The computation of the cohomology rings of all groups of order 128

We describe the computation of the mod-2 cohomology rings of all 2328 groups of order 128. One consequence is that all groups of order less than 256 satisfy the strong form of Benson's Regularity Conjecture.Comment: 15 pages; revised versio

Discs in misaligned binary systems

We perform SPH simulations to study precession and changes in alignment between the circumprimary disc and the binary orbit in misaligned binary systems. We find that the precession process can be described by the rigid-disc approximation, where the disc is considered as a rigid body interacting with the binary companion only gravitationally. Precession also causes change in alignment between the rotational axis of the disc and the spin axis of the primary star. This type of alignment is of great important for explaining the origin of spin-orbit misaligned planetary systems. However, we find that the rigid-disc approximation fails to describe changes in alignment between the disc and the binary orbit. This is because the alignment process is a consequence of interactions that involve the fluidity of the disc, such as the tidal interaction and the encounter interaction. Furthermore, simulation results show that there are not only alignment processes, which bring the components towards alignment, but also anti-alignment processes, which tend to misalign the components. The alignment process dominates in systems with misalignment angle near 90 degrees, while the anti-alignment process dominates in systems with the misalignment angle near 0 or 180 degrees. This means that highly misaligned systems will become more aligned but slightly misaligned systems will become more misaligned.Comment: 15 pages, 16 figures, 1 table, accepted for publication in MNRA

Effects of low incubation temperatures on the bactericidal activity of anti-tuberculosis drugs

OBJECTIVES: to explore the effect of low incubation temperatures and the consequent slowing of bacterial metabolism on the bactericidal action of anti-tuberculosis drugs against Mycobacterium tuberculosis. METHODS: counting of surviving bacteria during exposure of static cultures to 1 mg/L isoniazid, 2 mg/L rifampicin, 0.5 or 2 mg/L TMC207 and 40 or 160 mg/L pyrazinamide, usually for periods of 21 days at temperatures of 37, 25, 22, 19, 16 or 8°C. RESULTS: the bactericidal activities of isoniazid and rifampicin were progressively reduced at 25 and 22°C, and were minimal at lower temperatures. TMC207 was immediately bactericidal at 37°C, in contrast to the early static phase reported with log phase cultures, and showed less change in activity as incubation temperatures were reduced than did rifampicin or isoniazid. Pyrazinamide was more bactericidal when incubation temperatures were reduced below 37°C and when the static seed cultures were most dormant. CONCLUSIONS: these results can be explained by the surmise that at low temperatures bacterial energy is at a low level with only just sufficient ATP to maintain homeostasis, making the bacteria more susceptible to the blocking of ATP synthesis by TMC207. Insufficient ATP at low temperature would also hinder the export of pyrazinoic acid, the toxic product of the pro-drug pyrazinamide, from the mycobacterial cell by an inefficient efflux pump that requires energ

Prosocial and antisocial children's perceptions of peers' motives for prosocial behaviours

This study investigated whether peer-nominated prosocial and antisocial children have different perceptions of the motives underlying peers' prosocial actions. Eighty-seven children, aged 10-12 years old, completed peer-nomination measures of social behaviour. On the basis of numbers of social nominations received, a subsample of 51 children (32 who were peer-nominated as 'prosocial', and 18 who were peer-nominated as 'antisocial') then recorded their perceptions of peers' motives for prosocial behaviours. Expressed motives were categorized predominantly into three categories, coinciding with Turiel's (1978) 'moral', 'conventional', and 'personal domains'. Results indicate that children's social reputation is associated with the extent to which they perceive peers' prosocial motives as 'personal' or 'moral', with more prosocial children attributing moral motives, and more antisocial children attributing personal motives. Although traditionally Turiel's domain theory has been used to understand 'antisocial' children's behaviour, the current findings suggest that 'prosocial' children's behaviour may also be related to domains of judgment

Emotive computing may have a role in telecare

This brief paper sets out arguments for the introduction of new technologies into telecare and lifestyle monitoring that can detect and monitor the emotive state of patients. The significantly increased use of computers by older people will enable the elements of emotive computing to be integrated with features such as keyboards and webcams, to provide additional information on emotional state. When this is combined with other data, there will be significant opportunities for system enhancement and the identification of changes in user status, and hence of need. The ubiquity of home computing makes the keyboard a very attractive, economic and non-intrusive means of data collection and analysis

Discrimination and synthesis of recursive quantum states in high-dimensional Hilbert spaces

We propose an interferometric method for statistically discriminating between nonorthogonal states in high dimensional Hilbert spaces for use in quantum information processing. The method is illustrated for the case of photon orbital angular momentum (OAM) states. These states belong to pairs of bases that are mutually unbiased on a sequence of two-dimensional subspaces of the full Hilbert space, but the vectors within the same basis are not necessarily orthogonal to each other. Over multiple trials, this method allows distinguishing OAM eigenstates from superpositions of multiple such eigenstates. Variations of the same method are then shown to be capable of preparing and detecting arbitrary linear combinations of states in Hilbert space. One further variation allows the construction of chains of states obeying recurrence relations on the Hilbert space itself, opening a new range of possibilities for more abstract information-coding algorithms to be carried out experimentally in a simple manner. Among other applications, we show that this approach provides a simplified means of switching between pairs of high-dimensional mutually unbiased OAM bases

Stimulus-invariant processing and spectrotemporal reverse correlation in primary auditory cortex

The spectrotemporal receptive field (STRF) provides a versatile and integrated, spectral and temporal, functional characterization of single cells in primary auditory cortex (AI). In this paper, we explore the origin of, and relationship between, different ways of measuring and analyzing an STRF. We demonstrate that STRFs measured using a spectrotemporally diverse array of broadband stimuli -- such as dynamic ripples, spectrotemporally white noise, and temporally orthogonal ripple combinations (TORCs) -- are very similar, confirming earlier findings that the STRF is a robust linear descriptor of the cell. We also present a new deterministic analysis framework that employs the Fourier series to describe the spectrotemporal modulations contained in the stimuli and responses. Additional insights into the STRF measurements, including the nature and interpretation of measurement errors, is presented using the Fourier transform, coupled to singular-value decomposition (SVD), and variability analyses including bootstrap. The results promote the utility of the STRF as a core functional descriptor of neurons in AI.Comment: 42 pages, 8 Figures; to appear in Journal of Computational Neuroscienc