62 research outputs found

    Updating ESA's Earth System Model for Gravity Mission Simulation Studies: 3. A Realistically Perturbed Non-Tidal Atmosphere and Ocean De-Aliasing Model

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    The ability of any satellite gravity mission concept to monitor mass transport processes in the Earth system is typically tested well ahead of its implementation by means of various simulation studies. Those studies often extend from the simulation of realistic orbits and instrumental data all the way down to the retrieval of global gravity field solution time-series. Basic requirement for all these simulations are realistic representations of the spatio-temporal mass variability in the different sub-systems of the Earth, as a source model for the orbit computations. For such simulations, a suitable source model is required to represent (i) high-frequency (i.e., sub-daily to weekly) mass variability in the atmosphere and oceans, in order to realistically include the effects of temporal aliasing due to non-tidal high-frequency mass variability into the retrieved gravity fields. In parallel, (ii) low-frequency (i.e., monthly to interannual) variability needs to be modelled with realistic amplitudes, particularly at small spatial scales, in order to assess to what extent a new mission concept might provide further insight into physical processes currently not observable. The new source model documented here attempts to fulfil both requirements: Based on ECMWF’s recent atmospheric reanalysis ERA-Interim and corresponding simulations from numerical models of the other Earth system components, it offers spherical harmonic coefficients of the time-variable global gravity field due to mass variability in atmosphere, oceans, the terrestrial hydrosphere including the ice-sheets and glaciers, as well as the solid Earth. Simulated features range from sub-daily to multiyear periods with a spatial resolution of spherical harmonics degree and order 180 over a period of 12 years. In addition to the source model, a de-aliasing model for atmospheric and oceanic high-frequency variability with augmented systematic and random noise is required for a realistic simulation of the gravity field retrieval process, whose necessary error characteristics are discussed. The documentation is organized as follows: The characteristics of the updated ESM along with some basic validation are presented in Volume 1 of this report (Dobslaw et al., 2014). A detailed comparison to the original ESA ESM (Gruber et al., 2011) is provided in Volume 2 (Bergmann-Wolf et al., 2014), while Volume 3 (Forootan et al., 2014) contains a description of the strategy to derive a realistically noisy de-aliasing model for the high-frequency mass variability in atmosphere and oceans. The files of the updated ESA Earth System Model for gravity mission simulation studies are accessible at DOI:10.5880/GFZ.1.3.2014.001

    Updating ESA's Earth System Model for gravity mission simulation studies: 2. Comparison with the original model

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    The ability of any satellite gravity mission concept to monitor mass transport processes in the Earth system is typically tested well ahead of its implementation by means of various simulation studies. Those studies often extend from the simulation of realistic orbits and instrumental data all the way down to the retrieval of global gravity field solution time-series. Basic requirement for all these simulations are realistic representations of the spatio-temporal mass variability in the different sub-systems of the Earth, as a source model for the orbit computations. For such simulations, a suitable source model is required to represent (i) high-frequency (i.e., sub-daily to weekly) mass variability in the atmosphere and oceans, in order to realistically include the effects of temporal aliasing due to non-tidal high-frequency mass variability into the retrieved gravity fields. In parallel, (ii) low-frequency (i.e., monthly to interannual) variability needs to be modelled with realistic amplitudes, particularly at small spatial scales, in order to assess to what extent a new mission concept might provide further insight into physical processes currently not observable. The new source model documented here attempts to fulfil both requirements: Based on ECMWF’s recent atmospheric reanalysis ERA-Interim and corresponding simulations from numerical models of the other Earth system components, it offers spherical harmonic coefficients of the time-variable global gravity field due to mass variability in atmosphere, oceans, the terrestrial hydrosphere including the ice-sheets and glaciers, as well as the solid Earth. Simulated features range from sub-daily to multiyear periods with a spatial resolution of spherical harmonics degree and order 180 over a period of 12 years. In addition to the source model, a de-aliasing model for atmospheric and oceanic high-frequency variability with augmented systematic and random noise is required for a realistic simulation of the gravity field retrieval process, whose necessary error characteristics are discussed. The documentation is organized as follows: The characteristics of the updated ESM along with some basic validation are presented in Volume 1 of this report (Dobslaw et al., 2014). A detailed comparison to the original ESA ESM (Gruber et al., 2011) is provided in Volume 2 (Bergmann-Wolf et al., 2014), while Volume 3 (Forootan et al., 2014) contains a description of the strategy to derive a realistically noisy de-aliasing model for the high-frequency mass variability in atmosphere and oceans. The files of the updated ESA Earth System Model for gravity mission simulation studies are accessible at DOI:10.5880/GFZ.1.3.2014.001

    Updating ESA's Earth System Model for gravity mission simulation studies: 1. Model description and validation

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    The ability of any satellite gravity mission concept to monitor mass transport processes in the Earth system is typically tested well ahead of its implementation by means of various simulation studies. Those studies often extend from the simulation of realistic orbits and instrumental data all the way down to the retrieval of global gravity field solution time-series. Basic requirement for all these simulations are realistic representations of the spatio-temporal mass variability in the different sub-systems of the Earth, as a source model for the orbit computations. For such simulations, a suitable source model is required to represent (i) high-frequency (i.e., subdaily to weekly) mass variability in the atmosphere and oceans, in order to realistically include the effects of temporal aliasing due to non-tidal high-frequency mass variability into the retrieved gravity fields. In parallel, (ii) low-frequency (i.e., monthly to interannual) variability needs to be modelled with realistic amplitudes, particularly at small spatial scales, in order to assess to what extent a new mission concept might provide further insight into physical processes currently not observable. The new source model documented here attempts to fulfil both requirements: Based on ECMWF’s recent atmospheric reanalysis ERA-Interim and corresponding simulations from numerical models of the other Earth system components, it offers spherical harmonic coefficients of the time-variable global gravity field due to mass variability in atmosphere, oceans, the terrestrial hydrosphere including the ice-sheets and glaciers, as well as the solid Earth. Simulated features range from sub-daily to multiyear periods with a spatial resolution of spherical harmonics degree and order 180 over a period of 12 years. In addition to the source model, a de-aliasing model for atmospheric and oceanic high-frequency variability with augmented systematic and random noise is required for a realistic simulation of the gravity field retrieval process, whose necessary error characteristics are discussed. The documentation of the updated ESA Earth System Model (updated ESM) for gravity mission simulation studies is organized as follows: The characteristics of the updated ESM along with some basic validation is presented in Volume 1. A detailed comparison to the original ESA ESM (Gruber et al., 2011) is provided in Volume 2, while Volume 3 contains the description of a strategy to derive realistic errors for the de-aliasing model of high-frequency mass variability in atmosphere and ocean

    Biofeedback efficacy to improve clinical symptoms and endoscopic signs of solitary rectal ulcer syndrome

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    Solitary rectal ulcer syndrome (SRUS) is often resistant to medical and surgical treatment. This study assessed the effect of biofeedback in decreasing the symptoms and the healing of endoscopic signs in SRUS patients. Before starting the treatment, endoscopy and colorectal manometry was performed to evaluate dyssynergic defecation. Patients were followed every four weeks, and during each visit their response to treatment was evaluated regarding to manometry pattern. After at least 50 improvement in manometry parameters, recipients underwent rectosigmoidoscopy. Endoscopic response to biofeedback treatment and clinical symptoms were investigated. Duration of symptoms was 43.11±36.42 months in responder and 63.9 ± 45.74 months in non-responder group (P=0.22). There were more ulcers in non-responder group than responder group (1.50 ±0.71 versus 1.33±- 0.71 before and 1.30 ± 0.95 versus 0.67 ±0.50 after biofeedback), although the difference was not significant (P=0.604, 0.10 respectively). The most prevalent symptoms were constipation (79), rectal bleeding (68) and anorectal pain (53). The most notable improvement in symptoms after biofeedback occured in abdominal pain and incomplete evacuation, and the least was seen in mucosal discharge and toilet waiting as shown in the bar chart. Endoscopic cure was observed in 4 of 10 patients of the non-responder group while 8 patients in responder group experienced endoscopic improvement. It seems that biofeedback has significant effect for pathophysiologic symptoms such as incomplete evacuation and obstructive defecation. Improvement of clinical symptoms does not mean endoscopic cure; so to demonstrate remission the patients have to go under rectosigmoidoscopy. © PAGEPress 2008-2018

    Multivariate Prediction of Total Water Storage Changes Over West Africa from Multi-Satellite Data

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    West African countries have been exposed to changes in rainfall patterns over the last decades, including a significant negative trend. This causes adverse effects on water resources of the region, for instance, reduced freshwater availability. Assessing and predicting large-scale total water storage (TWS) variations are necessary for West Africa, due to its environmental, social, and economical impacts. Hydrological models, however, may perform poorly over West Africa due to data scarcity. This study describes a new statistical, data-driven approach for predicting West African TWS changes from (past) gravity data obtained from the gravity recovery and climate experiment (GRACE), and (concurrent) rainfall data from the tropical rainfall measuring mission (TRMM) and sea surface temperature (SST) data over the Atlantic, Pacific, and Indian Oceans. The proposed method, therefore, capitalizes on the availability of remotely sensed observations for predicting monthly TWS, a quantity which is hard to observe in the field but important for measuring regional energy balance, as well as for agricultural, and water resource management.Major teleconnections within these data sets were identified using independent component analysis and linked via low-degree autoregressive models to build a predictive framework. After a learning phase of 72 months, our approach predicted TWS from rainfall and SST data alone that fitted to the observed GRACE-TWS better than that from a global hydrological model. Our results indicated a fit of 79 % and 67 % for the first-year prediction of the two dominant annual and inter-annual modes of TWS variations. This fit reduces to 62 % and 57 % for the second year of projection. The proposed approach, therefore, represents strong potential to predict the TWS over West Africa up to 2 years. It also has the potential to bridge the present GRACE data gaps of 1 month about each 162days as well as a—hopefully—limited gap between GRACE and the GRACE follow-on mission over West Africa. The method presented could also be used to generate a near real-time GRACE forecast over the regions that exhibit strong teleconnections

    LA50 in burn injuries Surface létale 50% des patients brûlés

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    Burn injuries put a huge financial burden on patients and healthcare systems. They are the 8th leading cause of mortality and the 13th most common cause of morbidity in our country. We used data from our Burn Registry Program to evaluate risk factors for mortality and lethal area fifty percent (LA50) in all burn patients admitted over two years. We used multiple logistic regressions to identify risk factors for mortality. LA50 is a reliable aggregate index for hospital care quality and a good measure for comparing results, also with those of other countries. 28,690 burn patients sought medical attention in the Emergency Department, and 1721 of them were admitted. Male to female ratio was 1,75:1. 514 patients were under 15 years old. Median age was 25 (range: 3 months � 93 years). Overall, probability of death was 8.4. LA50 was 62.31 (CI 95: 56.57-70.02) for patients aged 15 and over and 72.52 (CI 95: 61.01-100) for those under 15. In the final model, we found that Adjusted OR was significant for age, female sex, TBSA and inhalation injury (P < 0.05). LA50 values showed that children tolerate more extensive burns. Female sex, burn size, age and inhalation injury were the main risk factors for death. Authorities should pay special attention to these variables, especially in prevention programs, to reduce mortality and improve patient outcome. Children have better outcome than adults given equal burn size. Suicide rates are higher for women than men in our country. © 2016, Mediterranean Club for Burns and Fire Disasters. All rights reserved

    Enhancing civil engineering surveying learning through workshops

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    Abstract: Surveying in an undergraduate civil engineering curriculum needs a substantial amount of hands-on training to obtain adequate learning outcomes. A lecture-only mode of delivery does not provide the adequate surveying skills needed by an engineering student. In 2009, workshops were introduced for the CVEN2000 Civil Engineering Drawing and Surveying unit at Curtin University, Australia, with the aim of offering students hands-on training in surveying to enhance their learning. This study analyzes data collected from 160 students in 2012 and 2013 using confidence limits, correlations, frequency percentage distribution, and principal component analysis to evaluate if the introduced workshops contributed to the enhancement of (1) the students acquiring industry-based skills and (2) the students’ overall learning of engineering surveying, which is a practical-oriented course. Additionally, qualitative analysis fromCurtin’s official eVALUate and examination results were used to verify the findings of the previously mentioned contributions. The results indicate that workshops contributed to the development of the students’ overall learning skills, with the top agreement of the students being critical thinking skills (93.6%), handling problems (96.6%), and correlating theory (97.9%). Qualitative analysis of the 2013 data indicates that 70% of the students agreed that their overall learning skills were enhanced and that the workshop sessions prior to the assessed fieldwork of setting out the horizontal curves enhanced their communication and teamwork skills. Overall, 97.9% of the students were satisfied with the workshops, and 98.9% of the students said that they would recommend them as an effective learning tool to their friends. The main lesson learned from the data presented in this paper is that students were satisfied with the workshops and recognized/perceived them to contribute to the development of the learning attributes they need to acquire

    Elevated tumor and serum levels of the hypoxia-associated protein osteopontin are associated with prognosis for soft tissue sarcoma patients

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    <p>Abstract</p> <p>Background</p> <p>Osteopontin (OPN) overexpression is correlated with a poor prognosis for tumor patients. However, only a few studies investigated the prognostic impact of expression of OPN in soft tissue sarcomas (STS) yet.</p> <p>Methods</p> <p>This study is based on tumor and serum samples from 93 adult STS patients. We investigated OPN protein levels in serum (n = 86) and tumor tissue (n = 80) by ELISA and OPN mRNA levels in tumor tissue (n = 68) by quantitative real-time PCR.</p> <p>Results</p> <p>No correlation was found between OPN levels in serum and tumor tissue. Moreover, an elevated OPN protein level in the serum was significantly associated with clinical parameters such as higher stage (p = 0.004), higher grade (p = 0.003), subtype (p = 0.002) and larger tumor size (p = 0.03). OPN protein levels in the tumor tissue were associated with higher stage (p = 0.06), higher grade (p = 0.003), subtype (p = 0.07) and an increased rate of relapse (p = 0.02). In addition, using a Cox's proportional hazards regression model, we found that an elevated OPN protein level in the serum and tumor tissue extracts is a significant negative prognostic factor for patients with STS. The relative risks of tumor-related death were 2.2 (p < 0.05) and 3.7 (p = 0.01), respectively.</p> <p>Conclusion</p> <p>Our data suggest OPN protein in serum as well as in tumor tissue extracts is an important prognostic factor for soft tissue sarcoma patients.</p

    Prostate cancer cells modulate osteoblast mineralisation and osteoclast differentiation through Id-1

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    Background: Id-1 is overexpressed in and correlated with metastatic potential of prostate cancer. The role of Id-1 in this metastatic process was further analysed. Methods: Conditioned media from prostate cancer cells, expressing various levels of Id-1, were used to stimulate pre-osteoclast differentiation and osteoblast mineralisation. Downstream effectors of Id-1 were identified. Expressions of Id-1 and its downstream effectors in prostate cancers were studied using immunohistochemistry in a prostate cancer patient cohort (N110). Results: We found that conditioned media from LNCaP prostate cancer cells overexpressing Id-1 had a higher ability to drive osteoclast differentiation and a lower ability to stimulate osteoblast mineralisation than control, whereas conditioned media from PC3 prostate cancer cells with Id-1 knockdown were less able to stimulate osteoclast differentiation. Id-1 was found to negatively regulate TNF-Β and this correlation was confirmed in human prostate cancer specimens (P0.03). Furthermore, addition of recombinant TNF-Β to LNCaP Id-1 cell-derived media blocked the effect of Id-1 overexpression on osteoblast mineralisation. Conclusion: In prostate cancer cells, the ability of Id-1 to modulate bone cell differentiation favouring metastatic bone disease is partially mediated by TNF-Β, and Id-1 could be a potential therapeutic target for prostate cancer to bone metastasis. © 2010 Cancer Research UK. All rights reserved.link_to_OA_fulltex
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