Influence of vegetation on sediment bacterial community structure, microbial enzyme activities and phosphorus retention in constructed freshwater wetlands

Agricultural activities are major sources of non-point pollutants causing eutrophication. Constructed wetlands are used as a best management practice for sequestration of nutrients from agricultural runoff. This dissertation focuses on the influence of vegetation on bacterial community structure, microbial enzyme activities, and phosphorus retention capacity of constructed wetland systems. A greenhouse experiment was conducted using unvegetated or vegetated mesocosms with Juncus effusus, Carex lurida or Dichanthelium acuminatum var. acuminatum in monoculture or mixed culture. To study the influence of vegetation on the bacterial community structure and microbial enzyme activities, sediment samples were taken from monoculture mesocosms in the greenhouse. β-1,4-glucosidase, phosphatase, and N-acetylglucosaminidase activities were similar for all the samples. Phenol oxidase and peroxidase activities were higher in the unvegetated sediments. Bacterial communities were dominated by Acidobacteria, Proteobacteria and Firmicutes groups. Fewer sequences affiliated with the Firmicutes and Alphaproteobacteria were recovered from unvegetated sediments. Mesocosms were later dosed in August 2007 with 2.5mg/L of phosphorus to study the influence of vegetation on microbial enzyme activities in phosphorus-loaded wetlands. Sediment samples were collected on days 1, 14, 28, 42 and 56 after dosing. The results from this study show that the presence of plants can have a negative impact on the activity of phosphatase, phenol oxidase and peroxidase enzymes. To study phosphorus retention rates, mesocosms in the greenhouse were dosed with 2.5 mg/L of phosphorus for six months in 2008 and 2009. This was folloby a decomposition experiment to study the release of phosphorus due to plant senescence. The net removal rate was highest for mixed culture (82% in 2008 and 77% in 2009) and C. lurida in monoculture (82% in 2008 and 80% in 2009). Vegetated mesocosms (except for monoculture of D. acuminatum) shohigher removal rate compared to unvegetated mesocosms. Results recommend the use of J. effusus and C. lurida (either grown as monoculture or mixed culture) as plants that could be used for the efficient removal of phosphorus in constructed wetlands. This information indicates that a focused selection of plants can improve the effectiveness of constructed wetlands

Mosquitoes can harbour yeasts of clinical significance and contribute to their environmental dissemination

There is still a lack of studies on fungal microbiota in mosquitoes, compared with the number available on bacterial microbiota. This study reports the identification of yeasts of clinical significance in laboratory mosquito species: Anopheles gambiae, Anopheles stephensi, Culex quinquefasciatus, Aedes albopictus and Aedes aegypti. Among the yeasts isolated, they focused on the opportunistic pathogen Candida parapsilosis, since there is a need to better understand breakthrough candidaemia with resistance to the usual antifungals, which requires careful consideration in the broad-spectrum therapy, as documented in many clinical reports. C. parapsilosis occurs widely and has been isolated from diverse sources, including insects, which may contribute to its dissemination. In this study, it was isolated from the gut of An. gambiae and its presence in developmental stages and organs of different mosquito species was studied. Our results indicated that there was a stable association between C. parapsilosis and reared mosquitoes during the entire life cycle, and in adult male and female gut and gonads. A wide occurrence of C. parapsilosis was also documented in several populations of wild mosquitoes. Based on these findings, it can be said that mosquitoes might participate in the spreading of this opportunistic pathogen, not only as a carrier

Diet Complexity and Estrogen Receptor β Status Affect the Composition of the Murine Intestinal Microbiota

ABSTRACT Intestinal microbial dysbiosis contributes to the dysmetabolism of luminal factors, including steroid hormones (sterones) that affect the development of chronic gastrointestinal inflammation and the incidence of sterone-responsive cancers of the breast, prostate, and colon. Little is known, however, about the role of specific host sterone nucleoreceptors, including estrogen receptor β (ERβ), in microbiota maintenance. Herein, we test the hypothesis that ERβ status affects microbiota composition and determine if such compositionally distinct microbiota respond differently to changes in diet complexity that favor Proteobacteria enrichment. To this end, conventionally raised female ERβ +/+ and ERβ −/− C57BL/6J mice (mean age of 27 weeks) were initially reared on 8604, a complex diet containing estrogenic isoflavones, and then fed AIN-76, an isoflavone-free semisynthetic diet, for 2 weeks. 16S rRNA gene surveys revealed that the fecal microbiota of 8604-fed mice and AIN-76-fed mice differed, as expected. The relative diversity of Proteobacteria , especially the Alphaproteobacteria and Gammaproteobacteria , increased significantly following the transition to AIN-76. Distinct patterns for beneficial Lactobacillales were exclusive to and highly abundant among 8604-fed mice, whereas several Proteobacteria were exclusive to AIN-76-fed mice. Interestingly, representative orders of the phyla Proteobacteria , Bacteroidetes , and Firmicutes , including the Lactobacillales , also differed as a function of murine ERβ status. Overall, these interactions suggest that sterone nucleoreceptor status and diet complexity may play important roles in microbiota maintenance. Furthermore, we envision that this model for gastrointestinal dysbiosis may be used to identify novel probiotics, prebiotics, nutritional strategies, and pharmaceuticals for the prevention and resolution of Proteobacteria -rich dysbiosis

Sub-lethal concentrations of CdCl2 disrupt cell migration and cytoskeletal proteins in cultured mouse TM4 Sertoli cells

The aims of this study were to examine the effects of CdCl2 on the viability, migration and cytoskeleton of cultured mouse TM4 Sertoli cells. Time- and concentration-dependent changes were exhibited by the cells but 1 µM CdCl2 was sub-cytotoxic at all time-points. Exposure to 1 and 12 µM CdCl2 for 4 h resulted in disruption of the leading edge, as determined by chemical staining. Cell migration was inhibited by both 1 and 12 µM CdCl2 in a scratch assay monitored by live cell imaging, although exposure to the higher concentration was associated with cell death. Western blotting and immunofluorescence staining indicated that CdCl2 caused a concentration dependent reduction in actin and tubulin levels. Exposure to Cd2+ also resulted in significant changes in the levels and/or phosphorylation status of the microtubule and microfilament destabilising proteins cofilin and stathmin, suggesting disruption of cytoskeletal dynamics. Given that 1-12 µM Cd2+ is attainable in vivo, our findings are consistent with the possibility that Cd2+ induced impairment of testicular development and reproductive health may involve a combination of reduced Sertoli cell migration and impaired Sertoli cell viability depending on the timing, level and duration of exposure

Minimal information for studies of extracellular vesicles (MISEV2023): From basic to advanced approaches

Extracellular vesicles (EVs), through their complex cargo, can reflect the state of their cell of origin and change the functions and phenotypes of other cells. These features indicate strong biomarker and therapeutic potential and have generated broad interest, as evidenced by the steady year-on-year increase in the numbers of scientific publications about EVs. Important advances have been made in EV metrology and in understanding and applying EV biology. However, hurdles remain to realising the potential of EVs in domains ranging from basic biology to clinical applications due to challenges in EV nomenclature, separation from non-vesicular extracellular particles, characterisation and functional studies. To address the challenges and opportunities in this rapidly evolving field, the International Society for Extracellular Vesicles (ISEV) updates its 'Minimal Information for Studies of Extracellular Vesicles', which was first published in 2014 and then in 2018 as MISEV2014 and MISEV2018, respectively. The goal of the current document, MISEV2023, is to provide researchers with an updated snapshot of available approaches and their advantages and limitations for production, separation and characterisation of EVs from multiple sources, including cell culture, body fluids and solid tissues. In addition to presenting the latest state of the art in basic principles of EV research, this document also covers advanced techniques and approaches that are currently expanding the boundaries of the field. MISEV2023 also includes new sections on EV release and uptake and a brief discussion of in vivo approaches to study EVs. Compiling feedback from ISEV expert task forces and more than 1000 researchers, this document conveys the current state of EV research to facilitate robust scientific discoveries and move the field forward even more rapidly

Fermi Large Area Telescope Performance after 10 Years of Operation

The Large Area Telescope (LAT), the primary instrument for the Fermi Gamma-ray Space Telescope (Fermi) mission, is an imaging, wide field-of-view, high-energy gamma-ray telescope, covering the energy range from 30 MeV to more than 300 GeV. We describe the performance of the instrument at the 10 yr milestone. LAT performance remains well within the specifications defined during the planning phase, validating the design choices and supporting the compelling case to extend the duration of the Fermi mission. The details provided here will be useful when designing the next generation of high-energy gamma-ray observatories

Reducing the environmental impact of surgery on a global scale: systematic review and co-prioritization with healthcare workers in 132 countries

Background Healthcare cannot achieve net-zero carbon without addressing operating theatres. The aim of this study was to prioritize feasible interventions to reduce the environmental impact of operating theatres. Methods This study adopted a four-phase Delphi consensus co-prioritization methodology. In phase 1, a systematic review of published interventions and global consultation of perioperative healthcare professionals were used to longlist interventions. In phase 2, iterative thematic analysis consolidated comparable interventions into a shortlist. In phase 3, the shortlist was co-prioritized based on patient and clinician views on acceptability, feasibility, and safety. In phase 4, ranked lists of interventions were presented by their relevance to high-income countries and low–middle-income countries. Results In phase 1, 43 interventions were identified, which had low uptake in practice according to 3042 professionals globally. In phase 2, a shortlist of 15 intervention domains was generated. In phase 3, interventions were deemed acceptable for more than 90 per cent of patients except for reducing general anaesthesia (84 per cent) and re-sterilization of ‘single-use’ consumables (86 per cent). In phase 4, the top three shortlisted interventions for high-income countries were: introducing recycling; reducing use of anaesthetic gases; and appropriate clinical waste processing. In phase 4, the top three shortlisted interventions for low–middle-income countries were: introducing reusable surgical devices; reducing use of consumables; and reducing the use of general anaesthesia. Conclusion This is a step toward environmentally sustainable operating environments with actionable interventions applicable to both high– and low–middle–income countries

Reducing the environmental impact of surgery on a global scale: systematic review and co-prioritization with healthcare workers in 132 countries

Abstract Background Healthcare cannot achieve net-zero carbon without addressing operating theatres. The aim of this study was to prioritize feasible interventions to reduce the environmental impact of operating theatres. Methods This study adopted a four-phase Delphi consensus co-prioritization methodology. In phase 1, a systematic review of published interventions and global consultation of perioperative healthcare professionals were used to longlist interventions. In phase 2, iterative thematic analysis consolidated comparable interventions into a shortlist. In phase 3, the shortlist was co-prioritized based on patient and clinician views on acceptability, feasibility, and safety. In phase 4, ranked lists of interventions were presented by their relevance to high-income countries and low–middle-income countries. Results In phase 1, 43 interventions were identified, which had low uptake in practice according to 3042 professionals globally. In phase 2, a shortlist of 15 intervention domains was generated. In phase 3, interventions were deemed acceptable for more than 90 per cent of patients except for reducing general anaesthesia (84 per cent) and re-sterilization of ‘single-use’ consumables (86 per cent). In phase 4, the top three shortlisted interventions for high-income countries were: introducing recycling; reducing use of anaesthetic gases; and appropriate clinical waste processing. In phase 4, the top three shortlisted interventions for low–middle-income countries were: introducing reusable surgical devices; reducing use of consumables; and reducing the use of general anaesthesia. Conclusion This is a step toward environmentally sustainable operating environments with actionable interventions applicable to both high– and low–middle–income countries