Assessing the impacts of fine sediment removal on endogenous pollution release and microbial community structure in the shallow lakes.

Resuspension is a crucial process for releasing endogenous pollution from shallow lakes into the overlying water. Fine particle sediment, which has a higher contamination risk and longer residence time, is the primary target for controlling endogenous pollution. To this end, a study coupling aqueous biogeochemistry, electrochemistry, and DNA sequencing was conducted to investigate the remediation effect and microbial mechanism of sediment elution in shallow eutrophic water. The results indicated that sediment elution can effectively remove some fine particles in situ. Furthermore, sediment elution can inhibit the release of ammonium nitrogen and total dissolved phosphorous into the overlying water from sediment resuspension in the early stage, resulting in reductions of 41.44 %-50.45 % and 67.81 %-72.41 %, respectively. Additionally, sediment elution greatly decreased the concentration of nitrogen and phosphorus pollutants in pore water. The microbial community structure was also substantially altered, with an increase in the relative abundance of aerobic and facultative aerobic microorganisms. Redundancy analysis, PICRUSt function prediction, and the correlation analysis revealed that loss on ignition was the primary factor responsible for driving changes in microbial community structure and function in sediment. Overall, the findings provide novel insights into treating endogenous pollution in shallow eutrophication water.

#WuhanDiary and #WuhanLockdown: gendered posting patterns and behaviours on Weibo during the COVID-19 pandemic.

Social media can be both a source of information and misinformation during health emergencies. During the COVID-19 pandemic, social media became a ubiquitous tool for people to communicate and represents a rich source of data researchers can use to analyse users' experiences, knowledge and sentiments. Research on social media posts during COVID-19 has identified, to date, the perpetuity of traditional gendered norms and experiences. Yet these studies are mostly based on Western social media platforms. Little is known about gendered experiences of lockdown communicated on non-Western social media platforms. Using data from Weibo, China's leading social media platform, we examine gendered user patterns and sentiment during the first wave of the pandemic between 1 January 2020 and 1 July 2020. We find that Weibo posts by self-identified women and men conformed with some gendered norms identified on other social media platforms during the COVID-19 pandemic (posting patterns and keyword usage) but not all (sentiment). This insight may be important for targeted public health messaging on social media during future health emergencies.

COVID-19, sex, and gender in China: a scoping review.

BACKGROUND: During the course of the COVID-19 pandemic, states were called upon by the World Health Organization to introduce and prioritise the collection of sex-disaggregated data. The collection of sex-disaggregated data on COVID-19 testing, infection rates, hospital admissions, and deaths, when available, has informed our understanding of the biology of the infectious disease. The collection of sex-disaggregated data should also better inform our understanding of the gendered impacts that contribute to risk of exposure to COVID-19. In China, the country with the longest history of fighting the COVID-19 infection, what research was available on the gender-differential impacts of COVID-19 in the first 6 months of the COVID-19 pandemic? METHODS: In this scoping review, we examine the first 6 months (January-June 2020) of peer-reviewed publications (n = 451) on sex and gender experiences related to COVID-19 in China. We conducted an exhaustive search of published Chinese and English language research papers on COVID-19 in mainland China. We used a COVID-19 Gender Matrix informed by the JPHIEGO gender analysis toolkit to examine and illuminate research into the gendered impacts of COVID-19 within China. RESULTS: In China, only a small portion of the COVID-19-related research focused on gender experiences and differences. Near the end of the six-month literature review period, a small number of research items emerged on women healthcare workers, women's mental health, and pregnant women's access to care. There was an absence of research on the gendered impact of COVID-19 amongst populations. There was minimal consideration of the economic, social and security factors, including gender stereotypes and expectations, that affected different populations' experiences of infection, treatment, and lockdown during the period of review. CONCLUSION: At the outset of health emergencies in China, gender research needs to be prioritised during the first stage of an outbreak to assist with evaluation of the most effective public health measures, identifying access to healthcare and social welfare barriers amongst priority communities. Gender stereotypes and gendered differences lead to different patterns of exposure and treatment. The exclusion of this knowledge in real time affects the design of effective prevention and recovery.

Using gender analysis matrixes to integrate a gender lens into infectious diseases outbreaks research.

Evidence shows that infectious disease outbreaks are not gender-neutral, meaning that women, men and gender minorities are differentially affected. This evidence affirms the need to better incorporate a gender lens into infectious disease outbreaks. Despite this evidence, there has been a historic neglect of gender-based analysis in health, including during health crises. Recognizing the lack of available evidence on gender and pandemics in early 2020 the Gender and COVID-19 project set out to use a gender analysis matrix to conduct rapid, real-time analyses while the pandemic was unfolding to examine the gendered effects of the coronavirus disease 2019 pandemic. This paper reports on what a gender analysis matrix is, how it can be used to systematically conduct a gender analysis, how it was implemented within the study, ways in which the findings from the matrix were applied and built upon, and challenges encountered when using the matrix methodology.

More than a public health crisis: A feminist political economic analysis of COVID-19.

Gender norms, roles and relations differentially affect women, men, and non-binary individuals' vulnerability to disease. Outbreak response measures also have immediate and long-term gendered effects. However, gender-based analysis of outbreaks and responses is limited by lack of data and little integration of feminist analysis within global health scholarship. Recognising these barriers, this paper applies a gender matrix methodology, grounded in feminist political economy approaches, to evaluate the gendered effects of the COVID-19 pandemic and response in four case studies: China, Hong Kong, Canada, and the UK. Through a rapid scoping of documentation of the gendered effects of the outbreak, it applies the matrix framework to analyse findings, identifying common themes across the case studies: financial discrimination, crisis in care, and unequal risks and secondary effects. Results point to transnational structural conditions which put women on the front lines of the pandemic at work and at home while denying them health, economic and personal security - effects that are exacerbated where racism and other forms of discrimination intersect with gender inequities. Given that women and people living at the intersections of multiple inequities are made additionally vulnerable by pandemic responses, intersectional feminist responses should be prioritised at the beginning of any crises.

Multifunctional peptide-based fluorescent chemosensor for detection of Hg2+ , Cu2+ and S2- ions.

A novel multifunctional fluorescent peptide sensor based on pentapeptide dansyl-Gly-His-Gly-Gly-Trp-COOH (D-P5) was designed and synthesized efficiently using Fmoc solid-phase peptide synthesis (SPPS). This fluorescent peptide sensor shows selective and sensitive responses to Hg2+ and Cu2+ among 17 metal ions and six anions studied in N-2-hydroxyethylpiperazine-N-2-ethane sulfonic acid (HEPES) buffer solution. The peptide probe differentiates Hg2+ and Cu2+ ions by a 'turn-on' response to Hg2+ and a 'turn-off' response to Cu2+ . Upon addition of Hg2+ or Cu2+ ions, the sensor displayed an apparent color change that was visible under an ultraviolet lamp to the naked eye. The limits of detection (LOD) of DP-5 were 25.0 nM for Hg2+ and 85.0 nM for Cu2+ ; the detection limits for Cu2+ were much lower than the drinking water maximum contaminant levels set out by the United States Environmental Protection Agency (USEPA). It is noteworthy that both D-P5-Hg and D-P5-Cu systems were also used to detect S2- successfully based on the formation of ternary complexes. The LODs of D-P5-Hg and D-P5-Cu systems for S2- were 217.0 nM and 380.0 nM, respectively. Furthermore, the binding stoichiometry, binding affinity and pH sensitivity of the probe for Hg2+ and Cu2+ were investigated. This study gives new possibilities for using a short fluorescent peptide sensor for multifunctional detection, especially for anions.

Toxicity of 7-ketocholesterol on lethality, growth, reproduction, and germline apoptosis in the nematode Caenorhabditis elegans.

7-Ketocholesterol is one of the most abundant cholesterol oxides, and is known to be cytotoxic to various types of cultured mammalian cells; however, little is known regarding its effects in vivo. With the use of the nematode Caenorhabditis elegans as model organism, in vivo toxicity of 7-ketocholesterol was investigated. The aim of the study was to examine the effects on life span, as well as short-term effects on reproduction, thermotolerance, germline apoptosis, and reactive oxygen species (ROS) generation resulting from C. elegans exposure to 7-ketocholesterol at concentrations ranging from 0 to 200 µg/ml. Results indicated that 7-ketocholesterol reduced reproductive capacity, shortened the life span in a concentration-dependent manner, and impaired thermotolerance of the adult nematode. 7-Ketocholesterol also induced germline apoptotic cell death and increased ROS generation in adult worms. Thus, the model organism C. elegans is recommended for assessment of the safety and bioactivity of cholesterol oxides.

Controlling nitrogen migration through micro-nano networks.

Nitrogen fertilizer unabsorbed by crops eventually discharges into the environment through runoff, leaching and volatilization, resulting in three-dimensional (3D) pollution spanning from underground into space. Here we describe an approach for controlling nitrogen loss, developed using loss control fertilizer (LCF) prepared by adding modified natural nanoclay (attapulgite) to traditional fertilizer. In the aqueous phase, LCF self-assembles to form 3D micro/nano networks via hydrogen bonds and other weak interactions, obtaining a higher nitrogen spatial scale so that it is retained by a soil filtering layer. Thus nitrogen loss is reduced and sufficient nutrition for crops is supplied, while the pollution risk of the fertilizer is substantially lowered. As such, self-fabrication of nano-material was used to manipulate the nitrogen spatial scale, which provides a novel and promising approach for the research and control of the migration of other micro-scaled pollutants in environmental medium.

The Caenorhabditis elegans homeobox gene ceh-19 is required for MC motorneuron function.

Simplicity has made C. elegans pharyngeal development a particularly well-studied subject. Nevertheless, here we add the previously uncharacterized homeobox gene F20D12.6/ceh-19 to the set of transcription factor genes involved. GFP reporter assays revealed that ceh-19 is expressed in three pairs of neurons, the pharyngeal pace-maker neurons MC, the amphid neurons ADF and the phasmid neurons PHA. ceh-19(tm452) mutants are viable and fertile, but grow slightly slower, produce less progeny over a prolonged period, and live longer than the wild type. These phenotypes are likely due to the moderately reduced pharyngeal pumping speed arising from the impairment of MC activity. MC neurons are still born in the ceh-19 mutants but display various morphological defects. ceh-19 expression in MC is completely lost in progeny from animals subject to RNAi for pha-4, which encodes an organ-specifying forkhead transcription factor. CEH-19 is required for the activation in MCs of the excitatory FMRFamide-like neuropeptide-encoding gene flp-2. A regulatory pathway from pha-4 through ceh-19 to flp-2 is thereby defined. The resilience of MC identity in the absence of CEH-19 may reflect the buffering qualities of transcription factor regulatory networks.

A regulatory cascade of three transcription factors in a single specific neuron, DVC, in Caenorhabditis elegans.

Homeobox proteins are critical regulators of developmental gene transcription and cell specification. Many insights into transcriptional regulation have been gained from studies in the nematode Caenorhabditis elegans. We investigated the expression and regulation of the C. elegans homeobox gene ceh-63, which encodes a single-homeodomain transcription factor of 152 amino acids. ceh-63 is expressed in the interneuron DVC in both sexes, from late embryogenesis through adulthood, and two pairs of uterine cells in reproductive hermaphrodites only. A reporter gene fusion, encoding GFP fused to the full-length CEH-63, also drove weak inconsistent expression in additional unidentified cells in the head and tail. A potential ceh-63 null mutant had no obvious abnormalities, except for a possible increase in subtle defects of the DVC axon projection. No behavioural responses were observed upon either laser ablation of DVC or activation of DVC through light stimulation of channelrhodopsin-2 specifically expressed in this neuron. The function of DVC therefore remains enigmatic. A transcriptional regulatory cascade operating in DVC was defined from the LIM-homeodomain protein CEH-14 through CEH-63 to the helix-turn-helix transcription factor MBR-1. Both CEH-14 and CEH-63 individually bound the mbr-1 promoter in a yeast one-hybrid assay. A model is proposed suggesting that CEH-14 activates ceh-63 and then along with CEH-63 co-ordinately activates mbr-1.

Expression pattern analysis of regulatory transcription factors in Caenorhabditis elegans.

Expression pattern data are fundamental to understanding transcriptional regulatory networks and the biological significance of such networks. For Caenorhabditis elegans, expression pattern analysis of transcription factor genes, with cellular resolution, typically involves generation of transcription factor gene/reporter gene fusions. This is followed by the creation of C. elegans strains transgenic for, and determination of expression patterns driven by, these fusions. Physiologically relevant regulatory relationships between transcription factors are both inferred from their expression patterns, in combination with protein-DNA interaction data, and evidenced from alterations of expression patterns when networks are disturbed.

[Research advances in global regulator LaeA of filamentous fungi--a review].

Global regulators play an important role in secondary metabolite biosynthesis and morphological development in filamentous fungi. LaeA, a key global regulator in filamentous fungi was found in 2004, regulating the expression of a variety of fungal natural product gene clusters. Besides regulation of beneficial metabolism, fungal toxin biosynthesis and morphological developmental processes, laeA also contributed to activating the expression of cryptic gene clusters and resulted in generating novel secondary metabolites. Although the mechanism of LaeA on gene activation is still unclear, it has set the stage for understanding the fungal regulatory network and discovering new natural products. This review highlight its discovery, function and regulatory mechanism in filamentous fungi.

Flocculation of harmful algal blooms by modified attapulgite and its safety evaluation.

Natural attapulgite (N-AT) and modified attapulgite (M-AT) were used in this study to evaluate their flocculation efficiencies and mechanisms in freshwater containing harmful algal blooms through conventional jar test procedure. The experimental results showed that the efficiency of flocculation can be significantly improved by M-AT under appropriate conditions. It was found that the attapulgite modified by hydrochloric acid was similar to polyaluminum ferric silicate chloride (PAFSiC). The high efficiency for M-AT to flocculate Microcystis aeruginosa in freshwater was due to the mechanism of bridging and netting effect. Caenorhabditis elegans was used to detect the toxicity of N-AT and M-AT. The results showed that there was no significant toxicity on this organism. Attapulgite is a natural material, which can be readily available, abundant, and relatively inexpensive. Using modified attapulgite to remove the harmful algal blooms could have the advantages of high effectiveness, low cost, and low impact on the environment.

A novel approach to microbial breeding--low-energy ion implantation.

Low-energy ions exist widely in the natural world. People had neglected the interaction between low-energy ions and material; it was even more out of the question to study the relation of low-energy ions and the complicated organism until the biological effects of low-energy ion implantation were discovered in 1989. Nowadays, the value of low-energy ion beam implantation, as a new breeding way, has drawn extensive attention of biologists and breeding experts. In this review, the understanding and utilization of microbial breeding by low-energy ion beam irradiation is summarized, including the characteristics of an ion beam bioengineering facility, present status of the technology of low-energy ions for microbial breeding, and new insights into microbial biotechnology.

Effects induced by keV low-energy ion irradiation in the nematode Caenorhabditis elegans.

The nematode Caenorhabditis elegans is an excellent model organism with which to study the biological effects and mechanisms of ionizing irradiation. In this study, using C. elegans as a model, the effects of keV low-energy argon ion irradiation were investigated, by examining cuticle damage, worm survival, brood size, life span, and germ cell death. The surface etching of worm cuticle after ion impact was investigated by trypan blue staining and SEM microscopy. The degree of damage increased with ion fluence (2 x 10(14) to 7 x 10(14) ions cm(-2)) and energy (5-25 keV). The survival rates, as compared to vacuum control, of ion-bombarded worm larvae at different developmental stages (L1-L4) decreased with increasing ion fluence. L1 larvae were found to be more sensitive to ion bombardment than larvae at other stages. The mean brood size in ion-bombarded groups decreased with increasing ion fluence and energy. Furthermore, keV argon ions caused a significant increase in the number of apoptotic germ cells. However, average lifespan was not significantly affected.

In situ visualization of DSBs to assess the extranuclear/extracellular effects induced by low-dose alpha-particle irradiation.

Extranuclear/extracellular effects may have a significant effect on low-dose radiation risk assessment as well as on the shape of the dose-response relationship. Numerous studies using different end points such as sister chromatid exchanges, micronuclei and mutation have shown that this phenomenon exists in many cell types. However, these end points mostly reflect the late events after radiation damage, and little is known about the early response in this phenomenon. DNA double-strand breaks (DSBs) induced by ionizing radiation or carcinogenic chemicals can be visualized in situ using gamma-H2AX immunofluorescence staining, and there is evidence that the number of gamma-H2AX foci can be closely correlated with DSBs induced. Here we used gamma-H2AX as a biomarker to assess the extranuclear/extracellular effects induced by low-dose alpha particles in situ. The results show that a greater fraction of positive cells with DSBs (48.6%) was observed than the number of cells whose nuclei were actually traversed by the 1-cGy dose of alpha particles (9.2%). The fraction of DSB-positive cells was greatly reduced after treatment with either lindane or DMSO. These results suggest that in situ visualization of DSBs can be used to assess radiation-induced extranuclear/extracellular effects soon after irradiation. Moreover, the in situ DSB assay may provide a means to evaluate the spatial effect on unirradiated cells that are located in the neighboring region of cells irradiated by alpha particles.

Survival of mammalian cells under high vacuum condition for ion bombardment.

An ion beam has been used to irradiate various organisms and its effects have been studied. Because of the poor tolerance that mammalian cells have for vacuum, such studies have not been carried out on living mammalian cells until now. However, this work is important both for elucidating the mechanism of mutation in response to low-energy ions and in exploring possible new applications of ion beam technology. The current paper describes an investigation of the survival of mammalian cells (the A(L) cell line) in a high-vacuum chamber in preparation for ion bombardment studies. The ion beam facility is described and the actual vacuum profile that the cells endured in the target chamber is reported. Cells were damaged immediately following vacuum exposure; the injury was characterized by alteration of the membrane permeability, loss of firm adhesion to the dish, and increased fragility. Three cryoprotective agents were tested (glycerol, propylene glycol, and trehalose) and of these, glycerol showed the highest potency for protecting cells against vacuum stress. This was revealed by an increase in the cell survival level from <1 to >10% with a glycerol concentration of 15 and 20%. Two glycerol-based protocols were investigated (freezing-vacuum vs. non-freezing-vacuum), but there was no significant difference (P > 0.1) in their ability to improve cell survival, the values being 10.31 +/- 4.5 and 12.7 +/- 3.37%, respectively with 20% glycerol concentration. These cells had a normal growth capability, and also retained integrity of the cell surface antigen CD59. These initial experiments indicate that mammalian cells can withstand vacuum to the degree that is needed to study the effect of the ion beam. In addition to the improvements made in this study, other factors are discussed that may increase the survival of mammalian cells exposed to a vacuum in future studies.