Fixed-point elimination in the intuitionistic propositional calculus

It is a consequence of existing literature that least and greatest fixed-points of monotone polynomials on Heyting algebras-that is, the algebraic models of the Intuitionistic Propositional Calculus-always exist, even when these algebras are not complete as lattices. The reason is that these extremal fixed-points are definable by formulas of the IPC. Consequently, the $\mu$-calculus based on intuitionistic logic is trivial, every $\mu$-formula being equivalent to a fixed-point free formula. We give in this paper an axiomatization of least and greatest fixed-points of formulas, and an algorithm to compute a fixed-point free formula equivalent to a given $\mu$-formula. The axiomatization of the greatest fixed-point is simple. The axiomatization of the least fixed-point is more complex, in particular every monotone formula converges to its least fixed-point by Kleene's iteration in a finite number of steps, but there is no uniform upper bound on the number of iterations. We extract, out of the algorithm, upper bounds for such n, depending on the size of the formula. For some formulas, we show that these upper bounds are polynomial and optimal

hungry bone syndrome after parathyroidectomy for primary hyperthyroidism

Parathyroidectomy is the treatment of choice in patients with primary hyperparathyroidism (PHPT). This disease affects calcium metabolism at the level of bone tissue and renal tubules, resulting in hypercalcaemia, often asymptomatic, associated with hypophosphataemia and hypomagnesaemia. Sudden suppression of parathyroid hormone (PTH), caused by successful parathyroidectomy, in patients with preoperative high levels of PTH and hypercalcaemia from enhanced bone turnover, may induce severe postoperative hypocalcaemia that may lead to symptoms of tetany. This relatively uncommon condition is known as "hungry bone syndrome" (HBS), because it is believed to be due mainly to enhanced bone formation. Several risk factors have been advocated for HBS, and the syndrome is reported to be more likely to rise in subjects with severe preoperative bone disease. Other modifiable risk factors are preoperative vitamin D deficiency and high PTH and calcium levels. Treatment of HBS is basically the administration of high amounts of calcium immediately after the onset of postoperative hypocalcaemia. Supplements of active metabolites of vitamin D, as well as magnesium in depleted subjects are complementary in supporting bone remineralization. Oral supplementation may be requested for months after parathyroidectomy. Prevention is poorly documented, but it is reasonable to propose the correction of vitamin D deficit and the use of bisphosphonates aimed to lower PTH levels and bone resorption before parathyroidectomy

Finitely generated free Heyting algebras via Birkhoff duality and coalgebra

Algebras axiomatized entirely by rank 1 axioms are algebras for a functor and thus the free algebras can be obtained by a direct limit process. Dually, the final coalgebras can be obtained by an inverse limit process. In order to explore the limits of this method we look at Heyting algebras which have mixed rank 0-1 axiomatizations. We will see that Heyting algebras are special in that they are almost rank 1 axiomatized and can be handled by a slight variant of the rank 1 coalgebraic methods

Molecular dynamics simulation of aqueous solutions of 26-unit segments of p(NIPAAm) and of p(NIPAAm) "doped" with amino acid based comonomers

We have performed 75-ns molecular dynamics (MD) simulations of aqueous solutions of a 26-unit NIPAAm oligomer at two temperatures, 302 and 315 K, below and above the experimentally determined lower critical solution temperature (LCST) of p(NIPAAm). We have been able to show that at 315 K the oligomer assumes a compact form, while it keeps a more extended form at 302 K. A similar behavior has been demonstrated for a similar NIPAAm oligomer, where two units had been substituted by methacryloyl-l-valine (MAVA) comonomers, one of them being charged and one neutral. For another analogous oligomer, where the same units had been substituted by methacryloyl-l-leucine (MALEU) comonomers, no transition from the extended to the more compact conformation has been found within the same simulation time. Statistical analysis of the trajectories indicates that this transition is related to the dynamics of the oligomer backbone, and to the formation of intramolecular hydrogen bonds and water-bridges between distant units of the solute. In the MAVA case, we have also evidenced an important role of the neutral MAVA comonomer in stabilizing the compact coiled structure. In the MALEU case, the corresponding comonomer is not equally efficacious and, possibly, is even hindering the readjustment of the oligomer backbone. Finally the self-diffusion coefficient of water molecules surrounding the oligomers at the two temperatures for selected relevant times is observed to characteristically depend on the distance from the solute molecules

New insights into cortico-basal-cerebellar connectome: clinical and physiological considerations

The current model of the basal ganglia system based on the 'direct', 'indirect' and 'hyperdirect' pathways provides striking predictions about basal ganglia function that have been used to develop deep brain stimulation approaches for Parkinson's disease and dystonia. The aim of this review is to challenge this scheme in light of new tract tracing information that has recently become available from the human brain using MRI-based tractography, thus providing a novel perspective on the basal ganglia system. We also explore the implications of additional direct pathways running from cortex to basal ganglia and between basal ganglia and cerebellum in the pathophysiology of movement disorders

How to assess appearance distress and motivation in plastic surgery candidates: Italian validation of Derriford Appearance Scale 59 (DAS 59)

The Derriford Appearance Scale (DAS) 59 was specifically designed to measure psychosocial adjustment in patients with appearance problems. Previous studies using the DAS59 have proven it to be a reliable method of assessing the appearance-related quality of life after plastic surgery procedures. The aim of this study was to develop a valid and reliable Italian version of the DAS59

Unexpected thymoma in a challenging case of hyperparathyroidism

We report the case of a woman with primary hyperparathyroidism suspected of mediastinal ectopic parathyroid adenoma revealed to be a thymoma. Our aim was to focus on some possible criticisms in distinguishing between ectopic parathyroid and thymus

Pre-operative diagnosis of an unusual complication of abdominal aortic aneurysm on multidetector computed tomography: a case report

Spontaneous fistulation of an abdominal aortic aneurysm (AAA) into the inferior vena cava (IVC) is an unusual and infrequently encountered complication in clinical practice. In the majority of cases, it is a diagnosis made on the operating table, during surgical repair of AAA. We report a patient with an aortocaval fistula diagnosed preoperatively on multidetector computed tomography (MDCT). Preoperative diagnosis of this rare complication is important as it allows appropriate anaesthetic and surgical planning thereby reducing morbidity and mortality

THE LONG TRAIL: A CHIMERA-LIKE FOSSIL CRUSTACEAN INTERPRETED AS DECAPODA, STOMATOPODA, AMPHIPODA AND FINALLY ISOPODA

The process of interpreting and evaluating a fossil is a difficult task. Isopoda is a species rich group of peracarid eumalacostracans which represent quite a challenge when found as fossils, independent of whether we are working with fragmentary or more complete specimens. Here we describe a new fossil species of crustacean, Platuropodus odysseus n. gen. n. sp., from the Irati Formation, Permian of Paraná Basin, Brazil. After misinterpretations, the fossil taxon is recognised here as a representative of Isopoda. The new species presents characters found in Phreatoicidea, Asellota and Oniscidea in a unique combination for the fossil and extant record, such as two pairs of sub-chelate anterior trunk appendages, a short region after the anus and flat uropods. This chimera-like morphology and a morphometric analysis of the sub-chelae indicate convergent evolution in the early diversification of Isopoda. The morphological diversification present in the Palaeozoic and Mesozoic fossil record of Eumalacostraca indicate a “push of the past” effect in different ingroups of Peracarida

The Seasonal Variation of the Chemical Composition of Essential Oils from Porcelia macrocarpa RE Fries (Annonaceae) and Their Antimicrobial Activity

This study investigates the impact of seasonal variation on the chemical composition of essential oils from the leaves of Porcelia macrocarpa (Annonaceae) obtained over the course of one year (January-December 2011) and the chemical composition of the essential oils obtained from the ripe fruits of the same plant. Furthermore, the essential oils of the leaves were investigated with respect to their antimicrobial activity. the essential oils of the leaves contain a mixture of monoterpenes, one diterpene and several sesquiterpenes. the main components were identified as the sesquiterpenes germacrene D (29%-50%) and bicyclogermacrene (24%-37%). No significant variation was observed for the composition of the essential oil of the leaves over the course of the year, except for the month of November, when the ripe fruit were collected. in this month, substantially decreased concentrations of germacrene D (28.8 +/- 0.8%) and bicyclogermacrene (23.9 +/- 0.6%) were measured and the emergence of spathulenol (10.4 +/- 0.2%) was observed. the essential oils extracted from the ripe fruit revealed the presence of a variety of monoterpenes, sesquiterpenes and hydrocarbons. the main constituents of these oils were neryl (8.8 +/- 0.2%) and geranyl (27.3 +/- 0.7%) formates, gamma-muurolene (10.3 +/- 0.9%) and dendrolasin (8.23 +/- 0.06%). the antimicrobial activity of the essential oil obtained from the leaves of P. macrocarpa towards a range of bacterial and yeast strains was examined. in order to determine the minimum inhibitory concentration (MIC) of essential oils obtained from the January collection of the leaves, broth microdilution assays were carried out, which showed a significant antimicrobial activity towards Cryptococcus neoformans serotypes A and D as well as C. gattii serotypes B and C.Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Universidade Federal de São Paulo, Inst Ciencias Ambientais Quim & Farmaceut, BR-09972270 Diadema, SP, BrazilUniv Fed Alfenas, Inst Quim, BR-37130000 Alfenas, MG, BrazilUniversidade Federal de São Paulo, Inst Ciencias Ambientais Quim & Farmaceut, BR-09972270 Diadema, SP, BrazilCNPq: 300546/2012-2FAPESP: 2011/51739-0Web of Scienc