Jr.

    1978-01-01

    Describes a variety of activities for the basic business classroom, such as having guest speakers, question-and-answer sessions, simulations, role playing, debates, small group work, field trips, games, and individualized instruction. Includes a report of business teachers' knowledge of and attitudes toward these activities. (MF)