Unbroken supersymmetry in the Aharonov-Casher effect

We consider the problem of the bound states of a spin 1/2 chargless particle in a given Aharonov-Casher configuration. To this end we recast the description of the system in a supersymmetric form. Then the basic physical requirements for unbroken supersymmetry are established. We comment on the possibility of neutron confinement in this system

Improving Link Specifications using Context-Aware Information

There is an increasing interest in publishing data using the Linked Open Data philosophy. To link the RDF datasets, a link discovery task is performed to generate owl:sameAs links. There are two ways to perform this task: by means of a classi er or a link speci cation; we focus in the latter approach. Current link speci cation techniques only use the data properties of the instances that they are linking, and they do not take the context information into account. In this paper, we present a proposal that aims to generate context-aware link speci cations to improve the regular link speci cations, increasing the e ectiveness of the results in several real-world scenarios where the context is crucial. Our context-aware link speci cations are independent from similarity functions, transformations or aggregations. We have evaluated our proposal using two real-world scenarios in which we improve precision and recall with respect to regular link speci cations in 23% and 58%, respectively.Ministerio de Economía y Competitividad TIN2013-40848-

Neutron Acceleration in Uniform Electromagnetic Fields

The question as to whether neutron acceleration can occur in uniform electromagnetic fields is examined. Although such an effect has been predicted using the canonical equations of motion some doubt has been raised recently as to whether it is in principle observable for a spin 1/2 particle. To resolve this issue a gedanken experiment is proposed and analyzed using a wave packet construction for the neutron beam. By allowing arbitrary orientation for the neutron spin as well as for the electric and magnetic fields a non vanishing acceleration of the center of the neutron wave packet is found which confirms the predictions of the canonical formalism.Comment: 11 page

Herbicidal potential of ophiobolins produced by Drechslera gigantea

Drechslera gigantea, a potential mycoherbicide of grass weeds, was isolated in Florida from naturally infected large crabgrass (Digitaria sanguinalis); it produces phytotoxic metabolites in liquid culture. The main metabolite was identified by spectroscopic methods and optical properties as ophiobolin A (1), a well-known phytotoxic sesterterpene produced by several phytopathogenic fungi of important crops and already extensively studied for its interesting biological activities. The other three minor metabolites proved to be related to ophiobolin A and were identified using the same techniques as 6-epi-ophiobolin A and 3-anhydro-6-epi-ophiobolin A (2 and 3) and ophiobolin I (4). Assayed on punctured detached leaves of several grass and dicotyledon weeds, ophiobolin A proved to be on average more phytotoxic as compared to the other related compounds. Some structural features appear to be important for the phytoxicity, such as the hydroxy group at C-3, the stereochemistry at C-6, and the aldehyde group at C-7. Furthermore, grass weeds usually proved to be more sensitive to the phytotoxins than dicotyledons, on which ophiobolin A caused the appearance of large necrosis even at the lowest concentration assayed. This is the first report about the production of ophiobolins from D. gigantea and of the proposed use as potential natural herbicides against grass weeds. © 2006 American Chemical Society

Ophiobolin E and 8-epi-ophiobolin J produced by Drechslera gigantea, a potential mycoherbicide of weedy grasses

Drechslera gigantea, a fungal pathogen isolated from large crabgrass (Digitaria sanguinalis) and proposed as a potential mycoherbicide of grass weeds, produces phytotoxic metabolites in liquid and solid cultures. Ophiobolin A and three minor ophiobolins i.e., 6-epi-ophiobolin A, 3-anhydro-6-epi-ophiobolin A and ophiobolin I were obtained from the liquid culture broths. Interestingly and unexpectedly, ophiobolins also appeared in cultures of this fungus and they were isolated together with the known ophiobolins B and J, and designed as ophiobolin E and 8-epi-ophiobolin J. They were characterized using essentially spectroscopic methods. It is noteworthy that D. gigantea produces such a plethora of bioactive organic substances. Some structure-activity relationship results are also discussed in this report. © 2006 Elsevier Ltd. All rights reserved

Multimodality imaging of chronic tophaceous gout

The diagnosis of gout is usually based on clinical presentation and laboratory findings. Imaging plays a role in the assessment and grading of articular damage related to chronic, long-standing disease, which is characterized by granulomatous synovitis, tophi, and erosions. Multimodality imaging of chronic tophaceous gout may be useful in clinical practice for a variety of purposes, including assessment of disease-related anatomical changes and monitoring of articular and soft-tissue lesions over time, especially in response to urate-lowering therapy. Radiography remains the primary imaging technique. Ultrasonography may detect monosodium urate crystals on cartilage, is helpful to assess small joint effusion, to guide to joint aspiration, and to evaluate the volume of tophi. Computed tomography is considered to be more sensitive than plain radiography in the detection and evaluation of cortical bone erosions associated with tophi. MRI represents the only imaging modality which provides visualization of bone marrow oedema associated with erosions and may be useful to characterize and distinguish tophi from other soft tissue nodules

Stand-alone Low Power Consumption FEE and DAQ for the Readout of Silicon Photomultipliers

We developed a front end electronics (FEE) and data acquisition (DAQ) system with a low power consumption, especially intended for stand-alone applications in unattended environments without standard electricity supply. The system works autonomously thanks to dedicated algorithms that are embedded. The FEE is based on the EASIROC chip, designed for the readout of Silicon photomultipliers (SiPMs). It digitizes the amplitude of the signals and provides time information with time of flight capability. The trigger logic is programmable and physical and accidental coincidences rates can be measured. The SiPMs temperature is controlled by thermoelectric cells. Thanks to a network of temperature and humidity sensors, a real-time software sets the optimal operating point of the SiPMs depending on external conditions and if necessary halts the system to avoid damage to the electronics. The system has been used in several muon radiography experiments

Bound states of neutral particles in external electric fields

Neutral fermions of spin $\frac 12$ with magnetic moment can interact with electromagnetic fields through nonminimal coupling. The Dirac--Pauli equation for such a fermion coupled to a spherically symmetric or central electric field can be reduced to two simultaneous ordinary differential equations by separation of variables in spherical coordinates. For a wide variety of central electric fields, bound-state solutions of critical energy values can be found analytically. The degeneracy of these energy levels turns out to be numerably infinite. This reveals the possibility of condensing infinitely many fermions into a single energy level. For radially constant and radially linear electric fields, the system of ordinary differential equations can be completely solved, and all bound-state solutions are obtained in closed forms. The radially constant field supports scattering solutions as well. For radially linear fields, more energy levels (in addition to the critical one) are infinitely degenerate. The simultaneous presence of central magnetic and electric fields is discussed.Comment: REVTeX, 14 pages, no figur

Topological phase due to electric dipole moment and magnetic monopole interaction

We show that there is an anologous Aharonov-Casher effect on a neutral particle with electric dipole moment interacting with a magnetic filed produced by magnetic monopoles.Comment: 8 page

Reumatismo : cambio della guardia

Cosa significa prendere nelle mani la direzione di una delle pi\uf9 antiche riviste di reumatologia al mondo? Un ritorno al passato ed un tuffo nel futuro: nel passato ritrovo il ricordo di uno specializzando in reumatologia alle prime armi coinvolto nella redazione di Reumatismo, diretta allora dal Prof. Vittorio Bianchi. Nel futuro alcune idee e progetti ambiziosi per rendere la nostra rivista sempre pi\uf9 incisiva nel mondo della reumatologia. Questi sono stati suggeriti e discussi con i due codirettori Roberto Caporali e Piercarlo Sarzi-Puttini: sapere che loro facevano parte del team ha reso di molto pi\uf9 facile la decisione di accettare questo incarico, del quale sono, ovviamente, onorato. Il momento \ue8 senza dubbio propizio ed entusiasmante: la reumatologia italiana sta confermando il suo ruolo in Europa (EULAR 2010 a Roma, primato nella partecipazione scientifica dei reumatologi italiani ai congressi europei, pubblicazioni internazionali, presidenze di commissioni, ecc.) e questo non potr\ue0 non avere ricadute anche su Reumatismo