The effectiveness of the restricted policy on specific venues in Hong Kong: A spatial point pattern view.

After the fifth wave of the COVID-19 outbreak in May 2022, the Hong Kong government decided to ease the restrictions policy step by step. The main change was to re-open some venues that people like to visit and extend the hours of operation. With the implementation of the relaxed policy, however, the number of confirmed cases rose again. As a result, further relaxation was delayed. As an evaluation of the effectiveness of the restrictions policy could be a reference for future policies balancing viral spread and functionality of society, this paper aimed to respond to this question from the spatial point distribution view. The time, from late March 2020 to February 2021, during which the related policies took place was divided into six periods based on the policy trend (tightening or relaxing). The two-variable Ripley's Kfunction was applied for each period to explore the spatial dependence between confirmed cases and venues as changes in the spatial pattern can reveal the effect of the policy. The results show that, as time passed, the clustering degree decreased and reached its lowest level from August to mid-November 2020, then significantly increased, with the extent of clustering becoming more remarkable and the significant cluster size widening. Our results indicate that the policy had a positive effect on suppressing the spread of the virus in mid-July 2020. Then, with the virus infiltrating the community, the policy had little impact on containing the virus but likely contributed to avoid further infection.

Mycn regulates intestinal development through ribosomal biogenesis in a zebrafish model of Feingold syndrome 1.

Feingold syndrome type 1, caused by loss-of-function of MYCN, is characterized by varied phenotypes including esophageal and duodenal atresia. However, no adequate model exists for studying the syndrome's pathological or molecular mechanisms, nor is there a treatment strategy. Here, we developed a zebrafish Feingold syndrome type 1 model with nonfunctional mycn, which had severe intestinal atresia. Single-cell RNA-seq identified a subcluster of intestinal cells that were highly sensitive to Mycn, and impaired cell proliferation decreased the overall number of intestinal cells in the mycn mutant fish. Bulk RNA-seq and metabolomic analysis showed that expression of ribosomal genes was down-regulated and that amino acid metabolism was abnormal. Northern blot and ribosomal profiling analysis showed abnormal rRNA processing and decreases in free 40S, 60S, and 80S ribosome particles, which led to impaired translation in the mutant. Besides, both Ribo-seq and western blot analysis showed that mTOR pathway was impaired in mycn mutant, and blocking mTOR pathway by rapamycin treatment can mimic the intestinal defect, and both L-leucine and Rheb, which can elevate translation via activating TOR pathway, could rescue the intestinal phenotype of mycn mutant. In summary, by this zebrafish Feingold syndrome type 1 model, we found that disturbance of ribosomal biogenesis and blockage of protein synthesis during development are primary causes of the intestinal defect in Feingold syndrome type 1. Importantly, our work suggests that leucine supplementation may be a feasible and easy treatment option for this disease.

The fine-scale associations between socioeconomic status, density, functionality, and spread of COVID-19 within a high-density city.

BACKGROUND: Motivated by the need for precise epidemic control and epidemic-resilient urban design, this study aims to reveal the joint and interactive associations between urban socioeconomic, density, connectivity, and functionality characteristics and the COVID-19 spread within a high-density city. Many studies have been made on the associations between urban characteristics and the COVID-19 spread, but there is a scarcity of such studies in the intra-city scale and as regards complex joint and interactive associations by using advanced machine learning approaches. METHODS: Differential-evolution-based association rule mining was used to investigate the joint and interactive associations between the urban characteristics and the spatiotemporal distribution of COVID-19 confirmed cases, at the neighborhood scale in Hong Kong. The associations were comparatively studied for the distribution of the cases in four waves of COVID-19 transmission: before Jun 2020 (wave 1 and 2), Jul-Oct 2020 (wave 3), and Nov 2020-Feb 2021 (wave 4), and for local and imported confirmed cases. RESULTS: The first two waves of COVID-19 were found mainly characterized by higher-socioeconomic-status (SES) imported cases. The third-wave outbreak concentrated in densely populated and usually lower-SES neighborhoods, showing a high risk of within-neighborhood virus transmissions jointly contributed by high density and unfavorable SES. Starting with a super-spread which considerably involved high-SES population, the fourth-wave outbreak showed a stronger link to cross-neighborhood transmissions driven by urban functionality. Then the outbreak diffused to lower-SES neighborhoods and interactively aggravated the within-neighborhood pandemic transmissions. Association was also found between a higher SES and a slightly longer waiting period (i.e., the period from symptom onset to diagnosis of symptomatic cases), which further indicated the potential contribution of higher-SES population to the pandemic transmission. CONCLUSIONS: The results of this study may provide references to developing precise anti-pandemic measures for specific neighborhoods and virus transmission routes. The study also highlights the essentiality of reliving co-locating overcrowdedness and unfavorable SES for developing epidemic-resilient compact cities, and the higher obligation of higher-SES population to conform anti-pandemic policies.

Multiscale and local engineering of speckle morphology through disordered media.

In this Letter, we prompt a novel, to the best of our knowledge, method based on transmission matrix decomposition with wavelets to engineer the speckle morphology behind disordered media. By analyzing the speckles in multiscale spaces, we experimentally realized multiscale and localized control on the speckle size, position-dependent spatial frequency, and global morphology by operating on the decomposition coefficients using different masks. Speckles with contrasting features in different parts of the fields can be generated in one step. Our experimental results demonstrate a high degree of flexibility in manipulating light in a customizable manner. This technique has stimulating prospects in correlation control and imaging under scattering conditions.

[Effects of Different Water Stratification on the Vertical Distribution of Nitrogen in Sediment Interstitial Waters: A Case Study of the Three Gorges Reservoir and Xiaowan Reservoir].

To determine the reasons for the variation in the vertical distribution of nitrogen in sediment interstitial waters between different stratified reservoirs, the characteristics of overlying water-interstitial water in Xiangxi Bay, Yangtze River mainstream, and Xiaowan Reservoir were monitored. The vertical distribution of nitrogen in sediment interstitial waters in these different stratified waters were then analyzed, and the reasons for the variation in this distribution were assessed. The results showed:① the ρ(TN) in the sediment interstitial waters of the Yangtze River mainstream and Xiangxi Bay gradually increased with depth, while that of Xiaowan Reservoir reached its maximum at 12 cm and the bottom layer presented a "C" distribution. The ρ(NH4+) in the sediment interstitial waters of the Yangtze River mainstream and Xiangxi Bay exhibited an increasing trend with depth, while that of Xiaowan Reservoir was slightly higher in the bottom layer than in the surface layer, although the change with depth was not significant. Overall, the ρ(NH4+) in the sediment interstitial waters of the Yangtze River mainstream and Xiangxi Bay was higher than that of Xiaowan Reservoir, and the concentration ranges were as follows:0.512-8.289 mg·L-1, 0.968-9.307 mg·L-1, and 0.950-1.450 mg·L-1. The vertical distribution of the ρ(NO3-) in the sediment interstitial waters of all three waterbodies were opposite to that of ρ(NH4+). Moreover, the ρ(NO3-) in the sediment interstitial waters of Xiangxi Bay and the Yangtze River mainstream was higher than that of Xiaowan Reservoir. The concentration ranges were as follows:0.143-0.674 mg·L-1, 0.107-0.647 mg·L-1, and 0.050-0.051 mg·L-1. ② There were also significant differences in the vertical distribution of physical and chemical indices in the three water bodies. There was no significant change in the vertical distribution of the water temperature in the Yangtze River mainstream and the N2 value was <5×10-5 s-2; hence, the water was well mixed, and the vertical range of the dissolved oxygen content was 6.180-6.318 mg·L-1. The water temperature in the upper and middle reaches of Xiangxi Bay decreased vertically, while the water temperature in the lower reach presented a ladder-like distribution and the N2 values were all>5×10-5 s-2; thus, the water was in a stable stratified state and the dissolved oxygen content presented a "C" distribution. There was obvious stratification at the depths of 5-15 m and 54-70 m in Xiaowan Reservoir. The dissolved oxygen content decreased significantly at higher water temperature gradients, and there was no significant change along the water depth below 80 m. ③ The main reasons for the variation in the vertical distribution of nitrogen in the sediment interstitial waters of the three waterbodies were the differences in the overlying water hydrodynamics, dissolved oxygen distribution, and sediment environment. The ρ(NH4+) and ρ(NO3-) were higher in Xiangxi Bay, which may have increased the denitrification rate and subsequently have helped to remove nitrogen and reduce the nitrogen load in these waters.

The Establishment and Application Studies on Precise Lysosome pH Indicator Based on Self-Decomposable Nanoparticles.

Acidic pH of lysosomes is closely related to autophagy; thus, well known of the precise lysosomes, pH changes will give more information on the autophagy process and status. So far, however, only pH changes in a relatively broad range could be indicated, the exact lysosomes pH detection has never arrived. In our study, we established an endo/lysosome pH indicator based on the self-decomposable SiO2 nanoparticle system with specific synthesis parameters. The central concentrated methylene blue (MB) in the central-hollow structural nanoparticles presented sensitive release as a function of pH values from pH 4.0-4.8, which is exactly the pH range of lysosomes. The linear correlation of the optical density (OD) values and the pH values has been built up, which has been used for the detection of lysosomes pH in 6 different cell lines. Moreover, by this system, we succeeded in precisely detecting the pH average changes of lysosomes before and after black mesoporous silicon (BPSi) NP endocytosis, clarifying the mechanism of the autophagy termination after BPSi endocytosis. So, the self-decomposable nanoparticle-based luminal pH indicator may provide a new methodology and strategy to know better of the lysosome pH, then indicate more details on the autophagy process or other important signaling about metabolisms.

[Spatial and Temporal Distribution Characteristics and the Retention Effects of Nutrients in Xiangjiaba Reservoir].

After the construction of the Xiangjiaba Dam, the hydrodynamic conditions, nutrient distributions, and transport conditions of the Jinsha River were changed. Here, the nutrient distribution characteristics and retention effects of Xiangjiaba Reservoir were investigated according to the results of water quality monitoring from 2015 to 2016. Spatial and temporal variations in TN, TP, SiO32-Si, and other nutrients, and retention flux and retention rate were analyzed. The results showed that the nutrient mass concentration of TN, TP, and SiO32--Si was 0.905 mg·L-1, 0.034 mg·L-1, and 7.98 mg·L-1, respectively. The distribution of TN was affected by point sources and the concentration of TN was large in urban areas. This distribution of TP was mainly granular and the mass concentrations decreased along the river path. The mass concentration of SiO32--Si did not significantly vary over time and space. Furthermore, Xiangjiaba Reservoir had a persistent effect on nutrient salts; the average annual retention of TN, TP, and SiO32--Si was 2.30×104 t·a-1, 0.146×104 t·a-1, and -2.4×104 t·a-1, respectively. During different seasons, the retention of TN and SiO32--Si varied between positive or negative; however, TP appeared to be consistent. The average monthly retention efficiency of TN, TP, and SiO32--Si was 17.5%, 32.8%, and -2.14%, respectively. Overall, retention efficiencies were higher during the dry season than that wet season, and phosphorus retention was most pronounced. The retention of TN in the reservoir may be related to denitrification and the input of external load; the flux of SiO32--Si was mainly affected by runoff; and the particle morphology of phosphorus, as well as reservoir period, were the main factors affecting TP retention. There were no clear correlations between nutrient retention and the mass concentrations of TN and SiO32--Si, but the nutrient retention effect of Xiangjiaba Reservoir reduced TP concentrations along the river path and increased TP concentration with vertical depth.