Air pollutant prediction model based on transfer learning two-stage attention mechanism.

Atmospheric pollution significantly impacts the regional economy and human health, and its prediction has been increasingly emphasized. The performance of traditional prediction methods is limited due to the lack of historical data support in new atmospheric monitoring sites. Therefore, this paper proposes a two-stage attention mechanism model based on transfer learning (TL-AdaBiGRU). First, the first stage of the model utilizes a temporal distribution characterization algorithm to segment the air pollutant sequences into periods. It introduces a temporal attention mechanism to assign self-learning weights to the period segments in order to filter out essential period features. Then, in the second stage of the model, a multi-head external attention mechanism is introduced to mine the network's hidden layer key features. Finally, the adequate knowledge learned by the model at the source domain site is migrated to the new site to improve the prediction capability of the new site. The results show that (1) the model is modeled from the data distribution perspective, and the critical information within the sequence of periodic segments is mined in depth. (2) The model employs a unique two-stage attention mechanism to capture complex nonlinear relationships in air pollutant data. (3) Compared with the existing models, the mean absolute error (MAE), root mean square error (RMSE), and mean absolute percentage error (MAPE) of the model decreased by 14%, 13%, and 4%, respectively, and the prediction accuracy was greatly improved.

Spatial and temporal characteristics analysis and prediction model of PM2.5 concentration based on SpatioTemporal-Informer model.

The primary cause of hazy weather is PM2.5, and forecasting PM2.5 concentrations can aid in managing and preventing hazy weather. This paper proposes a novel spatiotemporal prediction model called SpatioTemporal-Informer (ST-Informer) in response to the shortcomings of spatiotemporal prediction models commonly used in studies for long-input series prediction. The ST-Informer model implements parallel computation of long correlations and adds an independent spatiotemporal embedding layer to the original Informer model. The spatiotemporal embedding layer captures the complex dynamic spatiotemporal correlations among the input information. In addition, the ProbSpare Self-Attention mechanism in this model can focus on extracting important contextual information of spatiotemporal data. The ST-Informer model uses weather and air pollutant concentration data from numerous stations as its input data. The outcomes of the trials indicate that (1) The ST-Informer model can sharply capture the peaks and sudden changes in PM2.5 concentrations. (2) Compared to the current models, the ST-Informer model shows better prediction performance while maintaining high-efficiency prediction [Formula: see text]. (3) The ST-Informer model has universal applicability, and the model was applied to the concentration of other pollutants prediction with good results.

Surgical results and prognostic factors following percutaneous full endoscopic posterior decompression for thoracic myelopathy caused by ossification of the ligamentum flavum.

Minimally invasive surgery (MIS) has shown satisfactory surgical results for the treatment of thoracic myelopathy (TM) caused by ossification of the ligamentum flavum (OLF). This study investigated the prognostic factors following MIS and was based on the retrospective analysis of OLF patients who underwent percutaneous full endoscopic posterior decompression (PEPD). Thirty single-segment OLF patients with an average age of 60.4 years were treated with PEPD under local anaesthesia. Clinical data were collected from the medical and operative records. The surgical results were assessed by the recovery rate (RR) calculated from the modified Japanese Orthopaedic Association (mJOA) score. Correlations between the RR and various factors were analysed. Patients' neurological status improved from a preoperative mJOA score of 6.0 ± 1.3 to a postoperative mJOA score of 8.5 ± 2.0 (P < 0.001) at an average follow-up of 21.3 months. The average RR was 53.8%. Dural tears in two patients (6.7%, 2/30) were the only observed complications. Multiple linear regression analysis showed that a longer duration of preoperative symptoms and the presence of a high intramedullary signal on T2-weighted MRI (T2HIS) were significantly associated with poor surgical results. PEPD is feasible for the treatment of TM patients with a particular type of OLF. Patients without T2HIS could achieve a good recovery if they received PEPD early.

Percutaneous full endoscopic posterior decompression of thoracic myelopathy caused by ossification of the ligamentum flavum.

PURPOSE: Ossification of ligamentum flavum (OLF) is the leading cause of progressive thoracic myelopathy (TM) in East Asian countries. Surgical decompression is the general treatment for TM. This study investigated the application of percutaneous full endoscopic posterior decompression (PEPD) for the treatment of thoracic OLF. METHODS: Eighteen patients with TM were treated by PEPD under local anaesthesia. Patients had an average age of 59.1 years and single-level lesions mostly at the lower thoracic vertebrae. Computed tomography and magnetic resonance imaging were used to classify the OLF. The pre- and postoperative neurological statuses were evaluated using the American Spinal Injury Association (ASIA) sensory and motor score, modified Japanese Orthopaedic Association (mJOA) score and Frankel grade. RESULTS: OLF for all patients was classed as lateral, extended, and enlarged types without comma and tram track signs. Decompression was completed, and a dome-shaped laminotomy was performed through limited laminectomy and flavectomy. Dural tears in 2 patients were the only observed complication. The average score of ASIA sensory and motor, mJOA, as well as the Frankel grade improved significantly after surgery at an average follow-up time of 17.4 months. The average recovery rate (RR) was 47.5% as calculated from the mJOA scores. According to RR, 10 cases were classified as good, 4 cases fair, and 4 cases unchanged. CONCLUSIONS: For patients with thoracic OLF at a single level and lateral, extended, and enlarged types without comma and tram track signs, it is safe and reliable to perform PEPD, which has satisfactory clinical results. These slides can be retrieved under Electronic Supplementary Material.

Response of soil organic carbon fractions, microbial community composition and carbon mineralization to high-input fertilizer practices under an intensive agricultural system.

Microbial mechanisms associated with soil organic carbon (SOC) decomposition are poorly understood. We aim to determine the effects of inorganic and organic fertilizers on soil labile carbon (C) pools, microbial community structure and C mineralization rate under an intensive wheat-maize double cropping system in Northern China. Soil samples in 0-10 cm layer were collected from a nine-year field trial involved four treatments: no fertilizer, CK; nitrogen (N) and phosphorus (P) fertilizers, NP; maize straw combined with NP fertilizers, NPS; and manure plus straw and NP fertilizers, NPSM. Soil samples were analyzed to determine labile C pools (including dissolved organic C, DOC; light free organic C, LFOC; and microbial biomass C, MBC), microbial community composition (using phospholipid fatty acid (PLFA) profiles) and SOC mineralization rate (from a 124-day incubation experiment). This study demonstrated that the application of chemical fertilizers (NP) alone did not alter labile C fractions, soil microbial communities and SOC mineralization rate from those observed in the CK treatment. Whereas the use of straw in conjunction with chemical fertilizers (NPS) became an additional labile substrate supply that decreased C limitation, stimulated growth of all PLFA-related microbial communities, and resulted in 53% higher cumulative mineralization of C compared to that of CK. The SOC and its labile fractions explained 78.7% of the variance of microbial community structure. Further addition of manure on the top of straw in the NPSM treatment did not significantly increase microbial community abundances, but it did alter microbial community structure by increasing G+/G- ratio compared to that of NPS. The cumulative mineralization of C was 85% higher under NPSM fertilization compared to that of CK. Particularly, the NPSM treatment increased the mineralization rate of the resistant pool. This has to be carefully taken into account when setting realistic and effective goals for long-term soil C stabilization.

Seasonal Patterns of Soil Respiration and Related Soil Biochemical Properties under Nitrogen Addition in Winter Wheat Field.

Understanding the changes of soil respiration under increasing N fertilizer in cropland ecosystems is crucial to accurately predicting global warming. This study explored seasonal variations of soil respiration and its controlling biochemical properties under a gradient of Nitrogen addition during two consecutive winter wheat growing seasons (2013-2015). N was applied at four different levels: 0, 120, 180 and 240 kg N ha(-1) year(-1) (denoted as N0, N12, N18 and N24, respectively). Soil respiration exhibited significant seasonal variation and was significantly affected by soil temperature with Q10 ranging from 2.04 to 2.46 and from 1.49 to 1.53 during 2013-2014 and 2014-2015 winter wheat growing season, respectively. Soil moisture had no significant effect on soil respiration during 2013-2014 winter wheat growing season but showed a significant and negative correlation with soil respiration during 2014-2015 winter wheat growing season. Soil respiration under N24 treatment was significantly higher than N0 treatment. Averaged over the two growing seasons, N12, N18 and N24 significantly increased soil respiration by 13.4, 16.4 and 25.4% compared with N0, respectively. N addition also significantly increased easily extractable glomalin-related soil protein (EEG), soil organic carbon (SOC), total N, ammonium N and nitrate N contents. In addition, soil respiration was significantly and positively correlated with ß-glucosidase activity, EEG, SOC, total N, ammonium N and nitrate N contents. The results indicated that high N fertilization improved soil chemical properties, but significantly increased soil respiration.

[Mini-incision posterior laminectomy by fenestration in the treatment of huge lumbar disc herniation].

OBJECTIVE: To discuss clinical effects and methods of mini-incision posterior laminectomy by fenestration in the treatment of huge lumbar disc herniation. METHODS: From 1999 to 2008,107 patients with huge protruded lumbar intervertebral disc were retrospectively analyzed including 78 males and 29 females with an average age of 38.5 years ranging from 26 to 59 years. The patients were operated with mini-incision posterior laminectomy by fenestration. The affected region of patients were L4.5 (36 cases), L5S1 (71 cases). The herniation rate of nucleus was more than 40%. The patient's scores based on low back pain improved JOA standard were retrospectively analyzed. RESULTS: The 107 patients were followed-up for from 0.5 to 4 years with an average of 1.75 years. The scores by low back pain improved JOA standard were improved from (1.500 +/- 1.200) before operation to (12.700 +/- 0.950) after operation. The average improvement rate was (82.96 +/- 6.85)%. CONCLUSION: It is a reliable method in the treatment of huge lumbar disc herniation with mini-incision posterior laminectomy by fenestration. The treatment method have advantage with less trauma, good spinal stability, conducive to patient recovery and maintain clinical efficacy.