1,135 research outputs found
ESTIMATING EFFECTS OF AGRICULTURAL RESEARCH AND EXTENSION EXPENDITURES ON PRODUCTIVITY: A TRANSLOG PRODUCTION FUNCTION APPROACH
The effects of agricultural research and extension expenditures on productivity in the United States are estimated during the period 1949-81 using data for ten production regions. The large time-series cross-sectional data base allows the translog production function to be estimated directly. Results from the translog and Cobb-Douglas production functions are compared. The results indicate that use of the Cobb-Douglas production function would overestimate the internal rate of return of agricultural research and extension expenditures in the United States and eight production regions. The total marginal product and internal rate of return for the United States are $8.11 and 66 percent, respectively.Productivity Analysis,
Template-Instance Loss for Offline Handwritten Chinese Character Recognition
The long-standing challenges for offline handwritten Chinese character
recognition (HCCR) are twofold: Chinese characters can be very diverse and
complicated while similarly looking, and cursive handwriting (due to increased
writing speed and infrequent pen lifting) makes strokes and even characters
connected together in a flowing manner. In this paper, we propose the template
and instance loss functions for the relevant machine learning tasks in offline
handwritten Chinese character recognition. First, the character template is
designed to deal with the intrinsic similarities among Chinese characters.
Second, the instance loss can reduce category variance according to
classification difficulty, giving a large penalty to the outlier instance of
handwritten Chinese character. Trained with the new loss functions using our
deep network architecture HCCR14Layer model consisting of simple layers, our
extensive experiments show that it yields state-of-the-art performance and
beyond for offline HCCR.Comment: Accepted by ICDAR 201
Event Detection from Social Media Stream: Methods, Datasets and Opportunities
Social media streams contain large and diverse amount of information, ranging
from daily-life stories to the latest global and local events and news.
Twitter, especially, allows a fast spread of events happening real time, and
enables individuals and organizations to stay informed of the events happening
now. Event detection from social media data poses different challenges from
traditional text and is a research area that has attracted much attention in
recent years. In this paper, we survey a wide range of event detection methods
for Twitter data stream, helping readers understand the recent development in
this area. We present the datasets available to the public. Furthermore, a few
research opportunitiesComment: 8 page
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Paxillin facilitates timely neurite initiation on soft-substrate environments by interacting with the endocytic machinery.
Neurite initiation is the first step in neuronal development and occurs spontaneously in soft tissue environments. Although the mechanisms regulating the morphology of migratory cells on rigid substrates in cell culture are widely known, how soft environments modulate neurite initiation remains elusive. Using hydrogel cultures, pharmacologic inhibition, and genetic approaches, we reveal that paxillin-linked endocytosis and adhesion are components of a bistable switch controlling neurite initiation in a substrate modulus-dependent manner. On soft substrates, most paxillin binds to endocytic factors and facilitates vesicle invagination, elevating neuritogenic Rac1 activity and expression of genes encoding the endocytic machinery. By contrast, on rigid substrates, cells develop extensive adhesions, increase RhoA activity and sequester paxillin from the endocytic machinery, thereby delaying neurite initiation. Our results highlight paxillin as a core molecule in substrate modulus-controlled morphogenesis and define a mechanism whereby neuronal cells respond to environments exhibiting varying mechanical properties
Template-Based Structure Prediction and Classification of Transcription Factors in \u3ci\u3eArabidopsis thaliana\u3c/i\u3e
Transcription factors (TFs) play important roles in plants. However, there is no systematic study of their structures and functions of most TFs in plants. Here, we performed template-based structure prediction for all TFs in Arabidopsis thaliana, with their full-length sequences as well as C-terminal and N-terminal regions. A total of 2,918 model structures were obtained with a high confidence score. We find that TF families employ only a smaller number of templates for DNA-binding domains (DBD) but a diverse number of templates for transcription regulatory domains (TRD). Although TF families are classified according to DBD, their sizes have a significant correlation with the number of unique non-DNA-binding templates employed in the family (Pearson correlation coefficient of 0.74). That is, the size of TF family is related to its functional diversity. Network analysis reveals new connections between TF families based on shared TRD or DBD templates; 81% TF families share DBD and 67% share TRD templates. Two large fully connected family clusters in this network are observed along with 69 island families. In addition, 25 genes with unknown functions are found to be DNA-binding and/or TF factors according to predicted structures. This work provides a global view of the classification of TFs based on their DBD or TRD templates, and hence, a deeper understanding of DNA-binding and regulatory functions from structural perspective. All structural models of TFs are deposited in the online database for public usage at http://sysbio.unl.edu/AthTF
Template-Based Structure Prediction and Classification of Transcription Factors in \u3ci\u3eArabidopsis thaliana\u3c/i\u3e
Transcription factors (TFs) play important roles in plants. However, there is no systematic study of their structures and functions of most TFs in plants. Here, we performed template-based structure prediction for all TFs in Arabidopsis thaliana, with their full-length sequences as well as C-terminal and N-terminal regions. A total of 2,918 model structures were obtained with a high confidence score. We find that TF families employ only a smaller number of templates for DNA-binding domains (DBD) but a diverse number of templates for transcription regulatory domains (TRD). Although TF families are classified according to DBD, their sizes have a significant correlation with the number of unique non-DNA-binding templates employed in the family (Pearson correlation coefficient of 0.74). That is, the size of TF family is related to its functional diversity. Network analysis reveals new connections between TF families based on shared TRD or DBD templates; 81% TF families share DBD and 67% share TRD templates. Two large fully connected family clusters in this network are observed along with 69 island families. In addition, 25 genes with unknown functions are found to be DNA-binding and/or TF factors according to predicted structures. This work provides a global view of the classification of TFs based on their DBD or TRD templates, and hence, a deeper understanding of DNA-binding and regulatory functions from structural perspective. All structural models of TFs are deposited in the online database for public usage at http://sysbio.unl.edu/AthTF
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