ASSESSMENT OF STATISTICAL SIGNIFICANCE OF HISTORIC DANUBE FLOODS

2020 ◽  
Author(s):  
Stevan Prohaska ◽  
◽  
Aleksandra Ilić ◽  
Pavla Pekarova ◽  
◽  
...  
Keyword(s):  
Middle Ages ◽  
Linear Trend ◽  
Statistical Significance ◽  
Danube River ◽  
Exceedance Probability ◽  
Simultaneous Occurrence ◽  
Flood Wave ◽  
Probability Of Occurrence ◽  
Comprehensive Method ◽  
Flood Hydrograph

Data on historic floods along the Danube River exist since the year 1012. In the Middle Ages, floods were estimated based on historical documents, including original handwritten notes, newspaper articles, chronicles, formal letters, books, maps and photographs. From 1500 until the beginning of organized water regime observations, floods were hydraulically reconstructed based on water marks on old buildings in cities along the Danube (Passau, Melk, Emmersdorf an der Donau, Spilz, Schonbuhen and Bratislava). The paper presents a procedure for assessing the statistical significance of registered historic floods using a comprehensive method for defining theoretical flood hydrographs at hydrological stations. The approach is based on correlation analysis of two basic flood hydrograph parameters – maximum hydrograph ordinate (peak) and flood wave volume. The PROIL model is used to define the probability of simultaneous occurrence of these parameters. It defines the exceedance probability of two random variables, in the specific case two hydrograph parameters of the form: P{Qmax more equal to qmax,p)∩(Wmax more equal to wmax,p)} = P (1) where: Qmax – maximum hydrograph ordinate (peak); qmax,p – maximum discharge of the probability of occurrence p; Wmax – maximum hydrograph volume; wmax,p – maximum flood wave volume of the probability of occurrence p; P – exceedance probability. Spatial positions of the lines of exceedance of two flood hydrograph parameters and the empirical points of the corresponding parameters of the considered historic flood in the correlation field Qmax - Wmax, allow direct assessment of the exceedance probability of a historic flood, or its statistical significance. The proposed procedure was applied in practice to assess the statistical significance of the biggest floods registered along the Danube in the sector from its mouth to the Djerdap 1 Dam. The linear trend in the time-series of maximum annual flows at a representative hydrological station and the frequency of historic floods in the considered sector of the Danube are discussed at the end of the paper.

scholarly journals Linear trend in patients with ovarian cancer in period 2001-2008 at Oncology Institute of Vojvodina

2010 ◽  
Vol 63 (9-10) ◽  
pp. 607-610 ◽  
Author(s):  
Goran Malenkovic ◽  
Tihomir Dugandzija ◽  
Aljosa Mandic ◽  
Marija Velaga ◽  
Olivera Tesic ◽  
...  
Keyword(s):  
Ovarian Cancer ◽  
Ovarian Carcinoma ◽  
Linear Trend ◽  
Statistical Significance ◽  
Positive Family History ◽  
High Sensitivity ◽  
Diagnostic Procedures ◽  
Malignant Neoplasms ◽  
Female Population ◽  
Advanced Stages

Introduction. Ovarian cancer is one of the leading health problems, as it is the underlying cause of disease and deaths of a large number of women around the world. Postmenopausal female population, in whom ovarian carcinoma is most often diagnosed in advanced stages of the disease, is primarily affected. Material and methods. We used data from Hospital Registry for Malignant Neoplasms at Oncology Institute of Vojvodina, for the period from 2001 to 2008, according to which 422 cases of ovarian carcinoma were reported. The obtained data were classified into three groups according to FIGO classification of ovarian malignant neoplasms. The statistical assessment of data employed the method of linear trend and tests of statistical significance (t-test). Results. The results of our study showed that most cases of diagnosed disease were advanced forms of ovarian cancer, FIGO stages II and IV. The linear trend of the reported cases in stage I for the period 2001/2008 showed a descending trend. According to the processed data, in the same period of time, stage II showed an ascending trend, while stages III and IV described together showed a moderate ascending linear trend. Conclusion. A vast majority of cases of ovarian cancer are detected in advanced stages of the disease, which is at the same time the group with the worst prognosis. Special attention should be paid to the group of patients with positive family history, as well as the presence of BRCA1 and BRCA 2 genetic mutations. Currently existing diagnostic procedures have not given good results individually in terms of high sensitivity for diagnosis of early stages.

scholarly journals Long-term phenoclimatic averages of the Yuganskiy Nature Reserve territory and changes for 1961-2016

2018 ◽  
Vol 9 (2) ◽  
pp. 28-39
Author(s):  
Elena A. Zvyagina ◽  
Tatiana S. Pereyzslovets
Keyword(s):  
Nature Reserve ◽  
Linear Trend ◽  
Statistical Significance ◽  
Precipitation Amount ◽  
Positive Temperature ◽  
Leaf Fall ◽  
Least Squares Regression ◽  
Sap Flux ◽  
Climate Data ◽  
Average Maximum

In light of the observed global climate changes in recent decades, we studied the local climate indicators and explored the possible links between the spring and autumn phenophases and climate data changes in the Yuganskiy nature reserve (N 600 17’; E74054’ – N590 23’; E74000’) in 1982-2016. The collected climate data include daily average, maximum and minimum temperatures, daily precipitation amount and intensity, and number of days with precipitation of 0.1mm or more, monthly average of snow depths, dates of first and last occurrence of daily mean temperatures 0, +5, +10°С through the year. Timing of sap movement and leaf fall start were used as the spring and autumn indicators of birch (Bétula péndula ) phenology. The mean value of weather averages in the 30-year period of 1961-1990 was used as reference. Trends were calculated using linear least squares regression. Statistical significance was determined by calculating the standard error of the trend estimate. We found that the annual mean temperature has increased from –1.9°С (1961-1990) to –0.8° С (1982-2016), with corroborating indicators including increased temperature of the coldest night of the year from –53°С (1961-1990) to –51.3° С (1982-2016) and increased frequency of significant positive temperature anomalies from 21% (1961-1990) to 37% (1982-2016). May, June, August and October nights have become successively warmer. The air temperature increase was not accompanied by a corresponding increase in precipitation. Statistically significant trends toward earlier onset of spring and summer from 1982 to 2016 were observed. The date of the last spring freeze has been advancing by 6.1 days per decade since 1982. A freeze-free season has lengthened by 7.7 days per decade. Linear trend of the snowmelt timing was –3.7 days per decade. Permanent snow cover period has been shortening by 7.7 days per decade. The date of the first occurrence of the daily mean temperatures of +10° С has been advancing by 5.1 days per decade. However, the 0 -+5° С lag has been lengthening significantly by 9.2 days per decade, and the number of biologically effective degree days (base +5C) has not statistically changed. Sap flux and leaf fall timing of B. pendula have been advancing almost simultaneously by 4.0 and 4.2 days per decade since 1985. Sap flux beginning and last spring freeze date have been found to be linearly correlated (r=0.904). The average lag of them was 5±1 days and has been lengthening by 3 days per decade (1985–2016).

Forging Episcopal Identity: Pilgrim at Passau

2021 ◽  
pp. 61-112
Author(s):  
Levi Roach
Keyword(s):  
Middle Ages ◽  
Danube River ◽  
The Danube River ◽  
The Middle Ages

This chapter details how, in 1854, the young Berlin-educated historian Ernst Dümmler made an arresting discovery: most of the early documents concerning the bishopric of Passau had been forged. What is more, these forgeries could be associated with Bishop Pilgrim, who oversaw the Danube River see between 971 and 991. The chapter then briefly surveys Pilgrim's earliest years. Pilgrim identified Passau not only with an earlier bishopric at Lorch, but with a metropolitan past there. The result was one of the most famous forgery complexes of the Middle Ages: a set of false papal privileges and imperial diplomas tracing Passau's history back to this alleged antique (archiepiscopal) past. Like Anno, Pilgrim was providing evidence for rights he and his church had enjoyed, but for which he lacked documentation. Though his forgeries extend into more recent years (at least in the case of the false bulls), as at Worms, the ultimate focus is historical: recent texts are used to buttress the earlier ones, and the diplomas are all placed at a safe remove.

scholarly journals Using satellite measurements of N<sub>2</sub>O to remove dynamical variability from HCl measurements

2018 ◽  
Vol 18 (8) ◽  
pp. 5691-5697 ◽  
Author(s):  
Richard S. Stolarski ◽  
Anne R. Douglass ◽  
Susan E. Strahan
Keyword(s):  
Interannual Variability ◽  
Linear Trend ◽  
Statistical Significance ◽  
Montreal Protocol ◽  
Satellite Measurements ◽  
Simultaneous Measurements ◽  
Slow Decline ◽  
The Impact

Abstract. Column HCl measurements show deviations from the expected slow decline following the regulation of chlorine-containing compounds by the Montreal Protocol. We use the simultaneous measurements of N2O and HCl by the Microwave Limb Sounder (MLS) instrument on the Aura satellite to examine this problem. We find that the use of N2O measurements at a specific altitude to represent the impact of dynamical variability on HCl results in a derived linear trend in HCl that is negative (ranging from −2.5 to 5.3 % decade−1) at all altitudes between 68 and 10 hPa. These trends are at or near 2σ statistical significance at all pressure levels between 68 and 10 hPa. This shows that analysis of simultaneous measurements of several constituents is a useful approach to identify small trends from data records that are strongly influenced by dynamical interannual variability.

scholarly journals Radiocarbon and Stable Isotope Evidence of Dietary Change from the Mesolithic to the Middle Ages in the Iron Gates: New Results from Lepenski Vir

Radiocarbon ◽  
2004 ◽  
Vol 46 (1) ◽  
pp. 293-300 ◽  
Author(s):  
C Bonsall ◽  
G T Cook ◽  
R E M Hedges ◽  
T F G Higham ◽  
C Pickard ◽  
...  
Keyword(s):  
Stable Isotope ◽  
Middle Ages ◽  
Dietary Change ◽  
Danube River ◽  
Southeast Europe ◽  
Reservoir Effect ◽  
Farming Communities ◽  
Dietary Component ◽  
Freshwater Reservoir ◽  
Stable Isotope Study

A previous radiocarbon dating and stable isotope study of directly associated ungulate and human bone samples from Late Mesolithic burials at Schela Cladovei in Romania established that there is a freshwater reservoir effect of approximately 500 yr in the Iron Gates reach of the Danube River valley in southeast Europe. Using the δ15N values as an indicator of the percentage of freshwater protein in the human diet, the 14C data for 24 skeletons from the site of Lepenski Vir were corrected for this reservoir effect. The results of the paired 14C and stable isotope measurements provide evidence of substantial dietary change over the period from about 9000 BP to about 300 BP. The data from the Early Mesolithic to the Chalcolithic are consistent with a 2-component dietary system, where the linear plot of isotopic values reflects mixing between the 2 end-members to differing degrees. Typically, the individuals of Mesolithic age have much heavier δ15N signals and slightly heavier δ13C, while individuals of Early Neolithic and Chalcolithic age have lighter δ15N and δ13C values. Contrary to our earlier suggestion, there is no evidence of a substantial population that had a transitional diet midway between those that were characteristic of the Mesolithic and Neolithic. However, several individuals with “Final Mesolithic” 14C ages show δ15N and δ13C values that are similar to the Neolithic dietary pattern. Provisionally, these are interpreted either as incomers who originated in early farming communities outside the Iron Gates region or as indigenous individuals representing the earliest Neolithic of the Iron Gates. The results from Roman and Medieval age burials show a deviation from the linear function, suggesting the presence of a new major dietary component containing isotopically heavier carbon. This is interpreted as a consequence of the introduction of millet into the human food chain.

Comorbidities and prognosis of myelodysplastic syndromes

2009 ◽  
Vol 27 (15_suppl) ◽  
pp. 7086-7086
Author(s):  
K. Naqvi ◽  
J. Oh ◽  
G. Garcia-Manero ◽  
S. Pierce ◽  
M. E. Suarez-Almazor
Keyword(s):  
Cancer Patients ◽  
Myelodysplastic Syndromes ◽  
Early Stage ◽  
Linear Trend ◽  
Statistical Significance ◽  
Demographic Data ◽  
Comprehensive Cancer Center ◽  
International Prognostic Scoring System ◽  
Cancer Center ◽  
Comorbid Conditions

7086 Background: Cancer patients often experience comorbidities that may affect their therapeutic plan, prognosis, and outcome. Few studies have evaluated comorbidities in myelodysplastic syndromes (MDS). The aim of our study was to determine the effect of comorbidity on the survival of patients with MDS. Methods: We reviewed the medical records of consecutive adult MDS patients who presented to our comprehensive cancer center in 2002. The Adult Comorbidity Evaluation-27 (ACE-27), a validated 27-item comorbidity index for cancer patients, was used to assess the severity of comorbid conditions. For each patient, we obtained demographic data and specific staging information based on the International Prognostic Scoring System (IPSS). We also collected information on bone marrow transplantation (BMT), mortality and survival. Kaplan-Meier methods and log-rank tests were used to assess survival. Results: Of the 55 patients included in this preliminary report, 41 (74.5%) were male, and 47 (85.5%) were white; mean age was 66.4 years; mean follow-up 22.2 months. The three most common comorbidities were hypertension, diabetes mellitus, and coronary artery disease. A total of 90.9% of patients had an IPSS risk of intermediate or higher. The ACE-27 comorbidity scores were as follows: none, 18 patients (32.7%); mild, 17 (30.9%); moderate, 9 (16.4%); and severe, 11 (20.0%). Fifty patients (90.9%) died, whereas 9 (16.4%) underwent BMT. Median survival according to ACE-27 scores was: 22 months for patients with no comorbidity, 11 months for patients with mild or moderate comorbidity, and 8 months for those with severe comorbidity; this trend did not reach statistical significance (p = 0.42). A linear trend was observed between the severity of comorbidity and having received BMT: half of the patients with no comorbidities received BMT compared to none in the group with a severe score (p = 0.02). Conclusions: A small trend was observed between survival and comorbidity. Most of our patients had an advanced IPSS stage which may have decreased the strength of this association. Patients with comorbid conditions received BMT less often than those without comorbidity. Further studies are needed to evaluate the effects of comorbidities on the prognosis and therapeutic options of patients with early-stage MDS. No significant financial relationships to disclose.

scholarly journals A simple approach to providing a more consistent Arctic sea ice extent time series from the 1950s to present

2012 ◽  
Vol 6 (6) ◽  
pp. 1359-1368 ◽  
Author(s):  
W. N. Meier ◽  
J. Stroeve ◽  
A. Barrett ◽  
F. Fetterer
Keyword(s):  
Time Series ◽  
Sea Ice ◽  
Linear Trend ◽  
Statistical Significance ◽  
Recent Decade ◽  
Arctic Sea Ice ◽  
The Arctic ◽  
Sea Ice Extent ◽  
Arctic Sea ◽  
Combined Time Series

Abstract. Observations from passive microwave satellite sensors have provided a continuous and consistent record of sea ice extent since late 1978. Earlier records, compiled from ice charts and other sources exist, but are not consistent with the satellite record. Here, a method is presented to adjust a compilation of pre-satellite sources to remove discontinuities between the two periods and create a more consistent combined 59-yr time series spanning 1953–2011. This adjusted combined time series shows more realistic behavior across the transition between the two individual time series and thus provides higher confidence in trend estimates from 1953 through 2011. The long-term time series is used to calculate linear trend estimates and compare them with trend estimates from the satellite period. The results indicate that trends through the 1960s were largely positive (though not statistically significant) and then turned negative by the mid-1970s and have been consistently negative since, reaching statistical significance (at the 95% confidence level) by the late 1980s. The trend for September (when Arctic extent reaches its seasonal minimum) for the satellite period, 1979–2011 is −12.9% decade−1, nearly double the 1953–2011 trend of −6.8% decade−1 (percent relative to the 1981–2010 mean). The recent decade (2002–2011) stands out as a period of persistent decline in ice extent. The combined 59-yr time series puts the strong observed decline in the Arctic sea ice cover during 1979–2011 in a longer-term context and provides a useful resource for comparisons with historical model estimates.

scholarly journals Statistical significance of rising and oscillatory trends in global ocean and land temperature in the past 160 years

2014 ◽  
Vol 5 (1) ◽  
pp. 327-362 ◽  
Author(s):  
L. Østvand ◽  
K. Rypdal ◽  
M. Rypdal
Keyword(s):  
Global Warming ◽  
Null Hypothesis ◽  
Linear Trend ◽  
Statistical Significance ◽  
General Scheme ◽  
Null Models ◽  
Global Ocean ◽  
Temperature Record ◽  
Trend Model ◽  
Global Land

Abstract. Various interpretations of the notion of a trend in the context of global warming are discussed, contrasting the difference between viewing a trend as the deterministic response to an external forcing and viewing it as a slow variation which can be separated from the background spectral continuum of long-range persistent climate noise. The emphasis in this paper is on the latter notion, and a general scheme is presented for testing a multi-parameter trend model against a null hypothesis which models the observed climate record as an autocorrelated noise. The scheme is employed to the instrumental global sea-surface temperature record and the global land temperature record. A trend model comprising a linear plus an oscillatory trend with period of approximately 70 yr, and the statistical significance of the trends, are tested against three different null models: first-order autoregressive process, fractional Gaussian noise, and fractional Brownian motion. The parameters of the null models are estimated from the instrumental record, but are also checked to be consistent with a Northern Hemisphere temperature reconstruction prior to 1750 for which an anthropogenic trend is negligible. The linear trend in the period 1850–2010 AD is significant in all cases, but the oscillatory trend is insignificant for ocean data and barely significant for land data. However, by using the significance of the linear trend to constrain the null hypothesis, the oscillatory trend in the land record appears to be statistically significant. The results suggest that the global land record may be better suited for detection of the global warming signal than the ocean record.

scholarly journals SCALE AND LONG-TERM DYNAMICS OF OKA RIVER BASIN POLLUTION

2021 ◽  
Vol 26 (2) ◽  
pp. 40-53
Author(s):  
R. G. Dzhamalov ◽  
◽  
K. G. Vlasov ◽  
V. Y. Grigorev ◽  
K. G. Galagur ◽  
...  
Keyword(s):  
Water Quality ◽  
River Basin ◽  
Linear Trend ◽  
Statistical Significance ◽  
Rank Correlation ◽  
Correlation Coefficients ◽  
Kendall Test ◽  
Anthropogenic Load ◽  
Treated Wastewater

Introduction. This article addresses the long-term dynamics of Oka River basin pollution. The basin serves as the main source of drinking water and a receiver of wastewater from a number of regions in European Russia. Methods. We assessed the water quality by 12 main hydrochemical indicators and constructed maps of their distribution with a breakdown into two periods (1990–1999 and 2000–2017). The anthropogenic load along the section in the city of Gorbatov was determined. Spearman’s rank correlation coefficients and their statistical significance were calculated. Results. For 18 gauging stations with 25 and more years of observations, the magnitude of the linear trend (%/year) was estimated using the Theil–Sen estimator, and the statistical significance of the linear trend (Mann–Kendall test) was assessed for individual stations and the entire basin, using a modified Walker test. The runoff of pollutants from the urban territory was estimated between the sections upstream and downstream the cities in the upper reaches of the Oka River basin. The volumes of pollutants in the Oka River from the cities of Orel, Belev and Kaluga were determined for the period of 1990–2017. The calculations of the pollutant runoff, performed between the sections upstream and downstream the cities, made it possible to determine the role of the cities in the formation of point pollution in the upper reaches of the Oka River. The anthropogenic load along the length of the river in terms of the influx of chemicals varies from “low” to “high”. The load is largely due to the intake of pollutants since water bodies and watercourses serve as receivers of both treated and insufficiently treated wastewater from various enterprises. Conclusion. Almost throughout the basin, the water quality is under stress. The statistical analysis showed the existing relationship between a certain type of land use and the concentration of substances in surface waters. It was revealed that the self-cleaning capacity of the river is sufficient to prevent pollutants from accumulating along it.

Optimizing the prophylaxis of hospital-acquired deep vein thrombosis and pulmonary thromboembolism

2016 ◽  
Vol 88 (9) ◽  
pp. 23-30
Author(s):  
G I Nazarenko ◽  
E B Kleymenova ◽  
S A Payushchik ◽  
V A Otdelеnov ◽  
D A Sychev
Keyword(s):  
Linear Trend ◽  
Small Sample Size ◽  
Statistical Significance ◽  
Dynamic Assessment ◽  
Small Sample ◽  
Comprehensive Approach ◽  
Timely Initiation ◽  
Vte Prophylaxis ◽  
Venous Thromboembolic Events ◽  
Hospital Acquired

Aim. To reduce the number of preventable hospital-acquired venous thromboembolic events (HA-VTE) and to improve the quality of VTE prophylaxis at multiprofile hospital. Materials and methods. A comprehensive approach to preventing HA-VTE was developed, which involved the global trigger tool method to assess adverse events, as well as the computerized clinical decision support system (CDSS) to prevent HA-VTE on the basis of relevant clinical practice guidelines, and HA-VTE registry. Results. A total of 50 patients (15 men, 35 women; their median age was 70.5 years) with HA-VTE were included in the HA-VTE registry in January 2014 to June 2015. Assessment of a trend in the prevalence of HA-VTE when introducing CDSS to prevent VTE showed its statistically significant decline in the total number of HA-VTE cases (χ2=7.325, df=1; p=0.0068) and in that of HA-VTE in surgical patients (χ2=7.266, df=1; p=0.0070). The statistical significance of χ2 for linear trend was not achieved for medical patients, which is probably due to the small sample size (χ2=2.764, df=1; p=0.0964). While introducing CDSS, there was a statistically significant reduction in the incidence of postoperative VTE from 8.76 to 4.17 cases per 1000 interventions (χ2=5.347, df=1; p=0.0208; the absolute values of HA-VTE and surgical interventions were used for the calculation). Conclusion. The proposed comprehensive approach can substantially increase the detection rate of HA-VTE and decrease its incidence rates. This requires a personified assessment of the risk of VTE and hemorrhage in all hospitalized patients on day 1 of their admission, timely initiation of recommended VTE prophylaxis, and dynamic assessment of the risk of VTE and hemorrhage for timely correction of the prophylaxis.

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