DMU-Net: A Dual-Stream Multi-Scale U-Net Network Using Multi-Dimensional Spatial Information for Urban Building Extraction

Automatically extracting urban buildings from remote sensing images has essential application value, such as urban planning and management. Gaofen-7 (GF-7) provides multi-perspective and multispectral satellite images, which can obtain three-dimensional spatial information. Previous studies on building extraction often ignored information outside the red–green–blue (RGB) bands. To utilize the multi-dimensional spatial information of GF-7, we propose a dual-stream multi-scale network (DMU-Net) for urban building extraction. DMU-Net is based on U-Net, and the encoder is designed as the dual-stream CNN structure, which inputs RGB images, near-infrared (NIR), and normalized digital surface model (nDSM) fusion images, respectively. In addition, the improved FPN (IFPN) structure is integrated into the decoder. It enables DMU-Net to fuse different band features and multi-scale features of images effectively. This new method is tested with the study area within the Fourth Ring Road in Beijing, and the conclusions are as follows: (1) Our network achieves an overall accuracy (OA) of 96.16% and an intersection-over-union (IoU) of 84.49% for the GF-7 self-annotated building dataset, outperforms other state-of-the-art (SOTA) models. (2) Three-dimensional information significantly improved the accuracy of building extraction. Compared with RGB and RGB + NIR, the IoU increased by 7.61% and 3.19% after using nDSM data, respectively. (3) DMU-Net is superior to SMU-Net, DU-Net, and IEU-Net. The IoU is improved by 0.74%, 0.55%, and 1.65%, respectively, indicating the superiority of the dual-stream CNN structure and the IFPN structure

Effects of different sex ratios on the growth and ovarian development of the ridgetail white shrimp, Exopalaemon carinicauda

To study the effects of sex ratio differences on the growth and ovarian development of Exopalaemon carinicauda, and their mechanism, we cultured female shrimps with different numbers of males for five weeks, and measured the growth and ovarian development index of relevant individuals. The results show that: 1) the existence of males reduced the growth rate of females, but significantly improved the ovarian development rate of female individuals. The growth rate of females living with the same sex was significantly accelerated, but their ovarian development rates were relatively slow. 2) Four kinds of communication modes between females and males were tested; i.e., free contact, chemical signals, visual signals, and coexisting chemical and visual signals. Of these four types, free contact improved the ovarian development of females. Under the condition of free contact, the period of the ovarian development cycle was shortened, more nutrients accumulated in the ovary, the amount of sex hormones and Vitellogenin (Vg) increased, and the expression of the gonad-inhibitory hormone (gih) gene tended to decrease. We speculated that testosterone released by males may play an important role in these phenomena. 3) Although the different sex ratios had no significant effect on the growth of females, the speed of ovarian development significantly increased when the female: male ratio was 1:2

Endovascular Therapy for Basilar Artery Occlusion in Sudden Onset to Maximal Deficit Ischemic Events

Background The presence of sudden onset to maximal deficit (SOTMD) in patients with acute basilar artery occlusion often results in more severe outcomes. However, the effect of endovascular therapy on SOTMD and whether the outcome is affected by onset‐to‐puncture time remain unclear. Methods and Results This retrospective analysis was conducted using data from the prospective BASILAR (Endovascular Treatment for Acute Basilar Artery Occlusion Study Registry). Consecutive patients with basilar artery occlusion receiving endovascular therapy were dichotomized into SOTMD and non‐SOTMD cohorts. The primary outcomes included a favorable outcome (modified Rankin scale 0–3), recanalization, and mortality at 90 days. The outcomes of patients with SOTMD were analyzed using multivariable logistic regression. In the multivariate analysis, a favorable outcome was similar between the two cohorts (odds ratio [OR], 0.88 [95% CI, 0.58–1.34]; P=0.5), although the mortality of patients with SOTMD was higher than that of patients with non‐SOTMD (OR, 1.67 [95% CI, 1.14–2.44]; P=0.008). The probability of mortality increased from 40.0% at 1 hour to 70.0% at 6 hours in the SOTMD cohort, and favorable outcomes of patients with non‐SOTMD declined from 38.0% at 1 hour to 18.0% at 8 hours. Conclusions No significant difference was observed in favorable outcomes between the SOTMD and non‐SOTMD groups, although mortality was higher in the SOTMD cohort. The patients with SOTMD had a stronger time dependence for endovascular therapy in terms of mortality, while the time dependency regarding favorable outcome in the NSOTMD group was even higher. Registration URL: https://www.chictr.org.cn; Unique identifier: ChiCTR1800014759