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In the passing decade, we have witnessed the exponential growth of social media use globally. Along with the increasing popularity of social media are the stories of addictive use, especially among younger generations. Previous studies have found that addictive social media use is associated with negative consequences such as reduced productivity and attention span, task avoidance and procrastination, information overload, and emotional collapse. However, a holistic conceptual understanding of the phenomenon is lacking to support future research investigations and to better inform the design of educational and intervention programs. Therefore, in this study, I explored people’s experiences of social media addiction and the process of how social media addiction develops, with a purpose to generate a substantive theory specific to this phenomenon. I followed the grounded theory approach from Strauss and Corbin (2015) and collected rich qualitative data through interviews, diaries, surveys, and social media activities from 20 college students. The final theoretical framework and its main categories were developed following an iterative process (e.g., constant comparison and theoretical sampling) and evaluated using multiple strategies. The generated theory outlines a dynamic process between two major categories involved in the development of social media addiction: gratification-seeking and self-control. I use the “tug of war” metaphor as the core category to portray this fluctuating and struggling process. I argue that the development of social media addiction involves a constant tussle between gratification-seeking and self-control and that addictive use happens when self-control loses the “tug of war” to reinforced gratification-seeking. Variations and sub-processes were identified and constructed under the categories of gratification-seeking and self-control. In addition to this core process, I also captured four groups of situational triggers (temporal, relational, emotional, and physical) prompting social media use and various contextual factors (in categories of individual differences, socio-cultural influences, and technological influences) contributing to excessive gratification-seeking on social media. The results of this study can support future research with a conceptual framework specific to social media addiction. They also can help identify existing research gaps and potential future research directions, inform the design of educational and intervention programs for social media addiction, and offer guidance for social practices and policymaking.

The water dropworts Oenanthe linearis Wall. ex DC. and O. javanica (Blume) DC. are aquatic perennial herbs that have been used in China as vegetables and traditional medicines. However, their phylogenetic relationships and genetic diversity are poorly understood. Here, we presented the phenotypic traits and genome-wide DNA marker-based analysis of 158 water dropwort accessions representing both species. The analysis revealed that Oenanthe linearis was readily segregated into linear-leaf and deep-cleft leaf water dropworts according to their leaf shapes at flowering. Oenanthe javanica was classified by clustering analysis into two clusters based mainly on the morphological characteristics of their ultimate segments (leaflets). A set of 11 493 high-quality single-nucleotide polymorphisms was identified and used to construct a phylogenetic tree. There was strong discrimination between O. linearis and O. javanica, which was consistent with their phenotype diversification. The population structure and phylogenetic tree analyses suggested that the O. linearis accessions formed two major groups, corresponding to the linear-leaf and deep-cleft leaf types. The most obvious phenotypic differences between them were fully expressed at the reproductive growth stage. A single-nucleotide polymorphism-based analysis revealed that the O. javanica accessions could be categorized into groups I andII. However, this finding did not entirely align with the clusters revealed by morphological classification. Landraces were clustered into one group along with the remaining wild accessions. Hence, water dropwort domestication was short in duration. The level of genetic diversity for O. linearis (π = 0.1902) was slightly lower than that which was estimated for O. javanica (π = 0.2174). There was a low level of genetic differentiation between O. linearis and O. javanica (Fst = 0.0471). The mean genetic diversity among accessions ranged from 0.1818 for the linear-leaf types to 0.2318 for the groupII accessions. The phenotypic traits and the single-nucleotide polymorphism markers identified here lay empirical foundation for future genomic studies on water dropwort.

Due to the multiple gear-pair meshes in planetary gear train, fault features of tooth root crack are weak and complicated in vibration signals. Influenced by the time-varying transfer paths of vibration signals, the fault features of crack are further weakened, which becomes hard to diagnose. To reveal the origination of crack fault features, a lumped-parameter-model of planetary gear train is firstly built to solve the excitation forces that generate vibration signals. Gear mesh stiffness that drives the excitation forces is used to equivalently reflect the crack characteristics. Secondly, a finite-element-model of flexible housing is used to calculate the time-varying transfer functions that determine the amplitude characteristics of vibration signals. Based on the signal convolution theorem, the full-band vibration signal is deduced by the convolution of excitation forces and flexible transfer functions. Simulations and experimental tests on two typical types of planetary gear trains show good consistency at crack fault frequency features, which effectively validates the proposed models. Significant fault features locating at resonance modulation sidebands are summarized as effective indicators for crack diagnosis.

Taro (Colocasia esculenta) is an important root and tuber crop cultivated worldwide. There are two main types of taro that vary in morphology of corm and cormel, ‘dasheen’ and ‘eddoe’. The eddoe type (Colocasia esculenta var. antiquorium) is predominantly distributed throughout China. Characterizing the genetic diversity present in the germplasm bank of taro is fundamental to better manage, conserve and utilize the genetic resources of this species. In this study, the genetic diversity of 234 taro accessions from 16 provinces of China was assessed using 132,869 single nucleotide polymorphism (SNP) markers identified by specific length amplified fragment-sequencing (SLAF-seq). Population structure and principal component analysis permitted the accessions to be categorized into eight groups. The genetic diversity and population differentiation of the eight groups were evaluated using the characterized SNPs. Analysis of molecular variance showed that the variation among eight inferred groups was higher than that within groups, while a relatively small variance was found among the two morphological types and 16 collection regions. Further, a core germplasm set comprising 41 taro accessions that maintained the genetic diversity of the entire collection was developed based on the genotype. This research is expected to be valuable for genetic characterization, germplasm conservation, and breeding of taro.

Cryptococcosis is a potential fatal disease, especially in immunocompromised patients. In China, the profile of cryptococcosis is unclear. Therefore, we summarize the epidemiology and therapy of cryptococcosis in china.All cases reports about cryptococcosis in China were collected from CBMdisk database (China Biology and Medicine data disc) with key words of cryptococcosis, or cryptococcal infection, or cryptococcus, and case. The features of the cryptococcosis were retrospectively analyzed.There were 1,032 reports about cryptococcosis, including 8,769 cases. Among them, there were 16% patient with AIDS/HIV, and 17% ones without underlying diseases. There were 2,371 cases of CNS infection. Among them of 2,068 cases, the treatment protocols and outcome were clearly described. The percentages of patients who received intrathecal treatment of amphotericin B(AmB), AmB + 5-FC(5-fluorocytosine), AmB + FCZ(fluconazole), and AmB + 5-FU + FCZ in each medication group were 10, 43, 53, and 33%, respectively. The mortalities were significantly lower in the AmB, Amb + 5-FC, AmB + FCZ intrathecal treatment groups compared with their non-intrathecal treatment controls (6% vs. 23%, 25% vs. 35%, 20% vs. 30%, respectively, P0.05), but not in the intrathecal AmB + 5-FU + FCZ group (35% vs. 26%, P0.05).The Chinese cryptococcosis had its own special clinical features, such as more patients without identifiable underlying diseases. Intrathecal injection of amphotericin B was effective treatment method for cryptococcal CNS infection in China.