Income taxes, subsidies to education, and investments in human capital

We study a two-sector economy with investments in human and physical capital and imperfect labor markets. Human and physical capital are heterogeneous. Workers and firms endogenously select the sector they are active in, and choose the amount of their sector-specific investments in human and physical capital. To enter the high-skill sector, workers must pay a fixed cost that we interpret as direct cost of education. Given the distribution of the agents across sectors, at equilibrium, in each sector there is underinvestment in both human and physical capital, due to non-contractibility of investments. A second source of inefficiency is related to the self-selection of the agents into the two sectors. It typically induces too many workers to invest in education. Under suitable restrictions on the parameters, the joint effect of the two distortions is that equilibria are characterized by too many people investing too little effort in the high skill sector. We also analyze the welfare properties of equilibria and study the effects of several tax-subsidy policies on the total expected surplus.

Investments in education and welfare in a two-sector, random matching economy

We consider a random matching model where heterogeneous agents choose optimally to invest time and real resources in education. Generically, there is a steady state equilibrium, where some agents, but not all of them, invest. Regular steady state equilibria are constrained inefficient in a strong sense. The Hosios (1990) condition is neither necessary, nor sufficient, for constrained efficiency. We also provide restrictions on the fundamentals sufficient to guarantee that equilibria are characterized by overeducation (or undereducation), present some results on their comparative statics properties, and discuss the nature of welfare improving policies.

Long-Range Order in Electronic Transport through Disordered Metal Films

Ultracold atom magnetic field microscopy enables the probing of current flow patterns in planar structures with unprecedented sensitivity. In polycrystalline metal (gold) films we observe long-range correlations forming organized patterns oriented at +/- 45 deg relative to the mean current flow, even at room temperature and at length scales orders of magnitude larger than the diffusion length or the grain size. The preference to form patterns at these angles is a direct consequence of universal scattering properties at defects. The observed amplitude of the current direction fluctuations scales inversely to that expected from the relative thickness variations, the grain size and the defect concentration, all determined independently by standard methods. This indicates that ultracold atom magnetometry enables new insight into the interplay between disorder and transport

Ethyl 6-Bromo-3indolcarboxylate and 3-Hydroxyacetal-6-bromoindole, novel bromoindoles from the sponge Pleroma menoui of the Coral Sea

L'éponge #Plemora menoui (Démosponge, #O. Lithistida, ss. #O. Trienosina, #Desmophorina, Fam. #Pleromidae$) récoltée à une profondeur de 500 m dans la Mer de Corail, au sud-est de Nouméa contient deux nouveaux alcaloïdes : ethyl 6-bromo-3-indolcarboxylate and 3-hydroxyacétal-6-bromoindole. (Résumé d'auteur

MULTI-SOURCE 3D MODELS SUPPORTING ULTRASONIC TEST TO INVESTIGATE AN EGYPTIAN SCULPTURE OF THE ARCHAEOLOGICAL MUSEUM IN BOLOGNA

The paper presents the workflow and the results of an ultrasonic 3D investigation and a 3D survey application aimed at the assessment of the internal integrity of an ancient sculpture. The work aimed at highlighting the ability of methods devoted to the 3D geometry acquisition of small objects when applied to diagnosis performed by geophysical investigation. In particular, two methods widely applied for small objects modelling are considered and compared, the digital Photogrammetry with the Structure from Motion (SFM) technique and hand-held 3D scanners. The study concludes with the aim to enhance the final graphical representation of the tomographic results and to subject the obtained results to a quantitative analysis. The survey is applied to the Egyptian naophorous statue of Amenmes and Reshpu, which dates to the reign of Ramses II (1279-1213 BC) or later and is now preserved in the Civic Archaeological Museum in Bologna. In order to evaluate the internal persistency of fractures and visible damages, a 3D Ultrasonic Tomographic Imaging (UTI) test has been performed and a multi-sensor survey (image and range based) was conducted, in order to evaluate the locations of the source and receiver points as accurate as possible The presented test allowed to evaluate the material characteristics, its porosity and degradation state, which particularly affect the lower part of the statue. More in general, the project demonstrated how solution coming from the field of 3D modelling of Cultural Heritage allow the application of 3D ultrasonic tomography also on objects with complex shapes, in addition to the improved representation of the obtained results

Does LigaSure™ reduce fluid drainage in axillary dissection? A randomized prospective clinical trial

Background: Axillary lymph node dissection (ALND) is an integral part of breast cancer treatment. It is required in about 40\u201350% of patients. The placement of a drain in the axilla after an operation is current surgical practice. Short surgical stay programmes increase operating efficiency and reduce medical care costs, without compromising quality of care. LigaSureTM is a new haemostatic device that uses bipolar energy to seal vessels. The aim of this study is to determine whether axillary dissection with LigaSureTM reduces the time of wound drainage, the duration of surgical intervention and the volume of drainage after treatment. Patients and methods: This study is a prospective randomized controlled trial. A total of 100 women with breast cancer who needed axillary dissection were randomized into the LigaSureTM or conventional axillary dissection group. Levels I to III lymph node dissection was performed. A closed suction drain was always placed in the axilla and removed after 6\u20138 days or when fluid amount was <60 cc in the previous 24 hours. Results: There were no significant differences between the two groups when considering the duration of surgical procedure: average duration was 70.7 \ub1 24.66 minutes for LigaSureTM patients, while in the conventional dissection group the mean was 70.6 \ub1 22.47 minutes (p=0.98). Total amount of drained fluid was 624.49 cc in the LigaSureTM axillary dissection group and 792.96 in the conventional ALND group; this difference did not achieve statistical significance (p=0.09); the duration of draining was also similar, with no statistical difference (p=0.15). Conclusions: The present study did not show clear advantages in LigaSureTM use for ALND, although it represents a good haemostatic device, especially in abdominal surgery. Subject: Breas

The IBMAP approach for Markov networks structure learning

In this work we consider the problem of learning the structure of Markov networks from data. We present an approach for tackling this problem called IBMAP, together with an efficient instantiation of the approach: the IBMAP-HC algorithm, designed for avoiding important limitations of existing independence-based algorithms. These algorithms proceed by performing statistical independence tests on data, trusting completely the outcome of each test. In practice tests may be incorrect, resulting in potential cascading errors and the consequent reduction in the quality of the structures learned. IBMAP contemplates this uncertainty in the outcome of the tests through a probabilistic maximum-a-posteriori approach. The approach is instantiated in the IBMAP-HC algorithm, a structure selection strategy that performs a polynomial heuristic local search in the space of possible structures. We present an extensive empirical evaluation on synthetic and real data, showing that our algorithm outperforms significantly the current independence-based algorithms, in terms of data efficiency and quality of learned structures, with equivalent computational complexities. We also show the performance of IBMAP-HC in a real-world application of knowledge discovery: EDAs, which are evolutionary algorithms that use structure learning on each generation for modeling the distribution of populations. The experiments show that when IBMAP-HC is used to learn the structure, EDAs improve the convergence to the optimum

Upper bounds for the eigenvalues of Hessian equations

We prove some upper bounds for the Dirichlet eigenvalues of a class of fully nonlinear elliptic equations, namely the Hessian equationsComment: 15 pages, 1 figur

The in vivo effect of chelidonine on the stem cell system of planarians

The presence of adult pluripotent stem cells and the amazing regenerative capabilities make planarian flatworms an extraordinary experimental model to assess in vivo the effects of substances of both natural and synthetic origin on stem cell dynamics. This study focuses on the effects of chelidonine, an alkaloid obtained from Chelidonium majus. The expression levels of molecular markers specific for stem or differentiated cells were compared in chelidonine-treated and control planarians. The use of these markers demonstrates that chelidonine produces in vivo a significant anti-proliferative effect on planarian stem cells in a dosedependent fashion. In response to chelidonine treatment mitotic abnormalities were also observed and the number of cells able to proceed to anaphase/telophase appeared significantly reduced with respect to the controls. Our results support the possibility that chelidonine acts on cell cycle progression by inhibition of tubulin polymerization. These studies provide a basis for preclinical evaluation in vivo of the effects of chelidonine on physiologically proliferating stem cells

GNAM and OHP: Monitoring Tools for ATLAS experiment at LHC.

ATLAS is one of the four experiments under construction along the Large Hadron Collider (LHC) ring at CERN. The LHC will produce interactions at a center-of-mass energy equal to âs = 14 TeV at 40 MHz rate. The detector consists of more than 140 million electronic channels. The challenging experimental environment and the extreme detector complexity impose the necessity of a common scalable distributed monitoring framework, which can be tuned for the optimal use by different ATLAS sub-detectors at the various levels of the ATLAS data flow. This note presents two monitoring tools that have been developed for this aim within the architecture ATLAS Monitoring Framework and the Data Acquisition System: GNAM and OHP. The first one is a framework for online histogram production; the second one is graphical application for histogram presentation. This tools are now widely used during the ATLAS commissioning and their performances are reported in this not