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PurposeThis study aims to explore the boundary conditions of the relationship between challenge-hindrance stressors and innovative work behavior via task crafting and psychological detachment.Design/methodology/approachThe data were collected from 238 questionnaires in five technology R&D enterprises in Tianjin, China. The paper utilized structural equation modeling and cross-sectional design to test hypotheses by AMOS and examined the mediating and moderating effects using the bootstrapping method by SPSS.FindingsChallenge stressors indirectly improved innovative work behavior via task crafting, while hindrance stressors did not affect task crafting or innovative work behavior. Psychological detachment moderated the relationship between challenge stressors and innovative work behavior. When psychological detachment was high, innovative work behavior did not change regardless of challenge stressors. When psychological detachment was low, innovative work behavior increased with the increase of challenge stressors.Originality/valueThe study explains the link mechanism between stressors and innovative work behavior. It enriches the research on psychological detachment as a moderator and provides a new frame for enterprises to develop employees' innovation.

Although problem-solving skills are considered as key higher order cognitive skills, in the Chinese learning context there are gaps in the literature regarding more comprehensive examinations of which factors are likely to promote university students' creative problem-solving skills. We explored the relationships of the learning contextual factors of higher order learning and effective teaching practices with student rule-oriented, procedural, and intellectual engagement, and the students' problem-solving skills. Participants were 21,584 junior undergraduate students at 10 Chinese universities. Findings indicate that (a) effective teaching practices were the most important determinants in formulating students' problem-solving skills, (b) higher order learning was the strongest predictor of student engagement, and (c) student engagement components mediated the relationship between learning contextual factors and the development of problem-solving skills. The results of an importance–performance map analysis revealed that teachers' constructive feedback to students was a specific weakness in current Chinese teaching practices. Therefore, teachers need to provide students with more timely and facilitative feedback on their academic performance.

We formulated a conceptual model based on triadic reciprocal determinism theory, to explain the relationships among organizational innovative climate, employee work involvement, creativity, and innovative performance. We used data from 5,242 employees at science and technology-based small and medium-sized enterprises (SMEs) in Tianjin, China. Results of the structural equation modeling show that (a) employee innovative performance is a function of three determinants, namely, employee work involvement and creativity, and organizational innovative climate; (b) employee work involvement and creativity mediated between organizational innovative climate and employee innovative performance; and (c) employee creativity was the strongest predictor of innovative performance. The results of importance-performance map analysis indicate that team building was a specific weakness. Our results contribute to a better understanding of the factors affecting employee innovative performance, and the internal mechanism underlying the above relationships. Our results identify weaknesses in the enterprises' organizational climate, and we recommend how to improve performance.

L-shell X-ray fluorescence computed tomography based on polychromatic X-rays is a promising imaging technique for early cancer diagnosis. However, the presence of self-absorption and the long scanning time limit its usage in clinic. In this work, a reconstruction method based on split-Bregman algorithm which used sparseview projection data was proposed. Furthermore, the attenuation effect was also considered in the algorithm. In the attenuation correction, factors including the X-ray energy and the platinum concentration were taken into account. Then weighted factors calculated in the procedure of attenuation correction were added into the contribution function of pixels in the split-Bregman based reconstruction method. In the end, the feasibility of this method was tested using a cylindrical phantom with 8 mm in diameter by the Monte Carlo simulation. The phantom contained four inserts, all of which were 1.5 millimeter in diameter and filled with 0.10%, 0.20%, 0.40% and 0.80% platinum solutions, respectively. The results show that both the contrast-to-noise ratios and lowest detectable sensitivities are improved for the proposed method, comparing to the conventional MLEM. The contrast-to-noise ratios of images reconstructed by our method with 45 projections are already better than that reconstructed by MLEM with 60 projections. When using 60 projections in our method and comparing to 60 projections in the MLEM with correction, the contrast-to-noise ratio of the insert filled with 0.10% platinum solutions increased from 6.49 to 36.90, indicating its high efficiency and robustness.

Anti-lipopolysaccharide factors (ALFs), as main host-defense molecules of crustaceans, form a unique family of antimicrobial peptides (AMPs). MnALF4 is one isoform of ALFs isolated from the freshwater prawn Macrobrachium nipponense. In the present study, MnALF4 gene was successfully expressed in the yeast Pichia pastoris and the recombinant MnALF4 protein exhibited efficient and broad-spectrum antimicrobial activities against both Gram-positive bacteria and Gram-negative bacteria in vitro. When prawns were injected with rMnALF4 before bacterial challenge with E. coli, the recombinant protein effectively promote the elimination of bacteria by the host. It manifested that rMnALF4 could effectively kill the invading bacteria in vivo. Treatment with rMnALF4 led to remarkable changes in bacterial morphology, such as spheroidization, oversized bacteria, and cell lysis. In addition, rMnALF4 showed weak hemolysis activity to the rabbit red blood cells. Our work suggests that MnALF4 plays an important role in Macrobrachium immunity and is worthy of further investigation as a potential antibacterial agent with high efficacy against bacterial infection and low toxicity to host cells.

The stochastic momentum method is a commonly used acceleration technique for solving large-scale stochastic optimization problems in artificial neural networks. Current convergence results of stochastic momentum methods under non-convex stochastic settings mostly discuss convergence in terms of the random output and minimum output. To this end, we address the convergence of the last iterate output (called last-iterate convergence) of the stochastic momentum methods for non-convex stochastic optimization problems, in a way conformal with traditional optimization theory. We prove the last-iterate convergence of the stochastic momentum methods under a unified framework, covering both stochastic heavy ball momentum and stochastic Nesterov accelerated gradient momentum. The momentum factors can be fixed to be constant, rather than time-varying coefficients in existing analyses. Finally, the last-iterate convergence of the stochastic momentum methods is verified on the benchmark MNIST and CIFAR-10 datasets., Comment: 21pages, 4figures

Presbycusis, or age-related hearing loss (ARHL), is primarily associated with sensory or transduction nerve cell degeneration in the peripheral and/or central auditory systems. During aging, the auditory system shows mitochondrial dysfunction and increased inflammatory responses. Mitochondrial dysfunction promotes leakage of mitochondrial DNA (mtDNA) into the cytosol, which activates the cyclic GMP-AMP synthase (cGAS)-stimulator of interferon genes (STING) pathway to induce type I interferon and inflammatory responses. However, whether this pathway is involved in the occurrence and development of ARHL is unknown. This study aimed to determine whether there are age-related changes in the levels of cytosolic mtDNA and cGAS-STING pathway activation in the auditory pathway and to explore their relationship with ARHL. The results showed that cGAS-positive immunoreactive cells were observed in the cochlea, inferior colliculus, and auditory cortex. Levels of cytosolic mtDNA, cGAS, STING, phosphorylated interferon regulatory factor 3, and cytokines were significantly increased in the cochlea, inferior colliculus, and auditory cortex of 6-, 9-, and 12-month-old mice compared with 3-month-old mice. These findings suggested that cytosolic mtDNA may play an important role in the pathogenesis of ARHL by activating cGAS-STING-mediated type I interferon and inflammatory responses.

Adaptive gradient algorithm (AdaGrad) and its variants, such as RMSProp, Adam, AMSGrad, etc, have been widely used in deep learning. Although these algorithms are faster in the early phase of training, their generalization performance is often not as good as stochastic gradient descent (SGD). Hence, a trade-off method of transforming Adam to SGD after a certain iteration to gain the merits of both algorithms is theoretically and practically significant. To that end, we propose a decreasing scaling transition scheme to achieve a smooth and stable transition from Adam to SGD, which is called DSTAdam. The convergence of the proposed DSTAdam is also proved in an online convex setting. Finally, the effectiveness of the DSTAdam is verified on the CIFAR-10/100 datasets. Our implementation is available at: https://github.com/kunzeng/DSTAdam.

Clipping on learning rates in Adam leads to an effective stochastic algorithm—AdaBound. In spite of its effectiveness in practice, convergence analysis of AdaBound has not been fully explored, especially for non-convex optimization. To this end, we address the convergence of the last individual output of AdaBound for non-convex stochastic optimization problems, which is called individual convergence. We prove that, with the iteration of the AdaBound, the cost function converges to a finite value and the corresponding gradient converges to zero. The novelty of this proof is that the convergence conditions on the bound functions and momentum factors are much more relaxed than the existing results, especially when we remove the monotonicity and convergence of the bound functions, and only keep their boundedness. The momentum factors can be fixed to be constant, without the restriction of monotonically decreasing. This provides a new perspective on understanding the bound functions and momentum factors of AdaBound. At last, numerical experiments are provided to corroborate our theory and show that the convergence of AdaBound extends to more general bound functions.

It is vital to quickly and effectively determine the extent and depth of geological body by using potential field data in gravity and magnetic survey. In this study, three key techniques studying the extent and depth of geological sources based on curvature attribute are studied: the optimal solutions to the objective function, the edge of geological bodies and picking out solutions. Firstly, the optimal solution to the objective function is studied, that is, the key extraction algorithm about the curvature attribute. The Huber norm is introduced into the extraction algorithm of curvature attribute, which more accurately detect the depth of edge of the geological bodies. Secondly, the normalized vertical derivative of the total horizontal derivative (NVDR-THDR) technique is introduced into curvature attribute, which shows more continuous results about the edge position of the geological bodies and more sensitive to the small-scale tectonic structure. Finally, we study the way to pick out the inversion solution, that is, to solve the multi-solution equations in the inversion. The upward continuation of a certain height with strict physical significance was introduced into the inversion method, which was used to suppress the noise, and the final and actual inversion depth was equal to the inversion depth minus the height of upward continuation. And the average value of threshold limitation technology of the potential fields data was also introduced into this method. Using the two technologies, solutions of non-field source edge positions were eliminated, and make the inversion solutions closer to the actual situation. Through the above three key techniques, the accuracy, continuity and recognition to the small-scale structure of the inversion result are optimized. The theoretical models are used to verify the effectiveness of the above key technologies, the results show that the three key technologies have achieved good results, and the combined models are used to verify the effectiveness of the optimized inversion method. The measured aeromagnetic data were used to inversing the edge depth of the intrusive rock in a mining area, and the inversion results are in good agreement with the rock depth revealed by borehole.

Bacillus subtilis is widely used for large-scale industrial production of heterologous proteins. Because of its high intrinsic secretory capacity, it can efficiently secrete proteins into the culture supernatant via the general Sec-type secretion pathway. In this study, the α-amylase AmyS was used as a reporter to construct a library encompassing 173 Sec-type signal peptides (SPs) from B. subtilis using a fast, sequence-independent method. The resulting library DNA which harbored different signal peptides in the expression vector was used to transform B. subtilis directly at high efficiency, and 15 SPs which produced a significantly increased yield of AmyS were identified using a starch-iodine-based high-throughput assay. Furthermore, the correlation between the sequences of the best-performing signal peptides and their secretion efficiency was analyzed, which revealed several common properties of these SPs. Finally, high-cell-density fermentation of the α-amylase-producing strain with the best-performing signal peptide yielded a maximum of 5086 U/mL amylase at 66 h with a high productivity of 77.1 U/mL·h.

China’s higher education system has been marked by dramatic growth since 1999. In response to calls for quality assurance, substantial efforts have been made to improve collegiate environments and enhance student learning. However, only limited empirical research has been conducted to investigate the effects of the college environment on student gains in the Chinese context. Drawing on data from 1121 students at a prestigious four-year university, this study investigated how college environmental factors (i.e., course challenge, faculty guidance, academic climate, and interpersonal relationships) and student involvement affected students’ intellectual development. The results of the structural equation modeling indicated that academic involvement mediated the relations between college environmental factors and intellectual development. Among the four environmental factors studied, faculty guidance was the strongest predictor of intellectual development. The results highlight the pivotal role of teachers in student involvement and development. Practical implications for the design of college environments conducive to student learning are discussed.