On the Expressive Power of Multiple Heads in CHR

Constraint Handling Rules (CHR) is a committed-choice declarative language which has been originally designed for writing constraint solvers and which is nowadays a general purpose language. CHR programs consist of multi-headed guarded rules which allow to rewrite constraints into simpler ones until a solved form is reached. Many empirical evidences suggest that multiple heads augment the expressive power of the language, however no formal result in this direction has been proved, so far. In the first part of this paper we analyze the Turing completeness of CHR with respect to the underneath constraint theory. We prove that if the constraint theory is powerful enough then restricting to single head rules does not affect the Turing completeness of the language. On the other hand, differently from the case of the multi-headed language, the single head CHR language is not Turing powerful when the underlying signature (for the constraint theory) does not contain function symbols. In the second part we prove that, no matter which constraint theory is considered, under some reasonable assumptions it is not possible to encode the CHR language (with multi-headed rules) into a single headed language while preserving the semantics of the programs. We also show that, under some stronger assumptions, considering an increasing number of atoms in the head of a rule augments the expressive power of the language. These results provide a formal proof for the claim that multiple heads augment the expressive power of the CHR language.Comment: v.6 Minor changes, new formulation of definitions, changed some details in the proof

Celiac disease diagnosed in an older adult patient with a complex neuropsychiatric involvement: a case report and review of the literature

We present a case of celiac disease (CD) diagnosis in a 75-year-old woman with a long-term history of chronic delusional jealousy and a complex neurological involvement. The case describes a very unusual clinical picture, provides some clinical clues, and highlights the importance of being aware of CD extraintestinal manifestations in order to get a timely diagnosis

Infestazione intestinale da Schistosoma mansoni: un caso emblematico di importazione

Viene descritto, sia dal punto di vista clinico che parassitologico, un caso di importazione di schistosomiasi intestinale da S. mansoni contratta durante un soggiorno in Tanzania. Dopo circa 50 giorni da un contatto casuale ma ripetuto con le acque del Lago Vittoria, al soggetto, giovane adulto in missione umanitaria, compare febbre elevata, accompagnata da astenia (presente da più giorni) cui segue un episodio di diarrea acuta. La comparsa anche di una ipereosinofilia, dapprima assente, spinge il curante ad eseguire immediatamente un esame coproparassitologico standard (in precedenza sempre negativo) che risulta positivo per uova di S. mansoni. La terapia condotta con praziquantel risolve il caso e porta a guarigione il soggetto, cui inizialmente era stata esclusa la malaria, allorché dopo circa 1 mese dal rientro aveva presentato rialzo termico con disturbi respiratori

Performance of Circulating Placental Growth Factor as A Screening Marker for Diagnosis of Ovarian Endometriosis: A Pilot Study

The aim of this study is to compare the circulating placental growth factor (PlGF) concentration in women with and without endometrioma to verify the performance of this marker to diagnose the disease

Vitamin B6 rescues insulin resistance and glucose-induced DNA damage caused by reduced activity of Drosophila PI3K

: The insulin signaling pathway controls cell growth and metabolism, thus its deregulation is associated with both cancer and diabetes. Phosphatidylinositol 3-kinase (PI3K) contributes to the cascade of phosphorylation events occurring in the insulin pathway by activating the protein kinase B (PKB/AKT), which phosphorylates several substrates, including those involved in glucose uptake and storage. PI3K inactivating mutations are associated with insulin resistance while activating mutations are identified in human cancers. Here we show that RNAi-induced depletion of the Drosophila PI3K catalytic subunit (Dp110) results in diabetic phenotypes such as hyperglycemia, body size reduction, and decreased glycogen content. Interestingly, we found that hyperglycemia produces chromosome aberrations (CABs) triggered by the accumulation of advanced glycation end-products and reactive oxygen species. Rearing PI3KRNAi flies in a medium supplemented with pyridoxal 5'-phosphate (PLP; the catalytically active form of vitamin B6) rescues DNA damage while, in contrast, treating PI3KRNAi larvae with the PLP inhibitor 4-deoxypyridoxine strongly enhances CAB frequency. Interestingly, PLP supplementation rescues also diabetic phenotypes. Taken together, our results provide a strong link between impaired PI3K activity and genomic instability, a crucial relationship that needs to be monitored not only in diabetes due to impaired insulin signaling but also in cancer therapies based on PI3K inhibitors. In addition, our findings confirm the notion that vitamin B6 is a good natural remedy to counteract insulin resistance and its complications

Discrepancies between explicit and implicit evaluation of aesthetic perception ability in individuals with autism: a potential way to improve social functioning

Background: The capacity to evaluate beauty plays a crucial role in social behaviour and social relationships. It is known that some characteristics of beauty are important social cues that can induce stereotypes or promote different behavioural expectations. Another crucial capacity for success in social interactions is empathy, i.e. the ability to understand and share others\u2019 mental and emotional states. Individuals with Autism Spectrum Disorder (ASD) have an impairment of empathic ability. We showed in a previous study that empathy and aesthetic perception abilities closely related. Indeed, beauty can affect different aspects of empathic behaviour, and empathy can mediate the aesthetic perception in typically developing (TD) individuals. Thus, this study evaluates the ability of aesthetic perception in ASD individuals compared to TD individuals, using the Golden Beauty behavioural task adapted for eye-tracking in order to acquire both explicit and implicit evidences. In both groups, the relationship between empathic and aesthetic perception abilities was also evaluated. Methods: Ten ASD individuals (age \ub1 SD:20.7 \ub1 4.64) and ten TD individuals (age \ub1 SD:20.17 \ub1 0.98) participated in the study. Participants underwent empathy tasks and then the Golden Beauty task. To assess differences in the participants\u2019 performance, we carried out a repeated measures general linear model. Results: At the explicit level, our behavioural results show an impairment in aesthetic perception ability in ASD individuals. This inability could have relevance for their ability to experience pleasure during social interactions. However, at the implicit level (eye-tracking results), ASD individuals conserved a good ability to feel aesthetic pleasure during the Golden Beauty task, thus indicating a discrepancy between the explicit and implicit evaluation of the beauty task. Finally, beauty perception appears to be linked to empathy when neither of these capacities is compromised, as demonstrated in the TD group. In contrast, this link lacks in ASD individuals