Nearly Optimal Stochastic Approximation for Online Principal Subspace Estimation

Processing streaming data as they arrive is often necessary for high dimensional data analysis. In this paper, we analyse the convergence of a subspace online PCA iteration, as a followup of the recent work of Li, Wang, Liu, and Zhang [Math. Program., Ser. B, DOI 10.1007/s10107-017-1182-z] who considered the case for the most significant principal component only, i.e., a single vector. Under the sub-Gaussian assumption, we obtain a finite-sample error bound that closely matches the minimax information lower bound of Vu and Lei [Ann. Statist. 41:6 (2013), 2905-2947].Comment: 37 page

Prediction of the potential distribution area of Glycyrrhiza inflata in China using a MaxEnt model

Glycyrrhiza inflata Batalin is an important medical plant of the genus Glycyrrhiza. It is one of the key protected plants in China, distributed in the desert areas of southern Xinjiang and Dunhuang of Gansu Province. It has a strong resistance to drought, heat, and salt stresses, and plays a pivotal role in sand fixtion in desert areas. In this study, based on 157 valid distribution records and eight environmental factors including climate factors and altitude, the potential distribution area of G. inflata in the last glacial maximum, middle Holocen, modern, and future (2050) times in China were predicted, using the optimized MaxEnt model and ArcGis 10.2 software. The results showed that the predicted distribution area was highly consistent with the current distribution range, and the area under the receiver operating characteristic (AUC) curve was 0.986, indicating that the prediction performance was excellent. The key climatic factors affecting the distribution were precipitation in December and the average annual precipitation. Meanwhile, the suitable area of G. inflata in modern times was 1,831,026 km2, mainly distributed in Turpan-Hami Basin, Tarim Basin, and Dunhuang of Gansu Province, with Lop Nur Town of Xinjiang as the distribution center. In 2050, the potential suitable area forG. inflata in China will be 1,808,090 km2, 250,970 km2 of which will be highly suitable, which is 150,600 km2 smaller than that in modern times, with a reduction rate of 60.0%. Therefore, there is a trend of great reduction in the suitable area of G. inflata. From the last glaciation maximum to the middle Holocene, the geographical distribution center shifted to the southwest margin of the Kumtag Desert, Xinjiang, then later continued to shift to the southwest. This study will provide a basis for understanding the origin and evolution of G. inflata, developing conservation strategies to minimize the impacts of environment change, and utilizing plant resource

Climate services for addressing climate change: Iindication of a climate livable city in China

China, like many countries, is under great pressure to reduce climate change and adapt to current situations while simultaneously undertaking economic development and transformation. This study takes advantage of climate opportunities and provides a new concept and mode of urban climate services in order to address climate change. Eighteen indicators based on climate and climate-related variables were used to provide an assessment, in the form of an index, of how livable a city is depending on prevailing climatic conditions. The resulting index can also be used to investigate how recent and future changes in the climatic conditions could affect livability. All Chinese cities and regions share the common goals of promoting low-carbon development, improving resilience against climate change, and integrating economic growth with climate actions. Climate services have been developed in China to provide decision-makers this measure of livability. Such a move facilitates sustainable development alongside economic growth by aiding government efforts in climate adaptation and low-carbon development. Our approach represents multidisciplinary and demand-driven research on adaptation to and the impacts of regional climate change, thereby transforming climate science into a climate service and ensuring that climate information can be provided in a scientific, practical, and customized way for policy-makers. The outputs can be used locally to take concrete climate actions and integrate climate services into decision-making processes

Global patient outcomes after elective surgery: prospective cohort study in 27 low-, middle- and high-income countries.

BACKGROUND: As global initiatives increase patient access to surgical treatments, there remains a need to understand the adverse effects of surgery and define appropriate levels of perioperative care. METHODS: We designed a prospective international 7-day cohort study of outcomes following elective adult inpatient surgery in 27 countries. The primary outcome was in-hospital complications. Secondary outcomes were death following a complication (failure to rescue) and death in hospital. Process measures were admission to critical care immediately after surgery or to treat a complication and duration of hospital stay. A single definition of critical care was used for all countries. RESULTS: A total of 474 hospitals in 19 high-, 7 middle- and 1 low-income country were included in the primary analysis. Data included 44 814 patients with a median hospital stay of 4 (range 2-7) days. A total of 7508 patients (16.8%) developed one or more postoperative complication and 207 died (0.5%). The overall mortality among patients who developed complications was 2.8%. Mortality following complications ranged from 2.4% for pulmonary embolism to 43.9% for cardiac arrest. A total of 4360 (9.7%) patients were admitted to a critical care unit as routine immediately after surgery, of whom 2198 (50.4%) developed a complication, with 105 (2.4%) deaths. A total of 1233 patients (16.4%) were admitted to a critical care unit to treat complications, with 119 (9.7%) deaths. Despite lower baseline risk, outcomes were similar in low- and middle-income compared with high-income countries. CONCLUSIONS: Poor patient outcomes are common after inpatient surgery. Global initiatives to increase access to surgical treatments should also address the need for safe perioperative care. STUDY REGISTRATION: ISRCTN5181700

Target Association of Heterogeneous Sensors Based on Nearest-neighbor and Topology

A new data association algorithm is proposed in this paper for heterogeneous sensors information fusion system, which consists of Radar and high-dynamic-range IR, based on joint usage of the nearest-neighbor (NN) and the topology similarity. The proposed algorithm can avoid the complicated system biases compensation based on topology information. Because the NN method is sensitive to the system bias while the existing topology-based algorithms need a large amount of computation, the proposed algorithm shows a lot of advantages, like high estimation accuracy and robustness as well as the improvement of success association rate. Finally, some numerical experiments are provided to demonstrate the effectiveness of the proposed method. And the estimation accuracy can be as high as 90%

Mathematical model of humoral immune response to hepatitis B vaccines [Chinese language]

The hepatitis B vaccination is an effective measure to prevent and control the infection of hepatitis B virus(HBV)．The persistence of anti-HBs after anti-HBV vaccination and the maintenance of long-term immune memory has been the focus of attention．0n the basis of the hypothesis that long-lived plasma cells maintain the long-term immune response， a mathematical model of humoral immune response i8 formulated to describe the long-term variation of vaccine recipients’anti-HBs．After parameter values ale selected the model simulation is done to show the immune response of the recombinant and plasma-derived vaccines．The long-term immune response is also investigated based on the interaction of the persistence of antigen and long-lived plasma cells．The simulation results show that the model fits the post-vaccination antibody response data well．Finally，the impact of several parameters on the immune effect is discussed. The model and its simulation results may help people to understand the immune response

Concept of “seeking for oil and gas deep down depressions” in Liaohe peripheral Mesozoic basin

Small-scale strip Mesozoic sags in the Liaohe Oilfield peripheral basin are strongly divided and close to massifs, so they are mainly proximal and multisource deposits. Reservoirs in the sags have poor properties and are multidirectional, intersected sources which form sand-shale alternating deposits. Low permeability in the reservoirs causes oil and gas to migrate in short distances horizontally and vertically, and is distributed close to or in hydrocarbon kitchens horizontally and close to oil source vertically. The principle of “seeking for oil and gas deep down depressions” was proposed. Since its practice in 2004, good exploration results have been achieved. The next exploration targets in this area are Wushijiazimiao, Jiaolige and Sanshifangdi subsags in Lujiabu sag, Hulihai subsag in Qianjiandian sag, Eertu subsag in Longwantong sag, Zhanggutai and Qijiazi subsags in Zhangqiang sag, central subsag in Yuanbaoshan sag, and central subsag in Naiman sag. Key words: Liaohe periphery, Mesozoic basin, deep down depressions, exploration significangc

MICROWAVE-ASSISTED SYNTHESIS OF 2-AMINOPYRIMIDINES FROM SILICA GEL-ADSORBED PROPARGYL ALCOHOLS AND GUANIDINE

A novel methodology toward the synthesis of 2-aminopyrimidines has been developed. The silica gel adsorbed propargyl alcohols and guanidine easily give the corresponding 2-aminopyrimidines under microwave irradiation.NSFC [21072159]; 973 Projects [2011CB935901]; NFFTBS [J1030415]; Science & Technology Bureau of Xiamen [3502Z20103006