ChatGPT Is A User-Generated Knowledge-Sharing Killer

Large Language Models (LLMs), e.g., ChatGPT, is expected to reshape a broad spectrum of domains. This study examines the impact of ChatGPT on question aksing in Q&A communitits via the natural experiment. Safe-guided by supporting evidence of parallel trends, a difference-in-difference (DID) analysis suggests the launching trigger an average 2.6% reduction of question-asking on Stack Overflow, confirming a lower-search-cost-enabled substitution. Our further analysis suggests that, this substitution effect has resulted in more longer, less readable and less cognitive and hence more sophisticated questions on average. Finally, the insignificant change in the score given by viewers per question suggests no improvement in the question quality and decreased platform-wide engagement. Our moderation analysis further ascertain the types of individuals who are more susceptible to ChatGPT. Taken together, our paper suggests LLMs may threaten the survival of user-generated knowledge-sharing communities, which may further threaten the sustainable learning and long-run improvement of LLMs

SMA observations of C2H in High-Mass Star Forming Regions

C$_2$H is a representative hydrocarbon that is abundant and ubiquitous in the interstellar medium (ISM). To study its chemical properties, we present Submillimeter Array (SMA) observations of the C$_2$H $N=3-2$ and HC$_3$N $J=30-29$ transitions and the 1.1 mm continuum emission toward four OB cluster-forming regions, AFGL 490, ON 1, W33 Main, and G10.6-0.4, which cover a bolometric luminosity range of $\sim$10$^3$--10$^6$ $L_{\odot}$. We found that on large scales, the C$_2$H emission traces the dense molecular envelope. However, for all observed sources, the peaks of C$_2$H emission are offset by several times times 10$^4$ AU from the peaks of 1.1 mm continuum emission, where the most luminous stars are located. By comparing the distribution and profiles of C$_2$H hyperfine lines and the 1.1 mm continuum emission, we find that the C$_2$H column density (and abundance) around the 1.1 mm continuum peaks is lower than those in the ambient gas envelope. Chemical models suggest that C$_2$H might be transformed to other species owing to increased temperature and density; thus, its reduced abundance could be the signpost of the heated molecular gas in the $\sim$10$^4$ AU vicinity around the embedded high-mass stars. Our results support such theoretical prediction for centrally embedded $\sim10^3$--$10^6L_{\odot}$ OB star-forming cores, while future higher-resolution observations are required to examine the C$_2$H transformation around the localized sites of high-mass star formation.Comment: 10 pages, 6 figures. ApJ accepted. Comments welcom

Automatic Estimation of Urban Waterlogging Depths from Video Images Based on Ubiquitous Reference Objects

Video supervision equipment, which is readily available in most cities, can record the processes of urban floods in video form. Ubiquitous reference objects, which often appear in videos, can be used to indicate urban waterlogging depths. This makes video images a valuable data source for obtaining waterlogging depths. However, the urban waterlogging information contained in video images has not been effectively mined and utilized. In this paper, we present a method to automatically estimate urban waterlogging depths from video images based on ubiquitous reference objects. First, reference objects from video images are detected during the flooding and non-flooding periods using an object detection model with a convolutional neural network (CNN). Then, waterlogging depths are estimated using the height differences between the detected reference objects in these two periods. A case study is used to evaluate the proposed method. The results show that our proposed method could effectively mine and utilize urban waterlogging depth information from video images. This method has the advantages of low economic cost, acceptable accuracy, high spatiotemporal resolution, and wide coverage. It is feasible to promote this proposed method within cities to monitor urban floods

Gonadal, Not Maternal, Acquisition of Duplicated <i>pax6</i> Orthologs in <i>Megalobrama Amblycephala</i>

The highly conserved transcription factor Pax6 is involved in the development of the eyes, brain, and pancreas in vertebrates and invertebrates, whereas the additional expression pattern in other organs is still elusive. In this study, we cloned and characterized two pax6 homologs in blunt snout bream (Megalobrama amblycephala), named Mapax6a and Mapax6b. The protein alignment and phylogenetic tree showed that Mapax6a and Mapax6b were highly conserved compared with their counterparts in other species. Genomic information analysis revealed that the synteny conservation of Wilms tumor, Aniridia, genitourinary abnormalities, and mental retardation loci was also maintained in this species. By reverse transcription polymerase chain reaction, the expression of Mapax6a was later than that of Mapax6b which was found in the blastula stage, while the expression of Mapax6a started from the somite stage, and both of them persisted in a subsequent stage during the embryonic development. By RNA and protein detection, Mapax6a and Mapax6b were detected in the eye and brain as canonic patterns, and most importantly, they were also enriched in germ cells of the testis and ovary. Therefore, our findings validate the duplication of pax6 in fish, confirm the classical expression patterns in the brain and eye, and, for the first time, present a new acquisition of Mapax6a and Mapax6b in gonadal germ cells in particular. Therefore, our results enrich the expression pattern and evolutionary relationship of pax6 by suggesting that duplicated Mapax6 is involved in gametogenesis in Megalobrama amblycephala

Hybridization of Nanodiamond and CuFe-LDH as Heterogeneous Photoactivator for Visible-Light Driven Photo-Fenton Reaction: Photocatalytic Activity and Mechanism

Establishing a heterojunction for two kinds of semiconductor catalysts is a promising way to enhance photocatalytic activity. In this study, nanodiamond (ND) and CuFe-layered double hydroxide (LDH) were hybridized by a simple coprecipitation method as a novel heterojunction to photoactivate H2O2. The ND/LDH possessed a hydrotalcite-like structure, large specific surface area (SBET = 99.16 m2/g), strong absorption of visible-light and low band gap (Eg = 0.94 eV). Under the conditions of ND/LDH dosage 0.0667 g/L, H2O2 concentration 19.6 mmol/L, and without initial pH adjustment, 93.5% of 10 mg/L methylene blue (MB) was degraded within 120 min, while only 78.3% of MB was degraded in the presence of LDH instead of ND/LDH. The ND/LDH exhibited excellent stability and maintained relatively high activity, sufficient to photoactivate H2O2 even after five recycles. The mechanism study revealed that in the heterojunction of ND/LDH, the photoelectrons transferred from the valence band of LDH (Cu/Fe 3d t2g) to the conduction band of LDH (Cu/Fe 3d eg) could spontaneously migrate onto the conduction band of ND, promoting the separation of photo-induced charges. Thus, the photoelectrons had sufficient time to accelerate the redox cycles of Cu3+/Cu2+ and Fe3+/Fe2+ to photoactivate H2O2 to produce hydroxyl radicals, resulting in excellent photo-Fenton efficiency on MB degradation

A novel quantified bitterness evaluation model for traditional Chinese herbs based on an animal ethology principle

Traditional Chinese herbs (TCH) are currently gaining attention in disease prevention and health care plans. However, their general bitter taste hinders their use. Despite the development of a variety of taste evaluation methods, it is still a major challenge to establish a quantitative detection technique that is objective, authentic and sensitive. Based on the two-bottle preference test (TBP), we proposed a novel quantitative strategy using a standardized animal test and a unified quantitative benchmark. To reduce the difference of results, the methodology of TBP was optimized. The relationship between the concentration of quinine and animal preference index (PI) was obtained. Then the PI of TCH was measured through TBP, and bitterness results were converted into a unified numerical system using the relationship of concentration and PI. To verify the authenticity and sensitivity of quantified results, human sensory testing and electronic tongue testing were applied. The quantified results showed a good discrimination ability. For example, the bitterness of Coptidis Rhizoma was equal to 0.0579 mg/mL quinine, and Nelumbinis Folium was equal to 0.0001 mg/mL. The validation results proved that the new assessment method for TCH was objective and reliable. In conclusion, this study provides an option for the quantification of bitterness and the evaluation of taste masking effects. KEY WORDS: Bitter, Quantification, Two-bottle preference test, Quinine, Electronic tongue, Human sensory evaluatio

Comprehensive virome analysis reveals the complexity and diversity of the viral spectrum in pediatric patients diagnosed with severe and mild hand foot-and-mouth disease

The management of hand-foot-and-mouth disease(HFMD) epidemic is difficult due to the frequent emergence of non-EV71 and non-CVA16 enteroviruses and some cases testing negative for HFMD-associated causative agents. To clarify the virus spectrum of mild and severe HFMD, a comprehensive virome analysis of 238 samples was performed using next-generation sequencing (NGS). The data revealed total thirteen mammalian- and plant virus families and diverse viral populations including enteroviruses, common respiratory viruses, diarrhea-related viruses, plant viruses and anelloviruses. A total of 18 viruses from 7 virus families were identified in severe cases, versus 37 viruses from 12 virus families in mild cases. Moreover, complicated mixed-infections of enteroviruses with common respiratory viruses were mainly found in severe cases(P = 0.013), while diarrhea related viruses were mainly found in mild cases(P &lt; 0.001). This study provides the preliminary understanding of viromes both in mild and severe cases, which may benefit the detection of etiologic agents and prevention of HFMD.</p

Effect of Kinesio taping on Pregnancy-related low back pain: A protocol for systematic review and meta-analysis.

BackgroundPregnancy-related low back pain (PLBP) affects the daily living activities of pregnant women, even leading to fetal agitation and threatened abortion. Kinesio taping (KT) can improve the circulation of blood and provide elastic supports, which is a reliable method to treat low back pain. At present, although many studies have been published on the effects of KT on PLBP, the results are inconsistent, and some studies even report that KT does not affect PLBP. there is still a lack of high-level clinical evidence for the treatment of PLBP with KT. Therefore, this study proposes a protocol for a systematic review and meta-analysis of published Randomized Controlled Trials (RCTs) to evaluate the efficacy and safety of KT for PLBP.MethodsThis protocol is guided by the Preferred Reporting Items for Systematic Reviews and Meta-Analyses Protocols. We will search the following database sources of the RCTs: PubMed, the Cochrane Library, EMBASE, Web of Science, Chinese Biomedical Literature Database (CBM), Chinese National Knowledge Infrastructure Database (CNKI), Chinese Science, and the Wanfang Database. From the establishment of the database to April 2021. The retrieval word adopts the combination of theme words and free words. Take "Kinesiotape, Tape Athletic, Orthotic Tape, Athletic Tape, Pregnancy, Pregnancies, Gestation, low back pain" as a term for retrieval. Two independent investigators will conduct an electronic literature search, study selection, data extraction, and quality assessment to summarize and evaluate the efficacy of KT in the treatment of PLBP. Retrospective trials are not included, and the risk of bias will be assessed using the Cochrane bias risk tool. All data analysis will be conducted using Revman5.3 software.ResultsQuality outcomes in systematic review studies depend on inclusion and search criteria to obtain high-quality data, as well as how the data are processed and interpreted. Among the results, this study will objectively and comprehensively evaluate the efficacy and safety of the randomized controlled trial of KT in the treatment of PLBP, and make a detailed analysis of the effect of KT in the treatment of PLBP. The results will be analyzed by the Visual Analogue Scale of Pain and the Roland Morris Dysfunction Questionnaire. If applicable, a subgroup analysis will also be performed, which will be grouped according to the duration of pregnancy, grade of pain, etc. Finally, the results are submitted to a peer-reviewed journal for publication.ConclusionBased on the results, this study will analyze and summarize the effect of KT on improving PLBP. It includes whether KT can improve the pain and lumbar function of PLBP, or it has adverse effects and reactions on pregnant women, then analysis and interpretation of other related issues. It is expected that the results of this study will provide a reference to the method and time of taping for clinical staff, as well as high-quality evidence to resolve the effect of KT on low back pain and provide corresponding guidance for pregnant women with low back pain. It aims to improve the status of low back pain in pregnant women and improve their physical health.Protocol registration numberPROSPERO CRD42021250373; https://clinicaltrials.gov/

The Delineation and Ecological Connectivity of the Three Parallel Rivers Natural World Heritage Site

Landscape connectivity refers to the degree of continuity between the spatially structured units of a landscape. Ecological connectivity can characterise the degree to which ecological functional areas are connected in terms of function and ecological processes. In this study, the landscape pattern index and ecosystem service values were used to evaluate the ecological functional resistance of each landscape type, taking the Three Parallel Rivers Natural World Heritage Site as an example and the habitat distribution and population size of the Yunnan snub-nosed monkey as a reference. The minimum cost distance model, combined with the barrier impact index (BEI) and ecological connectivity index (ECI), was used to determine the degree of barrier impact on the study area and the ecological connectivity of the core reserve of the heritage site in both 2000 and 2020. The resistances of the different land types and landscape heterogeneity to the ecological function of species migration between the core protected areas of the heritage site were, in descending order, those of the forest, shrubs and grass, water, unused land, cultivated land, and built-up land. In 2020, the study area had a large BEI, with areas such as built-up areas, major roads, the sides of large rivers, and arable land being significant contributors to the blockage of landscape connectivity. The overall landscape connectivity in the study area was generally low, with clear spatial differentiation and a three-column parallel distribution pattern influenced by the topography and landscape. With the adjustment of the core reserve boundaries of the heritage site, the proportion of areas with high connectivity (ECI = 4–5) increased from 11.31% in 2000 to 34.36% in 2020. This increased landscape connectivity was conducive to the migration and reproduction of large terrestrial animals, such as the Yunnan snub-nosed monkey, with increasing numbers of populations and individuals. This study provides theoretical and methodological insights into the delineation and conservation of natural heritage sites and landscape connectivity