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Kinds of Mg Terms modified by Mg Selected AbstractsPerformance comparison of MPI and OpenMP on shared memory multiprocessorsCONCURRENCY AND COMPUTATION: PRACTICE & EXPERIENCE, Issue 1 2006Géraud Krawezik Abstract When using a shared memory multiprocessor, the programmer faces the issue of selecting the portable programming model which will provide the best performance. Even if they restricts their choice to the standard programming environments (MPI and OpenMP), they have to select a programming approach among MPI and the variety of OpenMP programming styles. To help the programmer in their decision, we compare MPI with three OpenMP programming styles (loop level, loop level with large parallel sections, SPMD) using a subset of the NAS benchmark (CG, MG, FT, LU), two dataset sizes (A and B), and two shared memory multiprocessors (IBM SP3 NightHawk II, SGI Origin 3800). We have developed the first SPMD OpenMP version of the NAS benchmark and gathered other OpenMP versions from independent sources (PBN, SDSC and RWCP). Experimental results demonstrate that OpenMP provides competitive performance compared with MPI for a large set of experimental conditions. Not surprisingly, the two best OpenMP versions are those requiring the strongest programming effort. MPI still provides the best performance under some conditions. We present breakdowns of the execution times and measurements of hardware performance counters to explain the performance differences. Copyright © 2005 John Wiley & Sons, Ltd. [source] Growth of single-grain GdBa2Cu3O7-x superconductors by top seeded infiltration and growth techniqueCRYSTAL RESEARCH AND TECHNOLOGY, Issue 3 2010Guo-Zheng Li Abstract The top seeded infiltration and growth technique (TSIG) is an effective way for the preparation of bulk REBa2Cu3O7-x (RE-123, where RE denotes rare earth) with finely dispersed RE2BaCuO5 (RE-211) particles compared to the conventional melt growth (MG) method. The nucleation temperature and the ending growth temperature are the most important parameters need to be optimized during the preparation of RE-123 bulks by the TSIG process. In this paper, the effects of these parameters on the growth of single-grain GdBa2Cu3O7-x (GdBCO) superconductors have been investigated experimentally. It is found that the temperature for the growth of single-grain GdBCO is in the region between 1040 °C and 1015 °C. In addition, the relation between growth rate and supercooling has been investigated in detail. The combined techniques of SEM and EDS were used to study the microstructure of the samples grown at different temperatures. Based on this, a two-step slow cooling method during the crystallization process is proposed for the fabrication of RE-123 bulks. Finally, the single-grain GdBCO samples of the diameters 20 mm and 30 mm were fabricated successfully by the TSIG technique, with the slow-cooling process in the temperature window 1030 °C,1020 °C for 60 h and 100 h respectively. (© 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Control of the triceps surae during the postural sway of quiet standingACTA PHYSIOLOGICA, Issue 3 2007C. D. Tokuno Abstract Aim:, The present study investigated how the triceps surae are controlled at the spinal level during the naturally occurring postural sway of quiet standing. Methods:, Subjects stood on a force platform as electrical stimuli were applied to the posterior tibial nerve when the center of pressure (COP) was either 1.6 standard deviations anterior (COPant) or posterior (COPpost) to the mean baseline COP signal. Peak-to-peak amplitudes of the H-reflex and M-wave from the soleus (SOL) and medial gastrocnemius (MG) muscles were recorded to assess the efficacy of the Ia pathway. Results:, A significant increase in the Hmax : Mmax ratio for both the SOL (12 ± 6%) and MG (23 ± 6%) was observed during the COPant as compared to the COPpost condition. The source of the modulation between COP conditions cannot be determined from this study. However, the observed changes in the synaptic efficacy of the Ia pathway are unlikely to be simply a result of an altered level of background electromyographic activity in the triceps surae. This was indicated by the lack of differences observed in the Hmax : Mmax ratio when subjects stood without postural sway (via the use of a tilt table) at two levels of background activity. Conclusions:, It is suggested that the phase-dependent modulation of the triceps surae H-reflexes during the postural sway of quiet standing functions to maintain upright stance and may explain the results from previous studies, which, until now, had not taken the influence of postural sway on the H-reflex into consideration. [source] Effects of transient muscle contractions and stretching on the tendon structures in vivoACTA PHYSIOLOGICA, Issue 2 2002K. KUBO ABSTRACT This study compared the effects of static stretching (ST) and repeated muscle contractions (CON) on the viscoelastic properties of tendon structures in vivo. Eight male subjects performed ST (passively flexed to 35 of dorsiflexion) for 5 min and 50 repetitions of isometric maximum voluntary contraction (MVC) for 3 s each with 3 s relaxation. Before and after each task, the elongation of the tendon and aponeurosis of the medial gastrocnemius muscle (MG) was directly measured by ultrasonography, while the subjects performed ramp isometric plantar flexion up to MVC, followed by a ramp relaxation. The relationship between the estimated muscle force (Fm) and tendon elongation (L) during the ascending phase was applied to a linear regression, the slope of which was defined as stiffness of the tendon structures. The percentage of the area within the Fm,L loop to the area beneath the curve during the ascending phase was calculated as an index representing hysteresis. The ST protocol significantly decreased the stiffness (,8%) and hysteresis (29%)., respectively. In contrast, the CON protocol significantly decreased the stiffness, but not the hysteresis. These results suggested that the stretching and repeated contractions would make the tendon structures more complaint, and further decreased the hysteresis of the tendon structures. [source] The motility of glioblastoma tumour cells is modulated by intracellular cofilin expression in a concentration-dependent mannerCYTOSKELETON, Issue 3 2005Celestial T. Yap Abstract The invasive behaviour of tumour cells has been attributed in part to dysregulated cell motility. Members of the ADF/Cofilin family of actin-binding proteins are known to increase microfilament dynamics by increasing the rate at which actin monomers leave the pointed end of the filament and by a filament-severing activity. As depolymerisation is a rate-limiting step in actin dynamics, ADF/Cofilins are suspected to facilitate the motility of cells. To test this, we investigated the influence of cofilin on tumour motility by transient and stably overexpressing cofilin in the human glioblastoma cell line, U373 MG. Several different methods were used to ascertain the level of cofilin in overexpressing clones and this was correlated with their rate of random locomotion. A biphasic relationship between cofilin level and locomotory rate was found. Clones that displayed a moderate amount of overproduction of cofilin were found to have increased rates of locomotion approximately linear to the overproduction of cofilin up to an optimal cofilin level of about 4.5 times that of wild type cells at which the cells were almost twice as fast. However, clones producing more than this optimal amount were found to locomote at progressively reduced speeds. Cells that overexpress cofilin have reduced stress fibres compared to control cells showing that the excess cofilin affects the actin cytoskeleton. We conclude that overexpression of cofilin enhances the motility of glioblastoma tumour cells in a concentration-dependent fashion, which is likely to contribute to their invasiveness. Cell Motil. Cytoskeleton 60:153,165, 2005. © 2005 Wiley-Liss, Inc. [source] Orofacial trauma and rugby in France: epidemiological surveyDENTAL TRAUMATOLOGY, Issue 4 2003Michèle Muller-Bolla Abstract ,,,A stratified epidemiological survey was carried out among the best French rugby players to assess the prevalence of trauma to the lower or middle part of the face (TLMPF) and the frequency at which the mouthguards (MGs) were worn. The 1140 randomized players (elite 1, elite 2 and national 1 clubs) filled in the same form anonymously. The variables were first subjected to univariate analysis (Chi-square, anova). Secondly, they were included in a multivariate model (logistic regression). Some 29.57% of players had already been affected by a TLMPF. The risk increased for the oldest forward players. It also increased with the number of yearly competitions and number of hours of weekly training. Some 64.3% of players used a MG. The frequency at which it was worn increased with the number of yearly competitions, for those who had experinced a previous trauma and for the pack players who had been playing for a long time. [source] Use of mouthguards by basketball players in Victoria, AustraliaDENTAL TRAUMATOLOGY, Issue 4 2003Helen Cornwell Abstract ,,,Basketball is a popular sport in Australia. Although orofacial injuries are common, mouthguard (MG) wear in basketball appears to be low. The purposes of this study were: to measure mouthguard wear by basketball players before and after a promotional intervention; to assess players' knowledge of the value of mouthguards for prevention of injury; and to describe their experience of orofacial injury. Two questionnaires (baseline and follow-up) were administered to a convenience sample of 496 basketball players in Victoria, Australia. Players recruited were youths (12,15-year olds, n = 208) and adults (18 years and over, n = 288), from all basketball levels (social to elite). Completion of the baseline questionnaire was followed immediately by an intervention comprising written and verbal information, a mouthguard blank and instructions on mouthguard construction. The follow-up questionnaire was mailed to all respondents 10,12 weeks later; 135 youths (65%) and 157 adults (54%) completed this. Mouthguard wear at baseline was low but was more frequent at games (62%) than at training (25%). Despite 90% of players acknowledging the protective value of a mouthguard, wear by youths did not increase following the intervention, and wear by adults increased by only 14% for training and 10% at games. Previous orofacial injury was recorded at baseline by 23% of players, but few had requested compensation from Basketball Australia (youths, 17%; adults, 30%). Two predictor variables were statistically identified as related to mouthguard wear: previous orofacial injury and age group. Mouthguard wear was significantly more frequent amongst players with previous injury; such players were 2.76 times more likely to be wearers than those without previous injury. Youths were 2.31 times more likely to wear mouthguards than adults. Only 34 players (12% of respondents at follow-up) had a mouthguard constructed from the blank provided. Although youth and adult groups differed, the overall extent of mouthguard use was disappointingly low. Despite wide recognition of mouthguard value, the intervention had little effect on promoting their use. [source] Visual function in infants with brain lesions (1994)DEVELOPMENTAL MEDICINE & CHILD NEUROLOGY, Issue 11 2008Eugenio Mercuri Another in our series of commentaries on notable papers from the DMCN archives. The full paper is available at http://www.mackeith.co.uk Pike MG, Holmstrom G, de Vries LS, Pennock JM, Drew KJ, Sonksen PM, Dubowitz LM. Patterns of visual impairment associated with lesions of the preterm infant brain. Dev Med Child Neurol 1994; 36: 849,62. [source] Visual experience and age affect synaptic organization in the mushroom bodies of the desert ant Cataglyphis fortisDEVELOPMENTAL NEUROBIOLOGY, Issue 6 2010Sara Mae Stieb Abstract Desert ants of the genus Cataglyphis undergo an age-related polyethism from interior workers involved in brood care and food processing to short-lived outdoor foragers with remarkable visual navigation capabilities. The quick transition from dark to light suggests that visual centers in the ant's brain express a high degree of plasticity. To investigate structural synaptic plasticity in the mushroom bodies (MBs),sensory integration centers supposed to be involved in learning and memory,we immunolabeled and quantified pre- and postsynaptic profiles of synaptic complexes (microglomeruli, MG) in the visual (collar) and olfactory (lip) input regions of the MB calyx. The results show that a volume increase of the MB calyx during behavioral transition is associated with a decrease in MG numbers in the collar and, less pronounced, in the lip. Analysis of tubulin-positive profiles indicates that presynaptic pruning of projection neurons and dendritic expansion in intrinsic Kenyon cells are involved. Light-exposure of dark-reared ants of different age classes revealed similar effects. The results indicate that this structural synaptic plasticity in the MB calyx is primarily driven by visual experience rather than by an internal program. This is supported by the fact that dark-reared ants age-matched to foragers had MG numbers comparable to those of interior workers. Ants aged artificially for up to 1 year expressed a similar plasticity. These results suggest that the high degree of neuronal plasticity in visual input regions of the MB calyx may be an important factor related to behavior transitions associated with division of labor. © 2010 Wiley Periodicals, Inc. Develop Neurobiol 70: 408,423, 2010 [source] Phenotypic plasticity in number of glomeruli and sensory innervation of the antennal lobe in leaf-cutting ant workers (A. vollenweideri)DEVELOPMENTAL NEUROBIOLOGY, Issue 4 2010Christina Kelber Abstract In the leaf-cutting ant Atta vollenweideri, the worker caste exhibits a pronounced size-polymorphism, and division of labor is dependent on worker size (alloethism). Behavior is largely guided by olfaction, and the olfactory system is highly developed. In a recent study, two different phenotypes of the antennal lobe of Atta vollenweideri workers were found: MG- and RG-phenotype (with/without a macroglomerulus). Here we ask whether the glomerular numbers are related to worker size. We found that the antennal lobes of small workers contain ,390 glomeruli (low-number; LN-phenotype), and in large workers we found a substantially higher number of ,440 glomeruli (high-number; HN-phenotype). All LN-phenotype workers and some small HN-phenotype workers do not possess an MG (LN-RG-phenotype and HN-RG-phenotype), and the remaining majority of HN-phenotype workers do possess an MG (HN-MG-phenotype). Using mass-staining of antennal olfactory receptor neurons we found that the sensory tracts divide the antennal lobe into six clusters of glomeruli (T1,T6). In LN-phenotype workers, ,50 glomeruli are missing in the T4-cluster. Selective staining of single sensilla and their associated receptor neurons revealed that T4-glomeruli are innervated by receptor neurons from the main type of olfactory sensilla, the Sensilla trichodea curvata. The other type of olfactory sensilla (Sensilla basiconica) exclusively innervates T6-glomeruli. Quantitative analyses of differently sized workers revealed that the volume of T6 glomeruli scales with the power of 2.54 to the number of Sensilla basiconica. The results suggest that developmental plasticity leading to antennal-lobe phenotypes promotes differences in olfactory-guided behavior and may underlie task specialization within ant colonies. © 2009 Wiley Periodicals, Inc. Develop Neurobiol 70: 222,234, 2010. [source] Metabolic and haemodynamic effects of metformin in patients with type 2 diabetes mellitus and hypertensionDIABETES OBESITY & METABOLISM, Issue 5 2001M. H. Uehara SUMMARY Background Since metformin improves insulin sensitivity, it has been indicated for patients with diabetes and hypertension, which are insulin-resistant conditions. In contrast to its well-known effects on carbohydrate metabolism, its potential for reducing blood pressure (BP) and its effect on leptin levels have been investigated less frequently. Patients and Methods A double-blind, randomized, placebo-controlled trial was carried out with 26 overweight diabetic subjects with mild-to-moderate hypertension to assess the effects of metformin-induced glycaemic control on BP and metabolic parameters. After a 4-week placebo period, when BP was stabilized by calcium channel blockers, they received either metformin (MG) or placebo (PG) for 12 weeks. Results Neither group showed any change in weight throughout the study. Only metformin-treated patients reduced fasting plasma glucose (8.54 + 1.72 to 7.54 + 1.33 mmol/l, p <,0.05), although HbA1c had decreased in both groups (PG: 6.7±3.0 to 5.9±2.6%; MG: 5.3±1.5 to 4.6±0.9%; p <,0.05). The initial office mean BPs were similar and decreased at the end of the treatment period in both groups, reaching statistical significance only in MG (105.7±8.0 to 99.2±9.3 mmHg, p <,0.05). No difference was observed when comparing baseline and final values obtained by 24-h ambulatory BP monitoring. Metformin induced a reduction in both insulinaemia (71.0±62.4 to 38.0±23.0 pmol/l, p <,0.05) and the insulin resistance index (3.5±2.7 to 1.8±1.0, p <,0.05). The two groups had similar baseline leptin levels which remained unchanged after treatment (PG: 16.8±7.9 to 21.4±14.6 ,g/l; MG: 18.5±10.3 to 18.4±8.9 ,g/l). Dopamine levels increased significantly only in metformin-treated subjects. Conclusions Reductions in both the insulin levels and the resistance index reinforced metformin capacity to improve peripheral sensitivity. Moreover, such benefits were not accompanied by any hypotensive effects. Since leptin levels were affected neither by metformin per se nor by the induced insulinaemia reduction, our data support the role of body weight as the major determinant of circulating leptin levels. [source] Distal esophagitis in patients with mustard-gas induced chronic coughDISEASES OF THE ESOPHAGUS, Issue 4 2006M. Ghanei SUMMARY., Although confounded by some factors such as medications or surgical complications, the relationship between esophageal pathology and pulmonary disorders has been the subject of many studies. The present study sought to investigate the said relationship in patients inflicted by respiratory disorders induced by mustard gas (MG). A case group of patients complaining of respiratory complications and chronic coughs following MG exposure, and a control group of patients with chronic coughs but without a history of MG exposure were studied. All the case and control subjects had symptoms of gastro-esophageal reflux disease. Chest high resolution tomography (HRCT) was performed to evaluate the existence of pulmonary disorders. Endoscopy and histological studies were carried out to determine the severity of esophagitis in both groups presenting with gastroesophageal reflux. Ninety male patients, who had met our criteria, along with 40 male control cases underwent the diagnostic procedures. The frequency of endoscopic esophagitis findings in the chemically exposed group was significantly higher than that in the control group (70.0%vs. 42.5%). A pathological evaluation revealed that the frequency of esophagitis in the cases was more than that in the controls (32.3%vs. 14.2%). Chest HRCT evaluation demonstrated that half the case group had more than 25% air trapping in expiratory films, mostly compatible with bronchiolitis obliterans (BO). In addition, they were suffering from asthma, chronic bronchitis and bronchiectasis. Bronchiolitis obliterans, along with other lung disorders, can be considered as contributors in the pathogenesis of esophagitis in MG exposed patients. [source] Selection and identification of bacterial strains with methyl- tert -butyl ether, ethyl- tert -butyl ether, and tert -amyl methyl ether degrading capacitiesENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 11 2008Jessica Purswani Abstract Nine bacterial strains isolated from two hydrocarbon-contaminated soils were selected because of their capacity for growth in culture media amended with 200 mg/L of one of the following gasoline oxygenates: Methyl- tert -butyl ether (MTBE), ethyl- tert -butyl ether (ETBE), and tert -amyl methyl ether (TAME). These strains were identified by amplification of their 16S rRNA gene, using fD1 and rD1 primers, and were tested for their capacity to grow and biotransform these oxygenates in both mineral and cometabolic media. The isolates were classified as Bacillus simplex, Bacillus drentensis, Arthrobacter sp., Acinetobacter calcoaceticus, Acinetobacter sp., Gordonia amicalis (two strains), Nocardioides sp., and Rhodococcus ruber. Arthrobacter sp. (strain MG) and A. calcoaceticus (strain M10) consumed 100 (cometabolic medium) and 82 mg/L (mineral medium) of oxygenate TAME in 21 d, respectively, under aerobic conditions. Rhodococcus ruber (strain E10) was observed to use MTBE and ETBE as the sole carbon and energy source, whereas G. amicalis (strain T3) used TAME as the sole carbon and energy source for growth. All the bacterial strains transformed oxygenates better in the presence of an alternative carbon source (ethanol) with the exception of A. calcoaceticus (strain M10). The capacity of the selected strains to remove MTBE, ETBE, and TAME looks promising for application in bioremediation technologies. [source] Isolation and characterization of human anti-acetylcholine receptor monoclonal antibodies from transgenic mice expressing human immunoglobulin lociEUROPEAN JOURNAL OF IMMUNOLOGY, Issue 6 2005Evdokia Protopapadakis Abstract The isolation of human antibodies against muscle acetylcholine receptor (AChR), the autoantigen involved in myasthenia gravis (MG), is important for the development of therapeutically useful reagents. Monovalent antibody fragments from monoclonal antibodies against the main immunogenic region (MIR) of AChR protect the receptor from the destructive activity of MG autoantibodies. Human anti-AChR ,-subunit antibody fragments with therapeutic potential have been isolated using phage display antibody libraries. An alternative approach for obtaining human mAb has been provided by the development of humanized mice. In this report, we show that immunization of transgenic mouse strains with the extracellular domain of the human AChR ,-subunit results in antibody responses and isolation of hybridomas producing human mAb. Four specific IgM mAb were isolated and analyzed. mAb170 recognized the native receptor the best and was capable of inducing AChR antigenic modulation, suggesting its specificity for a pathogenic epitope. Moreover, the recombinant antigen-binding (Fab) fragment of this mAb competed with an anti-MIR mAb, revealing that its antigenic determinant lies in or near the MIR. Finally, Fab170 was able to compete with MG autoantibodies and protect the AChR against antigenic modulation induced by MG sera. This approach will be useful for isolating additional mAb with therapeutic potential against the other AChR subunits. [source] Seronegative myasthenia gravis: disease severity and prognosisEUROPEAN JOURNAL OF NEUROLOGY, Issue 6 2005F. Romi Around 10,20% of myasthenia gravis (MG) patients do not have acetylcholine receptor (AChR) antibodies (seronegative), of whom some have antibodies to a membrane-linked muscle specific kinase (MuSK). To examine MG severity and long-term prognosis in seronegative MG compared with seropositive MG, and to look specifically at anti-AChR antibody negative and anti-MuSK antibody negative patients. Seventeen consecutive seronegative non-thymomatous MG patients and 34 age and sex matched contemporary seropositive non-thymomatous MG controls were included in a retrospective follow-up study for a total period of 40 years. Clinical criteria were assessed each year, and muscle antibodies were assayed. There was no difference in MG severity between seronegative and seropositive MG. However, when thymectomized patients were excluded from the study at the year of thymectomy, seropositive MG patients had more severe course than seronegative (P < 0.001). One seropositive patient died from MG related respiratory insufficiency. The need for thymectomy in seronegative MG was lower than in seropositive MG. None of the seronegative patients had MuSK antibodies. This study shows that the presence of AChR antibodies in MG patients correlates with a more severe MG. With proper treatment, especially early thymectomy for seropositive MG, the outcome and long-term prognosis is good in patients with and without AChR antibodies. [source] Changes in contractile properties of motor units of the rat medial gastrocnemius muscle after spinal cord transectionEXPERIMENTAL PHYSIOLOGY, Issue 5 2006Jan Celichowski The effects of complete transection of the spinal cord at the level of Th9/10 on contractile properties of the motor units (MUs) in the rat medial gastrocnemius (MG) muscle were investigated. Our results indicate that 1 month after injury the contraction time (time-to-peak) and half-relaxation time were prolonged and the maximal tetanic force in most of the MUs in the MG muscle of spinal rats was reduced. The resistance to fatigue also decreased in most of the MUs in the MG of spinal animals. Moreover, the post-tetanic potentiation of twitches in MUs diminished after spinal cord transection. Criteria for the division of MUs into three types, namely slow (S), fast fatigue resistant (FR) and fast fatigable (FF), applied in intact animals, could not be directly used in spinal animals owing to changes in contractile properties of MUs. The ,sag' phenomenon observed in unfused tetani of fast units in intact animals essentially disappeared in spinal rats and it was only detected in few units, at low frequencies of stimulation only. Therefore, the MUs in spinal rats were classified as fast or slow on the basis of an adjusted borderline of 20 ms, instead of 18 ms as in intact animals, owing to a slightly longer contraction time of those fast motor units with the ,sag'. We conclude that all basic contractile properties of rat motor units in the medial gastrocnemius muscle are significantly changed 1 month after complete spinal cord transection, with the majority of motor units being more fatigable and slower than those of intact rats. [source] Bacteria and PAMPs activate nuclear factor ,B and Gro production in a subset of olfactory ensheathing cells and astrocytes but not in Schwann cellsGLIA, Issue 9 2007Adele J. Vincent Abstract The primary olfactory nerves provide uninterrupted conduits for neurotropic pathogens to access the brain from the nasal cavity, yet infection via this route is uncommon. It is conceivable that olfactory ensheathing cells (OECs), which envelope the olfactory nerves along their entire length, provide a degree of immunological protection against such infections. We hypothesized that cultured OECs would be able to mount a biologically significant response to bacteria and pathogen-associated molecular patterns (PAMPs). The response of OECs to Escherichia coli (E. coli) and various PAMPs was compared to that of Schwann cells (SCs), astrocytes (ACs), and microglia (MG). A subset of OECs displayed nuclear localization of nuclear factor ,B), an inflammatory transcription factor, after treatment with E. coli (20% ± 5%), lipopolysacchride (33% ± 9%), and Poly I:C (25% ± 5%), but not with peptidoglycan or CpG oligonucleotides. ACs displayed a similar level of activation to these treatments, and in addition responded to peptidoglycan. The activation of OECs and ACs was enhanced by coculture with MG (56% ± 16% and 85% ± 13%, respectively). In contrast, SCs did not respond to any treatment or to costimulation by MG. Immunostaining for the chemokine Gro demonstrated a functional response that was consistent with NF,B activation. OECs expressed mRNA for Toll-like receptors (TLRs) 2 and 4, but only TLR4 protein was detected by Western blotting and immunohistochemistry. The results demonstrate that OECs possess the cellular machinery that permits them to respond to certain bacterial ligands, and may have an innate immune function in protecting the CNS against infection. © 2007 Wiley-Liss, Inc. [source] Tumor necrosis factor-, augments lipopolysaccharide-induced suppressor of cytokine signalling 3 (SOCS-3) protein expression by preventing the degradationIMMUNOLOGY, Issue 1 2010Jargalsaikhan Dagvadorj Summary The regulatory role of tumour necrosis factor-, (TNF-,) on the expression of suppressor of cytokine signalling 3 (SOCS-3) in response to lipopolysaccharide (LPS) was examined using peritoneal macrophages from TNF-,-deficient mice. The LPS-induced SOCS-3 expression was markedly augmented in macrophages from wild-type mice whereas such augmentation was not seen in the cells from TNF-,-deficient mice. However, there was no significant difference in the level of SOCS-3 messenger RNA expression between macrophages from wild-type mice and those from TNF-,-deficient mice. The addition of exogenous TNF-, augmented the LPS-induced SOCS-3 expression in macrophages from TNF-,-deficient mice. The pulse chase analysis suggested augmented degradation of LPS-induced SOCS-3 protein in macrophages from TNF-,-deficient mice. Moreover, MG 132, a 26S proteasome inhibitor, sustained the LPS-induced SOCS-3 expression in those cells. The tyrosine phosphorylation of SOCS-3 was definitely induced in LPS-stimulated macrophages from TNF-,-deficient mice but not wild-type mice. A tyrosine phosphatase inhibitor enhanced the tyrosine phosphorylation of SOCS-3 in wild-type mice and accelerated the degradation. Therefore, it was suggested that TNF-, prevented the degradation of SOCS-3 protein via inhibition of the tyrosine phosphorylation in LPS-stimulated macrophages. [source] Apatite-forming ability (bioactivity) of ProRoot MTAINTERNATIONAL ENDODONTIC JOURNAL, Issue 10 2010M. G. Gandolfi Gandolfi MG, Taddei P, Tinti A, Prati C. Apatite-forming ability (bioactivity) of ProRoot MTA. International Endodontic Journal, 43, 917,929, 2010. Abstract Aim, Apatite-forming ability, considered as an index of bioactivity (bond-to-bone ability), was tested on ProRoot MTA cement after immersion in phosphate-containing solution (DPBS). Methodology, Disk samples were prepared and immersed in DPBS for 10 min, 5 h, 1 and 7 days. The cement surface was studied by attenuated total reflectance Fourier transform infrared (ATR-FTIR) spectroscopy, by micro-Raman spectroscopy and by environmental scanning electron microscope with energy dispersive X-ray (ESEM-EDX) analyses. The pH of the storage solution was also investigated. Results, Spectroscopic analyses revealed calcium phosphate bands after 5-h immersion in DPBS. After 1 day, an even coating composed of apatite spherulites (0.1,0.8 micron diameter) was observed by ESEM/EDX. After 7 days, its thickness had increased. Apatite nucleation had already occurred after 5-h immersion. At this time, the presence of portlandite (i.e. Ca(OH)2, calcium hydroxide) on the cement surface was also observed; at longer times, this component was released into the medium, which underwent a remarkable pH increase. Conclusions, The study confirms the ability of ProRoot MTA to form a superficial layer of apatite within hours. The excellent bioactivity of ProRoot MTA might provide a significant clinical advantage over the traditional cements used for root-end or root-perforation repair. [source] A dual mesh multigrid preconditioner for the efficient solution of hydraulically driven fracture problemsINTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN ENGINEERING, Issue 13 2005A. P. Peirce Abstract We present a novel multigrid (MG) procedure for the efficient solution of the large non-symmetric system of algebraic equations used to model the evolution of a hydraulically driven fracture in a multi-layered elastic medium. The governing equations involve a highly non-linear coupled system of integro-partial differential equations along with the fracture front free boundary problem. The conditioning of the algebraic equations typically degrades as O(N3). A number of characteristics of this problem present significant new challenges for designing an effective MG strategy. Large changes in the coefficients of the PDE are dealt with by taking the appropriate harmonic averages of the discrete coefficients. Coarse level Green's functions for multiple elastic layers are constructed using a single dual mesh and superposition. Coarse grids that are sub-sets of the finest grid are used to treat mixed variable problems associated with ,pinch points.' Localized approximations to the Jacobian at each MG level are used to devise efficient Gauss,Seidel smoothers and preferential line iterations are used to eliminate grid anisotropy caused by large aspect ratio elements. The performance of the MG preconditioner is demonstrated in a number of numerical experiments. Copyright © 2005 John Wiley & Sons, Ltd. [source] ,v -Integrin antagonist EMD 121974 induces apoptosis in brain tumor cells growing on vitronectin and tenascinINTERNATIONAL JOURNAL OF CANCER, Issue 5 2002Takashi Taga Abstract Orthotopic brain tumor growth is inhibited in athymic mice by the daily systemic administration of the ,v -integrin antagonist EMD 121974. This compound, a cyclic RGD-penta-peptide, is a potent inhibitor of angiogenesis, which induces apoptosis of growing endothelial cells through inhibition of their ,v -integrin interaction with the matrix proteins vitronectin and tenascin. Here we show that EMD 121974 also induces apoptosis in the ,v -integrin-expressing tumor cell lines U87 MG and DAOY by detaching them from vitronectin and tenascin, matrix proteins known to be essential for brain tumor growth and invasion. These matrix proteins are shown to be produced by the brain tumor cells in vitro and in vivo. Furthermore, only tumor cells expressing ,v -integrins responded to the treatment with EMD 121974, after xenotransplantation into the forebrain of nude mice, supporting the importance of tumor cell-matrix interactions in tumor cell survival in the brain. Thus, the ,v -antagonist EMD 121974 suppresses brain tumor growth through induction of apoptosis in both brain capillary and brain tumor cells by preventing their interaction with the matrix proteins vitronectin and tenascin. The dual action of this peptide explains its potent growth suppression of orthotopically transplanted brain tumors. © 2002 Wiley-Liss, Inc. [source] Are single-gift committed donors different from their multiple-gift counterparts?INTERNATIONAL JOURNAL OF NONPROFIT & VOLUNTARY SECTOR MARKETING, Issue 3 2010Anyuan Shen Committed donors who keep giving every year are a key asset for nonprofit organizations because they provide a steady funding source and return a higher lifetime value. We distinguish between committed donors who give only one gift per year (single-gift (SG) donors) and those who give multiple gifts in at least some year (multiple-gift (MG) donors). In this paper, we study whether SG donors and MG donors follow different longitudinal patterns of gift-giving in four consecutive years. We theorize that a donor's yearly gift amount is an indication of his or her willingness to give (WTG) to the organization and may be explained in terms of his or her intrinsic willingness to give (IWTG) and extrinsic willingness to give (EWTG) for that year. We test our theory with data from a leading US nonprofit organization and find that SG donors and MG donors would follow different longitudinal patterns: While SG donors and MG donors would start off at a similar level of WTG in year 1 and would both increase WTG in subsequent years, MG donors would record a higher rate of increase than SG donors. IWTG and EWTG would have different relative importance as determinants of the observed yearly giving level: MG donors depend on both IWTG and EWTG whereas SG donors largely depend on IWTG rather than EWTG to determine how much to give in a year. Our findings suggest that different strategies are needed to manage SG donors and MG donors to sustain and grow annual contributions. Copyright © 2009 John Wiley & Sons, Ltd. [source] Adduct-forming tendencies of cationic triarylmethane dyes with proteins: Metabolic and toxicological implicationsJOURNAL OF BIOCHEMICAL AND MOLECULAR TOXICOLOGY, Issue 5 2004Özden Tacal Abstract The formation of colorless adducts by four cationic triarylmethane dyes (TAM+s), methyl green (MeG+), malachite green (MG+), pararosaniline (PR+), and crystal violet (CV+) was studied spectrophotometrically at 25°C, in 50 mM 3-(N-morpholino)propanesulfonic acid (MOPS) buffer (pH 8), by monitoring the loss in TAM+ color in the absence and presence of human serum proteins as potential addends. Unfractionated serum caused a rapid bleaching of MeG+ and MG+, while PR+ and CV+ were unaffected. Sephacryl S200 HR chromatographic screening of the serum revealed two composite peaks of MeG+ -bleaching activity. The major peak (Mr range, 40,000,130,000) overlapped with and extended on either side of the albumin peak. The minor peak corresponding to ca. 10% of the total MeG+ -bleaching capacity had Mr > 230,000. MG+ -bleaching activity dominated the entire chromatographic profile and implicated a multitude of minority proteins with a high capacity to form colorless MG adducts. It is concluded that highly electrophilic TAM+s such as MeG+ and MG+ must be quantitatively trapped in the form of dye,protein adducts in biological fluids and that the primary in vivo effects (e.g. toxicity) of such dyes most likely arise from ligand-type effects on multiple protein targets. Mechanisms that call for unmodified TAM+ structure (radical-mediated redox changes, DNA intercalation) may be more relevant to the in vivo impact of dyes such as PR+ and CV+ that have a lower tendency to form adducts. © 2004 Wiley Periodicals, Inc. J Biochem Mol Toxicol 18:253,256, 2004 Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/jbt.20034 [source] Successful Mitral Valve Surgery in a Patient with Myasthenia GravisJOURNAL OF CARDIAC SURGERY, Issue 2 2009Cüneyt Narin M.D. Most of the patients die because of a respiratory failure toward the end of the disease. A 49-year-old male patient with MG in whom a thymectomy operation had been performed five years ago had dyspnea, palpitation, and chest pain during his admission. After his examination, a severe mitral regurgitation was detected, and he underwent a successful mitral valve replacement. A general anesthesia management was performed using sufentanyl and propophol without any muscle relaxant agent. He was extubated seven hours after the surgery. He had difficulty in swallowing at postoperative day three, and his medication doses were increased. He was discharged from the hospital at postoperative day seven without any complication. MG is a rare disease and may cause morbid complications during the cardiac surgery, but can be successfully managed. [source] Patient-Prosthesis Mismatch After Small-Size Stentless Aortic Valve ReplacementJOURNAL OF CARDIAC SURGERY, Issue 2 2004Sandro Gelsomino M.D. Methods: Sixty-two patients (mean age 70.9 ± 5.2 years, 77.8% females), receiving a labeled 21,23 mm CLOB between 1993 and 2000, were retrospectively studied. Effective orifice area (EOA) was calculated by the continuity equation and then indexed to the patient's body surface area (BSA) to obtain the indexed EOA (EOAI). Based on previous observations a mismatch was defined as EOAI , 0.85 cm2/m2. Results: Twelve patients (20%) at discharge, two (3.3%) at 6 months and none at late controls had an EOAI , 0.85 cm2/m2. At ANOVA determinants of mismatch were female sex (p < 0.001), age (p = 0.01), and patient's annulus index (PAI, p < 0.001). Patients with mismatch had higher mean gradients (MG, p = 0.01, and p < 0.001 at discharge and 6 months, respectively) and EOAI correlated with MG at discharge (r2= 0.72, p < 0.001) and 6-month (r2= 0.40, p = 0.001) studies. At 1 year no difference in MG was detected between patients with or without mismatch (p = ns) and EOAI did not correlate with MG (r2= 0.01, p = ns). Midwall fractional shortening did not differ in patients with or without mismatch (p = ns). Patients with an EOAI , 0.8 cm/m2 showed an earlier concentric remodeling up to 1 year; no difference was demonstrated at later studies between groups. Survival and clinical status results were not affected by an EOAI , 0.85 cm2/m2. Conclusions: After AVR with CLOB mismatch occurred early postoperatively in a small number of patients without clinical repercussions. EOAI, significantly increasing over time, was adequate to BSA in all patients at late controls. (J Card Surg 2004;19:91-97) [source] Spindle pole fragmentation due to proteasome inhibitionJOURNAL OF CELLULAR PHYSIOLOGY, Issue 3 2005Anka G. Ehrhardt During interphase, the centrosome concentrates cell stress response molecules, including chaperones and proteasomes, into a proteolytic center. However, whether the centrosome functions as proteolytic center during mitosis is not known. In this study, cultured mammalian cells were treated with the proteasome inhibitor MG 132 and spindle morphology in mitotic cells was characterized in order to address this issue. Proteasome inhibition during mitosis leads to the formation of additional asters that cause the assembly of multipolar spindles. The cause of this phenomenon was investigated by inhibiting microtubule-based transport and protein synthesis. These experimental conditions prevented the formation of supernumerary asters during mitosis. In addition, the expression of dsRed without proteasome inhibition led to the fragmentation of spindle poles. These experiments showed that the formation of extra asters depends on intact microtubule-based transport and protein synthesis. These results suggest that formation of supernumerary asters is due to excessive accumulation of proteins at the spindle poles and consequently fragmentation of the centrosome. Together, this leads to the conclusion that the centrosome functions as proteolytic center during mitosis and proteolytic activity at the spindle poles is necessary for maintaining spindle pole integrity. © 2005 Wiley-Liss, Inc. [source] Starch and albumin mixture as replacement fluid in therapeutic plasma exchange is safe and effectiveJOURNAL OF CLINICAL APHERESIS, Issue 5 2008Gladys P. Agreda-Vásquez Abstract Therapeutic plasma exchange (TPE) is an effective treatment in Myasthenia gravis (MG) and Guillain-Barré syndrome (GBS) and 5% human albumin is the replacement fluid of choice; however, it is expensive. More recently, it has been suggested that starch is a safe and cheaper choice to human albumin. Objective: To evaluate our 5-year experience using 3% hydroxyethyl starch (HES) and 5% human albumin mixture, as replacement fluid in TPE for these diseases. Materials and methods: Retrospective study carried out from January 2001 through September 2006. We included those patients with MG and GBS undergoing TPE. We analyzed clinical outcome (CO) and adverse events (AE) and our results were compared with a previous study which included similar patients undergoing TPE using just 5% human albumin. Results: Thirty-one procedures were carried out in 26 patients, a total of 147 TPE sessions. In the group of MG we had 57% complete responses (CR) and 86% overall response (OR) while in the group of GBS we had 40% CR and 60% OR. When we analyzed our CO with the previous study no statistical differences were found. Mean processed plasma volume (PPV) was 4.2 in MG and 5.5 in GBS. Twenty patients had AE, being hypotension and catheter dysfunction the most frequent ones, while tachycardia, hypertension and paresthesias were statistically more frequent in the HES/albumin group. Conclusions: TPE with a mixture of 3% HES and 5% human albumin is as effective and safe as 5% human albumin alone for patients with these diseases. J. Clin. Apheresis, 2008. © 2008 Wiley-Liss, Inc. [source] Prethymectomy plasmapheresis in myasthenia gravisJOURNAL OF CLINICAL APHERESIS, Issue 4 2005Jiann-Horng Yeh Abstract Plasma exchange before thymectomy may decrease the time on mechanical ventilation (MV) and shorten the stay in the intensive care unit (ICU) for patients with myasthenia gravis (MG). This study evaluated the effects of prethymectomy plasmapheresis. A total of 29 myasthenic patients, 18 women and 11 men aged 20,73 years, were treated with double filtration plasmapheresis (DFP) for two to five consecutive sessions over a period between 2 and 21 days (mean 8.1 days) before transsternal thymectomy. Acetylcholine receptor antibody (AchRAb) titers, vital capacity (VC), maximal inspiratory pressure (Pimax), and MG score were measured before and after the course of DFP. Three outcome measures including duration of postoperative hospital stay, duration of ICU stay, and duration of MV were analyzed for correlation with clinical variables. The duration of MV ranged from 6 to 93 h, with a median of 21 h. The median ICU stay was one day and the median postoperative hospital stay was 10 days. A higher removal rate of AchRAb was associated with a shorter duration of ICU and postoperative hospital stay (P = 0.001 and 0.019, respectively). Postoperative hospital stay was strongly correlated with post-DFP Pimax (P = 0.010), and marginally correlated with pre-DFP VC (P = 0.047) and to a lesser extent with pre-DFP Pimax (P = 0.063). Univariate analysis using the log rank test revealed that removal rate of AchRAb <30% (P = 0.043) and pre-DFP Pimax <,60 cmH2O (P = 0.024) were significantly associated with prolonged ICU stay. Risk factors for prolonged postoperative stay included post-DFP Pimax <,60 cmH2O (P = 0.017), pre-DFP Pimax <,60 cmH2O (P = 0.031), and post-DFP VC < 1.0 L (P = 0.046). Our results confirmed the efficacy and safety of DFP in prethymectomy preparation for myasthenic patients. J. Clin. Apheresis, 2005 © 2005 Wiley-Liss, Inc. [source] Patients with thrombotic thrombocytopenic purpura commonly develop metabolic alkalosis during therapeutic plasma exchangeJOURNAL OF CLINICAL APHERESIS, Issue 3 2001Marisa B. Marques Abstract Thrombotic thrombocytopenic purpura (TTP) and myasthenia gravis (MG) are category I indications for therapeutic plasma exchange (TPE). This study was based on the hypothesis that the development of metabolic alkalosis during TPE is more common in TTP than in MG, based on our previous observations. In order to test it, we compared the levels of bicarbonate and potassium in both groups of patients undergoing plasmapheresis. Fifteen patients with TTP (190 procedures) and ten MG patients seen concurrently were studied. While baseline bicarbonate levels were similar among all patients, the post-procedure bicarbonate levels in TTP patients were mostly elevated with a mean ± SD of 29.4 ± 3.5 mEq/L, as opposed to decreased or unchanged in MG patients 26.3 ± 3.1 mEq/L (mean ± SD) (P = 1.4 × 10,8). Furthermore, alkalosis in the TTP group persisted throughout subsequent daily treatments. There was also a significant decrease between pre- and post-TPE potassium levels in TTP patients (P = 3 × 10,21) by paired Student's t test. Additionally, samples with levels <3.3 mEq/L were alkalotic 75% of the time. In the MG group, however, potassium was normal in 85% and 83% of the pre- and post-TPE samples, respectively. Consequently, the hypokalemia was significantly more marked in the TTP group (P = 0.0008). These data confirm that plasmapheresis commonly induces metabolic alkalosis in TTP patients, probably due to high citrate in fresh frozen plasma, the frequency of treatments, and perhaps decreased renal clearance due to disease involvement of the kidneys. J. Clin. Apheresis. 16:120,124, 2001. © 2001 Wiley-Liss, Inc. [source] Accumulation of methylglyoxal in the gingival crevicular fluid of chronic periodontitis patientsJOURNAL OF CLINICAL PERIODONTOLOGY, Issue 4 2003S. Kashket Abstract Background, aims: Methylglyoxal (MG), a toxic product of cellular metabolism, is elevated in tissues and fluids in a number of human diseases. A cross-sectional study was undertaken to determine whether MG accumulates in the gingival crevicular fluid (GCF) of chronic periodontitis patients. Methods: GCF samples were collected for 30 s each from three teeth with pocket depths greater than 3 mm (DD sites), from 14 chronic periodontitis patients. Control samples were taken from three healthy sites (DH sites) in the same patients, as well as from seven subjects who were periodontally healthy (HH sites). Fluid volumes were determined and the strips were placed in 0.5 N perchloric acid. Subsequently, samples were derivatized with o -phenylenediamine and the resulting methylquinoxaline was assayed by high-performance liquid chromatography on Lichrospher® -100 RP-18, with UV detection. Results: Mean pocket depths were 5.7±0.7, 2.7±0.6 and 2.7±0.5 mm (mean±SD) for the DD, DH and HH sites, respectively. Mean MG levels were found to be 208.7±241.7 and 142.9±235.7 pmol/site in the GCF from DD and DH sites, respectively (p=0.0023), but only 11.5±4.4 pmol/site for the HH sites. Bacteroides forsythus has been found to accumulate high levels of MG in culture (unpublished data) and, consistent with this, the sampled diseased sites contained higher levels of B. forsythus than the corresponding healthy sites (2.7±4.2×105 versus 0.7±1.1×105, respectively; p=0.022). Total "red complex" microorganisms were significantly elevated in the DD sites. Conclusions: In view of the known protein- and DNA-modifying effects of MG, the finding of elevated levels of MG in the GCF from chronic periodontitis patients supports the hypothesis that MG may contribute to destructive tissue damage in this disease. Zusammenfassung Hintergrund: Methylglyoxal (MG), ein toxisches Produkt des Zellstoffwechsels, ist bei einer Reihe menschlicher Erkrankungen in Geweben und Körperflüssigkeiten erhöht. Zielsetzung: Querschnittsstudie zur Klärung der Frage, ob sich MG in der Sulkusflüssigkeit (SF) bei Patienten mit chronischer Parodontitis ansammelt. Methoden: Bei 14 Patienten mit chronischer Parodontitis wurde SF für 30 s an 3 Zähnen mit Sondierungstiefen >3 mm (DD-Stellen) gewonnen. Kontrollproben wurden von jeweils 3 gesunden Stellen (DH-Stellen) bei den gleichen Patienten und bei 7 parodontal gesunden Personen gewonnen (HH-Stellen). Die Flüssigkeitsvolumina wurden bestimmt und die Probenstreifen in 0,5 N Perchlorsäure gegeben. Anschließend wurden die Proben mit o-Phenyldiamin versetzt und das resultierende Methylquinoxalin wurde mittels High-Performance-Liquid-Chromatographie in einem Lichrospher®-100 RP-18 bei UV-Detektion nachgewiesen. Ergebnisse: Die mittleren Sondierungstiefen lagen bei 5,7±0,7, an den DD-Stellen, bei 2,7±0,6 (DH) und 2,7±0,5 mm (Mittelwert + Standardabweichung) (HH). Die mittleren MG-Spiegel lagen bei 208,7±241,7 an den DD-Stellen und bei 142,9±235,7 pmol/Stelle an den DH-Stellen (p=0,0023), aber nur bei 11,5±4,4 pmol/Stelle an den HH-Stellen. Es war gezeigt worden, dass Bacteroides forsythus in Kultur hohe Konzentrationen von MG ansammelt (unveröffentlichte Daten) und übereinstimmend damit wurden an den untersuchten DD-Stellen höhere Zahlen von B. forsythus gefunden als an den entsprechenden gesunden Stellen (2,7±4,2×105 versus 0,7±1,1×105; p=0,022). Die Zahl aller Keime des "Roten Komplexes" waren an DD-Stellen signifikant erhöht. Schlussfolgerungen: In Anbetracht der bekannten Proteine und DNS verändernden Effekte von MG unterstützt dieser Nachweis erhöhter MG-Spiegel in der SF bei Patienten mit chronischer Parodontitis die Hypothese, dass MG zur Gewebezerstörung bei Parodontitis beiträgt. Résumé Références et buts: Le méthylglyoxal (MG), un produit toxique du métabolisme cellulaire est retrouvé en quantitéélevée dans les tissus et les fluides lors de nombreuses maladies humaines. Une étude croisée fut réalisée pour déterminer si MG s'accumulait dans le fluide gingival (GCF) des patients atteints de parodontite chronique. Méthodes: Des échantillons de GCF furent prélevés pendant 30 secondes chacun de 3 dents avec des profondeurs de poches de plus de 3 mm (sites DD), chez 14 patients atteints de parodontites chroniques. Des échantillons contrôles furent prélevés sur des sites sains (sites DH) chez les mêmes patients, et aussi chez 7 sujets au parodonte sain (sites HH). Les volumes de fluide furent déterminés et les bandelettes ont été mises dans 0.5 N d'acide perchlorique. Puis, les échantillons furent transformés à l'aide de o-phenylenediamine et la méthylquinoxaline ainsi créée fut analysé par chromatographie liquide à haute performance sur une Lichrospher®-100 RP-18, avec détection aux UV. Résultats: Les profondeurs de poche moyenne étaient de 5.7 ± 0.7, 2.7 ± 0.6 et 2.7±0.5 mm (moyenne ± SD) pour les sites DD, DH et HH, respectivement. Les niveaux moyen de MG étaient de 208.7±241.7 et 142.9±235.7 pmol/site dans le fluide des sites in DD et DH, respectivement (p=0.0023), mais seulement de 11.5±4.4 pmol/site pour les sites HH. On a trouvé que Bacteroides forsythus accumulait de hauts niveaux de MG en culture (données non publiées) et les sites malades échantillonnés contenait effectivement de plus hauts niveaux de B. forsythus que les sites sains correspondants (2.7±4.2×105 contre 0.7±1.1×105, respectivement; p=0.022). Les microorganismes du complexe rouge étaient significativement en nombre élevé dans les sites DD. Conclusions: Au vu des effets connus de MG pour modifier les protéines et l'AND, la découverte de niveaux élevés de MG dans le fluide gingival de patients atteints de maladie parodontale chronique supporte l'hypothèse selon laquelle MG pourrait contribuer aux dommages tissulaires destructifs rencontrés au cours de cette maladie. [source] |