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1

Minimum inhibitory concentration of carbapenems and tigecycline against Salmonella spp.  

PubMed

Antimicrobial resistance in Salmonella spp. is of grave concern, more so in quinolone-resistant and extended-spectrum beta-lactamase (ESBL)-producing isolates that cause complicated infections. The MIC of azithromycin, ciprofloxacin, cefixime, cefepime, ceftriaxone, gatifloxacin, imipenem, levofloxacin, meropenem and ofloxacin (E-test strip) and tigecycline and faropenem (agar dilution) against 210 Salmonella spp. was determined. MIC(90) (defined as the antimicrobial concentration that inhibited growth of 90 % of the strains) of the carbapenems (imipenem and meropenem) for Salmonella Typhi and Salmonella Paratyphi A was 0.064 microg ml(-1). MIC(90) of faropenem was 0.25 microg ml(-1) for S. Typhi, S. Paratyphi A and Salmonella Typhimurium. The MIC(90) of azithromycin for all Salmonella spp. ranged from 8 to 16 microg ml(-1). Tigecycline showed an MIC(90) of 2 microg ml(-1) for S. Typhi, 1 microg ml(-1) for S. Paratyphi A and 4 microg ml(-1) for S. Typhimurium. We concluded that tigecycline and the carbapenems are likely to have roles in the final stage of treatment of quinolone-resistant and ESBL-producing multidrug-resistant salmonellae. PMID:19208884

Capoor, Malini R; Nair, Deepthi; Posti, Jitendra; Singhal, Smita; Deb, Monorama; Aggarwal, Pushpa; Pillai, Parukutty

2009-03-01

2

Minimum antimicrobial inhibitory concentration of carnosol and of the ethanol extract from Lepichinia hastata (Lamiaceae).  

PubMed

The minimum inhibitory concentrations (MIC) of carnosol and of the ethanolic extract from the aerial part of Lepechinia hastata were determined against Streptococcus pyogenes, Bacillus subtilis, Staphylococcus aureus, S. epidermidis, S. aureus (2), S. aureus "A", and S. aureus "B", (strains "A" and "B" are resistant to penicillin and ampicillin), Escherichia coli, Enterobacter cloacae, Klebsiella pneumoniae, Salmonella typhimurium, Proteus vulgaris, and Pseudomonas aeruginosa and Candida albicans. Carnosol and the ethanol extract showed activity against gram (+) bacteria, but no activity against the yeast and the gram (-) bacteria. PMID:23195903

Encarnación-Dimayuga, R; Almada, G; Virgen, M

1998-08-01

3

Minimum inhibitory concentrations of medicinal plants used in Northern Peru as antibacterial remedies  

PubMed Central

Aim The plant species reported here are traditionally used in Northern Peru to treat bacterial infections, often addressed by the local healers as “inflammation”. The aim of this study was to evaluate the Minimum Inhibitory Concentration (MIC) of their antibacterial properties against Gram-positive and Gram-negative bacteria. Materials and methods The antimicrobial activity of ethanolic and water extracts of 141 plant species was determined using a deep-well broth microdilution method on commercially available bacterial strains. Results The ethanolic extracts of 51 species inhibited Escherichia coli, and 114 ethanolic extracts inhibited Staphylococcus aureus. In contrast, only 30 aqueous extracts showed activity against E. coli and 38 extracts against S. aureus. The MIC concentrations were mostly very high and ranged from 0.008 to 256mg/ml, with only 36 species showing inhibitory concentrations of <4mg/ml. The ethanolic extracts exhibited stronger activity and a much broader spectrum of action than the aqueous extracts. Hypericum laricifolium, Hura crepitans, Caesalpinia paipai, Cassia fistula, Hyptis sidifolia, Salvia sp., Banisteriopsis caapi, Miconia salicifolia and Polygonum hydropiperoides showed the lowest MIC values and would be interesting candidates for future research. Conclusions The presence of antibacterial activity could be confirmed in most species used in traditional medicine in Peru which were assayed in this study. However, the MIC for the species employed showed a very large range, and were mostly very high. Nevertheless, traditional knowledge might provide some leads to elucidate potential candidates for future development of new antibiotic agents.

Malca-Garcia, G.; Glenn, A.; Sharon, D.; Chait, G.; Diaz, D.; Pourmand, K.; Jonat, B.; Somogy, S.; Guardado, G.; Aguirre, C.; Chan, R.; Meyer, K.; Kuhlman, A.; Townesmith, A.; Effio-Carbajal, J.; Frias-Fernandez, F.; Benito, M.

2010-01-01

4

Minimum inhibitory concentrations of some antimicrobial drugs against bacteria causing uterine infections in cattle.  

PubMed

The minimum inhibitory concentrations (MICs) of oxytetracycline, cephapirin, cephapirin/mecillinam, cefquinome, ceftiofur and enrofloxacin, candidate antibiotics for the principal bacteria associated with uterine infections: Escherichia coli, Arcanobacterium pyogenes and the anaerobic bacteria Fusobacterium necrophorum and Prevotella melaninogenicus, were determined by the agar dilution method. The bacteria were isolated from animals with clinical metritis and/or endometritis. For E coli, cefquinome and enrofloxacin had the lowest MIC90 and MIC50 values (< 0.06 microg/ml), and oxytetracycline and cephapirin had the highest values. For A pyogenes, oxytetracycline had the highest MIC50 value (16 microg/ml), but all the cephalosporins had values below 0.06 microg/ml. For the anaerobic bacteria, enrofloxacin and oxytetracycline had the highest MIC50 values but all the cephalosporins had values of 0.06 microg/ml or below. PMID:15499809

Sheldon, I M; Bushnell, M; Montgomery, J; Rycroft, A N

2004-09-25

5

Minimum inhibitory concentrations for selected antimicrobial agents against Fusobacterium necrophorum isolated from hepatic abscesses in cattle and sheep.  

PubMed

Minimum inhibitory concentrations for 35 antimicrobial agents against 100 Fusobacterium necrophorum isolates from hepatic abscesses in sheep and cattle were determined. Twelve of the thirteen beta-lactam antibiotics tested inhibited growth of 100% of strains tested. Of the remaining antimicrobial agents, extensive susceptibility was found for: spiramycin, josamycin, lincomycin, tylosin, oxytetracycline, chlortetracycline, rufloxacin, metronidazole, cotrimoxazole, sulfadimethoxine, virginiamycin and fosfomycin. PMID:9049945

Mateos, E; Piriz, S; Valle, J; Hurtado, M; Vadillo, S

1997-02-01

6

Relationships between vancomycin minimum inhibitory concentration, dosing strategies, and outcomes in methicillin-resistant Staphylococcus aureus bacteremia  

Microsoft Academic Search

Retrospective study aimed to examine outcomes of methicillin-resistant Staphylococcus aureus (MRSA) bacteremia in relationship to vancomycin minimum inhibitory concentration (VAN MIC) and serum trough concentrations among subjects who had ?1 blood culture positive for MRSA between April 2008 and August 2009. Treatment failure occurred in 7\\/24 (29%) subjects with VAN MIC = 2 mg\\/L versus 20\\/94 (21%) subjects with VAN

Evan C. Clemens; Jeannie D. Chan; John B. Lynch; Timothy H. Dellit

7

Evaluation of minimum inhibitory and minimum bactericidal concentration of nano-silver base inorganic anti-microbial agent (Novaron®) against streptococcus mutans  

PubMed Central

Objective: We attempted to find the possibility of determining the minimum inhibitory concentration and minimum bactericidal concentration needed for nano-silver base inorganic anti-microbial agent (Novaron® AG 300, AG 1100) against Streptococcus mutans in vitro using broth dilution assay. Materials and Methods: An ampoule of freeze-dried S. mutans NCTC reference strain was revived, and the colony-forming units (CFU) were calculated. The MIC and MBC was determined by broth dilution assay using different concentrations of Novaron® AG 300 and Novaron® AG 1100 against 1 × 105 CFU/ml of S. mutans. Results: The MIC and MBC of Novaron® AG 300 and Novaron® AG 1100 against S. mutans were found to be 40 ?g/ml. Conclusions: Novaron® has anti-bacterial effect against S. mutans. Further studies are needed to explore the applicability of these silver-supported anti- microbial agents in clinical dentistry.

Holla, Goda; Yeluri, Ramakrishna; Munshi, Autar Krishen

2012-01-01

8

Relationships between vancomycin minimum inhibitory concentration, dosing strategies, and outcomes in methicillin-resistant Staphylococcus aureus bacteremia.  

PubMed

Retrospective study aimed to examine outcomes of methicillin-resistant Staphylococcus aureus (MRSA) bacteremia in relationship to vancomycin minimum inhibitory concentration (VAN MIC) and serum trough concentrations among subjects who had ?1 blood culture positive for MRSA between April 2008 and August 2009. Treatment failure occurred in 7/24 (29%) subjects with VAN MIC = 2 mg/L versus 20/94 (21%) subjects with VAN MIC ?1.5 mg/L (adjusted OR 1.11, 95% confidence interval [CI] 0.24-5.14). Among subjects who had documented VAN serum trough concentrations, treatment failure occurred in 5/26 (19%) subjects with concentrations <15 mg/L versus 18/68 (27%) subjects with concentrations ?15 mg/L (adjusted OR 0.91, 95% CI 0.21-3.84). In conclusion, treatment outcomes were similar regardless of VAN MIC, although there was a non-statistically significant trend towards decreased clinical efficacy among patients with VAN MIC = 2 mg/L. Optimization of VAN pharmacokinetic indices did not appear to correlate with clinical responses. PMID:21924852

Clemens, Evan C; Chan, Jeannie D; Lynch, John B; Dellit, Timothy H

2011-12-01

9

[Minimum inhibitory concentrations of various antifungal agents against Basidiomycetes clinical isolates].  

PubMed

The basidiomycete yeasts are often isolated from clinical samples. A minimal inhibiting concentrations (MIC) of ten antifungals of different groups--azols, allilamines, polyens etc.--against isolates of Rhodotorula, Cryptococcus [symbol: see text] Trichosporon yeasts genera were estimated. No one of these cultures was sensitive to azoles at concentrations 0-256 mcg/ml. A vitality of cultures after incubation during 10 days with antifungals was investigated. Miramistin was the most potent fungicidal agent against all cultures. PMID:12087724

Arzumanian, V G

2002-01-01

10

Activity of TDT 067 (Terbinafine in Transfersome) against Agents of Onychomycosis, as Determined by Minimum Inhibitory and Fungicidal Concentrations?  

PubMed Central

TDT 067 is a novel carrier-based dosage form (liquid spray) of 15 mg/ml of terbinafine in Transfersome that has been developed to deliver terbinafine to the nail bed to treat onychomycosis. In this study, we report the in vitro activities of TDT 067 against dermatophytes, compared with those of the Transfersome vehicle, naked terbinafine, and commercially available terbinafine (1%) spray. The MICs of TDT 067 and comparators against 25 clinical strains each of Trichophyton rubrum, T. mentagrophytes, and Epidermophyton floccosum were determined according to the CLSI M38–A2 susceptibility method (2008). Minimum fungicidal concentrations (MFCs) were determined by subculturing visibly clear wells from the MIC microtiter plates. TDT 067 demonstrated potent activity against the dermatophyte strains tested, with an MIC range of 0.00003 to 0.015 ?g/ml. Overall, TDT 067 MIC50 values (defined as the lowest concentrations to inhibit 50% of the strains tested) were 8-fold and 60-fold lower than those of naked terbinafine and terbinafine spray, respectively. The Transfersome vehicle showed minimal inhibitory activity. TDT 067 demonstrated lower MFC values for T. rubrum and E. floccosum than naked terbinafine and terbinafine spray. TDT 067 has more potent antifungal activity against dermatophytes that cause nail infection than conventional terbinafine preparations. The Transfersome vehicle appears to potentiate the antifungal activity of terbinafine. Clinical investigation of TDT 067 for the topical treatment of onychomycosis is warranted.

Ghannoum, Mahmoud; Isham, Nancy; Herbert, Jacqueline; Henry, William; Yurdakul, Sam

2011-01-01

11

Comparison of Two Disc Diffusion Methods with Minimum Inhibitory Concentration for Antimicrobial Susceptibility Testing of Neisseria Gonorrhoeae Isolates  

PubMed Central

Background: A few studies are available comparing either minimum inhibitory concentration (MIC) values with the Clinical and Laboratory Standards Institute (CLSI) disc diffusion method or MIC with the Australian Gonococcal Surveillance Program (AGSP) method. Aim: This study was conducted with the aim to identify the most feasible and cost-effective method for antimicrobial susceptibility testing of Neisseria gonorrhoeae. Materials and Methods: Antimicrobial susceptibility testing of N. gonorrhoeae was performed using, in parallel, the E-test for MIC determination and disc diffusion by CLSI and AGSP techniques, and were compared. Susceptibility to penicillin, ciprofloxacin, tetracycline, ceftriaxone and spectinomycin and cefixime were determined by CSLI and AGSP method and Kappa statistics used to analyse the data with SPSS software. Results: All isolates were susceptible to ceftriaxone and spectinomycin by three methods. Ninety-nine (99%) strains were resistant to ciprofloxacin, while 1% showed intermediate susceptibility to ciprofloxacin by all methods. Statistically, there was a moderate level of agreement between the methods for penicillin. Conclusion: All three methods gave reproducible results. Although the media used in the disc diffusion by the AGSP method is easy and cheap to prepare, the CLSI method of disc diffusion testing is recommended for susceptibility testing of gonococcal isolates because of its feasibility and 100% accuracy, with MIC by E-test as the reference method.

Khaki, P; Sharma, A; Bhalla, P

2014-01-01

12

High vancomycin minimum inhibitory concentrations with heteroresistant vancomycin-intermediate Staphylococcus aureus in meticillin-resistant S. aureus bacteraemia patients.  

PubMed

Patients with high vancomycin minimum inhibitory concentrations (MICs) and heteroresistant vancomycin-intermediate Staphylococcus aureus (hVISA) infection are associated with treatment failure and poor outcomes. The main purpose of this study was to investigate the effect of hVISA on patient outcome, considering both the high vancomycin MIC and the existence of heteroresistant phenotypes. From January 2005 to December 2009, consecutive meticillin-resistant S. aureus (MRSA) isolates from 284 cases of MRSA bacteraemia receiving glycopeptide therapy were collected for further MIC and hVISA testing. The demographic distribution, clinical features and outcomes in bacteraemia patients with different vancomycin MICs and hVISA status in MRSA isolates were subsequently compared. Subjects were divided into three groups: low vancomycin MIC (<1.5mg/L) with vancomycin-sensitive S. aureus (VSSA) (n=50); high vancomycin MIC (?1.5mg/L) with VSSA (n=218); and high vancomycin MIC with hVISA (n=16). Cox regression analysis demonstrated that the high MIC with VSSA group exhibited significantly higher 30-day mortality than the low MIC with VSSA group [odds ratio (OR)=2.349, 95% confidence interval (CI) 1.078-5.118]. The high MIC with hVISA phenotype was not associated with higher mortality but was independently associated with persistent MRSA bacteraemia (OR=5.996, 95% CI 1.438-25.005). To summarise, although hVISA is correlated with persistent bacteraemia, higher mortality in high vancomycin MIC infections could not be explained by the existing hVISA phenotype. Facing persistent bacteraemia under glycopeptide therapy for 7 days, clinicians should consider shifting to an alternative class of antibiotics to treat hVISA infection. PMID:24041465

Wang, Jiun-Ling; Lai, Chung-Hsu; Lin, Hsi-Hsun; Chen, Wei-Fang; Shih, Yi-Chun; Hung, Chih-Hsin

2013-11-01

13

Linezolid minimum inhibitory concentration (MIC) creep in methicillin-resistant Staphylococcus aureus (MRSA) clinical isolates at a single Japanese center.  

PubMed

The aim of this study was to evaluate whether linezolid minimum inhibitory concentration (MIC) creep occurred in Staphylococcus aureus clinical isolates, including methicillin-resistant S. aureus (MRSA), over a recent 5-year period at a single Japanese center. A total of 453 MRSA and 195 methicillin-susceptible S. aureus (MSSA) isolates recovered from inpatients from April 1, 2008 to March 31, 2013 were analyzed. The MIC of linezolid was determined by automated Vitek-2 system. The modal MIC, MIC range, MIC50 and MIC90 (MICs required to inhibit the growth of 50% and 90% of organisms, respectively), geometric mean MIC and percentages of susceptible and resistant isolates were evaluated for each fiscal year. None of the S. aureus isolates were resistant to linezolid. Isolates with an MIC of >1 µg/mL were more common in the MSSA samples than in the MRSA samples (91.3% versus 38.2%, p<0.001). The linezolid geometric mean MIC increased by 0.403 µg/mL (from 1.178 in 2008 to 1.582 in 2012) in the MRSA isolates (p=0.006, r(2)=0.945 according to a linear regression analysis) over the 5-year period; however, no increase was observed in the MSSA isolates. The frequency of MRSA isolates with an MIC of 1 µg/mL decreased (from 76.3% in 2008 to 35.4% in 2012) and the isolates with MICs of >1 µg/mL increased over time (from 23.7% in 2008 to 64.6% in 2012). This report demonstrates the occurrence of linezolid MIC creep, as determined using the geometric mean MIC, in MRSA clinical isolates at a single Japanese center. PMID:24694615

Miyazaki, Motoyasu; Nagata, Nobuhiko; Miyazaki, Hiroyuki; Matsuo, Koichi; Takata, Tohru; Tanihara, Shinichi; Kamimura, Hidetoshi

2014-01-01

14

Increasing Echinocandin Resistance in Candida glabrata: Clinical Failure Correlates With Presence of FKS Mutations and Elevated Minimum Inhibitory Concentrations  

PubMed Central

Background.?Fluconazole (FLC) resistance is common in C. glabrata and echinocandins are often used as first-line therapy. Resistance to echinocandin therapy has been associated with FKS1 and FKS2 gene alterations. Methods.?We reviewed records of all patients with C. glabrata bloodstream infection at Duke Hospital over the past decade (2001–2010) and correlated treatment outcome with minimum inhibitory concentration (MIC) results and the presence of FKS gene mutations. For each isolate, MICs to FLC and echinocandins (anidulafungin, caspofungin, and micafungin) and FKS1 and FKS2 gene sequences were determined. Results.?Two hundred ninety-three episodes (313 isolates) of C. glabrata bloodstream infection were analyzed. Resistance to echinocandins increased from 4.9% to 12.3% and to FLC from 18% to 30% between 2001 and 2010, respectively. Among the 78 FLC resistant isolates, 14.1% were resistant to 1 or more echinocandin. Twenty-five (7.9%) isolates harbored a FKS mutation. The predictor of a FKS mutant strain was prior echinocandin therapy (stepwise multivariable analysis, odds ratio, 19.647 [95% confidence interval, 7.19–58.1]). Eighty percent (8/10) of patients infected with FKS mutants demonstrating intermediate or resistant MICs to an echinocandin and treated with an echinocandin failed to respond or responded initially but experienced a recurrence. Conclusions.?Echinocandin resistance is increasing, including among FLC-resistant isolates. The new Clinical and Laboratory Standards Institute clinical breakpoints differentiate wild-type from C. glabrata strains bearing clinically significant FKS1/FKS2 mutations. These observations underscore the importance of knowing the local epidemiology and resistance patterns for Candida within institutions and susceptibility testing of echinocandins for C. glabrata to guide therapeutic decision making.

Alexander, Barbara D.; Johnson, Melissa D.; Pfeiffer, Christopher D.; Jimenez-Ortigosa, Cristina; Catania, Jelena; Booker, Rachel; Castanheira, Mariana; Messer, Shawn A.; Perlin, David S.; Pfaller, Michael A.

2013-01-01

15

High vancomycin minimum inhibitory concentration is a predictor of mortality in meticillin-resistant Staphylococcus aureus bacteraemia.  

PubMed

Failure of vancomycin in the treatment of meticillin-resistant Staphylococcus aureus (MRSA) bacteraemia has been reported despite full susceptibility of the organism to vancomycin. A retrospective observational cohort study including 137 patients with MRSA bacteraemia was performed at two centres in South Korea during 2009-2010. A total of 137 patients with MRSA bacteraemia receiving vancomycin therapy were enrolled during the study period. Isolates from 13 (9.5%) of the 137 patients had minimum inhibitory concentrations (MICs) ?1 ?g/mL. The 30-day cumulative survival was 53.8% for patients infected with isolates having a MIC?1 ?g/mL and 79.8% for patients infected with isolates having a MIC<1 ?g/mL (log-rank test, P=0.026). Vancomycin MIC?1 ?g/mL [hazard ratio (HR)=7.0, 95% confidence interval (CI) 2.2-22.1; P=0.001], nosocomial acquisition of bacteraemia (HR=5.4, 95% CI 1.4-20.1; P=0.013), rapidly fatal underlying diseases (HR=20.5, 95% CI 3.9-106.4; P<0.001), presentation with septic shock (HR=8.4, 95% CI 3.0-23.3; P<0.001), presence of complicated infections (HR=5.6, 95% CI 2.0-15.8; P=0.001) and persistent MRSA bacteraemia for ?3 days (HR=4.2, 95% CI 1.4-12.7; P=0.012) were independent predictors of 30-day mortality in patients with MRSA bacteraemia. In patients with high Pitt bacteraemia scores (Pitt score ?2), the delay in initiation of vancomycin therapy was significantly different between non-survivors and survivors (2.4 days vs. 1.1 days; P=0.012). Vancomycin MIC?1 ?g/mL had a significant impact on mortality of patients with MRSA bacteraemia. These findings support early consideration of alternative anti-MRSA agents in patients with MRSA bacteraemia who have high vancomycin MICs as well as prompt initiation of anti-MRSA treatment in patients with MRSA bacteraemia, especially those with high Pitt scores. PMID:22633565

Wi, Yu Mi; Kim, June Myung; Joo, Eun-Jeong; Ha, Young Eun; Kang, Cheol-In; Ko, Kwan Soo; Chung, Doo Ryeon; Song, Jae-Hoon; Peck, Kyong Ran

2012-08-01

16

Effects of sub-minimum inhibitory concentration antibiotic levels and temperature on growth kinetics and outer membrane protein expression in Mannheimia haemolytica and Haemophilus somnus  

PubMed Central

Abstract The objective of this study was to determine the effects of sub-minimum inhibitory concentrations (sub-MICs) of 2 veterinary antibiotic preparations, chlortetracycline (CTC) and chlortetracycline-sulfamethazine (CTC + SMZ), on growth kinetics and outer membrane protein expression in Mannheimia haemolytica and Haemophilus somnus at normal and febrile body temperatures. Sub-minimum inhibitory concentrations of both antibiotics reduced the growth rates of M. haemolytica and H. somnus. Growth of both species was not inhibited when grown at 41°C compared to 37°C. There was no detectable consistent effect of antibiotic or temperature on outer membrane protein expression for either species. Our study indicates that sub-MIC levels of CTC and CTC + SMZ markedly impair growth of clinical M. haemolytica and H. somnus isolates, potentially allowing more effective host clearance during infection.

2005-01-01

17

Clinical characteristics of vancomycin minimum inhibitory concentration of 2 ?g\\/ml methicillin-resistant Staphylococcus aureus strains isolated from patients with bacteremia  

Microsoft Academic Search

Recent studies demonstrated that mortality associated with methicillin-resistant Staphylococcus aureus (MRSA) bacteremia was high when vancomycin was used to treat infections with strains that had a high vancomycin minimum inhibitory\\u000a concentration (MIC). This study compared several characteristics of vancomycin MIC 2 ?g\\/ml strains isolated from bacteremia\\u000a with those isolated from infections other than bacteremia. A total of 128 episodes of MRSA

Kazuhiko Nakajima; Yoshiko Takahashi; Kaori Ichiki; Mika Ishihara; Yasunao Wada; Toshie Tsuchida; Motoi Uchino; Hiroki Ikeuchi

2011-01-01

18

Area under the concentration-time curve to minimum inhibitory concentration ratio as a predictor of vancomycin treatment outcome in methicillin-resistant Staphylococcus aureus bacteraemia.  

PubMed

There have been few clinical studies on the association between the 24-h area under the concentration-time curve (AUC24) to minimum inhibitory concentration (MIC) ratio and vancomycin treatment outcomes in methicillin-resistant Staphylococcus aureus (MRSA) infections. Patients with MRSA bacteraemia between July 2009 and January 2012 were analysed retrospectively. All adult patients treated with vancomycin for ?72 h without dialysis were included. The MIC was determined by Etest and broth microdilution (BMD). Initial steady-state AUC24 was estimated using a Bayesian model, and the AUC24/MIC cut-off value for differentiating treatment success and failure was calculated by classification and regression tree (CART) analysis. In total, 76 patients were enrolled; vancomycin treatment failure occurred in 20 patients (26.3%). Catheter-related infection was the most frequent (35.5%), followed by surgical site infection (26.3%), whilst 25 (32.9%) had complicated infections. In univariate analysis, decreased MRSA vancomycin susceptibility (MIC?1.5 mg/L) and vancomycin trough levels (15-20 mg/L) were not associated with treatment outcomes. In the CART analysis, low initial vancomycin AUC24/MIC (<430 by Etest; <398.5 by BMD) was associated with a higher treatment failure rate (50.0% vs. 25.0%, P=0.039 by Etest; 45.0% vs. 23.2%; P=0.065 by BMD). In multivariate analysis, low initial vancomycin AUC24/MIC was a significant risk factor for treatment failure [adjusted odds ratio (aOR)=4.39, 95% confidence interval (CI), 1.26-15.35 by Etest; aOR=3.73, 95% CI 1.10-12.61 by BMD]. In MRSA bacteraemia, a low initial vancomycin AUC24/MIC is an independent risk factor for vancomycin treatment failure. PMID:24315788

Jung, Younghee; Song, Kyoung-Ho; Cho, Jeong eun; Kim, Hyung-sook; Kim, Nak-Hyun; Kim, Taek Soo; Choe, Pyoeng Gyun; Chung, Jae-Yong; Park, Wan Beom; Bang, Ji Hwan; Kim, Eu Suk; Park, Kyoung Un; Park, Sang-Won; Kim, Hong Bin; Kim, Nam Joong; Oh, Myoung-don

2014-02-01

19

Minimum inhibitory (MIC) and minimum microbicidal concentration (MMC) of polihexanide and triclosan against antibiotic sensitive and resistant Staphylococcus aureus and Escherichia coli strains.  

PubMed

Background: An in-vitro study was conducted investigating the antimicrobial efficacy of polihexanide and triclosan against clinical isolates and reference laboratory strains of Staphylococcus aureus and Escherichia coli.Methods: The minimal inhibitory concentration (MIC) and the minimal microbicidal concentration (MMC) were determined following DIN 58940-81 using a micro-dilution assay and a quantitative suspension test following EN 1040. Polihexanide was tested in polyethylene glycol 4000, triclosan in aqueous solutions.Results: Against all tested strains the MIC of polihexanide ranged between 1-2 µg/mL. For triclosan the MICs varied depending on strains ranging between 0.5 µg/mL for the reference strains and 64 µg/mL for two clinical isolates. A logRF >5 without and logRF >3 with 0.2% albumin burden was achieved at 0.6 µg/mL triclosan. One exception was S. aureus strain H-5-24, where a triclosan concentration of 0.6 µg/mL required 1 minute without and 10 minutes with albumin burden to achieve the same logRFs. Polihexanide achieved a logRF >5 without and logRF >3 with albumin burden at a concentration of 0.6 µg/mL within 30 sec. The exception was the North-German epidemic MRSA strain, were an application time of 5 minutes was required. Conclusion: The clinical isolates of E. coli generally showed higher MICs against triclosan, both in the micro-dilution assay as well in the quantitative suspension test than comparable reference laboratory strains. For polihexanide and triclosan strain dependant susceptibility was shown. However, both antimicrobial compounds are effective when used in concentrations common in practice. PMID:22242087

Assadian, Ojan; Wehse, Katrin; Hübner, Nils-Olaf; Koburger, Torsten; Bagel, Simone; Jethon, Frank; Kramer, Axel

2011-01-01

20

Minimum inhibitory (MIC) and minimum microbicidal concentration (MMC) of polihexanide and triclosan against antibiotic sensitive and resistant Staphylococcus aureus and Escherichia coli strains  

PubMed Central

Background: An in-vitro study was conducted investigating the antimicrobial efficacy of polihexanide and triclosan against clinical isolates and reference laboratory strains of Staphylococcus aureus and Escherichia coli. Methods: The minimal inhibitory concentration (MIC) and the minimal microbicidal concentration (MMC) were determined following DIN 58940-81 using a micro-dilution assay and a quantitative suspension test following EN 1040. Polihexanide was tested in polyethylene glycol 4000, triclosan in aqueous solutions. Results: Against all tested strains the MIC of polihexanide ranged between 1–2 µg/mL. For triclosan the MICs varied depending on strains ranging between 0.5 µg/mL for the reference strains and 64 µg/mL for two clinical isolates. A logRF >5 without and logRF >3 with 0.2% albumin burden was achieved at 0.6 µg/mL triclosan. One exception was S. aureus strain H-5-24, where a triclosan concentration of 0.6 µg/mL required 1 minute without and 10 minutes with albumin burden to achieve the same logRFs. Polihexanide achieved a logRF >5 without and logRF >3 with albumin burden at a concentration of 0.6 µg/mL within 30 sec. The exception was the North-German epidemic MRSA strain, were an application time of 5 minutes was required. Conclusion: The clinical isolates of E. coli generally showed higher MICs against triclosan, both in the micro-dilution assay as well in the quantitative suspension test than comparable reference laboratory strains. For polihexanide and triclosan strain dependant susceptibility was shown. However, both antimicrobial compounds are effective when used in concentrations common in practice.

Assadian, Ojan; Wehse, Katrin; Hubner, Nils-Olaf; Koburger, Torsten; Bagel, Simone; Jethon, Frank; Kramer, Axel

2011-01-01

21

Bacterial Resistance Studies Using In Vitro Dynamic Models: the Predictive Power of the Mutant Prevention and Minimum Inhibitory Antibiotic Concentrations  

PubMed Central

In light of the concept of the mutant selection window, i.e., the range between the MIC and the mutant prevention concentration (MPC), MPC-related pharmacokinetic indices should be more predictive of bacterial resistance than the respective MIC-related indices. However, experimental evidence of this hypothesis remains limited and contradictory. To examine the predictive power of the ratios of the area under the curve (AUC24) to the MPC and the MIC, the selection of ciprofloxacin-resistant mutants of four Escherichia coli strains with different MPC/MIC ratios was studied. Each organism was exposed to twice-daily ciprofloxacin for 3 days at AUC24/MIC ratios that provide peak antibiotic concentrations close to the MIC, between the MIC and the MPC, and above the MPC. Resistant E. coli was intensively enriched at AUC24/MPCs from 1 to 10 h (AUC24/MIC from 60 to 360 h) but not at the lower or higher AUC24/MPC and AUC24/MIC ratios. AUC24/MPC and AUC24/MIC relationships of the areas under the time courses of ciprofloxacin-resistant E. coli (AUBCM) were bell-shaped. A Gaussian-like function fits the AUBCM-AUC24/MPC and AUBCM-AUC24/MIC data combined for all organisms (r2 = 0.69 and 0.86, respectively). The predicted anti-mutant AUC24/MPC ratio was 58 ± 35 h, and the respective AUC24/MIC ratio was 1,080 ± 416 h. Although AUC24/MPC was less predictive of strain-independent E. coli resistance than AUC24/MIC, the established anti-mutant AUC24/MPC ratio was closer to values reported for Staphylococcus aureus (60 to 69 h) than the respective AUC24/MIC ratio (1,080 versus 200 to 240 h). This implies that AUC24/MPC might be a better interspecies predictor of bacterial resistance than AUC24/MIC.

Strukova, Elena N.; Shlykova, Darya S.; Portnoy, Yury A.; Kozyreva, Varvara K.; Edelstein, Mikhail V.; Dovzhenko, Svetlana A.; Kobrin, Mikhail B.; Zinner, Stephen H.

2013-01-01

22

Prognosis of patients with methicillin-resistant Staphylococcus aureus bloodstream infection treated with teicoplanin: a retrospective cohort study investigating effect of teicoplanin minimum inhibitory concentrations  

PubMed Central

Background The present study was designed to investigate whether teicoplanin minimum inhibitory concentrations (MICs) of methicillin-resistant Staphylococcus aureus (MRSA) isolates play a role in the prognosis of patient with teicoplanin-treated MRSA bloodstream infection (BSI). Methods Between 1 January 2006 and 31 December 2009, adult patients with teicoplanin-treated MRSA BSI in two Taiwan medical centers were retrospectively enrolled. Their blood MRSA isolates were submitted for determination of MICs to various antibiotics and multi-locus sequence types. All-cause mortalities on Days 14 and 30, as well as clinical response at the end of teicoplanin therapy were treated as endpoints. Results Two hundred seventy adult patients were enrolled and 210 blood MRSA isolates were available. Independent risk factors for un-favorable outcome at the end of teicoplanin therapy included septic shock (p?

2013-01-01

23

Bactericidal activity of daptomycin versus vancomycin in the presence of human albumin against vancomycin-susceptible but tolerant methicillin-resistant Staphylococcus aureus (MRSA) with daptomycin minimum inhibitory concentrations of 1–2 ?g\\/mL  

Microsoft Academic Search

This study explored the influence of vancomycin tolerance and protein binding on the bactericidal activity of vancomycin versus daptomycin (protein binding 36.9% vs. 91.7%, respectively) against four vancomycin-tolerant methicillin-resistant Staphylococcus aureus (MRSA) [minimum inhibitory concentration\\/minimum bactericidal concentration (MIC\\/MBC)=0.5\\/16, 1\\/32, 2\\/32 and 1\\/32?g\\/mL for vancomycin and 1\\/1, 1\\/2, 2\\/2 and 2\\/4?g\\/mL for daptomycin]. Killing curves were performed with vancomycin\\/daptomycin concentrations equal

M. Torrico; M. J. Giménez; N. González; L. Alou; D. Sevillano; F. Cafini; J. Prieto; R. Cleeland; L. Aguilar

2010-01-01

24

Vancomycin versus daptomycin for the treatment of methicillin-resistant Staphylococcus aureus bacteremia due to isolates with high vancomycin minimum inhibitory concentrations: study protocol for a phase IIB randomized controlled trial  

PubMed Central

Background Vancomycin is the standard first-line treatment for methicillin-resistant Staphylococcus aureus bacteremia. However, recent consensus guidelines recommend that clinicians consider using alternative agents such as daptomycin when the vancomycin minimum inhibitory concentration is greater than 1 ug/ml. To date however, there have been no head-to-head randomized trials comparing the safety and efficacy of daptomycin and vancomycin in the treatment of such infections. The primary aim of our study is to compare the efficacy of daptomycin versus vancomycin in the treatment of bloodstream infections due to methicillin-resistant Staphylococcus aureus isolates with high vancomycin minimum inhibitory concentrations (greater than or equal to 1.5 ug/ml) in terms of reducing all-cause 60-day mortality. Methods/Design The study is designed as a multicenter prospective open label phase IIB pilot randomized controlled trial. Eligible participants will be inpatients over 21-years-old with a positive blood culture for methicillin-resistant Staphylococcus aureus with vancomycin minimum inhibitory concentration of greater than or equal to 1.5ug/ml. Randomization into intervention or active control arms will be performed with a 1:1 allocation ratio. We aim to recruit 50 participants over a period of two years. Participants randomized to the active control arm will receive vancomycin dose-while those randomized to the intervention arm will receive daptomycin. Participants will receive a minimum of 14 days study treatment. The primary analysis will be conducted on the intention-to-treat principle. The Fisher’s exact test will be used to compare the 60-day mortality rate from index blood cultures (primary endpoint) between the two treatment arms, and the exact two-sided 95% confidence interval will be calculated using the Clopper and Pearson method. Primary analysis will be conducted using a two sided alpha of 0.05. Discussion If results from this pilot study suggest that daptomycin shows significant efficacy in the treatment of bloodstream infections due to methicillin-resistant Staphylococcus aureus isolates with high vancomycin minimum inhibitory concentrations, we aim to proceed with a larger scale confirmatory study. This would help guide clinicians and inform practice guidelines on the optimal treatment for such infections. Trial registration The trial is listed on clinicaltrials.gov (NCT01975662, date of registration: 29 October 2013).

2014-01-01

25

Bactericidal activity of daptomycin versus vancomycin in the presence of human albumin against vancomycin-susceptible but tolerant methicillin-resistant Staphylococcus aureus (MRSA) with daptomycin minimum inhibitory concentrations of 1-2microg/mL.  

PubMed

This study explored the influence of vancomycin tolerance and protein binding on the bactericidal activity of vancomycin versus daptomycin (protein binding 36.9% vs. 91.7%, respectively) against four vancomycin-tolerant methicillin-resistant Staphylococcus aureus (MRSA) [minimum inhibitory concentration/minimum bactericidal concentration (MIC/MBC)=0.5/16, 1/32, 2/32 and 1/32microg/mL for vancomycin and 1/1, 1/2, 2/2 and 2/4microg/mL for daptomycin]. Killing curves were performed with vancomycin/daptomycin concentrations equal to serum peak concentrations (C(max)) (65.70/98.60microg/mL) and trough concentrations (C(min)) (7.90/9.13microg/mL) in the presence and absence of a physiological human albumin concentration (4g/dL), controlled with curves with the theoretical free drug fraction of vancomycin/daptomycin C(max) (41.45/8.18microg/mL) and C(min) (4.98/0.76microg/mL). Vancomycin C(max) and C(min) concentrations, regardless of the media, showed a bacteriostatic profile not reaching a reduction of 99% or 99.9% of the initial inocula during the 24-h experimental time period. Daptomycin antibacterial profiles significantly differed when testing C(max) and C(min). C(max) was rapidly bactericidal (< or =4h) with >5 log(10) reduction in the initial inocula for all strains, regardless of the presence or not of albumin or the use of concentrations similar to free C(max). C(min) exhibited similar final colony counts at 0h and 24h in curves with albumin, but with >3 log colony-forming units (CFU)/mL reduction at < or =4h for strains with an MIC of 1microg/mL and ca. 2 logCFU/mL reduction at < or =6h for strains with an MIC of 2microg/mL. This activity was significantly higher than the activity of the free C(min) fraction. The results of this study reinforce the idea that pharmacodynamics using concentrations calculated using reported protein binding are unreliable. Daptomycin exhibited rapid antibacterial activity against vancomycin-tolerant MRSA isolates even against those with high daptomycin MICs in the presence of physiological albumin concentrations. PMID:20006469

Torrico, M; Giménez, M J; González, N; Alou, L; Sevillano, D; Cafini, F; Prieto, J; Cleeland, R; Aguilar, L

2010-02-01

26

Flammability limits of dusts: Minimum inerting concentrations  

SciTech Connect

A new flammability limit parameter has been defined as the Minimum Inerting Concentration (MIC). This is the concentration of inertant required to prevent a dust explosion regardless of fuel concentration. Previous experimental work at Fike in a 1-m{sup 3} spherical chamber has shown this flammability limit to exist for pulverized coal dust and cornstarch. In the current work, inerting experiments with aluminum, anthraquinone and polyethylene dusts as fuels were performed, using monoammonium phosphate and sodium bicarbonate as inertants. The results show that an MIC exists only for anthraquinone inerted with sodium bicarbonate. The other combustible dust and inertant mixtures did not show a definitive MIC, although they did show a strong dependence between inerting level and suspended fuel concentration. As the fuel concentration increased, the amount of inertant required to prevent an explosion decreased. Even though a definitive MIC was not found for most of the dusts an effective MIC can be estimated from the data. The use of MIC data can aid in the design of explosion suppression schemes.

Dastidar, A.G.; Amyotte, P.R. [Dalhousie Univ., Halifax, Nova Scotia (Canada). Dept. of Chemical Engineering] [Dalhousie Univ., Halifax, Nova Scotia (Canada). Dept. of Chemical Engineering; Going, J.; Chatrathi, K. [Fike Corp., Blue Springs, MO (United States)] [Fike Corp., Blue Springs, MO (United States)

1999-05-01

27

Effect of sub-minimum inhibitory concentrations of ciprofloxacin, amikacin and colistin on biofilm formation and virulence factors of Escherichia coli planktonic and biofilm forms isolated from human urine  

PubMed Central

The aim of this study was to determine the effect of subinhibitory concentrations (sub-MICs) of ciprofloxacin, amikacin and colistin on biofilm formation, motility, curli fimbriae formation by planktonic and biofilm cells of E. coli strains isolated from the urine of patients with various urinary system infections. Quantification of biofilm formation was carried out using a microtiter plate assay and a spectrophotometric method. Bacterial enumeration was used to assess the viability of bacteria in the biofilm. Curli expression was determined by using YESCA agar supplemented with congo red. Using motility agar the ability to move was examined. All the antibiotics used at sub-MICs reduced biofilm formation in vitro, decreased the survival of bacteria, but had no effect on the motility of planktonic as well as biofilm cells. The inhibitory effect of sub-MICs of antimicrobial agents on curli fimbriae formation was dependent on the form in which the bacteria occurred, incubation time and antibiotic used. Our results clearly show that all the three antibiotics tested reduce biofilm production, interfere with curli expression but do not influence motility. This study suggests that ciprofloxacin, amikacin and colistin may be useful in the treatment of biofilm-associated infections caused by E. coli strains.

Wojnicz, Dorota; Tichaczek-Goska, Dorota

2013-01-01

28

The effects of subminimal inhibitory concentrations of beta-lactam antibiotics against Clostridium perfringens.  

PubMed

The effects of subminimal inhibitory concentrations (sub-MIC) of four beta-lactam antibiotics [penicillin-G (PCG), ampicillin (AMP), cephaloridine (CER), cephalothin (CET)] were tested against Clostridium perfringens type A PB6K, after determining the minimum inhibitory concentrations (MIC) of 29 different Clostridium strains. The majority of the strains were sensitive to all beta-lactam antibiotics. Morphological changes, such as filamentous development and lysis, occurred at concentrations considerably lower than the MIC of CER and CET in C. perfringens. Clear cooperation of AMP and CER with rabbit polymorphonuclear leucocytes (PMNL) against C. perfringens was observed. The filamentous bacteria produced as a result of exposure to sub-MIC of each antibiotic, were phagocytosed easily. The ratios between the drug concentrations (microg/ml) at which the morphological changes began to occur, the minimum antibiotic concentrations (MAC), and the MIC values (microg/ml), were calculated. A large ratio indicated a wide range of effective concentrations below the MIC value for the antibiotics. PMID:11414501

Kondo, F; Kuroki, H

2001-01-01

29

No evidence of vancomycin minimal inhibitory concentration creep or heteroresistance identified in pediatric Staphylococcus aureus blood isolates.  

PubMed

We evaluated vancomycin minimum inhibitory concentration (MIC) trends by 3 methods (broth microdilution, Etest and Vitek 2) in 208 Staphylococcus aureus blood isolates from 2006 to 2009 and assessed for heteroresistance. Vancomycin MICs did not increase nor was heteroresistance identified. Etest yielded higher MIC results than the other 2 methods. No MIC was >2 µg/mL by any testing method. PMID:24413409

Goldman, Jennifer L; Harrison, Christopher J; Myers, Angela L; Jackson, Mary Anne; Selvarangan, Rangaraj

2014-02-01

30

Spacecraft Minimum Allowable Concentrations: Determination, Application, and Contingency Situations  

NASA Technical Reports Server (NTRS)

This document is an outline of a presentation about the determination of minimum allowable concentrations in spacecraft. The presentation reviews the type of toxins and mechanisms to determine the acceptable concentrations of these toxic substances. The considerations for the unique situation that spaceflight entails including zero gravity, and the intense scrutiny are reviewed. The current measurement hardware is reviewed. The spacecraft atmospheres on the Shuttle, airflow, the Space Station and the EMU in respect to airflow, pressure, constituents are also summarized. Contingency situations and potential hazards are also discussed.

Marshburn, Thomas H.; Dawson, David L. (Technical Monitor)

1999-01-01

31

Focal Heat Stimulation for the Determination of the Minimum Alveolar Concentration of Halothane in the Rabbit  

Microsoft Academic Search

Sobair, A.T.H., Cottrell, D.F. and Camburn, M.A., 1997. Focal heat stimulation for the determination of the minimum alveolar concentration of halothane in the rabbit. Veterinary Research Communications, 21 (3), 149-159

A. T. H. Sobair; D. F. Cottrell; M. A. Camburn

1997-01-01

32

Minimum detectable concentration as a function of gamma walkover survey technique.  

PubMed

Gamma walkover surveys are often performed by swinging the radiation detector (e.g., a 2-inch by 2-inch sodium iodide) in a serpentine pattern at a near constant height above the ground surface. The objective is to survey an approximate 1-m swath with 100% coverage producing an equal probability of detecting contamination at any point along the swing. In reality, however, the detector height will vary slightly along the swing path, and in some cases the detector may follow a pendulum-like motion significantly reducing the detector response and increasing the minimum detectable concentration. This paper quantifies relative detector responses for fixed and variable height swing patterns and demonstrates negative impacts on the minimum detectable concentration. Minimum detectable concentrations are calculated for multiple contaminated surface areas (0.1, 1.0, 3, 10, and 30 m2), multiple contaminants (60Co, 137Cs, 241Am, and 226Ra), and two minimum heights (5 and 10 cm). Exposure rate estimates used in minimum detectable concentration calculations are produced using MicroShield™ v.7.02 (Grove Software, Inc., 4925 Boonsboro Road #257, Lynchberg, VA 24503) and MDCs are calculated as outlined in NUREG-1575. Results confirm a pendulum-like detector motion can significantly increase MDCs relative to a low flat trajectory, especially for small areas of elevated activity--up to a 47% difference is observed under worst-modeled conditions. PMID:22249469

King, David A; Altic, Nickolas; Greer, Colt

2012-02-01

33

Minimum inhibitory concentration (MIC) of some antibiotics against Vibrio cholerae O139 isolates from Pondicherry.  

PubMed

The antibiotic susceptibility pattern of Vibrio cholerae O139, Bengal, an emerging intestinal pathogen has been determined by the Kirby Bauer technique and the MIC values of some antibiotics against these strains by agar dilution technique. All the strains were susceptible to tetracycline, norfloxacin, ciprofloxacin and a majority was susceptible to gentamicin (95.7%) and nalidixic acid (82.9%). Only 51% were susceptible to cefotaxime and most strains were resistant to furazolidone (95.7%), ampicillin (87.3%) and co-trimoxazole (91.5%). The study shows the importance of judicious use of antibiotics in cholera cases and the need for monitoring the susceptibility status of these strains particularly because of their ability to cause extra-intestinal infections like septicaemia. PMID:9287939

Vijayalakshmi, N; Rao, R S; Badrinath, S

1997-08-01

34

Vancomycin minimum inhibitory concentration, host comorbidities and mortality in Staphylococcus aureus bacteraemia.  

PubMed

We reported an association between elevated vancomycin MIC and 30-day mortality in patients with Staphylococcus aureus bacteraemia (SAB), including patients with methicillin-susceptible S. aureus (MSSA) treated with flucloxacillin. A detailed analysis of comorbidities and disease severity scores in the same cohort of patients was performed to ascertain if unknown clinical parameters may have influenced these results. The association between elevated vancomycin MIC and 30-day mortality in SAB remained significant (p 0.001) on multivariable logistic regression analysis even when accounting for clinical factors. In addition, the association persisted when restricting analysis to patients with MSSA bacteraemia treated with flucloxacillin. This suggests that elevated vancomycin MIC is associated with but not causally linked to an organism factor that is responsible for increased mortality. PMID:23441652

Holmes, N E; Turnidge, J D; Munckhof, W J; Robinson, J O; Korman, T M; O'Sullivan, M V N; Anderson, T L; Roberts, S A; Warren, S J C; Gao, W; Johnson, P D R; Howden, B P

2013-12-01

35

Comparison of stress concentration versus minimum solid area based mechanical property-porosity relations  

Microsoft Academic Search

Stress concentrations due to pore shape are questioned as a fundamental determinant of mechanical property-porosity relations, especially elastic property porosity relations. On the other hand, actual solid load-bearing areas, especially minimum solid areas of porous bodies, clearly are a determinant of mechanical property-porosity effects. The correlation of pore shape-stress concentration effects with elastic properties of ceramics can be explained by

R. W. Rice; W. R. Grace

1993-01-01

36

Variability of immune response induced by bacteria treated with subminimal inhibitory concentrations of fosfomycin.  

PubMed

Experiments were conducted to explore the possibility that bacterial strains treated with subminimal inhibitory concentrations (sub-MICs) of fosfomycin might induce immune responses different from those induced by intact, untreated bacteria. A preliminary study was done with a strain of Salmonella wien. The immune response in rabbits immunized with bacteria that had been exposed to either the sub-MIC or the minimal inhibitory concentration (MIC) of fosfomycin was compared with that in rabbits immunized with S. wien not exposed to the drug. The titers of antibody to S. wien in rabbits immunized with abnormal, sub-MIC-treated bacteria were higher than those in rabbits immunized with either MIC-treated or untreated S. wien. This difference was seen not only with the total antigen of Salmonella but also with somatic (O) and flagellar (H) antigens. PMID:542762

Viano, I; Martinetto, P; Valtz, A; Santiano, M; Barbaro, S

1979-01-01

37

Radiative constraints on the minimum atomic oxygen concentration in the mesopause region  

NASA Astrophysics Data System (ADS)

Atomic oxygen [O] plays a fundamental role in the photochemistry and energy budget of the terrestrial mesopause region (80-100 km). [O] is difficult to measure directly and is typically inferred at night from measurements of hydroxyl [OH] or molecular oxygen [O2] emissions. During the day, measurements of ozone [O3] concentration are used to infer [O]. These inferences carry significant uncertainties [Mlynczak et al., 2013a]. Recently, Mlynczak et al. [2013b] have used energy balance principles to set an upper limit on the annual global mean [O] concentration in the mesopause region. In this paper, we use night measurements of OH emission to set a lower limit on the global annual mean atomic oxygen concentration. These independent, radiatively constrained values of the maximum and minimum atomic oxygen concentration also place constraints on the magnitude of dynamical processes in the annual global mean energy budget of the mesopause region.

Mlynczak, Martin G.; Hunt, Linda A.; Marshall, B. Thomas; Mertens, Christopher J.; Russell, James M.; Siskind, David; Thompson, R. Earl; Gordley, Larry L.

2013-07-01

38

Fumonisin concentration and ceramide synthase inhibitory activity of corn, masa, and tortilla chips.  

PubMed

Nixtamalization removes fumonisins from corn and reduces their amounts in masa and tortilla products. Fumonisin concentrations and potential toxicity could be underestimated, however, if unknown but biologically active fumonisins are present. Therefore, the relative amounts of fumonisins in extracts of fumonisin-contaminated corn and its masa and tortilla chip nixtamalization products were determined with an in vitro ceramide synthase inhibition bioassay using increased sphinganine (Sa) and sphinganine to sphingosine ratio (Sa/So) as endpoints. African green monkey kidney cells (Vero cells ATCC CCL-81) were grown in 1-ml wells and exposed to 4 microl of the concentrated extracts for 48 h. The corn extract inhibited ceramide synthase as Sa (mean = 132 pmol/well) and Sa/So (mean = 2.24) were high compared to vehicle controls (Sa = 9 pmol/well; Sa/So = 0.10). Inhibitory activity (mean Sa = 14-24 pmol/well; mean Sa/So = 0.17-0.28) of the masa and tortilla chip extracts were reduced > or = 80% compared to the corn extract. Results were corroborated in a second experiment in which Sa and Sa/So of the wells treated with masa or tortilla chip extracts were reduced > or = 89% compared to those treated with the corn extract. Masa and tortilla chip FB1 concentrations (4-7 ppm) were reduced about 80-90% compared to the corn (30 ppm) when the materials were analyzed by high-performance liquid chromatography (HPLC). Therefore, nixtamalization reduced both the measured amount of FB1 and the ceramide synthase inhibitory activity of masa and tortilla chips extracts. The results further suggest that the masa and tortilla chip extracts did not contain significant amounts of unknown fumonisins having ceramide synthase inhibitory activity. PMID:16760143

Voss, Kenneth A; Norred, William P; Meredith, Filmore I; Riley, Ronald T; Stephen Saunders, D

2006-07-01

39

Isolation of Neisseria meningitidis strains with increase of penicillin minimal inhibitory concentrations  

PubMed Central

We report the isolation and characterization of ten strains showing an increase in the minimal inhibitory concentrations to penicillin (MICs > 0·1 ?g/ml), and describe the epidemiological, clinical and microbiological features. The susceptibility of 3432 meningococcal strains isolated from patients in the recent epidemic wave (1978-86) in Spain, to several antimicrobial agents used in the treatment and chemoprophylaxis of meningococcal infection has been tested. Most were resistant to sulphadiazine but sensitive to other antibiotics. The possible existence of a new pattern of behaviour of meningococcal to penicillin is discussed.

Saez-Nieto, J. A.; Fontanals, D.; De Jalon, J. Garcia; De Artola, V. Martinez; Pena, P.; Morera, M. A.; Verdaguer, R.; Sanfeliu, I.; Belio-Blasco, C.; Perez-Saenz, J. L.; Casal, J.

1987-01-01

40

Technical basis for a minimum hydroxide concentration in tanks containing dilute waste  

SciTech Connect

Laboratory tests were performed to address the protection of waste tank steel from corrosion in situations of elevated temperatures up to 75 C (hot spots) in the sludge layer of Extended Sludge Processing (ESP) tanks. Coupon immersion tests were conducted at 75 C in two ESP simulants at four hydroxide (or pH) levels. The nitrite concentrations of the simulants were calculated from the ESP technical standards based on a temperature of 40 C. The results showed that a hydroxide concentration of at least 0.01 M prevented significant corrosion of the steel at the elevated temperature. This conclusion provides the technical basis for the revised minimum hydroxide concentration of 0.01 M in the draft WSRC 241-82H Control Room Process Requirements, for the ESP tanks.

Zapp, P.E.

1995-05-01

41

Free energy dissipation of the pyruvate kinase reaction has a minimum at cell metabolite concentrations.  

PubMed

The ratio of substrates and products (mass action ratio) for the reaction catalyzed by the enzyme pyruvate kinase is measured under the constraint of constant reaction rate for pyruvate kinase (EC 2.7.1.40) from brewers yeast and Escherichia coli. For both organisms, a maximum of the ratio is found at concentrations comparable to those obtained from cell metabolite measurements. This observation suggests an optimum principle for free energy transduction in the glycolytic reaction pathway, as a maximum of the mass action ratio corresponds to a minimum dissipation of free energy. PMID:6362733

Markus, M; Plesser, T

1983-11-01

42

Effect of subminimal inhibitory concentrations of azithromycin on adherence of Pseudomonas aeruginosa to polystyrene.  

PubMed

Pseudomonas aeruginosa forms a bacterial biofilm by producing alginate when it adheres to mucosa or various medical devices. In this study, the effect of subminimal inhibitory concentrations (subMICs) of azithromycin (AZM) on the biofilm formation and in vitro adherence to polystyrene of 14 wild-type P. aeruginosa strains was studied. A total of 35 P. aeruginosa isolates from clinical specimens were used. Glycocalyx production was determined by the tube method, and bacterial adherence to the wells of flat bottom polystyrene tissue culture plates was estimated by the spectrophotometric method. Compared to the control, the adherence ability to polystyrene was inhibited by incubation with subMICs of AZM in a dose-dependent manner. These results support the findings of other investigators suggesting that AZM in subinhibitory concentrations may be useful in the prevention or treatment of biofilm-associated infections due to P. aeruginosa. PMID:10949976

Vranes, J

2000-08-01

43

Wild-type minimal inhibitory concentration distributions in bacteria of animal origin in Argentina.  

PubMed

The aim of this study was to determine the antimicrobial resistance profiles of indicator bacteria isolated from domestic animal feces. Minimal inhibitory concentration (MIC) was determined by agar dilution. Interpretative criteria on the basis of wild-type MIC distributions and epidemiological cutoff values (ECOFF or ECV) were used according to the 'European Committee on Antimicrobial Susceptibility Testing' (EUCAST) data. Results from 237 isolates of Escherichia coli showed reduced susceptibility for ampicillin, streptomycin and tetracycline, the antimicrobials commonly used in intensive breeding of pigs and hens. Regarding all the species of the genus Enterococcus spp., there are only ECOFF or ECV for vancomycin. Of the 173 Enterococcus spp. isolated, only one showed reduced susceptibility to vancomycin and was classified as 'non-wild-type' (NWT) population. This is the first report in Argentina showing data of epidemiological cutoff values in animal bacteria. PMID:24721272

Pantozzi, Florencia L; Ibar, Mariela P; Nievas, Victorio F; Vigo, Germán B; Moredo, Fabiana A; Giacoboni, Gabriela I

2014-01-01

44

Calculation of Minimum-Detectable-Concentration Levels of Radioxenon Isotopes Using the PNNL ARSA System  

SciTech Connect

Measurement of xenon fission product isotopes is a key element in the global network being established to monitor the Comprehensive Nuclear-Test-Ban Treaty. The automated Radio-xenon Analyzer/Sampler (ARSA), built by Pacific Northwest National Laboratory, can detect 131mXe, 133mXe, 133Xe, and 135Xe via a beta-gamma counting system. Due to the variable background and sources of these four radio-xenon isotopes, it is important to have as sensitive a detection system as possible and to quantify the Minimum-Detectable-Concentrations (MDC) that such a system will be able to detect to preclude false negative and false positive results. From data obtained from IAR in Germany MDC values for 133Xe were well below the 1 mBq/SCMA as required by the PTS for the Comprehensive Test BAn Treaty [WGB TL-11,1999].

McIntyre, Justin I.; Bowyer, Ted W.; Reeder, Paul L.

2006-03-11

45

Inhaled anesthetics and immobility: mechanisms, mysteries, and minimum alveolar anesthetic concentration.  

PubMed

Studies using molecular modeling, genetic engineering, neurophysiology/pharmacology, and whole animals have advanced our understanding of where and how inhaled anesthetics act to produce immobility (minimum alveolar anesthetic concentration; MAC) by actions on the spinal cord. Numerous ligand- and voltage-gated channels might plausibly mediate MAC, and specific amino acid sites in certain receptors present likely candidates for mediation. However, in vivo studies to date suggest that several channels or receptors may not be mediators (e.g., gamma-aminobutyric acid A, acetylcholine, potassium, 5-hydroxytryptamine-3, opioids, and alpha(2)-adrenergic), whereas other receptors/channels (e.g., glycine, N-methyl-D-aspartate, and sodium) remain credible candidates. PMID:12933393

Sonner, James M; Antognini, Joseph F; Dutton, Robert C; Flood, Pamela; Gray, Andrew T; Harris, R Adron; Homanics, Gregg E; Kendig, Joan; Orser, Beverley; Raines, Douglas E; Rampil, Ira J; Trudell, James; Vissel, Bryce; Eger, Edmond I

2003-09-01

46

How partially inhibitory concentrations of chloramphenicol affect the growth of Escherichia coli.  

PubMed Central

In the presence of up to 6 microM chloramphenicol, balanced exponential growth of Escherichia coli occurred at a reduced rate after an adjustment period. The inhibition of ribosome function by chloramphenicol within growing cells was inferred from measurements of growth rate and cell composition during balanced growth and of pulse-labeling of cells by radioactive proline after a 10-min exposure to chloramphenicol. In each case the results were consistent with simple noncompetitive inhibition of protein synthesis, with 50% inhibition occurring at 2 microM chloramphenicol, the concentration that gave 50% binding of chloramphenicol to purified ribosomes in vitro. The differences between these results and those obtained with cell-free protein synthesizing systems were shown to be in part due to slow binding of chloramphenicol and in part due to the slow rate and lack of saturation of the cell-free protein-synthesizing systems now available. During balanced growth in concentrations of chloramphenicol 1 microM or higher, the net rate of maturation of ribosomal ribonucleic acid was also inhibited (50% at 2.8 microM). The specific growth rate during balanced growth was inhibited by 50% at 1.8 microM chloramphenicol, but at higher concentrations inhibition was greater than expected from the simple noncompetitive dose-response observed for inhibition of polypeptide synthesis. However, the inhibition of maturation of ribosomal ribonucleic acid plus the inhibition of protein synthesis quantitatively accounted for the observed inhibition of growth. Thus, we have presented for the first time an essentially complete account of the effects of partially inhibitory concentrations of an antibiotic on the growth physiology of a bacterium. Images

Harvey, R J; Koch, A L

1980-01-01

47

Sub-Inhibitory Concentrations of Trans-Cinnamaldehyde Attenuate Virulence in Cronobacter sakazakii in Vitro  

PubMed Central

Cronobacter sakazakii is a foodborne pathogen, which causes a life-threatening form of meningitis, necrotizing colitis and meningoencephalitis in neonates and children. Epidemiological studies implicate dried infant formula as the principal source of C. sakazakii. In this study, we investigated the efficacy of sub-inhibitory concentrations (SIC) of trans-cinnamaldehyde (TC), an ingredient in cinnamon, for reducing C. sakazakii virulence in vitro using cell culture, microscopy and gene expression assays. TC significantly (p ? 0.05) suppressed C. sakazakii adhesion to and invasion of human and rat intestinal epithelial cells, and human brain microvascular endothelial cells. In addition, TC inhibited C. sakazakii survival and replication in human macrophages. We also observed that TC reduced the ability of C. sakazakii to cause cell death in rat intestinal cells, by inhibiting nitric oxide production. Results from gene expression studies revealed that TC significantly downregulated the virulence genes critical for motility, host tissue adhesion and invasion, macrophage survival, and LPS (Lipopolysaccharide) synthesis in C. sakazakii. The efficacy of TC in attenuating these major virulence factors in C. sakazakii underscores its potential use in the prevention and/or control of infection caused by this pathogen.

Amalaradjou, Mary Anne Roshni; Kim, Kwang Sik; Venkitanarayanan, Kumar

2014-01-01

48

Lower macrophage migration inhibitory factor concentrations in maternal serum before pre-eclampsia onset.  

PubMed

Macrophage migration inhibitory factor (MIF) plays a pivotal role in pregnancy-related proinflammatory processes, such as placentation and labor. Differential MIF concentrations have been correlated with pathological events during pregnancy, such as recurrent miscarriages and severe pre-eclampsia (PE). The aim of this study was to prospectively investigate whether maternal MIF serum levels are already altered in early pregnancy before PE onset. Women (n=2,821) before 20 weeks of gestational age were recruited for a prospective study on early markers of PE. Forty-eight consecutive pregnancies that developed PE and 79 normotensive pregnancies that delivered at term were chosen. Maternal MIF serum levels were assessed by ELISA. We found significantly lower MIF serum levels in women who developed PE (4,967±3,119?pg/mL) compared to controls (7,640±5,519?pg/mL) (mean±standard deviation, P<0.001). Our findings indicate that low maternal MIF serum levels in early pregnancy may contribute to abnormal placental development. PMID:24606610

Cardaropoli, Simona; Ietta, Francesca; Romagnoli, Roberta; Rolfo, Alessandro; Paulesu, Luana; Todros, Tullia

2014-07-01

49

Sub-Inhibitory Concentrations of Trans-Cinnamaldehyde Attenuate Virulence in Cronobacter sakazakii in Vitro.  

PubMed

Cronobacter sakazakii is a foodborne pathogen, which causes a life-threatening form of meningitis, necrotizing colitis and meningoencephalitis in neonates and children. Epidemiological studies implicate dried infant formula as the principal source of C. sakazakii. In this study, we investigated the efficacy of sub-inhibitory concentrations (SIC) of trans-cinnamaldehyde (TC), an ingredient in cinnamon, for reducing C. sakazakii virulence in vitro using cell culture, microscopy and gene expression assays. TC significantly (p ? 0.05) suppressed C. sakazakii adhesion to and invasion of human and rat intestinal epithelial cells, and human brain microvascular endothelial cells. In addition, TC inhibited C. sakazakii survival and replication in human macrophages. We also observed that TC reduced the ability of C. sakazakii to cause cell death in rat intestinal cells, by inhibiting nitric oxide production. Results from gene expression studies revealed that TC significantly downregulated the virulence genes critical for motility, host tissue adhesion and invasion, macrophage survival, and LPS (Lipopolysaccharide) synthesis in C. sakazakii. The efficacy of TC in attenuating these major virulence factors in C. sakazakii underscores its potential use in the prevention and/or control of infection caused by this pathogen. PMID:24837831

Amalaradjou, Mary Anne Roshni; Kim, Kwang Sik; Venkitanarayanan, Kumar

2014-01-01

50

Naloxone does not increase the minimum alveolar anesthetic concentration of sevoflurane in mice.  

PubMed

Several previous studies concluded that opioid receptors do not mediate the capacity of inhaled anesthetics to produce immobility in the face of noxious stimulation because administration of naloxone (a nonspecific opioid receptor antagonist) does not increase the minimum alveolar anesthetic concentration (MAC) of inhaled anesthetic that produces immobility in 50% of subjects given a noxious stimulation. In contrast, a recent study found that 0.1 mg/kg naloxone given intraperitoneally increased sevoflurane MAC in mice by 18% (P < 0.01). We repeated the recent study with sevoflurane in the same strain of mice, administering nothing (control), 0.1 mg/kg, and 1.0 mg/kg of naloxone. Our study differed in that we also tested a parallel group given saline rather than naloxone. We were blinded to drug administration. MAC decreased 4.8% +/- 11.0% (mean+/- sd) and 2.4% +/- 12.5% with the first and second administrations of saline. Similarly, MAC decreased 4.7% +/- 7.1% and 5.5% +/- 10.0% with the administration of 0.1 mg/kg and 1.0 mg/kg of naloxone. We do not find that naloxone increases MAC. Opioid receptors do not underlie a portion of the capacity of inhaled anesthetics to produce immobility. PMID:16632825

Liao, Mark; Laster, Michael J; Eger, Edmond I; Tang, Michael; Sonner, James M

2006-05-01

51

Serum macrophage inhibitory cytokine-1 concentrations correlate with the presence of prostate cancer bone metastases.  

PubMed

Macrophage-inhibitory cytokine-1 (MIC-1) is a divergent member of the transforming growth factor beta superfamily. It is up-regulated by nonsteroidal anti-inflammatory drugs and is highly expressed in human prostate cancer leading to high serum MIC-1 concentrations with advanced disease. A role for MIC-1 has been implicated in the process of early bone formation, suggesting that it may also mediate sclerosis at the site of prostate cancer bone metastases. Consequently, the aim of this study was to retrospectively determine the relationship of serum MIC-1 concentration and other markers related to current and future prostate cancer bone metastasis in a cohort of 159 patients with prostate cancer. Serum markers included cross-linked carboxy-terminal telopeptide of type I collagen, prostate-specific antigen, and amino-terminal propeptide of type I procollagen (PINP). The mean values of all the biomarkers studied were significantly higher in patients with baseline bone metastases (BM+, n = 35), when compared with those without bone metastases (BM-, n = 124). In a multivariate logistic model, both MIC-1 and PINP independently predicted the presence of baseline bone metastasis. Based on receiver operator curve analysis, the best predictor for the presence of baseline bone metastasis was MIC-1, which was significantly better than carboxy-terminal telopeptide of type I collagen, prostate-specific antigen, and PINP. Patients who experienced bone relapse had significantly higher levels of baseline MIC-1 compared with patients who did not (1476.7 versus 988.4; P = 0.03). Current use of acetylsalicylic acid did not influence serum MIC-1 levels in this cohort. Although requiring validation prospectively, these results suggest that serum MIC-1 determination may be a valuable tool for the diagnosis of current and future bone metastases in patients with prostate cancer. PMID:17372249

Selander, Katri S; Brown, David A; Sequeiros, Guillermo Blanco; Hunter, Mark; Desmond, Renee; Parpala, Teija; Risteli, Juha; Breit, Samuel N; Jukkola-Vuorinen, Arja

2007-03-01

52

Operation of suspended-growth shortcut biological nitrogen removal (SSBNR) based on the minimum\\/maximum substrate concentration  

Microsoft Academic Search

This study exploited the concept of the minimum\\/maximum substrate concentrations (MSC values) for identifying proper start-up conditions and achieving stable and low effluent total ammonium nitrogen (TAN) concentrations in suspended-growth short-cut biological nitrogen removal (SSBNR). Calculations based on the MSC concept indicated that SDmax, the TAN concentration above which ammonium-oxidizing bacteria (AOB) are washed out, was around 450mgTAN\\/L at the

Wookeun Bae; Bruce E. Rittmann; Seungjin Kim; Jinwook Chung

2010-01-01

53

Effects of lidocaine, dexmedetomidine or their combination on the minimum alveolar concentration of sevoflurane in dogs.  

PubMed

The aim of this study was to determine the effects of lidocaine (LIDO) and dexmedetomidine (DEX) or their combination (LIDO-DEX), administered by constant-rate infusion (CRI), on the minimum alveolar concentration (MAC) of sevoflurane in dogs. Seven healthy mongrel dogs were used with a 2-week washout interval between treatments in this study. Anesthesia was induced with propofol and maintained with sevoflurane in oxygen, and MAC of sevoflurane was determined after 90 min equilibration period in the dogs (SEV-MACBASAL). Then, sevoflurane MAC was determined again in the dogs after 45 min equilibration period of one of the following treatments: an intravenous loading dose of lidocaine 2 mg/kg followed by 6 mg/kg/hr CRI (SEV-MACLIDO); an intravenous loading dose of dexmedetomidine 2 µg/kg followed by 2 µg/kg/hr CRI (SEV-MACDEX); or their combination (SEV-MACLIDO-DEX). These SEV-MACs were determined in duplicate. Data were analyzed using ANOVA and post hoc Tuckey test when appropriate. The SEV-MACBASAL was 1.82 ± 0.06%, SEV-MACLIDO was 1.38 ± 0.08%, SEV-MACDEX was 1.22 ± 0.10%, and SEV-MACLIDO-DEX was 0.78 ± 0.06%. The CRI administration of lidocaine, dexmedetomidine and their combination produced a significant reduction in the MAC of sevoflurane by 26.1 ± 9.0% (P<0.0001), 43.7 ± 11.8% (P<0.0002) and 54.4 ± 9.8% (P<0.0001), respectively. The MAC reduction was significantly greater after the CRI combination of lidocaine and dexmedetomidine when compared with lidocaine CRI (P<0.0001) or dexmedetomidine CRI treatments (P<0.025). PMID:24572631

Moran-Muńoz, Rafael; Ibancovichi, J A; Gutierrez-Blanco, Eduardo; Acevedo-Arcique, Carlos M; Victoria Mora, J Mauro; Tendillo, Francisco J; Santos-Gonzalez, Martin; Yamashita, Kazuto

2014-07-01

54

Effects of Lidocaine, Dexmedetomidine or Their Combination on the Minimum Alveolar Concentration of Sevoflurane in Dogs  

PubMed Central

ABSTRACT The aim of this study was to determine the effects of lidocaine (LIDO) and dexmedetomidine (DEX) or their combination (LIDO–DEX), administered by constant-rate infusion (CRI), on the minimum alveolar concentration (MAC) of sevoflurane in dogs. Seven healthy mongrel dogs were used with a 2-week washout interval between treatments in this study. Anesthesia was induced with propofol and maintained with sevoflurane in oxygen, and MAC of sevoflurane was determined after 90 min equilibration period in the dogs (SEV-MACBASAL). Then, sevoflurane MAC was determined again in the dogs after 45 min equilibration period of one of the following treatments: an intravenous loading dose of lidocaine 2 mg/kg followed by 6 mg/kg/hr CRI (SEV-MACLIDO); an intravenous loading dose of dexmedetomidine 2 µg/kg followed by 2 µg/kg/hr CRI (SEV-MACDEX); or their combination (SEV-MACLIDO-DEX). These SEV-MACs were determined in duplicate. Data were analyzed using ANOVA and post hoc Tuckey test when appropriate. The SEV-MACBASAL was 1.82 ± 0.06%, SEV-MACLIDO was 1.38 ± 0.08%, SEV-MACDEX was 1.22 ± 0.10%, and SEV-MACLIDO-DEX was 0.78 ± 0.06%. The CRI administration of lidocaine, dexmedetomidine and their combination produced a significant reduction in the MAC of sevoflurane by 26.1 ± 9.0% (P<0.0001), 43.7 ± 11.8% (P<0.0002) and 54.4 ± 9.8% (P<0.0001), respectively. The MAC reduction was significantly greater after the CRI combination of lidocaine and dexmedetomidine when compared with lidocaine CRI (P<0.0001) or dexmedetomidine CRI treatments (P<0.025).

MORAN-MUNOZ, Rafael; IBANCOVICHI, J. A.; Gutierrez-BLANCO, Eduardo; ACEVEDO-ARCIQUE, Carlos M.; Victoria MORA, J. Mauro; TENDILLO, Francisco J.; SANTOS-GONZALEZ, Martin; YAMASHITA, Kazuto

2014-01-01

55

Minimal Inhibitory Concentration of Ceftazidime and Co-trimoxazole for Stenotrophomonas Maltophilia using E-test  

PubMed Central

Background Stenotrophomonas maltophilia, previously named as Pseudomonas or Xanthomonas maltophilia, is an important nosocomial pathogen Aim The purpose of the present study was to investigate the prevalence of S. maltophilia in Iranian hospitals and its susceptibility to available antimicrobial agents. Setting and design: A cross-sectional study in Imam Khomeini Hospital affiliated to Tehran University of Medical Sciences. Materials and Methods All blood specimens were sent to the laboratory for blood culture and biochemical analysis. One hundred samples were positive for S. maltophilia. We used disk diffusion and E-test in order to determine minimal inhibitory concentration (MIC) of ceftazidime and co-trimoxazole as the first line antibiotics for S. maltophilia. The tests were performed and interpreted according to the guidelines of Clinical Laboratory Standards Institute (CLSI). Statistical analysis: Chi-square test and Kappa measurement of agreement were applied as appropriate. Results S. maltophilia was the most frequent pathogen (895 specimens; 38.9%) isolated from the samples which were mostly from emergency ward (780 specimens; 33.9%). Ceftazidime MIC50 and MIC90 were 2 and 32 ?g/ml, respectively (sensitive ?8 ?g/ml and resistant ?32 ?g/ml according to CLSI guideline). MIC50 and MIC90 for co-trimoxazole were 0.5 and 2 ?g/ml, respectively (sensitive ?2 ?g/ml and resistant ?4 ?g/ml according to CLSI guideline). Conclusion S. maltophilia is the most frequent pathogen in our hospital with a high susceptibility to both ceftazidime and co-trimoxazole.

Jamali, Firoozeh; Boroumand, Mohammad Ali; Yazdani, Farzad; Anvari, Maryam Sotoudeh; Pourgholi, Leila; Mahfouzi, Saeede; Khak, Mohammad

2011-01-01

56

Effect of flumazenil on sevoflurane requirements for minimum alveolar anesthetic concentration-awake and recovery status  

PubMed Central

Objective: It is controversial that whether the GABA receptors contribute to the hypnotic action of volatile anesthetics. This study was to detect the effect of GABA receptors on the hypnotic action of volatile anesthetics by evaluation of the effect of intravenous flumazenil on sevoflurane minimum alveolar anesthetic concentration–awake (MAC-Awake) and emergence mental status. Methods: This study included two steps. Firstly, 49 healthy patients, aged 20-40 years scheduled for elective surgeries, were randomly assigned to two groups, a flumazenil group (n=24) and a saline group (n=25). The flumazenil group received 0.006 mg/Kg IV, and the control group received the same volume of saline 20 min before induction. The flumazenil group and the control group were compared with regard to MAC-Awake (anesthetic concentration achieving 50% probability of eye opening in response to a verbal command). We used the mask inhalation to measure the MAC-Awake by up-and-down method. The second steps, 60 patients undergoing lower abdomen surgeries were randomly divided into two groups, a experimental group (n=30) and a saline group (n=30). All patients were anesthetized with sevoflurane/sulfentanil. The experimental group received flumazenil at 0.006 mg/Kg IV, and the control group received the same volume of saline at the end of surgery. We recorded the time to awake and extubation. After extubation, the patients’ recovery status was scored with the Mini-Mental state examination (MMSE) system in post anesthesia care unit (PACU). Results: The MAC-Awake was 0.65% in the control group and 0.82% in the flumazenil group (p=0.34). After extubation, the recovery time and time to extubation showed no difference between the flumazenil group and the saline group (p>0.05). But the 10 min and 15 min MMSE scores after extubation were better in the flumazenil group than those in the saline group (p<0.05). There was no difference for MMSE scores after 30 min between two groups. Conclusion: We found that an IV flumazenil (0.006 mg/Kg) has no effect on sevoflurane MAC-Awake in humans. A single intravenous injection of flumazenil (0.006 mg/Kg) can partially reverse the hypnotic effect of sevoflurane/sulfentanil but do not contribute to reduction in the time to recovery and extubation.

Liang, Peng; Zhou, Cheng; Li, Kai-Yu; Guo, Li-Juan; Liu, Bin; Liu, Jin

2014-01-01

57

Macrolides decrease the minimal inhibitory concentration of anti-pseudomonal agents against Pseudomonas aeruginosa from cystic fibrosis patients in biofilm  

PubMed Central

Background Biofilm production is an important mechanism for bacterial survival and its association with antimicrobial resistance represents a challenge for the patient treatment. In this study we evaluated the in vitro action of macrolides in combination with anti-pseudomonal agents on biofilm-grown Pseudomonas aeruginosa recovered from cystic fibrosis (CF) patients. Results A total of 64 isolates were analysed. The biofilm inhibitory concentration (BIC) results were consistently higher than those obtained by the conventional method, minimal inhibitory concentration, (MIC) for most anti-pseudomonal agents tested (ceftazidime: P?=?0.001, tobramycin: P?=?0.001, imipenem: P?concentration of macrolides. Strong inhibitory quotient was observed when azithromycin at 8 mg/L was associated with all anti-pseudomonal agents tested in biofilm conditions. Conclusions P. aeruginosa from CF patients within biofilms are highly resistant to antibiotics but macrolides proved to augment the in vitro activity of anti-pseudomonal agents.

2012-01-01

58

Zeolites relieves inhibitory stress from high concentrations of long chain fatty acids.  

PubMed

Protein and fat rich slaughterhouse waste is a very attractive waste stream for the production of biogas because of the high biochemical methane potential of the substrate. The material has however some drawbacks as the sole material for biogas production due to the production of several process disturbing metabolites such as ammonia, sulfides and long chain fatty acids. We can in this work present results that show that zeolites have the potential to relieve inhibitory stress from the presence of long chain fatty acids. Moreover, the results strongly indicate that it is mainly acetic acid consumers that are most negatively affected by long chain fatty acids and that the mechanism of stress relief is an adsorption of long chain fatty acids to the zeolites. In addition to this, it is shown that the effect is immediate and that only a small amount of zeolites is necessary to cancel the inhibitory effect of long chain fatty acids. PMID:24001554

Nordell, Erik; Hansson, Anna B; Karlsson, Martin

2013-12-01

59

Effect of cigarette smoke on human serum trypsin inhibitory capacity and antitrypsin concentration  

SciTech Connect

Investigation of the effect of cigarette smoke on the serum trypsin inhibitory capacity (TIC) and antitrypsin content in 89 smokers compared with 37 nonsmokers revealed that cigarette smoking is associated with a significantly lower level of TIC. No alteration in serum antitrypsin content was found because of cigarette smoking. Further analysis of the data indicated a correlation between the magnitude of smoking and the reduction in serum TIC. The reduction of TIC in cigarette smokers is consistent with the recent findings of decreased alpha 1-antitrypsin activity in rat lung and the reduced elastase inhibitory capacity per mg of alpha 1-antitrypsin found in the serum of smokers. The decrease in TIC in the serum of smokers, in addition to the reported decrease in elastolytic activity, may be useful in explaining the pathogenesis of emphysema frequently found in smokers.

Chowdhury, P.; Bone, R.C.; Louria, D.B.; Rayford, P.L.

1982-07-01

60

Mutations in the 50S ribosomal subunit of Brachyspira hyodysenteriae associated with altered minimum inhibitory concentrations of pleuromutilins.  

PubMed

Brachyspira hyodysenteriae, the causative agent of swine dysentery, is responsible for severe mucohaemorrhagic colitis with considerable financial loss to worldwide swine production. Antimicrobial resistance against macrolides and lincosamides is widespread and the mechanisms are well known. Currently, the most common treatment for swine dysentery is the use of pleuromutilins and resistance to these drugs also is increasingly being reported. Although resistance mechanisms against pleuromutilins are less clear than for other drugs, they seem to involve alterations of the peptidyl transferase centre (PTC), including ribosomal RNA and the ribosomal protein L3. The present study was conducted to examine molecular mechanisms of resistance on a representative set of B. hyodysenteriae field strains with different resistance patterns. In total, we identified 24 single nucleotide polymorphisms (SNPs) in the 23S rRNA gene and genes of the ribosomal proteins L3, L4, L2 and L22. The SNP in the ribosomal protein gene L3 at position 443 led to an amino acid substitution of asparagine (Asn) by serine (Ser) at position 148, significantly associated with MICs for pleuromutilins. Based on this SNP a correct assignment of 71% of the strains with respect to a threshold of >0.625?gtiamulin/ml was reached. Unexpectedly low MICs in some of the Asn-strains were explained by a second SNP at position 2535 of the 23S rRNA. Our results clearly show the associations between MICs for pleuromutilins and mutations in their binding site. A complete list of SNPs that influence MICs of B. hyodysenteriae strains is needed to enable the interpretation of future molecular susceptibility testing. PMID:24948419

Hillen, Sonja; Willems, Hermann; Herbst, Werner; Rohde, Judith; Reiner, Gerald

2014-08-01

61

Low ethanol concentrations enhance GABAergic inhibitory postsynaptic potentials in hippocampal pyramidal neurons only after block of GABAB receptors.  

PubMed Central

Despite considerable evidence that ethanol can enhance chloride flux through the gamma-aminobutyric acid type A (GABA/A/) receptor-channel complex in several central neuron types, the effect of ethanol on hippocampal GABAergic systems is still controversial. Therefore, we have reevaluated this interaction in hippocampal pyramidal neurons subjected to local monosynaptic activation combined with pharmacological isolation of the various components of excitatory and inhibitory synaptic potentials, using intracellular current- and voltage-clamp recording methods in the hippocampal slice. In accord with our previous findings, we found that ethanol had little effect on compound inhibitory postsynaptic potentials/currents (IPSP/Cs) containing both GABA/A/ and GABA/B/ components. However, after selective pharmacological blockade of the GABA/B/ component of the IPSP (GABA/B/-IPSP/C) by CGP-35348, low concentrations of ethanol (22-66 mM) markedly enhanced the peak amplitude, and especially the area, of the GABA/A/ component (GABA/A/-IPSP/C) in most CA1 pyramidal neurons. Ethanol had no significant effect on the peak amplitude or area of the pharmacologically isolated GABA/B/-inhibitory postsynaptic current (IPSC). These results provide new data showing that activation of GABAB receptors can obscure ethanol enhancement of GABA/A/ receptor function in hippocampus and suggest that similar methods of pharmacological isolation might be applied to other brain regions showing negative or mixed ethanol-GABA interactions.

Wan, F J; Berton, F; Madamba, S G; Francesconi, W; Siggins, G R

1996-01-01

62

The bacterial biofilms in dialysis water systems and the effect of the sub inhibitory concentrations of chlorine on them.  

PubMed

Introduction: The presence of bacteria in the form of biofilms poses a problem in the fluid pathways of haemodialysis plants and procedures which are aimed to detach and neutralize biofilms are necessary to improve the patient safety and the quality of the healthcare. The present study was therefore aimed at isolating the organisms which colonized dialysis water systems as biofilms, as well as to study the effect of the sub inhibitory concentrations of chlorine on the biofilms which were produced by these isolates. Methods: Swabs were used to collect the biofilms which were produced on the internal surface of the dialysis tubing from the dialysis units. This study was conducted at the Department of Microbiology, Kasturba Medical College (KMC), Mangalore, India. The cultures were performed on MacConkey's agar and blood agar. The organisms which were isolated were identified and antibiotic sensitivity tests were performed. The biofilm production was done by the microtitre plate method of O'Toole and Kolter. The biofilm production was also studied in the presence of sub inhibitory concentrations of chlorine. Results: Acinetobacter spp and Pseudomonas aeruginosa were the two predominant organisms which colonized the dialysis water systems as biofilms. The sub inhibitory concentrations of chlorine did not bring about any decrease in the biofilm production by the isolates. On the contrary, there was an increase in the biofilm production. Conclusion: Our study highlighted the importance of using appropriate methods to improve the quality of the water in dialysis units. This in turn, may help in reducing the biofilm formation in the water systems of dialysis units and thus, contribute to the prevention of hospital acquired infections in the patients who need haemodialysis. PMID:23814726

Suman, Ethel; Varghese, Benji; Joseph, Neethu; Nisha, Kumari; Kotian, M Shashidhar

2013-05-01

63

A New Freeze Concentration Process for Minimum Effluent Process in Bleached Pulp  

SciTech Connect

This project researches freeze concentration as a primary volume reduction technology for bleaching plant effluents from paper-pulp mills before they are treated by expensive technologies, such as incineration, for the destruction of the adsorbable organic halogens. Previous laboratory studies show that freeze concentration has a greater than 99.5% purification efficiency for volatile, semivolatile, and nonprocess elements, or any other solute, thus producing pure ice that can be reused in the mill as water. The first section evaluates the anticipated regulatory and public pressures associated with implementing the technology; the remaining sections deal with the experimental results from a scaled-up freeze concentration process in a 100-liter pilot-plant at Tufts University. The results of laboratory scale experiments confirmed that the freeze concentration technology could be an efficient volume reduction technology for the above elements and for removing adsorbable organic hologens and or nonprocess elements from recycled water. They also provide the necessary data for designing and operating a larger pilot plant, and identify the technical problems encountered in the scale-up and the way they could be addressed in the larger scale plants. This project was originally planned to include the operation of a large pilot plant in the facilities of Swenson Process Equipment Inc., and a field test at a pulp mill, but the paper company withdrew its financial support for the field test. In place of a final economic evaluation after the field test, a preliminary evaluation based on the small pilot plant data predicts an economically reasonable freeze concentration process in the case of reduction of the bleaching-effluent flow to less than 5 m3/kkg pulp, a target anticipated in the near future.

Qian, Ru-Ying; Botsaris, Gregory D.

2001-03-06

64

Cytotoxicity and inhibitory effects of low-concentration triclosan on adipogenic differentiation of human mesenchymal stem cells  

SciTech Connect

Humans at all ages are continually exposed to triclosan (TCS), a widely used antimicrobial agent that can be found in many daily hygiene products, such as toothpastes and shampoos; however, the toxicological and biological effects of TCS in the human body after long-term and low-concentration exposure are far from being well understood. In the current study, we investigated the effects of TCS on the differentiation of human mesenchymal stem cells (hMSCs) by measuring the cytotoxicity, morphological changes, lipid accumulation, and the expression of adipocyte differentiation biomarkers during 21-day adipogenesis. Significant cytotoxicity was observed in un-induced hMSCs treated with high-concentration TCS (? 5.0 ?M TCS), but not with low-concentration treatments (? 2.5 ?M TCS). TCS inhibited adipocyte differentiation of hMSCs in a concentration-dependent manner in the 0.156 to 2.5 ?M range as indicated by morphological changes with Oil Red O staining, which is an index of lipid accumulation. The inhibitory effect was confirmed by a decrease in gene expression of specific adipocyte differentiation biomarkers including adipocyte protein 2, lipoprotein lipase, and adiponectin. Our study demonstrates that TCS inhibits adipocyte differentiation of hMSCs under concentrations that are not cytotoxic and in the range observed in human blood. -- Highlights: ? TCS is cytotoxic to un-induced hMSCs at concentrations ? 5.0 ?M. ? TCS at concentrations ? 2.5 ?M is not cytotoxic to induced hMSCs. ? TCS at non-cytotoxic concentrations inhibits lipid formation in induced hMSCs. ? TCS decreases the expression of specific biomarkers of adipocyte differentiation. ? TCS at concentrations observed in human blood inhibits adipogenesis of hMSCs.

Guo, Li-Wu [Division of Personalized Nutrition and Medicine, National Center for Toxicological Research, Food and Drug Administration, Jefferson, AR 72079 (United States)] [Division of Personalized Nutrition and Medicine, National Center for Toxicological Research, Food and Drug Administration, Jefferson, AR 72079 (United States); Wu, Qiangen [Division of Biochemical Toxicology, National Center for Toxicological Research, Food and Drug Administration, Jefferson, AR 72079 (United States)] [Division of Biochemical Toxicology, National Center for Toxicological Research, Food and Drug Administration, Jefferson, AR 72079 (United States); Green, Bridgett; Nolen, Greg [Division of Personalized Nutrition and Medicine, National Center for Toxicological Research, Food and Drug Administration, Jefferson, AR 72079 (United States)] [Division of Personalized Nutrition and Medicine, National Center for Toxicological Research, Food and Drug Administration, Jefferson, AR 72079 (United States); Shi, Leming [Division of Systems Biology, National Center for Toxicological Research, Food and Drug Administration, Jefferson, AR 72079 (United States)] [Division of Systems Biology, National Center for Toxicological Research, Food and Drug Administration, Jefferson, AR 72079 (United States); LoSurdo, Jessica [Division of Cellular and Gene Therapies, Center for Biologics Evaluation and Research, Food and Drug Administration, Bethesda, MD 20892 (United States)] [Division of Cellular and Gene Therapies, Center for Biologics Evaluation and Research, Food and Drug Administration, Bethesda, MD 20892 (United States); Deng, Helen [Arkansas Department of Health, Little Rock, AR 72205 (United States)] [Arkansas Department of Health, Little Rock, AR 72205 (United States); Bauer, Steven [Division of Cellular and Gene Therapies, Center for Biologics Evaluation and Research, Food and Drug Administration, Bethesda, MD 20892 (United States)] [Division of Cellular and Gene Therapies, Center for Biologics Evaluation and Research, Food and Drug Administration, Bethesda, MD 20892 (United States); Fang, Jia-Long, E-mail: jia-long.fang@fda.hhs.gov [Division of Biochemical Toxicology, National Center for Toxicological Research, Food and Drug Administration, Jefferson, AR 72079 (United States)] [Division of Biochemical Toxicology, National Center for Toxicological Research, Food and Drug Administration, Jefferson, AR 72079 (United States); Ning, Baitang, E-mail: baitang.ning@fda.hhs.gov [Division of Personalized Nutrition and Medicine, National Center for Toxicological Research, Food and Drug Administration, Jefferson, AR 72079 (United States)] [Division of Personalized Nutrition and Medicine, National Center for Toxicological Research, Food and Drug Administration, Jefferson, AR 72079 (United States)

2012-07-15

65

Cytotoxicity and inhibitory effects of low-concentration triclosan on adipogenic differentiation of human mesenchymal stem cells.  

PubMed

Humans at all ages are continually exposed to triclosan (TCS), a widely used antimicrobial agent that can be found in many daily hygiene products, such as toothpastes and shampoos; however, the toxicological and biological effects of TCS in the human body after long-term and low-concentration exposure are far from being well understood. In the current study, we investigated the effects of TCS on the differentiation of human mesenchymal stem cells (hMSCs) by measuring the cytotoxicity, morphological changes, lipid accumulation, and the expression of adipocyte differentiation biomarkers during 21-day adipogenesis. Significant cytotoxicity was observed in un-induced hMSCs treated with high-concentration TCS (? 5.0 ?M TCS), but not with low-concentration treatments (? 2.5 ?M TCS). TCS inhibited adipocyte differentiation of hMSCs in a concentration-dependent manner in the 0.156 to 2.5 ?M range as indicated by morphological changes with Oil Red O staining, which is an index of lipid accumulation. The inhibitory effect was confirmed by a decrease in gene expression of specific adipocyte differentiation biomarkers including adipocyte protein 2, lipoprotein lipase, and adiponectin. Our study demonstrates that TCS inhibits adipocyte differentiation of hMSCs under concentrations that are not cytotoxic and in the range observed in human blood. PMID:22726953

Guo, Li-Wu; Wu, Qiangen; Green, Bridgett; Nolen, Greg; Shi, Leming; Losurdo, Jessica; Deng, Helen; Bauer, Steven; Fang, Jia-Long; Ning, Baitang

2012-07-15

66

Dipeptidyl peptidase-IV inhibitory peptides generated by tryptic hydrolysis of a whey protein concentrate rich in ?-lactoglobulin.  

PubMed

Dipeptidyl peptidase-IV (DPP-IV) is a serine protease involved in the degradation and inactivation of incretin hormones that act by stimulating glucose-dependent insulin secretion after meal ingestion. DPP-IV inhibitors have emerged as new and promising oral agents for the treatment of type 2 diabetes. The purpose of this study was to investigate the potential of ?-lactoglobulin as natural source of DPP-IV inhibitory peptides. A whey protein concentrate rich in ?-lactoglobulin was hydrolysed with trypsin and fractionated using a chromatographic separation at semipreparative scale. Two of the six collected fractions showed notable DPP-IV inhibitory activity. These fractions were analysed by HPLC coupled to tandem mass spectrometry (HPLC-MS/MS) to identify peptides responsible for the observed activity. The most potent fragment (IPAVF) corresponded to ?-lactoglobulin f(78-82) which IC50 value was 44.7?M. The results suggest that peptides derived from ?-lactoglobulin would be beneficial ingredients of foods against type 2 diabetes. PMID:23790888

Silveira, Silvana T; Martínez-Maqueda, Daniel; Recio, Isidra; Hernández-Ledesma, Blanca

2013-11-15

67

Antioxidant capacity and angiotensin I converting enzyme inhibitory activity of a melon concentrate rich in superoxide dismutase.  

PubMed

Antioxidant capacity and angiotensin 1-converting enzyme (ACE) inhibitory activity of a melon concentrate rich in superoxide dismutase (SOD-MC) were investigated in vitro. The total antioxidant capacity (TAC) was measured by the Trolox equivalent antioxidant capacity assay (TEAC), the 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical assay, and the ferric reducing antioxidant power assay (FRAP). The ability of the extract to scavenge three specific reactive oxygen species (superoxide radical anion (O(2)(-)), hydroxyl radical (HO()) and hydrogen peroxide (H(2)O(2))) was also investigated in order to better evaluate its antioxidant properties. Even if the measures of TAC were relatively low, results clearly established an antioxidant potential of SOD-MC that exhibited the highest radical-scavenging activity towards O(2)(-), with a IC(50) 12-fold lower than that of H(2)O(2) or HO(). This lets hypothesis that the antioxidant potential of SOD-MC could be mainly due to its high level of SOD. Moreover, for the first time, an ACE inhibitory activity of SOD-MC (IC(50)=2.4±0.1mg/mL) was demonstrated, showing that its use as a functional food ingredient with potential preventive benefits in the context of hypertension may have important public health implications and should be carefully considered. PMID:22953857

Carillon, Julie; Del Rio, Daniele; Teissčdre, Pierre-Louis; Cristol, Jean-Paul; Lacan, Dominique; Rouanet, Jean-Max

2012-12-01

68

Darunavir is predominantly unbound to protein in cerebrospinal fluid and concentrations exceed the wild-type HIV-1 median 90% inhibitory concentration  

PubMed Central

Objectives Higher CSF antiretroviral concentrations may be associated with better control of HIV replication and neurocognitive performance, but only the unbound fraction of antiretrovirals is available to inhibit HIV. Therefore, the objective of this study was to determine total and unbound darunavir concentrations in CSF and compare findings with plasma concentrations as well as the wild-type HIV-1 90% inhibitory concentration (IC90). Methods Subjects with HIV infection were selected based on the use of darunavir-containing regimens with a twice-daily dosing schedule and availability of stored CSF and matched plasma. Total darunavir was measured by HPLC for plasma or liquid chromatography–tandem mass spectroscopy (LC/MS/MS) for CSF. Plasma unbound darunavir was measured by ultrafiltration and LC/MS/MS. CSF protein binding was determined by competitive binding exchange with radiolabelled darunavir. Results Twenty-nine matched CSF–plasma pairs were analysed and darunavir was detected in all CSF specimens (median total concentration 55.8 ng/mL), with a CSF unbound fraction of 93.5%. Median fractional penetrance was 1.4% of median total and 9.4% of median unbound plasma concentrations. Unbound darunavir concentrations in CSF exceeded the median IC90 for wild-type HIV in all subjects by a median of 20.6-fold, despite the relatively low fractional penetrance. Total darunavir concentrations in CSF correlated with both total and unbound darunavir concentrations in plasma. Conclusions Darunavir should contribute to the control of HIV replication in the CNS as a component of effective combination antiretroviral regimens.

Croteau, David; Rossi, Steven S.; Best, Brookie M.; Capparelli, Edmund; Ellis, Ronald J.; Clifford, David B.; Collier, Ann C.; Gelman, Benjamin B.; Marra, Christina M.; McArthur, Justin; McCutchan, J. Allen; Morgello, Susan; Simpson, David M.; Grant, Igor; Letendre, Scott

2013-01-01

69

The inhibitory degree between Skeletonema costatum and dinoflagllate Prorocentrum donghaiense at different concentrations of phosphate and nitrate/phosphate ratios  

NASA Astrophysics Data System (ADS)

Interactions between Skeletonema costatum ( S. costatum) and Prorocentrum donghaiense ( P. donghaiiense) were investigated using bi-algal cultures at different concentrations of phosphate (PO4-P) and nitrate/phosphate (N/P) ratios. Experiments were conducted under P-limited conditions and the Lotka-Volterra mathematical model was used to simulate the growth of S. costatum and P. donghaiense in the bi-algal cultures. Both of these two species were inhibited significantly in bi-algal culture. The results of the simulation showed that the inhibitory degree of S. costaum by P. donghaiense was high when the concentration of PO4-P was low (0.1 ?molL-1/2 d), but that of P. donghaiense by S. costaum was high with increased PO4-P supply (0.6 ?molL-1/2 d). At low concentration of PO4-P (0.1 ?molL-1/2 d), or high concentration of PO4-P (0.6 ?molL-1/2 d) with high N/P ratio (160), the interactions between S. costatum and P. donghaiense were dependent on the initial cell densities of both species. At high concentration of PO4-P (0.6 ?molL-1/2 d) with low N/P ratio (25 or 80), S. costatum exhibited a survival strategy superior to that of P. donghaiense. The degree of inhibition of P. donghaiense by S. costaum increased with elevated N/P ratio when the medium was supplemented with concentration 0.1 ?molL-1/2 d of PO4-P. The degree of inhibition to P. donghaiense by S. costaum increased with elevated N/P ratio at low concentration of PO4-P (0.1 ?molL-1/2 d). This trend was conversed at high concentration of PO4-P (0.6 ?molL-1/2 d). However, the degree of inhibition of S. costaum by P. donghaiense increased with the increased N/P ratio at different PO4-P concentrations (0.1 ?molL-1/2 d and 0.6 ?molL-1/2 d). These results suggested that both phosphate concentration and N/P ratio affected the competition between S. costaum and P. donghaiense: P. donghaiense is more competitive in environments with low phosphate or high N/P ratio and the influence of N/P ratio on the competition was more significant with lower phosphate concentration.

Cao, Jing; Wang, Jiangtao

2012-06-01

70

Sparing Effect of Robenacoxib on the Minimum Alveolar Concentration for Blunting Adrenergic Response (MAC-BAR) of Sevoflurane in Dogs  

PubMed Central

ABSTRACT Robenacoxib is a newer nonsteroidal anti-inflammatory drug approved for dogs and cats. This study was designed to evaluate the effect of robenacoxib on the minimum alveolar concentration for blunting adrenergic response (MAC-BAR) of sevoflurane in dogs. Sevoflurane MAC-BAR was determined by judging dogs’ response to a noxious electrical stimulus (50 V, 50 Hz and 10 msec) for 10 sec in 6 beagle dogs on two occasions at least a 7-day interval. In each occasion, saline (0.1 ml/kg) or robenacoxib (2 mg/kg) was administered subcutaneously at 1 hr prior to the MAC-BAR determination. Robenacoxib significantly decreased the sevoflurane MAC-BAR (3.44 ± 0.53% for saline vs. 2.84 ± 0.38% for robenacoxib, P=0.039). These results suggest that subcutaneous robenacoxib provides a clinically relevant sparing effect on anesthetic requirement.

TAMURA, Jun; ITAMI, Takaharu; ISHIZUKA, Tomohito; FUKUI, Sho; OOYAMA, Norihiko; MIYOSHI, Kenjiro; SANO, Tadashi; YAMASHITA, Kazuto

2013-01-01

71

Evaluation of AQUI-S(TM) (efficacy and minimum toxic concentration) as a fish anaesthetic/sedative for public aquaculture in the United States  

USGS Publications Warehouse

A preliminary evaluation of efficacy and minimum toxic concentration of AQUI-S(TM), a fish anaesthetic/sedative, was determined in two size classes of six species of fish important to US public aquaculture (bluegill, channel catfish, lake trout, rainbow trout, walleye and yellow perch). In addition, efficacy and minimum toxic concentration were determined in juvenile-young adult (fish aged 1 year or older) rainbow trout acclimated to water at 7 ??C, 12 ??C and 17 ??C. Testing concentrations were based on determinations made with range-finding studies for both efficacy and minimum toxic concentration. Most of the tested juvenile-young adult fish species were induced in 3 min or less at a nominal AQUI-S(TM) concentration of 20 mg L-1. In juvenile-young adult fish, the minimum toxic concentration was at least 2.5 times the selected efficacious concentration. Three out of five species of fry-fingerlings (1.25-12.5 cm in length and < 1 year old) were induced in ??? 4.1 min at a nominal concentration of 20 mg L-1 AQUI-S(TM), with the other two species requiring nominal concentrations of 25 and 35 mg L-1 for similar times of induction. Recovery times were ??? 7.3 rain for all species in the two size classes. In fry-fingerlings, the minimum toxic concentration was at least 1.4 times the selected efficacious concentration. There appeared to be little relationship between size of fish and concentrations or times to induction, recovery times and minimum toxic concentration. The times required for induction and for recovery were increased in rainbow trout as the acclimation temperature was reduced.

Stehly, G. R.; Gingerich, W. H.

1999-01-01

72

Identification of the Major ACE-Inhibitory Peptides Produced by Enzymatic Hydrolysis of a Protein Concentrate from Cuttlefish Wastewater  

PubMed Central

The aim of this work was the purification and identification of the major angiotensin converting enzyme (ACE) inhibitory peptides produced by enzymatic hydrolysis of a protein concentrate recovered from a cuttlefish industrial manufacturing effluent. This process consisted on the ultrafiltration of cuttlefish softening wastewater, with a 10 kDa cut-off membrane, followed by the hydrolysis with alcalase of the retained fraction. Alcalase produced ACE inhibitors reaching the highest activity (IC50 = 76.8 ± 15.2 ?g mL?1) after 8 h of proteolysis. Sequential ultrafiltration of the 8 h hydrolysate with molecular weight cut-off (MWCO) membranes of 10 and 1 kDa resulted in the increased activity of each permeate, with a final IC50 value of 58.4 ± 4.6 ?g mL?1. Permeate containing peptides lower than 1 kDa was separated by reversed-phase high performance liquid chromatography (RP-HPLC). Four fractions (A–D) with potent ACE inhibitory activity were isolated and their main peptides identified using high performance liquid chromatography coupled to an electrospray ion trap Fourier transform ion cyclotron resonance-mass spectrometer (HPLC-ESI-IT-FTICR) followed by comparison with databases and de novo sequencing. The amino acid sequences of the identified peptides contained at least one hydrophobic and/or a proline together with positively charged residues in at least one of the three C-terminal positions. The IC50 values of the fractions ranged from 1.92 to 8.83 ?g mL?1, however this study fails to identify which of these peptides are ultimately responsible for the potent antihypertensive activity of these fractions.

Rodriguez Amado, Isabel; Vazquez, Jose Antonio; Gonzalez, Pilar; Esteban-Fernandez, Diego; Carrera, Monica; Pineiro, Carmen

2014-01-01

73

Discordance in the minimal inhibitory concentrations of ertapenem for Enterobacter cloacae: Vitek 2 system versus Etest and agar dilution methods.  

PubMed

Our objective was to compare the ertapenem minimal inhibitory concentrations (MICs) for Enterobacter cloacae isolates categorized intermediate or resistant to ertapenem when measured with the Vitek 2 system, with the MICs for these isolates when measured by two methods performed in agar medium: the Etest and agar plate dilution method (APDM). Overall, 50 E. cloacae isolates were included in the study. The mean MIC of ertapenem was 2.92±1.77?g/ml according to the Vitek 2 system, 0.94±0.84?g/ml according to the Etest strips, and 0.93±0.62?g/ml according to the APDM. Furthermore, the MICs determined by the Vitek 2 system were higher than the MICs determined by the two other methods for 96% of strains. Lastly, according to the Etest strips and APDM, 42% of E. cloacae were susceptible to ertapenem. No carbapenemase was identified by the screening method used. Using the Vitek 2 system to determine ertapenem MICs for E. cloacae can have potential consequences in terms of additional carbapenemase-detecting tests and antimicrobial therapy. It would be interesting to determine if the Vitek 2 system is more effective for the detection of carbapenemase producers with low-level carbapenem resistance than the two methods performed in agar medium. PMID:24183718

Pailhoričs, Hélčne; Cassisa, Viviane; Lamoureux, Claudie; Chesnay, Adélaďde; Lebreton, Cyrielle; Lemarié, Carole; Kempf, Marie; Mahaza, Chetaou; Joly-Guillou, Marie-Laure; Eveillard, Matthieu

2014-01-01

74

Temporal and spatial inhibitory effects of zinc and copper on wastewater biofilms from oxygen concentration profiles determined by microelectrodes.  

PubMed

To understand the temporal and spatial toxic effect of heavy metals on the microbial activities of biofilms, microelectrodes were used to measure the inhibitory oxygen (O(2)) concentration profiles resulted from the effects of zinc (Zn(2+)) and copper (Cu(2+)). Using the O(2) microprofiles as bases, the spatial distributions of net specific O(2) respiration were determined in biofilms with and without treatment of 5 mg/L Zn(2+) or 1 mg/L Cu(2+). Results show that microbial activities were inhibited only in the outer layer (?400 ?m) of the biofilms and bacteria present in the deeper sections of the biofilms became even more active. The inhibition caused by the heavy metals was evaluated by two methods. One was derived from the oxygen influx at the interface and the other was based on the integral of the oxygen consumption calculated from the entire O(2) profile. The two methods yielded significantly different results. We argue that the integral method results in more accurate assessment of toxicity than the surface flux determination. PMID:20950839

Zhou, Xiao-Hong; Tong, Yu; Shi, Han-Chang; Shi, Hui-Ming

2011-01-01

75

Inhibitory effects of ZnO nanoparticles on aerobic wastewater biofilms from oxygen concentration profiles determined by microelectrodes.  

PubMed

The presence of ZnO NPs in waste streams can negatively affect the efficiency of biological nutrient removal from wastewater. However, details of the toxic effects of ZnO NPs on microbial activities of wastewater biofilms have not yet been reported. In this study, the temporal and spatial inhibitory effects of ZnO NPs on the O2 respiration activities of aerobic wastewater biofilms were investigated using an O2 microelectrode. The resulting time-course microelectrode measurements demonstrated that ZnO NPs inhibited O2 respiration within 2h. The spatial distributions of net specific O2 respiration were determined in biofilms with and without treatment of 5 or 50mg/L ZnO NPs. The results showed that 50mg/L of nano-ZnO inhibited the microbial activities only in the outer layer (?200?m) of the biofilms, and bacteria present in the deeper parts of the biofilms became even more active. Scanning electron microscopy (SEM) analysis showed that the ZnO NPs were adsorbed onto the biofilm, but these NPs had no adverse effects on the cell membrane integrity of the biofilms. It was found that the inhibition of O2 respiration induced by higher concentrations of ZnO NPs (50mg/L) was mainly due to the release of zinc ions by dissolution of the ZnO NPs. PMID:24880618

Hou, Jun; Miao, Lingzhan; Wang, Chao; Wang, Peifang; Ao, Yanhui; Qian, Jin; Dai, Shanshan

2014-07-15

76

The minimum alveolar anesthetic concentration of 2-, 3-, and 4-alcohols and ketones in rats: relevance to anesthetic mechanisms.  

PubMed

The Meyer-Overton hypothesis predicts that anesthetic potency correlates inversely with lipophilicity; e.g., MAC times the olive oil/gas partition coefficient equals a constant of approximately 1.82 +/- 0.56 atm (mean +/- sd) for conventional inhaled anesthetics. MAC is the minimum alveolar concentration of anesthetic required to eliminate movement in response to a noxious stimulus in 50% of subjects. In contrast to conventional inhaled anesthetics, MAC times the olive oil/gas partition coefficient for normal alcohols from methanol through octanol equals a constant one tenth as large as that for conventional inhaled anesthetics. The alcohol (C-OH) group causes a great affinity of alcohols to water, and the C-OH may tether the alcohol at the hydrophobic-hydrophilic interface where anesthetics are thought to act. We hypothesized that the position of the C-OH group determined potency, perhaps by governing the maximum extent to which the acyl portion of the molecule might extend into a hydrophobic phase. Using the same reasoning, we added studies of ketones with similar numbers of carbon atoms between the C=O group and the terminal methyl group. The results for both alcohols and ketones showed the predicted correlation, but the correlation was no better than that with carbon chain length regardless of the placement of the oxygen. The oil/gas partition coefficient predicted potency as well as, or better than, either chain length or oxygen placement. Hydrophilicity, as indicated by the saline/gas partition coefficient, also seemed to influence potency. PMID:16632820

Won, Albert; Oh, Irene; Liao, Mark; Sonner, James M; Harris, R Adron; Laster, Michael J; Brosnan, Robert; Trudell, James R; Eger, Edmond I

2006-05-01

77

The presence of leukocytes in ex vivo assays significantly increases the 50-percent inhibitory concentrations of artesunate and chloroquine against Plasmodium vivax and Plasmodium falciparum.  

PubMed

Plasmodium species ex vivo sensitivity assay protocols differ in the requirement for leukocyte removal before culturing. This study shows that the presence of leukocytes significantly increases the 50% inhibitory concentration (IC??) of P. vivax and P. falciparum to artesunate and chloroquine relative to results with the paired leukocyte-free treatment. Although leukocyte removal is not an essential requirement for the conduct of ex vivo assays, its use has important implications for the interpretation of temporal and spatial antimalarial sensitivity data. PMID:21189344

Kaewpongsri, S; Sriprawat, K; Suwanarusk, R; Kyle, D E; Lek-Uthai, U; Leimanis, M; Lwin, K M; Phyo, A P; Zwang, J; Russell, B; Nosten, F; Renia, L

2011-03-01

78

The Presence of Leukocytes in Ex Vivo Assays Significantly Increases the 50-Percent Inhibitory Concentrations of Artesunate and Chloroquine against Plasmodium vivax and Plasmodium falciparum ?  

PubMed Central

Plasmodium species ex vivo sensitivity assay protocols differ in the requirement for leukocyte removal before culturing. This study shows that the presence of leukocytes significantly increases the 50% inhibitory concentration (IC50) of P. vivax and P. falciparum to artesunate and chloroquine relative to results with the paired leukocyte-free treatment. Although leukocyte removal is not an essential requirement for the conduct of ex vivo assays, its use has important implications for the interpretation of temporal and spatial antimalarial sensitivity data.

Kaewpongsri, S.; Sriprawat, K.; Suwanarusk, R.; Kyle, D. E.; Lek-Uthai, U.; Leimanis, M.; Lwin, K. M.; Phyo, A. P.; Zwang, J.; Russell, B.; Nosten, F.; Renia, L.

2011-01-01

79

Combined Porin Loss and Extended Spectrum ?-Lactamase Production is Associated with an Increasing Imipenem Minimal Inhibitory Concentration in Clinical Klebsiella pneumoniae Strains  

Microsoft Academic Search

For this study, 150 clinical isolates of Klebsiella pneumoniae were collected from one hospital in Beijing, China, and assayed for minimal inhibitory concentration (MIC) of imipenem. To\\u000a elucidate the mechanisms responsible for imipenem MIC variation among extended-spectrum ?-lactamase (ESBL)-positive and -negative\\u000a K. pneumoniae strains, a variety of ?-lactamase genes (bla\\u000a TEM, bla\\u000a CTX-M, bla\\u000a SHV, and bla\\u000a OXA) were screened by polymerase

Duo Yang; Yu Guo; Zheng Zhang

2009-01-01

80

Minimum inhibitory concentration (MIC) of crude preparations of Brevibacillus laterosporus SA14 bioactive material compared to vancomycin and oxacillin, against clinical isolates of methicillin-resistant Staphylococcus aureus  

Microsoft Academic Search

Secondary metabolites, particularly bioactive compounds, from probiotic bacteria, are good candidates for replacing antibiotics\\u000a to which bacteria have become resistant. In order to compare bioactive crude material from strain SA14 of Brevibacillus laterosporus with two antibiotics, the MICs of this bioactive crude and those of antibiotics vancomycin and oxacillin, against methicillin-resistant\\u000a Staphylococcus aureus (MRSA), were determined. The result indicated that

Kittisak Chawawisit; Monthon Lertcanawanichakul

2008-01-01

81

Vancomycin and daptomycin minimum inhibitory concentration distribution and occurrence of heteroresistance among methicillin-resistant Staphylococcus aureus blood isolates in Turkey  

PubMed Central

Background The aim of this study was to determine the distribution of vancomycin and daptomycin MICs among methicillin-resistant Staphylococcus aureus (MRSA) blood isolates, the prevalence of heterogeneous vancomycin-intermediate S. aureus (hVISA) and the relationship between hVISA and vancomycin MIC values. Methods A total of 175 MRSA blood isolates were collected from seven university hospitals in Turkey. All isolates were tested for susceptibility to vancomycin and daptomycin by reference broth microdilution (BMD) and by standard Etest method. BMD test was performed according to CLSI guidelines and Etest was performed according to the instructions of the manufacturer. All isolates were screened for the presence of the hVISA by using macro Etest (MET) and population analysis profile-area under the curve (PAP-AUC) methods. Results The vancomycin MIC50, MIC90 and MIC ranges were 1, 2, and 0.5-2 ?g/ml, respectively, by both of BMD and Etest. The daptomycin MIC50, MIC90 and MIC ranges were 0.5, 1 and 0.125 -1 ?g/ml by BMD and 0.25, 0.5 and 0.06-1 ?g/ml by Etest, respectively. The vancomycin MIC for 40.6% (71/175) of the MRSA isolates tested was >1 ?g/ml by BMD. No vancomycin and daptomycin resistance was found among MRSA isolates. Percent agreement of Etest MICs with BMD MICs within ±1 doubling dilution was 100% and 73.1% for vancomycin and daptomycin, respectively. The prevalence of hVISA among MRSA blood isolates was 13.7% (24/175) by PAP-AUC method. MET identified only 14 of the hVISA strains (sensitivity, 58.3%), and there were 12 strains identified as hVISA that were not subsequently confirmed by PAP-AUC (specificity, 92.1%). Conclusions Agreement between BMD and Etest MICs is high both for vancomycin and daptomycin. Daptomycin was found to be highly active against MRSA isolates including hVISA. A considerable number of isolates are determined as hVISA among blood isolates. As it is impractical to use the reference method (PAP-AUC) for large numbers of isolates, laboratory methods for rapid and accurate identification of hVISA need to be developed.

2013-01-01

82

Influence of electron donor on the minimum sulfate concentration required for sulfate reduction in a petroleum hydrocarbon-contaminated aquifer  

USGS Publications Warehouse

Fluctuations in the availability of electron donor (petroleum hydrocarbons) affected the competition between sulfate-reducing bacteria (SRB) and methanogenic bacteria (MB) for control of electron flow in a petroleum hydrocarbon-contaminated aquifer. The data suggest that abundant electron donor availability allowed MB to sequester a portion of the electron flow even when sulfate was present in sufficient concentrations to support sulfate reduction. For example, in an area of abundant electron-donor availability, SRB appeared to be unable to sequester the electron flow from MB in the presence of 1.4 mg/L sulfate. The data also suggest that when electron-donor availability was limited, SRB outcompeted MB for available substrate at a lower concentration of sulfate than when electron donor was plentiful. For example, in an area of limited electron-donor availability, SRB appeared to maintain dominance of electron flow at sulfate concentrations less than 1 mg/L. The presence of abundant electron donor and a limited amount of sulfate reduced competition for available substrate, allowing both SRB and MB to metabolize available substrates concurrently.

Vroblesky, D. A.; Bradley, P. M.; Chapelle, F. H.

1996-01-01

83

A growth inhibitory model with SO(x) influenced effective growth rate for estimation of algal biomass concentration under flue gas atmosphere.  

PubMed

A theoretical model for the prediction of biomass concentration under rice husk flue gas emission has been developed. The growth inhibitory model (GIM) considers the CO2 mass transfer rate, the critical SOx concentration and its role in pH-based inter-conversion of bicarbonate. The calibration and subsequent validation of the growth profile of Nannochloropsis limnetica at 2% and 10% (v/v) CO2 showed that the predicted values were consistent with the measured values, with r(2) being 0.96 and 0.98, respectively, and p<0.001 in both cases. The constants used in the GIM for the prediction of biomass have been justified using sensitivity analysis. GIM applicability was defined as ±30% of the calibrated flow rate (3.0 L min(-1)). This growth model can be applied to predict algal growth in photo-bioreactors treated with flue gas in the generation of biomass feed stock for biofuel production. PMID:24300846

Ronda, Srinivasa Reddy; Kethineni, Chandrika; Parupudi, Lakshmi Chandrika Pavani; Thunuguntla, Venkata Bala Sai Chaitanya; Vemula, Sandeep; Settaluri, Vijaya Saradhi; Allu, Prasada Rao; Grande, Suresh Kumar; Sharma, Suraj; Kandala, Chari Venkatakrishna

2014-01-01

84

Mumefural and related HMF derivatives from Japanese apricot fruit juice concentrate show multiple inhibitory effects on pandemic influenza A (H1N1) virus  

Microsoft Academic Search

Fruit-juice concentrate of Japanese apricot (Prunus mume Sieb. et Zucc.) has been shown to be effective against influenza A infection in MDCK cells. In this study, we isolated five components from the fruit-juice concentrate of Japanese apricot, 5-(hydroxymethyl)-2-formylfuran (HMF), 1-[5-(2-formylfuryl)methyl]dihydrogen 2-hydroxypropane-1,2,3-tricarboxylate (mumefural, MF), 2-[5-(2-formylfuryl)methyl]dihydrogen 2-hydroxypropane-1,2,3-tricarboxylate (MF‘), 1-[5-(2-formylfuryl)methyl]hydrogen 1-hydroxyethane-1,2-dicarboxylate (MA1) and 2-[5-(2-formylfuryl)methyl]hydrogen 1-hydroxyethane-1,2-dicarboxylate (MA2), and investigated their inhibitory activities against the

Nongluk Sriwilaijaroen; Akio Kadowaki; Yuriko Onishi; Nobuki Gato; Makoto Ujike; Takato Odagiri; Masato Tashiro; Yasuo Suzuki

2011-01-01

85

Impact of Synaptic Neurotransmitter Concentration Time Course on the Kinetics and Pharmacological Modulation of Inhibitory Synaptic Currents  

PubMed Central

The time course of synaptic currents is a crucial determinant of rapid signaling between neurons. Traditionally, the mechanisms underlying the shape of synaptic signals are classified as pre- and post-synaptic. Over the last two decades, an extensive body of evidence indicated that synaptic signals are critically shaped by the neurotransmitter time course which encompasses several phenomena including pre- and post-synaptic ones. The agonist transient depends on neurotransmitter release mechanisms, diffusion within the synaptic cleft, spill-over to the extra-synaptic space, uptake, and binding to post-synaptic receptors. Most estimates indicate that the neurotransmitter transient is very brief, lasting between one hundred up to several hundreds of microseconds, implying that post-synaptic activation is characterized by a high degree of non-equilibrium. Moreover, pharmacological studies provide evidence that the kinetics of agonist transient plays a crucial role in setting the susceptibility of synaptic currents to modulation by a variety of compounds of physiological or clinical relevance. More recently, the role of the neurotransmitter time course has been emphasized by studies carried out on brain slice models that revealed a striking, cell-dependent variability of synaptic agonist waveforms ranging from rapid pulses to slow volume transmission. In the present paper we review the advances on studies addressing the impact of synaptic neurotransmitter transient on kinetics and pharmacological modulation of synaptic currents at inhibitory synapses.

Barberis, Andrea; Petrini, Enrica Maria; Mozrzymas, Jerzy W.

2011-01-01

86

The interaction of nitrous oxide and fentanyl on the minimum alveolar concentration of sevoflurane blocking motor movement (MACNM) in dogs.  

PubMed

The study objective was to determine the effects of 70% nitrous oxide (N2O) and fentanyl on the end-tidal concentration of sevoflurane necessary to prevent movement (MACNM) in response to noxious stimulation in dogs. Six healthy, adult, intact male, mixed-breed dogs were used on 3 occasions in a randomized crossover design. After induction of anesthesia with sevoflurane, each of the following treatments was randomly administered: fentanyl loading dose (Ld) of 15 ?g/kg and infusion of 6 ?g/kg per hour [treatment 1 (T1)], 70% N2O (T2), or fentanyl (Ld of 15 ?g/kg and infusion of 6 ?g/kg per hour) combined with 70% N2O (T3). Each dog received each of the 3 treatments once during the 3-week period. Determination of MACNM was initiated 90 min after the start of each treatment. The values were compared using the baseline MACNM, which had been determined in a previous study on the same group of dogs. Data were analyzed using a mixed-model analysis of variance (ANOVA) and Tukey-Kramer tests, and expressed as least squares mean ± SEM. The baseline MACNM decreased by 36.6 ± 4.0%, 15.0 ± 4.0%, and 46.0 ± 4.0% for T1, T2, and T3, respectively (P < 0.05), and differed (P < 0.05) among treatments. Mean fentanyl plasma concentrations did not differ (P ? 0.05) between T1 (3.70 ± 0.56 ng/mL) and T3 (3.50 ± 0.56 ng/mL). The combination of fentanyl and N2O resulted in a greater sevoflurane MACNM sparing effect than either treatment alone. PMID:24982551

Seddighi, Reza; Doherty, Thomas J; Kukanich, Butch; Egger, Christine M; Henn, Melissa A; Long, Whitney M; Rohrbach, Barton W

2014-07-01

87

A strain of Saccharomyces cerevisiae evolved for fermentation of lignocellulosic biomass displays improved growth and fermentative ability in high solids concentrations and in the presence of inhibitory compounds  

PubMed Central

Background Softwoods are the dominant source of lignocellulosic biomass in the northern hemisphere, and have been investigated worldwide as a renewable substrate for cellulosic ethanol production. One challenge to using softwoods, which is particularly acute with pine, is that the pretreatment process produces inhibitory compounds detrimental to the growth and metabolic activity of fermenting organisms. To overcome the challenge of bioconversion in the presence of inhibitory compounds, especially at high solids loading, a strain of Saccharomyces cerevisiae was subjected to evolutionary engineering and adaptation for fermentation of pretreated pine wood (Pinus taeda). Results An industrial strain of Saccharomyces, XR122N, was evolved using pretreated pine; the resulting daughter strain, AJP50, produced ethanol much more rapidly than its parent in fermentations of pretreated pine. Adaptation, by preculturing of the industrial yeast XR122N and the evolved strains in 7% dry weight per volume (w/v) pretreated pine solids prior to inoculation into higher solids concentrations, improved fermentation performance of all strains compared with direct inoculation into high solids. Growth comparisons between XR122N and AJP50 in model hydrolysate media containing inhibitory compounds found in pretreated biomass showed that AJP50 exited lag phase faster under all conditions tested. This was due, in part, to the ability of AJP50 to rapidly convert furfural and hydroxymethylfurfural to their less toxic alcohol derivatives, and to recover from reactive oxygen species damage more quickly than XR122N. Under industrially relevant conditions of 17.5% w/v pretreated pine solids loading, additional evolutionary engineering was required to decrease the pronounced lag phase. Using a combination of adaptation by inoculation first into a solids loading of 7% w/v for 24 hours, followed by a 10% v/v inoculum (approximately equivalent to 1 g/L dry cell weight) into 17.5% w/v solids, the final strain (AJP50) produced ethanol at more than 80% of the maximum theoretical yield after 72 hours of fermentation, and reached more than 90% of the maximum theoretical yield after 120 hours of fermentation. Conclusions Our results show that fermentation of pretreated pine containing liquid and solids, including any inhibitory compounds generated during pretreatment, is possible at higher solids loadings than those previously reported in the literature. Using our evolved strain, efficient fermentation with reduced inoculum sizes and shortened process times was possible, thereby improving the overall economic viability of a woody biomass-to-ethanol conversion process.

2011-01-01

88

Spectroscopic Characterization of Extracellular Polymeric Substances from Escherichia coli and Serratia marcescens: Suppression using Sub-Inhibitory Concentrations of Bismuth Thiols  

SciTech Connect

Free and capsular EPS produced by Escherichia coli and Serratia marcescens were characterized in detail using Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), and Auger electron spectroscopy (AES). Total EPS production decreased upon treatment with sub-inhibitory concentrations of lipophilic bismuth thiols (bismuth dimercaptopropanol, BisBAL; bismuth ethanedithiol, BisEDT; and bismuth pyrithione, BisPYR), BisBAL being most effective. Bismuth thiols also influenced acetylation and carboxylation of polysaccharides in EPS from S. marcescens. Extensive homology between EPS samples in the presence and absence of bismuth was observed with proteins, polysaccharides, and nucleic acids varying predominantly only in the total amount expressed. Second derivative analysis of the amide I region of FTIR spectra revealed decreases in protein secondary structures in the presence of bismuth thiols. Hence, anti-fouling properties of bismuth thiols appear to originate in their ability to suppress O-acetylation and protein secondary structures in addition to total EPS secretion.

Badireddy, Appala R.; Korpol, Bhoom Reddy; Chellam, Shankararaman; Gassman, Paul L.; Engelhard, Mark H.; Lea, Alan S.; Rosso, Kevin M.

2008-10-21

89

Do N-methyl-D-aspartate receptors mediate the capacity of inhaled anesthetics to suppress the temporal summation that contributes to minimum alveolar concentration?  

PubMed

Antagonism of N-methyl-d-aspartate (NMDA) receptors markedly decreases the minimum alveolar concentration (MAC) of inhaled anesthetics. To assess the importance of suppression of the temporal summation NMDA receptor component of MAC, we stimulated the tail of rats with trains of electrical pulses of varying interstimulus intervals (ISIs) and determined the inhaled anesthetic concentrations (crossover concentrations) that suppressed movement at different ISIs. The slopes of crossover concentrations versus ISIs provided a measure of temporal summation for each anesthetic. We studied five anesthetics that differ widely in their in vitro capacity to block NMDA receptors. To block NMDA receptor transmission and reveal the NMDA receptor component, the NMDA receptor antagonist, MK801, was separately added during each anesthetic. Halothane, isoflurane, and hexafluorobenzene did not appreciably suppress the NMDA receptor components of temporal summation, which contributed to 21% to 29% of MAC (P < 0.05 for each). Xenon and o-difluorobenzene suppressed these components to 8% to 0%, respectively, of MAC (neither significant), consistent with their greater NMDA receptor blocking action in vitro. NMDA receptor blockade may contribute to the MAC produced by inhaled anesthetics that potently inhibit NMDA receptors in vitro but not those that have a limited in vitro effect. PMID:16632819

Dutton, Robert C; Laster, Michael J; Xing, Yilei; Sonner, James M; Raines, Douglas E; Solt, Ken; Eger, Edmond I

2006-05-01

90

Minimal inhibitory and mutant prevention concentrations of azithromycin, clarithromycin and erythromycin for clinical isolates of Streptococcus pneumoniae  

PubMed Central

Background Previous work showed a higher prevalence of macrolide/azalide resistance in provinces of Canada where azithromycin was the major treatment for Streptococcus pneumoniae as compared with regions where clarithromycin was the dominant treatment. These data provided a way to test the mutant selection window hypothesis, which predicts that the serum drug concentration (AUC24) relative to the mutant prevention concentration (MPC) would be higher for clarithromycin than for azithromycin. Methods The MIC and MPC were determined for 191 penicillin/macrolide-susceptible clinical isolates of S. pneumoniae with azithromycin, clarithromycin and erythromycin using agar plate assays. Results The MIC50/90 (mg/L) and MPC50/90 (mg/L), respectively, were as follows: azithromycin 0.13/0.25 and 1/4; clarithromycin 0.031/0.063 and 0.13/0.5; erythromycin 0.063/0.13 and 0.25/2. We calculated from published pharmacokinetic values that the AUC24/MPC90 for azithromycin was 0.85; for clarithromycin it was 96, and for erythromycin base and estolate it was 4 and 10, respectively. Thus the AUC24/MPC90 was about 50 times higher for clarithromycin than for azithromycin. Conclusions The elevated prevalence of azithromycin resistance may derive in part from a low value of AUC24/MPC90 and/or time above MPC, since previous work indicates that the number of prescriptions per person was similar in the geographical regions examined.

Metzler, Kelli; Drlica, Karl; Blondeau, Joseph M.

2013-01-01

91

Prior determination of baseline minimum alveolar concentration (MAC) of isoflurane does not influence the effect of ketamine on MAC in rabbits  

PubMed Central

The objective of this study was to compare the effect on the minimum alveolar concentration (MAC) of isoflurane when ketamine was administered either after or without prior determination of the baseline MAC of isoflurane in rabbits. Using a prospective randomized crossover study, 8 adult, female New Zealand rabbits were allocated to 2 treatment groups. Anesthesia was induced and maintained with isoflurane. Group 1 (same-day determination) had the MAC-sparing effect of ketamine [1 mg/kg bodyweight (BW) bolus followed by a constant rate infusion (CRI) of 40 ?g/kg BW per min, given by intravenous (IV)], which was determined after the baseline MAC of isoflurane was determined beforehand. A third MAC determination was started 30 min after stopping the CRI. Group 2 (separate-day determination) had the MAC-sparing effect of ketamine determined without previous determination of the baseline MAC of isoflurane. A second MAC determination was started 30 min after stopping the CRI. In group 1, the MAC of isoflurane (2.15 ± 0.09%) was significantly decreased by ketamine (1.63 ± 0.07%). After stopping the CRI, the MAC was significantly less (2.04 ± 0.11%) than the baseline MAC of isoflurane and significantly greater than the MAC during the CRI. In group 2, ketamine decreased isoflurane MAC (1.53 ± 0.22%) and the MAC increased significantly (1.94 ± 0.25%) after stopping the CRI. Minimum alveolar concentration (MAC) values did not differ significantly between the groups either during ketamine administration or after stopping ketamine. Under the study conditions, prior determination of the baseline isoflurane MAC did not alter the effect of ketamine on MAC. Both methods of determining MAC seemed to be valid for research purposes.

Gianotti, Giacomo; Valverde, Alexander; Sinclair, Melissa; Dyson, Doris H.; Gibson, Thomas; Johnson, Ron

2012-01-01

92

Influence of prior determination of baseline minimum alveolar concentration (MAC) of isoflurane on the effect of ketamine on MAC in dogs.  

PubMed

The objective of this study was to determine if prior measurement of the minimum alveolar concentration (MAC) of isoflurane influences the effect of ketamine on the MAC of isoflurane in dogs. Eight mixed-breed dogs were studied on 2 occasions. Anesthesia was induced and maintained using isoflurane. In group 1 the effect of ketamine on isoflurane MAC was determined after initially finding the baseline isoflurane MAC. In group 2, the effect of ketamine on isoflurane MAC was determined without previous measure of the baseline isoflurane MAC. In both groups, MAC was determined again 30 min after stopping the CRI of ketamine. Plasma ketamine concentrations were measured during MAC determinations. In group 1, baseline MAC (mean ± SD: 1.18 ± 0.14%) was decreased by ketamine (0.88 ± 0.14%; P < 0.05). The MAC after stopping ketamine was similar (1.09 ± 0.16%) to baseline MAC and higher than with ketamine (P < 0.05). In group 2, the MAC with ketamine (0.79 ± 0.11%) was also increased after stopping ketamine (1.10 ± 0.17%; P < 0.05). The MAC values with ketamine were different between groups (P < 0.05). Ketamine plasma concentrations were similar between groups during the events of MAC determination. The MAC of isoflurane during the CRI of ketamine yielded different results when methods of same day (group-1) versus separate days (group-2) are used, despite similar plasma ketamine concentrations with both methods. However, because the magnitude of this difference was less than 10%, either method of determining MAC is deemed acceptable for research purposes. PMID:24982552

Gianotti, Giacomo; Valverde, Alexander; Johnson, Ron; Sinclair, Melissa; Gibson, Thomas; Dyson, Doris H

2014-07-01

93

Solar Minimum  

NASA Astrophysics Data System (ADS)

Calcium K plage, H alpha plage and sunspot area have been monitored daily on the INTERNET since November of 1992. The plage and sunspot area have been measured by image processing. The purpose of the project is to investigate the degree of correlation between plage area and solar irradiance. The plage variation shows the expected variation produced by solar rotation and the longer secular changes produced by the solar cycle. The H alpha and sunspot plage area reached a minimum in about late 1994 or early 1995. This is in agreement with the K2 spectral index obtained daily from Sacramento Peak Observatory. The Calcium K plage area minimum seems delayed with respect to the others mentioned above. The minimum of the K line plage area is projected to come within the last few months of 1995.

Lopresto, James C.; Mathews, John; Manross, Kevin

1995-12-01

94

Combined porin loss and extended spectrum beta-lactamase production is associated with an increasing imipenem minimal inhibitory concentration in clinical Klebsiella pneumoniae strains.  

PubMed

For this study, 150 clinical isolates of Klebsiella pneumoniae were collected from one hospital in Beijing, China, and assayed for minimal inhibitory concentration (MIC) of imipenem. To elucidate the mechanisms responsible for imipenem MIC variation among extended-spectrum beta-lactamase (ESBL)-positive and -negative K. pneumoniae strains, a variety of beta-lactamase genes (bla(TEM), bla(CTX-M), bla(SHV), and bla(OXA)) were screened by polymerase chain reaction (PCR). The outer membrane profile and expression of related genes (ompK35 and ompK36) then were analyzed and evaluated, respectively. None of the tested isolates were clinically resistant to imipenem, but the range of MICs among ESBL-positive and -negative strains was significantly different. Deficiency in the expression of outer membrane proteins (OmpK35,36) was observed in some of both ESBL-positive(17.6%) and -negative strains (10.9%), but only the ESBL-positive strains depressed by the expression of ompK35/36 had an increased MIC of imipenem (>or=0.5 mg/l). These results confirmed that the combination of SHV-1, CTX-M-3, CTX-M-14, TEM-1, or OXA-11 production and reduced expression of ompK35/36 may not result in clinical resistance to imipenem but does correlate with increasing imipenem MIC. PMID:19219497

Yang, Duo; Guo, Yu; Zhang, Zheng

2009-04-01

95

Reduction of the minimum alveolar concentration of isoflurane in dogs using a constant rate of infusion of lidocaine-ketamine in combination with either morphine or fentanyl.  

PubMed

The objective of this study was to determine the effects of a constant rate of infusion of lidocaine and ketamine in combination with either morphine or fentanyl on the minimum alveolar concentration of isoflurane (MAC(ISO)) during ovariohysterectomy in dogs. Female dogs (n=44) were premedicated with acepromazine and midazolam. Anaesthesia was induced with propofol and maintained with isoflurane. Dogs received ketamine (0.6 mg/kg/h) and lidocaine (3 mg/kg/h) together with morphine (0.24 mg/kg/h; MLK) or fentanyl (0.0036 mg/kg/h; FLK). The control group received Ringer's lactate solution. A skin incision was used as the noxious stimulus. The MAC(ISO) value was obtained with Dixon's up-and-down method. MAC(ISO) was 0.7±0.0 vol.% in the control group, 0.3±0.0 vol.% in the MLK group (45% MAC reduction) and 0.0±0.0 vol.% in the FLK group (97% MAC reduction). A combination of fentanyl with lidocaine and ketamine decreased the MAC(ISO) in dogs; this decrease was more pronounced than that produced by morphine, lidocaine and ketamine. PMID:20594878

Aguado, Delia; Benito, Javier; Gómez de Segura, Ignacio A

2011-07-01

96

Neuroprotective doses of N-methyl-D-aspartate receptor antagonists profoundly reduce the minimum alveolar anesthetic concentration (MAC) for isoflurane in rats.  

PubMed

N-methyl-D-aspartate (NMDA) receptor antagonists, which block one of the glutamate receptors, have provided evidence of cerebral protection in animal models of focal cerebral ischemia. We examined the effect of neuroprotective doses of one noncompetitive (dizocilpine) and two competitive (D-CPP-ene, CGS 19755) NMDA antagonists on the minimum alveolar anesthetic concentration (MAC) of isoflurane in rats. A single bolus injection of any of the three NMDA antagonists produced a significant (P < 0.01) and sustained (> 3 h) decrease in the MAC of isoflurane. Dizocilpine decreased MAC by 33%-38% at a dose of 0.15 mg/kg and 48%-54% at a dose of 0.5 mg/kg. D-CPP-ene decreased MAC by 32%-37% at a dose of 1.5 mg/kg and 39%-45% at a dose of 4.5 mg/kg. CGS 19755 decreased MAC by 19%-24% at a dose of 3 mg/kg and 49%-58% at a dose of 10 mg/kg. Dizocilpine, but not the competitive antagonists, produced a small transient decrease in mean arterial blood pressure. The sustained anesthetic potency of neuroprotective doses of NMDA antagonists supports the idea that glutaminergic receptor activity is involved in determining the anesthetic state. PMID:8214668

Kuroda, Y; Strebel, S; Rafferty, C; Bullock, R

1993-10-01

97

Anesthesia with Isoflurane and Sevoflurane in the Crested Serpent Eagle (Spilornis cheela hoya): Minimum Anesthetic Concentration, Physiological Effects, Hematocrit, Plasma Chemistry and Behavioral Effects  

PubMed Central

ABSTRACT The initial goal of this study was to determine the minimum anesthetic concentration (MAC) for isoflurane (ISO) and sevoflurane (SEVO) for the crested serpent eagle. Next, we compared the anesthetic effects of each on the physiological effects, hematocrit, plasma chemistry values and behavior in spontaneously breathing captive adult crested serpent eagles. Sixteen eagles were randomly allocated to two groups for anesthesia with ISO (n=8) or SEVO (n=8). First, we measured the MAC values of ISO and SEVO, and four weeks later, we investigated the effect of each on the physiological effects, hematocrit (HCT) and plasma chemistry values. The MAC values of ISO and SEVO for crested serpent eagles were 1.46 ± 0.30 and 2.03 ± 0.32%, respectively. The results revealed no significant differences between the two anesthetics in induction time, while time of extubation to recovery was significantly shorter with SEVO. A time-related increase in end-tidal CO2 and decreases in body temperature and respiratory rates were observed during anesthesia with each anesthetic. There were no significant differences between the effect of the two anesthetics on heart rate, hematocrit, plasma chemistry values or respiration, although each caused minor respiration depression. We concluded that SEVO is a more effective inhalant agent than ISO for use in eagles, showing the most rapidest induction and recovery from anesthesia.

CHAN, Fang-Tse; CHANG, Geng-Ruei; WANG, Hsien-Chi; HSU, Tien-Huan

2013-01-01

98

Inhibition of spinal protein kinase C-epsilon or -gamma isozymes does not affect halothane minimum alveolar anesthetic concentration in rats.  

PubMed

Anesthetic effects on receptor or ion channel phosphorylation by enzymes such as protein kinase C (PKC) have been postulated to underlie some aspects of anesthesia. In vitro studies show that anesthetic effects on several receptors are mediated by PKC. To test the importance of PKC for the immobility produced by inhaled anesthetics, we measured the effect of intrathecal injections of PKC-epsilon and -gamma inhibitors on halothane minimum alveolar anesthetic concentration (MAC) in 7-day-old and 21-day-old Sprague-Dawley rats. The inhibitors were made as solutions of 100 pmol/5 microL and were given in a volume of 5 microL (7-day-old [P7] rats) or 10 microL (21-day-old [P21] rats). Controls were saline injections or injections of the peptide carrier at the same concentration and volumes; there were six animals in each group. In P7 rats, MAC values (in percentage of an atmosphere) were 1.63 +/- 0.0727 (mean +/- SEM) in saline controls, 1.55 +/- 0.141 in carrier controls, 1.54 +/- 0.0800 in rats given PKC-epsilon, and 1.69 +/- 0.0554 in rats given PKC-gamma. In P21 animals, the values were 1.20 +/- 0.0490, 1.31 +/- 0.0124, 1.27 +/- 0.0367, and 1.15 +/- 0.0483, respectively. Injection of the inhibitors did not change MAC in either age group. These results do not support an anesthetic effect on phosphorylation as a mechanism underlying the capacity of inhaled anesthetics to prevent movement in response to noxious stimulation, and they indirectly support a direct action on receptors or ion channels. PMID:15281508

Shumilla, Jennifer A; Sweitzer, Sarah M; Eger, Edmond I; Laster, Michael J; Kendig, Joan J

2004-07-01

99

Concentration  

NSDL National Science Digital Library

Watch your solution change color as you mix chemicals with water. Then check molarity with the concentration meter. What are all the ways you can change the concentration of your solution? Switch solutes to compare different chemicals and find out how concentrated you can go before you hit saturation!

Simulations, Phet I.; Chamberlain, Julia; Malley, Chris; Lancaster, Kelly; Moore, Emily B.; Perkins, Kathy

2012-03-09

100

Trough plasma concentration of imatinib reflects BCR-ABL kinase inhibitory activity and clinical response in chronic-phase chronic myeloid leukemia: a report from the BINGO study.  

PubMed

Pharmacokinetic (PK) factors have been suggested to be involved in the unfavorable clinical responses of chronic myeloid leukemia (CML) patients treated with imatinib. The purpose of this study was to clarify prognostic implications of PK factors in CML patients treated with imatinib. The plasma trough (C(min)) level of imatinib and serum ?(1)-acid glycoprotein (AGP) level were measured on two different days in 65 CML patients treated with imatinib for more than 12 months. We further examined whether the C(min) level of imatinib actually reflects inhibitory activity against BCR-ABL kinase using the plasma inhibitory activity (PIA) assay. Since the differences of five patients were statistically rejected by the Smirnov-Grubbs' test, we excluded them for further analysis. The C(min) level was strongly associated with the achievement of MMR at the 12th month, and ROC analysis demonstrated C(min) levels and their discrimination potential for major molecular response (MMR) with the best sensitivity (63.2%) and specificity (68.2%) at a C(min) threshold of 974 ng/mL. The ?(1)-Acid glycoprotein (AGP) level was within the normal range in 57 of 60 patients, indicating little impact of AGP on our study. There was a weak correlation between PIA against phospho (P)-BCR-ABL and the C(min) level of imatinib (r(2) = 0.2501, P = 0.0007), and patient plasma containing >974 ng/mL imatinib sufficiently inhibited P-BCR-ABL. These results collectively indicated that maintaining ?1000 ng/mL of C(min) was clinically and biologically important for the optimal response in CML patients treated with imatinib. A prospective intervention study is required to establish PK-based management in CML patients treated with imatinib. PMID:20608939

Ishikawa, Yuichi; Kiyoi, Hitoshi; Watanabe, Keisuke; Miyamura, Koichi; Nakano, Yasuyuki; Kitamura, Kunio; Kohno, Akio; Sugiura, Isamu; Yokozawa, Toshiya; Hanamura, Akitoshi; Yamamoto, Kazuhito; Iida, Hiroatsu; Emi, Nobuhiko; Suzuki, Ritsuro; Ohnishi, Kazunori; Naoe, Tomoki

2010-10-01

101

Inhibitory effect of silicon nanowires on the polymerase chain reaction.  

PubMed

The effect of nanomaterials on biological reactions has received much attention. We report herein that silicon nanowires (SiNWs) inhibit the polymerase chain reaction (PCR). The inhibitory effect was found to be concentration-dependent, with a minimum inhibitory concentration of about 0.4 mg ml(-1). DNA polymerase, restriction endonucleases, lysozyme and horseradish peroxidase maintained their bioactivities after exposure to SiNWs. Also the interaction of SiNWs with primers and dNTP did not lead to decreased PCR yield. Compared to primers and dNTP, template DNA showed 4.7-10.5-fold greater adsorption on SiNWs. Template bound to SiNWs was ineffective in the PCR, whereas addition of free template to the PCR system increased the yield. The results of this work suggest that the inhibitory effect of SiNWs on the PCR was due to the selective adsorption of double-stranded DNA on SiNWs, thereby decreasing the availability of template for the reaction. PMID:22914382

Wang, Hongwei; Wang, Lei; Yuan, Lin; Yang, Weikang; Brash, John L; Chen, Hong

2012-09-14

102

Comparison of minimal inhibitory and mutant prevention drug concentrations of 4 fluoroquinolones against clinical isolates of methicillin-susceptible and -resistant Staphylococcus aureus  

Microsoft Academic Search

Staphylococcus aureus remains an important human pathogen affecting both outpatients and those hospitalized. Increasing antimicrobial resistance is global but prevalence rates are variable for different geographical areas. Fluoroquinolones have been used to treat S. aureus infections and the newer quinolones have enhanced in vitro activity against this organism. The mutant prevention concentration (MPC) defines the antimicrobial drug concentration threshold that

K. Metzler; G. M. Hansen; Peter Hedlin; Elizabeth Harding; Karl Drlica; J. M. Blondeau

2004-01-01

103

Concentration-Dependent Inhibitory Effect of Baicalin on the Plasma Protein Binding and Metabolism of Chlorzoxazone, a CYP2E1 Probe Substrate, in Rats In Vitro and In Vivo  

PubMed Central

Some of the components found in herbs may be inhibitors or inducers of cytochrome P450 enzymes, which may therefore result in undesired herb-drug interactions. As a component extracted from Radix Scutellariae, the direct effect of baicalin on cytochrome P450 has not been investigated sufficiently. In this study, we investigated concentration-dependent inhibitory effect of baicalin on the plasma protein binding and metabolism of chlorzoxazone (CZN), a model CYP2E1 probe substrate, in rats in vitro and in vivo. Animal experiment was a randomized, three-period crossover design. Significant changes in pharmacokinetic parameters of CZN such as Cmax, t1/2 and Vd were observed after treatment with baicalin in vivo (P<0.05). Cmax decreased by 25% and 33%, whereas t1/2 increased by 34% and 53%, Vd increased by 37% and 50% in 225 mg/kg and 450 mg/kg baicalin-treated rats, respectively. The AUC and CL of CZN were not affected (P>0.05). Correlation analysis showed that the changes in CZN concentrations and baicalin concentrations were in good correlation (r>0.99). In vitro experiments, baicalin decreased the formation of 6-OH-chlorzoxazone in a concentration-dependent manner and exhibited a competitive inhibition in rat liver microsomes, with a Ki value of 145.8 µM. The values of Cmax/Ki were 20 and 39 after treatment with baicalin (225 and 450 mg/kg), respectively. Protein binding experiments in vivo showed that the plasma free-fraction (fu) of CZN increased 2.6-fold immediately after baicalin treatment (450 mg/kg) and in vitro showed that baicalin (125–2500 mg/L) increased the unbound CZN from 1.63% to 3.58%. The results indicate that pharmacokinetic changes in CZN are induced by inhibitory effect of baicalin on the plasma protein binding of CZN and CYP2E1 activity.

Gao, Na; Zou, Dan; Qiao, Hai-Ling

2013-01-01

104

Determination of Fifty Percent Inhibitory Concentrations (IC50) of Antimalarial Drugs Against Plasmodium Falciparum Parasites in a Serum-Free Medium.  

National Technical Information Service (NTIS)

Plasmodium falciparum chemosensitivity to the various antimalarial drugs is presently determined in the laboratory by setting up multiple microcultures of the parasite and estimating the amount of growth inhibition caused by known concentrations of drug. ...

A. O. Ofulla A. S. Orago J. I. Githure J. P. Burans G. M. Aleman

1994-01-01

105

Concentration  

NSDL National Science Digital Library

This NCTM iOS app of the familiar online Illuminations game, "Concentration" (cataloged separately) challenges a user to match whole numbers, shapes, fractions, or multiplication facts to equivalent representations. This game can be played by one or two players taking turns and can be played in clear pane mode, or for added challenge, with the windows closed.

2011-09-15

106

Concentration  

NSDL National Science Digital Library

This is the NCTM Android app of their familiar on line Illuminations game, "Concentration" ( cataloged separately ) which challenges a user to match whole numbers, shapes, fractions, or multiplication facts to equivalent representations. This game can be played by one or two players taking turns and can be played in clear pane mode, or for added challenge, with the windows closed.

2011-08-11

107

Effects of sub-lethal neurite outgrowth inhibitory concentrations of chlorpyrifos oxon on cytoskeletal proteins and acetylcholinesterase in differentiating N2a cells  

SciTech Connect

Previous work in our laboratory has shown that sub-lethal concentrations (1-10 {mu}M) of chlorpyrifos (CPF), diazinon (DZ) and diazinon oxon (DZO) inhibit the outgrowth of axon-like neurites in differentiating mouse N2a neuroblastoma cells concomitant with altered levels and/or phosphorylation state of axonal cytoskeleton and growth-associated proteins. The aim of the present work was to determine whether chlorpyrifos oxon (CPO) was capable of inhibiting N2a cell differentiation in a similar manner. Using experimental conditions similar to our previous work, sub-lethal concentrations (1-10 {mu}M) of CPO were found to inhibit N2a cell differentiation. However, unlike previous studies with DZ and DZO, there was a high level of sustained inhibition of acetylcholinesterase (AChE) in CPO treated cells. Impairment of neurite outgrowth was also associated with reduced levels of growth associated protein-43 and neurofilament heavy chain (NFH), and the distribution of NFH in cells stained by indirect immunofluorescence was disrupted. However, in contrast to previous findings for DZO, the absolute level of phosphorylated NFH was unaffected by CPO exposure. Taken together, the findings suggest that sub-lethal concentrations of CPO inhibit axon outgrowth in differentiating N2a cells and that this effect involves reduced levels of two proteins that play key roles in axon outgrowth and maintenance. Although the inhibition of neurite outgrowth is unlikely to involve AChE inhibition directly, further work will help to determine whether the persistent inhibition of AChE by CPO can account for the different effects induced by CPO and DZO on the levels of total and phosphorylated NFH. -- Highlights: Black-Right-Pointing-Pointer Sub-lethal levels of chlorpyrifos oxon inhibit neurite outgrowth in N2a cells Black-Right-Pointing-Pointer Acetylcholinesterase exhibits sustained inhibition throughout exposure Black-Right-Pointing-Pointer The levels of neurofilament heavy chain and GAP-43 protein are reduced Black-Right-Pointing-Pointer Neurofilament heavy chain forms aggregates in cell bodies Black-Right-Pointing-Pointer Thus at least two axon-associated cytoskeletal proteins are disrupted by this agent.

Flaskos, J., E-mail: flaskos@vet.auth.gr [Laboratory of Biochemistry and Toxicology, School of Veterinary Medicine, Aristotle University of Thessaloniki, 54124 Thessaloniki (Greece); Nikolaidis, E. [Laboratory of Biochemistry and Toxicology, School of Veterinary Medicine, Aristotle University of Thessaloniki, 54124 Thessaloniki (Greece)] [Laboratory of Biochemistry and Toxicology, School of Veterinary Medicine, Aristotle University of Thessaloniki, 54124 Thessaloniki (Greece); Harris, W. [School of Science and Technology, Nottingham Trent University, Clifton Lane, Nottingham NG11 8NS (United Kingdom)] [School of Science and Technology, Nottingham Trent University, Clifton Lane, Nottingham NG11 8NS (United Kingdom); Sachana, M. [Laboratory of Biochemistry and Toxicology, School of Veterinary Medicine, Aristotle University of Thessaloniki, 54124 Thessaloniki (Greece)] [Laboratory of Biochemistry and Toxicology, School of Veterinary Medicine, Aristotle University of Thessaloniki, 54124 Thessaloniki (Greece); Hargreaves, A.J., E-mail: alan.hargreaves@ntu.ac.uk [School of Science and Technology, Nottingham Trent University, Clifton Lane, Nottingham NG11 8NS (United Kingdom)

2011-11-15

108

Evaluating Minimum Aptitude Standards.  

National Technical Information Service (NTIS)

The evaluation of aptitude standards to determine qualification into military specialties must address issues concerning both the minimum qualifying score and the appropriate aptitude distribution above that minimum. This research memorandum is an initial...

M. H. Maier P. W. Mayberry

1989-01-01

109

Minimum complexity density estimation  

Microsoft Academic Search

The authors introduce an index of resolvability that is proved to bound the rate of convergence of minimum complexity density estimators as well as the information-theoretic redundancy of the corresponding total description length. The results on the index of resolvability demonstrate the statistical effectiveness of the minimum description-length principle as a method of inference. The minimum complexity estimator converges to

Andrew R. Barron; Thomas M. Cover

1991-01-01

110

Analysis of minimum zone sphericity error using minimum potential energy theory  

Microsoft Academic Search

Theoretical derivation of the minimum zone criteria of sphericity error based on the principle of minimum potential energy is proposed. All the measured data points are enclosed by two concentric spherical surfaces between which a fictitious spring is assumed to be placed. These two concentric spherical surfaces can be mathematically determined by five active data points. When the spring contracts,

Kuang-Chao Fana; Ji-Chun Lee

1999-01-01

111

Moxalactam concentrations in human prostatic tissue.  

PubMed Central

The concentrations of moxalactam in human prostatic tissue, obtained by enucleation or transurethral resection, were measured in 10 patients after the intramuscular administration of two 500-mg doses. The average concentrations of moxalactam in prostatic tissue in the enucleated and transurethral resection specimens were 4.0 micrograms/g and 5.2 micrograms/ml, and the ratios of the moxalactam concentrations in prostate to those in plasma were 0.24 and 0.31, respectively. The concentrations of moxalactam achieved in prostatic tissue after the administration of relatively low doses were greater than the minimum inhibitory concentrations of moxalactam for most common gram-negative pathogens. Concentrations of moxalactam in carefully obtained transurethral resection specimens were similar to those found in the enucleated specimens.

Smith, R P; Wilbur, H; Sutphen, N T; Baltch, A L

1983-01-01

112

Minimum Entropy Orientations  

Microsoft Academic Search

We study graph orientations that minimize the entropy of the in-degree\\u000asequence. The problem of finding such an orientation is an interesting special\\u000acase of the minimum entropy set cover problem previously studied by Halperin\\u000aand Karp [Theoret. Comput. Sci., 2005] and by the current authors\\u000a[Algorithmica, to appear]. We prove that the minimum entropy orientation\\u000aproblem is NP-hard even

Jean Cardinal; Samuel Fiorini; Gwenaël Joret

2008-01-01

113

Minimum time trajectory planning  

Microsoft Academic Search

An algorithm for determining the minimum time trajectory (path and velocity along that path) for a robot arm with actuator constraints is presented. The method combines the control theory and the exhaustive search approaches to yield an algorithm that is faster than either approach. The method consists of first parameterizing the path in the configuration space, then, given a path,

V. T. Rajan

1985-01-01

114

Minimum emissions power flow  

Microsoft Academic Search

A formulation of the optimal power flow problem to include the minimum emission objective is presented in this paper. Fuel cost and emissions such as NOx objectives are included in the formulation. Emissions can also be included as constraints. The trade-off relation between fuel cost and emissions is also studied in this paper. Optimizing the objective for a whole period

J. H. Talaq; F. El-Hawary; M. E. El-Hawary

1994-01-01

115

Minimum School Space Requirements.  

ERIC Educational Resources Information Center

This document presents methods for determining minimum school space requirements for Arizona public school classrooms; libraries and media centers; cafeterias; auditoriums and other multiuse space; science, art, vocational education, and physical education space; and non-educational areas. The space requirements are based on the following…

Arizona State School Facilities Board, Phoenix.

116

Effects of fenamate on inhibitory postsynaptic currents in Purkinje's cells.  

PubMed

The effects of nonsteroid antiinflammatory drugs of the fenamate group (mefenamic and tolfenamic acids) on spontaneous miniature inhibitory postsynaptic currents in Purkinje's cells were studied in mouse cerebellar slices by the whole cell patch-clamp method. Both drugs in concentrations of 3-30 microM significantly prolonged miniature inhibitory postsynaptic currents and reduced their amplitude. PMID:19145282

Dvorzhak, A Yu

2008-05-01

117

Ceftizoxime concentrations in human aqueous humor following intravenous administration.  

PubMed

The aqueous humor penetration of the third-generation cephalosporin, ceftizoxime, was determined in 21 patients awaiting cataract extraction, after an intravenous bolus injection of 2 g. The beta-lactam compound achieved a mean peak aqueous humor concentration of 7.8 mg/l two hours after administration with a serum/humor percent ratio ranging between 7 and 16% during the four-hour sampling interval. Therefore, ceftizoxime levels in this extravascular fluid were above the minimum inhibitory concentrations for the majority of sensitive organisms. PMID:3224400

Martinelli, D; Mazzei, T; Fallani, S; Palendri, G; Novelli, A; Periti, P

1988-10-01

118

Minimum-scattering superabsorbers  

NASA Astrophysics Data System (ADS)

Absorption and scattering are inherently related, as it is not possible to absorb power without creating a far-field shadow. We show, however, that properly overlapped resonant modes in a suitably designed system may in principle lead to arbitrarily large absorption levels, while at the same time minimizing the total scattering. We discuss the fundamental limits on scattering and absorption of an arbitrary receiving system and envision a composite nanoparticle that demonstrates the concept of a minimum-scattering superabsorber, with potential applications in energy harvesting, sensing, and imaging.

Mohammadi Estakhri, Nasim; Ali, Andrea

2014-03-01

119

Minimum fuel mode evaluation  

NASA Technical Reports Server (NTRS)

The minimum fuel mode of the NASA F-15 research aircraft is designed to minimize fuel flow while maintaining constant net propulsive force (FNP), effectively reducing thrust specific fuel consumption (TSFC), during cruise flight conditions. The test maneuvers were at stabilized flight conditions. The aircraft test engine was allowed to stabilize at the cruise conditions before data collection initiated; data were then recorded with performance seeking control (PSC) not-engaged, then data were recorded with the PSC system engaged. The maneuvers were flown back-to-back to allow for direct comparisons by minimizing the effects of variations in the test day conditions. The minimum fuel mode was evaluated at subsonic and supersonic Mach numbers and focused on three altitudes: 15,000; 30,000; and 45,000 feet. Flight data were collected for part, military, partial, and maximum afterburning power conditions. The TSFC savings at supersonic Mach numbers, ranging from approximately 4% to nearly 10%, are in general much larger than at subsonic Mach numbers because of PSC trims to the afterburner.

Orme, John S.; Nobbs, Steven G.

1995-01-01

120

Inhibitory effects of urine on the polymerase chain reaction for cytomegalovirus DNA  

Microsoft Academic Search

The inhibitory effects of urine samples taken from neonates and older children, some of which were known to be infected with cytomegalovirus, on the polymerase chain reaction (PCR) were investigated. Urea was the major inhibitory component of urine and inhibited the PCR at a concentration of more than 50 mM. Urine samples from older children were more inhibitory than those

G Khan; H O Kangro; P J Coates; R B Heath

1991-01-01

121

Minimum Uncertainty and Entanglement  

NASA Astrophysics Data System (ADS)

We address the question, does a system A being entangled with another system B, put any constraints on the Heisenberg uncertainty relation (or the Schrödinger-Robertson inequality)? We find that the equality of the uncertainty relation cannot be reached for any two noncommuting observables, for finite dimensional Hilbert spaces if the Schmidt rank of the entangled state is maximal. One consequence is that the lower bound of the uncertainty relation can never be attained for any two observables for qubits, if the state is entangled. For infinite-dimensional Hilbert space too, we show that there is a class of physically interesting entangled states for which no two noncommuting observables can attain the minimum uncertainty equality.

Hari Dass, N. D.; Qureshi, Tabish; Sheel, Aditi

2013-06-01

122

Selection of antibiotic resistance at very low antibiotic concentrations.  

PubMed

Abstract Human use of antibiotics has driven the selective enrichment of pathogenic bacteria resistant to clinically used drugs. Traditionally, the selection of resistance has been considered to occur mainly at high, therapeutic levels of antibiotics, but we are now beginning to understand better the importance of selection of resistance at low levels of antibiotics. The concentration of an antibiotic varies in different body compartments during treatment, and low concentrations of antibiotics are found in sewage water, soils, and many water environments due to natural production and contamination from human activities. Selection of resistance at non-lethal antibiotic concentrations (below the wild-type minimum inhibitory concentration) occurs due to differences in growth rate at the particular antibiotic concentration between cells with different tolerance levels to the antibiotic. The minimum selective concentration for a particular antibiotic is reached when its reducing effect on growth of the susceptible strain balances the reducing effect (fitness cost) of the resistance determinant in the resistant strain. Recent studies have shown that resistant bacteria can be selected at concentrations several hundred-fold below the lethal concentrations for susceptible cells. Resistant mutants selected at low antibiotic concentrations are generally more fit than those selected at high concentrations but can still be highly resistant. The characteristics of selection at low antibiotic concentrations, the potential clinical problems of this mode of selection, and potential solutions will be discussed. PMID:24694026

Sandegren, Linus

2014-05-01

123

Selection of antibiotic resistance at very low antibiotic concentrations  

PubMed Central

Human use of antibiotics has driven the selective enrichment of pathogenic bacteria resistant to clinically used drugs. Traditionally, the selection of resistance has been considered to occur mainly at high, therapeutic levels of antibiotics, but we are now beginning to understand better the importance of selection of resistance at low levels of antibiotics. The concentration of an antibiotic varies in different body compartments during treatment, and low concentrations of antibiotics are found in sewage water, soils, and many water environments due to natural production and contamination from human activities. Selection of resistance at non-lethal antibiotic concentrations (below the wild-type minimum inhibitory concentration) occurs due to differences in growth rate at the particular antibiotic concentration between cells with different tolerance levels to the antibiotic. The minimum selective concentration for a particular antibiotic is reached when its reducing effect on growth of the susceptible strain balances the reducing effect (fitness cost) of the resistance determinant in the resistant strain. Recent studies have shown that resistant bacteria can be selected at concentrations several hundred-fold below the lethal concentrations for susceptible cells. Resistant mutants selected at low antibiotic concentrations are generally more fit than those selected at high concentrations but can still be highly resistant. The characteristics of selection at low antibiotic concentrations, the potential clinical problems of this mode of selection, and potential solutions will be discussed.

2014-01-01

124

Fictitious Inhibitory Differences  

PubMed Central

The stop-signal paradigm is a popular method for examining response inhibition and impulse control in psychology, cognitive neuroscience, and clinical domains because it allows the estimation of the covert latency of the stop process: the stop-signal reaction time (SSRT). In three sets of simulations, we examined to what extent SSRTs that were estimated with the popular mean and integration methods were influenced by the skew of the reaction time distribution and the gradual slowing of the response latencies. We found that the mean method consistently overestimated SSRT. The integration method tended to underestimate SSRT when response latencies gradually increased. This underestimation bias was absent when SSRTs were estimated with the integration method for smaller blocks of trials. Thus, skewing and response slowing can lead to spurious inhibitory differences. We recommend that the mean method of estimating SSRT be abandoned in favor of the integration method.

Chambers, Christopher D.; Logan, Gordon D.

2013-01-01

125

Inhibitory Effects of Brown Algae Extracts on Histamine Production in Mackerel Muscle via Inhibition of Growth and Histidine Decarboxylase Activity of Morganella morganii.  

PubMed

This study was performed to investigate the inhibitory effects of brown algae extracts on histamine production in mackerel muscle. First, antimicrobial activities of brown algae extracts against Morganella morganii were investigated using a disk diffusion method. An ethanol extract of Ecklonia cava (ECEE) exhibited strong antimicrobial activity. The minimum inhibitory concentration (MIC) of ECEE was 2 mg/ml. Furthermore, the brown algae extracts were examined for their ability to inhibit crude histidine decarboxylase (HDC) of M. morganii. The ethanol extract of Eisenia bicyclis (EBEE) and ECEE exhibited significant inhibitory activities (19.82% and 33.79%, respectively) at a concentration of 1 mg/ml. To obtain the phlorotannin dieckol, ECEE and EBEE were subjected to liquid-liquid extraction, silica gel column chromatography, and HPLC. Dieckol exhibited substantial inhibitory activity with an IC50 value of 0.61 mg/ml, and exhibited competitive inhibition. These extracts were also tested on mackerel muscle. The viable cell counts and histamine production in mackerel muscle inoculated with M. morganii treated with ?2.5 MIC of ECEE (weight basis) were highly inhibited compared with the untreated sample. Furthermore, treatment of crude HDCinoculated mackerel muscle with 0.5% ECEE and 0.5% EBEE (weight basis), which exhibited excellent inhibitory activities against crude HDC, reduced the overall histamine production by 46.29% and 56.89%, respectively, compared with the untreated sample. Thus, these inhibitory effects of ECEE and EBEE should be helpful in enhancing the safety of mackerel by suppressing histamine production in this fish species. PMID:24394193

Kim, Dong Hyun; Kim, Koth Bong Woo Ri; Cho, Ji Young; Ahn, Dong Hyun

2014-04-28

126

Social Security's special minimum benefit.  

PubMed

Social Security's special minimum primary insurance amount (PIA) provision was enacted in 1972 to increase the adequacy of benefits for regular long-term, low-earning covered workers and their dependents or survivors. At the time, Social Security also had a regular minimum benefit provision for persons with low lifetime average earnings and their families. Concerns were rising that the low lifetime average earnings of many regular minimum beneficiaries resulted from sporadic attachment to the covered workforce rather than from low wages. The special minimum benefit was seen as a way to reward regular, low-earning workers without providing the windfalls that would have resulted from raising the regular minimum benefit to a much higher level. The regular minimum benefit was subsequently eliminated for workers reaching age 62, becoming disabled, or dying after 1981. Under current law, the special minimum benefit will phase out over time, although it is not clear from the legislative history that this was Congress's explicit intent. The phaseout results from two factors: (1) special minimum benefits are paid only if they are higher than benefits payable under the regular PIA formula, and (2) the value of the regular PIA formula, which is indexed to wages before benefit eligibility, has increased faster than that of the special minimum PIA, which is indexed to inflation. Under the Social Security Trustees' 2000 intermediate assumptions, the special minimum benefit will cease to be payable to retired workers attaining eligibility in 2013 and later. Their benefits will always be larger under the regular benefit formula. As policymakers consider Social Security solvency initiatives--particularly proposals that would reduce benefits or introduce investment risk--interest may increase in restoring some type of special minimum benefit as a targeted protection for long-term low earners. Two of the three reform proposals offered by the President's Commission to Strengthen Social Security would modify and strengthen the current-law special minimum benefit. Interest in the special minimum benefit may also increase because of labor force participation and marital trends that suggest that enhancing workers' benefits may be a more effective means of reducing older women's poverty rates than enhancing spousal or widow's benefits. By understanding the Social Security program's experience with the special minimum benefit, policymakers will be able to better anticipate the effectiveness of other initiatives to enhance benefits for long-term low earners. This article presents the most recent and comprehensive information available about the special minimum benefit in order to help policymakers make informed decisions about the provision's future. Highlights of the current special minimum benefit include the following: Very few persons receive the special minimum benefit. As of December 2001, about 134,000 workers and their dependents and survivors were entitled to a benefit based on the special minimum. Of those, only about 79,000 received a higher total benefit because of the special minimum; the other 55,000 were dually entitled. (In effect, when persons are eligible for more than one type of benefit--that is, they are dually eligible--the highest benefit payable determines total benefits. If the special minimum benefit is not the highest benefit payable, it does not increase total benefits paid.) As of February 2000, retired workers who were special minimum beneficiaries with unreduced benefits and were not dually entitled were receiving, on average, a monthly benefit of $510 per month. That amount is approximately $2,000 less than the annual poverty threshold for an aged individual. Special minimum benefits provide small increases in total benefits. For special minimum beneficiaries who were not dually entitled as of December 2001, the average special minimum monthly PIA was just $39 higher than the regular PIA. Most special minimum beneficiaries are female retired workers. About 90 percent of special minimum beneficiaries are retired work

Olsen, K A; Hoffmeyer, D

127

Promotion and computation of inhibitory effect on tyrosinase activity of herbal cream by incorporating indigenous medicinal plants.  

PubMed

Herbal cream imparts a chief role in regulating melanin production of skin. The phytoconstituents present in herbal cream impact biological functions of skin and contribute nutrients required for the healthy skin. In the present study, it was envisaged to prepare three batches of herbal cream (HC1, HC2 and HC3) containing ethanol extracts of Emblica officinalis (fruits), Daucus carota (root), Mangifera indica (leaves), Mentha arvensis (leaves), Terminalia arjuna (bark) and Cucumis sativus (fruits) and investigated the prepared cream for inhibitory effect on tyrosinase activity. The herbal cream was formulated by incorporating different ratio of extracts, by using cream base. Each formulation HC1, HC2 and HC3 were segregated into three different formulations (HC1.1, HC1.2, HC1.3, HC2.1, HC2.2, HC2.3, HC3.1, HC3.2 and HC3.3) by incorporating increasing ratio of extract in formulation. The HC3.2 cream produces highest tyrosinase inhibitory effect 65.23 +/- 0.07%, while the HC2.1 exhibited minimum tyrosinase inhibitory effect 26.19 +/- 0.08% compared to other prepared cream. Comparison of the inhibitory activity of the formulations demonstrated that the rank order was HC3.2 > HC3.3 > HC1.2 > HC1.3 > HC3.1 > HC1.1 > HC2.3 > HC2.2 > HC2.1. It has been observed from the result that the formulations of antityrosinase activity were not concentrate dependent. This finding suggests that decrease in antityrosinase activity of HC1 and HC3 might be considering that the incompatibility of the higher extract content with the base of cream. The HC3 produce the maximum inhibitory effects on tyrosinase activity might be due to higher level of polyphenol and flavonoids present in extracts. PMID:24783796

Sahu, Ram Kumar; Roy, Amit; Dwivedi, Jaya; Jha, Arvind Kumar

2014-01-01

128

Monoamine oxidase inhibitory coumarin from Zanthoxylum schinifolium.  

PubMed

A methanol extract of Zanthoxylum schinifolium stems at a concentration of 250 microg/ml showed potent inhibitory activity against monoamine oxidase (MAO) in a mouse brain. Activity-guided separation and purification of the extract yielded lacinartin (1) as an active coumarin compound. Lacinartin showed significant inhibitory effects on MAO in a dose-dependent manner. The IC(50) value on MAO activity was 9.2 microM. The MAO-A (IC(50) value, 5.7 microM) sensitivity to lacinartin was greater than that of MAO-B (IC(50) value, 28.6 microM). An enzyme kinetic study revealed that lacinartin inhibited MAO activity by a non-competitive mode. PMID:11842339

Jo, Young Su; Huong, Dang Thi Lan; Bae, KiHwan; Lee, Myung Koo; Kim, Young Ho

2002-01-01

129

Inhibitory activity of papain on facultative pathogens--short communication.  

PubMed

Papain, a proteolytic enzyme obtained from papaya was found inhibitory on few facultative pathogens. While Escherichia coli, Staphylococcus albus, Klebsiella pneumoniae and Enterobacter cloacae were inhibited at concentration from 200 ppm on the cell density of Staphylococcus faecalis decreased only at higher concentration of papain (400-800 ppm). PMID:2124762

Rajashekhara, E; Tippannavar, C M; Sreenivasa, M N; Sharma, J S

1990-01-01

130

Synapse-Specific Inhibitory Control of Hippocampal Feedback Inhibitory Circuit  

PubMed Central

Local circuit and long-range GABAergic projections provide powerful inhibitory control over the operation of hippocampal inhibitory circuits, yet little is known about the input- and target-specific organization of interacting inhibitory networks in relation to their specific functions. Using a combination of two-photon laser scanning photostimulation and whole-cell patch clamp recordings in mice hippocampal slices, we examined the properties of transmission at GABAergic synapses formed onto hippocampal CA1 stratum oriens – lacunosum moleculare (O–LM) interneurons by two major inhibitory inputs: local projection originating from stratum radiatum interneurons and septohippocampal GABAergic terminals. Optical mapping of local inhibitory inputs to O–LM interneurons revealed that vasoactive intestinal polypeptide- and calretinin-positive neurons, with anatomical properties typical of type III interneuron-specific interneurons, provided the major local source of inhibition to O–LM cells. Inhibitory postsynaptic currents evoked by minimal stimulation of this input exhibited small amplitude and significant paired-pulse and multiple-pulse depression during repetitive activity. Moreover, these synapses failed to show any form of long-term synaptic plasticity. In contrast, synapses formed by septohippocampal projection produced higher amplitude and persistent inhibition and exhibited long-term potentiation induced by theta-like activity. These results indicate the input and target-specific segregation in inhibitory control, exerted by two types of GABAergic projections and responsible for distinct dynamics of inhibition in O–LM interneurons. The two inputs are therefore likely to support the differential activity- and brain state-dependent recruitment of hippocampal feedback inhibitory circuits in vivo, crucial for dendritic disinhibition and computations in CA1 pyramidal cells.

Chamberland, Simon; Salesse, Charleen; Topolnik, Dimitry; Topolnik, Lisa

2010-01-01

131

Angiotensin I converting enzyme inhibitory peptide extracted from freshwater zooplankton.  

PubMed

In this study, hydrolysates obtained from the freshwater rotifer Brachionus calyciflonus were investigated for angiotensin I converting enzyme (ACE) inhibitory peptides. Freshwater rotifer protein was hydrolyzed using six separate enzymes in a batch reactor. The peptic hydrolysate had the highest ACE inhibitory activity compared to the other hydrolysates. The highest ACE inhibitory peptide was separated using Sephadex G-25 column chromatography and high-performance liquid chromatography on a C18 column. The 50% inhibitory concentration (IC(50)) value of purified ACE inhibitory peptide was 40.01 microg/mL. ACE inhibitory peptide was identified as being seven amino acid residues of Ala-Gln-Gly-Glu-Arg-His-Arg by N-terminal amino acid sequence analysis. The IC(50) value of purified ACE inhibitory peptide was 47.1 microM, and Lineweaver-Burk plots suggested that the peptide purified from rotifer protein acts as a competitive inhibitor against ACE. The results of this study suggest that peptides derived from freshwater rotifers may be beneficial as antihypertension compounds in functional foods or as pharmaceuticals. PMID:20170338

Lee, Jung Kwon; Lee, Min-Su; Park, Heum Gi; Kim, Se-Kwon; Byun, Hee-Guk

2010-04-01

132

Equivalence to the Minimum Qualifications  

ERIC Educational Resources Information Center

In 1988 the Community College Reform Act (AB 1725) began a phase out of credentials in favor of a process for establishing minimum qualifications and the determination of equivalencies that are at least equal to the state-adopted minimum qualifications for a particular discipline. According to Education Code sections 87359 and 87360, someone…

Academic Senate for California Community Colleges, 2006

2006-01-01

133

Effect of stiripentol on carbamazepine plasma concentration and metabolism in epileptic children  

Microsoft Academic Search

Objective: To study the relationship between the plasma concentration of stiripentol (STP), a new antiepileptic drug, and its inhibitory\\u000a effect on the formation of carbamazepine epoxide (CBZE) in epileptic children treated with carbamazepine (CBZ) either alone\\u000a or in combination with another antiepileptic drug.\\u000a \\u000a Methods:\\u000a \\u000a \\u000a Minimum plasma concentration of antiepileptic drugs was measured before initiation of STP therapy (day 0) and

A. Tran; F. Vauzelle-Kervroedan; E. Rey; G. Pons; Ph d’Athis; C. Chiron; O. Dulac; F. Renard; G. Olive

1996-01-01

134

In glucose-limited continuous culture the minimum substrate concentration for growth, smin, is crucial in the competition between the enterobacterium Escherichia coli and Chelatobacter heintzii, an environmentally abundant bacterium  

PubMed Central

The competition for glucose between Escherichia coli ML30, a typical copiotrophic enterobacterium and Chelatobacter heintzii ATCC29600, an environmentally successful strain, was studied in a carbon-limited culture at low dilution rates. First, as a base for modelling, the kinetic parameters ?max and Ks were determined for growth with glucose. For both strains, ?max was determined in batch culture after different precultivation conditions. In the case of C. heintzii, ?max was virtually independent of precultivation conditions. When inoculated into a glucose-excess batch culture medium from a glucose-limited chemostat run at a dilution rate of 0.075?h?1 C. heintzii grew immediately with a ?max of 0.17±0.03?h?1. After five transfers in batch culture, ?max had increased only slightly to 0.18±0.03?h?1. A different pattern was observed in the case of E. coli. Inoculated from a glucose-limited chemostat at D=0.075?h?1 into glucose-excess batch medium E. coli grew only after an acceleration phase of ?3.5?h with a ?max of 0.52?h?1. After 120 generations and several transfers into fresh medium, ?max had increased to 0.80±0.03?h?1. For long-term adapted chemostat-cultivated cells, a Ks for glucose of 15??g?l?1 for C. heintzii, and of 35??g?l?1 for E. coli, respectively, was determined in 14C-labelled glucose uptake experiments. In competition experiments, the population dynamics of the mixed culture was determined using specific surface antibodies against C. heintzii and a specific 16S rRNA probe for E. coli. C. heintzii outcompeted E. coli in glucose-limited continuous culture at the low dilution rates of 0.05 and 0.075?h?1. Using the determined pure culture parameter values for Ks and ?max, it was only possible to simulate the population dynamics during competition with an extended form of the Monod model, which includes a finite substrate concentration at zero growth rate (smin). The values estimated for smin were dependent on growth rate; at D=0.05?h?1, it was 12.6 and 0??g?l?1 for E. coli and C. heintzii, respectively. To fit the data at D=0.075?h?1, smin for E. coli had to be raised to 34.9??g?l?1 whereas smin for C. heintzii remained zero. The results of the mathematical simulation suggest that it is not so much the higher Ks value, which is responsible for the unsuccessful competition of E. coli at low residual glucose concentration, but rather the existence of a significant smin.

Fuchslin, Hans Peter; Schneider, Christian; Egli, Thomas

2012-01-01

135

Inhibitory effect of pollen and propolis extracts.  

PubMed

Bee pollen and propolis were collected from Apis mellifera colonies in five regions of Turkey. The antifungal properties of methanol extracts of pollen and propolis (2% and 5% concentrations) were determined on Alternaria alternata and Fusarium oxysporium f. sp. melonis. The least active concentration towards the tested fungi was 2% concentration of both extracts. The inhibitory effect of all propolis extracts on growth of F. oxysporium and A. alternata were generally higher when compared with pollen extracts. The growth of A. alternata and F. oxysporium were not affected at both concentrations of pollens. However, F. oxysporium against propolis extracts was more sensitive than A. alternata (P < 0.01). None of the pollen extracts tested completely inhibited mycelial growth of fungi used in our experiment. Percent inhibition of both pollen concentrations against A. alternata and F. oxysporium was lower than 50%. However, both concentrations of Alanya and Bey?ehir propolis extracts were 100% effective on mycelial growth of F. oxysporium until the 7th day of incubation (P < 0.01). 2% Alanya and Bey?ehir pollen extracts completely stimulated mycelial growth of F. oxysporium on the 7th day of incubation. Both concentrations of propolis extract showed more than 50% inhibition against E. oxysporium. It is suggested that high concentrations ofpropolis extract could be used as an antifungal agent against tested fungi. PMID:15285109

Ozcan, Musa; Unver, Ahmet; Ceylan, Durmu? Ali; Yeti?ir, Ramazan

2004-06-01

136

2013 Arctic Sea Ice Minimum  

NASA Video Gallery

After an unusually cold summer in the northernmost latitudes, Arctic sea ice appears to have reached its annual minimum summer extent for 2013 on Sept. 13, the NASA-supported National Snow and Ice ...

137

Minimum energy mobile wireless networks  

Microsoft Academic Search

We describe a distributed position-based network protocol optimized for minimum energy consumption in mobile wireless networks that support peer-to-peer communications. Given any number of randomly deployed nodes over an area, we show that a simple local optimization scheme executed at each node guarantees strong connectivity of the entire network and attains the global minimum energy solution for the stationary case.

Volkan Rodoplu; Teresa H. Meng

1998-01-01

138

Antioxidant and cyclooxygenase inhibitory phenolic compounds from Ocimum sanctum Linn.  

PubMed

Anti-oxidant bioassay-directed extraction of the fresh leaves and stems of Ocimum sanctum and purification of the extract yielded the following compounds; cirsilineol [1], cirsimaritin [2], isothymusin [3], isothymonin [4], apigenin [5], rosmarinic acid [6], and appreciable quantities of eugenol. The structures of compounds 1-6 were established using spectroscopic methods. Compounds 1 and 5 were isolated previously from O. sanctum whereas compounds 2 and 3 are here identified for the first time from O. sanctum. Eugenol, a major component of the volatile oil, and compounds 1, 3, 4, and 6 demonstrated good antioxidant activity at 10-microM concentrations. Anti-inflammatory activity or cyclooxygenase inhibitory activity of these compounds were observed. Eugenol demonstrated 97% cyclooxygenase-1 inhibitory activity when assayed at 1000-microM concentrations. Compounds 1, 2, and 4-6 displayed 37, 50, 37, 65, and 58% cyclooxygenase-1 inhibitory activity, respectively, when assayed at 1000-microM concentrations. Eugenol and compounds 1, 2, 5, and 6 demonstrated cyclooxygenase-2 inhibitory activity at slightly higher levels when assayed at 1000-microM concentrations. The activities of compounds 1-6 were comparable to ibuprofen, naproxen, and aspirin at 10-, 10-, and 1000-microM concentrations, respectively. These results support traditional uses of O. sanctum and identify the compounds responsible. PMID:10782484

Kelm, M A; Nair, M G; Strasburg, G M; DeWitt, D L

2000-03-01

139

Quinic acid esters from Pluchea indica with collagenase, MMP-2 and MMP-9 inhibitory activities.  

PubMed

Investigation of collagenase inhibitory natural components afforded two quinic acid esters (1 and 2) and quercetin (3) from the leaves of Pluchea indica (Compositae). Of these, compounds 1 and 2 exhibited collagenase inhibitory activity (IC(50)) at a concentration of less than 10 microm, and 1 showed matrix metalloproteinase (MMP)-2 and -9 inhibitory activity (IC(50)) at 2.5 and 6.4 microm, respectively. PMID:17726735

Ohtsuki, Takashi; Yokosawa, Emiko; Koyano, Takashi; Preeprame, Srisomporn; Kowithayakorn, Thaworn; Sakai, Shinobu; Toida, Toshihiko; Ishibashi, Masami

2008-02-01

140

The Thermosphere at Solar Minimum  

NASA Astrophysics Data System (ADS)

The sustained decrease in solar extreme ultraviolet radiation during the current minimum is greater than any in recent history. This gives us the opportunity to study neutral density conditions that are outside the domain of the available empirical models of the thermosphere. While there are currently no experiments measuring in-situ composition of the thermosphere, the accelerometers aboard the CHAMP and GRACE satellites provide a monitor of total atmospheric density, spanning most of solar cycle 23 through the current minimum (2001-2008). Using these data, complemented by ground-based measurements of satellite drag (1996-2008), it appears that agreement between data and empirical models is strongly dependent on satellite altitude during solar minimum, implying an error in our empirical knowledge of the atmospheric scale height. Knowledge of species-dependent behavior with respect to local-time and latitude gives us a crude method of separating the observed scale heights into the competing effects of composition and temperature changes.

Sutton, E. K.; Marcos, F. A.; Lin, C. S.

2009-12-01

141

ACSB: A minimum performance assessment  

NASA Technical Reports Server (NTRS)

Amplitude companded sideband (ACSB) is a new modulation technique which uses a much smaller channel width than does conventional frequency modulation (FM). Among the requirements of a mobile communications system is adequate speech intelligibility. This paper explores this aspect of minimum required performance. First, the basic principles of ACSB are described, with emphasis on those features that affect speech quality. Second, the appropriate performance measures for ACSB are reviewed. Third, a subjective voice quality scoring method is used to determine the values of the performance measures that equate to the minimum level of intelligibility. It is assumed that the intelligibility of an FM system operating at 12 dB SINAD represents that minimum. It was determined that ACSB operating at 12 dB SINAD with an audio-to-pilot ratio of 10 dB provides approximately the same intelligibility as FM operating at 12 dB SINAD.

Jones, Lloyd Thomas; Kissick, William A.

1988-01-01

142

Inhibitory Effect of Glycerin on Vibrio parahaemolyticus and 'Salmonella'.  

National Technical Information Service (NTIS)

In a study of the effect of glycerin in transport media on Vibrio papahaemolyticus and Salmonella, it was found that a concentration of 30% glycerin was highly inhibitory for V. parahaemolyticus and to a lesser degree for Salmonella. The incorporation of ...

C. K. Park D. Chun R. Tak S. Y. Seol

1972-01-01

143

Inhibitory Control in Childhood Stuttering  

ERIC Educational Resources Information Center

Purpose: The purpose of this study was to investigate whether previously reported parental questionnaire-based differences in inhibitory control (IC; Eggers, De Nil, & Van den Bergh, 2010) would be supported by direct measurement of IC using a computer task. Method: Participants were 30 children who stutter (CWS; mean age = 7;05 years) and 30…

Eggers, Kurt; De Nil, Luc F.; Van den Bergh, Bea R. H.

2013-01-01

144

Targeting inhibitory neurotransmission in tinnitus  

PubMed Central

Tinnitus perception depends on the presence of its neural correlates within the auditory neuraxis and associated structures. Targeting specific circuits and receptors within the central nervous system in an effort to relieve the perception of tinnitus and its impact on one’s emotional and mental state has become a focus of tinnitus research. One approach is to upregulate endogenous inhibitory neurotransmitter levels (e.g. glycine and GABA) and selectively target inhibitory receptors in key circuits to normalize tinnitus pathophysiology. Thus, the basic functional and molecular properties of two major ligand-gated inhibitory receptor systems, the GABAA receptor (GABAAR) and glycine receptor (GlyR) are described. Also reviewed is the rationale for targeting inhibition which stems from reported tinnitus-related homeostatic plasticity of inhibitory neurotransmitter systems and associated enhanced neuronal excitability throughout most central auditory structures. However, the putative role of the medial geniculate body (MGB) in tinnitus has not been previously addressed, specifically in terms of its inhibitory afferents from inferior colliculus and thalamic reticular nucleus and its GABAAR functional heterogeneity. This heterogeneous population of GABAARs, which may be altered in tinnitus pathology, and its key anatomical position in the auditory CNS make the MGB a compelling structure for tinnitus research. Finally, some selective compounds, which enhance tonic inhibition, have successfully ameliorated tinnitus in animal studies, suggesting that the MGB and, to a lesser degree, the auditory cortex may be their primary locus of action. These pharmacological interventions are examined, in terms of their mechanism of action and why these agents, may be effective in tinnitus treatment.

Richardson, Ben D.; Brozoski, Thomas J.; Ling, Lynne L.; Caspary, Donald M.

2012-01-01

145

Finding minimum area simple pentagons  

Microsoft Academic Search

Given a set P of n points in the plane, we want to find a simple, not necessarily convex, pentagon Q with vertices in P of minimum area. We present an algorithm for solving this problem in time O(nT(n)) and space O(n), where T(n) is the number of empty triangles in the set.

Jean-françois Hęche; Thomas M. Liebling

1997-01-01

146

Inventory Management for Minimum Cost  

Microsoft Academic Search

One of the most popular types of inveatoiy management is the (Q, r) system, in which a quantity Q of an item is reordered whenever the inventory position reaches the reorder point r. A number of packaged computer programs are available for this system. However, these programs seldom give the minimum-cost values of Q and r, since they usually employ

David P. Herron

1967-01-01

147

Antifungal susceptibility and growth inhibitory response of oral Candida species to Brucea javanica Linn. extract  

PubMed Central

Background Candida species have been associated with the emergence of resistant strains towards selected antifungal agents. Plant products have been used traditionally as alternative medicine to ease candidal infections. The present study was undertaken to investigate the antifungal susceptibility patterns and growth inhibiting effect of Brucea javanica seeds extract against Candida species. Methods A total of seven Candida strains that includes Candida albicans ATCC14053, Candida dubliniensis ATCCMYA-2975, Candida glabrata ATCC90030, Candida krusei ATCC14243, Candida lusitaniae ATCC64125, Candida parapsilosis ATCC22019 and Candida tropicalis ATCC13803 were used in this study. The antifungal activity, minimum inhibitory concentration and minimum fungicidal concentration of B. javanica extract were evaluated. Each strain was cultured in Yeast Peptone Dextrose broth under four different growth environments; (i) in the absence and presence of B. javanica extract at respective concentrations of (ii) 1 mg/ml (iii) 3 mg/ml and (iv) 6 mg/ml. The growth inhibitory responses of the candidal cells were determined based on changes in the specific-growth rates (?) and doubling time (g). The values in the presence of extract were computed as percentage in the optical density relative to that of the total cells suspension in the absence of extract. Results B. javanica seeds extract exhibited antifungal properties. C. tropicalis showed the highest growth rate; 0.319?±?0.002 h-1, while others were in the range of 0.141?±?0.001 to 0.265?±?0.005 h-1. In the presence of extract, the lag and log phases were extended and deviated the ?- and g-values. B. javanica extract had significantly reduced the ?-values of C. dubliniensis, C. krusei and C. parapsilosis at more than 80% (??

2013-01-01

148

Inhibitory effects of respiration inhibitors on aflatoxin production.  

PubMed

Aflatoxin production inhibitors, which do not inhibit the growth of aflatoxigenic fungi, may be used to control aflatoxin without incurring a rapid spread of resistant strains. A respiration inhibitor that inhibits aflatoxin production was identified during a screening process for natural, aflatoxin-production inhibitors. This prompted us to evaluate respiration inhibitors as potential aflatoxin control agents. The inhibitory activities of four natural inhibitors, seven synthetic miticides, and nine synthetic fungicides were evaluated on aflatoxin production in Aspergillus parasiticus. All of the natural inhibitors (rotenone, siccanin, aptenin A5, and antimycin A) inhibited fungal aflatoxin production with IC50 values around 10 µM. Among the synthetic miticides, pyridaben, fluacrypyrim, and tolfenpyrad exhibited strong inhibitory activities with IC50 values less than 0.2 µM, whereas cyflumetofen did not show significant inhibitory activity. Of the synthetic fungicides, boscalid, pyribencarb, azoxystrobin, pyraclostrobin, and kresoxim-methyl demonstrated strong inhibitory activities, with IC50 values less than 0.5 µM. Fungal growth was not significantly affected by any of the inhibitors tested at concentrations used. There was no correlation observed between the targets of respiration inhibitors (complexes I, II, and III) and their IC50 values for aflatoxin-production inhibitory activity. This study suggests that respiration inhibitors, including commonly used pesticides, are useful for aflatoxin control. PMID:24674936

Sakuda, Shohei; Prabowo, Diyan Febri; Takagi, Keiko; Shiomi, Kazuro; Mori, Mihoko; ?mura, Satoshi; Nagasawa, Hiromichi

2014-04-01

149

Inhibitory Effects of Respiration Inhibitors on Aflatoxin Production  

PubMed Central

Aflatoxin production inhibitors, which do not inhibit the growth of aflatoxigenic fungi, may be used to control aflatoxin without incurring a rapid spread of resistant strains. A respiration inhibitor that inhibits aflatoxin production was identified during a screening process for natural, aflatoxin-production inhibitors. This prompted us to evaluate respiration inhibitors as potential aflatoxin control agents. The inhibitory activities of four natural inhibitors, seven synthetic miticides, and nine synthetic fungicides were evaluated on aflatoxin production in Aspergillus parasiticus. All of the natural inhibitors (rotenone, siccanin, aptenin A5, and antimycin A) inhibited fungal aflatoxin production with IC50 values around 10 µM. Among the synthetic miticides, pyridaben, fluacrypyrim, and tolfenpyrad exhibited strong inhibitory activities with IC50 values less than 0.2 µM, whereas cyflumetofen did not show significant inhibitory activity. Of the synthetic fungicides, boscalid, pyribencarb, azoxystrobin, pyraclostrobin, and kresoxim-methyl demonstrated strong inhibitory activities, with IC50 values less than 0.5 µM. Fungal growth was not significantly affected by any of the inhibitors tested at concentrations used. There was no correlation observed between the targets of respiration inhibitors (complexes I, II, and III) and their IC50 values for aflatoxin-production inhibitory activity. This study suggests that respiration inhibitors, including commonly used pesticides, are useful for aflatoxin control.

Sakuda, Shohei; Prabowo, Diyan Febri; Takagi, Keiko; Shiomi, Kazuro; Mori, Mihoko; Omura, Satoshi; Nagasawa, Hiromichi

2014-01-01

150

Pharmacokinetics of orbifloxacin and its concentration in body fluids and in endometrial tissues of mares.  

PubMed Central

Pharmacokinetics and distribution of orbifloxacin into body fluids and endometrium was studied in 6 mares after intragastric (IG) administration at a single dose rate of 7.5 mg/kg body weight. Orbifloxacin concentrations were serially measured in serum, synovial fluid, peritoneal fluid, urine, cerebrospinal fluid, and endometrial tissues over 24 hours. Minimum inhibitory concentrations of orbifloxacin were determined for 120 equine pathogens over an 11-month period. The mean peak serum concentration (Cmax) was 2.41+/-0.30 microg/mL at 1.5 hours after administration and decreased to 0.17+/-0.01 microg/mL (Cmin) at 24 hours. The mean elimination half-life (t1/2) was 9.06+/-1.33 hours and area under the serum concentration vs time curve (AUC) was 20.54+/-1.70 mg h/L. Highest mean peritoneal fluid concentration was 2.15+/-0.49 microg/mL at 2 hours. Highest mean synovial fluid concentration was 1.17+/-0.28 microg/mL at 4 hours. Highest mean urine concentration was 536.67+/-244.79 microg/mL at 2 hours. Highest mean endometrial concentration was 0.72+/-0.23 microg/g at 1.5 hours. Mean CSF concentration was 0.46+/-0.55 microg/mL at 3 hours. The minimum inhibitory concentration of orbifloxacin required to inhibit 90% of isolates (MIC90) ranged from < or = 0.12 to > 8.0 microg/mL, with gram-negative organisms being more sensitive than gram-positive organisms. Orbifloxacin was uniformly absorbed in the 6 mares and was well distributed into body fluids and endometrial tissue. At a dosage of 7.5 mg/kg once a day, many gram-negative pathogens, such as Actinobacillus equuli, Escherichia coli, Pasteurella spp., and Salmonella spp. would be expected to be susceptible to orbifloxacin.

Haines, G R; Brown, M P; Gronwall, R R; Merritt, K A; Baltzley, L K

2001-01-01

151

The TCP Minimum RTO Revisited  

Microsoft Academic Search

We re-examine the two reasons for the conservative 1-second Minimum TCP-RTO to protect against spurious timeouts: i) the OS clock granularity and ii) the Delayed ACKs. We find that reason (i) is canceled in modern OSs; we carefully design a mechanism to deal with reason (ii). Simulation results show that in next generation's high-speed, wireless- access networks, TCP-RTO should not

Ioannis Psaras; Vassilis Tsaoussidis

2007-01-01

152

Safe Minimum Internal Temperature Chart  

MedlinePLUS

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153

Law of the Minimum paradoxes.  

PubMed

The "Law of the Minimum" states that growth is controlled by the scarcest resource (limiting factor). This concept was originally applied to plant or crop growth (Justus von Liebig, 1840, Salisbury, Plant physiology, 4th edn., Wadsworth, Belmont, 1992) and quantitatively supported by many experiments. Some generalizations based on more complicated "dose-response" curves were proposed. Violations of this law in natural and experimental ecosystems were also reported. We study models of adaptation in ensembles of similar organisms under load of environmental factors and prove that violation of Liebig's law follows from adaptation effects. If the fitness of an organism in a fixed environment satisfies the Law of the Minimum then adaptation equalizes the pressure of essential factors and, therefore, acts against the Liebig's law. This is the the Law of the Minimum paradox: if for a randomly chosen pair "organism-environment" the Law of the Minimum typically holds, then in a well-adapted system, we have to expect violations of this law.For the opposite interaction of factors (a synergistic system of factors which amplify each other), adaptation leads from factor equivalence to limitations by a smaller number of factors.For analysis of adaptation, we develop a system of models based on Selye's idea of the universal adaptation resource (adaptation energy). These models predict that under the load of an environmental factor a population separates into two groups (phases): a less correlated, well adapted group and a highly correlated group with a larger variance of attributes, which experiences problems with adaptation. Some empirical data are presented and evidences of interdisciplinary applications to econometrics are discussed. PMID:21088995

Gorban, Alexander N; Pokidysheva, Lyudmila I; Smirnova, Elena V; Tyukina, Tatiana A

2011-09-01

154

A new imminent grand minimum?  

NASA Astrophysics Data System (ADS)

The planetary hypothesis of solar cycle is an old idea by which the planetary gravity acting on the Sun might have a non-negligible effect on the solar magnetic cycle. The advance of this hypothesis is based on phenomenological correlations between dynamical parameters of the Sun's movement around the barycenter of the Solar System and sunspots time series. In addition, several authors have proposed, using different methodologies that the first Grand Minima (GM) event of the new millennium is coming or has already begun. We present new fully three dimensional N-body simulations of the solar inertial motion (SIM) around the barycentre of the solar system in order to perform a phenomenological comparison between relevant SIM dynamical parameters and the occurrences of the last GM events (i.e., Maunder and Dalton). Our fundamental result is that the Sun acceleration decomposed in a co-orbital reference system shows a very particular behaviour that is common to Maunder minimum, Dalton minimum and the maximum of cycle 22 (around 1990), before the present prolonged minimum. We discuss our results in terms of a dynamical characterization of GM with relation to Sun dynamics and possible implications for a new GM event.

Cionco, Rodolfo G.; Compagnucci, Rosa H.

2012-07-01

155

The inhibitory potential of Thai mango seed kernel extract against methicillin-resistant Staphylococcus aureus.  

PubMed

Plant extracts are a valuable source of novel antibacterial compounds to combat pathogenic isolates of methicillin-resistant Staphylococcus aureus (MRSA), a global nosocomial infection. In this study, the alcoholic extract from Thai mango (Mangifera indica L. cv. 'Fahlun') seed kernel extract (MSKE) and its phenolic principles (gallic acid, methyl gallate and pentagalloylglucopyranose) demonstrated potent in vitro antibacterial activity against Staphylococcus aureus and 19 clinical MRSA isolates in studies of disc diffusion, broth microdilution and time-kill assays. Electron microscopy studies using scanning electron microscopy and transmission electron microscopy revealed impaired cell division and ultra-structural changes in bacterial cell morphology, including the thickening of cell walls, of microorganisms treated with MSKE; these damaging effects were increased with increasing concentrations of MSKE. MSKE and its phenolic principles enhanced and intensified the antibacterial activity of penicillin G against 19 clinical MRSA isolates by lowering the minimum inhibitory concentration by at least 5-fold. The major phenolic principle, pentagalloylglucopyranose, was demonstrated to be the major contributor to the antibacterial activity of MSKE. These results suggest that MSKE may potentially be useful as an alternative therapeutic agent or an adjunctive therapy along with penicillin G in the treatment of MRSA infections. PMID:21788933

Jiamboonsri, Pimsumon; Pithayanukul, Pimolpan; Bavovada, Rapepol; Chomnawang, Mullika T

2011-01-01

156

Minimum income protection in the Netherlands  

Microsoft Academic Search

This article offers an overview of the Dutch legal system of minimum income protection through collective bargaining, social security, and statutory minimum wages. In addition to collective agreements, the Dutch statutory minimum wage offers income protection to a small number of workers. Its effectiveness is difficult to asses, in particular with regard to migrant workers. The Minimum Wage Act plays

Peijpe van T

2009-01-01

157

Inhibitory effects of ginseng seed on melanin biosynthesis  

PubMed Central

Background: Ginseng root has been traditionally used for the treatment of many diseases in Korea. However, so far ginseng seed has been mostly unused and discarded. As part of our ongoing research on the ginseng seeds, the inhibitory effect of ginseng seeds on melanin production was verified to assess their potential as a skin depigmenting substance. Materials and Methods: The present study measured the inhibitory effect of ginseng seeds on melanin production through the tyrosinase inhibitory effect and analyzed their effects on melanin production in melan-a-cells. Results: Ethanol extract of ginseng seed was applied to melan-a-cells at a concentration of 100 ppm and melanin production was reduced by 35.1% without cytotoxicity. In addition, the ethanol extract of ginseng seed was shown to reduce tyrosinase activity. Conclusion: Because the results showed excellent melanin inhibitory activity compared with that obtained by arbutin, ethanol extracts of ginseng leaf and ginseng root at the same concentration, it can be concluded that ginseng seeds show great potential as a skin depigmenting substance.

Lee, Yeonmi; Kim, Kyoung-Tack; Kim, Sung Soo; Hur, Jinyoung; Ha, Sang Keun; Cho, Chang-Won; Choi, Sang Yoon

2014-01-01

158

Ceramic veneers with minimum preparation.  

PubMed

The aim of this article is to describe the possibility of improving dental esthetics with low-thickness glass ceramics without major tooth preparation for patients with small to moderate anterior dental wear and little discoloration. For this purpose, a carefully defined treatment planning and a good communication between the clinician and the dental technician helped to maximize enamel preservation, and offered a good treatment option. Moreover, besides restoring esthetics, the restorative treatment also improved the function of the anterior guidance. It can be concluded that the conservative use of minimum thickness ceramic laminate veneers may provide satisfactory esthetic outcomes while preserving the dental structure. PMID:24932126

da Cunha, Leonardo Fernandes; Reis, Rachelle; Santana, Lino; Romanini, Jose Carlos; Carvalho, Ricardo Marins; Furuse, Adilson Yoshio

2013-10-01

159

Ceramic veneers with minimum preparation  

PubMed Central

The aim of this article is to describe the possibility of improving dental esthetics with low-thickness glass ceramics without major tooth preparation for patients with small to moderate anterior dental wear and little discoloration. For this purpose, a carefully defined treatment planning and a good communication between the clinician and the dental technician helped to maximize enamel preservation, and offered a good treatment option. Moreover, besides restoring esthetics, the restorative treatment also improved the function of the anterior guidance. It can be concluded that the conservative use of minimum thickness ceramic laminate veneers may provide satisfactory esthetic outcomes while preserving the dental structure.

da Cunha, Leonardo Fernandes; Reis, Rachelle; Santana, Lino; Romanini, Jose Carlos; Carvalho, Ricardo Marins; Furuse, Adilson Yoshio

2013-01-01

160

A model for nitrate distributions in oceanic oxygen minimum zones  

NASA Astrophysics Data System (ADS)

The vertical distributions of nitrate and nitrate deficit (nitrate consumed during denitrification) in oxygen minimum zones are modeled using a recycling mechanism incorporating bacterially mediated reaction and diffusion. At the core of the oxygen minimum zone bacteria reduce nitrate to nitrite and part of the nitrte to molecular nitrogen (denitrification). The remaining nitrite diffuses out of the layer, is oxidized to nitrate by nitrifying bacteria, and diffuses back into the layer to complete the cycle. The peak nitrite and nitrate deficit concentrations and the amount of recycling depend on two parameters: ?, the ratio of the sum of the nitrate and nitrate reduction rates to the diffusion coefficient, and ?, the ratio of the nitrate reduction rate to the sum of the nitrate and nitrite reduction rates. We estimate from peak concentrations that for oxygen minimum zones in the Arabian Sea, the eastern tropical North Pacific, and the coastal waters of Peru that the nitrogen production rate is between 39 and 60% of the nitrate reduction rate, with the difference in rates equaling the recycling rate between the denitrifying and nitrifying layers. A dependency of ? and ? on organic substrates available to denitrifying bacteria is suggested from independent chemostat studies and the primary productivity overlying the oxygen minimum zones. The peak concentrations of nitrite and nitrate deficit are near the mid-depth of the denitrifying layer, and from this characteristic we estimate the thickness of the denitrifying layers to be between 30 and 70% of the thickness of the oxygen minimum zones.

Anderson, James Jay; Okubo, Akira; Robbins, Alan S.; Richards, Francis A.

1982-09-01

161

Inhibitory Spectra and Modes of Antimicrobial Action of Gallotannins from Mango Kernels (Mangifera indica L.) ? †  

PubMed Central

This study investigated the antimicrobial activities and modes of action of penta-, hexa-, hepta-, octa-, nona-, and deca-O-galloylglucose (gallotannins) isolated from mango kernels. The MICs and minimum bactericidal concentrations (MBCs) against food-borne bacteria and fungi were determined using a critical dilution assay. Gram-positive bacteria were generally more susceptible to gallotannins than were Gram-negative bacteria. The MICs of gallotannins against Bacillus subtilis, Bacillus cereus, Clostridium botulinum, Campylobacter jejuni, Listeria monocytogenes, and Staphylococcus aureus were 0.2 g liter?1 or less; enterotoxigenic Escherichia coli and Salmonella enterica were inhibited by 0.5 to 1 g liter?1, and lactic acid bacteria were resistant. The use of lipopolysaccharide mutants of S. enterica indicated that the outer membrane confers resistance toward gallotannins. Supplementation of LB medium with iron eliminated the inhibitory activity of gallotannins against Staphylococcus aureus, and siderophore-deficient mutants of S. enterica were less resistant toward gallotannins than was the wild-type strain. Hepta-O-galloylglucose sensitized Lactobacillus plantarum TMW1.460 to hop extract, indicating inactivation of hop resistance mechanisms, e.g., the multidrug resistance (MDR) transporter HorA. Carbohydrate metabolism of Lactococcus lactis MG1363, a conditionally respiring organism, was influenced by hepta-O-galloylglucose when grown under aerobic conditions and in the presence of heme but not under anaerobic conditions, indicating that gallotannins influence the respiratory chain. In conclusion, the inhibitory activities of gallotannins are attributable to their strong affinity for iron and likely additionally relate to the inactivation of membrane-bound proteins.

Engels, Christina; Schieber, Andreas; Ganzle, Michael G.

2011-01-01

162

Monetary rewards modulate inhibitory control  

PubMed Central

The ability to override a dominant response, often referred to as behavioral inhibition, is considered a key element of executive cognition. Poor behavioral inhibition is a defining characteristic of several neurological and psychiatric populations. Recently, there has been increasing interest in the motivational dimension of behavioral inhibition, with some experiments incorporating emotional contingencies in classical inhibitory paradigms such as the Go/NoGo and Stop Signal Tasks (SSTs). Several studies have reported a positive modulatory effect of reward on performance in pathological conditions such as substance abuse, pathological gambling, and Attention Deficit Hyperactive Disorder (ADHD). However, experiments that directly investigate the modulatory effects of reward magnitudes on the performance of inhibitory tasks are scarce and little is known about the finer grained relationship between motivation and inhibitory control. Here we probed the effect of reward magnitude and context on behavioral inhibition with three modified versions of the widely used SST. The pilot study compared inhibition performance during six blocks alternating neutral feedback, low, medium, and high monetary rewards. Study One compared increasing vs. decreasing rewards, with low, high rewards, and neutral feedback; whilst Study Two compared low and high reward magnitudes alone also in an increasing and decreasing reward design. The reward magnitude effect was not demonstrated in the pilot study, probably due to a learning effect induced by practice in this lengthy task. The reward effect per se was weak but the context (order of reward) was clearly suggested in Study One, and was particularly strongly confirmed in study two. In addition, these findings revealed a “kick start effect” over global performance measures. Specifically, there was a long lasting improvement in performance throughout the task when participants received the highest reward magnitudes at the beginning of the protocol. These results demonstrate a dynamical behavioral inhibition capacity in humans, as illustrated by the reward magnitude modulation and initial reward history effects.

Herrera, Paula M.; Speranza, Mario; Hampshire, Adam; Bekinschtein, Tristan A.

2014-01-01

163

Monetary rewards modulate inhibitory control.  

PubMed

The ability to override a dominant response, often referred to as behavioral inhibition, is considered a key element of executive cognition. Poor behavioral inhibition is a defining characteristic of several neurological and psychiatric populations. Recently, there has been increasing interest in the motivational dimension of behavioral inhibition, with some experiments incorporating emotional contingencies in classical inhibitory paradigms such as the Go/NoGo and Stop Signal Tasks (SSTs). Several studies have reported a positive modulatory effect of reward on performance in pathological conditions such as substance abuse, pathological gambling, and Attention Deficit Hyperactive Disorder (ADHD). However, experiments that directly investigate the modulatory effects of reward magnitudes on the performance of inhibitory tasks are scarce and little is known about the finer grained relationship between motivation and inhibitory control. Here we probed the effect of reward magnitude and context on behavioral inhibition with three modified versions of the widely used SST. The pilot study compared inhibition performance during six blocks alternating neutral feedback, low, medium, and high monetary rewards. Study One compared increasing vs. decreasing rewards, with low, high rewards, and neutral feedback; whilst Study Two compared low and high reward magnitudes alone also in an increasing and decreasing reward design. The reward magnitude effect was not demonstrated in the pilot study, probably due to a learning effect induced by practice in this lengthy task. The reward effect per se was weak but the context (order of reward) was clearly suggested in Study One, and was particularly strongly confirmed in study two. In addition, these findings revealed a "kick start effect" over global performance measures. Specifically, there was a long lasting improvement in performance throughout the task when participants received the highest reward magnitudes at the beginning of the protocol. These results demonstrate a dynamical behavioral inhibition capacity in humans, as illustrated by the reward magnitude modulation and initial reward history effects. PMID:24860469

Herrera, Paula M; Speranza, Mario; Hampshire, Adam; Bekinschtein, Tristán A

2014-01-01

164

STATISTICAL PROCEDURES FOR DETERMINATION AND VERIFICATION OF MINIMUM REPORTING LEVELS FOR DRINKING WATER METHODS  

EPA Science Inventory

The United States Environmental Protection Agency's (EPA) Office of Ground Water and Drinking Water (OGWDW) has developed a single-laboratory quantitation procedure: the lowest concentration minimum reporting level (LCMRL). The LCMRL is the lowest true concentration for which fu...

165

Developmental plasticity of auditory cortical inhibitory synapses  

PubMed Central

Functional inhibitory synapses form in auditory cortex well before the onset of normal hearing. However, their properties change dramatically during normal development, and many of these maturational events are delayed by hearing loss. Here, we review recent findings on the developmental plasticity of inhibitory synapse strength, kinetics, and GABAA receptor localization in auditory cortex. Although hearing loss generally leads to a reduction of inhibitory strength, this depends on the type of presynaptic interneuron. Furthermore, plasticity of inhibitory synapses also depends on the postsynaptic target. Hearing loss leads reduced GABAA receptor localization to the membrane of excitatory, but not inhibitory neurons. A reduction in normal activity in development can also affect the use-dependent plasticity of inhibitory synapses. Even moderate hearing loss can disrupt inhibitory short- and long-term synaptic plasticity. Thus, the cortex did not compensate for the loss of inhibition in the brainstem, but rather exacerbated the response to hearing loss by further reducing inhibitory drive. Together, these results demonstrate that inhibitory synapses are exceptionally dynamic during development, and deafness-induced perturbation of inhibitory properties may have a profound impact on auditory processing.

Sanes, Dan H.; Kotak, Vibhakar C.

2011-01-01

166

Inhibitory effects of Thyme oils on growth and aflatoxin production by Aspergillus parasiticus  

Microsoft Academic Search

Inhibition of Aspergillus parasiticus growth and its aflatoxin production exposed to the essential oils extracted from two varieties of Thyme i.e. Thymus eriocalyx and Thymus x-porlock were studied. The disc diffusion method was used to evaluate the zone of fungal growth inhibition at various concentrations of the oils. Minimal inhibitory concentration (MIC) and minimal fungicidal concentration (MFC) of the oils

Iraj Rasooli; Mehdi Razzaghi Abyaneh

2004-01-01

167

Inhibitory and Bactericidal Potential of Crude Acetone Extracts of Combretum molle (Combretaceae) on Drug-resistant Strains of Helicobacter pylori  

PubMed Central

Infection with Helicobacter pylori is strongly associated with a number of gastroduodenal pathologies. Antimicrobial resistance to commonly-used drugs has generated a considerable interest in the search for novel therapeutic compounds from medicinal plants. As an ongoing effort of this search, the susceptibility of 32 clinical strains of H. pylori and a reference strain—NCTC 11638—was evaluated against five solvent extracts of Combretum molle, a plant widely used for the treatment of gastric ulcers and other stomach-related morbidities in South Africa. The extracts were screened for activity by the agar-well diffusion method, and the most active one of them was tested against the same strains by micro-broth dilution and time kill assays. Metronidazole and amoxicillin were included in these experiments as positive control antibiotics. The solvent extracts all demonstrated anti-H. pylori activity with zone diameters of inhibition between 0 and 38 mm. The most potent anti-H. pylori activity was demonstrated by the acetone extract, to which 87.5% of the clinical strains were susceptible. The minimum inhibitory concentration (MIC90) values for this extract ranged from 1.25 to 5.0 mg/mL while those for amoxicillin and metronidazole ranged from 0.001 to 0.94 mg/mL and from 0.004 to 5.0 mg/mL respectively. The acetone extract was highly bactericidal at a concentration of 2.5 and 5.0 mg/mL, with complete elimination of the test organisms in 24 hours. Its inhibitory activity was better than that of metronidazole (p<0.05) as opposed to amoxicillin (p<0.05). The results demonstrate that C. molle may contain therapeutically-useful compounds against H. pylori, which are mostly concentrated in the acetone extract.

Njume, Collise; Afolayan, Anthony J.; Samie, Amidou

2011-01-01

168

Pruning a minimum spanning tree  

NASA Astrophysics Data System (ADS)

This work employs various techniques in order to filter random noise from the information provided by minimum spanning trees obtained from the correlation matrices of international stock market indices prior to and during times of crisis. The first technique establishes a threshold above which connections are considered affected by noise, based on the study of random networks with the same probability density distribution of the original data. The second technique is to judge the strength of a connection by its survival rate, which is the amount of time a connection between two stock market indices endures. The idea is that true connections will survive for longer periods of time, and that random connections will not. That information is then combined with the information obtained from the first technique in order to create a smaller network, in which most of the connections are either strong or enduring in time.

Sandoval, Leonidas

2012-04-01

169

Inhibitory effects of Thai plants ?-glycosides on Trichomonas vaginalis  

Microsoft Academic Search

Trichomoniasis is now an important health problem in developing countries. Although metronidazole has so far been widely used\\u000a to treat this disease, the prevalence of metronidazole-resistant protozoa and unpleasant adverse effects have been found.\\u000a In this study, natural products purified from Thai plants were, therefore, investigated for their effectiveness against Trichomonas vaginalis. The minimal inhibitory concentrations for all ?-glycosides against

Dumrongkiet Arthan; Somphong Sithiprom; Kanthinich Thima; Chutima Limmatvatirat; Porntip Chavalitshewinkoon-Petmitr; Jisnuson Svasti

2008-01-01

170

The inhibitory effects of amrinone on isolated rat uterus  

Microsoft Academic Search

Amrinone, a new cardiotonic drug, has received attention as a better therapeutic agent than the cardiac glycosides in the\\u000a treatment of congestive heart failure. In this study, the effects of amrinone on isolated rat uterus and its probable mechanism\\u000a of action were investigated. At two different concentrations (0.1 and 0.5 mM) the inhibitory effects of amrinone on the spontaneous contractions

Y. Kesim; S. Celik; N. Banoglu

1994-01-01

171

Cortical Plasticity Induced by Inhibitory Neuron Transplantation  

PubMed Central

Critical periods are times of pronounced brain plasticity. During a critical period in the postnatal development of the visual cortex, the occlusion of one eye triggers a rapid reorganization of neuronal responses, a process known as ocular dominance plasticity. We have shown that the transplantation of inhibitory neurons induces ocular dominance plasticity after the critical period. Transplanted inhibitory neurons receive excitatory synapses, make inhibitory synapses onto host cortical neurons, and promote plasticity when they reach a cellular age equivalent to that of endogenous inhibitory neurons during the normal critical period. These findings suggest that ocular dominance plasticity is regulated by the execution of a maturational program intrinsic to inhibitory neurons. By inducing plasticity, inhibitory neuron transplantation may facilitate brain repair.

Southwell, Derek G.; Froemke, Robert C.; Alvarez-Buylla, Arturo; Stryker, Michael P.; Gandhi, Sunil P.

2011-01-01

172

Dual inhibitory control in crab leg muscles  

Microsoft Academic Search

1.The physiological effects of two inhibitory axons supplying the stretcher muscles of three crabs (Hyas, Gecarcinus andGrapsus) were investigated, with a view to establishing the relative importance of pre- and postsynaptic inhibition.2.InHyas, the specific inhibitory (SI) axon and the common inhibitory (CI) axon both exerted powerful presynaptic inhibition on the terminals of the excitatory axon. The effect of the SI

T. J. Wiens; H. L. Atwood

1975-01-01

173

Xanthine oxidase inhibitory activity of Vietnamese medicinal plants.  

PubMed

Among 288 extracts, prepared from 96 medicinal plants used in Vietnamese traditional medicine to treat gout and related symptoms, 188 demonstrated xanthine oxidase (XO) inhibitory activity at 100 microg/ml, with 46 having greater than 50% inhibition. At 50 microg/ml, 168 of the extracts were active, with 21 possessing more than 50% inhibition. At 25 microg/ml, 146 extracts exhibited inhibitory activity, with 8 showing over 50% inhibition, while 126 extracts presented activity at 10 microg/ml, with 2 having greater than 50% inhibition. The MeOH extracts of Artemisia vulgaris, Caesalpinia sappan (collected at the Seven-Mountain area), Blumea balsamifera (collected in Lam Dong province), Chrysanthemum sinense and MeOH-H(2)O extract of Tetracera scandens (Khanh Hoa province) exhibited strong XO inhibitory activity with IC(50) values less than 20 microg/ml. The most active extract was the MeOH extract of the flower of C. sinense with an IC(50) value of 5.1 microg/ml. Activity-guided fractionation of the MeOH extract led to the isolation of caffeic acid (1), luteolin (2), eriodictyol (3), and 1,5-di-O-caffeoylquinic acid (4). All these compounds showed significant XO inhibitory activity in a concentration-dependent manner, and the activity of 2 was more potent (IC(50) 1.3 microM) than the clinically used drug, allopurinol (IC(50) 2.5 microM). PMID:15340229

Nguyen, Mai Thanh Thi; Awale, Suresh; Tezuka, Yasuhiro; Tran, Quan Le; Watanabe, Hiroshi; Kadota, Shigetoshi

2004-09-01

174

Mining association rules with multiple minimum supports  

Microsoft Academic Search

Association rule mining is an important model in data mining. Its mining algorithms discover all it em associations (or r ules) in the data that satisfy the user-specified minimum support (minsup) and minimum confidence (minconf) constraints. Minsup controls the minimum number of data ca ses that a rule must cover. Minconf controls the predictive strength of the rule. Since only

Bing Liu; Wynne Hsu; Yiming Ma

1999-01-01

175

Minimum-energy mobile wireless networks revisited  

Microsoft Academic Search

We propose a protocol that, given a communication network, computes a subnetwork such that, for every pair (u, υ) of nodes connected in the original network, there is a a minimum-energy path between u and υ in the subnetwork (where a minimum-energy path is one that allows messages to be transmitted with a minimum use of energy). The network computed

Li Li; J. Y. Halpern

2001-01-01

176

Medicinal plant extracts with efflux inhibitory activity against Gram-negative bacteria.  

PubMed

It was hypothesised that extracts from plants that are used as herbal medicinal products contain inhibitors of efflux in Gram-negative bacteria. Extracts from 21 plants were screened by bioassay for synergy with ciprofloxacin against Salmonella enterica serotype Typhimurium, including mutants in which acrB and tolC had been inactivated. The most active extracts, fractions and purified compounds were further examined by minimum inhibitory concentration testing with five antibiotics for activity against Enterobacteriaceae and Pseudomonas aeruginosa. Efflux activity was determined using the fluorescent dye Hoechst 33342. Eighty-four extracts from 21 plants, 12 fractions thereof and 2 purified molecules were analysed. Of these, 12 plant extracts showed synergy with ciprofloxacin, 2 of which had activity suggesting efflux inhibition. The most active extract, from Levisticum officinale, was fractionated and the two fractions displaying the greatest synergy with the five antibiotics were further analysed. From these two fractions, falcarindiol and the fatty acids oleic acid and linoleic acid were isolated. The fractions and compounds possessed antibacterial activity especially for mutants lacking a component of AcrAB-TolC. However, no synergism was seen with the fractions or purified molecules, suggesting that a combination of compounds is required for efflux inhibition. These data indicate that medicinal plant extracts may provide suitable lead compounds for future development and possible clinical utility as inhibitors of efflux for various Gram-negative bacteria. PMID:21194895

Garvey, Mark I; Rahman, M Mukhlesur; Gibbons, Simon; Piddock, Laura J V

2011-02-01

177

Inhibitory effect of cyclic trihydroxamate siderophore, desferrioxamine E, on the biofilm formation of Mycobacterium species.  

PubMed

Formation of biofilm in pathogenic bacteria defends them from antibiotics and the immune system of a host's life. Hence, investigation of the molecular mechanisms of biofilm formation and search for new substances counteracting this formation are becoming an attractive research area. In the course of our search for new inhibitors of biofilm formation in Mycobacterium species, we rediscovered a cyclic trihydroxamate siderophore, desferrioxamine E, from the culture of the marine-derived Actinomycete MS67. Desferrioxamine E inhibited biofilm formation of Mycobacterium smegmatis and M. bovis BACILLE de CALMETTE et GUÉRIN (BCG) with minimum inhibitory concentration (MIC) value of 10 µM, while no anti-microbial activity was observed up to 160 µM. Desferrioxamine E was also able to restore the anti-microbial activity of isoniazid against M. smegmatis by inhibiting biofilm formation. Mechanistic analysis of desferrioxamine E suggested that such inhibition might come from the depletion of iron in the medium, which is essential for biofilm formation in Mycobacterium species. PMID:21628895

Ishida, Shunsuke; Arai, Masayoshi; Niikawa, Hiroki; Kobayashi, Motomasa

2011-01-01

178

Inhibitory effect of essential oils against Trichosporon ovoides causing Piedra Hair Infection  

PubMed Central

Piedra, is an asymptomatic fungal infection of the hair shaft, resulting in the formation of nodules of different hardness on the infected hair. The infection also known as Trichomycosis nodularis is a superficial fungal infection arising from the pathogen being restricted to the stratum corneum with little or no tissue reaction. The nodules are a concretion of hyphae and fruiting bodies of the fungus. Two varieties of Piedra may be seen, Black Piedra and White Piedra. The fungus Trichosporon ovoides is involved in the occurrence of both types of Piedras. The purpose of this study was to examine the effectiveness of selected essential oils for the control of growth of the fungus and to determine whether the antifungal effect was due to the major compounds of the oils. Two screening methods viz. Agar well diffusion assay and Minimum Inhibitory Concentration were adopted for the study. MIC and MFC were determined by tube dilution method. Essential oils from Eucalyptus, Ocimum basilicum, Mentha piperita, Cymbopogon flexuosus, Cymbopogon winterians, Trachyspermum ammi, Zingiber officinalis, Citrus limon, Cinnamomon zeylanicum, Salvia sclarea, Citrus aurantifolia, Melaleuca alternifolia, Citrus aurantium, Citrus bergamia, Pogostemon pathchouli, Cedrus atlantica, Jasminum officinale, Juniperus communis, Abelmoschus moschatus, Cyperus scariosus, Palargonium graveolens, Boswellia carterii, Rosa damascene, Veteveria zizanoides and Commiphora myrrha were evaluated. The essential oils of Cymbopogon winterians, Mentha piperita, Cinnamomum zeylanicum, Melaleuca alternifolia and Eucalyptus globulus were proved to be most effective against the fungus Trichosporon ovoides.

Saxena, Seema; Uniyal, Veena; Bhatt, R.P.

2012-01-01

179

Inhibitory effect of essential oils against Trichosporon ovoides causing Piedra Hair Infection.  

PubMed

Piedra, is an asymptomatic fungal infection of the hair shaft, resulting in the formation of nodules of different hardness on the infected hair. The infection also known as Trichomycosis nodularis is a superficial fungal infection arising from the pathogen being restricted to the stratum corneum with little or no tissue reaction. The nodules are a concretion of hyphae and fruiting bodies of the fungus. Two varieties of Piedra may be seen, Black Piedra and White Piedra. The fungus Trichosporon ovoides is involved in the occurrence of both types of Piedras. The purpose of this study was to examine the effectiveness of selected essential oils for the control of growth of the fungus and to determine whether the antifungal effect was due to the major compounds of the oils. Two screening methods viz. Agar well diffusion assay and Minimum Inhibitory Concentration were adopted for the study. MIC and MFC were determined by tube dilution method. Essential oils from Eucalyptus, Ocimum basilicum, Mentha piperita, Cymbopogon flexuosus, Cymbopogon winterians, Trachyspermum ammi, Zingiber officinalis, Citrus limon, Cinnamomon zeylanicum, Salvia sclarea, Citrus aurantifolia, Melaleuca alternifolia, Citrus aurantium, Citrus bergamia, Pogostemon pathchouli, Cedrus atlantica, Jasminum officinale, Juniperus communis, Abelmoschus moschatus, Cyperus scariosus, Palargonium graveolens, Boswellia carterii, Rosa damascene, Veteveria zizanoides and Commiphora myrrha were evaluated. The essential oils of Cymbopogon winterians, Mentha piperita, Cinnamomum zeylanicum, Melaleuca alternifolia and Eucalyptus globulus were proved to be most effective against the fungus Trichosporon ovoides. PMID:24031963

Saxena, Seema; Uniyal, Veena; Bhatt, R P

2012-10-01

180

Inhibitory effects of essential oils of medicinal plants from growth of plant pathogenic fungi.  

PubMed

Plant cells produce a vast amount of secondary metabolites. Production of some compounds is restricted to a single species. Some compounds are nearly always found only in certain specific plant organs and during a specific developmental period of the plant. Some secondary metabolites of plants serve as defensive compounds against invading microorganisms. Nowadays, it is attempted to substitute the biological and natural agents with chemically synthesized fungicides. In the present research, the antifungal activities of essential oils of seven medicinal plants on mycelial growth of three soilborne plant pathogenic fungi were investigated. The plants consisted of Zataria multiflora, Thymus carmanicus, Mentha pieperata, Satureja hortensis, Lavandual officinolis, Cuminum cyminum and Azadirachta indica. The first five plants are from the family Labiatae. Examined fungi, Fusarium oxysporum f.sp. lycopersici, Fusarium solani and Rhizoctonia solani are the causal agents of tomato root rot. Essential oils of Z. multiflora, T. carmanicus, M. pieperata, S. hortensis and C. cyminum were extracted by hydro-distillation method. Essential oils of L. officinalis and A. indica were extracted by vapor-distillation method. A completely randomized design with five replicates was used to examine the inhibitory impact of each concentration (300, 600 and 900 ppm) of each essential oil. Poisoned food assay using potato dextrose agar (PDA) medium was employed. Results showed that essential oils of A. indica, Z. multiflora, T. carmanicus and S. hortensis in 900 ppm at 12 days post-inoculation, when the control fungi completely covered the plates, prevented about 90% from mycelial growth of each of the fungi. While, the essential oils of M. pieperata, C. cyminum and L. officinalis in the same concentration and time prevented 54.86, 52.77 and 48.84%, respectively, from F. solani growth. These substances did not prevent from F. oxysporum f.sp. lycopersici and R. solani growth. Minimum inhibitory concentration (MIC) of essential oils of T. carmanicus, Z. multiflora and A. indica from R. solani and F. solani growth was 900 and 600 ppm, respectively. In addition, the MIC of essential oils of these plants and essential oil of S. hortensis from F. oxysporum f.sp. lycopersici growth was 900 ppm. The MIC of essential oils of M. pieperata, C. cyminum and L. officinalis from F. solani growth was 900 ppm. PMID:22702190

Panjehkeh, N; Jahani Hossein-Abadi, Z

2011-01-01

181

Arctic sea ice minimum extent  

NASA Astrophysics Data System (ADS)

The extent of Arctic sea ice dropped to 3.41 million square kilometers on 16 September, 760,000 square kilometers below the minimum ice extent in 2007, which had been the low mark since the satellite record began in 1979, the National Snow and Ice Data Center (NSIDC) announced. Overall ice extent is 50% below where it was in the 1970s, NSIDC research scientist Walt Meier said during a 19 September briefing. He added that there is also a decrease in ice thickness. Meier said that sea ice varies from year to year with lots of ups and downs. “We wouldn't expect it to keep going down, straight off the map so to speak,” he said. “Typically after a record low, we've seen it rebound.” Meier added that the general long-term trend is for the Arctic to continue to become generally ice free. He said it is difficult to know how long it will take for that condition to be reached; because of strong variations, Arctic sea ice extent could plateau for some time.

Showstack, Randy

2012-10-01

182

Inhibitory activity of Syzygium aromaticum and Cymbopogon citratus (DC.) Stapf. essential oils against Listeria monocytogenes inoculated in bovine ground meat.  

PubMed

This research evaluated the antimicrobial effect of the clove (Syzygium aromaticum) and lemongrass (Cymbopogon citratus (DC.) Stapf.) essential oils (EOs) against Listeria monocytogenes ATCC 19117 growth added to bovine ground meat stored under refrigeration (5 ± 2 °C) for three days. The EOs, extracted by hydrodistillation and analyzed by gas chromatography-mass spectrometry (GC-MS), were tested in vitro using an agar well diffusion methodology for determination of Minimum Inhibitory Concentration (MIC). The MIC concentrations for both essential oils on culture tested of L. monocytogenes were 1.56%. The EOs concentrations applied in contaminated ground beef were 1.56, 3.125 and 6.25% (w/v) based on MIC levels and possible activity reductions by food constituents. The bacteria populations were significantly reduced (p ? 0.05) after one day of storage in ground meat samples treated with clove and lemongrass EOs at concentrations of 1.56%. There were no significant counts of L. monocytogenes in samples at the other concentrations of the two oils applied after the second day of storage. The sensory acceptability evaluation of the bovine ground meat samples treated with EOs showed that the addition at concentrations higher than 1.56% promote undesirable alterations of taste, odor and characteristic color. The application of EOs at low concentrations in food products can be used in combination with other preservation methods, such as refrigeration, to control pathogens and spoilage bacteria during shelf-life; which goes according to current market trends, where consumers are requesting natural products. PMID:24294222

de Oliveira, Thales Leandro Coutinho; das Graças Cardoso, Maria; de Araújo Soares, Rodrigo; Ramos, Eduardo Mendes; Piccoli, Roberta Hilsdorf; Tebaldi, Victor Maximiliano Reis

2013-01-01

183

Dimeric pyrrolidinoindoline-type alkaloids with melanogenesis inhibitory activity in flower buds of Chimonanthus praecox.  

PubMed

A methanol extract of the flower buds of Chimonanthus praecox (L.) Link (Calycanthaceae) demonstrated inhibitory effects on melanogenesis in theophylline-stimulated murine B16 melanoma 4A5 cells. From the extract, five dimeric pyrrolidinoindoline alkaloids and four sesquiterpenes were isolated, together with 16 known compounds. Among them, (-)-chimonanthine (1, IC50 = 0.93 ?M), (-)-folicanthine (2, 1.4 ?M), and (-)-calycanthidine (3, 1.8 ?M) showed potent inhibitory effects without notable cytotoxicity at the effective concentrations. The most potent alkaloid (1) inhibited both tyrosinase and tyrosine-related protein-1 mRNA expressions, to which the melanogenesis inhibitory activity would be ascribable. PMID:24668298

Morikawa, Toshio; Nakanishi, Yusuke; Ninomiya, Kiyofumi; Matsuda, Hisashi; Nakashima, Souichi; Miki, Hisako; Miyashita, Yu; Yoshikawa, Masayuki; Hayakawa, Takao; Muraoka, Osamu

2014-07-01

184

Immune inhibitory receptors : regulated expression and suppression  

Microsoft Academic Search

The immune system protects against disease by identifying and eliminating pathogens, while leaving healthy host cells unaffected. Regulatory mechanisms are required to prevent excess or inappropriate immune cell activation and to ultimately terminate the immune response, thereby restoring homeostasis. One important regulatory mechanism is the expression of immune inhibitory receptors, which suppress activation signals initiated by immune receptors. Immune inhibitory

T. A. M. Steevels

2011-01-01

185

Inhibitory Effects of Gynostemma Pentaphyllum on the UV Induction of Bacteriophage ? in Lysogenic Escherichia coli  

Microsoft Academic Search

Effects of gynostemma pentaphyllum (GP) on the bacteriophage ? induced by ultraviolet (UV) irradiation have been studied.\\u000a The results showed that GP could inhibit the UV induction of bacteriophage ? in lysogenic cells. The inhibitory effects were\\u000a dependent on the concentration and the reaction time of GP, and were efficient at 40?125 ?g ml?1 for 10 min. The inhibitory rate

Suhua Zhu; Chengxiang Fang; Shiqiao Zhu; Fang Peng; Luozhen Zhang; Chengpeng Fan

2001-01-01

186

Inhibitory effect of corn silk on skin pigmentation.  

PubMed

In this study, the inhibitory effect of corn silk on melanin production was evaluated. This study was performed to investigate the inhibitory effect of corn silk on melanin production in Melan-A cells by measuring melanin production and protein expression. The corn silk extract applied on Melan-A cells at a concentration of 100 ppm decreased melanin production by 37.2% without cytotoxicity. This was a better result than arbutin, a positive whitening agent, which exhibited a 26.8% melanin production inhibitory effect at the same concentration. The corn silk extract did not suppress tyrosinase activity but greatly reduced the expression of tyrosinase in Melan-A cells. In addition, corn silk extract was applied to the human face with hyperpigmentation, and skin color was measured to examine the degree of skin pigment reduction. The application of corn silk extract on faces with hyperpigmentation significantly reduced skin pigmentation without abnormal reactions. Based on the results above, corn silk has good prospects for use as a material for suppressing skin pigmentation. PMID:24595276

Choi, Sang Yoon; Lee, Yeonmi; Kim, Sung Soo; Ju, Hyun Min; Baek, Ji Hwoon; Park, Chul-Soo; Lee, Dong-Hyuk

2014-01-01

187

Probing inhibitory effects of nanocrystalline cellulose: inhibition versus surface charge.  

PubMed

NCC derived from different biomass sources was probed for its plausible cytotoxicity by electric cell-substrate impedance sensing (ECIS). Two different cell lines, Spodoptera frugiperda Sf9 insect cells and Chinese hamster lung fibroblast V79, were exposed to NCC and their spreading and viability were monitored and quantified by ECIS. Based on the 50%-inhibition concentration (ECIS(50)), none of the NCC produced was judged to have any significant cytotoxicity on these two cell lines. However, NCC derived from flax exhibited the most pronounced inhibition on Sf9 compared to hemp and cellulose powder. NCCs from flax and hemp pre-treated with pectate lyase were also less inhibitory than NCCs prepared from untreated flax and hemp. Results also suggested a correlation between the inhibitory effect and the carboxylic acid contents on the NCC. PMID:22252333

Male, Keith B; Leung, Alfred C W; Montes, Johnny; Kamen, Amine; Luong, John H T

2012-02-21

188

Estimating latency from inhibitory input.  

PubMed

Stimulus response latency is the time period between the presentation of a stimulus and the occurrence of a change in the neural firing evoked by the stimulation. The response latency has been explored and estimation methods proposed mostly for excitatory stimuli, which means that the neuron reacts to the stimulus by an increase in the firing rate. We focus on the estimation of the response latency in the case of inhibitory stimuli. Models used in this paper represent two different descriptions of response latency. We consider either the latency to be constant across trials or to be a random variable. In the case of random latency, special attention is given to models with selective interaction. The aim is to propose methods for estimation of the latency or the parameters of its distribution. Parameters are estimated by four different methods: method of moments, maximum-likelihood method, a method comparing an empirical and a theoretical cumulative distribution function and a method based on the Laplace transform of a probability density function. All four methods are applied on simulated data and compared. PMID:24962079

Levakova, Marie; Ditlevsen, Susanne; Lansky, Petr

2014-08-01

189

Viral Inhibitory Activity of Polyvinylpyrrolidone.  

National Technical Information Service (NTIS)

The investigation was undertaken on the discovery that PVP, in non-toxic concentrations, affords some protection against the cytopathogenic effects in KB cells caused by infection with herpes simplex and Coxsackie B viruses when the cultures are treated w...

B. S. Michaels G. H. Waddell D. D. Zinner M. M. Sigel

1966-01-01

190

Amniotic Fluid Exhibits an Innate Inhibitory Activity Against HIV Type 1 Replication in Vitro  

PubMed Central

Abstract Indirect evidence suggests that amniotic fluid (AF) may play a role in the pathogenesis of in utero HIV-1 transmission. The purpose of this study was to evaluate the potential innate inhibitory role of AF on HIV replication, which may contribute to protection of the fetus against intrauterine transmission. AF was collected from term HIV-1-negative women undergoing scheduled cesarean section. The inhibitory effect of AF against HIV-1BA-L replication was tested in vitro with or without the addition of protease inhibitor cocktail (PIC) in PHA-stimulated PBMC cultures. Quantitative measurement of human neutrophil peptides 1-3 (HNP1-3) was performed on all AF samples, using an ELISA assay. AF exhibited a dose-dependent inhibitory activity against HIV-1BA-L replication, with all samples (n=12) reaching significant inhibitory effect using 50% AF. In vitro, this activity decreased over time, but was able to be sustained with the addition of PIC. The HNP1-3 concentration in AF samples (n=12) ranged from undetectable (<41?pg/ml, n=3) to >250,000?pg/ml with a median of 5,146?pg/ml. AF exhibited a significant and dose-dependent innate inhibitory activity against HIV-1 replication, which was present in all AF samples tested. This effect was prolonged in the presence of PIC, suggesting that the inhibitory factor was in the cell-free protein fraction. The HNP1-3 concentration in AF was in the subinhibitory range for HIV with no correlation between its concentration and the HIV-1 inhibitory activity. These data show the presence of a significant innate inhibitory activity against HIV in AF.

Farzin, Azadeh; Boyer, Pamela; Ank, Bonnie; Nielsen-Saines, Karin

2013-01-01

191

Endogenous cannabinoid signaling at inhibitory interneurons.  

PubMed

Significant progress has been made in our understanding of how endogenous cannabinoids (eCBs) signal at excitatory and inhibitory synapses in the central nervous system (CNS). This review discusses how eCBs regulate inhibitory interneurons, their synapses, and the networks in which they are embedded. eCB signaling plays a pivotal role in brain physiology by means of their synaptic signal transduction, spatiotemporal signaling profile, routing of information through inhibitory microcircuits, and experience-dependent plasticity. Understanding the normal processes underlying eCB signaling is beginning to shed light on how their dysregulation contributes to disease. PMID:24650503

Younts, Thomas J; Castillo, Pablo E

2014-06-01

192

Interpreting 10Be changes during the Maunder Minimum  

Microsoft Academic Search

Beryllium-10 archives are important resources for understanding how solar activity may have varied in the past. Climate simulations using the Goddard Institute for Space Studies ModelE general circulation model are used to calibrate the impacts of production changes, solar forcings, and volcanic aerosol forcing on 10Be concentration during periods such as the Maunder Minimum (1645–1715 A.D.). We find that for

Christy V. Field; Gavin A. Schmidt; Drew T. Shindell

2009-01-01

193

Minimum Competence As An Individual Right.  

ERIC Educational Resources Information Center

After reviewing three current approaches to handling students who fail to meet minimum competency standards, the author proposes a new approach to minimum competency testing. The three common reactions are: (1) doing nothing to help failing students; (2) denying students their high school diplomas; and (3) requiring students to take remedial…

Feldmesser, Robert A.

194

Minimum entropy approach for multisensor data fusion  

Microsoft Academic Search

In this paper, we present a minimum entropy fusion approach for multisensor data fusion in non-Gaussian environments. We represent the fused data in the form of the weighted sum of the multisensor outputs and use the varimax norm as the information measure. The optimum weights are obtained by maximizing the varimax norm of the fused data. The minimum entropy fusion

Yifeng Zhou; Henry Leung

1997-01-01

195

50 CFR 648.143 - Minimum sizes.  

Code of Federal Regulations, 2010 CFR

...STATES Management Measures for the Black Sea Bass Fishery § 648.143 Minimum sizes. (a) The minimum size for black sea bass is 11 inches (27.94 cm...fish for, possess, land or retain black sea bass in or from U.S....

2009-10-01

196

50 CFR 648.143 - Minimum sizes.  

Code of Federal Regulations, 2010 CFR

...STATES Management Measures for the Black Sea Bass Fishery § 648.143 Minimum sizes. (a) The minimum size for black sea bass is 11 inches (27.94 cm...fish for, possess, land or retain black sea bass in or from U.S....

2010-10-01

197

The Minimum Flux Corona; Theory or Concept.  

National Technical Information Service (NTIS)

The reply to the criticisms of the minimum flux theory is discussed. These criticisms are correct in substance, as well as in detail. Counter arguments that the minimum flux corona theory is untenable, because of errors in its formulation, are presented.

J. H. Underwood S. K. Antiochos

1980-01-01

198

Adaptive minimum bit-error-rate filtering  

Microsoft Academic Search

Adaptive filtering has traditionally been developed based o n the minimum mean square error (MMSE) principle and has found ever-increasing applications in communications. The paper develops adaptive filtering based on an alternative minimum bit error rate (MBER) criterion for communication applications. It is shown that the MBER fil tering exploits the non-Gaussian distribution of filter output effectively and, consequentl y,

S. Chen

2004-01-01

199

Adaptive minimum bit-error rate beamforming  

Microsoft Academic Search

An adaptive beamforming technique is proposed based on directly minimizing the bit-error rate (BER). It is demonstrated that this minimum BER (MBER) approach utilizes the antenna array elements more intelligently than the standard minimum mean square error (MMSE) approach. Consequently, MBER beamforming is capable of providing significant performance gains in terms of a reduced BER over MMSE beamforming. A block-data

Sheng Chen; N. N. Ahmad; Lajos Hanzo

2005-01-01

200

MINIMUM MODULI IN VON NEUMANN ALGEBRAS  

Microsoft Academic Search

In this paper we answer a question raised in [12] in the affirmative, namely that the essential minimum modulus of an element in a von Neumann algebra, relative to any norm closed two-sided ideal, is equal to the minimum modulus of the element perturbed by an element from the ideal. As a corollary of this result, we extend some basic

Perumal Gopalraj; Anton StröH

2001-01-01

201

Rapid, learning-induced inhibitory synaptogenesis in murine barrel field  

PubMed Central

The structure of neurones changes during development and in response to injury or alteration in sensory experience. Changes occur in the number, shape and dimensions of dendritic spines together with their synapses. However, precise data on these changes in response to learning are sparse. Here, we show using quantitative transmission electron microscopy that a simple form of learning involving mystacial vibrissae results in about 70% increase in the density of inhibitory synapses on spines of neurones located in layer IV barrels that represent the stimulated vibrissae. The spines contain one asymmetrical (excitatory) and one symmetrical (inhibitory) synapse (double-synapse spines) and their density increases 3-fold due to learning with no apparent change in the density of asymmetrical synapses. This effect seems to be specific for learning as pseudoconditioning (where the conditioned and unconditioned stimuli are delivered at random) does not lead to the enhancement of symmetrical synapses, but instead results in an up-regulation of asymmetrical synapses on spines. Symmetrical synapses of cells located in barrels receiving the conditioned stimulus show also a greater concentration of ?-amino-butyric acid (GABA) in their presynaptic terminals. These results indicate that the immediate effect of classical conditioning in the ‘conditioned’ barrels is rapid, pronounced and inhibitory.

Jasinska, M.; Siucinska, E.; Cybulska-Klosowicz, A.; Pyza, E.; Furness, D.N.; Kossut, M.; Glazewski, S.

2010-01-01

202

Free Energies of Molecular Bound States in Lipid Bilayers: Lethal Concentrations of Antimicrobial Peptides  

PubMed Central

Abstract The lipid matrix, or the lipid bilayer, of cell membranes is a natural binding site for amphipathic molecules, including antimicrobial peptides, pore-forming proteins, and many drugs. The unique property of pore-forming antimicrobial peptides is that they exhibit a threshold concentration (called the lethal concentration or the minimum inhibitory concentration) for activity, below which no effect is seen. Without this property, antimicrobial peptides would not be effective self-defense weapons, because they would have harmed all cells at any concentration. The question is what gives rise to this unique property? This study provides a free energy description for the origin of a threshold concentration. The same free energy applied differently also explains the binding of drugs that shows no threshold concentrations. The idea is compared with theories of micellar solutions that require a large oligomer size (n ? 15) to achieve a threshold concentration. The elasticity of lipid bilayers makes the phenomena in membranes different. The majority of antimicrobial peptides have a large negative binding energy to the bilayer interface, but the binding causes an expansion in the membrane area, or equivalently a thinning in the membrane thickness. This elastic energy of membrane thinning elevates the energy level of interfacial binding with the peptide concentration, hence gives rise to a threshold concentration for forming pores containing as few as four peptides.

Huang, Huey W.

2009-01-01

203

Inhibitory receptors, ITIM sequences and phosphatases  

Microsoft Academic Search

A diverse group of inhibitory receptors, including Fc?RII, killer cell inhibitory receptors, and B22, shares an immunoreceptor tyrosine-based inhibition motif (ITIM). Recent studies have shown that this motif, when phosphorylated on tyrosine, forms a docking site for the Src homology 2 recognition domains of the protein tyrosine phosphatase SHP-1 and the inositol 5-phosphatase SHIP. A similar motif in cytotoxic T-lymphocyte

Jay C Unkeless; Jie Jin

1997-01-01

204

Minimum-Variance Reduced-Order Estimation Algorithms from Pontrygin's Minimum Principle. Abstract Only.  

National Technical Information Service (NTIS)

A uniform derivation of minimum-variance reduced-order (MVRO) filter-smoother algorithms from Pontrygin's Minimum Principle is presented. An appropriate performance index for a general class of reduced order estimation problem is formulated herein to yiel...

Y. S. Ebrahimi

1989-01-01

205

[Concentration of cefamandole in human renal parenchyma (author's transl)].  

PubMed

(6R-[6alpha,7beta(R)])-7-[(hydroxyphenylacetyl)amino]-3-([(1-methyl-1H-tetrazol-5-yl)-thio]methyl)-8-oxo-5-thia-1-azabicyclo[4,2,0]oct-2-ene-2-carbonic acid (cefamandole) levels have been determined in human renal tissue, serum, and urine of 17 patients undergoing therapeutic nephrectomies after 3 i.v. applications of 2 g cefamandole. As far as possible levels of renal cortex and renal medulla were investigated separately. The concentrations of the antibiotic in human renal tissues, removed in the interval from 2 h 10 min to 6 h 25 min after last application of the drug, were distinctly above the minimum inhibitory concentrations of most bacterial strains responsible for urinary tract infections and cases of chronic pyelonephritis. Concentrations of the drug were usually lower in renal parenchyma alterated by chronic inflammatory processes than in "normal tissue" of tumor kidneys. With separate determinations of drug levels in the cortical and medullary regions concentrations of the drug were usually higher in the cortical part of the kidney. PMID:7198478

Kroening, U; Brückner, O; Nagel, R

1981-01-01

206

Rat lens aldose reductase inhibitory constituents of Nelumbo nucifera stamens.  

PubMed

Aldose reductase, the principal enzyme of the polyol pathway, has been shown to play an important role in the complications associated with diabetes. A methanol extract of the stamens of Nelumbo nucifera Gaertn. was shown to exert an inhibitory effect on rat lens aldose reductase (RLAR), and thus was fractionated using several organic solvents, including dichloromethane, ethyl acetate and n-butanol. The ethyl acetate-soluble fraction, which manifested potent RLAR-inhibitory properties, was then purified further via repeated measures of silica gel and Sephadex LH-20 column chromatography. Thirteen flavonoids: kaempferol (1) and seven of its glycosides (2-9), myricetin 3',5'-dimethylether 3-O-beta-d-glucopyranoside (10), quercetin 3-O-beta-d-glucopyranoside (11) and two isorhamnetin glycosides (12, 13) were isolated from N. nucifera, as well as four non-flavonoid compounds: adenine (14), myo-inositol (15), arbutin (16) and beta-sitosterol glucopyranoside (17). These compounds were all assessed with regard to their RLAR-inhibitory properties. Among the isolated flavonoids, those harboring 3-O-alpha-l-rhamnopyranosyl-(1-->6)-beta-d-glucopyranoside groups in their C rings, including kaempferol 3-O-alpha-l-rhamnopyranosyl-(1-->6)-beta-d-glucopyranoside (5) and isorhamnetin 3-O-alpha-l-rhamnopyranosyl-(1-->6)-beta-d-glucopyranoside (13), were determined to exhibit the highest degree of rat lens aldose reductase inhibitory activity in vitro, evidencing IC(50) values (concentration required for a 50% inhibition of enzyme activity) of 5.6 and 9.0 microm, respectively. PMID:16881021

Lim, Soon Sung; Jung, Yu Jung; Hyun, Sook Kyung; Lee, Yeon Sil; Choi, Jae Sue

2006-10-01

207

12 CFR 1750.4 - Minimum capital requirement computation.  

Code of Federal Regulations, 2010 CFR

... 2010-01-01 false Minimum capital requirement computation. 1750.4 Section...Minimum Capital § 1750.4 Minimum capital requirement computation. (a) The minimum capital requirement for each Enterprise shall be...

2010-01-01

208

49 CFR 387.9 - Financial responsibility, minimum levels.  

Code of Federal Regulations, 2013 CFR

...false Financial responsibility, minimum levels. 387.9 Section 387.9 Transportation...MOTOR CARRIER SAFETY REGULATIONS MINIMUM LEVELS OF FINANCIAL RESPONSIBILITY FOR MOTOR...9 Financial responsibility, minimum levels. The minimum levels of financial...

2013-10-01

209

49 CFR 387.33 - Financial responsibility, minimum levels.  

Code of Federal Regulations, 2013 CFR

...false Financial responsibility, minimum levels. 387.33 Section 387.33 Transportation...MOTOR CARRIER SAFETY REGULATIONS MINIMUM LEVELS OF FINANCIAL RESPONSIBILITY FOR MOTOR...33 Financial responsibility, minimum levels. The minimum levels of financial...

2013-10-01

210

Solar wind structure during the solar minimums : Comparison between the cycle 22/23 minimum and 23/24 minimum  

NASA Astrophysics Data System (ADS)

In the solar cycle 23/24 minimum, the solar wind structure was specially different from the one observed in the previous minimum. In this period the region emanating fast solar winds was distributed not only near the polar region but also near the equatorial region while the region emanating slow solar winds extended more to the polar region than in the previous minimum. In this study we perform a global three-dimensional (3D) magnetohydrodynamic simulation of the solar winds during the Carrington rotation (CR) 1912 (22/23 minimum) and 2071 (23/24 minimum) to clarify a difference in 3D flow structure and magnetic field configuration between these two minimums. The simulations have been performed by using the finite volume total variation diminishing (TVD) scheme with a unstructured tetrahedron grid system, which enables to avoid the singularity at the poles in the spherical coordinate system (Tanaka 1995 ). We will compare the simulation results with some observations such as ACE satellite data and Interplanetary scintillation (IPS) provided by the Solar Terrestrial Environment Laboratory (STEL), Nagoya University in Japan. Through this comparison we investigate a suitable form of heat source function where the flux expansion factor may play a key role (Nakamizo et al. 2009).

An, J.; Inoue, S.; Magara, T.; Lee, H.; Kang, J.

2012-12-01

211

Microbial oceanography of anoxic oxygen minimum zones.  

PubMed

Vast expanses of oxygen-deficient and nitrite-rich water define the major oxygen minimum zones (OMZs) of the global ocean. They support diverse microbial communities that influence the nitrogen economy of the oceans, contributing to major losses of fixed nitrogen as dinitrogen (N(2)) and nitrous oxide (N(2)O) gases. Anaerobic microbial processes, including the two pathways of N(2) production, denitrification and anaerobic ammonium oxidation, are oxygen-sensitive, with some occurring only under strictly anoxic conditions. The detection limit of the usual method (Winkler titrations) for measuring dissolved oxygen in seawater, however, is much too high to distinguish low oxygen conditions from true anoxia. However, new analytical technologies are revealing vanishingly low oxygen concentrations in nitrite-rich OMZs, indicating that these OMZs are essentially anoxic marine zones (AMZs). Autonomous monitoring platforms also reveal previously unrecognized episodic intrusions of oxygen into the AMZ core, which could periodically support aerobic metabolisms in a typically anoxic environment. Although nitrogen cycling is considered to dominate the microbial ecology and biogeochemistry of AMZs, recent environmental genomics and geochemical studies show the presence of other relevant processes, particularly those associated with the sulfur and carbon cycles. AMZs correspond to an intermediate state between two "end points" represented by fully oxic systems and fully sulfidic systems. Modern and ancient AMZs and sulfidic basins are chemically and functionally related. Global change is affecting the magnitude of biogeochemical fluxes and ocean chemical inventories, leading to shifts in AMZ chemistry and biology that are likely to continue well into the future. PMID:22967509

Ulloa, Osvaldo; Canfield, Donald E; DeLong, Edward F; Letelier, Ricardo M; Stewart, Frank J

2012-10-01

212

Microbial oceanography of anoxic oxygen minimum zones  

PubMed Central

Vast expanses of oxygen-deficient and nitrite-rich water define the major oxygen minimum zones (OMZs) of the global ocean. They support diverse microbial communities that influence the nitrogen economy of the oceans, contributing to major losses of fixed nitrogen as dinitrogen (N2) and nitrous oxide (N2O) gases. Anaerobic microbial processes, including the two pathways of N2 production, denitrification and anaerobic ammonium oxidation, are oxygen-sensitive, with some occurring only under strictly anoxic conditions. The detection limit of the usual method (Winkler titrations) for measuring dissolved oxygen in seawater, however, is much too high to distinguish low oxygen conditions from true anoxia. However, new analytical technologies are revealing vanishingly low oxygen concentrations in nitrite-rich OMZs, indicating that these OMZs are essentially anoxic marine zones (AMZs). Autonomous monitoring platforms also reveal previously unrecognized episodic intrusions of oxygen into the AMZ core, which could periodically support aerobic metabolisms in a typically anoxic environment. Although nitrogen cycling is considered to dominate the microbial ecology and biogeochemistry of AMZs, recent environmental genomics and geochemical studies show the presence of other relevant processes, particularly those associated with the sulfur and carbon cycles. AMZs correspond to an intermediate state between two “end points” represented by fully oxic systems and fully sulfidic systems. Modern and ancient AMZs and sulfidic basins are chemically and functionally related. Global change is affecting the magnitude of biogeochemical fluxes and ocean chemical inventories, leading to shifts in AMZ chemistry and biology that are likely to continue well into the future.

Ulloa, Osvaldo; Canfield, Donald E.; DeLong, Edward F.; Letelier, Ricardo M.; Stewart, Frank J.

2012-01-01

213

Proactive and reactive inhibitory control in rats  

PubMed Central

Inhibiting actions inappropriate for the behavioral context, or inhibitory control, is essential for survival and involves both reactively stopping the current prepared action and proactively adjusting behavioral tendencies to increase future performance. A powerful paradigm widely used in basic and clinical research to study inhibitory control is the stop signal task (SST). Recent years have seen a surging interest in translating the SST to rodents to study the neural mechanisms underlying inhibitory control. However, significant differences in task designs and behavioral strategies between rodent and primate studies have made it difficult to directly compare the two literatures. In this study, we developed a rodent-appropriate SST and characterized both reactive and proactive control in rats. For reactive inhibitory control, we found that, unlike in primates, incorrect stop trials in rodents result from two independent types of errors: an initial failure-to-stop error or, after successful stopping, a subsequent failure-to-wait error. Conflating failure-to-stop and failure-to-wait errors systematically overestimates the covert latency of reactive inhibition, the stop signal reaction time (SSRT). To correctly estimate SSRT, we developed and validated a new method that provides an unbiased SSRT estimate independent of the ability to wait. For proactive inhibitory control, we found that rodents adjust both their reaction time and the ability to stop following failure-to-wait errors and successful stop trials, but not after failure-to-stop errors. Together, these results establish a valid rodent model that utilizes proactive and reactive inhibitory control strategies similar to primates, and highlight the importance of dissociating initial stopping from subsequent waiting in studying mechanisms of inhibitory control using rodents.

Mayse, Jeffrey D.; Nelson, Geoffrey M.; Park, Pul; Gallagher, Michela; Lin, Shih-Chieh

2014-01-01

214

Impact of the Minimum Wage on Compression.  

ERIC Educational Resources Information Center

Assesses the impact of increases in the minimum wage on salary schedules, provides guidelines for creating a philosophy to deal with the impact, and outlines options and presents recommendations. (IRT)

Wolfe, Michael N.; Candland, Charles W.

1979-01-01

215

7 CFR 4280.136 - Minimum retention.  

...SERVICE AND RURAL UTILITIES SERVICE, DEPARTMENT OF AGRICULTURE LOANS AND GRANTS Rural Energy for America Program General Renewable Energy System and Energy Efficiency Improvement Guaranteed Loans § 4280.136 Minimum retention....

2014-01-01

216

Tracked Vehicle Acceleration: Maximum and Minimum Speeds.  

National Technical Information Service (NTIS)

This document describes procedures for conducting acceleration and maximum and minimum speed tests of tracked vehicles. Acceleration and maximum speed are basic measures of vehicle power; they define the ability of a vehicle to execute a change in locatio...

1987-01-01

217

7 CFR 35.11 - Minimum requirements.  

Code of Federal Regulations, 2010 CFR

...Sweden, Switzerland, Wales, West Germany, Yugoslavia), or Greenland shall meet each applicable minimum requirement of the U...destination, other than destinations in Japan, Europe, Greenland, Canada, or Mexico, shall meet each applicable...

2009-01-01

218

7 CFR 35.11 - Minimum requirements.  

Code of Federal Regulations, 2010 CFR

...Sweden, Switzerland, Wales, West Germany, Yugoslavia), or Greenland shall meet each applicable minimum requirement of the U...destination, other than destinations in Japan, Europe, Greenland, Canada, or Mexico, shall meet each applicable...

2010-01-01

219

Minimum Fuel Trajectories with Soft Landings.  

National Technical Information Service (NTIS)

Minimum fuel trajectories for rocket flights with soft landings in a uniform gravitational field are presented as functions of two parameters. The solutions are valid for any uniform gravitational field, rocket fuel, and burning rate. The problem is formu...

O. J. Manci

1964-01-01

220

Principals' Attitudes toward Minimum Competency Testing.  

ERIC Educational Resources Information Center

Alabama's public high school principals support the concept of minimum competency testing for students but are reluctant to allocate time and money to this effort at the expense of other curricular endeavors, according to a recent survey. (PGD)

Stronge, James H.

1985-01-01

221

Minimum Property Standards and Local Housing Markets.  

National Technical Information Service (NTIS)

This report describes the impact on builder costs and housing markets of selected items in the Federal Housing Administration's (FHA's) Minimum Property Standards (MPS). MPS consists of a large body of technical specifications that must be met by building...

J. A. Tuccillo R. Dubinsky

1982-01-01

222

Maximum, Minimum, and Current Temperature Protocol  

NSDL National Science Digital Library

The purpose of this activity is to measure air (and optionally soil) temperature within one hour of solar noon and the maximum and minimum air temperatures for the previous 24 hours. Intended outcomes are that students will learn to read minimum, maximum, and current temperatures using a U-shaped thermometer, understand diurnal and annual temperature variations, and recognize factors that influence atmospheric temperatures. Supporting background materials for both student and teacher are included.

The GLOBE Program, UCAR (University Corporation for Atmospheric Research)

2003-08-01

223

Microbial adhesion of Cryptosporidium parvum: Identification of a colostrum-derived inhibitory lipid  

PubMed Central

We previously described an unidentified lipid purified from calf small intestine that inhibits the in vitro adhesion of Cryptosporidium parvum sporozoites to host cells [Johnson JK, Schmidt J, Gelberg HB, Kuhlenschmidt MS. Microbial adhesion of Cryptosporidium parvum sporozoites: purification of an inhibitory lipid from bovine mucosa. J Parasitol 2004;90:980–90]. Intestinal mucosa from some calves, however, failed to yield this bioactive lipid. Accordingly, we examined other potential sources, especially dietary sources, of the inhibitory lipid and discovered it was principally derived from bovine colostrum. Interestingly, fresh colostrum yielded little or no inhibitory lipid, however, the lipid was found in relatively large quantities following incubation of colostrum with the aqueous fraction of calf intestinal contents. Using FAB-MS and NMR analysis, the sporozoite inhibitory lipid (SIL) was identified as oleic acid, a monounsaturated fatty acid likely released from colostrum triglycerides and phospholipids by digestion in the lumen of the calf small intestine. Oleic acid dose-dependently inhibited in vitro sporozoite–host cell adhesion with an inhibitory constant (IC50) of approximately 5 ?M. Comparison of oleic acid with other C-18 fatty acids revealed linolenic, but not stearic acid, also displayed potent inhibitory activity. Neither linolenic nor oleic acid, however, affect either sporozoite or host cell viability at concentrations that inhibit sporozoite adhesion. These results suggest certain colostrum-derived long-chain fatty acids may serve as natural inhibitors of the early steps in C. parvum sporozoite–host cell interactions.

Schmidt, Joann; Kuhlenschmidt, Mark S.

2008-01-01

224

Inhibitory activities of 2-pyridinecarboxylic acid analogs on phytogrowth and enzymes.  

PubMed

Five 2-pyridinecarboxylic acid-related compounds (1, 2 and 5-7) showed germination inhibition against the seed of Brassica campestris L. subsp. rapa HOOK fil et ANDERS at a concentration of 5.0 x 10(-4) M. These compounds also demonstrated inhibitory activity on the growth of the root of this plant at a concentration of 3.0 x 10(-4) M; among these compounds, 2-pyridylacetic acid (5) showed the strongest inhibitory activity, and the effect was slightly stronger than that of sodium 2,4-dichlorophenoxyacetate (2,4-D) used as a positive control. The amounts of chlorophyll in the cotyledons of this plant treated with these active compounds was lower than that of the control group. Four compounds (1 and 5-7) with germination inhibition also showed inhibitory activities against alpha-amylase and carboxypeptidase A, and 5 was the strongest inhibitor toward both enzymes. PMID:10598034

Sakagami, Y; Tsujibo, H; Hirai, Y; Yamada, T; Numata, A; Inamori, Y

1999-11-01

225

Screening for acetylcholinesterase inhibitory activity in plants used in Thai traditional rejuvenating and neurotonic remedies.  

PubMed

Acetylcholinesterase (AChE) inhibitor has been used as a drug for the symptomatic treatment of Alzheimer's disease. In order to search for new AChE inhibitors, 32 plants used in Thai traditional rejuvenating and neurotonic remedies were collected. The plant methanolic extracts were tested for AChE inhibitory activity using Ellman's colorimetric method in 96-welled microplates. The results showed that the methanolic extracts from roots of Stephania suberosa Forman. and Tabernaemontana divaricata (L.) R.Br. ex Roem. & Schult. at concentration of 0.1 mg/ml inhibited more than 90% of AChE activity. At the same concentration, four extracts, i.e. stems of Piper interruptum Opiz., seeds of Piper nigrum L., rootbarks of Butea superba Roxb. and roots of Cassia fistula L. extracts showed 50-65% inhibitory activity on AChE. The rest of the extracts showed the AChE inhibitory activity below 50%. PMID:14611889

Ingkaninan, Kornkanok; Temkitthawon, Prapapan; Chuenchom, Kanchanaporn; Yuyaem, Thitaree; Thongnoi, Warawit

2003-12-01

226

The inhibitory effect of Mesembryanthemum edule (L.) bolus essential oil on some pathogenic fungal isolates  

PubMed Central

Background Mesembryanthemum edule is a medicinal plant which has been indicated by Xhosa traditional healers in the treatment HIV associated diseases such as tuberculosis, dysentery, diabetic mellitus, laryngitis, mouth infections, ringworm eczema and vaginal infections. The investigation of the essential oil of this plant could help to verify the rationale behind the use of the plant as a cure for these illnesses. Methods The essential oil from M. edule was analysed by GC/MS. Concentration ranging from 0.005 - 5 mg/ml of the hydro-distilled essential oil was tested against some fungal strains, using micro-dilution method. The plant minimum inhibitory activity on the fungal strains was determined. Result GC/MS analysis of the essential oil resulted in the identification of 28 compounds representing 99.99% of the total essential oil. A total amount of 10.6 and 36.61% constituents were obtained as monoterpenes and oxygenated monoterpenes. The amount of sesquiterpene hydrocarbons (3.58%) was low compared to the oxygenated sesquiterpenes with pick area of 9.28%. Total oil content of diterpenes and oxygenated diterpenes detected from the essential oil were 1.43% and 19.24%. The fatty acids and their methyl esters content present in the essential oil extract were found to be 19.25%. Antifungal activity of the essential oil extract tested against the pathogenic fungal, inhibited C. albican, C. krusei, C. rugosa, C. glabrata and C. neoformans with MICs range of 0.02-0.31 mg/ml. the activity of the essential oil was found competing with nystatin and amphotericin B used as control. Conclusion Having accounted the profile chemical constituent found in M. edule oil and its important antifungal properties, we consider that its essential oil might be useful in pharmaceutical and food industry as natural antibiotic and food preservative.

2014-01-01

227

Analysis of the neutral polysaccharide fraction of MCP and its inhibitory activity on galectin-3.  

PubMed

The pH-modified citrus pectin (MCP) has been demonstrated to inhibit galectin-3 in cancer progression. The components and structures of MCP related to this inhibition remained unknown. In this paper, we fractionated MCP on DEAE-cellulose column into a homogenous neutral fraction MCP-N (about 20 kDa) and a pectin mixture fraction MCP-A (wide molecular distribution on Sepharose CL-6B chromatography). Both MCP-N and MCP-A inhibited hemagglutination mediated by galectin-3 with minimum inhibition concentration (MIC) 625 and 0.5 ?g/ml, respectively. MCP-N was identified to be a type I arabinogalactan (AG-I) with a main chain of ?-1?4-galactan. MCP-N was digested by ?-L-arabinofuranosidase to give its main chain structure fraction (M-galactan, around 18 kDa), which was more active than the original molecule, MIC 50 ?g/ml. The acidic degradation of M-galactan increased the inhibitory activity, MIC about 5 times lower than M-galactan. These results above showed that the functional motif of the ?-1?4-galactan fragment might lie in the terminal residues rather than in the internal region of the chain. Therefore, MCP-N and its degraded products might be developed to new potential galectin-3 inhibitors. This is the first report concerning the fractionation of MCP and its components on galectin-3 inhibition. The information provided in this paper is valuable for screening more active galectin-3 inhibitors from natural polysaccharides. PMID:22562786

Gao, Xiaoge; Zhi, Yuan; Zhang, Tao; Xue, Huiting; Wang, Xiao; Foday, Anthony D; Tai, Guihua; Zhou, Yifa

2012-05-01

228

Selective cytopheretic inhibitory device with regional citrate anticoagulation and portable sorbent dialysis.  

PubMed

Selective cytopheretic inhibitory device (SCD) therapy is an immunomodulatory treatment provided by a synthetic biomimetic membrane in an extracorporeal circuit, which has shown promise in preclinical large animal models of severe sepsis as well as in clinical trials treating patients with acute kidney injury and multiple organ failure. During SCD therapy, citrate is administered to lower ionized calcium levels in blood for anticoagulation and inhibition of leukocyte activation. Historically, citrate has been known to interfere with sorbent dialysis, therefore, posing a potential issue for the use of SCD therapy with a portable dialysis system. This sorbent dialysis SCD (sorbent SCD) would be well suited for battlefield and natural disaster applications where the water supply for standard dialysis is limited, and the types of injuries in those settings would benefit from SCD therapy. In order to explore the compatibility of sorbent and SCD technologies, a uremic porcine model was tested with the Allient sorbent dialysis system (Renal Solutions Incorporated, Fresenius Medical Care, Warrendale, PA, USA) and concurrent SCD therapy with regional citrate anticoagulation. The hypothesis to be assessed was whether the citrate load required by the SCD could be metabolized prior to recirculation from systemic blood back into the therapeutic circuit. Despite the fact that the sorbent SCD maintained urea clearance without any adverse hematologic events, citrate load for SCD therapy caused an interaction with the sorbent column resulting in elevated, potentially toxic aluminum levels in dialysate and in systemic blood. Alternative strategies to implement sorbent-SCD therapy will be required, including development of alternate urease-sorbent column binding chemistry or further changes to the sorbent-SCD therapeutic circuit along with determining the minimum citrate concentration required for efficacious SCD treatment. PMID:23067378

Pino, Christopher J; Farokhrani, Amin; Lou, Liandi; Smith, Peter L; Johnston, Kimberly; Buffington, Deborah A; Humes, H David

2013-02-01

229

School concentration and school travel  

Microsoft Academic Search

The purpose of the research as described in this Doctor’s thesis is twofold. Firstly it is to define in how far Dutch facilities for primary and secondary education were subjected to spatial concentration during recent decades. Secondly it is intended to assess what this concentration implied for the development of the minimum necessary travel distances to school, with its consequences

E. De Boer

2010-01-01

230

Inhibitory costimulation and anti-tumor immunity  

PubMed Central

Costimulation was originally shown to be important in T-cell activation and effector differentiation. Recent characterization of B7/butyrophilin and members of the CD28 superfamily has revealed a large number of negative costimulatory molecules that dampen T-cell activation and regulate immune tolerance. Some of these molecules have been shown to be upregulated in the tumor microenvironment and may serve as potential targets for augmenting anti-tumor immunity. In this article, we summarize recent developments in the field of inhibitory costimulation and discuss the future direction of therapeutic manipulation of inhibitory costimulation in tumor immunotherapy.

Martin-Orozco, Natalia; Dong, Chen

2007-01-01

231

Preparation of ACE Inhibitory Peptides from Mytilus coruscus Hydrolysate Using Uniform Design  

PubMed Central

The angiotensin-I-converting enzyme (ACE) inhibitory peptides from mussel, Mytilus coruscus, were investigated and the variable factors, protease concentration, hydrolysis time, pH, and temperature, were optimized using Uniform Design, a new statistical experimental method. The results proved that the hydrolysate of alkali proteases had high ACE-inhibitory activity, especially the alkali protease E1. Optimization by Uniform Design showed that the best hydrolysis conditions for preparation of ACE-inhibitory peptides from Mytilus coruscus were protease concentration of 36.0?U/mL, hydrolysis time of 2.7 hours, pH 8.2, and Temperature at 59.5°C, respectively. The verification experiments under optimum conditions showed that the ACE-inhibitory activity (91.3%) were agreed closely with the predicted activity of 90.7%. The amino acid composition analysis of Mytilus coruscus ACE-inhibitory peptides proved that it had high percent of lysine, leucine, glycine, aspartic acid, and glutamic acid.

Wu, Jin-Chao; Cheng, Jie; Shi, Xiao-lai

2013-01-01

232

Potent ?-amylase inhibitory activity of Indian Ayurvedic medicinal plants  

PubMed Central

Background Indian medicinal plants used in the Ayurvedic traditional system to treat diabetes are a valuable source of novel anti-diabetic agents. Pancreatic ?-amylase inhibitors offer an effective strategy to lower the levels of post-prandial hyperglycemia via control of starch breakdown. In this study, seventeen Indian medicinal plants with known hypoglycemic properties were subjected to sequential solvent extraction and tested for ?-amylase inhibition, in order to assess and evaluate their inhibitory potential on PPA (porcine pancreatic ?-amylase). Preliminary phytochemical analysis of the lead extracts was performed in order to determine the probable constituents. Methods Analysis of the 126 extracts, obtained from 17 plants (Aloe vera (L.) Burm.f., Adansonia digitata L., Allium sativum L., Casia fistula L., Catharanthus roseus (L.) G. Don., Cinnamomum verum Persl., Coccinia grandis (L.) Voigt., Linum usitatisumum L., Mangifera indica L., Morus alba L., Nerium oleander L., Ocimum tenuiflorum L., Piper nigrum L., Terminalia chebula Retz., Tinospora cordifolia (Willd.) Miers., Trigonella foenum-graceum L., Zingiber officinale Rosc.) for PPA inhibition was initially performed qualitatively by starch-iodine colour assay. The lead extracts were further quantified with respect to PPA inhibition using the chromogenic DNSA (3, 5-dinitrosalicylic acid) method. Phytochemical constituents of the extracts exhibiting? 50% inhibition were analysed qualitatively as well as by GC-MS (Gas chromatography-Mass spectrometry). Results Of the 126 extracts obtained from 17 plants, 17 extracts exhibited PPA inhibitory potential to varying degrees (10%-60.5%) while 4 extracts showed low inhibition (< 10%). However, strong porcine pancreatic amylase inhibitory activity (> 50%) was obtained with 3 isopropanol extracts. All these 3 extracts exhibited concentration dependent inhibition with IC50 values, viz., seeds of Linum usitatisumum (540 ?gml-1), leaves of Morus alba (1440 ?gml-1) and Ocimum tenuiflorum (8.9 ?gml-1). Acarbose as the standard inhibitor exhibited an IC50 (half maximal inhibitory concentration)value of 10.2 ?gml-1. Phytochemical analysis revealed the presence of alkaloids, tannins, cardiac glycosides, flavonoids, saponins and steroids with the major phytoconstituents being identified by GC-MS. Conclusions This study endorses the use of these plants for further studies to determine their potential for type 2 diabetes management. Results suggests that extracts of Linum usitatisumum, Morus alba and Ocimum tenuiflorum act effectively as PPA inhibitors leading to a reduction in starch hydrolysis and hence eventually to lowered glucose levels.

2011-01-01

233

The minimum principle and visual pattern completion.  

PubMed

The minimum principle states that a perceiver will see the simplest possible interpretation of a pattern. Some theorists of human perception take this principle as a core-explanatory concept. Others hold the view that a perceptual minimum principle is untenable. In two recent extensive surveys of the relevant literature a more differentiated position is taken: the minimum principle is not renounced in a definite way. In the research reported here, an intuitively appealing specification of a minimum principle is tested. An experiment on visual pattern completion was performed in which patterns were presented to subjects who traced the contours of the shapes they saw. It was predicted that there would be a preference for interpretations that describe a pattern as a set of separate shapes with minimal information load as computed by Leeuwenberg's coding language. However, only half of the responses given by the subjects were predicted by this specification of a minimum principle. It was further demonstrated that locally complex interpretations of junctions of contour elements are easily made, but not in order to attain globally minimal interpretations. PMID:2608867

Boselie, F; Wouterlood, D

1989-01-01

234

Refolding of soluble leukemia inhibitory factor receptor fusion protein (gp 190 sol DAF) from urea  

Microsoft Academic Search

The insoluble inclusion bodies of soluble leukemia inhibitory factor receptor fusion protein (gp 190 sol DAF ) was solubilized in 8 M urea on the unfolding transitions, and several factors on the aggregate formation were indirectly analyzed for the refolding of gp 190 sol DAF. Results indicate that the refolding yield can be considerably increased at lowering concentration of the

Houqi Liu; Jean-François Moreau; Norbert Gualde; Jiliang Fu

1997-01-01

235

Effect of leukemia inhibitory factor on bovine embryos produced in vitro under chemically defined conditions  

Microsoft Academic Search

The objective of these experiments was to assess putative embryotrophic effects of leukemia inhibitory factor (LIF) on bovine preimplantation development in chemically defined media. Recombinant human LIF was added to embryo culture media at a concentration of 100ng\\/ml. When added for culture of morulae LIF had no positive effect on the proportion of embryos reaching the blastocyst stage. However, LIF

S Sirisathien; H. J Hernandez-Fonseca; P Bosch; B. R Hollet; J. D Lott; B. G Brackett

2003-01-01

236

The response of Gastric Inhibitory Polypeptide (GIP) and insulin to glucose in duodenal ulcer patients  

Microsoft Academic Search

Summary  The response of Gastric Inhibitory Polypeptide (GIP) and insulin to a 50 g oral glucose tolerance test (OGTT) and an intravenous glucose infusion (IVGI), which copied the changes in plasma glucose concentrations during the OGTT, were measured in 10 patients with duodenal ulcer and in 10 healthy control subjects. The mean responses of GIP and insulin to OGTT were significantly

K. B. Lauritsen; A. J. Moody

1978-01-01

237

Macrophage migration inhibitory factor: molecular, cellular and genetic aspects of a key neuroendocrine molecule  

Microsoft Academic Search

The immunological and neuroendocrine properties of macrophage migration inhibitory factor (MIF) are diverse. In this article we review the known cellular, molecular and genetic properties of MIF that place it as a key regulatory cytokine, acting within both the innate and adaptive immune responses. The unexpected and paradoxical induction of MIF secretion by low concentrations of glucocorticoids is explored. The

R P Donn; D W Ray

2004-01-01

238

Predicting the DPP-IV inhibitory activity pIC?? based on their physicochemical properties.  

PubMed

The second development program developed in this work was introduced to obtain physicochemical properties of DPP-IV inhibitors. Based on the computation of molecular descriptors, a two-stage feature selection method called mRMR-BFS (minimum redundancy maximum relevance-backward feature selection) was adopted. Then, the support vector regression (SVR) was used in the establishment of the model to map DPP-IV inhibitors to their corresponding inhibitory activity possible. The squared correlation coefficient for the training set of LOOCV and the test set are 0.815 and 0.884, respectively. An online server for predicting inhibitory activity pIC50 of the DPP-IV inhibitors as described in this paper has been given in the introduction. PMID:23865065

Gu, Tianhong; Yang, Xiaoyan; Li, Minjie; Wu, Milin; Su, Qiang; Lu, Wencong; Zhang, Yuhui

2013-01-01

239

Predicting the DPP-IV Inhibitory Activity pIC50 Based on Their Physicochemical Properties  

PubMed Central

The second development program developed in this work was introduced to obtain physicochemical properties of DPP-IV inhibitors. Based on the computation of molecular descriptors, a two-stage feature selection method called mRMR-BFS (minimum redundancy maximum relevance-backward feature selection) was adopted. Then, the support vector regression (SVR) was used in the establishment of the model to map DPP-IV inhibitors to their corresponding inhibitory activity possible. The squared correlation coefficient for the training set of LOOCV and the test set are 0.815 and 0.884, respectively. An online server for predicting inhibitory activity pIC50 of the DPP-IV inhibitors as described in this paper has been given in the introduction.

Gu, Tianhong; Yang, Xiaoyan; Li, Minjie; Su, Qiang; Lu, Wencong; Zhang, Yuhui

2013-01-01

240

Minimum energy desynchronizing control for coupled neurons.  

PubMed

We employ optimal control theory to design an event-based, minimum energy, desynchronizing control stimulus for a network of pathologically synchronized, heterogeneously coupled neurons. This works by optimally driving the neurons to their phaseless sets, switching the control off, and letting the phases of the neurons randomize under intrinsic background noise. An event-based minimum energy input may be clinically desirable for deep brain stimulation treatment of neurological diseases, like Parkinson's disease. The event-based nature of the input results in its administration only when it is necessary, which, in general, amounts to fewer applications, and hence, less charge transfer to and from the tissue. The minimum energy nature of the input may also help prolong battery life for implanted stimulus generators. For the example considered, it is shown that the proposed control causes a considerable amount of randomization in the timing of each neuron's next spike, leading to desynchronization for the network. PMID:22903565

Nabi, Ali; Mirzadeh, Mohammad; Gibou, Frederic; Moehlis, Jeff

2013-04-01

241

Minimum Contradiction Matrices in Whole Genome Phylogenies  

PubMed Central

Minimum contradiction matrices are a useful complement to distance-based phylogenies. A minimum contradiction matrix represents phylogenetic information under the form of an ordered distance matrix Yi, jn. A matrix element corresponds to the distance from a reference vertex n to the path (i, j). For an X-tree or a split network, the minimum contradiction matrix is a Robinson matrix. It therefore fulfills all the inequalities defining perfect order: Yi, jn ? Yi,kn, Yk jn ? Yk, In, i ? j ? k < n. In real phylogenetic data, some taxa may contradict the inequalities for perfect order. Contradictions to perfect order correspond to deviations from a tree or from a split network topology. Efficient algorithms that search for the best order are presented and tested on whole genome phylogenies with 184 taxa including many Bacteria, Archaea and Eukaryota. After optimization, taxa are classified in their correct domain and phyla. Several significant deviations from perfect order correspond to well-documented evolutionary events.

Thuillard, Marc

2008-01-01

242

Bilingualism Influences Inhibitory Control in Auditory Comprehension  

ERIC Educational Resources Information Center

Bilinguals have been shown to outperform monolinguals at suppressing task-irrelevant information. The present study aimed to identify how processing linguistic ambiguity during auditory comprehension may be associated with inhibitory control. Monolinguals and bilinguals listened to words in their native language (English) and identified them among…

Blumenfeld, Henrike K.; Marian, Viorica

2011-01-01

243

A Novel Inhibitory Receptor of Platelets  

Cancer.gov

The National Cancer Institute's Molecular Targets Laboratory is seeking statements of capability or interest from parties interested in collaborative research on a novel, inhibitory platelet surface protein known as TREM like Transcript (TLT-1). The collaborative research would be pre-clinical development of a potential therapeutic target for thrombosis and other platelet-associated disorders, as well as immune disorders.

244

Inhibitory Control in Obsessive-Compulsive Disorder  

ERIC Educational Resources Information Center

The clinical features of Obsessive-Compulsive Disorder (OCD) suggest that a fundamental deficit of inhibitory control is intrinsic to the disorder. In this preliminary study, we sought to examine cognitive disinhibition in OCD by using an established laboratory technique. The stop signal task was administered to a higher functioning, untreated…

Krikorian, Robert; Zimmerman, Molly E.; Fleck, David E.

2004-01-01

245

Inhibitory Effects of Beraprost on Platelet Aggregation  

Microsoft Academic Search

We evaluated the inhibitory effects of beraprost, a stable prostacyclin analogue, on platelet aggregation, assessed by two methods of platelet aggregometry. The conventional aggregometry detects changes in light transmission (LT) of a platelet suspension, and a recently developed aggregometry based upon a particle counting principle detects light scattering (LS) generated by platelet aggregates. Since LS is more sensitive than LT

Libo Yang; Yutaka Yatomi; Kaneo Satoh; Yukio Ozaki

1999-01-01

246

The inhibitory factors of implementing internet banks  

Microsoft Academic Search

The purpose of this study is to explore the inhibitory factors that affect the implementation of Internet Banks (IBs) in Taiwan and provide suggestions for the banks that fail to implement internet banks. This study compiles the factors according to Rogers' Innovation Diffusion theory and the result of the literature review. Then, we collect data from the questionnaire survey and

Yu-Chung Hung; Yu-Hsin Lu

2008-01-01

247

Is the current solar activity minimum special?  

NASA Astrophysics Data System (ADS)

Is the current solar activity minimum special? Sami K. Solanki(1,2), Natalie Krivova(1), Luis E. Vieira(1,3) (1) Max Planck Institute for Solar System Research, Katlenburg-Lindau, Germany (2) Kyung-Hee University, Yongin, Gyeonggi, Korea (3) Laboratory for Physics and Chemistry of the Terrestrial Environment/CNRS, Or-leans, France In many respects the current minimum of solar activity is rather different from other minima during the last half century, which has seen the Sun in a state of unusually high activity. This uncommon minimum has fascinated solar physicists. Of particular importance for our understanding is the behaviour of the magnetic field, which is the source of all activity observed in the solar atmosphere, including the heliosphere. Furthermore, the evolution of dark and bright magnetic features on the solar surface modulates the solar irradiance, which could directly influence the Earth's climate. In this presentation observations and models of the evolution of the Sun's magnetic field, sunspots and irradiance are reviewed. After discussing the variation of these quantities over the solar cycle and from cycle to cycle, the current minimum is considered in greater detail. It is compared to earlier minima going back to the Maunder minimum and, in a more averaged sense, to solar activity and irradiance during the whole Holocene. Questions that will be onsidered are: Are we leaving the period of high solar activity (a grand maximum) to enter into a phase of more moderate activity, or even into a grand minimum? How could such a change in the level of the magnetic field and irradiance aid us in gaining further insight into the nature of the Sun's influence on the Earth's climate?

Solanki, Sami K.; Krivova, Natalie; Antunes Vieira, Luis Eduardo

248

Optimization for minimum sensitivity to uncertain parameters  

NASA Technical Reports Server (NTRS)

A procedure to design a structure for minimum sensitivity to uncertainties in problem parameters is described. The approach is to minimize directly the sensitivity derivatives of the optimum design with respect to fixed design parameters using a nested optimization procedure. The procedure is demonstrated for the design of a bimetallic beam for minimum weight with insensitivity to uncertainties in structural properties. The beam is modeled with finite elements based on two dimensional beam analysis. A sequential quadratic programming procedure used as the optimizer supplies the Lagrange multipliers that are used to calculate the optimum sensitivity derivatives. The method was perceived to be successful from comparisons of the optimization results with parametric studies.

Pritchard, Jocelyn I.; Adelman, Howard M.; Sobieszczanski-Sobieski, Jaroslaw

1994-01-01

249

The efficiency of reweighted minimum vector variance  

NASA Astrophysics Data System (ADS)

Minimum vector variance (MVV) is a new robust estimator which possesses the good properties as in minimum covariance determinant (MCD), but with better computational efficiency. However, the highly robust affine equivariant estimators with the best breakdown point commonly have to compensate with low statistical efficiency. Hence, to increase the efficiency while retaining the highest breakdown point, we proceed to improve the MVV estimators in the context of statistical efficiency via reweighted version (RMVV). Interestingly, the reweighted scheme was able to maintain the breakdown point of 0.5 and attained higher efficiency at the normal distribution.

Ali, Hazlina; Yahaya, Sharipah Soaad Syed; Omar, Zurni

2014-06-01

250

Image data compression having minimum perceptual error  

NASA Technical Reports Server (NTRS)

A method for performing image compression that eliminates redundant and invisible image components is described. The image compression uses a Discrete Cosine Transform (DCT) and each DCT coefficient yielded by the transform is quantized by an entry in a quantization matrix which determines the perceived image quality and the bit rate of the image being compressed. The present invention adapts or customizes the quantization matrix to the image being compressed. The quantization matrix comprises visual masking by luminance and contrast techniques and by an error pooling technique all resulting in a minimum perceptual error for any given bit rate, or minimum bit rate for a given perceptual error.

Watson, Andrew B. (inventor)

1995-01-01

251

Image Data Compression Having Minimum Perceptual Error  

NASA Technical Reports Server (NTRS)

A method is presented for performing color or grayscale image compression that eliminates redundant and invisible image components. The image compression uses a Discrete Cosine Transform (DCT) and each DCT coefficient yielded by the transform is quantized by an entry in a quantization matrix which determines the perceived image quality and the bit rate of the image being compressed. The quantization matrix comprises visual masking by luminance and contrast technique all resulting in a minimum perceptual error for any given bit rate, or minimum bit rate for a given perceptual error.

Watson, Andrew B. (Inventor)

1997-01-01

252

Thermal conductivity minimum: a new water anomaly.  

PubMed

We investigate the thermal conductivity of liquid water using computer simulations of the TIP5P model of water. Our simulations show that, in addition to the maximum at high temperatures at constant pressure that it exhibits in experiments, the thermal conductivity also displays a minimum at low temperatures. We find that the temperature of minimum thermal conductivity in supercooled liquid water coincides with the temperature of maximum specific heat. We discuss our results in the context of structural changes in liquid water at low temperatures. PMID:21995422

Kumar, Pradeep; Stanley, H Eugene

2011-12-01

253

Minimum induced drag configurations with jet interaction  

NASA Technical Reports Server (NTRS)

A theoretical method is presented for determining the optimum camber shape and twist distribution for the minimum induced drag in the wing-alone case without prescribing the span loading shape. The same method was applied to find the corresponding minimum induced drag configuration with the upper-surface-blowing jet. Lan's quasi-vortex-lattice method and his wing-jet interaction theory was used. Comparison of the predicted results with another theoretical method shows good agreement for configurations without the flowing jet. More applicable experimental data with blowing jets are needed to establish the accuracy of the theory.

Pao, J. L.; Lan, C. E.

1978-01-01

254

The minimum distance approach to classification  

NASA Technical Reports Server (NTRS)

The work to advance the state-of-the-art of miminum distance classification is reportd. This is accomplished through a combination of theoretical and comprehensive experimental investigations based on multispectral scanner data. A survey of the literature for suitable distance measures was conducted and the results of this survey are presented. It is shown that minimum distance classification, using density estimators and Kullback-Leibler numbers as the distance measure, is equivalent to a form of maximum likelihood sample classification. It is also shown that for the parametric case, minimum distance classification is equivalent to nearest neighbor classification in the parameter space.

Wacker, A. G.; Landgrebe, D. A.

1971-01-01

255

Serum inhibitory titers and serum bactericidal titers for human subjects receiving multiple doses of the antibacterial oxazolidinones eperezolid and linezolid  

Microsoft Academic Search

In Phase I trials subjects received multiple doses of eperezolid (PNU-100592; formerly U-100592) and linezolid (PNU-100766; formerly U-100766), and steady-state samples were drawn at the projected peak and trough timepoints. Serum inhibitory titer and serum bactericidal titer values were determined using single strains of Staphylococcus aureus, Enterococcus faecalis, and Streptococcus pneumoniae. Serum inhibitory titer values generally correlated with drug concentration

Ronda D. Schaadt; Donald H. Batts; Peter T. Daley-Yates; Steven D. Pawsey; Dennis J. Stalker; Gary E. Zurenko

1997-01-01

256

Inhibitory activity of Phellodendri cortex extracts on differentiation of 3T3-L1 preadipocytes  

Microsoft Academic Search

The purpose of the present study was to investigate the inhibitory effect of beberine-rich fraction of Phellodendri cortex extract (PC) on adipogenesis in 3T3-L1 cells. PC effectively prevented TG accumulation in differentiation of 3T3-L1 preadipocytes\\u000a in a dose-dependent manner. Compared to controls, PC at a concentration of 75 ?g\\/mL significantly decreased lipid droplets\\u000a by 79.5%. Beberine exhibited similar inhibitory effect

Duk Kwon Choi; Tae Seok Oh; Jong Won Yun

2011-01-01

257

In vitro H+ -K+ ATPase inhibitory potential of methanolic extract of Cissus quadrangularis Linn.  

PubMed Central

Objective: This study was undertaken to study in vitro H+ -K+ ATPase inhibitory potential of methanolic extract of Cissus quadrangularis Linn. Materials and Mathods: Total phenolic and flavonoid contents from extract was quantified and H+ -K+ ATPase inhibition assay was performed in presence of different concentrations of standard (omeprazole) and methanol extract. Results: Extract showed significant (*P < 0.05) proton pump inhibitory activity in the goat gastric mucosal homogenate which was comparable to standard. Conclusions: These findings showed that methanolic extract of C. quadrangularis Linn. is potent inhibitor of proton pump.

Yadav, Priyanka; Ganeshpurkar, Aditya; Rai, Gopal

2012-01-01

258

34 CFR 303.433 - Minimum State complaint procedures.  

Code of Federal Regulations, 2013 CFR

...2013-07-01 false Minimum State complaint procedures. 303.433 Section 303.433 Education...Procedural Safeguards State Complaint Procedures § 303.433 Minimum State complaint procedures. (a) Time limit; minimum...

2013-07-01

259

34 CFR 300.152 - Minimum State complaint procedures.  

Code of Federal Regulations, 2013 CFR

...2013-07-01 false Minimum State complaint procedures. 300.152 Section 300.152 Education... State Eligibility State Complaint Procedures § 300.152 Minimum State complaint procedures. (a) Time limit; minimum...

2013-07-01

260

78 FR 54986 - Information Reporting of Minimum Essential Coverage  

Federal Register 2010, 2011, 2012, 2013

...Information Reporting of Minimum Essential Coverage AGENCY: Internal...guidance to providers of minimum essential health coverage that are subject...Chief Counsel (Income Tax and Accounting). However, other personnel...Information reporting for minimum essential coverage. (a)...

2013-09-09

261

12 CFR 1750.4 - Minimum capital requirement computation.  

Code of Federal Regulations, 2013 CFR

... CAPITAL Minimum Capital § 1750.4 Minimum capital requirement computation. (a) The minimum capital requirement for each...1) 2.50 percent times the aggregate on-balance...the current market value of posted...

2013-01-01

262

77 FR 71735 - Minimum Altitudes for Use of Autopilots  

Federal Register 2010, 2011, 2012, 2013

...lower minimum use altitudes based on their...lower minimum use altitudes might incur the cost of accelerated training. This accelerated...because this type of training would have occurred...setting new minimum altitudes for each...

2012-12-04

263

Alcohol and single-cell protein production by Kluyveromyces in concentrated whey permeates with reduced ash  

SciTech Connect

Five Kluyveromyces yeasts were grown in concentrated whey permeates under aerobic and anaerobic conditions to produce single-cell protein and ethanol. K. fragilis NRRL Y2415 produced the highest yield of alcohol, 9.1%, and K. bulgaricus ATCC 1605 gave the highest yield of biomass, 13.5 mg/mL. High ash, apparently through Na and K effects, inhibited production of biomass and alcohol. A 0.77% ash was optimum. Lactose utilization was more rapid under aerobic than anaerobic conditions. (NH/sub 4/)/sub 2/SO/sub 4/ and urea supplementation were without effect on yeast growth or were slightly inhibitory. A 1% peptone inclusion gave the highest biomass yield with minimum alcohol production.

Mahmoud, M.M.; Kosikowski, F.V.

1982-01-01

264

Anticipating Cycle 24 Minimum and Its Consequences.  

National Technical Information Service (NTIS)

On the basis of the 12-mo moving average of monthly mean sunspot number (R) through November 2006, cycle 23 has persisted for 126 mo, having had a minimum of 8.0 in May 1996, a peak of 120.8 in April 2000, and an ascent duration of 47 mo. In November 2006...

D. H. Hathaway R. M. Wilson

2007-01-01

265

Minimum Release of Tributyltin to Prevent Macrofouling.  

National Technical Information Service (NTIS)

The minimum release of tri-and dibutyltin has been determined for both barnacles and hydrozoans. The test method involved perfusing a known flux of biocide through a polycarbonate membrane filter with the downstream surface of the membrane exposed to a na...

E. G. Haslbeck G. I. Loeb J. W. Mihm

1990-01-01

266

Class of Minimum Bit Error Rate Algorithms  

Microsoft Academic Search

A class of adaptive beamforming algorithms was proposed based on directly minimizing the bit-error rate (BER). The popular linear minimum bit error rate (MBER) stochastic beamforming algorithms suffer from low convergence speed and large training data. In this paper, we investigate the use of adaptive stochastic gradient-Newton normalized MBER algorithms in the design of linear beamformer receivers for multipath Rayleigh

Tamer A. Samir; S. Elnoubi; A. Elnashar

2007-01-01

267

Minimum Loss Configuration of Power Distribution System  

Microsoft Academic Search

This paper presents a new method for minimum loss reconfiguration for radial power distribution system, in which the choice of the switches to be opened \\/ closed is based on the calculation of voltage at the buses, real and reactive power flowing through lines, real power losses and voltage deviation, using distribution load flow (DLF) program. In the process of

Jaswanti; T. Thakur

2006-01-01

268

Tight Results on Minimum Entropy Set Cover  

Microsoft Academic Search

In the minimum entropy set cover problem, one is given a collection of k sets which collectively cover an n-element ground set. A feasible solution of the problem is a partition of the ground set into parts such that each part is included in some of the k given sets. Such a partition defines a probability distribution, obtained by dividing

Jean Cardinal; Samuel Fiorini; Gwenaël Joret

2006-01-01

269

Computing steiner minimum trees in Hamming metric  

Microsoft Academic Search

Computing Steiner minimum trees in Hamming metric is a well studied problem that has applications in several fields of science such as computational linguistics and computational biology. Among all methods for finding such trees, algorithms using variations of a branch and bound method developed by Penny and Hendy have been the fastest for more than 20 years. In this paper

Ernst Althaus; Rouven Naujoks

2006-01-01

270

Minimum Bond Thickness Assembly Feature Assurance.  

National Technical Information Service (NTIS)

A minimum bond assurance feature for a pi-joint assembly is provided. The pi-joint assembly includes a substructure, a member coupled to the substructure. The substructure includes one or more standoff extending above one of the lower side, the front side...

J. J. Kilwin R. J. Newcomer

2004-01-01

271

Minimum Quality Standards, Fixed Costs, and Competition  

Microsoft Academic Search

I investigate the consequences of imposing a minimum quality standard on an industry in which firms face quality-dependent fixes costs and compete in quality and price. Even though the high-quality sellers would satisfy the standard in the absence of regulation, imposing a standard leads these sellers to raise qualities. They do so in an effort to alleviate the price competition,

Uri Ronnen

1991-01-01

272

Minimum cost trajectory planning for industrial robots  

Microsoft Academic Search

We discuss the problem of minimum cost trajectory planning for robotic manipulators. It consists of linking two points in the operational space while minimizing a cost function, taking into account dynamic equations of motion as well as bounds on joint positions, velocities, jerks and torques. This generic optimal control problem is transformed, via a clamped cubic spline model of joint

T. Chettibi; H. E. Lehtihet; M. Haddad; S. Hanchi

2004-01-01

273

Practical Parallel Algorithms for Minimum Spanning Trees  

Microsoft Academic Search

We study parallel algorithms for computing the minimum spanning tree of a weighted undirected graph G with n vertices and m edges. We consider an input graph G with m n p, where p is the number of processors. For this case, we show that simple algorithms with data- independent communication patterns are efficient, both in theory and in practice.

Frank K. H. A. Dehne; Silvia Götz

1998-01-01

274

Minimum Wages, Employment and Monopsonistic Competition.  

National Technical Information Service (NTIS)

We set out a model of monopsonistic competition, where each employer competes equally with every other employer. The employment effects of minimum wages depend on the degree of distortion in the labor market. If fixed costs per firm are high then the labo...

V. Bhasker T. To

2003-01-01

275

Computation of Minimum-Volume Covering Ellipsoids  

Microsoft Academic Search

We present a practical algorithm for computing the minimum volume n-dimensional ellipsoid that must contain m given points a1, . . . , am ? Rn. This convex con- strained problem arises in a variety of applied computational settings, particu- larly in data mining and robust statistics. Its structure makes it particularly amenable to solution by interior-point methods, and it

Peng Sun; Robert M. Freund

2004-01-01

276

Minimum-distance bounds by graph analysis  

Microsoft Academic Search

The parity-check matrix of a linear code is used to define a bipartite code constraint (Tanner) graph in which bit nodes are connected to parity check nodes. The connectivity properties of this graph are analyzed using both local connectivity and the eigenvalues of the associated adjacency matrix. A simple lower bound on minimum distance of the code is expressed in

Robert Michael Tanner

2001-01-01

277

Minimum Standards for Tribal Child Care Centers.  

ERIC Educational Resources Information Center

These minimum standards for tribal child care centers are being issued as guidance. An interim period of at least 1 year will allow tribal agencies to identify implementation issues, ensure that the standards reflect tribal needs, and guarantee that the standards provide adequate protection for children. The standards will be issued as regulations…

Administration on Children, Youth, and Families (DHHS), Washington, DC. Child Care Bureau.

278

Testing Beyond Minimums. Occasional Paper #5.  

ERIC Educational Resources Information Center

This paper considers three areas related to the testing of minimum knowledge and skills: public policy, the nature of higher-order thinking and selected aspects of educational measurement. The discussion of public policy issues centers around an apparent dichotomy of egalitarianism and elitism in public education, schooling and the public economy,…

Rudman, Herbert C.

1985-01-01

279

Efficient Approximation for Triangulation of Minimum Treewidth  

Microsoft Academic Search

We present four novel approximation algorithms for finding triangulation of minimum treewidth. Two of the algorithms improve on the running times of algorithms by Robertson and Seymour, and Becker and Geiger that approximate the op- timum by factors of4 and323 , respectively. A third algorithm is faster than those but gives an approximation factor of412 . The last algorithm is

Eyal Amir

2001-01-01

280

Statistical Inference of Minimum Rank Factor Analysis.  

ERIC Educational Resources Information Center

Developed a closed form expression for the asymptotic bias of the explained common variance, or the unexplained common variance under assumptions of multivariate normality in minimum rank factor analysis. Findings from existing data sets show that the presented asymptotic statistical inference is based on a recently developed perturbation theory…

Shapiro, Alexander; ten Berge, Jos M. F.

2002-01-01

281

Aurora borealis lag during the Maunder minimum  

Microsoft Academic Search

Observations of 121 occurrences of the aurora borealis recorded in Central Europe from 1645 to 1712 C.E. are compared with known phase relationships between auroral activity and sunspot cycles in modern times. A remarkable analogy of the aurora borealis cycles during the Maunder minimum is found, both with respect to phase-dependent frequency and to delayed maxima, with aurorae during the

Ludwig Schlamminger

1991-01-01

282

Unification of algorithms for minimum mode optimization  

NASA Astrophysics Data System (ADS)

Minimum mode following algorithms are widely used for saddle point searching in chemical and material systems. Common to these algorithms is a component to find the minimum curvature mode of the second derivative, or Hessian matrix. Several methods, including Lanczos, dimer, Rayleigh-Ritz minimization, shifted power iteration, and locally optimal block preconditioned conjugate gradient, have been proposed for this purpose. Each of these methods finds the lowest curvature mode iteratively without calculating the Hessian matrix, since the full matrix calculation is prohibitively expensive in the high dimensional spaces of interest. Here we unify these iterative methods in the same theoretical framework using the concept of the Krylov subspace. The Lanczos method finds the lowest eigenvalue in a Krylov subspace of increasing size, while the other methods search in a smaller subspace spanned by the set of previous search directions. We show that these smaller subspaces are contained within the Krylov space for which the Lanczos method explicitly finds the lowest curvature mode, and hence the theoretical efficiency of the minimum mode finding methods are bounded by the Lanczos method. Numerical tests demonstrate that the dimer method combined with second-order optimizers approaches but does not exceed the efficiency of the Lanczos method for minimum mode optimization.

Zeng, Yi; Xiao, Penghao; Henkelman, Graeme

2014-01-01

283

Minimum Entry Standards for Fire Prevention Officers.  

ERIC Educational Resources Information Center

This guide outlines the minimum standards for entrance into the fire prevention career field in California. It contains descriptions of 50 tasks. Each task description consists of nine subsections. The task title briefly identifies the content of the task. The occupational analysis subsection identifies the block, unit, and task within the…

San Jose Community Coll. District, CA.

284

Menu Plans: Maximum Nutrition for Minimum Cost.  

ERIC Educational Resources Information Center

Suggests that menu planning is the key to getting maximum nutrition in day care meals and snacks for minimum cost. Explores United States Department of Agriculture food pyramid guidelines for children and tips for planning menus and grocery shopping. Includes suggested meal patterns and portion sizes. (HTH)

Texas Child Care, 1995

1995-01-01

285

Inhibitory effect of carbon dioxide on bacterial cellulose production by Acetobacter in agitated culture  

Microsoft Academic Search

In order to study the inhibitory effect of the partial pressure of carbon dioxide (pCO2) on bacterial cellulose (BC) production by Acetobacter xylinum subsp. sucrofermentans BPR3001A, the BC concentration, oxygen consumption rate, viable cell concentration, and ATP content of the cells were investigated during cultivation in a 50-l jar fermentor sparged with air containing 10% (v\\/v) CO2. A high pCO2

Tohru Kouda; Takaaki Naritomi; Hisato Yano; Fumihiro Yoshinaga

1998-01-01

286

Insulin-dependent inhibition of hepatic glycogenolysis by gastric inhibitory polypeptide (GIP) in perfused rat liver  

Microsoft Academic Search

Summary  The effect of porcine gastric inhibitory polypeptide on hepatic glycogen metabolism was investigated in the isolated in situ perfused rat liver. Glycogenolysis was stimulated by infusion of glucagon into the portal vein (half maximal effective portal vein concentration 30 pmol\\/1). When glucagon was infused at a final portal vein concentration of 0.5 nmol\\/l, simultaneous addition of insulin inhibited the glucagon-dependent

H. Hartmann; R. Ebert; W. Creutzfeldt

1986-01-01

287

Inhibitory Effects of Methyl Jasmonate on the Germination and Ethylene Production in Cocklebur Seeds  

Microsoft Academic Search

.   Methyl jasmonate (JA-Me) inhibited the germination of cocklebur (Xanthium pennsylvanicum Wallr.) seeds. The inhibition of the germination of cocklebur seeds treated with JA-Me at concentrations less than 300 ?m was nullified by ethylene applied exogenously, although the inhibitory effect of 1,000 ?m JA-Me was not recovered completely even by high concentrations of ethylene (10,000 ?L\\/liter). JA-Me inhibited ethylene production

M. Nojavan-Asghari; K. Ishizawa

1998-01-01

288

Population dynamics of the dinoflagellate Prorocentrum minimum in Alexandria (Egypt) coastal waters  

Microsoft Academic Search

During an annual cycle, Prorocentrum minimum contributed three minor peaks, and two monospecies blooms in the Eastern Harbour of Alexandria (Egypt) following the intensive occurrence of Skeletonema costatum. The blooms occurred at 23.5–26.8 °C and salinity 35.5–37.2. The great variability of salinity, nutrient and oxidisable organic matter concentrations limit their contribution as regulating factors. P. minimum seems able to utilise organic

Samia K. Mikhail

2008-01-01

289

Inhibitory mechanism of red globe amaranth on tyrosinase.  

PubMed

Tyrosinase inhibitors from natural plants are currently attracting great interest. In this study, vanillic acid (VA) from red globe amaranth flower was identified as an effective tyrosinase inhibitor. The 50% inhibitory concentration values of VA were 0.53 and 0.63 mg/ml for the monophenolase and diphenolase activities of tyrosinase, respectively. VA did not function as a simple copper chelator, and it did not induce detectable changes in the enzyme conformation. An investigation into the interaction between VA and tyrosinase by docking method revealed that VA was bound to residues at the entrance to the dicopper center. This suggests that VA could strongly inhibit tyrosinase activity by hampering the binding of substrates to tyrosinase. Because of the stability of the complex, VA hindered binding of monophenol substrates better than that of diphenol substrates, which resulted in different inhibitory efficacies. A study of the mechanism of tyrosinase inhibition provided new evidence to elucidate the molecular mechanism of depigmentation by red globe amaranth plant. PMID:23578833

Mu, Yan; Li, Lin; Zhou, Yong; Wei, Hai-Liu; Hu, Song-Qing

2013-01-01

290

The ?-amylase and ?-glucosidase inhibitory effects of Irish seaweed extracts.  

PubMed

To date, numerous studies have reported on the antidiabetic properties of various plant extracts through inhibition of carbohydrate-hydrolysing enzymes. The objective of this research was to evaluate extracts of seaweeds for ?-amylase and ?-glucosidase inhibitory effects. Cold water and ethanol extracts of 15 seaweeds were initially screened and from this, five brown seaweed species were chosen. The cold water and ethanol extracts of Ascophyllum nodosum had the strongest ?-amylase inhibitory effect with IC50 values of 53.6 and 44.7 ?g/ml, respectively. Moreover, the extracts of Fucus vesiculosus Linnaeus were found to be potent inhibitors of ?-glucosidase with IC50 values of 0.32 and 0.49 ?g/ml. The observed effects were associated with the phenolic content and antioxidant activity of the extracts, and the concentrations used were below cytotoxic levels. Overall, our findings suggest that brown seaweed extracts may limit the release of simple sugars from the gut and thereby alleviate postprandial hyperglycaemia. PMID:23870944

Lordan, Sinéad; Smyth, Thomas J; Soler-Vila, Anna; Stanton, Catherine; Ross, R Paul

2013-12-01

291

Inhibitory Effects of Methylcellulose on Cellulose Degradation by Ruminococcus flavefaciens  

PubMed Central

Highly methylated, long-chain celluloses strongly inhibited cellulose degradation by several species of cellulolytic bacteria of ruminal origin. Specifically, the inhibitory effects of methylcellulose on the growth of Ruminococcus flavefaciens FD1 were concentration dependent, with complete inhibition at 0.1% (wt/vol). However, methylcellulose did not inhibit growth on cellobiose or cellulooligosaccharides. Mixtures of methylated cellulooligosaccharides having an average degree of polymerization of 6.7 to 9.5 inhibited cellulose degradation, but those with an average degree of polymerization of 1.0 to 4.5 did not. Similar inhibitory effects by methylcellulose and, to a lesser extent, by methyl cellulooligosaccharides were observed on cellulase activity, as measured by hydrolysis of p-nitrophenyl-?-d-cellobioside. R. flavefaciens cultures hydrolyzed cellulooligosaccharides to cellobiose and cellotriose as final end products. Cellopentaose and cellohexaose were cleaved to these end products, but cellotetraose was also formed from cellohexaose. Methylcellulose did not inhibit hydrolysis of cellulooligosaccharides. These data are consistent with the presence of separate cellulase (?-1,4-glucanase) and cellulodextrinase activities in R. flavefaciens.

Rasmussen, M. A.; Hespell, R. B.; White, B. A.; Bothast, R. J.

1988-01-01

292

In vitro ? -amylase and ?-glucosidase inhibitory potential of Trigonella foenum-graecum leaves extract.  

PubMed

Trigonella foenum-graecum is one of the widely used herbs in food and medicine. The seeds of the plants are investigated for antidiabetic potential; however, no efforts have been done to explore the potential of leaves to modify carbohydrate metabolizing enzymes viz. ?-amylase and ?-glucosidase. The present work was designed to investigate the inhibitory potential of ethyl acetate and water extract of T. foenum-graecum on enzymes ?-amylase and ?-glucosidase. Different concentrations of extracts were used to study inhibition of enzymatic activity of ?-amylase and ?-glucosidase. A dose dependent inhibitory effect on enzymes was observed. The current study, for the first time, revealed ?-amylase and ?-glucosidase inhibitory potential of T. foenum-graecum and the study could be helpful to isolate and characterize compounds responsible for it. PMID:24049415

Ganeshpurkar, Aditya; Diwedi, Varsha; Bhardwaj, Yash

2013-01-01

293

In vitro ? -amylase and ?-glucosidase inhibitory potential of Trigonella foenum-graecum leaves extract  

PubMed Central

Trigonella foenum-graecum is one of the widely used herbs in food and medicine. The seeds of the plants are investigated for antidiabetic potential; however, no efforts have been done to explore the potential of leaves to modify carbohydrate metabolizing enzymes viz. ?-amylase and ?-glucosidase. The present work was designed to investigate the inhibitory potential of ethyl acetate and water extract of T. foenum-graecum on enzymes ?-amylase and ?-glucosidase. Different concentrations of extracts were used to study inhibition of enzymatic activity of ?-amylase and ?-glucosidase. A dose dependent inhibitory effect on enzymes was observed. The current study, for the first time, revealed ?-amylase and ?-glucosidase inhibitory potential of T. foenum-graecum and the study could be helpful to isolate and characterize compounds responsible for it.

Ganeshpurkar, Aditya; Diwedi, Varsha; Bhardwaj, Yash

2013-01-01

294

Anticipating Cycle 24 Minimum and Its Consequences  

NASA Technical Reports Server (NTRS)

On the basis of the 12-mo moving average of monthly mean sunspot number (R) through November 2006, cycle 23 has persisted for 126 mo, having had a minimum of 8.0 in May 1996, a peak of 120.8 in April 2000, and an ascent duration of 47 mo. In November 2006, the 12-mo moving average of monthly mean sunspot number was 12.7, a value just outside the upper observed envelope of sunspot minimum values for the most recent cycles 16-23 (range 3.4-12.3), but within the 90-percent prediction interval (7.8 +/- 6.7). The first spotless day during the decline of cycle 23 occurred in January 2004, and the first occurrence of 10 or more and 20 or more spotless days was February 2006 and April 2007, respectively, inferring that sunspot minimum for cycle 24 is imminent. Through May 2007, 121 spotless days have accumulated. In terms of the weighted mean latitude (weighed by spot area) (LAT) and the highest observed latitude spot (HLS) in November 2006, 12-mo moving averages of these parameters measured 7.9 and 14.6 deg, respectively, these values being the lowest values yet observed during the decline of cycle 23 and being below corresponding mean values found for cycles 16-23. As yet, no high-latitude new-cycle spots have been seen nor has there been an upturn in LAT and HLS, these conditions having always preceded new cycle minimum by several months for past cycles. Together, these findings suggest that cycle 24 s minimum amplitude still lies well beyond November 2006. This implies that cycle 23 s period either will lie in the period "gap" (127-134 mo), a first for a sunspot cycle, or it will be longer than 134 mo, thus making cycle 23 a long-period cycle (like cycle 20) and indicating that cycle 24 s minimum will occur after July 2007. Should cycle 23 prove to be a cycle of longer period, a consequence might be that the maximum amplitude for cycle 24 may be smaller than previously predicted.

Wilson, Robert M.; Hathaway, David H.

2007-01-01

295

Anticipating Cycle 24 Minimum and Its Consequences  

NASA Astrophysics Data System (ADS)

On the basis of the 12-mo moving average of monthly mean sunspot number (R) through November 2006, cycle 23 has persisted for 126 mo, having had a minimum of 8.0 in May 1996, a peak of 120.8 in April 2000, and an ascent duration of 47 mo. In November 2006, the 12-mo moving average of monthly mean sunspot number was 12.7, a value just outside the upper observed envelope of sunspot minimum values for the most recent cycles 16-23 (range 3.4-12.3), but within the 90-percent prediction interval (7.8 +/- 6.7). The first spotless day during the decline of cycle 23 occurred in January 2004, and the first occurrence of 10 or more and 20 or more spotless days was February 2006 and April 2007, respectively, inferring that sunspot minimum for cycle 24 is imminent. Through May 2007, 121 spotless days have accumulated. In terms of the weighted mean latitude (weighed by spot area) (LAT) and the highest observed latitude spot (HLS) in November 2006, 12-mo moving averages of these parameters measured 7.9 and 14.6 deg, respectively, these values being the lowest values yet observed during the decline of cycle 23 and being below corresponding mean values found for cycles 16-23. As yet, no high-latitude new-cycle spots have been seen nor has there been an upturn in LAT and HLS, these conditions having always preceded new cycle minimum by several months for past cycles. Together, these findings suggest that cycle 24 s minimum amplitude still lies well beyond November 2006. This implies that cycle 23 s period either will lie in the period "gap" (127-134 mo), a first for a sunspot cycle, or it will be longer than 134 mo, thus making cycle 23 a long-period cycle (like cycle 20) and indicating that cycle 24 s minimum will occur after July 2007. Should cycle 23 prove to be a cycle of longer period, a consequence might be that the maximum amplitude for cycle 24 may be smaller than previously predicted.

Wilson, Robert M.; Hathaway, David H.

2007-11-01

296

Expression of leukemia inhibitory factor in craniopharyngioma  

Microsoft Academic Search

It has recently been reported that overexpression of leukemia inhibitory factor (LIF) in mice transgenic for LIF causes invagination\\u000a of the anterior wall of Rathke’s pouch leading to the formation of cysts lined by LIF immunoreactive epithelial cells. Strong\\u000a immunoreactivity was also found in human Rathke’s cleft cysts. Because such cysts and craniopharyngiomas share a common histogenesis,\\u000a we raised the

Ami Tran; Kalman Kovacs; Lucia Stefaneanu; George Kontogeorgos; Bernd W. Scheithauer; Shlomo Melmed

1999-01-01

297

Bacteriocin-like inhibitory activities among various species of Listeria  

Microsoft Academic Search

Three hundred Listeria isolates were examined for inhibitory activities using a deferred antagonism plating assay. Approximately 75% of the surveyed isolates produced inhibitory activity, the majority of which (71%) resulted from the production of bacteriophage or defective bacteriophage particles. Twenty-three isolates (8%) produced inhibitory activities distinct from those resulting from bacteriophage. Four of these isolates (Listeria innocua 743, L. innocua

M. L Kalmokoff; E Daley; J. W Austin; J. M Farber

1999-01-01

298

NK cell activation: distinct stimulatory pathways counterbalancing inhibitory signals  

Microsoft Academic Search

A delicate balance between positive and negative signals regulates NK cell effector function. Activation of NK cells may be initiated by the triggering of multiple adhesion or costimulatory molecules, and can be counterbalanced by inhibitory signals induced by receptors for MHC class I. A common pathway of inhibitory signaling is provided by immunoreceptor tyrosine-based inhibitory motifs (ITIMs) in the cytoplasmic

Alexander B. H Bakker; Jun Wu; Joseph H Phillips; Lewis L Lanier

2000-01-01

299

Inhibitory Control and Emotion Regulation in Preschool Children  

ERIC Educational Resources Information Center

This research investigated the relation between individual differences in inhibitory control and emotion regulation. Preschool children (N=53) ages 4-6 (M=5; 0) were assessed on brief batteries of inhibitory control of prepotent responses and emotion regulation. Individual differences in inhibitory control were significantly correlated with…

Carlson, Stephanie M.; Wang, Tiffany S.

2007-01-01

300

Effective concentration-based serum pharmacodynamics for antifungal azoles in a murine model of disseminated Candida albicans infection.  

PubMed

An assessment of the effective in vivo concentrations of antifungal drugs is important in determining their pharmacodynamics, and therefore, their optimal dosage regimen. Here we establish the effective in vivo concentration-based pharmacodynamics of three azole antifungal drugs (fluconazole, itraconazole, and ketoconazole) in a murine model of disseminated Candida albicans infection. A key feature of this study was the use of a measure of mycelial (m) growth rather than of yeast growth, and pooled mouse sera rather than synthetic media as a growth medium, for determining the minimum inhibitory concentrations (MICs) of azoles for C. albicans (denoted serum mMICs). The serum mMIC assay was then used to measure antifungal concentrations and effects as serum antifungal titers in the serum of treated mice. Both serum mMIC and sub-mMIC values reflected the effective in vivo serum concentrations. Supra-mMIC and mMIC effects exhibited equivalent efficacies and were concentration-independent, while the sub-mMIC effect was concentration-dependent. Following administration of the minimum drug dosage that inhibited an increase in mouse kidney fungal burden, the duration periods of these effects were similar for all drugs tested. The average duration of either the mMIC effect including the supra-mMIC effect, the sub-mMIC effect, or the post-antifungal effect (PAFE) were 6.9, 6.5 and 10.6 h, respectively. Our study suggests that the area under the curve for serum drug concentration versus time, between the serum mMIC and the sub-mMIC, and exposure time above the serum sub-mMIC after the mMIC effect, are major pharmacodynamic parameters. These findings have important implications for effective concentration-based pharmacodynamics of fungal infections treated with azoles. PMID:23539473

Maki, Katsuyuki; Kaneko, Shuji

2013-12-01

301

Spontaneous clustering via minimum gamma-divergence.  

PubMed

We propose a new method for clustering based on local minimization of the gamma-divergence, which we call spontaneous clustering. The greatest advantage of the proposed method is that it automatically detects the number of clusters that adequately reflect the data structure. In contrast, existing methods, such as K-means, fuzzy c-means, or model-based clustering need to prescribe the number of clusters. We detect all the local minimum points of the gamma-divergence, by which we define the cluster centers. A necessary and sufficient condition for the gamma-divergence to have local minimum points is also derived in a simple setting. Applications to simulated and real data are presented to compare the proposed method with existing ones. PMID:24206383

Notsu, Akifumi; Komori, Osamu; Eguchi, Shinto

2014-02-01

302

Minimum correlation in construction of multivariate distributions  

NASA Astrophysics Data System (ADS)

In this paper we present an algorithm for exact generation of multivariate samples with prespecified marginal distributions and a given correlation matrix, based on a mixture of Fréchet-Hoeffding bounds and marginal products. In the bivariate case, the algorithm can accommodate any among the theoretically possible correlation coefficients, and explicitly provides a connection between simulation and the minimum correlation attainable for different distribution families. We calculate the minimum correlations in several common distributional examples, including in some that have not been looked at before. As an illustration, we provide the details and results of implementing the algorithm for generating three-dimensional negatively and positively correlated Beta random variables, making it the only noncopula algorithm for correlated Beta simulation in dimensions greater than two. This work has potential for impact in a variety of fields where simulation of multivariate stochastic components is desired.

Dukic, Vanja M.; Mari?, Nevena

2013-03-01

303

Minimum spanning trees for community detection  

NASA Astrophysics Data System (ADS)

A simple deterministic algorithm for community detection is provided by using two rounds of minimum spanning trees. By comparing the first round minimum spanning tree (1st-MST) with the second round spanning tree (2nd-MST) of the network, communities are detected and their overlapping nodes are also identified. To generate the two MSTs, a distance matrix is defined and computed from the adjacent matrix of the network. Compared with the resistance matrix or the communicability matrix used in community detection in the literature, the proposed distance matrix is very simple in computation. The proposed algorithm is tested on real world social networks, graphs which are failed by the modularity maximization, and the LFR benchmark graphs for community detection.

Wu, Jianshe; Li, Xiaoxiao; Jiao, Licheng; Wang, Xiaohua; Sun, Bo

2013-05-01

304

Low Streamflow Forcasting using Minimum Relative Entropy  

NASA Astrophysics Data System (ADS)

Minimum relative entropy spectral analysis is derived in this study, and applied to forecast streamflow time series. Proposed method extends the autocorrelation in the manner that the relative entropy of underlying process is minimized so that time series data can be forecasted. Different prior estimation, such as uniform, exponential and Gaussian assumption, is taken to estimate the spectral density depending on the autocorrelation structure. Seasonal and nonseasonal low streamflow series obtained from Colorado River (Texas) under draught condition is successfully forecasted using proposed method. Minimum relative entropy determines spectral of low streamflow series with higher resolution than conventional method. Forecasted streamflow is compared to the prediction using Burg's maximum entropy spectral analysis (MESA) and Configurational entropy. The advantage and disadvantage of each method in forecasting low streamflow is discussed.

Cui, H.; Singh, V. P.

2013-12-01

305

Minimum wakefield achievable by waveguide damped cavity  

SciTech Connect

The authors use an equivalent circuit to model a waveguide damped cavity. Both exponentially damped and persistent (decay t{sup {minus}3/2}) components of the wakefield are derived from this model. The result shows that for a cavity with resonant frequency a fixed interval above waveguide cutoff, the persistent wakefield amplitude is inversely proportional to the external Q value of the damped mode. The competition of the two terms results in an optimal Q value, which gives a minimum wakefield as a function of the distance behind the source particle. The minimum wakefield increases when the resonant frequency approaches the waveguide cutoff. The results agree very well with computer simulation on a real cavity-waveguide system.

Lin, X.E.; Kroll, N.M.

1995-05-01

306

Human immunodeficiency virus type 1 inhibitory activity of Mentha longifolia.  

PubMed

Extracts from a new chemotype of Mentha longifolia, a mint species that grows spontaneously and widely in the Moroccan mountains, were tested against human immunodeficiency virus type 1 (HIV-1). We observed that non-toxic concentrations (10 microg/mL) of extracts from this plant, in particular methanol (Ext-1) and ethyl acetate (Ext-3) extracts, significantly inhibit (p < 0.01) HIV-1BaL infection by about 40% and 55%, respectively. In addition, only Ext-3 shows significant (p < 0.008) inhibitory activity (50% inhibition) against HIV-1 reverse transcriptase. It is noteworthy that chemical analysis of these extracts suggests that flavonoids, mainly flavones of M. longifolia, may be the major inhibitors of HIV infection. In conclusion, these in vitro data suggest that components of M. longifolia may represent potential anti-HIV agents; the identification of such components is in progress. PMID:15058498

Amzazi, Saaďd; Ghoulami, Saaďd; Bakri, Youssef; Il Idrissi, Abdelkader; Fkih-Tétouani, Souad; Benjouad, Abdelaziz

2003-01-01

307

Fidelity of complex spike mediated synaptic transmission between inhibitory interneurons  

PubMed Central

Complex spikes are high-frequency bursts of Na+ spikes, often riding on a slower Ca2+-dependent waveform. Although complex spikes may propagate into axons, given their unusual shape it is not clear how reliably these bursts reach nerve terminals, whether their spikes are efficiently transmitted as a cluster of postsynaptic responses, or what function is served by such a concentrated postsynaptic signal. We examined these questions by recording from synaptically coupled pairs of cartwheel cells, neurons which fire complex spikes and form an inhibitory network in the dorsal cochlear nucleus. Complex spikes in the presynaptic soma were reliably propagated to nerve terminals and elicited powerful, temporally precise postsynaptic responses. Single presynaptic neurons could prevent their postsynaptic partner from firing complex, but not simple, spikes, dramatically reducing dendritic Ca2+ signals in the postsynaptic neuron. We suggest that rapid transmission of complex spikes may control the susceptibility of neighboring neurons to Ca2+-dependent plasticity.

Roberts, Michael T.; Bender, Kevin J.; Trussell, Laurence O.

2008-01-01

308

Finding minimum area k-gons  

Microsoft Academic Search

Given a set P of n points in the plane and a number k, we want to flnd a polygonC with vertices in P of minimum area that satisfles one of the following properties: (1)C is a convex k-gon, (2)C is an empty convex k-gon, or (3) C is the convex hull of exactly k points of P. We give

M. H. Overmars; Gunter Rote; Gerhard Woeginger

1989-01-01

309

Tight Results on Minimum Entropy Set Cover  

Microsoft Academic Search

Abstract. In the minimum entropy set cover problem, one is given a collection of k sets which collectively cover an n-element ground,set. A feasible solution of the problem,is a partition of the ground set into parts such that each part is included in some of the k given sets. The goal is to find a partition minimizing the (binary) entropy

Jean Cardinal; Samuel Fiorini; Gwenaël Joret

2008-01-01

310

Minimum Description Length shape and appearance models.  

PubMed

The Minimum Description Length (MDL) approach to shape modelling is reviewed. It solves the point correspondence problem of selecting points on shapes defined as curves so that the points correspond across a data set. An efficient numerical implementation is presented and made available as open source Matlab code. The problems with the early MDL approaches are discussed. Finally the MDL approach is extended to an MDL Appearance Model, which is proposed as a means to perform unsupervised image segmentation. PMID:15344446

Thodberg, Hans Henrik

2003-07-01

311

Balancing minimum spanning and shortest path trees  

Microsoft Academic Search

This paper give a simple linear-time algorithm that, given a weighted\\u000adigraph, finds a spanning tree that simultaneously approximates a shortest-path\\u000atree and a minimum spanning tree. The algorithm provides a continuous\\u000atrade-off: given the two trees and epsilon > 0, the algorithm returns a\\u000aspanning tree in which the distance between any vertex and the root of the\\u000ashortest-path

Samir Khuller; Balaji Raghavacharit; Neal E. Young

1993-01-01

312

Externally Modulated Optical Minimum Shift Keying Format  

Microsoft Academic Search

This paper presents the generation and the performance evaluation of optical minimum shift keying (MSK) for high-speed and high-spectral-efficiency wavelength-division multiplexing systems. The detailed principle on optical MSK generation and detection is derived and analyzed. Optical MSK data (10.7 Gb\\/s) are successfully generated by an experiment using the proposed scheme. The results show that the optical MSK signal exhibits a

Jinyu Mo; Yang Jing Wen; Yixin Wang; Chao Lu; Wen-De Zhong

2007-01-01

313

Minimum-time running: a numerical approach.  

PubMed

The article deals with the minimum-time running problem. The time of covering a given distance is minimized. The Hill-Keller model of running employed is based on Newton's second law and the equation of power balance. The problem is formulated in optimal control. The unknown function is the runner's velocity that varies with the distance. The problem is solved applying the direct Chebyshev's pseudospectral method. PMID:21761812

Maro?ski, Ryszard; Rogowski, Krzysztof

2011-01-01

314

Proposed Minimum Reporting Standards for Chemical Analysis  

Microsoft Academic Search

Abstract,There is a general consensus that supports the need for standardized reporting of metadata or information describing large-scale metabolomics,and other functional genomics,data sets. Reporting of standard metadata,pro- vides a biological and empirical context for the data, facilitates experimental replication, and enables the re- interrogation and comparison,of data by others. Accord- ingly, the Metabolomics Standards Initiative is building a general,consensus,concerning,the minimum,reporting

Lloyd W. Sumner; Alexander Amberg; Dave Barrett; Richard Beger; Michael H. Beale; Clare Daykin; Teresa W.-M. Fan; Oliver Fiehn; Royston Goodacre; Julian L. Griffin; Thomas Hankemeier; Nigel Hardy; John C. Lindon; Philip Marriott; Andrew W. Nicholls; Michael D. Reily

315

Two variants of minimum discarded fill ordering  

SciTech Connect

It is well known that the ordering of the unknowns can have a significant effect on the convergence of Preconditioned Conjugate Gradient (PCG) methods. There has been considerable experimental work on the effects of ordering for regular finite difference problems. In many cases, good results have been obtained with preconditioners based on diagonal, spiral or natural row orderings. However, for finite element problems having unstructured grids or grids generated by a local refinement approach, it is difficult to define many of the orderings for more regular problems. A recently proposed Minimum Discarded Fill (MDF) ordering technique is effective in finding high quality Incomplete LU (ILU) preconditioners, especially for problems arising from unstructured finite element grids. Testing indicates this algorithm can identify a rather complicated physical structure in an anisotropic problem and orders the unknowns in the preferred'' direction. The MDF technique may be viewed as the numerical analogue of the minimum deficiency algorithm in sparse matrix technology. At any stage of the partial elimination, the MDF technique chooses the next pivot node so as to minimize the amount of discarded fill. In this work, two efficient variants of the MDF technique are explored to produce cost-effective high-order ILU preconditioners. The Threshold MDF orderings combine MDF ideas with drop tolerance techniques to identify the sparsity pattern in the ILU preconditioners. These techniques identify an ordering that encourages fast decay of the entries in the ILU factorization. The Minimum Update Matrix (MUM) ordering technique is a simplification of the MDF ordering and is closely related to the minimum degree algorithm. The MUM ordering is especially for large problems arising from Navier-Stokes problems. Some interesting pictures of the orderings are presented using a visualization tool. 22 refs., 4 figs., 7 tabs.

D'Azevedo, E.F. (Oak Ridge National Lab., TN (USA)); Forsyth, P.A.; Tang, Wei-Pai (Waterloo Univ., ON (Canada). Dept. of Computer Science)

1991-01-01

316

On the minimum creep rate of ?-cobalt  

Microsoft Academic Search

Flinn and Gilbert (1964) recently re-plotted the graphs of Feltham and Myers (1963), relating the logarithm of the minimum tensile creep rate, ?, of ?-cobalt and the inverse of the temperature for creep at 720–1020°K. They maintain that on extrapolating the re-plotted graphs in a certain manner below the range of strain rates used in the experiments, the occurrence of

T. A. Myers; P. Feltham

1964-01-01

317

An extended controllability problem with minimum energy  

Microsoft Academic Search

The aim of this paper is to consider an output controllability problem. It consists in driving the state of a distributed\\u000a parabolic system toward a state between two prescribed functions on a boundary subregion of the system evolution domain with\\u000a minimum energy control. Two necessary conditions are given. The first is formulated in terms of the subdifferential associated\\u000a with a

E. Zerrik; F. Ghafrani; M. Raďssouli

2009-01-01

318

Maintaining Minimum Spanning Trees in Dynamic Graphs  

Microsoft Academic Search

. We present the first fully dynamic algorithm for maintaininga minimum spanning tree in time o(pn) per operation. To be precise, thealgorithm uses O(n1=3log n) amortized time per update operation. Thealgorithm is fairly simple and deterministic. An immediate consequenceis the first fully dynamic deterministic algorithm for maintaining connectivityand, bipartiteness in amortized time O(n1=3log n) per update,with O(1) worst case time

Monika Rauch Henzinger; Valerie King

1997-01-01

319

Serum concentrations and pharmacokinetics of enrofloxacin after intravenous and intragastric administration to mares.  

PubMed Central

Serum concentrations and pharmacokinetics of enrofloxacin were studied in 6 mares after intravenous (IV) and intragastric (IG) administration at a single dose rate of 7.5 mg/kg body weight. In experiment 1, an injectable formulation of enrofloxacin (100 mg/mL) was given IV. At 5 min after injection, mean serum concentration was 9.04 microg/mL and decreased to 0.09 microg/mL by 24 h. Elimination half-life was 5.33 +/- 1.05 h and the area under the serum concentration vs time curve (AUC) was 21.03 +/- 5.19 mg x h/L. In experiment 2, the same injectable formulation was given IG. The mean peak serum concentration was 0.94 +/- 0.97 microg/mL at 4 h after administration and declined to 0.29 +/- 0.12 microg/mL by 24 h. Absorption of this enrofloxacin preparation after IG administration was highly variable, and for this reason, pharmacokinetic values for each mare could not be determined. In experiment 3, a poultry formulation (32.3 mg/mL) was given IG. The mean peak serum concentration was 1.85 +/- 1.47 microg/mL at 45 min after administration and declined to 0.19 +/- 0.06 microg/mL by 24 h. Elimination half-life was 10.62 +/- 5.33 h and AUC was 16.30 +/- 4.69 mg x h/L. Bioavailability was calculated at 78.29 +/- 16.55%. Minimum inhibitory concentrations of enrofloxacin were determined for equine bacterial culture specimens submitted to the microbiology laboratory over an 11-month period. The minimum inhibitory concentration of enrofloxacin required to inhibit 90% of isolates (MIC90) was 0.25 microg/mL for Staphylococcus aureus, Escherichia coli, Salmonella spp., Klebsiella spp., and Pasteurella spp. The poultry formulation was well tolerated and could be potentially useful in the treatment of susceptible bacterial infections in adult horses. The injectable enrofloxacin solution should not be used orally.

Haines, G R; Brown, M P; Gronwall, R R; Merritt, K A

2000-01-01

320

Effect of carbon dioxide concentration on the bioleaching of a pyrite-arsenopyrite ore concentrate  

SciTech Connect

The effect of carbon dioxide concentration on the bacterial leaching of a pyrite-arsenopyrite ore concentrate was studied in continuous-flow reactors. Steady-state operation with two feed slurry densities, 6 wt% and 16wt% solids, were tested for the effect of carbon dioxide concentration. Bacterial growth rates were estimated via the measurement of carbon dioxide consumption rates. Aqueous-phase carbon dioxide concentrations in excess of 10 mg/L were found to be inhibitory to bacterial growth.

Nagpal, S.; Dahlstrom, D. (Univ. of Utah, Salt Lake City (United States)); Oolman, T. (Radian Corp., Austin, TX (United States))

1993-02-20

321

Acetylcholinesterase and butyrylcholinesterase inhibitory activity of some Turkish medicinal plants.  

PubMed

The chloroform:medianol (1:1) extracts of a number of the plant species belonging to eight families, namely Corydalis solida (L.) Swartz subsp. solida and Glaucium corniculatum (L.) J. H. Rudolph (Papaveraceae), Rhododendron ponticum L. subsp. ponticum and Rhododendron luteum Sweet. (Ericaceae), Buxus sempervirens L. (Buxaceae), Vicia faba L. (Fabaceae), Robinia pseudoacacia L. (Caeselpiniaceae), Tribulus terrestris L. and Zygophyllum fabago L. (Zygophyllaceae), Lycopodium clavatum L. (Lycopodiaceae), Fumaria vaillantii Lois., Fumaria capreolata L., Fumaria kralikii Jordan, Fumaria asepala Boiss., Fumaria densiflora DC., Fumaria flabellata L., Fumaria petteri Reichb. subsp. thuretii (Boiss.) Pugsley, Fumaria macrocarpa Boiss. ex Hausskn., Fumaria cilicica Hauskkn., Fumaria parviflora Lam. and Fumaria judaica Boiss. (Fumariaceae) were screened for their anticholinesterase activity on acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) enzymes by in vitro Ellman method at 10 microg/ml and 1 mg/ml concentrations. The extracts did not show any noticeable inhibitory activity against both of the enzymes at 10 microg/ml. The extracts of Rhododendron ponticum subsp. ponticum, Rhododendron luteum, Corydalis solida subsp. solida, Glaucium corniculatum, and Buxus sempervirens showed remarkable inhibitory activity above 50% inhibition rate on AChE at 1 mg/ml. Among them, Rhododendron ponticum subsp. ponticum, Corydalis solida subsp. solida and Buxus sempervirens were the most active extracts against BChE having 95.46 +/- 1.03%, 93.08 +/- 0.97%, and 93.45 +/- 0.88% inhibition rates, respectively. Among the extracts screened, all of the Fumaria extracts displayed highly potent inhibition against both of the enzymes at 1 mg/ml concentration compared to the standard. PMID:15036468

Orhan, I; Sener, B; Choudhary, M I; Khalid, A

2004-03-01

322

Could a future "Grand Solar Minimum" like the Maunder Minimum stop global warming?  

NASA Astrophysics Data System (ADS)

A future Maunder Minimum type grand solar minimum, with total solar irradiance reduced by 0.25% over a 50 year period from 2020 to 2070, is imposed in a future climate change scenario experiment (RCP4.5) using, for the first time, a global coupled climate model that includes ozone chemistry and resolved stratospheric dynamics (Whole Atmosphere Community Climate Model). This model has been shown to simulate two amplifying mechanisms that produce regional signals of decadal climate variability comparable to observations, and thus is considered a credible tool to simulate the Sun's effects on Earth's climate. After the initial decrease of solar radiation in 2020, globally averaged surface air temperature cools relative to the reference simulation by up to several tenths of a degree Centigrade. By the end of the grand solar minimum in 2070, the warming nearly catches up to the reference simulation. Thus, a future grand solar minimum could slow down but not stop global warming.

Meehl, Gerald A.; Arblaster, Julie M.; Marsh, Daniel R.

2013-05-01

323

Prenatal stress and inhibitory neuron systems: implications for neuropsychiatric disorders.  

PubMed

Prenatal stress is a risk factor for several psychiatric disorders in which inhibitory neuron pathology is implicated. A growing body of research demonstrates that inhibitory circuitry in the brain is directly and persistently affected by prenatal stress. This review synthesizes research that explores how this early developmental risk factor impacts inhibitory neurons and how these findings intersect with research on risk factors and inhibitory neuron pathophysiology in schizophrenia, anxiety, autism and Tourette syndrome. The specific impact of prenatal stress on inhibitory neurons, particularly developmental mechanisms, may elucidate further the pathophysiology of these disorders. PMID:24751963

Fine, R; Zhang, J; Stevens, H E

2014-06-01

324

50 CFR 648.83 - Multispecies minimum fish sizes.  

Code of Federal Regulations, 2013 CFR

...2013-10-01 2013-10-01 false Multispecies minimum fish sizes. 648.83 Section 648.83 Wildlife...Monkfish Fisheries § 648.83 Multispecies minimum fish sizes. (a) Minimum fish sizes. (1) Minimum fish sizes for...

2013-10-01

325

Inhibitory activity of phosphates on molds isolated from foods and food processing plants.  

PubMed

Six commercial phosphates were evaluated for inhibition of the growth of 17 molds isolated from food sources. The assays were performed at neutral and natural (without pH adjustment) pH values, and the molds were streaked on plate count agar with added phosphates. Phosphate concentrations of 0.1, 0.3, 0.5, 1.0, and 1.5% (wt/vol) were used, and the MIC was determined. The resistance of molds to phosphates depended on the species. At a neutral pH, Aspergillus ochraceus and Fusarium proliferatum were resistant to all phosphates at all concentrations assayed, and Byssochlamys nivea, Aureobasidium pullulans, and Penicillium glabrum were most sensitive. The most inhibitory phosphates were those with chain lengths greater than 15 phosphate units and the highest sequestering power. At natural pH values (resulting from dissolving the phosphate in the medium), inhibitory activity changed dramatically for phosphates that produced alkaline or acidic pH in the medium. Phosphates with alkaline pH values (sodium tripolyphosphate of high solubility, sodium tripolyphosphate, and sodium neutral pyrophosphate) were much more inhibitory than phosphates at a neutral pH, but sodium acid pyrophosphate (acidic pH) had decreased inhibitory activity. The results indicate that some phosphates could be used in the food industry to inhibit molds linked to food spoilage. PMID:16300093

Suárez, V B; Frisón, L; de Basílico, M Z; Rivera, M; Reinheimer, J A

2005-11-01

326

Inhibitory effect of essential oils against herpes simplex virus type 2.  

PubMed

Essential oils from anise, hyssop, thyme, ginger, camomile and sandalwood were screened for their inhibitory effect against herpes simplex virus type 2 (HSV-2) in vitro on RC-37 cells using a plaque reduction assay. Genital herpes is a chronic, persistent infection spreading efficiently and silently as sexually transmitted disease through the population. Antiviral agents currently applied for the treatment of herpesvirus infections include acyclovir and its derivatives. The inhibitory concentrations (IC50) were determined at 0.016%, 0.0075%, 0.007%, 0.004%, 0.003% and 0.0015% for anise oil, hyssop oil, thyme oil, ginger oil, camomile oil and sandalwood oil, respectively. A clearly dose-dependent virucidal activity against HSV-2 could be demonstrated for all essential oils tested. In order to determine the mode of the inhibitory effect, essential oils were added at different stages during the viral infection cycle. At maximum noncytotoxic concentrations of the essential oils, plaque formation was significantly reduced by more than 90% when HSV-2 was preincubated with hyssop oil, thyme oil or ginger oil. However, no inhibitory effect could be observed when the essential oils were added to the cells prior to infection with HSV-2 or after the adsorption period. These results indicate that essential oils affected HSV-2 mainly before adsorption probably by interacting with the viral envelope. Camomile oil exhibited a high selectivity index and seems to be a promising candidate for topical therapeutic application as virucidal agents for treatment of herpes genitalis. PMID:17976968

Koch, C; Reichling, J; Schneele, J; Schnitzler, P

2008-01-01

327

Evaluation of Traditional Indian Antidiabetic Medicinal Plants for Human Pancreatic Amylase Inhibitory Effect In Vitro  

PubMed Central

Pancreatic ?-amylase inhibitors offer an effective strategy to lower the levels of post prandial hyperglycemia via control of starch breakdown. Eleven Ayurvedic Indian medicinal plants with known hypoglycemic properties were subjected to sequential solvent extraction and tested for ?-amylase inhibition, in order to assess and evaluate their inhibitory potential on pancreatic ?-amylase. Analysis of 91 extracts, showed that 10 exhibited strong Human Pancreatic Amylase (HPA) inhibitory potential. Of these, 6 extracts showed concentration dependent inhibition with IC50 values, namely, cold and hot water extracts from Ficus bengalensis bark (4.4 and 125??gmL?1), Syzygium cumini seeds (42.1 and 4.1??gmL?1), isopropanol extracts of Cinnamomum verum leaves (1.0??gmL?1) and Curcuma longa rhizome (0.16??gmL?1). The other 4 extracts exhibited concentration independent inhibition, namely, methanol extract of Bixa orellana leaves (49??gmL?1), isopropanol extract from Murraya koenigii leaves (127??gmL?1), acetone extracts from C. longa rhizome (7.4??gmL?1) and Tribulus terrestris seeds (511??gmL?1). Thus, the probable mechanism of action of the above fractions is due to their inhibitory action on HPA, thereby reducing the rate of starch hydrolysis leading to lowered glucose levels. Phytochemical analysis revealed the presence of alkaloids, proteins, tannins, cardiac glycosides, flavonoids, saponins and steroids as probable inhibitory compounds.

Ponnusamy, Sudha; Ravindran, Remya; Zinjarde, Smita; Bhargava, Shobha; Ravi Kumar, Ameeta

2011-01-01

328

Estimating in vivo airway surface liquid concentration in trials of inhaled antibiotics.  

PubMed

Antibiotic drugs exhibit concentration dependence in their efficacy. Therefore, ensuring appropriate concentration of these drugs in the relevant body fluid is important for obtaining the desired therapeutic and physiological action. Until recently there had been no suitable method available to measure or estimate concentration of drugs in the human airways resulting from inhaled aerosols or to determine the amount of inhaled antibiotics required to ensure minimum inhibitory concentration of a drug in the airway surface liquid (ASL). In this paper a numerical method is used for estimating local concentration of inhaled pharmaceutical aerosols in different generations of the human tracheobronchial airways. The method utilizes a mathematical lung deposition model to estimate amounts of aerosols depositing in different lung generations, and a recent ASL model along with deposition results to assess the concentration of deposited drugs immediately following inhalation. Examples of concentration estimates for two case studies: one for the antibiotic tobramycin against Pseudomonas aeruginosa, and another for taurolidine against Burkholderia cepacia are presented. The aerosol characteristics, breathing pattern and properties of nebulized solutions were adopted from two recent clinical studies on efficacy of these drugs in cystic fibrosis (CF) patients and from other sources in the literature. While the clinically effective tobramycin showed a concentration higher than the required in vivo concentration, that for the ineffective taurolidine was found to be below the speculated required in vivo concentration. Results of this study thus show that the mathematical ASL model combined with the lung deposition model can be an effective tool for helping decide the optimum dosage of inhaled antibiotic drugs delivered during human clinical trials. PMID:17894535

Hasan, M A; Lange, C F

2007-01-01

329

Portable mine dust concentration instrument  

Microsoft Academic Search

To improve health and safety conditions, there is need for a portable instrument that mine inspectors can use routinely for rapidly checking concentrations of dust in mine atmospheres. The objective of the study was to build, calibrate, and evaluate two prototype instruments. The emphasis was on certain minimum standards of size, weight, response time, sensitivity, ruggedness, reproducibility, permissibility, and cost

C. E. Lapple; C. F. Schadt

1972-01-01

330

Biodegradation of an inhibitory nongrowth substrate (nitroglycerin) in batch reactors  

SciTech Connect

Biodegradation of nitroglycerin (NG), an inhibitory, nongrowth substrate present in a multicomponent munition wastewater, was investigated in a pilot-scale batch reactor operated with both aerobic and anoxic cycles. A mixed culture was initially acclimated by gradual introduction of NG into influent and subsequently exposed to actual NG-laden production wastewater. System performance revealed that NG was amenable to aerobic biodegradation without adverse impact on removal efficiencies of other pollutants. Temporal NG concentration profiles indicated that an influent concentration of approximately 200 mg/L of NG was reduced to below detection limits in less than 5 h of aeration with no appreciable (<4%) biosorption. Failure of NG-acclimated cultures to utilize NG as a sole carbon source in bench-scale reactors suggested that NG behaved as a nongrowth substrate and its degradation possibly occurred by cometabolism. Ethyl acetate present in the waste stream was an adequate growth substrate in terms of both biological and physicochemical properties. High concentrations of NO[sub 3]-N, produced as a result of aerobic degradation of NG and other nitrogenous compounds of the waste, were treated in an anoxic phase. Approximately 95 mg/L of NO[sub 3]-N was denitrified to below detection limits in 5 h of anoxia without the addition of external carbon sources. Two SBR cycle schemes with different static-fill times exhibited significant differences in treatment efficiencies.

Pesari, H.; Grasso, D. (Univ. of Connecticut, Storrs (United States))

1993-01-05

331

Herpesvirus Exploitation of Host Immune Inhibitory Pathways  

PubMed Central

Herpesviruses employ a plethora of mechanisms to circumvent clearance by host immune responses. A key feature of mammalian immune systems is the employment of regulatory pathways that limit immune responsiveness. The primary functions of these mechanisms are to control autoimmunity and limit exuberant responses to harmless antigen in mucosal surfaces. However, such pathways can be exploited by viral pathogens to enable acute infection, persistence and dissemination. Herein, we outline the current understanding of inhibitory pathways in modulating antiviral immunity during herpesvirus infections in vivo and discuss strategies employed by herpesviruses to exploit these pathways to limit host antiviral immunity.

Stack, Gabrielle; Stacey, Maria A.; Humphreys, Ian R.

2012-01-01

332

Selective, state-dependent activation of somatostatin-expressing inhibitory interneurons in mouse neocortex.  

PubMed

The specific functions of subtypes of cortical inhibitory neurons are not well understood. This is due in part to a dearth of information about the behaviors of interneurons under conditions when the surrounding circuit is in an active state. We investigated the firing behavior of a subset of inhibitory interneurons, identified using mice that express green fluorescent protein (GFP) in a subset of somatostatin-expressing inhibitory cells ("GFP-expressing inhibitory neuron" [GIN] cells). The somata of the GIN cells were in layer 2/3 of somatosensory cortex and had dense, layer 1-projecting axons that are characteristic of Martinotti neurons. Interestingly, GIN cells fired similarly during a variety of diverse activating conditions: when bathed in fluids with low-divalent cation concentrations, when stimulated with brief trains of local synaptic inputs, when exposed to group I metabotropic glutamate receptor agonists, or when exposed to muscarinic cholinergic receptor agonists. During these manipulations, GIN cells fired rhythmically and persistently in the theta-frequency range (3-10 Hz). Synchronous firing was often observed and its strength was directly proportional to the magnitude of electrical coupling between GIN cells. These effects were cell type specific: the four manipulations that persistently activated GIN cells rarely caused spiking of regular-spiking (RS) pyramidal cells or fast-spiking (FS) inhibitory interneurons. Our results suggest that supragranular GIN interneurons form an electrically coupled network that exerts a coherent 3- to 10-Hz inhibitory influence on its targets. Because GIN cells are more readily activated than RS and FS cells, it is possible that they act as "first responders" when cortical excitatory activity increases. PMID:18799598

Fanselow, Erika E; Richardson, Kristen A; Connors, Barry W

2008-11-01

333

Minimum entropy restoration of star field images.  

NASA Astrophysics Data System (ADS)

The authors present an algorithm for restoration of star field images by incorporating both the minimum mean square error and the maximum varimax criteria. It is assumed that the point spread function of the distortion system can be well approximated by a Gaussian function. Simulated annealing is used to implement the optimization procedure. Simulation results for both Gaussian and square point spread functions with heavy additive independent white Gaussian noise are provided. Visual evaluation of the results indicate that the proposed algorithm performs better than the noncausal Wiener filtering method.

Wu, H.-S.; Barba, J.

1998-04-01

334

Aerobrake assembly with minimum Space Station accommodation  

NASA Technical Reports Server (NTRS)

The minimum Space Station Freedom accommodations required for initial assembly, repair, and refurbishment of the Lunar aerobrake were investigated. Baseline Space Station Freedom support services were assumed, as well as reasonable earth-to-orbit possibilities. A set of three aerobrake configurations representative of the major themes in aerobraking were developed. Structural assembly concepts, along with on-orbit assembly and refurbishment scenarios were created. The scenarios were exercised to identify required Space Station Freedom accommodations. Finally, important areas for follow-on study were also identified.

Katzberg, Steven J.; Butler, David H.; Doggett, William R.; Russell, James W.; Hurban, Theresa

1991-01-01

335

The minimum rate of dissipation principle  

NASA Astrophysics Data System (ADS)

We demonstrate that if the relaxation of a non-equilibrium system towards a steady-state satisfies the shortest path principle, then a covariant form of the Glansdorff Prigogine Universal Criterion of Evolution is also satisfied. We further prove that the Glansdorff Prigogine quantity is locally minimized when the evolution traces out a geodesic in the space of thermodynamic configurations. Physically the minimization of this term is the Minimum Rate of Dissipation Principle, which states that a thermodynamic system evolves towards a steady-state with the least possible dissipation and therefore relaxes along a geodesic.

Sonnino, Giorgio; Evslin, Jarah

2007-06-01

336

Inhibitory Effects of Pepstatin A and Mefloquine on the Growth of Babesia Parasites  

PubMed Central

We evaluated the inhibitory effects of pepstatin A and mefloquine on the in vitro and in vivo growths of Babesia parasites. The in vitro growth of Babesia bovis, B. bigemina, B. caballi, and B. equi was significantly inhibited (P < 0.05) by micromolar concentrations of pepstatin A (50% inhibitory concentrations = 38.5, 36.5, 17.6, and 18.1 ?M, respectively) and mefloquine (50% inhibitory concentrations = 59.7, 56.7, 20.7, and 4 ?M, respectively). Furthermore, both reagents either alone at a concentration of 5 mg/kg or in combinations (2.5/2.5 and 5/5 mg/kg) for 10 days significantly inhibited the in vivo growth of B. microti in mice. Mefloquine treatment was highly effective and the combination treatments were less effective than other treatments. Therefore, mefloquine may antagonize the actions of pepstatin A against babesiosis and aspartic proteases may play an important role in the asexual growth cycle of Babesia parasites.

Munkhjargal, Tserendorj; AbouLaila, Mahmoud; Terkawi, Mohamad Alaa; Sivakumar, Thillaiampalam; Ichikawa, Madoka; Davaasuren, Batdorj; Nyamjargal, Tserendorj; Yokoyama, Naoaki; Igarashi, Ikuo

2012-01-01

337

Minimum fan turbine inlet temperature mode evaluation  

NASA Technical Reports Server (NTRS)

Measured reductions in turbine temperature which resulted from the application of the F-15 performance seeking control (PSC) minimum fan turbine inlet temperature (FTIT) mode during the dual-engine test phase is presented as a function of net propulsive force and flight condition. Data were collected at altitudes of 30,000 and 45,000 feet at military and partial afterburning power settings. The FTIT reductions for the supersonic tests are less than at subsonic Mach numbers because of the increased modeling and control complexity. In addition, the propulsion system was designed to be optimized at the mid supersonic Mach number range. Subsonically at military power, FTIT reductions were above 70 R for either the left or right engines, and repeatable for the right engine. At partial afterburner and supersonic conditions, the level of FTIT reductions were at least 25 R and as much as 55 R. Considering that the turbine operates at or very near its temperature limit at these high power settings, these seemingly small temperature reductions may significantly lengthen the life of the turbine. In general, the minimum FTIT mode has performed well, demonstrating significant temperature reductions at military and partial afterburner power. Decreases of over 100 R at cruise flight conditions were identified. Temperature reductions of this magnitude could significantly extend turbine life and reduce replacement costs.

Orme, John S.; Nobbs, Steven G.

1995-01-01

338

Minimum cost model energy code envelope requirements  

SciTech Connect

This paper describes the analysis underlying development of the U.S. Department of Energy`s proposed revisions of the Council of American Building Officials (CABO) 1993 Model Energy Code (MEC) building thermal envelope requirements for single-family and low-rise multifamily residences. This analysis resulted in revised MEC envelope conservation levels based on an objective methodology that determined the minimum-cost combination of energy efficiency measures (EEMs) for residences in different locations around the United States. The proposed MEC revision resulted from a cost-benefit analysis from the consumer`s perspective. In this analysis, the costs of the EEMs were balanced against the benefit of energy savings. Detailed construction, financial, economic, and fuel cost data were compiled, described in a technical support document, and incorporated in the analysis. A cost minimization analysis was used to compare the present value of the total long-nm costs for several alternative EEMs and to select the EEMs that achieved the lowest cost for each location studied. This cost minimization was performed for 881 cities in the United States, and the results were put into the format used by the MEC. This paper describes the methodology for determining minimum-cost energy efficiency measures for ceilings, walls, windows, and floors and presents the results in the form of proposed revisions to the MEC. The proposed MEC revisions would, on average, increase the stringency of the MEC by about 10%.

Connor, C.C.; Lucas, R.G.; Turchen, S.J.

1994-08-01

339

Lipoxygenase inhibitory activity of alkyl protocatechuates.  

PubMed

Alkyl 3,4-dihydroxybenzoates (protocatechuates) inhibited linoleic acid peroxidation catalyzed by soybean lipoxygenase-1 (EC 1.13.11.12, Type 1). Their inhibitory activities displayed a parabolic function of their lipophilicity and maximized with alkyl chain lengths of between C11 and C14. Tetradecanyl protocatechuate exhibited the most potent inhibition with an IC50 of 0.05 ?M, followed by dodecyl (lauryl) protocatechuate with an IC50 of 0.06 ?M. However, their parent compound, protocatechuic acid, did not show this inhibitory activity up to 200 ?M, indicating that the alkyl chain length is significantly related to the inhibition activity. The allosteric (or cooperative) inhibition of soybean lipoxygenase-1 of longer alkyl protocatechuates is reversible but in combination with their iron binding ability to disrupt the active site competitively and to interact with the hydrophobic portion surrounding near the active site (sequential action). In the case of dodecyl protocatechuate, the enzyme quickly binds this protocatechuate and then its dodecyl group undergoes a slow interaction with the hydrophobic domain in close proximity to the active site in the enzyme. The inhibition kinetics analyzed by Lineweaver-Burk plots indicates that octyl protocatechuate is a competitive inhibitor and the inhibition constant (Ki) was obtained as 0.23 ?M but dodecyl protocatechuate is a slow binding inhibitor. PMID:24767084

Ha, Tae Joung; Shimizu, Kuniyoshi; Kubo, Isao

2014-09-15

340

Maximizing exposure therapy: An inhibitory learning approach.  

PubMed

Exposure therapy is an effective approach for treating anxiety disorders, although a substantial number of individuals fail to benefit or experience a return of fear after treatment. Research suggests that anxious individuals show deficits in the mechanisms believed to underlie exposure therapy, such as inhibitory learning. Targeting these processes may help improve the efficacy of exposure-based procedures. Although evidence supports an inhibitory learning model of extinction, there has been little discussion of how to implement this model in clinical practice. The primary aim of this paper is to provide examples to clinicians for how to apply this model to optimize exposure therapy with anxious clients, in ways that distinguish it from a 'fear habituation' approach and 'belief disconfirmation' approach within standard cognitive-behavior therapy. Exposure optimization strategies include 1) expectancy violation, 2) deepened extinction, 3) occasional reinforced extinction, 4) removal of safety signals, 5) variability, 6) retrieval cues, 7) multiple contexts, and 8) affect labeling. Case studies illustrate methods of applying these techniques with a variety of anxiety disorders, including obsessive-compulsive disorder, posttraumatic stress disorder, social phobia, specific phobia, and panic disorder. PMID:24864005

Craske, Michelle G; Treanor, Michael; Conway, Christopher C; Zbozinek, Tomislav; Vervliet, Bram

2014-07-01

341

New Cholinesterase Inhibitory Constituents from Lonicera quinquelocularis  

PubMed Central

A phytochemical investigation on the ethyl acetate soluble fraction of Lonicera quinquelocularis (whole plant) led to the first time isolation of one new phthalate; bis(7-acetoxy-2-ethyl-5-methylheptyl) phthalate (3) and two new benzoates; neopentyl-4-ethoxy-3, 5-bis (3-methyl-2-butenyl benzoate (4) and neopentyl-4-hydroxy-3, 5-bis (3-methyl-2-butenyl benzoate (5) along with two known compounds bis (2-ethylhexyl phthalate (1) and dioctyl phthalate (2). Their structures were established on the basis of spectroscopic analysis and by comparison with available data in the literature. All the compounds (1–5) were tested for their acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) inhibitory activities in dose dependent manner. The IC50 (50% inhibitory effect) values of compounds 3 and 5 against AChE were 1.65 and 3.43 µM while the values obtained against BChE were 5.98 and 9.84 µM respectively. Compounds 2 and 4 showed weak inhibition profile.

Khan, Dilfaraz; Khan, Hidayat Ullah; Khan, Farmanullah; Khan, Shafiullah; Badshah, Syed; Khan, Abdul Samad; Samad, Abdul; Ali, Farman; Khan, Ihsanullah; Muhammad, Nawshad

2014-01-01

342

Bilingualism influences inhibitory control in auditory comprehension  

PubMed Central

Bilinguals have been shown to outperform monolinguals at suppressing task-irrelevant information. The present study aimed to identify how processing linguistic ambiguity during auditory comprehension may be associated with inhibitory control. Monolinguals and bilinguals listened to words in their native language (English) and identified them among four pictures while their eye-movements were tracked. Each target picture (e.g., hamper) appeared together with a similar-sounding within-language competitor picture (e.g., hammer) and two neutral pictures. Following each eye-tracking trial, priming probe trials indexed residual activation of target words, and residual inhibition of competitor words. Eye-tracking showed similar within-language competition across groups; priming showed stronger competitor inhibition in monolinguals than in bilinguals, suggesting differences in how inhibitory control was used to resolve within-language competition. Notably, correlation analyses revealed that inhibition performance on a nonlinguistic Stroop task was related to linguistic competition resolution in bilinguals but not in monolinguals. Together, monolingual-bilingual comparisons suggest that cognitive control mechanisms can be shaped by linguistic experience.

Blumenfeld, Henrike K.; Marian, Viorica

2013-01-01

343

Excitatory and inhibitory mechanisms underlying somatosensory habituation.  

PubMed

Habituation is a basic process of learning in which repeated exposure to a sensory stimulus leads to a decrease in the strength of neuronal activations and behavioral responses. In addition to increases in neuronal activity, sensory stimuli can also lead to decreases in neuronal activity. Until now, the effects of habituation on stimulus-induced neuronal deactivations have not been investigated. We performed functional magnetic resonance imaging in 30 healthy subjects during repetitive unilateral somatosensory stimulation and combined this analysis with a psychophysiological examination of changes in the perception threshold. Consistent with the literature, we found a time-dependent decrease of the positive blood oxygenation level-dependent (BOLD) response (indicative of habituation) in the primary somatosensory cortex (SI) contralateral to the stimulus. In contrast, the negative BOLD response (NBR) in the ipsilateral SI did not show a decrease in amplitude; instead, an increase in amplitude was found, i.e., a stronger NBR (increased response). The increased NBR was associated with an increased perception threshold of the nonstimulated hand. These findings suggest that habituation is not primarily characterized by a decrease in the neuronal response to repeated stimuli but rather a widespread change in the balance between excitatory and inhibitory effects that favors inhibitory effects. PMID:22847930

Klingner, Carsten M; Hasler, Caroline; Brodoehl, Stefan; Witte, Otto W

2014-01-01

344

Evaluation of 147 Kampo prescriptions as novel protein tyrosine phosphatase 1B (PTP1B) inhibitory agents  

PubMed Central

Background Protein tyrosine phosphatase (PTP) 1B, a negative regulator of the insulin and leptin signaling pathways, is currently considered a promising target for the development of novel therapeutic approaches used to treat insulin-resistant type 2 diabetes mellitus (IR-T2DM). In this study, we examined the PTP1B inhibitory activity of 147 Japanese prescription Kampo formulations to evaluate their potential for clinical application in IR-T2DM treatment. Methods We specifically defined the prescribed daily dose as 1 Unit (U), and 147 Japanese prescription Kampo formulations were screened for PTP1B inhibitory activity at a final concentration of 0.1 mU/mL. We investigated the dependence of the inhibitory activity on the concentration of the Kampo formulations that exhibited high PTP1B inhibitory activity. Their inhibition mode by kinetic analysis, inhibitory selectivities against four homologous PTPs (TCPTP, VHR, SHP-1 and SHP-2) and cellular activity in the insulin-signaling pathway by increasing the insulin-stimulated Akt phosphorylation level in human hepatocellular liver carcinoma HepG2 cells, were also investigated. The statistical partial least squares regression method was used to identify the crude drugs with the greatest contribution to the PTP1B inhibitory activity of the Kampo formulations. Results Daiokanzoto, Masiningan, Tokakujokito, Keimakakuhanto and Choijokito exhibited high PTP1B inhibitory activity, which was concentration-dependent. Daiokanzoto, Masiningan and Tokakujokito inhibited PTP1B by mixed inhibition modes and exhibited different inhibitory selectivities against four homologous PTPs. Masiningan also exhibited cellular activity. Statistical analyses indicated that the constituent crude drug Rhei Rhizoma provided the greatest contribution to the PTP1B inhibitory activity of these Kampo formulations. Conclusions High PTP1B inhibitory activity was predominantly associated with formulations that were classified as Jyokito in Kampo medicine and with a modern clinical indication of constipation. Currently, there is no clinical treatment for IR-T2DM that uses a mechanism of action based on PTP1B inhibition. Thus, we propose the Kampo formulations identified in this study as strong PTP1B inhibitors, which could be developed as clinical therapeutic agents to treat IR-T2DM.

2014-01-01

345

Compounds from Gum Ammoniacum with Acetylcholinesterase Inhibitory Activity  

PubMed Central

The use of herbal medicinal preparations in dementia therapy has been studied based on experience from traditional medicine. A dichloromethane extract of gum ammoniacum, the gum-resin from Dorema ammoniacum D. Don had shown acetylcholinesterase (AChE) inhibitory activity in a previous study. The aim of this study was the isolation and characterization of the active compounds from this resin. The extract was investigated by a respective colorimetric microplate assay and the active zones were identified via TLC bioautography and isolated using several chromatographic techniques. The structures of the active components were characterized by one- and two-dimensional 1H and 13C NMR spectroscopy and mass spectrometry as (2?S,5?S)-2?-ethenyl-5?-(3-hy-droxy-6-methyl-4-oxohept-5-en-2-yl)-7-methoxy-2?-methyl-4H-spiro[chromene-3,1?-cyclopentane]-2,4-dione (1), which is an analogue of doremone A and a new natural compound, and as (2?S,5?R)-2?-ethenyl-5?-[(2R,4R)-4-hydroxy-6-methyl-3-oxohept-5-en-2-yl]-7-methoxy-2?-methyl-4H-spiro[chromene-3,1?-cyclo-pentane]-2,4-dione (2 = doremone A), (4E,8E)-1-(2,4-dihydroxyphenyl)-5,9,13-trimethyltetradeca-4,8,12-trien-1-one (3 = dshamirone), and 4,7-dihydroxy-3-[(2E,6E)-3,7,11-trimethyldodeca-2,6,10-trien-1-yl]-2H-chromen-2-one (4 = am-moresinol). Dshamirone turned out to be the most active compound with an IC50 value for AChE inhibitory activity of 23.5 ?M, whereas the other substances showed weak activity. The concentrations of the analytes in the resin were determined by HPLC as 3.1%, 4.6%, 1.9%, and 9.9%, respectively.

Adhami, Hamid-Reza; Lutz, Johannes; Kahlig, Hanspeter; Zehl, Martin; Krenn, Liselotte

2013-01-01

346

Hypoxia Limits Inhibitory Effects of Zn2+ on Spreading Depolarizations  

PubMed Central

Spreading depolarizations (SDs) are coordinated depolarizations of brain tissue that have been well-characterized in animal models and more recently implicated in the progression of stroke injury. We previously showed that extracellular Zn2+ accumulation can inhibit the propagation of SD events. In that prior work, Zn2+ was tested in normoxic conditions, where SD was generated by localized KCl pulses in oxygenated tissue. The current study examined the extent to which Zn2+ effects are modified by hypoxia, to assess potential implications for stroke studies. The present studies examined SD generated in brain slices acutely prepared from mice, and recordings were made from the hippocampal CA1 region. SDs were generated by either local potassium injection (K-SD), exposure to the Na+/K+-ATPase inhibitor ouabain (ouabain-SD) or superfusion with modified ACSF with reduced oxygen and glucose concentrations (oxygen glucose deprivation: OGD-SD). Extracellular Zn2+ exposures (100 µM ZnCl2) effectively decreased SD propagation rates and significantly increased the initiation threshold for K-SD generated in oxygenated ACSF (95% O2). In contrast, ZnCl2 did not inhibit propagation of OGD-SD or ouabain-SD generated in hypoxic conditions. Zn2+ sensitivity in 0% O2 was restored by exposure to the protein oxidizer DTNB, suggesting that redox modulation may contribute to resistance to Zn2+ in hypoxic conditions. DTNB pretreatment also significantly potentiated the inhibitory effects of competitive (D-AP5) or allosteric (Ro25-6981) NMDA receptor antagonists on OGD-SD. Finally, Zn2+ inhibition of isolated NMDAR currents was potentiated by DTNB. Together, these results suggest that hypoxia-induced redox modulation can influence the sensitivity of SD to Zn2+ as well as to other NMDAR antagonists. Such a mechanism may limit inhibitory effects of endogenous Zn2+ accumulation in hypoxic regions close to ischemic infarcts.

Aiba, Isamu; Shuttleworth, C. William

2013-01-01

347

The inhibitory effect of gallamine on muscarinic receptors.  

PubMed Central

1 The inhibitory effect of gallamine (1.1 muM-1.1 mM) on negative inotropic responses to acetylcholine (ACh) or carbachol (CCh) was investigated in isolated electrically stimulated atria of the guinea-pig. Gallamine caused parallel rightward shifts of the dose-response curves to the agonists, with no depression of the maximal response. 2 Gallamine (0.11 - 1.1 mM) produced a greater degree of antagnism towards CCh than towards ACh. With either agonist, the degree of antagonism produced by gallamine in high concentrations was less than that expected for a competitive antagonist.. 3 Similar findings were made when either negative inotropic or chronotropic responses were recorded in spontaneously beating guinea-pig atria. The inhibitory effect of gallamine against the negative inotropic response to cholinomimetics in electrically stimulated atria was not altered either in the presence of propranol (17 muM) or in atria obtained from guinea-pigs pretreated with diisopropylphosphorofluoridate (DEP) 12.5 mumol/kg, in divided doses over 3 days). 4 When ACh was used as the agonist, combination of gallamine with atropine (0.05-0.4 muM) produced dose-ratios which were less than expected for combination of two competitive antagonists. The same phenomenon was observed in atria obtained from guinea-pigs pretreated with DFP. 5 It is suggested that the antagonism produced by gallamine is a type of non-competitive inhibition, which has been termed "metaffinoid antagonism". An antagonist of this type allosterically alters the affinity of the agonist for its binding site, rather than changing the effectiveness of the agonist-receptor interaction.

Clark, A L; Mitchelson, F

1976-01-01

348

Intracellular chloride ions regulate the time-course of GABA-mediated inhibitory synaptic transmission  

PubMed Central

The time-dependent integration of excitatory and inhibitory synaptic currents is an important process for shaping the input-output profiles of individual excitable cells, and therefore the activity of neuronal networks. Here, we show that the decay time-course of GABAergic inhibitory synaptic currents is considerably faster when recorded with physiological internal Cl? concentrations than with symmetrical Cl? solutions. This effect of intracellular Cl? is due to a direct modulation of the GABAA receptor that is independent of the net direction of current flow through the ion channel. As a consequence, the time window during which GABAergic inhibition can counteract coincident excitatory inputs is much shorter, under physiological conditions, compared to that previously measured using high internal Cl?. This is expected to have implications for neuronal network excitability and neurodevelopment, and for our understanding of pathological conditions, such as epilepsy and chronic pain, where intracellular Cl? concentrations can be altered.

Houston, Catriona M.; Bright, Damian P.; Sivilotti, Lucia G; Beato, Marco; Smart, Trevor G.

2009-01-01

349

Angiotensin converting enzyme inhibitory activity of amino acid esters of carbohydrates  

Microsoft Academic Search

l-Alanyl-d-glucose, l-valyl-d-glucose, l-phenylalanyl-d-glucose and l-phenylalanyl-lactose esters were synthesized enzymatically using two lipases viz., Rhizomucor miehei lipase (RML) and porcine pancreas lipase (PPL) and tested for their potential as inhibitors of angiotensin converting enzyme (ACE) in vitro. The esters exhibited concentration related ACE inhibitory activity. The potency of the various esters measured in terms of IC50 values were as follows: l-phenylalanyl-d-glucose,

Vasudeva Kamath; P. S. Rajini; K. Lohith; B. R. Somashekar; S. Divakar

2006-01-01

350

Excitatory and inhibitory 5-hydroxytryptamine (5HT) receptors expressed in the isolated porcine uterine muscles  

Microsoft Academic Search

5-Hydroxytryptamine (5-HT) receptors mediating excitatory and inhibitory actions of 5-HT on contractility of uterine strips from non-pregnant pigs were characterized. Expression of 5-HT2A and 5-HT7 receptors was examined by molecular biological study. 5-HT-containing cells were observed immunohistochemically. In the spontaneously contracting uterine circular muscle layers, 5-HT caused inhibition of contractile activity. SB269970 (5-HT7 receptor antagonist, 10 nM) shifted the concentration-inhibition curve

Tatsuro Nakamura; Takio Kitazawa; Jinshan Cao; Takuya Iwamoto; Hiroki Teraoka; Koichi Kadota; Tetsuro Taneike

2008-01-01

351

Inhibitory activity of Thai condiments on pandemic strain of Vibrio parahaemolyticus  

Microsoft Academic Search

Antibacterial activity of 13 condiments used in Thai cooking was investigated with a pandemic strain of Vibrio parahaemolyticus. Using a disk diffusion technique, freshly squeezed extracts from galangal, garlic and lemon, at a concentration of 10?l\\/disk produced a clear zone of 13.6±0.5, 11.6±0.5 and 8.6±1.2mm, respectively. The inhibitory activity of these 3 condiments on pandemic strains was not significantly different

Varaporn Vuddhakul; Phuangthip Bhoopong; Fadeeya Hayeebilan; Sanan Subhadhirasakul

2007-01-01

352

In vitro inhibitory effect of cranberry ( Vaccinium macrocarpum Ait.) juice on pathogenic microorganisms  

Microsoft Academic Search

The purpose of this study was to determine the inhibitory effects of cranberry juice on pathogenic microorganisms. The microorganisms\\u000a analyzed were Escherichia coli from patients with urinary infections, Salmonella spp., Listeria monocytogenes, Pseudomona aeruginosa, and Staphylococcus aureus. The disc method was used to determine the sensitivity of bacteria to cranberry juice (CJ, both concentrated and diluted).\\u000a A lawn of 106

H. L. E. Magarińos; C. Sahr; S. D. C. Selaive; M. E. Costa; F. E. Figuerola; O. A. Pizarro

2008-01-01

353

Minimum qualifications for clinical pharmacy practice faculty.  

PubMed

The American College of Clinical Pharmacy 2013 Educational Affairs Committee was charged with developing recommendations for the minimum qualifications required for clinical pharmacy practice faculty in United States colleges and schools of pharmacy with respect to education, postgraduate training, board certification, and other experiences. From a review of the literature, the committee recommends that clinical pharmacy practice faculty possess the following minimum qualifications, noting that, for some positions, additional qualifications may be necessary. Clinical pharmacy practice faculty should possess the Doctor of Pharmacy degree from an Accreditation Council for Pharmacy Education–accredited institution. In addition, faculty should have completed a postgraduate year one (PGY1) residency or possess at least 3 years of direct patient care experience. Faculty who practice in identified areas of pharmacotherapy specialization, as identified by American Society of Health-System Pharmacists postgraduate year two (PGY2) residency guidelines, should have completed a PGY2 residency in that area of specialty practice. Alternatively, faculty should have completed a minimum of a PGY1 residency and 1 additional year of practice, with at least 50% of time spent in their area of specialization, which is documented in a portfolio, or 4 years of direct patient care in their area of specialization, which is documented in a portfolio. Fellowship training or a graduate degree (e.g., Ph.D.) should be required for research-intensive clinical faculty positions. All faculty should obtain structured teaching experience during or after postgraduate training, preferably through a formal teaching certificate program or through activities documented in a teaching portfolio. A baseline record of scholarship should be obtained before hire as clinical pharmacy practice faculty through exposure in postgraduate programs or previous employment. Faculty should be board certified before hire or attain board certification within 2 years of hire through the Board of Pharmacy Specialties (BPS) or, if appropriate for the practice area, through a nonBPS-certifying agency. If no certification exists in the area of specialty, the faculty member should develop a portfolio with evidence of excellence in clinical practice, teaching, and scholarship. PMID:24877188

Engle, Janet P; Erstad, Brian L; Anderson, Douglas C; Bucklin, Mason H; Chan, Alexandre; Donaldson, Amy R; Hagemann, Tracy M; O'Connell, Mary Beth; Rodgers, Philip T; Tennant, Sarah; Thomas, Zachariah

2014-05-01

354

Origin and Evolution of Coronal Streamer Structure during the 1996 Minimum Activity Phase  

Microsoft Academic Search

We employ coronal extrapolations of solar magnetograph data to interpret observations of the white-light streamer structure made with the LASCO coronagraph in 1996. The topological appearance of the streamer belt during the present minimum activity phase is well described by a model in which the Thomson-scattering electrons are concentrated around a single, warped current sheet encircling the Sun. Projection effects

N. R. Sheeley Jr.; R. A. Howard; J. R. Kraemer; N. B. Rich; M. D. Andrews; G. E. Brueckner; K. P. Dere; M. J. Koomen; C. M. Korendyke; D. J. Michels; J. D. Moses; S. E. Paswaters; D. G. Socker; D. Wang; P. L. Lamy; A. Llebaria; D. Vibert; R. Schwenn; G. M. Simnett

1997-01-01

355

Macrophage migration inhibitory factor deficiency in chronic obstructive pulmonary disease.  

PubMed

The pathogenesis of chronic obstructive pulmonary disease (COPD) remains poorly understood. Cellular senescence and apoptosis contribute to the development of COPD; however, crucial regulators of these underlying mechanisms remain unknown. Macrophage migration inhibitory factor (MIF) is a pleiotropic cytokine that antagonizes both apoptosis and premature senescence and may be important in the pathogenesis of COPD. This study examines the role of MIF in the pathogenesis of COPD. Mice deficient in MIF (Mif(-/-)) or the MIF receptor CD74 (Cd74(-/-)) and wild-type (WT) controls were aged for 6 mo. Both Mif(-/-) and Cd74(-/-) mice developed spontaneous emphysema by 6 mo of age compared with WT mice as measured by lung volume and chord length. This was associated with activation of the senescent pathway markers p53/21 and p16. Following exposure to cigarette smoke, Mif(-/-) mice were more susceptible to the development of COPD and apoptosis compared with WT mice. MIF plasma concentrations were measured in a cohort of 224 human participants. Within a subgroup of older current and former smokers (n = 72), MIF concentrations were significantly lower in those with COPD [8.8, 95%CI (6.7-11.0)] compared with those who did not exhibit COPD [12.7 ng/ml, 95%CI (10.6-14.8)]. Our results suggest that both MIF and the MIF receptor CD74 are required for maintenance of normal alveolar structure in mice and that decreases in MIF are associated with COPD in human subjects. PMID:24441872

Sauler, Maor; Leng, Lin; Trentalange, Mark; Haslip, Maria; Shan, Peiying; Piecychna, Marta; Zhang, Yi; Andrews, Nathaniel; Mannam, Praveen; Allore, Heather; Fried, Terri; Bucala, Richard; Lee, Patty J

2014-03-15

356

Inhibitory Smads: Mechanisms of Action and Roles in Human Diseases  

Microsoft Academic Search

Inhibitory Smads are one of the major inhibitory regulators of intracellular signaling mediated by TGF-? superfamily proteins.\\u000a Inhibitory Smads repress TGF-? superfamily signaling by several different mechanisms at the levels of cellular membrane, cytoplasm,\\u000a and nucleus. Importantly, expression of I-Smads is induced by TGF-? superfamily proteins themselves and other signaling pathways,\\u000a indicating a key role for I-Smads in negative feedback

Atsuhito Nakao

357

Inhibitory Ly49 Receptors on Mouse Natural Killer Cells  

Microsoft Academic Search

\\u000a The Ly49 receptors, which are expressed in a stochastic manner on subsets of murine natural killer (NK) cells, T cells, and\\u000a other cells, are encoded by the Klra gene family and include receptors with either inhibitory or activating function. All of the inhibitory Ly49 receptors are\\u000a characterized by an immunoreceptor tyrosine-based inhibitory motif in their cytoplasmic domain, which upon phosphorylation

Mark T. Orr; Lewis L. Lanier

358

A Lectin with Highly Potent Inhibitory Activity toward Breast Cancer Cells from Edible Tubers of Dioscorea opposita cv. Nagaimo  

PubMed Central

A 70-kDa galactose-specific lectin was purified from the tubers of Dioscorea opposita cv. nagaimo. The purification involved three chromatographic steps: anion exchange chromatography on a Q-Sepharose column, FPLC-anion exchange chromatography on a Mono Q column, and FPLC-gel filtration on a Superdex 75 column. The purified nagaimo lectin presented as a single 35-kDa band in reducing SDS-PAGE while it exhibited a 70-kDa single band in non-reducing SDS-PAGE suggesting its dimeric nature. Nagaimo lectin displayed moderate thermostability, retaining full hemagglutinating activity after heating up to 62°C for 30 minutes. It also manifested stability over a wide pH range from pH 2 to 13. Nagaimo lectin was a galactose-specific lectin, as evidenced by binding with galactose and galactose-containing sugars such as lactose and raffinose. The minimum concentration of galactose, lactose and raffinose required to exert an inhibitory effect on hemagglutinating activity of nagaimo lectin was 20 mM, 5 mM and 40 mM, respectively. Nagaimo lectin inhibited the growth of some cancer cell lines including breast cancer MCF7 cells, hepatoma HepG2 cells and nasopharyngeal carcinoma CNE2 cells, with IC50 values of 3.71 µM, 7.12 µM and 19.79 µM, respectively, after 24 hour treatment with nagaimo lectin. The induction of phosphatidylserine externalization and mitochondrial depolarization indicated that nagaimo lectin evoked apoptosis in MCF7 cells. However, the anti-proliferative activity of nagaimo lectin was not blocked by application of galactose, signifying that the activity was not related to the carbohydrate binding specificity of the lectin.

Chan, Yau Sang; Ng, Tzi Bun

2013-01-01

359

Minimum equipment guidelines for paediatric prehospital care  

PubMed Central

Prehospital care has become a well-defined specialty service in Canada, with various levels of paramedics providing specialized care to children before their arrival to hospital. The equipment required may vary according to the needs of the population being served and the level of training of the paramedics who are providing the care. The present statement provides a current list of the minimum equipment recommended for the provision of prehospital care to neonatal and paediatric patients. The most notable change to the present guideline is the addition of an automated external defibrillator, which has been added to reflect the most recent version of the paediatric advanced life support recommendations for the provision of basic life support.

Cheng, A; Hartfield, D

2011-01-01

360

Attosecond Pulse Shaping around a Cooper Minimum  

NASA Astrophysics Data System (ADS)

High harmonic generation (HHG) is used to measure the spectral phase of the recombination dipole matrix element (RDM) in argon over a broad frequency range that includes the 3p Cooper minimum (CM). The measured RDM phase agrees well with predictions based on the scattering phases and amplitudes of the interfering s- and d-channel contributions to the complementary photoionization process. The reconstructed attosecond bursts that underlie the HHG process show that the derivative of the RDM spectral phase, the group delay, does not have a straightforward interpretation as an emission time, in contrast to the usual attochirp group delay. Instead, the rapid RDM phase variation caused by the CM reshapes the attosecond bursts.

Schoun, S. B.; Chirla, R.; Wheeler, J.; Roedig, C.; Agostini, P.; DiMauro, L. F.; Schafer, K. J.; Gaarde, M. B.

2014-04-01

361

Minimum wear tube support hole design  

DOEpatents

A minimum-wear through-bore (16) is defined within a heat exchanger tube support plate (14) so as to have an hourglass configuration as determined by means of a constant radiused surface curvature (18) as defined by means of an external radius (R3), wherein the surface (18) extends between the upper surface (20) and lower surface (22) of the tube support plate (14). When a heat exchange tube (12) is disposed within the tube support plate (14) so as to pass through the through-bore (16), the heat exchange tube (12) is always in contact with a smoothly curved or radiused portion of the through-bore surface (16) whereby unacceptably excessive wear upon the heat exchange tube (12), as normally developed by means of sharp edges, lands, ridges, or the like conventionally part of the tube support plates, is eliminated or substantially reduced.

Glatthorn, Raymond H. (St. Petersburg, FL) [St. Petersburg, FL

1986-01-01

362

Minimum energy pathways via quantum Monte Carlo.  

PubMed

We perform quantum Monte Carlo (QMC) calculations to determine minimum energy pathways of simple chemical reactions, and compare the computed geometries and reaction barriers with those obtained with density functional theory (DFT) and quantum chemistry methods. We find that QMC performs in general significantly better than DFT, being also able to treat cases in which DFT is inaccurate or even unable to locate the transition state. Since the wave function form employed here is particularly simple and can be transferred to larger systems, we suggest that a QMC approach is both viable and useful for reactions difficult to address by DFT and system sizes too large for high level quantum chemistry methods. PMID:23464142

Saccani, S; Filippi, C; Moroni, S

2013-02-28

363

Minimum free-energy pathway of nucleation.  

PubMed

Nucleation in a two-component incompressible system was studied by examining the topology of the free-energy landscape. The properties of a single nucleus during nucleation were derived from the minimum free-energy pathway (MFEP) within the Cahn-Hilliard continuum theory of nucleation. MFEPs were computed using the string method. In particular, we have provided a detailed description of the nucleation process for a regular solution (T/T(c) = 0.8656) for increasing supersaturation up to the spinodal line. Two original results were found in terms of the physics of nucleation. A universal two-step behaviour was found whatever the supersaturation: nuclei sharply enrich up to equilibrium and then grow. Embryos show diffuse interfaces along the MFEP. The width of interfaces quickly saturates to its value at the critical nuclei and stays constant afterwards. PMID:21992325

Philippe, T; Blavette, D

2011-10-01

364

Attosecond Pulse Shaping around a Cooper Minimum.  

PubMed

High harmonic generation (HHG) is used to measure the spectral phase of the recombination dipole matrix element (RDM) in argon over a broad frequency range that includes the 3p Cooper minimum (CM). The measured RDM phase agrees well with predictions based on the scattering phases and amplitudes of the interfering s- and d-channel contributions to the complementary photoionization process. The reconstructed attosecond bursts that underlie the HHG process show that the derivative of the RDM spectral phase, the group delay, does not have a straightforward interpretation as an emission time, in contrast to the usual attochirp group delay. Instead, the rapid RDM phase variation caused by the CM reshapes the attosecond bursts. PMID:24785035

Schoun, S B; Chirla, R; Wheeler, J; Roedig, C; Agostini, P; Dimauro, L F; Schafer, K J; Gaarde, M B

2014-04-18

365

On a Minimum Problem in Smectic Elastomers  

SciTech Connect

Smectic elastomers are layered materials exhibiting a solid-like elastic response along the layer normal and a rubbery one in the plane. Balance equations for smectic elastomers are derived from the general theory of continua with constrained microstructure. In this work we investigate a very simple minimum problem based on multi-well potentials where the microstructure is taken into account. The set of polymeric strains minimizing the elastic energy contains a one-parameter family of simple strain associated with a micro-variation of the degree of freedom. We develop the energy functional through two terms, the first one nematic and the second one considering the tilting phenomenon; after, by developing in the rubber elasticity framework, we minimize over the tilt rotation angle and extract the engineering stress.

Buonsanti, Michele; Giovine, Pasquale [Dipartimento di Meccanica e Materiali, Facolta di Ingegneria, Universita Mediterranea, Via Graziella 1, localita Feo di Vito, I-89122, Reggio Calabria (Italy)

2008-07-08

366

30 CFR 75.1431 - Minimum rope strength.  

Code of Federal Regulations, 2010 CFR

...STANDARDS-UNDERGROUND COAL MINES Hoisting and Mantrips Wire Ropes § 75.1431 Minimum rope strength. At installation, the nominal strength...manufacturer's published catalog strength) of wire ropes used for hoisting shall meet the minimum rope...

2009-07-01

367

30 CFR 77.1431 - Minimum rope strength.  

Code of Federal Regulations, 2010 CFR

...UNDERGROUND COAL MINES Personnel Hoisting Wire Ropes § 77.1431 Minimum rope strength. At installation, the nominal strength...manufacturer's published catalog strength) of wire ropes used for hoisting shall meet the minimum rope...

2010-07-01

368

30 CFR 57.19021 - Minimum rope strength.  

Code of Federal Regulations, 2010 CFR

...METAL AND NONMETAL MINES Personnel Hoisting Wire Ropes § 57.19021 Minimum rope strength. At installation, the nominal strength...manufacturer's published catalog strength) of wire ropes used for hoisting shall meet the minimum rope...

2009-07-01

369

30 CFR 57.19021 - Minimum rope strength.  

Code of Federal Regulations, 2013 CFR

...METAL AND NONMETAL MINES Personnel Hoisting Wire Ropes § 57.19021 Minimum rope strength. At installation, the nominal strength...manufacturer's published catalog strength) of wire ropes used for hoisting shall meet the minimum rope...

2013-07-01

370

30 CFR 75.1431 - Minimum rope strength.  

Code of Federal Regulations, 2013 CFR

...STANDARDS-UNDERGROUND COAL MINES Hoisting and Mantrips Wire Ropes § 75.1431 Minimum rope strength. At installation, the nominal strength...manufacturer's published catalog strength) of wire ropes used for hoisting shall meet the minimum rope...

2013-07-01

371

30 CFR 75.1431 - Minimum rope strength.  

Code of Federal Regulations, 2010 CFR

...STANDARDS-UNDERGROUND COAL MINES Hoisting and Mantrips Wire Ropes § 75.1431 Minimum rope strength. At installation, the nominal strength...manufacturer's published catalog strength) of wire ropes used for hoisting shall meet the minimum rope...

2010-07-01

372

30 CFR 56.19021 - Minimum rope strength.  

Code of Federal Regulations, 2010 CFR

...METAL AND NONMETAL MINES Personnel Hoisting Wire Ropes § 56.19021 Minimum rope strength. At installation, the nominal strength...manufacturer's published catalog strength) of wire ropes used for hoisting shall meet the minimum rope...

2009-07-01

373

30 CFR 56.19021 - Minimum rope strength.  

Code of Federal Regulations, 2010 CFR

...METAL AND NONMETAL MINES Personnel Hoisting Wire Ropes § 56.19021 Minimum rope strength. At installation, the nominal strength...manufacturer's published catalog strength) of wire ropes used for hoisting shall meet the minimum rope...

2010-07-01

374

30 CFR 77.1431 - Minimum rope strength.  

Code of Federal Regulations, 2013 CFR

...UNDERGROUND COAL MINES Personnel Hoisting Wire Ropes § 77.1431 Minimum rope strength. At installation, the nominal strength...manufacturer's published catalog strength) of wire ropes used for hoisting shall meet the minimum rope...

2013-07-01

375

30 CFR 56.19021 - Minimum rope strength.  

Code of Federal Regulations, 2013 CFR

...METAL AND NONMETAL MINES Personnel Hoisting Wire Ropes § 56.19021 Minimum rope strength. At installation, the nominal strength...manufacturer's published catalog strength) of wire ropes used for hoisting shall meet the minimum rope...

2013-07-01

376

48 CFR 52.214-16 - Minimum Bid Acceptance Period.  

Code of Federal Regulations, 2013 CFR

...Clauses 52.214-16 Minimum Bid Acceptance Period. As prescribed...following provision in invitations for bids, except for construction, if the contracting officer determines...period must be specified: Minimum Bid Acceptance Period (APR...

2013-10-01

377

Theoretical Minimum Energies to Produce Steel for Selected Conditions.  

National Technical Information Service (NTIS)

The energy used to produce liquid steel in today's integrated and electric are furnace (EAF) facilities is significantly higher than the theoretical minimum energy requirements. This study presents the absolute minimum energy to produce steel ore and mixt...

R. J. Fruehan O. Fortini H. W. Paxton R. Brindle

2000-01-01

378

42 CFR 84.85 - Breathing bags; minimum requirements.  

Code of Federal Regulations, 2010 CFR

... 2010-10-01 2010-10-01 false Breathing bags; minimum requirements. 84.85 Section...RESPIRATORY PROTECTIVE DEVICES Self-Contained Breathing Apparatus § 84.85 Breathing bags; minimum requirements. (a)...

2010-10-01

379

42 CFR 84.79 - Breathing gas; minimum requirements.  

Code of Federal Regulations, 2010 CFR

... 2009-10-01 2009-10-01 false Breathing gas; minimum requirements. 84.79 Section...RESPIRATORY PROTECTIVE DEVICES Self-Contained Breathing Apparatus § 84.79 Breathing gas; minimum requirements. (a)...

2009-10-01

380

14 CFR 135.221 - IFR: Alternate airport weather minimums.  

Code of Federal Regulations, 2010 CFR

...2010-01-01 false IFR: Alternate airport weather minimums. 135.221 Section 135...AIRCRAFT VFR/IFR Operating Limitations and Weather Requirements § 135.221 IFR: Alternate airport weather minimums. No person may designate...

2010-01-01

381

14 CFR 135.221 - IFR: Alternate airport weather minimums.  

Code of Federal Regulations, 2010 CFR

...2009-01-01 false IFR: Alternate airport weather minimums. 135.221 Section 135...AIRCRAFT VFR/IFR Operating Limitations and Weather Requirements § 135.221 IFR: Alternate airport weather minimums. No person may designate...

2009-01-01

382

12 CFR 567.2 - Minimum regulatory capital requirement.  

Code of Federal Regulations, 2010 CFR

...2010-01-01 false Minimum regulatory capital requirement. 567.2 Section 567.2 Banks...Requirements § 567.2 Minimum regulatory capital requirement. (a) To meet its regulatory capital requirement a savings association must...

2010-01-01

383

12 CFR 567.2 - Minimum regulatory capital requirement.  

Code of Federal Regulations, 2010 CFR

...2009-01-01 false Minimum regulatory capital requirement. 567.2 Section 567.2 Banks...Requirements § 567.2 Minimum regulatory capital requirement. (a) To meet its regulatory capital requirement a savings association must...

2009-01-01

384

12 CFR 567.3 - Individual minimum capital requirements.  

Code of Federal Regulations, 2010 CFR

...2010-01-01 false Individual minimum capital requirements. 567.3 Section 567.3 Banks...THE TREASURY CAPITAL Regulatory Capital Requirements § 567.3 Individual minimum capital requirements. (a) Purpose and...

2010-01-01

385

12 CFR 567.3 - Individual minimum capital requirements.  

Code of Federal Regulations, 2010 CFR

...2009-01-01 false Individual minimum capital requirements. 567.3 Section 567.3 Banks...THE TREASURY CAPITAL Regulatory Capital Requirements § 567.3 Individual minimum capital requirements. (a) Purpose and...

2009-01-01

386

50 CFR 648.104 - Summer flounder minimum fish sizes.  

Code of Federal Regulations, 2013 CFR

... 2013-10-01 2013-10-01 false Summer flounder minimum fish sizes. 648.104 ...UNITED STATES Management Measures for the Summer Flounder Fisheries § 648.104 Summer flounder minimum fish sizes. (a)...

2013-10-01

387

46 CFR 42.20-75 - Minimum freeboards.  

Code of Federal Regulations, 2013 CFR

...20-75 Minimum freeboards. (a) Summer freeboard. (1) The minimum freeboard in summer must be the freeboard derived from the...freeboard obtained by a deduction from the summer freeboard of one forty-eighth of...

2013-10-01

388

42 CFR 84.117 - Gas mask containers; minimum requirements.  

Code of Federal Regulations, 2012 CFR

...Health 1 2012-10-01 2012-10-01 false Gas mask containers; minimum requirements. 84.117...ACTIVITIES APPROVAL OF RESPIRATORY PROTECTIVE DEVICES Gas Masks § 84.117 Gas mask containers; minimum requirements....

2012-10-01

389

14 CFR 171.5 - Minimum requirements for approval.  

...Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) NAVIGATIONAL FACILITIES NON-FEDERAL NAVIGATION FACILITIES VOR Facilities § 171.5 Minimum requirements for approval. (a) The following are the minimum...

2014-01-01

390

42 CFR 84.72 - Breathing tubes; minimum requirements.  

Code of Federal Regulations, 2013 CFR

...2013-10-01 2013-10-01 false Breathing tubes; minimum requirements. 84.72 Section...Breathing Apparatus § 84.72 Breathing tubes; minimum requirements. Flexible breathing tubes used in conjunction with breathing...

2013-10-01

391

42 CFR 84.132 - Breathing tubes; minimum requirements.  

Code of Federal Regulations, 2013 CFR

...2013-10-01 2013-10-01 false Breathing tubes; minimum requirements. 84.132 Section...Supplied-Air Respirators § 84.132 Breathing tubes; minimum requirements. Flexible breathing tubes used in conjunction with supplied-air...

2013-10-01

392

42 CFR 84.172 - Breathing tubes; minimum requirements.  

Code of Federal Regulations, 2013 CFR

...2013-10-01 2013-10-01 false Breathing tubes; minimum requirements. 84.172 Section...Particulate Respirators § 84.172 Breathing tubes; minimum requirements. Flexible breathing tubes used in conjunction with respirators...

2013-10-01

393

42 CFR 84.195 - Breathing tubes; minimum requirements.  

Code of Federal Regulations, 2013 CFR

...2013-10-01 2013-10-01 false Breathing tubes; minimum requirements. 84.195 Section...Cartridge Respirators § 84.195 Breathing tubes; minimum requirements. Flexible breathing tubes used in conjunction with respirators...

2013-10-01

394

42 CFR 84.115 - Breathing tubes; minimum requirements.  

Code of Federal Regulations, 2013 CFR

...2013-10-01 2013-10-01 false Breathing tubes; minimum requirements. 84.115 Section...DEVICES Gas Masks § 84.115 Breathing tubes; minimum requirements. Flexible breathing tubes used in conjunction with gas masks shall...

2013-10-01

395

77 FR 43196 - Minimum Internal Control Standards and Technical Standards  

Federal Register 2010, 2011, 2012, 2013

...GAMING COMMISSION 25 CFR Parts 543 and 547 Minimum Internal Control Standards and Technical Standards AGENCY: National...SUPPLEMENTARY INFORMATION: Part 543 addresses minimum internal control standards (MICS) for Class II gaming...

2012-07-24

396

20 CFR 225.15 - Overall Minimum PIA.  

Code of Federal Regulations, 2013 CFR

...true Overall Minimum PIA. 225.15 Section 225.15 Employees' Benefits RAILROAD...Divorced Spouse Annuities § 225.15 Overall Minimum PIA. The Overall...employee would be eligible for an old age insurance benefit or a...

2013-04-01

397

42 CFR 425.706 - Minimum necessary data.  

Code of Federal Regulations, 2013 CFR

...2013-10-01 false Minimum necessary data. 425.706 Section 425.706 Public...CONTINUED) MEDICARE SHARED SAVINGS PROGRAM Data Sharing With ACOs § 425.706 Minimum necessary data. (a) ACOs must limit their...

2013-10-01

398

Asymptotically minimum bit error rate block precoders for minimum mean square error equalization  

Microsoft Academic Search

We determine linear block precoders which asymptotically minimize the bit error rate (BER) of block-based communication systems employing minimum mean square error (MMSE) equalization and threshold detection. The problem is solved by a two-stage optimization procedure in which a lower bound on the BER over its convex region is first minimized, followed by showing that this lower bound is actually

Scarlett S. Chan; Timothy N. Davidson; K. M. Wong

2002-01-01

399

Determining Concentration  

NSDL National Science Digital Library

Students quantify the percent of light reflected from solutions containing varying concentrations of red dye using LEGO© MINDSTORMS© NXT bricks and light sensors. They begin by analyzing a set of standard solutions with known concentrations of food coloring, and plot data to graphically determine the relationship between percent reflected light and dye concentration. Then they identify dye concentrations for two unknown solution samples based on how much light they reflect. Students gain an understanding of light scattering applications and how to determine properties of unknown samples based on a set of standard samples.

Applying Mechatronics to Promote Science (AMPS) GK-12 Program,

400

Minimum Wages for Ronald McDonald Monopsonies  

Microsoft Academic Search

Abstract Recent empirical work on the effects of minimum,wages has called into question the conventional wisdom,that minimum,wages invariably reduce employment. We develop a model ofmonopsonistic competition with free entry to analyse the effects of minimum wages, and our predictions fit the em- pirical results closely. Under monopsonistic competition, we find that a rise in the minimum wage a) raises employment

V. Bhaskar; Ted To

401

On the Minimum Weight Steiner Triangular Tiling problem  

SciTech Connect

In this paper, we introduce the Minimum Weight Steiner Triangular Tiling problem, which is a generalization of the Minimum Weight Steiner Triangulation. Contrary to the conjecture of Eppstein that the Minimum Weight Steiner Triangulation of a convex polygon has the property that the Steiner points all lie on the boundary of the polygon [Epp94], we show that the Steiner points of a Minimum Weight Steiner Triangular Tiling could lie in the interior of a convex polygon.

Doddi, S.; Zhu, B.

1995-04-01

402

Acetylcholinesterase inhibitory activity of Haplophyton cimicidum.  

PubMed

In Oaxaca, México, Haplophyton cimicidum is used in combination with other plants as part of a folk strategy against arthropod pests of crops and cattle. Methanolic and crude alkaloid (acid-base extraction) extracts of H. cimicidum leaves were analysed by thin-layer chromatography (TLC) and assayed in vitro for acetylcholinesterase (AChE) inhibitory activity using Spodoptera frugiperda homogenates as source of enzyme. Derivatised chromatographic plates indicated the presence of indoles and alkaloids in the extracts. The crude alkaloid extract exhibited a higher number of compounds than the methanolic extract as judged by the number of spots on TLC plates. The crude alkaloid extract had a weak inhibition potential of AChE with a lower IC50 (93 ?g mL(-1)) than the methanolic extract (159 ?g mL(-1)). Indole alkaloids may be responsible for the activity, though a subsequent analysis of the extract components is necessary to determine the active alkaloid(s). PMID:24484055

Llanos-Romero, R E; Cárdenas, R; Zúńiga, B; Herrera-Santoyo, J; Guevara-Fefer, P

2014-01-01

403

Urease inhibitory constituents from Daphne retusa.  

PubMed

The bioassay-guided fractionation of Daphne retusa Hemsl. has led to the isolation of a new aryl tetrahydronaphthalene lignan derivative named as daphnretusic acid (1), along with six new source compounds such as 5,7-dihydroxyflavone (2), 7-hydroxyflavone (3), 6-methoxyflavone (4), (+) pinoresinol (5), (+) sesamin (6), and ?-sitosterol-3-O-?-D-glucopyranoside (7). Their structures were elucidated by (1)H NMR, (13)C NMR, 1D, 2D NMR, UV, IR, and EIMS analyses. All the fractions (n-hexane, CHCl3, AcOEt, CH3OH, and water) and pure compounds (1-7) were subjected to the assay of urease and ?-chymotrypsin inhibitory activities. Chloroform and methanol soluble fractions showed moderate urease inhibition. Compound 2 exhibited significant urease inhibition with IC50 value 60.4 ± 0.72 ?M, whereas compounds 1 and 3-7 remained inactive during urease inhibition and ?-chymotrypsin bioassays. PMID:24266421

Mansoor, Farrukh; Anis, Itrat; Khan, Ajmal; Marasini, Bishnu P; Choudhary, Muhammad Iqbal; Shah, Muhammad Raza

2014-01-01

404

Controlling Synfire Chain by Inhibitory Synaptic Input  

NASA Astrophysics Data System (ADS)

The propagation of highly synchronous firings across neuronal networks, called the synfire chain, has been actively studied both theoretically and experimentally. The temporal accuracy and remarkable stability of the propagation have been repeatedly examined in previous studies. However, for such a mode of signal transduction to play a major role in processing information in the brain, the propagation should also be controlled dynamically and flexibly. Here, we show that inhibitory but not excitatory input can bidirectionally modulate the propagation, i.e., enhance or suppress the synchronous firings depending on the timing of the input. Our simulations based on the Hodgkin-Huxley neuron model demonstrate this bidirectional modulation and suggest that it should be achieved with any biologically inspired modeling. Our finding may help describe a concrete scenario of how multiple synfire chains lying in a neuronal network are appropriately controlled to perform significant information processing.

Shinozaki, Takashi; Câteau, Hideyuki; Urakubo, Hidetoshi; Okada, Masato

2007-04-01

405

Inhibitory Effect of Black and Red Pepper and Thyme Extracts and Essential Oils on Enterohemorrhagic Escherichia coli and DNase Activity of Staphylococcus aureus.  

PubMed

In this study, extracts and essential oils of Black and Red pepper and Thyme were tested for antibacterial activity against Escherichia coli O157: H7 and Staphylococcus aureus. Black and Red pepper and Thyme were provided from Iranian agricultural researches center. 2 g of each plant powder was added to 10 cc ethanol 96°. After 24 h, the crude extract was separated as an alcoholic extract and concentrated by distillation method. Plants were examined for determining their major component and essential oils were separated. Phytochemical analyses were done for detection of some effective substances in extracts. The antibacterial activity against Escherichia coli O157: H7 and Staphylococcus aureus was tested and the results showed that all extracts and essential oils were effective and essential oils were more active. The extracts and oils that showed antimicrobial activity were later tested to determine the Minimum Inhibitory Dilution (MID) for those bacteria. They were also effective on the inhibition of DNase activity. This study was indicated that extracts and essential oils of Black and Red pepper and Thyme can play a significant role in inhibition of Escherichia coli O157: H7 and Staphylococcus aureus. PMID:24250643

Zarringhalam, Maryam; Zaringhalam, Jalal; Shadnoush, Mehdi; Safaeyan, Firouzeh; Tekieh, Elaheh

2013-01-01

406

A Novel Lectin with Antiproliferative and HIV-1 Reverse Transcriptase Inhibitory Activities from Dried Fruiting Bodies of the Monkey Head Mushroom Hericium erinaceum  

PubMed Central

A lectin designated as Hericium erinaceum agglutinin (HEA) was isolated from dried fruiting bodies of the mushroom Hericium erinaceum with a chromatographic procedure which entailed DEAE-cellulose, CM-cellulose, Q-Sepharose, and FPLC Superdex 75. Its molecular mass was estimated to be 51?kDa and its N-terminal amino acid sequences was distinctly different from those of other isolated mushroom lectins. The hemagglutinating activity of HEA was inhibited at the minimum concentration of 12.5?mM by inulin. The lectin was stable at pH 1.9–12.1 and at temperatures up to 70°C, but was inhibited by Hg2+, Cu2+, and Fe3+ ions. The lectin exhibited potent mitogenic activity toward mouse splenocytes, and demonstrated antiproliferative activity toward hepatoma (HepG2) and breast cancer (MCF7) cells with an IC50 of 56.1??M and 76.5??M, respectively. It manifested HIV-1 reverse transcriptase inhibitory activity with an IC50 of 31.7??M. The lectin exhibited potent mitogenic activity toward murine splenocytes but was devoid of antifungal activity.

Li, Yanrui; Zhang, Guoqing; Ng, Tzi Bun; Wang, Hexiang

2010-01-01

407

Aqueous and Organic Solvent-Extracts of Selected South African Medicinal Plants Possess Antimicrobial Activity against Drug-Resistant Strains of Helicobacter pylori: Inhibitory and Bactericidal Potential  

PubMed Central

The aim of this study was to identify sources of cheap starting materials for the synthesis of new drugs against Helicobacter pylori. Solvent-extracts of selected medicinal plants; Combretum molle, Sclerocarya birrea, Garcinia kola, Alepidea amatymbica and a single Strychnos species were investigated against 30 clinical strains of H. pylori alongside a reference control strain (NCTC 11638) using standard microbiological techniques. Metronidazole and amoxicillin were included in these experiments as positive control antibiotics. All the plants demonstrated anti-H. pylori activity with zone diameters of inhibition between 0 and 38 mm and 50% minimum inhibitory concentration (MIC50) values ranging from 0.06 to 5.0 mg/mL. MIC50 values for amoxicillin and metronidazole ranged from 0.001 to 0.63 mg/mL and 0.004 to 5.0 mg/mL respectively. The acetone extracts of C. molle and S. birrea exhibited a remarkable bactericidal activity against H. pylori killing more than 50% of the strains within 18 h at 4× MIC and complete elimination of the organisms within 24 h. Their antimicrobial activity was comparable to the control antibiotics. However, the activity of the ethanol extract of G. kola was lower than amoxicillin (P < 0.05) as opposed to metronidazole (P > 0.05). These results demonstrate that S. birrea, C. molle and G. kola may represent good sources of compounds with anti-H. pylori activity.

Njume, Collise; Jide, Afolayan A.; Ndip, Roland N.

2011-01-01

408

Dealing with monopsony power: Employment subsidies vs. minimum wages  

Microsoft Academic Search

We show in a monopsony model that accounting for changes in hours a minimum wage has ambiguous effects on employment and welfare. When all workers have the same preference ordering over leisure and consumption employment subsidies unambiguously improve welfare. Many countries have minimum wages and also tax minimum wage workers.

Eric Strobl; Frank Walsh

2007-01-01

409

42 CFR 422.382 - Minimum net worth amount.  

Code of Federal Regulations, 2010 CFR

...2010-10-01 2010-10-01 false Minimum net worth amount. 422.382 Section 422...Provider-Sponsored Organizations § 422.382 Minimum net worth amount. (a) At the time an...part, the organization must have a minimum net worth amount, as determined under...

2010-10-01

410

42 CFR 422.382 - Minimum net worth amount.  

Code of Federal Regulations, 2011 CFR

...2011-10-01 2011-10-01 false Minimum net worth amount. 422.382 Section 422...Provider-Sponsored Organizations § 422.382 Minimum net worth amount. (a) At the time an...part, the organization must have a minimum net worth amount, as determined under...

2011-10-01

411

42 CFR 422.382 - Minimum net worth amount.  

Code of Federal Regulations, 2012 CFR

...2012-10-01 2012-10-01 false Minimum net worth amount. 422.382 Section 422...Provider-Sponsored Organizations § 422.382 Minimum net worth amount. (a) At the time an...part, the organization must have a minimum net worth amount, as determined under...

2012-10-01

412

50 CFR 648.72 - Minimum surf clam size.  

Code of Federal Regulations, 2010 CFR

...2009-10-01 2009-10-01 false Minimum surf clam size. 648.72 Section 648.72 Wildlife...Management Measures for the Atlantic Surf Clam and Ocean Quahog Fisheries § 648.72 Minimum surf clam size. (a) Minimum length. The...

2009-10-01

413

50 CFR 648.72 - Minimum surf clam size.  

Code of Federal Regulations, 2010 CFR

...2010-10-01 2010-10-01 false Minimum surf clam size. 648.72 Section 648.72 Wildlife...Management Measures for the Atlantic Surf Clam and Ocean Quahog Fisheries § 648.72 Minimum surf clam size. (a) Minimum length. The...

2010-10-01

414

Making Work Pay: The Case for Raising the Minimum Wage.  

National Technical Information Service (NTIS)

Americans know a raise in the minimum wage is one way to help make work pay. For many working Americans an increase in the minimum wage will make the difference between living in poverty and not. Furthermore, a higher minimum wage -- a floor to ensure wor...

1996-01-01

415

50 CFR 648.93 - Monkfish minimum fish sizes.  

Code of Federal Regulations, 2013 CFR

...2013-10-01 false Monkfish minimum fish sizes. 648.93 Section 648.93...Fisheries § 648.93 Monkfish minimum fish sizes. (a) General provisions. ...Federal monkfish permit must meet the minimum fish size requirements established in this...

2013-10-01

416

50 CFR 648.165 - Bluefish minimum fish sizes.  

Code of Federal Regulations, 2013 CFR

...2013-10-01 false Bluefish minimum fish sizes. 648.165 Section 648.165...Fishery § 648.165 Bluefish minimum fish sizes. If the MAFMC determines through...framework adjustment process that minimum fish sizes are necessary to ensure that...

2013-10-01

417

50 CFR 648.126 - Scup minimum fish sizes.  

Code of Federal Regulations, 2013 CFR

... 2013-10-01 false Scup minimum fish sizes. 648.126 Section 648.126...Scup Fishery § 648.126 Scup minimum fish sizes. (a) Moratorium (commercially...c) The minimum size applies to whole fish or any part of a fish found in...

2013-10-01

418

Feeding deterrent and growth inhibitory activities of PONNEEM, a newly developed phytopesticidal formulation against Helicoverpa armigera (Hubner)  

PubMed Central

Objective To assess the feeding deterrent, growth inhibitory and egg hatchability effects of PONNEEM on Helicoverpa armigera (H. armigera). Methods Five oil formulations were prepared at different ratios to assess the feeding deterrent, growth inhibitory and egg hatchability effects on H. armigera. Results Invariably all the newly formulated phytopesticidal oil formulations showed the feeding deterrent and growth inhibitory activities against H. armigera. The maximum feeding deterrent activity of 88.44% was observed at 15 µL/L concentration of PONNEEM followed by formulation A (74.54%). PONNEEM was found to be effective in growth inhibitory activities and egg hatchability at 10 µL/L concentration. It exhibited statistically significant feeding deterrent activity and growth inhibitory activity compared with all the other treatments. Conclusions PONNEEM was found to be effective phytopesticidal formulation to control the larval stage of H. armigera. This is the first report for the feeding deterrent activity of PONNEEM against H. armigera. This newly formulated phytopesticide was patented in India.

Packiam, Soosaimanickam Maria; Baskar, Kathirvelu; Ignacimuthu, Savarimuthu

2014-01-01

419

Personal Assessments of Minimum Income and Expenses: What Do They Tell Us About 'Minimum Living' Thresholds and Equivalence Scales.  

National Technical Information Service (NTIS)

Subjective minimum income (MIQ) and minimum spending (MSQ) are the study focus. Basic Needs Module (1995) data from the U.S. Survey of Income and Program Participation are analyzed. A regression intersection approach is used to estimate household threshol...

T. I. Garner K. Short

2005-01-01

420

Effects of the coral calcium as an inhibitory substance against colon cancer and its metastasis in the lungs  

Microsoft Academic Search

Growth rates of mouse Colon 26 cancer cells were observed in acidic culture media and weak alkaline culture media. Coral Calcium exhibited an inhibitory effect on the growth of cancer cells in weak alkaline (pH 7.5) culture medium (in vitro). In addition, the effect of Coral Calcium concentration against Colon 26 cancer cells was investigated using calcium carbonate as a

Yuji Hirota; Takashi Sugisaki

2000-01-01

421

Inhibitory activities of aromatic amino acid esters and peptides against ovalbumin permeation through Caco-2 cell monolayers.  

PubMed

Trp, Phe, and Tyr ethyl esters and their dipeptides with Gly at the C-terminals inhibited ovalbumin (OVA) permeation through Caco-2 monolayers. The inhibitory activity of Trp ethyl ester was the highest at near the concentration of 10(-6) M. It was suggested that Trp ethyl ester inhibited transcellular permeation of OVA. PMID:14646220

Kobayashi, Shoko; Watanabe, Jun

2003-11-01

422

Routing Algorithm based on Minimum Spanning Tree and Minimum Cost Flow for Hybrid Wireless-optical Broadband Access Network  

NASA Astrophysics Data System (ADS)

In order to minimize the average end to end delay for data transporting in hybrid wireless optical broadband access network, a novel routing algorithm named MSTMCF (minimum spanning tree and minimum cost flow) is devised. The routing problem is described as a minimum spanning tree and minimum cost flow model and corresponding algorithm procedures are given. To verify the effectiveness of MSTMCF algorithm, extensively simulations based on OWNS have been done under different types of traffic source.

Le, Zichun; Suo, Kaihua; Fu, Minglei; Jiang, Ling; Dong, Wen

2012-03-01

423

Macrofaunal colonization across the Indian margin oxygen minimum zone  

NASA Astrophysics Data System (ADS)

There is a growing need to understand the ability of bathyal assemblages to recover from disturbance and oxygen stress, as human activities and expanding oxygen minimum zones increasingly affect deep continental margins. The effects of a pronounced oxygen minimum zone (OMZ) on slope benthic community structure have been studied on every major upwelling margin; however, little is known about the dynamics or resilience of these benthic populations. To examine the influence of oxygen and phytodetritus on short-term settlement patterns, we conducted colonization experiments at 3 depths on the West Indian continental margin. Four colonization trays were deployed at each depth for 4 days at 542 and 802 m (transect 1-16°58' N) and for 9 days at 817 and 1147 m (transect 2-17°31' N). Oxygen concentrations ranged from 0.9 ?M (0.02 mL L-1) at 542 m to 22 ?M (0.5 mL L-1) at 1147 m. All trays contained local defaunated sediments; half of the trays at each depth also contained 13C/15N-labeled phytodetritus mixed into the sediments. Sediment cores were collected between 535 m and 1140 m from 2 cross-margin transects for analysis of ambient (source) macrofaunal (>300 ?m) densities and composition. Ambient macrofaunal densities ranged from 0 ind m-2 (at 535-542 m) to 7400 ind m-2, with maximum values on both transects at 700-800 m. Macrofaunal colonizer densities ranged from 0 ind m-2 at 542 m, where oxygen was lowest, to average values of 142 ind m-2 at 800 m, and 3074 ind m-2 at 1147 m, where oxygen concentration was highest. These were equal to 4.3 and 151% of the ambient community at 800 m and 1147 m, respectively. Community structure of settlers showed no response to the presence of phytodetritus. Increasing depth and oxygen concentration, however, significantly influenced the community composition and abundance of colonizing macrofauna. Polychaetes constituted 92.4% of the total colonizers, followed by crustaceans (4.2%), mollusks (2.5%), and echinoderms (0.8%). The majority of colonizers were found at 1147 m; 88.5% of these were Capitella sp., although they were rare in the ambient community. Colonists at 800 and 1147 m also included ampharetid, spionid, syllid, lumbrinerid, cirratulid, cossurid and sabellid polychaetes. Consumption of 13C/15N-labeled phytodetritus was observed for macrofaunal foraminifera (too large to be colonizers) at the 542 and 802/817 m sites, and by metazoan macrofauna mainly at the deepest, better oxygenated sites. Calcareous foraminifera (Uvigerina, Hoeglundina sp.), capitellid polychaetes and cumaceans were among the major phytodetritus consumers. These preliminary experiments suggest that bottom-water oxygen concentrations may strongly influence ecosystem services on continental margins, as reflected in rates of colonization by benthos and colonizer processing of carbon following disturbance. They may also provide a window into future patterns of settlement on the continental slope as the world's oxygen minimum zones expand.

Levin, L. A.; McGregor, A. L.; Mendoza, G. F.; Woulds, C.; Cross, P.; Witte, U.; Gooday, A. J.; Cowie, G.; Kitazato, H.

2013-11-01

424

Minimum Energy Requirements for Sustained Microbial Activity in Anoxic Sediments  

NASA Technical Reports Server (NTRS)

Currently understood mechanisms of biochemical energy conservation dictate that, in order to be biologically useful, energy must be available to organisms in "quanta" equal to, at minimum one-third to one-fifth of the energy required to synthesize ATP in vivo. The existence of this biological energy quantum means that a significant fraction of the chemical amp on Earth cannot be used to drive biological productivity, and places a fundamental thermodynamic constraint on the origins, evolution, and distribution of life. We examined the energy requirements of intact microbial assemblages in anoxic sediments from Cape Lookout Bight, NC, USA, using dissolved hydrogen concentrations as a non-invasive probe. In this system, the thermodynamics of metabolic processes occurring inside microbial cells is reflected quantitatively by H2 concentrations measured outside those cells. We find that methanogenic archaea are supported by energy yields as small as 10 kJ per mol, about half the quantity calculated from studies of microorganisms in culture. This finding implies that a significantly broader range of geologic and chemical niches might be exploited by microorganisms than would otherwise be expected.

Hoehler, Tori M.; Alperin, Marc J.; Albert, Daniel B.; Martens, Christoper S.; DeVincenzi, Donald L. (Technical Monitor)

2000-01-01

425

Inhibitory Control Predicts Language Switching Performance in Trilingual Speech Production  

ERIC Educational Resources Information Center

This study investigated the role of domain-general inhibitory control in trilingual speech production. Taking an individual differences approach, we examined the relationship between performance on a non-linguistic measure of inhibitory control (the Simon task) and a multilingual language switching task for a group of fifty-six native English (L1)…

Linck, Jared A.; Schwieter, John W.; Sunderman, Gretchen

2012-01-01

426

Paradoxical Effects of External Modulation of Inhibitory Interneurons  

Microsoft Academic Search

The neocortex, hippocampus, and several other brain regions contain populations of excitatory principal cells with recurrent connections and strong interactions with local inhibitory inter- neurons. To improve our understanding of the interactions among these cell types, we modeled the dynamic behavior of this type of network, including external inputs. A surprising finding was that increasing the direct external inhibitory input

Misha V. Tsodyks; William E. Skaggs; Terrence J. Sejnowski; Bruce L. McNaughton

1997-01-01

427

Neural Mechanisms of Inhibitory Specification in Cognitive and Linguistic Complexity  

Microsoft Academic Search

We theorize that the ability to organize a complex linguistic structure such as a hierarchic clause may depend upon the capacity for what may be called inhibitory specification, in which certain meanings are isolated within working memory, such that they can be sustained and grouped within hierarchic structures. Clues to the neural mechanisms of inhibitory specification can be gained from

Don M. Tucker

428

Concentrating Radioactivity  

ERIC Educational Resources Information Center

By concentrating radioactivity contained on luminous dials, a teacher can make a high reading source for classroom experiments on radiation. The preparation of the source and its uses are described. (DT)

Herrmann, Richard A.

1974-01-01

429

Histamine H 3 receptor-mediated suppression of inhibitory synaptic transmission in the submucous plexus of guinea-pig small intestine  

Microsoft Academic Search

Conventional intracellular microelectrodes and marker injection techniques were used to study the actions of histamine on inhibitory synaptic transmission in the submucous plexus of guinea-pig small intestine. Bath application of histamine (1–300 ?M) reversibly suppressed both noradrenergic and non-adrenergic slow inhibitory postsynaptic potentials in a concentration-dependent manner. These effects of histamine were mimicked by the selective histamine H3 receptor agonist

Sumei Liu; Yun Xia; Hong-Zhen Hu; Jun Ren; Chuanyun Gao; Jackie D. Wood

2000-01-01

430

An Extract of Gymnema sylvestre Leaves and Purified Gymnemic Acid Inhibits Glucose-Stimulated Gastric Inhibitory Peptide Secretion in Rats1  

Microsoft Academic Search

Gastric inhibitory peptide release into the portal vein in response to duodenal infusion of D-glucose was studied in the presence of a leaf extract of Gymnema sylvestre, purified gymnemic acid and inhi bitors of some putative glucose sensors and carriers in the intestinal lumen. Intraduodenal infusion of D-glucose significantly increased the portal immunoreactive gastric inhibitory peptide concentration in a dose-dependent

AYAKO KOJIMA

431

Inhibitory processes in visual perception: A bilingual advantage.  

PubMed

Bilingual inhibitory control advantages are well established. An open question is whether inhibitory superiority also extends to visual perceptual phenomena that involve inhibitory processes. This research used ambiguous figures to assess inhibitory bilingual superiority in 3-, 4-, and 5-year-old mono- and bilingual children (N=141). Findings show that bilinguals across all ages are superior in inhibiting a prevalent interpretation of an ambiguous figure to perceive the alternative interpretation. In contrast, mono- and bilinguals revealed no differences in understanding that an ambiguous figure can have two distinct referents. Together, these results suggest that early bilingual inhibitory control superiority is also evident in visual perception. Bilinguals' conceptual understanding of figure ambiguity is comparable to that of their monolingual peers. PMID:24878102

Wimmer, Marina C; Marx, Christina

2014-10-01

432

Solar Activity Heading for a Maunder Minimum?  

Microsoft Academic Search

Long-range (few years to decades) solar activity prediction techniques vary greatly in their methods. They range from examining planetary orbits, to spectral analyses (e.g. Fourier, wavelet and spectral analyses), to artificial intelligence methods, to simply using general statistical techniques. Rather than concentrate on statistical\\/mathematical\\/numerical methods, we discuss a class of methods which appears to have a \\

K. H. Schatten; W. K. Tobiska

2003-01-01

433

The Inhibitory Effect of Prunella vulgaris L. on Aldose Reductase and Protein Glycation  

PubMed Central

To evaluate the aldose reductase (AR) enzyme inhibitory ability of Prunella vulgaris L. extract, six compounds were isolated and tested for their effects. The components were subjected to in vitro bioassays to investigate their inhibitory assays using rat lens aldose reductase (rAR) and human recombinant AR (rhAR). Among them, caffeic acid ethylene ester showed the potent inhibition, with the IC50 values of rAR and rhAR at 3.2 ± 0.55??M and 12.58 ± 0.32??M, respectively. In the kinetic analyses using Lineweaver-Burk plots of 1/velocity and 1/concentration of substrate, this compound showed noncompetitive inhibition against rhAR. Furthermore, it inhibited galactitol formation in a rat lens incubated with a high concentration of galactose. Also it has antioxidative as well as advanced glycation end products (AGEs) inhibitory effects. As a result, this compound could be offered as a leading compound for further study as a new natural products drug for diabetic complications.

Li, Hong Mei; Kim, Jin Kyu; Jang, Jai Man; Kwon, Sang Oh; Cui, Cheng Bi; Lim, Soon Sung

2012-01-01

434

Long-lasting inhibitory effects of saquinavir and ritonavir on OATP1B1-mediated uptake.  

PubMed

Previously, we reported a long-lasting inhibition of transport mediated by organic anion-transporting polypeptides (OATPs) in humans and rats by cyclosporin A (CsA). In the present study, we examined the effects of several other compounds on OATP1B1-mediated transport, with a focus on long-lasting inhibition. Effects of coincubation, preincubation, or preincubation plus coincubation of 12 compounds on uptake of estrone 3-sulfate (E1 S) in OATP1B1-expressing HEK293T cells were examined. The OATP1B1 inhibitors used in the present study inhibited OATP1B1-mediated uptake of E1 S in a concentration-dependent manner. Among them, saquinavir and ritonavir in addition to CsA exhibited long-lasting inhibitory effects on OATP1B1-mediated transport of E1 S at ? 5 and 25 ?M, respectively, even after they were washed out from the incubation buffer. After preincubation with saquinavir, its inhibitory effect on OATP1B1 remained for at least 6 h, whereas the effect of ritonavir did not remain. Protein expression of OATP1B1 was not altered by preincubation with 25 ?M saquinavir or ritonavir. The present study firstly showed that saquinavir and ritonavir as well as CsA have long-lasting inhibitory effects on OATP1B1. But, at plasma unbound concentrations of saquinavir and ritonavir in clinical situations, they may not cause long-lasting inhibition of OATP1B1. PMID:23440887

Shitara, Yoshihisa; Takeuchi, Kumiko; Horie, Toshiharu

2013-09-01

435

Jojoba seed meal proteins associated with proteolytic and protease inhibitory activities.  

PubMed

The jojoba, Simmondsia chinensis, is a characteristic desert plant native to the Sonoran desert. The jojoba meal after oil extraction is rich in protein. The major jojoba proteins were albumins (79%) and globulins (21%), which have similar amino acid compositions and also showed a labile thrombin-inhibitory activity. SDS-PAGE showed two major proteins at 50 kDa and 25 kDa both in the albumins and in the globulins. The 25 kDa protein has trypsin- and chymotrypsin-inhibitory activities. In vitro digestibility of the globulins and albumins resembled that of casein and soybean protein concentrates and was increased after heat treatment. The increased digestibility achieved by boiling may be attributed to inactivation of the protease inhibitors and denaturation of proteins. PMID:12236696

Shrestha, Madan K; Peri, Irena; Smirnoff, Patricia; Birk, Yehudith; Golan-Goldhirsh, Avi

2002-09-25

436

Inhibitory effect of vanillin on cellulase activity in hydrolysis of cellulosic biomass.  

PubMed

Pretreatment of lignocellulosic material produces a wide variety of inhibitory compounds, which strongly inhibit the following enzymatic hydrolysis of cellulosic biomass. Vanillin is a kind of phenolics derived from degradation of lignin. The effect of vanillin on cellulase activity for the hydrolysis of cellulose was investigated in detail. The results clearly showed that vanillin can reversibly and non-competitively inhibit the cellulase activity at appropriate concentrations and the value of IC50 was estimated to be 30g/L. The inhibition kinetics of cellulase by vanillin was studied using HCH-1 model and inhibition constants were determined. Moreover, investigation of three compounds with similar structure of vanillin on cellulase activity demonstrated that aldehyde group and phenolic hydroxyl groups of vanillin had inhibitory effect on cellulase. These results provide valuable and detailed information for understanding the inhibition of lignin derived phenolics on cellulase. PMID:24997375

Li, Yun; Qi, Benkun; Wan, Yinhua

2014-09-01

437

Melanogenesis Inhibitory Activity of Two Generic Drugs: Cinnarizine and Trazodone in Mouse B16 Melanoma Cells  

PubMed Central

More than 200 generic drugs were screened to identify the inhibitory activity on melanogenesis in mouse B16 melanoma cells. Cinnarizine and trazodone were identified as melanogenesis inhibitors. The inhibitory effects of the two drugs on cell survival, melanogenesis, and tyrosinase activity were investigated. The results showed that both cinnarizine and trazodone inhibited melanogenesis in B16 cells by a dose-dependent manner at the non-cytotoxic concentrations. Based on the results of the present study, seeking new melanogenesis inhibitors from generic drugs is an alternative approach to developing new depigmenting agents in cosmeceuticals. Moreover, cinnarizine and trazodone were proven to be good candidates as skin-whitening agents for treatment of skin hyperpigmentation.

Chang, Te-Sheng; Lin, Victor Chia-Hsiang

2011-01-01

438

GC-MS-Based Metabolite Profiling of Cosmos caudatus Leaves Possessing Alpha-Glucosidase Inhibitory Activity.  

PubMed

Cosmos caudatus, which is known as "Ulam Raja," is an herbal plant used in Malaysia to enhance vitality. This study focused on the evaluation of the ?-glucosidase inhibitory activity of different ethanolic extracts of C. caudatus. Six series of samples extracted with water, 20%, 40%, 60%, 80%, and 100% ethanol (EtOH) were employed. Gas chromatography-mass spectrometry (GC-MS) and orthogonal partial least-squares (OPLS) analysis was used to correlate bioactivity of different extracts to different metabolite profiles of C. caudatus. The obtained OPLS scores indicated a distinct and remarkable separation into 6 clusters, which were indicative of the 6 different ethanol concentrations. GC-MS can be integrated with multivariate data analysis to identify compounds that inhibit ?-glucosidase activity. In addition, catechin, ?-linolenic acid, ?-D-glucopyranoside, and vitamin E compounds were identified and indicate the potential ?-glucosidase inhibitory activity of this herb. PMID:24888400

Javadi, Neda; Abas, Faridah; Hamid, Azizah Abd; Simoh, Sanimah; Shaari, Khozirah; Ismail, Intan Safinar; Mediani, Ahmed; Khatib, Alfi

2014-06-01

439

Inhibitory effects of cyclosporin A preceded lymphocyte activation  

SciTech Connect

The cellular mechanism of immunosuppression by cyclosporin A (CYA) is poorly understood. We have examined the effects of CYA on ConA induced T-cell blastogenesis using rabbit PBL's. CYA inhibited mitogenic proliferation in the concentration range of 0.5 to 20 ng/ml without toxicity. CYA was not inhibitory when added hours after lectin addition. CYA did not delay entry into G/sub 2//M phase of mitosis and did not appear cell cycle dependent. Preincubation of cells with CYA for 1 hr at 37/sup 0/ followed by drug removal and cultivation in a drug-free mitogen assay demonstrated proliferative inhibition equal to that of cells cultured in the continued presence of CYA. This suggest that CYA effects preceded lymphocyte activation which interferes with subsequent cellular commitment to blastogenesis. The ability to respond to ConA was not restored by incubation of previously CYAtreated cells in the absence of CYA. To determine if CYA competed with ConA binding to surface receptors, the kinetics of blastogenesis for cells cultured in ConA and CYA were compared to cells cultured in ConA and methyl mannoside (competitive inhibitor of ConA). CYA did not demonstrate competitive inhibition. Surface binding and endocytosis of /sup 125/I-ConA were unaffected by the presence of mitogenically inhibitive dosages of CYA. The results indicate that CYA inhibits ConA induced blastogenesis by an action preceding ConA binding or lymphocyte activation.

Kimball, P.M.; Gamaz-Gottlieb, N.; Sell, S.

1986-03-01

440

Inhibitory effect of resveratrol against duck enteritis virus in vitro.  

PubMed

Duck viral enteritis (DVE) is an acute, contagious herpesvirus infection of ducks, geese, and swans of all ages and species. This disease has been responsible for significant economic losses in domestic and wild waterfowl as a result of mortality, and decreased egg production. Resveratrol is a naturally occurring phytoalexin in specific plants and exhibits inhibitory activity against many kinds of virus. In this paper, resveratrol was found to inhibit duck enteritis virus (DEV) replication in a dose-dependent manner, with a 50% inhibition concentration of 3.85 ?g/mL. The inhibition in virus multiplication in the presence of resveratrol was not attributed to direct inactivation or inhibition of virus attachment to the host cells, but to the inhibition of viral multiplication in host cells. The assay of the time of addition limited the drug effect during the first 8 h of infection. This conclusion was supported by the ultrastructure images of the early stage of DEV infection, which showed that the replication of virus nucleic acid and the formation of the capsid in the cell nucleus were suppressed. In the indirect immunofluorescence assay, proteins expression in DEV infected duck embryo fibroblasts (DEFs) within 24 h post-infection (p.i.) was also effectively suppressed by resveratrol. In summary, the resveratrol has a good activity against DEV infection in vitro, which could be attributed to that fact that several essential immediate early viral proteins for virus replication were impacted by resveratrol. PMID:23776451

Xu, Jiao; Yin, Zhongqiong; Li, Li; Cheng, Anchun; Jia, Renyong; Song, Xu; Lu, Hongke; Dai, Shujun; Lv, Cheng; Liang, Xiaoxia; He, Changliang; Zhao, Ling; Su, Gang; Ye, Gang; Shi, Fei

2013-01-01

441

Kinetics of inhibitory effect of isoferulic acid on mushroom tyrosinase.  

PubMed

A study on the kinetics of inhibitory effect of isoferulic acid on the monophenolase and diphenolase activity of mushroom tyrosinase was carried out using enzymological kinetic analysis method in a Na2HPO4-NaH2PO4 buffer solution (pH = 6.8) at 30°C. It was found that isoferulic acid efficiently inhibits both monophenolase and diphenolase activities of mushroom tyrosinase under experimental conditions.