Intensive fishing can strongly impact marine ecosystems; among other things, it usually causes the mean trophic level of the catches to decline, an indicator of the occurrence of the 'fishing down' ...(FD) phenomenon. Although FD occurs throughout the world oceans, it can easily be masked by diverse factors, which has misled authors as to its generality. In this contribution, which uses the East China Sea as an example, we explore the masking effect on FD of the taxonomic coarseness of catch data, of assuming that individual sizes remain constant after intensive fishing, and the geographic expansion of fisheries. The result showed that all of these masking factors occur in the East China Sea, where only a few species are reported separately and the bulk of the catch is pooled into non-informative 'mixed fishes'. Also, the small mesh sizes and intensive fishing have reduced the sizes of fish and their trophic levels, while the fisheries have expanded offshore. Overall, taking the masking factors into account, the fishing down effect, i.e., the decline of the mean trophic level of the catch between 1979 and 2014 is in the order of 0.15 TL per decade, i.e., one of the highest estimates of FD in the world. Some ecological implications are presented.
To develop and validate a radiomics nomogram for preoperative prediction of lymph node (LN) metastasis in patients with colorectal cancer (CRC).
The prediction model was developed in a primary cohort ...that consisted of 326 patients with clinicopathologically confirmed CRC, and data was gathered from January 2007 to April 2010. Radiomic features were extracted from portal venous-phase computed tomography (CT) of CRC. Lasso regression model was used for data dimension reduction, feature selection, and radiomics signature building. Multivariable logistic regression analysis was used to develop the predicting model, we incorporated the radiomics signature, CT-reported LN status, and independent clinicopathologic risk factors, and this was presented with a radiomics nomogram. The performance of the nomogram was assessed with respect to its calibration, discrimination, and clinical usefulness. Internal validation was assessed. An independent validation cohort contained 200 consecutive patients from May 2010 to December 2011.
The radiomics signature, which consisted of 24 selected features, was significantly associated with LN status (P < .001 for both primary and validation cohorts). Predictors contained in the individualized prediction nomogram included the radiomics signature, CT-reported LN status, and carcinoembryonic antigen level. Addition of histologic grade to the nomogram failed to show incremental prognostic value. The model showed good discrimination, with a C-index of 0.736 (C-index, 0.759 and 0.766 through internal validation), and good calibration. Application of the nomogram in the validation cohort still gave good discrimination (C-index, 0.778 95% CI, 0.769 to 0.787) and good calibration. Decision curve analysis demonstrated that the radiomics nomogram was clinically useful.
This study presents a radiomics nomogram that incorporates the radiomics signature, CT-reported LN status, and clinical risk factors, which can be conveniently used to facilitate the preoperative individualized prediction of LN metastasis in patients with CRC.
In the past decade, advances in liquid chromatography‐mass spectrometry (LC‐MS) have revolutionized untargeted metabolomics analyses. By mining metabolomes more deeply, researchers are now primed to ...uncover key metabolites and their associations with diseases. The employment of untargeted metabolomics has led to new biomarker discoveries and a better mechanistic understanding of diseases with applications in precision medicine. However, many major pertinent challenges remain. First, compound identification has been poor, and left an overwhelming number of unidentified peaks. Second, partial, incomplete metabolomes persist due to factors such as limitations in mass spectrometry data acquisition speeds, wide‐range of metabolites concentrations, and cellular/tissue/temporal‐specific expression changes that confound our understanding of metabolite perturbations. Third, to contextualize metabolites in pathways and biology is difficult because many metabolites partake in multiple pathways, have yet to be described species specificity, or possess unannotated or more‐complex functions that are not easily characterized through metabolomics analyses. From a translational perspective, information related to novel metabolite biomarkers, metabolic pathways, and drug targets might be sparser than they should be. Thankfully, significant progress has been made and novel solutions are emerging, achieved through sustained academic and industrial community efforts in terms of hardware, computational, and experimental approaches. Given the rapidly growing utility of metabolomics, this review will offer new perspectives, increase awareness of the major challenges in LC‐MS metabolomics that will significantly benefit the metabolomics community and also the broader the biomedical community metabolomics aspire to serve.
This paper presents a multi-input-multi-output (MIMO) range migration algorithm (RMA) with range compensation for near-field millimeter-wave imaging. The proposed algorithm is derived based on the ...effective phase center principle and scalar diffraction theory. Compared with the original MIMO RMA, the propagation loss is compensated better, and the reconstructed image quality is improved significantly. In the process of image reconstruction, a multistatic array topology is transformed to a monostatic array, and the round-trip propagation is converted into unidirectional optical field propagation. The efficiency of the proposed algorithm is analyzed theoretically, and demonstrated experimentally. Numerical simulations and experimental results show that the propagation loss in range is properly compensated by the proposed algorithm.
Fibrous materials usually have good mechanical, heat-resistant, acid-resistant, alkali-resistant and moisture regained properties which originate from its composition, condensed structure and ...crosslinking styles. However, these materials often lack of good electrical conductivity, flame retardance, anti-static and anti-radiation properties which are desired for varied specific applications. Graphene, as a new emerging nanocarbon material, has some unique properties including superb thermal and electrical conductivity, strong mechanical and anti-corrosive property, extremely high surface area etc. Therefore, graphene has attracted extensive interests in recent years. Upon modification with graphene, fibers exhibit a number of enhanced or new properties such as adsorption performance, anti-bacteria, hydrophobicity and conductivity which are beneficial for broader applications. In this review, the strategies to modify the fibers with graphene and the corresponding effects on the fibers as well as the relevant applications in varied areas were discussed.
Summary
In flowering plants, the interaction of pollen tubes with female tissues is important for the accomplishment of double fertilization. Little information is known about the mechanisms that ...underlie signalling between pollen tubes and female tissues. In this study, two Arabidopsis pollen tube‐expressed CrRLK1L protein kinases, Buddha's Paper Seal 1 (BUPS1) and BUPS2, were identified as being required for normal tip growth of pollen tubes in the pistil. They are expressed prolifically in pollen and pollen tubes and are localized on the plasma membrane of the pollen tube tip region. Mutations in BUPS1 drastically reduced seed set. Most of the bups1 mutant pollen tubes growing in the pistil exhibited a swollen pollen tube tip, leading to failure of fertilization. The bups2 pollen tubes had a slightly abnormal morphology but could still accomplish double fertilization. The bups1 bups2 double mutant exhibited a slightly enhanced phenotype compared to the single bups1 mutants. The BUPS1 proteins could form homomers and heteromers with BUPS2, whereas BUPS2 could only form heteromers with BUPS1. The BUPS proteins could interact with the Arabidopsis pollen‐expressed RopGEFs in the yeast two‐hybrid (Y2H) and bimolecular fluorescence complementation (BiFC) assays. The results indicated that the BUPSs may mediate normal polar growth of pollen tubes in the pistil.
Significance Statement
The pollen‐expressed CrRLK1L Protein Kinases BUPSs are important for normal tip growth of pollen tubes in the Arabidopsis pistil. They might interact with the pollen‐expressed RopGEFs and might mediate the interaction of the pollen tube with the female tissues in pollen tube growth.
We aimed to assess the acute effects of ambient air pollution and weather conditions on mortality in the context of Chinese smog episodes. A total of 209,321 deaths were recorded in Jinan, a large ...city in eastern China, during 2011-15. The mean concentrations of daily particulate matter ≤10 μm (PM
), fine particulate matter (PM
), sulfur dioxide (SO
) and nitrogen dioxide (NO
) were 169 μg/m
, 100 μg/m
, 77 μg/m
, and 54 μg/m
, respectively. Increases of 10 μg/m
in PM
, PM
, SO
and NO
were associated with 1.11% (95% CI 0.96-1.26%), 0.71% (95% CI 0.60-0.82%), 1.69% (95% CI 1.56-1.83%), and 3.12% (95% CI 2.72-3.53%) increases in daily non-accidental mortality rates, respectively. Moreover, the risk estimates for these 4 pollutants were higher in association with respiratory and cardiovascular mortality. The effects of all the evaluated pollutants on mortality were greater in winter than in summer. Smog episodes were associated with a 5.87% (95% CI 0.16-11.58%) increase in the rate of overall mortality. This study highlights the effect of exposure to air pollution on the rate of mortality in China.
Millimeter-wave imaging systems are increasingly used in human screening at checkpoints, in linear or multi-input multi-output (MIMO) array modes. Rather than pressing intrinsic system requirements ...to improve image quality, it seems more economical to appeal to some specific approaches, for example, super-resolution (SR) techniques. In this paper, as a variation of SR, coherence factor (CF) is incorporated in the framework of the range migration algorithm (RMA), termed CF-RMA for short. As a critical part of CF, the double integral in the wavenumber domain is approximated by a single integral in the sense of the point-matching method, resulting in a particular formulation to carry on another independent RMA program. Being computationally efficient, the proposed method is shown to be effective in suppressing sidelobes and background noise. The resolution (as gauged by the width of the main lobe of the point spread function) is enhanced as well. A structural similarity (SSIM) index is employed to quantify the image quality enhancement with respect to state-of-the-art SR approaches. In terms of computation load, the new approach is shown to be much more efficient than state-of-the-art SR approaches.
Objectives
Terahertz (THz)‐based imaging techniques hold great potential for biological and biomedical applications, which nevertheless are hampered by the low spatial resolution of conventional THz ...imaging systems. In this work, we report a high‐performance photoconductive antenna microprobe‐based near‐field THz time‐domain spectroscopy scanning microscope.
Materials and methods
A single watermelon pulp cell was prepared on a clean quartz slide and covered by a thin polyethylene film. The high performance near‐field THz microscope was developed based on a coherent THz time‐domain spectroscopy system coupled with a photoconductive antenna microprobe. The sample was imaged in transmission mode.
Results
We demonstrate the direct imaging of the morphology of single watermelon pulp cells in the natural dehydration process with our near‐field THz microscope.
Conclusions
Given the label‐free and non‐destructive nature of THz detection techniques, our near‐field microscopy‐based single‐cell imaging approach sheds new light on studying biological samples with THz.
The shear behaviors of granular mixtures are studied using the discrete element method. These granular materials contain real gravel-shaped coarse particles and spherical fine particles. Dense ...samples have been created by the isotropic compression method. The samples are then sheared under drained triaxial compression to a large strain to determine the peak and residual shear strengths. The emphasis of this study is placed on assessing the evolutions of contributions of the coarse-coarse (CC) contacts, coarse-fine (CF) contacts and fine-fine (FF) contacts to the peak and critical deviator stresses. The results are used to classify the structure of granular mixtures. Specifically, the granular mixtures are fine-dominated or coarse-dominated materials when the coarse particle content is <30%–40% or >65%–70%, respectively. A comparison with previous findings suggests that the spherical binary mixtures will become coarse-dominated materials at a relatively larger coarse particle content (i.e., 75%–80%) than this study (i.e., 65%–70%), which is attributed to the particle shape effect of coarse particles. A microscopic analysis of CC, CF and FF contacts at the peak and critical states, including normal contact forces and proportions of strong and weak contacts of each contact type to total contacts, reveals why the contributions of CC, CF and FF contacts to the peak and residual shear strengths are varied. Finally, a detailed analysis of the anisotropies indicates that the increases of peak and residual shear strengths are primarily related to the gradual increases in geometrical anisotropy ac and tangential contact force anisotropy at to compensate for the continuous decrease in normal contact force anisotropy an. Furthermore, it is interesting to note that the branch vector frame provides a better linear relationship between the stress ratio and the geometric anisotropy of the strong and nonsliding subnetwork than the contact frame for the coarse-dominated materials.
Display omitted
•Effect of coarse particle content on shear strength of binary mixtures is studied.•Structure of mixtures is classified by order of contact type on deviator stress.•Microscopic mechanisms of variation of contact type to deviator stress is revealed.•Variation of shear strength can be highlighted by the anisotropic analysis.
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