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Clear Correlation (clear + correlation)
Selected AbstractsTemperature responsive pore-filled membranes based on a BSA/poly(N -isopropylacrylamide) hydrogelADVANCES IN POLYMER TECHNOLOGY, Issue 1 2008R. Zhang Abstract A temperature-sensitive hydrogel based on a copolymer of BSA and poly(N -isopropylacrylamide) (PNIPAAm) has been synthesized using carbodiimide chemistry. Fourier transform infrared spectroscopy confirmed primary complex formation between carbodiimide-activated carboxylic acids on the protein with protein amino groups. As a result of temperature-induced conformational changes in PNIPAAm grafted onto the protein backbone, these protein hydrogels show significant morphological changes in response to temperature. The structural changes of the gels in response to temperature were assessed using scanning electron microscopy, and the effect of temperature on their balance of hydrophobicity was found using turbidity measurements. Composite pore-filled membranes formed by impregnating glass fiber filters with the polymer mixture prior to gelation were used to determine permeability changes in response to temperature using both low (riboflavin) and intermediate (lysozyme) molecular weight diffusates. Clear correlation was found between changes in morphology, turbidity, and gel permeability as the gel temperature was increased from 24,37°C. In the case of permeability studies, significant transport of lysozyme only occurred at temperatures above the lower transition temperature of the hydrogel, suggesting the gel was acting as a mechanical "valve" to control flux. © 2008 Wiley Periodicals, Inc. Adv Polym Techn 27:27,34, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/adv.20113 [source] Gate Dielectric Microstructural Control of Pentacene Film Growth Mode and Field-Effect Transistor Performance,ADVANCED MATERIALS, Issue 18 2007C. Kim Organic semiconductor/dielectric interfacial characteristics play a critical role in influencing organic thin-film transistor (OTFT) performance characteristics (see figure). Clear correlations between pentacene film deposition temperature, estimated polymer dielectric surface microstructural mobility, and the corresponding film growth mode, semiconductor phase composition, and carrier mobilities are established. [source] P71 Metabolism of delta-3-Carene by human cytochrom 450 enzymesCONTACT DERMATITIS, Issue 3 2004Mike Duisken Occupational exposure to monoterpenes occurs in saw mills, particle-board plants, carpentry shops and other types of wood-treating industries. The bicyclic monoterpene delta-3-Carene, one of the components of turpentine, may irritate the skin and muceous membranes and prolonged exposure may result in allergic contact dermatitis or chronic lung function impairment. The effects of low concentrations of delta-3-Carene on alveolar macrophages in vitro were examined and a dose-dependent relationship between the cell viability and the delta-3-Carene concentration was found. Little is known about the metabolism of delta-3-Carene in mammalians. In order to determine the toxic potential of this monoterpene we studied the human metabolism of delta-3-Carene in vitro. Therefore we used pooled human liver S9 and human liver microsomal cytochrome P450 enzymes. By using GC-MS analysis we found one main metabolite produced at high rates. The structure was identified by its mass spectra. The mass fragmentation indicated hydroxylation in allyl position. After synthesis of the assumed product in a four step reaction, it was characterized as delta-3-Carene-10-ol. There was a clear correlation between the concentration of the metabolite production, incubation time and enzyme concentration, respectively. Kinetic analysis showed that Km and Vmax values for the oxidation of delta-3-Carene by human liver microsomes were 0.39 ,M and 0.2 nmol/min/nmol P450. It is the first time that delta-3-Carene-10-ol is described as human metabolite of delta-3-Carene. [source] Genetic basis of rett syndromeDEVELOPMENTAL DISABILITIES RESEARCH REVIEW, Issue 2 2002Ignatia B. Van den Veyver Abstract The origin of Rett syndrome has long been debated, but several observations have suggested an X-linked dominant inheritance pattern. We and others have pursued an exclusion-mapping strategy using DNA from a small number of familial Rett syndrome cases. This work resulted in the narrowing of the region likely to harbor the mutated gene to Xq27.3-Xqter. After systematic exclusion of several candidate genes, we discovered mutations in MECP2, the gene that encodes the transcriptional repressor, methyl-CpG-binding protein 2. Since then, nonsense, missense, or frameshift mutations have been found in at least 80% of girls affected with classic Rett syndrome. Sixty-four percent of mutations are recurrent C > T transitions at eight CpG dinucleotides mutation hotspots, while the C-terminal region of the gene is prone to recurrent multinucleotide deletions (11%). Most mutations are predicted to result in total or partial loss of function of MeCP2. There is no clear correlation between the type and position of the mutation and the phenotypic features of classic and variant Rett syndrome patients, and XCI appears to be a major determinant of phenotypic severity. Further research focuses on the pathogenic consequences of these mutations along the hypothesis of loss of transcriptional repression of a small number of genes that are essential for neuronal function in the maturing brain. MRDD Research Reviews 2002;8:82,86. © 2002 Wiley-Liss, Inc. [source] Evaluation of mutant frequencies of chemically induced tumors and normal tissues in ,/cII transgenic miceENVIRONMENTAL AND MOLECULAR MUTAGENESIS, Issue 1 2005Jon C. Mirsalis Abstract Genomic instability has been implicated as an important component in tumor progression. Evaluation of mutant frequencies (MFs) in tumors of transgenic mice containing nontranscribed marker genes should be useful for quantitating mutation rates in tumors as the physiologically inactive transgene provides neither a positive nor a negative selective pressure on the tumor. We have conducted long-term carcinogenicity studies in ,/cII transgenic B6C3F1 mice using a variety of genotoxic and nongenotoxic test agents and have evaluated the mutant frequencies in both tumors and normal tissues from these animals. Mice were administered diethylnitrosamine (DEN) as three intraperitoneal injections of 15 mg/kg; phenobarbital (PB) or oxazepam (OXP) provided ad libitum at 0.1% or 0.25% in the diet, respectively; DEN initiation plus PB in the diet; or urethane (UTH) provided ad libitum at 0.2% in the drinking water. Normal tissues and tumors were isolated at various times over a 2-year period and half of each tissue/tumor was evaluated histopathologically and the other half was evaluated for MF in the cII transgene. Approximately 20 mutants from each of 166 individual tissues (tumor and nontumor) were sequenced to determine whether increases in MF represented unique mutations or were due to clonal expansion. UTH produced significant increases in MF in normal liver and lung. DEN either with or without PB promotion produced significant increases in MF in liver and correction of MF for clonality produced little change in the overall MF in these groups. PB produced a twofold increase in liver MF over controls after 27 weeks of treatment, but a similar increase was not observed with longer dosing times; at later time points, the MF in the PB groups was lower than that of the control group, suggesting that PB is not producing direct DNA damage in the liver. OXP failed to produce an increase in MF over controls, even after 78 weeks of treatment. Selected cases of genomic instability were observed in tumors from all treatments except OXP, with individual liver tumors showing very high MF values even after clonal correction. One rare and interesting finding was noted in a single mouse treated with UTH, where a mammary metastasis had an MF approximately 10-fold greater than the parent tumor, with 75% of the mutations independent, providing strong evidence of genomic instability. There was no clear correlation between tumor phenotype and MF except that pulmonary adenomas generally had higher MFs than normal lung in both genotoxic and nongenotoxic treatment groups. Likewise, there was no correlation between tumor size and MF after correction for clonality. The results presented here demonstrate that individual tumors can show significant genomic instability, with very significant increases in MF that are not attributed to clonal expansion of a single mutant cell. Environ. Mol. Mutagen., 2005. © 2004 Wiley-Liss, Inc. [source] Molecular-feature domains with posterodorsal,anteroventral polarity in the symmetrical sensory maps of the mouse olfactory bulb: mapping of odourant-induced Zif268 expressionEUROPEAN JOURNAL OF NEUROSCIENCE, Issue 10 2002Koichiro Inaki Abstract Individual glomeruli in the mammalian olfactory bulb presumably represent a single type of odourant receptor. Thus, the glomerular sheet provides odourant receptor maps at the surface of the olfactory bulb. To understand the basic spatial organization of the olfactory sensory maps, we first compared the spatial distribution of odourant-induced responses measured by the optical imaging of intrinsic signals with that detected immunohistochemically by expressions of Zif268, one of the immediate early gene products in juxtaglomerular cells. In the dorsal surface of the bulb, we detected a clear correlation in the spatial pattern between these responses. In addition, the molecular-feature domains and their polarities (spatial shifts of responses with an increase in carbon chain length) that were defined by the optical imaging method could be also detected by the Zif268 mapping method. We then mapped the Zif268 signals over the entire olfactory bulb using a homologous series of fatty acids and aliphatic alcohols as stimulus odourants. We superimposed the Zif268 signals onto the standard unrolled map with the help of cell adhesion molecule compartments. Each odourant typically elicited two pairs of clusters of dense Zif268 signals. The results showed that molecular-feature domains and their polarities were arranged symmetrically at stereotypical positions in a mirror-image fashion between the lateral and the medial sensory maps. The polarity of each domain was roughly in parallel with the posterodorsal,anteroventral axis that was defined by the cell adhesion molecule compartments. These results suggest that the molecular-feature domain with its fixed polarity is one of the basic structural units in the spatial organization of the odourant receptor maps in the olfactory bulb. [source] Genomic and phenotypic heterogeneity of Acidithiobacillus spp. strains isolated from diverse habitats in ChinaFEMS MICROBIOLOGY ECOLOGY, Issue 2 2008Yong-Qing Ni Abstract The genetic variability among 32 Chinese Acidithiobacillus spp. environmental isolates and four reference strains representing three recognized species of the genus Acidithiobacillus was characterized by using a combination of molecular methods, namely restriction fragment length polymorphisms of PCR-amplified 16S rRNA genes and 16S,23S rRNA gene intergenic spacers, repetitive element PCR, arbitrarily primed PCR and 16S rRNA gene sequence analyses. 16S rRNA gene sequences revealed that all Acidithiobacillus spp. strains could be assigned to seven groups, three of which encompassed the Acidithiobacillus ferrooxidans strains from various parts of the world. A comparative analysis of the phylogenetic Group 1 and 2 was undertaken. Restriction fragment length polymorphism results allowed us to separate the 35 Acidithiobacillus strains into 15 different genotypes. An integrated phenotypic and genotypic analysis indicated that the distribution of A. ferrooxidans strains among the physiological groups were in agreement with their distribution among the genomic groups, and that no clear correlation was found between the genetic polymorphism of the Acidithiobacillus spp. strains and either the geographic location or type of habitats from which the strains were isolated. In addition, five unidentified sulfur-oxidizing isolates may represent one or two novel species of the genus Acidithiobacillus. The results showed that the Chinese Acidithiobacillus spp. isolates exhibited a high degree of genomic and phenotypic heterogeneity. [source] Defect-Related Emissions and Magnetization Properties of ZnO NanorodsADVANCED FUNCTIONAL MATERIALS, Issue 7 2010Bharati Panigrahy Abstract A clear correlation between defect-related emissions and the magnetization of ZnO nanorods synthesized by a one-step aqueous chemical method is demonstrated. The relative contribution of the emission bands arising from various types of defects is determined and found to be linked with the size of the nanorods and annealing conditions. When the size of the nanorods and the annealing temperature are increased, the magnetization of pure ZnO nanorods decreases with the reduction of a defect-related band originating from singly charged oxygen vacancies (). With a sufficient increase of annealing temperature (at 900,°C), the nanorods show diamagnetic behavior. Combining with the electron paramagnetic resonance results, a direct link between the magnetization and the relative occupancy of the singly charged oxygen vacancies present on the surface of ZnO nanorods is established. [source] Sensory ecology of prey rustling sounds: acoustical features and their classification by wild Grey Mouse LemursFUNCTIONAL ECOLOGY, Issue 1 2007H. R. GOERLITZ Summary 1Predatory mammals and birds from several phylogenetic lineages use prey rustling sounds to detect and locate prey. However, it is not known whether these rustling sounds convey information about the prey, such as its size or profitability, and whether predators use them to classify prey accordingly. 2We recorded rustling sounds of insects in Madagascar walking on natural substrate and show a clear correlation between insect mass and several acoustic parameters. 3In subsequent behavioural experiments in the field, we determined whether nocturnal animals, when foraging for insects, evaluate these parameters to classify their prey. We used field-experienced Grey Mouse Lemurs Microcebus murinus in short-term captivity. Mouse Lemurs are generally regarded as a good model for the most ancestral primate condition. They use multimodal sensorial information to find food (mainly fruit, gum, insect secretions and arthropods) in nightly forest. Acoustic cues play a role in detection of insect prey. 4When presented with two simultaneous playbacks of rustling sounds, lemurs spontaneously chose the one higher above their hearing threshold, i.e. they used the rustling sound's amplitude for classification. We were not able, despite attempts in a reinforced paradigm, to persuade lemurs to use cues other than amplitude, e.g. frequency cues, for prey discrimination. 5Our data suggests that Mouse Lemurs, when foraging for insects, use the mass,amplitude correlation of prey-generated rustling sounds to evaluate the average mass of insects and to guide their foraging decisions. [source] Low-frequency passive seismic experiments in Abu Dhabi, United Arab Emirates: implications for hydrocarbon detectionGEOPHYSICAL PROSPECTING, Issue 5 2010Mohammed Y. Ali ABSTRACT Low-frequency passive seismic experiments utilizing arrays of 3-component broadband seismometers were conducted over two sites in the emirate of Abu Dhabi in the United Arab Emirates. The experiments were conducted in the vicinity of a producing oilfield and around a dry exploration well to better understand the characteristics and origins of microtremor signals (1,6 Hz), which had been reported as occurring exclusively above several hydrocarbon reservoirs in the region. The results of the experiments revealed that a strong correlation exists between the recorded ambient noise and observed meteorological and anthropogenic noises. In the frequency range of 0.15,0.4 Hz, the dominant feature is a double-frequency microseism peak generated by the non-linear interactions of storm induced surface waves in the Arabian Sea. We observed that the double-frequency microseism displays a high variability in spectral amplitude, with the strongest amplitude occurring when Cyclone Gonu was battering the eastern coast of Oman; this noise was present at both sites and so is not a hydrocarbon indicator. Moreover, this study found that very strong microtremor signals in the frequency range of 2,3 Hz were present in all of the locations surveyed, both within and outside of the reservoir boundary and surrounding the dry exploration well. This microtremor signal has no clear correlation with the microseism signals but significant variations in the characteristics of the signals were observed between daytime and nighttime recording periods that clearly correlate with human activity. High-resolution frequency-wavenumber (f - k) spectral analyses were performed on the recorded data to determine apparent velocities and azimuths of the wavefronts for the microseism and microtremor events. The f - k analyses confirmed that the double-frequency microseism originates from wave activity in the Arabian Sea, while the microtremor events have an azimuth pointing towards the nearest motorways, indicating that they are probably being excited by traffic noise. Results drawn from particle motion studies confirm these observations. The vertical-to-horizontal spectral ratios of the data acquired in both experiments show peaks around 2.5,3 Hz with no dependence on the presence or absence of subsurface hydrocarbons. Therefore, this method should not be used as a direct hydrocarbon indicator in these environments. Furthermore, the analyses provide no direct evidence to indicate that earthquakes are capable of stimulating the hydrocarbon reservoir in a way that could modify the spectral amplitude of the microtremor signal. [source] Synthesis of New C(2) -Substituted gluco -Configured Tetrahydroimidazopyridines and Their Evaluation as Glucosidase InhibitorsHELVETICA CHIMICA ACTA, Issue 10 2005Bhagavathy Shanmugasundaram The gluco -configured C(2) -substituted tetrahydroimidazopyridines 8,14 were prepared and tested as inhibitors of the , -glucosidases from Caldocellum saccharolyticum and from sweet almonds, and of the , -glucosidase from brewer's yeast. All new imidazopyridines are nanomolar inhibitors of the , -glucosidases and micromolar inhibitors of the , -glucosidase. The 3-phenylpropyl derivative 14 proved the strongest inhibitor of the Caldocellum , -glucosidase (Ki,=,0.9,nM), only slightly weaker than the known 2-phenylethyl analogue 7, and the propyl derivative 13 is the strongest inhibitor of the sweet almond , -glucosidases (Ki,=,3.2,nM), again slightly weaker than 7. There is no strong dependence of the inhibition on the nature of the C(2) -substituent and no clear correlation between the inhibitory strength of the known manno -configured imidazopyridines 2,6 and the gluco -analogues 8,12. While most manno -imidazopyridines are competitive inhibitors, the gluco -analogues proved non-competitive inhibitors of the Caldocellum , -glucosidase and mixed-type or partial mixed-type inhibitors of the sweet almond , -glucosidases. [source] Regional differences in hippocampal PKA immunoreactivity after training and reversal training in a spatial Y-maze taskHIPPOCAMPUS, Issue 5 2007Robbert Havekes Abstract It is suggested that the hippocampus functions as a comparator by making a comparison between the internal representation and actual sensory information from the environment (for instance, comparing a previously learned location of a food reward with an actual novel location of a food reward in a Y-maze). However, it remains unclear to what extent the various hippocampal regions contribute to this comparator function. One of the proteins known to be crucially involved in the formation of hippocampus-dependent long-term memory is the adenosine 3,,5, cyclic monophosphate dependent protein kinase (PKA). Here, we examined region-specific changes in immunoreactivity (ir) of the regulatory II,,, subunits of PKA (PKA RII,,,-ir) in the hippocampus during various stages of spatial learning in a Y-maze reference task. Thereafter, we compared changes in hippocampal PKA RII,,,-ir induced by training and reversal training in which the food reward was relocated to the previously unrewarded arm. We show that: (1) There was a clear correlation between behavioral performance and elevated PKA RII,,,-ir during the acquisition phase of both training and reversal training in area CA3 and dentate gyrus (DG), (2) PKA RII,,,-ir was similarly enhanced in area CA1 during the acquisition phase of reversal training, but did not correlate with behavioral performance, (3) PKA RII,,,-ir did not change during training or reversal training in the subiculum (SUB), (4) No changes in PKA RII,,, protein levels were found using Western blotting, and (5) AMPA receptor phosphorylation at serine 845 (S845p; the PKA site on the glutamate receptor 1 subunit (GluR1)), was enhanced selectively during the acquisition phase of reversal training. These findings reveal that training and reversal training induce region-specific changes in hippocampal PKA RII,,,-ir and suggest a differential involvement of hippocampal subregions in match-mismatch detection in case of Y-maze reference learning. Alterations in AMPA receptor regulation at the S845 site seems specifically related to the novelty detector function of the hippocampus important for match-mismatch detection. © 2007 Wiley-Liss, Inc. [source] Characterization of 11 novel mutations in the X-linked chronic granulomatous disease (CYBB gene)HUMAN MUTATION, Issue 2 2001Bénédicte Gérard Abstract The most frequent form of chronic granulomatous disease (CGD) is caused by inactivation of the CYBB gene, which encodes the gp91-phox subunit of phagocyte NADPH oxidase. This defect prevents phagocytes from producing reactive oxygen species and thus from eradicating bacterial and fungal infections. We investigated 16 unrelated male patients with suspected X-linked CGD and gp91-phox deficiency. A mutation was found in the CYBB gene of all 16 patients, and 11 of these mutations were novel. Eleven patients (69%) had a point mutation (84G>A in two unrelated patients, and 177C>G, 217C>T, 388C>T, 676C>T, 691C>T, 868C>T, 919A>C, 1384G>T and T1514G in one case each, yielding W28X, C59W, R73X, R130X, R226X, Q231X, R290X, T307P, E462X, L505R gp-91phox). One patient had an in-frame deletion removing two amino acids (R54 and A55). Finally, insertions or duplications were found in four patients (from +1 to +31 bases). Overall, 12 (75%) of the mutations led to the production of a truncated protein. No clear correlation was found between clinical manifestations and genomic/biochemical alterations. Thirteen mothers could be tested, and all were carriers. Hum Mutat 18:163, 2001. © 2001 Wiley-Liss, Inc. [source] Relationship between canopy height and the reference value of surface conductance for closed coniferous standsHYDROLOGICAL PROCESSES, Issue 12 2003Hikaru Komatsu Abstract When estimating the dry-canopy evaporation rate of coniferous stands using the Penman,Monteith equation, it is crucial to determine the reference value of surface conductance Gs. This paper examines the relationship between canopy height and the reference value of Gs based on the maximum value of Gs with a vapour pressure deficit , 1·0 kPa, ,s max. There is a clear correlation between canopy height and ,s max when the projected leaf area index ,3·0. This suggests that using this relationship will enable more accurate determination of the reference value of Gs for closed stands. Copyright © 2003 John Wiley & Sons, Ltd. [source] Epidermal growth factor receptor expression affects the efficacy of the combined application of saponin and a targeted toxin on human cervical carcinoma cellsINTERNATIONAL JOURNAL OF CANCER, Issue 6 2010Diana Bachran Abstract Cervical cancer is the second most common cancer in women worldwide. Targeting the epidermal growth factor receptor (EGFR) is a very promising approach since it is overexpressed in about 90% of cervical tumors. Here, we quantified the toxic effect of SE, a targeted toxin consisting of epidermal growth factor (EGF) as targeting moiety and the plant toxin saporin-3, on 3 common human cervical carcinoma cell lines (HeLa, CaSki and SiHa) and recently established lines (PHCC1 and PHCC2) from 2 different individuals. A human melanocytic and a mouse cell line served as negative control. Additionally, we combined SE with saponinum album, a saponin composite from Gypsophila paniculata, which exhibited synergistic properties in previous studies. The cell lines, except for SiHa cells, revealed high sensitivity to SE with 50% cell survival in the range of 5,24.5 nM. The combination with saponin resulted in a remarkable enhancement of cytotoxicity with enhancement factors ranging from 9,000-fold to 2,500,000-fold. The cytotoxicity of SE was clearly target receptor specific since free EGF blocks the effect and saporin-3 alone was considerably less toxic. For all cervical carcinoma cell lines, we evinced a clear correlation between EGFR expression and SE sensitivity. Our data indicate a potential use of targeted toxins for the treatment of cervical cancer. In particular, the combination with saponins is a promising approach since efficacy is drastically improved. [source] Temperature-dependent kinetic study for ozonolysis of selected tropospheric alkenesINTERNATIONAL JOURNAL OF CHEMICAL KINETICS, Issue 12 2002Elena V. Avzianova Ozonolysis reactions of alkenes are suggested to play major roles in the chemistry of the troposphere. Rate constants for the gas-phase reactions of O3 with a series of alkenes were determined using relative rate technique based on GC/FID measurements of alkene decays. Experiments were carried out in air over the temperature range of 278,353 K at an atmospheric pressure of 760 Torr. An excess of 1,3,5-trimethylbenzene was used as a HO radical scavenger in all experiments. Arrhenius parameters were calculated for ozonolysis of 1-butene, 1-pentene, 1-hexene, 1-heptene, 2-methyl-1-butene, isobutene, trans -2-butene, trans -2-pentene, cis -2-pentene, trans -2-hexene, cis -2-hexene, 3-chloropropene, 1,1-dichloroethene, and isoprene from temperature-dependent studies of the rate constants. The rate constants obtained in this study are compared with previous literature data. A good linear correlation between the logarithms of the rate constants and calculated HOMO energies of selected alkenes is observed. However, no clear correlation could have been drawn for chlorinated substituted alkenes. © 2002 Wiley Periodicals, Inc. Int J Chem Kinet 34: 678,684, 2002 [source] Evolution and features of global land June,August dry/wet periods during 1920,2000INTERNATIONAL JOURNAL OF CLIMATOLOGY, Issue 12 2004Neng Shi Abstract Dry/wet features for the globe and the Northern and Southern Hemispheres are investigated in terms of 1920,2000 June,August (JJA) global land precipitation data. The weighted mean JJA precipitation anomaly index and the weighted mean JJA dry/wet area index are used to describe the extent of global dryness/wetness. It is pointed out that 1988 (1930) was the globally wettest (driest) year in 1920,2000, and 1954 (1976) was the second wettest (driest). The dryness/wetness of the globe and Northern and Southern Hemispheres has shown distinctive interdecadal changes: during the 1920s, global dryness occurred in JJA frequently; from the 1920s to the 1940s global wetness occurred infrequently in JJA; the 1950s,1960s was a period of frequent global JJA wetness; and the 1970s to 2000 was a period of frequent global JJA dryness/wetness, with the number of dry years greater than that of wet years. The dry/wet features of the Northern Hemisphere are comparatively consistent with those of the globe, but there is no obvious relation between JJA mean precipitation anomalies of the two hemispheres. The analyses of the simultaneous and last winter sea-surface temperature anomalies of global dry/wet years reveal that there is clear correlation of JJA global dry/wet change with sea-surface temperature variations and El Niño,southern oscillation (ENSO) events. Global JJA dryness occurs when the summer ENSO (El Niño) is weaker, and global JJA wetness occurs when the summer ENSO is strong. The largest difference between the last winter sea-surface temperature fields for global dry and wet years is that the sea-surface temperature in the North Pacific and North Atlantic for wet years is substantially higher than that for dry years. Copyright © 2004 Royal Meteorological Society [source] Conditioning polymers in today's shampoo formulations , efficacy, mechanism and test methodsINTERNATIONAL JOURNAL OF COSMETIC SCIENCE, Issue 1 2000Hössel Synopsis Today's shampoo formulations are beyond the stage of pure cleansing of the hair. Additional benefits are expected, e.g. conditioning, smoothing of the hair surface, improvement of combability and lather creaminess. Cationic polymers play an important role in providing many of those features. Therefore, within the last few years their use in shampoos has increased greatly. In the only last two decades, shampoo designation has gradually changed from ,2-in-1' to ,3-in-1' and then to ,multifunctional', as at present. The consumer demands products which live up to their promises. Modern shampoos contain a wide variety of ingredients such as co-surfactants, vitamins and pro-vitamins, protein derivatives, silicones, natural-based plant extracts and other ,active ingredients', but there is still a need for conditioning polymers. The specific objective of this study is to assess the conditioning efficacy of cationic polymers and to investigate their mechanisms in a shampoo system. The investigations were carried out on formulations that contained sodium lauryl ether sulphate and different cationic polymers, e.g. Polyquaternium 7, 10, 11, cationic guar gum and Luviquat Care (Polyquaternium 44), a new branched copolymer of vinylpyrrolidone (VP) and quaternized vinylimidazolium salts (QVI). We used test methods relevant to the applications in question, such as combing force measurements, the feel of the hair and the creaminess of the lather, to assess the efficacy. Atomic force microscopy and electrokinetics (streaming potential) were used to detect polymer residues on treated hair. All the polymers under investigation improved the overall performance of the shampoo formulations. This was demonstrated by means of combing force measurements, sensorial tests and analytical methods, namely zeta potential measurement and atomic force microscopy. Polyquaternium 44 exhibited the best conditioning properties on wet hair without sacrificing removability or absence of build-up. The latter are the most striking weaknesses of cationic Guar Gum-based polymers. Polyquaternium 10 can also be removed from the hair after rinsing with anionic surfactant but it does not perform as well as Polyquaternium 44 in the fields of wet combability and sensorial criteria such as lather creaminess and feel of the hair. We postulate that the outstanding properties of Polyquaternium 44 as a conditioning agent for shampoos are due to its tailor-made ,branched' structure. There is a clear correlation between the molecular weight and the efficacy of the new copolymers of VP and QVI. Only cationic polymers with a very high molecular weight are effective as conditioners in shampoos based on anionic surfactants. Surprisingly, they do not have to have a high cationic charge. On the basis of all our results, our postulation is that the polymer residue which is responsible for conditioning does not form a flat layer on the hair. Rather, the polymer residue adsorbs with the few cationic moieties, while the uncharged part of the polymer forms loops, which are orientated away from the hair and which are responsible for the reduced friction between hairs. Résumé Les formulations actuelles de shampoing font plus qu'un simple nettoyage des cheveux. On en attend un intérêt supplémentaire, par exemple après-shampoing, lissage de la surface du cheveu, amélioration de la coiffabilité et aspect crémeux du savon. Les polymères cationiques jouent un rôle important dans l'apport de nombre de ces caractéristiques. Par conséquent, ces quelques dernières années leur utilisation a considérablement augmenté dans les shampoings. Dans les seules deux dernières décades, l'appellation du shampoing est progressivement passée de "2 en 1"à"3 en 1" puis ensuite à"multifonctionnel", comme actuellement. Le consommateur recherche des produits qui tiennent leurs promesses. Les shampoings modernes contiennent une grande diversité d'ingrédients tels que des co-tensioactifs, des vitamines et des provitamines, des dérivés de protéines, des silicones, des extraits à base de plantes naturelles et autres "ingrédients actifs", mais il existe toujours un besoin pour des polymères d'après shampoing. L'objectif spécifique de cette étude est d'évaluer l'efficacité comme après-shampoing de polymères cationiques et de rechercher leurs mécanismes dans le système de shampoing. Les recherches ont été menées sur des formulations qui contiennent du sulfate de lauryl éther sodium et différents polymères cationiques, par exemple du Polyquaternium 7, 10, 11, de la gomme de guar cationique et du Luviquat Care (Polyquaternium 44), un nouveau copolymère ramifié de vinylpyrrolidone (VP) et de sels quaternaires de vinylimidazolium (QVI). Nous avons utilisé les procédés de contrôle appropriées aux applications en question, tels que les mesures de force de coiffage, le toucher du cheveu et l'aspect crémeux du savon, pour évaluer l'efficacité. La microscopie atomique et l'électrocinétique (potentiel d'écoulement) ont été utilisées pour détecter les résidus de polymère sur le cheveu traité. Tous les polymères étudiés améliorent le comportement global des formulations de shampoing. Ceci est démontré au moyen des mesures de force de coiffage, des tests sensoriels et des méthodes analytiques, en l'occurrence la mesure du potentiel zêta et la microscopie atomique. Le Polyquaternium 44 présente les meilleures propriétés d'après-shampoing sur cheveu mouillé sans diminuer sa capacité d'élimination ou l'absence d'accumulation. Ces dernières sont les faiblesses les plus frappantes des polymères à base de gomme de guar cationique. Le Polyquaternium 10 peut aussi être éliminé du cheveu après rinçage avec un tensioactif anionique mais il ne se comporte pas aussi bien que le Polyquaternium 44 dans les domaines de la coiffabilitéà l'état mouillé et des critères sensoriels tels que l'aspect crémeux du savon et du toucher du cheveu. Nous supposons que les propriétés exceptionnelles du Polyquaternium 44 comme agent après-shampoing pour shampoings sont dues à sa structure "ramifiée" conçue sur mesure. Il existe une corrélation claire entre le poids moléculaire et l'efficacité des nouveaux copolymères de VP et QVI. Seuls les polymères cationiques avec un poids moléculaire très élevé sont efficaces comme après shampoings dans des shampoings à base de tensioactifs anioniques. Etonnamment, ils n'ont pas besoin d'avoir une charge cationique élevée. Sur la base de tous nos résultats, notre hypothèse est que le fragment de polymère qui est responsable du traitement ne forme pas une couche plate sur le cheveu. Le fragment de polymère adsorbe plutôt les quelques fragments cationiques, tandis que la partie non chargée du polymère forme des boucles, qui sont orientées à l'extérieur du cheveu et qui sont responsables de la friction réduite entre les cheveux. [source] Sex Differences in the Effect of Heart Rate on Mortality in the ElderlyJOURNAL OF AMERICAN GERIATRICS SOCIETY, Issue 9 2003Gila Perk MD Objectives:, To examine the association between heart rate and mortality risk in the elderly. Design:, Longitudinal cohort. Setting:, Outpatient. Participants: Four hundred twenty-two people, aged 70 upon entry, were surveyed and followed for 6 years. Measurements: Pulse rate was measured manually, while sitting and standing, and heart rate was measured from electrocardiogram recordings. The population was divided into quartiles of heart rate, with the top quartile comprising those with heart rate greater than 77 beats per minute (bpm) and the bottom quartile those with heart rate less than 60 bpm. Results: After controlling for possible confounders, there was a clear correlation (r) between heart rate and all-cause mortality in elderly women (r=0.25, P=.0003). The correlation in women was observed using the three different methods for measuring heart rate. Heart rate was associated with all-cause and cardiovascular mortality. There was no relationship between heart rate and level of exercise or smoking status. In multiple regression analysis, the increased risk of death in the women was independent of previous cardiovascular or cerebrovascular disease, hypertension, anemia, congestive heart failure, smoking, and level of exercise or activities of daily living (relative odds ratio (ROR)=3.37, 95% confidence interval (CI)=0.96,11.8). When women using beta-blockers were excluded, this relationship became even stronger (ROR=8.5, 95% CI=1.19,60.1). Conclusion: Elevated heart rate is related to increased mortality in elderly women, thus representing a simple index of general health status in this population. Elevated heart rate did not predict mortality in elderly men. [source] Timing of high-grade metamorphism: Early Palaeozoic U,Pb formation ages of titanite indicate long-standing high- T conditions at the western margin of Gondwana (Argentina, 26,29°S)JOURNAL OF METAMORPHIC GEOLOGY, Issue 7 2003F. Lucassen Abstract Concordant U,Pb ages of c. 530,510 Ma and c. 470,420 Ma on titanite from calcsilicate, orthogneiss and amphibolite rocks constrain the age of high- T metamorphism in the Early Palaeozoic mobile belt at the western margin of Proterozoic Gondwana (Argentina, 26,29°S). The U,Pb ages document the time of titanite formation at high- T conditions according to the stable mineral paragenesis and occurrence of titanite in the metamorphic fabric. The presence of migmatite at all sample sites indicates temperatures were > c. 650 °C. Titanite formed at similar metamorphic conditions at different times on the regional and on the outcrop scale. The titanite crystals preserved their U,Pb isotopic signatures and chemical composition under ongoing upper amphibolite to granulite facies temperatures. Different thermal peaks or deformations are only detected by the different U,Pb ages and not by changes in the mineral paragenesis or metamorphic fabric of the samples. The range of U,Pb ages, e.g. in the Ordovician and Silurian (c. 470, 460, 440, 430, 420 Ma), is interpreted as the effect polyphase deformation with deformation-enhanced recrystallization of titanite and/or different thermal peaks during a long-standing, geographically fixed, high- T regime in the mid-crust of a continental magmatic arc. A clear correlation of the different ages with distinct tectonic events, e.g. collision of terranes, is not possible based on the present knowledge of the region. [source] Biorelevant dissolution media: Aggregation of amphiphiles and solubility of estradiolJOURNAL OF PHARMACEUTICAL SCIENCES, Issue 2 2006David Ilardia-Arana Abstract Biorelevant dissolution media containing bile salt and lecithin at concentrations appropriate for fed and fasted state are useful when testing oral solid formulations of poorly water-soluble drugs. Dilution of amphiphile solutions affects the aggregation state of the amphiphiles because bile salt is partitioned between the aqueous phase and the aggregates. The aim of the investigation was to study the effect of dilution on the size distribution of aggregates and its effect on the solubilization capacity. Clear buffered solutions of four intestinal amphiphiles (sodium glycocholate, lecithin, monoolein, and oleic acid) and a combination of these were prepared at high bile salt concentration. Micelles in the glycocholate solutions decreased in size when diluted. The addition of insoluble amphiphiles led to bigger micelles with no clear correlation between size of the micelles and amphiphile concentration. Dilution of the two- and four component media caused enlargement of the mixed micelles and formation of vesicles. The solubility of estradiol in the buffer solution was increased with addition of the amphiphiles. A good correlation (R2,=,0.987) was found between estradiol solubility and mass concentration of the amphiphiles. The results demonstrate that, in the case of estradiol, the concentration of amphiphiles rather than the aggregation state determines the solubilization capacity of the medium. © 2005 Wiley-Liss, Inc. and the American Pharmacists Association J Pharm Sci 95:248,255, 2006 [source] A NEW LARVAL FISH BIOASSAY FOR TESTING THE PATHOGENICITY OF PFIESTERIA SPP. (DINOPHYCEAE),JOURNAL OF PHYCOLOGY, Issue 3 2003Vincent J. Lovko Water quality, microbial contamination, prior fish health, and variable results have been major impediments to identifying the cause and mechanism of fish mortality in standard aquarium-format Pfiesteria bioassays. Therefore, we developed a sensitive 96-h larval fish bioassay for assessing Pfiesteria spp. pathogenicity using six-well tissue culture plates and 7-day-old larval cyprinodontid fish. We used the assay to test pathogenicity of several clonal lines of Pfiesteria piscicida Steidinger and Burkholder and P. shumwayae Glasgow and Burkholder that had been cultured with algal prey for 2 to 36 months. The P. shumwayae cultures exhibited 80%,100% cumulative mortality in less than 96 h at initial zoospore densities of approximately 1000 cells·mL,1. No fish mortalities occurred with P. piscicida at identical densities or in controls. In a dose-response assay, we demonstrated a strong positive correlation between dinospore density and fish mortality in a highly pathogenic culture of P. shumwayae, generating a 96-h LD50 of 108 zoospores·mL,1. Additionally, we applied the assay to evaluate a 38-L P. shumwayae bioassay that was actively killing fish and compared results with those from exposures of juvenile tilapia (Oreochromis niloticus) in a 500-mL assay system. Water from the fish-killing 38-L assay was filtered and centrifuged to produce fractions dominated by dinoflagellates, bacteria, or presumed ichthyotoxin (cell-free fraction). After 96 h, the larval fish assay exhibited 50%,100% cumulative mortality only in fractions containing dinoflagellates, with no mortalities occurring in the other fractions. The 500-mL bioassay with tilapia produced inconsistent results and demonstrated no clear correlation between mortality and treatment. The new larval fish bioassay was demonstrated as a highly effective method to verify and evaluate dinoflagellate pathogenicity. [source] Hypersensitivity of Plum Genotypes to Plum Pox VirusJOURNAL OF PHYTOPATHOLOGY, Issue 3-4 2001Kegler The hypersensitive response (HR) of plum hybrid K4 as an active defence mechanism is directed against certain plum pox virus (PPV) strains/isolates of the type CG but not against type DI. There is no clear correlation between the HR of K4 and serological differences of the PPV strains D, M and C, respectively. A total of 14 genotypes out of 21 progenies of K4 reacted necrotically and were proved to be either hypersensitive and field resistant or highly sensitive and not field resistant. The HR can be connected with a complete or with an incomplete virus localization in K4 and some of its progenies. The remaining genotypes were more or less sensitive and tolerant, respectively. Growth of buds from PPV-CG-infected plum cultivars on K4 differed in the degree of systemic virus invasion in the plant as a trait of quantitative virus resistance. The percentage of growing buds correlated with the level of quantitative PPV resistance. [source] Drying Stages during the Heating of High-Alumina, Ultra-Low-Cement Refractory CastablesJOURNAL OF THE AMERICAN CERAMIC SOCIETY, Issue 7 2003Murilo D. M. Innocentini The purpose of this work was to investigate the drying kinetics of high-alumina, ultra-low-cement refractory castables under continuous heating conditions. Three main drying stages were identified during the castable heat-up and were related to the phase change of free water and to the decomposition of hydrated products present in the body. A clear correlation was found between the actual heating profile inside the castable and the dewatering stages under various heating schedules. Thermal analysis was used to assess the drying temperature that represents the highest risk of steam pressure buildup and, thus, of explosive spalling. [source] The influence of pre-fermentative practices on the dominance of inoculated yeast starter under industrial conditionsJOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE, Issue 5 2002Maurizio Ciani Abstract The influence of pre-fermentative practices on the growth dynamics of a ,natural' starter culture with specific phenotype (H2S,) concurrently with wild yeast populations was evaluated under winery conditions. Different clarification procedures and added SO2 strongly influenced species and cell numbers isolable at the pre-fermentation stage. Independent treatments of must with sulphite addition or vacuum-filtering clarification caused a 30-fold reduction in viable cells. Clarification procedures, enhanced by the selective effect of SO2 addition, induced the appearance of Saccharomyces cerevisiae ,wild' yeasts. Correct application of the inoculum generally guarantees the dominance of fermentation by starter cultures. However, inoculated fermentations using unclarified white and red musts exhibited a consistent presence and persistence of non- Saccharomyces and/or Saccharomyces ,wild' yeasts during fermentation. The extent and composition of the initial wild microflora at the start of fermentation may affect the presence and persistence of wild Saccharomyces and non- Saccharomyces yeasts during guided fermentations under commercial conditions. The above findings confirm the results of previous works carried out at laboratory- or pilot-scale level. Furthermore, they suggest a clear correlation between the modality of pre-fermentative practices and the presence and persistence of ,wild' yeasts during fermentation. © 2002 Society of Chemical Industry [source] Lake-specific responses in sedimentary sulphur, after additions of copper sulphate to lakes in Michigan, USALAKES & RESERVOIRS: RESEARCH AND MANAGEMENT, Issue 3 2009Paul E. Drevnick Abstract Copper sulphate (CuSO4) is commonly added to lakes and reservoirs to manage nuisance and exotic species. Several studies have previously reported that CuSO4 is very useful for this purpose, and that the copper is ultimately stored in lake sediments. In contrast, there has been little study on the fate of the sulphate from CuSO4 additions. The purpose of this study was to elucidate the effects of CuSO4 additions on sedimentary sulphur. Concentrations, isotopes, and fluxes of total and reduced sulphur in sediment cores from four Michigan lakes were compared, including two reference lakes that have never received CuSO4 additions, and two treatment lakes that have received CuSO4 additions by lake managers totalling 1,3 kg sulphate ha,1 year,1 since 1940. The results of this study confirm that sediments do not consistently provide records of sulphate loading across lakes. Isotopic evidence indicates this inconsistency is caused, in part, by lakes with well-mixed sediments, in which sulphate is reduced to sulphide, but then subsequently reoxidized to sulphate and remobilized to the overlying water column. One of the treatment lakes, however, exhibited a clear correlation between CuSO4 additions and an increased sulphur flux to the sediment. During any given year, however, the sulphate added from CuSO4 additions amounted to no more than 10% of the sulphate added from wet deposition. Based on this seemingly insignificant quantity of sulphate, ascribing any effect of CuSO4 additions on sedimentary sulphur is tenuous at best. One possibility is that the addition of CuSO4 at rates that do not overwhelm the natural sulphur cycle of a lake or reservoir is a reasonable management tool for nuisance and exotic species. [source] Unravelling causal components of the Ordovician Radiation: the Builth Inlier (central Wales) as a case studyLETHAIA, Issue 2 2008JOSEPH P. BOTTING Hypotheses about the causes of biodiversification during the Ordovician have been focused in three main areas: tectonic activity and nutrient supply, palaeogeography, and ecological escalation. There is as yet no consensus on mechanisms, and it is unclear whether it is better to study the patterns at local or regional scales. By applying ecological knowledge to the available palaeontological information, it can be shown that neither tectonic nor palaeogeographic effects could account for the permanence of the diversity rise, in the absence of elements of ecological escalation. However, it may be possible to identify trigger mechanisms resulting in enhanced speciation or reduced extinction. Areas of local diversity increase should be distinguished from speciation centres. An ongoing study of the Middle Ordovician Builth-Llandrindod Inlier of central Wales, conducted over 10 years, has identified elements of all three of the above categories of causal mechanisms affecting local diversity. This implies that the patterns of causal relationship and diversification are complex even at very local scales, and at this stage we should not anticipate a clear correlation of global diversity with any single factor. More data are needed from small-scale but intensive studies before we can generalize about the causal mechanisms of the Ordovician Radiation. [source] X-ray diffraction of amorphous and crystalline overbased sulphonatesLUBRICATION SCIENCE, Issue 3 2005Michael T. Costello Abstract Colloidal dispersions of calcium carbonate stabilised by overbased sulphonates are used as lubricant additives to provide detergency, remove acidity, and prevent wear. In the present work various overbased sulphonate compounds have been analysed using X-ray diffraction (XRD). The amorphous overbased sulphonates studied displayed broad diffraction patterns while the crystalline overbased sulphonates gave well-defined diffraction patterns, correlating with the particle size. The XRD distances of the series of Mg, Ca, and Ba overbased sulphonates shifted to greater values and displayed a clear correlation (r = 0.98) with the ionic radius of the cations used. [source] Ionized gas in E/S0 galaxies with dust lanesMONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, Issue 4 2010Ido Finkelman ABSTRACT We report the results of multicolour observations of 30 E/S0 galaxies with dust lanes. For each galaxy we obtained broad-band images and narrow-band images using interference filters isolating the H,+[N ii] emission lines to derive the amount and morphology of dust and ionized gas. To improve the wavelength coverage we retrieved data from the Sloan Digital Sky Survey and Two Micron All Sky Survey and combined these with our data. Ionized gas is detected in 25 galaxies and shows in most cases a smooth morphology, although knots and filamentary structure are also observed in some objects. The extended gas distribution closely follows the dust structure, with a clear correlation between the mass of both components. An extinction law by the extragalactic dust in the dark lanes is derived and is used to estimate the dust content of the galaxies. The derived extinction law is used to correct the measured colours for intrinsic dust extinction and the data are fitted with a stellar population synthesis model. We find that the H, emission and colours of most objects are consistent with the presence of an ,old' stellar population (,10 Gyr) and a small fraction of a ,young' population (, 10,100 Myr). To check this we closely examine NGC 5363, for which archival Spitzer/Infrared Array Camera and Galaxy Evolution Explorer data are available, as a representative dust-lane E/S0 galaxy of the sample. [source] Metallicity, planetary formation and migrationMONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, Issue 3 2003Mario Livio ABSTRACT Recent observations show a clear correlation between the probability of hosting a planet and the metallicity of the parent star. As radial velocity surveys are biased, however, towards detecting planets with short orbital periods, the probability,metallicity correlation could merely reflect a dependence of migration rates on metallicity. We investigated the possibility, but find no basis to suggest that the migration process is sensitive to the metallicity. The indication is, therefore, that a higher metallicity results in a higher probability for planet formation. [source] | ||||||||||||||||||||||||||||||||||