Distribution by Scientific Domains

Kinds of Pp

  • neat pp
  • pure pp

  • Terms modified by Pp

  • pp composite
  • pp film
  • pp matrix
  • pp nanocomposite
  • pp phase
  • pp sample

  • Selected Abstracts

    A pulse programmer for nuclear magnetic resonance spectrometers

    C.C. Odebrecht
    Abstract A pulse programmer (PP) designed to control a nuclear magnetic resonance (NMR) spectrometer is reported on. The heart of the PP is a computer programmable logic device (CPDL) that provides flexibility to the design and, at the same time, reduces the number of electronics components needed and the dimensions of the printed circuit board. The PP works as follow: first, a pulse sequence defined by a set of instructions is loaded into the RAM memory of the PP. Then, when the process is started, the instructions are, one by one, read, decoded, and executed. Four types of instructions (functions) were defined: PRINT A, PRINT B, WAIT, and STOP. PRINT A and PRINT B change the status of the output channels A and B, respectively, WAIT generates a time delay, and STOP terminates the sequence. The output ports A and B have 14 channels each, and the shortest pulse and resolution are both 200 ns. The design of the PP is versatile, and new functions can be added through software without modifying the printed circuit board. To control the PP from a personal computer, a program named PulseJr was developed. It contains a graphical user interface (GUI) and pulse sequences can be drawn on the monitor screen with the mouse of the computer. Once the pulse sequence is sketched, clicking a button the program compiles the pulse sequence, generates the set of instructions, loads them into the RAM memory of the PP, and starts the pulse sequence. © 2007 Wiley Periodicals, Inc. Concepts Magn Reson Part A 30A: 127,131, 2007. [source]

    Adenosine A1 receptors and vascular reactivity

    ACTA PHYSIOLOGICA, Issue 2 2010
    Y. Wang
    Abstract Aim:, Blood pressure is higher in A1 receptor knock-out (A1R,/,) mice than in wild type litter mates (A1R+/+) and we have examined if this could be related to altered vascular functions. Methods:, Contraction of aortic rings and mesenteric arteries were examined. To examine if the adenosine A1 receptor-mediated contraction of aortic muscle was functionally important we examined pulse pressure (PP) and augmentation index (AIX) using a sensor that allows measurements of rapid pressure transients. Results:, Contraction of aortic rings to phenylephrine and relaxation to acetylcholine were similar between genotypes. The non-selective adenosine receptor agonist N -ethyl carboxamido adenosine (NECA) enhanced the contractile response, and this was eliminated in aortas from A1R,/, mice. However, in mesenteric arteries no contractile response was seen and adenosine-mediated relaxation was identical between studied genotypes. A2B adenosine receptors, rather than A2A receptors, may be mainly responsible for the vasorelaxation induced by adenosine analogues in the examined mouse vessels. PP was higher in A1R,/, mice, but variability was unaltered. AIX was not different between genotypes, but the NECA-induced fall was larger in A1R,/, mice. Conclusions:, The role of adenosine A1 receptors in regulating vessel tone differs between blood vessels. Furthermore, contractile effects on isolated vessels cannot explain the blood pressure in A1 knock-out mice. The A1 receptor modulation of blood pressure is therefore mainly related to extravascular factors. [source]

    Epidemiologic Analysis of Factors Associated with Local Disappearances of Native Ranid Frogs in Arizona

    análisis de factores de riesgo; declinación de anfibios; declinación de ranas; epidemiología de vida silvestre; métodos de control de casos Abstract:,We examined factors that may independently or synergistically contribute to amphibian population declines. We used epidemiologic case,control methodology to sample and analyze a large database developed and maintained by the Arizona Game and Fish Department that describes historical and currently known ranid frog localities in Arizona, U.S.A. Sites with historical documentation of target ranid species (n= 324) were evaluated to identify locations where frogs had disappeared during the study period (case sites) and locations where frog populations persisted (control sites). Between 1986 and 2003, 117 (36%) of the 324 sites became case sites, of which 105 were used in the analyses. An equal number of control sites were sampled to control for the effects of time. Risk factors, or predictor variables, were defined from environmental data summarized during site surveys and geographic information system data layers. We evaluated risk factors with univariate and multifactorial logistic-regression analyses to derive odds ratios (OR). Odds for local population disappearance were significantly related to 4 factors in the multifactorial model. Disappearance of frog populations increased with increasing elevation (OR = 2.7 for every 500 m, p < 0.01). Sites where disappearances occurred were 4.3 times more likely to have other nearby sites that also experienced disappearances (OR = 4.3, p < 0.01), whereas the odds of disappearance were 6.7 times less (OR = 0.15, p < 0.01) when there was a source population nearby. Sites with disappearances were 2.6 times more likely to have introduced crayfish than were control sites (OR = 2.6, p= 0.04). The identification of factors associated with frog disappearances increases understanding of declines occurring in natural populations and aids in conservation efforts to reestablish and protect native ranids by identifying and prioritizing implicated threats. Resumen:,Examinamos los factores que pueden contribuir independiente o sinérgicamente a la declinación de poblaciones de anfibios. Utilizamos una metodología epidemiológica de control de casos para muestrear y analizar una base de datos desarrollada y mantenida por el Departamento de Caza y Pesca de Arizona que describe las localidades históricas y actuales de ranas en Arizona, E. U. A. Los sitios con documentación histórica de las especies de ránidos (n= 324) fueron evaluados para identificar localidades donde las ranas desaparecieron durante el período de estudio (sitios caso) y localidades donde las poblaciones de ranas persistieron (sitios control). Entre 1986 y 2003, 36% (117) de los 324 sitios se volvieron sitios caso, de los cuales 105 fueron utilizados en los análisis. El mismo número de sitios control fueron muestreados para controlar los efectos del tiempo. Los factores de riesgo, o variables predictivas, fueron definidos a partir de datos ambientales obtenidos de los muestreos en los sitios y de capas de datos de un sistema información geográfica. Evaluamos los factores de riesgo con análisis de regresión logística univariada y multivariada para derivar proporciones de probabilidades (PP). Las probabilidad para la desaparición de una población local estuvo relacionada significativamente con 4 factores en el modelo multifactorial. La desaparición de poblaciones de ranas incrementó con la elevación (PP = 2.7 por cada 500 m, p < 0.01). Los sitios donde ocurrieron las desapariciones fueron 4.3 veces más propensos a estar cerca de otros sitios donde ocurrieron desapariciones (PP = 4.3, p < 0.01), mientras que la probabilidad de desaparición fue 6.7 veces menos (PP = 0.15, p < 0.01) cuando había una población fuente cercana. Los sitios con desapariciones fueron 2.6 veces más propensos a tener langostinos introducidos que los sitios control (PP = 2.6, p= 0.04). La identificación de factores asociados con la desaparición de ranas incrementa el conocimiento de las declinaciones de poblaciones naturales y ayuda a los esfuerzos de conservación para el reestablecimiento y la protección de ránidos nativos mediante la identificación y priorización de las amenazas implicadas. [source]

    Photodynamic Therapy of Cutaneous Lymphoma Using 5-Aminolevulinic Acid Topical Application

    Arie Orenstein MD
    Background. Photodynamic therapy (PDT) with topical application of 5-aminolevulinic acid (ALA) is a new and effective modality for treatment of superficial basal and squamous cell carcinomas. Objective. We present the kinetics of ALA-induced protoporphyrin IX (PP) accumulation and the results of ALA PDT treatment on two patients with different stages (stage I and stage III) of mycosis fungoides (MF)-type cutaneous T-cell lymphoma (CTCL). Methods. ALA-Decoderm cream was applied to the lesions for 16 hours. Spectrofluorescence measurements of PP accumulation were carried out before, during, and 1 hour after photoirradiation (580,720 nm) using the VersaLight system. Results. Different patterns of PP fluorescence kinetics were observed in patients with early and advanced stages of the disease. During photoirradiation the intensity of fluorescence decreased depending on the lesion thickness. One hour after the photoirradiation procedure no PP fluorescence was observed in the stage I MF lesion, while in the thick stage III MF lesions, PP fluorescence reappeared; after an additional 10,15 minutes of irradiation PP fluorescence disappeared. Complete response with excellent cosmetic results was observed in the stage I lesion after a single irradiation with a light dose of 170 J/cm2; in five stage III lesions, complete response was achieved after fractionated irradiation with a total light dose of 380 J/cm2 (follow-up at 27 and 24 months, respectively). Conclusion. The results showed a high response of both stage I and stage III MF lesions to ALA PDT. This modality appears to be very effective and can be used successfully for MF treatment. [source]

    Moxonidine improves glycaemic control in mildly hypertensive, overweight patients: a comparison with metformin

    Irina Chazova
    Aim:, To compare the effects of moxonidine and metformin on glycaemic control in patients with impaired glucose tolerance and signs of the metabolic syndrome. Methods:, A multicentre, prospective, randomized, open-label study design was adopted with blinded endpoint evaluation. Patients ,40 years old, with impaired glucose tolerance (or diabetes mellitus treated with diet alone) and a body mass index (BMI) of at least 27 kg/m2 were treated twice daily with moxonidine 0.2 mg or metformin 500 mg for 16 weeks. Oral glucose tolerance test (OGTT) was performed at baseline and end-of-study; plasma insulin and plasma glucose levels were measured at 0, 60, 120 and 180 min after administration. Results:, With regard to effects on insulin [mean area under the curve (AUC) for insulin], the primary efficacy endpoint of the study, both drugs did not show equivalence. On the contrary, in the per protocol (PP) population, moxonidine statistically significantly (p = 0.025) decreased the AUC for insulin from baseline in the PP population; for metformin, the treatment effect on insulin was a small, net increase resulting in a statistically significant between-group difference of 16.2% (95% CI = 0.1,35.0). The change in mean insulin AUC was most marked in the subgroup of patients with higher sympathetic activity (heart rate >80 bpm). Mean fasting plasma glucose (FPG) levels and HbA1c levels were largely unchanged by moxonidine treatment but significantly decreased by metformin treatment. The difference between the groups was 14.7% (p = 0.0523) in the intent-to-treat (ITT) sample. By study end, both treatments had significantly increased the Matsuda Insulin Sensitivity Index (ISI) from baseline to a comparable extent: moxonidine by reducing plasma insulin after a glucose challenge, metformin by reducing FPG. BMI fell significantly in both groups and blood pressure normalized; both drugs were well tolerated. Conclusions:, Moxonidine improved insulin sensitivity in response to glucose challenge in patients with evidence of metabolic syndrome. This improvement resulted from a reduction in plasma insulin levels and was most marked in patients with high sympathetic drive at baseline. By enhancing insulin sensitivity, moxonidine treatment may help prevent the development of diabetes and thereby ameliorate the risk for cardiovascular disease. [source]

    Pulse pressure and mortality in hypertensive type 2 diabetic patients.

    A cohort study
    Abstract Hypothesis Hypertension is a well-known cardiovascular risk factor in type 2 diabetic patients. It has been suggested that pulse pressure (PP) could be an independent cardiovascular risk factor in the general population, particularly in the elderly. An association between office PP and cardiovascular mortality has been previously reported in diabetic patients, while the relationship between ambulatory measurements of PP and all-cause mortality has not been assessed so far. Aim To assess the relationship between ambulatory PP and all-cause mortality in diabetic patients with hypertension. Methods A cohort study was performed on a consecutive series of 435 diabetic outpatients. All patients underwent office blood pressure measurement (OBP) and 24-h ambulatory blood pressure monitoring (ABPM). Mortality was assessed through queries at the Registry Offices of the city of residence for each patient. Mean follow-up was 3.8 ± 1.2 years. Results Fifty-eight patients (13.3%) died during the follow-up. Mortality was significantly (p < 0.05) higher in patients in the highest quartile and lower in patients in the lowest quartile, when compared to the intermediate quartiles, both for office and ABPM-PP. In a multivariate analysis, after adjustment for numerous variables (including current hypoglycaemic, antihypertensive statin and aspirin treatment), mortality was increased by 3.1 and 5.3% for each incremental mmHg of office PP (p < 0.05) and ABPM-PP (p < 0.001) respectively. Conclusions High PP, assessed through office measurement or ABPM, was associated with increased mortality in hypertensive type 2 diabetic patients. In our sample, PP assessed with ABPM is a better predictor of mortality than office PP. Copyright © 2005 John Wiley & Sons, Ltd. [source]

    Diabetes Care Protocol: effects on patient-important outcomes.

    DIABETIC MEDICINE, Issue 4 2010
    A cluster randomized, non-inferiority trial in primary care
    Diabet. Med. 27, 442,450 (2010) Abstract Aims, The Diabetes Care Protocol (DCP) combines task delegation, intensification of diabetes treatment and feedback. It reduces cardiovascular risk in Type 2 diabetes (T2DM) patients. This study determines the effects of DCP on patient-important outcomes. Methods, A cluster randomized, non-inferiority trial, by self-administered questionnaires in 55 Dutch primary care practices: 26 practices DCP (1699 patients), 26 usual care (1692 patients). T2DM patients treated by their general practitioner were included. Main outcome was the 1-year between-group difference in Diabetes Health Profile (DHP-18) total score. Secondary outcomes: DHP-18 subscales, general perceived health [Medical Outcomes Study 36-Items Short Form Health Survey (SF-36), Euroqol 5 Dimensions (EQ-5D) and Euroqol visual analogue scale (EQ-VAS)], treatment satisfaction (Diabetes Treatment Satisfaction Questionnaire; DTSQ status) and psychosocial self-efficacy (Diabetes Empowerment Scale Short Form; DES-SF). Per protocol (PP) and intention-to-treat (ITT) analyses were performed: non-inferiority margin , = ,2%. At baseline 2333 questionnaires were returned and 1437 1 year thereafter. Results, Comparing DCP with usual care, DHP-18 total score was non-inferior: PP ,0.88 (95% CI ,1.94 to 0.12), ITT ,0.439 (95% CI ,1.01 to 0.08), SF-36 ,health change' improved: PP 3.51 (95% CI 1.23 to 5.82), ITT 1.91 (95% CI 0.62 to 3.23), SF-36 ,social functioning' was inconclusive: PP ,1.57 (95% CI ,4.3 to 0.72), ITT ,1.031 (95% CI ,2.52 to ,0.25). Other DHP and SF-36 scores were inconsistent or non-inferior. DHP-18 ,disinhibited eating' was significantly worse in PP analyses. For EQ-5D/EQ-VAS, DTSQ and DES-SF, no significant between-group differences were found. Conclusion, DCP does not seem to influence health status negatively, therefore diabetes care providers should not shrink from intensified treatment. However, they should take possible detrimental effects on ,social functioning' and ,disinhibited eating' into account. [source]

    Ethnic differences in plantar pressures in diabetic patients with peripheral neuropathy

    DIABETIC MEDICINE, Issue 4 2008
    M. P. Solano
    Abstract Aims To compare plantar foot pressures between Caucasian and Hispanic diabetic patients with peripheral neuropathy (PN) without a history of foot ulceration and between Caucasian and Hispanic non-diabetic individuals. Methods Forty-four Hispanic diabetic patients with PN (HDPN), 35 Caucasian diabetic patients with PN (CDPN), 41 non-diabetic Hispanic subjects and 33 non-diabetic Caucasian subjects participated. Total and regional peak plantar pressures (PPs) and pressure time integrals (PTIs) were assessed using the EMED-SF-4 plantar pressure system. Results Hispanic diabetic patients with PN had significantly lower peak PP than Caucasian diabetic patients with PN in the entire foot (552.4 ± 227.9 vs. 810.1 ± 274.6 kPa; P < 0.001), forefoot (464.1 ± 222.6 vs. 699.6 ± 323.1 kPa; P < 0.001), hindfoot (296.3.4 + 101.8 vs. 398.1 + 178.3 kPa; P < 0.01) and at the fifth metatarsal head (MTH5; 204.3 ± 143.2 vs. 388.2 ± 273.9 kPa; P < 0.001). The PTI in the entire foot, forefoot and MTH5 were also lower in HDPN than in CDPN. The ethnic differences between the diabetic groups with PN for the entire foot, forefoot and MTH5 remained significant after adjusting for the effect of age, gender, weight and duration of diabetes. There were no significant differences in peak PP and PTI among non-diabetic individuals, except for a lower peak PP at the MTH5 in Hispanic compared with Caucasian subjects. Conclusions Despite a well-known higher incidence of foot complications in diabetic Hispanic subjects, dynamic plantar pressures are lower in Hispanic diabetic patients with PN when compared with their Caucasian counterparts, suggesting that differences in other risk factors exist between these two ethnic groups. [source]

    PP 7/94(1): Hirschmanniella spp.

    EPPO BULLETIN, Issue 3 2009
    Article first published online: 27 NOV 200
    Specific scope This standard describes a diagnostic protocol for the genus Hirschmanniella1. Specific approval and amendment Approved in 2009,09. [source]

    Novel tumor necrosis factor-knockout mice that lack Peyer's patches

    Abstract We generated a novel tumor necrosis factor (TNF) null mutation using Cre-loxP technology. Mice homozygous for this mutation differ from their "conventional" counterparts; in particular, they completely lack Peyer's patches (PP) but retain all lymph nodes. Our analysis of these novel TNF-knockout mice supports the previously disputed notion of the involvement of TNF-TNFR1 signaling in PP organogenesis. Availability of TNF-knockout strains both with and without PP enables more definitive studies concerning the roles of TNF and PP in various immune functions and disease conditions. Here, we report that systemic ablation of TNF, but not the presence of PP per se, is critical for protection against intestinal Listeria infection in mice. [source]

    Chiral Half-Sandwich Ruthenium(II) Complexes as Catalysts in 1,3-Dipolar Cycloaddition Reactions of Nitrones with Methacrolein,

    Daniel Carmona
    Abstract Ruthenium complexes of formula [(,6 -arene)Ru(LL*)(H2O)][SbF6]2 (arene = C6H6, p -MeC6H4iPr, C6Me6; LL* = bidentate chelate chiral ligand with PN, PP or NN donor atoms) have been tested as catalyst precursors for the asymmetric 1,3-dipolar cycloaddition of nitrones to methacrolein. The reaction occurs quantitatively with perfect endo selectivity and moderate enantioselectivity (up to 74,% ee). The ruthenium aqua complexes can be prepared from the corresponding chlorides, [(,6 -arene)RuCl(LL*)][SbF6]. Dipolarophile intermediates [(,6 -arene)Ru(PNiPr)(methacrolein)][SbF6]2 {PNiPr = (4S)-2-(2-diphenylphosphanylphenyl)-4-isopropyl-1,3-oxazoline} as well as nitrone-containing complexes [(p -MeC6H4iPr)Ru(PNiPr)(nitrone)][SbF6]2 (nitrone = N -benzylidenephenylamine N -oxide, N -benzylidenemethylamine N -oxide, 3,4-dihydroisoquinoline N -oxide) have been also isolated and characterised. The crystal structures of the chlorides (RRu)-[(,6 -C6Me6)RuCl(PNiPr)][SbF6], (RRu)-[(,6 -C6H6)RuCl(PNInd)][SbF6] {PNInd = (3aR,8aS)-2-[2-(diphenylphosphanyl)phenyl]-3a,8a-dihydroindane[1,2- d]oxazole} and those of the aqua solvates (RRu)-[(,6 -arene)Ru(PNiPr)(H2O)][SbF6]2 (arene = C6H6, C6Me6) were determined by X-ray diffraction methods. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006) [source]

    Natural polyphenols as chain-breaking antioxidants during methyl linoleate peroxidation

    Ivan Tichonov
    Abstract A technique based on monitoring oxygen consumption was applied to study 11 natural and model polyphenols (PP, QH2) as well as four typical monophenolics as a chain-breaking antioxidant during the controlled chain oxidation of methyl linoleate (ML) in bulk at 37°C. The antioxidant activities of QH2 were characterized by two parameters: the rate constant k1 for reaction of QH2 with the peroxy radical : (i) QH2,+,,,,,+,LOOH and the stoichiometric factor of inhibition, f, which shows how many kinetic chains may be terminated by one molecule of QH2. The rate constant k1 were reduced significantly by factor of 4 ,28 as compared to these determined during the oxidation of styrene in bulk; the effect was typically more pronounced for catechol derivatives than for pyrogallol derivatives. At the same time, f for QH2 was found to be close to two independent of the number of active OH groups, similar to that determined earlier during the inhibited oxidation of styrene. The formation of H bond between OH group of QH2 and carboxyl group of ML is suggested as a reason for reducing effect of ML on k1. Practical applications: This work reports rate constants for the reaction of lipid peroxyl radical with phenolics and stoichiometric coefficient of inhibition, which characterize the antioxidant activity (AOA) of 15 natural and model PP, QH2 during the controlled peroxidation of ML. The reactivity of PP, QH2 during the oxidation of ML is routinely lower than the reactivity during the oxidation of non-polar model hydrocarbons. This information may be useful to estimate the AOA of natural PP, QH2 in real systems of practical significance including plant oils, fats, food-stuffs, biological objects, and similar. [source]

    The effect of polymers and surfactants on the pour point of palm oil methyl esters

    Cheah Han Sern
    Abstract The objective of this research was to find some additives suitable to reduce the pour point (PP) of palm oil methyl esters. The PP properties of palm oil methyl esters (biodiesel) were evaluated with commercially available polymeric and surfactant compounds with various polarities, molecular sizes and structures. The compounds under study were poly(ethylene glycol), poly(methyl methacrylate), poly(ethylene-co-vinyl acetate), poly(styrene-co-maleic anhydride), poly(ethylene glycol) distearate, poly-(octadecyl methacrylate), poly(1-decene), poly(maleic anhydride- alt -1-octadecene), caprylic acid sodium salt, N -lauroylsarcosine sodium salt, polyoxyethylene(2) cetyl ether and polyoxyethylene(10) cetyl ether. Seven out of the twelve polymeric compounds tested were miscible in palm oil methyl esters due to similar polarities of the solute and biodiesel. The blends of the resultant seven polymeric compounds in palm oil methyl esters were evaluated respectively for their effect on the PP property. Poly-(maleic anhydride- alt -1-octadecene) was able to improve the PP of palm oil methyl esters from 12 to 6,°C when 2,wt-% was added. The cloud point was reduced from 12.9 to 8.1,°C, and the cold filter plugging point was reduced from 12 to 7,°C, whilst the flash point value remained unchanged at 156,°C when 2,wt-% of poly(maleic anhydride- alt -1-octadecene) was added to the palm oil methyl esters. [source]

    Concurrent action observation modulates practice-induced motor memory formation

    K. Stefan
    Abstract Motor practice is associated with the formation of elementary motor memories. Here we tested in human subjects the hypothesis that observation of a motor training associated with physical practice will modulate the encoding process of a motor memory relative to physical practice alone. Voluntary thumb motions were practiced (i) alone in a direction opposite to the baseline direction of transcranial magnetic stimulation (TMS)-evoked movements (physical practice, PP) and in combination with observation of synchronous movements that were either (ii) directionally congruent (same direction, PP + AOc) or (iii) non-congruent (opposite direction, PP + AOnc) to the practiced ones. We evaluated the following measures of motor memory formation: percentage of TMS-evoked thumb movements falling in the direction of practiced motions, acceleration of TMS-evoked movements along the principal movement axis and corticomuscular excitability of training muscles as indexed by motor-evoked potential amplitudes. Both PP and PP + AOc, but not PP + AOnc, significantly increased the percentage of TMS-evoked movements falling in the practiced direction, changed the compound acceleration vector into the trained direction and enhanced the motor-evoked potential amplitudes in the training agonist muscle. The percentage of TMS-evoked movements falling in the practiced direction increased significantly more after PP + AOc than after PP. Across all measures of motor memory formation, PP + AOc was most efficacious, followed by PP and PP + AOnc. Action observation modulates practice effects on formation of a motor memory. Strengthening of the process of motor memory encoding depends on the directional congruency of the observed model. [source]

    Polymorphisms located in the region containing BHMT and BHMT2 genes as maternal protective factors for orofacial clefts

    Adrianna Mostowska
    Mostowska A, Hozyasz KK, Biedziak B, Misiak J, Jagodzinski PP. Polymorphisms located in the region containingBHMTandBHMT2genes as maternal protective factors for orofacial clefts. Eur J Oral Sci 2010; 118: 325,332. © 2010 The Authors. Journal compilation © 2010 Eur J Oral Sci Nonsyndromic cleft lip with or without cleft palate (NCL/P) is one of the most common craniofacial malformations; however, its aetiology is still unclear. Because the effects of maternal nutrition on fetal development are well known, we decided to pursue the question of whether polymorphic variants of genes encoding enzymes involved in choline metabolism might be associated with the maternal risk of having a baby with NCL/P. Analysis of 18 single nucleotide polymorphisms (SNPs) of betaine-homocysteine methyltransferase (BHMT), betaine-homocysteine methyltransferase-2 (BHMT2), choline dehydrogenase (CHDH), choline kinase (CHKA), dimethylglycine dehydrogenase (DMGDH), choline-phosphate cytidylyltransferase A (PCYT1A), and phosphatidylethanolamine N -methyltransferase (PEMT) provided evidence that polymorphisms located in the region containing BHMT and BHMT2 were protective factors against NCL/P affected pregnancies in our population. The strongest signal was found for the SNP located in the intronic sequence of BHMT2. Women carrying two copies of the rs625879 T allele had a significantly decreased risk of having offspring with orofacial clefts. These results were significant, even after correction for multiple comparisons. Moreover, the gene,gene interaction analysis revealed a significant epistatic interaction of BHMT2 (rs673752), PEMT (rs12325817), and PCYT1A (rs712012) with maternal NCL/P susceptibility. Altogether, our study identified a novel gene, the nucleotide variants of which were be associated with a decreased risk of having a baby with NCL/P. [source]

    Issue salience in regional party manifestos in Spain

    It is based on a content analysis of the party manifestos of the Spanish PP and PSOE in eight regional elections held between 2001 and 2003. It provides an innovative coding scheme for analysing regional party manifestos and on that basis seeks to account for inter-regional, intra-party and inter-party differences in regional campaigning. The authors have tried to explain the inter-regional variation of the issue profiles of state-wide parties in regional elections on the basis of a model with four independent variables: the asymmetric nature of the system, the electoral cycle, the regional party systems and the organisation of the state-wide parties. Three of their hypotheses are rejected, but the stronger variations in the regional issue profiles of the PSOE corroborate the assumption that parties with a more decentralised party organisation support regionally more diverse campaigning. The article concludes by offering an alternative explanation for this finding and by suggesting avenues for further research. [source]

    Enhancing the P trapping of pasture filter strips: successes and pitfalls in the use of water supply residue and polyacrylamide

    M. R. Redding
    Summary In intensive pastoral systems the landscape at ground level is clad in dense, filtering vegetation , yet phosphorus losses in overland flow do occur, and pollution of surface waters is a serious consequence. The use of pre-applied polyacrylamide (PAM) or chitosan to trap particulate phosphorus (PP) and P-sorbing potable water treatment alum residue (PWTR) to enhance vegetative filtering effects is examined here using field and laboratory overland flow simulation (flows from 0.43 to 0.34 litres s,1 (m width),1) and analysis. Fitted equations suggest that up to 40% of dissolved reactive P applied (0.75 mg P litre,1) in overland flow could be captured in a flow length of 2.1 m (1 kg PWTR m,2). Unfortunately, drying decreased PWTR effectiveness, though little of the P captured was readily desorbed. This effect did not appear to be the result of gibbsite formation. Compared with the other treatments, there was a strong treatment effect of pre-applied PAM on the change in PP losses (P < 0.001) over time, though evidence suggests the PAM effect declined during a 44 minute flow period. We showed that the investigated two-pronged approach to the enhancement of the effectiveness of P trapping by pasture had limitations. Laboratory sheet-flow simulations suggest that a field-stable P sorber with sorption characteristics similar to those of the un-dried PWTR could be an effective retention enhancer for dissolved P. Pre-applied PAM can have an effect on particulate-P trapping but was rapidly dissolved and removed by flow. [source]

    Fate of airborne metal pollution in soils as related to agricultural management.


    Summary The fate of airborne metal pollutants in soils is still relatively unknown. We studied the incorporation of such airborne metal pollution in two soils under long-term permanent pasture (PP) and conventional arable land (CA). Both soils were located at an almost equal distance from a former zinc smelter complex and developed under comparable pedogenetic conditions. Profiles of total concentrations of Zn, chosen as a mobile, and Pb as a little- or non-mobile element, were examined and compared with macro- and micromorphological soil characteristics (soil colour, biological activity). The two soils showed different profiles of total Zn and Pb concentrations, with a marked decrease of concentrations of both elements under the plough layer in CA, whereas the decrease was more progressive in PP. However, the stocks of Zn and Pb for the 1-m soil profiles of CA and PP were comparable. Correlation of Zn and Pb concentration at different depths with total Fe contents and comparison with estimated data for the local geochemical background (LGCB), suggests transport of Zn from the surface to depth in CA and PP, and Pb movement in PP. In CA, 53% of Zn and 92.5% of Pb stocks derived from airborne metal pollution were located at depths < 26 cm. In PP, only 40% of Zn and 82% of Pb, derived from airborne pollution, were found in the A11 and A12 horizons (< 26 cm), the remaining 18% of the Pb stock being incorporated until 50 cm depth; one-third of total Zn stock ascribed to airborne pollution was found at depths > 50 cm. Studies of the composition of gravitational water collected in soils from the same study area suggest two mechanisms for metal movement. First, mobile metal ions (Zn2+) move in the soil solution and are intercepted by iron-clay complexes in deeper soil horizons. Second, observed only in PP, simultaneous movement of Zn and Pb is ascribed to bioturbation by earthworms. [source]

    Delay analysis of a probabilistic priority discipline

    Yuming Jiang
    In computer networks, the Strict Priority (SP) discipline is perhaps the most common and simplest method to schedule packets from different classes of applications, each with diverse performance requirements. With this discipline, however, packets at higher priority levels can starve packets at lower priority levels. To resolve this starvation problem, we propose to assign a parameter to each priority queue in the SP discipline. The assigned parameter determines the probability or extent by which its corresponding queue is served when the queue is polled by the server. We thus form a new packet service discipline, referred to as the Probabilistic Priority (PP) discipline. By properly adjusting the assigned parameters, not only is the performance of higher priority classes satisfied, but also the performance of lower priority classes can be improved. This paper analyzes the delay performance of the PP discipline. A decomposition approach is proposed for calculating the average waiting times and their bounds are studied. Two approximation approaches are proposed to estimate the waiting times. Simulation results that validate the numerical analysis are presented and examined. A numerical example which demonstrates the use of the PP discipline to achieve service differentiation is presented. This example also shows how the assigned parameters can be determined from the results of analysis mentioned above. [source]

    Two-thumb vs Two-finger Chest Compression in an Infant Model of Prolonged Cardiopulmonary Resuscitation

    Michele L. Dorfsman MD
    Abstract. Objective: Previous experiments in the authors swine lab have shown that cardiopulmonary resuscitation (CPR) using two-thumb chest compression with a thoracic squeeze (TT) produces higher blood and perfusion pressures when compared with the American Heart Association (AHA)-recommended two-finger (TF) technique. Previous studies were of short duration (1-2 minutes). The hypothesis was that TT would be superior to TF during prolonged CPR in an infant model. Methods: This was a prospective, randomized crossover experiment in a laboratory setting. Twenty-one AHA-certified rescuers performed basic CPR for two 10-minute periods, one with TT and the other with TF. Trials were separated by 2-14 days, and the order was randomly assigned. The experimental circuit consisted of a modified manikin with a fixed-volume arterial system attached to a neonatal monitor via an arterial pressure transducer. The arterial circuit was composed of a 50-mL bag of normal saline solution (air removed) attached to the manikin chest plate and connected to the transducer with a 20-gauge intravenous catheter and tubing. Rescuers were blinded to the arterial pressure tracing. Systolic blood pressure (SBP), diastolic blood pressure (DBP), and mean arterial pressure (MAP) were recorded in mm Hg, and pulse pressures (PPs) were calculated. Data were analyzed with two-way repeated-measures analysis of variance. Sphericity assumed modeling, with Greenhouse-Geisser and Huynh-Feldt adjustments, was applied. Results: Marginal means for TT SBP (68.9), DBP (17.6), MAP (35.3), and PP (51.4) were higher than for TF SBP (44.8), DBP (12.5), MAP (23.3), and PP (32.2). All four pressures were significantly different between the two techniques (p , 0.001). Conclusion: In this infant CPR model, TT chest compression produced higher MAP, SBP, DBP, and PP when compared with TF chest compression during a clinically relevant duration of prolonged CPR. [source]

    Role of GABAergic neurones in the nucleus tractus solitarii in modulation of cardiovascular activity

    Jasenka Zubcevic
    GABAergic neurones are interspersed throughout the nucleus tractus solitarii (NTS), and their tonic activity is crucial to the maintenance of cardiorespiratory homeostasis. However, the mechanisms that regulate the magnitiude of GABAergic inhibition in the NTS remain unknown. We hypothesized that the level of GABAergic inhibition is proportionally regulated by the level of excitatory synaptic input to the NTS from baroreceptors. Using the in situ working heart,brainstem preparation in normotensive and spontaneously hypertensive rats, we blocked GABAA receptor-mediated neurotransmission in the NTS with gabazine (a specific GABAA receptor antagonist) at two levels of perfusion pressure (low PP, 60,70 mmHg; and high PP, 105,125 mmHg) while monitoring the immediate changes in cardiorespiratory variables. In normotensive rats, gabazine produced an immediate bradycardia consistent with disinhibition of NTS circuit neurones that regulate heart rate (HR) which was proportional to the level of arterial pressure (,HR at low PP, ,57 ± 9 beats min,1; at high PP, ,177 ± 9 beats min,1; P < 0.001), suggesting that GABAergic circuitry in the NTS modulating heart rate was arterial pressure dependent. In contrast, there was no significant difference in the magnitude of gabazine-induced bradycardia in spontaneously hypertensive rats at low or high PP (,HR at low PP, ,45 ± 10 beats min,1; at high PP, ,58 ± 7 beats min,1). With regard to thoracic sympathetic nerve activity (tSNA), at high PP there was a significant reduction in tSNA during the inspiratory (I) phase of the respiratory cycle, but only in the normotensive rat (,,tSNA =,18.7 ± 10%). At low PP, gabazine caused an elevation of the postinspiration phase of tSNA in both normotensive (,,tSNA = 23.7 ± 2.9%) and hypertensive rats (,,tSNA = 44.2 ± 14%). At low PP, gabazine produced no change in tSNA during the mid-expiration phase in either rat strain, but at high PP we observed a significant reduction in the mid-expiration phase tSNA, but only in the spontaneously hypertensive rat (,,tSNA =,25.2 ± 8%). Gabazine at both low and high PP produced a reduction in the late expiration phase of tSNA in the hypertensive rat (low PP, ,,tSNA =,29.4 ± 4.4%; high PP, ,tSNA =,22.8 ± 3%), whereas in the normotensive rat this was only significant at high PP (,,tSNA =,42.5 ± 6.1%). Therefore, in the spontaneously hypertensive rat, contrary to the GABAA receptor-mediated control of HR, it appears that GABAA receptor-mediated control of tSNA in the NTS is arterial pressure dependent. This study provides new insight into the origin of GABAergic inhibition in NTS circuitry affecting heart rate and sympathetic activity. [source]

    Fire hazard evaluation of thermoplastics based on analytic hierarchy process (AHP) method

    FIRE AND MATERIALS, Issue 5 2010
    Baogang Yu
    Abstract Combustibility performance of 14 compositions including five main thermoplastics (polycarbonate (PC), polypropylene (PP), high impact polystyrene (HIPS), acrylonitrile butadiene styrene (ABS) and poly (vinyl chloride) (PVC)) was tested by cone calorimeter. The fire growth index, total heat release amount index, total smoke release amount index and toxicity product index were calculated, based on which an index system for evaluating fire hazard was set up. All factors in this index system had been analyzed by the analytic hierarchy process, and the specific weight for each factor had been determined. Then fire hazard of thermoplastics was evaluated considering integrated fire hazard index. The results show that fire hazards of HIPS-phosphate fire retardant (PFR), PVC-non-flame retardant, ABS-brominated flame retardant (BFR) and PC/ABS-PFR are higher than PC-BFR and PP-non-halogenated flame retardant. Copyright © 2009 John Wiley & Sons, Ltd. [source]

    Flame retardation and thermal degradation of flame-retarded polypropylene composites containing melamine phosphate and pentaerythritol phosphate

    FIRE AND MATERIALS, Issue 5 2008
    Shun Zhou
    Abstract The flame retardation of polypropylene (PP) composites containing melamine phosphate (MP) and pentaerythritol phosphate (PEPA) was characterized by limiting oxygen index (LOI) and UL 94. The morphology of the char obtained from the combustion of the composites was studied by scanning electron microscopy (SEM). The thermal degradation of the composites was investigated using thermogravimetric (TG) analysis and real-time Fourier transform infrared (RTFTIR) spectroscopy. It has been found that the PP composites containing only MP do not show good flame retardancy even at 40% additive level. Compared with the PP/MP binary composites, all the LOI values of the PP/MP/PEPA ternary composites at the same additive loading increase, and UL 94 ratings of the ternary composites at suitable MP/PEPA ratios are raised to V-0 from no rating (PP/MP). The TG and RTFTIR studies indicate that the interaction occurs among MP, PEPA and PP. Copyright © 2008 John Wiley & Sons, Ltd. [source]

    Cone calorimeter analysis of UL-94 V-rated plastics,

    FIRE AND MATERIALS, Issue 4 2007
    Alexander B. Morgan
    Abstract Cone calorimeter analysis was conducted on 18 thermoplastics with different UL-94 vertical burn test (V) ratings. Ratings varied from V-0 to no rating (NR), and the types of thermoplastics included were polycarbonate (PC), acrylonitrile,butadiene,styrene (ABS), PC/ABS blends, high-impact polystyrene (HIPS), polypropylene (PP), and poly(vinyl chloride) (PVC). Our analysis of the cone calorimeter data found that there were correlations between UL-94 V rating and some cone calorimeter measurements (peak heat release rate (HRR) average and HRR at 60 s) and no relationship for other measurements (time to ignition and total heat release). However, no precise correlation was found due to significant differences in flame retardant mechanism and polymer fuel energy values. In this paper, we seek to explain further why a broad quantitative relationship between UL-94 V and cone calorimeter remains elusive, and also to show how the cone calorimeter can be used to understand why a material passes or fails a particular UL-94 V rating. Copyright © 2006 John Wiley & Sons, Ltd. [source]

    Fluctuations in European eel (Anguilla anguilla) recruitment resulting from environmental changes in the Sargasso Sea

    Abstract European eel decline is now widely observed and involves a large number of factors such as overfishing, pollution, habitat loss, dam construction, river obstruction, parasitism and environmental changes. In the present study, we analyzed the influence of environmental conditions in the Sargasso Sea and Atlantic ocean circulation on European glass eel recruitment success. Over a recent 11-yr period, we showed a strong positive correlation between an original index of glass eel recruitment and primary production (PP) in eel spawning area. Moreover, PP was negatively correlated with temperature in the Sargasso Sea. Therefore, we used sea temperature as an inverse proxy of marine production. A close negative relationship has been found over the last four decades between long-term fluctuations in recruitment and in sea temperature. These findings were reinforced by the detection of a regime shift in sea temperature that preceded the start of the decline in glass eel recruitment in the early 1980s. By contrast, variations in integrative indices measuring ocean circulation, i.e. latitude and strength of the Gulf Stream, did not seem to explain variations in glass eel recruitment. Our results support the hypothesis of a strong bottom-up control of leptocephali survival and growth by PP in the Sargasso Sea on short and long time scales. We argue that sea warming in the eel spawning area since the early 1980s has modified marine production and eventually affected the survival rate of European eels at early life stages. [source]

    Genetic diversity and migration patterns of the aquatic macrophyte Potamogeton malaianus in a potamo-lacustrine system

    FRESHWATER BIOLOGY, Issue 6 2009
    Summary 1.,Previously, the Yangtze River connected thousands of shallow lakes which together formed a potamo-lacustrine system capable of sustaining a rich variety of submerged macrophytes. 2.,Potamogeton malaianus is one of the dominant submerged macrophytes in many lakes of this area. Genetic variation and population structure of P. malaianus populations from ten lakes in the potamo-lacustrine system were assessed using inter-simple sequence repeat markers. 3.,Twelve primer combinations produced a total of 166 unambiguous bands of which 117 (70.5%) were polymorphic. Potamogeton malaianus exhibited a moderate level of population genetic diversity (PP = 70.5%, HE = 0.163 and I = 0.255), as compared with that of plants in the same habitat and range. The main factors responsible for this moderate value were the plant's mixed breeding system (both sexual and asexual) and the hydrological connectivity among habitats. 4.,F statistics, calculated using different approaches, consistently revealed a moderate genetic differentiation among populations, contributing about 20% of total genetic diversity. An estimate of gene flow (using FST) suggested that gene flow played a more important role than genetic drift in the current population genetic structure of P. malaianus (Nm = 1.131). 5.,The genetic diversity of P. malaianus did not increase downstream. A high level of linkage,disequilibrium at the whole population level suggested that metapopulation processes may affect genetic structure. The migration pattern of P. malaianus was best explained by a two-dimensional stepping stone model, indicating that bird-mediated dispersal could greatly influence gene movements among lakes. [source]

    Abundance and production of bacteria, and relationship to phytoplankton production, in a large tropical lake (Lake Tanganyika)

    FRESHWATER BIOLOGY, Issue 6 2009
    Summary 1. Abundance and bacterial production (BP) of heterotrophic bacteria (HBact) were measured in the north and south basins of Lake Tanganyika, East Africa, during seasonal sampling series between 2002 and 2007. The major objective of the study was to assess whether BP can supplement phytoplankton particulate primary production (particulate PP) in the pelagic waters, and whether BP and particulate PP are related in this large lake. HBact were enumerated in the 0,100 m surface layer by epifluorescence microscopy and flow cytometry; BP was quantified using 3H-thymidine incorporation, usually in three mixolimnion layers (0,40, 40,60 and 60,100 m). 2. Flow cytometry allowed three subpopulations to be distinguished: low nucleic acid content bacteria (LNA), high nucleic acid content bacteria (HNA) and Synechococcus -like picocyanobacteria (PCya). The proportion of HNA was on average 67% of total bacterial abundance, and tended to increase with depth. HBact abundance was between 1.2 × 105 and 4.8 × 106 cells mL,1, and was maximal in the 0,40 m layer (i.e. roughly, the euphotic layer). Using a single conversion factor of 15 fg C cell,1, estimated from biovolume measurements, average HBact biomass (integrated over a 100-m water column depth) was 1.89 ± 1.05 g C m,2. 3. Significant differences in BP appeared between seasons, especially in the south basin. The range of BP integrated over the 0,100 m layer was 93,735 mg C m,2 day,1, and overlapped with the range of particulate PP (150,1687 mg C m,2 day,1) measured in the same period of time at the same sites. 4. Depth-integrated BP was significantly correlated to particulate PP and chlorophyll- a, and BP in the euphotic layer was on average 25% of PP. 5. These results suggest that HBact contribute substantially to the particulate organic carbon available to consumers in Lake Tanganyika, and that BP may be sustained by phytoplankton-derived organic carbon in the pelagic waters. [source]

    Effects of experimentally induced cyanobacterial blooms on crustacean zooplankton communities

    FRESHWATER BIOLOGY, Issue 2 2003
    Anas Ghadouani
    SUMMARY 1.,Large in situ enclosures were used to study the effects of experimentally induced cyanobacterial blooms on zooplankton communities. A combination of N and P was added to shallow (2 m) and deep enclosures (5 m) with the goal of reducing the TN : TP ratio to a low level (,5 : 1) to promote cyanobacterial growth. After nutrient additions, high biomass of cyanobacteria developed rapidly in shallow enclosures reaching levels only observed during bloom events in eutrophic lakes. 2.,In the shallow enclosures, particulate phosphorus (PP) was on average 35% higher in comparison with deep enclosures, suggesting that depth plays a key role in P uptake by algae. Phytoplankton communities in both deep and shallow enclosures were dominated by three cyanobacteria species ,Aphanizomenon flos-aquae, Anabaena flos-aquae and Microcystis aeruginosa, which accounted for up to 70% of total phytoplankton biomass. However, the absolute biomass of the three species was much higher in shallow enclosures, especially Aphanizomenon flos-aquae. The three cyanobacteria species responded in contrasting ways to nutrient manipulation because of their different physiology. 3.,Standardised concentrations of the hepatotoxic microcystin-LR increased as a result of nutrient manipulations by a factor of four in the treated enclosures. Increased biomass of inedible and toxin producing cyanobacteria was associated with a decline in Daphnia pulicaria biomass caused by a reduction in the number of individuals with a body length of >1 mm. Zooplankton biomass did not decline at moderate cyanobacteria biomass, but when cyanobacteria reached high biomass large cladocerans were reduced. 4.,Our results demonstrate that zooplankton communities can be negatively affected by cyanobacterial blooms and therefore the potential to use herbivory to reduce algal blooms in such eutrophic lakes appears limited. [source]

    Sex differences in genetic and environmental determinants of pulse pressure

    Katrina J. Scurrah
    Abstract Pulse pressure (PP) is an independent risk factor for cardiovascular disease. PP rises with age, more so in women. We examined sex differences in the correlations and variance components of PP in adult subjects from 767 nuclear families, enriched with those containing twins, from the Victorian Family Heart Study. After adjusting for age, we found no significant differences in the means or variances of PP in males and females. Under the assumption of no sex differences, the proportions of variance due to shared genes, shared environment, and individual-specific environment were 20%, 23% and 57%, respectively. However, same-sex relative pairs had significantly higher correlations than opposite-sex pairs (P=0.005), implying the existence of sex-dependent effects. Extensions to the simple variance components model suggested three possible explanations for these differences: smaller genetic correlation between opposite-sex pairs (,G,MF=0.45, P=0.007); smaller environmental correlation between opposite-sex pairs (P=0.0003); or different environmental and genetic correlations obtained by estimating genetic, environmental, and individual variance components separately for males and females (not nested, Akaike's Information Criterion (AIC) smaller by 6.69). Under the last model, the genetic component of PP variance is greater for males (1.62 vs 0.33) while the environmental component is greater for females (1.84 vs 0), which would have implications for the planning of gene discovery studies, since heritability would be higher in males. However, the second (environmental) approach best fits the data according to the AIC. Genetic explanations for sex differences in phenotypic correlations may be misleading unless shared environmental factors are also considered. PP illustrates a phenotype in which sex dependency represents an important component of phenotypic determination that can be revealed by detailed variance components modelling. Genet. Epidemiol. 2006. © 2006 Wiley-Liss, Inc. [source]

    A reflector at 200 km depth beneath the northwest Pacific

    S. Rost
    SUMMARY We present an analysis of precursors to PP produced by underside reflections from discontinuities in the upper mantle beneath the NW Pacific. The events used for this study occur in the western Pacific Rim (New Zealand, Fiji, Tonga, Solomon, New Guinea, Philippine Islands) and are recorded at the short-period Yellowknife Array (YKA) in northern Canada. The source,receiver combination results in PP reflection points which allow us to study the upper mantle structure in a corridor from the Hawaiian Islands to the Kuril subduction zone. To detect the weak precursors in the time window between the P arrival and the PP onset and to identify them as PP underside reflections, special array techniques are used. Our analysis indicates a reflector at a depth of ,200 km beneath the northwestern Pacific. This reflector shows strong topography of some tens of kilometres on length scales of several hundred kilometres, complicating the detection of this reflector in global or regional stacks of seismograms. Different models for the impedance jump across the reflector, the thickness and the possible fine structure of the reflector are modelled using synthetic seismograms and are compared with the data. The thickness of the reflector has to be less than 7 km and the P wave impedance contrast has to be larger than 5.0,6.5 per cent to be detected by this study. This corresponds to a P -velocity jump of ,4 per cent assuming the PREM density model. [source]