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What sort of justification can be claimed for abduction? In this paper we reconstruct Peirce's answer to this question. We show that in his early works on the logic of science Peirce provided an abductive justification of abduction, and that in his mature writings the early solution is enriched by a reference to the place abduction has in a typical scientific inquiry. Since abduction is the first stage of inquiry by which a hypothesis is suggested and which then has to be subjected to inductive testing, the fundamental abduction (ur -abduction) that justifies abduction has also to be subjected to a verification by means of a fundamental induction (ur -induction), namely that the abduction that abduction is valid is verified by an appeal to the history of science. • The first full account of the justification of abduction. • Exposes Peirce's original and unpublished material for abduction. • Links abduction with the logic of science. [ABSTRACT FROM AUTHOR]

This paper presents two major aspects of Frege's and Peirce's views on assertion and denial: first, their arguments for the notational choices concerning the representation of assertion and denial in Begriffsschrift (BS) and Existential Graphs (EGs), respectively; and second, those properties of BS and EGs which reflect their inventors' views on assertion and denial. We show that while Frege's notation has an ad hoc sign of assertion and an ad hoc sign of negation, Peirce has a sign of assertion which is also a sign of logical conjunction, and a sign of scope which is also a sign of negation. [ABSTRACT FROM AUTHOR]

Abstract: INTRODUCTION: Desmoid tumors are rare benign tumors that originates in the fibrous sheath or musculo-aponeurotic structure. Histologically benign, they tends to invade locally and to be recurrent. PRESENTATION OF CASE: We report a rare case of an intra-abdominal desmoid tumor in a patient affected by familial adenomatous polyposis, which degenerated into abscess. Male, 38 years, was hospitalized for abdominal pain, bowel obstruction and fever. The computed tomography showed a big dishomogeneous mass occupying the whole mesentery with internal massive liquefaction. The mass extended from the epigastrium for 13cm up to L3. On the right mesogastric side a solid, thick mass of about 2cm, with a length of 4.5cm, was identified; it was not cleavable from the wall and from some of the loops. We decided to perform a computed tomography-guided percutaneous drainage. Two hundred ml of purulent necrotic material was aspirated, and washing with antibiotic solution was carried out. Cytological examination of fluid drainage showed histiocytes and neutrophils. At follow-up, the patient's clinical condition had improved. An abdominal ultrasound showed a substantial reduction in the diameter of the mass. DISCUSSION: Diagnosis and treatment of desmoids tumor in patients with familial adenomatous polyposis may be difficult, especially when desmoids are located intra-abdominally and in the mesentery. Seldom will desmoid tumors be complicated by abscess formation. CONCLUSION: The management of desmoids tumors is not easy and the choice of the best treatment may be difficult due to the different possible anatomical presentations. [Copyright &y& Elsevier]

Abstract: INTRODUCTION: The Median Arcuate Ligament Syndrome is a rare condition characterized by postprandial abdominal pain, bowel function disorder and weight loss. We report the first case to our knowledge of Crohn''s disease and Median Arcuate Ligament Syndrome. PRESENTATION OF CASE: The patient was a 33 year-old female with a previous diagnosis of Crohn''s disease. Acute postprandial abdominal pain affected the patient every day; she was, therefore, referred to US-Doppler and magnetic resonance angiography of the abdominal vessels and received a diagnosis of Median Arcuate Ligament Syndrome. Consequently, the patient was surgically treated, releasing the vascular compression. After the operation, she reported a complete relief from postprandial pain which was one of her major concerns. Subocclusive symptoms occurred after six months due to the inflammatory reactivation of the terminal ileitis. DISCUSSION: The diagnosis of Median Arcuate Ligament Syndrome is mainly based on the exclusion of other intestinal disorders but it should be always confirmed using noninvasive tests such as US-Doppler, angio-CT or magnetic resonance angiography. CONCLUSION: This case demonstrates that the Median Arcuate Ligament Syndrome could be the major cause of symptoms, even in presence of other abdominal disorders. [Copyright &y& Elsevier]

This paper presents two major aspects of Frege's and Peirce's views on assertion and denial: first, their arguments for the notational choices concerning the representation of assertion and denial in Begriffsschrift (BS) and Existential Graphs (EGs), respectively; and second, those properties of BS and EGs which reflect their inventors' views on assertion and denial. We show that while Frege's notation has an ad hoc sign of assertion and an ad hoc sign of negation, Peirce has a sign of assertion which is also a sign of logical conjunction, and a sign of scope which is also a sign of negation. [ABSTRACT FROM AUTHOR]

Bio-mediated processes for arsenic (As) uptake in calcite were investigated by means of X-ray Diffraction (XRD) and X-ray Absorption Spectroscopy (XAS) coupled with X-ray Fluorescence measurements. The environmental bacterial strain Bacillus licheniformis BD5, sampled at the Bullicame Hot Springs (Viterbo, Central Italy), was used to synthesize calcite from As-enriched growth media. Both liquid and solid cultures were applied to simulate planktonic and biofilm community environments, respectively. Bacterial calcite samples cultured in liquid media had an As enrichment factor (Kd) 50 times higher than that from solid media. The XRD analysis revealed an elongation of the crystal lattice along the c axis (by 0.03 Å) for biogenic calcite, which likely resulted from the substitution of larger arsenate for carbonate in the crystal. The XAS data also showed a clear difference in the oxidation state of sorbed As between bacterial and abiotic calcite. Abiotic chemical processes yielded predominantly As(V) uptake whereas bacterial precipitation processes led to the uptake of both As(III) and As(V). The presence of As(III) in bacterial calcite is proposed to result from subsequent reduction of arsenate to arsenite by bacterial activities. To the best of our knowledge, this is the first experimental observation of the incorporation of As(III) in the calcite crystal lattice, revealing a critical role of biochemical processes for the As cycling in nature. [ABSTRACT FROM AUTHOR]

The reinforcement corrosion in Reinforced Concrete (RC) is a major reason of degradation for structures and infrastructures throughout the world leading to their premature deterioration before design life was attained. The effects of corrosion of reinforcement are: (i) the reduction of the cross section of the bars, and (ii) the development of corrosion products leading to the appearance of cracks in the concrete cover and subsequent cover spalling. Due to their intrinsic complex nature, these issues require an interdisciplinary approach involving both material science and structural design knowledge also in terms on International and National codes that implemented the concept of durability and service life of structures. In this paper preliminary FEM analyses were performed in order to simulate pitting corrosion or general corrosion aimed to demonstrate the possibility to extend the results obtained for a cylindrical specimen, reinforced by a single bar, to more complex RC members in terms of geometry and reinforcement. Furthermore, a mechanical analytical model to evaluate the stresses in the concrete surrounding the reinforcement bars is proposed. In addition, a sophisticated model is presented to evaluate the non-linear development of stresses inside concrete and crack propagation when reinforcement bars start to corrode. The relationships between the cracking development (mechanical) and the reduction of the steel section (electrochemical) are provided. Finally, numerical findings reported in this paper were compared to experimental results available in the literature and satisfactory agreement was found. [ABSTRACT FROM AUTHOR]