Time-Area Optimized Public-Key Engines: MQ-Cryptosystems as Replacement for Elliptic Curves?

In this paper ways to efficiently implement public-key schemes based onMultivariate Quadratic polynomials (MQ-schemes for short) are investigated. In particular, they are claimed to resist quantum computer attacks. It is shown that such schemes can have a much better time-area product than elliptic curve cryptosystems. For instance, an optimised FPGA implementation of amended TTS is estimated to be over 50 times more efficient with respect to this parameter. Moreover, a general framework for implementing small-field MQ-schemes in hardware is proposed which includes a systolic architecture performing Gaussian elimination over composite binary fields

Spatial matter density mapping of the STAGES Abell A901/2 supercluster field with 3D lensing

We present weak lensing data from the Hubble Space Telescope(HST)/Space Telescope A901/902 Galaxy Evolution Survey (STAGES) survey to study the three-dimensional spatial distribution of matter and galaxies in the Abell 901/902 supercluster complex. Our method improves over the existing 3D lensing mapping techniques by calibrating and removing redshift bias and accounting for the effects of the radial elongation of 3D structures. We also include the first detailed noise analysis of a 3D lensing map, showing that even with deep HST-quality data, only the most massive structures, for example M200≳ 1015M⊙h-1 at z∼ 0.8, can be resolved in 3D with any reasonable redshift accuracy (Δz≈ 0.15). We compare the lensing map to the stellar mass distribution and find luminous counterparts for all mass peaks detected with a peak significance >3σ. We see structures in and behind the z= 0.165 foreground supercluster, finding structure directly behind the A901b cluster at z∼ 0.6 and also behind the south-west (SW) group at z∼ 0.7. This 3D structure viewed in projection has no significant impact on recent mass estimates of A901b or the SW group components SWa and SWb. © 2011 The Authors Monthly Notices of the Royal Astronomical Society © 2011 RAS

Is the meta-analysis of correlation coefficients accurate when population correlations vary?

One conceptualization of meta-analysis is that studies within the meta-analysis are sampled from populations with mean effect sizes that vary (random-effects models). The consequences of not applying such models and the comparison of different methods have been hotly debated. A Monte Carlo study compared the efficacy of Hedges and Vevea's random-effects methods of meta-analysis with Hunter and Schmidt's, over a wide range of conditions, as the variability in population correlations increases. (a) The Hunter-Schmidt method produced estimates of the average correlation with the least error, although estimates from both methods were very accurate; (b) confidence intervals from Hunter and Schmidt's method were always slightly too narrow but became more accurate than those from Hedges and Vevea's method as the number of studies included in the meta-analysis, the size of the true correlation, and the variability of correlations increased; and (c) the study weights did not explain the differences between the methods

Combination of short-read, long-read, and optical mapping assemblies reveals large-scale tandem repeat arrays with population genetic implications

Accurate and contiguous genome assembly is key to a comprehensive understanding of the processes shaping genomic diversity and evolution. Yet, it is frequently constrained by constitutive heterochromatin, usually characterized by highly repetitive DNA. As a key feature of genome architecture associated with centromeric and subtelomeric regions, it locally influences meiotic recombination. In this study, we assess the impact of large tandem repeat arrays on the recombination rate landscape in an avian speciation model, the Eurasian crow. We assembled two high-quality genome references using single-molecule real-time sequencing (long-read assembly [LR]) and single-molecule optical maps (optical map assembly [OM]). A three-way comparison including the published short-read assembly (SR) constructed for the same individual allowed assessing assembly properties and pinpointing misassemblies. By combining information from all three assemblies, we characterized 36 previously unidentified large repetitive regions in the proximity of sequence assembly breakpoints, the majority of which contained complex arrays of a 14-kb satellite repeat or its 1.2-kb subunit. Using whole-genome population resequencing data, we estimated the population-scaled recombination rate (ρ) and found it to be significantly reduced in these regions. These findings are consistent with an effect of low recombination in regions adjacent to centromeric or subtelomeric heterochromatin and add to our understanding of the processes generating widespread heterogeneity in genetic diversity and differentiation along the genome. By combining three different technologies, our results highlight the importance of adding a layer of information on genome structure that is inaccessible to each approach independently

Persönlichkeit und Entspannung vs. Ablenkung beim Zahnarzt

Die vorliegende Studie untersuchte den Einfluß von hoch und niedrig ausgeprägter Zahnbehandlungsangst und den Einfluß der Intervention durch ein Entspannungs- und Ablenkungsverfahren (und Kontrolle) bei der Antizipation einer Zahnbehandlung. Die Teilnehmer waren 49 Patienten einer Giessener Zahnarztpraxis, die parallelisiert nach Alter und Geschlecht auf die Bedingungen aufgeteilt wurden. Anders als in anderen Studien wurden die verschiedenen Meßaspekte in umfassender Weise betrachtet: es wurden peripher-physiologische, immunologische, subjektiv-verbale und behaviorale Indikatoren herangezogen. Außerdem wurde der Einfluß der Ausprägung der Zahnbehandlungsangst und der Art der Experimentalbedingung auf das aktuelle Coping-verhalten untersucht. Es zeigte sich, dass peripher-physiologische und immunologische Indikatoren nicht von der Ausprägung der Zahnbehandlungsangst beeinflußt waren. Allerdings zeigten sich subjektiv-verbale Unterschiede: Hochängstliche schätzten ihre körperliche Erregung höher ein als Niedrigängstliche, was auf eine Tendenz der Hochängstlichen zurückgeführt wurde, körperliche Reaktionen stärker als Niedrigängstliche zu beachten. Weiterhin zeigten sich behaviorale Unterschiede: Hochängstliche wirkten starrer und wurden als ängstlicher, weniger entspannt und weniger kooperativ eingeschätzt. Allerdings hat sich das aktuelle Copingverhalten von Hoch- und Niedrigängstlichen nicht unterschieden. Die Ergebnisse sprechen jedoch für eine Wirksamkeit des Entspannungsverfahrens, vor allem bei Hochängstlichen. Zwar haben sich die Experimentalgruppen, wie auch die Persönlichkeitsgruppen, nicht in peripher-physiologischen und immunologischen Indikatoren unterschieden, allerdings verbesserte das Entspannungsverfahren die subjektive Befindlichkeit besonders bei den Hochängstlichen. Auch behaviorale Unterschiede weisen auf die Wirksamkeit des Entspannungsverfahrens hin, dass sich von der Wirkung des Ablenkungsverfahrens und der Kontrollbedingung unterscheidet. Die Ergebnisse zur Wirksamkeit des Ablenkungsverfahrens sind weniger eindeutig. Das Ablenkungsverfahren unterscheidet sich in einigen Punkten vom Entspannungsverfahren, allerdings kaum von der Kontrollbedingung. Dies wird der verwendeten Technik (Audio-Präsentation) angelastet, die vergleichsweise wenig Ablenkungskraft hat. Allerdings beeinflußte das Ablenkungsverfahren das aktuelle Copingverhalten während der Zahnbehandlung

Patients' use of a home-based virtual reality system to provide rehabilitation of the upper limb following stroke

Background: A low cost, virtual reality system that translates movements of the hand, fingers and thumb into game play was designed to provide a flexible and motivating approach to increasing adherence to home based rehabilitation. Objective: Effectiveness depends on adherence, so did patients use the intervention to the recommended level. If not, what reasons did they give? Design: Prospective cohort study plus qualitative analysis of interviews. Methods: 17 patients recovering from stroke recruited to the intervention arm of a feasibility trial had the equipment left in their homes for eight weeks and were advised to use it three times a day for periods of no more than 20 minutes. Frequency and duration of use were automatically recorded. At the end of the intervention, participants were interviewed to determine barriers to using it in the recommended way. Results: Duration of use and how many days they used the equipment are presented for the 13 participants who successfully started the intervention. These figures were highly variable and could fall far short of our recommendations. There was a weak (p=0.053) positive correlation between duration and baseline reported activities of daily living. Participants reported familiarity with technology and competing commitments as barriers to use although appreciated the flexibility of the intervention and found it motivating

Positives and negatives: reclaiming the female body and self-deprecation in stand-up comedy

Drawing on existing research into feminist humour, this article argues that many of the functions of self-deprecation within comic performance that have been identified and explored in relation to the American context of the late 90s and early 2000s are still evident on the current UK circuit. Self-deprecation in stand-up comedy by women continues to be understood as both positive (as part of the rise of popular feminisms) and negative (as reinforcing patriarchal norms). These contradictory understandings of self-deprecation in stand-up comedy are always inextricably linked to the identities of the audiences for such humour. I consider how emergent female stand-up performers may rationalise and understand the role self-deprecation plays within their own work in the current British context. I then discuss the work of stand-up comedian Luisa Omielan as an example of the rejection of self-deprecatory address. I make the argument that self-deprecation cannot function simply as positive or negative in the current UK context, but must always be considered (for both audiences and performers) as challenging and reinforcing restrictive patriarchal attitudes towards women simultaneously

The STAGES view of red spirals and dusty red galaxies: Mass-dependent quenching of star-formation in cluster infall

We investigate the properties of optically passive spirals and dusty red galaxies in the A901/2 cluster complex at redshift ~0.17 using restframe near-UV-optical SEDs, 24 micron IR data and HST morphologies from the STAGES dataset. The cluster sample is based on COMBO-17 redshifts with an rms precision of sigma_cz~2000 km/sec. We find that 'dusty red galaxies' and 'optically passive spirals' in A901/2 are largely the same phenomenon, and that they form stars at a substantial rate, which is only 4x lower than that in blue spirals at fixed mass. This star formation is more obscured than in blue galaxies and its optical signatures are weak. They appear predominantly in the stellar mass range of log M*/Msol=[10,11] where they constitute over half of the star-forming galaxies in the cluster; they are thus a vital ingredient for understanding the overall picture of star formation quenching in clusters. We find that the mean specific SFR of star-forming galaxies in the cluster is clearly lower than in the field, in contrast to the specific SFR properties of blue galaxies alone, which appear similar in cluster and field. Such a rich red spiral population is best explained if quenching is a slow process and morphological transformation is delayed even more. At log M*/Msol<10, such galaxies are rare, suggesting that their quenching is fast and accompanied by morphological change. We note, that edge-on spirals play a minor role; despite being dust-reddened they form only a small fraction of spirals independent of environment.Comment: Accepted for publication in MNRA

Optically-passive spirals: The missing link in gradual star formation suppression upon cluster infall

Galaxies migrate from the blue cloud to the red sequence when their star formation is quenched. Here, we report on galaxies quenched by environmental effects and not by mergers or strong AGN as often invoked: They form stars at a reduced rate which is optically even less conspicuous, and manifest a transition population of blue spirals evolving into S0 galaxies. These 'optically passive' or 'red spirals' are found in large numbers in the STAGES project (and by Galaxy Zoo) in the infall region of clusters and groups.Comment: Proceedings of "The Starburst-AGN connection" conference held in Shanghai, Oct 27-31, 200

STAGES: the Space Telescope A901/2 Galaxy Evolution Survey

We present an overview of the Space Telescope A901/2 Galaxy Evolution Survey (STAGES). STAGES is a multiwavelength project designed to probe physical drivers of galaxy evolution across a wide range of environments and luminosity. A complex multi-cluster system at z~0.165 has been the subject of an 80-orbit F606W HST/ACS mosaic covering the full 0.5x0.5 (~5x5 Mpc^2) span of the supercluster. Extensive multiwavelength observations with XMM-Newton, GALEX, Spitzer, 2dF, GMRT, and the 17-band COMBO-17 photometric redshift survey complement the HST imaging. Our survey goals include simultaneously linking galaxy morphology with other observables such as age, star-formation rate, nuclear activity, and stellar mass. In addition, with the multiwavelength dataset and new high resolution mass maps from gravitational lensing, we are able to disentangle the large-scale structure of the system. By examining all aspects of environment we will be able to evaluate the relative importance of the dark matter halos, the local galaxy density, and the hot X-ray gas in driving galaxy transformation. This paper describes the HST imaging, data reduction, and creation of a master catalogue. We perform Sersic fitting on the HST images and conduct associated simulations to quantify completeness. In addition, we present the COMBO-17 photometric redshift catalogue and estimates of stellar masses and star-formation rates for this field. We define galaxy and cluster sample selection criteria which will be the basis for forthcoming science analyses, and present a compilation of notable objects in the field. Finally, we describe the further multiwavelength observations and announce public access to the data and catalogues.Comment: 29 pages, 22 figures; accepted to MNRAS. Full data release available at http://www.nottingham.ac.uk/astronomy/stage