Evidence for Charging Effects in CdTe/CdMgTe Quantum Point Contacts

Here we report on fabrication and low temperature magnetotransport measurements of quantum point contacts patterned from a novel two-dimensional electron system - CdTe/CdMgTe modulation doped heterostructure. From the temperature and bias dependence we ascribe the reported data to evidence for a weakly bound state which is naturally formed inside a CdTe quantum constrictions due to charging effects. We argue that the spontaneous introduction of an open dot is responsible for the replacement of flat conductance plateaus by quasi-periodic resonances with amplitude less than 2e^{2}/h, as found in our system. Additionally, below 1 K a pattern of weaker conductance peaks, superimposed upon wider resonances, is also observed.Comment: 4 pages, 4 figure

Selection of strain and optimization of mutanase production in submerged cultures of Trichoderma harzianum

Nineteen fungal strains belonging to different genera were tested for extracellular mutanase production in shaken flasks. The optimal enzymatic activity was achieved by Trichoderma harzianum F-470, a strain for which the mutanase productivity has not yet been published. Some of factors affecting the enzyme production in shaken flasks and aerated fermenter cultures have been standardized. Mandels mineral medium with initial pH 5.3, containing 0.25% mutan and inoculated with 10% of the 48-h mycelium, was the best for enzyme production. A slight mutanolytic activity was also found when sucrose, raffinose, lactose and melibiose were carbon sources. Application of optimized medium and cultural conditions, as well as use of a fermenter with automatic pH control set at pH 6.0 enabled to obtain a high mutanase yield (0.33 U/ml, 2.5 U/mg protein) in a short time (2-3 days). The enzyme in crude state was stable over a pH range of 4.5-6.0, and at temperatures up to 35 °C; its maximum activity was at 40 °C and at pH 5.5

Fractional Quantum Hall Effect in a Diluted Magnetic Semiconductor

We report the observation of the fractional quantum Hall effect in the lowest Landau level of a two-dimensional electron system (2DES), residing in the diluted magnetic semiconductor Cd(1-x)Mn(x)Te. The presence of magnetic impurities results in a giant Zeeman splitting leading to an unusual ordering of composite fermion Landau levels. In experiment, this results in an unconventional opening and closing of fractional gaps around filling factor v = 3/2 as a function of an in-plane magnetic field, i.e. of the Zeeman energy. By including the s-d exchange energy into the composite Landau level spectrum the opening and closing of the gap at filling factor 5/3 can be modeled quantitatively. The widely tunable spin-splitting in a diluted magnetic 2DES provides a novel means to manipulate fractional states

Mutanase from Paenibacillus sp. MP-1 produced inductively by fungal α-1,3-glucan and its potential for the degradation of mutan and Streptococcus mutans biofilm

Laetiporus sulphureus is a source of α-1,3-glucan that can substitute for the commercially-unavailable streptococcal mutan used to induce microbial mutanases. The water-insoluble fraction of its fruiting bodies from 0.15 to 0.2% (w/v) induced mutanase activity in Paenibacillus sp. MP-1 at 0.35 μ ml−1. The mutanase extensively hydrolyzed streptococcal mutan, giving 23% of saccharification, and 83% of solubilization of glucan after 6 h. It also degraded α-1,3-polymers of biofilms, formed in vitro by Streptococcus mutans, even after only 3 min of contact

Attributing minds to vampires in Richard Matheson’s I Am Legend

For Palmer (2004, 2010), and other proponents of a cognitive narratology, research into real-world minds in the cognitive sciences provides insights into readers’ experiences of fictional minds. In this article, I explore the application of such research to the minds constructed for the vampire characters in Richard Matheson’s (1954) science fiction/horror novel I Am Legend. I draw upon empirical research into ‘mind attribution’ in social psychology, and apply Cognitive Grammar (Langacker, 2008), and its notion of ‘construal’, as a framework for the application of such findings to narrative. In my analysis, I suggest that readers’ attribution of mental-states to the vampires in Matheson’s novel is strategically limited through a number of choices in their linguistic construal. Drawing on online reader responses to the novel, I argue that readers’ understanding of these other minds plays an important role in their empathetic experience and their ethical judgement of the novel’s main character and focaliser, Robert Neville. Finally, I suggest that the limited mind attribution for the vampires invited through their construal contributes to the presentation of a ‘mind style’ (Fowler, 1977) for this character