Relationship between Polynomial Geometric Surfaces Terms and Observation Points Numbers and Effect in the Accuracy of Geometric Geoid Models

International audienceThe application of the geometric method of local geoid model determination which requires the fitting of geometric surfaces to known geoid heights to enable geoid heights of new points to be interpolated involves the use of least squares technique for computation of the models' parameters. The selection of polynomial geometric surfaces depends on the size of the study area, the variation of the geoid heights and the number of measurement points. The accuracy of the geometric geoid model increases as the number of observation points approximates the number of geometric surface terms. But in most cases, the number of observation points is not considered. To this effect, this paper presents the relationship between geometric surfaces terms and observation points numbers and effect in the accuracy of geometric geoid models. A total of 23 points of known local gravimetric geoid heights were used. Two polynomial geometric (third and fifth degrees) surfaces were fitted to the geoid heights at various observation point numbers and compared to determine the relationship between the number of model terms and that of observation points and effect in the accuracy of the models. Least squares adjustment technique was applied to obtain the model parameters. The differences between the models and the known geoid heights of the points were computed and used to obtain the RMSEs as well as the accuracy of the models. The obtained results showed that the accuracy of the polynomial geometric geoid models tends to the highest as the number of measurement points approximates the number of the model terms and in a unique solution where the number of observation points is equal to the number of the polynomial geometric model terms, the model accuracy is highest. The paper recommends that the geometric method of local geoid model determination should be strictly applied in small areas. Where the method will be applied in considerable large areas, higher degrees polynomial geometric surfaces with a larger number of terms approximating the number of observation points should be applied. This will enable a proper fit of the polynomial surface to the known geoid heights, as well as high accuracy to be obtained

Experiences of shame and guilt in anorexia and bulimia nervosa: A systematic review

Objectives Emotional states may play an important role in the development and maintenance of anorexia (AN) and bulimia nervosa (BN). This systematic review aimed to examine the evidence regarding the relationship that shame and guilt have with two eating disorders, AN and BN. Methods Four major databases (Pubmed, PsychINFO, Web of Science, Medline) were searched (up until April 2018) for studies measuring guilt or shame in clinically diagnosed AN and BN groups. Included papers were evaluated for risk of bias. Results Twenty‐four papers met the inclusion criteria. Several methodological issues were noted within the reviewed studies, including a lack of longitudinal data and unaccounted confounding variables. Nonetheless, shame was typically more common in those with AN and BN than controls, was positively related to the severity of symptoms, and associated with the onset of eating disorder‐related difficulties (e.g., binging or purging). Effect sizes were typically moderate to large. The role of guilt was less clear, with few studies and mixed results. Discussion There is preliminary evidence that shame is implicated in the aetiology of AN and BN presentations, whilst there is currently insufficient evidence of such a role for guilt. It remains unclear whether shame is a risk factor for the development of AN and BN or a consequence of these difficulties. Practitioner Points Elevated shame appears to be a feature of anorexia (AN) and bulimia nervosa (BN). Shame appears to fluctuate with the occurrence of eating disordered behaviours like binging, purging or restricted eating. Guilt is less consistently linked to AN and BN presentations. Interventions directed at shame may be helpful for these populations. A lack of longitudinal data means the temporal features of these relationships are still unclear

Computations of Geoid Undulation from Comparison of GNSS/Levelling with EGM 2008 for Geodetic Applications

International audienceConsistency is an important characteristic in height systems which the mean sea level (msl) surface cannot guarantee. Only a geoid surface can provide height consistency. The quality of geoid undulation (N) will obviously affect the resulting orthometric height (H) determined from GNSS. The geoid undulation may be global, regional/national and local. Online software CSRS-PPP was used for post processing rinex data. 2008 was computed from AllTrans EGM2008 geoid calculator while h was used to compute from the relationship N= h-H. H is the existing orthometric height. Twenty-four controls with FCT 260 P as base reference station were used for this study. The computed standard deviation of differences in − 2008 (σ) is used as accuracy indicator and σ =0.419m .The root mean square error (RMSE) is 0.934m. This indicates the quality and reliability of the geoid undulation from the EGM2008 model. Comparing the observed and 2008 , the use of global models may not satisfy the accuracy level of orthometric height desired for local applications in the FCT, Abuja. GNSS (GPS) may be used along with local geoid model as a way to acquire acceptable orthometric height. The smaller the-2008 makes it better model. The range of 1.585m from (-2008) in this study is a strong indication that global models should be avoided as much as possible in local applications

Comparison of Two Polynomial Geoid Models of GNSS/Leveling Geoid Development for Orthometric Heights in FCT, Abuja

International audienceEllipsoidal heights from GNSS require geoid model for conversion to orthometric height. The geoid model could be global, regional or local. The lack of national geoid model in Nigeria makes development of local geoid very critical to local applications in place of integrated global geoid models. This study compares two polynomial geoid models for terrain representation in the FCT, Abuja. Nine coefficients were used to model the FCT surface for geoid interpolation and orthometric height modeling. Model A involved the use of the 2-D (x, y) positions while model B used 3-D (x, y,) where = (-) the difference in average ellipsoidal height () and each point's ellipsoidal height (). The term is based on the assumption that the geoid varies with topography and may hence possibly lead to some improvements in accuracy of orthometric height determination. DGPS observations were carried out to determine ellipsoid heights. Least squares adjustment was performed to compute the coefficients of the models. Model A achieved standard deviation of σ = 11 cm while Model B achieved σ = 13cm. Though, Model B has a term that included highly accurate ellipsoidal height differences (), it has not resulted into any accuracy improvement over the model A. Model A based on 2-D positions is hence the better of the two models. The t-test and hypothesis test at 95% confidence limit, however, showed that the two models did not differ significantly. Model A having lower standard deviation is recommended with GNSS determined ellipsoidal heights to determine orthometric heights within the FCT. This becomes an easy alternative to conventional spirit leveling technique for production of topographical maps, cadastral surveys, and engineering/environmental applications

Procedure for Coordinates Conversion between NTM and UTM Systems in Minna Datum Using All Trans and Columbus Software

International audienceAs the Edo State Branch of the Nigerian Institution of Surveyors (NIS) has decided to align with the agency (Edo Geographic Information Service) that is responsible for the processing of Certificate of Occupancy to be determining positions in the UTM system, the coordinates of the existing controls in the State have to be converted to UTM coordinates using conversion software. Consequently, this paper presents detailed procedures for the application of AllTrans and Columbus software for positions conversion between NTM and UTM systems in Minna datum. The Minna datum properties, as well as the NTM and UTM parameters, have been detailed for effective use. The step by step procedures to consider when applying the software have enumerated. It was recommended that the Edo State branch of the institution (NIS) should get the full and the latest version of the software. It was also recommended that there should be a lecture for the practical demonstration of the detailed procedures

Thidiazuron-induced efficient biosynthesis of phenolic compounds in callus culture of Ipomoea turbinata Lagasca and Segura

International audienceIpomoea turbinata Lagasca and Segura (Purple Moonflower) belongs to the largest flowering genus Ipomoea in the Convolvulaceae family. Ipomoea turbinata has not been previously explored for its in vitro potential. This is the first study focused on thidiazuron-induced callus culture for efficient biosynthesis of commercially important phenolic compounds in this plant species. Among the two plant growth regulators tested on leaf, stem, and root explants, 5 mg L−1 thidiazuron (TDZ) induced the highest biomass accumulation (61.4 g L−1 fresh weight, 6.3 g L−1 dry weight) in leaf-derived callus cultures after 5 wk of culture. The highest total phenolic and flavonoid contents recorded were 9.04 mg g−1 and 1.16 mg g−1, respectively, in optimized callus cultures. High-performance liquid chromatography analysis indicated high levels of pharmacologically important anticancer compounds such as chlorogenic acid (13.48 mg g−1), arctigenin (11.67 mg g−1), quercetin (6.19 mg g−1), and kaempferol (5.48 mg g−1), along with other phenolic acids. Furthermore, the antioxidant activity was also evaluated, and leaf-derived callus culture displayed a maximum of 62.6% antioxidant potential. The induction of improved biomass accumulation in callus culture and the production of multipotent bioactive metabolites shows the potential of the multifunctional thidiazuron hormone as an efficient elicitation tool in callus culture of I. turbinata

Evaluation of a quality improvement intervention to reduce anastomotic leak following right colectomy (EAGLE): pragmatic, batched stepped-wedge, cluster-randomized trial in 64 countries

Background: Anastomotic leak affects 8 per cent of patients after right colectomy with a 10-fold increased risk of postoperative death. The EAGLE study aimed to develop and test whether an international, standardized quality improvement intervention could reduce anastomotic leaks. Methods: The internationally intended protocol, iteratively co-developed by a multistage Delphi process, comprised an online educational module introducing risk stratification, an intraoperative checklist, and harmonized surgical techniques. Clusters (hospital teams) were randomized to one of three arms with varied sequences of intervention/data collection by a derived stepped-wedge batch design (at least 18 hospital teams per batch). Patients were blinded to the study allocation. Low- and middle-income country enrolment was encouraged. The primary outcome (assessed by intention to treat) was anastomotic leak rate, and subgroup analyses by module completion (at least 80 per cent of surgeons, high engagement; less than 50 per cent, low engagement) were preplanned. Results: A total 355 hospital teams registered, with 332 from 64 countries (39.2 per cent low and middle income) included in the final analysis. The online modules were completed by half of the surgeons (2143 of 4411). The primary analysis included 3039 of the 3268 patients recruited (206 patients had no anastomosis and 23 were lost to follow-up), with anastomotic leaks arising before and after the intervention in 10.1 and 9.6 per cent respectively (adjusted OR 0.87, 95 per cent c.i. 0.59 to 1.30; P = 0.498). The proportion of surgeons completing the educational modules was an influence: the leak rate decreased from 12.2 per cent (61 of 500) before intervention to 5.1 per cent (24 of 473) after intervention in high-engagement centres (adjusted OR 0.36, 0.20 to 0.64; P < 0.001), but this was not observed in low-engagement hospitals (8.3 per cent (59 of 714) and 13.8 per cent (61 of 443) respectively; adjusted OR 2.09, 1.31 to 3.31). Conclusion: Completion of globally available digital training by engaged teams can alter anastomotic leak rates. Registration number: NCT04270721 (http://www.clinicaltrials.gov)

Evaluation of a quality improvement intervention to reduce anastomotic leak following right colectomy (EAGLE): pragmatic, batched stepped-wedge, cluster-randomized trial in 64 countries

Background Anastomotic leak affects 8 per cent of patients after right colectomy with a 10-fold increased risk of postoperative death. The EAGLE study aimed to develop and test whether an international, standardized quality improvement intervention could reduce anastomotic leaks. Methods The internationally intended protocol, iteratively co-developed by a multistage Delphi process, comprised an online educational module introducing risk stratification, an intraoperative checklist, and harmonized surgical techniques. Clusters (hospital teams) were randomized to one of three arms with varied sequences of intervention/data collection by a derived stepped-wedge batch design (at least 18 hospital teams per batch). Patients were blinded to the study allocation. Low- and middle-income country enrolment was encouraged. The primary outcome (assessed by intention to treat) was anastomotic leak rate, and subgroup analyses by module completion (at least 80 per cent of surgeons, high engagement; less than 50 per cent, low engagement) were preplanned. Results A total 355 hospital teams registered, with 332 from 64 countries (39.2 per cent low and middle income) included in the final analysis. The online modules were completed by half of the surgeons (2143 of 4411). The primary analysis included 3039 of the 3268 patients recruited (206 patients had no anastomosis and 23 were lost to follow-up), with anastomotic leaks arising before and after the intervention in 10.1 and 9.6 per cent respectively (adjusted OR 0.87, 95 per cent c.i. 0.59 to 1.30; P = 0.498). The proportion of surgeons completing the educational modules was an influence: the leak rate decreased from 12.2 per cent (61 of 500) before intervention to 5.1 per cent (24 of 473) after intervention in high-engagement centres (adjusted OR 0.36, 0.20 to 0.64; P &lt; 0.001), but this was not observed in low-engagement hospitals (8.3 per cent (59 of 714) and 13.8 per cent (61 of 443) respectively; adjusted OR 2.09, 1.31 to 3.31). Conclusion Completion of globally available digital training by engaged teams can alter anastomotic leak rates. Registration number: NCT04270721 (http://www.clinicaltrials.gov)