bluuebunny/crossref_metadata_2025 huggingface dataset:
Determination of trace manganese and Ni in neem oil by ETA‐AAS with emulsion sample introduction
Authors: Benzo Z. , Zoltan T. , Murillo M. , Quintal M. , Salas J. , Marcano E. , Gómez C.
Published: November 2006

An emulsion‐based method was developed as an alternative for the introduction of oil‐based samples into a graphite furnace to produce a more rapid, precise, and accurate method of analysis. The combination of emulsion sampling and electrothermal atomization for atomic absorption spectroscopy was developed and then applied to the determination of Ni and manganese in neem oil from Venezuela. The optimal concentration of neem oil in the emulsion was 30 and 4% for Ni and Mn, respectively, based on the metal concentration of the neem oil. The stability of the emulsion as a function of time was evaluated. The use of aqueous calibration solutions and the accuracy attained using this method make it attractive for the analysis of oil samples. The metal recovery was between 97 and 101%. Based on the emulsion method, the neem oil samples had 1.39 and 0.21 mg of Mn and Ni per kg of oil, respectively. The wet digestion method indicated a Mn and Ni concentration in the neem oil sample of 1.42 and 0.24 mg/kg, respectively.
Phase‐equilibrium modeling in the hydrogenation of vegetable oils and derivatives
Authors: Pereda Selva , Rovetto Laura , Bottini Susana B. , Brignole Esteban A.
Published: November 2006

The main tool needed to carry out phase‐equilibrium engineering of a given process is an adequate thermodynamic model adjusted to the range of process operating conditions of the working system. In the present work the Group Contribution with Association Equation of State (GCA‐EoS) is used to model the phase behavior of reacting mixtures typical of the hydrogenation of vegetable oils and derivatives at supercritical or high‐pressure conditions.
Polymorphism and growth behavior of low‐trans fat blends formulated with and without emulsifiers
Authors: Cerdeira Marina , Martini Silvana , Candal Roberto J. , Herrera María L.
Published: November 2006

Polymorphism and growth behavior of blends of a high‐melting fraction of milk fat (HMF) and sunflower oil (SFO) formulated with and without the addition of sucrose esters (SE) P‐170, P‐1670, and S‐170 were studied by pulsed 1H NMR spectroscopy, X‐ray diffraction, and polarized light microscopy. The effect of SE on the solid content maximum (Smax) or crystallization rate was observed only at low supercooling (values of ΔT below 15°C). The Avrami kn decreased as n values increased, indicating that SE inhibited growth and impeded nucleation. Addition of SFO modified the polymorphic behavior of milk fat, most likely owing to the increase in the C54 fraction (mostly 18∶1 cis) in crystals composition. P‐170 and S‐170 modified the polymorphic behavior of HMF when it crystallized in the α‐form or in blends with up to 40% SFO at all crystallization temperatures (Tc) selected. Addition of P‐170 and S‐170 favored crystallization in the β′‐form, and the appearance of the β‐form was delayed. P‐1670 had no effect on polymorphism. When HMF and the blends were crystallized under dynamic conditions, addition of P‐170 and S‐170 markedly decreased crystal sizes. P‐1670, however, showed no effect on microstructure.
Phase behavior of model lipid systems: Solubility of high‐melting fats in low‐melting fats
Authors: Zhou Yuqing , Hartel Richard W.
Published: November 2006

The solubility behavior of three high‐melting fats (tripalmitin sample, PPP‐S; cocoa butter‐stearin, CB‐S; and palm oil‐stearin, PO‐S) in five low‐melting fats (tricaprylin, CCC; canola oil; sunflower oil; lard‐olein, LD‐O; and palm oil‐olein, PO‐O) was studied. To create the solubility curve, the high‐melting fat was first equilibrated in the low‐melting model lipid system between 25 and 62.5°C for 1 wk. The amount of high‐melting fat dissolved in the low‐melting model lipid system was then determined by analyzing TAG compositions in the liquid phase using GC. The low‐melting CCC formed partial solid solutions with each of the high‐melting fats as a result of its very short chain length. PPP‐S formed an ideal solution in all of the low‐melting fats except CCC. The mixtures of CB‐S/LD‐O, CB‐S/PO‐O, and PO‐S/LD‐O deviated from ideality, illustrating closer interactions between TAG from CB‐S and PO‐S and those from LD‐O or PO‐O. The melting temperature and heat of fusion of the high‐melting fats calculated from the Hildebrand equation was very close to those determined by DSC.
Frying quality and oxidative stability of two unconventional oils
Authors: Mariod Abdalbasit , Matthäus Bertrand , Eichner K. , Hussein Ismail H.
Published: November 2006

The behavior of crude Sclerocarya birrea kernel oil (SCO) and Sorghum bug (Agonoscelis pubescens) oil (SBO) during deep‐frying of par‐fried potatoes was studied with regard to chemical, physical, and sensory parameters, such as content of FFA, tocopherols, polar compounds, oligomer TG, volatile compounds, oxidative stability, and total oxidation (TOTOX) value. Palm olein was used for comparison. Whereas potatoes fried in SCO that had been used for 24 h of deep‐frying at 175°C were still suitable for human consumption, potatoes prepared in SBO that had been used for 6 to 12 h were not, considering the sensory evaluation. In looking at the chemical and physical parameters, SBO exceeded the limits, after no later than 18 h of use, for the amount of polar compounds, oligomer TG, and FFA recommended by the German Society of Fat Sciences (DGF) as criteria for the rejection of used frying oils. In contrast to SBO, SCO oil did not exceed the limits for the content of polar compounds and oligomer TG during the frying experiment. Only the amount of FFA was exceeded; this was because the amount of FFA at the beginning of the experiment was higher than for refined oils. The results showed that both oils were suitable for deep‐frying of potatoes, but remarkable differences in the time during which both oils produced palatable products were found.
Isolation and melting properties of branched‐chain esters from lanolin
Authors: Yao Linxing , Hammond Earl G.
Published: November 2006

Saturated branched FA and their derivatives are both biodegradable and stable to oxidation. Their m.p. are expected to be enough lower than their straight‐chain counterparts to make them ideal as biolubricants. But physical property data for branched fatty esters are limited. In this study, a complex mixture of branched methyl esters was obtained from lanolin through saponification, extraction of unsaponifiables, and methylation. Hydroxy compounds were removed by chromatography on alumina. Vacuum spinning‐band distillation separated the mixture roughly by chain length. Countercurrent urea complex formation and low‐temperature crystallization separated even‐chain iso‐and odd‐chain anteiso‐methyl esters of chain lengths 14 through 18 at >95% purity. Transesterification was used to convert methyl esters to isopropyl esters. The m.p. and heat of fusion of each ester were determined by DSC. NMR was used to verify the structure of branched esters.
Viscoelastic properties of lupin proteins produced by ultrafiltration‐diafiltration
Authors: Xu Jingyuan , Mohamed Abdellatif A. , Hojilla‐Evangelista Mila P. , Sessa David J.
Published: November 2006

The linear and nonlinear rheological properties of defatted lupin proteins produced by ultrafiltration‐diafiltration were investigated. Five concentrations ranging from 10 to 30% of the defatted ultrafiltered‐diafiltered (DUD) lupin proteins were prepared. The viscoelastic properties strongly depended on concentrations. Below 12%, the DUD lupin proteins exhibited more fluid‐like behavior. At 15%, lupin proteins became more viscoelastic, and above 20%, the viscoelastic solid‐like properties became stronger. Below 12%, the high‐frequency behaviors of moduli were proportional to ω1/2, as expected for a semiflexible coil. Above 20%, the high‐frequency behaviors of moduli were proportional to ω1/2, indicating a flexible coil. The nonlinear steady shear rheological properties were also concentration‐dependent and showed shear‐thinning behavior, which could be described by a power law constitutive model. The trend of the power law exponent shift is very consistent with the linear viscoelastic behavior change with the lupin protein concentration. These results suggest DUD lupin proteins undergo a structural change between 12 and 20%.
Diastolic dysfunction and autonomic abnormalities in patients with systolic heart failure
Authors: Stein Phyllis K. , Tereshchenko Larisa , Domitrovich Peter P. , Kleiger Robert E. , Perez Alfonso , Deedwania Prakash
Published: November 2006

Background

Patients with systolic heart failure (SHF) often have concomitant diastolic dysfunction (DD). SHF is associated with decreased heart rate variability (HRV), but the impact of degree of DD on HRV in SHF is unclear.

Methods and results

HRV was measured in 139 patients, aged 64±12 years, 74% male, LVEF 30±8%. Patients had stable NYHA class II–III CHF on ACE inhibitors or ATII receptor blockers, with LVEF≤40% and BNP≥200 pg/ml. Subjects underwent 2‐D echocardiography with Doppler assessment and 24‐h Holters. Patients were categorized as having impaired relaxation (E‐deceleration time>2 SD above age‐adjusted normal values (AANV), E/A≤1, systolic/diastolic pulmonary vein flow≥1; N=30), pseudonormal (E‐deceleration time within 2 SD of AANV, E/A=1–2, systolic/diastolic pulmonary vein flow <1 N=25) or restrictive filling patterns (E‐deceleration time>2 SD below AANV or/and E/A ratio≥2; N=84) Differences were adjusted for clinical covariates using UNIANOVA, p<0.05. HRV was reduced and BNP higher in pseudonormal patients compared to impaired relaxation, but this difference was only significant for restrictive vs. impaired filling. Differences remained significant after adjustment for covariates.

Conclusion

Significantly more abnormal HRV, reflecting greater cardiac autonomic dysfunction, is associated with restrictive DD compared to impaired relaxation.
Self‐reported pain sensitivity: Lack of correlation with pain threshold and tolerance
Authors: Edwards Robert R. , Fillingim Roger B.
Published: November 2006

Many recent studies and several reviews have highlighted the potential clinical applications of experimental pain testing (e.g., for predicting post‐surgical pain, treatment responsiveness, etc.). However, the implementation of quantitative sensory testing of pain sensitivity on a broad scale is limited by requirements of time, equipment, and expertise, and their associated costs. One reasonable question is whether one can obtain, via self‐report, a valid index of an individual's pain sensitivity and pain tolerance. We analyzed data from a large number of subjects (n=505) who had undergone standardized thermal pain testing, and found that while higher self‐reported pain sensitivity was associated with higher scores on a measure of anxiety, no relationship was observed between subjects’ self‐report of pain sensitivity and subjects’ actual pain threshold or tolerance. These findings suggest that circumventing psychophysical pain testing by assessing individuals’ self‐reported pain sensitivity is unlikely to be a useful strategy.
The polyamine spermine protects against high salt stress in Arabidopsis thaliana
Authors: Yamaguchi Koji , Takahashi Yoshihiro , Berberich Thomas , Imai Akihiko , Miyazaki Atsushi , Takahashi Taku , Michael Anthony , Kusano Tomonobu
Published: November 2006

It is well known that changes in abiotic conditions such as the concentration of ions, temperature and humidity lead to modulation of polyamine contents in plants. However, little is known about the relevant parts these polyamines play in abiotic stress responses. Here we addressed a specific role of spermine during high salt stress using an Arabidopsis double knockout‐mutant plant (acl5/spms) which cannot produce spermine. The mutant showed higher sensitivity to high salt than wild type plants. This phenotype was cured by exogenous spermine but not by the other polyamines putrescine and spermidine, suggesting a strong link between spermine‐deficiency and NaCl‐hypersensitivity. The mutant was also hypersensitive to high levels of KCl but not to MgCl2 or to high osmoticum. NaCl‐hypersensitivity of the mutant was compromised by treatment with Ca2+ channel blockers. Moreover, the mutant showed poor growth on Ca2+‐depleted Murashige–Skoog agar media. The data suggest that the absence of spermine causes an imbalance in Ca2+ homeostasis in the mutant plant. Based on the data obtained, we propose a model for a role of spermine in high salt stress responses.
Augmentation of 11β‐hydroxysteroid dehydrogenase type 1 in LPS‐activated J774.1 macrophages – Role of 11β‐HSD1 in pro‐inflammatory properties in macrophages
Authors: Ishii Takako , Masuzaki Hiroaki , Tanaka Tomohiro , Arai Naoki , Yasue Shintaro , Kobayashi Nozomi , Tomita Tsutomu , Noguchi Michio , Fujikura Junji , Ebihara Ken , Hosoda Kiminori , Nakao Kazuwa
Published: November 2006

Macrophage infiltration in obese adipose tissue provokes local inflammation and insulin resistance. Evidence has accumulated that activation of 11β‐HSD1 in adipocytes is critically involved in dysfunction of adipose tissue. However, the potential role of 11β‐HSD1 in macrophages still remains unclear. We here demonstrate that a murine macrophage cell line, J774.1 cells expressed 11β‐HSD1 mRNA and reductase activity, both of which were augmented by lipopolysaccharide (LPS)‐induced cell activation. Three kinds of pharmacological inhibition of 11β‐HSD1 in LPS‐treated macrophages significantly suppressed the expression and secretion of interleukin 1β, tumor necrosis factor α or monocyte chemoattractant protein 1, thereby highlighting a novel role of 11β‐HSD1 in pro‐inflammatory properties of activated macrophages.
Differential responses of normal human coronary artery endothelial cells against multiple cytokines comparatively assessed by gene expression profiles
Authors: Miura Aya , Honma Reiko , Togashi Takushi , Yanagisawa Yuka , Ito Emi , Imai Jun-ichi , Isogai Takao , Goshima Naoki , Watanabe Shinya , Nomura Nobuo
Published: November 2006

Endothelial cells play an important role in terms of biological functions by responding to a variety of stimuli in the blood. However, little is known about the molecular mechanism involved in rendering the variety in the cellular response. To investigate the variety of the cellular responses against exogenous stimuli at the gene expression level, we attempted to describe the cellular responses with comprehensive gene expression profiles, dissect them into multiple response patterns, and characterize the response patterns according to the information accumulated so far on the genes included in the patterns. We comparatively analyzed in parallel the gene expression profiles obtained with DNA microarrays from normal human coronary artery endothelial cells (HCAECs) stimulated with multiple cytokines, interleukin‐1β, tumor necrosis factor‐α, interferon‐β, interferon‐γ, and oncostatin M, which are profoundly involved in various functional responses of endothelial cells. These analyses revealed that the cellular responses of HCAECs against these cytokines included at least 15 response patterns specific to a single cytokine or common to multiple cytokines. Moreover, we statistically extracted genes contained within the individual response patterns and characterized the response patterns with the genes referring to the previously accumulated findings including the biological process defined by the Gene Ontology Consortium (GO). Out of the 15 response patterns in which at least one gene was successfully extracted through the statistical approach, 11 response patterns were differentially characterized by representing the number of genes contained in individual criteria of the biological process in the GO only. The approach to dissect cellular responses into response patterns and to characterize the pattern at the gene expression level may contribute to the gaining of insight for untangling the diversity of cellular functions.
Cyclosporin A binding to Mycobacterium tuberculosis peptidyl‐prolyl cis–trans isomerase A – Investigation by CD, FTIR and fluorescence spectroscopy
Authors: Mitra Devrani , Mukherjee Somnath , Das Amit Kumar
Published: November 2006

Circular dichroism and resolution‐enhanced Fourier transform infrared reveal induction of secondary structural elements on peptidyl‐prolyl cis–trans isomerase A (PpiA) from Mycobacterium tuberculosis upon binding cyclosporin A (CsA). Thermal denaturation shows aggregation of PpiA at higher temperatures (>70 °C) and CsA fails to impart stabilization in protein structure. However, CsA stabilizes PpiA structure in urea denaturation. In presence/absence of CsA, urea‐induced reversible unfolding of secondary and tertiary structures follows two‐state and three‐state transition, respectively. The chemical unfolding results also demonstrate that loss in the tertiary structure precedes the loss in secondary structure both in presence and absence of CsA at the initial stages. Fluorescence quenching suggests presence of a positive barrier around tryptophan microenvironment of PpiA.
Fifth Metacarpal Neck Fractures: Is Follow-Up Required?
Authors: BANSAL R. , CRAIGEN M. A. C.
Published: November 2006

This study examines the premise that follow-up after fifth metacarpal neck fractures is unnecessary after initial assessment in a hand clinic. Forty consecutive patients with this fracture were managed in plaster and followed up. The next 38 patients were treated with neighbour strapping, given information sheets and no follow-up visits were arranged. In the first group, most return visits were for removal of plaster. Almost half of the appointments, thereafter, were not attended. In the second group, only two patients returned to the clinic, one with minor complaints and one with a repeat injury. Patients reported better satisfaction when managed with neighbour strapping ( P = 0.04) and without regular follow-up visits ( P< 0.01). The time to return to work was a mean of 5 weeks and 2.7 weeks in the first and second groups, respectively ( P< 0.01). There was no significant difference in the functional outcome at 12 weeks, as assessed by the DASH score.
Socio-economic and psychological correlates of suicidality among Hong Kong working-age adults: results from a population-based survey
Authors: LIU KA Y. , CHEN ERIC Y. H. , CHAN CECILIA L. W. , LEE DOMINIC T. S. , LAW Y. W. , CONWELL YEATES , YIP PAUL S. F.
Published: November 2006

Background. The global toll of suicide is estimated to be one million lives per year, which exceeded the number of deaths by homicide and war combined. A key step to suicide prevention is to prevent less serious suicidal behaviour to preclude more lethal outcomes. Although 61% of the world's suicides take place in Asia and the suicide rates among middle age groups have been increasing since the economic crisis in many Asian countries, population-based studies of suicidal behaviour among working-age adults in non-western communities are scarce.

Method. Data from a population-based survey with 2015 participants were used to estimate the prevalence of suicidal ideation and behaviour among the working-age population in Hong Kong, and to study the associated socio-economic and psychological correlates. We focused particularly on potential modulating factors between life-event-related factors and suicidal ideation.

Results. Six per cent of the Hong Kong population aged 20–59 years considered suicide in the past year, while 1·4% attempted suicide. Hopelessness, reasons for living, and reluctance to seek help from family and friends had direct association with past-year suicidal ideation. Reasons for living were found to moderate the effect of perceived stress on suicidal ideation.

Conclusions. Suicidality is a multi-faceted problem that calls for a multi-sectored, multi-layered approach to prevention. Prevention programmes can work on modulating factors such as reasons for living to reduce suicidal risk in working-age adults.
Potential of ozone formation by the smog mechanism to shield the surface of the early Earth from UV radiation
Authors: Grenfell John Lee , Stracke Barbara , Patzer Beate , Titz Ruth , Rauer Heike
Published: November 2006

We propose that the photochemical smog mechanism produced substantial ozone (O3) in the troposphere during the Proterozoic period, which contributed to ultraviolet (UV) radiation shielding, and hence favoured the establishment of life. The smog mechanism is well established and is associated with pollution hazes that sometimes cover modern cities. The mechanism proceeds via the oxidation of volatile organic compounds such as methane (CH4) in the presence of UV radiation and nitrogen oxides (NOx). It would have been particularly favoured during the Proterozoic period given the high levels of CH4 (up to 1000 ppm) recently suggested. Proterozoic UV levels on the surface of the Earth were generally higher compared with today, which would also have favoured the mechanism. On the other hand, Proterozoic O2 required in the final step of the smog mechanism to form O3 was less abundant compared with present times. Furthermore, results are sensitive to Proterozoic NOx concentrations, which are challenging to predict, since they depend on uncertain quantities such as NOx source emissions and OH concentrations. We review NOx sources during the Proterozoic period and apply a photochemical box model having methane oxidation with NOx, HOx and Ox chemistry to estimate the O3 production from the smog mechanism. Runs suggest the smog mechanism during the Proterozoic period can produce approximately double the present-day ozone columns for NOx levels of 1.53×10−9 by volume mixing ratio, which was attainable according to our NOx source analysis, with 1% of the present atmospheric levels of O2. Clearly, forming ozone in the troposphere is a trade-off for survivability – on the one hand, harmful UV radiation is blocked, but on the other hand ozone is a respiratory irratant, which becomes fatal at concentrations exceeding about 1 ppmv.
Damped regional‐scale stress inversions: Methodology and examples for southern California and the Coalinga aftershock sequence
Authors: Hardebeck Jeanne L. , Michael Andrew J.
Published: November 2006

We present a new focal mechanism stress inversion technique to produce regional‐scale models of stress orientation containing the minimum complexity necessary to fit the data. Current practice is to divide a region into small subareas and to independently fit a stress tensor to the focal mechanisms of each subarea. This procedure may lead to apparent spatial variability that is actually an artifact of overfitting noisy data or nonuniquely fitting data that does not completely constrain the stress tensor. To remove these artifacts while retaining any stress variations that are strongly required by the data, we devise a damped inversion method to simultaneously invert for stress in all subareas while minimizing the difference in stress between adjacent subareas. This method is conceptually similar to other geophysical inverse techniques that incorporate damping, such as seismic tomography. In checkerboard tests, the damped inversion removes the stress rotation artifacts exhibited by an undamped inversion, while resolving sharper true stress rotations than a simple smoothed model or a moving‐window inversion. We show an example of a spatially damped stress field for southern California. The methodology can also be used to study temporal stress changes, and an example for the Coalinga, California, aftershock sequence is shown. We recommend use of the damped inversion technique for any study examining spatial or temporal variations in the stress field.
Breaking waves over a mild gravel slope: Experimental and numerical analysis
Authors: Lara Javier L. , Losada Inigo J. , Liu Philip L.‐F.
Published: November 2006

An experimental and numerical study of the effects of a gravel slope on wave shoaling and breaking is presented herein. In the laboratory experiments, fluid velocities, pressure and water surface elevations were measured. Experiments were conducted for both spilling and plunging breakers and for gravel slopes with different gravel sizes. Since gravel slopes caused additional energy dissipation, wave heights in the shoaling zone as well as at the breaking point were reduced. On the other hand, the mean free surface setup inside the surf zone increased. It was also observed that the gravel slope had a stronger influence on the vertical profile of undertow under spilling breaker than on that under a plunging breaker. Moreover, the undertow became weaker over a gravel slope with a larger gravel size. Outside the surf zone, turbulent velocities near the gravel slope were relatively high because of the bottom roughness and percolation. Inside the surf zone, turbulence generated by wave breaking dominated over the gravel bed generated turbulence. The vertical flow induced by the gravel slope changed the turbulence pattern only at cross sections very close to the shoreline. Numerical simulations of the wave breaking processes over a gravel slope were performed. The numerical model was tested by comparing numerical results with experimental data. The model accurately simulated the mean flow quantities. The magnitude of turbulence and turbulence characteristics were also simulated reasonably well.
Identification of potential sources and source regions of fine ambient particles measured at Gosan background site in Korea using advanced hybrid receptor model combined with positive matrix factorization
Authors: Han J. S. , Moon K. J. , Kim Y. J.
Published: November 2006

The size‐ and time‐resolved measurement of particulate trace elements was made using an eight‐stage Davis Rotating Unit for Monitoring sampler and synchrotron X‐ray fluorescence system from 29 March to 29 May in 2002 at Gosan, Korea, which is one of the representative background sites in east Asia. As a result, continuous 3‐hour average concentrations were obtained for 19 elements including S, Si, Al, Fe, Ca, Cl, Cu, Zn, Ti, K, Mn, Pb, Ni, V, Se, As, Rb, Cr, and Br. Positive matrix factorization (PMF) method was applied to the size‐resolved aerosol data sets in order to identify the possible sources and to estimate their contribution to particulate matter mass in each size range. Twelve sources were then resolved in the fine size range (0.07 ∼ 1.15 μm), including continental aerosol, biomass burning, coal combustion, oil heating furnace, residual oil fired boiler, municipal incineration, nonferrous metal source, ferrous metal source, gasoline vehicle, diesel vehicle, copper smelter, and volcanic emission. A newly developed hybrid receptor model, concentration, retention time, and source emission weighted trajectory (CRSWT), was then applied to the source intensities derived from the PMF analysis by incorporating meteorological and source inventory information of the study region in order to suggest the regional information of long‐range transported fine aerosol sources. The CRSWT model was able to resolve highly potential source areas and pathways for the fine ambient aerosol at the Gosan background site.
Tropospheric and stratospheric BrO columns over Arrival Heights, Antarctica, 2002
Authors: Schofield R. , Johnston P. V. , Thomas A. , Kreher K. , Connor B. J. , Wood S. , Shooter D. , Chipperfield M. P. , Richter A. , von Glasow R. , Rodgers C. D.
Published: November 2006

Spectroscopic measurements of BrO using direct sun and zenith sky viewing geometries are combined in an optimal estimation retrieval algorithm to obtain tropospheric and stratospheric columns of BrO. Twenty‐two twilight periods are investigated over Arrival Heights, Antarctica (77.8°S, 166.7°E) during the polar spring period of 2002. This paper presents the first tropospheric and stratospheric BrO column retrievals from UV‐visible ground‐based measurements for a polar location. A direct comparison is made between stratospheric columns retrieved at 80°, 84°, and 88° solar zenith angles (SZA) from the spectroscopic measurements and those calculated by the SLIMCAT three‐dimensional chemical transport model. The ground‐based column BrO observations are consistent with a SLIMCAT stratospheric Bry loading of 21.2 parts per trillion at 20 km. SLIMCAT reproduces the observed sunrise column BrO increase but does not match the sunset observations, which display less variation. The significant warming of the Antarctic polar stratosphere in 2002 led to highly variable stratospheric columns being observed. The observed column BrO decreased with the transition from vortex to extravortex air on 21 September but did not change much following the return of the vortex on 12 October. For the tropospheric column, an almost normal distribution consistent with a “background” of 0.3 ± 0.3 × 1013 molecules cm−2 is observed from the ground (80°, 84°, and 88° for both sunrise and sunset). A statistically significant “bromine explosion” event (at the 2σ level) was detected at the end of October with a tropospheric column of 1.8 ± 0.1 × 1013 molecules cm−2. The measured tropospheric columns are compared with the tropospheric Model of Atmospheric Transport and Chemistry–Max Planck Institute for Chemistry version model. The tropospheric BrO sunrise column observations can only be explained with an additional bromine source other than decomposition of CH3Br and downward transport of long‐lived bromine from the stratosphere. A comparison with the spaceborne Global Ozone Monitoring Experiment (GOME) found the total columns observed from the ground to be 16–25% smaller than the total columns observed by GOME for SZAs between 80° and 88°.
Tarapacá intermediate‐depth earthquake (Mw 7.7, 2005, northern Chile): A slab‐pull event with horizontal fault plane constrained from seismologic and geodetic observations
Authors: Peyrat S. , Campos J. , de Chabalier J. B. , Perez A. , Bonvalot S. , Bouin M.‐P. , Legrand D. , Nercessian A. , Charade O. , Patau G. , Clévédé E. , Kausel E. , Bernard P. , Vilotte J.‐P.
Published: November 2006

A large (Mw 7.7) intermediate‐depth earthquake occurred on 13 June 2005 in the Tarapacá region of the northern Chile seismic gap. Source parameters are inferred from teleseismic broadbands, strong motions, GPS and InSAR data. Relocated hypocenter is found at ∼98 km depth within the subducting slab. The 21‐days aftershock distribution, constrained by a postseismic temporary array, indicates a sub‐horizontal fault plane lying between the planes of the double seismic zone and an upper bound of the rupture area of 60 km × 30 km. Teleseismic inversion shows a slab‐pull down dip extension mechanism on a nearly horizontal plane. Total seismic and geodetic moments are ∼5.5 × 1020 N.m, with an averaged slip of 6.5 m from geodesy. The earthquake rupture is peculiar in that the effective velocity is slow, 3.5 Km.s−1 for a high stress‐drop, 21–30 MPa. We propose that rupture was due to the reactivation by hydraulic embrittlement of a inherited major lithospheric fault within the subducting plate. The stress‐drop suggests that the region of the slab between planes of the double seismic zone can sustain high stresses.
Simulations of the scintillation‐producing irregularities in high‐latitude plasma patches
Authors: Gondarenko N. A. , Guzdar P. N.
Published: November 2006

The simulation study of mesoscale scintillation‐producing irregularities obtained with the 3‐D nonlinear model for the structuring by the gradient‐drift instability (GDI) and the velocity‐shear‐driven instability in high‐latitude plasma patches is presented. We have identified four groups of mesoscale structures based on the structuring mechanisms. The amplitudes of the scintillation‐producing irregularities have been described with a normalized irregularity index which is proportional to the scintillation index S4 and accounts for the greatest variability in ionospheric scintillation. We have demonstrated that the dominant mechanism which can lead to intense scintillation is related to the patch structuring by the primary GDI and high plasma density in a patch. In the velocity shear simulations, the values of the irregularity index are found to be weaker than those produced in the simulations with no shear. The relations between the magnitudes of the simulated electric field and density irregularities have been derived for each category.
Long‐term (105 years) variability in rain erosivity as derived from 10‐min rainfall depth data for Ukkel (Brussels, Belgium): Implications for assessing soil erosion rates
Authors: Verstraeten Gert , Poesen Jean , Demarée Gaston , Salles Christian
Published: November 2006

A 10‐min rainfall depth time series recorded at Ukkel, Brussels (Belgium) for the period 1898–2002 was used to calculate a long‐term rain erosivity record. The rain erosivity factor (R factor) of the Revised Universal Soil Loss Equation (RUSLE) for the period 1898–2002 equals 871 MJ mm ha−1 h−1 yr−1, based on a newly developed rain intensity–kinetic energy equation (I‐KE) for central Belgium. This R value is 26% larger compared to the R factor based on the I‐KE equation recommended in the RUSLE. No significant monotonic trend in annual R factor could be observed over the entire period, yet a standard normal homogeneity test showed a significantly higher R factor (+31%) for the period 1991–2002 compared to the period 1898–1990. Annual variability in R factor is very high, with a coefficient of variance of 31%. For central Belgium, rain erosivity is highest in the period May–September, which corresponds well with observed soil loss rates and the occurrence of muddy floods. Especially the period May–June is critical with respect to soil erosion. The year‐to‐year variability in rain erosivity for May–June shows a different temporal pattern than the annual erosivity. No statistically significant increase in rain erosivity for May–June was found, and during the last decade of the twentieth century these values are lower than average. Despite the lack of a significant trend in annual rain erosivity, average 10‐year erosion rates calculated with the RUSLE have increased by 24–34% from 1903–1912 to 1993–2002 for major crops grown in central Belgium, solely as a consequence of changing rain erosivity through time.
Impact of particle size on colloid transport in discrete fractures
Authors: Zvikelsky Ori , Weisbrod Noam
Published: November 2006

The impact of particle size on colloid transport was explored in two saturated, naturally discrete fractured chalk cores, with equivalent hydraulic apertures of 183 and 380 μm. Tracer experiments were carried out using negatively charged fluorescent latex microspheres (FluoSpheres®: 0.02, 0.1, 0.2, and 1.0 μm diameter) as well as Li+ and Br− as the soluble tracers. In both fractures, FluoSpheres exhibited earlier arrival times than the solutes and a complete lack of tails in their breakthrough curves, proving that their transport is advection‐dominant. In all experiments the 0.2‐μm FluoSpheres were recovered to a much greater extent than the 0.02‐μm FluoSpheres and to a slightly greater extent than the 1.0‐μm FluoSpheres. Similarly, the highest maximum C/C0 values were found for 0.2 μm, then for 1.0 μm, while the maximum C/C0 values for the 0.02‐μm colloids were significantly lower. The insignificant contribution of settling relative to Brownian motion (diffusion) as an efficient deposition mechanism was demonstrated for all sizes of FluoSpheres in both fractures.
Estimating mass discharge from dense nonaqueous phase liquid source zones using upscaled mass transfer coefficients: An evaluation using multiphase numerical simulations
Authors: Christ John A. , Ramsburg C. Andrew , Pennell Kurt D. , Abriola Linda M.
Published: November 2006

Difficulties associated with identifying the dense nonaqueous phase liquid (DNAPL) source zone architecture at the field scale, combined with the computational costs of field‐scale DNAPL dissolution simulations, have motivated the development of a number of simplified models that rely upon upscaled (i.e., domain‐averaged) mass transfer coefficients to approximate field‐scale dissolution processes. While conceptually attractive, these upscaled models have yet to be fully evaluated for prediction of mass recovery from a range of nonuniform, three‐dimensional DNAPL source zones. This study compares upscaled model predictions of flux‐weighted downstream concentrations and source longevity to predictions derived from three‐dimensional multiphase numerical simulation of tetrachloroethene (PCE)‐NAPL dissolution for realizations of a statistically homogeneous, nonuniform aquifer. Although the functional forms of the upscaled models are generally shown to be mathematically equivalent, upscaled model flux‐weighted concentration predictions varied by over one order of magnitude, with variations attributed to the dependence of the upscaled model parameters on the specific source zone scenario used for model calibration. Replacement of upscaled model calibration parameters with source zone parameters that can be obtained from site characterization information (specifically, the initial flux‐weighted concentration and source zone ganglia‐to‐pool (GTP) mass ratio) reduced the root‐mean‐square error between upscaled and numerical model predictions by approximately 80%. Application of this modified model to a range of source zone scenarios (0.4 < GTP < ∞) demonstrates the efficacy of the model for use as a screening tool to relate DNAPL mass removal and flux‐weighted concentrations when mass removal is less than 80%.
Immunoepigenetics: the unseen side of cancer immunoediting
Authors: Germenis A E , Karanikas V
Published: November 2006

Cancer immunosurveillance representing, till recently, the explanatory framework relating cancer and the immune system, does not convincingly explain tumor escape. At the beginning of the decade, a new theory emerged, namely the immunoediting theory, and it comprehensively defines the role of the immune system in carcinogenesis. The core of this theory embraces the concept that the immune system on the one hand protects the body from cancer and on the other it shapes the immunogenicity of these cancers, thus presents a persuasive rationalization of the resistance of tumors against the immune response. With the immune system playing, in this context, such a pivotal role in shaping the tumor immune profile and in subsequent oncogenesis, it seems rather paradoxical to accept the immunocompetent host's immune system as a constant moiety. While DNA mutations of immune genes create a rather polymorphic condition, their frequency is much lower than that of other genetic events. Of these, epigenetic alterations give rise to new epialleles, which can reach up to 100% per locus. Bearing in mind that cancer is characterized by a tremendous amount of epigenetic aberrations, in both gene and global level, it is reasonable to postulate that, for the same unknown causes, analogous aberrations could affect the immune genes. Should this be the case, the relation between oncogenesis and the immune system appears much more dynamic and complex. Such an immunoepigenetic approach to carcinogenesis could improve our understanding of a series of common cancer‐related aspects, such as environmental risk factors, effectiveness of demethylating agents, failure of current immunotherapies, etc. Moreover, this immunoepigenetic paradigm will take the current perception of the immune system and cancer interrelation further and beyond, constituting that the immunoresistant cancer cell phenotype is not shaped by the immune system acting as a steady and rigid evolutionary pressure, but rather as an extremely dynamic variable.
Host and viral factors in the immunopathogenesis of primary hepatitis C virus infection
Authors: Lloyd Andrew R , Jagger Emma , Post Jeffrey J , Crooks Lee‐Ann , Rawlinson William D , Hahn Young S , Ffrench Rosemary A
Published: November 2006

Individuals infected with hepatitis C virus (HCV) have two possible outcomes of infection, clearance or persistent infection. The focus of this review is the host mechanisms that facilitate clearance. The interaction between HCV viral components and the immune system ultimately determines the balance between the virus and host. Strong evidence points to the aspects of cellular immune response as the key determinants of outcome. The recent discovery of viral evasion strategies targeting innate immunity suggests that the interferon‐α/β induction pathways are also critical. A growing body of evidence has implicated polymorphisms in both innate and adaptive immune response genes as determinants of viral clearance in individuals infected with HCV.
Role of nucleotides and phosphoinositides in the stability of electron and proton currents associated with the phagocytic NADPH oxidase
Authors: Petheő Gábor L. , Girardin Nathalie C. , Goossens Nicolas , Molnár Gergely Z. , Demaurex Nicolas
Published: November 2006

The phagocytic NADPH oxidase (phox) moves electrons across cell membranes to kill microbes. The activity of this lethal enzyme is tightly regulated, but the mechanisms that control phox inactivation are poorly understood for lack of appropriate assays. The phox generates measurable electron currents, Ie, that are associated with inward proton currents, IH. To study the inactivation of the phox and of its associated proton channel, we determined which soluble factors can stabilize Ie (induced by the addition of NADPH) and IH (initiated by small depolarizing voltage steps) in inside-out patches from PMA-activated human eosinophils. Ie decayed rapidly in the absence of nucleotides (τ≈6 min) and was maximally stabilized by the combined addition of 5 mM ATP and 50 μM of the non-hydrolysable GTP analogue GTP[S] (guanosine 5′-[γ-thio]triphosphate) (τ≈57 min), but not by either ATP or GTP[S] alone. IH also decayed rapidly and was stabilized by the ATP/GTP[S] mixture, but maximal stabilization of IH required further addition of 25 μM PI(3,4)P2 (phosphoinositide 3,4-bisphosphate) to the cytosolic side of the patch. PI(3,4)P2 had no effect on Ie and its stabilizing effect on IH could not be mimicked by other phosphoinositides. Reducing the ATP concentration below millimolar levels decreased IH stability, an effect that was not prevented by phosphatase inhibitors but by the non-hydrolysable ATP analogue ATP[S] (adenosine 5′-[γ-thio]triphosphate). Our data indicate that the assembled phox complex is very stable in eosinophil membranes if both ATP and GTP[S] are present, but inactivates within minutes if one of the nucleotides is removed. Stabilization of the phox-associated proton channel in a highly voltage-sensitive conformation does not appear to involve phosphorylation but ATP binding, and requires not only ATP and GTP[S] but also PI(3,4)P2, a protein known to anchor the cytosolic phox subunit p47phox to the plasma membrane.
Protein 4.1R self-association: identification of the binding domain
Authors: Pérez-Ferreiro Carmen M. , Lospitao Eva , Correas Isabel
Published: November 2006

Erythroid protein 4.1 (4.1R) stabilizes the spectrin–actin network and anchors it to the plasma membrane. To contribute to the characterization of non-erythroid protein 4.1R, we used sedimentation, pull-down and co-immunoprecipitation assays to investigate the ability of protein 4.1R to establish inter-/intra-molecular associations. We demonstrated that the small 4.1R isoforms of 60 kDa (4.1R60), but not the larger isoforms of 80 and 135 kDa (4.1R80 and 4.1R135), were self-associated, and that a domain contained in all 4.1R isoforms, the core region, was responsible for 4.1R self-association. Results from denaturing–renaturing experiments, in which an initially non-self-associated 4.1R80 isoform became self-associated, suggested that an initially hidden core region was subsequently exposed. This hypothesis was supported by results from pull-down assays, which showed that the core region interacted with the N-terminal end of the FERM (4.1, ezrin, radixin, moesin) domain that is present in 4.1R80 and 4.1R135 isoforms but absent from 4.1R60 isoforms. Consistently, 4.1R80 isoforms bound neither to each other nor to 4.1R60 isoforms. We propose that 4.1R60 isoforms are constitutively self-associated, whereas 4.1R80 and 4.1R135 self-association is prevented by intramolecular interactions.
Multiple forms of copper (II) co-ordination occur throughout the disordered N-terminal region of the prion protein at pH 7.4
Authors: Wells Mark A. , Jelinska Clare , Hosszu Laszlo L. P. , Craven C. Jeremy , Clarke Anthony R. , Collinge John , Waltho Jonathan P. , Jackson Graham S.
Published: November 2006

Although the physiological function of the prion protein remains unknown, in vitro experiments suggest that the protein may bind copper (II) ions and play a role in copper transport or homoeostasis in vivo. The unstructured N-terminal region of the prion protein has been shown to bind up to six copper (II) ions, with each of these ions co-ordinated by a single histidine imidazole and nearby backbone amide nitrogen atoms. Individually, these sites have micromolar affinities, which is weaker than would be expected of a true cuproprotein. In the present study, we show that with subsaturating levels of copper, different forms of co-ordination will occur, which have higher affinity. We have investigated the copper-binding properties of two peptides representing the known copper-binding regions of the prion protein: residues 57–91, which contains four tandem repeats of the octapeptide GGGWGQPH, and residues 91–115. Using equilibrium dialysis and spectroscopic methods, we unambiguously demonstrate that the mode of copper co-ordination in both of these peptides depends on the number of copper ions bound and that, at low copper occupancy, copper ions are co-ordinated with sub-micromolar affinity by multiple histidine imidazole groups. At pH 7.4, three different modes of copper co-ordination are accessible within the octapeptide repeats and two within the peptide comprising residues 91–115. The highest affinity copper (II)-binding modes cause self-association of both peptides, suggesting a role for copper (II) in controlling prion protein self-association in vivo.
TopBP1 contains a transcriptional activation domain suppressed by two adjacent BRCT domains
Authors: Wright Roni H. G. , Dornan Edward S. , Donaldson Mary M. , Morgan Iain M.
Published: November 2006

TopBP1 has eight BRCT [BRCA1 (breast-cancer susceptibility gene 1) C-terminus] domains and is involved in initiating DNA replication, and DNA damage checkpoint signalling and repair. Several BRCT-domain-containing proteins involved in mediating DNA repair have transcriptional regulatory domains, and as demonstrated for BRCA1 these regulatory domains are important in mediating the functions of these proteins. These transcriptional regulatory processes involve modification of chromatin, and recent evidence has clearly demonstrated that the ability to modify chromatin plays an important role in regulating DNA damage signalling and repair. Here we report the identification of a TopBP1 transcriptional activation domain that is rich in hydrophobic residues, interspersed with acidic amino acids, characteristics that are typical of transcriptional activation domains identified previously. Two adjacent repressor domains encoded by BRCT2 and BRCT5 silence this activator and experiments suggest that these repressors actively recruit repressor complexes. Both the activator and BRCT2 repressor domains function in yeast. The present study identifies several chromatin modification domains encoded by TopBP1, and the implications of these findings are discussed in the context of the DNA damage response and the understanding of TopBP1 function.