Time-dependent Maxwell field operators and field energy density for an atom near a conducting wall

We consider the time evolution of the electric and magnetic field operators for a two-level atom, interacting with the electromagnetic field, placed near an infinite perfectly conducting wall. We solve iteratively the Heisenberg equations for the field operators and obtain the electric and magnetic energy density operators around the atom (valid for any initial state). Then we explicitly evaluate them for an initial state with the atom in its bare ground state and the field in the vacuum state. We show that the results can be physically interpreted as the superposition of the fields propagating directly from the atom and the fields reflected on the wall. Relativistic causality in the field propagation is discussed. Finally we apply these results to the calculation of the dynamical Casimir-Polder interaction energy in the far zone between two atoms when a boundary condition such as a conducting wall is present. Magnetic contributions to the interatomic Casimir-Polder interaction in the presence of the wall are also considered. We show that, in the limit of large times, the known results of the stationary case are recovered.Comment: 11 page

Amaurodon mustialaënsis (Basidiomycota, Thelephoraceae) new to Italy

Amaurodon mustialaënsis is reported for the first time from Italy. Based on Italian specimens, a brief description, microscopical and macroscopical photographs, ecological and distributional data of this rare taxon are presented.

Atomic states in optical traps near a planar surface

In this work we discuss the atomic states in a vertical optical lattice in proximity of a surface. We study the modifications to the ordinary Wannier-Stark states in presence of a surface and we characterize the energy shifts produced by the Casimir-Polder interaction between atom and mirror. In this context, we introduce an effective model describing the finite size of the atom in order to regularize the energy corrections. In addition, the modifications to the energy levels due to a hypothetical non-Newtonian gravitational potential as well as their experimental observability are investigated.Comment: 12 pages, 8 figure

Inactivation of the PRDM1/BLIMP1 gene in diffuse large B cell lymphoma

PR domain containing 1 with zinc finger domain (PRDM1)/B lymphocyte–induced maturation protein 1 (BLIMP1) is a transcriptional repressor expressed in a subset of germinal center (GC) B cells and in all plasma cells, and required for terminal B cell differentiation. The BLIMP1 locus lies on chromosome 6q21-q22.1, a region frequently deleted in B cell lymphomas, suggesting that it may harbor a tumor suppressor gene. We report here that the BLIMP1 gene is inactivated by structural alterations in 24% (8 out of 34) activated B cell–like diffuse large cell lymphoma (ABC-DLBCL), but not in GC B cell–like (n = 0/37) or unclassified (n = 0/21) DLBCL. BLIMP1 alterations included gene truncations, nonsense mutations, frameshift deletions, and splice site mutations that generate aberrant transcripts encoding truncated BLIMP1 proteins. In all cases studied, both BLIMP1 alleles were inactivated by deletions or mutations. Furthermore, most non–GC type DLBCL cases (n = 20/26, 77%) lack BLIMP1 protein expression, despite the presence of BLIMP1 mRNA. These results indicate that a sizable fraction of ABC-DLBCL carry an inactive BLIMP1 gene, and suggest that the same gene is inactivated by epigenetic mechanisms in an additional large number of cases. These findings point to a role for BLIMP1 as a tumor suppressor gene, whose inactivation may contribute to lymphomagenesis by blocking post–GC differentiation of B cells toward plasma cells

First records of Craterium aureonucleatum, Perichaena quadrata, and Physarum mutabile in Italy

Three species of Mycetozoa, new for Italy, were identified in garrigues and maquis ecosystems on the volcanic island of Pantelleria (Sicily). The finding of Craterium aureonucleatum, Perichaena quadrata, and Physarum mutabile widens their distribution in Europe and identifies new substrata

GATE and FENCE: Geo-Blocking Protocols for Named Data Networking

Named Data Networking (NDN) is a novel Internet architecture which focuses on content distribution by exploiting in-network caching and name-based forwarding. Contrary to today’s Internet, NDN has been designed from the ground up to be secure. From a content provider perspective (e.g., YouTube, Netflix), NDN offers appealing advantages in terms of network load and traffic reduction at producer side through in-network requests aggregation and content caching. As a side effect, content providers lose control on content dissemination when consumers’ requests are aggregated or satisfied by the network. This hinders the correct application of copyright and licensing agreements: only specific regions are allowed to consume a subset of the distributed contents. In attempt to address this problem, the existing TCP/IP approaches exploit requests’ source addresses (at server side) to identify the geographic origin of each request. In NDN these solutions are unfeasible for two reasons: consumers’ requests do not carry any source address, and a request will never reach content providers when aggregated or satisfied in the network. We solve this problem by proposing two lightweight and distributed geo-blocking protocols (GATE and FENCE) which use packet marking to identify and validate network regions at network edges. We perform experiments both on a network simulator and by extending the NDN implementation. Through our results we prove the proposed protocols are feasible, i.e., all the regions blacklisted by content providers are blocked and their network costs, in terms of space and router processing overhead, are negligible

Australohydnum dregeanum new to Italy

We report on the first finding in Italy (and the third in Europe) of Australohydnum dregeanum. A detailed description of the macro- and micromorphological features, the ecological data, and some taxonomic remarks concerning this taxon are provided. The bluish tint in the centre of the hymenophoral surface and the non-cystidiform aspect of the marginal hyphae are previously undescribed characters

Rituximab in refractory sarcoidosis: a single centre experience

Sarcoidosis is a granulomatous disease whose outcome varies from spontaneous remission to chronic refractory disease. Provided that steroids represent the gold standard as a first line treatment, many immune suppressants drugs are currently used in the disease management. However, refractory disease is still a great challenge. Rituximab is an anti-CD20 chimeric monoclonal antibody, currently used for the treatment of B cell malignancies and systemic autoimmune diseases. There are few case reports describing the successful use of Rituximab in refractory sarcoidosis with lung, eye, lymph nodes and skin involvement. In this paper we described three different case reports in which Rituximab has been used to treat refractory sarcoidosis and we reviewed the existing literature

A contribution to the knowledge of myxomycetes diversity in volcanic islands

A list of myxomycetes collected in Pantelleria, a volcanic island located 110km southwest of the island of Sicily (Italy), is presented with data on distribution. Forty-nine taxa were identified, 38 of which are new for Sicily. The myxomycete diversity of Pantelleria was also compared with that of other volcanic islands located in the Atlantic and Pacific oceans