scholarly journals On the Stationarity of Annual Precipitation over China (1959–2018)

2020 ◽  
Vol 21 (5) ◽  
pp. 881-890 ◽  
Author(s):  
Hong Wang ◽  
Fubao Sun
Keyword(s):  
Water Resource ◽  
Resource Planning ◽  
Annual Precipitation ◽  
Observation Data ◽  
Grid Cells ◽  
The Past ◽  
Significant Difference ◽  
Average Variation ◽  
Long Term Observation

AbstractStationarity is an assumption that permeates training and practice in water-resource engineering. However, with global change, the validity of stationarity as well as uncertainty of nonstationarity in water-resource planning are being questioned; thus, it is critical to evaluate the stationarity of climate variables, especially precipitation. Based on the continuous observation data of precipitation from 1427 stations across China, 593 efficient grid cells (1° × 1°) are constructed, and the annual precipitation stationarities from 1959 to 2018 are analyzed. The evaluated autocorrelation stationarity indicates that 92.24%–96.12% of the grid cells for an autocorrelation coefficient of lag 1–8 years of precipitation are indistinguishable from 0 [90% confidence level (CL)]. The mean stationarity indicates that 97.47% of the grid cells have a stable mean for 30 years (90% CL); beyond the confidence limits, they are mainly located in the northwest of China, where annual precipitation is less, and the average exceeding range is ±3.78 mm. The long-term observation of annual precipitation in Beijing (1819–2018) and Shanghai (1879–2018) also yields autocorrelation and mean stationarities. There is no significant difference in the annual precipitations between the past 20 years (1999–2018) and the past 60 years (1959–2018) over China. Therefore, the annual precipitation in China exhibits a weak stationary behavior that is indistinguishable from the stationary stochastic process. The average variation in precipitation is ±9.55% between 30 successive years and 16.53% between 10 successive years. Therefore, it is valuable and feasible to utilize the historical data of annual precipitation as the basis of water-resources application.

scholarly journals Bird trends from long-term observation data at sites in the Hudson Bay Lowlands

2021 ◽  
Vol 16 (1) ◽  
Author(s):  
Rodney W. Brook ◽  
Lisa A. Pollock ◽  
Kenneth F. Abraham ◽  
Glen S. Brown
Keyword(s):  
Hudson Bay ◽  
Observation Data ◽  
Hudson Bay Lowlands ◽  
Long Term Observation

Bias Correction of Gauge Data and its Effect on Precipitation Climatology over Mainland China

2019 ◽  
Vol 58 (10) ◽  
pp. 2177-2196 ◽  
Author(s):  
Yingxian Zhang ◽  
Yuyu Ren ◽  
Guoyu Ren ◽  
Guofu Wang
Keyword(s):  
Bias Correction ◽  
Arid Regions ◽  
Mainland China ◽  
Rain Gauge ◽  
Precipitation Intensity ◽  
Annual Precipitation ◽  
National Network ◽  
The Past ◽  
Precipitation Records

AbstractTypical rain gauge measurements have long been recognized to underestimate actual precipitation. Long-term daily precipitation records during 1961–2013 from a dense national network of 2379 gauges were corrected to remove systematic errors caused by trace precipitation, wetting losses, and wind-induced undercatch. The corrected percentage was higher in cold seasons and lower in warm seasons. Both trace precipitation and wetting loss corrections were more important in arid regions than in wet regions. A greater correction percentage for wind-induced error could be found in cold and arid regions, as well as high wind speed areas. Generally, the annual precipitation amounts as well as the annual precipitation intensity increased to varying degrees after bias correction with the maximum percentage being about 35%. More importantly, the bias-corrected snowfall amount as well as the rainstorm amount increased remarkably by percentages of more than 50% and 18%, respectively. Remarkably, the total number of actual rainstorm events during the past 53 years could be 90 days more than the observed rainstorm events in some coastal areas of China. Therefore, the actual amounts of precipitation, snowfall, and intense rainfall were much higher than previously measured over China. Bias correction is thus needed to obtain accurate estimates of precipitation amounts and precipitation intensity.

Evolution of pancreatic cancer survival over the past two decades.

2017 ◽  
Vol 35 (15_suppl) ◽  
pp. e15722-e15722
Author(s):  
Veronica Mariotti ◽  
Ricardo Daniel Parrondo ◽  
Miguel Gonzalez Velez ◽  
Narjust Duma ◽  
Lori Ann Leslie ◽  
...  
Keyword(s):  
Pancreatic Cancer ◽  
Cancer Survival ◽  
Single Agent ◽  
Surgical Techniques ◽  
Pancreatic Head ◽  
Age At Diagnosis ◽  
Cancer Center ◽  
The Past ◽  
Significant Difference

e15722 Background: Pancreatic cancer (PaCa) is a highly lethal disease, with a 5-year overall survival (OS) rate of approximately 6%, and a median OS of only 3–6 months (m). Despite recent improvements in surgical techniques and increased use of combination chemotherapy (CT), OS remains poor. This study aims to examine the factors that led to increased OS in PaCa patients (pts) over the past two decades in a single academic institution. Methods: All medical records of pts diagnosed with PaCa at the John Theurer Cancer Center from 1990 to 2012 were reviewed, and 916 PaCa pts were included in this analysis. We compared one group of pts diagnosed from 1990 to 2003 (G1, n = 482), with a group of pts diagnosed from 2004 to 2012 (G2, n = 434) in terms of OS, demographics, tumor features and treatment (tx). Results: Median age at diagnosis was 70.5 years (range 26-96). There was no significant difference between G1 and G2 in terms of age at diagnosis, stage of disease and number of pts who received surgery. A significantly higher percentage of pts received CT in G2 compared to G1 (66.5% vs 51.0%, p = .00). Tumors of the pancreatic head were more common in G1 compared to G2 (51.8% vs 44.4% p = .02). More pts in G2 received two or more CT agents compared to G1 (49.0% vs 34.1%, p = .00). Median OS was significantly longer in G2 compared to G1 (9m vs 5m, p = .00), in pts who received CT compared to pts who did not (3m vs 9m, p = .00) and in pts who received surgery compared to pts who did not (5m vs 19m, p = .00). Pancreatic head location was associated with improved OS compared to other locations (9m vs 5m, p = .00). No OS difference was found between pts who received combination with two or more agents vs single agent CT. Conclusions: In line with multiple studies, analysis of PaCa data from our institution showed an increase OS in pts diagnosed with PaCa in more recent years, and in those who received surgery and CT. CT was administered in a larger number of pts in G2, which might account for the better OS in this group. Pts diagnosed with tumors of the pancreatic head had better survival, which could be explained by earlier presentation leading to earlier diagnosis and tx. Further research in PaCa therapeutics is needed, as long-term OS in PaCa pts remains poor despite recent advances.

scholarly journals Long-term evaluation of the molar movements following Pendulum and fixed appliances

2012 ◽  
Vol 83 (3) ◽  
pp. 447-454 ◽  
Author(s):  
Alberto Caprioglio ◽  
Mattia Fontana ◽  
Elena Longoni ◽  
Mauro Cozzani
Keyword(s):  
Class Ii ◽  
Individual Growth ◽  
Fixed Appliance ◽  
Skeletal Changes ◽  
Growth Increase ◽  
Lateral Cephalograms ◽  
Significant Difference ◽  
Term Evaluation ◽  
Long Term Observation

ABSTRACT Objective: To describe the molar movements and skeletal changes associated with Pendulum-fixed appliance treatment and the long-term postretention period. Subjects and Methods: The treatment sample consisted of 76 Class II patients, 35 males and 41 females. Lateral cephalograms were obtained at the start of treatment (T1); the end of distalization (T2); the end of orthodontic fixed appliance therapy (T3); and long-term observation (7 years 2 months later; T4). Mean age was 12 years 11 months at T1, 13 years 8 months at T2, 15 years 4 months at T3, and 22 years 5 months at T4. The average amount of Class II molar relationship was 3.1 mm, with a mean overjet of 5.9 mm at the beginning of treatment. A paired t-test was used to identify significant between-group differences between T2–T4 and T3–T4. Results: Distal molar movement was obtained during the distalization phase (T2), and more than half of the distalizing effect was maintained at the end of maxillary growth (T4). Most of the relapse occurred during fixed appliance therapy (T3), whereas no significant change was detected in the postretention period (T4). The molar relationship did not show any significant difference between T2 and T4. The vertical facial dimension increased during the distalization phase (T2) and fixed appliance therapy (T3) but returned to the initial values during the postretention period (T4). Conclusions: The Pendulum appliance induces significant dentoalveolar effects, which can be partially maintained during the long-term period. The Class I molar relationship does not change during completion of individual growth. Increase in vertical facial dimension represents a temporary effect.

scholarly journals Porovnanie vývoja vybraných jedľobukových porastov vo výskumno-účelovom objekte „Komárnik"

2013 ◽  
Vol 59 (4) ◽  
pp. 229-239
Author(s):  
Igor Štefančík ◽  
Jozef Pajtík ◽  
Michal Bošeľa ◽  
Tibor Priwitzer ◽  
Vladimír Čaboun ◽  
...  
Keyword(s):  
Dead Wood ◽  
Control Area ◽  
Nature Management ◽  
Above Ground Biomass ◽  
Natural Conditions ◽  
Horizontal Structure ◽  
The Past ◽  
Long Term Observation ◽  
Production Characteristics

AbstractThe paper presents results of a long-term observation focused on the growth of two selected fir-beech stands in the area of the Eastern Carpathian Mountains, which were established in the past to investigate the effect of different management treatments on the growth and structure of the stands. Attention was paid to changes in the tree species proportion, vertical and horizontal structure, the quantitative production and dead wood. The results of the monitoring of approximately 60-year stands development suggested a reduction of the fir proportion and an increase proportion of beech and maple in the natural conditions. Production characteristics (wood stock, above ground biomass, carbon stock, and dead wood) have reached higher values on the control area. The results suggested that the close-to-nature management of these forest stands has a beneficial effect on their structure and overall development.

scholarly journals Changes in forms of available nitrogen and respiration in soil of beech forest as a reaction to a deforestation resulting from wind storm

2013 ◽  
Vol 61 (1) ◽  
pp. 107-113 ◽  
Author(s):  
Aleš Kučera ◽  
Ladislav Holík ◽  
Karel Marosz ◽  
Antonín Martiník ◽  
Dušan Vavříček
Keyword(s):  
Beech Forest ◽  
Nitrate Content ◽  
Available Nitrogen ◽  
Respiration Activity ◽  
Ammonium N ◽  
Significant Difference ◽  
The One ◽  
Long Term Observation ◽  
A Site

The article deals with the reaction of soil environment to a violent deforestation resulting from a wind storm. As a material, permanent inventory plot located in Training Forest Enterprise Masaryk Forest Křtiny was selected. The plot represents beech high forest, where soil was sampled from four types of sample plots: (1) maternal forest representing situation before the storm; (2) zone of transition from the maternal forest to the open area; (3) reafforested clearing; (4) natural evolution. From each sample plot type, 6 mixed samples of Ah horizon were analysed to assess N-ammonium (N-NH4+) and N-nitrates (NO3−) content and respiration activity. The results show a significant difference between the respiration activities of the particular sample plots, as well as a significant difference in the content of N-ammonium and N-nitrate forms, the maternal forest representing a site of the lowest biological (and respiration) activity on the one hand, and, on the other hand, site of high N-ammonium and low N-nitrate content, respectively. From the results, intensive nitrification caused by the deforestation is evident. The results are to be used as a starting level for a long-term observation of reaction of the forest beech ecosystem to deforestation and selected types of forest management.

An Evaluation of Statewide Forest Resource Planning in the Northeast1

1989 ◽  
Vol 6 (1) ◽  
pp. 6-9 ◽  
Author(s):  
Gerald J. Gray ◽  
Paul V. Ellefson
Keyword(s):  
First Generation ◽  
Resource Planning ◽  
Forest Resources ◽  
Forest Resource ◽  
The Past ◽  
Generation Planning ◽  
State Forestry ◽  
Communication And Coordination ◽  
Program Awareness

Abstract Over the past decade, 18 of the 20 northeastern states have undertaken statewide forest resource planning programs. These programs were intended to address the use and management of forest resources on nonfederal lands. Despite significant federal and state investments in such programs, little is known about their effectiveness. These first-generation planning programs were generally perceived to have been well conceived and to have provided many benefits to state forestry organizations and forestry communities at large. The greatest benefits to states in the Northeast were increased communication and coordination among forestry organizations, and a clearer sense of long-term direction. The study concludes that statewise forest resource planning can build greater support and be more effective by increasing program awareness and demonstrating planning's value to a wider range of constituents. North. J. Appl. For. 6:6-9, March 1989.

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