Resilience as a Moderator of Extreme Stress Adaptation: Living Kidney Donor Analysis.

BACKGROUND: The aim of the study was to check if a situation of extreme and traumatizing stress, such as living kidney donation, would result in changes in the quality of the donor's life: whether a posttraumatic growth should occur, and if the donor would develop a strategy to handle strong and uncommon stress, known as resilience. METHODS: The study was conducted on 23 living kidney donors aged 25 to 63, who were examined 3 days before the donation and 6 months after. The study was conducted using the following tools: self-prepared questionnaires for donors before and after donations and validated questionnaires Cognitive Emotion Regulation (PRE), Posttraumatic Growth Inventory (PTGI-R), and Resilience Scale Inventory (SPP25). RESULTS: The results of the study proved that situations of extreme stress resulted in an increase of resilience. It was found that resilience was a moderator in the adaptation to extreme stress. A number of positive changes, known as posttraumatic growth, were noted. The examined patients focused on the adaptive strategies. CONCLUSION: It may be concluded that resilience is responsible for handling situations of extreme stress. Increased ability to mobilize, stronger focus on adaptive strategies, planning, and creating perspectives are observed. An observable increase of openness for new experiences, personal competencies to handle difficulties, tolerating negative emotions, and an optimistic approach to life may be noted.

A biomonitoring plan for assessing potential radionuclide exposure using Amchitka Island in the Aleutian chain of Alaska as a case study.

With the ending of the Cold War, the US and other nations were faced with a legacy of nuclear wastes. For some sites where hazardous nuclear wastes will remain in place, methods must be developed to protect human health and the environment. Biomonitoring is one method of assessing the status and trends of potential radionuclide exposure from nuclear waste sites, and of providing the public with early warning of any potential harmful exposure. Amchitka Island (51 degrees N lat, 179 degrees E long) was the site of three underground nuclear tests from 1965 to 1971. Following a substantive study of radionuclide levels in biota from the marine environment around Amchitka and a reference site, we developed a suite of bioindicators (with suggested isotopes) that can serve as a model for other sites contaminated with radionuclides. Although the species selection was site-specific, the methods can provide a framework for other sites. We selected bioindicators using five criteria: (1) occurrence at all three test shots (and reference site), (2) receptor groups (subsistence foods, commercial species, and food chain nodes), (3) species groups (plants, invertebrates, fish, and birds), (4) trophic levels, and (5) an accumulator of one or several radionuclides. Our major objective was to identify bioindicators that could serve for both human health and the ecosystem, and were abundant enough to collect adjacent to the three test sites and at the reference site. Site-specific information on both biota availability and isotope levels was essential in the final selection of bioindicators. Actinides bioaccumulated in algae and invertebrates, while radiocesium accumulated in higher trophic level birds and fish. Thus, unlike biomonitoring schemes developed for heavy metals or other contaminants, top-level predators are not sufficient to evaluate potential radionuclide exposure at Amchitka. The process described in this paper resulted in the selection of Fucus, Alaria fistulosa, blue mussel (Mytilus trossulus), dolly varden (Salvelinus malma), black rockfish (Sebastes melanops), Pacific cod (Gadus macrocephalus), Pacific halibut (Hippoglossus stenolepis), and glaucous-winged gull (Larus glaucescens) as bioindicators. This combination of species included mainly subsistence foods, commercial fish, and nodes on different food chains.

Leaching, geochemical modelling and field verification of a municipal solid waste and a predominantly non-degradable waste landfill.

In spite of the known heterogeneity, wastes destined for landfilling can be characterised for their leaching behaviour by the same protocols as soil, contaminated soil, sediments, sludge, compost, wood, waste and construction products. Characterisation leaching tests used in conjunction with chemical speciation modelling results in much more detailed insights into release controlling processes and factors than single step batch leaching tests like TCLP (USEPA) and EN12457 (EU Landfill Directive). Characterisation testing also can provide the potential for mechanistic impact assessments by making use of a chemical speciation fingerprint (CSF) derived from pH dependence leaching test results. This CSF then forms the basis for subsequent chemical equilibrium and reactive transport modelling to assess environmental impact in a landfill scenario under relevant exposure conditions, including conditions not readily evaluated through direct laboratory testing. This approach has been applied to municipal solid waste (MSW) and predominantly non-degradable waste (PNW) that is representative of a significant part of waste currently being landfilled. This work has shown that a multi-element modelling approach provides a useful description of the release from each of these matrices because relevant release controlling properties and parameters (mineral dissolution/precipitation, sorption on Fe and Al oxides, clay interaction, interaction with dissolved and particulate organic carbon and incorporation in solid solutions) are taken into consideration. Inclusion of dissolved and particulate organic matter in the model is important to properly describe release of the low concentration trace constituents observed in the leachate. The CSF allows the prediction of release under different redox and degradation conditions in the landfill by modifying the redox status and level of dissolved and particulate organic matter in the model runs. The CSF for MSW provides a useful starting point for comparing leachate data from other MSW landfills.

Probabilistic approach for estimating the release of contaminants under field management scenarios.

A probabilistic approach is presented for estimating the release of contaminants by leaching, when wastes are being considered for disposal in a class of landfills but the specific landfill disposal site is uncertain. A simple percolation and equilibrium-based release model is used in conjunction with laboratory testing results and observations of field leachate characteristics for municipal solid waste landfills, hazardous waste landfills and industrial co-disposal landfills. The approach is applied for assessing the efficacy of potential treatment processes for mercury contaminated soils. For each landfill scenario, historical values of leachate pH and annual leachate generation quantities were used to derive the probability distribution functions of the field pH and LS ratio that may be expected to contact the disposed material over an estimated time period of 100 years. For each potential treatment process, laboratory testing was used to establish the treated material's leaching characteristics as a function of pH LS ratio. This approach allowed determination of distribution frequencies and limit values for release estimates instead of single point estimates. The probability of the mass of a constituent of interest released exceeding a hypothetical threshold was examined for each treatment process and landfill system. Results of the probabilistic analysis allowed for integration of a range of data and provided a good basis for assessing the efficacy of the examined treatment processes over the three assumed disposal scenarios.

Life cycle assessment and residue leaching: the importance of parameter, scenario and leaching data selection.

Residues from industrial processes and waste management systems (WMSs) have been increasingly reutilised, leading to landfilling rate reductions and the optimisation of mineral resource utilisation in society. Life cycle assessment (LCA) is a holistic methodology allowing for the analysis of systems and products and can be applied to waste management systems to identify environmental benefits and critical aspects thereof. From an LCA perspective, residue utilisation provides benefits such as avoiding the production and depletion of primary materials, but it can lead to environmental burdens, due to the potential leaching of toxic substances. In waste LCA studies where residue utilisation is included, leaching has generally been neglected. In this study, municipal solid waste incineration bottom ash (MSWI BA) was used as a case study into three LCA scenarios having different system boundaries. The importance of data quality and parameter selection in the overall LCA results was evaluated, and an innovative method to assess metal transport into the environment was applied, in order to determine emissions to the soil and water compartments for use in an LCA. It was found that toxic impacts as a result of leaching were dominant in systems including only MSWI BA utilisation, while leaching appeared negligible in larger scenarios including the entire waste system. However, leaching could not be disregarded a priori, due to large uncertainties characterising other activities in the scenario (e.g. electricity production). Based on the analysis of relevant parameters relative to leaching, and on general results of the study, recommendations are provided regarding the use of leaching data in LCA studies.

Interactions of aniline with soil and groundwater at an industrial spill site.

The interactions of aniline with soil at an industrial spill site were investigated. Sorption of aniline to the soil was observed to occur through a two-step mechanism. The first step was an ion exchange process with the protonated amine serving as an organic cation. This step was influenced by solution pH and ionic composition. The second step was covalent bonding most likely with quinone moieties and oxidation with polymerization of aniline. The extent of covalent bonding was influenced by the presence of oxygen and redox potential. The majority of aniline that was bound to the soil did not readily desorb under a variety of abiotic conditions. However, aniline was released to a significant extent in the presence of denitrifying and methanogenic microbial activity. Aniline in aqueous solution was readily biodegradable under aerobic and denitrifying conditions. Soil-bound aniline was observed not to be biodegradable. This paper provides an overview of results.

The effects of auditory and visual linguistic distractors on target localization.

In this experiment, a Stroop-like paradigm was used to investigate the ability to attend to visuospatial cues while ignoring distracting stimuli in the auditory or visual modality. In Part 1, the authors investigated whether linguistic cue words (i.e., RIGHT, LEFT, DOWN, and UP) would induce endogenous shifts of attention to visual targets. In Part 2, a relevant distractor stimulus was introduced in a different modality from the endogenous cues to investigate effects of interference. Twenty-five right-handed students served as participants. Auditory and visual linguistic cues were effective in inducing shifts of visual attention when cues were presented alone. Furthermore, introducing a distractor stimulus decreased the efficacy of these cues differently depending on modality, suggesting that language processing and visuospatial attention may share neuronal resources. Implications for unimodal and supramodal mechanisms of selective attention and relevant neuronal networks are discussed.

Psychopathy and dual-task performance under focusing conditions.

Thirty psychopathic and 30 nonpsychopathic right-handed White male inmates (selected through R.D. Hare's, 1985b, Psychopathy Checklist) completed concurrent visual and auditory tasks under conditions focusing attention on the visual (i.e., primary) task. Performance indices tested 3 related hypotheses for cognitive deficits in psychopathic individuals: reduced attention to secondary tasks because of excess attention to immediate goals (interference), deficient shifts of attention, and reduced breadth of attention. The absence of differences in primary and secondary task accuracy contradicts the interference hypothesis. However, a trend toward deficits for psychopathic individuals responding with the right hand to primary task targets appearing after other targets, suggests poorer shifting of attention when left-hemisphere resources are engaged. Psychopathic individuals also overresponded to distractors following targets suggesting reduced attention to a peripheral dimension of two-dimensional stimuli.

Evaluating the construct validity of psychopathy in black and white male inmates: three preliminary studies.

Although Black inmates represent almost half the population of United States prisons and have been included in several studies of psychopathy, there appear to be no published studies to date addressing the validity of the psychopathy construct in Black inmates. Three studies were conducted to assess the validity of the construct in Black male inmates using Hare's Psychopathy Checklist (PCL). In Study 1, we examined the internal structure of the PCL and the relation of checklist scores to several constructs relevant to psychopathy. We observed differences between Blacks and Whites in the distribution of psychopathy scores, in the relation of psychopathy to measures of impulsivity, and in the congruence of the underlying factor structure of the PCL. In Study 2, Black psychopaths were found to manifest a pattern of passive avoidance deficits similar but not identical to that reported for White psychopaths in Newman and Kosson's study. Study 3 demonstrated that psychopaths of both races receive more criminal charges in a wider variety of offense categories than do nonpsychopaths. The psychopathy construct appears tentatively applicable to Blacks, although its components may be somewhat different than for Whites.

Delay of gratification in psychopathic and nonpsychopathic offenders.

Delay of gratification is a prototypical measure of self-control that merits systematic investigation in psychopaths. White male prisoners were provided with repeated opportunities to select an immediate response with uncertain reward or a delayed response with a higher rate of reward under one of three incentive conditions. Psychopaths' performance depended on their level of trait anxiety and incentive condition: Whereas low-anxious psychopaths were relatively unwilling to delay when omission of expected rewards also incurred monetary punishments, they displayed relatively superior performance when the task involved rewards only. Findings complement those for passive avoidance learning in psychopaths and suggest that inhibitory self-control in low-anxious psychopaths is somewhat impaired under conditions involving a combination of monetary rewards and punishments.

Altering a dominant response: performance of psychopaths and low-socialization college students on a cued reaction time task.

The passive avoidance learning deficits of disinhibited Ss have been attributed to their difficulty inhibiting dominant responses. To date, evidence for this hypothesis has been derived from complex tasks. In two experiments, a cued reaction time task requiring no learning or memory was used to evaluate the degree to which groups of disinhibited Ss inhibit simple dominant responses. Disinhibited groups were incarcerated psychopaths identified with Hare's (1985) Psychopathy Checklist and undergraduate males who scored low on the Socialization Scale. Both disinhibited groups committed more errors than controls on trials containing misleading cues, but in both samples, findings were limited to trials in which Ss expected to make right-hand responses. Although alternative interpretations are possible, these data are consistent with the proposal that disinhibited individuals are less likely to inhibit well-established dominant responses.

Socialization and attentional deficits under focusing and divided attention conditions.

We conducted two studies to test and refine the hypothesis that, when undersocialized individuals focus on events of immediate interest, they allocate too large a proportion of their processing resources to those events and have little attention available for processing other important events. College students who completed the Socialization (So) scale (Gough, 1960) performed visual and auditory tasks simultaneously under conditions favoring the visual task, an equal division of processing resources between the tasks, or both. In both studies, low-So Ss performed relatively poorly on the auditory task under focusing conditions but displayed no primary task advantage and no significant performance deficits under divided attention conditions. These data support the utility of theories relating antisocial behavior to individual differences in allocation of attention. Low-So Ss' unresponsiveness to secondary events is not a simple function of the reallocation of resources to the primary task or a speed-accuracy trade-off. Moreover, under certain conditions, this deficit may disappear, given substantial practice.

Reaction to punishment, reflectivity, and passive avoidance learning in extraverts.

Passive avoidance learning occupies a central role in accounts of disinhibited behavior, ranging from psychopaths' persistent criminality (Hare 1970) to extraverts' gregariousness (Gray, 1972). To explore the mechanism underlying passive avoidance deficits, we assessed the relation of extraversion, neuroticism, and response latency after punishment to passive avoidance learning by using two successive go/no go discrimination tasks. The tasks were designed to examine two aspects of subjects' reactions to punishment: response speed on trials immediately following punishment (Experiment 1) and time to terminate punishment feedback between successive trials (i.e., reflectivity; Experiment 2). Consistent with previous findings, the results of Experiment 1 showed that extraverts commit more passive avoidance errors than introverts do (Newman, Widom, & Nathan, 1985) and fail to pause following punished errors (Nichols & Newman, 1986). In Experiment 2, only neurotic extraverts displayed this pattern of performance differences. In both experiments, longer pausing following punishment predicted better learning from punishment for both introverts and extraverts. These results suggest that, in the presence of salient cues for reward, extraverts' characteristic reaction to punishment interferes with processing punished errors and may contribute to their more general propensity for impulsive, nonreflective action.

Pore structure of soot deposits from several combustion sources.

Soot was harvested from five combustion sources: a dodecane flame, marine and bus diesel engines, a wood stove, and an oil furnace. The soots ranged from 20% to 90% carbon by weight and molar C/H ratios from 1 to 7, the latter suggesting a highly condensed aromatic structure. Total surface areas (by nitrogen adsorption using the Brunauer Emmett Teller, BET method) ranged from 1 to 85 m2 g(-1). Comparison of the surface area and meso-pore (pores 2-50 nm) surface area predicted by density functional theory (DFT) suggested that the soot was highly porous. Total meso-pore volume and surface area ranged from 0.004-0.08 cm3 g(-1) and from 0.33-6.9 m2 g(-1) respectively, accounting for up 33% of the BET surface area. The micro-pore volume (pores <2 nm) calculated from CO2 adsorption data (by DFT) ranged from 0.0009 to 0.013 cm3 g(-1) and micro-pore surface area was 3.1-41 m2 g(-1), accounting for 10-20% of the total intra-particle (meso-plus micro-pores) pore volume and 70-90% of the total intra-particle surface area. Higher pore volume and surface area values were computed using the Dubinin Radushkevich plot technique; ranging from 0.004-0.04 cm3 g(-1) to 11-102 m2 g(-1) for micro-pore volume and surface area, respectively. Comparison of the C/H ratio and the micro-pore structure showed a strong correlation, suggesting a relationship between the condensation of the skeletal structure and micro-porosity of the soot. These data contradict literature reports that soot particles are non-porous and are consistent with recent literature reports that soil organic matter has large micro-pore surface areas.

Psychopathy and ethnicity: structural, item, and test generalizability of the Psychopathy Checklist--Revised (PCL-R) in Caucasian and African American Participants.

The Psychopathy Checklist--Revised (PCL-R) is an important measure in both applied and research settings. Evidence for its validity is mostly derived from male Caucasian participants. PCL-R ratings of 359 Caucasian and 356 African American participants were compared using confirmatory factor analysis (CFA) and item response theory (IRT) analyses. Previous research has indicated that 13 items of the PCL-R can be described by a 3-factor hierarchical model. This model was replicated in this sample. No cross-group difference in factor structure could be found using CFA; the structure of psychopathy is the same in both groups. IRT methods indicated significant but small differences in the performance of 5 of the 20 PCL-R items. No significant differential test functioning was found, indicating that the item differences canceled each other out. It is concluded that the PCL-R can be used, in an unbiased way, with African American participants.

The effect of storage in an inert atmosphere on the release of inorganic constituents during intermittent wetting of a cement-based material.

Monolithic waste materials (e.g. Portland cement treated wastes) in many field scenarios do not remain continuously saturated, but experience intermittent wetting interspersed with periods of storage in an unsaturated environment. During storage, the matrix may loss moisture to the environment, promoting precipitation or redistribution of species. In addition, the matrix may react with the surrounding atmosphere through carbonation or oxidation. Upon subsequent leaching, changes in the chemical and physical composition incurred over the storage interval can influence the release of inorganic species. Current assessment approaches, which use continuous leaching data to project release over some assessment interval, do not allow for changes in leachability resulting from intermittent wetting and storage. Thus, this study evaluates the effect of storage intervals in an inert atmosphere on subsequent release of inorganic species from a synthetic Portland cement matrix. Tank leaching in deionized water was interspersed with storage at three relative humidity (RH) levels (nominally 0, 50 and 100% RH) in a 100% nitrogen atmosphere. Leaching data from the three intermittent wetting cases were compared to continuous leaching for the release of structural species (Ca, OH), highly soluble species (Na, K, Cl) and pH-dependent species (As, Cd, Pb). The RH of storage environment, which acted as a boundary condition for the drying process, influenced the precipitation of species within dried pores and relaxation of pH and concentration gradients within water-filled regions. Gradient relaxation resulted from continued mass transport within saturated pores over the storage interval and was most evident when storage was conducted at 98% RH. However, when storage RH promoted drying of the matrix, the effect of gradient relaxation was balanced by precipitation. When release was normalized to total leaching time, relaxation of concentration gradients of highly soluble species resulted in greater cumulative release for the intermittently wetted cases than in the case of continuous leaching. The release of pH-dependent constituents was controlled by relaxation of the pH gradient and species solubility as a function of local pore water pH. Application of a current assessment protocol to estimate intermittent wetting release resulted in either over or underestimation of actual cumulative release, depending on the nature of the constituent of interest. These results imply that long-term constituent release from Portland cement-based waste forms should not be made by simple correction of saturated release assessments because alterations to the matrix leachability induced by the storage environment need to be considered.

Environmental assessment of waste matrices contaminated with arsenic.

The use of equilibrium-based and mass transfer-based leaching tests has been proposed to provide an integrated assessment of leaching processes from solid wastes. The objectives of the research presented here are to (i) validate this assessment approach for contaminated soils and cement-based matrices, (ii) evaluate the use of diffusion and coupled dissolution-diffusion models for estimating constituent release, and (iii) evaluate model parameterization using results from batch equilibrium leaching tests and physical characterization. The test matrices consisted of (i) a soil contaminated with arsenic from a pesticide production facility, (ii) the same soil subsequently treated by a Portland cement stabilization/solidification (S/S) process, and (iii) a synthetic cement-based matrix spiked with arsenic(III) oxide. Results indicated that a good assessment of contaminant release from contaminated soils and cement-based S/S treated wastes can be obtained by the integrated use of equilibrium-based and mass transfer-based leaching tests in conjunction with the appropriate release model. During the time scale of laboratory testing, the release of arsenic from the contaminated soil matrix was governed by diffusion and the solubility of arsenic in the pore solution while the release of arsenic from the cement-based matrices was mainly controlled by solubilization at the interface between the matrix and the bulk leaching solution. In addition, results indicated that (i) estimation of the activity coefficient within the matrix pore water is necessary for accurate prediction of constituent release rates and (ii) inaccurate representation of the factors controlling release during laboratory testing can result in significant errors in release estimates.

Changes in constituent equilibrium leaching and pore water characteristics of a Portland cement mortar as a result of carbonation.

Two equilibrium-based characterization protocols were applied to ground samples of a cement-based material containing metal oxide powders in both noncarbonated and carbonated states. The effects of carbonation were shown through comparison of (i) material buffering capacity, (ii) constituent equilibrium as a function of leachate pH, and (iii) constituent solubility and release as a function of liquid-to-solid (LS) ratio. As expected, the material alkalinity was significantly neutralized during carbonation. In addition, carbonation of the cement material led to the formation of calcium carbonate and a corresponding increase in arsenic release across the entire pH range. The solubility as a function of pH for lead and copper was lower in the alkaline pH range (pH>9) for carbonated samples compared with the parent material. When solubility and release as a function of LS ratio was compared, carbonation was observed to decrease calcium solubility, sodium and potassium release, and ionic strength. In response to carbonate solid formation, chloride and sulfate release as a function of LS ratio was observed to increase. Trends in constituent concentration as a function of LS ratio were extrapolated to estimate pore water composition at a 0.06 mL/g LS ratio. Significant differences were observed upon comparison of estimated pore water composition to leachate concentrations extracted at LS ratio of 5 mL/g. These differences show that practical laboratory extractions cannot be assumed directly representative of pore water concentrations.

Characteristics, treatment and utilization of residues from municipal waste incineration.

Beneficial utilization of residues from municipal solid waste incineration is an important objective for integrated waste management in many jurisdictions. When residues are to be used as an aggregate substitute in construction applications, the release of constituents of concern to soils and water through leaching is an important environmental consideration. In this paper, residue characteristics that control constituent leaching and testing approaches for evaluating leaching are discussed. Quality control and potential improvement in case of beneficial application are addressed.

Multi-regime transport model for leaching behavior of heterogeneous porous materials.

Utilization of secondary materials in civil engineering applications (e.g. as substitutes for natural aggregates or binder constituents) requires assessment of the physical and environment properties of the product. Environmental assessment often necessitates evaluation of the potential for constituent release through leaching. Currently most leaching models used to estimate long-term field performance assume that the species of concern is uniformly dispersed in a homogeneous porous material. However, waste materials are often comprised of distinct components such as coarse or fine aggregates in a cement concrete or waste encapsulated in a stabilized matrix. The specific objectives of the research presented here were to (1) develop a one-dimensional, multi-regime transport model (i.e. MRT model) to describe the release of species from heterogeneous porous materials and, (2) evaluate simple limit cases using the model for species when release is not dependent on pH. Two different idealized model systems were considered: (1) a porous material contaminated with the species of interest and containing inert aggregates and, (2) a porous material containing the contaminant of interest only in the aggregates. The effect of three factors on constituent release were examined: (1) volume fraction of material occupied by the aggregates compared to a homogeneous porous material, (2) aggregate size and, (3) differences in mass transfer rates between the binder and the aggregates. Simulation results confirmed that assuming homogeneous materials to evaluate the release of contaminants from porous waste materials may result in erroneous long-term field performance assessment.