A Test of the Rational Expectations Hypothesis using data from a Natural Experiment

Data on contestants' choices in Italian Game Show Affari Tuoi are analysed in a way that separates the effect of risk attitude (preferences) from that of beliefs concerning the amount of money that will be offered to contestants in future rounds. The most important issue addressed in the paper is what belief function is actually being used by contestants. The parameters of this function are estimated freely along with the parameters of a choice model. Separate identification of the belief function and preferences is possible by virtue of the fact that at a certain stage of the game, beliefs are not relevant, and risk attitude is the sole determinant of choice. The rational expectations hypothesis is tested by comparing the estimated belief function with the "true" offer function which is estimated using data on offers actually made to contestants. We find that there is a significant difference between these two functions, and hence we reject the rational expectations hypothesis. However, when a simpler "rule-of-thumb" structure is as- sumed for the belief function, we find a correspondence to the function obtained from data on actual offers. Our overall conclusion is that contestants are rational to the extent that they make use of all available relevant information, but are not fully rational because they are not processing the information in an optimal way. The importance of belief-formation is confirmed by the estimation of a mixture model which establishes that the vast majority of contestants are forward-looking as opposed to myopic.Beliefs, Discrete choice models, Method of simulated likelihood, Natural Experiments, rational expectations, risky choice

Changes in protein expression in two cholangiocarcinoma cell lines undergoing formation of multicellular tumor spheroids In vitro

Epithelial-to-Mesenchymal Transition (EMT) is relevant in malignant growth and frequently correlates with worsening disease progression due to its implications in metastases and re- sistance to therapeutic interventions. Although EMT is known to occur in several types of solid tumors, the information concerning tumors arising from the epithelia of the bile tract is still limited. In order to approach the problem of EMT in cholangiocarcinoma, we decided to investigate the changes in protein expression occurring in two cell lines under conditions leading to growth as adherent monolayers or to formation of multicellular tumor spheroids (MCTS), which are considered culture models that better mimic the growth characteristics of in-vivo solid tumors. In our system, changes in phenotypes occur with only a decrease in transmembrane E-cadherin and vimentin expression, minor changes in the transglutami- nase protein/activity but with significant differences in the proteome profiles, with declining and increasing expression in 6 and in 16 proteins identified by mass spectrometry. The aris- ing protein patterns were analyzed based on canonical pathways and network analysis. These results suggest that significant metabolic rearrangements occur during the conver- sion of cholangiocarcinomas cells to the MCTS phenotype, which most likely affect the car- bohydrate metabolism, protein folding, cytoskeletal activity, and tissue sensitivity to oxygen

Risk attitude in real decision problems

Experimental economics focuses on eliciting preferences, studying individuals one at a time to take into account their heterogeneity. Experiments have the appealing property of collecting enough observations to perform such an analysis. In real word, and in natural experiments, individuals cannot be observed according to experimenters’ needs. We propose a method that aggregates over individuals taking into account their heterogeneity. Using data from a natural experiment, we estimate three models of decision making under risk: Expected Utility, Rank-Dependent Expected Utility and Regret-Rejoice. Our results show that individual-wise analyses can be substituted by pooled approaches without losing information about individual heterogeneity.Experimental economics focuses on eliciting preferences, studying individuals one at a time to take into account their heterogeneity. Experiments have the appealing property of collecting enough observations to perform such an analysis. In real word, and in natural experiments, individuals cannot be observed according to experimenters’ needs. We propose a method that aggregates over individuals taking into account their heterogeneity. Using data from a natural experiment, we estimate three models of decision making under risk: Expected Utility, Rank-Dependent Expected Utility and Regret-Rejoice. Our results show that individual-wise analyses can be substituted by pooled approaches without losing information about individual heterogeneity

In-situ procjena zidanih svodova: Dinamička ispitivanja i numerička analiza

This paper concerns the structural identification of historical masonry buildings with reference to a case study, which is discussed in detail. The building is located in Southern Italy (Lecce). It has an ancient vaulted roof that is complex and commonly found in old masonry structures. This study takes advantage of extensive historical and structural investigations of the building. Preliminary activities have been conducted to obtain information about the current state of the structure including the geometry, morphology, structural details, material properties, prior interventions, and existing damage. This process was supported by an historical investigation into the conceptual background and construction methods used to build the structure. After the historical investigation, a series of experiments, including dynamic tests, were conducted on a number of the vaults to determine their dynamic response characteristics under operational conditions. A numerical model was also determined. In this paper, the primary dynamic test results and modelling assumptions are reported. Comparisons between numerical and experimental results are discussed.U ovom se članku razmatra konstrukcija jedne kulturno-povijesne zidane zgrade, detaljno obrađena još u jednoj ranijoj studiji. Zgrada se nalazi u Južnoj Italiji (Lecce). Zgrada ima složenu konstrukciju krova, sa svodovima, kakva je česta kod starih zidanih zgrada. U članku se uzimaju u obzir ranija opsežna povijesna i statička istraživanja. Ta ranija istraživanja bila su usmjerena ka dobivanju informacija o prethodnim ispitivanjima te o sadašnjem stanju konstrukcije, uključujući geometrijske karakteristike, oblikovnost, konstruktivne detalje, svojstva materijala i oštećenja zgrade. Pri tome su pomogla i ranija istraživanja o koncepciji i načinu gradnje zgrade. Nakon ovih istraživanja, obavljene su serije ispitivanja, između ostalog i dinamički pokusi na mnogim svodovima da se ustanove svojstva njihovog dinamičkog odziva u uvjetima standardne uporabe. Postavljen je i numerički model. U ovom su članku prikazani rezultati prvih dinamičkih ispitivanja i svojstava modela. Diskutira se odnos rezultata dobivenih numerički i eksperimentalno

The adherent/invasive escherichia coli (AIEC) strain LF82 invades and persists in human prostate cell lineRWPE-1 activating a strong inflammatory response

Adherent/invasive Escherichia coli (AIEC) strains have recently been receiving increased attention because they are more prevalent and persistent in the intestine of Crohn's disease (CD) patients than in healthy subjects. Since AIEC strains show a high percentage of similarity to extraintestinal pathogenic E. coli (ExPEC), neonatal meningitis-associated E. coli (NMEC), and uropathogenic E. coli (UPEC) strains, here we compared AIEC strain LF82 with a UPEC isolate (strain EC73) to assess whether LF82 would be able to infect prostate cells as an extraintestinal target. The virulence phenotypes of both strains were determined by using the RWPE-1 prostate cell line. The results obtained indicated that LF82 and EC73 are able to adhere to, invade, and survive within prostate epithelial cells. Invasion was confirmed by immunofluorescence and electron microscopy. Moreover, cytochalasin D and colchicine strongly inhibited bacterial uptake of both strains, indicating the involvement of actin microfilaments and microtubules in host cell invasion. Moreover, both strains belong to phylogenetic group B2 and are strong biofilm producers. In silico analysis reveals that LF82 shares with UPEC strains several virulence factors: namely, type 1 pili, the group II capsule, the vacuolating autotransporter toxin, four iron uptake systems, and the pathogenic island (PAI). Furthermore, compared to EC73, LF82 induces in RWPE-1 cells a marked increase of phosphorylation of mitogen-activated protein kinases (MAPKs) and of NF-κB already by 5 min postinfection, thus inducing a strong inflammatory response. Our in vitro data support the hypothesis that AIEC strains might play a role in prostatitis, and, by exploiting host-cell signaling pathways controlling the innate immune response, likely facilitate bacterial multiplication and dissemination within the male genitourinary trac

Computational Model for Delamination Growth at SMA-GFRP Interface of Hybrid Composite

AbstractA cohesive model of the new interface of the CuZnAl SMA/GFRP hybrid composite is proposed and the interfacial delamination under Mode II loading conditions, between plain CuZnAl SMA sheet insert and GFRP matrix, as well as between CuZnAl SMA sheet insert having elliptical hole pattern and GFRP matrix, are studied in detail.The results of the pull-out tests with plain sheet insert are used to calculate the interfacial parameters of the hybrid composite. With these parameters, the cohesive interaction and failure mechanism for hybrid composite with plain sheet, as well as with patterned sheet insert, is modelled. The efficacy of the laser patterned SMA sheet inserts to improve the overall interfacial strength in the new laminated SMA/GFRP hybrid composite for applications, such as light weight and high damping material under dynamic loads, is validated

Cohesive surface model for delamination and dynamic behavior of hybrid composite with SMA-GFRP interface

The interface model between CuZnAl SMA and GFRP, used in a hybrid composite, is proposed using cohesive surfaces. Using this model and derived parameters, mode-II delamination is studied between CuZnAl SMA insert and GFRP and also between laser patterned CuZnAl SMA insert and GFRP. Natural frequency and damping ratio of the hybrid composite specimen, in the shape of slender beam in a cantilever configuration, are evaluated in impulse tests. A numerical model is also presented, to calculate the aforementioned dynamic properties numerically, using Modal Strain Energy (MSE) and Modal Dynamics procedures by considering the derived interfacial parameters. Keywords: Hybrid composite, Delamination, FE analysis, Cohesive interface, Damage initiation, Modal dynamic

The Shigella flexneri OmpA amino acid residues 188EVQ190 are essential for the interaction with the virulence factor PhoN2

Shigella flexneri is an intracellular pathogen that deploys an arsenal of virulence factors promoting host cell invasion, intracellular multiplication and intra- and inter-cellular dissemination. We have previously reported that the interaction between apyrase (PhoN2), a periplasmic ATP-diphosphohydrolase, and the C-terminal domain of the outer membrane (OM) protein OmpA is likely required for proper IcsA exposition at the old bacterial pole and thus for full virulence expression of Shigella flexneri (Scribano et al., 2014). OmpA, that is the major OM protein of Gram-negative bacteria, is a multifaceted protein that plays many different roles both in the OM structural integrity and in the virulence of several pathogens. Here, by using yeast two-hybrid technology and by constructing an in silico 3D model of OmpA from S. flexneri 5a strain M90T, we observed that the OmpA residues 188EVQ190 are likely essential for PhoN2-OmpA interaction. The 188EVQ190 amino acids are located within a flexible region of the OmpA protein that could represent a scaffold for protein-protein interaction

Characterization of the ear canal bacterial flora present in hearing Aids (HA) wearing subjects

The use of hearing aids (HA) is considered a predisposing factor for ear microbial infections. We undertook this study to compare the presence and nature of the microbial flora inhabiting of ears of HA and non-HA (nHA) users. Swab samples of the ears of HA and nHA users were collected from the Institute of Otolaryngology, “Cattolica del Sacro Cuore” University “Agostino Gemelli”, Rome, Italy. Swab samples were taken from the ear canal of 57 HA and 33 nHA users. The components of the microbial flora present on each swab sample were identified and characterized at the level of species. A total of 41 different bacterial species were identified. A statistically significant prevalence of polymicrobial communities was found in ears presenting signs of inflammation (2.5 ± 1.7 vs 2.1 ± 1.3; P = 0.02) and in HA users (2.3 ± 1.2 vs 1.7 ± 1.0; P = 0.002). Few putative pathogens were detected. Candida albicans spp. was not isolated in our study. A small number of swab samples presented no microbial growth. Bacterial species isolated from HA users with and without inflammation were assayed for the ability to form a biofilm. Among gram-positive and gram-negative bacteria, S. aureus, CoNS, P. aeruginosa, and K. pneumoniae were found to be strong biofilm producers. S. aureus and P. aeruginosa, isolated only from the ears of HA and nHA users presenting signs of inflammation, were further analyzed for their antibiotic-resistance profile and characterized by the Multilocus Sequence Typing (MLST) assay. The highest rates of antibacterial resistance were in S. aureus to a penicillin (75.5%) and in P. aeruginosa, to amoxicillin-clavulanic acid, cefotaxime, ertapenem, tigecycline and trimethoprim-sulfamethoxazole (100%). Moreover, three S. aureus strains (37.5%) were methicillin-resistant (MRSA). Of the eight S. aureus isolates, we identified six sequence types (ST) indicating that 75% are likely independent clones. For what it concerned P. aeruginosa, six different STs were assigned. Interestingly, two out of the six strains presented newly identified ST values. This study sheds new light on the combined effect of the presence of HA devices and signs of external ear inflammation on the composition of the ear bacterial flora. Our results reinforce the need to practice careful hygiene of HA devices to prevent serious ear canal infections

Earth-Mars transfers through Moon distant retrograde orbits

This paper focuses on trajectory design which is relevant for missions that would follow NASA’s Asteroid Redirect Mission (ARM) to further explore and utilise asteroids and eventually human Mars exploration. Assuming that a refueling gas station is present at a given Lunar Distant Retrograde Orbit (DRO), we analyse ways of departing from the Earth to Mars via that DRO. Thus, the analysis and results presented in this paper add a new cis-lunar departure orbit for Earth-Mars missions. Porkchop plots depicting the required C3 at launch, v1 at arrival, Time of Flight (TOF), and total ∆V for various DRO departure and Mars arrival dates are created and compared with results obtained for low ∆V LEO to Mars trajectories. The results show that low ∆V DRO to Mars transfers generally have lower ∆V and TOF than LEO to Mars maneuvers