Value withdrawal explanations: a theoretical tool for programming environments

Constraint logic programming combines declarativity and efficiency thanks to constraint solvers implemented for specific domains. Value withdrawal explanations have been efficiently used in several constraints programming environments but there does not exist any formalization of them. This paper is an attempt to fill this lack. Furthermore, we hope that this theoretical tool could help to validate some programming environments. A value withdrawal explanation is a tree describing the withdrawal of a value during a domain reduction by local consistency notions and labeling. Domain reduction is formalized by a search tree using two kinds of operators: operators for local consistency notions and operators for labeling. These operators are defined by sets of rules. Proof trees are built with respect to these rules. For each removed value, there exists such a proof tree which is the withdrawal explanation of this value.Comment: 14 pages; Alexandre Tessier, editor; WLPE 2002, http://xxx.lanl.gov/abs/cs.SE/020705

Towards declarative diagnosis of constraint programs over finite domains

The paper proposes a theoretical approach of the debugging of constraint programs based on a notion of explanation tree. The proposed approach is an attempt to adapt algorithmic debugging to constraint programming. In this theoretical framework for domain reduction, explanations are proof trees explaining value removals. These proof trees are defined by inductive definitions which express the removals of values as consequences of other value removals. Explanations may be considered as the essence of constraint programming. They are a declarative view of the computation trace. The diagnosis consists in locating an error in an explanation rooted by a symptom.Comment: In M. Ronsse, K. De Bosschere (eds), proceedings of the Fifth International Workshop on Automated Debugging (AADEBUG 2003), September 2003, Ghent. cs.SE/030902

Corporate social responsibility in a general equilibrium stock market model: Solving the financial performance puzzle

We analyze corporate social responsibility (CSR) in a general equilibrium stock market model with uncertainty in production. Production generates non-market costs and consumers take this into account when they construct their portfolio. We deduce empirically testable hypotheses and analyze how CSR affects various financial performance indicators. We show that our model offers an excellent explanation of the seemingly contradictory findings in the existing empirical literature. We stress that our findings are not a result of assumptions on the operational level of the firm. We conclude that there is a clear and direct association between CSR and different measures of corporate financial performance.

Model-Based Software Debugging

The complexity and size of software systems have rapidly increased in recent years, with software engineers facing ever-growing challenges in building and maintaining such systems. In particular, testing and debugging, that is, finding, isolating, and eliminating defects in software systems still constitute a major challenge in practiceMinisterio de Ciencia y Tecnología TIN2015-63502-C3-2-RFundacao para a Ciencia e a Tecnologia (FCT) UID/EEA/50014/2013European Regional Development Fund (ERDF) POCI-01-0145-FEDER-006961 (COMPETE 2020

Experience and Challenges from Clinical Trials with Malaria Vaccines in Africa.

Malaria vaccines are considered amongst the most important modalities for potential elimination of malaria disease and transmission. Research and development in this field has been an area of intense effort by many groups over the last few decades. Despite this, there is currently no licensed malaria vaccine. Researchers, clinical trialists and vaccine developers have been working on many approached to make malaria vaccine available.African research institutions have developed and demonstrated a great capacity to undertake clinical trials in accordance to the International Conference on Harmonization-Good Clinical Practice (ICH-GCP) standards in the last decade; particularly in the field of malaria vaccines and anti-malarial drugs. This capacity is a result of networking among African scientists in collaboration with other partners; this has traversed both clinical trials and malaria control programmes as part of the Global Malaria Action Plan (GMAP). GMAP outlined and support global strategies toward the elimination and eradication of malaria in many areas, translating in reduction in public health burden, especially for African children. In the sub-Saharan region the capacity to undertake more clinical trials remains small in comparison to the actual need.However, sustainability of the already developed capacity is essential and crucial for the evaluation of different interventions and diagnostic tools/strategies for other diseases like TB, HIV, neglected tropical diseases and non-communicable diseases. There is urgent need for innovative mechanisms for the sustainability and expansion of the capacity in clinical trials in sub-Saharan Africa as the catalyst for health improvement and maintained

Reflex responses from the main pulmonary artery and bifurcation in anaesthetised dogs

This study was undertaken to determine the reflex cardiovascular and respiratory responses to discrete stimulation of pulmonary arterial baroreceptors using a preparation in which secondary modulation of responses from other reflexes was prevented. Dogs were anaesthetised with [alpha]-chloralose, artificially ventilated, the chests widely opened and a cardiopulmonary bypass established. The main pulmonary arterial trunk, bifurcation and extrapulmonary arteries as far as the first lobar arteries on each side were vascularly isolated and perfused through the left pulmonary artery and drained via the right artery through a Starling resistance which controlled pulmonary arterial pressure. Pressures distending systemic baroreceptors and reflexogenic regions in the heart were controlled. Reflex vascular responses were assessed from changes in perfusion pressures to a vascularly isolated hind limb and to the remainder of the subdiaphragmatic systemic circulation, both of which were perfused at constant flows. Respiratory responses were assessed from recordings of efferent phrenic nerve activity. Increases in pulmonary arterial pressure consistently evoked increases in both perfusion pressures and in phrenic nerve activity. Both vascular and respiratory responses were obtained when pulmonary arterial pressure was increased to above about 30 mmHg. Responses increased at higher levels of pulmonary arterial pressures. In 13 dogs increases in pulmonary arterial pressure to 45 mmHg increased systemic perfusion pressure by 24 ± 7 mmHg (mean ± S.E.M.) from 162 ± 11 mmHg. Setting carotid sinus pressure at different levels did not influence the vascular response to changes in pulmonary arterial pressure. The presence of a negative intrathoracic pressure of -20 mmHg resulted in larger vascular responses being obtained at lower levels of pulmonary arterial pressure. This indicates that the reflex may be more effective in the intact closed-chest animal. These results demonstrate that stimulation of pulmonary arterial baroreceptors evokes a pressor reflex and augments respiratory drive. This reflex is likely to be elicited in circumstances where pulmonary arterial pressure increases and the negative excursions of intrathoracic pressure become greater. They are likely, therefore, to be involved in the cardio-respiratory response to exercise as well as in pathological states such as pulmonary hypertension or restrictive or obstructive lung disease