Self-Assembly of Supramolecular Triblock Copolymer Complexes

Four different poly(tert-butoxystyrene)-b-polystyrene-b-poly(4-vinylpyridine) (PtBOS-b-PS-b-P4VP) linear triblock copolymers, with the P4VP weight fraction varying from 0.08 to 0.39, were synthesized via sequential anionic polymerization. The values of the unknown interaction parameters between styrene and tert-butoxystyrene and between tert-butoxystyrene and 4-vinylpyridine were determined from random copolymer blend miscibility studies and found to satisfy 0.031<χS,tBOS<0.034 and 0.39<χ4VP,tBOS<0.43, the latter being slightly larger than the known 0.30<χS,4VP≤0.35 value range. All triblock copolymers synthesized adopted a P4VP/PS core/shell cylindrical self-assembled morphology. From these four triblock copolymers supramolecular complexes were prepared by hydrogen bonding a stoichiometric amount of pentadecylphenol (PDP) to the P4VP blocks. Three of these complexes formed a triple lamellar ordered state with additional short length scale ordering inside the P4VP(PDP) layers. The self-assembled state of the supramolecular complex based on the triblock copolymer with the largest fraction of P4VP consisted of alternating layers of PtBOS and P4VP(PDP) layers with PS cylinders inside the latter layers. The difference in morphology between the triblock copolymers and the supramolecular complexes is due to two effects: (i) a change in effective composition and, (ii) a reduction in interfacial tension between the PS and P4VP containing domains. The small angle X-ray scattering patterns of the supramolecules systems are very temperature sensitive. A striking feature is the disappearance of the first order scattering peak of the triple lamellar state in certain temperature intervals, while the higher order peaks (including the third order) remain. This is argued to be due to the thermal sensitivity of the hydrogen bonding and thus directly related to the very nature of these systems.

Psychotropic drug influences on brain acetylcholine utilization

The cholinergic antisynthesis agent HC-3 was given intraventricularly to young male rats 20–30 days old to deplete brain acetylcholine (ACh). The rate of HC-3 induced depletion of ACh was used as an index of ACh utilization. Total brain ACh was determined following various doses of chlordiazepoxide, pentobarbital, chlorpromazine, methotrimeprazine, imipramine, morphine, d -amphetamine, scopolamine, LSD-25, and phencyclidine given i.p. alone and after intraventricular administration of HC-3. It was found that psychotropic drugs have marked differential effects on the rate of HC-3 induced ACh depletion.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/46382/1/213_2004_Article_BF00421968.pd

Benefit of an electronic head‐mounted low vision aid

Purpose: To evaluate the efficacy of electronic head-mounted low vision aid (e-LVA) SightPlus (GiveVision, UK, givevision.net) and to determine which people with low vision would see themselves likely using an e-LVA like this. Methods: Sixty participants with low vision aged 18 to 93 used SightPlus during an in-clinic study session based on a mixed methods design. Visual acuity (ETDRS), contrast sensitivity (Pelli-Robson) and reading performance (MNREAD) were measured binocularly at baseline (no device), with the device in ‘normal’ mode (zoom only), and with preferred enhanced mode (zoom and one of four digital image enhancements). At the end of the session, a short questionnaire recorded willingness to use an e-LVA like SightPlus, potential use cases, positive/negative comments and adverse effects. Results: Binocular distance visual acuity improved significantly by 0.63 logMAR on average (p < 0.0001) to 0.20 logMAR. Contrast sensitivity improved significantly by 0.22 log units (p < 0.0001) to 1.21 log units with zoom only and by 0.40 log units to 1.37 log units with zoom and preferred image enhancement. Reading performance improved significantly for near visual acuity and critical print size (p < 0.015), although reading speed significantly decreased (p < 0.0001). Nearly half (47%) of the participants indicated they would use an e-LVA like SightPlus, especially for television, reading and entertainment (e.g. theatre). Multivariate logistic regression showed that proportion of lifetime affected by sight loss, baseline contrast sensitivity and use of electronic LVAs explained 41% of the variation in willingness to use. Conclusions: SightPlus improves visual function in people with low vision and would be used in its current form by one half of the people who tried it. Adverse effects were infrequent and resolved when the device was removed. Future work should focus on comparing e-LVAs through repeatable real-world tasks and impact on quality of life

Building social capital through breastfeeding peer support: Insights from an evaluation of a voluntary breastfeeding peer support service in North-West England

Background: Peer support is reported to be a key method to help build social capital in communities. To date there are no studies that describe how this can be achieved through a breastfeeding peer support service. In this paper we present findings from an evaluation of a voluntary model of breastfeeding peer support in North-West England to describe how the service was operationalized and embedded into the community. This study was undertaken from May, 2012 to May, 2013. Methods: Interviews (group or individual) were held with 87 participants: 24 breastfeeding women, 13 peer supporters and 50 health and community professionals. The data contained within 23 monthly monitoring reports (January, 2011 to February 2013) compiled by the voluntary peer support service were also extracted and analysed. Results: Thematic analysis was undertaken using social capital concepts as a theoretical lens. Key findings were identified to resonate with ’bonding’, ‘bridging’ and ‘linking’ forms of social capital. These insights illuminate how the peer support service facilitates ‘bonds’ with its members, and within and between women who access the service; how the service ‘bridges’ with individuals from different interests and backgrounds, and how ‘links’ were forged with those in authority to gain access and reach to women and to promote a breastfeeding culture. Some of the tensions highlighted within the social capital literature were also identified. Conclusions: Horizontal and vertical relationships forged between the peer support service and community members enabled peer support to be embedded into care pathways, helped to promote positive attitudes to breastfeeding and to disseminate knowledge and maximise reach for breastfeeding support across the community. Further effort to engage with those of different ethnic backgrounds and to resolve tensions between peer supporters and health professionals is warranted

The socialist blues? Citizenship, class and civil society

This article seeks to explore the relationship between the British labour movement, the Left and the Labour party. It does so through the intellectual prism of debates around citizenship and civil society. In this respect, I seek to recover a critical politics around questions of class from the New Left who were always critical of more mainstream ideas of citizenship. However, I also point to the limitations of those who have argued that meaningful forms of citizenship can no longer be connected to political parties and only occurs outside of state organizations. Political parties continue to need intellectual narratives to legitimate their role in society and to connect with the broader civil order.The Labour Party in this respect has seemingly broken with ‘New Labour’ and is searching for a new narrative. The rise of an intellectual grouping around ‘Blue Labour’ has made considerable headway recently and I seek to take a critical view of some of their ideas and ethical frameworks. Here I argue that changing class formations and a more pluralistic society potentially ask difficult questions of those who seek to revive the labour movement in troubled times

Functionalized Poly(3-hexylthiophene)s via Lithium–Bromine Exchange

Poly(3-hexylthiophene) (P3HT) is one of the most extensively investigated conjugated polymers and has been employed as the active material in many devices including field-effect transistors, organic photovoltaics and sensors. As a result, methods to further tune the properties of P3HT are desirable for specific applications. Herein, we report a facile postpolymerization modification strategy to functionalize the 4-position of commercially available P3HT in two simple steps–bromination of the 4-position of P3HT (Br–P3HT) followed by lithium−bromine exchange and quenching with an electrophile. We achieved near quantitative lithium–bromine exchange with Br–P3HT, which requires over 100 thienyl lithiates to be present on a single polymer chain. The lithiated-P3HT is readily combined with functional electrophiles, resulting in P3HT derivatives with ketones, secondary alcohols, trimethylsilyl (TMS) group, fluorine, or an azide at the 4-position. We demonstrated that the azide-modified P3HT could undergo Cu-catalyzed or Cu-free click chemistry, significantly expanding the complexity of the structures that can be appended to P3HT using this method.National Science Foundation (U.S.) (ECCS-0939514

Depleted dissolved organic carbon and distinct bacterial communities in the water column of a rapid-flushing coral reef ecosystem

Author Posting. © The Author(s), 2011. This is the author's version of the work. It is posted here by permission of Nature Publishing Group for personal use, not for redistribution. The definitive version was published in The ISME Journal 5 (2011): 1374–1387, doi:10.1038/ismej.2011.12.Coral reefs are highly productive ecosystems bathed in unproductive, low-nutrient oceanic waters, where microbially-dominated food webs are supported largely by bacterioplankton recycling of dissolved compounds. Despite evidence that benthic reef organisms efficiently scavenge particulate organic matter and inorganic nutrients from advected oceanic waters, our understanding of the role of bacterioplankton and dissolved organic matter in the interaction between reefs and the surrounding ocean remains limited. Here we present the results of a four-year study conducted in a well-characterized coral reef ecosystem (Paopao Bay, Moorea, French Polynesia) where changes in bacterioplankton abundance and dissolved organic carbon (DOC) concentrations were quantified and bacterial community structure variation was examined along spatial gradients of the reef:ocean interface. Our results illustrate that the reef is consistently depleted in concentrations of both DOC and bacterioplankton relative to offshore waters (averaging 79 µmol L-1 DOC and 5.5 X 108 cells L-1 offshore and 68 µmol L-1 DOC and 3.1 X 108 cells L-1 over the reef, respectively) across a four year time period. In addition, using a suite of culture-independent measures of bacterial community structure, we found consistent differentiation of reef bacterioplankton communities from those offshore or in a nearby embayment across all taxonomic levels. Reef habitats were enriched in Gamma-, Delta-, and Beta-proteobacteria, Bacteriodetes, Actinobacteria and Firmicutes. Specific bacterial phylotypes, including members of the SAR11, SAR116, Flavobacteria, and Synechococcus clades, exhibited clear gradients in relative abundance among nearshore habitats. Our observations indicate that this reef system removes oceanic DOC and exerts selective pressures on bacterioplankton community structure on timescales approximating reef water residence times, observations which are notable both because fringing reefs do not exhibit long residence times (unlike those characteristic of atoll lagoons) and because oceanic DOC is generally recalcitrant to degradation by ambient microbial assemblages. Our findings thus have interesting implications for the role of oceanic DOM and bacterioplankton in the ecology and metabolism of reef ecosystems.This project was supported by the US National Science Foundation Moorea Coral Reef Long Term Ecological Research project (NSF OCE-0417412) through minigrants to CAC and NSF OCE-0927411 to CAC as well as the MIRADA-LTERs program (NSF DEB-0717390 to LAZ)

Molecular Transducers of Human Skeletal Muscle Remodeling under Different Loading States

Loading of skeletal muscle changes the tissue phenotype reflecting altered metabolic and functional demands. In humans, heterogeneous adaptation to loading complicates the identification of the underpinning molecular regulators. A within-person differential loading and analysis strategy reduces heterogeneity for changes in muscle mass by ∼40% and uses a genome-wide transcriptome method that models each mRNA from coding exons and 3′ and 5′ untranslated regions (UTRs). Our strategy detects ∼3–4 times more regulated genes than similarly sized studies, including substantial UTR-selective regulation undetected by other methods. We discover a core of 141 genes correlated to muscle growth, which we validate from newly analyzed independent samples (n = 100). Further validating these identified genes via RNAi in primary muscle cells, we demonstrate that members of the core genes were regulators of protein synthesis. Using proteome-constrained networks and pathway analysis reveals notable relationships with the molecular characteristics of human muscle aging and insulin sensitivity, as well as potential drug therapies

Factors shaping prayer frequency among 9- to 11-year-olds

This paper begins by reviewing the evidence from international research concerning the personal and social correlates of prayer frequency during childhood and adolescence. Overall these data continue to support the view that young people who pray not only report higher levels of personal wellbeing but also report higher levels of pro-social attitudes. These findings raise a research question of particular relevance within church schools regarding the factors that predict higher levels of prayer activity among students. The Student Voice Project offers data that can illuminate this research question. Among the 3,101 9- to 11-year old students who participated in the project 11% prayed daily, 9% at least once a week, 32% sometimes, 11% once or twice a year, and 37% never. The present paper tests the power of four sets of predictor variables to account for individual differences in prayer frequency among these students: personal factors (age and sex), psychological factors (using the three dimensional model of personality proposed by Eysenck), church attendance (self, mother, and father), and family discussion about prayer (mother, father, and grandparents). Multiple regression analyses identified the discussion of prayer with the mother as the single most important predictor. These findings locate the development of the practice of prayer within the home, even more than within the church