Intact colonic motor response to sudden awakening from sleep in patients with chronic idiopathic (slow-transit) constipation

PURPOSE: There are few data about the relationships between colonic motor behavior and higher brain functions, such as sleep. Previous studies were done in healthy subjects, and it is unknown whether patients with functional motor disorders of the colon behave differently. This study was designed to characterize colonic motor activity in patients with constipation, both during sleep and after sudden awakening, and to compare it with that of healthy subjects. Our working hypothesis was that patients with constipation would have an impaired response to sudden awakening. PATIENTS AND METHODS: Twelve chronically constipated women, 22 to 49 years old, were recruited for the study, and their data were compared with those obtained from 12 healthy female volunteers, 21 to 38 years old. Manometric studies were performed in the descending and sigmoid colon for 30 minutes during sleep (immediately before awakening) and 30 minutes after being awakened suddenly. A motility index was calculated before and after the stimulus. RESULTS: In both groups motility in the descending and the sigmoid colon was almost absent during sleep and significantly increased after sudden awakening. No difference in postawakening values was found between patients with constipation and controls. CONCLUSIONS: In patients with chronic constipation, the brain-gut control of some fundamental mechanisms governing colonic motility is preserved. These data suggest that the alterations of colonic motility described in chronic constipation may be caused by an intrinsic dysfunction of the viscus.     

Preface: Towards Adaptation of Interaction to Affective Factors

User Modeling and User-Adapted Interaction -     

Panel discussion

This document is a summary of the panel discussion that was held at the workshop. Rather than recording the speakers' contributions, we asked them to summarize their views in a text. The document is organized according to the questions that were discussed in the panel. This discussion was collected and revised by Fiorella de Rosis and Eva Hudlicka.     

Some factors influencing patulin production by Penicillium expansum in pome fruits

BACKGROUND: The objective of our study was to examine the effects of Penicillium expansum on patulin production in relation to isolates, species and cultivar type, incidence and severity of decay. In addition, patulin production at different incubation times and its diffusion were also investigated. These factors were evaluated in pome fruits inoculated with P. expansum and kept at 20 °C for short periods of time. RESULTS: The ability of five P. expansum isolates to grow and produce patulin in inoculated Golden Delicious apples varied among the strains from below the limit of quantification to 662 µg kg^?1. Variety and species of pome fruits influenced patulin production. P. expansum isolate PE97.IT produced a higher patulin content in apples than in pears. The highest patulin production was 386 µg kg^?1 in Golden Delicious. No blue mould symptom appeared in pears inoculated with P. expansum and no patulin was detected after 3 days at 20 °C. However, patulin increased with incubation time after 6 and 8 days. No patulin was detected in healthy pear tissue but it was high in the decayed area. CONCLUSION: Since patulin production is associated primarily with infected rotten tissue, patulin control is possible by using healthy fruits, sorting damaged and rotten fruits before processing. Copyright © 2010 Society of Chemical Industry     

Nature and roles for community networks in the information society

This paper draws on the authors more than 10 years of involvement in the action research experience of the Milan Community Network. It discusses the roles that community networks play in the Information Society: starting from a neat characterization of “online community”, community networks are presented as ICT learning communities, as local online communities and as complementary to Digital Cities. Finally, critical insights into institutional aspects of community networks are considered from the perspective of their sustainability.     

Modern perspectives in supercomputer-aided microwave circuit design

The computer-aided simulation and design of microwave integrated circuits often leads to large-size numerical jobs, especially for modern multiple-device MMIC subsystems such as distributed mixers and amplifiers. When this is the case, the use of large computer systems such as vector processors may become very attractive, because of the dramatic reduction of wall-clock time and of the related improvement of cost-to-performance ratio. This paper discusses the application of supercomputers to the solution of a number of such advanced microwave circuit CAD problems. An overview of the performance of general-purpose vectorized algorithms such as system solvers and Fast Fourier Transforms is first presented, in order to give a feeling of the potential of this class of machines in microwave CAD applications. Then a few typical microwave engineering problems are specifically addressed, including the statistical design (yield optimization) of linear circuits, the analysis of nonlinear circuits under multitone excitation, and the optimization of ultrabroadband nonlinear subsystems. In each case, a possible vectorization strategy is studied in depth, and the structure and performance of a specific highly vectorized algorithm are described in detail.     

Chemical synthesis of the RGD-protein decorsin: Pro-->Ala replacement reduces protein thermostability

Decorsin is a 39-residue polypeptide chain, crosslinked by three disulfide bridges, that strongly inhibits platelet aggregation. We report the chemical synthesis and characterization of analogs of decorsin with the aim of investigating the role of proline residues in protein structure, stability and biological activity. Decorsin analogs have been synthesized in which one (P23A and P24A decorsin) or two (P23,24A decorsin) proline residues have been substituted by alanine. The crude synthetic polypeptides were purified by reversed-phase HPLC in their reduced form and allowed to refold oxidatively to their disulfide-crosslinked species. The homogeneity of the synthetic mini-proteins, and also the correct pairing of the three disulfide bridges, were established by a number of analytical criteria, including fingerprinting analysis of the refolded synthetic analogs by using thermolysin and proteinase K as proteolytic enzymes. Replacement of proline by alanine results in a significant and cumulative decrease of the high thermal stability (Tm 74 degrees C) of native decorsin. The mono-substituted analogs display a Tm of 66-67 degrees C, while the double-substituted analog a Tm of 50 degrees C. On the other hand, the overall secondary and tertiary structures were not affected by the Pro-->Ala exchanges, as judged from circular dichroism measurements. Platelet aggregation assays established that the proline substitutions do not impair significantly the biological activity of decorsin. The results of this study clearly indicate that proline residues contribute significantly to the protein thermal stability. Our results are in line with the 'proline rule', previously advanced for explaining the unusual thermal stability of thermophilic enzymes, which usually show an enhanced content of proline residues with respect to their mesophilic counterparts.     

Isotropic microscale mechanical properties of coral skeletons

Scleractinian corals are a major source of biogenic calcium carbonate, yet the relationship between their skeletal microstructure and mechanical properties has been scarcely studied. In this work, the skeletons of two coral species: solitary Balanophyllia europaea and colonial Stylophora pistillata, were investigated by nanoindentation. The hardness H_IT and Young''s modulus E_IT were determined from the analysis of several load–depth data on two perpendicular sections of the skeletons: longitudinal (parallel to the main growth axis) and transverse. Within the experimental and statistical uncertainty, the average values of the mechanical parameters are independent on the section''s orientation. The hydration state of the skeletons did not affect the mechanical properties. The measured values, E_IT in the 76–77 GPa range, and H_IT in the 4.9–5.1 GPa range, are close to the ones expected for polycrystalline pure aragonite. Notably, a small difference in H_IT is observed between the species. Different from corals, single-crystal aragonite and the nacreous layer of the seashell Atrina rigida exhibit clearly orientation-dependent mechanical properties. The homogeneous and isotropic mechanical behaviour of the coral skeletons at the microscale is correlated with the microstructure, observed by electron microscopy and atomic force microscopy, and with the X-ray diffraction patterns of the longitudinal and transverse sections.