200 research outputs found

    Do Farmers Adopt Fewer Conservation Practices on Rented Land? Evidence from Straw Retention in China

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    We examine how land tenure arrangements affect Chinese crop farmers’ adoption of straw retention, a key conservation practice promoted by the Chinese government in part to curb rising air pollution. Using data from a 2016 farmer household survey covering 1,659 crop plots in Henan Province in central China, we analyze whether farmers are less likely to adopt straw retention on rented plots compared to own-contracted plots. To address the potential endogeneity of the choice of renting from others, we use an instrument exploiting the role of remittance income from household members migrated to cities in a bivariate probit model and a control function approach, respectively. Our main results reveal that the Chinese crop farmers’ likelihood of adopting straw retention were almost cut in half on rented plots compared to their owned plots, assuming the assumptions for biprobit or control functions hold. This suggests greater attention is needed to examine the spillovers across agricultural and environmental policies as China pushes for both a nationwide land rental market and more sustainable agricultural practices

    Land Tenure and Adoption of Straw Retention: Evidence from Henan, China

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    We examine how land tenure arrangements affect Chinese crop farmers’ adoption of straw retention, a key conservation practice promoted by the Chinese government in part to curb rising air pollution. Using data from a 2016 farmer household survey covering 1,659 crop plots in Henan Province in central China, we analyze how straw retention choices are influenced by two different land tenure arrangements: own-contracted plots versus rented plots. Empirical results from several probit regressions reveal that, after controlling for crop choice, harvest season, spatial climate, and other plot-level and household-level covariates, a rented plot is associated with a 10.7 percent reduction in the probability of adopting straw retention after harvest throughout 2015. A Heckman selection model that corrects the sample selection bias further supports the negative correlation between less secure rented farmland and straw retention adoption. This suggests that more caution and attention is warranted to the long-term sustainability of farmland in urbanizing China as the Chinese government keeps pushing for further development of rural land rental market

    Selective gas detection using Mn3O4/WO3 composites as a sensing layer

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    Pure WO3 sensors and Mn3O4/WO3 composite sensors with different Mn concentrations (1 atom %, 3 atom % and 5 atom %) were successfully prepared through a facile hydrothermal method. As gas sensing materials, their sensing performance at different temperatures was systematically investigated for gas detection. The devices displayed different sensing responses toward different gases at specific temperatures. The gas sensing performance of Mn3O4/WO3 composites (especially at 3 atom % Mn) were far improved compared to sensors based on pure WO3, where the improvement is related to the heterojunction formed between the two metal oxides. The sensor based on the Mn3O4/WO3 composite with 3 atom % Mn showed a high selective response to hydrogen sulfide (H2S), ammonia (NH3) and carbon monoxide (CO) at working temperatures of 90 degrees C, 150 degrees C and 210 degrees C, respectively. The demonstrated superior selectivity opens the door for potential applications in gas recognition and detection

    A framework for learning analytics using commodity wearable devices

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    We advocate for and introduce LEARNSense, a framework for learning analytics using commodity wearable devices to capture learner’s physical actions and accordingly infer learner context (e.g., student activities and engagement status in class). Our work is motivated by the observations that: (a) the fine-grained individual-specific learner actions are crucial to understand learners and their context information; (b) sensor data available on the latest wearable devices (e.g., wrist-worn and eye wear devices) can effectively recognize learner actions and help to infer learner context information; (c) the commodity wearable devices that are widely available on the market can provide a hassle-free and non-intrusive solution. Following the above observations and under the proposed framework, we design and implement a sensor-based learner context collector running on the wearable devices. The latest data mining and sensor data processing techniques are employed to detect different types of learner actions and context information. Furthermore, we detail all of the above efforts by offering a novel and exemplary use case: it successfully provides the accurate detection of student actions and infers the student engagement states in class. The specifically designed learner context collector has been implemented on the commodity wrist-worn device. Based on the collected and inferred learner information, the novel intervention and incentivizing feedback are introduced into the system service. Finally, a comprehensive evaluation with the real-world experiments, surveys and interviews demonstrates the effectiveness and impact of the proposed framework and this use case. The F1 score for the student action classification tasks achieve 0.9, and the system can effectively differentiate the defined three learner states. Finally, the survey results show that the learners are satisfied with the use of our system (mean score of 3.7 with a standard deviation of 0.55)

    Induction of the HIV-1 Tat co-factor cyclin T1 during monocyte differentiation is required for the regulated expression of a large portion of cellular mRNAs

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    BACKGROUND: P-TEFb, a general RNA polymerase II elongation factor, is composed of CDK9 (cyclin-dependent kinase 9) as a catalytic unit and either cyclin T1, T2 or K as a regulatory subunit. The cyclin T1/P-TEFb complex is targeted by HIV to mediate Tat transactivation. Cyclin T1 protein expression is induced during early macrophage differentiation, suggesting a role in regulation of mRNA expression during the differentiation process. To study the functional significance of cyclin T1 induction during differentiation, we utilized the human Mono Mac 6 (MM6) monocytic cell line. RESULTS: We found that cyclin T1 protein expression is induced by a post-transcriptional mechanism following PMA treatment of MM6 cells, similar to its induction in primary monocytes and macrophages. Also in agreement with findings in primary cells, cyclin T2a is present at relatively high levels in MM6 cells and is not induced by PMA. Although the knock-down of cyclin T1 in MM6 cells by shRNA inhibited HIV-1 Tat transactivation, MM6 cell growth was not affected by the depletion of cyclin T1. Using DNA microarray technology, we found that more than 20% of genes induced by PMA require cyclin T1 for their normal level of induction, and approximately 15% of genes repressed by PMA require cyclin T1 for their normal level of repression. Gene ontology analysis indicates that many of these cyclin T1-dependent genes are related to immune response and signal transduction. CONCLUSION: These results suggest that cyclin T1 serves a critical role in the program of macrophage differentiation, and this raises questions about the feasibility of cyclin T1 serving as an antiviral therapeutic target
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