Robust Method for the Detection of Abnormal Data in Hydrography

Blunder detection is a topic of great interest to hydrographers because undetected blunders significantly distort the observed parameters, e.g., soundings. Based on an analysis of the characteristic of marine surveying, a robust method for the detection of abnormal data (include blunders) in hydrography is proposed in this paper, which is called the robust interpolation comparison test based on robust Mestimation by an iterative calculation procedure. Some questions involved in the implement of the suggested method are discussed in detail. Compared to the existing methods, the new method has more strong capacity of locating abnormal data. A simulation study and an actual numerical example for the process of multibeam soundings are given to test the performance of the proposed method. The results have illustrated the effectiveness of the method in the detection and identification of multiple blunders. The use of the new method will play an important role in improving the quality and reliability of marine measurements in our country

The Influence of Carrier's Attitude and the Position Reduction in Multibeam Echosounding and Airborne Laser Depth Sounding

Having finished the development of the multibeam echosounding system, China is making a great effort to develop an airborne laser depth sounding system. According to the principle of the two kinds of sounding system mentioned above, a series of position reduction formulas and their error equations are developed in this paper. The dynamic effect of marine sounding, i.e., the influence of carrier's attitude, is taken into full account in developing the equations. Finally, the real parameters of the two sounding systems developed by China are used to calculate the position reductions and their accuracies at different heading angles. The results show that the accuracies of depths and positions in multibeam echosounding and airborne laser depth sounding are dependent not only on their own sensors but also on the additional sensors

Association of Intraoperative Hypotension with Acute Kidney Injury after Noncardiac Surgery in Patients Younger than 60 Years Old

Background/Aims: Intraoperative hypotension (IOH) may be associated with surgery-related acute kidney injury (AKI). However, the duration of hypotension that triggers AKI is poorly understood. The incidence of AKI with various durations of IOH and mean arterial pressures (MAPs) was investigated. Materials: A retrospective cohort study of 4,952 patients undergoing noncardiac surgery (2011 to 2016) with MAP monitoring and a length of stay of one or more days was performed. The exclusion criteria were a preoperative estimated glomerular filtration (eGFR) ≤60 mL min–1 1.73 m2–1, a preoperative MAP less than 65 mm Hg, dialysis dependence, urologic surgery, age older than 60 years, and a surgical duration of less than 60 min. The primary exposure was IOH, and the primary outcome was AKI (50% or 0.3 mg dL–1 increase in creatinine) during the first 7 postoperative days. Multivariable logistic regression was used to model the exposure-outcome relationship. Results: AKI occurred in 186 (3.76%) noncardiac surgery patients. The adjusted odds ratio for surgery-related AKI for a MAP of less than 55 mm Hg was 14.11 (95% confidence interval: 5.02–39.69) for an exposure of more than 20 min. Age was not an interaction factor between AKI and IOH. Conclusion: There was a considerably increased risk of postoperative AKI when intraoperative MAP was less than 55 mm Hg for more than 10 min. Strict blood pressure management is recommended even for patients younger than 60 years old

Gains in QTL Detection Using an Ultra-High Density SNP Map Based on Population Sequencing Relative to Traditional RFLP/SSR Markers

Huge efforts have been invested in the last two decades to dissect the genetic bases of complex traits including yields of many crop plants, through quantitative trait locus (QTL) analyses. However, almost all the studies were based on linkage maps constructed using low-throughput molecular markers, e.g. restriction fragment length polymorphisms (RFLPs) and simple sequence repeats (SSRs), thus are mostly of low density and not able to provide precise and complete information about the numbers and locations of the genes or QTLs controlling the traits. In this study, we constructed an ultra-high density genetic map based on high quality single nucleotide polymorphisms (SNPs) from low-coverage sequences of a recombinant inbred line (RIL) population of rice, generated using new sequencing technology. The quality of the map was assessed by validating the positions of several cloned genes including GS3 and GW5/qSW5, two major QTLs for grain length and grain width respectively, and OsC1, a qualitative trait locus for pigmentation. In all the cases the loci could be precisely resolved to the bins where the genes are located, indicating high quality and accuracy of the map. The SNP map was used to perform QTL analysis for yield and three yield-component traits, number of tillers per plant, number of grains per panicle and grain weight, using data from field trials conducted over years, in comparison to QTL mapping based on RFLPs/SSRs. The SNP map detected more QTLs especially for grain weight, with precise map locations, demonstrating advantages in detecting power and resolution relative to the RFLP/SSR map. Thus this study provided an example for ultra-high density map construction using sequencing technology. Moreover, the results obtained are helpful for understanding the genetic bases of the yield traits and for fine mapping and cloning of QTLs

Status and Development Tendency for Seafloor Terrain Measurement Technology

This paper briefly reviewed the history of seafloor terrain measuring technology,and then detailed the introduced sonar bathymetry based on vessel,airborne laser bathymetry,integrated measurement for coastal topography and three inversion methods for seafloor terrain.That entirely presents the current situation of stereoscopic,efficient,high-accuracy and high-resolution of seafloor topography acquirement.Finally,combined with the future requirements,this paper summarized the core job and development trend in future seafloor terrain measuring field,which includes developing more portable multi-beam system with ultra-wide coverage,high accuracy and resolution,researching more efficient correction model of sound velocity effects,smoothing of bathymetry data and expression of submarine topography.Meanwhile,automatic ship measurement will be an important task mode.Also airborne laser survey,seafloor topography inversion from sonar image and deep-towing measurement has enormous potential in development

The effect of preoperative smoking cessation and smoking dose on postoperative complications following radical gastrectomy for gastric cancer: a retrospective study of 2469 patients

Abstract Background To investigate whether smoking adversely affects the short-term outcomes and the potential effects of cigarette dose and preoperative smoking cessation, in patients who underwent gastric cancer (GC) surgery. Methods Two thousand, four hundred sixty-nine consecutive patients who underwent radical gastrectomy from November 2010 to July 2018 were included in the present study. Smokers (current or former smokers) were divided into 3 groups in accordance with the duration of smoking cessation preoperatively (≤ 2, 2 to 4, or ≥ 4 weeks) and the cigarette dose (≤ 20, 20 to 40, and ≥ 40 pack-years). The primary endpoint was postoperative complications (surgical site infection, pulmonary problems, bleeding, and others). Results A total of 1056 patients (42.8%) were smokers. Compared with non-smokers, smokers had significantly higher overall postoperative complications (11.3% vs 7.5%, P = 0.001), and in particular pulmonary problems. Smokers also had more major complications, needing intensive care unit care, and longer postoperative hospital stays. Multivariate analysis confirmed that smoking (odds ratio = 1.506, 95% confidence interval 1.131–2.004, P = 0.005) was an independent risk factor for postoperative complications. Further subgroup analysis identified that there was a positive relationship between the incidence of complications and cigarette dose, and > 20 pack-years was demonstrated to have increased significantly the risk of complications. Smokers who stopped smoking ≥ 4 weeks before surgery had lower pulmonary problems than those with a shorter period of smoking cessation. Conclusions Preoperative smoking cessation should be encouraged to reduce postoperative complications in GC patients, especially for heavy smokers

Kalman filter applied in underwater integrated navigation system

For the underwater integrated navigation system, information fusion is an important technology. This paper introduces the Kalman filter as the most useful information fusion technology, and then gives a summary of the Kalman filter applied in underwater integrated navigation system at present, and points out the further research directions in this field

Application of precise point positioning technology in airborne gravity measurement

The precise point positioning (PPP) technology is applied to an airborne gravity survey. By analyzing the advantages and disadvantages of several velocity and acceleration measurement methods and in combination with an actual marine gravity survey, the position difference method is confirmed to be a useful survey method for velocity and acceleration. Finally, the practicability of using PPP in airborne marine gravity survey is verified by measured data