Ab initio calculation of the binding energy of impurities in semiconductors: Application to Si nanowires

We discuss the binding energy E_b of impurities in semiconductors within density functional theory (DFT) and the GW approximation, focusing on donors in nanowires as an example. We show that DFT succeeds in the calculation of E_b from the Kohn-Sham (KS) hamiltonian of the ionized impurity, but fails in the calculation of E_b from the KS hamiltonian of the neutral impurity, as it misses most of the interaction of the bound electron with the surface polarization charges of the donor. We trace this deficiency back to the lack of screened exchange in the present functionals

Testing Ultrafast Two-Photon Spectral Amplitudes via Optical Fibres

We test two-dimensional TPSA of biphoton light emitted via ultrafast spontaneous parametric down-conversion (SPDC) using the effect of group-velocity dispersion in optical fibres. Further, we apply this technique to demonstrate the engineering of biphoton spectral properties by acting on the pump pulse shape

The Court as Archive

"Until the late 20th century, ‘an archive’ generally meant a repository for documents, as well as the generic name for the wide range of documents the repository might hold. An archive could be visited, and then also searched, to discover past actions or lives that had meaning for the present. While historians and historiographers have long understood the contests that archives contain and represent, the very idea of ‘the archive’ has, over the last 40 years, become the subject and object of widening and intensified consideration. This consideration has been intellectual (from scholars in a wide range of disciplines) and public (from communities and individuals whose stories are held captive, or sometimes hidden or excluded from official archives), as well as institutional. It has involved scrutiny and critique of official archives’ limitations and practices, as well as symbolic, affective and theoretical expansion and heightened expectation of what ‘the archive’ is or should be. The very language of ‘the archive’ now carries freight as administrative practice, normative value, metaphor, description and aspiration in different ways than it did in the 20th century. This collection offers a unique contribution to these reinvigorated and sometimes new conversations about what an archive might be, what it can do as a consequence, and to whom it bears custodial responsibilities. In particular, this collection addresses what it means for contemporary Australian superior courts of record to not only have constitutional and procedural duties to documents as a matter of law, but also to acknowledge obligations to care for those materials in a way that understands their public meaning and public value for the Australian people, in the past, in the present and for the future.

Myrtucommulone from Myrtus communis exhibits potent anti-inflammatory effectiveness in vivo.

Myrtucommulone a nonprenylated acylphloroglucinol contained in the leaves of myrtle (Myrtus communis), has been reported to suppress the biosynthesis of eicosanoids by inhibition of 5-lipoxygenase and cyclooxygenase-1 in vitro and to inhibit the release of elastase and the formation of reactive oxygen species in activated polymorphonuclear leukocytes. Here, in view of the ability of MC to suppress typical proinflammatory cellular responses in vitro, we have investigated the effects of MC in in vivo models of inflammation. MC was administered to mice intraperitoneally, and paw edema and pleurisy were induced by the subplantar and intrapleural injection of carrageenan, respectively. MC (0.5, 1.5, and 4.5 mg/kg i.p.) reduced the development of mouse carrageenan-induced paw edema in a dose-dependent manner. Moreover, MC (4.5 mg/kg i.p. 30 min before and after carrageenan) exerted anti-inflammatory effects in the pleurisy model. In particular, 4 h after carrageenan injection in the pleurisy model, MC reduced: 1) the exudate volume and leukocyte numbers; 2) lung injury (histological analysis) and neutrophil infiltration (myeloperoxidase activity); 3) the lung intercellular adhesion molecule-1 and P-selectin immunohistochemical localization; 4) the cytokine levels (tumor necrosis factor-α and interleukin-1 β in the pleural exudate and their immunohistochemical localization in the lung; 5) the leukotriene B 4, but not prostaglandin E2, levels in the pleural exudates; and 6) lung peroxidation (thiobarbituric acid-reactant substance) and nitrotyrosine and poly (ADP-ribose) immunostaining. In conclusion, our results demonstrate that MC exerts potent anti-inflammatory effects in vivo and offer a novel therapeutic approach for the management of acute inflammation. Copyright © 2009 by The American Society for Pharmacology and Experimental Therapeutics

Influence of light exposure on horizontal transmission of Salmonella typhimurium in weaned pigs

The objective of the following experiment was to examine the effect of light exposure on horizontal transmission of Salmonella typhimurium in weaned pigs. Twenty crossbred pigs (average BW = 15 kg) were housed in isolation rooms (10 pigs/room) and randomly assigned to one of two lighting regimes. Low (8 h light, 16 h dark) or High (16 h light, 8 h dark). Pigs were adjusted to their respective lighting treatments for six days and on the seventh day, two randomly selected pigs/room orally inoculated with 5 ml of tryptic soy broth containing 18 x 108 cfu Salmonella typhimurium/ml. Rectal swabs were collected from each pig daily over the next eight days for direct plating and plating following 24-h enrichment. On day nine, following inoculation of the seeder pigs, all pigs were euthanized and necropsied. Luminal contents were collected from the ileum, colon, cecum and rectum (quantification and qualification of inoculated strain) and tissue samples collected from the above gut segments as well as the tonsils, ileo-cecal lymph nodes, spleen and liver (qualification only)

Roles of sorcin in drug resistance in cancer: one protein, many mechanisms, for a novel potential anticancer drug target

The development of drug resistance is one of the main causes of failure in anti-cancer treatments. Tumor cells adopt many strategies to counteract the action of chemotherapeutic agents, e.g., enhanced DNA damage repair, inactivation of apoptotic pathways, alteration of drug targets, drug inactivation, and overexpression of ABC (Adenosine triphosphate-binding cassette, or ATP-binding cassette) transporters. These are broad substrate-specificity ATP-dependent efflux pumps able to export toxins or drugs out of cells; for instance, ABCB1 (MDR1, or P-glycoprotein 1), overexpressed in most cancer cells, confers them multidrug resistance (MDR). The gene coding for sorcin (SOluble Resistance-related Calcium-binding proteIN) is highly conserved among mammals and is located in the same chromosomal locus and amplicon as the ABC transporters ABCB1 and ABCB4, both in human and rodent genomes (two variants of ABCB1, i.e., ABCB1a and ABCB1b, are in rodent amplicon). Sorcin was initially characterized as a soluble protein overexpressed in multidrug (MD) resistant cells and named “resistance-related” because of its co-amplification with ABCB1. Although for years sorcin overexpression was thought to be only a by-product of the co-amplification with ABC transporter genes, many papers have recently demonstrated that sorcin plays an important part in MDR, indicating a possible role of sorcin as an oncoprotein. The present review illustrates sorcin roles in the generation of MDR via many mechanisms and points to sorcin as a novel potential target of different anticancer molecules

Single-photon-emitting optical centers in diamond fabricated upon Sn implantation

The fabrication of luminescent defects in single-crystal diamond upon Sn implantation and annealing is reported. The relevant spectral features of the optical centers (emission peaks at 593.5 nm, 620.3 nm, 630.7 nm and 646.7 nm) are attributed to Sn-related defects through the correlation of their photoluminescence (PL) intensity with the implantation fluence. Single Sn-related defects were identified and characterized through the acquisition of their second-order auto-correlation emission functions, by means of Hanbury-Brown-Twiss interferometry. The investigation of their single-photon emission regime as a function of excitation laser power revealed that Sn-related defects are based on three-level systems with a 6 ns radiative decay lifetime. In a fraction of the studied centers, the observation of a blinking PL emission is indicative of the existence of a dark state. Furthermore, absorption dependence from the polarization of the excitation radiation with about 45 percent contrast was measured. This work shed light on the existence of a new optical center associated with a group-IV impurity in diamond, with similar photo-physical properties to the already well-known Si-V and Ge-V emitters, thus providing results of interest from both the fundamental and applicative points of view.Comment: 10 pages, 4 figure

Experimental tests of hidden variable theories from dBB to Stochastic Electrodynamics

In this paper we present some of our experimental results on testing hidden variable theories, which range from Bell inequalities measurements to a conclusive test of stochastic electrodynamics

Conditioned Unitary Transformation on biphotons

A conditioned unitary transformation ($90^o$ polarization rotation) is performed at single-photon level. The transformation is realized by rotating polarization for one of the photons of a polarization-entangled biphoton state (signal photon) by means of a Pockel's cell triggered by the detection of the other (idler) photon after polarization selection. As a result, polarization degree for the signal beam changes from zero to the value given by the idler detector quantum efficiency. This result is relevant to practical realization of various quantum information schemes and can be used for developing a new method of absolute quantum efficiency calibration