419 research outputs found
Spraying exogenous hormones alleviate impact of weak-light on yield by improving leaf carbon and nitrogen metabolism in fresh waxy maize
Insufficient light during the growth periods has become one of the main factors restricting maize yield with global climate change. Exogenous hormones application is a feasible measure to alleviate abiotic stresses on crop productivity. In this study, a field trial was conducted to investigate the effects of spraying exogenous hormones on yield, dry matter (DM) and nitrogen (N) accumulation, leaf carbon and N metabolism of fresh waxy maize under weak-light stress in 2021 and 2022. Five treatments including natural light (CK), weak-light after pollination (Z), spraying water (ZP1), exogenous Phytase Q9 (ZP2) and 6-benzyladenine (ZP3) under weak-light after pollination were set up using two hybrids suyunuo5 (SYN5) and jingkenuo2000 (JKN2000). Results showed that weak-light stress significantly reduced the average fresh ear yield (49.8%), fresh grain yield (47.9%), DM (53.3%) and N accumulation (59.9%), and increased grain moisture content. The net photosynthetic rate (Pn), transpiration rate (Tr) of ear leaf after pollination decreased under Z. Furthermore, weak-light decreased the activities of RuBPCase and PEPCase, nitrate reductase (NR), glutamine synthetase (GS), glutamate synthase (GOGAT), superoxide dismutase (SOD), catalase (CAT) and peroxidase (POD) in ear leaves, and increased malondialdehyde (MDA) accumulation. And the decrease was greater on JKN2000. While ZP2 and ZP3 treatments increased the fresh ear yield (17.8%, 25.3%), fresh grain yield (17.2%, 29.5%), DM (35.8%, 44.6%) and N (42.5%, 52.4%) accumulation, and decreased grain moisture content compared with Z. The Pn, Tr increased under ZP2 and ZP3. Moreover, the ZP2 and ZP3 treatments improved the activities of RuBPCase, PEPCase; NR, GS, GOGAT; SOD, CAT, POD in ear leaves, and decreased MDA content during grain filling stage. The results also showed the mitigative effect of ZP3 was greater than ZP2, and the improvement effect was more significant on JKN2000
Extended ammonia observations towards the 'Integral-Shaped Filament'
Recent observations suggest a scenario in which filamentary structures in the
ISM represent the first step towards clumps/cores and eventually star
formation. The densest filaments would then fragment into prestellar cores
owing to gravitational instability. We seek to understand the roles filamentary
structures play in high-mass star formation. We mapped the integral-shaped
filament (ISF) in NH3 (1, 1) and (2, 2). The whole filamentary structure is
uniformly and fully sampled. We find that the morphology revealed by the map of
velocity-integrated intensity of the NH3 (1, 1) line is closely associated with
the dust ridge. We identify 6 "clumps" related to the well known OMC-1 to 5 and
11 "sub-clumps" within the map and they are separated not randomly but in
roughly equal intervals along the ISF. The average spacing of clumps is
11.30'1.31' (1.360.16 pc ) and the average spacing of sub-clumps is
7.18'1.19' (0.860.14 pc). These spacings agree well with the
predicted values of the thermal (0.86 pc) and turbulent sausage instability
(1.43 pc) by adopting a cylindric geometry of the ISF with an inclination of
with respect to the line of sight. We also find a velocity
gradient of about 0.6 km s-1 pc-1 that runs along the ISF which likely arises
from an overall rotation of the Orion A molecular cloud. The inferred ratio
between rotational and gravitational energy is well below unity. Furthermore,
fluctuations are seen in the centroid velocity diagram along the ISF. The OMC-1
to 5 clouds are located close to the local extrema of the fluctuations, which
suggests that there exist gas flows associated with these clumps in the ISF.
The derived NH3 (1, 1) and (2, 2) rotation temperatures in the OMC-1 are about
30-40 K. In OMC-2, OMC-3, and the northern part of OMC-4, we find higher and
lower temperatures at the boundaries and in the interior, respectively.Comment: Accepted by A&A. 14 pages, 14 figure
Investigating Sulfur Chemistry in the HD 163296 disk
Sulfur chemistry in the formation process of low-mass stars and planets
remains poorly understood. The protoplanetary disks (PPDs) are the birthplace
of planets and its distinctive environment provides an intriguing platform for
investigating models of sulfur chemistry. We analyzed the ALMA observations of
CS 7-6 transitions in the HD 163296 disk and perform astrochemical modeling to
explore its sulfur chemistry. We simulated the distribution of
sulfur-containing molecules and compared it with observationally deduced
fractional column densities. We have found that the simulated column density of
CS is consistent with the observationally deduced fractional column densities,
while the simulated column density of CS is lower than the observationally
deduced upper limits on column densities. This results indicate that we have a
good understanding of the chemical properties of CS and CS in the disk. We
also investigated the influence of the C/O ratio on sulfur-containing molecules
and found that the column densities of SO, SO, and HS near the central
star are dependent on the C/O ratio. Additionally, we found that the
[CS]/[SO] ratio can serve as a promising indicator of the disk's C/O
ratio in the HD 163296. Overall, the disk of HD 163296 provides a favorable
environment for the detection of sulfur-containing molecules.Comment: 16 pages, 7 figure
Towards the in-situ Trunk Identification and Length Measurement of Sea Cucumbers via B\'{e}zier Curve Modelling
We introduce a novel vision-based framework for in-situ trunk identification
and length measurement of sea cucumbers, which plays a crucial role in the
monitoring of marine ranching resources and mechanized harvesting. To model sea
cucumber trunk curves with varying degrees of bending, we utilize the
parametric B\'{e}zier curve due to its computational simplicity, stability, and
extensive range of transformation possibilities. Then, we propose an end-to-end
unified framework that combines parametric B\'{e}zier curve modeling with the
widely used You-Only-Look-Once (YOLO) pipeline, abbreviated as TISC-Net, and
incorporates effective funnel activation and efficient multi-scale attention
modules to enhance curve feature perception and learning. Furthermore, we
propose incorporating trunk endpoint loss as an additional constraint to
effectively mitigate the impact of endpoint deviations on the overall curve.
Finally, by utilizing the depth information of pixels located along the trunk
curve captured by a binocular camera, we propose accurately estimating the
in-situ length of sea cucumbers through space curve integration. We established
two challenging benchmark datasets for curve-based in-situ sea cucumber trunk
identification. These datasets consist of over 1,000 real-world marine
environment images of sea cucumbers, accompanied by B\'{e}zier format
annotations. We conduct evaluation on SC-ISTI, for which our method achieves
mAP50 above 0.9 on both object detection and trunk identification tasks.
Extensive length measurement experiments demonstrate that the average absolute
relative error is around 0.15
Enhancing production efficiency through optimizing plant density in maize–soybean strip intercropping
IntroductionDue to limited arable land resources, intercropping has emerged as an efficient and sustainable production method for increasing total grain yield per unit land area. Maize–soybean strip intercropping (MSSI) technology is being widely promoted and applied across China. However, the combination of optimal density for achieving higher production efficiency of both soybean and maize remains unclear. The objective of this study was to evaluate the differences in yield, economic benefits, land, and nitrogen (N) efficiency in MSSI systems under different densities.MethodsFive maize/soybean density combinations (67,500/97,500 plants ha−1, D1; 67,500/120,000 plants ha−1, D2; 67,500/142,500 plants ha−1, D3; 60,000/142,500 plants ha−1, D4; 52,500/142,500 plants ha−1, D5) were set under the same N input in the field experiment.Results and discussionThe results demonstrated that optimizing the density in the intercropping system could enhance production efficiency. Increasing the density of soybean and maize significantly increased the total grain yield (D3 > D2 > D1 > D4 > D5). The D3 treatment, exhibiting the best comprehensive performance, also promoted increases in leaf area index, dry matter accumulation, and N absorption and utilization. Path analysis indicated that density had the most substantial impact on maize yield, while grain number had the greatest influence on soybean yield, with contribution rates of 49.7% and 61.0%, respectively. These results provide valuable insights into optimal field density for summer planting in MSSI, facilitating its wider adoption
Elevated monocyte-to-HDL cholesterol ratio predicts post-stroke depression
ObjectivesInflammation plays an important role in the development of depression after stroke. Monocyte-to-HDL Cholesterol Ratio (MHR) recently emerged as a novel comprehensive inflammatory indicator in recent years. This study aimed to investigate whether there is a relationship between MHR levels and post-stroke depression (PSD).MethodsFrom February 2019 to September 2021, patients with acute ischemic stroke (AIS) were recruited within 7 days post-stroke from the two centers and blood samples were collected after admission. The 17-item Hamilton Depression Scale (HAMD-17) was used to measure depressive symptoms at 3 months after stroke. Patients were given the DSM-V criteria for diagnosis of PSD.ResultsOf the 411 enrolled patients, 92 (22.38%) patients were diagnosed with PSD at 3-months follow-up. The results also showed significantly higher level of MHR in patients with depression [0.81 (IQR 0.67–0.87) vs. 0.61 (IQR 0.44–0.82), P < 0.001] at admission than patients without depression. Multivariate logistic regression revealed that MHR (OR 6.568, 95% CI: 2.123–14.565, P = 0.015) was an independent risk factor for the depression at 3 months after stroke. After adjustment for potential confounding factors, the odds ratio of PSD was 5.018 (95% CI: 1.694–14.867, P = 0.004) for the highest tertile of MHR compared with the lowest tertile. Based on the ROC curve, the optimal cut-off value of MHR as an indicator for prediction of PSD was projected to be 0.55, which yielded a sensitivity of 87% and a specificity of 68.3%, with the area under the curve at 0.660 (95% CI: 0.683–0.781; P = 0.003).ConclusionElevated level of MHR was associated with PSD at 3 months, suggesting that MHR might be a useful Inflammatory markers to predict depression after stroke
Ammonia observations towards the Aquila Rift cloud complex
We surveyed the Aquila Rift complex including the Serpens South and W40
region in the NH(1,1) and (2,2) transitions making use of the Nanshan 26-m
telescope. The kinetic temperatures of the dense gas in the Aquila Rift complex
range from 8.9 to 35.0K with an average of 15.36.1K. Low gas temperatures
associate with Serpens South ranging from 8.9 to 16.8K with an average
12.31.7K, while dense gas in the W40 region shows higher temperatures
ranging from 17.7 to 35.0K with an average of 25.14.9 K. A comparison of
kinetic temperatures against HiGal dust temperatures indicates that the gas and
dust temperatures are in agreement in the low mass star formation region of
Serpens South. In the high mass star formation region W40, the measured gas
kinetic temperatures are higher than those of the dust. The turbulent component
of the velocity dispersion of NH(1,1) is found to be positively correlated
with the gas kinetic temperature, which indicates that the dense gas may be
heated by dissipation of turbulent energy. For the fractional total-NH3
abundance obtained by a comparison with Herschel infrared continuum data
representing dust emission we find values from 0.1 to 21 with
an average of 6.9. Serpens South also shows a
fractional total-NH3 abundance ranging from 0.2 to 21 with an
average of 8.6(. In W40, values are lower, between 0.1
and 4.3 with an average of 1.6(. Weak
velocity gradients demonstrate that the rotational energy is a negligible
fraction of the gravitational energy. In W40, gas and dust temperatures are not
strongly dependent on the projected distance to the recently formed massive
stars. Overall, the morphology of the mapped region is ring-like, with strong
emission at lower and weak emission at higher Galactic longitudes
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