5,186 research outputs found
Nitrogen fertilisation management in precision agriculture: a preliminary application example on maize
The adoption of precision agriculture techniques for N management has the potential for improving agronomic, economic and environmental efficiency in the use of such input. The present work was aimed at testing a simplified N balance method for the prescription of N fertilisation in uniform management zones defined from information on measured soil properties on grain maize in central Italy. The results of this preliminary experience show that the application of the N balance prescription map did not bring to significant differences, from a uniform N fertilisation, in terms of grain yield, economic return above N cost and nitrate content in the soil profile at the end of the growing season. However, the adoption of the prescribed N fertilisation strategy for the whole field would have caused a limited saving in the amount of fertiliser employed, quantified at about 10 kg N haâ1
Rethinking the competition between detection and ReID in Multi-Object Tracking
Due to balanced accuracy and speed, joint learning detection and ReID-based
one-shot models have drawn great attention in multi-object tracking(MOT).
However, the differences between the above two tasks in the one-shot tracking
paradigm are unconsciously overlooked, leading to inferior performance than the
two-stage methods. In this paper, we dissect the reasoning process of the
aforementioned two tasks. Our analysis reveals that the competition of them
inevitably hurts the learning of task-dependent representations, which further
impedes the tracking performance. To remedy this issue, we propose a novel
cross-correlation network that can effectively impel the separate branches to
learn task-dependent representations. Furthermore, we introduce a scale-aware
attention network that learns discriminative embeddings to improve the ReID
capability. We integrate the delicately designed networks into a one-shot
online MOT system, dubbed CSTrack. Without bells and whistles, our model
achieves new state-of-the-art performances on MOT16 and MOT17. Our code is
released at https://github.com/JudasDie/SOTS
Detection of anatid herpesvirus 1 gC gene by TaqMan⢠fluorescent quantitative real-time PCR with specific primers and probe
<p>Abstract</p> <p>Background</p> <p>Anatid herpesvirus 1 (AHV-1) is known for the difficulty of monitoring and controlling, because it has a long period of asymptomatic carrier state in waterfowls. Furthermore, as a significant essential agent for viral attachment, release, stability and virulence, <it>gC </it>(<it>UL44</it>) gene and its protein product (glycoprotein C) may play a key role in the epidemiological screening. The objectives of this study were to rapidly, sensitively, quantitatively detect <it>gC </it>gene of AHV-1 and provide the underlying basis for further investigating pcDNA3.1-gC DNA vaccine in infected ducks by TaqMan⢠fluorescent quantitative real-time PCR assay (FQ-PCR) with pcDNA3.1-gC plasmid.</p> <p>Results</p> <p>The repeatable and reproducible quantitative assay was established by the standard curve with a wide dynamic range (eight logarithmic units of concentration) and very good correlation values (1.000). This protocol was able to detect as little as 1.0 à 10<sup>1 </sup>DNA copies per reaction and it was highly specific to AHV-1. The TaqMan⢠FQ-PCR assay successfully detected the <it>gC </it>gene in tissue samples from pcDNA3.1-gC and AHV-1 attenuated vaccine (AHV-1 Cha) strain inoculated ducks respectively.</p> <p>Conclusions</p> <p>The assay offers an attractive method for the detection of AHV-1, the investigation of distribution pattern of AHV-1 in vivo and molecular epidemiological screening. Meanwhile, this method could expedite related AHV-1 and gC DNA vaccine research.</p
Ground beetle assemblages in Beijingâs new mountain forests
Mature forests have been almost completely destroyed in Chinaâs northern regions, but this has been followed by large-scale reforestation in the wake of environmental degradation. Although future forest plantations are expected to expand over millions of hectares, knowledge about the ecology and biodiversity of Chinaâs replanted forests remains very limited. Addressing these knowledge gaps, we recorded ground beetle (Coleoptera: Carabidae) communities in five secondary forest types: plantations of Chinese Pine (Pinus tabulaeformis) and Prince Rupprechtâs Larch (Larix principis-rupprechtii), Oak (Quercus wutaishanica) and Asian White Birch (Betula platyphylla) woodlands, and naturally regenerated mixed forest. Species richness peaked in mixed forests, while pine and oak woodlands harboured discrete communities of intermediate species richness. Oak, pine and mixed forest habitats also showed high levels of species turnover between plots. Canopy closure was an important factor influencing ground beetle assemblages and diversity, and a number of forest specialist species only occurred in pine or oak forests. We believe that some forest specialists have survived earlier deforestation and appear to be supported by new plantation forests, but maintenance of secondary native oak and mixed forests is crucial to safeguard the overall species pool
The LAMOST Complete Spectroscopic Survey of Pointing Area (LaCoSSPAr) in the Southern Galactic Cap I. The Spectroscopic Redshift Catalog
We present a spectroscopic redshift catalog from the LAMOST Complete
Spectroscopic Survey of Pointing Area (LaCoSSPAr) in the Southern Galactic Cap
(SGC), which is designed to observe all sources (Galactic and extra-galactic)
by using repeating observations with a limiting magnitude of in
two fields. The project is mainly focusing on the completeness of
LAMOST ExtraGAlactic Surveys (LEGAS) in the SGC, the deficiencies of source
selection methods and the basic performance parameters of LAMOST telescope. In
both fields, more than 95% of galaxies have been observed. A post-processing
has been applied to LAMOST 1D spectrum to remove the majority of remaining sky
background residuals. More than 10,000 spectra have been visually inspected to
measure the redshift by using combinations of different emission/absorption
features with uncertainty of . In total, there are 1528
redshifts (623 absorption and 905 emission line galaxies) in Field A and 1570
redshifts (569 absorption and 1001 emission line galaxies) in Field B have been
measured. The results show that it is possible to derive redshift from low SNR
galaxies with our post-processing and visual inspection. Our analysis also
indicates that up to 1/4 of the input targets for a typical extra-galactic
spectroscopic survey might be unreliable. The multi-wavelength data analysis
shows that the majority of mid-infrared-detected absorption (91.3%) and
emission line galaxies (93.3%) can be well separated by an empirical criterion
of . Meanwhile, a fainter sequence paralleled to the main population
of galaxies has been witnessed both in / and /
diagrams, which could be the population of luminous dwarf galaxies but
contaminated by the edge-on/highly inclined galaxies ().Comment: 19 pages, 14 figures, 2 MRT, accepted by ApJ
Laser-Ablated Vortex Fluidic-Mediated Synthesis of Superparamagnetic Magnetite Nanoparticles in Water Under Flow
ACS AuthorChoice - This is an open access article published under an ACS AuthorChoice License, which permits copying and redistribution of the article or any adaptations for non-commercial purposesSelective formation of only one iron oxide phase is a major challenge in conventional laser ablation process, as is scaling up the process. Herein, superparamagnetic single-phase magnetite nanoparticles of hexagonal and spheroidal-shape, with an average size of ca. 15 nm, are generated by laser ablation of bulk iron metal at 1064 nm in a vortex fluidic device (VFD). This is a one-step continuous flow process, in air at ambient pressure, with in situ uptake of the nanoparticles in the dynamic thin film of water in the VFD. The process minimizes the generation of waste by avoiding the need for any chemicals or surfactants and avoids time-consuming purification steps in reducing any negative impact of the processing on the environment.The authors gratefully acknowledge the financial support from the Australia Research Council and the Government of South Australia; also the expertise, equipment, and support provided by the Australian Microscopy and Microanalysis Research Facility (AMMRF) and the Australian National Fabrication Facility (ANFF) at the South Australian nodes of the AMMRF and ANFF under the National Collaborative Research Infrastructure Strategy
Novel Method for in Situ Monitoring of Organophosphorus Flame Retardants in Waters
Widespread use of organophosphorus flame retardants (OPFRs) and their ubiquity in water results in the need for a robust and reliable monitoring technique to better understand their fate and environmental impact. In situ passive sampling using the diffusive gradients in thin-films (DGT) technique provides time-integrated data and is developed for measuring OPFRs here. Ultrasonic extraction of binding gels in methanol provided reliable recoveries for all tested OPFRs. Diffusion coefficients of TCEP, TCPP, TDCPP, TPrP, TBP, and TBEP in the agarose diffusive gel (25 °C) were obtained. The capacity of an HLB binding gel for OPFRs was >115 Οg per disc, and the binding performance did not deteriorate with time up to 131 days. DGT performance is independent of typical environmental ranges of pH (3.12-9.71), ionic strength (0.1-500 mmol L -1 ), and dissolved organic matter (0-20 mg L -1 ), and also of diffusive layer thickness (0.64-2.14 mm) and deployment time (3-168 h). Negligible competition effects between OPFRs was found. DGT-measured concentrations of OPFRs in a wastewater treatment plant (WWTP) effluent (12-16 days) were comparable to those obtained by grab sampling, further verifying DGT's reliability for measuring OPFRs in waters
High-efficiency single-photon source above the loss-tolerant threshold for efficient linear optical quantum computing
Photon loss is the biggest enemy for scalable photonic quantum information
processing. This problem can be tackled by using quantum error correction,
provided that the overall photon loss is below a threshold of 1/3. However, all
reported on-demand and indistinguishable single-photon sources still fall short
of this threshold. Here, by using tailor shaped laser pulse excitation on a
high-quantum efficiency single quantum dot deterministically coupled to a
tunable open microcavity, we demonstrate a high-performance source with a
single-photon purity of 0.9795(6), photon indistinguishability of 0.9856(13),
and an overall system efficiency of 0.712(18), simultaneously. This source for
the first time reaches the efficiency threshold for scalable photonic quantum
computing. With this source, we further demonstrate 1.89(14) dB intensity
squeezing, and consecutive 40-photon events with 1.67 mHz count rate
Individuals with psychometric schizotypy show similar social but not physical anhedonia to patients with schizophrenia
Very few studies have examined physical and social anhedonia across the spectrum of schizophrenia. In the present study, we recruited three groups of participants (n=84 in each group): patients with schizophrenia, schizotypy and non-schizotypy as assessed by the Schizotypal Personality Questionnaire (SPQ). All participants completed the self-reported trait anhedonia scales (the Revised Physical Anhedonia Scale and the Social Anhedonia Scale). The clinical symptoms of schizophrenia patients were assessed using the Positive and Negative Syndrome Scale (PANSS) and the Scale for Assessment of Negative Symptoms (SANS). We found that the three groups differed in both physical and social anhedonia. The schizotypy group reported higher levels of physical anhedonia than the non-schizotypy group, and the patient group reported higher levels of physical anhedonia than the schizotypy group. For social anhedonia, the non-schizotypy group differed significantly from both the schizotypy and the patient group, while no significant difference was found between the last two groups. Our findings show that individuals with schizotypy exhibits similar social but not physical anhedonia compared with patients with schizophrenia, which further suggests that decreased pleasure experiences in the social environment may be a valuable target for identification and early intervention in high-risk populations, (C) 2014 Elsevier Ireland Ltd. All rights reserved
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