Relation between the relative abundance and collapse of Aphanizomenon flos-aquae and microbial antagonism in Upper Klamath Lake, Oregon.

Aphanizomenon flos-aquae (AFA) is the dominant filamentous cyanobacterium that develops into blooms in Upper Klamath Lake, Oregon, each year. During AFA bloom and collapse, ecosystem conditions for endangered Lost River and shortnose suckers deteriorate, thus motivating the need to identify processes that limit AFA abundance and decline. Here, we investigate the relations between AFA and other members of the microbial community (photosynthetic and nonphotosynthetic bacteria and archaea), how those relations impact abundance and collapse of AFA, and the types of microbial conditions that suppress AFA. We found significant spatial variation in AFA relative abundance during the 2016 bloom period using 16S rRNA sequencing. The Pelican Marina site had the lowest AFA relative abundance, and this was coincident with increased relative abundance of Candidatus Sericytochromatia, Flavobacterium, and Rheinheimera, some of which are known AFA antagonists. The AFA collapse coincided with phosphorus limitation relative to nitrogen and the increased relative abundance of Cyanobium and Candidatus Sericytochromatia, which outcompete AFA when dissolved inorganic nitrogen is available. The data collected in this study indicate the importance of dissolved inorganic nitrogen combined with microbial community structure in suppressing AFA abundance.

Microbial community response to a bioaugmentation test to degrade trichloroethylene in a fractured rock aquifer, Trenton, N.J.

Bioaugmentation is a promising strategy for enhancing trichloroethylene (TCE) degradation in fractured rock. However, slow or incomplete biodegradation can lead to stalling at degradation byproducts such as 1,2-dichloroethene (cis-DCE) and vinyl chloride (VC). Over the course of 7 years, we examined the response of groundwater microbial populations in a bioaugmentation test where an emulsified vegetable oil solution (EOS®) and a dechlorinating consortium (KB-1®), containing the established dechlorinator Dehalococcoides (DHC), were injected into a TCE-contaminated fractured rock aquifer. Indigenous microbial communities responded within 2 days to added substrate and outcompeted KB-1®, and over the years of monitoring, several other notable turnover events were observed. Concentrations of ethene, the end product in reductive dechlorination, had the strongest correlations (P< .05) with members of Candidatus Colwellbacteria but their involvement in reductive dechlorination is unknown and warrants further investigation.DHC never exceeded 0.6% relative abundance of groundwater microbial communities, despite its previously presumed importance at the site. Increased concentrations of carbon dioxide, acetic acid, and methane were positively correlated with increasing ethene concentrations; however, concentrations of cis-DCE and VC remained high by the end of the monitoring period suggesting preferential enrichment of indigenous partial dechlorinators over bioaugmented complete dechlorinators. This study highlights the importance of characterizing in situ microbial populations to understand how they can potentially enhance or inhibit augmented TCE degradation.

What relates to length of stay in a sober living home among women with histories of victimization and addiction? A longitudinal analysis.

Despite preliminary research suggesting that length of stay in sober living homes (SLHs) is related to sustained sobriety, little research has examined factors that relate to length of stay in SLHs. The purpose of the proposed exploratory study was to prospectively examine baseline characteristics of women with histories of addiction and victimization as correlates of length of stay in a trauma-informed, gender-responsive SLH. Participants (N = 45) were surveyed three times over a 1-year period. Women were invited to participate within a week of their arrival to the SLH. Nearly two-thirds (62.2%, n = 28) of women stayed under 3 months, and 37.8% (n = 17) of women stayed over 3 months. Whereas older age and greater financial worries were associated with staying over 3 months at the SLH, other variables (e.g., demographics, mental health, recent victimization, recent substance use) were unrelated. Findings indicate that efforts may be needed to ensure that younger women as well as women with less financial worries, who may be less likely to stay for longer periods of times at SLHs, have adequate support for sobriety.

Recovery homes provide inexpensive and accessible community-based support.

Substance abuse disorders (SUDs) create significant and pervasive health and economic burdens in the U.S. and the world. After primary treatment has ended, supportive social environments are critically important to prevent relapse and to sustain long-term sobriety. Although approaches to SUDs and treatment vary internationally, studies in the United States indicate that a major risk factor for SUD relapse are lack of social environments to support sustained remission from substance use after primary treatment has ended. Evidence suggests that abstinence is enhanced when individuals are embedded in drug-free settings that support abstinence. Longabaugh, Beattie, Noel, and Stout proposed a theory of social support that engages two processes: general social support, which affectspsychological functioning, and abstinence-specific social support, which supports ongoing abstinence from substance use.

An exploratory study of Romanians' attitudes toward community-based substance abuse recovery housing.

This study reports results of a measure of a Romanian community's attitudes toward addiction and the hypothetical creation of self-run substance abuse recovery homes called Oxford Houses in Iași, Romania. We list five factors needed to sustain an Oxford House: affordable housing, residents following OH principles, resident income, institutional support, and community support. Because individual Oxford Houses are located in ordinary residential neighborhoods, they rely in part on community support. Descriptive data analyses provided information on four groups based on participants' status: (1) no contact with someone with alcohol misuse; (2) having a potentially alcohol addicted person(s) in their family; (3) definitely having alcohol addicted person(s) in their family; and (4) having an addicted alcohol in recovery person(s) in their family. Results indicated Romanian's favorable attitude toward alcohol addiction as a treatable condition, benefits of being part of an Oxford House, Oxford House rules and principles, and willingness to organize or to participate in events for integrating Oxford House residents into the community. These findings suggest that Oxford House could potentially be accepted by neighborhood residents in Iași, Romania, and this research could inform future efforts to create Oxford Houses in Romania.

Volume outlier benchmark proposal for Australian Mohs surgery.

Peer-derived Australian Mohs data were used to define volume outliers and a benchmark for quality improvement. Higher volume practice was linked to less complex anatomical locations for surgery. Reflection on individual practice compared to peers may reduce the number of volume outliers in Mohs surgery.

Challenges and Rewards of Conducting Research on Recovery Residences for Alcohol and Drug Disorders.

Although research shows treatment for alcohol and drug problems can be effective, persons without stable housing that supports recovery are at risk for relapse. Recovery residences (RRs) for drug and alcohol problems are a growing response to the need for alcohol- and drug-free living environments that support sustained recovery. Research on RRs offers an opportunity to examine how integration of these individuals into a supportive, empowering environment has beneficial impacts on substance use, housing, and other outcomes, as well as benefits for the surrounding community. Research can also lead to the identification of operations and practices within houses that maximize favorable outcomes for residents. However, research on RRs also presents significant obstacles and challenges. Based on our experiences conducting recovery home research for decades, we present suggestions for addressing some of the unique challenges encountered in this type of research.

Substance abuse relapse in Oxford House recovery homes: A survival analysis evaluation.

BACKGROUND: This study used survival analysis to examine risk factors for substance abuse relapse among residents in Oxford Houses (OH), a national network of self-run, self-financed aftercare homes for individuals recovering from substance use disorders. METHODS: Participants who entered OH within 60 days of a 1-year longitudinal study (N = 268) were selected from of a nationally representative US sample. Discrete-time survival analysis compared baseline risk of relapse with 4 hypothesized survival models that included time-invariant and time-varying factors across 3 subsequent time periods. RESULTS: The model predicting higher risk for more severe substance use disorders and psychiatric problems was supported. The hypothesized model that predicted time-varying increases in alcohol (but not drug) abstinence self-efficacy significantly affected risk of relapse. Hypothesized demographic and employment variables did not significantly predict relapse risk. CONCLUSIONS: Results suggested that OH recovery homes may reduce relapse by providing closer monitoring and referring additional services to new residents with more severe prior addiction severity. Risk for relapse may also be reduced by enhancing abstinence self-efficacy for alcohol regardless of drug of choice.

Important Activities Among Justice-Involved Individuals with Substance Use Disorders in Posttreatment Aftercare Settings.

This study gathered data using the Important Persons and Activities instrument to record changes in popular activities over a 2-year study of 270 justice-involved individuals randomized into three aftercare conditions: self-run Oxford Houses, a staffed therapeutic community (TC), or usual aftercare (UA). Participants listed important activities during the 2-year study at baseline and at four subsequent 6-month intervals. Categorization of these activities and a descriptive analysis were conducted for Wave 1 (baseline), at Wave 3 (Year 1), and Wave 5 (Year 2). Standardized scores were computed to test differences in proportions of the #1 most favored activity across conditions. Descriptive results also demonstrated that Reading/Writing activities, and Exercise/Sports activities, were most reported at baseline. By Wave 5, Education/Work and Interacting with Others were the most reported activities. These findings indicated that solitary activities, such as Reading/Writing, may play a predominant role in early aftercare whereas Work/Education and social activities increase later on. Implications for future research of changing activities during recovery trajectories are discussed.

Importance of the Colmation Layer in the Transport and Removal of Cyanobacteria, Viruses, and Dissolved Organic Carbon during Natural Lake-Bank Filtration.

This study focused on the importance of the colmation layer in the removal of cyanobacteria, viruses, and dissolved organic carbon (DOC) during natural bank filtration. Injection-and-recovery studies were performed at two shallow (0.5 m deep), sandy, near-shore sites at the southern end of Ashumet Pond, a waste-impacted, kettle pond on Cape Cod, MA, that is subject to periodic blooms of cyanobacteria and continuously recharges a sole-source drinking-water aquifer. The experiment involved assessing the transport behaviors of bromide (conservative tracer), sp. IU625 (cyanobacterium, 2.6 ± 0.2 µm), AS-1 (tailed cyanophage, 110 nm long), MS2 (coliphage, 26 nm diameter), and carboxylate-modified microspheres (1.7 µm diameter) introduced to the colmation layer using a bag-and-barrel (Lee-type) seepage meter. The injectate constituents were tracked as they were advected across the pond water-groundwater interface and through the underlying aquifer sediments under natural-gradient conditions past push-point samplers placed at ∼30-cm intervals along a 1.2-m-long, diagonally downward flow path. More than 99% of the microspheres, IU625, MS2, AS-1, and ∼44% of the pond DOC were removed in the colmation layer (upper 25 cm of poorly sorted bottom sediments) at two test locations characterized by dissimilar seepage rates (1.7 vs. 0.26 m d). Retention profiles in recovered core material indicated that >82% of the attached IU625 were in the top 3 cm of bottom sediments. The colmation layer was also responsible for rapid changes in the character of the DOC and was more effective (by three orders of magnitude) at removing microspheres than was the underlying 20-cm-thick segment of sediment.

Leadership Styles of Oxford House Officers.

Oxford House recovery homes are unusual compared to most recovery homes in that they function entirely without the use of staff; instead members are elected to officer positions. The aim of this study was to perform preliminary analysis of the types of leadership styles utilized by members of oxford house. Twentynine house residents of five Oxford Houses were asked to rate their own leadership styles using the leader behavior description questionnaire and the multifactor leader questionnaire. Results showed that participants were more likely to use person-oriented behaviors above task-oriented actions. Transformational leadership was associated with higher outcomes than Transactional leadership. Implications for future research are discussed.

Factors Affecting the Sustainability of Self-Run Recovery Homes in the United States.

This study examined the sustainability rates of 214 self-run substance abuse recovery homes called Oxford Houses (OHs) over a six-year period. We list five factors needed to sustain an OH: affordable housing, residents following OH principles, resident income, institutional support, and community support. Results indicated a high sustainability rate (86.9%) in which 186 OHs remained open and 28 OHs closed. Reasons for houses closing (N = 14) included lack of affordable housing, which we classified as an external factor. Houses that closed because of internal factors (N = 13) included residents who were unable to adhere to OH rules, and insufficient income of residents. No house-level differences for income, sense of community, average lengths of stay, house age, or neighborhood characteristics were found between the houses that closed versus houses that remained open. Because the OH system relies on residents to sustain individual houses located in ordinary residential neighborhoods, these findings suggest that OH sustainability depends on locale, primarily access to affordable housing and adequate job opportunities for residents.

Effects on groundwater microbial communities of an engineered 30-day in situ exposure to the antibiotic sulfamethoxazole.

Effects upon microbial communities from environmental exposure to concentrations of antibiotics in the µg L(-1) range remain poorly understood. Microbial communities from an oligotrophic aquifer (estimated doubling rates of only once per week) that were previously acclimated (AC) or unacclimated (UAC) to historical sulfamethoxazole (SMX) contamination, and a laboratory-grown Pseudomonas stutzeri strain, were exposed to 240-520 µg L(-1) SMX for 30 days in situ using filter chambers allowing exposure to ambient groundwater, but not to ambient microorganisms. SMX-exposed UAC bacterial communities displayed the greatest mortality and impairment (viable stain assays), the greatest change in sensitivity to SMX (dose-response assays), and the greatest change in community composition (Terminal Restriction Fragment Length Polymorphism; T-RFLP). The sul1 gene, encoding resistance to SMX at clinically relevant levels, and an element of Class I integrons, was not detected in any community. Changes in microbial community structure and SMX resistance over a short experimental period in previously nonexposed, slow-growing aquifer communities suggest concentrations of antibiotics 2-3 orders of magnitude less than those used in clinical applications may influence ecological function through changes in community composition, and could promote antibiotic resistance through selection of naturally resistant bacteria.

Transport of ARS-labeled hydroxyapatite nanoparticles in saturated granular media is influenced by surface charge variability even in the presence of humic acid.

Hydroxyapatite nanoparticle (nHAP) is increasingly being used to remediate soils and water polluted by metals and radionuclides. The transport and retention of Alizarin red S (ARS)-labeled nHAP were investigated in water-saturated granular media. Experiments were carried out over a range of ionic strength (I(c), 0-50mM NaCl) conditions in the presence of 10 mg L(-1) humic acid. The transport of ARS-nHAP was found to decrease with increasing suspension I(c) in part, because of enhanced aggregation and chemical heterogeneity. The retention profiles (RPs) of ARS-nHAP exhibited hyperexponential shapes (a decreasing rate of retention with increasing transport distance) for all test conditions, suggesting that some of the attachment was occurring under unfavorable conditions. Surface charge heterogeneities on the collector surfaces and especially within the ARS-nHAP population were contributing causes for the hyperexponential RPs. Consideration of the effect(s) of I(c) in the presence of HA is needed to improve the efficacy of nHAP for scavenging metals and actinides in real soils and groundwater environments.

Metabolism and distribution of benzo[a]pyrene-7,8-dione (B[a]P-7,8-dione) in human lung cells by liquid chromatography tandem mass spectrometry: detection of an adenine B[a]P-7,8-dione adduct.

Benzo[a]pyrene-7,8-dione (B[a]P-7,8-dione) is produced in human lung cells by the oxidation of (±)-B[a]P-7,8-trans-dihydrodiol, which is catalyzed by aldo-keto reductases (AKRs). However, information relevant to the cell-based metabolism of B[a]P-7,8-dione is lacking. We studied the metabolic fate of 2 µM 1,3-[(3)H(2)]-B[a]P-7,8-dione in human lung adenocarcinoma A549 cells, human bronchoalveolar H358 cells, and immortalized human bronchial epithelial HBEC-KT cells. In these three cell lines, 1,3-[(3)H(2)]-B[a]P-7,8-dione was rapidly consumed, and radioactivity was distributed between the organic and aqueous phase of ethyl acetate-extracted media, as well as in the cell lysate pellets. After acidification of the media, several metabolites of 1,3-[(3)H(2)]-B[a]P-7,8-dione were detected in the organic phase of the media by high performance liquid chromatography-ultraviolet-radioactivity monitoring (HPLC-UV-RAM). The structures of B[a]P-7,8-dione metabolites varied in the cell lines and were identified as B[a]P-7,8-dione conjugates with glutathione (GSH) and N-acetyl-l-cysteine (NAC), 8-O-monomethylated-catechol, catechol monosulfate, and monoglucuronide, and monohydroxylated-B[a]P-7,8-dione by liquid chromatography-tandem mass spectrometry (LC-MS/MS). We also obtained evidence for the first time for the formation of an adenine adduct of B[a]P-7,8-dione. Among these metabolites, the identity of the GSH-B[a]P-7,8-dione and the NAC-B[a]P-7,8-dione was further validated by comparison to authentic synthesized standards. The pathways of B[a]P-7,8-dione metabolism in the three human lung cell lines are formation of GSH and NAC conjugates, reduction to the catechol followed by phase II conjugation reactions leading to its detoxification, monohydroxylation, as well as formation of the adenine adduct.

Impact of fluorochrome stains used to study bacterial transport in shallow aquifers on motility and chemotaxis of Pseudomonas species.

One of the most common methods of tracking movement of bacteria in groundwater environments involves a priori fluorescent staining. A major concern in using these stains to label bacteria in subsurface injection-and-recovery studies is the effect they may have on the bacterium's transport properties. Previous studies investigated the impact of fluorophores on bacterial surface properties (e.g. zeta potential). However, no previous study has looked at the impact of fluorescent staining on swimming speed and chemotaxis. It was found that DAPI lowered the mean population swimming speed of Pseudomonas putida F1 by 46% and Pseudomonas stutzeri by 55%. DAPI also inhibited the chemotaxis in both strains. The swimming speeds of P. putida F1 and P. stutzeri were diminished slightly by CFDA/SE, but not to a statistically significant extent. CFDA/SE had no effect on chemotaxis of either strain to acetate. SYBR(®) Gold had no effect on swimming speed or the chemotactic response to acetate for either strain. This research indicates that although DAPI may not affect sorption to grain surfaces, it adversely affects other potentially important transport properties such as swimming and chemotaxis. Consequently, bacterial transport studies conducted using DAPI are biased to nonchemotactic conditions and do not appear to be suitable for monitoring the effect of chemotaxis on bacterial transport in shallow aquifers.

Humic acid facilitates the transport of ARS-labeled hydroxyapatite nanoparticles in iron oxyhydroxide-coated sand.

Hydroxyapatite nanoparticles (nHAP) have been widely used to remediate soil and wastewater contaminated with metals and radionuclides. However, our understanding of nHAP transport and fate is limited in natural environments that exhibit significant variability in solid and solution chemistry. The transport and retention kinetics of Alizarin red S (ARS)-labeled nHAP were investigated in water-saturated packed columns that encompassed a range of humic acid concentrations (HA, 0-10 mg L(-1)), fractional surface coverage of iron oxyhydroxide coatings on sand grains (λ, 0-0.75), and pH (6.0-10.5). HA was found to have a marked effect on the electrokinetic properties of ARS-nHAP, and on the transport and retention of ARS-nHAP in granular media. The transport of ARS-nHAP was found to increase with increasing HA concentration because of enhanced colloidal stability and the reduced aggregate size. When HA = 10 mg L(-1), greater ARS-nHAP attachment occurred with increasing λ because of increased electrostatic attraction between negatively charged nanoparticles and positively charged iron oxyhydroxides, although alkaline conditions (pH 8.0 and 10.5) reversed the surface charge of the iron oxyhydroxides and therefore decreased deposition. The retention profiles of ARS-nHAP exhibited a hyperexponential shape for all test conditions, suggesting some unfavorable attachment conditions. Retarded breakthrough curves occurred in sands with iron oxyhydroxide coatings because of time-dependent occupation of favorable deposition sites. Consideration of the above effects is necessary to improve remediation efficiency of nHAP for metals and actinides in soils and subsurface environments.

Effect of dissolved organic carbon on the transport and attachment behaviors of Cryptosporidium parvum oocysts and carboxylate-modified microspheres advected through temperate humic and tropical volcanic agricultural soil.

Transport of Cryptosporidium parvum oocysts and microspheres in two disparate (a clay- and Fe-rich, volcanic and a temperate, humic) agricultural soils were studied in the presence and absence of 100 mg L(-1) of sodium dodecyl benzene sulfonate (SDBS), and Suwannee River Humic Acid (SRHA) at pH 5.0-6.0. Transport of carboxylate-modified, 1.8 µm microspheres in soil columns was highly sensitive to the nature of the dissolved organic carbon (DOC), whereas oocysts transport was more affected by soil mineralogy. SDBS increased transport of microspheres from 48% to 87% through the tropical soil and from 43% to 93% in temperate soil. In contrast, SRHA reduced transport of microspheres from 48% to 28% in tropical soil and from 43% to 16% in temperate soil. SDBS also increased oocysts transport through the temperate soil 5-fold, whereas no oocyst transport was detected in tropical soil. SRHA had only a nominal effect in increasing oocysts transport in tropical soil, but caused a 6-fold increase in transport through the temperate soil. Amendments of only 4 mg L(-1) SRHA and SDBS decreased oocyst hydrophobicity from 66% to 20% and from 66% to 5%, respectively. However, SDBS increased microsphere hydrophobicity from 16% to 33%. Soil fines, which includes clays, and SRHA, both caused the oocysts zeta potential (ζ) to become more negative, but caused the highly hydrophilic microspheres to become less negatively charged. The disparate behaviors of the two colloids in the presence of an ionic surfactant and natural organic matter suggest that microspheres may not be suitable surrogates for oocysts in certain types of soils. These results indicate that whether or not DOC inhibits or promotes transport of oocysts and microspheres in agricultural soils and by how much, depends not only on the surface characteristics of the colloid, but the nature of the DOC and the soil mineralogy.

Synthesis of 13C4-labelled oxidized metabolites of the carcinogenic polycyclic aromatic hydrocarbon benzo[a]pyrene.

Polycyclic aromatic hydrocarbons (PAHs), such as benzo[a]pyrene (BaP), are ubiquitous environmental contaminants that are implicated in causing lung cancer. BaP is a component of tobacco smoke that is transformed enzymatically to active forms that interact with DNA. We reported previously development of a sensitive stable isotope dilution LC/MS method for analysis of BaP metabolites. We now report efficient syntheses of 13C4-BaP and the complete set of its 13C4-labelled oxidized metabolites needed as internal standards They include the metabolites not involved in carcinogenesis (Group A) and the metabolites implicated in initiation of cancer (Group B). The synthetic approach is novel, entailing use of Pd-catalyzed Suzuki, Sonogashira, and Hartwig cross-coupling reactions combined with PtCl2-catalyzed cyclization of acetylenic compounds. This synthetic method requires fewer steps, employs milder conditions, and product isolation is simpler than conventional methods of PAH synthesis. The syntheses of 13C4-BaP and 13C4-BaP-8-ol each require only four steps, and the 13C-atoms are all introduced in a single step. 13C4-BaP-8-ol serves as the synthetic precursor of all the oxidized metabolites of 13C-BaP implicated in initiation of cancer. The isotopic purities of the synthetic 13C4-BaP metabolites were estimated to be ≥99.9%.

Quantitation of benzo[a]pyrene metabolic profiles in human bronchoalveolar (H358) cells by stable isotope dilution liquid chromatography-atmospheric pressure chemical ionization mass spectrometry.

Polycyclic aromatic hydrocarbons (PAHs) are ubiquitous environmental pollutants and are carcinogenic in multiple organs and species. Benzo[a]pyrene (B[a]P) is a representative PAH and has been studied extensively for its carcinogenicity and toxicity. B[a]P itself is chemically inert and requires metabolic activation to exhibit its toxicity and carcinogenicity. Three major metabolic pathways have been well documented. The signature metabolites generated from the radical cation (peroxidase or monooxygenase mediated) pathway are B[a]P-1,6-dione and B[a]P-3,6-dione, the signature metabolite generated from the diol-epoxide (P450 mediated) pathway is B[a]P-r-7,t-8,t-9,c-10-tetrahydrotetrol (B[a]P-tetrol-1), and the signature metabolite generated from the o-quinone (aldo-keto reductase mediated) pathway is B[a]P-7,8-dione. The contributions of these different metabolic pathways to cancer initiation and the exploitation of this information for cancer prevention are still under debate. With the availability of a library of [(13)C(4)]-labeled B[a]P metabolite internal standards, we developed a sensitive stable isotope dilution atmospheric pressure chemical ionization tandem mass spectrometry method to address this issue by quantitating B[a]P metabolites from each metabolic pathway in human lung cells. This analytical method represents a 500-fold increased sensitivity compared with that of a method using HPLC-radiometric detection. The limit of quantitation (LOQ) was determined to be 6 fmol on column for 3-hydroxybenzo[a]pyrene (3-OH-B[a]P), the generally accepted biomarker for B[a]P exposure. This high level of sensitivity and robustness of the method was demonstrated in a study of B[a]P metabolic profiles in human bronchoalveolar H358 cells induced or uninduced with the AhR ligand, 2,3,7,8-tetrachlorodibenzodioxin (TCDD). All the signature metabolites were detected and successfully quantitated. Our results suggest that all three metabolic pathways contribute equally in the overall metabolism of B[a]P in H358 cells with or without TCDD induction. The sensitivity of the method should permit the identification of cell-type differences in B[a]P activation and detoxication and could also be used for biomonitoring human exposure to PAH.