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Kinds of Flat Terms modified by Flat Selected AbstractsComparative Study of Flat and Round Collectors Using a Validated 1D Fluid Probe ModelCONTRIBUTIONS TO PLASMA PHYSICS, Issue 5-6 2006P. Peleman Abstract In the literature two different types of Gundestrup-like probe designs are proposed: design with flat and with round collectors. In this paper we study the influence of different collector shapes of Gundestrup-like probes on the accuracy of the measurement of the parallel and perpendicular flows. A one dimensional fluid probe model is used for deducing both Mach numbers of the unperturbed flow from the probe data. An analytical expression relates the plasma flow to the measured ion saturation currents collected at the upstream and downstream collecting surfaces of the probe. For flat collectors, the analytical model is validated by comparing it to a two dimensional quasi-neutral Particle In Cell (PIC) simulation code. An extension of the theoretical model then allows us to study round collectors. We performed an accuracy study which showed that systematic errors are introduced when round collectors are employed for determination of the perpendicular flow which is systematically overestimated. The error can reach more than 70% when the perpendicular flow increases and when the angle of the collecting surface with respect to the magnetic field (, , 0)is small. The correct analytical expression is applied to experimental data from Gundestrup probe measurements with round collectors on the CASTOR tokamak. The analysis shows that for these measurements the error introduced by using the expression for flat collectors remains negligible, supporting our former use of the model for flat collectors. A new advanced Gundestrup-like probe design and the motivation for the choice of flat collectors are presented. (© 2006 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Comparisons of overground endoscopy and treadmill endoscopy in UK Thoroughbred racehorsesEQUINE VETERINARY JOURNAL, Issue 3 2010K. J. ALLEN Summary Reasons for performing study: To date there is no information on the comparison of the more recently documented technique of performing endoscopy during ridden exercise in the field, with the more traditional method of endoscopy during high-speed treadmill exercise. Objectives: To compare the results of upper respiratory tract endoscopy in UK Thoroughbred racehorses performed during ridden exercise in the field with those obtained during exercise on the treadmill. Methods: A direct comparison was undertaken in 4 horses whereby both procedures were performed in the same horse within 10 days of each other. An indirect comparison was also undertaken whereby the results of overground endoscopy performed in 50 racehorses was compared to the results obtained during treadmill endoscopy in a further 50 racehorses. Horses were matched for age, gender, use (National Hunt vs. Flat) and presenting complaint (abnormal respiratory noise vs. poor performance). Results: Dorsal displacement of the soft palate was diagnosed less frequently during overground endoscopy than during treadmill endoscopy. There was no significant difference in the diagnosis of dynamic laryngeal collapse between the 2 techniques. The treadmill exercise test was performed over longer distances at higher inclines, albeit at lower speeds than the overground test. In contrast to the treadmill test, the overground test was frequently performed in intervals. Conclusions: The results of both the direct and indirect comparisons suggest that dorsal displacement of the soft palate is diagnosed less often during overground endoscopy than during treadmill endoscopy. Strenuous exercise tests may be more easily performed on a treadmill than by performing multiple exercise intervals in the field. Potential relevance: Care should be taken in interpreting negative findings during both procedures, but particularly during overground endoscopy if racing conditions have not been appropriately replicated. [source] Revisiting a Classification Scheme for U.S.-Mexico Alluvial Basin-Fill AquifersGROUND WATER, Issue 5 2005Barry J. Hibbs Intermontane basins in the Trans-Pecos region of westernmost Texas and northern Chihuahua, Mexico, are target areas for disposal of interstate municipal sludge and have been identified as possible disposal sites for low-level radioactive waste. Understanding ground water movement within and between these basins is needed to assess potential contaminant fate and movement. Four associated basin aquifers are evaluated and classified; the Red Light Draw Aquifer, the Northwest Eagle Flat Aquifer, the Southeast Eagle Flat Aquifer, and the El Cuervo Aquifer. Encompassed on all but one side by mountains and local divides, the Red Light Draw Aquifer has the Rio Grande as an outlet for both surface drainage and ground water discharge. The river juxtaposed against its southern edge, the basin is classified as a topographically open, through-flowing basin. The Northwest Eagle Flat Aquifer is classified as a topographically closed and drained basin because surface drainage is to the interior of the basin and ground water discharge occurs by interbasin ground water flow. Mountains and ground water divides encompass this basin aquifer on all sides; yet, depth to ground water in the interior of the basin is commonly >500 feet. Negligible ground water discharge within the basin indicates that ground water discharges from the basin by vertical flow and underflow to a surrounding basin or basins. The most likely mode of discharge is by vertical, cross-formational flow to underlying Permian rocks that are more porous and permeable and subsequent flow along regional flowpaths beneath local ground water divides. The Southeast Eagle Flat Aquifer is classified as a topographically open and drained basin because surface drainage and ground water discharge are to the adjacent Wildhorse Flat area. Opposite the Eagle Flat and Red Light Draw aquifers is the El Cuervo Aquifer of northern Chihuahua, Mexico. The El Cuervo Aquifer has interior drainage to Laguna El Cuervo, which is a phreatic playa that also serves as a focal point of ground water discharge. Our evidence suggests that El Cuervo Aquifer may lose a smaller portion of its discharge by interbasin ground water flow to Indian Hot Springs, near the Rio Grande. Thus, El Cuervo Aquifer is a topographically closed basin that is either partially drained if a component of its ground water discharge reaches Indian Hot Springs or undrained if all its natural ground water discharge is to Laguna El Cuervo. [source] Flat colonic adenomas in Malaysia: Fact or fancy?JOURNAL OF GASTROENTEROLOGY AND HEPATOLOGY, Issue 6 2003SHANMUGARAJAH RAJENDRA Abstract Background: Some two-thirds of colorectal carcinomas arise from adenomatous polyps, and as such, screening by colonoscopy and polyp removal should significantly reduce colorectal cancer. This has not been the case, as evidenced by recent studies, which revealed that endoscopy failed to prevent up to 50% of all subsequent carcinomas. Flat or depressed adenomas, frequently reported from Japan but rarely elsewhere, might explain the ,missed carcinomas.' Detection of flat adenomas has not been previously reported from Malaysia. Methods: In the present prospective study, 426 consecutive patients underwent colonoscopic examination between March 1997 and January 2000, for a variety of bowel symptoms. The examinations were performed by an experienced endoscopist using a standard colonoscope and methylene blue dye spraying technique. Macroscopically, flat adenomas were defined using the criteria proposed by Sawada. Results: Twenty-nine adenomas were identified in 12 patients, of which 15 were polypoid and 14 were flat, with no depressed lesions. Eight polypoidal lesions and all the flat adenomas contained mild or moderate areas of epithelial dysplasia. Seven severely dysplastic polyps were identified. One Duke's A polypoidal cancer and two advanced carcinomas were also found. All the severely dysplastic lesions and Duke's A carcinomas were found in polyps greater than 10 mm in mean size. The flat adenomas were all less than 5 mm in size. Conclusions: A significant proportion of colonic adenomas in Malaysian patients appear as small flat lesions, which could easily be missed during endoscopy. Increased recognition and treatment of flat adenomas among colonoscopists is warranted. [source] Electrophysiological characterization of neural stem/progenitor cells during in vitro differentiation: Study with an immortalized neuroectodermal cell lineJOURNAL OF NEUROSCIENCE RESEARCH, Issue 8 2007M. Jelitai Abstract Despite the accumulating data on the molecular and cell biological characteristics of neural stem/progenitor cells, their electrophysiological properties are not well understood. In the present work, changes in the membrane properties and current profiles were investigated in the course of in vitro-induced neuron formation in NE-4C cells. Induction by retinoic acid resulted in neuronal differentiation of about 50% of cells. Voltage-dependent Na+ currents appeared early in neuronal commitment, often preceding any morphological changes. A-type K+ currents were detected only at the stage of network formation by neuronal processes. Flat, epithelial- like, nestin-expressing progenitors persisted beside differentiated neurons and astrocytes. Stem/progenitor cells were gap junction coupled and displayed large, symmetrical, voltage-independent currents. By the blocking of gap junction communication, voltage-independent conductance was significantly reduced, and delayed-rectifying K+ currents became detectable. Our data indicate that voltage-independent symmetrical currents and gap junction coupling are characteristic physiological features of neural stem and progenitor cells regardless of the developmental state of their cellular environment. © 2007 Wiley-Liss, Inc. [source] In vivo kinematics of total knee arthroplasty: Flat compared with concave tibial joint surfaceJOURNAL OF ORTHOPAEDIC RESEARCH, Issue 6 2000J. Uvehammer This study evaluated the influence of the geometric configuration of the tibial joint area on the kinematics of the knee. Twenty-two patients with noninflammatory arthritis and minor preoperative deformity were studied. They each received an AMK total knee replacement with retention of the posterior cruciate ligament. Eleven patients without any knee abnormalities were used as controls. The patients were stratified to either the flat (terminology of the manufacturer: standard) or concave (terminology of the manufacturer: constrained) polyethylene insert (n = 11 in each group). Knee kinematics were assessed 1 year after the operation by having the patient ascend a platform corresponding to an extension of the knee from 50 to 70° of flexion. During this motion, two film-exchangers simultaneously exposed six to 13 pairs of serial stereoradiographs. The concave geometric configuration of the tibial insert resulted paradoxically in increased anterior-posterior translations compared with the flat insect but no significant change of rotations and translations in the other directions. Compared with normal knees, the most obvious abnormality was increased anterior-posterior translations (p < 0.004). At 50° of flexion, the implants with the flat tibial polyethylene insert had displaced 2 times and the concave ones had displaced 2.5 times more posteriorly than the normal knees (p , 0.001). Less internal tibial rotation was also recorded in the flexed positions for both types of inserts compared with the normal knees (p < 0.02). Four knees in four patients, who reported symptoms of instability and abnormal knee function, showed significantly increased proximal displacement of the center of the tibial plateau in the flexed position. The findings suggest that current prosthetic designs and surgical technique do not restore normal knee kinematics and indicate that design improvements should rely on in vivo kinematic studies. [source] The Fallacies of Flatness: Thomas Friedman's The World Is FlatJOURNAL OF PHILOSOPHY OF EDUCATION, Issue 3 2007KATHLEEN KNIGHT ABOWITZ Thomas Friedman's best-selling The World is Flat has exerted much influence in the west by providing both an accessible analysis of globalisation and its economic and social effects, and a powerful cultural metaphor for globalisation. In this review, we more closely examine Friedman's notion of the social contract, the moral centre of his hopeful vision of a globalised world. While Friedman's social contract holds a more generous view of social and state obligation than his neoliberal economic analysis might otherwise allow, his fallacious assumptions about education rest on poorly argued claims about the nature of human beings, the proper aims of schooling, and meanings of justice in a globalised world. [source] Novel structure of an arrayed-waveguide grating multiplexer with flat spectral responseMICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 6 2004Tsung-Hsin Lee Abstract A novel structure of arrayed-waveguide grating (AWG) multiplexers with a graded-index free-propagation region (FPR) used to increase the wavelength pass band is presented. The 1-dB and 3-dB wavelength pass bands increase with the increase of the graded-index FPR length. Flat and broadened spectral responses are obtained by using this novel structure. © 2004 Wiley Periodicals, Inc. Microwave Opt Technol Lett 41: 444,445, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.20165 [source] Brief communication: Self-suckling in Barbary macaque (Macaca sylvanus) mothers before and after the death of their infantAMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY, Issue 2 2009Bonaventura Majolo Abstract We report here self-suckling in four wild female Barbary macaques (Macaca sylvanus), living in two troops (i.e. "Flat face" and "Large" troop) in the middle-Atlas Mountains, Morocco. The four females lost their infants due to predation or for unknown causes. Self-suckling was observed before and after the infants died in the four females living in the "Flat face" troop. When the infants were still alive, self-suckling was of short duration and it was probably a method to improve milk flow when the infant switched from one nipple to the other. After the infants died, self-suckling lasted significantly longer and the females were apparently drinking their own milk. Self-suckling was never observed among the four lactating females in the "Large" troop (including one monkey who lost her infant) and it could thus represent a cultural difference. Moreover, self-suckling after the death of an infant may be explained by the energetic and immunological benefits that a monkey may gain from drinking their own milk. Finally, self-suckling may have a stress-releasing effect on the mothers who have lost their infants. Am J Phys Anthropol, 2009. © 2009 Wiley-Liss, Inc. [source] Morphological Descriptions of New and Little-Known Benthic Ciliates from Ganghwa Tidal Flat, KoreaTHE JOURNAL OF EUKARYOTIC MICROBIOLOGY, Issue 3 2007JUN GONG ABSTRACT. Ciliates are highly diverse in the benthos where there are rare species to be unrevealed and described. By isolating species during successive and diversified cultivations, we discovered several new and interesting taxa from the top layer sediment of a muddy site in the Ganghwa tidal flat. These include three new species Spirodysteria ganghwaensis n. sp., Uronemella parafilificum n. sp., Zosterodasys minuta n. sp., and one poorly known form Loxophyllum chaetonotumBorror 1965. The morphology of live cells and infraciliature of these four species are described based on living observations, protargol impregnations, and morphometrics. Diagnoses and improved definitions are also provided. The newly established genus Spirodysteria n. g. differs from Dysteria mainly in its spirally twisted body shape. Spirodysteria kahli (Tucolesco 1962) n. comb. (formerly Dysteria kahliTucolesco 1962) has been included in this new genus. [source] I've Heard About , (A Flat, Fat, Growing Urban Experiment): Extract of Neighbourhood ProtocolsARCHITECTURAL DESIGN, Issue 4 2009François Roche Abstract Urban models are conventionally planned and intended to control urban systems. François Roche's vision is to the contrary: it is for an unpredictable organic urbanism. A biostructure develops its own adaptive behaviour, based on growth scripts and open algorithms. It is entirely reflexive, responding to human occupation and expression rather than being managed or operated at human will. Copyright © 2009 John Wiley & Sons, Ltd. [source] Carcinogenic potential of commonly used hernia repair prostheses in an experimental modelBRITISH JOURNAL OF SURGERY (NOW INCLUDES EUROPEAN JOURNAL OF SURGERY), Issue 3 2004P. Witherspoon Background: The purpose of this study was to assess the carcinogenic potential of commonly used hernia repair prostheses in an animal model. Methods: Three types of prosthetic material (monofilament polypropylene, multifilament polypropylene and expanded polytetrafluoroethylene) were implanted in CBA/H mice. Flat (1 cm2) and rolled pieces of the same material were placed subcutaneously in either flank, and a further flat piece was placed in the preperitoneal space. Owing to a high incidence of mesh extrusion in the polypropylene groups, the study protocol was modified to allow only preperitoneal placement of the material. A fourth, control, group had the pockets for the prostheses created but no material implanted. After modification of the protocol there were approximately 60 mice in each group. The mice were followed for 2 years, then killed and assessed histologically for tumour development. Results: No sarcoma developed at the site of mesh implantation in any of the groups. Conclusion: This study indicates that the risk of sarcoma formation at the site of hernia repair prostheses is very low. Copyright © 2004 British Journal of Surgery Society Ltd. Published by John Wiley & Sons, Ltd. [source] ChemInform Abstract: Competition Among fcc-Like, Double-Layered Flat, Tubular Cage, and Close-Packed Structural Motifs for Medium-Sized Aun (n = 21,28) ClustersCHEMINFORM, Issue 26 2008Dongxu Tian Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source] Morphological and immunohistochemical studies on cleft palates induced by 2,3,7,8-tetrachlorodibenzo- p -dioxin in miceCONGENITAL ANOMALIES, Issue 2 2008Kumiko Fujiwara ABSTRACT Morphological and immunohistological examinations were performed to reveal the mechanisms of cleft palate induction by 2,3,7,8-tetrachlorodibenzo- p -dioxin (TCDD). ICR strain mice 8,10 weeks of age were used in the study. TCDD was administered in olive oil on gestation day (GD) 12.5 with gastric tubes at 40 ,g/kg. From GD 13.5 to 16.5, palates were examined by scanning electron microscopy (SEM), hematoxyline,eosin (HE) staining, and immunohistochemical staining of FGFR1/2, TGF-,3, MSX1 and LHX8. In the control group, both of the palatal shelves began elevating on GD 14.0 and finished within 6 h. After the elevation, all of the shelves had completely fused with each other on GD 14.5. In the TCDD-treated group, palatal shelves elevated 1 day later than in the control group. However, all palates had elevated by GD 15.0. After the elevation, the shelves contacted each other and fused; however, they were separated on GD16.0. HE staining showed that medial edge epithelium (MEE) was thinner in the TCDD group than in the control group. MEE observed under a high magnification (×2500) exhibited filopodia-like filaments and the cells were bulged in the control group. In contrast, in the TCDD group, no filaments were observed and the cells were flat with unclear boundaries. Immunohistologically, there were no characteristic findings except for FGFR1. FGFR1 was not expressed in the TCDD group after the fusion phase (GD 14.5). TCDD induces many morphological and molecular changes to MEE cells and causes cleft palates. [source] Comparative Study of Flat and Round Collectors Using a Validated 1D Fluid Probe ModelCONTRIBUTIONS TO PLASMA PHYSICS, Issue 5-6 2006P. Peleman Abstract In the literature two different types of Gundestrup-like probe designs are proposed: design with flat and with round collectors. In this paper we study the influence of different collector shapes of Gundestrup-like probes on the accuracy of the measurement of the parallel and perpendicular flows. A one dimensional fluid probe model is used for deducing both Mach numbers of the unperturbed flow from the probe data. An analytical expression relates the plasma flow to the measured ion saturation currents collected at the upstream and downstream collecting surfaces of the probe. For flat collectors, the analytical model is validated by comparing it to a two dimensional quasi-neutral Particle In Cell (PIC) simulation code. An extension of the theoretical model then allows us to study round collectors. We performed an accuracy study which showed that systematic errors are introduced when round collectors are employed for determination of the perpendicular flow which is systematically overestimated. The error can reach more than 70% when the perpendicular flow increases and when the angle of the collecting surface with respect to the magnetic field (, , 0)is small. The correct analytical expression is applied to experimental data from Gundestrup probe measurements with round collectors on the CASTOR tokamak. The analysis shows that for these measurements the error introduced by using the expression for flat collectors remains negligible, supporting our former use of the model for flat collectors. A new advanced Gundestrup-like probe design and the motivation for the choice of flat collectors are presented. (© 2006 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Soft tissue augmentation 2006: filler fantasyDERMATOLOGIC THERAPY, Issue 3 2006Arnold William Klein ABSTRACT:, As an increasing number of patients seek esthetic improvement through minimally invasive procedures, interest in soft tissue augmentation and filling agents is at an all-time high. One reason for this interest is the availability of botulinum toxin type A, which works superbly in the upper face. The rejuvenation of the upper face has created much interest in injectable filling agents and implant techniques that work equally well in the restoration of the lower face. One of the central tenets of soft tissue augmentation is the concept of the three-dimensional face. The youthful face has a soft, full appearance, as opposed to the flat, pulled, two-dimensional look often achieved by more traditional surgical approaches. Injectable filling agents can augment and even at times, replace pulling. Additionally, with the lip as the focal center of the lower face, subtle lip enhancement is here to stay, and is in fact, the number one indication for injectable fillers. Moreover, minimally invasive soft tissue augmentation offers cosmetic enhancement without the cost and recovery time associated with more invasive procedures. As more and more physicians take interest in minimally invasive surgery, courses in cosmetic surgery techniques are becoming increasingly popular at the medical meetings of many specialties. Today, physicians have a much larger armamentarium of techniques and materials with which to improve facial contours, ameliorate wrinkles, and provide esthetic rejuvenation to the face. For a substance or device to be amenable for soft tissue augmentation in the medical community, it must meet certain criteria. It must have both a high "use" potential, producing cosmetically pleasing results with a minimum undesirable reactions, and have a low abuse potential in that widespread or incorrect or indiscriminate use would not result in significant morbidity. It must be nonteratogenic, noncarcinogenic, and nonmigratory. In addition, the agent must provide predictable, persistent correction through reproducible implantation techniques. Finally, the substance, agent or device must be approved by the U.S. Food and Drug Administration, which assures purity, safety, and accessibility, as well as much-needed information regarding use. Having a thorough understanding of the filling agents available, their indications and contraindications, as well as having thorough knowledge of implant technique are vital in providing the patient with an esthetically pleasing result. [source] ENDOSCOPIC SUBMUCOSAL DISSECTION IN THE UPPER GASTROINTESTINAL TRACT: PRESENT AND FUTURE VIEW OF EUROPEDIGESTIVE ENDOSCOPY, Issue 2009Horst Neuhaus In Western countries endoscopic mucosal resection (EMR) has been widely accepted for treatment of early Barrett`s neoplasia and flat or depressed colorectal adenomas. In contrast endoscopic submucosal dissection (ESD) is infrequently performed for several reasons. It seems to be difficult to overcome the learning curve of this difficult technique because of the low case volume of early gastric cancer. On the other hand ESD of esophageal or colorectal lesions is even more challenging and is considered to be inappropriate for learning. In addition the indication for esophageal or colorectal ESD is controversial in view of excellent results of the well established EMR technique which is less time-consuming and safer than ESD. A recent survey of leading Western endoscopy centers indicated the limited experience with ESD with a low number of cases for all potential indications. Only a few training courses have been established and the number of ongoing clinical studies is limited. Only 12 out of 340 published articles on "endoscopic mucosal dissection" were reported from Western countries. A better acceptance of ESD requires improvement of the technique to allow an easier, faster and safer approach. There is a strong demand for structured training courses and limitations of human cases to selected centers which participate in prospective trials. A close collaboration between Western and Asian centers is recommended for improvement of the ESD technique and its clinical application. [source] DIAGNOSIS OF COLONIC ADENOMAS BY NEW AUTOFLUORESCENCE IMAGING SYSTEM: A PILOT STUDYDIGESTIVE ENDOSCOPY, Issue 2007Noriya Uedo Detection and removal of adenoma by colonoscopy is an important means of preventing cancer. Autofluorescence endoscopy can visualize flat or isochromatic tumor that was not detectable by white light endoscopy by the difference in tissue fluorescence properties. Recently, a new autofluorescence imaging system (AFI, Olympus Medical Systems) using a combination of autofluorescence and reflection imaging has been developed. The purpose of the present paper was to investigate its feasibility in detection of colonic adenoma in a clinical setting. A total of 64 patients were randomly assigned to AFI or white light groups, and the distal sigmoid colon and the rectum was observed under autofluorescence or white light followed by the other mode of observation by a different endoscopist. The diagnostic ability of each method for detection of neoplasms was compared in relation to the histology as a reference standard. Sensitivity and specificity of AFI for detection of neoplastic polyps was 84% and 60%, respectively, and were similar to those of white light colonoscopy: 90% and 64%. Conventional colonoscopy overlooked more flat lesions including one adenocarcinoma. AFI has the potential to detect more flat lesions but efficacy was unable to be demonstrated in the restricted population. Further investigations are needed to determine optimum usage. [source] THE TECHNICAL FUNDAMENTALS OF ENDOSCOPIC MUCOSAL RESECTION IN THE COLON: OUR METHODDIGESTIVE ENDOSCOPY, Issue 2004Yasushi Oda ABSTRACT Endoscopic mucosal resection (EMR) is the technique used to resect flat or depressed tumors or larger tumors such as laterally spreading tumors with marginal normal mucosa. Recently, endoscopic mucosal dissection technique has been rapidly accepted, mainly in early gastric cancer in Japan. We need to have firm knowledge of EMR technique in the colon for recovery as we advance this new technique. We describe our conventional EMR method practically. EMR should be performed to locate the target lesion at down side to perform sure EMR. The ideal shape of upheaval by saline injection is hemisphere. The needle sheath and snare should be taken out a little of the endoscopy to manipulate firmly. Another technique of secure EMR is the snare manipulation. We prefer that the shape of the snare is circular and the snare is hard. It is important while trapping to press the target lesion with both the whole snare circle and the end of the sheath. With these fundamental procedures we could resect the target lesions at will. [source] Experimental determination of saltating glass particle dispersion in a turbulent boundary layerEARTH SURFACE PROCESSES AND LANDFORMS, Issue 14 2006H. T. Wang Abstract A horizontal saltation layer of glass particles in air is investigated experimentally over a flat bed and also over a triangular ridge in a wind tunnel. Particle concentrations are measured by light scattering diffusion (LSD) and digital image processing, and velocities using particle image velocimetry (PIV). All the statistical moments of the particle concentration are determined such as mean concentration, root mean square concentration fluctuations, skewness and flatness coefficients. Over the flat bed, it is confirmed that the mean concentration decreases exponentially with height, the mean dispersion height being a significant length scale. It is shown that the concentration distribution follows quite well a lognormal distribution. Over the ridge, measurements were made at the top of the ridge and in the cavity region and are compared with measurements without the ridge. On the hill crest, particles are retarded, the saltation layer decreases in thickness and concentration is increased. Downwind of the ridge, particle flow behaves like a jet, in particular no particle return flow is observed. Copyright © 2006 John Wiley & Sons, Ltd. [source] Development of a 3-dimensional LIGA process and application to fabricate a spiral microcoilELECTRICAL ENGINEERING IN JAPAN, Issue 1 2009Harutaka Mekaru Abstract LIGA process has been developed in the 2.5-dimensional world. We introduced new technologies of a 3D X-ray lithography and a worm injection molding with an unscrewing de-molding mechanism, and succeeded in the deployment of a 3D LIGA process. Furthermore, we fabricated a spiral microcoil using the 3D-LIGA process and a metallization technique combining flat and smooth electroplating and isotropic chemical etching. The microcoil diameter was 0.5 mm and the length was 1 mm. The width of coil lines was 10µm and the pitch was 20µm. Characteristics of this microcoil as an inductor combine the inductance of 91 nH and the quality factor of 5.8 at the frequency of 1 GHz. © 2008 Wiley Periodicals, Inc. Electr Eng Jpn, 166(1): 43,51, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/eej.20679 [source] The Influence of Electrode Porosity on Diffusional Cyclic VoltammetryELECTROANALYSIS, Issue 22 2008Denis Menshykau Abstract A simple generic model to predict the influence of electrode porosity on the cyclic voltammetric response of an electrode is presented. The conditions under which deviation from the behavior of a perfectly flat, planar electrode can be expected are predicted. The scope for misinterpretation when conventional flat electrode theory is applied to porous electrodes is highlighted, especially in respect to the extraction of electrode kinetic parameters and the influence of ,electrocatalysis'. [source] Recruitment pattern of muscle fibre type during flat and sloped treadmill running in Thoroughbred horsesEQUINE VETERINARY JOURNAL, Issue S36 2006D. ETO Summary Reasons for performing the study: There is little information about the muscle fibre recruitment pattern during sloped and flat track running in Thoroughbred horses. Objectives: To examine the glycogen depletion pattern of each muscle fibre type during running on a flat and sloped treadmill. Methods: Thirteen Thoroughbred horses (3,9 years old) were used. They were initially subjected to incremental exercise tests on a treadmill at 10 and 0% inclines in each horse to determine running speed at 90 and 60% VO2max. Needle biopsy samples were obtained from the middle gluteal muscle immediately after the running at 90% VO2max for 4 min and 60% VO2max for 12 min on 10% and 0% inclines treadmill. Four muscle fibre types (Types I, IIA, IIA/IIX, and IIX) were immunohistochemically identified, and optical density of Periodic Acid Schiff staining (OD-PAS) in each fibre type and the glycogen content of the muscle sample were determined by quantitative histochemical and biochemical procedures. Results: The changes in OD-PAS showed that the recruitment of all fibre types were identical after each exercise bout, i.e., 4 min running at 90% VO2max (8.4,9.4 m/sec on 10%, 13.9,14.1 m/sec on 0%), and 12 min running at 60% VO2max (5.4,6.0 m/sec on 10%, 7.9,11.2 m/sec on 0%). No significant differences were found in the recruitment patterns of each muscle fibre type between 10 and 0% inclined exercise bouts at the same exercise intensity. Conclusions: The recruitment pattern of muscle fibre type is mainly determined by exercise intensity (%VO2max) and duration, but not by running speed. Potential relevance: The results of this study indicate the possibility that up-hill running results in the same training effect as faster running on a flat track. [source] The brain weights body-based cues higher than vision when estimating walked distancesEUROPEAN JOURNAL OF NEUROSCIENCE, Issue 10 2010Jennifer L. Campos Abstract Optic flow is the stream of retinal information generated when an observer's body, head or eyes move relative to their environment, and it plays a defining role in many influential theories of active perception. Traditionally, studies of optic flow have used artificially generated flow in the absence of the body-based cues typically coincident with self-motion (e.g. proprioceptive, efference copy, and vestibular). While optic flow alone can be used to judge the direction, speed and magnitude of self-motion, little is known about the precise extent to which it is used during natural locomotor behaviours such as walking. In this study, walked distances were estimated in an open outdoor environment. This study employed two novel complementary techniques to dissociate the contributions of optic flow from body-based cues when estimating distance travelled in a flat, open, outdoor environment void of distinct proximal visual landmarks. First, lenses were used to magnify or minify the visual environment. Second, two walked distances were presented in succession and were either the same or different in magnitude; vision was either present or absent in each. A computational model was developed based on the results of both experiments. Highly convergent cue-weighting values were observed, indicating that the brain consistently weighted body-based cues about twice as high as optic flow, the combination of the two cues being additive. The current experiments represent some of the first to isolate and quantify the contributions of optic flow during natural human locomotor behaviour. [source] Functional Adhesive Surfaces with "Gecko" Effect: The Concept of Contact Splitting,ADVANCED ENGINEERING MATERIALS, Issue 5 2010Marleen Kamperman Abstract Nature has developed reversibly adhesive surfaces whose stickiness has attracted much research attention over the last decade. The central lesson from nature is that "patterned" or "fibrillar" surfaces can produce higher adhesion forces to flat and rough substrates than smooth surfaces. This paper critically examines the principles behind fibrillar adhesion from a contact mechanics perspective, where much progress has been made in recent years. The benefits derived from "contact splitting" into fibrils are separated into extrinsic/intrinsic contributions from fibril deformation, adaptability to rough surfaces, size effects due to surface-to-volume ratio, uniformity of stress distribution, and defect-controlled adhesion. Another section covers essential considerations for reliable and reproducible adhesion testing, where better standardization is still required. It is argued that, in view of the large number of parameters, a thorough understanding of adhesion effects is required to enable the fabrication of reliable adhesive surfaces based on biological examples. [source] Heterogeneous distribution of AMPA glutamate receptor subunits at the photoreceptor synapses of rodent retinaEUROPEAN JOURNAL OF NEUROSCIENCE, Issue 1 2001Iris Hack Abstract In the retina the segregation of different aspects of visual information starts at the first synapse in signal transfer from the photoreceptors to the second-order neurons, via the neurotransmitter glutamate. We examined the distribution of the four AMPA glutamate receptor subunits GluR1,GluR4 at the photoreceptor synapses in mouse and rat retinae by light and immunoelectron microscopy and serial section reconstructions. On the dendrites of OFF-cone bipolar cells, which make flat, noninvaginating contacts postsynaptic at cone synaptic terminals, the subunits GluR1 and GluR2 were predominantly found. Horizontal cell processes postsynaptic at both rod and cone synaptic terminals preferentially expressed the subunits GluR2, GluR2/3 and GluR4. An intriguing finding was the presence of GluR2/3 and GluR4 subunits on dendrites of putative rod bipolar cells, which are thought to signal through the sign-inverting metabotropic glutamate receptor 6, mGluR6. Furthermore, at the rod terminals, horizontal cell processes and rod bipolar cell dendrites showed labelling for the AMPA receptor subunits at the ribbon synaptic site or perisynaptically at their site of invagination into the rod terminal. The wide distribution of AMPA receptor subunits at the photoreceptor synapses suggests that AMPA receptors play an important role in visual signal transfer from the photoreceptors to their postsynaptic partners. [source] Multiuser detection techniques with decision statistics combining for layered space-time coded CDMA systemsEUROPEAN TRANSACTIONS ON TELECOMMUNICATIONS, Issue 4 2006Slavica Marinkovic This paper considers a low-complexity iterative multiuser detection/decoding algorithm in single user layered space-time coded (LST) systems and LST coded code division multiple access (CDMA) systems. We concentrate on the iterative multiuser receiver based on parallel interference cancellation (PIC) and compare it to the iterative PIC with the minimum means square error (MMSE) detection, as these two approaches seem to be most efficient in meeting the performance-complexity trade-off required by practical systems. In iterative PIC structures, a decision statistics bias severely limits the system performance for a large number of multiple access (MA) or multiple-input multiple-output (MIMO) interferers. A decision statistics combining (DSC) method, originally proposed for iterative PIC receivers in CDMA systems, is used to minimize the bias effect in space-time coded systems for iterative PIC receivers. Significant performance improvements have been confirmed with the iterative PIC receiver with DSC (PIC-DSC) relative to the standard iterative PIC receivers in LST systems for both flat and frequency selective fading channels. This advantage is retained in layered coded CDMA systems as well. The proposed iterative PIC-DSC detector approaches the performance of the much more complex iterative PIC-MMSE receiver. Copyright © 2006 AEIT. [source] Expression and functional characterization of P2Y1 and P2Y12 nucleotide receptors in long-term serum-deprived glioma C6 cellsFEBS JOURNAL, Issue 8 2007Patryk Krzemi We characterized the expression and functional properties of the ADP-sensitive P2Y1 and P2Y12 nucleotide receptors in glioma C6 cells cultured in medium devoid of serum for up to 96 h. During this long-term serum starvation, cell morphology changed from fibroblast-like flat to round, the adhesion pattern changed, cell-cycle arrest was induced, extracellular signal-regulated kinase (ERK1/2) phosphorylation was reduced, Akt phosphorylation was enhanced, and expression of the P2Y12 receptor relative to P2Y1 was increased. These processes did not reflect differentiation into astrocytes or oligodendrocytes, as expression of glial fibrillary acidic protein and NG2 proteoglycan (standard markers of glial cell differentiation) was not increased during the serum deprivation. Transfer of the cells into fresh medium containing 10% fetal bovine serum reversed the changes. This demonstrates that serum starvation caused only temporary growth arrest of the glioma C6 cells, which were ready for rapid division as soon as the environment became more favorable. In cells starved for 72 and 96 h, expression of the P2Y1 receptor was low, and the P2Y12 receptor was the major player, responsible for ADP-evoked signal transduction. The P2Y12 receptor activated ERK1/2 kinase phosphorylation (a known cell proliferation regulator) and stimulated Akt activity. These effects were reduced by AR-C69931MX, a specific antagonist of the P2Y12 receptor. On the other hand, Akt phosphorylation increased in parallel with the low expression of the P2Y1 receptor, indicating the inhibitory role of P2Y1 in Akt pathway signaling. The shift in nucleotide receptor expression from P2Y1 to P2Y12 would appear to be a new and important self-regulating mechanism that promotes cell growth rather than differentiation and is a defense mechanism against effects of serum deprivation. [source] Seed characters and testa sculptures of some Iranian Allium L. species (Alliaceae)FEDDES REPERTORIUM, Issue 5-6 2009Fatemeh Neshati Seeds taken from herbarium specimens of 20 Allium taxa were investigated. The seeds of all species were black ranging from 1.7 mm (A. lamondiae) to 4 mm (A. altissimum and A. stipitatum) in length and 1 mm (A. lamondiae) to 3 mm (A. altissimum) in width. So, A. lamondiae had the smallest and A. altissimum the largest seeds. In the mean, the members of subg. Melanocrommyum had somewhat larger and the species of sect. Avulsea somewhat smaller seeds than most species belonging to other groups. The shape was generally ovate or variants of it and showed only slight differences between members of different sections. The seed coat pattern was more variable. Most common were convex, granulate periclinal walls bearing several verrucae. Only A. borszczowii showed flat, densely granulate periclinal walls without verrucae, and A. bungei and A. joharchii had somewhat verruca-like aggregating grana. The majority of the species investigated showed S-like, rarely Omega-like, undulated anticlinal walls with variable wavelengths and amplitudes. The testa cells of A. joharchii showed transitions to straight anticlinal walls. More or less straight anticlinal walls in A. kopetdagense, A. paradoxum, A. barsczewskii, and A. scabriscapum were connected with the presence of a strip-like widened and transversally striated intercellular region covering these walls. The seed coat pattern of most species corresponded well to earlier reports of the same or closely related species, or was at least already reported for not related Allium species. Only A. borszczowii and A. monophyllum displayed testa types earlier not reported. (© 2009 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Lipid biomarkers, pigments and cyanobacterial diversity of microbial mats across intertidal flats of the arid coast of the Arabian Gulf (Abu Dhabi, UAE)FEMS MICROBIOLOGY ECOLOGY, Issue 3 2008Raeid M.M. Abed Abstract Variations in morphology, fatty acids, pigments and cyanobacterial community composition were studied in microbial mats across intertidal flats of the arid Arabian Gulf coast. These mats experience combined extreme conditions of salinity, temperature, UV radiation and desiccation depending on their tidal position. Different mat forms were observed depending on the topology of the coast and location. The mats contained 63 fatty acids in different proportions. The increased amounts of unsaturated fatty acids (12,39%) and the trans/cis ratio (0.6,1.6%) of the cyanobacterial fatty acid n- 18:1,9 in the higher tidal mats suggested an adaptation of the mat microorganisms to environmental stress. Chlorophyll a concentrations suggested lower cyanobacterial abundance in the higher than in the lower intertidal mats. Scytonemin concentrations were dependent on the increase in solar irradiation, salinity and desiccation. The mats showed richness in cyanobacterial species, with Microcoleus chthonoplastes and Lyngbya aestuarii morphotypes as the dominant cyanobacteria. Denaturing gradient gel electrophoresis patterns suggested shifts in the cyanobacterial community dependent on drainage efficiency and salinity from lower to higher tidal zones. We conclude that the topology of the coast and the variable extreme environmental conditions across the tidal flat determine the distribution of microbial mats as well as the presence or absence of different microorganisms. [source] | ||||||||||||||||||||||||||||||||||