Bias Correction for Precipitation Simulated by RegCM4 over the Upper Reaches of the Yangtze River Based on the Mixed Distribution Quantile Mapping Method

Traditional multi-parameter single distribution quantile mapping (QM) methods excel in some respects in correcting climate model precipitation, but are limited in others. Multi-parameter mixed distribution quantile mapping can potentially exploit the strengths of single distribution methods and avoid their weaknesses. The correction performance of mixed distribution QM methods varies with the geographical location they are applied to and the combination of distributions that are included. This study compares multiple sets of single distribution and multi-parameter mixed distribution QM methods in order to correct the precipitation bias in the upper reaches of the Yangtze River basin (UYRB) in RegCM4 simulated precipitation. The results show that, among the selected distributions, the gamma distribution has the highest performance in the basin; explaining more than 50% of the precipitation events based on the weighting coefficients. The Gumbel distribution had the worst performance, only explaining about 10% of the precipitation events. The performance parameters, such as the root mean square error (RMSE) and the correlation coefficient (R) of the corrected precipitation, that were derived by using mixed distribution were better than those derived by using single distribution. The QM method that is based on the gamma-generalized extreme value distribution best corrected the precipitation, could reproduce the annual cycle and geographical pattern of observed precipitation, and could significantly reduce the wet bias from the RegCM4 model in the UYRB. In addition to enhancing precipitation climatology, the correction method also improved the simulation performance of the RegCM4 model for extreme precipitation events.

MACROPHYTIC DIVERSITY OF SOME WETLANDS OF JAMMU REGION, J&K, INDIA

The present ecological investigation communicates the macrophytic diversity of six wetlands of Jammu region comprising of three lacustrine wetlands viz. Surinsar, Mansar and Sanasar and three riverine wetlands i.e., Gharana, Kukarian and Pargwal. A total of 43 macrophytic species belonging to 34 genera and 24 families with 30 monocot species and 13 dicots were recorded, thereby showing the dominance of monocot flora. Among various ecological groups, emergent with 22 species showed qualitative dominance over submersed (13 species) and rooted floatingleaved types=free-floating types (4 species each). The present study revealed that there is no well-marked variation in the macrophytic groups among the studied wetlands and mostly mixed distribution was observed. Maximum macrophytic diversity was recorded in Mansar wetland (26) followed by Pargwal (22), Surinsar (16), Gharana (14), Kukarian (14) and Sanasar (11). The present study provides a baseline information on the macropytes of wetlands for subsequent research on the vital aspects of these aquatic ecosystems and would be helpful in planning management strategies.

EXPRESS: Cerebral microbleeds development after stroke thrombolysis: A secondary analysis of the THAWS randomized clinical trial

Background and aim: We determined to investigate the incidence and clinical impact of new cerebral microbleeds (CMBs) after intravenous thrombolysis (IVT) in patients with acute stroke. Methods: The THAWS was a multicenter, randomized trial to study the efficacy and safety of IVT with alteplase in patients with wake-up stroke or unknown onset stroke. Prescheduled T2*-weighted imaging assessed CMBs at 3-time points: baseline, 22–36 hours, and 7–14 days. Outcomes included new CMBs development, modified Rankin Scale [mRS] ≥3 at 90 days, and change in the National Institutes of Health Stroke Scale [NIHSS] score from 24 h to 7 days. Results: Of all 131 patients randomized in the THAWS trial, 113 patients (mean 74.3±12.6 years, 50 female, 62 allocated to IVT) were available for analysis. Overall, 46 (41%) had baseline CMBs (15 strictly lobar CMBs, 14 mixed CMBs, and 17 deep CMBs). New CMBs only emerged in the IVT group (7 patients, 11%) within a median of 28.3 h, and did not additionally increase within a median of 7.35 days. In adjusted models, number of CMBs (relative risk [RR]1.30, 95%confidence interval [CI]: 1.17–1.44), mixed distribution (RR 19.2, 95%CI: 3.94–93.7), and CMBs burden ≥5 (RR 44.9, 95%CI: 5.78–349.8) were associated with new CMBs. New CMBs was associated with an increase in NIHSS score (p=0.023). Treatment with alteplase in patients with baseline ≥5 CMBs resulted in a numerical shift toward worse outcomes on ordinal mRS (median [IQR]; 4 [3–4] vs. 0 [0–3]), compared with those with <5 CMBs (common odds ratio 17.1, 95% CI: 0.76 –382.8). The association of baseline ≥5 CMBs with ordinal mRS score differed according to the treatment group (P interaction=0.042). Conclusion: New CMBs developed within 36 h in 11% of the patients after IVT, and they were significantly associated with mixed-distribution and ≥5 CMBs. New CMBs development might impede neurological improvement. Furthermore, CMBs burden might affect the effect of alteplase.

Study of configuration problems of arc-suppression coils

The paper considers methods of configuration of arc-suppression coils in cable, air and mixed distribution networks of 6-35 kV. A special attention the authors have dedicated to influence of external factors (natural unbalance of network and interference) on configuration quality, as well as the maintenance of value of neutral point displacement voltage in acceptable limits. As a result, the authors have analysed the existing methods and suggested mew ones for elimination of influence of the specified factors.

The diagnostic value of Superb Microvascular Imaging in identifying benign tumors of parotid gland

Background We compared the ultrasound features, superb microvascular imaging (SMI) and micro vessel density (MVD) of pleomorphic adenoma (PA), Warthin’s tumor (WT) and basal cell adenoma (BCA) to explore the clinic value of SMI in differential diagnosis of benign tumors of parotid gland. Methods The vascular distributions and grade by color doppler flow imaging (CDFI) and SMI, as well as vascular index (VI) of 249 parotid gland masses from 217 patients were analyzed. Results The internal echogenicity of BCA are more homogeneous in comparing with WT and PA(P < 0.05). By SMI, the vascular distribution and vascular grade in PA were mainly peripheral (33.1%) and avascular (25.7%), Grade 1 (27.8%) and Grade 0 (25.7%). WT were mainly central (31.3%) and mixed distribution (34.9%), in Grade 3 (37.3%) and Grade 2 (36.2%). BCA was mainly peripheral (33.3%) and mixed distribution (33.3%), in Grade 2 (33.3%) and Grade 3 (33.3%). The overall detection rate of SMI for vascular Grade 2 and 3 was significantly higher than that of CDFI (P < 0.05). Both VI and MVD were lowest in PA, highest in WT (P < 0.001). The VI by SMI was correlated with MVD (P < 0.001). The correlation index between vascular distribution and grade by SMI and MVD were significantly higher than CDFI. Conclusion SMI can provide low-velocity blood flow information, which is helpful for the differential diagnosis of common benign tumors of parotid gland, and is expected to be more widely used.