Productivity effect and overuse of pesticide in crop production in China ZHANG Chao, Guanming Shi , SHEN Jian, HU Rui-fa (1State Key Laboratory of Crop Genetics Germplasm Enhancement, Hybrid Cotton RD Engineering Research Center, Ministry of Education/College of Agriculture, Nanjing Agricultural University, Nanjing 210095, P.R.China 2College of Life Sciences, Nanjing Agricultural University, Nanjing 210095, P.R.China)
Journal of Integrative Agriculture,
09/2015, Letnik:
14, Številka:
9
Journal Article
Recenzirano
Odprti dostop
Chinese farmers are often accused of overusing pesticides that play a crucial role in enhancing crop yield by reducing losses to crop pests. Pesticide overuse has caused a series of negative health ...and environmental externalities. This paper quantifies the productivity effect and the optimal amount of pesticides in rice, cotton and maize production in China from the economic perspective. Using survey data collected in 2012 and 2013, both Cobb-Douglas and Weibull damage control specifications are used to estimate the production function. Results show that pesticides have statistically significant pro- ductivity effect on crop yield. On the condition of Weibull damage control specifications, the marginal products of 1 kg of the active ingredients of pesticides for rice, cotton and maize are 71.06, 22.73 and 98.45 kg, respectively. However, 57, 64 and 17% of the actual amount of pesticides are overused for rice, cotton and maize, respectively. Moreover, the productivity effect of pesticides would be overestimated using Cobb-Douglas specification without incorporating a damage control agent.
In this paper, we propose a reduced-rank space-time adaptive processing (STAP) technique for airborne phased array radar applications. The proposed STAP method performs dimensionality reduction by ...using a reduced-rank switched joint interpolation, decimation and filtering algorithm (RR-SJIDF). In this scheme, a multiple-processing-branch (MPB) framework, which contains a set of jointly optimized interpolation, decimation and filtering units, is proposed to adaptively process the observations and suppress jammers and clutter. The output is switched to the branch with the best performance according to the minimum variance criterion. In order to design the decimation unit, we present an optimal decimation scheme and a low-complexity decimation scheme. We also develop two adaptive implementations for the proposed scheme, one based on a recursive least squares (RLS) algorithm and the other on a constrained conjugate gradient (CCG) algorithm. The proposed adaptive algorithms are tested with simulated radar data. The simulation results show that the proposed RR-SJIDF STAP schemes with both the RLS and the CCG algorithms converge at a very fast speed and provide a considerable SINR improvement over the state-of-the-art reduced-rank schemes.
Machine learning methods for protein function prediction are urgently needed, especially now that a substantial fraction of known sequences remains unannotated despite the extensive use of functional ...assignments based on sequence similarity. One major bottleneck supervised learning faces in protein function prediction is the structured, multi-label nature of the problem, because biological roles are represented by lists of terms from hierarchically organised controlled vocabularies such as the Gene Ontology. In this work, we build on recent developments in the area of deep learning and investigate the usefulness of multi-task deep neural networks (MTDNN), which consist of upstream shared layers upon which are stacked in parallel as many independent modules (additional hidden layers with their own output units) as the number of output GO terms (the tasks). MTDNN learns individual tasks partially using shared representations and partially from task-specific characteristics. When no close homologues with experimentally validated functions can be identified, MTDNN gives more accurate predictions than baseline methods based on annotation frequencies in public databases or homology transfers. More importantly, the results show that MTDNN binary classification accuracy is higher than alternative machine learning-based methods that do not exploit commonalities and differences among prediction tasks. Interestingly, compared with a single-task predictor, the performance improvement is not linearly correlated with the number of tasks in MTDNN, but medium size models provide more improvement in our case. One of advantages of MTDNN is that given a set of features, there is no requirement for MTDNN to have a bootstrap feature selection procedure as what traditional machine learning algorithms do. Overall, the results indicate that the proposed MTDNN algorithm improves the performance of protein function prediction. On the other hand, there is still large room for deep learning techniques to further enhance prediction ability.
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Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Chloramphenicol was chosen as the imprinting molecule and the methacrylic acid was chosen as the functional monomer to prepare molecularly imprinted polymers. Ethylene glycol dimethacrylate, ...pentaerythritol triacrylate, and trimethylolpropane trimethylacrylate were used as the cross‐linking agents, respectively. The interaction processes between chloramphenicol and methacrylic acid were simulated by using the ωB97XD/6‐31G (d,p) method. The self‐assembled configuration, bonding sites, binding number, binding energy, and interaction principle of stable complex formed by chloramphenicol and methacrylic acid with different molar ratios have been studied. The selectivity of the most stable complex formed from chloramphenicol and methacrylic acid was discussed with the thiamphenicol and florfenicol as the analogues of chloramphenicol. The results showed that chloramphenicol and methacrylic acid were interacted through the hydrogen bonds. When the molar ratio was 1:10 and pentaerythritol triacrylate as the cross‐linking agent, the ordered complex formed by chloramphenicol and methacrylic acid has the largest amount of hydrogen bonds and the lowest binding energy. Scatchard analysis showed that the maximum apparent adsorption capacity was 173.3 mg/g (0.536 mol/g), and the selection factor of florfenicol was the largest. This study provides a reliable theoretical and experimental basis for the design, preparation, and characterization of chloramphenicol molecularly imprinted polymers.
In this paper, a low-complexity multiple feedback successive interference cancellation (MF-SIC) strategy is proposed for the uplink of multiuser multiple-input multiple-output (MU-MIMO) systems. In ...the proposed MF-SIC algorithm with shadow area constraints (SAC), an enhanced interference cancellation is achieved by introducing {constellation points as the candidates} to combat the error propagation in decision feedback loops. We also combine the MF-SIC with multi-branch (MB) processing, which achieves a higher detection diversity order. For coded systems, a low-complexity soft-input soft-output (SISO) iterative (turbo) detector is proposed based on the MF and the MB-MF interference suppression techniques. The computational complexity of the MF-SIC is comparable to the conventional SIC algorithm since very little additional complexity is required. Simulation results show that the algorithms significantly outperform the conventional SIC scheme and approach the optimal detector.
Long-wave sensitive (LWS) is a G protein-coupled receptor expressed in the retina, and zebrafish is a better model organism for studying vision, but the role of LWS1 in vision-guided behavior of ...larvae fish has rarely been reported. In this study, we found that zebrafish
lws1
and
lws2
are tandemly replicated genes, both with six exons, with
lws1
being more evolutionarily conserved. The presence of Y277F in the amino acid sequence of
lws2
may have contributed to the shift of λ
max
to green light. We established a
lws1
knockout zebrafish model using CRISPR/Cas9 technology.
Lws1
−/−
larvae showed significantly higher levels of feeding and appetite gene (
agrp
) expression than WT, and significantly lower levels of anorexia gene (
pomc
,
cart
) expression. In addition, green light gene compensation was observed in
lws1
−/−
larvae with significantly increased expression levels of
rh2-1
. The light-dark movement test showed that
lws1
−/−
larvae were more active under light-dark transitions or vibrational stimuli, and the expression of phototransduction-related genes was significantly up-regulated. This study reveals the important role of
lws1
gene in the regulation of vision-guided behavior in larvae.
We develop a reduced-rank space-time adaptive processing (STAP) method based on joint iterative optimization of filters (JOINT) for airborne radar applications. The proposed method consists of a bank ...of full-rank adaptive filters, which forms the projection matrix, and an adaptive reduced-rank filter that operates at the output of the bank of filters. We describe the proposed method for both the direct-form processor (DFP) and the generalized sidelobe canceller (GSC) structures. Adaptive algorithms including the stochastic gradient (SG), the recursive least square (RLS), and their hybrid algorithms are derived for the efficient implementation of the JOINT STAP method. The computational complexity analysis of the proposed algorithms is shown in terms of the number of multiplications and additions per snapshot. Furthermore, the convexity analysis of the proposed method is carried out. Simulations for a clutter-plus-jamming suppression application show that the proposed STAP algorithm outperforms the state-of-the-art reduced-rank schemes in convergence and tracking at significantly lower complexity.
To determine whether intravesical bacillus Calmette-Guérin (BCG) administration reduces recurrence after transurethral resection of superficial bladder cancer using a meta-analysis.
Published data of ...randomized clinical trials comparing transurethral resection plus intravesical BCG to either resection alone or resection plus another treatment were analyzed, considering possible confounding factors such as disease type, maintenance therapy, and others. Both the fixed effect model and the randomized effect model were applied, and the odds ratio (OR) with its 95% confidence interval (CI) was used as the effect size estimate.
We searched 176 trials, eliminated 151 of them, and identified 25 trials with recurrence information on 4767 patients. Of 2342 patients undergoing BCG therapy, 949 (40.5%) had tumor recurrence compared with 1205 (49.7%) of 2425 patients in the non-BCG group. In the combined results, a statistically significant difference in the OR for tumor recurrence between the BCG and no BCG-treated groups was found (randomized combined effect OR 0.61, 95% CI 0.46 to 0.80,
P <0.0001). Stratified by BCG maintenance and disease type, the combined results of the individual reports showed statistical significance for BCG maintenance (OR 0.47, 95% CI 0.28 to 0.78,
P = 0.004) and treatment of papillary carcinoma (OR 0.50, 95% CI 0.33 to 0.75,
P = 0.0008). Chemotherapy and BCG plus chemotherapy/immunotherapy were not better than BCG alone.
Adjuvant intravesical BCG with maintenance treatment is effective for the prophylaxis of tumor recurrence in superficial bladder cancer. For patients with papillary carcinoma, adjuvant intravesical BCG with maintenance therapy should be offered as the treatment of choice.
The introduction and use of foreign germplasms have played an important role in the improvement of crop varieties in China. Based on published materials and scientist interviews, we collected data on ...the sown area, morphological characteristics, and pedigree of the popular rice varieties grown in the 15 major rice production provinces and 1 autonomous region in China, from 1982 to 2011. Results showed that China＇s scientists developed the largest number of rice varieties worldwide, and that rice yield potential and grain quality have substantiality improved during the studied period. In contrast, resistance of newly-released varieties to diseases and insect pests has decreased since the 1990s. Germplasms from the Interna- tional Rice Research Institute （IRRI） and from Japan have contributed 16.4 and 11.2% of genetic materials to China＇s rice varieties developed between 1982 and 2011, respectively. While IRRI＇s materials contributed to the improvement of yield potential, growth duration, and blast and bacterial blight resistance, Japanese materials contributed to the improvement of grain quality. Materials from other countries contributed to the improvement of resistance to diseases and insect pests, particularly to rice blast disease, brown planthoppers, white-backed planthoppers, and striped stem borers.
A bis-Schiff base N,N'-ethylene-bis(3-bromosalicylaldimine) (H2L) was prepared from 3-bromosalicylaldehyde and ethane-1,2-diamine. With H2L as ligand, a new copper(II) complex CuL (1) and a new ...cobalt(III) complex CoL(NCS)(DMF) (2) were prepared and characterized by physico-chemical methods and single crystal X-ray analysis. X-ray analysis indicates that the Cu atom in complex 1 is in square planar coordination, and the Co atom in complex 2 is in octahedral coordination. The compounds were tested in vitro for their antibacterial activities on Bacillus subtilis, Staphylococcus aureus, Escherichia coli and Pseudomonas fluorescens. Both complexes have effective activities on the bacteria.
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