An online health-care community (OHC) is a novel channel through which doctors share medical or health-care knowledge with patients. While the sustainable development of an OHC relies on doctors' ...participation, we have limited information on how doctors can gain benefits from OHCs. In attempting to close this knowledge gap, we examine the determinants of social and economic returns of doctors at OHCs by extending the social exchange theory into the professional domain. The notion of professional capital, as a set of renewable resources for social professionals developed by good education within a territory of social practice, is introduced to understand the unique resources available to doctors for social exchange. Specifically, we examine the effects of status capital and decisional capital (two dimensions of professional capital) on doctors' social and economic returns. Moreover, we explore how such effects differ across different doctor groups. The results show that, in addition to the widespread pursuit of celebrity doctors (who can be recognized by their high status capital) offline, the doctor's decisional capital is also an important professional component in maintaining exchange returns at OHCs. This study provides empirical evidence of the relationship between professional capital and the exchange returns, and extends prior research on OHCs through a professional capital perspective with implications for theory and practice.
This study aims to address two research gaps in prior studies on knowledge sharing in virtual communities (VCs). First, prior studies have focused on knowledge sharing VCs with no explicit reward ...system, but VCs sharing knowledge based on a competition-based reward system (e.g., transactional VCs) have not been explored. Second, prior related studies have concentrated on the determinants of initial participation in sharing knowledge rather than sustained participation despite there being important distinctions between these two stages of participation behavior. In this study, we focus on understanding sustained participation in knowledge sharing in transactional VCs by drawing on expectancy-value theory and a social learning process. Considering that a social learning process is involved in maintaining sustained participation, we propose that task complexity and self-efficacy – two social learning factors – moderate the relationship between motivation and sustained participation. A field survey with 205 subjects in a transactional virtual community was conducted to test the research model. According to the findings, extrinsic and intrinsic motivations significantly influence sustained participation intention. A negative interaction effect between extrinsic motivation and task complexity, as well as positive interaction effect between intrinsic motivation and self-efficacy, was also observed. A non-linear interaction effect between intrinsic motivation and task complexity was also found. Study implications and future research directions are also discussed.
► Extrinsic motivation plays an important role in the TVC context. ► Task complexity weakens the effect of extrinsic motivation on intention. ► Self efficacy enhances the effect of intrinsic motivation on intention. ► The effect of intrinsic motivation is low under high level of task complexity.
Today, using elastography and ultrasound images is the best method for diagnosing breast cancer for dense tissues, especially for women under 30 years old, which is used to detect the exact border of ...masses. Besides, using quantitative microscopic criteria that are less tasteful seems to be useful in predicting the behavior of the tumor and its prognosis. Ki-67 is an antigen corresponding to a nuclear non-histone protein produced by cells in proliferative phases. In this article, ultrasound and elastography images of patients were collected, and breast masses were identified. The proposed algorithm includes pre-processing, feature extraction, and classification. To remove the speckle noise, two pre-processing steps are used, and after segmenting each data with its appropriate color channel, statistical features and features based on the morphology of suspicious areas are extracted. Also, sections of paraffin blocks of samples fixed in formalin were prepared and stained by immunohistochemical staining with Ki-67 monoclonal antibody, and the cell proliferation index was determined in the prepared slides. The relationship between Ki-67 positivity and microscopic grade was studied. The feature extraction results show that elastography is chosen as a more appropriate method than ultrasound due to the separation in terms of color channels. The most appropriate proposed combined methods, namely RBF-Kmeans, MLP-SCG, and RBF-SOM, have been used to classify features. The combined MLP-SCG classifier with an average accuracy of 96% and an average of 98% has improved significantly compared to other methods.
Drought is one of the major abiotic stress factors that affect grape growth and yield, which in turn negatively affects the grape and wine production industry. Developing effective approaches to ...improve grapevine tolerance to drought stress is a priority for viticulture. Strigolactones, a newly discovered class of carotenoid-derived phytohormones, have been found to participate in various physiological processes. Herein, the effect of strigolactones (SLs) on grape seedlings under drought stress was investigated. Two-year-old grape seedlings (Vitis vinifera L.) were sprayed with 3 doses of rac-GR24 (1 μM, 3 μM and 5 μM), a synthesized strigolactone, and then were subjected to 7% (w/v) polyethylene glycol (PEG-6000) to simulate the drought conditions. Synthetic GR24 treated plants showed higher tolerance to drought stress with regard to lower electrolyte leakage, stomatal opening, reactive oxygen species (ROS), and higher relative water content, chlorophyll content, photosynthesis rate and malondialdehyde (MDA) content. GR24 application also decreased the levels of indoleacetic acid (IAA) and zeatin riboside (ZR), while increasing the level of abscisic acid (ABA), both in the roots and leaves under drought stress. These results suggested that foliar application of GR24 could ameliorate the adverse effects of drought due to its regulation of stomatal closure through ABA or ROS, and modulation of chlorophyll components and photosynthesis, as well as activation of the antioxidant defense capacity. Cross-talk with other hormones, especially ABA, was also suggested to be one of the important mechanism during this process. This study contributes to our current understanding of GR24-induced drought tolerance in grapevines.
•GR24 pretreatment alleviates the adverse effects of drought stress in grape seedlings.•Under drought stress, GR24 could better induce the stomatal closure.•GR24 could modulate the chlorophyll components and dampened the decrease of photosynthesis induced by drought.•Cross-talk of SLs with other hormones, especially ABA, may be one of the important mechanism in drought response.•This is the first attempt for SLs to be used in horticultural fruit tree-grape.
By integrating social network theory and leader–member exchange (LMX) theory, we explore the effects of three types of social relationships on employee innovative behavior: weak ties outside the ...group, LMX, and strong ties within the group. The results from a sample in a high-tech firm showed that LMX fully mediated the positive relationship between out-group weak ties and innovative behavior. Furthermore, within-group strong ties negatively moderated the second stage of this indirect relationship, such that LMX was positively and significantly related to innovative behavior only when the number of within-group strong ties was low. The theoretical and practical implications of these findings are discussed.
Information systems professionals must pay attention to online customer retention. Drawing on the relationship marketing literature, we formulated and tested a model to explain B2C user repurchase ...intention from the perspective of relationship quality. The model was empirically tested through a survey conducted in Northern Ireland. Results showed that online relationship quality and perceived website usability positively impacted customer repurchase intention. Moreover, online relationship quality was positively influenced by perceived vendor expertise in order fulfillment, perceived vendor reputation, and perceived website usability, whereas distrust in vendor behavior negatively influenced online relationship quality. Implications of these findings are discussed.
The success of open source software (OSS) projects depends heavily on the voluntary participation of a large number of developers. To remain sustainable, it is vital for an OSS project community to ...maintain a critical mass of core developers. Yet, only a small number of participants (identified here as ‘‘joiners’’) can successfully socialize themselves into the core developer group. Despite the importance of joiners’ socialization behavior, quantitative longitudinal research in this area is lacking. This exploratory study examines joiners’ temporal socialization trajectories and their impacts on joiners’ status progression. Guided by social resource theory and using the growth mixture modeling (GMM) approach to study 133 joiners in 40 OSS projects, the authors found that these joiners differed in both their initial levels and their growth trajectories of socialization and identified four distinct classes of joiner socialization behavior. They also found that these distinct latent classes of joiners varied in their status progression within their communities. The implications for research and practice are correspondingly discussed.
•Extrinsic benefit plays an important role in the TVC context.•Cost factors matter in the TVC context.•Goal attainment mediates the effects of benefits and costs on satisfaction.•Opportunity cost is ...more important than actual cost.
This study investigates knowledge contributors’ satisfaction with a distinct type of virtual communities (i.e., transactional virtual communities, TVCs), where knowledge sharing is guided mainly under the principle of economic exchange, and cost–benefit tradeoff is the primary motive for knowledge sharing. Drawing upon the goal attainment theory, we examine the effects of two types of benefits (i.e., extrinsic and intrinsic) and two types of costs (i.e., actual and opportunity) on knowledge contributors’ satisfaction, and highlight the mediating role of perceived net goal attainment. A field survey with 205 subjects in a TVC in China is conducted to test the research model.
The neonatal Fc receptor (FcRn) is a key determinant of IgG homeostasis. It binds to the Fc domain of IgG in a strictly pH-dependent manner and protects IgG from lysosomal degradation. The impact of ...FcRn salvage pathway on IgG monoclonal antibody (mAb) pharmacokinetics (PK) has been well established. In this report, a set of mAbs with wild-type human Fc sequences but different Fab domains were used to examine the potential impact of Fab domain on in vitro FcRn binding and in vivo PK. We were surprised to find that mAbs with the same wild-type human Fc sequences but different Fab domains were shown to bind FcRn with considerable differences in both the binding at acidic pH and the dissociation at neutral pH, suggesting that the Fab domain may also have an impact on FcRn interaction. For these mAbs, no relationship between the FcRn binding affinity at acidic pH and in vivo PK was found. Instead, an apparent correlation between the in vitro FcRn dissociation at neutral pH and the in vivo PK in human FcRn mice, nonhuman primates and humans was observed. Our results suggested that the Fab domain of mAbs can affect their interaction with FcRn and thus their pharmacokinetic properties and that in vitro FcRn binding/dissociation assays can be a useful screening tool for pharmacokinetic assessment of mAbs with wild-type Fc sequences.
Virtual communities play an important role in business, society, and education. At present, one of the great challenges faced by virtual communities is the availability of knowledge, which is mainly ...created through knowledge-sharing behavior. Although prior studies have extensively studied knowledge-sharing behavior in virtual communities from various perspectives, they largely ignored the important role of psychological safety in this process. We propose to address this gap by examining psychological safety and its effect on individuals’ intention to continue sharing knowledge. We also identify trust in the virtual community and self-consciousness as antecedents of psychological safety. The research model is empirically tested through a survey across two virtual communities in a major university. The results show that the condition of psychological safety has a positive influence on the intention to continue sharing knowledge. The level of trust has a positive impact on the intention to continue sharing knowledge not only directly, as documented in the literature, but also indirectly, through the mediating role of psychological safety. Finally, we find that self-consciousness exerts a negative influence on feelings of psychological safety. The implications of our findings and the need for future research are also discussed.
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