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Selected AbstractsInfluence of bacitracin on microbial functions in the gastrointestinal tract of horsesEQUINE VETERINARY JOURNAL, Issue 4 2000E. Collinder Summary This study investigated the influence of zinc bacitracin on the intestinal flora of horses. The functionally active intestinal flora was examined in 6 horses during treatment with zinc bacitracin. Utilising gas chromatography, spectrophotometry, gel electrophoresis and paper chromatography, samples were analysed on biochemical markers reflecting the action of parts of the intestinal flora. The following 5 flora-related functions were studied in faecal samples and intestinal samples from different sections of the hindgut: conversion of cholesterol to coprostanol and of bilirubin to urobilinogens, degradation of mucin and of ,-aspartylglycine and inactivation of tryptic activity. Conversion to coprostanol, conversion to urobilinogens and degradation of mucin were affected by treatment of zinc bacitracin and conversion to coprostanol was most sensitive. All functions were normalised in a short time, in contrast to man and rats. Differences in environmental exposures are probably the reason for a more rapid normalisation of the intestinal flora functions in horses. [source] Principles of Highly Resolved Determination of Texture and Microstructure using High-Energy Synchrotron Radiation,ADVANCED ENGINEERING MATERIALS, Issue 6 2009Helmut Klein Abstract Diffraction imaging with hard X-rays (high-energy synchrotron radiation) using the detector sweeping techniques allows measurement of the texture and microstructure of polycrystalline materials with high orientation- and location-resolution. These techniques provide continuous two-dimensional images of different sections and projections of the six-dimensional "orientation-location" space. For the high orientation resolution case, it is possible to measure the orientation and location coordinates of up to 105 individual grains simultaneously. From these parameters, the grain size and shape can also be obtained, yielding the complete orientation stereology of the polycrystalline aggregate, which is required for its complete characterization. For the high location resolution case, the intensity at any point of the diagrams corresponds to a pole density as a function of the orientation-location space. [source] A fatigue and creep study in austenitic stainless steel 316L used in exhaust pipes of naval gas turbinesFATIGUE & FRACTURE OF ENGINEERING MATERIALS AND STRUCTURES, Issue 9 2004R. F. MARTINS ABSTRACT Exhaust pipes of naval gas turbines are made of thin wall tubing of stainless steel grade AISI 316L. The tubes are fabricated by butt welding of different sections with longitudinal and circumferential joints. The plate thickness is about 4.0 mm, and the working temperature varies between 600 °C and 400 °C in the critical zones of the pipe, in the lower and central areas, respectively. The loadings in the tube induce high-temperature fatigue and creep-fatigue cracks have nucleated and propagated in the tube near some welded joints. The paper presents FCGR data obtained in CT specimens of used material taken from the pipes and tested at RT, 335, 500 and 600 °C. Preliminary creep data obtained in tension, in thin-sheet specimens (about 4 mm thickness), also taken from the conduct wall and tested at 500, 550 and 600 °C are also given. These results are crucial to perform a fatigue-creep interaction life assessment of the critical parts of the structure in the near future. Finally, the paper presents results of research work to investigate carbide precipitation and formation in virgin thin-sheet specimens subjected to several types of thermal exposures. In some cases, 3,4 d was the time interval between exposures. Grain size measurements were carried out together with microstructural observations in the SEM. The influence of time, temperature and time interval between thermal exposures was assessed comparing the microstructures. [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] The cation and silica chemistry of a Subandean river basin in western AmazoniaHYDROLOGICAL PROCESSES, Issue 7 2002J. A. Sobieraj Abstract We sampled river water at 13 locations in the Pichis basin, a 10 500 km2 large rainforest-covered drainage basin in Peru, to assess the influence of lithological variability and seasonality on water chemistry. The concentrations of major cations and silica show a strong seasonal dependence and a remarkable variability over short distances that is only weakly reduced in the wet season; cation concentrations in streams differ by up to 100% within a few kilometres. The lowest cation concentrations were associated with relatively cation-depleted upper Tertiary and lower Quaternary formations, whereas relatively cation-rich lower Tertiary and Jurassic formations left a clear calcium and sodium signal in the respective rivers. Cluster analysis, in conjunction with boxplots, suggests that the sampling locations can be segregated into three groups based on similarities of their geochemical signals. According to the previously defined criteria, one river is classified as a Group 2 river with 200 < TZ+ < 450 µeq/L, whereas all other rivers fall into Group 3 with 450 < TZ+ < 3000 µeq/L (where TZ+ refers to the total cation charge). Based on a comparison with other studies at different sections of the Amazon mainstem, the river chemistry of our study area is relatively enriched in K+, Mg2+ and Ca2+, and, consequently, has a higher TZ+ value, while being relatively depleted in silica. The influence of lithological variability on water chemistry must be considered in land-use change studies even at watershed areas of 26,3382 km2. Copyright © 2002 John Wiley & Sons, Ltd. [source] Calculation of nonlinear aerodynamic characteristics of a wing using a 3-D panel methodINTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN FLUIDS, Issue 1 2008Jeonghyun Cho Abstract The nonlinear aerodynamic characteristic of a wing is investigated using the frequency-domain panel method. To calculate the nonlinear aerodynamic characteristics of a three-dimensional wing, the iterative decambering approach is introduced into the frequency-domain panel method. The decambering approach uses the known nonlinear aerodynamic characteristic of airfoil and calculates two-variable decambering function to take into consideration the boundary-layer separation effects for the each section of the wing. The multidimensional Newton iteration is used to account for the coupling between the different sections of wing. The nonlinear aerodynamic analyses for a rectangular wing, a tapered wing, and a wing with the control surface are performed. Present results are given with experiments and other numerical results. Computed results are in good agreement with other data. This method can be used for any wing having different nonlinear aerodynamic characteristics of airfoil. The present method will contribute to the analysis of aircraft in the conceptual design because the present method can predict the nonlinear aerodynamic characteristics of a wing with a few computing resources and significant time. Copyright © 2007 John Wiley & Sons, Ltd. [source] The importance of values research for nonprofit organisations: the motivation-based values of museum visitorsINTERNATIONAL JOURNAL OF NONPROFIT & VOLUNTARY SECTOR MARKETING, Issue 2 2001Maree Thyne Marketing is very important to nonprofit organisations, and museums, being nonprofits, need to consider different market segments when designing and implementing their strategic and marketing plans. Marketing has traditionally been linked to concepts of profitability and providing a competitive edge, however with nonprofit organisations, marketing needs to focus on customer service. To achieve the best customer service, the organisation needs to know what the customer wants. Therefore this paper advocates that research on museums move away from demographic segmentation and factual recall, to psychographic segmentation and values. This paper discusses exploratory research undertaken on the Otago Museum, New Zealand, which looks at the motivation-based values of the museum patrons. The most important finding in this study is the prevalence of socially oriented values (being with friends and family), whereas traditionally a museum visit has been linked to more individualistic values, such as education and knowledge. These findings have important implications for museum managers (and other nonprofit organisations) in that they show the value of psychographic segmentation. A museum, and other arts organisations, can decide if they will target one particular segment, for example, families, or if they will design their museum with quite different sections that will appeal to different target markets. Copyright © 2001 Henry Stewart Publications [source] Reducing the density of breeding gulls influences the pattern of recruitment of immature Atlantic puffins Fratercula arctica to a breeding colonyJOURNAL OF APPLIED ECOLOGY, Issue 3 2003S. K. Finney Summary 1By acting as both competitors and predators, gulls (Larus spp.) are generally considered to reduce significantly the attractiveness of potential breeding sites for other birds. This perceived threat posed by gulls to other breeding birds has led to the implementation of gull control procedures at many seabird colonies. However, the extent to which reducing gull numbers benefits other species has received little rigorous scientific investigation. 2During a gull control programme (1972,89), gull nest density on the Isle of May, south-east Scotland, was reduced by between 30% and 100% in different sections of the island. Following termination of the original programme in 1989, several sections were maintained as gull-free by repeated removal of nests. 3We used data collected over a 23-year period to determine the extent to which the spatial variation in puffin Fratercula arctica recruitment was influenced by changes in the density and spatial distribution of breeding gulls resulting from the control programme. 4The presence of breeding gulls significantly affected the pattern of recruitment of puffins to the colony. Puffin recruitment rate was highest in the sections of the island where gull nest density was low. Gull density explained 21% of the variation in puffin recruitment rate. 5These results suggest that the reduction in the number of breeding gulls substantially increased the attractiveness of areas of the colony as breeding sites for puffins, and is thus likely to have played an important role in the pattern of expansion of the puffin population on the island. 6Synthesis and applications. Following a recent increase in the conservation status of both herring L. argentatus and lesser black-backed gulls L. fuscus, there has been a move to make management decisions more objective. This has highlighted the need for studies such as this, aimed at assessing the impact of gulls and their removal on other breeding birds, to ensure that any future control programmes are both necessary and effective. [source] Application of a Service Climbing Robot with Motion Planning and Visual SensingJOURNAL OF FIELD ROBOTICS (FORMERLY JOURNAL OF ROBOTIC SYSTEMS), Issue 4 2003Jian Zhu This paper describes an application of a service climbing robot aimed to clean the glass wall of high-rise buildings. The robot utilizes suction cups to adhere to the glass and moves with a translational mechanism to follow a predetermined path in cleaning the whole glass surface. By a flexible waist, the robot can adjust its posture. The robot has the ability to cross the window frame to clean different sections of the glass wall. A visual sensing system, composed of an omnidirectional CCD camera and two laser diodes, enables the robot to measure its orientation and the distance between the robot and the window frame. The real-time applications and some experimental results demonstrate the effectiveness of the developed system. © 2003 Wiley Periodicals, Inc. [source] Effects of Ligula intestinalis on habitat use, predation risk and catchability in European minnowsJOURNAL OF FISH BIOLOGY, Issue 4 2001J. Museth The frequency of infection with Ligula intestinalis (Cestoda) in European minnow Phoxinus phoxinus, in a subalpine lake in Eastern Norway, did not differ between vegetated shoreline, exposed shoreline and non-vegetated localities >50 m from the shoreline. There was no difference in the vertical distribution of infected and uninfected individuals. The frequency of infection was higher among minnows in brown trout Salmo trutta stomachs than among those obtained by gillnets and minnow traps, suggesting that brown trout selectively preyed on infected minnows. Prevalence of infection decreased with increasing fish size, probably due to selective mortality among parasitized individuals. Within a given length-class, minnows captured by different sections of multi-mesh gillnets showed a significant increase in the frequency of infection with increasing mesh-size. Apparently, parasitized individuals had a higher catchability in gillnets due to increased girth caused by the plerocercoid in the body cavity. This may partly explain why the observed prevalence of infection was several times higher among minnows captured by gillnets than by minnow traps. [source] ACTIVITY DISTRIBUTION OF DIGESTIVE PROTEASES FROM NEMIPTERUS VIRGATUS AND THEIR RESPONSES TO pH VALUE AND TEMPERATUREJOURNAL OF FOOD PROCESS ENGINEERING, Issue 1 2008HONG TAO ABSTRACT In the present study, three groups (I,III) of Nemipterus virgatus, with average body weights of 154.36, 250.72 and 329.09 g, respectively, were used to investigate the changes in the activity and distribution of digestive proteases in different organs and sections of the digestive tract. Another group of N. virgatus (average body weight of 188.41 g) was used to analyze the changes in the activity of digestive proteases in response to various pH values and temperatures. The activity of digestive proteases in all analyzed organs increased with the increase of body weight at the range of 154.36,329.09 g. The activities of digestive proteases in the different sections of the digestive tract were compared, and a similar change was found among groups I,III. The activities of digestive proteases from various organs were in a descending order: pylorus ceca > stomach > foregut > midgut > hindgut > hepatopancreas. Through observing the zymograms of substrate,sodium dodecil sulphate-polyacrylamide gel electrophoresis, many kinds of digestive proteases could be found in different organs and the varieties were changed with the change of body weight. Two peaks in the diagram between protease activity and pH value were found at pH 3.0 and 10.0, respectively. The activity under alkaline condition was 60% higher than that under acidic condition. The optimal temperature for protease activity was 50C, while the protease activity at 10C was only 30% of that at 50C. PRACTICAL APPLICATIONS Nemipterus virgatus is one of the most important commercial fishes in the East China Sea and South China Sea. The digestive tract of N. virgatus is rich in digestive proteases and they can be employed as important biotechnological tools. The activities of digestive proteases from various organs and the effects of pH value and temperature on them were investigated in this study. The effect of body weight of N. virgatus was also evaluated. All these information would be helpful to extensively utilize this resource for the fish process industry. [source] On the electrostatic equilibrium of granular flow in pneumatic conveying systemsAICHE JOURNAL, Issue 11 2006Jun Yao Abstract An analytical methodology involving the concept of "electrostatic equilibrium" is developed for granular flow in pneumatic conveying systems. The methodology can be used for estimation of the electrostatic field distribution at various sections of the system and explanation of the mechanisms involved for various electrostatic phenomena observed. For all cases conducted in the conveying system, there was a "charging time" required for the system to reach the state of "electrostatic equilibrium." Experiments conducted at different sections of the system showed that the time required increased in the order: horizontal pipe, vertical pipe, and pipe bend. Through a physical analysis, it is deduced that electrostatic equilibrium is related to the granules' behavior and local flow characteristics. In general, a longer time duration taken to reach equilibrium corresponds to a process with more complicated granular flow patterns. In the electrostatic equilibrium state, the field distribution shows the highest electrostatic field strength near the pipe wall, and this field strength degrades from the pipe wall to the pipe center. At various pipe sections, the highest strength occurs at the bend, in accord with observations that electric sparking first occurs at that location within the entire pneumatic conveying system. In the vertical pipe, granular distribution was measured using electrical capacitance tomography (ECT), and granular velocities were cross-referenced with those using particle image velocimetry (PIV). The electrostatic force at low air flow rates is found to be the primary cause for granules sticking to the pipe wall and results in the formation of the half-ring or ring structure. The state of electrostatic equilibrium is physically influenced by several elements in conveying systems. In a cyclic conveying system, a new pipe (or low humidity or no antistatic agent) tends to expedite the process to reach electrostatic equilibrium and attain high magnitude of electrostatic current at the state. In a non-cyclic horizontal conveying system, a thin film (pipe) is found to prolong the process duration to reach equilibrium, while the case with charged film (pipe) takes shorter duration to do so. © 2006 American Institute of Chemical Engineers AIChE J, 2006 [source] Cell wall phenolics of white and green asparagusJOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE, Issue 6 2005Rocío Rodríguez Abstract Cinnamic acids influence physical and textural attributes of plant foods as they play an important role in lignification and cross-linking of cell-wall polymers. Several trans -cinnamic acids have been detected in asparagus cell wall (CW), and, of these, amounts of ferulic acid (FA) and its dehydrodimers have been found to increase significantly during post-harvest storage. The distribution of these compounds along the different sections of white and green spears, as well as their modifications during postharvest storage, has been investigated. It has been observed that the cell walls from the apical, middle and lower sections of the green spears contain equivalent amounts of FA derivatives (about 400 µg g,1 CW), while these compounds are mainly located in the middle (681 µg g,1 CW) and lower section (975 µg g,1 CW) of the white ones. During asparagus post-harvest storage a general increase of FA monomers and dimers took place that affected every section of both green and white spears. Major changes occurred in the middle and lower sections of the white asparagus, where the amounts of ferulic derivatives increased to 1700 and 1678 µg g,1 CW after storage. A similar but less pronounced trend was observed for the green spears. Copyright © 2005 Society of Chemical Industry [source] Development and characterization of microsatellite markers for a monoecious Ficus species, Ficus insipida, and cross-species amplification among different sections of FicusMOLECULAR ECOLOGY RESOURCES, Issue 3 2006H. VIGNES Abstract The animal-mediated pollination and seed-dispersal mutualisms of Ficus species give them key roles in tropical ecosystems, but may make them vulnerable to habitat fragmentation. The development of highly polymorphic markers is needed to analyse their genetic diversity and investigate the effects of fragmentation on gene flow. Of thirteen microsatellite loci isolated from Ficus insipida, a monoecious species in French Guiana, eleven were polymorphic (two to six alleles each). High levels of variation were found among loci; expected heterozygosities ranged from 0.151 to 0.715. All markers revealed a broad cross-species affinity when tested in 23 other Ficus species. [source] Dynamics of petroleum markets in OECD countries in a monthly VAR,VEC model (1995,2007)OPEC ENERGY REVIEW, Issue 1 2008Mehdi Asali This paper contains some results of a study in which the dynamics of petroleum markets in the Organization for Economic Cooperation and Development (OECD) is investigated through a vector auto regression (VAR),vector error correction model. The time series of the model comprises the monthly data for the variables demand for oil in the OECD, WTI in real term as a benchmark oil price, industrial production in OECD as a proxy for income and commercial stocks of crude oil and oil products in OECD for the time period of January 1995 to September 2007. The detailed results of this empirical research are presented in different sections of the paper; nevertheless, the general result that emerges from this study could be summarised as follows: (i) there is convincing evidence of the series being non-stationary and integrated of order one I(1) with clear signs of co-integration relations between the series; (ii) the VAR system of the empirical study appears stable and restores its dynamics as usual, following a shock to the rate of changes of different variables of the model, taking between five and eight periods (months in our case); (iii) we find the lag length of 2 as being optimal for the estimated VAR model; (iv) significant impact of changes in the commercial crude and products' inventory level on oil price and on demand for oil is highlighted in our empirical study and in different formulations of the VAR model, indicating the importance of the changes in the stocks' level on oil market dynamics; and (v) income elasticity of deman for oil appears to be prominent and statistically significant in most estimated models of the VAR system in the long run, while price elasticity of demand for oil is found to be negligible and insignificant in the short run. However, while aggregate oil consumption does not appear to be very sensitive to the changes of oil prices (which is believed to be because of the so-called ,rebound effect' of oil (energy) efficiency in the macro level) in the macro level, the declining trend of oil intensity (oil used for production of unit value of goods and services), particularly when there is an upward trend in oil price, clearly indicates the channels through which persistent changes in oil prices could affect the demand for oil in OECD countries. [source] Examination of an unusual grain boundary in CaF2PHYSICA STATUS SOLIDI (C) - CURRENT TOPICS IN SOLID STATE PHYSICS, Issue 11 2004M.E. Msall Abstract We have examined a grain boundary in CaF2 using Phonon Imaging and Electron Backscatter Diffractometry (EBSD). Unlike the <111> twin boundary typically found in CaF2, the crystal grains on either side of the boundary are not simply related to any principle symmetry directions, and are not related to one another by symmetry operations of the cubic group. In spite of the high degree of misalignment of the crystalline lattices, phonons can pass this grain boundary without excessive energy loss. Phonon images of samples taken from different sections of the grain boundary show that the structural properties of the grain boundary are constant over a large area. Computer simulations of phonon scattering at the interface based on acoustic mismatch models demonstrate that the caustic positions are sensitive to small changes in the relative orientation of the two pieces and to the projection of the grain boundary on the image plane. EBSD gives the needed high precision measurement of the relative orientation, resulting in a superior model of phonon transmission through this very asymmetric interface. (© 2004 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Distribution of benthic communities in the fjord-like Bathurst Channel ecosystem, south-western Tasmania, a globally anomalous estuarine protected areaAQUATIC CONSERVATION: MARINE AND FRESHWATER ECOSYSTEMS, Issue 4 2010Neville S. Barrett Abstract 1.Benthic assemblages in the fjord-like Bathurst Channel estuarine system, south-western Tasmania, vary over horizontal scales of 1,5,km and vertical scales of 1,10,m. Multivariate analysis indicated a total of eight major assemblages that characterize different sections and depths of the channel. 2.Because tannins in the low-salinity surface water layer block light, foliose algae reach 5,m depth in the marine western region but do not penetrate below 1,m in the east. By contrast, sessile invertebrates are most abundant below 5,m depth in the west and below 2,m in the east. Deeper assemblages are unlikely to be continuous with assemblages in deeper waters off the Tasmanian coast as they are highly constrained by depth within particular sections of the estuary. 3.While the species composition of the Bathurst Channel biota is most similar to that found elsewhere in Tasmania, the structural character of the biota in terms of major taxonomic groups is more closely allied to that found in fjords of south-western Chile and south-western New Zealand. These three regions all possess wilderness settings, high rainfall that is channelled through estuaries as a low-salinity surface layer, deep-water emergence of fauna, rapid change in biotic communities over short horizontal and vertical distances, and high levels of local endemism. They also include some of the most threatened aquatic ecosystems on earth due to increasing human activity from a near pristine base, and the potentially catastrophic impacts of climate change. Copyright © 2009 John Wiley & Sons, Ltd. [source] A Malaysia,United States free trade agreement: Malaysian media and domestic resistanceASIA PACIFIC VIEWPOINT, Issue 1 2009Sandra SmeltzerArticle first published online: 25 MAR 200 Abstract This article examines Malaysia's civil society resistance to a bilateral free trade agreement (FTA) with the United States, focusing specifically on the role played by domestic mainstream and alternative media in raising awareness of trade negotiations. While challenges to a Malaysia,United States FTA may appear muted , especially if compared with the outpouring of dissent witnessed on the streets of Thailand and South Korea against similar deals with the United States , Malaysia's civil society agents have employed a range of mechanisms to oppose the agreement. Although these activists have focused their efforts on different sections of the proposed FTA , from intellectual property rights to food sovereignty to government procurement procedures , all share a common call for greater transparency in the negotiation process and greater public and parliamentary consultation. This article takes a critical look at who is involved in these resistance efforts, their key issues of concern, limitations to their success, and, most importantly, their relationship with and use of local media. [source] Probing bacterial nucleoid structure with optical tweezersBIOESSAYS, Issue 3 2007Charles J. Dorman The H-NS protein is a major component of the nucleoid in Gram-negative bacterial cells. It is a global regulator of transcription that affects the expression of many genes, including virulence genes in pathogenic species. At a local level, it facilitates the formation of nucleoprotein structures that repress transcriptional promoter function. H-NS can form bridges between different DNA molecules or between different sections of the same molecule, allowing it to compact and impose structure on the nucleoid. A recent paper by Dame et al.1 reports new insights into H-NS-mediated DNA bridging that were obtained using an optical tweezers device. BioEssays 29: 212,216, 2007. © 2007 Wiley Periodicals, Inc. [source] Characteristics of Underground Water Flow at Different Water Levels in Tianshengan Karst Area, Yunnan, ChinaACTA GEOLOGICA SINICA (ENGLISH EDITION), Issue 1 2010Janja KOGOV Abstract: Three tracing tests from the same injection point executed at low, medium, and high water levels in the karst aquifer near Tianshengan village, Lunan Stone Forest, Yunnan Province, China, have revealed the basic properties of underground water flow. They showed the general directions of water flows; tracer concentrations were observed at six successive points allowing for the calculation of apparent dominant flow velocities at these sections towards the Dalongtan karst spring. For the high water level, the discharge between single sections was between two and 10 times greater than that at low water level. For the medium water level, the flow velocity at different sections was between 1.4 and 3.7 times faster than that at low water level; and for high water level, it was between 1.3 and 2.7 times faster than that at medium water level. The fastest water flow appeared at the first section (23 cm/s at medium water level); and the slowest (0.6 cm/s at low water level) appeared where water flow must cross the Tianshengan fault (north-south direction), and later, a layer of 20-30 m thickness of quartz sandstone and shale clay-stones. It was also possible to calculate the recovery of the tracer for point 4, Dakenyan, where discharge was measured. At the medium water level, 50% of the injected tracer was detected a half-day after its first appearance and at low water level after more than 3 days. The previously published research illustrates the transport velocities of possible contaminants and their solubilities in water at different hydrological conditions. [source] Which region of the median palate is a suitable location of temporary orthodontic anchorage devices?CLINICAL ORAL IMPLANTS RESEARCH, Issue 3 200920 years, A histomorphometric study on human cadavers aged 1 Abstract Introduction: Endosseus implants can provide a reliable anchorage during orthodontic treatment. The midpalatal structures around the sutura palatina mediana (SPM) are of special interest due to increasing placement of orthodontic implants in this area. Knowledge about the osseous conditions at this site is necessary to predict the expected degree of implant osseointegration. Methods: The upper jaws of 10 human cadavers, aged 15,20 years, were decalcified, and cross-sectional specimens were obtained from four anterior-to-posterior palatal regions for histomorphometric analysis. The analyses focused on the amount of bone and the width of the SPM to determine the anatomical requirements for reliable insertion of palatal implants. Results: Bone density [bone-volume (BV)/ tissue-volume (TV)] in all measured areas was 40,60%. The maximum density was measured at the level of the first premolars (54.9±5.9%) and the least values (44.2±9.6%) were measured at the level of the interconnecting line of the canines. The mean width of the SPM varies from 1.2 to 0.3 mm in different sections of the palate. In the median sagittal plane, the mean values of bone height to nasal cavity reached >5 mm as far as the level distal of the second premolars. Bone height 2 mm paramedian to the SPM decreased consistently from anterior (4.3±0.9 mm) to posterior (2.5±0.8 mm). Conclusions: Our results indicate that the amount and quality of bone along the anterior palatal midline in 15-to-20-year olds is sufficient for orthodontic implantation. Even implantation posterior to the recommended first premolar level, at which orthodontic implants are most often placed, may be suitable. There are some limitations, however, due to small number of samples and variations of anatomical structures. [source] | ||||||||||||||||||||||||||||