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The underlying problems associated with the development of the biotic ligand model (BLM) for prediction of silver toxicity, and its associated physiological and toxicological endpoints, were investigated at a mechanistic, physiological level in juvenile rainbow trout. An equilibrium level of silver accumulation at the gills is achieved over time during flow-through exposures. The pattern of peak and decline in accumulation during static exposures is due to a decrease in the bioavailability of Ag⁺ because of complexation by organic carbon produced by the fish, a consequence of the use of a static exposure system. The decrease in bioavailability leads to a decline in apical silver uptake and together with constant basolateral silver export, a peak and decline in gill silver accumulation. Inhibition of carbonic anhydrase (CA) by silver is responsible for the early decline in active Na⁺ uptake at the gills during flow-through silver exposure, while Na⁺K⁺-ATPase inhibition is associated with the later decline in uptake. CA activity is inhibited early during silver exposure when Na⁺ and Cl⁻ uptake are decreasing but Na⁺ K⁺ ATPase activity is not inhibited until later. The implication of the data that the rate limiting step in the movement of Na⁺ and Cl⁻ across the gill epithelium is the movement across the apical membrane, as well as the identical time course and degree of Cl⁻ and Na⁺ uptake inhibition provide additional evidence for a role of CA inhibition in the early decline in Na⁺ uptake. A relationship exists between short-term gill silver accumulation and inhibition of Na⁺ uptake. There is also a relationship between silver accumulation on the gills after 3 h, as well as after 24 h, and 96 h mortality. Together, the results of this thesis indicate that short-term gill silver accumulation is an appropriate endpoint for the prediction of acute silver toxicity in freshwater fish, lending support to the current toxicological version of the silver BLM. These results also indicate that the predictive capabilities of the current physiological BLM may be improved by using Na⁺ uptake inhibition rather than Na⁺K⁺-ATPase inhibition as an endpoint to predict acute silver toxicity. / Thesis / Master of Science (MS)

Lors de crises en entreprise, certaines ressources aux caractéristiques particulières émergent pour aider autrui, dans la souffrance. Nous appelons ces ressources : les toxic handlers. Le rôle de cette recherche est de comprendre ce que font les « toxic handlers », pourquoi ils aident autrui dans la souffrance, comment ils le font, comment les organisations peuvent les aider. Les « toxic handlers » sauvent les entreprises par acte de compassion mais payent malheureusement un lourd prix pour cela. Nous avons tenté de répondre au processus de création de la résilience de compassion en entreprise. De quelle manière des individus qui ne laisse rien paraître de particulier au regard de leur entreprise se trouve subitement pris de compassion pour leurs collègues. Nous nous posons la question de ce qui se passe chez le toxic handler, est-il « un porteur de compassion ou de souffrance » ? Comment cette compassion/souffrance va naître chez le « toxic handler » ? Pourquoi les « employés en souffrance » ne parviennent pas à affronter les « émotions toxiques » ? Comment se crée la relation qui va s’effectuer entre le « toxic handler » et « l’employé en souffrance » ? Les toxic handlers sont intermédiaires entre les « toxic boss » et « les employés en souffrance ». Mais les toxic handlers ne peuvent agir seulement et seulement si, il y a crise en entreprise (crise interne) et que le toxic handler soit aussi en crise (nous parlons de double crise). Nous avons réalisé un modèle d’analyse du processus de résilience de compassion et nous l’avons appliqué sur plusieurs entreprises de grandes tailles, subissant des crises. Nos travaux ouvrent un champ de recherches et amènent de nombreuses perspectives au regard de la problématique du processus de résilience de compassion en entreprise. / When a crisis occurs within a company, certain resources with particular characteristics emerge, helping those who suffer. We call these resources: “toxic handlers.”The role of this research is to understand what it is that “toxic handlers” do, why they help others in difficult. How do they do this? What can organizations do to help them? “Toxic handlers” rescue companies through an act compassion, but unfortunately they pay a heavy price for this. We have attempted to answer certain questions surrounding the creation process of compassionate resilience within companies. How do individuals, who don’t appear to be suffering in the eyes of their companies, find themselves full of compassion for their close colleagues? We’re asking ourselves what happens to a toxic handler. Is he or she a “carrier of compassion or of suffering”? How does this compassion or suffering come about with regard to the “toxic handler”? Why can’t employees who suffer manage to front up to toxic emotions? How is the relation between the “toxic handler” and the “employees in pain” created? Toxic handlers act as intermediaries between “toxic boss” and “employees in pain.” The actions of “toxic handlers” are nonexistent within a company unless there is an internal crisis and only if the “toxic handler” is also facing a crisis (what we call a double crisis). We have created an analysis model for compassionate resilience and have applied it to several large companies suffering from a crisis. Our work opens a field of research and brings together numerous perspectives concerning the problematic of compassionate resilience within a company.

Thesis (M. Phil.)--University of Hong Kong, 1998. / Includes bibliographical references (leaves 85-107).

Lors de crises en entreprise, certaines ressources aux caractéristiques particulières émergent pour aider autrui, dans la souffrance. Nous appelons ces ressources : les toxic handlers. Le rôle de cette recherche est de comprendre ce que font les « toxic handlers », pourquoi ils aident autrui dans la souffrance, comment ils le font, comment les organisations peuvent les aider. Les « toxic handlers » sauvent les entreprises par acte de compassion mais payent malheureusement un lourd prix pour cela. Nous avons tenté de répondre au processus de création de la résilience de compassion en entreprise. De quelle manière des individus qui ne laisse rien paraître de particulier au regard de leur entreprise se trouve subitement pris de compassion pour leurs collègues. Nous nous posons la question de ce qui se passe chez le toxic handler, est-il « un porteur de compassion ou de souffrance » ? Comment cette compassion/souffrance va naître chez le « toxic handler » ? Pourquoi les « employés en souffrance » ne parviennent pas à affronter les « émotions toxiques » ? Comment se crée la relation qui va s’effectuer entre le « toxic handler » et « l’employé en souffrance » ? Les toxic handlers sont intermédiaires entre les « toxic boss » et « les employés en souffrance ». Mais les toxic handlers ne peuvent agir seulement et seulement si, il y a crise en entreprise (crise interne) et que le toxic handler soit aussi en crise (nous parlons de double crise). Nous avons réalisé un modèle d’analyse du processus de résilience de compassion et nous l’avons appliqué sur plusieurs entreprises de grandes tailles, subissant des crises. Nos travaux ouvrent un champ de recherches et amènent de nombreuses perspectives au regard de la problématique du processus de résilience de compassion en entreprise. / When a crisis occurs within a company, certain resources with particular characteristics emerge, helping those who suffer. We call these resources: “toxic handlers.”The role of this research is to understand what it is that “toxic handlers” do, why they help others in difficult. How do they do this? What can organizations do to help them? “Toxic handlers” rescue companies through an act compassion, but unfortunately they pay a heavy price for this. We have attempted to answer certain questions surrounding the creation process of compassionate resilience within companies. How do individuals, who don’t appear to be suffering in the eyes of their companies, find themselves full of compassion for their close colleagues? We’re asking ourselves what happens to a toxic handler. Is he or she a “carrier of compassion or of suffering”? How does this compassion or suffering come about with regard to the “toxic handler”? Why can’t employees who suffer manage to front up to toxic emotions? How is the relation between the “toxic handler” and the “employees in pain” created? Toxic handlers act as intermediaries between “toxic boss” and “employees in pain.” The actions of “toxic handlers” are nonexistent within a company unless there is an internal crisis and only if the “toxic handler” is also facing a crisis (what we call a double crisis). We have created an analysis model for compassionate resilience and have applied it to several large companies suffering from a crisis. Our work opens a field of research and brings together numerous perspectives concerning the problematic of compassionate resilience within a company.

The report discusses the destruction of toxic and non-toxic solids, liquids and gases through lasers. In order to completely understand the project first chapters describes the basics about laser and plasma separately, from definition to types, components and categories. Differences between laser and microwave system are covered in this chapter as well. Besides lasers there are different technologies that are currently being used to destroy toxic and non-toxic materials. These technologies were studied and comparison tables are made in order to discern between different destruction technologies. For the destruction of toxic and non-toxic materials through lasers two mathematical models have been developed, molecular dissociation model and plasma exploitation model, and later the experimental work was carried out on one of the toxic material. Mathematical modeling and experimental work is in accordance with each other as discussed in results and discussion. Mathematical model shows that all the materials discussed in the report can be destroyed by lasers but in order to carry further experiments on all other toxic and non-toxic materials, a proposal is made for the laser reactor using CAD model (Solid Edge) and drawing software (AutoCAD). Tables and mathematical calculations have been placed in appendix at the end of the report.

The use of cleaning products can lead to indoor concentrations of toxic air contaminants above regulatory levels. Studies show that the use of cleaning products is related to adverse respiratory health effects in adults ranging from irritation to asthma. Yet exposure to these chemicals is poorly understood. This thesis summarizes the current state of knowledge of inhalation exposure to toxic chemicals in consumer cleaning products. A new two-compartment model that treats personal air space as distinct from bulk room air is presented. The model accounts for air exchange between the two compartments and fresh air, dynamic source characteristics (i.e., the time-varying liquid concentrations and emission rates of pollutants within a mixture), the characteristics of chemical use (e.g., how frequently a cleaning chemical is applied to a new area), and reactive chemistry with ozone. The model’s applicability is restricted by limited data available for parameterization. Key components that are missing include composition data for consumer cleaning products and activity patterns. Extensive effort went into calculating the air exchange rate between the two zones. Twelve computational fluid dynamic simulations and two model scenarios were completed. The predicted concentration in the inner-zone (Cin) was divided by the room concentration predicted by the traditional well-mixed model (Cwm). Concentration ratios (Cin/Cwm) ranged from 1.1 to 700. In terms of real cleaning events, results indicate that the beginning (where the only emission source is near the person) of events taking place in large indoor environments with high air exchange rates are the situations for which well-mixed models are most likely to fail in predicting actual exposures. / text

The ecological composition of plaintiff entities may vary in size and sociographics in toxic tort litigation. The amount of awards and the justifications for those awards in the various plaintiff situations are unknown. Consolidation which is procedurally distinct from class consolidation procedurally distinct from class action is an alternative litigation strategy for mass torts. While it is well-grounded in English common law, jury decision making in consolidated actions has not been extensively examined by social scientific, legal, or communication researchers. In light of the limited research in this area, awards and decision justifications were gathered from two populations of surrogate jurors. Subjects were asked to decide on the amount of money to award a single plaintiff or a small aggregate, small group, large aggregate or large group of plaintiffs in a written summary of a hypothetical toxic substance case. In addition, respondents were asked to explain the reason(s) for their award decisions. The average award in each situation was in the mid-point area of a range from zero to one million dollars. The amount implies that on average respondents were inclined to give all plaintiff entities approximately $500,000. The justifications for the awards were organized into the following nine categories determined by the application of Toulmin's model of argument: (1)~Company Attribution - CA; (2)~Employee Attribution - EA; (3)~Attribution to Both Employee and Company - BA; (4)~Evaluation Pro-Plaintiff - EPP; (5)~Evaluation Pro-Defendant - EPD; (6)~Sufficient Compensation - SC; (7)~Company Attribution/Sufficient Compensation - CASC; (8)~Employee Attribution/Sufficient Compensation - EASC; and (9)~Both Attribution/Sufficient Compensation - BASC. The underlying warrants(s) in the responses served as the label for each category. The classifications revealed a categorical advantage for the plaintiff(s). Respondents provided justifications beyond strict attributions of responsibility to the parties involved. Need for compensation and a positive regard for plaintiffs, for example, were issues which emerged in the justifications Attribution of responsibility to the employee was a consistent basis for monetary decisions for subjects who decided not to award any compensation. Respondents who were maximum award givers, however, deviated from attributions in the small aggregate, small group, and large aggregate situations.

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