Success for whom? A probe into user experiences of online communities of interests

The online community (OC) plays an important role in modern people's daily lives. Successful OCs can meet users' needs for interest, relationship, fantasy, or transaction, and can create information value, experiential value, social value, or transaction value for the organizers. However, it's not easy to explain why some OCs are successful and some are not. OC success has been examined by researchers from different perspectives, such as the social perspective, the system perspective, or the organizer perspective. Studies from these perspectives have suggested that users play a key role in the success of an OC. Yet, understanding of user experiences in OCs from their own perspective was insufficient and fragmented. Most studies often presumed that the users share the same goal and perspective as organizers regarding OC success, while some empirical findings suggested otherwise. The research aims to contribute to a deeper understanding of OC success from the user perspective. Emphasizing users' active and subjective participation, this research applied design probe to delve deeper and closer into user activities, thoughts, and emotions that traditional research methods were rarely able to. The research yielded rich and texturized information on user experiences about OCs of interests. The research findings showed: 1) the user experience of OCs of interests is an interactive combination of various OCs, offline events, and activities around their own interests or goals, instead of an isolated experience in each OC as previous studies tend to consider; 2) users' perceived success of an OC is also based on the holistic experience around their interests or goals, instead of based on a single OC; 3) online and offline activities are interconnected in the building of users’ social relationships. The research suggests more researches of OC success from the user perspective, separate from the organizer perspective. The research also suggests future studies to aim at a clearer definition and measurement of OC success from the user perspective

Cholinergic signal activated renin angiotensin system associated with cardiovascular changes in the ovine fetus

Aim: Cholinergic regulation is important in the control of cardiovascular and endocrine responses. The mechanisms behind cardiovascular responses induced by cholinergic activation are explored by studying hormonal systems, including renin-angiotensin and vasopressin (VP). Results: In chronically prepared fetal sheep, intravenous infusion of the cholinergic agonist carbachol increased fetal systolic, diastolic, and mean arterial pressure accompanied with bradycardia at near-term. Although intravenous administration of carbachol had no effect on plasma VP concentrations, this agonist increased angiotensin I and angiotensin II levels in fetal plasma. Fetal blood values, including sodium, osmolality, nitric oxide, hemoglobin, and hematocrit were unchanged by intravenous carbachol. Conclusion: Cholinergic activation by carbachol controls fetal blood pressure and heart rate in utero. An over-activated fetal renin-angiotensin-system (RAS) is associated with changes in vascular pressure following intravenous administration of carbachol, indicating that the cholinergic stimulation-mediated hormonal mechanism in the fetus might play a critical role in the regulation of cardiovascular homeostasis.Peer Reviewe

Identification and expression analysis of EDR1-like genes in tobacco (Nicotiana tabacum) in response to Golovinomyces orontii

ENHANCED DISEASE RESISTANCE1 (EDR1) encodes a Raf-like mitogen-activated protein kinase, and it acts as a negative regulator of disease resistance and ethylene-induced senescence. Mutations in the EDR1 gene can enhance resistance to powdery mildew both in monocotyledonous and dicotyledonous plants. However, little is known about EDR1-like gene members from a genome-wide perspective in plants. In this study, the tobacco (Nicotiana tabacum) EDR1-like gene family was first systematically analyzed. We identified 19 EDR1-like genes in tobacco, and compared them to those from Arabidopsis, tomato and rice. Phylogenetic analyses divided the EDR1-like gene family into six clades, among them monocot and dicot plants were respectively divided into two sub-clades. NtEDR1-1A and NtEDR1-1B were classified into clade I in which the other members have been reported to negatively regulate plant resistance to powdery mildew. The expression patterns of tobacco EDR1-like genes were analyzed after plants were challenged by Golovinomyces orontii, and showed that several other EDR1-like genes were induced after infection, as well as NtEDR1-1A and NtEDR1-1B. Expression analysis showed that NtEDR1-13 and NtEDR1-16 had exclusively abundant expression patterns in roots and leaves, respectively, and the remaining NtEDR1-like members were actively expressed in most of the tissue/organ samples investigated. Our findings will contribute to further study of the physiological functions of EDR1-like genes in tobacco

Heterogeneous Urban Thermal Contribution of Functional Construction Land Zones: A Case Study in Shenzhen, China

Anthropogenic interferences through various intensive social-economic activities within construction land have induced and strengthened the Urban Heat Island (UHI) effects in global cities. Focused on the relative heat effect produced by different social-economic functions, this study established a general framework for functional construction land zones (FCLZs) mapping and investigated their heterogeneous contribution to the urban thermal environment, and then the thermal responses in FCLZs with 12 environmental indicators were analyzed. Taking Shenzhen as an example city, the results show that the total contribution and thermal effects within FCLZs are significantly different. Specifically, the FCLZs contribution to UHI regions highly exceeds the corresponding proportions of their area. The median warming capacity order of FCLZs is: Manufacture function (3.99 °C) > Warehousing and logistics function (3.69 °C) > Street and transportation function (3.61 °C) > Business services function (3.06 °C) > Administration and public services function (2.54 °C) > Green spaces and squares function (2.40 °C) > Residential function (2.21 °C). Both difference and consistency coexist in the responses of differential surface temperature (DST) to environmental indicators in FCLZs. The thermal responses of DST to biophysical and building indicators in groups of FCLZs are approximately consistent linear relationships with different intercepts, while the saturation effects shown in location and social-economic indicators indicate that distance and social-economic development control UHI effects in a non-linear way. This study could extend the understanding of urban thermal warming mechanisms and help to scientifically adjust environmental indicators in urban planning

The Synthesis Process and Thermal Stability of V₂C MXene

The effect of etching solution on the synthesis process of two-dimensional vanadium carbide (V2C MXene) was researched. Three etching solutions were used to etch ternary carbide V2AlC at 90 °C. The three solutions were: lithium fluoride + hydrochloric acid (LiF + HCl), sodium fluoride + hydrochloric acid (LiF + HCl), and potassium fluoride + hydrochloric acid (KF + HCl). It was found that only NaF + HCl solution was effective for synthesizing highly pure V2C MXene. The existence of sodium (Na+) and chloridion (Cl−) in etching solution was essential for the synthesis. The thermal stability of the as-prepared V2C MXene in argon or air was studied. From thermogravimetry and differential thermal analysis, V2C MXene was found to be stable in argon atmosphere at a temperature of up to 375 °C. As the temperature increased, V2C MXene was gradually oxidized to form nanoparticles composed of vanadium trioxide (V2O3) and a part of V2C MXene was broken and transformed to vanadium carbide (V8C7) at 1000 °C. In air atmosphere, V2C MXene was stable at 150 °C. At 1000 °C, V2C MXene was oxidized to form vanadium pentoxide (V2O5)

Investigation of internal damage evolution in gneiss considering water softening

Abstract In soft rock tunnels, there are often large deformations during construction, especially when the groundwater seepage and softens the surrounding rock. For achieving the purpose of studying the softening effect of water immersion on strength and stability of surrounding rock, 15 rock samples were selected for physical and mechanical tests under 5 conditions: natural state and free immersion for 1, 3, 6, and 9 months, and nuclear magnetic resonance technology(NMR) was also adopted to test the internal pore structure of specimens with different immersion durations, thus the micro structure features of the gneiss, such as the NMR relaxation time T2 spectrum distribution, porosity, and pore volume ratio of different pore sizes under water softening were then obtained. The NMR results shows that the longer the free immersion duration of the rock sample, the greater the porosity; at the same time, the number of micropores in the rock gradually decreases under the interaction of water and rock, and the mesopores increase slightly first and then decrease all the time. The number of macropores is gradually increasing. When the immersion duration is 6 months, the number of macropores begins to increase significantly, and the mechanical properties of the specimens begin to drop significantly. By 9 months, the proportion of macropores in the rock has reached 57.6%. The results showed that the number growth of macropores is the root cause of the macroscopic failure of rock sample. The study results have significance for on-site construction in water-rich areas