Impact of phosphate dosing on the microbial ecology of drinking water distribution systems: Fieldwork studies in chlorinated networks.

Phosphate is routinely dosed to ensure regulatory compliance for lead in drinking water distribution systems. Little is known about the impact of the phosphate dose on the microbial ecology in these systems and in particular the endemic biofilms. Disturbance of the biofilms and embedded material in distribution can cause regulatory failures for turbidity and metals. To investigate the impact of phosphate on developing biofilms, pipe wall material from four independent pipe sections was mobilised and collected using two twin-flushing operations a year apart in a chlorinated UK network pre- and post-phosphate dosing. Intensive monitoring was undertaken, including turbidity and water physico-chemistry, traditional microbial culture-based indicators, and microbial community structure via sequencing the 16S rRNA gene for bacteria and the ITS2 gene for fungi. Whole metagenome sequencing was used to study shifts in functional characteristics following the addition of phosphate. As an operational consequence, turbidity responses from the phosphate-enriched water were increased, particularly from cast iron pipes. Differences in the taxonomic composition of both bacteria and fungi were also observed, emphasising a community shift towards microorganisms able to use or metabolise phosphate. Phosphate increased the relative abundance of bacteria such as Pseudomonas, Paenibacillus, Massilia, Acinetobacter and the fungi Cadophora, Rhizophagus and Eupenicillium. Whole metagenome sequencing showed with phosphate a favouring of sequences related to Gram-negative bacterium type cell wall function, virions and thylakoids, but a reduction in the number of sequences associated to vitamin binding, methanogenesis and toxin biosynthesis. With current faecal indicator tests only providing risk detection in bulk water samples, this work improves understanding of how network changes effect microbial ecology and highlights the potential for new approaches to inform future monitoring or control strategies to protect drinking water quality.

Microbial diversity, ecological networks and functional traits associated to materials used in drinking water distribution systems.

Drinking water distribution systems host complex microbial communities as biofilms that interact continuously with delivered water. Understanding the diversity, behavioural and functional characteristics will be a requisite for developing future monitoring strategies and protection against water-borne health risks. To improve understanding, this study investigates mobilisation and accumulation behaviour, microbial community structure and functional variations of biofilms developing on different pipe materials from within an operational network. Samples were collected from four pipes during a repeated flushing operation three months after an initial visit that used hydraulic forces to mobilise regenerating biofilms yet without impacting the upstream network. To minimise confounding factors, test sections were chosen with comparable daily hydraulic regimes, physical dimensions, and all connected straight of a common trunk main and within close proximity, hence similar water chemistry, pressure and age. Taxonomical results showed differences in colonising communities between pipe materials, with several genera, including the bacteria Pseudomonas and the fungi Cladosporium, present in every sample. Diverse bacterial communities dominated compared to more homogeneous fungal, or mycobiome, community distribution. The analysis of bacterial/fungal networks based on relative abundance of operational taxonomic units (OTUs) indicated microbial communities from cast iron pipes were more stable than communities from the non-ferrous pipe materials. Novel analysis of functional traits between all samples were found to be mainly associated to mobile genetic elements that play roles in determining links between cells, including phages, prophages, transposable elements, and plasmids. The use of functional traits can be considered for development in future surveillance methods, capable of delivering network condition information beyond that of limited conventional faecal indicator tests, that will help protect water quality and public health.

Understanding and managing discolouration risk in trunk mains.

There is currently no accepted concept or approach for understanding and controlling discolouration risk associated with trunk mains. This paper assesses the applicability of cohesive layer theories to manage discolouration and a steady state empirical modelling tool that describes the process of particulate material accumulation. Results are presented from independent field experiments across the UK and internationally that evidence hydraulically induced mobilisation, or effectively cleaning, once imposed system shear stress exceeds normal conditions. Model calibration to measured data validates the cohesive layer concept with transferability in empirically derived parameters demonstrating a viable operational planning tool. The experiments highlight the accumulation of material layers as a continuous and ubiquitous process, such that fully clean pipes can never exist and helping explain how discolouration risk changes over time. A major practical implication of the novel understanding demonstrated in this paper is that discolouration risk in trunk mains can be simply managed by pro-active strategies that regularly vary the hydraulic conditions. This avoids the need for disruptive and expensive out of service invasive interventions yet offers operators a cost-effective long-term strategy to safeguard water quality.

Dynamics of Biofilm Regrowth in Drinking Water Distribution Systems.

UNLABELLED: The majority of biomass within water distribution systems is in the form of attached biofilm. This is known to be central to drinking water quality degradation following treatment, yet little understanding of the dynamics of these highly heterogeneous communities exists. This paper presents original information on such dynamics, with findings demonstrating patterns of material accumulation, seasonality, and influential factors. Rigorous flushing operations repeated over a 1-year period on an operational chlorinated system in the United Kingdom are presented here. Intensive monitoring and sampling were undertaken, including time-series turbidity and detailed microbial analysis using 16S rRNA Illumina MiSeq sequencing. The results show that bacterial dynamics were influenced by differences in the supplied water and by the material remaining attached to the pipe wall following flushing. Turbidity, metals, and phosphate were the main factors correlated with the distribution of bacteria in the samples. Coupled with the lack of inhibition of biofilm development due to residual chlorine, this suggests that limiting inorganic nutrients, rather than organic carbon, might be a viable component in treatment strategies to manage biofilms. The research also showed that repeat flushing exerted beneficial selective pressure, giving another reason for flushing being a viable advantageous biofilm management option. This work advances our understanding of microbiological processes in drinking water distribution systems and helps inform strategies to optimize asset performance. IMPORTANCE: This research provides novel information regarding the dynamics of biofilm formation in real drinking water distribution systems made of different materials. This new knowledge on microbiological process in water supply systems can be used to optimize the performance of the distribution network and to guarantee safe and good-quality drinking water to consumers.

The bacteriological composition of biomass recovered by flushing an operational drinking water distribution system.

This study investigates the influence of pipe characteristics on the bacteriological composition of material mobilised from a drinking water distribution system (DWDS) and the impact of biofilm removal on water quality. Hydrants in a single UK Distribution Management Area (DMA) with both polyethylene and cast iron pipe sections were subjected to incremental increases in flow to mobilise material from the pipe walls. Turbidity was monitored during these operations and water samples were collected for physico-chemical and bacteriological analysis. DNA was extracted from the material mobilised into the bulk water before and during flushing. Bacterial tag-encoded 454 pyrosequencing was then used to characterize the bacterial communities present in this material. Turbidity values were high in the samples from cast iron pipes. Iron, aluminium, manganese and phosphate concentrations were found to correlate to observed turbidity. The bacterial community composition of the material mobilised from the pipes was significantly different between plastic and cast iron pipe sections (p < 0.5). High relative abundances of Alphaproteobacteria (23.3%), Clostridia (10.3%) and Actinobacteria (10.3%) were detected in the material removed from plastic pipes. Sequences related to Alphaproteobacteria (22.8%), Bacilli (16.6%), and Gammaproteobacteria (1.4%) were predominant in the samples obtained from cast iron pipes. The highest species richness and diversity were found in the samples from material mobilised from plastic pipes. Spirochaeta spp., Methylobacterium spp. Clostridium spp. and Desulfobacterium spp., were the most represented genera in the material obtained prior to and during the flushing of the plastic pipes. In cast iron pipes a high relative abundance of bacteria able to utilise different iron and manganese compounds were found such as Lysinibacillus spp., Geobacillus spp. and Magnetobacterium spp.

Opening farm gates: community as educator.

This paper presents the experience of five undergraduate Bachelor of Nursing students who undertook a clinical practice placement in a rural community. This, our first engagement with nursing, was a profound learning experience. We did not expect the intense contributions the rural community as a whole would make to our understandings of rural health care in general, and rural nursing in particular. Initially, we felt like outsiders to the rural community as well as the profession of nursing. The interwoven nature of community relationships combined with our acute sense of being highly visible in the township led to us developing a sense of vulnerability. We believed we needed to portray a professional image during all social interactions with the community and this compounded our insecurities during the clinical placement. Before long, we found the rural population embracing and very supportive of our placement. However, we found ourselves questioning whether we would return to a rural community to work as nurses on the basis of our lack of privacy during this time.

Efferent projections of the ectostriatum in the pigeon (Columba livia).

The ectostriatum is a major visual component of the avian telencephalon. The core region of the ectostriatum (Ec) receives visual input from the optic tectum through thalamic nuclei. In the present study, the efferent projections of the ectostriatum were investigated by using the anterograde tracers Phaseolus vulgaris leucoagglutinin and biotinylated dextran amine. Projection patterns resulting from these tracers were confirmed by the retrograde tracer cholera toxin subunit B. When anterograde tracers were injected in Ec, primary projections were seen traveling dorsolaterally to the belt region of the ectostriatum (Ep) and the neostriatal area immediately surrounding Ep (Ep2). Neurons in Ep sent projections primarily to the overlying Ep2. The efferents of Ep2 traveled dorsolaterally to terminate in three telencephalic regions, from anterior to posterior: (1) neostriatum frontale, pars lateralis (NFL), (2) area temporo-parieto-occipitalis (TPO), and (3) neostriatum intermedium, pars lateralis (NIL). A part of the archistriatum intermedium and the lateral part of the neostriatum caudale also received somewhat minor projections. In addition, some neurons in Ec were also the source of direct, but minor, projections to the NFL, TPO, NIL, and archistriatum intermedium. The topographical relationship among the primary (Ec), secondary (Ep and Ep2), and tertiary (NFL, TPO, NIL) areas indicate that the neural populations for visual processing are organized along the rostral-caudal axis. Thus, the anterior Ec sent efferents to the anterior Ep, which in turn sent projections to anterior Ep2. Neurons in the anterior Ep2 sent projections to NFL and the anterior TPO. Similarly, the intermediate and posterior Ec sent projections to corresponding parts of Ep, whose efferents projected to intermediate and posterior Ep2, respectively. The intermediate Ep2 gave rise to major projections to TPO, whereas posterior Ep2 neurons sent efferents primarily to NIL. The organization of this neural circuit is compared with those of other sensory circuits in the avian telencephalon, as well as the laminar arrangement of the mammalian isocortex.

MMPI profiles of opiate addicts: predicting response to treatment.

Although many studies document the use of the MMPI to classify opiate users, the predictive validity of the resulting subgroups is rarely reported. In this study, we used cluster analysis to identify MMPI profile types that predicted differential response to methadone maintenance treatment. Participants (N = 151) completed MMPIs shortly after entry into treatment. Cluster analysis of MMPI scores produced four distinct subgroups that differed significantly in severity of psychosocial problems measured at admission and on the mean number of drug-free urine specimens submitted during the 24-week study period. Cluster 1 participants evidenced low levels of psychological disturbance, improved their urinalysis results over time, and submitted the most posttest drug-free urine specimens. Cluster 2 was the only other group that improved significantly over time, even though these patients were the most psychologically disturbed. The results suggest the relation between psychological problems and outcome may be more complex than is commonly assumed.

Impact of comorbid personality disorders and personality disorder symptoms on outcomes of behavioral treatment for cocaine dependence.

Studies have revealed a significant adverse impact of comorbid personality disorders on treatment tenure and outcome in a variety of psychiatric and substance abuse populations. We investigated whether this negative relationship also exists among 137 urban, poor, cocaine abusers in behaviorally oriented treatment. Axis II diagnoses were generated categorically using the SCID-II as well as dimensionally using numbers of SCID-II symptoms within diagnostic categories. Contrary to expectations, there were no significant differences between subjects with and without various categorical personality disorders on any outcome measures. Categorical Axis II diagnoses were also minimally correlated with drug use severity, depression, and anxiety at intake, indicating that these were not potential coveriates of outcome. However, dimensional analyses of personality symptoms generated from the SCID-II accounted for substantial proportions of variance in treatment outcomes. Implications of these data for Axis II assessment and drug treatment planning are discussed.

Structured interview versus self-report test vantages for the assessment of personality pathology in cocaine dependence.

The study compared structured interview (SCID-II) and self-report test (MCMI-II) vantages for the detection and characterization of personality pathology among 144 urban, poor, cocaine-addicted individuals seeking outpatient treatment. Diagnostic agreement was inadequate for most disorders, and the instruments at best shared only modest common variance. Positive predictive power was poor for all MCMI-II scales, though negative predictive power was good to excellent. This lends support for the use of the MCMI-II as a screening measure to rule out Axis II disorders; however, confirmation of positive diagnoses will require follow-up interview assessment. Future development of self-report personality inventories for substance abusers should focus on controlling for the acute dysphoric effects of drug use and related dysfunction, expanding attention to Cluster B content domains, and incorporating more objective criteria for assessing paranoia and "odd/eccentric" traits.

Reinforcing operants other than abstinence in drug abuse treatment: an effective alternative for reducing drug use.

This study examines the effectiveness of using vouchers to reinforce either the provision of urine samples testing negative for illicit drugs (UA group) or the completion of objective, individually defined, treatment-plan-related tasks (TP group). A third group was assigned to the clinic's standard treatment (STD group). Participants were randomly assigned to groups after a 6-week baseline-stabilization period. Urine specimens were collected thrice weekly throughout the study. In the UA condition, participants earned $5 (U.S. dollars) in vouchers for each drug-free urine submitted. In the TP condition, participants earned up to $15 in vouchers per week for demonstrating completion of treatment plan tasks assigned by their counselors. Contingencies were in effect for 12 weeks, after which all participants received the clinic's standard treatment. Urinalysis results indicate that the TP intervention was significantly more effective in reducing illicit drug use than either the UA or STD interventions. These effects were maintained with a trend toward continuing improvement for the TP groups even after contingencies were discontinued.

Assessment of coercive and noncoercive pressures to enter drug abuse treatment.

This paper reports preliminary data derived from a standardized interview scoring procedure for detecting and characterizing coercive and noncoercive pressures to enter substance abuse treatment. Coercive and noncoercive pressures stemming from multiple psychosocial domains are operationalized through recourse to established behavioral principles. Inter-rater reliability for the scoring procedure was exceptional over numerous rater trials. Substantive analyses indicate that, among clients in outpatient cocaine treatment, 'coercion' is operative in multiple psychosocial domains, and that subjects perceive legal pressures as exerting substantially less influence over their decisions to enter treatment than informal psychosocial pressures. Implications for drug treatment planning, legal and ethical issues, and directions for future research are proposed.

Telencephalic afferents to the caudolateral neostriatum of the pigeon.

The pigeon caudolateral neostriatum (NCL) shares a dopaminergic innervation with mammalian frontal cortical areas and is implicated in the regulation of avian cognitive behavior. Retrograde tracing methods were used to identify forebrain projections to NCL and to suggest a possible role of this area in mediating spatial behavior. NCL receives telencephalic projections from the hyperstriatum accessorium, cells along the border of hyperstriatum dorsale and hyperstriatum ventrale, anterolateral hyperstriatum adjacent to the vallecula, confined cell groups within the anterior neostriatum, and subdivisions of the archistriatum. In addition, labeling of a small number of large cells near the fasciculus prosencephali lateralis was observed at the level of the anterior commissure. In accordance with previous studies, projections of subtelencephalic areas were revealed to originate from the thalamic posterior dorsolateral nucleus and nucleus subrotundus, as well as from the tegmental nucleus pedunculopontinus and locus coeruleus. Forebrain connections of NCL show that somatosensory, visual, and olfactory information can combine in this division of the neostriatum. NCL is therefore suited to participate in a neural circuit that regulates spatial behavior. Moreover, the present study reveals that NCL is reached by a limbic projection from the nucleus taeniae. This projection also suggests similarity between NCL and mammalian frontal cortical areas.

Decline in self-reported dysphoria after treatment entry in inner-city cocaine addicts.

This study examined self-reported dysphoria in 82 consecutive admissions to intensive outpatient treatment for cocaine abuse on whom data for the Beck scales for depression, anxiety, and hopelessness were available for intake and 4 subsequent weeks with no more than 1 missing data point. Mean scores on the Beck Depression Inventory (BDI) and the Beck Anxiety Inventory (BAI) decreased significantly between intake and Week 1, with no further significant changes from Weeks 1-4. Similar drops in the rate of clinically significant BDI and BAI scores also were observed. Scores on the Beck Hopelessness Scale (BHS) showed no significant changes. By Week 4, rates of clinically significant depression, anxiety, and hopelessness were similar (17%, 13%, and 16%, respectively). These findings suggest that assessing depression and anxiety using the BDI and BAI in this population should be postponed for at least 1 week after intake and that intake levels of self-reported mood may be inappropriate baseline measures for evaluating treatment effects.

Situations occasioning cocaine use and cocaine abstinence strategies.

We interviewed 265 cocaine-experienced methadone patients about situations that occasioned their cocaine use and strategies they used to avoid cocaine use. Subjects identified an average of 15 situations that occasioned cocaine use. The three most frequently identified were having the drug present (86% of subjects), being offered the drug (85%) and having money available (83%). Subjects reporting fewer situations also reported longer periods of lifetime abstinence (p < 0.01). A principal components analysis extracted 10 groups of situations that were most frequently identified in combination. Subjects identified a median of seven strategies for avoiding cocaine use; however, there was large inter-subject variability. This variance was not accounted for by demographic variables, employment status or treatment experience. The three strategies identified most frequently were avoiding people and places (81%), thinking about what they could lose (76%) and leaving the situation (66%). The total number and type (reactive vs. proactive) of strategies identified by subjects had no relationship to cocaine abstinence, although four specific strategies (thinking about what could be lost, leaving the situation, moving to a new area and using a different drug) were positively correlated with cocaine abstinence. We discuss implications of these results for clinical practice.

Comparison of MMPI-2 and MMPI clinical scales and high-point scores among methadone maintenance clients.

Methadone client volunteers completed the Minnesota Multiphasic Personality Inventory (MMPI; Hathaway & McKinley, 1967) and MMPI-2 (Butcher, Dahlstrom, Graham, Tellegen, & Kaemmer, 1989) on consecutive days. MMPI-2 T-scores were lower by a mean of 4.7 on the clinical scales; when 5 points were added to MMPI-2 T-scores the mean difference was 2.3. Rank order of subjects on scale T-scores was not significantly different between the two instruments. High-point similarity for clinically elevated profile pairs ranged from 61% to 92%, depending upon definition of similarity.

Problem-solving types among high-risk IDUs. Potential treatment implications.

This research investigated whether high-risk injection drug users (IDUs) manifest distinct types, or profiles, of interpersonal cognitive problem-solving (ICPS) abilities. Four measures of ICPS, the Means-Ends Problem-Solving procedure (MEPS), Optional Thinking Test (OTT), Awareness of Consequences Test (ACT), and Causal Thinking Test (CTT), were administered to 140 IDUs who volunteered for NIDA Demonstration Projects in Newark and Jersey City, NJ, to study high-risk behaviors in drug users and their sexual partners. At time of initial contact, none of the subjects was currently enrolled in a treatment program. Hierarchical and nonhierachical cluster analyses were used with the MEPS, OTT, ACT, and CTT scores, and five IDU problem-solving types were identified. These types represented below-average, causal, generational, consequential, and above-average problem-solving skills. A rational conceptualization of potential treatment implications for each of these types of IDU problem solvers is discussed.

Major psychotherapeutic modalities for heroin addiction: a brief overview.

This article provides a brief overview of recent literature on major psychotherapeutic modalities for heroin addiction. These modalities include psychotherapy, behavior therapy, cognitive-behavioral therapy, family therapy, social skills training approaches, and therapeutic communities. It highlights studies with stronger research design and methodology, many of which are theory-based, and discusses what appear to be the "active ingredients" in these modalities which contribute to successful treatment outcome. It concludes that there is an increasing convergence of theory and research in the field of heroin addiction treatment, making the designing of treatment programs based on empirical knowledge more feasible.