Exploring Trade-offs in Batch Bounded Distance Decoding

Algorithms for solving the Bounded Distance Decoding problem (BDD) are used for estimating the security of lattice-based cryptographic primitives, since these algorithms can be employed to solve variants of the Learning with Errors problem (LWE). In certain parameter regimes where the target vector is small and/or sparse, batches of BDD instances emerge from a combinatorial approach where several components of the target vector are guessed before decoding. In this work we explore trade-offs in solving ``Batch-BDD\u27\u27, and apply our techniques to the small-secret Learning with Errors problem. We compare our techniques to previous works which solve batches of BDD instances, such as the hybrid lattice-reduction and meet-in-the-middle attack. Our results are a mixed bag. We show that, in the ``enumeration setting\u27\u27 and with BKZ reduction, our techniques outperform a variant of the hybrid attack which does not consider time-memory trade-offs in the guessing phase for certain Round5 (17-bits out of 466), Round5-IoT (19-bits out of 240), and NTRU LPrime (23-bits out of 385) parameter sets. On the other hand, our techniques do not outperform the Hybrid Attack under standard, albeit unrealistic, assumptions. Finally, as expected, our techniques do not improve on previous works in the ``sieving setting\u27\u27 (under standard assumptions) where combinatorial attacks in general do not perform well

Estimate All the {LWE, NTRU} Schemes!

We consider all LWE- and NTRU-based encryption, key encapsulation, and digital signature schemes proposed for standardisation as part of the Post-Quantum Cryptography process run by the US National Institute of Standards and Technology (NIST). In particular, we investigate the impact that different estimates for the asymptotic runtime of (block-wise) lattice reduction have on the predicted security of these schemes. Relying on the ``LWE estimator\u27\u27 of Albrecht et al., we estimate the cost of running primal and dual lattice attacks against every LWE-based scheme, using every cost model proposed as part of a submission. Furthermore, we estimate the security of the proposed NTRU-based schemes against the primal attack under all cost models for lattice reduction

Human organotypic retinal cultures (HORCs) as a chronic experimental model for investigation of retinal ganglion cell degeneration

There is a growing need for models of human diseases that utilise native, donated human tissue in order to model disease processes and develop novel therapeutic strategies. In this paper we assessed the suitability of adult human retinal explants as a potential model of chronic retinal ganglion cell (RGC) degeneration. Our results confirmed that RGC markers commonly used in rodent studies (NeuN, bIII Tubulin and Thy-1) were appropriate for labelling human RGCs and followed the expected differential expression patterns across, as well as throughout, the macular and para-macular regions of the retina. Furthermore, we showed that neither donor age nor post-mortem time (within 24 h) significantly affected the initial expression levels of RGC markers. In addition, the feasibility of using human post mortem donor tissue as a long-term model of RGC degeneration was determined with RGC protein being detectable up to 4 weeks in culture with an associated decline in RGC mRNA and significant, progressive, apoptotic labelling of NeuNþ cells. Differences in RGC apoptosis might have been influenced by medium compositions indicating that media constituents could play a role in supporting axotomised RGCs. We propose that using ex vivo human explants may prove to be a useful model for testing the effectiveness of neuroprotective strategies

Therapeutic Benefit of Radial Optic Neurotomy in a Rat Model of Glaucoma

Radial optic neurotomy (RON) has been proposed as a surgical treatment to alleviate the neurovascular compression and to improve the venous outflow in patients with central retinal vein occlusion. Glaucoma is characterized by specific visual field defects due to the loss of retinal ganglion cells and damage to the optic nerve head (ONH). One of the clinical hallmarks of glaucomatous neuropathy is the excavation of the ONH. The aim of this work was to analyze the effect of RON in an experimental model of glaucoma in rats induced by intracameral injections of chondroitin sulfate (CS). For this purpose, Wistar rats were bilaterally injected with vehicle or CS in the eye anterior chamber, once a week, for 10 weeks. At 3 or 6 weeks of a treatment with vehicle or CS, RON was performed by a single incision in the edge of the neuro-retinal ring at the nasal hemisphere of the optic disk in one eye, while the contralateral eye was submitted to a sham procedure. Electroretinograms (ERGs) were registered under scotopic conditions and visual evoked potentials (VEPs) were registered with skull-implanted electrodes. Retinal and optic nerve morphology was examined by optical microscopy. RON did not affect the ocular hypertension induced by CS. In eyes injected with CS, a significant decrease of retinal (ERG a- and b-wave amplitude) and visual pathway (VEP N2-P2 component amplitude) function was observed, whereas RON reduced these functional alterations in hypertensive eyes. Moreover, a significant loss of cells in the ganglion cell layer, and Thy-1-, NeuN- and Brn3a- positive cells was observed in eyes injected with CS, whereas RON significantly preserved these parameters. In addition, RON preserved the optic nerve structure in eyes with chronic ocular hypertension. These results indicate that RON reduces functional and histological alterations induced by experimental chronic ocular hypertension

Formation of dense partonic matter in relativistic nucleus-nucleus collisions at RHIC: Experimental evaluation by the PHENIX collaboration

Extensive experimental data from high-energy nucleus-nucleus collisions were recorded using the PHENIX detector at the Relativistic Heavy Ion Collider (RHIC). The comprehensive set of measurements from the first three years of RHIC operation includes charged particle multiplicities, transverse energy, yield ratios and spectra of identified hadrons in a wide range of transverse momenta (p_T), elliptic flow, two-particle correlations, non-statistical fluctuations, and suppression of particle production at high p_T. The results are examined with an emphasis on implications for the formation of a new state of dense matter. We find that the state of matter created at RHIC cannot be described in terms of ordinary color neutral hadrons.Comment: 510 authors, 127 pages text, 56 figures, 1 tables, LaTeX. Submitted to Nuclear Physics A as a regular article; v3 has minor changes in response to referee comments. Plain text data tables for the points plotted in figures for this and previous PHENIX publications are (or will be) publicly available at http://www.phenix.bnl.gov/papers.htm

Placing relationships in the foreground: the role of workplace friendships in engagement

We explore the role of workplace friendships as a lens for understanding the emotional element and relational context for personal engagement (Kahn, 1990). The review of engagement theory differentiates personal engagement, recognising the role emotions play in enabling individuals’ ‘preferred selves’. Workplace relationships and friendship provide a conceptual discussion of individuals in social and workplace roles in engagement, drawing on friendship, emotion, attachment theories, particularly Kahn’s work. A case study drawn from recent research illustrates our discussion before concluding with ideas for the development of a future research agenda in answer to recent calls for work on the social context of engagement

Purification and Structural Characterization of Siderophore (Corynebactin) from Corynebacterium diphtheriae

During infection, Corynebacterium diphtheriae must compete with host iron-sequestering mechanisms for iron. C. diphtheriae can acquire iron by a siderophore-dependent iron-uptake pathway, by uptake and degradation of heme, or both. Previous studies showed that production of siderophore (corynebactin) by C. diphtheriae is repressed under high-iron growth conditions by the iron-activated diphtheria toxin repressor (DtxR) and that partially purified corynebactin fails to react in chemical assays for catecholate or hydroxamate compounds. In this study, we purified corynebactin from supernatants of low-iron cultures of the siderophore-overproducing, DtxR-negative mutant strain C. diphtheriae C7(β) ΔdtxR by sequential anion-exchange chromatography on AG1-X2 and Source 15Q resins, followed by reverse-phase high-performance liquid chromatography (RP-HPLC) on Zorbax C8 resin. The Chrome Azurol S (CAS) chemical assay for siderophores was used to detect and measure corynebactin during purification, and the biological activity of purified corynebactin was shown by its ability to promote growth and iron uptake in siderophore-deficient mutant strains of C. diphtheriae under iron-limiting conditions. Mass spectrometry and NMR analysis demonstrated that corynebactin has a novel structure, consisting of a central lysine residue linked through its α- and ε- amino groups by amide bonds to the terminal carboxyl groups of two different citrate residues. Corynebactin from C. diphtheriae is structurally related to staphyloferrin A from Staphylococcus aureus and rhizoferrin from Rhizopus microsporus in which d-ornithine or 1,4-diaminobutane, respectively, replaces the central lysine residue that is present in corynebactin

Light Meson Spectroscopy

We survey the current status of light meson spectroscopy. We begin with a general introduction to meson spectroscopy and and its importance in understanding the physical states of Quantum Chromo Dynamics (QCD). Phemenological models of hadron spectroscopy are described with particular emphasis on the constituent quark model and the qualitative features it predicts for the meson spectrum. We next discuss expectations for hadrons lying outside the quark model, such as hadron states with excited gluonic degrees of freedom. These states include so-called hybrids glueballs}, as well as multiquark states. The established meson states are compared to the quark model predictions and we find that most meson states are well described by the quark model. However, a number of states in the light-quark sector do not fit in well, suggesting the existence of hadronic states with additional degrees of freedom. We end with a brief description of future directions in meson spectroscopy.Comment: 111 pages with 28 imbedded figures, in LaTeX2e with no special macros. Submitted to Reviews of Modern Physics, Nov.12, 199

Symbols of Power: The Firearm Paintings of Madjedbebe (Malakunanja II)

Depictions of firearms in Australian Aboriginal rock art provide a unique opportunity to archaeologically explore the roles that this type of material culture played in times of culture contact. From the earliest interactions with explorers to the buffalo shooting enterprises of the twentieth century—firearms played complex and shifting roles in western Arnhem Land Aboriginal societies. The site of Madjedbebe (sometimes referred to as Malakunanja II in earlier academic literature) in Jabiluka (Mirarr Country), offers the opportunity to explore these shifting roles over time with an unprecedented 16 paintings of firearms spanning the nineteenth and twentieth centuries. This rock art provides evidence for early firearms as objects of curiosity and threat to local groups, as well as evidence for later personal ownership and use of such weaponry. Moreover, we argue that the rock art suggests increasing incorporation of firearms into traditional cultural belief and artistic systems over time with Madjedbebe playing a key role in the communication of the cultural meanings behind this new subject matter.Arts, Education & Law Group, School of Humanities, Languages and Social SciencesFull Tex