80 research outputs found
RAFT based wireless blockchain networks in the presence of malicious jamming
Blockchain shows great potential to be applied in wireless IoT ecosystems for establishing the trust and consensus mechanisms without central authority’s involvement. Based on RAFT consensus mechanism, this paper investigates the security performance of wireless blockchain networks in the presence of malicious jamming. We first map and model the blockchain transaction as a wireless network composed of uplink and downlink transmissions by assuming the follower nodes’ position as a Poisson Point Process (PPP) with selected leader location. The probability of achieving successful blockchain transactions is derived and verified by extensive simulations. The results provide analytical guidance for the practical deployment of wireless blockchain networks
Clinicopathological Features and Prognostic Factors of Colorectal Neuroendocrine Neoplasms
Background. Limited research is available regarding colorectal NENs and the prognostic factors remain controversial. Materials and Methods. A total of 68 patients with colorectal NENs were studied retrospectively. Clinical characteristics and prognosis between colonic and rectal NENs were compared. The Cox regression models were used to evaluate the predictive capacity. Results. Of the 68 colorectal NENs patients, 43 (63.2%) had rectal NENs, and 25 (36.8%) had colonic NENs. Compared with rectal NENs, colonic NENs more frequently exhibited larger tumor size (P<0.0001) and distant metastasis (P<0.0001). Colonic NENs had a worse prognosis (P=0.027), with 5-year overall survival rates of 66.7% versus 88.1%. NET, NEC, and MANEC were noted in 61.8%, 23.5%, and 14.7% of patients, respectively. Multivariate analyses revealed that tumor location was not an independent prognostic factor (P=0.081), but tumor size (P=0.037) and pathological classification (P=0.012) were independent prognostic factors. Conclusion. Significant differences exist between colonic and rectal NENs. Multivariate analysis indicated that tumor size and pathological classification were associated with prognosis. Tumor location was not an independent factor. The worse outcome of colonic NENs observed in clinical practice might be due not only to the biological differences, but also to larger tumor size in colonic NENs caused by the delayed diagnosis
Ambient temperature regulates root circumnutation in rice through the ethylene pathway: transcriptome analysis reveals key genes involved
Plant roots are constantly prepared to adjust their growth trajectories to avoid unfavorable environments, and their ability to reorient is particularly crucial for survival. Under laboratory conditions, this continuous reorientation of the root tip is manifested as coiling or waving, which we refer to as root circumnutation. However, the effect of ambient temperature (AT) on root circumnutation remains unexplored. In this study, rice seedlings were employed to assess the impact of varying ATs on root circumnutation. The role of ethylene in mediating root circumnutation under elevated AT was examined using the ethylene biosynthesis inhibitor aminooxyacetic acid (AOA) and the ethylene perception antagonist silver thiosulfate (STS). Furthermore, transcriptome sequencing, weighted gene co-expression network analysis, and real-time quantitative PCR were utilized to analyze gene expressions in rice root tips under four distinct treatments: 25°C, 35°C, 35°C+STS, and 35°C+AOA. As a result, genes associated with ethylene synthesis and signaling (OsACOs and OsERFs), auxin synthesis and transport (OsYUCCA6, OsABCB15, and OsNPFs), cell elongation (OsEXPAs, OsXTHs, OsEGL1, and OsEXORDIUMs), as well as the inhibition of root curling (OsRMC) were identified. Notably, the expression levels of these genes increased with rising temperatures above 25°C. This study is the first to demonstrate that elevated AT can induce root circumnutation in rice via the ethylene pathway and proposes a potential molecular model through the identification of key genes. These findings offer valuable insights into the growth regulation mechanism of plant roots under elevated AT conditions
Chronic exposure to low-level lipopolysaccharide dampens influenza-mediated inflammatory response via A20 and PPAR network
Influenza A virus (IAV) infection leads to severe inflammation, and while epithelial-driven inflammatory responses occur via activation of NF-κB, the factors that modulate inflammation, particularly the negative regulators are less well-defined. In this study we show that A20 is a crucial molecular switch that dampens IAV-induced inflammatory responses. Chronic exposure to low-dose LPS environment can restrict this excessive inflammation. The mechanisms that this environment provides to suppress inflammation remain elusive. Here, our evidences show that chronic exposure to low-dose LPS suppressed IAV infection or LPS stimulation-induced inflammation in vitro and in vivo. Chronic low-dose LPS environment increases A20 expression, which in turn positively regulates PPAR-α and -γ, thus dampens the NF-κB signaling pathway and NLRP3 inflammasome activation. Knockout of A20 abolished the inhibitory effect on inflammation. Thus, A20 and its induced PPAR-α and -γ play a key role in suppressing excessive inflammatory responses in the chronic low-dose LPS environment
Is Positive LGBQ Identity A Protective Factor for Depressive Symptoms Among Queer Young Adults?
The present study examined how levels of positive LGBQ identity varied based on different demographic factors as well as investigated the potential protective role of positive LGBQ identity on depression among queer young adults. A cross-sectional study was conducted on a sample of 79 queer participants (aged 18-28). Regression analysis was employed with positive LGBQ identity and depression as outcome variables, respectively. Findings suggest younger ages and higher education were associated with higher levels of positive LGBQ identity. Positive LGBQ identity was positively associated with depressive symptoms. This research expands current understanding by investigating unexplored demographic factors and focusing on the separate and combined roles played by multiple aspects of positive LGBQ identity. Study implications include the potential effectiveness of interventions nurturing positive LGBQ identity to reduce depressive symptoms among queer young adults and underscores the significance of environments that foster positive LGBQ identity development
Modeling of Daytime and Nighttime Surface Urban Heat Island Distribution Combined with LCZ in Beijing, China
Along with urbanization, surface urban heat island (SUHI) has attracted more attention. Due to the lack of perspective of spatial heterogeneity in relevant studies, it is difficult to propose specific strategies to alleviate the SUHI. This study discusses the impact of spatial heterogeneity on the day and night SUHI by taking one day and night in Beijing as an example, and uses it to improve the efficiency of SUHI simulation for related planning. This study, based on the local climate zone (LCZ), deeply discusses the relationship between urban morphology and the SUHI. Then, an artificial neural network (ANN) model with the LCZ is developed to predict the distribution of the SUHI. The results show that: (1) In summer, the general SUHI intensity distribution patterns are compact zone > large low-rise zone > open zone and medium floor zone > low floor zone > high floor zone. (2) Building density and albedo in dense areas are higher correlated with the SUHI than open areas. The building height has a significant negative correlation with the SUHI in high-rise zone, but has a positive correlation in middle and low floors. (3) The LCZ improves the overall accuracy of the ANN model, especially the simulation accuracy in the daytime. In terms of regions, LCZ2, LCZ8, and LCZ10 are improved to a higher degree. This study is helpful to formulate the SUHI mitigation strategies of “adapting to the conditions of the LCZ” and provide reference for improving the sustainable development of the urban thermal environment
Modeling of Daytime and Nighttime Surface Urban Heat Island Distribution Combined with LCZ in Beijing, China
Along with urbanization, surface urban heat island (SUHI) has attracted more attention. Due to the lack of perspective of spatial heterogeneity in relevant studies, it is difficult to propose specific strategies to alleviate the SUHI. This study discusses the impact of spatial heterogeneity on the day and night SUHI by taking one day and night in Beijing as an example, and uses it to improve the efficiency of SUHI simulation for related planning. This study, based on the local climate zone (LCZ), deeply discusses the relationship between urban morphology and the SUHI. Then, an artificial neural network (ANN) model with the LCZ is developed to predict the distribution of the SUHI. The results show that: (1) In summer, the general SUHI intensity distribution patterns are compact zone > large low-rise zone > open zone and medium floor zone > low floor zone > high floor zone. (2) Building density and albedo in dense areas are higher correlated with the SUHI than open areas. The building height has a significant negative correlation with the SUHI in high-rise zone, but has a positive correlation in middle and low floors. (3) The LCZ improves the overall accuracy of the ANN model, especially the simulation accuracy in the daytime. In terms of regions, LCZ2, LCZ8, and LCZ10 are improved to a higher degree. This study is helpful to formulate the SUHI mitigation strategies of “adapting to the conditions of the LCZ” and provide reference for improving the sustainable development of the urban thermal environment
Spatial Association Rules and Thermal Environment Differentiation Evaluation of Local Climate Zone and Urban Functional Zone
Urban heat islands (UHIs) caused by urbanization have become a major issue affecting the sustainable development of the ecological environment. The distribution of UHIs is mainly affected by the reflection and transmission of heat radiation caused by differences in urban spaces, and the anthropogenic heat emissions caused by social activities. At present, the research on the urban thermal environment involves two spatial classification systems: local climate zone (LCZ), based on urban morphology and spatial patterns; and urban functional zone (UFZ), based on socio-economic activities. It is not clear whether there are association rules between these two systems in different cities. Against this background, this study explores the association rules between the UFZ and LCZ classification systems using the selected Chinese cities in different regions as typical examples. Our results confirm that there are common association rules from UFZ to LCZ, as the form of buildings is greatly influenced by the types of functional areas in urban construction. Specifically, the medical zone corresponds to the compact mid-rise zone (LCZ2); the business service area and the office area also correspond to the compact zone (LCZ1-LCZ3); and the industrial area corresponds to the compact low-rise zone (LCZ3). These functional zones have the same association rules in different cities. The cross-regional mining of the relationship between different urban functional systems will help to coordinate different planning departments and carry out the integration of multiple spatial plans. Furthermore, we found that LCZ has a better differentiation effect on the surface temperature through our comparison research, which makes it more suitable as a reference for research on the thermal environment and the heat island effect
Battle Against Effects of Discrimination with Belonging and Support: �Comparing Mental Health Risk and Protective Factors Among Sexual and Gender Minority Youth�
Sexual and gender minority (SGM) youth face elevated mental health risks. At the same time, research seldomly differentiates between gender minority (GM) and sexual minority (SM) experiences. The current study examines identity-based discrimination and the protective roles of parent support and school belonging on the mental health (i.e., anxiety, depression, and suicide ideation and attempt) of 2,495 SM and GM youth. Using structural equation modeling with SM and GM youth in two separate models, results indicate that experiences of discrimination based on sexual orientation, gender, disability, and immigration status were related to higher mental health risks. Such associations were not observed for discrimination based on race/ethnicity. School belonging was associated with lower mental health risks for both SM and GM youth, while the protective role of parental support was only observed for SM youth. Our findings point to varied experiences among SGM youth with diverse identities, as well as distinct experiences for SM and GM youth, suggesting tailored intervention and prevention approaches for each group
Preparation of PVA/waste oyster shell powder composite as an efficient adsorbent of heavy metals from wastewater
The accumulation of discarded mollusk shells has occupied a large land area and caused severe environmental pollution problems. Discarded mollusk shells are mainly composed of calcium carbonate and therefore can be used for the removal of heavy metals from the contaminated aquatic environment. Theoretically, shells with a smaller powder size have a higher adsorption capacity for heavy metal ions. However, the agglomeration and the outflow of small particles limit the applications of mollusk shells in water treatment practices. To overcome the shortcomings of mollusk shells in heavy metals adsorptions, a polymer composite material comprising poly (vinyl alcohol)/oyster shell powder (PVA-OSP) was prepared with the solution casting method for the adsorption of heavy metal ions from wastewater. The structures and the heavy metal adsorption properties of the oyster shell powder (OSP) and the composite PVA-OSP were studied and compared. Analysis results of XRD and FT-IR showed a successful combination of OSP and PVA by a chemical cross-linking modified with sodium silicate. The composite PVA-OSP has good thermal stability for common adsorption processes. The adsorption results showed that the adsorption capacity of the PVA-OSP composite for both Cu2+ and Cd2+ was much higher than that of the OSP. The adsorptions of Cu2+ and Cd2+ on the OSP followed the pseudo-second-order kinetic model as well as the Temkin and Freundlich isotherm model. Comparatively, the adsorptions of heavy metal cations on the PVA-OSP followed the pseudo-first-order kinetic model as well as the Temkin and Langmuir isotherm model. In conclusion, this study showed that the PVA-OSP composite materials may be useful in the treatment of wastewater polluted by heavy metals
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