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Kinds of Span Selected AbstractsCell-free Protein Synthesis through Solubilisate Exchange in Water/Oil Emulsion CompartmentsCHEMBIOCHEM, Issue 8 2004Adriana V. Pietrini Dr. Abstract This work is aimed at finding conditions under which synthetic compartments used as cell models can fuse with each other and allow reagents contained in the different compartments to react. This goal seems to be best achieved by the use of water in oil emulsions (w/o) with dimensions in the range of 30,60 ,m. In particular, cell-free EGFP (enhanced green fluorescent protein) synthesis takes place in Tween 80/Span 80 w/o emulsions, and the extent of the reaction can be monitored directly by fluorescence. The medium is mineral oil, containing 0.5,% v/v aqueous solution. Different premixing configurations of the components (plasmid, amino acids, E. Coli extract) are used and compared. The in vitro synthesis of EGFP in emulsion droplets proceeds for 1 h, and the yield is 7.5 ng,,L,1protein. EGFP synthesis in aqueous solution takes place for at least 5 h. The yield is 10.5 ng,,L,1protein after 1 h and 15.8 ng,,L,1protein after 5 h.The results with the w/o emulsions show that solubilisate exchange takes place among the different water droplets, but it is not possible to demonstrate clearly that a true fusion takes place. [source] ARREST TRAJECTORIES ACROSS A 17-YEAR SPAN FOR YOUNG MEN: RELATION TO DUAL TAXONOMIES AND SELF-REPORTED OFFENSE TRAJECTORIES,CRIMINOLOGY, Issue 4 2007MARGIT WIESNER The purpose of this study was to evaluate the impact of different operationalizations of offending behavior on the identified trajectories of offending and to relate findings to hypothesized dual taxonomy models. Prior research with 203 young men from the Oregon Youth Study identified six offender pathways, based on self-report data (Wiesner and Capaldi, 2003). The current study used official records data (number of arrests) for the same sample. Semiparametric groupbased modeling indicated three distinctive arrest trajectories: high-level chronics, low-level chronics, and rare offenders. Both chronic arrest trajectory groups were characterized by relatively equal rates of early onset offenders, which indicates, therefore, some divergence from hypothesized dual taxonomies. Overall, this study demonstrated limited convergence of trajectory findings across official records versus selfreport measures of offending behavior. [source] HOST LIFE SPAN AND THE EVOLUTION OF RESISTANCE CHARACTERISTICSEVOLUTION, Issue 1 2007Martin R. Miller There is a wide variety of resistance mechanisms that hosts may evolve in response to their parasites. These can be functionally classified as avoidance (lower probability of becoming infected), recovery (faster rate of clearance), tolerance (reduced death rate when infected), or acquired immunity. It is commonly thought that longer lived organisms should invest more in costly resistance. We show that due to epidemiological feedbacks the situation is often more complex. Using evolutionary theory we examine how the optimal investment in costly resistance varies with life span in a broad range of scenarios. In the absence of acquired immunity, longer lived populations do generally invest more in resistance. If hosts have acquired immunity, the optimal resistance may either increase or decrease with increasing life span. In addition, there may be evolutionary bistability with high and low investments in avoidance or tolerance. The optimal investment in the duration of acquired immunity always increases with life span, and due to bistability, shorter lived hosts may commonly not evolve any immunity. In contrast, the optimal investment in the probability of acquiring immunity initially increases and then decreases with life span. Our results have important implications for the evolution of invertebrate and vertebrate immunity, and for the evolution of acquired immunity itself. [source] INACTIVATION OF ESCHERICHIA COLI O157:H7 ON INOCULATED ALFALFA SEEDS WITH OZONATED WATER UNDER PRESSURE,JOURNAL OF FOOD SAFETY, Issue 2 2002RATNA R. SHARMA ABSTRACT Alfalfa seeds inoculated with Escherichia coli O157:H7 (,105 CFU/g) were subjected to low hydrostatic pressure. Seeds immersed in ozonated water at 4C were held at 8 and 12-psi ozone pressure for 2, 4, 8, 16, 32, and 64 min. Alternatively, seeds were continuously sparged with ozone for up to 64 min and then held at 12 psi for 5 min. Controls consisted of sparging and pressurization with air. Thirty-two minute treatments of continuous ozone sparging followed by pressurization of seeds at 12 psi for 5 min were repeated with the addition of four surfactants (Tween 20, Tween 80, SPAN 20, and SPAN 80) in the treatment water. Enumeration of E. coli O157:H7 on treated, untreated, and control seeds was done on tryptic soy agar supplemented with 50 ,g/mL of nalidixic acid. The reduction in population of E. coli O157:H7 on seeds treated with the 8 and 12 psi hydrostatic pressure in ozonated water ranged from 0.74 ,1.56 log10 CFU/g and 0.72 , 1.62 log10 CFU/g, respectively. Control treatments carried out with air pressurization of seeds resulted in maximum population reductions of 1.55 log10 and 1.83 log10 CFU/g for 8 and 12 psi, respectively. For seeds treated with continuous ozone sparging (2 , 64 min) followed by pressurization at 12 psi for 5 min, the highest reduction was 2.03 log10 CFU/g. Reductions were, however, not significantly different (P > 0.05) from control treatment (with air) which reduced the populations by 0.57 , 2.19 log10 CFU/g. The presence of surfactants during continuous sparging of water followed by pressurization at 12 psi was not beneficial. None of the treatments adversely affected the germination of the seeds. [source] Synthesis of metal (Fe or Pd)/alloy (Fe,Pd)-nanoparticles-embedded multiwall carbon nanotube/sulfonated polyaniline composites by , irradiationJOURNAL OF POLYMER SCIENCE (IN TWO SECTIONS), Issue 10 2006Kakarla Raghava Reddy Abstract Composites of multiwall carbon nanotubes (MWCNTs) and sulfonated polyaniline (SPAN) were prepared through the oxidative polymerization of a mixture of aniline, 2,5-diaminobenzene sulfonic acid, and MWCNTs. Fe, Pd, or Fe,Pd alloy nanoparticles were embedded into the MWCNT,SPAN matrix by the reduction of Fe, Pd, or a mixture of Fe and Pd ions with , radiation. Sulfonic acid groups and the emeraldine form of backbone units in SPAN served as the source for the reduction of the metal ions in the presence of , radiation. The existence of metallic/alloy particles in the MWCNT,SPAN matrix was further ascertained through characterization by high-resolution transmission electron microscopy (HRTEM), Fourier transform infrared spectroscopy, ultraviolet,visible spectroscopy, thermogravimetric analysis, and conductivity measurements. HRTEM pictures clearly revealed the existence of Fe, Pd, and Fe,Pd nanoparticles of various sizes in the MWCNT,SPAN matrices. There were changes in the electronic properties of the MWCNT,SPAN,M composites due to the interaction between the metal nanoparticles and MWCNT,SPAN. Metal-nanoparticle-loaded MWCNT,SPAN composites (MWCNT,SPAN,M; M = Fe, Pd, or Fe,Pd alloy) showed better thermal stability than the pristine polymers. The conductivity of the MWCNT,SPAN,M composites was approximately 1.5 S cm,1, which was much higher than that of SPAN (2.46 × 10,4 S cm,1). Metal/alloy-nanoparticle-embedded, MWCNT-based composite materials are expected to find applications in molecular electronics and other fields. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 3355,3364, 2006 [source] Synthesis and properties of magnetite/poly (aniline-co-8-amino-2-naphthalenesulfonic acid) (SPAN) nanocompositesPOLYMERS FOR ADVANCED TECHNOLOGIES, Issue 1 2007Kakarla Raghava Reddy Abstract Composites were prepared by incorporating magnetite (Fe3O4) nanoparticles into the matrix of a sulfonated polyaniline (SPAN) [poly(aniline-co-8-amino-2-naphthalenesulfonic acid) PANSA] through chemical oxidative polymerization of a mixture of aniline and 8-amino-2-naphthalenesulfonic acid in the presence of magnetite nanoparticles. The composite, magnetite/SPAN(PANSA) was characterized by means of transmission electron microscopy (TEM), X-ray diffraction (XRD), elemental analysis (EA), Fourier transform infrared (FT-IR) spectra, UV-vis spectroscopy, thermogravimetric analysis (TGA), conductivity and magnetic properties measurements. TEM image shows that magnetite nanoparticles were finely distributed into the SPAN matrix. XRD pattern of the nanocomposite reveals the presence of additional crystalline order through the appearance of a sharp peak at ,43° and 71°. Conductivity of the nanocomposite (0.23,S/cm) is much higher than pristine copolymer (1.97,×,10,2,S/cm). The results of FT-IR and UV-visible spectroscopy reveal the presence of molecular level interactions between SO groups in SPAN and magnetite nanoparticles in the composite. Copyright © 2006 John Wiley & Sons, Ltd. [source] Infant Symbolic Play as an Early Indicator of Fetal Alcohol-Related DeficitINFANCY, Issue 6 2010Christopher D. Molteno Infant symbolic play was examined in relation to prenatal alcohol exposure and socioenvironmental background and to predict which infants met criteria for fetal alcohol syndrome (FAS) at 5 years. A total of 107 Cape-Colored, South African infants born to heavy drinking mothers and abstainers/light drinkers were recruited prenatally. Complexity of play, sociodemographic and psychological correlates of maternal alcohol use, and quality of parenting were assessed at 13 months, and intelligence quotient and FAS diagnosis at 5 years. The effect of drinking on spontaneous play was not significant after control for social environment. In contrast, prenatal alcohol and quality of parenting related independently to elicited play. Elicited play predicted 5-year Digit Span and was poorer in infants subsequently diagnosed with FAS/partial FAS and in nonsyndromal heavily exposed infants, compared with abstainers/light drinkers. Thus, symbolic play may provide an early indicator of risk for alcohol-related deficits. The independent effects of prenatal alcohol and quality of parenting suggest that infants whose symbolic play is adversely affected by alcohol exposure may benefit from stimulation from a responsive caregiver. [source] Cognitive correlates of brain MRI subcortical signal hyperintensities in non-demented elderlyINTERNATIONAL JOURNAL OF GERIATRIC PSYCHIATRY, Issue 1 2006Gad A. Marshall Abstract Objective To investigate the relationship between magnetic resonance imaging (MRI) subcortical gray and capsular (SGCH) and white matter hyperintensities (WMH) and cognitive functions in non-demented community dwelling elderly. Methods The severity of SGCH and WMH on proton density and T2 MR images in 16 subjects was scored using the semi-quantitative rating scale of Scheltens et al. (1993). A limited series of cognitive tests selected a priori were then correlated with severity of SGCH and WMH. Results Analysis demonstrated that severity of SGCH was inversely related to performance on the Digit Span (R,=,,0.64, p,<,0.01) and the Stroop Color Word Tests (R,=,,0.64, p,<,0.01). Severity of WMH was related to worsening performance on the Trail Making Test (R,=,0.67, p,<,0.005). Conclusions These findings indicate that severity of WMH is negatively related to more pure executive cognitive functions, specifically set shifting, while severity of SGCH is inversely related to more basic functions of attention and working memory. Copyright © 2005 John Wiley & Sons, Ltd. [source] Effect of Temperature on Fecundity, Life Span and Morphology of Long- and Short-Spined Clones of Brachionus caudatus f. apsteini (Rotifera)INTERNATIONAL REVIEW OF HYDROBIOLOGY, Issue 6 2008Sujiporn Athibai Abstract We investigated the effect of temperature (20, 25 and 30 °C) on fecundity, life span and morphology of the rotifer Brachionus caudatus f. apsteini. For each temperature, short posterior-spined and long posterior-spined clones of B. caudatus f. apsteini were individually cultured for up to six generations. The rotifers were fed Chlorella sp. at a density of 1 × 106 cells ml,1. Morphometric data (body size and spine length) were collected. Total number of offspring producing by a single female per life cycle at high temperature was higher than at low temperature. The duration of juvenile period, reproductive period, post-reproductive period and life span of both clones of B. caudatus f. apsteini decreased with increasing temperature. All offspring of short posterior-spined clone produce posterior spines at 20 and 25 °C, with an average length of 19.8 ± 6.6 and 11.9 ± 2.6 ,m, respectively. In contrast, they cannot develop posterior spines at 30 °C, at which the average length of the posterior spine remnant was 6.4 ± 1.3 ,m. On the other hand, all offspring of long posterior-spined clone have long posterior spines with average lengths of 36.8 ± 6.1, 36.3 ± 5.2 and 36.6 ± 6.2 ,m at 20, 25 and 30 °C, respectively. This study indicated that the production of posterior spines can be induced by low temperature and that short posterior-spined and long posterior-spined clones are genetically different. (© 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Fabrication by three-phase emulsification of pellicular adsorbents customised for liquid fluidised bed adsorption of bioproductsJOURNAL OF CHEMICAL TECHNOLOGY & BIOTECHNOLOGY, Issue 11 2003Mohsen Jahanshahi Abstract A novel dense pellicular adsorbent, custom-designed for liquid fluidised bed adsorption of protein bioproducts, has been fabricated by coating zirconia,silica particles with agarose gel in a three-phase emulsification process. A slurry feedstock comprising solid zirconia,silica particles (120 µm average diameter) suspended in an aqueous solution of agarose was emulsified in an oil,surfactant mixture in a stirred vessel to yield composite droplets. These were subsequently stabilised by cooling to form spherical pellicular particles characterised by a porous, pellicular coat cast upon a solid core. The impact of agitation speed, surfactant concentration, oil viscosity and slurry composition upon the pellicle depth and overall particle diameter was investigated. Pellicle depth decreased with increasing impeller speed and decreased oil viscosity, whilst increased slurry viscosity enhanced that parameter. Initial increases from low concentrations of Span 80 surfactant (0.1% w/v oil) reduced the depth of the agarose pellicle, but the highest values investigated (1.5% w/v oil) promoted particle aggregation. The fluidisation behaviour of particles fabricated under various conditions was characterised by the measurement of expansion coefficients and axial dispersion coefficients for the liquid phase when operated in a standard fluidised bed contactor. Both parameters were found to be comparable or superior to those reported for conventional, composite fluidised bed adsorbents. The controlled coating of porous agarose upon a solid core to yield specific pellicular geometries is discussed in the context of the fabrication of adsorbents customised for the recovery of a variety of bioproducts (macromolecules, nanoparticulates) from complex particulate feedstocks (whole broths, cell disruptates and unclarified bio-extracts). Given the agreement between the size of the pellicular particles and the trends expected from theory, the large-scale manufacture of such particles for customised industrial use is recommended. Copyright © 2003 Society of Chemical Industry [source] From the National Institute of Nursing Research,Annotated Bibliography of National Institute of Nursing Research Findings on Women's Health Across the Life Span: 2007 UpdateJOURNAL OF OBSTETRIC, GYNECOLOGIC & NEONATAL NURSING, Issue 6 2007Raymond J. Bingham First page of article [source] From the National Institute of Nursing Research,Annotated Bibliography of NINR Findings on Women's Health Across the Life Span: 2006 UpdateJOURNAL OF OBSTETRIC, GYNECOLOGIC & NEONATAL NURSING, Issue 6 2006Raymond J Bingham First page of article [source] Annotated Bibliography of NINR Findings on Women's Health Across the Life Span: 2005 UpdateJOURNAL OF OBSTETRIC, GYNECOLOGIC & NEONATAL NURSING, Issue 6 2005Human Services, National Institute of Nursing Research, National Institutes of Health, U.S. Department of Health First page of article [source] Longitudinal Studies of Anger and Attention Span: Context and Informant EffectsJOURNAL OF PERSONALITY, Issue 2 2010Jungmeen Kim ABSTRACT This study examined stabilities of informant and context (home vs. classroom) latent factors regarding anger and attention. Participants included children from the National Institute of Child Health and Development Study of Early Child Care and Youth Development who were measured at 54 months, first grade, and third grade. Latent factors of anger and attention span were structured using different indicators based on mothers', fathers', caregivers', teachers', and observers' reports. We used structural equation modeling to examine the autoregressive effects within a context (stability), the concurrent associations between home and classroom contexts, and informant effects. The results indicated that for both anger and attention (1) there were significant informant effects that influenced stability in a context, (2) there was higher stability in home context than nonhome context, and (3) stability within a context increased over time. The findings suggested that anger was more prone to context effects and informant effects than attention. [source] Self-emulsifying O/W formulations of paclitaxel prepared from mixed nonionic surfactantsJOURNAL OF PHARMACEUTICAL SCIENCES, Issue 5 2010Jen-Ting Lo Abstract Nonionic self-emulsifying oil-in-water (O/W) formulations free of Cremophore® were developed as drug delivery vehicles for paclitaxel. The surfactants used included phosphatidylcholine purified from egg yolk (EPC), Tween, and Span. Oils phases were either pure components or blends from benzyl alcohol, 2-phenylethanol benzyl benzoate, and tributyrin. Among these surfactants, mixtures of EPC and Tween-80 gave really stable emulsions in proper sizes ranging from 70 to 200,nm, mainly depends on the ratio of EPC to Tween-80 and amount of oils. Paclitaxel could be well preserved without any loss in oily stocks, namely mixtures of oils and paclitaxel as well as surfactants, stored at 4°C for more than 8 months. Only gentle mixing on oily stocks with aqueous diluents is enough to make paclitaxel-contained emulsions. The optimum formulation contains oils from 1 to 3 wt%, Tween-80 and EPC from 0.4 to 1.2 wt%, respectively. Consequently, near 500,ppm of paclitaxel can be contained in emulsions. Moreover, these paclitaxel-containing emulsions are compatible with commonly used injection fluids. No precipitation is observed upon preparation of emulsion from dilution of oily stocks. Negligible cytotoxicity on these emulsions assessed with NIH/3T3 cells implied their good biocompatibility and promising applications as drug delivery carriers. © 2009 Wiley-Liss, Inc. and the American Pharmacists Association J Pharm Sci 99: 2320,2332, 2010 [source] Enhancement of nortriptyline penetration through human epidermis: influence of chemical enhancers and iontophoresisJOURNAL OF PHARMACY AND PHARMACOLOGY: AN INTERNATI ONAL JOURNAL OF PHARMACEUTICAL SCIENCE, Issue 4 2008Virginia Merino Different known percutaneous chemical enhancers and iontophoresis have been tested in-vitro to study their ability to increase transdermal absorption of nortriptyline hydrochloride (20 mg mL,1). The chemicals 1-dodecanol, Span 20, Azone, (R)-(+)-limonene or isopropyl myristate were used as an overnight pretreatment at 5% (w/w) in ethanol. Furthermore, isopropyl myristate (20%, w/w) and propylene glycol (15%, w/w) were tested in the same vehicle. Iontophoresis was applied directly to the nortriptyline hydrochloride donor solution for three different concentrations (20, 2 and 0.5 mgmL,1). The chemical enhancers slightly increased the nortriptyline transdermal flux but iontophoresis was more efficient. In this case, nortriptyline transdermal flux was concentration dependent, having a higher flux when the concentration was lowered. Therefore, iontophoresis was the most suitable technique to increase transdermal absorption of nortriptyline and it could be an alternative method to provide therapeutic concentrations of this drug in smoking cessation treatment. [source] Studying Personal Relationships Across the Life SpanPERSONAL RELATIONSHIPS, Issue 4 2008REBECCA G. ADAMS No abstract is available for this article. [source] Does Late Reproduction Extend the Life Span?POPULATION AND DEVELOPMENT REVIEW, Issue 3 2004Findings from European Royalty Statistical associations between late reproduction and female longevity led to speculations that a late birth increases a mother's life span. The database used here includes all descendants of King George I of England (1660,1727) and his wife, Sophie Dorothea (1666,1726), born in the royal dynasties in Europe up to 1939 (n=1,672). In the era of British world supremacy, these descendants formed the uppermost layer of the European aristocracy, occupying all royal thrones from 1850 onward. Novel in this study is the use of pedigree information. In pairs of ever-married full sisters (brothers), both surviving to 45 (50) years, both having at least one child, the study examines whether the sibling with the first,or last,child born later in life also lived a longer life. This design controls for genetics, socioeconomic status, parity, social support, child mortality, birth cohort, and various environmental factors. In the 157 pairs of sisters and 191 pairs of brothers, later reproduction did not extend the life span. [source] Binary coalescence of air bubbles in viscous liquids in presence of non-ionic surfactantTHE CANADIAN JOURNAL OF CHEMICAL ENGINEERING, Issue 4 2008K. Giribabu Abstract Coalescence of air bubbles is important in gas,liquid reactors and food processing operations. Bubbles can be stabilized by using non-ionic surfactants. Binary coalescence of air bubbles in ethylene glycol and aqueous glycerol solutions were studied in this work in presence of Span 80. A novel set-up was developed to study long coalescence times. Coalescence time was observed to follow broad stochastic distributions in all systems. The distributions were fitted with a stochastic model developed earlier. The surface tension of ethylene glycol and glycerol solutions was measured at various concentrations of Span 80. These data were fitted using a surface equation of state derived from the Langmuir isotherm. The effect of surfactant concentration on coalescence time was explained in terms of the surface excess of the surfactant and the repulsive force generated at the air,liquid interface. The results from this work illustrate the stochastic nature of bubble coalescence in viscous liquids. This work also demonstrates how non-ionic surfactants can stabilize bubbles in such liquids. La coalescence des bulles d'air est importante dans les réacteurs gaz-liquide et les opérations de l'industrie alimentaire. Les bulles peuvent être stabilisées en utilisant des surfactants non ioniques. La coalescence binaire de bulles d'air dans des solutions aqueuses d'éthylène glycol et de glycérol a été étudiée dans ce travail en présence de Span 80. Un nouveau montage a été mis au point pour caractériser les temps de coalescence longs. Le temps de coalescence a été observé afin de suivre les distributions de modèle stochastique dans tous les systèmes. Les distributions ont été calées à un modèle stochastique mis au point antérieurement. La tension de surface des solutions d'éthylène glycol et de glycérol a été mesurée à différentes concentrations de Span 80. Ces données ont été calées à l'aide d'une équation d'état de surface calculée à partir de l'isotherme de Langmuir. L'effet de la concentration de surfactant sur le temps de coalescence est expliqué par l'excès de surface du surfactant et la force répulsive créée à l'interface air-liquide. Les résultats de ce travail illustrent la nature stochastique de la coalescence des bulles dans les liquides visqueux. Ce travail démontre également comment les surfactants non ioniques peuvent stabiliser les bulles dans de tels liquides. [source] Executive functions as endophenotypes in ADHD: evidence from the Cambridge Neuropsychological Test Battery (CANTAB)THE JOURNAL OF CHILD PSYCHOLOGY AND PSYCHIATRY AND ALLIED DISCIPLINES, Issue 7 2010Susan Shur-Fen Gau Background:, Little is known about executive functions among unaffected siblings of children with attention deficit/hyperactivity disorder (ADHD), and there is lack of such information from non-Western countries. We examined verbal and nonverbal executive functions in adolescents with ADHD, unaffected siblings and controls to test whether executive functions could be potential endophenotypes for ADHD. Methods:, We assessed 279 adolescents (age range: 11,17 years) with a childhood diagnosis of DSM-IV ADHD, 136 biological siblings (108 unaffected, 79.4%), and 173 unaffected controls by using psychiatric interviews, the Wechsler Intelligence Scale for Children , 3rd edition (WISC-III), including digit spans, and the tasks involving executive functions of the Cambridge Neuropsychological Test Automated Battery (CANTAB): Intra-dimensional/Extra-dimensional Shifts (IED), Spatial Span (SSP), Spatial Working Memory (SWM), and Stockings of Cambridge (SOC). Results:, Compared with the controls, adolescents with ADHD and unaffected siblings had a significantly shorter backward digit span, more extra-dimensional shift errors in the IED, shorter spatial span length in the SSP, more total errors and poorer strategy use in the SWM, and fewer problems solved in the minimum number of moves and shorter initial thinking time in the SOC. The magnitudes of the differences in the SWM and SOC increased with increased task difficulties. In general, neither persistent ADHD nor comorbidity was associated with increased deficits in executive functions among adolescents with ADHD. Conclusions:, The lack of much difference in executive dysfunctions between unaffected siblings and ADHD adolescents suggests that executive dysfunctions may be useful cognitive endophenotypes for ADHD genetic studies. [source] His-tagged protein purification by metal-chelate affinity extraction with nickel-chelate reverse micellesBIOTECHNOLOGY PROGRESS, Issue 4 2010Xiao-Yan Dong Abstract Di(2-ethylhexyl) phosphoric acid (HDEHP) was used as a transition metal ion chelator and introduced to the nonionic reverse micellar system composed of equimolar Triton X-45 and Span 80 at a total concentration of 30 mmol/L. Ni(II) ions were chelated to the HDEHP dimers in the reverse micelles, forming a complex denoted as Ni(II)R2. The Ni(II)-chelate reverse micelles were characterized for the purification of recombinant hexahistidine-tagged enhanced green fluorescent protein (EGFP) expressed in Escherichia coli. The affinity binding of EGFP to Ni(II)R2 was proved by investigation of the forward and back extraction behaviors of purified EGFP. Then, EGFP was purified with the affinity reverse micelles. It was found that the impurities in the feedstock impeded EGFP transfer to the reverse micelles, though they were little solubilized in the organic phase. The high specificity of the chelated Ni2+ ions toward the histidine tag led to the production of electrophoretically pure EGFP, which was similar to that purified by immobilized metal affinity chromatography. A two-stage purification by the metal-chelate affinity extraction gave rise to 87% recovery of EGFP. Fluorescence spectrum analysis suggests the preservation of native protein structure after the separation process, indicating the system was promising for protein purification. © 2010 American Institute of Chemical Engineers Biotechnol. Prog., 2010 [source] A metal-chelate affinity reverse micellar system for protein extractionBIOTECHNOLOGY PROGRESS, Issue 1 2010Xiao-Yan Dong Abstract A new nonionic reverse micellar system is developed by blending two nonionic surfactants, Triton X-45 and Span 80. At total surfactant concentrations lower than 60 mmol/L and molar fractions of Triton X-45 less than 0.6, thermodynamically stable reverse micelles of water content (W0) up to 30 are formed. Di(2-ethylhexyl) phosphoric acid (HDEHP; 1,2 mmol/L) is introduced into the system for chelating transition metal ions that have binding affinity for histidine-rich proteins. HDEHP exists in a dimeric form in organic solvents and a dimer associated with one transition metal ion, including copper, zinc, and nickel. The copper-chelate reverse micelles (Cu-RM) are characterized for their W0, hydrodynamic radius (Rh), and aggregation number (Nag). Similar with reverse micelles of bis-2-ethylhexyl sodium sulfosuccinate (AOT), Rh of the Cu-RM is also linearly related to W0. However, Nag is determined to be 30,90 at W0 of 5,30, only quarter to half of the AOT reverse micelles. Then, selective metal-chelate extraction of histidine-rich protein (myoglobin) by the Cu-RM is successfully performed with pure and mixed protein systems (myoglobin and lysozyme). The solubilized protein can be recovered by stripping with imidazole or ethylinediaminetetraacetic acid (EDTA) solution. Because various transition metal ions can be chelated to the reverse micelles, it is convinced that the system would be useful for application in protein purification as well as simultaneous isolation and refolding of recombinant histidine-tagged proteins expressed as inclusion bodies. © 2009 American Institute of Chemical Engineers Biotechnol. Prog., 2010 [source] Protein Refolding Mediated by Reverse Micelles of Cibacron Blue F-3GA Modified Nonionic SurfactantBIOTECHNOLOGY PROGRESS, Issue 2 2006Xiao-Yue Wu An affinity-based reverse micellar system formulated with nonionic surfactant was applied to the refolding of denatured-reduced lysozyme. The nonionic surfactant of sorbitan trioleate (Span 85) was modified with Cibacron Blue F-3GA (CB) as an affinity surfactant (CB-Span 85) to form affinity-based reverse micelles in n -hexane. The water content of 15 was found optimal for lysozyme refolding in the reverse micellar system of 62.7 mmol/L Span 85 with coupled CB of 0.3 and 0.5 mmol/L. In addition, the operating conditions such as pH and the concentrations of urea and redox reagents were optimized. Under the optimized conditions, complete renaturation of lysozyme at 3,3.5 mg/mL was achieved, whereas dilution refolding in the bulk aqueous phase under the same conditions gave much lower activity recovery. Moreover, the secondary structure of the refolded lysozyme was found to be the same as the native lysozyme. Over 95% of the refolded lysozyme was recovered from CB-Span 85 reverse micelles by a stripping solution of 0.5 mol/L MgCl2. Thus, the present system is advantageous over the conventional reverse micellar system formed with ionic surfactants in the ease of protein recovery. [source] Unsolvable Fear, Trauma, and Psychopathology: Theory, Research, and Clinical Considerations Related to Disorganized Attachment Across the Life SpanCLINICAL PSYCHOLOGY: SCIENCE AND PRACTICE, Issue 3 2001Jude Cassidy This article features a selective review of attachment theory and research that have contributed knowledge about dynamics underlying early trauma, mechanisms by which maladaptive responses to trauma may be transmitted between generations, and trauma-related risk factors for psychopathology in children, adolescents, and adults. First, we focus on the foundations of attachment theory and discuss ways in which the attachment, exploratory, and fear behavioral systems interact to promote infants' survival. The second section of the paper examines the connection between frightening experiences and disorganized attachment. Infants who are regularly and seriously frightened by aspects of their caregiving environment are believed to be at risk for "unsolvable fear" in which organized attachment responses to fear are impossible. We describe the behaviors and representations characteristic of disorganized children and their parents. Next, we review recent research about relations among attachment, trauma, and psychopathology across the lifespan. Finally, we discuss implications of these findings for clinical practice. [source] Inequality in Life Spans and a New Perspective on Mortality Convergence Across Industrialized CountriesPOPULATION AND DEVELOPMENT REVIEW, Issue 4 2005Ryan D. Edwards The second half of the twentieth century witnessed substantial convergence in life expectancy around the world. We examine differences in the age pattern of mortality in industrialized countries over time to show that inequality in adult life spans, which we measure with the standard deviation of life table ages at death above age 10 years, S10, is increasingly responsible for the remaining divergence in mortality. We report striking differences in level and trend of S10 across industrialized countries since 1960, which cannot be explained by aggregate socioeconomic inequality or differential external-cause mortality. Rather, S10 reflects both within- and between-group inequalities in life spans and conveys new information about their combined magnitudes and trends. These findings suggest that the challenge for health policies in this century is to reduce inequality, not just lengthen life. [source] Synthesis and properties of magnetite/poly (aniline-co-8-amino-2-naphthalenesulfonic acid) (SPAN) nanocompositesPOLYMERS FOR ADVANCED TECHNOLOGIES, Issue 1 2007Kakarla Raghava Reddy Abstract Composites were prepared by incorporating magnetite (Fe3O4) nanoparticles into the matrix of a sulfonated polyaniline (SPAN) [poly(aniline-co-8-amino-2-naphthalenesulfonic acid) PANSA] through chemical oxidative polymerization of a mixture of aniline and 8-amino-2-naphthalenesulfonic acid in the presence of magnetite nanoparticles. The composite, magnetite/SPAN(PANSA) was characterized by means of transmission electron microscopy (TEM), X-ray diffraction (XRD), elemental analysis (EA), Fourier transform infrared (FT-IR) spectra, UV-vis spectroscopy, thermogravimetric analysis (TGA), conductivity and magnetic properties measurements. TEM image shows that magnetite nanoparticles were finely distributed into the SPAN matrix. XRD pattern of the nanocomposite reveals the presence of additional crystalline order through the appearance of a sharp peak at ,43° and 71°. Conductivity of the nanocomposite (0.23,S/cm) is much higher than pristine copolymer (1.97,×,10,2,S/cm). The results of FT-IR and UV-visible spectroscopy reveal the presence of molecular level interactions between SO groups in SPAN and magnetite nanoparticles in the composite. Copyright © 2006 John Wiley & Sons, Ltd. [source] Effect of Oscillating Sheath on Near-Wall Electron Current Profile in Hall ThrustersCONTRIBUTIONS TO PLASMA PHYSICS, Issue 9-10 2008D. R. Yu Abstract The radial profile of the axial electron current in Hall thrusters was measured; however, the significant decay of the current density peak in the near-wall region can't be explained effectively by the steady sheath theory. As the sheath exhibits an oscillating character when the thruster is in operation, its effect on the near-wall current profile has been studied in this paper. To obtain a comprehensive knowledge, we have considered a wide sheath oscillation frequency span which includes two asymptotic frequency cases at high and low ends. Based on the case studied, either an analytical treatment or a numerical simulation is applied. The results show that the current density peak has a fastest damping speed away from the wall at the asymptotic low frequency. With the increase of the frequency, both the decay and the spatial "wavelength" of the current profile decrease. The decay finally disappears at the asymptotic high frequency with a constant spatial "wavelength". Moreover, the sheath oscillation amplitude can enhance the decay and enlarge the spatial "wavelength". Taking into account of the realistic situation in Hall thrusters, the significant impact of the oscillating sheath on the near-wall electron current profiles can be anticipant. (© 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] LIFE SPAN OFFENDING TRAJECTORIES OF A DUTCH CONVICTION COHORT,CRIMINOLOGY, Issue 4 2005ARJAN A.J. BLOKLAND The aim of this paper is to describe the development of criminal behavior from early adolescence to late adulthood based on conviction data for a sample of Dutch offenders. Measuring over an age span of 12 to 72, we ask whether there is evidence for (1) criminal trajectories that are distinct in terms of time path, (2) a small group of persistent offenders, (3) criminal trajectories that are distinct in the mix of crimes committed, or, more specifically, persistent offenders disproportionately engaging in violent offences, and (4) different offender groups having different social profiles in life domains other than crime. The analysis is based on the conviction histories of the Dutch offenders in the Criminal Career and Life Course Study. Four trajectory groups were identified using a semi-parametric, group-based model: sporadic offenders, low-rate desisters, moderate-rate desisters and high-rate persisters. Analyses show that high-rate persisters engage in crime at a very substantial rate, even after age 50. Compared to other trajectory groups the high-rate persistent trajectory group disproportionately engages in property crimes rather than violent crimes. Also, these distinct trajectories are found to be remarkably similar across age cohorts. [source] Patterns of precursor behaviors in the life span of a U.S. environmental terrorist groupCRIMINOLOGY AND PUBLIC POLICY, Issue 3 2009Brent L. Smith Research Summary This article discusses the paucity of data available for assessing the "life span" of a terrorist group. It introduces a new methodology that allows researchers to examine when terrorist groups perform their preincident activities. The findings suggest that differences exist in the temporal patterns of terrorist groups: environmental terrorist groups engage in a relatively short planning cycle compared with right-wing and international terrorists. The article concludes by examining a case study on "the Family," which is a unique environmental terrorist group that conducted activities over a relatively long period of time. This group provides an interesting contrast to other environmental terrorists. Despite significant organizational differences, their patterns of preparatory conduct were highly similar. Policy Implications The findings suggest that (1) temporal and spatial data about preincident terrorist activity can be collected from unclassified and open sources and (2) law-enforcement agencies that are investigating environmental groups have relatively little time to observe and infiltrate their individual cells (compared with right-wing and international terrorists). Finally, the data suggest that environmental terrorists,at least so far,have engaged in attacks that are less deadly than the comparison groups. [source] Requirement for ,B1-crystallin promoter of Xenopus laevis in embryonic lens development and lens regenerationDEVELOPMENT GROWTH & DIFFERENTIATION, Issue 3 2005Nobuhiko Mizuno Regulation of the lens-specific ,B1-crystallin promoter in Xenopus laevis was investigated using transgenic larvae and tadpoles. Comparison of the promoter sequence with that of chicken ,B1-crystallin gene indicates significant sequence similarity over a span of several hundred base pairs starting from the transcriptional start site. Remarkably, PL-1 and PL-2 sequences identified in the chicken promoter as essential binding sites of MAF, Pax6 and Prox1 transcription factors were conserved. Mutations of X (Xenopus) PL-1 and XPL-2 sequences eliminated the promoter activity, indicating a conserved mechanism regulating ,B1-crystallin promoter among vertebrate species. A stepwise deletion of the promoter sequence starting from 2800 bp indicated that the proximal 260 bp directly upstream of the transcription initiation site is sufficient for eliciting lens-specific expression, but the 150 bp promoter sequence is inactive despite it containing the XPL-1 and XPL-2 sequences, suggesting the presence of an additional and essential regulatory sequence located between ,150 and ,260 bp. Activity of the ,B1-crystallin promoter during lens regeneration from cornea was examined using transgenic tadpoles and found to have the same dependence on promoter regions as in embryonic lens development, indicating that gene regulation is largely shared by the two lens-generating processes. [source] | ||||||||||||||||||||||||||||||||||||||||||||||||||||