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A histological analysis of coloration in the Peruvian mimic poison frog (Ranitomeya imitator)
Aposematism continues to be a phenomenon of central interest in evolutionary biology. The life history of the mimic poison frog, Ranitomeya imitator, relies heavily on aposematism. In order for aposematic signals to be effective, predators must be able to learn to avoid the associated phenotype. However, in R. imitator, aposematism is associated with four different color phenotypes that mimic a complex of congeneric species occurring across the mimic frog's geographic range. Investigations of the underlying mechanics of color production in these frogs can provide insights into how and why these different morphs evolved. We used histological samples to examine divergence in the color production mechanisms used by R. imitator to produce effective aposematic signals across its geographic range. We measured the coverage of melanophores and xanthophores (the area covered by chromatophores divided by total area of the skin section) in each color morph. We find that morphs that produce orange skin exhibit a higher coverage of xanthophores and lower coverage of melanophores than those that produce yellow skin. In turn, morphs that produce yellow skin exhibit a higher coverage of xanthophores and lower coverage of melanophores than those that produce green skin. Generally, across the morphs, a high ratio of xanthophores to melanophores is associated with colors of brighter spectral reflectance. Together, our results contribute to the understanding of color production in amphibians and document divergence in the histology of a species that is subject to divergent selection associated with aposematism
Women’s experiences of receiving care for pelvic organ prolapse: a qualitative study
Background Pelvic organ prolapse is a common urogenital condition affecting 41–50% of women over the age of 40. To achieve early diagnosis and appropriate treatment, it is important that care is sensitive to and meets women’s needs, throughout their patient journey. This study explored women’s experiences of seeking diagnosis and treatment for prolapse and their needs and priorities for improving person-centred care. Methods Twenty-two women receiving prolapse care through urogynaecology services across three purposefully selected NHS UK sites took part in three focus groups and four telephone interviews. A topic guide facilitated discussions about women’s experiences of prolapse, diagnosis, treatment, follow-up, interactions with healthcare professionals, overall service delivery, and ideals for future services to meet their needs. Data were analysed thematically. Results Three themes emerged relating to women’s experiences of a) Evaluating what is normal b) Hobson’s choice of treatment decisions, and c) The trial and error of treatment and technique. Women often delayed seeking help for their symptoms due to lack of awareness, embarrassment and stigma. When presented to GPs, their symptoms were often dismissed and unaddressed until they became more severe. Women reported receiving little or no choice in treatment decisions. Choices were often influenced by health professionals’ preferences which were subtly reflected through the framing of the offer. Women’s embodied knowledge of their condition and treatment was largely unheeded, resulting in decisions that were inconsistent with women’s preferences and needs. Physiotherapy based interventions were reported as helping women regain control over their symptoms and life. A need for greater awareness of prolapse and physiotherapy interventions among women, GPs and consultants was identified alongside greater focus on prevention, early diagnosis and regular follow-up. Greater choice and involvement in treatment decision making was desired. Conclusions As prolapse treatment options expand to include more conservative choices, greater awareness and education is needed among women and professionals about these as a first line treatment and preventive measure, alongside a multi-professional team approach to treatment decision making. Women presenting with prolapse symptoms need to be listened to by the health care team, offered better information about treatment choices, and supported to make a decision that is right for them
Midlands Cadences: Narrative Voices in the Work of Alan Sillitoe
This paper will examine excerpts from a range of Alan Sillitoe’s prose fiction, most notably Saturday Night and Sunday Morning (1958) and short stories from the collection The Loneliness of the Long-Distance Runner (1958), via a comparative exploration of the texts’ representations of Midlands English demotic. Both texts enact Bakhtin’s notion of novelistic dialogism and find much expressive capital in the tension between discourses: between the oral and the written. Indeed, it could be argued that much of Sillitoe’s work functions as a direct challenge to dominant notions of the literary. The narrative discourse attempts to trace a link between the quotidian experience of the Midlands English working classes represented and the demotic language which they speak. His technique also explores the link between language and sensibility; i.e. verbal articulacy need not be a limit to expression of a character’s distinctive identity. In contrast to the more radical techniques of novelists like James Kelman and Irvine Welsh, all instances of phonetically-rendered demotic remain imprisoned by what Joyce called ‘perverted commas’ – as direct speech. However, the diegetic narrative discourse itself is redolent of registers rooted in 1950s English working class life. The texts also contain different methods of representing their protagonists’ consciousness through their own idiolect. In Saturday Night and Sunday Morning, this is evidenced by the use of the second person ‘you’. It functions simultaneously as a representation of Seaton’s consciousness in the oral register which he might choose to articulate it, and as a dialogic ‘sideways glance’ at the reader and assumed shared experience. The second is more redolent of internal monologue, using the first-person form (as seen in the homodiegetic narration of the second novel); crucially, though, it remains in Standard English, if explicitly orientated towards oral register.
Sillitoe’s is a novelistic discourse which refuses to normalise itself to accord with the conventions of classic realism, and as such prefigures the ambitions of many contemporary writers who incline their narrative voices towards the oral – asserting the right of a character’s dialect/idiolect to be the principal register of the narrative. The paper will demonstrate this thesis through the ideas of Bakhtin, and through an analytical taxonomy derived from literary stylistics. It aims to propose a model which can be used to analyse and explore any fiction which has been labelled as ‘working class’, and asserts that such an approach leads to a more principled characterisation of working class fiction (based on its use of language) than current literary-critical discussions based simply on cultural/social context and biography
Para- and Ortho-Substitutions Are Key Determinants of Polybrominated Diphenyl Ether Activity toward Ryanodine Receptors and Neurotoxicity
BackgroundPolybrominated diphenyl ethers (PBDEs) are widely used flame retardants that bioaccumulate in human tissues. Their neurotoxicity involves dysregulation of calcium ion (Ca(2+))signaling; however, specific mechanisms have yet to be defined.ObjectiveWe aimed to define the structure-activity relationship (SAR) for PBDEs and their metabolites toward ryanodine receptors type 1 (RyR1) and type 2 (RyR2) and to determine whether it predicts neurotoxicity.MethodsWe analyzed [3H]ryanodine binding, microsomal Ca(2+) fluxes, cellular measurements of Ca(2+) homeostasis, and neurotoxicity to define mechanisms and specificity of PBDE-mediated Ca(2+) dysregulation.ResultsPBDEs possessing two ortho-bromine substituents and lacking at least one para-bromine substituent (e.g., BDE-49) activate RyR1 and RyR2 with greater efficacy than corresponding congeners with two para-bromine substitutions (e.g., BDE-47). Addition of a methoxy group in the free para position reduces the activity of parent PBDEs. The hydroxylated BDEs 6-OH-BDE-47 and 4´-OH-BDE-49 are biphasic RyR modulators. Pretreatment of HEK293 cells (derived from human embryonic kidney cells) expressing either RyR1 or RyR2 with BDE-49 (250 nM) sensitized Ca2+ flux triggered by RyR agonists, whereas BDE-47 (250 nM) had negligible activity. The divergent activity of BDE-49, BDE-47, and 6-OH-BDE-47 toward RyRs predicted neurotoxicity in cultures of cortical neurons.ConclusionsWe found that PBDEs are potent modulators of RyR1 and RyR2. A stringent SAR at the ortho and para position determined whether a congener enhanced, inhibited, or exerted nonmonotonic actions toward RyRs. These results identify a convergent molecular target of PBDEs previously identified for noncoplanar polychlorinated biphenyls (PCBs) that predicts their cellular neurotoxicity and therefore could be a useful tool in risk assessment of PBDEs and related compounds
Cultivation of Human Corneal Endothelial Cells Isolated from Paired Donor Corneas
Consistent expansion of human corneal endothelial cells (hCECs) is critical in the development of tissue engineered endothelial constructs. However, a wide range of complex culture media, developed from different basal media have been reported in the propagation of hCECs, some with more success than others. These results are further confounded by donor-to-donor variability. The aim of this study is to evaluate four culture media in the isolation and propagation of hCECs isolated from a series of paired donor corneas in order to negate donor variability
Parametric study of EEG sensitivity to phase noise during face processing
<b>Background: </b>
The present paper examines the visual processing speed of complex objects, here faces, by mapping the relationship between object physical properties and single-trial brain responses. Measuring visual processing speed is challenging because uncontrolled physical differences that co-vary with object categories might affect brain measurements, thus biasing our speed estimates. Recently, we demonstrated that early event-related potential (ERP) differences between faces and objects are preserved even when images differ only in phase information, and amplitude spectra are equated across image categories. Here, we use a parametric design to study how early ERP to faces are shaped by phase information. Subjects performed a two-alternative force choice discrimination between two faces (Experiment 1) or textures (two control experiments). All stimuli had the same amplitude spectrum and were presented at 11 phase noise levels, varying from 0% to 100% in 10% increments, using a linear phase interpolation technique. Single-trial ERP data from each subject were analysed using a multiple linear regression model.
<b>Results: </b>
Our results show that sensitivity to phase noise in faces emerges progressively in a short time window between the P1 and the N170 ERP visual components. The sensitivity to phase noise starts at about 120–130 ms after stimulus onset and continues for another 25–40 ms. This result was robust both within and across subjects. A control experiment using pink noise textures, which had the same second-order statistics as the faces used in Experiment 1, demonstrated that the sensitivity to phase noise observed for faces cannot be explained by the presence of global image structure alone. A second control experiment used wavelet textures that were matched to the face stimuli in terms of second- and higher-order image statistics. Results from this experiment suggest that higher-order statistics of faces are necessary but not sufficient to obtain the sensitivity to phase noise function observed in response to faces.
<b>Conclusion: </b>
Our results constitute the first quantitative assessment of the time course of phase information processing by the human visual brain. We interpret our results in a framework that focuses on image statistics and single-trial analyses
Integrating isotopes and documentary evidence : dietary patterns in a late medieval and early modern mining community, Sweden
We would like to thank the Archaeological Research Laboratory, Stockholm University, Sweden and the Tandem Laboratory (Ångström Laboratory), Uppsala University, Sweden, for undertaking the analyses of stable nitrogen and carbon isotopes in both human and animal collagen samples. Also, thanks to Elin Ahlin Sundman for providing the δ13C and δ15N values for animal references from Västerås. This research (Bäckström’s PhD employment at Lund University, Sweden) was supported by the Berit Wallenberg Foundation (BWS 2010.0176) and Jakob and Johan Söderberg’s foundation. The ‘Sala project’ (excavations and analyses) has been funded by Riksens Clenodium, Jernkontoret, Birgit and Gad Rausing’s Foundation, SAU’s Research Foundation, the Royal Physiographic Society of Lund, Berit Wallenbergs Foundation, Åke Wibergs Foundation, Lars Hiertas Memory, Helge Ax:son Johnson’s Foundation and The Royal Swedish Academy of Sciences.Peer reviewedPublisher PD
A Mouse Stromal Response to Tumor Invasion Predicts Prostate and Breast Cancer Patient Survival
Primary and metastatic tumor growth induces host tissue responses that are believed to support tumor progression. Understanding the molecular changes within the tumor microenvironment during tumor progression may therefore be relevant not only for discovering potential therapeutic targets, but also for identifying putative molecular signatures that may improve tumor classification and predict clinical outcome. To selectively address stromal gene expression changes during cancer progression, we performed cDNA microarray analysis of laser-microdissected stromal cells derived from prostate intraepithelial neoplasia (PIN) and invasive cancer in a multistage model of prostate carcinogenesis. Human orthologs of genes identified in the stromal reaction to tumor progression in this mouse model were observed to be expressed in several human cancers, and to cluster prostate and breast cancer patients into groups with statistically different clinical outcomes. Univariate Cox analysis showed that overexpression of these genes is associated with shorter survival and recurrence-free periods. Taken together, our observations provide evidence that the expression signature of the stromal response to tumor invasion in a mouse tumor model can be used to probe human cancer, and to provide a powerful prognostic indicator for some of the most frequent human malignancies
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