Effect of dipolar moments in domain sizes of lipid bilayers and monolayers

Lipid domains are found in systems such as multi-component bilayer membranes and single component monolayers at the air-water interface. It was shown by Andelman et al. (Comptes Rendus 301, 675 (1985)) and McConnell et al. (Phys. Chem. {\bf 91}, 6417 (1987)) that in monolayers, the size of the domains results from balancing the line tension, which favors the formation of a large single circular domain, against the electrostatic cost of assembling the dipolar moments of the lipids. In this paper, we present an exact analytical expression for the electric potential, ion distribution and electrostatic free energy for different problems consisting of three different slabs with different dielectric constants and Debye lengths, with a circular homogeneous dipolar density in the middle slab. From these solutions, we extend the calculation of domain sizes for monolayers to include the effects of finite ionic strength, dielectric discontinuities (or image charges) and the polarizability of the dipoles and further generalize the calculations to account for domains in lipid bilayers. In monolayers, the size of the domains is dependent on the different dielectric constants but independent of ionic strength. In asymmetric bilayers, where the inner and outer leaflets have different dipolar densities, domains show a strong size dependence with ionic strength, with molecular-sized domains that grow to macroscopic phase separation with increasing ionic strength. We discuss the implications of the results for experiments and briefly consider their relation to other two dimensional systems such as Wigner crystals or heteroepitaxial growth.Comment: 13 pages, 5 figues in eps Replaced with new version, one citation added and a few statements corrected. The results of the paper are unchange

Constrained action selection in children with developmental coordination disorder

The effect of advance (‘precue’) information on short aiming movements was explored in adults, high school children, and primary school children with and without developmental coordination disorder (n = 10, 14, 16, 10, respectively). Reaction times in the DCD group were longer than in the other groups and were more influenced by the extent to which the precue constrained the possible action space. In contrast, reaction time did not alter as a function of precue condition in adults. Children with DCD showed greater inaccuracy of response (despite the increased RT). We suggest that the different precue effects reflect differences in the relative benefits of priming an action prior to definitive information about the movement goal. The benefits are an interacting function of the task and the skill level of the individual. Our experiment shows that children with DCD gain a benefit from advance preparation in simple aiming movements, highlighting their low skill levels. This result suggests that goal-directed RTs may have diagnostic potential within the clinic

Further information on the origin of the Yale and Oak Ridge wild-type strains of Neurospora crassa

Further information on the origin of the Yale and Oak Ridge wild-type strains of Neurospora crass

Services diagnostic and needs assessment study

Liberalisation of trade in services and associated domestic reforms is fundamental to the realisation of the ASEAN Economic Community (AEC). However, this requires real (‘on the ground’) liberalisation, not simply “on paper” liberalisation in the form of commitments under the ASEAN Framework Agreement on Services (AFAS), a sideshow in services liberalisation. The decision by leaders to form an AEC covering also the free flow of services has put the emphasis very much on ensuring each ASEAN Member State (AMS) removes restrictions affecting trade in services (including related foreign investment) and implement related reforms. However, the diagnostic analysis presented in this Services Diagnostic and Needs Assessment Study (SDNAS), including in the in-country reports, suggests this is not happening, or at least is going very slowly, especially when set against the adopted start date for the AEC of 2015. Hence, key and effective technical assistance and capacity building is needed to advance ‘on the ground’ liberalisation of services and related reforms. The in-country fieldwork and other analysis undertaken in the SDNAS helped identify constraints and provided a list of potential technical assistance and capacity building projects to help address them, both from a primarily cross-cutting but also a sectoral perspective. The SDNAS has also adopted an economic framework based on the fundamental benefits of unilateral liberalisation and a strategic structured approach, to identify key areas (‘umbrellas’) needing technical assistance and capacity building activities, such as strengthening the evidence base, promoting transparency, developing strategies and planning, and raising understanding and awareness. Key activity clusters were also identified within these three ‘umbrellas’, such as policy analysis, services policy visions, and organisations for dialogues, respectively. Individual priority technical assistance and capacity building project proposals within these clusters were determined using a cost-benefit analytical approach. The SNDAS importantly recommends the need to re-balance much of the technical assistance and capacity building activities away from being directed at servicing the AFAS trade negotiations and focusing on ‘on-paper’ liberalisation towards efforts to build transparency and fundamental support for services trade liberalisation and related reforms in AMS. This is what is required to achieve the necessary ‘on-the-ground’ changes to achieve the AEC. This is consistent with international experience that significant ‘on-the-ground’ services liberalisation and related reforms requires unilateral efforts, and that trade negotiations have generally failed to deliver such changes. With this in mind, the SNDAS has developed and recommended a number of detailed proposed technical assistance and capacity building project templates

Dual HLA B*42 and B*81-reactive T cell receptors recognize more diverse HIV-1 Gag escape variants

Closely related HLA alleles presenting similar HIV-1 epitopes can be associated with variable clinical outcome. Here the authors report their findings on CD8+ T cell responses to the HIV-1 Gag-p24 TL9 immunodominant epitope in the context of closely related protective and less protective HLA alleles, and their differential effect on viral contro

Measuring the Plasticity of Social Approach: A Randomized Controlled Trial of the Effects of the PEERS Intervention on EEG Asymmetry in Adolescents with Autism Spectrum Disorders

This study examined whether the Program for the Education and Enrichment of Relational Skills (PEERS: Social skills for teenagers with developmental and autism spectrum disorders: The PEERS treatment manual, Routledge, New York, 2010a) affected neural function, via EEG asymmetry, in a randomized controlled trial of adolescents with Autism spectrum disorders (ASD) and a group of typically developing adolescents. Adolescents with ASD in PEERS shifted from right-hemisphere gamma-band EEG asymmetry before PEERS to left-hemisphere EEG asymmetry after PEERS, versus a waitlist ASD group. Left-hemisphere EEG asymmetry was associated with more social contacts and knowledge, and fewer symptoms of autism. Adolescents with ASD in PEERS no longer differed from typically developing adolescents in left-dominant EEG asymmetry at post-test. These findings are discussed via the Modifier Model of Autism (Mundy et al. in Res Pract Persons Severe Disabl 32(2):124, 2007), with emphasis on remediating isolation/withdrawal in ASD

HLA-Associated viral mutations are common in human immunodeficiency virus type 1 elite controllers

Elite controllers (EC) of human immunodeficiency virus type 1 (HTV-1) maintain viremia below the limit of detection without antiretroviral treatment. Virus-specific cytotoxic CD8+ T lymphocytes are believed to play a crucial role in viral containment, but the degree of immune imprinting and compensatory mutations in EC is unclear. We obtained plasma gag, pol, and nef sequences from HLA-diverse subjects and found that 30 to 40% of the predefined HLA-associated polymorphic sites show evidence of immune selection pressure in EC., compared to approximately 50% of the sites in chronic progressors. These data indicate ongoing viral replication and escape from cytotoxic T lymphocytes are present even in strictly controlled HTV-1 infection

PHOTOCHEMICAL RING-OPENING IN meso-CHLORINATED CHLOROPHYLLS

Irradiation of 20-chloro-chlorophylls of the a-type with visible light produces long-wavelength shifted photoproducts, which transform in the dark to linear tetrapyrroles (bile pigments). The possible significance for chlorophyll degradation is discussed