Arbitrage and deflators in illiquid markets

This paper presents a stochastic model for discrete-time trading in financial markets where trading costs are given by convex cost functions and portfolios are constrained by convex sets. The model does not assume the existence of a cash account/numeraire. In addition to classical frictionless markets and markets with transaction costs or bid-ask spreads, our framework covers markets with nonlinear illiquidity effects for large instantaneous trades. In the presence of nonlinearities, the classical notion of arbitrage turns out to have two equally meaningful generalizations, a marginal and a scalable one. We study their relations to state price deflators by analyzing two auxiliary market models describing the local and global behavior of the cost functions and constraints

Tensile strength assay comparing the resistance between two different autologous platelet concentrates (leucocyte-platelet rich fibrin versus advanced-platelet rich fibrin): a pilot study

Background: Since the leucocyte-platelet rich fibrin (L-PRF) was published in 2001, many studies have been developed, analyzing its properties, and also verifying new possibilities to improve it. Thereby, it emerges the advanced-platelet rich fibrin (A-PRF) with a protocol that optimizes the properties obtained by the L-PRF. Nonetheless, there is a gap in the literature to landmark the evolutive process concerning the mechanical properties in specific the resistance to tensile strength which consequently may influence the time for membrane degradation. Thus, this study had the goal to compare the resistance to the traction of membranes produced with the original L-PRF and A-PRF protocols, being the first to this direct comparison. Findings: The harvest of blood from a healthy single person, with no history of anticoagulant usage. We performed the protocols described in the literature, within a total of 13 membranes produced for each protocol (n = 26). Afterward, the membranes were prepared and submitted to a traction test assessing the maximal and the average traction achieved for each membrane. The data were analyzed statistically using the unpaired t test. Regarding average traction, A-PRF obtained a value of 0.0288 N mm−2 and L-PRF 0.0192 N mm−2 (p < 0.05 using unpaired t test). For maximal traction, A-PRF obtained 0.0752 N mm−2 and L-PRF 0.0425 N mm−2 (p < 0.05 using unpaired t test). Conclusion: With this study, it was possible to conclude that indeed A-PRF has a significative higher maximal traction score and higher average traction compared to L-PRF, indicating that it had a higher resistance when two opposing forces are applied.info:eu-repo/semantics/publishedVersio

Spontaneous Rupture of Spleen: A Case Report.

Spontaneous or idiopathic splenic rupture is a rare cause of acute abdominal pain and hemoperitoneum and its incidence is 1% of all cases of splenic rupture. The etiology of spontaneous splenic rupture can be idiopathic or it may occur as a complication of an infectious, neoplastic or hematologic disease. Splenic rupture presents with pain in the left upper quadrant with shock and features of peritoneal irritation, like Kehr’s sign (left shoulder pain due to diaphragmatic irritation) and Balance sign (palpable tender mass in left upper abdomen). The diagnosis of spontaneous splenic rupture presents a diagnostic challenge due to the absence of a history of trauma. Focused Abdominal Sonography for Trauma FAST may be suggestive but due to its limitations, Computerized Tomography Scan CT scan of abdomen is the best imaging modality both for detection and grading of splenic injury. Management can be non-operative or surgical depending on grade and hemodynamic status of the patient. We report a rare case of spontaneous rupture of the spleen, which was idiopathic and fulfills the criteria of Orloff and Peskin, due to absence of any history of trauma, absence of perisplenic adhesions or scarring, and it without any evidence of disease affecting the spleen with macro and microscopically normal spleen. This case also adheres to fifth criteria described by Crate and Payne, as there was no immunological evidence suggestive of any viral infections affecting the spleen

Social values of biodiversity conservation: for the endangered loggerhead turtle and monk seal.

The Mediterranean monk seal (Monachus monachus) and the loggerhead turtle (Caretta caretta) are two species on the priority list for conservation in Greece, due to their dwindling populations worldwide. Hence, the issue of estimating willingness-to-pay for their conservation is germane to any protection initiative. Zakynthos Island in Greece has created a marine park for the conservation of such species. We report the results of a survey of visitors and residents of this island who were asked about making one time donations in the form of either a tax for residents or a plane landing fee for tourists. We found that all people were willing-to-pay to protect these species; however, residents were willing-to-pay more than tourists. We then tested whether there was a sequence or ordering effect if the seal questions came before the turtles, as well as if the turtle questions came before the seals. Such effect was found when turtle questions were presented first, but not when seal questions were presented first. Due to the extensive interest, it is recommended that an increase in the airplane landing fee to Zakynthos could be used to contribute towards funds for loggerhead turtle and monk seal protection

Regenerative endodontic treatment of perforated internal root resorption: a case report

WOS: 000417573100015PubMed ID: 28439906AimTo present the regenerative endodontic treatment procedure of a perforated internal root resorption case and its clinical and radiographic findings after 2years. SummaryA 14-year-old female patient was referred complaining of moderate pain associated with her maxillary left lateral incisor. After radiographic examination, a perforated internal resorption lesion in the middle third of tooth 22 was detected. Under local anaesthesia and rubber dam isolation, an access cavity was prepared and the root canal was shaped using K-files under copious irrigation with 1% NaOCl, 17% EDTA and distilled water. At the end of the first and second appointments, calcium hydroxide (CH) paste was placed in the root canal using a lentulo. After 3months, the CH paste was removed using 1% NaOCl and 17% EDTA solutions and bleeding in the root canal was achieved by placing a size 20K-file into the periapical tissues. Mineral trioxide aggregate was then placed over the blood clot. The access cavity was restored using glass-ionomer cement and resin composite. After 2years, the tooth was asymptomatic and radiographic examination revealed hard tissue formation in the perforated resorption area and remodelling of the root surface. Key learning points Regenerative endodontic treatment procedures are an alternative approach to treat perforated internal root resorption lesions. Calcium hydroxide was effective as an intracanal medicament in regenerative endodontic treatment procedures