Amundsen Sea Ice Loss Contributes to Australian Wildfires

Wildfires in Australia have attracted extensive attention in recent years, especially for the devastating 2019-2020 fire season. Remote forcing, such as those from tropical oceans, plays an important role in driving the abnormal weather conditions associated with wildfires. However, whether high latitude climate change can impact Australian fires is largely unclear. In this study, we reveal a robust relationship between Antarctic sea ice concentration (SIC), primarily over the Amundsen Sea region, with Australian springtime fire activity, by using reanalysis data sets, AMIP simulation results, and a state-of-the-art climate model simulation. Specifically, a diminished Amundsen SIC leads to the formation of a high-pressure system above Australia as a result of the eastward propagation of Rossby waves. Meanwhile, two strengthened meridional cells originating from the tropic and polar regions also enhance subsiding airflow in Australia, resulting in prolonged arid and high-temperature conditions. This mechanism explains about 28% of the variability of Australian fire weather and contributed more than 40% to the 2019 extreme burning event, especially in the eastern hotspots. These findings contribute to our understanding of polar-low latitude climate teleconnection and have important implications for projecting Australian fires as well as the global environment.

Breast ultrasound image despeckling using multi-filtering DFrFT and adaptive fast BM3D

Improving the quality of breast ultrasound images is of great significance for clinical diagnosis which can greatly boost the diagnostic accuracy of ultrasonography. However, due to the influence of ultrasound imaging principles and acquisition equipment, the collected ultrasound images naturally contain a large amount of speckle noise, which leads to a decrease in image quality and affects clinical diagnosis. To overcome this problem, we propose an improved denoising algorithm combining multi-filter DFrFT (Discrete Fractional Fourier Transform) and the adaptive fast BM3D (Block Matching and 3D collaborative filtering) method. Firstly, we provide the multi-filtering DFrFT method for preprocessing the original breast ultrasound image so as to remove some speckle noise early in fractional transformation domain. Based on the fractional frequency spectrum characteristics of breast ultrasound images, three types of filters are designed correspondingly in low, medium, and high frequency domains. And by integrating filtered images, the enhanced images are obtained which not only remove some speckle noise in background but also preserve the details of breast lesions. Secondly, for further enhancing the image quality on the basis of multi-filter DFrFT, we propose the adaptive fast BM3D method by introducing the DBSCAN-based super pixel segmentation to block matching process, which utilizes super pixel segmentation labels to provide a reference on how similar it is between target block and retrieval blocks. It reduces the number of blocks to be retrieved and make the matched blocks with more similar features. At last, the local noise parameter estimation is also adopted in the hard threshold filtering process of traditional BM3D algorithm to achieve local adaptive filtering and further improving the denoising effect. The synthetic data and real breast ultrasound data examples show that this combined method can improve the speckle suppression level and keep the fidelity of structure effectively without increasing time cost.

[Epidemiological investigation of constipation in urban areas of Hangzhou, China]

Objective: To determine the prevalence and risk factors of constipation in Hangzhou urban areas by analyzing data from a recent epidemiological survey. Methods: From August 2022 to June 2023, a cross-sectional survey was conducted on 43 communities on eight streets in suburbs of Hangzhou, including Wangjiang, Sijiqing, Puyan, Changhe, Ziyang, Xiaoshanchengxiang, Zhuantang, and Banshan. Written questionnaires were filled out face to face by community doctors. The prevalence of constipation was investigated using a combination of the Bristol stool typing method and the Rome IV criteria. The risk factors for constipation were analyzed using multivariate logistic regression analysis. Results: The study cohort comprised 10,479 participants, 5551 of whom were male (53.0%) and 4928 female (47.0%). The overall prevalence of constipation was 10.6% (1107/10,479). The prevalence was 11.0% (613/5551) for male and 10.0% (494/4928) for female participants; this difference is not statistically significant (P>0.05).There were no significant differences in the prevalence of constipation between different categories of body mass index (P>0.05). The prevalence of constipation was highest in individuals aged 70 years and above, accounting for 15.4% (264/1717) of all cases. There were significant differences in the prevalence of constipation between different occupations, marital statuses, and educational levels (P<0.001). Patients with hypertension or diabetes mellitus had a higher prevalence of constipation than those without these conditions, those who had been taking long-term medication had a higher prevalence of constipation than those who did not, parents of children with constipation had a higher prevalence of constipation than those with children who did not have constipation, and there were other significant differences in various variables (P<0.001). Multivariate logistic regression analysis of modifiable factors revealed that eating less fruit (OR=1.284, 95%CI: 1.061-1.553, P=0.010), liking spicy and salty food (OR=1.234, 95%CI: 1.039-1.466, P=0.016), sleeping for too long (OR=1.644, 95%CI: 1.260-2.144, P<0.001), irregular sleep patterns (OR=1.370, 95%CI: 1.127-1.665, P=0.002) and minimal exercise (OR=1.388, 95% CI: 1.168-1.649, P<0.001) were all risk factors for constipation; whereas mix diets (OR=0.709,95%CI:0.608-0.826, P<0.001), meat diets (OR=0.604,95%CI: 0.495-0.736, P<0.001), moderate alcohol consumption (OR=0.659, 95% CI: 0.534-0.812, P<0.001), less or no drinking (OR=0.523, 95% CI: 0.428-0.638, P<0.001), and non-smoking (OR=0.819, 95%CI:0.674-0.995, P<0.001) protected against constipation. We found no association between dietary preferences and the risk of constipation (refined grains: OR=1.147, 95%CI:0.944-1.393, P=0.167; no specific preference: OR=0.935, 95%CI:0.783-1.117, P=0.459). The rate of agreement between self-evaluation of constipation by the respondents and objective criteria was higher for negatives (95.8%) than for positives (38.0%). Conclusion: The prevalence of constipation is relatively high in the urban population of Hangzhou. A good lifestyle and diet can significantly reduce its incidence. There should be more emphasis on preventive education, promotion of prevention of constipation, and advocacy for a healthy lifestyle.

Increased aerosol scattering contributes to the recent monsoon rainfall decrease over the Gangetic Plain

The climate effects of atmospheric aerosols remain highly uncertain. Part of the uncertainty arises from the fact that scattering and absorbing aerosols have distinct or even opposite effects. Thus their relative fraction is critical in determining the overall aerosol climate effect. This study combines observations and global model simulations to demonstrate that changes in the fraction of scattering and absorbing aerosols play an important role in driving the monsoon precipitation decrease over northern India since the 1980s, especially over the Gangetic Basin. Increased aerosol scattering, or decreased aerosol absorption, manifested as a significant increase of aerosol single scattering albedo (SSA), causes strong cooling in the upper atmosphere. This suppresses vertical convection and thus reduces precipitation. Further analysis of the Couple Model Intercomparison Project Phase 6 multi-model-mean historical simulation shows that failing to capture the SSA increase over northern India is likely an important cause of the simulated precipitation trend bias in this area.

The shift of decadal trend in Middle East dust activities attributed to North Tropical Atlantic variability

The Middle East, as the world's second-largest dust source region, has dust emissions that significantly impact numerous populated areas, extending from North America to South Asia. Over the past two decades, dust activity in the Middle East has exhibited pronounced variability, with a notable trend shift from positive to negative around 2010. The underlying cause of this trend shift remains elusive. In this study, we employ multi-source datasets and global climate model simulations to demonstrate that the variability of Middle East dust activities is closely tied to changes in North Tropical Atlantic (NTA) sea surface temperature (SST). Specifically, a warm NTA SST anomaly generates an anomalous regional zonal cell characterized by ascending air motion above the NTA and descending air surrounding the Middle East. The associated surface high pressures around the Middle East subsequently induce hot and dry conditions accompanied by intensified Shamal winds in the north, which are favorable for dust emission and transport. The shift in SST trends from positive to negative in the NTA around 2010 is therefore responsible for the observed dust trend shift in the Middle East. This mechanism holds vital implications for predicting decadal dust variability over the Middle East region and further the project of global environment.

Higgs Mode of Planar Coupled Spin Ladders and its Observation in C_{9}H_{18}N_{2}CuBr_{4}

Polarized inelastic neutron scattering experiments recently identified the amplitude (Higgs) mode in C_{9}H_{18}N_{2}CuBr_{4}, a two-dimensional near-quantum-critical spin-1/2 two-leg ladder compound, which exhibits a weak easy-axis exchange anisotropy. Here, we theoretically examine the dynamic spin structure factor of such planar coupled spin-ladder systems using large-scale quantum Monte Carlo simulations. This allows us to provide a quantitative account of the experimental neutron scattering data within a consistent quantum spin model. Moreover, we trace the details of the continuous evolution of the amplitude mode from a two-particle bound state of coupled ladders in the classical Ising limit all the way to the quantum spin-1/2 Heisenberg limit with fully restored SU(2) symmetry, where it gets overdamped by the two-magnon continuum in neutron scattering.

Cloning and characterization of an apoptosis-related DNA fragmentation factor (DFF) from oyster, Crassostrea hongkongensis

Apoptosis plays an important pathophysiological role in the homeostasis of immune systems. DNA fragmentation factors (DFFs) have been shown to be essential for DNA fragmentation, and the resultant DNA fragments follow a laddering pattern during apoptosis in vertebrates. In invertebrates, the functions of the DFF orthologs are not well characterized; therefore, we cloned and characterized a bivalve DFFA ortholog from the Hong Kong oyster Crassostrea hongkongensis (designated ChDFFA). The full-length cDNA of ChDFFA is 1186 bp in length and encodes a putative protein of 200 amino acids that contains an N-terminal CAD domain and a DFF-C domain at its C-terminus. Real-time RT-PCR results showed that ChDFFA is ubiquitously expressed in several tissues, and its highest expression is in gill. Following a 3- to 48-h challenge by microbial infection, the expression of ChDFFA increased in hemocytes. Using fluorescence microscopy, ChDFFA was localized in nuclei when exogenously expressed in HeLa cells. In addition, over-expression of ChDFFA inhibited the transcriptional activities of p53/p21-Luc reporter genes in HEK293T cells. These results suggest that ChDFFA may be involved in immune response reactions in the Hong Kong oyster C. hongkongensis.

Analysis of the ethylene response in the epinastic mutant of tomato

Ethylene can alter plant morphology due to its effect on cell expansion. The most widely documented example of ethylene-mediated cell expansion is promotion of the "triple response" of seedlings grown in the dark in ethylene. Roots and hypocotyls become shorter and thickened compared with controls due to a reorientation of cell expansion, and curvature of the apical hook is more pronounced. The epinastic (epi) mutant of tomato (Lycopersicon esculentum) has a dark-grown seedling phenotype similar to the triple response even in the absence of ethylene. In addition, in adult plants both the leaves and the petioles display epinastic curvature and there is constitutive expression of an ethylene-inducible chitinase gene. However, petal senescence and abscission and fruit ripening are all normal in epi. A double mutant (epi/epi;Nr/Nr) homozygous for both the recessive epi and dominant ethylene-insensitive Never-ripe loci has the same dark-grown seedling and vegetative phenotypes as epi but possesses the senescence and ripening characteristics of Never-ripe. These data suggest that a subset of ethylene responses controlling vegetative growth and development may be constitutively activated in epi. In addition, the epi locus has been placed on the tomato RFLP map on the long arm of chromosome 4 and does not demonstrate linkage to reported tomato CTR1 homologs.