On Optimal Finite-length Binary Codes of Four Codewords for Binary Symmetric Channels

Finite-length binary codes of four codewords are studied for memoryless binary symmetric channels (BSCs) with the maximum likelihood decoding. For any block-length, best linear codes of four codewords have been explicitly characterized, but whether linear codes are better than nonlinear codes or not is unknown in general. In this paper, we show that for any block-length, there exists an optimal code of four codewords that is either linear or in a subset of nonlinear codes, called Class-I codes. Based on the analysis of Class-I codes, we derive sufficient conditions such that linear codes are optimal. For block-length less than or equal to 8, our analytical results show that linear codes are optimal. For block-length up to 300, numerical evaluations show that linear codes are optimal.Comment: accepted by ISITA 202

Contingent valuation of Yangtze finless porpoises in Poyang Lake, China

Yangtze finless porpoises (YFPs) are the only fresh-water adapted porpoises in the world and they are endemic to Yangtze River system, including Poyang Lake. They are threatened by many factors, such as illegal fishing and overfishing, sand dredging, intensive shipping traffic, and pollution from agriculture and industry. Consequently, their population is decreasing at a great rate and they are listed as an endangered rare species on the red list of the International Union for Conservation of Nature (IUCN) since 1996. Moreover, a hydroelectricity project in Poyang Lake is in planning by the state of Jiangxi province, which will generate further serious threats to YFPs by cutting off their migration route and fragmenting their habitat. Therefore, it is very urgent to take some protection measures for YFPs. A special nature reserve is one possibility to protect YFPs, such as a nature reserve area, which is located in Poyang Lake. In order to find out whether a nature reserve is worthwhile, an economic analysis valuing the benefit of YFPs has been conducted. An appropriate method, the contingent valuation approach, has been chosen. The overall aim of such a contingent valuation study is to estimate the total benefits of YFPs by asking individuals’ willingness to pay for the porpoise conservation project. Because many people are unfamiliar with YFPs and the species’ total values consist of mainly non-use values, preference construction and estimating a demand function is a complex task. Therefore, the valuation workshop method, a group-based approach, which can make respondents motivated and well-informed so that they thoroughly consider the questions, provides a realistic decision-making environment. This method was selected to help respondents construct their preference. Within this study, a series of such valuation workshops were successfully organized and data and information were collected. The findings of the study have both methodological and policy-related implications. From the perspective of methodology, the important findings include: 1) Valid response rates are high enough to support further analysis and large mean WTP for porpoise conservation are obtained. Therefore, it can be concluded that the valuation workshop method as has been chosen in this study, is suitable for valuing porpoise conservation. The valuation workshop method can make people well informed about environmental goods and services, such as rare species, so that they can build their preference about them, which is quite a complex task for many individuals. IV 2) Distance effects are verified to fail to work on willingness to pay (WTP) for porpoise conservation, which is mostly driven by non-use values. Therefore, distance need not be included in the aggregation analysis of total benefits of YFPs. Similarly, the market for conservation of YFPs can be defined as the nation of China. And the sampling frame of such an evaluation of a rare species can be all the Chinese population. 3) Income effects are confirmed to be significantly influential for both Chinese respondents and German respondents. Hence, the aggregation of total values of YFPs should consider about individuals’ income levels and their ability to pay (ATP). It is inferred from the fact of smaller mean WTP in China as compared with Germany that some low-income respondents’ WTP bids are possibly distorted by their ATP, which needs further confirmation in follow-up research. In addition, there are also some policy-related implications, which are closely related with the mentioned methodological aspect: The total economic values of porpoise conservation are predicted to be appreciably huge. Definitely, their total benefits should be taken into account by politicians and decision-makers. This study makes explicit people’s attitudes and preference on the trade-off between economic growth and ecological use. The establishment of a special nature reserve for YFPs is still an open question

Mediator complex subunit 19 regulates the proliferation, migration and invasion of human breast cancer cells

Purpose: To investigate the therapeutic implication of mediator complex subunit 19 (Med19) in breast cancer cells. Methods: The mRNA expression of Med19 was assayed using qRT-PCR. Cell viability was determined with 3-(4,5-dimethylthiazol-2-yl)2,5-diphenyl tetrazolium bromide (MTT) assay, while 4′,6-diamidino-2- phenylindole (DAPI) and annexin V/propidium iodide (PI) assays were used for determination of apoptosis. Wound healing and Transwell assays were used for the determination of cell migration and invasion. Western blotting analysis was used for assay of protein expression levels. Results: The results showed that Med19 was significantly (p < 0.05) upregulated in human breast cancer cell lines, relative to normal cells. The up-regulations ranged from 3.7-fold in UACC-2087 cells to 6.4-fold in BT-20 cells. Moreover, Med19 silencing caused significant decrease in the proliferation of BT-20 breast cancer cells (p < 0.05). The inhibition of cell proliferation was due to the induction of apoptosis, as was evident in increased Bax/Bcl-2 ratio. Annexin V/PI staining revealed 6 % apoptosis in si-NC-transfected, and about 13.30 % in si-Med19-transfected BT-20 cells. Wound healing and Transwell assays revealed that the invasion of BT-20 breast cancer cells significantly decreased upon Med19 silencing. Conclusion: Med19 regulates the proliferation, migration and invasion of human breast cancer cells. Thus, Med19 may be beneficial in the treatment of breast cancer

On Achievable Rates of Line Networks with Generalized Batched Network Coding

To better understand the wireless network design with a large number of hops, we investigate a line network formed by general discrete memoryless channels (DMCs), which may not be identical. Our focus lies on Generalized Batched Network Coding (GBNC) that encompasses most existing schemes as special cases and achieves the min-cut upper bounds as the parameters batch size and inner block length tend to infinity. The inner blocklength of GBNC provides upper bounds on the required latency and buffer size at intermediate network nodes. By employing a bottleneck status technique, we derive new upper bounds on the achievable rates of GBNCs These bounds surpass the min-cut bound for large network lengths when the inner blocklength and batch size are small. For line networks of canonical channels, certain upper bounds hold even with relaxed inner blocklength constraints. Additionally, we employ a channel reduction technique to generalize the existing achievability results for line networks with identical DMCs to networks with non-identical DMCs. For line networks with packet erasure channels, we make refinement in both the upper bound and the coding scheme, and showcase their proximity through numerical evaluations.Comment: This paper was presented in part at ISIT 2019 and 2020, and is accepted by a JSAC special issu

Suppression of hepatitis B virus replication by SRPK1 and SRPK2 via a pathway independent of the phosphorylation of the viral core protein

AbstractThe SR-domain protein kinase (SRPK) 1 and 2 are two important kinases involved in cellular RNA splicing. Recently, it was suggested that these two kinases, which could bind to the hepatitis B virus (HBV) core protein, might be the major cellular kinases that phosphorylate the core protein to regulate HBV replication. In this report, we tested the role of SRPK1 and SRPK2 in HBV replication and found that both of them could suppress HBV replication by reducing the packaging efficiency of the pgRNA without affecting the formation of the viral core particles. This suppressive effect of SRPK1 and SRPK2 on HBV replication cannot be explained by their phosphorylation activities on the HBV core protein as the over-expression of these two kinases had no detectable effects on HBV core protein phosphorylation in vivo and their mutants that lacked the kinase activity could still suppress HBV DNA replication. Thus, these findings demonstrate a negative role of SRPK1 and SRPK2 in the regulation of HBV replication through a mechanism not involving the phosphorylation of the core protein

Fabrication and Characterization of In Situ Synthesized SiC/Al Composites by Combustion Synthesis and Hot Press Consolidation Method

The in situ SiC/Al composites were fabricated in Al-Si-C systems with different Si/C mass ratios and holding time by the method of combustion synthesis and hot press consolidation. The influences of Si/C mass ratio and holding time on the phase constitution, microstructure, and hardness of the composites were investigated. The results indicate that the increase of Si/C mass ratio leads to more uniform size distribution of the SiC particles in the Al matrix. Moreover, by improving the Si/C mass ratio from 4 : 1 to 5 : 1, the maximum size of SiC particle was reduced from 4.1 μm to 2.0 μm. Meanwhile, the percentage of submicroparticles was increased from 22% to 63%, and the average hardness value of the composites was increased by 13%. In addition, when the holding time is set to be fifteen minutes, the Al4C3 phase did not exist in the composites because of its total reactions with Si atoms to form SiC particles, and the average hardness value was 73.8 HB

Annual surveys for point-prevalence of healthcare-associated infection in a tertiary hospital in Beijing, China, 2012-2014

Background: This study aimed to investigate the prevalence of healthcare-associated infection (HAI) in the China-Japan Friendship Hospital, a tertiary level hospital in Beijing, China. Methods: We defined HAI using the criteria established by the Ministry of Health of the People's Republic of China. Three cross-sectional surveys were conducted from 2012 to 2014. Inpatients who had been hospitalized for at least 48 h were surveyed. Information on HAI prevalence, isolated pathogens and use of antibiotics were collected. Logistic regression models were used to assess the associations between HAI and potential risk factors. Results: During three cross-sectional surveys, a total number of 4,029 patients were included (1,233 patients in 2012, 1,220 patients in 2013 and 1,576 patients in 2014). The overall prevalence of patients with HAI was 3.6 % (95 % confidence interval (CI) 3.1 %-4.2 %). Respiratory tract infections were the most common type (64.7 %) of HAIs, followed by urinary tract infections (12.6 %) and bloodstream infections (5.4 %). HAI occurrences were significantly associated with male sex (odds ratio (OR) = 2.25, 95 % CI 1.53-3.32), age over 85 years (OR = 4.74, 95 % CI 2.54-8.83), hospitalization in the intensive care units (ICUs) (OR = 2.42, 95 % CI 1.31-4.49), indwelling urinary catheter (OR = 4.21, 95 % CI 2.46-7.20) and mechanical ventilation (OR = 2.31, 95 % CI 1.30-4.09). Gram-negative bacteria were found to be the most isolated pathogens (67.1 %), with gram-positive bacteria and fungi accounted for 20.3 % and 10.5 %, respectively. Antibiotics were administered to 34.3 % of the included patients over the study period. Conclusions: The overall HAI prevalence in our hospital is similar to previous studies that were conducted in other areas of China, and the respiratory tract infection should be the priority in HAI reduction control within China. We should focus HAI reduction efforts on patients with advanced age, hospitalization in the ICU and indwelling devices.SCI(E)[email protected]

Distilling Temporal Knowledge with Masked Feature Reconstruction for 3D Object Detection

Striking a balance between precision and efficiency presents a prominent challenge in the bird's-eye-view (BEV) 3D object detection. Although previous camera-based BEV methods achieved remarkable performance by incorporating long-term temporal information, most of them still face the problem of low efficiency. One potential solution is knowledge distillation. Existing distillation methods only focus on reconstructing spatial features, while overlooking temporal knowledge. To this end, we propose TempDistiller, a Temporal knowledge Distiller, to acquire long-term memory from a teacher detector when provided with a limited number of frames. Specifically, a reconstruction target is formulated by integrating long-term temporal knowledge through self-attention operation applied to feature teachers. Subsequently, novel features are generated for masked student features via a generator. Ultimately, we utilize this reconstruction target to reconstruct the student features. In addition, we also explore temporal relational knowledge when inputting full frames for the student model. We verify the effectiveness of the proposed method on the nuScenes benchmark. The experimental results show our method obtain an enhancement of +1.6 mAP and +1.1 NDS compared to the baseline, a speed improvement of approximately 6 FPS after compressing temporal knowledge, and the most accurate velocity estimation

SFCNeXt: a simple fully convolutional network for effective brain age estimation with small sample size

Deep neural networks (DNN) have been designed to predict the chronological age of a healthy brain from T1-weighted magnetic resonance images (T1 MRIs), and the predicted brain age could serve as a valuable biomarker for the early detection of development-related or aging-related disorders. Recent DNN models for brain age estimations usually rely too much on large sample sizes and complex network structures for multi-stage feature refinement. However, in clinical application scenarios, researchers usually cannot obtain thousands or tens of thousands of MRIs in each data center for thorough training of these complex models. This paper proposes a simple fully convolutional network (SFCNeXt) for brain age estimation in small-sized cohorts with biased age distributions. The SFCNeXt consists of Single Pathway Encoded ConvNeXt (SPEC) and Hybrid Ranking Loss (HRL), aiming to estimate brain ages in a lightweight way with a sufficient exploration of MRI, age, and ranking features of each batch of subjects. Experimental results demonstrate the superiority and efficiency of our approach.Comment: This paper has been accepted by IEEE ISBI 202

Preparation of polyvinyl alcohol/graphene oxide composites and their adsorption properties

The polyvinyl alcohol/graphene oxide (PVA/GO) hydrogel was prepared. It was confirmed that the adsorption performance of polyvinyl alcohol/graphene oxide hydrogel composite material was improved, and it does not cause secondary pollution. According to adsorption experiments, it was found that PVA/ GO adsorbent with a content of 30 % graphene oxide has the best comprehensive performance. The suitable environment of adsorption was under 25°C, 12-18 h for adsorption time and acidic conditions. The suitable adsorbent dosage was 0.3g and the suitable concentration of the dye was 10 mg/LThe authors gratefully acknowledge the financial support of the Shaoxing Public Welfare Project (Grant No. 2017B70042), and the International Science and Technology Cooperation Project of Shaoxing University (Grant No. 2019LGGH1004)Postprint (published version