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

Use of cactus pear pruning waste to improve soil properties and to produce high-quality compost

Bio-fertilizers could be a possible solution to help manage bio-waste problems and to maintain soil health conditions, especially in organic farms. Pruning of cactus pear produces from 6 to 10 tons/yearly of cladodes per hectare in specialized Italian orchards, which represents waste and a cost for disposal to farmers. Therefore, the aim of the work was to investigate the effects on soil physical properties, microflora activity, and basil plant growth of powdered pruning waste from cactus pear incorporated in the soil (10%, 20%, 30% 40% w/w). Moreover, we studied a dynamic composting process from fresh cladodes to produce stabilized end-products at the farm level. Our studies demonstrated that holding water ability and bulk density of soil were ameliorated by supplementing dried cladodes. Thus, gravitational and gravimetric water was positively correlated with the increase of added dried cladode in the soil (0.1% and 6.2 g H2O +/- 0.3 in samples of 40% mixed soil versus 68% and 3.3 g H2O +/- 0.3 in control). Furthermore, bulk density was reduced limiting soil compaction. Preliminary results on microbial activity suggested a possible selection/inhibition of some bacterial strains correlated with the increment of dry cladode supplementation. The basil plants grown in 20% mixed soil showed an increased biomass when compared to the control (+ 21%). Finally, raw cladode proved to be an excellent substrate for aerobic fermentation providing a final product of good quality and high moisture content (65%). These results are particularly relevant in organic agriculture where bio-fertilizers are recommended as economical, eco-friendly solution accessible also to marginal and small farms

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