Goal-conflict detection based on temporal satisfiability checking

Goal-oriented requirements engineering approaches propose capturing how a system should behave through the speci ca- tion of high-level goals, from which requirements can then be systematically derived. Goals may however admit subtle situations that make them diverge, i.e., not be satis able as a whole under speci c circumstances feasible within the domain, called boundary conditions . While previous work al- lows one to identify boundary conditions for con icting goals written in LTL, it does so through a pattern-based approach, that supports a limited set of patterns, and only produces pre-determined formulations of boundary conditions. We present a novel automated approach to compute bound- ary conditions for general classes of con icting goals expressed in LTL, using a tableaux-based LTL satis ability procedure. A tableau for an LTL formula is a nite representation of all its satisfying models, which we process to produce boundary conditions that violate the formula, indicating divergence situations. We show that our technique can automatically produce boundary conditions that are more general than those obtainable through existing previous pattern-based approaches, and can also generate boundary conditions for goals that are not captured by these patterns

TRPA1 channel activation induces cholecystokinin release via extracellular calcium

AbstractTRPA1 channels are non-selective cation channels activated by plant derived pungent products including allyl isothiocyanate (AITC) from mustard. Therefore, possible intestinal secretory functions of these channels were investigated. We detected TRPA1 mRNA in mouse and human duodenal mucosa and in intestinal mouse neuroendocrine STC-1 cells. Stimulation of STC-1 cells with AITC increased intracellular calcium ([Ca2+]i) and significantly stimulated cholecystokinin secretion by 6.7-fold. AITC induced cholecystokinin release was completely blocked by TRPA1 antagonist ruthenium red and depletion of extracellular calcium and reduced by 36% by nimodipine and nifedipine. This suggests that spices in our daily food might stimulate digestive functions

As a Matter of Factions: The Budgetary Implications of Shifting Factional Control in Japan’s LDP

For 38 years, the Liberal Democratic Party (LDP) maintained single-party control over the Japanese government. This lack of partisan turnover in government has frustrated attempts to explain Japanese government policy changes using political variables. In this paper, we look for intraparty changes that may have led to changes in Japanese budgetary policy. Using a simple model of agenda-setting, we hypothesize that changes in which intraparty factions “control” the LDP affect the party’s decisions over spending priorities systematically. This runs contrary to the received wisdom in the voluminous literature on LDP factions, which asserts that factions, whatever their raison d’être, do not exhibit different policy preferences. We find that strong correlations do exist between which factions comprise the agenda-setting party “mainstream” and how the government allocates spending across pork-barrel and public goods items

The Detectability of Pair-Production Supernovae at z < 6

Nonrotating, zero metallicity stars with initial masses 140 < M < 260 solar masses are expected to end their lives as pair-production supernovae (PPSNe), in which an electron-positron pair-production instability triggers explosive nuclear burning. Interest in such stars has been rekindled by recent theoretical studies that suggest primordial molecular clouds preferentially form stars with these masses. Since metal enrichment is a local process, the resulting PPSNe could occur over a broad range of redshifts, in pockets of metal-free gas. Using the implicit hydrodynamics code KEPLER, we have calculated a set of PPSN light curves that addresses the theoretical uncertainties and allows us to assess observational strategies for finding these objects at intermediate redshifts. The peak luminosities of typical PPSNe are only slightly greater than those of Type Ia, but they remain bright much longer (~ 1 year) and have hydrogen lines. Ongoing supernova searches may soon be able to limit the contribution of these very massive stars to < 1% of the total star formation rate density out to z=2 which already provides useful constraints for theoretical models. The planned Joint Dark Energy Mission satellite will be able to extend these limits out to z=6.Comment: 12 pages, 6 figures, ApJ in press; slightly revised version, a few typos correcte

Propositional update operators based on formula/literal dependence

International audienceWe present and study a general family of belief update operators in a propositional setting. Its operators are based on formula/literal dependence, which is more fine-grained than the notion of formula/variable dependence that was proposed in the literature: formula/variable dependence is a particular case of formula/literal dependence. Our update operators are defined according to the "forget-then-conjoin" scheme: updating a belief base by an input formula consists in first forgetting in the base every literal on which the input formula has a negative influence, and then conjoining the resulting base with the input formula. The operators of our family differ by the underlying notion of formula/literal dependence, which may be defined syntactically or semantically, and which may or may not exploit further information like known persistent literals and pre-set dependencies. We argue that this allows to handle the frame problem and the ramification problem in a more appropriate way. We evaluate the update operators of our family w.r.t. two important dimensions: the logical dimension, by checking the status of the Katsuno-Mendelzon postulates for update, and the computational dimension, by identifying the complexity of a number of decision problems (including model checking, consistency and inference), both in the general case and in some restricted cases, as well as by studying compactability issues. It follows that several operators of our family are interesting alternatives to previous belief update operators

Automating Agential Reasoning: Proof-Calculi and Syntactic Decidability for STIT Logics

This work provides proof-search algorithms and automated counter-model extraction for a class of STIT logics. With this, we answer an open problem concerning syntactic decision procedures and cut-free calculi for STIT logics. A new class of cut-free complete labelled sequent calculi G3LdmL^m_n, for multi-agent STIT with at most n-many choices, is introduced. We refine the calculi G3LdmL^m_n through the use of propagation rules and demonstrate the admissibility of their structural rules, resulting in auxiliary calculi Ldm^m_nL. In the single-agent case, we show that the refined calculi Ldm^m_nL derive theorems within a restricted class of (forestlike) sequents, allowing us to provide proof-search algorithms that decide single-agent STIT logics. We prove that the proof-search algorithms are correct and terminate

Colloid-stabilized emulsions: behaviour as the interfacial tension is reduced

We present confocal microscopy studies of novel particle-stabilized emulsions. The novelty arises because the immiscible fluids have an accessible upper critical solution temperature. The emulsions have been created by beginning with particles dispersed in the single-fluid phase. On cooling, regions of the minority phase nucleate. While coarsening these nuclei become coated with particles due to the associated reduction in interfacial energy. The resulting emulsion is arrested, and the particle-coated interfaces have intriguing properties. Having made use of the binary-fluid phase diagram to create the emulsion we then make use of it to study the properties of the interfaces. As the emulsion is re-heated toward the single-fluid phase the interfacial tension falls and the volume of the dispersed phase drops. Crumpling, fracture or coalescence can follow. The results show that the elasticity of the interfaces has a controlling influence over the emulsion behaviour.Comment: Submitted for the proceedings of the 6th Liquid Matter Conference, held in Utrecht (NL) in July 200

Detailing the effects of polypharmacy in psychiatry: longitudinal study of 320 patients hospitalized for depression or schizophrenia

Current treatment standards in psychiatry are oriented towards polypharmacy, that is, patients receive combinations of several antidepressants, antipsychotics, mood stabilizers, anxiolytics, hypnotics, antihistamines, and anticholinergics, along with other somatic treatments. In tandem with the beneficial effects of psychopharmacological drug treatment, patients experience significant adverse reactions which appear to have become more frequent and more severe with the rise of ubiquitous polypharmacy. In this study, we aimed to assess today's acute inpatient treatment of depressive and schizophrenic disorders with focus on therapeutic strategies, medications, adverse side effects, time course of recovery, and efficacy of treatments. Of particular interest was the weighing of the benefits and drawbacks of polypharmacy regimens. We recruited a total of 320 patients hospitalized at three residential mental health treatment centers with a diagnosis of either schizophrenic (ICD-10: "F2x.x"; n = 94; "F2 patients") or depressive disorders (ICD-10: "F3x.x"; n = 226; "F3 patients"). The study protocol included (1) assessment of previous history by means of the SADS Syndrome Check List SSCL-16 (lifetime version); (2) repeated measurements over 5 weeks assessing the time course of improvement by the Hamilton Depression Scale HAM-D and the Positive and Negative Syndrome Scale PANSS, along with medications and adverse side effects through the Medication and Side Effects Inventory MEDIS; and (3) the collection of blood samples from which DNA and serum were extracted. Polypharmacy was by far the most common treatment regimen (85%) in this study. On average, patients received 4.50 ± 2.68 medications, consisting of 3.30 ± 1.84 psychotropic drugs, plus 0.79 ± 1.13 medications that alleviate adverse side effects, plus 0.41 ± 0.89 other somatic medications. The treating psychiatrists appeared to be the main determining factor in this context, while «previous history» and «severity at baseline» played a minor role, if at all. Adverse drug reactions were found to be an inherent component of polypharmacy and tended to have a 2-3 times higher incidence compared to monotherapy. Severe adverse reactions could not be attributed to a particular drug or drug combination. Rather, the empirical data suggested that severe side effects can be triggered by virtually all combinations of drugs, provided patients have a respective vulnerability. In terms of efficacy, there were no advantages of polypharmacy over monotherapy. The results of this study underlined the fact that polypharmacy regimens are not equally suited for every patient. Specifically, such regimens appeared to have a negative impact on treatment outcome and to obfuscate the "natural" time course of recovery through a multitude of interfering factors. Evidence clearly speaks against starting just every therapeutic intervention in psychiatry with a combination of psychopharmaceuticals. We think that it is time for psychiatry to reconsider its treatment strategies, which are far too one-sidedly fixated on psychopharmacology and pay far too little attention to alternative approaches, especially in mild cases where psychotherapy without concurrent medication should still be an option. Also, regular exercises and sports can definitely be an effective therapeutic means in a considerable number of cases. General practitioners (GPs) are particularly in demand here