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Sample records for predict bone erosions

  1. MRI of the wrist and finger joints in inflammatory joint diseases at 1-year interval: MRI features to predict bone erosions

    International Nuclear Information System (INIS)

    Savnik, Anette; Malmskov, Hanne; Graff, Lykke B.; Danneskiold-Samsoee, Bente; Bliddal, Henning; Thomsen, Henrik S.; Nielsen, Henrik; Boesen, Jens

    2002-01-01

    The aim of this study was to assess the ability of MRI determined synovial volumes and bone marrow oedema to predict progressions in bone erosions after 1 year in patients with different types of inflammatory joint diseases. Eighty-four patients underwent MRI, laboratory and clinical examination at baseline and 1 year later. Magnetic resonance imaging of the wrist and finger joints was performed in 22 patients with rheumatoid arthritis less than 3 years (group 1) who fulfilled the American College of Rheumatology (ACR) criteria for rheumatoid arthritis, 18 patients with reactive arthritis or psoriatic arthritis (group 2), 22 patients with more than 3 years duration of rheumatoid arthritis, who fulfilled the ACR criteria for rheumatoid arthritis (group 3), and 20 patients with arthralgia (group 4). The volume of the synovial membrane was outlined manually before and after gadodiamide injection on the T1-weighted sequences in the finger joints. Bones with marrow oedema were summed up in the wrist and fingers on short-tau inversion recovery sequences. These MRI features was compared with the number of bone erosions 1 year later. The MR images were scored independently under masked conditions. The synovial volumes in the finger joints assessed on pre-contrast images was highly predictive of bone erosions 1 year later in patients with rheumatoid arthritis (groups 1 and 3). The strongest individual predictor of bone erosions at 1-year follow-up was bone marrow oedema, if present at the wrist at baseline. Bone erosions on baseline MRI were in few cases reversible at follow-up MRI. The total synovial volume in the finger joints, and the presence of bone oedema in the wrist bones, seems to be predictive for the number of bone erosions 1 year later and may be used in screening. The importance of very early bone changes on MRI and the importance of the reversibility of these findings remain to be clarified. (orig.)

  2. Paradiaphyseal calcific tendinitis with cortical bone erosion.

    Science.gov (United States)

    Fritz, P; Bardin, T; Laredo, J D; Ziza, J M; D'Anglejan, G; Lansaman, J; Bucki, B; Forest, M; Kuntz, D

    1994-05-01

    To determine the clinical, radiologic, and histologic features of calcific tendinitis with cortical bone erosion. The records of 6 patients with paradiaphyseal calcific tendinitis and adjacent bone cortex erosion were reviewed. Calcific tendinitis involved the linea aspera in 4 patients, the bicipital groove in 1 patient, and the deltoid insertion in another. Calcium deposits were associated with cortical bone erosions, revealed on plain radiographs in 4 patients and computed tomography scans in 2. Bone scans were performed in 2 patients and showed local hyperfixation of the isotope. In 4 patients, suspicion of a neoplasm led to a biopsy. Calcium deposits appeared to be surrounded by a foreign body reaction with numerous giant cells. Apatite crystals were identified by transmission electron microscopy and elemental analysis in 1 surgical sample. Paradiaphyseal calcific tendinitis with cortical bone erosion is an uncommon presentation of apatite deposition disease.

  3. Erosions of the Petrous Temporal Bone

    African Journals Online (AJOL)

    tumours of the parotid gland; tumours of the paranasal sinuses; and tumours of ... showed severe erosion of the anterior and posterior walls and floor of the external .... sphenoid sinus, the pituitary fossa, and the greater and lesser wings of the ...

  4. Numerical Modelling and Prediction of Erosion Induced by Hydrodynamic Cavitation

    Science.gov (United States)

    Peters, A.; Lantermann, U.; el Moctar, O.

    2015-12-01

    The present work aims to predict cavitation erosion using a numerical flow solver together with a new developed erosion model. The erosion model is based on the hypothesis that collapses of single cavitation bubbles near solid boundaries form high velocity microjets, which cause sonic impacts with high pressure amplitudes damaging the surface. The erosion model uses information from a numerical Euler-Euler flow simulation to predict erosion sensitive areas and assess the erosion aggressiveness of the flow. The obtained numerical results were compared to experimental results from tests of an axisymmetric nozzle.

  5. Cavitation erosion prediction on Francis turbines

    Energy Technology Data Exchange (ETDEWEB)

    Bourdon, P.; Farhat, M.; Simoneau, R.; Lavigne, P. [Hydro-Quebec, Montreal, PQ (Canada); Pereira, F.; Dupont, P.; Avellan, F.; Caron, J.F. [IMHEF/EPFL, (France); Dorey, J.M.; Archer, A. [Electricite de France (EDF), 92 - Clamart (France). Dir. des Etudes et Recherches; and others

    1997-12-31

    On-board aggressiveness measurement methods were tested on a severely eroded prototype blade of a 266 MW Francis turbine: pressure, pit counting, DECER electrochemical and vibration measurements. The test program provided understanding of the heterogeneous erosion distribution of the prototype blades and quantitative data for comparison in subsequent tests on the model of the machine. Model tests and flow analysis were also performed, to detect cavitation on a Francis turbine model. The results are compared to those obtained on the prototype measurements. The model used for that study is built on the basis of a geometrical recovery of one of the most eroded blade of the prototype. Different methods were investigated to predict cavitation erosion on Francis turbines from model. They are based on measurement of pitting, pressure fluctuations and acceleration. The methods proposed are suitable to measure cavitation aggressiveness on model and on prototype, and that the level on the model is several orders of magnitude smaller than on the prototype. (author) 18 refs.

  6. Geospatial application of the Water Erosion Prediction Project (WEPP) Model

    Science.gov (United States)

    D. C. Flanagan; J. R. Frankenberger; T. A. Cochrane; C. S. Renschler; W. J. Elliot

    2011-01-01

    The Water Erosion Prediction Project (WEPP) model is a process-based technology for prediction of soil erosion by water at hillslope profile, field, and small watershed scales. In particular, WEPP utilizes observed or generated daily climate inputs to drive the surface hydrology processes (infiltration, runoff, ET) component, which subsequently impacts the rest of the...

  7. The Current State of Predicting Furrow Irrigation Erosion

    Science.gov (United States)

    There continues to be a need to predict furrow irrigation erosion to estimate on- and off-site impacts of irrigation management. The objective of this paper is to review the current state of furrow erosion prediction technology considering four models: SISL, WEPP, WinSRFR and APEX. SISL is an empiri...

  8. The development of U. S. soil erosion prediction and modeling

    Directory of Open Access Journals (Sweden)

    John M. Laflen

    2013-09-01

    Full Text Available Soil erosion prediction technology began over 70 years ago when Austin Zingg published a relationship between soil erosion (by water and land slope and length, followed shortly by a relationship by Dwight Smith that expanded this equation to include conservation practices. But, it was nearly 20 years before this work's expansion resulted in the Universal Soil Loss Equation (USLE, perhaps the foremost achievement in soil erosion prediction in the last century. The USLE has increased in application and complexity, and its usefulness and limitations have led to the development of additional technologies and new science in soil erosion research and prediction. Main among these new technologies is the Water Erosion Prediction Project (WEPP model, which has helped to overcome many of the shortcomings of the USLE, and increased the scale over which erosion by water can be predicted. Areas of application of erosion prediction include almost all land types: urban, rural, cropland, forests, rangeland, and construction sites. Specialty applications of WEPP include prediction of radioactive material movement with soils at a superfund cleanup site, and near real-time daily estimation of soil erosion for the entire state of Iowa.

  9. Understanding and Predicting Gun Barrel Erosion

    National Research Council Canada - National Science Library

    Johnston, Ian A

    2005-01-01

    The Australian Defence Force will soon have to contend with gun barrel erosion issues arising from the use of new low-vulnerability gun propellants, the acquisition of new ammunition and gun systems...

  10. Water erosion risk prediction in eucalyptus plantations

    Directory of Open Access Journals (Sweden)

    Mayesse Aparecida da Silva

    2014-04-01

    Full Text Available Eucalyptus plantations are normally found in vulnerable ecosystems such as steep slope, soil with low natural fertility and lands that were degraded by agriculture. The objective of this study was to obtain Universal Soil Loss Equation (USLE factors and use them to estimate water erosion risk in regions with eucalyptus planted. The USLE factors were obtained in field plots under natural rainfall in the Rio Doce Basin, MG, Brazil, and the model applied to assess erosion risk using USLE in a Geographic Information System. The study area showed rainfall-runoff erosivity values from 10,721 to 10,642 MJ mm ha-1 h-1 yr-1. Some soils (Latosols had very low erodibility values (2.0 x 10-4 and 1.0 x 10-4t h MJ-1 mm-1, the topographic factor ranged from 0.03 to 10.57 and crop and management factor values obtained for native forest, eucalyptus and planted pasture were 0.09, 0.12 and 0.22, respectively. Water erosion risk estimates for current land use indicated that the areas where should receive more attention were mainly areas with greater topographic factors and those with Cambisols. Planning of forestry activities in this region should consider implementation of other conservation practices beyond those already used, reducing areas with a greater risk of soil erosion and increasing areas with very low risk.

  11. Predicting of soil erosion with regarding to rainfall erosivity and soil erodibility

    Science.gov (United States)

    Suif, Zuliziana; Razak, Mohd Amirun Anis Ab; Ahmad, Nordila

    2018-02-01

    The soil along the hill and slope are wearing away due to erosion and it can take place due to occurrence of weak and heavy rainfall. The aim of this study is to predict the soil erosion degree in Universiti Pertahanan Nasional Malaysia (UPNM) area focused on two major factor which is soil erodibility and rainfall erosivity. Soil erodibility is the possibilities of soil to detach and carried away during rainfall and runoff. The "ROM" scale was used in this study to determine the degree of soil erodibility, namely low, moderate, high, and very high. As for rainfall erosivity, the erosive power caused by rainfall that cause soil loss. A daily rainfall data collected from January to April was analyzed by using ROSE index classification to identify the potential risk of soil erosion. The result shows that the soil erodibilty are moderate at MTD`s hill, high at behind of block Lestari and Landslide MTD hill, and critical at behind the mess cadet. While, the highest rainfall erosivity was recorded in March and April. Overall, this study would benefit the organization greatly in saving cost in landslide protection as relevant authorities can take early measures repairing the most affected area of soil erosion.

  12. Patterns of magnetic resonance imaging bone erosion in rheumatoid arthritis--which bones are most frequently involved and show the most change?

    DEFF Research Database (Denmark)

    Ostergaard, Mikkel; Møller Døhn, Uffe; Duer-Jensen, Anne

    2011-01-01

    To investigate by magnetic resonance imaging (MRI) which bones in wrists and metacarpophalangeal (MCP) joints most frequently show bone erosions, and which most frequently demonstrate erosive progression, in early and established rheumatoid arthritis (RA).......To investigate by magnetic resonance imaging (MRI) which bones in wrists and metacarpophalangeal (MCP) joints most frequently show bone erosions, and which most frequently demonstrate erosive progression, in early and established rheumatoid arthritis (RA)....

  13. Theoretical model for cavitation erosion prediction in centrifugal pump impeller

    International Nuclear Information System (INIS)

    Rayan, M.A.; Mahgob, M.M.; Mostafa, N.H.

    1990-01-01

    Cavitation is known to have great effects on pump hydraulic and mechanical characteristics. These effects are mainly described by deviation in pump performance, increasing vibration and noise level as well as erosion of blade and casing materials. In the present work, only the hydrodynamic aspect of cavitation was considered. The efforts were directed toward the study of cavitation inception, cavity mechanics and material erosion in order to clarify the macrohydrodynamic aspects of cavitation erosive wear in real machines. As a result of this study, it was found that cavitation damage can be predicted from model data. The obtained theoretical results show good agreement with the experimental results obtained in this investigation and with results of some other investigations. The application of the findings of this work will help the design engineer in predicting the erosion rate, according to the different operating conditions. (author)

  14. Deep erosions of the palmar aspect of the navicular bone diagnosed by standing magnetic resonance imaging.

    Science.gov (United States)

    Sherlock, C; Mair, T; Blunden, T

    2008-11-01

    Erosion of the palmar (flexor) aspect of the navicular bone is difficult to diagnose with conventional imaging techniques. To review the clinical, magnetic resonance (MR) and pathological features of deep erosions of the palmar aspect of the navicular bone. Cases of deep erosions of the palmar aspect of the navicular bone, diagnosed by standing low field MR imaging, were selected. Clinical details, results of diagnostic procedures, MR features and pathological findings were reviewed. Deep erosions of the palmar aspect of the navicular bone were diagnosed in 16 mature horses, 6 of which were bilaterally lame. Sudden onset of lameness was recorded in 63%. Radiography prior to MR imaging showed equivocal changes in 7 horses. The MR features consisted of focal areas of intermediate or high signal intensity on T1-, T2*- and T2-weighted images and STIR images affecting the dorsal aspect of the deep digital flexor tendon, the fibrocartilage of the palmar aspect, subchondral compact bone and medulla of the navicular bone. On follow-up, 7/16 horses (44%) had been subjected to euthanasia and only one was being worked at its previous level. Erosions of the palmar aspect of the navicular bone were confirmed post mortem in 2 horses. Histologically, the lesions were characterised by localised degeneration of fibrocartilage with underlying focal osteonecrosis and fibroplasia. The adjacent deep digital flexor tendon showed fibril formation and fibrocartilaginous metaplasia. Deep erosions of the palmar aspect of the navicular bone are more easily diagnosed by standing low field MR imaging than by conventional radiography. The lesions involve degeneration of the palmar fibrocartilage with underlying osteonecrosis and fibroplasia affecting the subchondral compact bone and medulla, and carry a poor prognosis for return to performance. Diagnosis of shallow erosive lesions of the palmar fibrocartilage may allow therapeutic intervention earlier in the disease process, thereby preventing

  15. Erosion prediction for alpine slopes: a symbiosis of remote sensing and a physical based erosion model

    Science.gov (United States)

    Kaiser, Andreas; Neugirg, Fabian; Haas, Florian; Schindewolf, Marcus; Schmidt, Jürgen

    2014-05-01

    As rainfall simulations represent an established tool for quantifying soil detachment on cultivated area in lowlands and low mountain ranges, they are rarely used on steep slopes high mountain ranges. Still this terrain represents productive sediment sources of high morphodynamic. A quantitative differentiation between gravitationally and fluvially relocated material reveals a major challenge in understanding erosion on steep slopes: does solifluction as a result of melting in spring or heavy convective rainstorms during summer cause the essential erosion processes? This paper aims to answer this question by separating gravitational mass movement (solifluction, landslides, mudflow and needle ice) and runoff-induced detachment. First simulated rainstorm experiments are used to assess the sediment production on bare soil on a strongly inclined plot (1 m², 42°) in the northern limestone Alps. Throughout precipitation experiments runoff and related suspended sediments were quantified. In order to enlarge slope length virtually to around 20 m a runoff feeding device is additionally implemented. Soil physical parameters were derived from on-site sampling. The generated data is introduced to the physically based and catchment-scaled erosion model EROSION 3D to upscale plot size to small watershed conditions. Thus infiltration, runoff, detachment, transport and finally deposition can be predicted for single rainstorm events and storm sequences. Secondly, in order to separate gravitational mass movements and water erosion, a LiDAR and structure-from-motion based monitoring approach is carried out to produce high-resolution digital elevation models. A time series analysis of detachment and deposition from different points in time is implemented. Absolute volume losses are then compared to sediment losses calculated by the erosion model as the latter only generates data that is connected to water induced hillside erosion. This methodology will be applied in other watersheds

  16. Geospatial application of the Water Erosion Prediction Project (WEPP) model

    Science.gov (United States)

    D. C. Flanagan; J. R. Frankenberger; T. A. Cochrane; C. S. Renschler; W. J. Elliot

    2013-01-01

    At the hillslope profile and/or field scale, a simple Windows graphical user interface (GUI) is available to easily specify the slope, soil, and management inputs for application of the USDA Water Erosion Prediction Project (WEPP) model. Likewise, basic small watershed configurations of a few hillslopes and channels can be created and simulated with this GUI. However,...

  17. Calcifying tendinitis of the rotator cuff with cortical bone erosion

    Energy Technology Data Exchange (ETDEWEB)

    Chan, Roxanne; Kim, David H.; Millett, Peter J. [Harvard Medical School, Brigham and Women' s Hospital, Boston, Massachusetts (United States); Weissman, Barbara N. [Harvard Medical School, Brigham and Women' s Hospital, Boston, Massachusetts (United States); Brigham and Women' s Hospital, Department of Radiology, Musculoskeletal Division, Boston (United States)

    2004-10-01

    Calcifying tendinitis occurs most commonly in the rotator cuff tendons, particularly involving the supraspinatus tendon insertion, and is often asymptomatic. Cortical erosion secondary to calcifying tendinitis has been reported in multiple locations, including in the rotator cuff tendons. We present a pathologically proven case of symptomatic calcifying tendinitis involving the infraspinatus tendon with cortical erosion with correlative radiographic, CT, and MR findings. The importance of considering this diagnosis when evaluating lytic lesions of the humerus and the imaging differential diagnosis of calcifying tendinitis and cortical erosion are discussed. (orig.)

  18. Calcifying tendinitis of the rotator cuff with cortical bone erosion

    International Nuclear Information System (INIS)

    Chan, Roxanne; Kim, David H.; Millett, Peter J.; Weissman, Barbara N.

    2004-01-01

    Calcifying tendinitis occurs most commonly in the rotator cuff tendons, particularly involving the supraspinatus tendon insertion, and is often asymptomatic. Cortical erosion secondary to calcifying tendinitis has been reported in multiple locations, including in the rotator cuff tendons. We present a pathologically proven case of symptomatic calcifying tendinitis involving the infraspinatus tendon with cortical erosion with correlative radiographic, CT, and MR findings. The importance of considering this diagnosis when evaluating lytic lesions of the humerus and the imaging differential diagnosis of calcifying tendinitis and cortical erosion are discussed. (orig.)

  19. A history of wind erosion prediction models in the United States Department of Agriculture: The Wind Erosion Prediction System (WEPS)

    Science.gov (United States)

    Development of the Wind Erosion Prediction System (WEPS) was officially inaugurated in 1985 by United States Department of Agriculture-Agricultural Research Service (USDA-ARS) scientists in response to customer requests, particularly those coming from the USDA Soil Conservation Service (SCS), for im...

  20. Predicting coastal cliff erosion using a Bayesian probabilistic model

    Science.gov (United States)

    Hapke, Cheryl J.; Plant, Nathaniel G.

    2010-01-01

    Regional coastal cliff retreat is difficult to model due to the episodic nature of failures and the along-shore variability of retreat events. There is a growing demand, however, for predictive models that can be used to forecast areas vulnerable to coastal erosion hazards. Increasingly, probabilistic models are being employed that require data sets of high temporal density to define the joint probability density function that relates forcing variables (e.g. wave conditions) and initial conditions (e.g. cliff geometry) to erosion events. In this study we use a multi-parameter Bayesian network to investigate correlations between key variables that control and influence variations in cliff retreat processes. The network uses Bayesian statistical methods to estimate event probabilities using existing observations. Within this framework, we forecast the spatial distribution of cliff retreat along two stretches of cliffed coast in Southern California. The input parameters are the height and slope of the cliff, a descriptor of material strength based on the dominant cliff-forming lithology, and the long-term cliff erosion rate that represents prior behavior. The model is forced using predicted wave impact hours. Results demonstrate that the Bayesian approach is well-suited to the forward modeling of coastal cliff retreat, with the correct outcomes forecast in 70–90% of the modeled transects. The model also performs well in identifying specific locations of high cliff erosion, thus providing a foundation for hazard mapping. This approach can be employed to predict cliff erosion at time-scales ranging from storm events to the impacts of sea-level rise at the century-scale.

  1. Experience in the application of erosion-corrosion prediction programs

    International Nuclear Information System (INIS)

    Castiella Villacampa, E.; Cacho Cordero, L.; Pascual Velazquez, A.; Casar Asuar, M.

    1994-01-01

    Recently the results of the Nuclear Regulatory Commission's follow-on programme relating to the application of erosion-corrosion supervision and control programs were published. The main problems encountered in their practical application are highlighted, namely those associated with prediction, calculation of minimum thickness acceptable by code, results analyses of the thicknesses measured using ultrasound technology, cases of incorrect substitution, etc. A number of power plants in Spain are currently using a computerised prediction and monitoring program for the erosion-corrosion phenomenon. The experience gained in the application of this program has been such that it has led to a number or benefits: an improvement in the application of the program, proof of its suitability to real situation, the establishment of a series of criteria relative to the inclusion or exclusion of consideration during data input, the monitoring of the phenomenon, selection of elements for inspection, etc. The report describes these areas, using typical examples as illustrations. (Author)

  2. Forest soil erosion prediction as influenced by wildfire and roads

    Science.gov (United States)

    Cao, L.; Brooks, E. S.; Elliot, W.

    2017-12-01

    Following a wildfire, the risk of erosion is greatly increased. Forest road networks may change the underlying topography and alter natural flow paths. Flow accumulation and energy can be redistributed by roads and alter soil erosion processes. A LiDAR (Light Detection and Ranging) DEM makes it possible to quantify road topography, and estimate how roads influence surface runoff and sediment transport in a fire-disturbed watershed. With GIS technology and a soil erosion model, this study was carried out to evaluate the effect of roads on erosion and sediment yield following the Emerald Fire southwest of Lake Tahoe. The GeoWEPP model was used to estimate onsite erosion and offsite sediment delivery from each hillslope polygon and channel segment before and after fire disturbance in part of the burned area. The GeoWEPP flow path method was used to estimate the post-fire erosion rate of each GIS pixel. A 2-m resolution LiDAR DEM was used as the terrain layer. The Emerald Fire greatly increased onsite soil loss and sediment yields within the fire boundary. Following the fire, 78.71% of the burned area had predicted sediment yields greater than 4 Mg/ha/yr, compared to the preburn condition when 65.3% of the study area was estimated to generate a sediment yield less than 0.25 Mg/ha/yr. Roads had a remarkable influence on the flow path simulation and sub-catchments delineation, affecting sediment transport process spatially. Road segments acted as barriers that intercepted overland runoff and reduced downslope flow energy accumulation, therefore reducing onsite soil loss downslope of the road. Roads also changed the boundary of sub-catchment and defined new hydrological units. Road segments can transport sediment from one sub-catchment to another. This in turn leads to the redistribution of sediment and alters sediment yield for some sub-catchments. Culverts and road drain systems are of vital importance in rerouting runoff and sediment. Conservation structures can be

  3. Detection of rheumatoid arthritis bone erosions by two different dedicated extremity MRI units and conventional radiography

    DEFF Research Database (Denmark)

    Duer-Jensen, A.; Vestergaard, A.; Dohn, U.M.

    2008-01-01

    Objectives: To compare the ability of two different dedicated extremity MRI (E-MRI) units and conventional radiography (CR) for identifying bone erosions in rheumatoid arthritis (RA) metacarpophalangeal (MCP) and wrist joints. Methods: CR and two MRI examinations (using 0.2 T Esaote Artoscan and 0...

  4. Detection of rheumatoid arthritis bone erosions by 2 different dedicated extremity MRI units and conventional radiography

    DEFF Research Database (Denmark)

    Duer, Anne; Vestergaard, Aage; Døhn, Uffe Møller

    2008-01-01

    OBJECTIVES: To compare the ability of 2 different dedicated extremity magnetic resonance imaging (E-MRI) units and conventional radiography (CR) for identifying bone erosions in rheumatoid arthritis (RA) metacarpophalangeal (MCP) and wrist joints. METHODS: CR and 2 MRI-examinations (on 0.2T Esaote...

  5. Use of Tomosynthesis for Detection of Bone Erosions of the Foot in Patients With Established Rheumatoid Arthritis: Comparison With Radiography and CT.

    Science.gov (United States)

    Simoni, Paolo; Gérard, Laurent; Kaiser, Marie-Joëlle; Ribbens, Clio; Rinkin, Charline; Malaise, Olivier; Malaise, Michel

    2015-08-01

    The purpose of this study was to compare tomosynthesis with radiography for the detection of bone erosions of the foot in patients with established rheumatoid arthritis (RA) using MDCT as a reference standard. Eighteen consecutive patients with established RA were included. Each patient underwent radiography, tomosynthesis, and CT examinations of the feet on the same day. Two radiologists independently determined the number of bone erosions and the Sharp-van der Heijde score with each of the three imaging modalities. On a total of 216 joints from 18 patients, 216 bone erosions were detected on CT, 215 on tomosynthesis, and 181 with radiography. The mean (± SD) Sharp-van der Heijde score was equivalent for tomosynthesis (18.8 ± 16.8) and CT (19.8 ± 18.5) but was statistically lower for radiography (16.4 ± 18.0) (p = 0.030). The respective overall sensitivity, specificity, accuracy, positive predictive value, and negative predictive value for tomosynthesis were 80%, 75%, 78%, 76%, and 80%, whereas the respective corresponding values for radiography were 66%, 81%, 74%, 77%, and 71%. The radiation burden of tomosynthesis was almost equivalent to that of radiography. Tomosynthesis has a higher sensitivity than radiography to detect bone erosions of the foot in patients with established RA and imparts an almost equivalent radiation burden.

  6. Summary Findings of a Systematic Literature Review of the Ultrasound Assessment of Bone Erosions in Rheumatoid Arthritis

    DEFF Research Database (Denmark)

    Szkudlarek, Marcin; Terslev, Lene; Wakefield, Richard J

    2016-01-01

    OBJECTIVE: Bone erosions in rheumatoid arthritis (RA) have been studied in an increasing amount of research. Both earlier and present classification criteria of RA contain erosions as a significant classification component. Ultrasound (US) can detect bone changes in accessible surfaces. Therefore...... (5 papers). Reliability of assessment was presented in 20 papers and sensitivity to change in 11 papers. CONCLUSION: This paper presents results of a systematic literature review of bone erosion assessment in RA with US. The survey suggests that US can be a helpful adjunct to the existing methods...... of imaging bone erosions in RA. It analyzes definitions, scoring systems, used comparators, and elements of the OMERACT filter. It also presents recommendations for a future research agenda based on the results of the review....

  7. Long-term predictive capability of erosion models

    Science.gov (United States)

    Veerabhadra, P.; Buckley, D. H.

    1983-01-01

    A brief overview of long-term cavitation and liquid impingement erosion and modeling methods proposed by different investigators, including the curve-fit approach is presented. A table was prepared to highlight the number of variables necessary for each model in order to compute the erosion-versus-time curves. A power law relation based on the average erosion rate is suggested which may solve several modeling problems.

  8. Assessing and Predicting Erosion from Off Highway Vehicle Trails in Front-Range Rocky Mountain Watersheds.

    Science.gov (United States)

    Howard, M. J.; Silins, U.; Anderson, A.

    2016-12-01

    Off highway vehicle (OHV) trails have the potential to deliver sediment to sensitive headwater streams and increased OHV use is a growing watershed management concern in many Rocky Mountain regions. Predictive tools for estimating erosion and sediment inputs are needed to support assessment and management of erosion from OHV trail networks. The objective of this study was to a) assess erodibility (K factor) and total erosion from OHV trail networks in Rocky Mountain watersheds in south-west Alberta, Canada, and to b) evaluate the applicability of the Universal Soil Loss Equation (USLE) for predicting OHV trail erosion to support erosion management strategies. Measured erosion rates and erodibility (K) from rainfall simulation plots on OHV trails during the summers of 2014 and 2015 were compared to USLE predicted erosion from these same trails. Measured erodibility (K) from 23 rainfall simulation plots was highly variable (0.001-0.273 Mg*ha*hr/ha*MJ*mm) as was total seasonal erosion from 52 large trail sections (0.0595-43.3 Mg/ha) across trail segments of variable slope, stoniness, and trail use intensity. In particular, intensity of trail use had a large effect on both erodibility and total erosion that is not presently captured by erodibility indices (K) derived from soil characteristics. Results of this study suggest that while application of USLE for predicting erosion from OHV trail networks may be useful for initial coarse erosion assessment, a better understanding of the effect of factors such as road/trail use intensity on erodibility is needed to support use of USLE or associated erosion prediction tools for road/trail erosion management.

  9. Prediction of Soil Erosion Rates in Japan where Heavily Forested Landscape with Unstable Terrain

    Science.gov (United States)

    Nanko, K.; Oguro, M.; Miura, S.; Masaki, T.

    2016-12-01

    Soil is fundamental for plant growth, water conservation, and sustainable forest management. Multidisciplinary interest in the role of the soil in areas such as biodiversity, ecosystem services, land degradation, and water security has been growing (Miura et al., 2015). Forest is usually protective land use from soil erosion because vegetation buffers rainfall power and erosivity. However, some types of forest in Japan show high susceptibility to soil erosion due to little ground cover and steep slopes exceeding thirty degree, especially young Japanese cypress (Chamaecyparis obtusa) plantations (Miura et al., 2002). This is a critical issue for sustainable forest management because C. obtusaplantations account for 10% of the total forest coverage in Japan (Forestry Agency, 2009). Prediction of soil erosion rates on nationwide scale is necessary to make decision for future forest management plan. To predict and map soil erosion rates across Japan, we applied three soil erosion models, RUSLE (Revised Universal Soil Loss Equation, Wischmeier and Smith, 1978), PESERA (Pan-European Soil Erosion Risk Assessment, Kirkby et al., 2003), and RMMF (Revised Morgan-Morgan-Finney, Morgan, 2001). The grid scale is 1-km. RUSLE and PESERA are most widely used erosion models today. RMMF includes interactions between rainfall and vegetation, such as canopy interception and ratio of canopy drainage in throughfall. Evaporated rainwater by canopy interception, generally accounts for 15-20% in annual rainfall, does not contribute soil erosion. Whereas, larger raindrops generated by canopy drainage produced higher splash erosion rates than gross rainfall (Nanko et al., 2008). Therefore, rainfall redistribution process in canopy should be considered to predict soil erosion rates in forested landscape. We compared the results from three erosion models and analyze the importance of environmental factors for the prediction of soil erosion rates. This research was supported by the Environment

  10. Challenges in soil erosion research and prediction model development

    Science.gov (United States)

    Quantification of soil erosion has been traditionally considered as a surface hydrologic process with equations for soil detachment and sediment transport derived from the mechanics and hydraulics of the rainfall and surface flow. Under the current erosion modeling framework, the soil has a constant...

  11. Advanced experimental and numerical techniques for cavitation erosion prediction

    CERN Document Server

    Chahine, Georges; Franc, Jean-Pierre; Karimi, Ayat

    2014-01-01

    This book provides a comprehensive treatment of the cavitation erosion phenomenon and state-of-the-art research in the field. It is divided into two parts. Part 1 consists of seven chapters, offering a wide range of computational and experimental approaches to cavitation erosion. It includes a general introduction to cavitation and cavitation erosion, a detailed description of facilities and measurement techniques commonly used in cavitation erosion studies, an extensive presentation of various stages of cavitation damage (including incubation and mass loss), and insights into the contribution of computational methods to the analysis of both fluid and material behavior. The proposed approach is based on a detailed description of impact loads generated by collapsing cavitation bubbles and a physical analysis of the material response to these loads. Part 2 is devoted to a selection of nine papers presented at the International Workshop on Advanced Experimental and Numerical Techniques for Cavitation Erosion (Gr...

  12. Detection of bone erosions in rheumatoid arthritis wrist joints with magnetic resonance imaging, computed tomography and radiography

    DEFF Research Database (Denmark)

    Døhn, Uffe Møller; Ejbjerg, Bo J; Hasselquist, Maria

    2008-01-01

    , specificity and accuracy (concordance) of MRI for detecting erosions were 61%, 93% and 77%, respectively, while the respective values were 24%, 99% and 63% for radiography. The intramodality agreements when measuring erosion volumes were high for both CT and MRI (Spearman correlation coefficients 0.92 and 0...... sensitivity and good specificity and accuracy for detection of erosions in rheumatoid arthritis and healthy wrist bones, while radiography showed very low sensitivity. The tested volumetric method was highly reproducible and correlated to scores of erosions....... measuring volumes of erosions on CT and MRI is reproducible and correlated to semiquantitative assessments (scores) of erosions on CT, MRI and radiography. METHODS: Seventeen patients with rheumatoid arthritis and four healthy control individuals underwent CT, MRI and radiography of one wrist, performed...

  13. Bone erosion and subacromial bursitis caused by diphtheria-tetanus-poliomyelitis vaccine.

    Science.gov (United States)

    Salmon, J H; Geoffroy, M; Eschard, J P; Ohl, X

    2015-11-17

    Revaxis(®) is a vaccine against diphtheria, tetanus and poliomyelitis (dT-IPV). This vaccine should not be administered by the intradermal or intravenous route. Poor injection techniques and related consequences are rare. We report a case of bursitis associated with reactive glenohumeral effusion complicated by bone erosion occurring after injection of the dT-IPV vaccine. A 26 year old patient was admitted for painful left shoulder causing functional impairment. Control magnetic resonance imaging showed bone oedema on the upper outer part of the humeral head, with a slight cortical irregularity, indicating that the vaccine was injected in contact with the bone at this location, causing erosion. Outcome was favourable after intra-articular corticosteroids. Reports of articular or periarticular injury after vaccination are extremely rare, in view of the substantial number of vaccines administered every year. The potential complications of vaccination are well known to general practitioners but under-reported in the literature. Copyright © 2015 Elsevier Ltd. All rights reserved.

  14. Predicting the temporal relationship between soil cesium-137 and erosion rate

    International Nuclear Information System (INIS)

    Kachanoski, R.G.; De Jong, E.

    1984-01-01

    A model was developed that predicts the amount of 137 Cs remaining in soil as a function of time and erosion rate. The model accounts for atmospheric deposition, radioactive decay, tillage dilution, and erosion transport of 137 Cs, as well as seasonal differences in 137 Cs deposition and erosion rates. The model was used to estimate minimum resolution of erosion estimates based on detection limits and accuracy of 137 Cs measurement by gamma spectroscopy, as a function of time and erosion rate. The analysis showed that under Saskatchewan conditions, changes in 137 Cs at a given site can be used to estimate erosion rates between 0.5 and 10 kg m -2 yr -1 with reasonable precision, provided the sampling interval is at least 15 yr. The relationship of fraction of 137 Cs lost vs. erosion as predicted by the model was compared with other methods being used. The model was used to estimate erosion from selected Saskatchewan soils where 137 Cs levels were measured in 1966 and again in 1981. Erosion rates calculated with the model varied from 1 kg m -2 yr -1 for a sandy loam soil in continuous forage to 19 kg m -2 yr -1 for a similar soil in a crop-fallow rotation. Erosion estimates using the model were higher than those calculated by assuming that soil loss was directly proportional to 137 Cs loss, especially when 137 Cs loss was high

  15. Phalangeal bone mineral density predicts incident fractures

    DEFF Research Database (Denmark)

    Friis-Holmberg, Teresa; Brixen, Kim; Rubin, Katrine Hass

    2012-01-01

    This prospective study investigates the use of phalangeal bone mineral density (BMD) in predicting fractures in a cohort (15,542) who underwent a BMD scan. In both women and men, a decrease in BMD was associated with an increased risk of fracture when adjusted for age and prevalent fractures...

  16. The effects of bone erosion from aortic aneurysm on the regional uptake of FDG

    DEFF Research Database (Denmark)

    Louring-Andersen, J.; Law, I.

    2008-01-01

    aorta just below the carina. An abnormal crescent-shaped uptake was identified at the margin between the aneurysm and the adjacent thoracic vertebral bodies. At this site a correspondingly shaped bone erosion on CT was proof of the chronic effects of the aneurysm. There were no signs of regional......A 71-year-old white man with a known right-sided apical nonsmall cell lung carcinoma was referred for a F-18 FDG whole body PET-CT examination after chemotherapy before radiotherapy. A staging CT scan had revealed an asymptomatic fusiform 65 mm in diameter nondissecting aneurysm of the thoracic...

  17. Predicting soil erosion risk at the Alqueva dam watershed

    OpenAIRE

    Ferreira, Vera; Panagopoulos, Thomas

    2012-01-01

    Soil erosion is serious economic and environmental concern. Assessing soil erosion risk in the Alqueva dam watershed is urgently needed to conserve soil and water resources and prevent the accelerated dam siltation, taking into account the possible land-use changes, due to tourism development, intensification of irrigated farming and biomass production, as well as climate change. A comprehensive methodology that integrates Revised Universal Soil Loss Equation (RUSLE) model and Geographic Info...

  18. Building Chinese wind data for Wind Erosion Prediction System using surrogate US data

    Science.gov (United States)

    Wind erosion is a global problem, especially in arid and semiarid regions of the world, which leads to land degradation and atmosphere pollution. The process-based Wind Erosion Prediction System (WEPS), developed by the USDA, is capable of simulating the windblown soil loss with changing weather and...

  19. Adapting the Water Erosion Prediction Project (WEPP) model for forest applications

    Science.gov (United States)

    Shuhui Dun; Joan Q. Wu; William J. Elliot; Peter R. Robichaud; Dennis C. Flanagan; James R. Frankenberger; Robert E. Brown; Arthur C. Xu

    2009-01-01

    There has been an increasing public concern over forest stream pollution by excessive sedimentation due to natural or human disturbances. Adequate erosion simulation tools are needed for sound management of forest resources. The Water Erosion Prediction Project (WEPP) watershed model has proved useful in forest applications where Hortonian flow is the major form of...

  20. The Rangeland Hydrology and Erosion Model: A dynamic approach for predicting soil loss on rangelands

    Science.gov (United States)

    In this study we present the improved Rangeland Hydrology and Erosion Model (RHEM V2.3), a process-based erosion prediction tool specific for rangeland application. The article provides the mathematical formulation of the model and parameter estimation equations. Model performance is assessed agains...

  1. The role of bathymetry, wave obliquity and coastal curvature in dune erosion prediction

    NARCIS (Netherlands)

    Den Heijer, C.

    2013-01-01

    This study aims at reducing uncertainty in dune erosion predictions, in particular at complex dune coasts, in order to improve the assessment method for dune safety against flooding. To that end, state-of-the-art process-based dune erosion models are employed to further investigate issues

  2. Comparison of WEPP and APEX runoff and erosion prediction at field scale in Goodwater Creek Experimental Watershed

    Science.gov (United States)

    The Water Erosion Prediction Project (WEPP) and the Agricultural Policy/Environmental eXtender (APEX) are process-based models that can predict spatial and temporal distributions of erosion for hillslopes and watersheds. This study applies the WEPP model to predict runoff and erosion for a 35-ha fie...

  3. Erosion Prediction Analysis and Landuse Planning in Gunggung Watershed, Bali, Indonesia

    Science.gov (United States)

    Trigunasih, N. M.; Kusmawati, T.; Yuli Lestari, N. W.

    2018-02-01

    The purpose of this research is to predict the erosion that occurs in Gunggung watershed and sustainable landuse management plan. This research used the USLE (Universal Soil Loss Equation) methodology. The method used observation / field survey and soil analysis at the Soil Laboratory of Faculty of Agriculture, Udayana University. This research is divided into 5 stages, (1) land unit determination, (2) Field observation and soil sampling, (3) Laboratory analysis and data collection, (4) Prediction of erosion using USLE (Universal Soil Loss Equation) method, (5) The permissible erosion determination (EDP) then (6) determines the level of erosion hazard based on the depth of the soil, as well as the soil conservation plan if the erosion is greater than the allowed erosion, and (7) determining landuse management plan for sustainable agriculture. Erosion which value is smaller than soil loss tolerance can be exploited in a sustainable manner, while erosion exceeds allowable erosion will be conservation measures. Conservation action is the improvement of vegetation and land management. Land management like improvements the terrace, addition of organic matter, increase plant density, planting ground cover and planting layered header system will increase the land capability classes. Land use recommended after management is mixed plantation high density with forest plants, mix plantation high density with patio bench construction, seasonal cultivation and perennial crops, cultivation of perennial crops and cultivation of seasonal crops.

  4. Early Subchondral Bone Loss at Arthritis Onset Predicted Late Arthritis Severity in a Rat Arthritis Model.

    Science.gov (United States)

    Courbon, Guillaume; Cleret, Damien; Linossier, Marie-Thérèse; Vico, Laurence; Marotte, Hubert

    2017-06-01

    Synovitis is usually observed before loss of articular function in rheumatoid arthritis (RA). In addition to the synovium and according to the "Inside-Outside" theory, bone compartment is also involved in RA pathogenesis. Then, we investigated time dependent articular bone loss and prediction of early bone loss to late arthritis severity on the rat adjuvant-induced arthritis (AIA) model. Lewis female rats were longitudinally monitored from arthritis induction (day 0), with early (day 10) and late (day 17) steps. Trabecular and cortical microarchitecture parameters of four ankle bones were assessed by microcomputed tomography. Gene expression was determined at sacrifice. Arthritis occurred at day 10 in AIA rats. At this time, bone erosions were detected on four ankle bones, with cortical porosity increase (+67%) and trabecular alterations including bone volume fraction (BV/TV: -13%), and trabecular thickness decrease. Navicular bone assessment was the most reproducible and sensitive. Furthermore, strong correlations were observed between bone alterations at day 10 and arthritis severity or bone loss at day 17, including predictability of day 10 BV/TV to day 17 articular index (R 2  = 0.76). Finally, gene expression at day 17 confirmed massive osteoclast activation and interestingly provided insights on strong activation of bone formation inhibitor markers at the joint level. In rat AIA, bone loss was already observed at synovitis onset and was predicted late arthritis severity. Our results reinforced the key role of subchondral bone in arthritis pathogenesis, in favour to the "Inside-Outside" theory. Mechanisms of bone loss in rat AIA involved resorption activation and formation inhibition changes. J. Cell. Physiol. 232: 1318-1325, 2017. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  5. A history of wind erosion prediction models in the United States Department of Agriculture prior to the Wind Erosion Prediction System

    Science.gov (United States)

    Tatarko, John; Sporcic, Michael A.; Skidmore, Edward L.

    2013-09-01

    The Great Plains experienced an influx of settlers in the late 1850s-1900. Periodic drought was hard on both settlers and the soil and caused severe wind erosion. The period known as the Dirty Thirties, 1931-1939, produced many severe windstorms, and the resulting dusty sky over Washington, DC helped Hugh Hammond Bennett gain political support for the Soil Conservation Act of 1937 that started the USDA Soil Conservation Service (SCS). Austin W. Zingg and William S. Chepil began wind erosion studies at a USDA laboratory at Kansas State University in 1947. Neil P. Woodruff and Francis H. Siddoway published the first widely used model for wind erosion in 1965, called the Wind Erosion Equation (WEQ). The WEQ was solved using a series of charts and lookup tables. Subsequent improvements to WEQ included monthly magnitudes of the total wind, a computer version of WEQ programmed in FORTRAN, small-grain equivalents for range grasses, tillage systems, effects of residue management, crop row direction, cloddiness, monthly climate factors, and the weather. The SCS and the Natural Resources Conservation Service (NRCS) produced several computer versions of WEQ with the goal of standardizing and simplifying it for field personnel including a standalone version of WEQ was developed in the late 1990s using Microsoft Excel. Although WEQ was a great advancement to the science of prediction and control of wind erosion on cropland, it had many limitations that prevented its use on many lands throughout the United States and the world. In response to these limitations, the USDA developed a process-based model know as the Wind Erosion Prediction System (WEPS). The USDA Agricultural Research Service has taken the lead in developing science and technology for wind erosion prediction.

  6. Prediction method for cavitation erosion based on measurement of bubble collapse impact loads

    International Nuclear Information System (INIS)

    Hattori, S; Hirose, T; Sugiyama, K

    2009-01-01

    The prediction of cavitation erosion rates is important in order to evaluate the exact life of components. The measurement of impact loads in bubble collapses helps to predict the life under cavitation erosion. In this study, we carried out erosion tests and the measurements of impact loads in bubble collapses with a vibratory apparatus. We evaluated the incubation period based on a cumulative damage rule by measuring the impact loads of cavitation acting on the specimen surface and by using the 'constant impact load - number of impact loads curve' similar to the modified Miner's rule which is employed for fatigue life prediction. We found that the parameter Σ(F i α xn i ) (F i : impact load, n i : number of impacts and α: constant) is suitable for the evaluation of the erosion life. Moreover, we propose a new method that can predict the incubation period under various cavitation conditions.

  7. Comparison of 137Cs fallout redistribution analysis and conventional erosion-prediction models (WEPP, USLE)

    International Nuclear Information System (INIS)

    Sparovek, G.; Bacchi, O.O.S.; Ranieri, S.B.L.; Schnug, E.; De-Maria, I.C.

    2002-01-01

    Soil erosion is the most important component of the degradation of tropical agroecosystems. The rates of erosion should be considered in land evaluation and conservation planning assessment. The methods available for erosion prediction are not sufficiently well calibrated or validated for tropical soils, climates and crops. Thus, differences in estimated soil-erosion values may be expected, even if considering a single set of input data. Three methods for the estimation of soil erosion (USLE, WEPP, and 137 Cs) were applied to a watershed cultivated with sugarcane in southeastern Brazil. The absolute erosion-rate values and differences in the spatial distribution were evaluated. The overall results suggest important differences in the estimates obtained by the three methods. The differences occurred both in mean values and in geographic locations. The relative mean values for soil loss were USLE>> 137 Cs>WEPP and for standard deviations were USLE>WEPP> 137 Cs, indicating that USLE predicted the highest erosion values spread out over the widest range. The poor geographical coincidence of the results is evidence that values resulting from non-calibrated erosion methods should be considered only as qualitative indications. The method selection should consider overall site variability in relation to factors to which the methods are known to be sensitive. (author)

  8. Atomic Oxygen Erosion Yield Prediction for Spacecraft Polymers in Low Earth Orbit

    Science.gov (United States)

    Banks, Bruce A.; Backus, Jane A.; Manno, Michael V.; Waters, Deborah L.; Cameron, Kevin C.; deGroh, Kim K.

    2009-01-01

    The ability to predict the atomic oxygen erosion yield of polymers based on their chemistry and physical properties has been only partially successful because of a lack of reliable low Earth orbit (LEO) erosion yield data. Unfortunately, many of the early experiments did not utilize dehydrated mass loss measurements for erosion yield determination, and the resulting mass loss due to atomic oxygen exposure may have been compromised because samples were often not in consistent states of dehydration during the pre-flight and post-flight mass measurements. This is a particular problem for short duration mission exposures or low erosion yield materials. However, as a result of the retrieval of the Polymer Erosion and Contamination Experiment (PEACE) flown as part of the Materials International Space Station Experiment 2 (MISSE 2), the erosion yields of 38 polymers and pyrolytic graphite were accurately measured. The experiment was exposed to the LEO environment for 3.95 years from August 16, 2001 to July 30, 2005 and was successfully retrieved during a space walk on July 30, 2005 during Discovery s STS-114 Return to Flight mission. The 40 different materials tested (including Kapton H fluence witness samples) were selected specifically to represent a variety of polymers used in space as well as a wide variety of polymer chemical structures. The MISSE 2 PEACE Polymers experiment used carefully dehydrated mass measurements, as well as accurate density measurements to obtain accurate erosion yield data for high-fluence (8.43 1021 atoms/sq cm). The resulting data was used to develop an erosion yield predictive tool with a correlation coefficient of 0.895 and uncertainty of +/-6.3 10(exp -25)cu cm/atom. The predictive tool utilizes the chemical structures and physical properties of polymers to predict in-space atomic oxygen erosion yields. A predictive tool concept (September 2009 version) is presented which represents an improvement over an earlier (December 2008) version.

  9. Association of bone edema with the progression of bone erosions quantified by hand magnetic resonance imaging in patients with rheumatoid arthritis in remission.

    Science.gov (United States)

    Lisbona, Maria Pilar; Pàmies, Anna; Ares, Jesús; Almirall, Miriam; Navallas, Maria; Solano, Albert; Maymó, Joan

    2014-08-01

    To evaluate the association of synovitis, bone marrow edema (BME), and tenosynovitis in the progression of erosions quantified by hand magnetic resonance imaging (MRI) at 1 year in patients with early rheumatoid arthritis (RA) in remission. A total of 56 of 196 patients with early RA in remission at 1 year and with available MRI data at baseline and at 12 months were included. MRI images were assessed according to the Rheumatoid Arthritis Magnetic Resonance Imaging Scoring (RAMRIS) system. Persistent remission was defined as 28-joint Disease Activity Score-erythrocyte sedimentation rate ≤ 2.6 and/or Simplified Disease Activity Index ≤ 3.3 and/or the new boolean American College of Rheumatology/European League Against Rheumatism remission criteria for a continuous period of at least 6 months. Progression of bone erosions was defined as an increase of 1 or more units in annual RAMRIS score for erosions compared to baseline. At 1 year, the majority of patients with RA in sustained remission showed some inflammatory activity on MRI (94.6% synovitis, 46.4% BME, and 58.9% tenosynovitis) and 19 of the 56 patients (33.9%) showed MRI progression of bone erosions. A significant difference was observed in MRI BME at 1 year, with higher mean score in patients with progression compared to nonprogression of erosions (4.8 ± 5.6 and 1.4 ± 2.6, p = 0.03). Subclinical inflammation was identified by MRI in 96.4% of patients with RA in sustained clinical remission. Significantly higher scores of BME after sustained remission were observed in patients with progression of erosions compared to patients with no progression. The persistence of higher scores of BME may explain the progression of bone erosions in patients with persistent clinical remission.

  10. Atomic Oxygen Erosion Yield Predictive Tool for Spacecraft Polymers in Low Earth Orbit

    Science.gov (United States)

    Bank, Bruce A.; de Groh, Kim K.; Backus, Jane A.

    2008-01-01

    A predictive tool was developed to estimate the low Earth orbit (LEO) atomic oxygen erosion yield of polymers based on the results of the Polymer Erosion and Contamination Experiment (PEACE) Polymers experiment flown as part of the Materials International Space Station Experiment 2 (MISSE 2). The MISSE 2 PEACE experiment accurately measured the erosion yield of a wide variety of polymers and pyrolytic graphite. The 40 different materials tested were selected specifically to represent a variety of polymers used in space as well as a wide variety of polymer chemical structures. The resulting erosion yield data was used to develop a predictive tool which utilizes chemical structure and physical properties of polymers that can be measured in ground laboratory testing to predict the in-space atomic oxygen erosion yield of a polymer. The properties include chemical structure, bonding information, density and ash content. The resulting predictive tool has a correlation coefficient of 0.914 when compared with actual MISSE 2 space data for 38 polymers and pyrolytic graphite. The intent of the predictive tool is to be able to make estimates of atomic oxygen erosion yields for new polymers without requiring expensive and time consumptive in-space testing.

  11. Development and Life Prediction of Erosion Resistant Turbine Low Conductivity Thermal Barrier Coatings

    Science.gov (United States)

    Zhu, Dongming; Miller, Robert A.; Kuczmarski, Maria A.

    2010-01-01

    Future rotorcraft propulsion systems are required to operate under highly-loaded conditions and in harsh sand erosion environments, thereby imposing significant material design and durability issues. The incorporation of advanced thermal barrier coatings (TBC) in high pressure turbine systems enables engine designs with higher inlet temperatures, thus improving the engine efficiency, power density and reliability. The impact and erosion resistance of turbine thermal barrier coating systems are crucial to the turbine coating technology application, because a robust turbine blade TBC system is a prerequisite for fully utilizing the potential coating technology benefit in the rotorcraft propulsion. This paper describes the turbine blade TBC development in addressing the coating impact and erosion resistance. Advanced thermal barrier coating systems with improved performance have also been validated in laboratory simulated engine erosion and/or thermal gradient environments. A preliminary life prediction modeling approach to emphasize the turbine blade coating erosion is also presented.

  12. Predicted erosion and sediment delivery of fallout plutonium

    International Nuclear Information System (INIS)

    Foster, G.R.; Hakonson, T.E.

    1984-01-01

    Plutonium (Pu) from fallout after atmospheric explosion of nuclear weapons in the 1950s and 1960s is being redistributed over the landscape by soil erosion and carried on sediment by streams to oceans. Erosion rates computed with the Universal Soil Loss Equation for about 200,000 sample points on nonfederal land across the US were used to estimate Pu removal rates by soil erosion by water, Pu delivery in several major rivers, and concentration of Pu on the transported sediment. Estimates of average annual Pu delivery on sediment ranged from 0.002% of the initial fallout Pu inventory for the Savannah River basin to 0.08% for the Mississippi River basin. If the deposition of Pu had been uniformly 37 Bq/m 2 , the estimated Pu activity on suspended sediment ranged from about 0.26 Bq/kg of sediment for the Savannah River basin to 0.52 Bq/kg for the Columbia and Rio Grande river basins. After 1000 yr, about 9 to 48% of the initial Pu inventory will remain in US soils that are eroding. Much of the Pu on eroded sediment will travel only a short distance from its origin before its host sediment particles are deposited and permanently located, at least for a few hundred years. As much as 90% of the initially deposited Pu will remain, redistributed over the landscape by erosion and deposition. Although the delivery rate of Pu by rivers will not decrease greatly in the next 100 yr, a significant decrease will likely occur by 1000 yr

  13. Prediction of long-term erosion from landfill covers in the southwest

    International Nuclear Information System (INIS)

    Anderson, C.E.; Stormont, J.C.

    1997-01-01

    Erosion is a primary stressor of landfill covers, especially for climates with high intensity storms and low native plant density. Rills and gullies formed by discrete events can damage barrier layers and induce failure. Geomorphologic, empirical and physical modeling procedures are available to provide estimates of surface erosion, but numerical modeling requires accurate representation of the severe rainfall events that generate erosion. The National Weather Service precipitation frequency data and estimates of 5, 10, 15, 30 and 60-minute intensity can be statistically combined in a numerical model to obtain long-term erosion estimates. Physically based numerical models using the KINEROS and AHYMO programs have been utilized to predict the erosion from a southwestern landfill or waste containment site with 0.03, 0.05 and 0.08 meter per meter surface slopes. Results of AHYMO modeling were within 15 percent of average annual values computed with the empirical Universal Soil Loss Equation. However, the estimation of rill and gully formation that primarily degrades cover systems requires quantifying single events. For Southwestern conditions, a single 10-year storm can produce erosion quantifies equal to three times the average annual erosion and a 100-year storm can produce five times the average annual erosion

  14. Numerical Investigation of Temperature Distribution in an Eroded Bend Pipe and Prediction of Erosion Reduced Thickness

    Science.gov (United States)

    Zhu, Hongjun; Feng, Guang; Wang, Qijun

    2014-01-01

    Accurate prediction of erosion thickness is essential for pipe engineering. The objective of the present paper is to study the temperature distribution in an eroded bend pipe and find a new method to predict the erosion reduced thickness. Computational fluid dynamic (CFD) simulations with FLUENT software are carried out to investigate the temperature field. And effects of oil inlet rate, oil inlet temperature, and erosion reduced thickness are examined. The presence of erosion pit brings about the obvious fluctuation of temperature drop along the extrados of bend. And the minimum temperature drop presents at the most severe erosion point. Small inlet temperature or large inlet velocity can lead to small temperature drop, while shallow erosion pit causes great temperature drop. The dimensionless minimum temperature drop is analyzed and the fitting formula is obtained. Using the formula we can calculate the erosion reduced thickness, which is only needed to monitor the outer surface temperature of bend pipe. This new method can provide useful guidance for pipeline monitoring and replacement. PMID:24719576

  15. Chapter 4. Predicting post-fire erosion and sedimentation risk on a landscape scale

    Science.gov (United States)

    MacDonald, L.H.; Sampson, R.; Brady, D.; Juarros, L.; Martin, Deborah

    2000-01-01

    Historic fire suppression efforts have increased the likelihood of large wildfires in much of the western U.S. Post-fire soil erosion and sedimentation risks are important concerns to resource managers. In this paper we develop and apply procedures to predict post-fire erosion and sedimentation risks on a pixel-, catchment-, and landscape-scale in central and western Colorado.Our model for predicting post-fire surface erosion risk is conceptually similar to the Revised Universal Soil Loss Equation (RUSLE). One key addition is the incorporation of a hydrophobicity risk index (HY-RISK) based on vegetation type, predicted fire severity, and soil texture. Post-fire surface erosion risk was assessed for each 90-m pixel by combining HYRISK, slope, soil erodibility, and a factor representing the likely increase in soil wetness due to removal of the vegetation. Sedimentation risk was a simple function of stream gradient. Composite surface erosion and sedimentation risk indices were calculated and compared across the 72 catchments in the study area.When evaluated on a catchment scale, two-thirds of the catchments had relatively little post-fire erosion risk. Steeper catchments with higher fuel loadings typically had the highest post-fire surface erosion risk. These were generally located along the major north-south mountain chains and, to a lesser extent, in west-central Colorado. Sedimentation risks were usually highest in the eastern part of the study area where a higher proportion of streams had lower gradients. While data to validate the predicted erosion and sedimentation risks are lacking, the results appear reasonable and are consistent with our limited field observations. The models and analytic procedures can be readily adapted to other locations and should provide useful tools for planning and management at both the catchment and landscape scale.

  16. Cartilage damage and bone erosion are more prominent determinants of functional impairment in longstanding experimental arthritis than synovial inflammation

    Directory of Open Access Journals (Sweden)

    Silvia Hayer

    2016-11-01

    Full Text Available Chronic inflammation of articular joints causing bone and cartilage destruction consequently leads to functional impairment or loss of mobility in affected joints from individuals affected by rheumatoid arthritis (RA. Even successful treatment with complete resolution of synovial inflammatory processes does not lead to full reversal of joint functionality, pointing to the crucial contribution of irreversibly damaged structural components, such as bone and cartilage, to restricted joint mobility. In this context, we investigated the impact of the distinct components, including synovial inflammation, bone erosion or cartilage damage, as well as the effect of blocking tumor necrosis factor (TNF on functional impairment in human-TNF transgenic (hTNFtg mice, a chronic inflammatory erosive animal model of RA. We determined CatWalk-assisted gait profiles as objective quantitative measurements of functional impairment. We first determined body-weight-independent gait parameters, including maximum intensity, print length, print width and print area in wild-type mice. We observed early changes in those gait parameters in hTNFtg mice at week 5 – the first clinical signs of arthritis. Moreover, we found further gait changes during chronic disease development, indicating progressive functional impairment in hTNFtg mice. By investigating the association of gait parameters with inflammation-mediated joint pathologies at different time points of the disease course, we found a relationship between gait parameters and the extent of cartilage damage and bone erosions, but not with the extent of synovitis in this chronic model. Next, we observed a significant improvement of functional impairment upon blocking TNF, even at progressed stages of disease. However, blocking TNF did not restore full functionality owing to remaining subclinical inflammation and structural microdamage. In conclusion, CatWalk gait analysis provides a useful tool for quantitative

  17. Integration of fluvial erosion factors for predicting landslides along meandering rivers

    Science.gov (United States)

    Chen, Yi-chin; Chang, Kang-tsung; Ho, Jui-yi

    2015-04-01

    River incision and lateral erosion are important geomorphologic processes in mountainous areas of Taiwan. During a typhoon or storm event, the increase of water discharge, flow velocity, and sediment discharge enhances the power of river erosion on channel bank. After the materials on toe of hillslope were removed by river erosion, landslides were triggered at outer meander bends. Although it has been long expected that river erosion can trigger landslide, studies quantifying the effects of river erosion on landslide and the application of river erosion index in landslide prediction are still overlooked. In this study, we investigated the effect of river erosion on landslide in a particular meanders landscape of the Jhoukou River, southern Taiwan. We developed a semi-automatic model to separate meandering lines into several reach segments based on the inflection points and to calculate river erosion indexes, e.g. sinuosity of meander, stream power, and stream order, for each reach segment. This model, then, built the spatial relationship between the reaches and its corresponding hillslopes, of which the toe was eroded by the reach. Based on the spatial relationship, we quantified the correlations between these indexes and landslides triggered by Typhoon Morakot in 2009 to examine the effects of river erosion on landslide. The correlated indexes were then used as landslide predictors in logistic regression model. Results of the study showed that there is no significant correlation between landslide density and meander sinuosity. This may be a result of wider channel dispersing the erosion at a meandering reach. On the other hand, landslide density at concave bank is significantly higher than that at convex bank in the downstream (stream order > 3), but that is almost the same in the upstream (stream order bank. In contrast, river sediment in the downstream is an erosion agent eroding the concave bank laterally, but also depositing on the concave side and protecting

  18. Angled BIO-RSA (bony-increased offset-reverse shoulder arthroplasty): a solution for the management of glenoid bone loss and erosion.

    Science.gov (United States)

    Boileau, Pascal; Morin-Salvo, Nicolas; Gauci, Marc-Olivier; Seeto, Brian L; Chalmers, Peter N; Holzer, Nicolas; Walch, Gilles

    2017-12-01

    Glenoid deficiency and erosion (excessive retroversion/inclination) must be corrected in reverse shoulder arthroplasty (RSA) to avoid prosthetic notching or instability and to maximize function, range of motion, and prosthesis longevity. This study reports the results of RSA with an angled, autologous glenoid graft harvested from the humerus (angled BIO-RSA). A trapezoidal bone graft, harvested from the humeral head and fixed with a long-post baseplate and screws, was used to compensate for residual glenoid bone loss/erosion. For simple to moderate (25°) and complex (multiplanar) glenoid bone defects, patient-specific grafts and guides were used after 3-dimensional planning. Patients were reviewed with minimum 2 years of follow-up. Mean follow-up was 36 months (range, 24-81 months). Preoperative and postoperative measurements of inclination and version were performed in the plane of the scapula on computed tomography images. The study included 54 patients (41 women, 13 men; mean 73 years old). Fifteen patients had combined vertical and horizontal glenoid bone deficiency. Among E2/E3 glenoids, inclination improved from 37° (range, 14° to 84°) to 10.2° (range -28° to 36°, P RSA predictably corrects glenoid deficiency, including severe (>25°) multiplanar deformity. Graft incorporation is predictable. Advantages of using an autograftharvested in situ include bone stock augmentation, lateralization, low donor-site morbidity, low relative cost, and flexibility needed to simultaneously correct posterior and superior glenoid defects. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

  19. 7 CFR 610.12 - Equations for predicting soil loss due to water erosion.

    Science.gov (United States)

    2010-01-01

    .... (a) The equation for predicting soil loss due to erosion for both the USLE and the RUSLE is A = R × K... 22161.) (b) The factors in the USLE equation are: (1) A is the estimation of average annual soil loss in... 7 Agriculture 6 2010-01-01 2010-01-01 false Equations for predicting soil loss due to water...

  20. Monosodium urate monohydrate crystals inhibit osteoblast viability and function: implications for development of bone erosion in gout.

    Science.gov (United States)

    Chhana, Ashika; Callon, Karen E; Pool, Bregina; Naot, Dorit; Watson, Maureen; Gamble, Greg D; McQueen, Fiona M; Cornish, Jillian; Dalbeth, Nicola

    2011-09-01

    Bone erosion is a common manifestation of chronic tophaceous gout. To investigate the effects of monosodium urate monohydrate (MSU) crystals on osteoblast viability and function. The MTT assay and flow cytometry were used to assess osteoblast cell viability in the MC3T3-E1 and ST2 osteoblast-like cell lines, and primary rat and primary human osteoblasts cultured with MSU crystals. Quantitative real-time PCR and von Kossa stained mineralised bone formation assays were used to assess the effects of MSU crystals on osteoblast differentiation using MC3T3-E1 cells. The numbers of osteoblasts and bone lining cells were quantified in bone samples from patients with gout. MSU crystals rapidly reduced viability in all cell types in a dose-dependent manner. The inhibitory effect on cell viability was independent of crystal phagocytosis and was not influenced by differing crystal length or addition of serum. Long-term culture of MC3T3-E1 cells with MSU crystals showed a reduction in mineralisation and decreased mRNA expression of genes related to osteoblast differentiation such as Runx2, Sp7 (osterix), Ibsp (bone sialoprotein), and Bglap (osteocalcin). Fewer osteoblast and lining cells were present on bone directly adjacent to gouty tophus than bone unaffected by tophus in patients with gout. MSU crystals have profound inhibitory effects on osteoblast viability and differentiation. These data suggest that bone erosion in gout occurs at the tophus-bone interface through alteration of physiological bone turnover, with both excessive osteoclast formation, and reduced osteoblast differentiation from mesenchymal stem cells.

  1. Wind erosion in semiarid landscapes: Predictive models and remote sensing methods for the influence of vegetation

    Science.gov (United States)

    Musick, H. Brad

    1993-01-01

    The objectives of this research are: to develop and test predictive relations for the quantitative influence of vegetation canopy structure on wind erosion of semiarid rangeland soils, and to develop remote sensing methods for measuring the canopy structural parameters that determine sheltering against wind erosion. The influence of canopy structure on wind erosion will be investigated by means of wind-tunnel and field experiments using structural variables identified by the wind-tunnel and field experiments using model roughness elements to simulate plant canopies. The canopy structural variables identified by the wind-tunnel and field experiments as important in determining vegetative sheltering against wind erosion will then be measured at a number of naturally vegetated field sites and compared with estimates of these variables derived from analysis of remotely sensed data.

  2. DES Prediction of Cavitation Erosion and Its Validation for a Ship Scale Propeller

    Science.gov (United States)

    Ponkratov, Dmitriy, Dr

    2015-12-01

    Lloyd's Register Technical Investigation Department (LR TID) have developed numerical functions for the prediction of cavitation erosion aggressiveness within Computational Fluid Dynamics (CFD) simulations. These functions were previously validated for a model scale hydrofoil and ship scale rudder [1]. For the current study the functions were applied to a cargo ship's full scale propeller, on which the severe cavitation erosion was reported. The performed Detach Eddy Simulation (DES) required a fine computational mesh (approximately 22 million cells), together with a very small time step (2.0E-4 s). As the cavitation for this type of vessel is primarily caused by a highly non-uniform wake, the hull was also included in the simulation. The applied method under predicted the cavitation extent and did not fully resolve the tip vortex; however, the areas of cavitation collapse were captured successfully. Consequently, the developed functions showed a very good prediction of erosion areas, as confirmed by comparison with underwater propeller inspection results.

  3. Biochemical markers predictive for bone marrow involvement in systemic mastocytosis

    NARCIS (Netherlands)

    Donker, Marjolein L.; van Doormaal, Jasper J.; van Doormaal, Frederiek F.; Kluin, Philip M.; van der Veer, Eveline; de Monchy, Jan G. R.; Kema, Ido P.; Kluin-Nelemans, Hanneke C.

    Systemic mastocytosis is characterized by bone marrow involvement, which requires a bone marrow biopsy for diagnostic work-up. We questioned whether bone marrow involvement could be predicted using biochemical markers. We selected patients with various symptoms suggestive of indolent systemic

  4. Predicting rainfall erosivity by momentum and kinetic energy in Mediterranean environment

    Science.gov (United States)

    Carollo, Francesco G.; Ferro, Vito; Serio, Maria A.

    2018-05-01

    Rainfall erosivity is an index that describes the power of rainfall to cause soil erosion and it is used around the world for assessing and predicting soil loss on agricultural lands. Erosivity can be represented in terms of both rainfall momentum and kinetic energy, both calculated per unit time and area. Contrasting results on the representativeness of these two variables are available: some authors stated that momentum and kinetic energy are practically interchangeable in soil loss estimation while other found that kinetic energy is the most suitable expression of rainfall erosivity. The direct and continuous measurements of momentum and kinetic energy by a disdrometer allow also to establish a relationship with rainfall intensity at the study site. At first in this paper a comparison between the momentum-rainfall intensity relationships measured at Palermo and El Teularet by an optical disdrometer is presented. For a fixed rainfall intensity the measurements showed that the rainfall momentum values measured at the two experimental sites are not coincident. However both datasets presented a threshold value of rainfall intensity over which the rainfall momentum assumes a quasi-constant value. Then the reliability of a theoretically deduced relationship, linking momentum, rainfall intensity and median volume diameter, is positively verified using measured raindrop size distributions. An analysis to assess which variable, momentum or kinetic energy per unit area and time, is the best predictor of erosivity in Italy and Spain was also carried out. This investigation highlighted that the rainfall kinetic energy per unit area and time can be substituted by rainfall momentum as index for estimating the rainfall erosivity, and this result does not depend on the site where precipitation occurs. Finally, rainfall intensity measurements and soil loss data collected from the bare plots equipped at Sparacia experimental area were used to verify the reliability of some

  5. Prediction of mechanical properties of trabecular bone using quantitative MRI

    International Nuclear Information System (INIS)

    Lammentausta, E; Hakulinen, M A; Jurvelin, J S; Nieminen, M T

    2006-01-01

    Techniques for quantitative magnetic resonance imaging (MRI) have been developed for non-invasive estimation of the mineral density and structure of trabecular bone. The R* 2 relaxation rate (i.e. 1/T* 2 ) is sensitive to bone mineral density (BMD) via susceptibility differences between trabeculae and bone marrow, and by binarizing MRI images, structural variables, such as apparent bone volume fraction, can be assessed. In the present study, trabecular bone samples of human patellae were investigated in vitro at 1.5 T to determine the ability of MRI-derived variables (R* 2 and bone volume fraction) to predict the mechanical properties (Young's modulus, yield stress and ultimate strength). Further, the MRI variables were correlated with reference measurements of volumetric BMD and bone area fraction as determined with a clinical pQCT system. The MRI variables correlated significantly (p 2 and MRI-derived bone volume fraction further improved the prediction of yield stress and ultimate strength. Although pQCT showed a trend towards better prediction of the mechanical properties, current results demonstrate the feasibility of combined MR imaging of marrow susceptibility and bone volume fraction in predicting the mechanical strength of trabecular bone and bone mineral density

  6. How to diagnose rheumatoid arthritis early: a prediction model for persistent (erosive) arthritis

    NARCIS (Netherlands)

    Visser, Henk; le Cessie, Saskia; Vos, Koen; Breedveld, Ferdinand C.; Hazes, Johanna M. W.

    2002-01-01

    To develop a clinical model for the prediction, at the first visit, of 3 forms of arthritis outcome: self-limiting, persistent nonerosive, and persistent erosive arthritis. A standardized diagnostic evaluation was performed on 524 consecutive, newly referred patients with early arthritis.

  7. 75 FR 75961 - Notice of Implementation of the Wind Erosion Prediction System for Soil Erodibility System...

    Science.gov (United States)

    2010-12-07

    ... implementation of the WEPS system does not affect the Highly Erodible Map Unit List contained in the NRCS Field Office Technical Guide as of January 1, 1990. This 1990 list will continue to be used for all erodibility... plant damage, and predict PM-10 emissions when wind speeds exceed the erosion threshold. The WEPS model...

  8. Evaluation of different machine learning models for predicting and mapping the susceptibility of gully erosion

    Science.gov (United States)

    Rahmati, Omid; Tahmasebipour, Nasser; Haghizadeh, Ali; Pourghasemi, Hamid Reza; Feizizadeh, Bakhtiar

    2017-12-01

    Gully erosion constitutes a serious problem for land degradation in a wide range of environments. The main objective of this research was to compare the performance of seven state-of-the-art machine learning models (SVM with four kernel types, BP-ANN, RF, and BRT) to model the occurrence of gully erosion in the Kashkan-Poldokhtar Watershed, Iran. In the first step, a gully inventory map consisting of 65 gully polygons was prepared through field surveys. Three different sample data sets (S1, S2, and S3), including both positive and negative cells (70% for training and 30% for validation), were randomly prepared to evaluate the robustness of the models. To model the gully erosion susceptibility, 12 geo-environmental factors were selected as predictors. Finally, the goodness-of-fit and prediction skill of the models were evaluated by different criteria, including efficiency percent, kappa coefficient, and the area under the ROC curves (AUC). In terms of accuracy, the RF, RBF-SVM, BRT, and P-SVM models performed excellently both in the degree of fitting and in predictive performance (AUC values well above 0.9), which resulted in accurate predictions. Therefore, these models can be used in other gully erosion studies, as they are capable of rapidly producing accurate and robust gully erosion susceptibility maps (GESMs) for decision-making and soil and water management practices. Furthermore, it was found that performance of RF and RBF-SVM for modelling gully erosion occurrence is quite stable when the learning and validation samples are changed.

  9. Prediction for disruption erosion of ITER plasma facing components; a comparison of experimental and numerical results

    International Nuclear Information System (INIS)

    Laan, J.G. van der; Akiba, M.; Seki, M.; Hassanein, A.; Tanchuk, V.

    1991-01-01

    An evaluation is given for the prediction for disruption erosion in the International Thermonuclear Engineering Reactor (ITER). At first, a description is given of the relation between plasma operating paramters and system dimensions to the predictions of loading parameters of Plasma Facing Components (PFC) in off-normal events. Numerical results from ITER parties on the prediction of disruption erosion are compared for a few typical cases and discussed. Apart from some differences in the codes, the observed discrepancies can be ascribed to different input data of material properties and boundary conditions. Some physical models for vapour shielding and their effects on numerical results are mentioned. Experimental results from ITER parties, obtained with electron and laser beams, are also compared. Erosion rates for the candidate ITER PFC materials are shown to depend very strongly on the energy deposition parameters, which are based on plasma physics considerations, and on the assumed material loss mechanisms. Lifetimes estimates for divertor plate and first wall armour are given for carbon, tungsten and beryllium, based on the erosion in the thermal quench phase. (orig.)

  10. New predictive model for monitoring bone remodeling

    Czech Academy of Sciences Publication Activity Database

    Bougherara, H.; Klika, Václav; Maršík, František; Mařík, I.; Yahia, L.H.

    95A, č. 1 (2010), s. 9-24 ISSN 1549-3296 R&D Projects: GA ČR GA106/03/1073; GA ČR(CZ) GA106/03/0958 Institutional research plan: CEZ:AV0Z20760514 Keywords : bone remodeling * open system thermodynamics * bone biochemistry Subject RIV: BJ - Thermodynamics Impact factor: 3.044, year: 2010

  11. Improved USLE-K factor prediction: A case study on water erosion areas in China

    Directory of Open Access Journals (Sweden)

    Bin Wang

    2016-09-01

    Full Text Available Soil erodibility (K-factor is an essential factor in soil erosion prediction and conservation practises. The major obstacles to any accurate, large-scale soil erodibility estimation are the lack of necessary data on soil characteristics and the misuse of variable K-factor calculators. In this study, we assessed the performance of available erodibility estimators Universal Soil Loss Equation (USLE, Revised Universal Soil Loss Equation (RUSLE, Erosion Productivity Impact Calculator (EPIC and the Geometric Mean Diameter based (Dg model for different geographic regions based on the Chinese soil erodibility database (CSED. Results showed that previous estimators overestimated almost all K-values. Furthermore, only the USLE and Dg approaches could be directly and reliably applicable to black and loess soil regions. Based on the nonlinear best fitting techniques, we improved soil erodibility prediction by combining Dg and soil organic matter (SOM. The NSE, R2 and RE values were 0.94, 0.67 and 9.5% after calibrating the results independently; similar model performance was showed for the validation process. The results obtained via the proposed approach were more accurate that the former K-value predictions. Moreover, those improvements allowed us to effectively establish a regional soil erodibility map (1:250,000 scale of water erosion areas in China. The mean K-value of Chinese water erosion regions was 0.0321 (t ha h·(ha MJ mm−1 with a standard deviation of 0.0107 (t ha h·(ha MJ mm−1; K-values present a decreasing trend from North to South in water erosion areas in China. The yield soil erodibility dataset also satisfactorily corresponded to former K-values from different scales (local, regional, and national.

  12. Predicting vertebral bone strength by vertebral static histomorphometry

    DEFF Research Database (Denmark)

    Thomsen, Jesper Skovhus; Ebbesen, Ebbe Nils; Mosekilde, Lis

    2002-01-01

    of the entire vertebral bodies (L-2) were used for histomorphometry. The other iliac crest biopsies and the L-3 were destructively tested by compression. High correlation was found between BV/TV or Tb.Sp and vertebral bone strength (absolute value of r = 0.86 in both cases). Addition of Tb.Th significantly....... No gender-related differences were found in any of the relationships. Neither static histomorphometry nor biomechanical testing of iliac crest bone biopsies is a good predictor of vertebral bone strength.......The study investigates the relationship between static histomorphometry and bone strength of human lumbar vertebral bone. The ability of vertebral histomorphometry to predict vertebral bone strength was compared with that of vertebral densitometry, and also with histomorphometry and bone strength...

  13. Soil erosion model predictions using parent material/soil texture-based parameters compared to using site-specific parameters

    Science.gov (United States)

    R. B. Foltz; W. J. Elliot; N. S. Wagenbrenner

    2011-01-01

    Forested areas disturbed by access roads produce large amounts of sediment. One method to predict erosion and, hence, manage forest roads is the use of physically based soil erosion models. A perceived advantage of a physically based model is that it can be parameterized at one location and applied at another location with similar soil texture or geological parent...

  14. Pelton turbine Needle erosion prediction based on 3D three- phase flow simulation

    International Nuclear Information System (INIS)

    Chongji, Z; Yexiang, X; Wei, Z; Yangyang, Y; Lei, C; Zhengwei, W

    2014-01-01

    Pelton turbine, which applied to the high water head and small flow rate, is widely used in the mountainous area. During the operation period the sediment contained in the water does not only induce the abrasion of the buckets, but also leads to the erosion at the nozzle which may damage the needle structure. The nozzle and needle structure are mainly used to form high quality cylindrical jet and increase the efficiency of energy exchange in the runner to the most. Thus the needle erosion will lead to the deformation of jet, and then may cause the efficiency loss and cavitation. The favourable prediction of abrasion characteristic of needle can effectively guide the optimization design and maintenance of needle structure. This paper simulated the unsteady three-dimensional multi-phase flow in the nozzle and injected jet flow. As the jet containing water and sediment is injected into the free atmosphere air with high velocity, the VOF model was adopted to predict the water and air flow. The sediment is simplified into round solid particle and the discrete particle model (DPM) was employed to predict the needle abrasion characteristic. The sand particle tracks were analyzed to interpret the mechanism of sand erosion on the needle surface. And the numerical result of needle abrasion was obtained and compared with the abrasion field observation. The similarity of abrasion pattern between the numerical results and field observation illustrated the validity of the 3D multi-phase flow simulation method

  15. Pelton turbine Needle erosion prediction based on 3D three- phase flow simulation

    Science.gov (United States)

    Chongji, Z.; Yexiang, X.; Wei, Z.; Yangyang, Y.; Lei, C.; Zhengwei, W.

    2014-03-01

    Pelton turbine, which applied to the high water head and small flow rate, is widely used in the mountainous area. During the operation period the sediment contained in the water does not only induce the abrasion of the buckets, but also leads to the erosion at the nozzle which may damage the needle structure. The nozzle and needle structure are mainly used to form high quality cylindrical jet and increase the efficiency of energy exchange in the runner to the most. Thus the needle erosion will lead to the deformation of jet, and then may cause the efficiency loss and cavitation. The favourable prediction of abrasion characteristic of needle can effectively guide the optimization design and maintenance of needle structure. This paper simulated the unsteady three-dimensional multi-phase flow in the nozzle and injected jet flow. As the jet containing water and sediment is injected into the free atmosphere air with high velocity, the VOF model was adopted to predict the water and air flow. The sediment is simplified into round solid particle and the discrete particle model (DPM) was employed to predict the needle abrasion characteristic. The sand particle tracks were analyzed to interpret the mechanism of sand erosion on the needle surface. And the numerical result of needle abrasion was obtained and compared with the abrasion field observation. The similarity of abrasion pattern between the numerical results and field observation illustrated the validity of the 3D multi-phase flow simulation method.

  16. EVALUATION OF IL1-α AND TNF-α SERUM LEVELS IN RHEUMATOID ARTHRITIS PATIONTS WITH ACTIVE AND INACTIVE, WITH OR WITHOUT BONE EROSION

    Directory of Open Access Journals (Sweden)

    AR. Rostamian

    2007-09-01

    Full Text Available Rheumatoid arthritis is the most common inflammatory joint disease with 1 percent prevalence in community which presents with symmetrical polyarthritis of hands with inflammatory behavior. Several studies in recent years were conducted for evaluation of inflammatory cytokines such as IL1-α (Interlukin 1α and TNF- α (Tumor necrosis factor in rheumatologic disorders including rheumatoid arthritis to find new treatment methods base to pathogenesis. In this study different serum levels of IL1-α and TNF- α in 160 rheumatoid arthritis patients with active and inactive disease and also disease with or without bone erosion are assessed. 4% of our patients had rheumatoid nodule and 70% of all patients had positive RF, IL1-α, and TNF- α levels. Active with bone erosion patients had IL1-α and TNF- α serum levels higher than active without bone erosion patients; it was not significant in T-test but it was significant in Mann-Whitney Test. The results was the same as expected; IL1-α, and TNF- α serum levels were higher in active with bone erosion in comparison with inactive without bone erosion patients.

  17. [Advance in researches on vegetation cover and management factor in the soil erosion prediction model].

    Science.gov (United States)

    Zhang, Yan; Yuan, Jianping; Liu, Baoyuan

    2002-08-01

    Vegetation cover and land management are the main limiting factors of soil erosion, and quantitative evaluation on the effect of different vegetation on soil erosion is essential to land use and soil conservation planning. The vegetation cover and management factor (C) in the universal soil loss equation (USLE) is an index to evaluate this effect, which has been studied deeply and used widely. However, the C factor study is insufficient in China. In order to strengthen the research of C factor, this paper reviewed the developing progress of C factor, and compared the methods of estimating C value in different USLE versions. The relative studies in China were also summarized from the aspects of vegetation canopy coverage, soil surface cover, and root density. Three problems in C factor study were pointed out. The authors suggested that cropland C factor research should be furthered, and its methodology should be unified in China to represent reliable C values for soil loss prediction and conservation planning.

  18. The performance of MRI in detecting subarticular bone erosion of sacroiliac joint in patients with spondyloarthropathy: A comparison with X-ray and CT

    International Nuclear Information System (INIS)

    Hu, Libin; Huang, Zhenguo; Zhang, Xuezhe; Chan, Queenie; Xu, Yanyan; Wang, Guochun; Wang, Wu

    2014-01-01

    Highlights: • MRI 3D-WS-bSSFP sequence has high spatial resolution and short scanning time. • This is the first time this sequence was applied to detect bone erosion of SI joint. • Its performance was compared with other commonly used diagnostic methods. • Result shows that this sequence is better than X-ray and T1W in the detection of bone erosion. • This sequence can be considered an alternative to CT in showing erosion in SpA patients. - Abstract: Objective: To assess the sensitivity and specificity of detecting subarticular bone erosion of sacroiliac (SI) joint in patients with spondyloarthritis (SpA) using MRI three-dimensional water selective balanced steady-state free precession sequence (3D-WS-bSSFP) and T1-weighted (T1W) sequence. Materials and methods: Radiography, CT and MRI of SI joint from 43 SpA patients were retrospectively analyzed. MRI examination sequences include T1W, short tau inversion recovery (STIR) and 3D-WS-bSSFP. Two radiologists, blinded to clinical data, independently determined bone erosion at bilateral sacral and iliac sides of the SI joint on radiography, CT, T1W and 3D-WS-bSSFP respectively. X 2 test was used to compare the sensitivity of detecting bone erosion among different diagnostic methods. Results: Of the 86 sacral and 86 iliac articular surfaces from the 43 cases, radiography, CT, MRI T1W and 3D-WS-bSSFP showed the presence of bone erosion in 40, 74, 50 and 71 articular surfaces respectively. CT and MRI 3D-WS-bSSFP demonstrated similar sensitivity (x 2 = 0.11, P = 0.74), and both were superior to radiography (x 2 = 15.17, P < 0.01 and x 2 = 12.78, P < 0.01, respectively) and T1W (x 2 = 7.26, P < 0.01 and x 2 = 5.62, P < 0.05). Using CT diagnosis as the gold standard, the sensitivity and specificity of detecting bone erosion for MRI 3D-WS-bSSFP and T1W sequences were 91.8%, 96.9%, and 60.8%, 94.9% respectively. Conclusion: MRI 3D-WS-bSSFP sequence is associated with short scanning time, zero ionizing radiation, high

  19. The performance of MRI in detecting subarticular bone erosion of sacroiliac joint in patients with spondyloarthropathy: A comparison with X-ray and CT

    Energy Technology Data Exchange (ETDEWEB)

    Hu, Libin [Department of Radiology, China-Japan Friendship Hospital, Beijing (China); Huang, Zhenguo, E-mail: zhuang680911@163.com [Department of Radiology, China-Japan Friendship Hospital, Beijing (China); Zhang, Xuezhe [Department of Radiology, China-Japan Friendship Hospital, Beijing (China); Chan, Queenie [Philips Healthcare, Hong Kong (China); Xu, Yanyan [Department of Radiology, China-Japan Friendship Hospital, Beijing (China); Wang, Guochun [Department of Rheumatology, China-Japan Friendship Hospital, Beijing (China); Wang, Wu [Department of Radiology, China-Japan Friendship Hospital, Beijing (China)

    2014-11-15

    Highlights: • MRI 3D-WS-bSSFP sequence has high spatial resolution and short scanning time. • This is the first time this sequence was applied to detect bone erosion of SI joint. • Its performance was compared with other commonly used diagnostic methods. • Result shows that this sequence is better than X-ray and T1W in the detection of bone erosion. • This sequence can be considered an alternative to CT in showing erosion in SpA patients. - Abstract: Objective: To assess the sensitivity and specificity of detecting subarticular bone erosion of sacroiliac (SI) joint in patients with spondyloarthritis (SpA) using MRI three-dimensional water selective balanced steady-state free precession sequence (3D-WS-bSSFP) and T1-weighted (T1W) sequence. Materials and methods: Radiography, CT and MRI of SI joint from 43 SpA patients were retrospectively analyzed. MRI examination sequences include T1W, short tau inversion recovery (STIR) and 3D-WS-bSSFP. Two radiologists, blinded to clinical data, independently determined bone erosion at bilateral sacral and iliac sides of the SI joint on radiography, CT, T1W and 3D-WS-bSSFP respectively. X{sup 2} test was used to compare the sensitivity of detecting bone erosion among different diagnostic methods. Results: Of the 86 sacral and 86 iliac articular surfaces from the 43 cases, radiography, CT, MRI T1W and 3D-WS-bSSFP showed the presence of bone erosion in 40, 74, 50 and 71 articular surfaces respectively. CT and MRI 3D-WS-bSSFP demonstrated similar sensitivity (x{sup 2} = 0.11, P = 0.74), and both were superior to radiography (x{sup 2} = 15.17, P < 0.01 and x{sup 2} = 12.78, P < 0.01, respectively) and T1W (x{sup 2} = 7.26, P < 0.01 and x{sup 2} = 5.62, P < 0.05). Using CT diagnosis as the gold standard, the sensitivity and specificity of detecting bone erosion for MRI 3D-WS-bSSFP and T1W sequences were 91.8%, 96.9%, and 60.8%, 94.9% respectively. Conclusion: MRI 3D-WS-bSSFP sequence is associated with short scanning time

  20. Development of a mobile application based on RUSLE model to predict erosion in olive groves

    Science.gov (United States)

    Marín Moreno, Víctor Javier; Redel, María Dolores; Taguas, Encarnación V.

    2017-04-01

    Apache Cordova, which are very efficient to facilitate its implementation in most of mobile platforms. The first evaluations from farmers and technicians are also presented in order to improve the first version. References: - Areal, F.J., Riesgo, L., 2014. Farmers' views on the future of olive farming in Andalusia, Spain. Land Use Policy 36 (2014) 543- 553. - CAPyDR, 2016. Aforo de producción de olivar en Andalucía, Campaña 2016-2017. Consejería de Agricultura, Pesca y Desarrollo Rural - Junta de Andalucía. Regional Government of Andalusia, Seville (2016) (Spain) - FAOSTAT -2016. FOOD AND AGRICULTURE ORGANIZATION OF THE UNITED NATIONS STATISTICS. Accessed at: http://www.fao.org/faostat - Franco, J.A., 2011. Análisis de los factores de participación en programas agroambientales de lucha contra la erosión en el olivar. ITEA 107 (3), 169-183. - Renard, K. G., Foster, G. R., Wessies, G. A., Mccool, D. K., and Yoder, D. C., 1997. Predicting Soil Ero¬sion by Water: A Guide to Conservation Planning with the Revised Universal LossEquation (RUSLE). USDA Agriculture Handbook, No. 703. - Taguas, E.V., Gómez, J.A., 2015. Vulnerability of olive orchards under the current CAP (Common Agricultural Policy) regulations on soil erosion: a study case in Southern Spain. Land Use Policy, 42, 683-694

  1. Prediction of the Setting Properties of Calcium Phosphate Bone Cement

    Directory of Open Access Journals (Sweden)

    Seyed Mahmud Rabiee

    2012-01-01

    Full Text Available Setting properties of bone substitutes are improved using an injectable system. The injectable bone graft substitutes can be molded to the shape of the bone cavity and set in situ when injected. Such system is useful for surgical operation. The powder part of the injectable bone cement is included of β-tricalcium phosphate, calcium carbonate, and dicalcium phosphate and the liquid part contains poly ethylene glycol solution with different concentrations. In this way, prediction of the mechanical properties, setting times, and injectability helps to optimize the calcium phosphate bone cement properties. The objective of this study is development of three different adaptive neurofuzzy inference systems (ANFISs for estimation of compression strength, setting time, and injectability using the data generated based on experimental observations. The input parameters of models are polyethylene glycol percent and liquid/powder ratio. Comparison of the predicted values and measured data indicates that the ANFIS model has an acceptable performance to the estimation of calcium phosphate bone cement properties.

  2. Utility of combined high-resolution bone SPECT and MRI for the identification of rheumatoid arthritis patients with high-risk for erosive progression

    Energy Technology Data Exchange (ETDEWEB)

    Buchbender, Christian, E-mail: christian.buchbender@med.uni-duesseldorf.de [Univ Dusseldorf, Medical Faculty, Department of Diagnostic and Interventional Radiology, Moorenstr. 5, D-40225 Dusseldorf (Germany); Sewerin, Philipp, E-mail: philipp.sewerin@med.uni-duesseldorf.de [Univ Dusseldorf, Medical Faculty, Department of Rheumatology, Moorenstr. 5, D-40225 Dusseldorf (Germany); Mattes-György, Katalin, E-mail: katalin.mattes@med.uni-duesseldorf.de [Univ Dusseldorf, Medical Faculty, Department of Nuclear Medicine, Moorenstr. 5, D-40225 Dusseldorf (Germany); Miese, Falk, E-mail: falk.miese@med.uni-duesseldorf.de [Univ Dusseldorf, Medical Faculty, Department of Diagnostic and Interventional Radiology, Moorenstr. 5, D-40225 Dusseldorf (Germany); Wittsack, Hans-Joerg, E-mail: hans-joerg.wittsack@med.uni-duesseldorf.de [Univ Dusseldorf, Medical Faculty, Department of Diagnostic and Interventional Radiology, Moorenstr. 5, D-40225 Dusseldorf (Germany); Specker, Christof, E-mail: c.specker@kliniken-essen-sued.de [Department of Rheumatology and Clinical Immunology, Kliniken Essen-Sud, Propsteistrasse 2, D-45239 Essen (Germany); Antoch, Gerald, E-mail: antoch@med.uni-duesseldorf.de [Univ Dusseldorf, Medical Faculty, Department of Diagnostic and Interventional Radiology, Moorenstr. 5, D-40225 Dusseldorf (Germany); Müller, Hans-Wilhelm, E-mail: HansW.Mueller@med.uni-duesseldorf.de [Univ Dusseldorf, Medical Faculty, Department of Nuclear Medicine, Moorenstr. 5, D-40225 Dusseldorf (Germany); Schneider, Matthias, E-mail: matthias.schneider@med.uni-duesseldorf.de [Univ Dusseldorf, Medical Faculty, Department of Rheumatology, Moorenstr. 5, D-40225 Dusseldorf (Germany); Scherer, Axel, E-mail: scherer@med.uni-duesseldorf.de [Univ Dusseldorf, Medical Faculty, Department of Diagnostic and Interventional Radiology, Moorenstr. 5, D-40225 Dusseldorf (Germany); Ostendorf, Benedikt, E-mail: ostendorf@med.uni-duesseldorf.de [Univ Dusseldorf, Medical Faculty, Department of Rheumatology, Moorenstr. 5, D-40225 Dusseldorf (Germany)

    2013-02-15

    Objectives: To evaluate the utility of sequentially acquired, post hoc fused, magnetic resonance imaging (MRI) and multi-pinhole single photon emission computed tomography (MPH-SPECT) with technetium-99m-labeled disphosphonates (Tc99m-DPD) for the identification of finger joints with later erosive progression in early rheumatoid arthritis (ERA) patients. Methods: Ten consecutive ERA patients prospectively underwent MPH-SPECT and MRI of metacarpophalangeal (MCP) joints prior to and after 6 months methotrexate therapy. Tc99m-DPD uptake was measured at proximal and distal MCP sites using regional analysis. The course of joint pathologies was scored according to the Rheumatoid Arthritis MRI Score (RAMRIS) criteria. Results: The frequency of increased Tc99m-DPD uptake, synovitis and bone marrow edemadecreased under MTX therapy; but the number of bone erosions increased. Joints with progressive and new erosions on follow-up had a higher baseline Tc99m-DPD uptake (2.64 ± 1.23 vs. 1.43 ± 0.91) (p = 0.02). Conclusions: Joints with erosive progression are characterized by an early increased Tc99m-DPD uptake, even in absence of MRI bone pathologies. Tc99m-DPD MPH-SPECT might thus be of additional value to morphological MRI for the identification of RA patients with a high risk for erosive progression.

  3. Testing and prediction of erosion-corrosion for corrosion resistant alloys used in the oil and gas production industry

    Science.gov (United States)

    Rincon, Hernan E.

    The corrosion behavior of CRAs has been thoroughly investigated and documented in the public literature by many researchers; however, little work has been done to investigate erosion-corrosion of such alloys. When sand particles are entrained in the flow, the degradation mechanism is different from that observed for sand-free corrosive environment. There is a need in the oil and gas industry to define safe service limits for utilization of such materials. The effects of flow conditions, sand rate, pH and temperature on the erosion-corrosion of CRAs were widely studied. An extensive experimental work was conducted using scratch tests and flow loop tests using several experimental techniques. At high erosivity conditions, a synergistic effect between erosion and corrosion was observed. Under the high sand rate conditions tested, erosivity is severe enough to damage the passive layer protecting the CRA thereby enhancing the corrosion rate. In most cases there is likely a competition between the rates of protective film removal due to mechanical erosion and protective film healing. Synergism occurs for each of the three alloys examined (13Cr and Super13Cr and 22Cr); however, the degree of synergism is quite different for the three alloys and may not be significant for 22Cr for field conditions where erosivities are typically much lower that those occurring in the small bore loop used in this research. Predictions of the corrosion component of erosion-corrosion based on scratch test data compared reasonably well to test results from flow loops for the three CRAs at high erosivity conditions. Second order behavior appears to be an appropriate and useful model for representing the repassivation process of CRAs. A framework for a procedure to predict penetration rates for erosion-corrosion conditions was developed based on the second order model behavior observed for the re-healing process of the passive film of CRAs and on computational fluid dynamics (CFD) simulations

  4. Scoring of synovial membrane hypertrophy and bone erosions by MR imaging in clinically active and inactive rheumatoid arthritis of the wrist

    DEFF Research Database (Denmark)

    Østergaard, Mikkel; Gideon, P; Sørensen, K

    1995-01-01

    MRI-scores of synovial membrane hypertrophy and bone erosions of the RA-wrist are introduced. Gadolinium-DTPA enhanced magnetic resonance imaging (MRI) and conventional radiography (CR) of the wrist were performed in 16 patients with rheumatoid arthritis (RA) and 3 healthy controls. A MRI...

  5. Particle Impact Erosion. Volume 4. User’s Manual Erosion Prediction Procedure for Rocket Nozzle Expansion Region

    Science.gov (United States)

    1983-05-01

    empirical erosion model, with use of the debris-layer model optional. 1.1 INTERFACE WITH ISPP ISPP is a collection of computer codes designed to calculate...expansion with the ODK code, 4. A two-dimensional, two-phase nozzle expansion with the TD2P code, 5. A turbulent boundary layer solution along the...INPUT THERMODYNAMIC DATA FOR TEMPERATURESBELOW 300°K OIF NEEDED) NO A• 11 READ SSP NAMELIST (ODE. BAL. ODK . TD2P. TEL. NOZZLE GEOMETRY) PROfLM 2

  6. KwaZulu-Natal coastal erosion events of 2006/2007 and 2011: A predictive tool?

    OpenAIRE

    Alan Smith; Lisa A. Guastella; Andrew A. Mather; Simon C. Bundy; Ivan D. Haigh

    2013-01-01

    Severe coastal erosion occurred along the KwaZulu-Natal coastline between mid-May and November 2011. Analysis of this erosion event and comparison with previous coastal erosion events in 2006/2007 offered the opportunity to extend the understanding of the time and place of coastal erosion strikes. The swells that drove the erosion hotspots of the 2011 erosion season were relatively low (significant wave heights were between 2 m and 4.5 m) but of long duration. Although swell height was import...

  7. Measurement of erosion: Is it possible?

    NARCIS (Netherlands)

    Stroosnijder, L.

    2005-01-01

    Reasons for erosion measurements are: (1) to determine the environmental impact of erosion and conservation practices, (2) scientific erosion research; (3) development and evaluation of erosion control technology; (4) development of erosion prediction technology and (5) allocation of conservation

  8. Prediction of trabecular bone qualitative properties using scanning quantitative ultrasound

    Science.gov (United States)

    Qin, Yi-Xian; Lin, Wei; Mittra, Erik; Xia, Yi; Cheng, Jiqi; Judex, Stefan; Rubin, Clint; Müller, Ralph

    2013-11-01

    Microgravity induced bone loss represents a critical health problem in astronauts, particularly occurred in weight-supporting skeleton, which leads to osteopenia and increase of fracture risk. Lack of suitable evaluation modality makes it difficult for monitoring skeletal status in long term space mission and increases potential risk of complication. Such disuse osteopenia and osteoporosis compromise trabecular bone density, and architectural and mechanical properties. While X-ray based imaging would not be practical in space, quantitative ultrasound may provide advantages to characterize bone density and strength through wave propagation in complex trabecular structure. This study used a scanning confocal acoustic diagnostic and navigation system (SCAN) to evaluate trabecular bone quality in 60 cubic trabecular samples harvested from adult sheep. Ultrasound image based SCAN measurements in structural and strength properties were validated by μCT and compressive mechanical testing. This result indicated a moderately strong negative correlations observed between broadband ultrasonic attenuation (BUA) and μCT-determined bone volume fraction (BV/TV, R2=0.53). Strong correlations were observed between ultrasound velocity (UV) and bone's mechanical strength and structural parameters, i.e., bulk Young's modulus (R2=0.67) and BV/TV (R2=0.85). The predictions for bone density and mechanical strength were significantly improved by using a linear combination of both BUA and UV, yielding R2=0.92 for BV/TV and R2=0.71 for bulk Young's modulus. These results imply that quantitative ultrasound can characterize trabecular structural and mechanical properties through measurements of particular ultrasound parameters, and potentially provide an excellent estimation for bone's structural integrity.

  9. Bone Marrow Pathology Predicts Mortality in Chronic Hemodialysis Patients

    Directory of Open Access Journals (Sweden)

    Cheng-Hao Weng

    2015-01-01

    Full Text Available Introduction. A bone marrow biopsy is a useful procedure for the diagnosis and staging of various hematologic and systemic diseases. The objective of this study was to investigate whether the findings of bone marrow studies can predict mortality in chronic hemodialysis patients. Methods. Seventy-eight end-stage renal disease patients on maintenance hemodialysis underwent bone marrow biopsies between 2000 and 2011, with the most common indication being unexplained anemia followed by unexplained leukocytosis and leukopenia. Results. The survivors had a higher incidence of abnormal megakaryocyte distribution P=0.001, band and segmented cells P=0.021, and lymphoid cells P=0.029 than the nonsurvivors. The overall mortality rate was 38.5% (30/78, and the most common cause of mortality was sepsis (83.3% followed by respiratory failure (10%. In multivariate Cox regression analysis, both decreased (OR 3.714, 95% CI 1.671–8.253, P=0.001 and absent (OR 9.751, 95% CI 2.030–45.115, P=0.004 megakaryocyte distribution (normal megakaryocyte distribution as the reference group, as well as myeloid/erythroid ratio (OR 1.054, CI 1.012–1.098, P=0.011, were predictive of mortality. Conclusion. The results of a bone marrow biopsy can be used to assess the pathology, and, in addition, myeloid/erythroid ratio and abnormal megakaryocyte distribution can predict mortality in chronic hemodialysis patients.

  10. Evaluating water erosion prediction project model using Cesium-137-derived spatial soil redistribution data

    Science.gov (United States)

    The lack of spatial soil erosion data has been a major constraint on the refinement and application of physically based erosion models. Spatially distributed models can only be thoroughly validated with distributed erosion data. The fallout cesium-137 has been widely used to generate spatial soil re...

  11. Ultrasound-detected bone erosion is a relapse risk factor after discontinuation of biologic disease-modifying antirheumatic drugs in patients with rheumatoid arthritis whose ultrasound power Doppler synovitis activity and clinical disease activity are well controlled.

    Science.gov (United States)

    Kawashiri, Shin-Ya; Fujikawa, Keita; Nishino, Ayako; Okada, Akitomo; Aramaki, Toshiyuki; Shimizu, Toshimasa; Umeda, Masataka; Fukui, Shoichi; Suzuki, Takahisa; Koga, Tomohiro; Iwamoto, Naoki; Ichinose, Kunihiro; Tamai, Mami; Mizokami, Akinari; Nakamura, Hideki; Origuchi, Tomoki; Ueki, Yukitaka; Aoyagi, Kiyoshi; Maeda, Takahiro; Kawakami, Atsushi

    2017-05-25

    In the present study, we explored the risk factors for relapse after discontinuation of biologic disease-modifying antirheumatic drug (bDMARD) therapy in patients with rheumatoid arthritis (RA) whose ultrasound power Doppler (PD) synovitis activity and clinical disease activity were well controlled. In this observational study in clinical practice, the inclusion criteria were based on ultrasound disease activity and clinical disease activity, set as low or remission (Disease Activity Score in 28 joints based on erythrocyte sedimentation rate Ultrasound was performed in 22 joints of bilateral hands at discontinuation for evaluating synovitis severity and presence of bone erosion. Patients with a maximum PD score ≤1 in each joint were enrolled. Forty patients with RA were consecutively recruited (November 2010-March 2015) and discontinued bDMARD therapy. Variables at the initiation and discontinuation of bDMARD therapy that were predictive of relapse during the 12 months after discontinuation were assessed. The median patient age was 54.5 years, and the median disease duration was 3.5 years. Nineteen (47.5%) patients relapsed during the 12 months after the discontinuation of bDMARD therapy. Logistic regression analysis revealed that only the presence of bone erosion detected by ultrasound at discontinuation was predictive of relapse (OR 8.35, 95% CI 1.78-53.2, p = 0.006). No clinical characteristics or serologic biomarkers were significantly different between the relapse and nonrelapse patients. The ultrasound synovitis scores did not differ significantly between the groups. Our findings are the first evidence that ultrasound bone erosion may be a relapse risk factor after the discontinuation of bDMARD therapy in patients with RA whose PD synovitis activity and clinical disease activity are well controlled.

  12. Anti-RANKL treatment inhibits erosive joint destruction and lowers inflammation but has no effect on bone formation in the delayed-type hypersensitivity arthritis (DTHA) model

    DEFF Research Database (Denmark)

    Atkinson, Sara Marie; Bleil, Janine; Maier, Rene

    2016-01-01

    . Periarticular bone formation was observed from day 10. Induction of new bone formation indicated by enhanced Runx2, collagen X, osteocalcin, MMP2, MMP9, and MMP13 mRNA expression was observed only between days 8 and 11. Anti-RANKL treatment resulted in a modest reduction in paw and ankle swelling...... and bone formation were analyzed by mRNA deep sequencing. Serum concentrations of tartrate-resistant acid phosphatase 5b, carboxy-terminal telopeptide I (CTX-I), matrix metalloproteinase 3 (MMP3), and serum amyloid P component (SAP) were determined by enzyme-linked immunosorbent assay. Anti......-RANKL monoclonal antibody treatment was initiated at the time of immunization. Results: Bone destruction (MMP3 serum levels, cathepsin B activity, and RANKL mRNA) peaked at day 3 after arthritis induction, followed by a peak in cartilage destruction and bone erosion on day 5 after arthritis induction...

  13. A history of wind erosion prediction models in the United States Department of Agriculture Prior to the Wind Erosion Prediction System

    Science.gov (United States)

    The Great Plains experienced an influx of settlers in the late 1850s to 1900. Periodic drought was hard on both settlers and the soil and caused severe wind erosion. The period known as the Dirty Thirties, 1931 to 1939, produced many severe windstorms, and the resulting dusty sky over Washington, D....

  14. Usability and Functional Enhancements to an Online Interface for Predicting Post Fire Erosion (WEPP-PEP)

    Science.gov (United States)

    Lew, Roger; Dobre, Mariana; Elliot, William; Robichaud, Pete; Brooks, Erin; Frankenberger, Jim

    2017-04-01

    There is an increased interest in the United States to use soil burn severity maps in watershed-scale hydrologic models to estimate post-fire sediment erosion from burned areas. This information is needed by stakeholders in order to concentrate their pre- or post-fire management efforts in ecologically sensitive areas to decrease the probability of post-fire sediment delivery. But these tools traditionally have been time consuming and difficult to use by managers because input datasets must be obtained and correctly processed for valid results. The Water Erosion Prediction Project (WEPP) has previously been developed as an online and easy-to-use interface to help land managers with running simulations without any knowledge of computer programming or hydrologic modeling. The interface automates the acquisition of DEM, climate, soils, and landcover data, and also automates channel and hillslope delineation for the users. The backend is built with Mapserver, GDAL, PHP, C++, Python while the front end uses OpenLayers, and, of course, JavaScript. The existing WEPP online interface was enhanced to provide better usability to stakeholders in United States (Forest Service, BLM, USDA) as well as to provide enhanced functionality for managing both pre-fire and post-fire treatments. Previously, only site administrators could add burn severity maps. The interface now allows users to create accounts to upload and share FlamMap prediction maps, differenced Normalized Burned Ratio (dNBR), or Burned Area Reflectance Classification (BARC) maps. All maps are loaded into a sortable catalog so users can quickly find their area of interest. Once loaded, the interface has been modified to support running comparisons between baseline condition with "no burn" and with a burn severity classification map. The interface has also been enhanced to allow users to conduct single storm analyses to examine, for example, how much soil loss would result after a 100-year storm. An OpenLayers map

  15. Watershed-scale evaluation of the Water Erosion Prediction Project (WEPP) model in the Lake Tahoe basin

    Science.gov (United States)

    Erin S. Brooks; Mariana Dobre; William J. Elliot; Joan Q. Wu; Jan Boll

    2016-01-01

    Forest managers need methods to evaluate the impacts of management at the watershed scale. The Water Erosion Prediction Project (WEPP) has the ability to model disturbed forested hillslopes, but has difficulty addressing some of the critical processes that are important at a watershed scale, including baseflow and water yield. In order to apply WEPP to...

  16. Inter-observer reliability of high-resolution ultrasonography in the assessment of bone erosions in patients with rheumatoid arthritis: experience of an intensive dedicated training programme.

    Science.gov (United States)

    Gutierrez, Marwin; Filippucci, Emilio; Ruta, Santiago; Salaffi, Fausto; Blasetti, Patrizia; Di Geso, Luca; Grassi, Walter

    2011-02-01

    The present study was aimed at testing the ability of a rheumatologist without experience in ultrasound (US) who attended an intensive 4-week training programme focused on US assessing bone erosions in the hands and feet in patients with RA. Twenty patients diagnosed with RA according to the ACR criteria were included in the study. All US examinations were performed bilaterally by two investigators (with different experience in the field of musculoskeletal US) at the following sites: the dorsal, lateral and volar aspect of the second metacarpal, ulnar and fifth metatarsal head; and the dorsal and volar aspect of the third metacarpal and second proximal heads. Each quadrant was scanning in longitudinal and transverse scans for assessing the qualitative, semiquantitative and quantitative US findings indicative of bone erosions according the OMERACT preliminary definition. Both κ-values and overall agreement percentages of qualitative and semiquantitative assessments showed moderate to excellent agreement between the two investigators. Similar results were obtained for the quantitative assessment with the concordance correlation coefficient value always significant. The only exception was the volar aspects, in particular those of the fifth metatarsal head. Our study suggests that after a 4-week dedicated training programme, a rheumatologist without experience in US is able to detect and score bone erosions in the hands and feet of patients with RA.

  17. Automated lake-wide erosion predictions and economic damage calculations upstream of the Moses-Saunders power dam

    International Nuclear Information System (INIS)

    Zuzek, P.; Baird, W.F.; International Joint Commission, Ottawa, ON

    2008-01-01

    This presentation discussed an automated flood and erosion prediction system designed for the upstream sections of the Moses-Saunders power dam. The system included a wave prediction component along with 3-D maps, hourly run-ups, geographic information system (GIS) tools and a hazard analysis tool. Parcel, reach, township, and county databases were used to populate the system. The prediction system was used to develop detailed study sites of shore units in the study area. Shoreline classes included sand and cohesive buffs, low banks, coarse beaches, and cobble or boulder lags. Time series plots for Lake Ontario water and wave levels were presented. Great Lakes ice cover data were also included in the system as well as erosion predictions from 1961 to 1995. The system was also used to develop bluff recession equations and cumulative recession analyses for different regulation plans. Cumulative bluff recession and protection requirements were outlined. Screenshots of the flood and erosion prediction system interface were also included. tabs., figs

  18. Soil Erosion Prediction Using Morgan-Morgan-Finney Model in a GIS Environment in Northern Ethiopia Catchment

    Directory of Open Access Journals (Sweden)

    Gebreyesus Brhane Tesfahunegn

    2014-01-01

    Full Text Available Even though scientific information on spatial distribution of hydrophysical parameters is critical for understanding erosion processes and designing suitable technologies, little is known in Geographical Information System (GIS application in developing spatial hydrophysical data inputs and their application in Morgan-Morgan-Finney (MMF erosion model. This study was aimed to derive spatial distribution of hydrophysical parameters and apply them in the Morgan-Morgan-Finney (MMF model for estimating soil erosion in the Mai-Negus catchment, northern Ethiopia. Major data input for the model include climate, topography, land use, and soil data. This study demonstrated using MMF model that the rate of soil detachment varied from 170 t ha−1 y−1, whereas the soil transport capacity of overland flow (TC ranged from 5 t ha−1 y−1 to >42 t ha−1 y−1. The average soil loss estimated by TC using MMF model at catchment level was 26 t ha−1 y−1. In most parts of the catchment (>80%, the model predicted soil loss rates higher than the maximum tolerable rate (18 t ha−1 y−1 estimated for Ethiopia. Hence, introducing appropriate interventions based on the erosion severity predicted by MMF model in the catchment is crucial for sustainable natural resources management.

  19. Development of Erosive Burning Models for CFD Predictions of Solid Rocket Motor Internal Environments

    Science.gov (United States)

    Wang, Qun-Zhen

    2003-01-01

    Four erosive burning models, equations (11) to (14). are developed in this work by using a power law relationship to correlate (1) the erosive burning ratio and the local velocity gradient at propellant surfaces; (2) the erosive burning ratio and the velocity gradient divided by centerline velocity; (3) the erosive burning difference and the local velocity gradient at propellant surfaces; and (4) the erosive burning difference and the velocity gradient divided by centerline velocity. These models depend on the local velocity gradient at the propellant surface (or the velocity gradient divided by centerline velocity) only and, unlike other empirical models, are independent of the motor size. It was argued that, since the erosive burning is a local phenomenon occurring near the surface of the solid propellant, the erosive burning ratio should be independent of the bore diameter if it is correlated with some local flow parameters such as the velocity gradient at the propellant surface. This seems to be true considering the good results obtained by applying these models, which are developed from the small size 5 inch CP tandem motor testing, to CFD simulations of much bigger motors.

  20. Can bone scintigraphy predict the final outcome of pasteurized autografts?

    International Nuclear Information System (INIS)

    Eid, Ahmed Shawky; Jeon, Dae-Geun; Cho, Wan Hyeong

    2010-01-01

    As pasteurization is becoming more widely used in limb salvage reconstruction, more study is required to understand about host-graft junction healing, graft revascularization and incorporation, and the incidence and type of complications among pasteurized autografts. This was mainly achieved by follow-up radiography. We aimed to clarify whether Tc99m bone scanning can be considered a reliable method in determining these three parameters. Twenty-seven osteosarcoma patients with pasteurized autograft reconstructions were retrospectively reviewed using available scintigraphic and radiographic follow-up every 6 months postoperatively for 36 months. Follow-up of the unhealed cases was continued for the maximum follow-up period available for each case beyond the original study period, ranging from 1 to 15 months. Tc99m uptake was classified as cold, faint, moderate and high uptake. Junction healing was classified as none, partial and complete healing. Seventy percent of junctions united with a mean of 22 months. Ninety to 100% of junctions showed increased uptake (high or moderate) at one time of the study regardless of final outcome. 85% of the pasteurized grafts showed the characteristic ''tramline appearance''. Four grafts (15%) were complicated: pseudoarthrosis and implant failure (1), fractured plate (1), intramedullary nail (IMN) fracture (1), and prosthesis stem loosening in the host bone (1), with underlying unhealed junctions in all cases. Bone scanning can determine the stages of the graft's rim revascularization and incorporation; however, it cannot detect or predict junction healing or occurrence of complications. Supplementary treatment of unhealed junctions showing either decreased junctional uptake or graft quiescence may be warranted. Otherwise, detection of distant metastasis and early local recurrence remains the main application of Tc99m scanning in the management of bone sarcomas. (orig.)

  1. Can bone scintigraphy predict the final outcome of pasteurized autografts?

    Energy Technology Data Exchange (ETDEWEB)

    Eid, Ahmed Shawky [Ain Shams University, Department of Orthopedic Surgery, Cairo (Egypt); Jeon, Dae-Geun; Cho, Wan Hyeong [Korea Cancer Center Hospital, Department of Orthopedic Surgery, Seoul (Korea)

    2010-10-15

    As pasteurization is becoming more widely used in limb salvage reconstruction, more study is required to understand about host-graft junction healing, graft revascularization and incorporation, and the incidence and type of complications among pasteurized autografts. This was mainly achieved by follow-up radiography. We aimed to clarify whether Tc99m bone scanning can be considered a reliable method in determining these three parameters. Twenty-seven osteosarcoma patients with pasteurized autograft reconstructions were retrospectively reviewed using available scintigraphic and radiographic follow-up every 6 months postoperatively for 36 months. Follow-up of the unhealed cases was continued for the maximum follow-up period available for each case beyond the original study period, ranging from 1 to 15 months. Tc99m uptake was classified as cold, faint, moderate and high uptake. Junction healing was classified as none, partial and complete healing. Seventy percent of junctions united with a mean of 22 months. Ninety to 100% of junctions showed increased uptake (high or moderate) at one time of the study regardless of final outcome. 85% of the pasteurized grafts showed the characteristic ''tramline appearance''. Four grafts (15%) were complicated: pseudoarthrosis and implant failure (1), fractured plate (1), intramedullary nail (IMN) fracture (1), and prosthesis stem loosening in the host bone (1), with underlying unhealed junctions in all cases. Bone scanning can determine the stages of the graft's rim revascularization and incorporation; however, it cannot detect or predict junction healing or occurrence of complications. Supplementary treatment of unhealed junctions showing either decreased junctional uptake or graft quiescence may be warranted. Otherwise, detection of distant metastasis and early local recurrence remains the main application of Tc99m scanning in the management of bone sarcomas. (orig.)

  2. Crust behavior and erosion rate prediction of EPR sacrificial material impinged by core melt jet

    Energy Technology Data Exchange (ETDEWEB)

    Li, Gen; Liu, Ming, E-mail: ming.liu@mail.xjtu.edu.cn; Wang, Jinshi; Chong, Daotong; Yan, Junjie

    2017-04-01

    Highlights: • A numerical code was developed to analyze melt jet-concrete interaction in the frame of MPS method. • Crust and ablated concrete layer at UO{sub 2}-ZrO{sub 2} melt and concrete interface periodically developed and collapsed. • Concrete surface temperature fluctuated around a low temperature and ablation temperature. • Concrete erosion by Fe-Zr melt jet was significantly faster than that by UO{sub 2}-ZrO{sub 2} melt jet. - Abstract: Sacrificial material is a special ferro-siliceous concrete, designed in the ex-vessel core melt stabilization system of European Pressurized water Reactor (EPR). Given a localized break of RPV lower head, the melt directly impinges onto the dry concrete in form of compact jet. The concrete erosion behavior influences the failure of melt plug, and further affects melt spreading. In this study, a numerical code was developed in the frame of Moving Particle Semi-implicit (MPS) method, to analyze the crust behavior and erosion rate of sacrificial concrete, impinged by prototypic melt jet. In validation of numerical modeling, the time-dependent erosion depth and erosion configuration matched well with the experimental data. Sensitivity study of sacrificial concrete erosion indicates that the crust and ablated concrete layer presented at UO{sub 2}-ZrO{sub 2} melt and concrete interface, whereas no crust could be found in the interaction of Fe-Zr melt with concrete. The crust went through stabilization-fracture-reformation periodic process, accompanied with accumulating and collapsing of molten concrete layer. The concrete surface temperature fluctuated around a low temperature and ablation temperature. It increased as the concrete surface layer was heated to melting, and dropped down when the cold concrete was revealed. The erosion progression was fast in the conditions of small jet diameter and large concrete inclination angle, and it was significantly faster in the erosion by metallic melt jet than by oxidic melt jet.

  3. In vitro induction of alkaline phosphatase levels predicts in vivo bone forming capacity of human bone marrow stromal cells

    Directory of Open Access Journals (Sweden)

    Henk-Jan Prins

    2014-03-01

    Full Text Available One of the applications of bone marrow stromal cells (BMSCs that are produced by ex vivo expansion is for use in in vivo bone tissue engineering. Cultured stromal cells are a mixture of cells at different stages of commitment and expansion capability, leading to a heterogeneous cell population that each time can differ in the potential to form in vivo bone. A parameter that predicts for in vivo bone forming capacity is thus far lacking. We employed single colony-derived BMSC cultures to identify such predictive parameters. Using limiting dilution, we have produced sixteen single CFU-F derived BMSC cultures from human bone marrow and found that only five of these formed bone in vivo. The single colony-derived BMSC strains were tested for proliferation, osteogenic-, adipogenic- and chondrogenic differentiation capacity and the expression of a variety of associated markers. The only robust predictors of in vivo bone forming capacity were the induction of alkaline phosphatase, (ALP mRNA levels and ALP activity during in vitro osteogenic differentiation. The predictive value of in vitro ALP induction was confirmed by analyzing “bulk-cultured” BMSCs from various bone marrow biopsies. Our findings show that in BMSCs, the additional increase in ALP levels over basal levels during in vitro osteogenic differentiation is predictive of in vivo performance.

  4. Developing relations between soil erodibilty factors in two different soil erosion prediction models (USLE/RUSLE and wWEPP) and fludization bed technique for mechanical soil cohesion

    Science.gov (United States)

    Soil erosion models are valuable analysis tools that scientists and engineers use to examine observed data sets and predict the effects of possible future soil loss. In the area of water erosion, a variety of modeling technologies are available, ranging from solely qualitative models, to merely quan...

  5. Runoff erosion

    OpenAIRE

    Evelpidou, Niki (Ed.); Cordier, Stephane (Ed.); Merino, Agustin (Ed.); Figueiredo, Tomás de (Ed.); Centeri, Csaba (Ed.)

    2013-01-01

    Table of Contents PART I – THEORY OF RUNOFF EROSION CHAPTER 1 - RUNOFF EROSION – THE MECHANISMS CHAPTER 2 - LARGE SCALE APPROACHES OF RUNOFF EROSION CHAPTER 3 - MEASURING PRESENT RUNOFF EROSION CHAPTER 4 - MODELLING RUNOFF EROSION CHAPTER 5 - RUNOFF EROSION AND HUMAN SOCIETIES: THE INFLUENCE OF LAND USE AND MANAGEMENT PRACTICES ON SOIL EROSION PART II - CASE STUDIES CASE STUDIES – INTRODUCTION: RUNOFF EROSION IN MEDITERRANEAN AREA CASE STUDY 1: Soil Erosion Risk...

  6. Altered composition of bone as triggered by irradiation facilitates the rapid erosion of the matrix by both cellular and physicochemical processes.

    Directory of Open Access Journals (Sweden)

    Danielle E Green

    Full Text Available Radiation rapidly undermines trabecular architecture, a destructive process which proceeds despite a devastated cell population. In addition to the 'biologically orchestrated' resorption of the matrix by osteoclasts, physicochemical processes enabled by a damaged matrix may contribute to the rapid erosion of bone quality. 8w male C57BL/6 mice exposed to 5 Gy of Cs(137 γ-irradiation were compared to age-matched control at 2d, 10d, or 8w following exposure. By 10d, irradiation had led to significant loss of trabecular bone volume fraction. Assessed by reflection-based Fourier transform infrared imaging (FTIRI, chemical composition of the irradiated matrix indicated that mineralization had diminished at 2d by -4.3±4.8%, and at 10d by -5.8±3.2%. These data suggest that irradiation facilitates the dissolution of the matrix through a change in the material itself, a conclusion supported by a 13.7±4.5% increase in the elastic modulus as measured by nanoindentation. The decline in viable cells within the marrow of irradiated mice at 2d implies that the immediate collapse of bone quality and inherent increased risk of fracture is not solely a result of an overly-active biologic process, but one fostered by alterations in the material matrix that predisposes the material to erosion.

  7. Erosion corrosion in power plant piping systems - Calculation code for predicting wall thinning

    International Nuclear Information System (INIS)

    Kastner, W.; Erve, M.; Henzel, N.; Stellwag, B.

    1990-01-01

    Extensive experimental and theoretical investigations have been performed to develop a calculation code for wall thinning due to erosion corrosion in power plant piping systems. The so-called WATHEC code can be applied to single-phase water flow as well as to two-phase water/steam flow. Only input data which are available to the operator of the plant are taken into consideration. Together with a continuously updated erosion corrosion data base the calculation code forms one element of a weak point analysis for power plant piping systems which can be applied to minimize material loss due to erosion corrosion, reduce non-destructive testing and curtail monitoring programs for piping systems, recommend life-extending measures. (author). 12 refs, 17 figs

  8. Computer-aided and manual quantifications of MRI synovitis, bone marrow edema-like lesions, erosion and cartilage loss in rheumatoid arthritis of the wrist

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Haitao [The First Affiliated Hospital of Chongqing Medical University, Department of Radiology, Chongqing (China); University of California, San Francisco (UCSF), Department of Radiology and Biomedical Imaging, San Francisco, CA (United States); Rivoire, Julien; Hoppe, Michael; Link, Thomas M.; Li, Xiaojuan [University of California, San Francisco (UCSF), Department of Radiology and Biomedical Imaging, San Francisco, CA (United States); Srikhum, Waraporn [University of California, San Francisco (UCSF), Department of Radiology and Biomedical Imaging, San Francisco, CA (United States); Thammasat University, Department of Radiology, Pathumthani (Thailand); Imboden, John [San Francisco General Hospital, University of California, Department of Medicine, San Francisco and Division of Rheumatology, San Francisco, CA (United States)

    2014-12-10

    To investigate the reliability and validity of computer-aided automated and manual quantification as well as semiquantitative analysis for MRI synovitis, bone marrow edema-like lesions, erosion and cartilage loss of the wrist in rheumatoid arthritis (RA) compared to the OMERACT-RAMRIS. Wrist MRI was performed at 3 T in 16 patients with RA. Synovial volume and perfusion, bone marrow edema-like lesion (BMEL) volume, signal intensity and perfusion, and erosion dimensions were measured manually and using an in-house-developed automated software algorithm; findings were correlated with the OMERAC-RAMRIS gradings. In addition, a semiquantitative MRI cartilage loss score system was developed. Intraclass correlation coefficients (ICCs) were used to test the reproducibility of these quantitative and semiquantitative techniques. Spearman correlation coefficients were calculated between lesion quantifications and RAMRIS and between the MRI cartilage score and radiographic Sharp van der Heijde joint space narrowing scores. The intra- and interobserver ICCs were excellent for synovial, BMEL and erosion quantifications and cartilage loss grading (all >0.89). The synovial volume, BMEL volume and signal intensity, and erosion dimensions were significantly correlated with the corresponding RAMRIS (r = 0.727 to 0.900, p < 0.05). Synovial perfusion parameter maximum enhancement (Emax) was significantly correlated with synovitis RAMRIS (r = 0.798). BMEL perfusion parameters were not correlated with the RAMRIS BME score. Cartilage loss gradings from MRI were significantly correlated with the Sharp joint space narrowing scores (r = 0.635, p = 0.008). The computer-aided, manual and semiquantitative methods presented in this study can be used to evaluate MRI pathologies in RA with excellent reproducibility. Significant correlations with standard RAMRIS were found in the measurements using these methods. (orig.)

  9. A critical discussion on the applicability of Compound Topographic Index (CTI) for predicting ephemeral gully erosion

    Science.gov (United States)

    Casalí, Javier; Chahor, Youssef; Giménez, Rafael; Campo-Bescós, Miguel

    2016-04-01

    The so-called Compound Topographic Index (CTI) can be calculated for each grid cell in a DEM and be used to identify potential locations for ephemeral gullies (e. g.) based on land topography (CTI = A.S.PLANC, where A is upstream drainage area, S is local slope and PLANC is planform curvature, a measure of the landscape convergence) (Parker et al., 2007). It can be shown that CTI represents stream power per unit bed area and it considers the major parameters controlling the pattern and intensity of concentrated surface runoff in the field (Parker et al., 2007). However, other key variables controlling e.g. erosion (e. g. e.) such as soil characteristics, land-use and management, are not had into consideration. The critical CTI value (CTIc) "represents the intensity of concentrated overland flow necessary to initiate erosion and channelised flow under a given set of circumstances" (Parker et al., 2007). AnnAGNPS (Annualized Agriculture Non-Point Source) pollution model is an important management tool developed by (USDA) and uses CTI to locate potential ephemeral gullies. Then, and depending on rainfall characteristics of the period simulated by AnnAGNPS, potential e. g. can become "actual", and be simulated by the model accordingly. This paper presents preliminary results and a number of considerations after evaluating the CTI tool in Navarre. CTIc values found are similar to those cited by other authors, and the e. g. networks that on average occur in the area have been located reasonably well. After our experience we believe that it is necessary to distinguish between the CTIc corresponding to the location of headcuts whose migrations originate the e. g. (CTIc1); and the CTIc necessary to represent the location of the gully networks in the watershed (CTIc2), where gully headcuts are located in the upstream end of the gullies. Most scientists only consider one CTIc value, although, from our point of view, the two situations are different. CTIc1 would represent the

  10. Synthesising empirical results to improve predictions of post-wildfire runoff and erosion response

    Science.gov (United States)

    Richard A. Shakesby; John A. Moody; Deborah A. Martin; Pete Robichaud

    2016-01-01

    Advances in research into wildfire impacts on runoff and erosion have demonstrated increasing complexity of controlling factors and responses, which, combined with changing fire frequency, present challenges for modellers. We convened a conference attended by experts and practitioners in post-wildfire impacts, meteorology and related research, including...

  11. Predicting soil erosion using Rusle and NDVI time series from TM Landsat 5

    Directory of Open Access Journals (Sweden)

    Daniel Fonseca de Carvalho

    2014-03-01

    Full Text Available The objective of this work was to evaluate the seasonal variation of soil cover and rainfall erosivity, and their influences on the revised universal soil loss equation (Rusle, in order to estimate watershed soil losses in a temporal scale. Twenty-two TM Landsat 5 images from 1986 to 2009 were used to estimate soil use and management factor (C factor. A corresponding rainfall erosivity factor (R factor was considered for each image, and the other factors were obtained using the standard Rusle method. Estimated soil losses were grouped into classes and ranged from 0.13 Mg ha-1 on May 24, 2009 (dry season to 62.0 Mg ha-1 on March 11, 2007 (rainy season. In these dates, maximum losses in the watershed were 2.2 and 781.5 Mg ha-1 , respectively. Mean annual soil loss in the watershed was 109.5 Mg ha-1 , but the central area, with a loss of nearly 300.0 Mg ha-1 , was characterized as a site of high water-erosion risk. The use of C factor obtained from remote sensing data, associated to corresponding R factor, was fundamental to evaluate the soil erosion estimated by the Rusle in different seasons, unlike of other studies which keep these factors constant throughout time.

  12. Cement stress predictions after anatomic total shoulder arthroplasty are correlated with preoperative glenoid bone quality.

    Science.gov (United States)

    Terrier, Alexandre; Obrist, Raphaël; Becce, Fabio; Farron, Alain

    2017-09-01

    We hypothesized that biomechanical parameters typically associated with glenoid implant failure after anatomic total shoulder arthroplasty (aTSA) would be correlated with preoperative glenoid bone quality. We developed an objective automated method to quantify preoperative glenoid bone quality in different volumes of interest (VOIs): cortical bone, subchondral cortical plate, subchondral bone after reaming, subchondral trabecular bone, and successive layers of trabecular bone. Average computed tomography (CT) numbers (in Hounsfield units [HU]) were measured in each VOI from preoperative CT scans. In parallel, we built patient-specific finite element models of simulated aTSAs to predict cement stress, bone-cement interfacial stress, and bone strain around the glenoid implant. CT measurements and finite element predictions were obtained for 20 patients undergoing aTSA for primary glenohumeral osteoarthritis. We tested all linear correlations between preoperative patient characteristics (age, sex, height, weight, glenoid bone quality) and biomechanical predictions (cement stress, bone-cement interfacial stress, bone strain). Average CT numbers gradually decreased from cortical (717 HU) to subchondral and trabecular (362 HU) bone. Peak cement stress (4-10 MPa) was located within the keel hole, above the keel, or behind the glenoid implant backside. Cement stress, bone-cement interfacial stress, and bone strain were strongly negatively correlated with preoperative glenoid bone quality, particularly in VOIs behind the implant backside (subchondral trabecular bone) but also in deeper trabecular VOIs. Our numerical study suggests that preoperative glenoid bone quality is an important parameter to consider in aTSA, which may be associated with aseptic loosening of the glenoid implant. These initial results should now be confronted with clinical and radiologic outcomes. Copyright © 2017 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Elsevier Inc

  13. Development of a catchment/landscape erosion prediction model (MINErosion 4) for post-mining landscapes in Central Queensland, Australia.

    Science.gov (United States)

    Khalifa, Ashraf; Yu, Bofu; Ghadiri, Hossain; Carroll, Chris; So, Hwat-Bing

    2010-05-01

    industry further require a tool that enables them to predict and manage the impact of on-site and offsite discharges from storm events and to identify the areas of high erosion risk. Work is in progress to develop a user friendly package MINErosion 4 by combining the hillslope model MINErosion 3 with ARC-GIS 9, which allows the prediction of sediment losses and deposition from proposed post-mining landscapes (designed based on criteria derived from MINErosion3) subjected to rainstorms with known recurrence intervals for selected locations. An option is provided to derive mean annual soil loss from these catchments and landscapes. Soil samples were collected from various locations on 6 minesites to provide a measure of variability in erodibilities across a minesite. The model was validated against 9 years of catchment data collected from previous projects and the agreement between predicted (Y) and measured (X) soil losses are good with regression equations of Y = 0.919 X (R2 = 0.81) for individual rainstorms, and Y= 1.473 X (R2 = 0.726) for average annual soil loss.

  14. Lumbar bone mass predicts low back pain in males

    NARCIS (Netherlands)

    Hoozemans, M.J.M.; Koppes, L.L.J.; Twisk, J.W.R.; Dieën, J.H. van

    2012-01-01

    STUDY DESIGN.: Longitudinal study of lumbar bone mass as predictor of low back pain (LBP). OBJECTIVE.: To investigate whether low bone mineral content (BMC) and bone mineral density (BMD) values at the age of 36 years are associated with the prevalence of LBP at the age of 42 years among the study

  15. Upper Gastrointestinal Symptoms Predictive of Candida Esophagitis and Erosive Esophagitis in HIV and Non-HIV Patients

    Science.gov (United States)

    Takahashi, Yuta; Nagata, Naoyoshi; Shimbo, Takuro; Nishijima, Takeshi; Watanabe, Koji; Aoki, Tomonori; Sekine, Katsunori; Okubo, Hidetaka; Watanabe, Kazuhiro; Sakurai, Toshiyuki; Yokoi, Chizu; Mimori, Akio; Oka, Shinichi; Uemura, Naomi; Akiyama, Junichi

    2015-01-01

    Abstract Upper gastrointestinal (GI) symptoms are common in both HIV and non-HIV-infected patients, but the difference of GI symptom severity between 2 groups remains unknown. Candida esophagitis and erosive esophagitis, 2 major types of esophagitis, are seen in both HIV and non-HIV-infected patients, but differences in GI symptoms that are predictive of esophagitis between 2 groups remain unknown. We aimed to determine whether GI symptoms differ between HIV-infected and non-HIV-infected patients, and identify specific symptoms of candida esophagitis and erosive esophagitis between 2 groups. We prospectively enrolled 6011 patients (HIV, 430; non-HIV, 5581) who underwent endoscopy and completed questionnaires. Nine upper GI symptoms (epigastric pain, heartburn, acid regurgitation, hunger cramps, nausea, early satiety, belching, dysphagia, and odynophagia) were evaluated using a 7-point Likert scale. Associations between esophagitis and symptoms were analyzed by the multivariate logistic regression model adjusted for age, sex, and proton pump inhibitors. Endoscopy revealed GI-organic diseases in 33.4% (2010/6.011) of patients. The prevalence of candida esophagitis and erosive esophagitis was 11.2% and 12.1% in HIV-infected patients, respectively, whereas it was 2.9% and 10.7 % in non-HIV-infected patients, respectively. After excluding GI-organic diseases, HIV-infected patients had significantly (P symptom scores for heartburn, hunger cramps, nausea, early satiety, belching, dysphagia, and odynophagia than non-HIV-infected patients. In HIV-infected patients, any symptom was not significantly associated with CD4 cell count. In multivariate analysis, none of the 9 GI symptoms were associated with candida esophagitis in HIV-infected patients, whereas dysphagia and odynophagia were independently (P HIV-infected patients. However, heartburn and acid regurgitation were independently (P symptom scores were reliable in both HIV (α, 0.86) and non-HIV-infected patients

  16. NASA's Evolutionary Xenon Thruster (NEXT) Project Qualification Propellant Throughput Milestone: Performance, Erosion, and Thruster Service Life Prediction After 450 kg

    Science.gov (United States)

    Herman, Daniel A.

    2010-01-01

    The NASA s Evolutionary Xenon Thruster (NEXT) program is tasked with significantly improving and extending the capabilities of current state-of-the-art NSTAR thruster. The service life capability of the NEXT ion thruster is being assessed by thruster wear test and life-modeling of critical thruster components, such as the ion optics and cathodes. The NEXT Long-Duration Test (LDT) was initiated to validate and qualify the NEXT thruster propellant throughput capability. The NEXT thruster completed the primary goal of the LDT; namely to demonstrate the project qualification throughput of 450 kg by the end of calendar year 2009. The NEXT LDT has demonstrated 28,500 hr of operation and processed 466 kg of xenon throughput--more than double the throughput demonstrated by the NSTAR flight-spare. Thruster performance changes have been consistent with a priori predictions. Thruster erosion has been minimal and consistent with the thruster service life assessment, which predicts the first failure mode at greater than 750 kg throughput. The life-limiting failure mode for NEXT is predicted to be loss of structural integrity of the accelerator grid due to erosion by charge-exchange ions.

  17. A GIS-model for predicting the impact of climate change on shore erosion in hydroelectric reservoirs

    International Nuclear Information System (INIS)

    Penner, L.A.; Zimmer, T.A.M.; St Laurent, M.

    2008-01-01

    Shoreline erosion affects inland lakes and hydroelectric reservoirs in several ways. This poster described a vector-based geographic information system (GIS) model designed to predict changes in shore zone geometry, top-of-bluff recession, and eroded sediment volumes. The model was designed for use in Manitoba Hydro's reservoirs in northern Manitoba, and simulated near-shore downcutting and bank recession caused by wind-generated waves. Parameters for the model included deep water wave energy, and water level fluctuations. Effective wave energy was seen as a function of the water level fluctuation range, wave conditions, and near-shore slope. The model was validated by field monitoring studies that included repeated shore zone transect surveys and sediment coring studies. Results of the study showed that the model provides a systematic method of predicting potential changes in erosion associated with climatic change. The volume and mass of eroded sediment predicted for the different modelling scenarios will be used as input data for future sedimentation models. tabs., figs

  18. Bone mineral density before and after OLT: long-term follow-up and predictive factors.

    Science.gov (United States)

    Guichelaar, Maureen M J; Kendall, Rebecca; Malinchoc, Michael; Hay, J Eileen

    2006-09-01

    Fracturing after liver transplantation (OLT) occurs due to the combination of preexisting low bone mineral density (BMD) and early posttransplant bone loss, the risk factors for which are poorly defined. The prevalence and predictive factors for hepatic osteopenia and osteoporosis, posttransplant bone loss, and subsequent bone gain were studied by the long-term posttransplant follow-up of 360 consecutive adult patients with end-stage primary biliary cirrhosis (PBC) and primary sclerosing cholangitis (PSC). Only 20% of patients with advanced PBC or PSC have normal bone mass. Risk factors for low spinal BMD are low body mass index, older age, postmenopausal status, muscle wasting, high alkaline phosphatase and low serum albumin. A high rate of spinal bone loss occurred in the first 4 posttransplant months (annual rate of 16%) especially in those with younger age, PSC, higher pretransplant bone density, no inflammatory bowel disease, shorter duration of liver disease, current smoking, and ongoing cholestasis at 4 months. Factors favoring spinal bone gain from 4 to 24 months after transplantation were lower baseline and/or 4-month bone density, premenopausal status, lower cumulative glucocorticoids, no ongoing cholestasis, and higher levels of vitamin D and parathyroid hormone. Bone mass therefore improves most in patients with lowest pretransplant BMD who undergo successful transplantation with normal hepatic function and improved gonadal and nutritional status. Patients transplanted most recently have improved bone mass before OLT, and although bone loss still occurs early after OLT, these patients also have a greater recovery in BMD over the years following OLT.

  19. PREDICTION OF THE DURATION OF DISTRACTION REGENERATED BONE MATURATION

    Directory of Open Access Journals (Sweden)

    N. V. Tushina

    2012-01-01

    Full Text Available Aim of the study the characteristics of changes of serum biochemical parameters in dogs with delayed maturation of the distraction regenerate after surgical lengthening the leg bones by Ilizarov. The comparative analysis of biochemical changes in blood serum of animals with delayed regenerated bone osteogenesis after surgical leg bone lengthening according to Ilizarov has been made in the work. The development of persistent and marked hypocalcemia, significant accumulation of blood serum nonoxidized degradation products during limb bone surgical lengthening according to Ilizarov have been revealed to be adverse signs evidencing of the high probability of the disorder of further formation of the regenerated bone and its subsequent maturation at the stage of fixation.

  20. Formation of Valley Networks in a Cold and Icy Early Mars Climate: Predictions for Erosion Rates and Channel Morphology

    Science.gov (United States)

    Cassanelli, J.

    2017-12-01

    Mars is host to a diverse array of valley networks, systems of linear-to-sinuous depressions which are widely distributed across the surface and which exhibit branching patterns similar to the dendritic drainage patterns of terrestrial fluvial systems. Characteristics of the valley networks are indicative of an origin by fluvial activity, providing among the most compelling evidence for the past presence of flowing liquid water on the surface of Mars. Stratigraphic and crater age dating techniques suggest that the formation of the valley networks occurred predominantly during the early geologic history of Mars ( 3.7 Ga). However, whether the valley networks formed predominantly by rainfall in a relatively warm and wet early Mars climate, or by snowmelt and episodic rainfall in an ambient cold and icy climate, remains disputed. Understanding the formative environment of the valley networks will help distinguish between these warm and cold end-member early Mars climate models. Here we test a conceptual model for channel incision and evolution under cold and icy conditions with a substrate characterized by the presence of an ice-free dry active layer and subjacent ice-cemented regolith, similar to that found in the Antarctic McMurdo Dry Valleys. We implement numerical thermal models, quantitative erosion and transport estimates, and morphometric analyses in order to outline predictions for (1) the precise nature and structure of the substrate, (2) fluvial erosion/incision rates, and (3) channel morphology. Model predictions are compared against morphologic and morphometric observational data to evaluate consistency with the assumed cold climate scenario. In the cold climate scenario, the substrate is predicted to be characterized by a kilometers-thick globally-continuous cryosphere below a 50-100 meter thick desiccated ice-free zone. Initial results suggest that, with the predicted substrate structure, fluvial channel erosion and morphology in a cold early Mars

  1. Calculation Methods of Topographic Factors Modification Using Data Digital Elevation Model (DEM To Predict Erosion

    Directory of Open Access Journals (Sweden)

    Hengki Simanjuntak

    2018-03-01

    Full Text Available Erosion  is a crucial information for sustainable management of land resources within a particular watershed. The information of erosion is needed for land resource management planning, and is generally counted by USLE (Universal Soil Loss Equation. One of the parameters in USLE is topographic factor (LS. The determinations of LS in erosion estimation model are vary, both in terms of LS factor equation, as well as in terms of the length of the slope (λ and slope (s measurements. There are at least 3 methods used to calculate slope factors in spatial operation, i.e (1 Input of the LS Value from Table (INT, (2 Flow accumulation, and (3 Cell Size. The study was designed to obtain a method of calculation that gives the smallest topographic factor and in order to obtain a LS factors that similar to the slope information. Research location in Kampa Sub watershed, The LS determination in Kampa Sub watershed basically are with (INT and without calculating λ and s. INT method is determination without calculating λ and s, LS value is generate from the contour map and DEM SRTM by giving LS value from table reference of LS value. The Flow Accumulation and Cell Size are determination of LS Value by calculating λ and s. The Flow Accumulation method modifies the determination of λ and s using the middle value of s, λ per land use, and λ and s per cell. Cell Size method determines λ using the amount of cell size. The results showed that the “cell size” and "INT" methods were the best method for topographic factor (LS calculation, because LS value of “cell size” and "INT" methods are smaller than the flow accumulation method and the LS value similar to the slope information. LS value from that methods generated weighted value in average of 0,55−0,58. Keywords: cell size, flow accumulation, flow direction, the length of the slope, USLE

  2. Predicting the Rate of River Bank Erosion Caused by Large Wood Log

    Science.gov (United States)

    Zhang, N.; Rutherfurd, I.; Ghisalberti, M.

    2016-12-01

    When a single tree falls into a river channel, flow is deflected and accelerated between the tree roots and the bank face, increasing shear stress and scouring the bank. The scallop shaped erosion increases the diversity of the channel morphology, but also causes concern for adjacent landholders. Concern about increased bank erosion is one of the main reasons for large wood to still be removed from channels in SE Australia. Further, the hydraulic effect of many logs in the channel can reduce overall bank erosion rates. Although both phenomena have been described before, this research develops a hydraulic model that estimates their magnitude, and tests and calibrates this model with flume and field measurements, with logs with various configurations and sizes. Specifically, the model estimates the change in excess shear stress on the bank associated . The model addresses the effect of the log angle, distance from bank, and log size and flow condition by solving the mass continuity and energy conservation between the cross section at the approaching flow and contracted flow. Then, we evaluate our model against flume experiment preformed with semi-realistic log models to represent logs in different sizes and decay stages by comparing the measured and simulated velocity increase in the gap between the log and the bank. The log angle, distance from bank, and flow condition are systemically varied for each log model during the experiment. Final, the calibrated model is compared with the field data collected in anabranching channels of Murray River in SE Australia where there are abundant instream logs and regulated and consistent high flow for irrigation. Preliminary results suggest that a log can significantly increase the shear stress on the bank, especially when it positions perpendicular to the flow. The shear stress increases with the log angle in a rising curve (The log angle is the angle between log trunk and flow direction. 0o means log is parallel to flow with

  3. Are bone turnover markers capable of predicting callus consolidation during bone healing?

    Science.gov (United States)

    Klein, P; Bail, H J; Schell, H; Michel, R; Amthauer, H; Bragulla, H; Duda, G N

    2004-07-01

    The aim of this study was to determine the ability of the following bone turnover markers to monitor the course of callus consolidation during bone healing: Carboxy-terminal propeptide of procollagen type I (PICP), skeletal alkaline phosphatase (sALP), and amino-terminal propeptide of type III procollagen (PIlINP). Since interfragmentary movements have been proven to possess the ability to document the progression of bone healing in experimental studies, correlations between bone turnover markers and interfragmentary movements in vivo were investigated. Therefore, two different types of osteosyntheses representing different mechanical situations at the fracture site were compared in an ovine osteotomy model. Blood samples were taken preoperatively and postoperatively in weekly intervals over a nine-week healing period. At the same intervals, interfragmentary movements were measured in all sheep. After nine weeks, animals were sacrificed and the tibiae were evaluated both mechanically and histologically. Wide interindividual ranges were observed for all bone turnover markers. The systemic PICP level did not increase with callus consolidation. The bone-healing model seemed to influence the systemic level of PIIINP and sALP but no general correlation between bone turnover markers and interfragmentary movements could be detected. No differences between the different types of osteosyntheses and thus the different mechanical situations were observed. All analyzed markers failed as general predictors for the course of callus consolidation during bone healing.

  4. Serum bone alkaline phosphatase and calcaneus bone density predict fractures: a prospective study.

    Science.gov (United States)

    Ross, P D; Kress, B C; Parson, R E; Wasnich, R D; Armour, K A; Mizrahi, I A

    2000-01-01

    The aim of this study was to assess the ability of serum bone-specific alkaline phosphatase (bone ALP), creatinine-corrected urinary collagen crosslinks (CTx) and calcaneus bone mineral density (BMD) to identify postmenopausal women who have an increased risk of osteoporotic fractures. Calcaneus BMD and biochemical markers of bone turnover (serum bone ALP and urinary CTx) were measured in 512 community-dwelling postmenopausal women (mean age at baseline 69 years) participating in the Hawaii Osteoporosis Study. New spine and nonspine fractures subsequent to the BMD and biochemical bone markers measurements were recorded over an average of 2.7 years. Lateral spinal radiographs were used to identify spine fractures. Nonspine fractures were identified by self-report at the time of each examination. During the 2.7-year follow-up, at least one osteoporotic fracture occurred in 55 (10.7%) of the 512 women. Mean baseline serum bone ALP and urinary CTx were significantly higher among women who experienced an osteoporotic fracture compared with those women who did not fracture. In separate age-adjusted logistic regression models, serum bone ALP, urinary CTx and calcaneus BMD were each significantly associated with new fractures (odds ratios of 1.53, 1.54 and 1.61 per SD, respectively). Multiple variable logistic regression analysis identified BMD and serum bone ALP as significant predictors of fracture (p = 0.002 and 0.017, respectively). The results from this investigation indicate that increased bone turnover is significantly associated with an increased risk of osteoporotic fracture in postmenopausal women. This association is similar in magnitude and independent of that observed for BMD.

  5. Low bone mineral density in noncholestatic liver cirrhosis: prevalence, severity and prediction

    Directory of Open Access Journals (Sweden)

    Figueiredo Fátima Aparecida Ferreira

    2003-01-01

    Full Text Available BACKGROUND: Metabolic bone disease has long been associated with cholestatic disorders. However, data in noncholestatic cirrhosis are relatively scant. AIMS: To determine prevalence and severity of low bone mineral density in noncholestatic cirrhosis and to investigate whether age, gender, etiology, severity of underlying liver disease, and/or laboratory tests are predictive of the diagnosis. PATIENTS/METHODS: Between March and September/1998, 89 patients with noncholestatic cirrhosis and 20 healthy controls were enrolled in a cross-sectional study. All subjects underwent standard laboratory tests and bone densitometry at lumbar spine and femoral neck by dual X-ray absorptiometry. RESULTS: Bone mass was significantly reduced at both sites in patients compared to controls. The prevalence of low bone mineral density in noncholestatic cirrhosis, defined by the World Health Organization criteria, was 78% at lumbar spine and 71% at femoral neck. Bone density significantly decreased with age at both sites, especially in patients older than 50 years. Bone density was significantly lower in post-menopausal women patients compared to pre-menopausal and men at both sites. There was no significant difference in bone mineral density among noncholestatic etiologies. Lumbar spine bone density significantly decreased with the progression of liver dysfunction. No biochemical variable was significantly associated with low bone mineral density. CONCLUSIONS: Low bone mineral density is highly prevalent in patients with noncholestatic cirrhosis. Older patients, post-menopausal women and patients with severe hepatic dysfunction experienced more advanced bone disease. The laboratory tests routinely determined in patients with liver disease did not reliably predict low bone mineral density.

  6. Adapting SWAT hillslope erosion model to predict sediment concentrations and yields in large Basins.

    Science.gov (United States)

    Vigiak, Olga; Malagó, Anna; Bouraoui, Fayçal; Vanmaercke, Matthias; Poesen, Jean

    2015-12-15

    The Soil and Water Assessment Tool (SWAT) is used worldwide for water quality assessment and planning. This paper aimed to assess and adapt SWAT hillslope sediment yield model (Modified Universal Soil Loss Equation, MUSLE) for applications in large basins, i.e. when spatial data is coarse and model units are large; and to develop a robust sediment calibration method for large regions. The Upper Danube Basin (132,000km(2)) was used as case study representative of large European Basins. The MUSLE was modified to reduce sensitivity of sediment yields to the Hydrologic Response Unit (HRU) size, and to identify appropriate algorithms for estimating hillslope length (L) and slope-length factor (LS). HRUs gross erosion was broadly calibrated against plot data and soil erosion map estimates. Next, mean annual SWAT suspended sediment concentrations (SSC, mg/L) were calibrated and validated against SSC data at 55 gauging stations (622 station-years). SWAT annual specific sediment yields in subbasin reaches (RSSY, t/km(2)/year) were compared to yields measured at 33 gauging stations (87station-years). The best SWAT configuration combined a MUSLE equation modified by the introduction of a threshold area of 0.01km(2) where L and LS were estimated with flow accumulation algorithms. For this configuration, the SSC residual interquartile was less than +/-15mg/L both for the calibration (1995-2004) and the validation (2005-2009) periods. The mean SSC percent bias for 1995-2009 was 24%. RSSY residual interquartile was within +/-10t/km(2)/year, with a mean RSSY percent bias of 12%. Residuals showed no bias with respect to drainage area, slope, or spatial distribution. The use of multiple data types at multiple sites enabled robust simulation of sediment concentrations and yields of the region. The MUSLE modifications are recommended for use in large basins. Based on SWAT simulations, we present a sediment budget for the Upper Danube Basin. Copyright © 2015. Published by Elsevier B.V.

  7. Precision comparison of the erosion rates derived from 137Cs measurements models with predictions based on empirical relationship

    International Nuclear Information System (INIS)

    Yang Mingyi; Liu Puling; Li Liqing

    2004-01-01

    The soil samples were collected in 6 cultivated runoff plots with grid sampling method, and the soil erosion rates derived from 137 Cs measurements were calculated. The models precision of Zhang Xinbao, Zhou Weizhi, Yang Hao and Walling were compared with predictions based on empirical relationship, data showed that the precision of 4 models is high within 50m slope length except for the slope with low slope angle and short length. Relatively, the precision of Walling's model is better than that of Zhang Xinbao, Zhou Weizhi and Yang Hao. In addition, the relationship between parameter Γ in Walling's improved model and slope angle was analyzed, the ralation is: Y=0.0109 X 1.0072 . (authors)

  8. Rill erosion rates in burned forests

    Science.gov (United States)

    Joseph W. Wagenbrenner; Peter R. Robichaud

    2011-01-01

    Introduction Wildfires often produce large increases in runoff and erosion rates (e.g., Moody and Martin, 2009), and land managers need to predict the frequency and magnitude of postfire erosion to determine the needs for hazard response and possible erosion mitigation to reduce the impacts of increased erosion on public safety and valued resources. The Water Erosion...

  9. Evaluation of the rusle and disturbed wepp erosion models for predicting soil loss in the first year after wildfire in NW Spain.

    Science.gov (United States)

    Fernández, Cristina; Vega, José A

    2018-05-04

    Severe fire greatly increases soil erosion rates and overland-flow in forest land. Soil erosion prediction models are essential for estimating fire impacts and planning post-fire emergency responses. We evaluated the performance of a) the Revised Universal Soil Loss Equation (RUSLE), modified by inclusion of an alternative equation for the soil erodibility factor, and b) the Disturbed WEPP model, by comparing the soil loss predicted by the models and the soil loss measured in the first year after wildfire in 44 experimental field plots in NW Spain. The Disturbed WEPP has not previously been validated with field data for use in NW Spain; validation studies are also very scarce in other areas. We found that both models underestimated the erosion rates. The accuracy of the RUSLE model was low, even after inclusion of a modified soil erodibility factor accounting for high contents of soil organic matter. We conclude that neither model is suitable for predicting soil erosion in the first year after fire in NW Spain and suggest that soil burn severity should be given greater weighting in post-fire soil erosion modelling. Copyright © 2018 Elsevier Inc. All rights reserved.

  10. Erosion and erosion-corrosion

    International Nuclear Information System (INIS)

    Isomoto, Yoshinori

    2008-01-01

    It is very difficult to interpret the technical term of erosion-corrosion' which is sometimes encountered in piping systems of power plants, because of complicated mechanisms and several confusing definitions of erosion-corrosion phenomena. 'FAC (flow accelerated corrosion)' is recently introduced as wall thinning of materials in power plant systems, as a representative of 'erosion-corrosion'. FAC is, however, not necessarily well understood and compared with erosion-corrosion. This paper describes firstly the origin, definition and fundamental understandings of erosion and erosion-corrosion, in order to reconsider and reconfirm the phenomena of erosion, erosion-corrosion and FAC. Next, typical mapping of erosion, corrosion, erosion-corrosion and FAC are introduced in flow velocity and environmental corrosiveness axes. The concept of damage rate in erosion-corrosion is finally discussed, connecting dissolution rate, mass transfer of metal ions in a metal oxide film and film growth. (author)

  11. Heartburn Severity Does Not Predict Disease Severity in Patients With Erosive Esophagitis

    Science.gov (United States)

    Fennerty, M. Brian; Johnson, David A.

    2006-01-01

    Background For patients with gastroesophageal reflux disease (GERD), it is often assumed by treating physicians that the severity of heartburn correlates with the severity of erosive esophagitis (EE). Objective This is a post hoc analysis of data from 5 clinical trials that investigate the relationship between the baseline severity of heartburn and the baseline severity of EE. Methods Patients with endoscopically confirmed EE were assessed for heartburn symptoms with a 4-point scale at baseline and during treatment for 8 weeks with various proton pump inhibitors in 5 double-blind trials in which esomeprazole was the common comparator. EE was graded with the Los Angeles (LA) classification system. In these trials, healing and symptom response were evaluated by endoscopy and questionnaire after 4 weeks of treatment. Patients who were not healed were treated for an additional 4 weeks and reevaluated. Results A total of 11,945 patients with endoscopically confirmed EE participated in the 5 trials, with patients receiving esomeprazole 40 mg (n = 5068), esomeprazole 20 mg (n = 1243), omeprazole 20 mg (n = 3018), or lansoprazole 30 mg (n = 2616). Approximately one quarter of the 11,945 GERD patients in these 5 trials had severe EE (defined as LA grades C or D), regardless of their baseline heartburn severity. Conclusion The severity of GERD symptoms does not correlate well with disease severity. These findings indicate that endoscopy may have value in GERD patients in identifying those with EE, and if empirical therapy is chosen, then longer courses (4-8 weeks) of antisecretory therapy may be necessary to ensure healing of unrecognized esophagitis. PMID:16926745

  12. Fuels planning: science synthesis and integration; environmental consequences fact sheet 12: Water Erosion Prediction Project (WEPP) Fuel Management (FuMe) tool

    Science.gov (United States)

    William Elliot; David Hall

    2005-01-01

    The Water Erosion Prediction Project (WEPP) Fuel Management (FuMe) tool was developed to estimate sediment generated by fuel management activities. WEPP FuMe estimates sediment generated for 12 fuel-related conditions from a single input. This fact sheet identifies the intended users and uses, required inputs, what the model does, and tells the user how to obtain the...

  13. Predicting local distributions of erosion-corrosion wear sites for the piping in the nuclear power plant using CFD models

    International Nuclear Information System (INIS)

    Ferng, Y.M.

    2008-01-01

    The erosion-corrosion (E/C) wear is an essential degradation mechanism for the piping in the nuclear power plant, which results in the oxide mass loss from the inside of piping, the wall thinning, and even the pipe break. The pipe break induced by the E/C wear may cause costly plant repairs and personal injures. The measurement of pipe wall thickness is a useful tool for the power plant to prevent this incident. In this paper, CFD models are proposed to predict the local distributions of E/C wear sites, which include both the two-phase hydrodynamic model and the E/C models. The impacts of centrifugal and gravitational forces on the liquid droplet behaviors within the piping can be reasonably captured by the two-phase model. Coupled with these calculated flow characteristics, the E/C models can predicted the wear site distributions that show satisfactory agreement with the plant measurements. Therefore, the models proposed herein can assist in the pipe wall monitoring program for the nuclear power plant by way of concentrating the measuring point on the possible sites of severe E/C wear for the piping and reducing the measurement labor works

  14. [Anti-erosion effect of hedgerows in hillside croplands of Danjiangkou based on the evaluation with water erosion prediction project (WEPP) model].

    Science.gov (United States)

    Xiong, Qin-xue; Liu, Zhang-yong; Yao, Gui-zhi; Li, Ben-zhou

    2010-09-01

    Based on the data of field experiments on the hillside croplands of Danjiangkou, Hubei Province of China, the input files of crop characters, management measures, slope gradient and length, and soil properties for running WEPP model (Hillslope version) were established. Combining with the local weather data, a simulation study with the model was made on the runoff and soil loss of the croplands protected by four kinds of hedgerows (Amorpha fruticosa, Lonicera japonica, Hemerocallis fulva, and Poa sphondylodes) in Danjiangkou area. The resulted showed that WEPP model could accurately simulate the anti-erosion effect of hedgerows in hillside farmlands in the study area. Using this model not only reduced test number, but also saved time and effort, being able to provide scientific basis for the popularization and application of hedgerows. Among the four hedgerows, Amorpha fruticosa had the best anti-erosion effect. According to the simulation, the optimal planting density of A. fruticosa hedgerows in the farmlands was 1 m x 15 m at slope gradient 5 degrees, 1 m x 10 m at slope gradient 15 degrees, and 1 m x 3 m at slope gradient 25 degrees.

  15. Use of Radiographic Densitometry to Predict the Bone Healing Index in Distraction Osteogenesis

    Directory of Open Access Journals (Sweden)

    A Saw

    2008-04-01

    Full Text Available Bone lengthening with distraction osteogenesis involves prolonged application of an external fixator frame. Qualitative and quantitative evaluation of callus has been described using various imaging modalities but there is no simple reliable and readily available method. This study aims to investigate the use of a densitometer to analyze plain radiographic images and correlate them with the rate of new bone formation as represented by the bone healing index. A total of 34 bone lengthening procedures in 29 patients were retrospectively reviewed. We used an X-Rite 301 densitometer to measure densities of new callus on plain radiographs taken at 4 and 8 weeks after surgery. Patients aged below 16y had significantly lower BHIs indicating faster bone healing and shorter duration of treatment. The ratio of radiographic densities between centre and edge of the new bone measured from plain radiographs taken at 8 weeks correlated positively with the eventual BHI of the patient. This method provides a simple and easy way to predict the rate of bone healing at an early stage of treatment and may also allow remedial action to be taken for those with poor progress in bone formation.

  16. Modeling soil erosion in a watershed

    OpenAIRE

    Lanuza, R.

    1999-01-01

    Most erosion models have been developed based on a plot scale and have limited application to a watershed due to the differences in aerial scale. In order to address this limitation, a GIS-assisted methodology for modeling soil erosion was developed using PCRaster to predict the rate of soil erosion at watershed level; identify the location of erosion prone areas; and analyze the impact of landuse changes on soil erosion. The general methodology of desktop modeling or soil erosion at watershe...

  17. Bone scintigraphy predicts the risk of spinal cord compression in hormone-refractory prostate cancer

    International Nuclear Information System (INIS)

    Soerdjbalie-Maikoe, Vidija; Pelger, Rob C.M.; Nijeholt, Guus A.B. Lycklama; Arndt, Jan-Willem; Zwinderman, Aeilko H.; Bril, Herman; Papapoulos, Socrates E.; Hamdy, Neveen A.T.

    2004-01-01

    In prostate cancer, confirmation of metastatic involvement of the skeleton has traditionally been achieved by bone scintigraphy, although the widespread availability of prostate-specific antigen (PSA) measurements has tended to eliminate the need for this investigation. The potential of bone scintigraphy to predict skeletal-related events, particularly spinal cord compression, after the onset of hormone refractoriness has never been investigated. The aim of this study was to establish whether a new method of evaluating bone scintigraphy would offer a better predictive value for this complication of the metastatic process than is achieved with currently available grading methods. We studied 84 patients with hormone-refractory prostate cancer who had undergone bone scintigraphy at the time of hormone escape. Tumour grading and parameters of tumour load (PSA and alkaline phosphatase activity) were available in all patients. The incidence of spinal cord compression was documented and all patients were followed up until death. Bone scintigraphy was evaluated by the conventional Soloway grading and by an additional analysis determining total or partial involvement of individual vertebrae. In contrast to the Soloway method, the new method was able to predict spinal cord compression at various spinal levels. Our data suggest that there is still a place for bone scintigraphy in the management of hormone-refractory prostate cancer. (orig.)

  18. Prediction of soil stability and erosion in semiarid regions using numerical hydrological model (MCAT) and airborne hyperspectral imagery

    Science.gov (United States)

    Brook, Anna; Wittenberg, Lea

    2015-04-01

    promising models is the MCAT, which is a MATLAB library of visual and numerical analysis tools for the evaluation of hydrological and environmental models. The model applied in this paper presents an innovative infrastructural system for predicting soil stability and erosion impacts. This integrated model is applicable to mixed areas with spatially varying soil properties, landscape, and land-cover characteristics. Data from a semiarid site in southern Israel was used to evaluate the model and analyze fundamental erosion mechanisms. The findings estimate the sensitivity of the suggested model to the physical parameters and encourage the use of hyperspectral remote sensing imagery (HSI). The proposed model is integrated according to the following stages: 1. The soil texture, aggregation, soil moisture estimated via airborne HSI data, including soil surface clay and calcium carbonate erosions; 2. The mechanical stability of soil assessed via pedo-transfer function corresponding to load dependent changes in soil physical properties due to pre-compression stress (set of equations study shear strength parameters take into account soil texture, aggregation, soil moisture and ecological soil variables); 3. The precipitation-related runoff model program (RMP) satisfactorily reproduces the observed seasonal mean and variation of surface runoff for the current climate simulation; 4. The Monte Carlo Analysis Toolbox (MCAT), a library of visual and numerical analysis tools for the evaluation of hydrological and environmental models, is proposed as a tool for integrate all the approaches to an applicable model. The presented model overcomes the limitations of existing modeling methods by integrating physical data produced via HSI and yet stays generic in terms of space and time independency.

  19. RANS Based Methodology for Predicting the Influence of Leading Edge Erosion on Airfoil Performance

    Energy Technology Data Exchange (ETDEWEB)

    Langel, Christopher M. [Univ. of California, Davis, CA (United States). Dept. of Mechanical and Aerospace Engineering; Chow, Raymond C. [Univ. of California, Davis, CA (United States). Dept. of Mechanical and Aerospace Engineering; van Dam, C. P. [Univ. of California, Davis, CA (United States). Dept. of Mechanical and Aerospace Engineering; Maniaci, David Charles [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States). Wind Energy Technologies Dept.

    2017-10-01

    The impact of surface roughness on flows over aerodynamically designed surfaces is of interested in a number of different fields. It has long been known the surface roughness will likely accelerate the laminar- turbulent transition process by creating additional disturbances in the boundary layer. However, there are very few tools available to predict the effects surface roughness will have on boundary layer flow. There are numerous implications of the premature appearance of a turbulent boundary layer. Increases in local skin friction, boundary layer thickness, and turbulent mixing can impact global flow properties compounding the effects of surface roughness. With this motivation, an investigation into the effects of surface roughness on boundary layer transition has been conducted. The effort involved both an extensive experimental campaign, and the development of a high fidelity roughness model implemented in a R ANS solver. Vast a mounts of experimental data was generated at the Texas A&M Oran W. Nicks Low Speed Wind Tunnel for the calibration and validation of the roughness model described in this work, as well as future efforts. The present work focuses on the development of the computational model including a description of the calibration process. The primary methodology presented introduces a scalar field variable and associated transport equation that interacts with a correlation based transition model. The additional equation allows for non-local effects of surface roughness to be accounted for downstream of rough wall sections while maintaining a "local" formulation. The scalar field is determined through a boundary condition function that has been calibrated to flat plate cases with sand grain roughness. The model was initially tested on a NACA 0012 airfoil with roughness strips applied to the leading edge. Further calibration of the roughness model was performed using results from the companion experimental study on a NACA 633 -418 airfoil

  20. On the prediction of threshold friction velocity of wind erosion using soil reflectance spectroscopy

    Science.gov (United States)

    Li, Junran; Flagg, Cody B.; Okin, Gregory S.; Painter, Thomas H.; Dintwe, Kebonye; Belnap, Jayne

    2015-01-01

    Current approaches to estimate threshold friction velocity (TFV) of soil particle movement, including both experimental and empirical methods, suffer from various disadvantages, and they are particularly not effective to estimate TFVs at regional to global scales. Reflectance spectroscopy has been widely used to obtain TFV-related soil properties (e.g., moisture, texture, crust, etc.), however, no studies have attempted to directly relate soil TFV to their spectral reflectance. The objective of this study was to investigate the relationship between soil TFV and soil reflectance in the visible and near infrared (VIS–NIR, 350–2500 nm) spectral region, and to identify the best range of wavelengths or combinations of wavelengths to predict TFV. Threshold friction velocity of 31 soils, along with their reflectance spectra and texture were measured in the Mojave Desert, California and Moab, Utah. A correlation analysis between TFV and soil reflectance identified a number of isolated, narrow spectral domains that largely fell into two spectral regions, the VIS area (400–700 nm) and the short-wavelength infrared (SWIR) area (1100–2500 nm). A partial least squares regression analysis (PLSR) confirmed the significant bands that were identified by correlation analysis. The PLSR further identified the strong relationship between the first-difference transformation and TFV at several narrow regions around 1400, 1900, and 2200 nm. The use of PLSR allowed us to identify a total of 17 key wavelengths in the investigated spectrum range, which may be used as the optimal spectral settings for estimating TFV in the laboratory and field, or mapping of TFV using airborne/satellite sensors.

  1. Using high-performance mathematical modelling tools to predict erosion and sediment fluxes in peri-urban catchments

    Science.gov (United States)

    Pereira, André; Conde, Daniel; Ferreira, Carla S. S.; Walsh, Rory; Ferreira, Rui M. L.

    2017-04-01

    Deforestation and urbanization generally lead to increased soil erosion andthrough the indirect effect of increased overland flow and peak flood discharges. Mathematical modelling tools can be helpful for predicting the spatial distribution of erosion and the morphological changes on the channel network. This is especially useful to predict the impacts of land-use changes in parts of the watershed, namely due to urbanization. However, given the size of the computational domain (normally the watershed itself), the need for high spatial resolution data to model accurately sediment transport processes and possible need to model transcritical flows, the computational cost is high and requires high-performance computing techniques. The aim of this work is to present the latest developments of the hydrodynamic and morphological model STAV2D and its applicability to predict runoff and erosion at watershed scale. STAV2D was developed at CEris - Instituto Superior Técnico, Universidade de Lisboa - as a tool particularly appropriated to model strong transient flows in complex and dynamic geometries. It is based on an explicit, first-order 2DH finite-volume discretization scheme for unstructured triangular meshes, in which a flux-splitting technique is paired with a reviewed Roe-Riemann solver, yielding a model applicable to discontinuous flows over time-evolving geometries. STAV2D features solid transport in both Euleran and Lagrangian forms, with the aim of describing the transport of fine natural sediments and then the large individual debris. The model has been validated with theoretical solutions and laboratory experiments (Canelas et al., 2013 & Conde et al., 2015). STAV-2D now supports fully distributed and heterogeneous simulations where multiple different hardware devices can be used to accelerate computation time within a unified Object-Oriented approach: the source code for CPU and GPU has the same compilation units and requires no device specific branches, like

  2. Morphometric analysis - Cone beam computed tomography to predict bone quality and quantity.

    Science.gov (United States)

    Hohlweg-Majert, B; Metzger, M C; Kummer, T; Schulze, D

    2011-07-01

    Modified quantitative computed tomography is a method used to predict bone quality and quantify the bone mass of the jaw. The aim of this study was to determine whether bone quantity or quality was detected by cone beam computed tomography (CBCT) combined with image analysis. MATERIALS AND PROCEDURES: Different measurements recorded on two phantoms (Siemens phantom, Comac phantom) were evaluated on images taken with the Somatom VolumeZoom (Siemens Medical Solutions, Erlangen, Germany) and the NewTom 9000 (NIM s.r.l., Verona, Italy) in order to calculate a calibration curve. The spatial relationships of six sample cylinders and the repositioning from four pig skull halves relative to adjacent defined anatomical structures were assessed by means of three-dimensional visualization software. The calibration curves for computer tomography (CT) and cone beam computer tomography (CBCT) using the Siemens phantom showed linear correlation in both modalities between the Hounsfield Units (HU) and bone morphology. A correction factor for CBCT was calculated. Exact information about the micromorphology of the bone cylinders was only available using of micro computer tomography. Cone-beam computer tomography is a suitable choice for analysing bone mass, but, it does not give any information about bone quality. 2010 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved.

  3. Predicting the effectiveness of different mulching techniques in reducing post-fire runoff and erosion at plot scale with the RUSLE, MMF and PESERA models.

    Science.gov (United States)

    Vieira, D C S; Serpa, D; Nunes, J P C; Prats, S A; Neves, R; Keizer, J J

    2018-08-01

    Wildfires have become a recurrent threat for many Mediterranean forest ecosystems. The characteristics of the Mediterranean climate, with its warm and dry summers and mild and wet winters, make this a region prone to wildfire occurrence as well as to post-fire soil erosion. This threat is expected to be aggravated in the future due to climate change and land management practices and planning. The wide recognition of wildfires as a driver for runoff and erosion in burnt forest areas has created a strong demand for model-based tools for predicting the post-fire hydrological and erosion response and, in particular, for predicting the effectiveness of post-fire management operations to mitigate these responses. In this study, the effectiveness of two post-fire treatments (hydromulch and natural pine needle mulch) in reducing post-fire runoff and soil erosion was evaluated against control conditions (i.e. untreated conditions), at different spatial scales. The main objective of this study was to use field data to evaluate the ability of different erosion models: (i) empirical (RUSLE), (ii) semi-empirical (MMF), and (iii) physically-based (PESERA), to predict the hydrological and erosive response as well as the effectiveness of different mulching techniques in fire-affected areas. The results of this study showed that all three models were reasonably able to reproduce the hydrological and erosive processes occurring in burned forest areas. In addition, it was demonstrated that the models can be calibrated at a small spatial scale (0.5 m 2 ) but provide accurate results at greater spatial scales (10 m 2 ). From this work, the RUSLE model seems to be ideal for fast and simple applications (i.e. prioritization of areas-at-risk) mainly due to its simplicity and reduced data requirements. On the other hand, the more complex MMF and PESERA models would be valuable as a base of a possible tool for assessing the risk of water contamination in fire-affected water bodies and

  4. Predicting the effectiveness of different mulching techniques to reduce post-fire runoff and erosion in Mediterranean pine stands - does cover matter?

    Science.gov (United States)

    Vieira, Diana; Nunes, João; Prats, Sergio; Serpa, Dalila; Keizer, Jan

    2016-04-01

    Wildfires have become a recurrent threat for many forest ecosystems of the Mediterranean. The characteristics of the Mediterranean climate with its warm and dry summers and mild and wet winters make it prone to wildfire occurrence as well as to post-fire soil erosion. Furthermore, climate change and continuation of current land management practices and planning are generally expected to further increase this threat. The wide recognition of the effects of wildfires to enhance runoff and erosion has created a strong demand for model-based tools for predicting the post-fire hydrological and erosion response and, in particular, for predicting the effectiveness of post-fire forestry operations to mitigate these responses. Such a tool should allow to identify areas with elevated risks of soil erosion and to evaluate which measures should be applied and when to minimize these risks. A key element in evaluating these measures is also their costs, in order to optimize the use of the limited resources that are typically available for post-fire land management. In this study, two "treatments" are compared with control conditions (i.e. doing nothing) after a wildfire with a moderate soil burn severity: (i) 4 erosion plots were treated with hydro-mulch, (ii) 4 erosion plots were untreated but had a high pine needle cover quickly after the fire, due to needle cast from scorched pine crowns (often referred to as "natural mulching") (iii) 4 plots were untreated and had a very reduced protective litter cover . The main objective of this study was to asses if the revised MMF model could effectively predict the impacts of hydro-mulching and natural mulching with pine needle on runoff generation and the associated soil losses. If MMF could predict well the impact of natural mulching, it could be very useful in limiting the areas that should be considered for specific soil mitigation measures, especially in the case of wildfires that affect large areas with moderate severity. The

  5. Observations and predictions of wave runup, extreme water levels, and medium-term dune erosion during storm conditions

    OpenAIRE

    Suanez , Serge ,; Cancouët , Romain; Floc'h , France; Blaise , Emmanuel; Ardhuin , Fabrice; Filipot , Jean-François; Cariolet , Jean-Marie; Delacourt , Christophe

    2015-01-01

    Monitoring of dune erosion and accretion on the high-energy macrotidal Vougot beach in North Brittany (France) over the past decade (2004–2014) has revealed significant morphological changes. Dune toe erosion/accretion records have been compared with extreme water level measurements, defined as the sum of (i) astronomic tide; (ii) storm surge; and (iii) vertical wave runup. Runup parameterization was conducted using swash limits, beach profiles, and hydrodynamic (Hm0, Tm0,–1, and high tide wa...

  6. Prediction of autosomal STR typing success in ancient and Second World War bone samples.

    Science.gov (United States)

    Zupanič Pajnič, Irena; Zupanc, Tomaž; Balažic, Jože; Geršak, Živa Miriam; Stojković, Oliver; Skadrić, Ivan; Črešnar, Matija

    2017-03-01

    Human-specific quantitative PCR (qPCR) has been developed for forensic use in the last 10 years and is the preferred DNA quantification technique since it is very accurate, sensitive, objective, time-effective and automatable. The amount of information that can be gleaned from a single quantification reaction using commercially available quantification kits has increased from the quantity of nuclear DNA to the amount of male DNA, presence of inhibitors and, most recently, to the degree of DNA degradation. In skeletal remains samples from disaster victims, missing persons and war conflict victims, the DNA is usually degraded. Therefore the new commercial qPCR kits able to assess the degree of degradation are potentially able to predict the success of downstream short tandem repeat (STR) typing. The goal of this study was to verify the quantification step using the PowerQuant kit with regard to its suitability as a screening method for autosomal STR typing success on ancient and Second World War (WWII) skeletal remains. We analysed 60 skeletons excavated from five archaeological sites and four WWII mass graves from Slovenia. The bones were cleaned, surface contamination was removed and the bones ground to a powder. Genomic DNA was obtained from 0.5g of bone powder after total demineralization. The DNA was purified using a Biorobot EZ1 device. Following PowerQuant quantification, DNA samples were subjected to autosomal STR amplification using the NGM kit. Up to 2.51ng DNA/g of powder were extracted. No inhibition was detected in any of bones analysed. 82% of the WWII bones gave full profiles while 73% of the ancient bones gave profiles not suitable for interpretation. Four bone extracts yielded no detectable amplification or zero quantification results and no profiles were obtained from any of them. Full or useful partial profiles were produced only from bone extracts where short autosomal (Auto) and long degradation (Deg) PowerQuant targets were detected. It is

  7. Dendrobium moniliforme Exerts Inhibitory Effects on Both Receptor Activator of Nuclear Factor Kappa-B Ligand-Mediated Osteoclast Differentiation in Vitro and Lipopolysaccharide-Induced Bone Erosion in Vivo.

    Science.gov (United States)

    Baek, Jong Min; Kim, Ju-Young; Ahn, Sung-Jun; Cheon, Yoon-Hee; Yang, Miyoung; Oh, Jaemin; Choi, Min Kyu

    2016-03-01

    Dendrobium moniliforme (DM) is a well-known plant-derived extract that is widely used in Oriental medicine. DM and its chemical constituents have been reported to have a variety of pharmacological effects, including anti-oxidative, anti-inflammatory, and anti-tumor activities; however, no reports discuss the beneficial effects of DM on bone diseases such as osteoporosis. Thus, we investigated the relationship between DM and osteoclasts, cells that function in bone resorption. We found that DM significantly reduced receptor activator of nuclear factor kappa-B ligand (RANKL)-induced tartrate-resistant acid phosphatase (TRAP)-positive osteoclast formation; DM directly induced the down-regulation of c-Fos and nuclear factor of activated T cells c1 (NFATc1) without affecting other RANKL-dependent transduction pathways. In the later stages of osteoclast maturation, DM negatively regulated the organization of filamentous actin (F-actin), resulting in impaired bone-resorbing activity by the mature osteoclasts. In addition, micro-computed tomography (μ-CT) analysis of the murine model revealed that DM had a beneficial effect on lipopolysaccharide (LPS)-mediated bone erosion. Histological analysis showed that DM attenuated the degradation of trabecular bone matrix and formation of TRAP-positive osteoclasts in bone tissues. These results suggest that DM is a potential candidate for the treatment of metabolic bone disorders such as osteoporosis.

  8. Prediction of progression of radiographic knee osteoarthritis using tibial trabecular bone texture

    DEFF Research Database (Denmark)

    Woloszynski, T; Podsiadlo, P; Stachowiak, G W

    2012-01-01

    OBJECTIVE.: To develop a system for prediction of progression of radiographic knee osteoarthritis (OA) using tibial trabecular bone (TB) texture. METHODS.: We studied 203 knees with (n=68) or without (n=135) radiographic tibiofemoral OA in 105 subjects (90 men, 15 women, mean age 54 years) who ha...

  9. Outcome prediction in plasmacytoma of bone: a risk model utilizing bone marrow flow cytometry and light-chain analysis.

    Science.gov (United States)

    Hill, Quentin A; Rawstron, Andy C; de Tute, Ruth M; Owen, Roger G

    2014-08-21

    The purpose of this study was to use multiparameter flow cytometry to detect occult marrow disease (OMD) in patients with solitary plasmacytoma of bone and assess its value in predicting outcome. Aberrant phenotype plasma cells were demonstrable in 34 of 50 (68%) patients and comprised a median of 0.52% of bone marrow leukocytes. With a median follow-up of 3.7 years, 28 of 50 patients have progressed with a median time to progression (TTP) of 18 months. Progression was documented in 72% of patients with OMD vs 12.5% without (median TTP, 26 months vs not reached; P = .003). Monoclonal urinary light chains (ULC) were similarly predictive of outcome because progression was documented in 91% vs 44% without (median TTP, 16 vs 82 months; P < .001). By using both parameters, it was possible to define patients with an excellent outcome (lacking both OMD and ULC, 7.7% progression) and high-risk patients (OMD and/or ULC, 75% progression; P = .001). Trials of systemic therapy are warranted in high-risk patients. © 2014 by The American Society of Hematology.

  10. Predicting the impact of logging activities on soil erosion and water quality in steep, forested tropical islands

    Science.gov (United States)

    Wenger, Amelia S.; Atkinson, Scott; Santini, Talitha; Falinski, Kim; Hutley, Nicholas; Albert, Simon; Horning, Ned; Watson, James E. M.; Mumby, Peter J.; Jupiter, Stacy D.

    2018-04-01

    Increasing development in tropical regions provides new economic opportunities that can improve livelihoods, but it threatens the functional integrity and ecosystem services provided by terrestrial and aquatic ecosystems when conducted unsustainably. Given the small size of many islands, communities may have limited opportunities to replace loss and damage to the natural resources upon which they depend for ecosystem service provisioning, thus heightening the need for proactive, integrated management. This study quantifies the effectiveness of management strategies, stipulated in logging codes-of-practice, at minimizing soil erosion and sediment runoff as clearing extent increases, using Kolombangara Island, Solomon Islands as a case study. Further, we examine the ability of erosion reduction strategies to maintain sustainable soil erosion rates and reduce potential downstream impacts to drinking water and environmental water quality. We found that increasing land clearing—even with best management strategies in place—led to unsustainable levels of soil erosion and significant impacts to downstream water quality, compromising the integrity of the land for future agricultural uses, consistent access to clean drinking water, and important downstream ecosystems. Our results demonstrate that in order to facilitate sustainable development, logging codes of practice must explicitly link their soil erosion reduction strategies to soil erosion and downstream water quality thresholds, otherwise they will be ineffective at minimizing the impacts of logging activities. The approach taken here to explicitly examine soil erosion rates and downstream water quality in relation to best management practices and increasing land clearing should be applied more broadly across a range of ecosystems to inform decision-making about the socioeconomic and environmental trade-offs associated with logging, and other types of land use change.

  11. Preoperative implant planning considering alveolar bone grafting needs and complication prediction using panoramic versus CBCT images

    Energy Technology Data Exchange (ETDEWEB)

    Guerrero, Maria Eugenia; Jacobs, Reinhilde [OIC, OMFS IMPATH Research Group, Department of Imaging and Pathology, Faculty of Medicine, University of Leuven, Leuven (Belgium); Noriega, Jorge [Master of Periodontology, Universidad San Martin de Porres, Lima (Peru)

    2014-09-15

    This study was performed to determine the efficacy of observers' prediction for the need of bone grafting and presence of perioperative complications on the basis of cone-beam computed tomography (CBCT) and panoramic radiographic (PAN) planning as compared to the surgical outcome. One hundred and eight partially edentulous patients with a need for implant rehabilitation were referred for preoperative imaging. Imaging consisted of PAN and CBCT images. Four observers carried out implant planning using PAN image datasets, and at least one month later, using CBCT image datasets. Based on their own planning, the observers assessed the need for bone graft augmentation as well as complication prediction. The implant length and diameter, the need for bone graft augmentation, and the occurrence of anatomical complications during planning and implant placement were statistically compared. In the 108 patients, 365 implants were installed. Receiver operating characteristic analyses of both PAN and CBCT preoperative planning showed that CBCT performed better than PAN-based planning with respect to the need for bone graft augmentation and perioperative complications. The sensitivity and the specificity of CBCT for implant complications were 96.5% and 90.5%, respectively, and for bone graft augmentation, they were 95.2% and 96.3%, respectively. Significant differences were found between PAN-based planning and the surgery of posterior implant lengths. Our findings indicated that CBCT-based preoperative implant planning enabled treatment planning with a higher degree of prediction and agreement as compared to the surgical standard. In PAN-based surgery, the prediction of implant length was poor.

  12. Erosive gastritis

    International Nuclear Information System (INIS)

    Mohammed, S.H.; Conrad, C.; Kjoergaad, J.

    1982-01-01

    Erosive gastritis is a well-defined radiologic and endoscopic entity. It is one of the common causes of upper gastrointestinal bleeding, yet it is seldom diagnosed and often confused with a number of other diseases. This communication re-emphasizes the characteristic endoscopic and radiologic features of erosive gastritis and its differential diagnosis. Two representative cases are reported. (orig.)

  13. Erosive gastritis

    Energy Technology Data Exchange (ETDEWEB)

    Mohammed, S.H.; Conrad, C.; Kjoergaad, J.

    1982-08-01

    Erosive gastritis is a well-defined radiologic and endoscopic entity. It is one of the common causes of upper gastrointestinal bleeding, yet it is seldom diagnosed and often confused with a number of other diseases. This communication re-emphasizes the characteristic endoscopic and radiologic features of erosive gastritis and its differential diagnosis. Two representative cases are reported.

  14. Creep life prediction of super heater coils used in coal based thermal power plants subjected to fly ash erosion and oxide scale formation

    Science.gov (United States)

    Srinivasan, P.; Kushwaha, Shashank

    2018-04-01

    Super heater coils of the coal based thermal power plants and subjected to severe operating conditions from both steam side and gas side. Formation of oxide scale due to prolonged service lead to temperature raise of the tube and erosion due to fly ash present in the combusted gases leads to tube thinning. Both these factors lead to creep rupture of the coils much before the designed service life. Failure of super heater coils during service of the boiler leads to power loss and huge monitory loss to the power plants. An attempt is made to model the creep damage caused to the super heater coils using heat transfer analysis tube thinning due to erosive wear of the tubes. Combined effects of these parameters are taken into consideration to predict the life of the super heater coils. This model may be used to estimate the life of the coils operating under the severe operating conditions to prevent the unexpected failure of the coils.

  15. Hyperextension injuries of the knee. Do patterns of bone bruising predict soft tissue injury?

    Energy Technology Data Exchange (ETDEWEB)

    Ali, A.M.; Gibbons, C.E.R. [Chelsea and Westminster Hospital, Department of Orthopaedic Surgery, London (United Kingdom); Pillai, J.K.; Roberton, B.J. [Chelsea and Westminster Hospital, Department of Radiology, London (United Kingdom); Gulati, V. [Homerton University Hospital, Department of Orthopaedic Surgery, London (United Kingdom)

    2018-02-15

    To establish whether patterns of soft tissue injury following knee hyperextension are associated with post-traumatic 'bone bruise' distribution. Patients with a knee MRI within one year of hyperextension injury were identified at our institution over a 7 year period. MRIs, plain radiographs and clinical details of these patients were reviewed. Twenty-five patients were identified (median time from injury to MRI = 24 days). The most common sites of bone bruising were the anteromedial tibial plateau (48%) and anterolateral tibial plateau (44%). There were high rates of injury to the posterior capsule (52%), ACL (40%) and PCL (40%) but lower rates of injury to the menisci (20%), medial and lateral collateral ligaments (16%) and posterolateral corner (16%). Anterior tibial plateau oedema and rupture of the posterior capsule predicted cruciate ligament injury [OR = 10.5 (p = 0.02) and 24.0 (p = 0.001) respectively]. Whilst anterolateral tibial plateau oedema strongly predicted PCL injury [OR = 26.0, p = 0.003], ACL injury was associated with a variable pattern of bone bruising. Meniscal injury was unrelated to the extent or pattern of bone bruising. 5 out of 8 patients with a 'double sulcus' on the lateral radiograph had ACL injury. The presence of a double sulcus showed significant association with anteromedial kissing contusions (OR = 7.8, p = 0.03). Following knee hyperextension, bone bruising patterns may be associated with cruciate ligament injury. Other structures are injured less frequently and have weaker associations with bone bruise distribution. The double sulcus sign is a radiographic marker that confers a high probability of ACL injury. (orig.)

  16. Prediction of Local Ultimate Strain and Toughness of Trabecular Bone Tissue by Raman Material Composition Analysis

    Directory of Open Access Journals (Sweden)

    Roberto Carretta

    2015-01-01

    Full Text Available Clinical studies indicate that bone mineral density correlates with fracture risk at the population level but does not correlate with individual fracture risk well. Current research aims to better understand the failure mechanism of bone and to identify key determinants of bone quality, thus improving fracture risk prediction. To get a better understanding of bone strength, it is important to analyze tissue-level properties not influenced by macro- or microarchitectural factors. The aim of this pilot study was to identify whether and to what extent material properties are correlated with mechanical properties at the tissue level. The influence of macro- or microarchitectural factors was excluded by testing individual trabeculae. Previously reported data of mechanical parameters measured in single trabeculae under tension and bending and its compositional properties measured by Raman spectroscopy was evaluated. Linear and multivariate regressions show that bone matrix quality but not quantity was significantly and independently correlated with the tissue-level ultimate strain and postyield work (r=0.65–0.94. Principal component analysis extracted three independent components explaining 86% of the total variance, representing elastic, yield, and ultimate components according to the included mechanical parameters. Some matrix parameters were both included in the ultimate component, indicating that the variation in ultimate strain and postyield work could be largely explained by Raman-derived compositional parameters.

  17. Predicting Effects of Corrosion Erosion of High Strength Steel Pipelines Elbow on CO2-Acetic Acid (HAc) Solution

    International Nuclear Information System (INIS)

    Asmara, Y. P.; Ismail, M. F.; Chui, L. Giok; Halimi, Jamiludin

    2016-01-01

    Simultaneously effect of erosion combined with corrosion becomes the most concern in oil and gas industries. It is due to the fast deterioration of metal as effects of solid particles mixed with corrosive environment. There are many corrosion software to investigate possible degradation mechanisms developed by researchers. They are using many combination factors of chemical reactions and physical process. However effects of CO 2 and acid on pipelines orientations are still remain uncovered in their simulation. This research will investigate combination effects of CO 2 and HAc on corrosion and erosion artificial environmental containing sands particles in 45°, 90° and 180° elbow pipelines. The research used theoretical calculations combined with experiments for verification. The main concerns are to investigate the maximum erosion corrosion rate and maximum shear stress at the surface. Methodology used to calculate corrosion rate are Linear Polarization Resistance (LPR) and weight loss. The results showed that at 45°, erosion rate is the more significant effects in contributing degradation of the metal. The effects of CO 2 and HAc gave significant effects when flow rate of the solution are high which reflect synergism effects of solid particles and those chemical compositions. (paper)

  18. Observations and Predictions of Wave Runup, Extreme Water Levels, and Medium-Term Dune Erosion during Storm Conditions

    Directory of Open Access Journals (Sweden)

    Serge Suanez

    2015-07-01

    Full Text Available Monitoring of dune erosion and accretion on the high-energy macrotidal Vougot beach in North Brittany (France over the past decade (2004–2014 has revealed significant morphological changes. Dune toe erosion/accretion records have been compared with extreme water level measurements, defined as the sum of (i astronomic tide; (ii storm surge; and (iii vertical wave runup. Runup parameterization was conducted using swash limits, beach profiles, and hydrodynamic (Hm0, Tm0,–1, and high tide water level—HTWL data sets obtained from high frequency field surveys. The aim was to quantify in-situ environmental conditions and dimensional swash parameters for the best calibration of Battjes [1] runup formula. In addition, an empirical equation based on observed tidal water level and offshore wave height was produced to estimate extreme water levels over the whole period of dune morphological change monitoring. A good correlation between this empirical equation (1.01Hmoξo and field runup measurements (Rmax was obtained (R2 85%. The goodness of fit given by the RMSE was about 0.29 m. A good relationship was noticed between dune erosion and high water levels when the water levels exceeded the dune foot elevation. In contrast, when extreme water levels were below the height of the toe of the dune sediment budget increased, inducing foredune recovery. These erosion and accretion phases may be related to the North Atlantic Oscillation Index.

  19. Validation of adult height prediction based on automated bone age determination in the Paris Longitudinal Study of healthy children

    Energy Technology Data Exchange (ETDEWEB)

    Martin, David D. [Tuebingen University Children' s Hospital, Tuebingen (Germany); Filderklinik, Filderstadt (Germany); Schittenhelm, Jan [Tuebingen University Children' s Hospital, Tuebingen (Germany); Thodberg, Hans Henrik [Visiana, Holte (Denmark)

    2016-02-15

    An adult height prediction model based on automated determination of bone age was developed and validated in two studies from Zurich, Switzerland. Varied living conditions and genetic backgrounds might make the model less accurate. To validate the adult height prediction model on children from another geographical location. We included 51 boys and 58 girls from the Paris Longitudinal Study of children born 1953 to 1958. Radiographs were obtained once or twice a year in these children from birth to age 18. Bone age was determined using the BoneXpert method. Radiographs in children with bone age greater than 6 years were considered, in total 1,124 images. The root mean square deviation between the predicted and the observed adult height was 2.8 cm for boys in the bone age range 6-15 years and 3.1 cm for girls in the bone age range 6-13 years. The bias (the average signed difference) was zero, except for girls below bone age 12, where the predictions were 0.8 cm too low. The accuracy of the BoneXpert method in terms of root mean square error was as predicted by the model, i.e. in line with what was observed in the Zurich studies. (orig.)

  20. Validation of adult height prediction based on automated bone age determination in the Paris Longitudinal Study of healthy children

    International Nuclear Information System (INIS)

    Martin, David D.; Schittenhelm, Jan; Thodberg, Hans Henrik

    2016-01-01

    An adult height prediction model based on automated determination of bone age was developed and validated in two studies from Zurich, Switzerland. Varied living conditions and genetic backgrounds might make the model less accurate. To validate the adult height prediction model on children from another geographical location. We included 51 boys and 58 girls from the Paris Longitudinal Study of children born 1953 to 1958. Radiographs were obtained once or twice a year in these children from birth to age 18. Bone age was determined using the BoneXpert method. Radiographs in children with bone age greater than 6 years were considered, in total 1,124 images. The root mean square deviation between the predicted and the observed adult height was 2.8 cm for boys in the bone age range 6-15 years and 3.1 cm for girls in the bone age range 6-13 years. The bias (the average signed difference) was zero, except for girls below bone age 12, where the predictions were 0.8 cm too low. The accuracy of the BoneXpert method in terms of root mean square error was as predicted by the model, i.e. in line with what was observed in the Zurich studies. (orig.)

  1. Ability of One-Dimensional Hairsine-Rose Erosion Model to Predict Sediment Transport over a Soil with Significant Surface Stones

    Science.gov (United States)

    Jomaa, S.; Barry, D. A.; Sander, G. C.; Parlange, J.-Y.; Heng, B. C. P.; Tromp-van Meerveld, H. J.

    2010-05-01

    Surface stones affect erosion rates by reducing raindrop-driven detachment and protecting the original soil against overland flow induced-hydraulic stress. Numerous studies have shown that the effect of surface stones on erosion depends on both the stone characteristics (e.g., size, distribution) and the soil properties. The aim of this study was (i) to quantify how the stone characteristics can affect the total sediment concentration and the concentrations of the individual size classes, (ii) to test if stones affect preferentially a particular size class within the eroded sediment and (iii) to determine whether the 1D Hairsine-Rose (H-R) erosion model can represent the experimental data. A series of laboratory experiments were conducted using the 2 m × 6 m EPFL erosion flume for a high rainfall intensity (60 mm/h) event on a gentle slope (2.2%). The flume was divided into two identical 1-m wide flumes. This separation was done to allow simultaneous replicate experiments. Experiments were conducted with different configurations and scenarios (stone coverage, size and emplacement). Three coverage proportions (20%, 40%, and 70%), two stone diameters (3-4 and 6-7 cm) and two emplacement types (topsoil and partially embedded) were tested. For each experiment, the total sediment concentration, the concentration for the individual size classes, and the flume discharge were measured. Infiltration rates were measured at different depths and locations. A high resolution laser scanner provided details of the surface change due to erosion during the experiments. This technique allowed us to quantify the spatial distribution of eroded soil and to understand better if sediment transport is 1D or rather 2D over the flumes. The one-dimensional Hairsine-Rose (H-R) erosion model was used to fit the integrated data and to provide estimates of the parameters. The ability of the 1D H-R model to predict the measured sediment concentrations in the presence of stones in the soil matrix

  2. Real-Time Prediction of Temperature Elevation During Robotic Bone Drilling Using the Torque Signal.

    Science.gov (United States)

    Feldmann, Arne; Gavaghan, Kate; Stebinger, Manuel; Williamson, Tom; Weber, Stefan; Zysset, Philippe

    2017-09-01

    Bone drilling is a surgical procedure commonly required in many surgical fields, particularly orthopedics, dentistry and head and neck surgeries. While the long-term effects of thermal bone necrosis are unknown, the thermal damage to nerves in spinal or otolaryngological surgeries might lead to partial paralysis. Previous models to predict the temperature elevation have been suggested, but were not validated or have the disadvantages of computation time and complexity which does not allow real time predictions. Within this study, an analytical temperature prediction model is proposed which uses the torque signal of the drilling process to model the heat production of the drill bit. A simple Green's disk source function is used to solve the three dimensional heat equation along the drilling axis. Additionally, an extensive experimental study was carried out to validate the model. A custom CNC-setup with a load cell and a thermal camera was used to measure the axial drilling torque and force as well as temperature elevations. Bones with different sets of bone volume fraction were drilled with two drill bits ([Formula: see text]1.8 mm and [Formula: see text]2.5 mm) and repeated eight times. The model was calibrated with 5 of 40 measurements and successfully validated with the rest of the data ([Formula: see text]C). It was also found that the temperature elevation can be predicted using only the torque signal of the drilling process. In the future, the model could be used to monitor and control the drilling process of surgeries close to vulnerable structures.

  3. Temperature prediction in high speed bone grinding using motor PWM signal.

    Science.gov (United States)

    Tai, Bruce L; Zhang, Lihui; Wang, Anthony C; Sullivan, Stephen; Wang, Guangjun; Shih, Albert J

    2013-10-01

    This research explores the feasibility of using motor electrical feedback to estimate temperature rise during a surgical bone grinding procedure. High-speed bone grinding is often used during skull base neurosurgery to remove cranial bone and approach skull base tumors through the nasal corridor. Grinding-induced heat could propagate and potentially injure surrounding nerves and arteries, and therefore, predicting the temperature in the grinding region would benefit neurosurgeons during the operation. High-speed electric motors are controlled by pulse-width-modulation (PWM) to alter the current input and thus maintain the rotational speed. Assuming full mechanical to thermal power conversion in the grinding process, PWM can be used as feedback for heat generation and temperature prediction. In this study, the conversion model was established from experiments under a variety of grinding conditions and an inverse heat transfer method to determine heat flux. Given a constant rotational speed, the heat conversion was represented by a linear function, and could predict temperature from the experimental data with less than 20% errors. Such results support the advance of this technology for practical application. Copyright © 2013 IPEM. Published by Elsevier Ltd. All rights reserved.

  4. Prediction of Splint Therapy Efficacy Using Bone Scan in Patients with Unilateral Temporomandibular Disorder

    International Nuclear Information System (INIS)

    Lee, Sang Mi; Lee, Won Woo; Yun, Pil Young; Kim, Young Kyun; Kim, Sang Eun

    2009-01-01

    It is not known whether bone scan is useful for the prediction of the prognosis of patients with temporomandibular disorders (TMD). The aim of the present study was to identify useful prognostic markers on bone scan for the pre-therapeutic assessment of patients with unilateral TMD. Between January 2005 and July 2007, 55 patients (M:F=9:46; mean age, 34.7±14.1 y) with unilateral TMD that underwent a pre-therapeutic bone scan were enrolled. Uptake of Tc-99m HDP in each temporomandibular joint (TMJ) was quantitated using a 13X13 pixel-square region-of-interest over TMJ and parietal skull area as background. TMJ uptake ratios and asymmetric indices were calculated. TMD patients were classified as improved or not improved and the bone scan findings associated with each group were investigated. Forty-six patients were improved, whereas 9 patients were not improved. There was no significant difference between the two groups of patients regarding the TMJ uptake ratio of the involved joint, the TMJ uptake ratio of the non-involved joint, and the asymmetric index (p>0.05). However, in a subgroup analysis, the patients with an increased uptake of Tc-99m HDP at the disease-involved TMJ, by visual assessment, could be easily identified by the asymmetric index; the patients that improved had a higher asymmetric index than the patients that did not improve (1.32±0.35 vs. 1.08±0.04, p=0.023), The Tc-99m HDP bone scan may help predict the prognosis of patients with unilateral TMD after splint therapy when the TMD-involved joint reveals increased uptake by visual assessment

  5. Prediction of Splint Therapy Efficacy Using Bone Scan in Patients with Unilateral Temporomandibular Disorder

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Sang Mi; Lee, Won Woo; Yun, Pil Young; Kim, Young Kyun; Kim, Sang Eun [Seoul National University Bundang Hospital, Seoul (Korea, Republic of)

    2009-04-15

    It is not known whether bone scan is useful for the prediction of the prognosis of patients with temporomandibular disorders (TMD). The aim of the present study was to identify useful prognostic markers on bone scan for the pre-therapeutic assessment of patients with unilateral TMD. Between January 2005 and July 2007, 55 patients (M:F=9:46; mean age, 34.7{+-}14.1 y) with unilateral TMD that underwent a pre-therapeutic bone scan were enrolled. Uptake of Tc-99m HDP in each temporomandibular joint (TMJ) was quantitated using a 13X13 pixel-square region-of-interest over TMJ and parietal skull area as background. TMJ uptake ratios and asymmetric indices were calculated. TMD patients were classified as improved or not improved and the bone scan findings associated with each group were investigated. Forty-six patients were improved, whereas 9 patients were not improved. There was no significant difference between the two groups of patients regarding the TMJ uptake ratio of the involved joint, the TMJ uptake ratio of the non-involved joint, and the asymmetric index (p>0.05). However, in a subgroup analysis, the patients with an increased uptake of Tc-99m HDP at the disease-involved TMJ, by visual assessment, could be easily identified by the asymmetric index; the patients that improved had a higher asymmetric index than the patients that did not improve (1.32{+-}0.35 vs. 1.08{+-}0.04, p=0.023), The Tc-99m HDP bone scan may help predict the prognosis of patients with unilateral TMD after splint therapy when the TMD-involved joint reveals increased uptake by visual assessment.

  6. Osteoprotegerin autoantibodies do not predict low bone mineral density in middle-aged women.

    Science.gov (United States)

    Vaziri-Sani, Fariba; Brundin, Charlotte; Agardh, Daniel

    2017-12-01

    Autoantibodies against osteoprotegerin (OPG) have been associated with osteoporosis. The aim was to develop an immunoassay for OPG autoantibodies and test their diagnostic usefulness of identifying women general population with low bone mineral density. Included were 698 women at mean age 55.1 years (range 50.4-60.6) randomly selected from the general population. Measurement of wrist bone mineral density (g/cm 2 ) was performed of the non-dominant wrist by dual-energy X-ray absorptiometry (DXA). A T-score density. Measurements of OPG autoantibodies were carried by radiobinding assays. Cut-off levels for a positive value were determined from the deviation from normality in the distribution of 398 healthy blood donors representing the 99.7th percentile. Forty-five of the 698 (6.6%) women were IgG-OPG positive compared with 2 of 398 (0.5%) controls ( p  density between IgG-OPG positive (median 0.439 (range 0.315-0.547) g/cm 2 ) women and IgG-OPG negative (median 0.435 (range 0.176-0.652) g/cm 2 ) women ( p  = 0.3956). Furthermore, there was neither a correlation between IgG-OPG levels and bone mineral density (r s  = 0.1896; p  = 0.2068) nor T-score (r s  = 0.1889; p  = 0.2086). Diagnostic sensitivity and specificity of IgG-OPG for low bone mineral density were 5.7% and 92.9%, and positive and negative predictive values were 7.4% and 90.8%, respectively. Elevated OPG autoantibody levels do not predict low bone mineral density in middle-aged women selected from the general population.

  7. Upper Gastrointestinal Symptoms Predictive of Candida Esophagitis and Erosive Esophagitis in HIV and Non-HIV Patients: An Endoscopy-Based Cross-Sectional Study of 6011 Patients.

    Science.gov (United States)

    Takahashi, Yuta; Nagata, Naoyoshi; Shimbo, Takuro; Nishijima, Takeshi; Watanabe, Koji; Aoki, Tomonori; Sekine, Katsunori; Okubo, Hidetaka; Watanabe, Kazuhiro; Sakurai, Toshiyuki; Yokoi, Chizu; Mimori, Akio; Oka, Shinichi; Uemura, Naomi; Akiyama, Junichi

    2015-11-01

    Upper gastrointestinal (GI) symptoms are common in both HIV and non-HIV-infected patients, but the difference of GI symptom severity between 2 groups remains unknown. Candida esophagitis and erosive esophagitis, 2 major types of esophagitis, are seen in both HIV and non-HIV-infected patients, but differences in GI symptoms that are predictive of esophagitis between 2 groups remain unknown. We aimed to determine whether GI symptoms differ between HIV-infected and non-HIV-infected patients, and identify specific symptoms of candida esophagitis and erosive esophagitis between 2 groups.We prospectively enrolled 6011 patients (HIV, 430; non-HIV, 5581) who underwent endoscopy and completed questionnaires. Nine upper GI symptoms (epigastric pain, heartburn, acid regurgitation, hunger cramps, nausea, early satiety, belching, dysphagia, and odynophagia) were evaluated using a 7-point Likert scale. Associations between esophagitis and symptoms were analyzed by the multivariate logistic regression model adjusted for age, sex, and proton pump inhibitors.Endoscopy revealed GI-organic diseases in 33.4% (2010/6.011) of patients. The prevalence of candida esophagitis and erosive esophagitis was 11.2% and 12.1% in HIV-infected patients, respectively, whereas it was 2.9% and 10.7 % in non-HIV-infected patients, respectively. After excluding GI-organic diseases, HIV-infected patients had significantly (P symptom scores for heartburn, hunger cramps, nausea, early satiety, belching, dysphagia, and odynophagia than non-HIV-infected patients. In HIV-infected patients, any symptom was not significantly associated with CD4 cell count. In multivariate analysis, none of the 9 GI symptoms were associated with candida esophagitis in HIV-infected patients, whereas dysphagia and odynophagia were independently (P HIV-infected patients. However, heartburn and acid regurgitation were independently (P symptom scores were reliable in both HIV (α, 0.86) and non-HIV-infected patients (α, 0.85).This

  8. An Easy Tool to Predict Survival in Patients Receiving Radiation Therapy for Painful Bone Metastases

    Energy Technology Data Exchange (ETDEWEB)

    Westhoff, Paulien G., E-mail: p.g.westhoff@umcutrecht.nl [Department of Radiotherapy, University Medical Center Utrecht, Utrecht (Netherlands); Graeff, Alexander de [Department of Medical Oncology, University Medical Center Utrecht, Utrecht (Netherlands); Monninkhof, Evelyn M. [Julius Center for Health Sciences and Primary Care, University Medical Center Utrecht, Utrecht (Netherlands); Bollen, Laurens; Dijkstra, Sander P. [Department of Orthopedic Surgery, Leiden University Medical Center (Netherlands); Steen-Banasik, Elzbieta M. van der [ARTI Institute for Radiation Oncology Arnhem, Arnhem (Netherlands); Vulpen, Marco van [Department of Radiotherapy, University Medical Center Utrecht, Utrecht (Netherlands); Leer, Jan Willem H. [Department of Radiotherapy, University Medical Center Nijmegen, Nijmegen (Netherlands); Marijnen, Corrie A.; Linden, Yvette M. van der [Department of Clinical Oncology, Leiden University Medical Center, Leiden (Netherlands)

    2014-11-15

    Purpose: Patients with bone metastases have a widely varying survival. A reliable estimation of survival is needed for appropriate treatment strategies. Our goal was to assess the value of simple prognostic factors, namely, patient and tumor characteristics, Karnofsky performance status (KPS), and patient-reported scores of pain and quality of life, to predict survival in patients with painful bone metastases. Methods and Materials: In the Dutch Bone Metastasis Study, 1157 patients were treated with radiation therapy for painful bone metastases. At randomization, physicians determined the KPS; patients rated general health on a visual analogue scale (VAS-gh), valuation of life on a verbal rating scale (VRS-vl) and pain intensity. To assess the predictive value of the variables, we used multivariate Cox proportional hazard analyses and C-statistics for discriminative value. Of the final model, calibration was assessed. External validation was performed on a dataset of 934 patients who were treated with radiation therapy for vertebral metastases. Results: Patients had mainly breast (39%), prostate (23%), or lung cancer (25%). After a maximum of 142 weeks' follow-up, 74% of patients had died. The best predictive model included sex, primary tumor, visceral metastases, KPS, VAS-gh, and VRS-vl (C-statistic = 0.72, 95% CI = 0.70-0.74). A reduced model, with only KPS and primary tumor, showed comparable discriminative capacity (C-statistic = 0.71, 95% CI = 0.69-0.72). External validation showed a C-statistic of 0.72 (95% CI = 0.70-0.73). Calibration of the derivation and the validation dataset showed underestimation of survival. Conclusion: In predicting survival in patients with painful bone metastases, KPS combined with primary tumor was comparable to a more complex model. Considering the amount of variables in complex models and the additional burden on patients, the simple model is preferred for daily use. In addition, a risk table for survival is

  9. Three-phase Bone Scintigraphy Can Predict the Analgesic Efficacy of Ketamine Therapy in CRPS.

    Science.gov (United States)

    Sorel, Marc; Beatrix, Jacques-Christian; Locko, Blanche; Armessen, Catherine; Domec, Anne-Marie; Lecompte, Otilia; Boucheneb, Sofiane; Harache, Benoit; Robert, Jacques; Lefaucheur, Jean-Pascal

    2018-03-13

    The efficacy of ketamine in relieving complex regional pain syndrome (CRPS) lacks predictive factors. The value of three-phase bone scintigraphy (TPBS) was assessed or this purpose. TPBS was performed in 105 patients with unilateral, focal CRPS of type 1 before 5 days of ketamine infusions. Tracer uptake was measured in the region of interest concerned by CRPS and the contralateral homologous region. For the three scintigraphic phases (vascular, tissular, and bone phases), an asymmetry ratio of fixation was calculated between the affected and the unaffected sides (VPr, TPr, and BPr). Ketamine efficacy was assessed on pain intensity scores. Ketamine-induced pain relief did not correlate with VPr, TPr, and BPr, but with the ratios of these ratios: BPr/TPr (r=0.32, P=0.009), BPr/VPr (r=0.34, P=0.005), and TPr/VPr (r=0.23, P=0.02). The optimum cut-off value for predicting the response to ketamine therapy was >1.125 for BPr/TPr, >1.075 for BPr/VPr, and >0.935 for TPr/VPr. The combination of increased values of BPr/TPr, BPr/VPr, and TPr/VPr was extremely significantly associated with ketamine therapy outcome. The relative hyperfixation of the radioactive tracer in the limb region concerned by CRPS in phases 2 and 3 versus phase 1 of TPBS correlated positively to the analgesic efficacy of ketamine. This study shows for the first time the potential predictive value of TPBS regarding ketamine therapy outcome. In addition, these results suggest that the analgesic action of ketamine is not restricted to "central" mechanisms, but may also involve "peripheral" mechanisms related to tissue inflammation and bone remodeling.

  10. Modeling and experimental methods to predict oxygen distribution in bone defects following cell transplantation.

    Science.gov (United States)

    Heylman, Christopher M; Santoso, Sharon; Krebs, Melissa D; Saidel, Gerald M; Alsberg, Eben; Muschler, George F

    2014-04-01

    We have developed a mathematical model that allows simulation of oxygen distribution in a bone defect as a tool to explore the likely effects of local changes in cell concentration, defect size or geometry, local oxygen delivery with oxygen-generating biomaterials (OGBs), and changes in the rate of oxygen consumption by cells within a defect. Experimental data for the oxygen release rate from an OGB and the oxygen consumption rate of a transplanted cell population are incorporated into the model. With these data, model simulations allow prediction of spatiotemporal oxygen concentration within a given defect and the sensitivity of oxygen tension to changes in critical variables. This information may help to minimize the number of experiments in animal models that determine the optimal combinations of cells, scaffolds, and OGBs in the design of current and future bone regeneration strategies. Bone marrow-derived nucleated cell data suggest that oxygen consumption is dependent on oxygen concentration. OGB oxygen release is shown to be a time-dependent function that must be measured for accurate simulation. Simulations quantify the dependency of oxygen gradients in an avascular defect on cell concentration, cell oxygen consumption rate, OGB oxygen generation rate, and OGB geometry.

  11. Prediction of Tidal Elevations and Barotropic Currents in the Gulf of Bone

    Science.gov (United States)

    Purnamasari, Rika; Ribal, Agustinus; Kusuma, Jeffry

    2018-03-01

    Tidal elevation and barotropic current predictions in the gulf of Bone have been carried out in this work based on a two-dimensional, depth-integrated Advanced Circulation (ADCIRC-2DDI) model for 2017. Eight tidal constituents which were obtained from FES2012 have been imposed along the open boundary conditions. However, even using these very high-resolution tidal constituents, the discrepancy between the model and the data from tide gauge is still very high. In order to overcome such issues, Green’s function approach has been applied which reduced the root-mean-square error (RMSE) significantly. Two different starting times are used for predictions, namely from 2015 and 2016. After improving the open boundary conditions, RMSE between observation and model decreased significantly. In fact, RMSEs for 2015 and 2016 decreased 75.30% and 88.65%, respectively. Furthermore, the prediction for tidal elevations as well as tidal current, which is barotropic current, is carried out. This prediction was compared with the prediction conducted by Geospatial Information Agency (GIA) of Indonesia and we found that our prediction is much better than one carried out by GIA. Finally, since there is no tidal current observation available in this area, we assume that, when tidal elevations have been fixed, then the tidal current will approach the actual current velocity.

  12. Modeling the fluid/soil interface erosion in the Hole Erosion Test

    Directory of Open Access Journals (Sweden)

    Kissi B.

    2012-07-01

    Full Text Available Soil erosion is a complex phenomenon which yields at its final stage to insidious fluid leakages under the hydraulic infrastructures known as piping and which are the main cause of their rupture. The Hole Erosion Test is commonly used to quantify the rate of piping erosion. In this work, The Hole Erosion Test is modelled by using Fluent software package. The aim is to predict the erosion rate of soil during the hole erosion test. The renormalization group theory – based k–ε turbulence model equations are used. This modelling makes it possible describing the effect of the clay concentration in flowing water on erosion. Unlike the usual one dimensional models, the proposed modelling shows that erosion is not uniform erosion along the hole length. In particular, the concentration of clay is found to increase noticeably the erosion rate.

  13. The prediction of cyclic proximal humerus fracture fixation failure by various bone density measures.

    Science.gov (United States)

    Varga, Peter; Grünwald, Leonard; Windolf, Markus

    2018-02-22

    Fixation of osteoporotic proximal humerus fractures has remained challenging, but may be improved by careful pre-operative planning. The aim of this study was to investigate how well the failure of locking plate fixation of osteoporotic proximal humerus fractures can be predicted by bone density measures assessed with currently available clinical imaging (realistic case) and a higher resolution and quality modality (theoretical best-case). Various density measures were correlated to experimentally assessed number of cycles to construct failure of plated unstable low-density proximal humerus fractures (N = 18). The influence of density evaluation technique was investigated by comparing local (peri-implant) versus global evaluation regions; HR-pQCT-based versus clinical QCT-based image data; ipsilateral versus contralateral side; and bone mineral content (BMC) versus bone mineral density (BMD). All investigated density measures were significantly correlated with the experimental cycles to failure. The best performing clinically feasible parameter was the QCT-based BMC of the contralateral articular cap region, providing significantly better correlation (R 2  = 0.53) compared to a previously proposed clinical density measure (R 2  = 0.30). BMC had consistently, but not significantly stronger correlations with failure than BMD. The overall best results were obtained with the ipsilateral HR-pQCT-based local BMC (R 2  = 0.74) that may be used for implant optimization. Strong correlations were found between the corresponding density measures of the two CT image sources, as well as between the two sides. Future studies should investigate if BMC of the contralateral articular cap region could provide improved prediction of clinical fixation failure compared to previously proposed measures. © 2018 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res. © 2018 Orthopaedic Research Society. Published by Wiley Periodicals, Inc.

  14. Predictive role of prenasal thickness and nasal bone for Down syndrome in the second trimester.

    Science.gov (United States)

    Ozcan, Tulin; Özlü, Tülay; Allen, Julie; Peterson, Jeanne; Pressman, Eva K

    2013-12-01

    To assess the efficacy of prenasal thickness (PNT) and nasal bone (NB) for prediction of Down syndrome (DS) fetuses in the second trimester ultrasound examination. PNT was measured from stored two-dimensional fetal profile images taken at 15-23 weeks in 242 fetuses with normal karyotype (Group 1) and 24 fetuses with DS (Group 2). It was measured as the shortest distance from the anterior edge of the lowest part of the frontal bone to the skin. The efficacy of PNT, NB, PNT/NB and biparietal diameter (BPD)/NB was evaluated for prediction of DS. PNT values increased with gestational age in normal fetuses. PNT measurement was ≥95th percentile in 54.2% (13/24) of the DS cases and 2.9% of the normal cases. Receiver operator curve analysis showed that PNT/NB ratio had the best area under the curve with a detection rate of 80% for a false positive rate of 5% at a cut-off value of 0.76. PNT is increased in fetuses with DS as compared to normal fetuses. PNT/NB≥0.76 in the second trimester is a better predictor of DS than the use of PNT or NB alone. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

  15. Predictability of bone density at posterior mandibular implant sites using cone-beam computed tomography intensity values

    OpenAIRE

    Alkhader, Mustafa; Hudieb, Malik; Khader, Yousef

    2017-01-01

    Objective: The aim of this study was to investigate the predictability of bone density at posterior mandibular implant sites using cone-beam computed tomography (CBCT) intensity values. Materials and Methods: CBCT cross-sectional images for 436 posterior mandibular implant sites were selected for the study. Using Invivo software (Anatomage, San Jose, California, USA), two observers classified the bone density into three categories: low, intermediate, and high, and CBCT intensity values were g...

  16. Use of dietary Ca and P and photon absorptiometry to predict mechanical properties of bone in swine

    International Nuclear Information System (INIS)

    Crenshaw, T.D.; Golz, D.I.; Raab, D.M.; Smith, E.L.

    1986-01-01

    Photjon absorptiometry provides a noninvasive method to determine bone mineral content (BMC) in patients, yet the relationship of BMC and mechanical properties of bone has not been established. To establish the relationship between mechanical properties of bone and BMC, the third metatarsal bones (MT) from 72 growing pigs (23.4 +- 2.5 kg) were collected after either 5, 10 or 15 weeks (T1, T2 and T3) of being fed 1 of 9 treatments. A central composite response surface design was utilized to provide a range of Ca (0.4 to 1.2%) and P (0.4 to 1.2%) levels. Using photon absorptiometry, BMC was predicted from four scans on the midshaft of excised bone, mechanical tests (3-point flexure test) were made and the bone was ashed. BMC can predict force (r 2 = 0.89) and ash (r 2 = 0.97);however, interactions with Ca, P and T were detected. Stress was not predicted reliably with BMC (r 2 = 0.43), ash (r 2 = 0.40) or dietary Ca and P (r 2 = 0.41)

  17. Erhversbetinget erosion?

    DEFF Research Database (Denmark)

    Dige, Irene; Gjørup, Hans; Nyvad, Bente

    2012-01-01

    Baggrund – I forbindelse med dental erosion er en grundig udredning af patienten vigtig, således at årsagen til erosionernes opståen findes, og der kan iværksættes adækvat forebyggende indsats. En sådan udredning er ikke mindst vigtig, når arbejdsmiljøet mistænkes. Patienttilfælde – En 30-årig...... arbejdsskade, men ikke anerkendt, da erosioner ikke er optaget på Arbejdsskadestyrelsens liste over erhvervssygdomme. En systematisk registrering af lignende tilfælde kunne imidlertid på sigt ændre retspraksis for fremtidige patienter med arbejdsbetinget erosion....... patient, der arbejder som pladesmed, blev henvist til Landsdels- og Videnscenter, Århus Sygehus, med henblik på udredning af patientens kraftige slid. Patienten udviste ikke-alderssvarende tandslid af emalje og dentin svarende til erosion forårsaget af syredampe i arbejdsmiljøet, muligvis forstærket af...

  18. Impact assessment of rainfall-vegetation on sedimentation and predicting erosion-prone region by GIS and RS

    Directory of Open Access Journals (Sweden)

    Mahboob Alam

    2016-03-01

    Full Text Available Water reservoirs are facing universal sedimentation problems worldwide. Land covers, whether natural or manmade, eventually change, and the vegetation cover and rainfall have a great effect on the sediment load. Traditional techniques for analysing this problem are time-consuming and spatially limited. Remote sensing (RS provides a convenient way to observe land cover changes, and geographic information system (GIS provides tools for geographic analysis. This study demonstrates a GIS-based methodology for calculating the impact of vegetation and rainfall on the sediment load using remotely sensed data. Moderate resolution imaging spectroradiometer data were used to observe temporal changes in the vegetation-cover area of the watershed surface. The total drainage area for the reservoir was calculated from shuttle radar topographic mission data. The annual rainfall amount was used to compute the annual available rainwater for the watershed, and the impact of the annual available rainwater on the vegetation-covered area was determined. In addition, areas that were adding sedimentation to the reservoir were identified. An inverse relationship between the rainfall and vegetation cover was observed, clearly showing the triggering of erosion.

  19. Limitations of using micro-computed tomography to predict bone-implant contact and mechanical fixation.

    Science.gov (United States)

    Liu, S; Broucek, J; Virdi, A S; Sumner, D R

    2012-01-01

    Fixation of metallic implants to bone through osseointegration is important in orthopaedics and dentistry. Model systems for studying this phenomenon would benefit from a non-destructive imaging modality so that mechanical and morphological endpoints can more readily be examined in the same specimens. The purpose of this study was to assess the utility of an automated microcomputed tomography (μCT) program for predicting bone-implant contact (BIC) and mechanical fixation strength in a rat model. Femurs in which 1.5-mm-diameter titanium implants had been in place for 4 weeks were either embedded in polymethylmethacrylate (PMMA) for preparation of 1-mm-thick cross-sectional slabs (16 femurs: 32 slabs) or were used for mechanical implant pull-out testing (n= 18 femurs). All samples were scanned by μCT at 70 kVp with 16 μm voxels and assessed by the manufacturer's software for assessing 'osseointegration volume per total volume' (OV/TV). OV/TV measures bone volume per total volume (BV/TV) in a 3-voxel-thick ring that by default excludes the 3 voxels immediately adjacent to the implant to avoid metal-induced artefacts. The plastic-embedded samples were also analysed by backscatter scanning electron microscopy (bSEM) to provide a direct comparison of OV/TV with a well-accepted technique for BIC. In μCT images in which the implant was directly embedded within PMMA, there was a zone of elevated attenuation (>50% of the attenuation value used to segment bone from marrow) which extended 48 μm away from the implant surface. Comparison of the bSEM and μCT images showed high correlations for BV/TV measurements in areas not affected by metal-induced artefacts. In addition for bSEM images, we found that there were high correlations between peri-implant BV/TV within 12 μm of the implant surface and BIC (correlation coefficients ≥0.8, p implant pull-out strength (r= 0.401, p= 0.049) and energy to failure (r= 0.435, p= 0.035). Thus, the need for the 48-μm-thick exclusion

  20. User manual of Soil and Cesium Transport (SACT), a program to predict long-term Cs distribution using USLE for soil erosion, transportation and deposition

    International Nuclear Information System (INIS)

    Saito, Hiroshi; Yamaguchi, Masaaki; Kitamura, Akihiro

    2016-12-01

    This manual provides useful and necessary information to users of 'SACT' (Soil and Cesium Transport), which Japan Atomic Energy Agency (JAEA) has developed to predict a long-term distribution of Cs deposited on the land surface of Fukushima due to the Fukushima Daiichi Nuclear Power Station accident on March 11, 2011. SACT calculates soil movement (erosion, transportation and deposition) and resulting Cs migration, and predicts its future distribution, with the assumption that Cs is adhered to soil initially. SACT uses USLE (Universal Soil Loss Equation) for potential soil loss and simple hydraulic equations for soil transportation and deposition in which soil is divided into course-grained sand and fine-grained silt/clay. The amount of Cs moved with soil is predicted by the amount of above-mentioned soil movement and concentration ratio of Cs for each grain-size. SACT utilizes the 'ArcGIS' software and the GIS (Geographical Information System). SACT is characterized by its simplicity which enables fast calculation for wide area for long-term duration, using existing simple equations including USLE. Data for used parameters are widely available, and site-specific calculations are possible by using data obtained from the targeted area. (author)

  1. Using Anisotropic 3D Minkowski Functionals for Trabecular Bone Characterization and Biomechanical Strength Prediction in Proximal Femur Specimens

    Science.gov (United States)

    Nagarajan, Mahesh B.; De, Titas; Lochmüller, Eva-Maria; Eckstein, Felix; Wismüller, Axel

    2017-01-01

    The ability of Anisotropic Minkowski Functionals (AMFs) to capture local anisotropy while evaluating topological properties of the underlying gray-level structures has been previously demonstrated. We evaluate the ability of this approach to characterize local structure properties of trabecular bone micro-architecture in ex vivo proximal femur specimens, as visualized on multi-detector CT, for purposes of biomechanical bone strength prediction. To this end, volumetric AMFs were computed locally for each voxel of volumes of interest (VOI) extracted from the femoral head of 146 specimens. The local anisotropy captured by such AMFs was quantified using a fractional anisotropy measure; the magnitude and direction of anisotropy at every pixel was stored in histograms that served as a feature vectors that characterized the VOIs. A linear multi-regression analysis algorithm was used to predict the failure load (FL) from the feature sets; the predicted FL was compared to the true FL determined through biomechanical testing. The prediction performance was measured by the root mean square error (RMSE) for each feature set. The best prediction performance was obtained from the fractional anisotropy histogram of AMF Euler Characteristic (RMSE = 1.01 ± 0.13), which was significantly better than MDCT-derived mean BMD (RMSE = 1.12 ± 0.16, p<0.05). We conclude that such anisotropic Minkowski Functionals can capture valuable information regarding regional trabecular bone quality and contribute to improved bone strength prediction, which is important for improving the clinical assessment of osteoporotic fracture risk. PMID:29170581

  2. Predictability of bone density at posterior mandibular implant sites using cone-beam computed tomography intensity values.

    Science.gov (United States)

    Alkhader, Mustafa; Hudieb, Malik; Khader, Yousef

    2017-01-01

    The aim of this study was to investigate the predictability of bone density at posterior mandibular implant sites using cone-beam computed tomography (CBCT) intensity values. CBCT cross-sectional images for 436 posterior mandibular implant sites were selected for the study. Using Invivo software (Anatomage, San Jose, California, USA), two observers classified the bone density into three categories: low, intermediate, and high, and CBCT intensity values were generated. Based on the consensus of the two observers, 15.6% of sites were of low bone density, 47.9% were of intermediate density, and 36.5% were of high density. Receiver-operating characteristic analysis showed that CBCT intensity values had a high predictive power for predicting high density sites (area under the curve [AUC] =0.94, P < 0.005) and intermediate density sites (AUC = 0.81, P < 0.005). The best cut-off value for intensity to predict intermediate density sites was 218 (sensitivity = 0.77 and specificity = 0.76) and the best cut-off value for intensity to predict high density sites was 403 (sensitivity = 0.93 and specificity = 0.77). CBCT intensity values are considered useful for predicting bone density at posterior mandibular implant sites.

  3. Improved prediction of meat and bone meal metabolizable energy content for ducks through in vitro methods.

    Science.gov (United States)

    Garcia, R A; Phillips, J G; Adeola, O

    2012-08-01

    Apparent metabolizable energy (AME) of meat and bone meal (MBM) for poultry is highly variable, but impractical to measure routinely. Previous efforts at developing an in vitro method for predicting AME have had limited success. The present study uses data from a previous publication on the AME of 12 MBM samples, determined using 288 White Pekin ducks, as well as composition data on these samples. Here, we investigate the hypothesis that 2 noncompositional attributes of MBM, particle size and protease resistance, will have utility in improving predictions of AME based on in vitro measurements. Using the same MBM samples as the previous study, 2 measurements of particle size were recorded and protease resistance was determined using a modified pepsin digestibility assay. Analysis of the results using a stepwise construction of multiple linear regression models revealed that the measurements of particle size were useful in building models for AME, but the measure of protease resistance was not. Relatively simple (4-term) and complex (7-term) models for both AME and nitrogen-corrected AME were constructed, with R-squared values ranging from 0.959 to 0.996. The rather minor analytical effort required to conduct the measurements involved is discussed. Although the generality of the results are limited by the number of samples involved and the species used, they suggest that AME for poultry can be accurately predicted through simple and inexpensive in vitro methods.

  4. Tissue viscoelasticity is related to tissue composition but may not fully predict the apparent-level viscoelasticity in human trabecular bone – An experimental and finite element study

    DEFF Research Database (Denmark)

    Ojanen, X.; Tanska, P.; Malo, M. K.H.

    2017-01-01

    Trabecular bone is viscoelastic under dynamic loading. However, it is unclear how tissue viscoelasticity controls viscoelasticity at the apparent-level. In this study, viscoelasticity of cylindrical human trabecular bone samples (n = 11, male, age 18–78 years) from 11 proximal femurs were charact......). These findings indicate that bone tissue viscoelasticity is affected by tissue composition but may not fully predict the macroscale viscoelasticity in human trabecular bone....

  5. Use of Radiographic Densitometry to Predict the Bone Healing Index in Distraction Osteogenesis

    OpenAIRE

    A Saw; S Manimaran; S Faizal; AM Bulgiba

    2008-01-01

    Bone lengthening with distraction osteogenesis involves prolonged application of an external fixator frame. Qualitative and quantitative evaluation of callus has been described using various imaging modalities but there is no simple reliable and readily available method. This study aims to investigate the use of a densitometer to analyze plain radiographic images and correlate them with the rate of new bone formation as represented by the bone healing index. A total of 34 bone lengthening pro...

  6. Osteoporosis risk prediction for bone mineral density assessment of postmenopausal women using machine learning.

    Science.gov (United States)

    Yoo, Tae Keun; Kim, Sung Kean; Kim, Deok Won; Choi, Joon Yul; Lee, Wan Hyung; Oh, Ein; Park, Eun-Cheol

    2013-11-01

    A number of clinical decision tools for osteoporosis risk assessment have been developed to select postmenopausal women for the measurement of bone mineral density. We developed and validated machine learning models with the aim of more accurately identifying the risk of osteoporosis in postmenopausal women compared to the ability of conventional clinical decision tools. We collected medical records from Korean postmenopausal women based on the Korea National Health and Nutrition Examination Surveys. The training data set was used to construct models based on popular machine learning algorithms such as support vector machines (SVM), random forests, artificial neural networks (ANN), and logistic regression (LR) based on simple surveys. The machine learning models were compared to four conventional clinical decision tools: osteoporosis self-assessment tool (OST), osteoporosis risk assessment instrument (ORAI), simple calculated osteoporosis risk estimation (SCORE), and osteoporosis index of risk (OSIRIS). SVM had significantly better area under the curve (AUC) of the receiver operating characteristic than ANN, LR, OST, ORAI, SCORE, and OSIRIS for the training set. SVM predicted osteoporosis risk with an AUC of 0.827, accuracy of 76.7%, sensitivity of 77.8%, and specificity of 76.0% at total hip, femoral neck, or lumbar spine for the testing set. The significant factors selected by SVM were age, height, weight, body mass index, duration of menopause, duration of breast feeding, estrogen therapy, hyperlipidemia, hypertension, osteoarthritis, and diabetes mellitus. Considering various predictors associated with low bone density, the machine learning methods may be effective tools for identifying postmenopausal women at high risk for osteoporosis.

  7. Piezoelectricity could predict sites of formation/resorption in bone remodelling and modelling.

    Science.gov (United States)

    Fernández, J R; García-Aznar, J M; Martínez, R

    2012-01-07

    We have developed a mathematical approach for modelling the piezoelectric behaviour of bone tissue in order to evaluate the electrical surface charges in bone under different mechanical conditions. This model is able to explain how bones change their curvature, where osteoblasts or osteoclasts could detect in the periosteal/endosteal surfaces the different electrical charges promoting bone formation or resorption. This mechanism also allows to understand the BMU progression in function of the electro-mechanical bone behaviour. Copyright © 2011 Elsevier Ltd. All rights reserved.

  8. A mathematical model of reservoir sediment quality prediction based on land-use and erosion processes in watershed

    Science.gov (United States)

    Junakova, N.; Balintova, M.; Junak, J.

    2017-10-01

    The aim of this paper is to propose a mathematical model for determining of total nitrogen (N) and phosphorus (P) content in eroded soil particles with emphasis on prediction of bottom sediment quality in reservoirs. The adsorbed nutrient concentrations are calculated using the Universal Soil Loss Equation (USLE) extended by the determination of the average soil nutrient concentration in top soils. The average annual vegetation and management factor is divided into five periods of the cropping cycle. For selected plants, the average plant nutrient uptake divided into five cropping periods is also proposed. The average nutrient concentrations in eroded soil particles in adsorbed form are modified by sediment enrichment ratio to obtain the total nutrient content in transported soil particles. The model was designed for the conditions of north-eastern Slovakia. The study was carried out in the agricultural basin of the small water reservoir Klusov.

  9. Validation of a probabilistic post-fire erosion model

    Science.gov (United States)

    Pete Robichaud; William J. Elliot; Sarah A. Lewis; Mary Ellen Miller

    2016-01-01

    Post-fire increases of runoff and erosion often occur and land managers need tools to be able to project the increased risk. The Erosion Risk Management Tool (ERMiT) uses the Water Erosion Prediction Project (WEPP) model as the underlying processor. ERMiT predicts the probability of a given amount of hillslope sediment delivery from a single rainfall or...

  10. A novel registration-based methodology for prediction of trabecular bone fabric from clinical QCT: A comprehensive analysis.

    Directory of Open Access Journals (Sweden)

    Vimal Chandran

    Full Text Available Osteoporosis leads to hip fractures in aging populations and is diagnosed by modern medical imaging techniques such as quantitative computed tomography (QCT. Hip fracture sites involve trabecular bone, whose strength is determined by volume fraction and orientation, known as fabric. However, bone fabric cannot be reliably assessed in clinical QCT images of proximal femur. Accordingly, we propose a novel registration-based estimation of bone fabric designed to preserve tensor properties of bone fabric and to map bone fabric by a global and local decomposition of the gradient of a non-rigid image registration transformation. Furthermore, no comprehensive analysis on the critical components of this methodology has been previously conducted. Hence, the aim of this work was to identify the best registration-based strategy to assign bone fabric to the QCT image of a patient's proximal femur. The normalized correlation coefficient and curvature-based regularization were used for image-based registration and the Frobenius norm of the stretch tensor of the local gradient was selected to quantify the distance among the proximal femora in the population. Based on this distance, closest, farthest and mean femora with a distinction of sex were chosen as alternative atlases to evaluate their influence on bone fabric prediction. Second, we analyzed different tensor mapping schemes for bone fabric prediction: identity, rotation-only, rotation and stretch tensor. Third, we investigated the use of a population average fabric atlas. A leave one out (LOO evaluation study was performed with a dual QCT and HR-pQCT database of 36 pairs of human femora. The quality of the fabric prediction was assessed with three metrics, the tensor norm (TN error, the degree of anisotropy (DA error and the angular deviation of the principal tensor direction (PTD. The closest femur atlas (CTP with a full rotation (CR for fabric mapping delivered the best results with a TN error of 7

  11. Application of PCARES in locating the soil erosion Hotspots in the Manupali River Watershed

    OpenAIRE

    Paningbatan, E.

    2004-01-01

    In this presentation the author covers: GIS mapping of land attributes, dynamic modeling of soil erosion at watershed scale using PCARES (Predicting Catchment Runoff and Soil Erosion for Sustainability), identifying soil erosion "hotspots" in the Manupali River watershed

  12. Buffer erosion in dilute groundwater

    International Nuclear Information System (INIS)

    Schatz, T.; Kanerva, N.; Martikainen, J.; Sane, P.; Olin, M.; Seppaelae, A.; Koskinen, K.

    2013-08-01

    One scenario of interest for repository safety assessment involves the loss of bentonite buffer material in contact with dilute groundwater flowing through a transmissive fracture interface. In order to examine the extrusion/erosion behavior of bentonite buffer material under such circumstances, a series of experiments were performed in a flow-through, 1 mm aperture, artificial fracture system. These experiments covered a range of solution chemistry (salt concentration and composition), material composition (sodium montmorillonite and admixtures with calcium montmorillonite), and flow velocity conditions. No erosion was observed for sodium montmorillonite against solution compositions from 0.5 g/L to 10 g/L NaCl. No erosion was observed for 50/50 calcium/sodium montmorillonite against 0.5 g/L NaCl. Erosion was observed for both sodium montmorillonite and 50/50 calcium/sodium montmorillonite against solution compositions ≤ 0.25 g/L NaCl. The calculated erosion rates for the tests with the highest levels of measured erosion, i.e., the tests run under the most dilute conditions (ionic strength (IS) < ∼1 mM), were well-correlated to flow velocity, whereas the calculated erosion rates for the tests with lower levels of measured erosion, i.e., the tests run under somewhat less dilute conditions (∼1 mM < IS < ∼4 mM), were not similarly correlated indicating that material and solution composition can significantly affect erosion rates. In every experiment, both erosive and non-erosive, emplaced buffer material extruded into the fracture and was observed to be impermeable to water flowing in the fracture effectively forming an extended diffusive barrier around the intersecting fracture/buffer interface. Additionally, a model which was developed previously to predict the rate of erosion of bentonite buffer material in low ionic strength water in rock fracture environments was applied to three different cases: sodium montmorillonite expansion in a vertical tube, a

  13. Additively Manufactured Scaffolds for Bone Tissue Engineering and the Prediction of their Mechanical Behavior: A Review.

    Science.gov (United States)

    Zhang, Xiang-Yu; Fang, Gang; Zhou, Jie

    2017-01-10

    Additive manufacturing (AM), nowadays commonly known as 3D printing, is a revolutionary materials processing technology, particularly suitable for the production of low-volume parts with high shape complexities and often with multiple functions. As such, it holds great promise for the fabrication of patient-specific implants. In recent years, remarkable progress has been made in implementing AM in the bio-fabrication field. This paper presents an overview on the state-of-the-art AM technology for bone tissue engineering (BTE) scaffolds, with a particular focus on the AM scaffolds made of metallic biomaterials. It starts with a brief description of architecture design strategies to meet the biological and mechanical property requirements of scaffolds. Then, it summarizes the working principles, advantages and limitations of each of AM methods suitable for creating porous structures and manufacturing scaffolds from powdered materials. It elaborates on the finite-element (FE) analysis applied to predict the mechanical behavior of AM scaffolds, as well as the effect of the architectural design of porous structure on its mechanical properties. The review ends up with the authors' view on the current challenges and further research directions.

  14. AUC-based biomarker ensemble with an application on gene scores predicting low bone mineral density.

    Science.gov (United States)

    Zhao, X G; Dai, W; Li, Y; Tian, L

    2011-11-01

    The area under the receiver operating characteristic (ROC) curve (AUC), long regarded as a 'golden' measure for the predictiveness of a continuous score, has propelled the need to develop AUC-based predictors. However, the AUC-based ensemble methods are rather scant, largely due to the fact that the associated objective function is neither continuous nor concave. Indeed, there is no reliable numerical algorithm identifying optimal combination of a set of biomarkers to maximize the AUC, especially when the number of biomarkers is large. We have proposed a novel AUC-based statistical ensemble methods for combining multiple biomarkers to differentiate a binary response of interest. Specifically, we propose to replace the non-continuous and non-convex AUC objective function by a convex surrogate loss function, whose minimizer can be efficiently identified. With the established framework, the lasso and other regularization techniques enable feature selections. Extensive simulations have demonstrated the superiority of the new methods to the existing methods. The proposal has been applied to a gene expression dataset to construct gene expression scores to differentiate elderly women with low bone mineral density (BMD) and those with normal BMD. The AUCs of the resulting scores in the independent test dataset has been satisfactory. Aiming for directly maximizing AUC, the proposed AUC-based ensemble method provides an efficient means of generating a stable combination of multiple biomarkers, which is especially useful under the high-dimensional settings. lutian@stanford.edu. Supplementary data are available at Bioinformatics online.

  15. Application of a catchment evolution model to the prediction of long-term erosion on the spoil heap at Ranger uranium mine. Supervising Scientist report 132

    International Nuclear Information System (INIS)

    Willgoose, G.

    1998-01-01

    There is a need to assess the long-term stability of engineered landforms associated with the rehabilitation of Ranger Uranium Mine, Northern Territory, Australia, as it is a requirement that mill tailings must be contained for periods in excess of 1000 years. The geomorphic model, SIBERIA, is calibrated on hydrology and erosion data collected by a combination of monitoring and rainfall simulation experiments on the waste rock dumps of Ranger. Preliminary analysis of Ranger's preferred above-grade and below-grade rehabilitation options suggests that erosion of the order of 7-8 m will occur on the structure in a period of 1000 years. This depth of erosion may be sufficient to compromise the integrity of the containment. It is shown that SIBERIA has significant advantages over steady-state erosion models. Suggestions are made for the design that will enhance the stability of the structure and extend the structural life of the containment

  16. Measurement of Bone: Diagnosis of SCI-Induced Osteoporosis and Fracture Risk Prediction.

    Science.gov (United States)

    Troy, Karen L; Morse, Leslie R

    2015-01-01

    Spinal cord injury (SCI) is associated with a rapid loss of bone mass, resulting in severe osteoporosis and a 5- to 23-fold increase in fracture risk. Despite the seriousness of fractures in SCI, there are multiple barriers to osteoporosis diagnosis and wide variations in treatment practices for SCI-induced osteoporosis. We review the biological and structural changes that are known to occur in bone after SCI in the context of promoting future research to prevent or reduce risk of fracture in this population. We also review the most commonly used methods for assessing bone after SCI and discuss the strengths, limitations, and clinical applications of each method. Although dual-energy x-ray absorptiometry assessments of bone mineral density may be used clinically to detect changes in bone after SCI, 3-dimensional methods such as quantitative CT analysis are recommended for research applications and are explained in detail.

  17. Wind erosion modelling in a Sahelian environment

    NARCIS (Netherlands)

    Faye-Visser, S.M.; Sterk, G.; Karssenberg, D.

    2005-01-01

    In the Sahel field observations of wind-blown mass transport often show considerable spatial variation related to the spatial variation of the wind erosion controlling parameters, e.g. soil crust and vegetation cover. A model, used to predict spatial variation in wind erosion and deposition is a

  18. Mapping monthly rainfall erosivity in Europe

    DEFF Research Database (Denmark)

    Ballabio, C; Meusburger, K; Klik, A

    2017-01-01

    to Eastern Europe. The maps also show a clear delineation of areas with different erosivity seasonal patterns, whose spatial outline was evidenced by cluster analysis. The monthly erosivity maps can be used to develop composite indicators that map both intra-annual variability and concentration of erosive...... and seasonal R-factor maps and assess rainfall erosivity both spatially and temporally. During winter months, significant rainfall erosivity is present only in part of the Mediterranean countries. A sudden increase of erosivity occurs in major part of European Union (except Mediterranean basin, western part...... selected among various statistical models to perform the spatial interpolation due to its excellent performance, ability to model non-linearity and interpretability. The monthly prediction is an order more difficult than the annual one as it is limited by the number of covariates and, for consistency...

  19. Predictive value of ridge dimensions on autologous bone graft resorption in staged maxillary sinus augmentation surgery using Cone-Beam CT.

    NARCIS (Netherlands)

    Klijn, R.J.; Beucken, J.J.J.P van den; Bronkhorst, E.M.; Berge, S.J.; Meijer, G.J.; Jansen, J.B.M.J.

    2012-01-01

    INTRODUCTION: No studies are available that provide predictive parameters regarding the expected amount of resorption after maxillary sinus augmentation surgery using autologous bone grafts. Therefore, the aim of this study was to determine parameters influencing the outcome of the bone graft

  20. Modelling sewer sediment deposition, erosion, and transport processes to predict acute influent and reduce combined sewer overflows and CO(2) emissions.

    Science.gov (United States)

    Mouri, Goro; Oki, Taikan

    2010-01-01

    Understanding of solids deposition, erosion, and transport processes in sewer systems has improved considerably in the past decade. This has provided guidance for controlling sewer solids and associated acute pollutants to protect the environment and improve the operation of wastewater systems. Although measures to decrease combined sewer overflow (CSO) events have reduced the amount of discharged pollution, overflows continue to occur during rainy weather in combined sewer systems. The solution lies in the amount of water allotted to various processes in an effluent treatment system, in impact evaluation of water quality and prediction technology, and in stressing the importance of developing a control technology. Extremely contaminated inflow has been a serious research subject, especially in connection with the influence of rainy weather on nitrogen and organic matter removal efficiency in wastewater treatment plants (WWTP). An intensive investigation of an extremely polluted inflow load to WWTP during rainy weather was conducted in the city of Matsuyama, the region used for the present research on total suspended solid (TSS) concentration. Since the inflow during rainy weather can be as much as 400 times that in dry weather, almost all sewers are unsettled and overflowing when a rain event is more than moderate. Another concern is the energy consumed by wastewater treatment; this problem has become important from the viewpoint of reducing CO(2) emissions and overall costs. Therefore, while establishing a prediction technology for the inflow water quality characteristics of a sewage disposal plant is an important priority, the development of a management/control method for an effluent treatment system that minimises energy consumption and CO(2) emissions due to water disposal is also a pressing research topic with regards to the quality of treated water. The procedure to improve water quality must make use of not only water quality and biotic criteria, but also

  1. Controlled release pharmaceutical composition useful for the treatment of diseases and conditions affecting metabolism and/or structural integrity of cartilage and/or bone in male comprises strontium salt

    DEFF Research Database (Denmark)

    2004-01-01

    , hyperparathyroidism, periarticular erosions in rheumatoid arthritis, osteodystrophy, myositis ossificans, Bechterew's disease, osteolytic lesions produced by bone metastasis, bone pain due to bone metastasis, bone loss due to sex steroid hormone deficiency, bone abnormalities due to steroid hormone treatment, bone...

  2. Bone mineralisation in premature infants cannot be predicted from serum alkaline phosphatase or serum phosphate

    DEFF Research Database (Denmark)

    Faerk, J; Peitersen, Birgit; Petersen, S

    2002-01-01

    BACKGROUND: The bone mineral content of premature infants at term is lower than in mature infants at the same postconceptional age. Serum alkaline phosphatase and serum phosphate are often used as indicators of bone mineralisation. OBJECTIVE: To analyse the association between bone mineral content...... content was measured at term (mean gestational age 41 weeks) by dual energy x ray absorptiometry and corrected for body size. RESULTS: Serum alkaline phosphatase was significantly negatively associated with serum phosphate (p mineral content was not associated with mean serum alkaline...... and serum alkaline phosphatase and serum phosphate. METHODS: Serum alkaline phosphatase and phosphate were measured at weekly intervals during admission in 108 premature infants of gestational age below 32 weeks (mean (SD) gestational age 29 (2) weeks; mean (SD) birth weight 1129 (279) g). Bone mineral...

  3. Dynamic Failure Properties of the Porcine Medial Collateral Ligament-Bone Complex for Predicting Injury in Automotive Collisions

    Science.gov (United States)

    Peck, Louis; Billiar, Kristen; Ray, Malcolm

    2010-01-01

    The goal of this study was to model the dynamic failure properties of ligaments and their attachment sites to facilitate the development of more realistic dynamic finite element models of the human lower extremities for use in automotive collision simulations. Porcine medial collateral ligaments were chosen as a test model due to their similarities in size and geometry with human ligaments. Each porcine medial collateral ligament-bone complex (n = 12) was held in a custom test fixture placed in a drop tower to apply an axial impulsive impact load, applying strain rates ranging from 0.005 s-1 to 145 s-1. The data from the impact tests were analyzed using nonlinear regression to construct model equations for predicting the failure load of ligament-bone complexes subjected to specific strain rates as calculated from finite element knee, thigh, and hip impact simulations. The majority of the ligaments tested failed by tibial avulsion (75%) while the remaining ligaments failed via mid-substance tearing. The failure load ranged from 384 N to 1184 N and was found to increase with the applied strain rate and the product of ligament length and cross-sectional area. The findings of this study indicate the force required to rupture the porcine MCL increases with the applied bone-to-bone strain rate in the range expected from high speed frontal automotive collisions. PMID:20461229

  4. Rainfall Erosivity in Europe

    DEFF Research Database (Denmark)

    Panagos, Panos; Ballabio, Cristiano; Borrelli, Pasquale

    2015-01-01

    Rainfall is one the main drivers of soil erosion. The erosive force of rainfall is expressed as rainfall erosivity. Rainfall erosivity considers the rainfall amount and intensity, and is most commonly expressed as the Rfactor in the USLE model and its revised version, RUSLE. At national...... and continental levels, the scarce availability of data obliges soil erosion modellers to estimate this factor based on rainfall data with only low temporal resolution (daily, monthly, annual averages). The purpose of this study is to assess rainfall erosivity in Europe in the form of the RUSLE R-factor, based...

  5. Interleukin-15-activated natural killer cells kill autologous osteoclasts via LFA-1, DNAM-1 and TRAIL, and inhibit osteoclast-mediated bone erosion in vitro

    DEFF Research Database (Denmark)

    Feng, Shan; Madsen, Suzi H; Viller, Natasja N

    2015-01-01

    Osteoclasts reside on bone and are the main bone resorbing cells playing an important role in bone homeostasis, while natural killer (NK) cells are bone-marrow-derived cells known to play a crucial role in immune defence against viral infections. Although mature NK cells traffic through bone marrow...

  6. Soil erosion assessment on hillslope of GCE using RUSLE model

    Indian Academy of Sciences (India)

    Md. Rabiul Islam

    2018-05-22

    May 22, 2018 ... A vegetation density available on these plots is measured ... Finally, erosion prediction is computed based on the RUSLE model in ... which is lower compared to the C value from the soil erosion ..... Comparison of rainfall erosivity factor (R) value. ...... Vorovencii I and Muntean D 2012 Evaluation of super-.

  7. Assessing soil erosion risk in the Tillabery landscape, Niger ...

    African Journals Online (AJOL)

    The results show that soil erosion output scenarios predict greater soil erosion in the study area from 2070 onwards. They suggest that human disturbance and topographic factors are the main impact factors in the affected areas. Key words: Tillabéry landscape (Niger), sheet and rill erosion modelling, data mining.

  8. Bone mineral density at the hip predicts mortality in elderly men.

    Science.gov (United States)

    Trivedi, D P; Khaw, K T

    2001-01-01

    Low bone density as assessed by calcaneal ultrasound has been associated with mortality in elderly men and women. We examined the relationship between bone density measured at the hip and all cause and cardiovascular mortality in elderly men. Men aged 65-76 years from the general community were recruited from general practices in Cambridge between 1991 and 1995. At baseline survey, data collection included health questionnaires, measures of anthropometry and cardiovascular risk factors, as well as bone mineral density (BMD) measured using dual energy X-ray absorptiometry. All men have been followed up for vital status up to December 1999. BMD was significantly inversely related to mortality from all causes and cardiovascular disease, with decreasing rates with increasing bone density quartile, and an approximate halving of risk between the bottom and top quartile (p risk (95% CI 0.66-0.91) for all-cause mortality and 0.76 relative risk (95% CI 0.62-0.93) for cardiovascular disease mortality. The association remained significant after adjusting for age, body mass index, cigarette smoking status, serum cholesterol, systolic blood pressure, past history of heart attack, stroke or cancer and other lifestyle factors which included use of alcohol, physical activity and general health status. Low bone density at the hip is thus a strong and independent predictor of all-cause and cardiovascular mortality in older men.

  9. Influence of the pore fluid on the phase velocity in bovine trabecular bone In Vitro: Prediction of the biot model

    Science.gov (United States)

    Lee, Kang Il

    2013-01-01

    The present study aims to investigate the influence of the pore fluid on the phase velocity in bovine trabecular bone in vitro. The frequency-dependent phase velocity was measured in 20 marrow-filled and water-filled bovine femoral trabecular bone samples. The mean phase velocities at frequencies between 0.6 and 1.2 MHz exhibited significant negative dispersions for both the marrow-filled and the water-filled samples. The magnitudes of the dispersions showed no significant differences between the marrow-filled and the water-filled samples. In contrast, replacement of marrow by water led to a mean increase in the phase velocity of 27 m/s at frequencies from 0.6 to 1.2 MHz. The theoretical phase velocities of the fast wave predicted by using the Biot model for elastic wave propagation in fluid-saturated porous media showed good agreements with the measurements.

  10. Gene expression markers in circulating tumor cells may predict bone metastasis and response to hormonal treatment in breast cancer.

    Science.gov (United States)

    Wang, Haiying; Molina, Julian; Jiang, John; Ferber, Matthew; Pruthi, Sandhya; Jatkoe, Timothy; Derecho, Carlo; Rajpurohit, Yashoda; Zheng, Jian; Wang, Yixin

    2013-11-01

    Circulating tumor cells (CTCs) have recently attracted attention due to their potential as prognostic and predictive markers for the clinical management of metastatic breast cancer patients. The isolation of CTCs from patients may enable the molecular characterization of these cells, which may help establish a minimally invasive assay for the prediction of metastasis and further optimization of treatment. Molecular markers of proven clinical value may therefore be useful in predicting disease aggressiveness and response to treatment. In our earlier study, we identified a gene signature in breast cancer that appears to be significantly associated with bone metastasis. Among the genes that constitute this signature, trefoil factor 1 (TFF1) was identified as the most differentially expressed gene associated with bone metastasis. In this study, we investigated 25 candidate gene markers in the CTCs of metastatic breast cancer patients with different metastatic sites. The panel of the 25 markers was investigated in 80 baseline samples (first blood draw of CTCs) and 30 follow-up samples. In addition, 40 healthy blood donors (HBDs) were analyzed as controls. The assay was performed using quantitative reverse transcriptase polymerase chain reaction (qRT-PCR) with RNA extracted from CTCs captured by the CellSearch system. Our study indicated that 12 of the genes were uniquely expressed in CTCs and 10 were highly expressed in the CTCs obtained from patients compared to those obtained from HBDs. Among these genes, the expression of keratin 19 was highly correlated with the CTC count. The TFF1 expression in CTCs was a strong predictor of bone metastasis and the patients with a high expression of estrogen receptor β in CTCs exhibited a better response to hormonal treatment. Molecular characterization of these genes in CTCs may provide a better understanding of the mechanism underlying tumor metastasis and identify gene markers in CTCs for predicting disease progression and

  11. Comparing the effects of tofacitinib, methotrexate and the combination, on bone marrow oedema, synovitis and bone erosion in methotrexate-naive, early active rheumatoid arthritis: results of an exploratory randomised MRI study incorporating semiquantitative and quantitative techniques

    DEFF Research Database (Denmark)

    Conaghan, Philip G.; Ostergaard, Mikkel; Bowes, Michael A.

    2016-01-01

    OBJECTIVES: To explore the effects of tofacitinib-an oral Janus kinase inhibitor for the treatment of rheumatoid arthritis (RA)-with or without methotrexate (MTX), on MRI endpoints in MTX-naive adult patients with early active RA and synovitis in an index wrist or hand. METHODS: In this exploratory......, phase 2, randomised, double-blind, parallel-group study, patients received tofacitinib 10 mg twice daily + MTX, tofacitinib 10 mg twice daily + placebo (tofacitinib monotherapy), or MTX + placebo (MTX monotherapy), for 1 year. MRI endpoints (Outcome Measures in Rheumatology Clinical Trials RA MRI score...... differences in RAMRIS bone marrow oedema (BME) at month 6 were -1.55 (90% CI -2.52 to -0.58) for tofacitinib + MTX and -1.74 (-2.72 to -0.76) for tofacitinib monotherapy (both ptofacitinib + MTX...

  12. Objectively measured physical activity predicts hip and spine bone mineral content in children and adolescents ages 5 - 15 years: Iowa Bone Development Study

    Directory of Open Access Journals (Sweden)

    Kathleen F Janz

    2014-07-01

    Full Text Available This study examined the association between physical activity (PA and bone mineral content (BMC; g from middle childhood to middle adolescence and compared the impact of vigorous-intensity PA (VPA over moderate- to vigorous-intensity PA (MVPA. Participants from the Iowa Bone Development Study were examined at ages 5, 8, 11, 13, and 15 yr (n=369, 449, 452, 410, 307, respectively. MVPA and VPA (min/day were measured using ActiGraph accelerometers. Anthropometry was used to measure body size and somatic maturity. Spine BMC and hip BMC were measured via dual-energy x-ray absorptiometry. Sex-specific multi-level linear models were fit for spine BMC and hip BMC, adjusted for weight (kg, height (cm, linear age (yr, non-linear age (yr2, and maturity (pre peak height velocity vs. at/post peak height velocity. The interaction effects of PA×maturity and PA×age were tested. We also examined differences in spine BMC and hip BMC between the least (10th percentile and most (90th percentile active participants at each examination period. Results indicated that PA added to prediction of BMC throughout the 10-year follow-up, except MVPA did not predict spine BMC in females. Maturity and age did not modify the PA effect for males nor females. At age 5, the males at the 90th percentile for VPA had 8.5% more hip BMC than males in the 10th percentile for VPA. At age 15, this difference was 2.0%. Females at age 5 in the 90th percentile for VPA had 6.1% more hip BMC than those in the 10th percentile for VPA. The age 15 difference was 1.8%. VPA was associated with BMC at weight-bearing skeletal sites from childhood to adolescence, and the effect was not modified by maturity or age. Our findings indicate the importance of early and sustained interventions that focus on VPA. Approaches focused on MVPA may be inadequate for optimal bone health, particularly for females.

  13. Comparing the effects of tofacitinib, methotrexate and the combination, on bone marrow oedema, synovitis and bone erosion in methotrexate-naive, early active rheumatoid arthritis: results of an exploratory randomised MRI study incorporating semiquantitative and quantitative techniques.

    Science.gov (United States)

    Conaghan, Philip G; Østergaard, Mikkel; Bowes, Michael A; Wu, Chunying; Fuerst, Thomas; van der Heijde, Désirée; Irazoque-Palazuelos, Fedra; Soto-Raices, Oscar; Hrycaj, Pawel; Xie, Zhiyong; Zhang, Richard; Wyman, Bradley T; Bradley, John D; Soma, Koshika; Wilkinson, Bethanie

    2016-06-01

    To explore the effects of tofacitinib-an oral Janus kinase inhibitor for the treatment of rheumatoid arthritis (RA)-with or without methotrexate (MTX), on MRI endpoints in MTX-naive adult patients with early active RA and synovitis in an index wrist or hand. In this exploratory, phase 2, randomised, double-blind, parallel-group study, patients received tofacitinib 10 mg twice daily + MTX, tofacitinib 10 mg twice daily + placebo (tofacitinib monotherapy), or MTX + placebo (MTX monotherapy), for 1 year. MRI endpoints (Outcome Measures in Rheumatology Clinical Trials RA MRI score (RAMRIS), quantitative RAMRIS (RAMRIQ) and dynamic contrast-enhanced (DCE) MRI) were assessed using a mixed-effect model for repeated measures. Treatment differences with ptofacitinib + MTX and -1.74 (-2.72 to -0.76) for tofacitinib monotherapy (both ptofacitinib + MTX and -0.52 (-1.46 to 0.41) for tofacitinib monotherapy (both p>0.05 vs MTX monotherapy). Treatment differences in RAMRIQ synovitis were statistically significant at month 3, consistent with DCE MRI findings. Less deterioration of RAMRIS and RAMRIQ erosive damage was seen at months 6 and 12 in both tofacitinib groups versus MTX monotherapy. These results provide consistent evidence using three different MRI technologies that tofacitinib treatment leads to early reduction of inflammation and inhibits progression of structural damage. NCT01164579. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

  14. Soil loss prediction in Guaraíra river experimental basin, Paraíba, Brazil based on two erosion simulation models

    Directory of Open Access Journals (Sweden)

    Jorge Flávio Cazé B. da Costa Silva

    2007-12-01

    Full Text Available In this study, two hydrological models to estimate soil losses and sediment yield due to sheet and channel erosion, at the basin outlet, are applied to Guaraíra River Experimental Basin, located in Paraíba State, northeastern Brazil. The soil erosion models are (a the classical Universal Soil Loss Equation (USLE, which is used to simulate annual and monthly soil losses; and (b Kineros model, which is used to simulate the sediment yield within the basin. Kineros model is a physically-based distributed model that uses a cascade of planes and channels to represent the basin and to describe the processes of interception, infiltration, surface runoff and erosion within the basin. The USLE is computed using land use, soil erodibility, topographic digital maps, as well as observed rainfall data. It was found that Guaraíra river experimental basin has a low potential for soil losses; however, specific areas which are susceptible to the erosion process in the basin could be detected by the modeling techniques coupled to a GIS (Geographic Information System.

  15. Mapping erosion from space

    NARCIS (Netherlands)

    Vrieling, A.

    2007-01-01

    Soil erosion by water is the most important land degradation problem worldwide. Spatial information on erosion is required for defining effective soil and water conservation strategies. Satellite remote sensing can provide relevant input to regional erosion assessment. This thesis comprises a review

  16. Erosion-corrosion

    International Nuclear Information System (INIS)

    Aghili, B.

    1999-05-01

    A literature study on erosion-corrosion of pipings in the nuclear industry was performed. Occurred incidents are reviewed, and the mechanism driving the erosion-corrosion is described. Factors that influence the effect in negative or positive direction are treated, as well as programs for control and inspection. Finally, examples of failures from databases on erosion-corrosion are given in an attachment

  17. Assessing storm erosion hazards

    NARCIS (Netherlands)

    Ranasinghe, Ranasinghe W M R J B; Callaghan, D.; Ciavola, Paolo; Coco, Giovanni

    2017-01-01

    The storm erosion hazard on coasts is usually expressed as an erosion volume and/or associated episodic coastline retreat. The accurate assessment of present-day and future storm erosion volumes is a key task for coastal zone managers, planners and engineers. There are four main approaches that can

  18. Sensitivity of tissue differentiation and bone healing predictions to tissue properties

    NARCIS (Netherlands)

    Isaksson, H.E.; Donkelaar, van C.C.; Ito, K.

    2009-01-01

    Computational models are employed as tools to investigate possible mechano-regulation pathways for tissue differentiation and bone healing. However, current models do not account for the uncertainty in input parameters, and often include assumptions about parameter values that are not yet

  19. Modelling rainfall erosion resulting from climate change

    Science.gov (United States)

    Kinnell, Peter

    2016-04-01

    It is well known that soil erosion leads to agricultural productivity decline and contributes to water quality decline. The current widely used models for determining soil erosion for management purposes in agriculture focus on long term (~20 years) average annual soil loss and are not well suited to determining variations that occur over short timespans and as a result of climate change. Soil loss resulting from rainfall erosion is directly dependent on the product of runoff and sediment concentration both of which are likely to be influenced by climate change. This presentation demonstrates the capacity of models like the USLE, USLE-M and WEPP to predict variations in runoff and erosion associated with rainfall events eroding bare fallow plots in the USA with a view to modelling rainfall erosion in areas subject to climate change.

  20. Managing dental erosion.

    Science.gov (United States)

    Curtis, Donald A; Jayanetti, Jay; Chu, Raymond; Staninec, Michal

    2012-01-01

    The clinical signs of dental erosion are initially subtle, yet often progress because the patient remains asymptomatic, unaware and uninformed. Erosion typically works synergistically with abrasion and attrition to cause loss of tooth structure, making diagnosis and management complex. The purpose of this article is to outline clinical examples of patients with dental erosion that highlight the strategy of early identification, patient education and conservative restorative management. Dental erosion is defined as the pathologic chronic loss of dental hard tissues as a result of the chemical influence of exogenous or endogenous acids without bacterial involvement. Like caries or periodontal disease, erosion has a multifactorial etiology and requires a thorough history and examination for diagnosis. It also requires patient understanding and compliance for improved outcomes. Erosion can affect the loss of tooth structure in isolation of other cofactors, but most often works in synergy with abrasion and attrition in the loss of tooth structure (Table 1). Although erosion is thought to be an underlying etiology of dentin sensitivity, erosion and loss of tooth structure often occurs with few symptoms. The purpose of this article is threefold: first, to outline existing barriers that may limit early management of dental erosion. Second, to review the clinical assessment required to establish a diagnosis of erosion. And third, to outline clinical examples that review options to restore lost tooth structure. The authors have included illustrations they hope will be used to improve patient understanding and motivation in the early management of dental erosion.

  1. Predicting Hip Fracture Type With Cortical Bone Mapping (CBM) in the Osteoporotic Fractures in Men (MrOS) Study.

    Science.gov (United States)

    Treece, Graham M; Gee, Andrew H; Tonkin, Carol; Ewing, Susan K; Cawthon, Peggy M; Black, Dennis M; Poole, Kenneth E S

    2015-11-01

    Hip fracture risk is known to be related to material properties of the proximal femur, but fracture prediction studies adding richer quantitative computed tomography (QCT) measures to dual-energy X-ray (DXA)-based methods have shown limited improvement. Fracture types have distinct relationships to predictors, but few studies have subdivided fracture into types, because this necessitates regional measurements and more fracture cases. This work makes use of cortical bone mapping (CBM) to accurately assess, with no prior anatomical presumptions, the distribution of properties related to fracture type. CBM uses QCT data to measure the cortical and trabecular properties, accurate even for thin cortices below the imaging resolution. The Osteoporotic Fractures in Men (MrOS) study is a predictive case-cohort study of men over 65 years old: we analyze 99 fracture cases (44 trochanteric and 55 femoral neck) compared to a cohort of 308, randomly selected from 5994. To our knowledge, this is the largest QCT-based predictive hip fracture study to date, and the first to incorporate CBM analysis into fracture prediction. We show that both cortical mass surface density and endocortical trabecular BMD are significantly different in fracture cases versus cohort, in regions appropriate to fracture type. We incorporate these regions into predictive models using Cox proportional hazards regression to estimate hazard ratios, and logistic regression to estimate area under the receiver operating characteristic curve (AUC). Adding CBM to DXA-based BMD leads to a small but significant (p fracture, with AUC increasing from 0.78 to 0.79, assessed using leave-one-out cross-validation. For specific fracture types, the improvement is more significant (p trochanteric fractures and 0.76 to 0.82 for femoral neck fractures. In contrast, adding DXA-based BMD to a CBM-based predictive model does not result in any significant improvement. © 2015 The Authors. Journal of Bone and Mineral Research

  2. Can high-resolution peripheral quantitative computed tomography imaging of subchondral and cortical bone predict condylar fracture in Thoroughbred racehorses?

    Science.gov (United States)

    Trope, G D; Ghasem-Zadeh, A; Anderson, G A; Mackie, E J; Whitton, R C

    2015-07-01

    High-resolution 3D imaging may improve the prediction and/or early identification of condylar fractures of the distal metacarpus/tarsus and reduce the frequency of breakdown injury in racehorses. To test the hypotheses that horses suffering condylar fractures have higher bone volume fraction (BV/TV) of the distal metacarpal epiphysis, greater subchondral bone thickness at the fracture site and higher second moment of inertia in the metacarpal midshaft as identified with high-resolution 3D imaging. Cross-sectional study using cadaver material. Thoroughbreds that died on racetracks were grouped as: 1) horses with third metacarpal (McIII) fractures with a condylar component (cases, n = 13); 2) horses with no limb fracture (controls, n = 8); 3) horses with fractures in other bones or suspensory apparatus disruption (other fatal injuries, n = 16). The palmar condyles of McIII and the midshaft were examined with high resolution peripheral quantitative computed tomography (HR-pQCT). Statistical analysis included logistic regression and Spearman's correlation. There were no significant differences in BV/TV of distal McIII and second moment of inertia of the midshaft between cases and controls. Epiphyseal bone BV/TV was greater in injured limbs of horses with any fatal limb injury (Groups 1 and 3 combined) compared with controls (odds ratio = 1.20, 95% confidence interval 1.01-1.42, P = 0.034). An epiphyseal BV/TV>0.742 resulted in a sensitivity of 82.8% and specificity of 62.5% in identifying horses with fatal limb injury. In horses without condylar fracture, increased subchondral bone thickness was associated with palmar osteochondral disease lesions in the adjacent condyle (rs = 0.65, Phorses at risk of any fatal breakdown injury but not metacarpal condylar fractures. Measurement of parasagittal groove subchondral bone thickness is complicated by adjacent palmar osteochondral disease lesions. Thus, high-resolution imaging of the distal metacarpus appears to have limited

  3. Molybdenum erosion measurements in Alcator C-Mod

    Energy Technology Data Exchange (ETDEWEB)

    Wampler, W.R. [Sandia National Labs., Albuquerque, NM (United States); LaBombard, B.; Lipshultz, B.; Pappas, D.; Pitcher, C.S. [Massachusetts Inst. of Tech., Cambridge, MA (United States); McCracken, G.M. [JET Joint Undertaking, Abingdon (United Kingdom)

    1998-05-01

    Erosion of molybdenum was measured on a set of 21 tiles after a run campaign of 1,090 shots in the Alcator C-Mod tokamak. The net erosion of molybdenum, was determined from changes in the depth of a thin chromium marker layer measured by Rutherford backscattering. Net Mo erosion was found to be approximately 150 nm near the outer divertor strike point, and much less everywhere else. Gross erosion rates by sputtering were estimated using ion energies and fluxes obtained from Langmuir probe measurements of edge-plasma conditions. Predicted net erosion using calculated gross erosion with prompt redeposition and measured net erosion agree within a factor of 3. Sputtering by boron and molybdenum impurities dominates erosion.

  4. Three procedures for estimating erosion from construction areas

    International Nuclear Information System (INIS)

    Abt, S.R.; Ruff, J.F.

    1978-01-01

    Erosion from many mining and construction sites can lead to serious environmental pollution problems. Therefore, erosion management plans must be developed in order that the engineer may implement measures to control or eliminate excessive soil losses. To properly implement a management program, it is necessary to estimate potential soil losses from the time the project begins to beyond project completion. Three methodologies are presented which project the estimated soil losses due to sheet or rill erosion of water and are applicable to mining and construction areas. Furthermore, the three methods described are intended as indicators of the state-of-the-art in water erosion prediction. The procedures herein do not account for gully erosion, snowmelt erosion, wind erosion, freeze-thaw erosion or extensive flooding

  5. Dietary and Urinary Sulfur can Predict Changes in Bone Metabolism During Space Flight

    Science.gov (United States)

    Zwart, Sara R.; Heer, Martina; Shackelford, Linda; Smith, Scott M.

    2015-01-01

    Mitigating space flight-induced bone loss is critical for space exploration, and diet can play a major role in this effort. Previous ground-based studies provide evidence that dietary composition can influence bone resorption during bed rest. In this study we examined the role of dietary intake patterns as one factor that can influence bone mineral loss in astronauts during space flight. Crew members were asked to consume, for 4 days at a time, prescribed menus with either a low (0.3-0.6 g/mEq) or high (1.0-1.3 g/mEq) ratio of animal protein to potassium (APro:K). Menus were developed for each crewmember, and were designed to meet both crew preferences and study constraints. Intakes of energy, total protein, calcium, and sodium were held relatively constant between the two diets. The order of the menus was randomized, and crews completed each set (low and high) once before and twice during space flight, for a total of 6 controlled diet sessions. One inflight session and three postflight sessions (R+30, R+180, R+365) monitored typical dietary intake. As of this writing, data are available from 14 crew members. The final three subjects' inflight samples are awaiting return from the International Space Station via Space-X. On the last day of each of the 4-d controlled diet sessions, 24-h urine samples were collected, along with a fasting blood sample on the morning of the 5th day. Preliminary analyses show that urinary excretion of sulfate (normalized to lean body mass) is a significant predictor of urinary n-telopeptide (NTX). Dietary sulfate (normalized to lean body mass) is also a significant predictor of urinary NTX. The results from this study, will be important to better understand diet and bone interrelationships during space flight as well as on Earth. This study was funded by the Human Health Countermeasures Element of the NASA Human Research Program.

  6. Does microtia predict severity of temporal bone CT abnormalities in children with persistent conductive hearing loss?

    Science.gov (United States)

    Tekes, Aylin; Ishman, Stacey L; Baugher, Katherine M; Brown, David J; Lin, Sandra Y; Tunkel, David E; Unalp-Arida, Aynur; Huisman, Thierry A G M

    2013-07-01

    This study aimed to determine the spectrum of temporal bone computed tomography (CT) abnormalities in children with conductive hearing loss (CHL) with and without microtia. From 1993 to 2008, a total of 3396 pediatric records including CHL were reviewed at our institution and revealed 180 cases of persistent CHL, 46 of whom had diagnostic temporal bone CT examinations. All of these examinations were systematically reviewed by two pediatric neuroradiologists, working in consensus, who had 5 and 18 years, respectively, of dedicated pediatric neuroradiology experience. Of the 46 children, 16 were boys and 30 were girls (age: 0.2-16 years; mean: 5 years). Also, 21 (46%) children had microtia and 25 (54%) children did not, as determined by clinical evaluation. External auditory canal atresia/stenosis (EAC-A/S) was the most common anomaly in both microtia and non-microtia groups. Two or more anomalies were observed in 18/21 children with microtia. The frequency of EAC-A/S was greater in children with microtia versus those without it (86% versus 32%, respectively; P = 0.0003). Syndromic diagnoses were also significantly more frequently made in children with microtia versus those without microtia (76% versus 20%, respectively; P = 0.0001). Temporal bone CT scans were normal in 10 children (22%) with persistent CHL. Microtia is an important finding in children with CHL. EAC and middle ear/ossicle anomalies were significantly more frequently seen in children with microtia, and multiple anomalies and bilateral microtia were more common in children with syndromic associations. These findings highlight the importance of understanding the embryological development of the temporal bone. The presence of one anomaly should raise suspicion of the possibility of other anomalies, especially in the setting of microtia. Bilateral microtia and multiple anomalies should also raise suspicion of genetic syndromes. Copyright © 2012 Elsevier Masson SAS. All rights reserved.

  7. Dual-energy X-ray absorptiometry predicts bone formation in lower limb callotasis lengthening.

    OpenAIRE

    Maffulli, N.; Cheng, J. C.; Sher, A.; Lam, T. P.

    1997-01-01

    The rate of regenerate bone mineral content (BMC) acceleration was studied using dual-energy X-ray absorptiometry (DEXA) in callotasis lengthening of the lower limb. Eleven youngsters (age range 5-17 years) undergoing callotasis lengthening for congenital, post-traumatic or post-infective conditions were studied longitudinally. Patients were initially scanned once a week until completion of the lengthening phase, and at 2-week intervals thereafter until removal of the fixator. They were subse...

  8. Role of bone mineral density in predicting morphometric vertebral fractures in patients with HIV infection.

    Science.gov (United States)

    Porcelli, T; Gotti, D; Cristiano, A; Maffezzoni, F; Mazziotti, G; Focà, E; Castelli, F; Giustina, A; Quiros-Roldan, E

    2014-09-01

    This study investigated the bone of HIV patients both in terms of quantity and quality. It was found that HIV-infected patients did fracture independently of the degree of bone demineralization as in other forms of secondary osteoporosis. We aimed to determine the prevalence of vertebral fractures (VFs) in HIV patients who were screened by bone mineral density (BMD) and to explore possible factors associated with VFs. This is a cross-sectional study that included HIV-infected patients recruited in the Clinic of Infectious and Tropical Diseases and that underwent BMD measurement by dual-energy X-ray absorptiometry (DXA) at the lumbar spine and hip (Lunar Prodigy, GE Healthcare). For the assessment of VFs, anteroposterior and lateral X-ray examinations of the thoracic and lumbar spines were performed and were centrally digitized. Logistic regression models were used in the statistical analysis of factors associated with VFs. One hundred thirty-one consecutive patients with HIV infection (93 M, 38 F, median age 51 years; range, 36-75) underwent BMD measurement: 25.2 % of patients showed normal BMD, while 45 % were osteopenic and 29.7 % osteoporotic. Prevalence of low BMD (osteopenia and osteoporosis) was higher in females as compared to males (90 vs 69 %) with no significant correlation with age and body mass index. VFs occurred more frequently in patients with low BMD as compared to patients with normal BMD (88.5 vs. 11.4 %; p osteoporosis (43 vs. 46 %; p = 0.073). VFs were significantly associated with older age and previous AIDS events. These results suggest a BMD patients at risk of skeletal fragility and, therefore, good candidates for morphometric evaluation of spine X-ray in line with other forms of secondary osteoporosis with impaired bone quality.

  9. Evaluation of mandibular bone density to predict osteoporosis in adolescents with constitutional delayed growth

    International Nuclear Information System (INIS)

    Dural, Sema; Ozbek, Murat; Kanli, A.; Kanbur, Nuray O.; Derman, O.; Orhan, Kaan; Delilbasi, C.

    2005-01-01

    The aim of this study is to evaluate the correlation between constitutional delayed growth (CDG) and mandibular bone trabeculation as well as bone density on panoramic radiographs using a computer software program. Panoramic radiographs obtained from 25 patients with CDG and 25 healthy adolescents were evaluated for this study. Patients were selected from admission to Hacettepe University, Faculty of Medicine, Section of Adolescent Medicine in the first half of the year 2002. All panoramic radiographs were taken under standard conditions, and were randomized and then converted to digital images for density analysis using a scanner. The images were transferred to Osiris computer software program for the evaluation of bone density from 4 different regions on the mandible (right and left mandibular angle and condyle). The CDG group had higher values for the risk of osteoporosis considering the right (t=3.360, p=0.002) and the left condyle (t=3.620, p=0.001) (t-test for independent samples). It was also seen that the CDG group was again at higher risk in comparison to the control group when left mandibular angle values were measured (z= -2.447, p=0.014) (Mann Whitney - U test). We suggest that panoramic radiographs, which are transformed into digital format, can be valuable and economic tools for detecting the risk of osteoporosis in adolescents with CDG. (author)

  10. Bone mineral density predicts posttransplant survival among hepatocellular carcinoma liver transplant recipients.

    Science.gov (United States)

    Sharma, Pratima; Parikh, Neehar D; Yu, Jessica; Barman, Pranab; Derstine, Brian A; Sonnenday, Christopher J; Wang, Stewart C; Su, Grace L

    2016-08-01

    Hepatocellular carcinoma (HCC) is a common indication for liver transplantation (LT). Recent data suggest that body composition features strongly affect post-LT mortality. We examined the impact of body composition on post-LT mortality in patients with HCC. Data on adult LT recipients who received Model for End-Stage Liver Disease exception for HCC between February 29, 2002, and December 31, 2013, and who had a computed tomography (CT) scan any time 6 months prior to LT were reviewed (n = 118). All available CT scan Digital Imaging and Communication in Medicine files were analyzed using a semiautomated high throughput methodology with algorithms programmed in MATLAB. Analytic morphomics measurements including dorsal muscle group (DMG) area, visceral and subcutaneous fat, and bone mineral density (BMD) were taken at the bottom of the eleventh thoracic vertebral level. Thirty-two (27%) patients died during the median follow-up of 4.4 years. The number of HCC lesions (hazard ratio [HR], 2.81; P DMG area did not affect post-LT survival. In conclusion, in addition to number of HCC lesions and pre-LT locoregional therapy, low BMD, a surrogate for bone loss rather than DMG area, was independently associated with post-LT mortality in HCC patients. Bone loss may be an early marker of deconditioning that precedes sarcopenia and may affect transplant outcomes. Liver Transplantation 22 1092-1098 2016 AASLD. © 2016 American Association for the Study of Liver Diseases.

  11. A field method for soil erosion measurements in agricultural and natural lands

    Science.gov (United States)

    Y.P. Hsieh; K.T. Grant; G.C. Bugna

    2009-01-01

    Soil erosion is one of the most important watershed processes in nature, yet quantifying it under field conditions remains a challenge. The lack of soil erosion field data is a major factor hindering our ability to predict soil erosion in a watershed. We present here the development of a simple and sensitive field method that quantifies soil erosion and the resulting...

  12. Soil erosion assessment - Mind the gap

    Science.gov (United States)

    Kim, Jongho; Ivanov, Valeriy Y.; Fatichi, Simone

    2016-12-01

    Accurate assessment of erosion rates remains an elusive problem because soil loss is strongly nonunique with respect to the main drivers. In addressing the mechanistic causes of erosion responses, we discriminate between macroscale effects of external factors - long studied and referred to as "geomorphic external variability", and microscale effects, introduced as "geomorphic internal variability." The latter source of erosion variations represents the knowledge gap, an overlooked but vital element of geomorphic response, significantly impacting the low predictability skill of deterministic models at field-catchment scales. This is corroborated with experiments using a comprehensive physical model that dynamically updates the soil mass and particle composition. As complete knowledge of microscale conditions for arbitrary location and time is infeasible, we propose that new predictive frameworks of soil erosion should embed stochastic components in deterministic assessments of external and internal types of geomorphic variability.

  13. Numerical and experimental investigations on cavitation erosion

    Science.gov (United States)

    Fortes Patella, R.; Archer, A.; Flageul, C.

    2012-11-01

    A method is proposed to predict cavitation damage from cavitating flow simulations. For this purpose, a numerical process coupling cavitating flow simulations and erosion models was developed and applied to a two-dimensional (2D) hydrofoil tested at TUD (Darmstadt University of Technology, Germany) [1] and to a NACA 65012 tested at LMH-EPFL (Lausanne Polytechnic School) [2]. Cavitation erosion tests (pitting tests) were carried out and a 3D laser profilometry was used to analyze surfaces damaged by cavitation [3]. The method allows evaluating the pit characteristics, and mainly the volume damage rates. The paper describes the developed erosion model, the technique of cavitation damage measurement and presents some comparisons between experimental results and numerical damage predictions. The extent of cavitation erosion was correctly estimated in both hydrofoil geometries. The simulated qualitative influence of flow velocity, sigma value and gas content on cavitation damage agreed well with experimental observations.

  14. Airphoto analysis of erosion control practices

    Science.gov (United States)

    Morgan, K. M.; Morris-Jones, D. R.; Lee, G. B.; Kiefer, R. W.

    1980-01-01

    The Universal Soil Loss Equation (USLE) is a widely accepted tool for erosion prediction and conservation planning. In this study, airphoto analysis of color and color infrared 70 mm photography at a scale of 1:60,000 was used to determine the erosion control practice factor in the USLE. Information about contour tillage, contour strip cropping, and grass waterways was obtained from aerial photography for Pheasant Branch Creek watershed in Dane County, Wisconsin.

  15. Utilization of bone densitometry for prediction and administration of bisphosphonates to prevent osteoporosis in patients with prostate cancer without bone metastases receiving antiandrogen therapy

    International Nuclear Information System (INIS)

    Holt, Abby; Khan, Muhammad A; Gujja, Swetha; Govindarajan, Rangaswmy

    2014-01-01

    Prostate cancer subjects with prostate-specific antigen (PSA) relapse who are treated with androgen deprivation therapy (ADT) are recommended to have baseline and serial bone densitometry and receive bisphosphonates. The purpose of this community population study was to assess the utilization of bone densitometry and bisphosphonate therapy in men receiving ADT for non-metastatic prostate cancer. A cohort study of men aged 65 years or older with non-metastatic incident diagnoses of prostate cancer was obtained from the Surveillance Epidemiology End Results (SEER)-linked Medicare claims between 2004 and 2008. Claims were used to assess prescribed treatment of ADT, bone densitometry, and bisphosphonates. A total of 30,846 incident prostate cancer cases receiving ADT and aged 65 years or older had no bone metastases; 87.3% (n=26,935) on ADT did not receive either bone densitometry or bisphosphonate therapy. Three percent (n=931) of the cases on ADT received bisphosphonate therapy without ever receiving bone densitometry, 8.8% (n=2,702) of the cases on ADT received bone densitometry without receiving intravenous bisphosphonates, while nearly 1% (0.90%, n=278) of the cases on ADT received both bone densitometry and bisphosphonates. Analysis showed treatment differed by patient characteristics. Contrary to the recommendations, bone densitometry and bisphosphonate therapy are underutilized in men receiving ADT for non-metastatic prostate cancer

  16. Low urine pH and acid excretion do not predict bone fractures or the loss of bone mineral density: a prospective cohort study

    Directory of Open Access Journals (Sweden)

    Lyon Andrew W

    2010-05-01

    Full Text Available Abstract Background The acid-ash hypothesis, the alkaline diet, and related products are marketed to the general public. Websites, lay literature, and direct mail marketing encourage people to measure their urine pH to assess their health status and their risk of osteoporosis. The objectives of this study were to determine whether 1 low urine pH, or 2 acid excretion in urine [sulfate + chloride + 1.8x phosphate + organic acids] minus [sodium + potassium + 2x calcium + 2x magnesium mEq] in fasting morning urine predict: a fragility fractures; and b five-year change of bone mineral density (BMD in adults. Methods Design: Cohort study: the prospective population-based Canadian Multicentre Osteoporosis Study. Multiple logistic regression was used to examine associations between acid excretion (urine pH and urine acid excretion in fasting morning with the incidence of fractures (6804 person years. Multiple linear regression was used to examine associations between acid excretion with changes in BMD over 5-years at three sites: lumbar spine, femoral neck, and total hip (n = 651. Potential confounders controlled included: age, gender, family history of osteoporosis, physical activity, smoking, calcium intake, vitamin D status, estrogen status, medications, renal function, urine creatinine, body mass index, and change of body mass index. Results There were no associations between either urine pH or acid excretion and either the incidence of fractures or change of BMD after adjustment for confounders. Conclusion Urine pH and urine acid excretion do not predict osteoporosis risk.

  17. The Arctic Coastal Erosion Problem

    Energy Technology Data Exchange (ETDEWEB)

    Frederick, Jennifer M. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Thomas, Matthew Anthony [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Bull, Diana L. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Jones, Craig A. [Integral Consulting Inc., San Francisco, CA (United States); Roberts, Jesse D. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2016-09-01

    Permafrost-dominated coastlines in the Arctic are rapidly disappearing. Arctic coastal erosion rates in the United States have doubled since the middle of the twentieth century and appear to be accelerating. Positive erosion trends have been observed for highly-variable geomorphic conditions across the entire Arctic, suggesting a major (human-timescale) shift in coastal landscape evolution. Unfortunately, irreversible coastal land loss in this region poses a threat to native, industrial, scientific, and military communities. The Arctic coastline is vast, spanning more than 100,000 km across eight nations, ten percent of which is overseen by the United States. Much of area is inaccessible by all-season roads. People and infrastructure, therefore, are commonly located near the coast. The impact of the Arctic coastal erosion problem is widespread. Homes are being lost. Residents are being dispersed and their villages relocated. Shoreline fuel storage and delivery systems are at greater risk. The U.S. Department of Energy (DOE) and Sandia National Laboratories (SNL) operate research facilities along some of the most rapidly eroding sections of coast in the world. The U.S. Department of Defense (DOD) is struggling to fortify coastal radar sites, operated to ensure national sovereignty in the air, against the erosion problem. Rapid alterations to the Arctic coastline are facilitated by oceanographic and geomorphic perturbations associated with climate change. Sea ice extent is declining, sea level is rising, sea water temperature is increasing, and permafrost state is changing. The polar orientation of the Arctic exacerbates the magnitude and rate of the environmental forcings that facilitate coastal land area loss. The fundamental mechanics of these processes are understood; their non-linear combination poses an extreme hazard. Tools to accurately predict Arctic coastal erosion do not exist. To obtain an accurate predictive model, a coupling of the influences of

  18. Soil erosion predictions from a landscape evolution model - An assessment of a post-mining landform using spatial climate change analogues.

    Science.gov (United States)

    Hancock, G R; Verdon-Kidd, D; Lowry, J B C

    2017-12-01

    Landscape Evolution Modelling (LEM) technologies provide a means by which it is possible to simulate the long-term geomorphic stability of a conceptual rehabilitated landform. However, simulations rarely consider the potential effects of anthropogenic climate change and consequently risk not accounting for the range of rainfall variability that might be expected in both the near and far future. One issue is that high resolution (both spatial and temporal) rainfall projections incorporating the potential effects of greenhouse forcing are required as input. However, projections of rainfall change are still highly uncertain for many regions, particularly at sub annual/seasonal scales. This is the case for northern Australia, where a decrease or an increase in rainfall post 2030 is considered equally likely based on climate model simulations. The aim of this study is therefore to investigate a spatial analogue approach to develop point scale hourly rainfall scenarios to be used as input to the CAESAR - Lisflood LEM to test the sensitivity of the geomorphic stability of a conceptual rehabilitated landform to potential changes in climate. Importantly, the scenarios incorporate the range of projected potential increase/decrease in rainfall for northern Australia and capture the expected envelope of erosion rates and erosion patterns (i.e. where erosion and deposition occurs) over a 100year modelled period. We show that all rainfall scenarios produce sediment output and gullying greater than that of the surrounding natural system, however a 'wetter' future climate produces the highest output. Importantly, incorporating analogue rainfall scenarios into LEM has the capacity to both improve landform design and enhance the modelling software. Further, the method can be easily transferred to other sites (both nationally and internationally) where rainfall variability is significant and climate change impacts are uncertain. Crown Copyright © 2017. Published by Elsevier B.V. All

  19. Finite element method for one-dimensional rill erosion simulation on a curved slope

    Directory of Open Access Journals (Sweden)

    Lijuan Yan

    2015-03-01

    Full Text Available Rill erosion models are important to hillslope soil erosion prediction and to land use planning. The development of rill erosion models and their use has become increasingly of great concern. The purpose of this research was to develop mathematic models with computer simulation procedures to simulate and predict rill erosion. The finite element method is known as an efficient tool in many other applications than in rill soil erosion. In this study, the hydrodynamic and sediment continuity model equations for a rill erosion system were solved by the Galerkin finite element method and Visual C++ procedures. The simulated results are compared with the data for spatially and temporally measured processes for rill erosion under different conditions. The results indicate that the one-dimensional linear finite element method produced excellent predictions of rill erosion processes. Therefore, this study supplies a tool for further development of a dynamic soil erosion prediction model.

  20. Regionalization of monthly rainfall erosivity patternsin Switzerland

    Science.gov (United States)

    Schmidt, Simon; Alewell, Christine; Panagos, Panos; Meusburger, Katrin

    2016-10-01

    One major controlling factor of water erosion is rainfall erosivity, which is quantified as the product of total storm energy and a maximum 30 min intensity (I30). Rainfall erosivity is often expressed as R-factor in soil erosion risk models like the Universal Soil Loss Equation (USLE) and its revised version (RUSLE). As rainfall erosivity is closely correlated with rainfall amount and intensity, the rainfall erosivity of Switzerland can be expected to have a regional characteristic and seasonal dynamic throughout the year. This intra-annual variability was mapped by a monthly modeling approach to assess simultaneously spatial and monthly patterns of rainfall erosivity. So far only national seasonal means and regional annual means exist for Switzerland. We used a network of 87 precipitation gauging stations with a 10 min temporal resolution to calculate long-term monthly mean R-factors. Stepwise generalized linear regression (GLM) and leave-one-out cross-validation (LOOCV) were used to select spatial covariates which explain the spatial and temporal patterns of the R-factor for each month across Switzerland. The monthly R-factor is mapped by summarizing the predicted R-factor of the regression equation and the corresponding residues of the regression, which are interpolated by ordinary kriging (regression-kriging). As spatial covariates, a variety of precipitation indicator data has been included such as snow depths, a combination product of hourly precipitation measurements and radar observations (CombiPrecip), daily Alpine precipitation (EURO4M-APGD), and monthly precipitation sums (RhiresM). Topographic parameters (elevation, slope) were also significant explanatory variables for single months. The comparison of the 12 monthly rainfall erosivity maps showed a distinct seasonality with the highest rainfall erosivity in summer (June, July, and August) influenced by intense rainfall events. Winter months have the lowest rainfall erosivity. A proportion of 62 % of

  1. Advances in modeling soil erosion after disturbance on rangelands

    Science.gov (United States)

    Research has been undertaken to develop process based models that predict soil erosion rate after disturbance on rangelands. In these models soil detachment is predicted as a combination of multiple erosion processes, rain splash and thin sheet flow (splash and sheet) detachment and concentrated flo...

  2. Kinetics of gene expression and bone remodelling in the clinical phase of collagen induced arthritis

    DEFF Research Database (Denmark)

    Denninger, Katja Caroline Marie; Litman, Thomas; Marstrand, Troels

    2015-01-01

    Introduction: Pathological bone changes differ considerably between inflammatory arthritic diseases and most studies have focused on bone erosion. Collagen-induced arthritis (CIA) is a model for rheumatoid arthritis, which, in addition to bone erosion, demonstrates bone formation at the time...

  3. Protection from erosion following wildfire

    Science.gov (United States)

    Peter R. Robichaud; William J. Elliot

    2006-01-01

    Erosion in the first year after a wildfire can be up to three orders of magnitude greater than the erosion from undisturbed forests. To mitigate potential postfire erosion, various erosion control treatments are applied on highly erodible areas with downstream resources in need of protection. Because postfire erosion rates generally decline by an order of magnitude for...

  4. Development of a Nomogram Model Predicting Current Bone Scan Positivity in Patients Treated with Androgen-Deprivation Therapy for Prostate Cancer

    Science.gov (United States)

    Gotto, Geoffrey T.; Yu, Changhong; Bernstein, Melanie; Eastham, James A.; Kattan, Michael W.

    2014-01-01

    Purpose: To develop a nomogram predictive of current bone scan positivity in patients receiving androgen-deprivation therapy (ADT) for advanced prostate cancer; to augment clinical judgment and highlight patients in need of additional imaging investigations. Materials and methods: A retrospective chart review of bone scan records (conventional 99mTc-scintigraphy) of 1,293 patients who received ADT at the Memorial Sloan-Kettering Cancer Center from 2000 to 2011. Multivariable logistic regression analysis was used to identify variables suitable for inclusion in the nomogram. The probability of current bone scan positivity was determined using these variables and the predictive accuracy of the nomogram was quantified by concordance index. Results: In total, 2,681 bone scan records were analyzed and 636 patients had a positive result. Overall, the median pre-scan prostate-specific antigen (PSA) level was 2.4 ng/ml; median PSA doubling time (PSADT) was 5.8 months. At the time of a positive scan, median PSA level was 8.2 ng/ml; 53% of patients had PSA <10 ng/ml; median PSADT was 4.0 months. Five variables were included in the nomogram: number of previous negative bone scans after initiating ADT, PSA level, Gleason grade sum, and history of radical prostatectomy and radiotherapy. A concordance index value of 0.721 was calculated for the nomogram. This was a retrospective study based on limited data in patients treated in a large cancer center who underwent conventional 99mTc bone scans, which themselves have inherent limitations. Conclusion: This is the first nomogram to predict current bone scan positivity in ADT-treated prostate cancer patients, providing high predictive accuracy. PMID:25386410

  5. Development of a nomogram model predicting current bone scan positivity in patients treated with androgen-deprivation therapy for prostate cancer

    Directory of Open Access Journals (Sweden)

    Michael eKattan

    2014-10-01

    Full Text Available Purpose: To develop a nomogram predictive of current bone scan positivity in patients receiving androgen-deprivation therapy (ADT for advanced prostate cancer; to augment clinical judgment and highlight patients in need of additional imaging investigations.Materials and Methods: A retrospective chart review of bone scan records (conventional 99mTc-scintigraphy of 1,293 patients who received ADT at the Memorial Sloan-Kettering Cancer Center from 2000 to 2011. Multivariable logistic regression analysis was used to identify variables suitable for inclusion in the nomogram. The probability of current bone scan positivity was determined using these variables and the predictive accuracy of the nomogram was quantified by concordance index.Results: In total, 2,681 bone scan records were analyzed and 636 patients had a positive result. Overall, the median pre-scan prostate-specific antigen (PSA level was 2.4 ng/ml; median PSA doubling time (PSADT was 5.8 months. At the time of a positive scan, median PSA level was 8.2 ng/ml; 53% of patients had PSA <10 ng/ml; median PSADT was 4.0 months. Five variables were included in the nomogram: number of previous negative bone scans after initiating ADT, PSA level, Gleason grade sum, and history of radical prostatectomy and radiotherapy. A concordance index value of 0.721 was calculated for the nomogram. This was a retrospective study based on limited data in patients treated in a large cancer centre who underwent conventional 99mTc bone scans, which themselves have inherent limitations. Conclusions: This is the first nomogram to predict current bone scan positivity in ADT-treated prostate cancer patients, providing high predictive accuracy.

  6. Erosion and stability of a mine soil

    International Nuclear Information System (INIS)

    Wu, T.H.; Stadler, A.T.; Low, C.

    1996-01-01

    Mine soils developed from mine spoils commonly have a wide range of particle size. The slopes of old spoil piles usually are marked by gullies due to years of uncontrolled erosion. These characteristics raise questions about applicability of available theories and models for estimating runoff and erosion. An investigation was made to determine whether available erosion models can work for mine soils and can account for gully erosion. The investigation at an abandoned surface mine consisted of measurement of soil and sediment properties, measurement of runoff and erosion, observations of armor by rock fragments on gully floor, and calculations with available theories of sediment transport and slope stability. The results at this site suggest that (1) predictions with the ANSWERS model have about the same accuracy as those made for agricultural lands; (2) armor provided by rock fragments are temporary as they are periodically removed by debris flows; (3) detachment by rainfall impact is the primary cause of erosion on short steep slopes; and (4) a simplified method can be used for estimating erosion on such slopes

  7. Saliva and dental erosion

    Directory of Open Access Journals (Sweden)

    Marília Afonso Rabelo Buzalaf

    2012-10-01

    Full Text Available Dental erosion is a multifactorial condition. The consideration of chemical, biological and behavioral factors is fundamental for its prevention and therapy. Among the biological factors, saliva is one of the most important parameters in the protection against erosive wear. Objective: This review discusses the role of salivary factors on the development of dental erosion. Material and Methods: A search was undertaken on MeDLINe website for papers from 1969 to 2010. The keywords used in the research were "saliva", "acquired pellicle", "salivary flow", "salivary buffering capacity" and "dental erosion". Inclusion of studies, data extraction and quality assessment were undertaken independently and in duplicate by two members of the review team. Disagreements were solved by discussion and consensus or by a third party. Results: Several characteristics and properties of saliva play an important role in dental erosion. Salivary clearance gradually eliminates the acids through swallowing and saliva presents buffering capacity causing neutralization and buffering of dietary acids. Salivary flow allows dilution of the acids. In addition, saliva is supersaturated with respect to tooth mineral, providing calcium, phosphate and fluoride necessary for remineralization after an erosive challenge. Furthermore, many proteins present in saliva and acquired pellicle play an important role in dental erosion. Conclusions: Saliva is the most important biological factor affecting the progression of dental erosion. Knowledge of its components and properties involved in this protective role can drive the development of preventive measures targeting to enhance its known beneficial effects.

  8. Scales and erosion

    Science.gov (United States)

    There is a need to develop scale explicit understanding of erosion to overcome existing conceptual and methodological flaws in our modelling methods currently applied to understand the process of erosion, transport and deposition at the catchment scale. These models need to be based on a sound under...

  9. Saliva and dental erosion.

    Science.gov (United States)

    Buzalaf, Marília Afonso Rabelo; Hannas, Angélicas Reis; Kato, Melissa Thiemi

    2012-01-01

    Dental erosion is a multifactorial condition. The consideration of chemical, biological and behavioral factors is fundamental for its prevention and therapy. Among the biological factors, saliva is one of the most important parameters in the protection against erosive wear. This review discusses the role of salivary factors on the development of dental erosion. A search was undertaken on MeDLINe website for papers from 1969 to 2010. The keywords used in the research were "saliva", "acquired pellicle", "salivary flow", "salivary buffering capacity" and "dental erosion". Inclusion of studies, data extraction and quality assessment were undertaken independently and in duplicate by two members of the review team. Disagreements were solved by discussion and consensus or by a third party. Several characteristics and properties of saliva play an important role in dental erosion. Salivary clearance gradually eliminates the acids through swallowing and saliva presents buffering capacity causing neutralization and buffering of dietary acids. Salivary flow allows dilution of the acids. In addition, saliva is supersaturated with respect to tooth mineral, providing calcium, phosphate and fluoride necessary for remineralization after an erosive challenge. Furthermore, many proteins present in saliva and acquired pellicle play an important role in dental erosion. Saliva is the most important biological factor affecting the progression of dental erosion. Knowledge of its components and properties involved in this protective role can drive the development of preventive measures targeting to enhance its known beneficial effects.

  10. Mapping monthly rainfall erosivity in Europe.

    Science.gov (United States)

    Ballabio, Cristiano; Borrelli, Pasquale; Spinoni, Jonathan; Meusburger, Katrin; Michaelides, Silas; Beguería, Santiago; Klik, Andreas; Petan, Sašo; Janeček, Miloslav; Olsen, Preben; Aalto, Juha; Lakatos, Mónika; Rymszewicz, Anna; Dumitrescu, Alexandru; Tadić, Melita Perčec; Diodato, Nazzareno; Kostalova, Julia; Rousseva, Svetla; Banasik, Kazimierz; Alewell, Christine; Panagos, Panos

    2017-02-01

    Rainfall erosivity as a dynamic factor of soil loss by water erosion is modelled intra-annually for the first time at European scale. The development of Rainfall Erosivity Database at European Scale (REDES) and its 2015 update with the extension to monthly component allowed to develop monthly and seasonal R-factor maps and assess rainfall erosivity both spatially and temporally. During winter months, significant rainfall erosivity is present only in part of the Mediterranean countries. A sudden increase of erosivity occurs in major part of European Union (except Mediterranean basin, western part of Britain and Ireland) in May and the highest values are registered during summer months. Starting from September, R-factor has a decreasing trend. The mean rainfall erosivity in summer is almost 4 times higher (315MJmmha -1 h -1 ) compared to winter (87MJmmha -1 h -1 ). The Cubist model has been selected among various statistical models to perform the spatial interpolation due to its excellent performance, ability to model non-linearity and interpretability. The monthly prediction is an order more difficult than the annual one as it is limited by the number of covariates and, for consistency, the sum of all months has to be close to annual erosivity. The performance of the Cubist models proved to be generally high, resulting in R 2 values between 0.40 and 0.64 in cross-validation. The obtained months show an increasing trend of erosivity occurring from winter to summer starting from western to Eastern Europe. The maps also show a clear delineation of areas with different erosivity seasonal patterns, whose spatial outline was evidenced by cluster analysis. The monthly erosivity maps can be used to develop composite indicators that map both intra-annual variability and concentration of erosive events. Consequently, spatio-temporal mapping of rainfall erosivity permits to identify the months and the areas with highest risk of soil loss where conservation measures should be

  11. Combining areal DXA bone mineral density and vertebrae postero-anterior width improves the prediction of vertebral strength

    Energy Technology Data Exchange (ETDEWEB)

    Taton, Grzegorz; Rokita, Eugeniusz [Jagiellonian University Medical College, Department of Biophysics, Krakow (Poland); Wrobel, Andrzej [Jagiellonian University, Institute of Physics, Krakow (Poland); Korkosz, Mariusz [Jagiellonian University Medical College, Department of Internal Medicine and Gerontology, Division of Rheumatology, Krakow (Poland)

    2013-12-15

    Areal bone mineral density (aBMD) measured by dual-energy X-ray absorptiometry (DXA) is an important determinant of bone strength (BS), despite the fact that the correlation between aBMD and BS is relatively weak. Parameters that describe BS more accurately are desired. The aim of this study was to determine whether the geometrical corrections applied to aBMD would improve its ability for BS prediction. We considered new parameters, estimated from a single DXA measurement, as well as BMAD (bone mineral apparent density) reported in the literature. In vitro studies were performed with the L3 vertebrae from 20 cadavers, which were studied with DXA and quantitative computed tomography (QCT). A mechanical strength assessment was carried out. Two new parameters were introduced: vBMD{sub min} = (aBMD)/(W{sub PA}{sup min}) and vBMD{sub av} = (aBMD)/(W{sub PA}{sup av}) (W{sub PA}{sup min} - minimal vertebral body width in postero-anterior (PA) view, W{sub PA}{sup av} - average PA vertebral body width). Volumetric BMD measured by QCT (vBMD), aBMD, BMAD, vBMD{sub min}, and vBMD{sub av} were correlated to ultimate load and ultimate stress (P{sub max}) to find the best predictor of vertebrae BS. The coefficients of correlation between P{sub max} and vBMD{sub min}, vBMD{sub av}, as well as BMAD, were r = 0.626 (p = 0.005), r = 0.610 (p = 0.006) and r = 0.567 (p = 0.012), respectively. Coefficients for vBMD and aBMD are r = 0.648 (p = 0.003) and r = 0.511 (p = 0.03), respectively. Our results showed that aBMD normalized by vertebrae dimensions describes vertebrae BS better than aBMD alone. The considered indices vBMD{sub av}, vBMD{sub min}, and BMAD can be measured in routine PA DXA and considerably improve BS variability prediction. vBMD{sub min} is superior compared to vBMD{sub av} and BMAD. (orig.)

  12. Fracture Risk Prediction Using Phalangeal Bone Mineral Density or FRAX(®)?

    DEFF Research Database (Denmark)

    Friis-Holmberg, Teresa; Rubin, Katrine Hass; Brixen, Kim

    2014-01-01

    the association between low, intermediate, and high risk by phalangeal T-score or FRAX and incident fractures, and receiver operating characteristic curves were obtained. Mean follow-up time was 4.3 yr, and a total of 395 persons (3.1%) experienced a fracture during follow-up. The highest rate of major...... variables performed overall best in the prediction of major osteoporotic fractures. In predicting hip fractures, there was a tendency of T-score performing worse than the other methods....

  13. Evaluation of the pepsin digestibility assay for predicting amino acid digestibility of meat and bone meals.

    Science.gov (United States)

    Davis, T M; Parsons, C M; Utterback, P L; Kirstein, D

    2015-05-01

    Sixteen meat and bone meal (MBM) samples were obtained and selected from various company plants to provide a wide range in pepsin nitrogen digestibility values. Pepsin digestibility was determined using either 0.02 or 0.002% pepsin. Amino acid (AA) digestibility of the 16 MBM samples was then determined using a precision-fed cecectomized rooster assay. The 0.02% pepsin digestibility values were numerically higher than the 0.002% pepsin values. The values varied from 77 to 93% for 0.02% pepsin and from 67 to 91% for 0.002% pepsin. The rooster AA digestibility results showed a wide range of values among MBM samples mostly due to the 4 samples having lowest and highest AA digestibility. A precision-fed broiler chick ileal AA digestibility assay confirmed that there were large differences in AA digestibility among the MBM samples having the lowest and highest rooster digestibility values. Correlation analyses between pepsin and AA digestibility values showed that the correlation values (r) were highly significant (P digestibility values were not included in the correlation analyses, the correlation coefficient values (r) were generally very low and not significant (P > 0.05). The results indicated that the pepsin nitrogen digestibility assay is only useful for detecting large differences in AA digestibility among MBM. There also was no advantage for using 0.02 versus 0.002% pepsin. © 2015 Poultry Science Association Inc.

  14. Premature hair greying may predict reduced bone mineral density in Graves' disease.

    LENUS (Irish Health Repository)

    Leary, A C

    2012-02-03

    BACKGROUND: Premature hair greying has been associated with low bone mineral density (BMD), and it may be more frequent in Graves\\' disease. AIMS: To determine whether premature greying is associated with reduced BMD in women with Graves\\' disease and in control women, and to examine whether premature greying is more common in Graves\\' disease. METHODS: Premature greying (> 50% grey by 40 years) and BMD were determined in 44 women with a history of Graves\\' disease and 133 female controls referred for routine BMD measurement. Exclusion criteria included diseases or drugs known to affect BMD. RESULTS: Mean Z and T scores at the lumbar spine were significantly lower (P < 0.04) in subjects with premature greying than in those not prematurely grey among women with Graves\\' disease, but not among control women. Multiple regression confirmed this difference between Graves\\' and control women (P = 0.041). There were no differences at other measurement sites. Of Graves\\' patients, 36% were prematurely grey compared with 25% of control women (P = 0.14). CONCLUSION: Premature greying may be a weak marker for reduced BMD in women with a history of Graves\\' disease, but it is not a marker in normal women.

  15. Utility of the immature platelet fraction in pediatric immune thrombocytopenia: Differentiating from bone marrow failure and predicting bleeding risk.

    Science.gov (United States)

    McDonnell, Alicia; Bride, Karen L; Lim, Derick; Paessler, Michele; Witmer, Char M; Lambert, Michele P

    2018-02-01

    Differentiating childhood immune thrombocytopenia (ITP) from other cause of thrombocytopenia remains a diagnosis of exclusion. Additionally factors that predict bleeding risk for those patients with ITP are currently not well understood. Previous small studies have suggested that immature platelet fraction (IPF) may differentiate ITP from other causes of thrombocytopenia and in combination with other factors may predict bleeding risk. We performed a retrospective chart review of thrombocytopenic patients with an IPF measured between November 1, 2013 and July 1, 2015. Patients were between 2 months and 21 years of age with a platelet count bleeding symptoms. A bleeding severity score was retrospectively assigned. Two hundred seventy two patients met inclusion criteria, 97 with ITP, 11 with bone marrow failure (BMF), 126 with malignancy, and 38 with other causes of thrombocytopenia. An IPF > 5.2% differentiated ITP from BMF with 93% sensitivity and 91% specificity. Absolute immature platelet number (AIPN) was significantly lower in ITP patients with severe to life-threatening hemorrhage than those without, despite similar platelet counts. On multivariate analysis, an IPF bleeding risk at platelet counts <10 × 10 9 /l in patients with ITP. IPF measurement alone has utility in both the diagnosis of ITP and identifying patients at increased risk of hemorrhage. Further study is required to understand the pathophysiological differences of ITP patients with lower IPF/AIPN. © 2017 Wiley Periodicals, Inc.

  16. Optimization the Initial Weights of Artificial Neural Networks via Genetic Algorithm Applied to Hip Bone Fracture Prediction

    Directory of Open Access Journals (Sweden)

    Yu-Tzu Chang

    2012-01-01

    Full Text Available This paper aims to find the optimal set of initial weights to enhance the accuracy of artificial neural networks (ANNs by using genetic algorithms (GA. The sample in this study included 228 patients with first low-trauma hip fracture and 215 patients without hip fracture, both of them were interviewed with 78 questions. We used logistic regression to select 5 important factors (i.e., bone mineral density, experience of fracture, average hand grip strength, intake of coffee, and peak expiratory flow rate for building artificial neural networks to predict the probabilities of hip fractures. Three-layer (one hidden layer ANNs models with back-propagation training algorithms were adopted. The purpose in this paper is to find the optimal initial weights of neural networks via genetic algorithm to improve the predictability. Area under the ROC curve (AUC was used to assess the performance of neural networks. The study results showed the genetic algorithm obtained an AUC of 0.858±0.00493 on modeling data and 0.802 ± 0.03318 on testing data. They were slightly better than the results of our previous study (0.868±0.00387 and 0.796±0.02559, resp.. Thus, the preliminary study for only using simple GA has been proved to be effective for improving the accuracy of artificial neural networks.

  17. Bone mineral density test

    Science.gov (United States)

    BMD test; Bone density test; Bone densitometry; DEXA scan; DXA; Dual-energy x-ray absorptiometry; p-DEXA; Osteoporosis - BMD ... need to undress. This scan is the best test to predict your risk of fractures, especially of ...

  18. A comparison of artificial neural networks with other statistical approaches for the prediction of true metabolizable energy of meat and bone meal.

    Science.gov (United States)

    Perai, A H; Nassiri Moghaddam, H; Asadpour, S; Bahrampour, J; Mansoori, Gh

    2010-07-01

    There has been a considerable and continuous interest to develop equations for rapid and accurate prediction of the ME of meat and bone meal. In this study, an artificial neural network (ANN), a partial least squares (PLS), and a multiple linear regression (MLR) statistical method were used to predict the TME(n) of meat and bone meal based on its CP, ether extract, and ash content. The accuracy of the models was calculated by R(2) value, MS error, mean absolute percentage error, mean absolute deviation, bias, and Theil's U. The predictive ability of an ANN was compared with a PLS and a MLR model using the same training data sets. The squared regression coefficients of prediction for the MLR, PLS, and ANN models were 0.38, 0.36, and 0.94, respectively. The results revealed that ANN produced more accurate predictions of TME(n) as compared with PLS and MLR methods. Based on the results of this study, ANN could be used as a promising approach for rapid prediction of nutritive value of meat and bone meal.

  19. Bone tumor

    Science.gov (United States)

    Tumor - bone; Bone cancer; Primary bone tumor; Secondary bone tumor; Bone tumor - benign ... The cause of bone tumors is unknown. They often occur in areas of the bone that grow rapidly. Possible causes include: Genetic defects ...

  20. Dose-volume effects for pelvic bone marrow in predicting hematological toxicity in prostate cancer radiotherapy with pelvic node irradiation.

    Science.gov (United States)

    Sini, Carla; Fiorino, Claudio; Perna, Lucia; Noris Chiorda, Barbara; Deantoni, Chiara Lucrezia; Bianchi, Marco; Sacco, Vincenzo; Briganti, Alberto; Montorsi, Francesco; Calandrino, Riccardo; Di Muzio, Nadia; Cozzarini, Cesare

    2016-01-01

    To prospectively identify clinical/dosimetric predictors of acute/late hematologic toxicity (HT) in chemo-naÏve patients treated with whole-pelvis radiotherapy (WPRT) for prostate cancer. Data of 121 patients treated with adjuvant/salvage WPRT were analyzed (static-field IMRT n=19; VMAT/Rapidarc n=57; Tomotherapy n=45). Pelvic bone marrow (BM) was delineated as ilium (IL), lumbosacral, lower and whole pelvis (WP), and the relative DVHs were calculated. HT was graded both according to CTCAE v4.03 and as variation in percentage relative to baseline. Logistic regression was used to analyze association between HT and clinical/DVHs factors. Significant differences (p<0.005) in the DVH of BM volumes between different techniques were found: Tomotherapy was associated with larger volumes receiving low doses (3-20 Gy) and smaller receiving 40-50 Gy. Lower baseline absolute values of WBC, neutrophils and lymphocytes (ALC) predicted acute/late HT (p ⩽ 0.001). Higher BM V40 was associated with higher risk of acute Grade3 (OR=1.018) or late Grade2 lymphopenia (OR=1.005). Two models predicting lymphopenia were developed, both including baseline ALC, and BM WP-V40 (AUC=0.73) and IL-V40+smoking (AUC=0.904) for acute/late respectively. Specific regions of pelvic BM predicting acute/late lymphopenia, a risk factor for viral infections, were identified. The 2-variable models including specific constraints to BM may help reduce HT. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  1. TH and DCX mRNAs in peripheral blood and bone marrow predict outcome in metastatic neuroblastoma patients.

    Science.gov (United States)

    Yáñez, Yania; Hervás, David; Grau, Elena; Oltra, Silvestre; Pérez, Gema; Palanca, Sarai; Bermúdez, Mar; Márquez, Catalina; Cañete, Adela; Castel, Victoria

    2016-03-01

    In metastatic neuroblastoma (NB) patients, accurate risk stratification and disease monitoring would reduce relapse probabilities. This study aims to evaluate the independent prognostic significance of detecting tyrosine hydroxylase (TH) and doublecortin (DCX) mRNAs by reverse transcriptase quantitative polymerase chain reaction (RT-qPCR) in peripheral blood (PB) and bone marrow (BM) samples from metastatic NB patients. RT-qPCR was performed on PB and BM samples from metastatic NB patients at diagnosis, post-induction therapy and at the end of treatment for TH and DCX mRNAs detection. High levels of TH and DCX mRNAs when detected in PB and BM at diagnosis independently predicted worse outcome in a cohort of 162 metastatic NB. In the subgroup of high-risk metastatic NB, TH mRNA detected in PB remained as independent predictor of EFS and OS at diagnosis. After the induction therapy, high levels of TH mRNA in PB and DCX mRNA in BM independently predicted poor EFS and OS. Furthermore TH mRNA when detected in BM predicted worse EFS. TH mRNA in PB samples at the end of treatment is an independent predictor of worse outcome. TH and DCX mRNAs levels in PB and BM assessed by RT-qPCR should be considered in new pre-treatment risk stratification strategies to reliable estimate outcome differences in metastatic NB patients. In those high-risk metastatic NB, TH and DCX mRNA quantification could be used for the assessment of response to treatment and for early detection of progressive disease or relapses.

  2. Numerical modelling of concentrated leak erosion during Hole Erosion Tests

    OpenAIRE

    Mercier, F.; Bonelli, S.; Golay, F.; Anselmet, F.; Philippe, P.; Borghi, R.

    2015-01-01

    This study focuses on the numerical modelling of concentrated leak erosion of a cohesive soil by a turbulent flow in axisymmetrical geometry, with application to the Hole Erosion Test (HET). The numerical model is based on adaptive remeshing of the water/soil interface to ensure accurate description of the mechanical phenomena occurring near the soil/water interface. The erosion law governing the interface motion is based on two erosion parameters: the critical shear stress and the erosion co...

  3. Combination of prostate specific antigen and pathological stage regarding to gleason score to predict bone metastasis of newly diagnosed prostate cancer

    International Nuclear Information System (INIS)

    Wang Zhen; Zhou Liquan; Gao Jiangping; Shi Lixin; Zhao Xiaoyi; Hong Baofa

    2004-01-01

    To determine the value of tumor grade and serum prostate-specific antigen in predicting skeletal metastases in untreated prostate cancer, the results of bone scans were related retrospectively to levels of serum PSA and tumor Grade based on pathologyical examination in 202 patients with prostate cancer newly diagnosed. Skeletal metastases were present in 7% of patients with serum PSA 100 μg/L. Bone scans are omitted likely in a man newly diagnosed with prostate cancer who has no suggestive clinical features, a serum PSA 100 μg/L. (authors)

  4. Predictive factors for the presence of tumor cells in bone marrow and peripheral blood in breast cancer patients.

    Science.gov (United States)

    Cabinakova, M; Mikulova, V; Malickova, K; Vrana, D; Pavlista, D; Petruzelka, L; Zima, T; Tesarova, P

    2015-01-01

    Simultaneous detection of disseminated tumor cells (DTCs) and circulating tumor cells (CTCs) was shown to be associated with an especially poor prognosis and increased incidence of disease-related deaths in non-metastatic breast cancer patients. We analyzed the occurance of DTCs and CTCs in patients with primary breast cancer and evaluated the correlation of their presence with other prognostic markers and investigated the changes in DTCs/CTCs number at different time points during treatment.Blood of 50 patients with primary breast cancer were used for immunomagnetic separation and detection of circulating tumor cells using the commercial available system the AdnaTest Breast Cancer™ (AdnaGen GmbH, Langenhagen, Germany). Bone marrow aspirates from 50 patients were analyzed for DTCs by immunocytochemistry using the pan-cytokeratin antibody conjugated with FITC (Monoclonal Anti-Cytokeratin antibody F3418, Sigma Aldrich).DTCs were identified in 30% (15/50) and CTCs in 22% (11/50) of patients. We found that DTC positivity could point to a significantly high risk of larger primary tumor size (p-value 0.011) and significantly higher risk of lymph node involvement (p-value 0.002). For CTC positivity, no such relationship was proven. DTCs have shown significantly higher prevalence in ER/PR-negative females and in HER2-positive cases. CTCs were equally prevalent in patients with the presence and absence of standard prognostic and predictive markers such as ER, PR and HER2. We found no correlation between CTCs and DTCs findings (r = -0.097, p = 0.504). We used DTCs/CTCs analysis for therapy monitoring in a small group of 29 patients, who underwent neoadjuvant chemotherapy (NACT). We find out no significant correlation between DTCs/CTCs detection and the primary tumor response to NACT. A pathologic complete response (pCR) was achieved by 31% (9/29) of the patients in our study, however, no association was observed between pCR and the detection of DTCs after NACT

  5. Modeling soil erosion and transport on forest landscape

    Science.gov (United States)

    Ge Sun; Steven G McNulty

    1998-01-01

    Century-long studies on the impacts of forest management in North America suggest sediment can cause major reduction on stream water quality. Soil erosion patterns in forest watersheds are patchy and heterogeneous. Therefore, patterns of soil erosion are difficult to model and predict. The objective of this study is to develop a user friendly management tool for land...

  6. Rainfall erosivity in Europe.

    Science.gov (United States)

    Panagos, Panos; Ballabio, Cristiano; Borrelli, Pasquale; Meusburger, Katrin; Klik, Andreas; Rousseva, Svetla; Tadić, Melita Perčec; Michaelides, Silas; Hrabalíková, Michaela; Olsen, Preben; Aalto, Juha; Lakatos, Mónika; Rymszewicz, Anna; Dumitrescu, Alexandru; Beguería, Santiago; Alewell, Christine

    2015-04-01

    Rainfall is one the main drivers of soil erosion. The erosive force of rainfall is expressed as rainfall erosivity. Rainfall erosivity considers the rainfall amount and intensity, and is most commonly expressed as the R-factor in the USLE model and its revised version, RUSLE. At national and continental levels, the scarce availability of data obliges soil erosion modellers to estimate this factor based on rainfall data with only low temporal resolution (daily, monthly, annual averages). The purpose of this study is to assess rainfall erosivity in Europe in the form of the RUSLE R-factor, based on the best available datasets. Data have been collected from 1541 precipitation stations in all European Union (EU) Member States and Switzerland, with temporal resolutions of 5 to 60 min. The R-factor values calculated from precipitation data of different temporal resolutions were normalised to R-factor values with temporal resolutions of 30 min using linear regression functions. Precipitation time series ranged from a minimum of 5 years to a maximum of 40 years. The average time series per precipitation station is around 17.1 years, the most datasets including the first decade of the 21st century. Gaussian Process Regression (GPR) has been used to interpolate the R-factor station values to a European rainfall erosivity map at 1 km resolution. The covariates used for the R-factor interpolation were climatic data (total precipitation, seasonal precipitation, precipitation of driest/wettest months, average temperature), elevation and latitude/longitude. The mean R-factor for the EU plus Switzerland is 722 MJ mm ha(-1) h(-1) yr(-1), with the highest values (>1000 MJ mm ha(-1) h(-1) yr(-1)) in the Mediterranean and alpine regions and the lowest (<500 MJ mm ha(-1) h(-1) yr(-1)) in the Nordic countries. The erosivity density (erosivity normalised to annual precipitation amounts) was also the highest in Mediterranean regions which implies high risk for erosive events and floods

  7. Mapping Soil Erosion Factors and Potential Erosion Risk for the National Park "Central Balkan"

    Science.gov (United States)

    Ilieva, Diliana; Malinov, Ilia

    2014-05-01

    Soil erosion is widely recognised environmental problem. The report aims at presenting the main results from assessment and mapping of the factors of sheet water erosion and the potential erosion risk on the territory of National Park "Central Balkan". For this purpose, the Universal Soil Loss Equation (USLE) was used for predicting soil loss from erosion. The influence of topography (LS-factor) and soil erodibility (K-factor) was assessed using small-scale topographic and soil maps. Rainfall erosivity (R-factor) was calculated from data of rainfalls with amounts exceeding 9.5 mm from 14 hydro-meteorological stations. The values of the erosion factors (R, K and LS) were presented for the areas of forest, sub-alpine and alpine zones. Using the methods of GIS, maps were plotted presenting the area distribution among the classes of the soil erosion factors and the potential risk in the respective zones. The results can be used for making accurate decisions for soil conservation and sustainable land management in the park.

  8. Development of an Integrated Water and Wind Erosion Model

    Science.gov (United States)

    Flanagan, D. C.; Ascough, J. C.; Wagner, L. E.; Geter, W. F.

    2006-12-01

    Prediction technologies for soil erosion by the forces of wind or water have largely been developed independently from one another, especially within the United States. Much of this has been due to the initial creation of equations and models which were empirical in nature (i.e., Universal Soil Loss Equation, Wind Erosion Equation) and based upon separate water erosion or wind erosion plot and field measurements. Additionally, institutional organizations in place typically divided research efforts and funding to unique wind or water erosion research and modeling projects. However, during the past 20 years computer technologies and erosion modeling have progressed to the point where it is now possible to merge physical process-based computer simulation models into an integrated water and wind erosion prediction system. In a physically- based model, many of the processes which must be simulated for wind and water erosion computations are the same, e.g., climate, water balance, runoff, plant growth, etc. Model components which specifically deal with the wind or water detachment, transport and deposition processes are those that must differ, as well as any necessary parameterization of input variables (e.g., adjusted soil erodibilities, critical shear stresses, etc.) for those components. This presentation describes current efforts towards development of a combined wind and water erosion model, based in part upon technologies present in the Water Erosion Prediction Project (WEPP) and the Wind Erosion Prediction System (WEPS) models. Initial efforts during the past two years have resulted in modular modeling components that allow for prediction of infiltration, surface runoff, and water erosion at a hillslope scale within an Object Modeling System. Additional components currently in development include wind detachment at a single field point, continuous water balance, and unified plant growth. Challenges in this project are many, and include adequate field

  9. Erosion-Oxidation Response of Boiler Grade Steels: A Mathematical Investigation

    Directory of Open Access Journals (Sweden)

    S. K. Das

    2008-01-01

    Full Text Available A ductile erosion model embodying the mechanisms of erosion involving cutting wear and repeated plastic deformation has been developed to predict erosion rates of boiler grade steels. The issue of erosion-oxidation interaction has also been addressed to further predict the mass loss resulted from this composite mechanism. A deterministic formalism for the kinetics of oxide-scale growth and a probabilistic approach to characterize the material loss are employed to describe simultaneous actions of high-temperature oxidation and mechanical erosion. The model predictions are in good agreement with the published data.

  10. IGF-1 Receptor Expression on Circulating Osteoblast Progenitor Cells Predicts Tissue-Based Bone Formation Rate and Response to Teriparatide in Premenopausal Women With Idiopathic Osteoporosis.

    Science.gov (United States)

    Cohen, Adi; Kousteni, Stavroula; Bisikirska, Brygida; Shah, Jayesh G; Manavalan, J Sanil; Recker, Robert R; Lappe, Joan; Dempster, David W; Zhou, Hua; McMahon, Donald J; Bucovsky, Mariana; Kamanda-Kosseh, Mafo; Stubby, Julie; Shane, Elizabeth

    2017-06-01

    We have previously reported that premenopausal women with idiopathic osteoporosis (IOP) have profound microarchitectural deficiencies and heterogeneous bone remodeling. Those with the lowest bone formation rate have higher baseline serum insulin-like growth factor-1 (IGF-1) levels and less robust response to teriparatide. Because IGF-1 stimulates bone formation and is critical for teriparatide action on osteoblasts, these findings suggest a state of IGF-1 resistance in some IOP women. To further investigate the hypothesis that osteoblast and IGF-1-related mechanisms mediate differential responsiveness to teriparatide in IOP, we studied circulating osteoblast progenitor (COP) cells and their IGF-1 receptor (IGF-1R) expression. In premenopausal women with IOP, peripheral blood mononuclear cells (PBMCs) were obtained at baseline (n = 25) and over 24 months of teriparatide treatment (n = 11). Flow cytometry was used to identify and quantify COPs (non-hematopoetic lineage cells expressing osteocalcin and RUNX2) and to quantify IGF-1R expression levels. At baseline, both the percent of PBMCs that were COPs (%COP) and COP cell-surface IGF-1R expression correlated directly with several histomorphometric indices of bone formation in tetracycline-labeled transiliac biopsies. In treated subjects, both %COP and IGF-1R expression increased promptly after teriparatide, returning toward baseline by 18 months. Although neither baseline %COP nor increase in %COP after 3 months predicted the bone mineral density (BMD) response to teriparatide, the percent increase in IGF-1R expression on COPs at 3 months correlated directly with the BMD response to teriparatide. Additionally, lower IGF-1R expression after teriparatide was associated with higher body fat, suggesting links between teriparatide resistance, body composition, and the GH/IGF-1 axis. In conclusion, these assays may be useful to characterize bone remodeling noninvasively and may serve to predict early response to

  11. Predicting factors associated with frailty in aged patients with bone-arthrosis pain in the clinic.

    Science.gov (United States)

    Li, Bao-Lin; Li, Wei; Bi, Jia-Qi; Meng, Qing-Gang; Fei, Jian-Feng

    2016-11-01

    To identify frail and pre-frail patients in a group of patients older than 60 years. The phenotype model of Fried's method was used to identify frailty and pre-frailty in total of 78 participants. Cognitive ability and psychosocial function tests were also given to 59 of the 78 patients. Prevalence of frailty and pre-frailty was 14.1% (11/78) and 46.2% (36/78), respectively. Of the 5 phenotype variables, weak grip strength was the most commonly seen variable with 53.8% of all participants and 100% in the frail group. Low energy expenditure, however, was not self-reported by any participant in the current study (0%). Prevalence of frailty in the present study is associated with chronological age. The current study indicates that 4 phenotypic variables (unintentional weight loss, self-reported exhaustion, gait speed and grip strength) contribute to the development to frailty, and that cognitive impairment and psychosocial frailty also predict frailty or pre-frailty in the patients older than 60 years old irrespective of chronic pain or osteoarthritis. The findings of the current study suggest frailty and pre-frailty are common in senior Chinese patients with chronic diseases. Recognition and identification of frailty in a rehabilitation clinic or hospital might help physicians to provide appropriate counseling to patients and families about adverse outcomes of certain treatments such as surgery, and could optimize management of coexisting chronic diseases that might contribute to or be affected by frailty.

  12. Mechanical characterization of structurally porous biomaterials built via additive manufacturing: experiments, predictive models, and design maps for load-bearing bone replacement implants.

    Science.gov (United States)

    Melancon, D; Bagheri, Z S; Johnston, R B; Liu, L; Tanzer, M; Pasini, D

    2017-11-01

    Porous biomaterials can be additively manufactured with micro-architecture tailored to satisfy the stringent mechano-biological requirements imposed by bone replacement implants. In a previous investigation, we introduced structurally porous biomaterials, featuring strength five times stronger than commercially available porous materials, and confirmed their bone ingrowth capability in an in vivo canine model. While encouraging, the manufactured biomaterials showed geometric mismatches between their internal porous architecture and that of its as-designed counterpart, as well as discrepancies between predicted and tested mechanical properties, issues not fully elucidated. In this work, we propose a systematic approach integrating computed tomography, mechanical testing, and statistical analysis of geometric imperfections to generate statistical based numerical models of high-strength additively manufactured porous biomaterials. The method is used to develop morphology and mechanical maps that illustrate the role played by pore size, porosity, strut thickness, and topology on the relations governing their elastic modulus and compressive yield strength. Overall, there are mismatches between the mechanical properties of ideal-geometry models and as-manufactured porous biomaterials with average errors of 49% and 41% respectively for compressive elastic modulus and yield strength. The proposed methodology gives more accurate predictions for the compressive stiffness and the compressive strength properties with a reduction of the average error to 11% and 7.6%. The implications of the results and the methodology here introduced are discussed in the relevant biomechanical and clinical context, with insight that highlights promises and limitations of additively manufactured porous biomaterials for load-bearing bone replacement implants. In this work, we perform mechanical characterization of load-bearing porous biomaterials for bone replacement over their entire design

  13. Coastal Erosion Control Methods

    Science.gov (United States)

    Greene, V.

    2016-12-01

    Coastal erosion is bad because the ecosystem there will be washed away and the animals could drown or be displaced and have to adapt to a new ecosystem that they are not prepared for. I'm interested in this problem because if there aren't beaches when I grow up I won't be able to do the things I would really like to do. I would like to be a marine biologist. Secondly, I don't want to see beach houses washed away. I would like to see people live in harmony with their environment. So, to study ways in which to preserve beaches I will make and use models that test different erosion controls. Two different ideas for erosion control I tested are using seaweed or a rock berm. I think the rock berm will work better than the model of seaweed because the seaweed is under water and the waves can carry the sand over the seaweed, and the rock berm will work better because the rocks will help break the waves up before they reach the shore and the waves can not carry the sand over the rocks that are above the water. To investigate this I got a container to use to model the Gulf of Mexico coastline. I performed several test runs using sand and water in the container to mimic the beach and waves from the Gulf of Mexico hitting the shoreline. I did three trials for the control (no erosion control), seaweed and a rock berm. Rock berms are a border of a raised area of rock. The model for seaweed that I used was plastic shopping bags cut into strips and glued to the bottom of my container to mimic seaweed. My results were that the control had the most erosion which ranged from 2.75 - 3 inches over 3 trials. The seaweed was a little better than the control but was very variable and ranged from 1.5 - 3 inches over 3 trials. The rock berm worked the best out of all at controlling erosion with erosion ranging from 1.5 - 2 inches. My hypothesis was correct because the rock berm did best to control erosion compared to the control which had no erosion control and the model with seaweed.

  14. Erosivity, surface runoff, and soil erosion estimation using GIS-coupled runoff-erosion model in the Mamuaba catchment, Brazil.

    Science.gov (United States)

    Marques da Silva, Richarde; Guimarães Santos, Celso Augusto; Carneiro de Lima Silva, Valeriano; Pereira e Silva, Leonardo

    2013-11-01

    This study evaluates erosivity, surface runoff generation, and soil erosion rates for Mamuaba catchment, sub-catchment of Gramame River basin (Brazil) by using the ArcView Soil and Water Assessment Tool (AvSWAT) model. Calibration and validation of the model was performed on monthly basis, and it could simulate surface runoff and soil erosion to a good level of accuracy. Daily rainfall data between 1969 and 1989 from six rain gauges were used, and the monthly rainfall erosivity of each station was computed for all the studied years. In order to evaluate the calibration and validation of the model, monthly runoff data between January 1978 and April 1982 from one runoff gauge were used as well. The estimated soil loss rates were also realistic when compared to what can be observed in the field and to results from previous studies around of catchment. The long-term average soil loss was estimated at 9.4 t ha(-1) year(-1); most of the area of the catchment (60%) was predicted to suffer from a low- to moderate-erosion risk (soil erosion was estimated to exceed > 12 t ha(-1) year(-1). Expectedly, estimated soil loss was significantly correlated with measured rainfall and simulated surface runoff. Based on the estimated soil loss rates, the catchment was divided into four priority categories (low, moderate, high and very high) for conservation intervention. The study demonstrates that the AvSWAT model provides a useful tool for soil erosion assessment from catchments and facilitates the planning for a sustainable land management in northeastern Brazil.

  15. ALPHA-CTX is associated with subchondral bone turnover and predicts progression of joint space narrowing and osteophytes in osteoarthritis

    Science.gov (United States)

    Huebner, Janet L; Bay-Jensen, Anne C; Huffman, Kim M; He, Yi; Leeming, Diana J; McDaniel, Gary E; Karsdal, Morten A; Kraus, Virginia B

    2014-01-01

    Objective To evaluate joint tissue remodeling, with urinary collagen biomarkers, uALPHA CTX and uCTXII, and their association with osteoarthritis (OA) severity, progression, and localized knee bone turnover. Methods Participants (N=149) with symptomatic and radiographic knee OA underwent fixed flexion knee radiography at baseline and 3 years, and late-phase bone scintigraphy of both knees at baseline, scored semi-quantitatively for osteophyte (OST) and joint space narrowing (JSN) severity and uptake intensity with scores summed across knees. Urinary concentrations of ALPHA CTX and CTXII were determined by ELISA. Immunohistochemistry of human OA knees was performed to localize the joint tissue origin of the biomarker epitopes. Results uALPHA CTX correlated strongly with intensity of bone scintigraphic uptake, and JSN and OST progression (risk ratio=13.2 and 3, respectively). uCTXII was strongly associated with intensity of bone scintigraphic uptake, with JSN and OST severity, and OA progression based on OST. uALPHA CTX localized primarily to high bone turnover areas in subchondral bone; CTXII localized to the bone-cartilage interface, the tidemark, and damaged articular cartilage. Conclusion Baseline uALPHA CTX, localized to high turnover areas of subchondral bone, was associated with dynamic bone turnover of knees signified by scintigraphy, and progression of both OST and JSN. uCTXII correlated with JSN and OST severity, and progression of OST. To our knowledge, this represents the first report of serological markers reflecting subchondral bone turnover. These collagen markers may be useful for non-invasive detection and quantification of active subchondral bone turnover and joint remodeling in knee OA. PMID:24909851

  16. Radiologic comparison of erosive polyarthritis with prominent interphalangeal involvement

    International Nuclear Information System (INIS)

    Gold, R.H.; Bassett, L.W.; Theros, E.G.

    1982-01-01

    Psoriatic arthritis, Reiter's disease, and multicentric reticulohistiocytosis may manifest prominent interphalangeal joint and cutaneous involvement. All three disorders may also affect the sacroiliac joints and spine. Despite these similarities, there are basic radiologic differences enabling distinction between the three disorders. Erosive osteoarthritis must also be considered in the differential diagnosis of interphalangeal erosive arthritis. Psoriatic erosions are characteristically ill defined, often bilaterally asymmetrical, usually unaccompanied by significant osteoporosis, and frequently associated with florid proliferation of subperiosteal new bone. An unilateral polyarticular pattern, which often occurs in a single ray, is the most prevalent of several patterns of involvement. Reiter's disease exhibits many clinical and radiologic similarities to psoriatic arthritis, but in the former there tends to be selective involvement of the joints of the lower limbs and particularly the feet, with relative sparing of the hands and wrists, while in the latter the joints of the upper and lower limbs tend to be involved to an equal extent. Multicentric reticulohistiocytosis (MR). Lesions predominate in skin and synovium and result in sharply circumscribed, rapidly progressive, strikingly bilaterally symmetrical erosions spreading from joint margins to articular surfaces. Most or all of the diarthrodial joints may be affected, but interphalangeal joint predominance and early and severe atlanto-axial involvement are characteristic. Erosive osteoarthritis is characterized by interphalangeal subchondral erosions, accompanying periosteal new bone that is more subtle than that of psoriatic arthritis, and interphalangeal bony ankylosis that occurs with the same frequency as that of psoriatic arthritis. (orig.)

  17. Effect of mechanical properties on erosion resistance of ductile materials

    Science.gov (United States)

    Levin, Boris Feliksovih

    Solid particle erosion (SPE) resistance of ductile Fe, Ni, and Co-based alloys as well as commercially pure Ni and Cu was studied. A model for SPE behavior of ductile materials is presented. The model incorporates the mechanical properties of the materials at the deformation conditions associated with SPE process, as well as the evolution of these properties during the erosion induced deformation. An erosion parameter was formulated based on consideration of the energy loss during erosion, and incorporates the material's hardness and toughness at high strain rates. The erosion model predicts that materials combining high hardness and toughness can exhibit good erosion resistance. To measure mechanical properties of materials, high strain rate compression tests using Hopkinson bar technique were conducted at strain rates similar to those during erosion. From these tests, failure strength and strain during erosion were estimated and used to calculate toughness of the materials. The proposed erosion parameter shows good correlation with experimentally measured erosion rates for all tested materials. To analyze subsurface deformation during erosion, microhardness and nanoindentation tests were performed on the cross-sections of the eroded materials and the size of the plastically deformed zone and the increase in materials hardness due to erosion were determined. A nanoindentation method was developed to estimate the restitution coefficient within plastically deformed regions of the eroded samples which provides a measure of the rebounding ability of a material during particle impact. An increase in hardness near the eroded surface led to an increase in restitution coefficient. Also, the stress rates imposed below the eroded surface were comparable to those measured during high strain-rate compression tests (10sp3-10sp4 ssp{-1}). A new parameter, "area under the microhardness curve" was developed that represents the ability of a material to absorb impact energy. By

  18. Rhizoma Dioscoreae extract protects against alveolar bone loss by regulating the cell cycle: A predictive study based on the protein‑protein interaction network.

    Science.gov (United States)

    Zhang, Zhi-Guo; Song, Chang-Heng; Zhang, Fang-Zhen; Chen, Yan-Jing; Xiang, Li-Hua; Xiao, Gary Guishan; Ju, Da-Hong

    2016-06-01

    Rhizoma Dioscoreae extract (RDE) exhibits a protective effect on alveolar bone loss in ovariectomized (OVX) rats. The aim of this study was to predict the pathways or targets that are regulated by RDE, by re‑assessing our previously reported data and conducting a protein‑protein interaction (PPI) network analysis. In total, 383 differentially expressed genes (≥3‑fold) between alveolar bone samples from the RDE and OVX group rats were identified, and a PPI network was constructed based on these genes. Furthermore, four molecular clusters (A‑D) in the PPI network with the smallest P‑values were detected by molecular complex detection (MCODE) algorithm. Using Database for Annotation, Visualization and Integrated Discovery (DAVID) and Ingenuity Pathway Analysis (IPA) tools, two molecular clusters (A and B) were enriched for biological process in Gene Ontology (GO). Only cluster A was associated with biological pathways in the IPA database. GO and pathway analysis results showed that cluster A, associated with cell cycle regulation, was the most important molecular cluster in the PPI network. In addition, cyclin‑dependent kinase 1 (CDK1) may be a key molecule achieving the cell‑cycle‑regulatory function of cluster A. From the PPI network analysis, it was predicted that delayed cell cycle progression in excessive alveolar bone remodeling via downregulation of CDK1 may be another mechanism underling the anti‑osteopenic effect of RDE on alveolar bone.

  19. Rainfall erosivity factor estimation in Republic of Moldova

    Science.gov (United States)

    Castraveš, Tudor; Kuhn, Nikolaus

    2017-04-01

    Rainfall erosivity represents a measure of the erosive force of rainfall. Typically, it is expressed as variable such as the R factor in the Universal Soil Loss Equation (USLE) (Wischmeier and Smith, 1965, 1978) or its derivates. The rainfall erosivity index for a rainfall event (EI30) is calculated from the total kinetic energy and maximum 30 minutes intensity of individual events. However, these data are often unavailable for wide regions and countries. Usually, there are three issues regarding precipitation data: low temporal resolution, low spatial density and limited access to the data. This is especially true for some of postsoviet countries from Eastern Europe, such as Republic of Moldova, where soil erosion is a real and persistent problem (Summer, 2003) and where soils represents the main natural resource of the country. Consequently, researching and managing soil erosion is particularly important. The purpose of this study is to develop a model based on commonly available rainfall data, such as event, daily or monthly amounts, to calculate rainfall erosivity for the territory of Republic of Moldova. Rainfall data collected during 1994-2015 period at 15 meteorological stations in the Republic of Moldova, with 10 minutes temporal resolution, were used to develop and calibrate a model to generate an erosivity map of Moldova. References 1. Summer, W., (2003). Soil erosion in the Republic of Moldova — the importance of institutional arrangements. Erosion Prediction in Ungauged Basins: Integrating Methods and Techniques (Proceedings of symposium HS01 held during IUGG2003 at Sapporo. July 2003). IAHS Publ. no. 279. 2. Wischmeier, W.H., and Smith, D.D. (1965). Predicting rainfall-erosion losses from cropland east of the Rocky Mountains. Agr. Handbook No. 282, U.S. Dept. Agr., Washington, DC 3. Wischmeier, W.H., and Smith, D.D. (1978). Predicting rainfall erosion losses. Agr. handbook No. 537, U.S. Dept. of Agr., Science and Education Administration.

  20. Prediction of femoral neck and spine bone mineral content from the BMC of the radius or ulna and the relationship between bone strength and BMC

    Science.gov (United States)

    Wilson, C. R.

    1974-01-01

    The bone mineral content (BMC) is extensively used to provide information about the status of an entire skeleton. Changes in BMC are employed to evaluate the effect of various drugs, disease states, weightlessness, exercise, renal dialysis and others on the skeleton. Clinical and functional information is discussed that may be derived from the BMC of a limited region of the skeleton. In particular there is a fairly high degree of correlation between the BMC of the radius or ulna and that of the femoral neck, r about 0.85 and a somewhat lower relationship between the BMC of the radius or ulna and the thoracic vertebrae, r about 0.65. Also the BMC is highly related to the strength of bone at that scan site.

  1. Erosive Lichen Planus.

    Science.gov (United States)

    Mauskar, Melissa

    2017-09-01

    Lichen planus is an inflammatory mucocutaneous condition with a myriad of clinical manifestations. There are 3 forms of lichen planus that effect the vulva: papulosquamous, hypertrophic, and erosive. Erosive lichen planus can progress to vulvar scaring, vaginal stenosis, and squamous cell carcinoma; these long-term sequelae cause sexual distress, depression, and decreased quality of life for patients. Diagnosis is often delayed because of patient embarrassment or clinician misdiagnosis. Early recognition and treatment is essential to decreasing the morbidity of this condition. Multimodal treatment, along with a multidisciplinary approach, will improve outcomes and further clinical advances in studying this condition. Copyright © 2017 Elsevier Inc. All rights reserved.

  2. Ten-year prediction of osteoporosis from baseline bone mineral density: development of prognostic thresholds in healthy postmenopausal women. The Danish Osteoporosis Prevention Study

    DEFF Research Database (Denmark)

    Abrahamsen, Bo; Rejnmark, Lars; Nielsen, Stig Pors

    2006-01-01

    Osteopenia is common in healthy women examined in the first year or two following menopause. Short-term fracture risk is low, but we lack algorithms to assess long-term risk of osteoporosis. Because bone loss proceeds at only a few percent per year, we speculated that baseline bone mineral density....... We analyzed dual energy X-ray absorptometry (DXA) of the lumbar spine (LS) and femoral neck (FN) from 872 women, who participated in the non-HRT arms of the Danish Osteoporosis Prevention Study and had remained on no HRT, bisphosphonates or raloxifene since inclusion 10 years ago. We defined...... development of a T -score below -2.5 at the LS and/or FN or incident fracture as end-point, and we derived prognostic thresholds for baseline BMD, defining 90% NPV (negative predictive value) and 90% sensitivity, respectively. Seventy-six percent of the variation in BMD of the LS at 10 years was predicted...

  3. Ten-year prediction of osteoporosis from baseline bone mineral density: development of prognostic thresholds in healthy postmenopausal women. The Danish Osteoporosis Prevention Study

    DEFF Research Database (Denmark)

    Abrahamsen, Bo; Rejnmark, Lars; Nielsen, Stig Pors

    2006-01-01

    Osteopenia is common in healthy women examined in the first year or two following menopause. Short-term fracture risk is low, but we lack algorithms to assess long-term risk of osteoporosis. Because bone loss proceeds at only a few percent per year, we speculated that baseline bone mineral density....... We analyzed dual energy X-ray absorptometry (DXA) of the lumbar spine (LS) and femoral neck (FN) from 872 women, who participated in the non-HRT arms of the Danish Osteoporosis Prevention Study and had remained on no HRT, bisphosphonates or raloxifene since inclusion 10 years ago. We defined...... development of a T -score below -2.5 at the LS and/or FN or incident fracture as end-point, and we derived prognostic thresholds for baseline BMD, defining 90% NPV (negative predictive value) and 90% sensitivity, respectively. Seventy-six percent of the variation in BMD of the LS at 10 years was predicted...

  4. Mesh erosion after abdominal sacrocolpopexy.

    Science.gov (United States)

    Kohli, N; Walsh, P M; Roat, T W; Karram, M M

    1998-12-01

    To report our experience with erosion of permanent suture or mesh material after abdominal sacrocolpopexy. A retrospective chart review was performed to identify patients who underwent sacrocolpopexy by the same surgeon over 8 years. Demographic data, operative notes, hospital records, and office charts were reviewed after sacrocolpopexy. Patients with erosion of either suture or mesh were treated initially with conservative therapy followed by surgical intervention as required. Fifty-seven patients underwent sacrocolpopexy using synthetic mesh during the study period. The mean (range) postoperative follow-up was 19.9 (1.3-50) months. Seven patients (12%) had erosions after abdominal sacrocolpopexy with two suture erosions and five mesh erosions. Patients with suture erosion were asymptomatic compared with patients with mesh erosion, who presented with vaginal bleeding or discharge. The mean (+/-standard deviation) time to erosion was 14.0+/-7.7 (range 4-24) months. Both patients with suture erosion were treated conservatively with estrogen cream. All five patients with mesh erosion required transvaginal removal of the mesh. Mesh erosion can follow abdominal sacrocolpopexy over a long time, and usually presents as vaginal bleeding or discharge. Although patients with suture erosion can be managed successfully with conservative treatment, patients with mesh erosion require surgical intervention. Transvaginal removal of the mesh with vaginal advancement appears to be an effective treatment in patients failing conservative management.

  5. The relationship between 3D bone architectural parameters and elastic moduli of three orthogonal directions predicted from finite elements analysis

    International Nuclear Information System (INIS)

    Park, Kwan Soo; Lee, Sam Sun; Huh, Kyung Hoe; Yi, Wan Jin; Heo, Min Suk; Choi, Soon Chul

    2008-01-01

    To investigate the relationship between 3D bone architectural parameters and direction-related elastic moduli of cancellous bone of mandibular condyle. Two micro-pigs (Micro-pigR, PWG Genetics Korea) were used. Each pig was about 12 months old and weighing around 44 kg. 31 cylindrical bone specimen were obtained from cancellous bone of condyles for 3D analysis and measured by micro-computed tomography. Six parameters were trabecular thickness (Tb.Th), bone specific surface (BS/BV), percent bone volume (BV/TV), structure model index (SMI), degree of anisotropy (DA) and 3-dimensional fractal dimension (3DFD). Elastic moduli of three orthogonal directions (superiorinferior (SI), medial-lateral (ML), andterior-posterior (AP) direction) were calculated through finite element analysis. Elastic modulus of superior-inferior direction was higher than those of other directions. Elastic moduli of 3 orthogonal directions showed different correlation with 3D architectural parameters. Elastic moduli of SI and ML directions showed significant strong to moderate correlation with BV/TV, SMI and 3DFD. Elastic modulus of cancellous bone of pig mandibular condyle was highest in the SI direction and it was supposed that the change into plate-like structure of trabeculae was mainly affected by increase of trabeculae of SI and ML directions.

  6. Paraphyseal changes on bone-age studies predict risk of delayed radiation-associated skeletal complications following total body irradiation

    International Nuclear Information System (INIS)

    Kitazono Hammell, Mary T.; Edgar, J.C.; Jaramillo, Diego; Bunin, Nancy

    2013-01-01

    Children undergoing total body irradiation (TBI) often develop delayed skeletal complications. Bone-age studies in these children often reveal subtle paraphyseal changes including physeal widening, metaphyseal irregularity and paraphyseal exostoses. To investigate whether paraphyseal changes on a bone-age study following TBI indicate a predisposition toward developing other radiation-associated skeletal complications. We retrospectively reviewed medical records and bone-age studies of 77 children receiving TBI at our institution between 1995 and 2008 who had at least 2 years of clinical follow-up and one bone-age study after TBI. We graded bone-age studies according to the severity of paraphyseal changes. All documented skeletal complications following TBI were tabulated. Kendall's tau-b was used to examine associations between degree of paraphyseal change and development of a skeletal complication. Kendall's tau analyses showed that physeal widening and metaphyseal irregularity/sclerosis (tau = 0.87, P < 0.001) and paraphyseal exostoses (tau = 0.68, P < 0.001) seen on bone-age studies were significantly positively associated with the development of delayed skeletal complications following TBI. Thirty percent of children with no or mild paraphyseal changes developed a delayed skeletal complication, compared with 58% of children with moderate paraphyseal changes and 90% of children with severe paraphyseal changes. Paraphyseal changes identified on a bone-age study correlate positively with the development of delayed skeletal complications elsewhere in the skeleton following TBI. (orig.)

  7. Oligometastatic state predicts a favorable outcome for renal cell carcinoma patients with bone metastasis under the treatment of sunitinib.

    Science.gov (United States)

    Lu, Xiaolin; Gu, Weijie; Zhang, Hailiang; Zhu, Yao; Shi, Guohai; Ye, Dingwei

    2016-05-03

    The aim of the study was to investigate whether RCC patients with oligometastatic state of bone metastasis treated with sunitinib had a favorable clinical outcome. 22 patients were classified into oligometastatic state of bone metastasis with a median OS of 30.1 months (95%CI: 26.3 to 33.8 months). The 45 patients with non-oligometastatic state had a median OS of 12.7 months (95%CI: 9.43 to 16.0 months). Kaplan-Meier analysis showed significant difference between them (Log Rank test p<0.001). When we set patients with only multiple bone (at least 5 sites) metastases as a single group, there was still significant difference between oligometastatic state group and non-oligometastatic state groups. In multivariate Cox proportion hazard ratio analysis, metastatic states (p=0.012), MSKCC score (p=0.002), ECOG (p=0.001) and lymph nodes metastasis (p=0.000) were significantly associated with prognosis. The integration of metastatic state into the MSKCC risk model improved the c-index from 0.651 to 0.752. 67 patients from Fudan University Shanghai Cancer Center with bone metastatic RCC were divided into 2 metastatic states. One included those with oligometastatic state of bone metastasis with less than 5 sites of bone metastasis. The other involved those patients with multiple bone metastases (at least 5 sites) or together with other sites of metastasis. Then patients with only multiple bone (at least 5 sites) metastases were set into a single group. RCC patients with oligometastatic state of bone metastasis treated with sunitinib had a favorable clinical outcome.

  8. Estimated erosion rate at the SRP burial ground

    International Nuclear Information System (INIS)

    Horton, J.H.; Wilhite, E.L.

    1978-04-01

    The rate of soil erosion at the Savannah River Plant (SRP) burial ground can be calculated by means of the universal soil loss equation. Erosion rates estimated by the equation are more suitable for long-term prediction than those which could be measured with a reasonable effort in field studies. The predicted erosion rate at the SRP burial ground ranges from 0.0007 cm/year under stable forest cover to 0.38 cm/year if farmed with cultivated crops. These values correspond to 170,000 and 320 years, respectively, to expose waste buried 4 ft deep

  9. Predictive implications of bone turnover markers after palliative treatment with 186Re-HEDP in hormone-refractory prostate cancer patients with painful osseous metastases

    International Nuclear Information System (INIS)

    Zafeirakis, Athanasios; Papatheodorou, Georgios; Arhontakis, Athanasios; Gouliamos, Athanasios; Vlahos, Lambros; Limouris, Georgios S.

    2010-01-01

    To prospectively evaluate the predictive value of various bone formation and resorption markers in patients with bone metastases from prostate cancer after palliative treatment with 186 Re-1,1-hydroxyethylidene diphosphonate ( 186 Re-HEDP). Included in the study were 36 men with prostate cancer, suffering from painful osseous metastases and treated with 186 Re-HEDP. None had received any treatment that would have interfered with bone metabolism before 186 Re-HEDP treatment or throughout the follow-up period. For each patient, pretreatment and posttreatment serum levels of osteocalcin (OC), bone alkaline phosphatase (BALP), aminoterminal (PINP) and carboxyterminal (PICP) propeptides of type I collagen, amino-terminal (NTx) and carboxyterminal (CTx) telopeptides of type I collagen and their combinations were compared with the level and duration of pain response to radionuclide treatment. Pain response was correlated only with pretreatment ΝΤx/PINP, PICP/PINP and NTx/CTx ratios and posttreatment decrease in baseline NTx and PICP values (p=0.0025-0.035). According to multivariate and ROC analyses, the best marker-derived predictors of better and longer duration of response to 186 Re-HEDP treatment were a posttreatment decrease in NTx of ≥20% (RR=3.44, p=0.0005) and a pretreatment NTx/PINP ratio of ≥1.2 (RR=3.04, p=0.036) NTx, a potent collagenous marker of bone resorption, along with the novel NTx/PINP ratio provide useful cut-off values for identifying a group of patients suffering from painful osseous metastases from hormone-refractory prostatic carcinoma who do not respond to palliative treatment with 186 Re-HEDP. This information could help avoid an inefficient and expensive radionuclide treatment. Also, in the cohort of patients who will eventually undergo such treatment, the medium-term posttreatment changes in NTx offer valuable predictive information regarding long-term palliative response. (orig.)

  10. Predictive implications of bone turnover markers after palliative treatment with {sup 186}Re-HEDP in hormone-refractory prostate cancer patients with painful osseous metastases

    Energy Technology Data Exchange (ETDEWEB)

    Zafeirakis, Athanasios [401 Army Hospital of Athens, Department of Nuclear Medicine, Athens (Greece); Papatheodorou, Georgios [401 Army Hospital of Athens, Clinical Research Unit, Athens (Greece); Arhontakis, Athanasios [401 Army Hospital of Athens, Department of Urology, Athens (Greece); Gouliamos, Athanasios; Vlahos, Lambros [Aretaieion University Hospital, Athens Medical School, Department of Radiology, Athens (Greece); Limouris, Georgios S. [Aretaieion University Hospital, Athens Medical School, Department of Nuclear Medicine, Athens (Greece)

    2010-01-15

    To prospectively evaluate the predictive value of various bone formation and resorption markers in patients with bone metastases from prostate cancer after palliative treatment with {sup 186}Re-1,1-hydroxyethylidene diphosphonate ({sup 186}Re-HEDP). Included in the study were 36 men with prostate cancer, suffering from painful osseous metastases and treated with {sup 186}Re-HEDP. None had received any treatment that would have interfered with bone metabolism before {sup 186}Re-HEDP treatment or throughout the follow-up period. For each patient, pretreatment and posttreatment serum levels of osteocalcin (OC), bone alkaline phosphatase (BALP), aminoterminal (PINP) and carboxyterminal (PICP) propeptides of type I collagen, amino-terminal (NTx) and carboxyterminal (CTx) telopeptides of type I collagen and their combinations were compared with the level and duration of pain response to radionuclide treatment. Pain response was correlated only with pretreatment {nu}{tau}x/PINP, PICP/PINP and NTx/CTx ratios and posttreatment decrease in baseline NTx and PICP values (p=0.0025-0.035). According to multivariate and ROC analyses, the best marker-derived predictors of better and longer duration of response to {sup 186}Re-HEDP treatment were a posttreatment decrease in NTx of {>=}20% (RR=3.44, p=0.0005) and a pretreatment NTx/PINP ratio of {>=}1.2 (RR=3.04, p=0.036) NTx, a potent collagenous marker of bone resorption, along with the novel NTx/PINP ratio provide useful cut-off values for identifying a group of patients suffering from painful osseous metastases from hormone-refractory prostatic carcinoma who do not respond to palliative treatment with {sup 186}Re-HEDP. This information could help avoid an inefficient and expensive radionuclide treatment. Also, in the cohort of patients who will eventually undergo such treatment, the medium-term posttreatment changes in NTx offer valuable predictive information regarding long-term palliative response. (orig.)

  11. Erosion of dust aggregates

    NARCIS (Netherlands)

    Seizinger, A.; Krijt, S.; Kley, W.

    2013-01-01

    Aims: The aim of this work is to gain a deeper insight into how much different aggregate types are affected by erosion. Especially, it is important to study the influence of the velocity of the impacting projectiles. We also want to provide models for dust growth in protoplanetary disks with simple

  12. Hydrology and soil erosion

    Science.gov (United States)

    Leonard J. Lane; Mary R. Kidwell

    2003-01-01

    We review research on surface water hydrology and soil erosion at the Santa Rita Experimental Range (SRER). Almost all of the research was associated with eight small experimental watersheds established from 1974 to 1975 and operated until the present. Analysis of climatic features of the SRER supports extending research findings from the SRER to broad areas of the...

  13. Bentonite erosion. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Birgersson, Martin; Boergesson, Lennart; Hedstroem, Magnus; Karnland, Ola; Nilsson, Ulf (Clay Technology AB, Lund (Sweden))

    2009-12-15

    Low saline water may reach KBS-3 repository depth, e.g. during periods of glaciation. Under such aqueous conditions, the montmorillonite part of the bentonite buffer might transform into a sol and thereby be transported away with flowing water in fractures. The primary aim with this report is to improve the understanding of the basic principles for this possible montmorillonite particle release. The report includes experimental and theoretical work performed at Clay Technology. Natural bentonite and ion-exchanged purified montmorillonite from three different geographical origins, Wyoming (U.S.), Milos (Greece) and Kutch (India) have been studied. Experimental and/or theoretical investigations have been performed with respect to: - Free swelling ability; - Rheological properties; - Rate of bentonite loss into fractures; - Filtering; - Ion exchange; - Sol formation ability; - Ion diffusion; - Mass loss due to erosion. The performed erosion experiments show that erosion does not occur in a mixed calcium/sodium montmorillonite with at least 20% calcium in exchange positions, when the external solution contains above 4 mM charge equivalents. This result is in agreement with the presented conceptual view of sol formation and measured equilibrium properties in mixed calcium/sodium montmorillonite. The findings imply that the buffer will be stable for non-glacial conditions. However, erosion due to sol formation cannot be ruled out for glacial conditions.

  14. Erosion scenarios for Wellenberg

    International Nuclear Information System (INIS)

    Klemenz, W.

    1993-09-01

    The proposed Wellenberg site for a radioactive waste repository is located between Altzellen in the Engelberger valley and the Oberrickenbach valley, in a thick Valanginian marl series. The marl is generally overlaid with unconsolidated rocks but reaches to the surface in some places. In contrast to the situation in the Oberbauenstock region this marl complex is not protected by an overlying erosion resistant series and exhibits a marked relief. The question therefore arises with respect to the Wellenberg site, to what extent will the marl (i.e. the repository host rock formation) be removed by erosion processes during the 100,000 years interval under consideration and what overburden will remain at the end of this period. This report presents the results of an investigation of the longterm behaviour of the proposed site in respect of those processes of erosion and deposition which can lead to changes in the terrain surface and its location relative to the repository. A wide range of possible scenarios encompassing different developments of climatic conditions during the 100,000 year period of interest, was investigated. In addition to the continuation of the present climate and the occurrence of a new ice age on the scale of the Wuerm glaciation the consequences of altered climatic conditions on erosion removal of the repository overburden were considered. Within the 100,000 year period of interest none of the scenarios considered leads to the exposure of the repository. (author) figs., tabs, refs

  15. Dune erosion above revetments

    NARCIS (Netherlands)

    Van Thiel de Vries, J.S.M.

    2012-01-01

    In a situation with a narrow dune, the dune base can be protected with a revetment to reduce dune erosion during extreme events. To quantify the effects of a revetment on storm impact, the functionality of the numerical storm impact model XBeach (Roelvink et al., 2009) is extended to account for the

  16. Bentonite erosion. Final report

    International Nuclear Information System (INIS)

    Birgersson, Martin; Boergesson, Lennart; Hedstroem, Magnus; Karnland, Ola; Nilsson, Ulf

    2009-12-01

    Low saline water may reach KBS-3 repository depth, e.g. during periods of glaciation. Under such aqueous conditions, the montmorillonite part of the bentonite buffer might transform into a sol and thereby be transported away with flowing water in fractures. The primary aim with this report is to improve the understanding of the basic principles for this possible montmorillonite particle release. The report includes experimental and theoretical work performed at Clay Technology. Natural bentonite and ion-exchanged purified montmorillonite from three different geographical origins, Wyoming (U.S.), Milos (Greece) and Kutch (India) have been studied. Experimental and/or theoretical investigations have been performed with respect to: - Free swelling ability; - Rheological properties; - Rate of bentonite loss into fractures; - Filtering; - Ion exchange; - Sol formation ability; - Ion diffusion; - Mass loss due to erosion. The performed erosion experiments show that erosion does not occur in a mixed calcium/sodium montmorillonite with at least 20% calcium in exchange positions, when the external solution contains above 4 mM charge equivalents. This result is in agreement with the presented conceptual view of sol formation and measured equilibrium properties in mixed calcium/sodium montmorillonite. The findings imply that the buffer will be stable for non-glacial conditions. However, erosion due to sol formation cannot be ruled out for glacial conditions.

  17. Can control of soil erosion mitigate water pollution by sediments?

    Science.gov (United States)

    Rickson, R J

    2014-01-15

    The detrimental impact of sediment and associated pollutants on water quality is widely acknowledged, with many watercourses in the UK failing to meet the standard of 'good ecological status'. Catchment sediment budgets show that hill slope erosion processes can be significant sources of waterborne sediment, with rates of erosion likely to increase given predicted future weather patterns. However, linking on-site erosion rates with off-site impacts is complicated because of the limited data on soil erosion rates in the UK and the dynamic nature of the source-pathway-receptor continuum over space and time. Even so, soil erosion control measures are designed to reduce sediment production (source) and mobilisation/transport (pathway) on hill slopes, with consequent mitigation of pollution incidents in watercourses (receptors). The purpose of this paper is to review the scientific evidence of the effectiveness of erosion control measures used in the UK to reduce sediment loads of hill slope origin in watercourses. Although over 73 soil erosion mitigation measures have been identified from the literature, empirical data on erosion control effectiveness are limited. Baseline comparisons for the 18 measures where data do exist reveal erosion control effectiveness is highly variable over time and between study locations. Given the limitations of the evidence base in terms of geographical coverage and duration of monitoring, performance of the different measures cannot be extrapolated to other areas. This uncertainty in effectiveness has implications for implementing erosion/sediment risk reduction policies, where quantified targets are stipulated, as is the case in the EU Freshwater Fish and draft Soil Framework Directives. Also, demonstrating technical effectiveness of erosion control measures alone will not encourage uptake by land managers: quantifying the costs and benefits of adopting erosion mitigation is equally important, but these are uncertain and difficult to

  18. Categorization of erosion control matting.

    Science.gov (United States)

    2012-05-29

    Erosion control is a critical aspect of any Georgia Department of Transportation (GDOT) : construction project, with the extreme negative impacts of high sediment loads in natural : waterways having been well documented. A variety of erosion control ...

  19. Prediction of bone mineral density and content from measures of physical activity and sedentary behavior in younger and older females

    Directory of Open Access Journals (Sweden)

    Saori I. Braun

    2015-01-01

    Conclusions: These findings highlight the importance of engaging in sufficient moderate-to-vigorous physical activity during adolescence and reducing sedentary behavior in older adults to improve bone health in females.

  20. Analysis of C-MOD molybdenum divertor erosion and code/data comparison

    Energy Technology Data Exchange (ETDEWEB)

    Brooks, J.N., E-mail: brooksjn@purdue.edu [Purdue University, West Lafayette, IN (United States); Allain, J.P. [Purdue University, West Lafayette, IN (United States); Whyte, D.G.; Ochoukov, R.; Lipschultz, B. [Massachusetts Institute of Technology, Cambridge, MA (United States)

    2011-08-01

    We analyze an important 15 year old Alcator C-MOD study of campaign-integrated molybdenum divertor erosion in which the measured net erosion was significantly higher ({approx}X3) than originally predicted by a simple model . We perform full process sputtering erosion/redeposition computational analysis including the effect of a possible RF induced sheath. The simulations show that most sputtered Mo atoms are ionized close to the surface and strongly redeposited, via Lorentz force motion and collisional friction with the high density incoming plasma. The predicted gross erosion profile is a reasonable match to MoI influx data, however, the critically important net erosion comparison with post-exposure Mo tile analysis is poor, with {approx}X10 higher peak erosion measured than computed. An RF sheath increases predicted erosion by {approx}45%, thus being significant but not fundamental. We plan future analysis.

  1. The role of fat in the prediction of bone strength of porcine lumbar vertebrae by quanititative computed tomography

    International Nuclear Information System (INIS)

    Chang, G.L.; Tsai, K.H.; Yu, C.Y.; Lin, R.M.

    1996-01-01

    In order to prevent cancellous bone fractures, and understanding of the strength characteristics of cancellous bone must be achieved. Although there is a definite relationship between the strengt and relative ash content of the vertebrae, the well-known relationship is not practical in clinical use. As we know, QCT was regarded as an ideal method because it is a cross-sectional tecnique. However, no matter what kind of CT machine was used, the physiological factor must be influencing the accuracy in QCT measurement. Because a given region of the vertebrae contains bone mineral, bone matrix, fatty marrow and red marrow. In words, the role of fat content in bony strength and QCT measurement remained obscure. If QCT can reflect the bone strength to a reliable level and the influence of fat on QCT can be clarified, then QCT may become more useful. Therefore, the purpose of this study was to investigate the relationships among fat content, bone strength and QCT. Six freshly female porcine lumbar spinal semgemts were used in this study. Poster 182. (author)

  2. Using remote sensing data to predict road fill areas and areas affected by fill erosion with planned forest road construction: a case study in Kastamonu Regional Forest Directorate (Turkey).

    Science.gov (United States)

    Aricak, Burak

    2015-07-01

    Forest roads are essential for transport in managed forests, yet road construction causes environmental disturbance, both in the surface area the road covers and in erosion and downslope deposition of road fill material. The factors affecting the deposition distance of eroded road fill are the slope gradient and the density of plant cover. Thus, it is important to take these factors into consideration during road planning to minimize their disturbance. The aim of this study was to use remote sensing and field surveying to predict the locations that would be affected by downslope deposition of eroding road fill and to compile the data into a geographic information system (GIS) database. The construction of 99,500 m of forest roads is proposed for the Kastamonu Regional Forest Directorate in Turkey. Using GeoEye satellite images and a digital elevation model (DEM) for the region, the location and extent of downslope deposition of road fill were determined for the roads as planned. It was found that if the proposed roads were constructed by excavators, the fill material would cover 910,621 m(2) and the affected surface area would be 1,302,740 m(2). Application of the method used here can minimize the adverse effects of forest roads.

  3. Erosion Modeling of the High Contraction Chromium Plated Crusader Gun System

    National Research Council Canada - National Science Library

    Sopok, S

    2003-01-01

    Thermal-chemical- mechanical erosion modeling predictions are given for the high contraction chromium plated Crusader gun system based on extensive cannon firing, inspection, characterization, and experimental data...

  4. Soil erosion in Iran: Issues and solutions

    Science.gov (United States)

    Hamidreza Sadeghi, Seyed; Cerdà, Artemi

    2015-04-01

    Iran currently faces many soil erosion-related problems (see citations below). These issues are resulted from some inherent characteristic and anthropogenic triggering forces. Nowadays, the latter plays more important rule to accelerate the erosion with further emphasis on soil erosion-prone arid and semi arid regions of the country. This contribution attempts to identify and describe the existing main reasons behind accelerated soil erosion in Iran. Appropriate solutions viz. structural and non-structural approaches will be then advised to combat or minimise the problems. Iran can be used as a pilot research site to understand the soil erosion processes in semiarid, arid and mountainous terrain and our research will review the scientific literature and will give an insight of the soil erosion rates in the main factors of the soil erosion in Iran. Key words: Anthropogenic Erosion, Land Degradation; Sediment Management; Sediment Problems Acknowledgements The research projects GL2008-02879/BTE, LEDDRA 243857 and PREVENTING AND REMEDIATING DEGRADATION OF SOILS IN EUROPE THROUGH LAND CARE (RECARE)FP7-ENV-2013- supported this research. References Aghili Nategh, N., Hemmat, A., & Sadeghi, M. (2014). Assessing confined and semi-confined compression curves of highly calcareous remolded soil amended with farmyard manure. Journal of Terramechanics, 53, 75-82. Arekhi, S., Bolourani, A. D., Shabani, A., Fathizad, H., Ahamdy-Asbchin, S. 2012. Mapping Soil Erosion and Sediment Yield Susceptibility using RUSLE, Remote Sensing and GIS (Case study: Cham Gardalan Watershed, Iran). Advances in Environmental Biology, 6(1), 109-124. Arekhi, S., Shabani, A., Rostamizad, G. 2012. Application of the modified universal soil loss equation (MUSLE) in prediction of sediment yield (Case study: Kengir Watershed, Iran). Arabian Journal of Geosciences, 5(6), 1259-1267.Sadeghi, S. H., Moosavi, V., Karami, A., Behnia, N. 2012. Soil erosion assessment and prioritization of affecting factors at plot

  5. Soil erodibility for water erosion: A perspective and Chinese experiences

    Science.gov (United States)

    Wang, Bin; Zheng, Fenli; Römkens, Mathias J. M.; Darboux, Frédéric

    2013-04-01

    Knowledge of soil erodibility is an essential requirement for erosion prediction, conservation planning, and the assessment of sediment related environmental effects of watershed agricultural practices. This paper reviews the status of soil erodibility evaluations and determinations based on 80 years of upland area erosion research mainly in China and the USA. The review synthesizes the general research progress made by discussing the basic concepts of erodibility and its evaluation, determination, and prediction as well as knowledge of its spatio-temporal variations. The authors found that soil erodibility is often inappropriately or inaccurately applied in describing soil loss caused by different soil erosion component processes and mechanisms. Soil erodibility indicators were related to intrinsic soil properties and exogenic erosional forces, measurements, and calculations. The present review describes major needs including: (1) improved definition of erodibility, (2) modified erodibility determinations in erosion models, especially for specific geographical locations and in the context of different erosion sub-processes, (3) advanced methodologies for quantifying erodibilities of different soil erosion sub-processes, and (4) a better understanding of the mechanism that causes temporal variations in soil erodibility. The review also provides a more rational basis for future research on soil erodibility and supports predictive modeling of soil erosion processes and the development of improved conservation practices.

  6. Bone tumors

    International Nuclear Information System (INIS)

    Unni, K.K.

    1988-01-01

    This book contains the proceedings on bone tumors. Topics covered include: Bone tumor imaging: Contribution of CT and MRI, staging of bone tumors, perind cell tumors of bone, and metastatic bone disease

  7. The 'pre-erosive' radiologic signs of rheumatoid arthritis in soft tissue radiography of the hands

    International Nuclear Information System (INIS)

    Maekelae, P.; Virtama, P.

    1978-01-01

    Soft tissue radiography of the hands using the mammographic immersion technique was performed on 119 patients, having definite or classical rheumatoid arthritis, and on 123 controls of matching age, sex, and professional distribution. A total of 7744 finger joints and carpal borders were investigated for joint swelling, periarticular edema, pre-erosive and erosive bone changes, joint space narrowing, and osteoarthritic joint margin spurs. Slight joint swelling and pre-erosive bone changes were found in connection with osteoarthritic joint changes in elderly control patients. Periarticular edema and moderate to massive joint swelling were quite reliable signs for synovitis. The incidence of pre-erosive bone signs was significantly greater in the rheumatoid arthritis group than in the control group, especially in patients less than 60 years old. These signs can be regarded as suggestive of rheumatoid arthritis; probability diagnosis could be performed using these signs and the Bayesian approach. (orig.) [de

  8. 'pre-erosive' radiologic signs of rheumatoid arthritis in soft tissue radiography of the hands

    Energy Technology Data Exchange (ETDEWEB)

    Maekelae, P; Virtama, P [Turku Univ. (Finland). Dept. of Diagnostic Radiology

    1978-01-01

    Soft tissue radiography of the hands using the mammographic immersion technique was performed on 119 patients, having definite or classical rheumatoid arthritis, and on 123 controls of matching age, sex, and professional distribution. A total of 7744 finger joints and carpal borders were investigated for joint swelling, periarticular edema, pre-erosive and erosive bone changes, joint space narrowing, and osteoarthritic joint margin spurs. Slight joint swelling and pre-erosive bone changes were found in connection with osteoarthritic joint changes in elderly control patients. Periarticular edema and moderate to massive joint swelling were quite reliable signs for synovitis. The incidence of pre-erosive bone signs was significantly greater in the rheumatoid arthritis group than in the control group, especially in patients less than 60 years old. These signs can be regarded as suggestive of rheumatoid arthritis; probability diagnosis could be performed using these signs and the Bayesian approach.

  9. Damage diagnostic of localized impact erosion by measuring acoustic vibration

    International Nuclear Information System (INIS)

    Futakawa, Masatoshi; Kogawa, Hiroyuki; Ikeda, Yujiro

    2004-01-01

    High power spallation targets for neutron sources are being developed in the world. Mercury target will be installed at the material and life science facility in J-PARC, which will promote innovative science. The mercury target is subject to the pressure wave caused by the proton bombarding mercury. The pressure wave propagation induces the cavitation in mercury that imposes localized impact erosion damage on the target vessel. The impact erosion is a critical issue to decide the lifetime of the target. The electric Magnetic IMpact Testing Machine, MIMTM, was developed to produce the localized impact erosion damage and evaluate the damage formation. Acoustic vibration measurement was carried out to investigate the correlation between the erosion damage and the damage potential derived from acoustic vibration. It was confirmed that the damage potential related with acoustic vibration is useful to predict the damage due to the localized impact erosion and to diagnose the structural integrity. (author)

  10. Chronic contained rupture of abdominal aortic aneurysm (CCR-AAA) with massive vertebral bone erosion: computed tomography (CT), magnetic resonance imaging (MRI) and fluorine-18-fluorodeoxyglucose positron emission tomography (FDG-PET) findings.

    Science.gov (United States)

    Nakano, Sachiko; Okauchi, Kenzo; Tsushima, Yoshito

    2014-02-01

    A 62-year-old male presented with sudden onset of low back and right leg pain. Contrast-enhanced computed tomography demonstrated an abdominal aortic aneurysm (AAA), along with a large mass lesion causing vertebral body erosion. Magnetic resonance imaging (MRI) suggested that the mass lesion consisted of a chronic hematoma. Fluorine-18-fluorodeoxyglucose positron emission tomography (FDG-PET) demonstrated increased uptake around the mass lesion, but not around the AAA. Surgical intervention was performed, and the subsequent histological diagnosis was chronic contained rupture of AAA. The mass lesion consisted of chronic hematoma and necrosis with inflammatory cell infiltration and hemosiderin deposition. This condition mimics some neoplastic diseases, but MRI and FDG-PET findings may help establish the correct diagnosis.

  11. Chronic contained rupture of abdominal aortic aneurysm (CCR-AAA) with massive vertebral bone erosion. Computed tomography (CT), magnetic resonance imaging (MRI) and fluorine-18-fluorodeoxyglucose positron emission tomography (FDG-PET) findings

    International Nuclear Information System (INIS)

    Nakano, Sachiko; Okauchi, Kenzo; Tsushima, Yoshito

    2014-01-01

    A 62-year-old male presented with sudden onset of low back and right leg pain. Contrast-enhanced computed tomography demonstrated an abdominal aortic aneurysm (AAA), along with a large mass lesion causing vertebral body erosion. Magnetic resonance imaging (MRI) suggested that the mass lesion consisted of a chronic hematoma. Fluorine-18-fluorodeoxyglucose positron emission tomography (FDG-PET) demonstrated increased uptake around the mass lesion, but not around the AAA. Surgical intervention was performed, and the subsequent histological diagnosis was chronic contained rupture of AAA. The mass lesion consisted of chronic hematoma and necrosis with inflammatory cell infiltration and hemosiderin deposition. This condition mimics some neoplastic diseases, but MRI and FDG-PET findings may help establish the correct diagnosis. (author)

  12. Rainfall erosivity map for Ghana

    International Nuclear Information System (INIS)

    Oduro Afriyie, K.

    1995-10-01

    Monthly rainfall data, spanning over a period of more than thirty years, were used to compute rainfall erosivity indices for various stations in Ghana, using the Fournier index, c, defined as p 2 /P, where p is the rainfall amount in the wettest month and P is the annual rainfall amount. Values of the rainfall erosivity indices ranged from 24.5 mm at Sunyani in the mid-portion of Ghana to 180.9 mm at Axim in the south western coastal portion. The indices were used to construct a rainfall erosivity map for the country. The map revealed that Ghana may be broadly divided into five major erosion risk zones. The middle sector of Ghana is generally in the low erosion risk zone; the northern sector is in the moderate to severe erosion risk zone, while the coastal sector is in the severe to extreme severe erosion risk zone. (author). 11 refs, 1 fig., 1 tab

  13. A Mechanistic Model of Waterfall Plunge Pool Erosion into Bedrock

    Science.gov (United States)

    Scheingross, Joel S.; Lamb, Michael P.

    2017-11-01

    Landscapes often respond to changes in climate and tectonics through the formation and upstream propagation of knickzones composed of waterfalls. Little work has been done on the mechanics of waterfall erosion, and instead most landscape-scale models neglect waterfalls or use rules for river erosion, such as stream power, that may not be applicable to waterfalls. Here we develop a physically based model to predict waterfall plunge pool erosion into rock by abrasion from particle impacts and test the model against flume experiments. Both the model and experiments show that evolving plunge pools have initially high vertical erosion rates due to energetic particle impacts, and erosion slows and eventually ceases as pools deepen and deposition protects the pool floor from further erosion. Lateral erosion can continue after deposition on the pool floor, but it occurs at slow rates that become negligible as pools widen. Our work points to the importance of vertical drilling of successive plunge pools to drive upstream knickzone propagation in homogenous rock, rather than the classic mechanism of headwall undercutting. For a series of vertically drilling waterfalls, we find that upstream knickzone propagation is faster under higher combined water and sediment fluxes and for knickzones composed of many waterfalls that are closely spaced. Our model differs significantly from stream-power-based erosion rules in that steeper knickzones can retreat faster or more slowly depending on the number and spacing of waterfalls within a knickzone, which has implications for interpreting climatic and tectonic history through analysis of river longitudinal profiles.

  14. Fluorine-18-fluorocholine PET/CT parameters predictive for hematological toxicity to radium-223 therapy in castrate-resistant prostate cancer patients with bone metastases: a pilot study.

    Science.gov (United States)

    Vija Racaru, Lavinia; Sinigaglia, Mathieu; Kanoun, Salim; Ben Bouallègue, Fayçal; Tal, Ilan; Brillouet, Sévérine; Bauriaud-Mallet, Mathilde; Zerdoud, Slimane; Dierickx, Lawrence; Vallot, Delphine; Caselles, Olivier; Gabiache, Erwan; Pascal, Pierre; Courbon, Frederic

    2018-05-21

    This study aims to predict hematological toxicity induced by Ra therapy. We investigated the value of metabolically active bone tumor volume (MBTV) and total bone lesion activity (TLA) calculated on pretreatment fluorine-18-fluorocholine (F-FCH) PET/CT in castrate-resistant prostate cancer (CRPC) patients with bone metastases treated with Ra radionuclide therapy. F-FCH PET/CT imaging was performed in 15 patients with CRPC before treatment with Ra. Bone metastatic disease was quantified on the basis of the maximum standardized uptake value (SUV), total lesion activity (TLA=MBTV×SUVmean), or MBTV/height (MBTV/H) and TLA/H. F-FCH PET/CT bone tumor burden and activity were analyzed to identify which parameters could predict hematological toxicity [on hemoglobin (Hb), platelets (PLTs), and lymphocytes] while on Ra therapy. Pearson's correlation was used to identify the correlations between age, prostate-specific antigen, and F-FCH PET parameters. MBTV ranged from 75 to 1259 cm (median: 392 cm). TLA ranged from 342 to 7198 cm (median: 1853 cm). Patients benefited from two to six cycles of Ra (n=56 cycles in total). At the end of Ra therapy, five of the 15 (33%) patients presented grade 2/3 toxicity on Hb and lymphocytes, whereas three of the 15 (20%) patients presented grade 2/3 PLT toxicity.Age was correlated negatively with both MBTV (r=-0.612, P=0.015) and TLA (r=-0.596, P=0.018). TLA, TLA/H, and MBTV/H predicted hematological toxicity on Hb, whereas TLA/H and MBTV/H predicted toxicity on PLTs at the end of Ra cycles. Receiver operating characteristic curve analysis allowed to define the cutoffs for MBTV (915 cm) and TLA (4198 cm) predictive for PLT toxicity, with an accuracy of 0.92 and 0.99. Tumor bone burden calculation is feasible with F-FCH PET/CT with freely available open-source software. In this pilot study, baseline F-FCH PET/CT markers (TLA, MBTV) have shown abilities to predict Hb and PLT toxicity after Ra therapy and could be explored for

  15. Erosion-corrosion synergistics in the low erosion regime

    International Nuclear Information System (INIS)

    Corey, R.G.; Sethi, V.K.

    1986-01-01

    Many engineering alloys display good high temperature corrosion resistance. However, when they are used in corrosive environments where they are subjected to erosion also, the corrosion resistance has been adversely affected. The phenomenon known as erosion-corrosion is complex and requires detailed investigation of how the erosion and corrosion kinetics interact and compete. At the Kentucky Center for Energy Research Laboratory, an erosion-corrosion tester was used to perform erosion-oxidation tests on 2 1/4 Cr-1 Mo steel at 500-600 0 C using alumina abrasive at low velocities. The erosion-oxidation rate data and morphology of exposed surfaces are consistent with oxide chipping and fracturing being the mode of material loss

  16. Bone age estimation and prediction of final height in patients with β-thalassaemia major: a comparison between the two most common methods

    International Nuclear Information System (INIS)

    Christoforidis, Athanasios; Katzos, George; Athanassiou-Metaxa, Miranda; Badouraki, Maria

    2007-01-01

    Thalassaemic patients are in need of frequent assessment of bone age because of growth failure and pubertal disorders. To compare the ''rapid'' Greulich and Pyle (G and P) method with the third edition of the Tanner and Whitehouse (TW3) method for determining skeletal maturity and predicting final height in thalassaemic patients. A total of 191 radiographs from 58 patients (28 male, 30 female) were retrospectively evaluated by two investigators, one for each method. In 47 radiographs from 15 patients having attained their adult height, predicted final height was calculated according to each method. The mean bone ages determined by both the G and P and TW3 methods were lower than mean chronological age, although the differences were not statistically significant (10.04 ± 3.69 years and 9.98 ± 3.39 years vs. 10.78 ± 3.96 years, respectively). Both methods had a tendency to over-estimate final height. Overall, the TW3 method seemed to be more accurate than the G and P method (mean absolute error 3.21 ± 2.51 years vs. 3.99 ± 2.99 years, respectively, P=0.048). The same method should be used when serial assessments are performed, as both methods provide similarly reliable, although not equivalent, results. The TW3 height prediction method seemed to be more accurate in patients with β-thalassaemia major than the G and P method, albeit with a large confidence interval. (orig.)

  17. Bone age estimation and prediction of final height in patients with {beta}-thalassaemia major: a comparison between the two most common methods

    Energy Technology Data Exchange (ETDEWEB)

    Christoforidis, Athanasios; Katzos, George; Athanassiou-Metaxa, Miranda [Aristotle University of Thessaloniki, 1st Paediatric Department, Thessaloniki (Greece); Badouraki, Maria [Ippokratio Hospital, Paediatric Radiology Department, Thessaloniki (Greece)

    2007-12-15

    Thalassaemic patients are in need of frequent assessment of bone age because of growth failure and pubertal disorders. To compare the ''rapid'' Greulich and Pyle (G and P) method with the third edition of the Tanner and Whitehouse (TW3) method for determining skeletal maturity and predicting final height in thalassaemic patients. A total of 191 radiographs from 58 patients (28 male, 30 female) were retrospectively evaluated by two investigators, one for each method. In 47 radiographs from 15 patients having attained their adult height, predicted final height was calculated according to each method. The mean bone ages determined by both the G and P and TW3 methods were lower than mean chronological age, although the differences were not statistically significant (10.04 {+-} 3.69 years and 9.98 {+-} 3.39 years vs. 10.78 {+-} 3.96 years, respectively). Both methods had a tendency to over-estimate final height. Overall, the TW3 method seemed to be more accurate than the G and P method (mean absolute error 3.21 {+-} 2.51 years vs. 3.99 {+-} 2.99 years, respectively, P=0.048). The same method should be used when serial assessments are performed, as both methods provide similarly reliable, although not equivalent, results. The TW3 height prediction method seemed to be more accurate in patients with {beta}-thalassaemia major than the G and P method, albeit with a large confidence interval. (orig.)

  18. EVALUATION OF SOIL EROSION IN REGHIN HILLS USING THE USLE METHOD

    Directory of Open Access Journals (Sweden)

    J. SZILAGYI

    2016-03-01

    Full Text Available Soil erosion is one of the main causes of degradation of large areas of agricultural land, causing great economic loss by removing fertile soil. The Universal Soil Loss Equation (USLE predicts the long term average annual rate of erosion on a field slope based on rainfall pattern, soil type, topography, crop system and management practices but does not however predict the soil loss resulting from gully erosion.

  19. A terminological matter: paragenesis, antigravitative erosion or antigravitational erosion ?

    Directory of Open Access Journals (Sweden)

    Pasini G.

    2009-07-01

    Full Text Available In the speleological literature three terms are utilized to designate the “ascending erosion”: paragenesis (= paragénésis, coined in1968, antigravitative erosion (= erosione antigravitativa, coined in 1966 and antigravitational erosion (wrong English translation ofthe Italian term erosione antigravitativa, utilized later on. The term paragenesis should be abandoned because of the priority of theterm erosione antigravitativa - on the ground of the “law of priority” – and because of its ambiguous etimology. On the other hand,the term antigravitational erosion should be forsaken in favour of the term antigravitative erosion, given the meaning that the termsgravitation and gravity have in Physics. Therefore, to designate the phenomenon of the “ascending erosion” there would be nothingleft but the term antigravitative erosion.The antigravitative erosion process and its recognizability are illustrated.Examples of caves with evident antigravitative erosion phenomena, developed in different karstifiable rocks and in several partsof the world, are given.It is recalled that the antigravitative erosion is a phenomenon well-known since 1942 and widely proven and supported, and that it isrelatively easy – in many cases - to recognize the antigravitative origin of karstic passages.It is stressed that the antigravitative erosion is an important phenomenon, exclusive of the karstic caves and unique in nature.

  20. Erosive potential of soft drinks on human enamel: An in vitro study

    Directory of Open Access Journals (Sweden)

    Yin-Lin Wang

    2014-11-01

    Conclusion: All tested soft drinks were found to be erosive. Soft drinks with high calcium contents have significantly lower erosive potential. Low pH value and high citrate content may cause more surface enamel loss. As the erosive time increased, the titratable acidity to pH 7 may be a predictor of the erosive potential for acidic soft drinks. The erosive potential of the soft drinks may be predicted based on the types of acid content, pH value, titratable acidity, and ion concentration.

  1. The influence of material hardness on liquid droplet impingement erosion

    International Nuclear Information System (INIS)

    Fujisawa, Nobuyuki; Yamagata, Takayuki; Takano, Shotaro; Saito, Kengo; Morita, Ryo; Fujiwara, Kazutoshi; Inada, Fumio

    2015-01-01

    Highlights: • Liquid droplet impingement erosion is studied for various metal materials. • Average power dependency on droplet velocity is found as 7. • Power dependency on Vickers hardness is found as −4.5. • An empirical formula is constructed for erosion rates of metal materials. • Predicted erosion rate is well correlated with experiment within a factor of 1.5. - Abstract: This paper describes the experimental study on the liquid droplet impingement erosion of metal materials to understand the influence of material hardness on the erosion rate. The experiment is carried out using a water spray jet apparatus with a condition of relatively thin liquid film thickness. The metal materials tested are pure aluminum, aluminum alloy, brass, mild steel, carbon steel and stainless steel. The liquid droplets considered are 30 ± 5 μm in volume average diameter of water, which is the same order of droplet diameter in the actual pipeline in nuclear/fossil power plants. In order to understand the influence of material hardness on the liquid droplet impingement erosion, the scanning electron microscope (SEM) observation on the eroded surface and the measurement of erosion rate are carried out in the terminal stage of erosion. The experimental results indicate that the erosion rates are expressed by the droplet velocity, volume flux, Vickers hardness and the liquid film thickness, which are fundamentals of the liquid droplet impingement erosion. The empirical formula shows that the power index for droplet velocity dependency is found to be 7 with a scattering from 5 to 9 depending on the materials, while the power index for Vickers hardness dependency is found as −4.5

  2. Headcut erosive regimes influenced by groundwater on disturbed agricultural soils.

    Science.gov (United States)

    Rockwell, D L

    2011-02-01

    A series of simulated rainfall experiments, testing several soils and slope gradients in a 10 m x 0.8m laboratory flume, displayed close correlations between initial development of a water table at a 10 cm depth and highly erosive headcut formation. On some soils and gradients, highly erosive headcuts formed consistently and predictably within minutes or seconds of initial water table rise. However, headcuts alone were not good indicators of increased erosion. In most experiments some headcuts formed early, often when surface hydraulic parameter values reached established rill initiation thresholds, but resulted in little or no erosion increase. Later, at initial water table rise, other headcuts formed coincident with major erosion increase, often with surface hydraulic values then less than rill initiation thresholds. On the four soils tested, highly erosive headcuts never formed without groundwater development, except on steep 9 ° slopes. Common visual indicators such as headcut morphology and headcut advance rates were not effective means of determining either erosion or the existence of groundwater. Only local monitoring of subsurface moisture conditions with micro-standpipes and TDR aided in determining headcut processes and erosive regimes. Groundwater-influenced headcut formation was likely caused by increased soil pore-water pressures and decreased soil shear strengths in surface rainflow, not by sapping or seepage from the soil matrix. Highly erosive headcuts can thus form under common agricultural conditions where reductions in permeability, such as plow pans, exist near the surface--without the need for saturated soils. Headcut erosive regimes were also significantly influenced by soil type and slope gradient, with the greatest effects of groundwater on moderate slopes and fairly permeable soils. Copyright © 2010. Published by Elsevier Ltd.

  3. The influence of material hardness on liquid droplet impingement erosion

    Energy Technology Data Exchange (ETDEWEB)

    Fujisawa, Nobuyuki, E-mail: fujisawa@eng.niigata-u.ac.jp [Visualization Research Center, Niigata University, 8050, Ikarashi 2-Nocho, Nishi-ku, Niigata 950-2181 (Japan); Yamagata, Takayuki, E-mail: yamagata@eng.niigata-u.ac.jp [Visualization Research Center, Niigata University, 8050, Ikarashi 2-Nocho, Nishi-ku, Niigata 950-2181 (Japan); Takano, Shotaro; Saito, Kengo [Graduate School of Science and Technology, Niigata University, 8050, Ikarashi 2-Nocho, Nishi-ku, Niigata 950-2181 (Japan); Morita, Ryo; Fujiwara, Kazutoshi; Inada, Fumio [Central Research Institute of Electric Power Industry, 2-11-1, Iwatokita, Komae, Tokyo 201-8511 (Japan)

    2015-07-15

    Highlights: • Liquid droplet impingement erosion is studied for various metal materials. • Average power dependency on droplet velocity is found as 7. • Power dependency on Vickers hardness is found as −4.5. • An empirical formula is constructed for erosion rates of metal materials. • Predicted erosion rate is well correlated with experiment within a factor of 1.5. - Abstract: This paper describes the experimental study on the liquid droplet impingement erosion of metal materials to understand the influence of material hardness on the erosion rate. The experiment is carried out using a water spray jet apparatus with a condition of relatively thin liquid film thickness. The metal materials tested are pure aluminum, aluminum alloy, brass, mild steel, carbon steel and stainless steel. The liquid droplets considered are 30 ± 5 μm in volume average diameter of water, which is the same order of droplet diameter in the actual pipeline in nuclear/fossil power plants. In order to understand the influence of material hardness on the liquid droplet impingement erosion, the scanning electron microscope (SEM) observation on the eroded surface and the measurement of erosion rate are carried out in the terminal stage of erosion. The experimental results indicate that the erosion rates are expressed by the droplet velocity, volume flux, Vickers hardness and the liquid film thickness, which are fundamentals of the liquid droplet impingement erosion. The empirical formula shows that the power index for droplet velocity dependency is found to be 7 with a scattering from 5 to 9 depending on the materials, while the power index for Vickers hardness dependency is found as −4.5.

  4. Erosion in extruder flow

    Science.gov (United States)

    Kaufman, Miron; Fodor, Petru S.

    A detailed analysis of the fluid flow in Tadmor's unwound channel model of the single screw extruder is performed by combining numerical and analytical methods. Using the analytical solution for the longitudinal velocity field (in the limit of zero Reynolds number) allows us to devote all the computational resources solely for a detailed numerical solution of the transversal velocity field. This high resolution 3D model of the fluid flow in a single-screw extruder allows us to identify the position and extent of Moffatt eddies that impede mixing. We further consider the erosion of particles (e.g. carbon-black agglomerates) advected by the polymeric flow. We assume a particle to be made of primary fragments bound together. In the erosion process a primary fragment breaks out of a given particle. Particles are advected by the laminar flow and they disperse because of the shear stresses imparted by the fluid. The time evolution of the numbers of particles of different sizes is described by the Bateman coupled differential equations used to model radioactivity. Using the particle size distribution we compute an entropic fragmentation index which varies from 0 for a monodisperse system to 1 for an extreme poly-disperse system.

  5. Preliminary study for predicting better methotrexate efficacy in Japanese patients with rheumatoid arthritis

    OpenAIRE

    Hashiguchi, Masayuki; Tsuru, Tomomi; Miyawaki, Kumika; Suzaki, Midori; Hakamata, Jun; Shimizu, Mikiko; Irie, Shin; Mochizuki, Mayumi

    2016-01-01

    Background Rheumatoid arthritis (RA) is a chronic autoimmune disease characterized by systemic inflammatory status, joint destruction, disability, and pain. Methotrexate (MTX) has been confirmed to reduce disease activity and delay or stabilize the development of bone erosions. However, major drawbacks are that patients show great interindividual variability in response to MTX and the unpredictable occurrence of side effects. A strategy for personalized MTX treatment to predict its efficacy a...

  6. Biochemical markers for prediction of 4-year response in bone mass during bisphosphonate treatment for prevention of postmenopausal osteoporosis

    DEFF Research Database (Denmark)

    Ravn, Pernille; Thompson, Desmond E; Ross, Philip D

    2003-01-01

    measured at 6-month intervals. The correlation between 6-month change in uCTX and 4-year change in spine and hip bone mineral density (BMD) was r = -0.41 and r = -0.42, respectively (P r = -0.53 and r = -0.42 (uNTX), r = -0.46 and r = -0.......47 [total OC (ELISA)], and r = -0.43 and r = -0.41 [total OC (RIA)], all P

  7. Optimization the initial weights of artificial neural networks via genetic algorithm applied to hip bone fracture prediction

    OpenAIRE

    Chang, Y-T; Lin, J; Shieh, J-S; Abbod, MF

    2012-01-01

    This paper aims to find the optimal set of initial weights to enhance the accuracy of artificial neural networks (ANNs) by using genetic algorithms (GA). The sample in this study included 228 patients with first low-trauma hip fracture and 215 patients without hip fracture, both of them were interviewed with 78 questions. We used logistic regression to select 5 important factors (i.e., bone mineral density, experience of fracture, average hand grip strength, intake of coffee, and peak expirat...

  8. Instrumentation and methods evaluations for shallow land burial of waste materials: water erosion

    International Nuclear Information System (INIS)

    Hostetler, D.D.; Murphy, E.M.; Childs, S.W.

    1981-08-01

    The erosion of geologic materials by water at shallow-land hazardous waste disposal sites can compromise waste containment. Erosion of protective soil from these sites may enhance waste transport to the biosphere through water, air, and biologic pathways. The purpose of this study was to review current methods of evaluating soil erosion and to recommend methods for use at shallow-land, hazardous waste burial sites. The basic principles of erosion control are: minimize raindrop impact on the soil surface; minimize runoff quantity; minimize runoff velocity; and maximize the soil's resistance to erosion. Generally soil erosion can be controlled when these principles are successfully applied at waste disposal sites. However, these erosion control practices may jeopardize waste containment. Typical erosion control practices may enhance waste transport by increasing subsurface moisture movement and biologic uptake of hazardous wastes. A two part monitoring program is recommended for US Department of Energy (DOE) hazardous waste disposal sites. The monitoring programs and associated measurement methods are designed to provide baseline data permitting analysis and prediction of long term erosion hazards at disposal sites. These two monitoring programs are: (1) site reconnaissance and tracking; and (2) site instrumentation. Some potential waste transport problems arising from erosion control practices are identified. This report summarizes current literature regarding water erosion prediction and control

  9. Soil erosion assessment on hillslope of GCE using RUSLE model

    Science.gov (United States)

    Islam, Md. Rabiul; Jaafar, Wan Zurina Wan; Hin, Lai Sai; Osman, Normaniza; Din, Moktar Aziz Mohd; Zuki, Fathiah Mohamed; Srivastava, Prashant; Islam, Tanvir; Adham, Md. Ibrahim

    2018-06-01

    A new method for obtaining the C factor (i.e., vegetation cover and management factor) of the RUSLE model is proposed. The method focuses on the derivation of the C factor based on the vegetation density to obtain a more reliable erosion prediction. Soil erosion that occurs on the hillslope along the highway is one of the major problems in Malaysia, which is exposed to a relatively high amount of annual rainfall due to the two different monsoon seasons. As vegetation cover is one of the important factors in the RUSLE model, a new method that accounts for a vegetation density is proposed in this study. A hillslope near the Guthrie Corridor Expressway (GCE), Malaysia, is chosen as an experimental site whereby eight square plots with the size of 8× 8 and 5× 5 m are set up. A vegetation density available on these plots is measured by analyzing the taken image followed by linking the C factor with the measured vegetation density using several established formulas. Finally, erosion prediction is computed based on the RUSLE model in the Geographical Information System (GIS) platform. The C factor obtained by the proposed method is compared with that of the soil erosion guideline Malaysia, thereby predicted erosion is determined by both the C values. Result shows that the C value from the proposed method varies from 0.0162 to 0.125, which is lower compared to the C value from the soil erosion guideline, i.e., 0.8. Meanwhile predicted erosion computed from the proposed C value is between 0.410 and 3.925 t ha^{-1 } yr^{-1} compared to 9.367 to 34.496 t ha^{-1} yr^{-1 } range based on the C value of 0.8. It can be concluded that the proposed method of obtaining a reasonable C value is acceptable as the computed predicted erosion is found to be classified as a very low zone, i.e. less than 10 t ha^{-1 } yr^{-1} whereas the predicted erosion based on the guideline has classified the study area as a low zone of erosion, i.e., between 10 and 50 t ha^{-1 } yr^{-1}.

  10. An Updated Look at the Pro K Experiment: Urinary Acid Excretion Can Predict Changes in Bone Metabolism During Space Flight

    Science.gov (United States)

    Zwart, Sara R.; Heer, Martina; Shackelford, Linda; Smith, Scott M.

    2015-01-01

    Mitigating space flight-induced bone loss is critical for space exploration, and diet can play a major role in this effort (1). Previous ground-based studies provide evidence that dietary composition can influence bone resorption during bed rest (2). In this study we examined the role of dietary intake patterns as one factor that can influence bone mineral loss in astronauts during space flight. Crew members were asked to consume, for 4 days at a time, prescribed menus with either a low (0.3-0.6 g/mEq) or high (1.0-1.3 g/mEq) ratio of animal protein to potassium (APro:K). Menus were developed for each crewmember, and were designed to meet both crew preferences and study constraints. Intakes of energy, total protein, calcium, and sodium were held relatively constant between the two diets. The order of the menus was randomized, and crews completed each set (low and high) once before and twice during space flight, for a total of 6 controlled diet sessions. One inflight session and three postflight sessions (R+30, R+180, R+365) monitored typical dietary intake. As of this writing, data are available from 14 crew members. Two subject's samples are awaiting return from ISS via Space-X, and the final subject has one more collection session planned in November 2014. On the last day of each of the 4-d controlled diet sessions, 24-h urine samples were collected, along with a fasting blood sample on the morning of the 5th day. Preliminary analyses will show the relationships between diet and flight on markers of bone metabolism. The results from this study, which represent healthy individuals in a unique environment, will be important to better understand diet and bone interrelationships during space flight as well as on Earth. These data will be important as nutritional requirements and food systems are developed for future exploration-class missions. This study was funded by the Human Health Countermeasures Element of NASA Human Research Program.

  11. The erosive potential of lollipops

    NARCIS (Netherlands)

    Brand, H.S.; Gambon, D.L.; Paap, A.; Bulthuis, M.S.; Veerman, E.C.I.; Nieuw Amerongen, A.V.

    2009-01-01

    Aim: To determine the erosive potential of several commercially available lollipops and the protective effect of saliva. Methods: The erosive potential of lollipops was determined in vitro by measuring the pH and neutralisable acidity. Subsequently, 10 healthy volunteers tested different types of

  12. Wind erosion processes and control

    Science.gov (United States)

    Wind erosion continues to threaten the sustainability of our nations' soil, air, and water resources. To effectively apply conservation systems to prevent wind driven soil loss, an understanding of the fundamental processes of wind erosion is necessary so that land managers can better recognize the ...

  13. Erosion--corrosion

    International Nuclear Information System (INIS)

    Vyas, B.

    1978-01-01

    The deterioration of materials by corrosion or erosion by itself presents a formidable problem and for this reason investigators have studied these two phenomena independently. In fact, there are very few systematic studies on E-C and the majority of references mention it only in passing. In most real systems, however, the two destructive processes take place simultaneously, hence the purpose of this review is to present the various interactions between the chemical and mechanical agents leading to accelerated degradation of the material. The papers cited in the review are those that lead to a better understanding of the process involved in the accelerated rate of material loss under E-C conditions

  14. Soil erosion assessment in the core area of the Loss Plateau

    Science.gov (United States)

    Yang, Bo; Wang, Quanjiu

    2017-11-01

    In order to explore the spatiotemporal evolution of erosion and sediment yield before and after Grain for Green Project in the Loss Plateau. The soil loss of Yulin is estimated by Chinese Water Erosion on Hill Slope Prediction Model. The result shows that the spatiotemporal variations of soil erosion are largely related to rainfall erosion distribution, slope, and land use type. The overall soil erosion categories in the south region are higher than that of the northwest. Mid slopes and valleys are the major topographical contributors to soil erosion. With the growth of slope gradient, soil erosion significantly increased. The soil loss has a decreasing tendency after Grain for Green Project. The results indicate that the vegetation restoration as part of the Grain for Green Project on the Loess Plateau is effective.

  15. Bone disease in primary hyperparathyroidism

    Science.gov (United States)

    Bandeira, Francisco; Cusano, Natalie E.; Silva, Barbara C.; Cassibba, Sara; Almeida, Clarissa Beatriz; Machado, Vanessa Caroline Costa; Bilezikian, John P.

    2015-01-01

    Bone disease in severe primary hyperparathyroidism (PHPT) is described classically as osteitis fibrosa cystica (OFC). Bone pain, skeletal deformities and pathological fractures are features of OFC. Bone mineral density is usually extremely low in OFC, but it is reversible after surgical cure. The signs and symptoms of severe bone disease include bone pain, pathologic fractures, proximal muscle weakness with hyperreflexia. Bone involvement is typically characterized as salt-and-pepper appearance in the skull, bone erosions and bone resorption of the phalanges, brown tumors and cysts. In the radiography, diffuse demineralization is observed, along with pathological fractures, particularly in the long bones of the extremities. In severe, symptomatic PHPT, marked elevation of the serum calcium and PTH concentrations are seen and renal involvement is manifested by nephrolithiasis and nephrocalcinosis. A new technology, recently approved for clinical use in the United States and Europe, is likely to become more widely available because it is an adaptation of the lumbar spine DXA image. Trabecular bone score (TBS) is a gray-level textural analysis that provides an indirect index of trabecular microarchitecture. Newer technologies, such as high-resolution peripheral quantitative computed tomography (HR-pQCT), have provided further understanding of the microstructural skeletal features in PHPT. PMID:25166047

  16. Methods for assessing mine site rehabilitation design for erosion impact

    International Nuclear Information System (INIS)

    Evans, K. G.

    2000-01-01

    Erosion of rehabilitated mines may result in landform instability, which in turn may result in exposure of encapsulated contaminants, elevated sediment delivery at catchment outlets, and subsequent degradation of downstream water quality. Rehabilitation design can be assessed using erosion and hydrology models calibrated to mine site conditions. Incision rates in containment structures can be quantified using 3-dimensional landform evolution simulation techniques. Sediment delivery at catchment outlets for various landform amelioration techniques can be predicted using process-based and empirical erosion-prediction models and sediment delivery ratios. The predicted sediment delivery can be used to estimate an average annual stream sediment load that can, in turn, be used to assess water quality impacts. Application of these techniques is demonstrated through a case study applied to a proposed rehabilitation design option for the Energy Resources of Australia Ltd (ERA) Ranger Mine in the Northern Territory of Australia. Copyright (2000) CSIRO Australia

  17. Using REE tracers to measure sheet erosion changing to rill erosion

    International Nuclear Information System (INIS)

    Liu Puling; Xue Yazhou; Song Wei; Wang Mingyi; Ju Tongjun

    2004-01-01

    Rare Earth Elements (REE) tracer method was used to study sheet erosion changing to rill erosion on slope land. By placing different rare earth elements of different soil depth across a slope in an indoor plot, two simulated rainfalls were applied to study the change of erosion type and the rill erosion process. The results indicate that the main erosion type is sheet erosion at the beginning of the rainfalls, and serious erosion happens after rill erosion appears. Accumulated sheet and rill erosion amounts increase with the rainfalls time. The percentage of sheet erosion amount decreases and rill erosion percentage increases with time. At the end of the rainfalls, the total rill erosion amounts are 4-5 times more than sheet erosion. In this paper, a new REE tracer method was used to quantitatively distinguish sheet and rill erosion amounts. The new REE tracer method should be useful to future studying of erosion processes on slope lands. (authors)

  18. Theoretical prediction and experimental determination of the effect of mold characteristics on temperature and monomer conversion fraction profiles during polymerization of a PMMA-based bone cement.

    Science.gov (United States)

    Vallo, Claudia I

    2002-01-01

    The present work is concerned with applications of a kinetic model for free-radical polymerization of a polymethylmethacrylate-based bone cement. Autocatalytic behavior at the first part of the reaction as well as a diffusion control phenomenon near vitrification are described by the model. Comparison of theoretical computations with experimental measurements for the temperature evolution during batch casting demonstrated the capacity of the proposed model to represent the kinetic behavior of the polymerization reaction. Temperature evolution and monomer conversion were simulated for the cure of the cement in molds made of different materials. The maximum monomer conversion fraction was markedly influenced by the physical properties of the mold material. The unreacted monomer acts as a plasticizer that influences the mechanical behavior of the cement. Hence, the same cement formulation cured in molds of different materials may result in different mechanical response because of the differences in the amounts of residual monomer. Standardization of the mold type to prepare specimens for the mechanical characterization of bone cements is recommended. Theoretical prediction of temperature evolution during hip replacement indicated that for cement thickness lower than 6 mm the peak temperature at the bone-cement interface was below the limit stated for thermal injury (50 degrees C for more than 1 min). The use of thin cement layers is recommended to diminish the risk of thermal injury; however, it is accompanied by an increase in the amount of unreacted monomer present in the cured material. Copyright 2002 Wiley Periodicals, Inc. J Biomed Mater Res (Appl Biomater) 63: 627-642, 2002

  19. Simulation of erosion in drilling tools for oil and gas industry

    Energy Technology Data Exchange (ETDEWEB)

    Arefi, B.; Settari, A. [Calgary Univ., AB (Canada); Angman, P. [Tesco Corp., Calgary, AB (Canada)

    2004-07-01

    Erosion in oil well drilling tools is a form of wear which occurs when fluid containing solid particles impacts a solid surface. The intensity of erosion is generally measured as the rate of material removal from the surface, and is expressed as E{sub r}, the weight of material removed by unit weight of impacting particles. Erosion can also be reduced by tool improvement and modification, thereby extending the life of drilling tools. To date, no attempt has been made to model the erosion phenomenon in drilling tools. This paper presents a newly developed erosion simulator which is the first design tool for the drilling industry. This work demonstrates that erosion can be simulated. A model was developed to calibrate the erosion coefficients for drilling tool conditions. The mechanism of erosion can be controlled by the impact velocity and angle. Algorithms were developed for transient simulation of the erosion of any surface in 2-dimensional geometry. The Erosion Simulator has been validated and calibrated against data provided by TESCO Corporation's casing drilling tools. The model has been shown to successfully predict and minimize erosion by modifying the tool geometry and metallurgy. 21 refs., 1 tab., 15 figs.

  20. Towards estimates of future rainfall erosivity in Europe based on REDES and WorldClim datasets

    Science.gov (United States)

    Panagos, Panos; Ballabio, Cristiano; Meusburger, Katrin; Spinoni, Jonathan; Alewell, Christine; Borrelli, Pasquale

    2017-05-01

    The policy requests to develop trends in soil erosion changes can be responded developing modelling scenarios of the two most dynamic factors in soil erosion, i.e. rainfall erosivity and land cover change. The recently developed Rainfall Erosivity Database at European Scale (REDES) and a statistical approach used to spatially interpolate rainfall erosivity data have the potential to become useful knowledge to predict future rainfall erosivity based on climate scenarios. The use of a thorough statistical modelling approach (Gaussian Process Regression), with the selection of the most appropriate covariates (monthly precipitation, temperature datasets and bioclimatic layers), allowed to predict the rainfall erosivity based on climate change scenarios. The mean rainfall erosivity for the European Union and Switzerland is projected to be 857 MJ mm ha-1 h-1 yr-1 till 2050 showing a relative increase of 18% compared to baseline data (2010). The changes are heterogeneous in the European continent depending on the future projections of most erosive months (hot period: April-September). The output results report a pan-European projection of future rainfall erosivity taking into account the uncertainties of the climatic models.

  1. Towards estimates of future rainfall erosivity in Europe based on REDES and WorldClim datasets.

    Science.gov (United States)

    Panagos, Panos; Ballabio, Cristiano; Meusburger, Katrin; Spinoni, Jonathan; Alewell, Christine; Borrelli, Pasquale

    2017-05-01

    The policy requests to develop trends in soil erosion changes can be responded developing modelling scenarios of the two most dynamic factors in soil erosion, i.e. rainfall erosivity and land cover change. The recently developed Rainfall Erosivity Database at European Scale (REDES) and a statistical approach used to spatially interpolate rainfall erosivity data have the potential to become useful knowledge to predict future rainfall erosivity based on climate scenarios. The use of a thorough statistical modelling approach (Gaussian Process Regression), with the selection of the most appropriate covariates (monthly precipitation, temperature datasets and bioclimatic layers), allowed to predict the rainfall erosivity based on climate change scenarios. The mean rainfall erosivity for the European Union and Switzerland is projected to be 857 MJ mm ha -1  h -1  yr -1 till 2050 showing a relative increase of 18% compared to baseline data (2010). The changes are heterogeneous in the European continent depending on the future projections of most erosive months (hot period: April-September). The output results report a pan-European projection of future rainfall erosivity taking into account the uncertainties of the climatic models.

  2. Gastric Mucosal Erosions - Radiologic evaluation -

    International Nuclear Information System (INIS)

    Kim, Seung Hyup

    1985-01-01

    70 cases of gastric mucosal erosions were diagnosed by double contrast upper gastrointestinal examinations and endoscopic findings. Analyzing the radiologic findings of these 70 cases of gastric mucosal erosions, the following results were obtained. 1. Among the total 70 cases, 65 cases were typical varioliform erosions showing central depressions and surrounding mucosal elevations. Remaining 5 cases were erosions of acute phase having multiple irregular depressions without surrounding elevations. 2. The gastric antrum was involved alone or in part in all cases. Duodenal bulb was involved with gastric antrum in 4 cases. 3. The majority of the cases had multiple erosions. There were only 2 cases of single erosion. 4. In 65 cases of varioliform erosions; 1) The diameter of the surrounding elevations varied from 3 to 20 mm with the majority (47 cases) between 6 and 10 mm. 2) In general, the surrounding elevations with sharp margin on double contrast films were also clearly demonstrated on compression films but those with faint margin were not. 3) The size of the central barium collections varied from pinpoint to 10 mm with the majority under 5 mm. The shape of the central barium collections in majority of the cases were round with a few cases of linear, triangular or star-shape. 5. In 5 cases of acute phase erosions; 1) All the 5 cases were females. 2) On double contrast radiography, all the cases showed multiple irregular depressed lesions without surrounding elevations. 3) 1 case had the history of hematemesis. 4) In 1 case, there was marked radiological improvement on follow-up study of 2 months interval. 6. In 23 cases, there were coexistent diseases with gastric mucosal erosions. These were 13 cases of duodenal bulb ulcers,7 cases of benign gastric ulcers and 3 others

  3. Dune Erosion Models and Swash Zone Kinematics from Remote Video Observations

    Science.gov (United States)

    2010-12-09

    system. Thus, successful prediction of dune erosion requires knowledge of the expected trajectory of the eroding dune toe . If we describe the... dune toe trajectory as following a slope, βT, two end member retreat trajectories exist. The first would be direct landward erosion so that zb never...changes     0 0   T bb ztz  (2.24) The second end member trajectory is that erosion moves the dune toe directly up the foreshore slope

  4. Estimations of bone maturation and calculations of prediction of adult height as tools for the evaluation of growth disorders

    Energy Technology Data Exchange (ETDEWEB)

    Zachmann, M

    1982-03-01

    The methods of estimation of bone maturation (Greulich and Pyle, Tanner et al.) and the possibilities for the calculation of future adult heigth (Bayley and Pinneau, Roche et al., Tanner et al.) are briefly described and their advantages and disadvantages in normal children and in children with growth disorders are discussed. In normal children, all methods provide valuable results, but there are small differences of precision depending on whether the pubertal development is early, average, or late. In pathological conditions, however, as e.g. in precocious puberty or in girls with Turner syndrome, the methods of Roche et al. and of Tanner et al. may overestimate adult height considerably, while that of Bayley and Pinneau remains reasonably accurate. A computerized system, which facilitates the complicated and time-consuming calculations is briefly presented.

  5. Soil erosion, sedimentation and the carbon cycle

    Science.gov (United States)

    Cammeraat, L. H.; Kirkels, F.; Kuhn, N. J.

    2012-04-01

    Historically soil erosion focused on the effects of on-site soil quality loss and consequently reduced crop yields, and off-site effects related to deposition of material and water quality issues such as increased sediment loads of rivers. In agricultural landscapes geomorphological processes reallocate considerable amounts of soil and soil organic carbon (SOC). The destiny of SOC is of importance because it constitutes the largest C pool of the fast carbon cycle, and which cannot only be understood by looking at the vertical transfer of C from soil to atmosphere. Therefore studies have been carried out to quantify this possible influence of soil erosion and soil deposition and which was summarized by Quinton et al. (2010) by "We need to consider soils as mobile systems to make accurate predictions about the consequences of global change for terrestrial biogeochemical cycles and climate feedbacks". Currently a debate exists on the actual fate of SOC in relation to the global carbon cycle, represented in a controversy between researchers claiming that erosion is a sink, and those who claim the opposite. This controversy is still continuing as it is not easy to quantify and model the dominating sink and source processes at the landscape scale. Getting insight into the balance of the carbon budget requires a comprehensive research of all relevant processes at broad spatio-temporal scales, from catchment to regional scales and covering the present to the late Holocene. Emphasising the economic and societal benefits, the merits for scientific knowledge of the carbon cycle and the potential to sequester carbon and consequently offset increasing atmospheric CO2 concentrations, make the fate of SOC in agricultural landscapes a high-priority research area. Quinton, J.N., Govers, G., Van Oost, K., Bardgett, R.D., 2010. The impact of agricultural soil erosion on biogeochemical cycling. Nature Geosci, 3, 311-314.

  6. How well does the Post-fire Erosion Risk Management Tool (ERMiT) really work?

    Science.gov (United States)

    Robichaud, Peter; Elliot, William; Lewis, Sarah; Miller, Mary Ellen

    2016-04-01

    The decision of where, when, and how to apply the most effective postfire erosion mitigation treatments requires land managers to assess the risk of damaging runoff and erosion events occurring after a fire. The Erosion Risk Management Tool (ERMiT) was developed to assist post fire assessment teams identify high erosion risk areas and effectiveness of various mitigation treatments to reduce that risk. ERMiT is a web-based application that uses the Water Erosion Prediction Project (WEPP) technology to estimate erosion, in probabilistic terms, on burned and recovering forest, range, and chaparral lands with and without the application of mitigation treatments. User inputs are processed by ERMiT to combine rain event variability with spatial and temporal variabilities of hillslope burn severity and soil properties which are then used as WEPP inputs. Since 2007, the model has been used in making hundreds of land management decisions in the US and elsewhere. We use eight published field study sites in the Western US to compare ERMiT predictions to observed hillslope erosion rates. Most sites experience only a few rainfall events that produced runoff and sediment except for a California site with a Mediterranean climate. When hillslope erosion occurred, significant correlations occurred between the observed hillslope erosion and those predicted by ERMiT. Significant correlation occurred for most mitigation treatments as well as the five recovery years. These model validation results suggest reasonable estimates of probabilistic post-fire hillslope sediment delivery when compared to observation.

  7. Predictive value of [18F]-fluoride PET for monitoring bone remodeling in patients with orthopedic conditions treated with a Taylor spatial frame.

    Science.gov (United States)

    Sanchez-Crespo, Alejandro; Christiansson, Frederik; Thur, Charlotte Karlsson; Lundblad, Henrik; Sundin, Anders

    2017-03-01

    The Taylor Spatial Frame (TSF) is used to correct orthopedic conditions such as correction osteotomies in delayed fracture healing and pseudarthrosis. Long-term TSF-treatments are common and may lead to complications. Current conventional radiological methods are often unsatisfactory for therapy monitoring. Hence, an imaging technique capable of quantifying bone healing progression would be advantageous. A cohort of 24 patients with different orthopedic conditions, pseudarthrosis (n = 10), deformities subjected to correction osteotomy (n = 9), and fracture (n = 5) underwent dynamic [ 18 F]-fluoride (Na 18 F) PET/CT at 8 weeks and 4 months, respectively, after application of a TSF. Parametric images, corresponding to the net transport rate of [ 18 F]-fluoride from plasma to bone, K i were calculated. The ratio of the maximum K i at PET scan 2 and 1 ([Formula: see text]) as well as the ratio of the maximum Standard Uptake Value at PET scan 2 and 1 ([Formula: see text]) were calculated for each individual. Different treatment end-points were scored, and the overall treatment outcome score was compared with the osteoblastic activity progression as scored with [Formula: see text] or [Formula: see text]. [Formula: see text] and [Formula: see text] were not correlated within each orthopedic group (p > 0.1 for all groups), nor for the pooled population (p = 0.12). The distribution of [Formula: see text] was found significantly different among the different orthopedic groups (p = 0.0046) -also for [Formula: see text] (p = 0.022). The positive and negative treatment predictive values for [Formula: see text] were 66.7 % and 77.8 %, respectively. Corresponding values for [Formula: see text] were 25 % and 33.3 % CONCLUSIONS: The [Formula: see text] obtained from dynamic [ 18 F]-fluoride-PET imaging is a promising predictive factor to evaluate changes in bone healing in response to TSF treatment.

  8. Predictive value of [{sup 18}F]-fluoride PET for monitoring bone remodeling in patients with orthopedic conditions treated with a Taylor spatial frame

    Energy Technology Data Exchange (ETDEWEB)

    Sanchez-Crespo, Alejandro [Karolinska University Hospital, Department of Hospital Physics, Nuclear Medicine, Stockholm (Sweden); Karolinska University Hospital, Stockholm (Sweden); Christiansson, Frederik [Nykoepings Hospital, Department of Radiology, Nykoeping (Sweden); Karlsson Thur, Charlotte; Lundblad, Henrik [Karolinska Institutet, Department of Molecular Medicine and Surgery, Stockholm (Sweden); Sundin, Anders [Uppsala University Hospital, Department of Radiology and Molecular Imaging, Uppsala (Sweden)

    2017-03-15

    The Taylor Spatial Frame (TSF) is used to correct orthopedic conditions such as correction osteotomies in delayed fracture healing and pseudarthrosis. Long-term TSF-treatments are common and may lead to complications. Current conventional radiological methods are often unsatisfactory for therapy monitoring. Hence, an imaging technique capable of quantifying bone healing progression would be advantageous. A cohort of 24 patients with different orthopedic conditions, pseudarthrosis (n = 10), deformities subjected to correction osteotomy (n = 9), and fracture (n = 5) underwent dynamic [{sup 18}F]-fluoride (Na{sup 18}F) PET/CT at 8 weeks and 4 months, respectively, after application of a TSF. Parametric images, corresponding to the net transport rate of [{sup 18}F]-fluoride from plasma to bone, K{sub i} were calculated. The ratio of the maximum K{sub i} at PET scan 2 and 1 (anti K{sub i,max}) as well as the ratio of the maximum Standard Uptake Value at PET scan 2 and 1 (SUV {sub max}) were calculated for each individual. Different treatment end-points were scored, and the overall treatment outcome score was compared with the osteoblastic activity progression as scored with anti K{sub i,max} or SUV {sub max}. anti K{sub i,max} and SUV {sub max} were not correlated within each orthopedic group (p > 0.1 for all groups), nor for the pooled population (p = 0.12). The distribution of anti K{sub i,max} was found significantly different among the different orthopedic groups (p = 0.0046) - also for SUV {sub max} (p = 0.022). The positive and negative treatment predictive values for anti K{sub i,max} were 66.7 % and 77.8 %, respectively. Corresponding values for SUV {sub max} were 25 % and 33.3 % The anti K{sub i,max} obtained from dynamic [{sup 18}F]-fluoride-PET imaging is a promising predictive factor to evaluate changes in bone healing in response to TSF treatment. (orig.)

  9. Erosive tooth wear in children

    NARCIS (Netherlands)

    Carvalho, T.S.; Lussi, A.; Jaeggi, T.; Gambon, D.L.; Lussi, A.; Ganss, C.

    2014-01-01

    Erosive tooth wear in children is a common condition. Besides the anatomical differences between deciduous and permanent teeth, additional histological differences may influence their susceptibility to dissolution. Considering laboratory studies alone, it is not clear whether deciduous teeth are

  10. Erosion-resistant composite material

    Science.gov (United States)

    Finch, C.B.; Tennery, V.J.; Curlee, R.M.

    A highly erosion-resistant composite material is formed of chemical vapor-deposited titanium diboride on a sintered titanium diboride-nickel substrate. This material may be suitable for use in cutting tools, coal liquefaction systems, etc.

  11. Bone Cancer

    Science.gov (United States)

    Cancer that starts in a bone is uncommon. Cancer that has spread to the bone from another ... more common. There are three types of bone cancer: Osteosarcoma - occurs most often between ages 10 and ...

  12. Bone Diseases

    Science.gov (United States)

    Your bones help you move, give you shape and support your body. They are living tissues that rebuild constantly ... childhood and your teens, your body adds new bone faster than it removes old bone. After about ...

  13. Soil Erosion and Agricultural Sustainability

    Science.gov (United States)

    Montgomery, D. R.

    2009-04-01

    Data drawn from a global compilation of studies support the long articulated contention that erosion rates from conventionally plowed agricultural fields greatly exceed rates of soil production, erosion under native vegetation, and long-term geological erosion. Whereas data compiled from around the world show that soil erosion under conventional agriculture exceeds both rates of soil production and geological erosion rates by up to several orders of magnitude, similar global distributions of soil production and geological erosion rates suggest an approximate balance. Net soil erosion rates in conventionally plowed fields on the order of 1 mm/yr can erode typical hillslope soil profiles over centuries to millennia, time-scales comparable to the longevity of major civilizations. Well-documented episodes of soil loss associated with agricultural activities date back to the introduction of erosive agricultural methods in regions around the world, and stratigraphic records of accelerated anthropogenic soil erosion have been recovered from lake, fluvial, and colluvial stratigraphy, as well as truncation of soil stratigraphy (such as truncated A horizons). A broad convergence in the results from studies based on various approaches employed to study ancient soil loss and rates of downstream sedimentation implies that widespread soil loss has accompanied human agricultural intensification in examples drawn from around the world. While a broad range of factors, including climate variability and society-specific social and economic contexts — such as wars or colonial relationships — all naturally influence the longevity of human societies, the ongoing loss of topsoil inferred from studies of soil erosion rates in conventional agricultural systems has obvious long-term implications for agricultural sustainability. Consequently, modern agriculture — and therefore global society — faces a fundamental question over the upcoming centuries. Can an agricultural system

  14. A comparison of methods in estimating soil water erosion

    Directory of Open Access Journals (Sweden)

    Marisela Pando Moreno

    2012-02-01

    Full Text Available A comparison between direct field measurements and predictions of soil water erosion using two variant; (FAO and R/2 index of the Revised Universal Soil Loss Equation (RUSLE was carried out in a microcatchment o 22.32 km2 in Northeastern Mexico. Direct field measurements were based on a geomorphologic classification of the area; while environmental units were defined for applying the equation. Environmental units were later grouped withir geomorphologic units to compare results. For the basin as a whole, erosion rates from FAO index were statistical!; equal to those measured on the field, while values obtained from the R/2 index were statistically different from the res and overestimated erosion. However, when comparing among geomorphologic units, erosion appeared overestimate! in steep units and underestimated in more flat areas. The most remarkable differences on erosion rates, between th( direct and FAO methods, were for those units where gullies have developed, fn these cases, erosion was underestimated by FAO index. Hence, it is suggested that a weighted factor for presence of gullies should be developed and included in RUSLE equation.

  15. Modelling Soil Erosion in the Densu River Basin Using RUSLE and GIS Tools.

    Science.gov (United States)

    Ashiagbori, G; Forkuo, E K; Laari, P; Aabeyir, R

    2014-07-01

    Soil erosion involves detachment and transport of soil particles from top soil layers, degrading soil quality and reducing the productivity of affected lands. Soil eroded from the upland catchment causes depletion of fertile agricultural land and the resulting sediment deposited at the river networks creates river morphological change and reservoir sedimentation problems. However, land managers and policy makers are more interested in the spatial distribution of soil erosion risk than in absolute values of soil erosion loss. The aim of this paper is to model the spatial distribution of soil erosion in Densu River Basin of Ghana using RUSLE and GIS tools and to use the model to explore the relationship between erosion susceptibility, slope and land use/land cover (LULC) in the Basin. The rainfall map, digital elevation model, soil type map, and land cover map, were input data in the soil erosion model developed. This model was then categorized into four different erosion risk classes. The developed soil erosion map was then overlaid with the slope and LULC maps of the study area to explore their effects on erosion susceptibility of the soil in the Densu River Basin. The Model, predicted 88% of the basin as low erosion risk and 6% as moderate erosion risk, 3% as high erosion risk and 3% as severe risk. The high and severe erosion areas were distributed mainly within the areas of high slope gradient and also sections of the moderate forest LULC class. Also, the areas within the moderate forest LULC class found to have high erosion risk, had an intersecting high erodibility soil group.

  16. Erosion properties of unipolar arcs

    International Nuclear Information System (INIS)

    Chekalin, Eh.K.

    1982-01-01

    Processes modelling the formation of unipolar arcs on the elements of the first wall in limiters of the vacuum chamber and on active elements of tokamak divertor, are experimentally investigated. Erosion, processes that take place at two types of non-stationary cathode spots are considered. Experimental data prove the possibility of reducing erosion intensity by coating the surface of electrodes by oxide films, reduction of the temperature of electrode and discharge current

  17. Influence of anti-cyclic citrullinated peptide on disease activity, structural severity, and bone loss in Moroccan women with rheumatoid arthritis

    Directory of Open Access Journals (Sweden)

    Imad Ghozlani

    2018-04-01

    Full Text Available Aim of the work: The aim of this study was to assess the influence of anti-cyclic citrullinated peptide (anti-CCP on disease activity, radiological severity, functional disability and bone loss in Moroccan women with rheumatoid arthritis (RA. Patients and methods: One hundred and thirty-six women with RA were recruited. Age, weight, height, disease duration and steroids cumulative dose were identified. Anti-CCP and Rheumatoid factor (RF were determined. Disease activity score (DAS28 was assessed and functional repercussion measured by the Health Assessment Questionnaire-disability index (HAQ-DI. Radiological status was assessed by the Sharp/van der Heijde (SvH erosion and narrowing score. Bone mineral density was determined by a Lunar Prodigy Vision Dual-energy X-ray absorptiometry and vertebral fracture assessment was classified using a combination of Genant semi-quantitative approach and morphometry. Results: Patients mean age was 49.6 ± 7.4 years and disease duration 7.7 ± 5 years. 109 (80.1% patients were anti-CCP positive. There was no significant difference in DAS28 between patients with and without anti-CCP. Nevertheless, weight, erythrocyte sedimentation rate (ESR, rheumatoid factor titer and positivity, SvH narrowing and erosion score and osteoporosis were significantly higher in patients with positive anti-CCP. Stepwise regression analysis showed that the presence of anti-CCP was independently associated with osteoporosis and SvH erosion score. Conclusions: Anti-CCP antibodies are strongly predictive for the development of osteoporosis and erosions in Moroccan RA patients. They not only have a valuable role in the disease prognosis prediction but also may be a relevant determinant of bone loss in RA. The presence of these antibodies warrants special attention. Keywords: Rheumatoid arthritis, Anti-cyclic citrullinated peptide, Disease activity, Joint damage, Bone loss

  18. Geometry of the Proximal Phalanx of Hallux and First Metatarsal Bone to Predict Hallux Abducto Valgus: A Radiological Study.

    Science.gov (United States)

    Perez Boal, Eduardo; Becerro de Bengoa Vallejo, Ricardo; Fuentes Rodriguez, Miguel; Lopez Lopez, Daniel; Losa Iglesias, Marta Elena

    2016-01-01

    Hallux abducto valgus (HAV) is one of the most common forefoot deformities in adulthood with a variable prevalence but has been reported as high as 48%. The study proposed that HAV development involves a skeletal parameter of the first metatarsal bone and proximal phalanx hallux (PPH) to determine if the length measurements of the metatarsal and PPH can be used to infer adult HAV. All consecutive patients over 21 years of age with HAV by roentgenographic evaluation were included in a cross-sectional study. The control group included patients without HAV. The study included 160 individuals. We identified and assessed the following radiographic measurements to evaluate HAV: the distances from the medial (LDM), central (LDC), and lateral (LDL) aspects of the base to the corresponding regions of the head of the PPH. The difference between the medial and lateral aspect of PPH was also calculated. The reliability of the variables measured in 40 radiographic films show perfect reliability ranging from 0.941 to 1 with a small error ranging from 0.762 to 0. Also, there were no systematic errors between the two measurements for any variable (P > 0.05). The LDM PPH showed the highest reliability and lowest error. It is more suitable to measure the LDM PPH instead of the LDC PPH when calculating the hallux valgus angle based on our reliability results. When the differences of the medial and lateral PPH are greater, the risk for developing HAV increases.

  19. Wind erosion of soils burned by wildfire

    Science.gov (United States)

    N. S. Wagenbrenner; M. J. Germino; B. K. Lamb; R. B. Foltz; P. R. Robichaud

    2011-01-01

    Wind erosion and aeolian transport processes are largely unstudied in the post-wildfire environment, but recent studies have shown that wind erosion can play a major role in burned landscapes. A wind erosion monitoring system was installed immediately following a wildfire in southeastern Idaho, USA to measure wind erosion from the burned area (Figure 1). This paper...

  20. Lean mass and fat mass predict bone mineral density in middle-aged individuals with noninsulin-requiring type 2 diabetes mellitus.

    Science.gov (United States)

    Moseley, Kendall F; Dobrosielski, Devon A; Stewart, Kerry J; De Beur, Suzanne M Jan; Sellmeyer, Deborah E

    2011-05-01

    Despite high bone mineral density (BMD), persons with type 2 diabetes are at greater risk of fracture. The relationship between body composition and BMD in noninsulin-requiring diabetes is unclear. The aim was to examine how fat and lean mass independently affect the skeleton in this population. Subjects for this cross-sectional analysis were men (n = 78) and women (n = 56) aged 40-65 years (56 ± 6 years) with uncomplicated, noninsulin-requiring type 2 diabetes. Total body fat and lean mass, total body, hip and lumbar spine BMD were measured with dual energy X-ray absorptiometry. Magnetic resonance imaging measured total abdominal, visceral and subcutaneous (SQ) fat. Subjects had normal all-site BMD and were obese to overweight (body mass index 29-41 kg/m(2)) with controlled diabetes (HbA1c women 6·6 ± 1·2%, men 6·7 ± 1·6%). Lean mass was positively associated with total body, hip, femoral neck and hip BMD in both sexes. Fat mass, abdominal total and SQ fat were associated with total body and hip BMD in women. In multivariate analyses adjusted for sex, lean mass significantly predicted total, hip and femoral neck BMD in men and women. In unadjusted models, lean mass continued to predict BMD at these sites in men; fat mass also predicted total body, femoral and hip BMD in women. In men and women with uncomplicated, noninsulin-requiring diabetes, lean mass significantly predicted BMD at the total body, hip and femoral neck. Further research is needed to determine whether acquisition or maintenance of lean mass in T2DM can prevent hip fracture in this at-risk population. © 2011 Blackwell Publishing Ltd.

  1. Three Gorges Reservoir Area: soil erosion under natural condition vs. soil erosion under current land use

    Science.gov (United States)

    Schönbrodt, Sarah; Behrens, Thorsten; Scholten, Thomas

    2010-05-01

    Apparently, the current most prominent human-induced example for large scale environmental impact is the Three Gorges Dam in China. The flooding alongside the Yangtze River, and its tributaries results in a vast loss of settlement and farmland area with productive, fertile valley soils. Due to the associated high land use dynamic on uphill-sites, the soil resources are underlying high land use pressure. Within our study, the soil erosion under natural conditions is compared to the soil erosion under current land use after the impoundment. Both were modeled using the empirical Universal Soil Loss Equation (USLE) which is able to predict long-term annual soil loss with limited data. The database consists of digital terrain data (45 m resolution DEM, erosive slope length based on Monte-Carlo-Aggregation according to Behrens et al. (2008)), field investigations of recent erosion forms, and literature studies. The natural disposition to soil erosion was calculated considering the USLE factors R, S, and K. The soil erosion under current land use was calculated taking into account all USLE factors. The study area is the catchment of the Xiangxi River in the Three Gorges Reservoir area. Within the Xiangxi Catchment (3,200 km²) the highly dynamic backwater area (580 km²), and two micro-scale study sites (Xiangjiaba with 2.8 km², and Quyuan with 88 km²) are considered more detailed as they are directly affected by the river impoundment. Central features of the Xiangxi Catchment are the subtropical monsoon climate, an extremely steep sloping relief (mean slope angle 39°, SD 22.8°) artificially fractured by farmland terraces, and a high soil erodibility (mean K factor 0.37, SD 0.13). On the catchment scale the natural disposition to soil erosion makes up to mean 518.0 t ha-1 a-1. The maximum potential soil loss of 1,730.1 t ha-1 a-1 under natural conditions is reached in the Quyuan site (mean 635.8 t ha-1 a-1) within the backwater area (mean 582.9 t ha-1 a-1). In the

  2. Prediction of bone strength by μCT and MDCT-based finite-element-models: How much spatial resolution is needed?

    Energy Technology Data Exchange (ETDEWEB)

    Bauer, Jan S., E-mail: jsb@tum.de [Department of Radiology, Technische Universität München, Munich (Germany); Department of Radiology, University of California, San Francisco, CA (United States); Max Planck Institute for Extraterrestrial Physics, Garching (Germany); Sidorenko, Irina [Max Planck Institute for Extraterrestrial Physics, Garching (Germany); Mueller, Dirk [Department of Radiology, Universität Köln (Germany); Baum, Thomas [Department of Radiology, Technische Universität München, Munich (Germany); Department of Radiology, University of California, San Francisco, CA (United States); Max Planck Institute for Extraterrestrial Physics, Garching (Germany); Issever, Ahi Sema [Department of Radiology, University of California, San Francisco, CA (United States); Department of Radiology, Charite, Berlin (Germany); Eckstein, Felix [Institute of Anatomy and Musculoskeletal Research, Paracelsus Medical University, Salzburg (Austria); Rummeny, Ernst J. [Department of Radiology, Technische Universität München, Munich (Germany); Link, Thomas M. [Department of Radiology, University of California, San Francisco, CA (United States); Raeth, Christoph W. [Max Planck Institute for Extraterrestrial Physics, Garching (Germany)

    2014-01-15

    Objectives: Finite-element-models (FEM) are a promising technology to predict bone strength and fracture risk. Usually, the highest spatial resolution technically available is used, but this requires excessive computation time and memory in numerical simulations of large volumes. Thus, FEM were compared at decreasing resolutions with respect to local strain distribution and prediction of failure load to (1) validate MDCT-based FEM and to (2) optimize spatial resolution to save computation time. Materials and methods: 20 cylindrical trabecular bone specimens (diameter 12 mm, length 15–20 mm) were harvested from elderly formalin-fixed human thoracic spines. All specimens were examined by micro-CT (isotropic resolution 30 μm) and whole-body multi-row-detector computed tomography (MDCT, 250 μm × 250 μm × 500 μm). The resolution of all datasets was lowered in eight steps to ∼2000 μm × 2000 μm × 500 μm and FEM were calculated at all resolutions. Failure load was determined by biomechanical testing. Probability density functions of local micro-strains were compared in all datasets and correlations between FEM-based and biomechanically measured failure loads were determined. Results: The distribution of local micro-strains was similar for micro-CT and MDCT at comparable resolutions and showed a shift toward higher average values with decreasing resolution, corresponding to the increasing apparent trabecular thickness. Small micro-strains (ε{sub eff} < 0.005) could be calculated down to 250 μm × 250 μm × 500 μm. Biomechanically determined failure load showed significant correlations with all FEM, up to r = 0.85 and did not significantly change with lower resolution but decreased with high thresholds, due to loss of trabecular connectivity. Conclusion: When choosing connectivity-preserving thresholds, both micro-CT- and MDCT-based finite-element-models well predicted failure load and still accurately revealed the distribution of local micro-strains in

  3. Prediction of bone strength by μCT and MDCT-based finite-element-models: How much spatial resolution is needed?

    International Nuclear Information System (INIS)

    Bauer, Jan S.; Sidorenko, Irina; Mueller, Dirk; Baum, Thomas; Issever, Ahi Sema; Eckstein, Felix; Rummeny, Ernst J.; Link, Thomas M.; Raeth, Christoph W.

    2014-01-01

    Objectives: Finite-element-models (FEM) are a promising technology to predict bone strength and fracture risk. Usually, the highest spatial resolution technically available is used, but this requires excessive computation time and memory in numerical simulations of large volumes. Thus, FEM were compared at decreasing resolutions with respect to local strain distribution and prediction of failure load to (1) validate MDCT-based FEM and to (2) optimize spatial resolution to save computation time. Materials and methods: 20 cylindrical trabecular bone specimens (diameter 12 mm, length 15–20 mm) were harvested from elderly formalin-fixed human thoracic spines. All specimens were examined by micro-CT (isotropic resolution 30 μm) and whole-body multi-row-detector computed tomography (MDCT, 250 μm × 250 μm × 500 μm). The resolution of all datasets was lowered in eight steps to ∼2000 μm × 2000 μm × 500 μm and FEM were calculated at all resolutions. Failure load was determined by biomechanical testing. Probability density functions of local micro-strains were compared in all datasets and correlations between FEM-based and biomechanically measured failure loads were determined. Results: The distribution of local micro-strains was similar for micro-CT and MDCT at comparable resolutions and showed a shift toward higher average values with decreasing resolution, corresponding to the increasing apparent trabecular thickness. Small micro-strains (ε eff < 0.005) could be calculated down to 250 μm × 250 μm × 500 μm. Biomechanically determined failure load showed significant correlations with all FEM, up to r = 0.85 and did not significantly change with lower resolution but decreased with high thresholds, due to loss of trabecular connectivity. Conclusion: When choosing connectivity-preserving thresholds, both micro-CT- and MDCT-based finite-element-models well predicted failure load and still accurately revealed the distribution of local micro-strains in spatial

  4. Role of Erosion in Shaping Point Bars

    Science.gov (United States)

    Moody, J.; Meade, R.

    2012-04-01

    A powerful metaphor in fluvial geomorphology has been that depositional features such as point bars (and other floodplain features) constitute the river's historical memory in the form of uniformly thick sedimentary deposits waiting for the geomorphologist to dissect and interpret the past. For the past three decades, along the channel of Powder River (Montana USA) we have documented (with annual cross-sectional surveys and pit trenches) the evolution of the shape of three point bars that were created when an extreme flood in 1978 cut new channels across the necks of two former meander bends and radically shifted the location of a third bend. Subsequent erosion has substantially reshaped, at different time scales, the relic sediment deposits of varying age. At the weekly to monthly time scale (i.e., floods from snowmelt or floods from convective or cyclonic storms), the maximum scour depth was computed (by using a numerical model) at locations spaced 1 m apart across the entire point bar for a couple of the largest floods. The maximum predicted scour is about 0.22 m. At the annual time scale, repeated cross-section topographic surveys (25 during 32 years) indicate that net annual erosion at a single location can be as great as 0.5 m, and that the net erosion is greater than net deposition during 8, 16, and 32% of the years for the three point bars. On average, the median annual net erosion was 21, 36, and 51% of the net deposition. At the decadal time scale, an index of point bar preservation often referred to as completeness was defined for each cross section as the percentage of the initial deposit (older than 10 years) that was still remaining in 2011; computations indicate that 19, 41, and 36% of the initial deposits of sediment were eroded. Initial deposits were not uniform in thickness and often represented thicker pods of sediment connected by thin layers of sediment or even isolated pods at different elevations across the point bar in response to multiple

  5. Effect of stone coverage on soil erosion

    Science.gov (United States)

    Jomaa, S.; Barry, D. A.; Heng, B. P.; Brovelli, A.; Sander, G. C.; Parlange, J.

    2010-12-01

    Soil surface coverage has a significant impact on water infiltration, runoff and soil erosion yields. In particular, surface stones protect the soils from raindrop detachment, they retard the overland flow therefore decreasing its sediment transport capacity, and they prevent surface sealing. Several physical and environmental factors control to what extent stones on the soil surface modify the erosion rates and the related hydrological response. Among the most important factors are the moisture content of the topsoil, stone size, emplacement, coverage density and soil texture. Owing to the different inter-related processes, there is ambiguity concerning the quantitative effect of stones, and process-based understanding is limited. Experiments were performed (i) to quantify how stone features affect sediment yields, (ii) to understand the local effect of isolated surface stones, that is, the changes of the soil particle size distribution in the vicinity of a stone and (iii) to determine how stones attenuate the development of surface sealing and in turn how this affects the local infiltration rate. A series of experiments using the EPFL 6-m × 2-m erosion flume were conducted at different rainfall intensities (28 and 74 mm h-1) and stone coverage (20 and 40%). The total sediment concentration, the concentration of the individual size classes and the flow discharge were measured. In order to analyze the measurements, the Hairsine and Rose (HR) erosion model was adapted to account for the shielding effect of the stone cover. This was done by suitably adjusting the parameters based on the area not covered by stones. It was found that the modified HR model predictions agreed well with the measured sediment concentrations especially for the long time behavior. Changes in the bulk density of the topsoil due to raindrop-induced compaction with and without stone protection revealed that the stones protect the upper soil surface against the structural seals resulting in

  6. Seasonal variation and climate change impact in Rainfall Erosivity across Europe

    Science.gov (United States)

    Panagos, Panos; Borrelli, Pasquale; Meusburger, Katrin; Alewell, Christine; Ballabio, Cristiano

    2017-04-01

    residues, reduced tillage) in regions with high erosivity. Besides soil erosion mapping, the intra-annual analysis of rainfall erosivity is an important step towards flood prevention, hazard mitigation, ecosystem services, land use change and agricultural production. The application of REDES in combination with moderate climate change scenarios scenario (HadGEM RCP 4.5) resulted in predictions of erosivity in 2050. The overall increase of rainfall erosivity in Europe by 18% until 2050 are in line with projected increases of 17% for the U.S.A. The predicted mean rise of erosivity is also expected to increase the threat of soil erosion in Europe. The most noticeable increase of erosivity is projected for North-Central Europe, the English Channel, The Netherlands and Northern France. On the contrary, the Mediterranean basin show mixed trends. The success story with the compilation of REDES and first rainfall erosivity map of Europe was a driver to implement a Global Rainfall Erosivity Database (GloREDa). During the last 3 years, JRC was leading an effort to collect high temporal resolution rainfall data worldwide. In collaboration with 50 scientists worldwide and 100+ Meteorological and environmental Organisations, we have developed a Global Erosivity Database. In this database, we managed to include calculated erosivity values for 3,625 stations covering 63 countries worldwide.

  7. Soil erosion assessment on hillslope of GCE using RUSLE model

    Indian Academy of Sciences (India)

    61

    based on the RUSLE model in the Geographical Information System (GIS) platform. ... process of soil erosion happens in two stages; the first stage involves the ..... deep or surface cover of undecayed residue; c) appreciable brush of 2 m height ..... Kanungo D and Sharma S 2014 Rainfall thresholds for prediction of shallow ...

  8. Mechanics of interrill erosion with wind-driven rain

    Science.gov (United States)

    The vector physics of wind-driven rain (WDR) differs from that of wind-free rain, and the interrill soil detachment equations in the Water Erosion Prediction Project (WEPP) model were not originally developed to deal with this phenomenon. This article provides an evaluation of the performance of the...

  9. Mechanics of Interrill Erosion with Wind-Driven Rain (WDR)

    Science.gov (United States)

    This article provides an evaluation analysis for the performance of the interrill component of the Water Erosion Prediction Project (WEPP) model for Wind-Driven Rain (WDR) events. The interrill delivery rates (Di) were collected in the wind tunnel rainfall simulator facility of the International Cen...

  10. The Future Role of Information Technology in Erosion Modelling

    Science.gov (United States)

    Natural resources management and decision-making is a complex process requiring cooperation and communication among federal, state, and local stakeholders balancing biophysical and socio-economic concerns. Predicting soil erosion is common practice in natural resource management for assessing the e...

  11. Predicción de la erosión eólica potencial con el modelo EWEQ en dos suelos loesicos: efectos de las condiciones climáticas Wind erosion prediction with the EWEQ model in two loess soils: effects of climatic condition

    Directory of Open Access Journals (Sweden)

    Silvia Beatriz Aimar

    2011-12-01

    Full Text Available La erosión eólica potencial del suelo (EEP es un dato básico utilizado en varios modelos de predicción para calcular la erosión eólica de suelos agrícolas. El objetivo de este estudio fue cuantificar la EEP de un Haplustol y un Ustipsammente de la Región Semiárida Pampeana (RSP y compararla con las predicciones del modelo Ecuación de Erosión Eólica en Español (EWEQ, realizadas con diferentes factores climáticos (C. Se efectuaron mediciones de EEP a campo durante un año en ambos suelos, mantenidos sin cobertura y con mínima rugosidad. Los resultados indicaron que la EEP medida a campo fue mayor en el Ustipsammente (270 Mg ha-1 año-1 que en el Haplustol (40 Mg ha-1 año -1 , con una reducción en el espesor del horizonte de 21,3 y 3,1 mm, respectivamente. La erosión del Ustipsammente fue dos veces mayor en primavera-verano que en otoño-invierno. Este efecto no se observó en el Haplustol, debido a su menor desecamiento y mayores contenidos de humedad luego de las lluvias. La erosión del Haplustol, por desecarse más lentamente luego de una lluvia, fue más condicionada por las precipitaciones que la del Ustipsammente. Un 40% de la erosión de ambos suelos fue definida por la duración de las tormentas. Las tasas de erosión (EEP por unidad de tiempo, Qt se correlacionaron positivamente con la velocidad promedio del viento (V, ajustando a una función polinómica en ambos suelos. A la misma V, Qt fue siempre mayor en el Ustipsammente. La EEP calculada con la EWEQ, utilizando el factor C correspondiente al año de muestreo (30,3, fue la más semejante a la erosión medida a campo, aunque el modelo la subestimó en un 43% en el Haplustol y en un 18% en el Ustipsammente. La EWEQ deberá ofrecer al usuario distintos factores C para poder predecir EEP en escenarios climáticos variables.The potential wind erosion of a soil (EEP is a basic data for predicting wind erosion of agricultural soils in most wind erosion prediction models

  12. Effect of hard second-phase particles on the erosion resistance of model alloys

    International Nuclear Information System (INIS)

    Kosel, T.H.; Aptekar, S.S.

    1986-01-01

    The dependence of erosion rate on second phase volume fraction (SPVF) has been studied for Cu/Al/sub 2/O/sub 3/ and Cu/WC(W/sub 2/C) model alloys produced by pressing and sintering. The intention was to investigate the reasons for the poor contribution to erosion resistance made by large hard second phase particles (SPP) in other studies. The results show that for Cu/Al/sub 2/O/sub 3/ alloys, the erosion rate generally increased with SPVF, demonstrating a negative contribution to erosion resistance. This occurred despite the fact that the measured erosion rate of monolithic Al/sub 2/O/sub 3/ was lower by one to two orders of magnitude than that of the pure matrix. Changing from severe erosion with large erodent particles at high velocity to mild conditions with small erodent at low velocity caused a change from depression of the SPPs to protrusion from the surface, with some improvement of the relative erosion resistance compared to the pure matrix. For Cu/WC(W/sub 2/C) alloys, changing from severe to mild erosion conditions caused a change from an increase of erosion with SPVF to a decrease. The results are discussed in terms of the increased microfracture of the unsupported edges of the second phase particles compared to a flat single-phase surface. This edge is consistent with the results, and explains observations not predicted by existing theories for erosion of single-phase materials. A model is introduced which predicts a new averaging law for the erosion rate of a two-phase alloy in terms of erosion rates of its constituent phases

  13. Viewpoint: Sustainability of piñon-juniper ecosystems - A unifying perspective of soil erosion thresholds

    Science.gov (United States)

    Davenport, David W.; Breshears, D.D.; Wilcox, B.P.; Allen, Craig D.

    1998-01-01

    Many pinon-juniper ecosystem in the western U.S. are subject to accelerated erosion while others are undergoing little or no erosion. Controversy has developed over whether invading or encroaching pinon and juniper species are inherently harmful to rangeland ecosystems. We developed a conceptual model of soil erosion in pinon-jumper ecosystems that is consistent with both sides of the controversy and suggests that the diverse perspectives on this issue arise from threshold effects operating under very different site conditions. Soil erosion rate can be viewed as a function of (1) site erosion potential (SEP), determined by climate, geomorphology and soil erodibility; and (2) ground cover. Site erosion potential and cove act synergistically to determine soil erosion rates, as evident even from simple USLE predictions of erosion. In pinon-juniper ecosystem with high SEP, the erosion rate is highly sensitive to ground cover and can cross a threshold so that erosion increases dramatically in response to a small decrease in cover. The sensitivity of erosion rate to SEP and cover can be visualized as a cusp catastrophe surface on which changes may occur rapidly and irreversibly. The mechanisms associated with a rapid shift from low to high erosion rate can be illustrated using percolation theory to incorporate spatial, temporal, and scale-dependent patterns of water storage capacity on a hillslope. Percolation theory demonstrates how hillslope runoff can undergo a threshold response to a minor change in storage capacity. Our conceptual model suggests that pinion and juniper contribute to accelerated erosion only under a limited range of site conditions which, however, may exist over large areas.

  14. Auto consolidated cohesive sediments erosion

    International Nuclear Information System (INIS)

    Ternat, F.

    2007-02-01

    Pollutants and suspended matters of a river can accumulate into the sedimentary column. Once deposited, they are submitted to self-weight consolidation processes, ageing and burying, leading to an increase of their erosion resistance. Pollutant fluxes can be related to sedimentary fluxes, determined by threshold laws. In this work, an erosion threshold model is suggested by introducing a cohesion force into the usual force balance. A model of cohesion is developed on the basis of interactions between argillaceous cohesive particles (clays), particularly the Van der Waals force, whose parameterization is ensured by means of granulometry and porosity. Artificial erosion experiments were performed in a recirculating erosion flume with natural cored sediments where critical shear stress measurements were performed. Other analyses provided granulometry and porosity. The results obtained constitute a good database for the literature. The model is then applied to the experimental conditions and gives good agreement with measurements. An example of the accounting for self-weight consolidation processes is finally suggested, before finishing on a Mohr like diagram dedicated to soft cohesive sediment erosion. (author)

  15. Advancements in Hydrology and Erosion Process Understanding and Post-Fire Hydrologic and Erosion Model Development for Semi-Arid Landscapes

    Science.gov (United States)

    Williams, C. Jason; Pierson, Frederick B.; Al-Hamdan, Osama Z.; Robichaud, Peter R.; Nearing, Mark A.; Hernandez, Mariano; Weltz, Mark A.; Spaeth, Kenneth E.; Goodrich, David C.

    2017-04-01

    Fire activity continues to increase in semi-arid regions around the globe. Private and governmental land management entities are challenged with predicting and mitigating post-fire hydrologic and erosion responses on these landscapes. For more than a decade, a team of scientists with the US Department of Agriculture has collaborated on extensive post-fire hydrologic field research and the application of field research to development of post-fire hydrology and erosion predictive technologies. Experiments funded through this research investigated the impacts of fire on vegetation and soils and the effects of these fire-induced changes on infiltration, runoff generation, erodibility, and soil erosion processes. The distribution of study sites spans diverse topography across grassland, shrubland, and woodland landscapes throughout the western United States. Knowledge gleaned from the extensive field experiments was applied to develop and enhance physically-based models for hillslope- to watershed-scale runoff and erosion prediction. Our field research and subsequent data syntheses have identified key knowledge gaps and challenges regarding post-fire hydrology and erosion modeling. Our presentation details some consistent trends across a diverse domain and varying landscape conditions based on our extensive field campaigns. We demonstrate how field data have advanced our understanding of post-fire hydrology and erosion for semi-arid landscapes and highlight remaining key knowledge gaps. Lastly, we briefly show how our well-replicated experimental methodologies have contributed to advancements in hydrologic and erosion model development for the post-fire environment.

  16. Bentonite erosion. Laboratory studies

    Energy Technology Data Exchange (ETDEWEB)

    Jansson, Mats (Div. of Nuclear Chemistry, Royal Inst. of Technology, Stockholm (Sweden), School of Chemical Science and Engineering)

    2009-11-15

    This report covers the laboratory studies that have been performed at Nuclear Chemistry, KTH in the project 'Bentonite Erosion'. Many of the experiments in this report were performed to support the work of the modelling group and were often relatively simple. One of the experiment series was performed to see the impact of gravity and concentration of mono- and di-valent cations. A clay suspension was prepared in a test tube. A net was placed in contact with the suspension, the test tube was filled with solutions of different concentrations and the system was left overnight to settle. The tube was then turned upside down and the behaviour was visually observed. Either the clay suspension fell through the net or stayed on top. By using this method surprisingly sharp determinations of the Critical Coagulation (Flocculation) Concentration (CCC/CFC) could be made. The CCC/CFC of Ca2+ was for sodium montmorillonite determined to be between 1 and 2 mM. An artificial fracture was manufactured in order to simulate the real case scenario. The set-up was two Plexiglas slabs separated by 1 mm thick spacers with a bentonite container at one side of the fracture. Water was pumped with a very low flow rate perpendicular to bentonite container and the water exiting the fracture was sampled and analyzed for colloid content. The bentonite used was treated in different ways. In the first experiment a relatively montmorillonite rich clay was used while in the second bentonite where only the readily soluble minerals had been removed was used. Since Plexiglas was used it was possible to visually observe the bentonite dispersing into the fracture. After the compacted bentonite (1,000 kg/m3) had been water saturated the clay had expanded some 12 mm out into the fracture. As the experiment progressed the clay expanded more out into the fracture and seemed to fractionate in two different phases with less material in the outmost phase. A dark rim which was later analyzed to contain

  17. Bentonite erosion - Laboratory studies

    International Nuclear Information System (INIS)

    Jansson, Mats

    2010-01-01

    Document available in extended abstract form only. Bentonite clay is proposed as buffer material in the KBS-3 concept of storing spent nuclear fuel. Since the clay is plastic it will protect the canisters containing the spent fuel from movements in the rock. Furthermore, the clay will expand when taking up water, become very compact and hence limit the transport of solutes to and from the canister to only diffusion. The chemical stability of the bentonite barrier is of vital importance. If much material would be lost the barrier will lose its functions. As a side effect, lots of colloids will be released which may facilitate radionuclide transport in case of a breach in the canister. There are scenarios where during an ice age fresh melt water may penetrate down to repository depths with relatively high flow rates and not mix with older waters of high salinity. Under such conditions bentonite colloids will be more stable and there is a possibility that the bentonite buffer would start to disperse and bentonite colloids be carried away by the passing water. This work is a part of a larger project called Bentonite Erosion, initiated and supported by SKB. In this work several minor experiments have been performed in order to investigate the influence of for instance di-valent cations, gravity, etc. on the dispersion behaviour of bentonite and/or montmorillonite. A bigger experiment where the real situation was simulated using an artificial fracture was conducted. Two Plexiglas slabs were placed on top of each other, separated by plastic spacers. Bentonite was placed in a container in contact with a fracture. The bentonite was water saturated before deionized water was pumped through the fracture. The evolution of the bentonite profile in the fracture was followed visually. The eluate was collected in five different slots at the outlet side and analyzed for colloid concentration employing Photon Correlation Spectroscopy (PCS) and a Single Particle Counter (SPC). Some

  18. Plume Mitigation: Soil Erosion and Lunar Prospecting Sensor Project

    Science.gov (United States)

    Metzger, Philip T.

    2014-01-01

    Demonstrate feasibility of the simplest, lowest-mass method of measuring density of a cloud of lunar soil ejected by rocket exhaust, using new math techniques with a small baseline laser/camera system. Focus is on exploring the erosion process that occurs when the exhaust plume of a lunar rocket impacts the regolith. Also, predicting the behavior of the lunar soil that would be blasted from a lunar landing/launch site shall assist in better design and protection of any future lunar settlement from scouring of structures and equipment. NASA is gathering experimental data to improve soil erosion models and understand how lunar particles enter the plume flow.

  19. Transcutaneous Raman Spectroscopy of Bone

    Science.gov (United States)

    Maher, Jason R.

    Clinical diagnoses of bone health and fracture risk typically rely upon measurements of bone density or structure, but the strength of a bone is also dependent upon its chemical composition. One technology that has been used extensively in ex vivo, exposed-bone studies to measure the chemical composition of bone is Raman spectroscopy. This spectroscopic technique provides chemical information about a sample by probing its molecular vibrations. In the case of bone tissue, Raman spectra provide chemical information about both the inorganic mineral and organic matrix components, which each contribute to bone strength. To explore the relationship between bone strength and chemical composition, our laboratory has contributed to ex vivo, exposed-bone animal studies of rheumatoid arthritis, glucocorticoid-induced osteoporosis, and prolonged lead exposure. All of these studies suggest that Raman-based predictions of biomechanical strength may be more accurate than those produced by the clinically-used parameter of bone mineral density. The utility of Raman spectroscopy in ex vivo, exposed-bone studies has inspired attempts to perform bone spectroscopy transcutaneously. Although the results are promising, further advancements are necessary to make non-invasive, in vivo measurements of bone that are of sufficient quality to generate accurate predictions of fracture risk. In order to separate the signals from bone and soft tissue that contribute to a transcutaneous measurement, we developed an overconstrained extraction algorithm that is based upon fitting with spectral libraries derived from separately-acquired measurements of the underlying tissue components. This approach allows for accurate spectral unmixing despite the fact that similar chemical components (e.g., type I collagen) are present in both soft tissue and bone and was applied to experimental data in order to transcutaneously detect, to our knowledge for the first time, age- and disease-related spectral

  20. Determining long-term regional erosion rates using impact craters

    Science.gov (United States)

    Hergarten, Stefan; Kenkmann, Thomas

    2015-04-01

    More than 300,000 impact craters have been found on Mars, while the surface of Moon's highlands is even saturated with craters. In contrast, only 184 impact craters have been confirmed on Earth so far with only 125 of them exposed at the surface. The spatial distribution of these impact craters is highly inhomogeneous. Beside the large variation in the age of the crust, consumption of craters by erosion and burial by sediments are the main actors being responsible for the quite small and inhomogeneous crater record. In this study we present a novel approach to infer long-term average erosion rates at regional scales from the terrestrial crater inventory. The basic idea behind this approach is a dynamic equilibrium between the production of new craters and their consumption by erosion. It is assumed that each crater remains detectable until the total erosion after the impact exceeds a characteristic depth depending on the crater's diameter. Combining this model with the terrestrial crater production rate, i.e., the number of craters per unit area and time as a function of their diameter, allows for a prediction of the expected number of craters in a given region as a function of the erosion rate. Using the real crater inventory, this relationship can be inverted to determine the regional long-term erosion rate and its statistical uncertainty. A limitation by the finite age of the crust can also be taken into account. Applying the method to the Colorado Plateau and the Deccan Traps, both being regions with a distinct geological history, yields erosion rates in excellent agreement with those obtained by other, more laborious methods. However, these rates are formally exposed to large statistical uncertainties due to the small number of impact craters. As higher crater densities are related to lower erosion rates, smaller statistical errors can be expected when large regions in old parts of the crust are considered. Very low long-term erosion rates of less than 4

  1. Soil erosion in Slovene Istria

    Directory of Open Access Journals (Sweden)

    Matjaž Mikoš

    2009-12-01

    Full Text Available From the end of nineties of the 20th century, intense hydrologic and geomorphologic research is taking place in the Slovene Istria. As a part of this research also studies on soil erosion were undertaken in the period from 2005 to 2008. The field measurements were under taken onclosed 1m2 large erosion plots under three different land uses (on bare soils in an olive grove, on an overgrown meadow, in a forest, placed south of the Marezige village in the Rokava River basin.We show weekly measurements of surface erosion (interrill erosion for the period of 13 months (the end of March 2005 – the end of April 2006, as well as monthly and seasonal averages together with selected linear statistical correlations between soil erosion and weather parameters.From May 2005 to April 2006 the interrill erosion on bare soils in an olive grove with an inclination of 5.5° amounted to 9013 g/m2 (90 t/ha that corresponds to surface lowering rate of 8.5 mm/yr; on an overgrown meadow with an inclination of 9.4° it amounted to 168 g/m2 (1,68 t/ha that corresponds to surface lowering rate of 0.16 mm//yr; and in a forest with an inclination of 7.8° it amounted to 391 g/m2 (3,91 t/ha and in a forest with an inclination of 21.4° it amounted to 415 g/m2 (4,15 t/ha, respectively, that corresponds to surface lowering rate of 0.4 mm/yr.

  2. Estimativa da produção de sedimentos mediante uso de um modelo hidrossedimentológico acoplado a um SIG Sediment yield prediction through the use of a runoff-erosion model coupled to a GIS

    Directory of Open Access Journals (Sweden)

    Richarde M. da Silva

    2008-10-01

    Full Text Available O Kineros é um modelo hidrossedimentológico usado para se estimar a vazão e a produção de sedimentos em bacias urbanas e rurais. No presente trabalho, o modelo foi aplicado à bacia do rio Pirapama, localizada na zona litorânea do Estado de Pernambuco, cujos resultados foram acoplados a um SIG com o objetivo de identificar, temporal e espacialmente, os principais locais em que o processo de erosão foi mais atuante na bacia do rio Pirapama. O modelo foi calibrado com dados diários de 1990 a 2001 de dois postos pluviométricos. Através do acoplamento dos resultados da modelagem no SIG, foi possível a identificação das principais áreas susceptíveis ao processo erosivo. Os resultados da produção de sedimentos na bacia mostraram que os planos com maior produção produziram mais de 200 t ha-1 ano-1, perfazendo o total de 653.079 t, correspondentes a uma área de 67,87 km² (11,3% da área total da bacia revelando, assim, que grande parte da bacia é realmente susceptível ao processo de erosão. Este trabalho mostra que o modelo Kineros é viável para bacias maiores que 100 km² e o seu acoplamento ao SIG é de grande valia para a identificação e análise das principais áreas de produção de sedimentos na bacia deste rio podendo ser, assim, considerado ferramenta promissora para simulação da produção de sedimentos em bacias hidrográficas do nordeste brasileiro.Kineros is a runoff-erosion model used to compute runoff and sediment yield in urban and rural basins. In this paper, the model was applied to the Pirapama river basin, located in the coastal zone of the State of Pernambuco. The obtained results were linked to a GIS in order to temporally and spatially identify the areas susceptible to the erosion process within the Pirapama river basin. The model was calibrated with daily rainfall data from two raingauges for the period from 1990 to 2001. From the coupling of the modeling results into a GIS, it was possible to

  3. Roles of PAD4 and NETosis in Experimental Atherosclerosis and Arterial Injury: Implications for Superficial Erosion.

    Science.gov (United States)

    Franck, Grégory; Mawson, Thomas L; Folco, Eduardo J; Molinaro, Roberto; Ruvkun, Victoria; Engelbertsen, Daniel; Liu, Xin; Tesmenitsky, Yevgenia; Shvartz, Eugenia; Sukhova, Galina K; Michel, Jean-Baptiste; Nicoletti, Antonino; Lichtman, Andrew; Wagner, Denisa; Croce, Kevin J; Libby, Peter

    2018-06-22

    Neutrophils likely contribute to the thrombotic complications of human atheromata. In particular, neutrophil extracellular traps (NETs) could exacerbate local inflammation and amplify and propagate arterial intimal injury and thrombosis. PAD4 (peptidyl arginine deiminase 4) participates in NET formation, but an understanding of this enzyme's role in atherothrombosis remains scant. This study tested the hypothesis that PAD4 and NETs influence experimental atherogenesis and in processes implicated in superficial erosion, a form of plaque complication we previously associated with NETs. Bone marrow chimeric Ldlr deficient mice reconstituted with either wild-type or PAD4-deficient cells underwent studies that assessed atheroma formation or procedures designed to probe mechanisms related to superficial erosion. PAD4 deficiency neither retarded fatty streak formation nor reduced plaque size or inflammation in bone marrow chimeric mice that consumed an atherogenic diet. In contrast, either a PAD4 deficiency in bone marrow-derived cells or administration of DNaseI to disrupt NETs decreased the extent of arterial intimal injury in mice with arterial lesions tailored to recapitulate characteristics of human atheroma complicated by erosion. These results indicate that PAD4 from bone marrow-derived cells and NETs do not influence chronic experimental atherogenesis, but participate causally in acute thrombotic complications of intimal lesions that recapitulate features of superficial erosion. © 2018 American Heart Association, Inc.

  4. Fibrous dysplasia of bone

    International Nuclear Information System (INIS)

    Kim, Kyung Soo; Lee, Sang Wook; Cho, Young Jun; Kim, Young Sook

    1983-01-01

    Fibrous dysplasia of bone is a skeletal development anomaly of unknown etiology characterized by single or multiple areas of fibrous tissue replacement of medullary cavity of one or more bones. The disease may be localized to single bone (monostotic form) or may affect multiple bones (polyostotic form). Eighteen cases of fibrous dysplasia diagnosed by roentgenlogic or histologic assessment at Chosun University Hospital, Chosun University Hospital and Kwangju Christian Hospital during recent ten tears were analyzed clinically and radiologically. The results were as follows: 1. 16 case of them had monostotic involvement, and 2 cases showed polyostotic disease, but none of our series presented Albright's syndrome. 2. The male to female ratio in this series was 10 : 8, but then 2 polyostotic forms of them were females. In age distribution, peak incidence at the time of diagnosis was in the age group of second decade (10 cases). 3. Maxilla (6 cases) and femur (4 case) were frequently involved sites in patients with monostotic lesion, whereas polyostotic lesions diffusely affected skull, pelvis, ribs and limb bones. 4. The clinical symptoms according to the extent and site of disease were very variable, which were localized painless or painful swelling, nasal obstruction, deformity of face or extremity and incidentally during routine roentgen study. 5. The chemical abnormality of blood serum was moderate degree of elevated serum alkaline phosphatase in only one patients with monostotic lesion. 6. The main radiologic findings of fibrous dysplasia were relatively well circumscribed single or multiloculated cystilike appearance, bone expansion, cortical thinning and/or erosion, bony deformity and pathologic fracture, but especially in maxilla, dense homogenous area with expanding lesion was observed in our series

  5. Biochemical markers of bone turnover

    International Nuclear Information System (INIS)

    Kim, Deog Yoon

    1999-01-01

    Biochemical markers of bone turnover has received increasing attention over the past few years, because of the need for sensitivity and specific tool in the clinical investigation of osteoporosis. Bone markers should be unique to bone, reflect changes of bone less, and should be correlated with radiocalcium kinetics, histomorphometry, or changes in bone mass. The markers also should be useful in monitoring treatment efficacy. Although no bone marker has been established to meet all these criteria, currently osteocalcin and pyridinium crosslinks are the most efficient markers to assess the level of bone turnover in the menopausal and senile osteoporosis. Recently, N-terminal telopeptide (NTX), C-terminal telopeptide (CTX) and bone specific alkaline phosphatase are considered as new valid markers of bone turnover. Recent data suggest that CTX and free deoxypyridinoline could predict the subsequent risk of hip fracture of elderly women. Treatment of postmenopausal women with estrogen, calcitonin and bisphosphonates demonstrated rapid decrease of the levels of bone markers that correlated with the long-term increase of bone mass. Factors such as circadian rhythms, diet, age, sex, bone mass and renal function affect the results of biochemical markers and should be appropriately adjusted whenever possible. Each biochemical markers of bone turnover may have its own specific advantages and limitations. Recent advances in research will provide more sensitive and specific assays

  6. Uncertainty in soil carbon accounting due to unrecognized soil erosion.

    Science.gov (United States)

    Sanderman, Jonathan; Chappell, Adrian

    2013-01-01

    The movement of soil organic carbon (SOC) during erosion and deposition events represents a major perturbation to the terrestrial carbon cycle. Despite the recognized impact soil redistribution can have on the carbon cycle, few major carbon accounting models currently allow for soil mass flux. Here, we modified a commonly used SOC model to include a soil redistribution term and then applied it to scenarios which explore the implications of unrecognized erosion and deposition for SOC accounting. We show that models that assume a static landscape may be calibrated incorrectly as erosion of SOC is hidden within the decay constants. This implicit inclusion of erosion then limits the predictive capacity of these models when applied to sites with different soil redistribution histories. Decay constants were found to be 15-50% slower when an erosion rate of 15 t soil ha(-1)  yr(-1) was explicitly included in the SOC model calibration. Static models cannot account for SOC change resulting from agricultural management practices focused on reducing erosion rates. Without accounting for soil redistribution, a soil sampling scheme which uses a fixed depth to support model development can create large errors in actual and relative changes in SOC stocks. When modest levels of erosion were ignored, the combined uncertainty in carbon sequestration rates was 0.3-1.0 t CO2  ha(-1)  yr(-1) . This range is similar to expected sequestration rates for many management options aimed at increasing SOC levels. It is evident from these analyses that explicit recognition of soil redistribution is critical to the success of a carbon monitoring or trading scheme which seeks to credit agricultural activities. © 2012 Blackwell Publishing Ltd.

  7. Modelling soil erosion at European scale: towards harmonization and reproducibility

    Science.gov (United States)

    Bosco, C.; de Rigo, D.; Dewitte, O.; Poesen, J.; Panagos, P.

    2015-02-01

    Soil erosion by water is one of the most widespread forms of soil degradation. The loss of soil as a result of erosion can lead to decline in organic matter and nutrient contents, breakdown of soil structure and reduction of the water-holding capacity. Measuring soil loss across the whole landscape is impractical and thus research is needed to improve methods of estimating soil erosion with computational modelling, upon which integrated assessment and mitigation strategies may be based. Despite the efforts, the prediction value of existing models is still limited, especially at regional and continental scale, because a systematic knowledge of local climatological and soil parameters is often unavailable. A new approach for modelling soil erosion at regional scale is here proposed. It is based on the joint use of low-data-demanding models and innovative techniques for better estimating model inputs. The proposed modelling architecture has at its basis the semantic array programming paradigm and a strong effort towards computational reproducibility. An extended version of the Revised Universal Soil Loss Equation (RUSLE) has been implemented merging different empirical rainfall-erosivity equations within a climatic ensemble model and adding a new factor for a better consideration of soil stoniness within the model. Pan-European soil erosion rates by water have been estimated through the use of publicly available data sets and locally reliable empirical relationships. The accuracy of the results is corroborated by a visual plausibility check (63% of a random sample of grid cells are accurate, 83% at least moderately accurate, bootstrap p ≤ 0.05). A comparison with country-level statistics of pre-existing European soil erosion maps is also provided.

  8. EFFECTS OF SLOPE SHAPES ON SOIL EROSION

    Directory of Open Access Journals (Sweden)

    Hüseyin ŞENSOY, Şahin PALTA

    2009-01-01

    Full Text Available Water is one of the most important erosive forces. A great number of factors also play a role in erosion process and slope characteristic is also one of them. The steepness and length of the slope are important factors for runoff and soil erosion. Another slope factor that has an effect on erosion is the shape of the slope. Generally, different erosion and runoff characteristics exist in different slopes which can be classified as uniform, concave, convex and complex shape. In this study, the effects of slope shape on erosion are stated and emphasized by taking similar researches into consideration.

  9. Bone marrow aspiration

    Science.gov (United States)

    Iliac crest tap; Sternal tap; Leukemia - bone marrow aspiration; Aplastic anemia - bone marrow aspiration; Myelodysplastic syndrome - bone marrow aspiration; Thrombocytopenia - bone marrow aspiration; Myelofibrosis - bone marrow aspiration

  10. Water Erosion Prediction Using the Revised Universal Soil Loss Equation (RUSLE in a GIS Framework, Central Chile Estimación de la Erosión Hídrica Empleando la Ecuación Universal de Pérdida de Suelo Revisada (RUSLE y SIG en Chile Central

    Directory of Open Access Journals (Sweden)

    Carlos A Bonilla

    2010-03-01

    Full Text Available Soil erosion is a growing problem in Central Chile, particularly in coastal dry lands, where it can significantly decrease the productivity of rainfed agriculture and forestry. In this study, the Revised Universal Soil Loss Equation (RUSLE was integrated into a Geographic Information System (GIS, and used to evaluate the effects of different combinations of vegetative cover on soil erosion rates for Santo Domingo County in Central Chile. Implementing RUSLE in the GIS required a complete description of the county’s soils, climate, topography and current land use/land cover. This information was compiled in rasters of 25 x 25 m cells. RUSLE parameter values were assigned to each cell and annual soil loss estimates were generated on a cell by cell basis. Soil losses were estimated for the current and for three alternate scenarios of vegetative cover. Under current conditions, 39.7% of the county is predicted to have low erosion rates ( 1.1 t ha-1 yr-1. The remainder of the surface (10.2% is not subject to erosion. Under the recommended alternate scenario, 89.3% of the county is predicted to have low erosion rates, and no areas are affected by high soil loss, reducing soil erosion to a level that will not affect long term productivity. This paper describes how RUSLE was implemented in the GIS, and the methodology and equations used to evaluate the effects of the land use/land cover changes.La erosión hídrica es un problema creciente en la Zona Central de Chile, especialmente en el Secano Costero, donde reduce la productividad de los suelos agrícolas y forestales. En este trabajo se empleó la Ecuación Universal de Pérdida de Suelo Revisada (RUSLE integrada a un Sistema de Información Geográfica (GIS para evaluar el efecto de distintas combinaciones de cubierta vegetal en las tasas de erosión en la comuna de Santo Domingo, Chile. La implementación de RUSLE en el GIS requirió la caracterización de suelos, clima, relieve y uso actual del

  11. CFD simulations of flow erosion and flow-induced deformation of needle valve: Effects of operation, structure and fluid parameters

    Energy Technology Data Exchange (ETDEWEB)

    Zhu, Hongjun, E-mail: ticky863@126.com [State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation, Southwest Petroleum University, Chengdu 610500, Sichuan (China); State Key Laboratory of Hydraulics and Mountain River Engineering, Sichuan University, Chengdu 610065, Sichuan (China); Pan, Qian; Zhang, Wenli; Feng, Guang; Li, Xue [State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation, Southwest Petroleum University, Chengdu 610500, Sichuan (China)

    2014-07-01

    Highlights: • A combined FSI–CFD and DPM computational method is used to investigate flow erosion and deformation of needle valve. • The numerical model is validated with the comparison of measured and predicted erosion rate. • Effects of operation, structure and fluid parameters on flow erosion and flow-induced deformation are discussed. • Particle diameter has the most significant effect on flow erosion. • Inlet rate has the most obvious effect on flow-induced deformation. - Abstract: A three-dimensional fluid–structure interaction (FSI) computational model coupling with a combined continuum and discrete model has been used to predict the flow erosion rate and flow-induced deformation of needle valve. Comparisons with measured data demonstrate good agreement with the predictions of erosion rate. The flow field distribution of gas-particle flow and the erosion rate and deformation of valve core are captured under different operating and structural conditions with different fluid parameters. The effects of inlet velocity, valve opening and inlet valve channel size, particle concentration, particle diameter and particle phase components are discussed in detail. The results indicate that valve tip has the most severe erosion and deformation, and flow field, erosion rate and deformation of valve are all sensitive to inlet condition changes, structural changes and fluid properties changes. The effect of particle diameter on erosion is the most significant, while the influence of inlet rate on deformation is the greatest one.

  12. Water Erosion in Different Slope Lengths on Bare Soil

    Directory of Open Access Journals (Sweden)

    Bárbara Bagio

    Full Text Available ABSTRACT Water erosion degrades the soil and contaminates the environment, and one influential factor on erosion is slope length. The aim of this study was to quantify losses of soil (SL and water (WL in a Humic Cambisol in a field experiment under natural rainfall conditions from July 4, 2014 to June 18, 2015 in individual events of 41 erosive rains in the Southern Plateau of Santa Catarina and to estimate soil losses through the USLE and RUSLE models. The treatments consisted of slope lengths of 11, 22, 33, and 44 m, with an average degree of slope of 8 %, on bare and uncropped soil that had been cultivated with corn prior to the study. At the end of the corn cycle, the stalk residue was removed from the surface, leaving the roots of the crop in the soil. Soil loss by water erosion is related linearly and positively to the increase in slope length in the span between 11 and 44 m. Soil losses were related to water losses and the Erosivity Index (EI30, while water losses were related to rain depth. Soil losses estimated by the USLE and RUSLE model showed lower values than the values observed experimentally in the field, especially the values estimated by the USLE. The values of factor L calculated for slope length of 11, 22, 33, and 44 m for the two versions (USLE and RUSLE of the soil loss prediction model showed satisfactory results in relation to the values of soil losses observed.

  13. Integrated spatial assessment of wind erosion risk in Hungary

    Directory of Open Access Journals (Sweden)

    L. Pásztor

    2016-11-01

    Full Text Available Wind erosion susceptibility of Hungarian soils was mapped on the national level integrating three factors of the complex phenomenon of deflation (physical soil features, wind characteristics, and land use and land cover. Results of wind tunnel experiments on erodibility of representative soil samples were used for the parametrization of a countrywide map of soil texture compiled for the upper 5 cm layer of soil, which resulted in a map representing threshold wind velocity exceedance. Average wind velocity was spatially estimated with 0.5′ resolution using the Meteorological Interpolation based on Surface Homogenised Data Basis (MISH method elaborated for the spatial interpolation of surface meteorological elements. The probability of threshold wind velocity exceedance was determined based on values predicted by the soil texture map at the grid locations. Ratio values were further interpolated to a finer 1 ha resolution using sand and silt content of the uppermost (0–5 cm layer of soil as spatial co-variables. Land cover was also taken into account, excluding areas that are not relevant to wind erosion (forests, water bodies, settlements, etc., to spatially assess the risk of wind erosion. According to the resulting map of wind erosion susceptibility, about 10 % of the total area of Hungary can be identified as susceptible to wind erosion. The map gives more detailed insight into the spatial distribution of wind-affected areas in Hungary compared to previous studies.

  14. A model for hydrolytic degradation and erosion of biodegradable polymers.

    Science.gov (United States)

    Sevim, Kevser; Pan, Jingzhe

    2018-01-15

    For aliphatic polyesters such as PLAs and PGAs, there is a strong interplay between the hydrolytic degradation and erosion - degradation leads to a critically low molecular weight at which erosion starts. This paper considers the underlying physical and chemical processes of hydrolytic degradation and erosion. Several kinetic mechanisms are incorporated into a mathematical model in an attempt to explain different behaviours of mass loss observed in experiments. In the combined model, autocatalytic hydrolysis, oligomer production and their diffusion are considered together with surface and interior erosion using a set of differential equations and Monte Carlo technique. Oligomer and drug diffusion are modelled using Fick's law with the diffusion coefficients dependent on porosity. The porosity is due to the formation of cavities which are a result of polymer erosion. The model can follow mass loss and drug release up to 100%, which cannot be explained using a simple reaction-diffusion. The model is applied to two case studies from the literature to demonstrate its validity. The case studies show that a critical molecular weight for the onset of polymer erosion and an incubation period for the polymer dissolution are two critical factors that need to be considered when predicting mass loss and drug release. In order to design bioresorbable implants, it is important to have a mathematical model to predict polymer degradation and corresponding drug release. However, very different behaviours of polymer degradation have been observed and there is no single model that can capture all these behaviours. For the first time, the model presented in this paper is capable of capture all these observed behaviours by switching on and off different underlying mechanisms. Unlike the existing reaction-diffusion models, the model presented here can follow the degradation and drug release all the way to the full disappearance of an implant. Crown Copyright © 2017. Published by

  15. Macrophage inflammatory protein-1α shows predictive value as a risk marker for subjects and sites vulnerable to bone loss in a longitudinal model of aggressive periodontitis.

    Science.gov (United States)

    Fine, Daniel H; Markowitz, Kenneth; Fairlie, Karen; Tischio-Bereski, Debbie; Ferrandiz, Javier; Godboley, Dipti; Furgang, David; Gunsolley, John; Best, Al

    2014-01-01

    Improved diagnostics remains a fundamental goal of biomedical research. This study was designed to assess cytokine biomarkers that could predict bone loss (BL) in localized aggressive periodontitis. 2,058 adolescents were screened. Two groups of 50 periodontally healthy adolescents were enrolled in the longitudinal study. One group had Aggregatibacter actinomycetemcomitans (Aa), the putative pathogen, while the matched cohort did not. Cytokine levels were assessed in saliva and gingival crevicular fluid (GCF). Participants were sampled, examined, and radiographed every 6 months for 2-3 years. Disease was defined as radiographic evidence of BL. Saliva and GCF was collected at each visit, frozen, and then tested retrospectively after detection of BL. Sixteen subjects with Aa developed BL. Saliva from Aa-positive and Aa-negative healthy subjects was compared to subjects who developed BL. GCF was collected from 16 subjects with BL and from another 38 subjects who remained healthy. GCF from BL sites in the 16 subjects was compared to healthy sites in these same subjects and to healthy sites in subjects who remained healthy. Results showed that cytokines in saliva associated with acute inflammation were elevated in subjects who developed BL (i.e., MIP-1α MIP-1β IL-α, IL-1β and IL-8; p<0.01). MIP-1α was elevated 13-fold, 6 months prior to BL. When MIP-1α levels were set at 40 pg/ml, 98% of healthy sites were below that level (Specificity); whereas, 93% of sites with BL were higher (Sensitivity), with comparable Predictive Values of 98%; p<0.0001; 95% C.I. = 42.5-52.7). MIP-1α consistently showed elevated levels as a biomarker for BL in both saliva and GCF, 6 months prior to BL. MIP-1α continues to demonstrate its strong candidacy as a diagnostic biomarker for both subject and site vulnerability to BL.

  16. Macrophage inflammatory protein-1α shows predictive value as a risk marker for subjects and sites vulnerable to bone loss in a longitudinal model of aggressive periodontitis.

    Directory of Open Access Journals (Sweden)

    Daniel H Fine

    Full Text Available Improved diagnostics remains a fundamental goal of biomedical research. This study was designed to assess cytokine biomarkers that could predict bone loss (BL in localized aggressive periodontitis. 2,058 adolescents were screened. Two groups of 50 periodontally healthy adolescents were enrolled in the longitudinal study. One group had Aggregatibacter actinomycetemcomitans (Aa, the putative pathogen, while the matched cohort did not. Cytokine levels were assessed in saliva and gingival crevicular fluid (GCF. Participants were sampled, examined, and radiographed every 6 months for 2-3 years. Disease was defined as radiographic evidence of BL. Saliva and GCF was collected at each visit, frozen, and then tested retrospectively after detection of BL. Sixteen subjects with Aa developed BL. Saliva from Aa-positive and Aa-negative healthy subjects was compared to subjects who developed BL. GCF was collected from 16 subjects with BL and from another 38 subjects who remained healthy. GCF from BL sites in the 16 subjects was compared to healthy sites in these same subjects and to healthy sites in subjects who remained healthy. Results showed that cytokines in saliva associated with acute inflammation were elevated in subjects who developed BL (i.e., MIP-1α MIP-1β IL-α, IL-1β and IL-8; p<0.01. MIP-1α was elevated 13-fold, 6 months prior to BL. When MIP-1α levels were set at 40 pg/ml, 98% of healthy sites were below that level (Specificity; whereas, 93% of sites with BL were higher (Sensitivity, with comparable Predictive Values of 98%; p<0.0001; 95% C.I. = 42.5-52.7. MIP-1α consistently showed elevated levels as a biomarker for BL in both saliva and GCF, 6 months prior to BL. MIP-1α continues to demonstrate its strong candidacy as a diagnostic biomarker for both subject and site vulnerability to BL.

  17. Low Bone Density

    Science.gov (United States)

    ... Density Exam/Testing › Low Bone Density Low Bone Density Low bone density is when your bone density ... people with normal bone density. Detecting Low Bone Density A bone density test will determine whether you ...

  18. Preliminary results of 137 Cs activity in a soil erosion toposequence in cuenca (castilla la mancha, central spain)

    International Nuclear Information System (INIS)

    Bienes, R.; Alvarez, A.; Jimenez-Ballesta, R.

    2009-01-01

    The soil redistribution due to the conventional tillage practices represents a very severe process of soil erosion and degradation in Mediterranean agricultural lands. The existing methods for soil erosion assessment can be grouped into two main categories: erosion modelling and prediction methods and erosion measurement methods. The use of environmental radionuclides, in particular 1 37 Cs, overcomes many of the limitations associated with traditional approaches and has been shown as an effective way of studying erosion and deposition. Its determination and the study of the characters of soils in a sequence permits know the control of the erosion. The objective of this study was to determine the soil erosion rates using 1 37 Cs activities concentrations in a typical Mediterranean environment; the Chillaron basin (Cuenca, Castilla La Mancha, Spain). (Author) 9 refs.

  19. AERO: A Decision Support Tool for Wind Erosion Assessment in Rangelands and Croplands

    Science.gov (United States)

    Galloza, M.; Webb, N.; Herrick, J.

    2015-12-01

    Wind erosion is a key driver of global land degradation, with on- and off-site impacts on agricultural production, air quality, ecosystem services and climate. Measuring rates of wind erosion and dust emission across land use and land cover types is important for quantifying the impacts and identifying and testing practical management options. This process can be assisted by the application of predictive models, which can be a powerful tool for land management agencies. The Aeolian EROsion (AERO) model, a wind erosion and dust emission model interface provides access by non-expert land managers to a sophisticated wind erosion decision-support tool. AERO incorporates land surface processes and sediment transport equations from existing wind erosion models and was designed for application with available national long-term monitoring datasets (e.g. USDI BLM Assessment, Inventory and Monitoring, USDA NRCS Natural Resources Inventory) and monitoring protocols. Ongoing AERO model calibration and validation are supported by geographically diverse data on wind erosion rates and land surface conditions collected by the new National Wind Erosion Research Network. Here we present the new AERO interface, describe parameterization of the underpinning wind erosion model, and provide a summary of the model applications across agricultural lands and rangelands in the United States.

  20. Assessment of mercury erosion by surface water in Wanshan mercury mining area.

    Science.gov (United States)

    Dai, ZhiHui; Feng, Xinbin; Zhang, Chao; Shang, Lihai; Qiu, Guangle

    2013-08-01

    Soil erosion is a main cause of land degradation, and in its accelerated form is also one of the most serious ecological environmental problems. Moreover, there are few studies on migration of mercury (Hg) induced by soil erosion in seriously Hg-polluted districts. This paper selected Wanshan Hg mining area, SW China as the study area. Revised universal soil loss equation (RUSLE) and Geographic information system (GIS) methods were applied to calculate soil and Hg erosion and to classify soil erosion intensity. Our results show that the soil erosion rate can reach up to 600,884tkm(-2)yr(-1). Surfaces associated with very slight and extremely severe erosion include 76.6% of the entire land in Wanshan. Furthermore, the cumulative erosion rates in the area impacted by extremely severe erosion make up 90.5% of the total. On an annual basis, Hg surface erosion load was predicted to be 505kgyr(-1) and the corresponding mean migration flux of Hg was estimated to be 3.02kgkm(-2)yr(-1). The erosion loads of Hg resulting from farmland and meadow soil were 175 and 319kgyr(-1) respectively, which were enhanced compared to other landscape types due to the fact that they are generally located in the steep zones associated with significant reclamation. Contributing to establish a mass balance of Hg in Wanshan Hg mining area, this study supplies a dependable scientific basis for controlling soil and water erosion in the local ecosystems. Land use change is the most effective way for reducing Hg erosion load in Wanshan mining area. Copyright © 2013 Elsevier Inc. All rights reserved.

  1. Alpha C-telopeptide of type I collagen is associated with subchondral bone turnover and predicts progression of joint space narrowing and osteophytes in osteoarthritis.

    Science.gov (United States)

    Huebner, Janet L; Bay-Jensen, Anne C; Huffman, Kim M; He, Yi; Leeming, Diana J; McDaniel, Gary E; Karsdal, Morten A; Kraus, Virginia B

    2014-09-01

    To evaluate joint tissue remodeling using the urinary collagen biomarkers urinary α-C-telopeptide of type I collagen (α-CTX) and urinary C-telopeptide of type II collagen (CTX-II) and to determine the association of these biomarkers with osteoarthritis (OA) severity, progression, and localized knee bone turnover. Participants (n = 149) with symptomatic and radiographic knee OA underwent fixed-flexion knee radiography at baseline and 3 years, and late-phase bone scintigraphy of both knees at baseline, which were scored semiquantitatively for osteophyte and joint space narrowing (JSN) severity and uptake intensity, with scores summed across knees. Urinary concentrations of α-CTX and CTX-II were determined by enzyme-linked immunosorbent assay. Immunohistochemical analysis of human OA knees was performed to localize the joint tissue origin of the biomarker epitopes. Urinary α-CTX concentrations correlated strongly with the intensity of bone scintigraphic uptake and with JSN progression (risk ratio 13.2) and osteophyte progression (risk ratio 3). Urinary CTX-II concentrations were strongly associated with intensity of bone scintigraphic uptake, with JSN and osteophyte severity, and with OA progression based on osteophyte score. Urinary α-CTX localized primarily to high bone turnover areas in subchondral bone. CTX-II localized to the bone-cartilage interface, the tidemark, and damaged articular cartilage. Baseline urinary α-CTX, which was localized to high turnover areas of subchondral bone, was associated with dynamic bone turnover of knees, as signified by scintigraphy, and progression of both osteophytes and JSN. Urinary CTX-II correlated with JSN and osteophyte severity and progression of osteophytes. To our knowledge, this represents the first report of serologic markers reflecting subchondral bone turnover. These collagen markers may be useful for noninvasive detection and quantification of active subchondral bone turnover and joint remodeling in knee OA

  2. Elevated temperature erosive wear of metallic materials

    International Nuclear Information System (INIS)

    Roy, Manish

    2006-01-01

    Solid particle erosion of metals and alloys at elevated temperature is governed by the nature of the interaction between erosion and oxidation, which, in turn, is determined by the thickness, pliability, morphology, adhesion characteristics and toughness of the oxide scale. The main objective of this paper is to critically review the present state of understanding of the elevated temperature erosion behaviour of metals and alloys. First of all, the erosion testing at elevated temperature is reviewed. This is followed by discussion of the essential features of elevated temperature erosion with special emphasis on microscopic observation, giving details of the erosion-oxidation (E-O) interaction mechanisms. The E-O interaction has been elaborated in the subsequent section. The E-O interaction includes E-O maps, analysis of transition criteria from one erosion mechanism to another mechanism and quantification of enhanced oxidation kinetics during erosion. Finally, the relevant areas for future studies are indicated. (topical review)

  3. Understanding Soil Erosion in Irrigated Agriculture

    OpenAIRE

    O' Schwankl, Lawrence J

    2006-01-01

    A soil's physical and chemical properties determine whether it is vulnerable to erosion, which can reduce soil quality and cause other problems besides. Learn the basics of identifying what type of erosion is affecting your land and what's causing it.

  4. Physical activity effects on bone metabolism.

    Science.gov (United States)

    Smith, E L; Gilligan, C

    1991-01-01

    The incidence of osteoporotic fractures rises exponentially with age and is increasing faster than the demographic increase in the aging population. Physical activity has great potential to reduce the risk for osteoporotic fractures. Three independent but interactive factors contribute to the risk of fractures: bone strength, the risk of falling, and the effectiveness of neuromuscular response that protects the skeleton from injury. Exercise can reduce fracture risk not only by preventing bone loss, but by decreasing the risk of falling and the force of impact by improving strength, flexibility, balance, and reaction time. Extreme inactivity causes rapid bone loss of up to 40%, while athletic activity results in bone hypertrophy of up to 40%. Exercise intervention programs have reduced bone loss or increased bone mass in both men and women of various ages and initial bone status. These benefits have been shown for arm bone mineral content, total body calcium, spine, calcium bone index, tibia, and calcaneus. In both middle-aged and elderly women, physical activity intervention reduced bone loss or increased bone mass. The mechanisms for maintenance of skeletal integrity rely on a cellular response to hormonal and mechanical load stimuli. Studies in animal models show that training affects cellular activity. In osteoporotics, cellular erosion is increased and mineral apposition rate (MAR) decreased compared with normal age-matched controls. In contrast to this, sows trained on a treadmill 20 min per day for 20 weeks had greater active periosteal surface, periosteal MAR, and osteonal MAR than untrained sows.

  5. Resultados da cirurgia de latarjet no tratamento da instabilidade anterior traumática do ombro associada à erosão óssea da cavidade glenoidal - seguimento mínimo de um ano Results from latarjet surgery for treating traumatic anterior shoulder instability associated with bone erosion in the glenoid cavity, after minimum follow-up of one year

    Directory of Open Access Journals (Sweden)

    Roberto Yukio Ikemoto

    2011-10-01

    Full Text Available OBJETIVO: Avaliar o resultado da cirurgia de Latarjet para pacientes com luxação recidivante anterior do ombro com perda óssea maior que 25% da cavidade glenoidal. MÉTODO: Avaliamos 26 pacientes submetidos à cirurgia de Latarjet. O tempo médio de seguimento foi de 38 meses e a média etária, de 28 anos. Os pacientes foram avaliados quanto à amplitude de movimento e pelas escalas de Rowe e UCLA, no período pré-operatório como no período pós-operatório, radiografias do ombro para avaliar a presença de artrose, posição e consolidação do enxerto e posicionamento dos parafusos. A análise estatística foi utilizada para avaliar se haveria relação entre o número de episódios de luxação, presença de artrose, correlação entre artrose e limitação da rotação lateral. Comparar a diferença entre o arco de movimento do lado operado com o não acometido e avaliação funcional pré e pós-operatória das escalas de UCLA e Rowe. RESULTADOS: A elevação e rotação lateral foram estatisticamente inferiores do lado operado. A escala de UCLA e a de Rowe mostrou uma melhora estatisticamente significante dos resultados clínico-funcionais (P OBJECTIVE: Evaluate the results from the Latarjet procedure in patients with anterior recurrent dislocation of the shoulder who present bone loss of the glenoid cavity greater than 25%. METHODS: Twenty six male patients underwent the Latarjet procedure, The bone loss was evaluated by means of radiography using the Bernageau view and by means of CAT scan. The patients were evaluated with regard to range of motion, using the Rowe and UCLA scales, before and after the operation, and by radiographs to assess the presence of arthrosis, position and consolidation of the graft and positioning of the screws. Statistical analysis was used to assess whether there was any relationship between the number of episodes of dislocation and the presence of arthrosis, , and any relationship between arthrosis and

  6. Erosion of the first wall of Tokamaks

    International Nuclear Information System (INIS)

    Guseva, M.I.; Ionova, E.S.; Martynenko, Yu.V.

    1980-01-01

    An estimate of the rate of erosion of the wall due to sputtering and blistering requires knowledge of the fluxes and energies of the particles which go from the plasma to the wall, of the sputtering coefficients S, and of the erosion coefficients S* for blistering. The overall erosion coefficient is equal to the sum of the sputtering coefficient and the erosion coefficient for blistering. Here the T-20 Tokamak is examined as an example of a large-scale Tokamak. 18 refs

  7. Soil Erosion. LC Science Tracer Bullet.

    Science.gov (United States)

    Buydos, John F., Comp.

    Soil erosion is the detachment and movement of topsoil or soil material from the upper part of the soil profile. It may occur in the form of rill, gully, sheet, or wind erosion. Agents of erosion may be water, wind, glacial ice, agricultural implements, machinery, and animals. Soil conservation measures require a thorough understanding of the…

  8. Natural and anthropogenic rates of soil erosion

    Science.gov (United States)

    Regions of land that are brought into crop production from native vegetation typically undergo a period of soil erosion instability, and long term erosion rates are greater than for natural lands as long as the land continues being used for crop production. Average rates of soil erosion under natur...

  9. Soil erosion in humid regions: a review

    Science.gov (United States)

    Daniel J. Holz; Karl W.J. Williard; Pamela J. Edwards; Jon E. Schoonover

    2015-01-01

    Soil erosion has significant implications for land productivity and surface water quality, as sediment is the leading water pollutant worldwide. Here, erosion processes are defined. The dominant factors influencing soil erosion in humid areas are reviewed, with an emphasis on the roles of precipitation, soil moisture, soil porosity, slope steepness and length,...

  10. Bone tumors

    International Nuclear Information System (INIS)

    Moylan, D.J.; Yelovich, R.M.

    1991-01-01

    Primary bone malignancies are relatively rare with less than 4,000 new cases per year. Multiple myeloma (more correctly a hematologic malignancy) accounts for 40%; osteosarcomas, 28%; chondrosarcomas, 13%; fibrosarcomas arising in bone, 4%; and Ewing's sarcoma, 7%. The authors discuss various treatments for bone tumors, including radiotherapy, chemotherapy and surgery

  11. Soil Erosion Risk Assessment in Uganda

    Directory of Open Access Journals (Sweden)

    Fidele Karamage

    2017-02-01

    Full Text Available Land use without adequate soil erosion control measures is continuously increasing the risk of soil erosion by water mainly in developing tropical countries. These countries are prone to environmental disturbance due to high population growth and high rainfall intensity. The aim of this study is to assess the state of soil erosion by water in Uganda at national and district levels, for various land cover and land use (LCLU types, in protected areas as well to predict the impact of support practices on soil loss reduction. Predictions obtained using the Revised Universal Soil Loss Equation (RUSLE model indicated that the mean rate of soil loss risk in Uganda’s erosion‐prone lands was 3.2 t∙ha−1∙y−1, resulting in a total annual soil loss of about 62 million tons in 2014. About 39% of the country’s erosion‐prone lands were comprised of unsustainable mean soil loss rates >1 t∙ha−1∙y−1. Out of 112 districts in Uganda, 66 districts were found to have unsustainable estimated soil loss rates >1 t∙ha−1∙y−1. Six districts in Uganda were found to have mean annual soil loss rates of >10 t∙ha−1∙y−1: Bududa (46.3 t∙ha−1∙y−1, Kasese (37.5 t∙ha−1∙y−1, Bundibugyo (28.9 t∙ha−1∙y−1, Bulambuli (20.9 t∙ha−1∙y−1, Sironko (14.6 t∙ha−1∙y−1 and Kotido (12.5 t∙ha−1∙y−1. Among the LCLU types, the highest soil loss rates of 11 t∙ha−1∙y−1 and 10.6 t∙ha−1∙y−1 were found in moderate natural forest and dense natural forest, respectively, mainly due to their locations in highland areas characterized by steep slopes ranging between 16% to 21% and their high rainfall intensity, ranging from 1255 mm∙y−1 to 1292 mm∙y−1. Only five protected areas in Uganda were found to have high mean estimated mean soil loss rates >10 t∙ha−1∙y−1: Rwenzori Mountains (142.94 t∙ha−1∙y−1, Mount Elgon (33.81 t∙ha−1∙y−1, Bokora corridor (12.13 t∙ha−1∙y−1

  12. Estimating erosion in a riverine watershed: Bayou Liberty-Tchefuncta River in Louisiana.

    Science.gov (United States)

    Martin, August; Gunter, James T; Regens, James L

    2003-01-01

    GOAL, SCOPE, BACKGROUND: Sheet erosion from agricultural, forest and urban lands may increase stream sediment loads as well as transport other pollutants that adversely affect water quality, reduce agricultural and forest production, and increase infrastructure maintenance costs. This study uses spatial analysis techniques and a numerical modeling approach to predict areas with the greatest sheet erosion potential given different soils disturbance scenarios. A Geographic Information System (GIS) and the Universal Soil Loss Equation (USLE) were used to estimate sheet erosion from 0.64 ha parcels of land within the watershed. The Soil Survey of St. Tammany Parish, Louisiana was digitized, required soil attributes entered into the GIS database, and slope factors determined for each 80 x 80 meter parcel in the watershed. The GIS/USLE model used series-specific erosion K factors, a rainfall factor of 89, and a GIS database of scenario-driven cropping and erosion control practice factors to estimate potential soil loss due to sheet erosion. A general trend of increased potential sheet erosion occurred for all land use categories (urban, agriculture/grasslands, forests) as soil disturbance increases from cropping, logging and construction activities. Modeling indicated that rapidly growing urban areas have the greatest potential for sheet erosion. Evergreen and mixed forests (production forest) had lower sheet erosion potentials; with deciduous forests (mostly riparian) having the least sheet erosion potential. Erosion estimates from construction activities may be overestimated because of the value chosen for the erosion control practice factor. This study illustrates the ease with which GIS can be integrated with the Universal Soil Loss Equation to identify areas with high sheet erosion potential for large scale management and policy decision making. The GIS/USLE modeling approach used in this study offers a quick and inexpensive tool for estimating sheet erosion within

  13. Preventing erosion at pipeline crossings of watercourses

    International Nuclear Information System (INIS)

    Sawatsky, L.; Arnold, G.

    1997-01-01

    Watercourses are naturally vulnerable to erosion but the risk is particularly acute after sub-soil and armour materials have been disturbed by trenching and backfilling during construction. Various types of erosion (river scour, river bed, river channel bed and river bank ) and the progressive removal of pipeline cover resulting from erosion were discussed. Methods of estimating the risk of progressive erosion, river avulsions and beaver dam scour, and methods of mitigating erosion at pipeline crossings such as deep burial, proper siting, conventional armouring, and a combination of bank toe protection, and upper bank vegetation cover, were described

  14. Erosivity factor in the Universal Soil Loss Equation estimated from Finnish rainfall data

    Directory of Open Access Journals (Sweden)

    Maximilian Posch

    1993-07-01

    Full Text Available Continuous rainfall data recorded for many years at 8 stations in Finland were used to estimate rainfall erosivity, a quantity needed for soil loss predictions with the Universal Soil Loss Equation (USLE. The obtained erosivity values were then used to determine the 2 parameters of a power-law function describing the relationship between daily precipitation and erosivity. This function is of importance in erosion modeling at locations where no breakpoint rainfall data are available. The parameters of the power-law were estimated both by linear regression of the log-transformed data and by non-linear least-square fitting of the original data. Results indicate a considerable seasonal (monthly variation of the erosivity, whereas the spatial variation over Finland is rather small.

  15. High bone sialoprotein (BSP expression correlates with increased tumor grade and predicts a poorer prognosis of high-grade glioma patients.

    Directory of Open Access Journals (Sweden)

    Tao Xu

    Full Text Available OBJECTIVES: To investigate the expression and prognostic value of bone sialoprotein (BSP in glioma patients. METHODS: We determined the expression of BSP using real-time RT-PCR and immunohistochemistry in tissue microarrays containing 15 normal brain and 270 glioma samples. Cumulative survival was calculated by the Kaplan-Meier method and analyzed by the log-rank test. Univariate and multivariate analyses were performed by the stepwise forward Cox regression model. RESULTS: Both BSP mRNA and protein levels were significantly elevated in high-grade glioma tissues compared with those of normal brain and low-grade glioma tissues, and BSP expression positively correlated with tumor grade (P<0.001. Univariate and multivariate analysis showed high BSP expression was an independent prognostic factor for a shorter progression-free survival (PFS and overall survival (OS in both grade III and grade IV glioma patients [hazard ratio (HR = 2.549 and 3.154 for grade III glioma, and HR = 1.637 and 1.574 for grade IV glioma, respectively]. Patients with low BSP expression had a significantly longer median OS and PFS than those with high BSP expression. Small extent of resection and lineage of astrocyte served as independent risk factors of both shorter PFS and OS in grade III glioma patients; GBM patients without O(6-methylguanine (O(6-meG DNA methyltransferase (MGMT methylation and Karnofsky performance score (KPS less than 70 points were related to poor prognosis. Lack of radiotherapy related to shorter OS but not affect PFS in both grade III and grade IV glioma patients. CONCLUSION: High BSP expression occurs in a significant subset of high-grade glioma patients and predicts a poorer outcome. The study identifies a potentially useful molecular marker for the categorization and targeted therapy of gliomas.

  16. Soil Erosion Threatens Food Production

    Directory of Open Access Journals (Sweden)

    Michael Burgess

    2013-08-01

    Full Text Available Since humans worldwide obtain more than 99.7% of their food (calories from the land and less than 0.3% from the oceans and aquatic ecosystems, preserving cropland and maintaining soil fertility should be of the highest importance to human welfare. Soil erosion is one of the most serious threats facing world food production. Each year about 10 million ha of cropland are lost due to soil erosion, thus reducing the cropland available for world food production. The loss of cropland is a serious problem because the World Health Organization and the Food and Agricultural Organization report that two-thirds of the world population is malnourished. Overall, soil is being lost from agricultural areas 10 to 40 times faster than the rate of soil formation imperiling humanity’s food security.

  17. Bone banking.

    Science.gov (United States)

    Howard, W

    1999-04-01

    The use of human organs and tissues for transplantation in Australia has increased significantly over the past 30 years. In 1997, the Australian Coordinating Committee on Organ Registries and Donation (ACCORD) reported a total number of 190 organ donors, 636 corneal donors and 1509 bone donors Australia wide. Of the 1509 bone donations, 143 came from cadaveric sources and 1366 were made by living donors. Bone transplantation is not as widely recognised as solid organ or corneal transplantation. Due to improved technology and surgical skills, the demand for bone transplantation has increased markedly. This Clinical Update will provide an overview of the physiological aspects of bone transplantation and explore bone banking, a key step in the complex and critical process of bone transplantation.

  18. On inhibition of dental erosion.

    Science.gov (United States)

    Rölla, Gunnar; Jonski, Grazyna; Saxegaard, Erik

    2013-11-01

    To examine the erosion-inhibiting effect of different concentrations of hydrofluoric acid. Thirty-six human molars were individually treated with 10 ml of 0.1 M citric acid for 30 min (Etch 1), acid was collected and stored until analysis. The teeth were randomly divided into six groups and then individually treated with 10 ml of one of six dilutions (from 0.1-1%) of hydrofluoric acid. The teeth were then again treated with citric acid (Etch 2). The individual acid samples from Etch 1 and 2 were analyzed for calcium by flame atomic absorption spectroscopy and difference in calcium loss was calculated. The highest erosion inhibiting effect was obtained in groups with the highest concentrations of hydrofluoric acid, where the pH was lowest, below pKa of 3.17, thus the hydrofluoric acids being mainly in an undissociated state. Diluted hydrofluoric acid is present in aqueous solution of SnF2 and TiF4 (which are known to inhibit dental erosion): SnF2 + 3H2O = Sn(OH)2 + 2HF + H2O and TiF4 + 5H2O = Ti(OH)4 + 4HF + H2O. It is also known that pure, diluted hydrofluoric acid can inhibit dental erosion. Teeth treated with hydrofluoric acid are covered by a layer of CaF2-like mineral. This mineral is acid resistant at pH acid resistant mineral, initiated by tooth enamel treatment with hydrofluoric acid. Hydrofluoric acid is different in having fluoride as a conjugated base, which provides this acid with unique properties.

  19. Erosive forms in rivers systems

    International Nuclear Information System (INIS)

    Una Alvarez, E. de; Vidal Romani, J. R.; Rodriguez Martinez-Conde, R.

    2009-01-01

    The purpose of this work is to analyze the geomorphological meaning of the concepts of stability/change and to study its influence on a fluvial erosion system. Different cases of fluvial potholes in Galicia (NW of the Iberian Peninsula) are considered. The work conclusions refer to the nature of the process and its morphological evolution in order to advance towards later contributions with respect of this type of systems. (Author) 14 refs.

  20. The Impact of Climate Change in Rainfall Erosivity Index on Humid Mudstone Area

    Science.gov (United States)

    Yang, Ci-Jian; Lin, Jiun-Chuan

    2017-04-01

    It has been quite often pointed out in many relevant studies that climate change may result in negative impacts on soil erosion. Then, humid mudstone area is highly susceptible to climate change. Taiwan has extreme erosion in badland area, with annual precipitation over 2000 mm/y which is a considerably 3 times higher than other badland areas around the world, and with around 9-13 cm/y in denudation rate. This is the reason why the Erren River, a badland dominated basin has the highest mean sediment yield in the world, over 105 t km2 y. This study aims to know how the climate change would affect soil erosion from the source in the Erren River catchment. Firstly, the data of hourly precipitation from 1992 to 2016 are used to establish the regression between rainfall erosivity index (R, one of component for USLE) and precipitation. Secondly, using the 10 climate change models (provide form IPCC AR5) simulates the changes of monthly precipitation in different scenario from 2017 to 2216, and then over 200 years prediction R values can be use to describe the tendency of soil erosion in the future. The results show that (1) the relationship between rainfall erosion index and precipitation has high correction (>0.85) during 1992-2016. (2) From 2017 to 2216, 7 scenarios show that annual rainfall erosion index will increase over 2-18%. In contrast, the others will decrease over 7-14%. Overall, the variations of annual rainfall erosion index fall in the range of -14 to 18%, but it is important to pay attention to the variation of annual rainfall erosion index in extreme years. These fall in the range of -34 to 239%. This explains the extremity of soil erosion will occur easily in the future. Keywords: Climate Change, Mudstone, Rainfall Erosivity Index, IPCC AR5

  1. Erosion corrosion in wet steam

    International Nuclear Information System (INIS)

    Tavast, J.

    1988-03-01

    The effect of different remedies against erosion corrosion in wet steam has been studied in Barsebaeck 1. Accessible steam systems were inspected in 1984, 1985 and 1986. The effect of hydrogen peroxide injection of the transport of corrosion products in the condensate and feed water systems has also been followed through chemical analyses. The most important results of the project are: - Low alloy chromium steels with a chromium content of 1-2% have shown excellent resistance to erosion corrosion in wet steam. - A thermally sprayed coating has shown good resistance to erosion corrosion in wet steam. In a few areas with restricted accessibility minor attacks have been found. A thermally sprayed aluminium oxide coating has given poor results. - Large areas in the moisture separator/reheater and in steam extraction no. 3 have been passivated by injection of 20 ppb hydrogen peroxide to the high pressure steam. In other inspected systems no significant effect was found. Measurements of the wall thickness in steam extraction no. 3 showed a reduced rate of attack. - The injection of 20 ppb hydrogen peroxide has not resulted in any significant reduction of the iron level result is contrary to that of earlier tests. An increase to 40 ppb resulted in a slight decrease of the iron level. - None of the feared disadvantages with hydrogen peroxide injection has been observed. The chromium and cobalt levels did not increase during the injection. Neither did the lifetime of the precoat condensate filters decrease. (author)

  2. Injection of demineralized bone matrix with bone marrow concentrate improves healing in unicameral bone cyst.

    Science.gov (United States)

    Di Bella, Claudia; Dozza, Barbara; Frisoni, Tommaso; Cevolani, Luca; Donati, Davide

    2010-11-01

    Unicameral bone cysts are benign lesions that usually spontaneously regress with skeletal maturity; however, the high risk of pathologic fractures often justifies treatment that could reinforce a weakened bone cortex. Various treatments have been proposed but there is no consensus regarding the best procedure. We compared the healing rates and failures of two methods of cure based on multiple injections of corticosteroid or a single injection of demineralized bone matrix (DBM) in association with bone marrow concentrate (BMC). We retrospectively reviewed 184 patients who had one of the two treatments for unicameral bone cysts with cortical erosion. Clinical records were reviewed for treatment failures and radiographs for healing in all patients. The minimum followup was 12 months for the Steroids Group (mean, 48 months; range, 12-120 months) and 12 months for the DBM + BMC Group (mean, 20 months; range, 12-28 months). After one treatment we observed a lower healing rate of cysts treated with multiple injections of steroids compared with the healing after the first injection of DBM + BMC (21% versus 58%, respectively). At last followup, 38% healed with steroids and 71% with DBM + BMC. The rate of failure after one steroid injection was higher than after a single injection of BDM + BMC (63% versus 24%, respectively). We observed no difference in fracture rates after treatment between the two groups. A single injection of DBM added with autologous bone marrow concentrate appears to provide a higher healing rate with a lower number of failures compared with a single injection of steroids.

  3. Carpal erosions in children with juvenile idiopathic arthritis: repeatability of a newly devised MR-scoring system

    Energy Technology Data Exchange (ETDEWEB)

    Boavida, Peter [Great Ormond Street Hospital for Children, Department of Radiology, London (United Kingdom); Lambot-Juhan, Karen [Hospital Necker Enfants Malades, Department of Radiology, Paris (France); Ording Mueller, Lil-Sofie [Oslo University Hospital, Department of Radiology, Oslo (Norway); Damasio, Beatrice; Malattia, Clara [Ospedale Pediatrico Gaslini, Department of Rheumatology, Genoa (Italy); Tanturri de Horatio, Laura [Ospedale Pediatrico Bambino Gesu, Department of Radiology, Rome (Italy); Owens, Catherine M. [Great Ormond Street Hospital for Children, Department of Radiology, London (United Kingdom); UCL, Institute of Child Health, London (United Kingdom); Rosendahl, Karen [Haukeland University Hospital, Department of Radiology, Bergen (Norway); University of Bergen, Department of Clinical Medicine, Bergen (Norway)

    2015-12-15

    Juvenile idiopathic arthritis (JIA) is characterized by synovial inflammation, with potential risk of developing progressive joint destruction. Personalized state-of-the-art treatment depends on valid markers for disease activity to monitor response; however, no such markers exist. To evaluate the reliability of scoring of carpal bone erosions on MR in children with JIA using two semi-quantitative scoring systems. A total of 1,236 carpal bones (91 MR wrist examinations) were scored twice by two independent pediatric musculoskeletal radiologists. Bony erosions were scored according to estimated bone volume loss using a 0-4 scale and a 0-10 scale. An aggregate erosion score comprising the sum total carpal bone volume loss was calculated for each examination. The 0-4 scoring system resulted in good intra-reader agreement and moderate to good inter-observer agreement in the assessment of individual bones. Fair and moderate agreement were achieved for inter-reader and intra-reader agreement, respectively, using the 0-10 scale. Intra- and particularly inter-reader aggregate score variability were much less favorable, with wide limits of agreement. Further analysis of erosive disease patterns compared with normal subjects is required, and to facilitate the development of an alternative means of quantifying disease. (orig.)

  4. Carpal erosions in children with juvenile idiopathic arthritis: repeatability of a newly devised MR-scoring system

    International Nuclear Information System (INIS)

    Boavida, Peter; Lambot-Juhan, Karen; Ording Mueller, Lil-Sofie; Damasio, Beatrice; Malattia, Clara; Tanturri de Horatio, Laura; Owens, Catherine M.; Rosendahl, Karen

    2015-01-01

    Juvenile idiopathic arthritis (JIA) is characterized by synovial inflammation, with potential risk of developing progressive joint destruction. Personalized state-of-the-art treatment depends on valid markers for disease activity to monitor response; however, no such markers exist. To evaluate the reliability of scoring of carpal bone erosions on MR in children with JIA using two semi-quantitative scoring systems. A total of 1,236 carpal bones (91 MR wrist examinations) were scored twice by two independent pediatric musculoskeletal radiologists. Bony erosions were scored according to estimated bone volume loss using a 0-4 scale and a 0-10 scale. An aggregate erosion score comprising the sum total carpal bone volume loss was calculated for each examination. The 0-4 scoring system resulted in good intra-reader agreement and moderate to good inter-observer agreement in the assessment of individual bones. Fair and moderate agreement were achieved for inter-reader and intra-reader agreement, respectively, using the 0-10 scale. Intra- and particularly inter-reader aggregate score variability were much less favorable, with wide limits of agreement. Further analysis of erosive disease patterns compared with normal subjects is required, and to facilitate the development of an alternative means of quantifying disease. (orig.)

  5. Erosion estimation of guide vane end clearance in hydraulic turbines with sediment water flow

    Science.gov (United States)

    Han, Wei; Kang, Jingbo; Wang, Jie; Peng, Guoyi; Li, Lianyuan; Su, Min

    2018-04-01

    The end surface of guide vane or head cover is one of the most serious parts of sediment erosion for high-head hydraulic turbines. In order to investigate the relationship between erosion depth of wall surface and the characteristic parameter of erosion, an estimative method including a simplified flow model and a modificatory erosion calculative function is proposed in this paper. The flow between the end surfaces of guide vane and head cover is simplified as a clearance flow around a circular cylinder with a backward facing step. Erosion characteristic parameter of csws3 is calculated with the mixture model for multiphase flow and the renormalization group (RNG) k-𝜀 turbulence model under the actual working conditions, based on which, erosion depths of guide vane and head cover end surfaces are estimated with a modification of erosion coefficient K. The estimation results agree well with the actual situation. It is shown that the estimative method is reasonable for erosion prediction of guide vane and can provide a significant reference to determine the optimal maintenance cycle for hydraulic turbine in the future.

  6. Experimental comparison of cavitation erosion rates of different steels used in hydraulic turbines

    International Nuclear Information System (INIS)

    Ton-That, L

    2010-01-01

    The prediction of cavitation erosion rates has an important role in order to evaluate the exact life of components in fluid machineries. Hydro-Quebec has studied this phenomenon for several years, in particular in hydraulic turbine runners, to try to understand the different degradation mechanisms related to this phenomenon. This paper presents part of this work. In this study, we carried out experimental erosion tests to compare different steels used in actual hydraulic turbine runners (carbon steels, austenitic and martensitic stainless steels) to high strength steels in terms of cavitation erosion resistance. The results for these different classes of steels are presented. The tests have been performed in a cavitating liquid jet apparatus according to the ASTM G134-95 standard to simulate the flow conditions. The mass loss has been followed during the exposure time. The maximum depth of erosion, the mean depth of erosion, and the mean depth erosion rate are determined. As a result we found that ASTM-A514 high strength steels present excellent cavitation erosion resistance properties. The cavitation eroded surface is followed by optical profilometry technique. Determination of mechanical properties and examinations of the eroded surfaces of the samples have also been carried out in order to identify the erosion mechanisms involved in the degradation of these kinds of materials.

  7. Dental erosion prevalence and associated risk indicators among preschool children in Athens, Greece.

    Science.gov (United States)

    Mantonanaki, Magdalini; Koletsi-Kounari, Haroula; Mamai-Homata, Eleni; Papaioannou, William

    2013-03-01

    The aims of the study were to investigate dental erosion prevalence, distribution and severity in Greek preschool children attending public kindergartens in the prefecture of Attica, Greece and to determine the effect of dental caries, oral hygiene level, socio-economic factors, dental behavior, erosion related medication and chronic illness. A random and stratified sample of 605 Greek preschool children was clinically examined for dental erosion using the Basic Erosive Wear Examination Index (ΒΕWE). Dental caries (dmfs) and Simplified Debris Index were also recorded. The data concerning possible risk indicators were derived by a questionnaire. Zero-inflated Poisson regression was generated to test the predictive effects of the independent variables on dental erosion. The prevalence of dental erosion was 78.8 %, and the mean and SE of BEWE index was 3.64 ± 0.15. High monthly family income was positively related to ΒΕWE cumulative scores [RR = 1.204 (1.016-1.427)], while high maternal education level [RR = 0.872 (0.771-0.986)] and poor oral hygiene level [DI-s, RR = 0.584 (0.450-0.756)] showed a negative association. Dental erosion is a common oral disease in Greek preschool children in Attica, related to oral hygiene and socio-economic factors. Programs aimed at erosion prevention should begin at an early age for all children.

  8. Erosion by flowing lava: Geochemical evidence in the Cave Basalt, Mount St. Helens, Washington

    Science.gov (United States)

    Williams, D.A.; Kadel, S.D.; Greeley, R.; Lesher, C.M.; Clynne, M.A.

    2004-01-01

    We sampled basaltic lava flows and underlying dacitic tuff deposits in or near lava tubes of the Cave Basalt, Mount St. Helens, Washington to determine whether the Cave Basalt lavas contain geochemical evidence of substrate contamination by lava erosion. The samples were analyzed using a combination of wavelength-dispersive X-ray fluorescence spectrometry and inductively-coupled plasma mass spectrometry. The results indicate that the oldest, outer lava tube linings in direct contact with the dacitic substrate are contaminated, whereas the younger, inner lava tube linings are uncontaminated and apparently either more evolved or enriched in residual liquid. The most heavily contaminated lavas occur closer to the vent and in steeper parts of the tube system, and the amount of contamination decreases with increasing distance downstream. These results suggest that erosion by lava and contamination were limited to only the initially emplaced flows and that erosion was localized and enhanced by vigorous laminar flow over steeper slopes. After cooling, the initial Cave Basalt lava flows formed an insulating lining within the tubes that prevented further erosion by later flows. This interpretation is consistent with models of lava erosion that predict higher erosion rates closer to sources and over steeper slopes. A greater abundance of xenoliths and xenocrysts relative to xenomelts in hand samples indicates that mechanical erosion rather than thermal erosion was the dominant erosional process in the Cave Basalt, but further sampling and petrographic analyses must be performed to verify this hypothesis. ?? Springer-Verlag 2003.

  9. On the role of "internal variability" on soil erosion assessment

    Science.gov (United States)

    Kim, Jongho; Ivanov, Valeriy; Fatichi, Simone

    2017-04-01

    Empirical data demonstrate that soil loss is highly non-unique with respect to meteorological or even runoff forcing and its frequency distributions exhibit heavy tails. However, all current erosion assessments do not describe the large associated uncertainties of temporal erosion variability and make unjustified assumptions by relying on central tendencies. Thus, the predictive skill of prognostic models and reliability of national-scale assessments have been repeatedly questioned. In this study, we attempt to reveal that the high variability in soil losses can be attributed to two sources: (1) 'external variability' referring to the uncertainties originating at macro-scale, such as climate, topography, and land use, which has been extensively studied; (2) 'geomorphic internal variability' referring to the micro-scale variations of pedologic properties (e.g., surface erodibility in soils with multi-sized particles), hydrologic properties (e.g., soil structure and degree of saturation), and hydraulic properties (e.g., surface roughness and surface topography). Using data and a physical hydraulic, hydrologic, and erosion and sediment transport model, we show that the geomorphic internal variability summarized by spatio-temporal variability in surface erodibility properties is a considerable source of uncertainty in erosion estimates and represents an overlooked but vital element of geomorphic response. The conclusion is that predictive frameworks of soil erosion should embed stochastic components together with deterministic assessments, if they do not want to largely underestimate uncertainty. Acknowledgement: This study was supported by the Basic Science Research Program of the National Research Foundation of Korea funded by the Ministry of Education (2016R1D1A1B03931886).

  10. Using albedo to reform wind erosion modelling, mapping and monitoring

    Science.gov (United States)

    Chappell, Adrian; Webb, Nicholas P.

    2016-12-01

    Wind erosion and dust emission models are used to assess the impacts of dust on radiative forcing in the atmosphere, cloud formation, nutrient fertilisation and human health. The models are underpinned by a two-dimensional geometric property (lateral cover; L) used to characterise the three-dimensional aerodynamic roughness (sheltered area or wakes) of the Earth's surface and calibrate the momentum it extracts from the wind. We reveal a fundamental weakness in L and demonstrate that values are an order of magnitude too small and significant aerodynamic interactions between roughness elements and their sheltered areas have been omitted, particularly under sparse surface roughness. We describe a solution which develops published work to establish a relation between sheltered area and the proportion of shadow over a given area; the inverse of direct beam directional hemispherical reflectance (black sky albedo; BSA). We show direct relations between shadow and wind tunnel measurements and thereby provide direct calibrations of key aerodynamic properties. Estimation of the aerodynamic parameters from albedo enables wind erosion assessments over areas, across platforms from the field to airborne and readily available satellite data. Our new approach demonstrated redundancy in existing wind erosion models and thereby reduced model complexity and improved fidelity. We found that the use of albedo enabled an adequate description of aerodynamic sheltering to characterise fluid dynamics and predict sediment transport without the use of a drag partition scheme (Rt) or threshold friction velocity (u∗t). We applied the calibrations to produce global maps of aerodynamic properties which showed very similar spatial patterns to each other and confirmed the redundancy in the traditional parameters of wind erosion modelling. We evaluated temporal patterns of predicted horizontal mass flux at locations across Australia which revealed variation between land cover types that would not

  11. Comparison of erosion and erosion control works in Macedonia, Serbia and Bulgaria

    Directory of Open Access Journals (Sweden)

    Ivan Blinkov

    2013-12-01

    Natural conditions in the Balkan countries contribute to the appearance of various erosion forms and the intensity of the erosion processes. Over the history of these countries, people who settled this region used the available natural resources to fill their needs (tree cutting, incorrect plugging, overgrazing, which contributed to soil erosion. Organized erosion control works in the Balkans started in the beginning of the 20th century (1905 in Bulgaria. The highest intensity of erosion control works were carried out during the period 1945 – 1990. Various erosion control works were launched. Bulgaria had a large anti-erosion afforestation, almost 1 million ha. Bulgaria's ecological river restoration approach has been in use for almost 50 years. Serbia contributed significant erosion and torrent control works on hilly agricultural areas. Specific screen barrages and afforestation on extremely dry areas are characteristic in Macedonia. A common characteristic for all countries is a high decrease in erosion control works in the last 20 years.

  12. New approaches to the estimation of erosion-corrosion

    International Nuclear Information System (INIS)

    Bakirov, Murat; Ereemin, Alexandr; Levchuck, Vasiliy; Chubarov, Sergey

    2006-09-01

    erosion-corrosion in a double-phase flow is that of moving deaerated liquid in directly contact with metal as a barrier between the metal and main steam-drop flow. Local processes of mass transfer, corrosion properties and water-chemical parameters of this film define intensity of erosion-corrosion and features of its behavior. Erosion-corrosion of metal in a double-phase flow is determined by the gas-dynamics of double-phase flaws, water chemistry, thermodynamic, materials science, etc. The goal of the work: development of theoretical and methodological basis of physical, chemical and mathematical models, as well as the finding of technical solutions and method of diagnostics, forecast and control of the erosion-corrosion processes. It will allow the increase of reliability and safety operation of the power equipment of the secondary circuit in NPP with WWER by use of monitoring of erosion-corrosion wear of pipelines. One concludes by stressing that the described design-experimental approach for solving of FAC problem will enable to carry out the following works: - elaboration and certification of the procedure of design-experimental substantiation of zones, aims and periodicity of the NPP elements operational inspection; - development and certification of a new Regulatory Document of stress calculation for definition of the minimum acceptable wall thickness levels considering real wear shape, FAC rates and inaccuracy of devices for wall thickness measurements; - improving the current Regulatory Documents and correcting of the Typical programs of operational inspection - optimization of zones, aims and periodicity of the inspection; - elaboration of recommendations for operational lifetime prolongation of the WWER secondary circuits elements by means of increasing of erosion-corrosion resistance of the new equipment and of the equipment, exceeding the design lifetime; - improving of safe and uninterrupted work of the power unit due to prediction of the most damaged

  13. Component wall thinning and a corrosion-erosion monitoring system

    International Nuclear Information System (INIS)

    Bogard, T.; Batt, T.; Roarty, D.

    1989-01-01

    Since a 1986 incident involving failure of a piping elbow due to erosion-corrosion, the electric utility industry has been actively developing technology for implementing long term programs to address corrosion-erosion. This paper describes a typical corrosion-erosion monitoring program, the types of non-destructive examinations (NDE) performed on components, and the extensive NDE data obtained when the program is applied to components in a power plant. To facilitate evaluation of the NDE data on components, an automated NDE data manipulation and data display system is advisable and perhaps necessary due to the large amounts of NDE data typically obtained during a program. Such a comprehensive corrosion-erosion monitoring system (CEMS) needs to be integral with methods for selection of inspection locations and perform NDE data analysis to help in replace, repair, or run decisions. The structure for one CEMS is described which uses IBM PC compatible hardware and a set of software addressing most data evaluation and decision making needs. CEMS features include automated input/output for typical NDE devices, database structuring, graphics outputs including color 2-D or 3-D contour plots of components, trending and predictive evaluations for future inspection planning, EC severity determination, integration of piping isometrics and component properties, and desktop publishing capabilities

  14. Aging and bone. X-ray bone densitometry

    Energy Technology Data Exchange (ETDEWEB)

    Morita, Rikushi (Shiga Univ. of Medical Sciences, Otsu (Japan))

    1994-01-01

    Bone mass at all ages of the individuals is the integration of genetic factors, nutrition, physical exercise, hormonal environments, and other factors influencing the bone. It is also a measurable risk factor for osteoporosis which may subsequently cause bone fractures. Thus measuring bone mass is required to predict the probability of developing bone fractures subsequent to osteoporosis, and to diagnose osteoporosis, and to manage the osteoporosis patient. This paper discusses bone mineral measurements according to their characteristics and clinical application. Methodology for measuring bone mass has rapidly progressed during the past 15 years, which covers photodensitometry, photon absorptiometry (single energy X-ray absorptiometry and dual energy X-ray absorptiometry), quantitative CT, and ultrasound. These techniques have allowed noninvasive measurement of bone mineral density in any site of the skeleton with high accuracy and precision, although a single use of the technique cannot satisfy the complete clinical requirements. Thus the most appropriate method for measuring bone mineral density is important to monitor bone mass change and according to the specific site. (N.K.).

  15. Bone graft viability evaluated by three phase bone scan

    International Nuclear Information System (INIS)

    Ljiljana Jaukovic Rajko Spaic; Marijan Novakovic; Srbislav Stosic

    2004-01-01

    Bone defects resulting war injury can be replaced by microvascular bone grafts from fibula. Aim: The aim of this study was to assess the value of three phase (3P) bone scintigraphy in the early detection of the bone graft complications. Method: 3P bone scans were performed in four patients (two after mandible reconstruction with micro vascular fibular bone grafts, one after fibular transplantation for ulnar and one with humeral reconstruction). First dynamic phase scan was performed immediately after iv injection of 740 MBq Tc- 99m DPD, acquiring 15 two seconds duration frames. Second, early static scan was performed during next 300 seconds, and third, delayed scan three hours later. All scans were obtained under the bone graft region. The scans were evaluated using ROI under graft region and the corresponding contra lateral area. Blood flow in graft region was determined using first phase scan, and tracer uptake in the same region was determined using second and third phase scans. Results: in all patients blood flow in graft region was particularly normal. Tracer uptake in one of two patients with mandible reconstruction was diffusely increased in graft, strongly suggesting infection; In the other patient delayed scan showed no tracer uptake in graft center .Both patients with ulnar and humeral reconstruction showed only slightly decreased tracer uptake in bone grafts. 3 phase bone scintigraphy may play a role in the evaluation of bone graft viability by predicting the infection and necrosis. (authors)

  16. Aging and bone. X-ray bone densitometry

    International Nuclear Information System (INIS)

    Morita, Rikushi

    1994-01-01

    Bone mass at all ages of the individuals is the integration of genetic factors, nutrition, physical exercise, hormonal environments, and other factors influencing the bone. It is also a measurable risk factor for osteoporosis which may subsequently cause bone fractures. Thus measuring bone mass is required to predict the probability of developing bone fractures subsequent to osteoporosis, and to diagnose osteoporosis, and to manage the osteoporosis patient. This paper discusses bone mineral measurements according to their characteristics and clinical application. Methodology for measuring bone mass has rapidly progressed during the past 15 years, which covers photodensitometry, photon absorptiometry (single energy X-ray absorptiometry and dual energy X-ray absorptiometry), quantitative CT, and ultrasound. These techniques have allowed noninvasive measurement of bone mineral density in any site of the skeleton with high accuracy and precision, although a single use of the technique cannot satisfy the complete clinical requirements. Thus the most appropriate method for measuring bone mineral density is important to monitor bone mass change and according to the specific site. (N.K.)

  17. Bone development

    DEFF Research Database (Denmark)

    Tatara, M.R.; Tygesen, Malin Plumhoff; Sawa-Wojtanowicz, B.

    2007-01-01

    The objective of this study was to determine the long-term effect of alpha-ketoglutarate (AKG) administration during early neonatal life on skeletal development and function, with emphasis on bone exposed to regular stress and used to serve for systemic changes monitoring, the rib. Shropshire ram.......01). Furthermore, AKG administration induced significantly higher bone mineral density of the cortical bone by 7.1% (P

  18. TILLAGE EROSION: THE PRINCIPLES, CONTROLLING FACTORS AND MAIN IMPLICATIONS FOR FUTURE RESEARCH

    Directory of Open Access Journals (Sweden)

    Agnieszka Wysocka-Czubaszek

    2014-10-01

    Full Text Available Tillage erosion is one of the major contributors to landscape evolution in hummocky agricultural landscapes. This paper summarizes the available data describing tillage erosion caused by hand-held or other simple tillage implements as well as tools used in typical conventional agriculture in Europe and North America. Variations in equipment, tillage speed, depth and direction result in a wide range of soil translocation rates observed all over the world. The variety of tracers both physical and chemical gives a challenge to introduce the reliable model predicting tillage erosion, considering the number and type of tillage operation in the whole tillage sequence.

  19. A One-Dimensional Global-Scaling Erosive Burning Model Informed by Blowing Wall Turbulence

    Science.gov (United States)

    Kibbey, Timothy P.

    2014-01-01

    A derivation of turbulent flow parameters, combined with data from erosive burning test motors and blowing wall tests results in erosive burning model candidates useful in one-dimensional internal ballistics analysis capable of scaling across wide ranges of motor size. The real-time burn rate data comes from three test campaigns of subscale segmented solid rocket motors tested at two facilities. The flow theory admits the important effect of the blowing wall on the turbulent friction coefficient by using blowing wall data to determine the blowing wall friction coefficient. The erosive burning behavior of full-scale motors is now predicted more closely than with other recent models.

  20. Relationship among panoramic radiography findings, biochemical markers of bone turnover and hip bone mineral density in the diagnosis of postmenopausal osteoporosis

    International Nuclear Information System (INIS)

    Johari Khatoonabad, M.; Aghamohammadzade, N.; Taghilu, H.; Esmaeili, F.; Jabbari Khamnei, H.

    2011-01-01

    Recent investigations have shown that panoramic radiography might be a useful tool in the early diagnosis of osteoporosis. In addition, bone turnover biochemical marker might be valuable in predicting osteoporosis and fracture risks in the elderly, especially in post-menopausal women. The aim of the present study was to evaluate the relationship among the radio morphometric indices of the mandible, biochemical markers of the bone turnover and hip bone mineral density in a group of post-menopausal women. Patients and Methods: Evaluations of mandibular cortical width, mandibular cortical index, panoramic index and alveolar crest resorption ration (M/M ration) were carried out on panoramic radiographs of 140 post-menopausal women with an age range of 44-82 years. Hip bone mineral density was measured by dual-energy X-ray absorptiometry method. Bone mineral density values were divided into three groups of normal (T score>-1.0), Osteopenic (T score, -2.5 to -1.0) and Osteoporotic (T score<-2.5). Serum alkaline phosphatase and 25(OH) D3 were measured. Results: A decrease in mandibular cortical width by 1 mm increases the likelihood of osteopenia or osteoporosis up to 40%, having taken into consideration the effect of menopause duration. A 1 mm decrease in mandibular cortical width increased the likelihood of moderate or severe erosion of the lower cortex of the mandible up to 28% by taking age into consideration. The results did not demonstrate a statistically significant relationship between bone turnover markers and mandibular radio morphometric indices. Conclusion: Panoramic radiography gives sufficient information to make an early diagnosis regarding osteoporosis in post-menopausal women. Panoramic radiographs may be valuable in the prevention of osteoporotic fractures in elderly women.

  1. Mechanical consequences of different scenarios for simulated bone atrophy and recovery in the distal radius

    NARCIS (Netherlands)

    Pistoia, W.; Rietbergen, van B.; Rüegsegger, P.

    2003-01-01

    Metabolic bone diseases such as osteoporosis usually cause a decrease in bone mass and a deterioration of bone microarchitecture leading to a decline in bone strength. Methods to predict bone strength in patients are currently based on bone mass only. It has been suggested that an improved

  2. Rainfall erosivity in subtropical catchments and implications for erosion and particle-bound contaminant transfer: a case-study of the Fukushima region

    Science.gov (United States)

    Laceby, J. P.; Chartin, C.; Evrard, O.; Onda, Y.; Garcia-Sanchez, L.; Cerdan, O.

    2015-07-01

    The Fukushima Dai-ichi nuclear power plant (FDNPP) accident in March 2011 resulted in a significant fallout of radiocesium over the Fukushima region. After reaching the soil surface, radiocesium is almost irreversibly bound to fine soil particles. Thereafter, rainfall and snow melt run-off events transfer particle-bound radiocesium downstream. Erosion models, such as the Universal Soil Loss Equation (USLE), depict a proportional relationship between rainfall and soil erosion. As radiocesium is tightly bound to fine soil and sediment particles, characterizing the rainfall regime of the fallout-impacted region is fundamental to modelling and predicting radiocesium migration. Accordingly, monthly and annual rainfall data from ~ 60 meteorological stations within a 100 km radius of the FDNPP were analysed. Monthly rainfall erosivity maps were developed for the Fukushima coastal catchments illustrating the spatial heterogeneity of rainfall erosivity in the region. The mean average rainfall in the Fukushima region was 1387 mm yr-1 (σ 230) with the mean rainfall erosivity being 2785 MJ mm ha-1 yr-1 (σ 1359). The results indicate that the majority of rainfall (60 %) and rainfall erosivity (86 %) occurs between June and October. During the year, rainfall erosivity evolves positively from northwest to southeast in the eastern part of the prefecture, whereas a positive gradient from north to south occurs in July and August, the most erosive months of the year. During the typhoon season, the coastal plain and eastern mountainous areas of the Fukushima prefecture, including a large part of the contamination plume, are most impacted by erosive events. Understanding these rainfall patterns, particularly their spatial and temporal variation, is fundamental to managing soil and particle-bound radiocesium transfers in the Fukushima region. Moreover, understanding the impact of typhoons is important for managing sediment transfers in subtropical regions impacted by cyclonic activity.

  3. Current and future assessments of soil erosion by water on the Tibetan Plateau based on RUSLE and CMIP5 climate models.

    Science.gov (United States)

    Teng, Hongfen; Liang, Zongzheng; Chen, Songchao; Liu, Yong; Viscarra Rossel, Raphael A; Chappell, Adrian; Yu, Wu; Shi, Zhou

    2018-04-18

    Soil erosion by water is accelerated by a warming climate and negatively impacts water security and ecological conservation. The Tibetan Plateau (TP) has experienced warming at a rate approximately twice that observed globally, and heavy precipitation events lead to an increased risk of erosion. In this study, we assessed current erosion on the TP and predicted potential soil erosion by water in 2050. The study was conducted in three steps. During the first step, we used the Revised Universal Soil Equation (RUSLE), publicly available data, and the most recent earth observations to derive estimates of annual erosion from 2002 to 2016 on the TP at 1-km resolution. During the second step, we used a multiple linear regression (MLR) model and a set of climatic covariates to predict rainfall erosivity on the TP in 2050. The MLR was used to establish the relationship between current rainfall erosivity data and a set of current climatic and other covariates. The coefficients of the MLR were generalised with climate covariates for 2050 derived from the fifth phase of the Coupled Model Intercomparison Project (CMIP5) models to estimate rainfall erosivity in 2050. During the third step, soil erosion by water in 2050 was predicted using rainfall erosivity in 2050 and other erosion factors. The results show that the mean annual soil erosion rate on the TP under current conditions is 2.76tha -1 y -1 , which is equivalent to an annual soil loss of 559.59×10 6 t. Our 2050 projections suggested that erosion on the TP will increase to 3.17tha -1 y -1 and 3.91tha -1 y -1 under conditions represented by RCP2.6 and RCP8.5, respectively. The current assessment and future prediction of soil erosion by water on the TP should be valuable for environment protection and soil conservation in this unique region and elsewhere. Copyright © 2018 Elsevier B.V. All rights reserved.

  4. Coastal erosion problem, modelling and protection

    Science.gov (United States)

    Yılmaz, Nihal; Balas, Lale; İnan, Asu

    2015-09-01

    Göksu Delta, located in the south of Silifke County of Mersin on the coastal plain formed by Göksu River, is one of the Specially Protected Areas in Turkey. Along the coastal area of the Delta, coastline changes at significant rates are observed, concentrating especially at four regions; headland of İncekum, coast of Paradeniz Lagoon, river mouth of Göksu and coast of Altınkum. The coast of Paradeniz Lagoon is suffering significantly from erosion and the consequent coastal retreating problem. Therefore, the narrow barrier beach which separates Paradeniz Lagoon from the Mediterranean Sea is getting narrower, creating a risk of uniting with the sea, thus causing the disappearance of the Lagoon. The aim of this study was to understand the coastal transport processes along the coastal area of Göksu Delta to determine the coastal sediment transport rates, and accordingly, to propose solutions to prevent the loss of coastal lands in the Delta. To this end, field measurements of currents and sediment grain sizes were carried out, and wind climate, wave climate, circulation patterns and longshore sediment transport rates were numerically modeled by HYDROTAM-3D, which is a three dimensional hydrodynamic transport model. Finally, considering its special importance as an environmentally protected region, some coastal structures of gabions were proposed as solutions against the coastal erosion problems of the Delta. The effects of proposed structures on future coastline changes were also modeled, and the coastlines predicted for the year 2017 are presented and discussed in the paper.

  5. Slurry Erosion Performance of Ni-Al2O3 Based Thermal-Sprayed Coatings: Effect of Angle of Impingement

    Science.gov (United States)

    Grewal, H. S.; Agrawal, Anupam; Singh, H.; Shollock, B. A.

    2014-02-01

    In this paper, slurry erosion performance of high velocity flame-sprayed Ni-Al2O3 based coatings was evaluated. The coatings were deposited on a hydroturbine steel (CA6NM) by varying the content of Al2O3 in Ni. Using jet-type test rig, erosion behavior of coatings and bare steel was evaluated at different impingement angles. Detailed investigation of the surface morphology of the eroded specimens was undertaken using SEM/EDS to identify potential erosion mechanism. A parameter named "erosion mechanism identifier" (ξ) was used to predict the mode of erosion. It was observed that the coating prepared using 40 wt.% of Al2O3 showed a highest resistance to erosion. This coating enhanced the erosion resistance of the steel by 2 to 4 times. Spalling in the form of splats and chunks of material (formed by interlinking of cracks) along with fracture of Al2O3 splats were identified as primary mechanisms responsible for the loss of coating material. The erosion mechanism of coatings and bare steel predicted by ξ was in good agreement with that observed experimentally. Among different parameters,, a function of fracture toughness ( K IC) and hardness ( H) showed excellent correlation with erosion resistance of coatings at both the impingement angles.

  6. The comparison of various approach to evaluation erosion risks and design control erosion measures

    Science.gov (United States)

    Kapicka, Jiri

    2015-04-01

    In the present is in the Czech Republic one methodology how to compute and compare erosion risks. This methodology contain also method to design erosion control measures. The base of this methodology is Universal Soil Loss Equation (USLE) and their result long-term average annual rate of erosion (G). This methodology is used for landscape planners. Data and statistics from database of erosion events in the Czech Republic shows that many troubles and damages are from local episodes of erosion events. An extent of these events and theirs impact are conditional to local precipitation events, current plant phase and soil conditions. These erosion events can do troubles and damages on agriculture land, municipally property and hydro components and even in a location is from point of view long-term average annual rate of erosion in good conditions. Other way how to compute and compare erosion risks is episodes approach. In this paper is presented the compare of various approach to compute erosion risks. The comparison was computed to locality from database of erosion events on agricultural land in the Czech Republic where have been records two erosion events. The study area is a simple agriculture land without any barriers that can have high influence to water flow and soil sediment transport. The computation of erosion risks (for all methodology) was based on laboratory analysis of soil samples which was sampled on study area. Results of the methodology USLE, MUSLE and results from mathematical model Erosion 3D have been compared. Variances of the results in space distribution of the places with highest soil erosion where compared and discussed. Other part presents variances of design control erosion measures where their design was done on based different methodology. The results shows variance of computed erosion risks which was done by different methodology. These variances can start discussion about different approach how compute and evaluate erosion risks in areas

  7. Comparative evaluation of experimental and theoretical erosion resistance of materials upon electric pulse treatment

    International Nuclear Information System (INIS)

    Karpman, M.G.; Fetisov, G.P.; Bologov, D.V.

    1999-01-01

    Using the Palatnik criterion a comparative analysis is performed of the theoretical and experimental data on comparative electric erosion and erosion resistance of the electrodes and parts made of different materials upon their treatment using electric pulse technique. A reasonable qualitative agreement of the theoretical and experimental data indicates the possibility of using the Palatnik criterion to predict the serviceability of different pairs of the materials in conditions of electroerosion wear [ru

  8. High defect stage, contralateral defects, and poor flexibility are negative predictive factors of bone union in pediatric and adolescent athletes with spondylolysis.

    Science.gov (United States)

    Yamazaki, Kazufumi; Kota, Shintaro; Oikawa, Daisuke; Suzuki, Yoshiji

    2018-01-01

    To identify predisposition to spondylolysis and physical characteristics associated with "bone union" following conservative spondylolysis treatment among pediatric and adolescent athletes. We retrospectively analyzed pediatric and adolescent athletes with spondylolysis who underwent conservative treatment and rehabilitation for three or more consecutive months following sports activity cessation. Patients with terminal spondylolysis or who did not discontinue sports activities were excluded. We compared physical fitness factors in the union and nonunion groups and examined the association between bone union and spondylolysis severity by logistic regression analysis. Of 183 patients with spondylolysis who underwent rehabilitation over a four-year period, 127 patients with 227 defects were included in the final analysis. Bone union was achieved in 66.5% (151/227) of the pars interarticularis defects and 70.1% (89/127) of the patients. On multivariate analysis, stage of pars interarticularis defect (odds ratio [OR], 0.26;p = 0.0027), stage of contralateral pars interarticularis defect (OR, 0.51;p = 0.00026), and straight leg-raising test (OR, 1.06;p = 0.028) were significantly associated with bone union. High defect stage, stage of the contralateral pars interarticularis defect, and poor flexibility were negative prognostic factors of bone healing in athletes with spondylolysis. J. Med. Invest. 65:126-130, February, 2018.

  9. Cavitation erosion - scale effect and model investigations

    Science.gov (United States)

    Geiger, F.; Rutschmann, P.

    2015-12-01

    The experimental works presented in here contribute to the clarification of erosive effects of hydrodynamic cavitation. Comprehensive cavitation erosion test series were conducted for transient cloud cavitation in the shear layer of prismatic bodies. The erosion pattern and erosion rates were determined with a mineral based volume loss technique and with a metal based pit count system competitively. The results clarified the underlying scale effects and revealed a strong non-linear material dependency, which indicated significantly different damage processes for both material types. Furthermore, the size and dynamics of the cavitation clouds have been assessed by optical detection. The fluctuations of the cloud sizes showed a maximum value for those cavitation numbers related to maximum erosive aggressiveness. The finding suggests the suitability of a model approach which relates the erosion process to cavitation cloud dynamics. An enhanced experimental setup is projected to further clarify these issues.

  10. Erosion and sedimentation caused by watercourse regulation

    International Nuclear Information System (INIS)

    Dahl, T.E.; Godtland, K.

    1995-01-01

    This report describes the observations made by SINTEF NHL in 1993 - 1994 on the development of erosion in three regulated lakes in Norway: Devdesjavri, Store Maalvatn and Gjevilvatnet. Surveys, profile levelling, water sample analyses, aerial photography etc were all used. Erosion was dramatic in all three magazines the first year of regulation and then slowed down. It has since remained relatively stable. However, there is a risk of further strong erosion connected with flooding tributaries, notably at low water such as usually occurs in spring. This is true in particular of the main river discharging into Devdesjavri, which is subject to landslides, wave and river erosion. In addition, ground water erosion may occur if the magazine is drained too fast. The report is lavishly illustrated with colour pictures of the effects of erosion. 21 refs., 15 figs., 13 tabs

  11. Varioliform erosions in the stomach and duodenum

    Energy Technology Data Exchange (ETDEWEB)

    Lotz, W.; Schulz, D.; Munkel, G.

    1984-04-01

    One thousand five hundred and eighty-three patients who were x-rayed for dyspepsia showed varioliform erosions in 15.3%. Men had an incidence of 9.8%, almost twice as common as in women (5.5%). Mucosal polyps, usually of the hyperplastic type, occurred in 2.4%. 15% of patients with gastric ulcers and 16% of patients with duodenal ulcers had varioliform erosions. On the other hand, amongst patients with erosions, 11% had gastric ulcers and 8.3% duodenal ulcers. The definitions of erosion which have been given in the literature are partly contradictory, and are discussed. Varioliform erosions, also known as complete erosions, may be acute or chronic. They are the third most common cause of bleeding from the upper gastrointestinal tract. With modern radiological methods of examining the stomach, they are no longer a rare finding. 5 figs.

  12. Varioliform erosions in the stomach and duodenum

    International Nuclear Information System (INIS)

    Lotz, W.; Schulz, D.; Munkel, G.

    1984-01-01

    One thousand five hundred and eighty-three patients who were x-rayed for dyspepsia showed varioliform erosions in 15.3%. Men had an incidence of 9.8%, almost twice as common as in women (5.5%). Mucosal polyps, usually of the hyperplastic type, occurred in 2.4%. 15% of patients with gastric ulcers and 16% of patients with duodenal ulcers had varioliform erosions. On the other hand, amongst patients with erosions, 11% had gastric ulcers and 8.3% duodenal ulcers. The definitions of erosion which have been given in the literature are partly contradictory, and are discussed. Varioliform erosions, also known as complete erosions, may be acute or chronic. They are the third most common cause of bleeding from the upper gastrointestinal tract. With modern radiological methods of examining the stomach, they are no longer a rare finding. (orig.) [de

  13. Assessment and management of dental erosion.

    Science.gov (United States)

    Wang, Xiaojie; Lussi, Adrian

    2010-07-01

    Studies have shown a growing trend toward increasing prevalence of dental erosion, associated with the declining prevalence of caries disease in industrialized countries. Erosion is an irreversible chemical process that results in tooth substance loss and leaves teeth susceptible to damage as a result of wear over the course of an individual's lifetime. Therefore, early diagnosis and adequate prevention are essential to minimize the risk of tooth erosion. Clinical appearance is the most important sign to be used to diagnose erosion. The Basic Erosive Wear Examination (BEWE) is a simple method to fulfill this task. The determination of a variety of risk and protective factors (patient-dependent and nutrition-dependent factors) as well as their interplay are necessary to initiate preventive measures tailored to the individual. When tooth loss caused by erosive wear reaches a certain level, oral rehabilitation becomes necessary. Copyright 2010 Elsevier Inc. All rights reserved.

  14. DENTAL EROSION IN PRIMARY DENTITION- A REVIEW

    Directory of Open Access Journals (Sweden)

    Rafi Shaik

    2017-06-01

    Full Text Available BACKGROUND The pattern of oral diseases has been influenced by ever changing human lifestyle. Tooth wear especially dental erosion has drawn increasing attention as risk factor for tooth damage or loss in recent years. It is a common condition in primary dentition compared to permanent dentition due to thinner and less mineralised enamel. However, it is more worrying, when this condition is being found in an alarming proportion among children. The presence of dental erosion in children is likely to be associated with a number of general health and dietary factors, but it is also aggravated by the relatively more rapid progression of erosion in the deciduous teeth. An understanding of the aetiologies and risk factors for erosion is important for early recognition of dental erosion to prevent serious irreversible damage to the dentition. This paper discusses the erosion in children with regard to its epidemiology, prevalence, clinical features, measurement and prevention.

  15. PROBLEMS OF SOIL PROTECTION FROM EROSION

    OpenAIRE

    M. Voloshuk; Natalia Kiriak

    2007-01-01

    In this article the problems of soil protection from erosion in Moldova are considered. The history (evolution) of erosive processes is generalized, the first items of information on presence washed off soils are marked. Purposeful study of soil erosion, development of measures of struggle with it were begun in Moldova at the end of 40 years. In connection with transition to new economic methods of conducting economy (farmers, rent, privatization of land) before pedologist, the experts of des...

  16. GEOSTATISTICAL BASED SUSCEPTIBILITY MAPPING OF SOIL EROSION AND OPTIMIZATION OF ITS CAUSATIVE FACTORS: A CONCEPTUAL FRAMEWORK

    Directory of Open Access Journals (Sweden)

    ABDULKADIR T. SHOLAGBERU

    2017-11-01

    Full Text Available Soil erosion hazard is the second biggest environmental challenges after population growth causing land degradation, desertification and water deterioration. Its impacts on watersheds include loss of soil nutrients, reduced reservoir capacity through siltation which may lead to flood risk, landslide, high water turbidity, etc. These problems become more pronounced in human altered mountainous areas through intensive agricultural activities, deforestation and increased urbanization among others. However, due to challenging nature of soil erosion management, there is great interest in assessing its spatial distribution and susceptibility levels. This study is thus intend to review the recent literatures and develop a novel framework for soil erosion susceptibility mapping using geostatistical based support vector machine (SVM, remote sensing and GIS techniques. The conceptual framework is to bridge the identified knowledge gaps in the area of causative factors’ (CFs selection. In this research, RUSLE model, field studies and the existing soil erosion maps for the study area will be integrated for the development of inventory map. Spatial data such as Landsat 8, digital soil and geological maps, digital elevation model and hydrological data shall be processed for the extraction of erosion CFs. GISbased SVM techniques will be adopted for the establishment of spatial relationships between soil erosion and its CFs, and subsequently for the development of erosion susceptibility maps. The results of this study include evaluation of predictive capability of GIS-based SVM in soil erosion mapping and identification of the most influential CFs for erosion susceptibility assessment. This study will serve as a guide to watershed planners and to alleviate soil erosion challenges and its related hazards.

  17. Volumetric measurement of river bank erosion from sequential historical aerial photography

    Science.gov (United States)

    Spiekermann, Raphael; Betts, Harley; Dymond, John; Basher, Les

    2017-11-01

    Understanding of the relative contribution of bank erosion to sediment budgets in New Zealand is limited. Few measurements of bank erosion rates exist, and this is a major limitation to the development of a locally calibrated model of bank erosion. The New Zealand sediment budget model, SedNetNZ, predicts bank erosion based on preliminary data, and this study aims to underpin the development of an improved model for bank erosion. Photogrammetric techniques and LiDAR were used to collect data on bank erosion rates for five different river reaches, ranging from 3 to 14 km in length, in the Kaipara Catchment, Northland, New Zealand. Changing river channel planform between the 1950s and 2015 was assessed using four to five well-spaced dates of historical aerial photographs. Changes in planform were combined with bank height, to calculate erosion and accretion volumes which were compared with SedNetNZ modelled estimates. Erosion and accretion is relatively evenly balanced in the study sites. The largest difference in terms of relative proportions of erosion and accretion are found along the Tangowahine River (13.4 km reach length), where 492,000 m3 of sediment eroded between 1956 and 2015 compared to 364,000 m3 of accretion. Lateral migration rates (erosion) for the five river reaches range between 0.14 m yr- 1 and 0.21 m yr- 1 and are comparable with those measured by previous assessments in New Zealand. The migration rates in channel widths per year for the three larger rivers (stream order 5-6) range between 0.4% and 0.8% of channel width per year. In contrast, the smaller streams (stream order 3-4) are retreating more rapidly, with width-averaged rates of 1.7% and 3.0%. Current SedNetNZ modelling tends to underestimate the bank height and greatly overestimates the migration rate.

  18. Radiographic study of bone changes on TMJ arthrosis

    International Nuclear Information System (INIS)

    You, Dong Soo

    1982-01-01

    The author analyzed the morphologic changes of bone structures from 1256 radiographs of 314 patients with temporomandibular joint arthrosis, which were obtained by the oblique-lateral projection and orthopantomography. The interrelations of the bone changes and clinical symptoms were examined. Also, the positional relationships of condylar head, articular fossa and articular eminence in the mouth open and closed state were observed in the patients with bone changes. The results were as follows; 1. The most frequent bone change in the TMJ arthrosis was eburnation of cortical bone (35.64%) of total cases. Then came bone surface erosion and localized radiolucency (26.18%), marginal proliferation (9.7%) and flattening of articular surface (9.58%) in that order. 2. The most frequent site of bone change was articular eminence (41.70%). The came condylar head (21.09%) and articular fossa (20.73%) in that order. 3. In the patients with bone changes, their clinical symptoms were pain (51.55%), clicking sound during mandibular movement (37.71%) and limited mandibular movement (10.73%). In the patients complaining pain, their radiographs showed eburnation of cortical bone (30.68%), bone surface erosion and localized radiolucency (27.45%) and flattening in the (30.68%), bone surface erosion and localized radiolucency (27.45%) and flattening of articular surface (10.68%). 4. The condylar positional changes in the TMJ arthrosis patients with bone changes were as follows: in the mouth closed state, there were the widening of joint space in 624 cases (50.00%), the narrowing of joint space in 543 cases (43.47%) and bone on bone relationships in 82 cases (6.57%). In the mouth open state, there were forward positioning of the condyle in 332 cases (28.55%), limitation of movement in 332 cases (28.55%), bone on bone relationships in 248 cases (21.31%) and downward positioning of condyle in 217 cases (18.66%). Bone on bone relationships in 248 cases (21.32%) and downward positioning of

  19. Radiographic study of bone changes on TMJ arthrosis

    Energy Technology Data Exchange (ETDEWEB)

    You, Dong Soo [Dept. of Radiology, College of Dentistry, Seoul National University, Seoul (Korea, Republic of)

    1982-11-15

    The author analyzed the morphologic changes of bone structures from 1256 radiographs of 314 patients with temporomandibular joint arthrosis, which were obtained by the oblique-lateral projection and orthopantomography. The interrelations of the bone changes and clinical symptoms were examined. Also, the positional relationships of condylar head, articular fossa and articular eminence in the mouth open and closed state were observed in the patients with bone changes. The results were as follows; 1. The most frequent bone change in the TMJ arthrosis was eburnation of cortical bone (35.64%) of total cases. Then came bone surface erosion and localized radiolucency (26.18%), marginal proliferation (9.7%) and flattening of articular surface (9.58%) in that order. 2. The most frequent site of bone change was articular eminence (41.70%). The came condylar head (21.09%) and articular fossa (20.73%) in that order. 3. In the patients with bone changes, their clinical symptoms were pain (51.55%), clicking sound during mandibular movement (37.71%) and limited mandibular movement (10.73%). In the patients complaining pain, their radiographs showed eburnation of cortical bone (30.68%), bone surface erosion and localized radiolucency (27.45%) and flattening in the (30.68%), bone surface erosion and localized radiolucency (27.45%) and flattening of articular surface (10.68%). 4. The condylar positional changes in the TMJ arthrosis patients with bone changes were as follows: in the mouth closed state, there were the widening of joint space in 624 cases (50.00%), the narrowing of joint space in 543 cases (43.47%) and bone on bone relationships in 82 cases (6.57%). In the mouth open state, there were forward positioning of the condyle in 332 cases (28.55%), limitation of movement in 332 cases (28.55%), bone on bone relationships in 248 cases (21.31%) and downward positioning of condyle in 217 cases (18.66%). Bone on bone relationships in 248 cases (21.32%) and downward positioning of

  20. Experiment of cavitation erosion at the exit of a long orifice

    Energy Technology Data Exchange (ETDEWEB)

    Yagi, Yoshinori; Murase, Michio [Inst. of Nuclear Safety System Inc., Mihama, Fukui (Japan)

    2002-09-01

    We performed experiments to clarify mechanism of cavitation erosion and to predict cavitation erosion rate at the exit of a long orifice equipped at the chemical and volume control system in a pressurized water reactor (PWR). In order to find this mechanism, we used a high speed video camera. As the result, we observed bubble collapses near the exit of the orifice when flow condition was oscillating. So the bubble collapses due to the oscillation might cause the first stage erosion at the exit of the orifice. Using the orifice which had the cone-shaped exit, we observed that bubbles collapsed near the exit and then they collapsed at the upstream like a chain reaction. So this bubble collapse mechanism could be explained as follows: shock wave was generated by the bubble collapse near the exit, then it propagated upwards, consequently it caused the bubble collapse at the upstream. And we predicted erosion rate by evaluating the effect of the velocity and comparing the erosion resistance between the test speciment (aluminum) and the plant material (stainless steel) by means of vibratory tests. We compared the predicted erosion rate with that of the average value estimated from plant investigation, then we examined the applicability of these method to the plant evaluations. (author)

  1. Rill erosion of mudstone slope-a case study of southern Taiwan

    Science.gov (United States)

    Yang, Ci-Jian; Lin, Jiun-chuan; Cheng, Yuan-Chang

    2014-05-01

    Soil erosion has been studied by many scientists for decades (Zingg, 1940; Meyer & Wischmeier, 1969; Foster, 1982; Luk, 1988) and many soil erosion prediction equations have already been developed, such as USLE, RUSLE. In spite of WEEP is based on hydrological physical model, all of the above models are restricted to predict concentrate flow. On the other hand, rill erosion is not understood completely. The amounts of rill erosion are always underestimated. Rill Erosion correlate closely to gradient (Cerda & Garcia-Fayos, 1997; Fox & Bryan, 1999; Fu,et al., 2011; Clarke & Rendell, 2006), slope length (Gabriel, 1999; Yair, 2004), particle distribution (Gabriel, 1999), proportion of clay (Luk,1977; Bryan2000), rainfall intensity (Römkens et al. 2001), and land use (Dotterweich, 2008). However, the effect of micromorphology of mud rock surface, such as mud-cracks, could be studied in more details. This research aims to simulate rill development by hydraulic flume to observe the morphological change caused by rill/erosion process. Mudstone specimens sampled from the mudstone area of Long-Chi, southern Taiwan. The results show that: (1) The erosion pattern of mudstone slope can be divided into four steps: (a) inter-rill erosion, ( b) rill erosion, (c) rill development, (d) slope failure. (2) Slopes with mud-cracks caused 125% soil loss than smooth slopes. (3) Mud-cracks affect spatial distribution of rill development (4) The sediment concentration decreased sharply in the beginning of experiments, however increased due to rill development. This paper demonstrated such a rill development. 1: Department of Geography, National Taiwan University. E-mail:maxpossibilism0929@gmail.com

  2. Erosion products in disruption simulation experiments

    International Nuclear Information System (INIS)

    Safronov, V.; Arkhipov, N.; Bakhtin, V.; Barsuk, V.; Kurkin, S.; Mironova, E.; Toporkov, D.; Vasenin, S.; Zhitlukhin, A.; Arkhipov, I.; Werle, H.; Wuerz, H.

    1998-01-01

    Erosion of divertor materials under tokamak disruption event presents a serious problem of ITER technology. Erosion restricts the divertor lifetime and leads to production of redeposited layers of the material retaining large amount of tritium, which is a major safety issue for future fusion reactor. Since ITER disruptive heat loads are not achievable in existing tokamaks, material erosion is studied in special simulation experiments. Till now the simulation experiments have focused mainly on investigation of shielding effect and measurement of erosion rate. In the present work the properties of eroded and redeposited graphite are studied under condition typical for hard ITER disruption. (author)

  3. Reduction of surface erosion in fusion reactors

    International Nuclear Information System (INIS)

    Rossing, T.D.; Das, S.K.; Kaminsky, M.

    1976-01-01

    Some of the major processes leading to surface erosion in fusion reactors are reviewed briefly, including blistering by implanted gas, sputtering by ions, atoms, and neutrons, and vaporization by local heating. Surface erosion affects the structural integrity and limits the lifetime of reactor components exposed to plasma radiation. In addition, some of the processes leading to surface erosion also cause the release of plasma contaminants. Methods proposed to reduce surface erosion have included control of surface temperature, selection of materials with a favorable microstructure, chemical and mechanical treatment of surfaces, and employment of protective surface coatings, wall liners, and divertors. The advantages and disadvantages of some of these methods are discussed

  4. Erosive lichen planus: a therapeutic challenge.

    Science.gov (United States)

    Romero, Williams; Giesen, Laura; Navajas-Galimany, Lucas; Gonzalez, Sergio

    2016-01-01

    Erosive lichen planus is an uncommon variant of lichen planus. Chronic erosions of the soles, accompanied by intense and disabling pain, are some of its most characteristic manifestations. We present the case of a woman who developed oral and plantar erosive lichen planus associated with lichen planus pigmentosus and ungueal lichen planus that were diagnosed after several years. The patient failed to respond to multiple therapies requiring longstanding medication but remained refractory. Knowledge of the treatment options for erosive lichen planus is insufficient. Further research is required to clarify their effectiveness, ideally adopting an evidence-based methodology.

  5. Robotic weld overlay coatings for erosion control

    Science.gov (United States)

    The erosion of materials by the impact of solid particles has received increasing attention during the past twenty years. Recently, research has been initiated with the event of advanced coal conversion processes in which erosion plays an important role. The resulting damage, termed Solid Particle Erosion (SPE), is of concern primarily because of the significantly increased operating costs which result in material failures. Reduced power plant efficiency due to solid particle erosion of boiler tubes and waterfalls has led to various methods to combat SPE. One method is to apply coatings to the components subjected to erosive environments. Protective weld overlay coatings are particularly advantageous in terms of coating quality. The weld overlay coatings are essentially immune to spallation due to a strong metallurgical bond with the substrate material. By using powder mixtures, multiple alloys can be mixed in order to achieve the best performance in an erosive environment. However, a review of the literature revealed a lack of information on weld overlay coating performance in erosive environments which makes the selection of weld overlay alloys a difficult task. The objective of this project is to determine the effects of weld overlay coating composition and microstructure on erosion resistance. These results will lead to a better understanding of erosion mitigation in CFB's.

  6. Broken bone

    Science.gov (United States)

    ... Drugs & Supplements Videos & Tools Español You Are Here: Home → Medical Encyclopedia → Broken bone URL of this page: //medlineplus.gov/ency/ ... following steps to reduce your risk of a broken bone: Wear protective ... pads. Create a safe home for young children. Place a gate at stairways ...

  7. Amplified Erosion above Waterfalls and Oversteepened Bedrock Reaches

    Science.gov (United States)

    Haviv, I.; Enzel, Y.; Whipple, K. X.; Zilberman, E.; Stone, J.; Matmon, A.; Fifield, K. L.

    2005-12-01

    Although waterfalls are abundant along steep bedrock channels, none of the conventional erosion laws can predict incision at the lip of a waterfall where flow is non-uniform and bed slope can be vertical. Considering the expected increase in flow velocity and shear stress at the lip of a vertical waterfall we determine erosion amplification at a waterfall lip as: Elip/Enormal= (1+0.4/Fr2)3n, where Fr is the Froude number and n ranges between 0.5-1.7. This amplification expression suggests that erosion at the lip could be as much as 2-5 times higher than normally expected in a setting with identical hydraulic geometry. It also demonstrates that a freefall is expected to amplify upstream incision rates even when the flow approaching the waterfall is highly supercritical. Utilizing this erosion amplification expression in numerical simulations in conjunction with a standard detachment-limited incision model we demonstrate its impact on reach-scale morphology above waterfalls. These simulations indicate that amplified erosion at the lip of a waterfall can trigger the formation of an oversteepened reach whose length is longer than the flow acceleration zone, provided incision velocity (Vi) at the edge of the flow acceleration zone is higher than the retreat velocity of the waterfall face. Such an oversteepened reach is expected to be more pronounced when Vi increases with increasing slope. The simulations also suggest that oversteepening can eventually lead to quasi steady-state gradients upstream from a waterfall provided Vi decreases with increasing slope. Flow acceleration above waterfalls can thus account, at least partially, for oversteepened bedrock reaches that are prevalent above waterfalls. Such reaches have been reported for the escarpments of southeast Australia, western Dead Sea, and at Niagara Falls. Using the cosmogenic isotope 36Cl we demonstrate that Vi upstream of a waterfall at the Dead Sea western escarpment is high enough for freefall

  8. Preventing erosive risks after wildfire in Spain: advances and gaps

    Science.gov (United States)

    Fernández Filgueira, Cristina; Vega Hidalgo, José A.; Fontúrbel Lliteras, Teresa

    2017-04-01

    Galicia (NW Spain) is one of the most wildfire-affected areas in Western Europe and where the highest soil losses following fire are recorded in the Iberian Peninsula. During the last decade, mitigation of hydrological and erosive risk has been an important objective for researchers and forest managers. For this reason, research carried out has focused on three main issues: i) the development of operational tools to prioritize post-fire soil stabilization actions, based on soil burn severity indicators and remote sensed information, and testing of their ability to reflect degradation risk in relevant soil properties and subsequent soil erosion, ii) the development and testing of different soil stabilization treatments and their effectiveness for reducing erosion, following their application at broad scale, under the specific environmental conditions of Galicia and iii) the assessment of the performance of current erosion models as well as the development of empirical models to predict post-fire soil losses. On the other hand, the use of forest resources is an essential component of the regional incomes in NW Spain and consequently there is a pressing necessity for investigation on techniques suitable for reconciling soil conservation and sustainable use of those resources. In the framework of wildfire impacts this involve many and complex challenges. This scenario contrast with most of the Iberian Peninsula under Mediterranean influence where salvage logging is not a priority. As in other regions, post-fire hydrologic and erosive risk modeling, including threatened resources vulnerability evaluation is also a capital research need, particularly in a climate change context where dramatic changes in drivers such as precipitation, evapotranspiration and fire regime are expected. The study was funded by the National Institute of Agricultural Research of Spain (INIA) through project RTA2014-00011-C06-02, cofunded by FEDER and the Plan de Mejora e Innovación Forestal de

  9. Bone densitometry

    DEFF Research Database (Denmark)

    Ravn, Pernille; Alexandersen, P; Møllgaard, A

    1999-01-01

    The bisphosphonates have been introduced as alternatives to hormone replacement therapy (HRT) for the treatment and prevention of postmenopausal osteoporosis. The expected increasing application in at clinical practice demands cost-effective and easily handled methods to monitor the effect on bone....... The weak response at the distal forearm during antiresorptive treatment has restricted the use of bone densitometry at this region. We describe a new model for bone densitometry at the distal forearm, by which the response obtained is comparable to the response in other regions where bone densitometry...... is much more expensive and technically complicated. By computerized iteration of single X-ray absorptiometry forearm scans we defined a region with 65% trabecular bone. The region was analyzed in randomized, double-masked, placebo- controlled trials: a 2-year trial with alendronate (n = 69), a 1-year...

  10. The influence of rill density on soil erosion against USLE-soil erosion methode

    OpenAIRE

    Rizalihadi, A.M.; Faimah, B.E.; Nazia, C.L.

    2013-01-01

    Land and water is one of the major natural resource which has an important role for human life. Exploitation of land in catchment areas that not correspond to its carrying capacity will cause damage. One of the effect is increassing the soil erosion. Continuous erosion will also lead to increased sediment transport in rivers that disrupt the ship navigation on estuary due sediment accumulation. At present, soil erosion is estimated using USLE method, which is only limited to the erosion in th...

  11. Quantifying accelerated soil erosion through ecological site-based assessments of wind and water erosion

    Science.gov (United States)

    This work explores how organising soil erosion assessments using established groupings of similar soils (ecological sites) can inform systems for managing accelerated soil erosion. We evaluated aeolian sediment transport and fluvial erosion rates for five ecological sites in southern New Mexico, USA...

  12. Farmers' identification of erosion indicators and related erosion damage in the Central Highlands of Kenya

    NARCIS (Netherlands)

    Sterk, G.; Okoba, B.O.

    2006-01-01

    Most soil and water conservation planning approaches rely on empirical assessment methods and hardly consider farmers' knowledge of soil erosion processes. Farmers' knowledge of on-site erosion indicators could be useful in assessing the site-specific erosion risk before planning any conservation

  13. Monthly Rainfall Erosivity Assessment for Switzerland

    Science.gov (United States)

    Schmidt, Simon; Meusburger, Katrin; Alewell, Christine

    2016-04-01

    Water erosion is crucially controlled by rainfall erosivity, which is quantified out of the kinetic energy of raindrop impact and associated surface runoff. Rainfall erosivity is often expressed as the R-factor in soil erosion risk models like the Universal Soil Loss Equation (USLE) and its revised version (RUSLE). Just like precipitation, the rainfall erosivity of Switzerland has a characteristic seasonal dynamic throughout the year. This inter-annual variability is to be assessed by a monthly and seasonal modelling approach. We used a network of 86 precipitation gauging stations with a 10-minute temporal resolution to calculate long-term average monthly R-factors. Stepwise regression and Monte Carlo Cross Validation (MCCV) was used to select spatial covariates to explain the spatial pattern of R-factor for each month across Switzerland. The regionalized monthly R-factor is mapped by its individual regression equation and the ordinary kriging interpolation of its residuals (Regression-Kriging). As covariates, a variety of precipitation indicator data has been included like snow height, a combination of hourly gauging measurements and radar observations (CombiPrecip), mean monthly alpine precipitation (EURO4M-APGD) and monthly precipitation sums (Rhires). Topographic parameters were also significant explanatory variables for single months. The comparison of all 12 monthly rainfall erosivity maps showed seasonality with highest rainfall erosivity in summer (June, July, and August) and lowest rainfall erosivity in winter months. Besides the inter-annual temporal regime, a seasonal spatial variability was detectable. Spatial maps of monthly rainfall erosivity are presented for the first time for Switzerland. The assessment of the spatial and temporal dynamic behaviour of the R-factor is valuable for the identification of more susceptible seasons and regions as well as for the application of selective erosion control measures. A combination with monthly vegetation

  14. Seasonality of soil erosion under mediterranean conditions at the Alqueva Dam watershed.

    Science.gov (United States)

    Ferreira, Vera; Panagopoulos, Thomas

    2014-07-01

    The Alqueva reservoir created the largest artificial lake of Western Europe in 2010. Since then, the region has faced challenges due to land-use changes that may increase the risk of erosion and shorten the lifetime of the reservoir, increasing the need to promote land management sustainability. This paper investigates the aspect of seasonality of soil erosion using a comprehensive methodology that integrates the Revised Universal Soil Loss Equation (RUSLE) approach, geographic information systems, geostatistics, and remote-sensing. An experimental agro-silvo pastoral area (typical land-use) was used for the RUSLE factors update. The study confirmed the effect of seasonality on soil erosion rates under Mediterranean conditions. The highest rainfall erosivity values occurred during the autumn season (433.6 MJ mm ha(-1) h(-1)), when vegetation cover is reduced after the long dry season. As a result, the autumn season showed the highest predicted erosion (9.9 t ha(-1)), contributing 65 % of the total annual erosion. The predicted soil erosion for winter was low (1.1 t ha(-1)) despite the high rainfall erosivity during that season (196.6 MJ mm ha(-1) h(-1)). The predicted annual soil loss was 15.1 t ha(-1), and the sediment amount delivery was 4,314 × 10(3) kg. Knowledge of seasonal variation would be essential to outline sustainable land management practices. This model will be integrated with World Overview of Conservation Approaches and Technologies methods to support decision-making in that watershed, and it will involve collaboration with both local people and governmental institutions.

  15. Spatial distribution of water erosion risk in a watershed with eucalyptus and Atlantic Forest

    Directory of Open Access Journals (Sweden)

    Junior Cesar Avanzi

    2013-10-01

    Full Text Available The process of water erosion occurs in watersheds throughout the world and it is strongly affected by anthropogenic influences. Thus, the knowledge of these processes is extremely necessary for planning of conservation efforts. This study was performed in an experimental forested watershed in order to predict the average potential annual soil loss by water erosion using the Universal Soil Loss Equation (USLE and a Geographic Information System (GIS, and then compared with soil loss tolerance. All the USLE factors were generated in a distributed approach employing a GIS tool. The layers were multiplied in the GIS framework in order to predict soil erosion rates. Results showed that the average soil loss was 6.2 Mg ha-1 yr-1. Relative to soil loss tolerance, 83% of the area had an erosion rate lesser than the tolerable value. According to soil loss classes, 49% of the watershed had erosion less than 2.5 Mg ha-1 yr-1. However, about 8.7% of the watershed had erosion rates greater than 15 Mg ha-1 yr-1, being mainly related to Plinthosol soil class and roads, thus requiring special attention for the improvement of sustainable management practices for such areas. Eucalyptus cultivation was found to have soil loss greater than Atlantic Forest. Thus, an effort should be made to bring the erosion rates closer to the native forest. Implementation of the USLE model in a GIS framework was found to be a simple and useful tool for predicting the spatial variation of soil erosion risk and identifying critical areas for conservation efforts.

  16. Age-predicted values for lumbar spine, proximal femur, and whole-body bone mineral density: results from a population of normal children aged 3 to 18 years

    Energy Technology Data Exchange (ETDEWEB)

    Webber, C.E. [Hamilton Health Sciences, Dept. of Nuclear Medicine, Hamilton, Ontario (Canada); McMaster Univ., Dept. of Radiology, Hamilton, Ontario (Canada)]. E-mail: webber@hhsc.ca; Beaumont, L.F. [Hamilton Health Sciences, Dept. of Nuclear Medicine, Hamilton, Ontario (Canada); Morrison, J. [McMaster Children' s Hospital, Hamilton, Ontario (Canada); Sala, A. [McMaster Children' s Hospital, Hamilton, Ontario (Canada); McMaster Univ., Dept. of Pediatrics, Hamilton, Ontario (Canada); Univ. of Milan-Bicocca, Monza (Italy); Barr, R.D. [McMaster Children' s Hospital, Hamilton, Ontario (Canada); McMaster Univ., Dept. of Pediatrics, Hamilton, Ontario (Canada)

    2007-02-15

    We measured areal bone mineral density (BMD) with dual-energy X-ray absorptiometry (DXA) at the lumbar spine and the proximal femur and for the total body in 179 subjects (91 girls and 88 boys) with no known disorders that might affect calcium metabolism. Results are also reported for lumbar spine bone mineral content (BMC) and for the derived variable, bone mineral apparent density (BMAD). Expected-for-age values for each variable were derived for boys and girls by using an expression that represented the sum of a steady increase due to growth plus a rapid increase associated with puberty. Normal ranges were derived by assuming that at least 95% of children would be included within 1.96 population standard deviations (SD) of the expected-for-age value. The normal range for lumbar spine BMD derived from our population of children was compared with previously published normal ranges based on results obtained from different bone densitometers in diverse geographic locations. The extent of agreement between the various normal ranges indicates that the derived expressions can be used for reporting routine spine, femur, and whole-body BMD measurements in children and adolescents. The greatest difference in expected-for-age values among the various studies was that arising from intermanufacturer variability. The application of published conversion factors derived from DXA measurements in adults did not account fully for these differences, especially in younger children. (author)

  17. Age-predicted values for lumbar spine, proximal femur, and whole-body bone mineral density: results from a population of normal children aged 3 to 18 years

    International Nuclear Information System (INIS)

    Webber, C.E.; Beaumont, L.F.; Morrison, J.; Sala, A.; Barr, R.D.

    2007-01-01

    We measured areal bone mineral density (BMD) with dual-energy X-ray absorptiometry (DXA) at the lumbar spine and the proximal femur and for the total body in 179 subjects (91 girls and 88 boys) with no known disorders that might affect calcium metabolism. Results are also reported for lumbar spine bone mineral content (BMC) and for the derived variable, bone mineral apparent density (BMAD). Expected-for-age values for each variable were derived for boys and girls by using an expression that represented the sum of a steady increase due to growth plus a rapid increase associated with puberty. Normal ranges were derived by assuming that at least 95% of children would be included within 1.96 population standard deviations (SD) of the expected-for-age value. The normal range for lumbar spine BMD derived from our population of children was compared with previously published normal ranges based on results obtained from different bone densitometers in diverse geographic locations. The extent of agreement between the various normal ranges indicates that the derived expressions can be used for reporting routine spine, femur, and whole-body BMD measurements in children and adolescents. The greatest difference in expected-for-age values among the various studies was that arising from intermanufacturer variability. The application of published conversion factors derived from DXA measurements in adults did not account fully for these differences, especially in younger children. (author)

  18. Hepatic disorders predicted from extrahepatic accumulation of activity in the bone marrow during hepatosplenic scintiscanning - retrospective analysis of 549 cases in 1979

    International Nuclear Information System (INIS)

    Gillessen, U.

    1983-01-01

    A total of 148 scintigrams recorded following administration of 99mTc-labeled stannous phenzaone colloid were analysed for extrahepatic accumulation of tracer substance in the bone marrow as well as for further pathological features. The results obtained were subsequently examined on the basis of the individual case reports and laboratory values. It could thus be shown that an increased accumulation of the radiopharmaceutical in the bone marrow may provide conclusive evidence of the underlying pat