Differential Imaging of Biological Structures with Doubly-resonant Coherent Anti-stokes Raman Scattering (CARS)

Coherent Raman imaging techniques have seen a dramatic increase in activity over the past decade due to their promise to enable label-free optical imaging with high molecular specificity 1. The sensitivity of these techniques, however, is many orders of magnitude weaker than fluorescence, requiring milli-molar molecular concentrations 1,2. Here, we describe a technique that can enable the detection of weak or low concentrations of Raman-active molecules by amplifying their signal with that obtained from strong or abundant Raman scatterers. The interaction of short pulsed lasers in a biological sample generates a variety of coherent Raman scattering signals, each of which carry unique chemical information about the sample. Typically, only one of these signals, e.g. Coherent Anti-stokes Raman scattering (CARS), is used to generate an image while the others are discarded. However, when these other signals, including 3-color CARS and four-wave mixing (FWM), are collected and compared to the CARS signal, otherwise difficult to detect information can be extracted 3. For example, doubly-resonant CARS (DR-CARS) is the result of the constructive interference between two resonant signals 4. We demonstrate how tuning of the three lasers required to produce DR-CARS signals to the 2845 cm-1 CH stretch vibration in lipids and the 2120 cm-1 CD stretching vibration of a deuterated molecule (e.g. deuterated sugars, fatty acids, etc.) can be utilized to probe both Raman resonances simultaneously. Under these conditions, in addition to CARS signals from each resonance, a combined DR-CARS signal probing both is also generated. We demonstrate how detecting the difference between the DR-CARS signal and the amplifying signal from an abundant molecule's vibration can be used to enhance the sensitivity for the weaker signal. We further demonstrate that this approach even extends to applications where both signals are generated from different molecules, such that e.g. using the strong Raman signal of a solvent can enhance the weak Raman signal of a dilute solute

Empowerment/sexism: Figuring female sexual agency in contemporary advertising

This paper argues that there has been a significant shift in advertising representations of women in recent years, such that rather than being presented as passive objects of the male gaze, young women in adverts are now frequently depicted as active, independent and sexually powerful. This analysis examines contemporary constructions of female sexual agency in advertisements examining three recognizable ‘figures’: the young, heterosexually desiring ‘midriff’, the vengeful woman set on punishing her partner or ex partner for his transgressions, and the ‘hot lesbian’, almost always entwined with her beautiful Other or double. Using recent examples of adverts the paper asks how this apparent ‘agency’ and ‘empowerment’ should be understood. Drawing on accounts of the incorporation or recuperation of feminist ideas in advertising the paper takes a critical approach to these representations, examining their exclusions, their constructions of gender relations and heteronormativity, and the way power is figured within them. A feminist poststructuralist approach is used to interrogate the way in which ‘sexual agency’ becomes a form of regulation in these adverts, that requires the re-moulding of feminine subjectivity to fit the current postfeminist, neoliberal moment in which young women should not only be beautiful but sexy, sexually knowledgeable/practised and always ‘up for it’. The paper makes an original contribution to debates about representations of gender in advertising, to poststructuralist analyses about the contemporary operation of power, and to writing about female ‘sexual agency’ by suggesting that ‘voice’ or ‘agency’ may not be the solution to the ‘missing discourse of female desire' but may in fact be a technology of discipline and regulation

Dynamics of social class contempt in contemporary British television comedy

This is the author's accepted manuscript. The final published article is available from the link below. Copyright @ 2010 Taylor & Francis.British television comedy has often ridiculed the complexities and characteristics of social class structures and identities. In recent years, poor white socially marginalised groups, now popularly referred to as “chavs”, have become a prevalent comedy target. One of the most popular and controversial television “comedy chavs” is Little Britain's fictional teenage single mother, Vicky Pollard. This article examines the representation of Vicky Pollard in light of contemporary widespread abuse of the white working class. Highlighting the polysemic and ambivalent nature of Vicky Pollard's representation, the article argues that whilst Little Britain's characterisation of Vicky Pollard largely contributes to contemporary widespread demonisation of the working class, there are moments within Little Britain when a more sympathetic tone towards the poor working class may be read, and where chav identities are used to ridicule the pretensions, superficiality, and falsity of middle-class identities. The article concludes that television comedy has been, and continues to be, a significant vehicle through which serious concerns, anxieties, and questions about social class and class identities are discursively constructed and contested

Determinants of Bacteriophage 933W Repressor DNA Binding Specificity

We reported previously that 933W repressor apparently does not cooperatively bind to adjacent sites on DNA and that the relative affinities of 933W repressor for its operators differ significantly from that of any other lambdoid bacteriophage. These findings indicate that the operational details of the lysis-lysogeny switch of bacteriophage 933W are unique among lambdoid bacteriophages. Since the functioning of the lysis-lysogeny switch in 933W bacteriophage uniquely and solely depends on the order of preference of 933W repressor for its operators, we examined the details of how 933W repressor recognizes its DNA sites. To identify the specificity determinants, we first created a molecular model of the 933W repressor-DNA complex and tested the predicted protein-DNA interactions. These results of these studies provide a picture of how 933W repressor recognizes its DNA sites. We also show that, opposite of what is normally observed for lambdoid phages, 933W operator sequences have evolved in such a way that the presence of the most commonly found base sequences at particular operator positions serves to decrease, rather than increase, the affinity of the protein for the site. This finding cautions against assuming that a consensus sequence derived from sequence analysis defines the optimal, highest affinity DNA binding site for a protein

Can hippocampal neurites and growth cones climb over obstacles?

Guidance molecules, such as Sema3A or Netrin-1, can induce growth cone (GC) repulsion or attraction in the presence of a flat surface, but very little is known of the action of guidance molecules in the presence of obstacles. Therefore we combined chemical and mechanical cues by applying a steady Netrin-1 stream to the GCs of dissociated hippocampal neurons plated on polydimethylsiloxane (PDMS) surfaces patterned with lines 2 \ub5m wide, with 4 \ub5m period and with a height varying from 100 to 600 nm. GC turning experiments performed 24 hours after plating showed that filopodia crawl over these lines within minutes. These filopodia do not show staining for the adhesion marker Paxillin. GCs and neurites crawl over lines 100 nm high, but less frequently and on a longer time scale over lines higher than 300 nm; neurites never crawl over lines 600 nm high. When neurons are grown for 3 days over patterned surfaces, also neurites can cross lines 300 nm and 600 nm high, grow parallel to and on top of these lines and express Paxillin. Axons - selectively stained with SMI 312 - do not differ from dendrites in their ability to cross these lines. Our results show that highly motile structures such as filopodia climb over high obstacle in response to chemical cues, but larger neuronal structures are less prompt and require hours or days to climb similar obstacles

Screening Depression and Anxiety via Brief Measures of Psychological Inflexibility

We evaluated the usefulness of scores from two transdiagnostic scales—the 8-item version of the Avoidance and Fusion Questionnaire for Youth (AFQ-Y8) and the second edition of the Avoidance and Action Questionnaire (AAQ-II)—for estimating symptom severity on two measures of depression and anxiety. Responses to both measures of psychological inflexibility were analyzed to determine how well scores estimated anxiety and depression above or below a given severity level and at specific categories of symptom severity. Findings indicated that scores from both measures were acceptable to excellent screeners of concurrent ratings of anxiety and depression. Results varied somewhat depending on the measure used, level of severity targeted, and scope of screening. By investigating the screening accuracy of these transdiagnostic measures and potential cut scores to ease in interpreting results, we hope these measures might prove useful for addressing barriers in public health screening endeavors

ACT in Schools: A Public Health Approach

This chapter makes the conceptual and empirical case for using acceptance and commitment therapy (ACT) with youth in school settings. We provide background for this project by making a logical, evidence-based case for school-based mental health services more generally. We then outline a public health approach to using ACT in schools via multitiered system of supports (MTSS), which emphasizes scaled prevention at universal, targeted, and intensive levels. Following, we review the existing literature on ACT in schools—concluding there is adequate evidence to support use at the targeted level, encouraging yet weaker evidence supporting use at the universal level, and promising yet extremely limited evidence for use at the intensive level. We close the chapter by discussing the limitations and challenges of using ACT in schools, offering future directions for progressing research and practice. We suggest future work in this area might especially benefit from (a) enhancing the methodological rigor of research designs in school-based studies, (b) testing the viability of brief or focused ACT at the targeted level in schools, (c) investigating the treatment utility of ACT-related process measures in schools, and (d) expanding the scope of ACT in schools to promote the wellbeing of teachers and other educators

Lipid-cell interactions in human monocytes investigated by doubly-resonant coherent anti-Stokes Raman scattering (DR-CARS) microscopy

Weeks T, Schie J, den Hartigh LJ, Rutledge JC, Huser T. Lipid-cell interactions in human monocytes investigated by doubly-resonant coherent anti-Stokes Raman scattering (DR-CARS) microscopy. J.Biomed.Opt. 2011;16(2): 21117

Cultivating Mindfulness in Schools to Promote Well-Being

This chapter orients readers to the landscape of mindfulness and mindfulness-based intervention (MBI) in schools. First, definitions and examples of the key constructs are given: mindfulness and MBI. Next, a discussion is provided on the empirical support and contemporary issues surrounding two aspects of evidence-based practice related to mindfulness in schools: MBI and mindfulness measurement. Following, major considerations are highlighted related to the practical application of mindfulness in schools, focusing on the benefit of a multireed service delivery and the relevance of diversity and developmental considerations when applying mindfulness for the benefit of all in schools. On the whole, this chapter offers a realistic yet optimistic perspective on mindfulness and MBI—suggesting a promising, empirically supported approach for promoting desirable positive psychological functioning among students and their caregivers. Yet much is still unknown; thus, much work remains to inform a thoroughgoing evidence-based approach to using mindfulness and MBI in schools