Application of Fenton, photo-Fenton, solar photo-Fenton, and UV/H2O2 to degradation of the antineoplastic agent mitoxantrone and toxicological evaluation

In the present study, selected advanced oxidation processes (AOPs)—namely, photo-Fenton (with Fe²⁺, Fe³⁺, and potassium ferrioxalate—FeOx—as iron sources), solar photo-Fenton, Fenton, and UV/H₂O₂—were investigated for degradation of the antineoplastic drug mitoxantrone (MTX), frequently used to treat metastatic breast cancer, skin cancer, and acute leukemia. The results showed that photo-Fenton processes employing Fe(III) and FeOx and the UV/H₂O₂ process were most efficient for mineralizing MTX, with 77, 82, and 90 % of total organic carbon removal, respectively. MTX probably forms a complex with Fe(III), as demonstrated by voltammetric and spectrophotometric measurements. Spectrophotometric titrations suggested that the complex has a 2:1 Fe³⁺:MTX stoichiometric ratio and a complexation constant (K) of 1.47 × 10⁴ M^–1, indicating high MTX affinity for Fe³⁺. Complexation partially inhibits the involvement of iron ions and hence the degradation of MTX during photo-Fenton. The UV/H₂O₂ process is usually slower than the photo-Fenton process, but, in this study, the UV/H₂O₂ process proved to be more efficient due to complexing of MTX with Fe(III). The drug exhibited no cytotoxicity against NIH/3T3 mouse embryonic fibroblast cells when oxidized by UV/H₂O₂ or by UV/H₂O₂/FeOx at the concentrations tested.     

Is Daily Mortality Associated Specifically with Fine Particles? Data Reconstruction and Replication of Analyses

ABSTRACT

In 1996, Schwartz, Dockery, and Neas¹ reported that daily mortality was more strongly associated with concentrations of PM_2.5 than with concentrations of larger particles (coarse mass [CM]) in six U.S. cities (“original paper'V'original analyses”). Because of the public policy implications of the findings and the uniqueness of the concentration data, we undertook a reanalysis of these results. This paper presents results of the reconstruction of these data and replication of the original analyses using the reconstructed data. The original investigators provided particulate air pollution data for this paper. Daily weather and daily counts of total and cause-specific deaths were reconstructed from original public records. The reconstructed particulate air pollution and weather data were consistent with the summaries presented in the original paper. Daily counts of deaths in the reconstructed data set were lower than in the original paper because of restrictions on residence and place of death. The reconstruction process identified an administrative change in county codes that led to higher numbers of deaths in St. Louis. Despite these differences in daily counts of deaths, the estimated effects of par-ticulate air pollution from the reconstructed dataset, using analytic methods as described in the original paper, produced combined effect estimates essentially equivalent to the originally published results. For example, the estimated association of a 10 |j.g/m³ increase in 2-day mean particulate air pollution on total mortality was 1.3% (95% confidence interval [CI] 0.9-1.7%, t = 6.53) for PM₂₅ based on the reconstructed dataset, compared to the originally reported association of 1.5% (95% CI 1.1-1.9%, t = 7.41). For coarse particles, the estimated association from the reconstructed dataset was 0.4% (95% CI -0.2-0.9%, t = 1.43) compared to the originally reported association of 0.4% (95% CI -0.1-1.0%, t = 1.48). These results from the reconstructed data suggest that the original results reported by Schwartz, Dockery, and Neas¹ were essentially replicated.     

Detection of presumed genes encoding beta-lactamases by sequence based screening of metagenomes derived from Antarctic microbial mats

• Beta-lactamase genes were found in all samples from distant places in Antarctica. • Class C beta-lactamase coding genes were the most frequently found. • Diversity of sequences exceeds that of the beta-lactamases from clinical environment. Analysis of environmental samples for bacterial antibiotic resistance genes may have different objectives and analysis strategies. In some cases, the purpose was to study diversity and evolution of genes that could be grouped within a mechanism of antibiotic resistance. Different protocols have been designed for detection and confirmation that a functional gene was found. In this study, we present a sequence-based screening of candidate genes encoding beta-lactamases in 14 metagenomes of Antarctic microbial mats. The samples were obtained from different sites, representing diverse biogeographic regions of maritime and continental Antarctica. A protocol was designed based on generation of Hidden Markov Models from the four beta-lactamase classes by Ambler classification, using sequences from the Comprehensive Antibiotic Resistance Database (CARD). The models were used as queries for metagenome analysis and recovered contigs were subsequently annotated using RAST. According to our analysis, 14 metagenomes analyzed contain A, B and C beta-lactamase genes. Class D genes, however, were identified in 11 metagenomes. The most abundant was class C (46.8%), followed by classes B (35.5%), A (14.2%) and D (3.5%). A considerable number of sequences formed clusters which included, in some cases, contigs from different metagenomes. These assemblies are clearly separated from reference clusters, previously identified using CARD beta-lactamase sequences. While bacterial antibiotic resistance is a major challenge of public health worldwide, our results suggest that environmental diversity of beta-lactamase genes is higher than that currently reported, although this should be complemented with gene function analysis.     

SNOTEL,the Soil Climate Analysis Network,and water supply forecasting at the Natural Resources Conservation Service: Past,present, and future

The Snow Survey and Water Supply Forecasting (SSWSF) Program and the Soil Climate Analysis Network (SCAN) of the United States Department of Agriculture's Natural Resources Conservation Service (NRCS) generate key observational and predictive information for water managers. Examples include mountain climate and snow monitoring through manual snow surveys and the SNOw TELemetry (SNOTEL) and SNOtel LITE networks, in situ soil moisture data acquisition through the SCAN and SNOTEL networks, and water supply forecasting using river runoff prediction models. The SSWSF Program has advanced continuously over the decades and is a major source of valuable water management information across the western United States, and the SCAN network supports agricultural and other water users nationwide. Product users and their management goals are diverse, and use-cases range from guiding crop selection to seasonal flood risk assessment, drought monitoring and prediction, avalanche and fire prediction, hydropower optimization, tracking climate variability and change, environmental management, satisfying international treaty and domestic legal requirements, and more. Priorities going forward are to continue innovating to enhance the accuracy and completeness of the observational and model-generated data products these programs deliver, including expanded synergies with the remote sensing community and uptake of artificial intelligence while maintaining long-term operational reliability and consistency at scale.     

Three-dimensional visualization and quantification of non-aqueous phase liquid volumes in natural porous media using a medical X-ray Computed Tomography scanner

This study demonstrates the capabilities of a typical medical X-ray Computed Tomography (CT) scanner to non-destructively quantify non-aqueous phase liquid (NAPL) volumes, saturation levels, and three-dimensional spatial distributions in packed soil columns. Columns packed with homogeneous sand, heterogeneous sand, or natural soil, were saturated with water and injected with known quantities of gasoline or tetrachloroethene and scanned. A methodology based on image subtraction was implemented for computing soil porosity and NAPL volumes in each 0.35 mm x 0.35 mm x 1 mm voxel of the columns. Elimination of sample positioning errors and instrument drift artifacts was essential for obtaining reliable estimates of above parameters. The CT data-derived total NAPL volume was in agreement with the measured NAPL volumes injected into the columns. CT data-derived NAPL volume is subject to a 2.6% error for PCE and a 15.5% error for gasoline, at average NAPL saturations as low as 5%, and is mainly due to instrument noise. Non-uniform distributions of NAPL due to preferential flow, and accumulation of NAPL above finer-grained layers could be observed from the data on 3-D distributions of NAPL volume fractions.     

Assessing species reintroduction sites based on future climate suitability for food resources

The reintroduction of a species that is extinct in the wild demands caution because reintroduction locations may be associated with threats, such as hunting, poor-quality habitat, and climate change. This is the case for Cyanopsitta spixii (Spix's Macaw), which has been extinct in the wild since 2000. The few living individuals were created in captivity and will be used in a reintroduction project within the species’ original distribution area, the Caatinga domain (Brazil). Because the occurrence records for this bird are old and inaccurate, we investigated the current and future environmental suitability of the 14 plant species used by C. spixii as resource. These plants are key elements for the long-term reestablishment of the species in the wild, so the use of models helps in the assessment of the effects of climate change on the availability of these resources for the species and informs selection of the best places for reintroduction. We based our models of environmental suitability on 19 bioclimatic variables and nine physical soil and topography variables. Climate projections were created for the present and for the year 2070 with an optimistic (SSP2-4.5) and a pessimistic (SSP5-8.5) climate scenario. Both future climate scenarios lead to a reduction in area of environmental suitability that overlapped for all the plant species: 33% reduction for SSP2-4.5 and 63% reduction for SSP5-8.5. If our projections materialize, climate change could thus affect the distribution of key resources, and the maintenance of C. spixii would depend on restoration of degraded areas, especially riparian forests, and the preservation of already existing natural areas. The Caatinga domain is very threatened by habitat loss and, for the success of this reintroduction project, the parties involved must act to protect the species and the resources it uses.     

Performance evaluation of an in situ source area combined remedy for the remediation of commingled chlorinated ethanes and ethenes

The chlorinated volatile organic compounds (CVOCs), tetrachloroethene (PCE), trichloroethene (TCE), and 1,1,1‐trichloroethane (1,1,1‐TCA), often found as commingled contaminants of concern (COCs) in groundwater, can degrade via a variety of biotic and abiotic reductive pathways. In situ remediation of a groundwater contaminant source area containing commingled 1,1,1‐TCA, PCE, and TCE was conducted using a combined remedy/treatment train approach. The first step was to create geochemically reducing conditions in the source area to degrade the CVOCs to lesser chlorinated CVOCs (i.e., 1,1‐dichloroethane [1,1‐DCA], 1,1‐dichlorethene [1,1‐DCE], cis‐1,2‐dichoroethene [cis‐1,2‐DCE], and vinyl chloride [VC]) via enhanced reductive dechlorination (ERD). Carbon substrates were injected to create microbial‐induced geochemically reducing conditions. An abiotic reductant (zero‐valent iron [ZVI]) was also used to further degrade the CVOCs, minimizing the generation of 1,1‐DCE and VC, and co‐precipitate temporarily mobilized metals. An in situ aerobic zone was created downgradient of the treatment zone through the injection of oxygen. Remaining CVOC degradation products and temporarily mobilized metals (e.g., iron and manganese) resulting from the geochemically reducing conditions were then allowed to migrate through the aerobic zone. Within the aerobic zone, the lesser chlorinated CVOCs were oxidized and the solubilized metals were precipitated out of solution. The injection of a combination of carbon substrates and ZVI into the groundwater system at the site studied herein resulted in the generation of a geochemically reducing subsurface treatment zone that has lasted for more than 4.5 years. Mass concentrations of total CVOCs were degraded within the treatment zone, with near complete transformation of chlorinated ethenes and a more than 90 percent reduction of CVOC mass concentrations. Production of VC and 1,1‐DCE has been minimized through the combined effects of abiotic and biological processes. CVOC concentrations have declined over time and temporarily mobilized metals are precipitating out of the dissolved phase. Precipitation of the dissolved metals was mitigated using the in situ oxygenation system, also resulting in a return to aerobic conditions in downgradient groundwater. Chloroethane (CA) is the dominant CVOC degradation product within the treatment zone and downgradient of the treatment zone, and it is expected to continue to aerobically degrade over time. CA did not accumulate within and near the aerobic oxygenation zone. The expectations for the remediation system are: (1) the concentrations of CVOCs (primarily in the form of CA) will continue to degrade; (2) total organic carbon concentrations will continue to decline to pre‐remediation levels; and, (3) the groundwater geochemistry will experience an overall trend of transitioning from reducing back to pre‐remediation mildly oxidizing conditions within and downgradient of the treatment zone.     

Defending dissensus: participatory governance and the politics of water measurement in Montana’s Yellowstone River Basin

The role of a particular aspect of collaboration, dissensus, in stimulating critical reconsideration of ‘prior appropriation’, a historically hegemonic condition related to water rights in the western United States, is examined via a collaborative planning effort in Montana. Consensual support for a water-use measuring proposal was undermined by strong libertarian resistance to governmental regulation, and an unwavering embrace of the status quo. However, based on insights from scholars engaged in the ‘post-political’ dimensions of contemporary forms of rule – dissensus – understood as the manifestation of consensus-forestalling disagreement articulated between oppositional voices – is revealed as a condition to be actively nurtured, rather than purged. This case reveals how dissensus can open discursive spaces for hegemony-disrupting modes of inquiry, alternative perspectives, and innovative possibilities, even among sanctioned participant voices operating within otherwise established, depoliticized governing arenas. The study thus deepens our understanding of the complex political dynamics of participatory water planning.     

A new method for analysing socio-ecological patterns of vulnerability

This paper presents a method for the analysis of socio-ecological patterns of vulnerability of people being at risk of losing their livelihoods as a consequence of global environmental change. This method fills a gap in methodologies for vulnerability analysis by providing generalizations of the factors that shape vulnerability in specific socio-ecological systems and showing their spatial occurrence. The proposed method consists of four steps that include both quantitative and qualitative analyses. To start, the socio-ecological system exposed to global environmental changes that will be studied needs to be determined. This could, for example, be farmers in drylands, urban populations in coastal areas and forest-dependent people in the tropics. Next, the core dimensions that shape vulnerability in the socio-ecological system of interest need to be defined. Subsequently, a set of spatially explicit indicators that reflect these core dimensions is selected. Cluster analysis is used for grouping the indicator data. The clusters found, referred to as vulnerability profiles, describe different typical groupings of conditions and processes that create vulnerability in the socio-ecological system under study, and their spatial distribution is provided. Interpretation and verification of these profiles is the last step in the analysis. We illustrate the application of this method by analysing the patterns of vulnerability of (smallholder) farmers in drylands. We identify eight distinct vulnerability profiles in drylands that together provide a global overview of different processes taking place and sub-national detail of their distribution. By overlaying the spatial distribution of these profiles with specific outcome indicators such as conflict occurrence or migration, the method can also be used to understand these phenomena better. Analysis of vulnerability profiles will in a next step be used as a basis for identifying responses to reduce vulnerability, for example, to facilitate the transfer of best practices to reduce vulnerability between different places.     

Chronic dietary exposure to pyrolytic and petrogenic mixtures of PAHs causes physiological disruption in zebrafish - part I: Survival and growth

The release of polycyclic aromatic hydrocarbons (PAHs) into the environment has increased very substantially over the last decades leading to high concentrations in sediments of contaminated areas. To evaluate the consequences of long-term chronic exposure to PAHs, zebrafish were exposed, from their first meal at 5 days post fertilisation until they became reproducing adults, to diets spiked with three PAH fractions at three environmentally relevant concentrations with the medium concentration being in the range of 4.6–6.7 μg g^?1 for total quantified PAHs including the 16 US-EPA indicator PAHs and alkylated derivatives. The fractions used were representative of PAHs of pyrolytic (PY) origin or of two different oils of differing compositions, a heavy fuel (HO) and a light crude oil (LO). Fish growth was inhibited by all PAH fractions and the effects were sex specific: as determined with 9-month-old adults, exposure to the highest PY inhibited growth of females; exposure to the highest HO and LO inhibited growth of males; also, the highest HO dramatically reduced survival. Morphological analysis indicated a disruption of jaw growth in larvae and malformations in adults. Intestinal and pancreatic enzyme activities were abnormal in 2-month-old exposed fish. These effects may contribute to poor growth. Finally, our results indicate that PAH mixtures of different compositions, representative of situations encountered in the wild, can promote lethal and sublethal effects which are likely to be detrimental for fish recruitment.