3,095 research outputs found
Survival with ambiguity
We analyze a market populated by expected utility maximizers and
smooth ambiguity-averse consumers. We study conditions under which
ambiguity-averse consumers survive and a¤ect prices in the limit. If
ambiguity vanishes with time or if the economy exhibits no aggregate
risk, ambiguity-averse consumers survive, but have no long-run impact on
prices. In both scenarios, ambiguity-averse consumers are fully insured
against ambiguity in equilibrium and, thus, behave as expected utility
maximizers with correct beliefs. If ambiguity-averse consumers are not
fully insured against ambiguity, they behave as expected utility maximiz-
ers with e¤ectively wrong beliefs and an e¤ective discount factor which
might be higher or lower than their actual discount factor. Using this in-
sight, we demonstrate that consumers with constant absolute ambiguity
aversion vanish in expectations, whenever the economy faces aggregate
risk. In contrast, consumers with constant relative (and thus, decreas-
ing absolute) ambiguity aversion survive in expectation and with positive
probability and have a non-trivial impact on prices in the limit
Behavioural patterns in social networks
In this paper, we focus on the analysis of individual decision making for the formation of social networks, using experimentally generated data. We first analyse the determinants of the individual demand for links under the assumption of agents' static expectations. The results of this exercise subsequently allow us to identify patterns of behaviour that can be subsumed in three strategies of link formation: 1) reciprocator strategy - players propose links to those from whom they have received link proposals in the previous round; 2) myopic best response strategy - players aim to profit from maximisation; 3) opportunistic strategy - players reciprocate link proposals to those who have the largest number of connections. We find that these strategies explain approximately 76% of the observed choices. We finally estimate a mixture model to highlight the proportion of the population who adopt each of these strategies
Strategies in social network formation
We run a computerised experiment of network formation where all connections are beneficial and only direct links are costly. Players simultaneously submit link proposals; a connection is made only when both players involved agree. We use both simulated and experimentally generated data to test the determinants of individual behaviour in network formation. We find that approximately 40% of the network formation strategies adopted by the experimental subjects can be accounted for as best responses. We test whether subjects follow alternative patterns of behaviour and in particular if they: propose links to those from whom they have received link proposals in the previous round; propose links to those who have the largest number of direct connections. We find that together with best response behaviour, these strategies explain approximately 75% of the observed choices. We estimate individual propensities to adopt each of these strategies, controlling for group effects. Finally we estimate a mixture model to highlight the proportion of each type of decision maker in the population
Belief heterogeneity and survival in incomplete markets
In complete markets economies (Sandroni [16]), or in economies with Pareto optimal outcomes (Blume and Easley [10]), the market selection hypothesis holds, as long as traders have identical discount factors. Traders who survive must have beliefs that merge with the truth. We show that in incomplete markets, regardless of traders’ discount factors, the market selects for a range of beliefs, at least some of which do not merge with the truth. We also show that impatient traders with incorrect beliefs can survive and that these incorrect beliefs impact prices. These beliefs may be chosen so that they are far from the truth
Measurement of the electron reconstruction efficiency at LHCb
The single electron track-reconstruction efficiency is calibrated using a sample corresponding to 1.3 fb−1 of pp collision data recorded with the LHCb detector in 2017. This measurement exploits B
+ → J/ψ(e
+
e
−
)K
+ decays, where one of the electrons is fully reconstructed
and paired with the kaon, while the other electron is reconstructed using only the information of
the vertex detector. Despite this partial reconstruction, kinematic and geometric constraints allow
the B meson mass to be reconstructed and the signal to be well separated from backgrounds. This
in turn allows the electron reconstruction efficiency to be measured by matching the partial track
segment found in the vertex detector to tracks found by LHCb’s regular reconstruction algorithms.
The agreement between data and simulation is evaluated, and corrections are derived for simulated electrons in bins of kinematics. These correction factors allow LHCb to measure branching
fractions involving single electrons with a systematic uncertainty below 1%
High granularity tracker based on a Triple-GEM optically read by a CMOS-based camera
The detection of photons produced during the avalanche development in gas
chambers has been the subject of detailed studies in the past. The great
progresses achieved in last years in the performance of micro-pattern gas
detectors on one side and of photo-sensors on the other provide the possibility
of making high granularity and very sensitive particle trackers. In this paper,
the results obtained with a triple-GEM structure read-out by a CMOS based
sensor are described. The use of an He/CF (60/40) gas mixture and a
detailed optimization of the electric fields made possible to obtain and very
high GEM light yield. About 80 photons per primary electron were detected by
the sensor resulting in a very good capability of tracking both muons from
cosmic rays and electrons from natural radioactivity
Isoflavones and other compounds from the roots of Iris marsica I. Ricci E Colas. Collected from Majella National Park, Italy
In this study, a phytochemical analysis was performed, for the first time, on Iris marsica I. Ricci e Colas. In particular, the attention was focused on the constituents of the roots. Twenty-one compounds were isolated by column chromatography and were analyzed/identified by NMR spectroscopy and mass spectrometry. They all own chemotaxonomic, ethno-pharmacological and nutraceutical relevance which allowed us to provide a phytochemical rationale, for the correct botanical classification of this species, for the employment of its roots in folk medicine like for all the other species belonging to the Iris genus and, lastly, for their further uses as food with important healthy benefits. All of these parts were broadly discussed about within the text
A Systematic Review of the Current Role of Minimally Invasive Spine Surgery in the Management of Metastatic Spine Disease
Although increasingly aggressive decompression and resection methods have resulted in improved outcomes for patients with metastatic spine disease, these aggressive surgeries are not feasible for patients with numerous comorbid conditions. Such patients stand to benefit from management via minimally invasive spine surgery (MIS), given its association with decreased perioperative morbidity. We performed a systematic review of literature with the goal of evaluating the clinical efficacy and safety of MIS in the setting of metastatic spine disease. Results suggest that MIS is an efficacious means of achieving neurological improvement and alleviating pain. In addition, data suggests that MIS offers decreased blood loss, operative time, and complication rates in comparison to standard open spine surgery. However, due to the paucity of studies and low class of available evidence, the ability to draw comprehensive conclusions is limited. Future investigations should be conducted comparing standard surgery versus MIS in a prospective fashion
Characterisation of the secondary-neutron production in particle therapy treatments with the MONDO tracking detector
Particle Therapy (PT) is a non-invasive technique that exploits charged light ions for the irradiation of tumours that cannot be effectively treated with surgery or conventional radiotherapy. While the largest dose fraction is released to the tumour volume by the primary beam, a non-negligible amount of additional dose is due to the beam fragmentation that occurs along the path towards the target volume. In particular, the produced neutrons are particularly dangerous as they can release their energy far away from the treated area, increasing the risk of developing a radiogenic secondary malignant neoplasm after undergoing a treatment. A precise measurement of the neutron flux, energy spectrum and angular distributions is eagerly needed in order to improve the treatment planning system software, so as to predict the normal tissue toxicity in the target region and the risk of late complications in the whole body. The MONDO (MOnitor for Neutron Dose in hadrOntherapy) project is dedicated to the characterisation of the secondary ultra-fast neutrons ([20-400] MeV energy range) produced in PT. The neutron tracking system exploits the reconstruction of the recoil protons produced in two consecutive (n, p) elastic scattering interactions to measure simultaneously the neutron incoming direction and energy. The tracker active media is a matrix of thin squared scintillating fibers arranged in orthogonally oriented layers that are read out by a sensor (SBAM) based on SPAD (Single-Photon Avalanche Diode) detectors developed in collaboration with the Fondazione Bruno Kessler (FBK)
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