Compositional Constructor Interpretation over Coalgebraic Models for the π—Calculus

AbstractThe π-calculus and its variants are one of the most important subjects in the field of process algebra. Researchers in the coalgebra community have taken account of that by developing a family of related final coalgebra models for the π-calculus. None of these models has, however, been given with interpretations of the π-calculus constructors as operations on semantic domains. The present paper introduces such interpretations over final coalgebra models for the π-calculus. These models do not exactly belong to the realm of the already existing work. Rather, we emphasise the distinction between a a ground model and a full model: The ground model is fully abstract with respect to a form of π-calculus ground bisimulation; the full model is built on top of the ground model and is fully abstract with respect to the congruence derived from that ground bisimulation. Also, every semantic object is a 3-tuple with a direct representation of its transformation under renamings. A straightforward adaption of Rutten and Turi's mixed terms technique then yields compositional interpretations of most constructors of the π-calculus on the ground level. These interpretations can be lifted to the full level, again yielding compositionality.Because input prefixing does not preserve ground bisimilarity, this π-calculus constructor cannot be interpreted compositionally strictly on the ground level. It is therefore given an independent interpretation over the full model

Web Services as a New Approach to Distributing and Coordinating Semantics-Based Veri cation Toolkits

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ACUTE DESTRUCTION BY HUMORAL ANTIBODY OF RAT SKIN GRAFTED TO MICE : THE ROLE OF COMPLEMENT AND POLYMORPHONUCLEAR LEUKOCYTES

A study has been made of the roles played by complement and polymorphonuclear leukocytes (PMN) in the acute destruction of xenografts of rat skin that follows injection of their hosts with antisera specifically reactive with graft antigens. The rat skin was grafted onto mice whose immune responses were suppressed by removal of the thymus and a brief course of treatment with rabbit antimouse lymphocyte serum. At about 2 wk after grafting the mice were injected intravenously or intraperitoneally with mouse antirat serum (MARS). This time interval was chosen because it avoided the complications that might be associated with either the process of healing in or with incipient rejection. Signs of graft damage were evident as early as 10 min after the injection of MARS, and in most animals so injected the grafts were completely destroyed within 24–48 h. The role of complement (C) in this acute destructive process is indicated by the results of three lines of experimentation. (a) Non-C-fixing antibodies or antibody fragments failed to cause damage to the grafts. Indeed, both chicken antirat serum and F(ab')2 fragments from rabbit antirat serum completely protected the grafts against the effects of MARS that was administered 24 h later. (b) When mice were depleted of hemolytic C by treatment with cobra venom factor or heat-aggregated gamma globulin, the damage caused by MARS was greatly reduced or completely inhibited. (c) In mice with a genetically determined absence of C5 much greater quantities of MARS were required to cause graft damage; the tempo of the destructive process was consistently slower; and a greater number of grafts recovered from the initial inflammatory process than was the case for animals with an intact complement system. The participation of PMN in serum-mediated destruction of grafts was initially suggested by the results of microscope examination of fixed tissues. The essential role of these cells in the process is indicated by the failure of MARS to cause tissue damage in mice whose circulating PMN have been reduced to very low levels by treatment with nitrogen mustard or more specifically with an anti-PMN serum. The absence of tissue damage when circulating PMN are reduced but C levels are normal suggests that C-mediated cytolysis is unimportant in graft destruction and that the role of C lies in its ability to generate chemotactic factors. The latter may then attract the PMN that provide mediators of tissue damage

Schützet die Vögel! : die nützlichen und schädlichen Vögel Deutschlands und Europa's / von A. C. Eduard Baldamus

von A. C. Eduard Baldamu

Configural frequency analysis as a method of determining patients' preferred decision-making roles in dialysis

<p>Abstract</p> <p>Background</p> <p>Numerous studies examined factors in promoting a patient preference for active participation in treatment decision making with only modest success. The purpose of this study was to identify types of patients wishing to participate in treatment decisions as well as those wishing to play a completely active or passive role based on a Germany-wide survey of dialysis patients; using a prediction typal analysis method that defines types as configurations of categories belonging to different attributes and takes particularly higher order interactions between variables into account.</p> <p>Methods</p> <p>After randomly splitting the original patient sample into two halves, an exploratory prediction configural frequency analysis (CFA) was performed on one-half of the sample (n = 1969) and the identified types were considered as hypotheses for an inferential prediction CFA for the second half (n = 1914). 144 possible prediction types were tested by using five predictor variables and control preferences as criterion. An α-adjustment (0.05) for multiple testing was performed by the Holm procedure.</p> <p>Results</p> <p>21 possible prediction types were identified as hypotheses in the exploratory prediction CFA; four patient types were confirmed in the confirmatory prediction CFA: patients preferring a passive role show low information seeking preference, above average trust in their physician, perceive their physician's participatory decision-making (PDM)-style positive, have a lower educational level, and are 56-75 years old (Type 1; <it>p </it>< 0.001) or > 76 years old (Type 2; <it>p </it>< 0.001). Patients preferring an active role show high information seeking preference, a higher educational level, and are < 55 years old. They have either below average trust, perceive the PDM-style negative (Type 3; <it>p </it>< 0.001) or above average trust and perceive the PDM-style positive (Type 4; <it>p </it>< 0.001).</p> <p>Conclusions</p> <p>The method prediction configural frequency analysis was newly introduced to the research field of patient participation and could demonstrate how a particular control preference role is determined by an association of five variables.</p

An exercise on transition systems

Labelled transition systems admit different but equivalent characterizations either as relational structures or coalgebras for the powerset functor, each of them with their own merits. Notions of simulation and bisimulation, for example, are expressed in the pointfree relational calculus in a very concise and precise way. On the other hand, the coalgebraic perspective regards processes as inhabitants of a final universe and allows for an intuitive definition of the semantics of process’ combinators. This paper is an exercise on such a dual characterisation. In particular, it discusses how a notion of weak bisimilarity can be lifted from the relational to the coalgebraic level, to become an effective reasoning tool on coinductively defined process algebras.(undefined

A criterion for separating process calculi

We introduce a new criterion, replacement freeness, to discern the relative expressiveness of process calculi. Intuitively, a calculus is strongly replacement free if replacing, within an enclosing context, a process that cannot perform any visible action by an arbitrary process never inhibits the capability of the resulting process to perform a visible action. We prove that there exists no compositional and interaction sensitive encoding of a not strongly replacement free calculus into any strongly replacement free one. We then define a weaker version of replacement freeness, by only considering replacement of closed processes, and prove that, if we additionally require the encoding to preserve name independence, it is not even possible to encode a non replacement free calculus into a weakly replacement free one. As a consequence of our encodability results, we get that many calculi equipped with priority are not replacement free and hence are not encodable into mainstream calculi like CCS and pi-calculus, that instead are strongly replacement free. We also prove that variants of pi-calculus with match among names, pattern matching or polyadic synchronization are only weakly replacement free, hence they are separated both from process calculi with priority and from mainstream calculi.Comment: In Proceedings EXPRESS'10, arXiv:1011.601

Preferences of patients undergoing hemodialysis - results from a questionnaire-based study with 4,518 patients

Janssen IM, Gerhardus A, von Gersdorff G, et al. Preferences of patients undergoing hemodialysis - results from a questionnaire-based study with 4,518 patients. Patient Preference and Adherence. 2015;2015(9):847-855.Background: Chronic kidney disease is an increasing health problem worldwide and in its final stage (stage V) can only be treated by renal replacement therapy, mostly hemodialysis. Hemodialysis has a major influence on the everyday life of patients and many patients report dissatisfaction with treatment. Little is known about which aspects of treatment are considered important by hemodialysis patients. The objective of this study was to rate the relative importance of different outcomes for hemodialysis patients and to analyze whether the relative importance differed among subgroups of patients. Patients and methods: Within the framework of a yearly questionnaire which is distributed among patients receiving hemodialysis by the largest hemodialysis provider in Germany, we assessed the relative importance of 23 outcomes as rated on a discrete visual analog scale. Descriptive statistics were used to rank the outcomes. Subgroup analyses were performed using Mann–Whitney U or Kruskal–Wallis tests. Results: Questionnaires of 4,518 hemodialysis patients were included in the analysis. The three most important outcomes were safety of treatment, health-related quality of life, and satisfaction with care. Further important outcomes were hospital stays, accompanying symptoms, hemodialysis duration, and the improvement or preservation of a good emotional state. Age, profession, and education had the strongest influence on relevant differences of preferences for outcomes; no relevant influence of sex or comorbidity was observed. Conclusion: Outcomes concerning the delivery or provision of care and aspects influencing quality of life are rated by patients to be at least as important as clinical outcomes. Many of the outcomes judged to be important by the patients are not regularly considered in research, evaluation studies, or quality programs