Classification and Causes Identification of Chinese Civil Aviation Incident Reports

Safety is a primary concern for the civil aviation industry. Airlines record high-frequency but potentially low-severity unsafe events, i.e., incidents, in their reports. Over the past few decades, civil aviation security practitioners have made efforts to analyze these issues. The information in incident reports is valuable for risk analysis. However, incident reports were inefficiently utilized due to incoherence, large volume, and poor structure. In this study, we proposed a technical scheme to intelligently classify and extract risk factors from Chinese civil aviation incident reports. Firstly, we adopted machine learning classifiers and vectorization strategies to classify incident reports into 11 categories. Grid search was used to adjust the parameters of the classifier. In the preliminary experiment, the combination of the extreme gradient boosting (XGBoost) classifier and the occurrence position (OC-POS) vectorization strategy outperformed with an 0.85 weighted F1-score. In addition, we designed a rule-based system to identify the factors related to the occurrence of incidents from 25 empirical causes, which included equipment, human, environment, and organizational causes. For cause identification, we used rules obtained through manual analysis with keywords and discourse. F1-score above 0.90 was obtained on the test set using the causes identification model derived from the training set. The proposed system permits insights into unsafe factors in aviation incidents and prevents reoccurrence. Future works can proceed on this study, such as exploring the causal relationship between causes and incidents

Retroperitoneal laparoscopic debridement and drainage of infected retroperitoneal necrosis in severe acute pancreatitis

To explore the effect of retroperitoneal laparoscopic debridement and drainage on infected necrosis in severe acute pancreatitis. This retrospective study included 18 patients with severe acute pancreatitis (SAP) undergoing retroperitoneal laparoscopic debridement and drainage from May 2006 to April 2012 in our hospital. All patients had infected retroperitoneal necrosis and single or multiple peritoneal abscesses. Eleven patients transferred to our hospital were treated with the retroperitoneal laparoscopic debridement and drainage within 24–72 hours after admission. Conservative treatments were given to eight patients. Retroperitoneal laparoscopic debridement and drainage were applied 3–11 days after admission. All patients had infection of necrotic pancreas or peripancreatic tissues. Twelve patients had organ failure. Three patients underwent secondary surgery. Laparotomy with debridement and drainage were applied to one patient who had a huge lesser sac abscess 7 days after first surgery. The other two patients were given secondary retroperitoneal laparoscopic debridement and drainage. One case was complicated by retroperitoneal hemorrhage, four cases had pancreatic leakage, and no intestinal fistula was found. The patients' heart rate, respiration, temperature, and white blood cell count were significantly improved 48 hours after surgery compared with those prior to surgery (

Retroperitoneal laparoscopic debridement and drainage of infected retroperitoneal necrosis in severe acute pancreatitis

Objective: To explore the effect of retroperitoneal laparoscopic debridement and drainage on infected necrosis in severe acute pancreatitis. Materials and methods: This retrospective study included 18 patients with severe acute pancreatitis (SAP) undergoing retroperitoneal laparoscopic debridement and drainage from May 2006 to April 2012 in our hospital. All patients had infected retroperitoneal necrosis and single or multiple peritoneal abscesses. Eleven patients transferred to our hospital were treated with the retroperitoneal laparoscopic debridement and drainage within 24–72 hours after admission. Conservative treatments were given to eight patients. Retroperitoneal laparoscopic debridement and drainage were applied 3–11 days after admission. Results: All patients had infection of necrotic pancreas or peripancreatic tissues. Twelve patients had organ failure. Three patients underwent secondary surgery. Laparotomy with debridement and drainage were applied to one patient who had a huge lesser sac abscess 7 days after first surgery. The other two patients were given secondary retroperitoneal laparoscopic debridement and drainage. One case was complicated by retroperitoneal hemorrhage, four cases had pancreatic leakage, and no intestinal fistula was found. The patients' heart rate, respiration, temperature, and white blood cell count were significantly improved 48 hours after surgery compared with those prior to surgery (p<0.05). The average length of stay in hospitals was 40.8 days (range, 6–121 days), and the drainage tube indwelling time was 44.4 days (range, 2–182 days). Conclusion: Retroperitoneal laparoscopic debridement and drainage is an SAP surgical treatment with a minimally invasive procedure and a good effect, and can be applied for infected retroperitoneal necrosis in early SAP

Clustering of 22 Siberian apricot populations.

<p>Each individual is shown as a vertical line divided into segments representing the estimated membership proportion in the four, seven, ten and fourteen ancestral genetic clusters inferred with STRUCTURE.</p

Analysis of molecular variance from microsatellite data using Arlequin version 3.5.

<p>The hierarchical analysis included 22 sampling populations in China including within populations, among populations within groups and among groups.</p>a<p>The first analysis included all populations as one hierarchical group.</p>b<p>The second analysis included two different origin groups.</p>c<p>The third analysis included six geographical groups.</p>d<p>The fourth analysis included four genetic clusters.</p>e<p>The fifth analysis included seven genetic subclusters.</p>f<p>The fifth analysis included ten genetic subclusters.</p>g<p>The fifth analysis included fourteen genetic subclustersF_ST variance among coefficient of individual relative to the total variance.</p><p>F_SC variance among subpopulations within groups.</p><p>F_CT variance among groups relative to the total variance.</p

Genetic barriers predicted by BARRIER (version 2.2).

<p>The genetic barriers are shown in bold lines with arrows. A: genetic barrier predication using all populations; B: genetic barrier predication using all wild populations.</p

Summary of Siberian apricot sampling locations around China.

<p>Summary of Siberian apricot sampling locations around China.</p

High-Level Genetic Diversity and Complex Population Structure of Siberian Apricot (<i>Prunus sibirica</i> L.) in China as Revealed by Nuclear SSR Markers

<div><p>Siberian apricot (<i>Prunus sibirica</i> L.), an ecologically and economically important tree species with a high degree of tolerance to a variety of extreme environmental conditions, is widely distributed across the mountains of northeastern and northern China, eastern and southeastern regions of Mongolia, Eastern Siberia, and the Maritime Territory of Russia. However, few studies have examined the genetic diversity and population structure of this species. Using 31 nuclear microsatellites, we investigated the level of genetic diversity and population structure of Siberian apricot sampled from 22 populations across China. The number of alleles per locus ranged from 5 to 33, with an average of 19.323 alleles. The observed heterozygosity and expected heterozygosity ranged from 0.037 to 0.874 and 0.040 to 0.924 with average values of 0.639 and 0.774, respectively. A STRUCTURE-based analysis clustered all of the populations into four genetic clusters. Significant genetic differentiation was observed between all population pairs. A hierarchical analysis of molecular variance attributed about 94% of the variation to within populations. No significant difference was detected between the wild and semi-wild groups, indicating that recent cultivation practices have had little impact on the genetic diversity of Siberian apricot. The Mantel test showed that the genetic distance among the populations was not significantly correlated with geographic distance (r = 0.4651, p = 0.9940). Our study represents the most comprehensive investigation of the genetic diversity and population structure of Siberian apricot in China to date, and it provides valuable information for the collection of genetic resources for the breeding of Siberian apricot and related species.</p></div

Plot of the Ln P(D) ± SD and delta K (ΔK).

<p>The mean of Ln P(D) was based on ten repetitions for each K value.</p

Correlation between genetic distance and geographic distance for Siberian apricot populations.

<p>Genetic distance is represented by pairwise F_ST/(1–F_ST) estimates among populations, which is regressed against the geographic distance. The RMA regression line overlays the scatterplot.</p