Hidradenitis suppurativa:From pathogenesis to emerging treatment options

Hidradenitis suppurativa (HS) is a chronic skin disease that is characterized by inflammation of the hair follicles. The cause of HS is largely unknown and the disease remains difficult to treat. Mrs. Janine Dickinson-Blok studied the pathogenesis of HS and the efficacy of existing and emerging therapies. In the first part of her thesis she focused on the pathogenesis of HS. She demonstrated that fragility of hair follicles is not a hallmark of HS, as was previously described by others. She did find that a specific protein called integrine α6β4 is highly present at the sebaceous glands of HS patients. This protein may contribute to activation of the immune system and consequently to an exacerbation of the disease. Additionally, she described that patients with Down syndrome possibly have a functional deficiency of an enzyme called gamma-secretase. This could raise the risk for the development of HS in this patient group. The second part focused on treatment of HS. Based on a systematic review she concluded that the use of specific inhibitors of the immune system, so-called TNF-α inhibitors, is the best medical treatment of HS to date. Furthermore, she showed that ustekinumab (an immune therapy drug) is effective in the majority of a group HS patients. Additionally, she described a new surgical technique for moderate to severe HS (the Skin Tissue sparing Excision with Electrosurgical Peeling procedure). Finally, she concluded that in most cases the combination of surgery with systemic agents is mandatory in order to prevent new inflammatory lesions

PO-0954 Click! Engaging Children In Research About Their Lives: Experiences Of Using Photo-elicitation From England, Australia And New Zealand

Background and aims. Engaging children in research about their lives is an essential component of providing excellent health care services. Utilising participatory, visual/arts-based approaches such as photo-elicitation (PE) can extend opportunities for children to reflect on and talk about their lives. This paper aims to explore the use of, benefits and issues associated with using PE with children. Methods. PE is a participatory, qualitative method that does not rely on high levels of verbal or written literacy and which creates equitable conditions for children’s engagement in research. Within a broad brief, children are asked to take topic-related photos. Apart from safety/privacy related guidance about where it might not be appropriate to take photographs, the children are free to take any image that has meaning to them. The children then select the images they wish to discuss and the researcher literally has to ‘follow’ the children’s data and adopt a flexible approach to the conversational interview. Results. Reflecting on our experience with PE we note how the quality of discussion is enhanced and intriguing and unexpected insights into children’s lives are revealed. What children choose to photograph or omit can create interesting tensions; these and other lessons will be shared along with exemplar photographs and stories. Conclusions. Although PE provides considerable opportunities and benefits, it is challenging research to be part of and requires skilled researchers to ensure children are safe during research engagement and that the data provides a robust depth of insight into their lives

Breaking the Curve with CANDELS: A Bayesian Approach to Reveal the Non-Universality of the Dust-Attenuation Law at High Redshift

Dust attenuation affects nearly all observational aspects of galaxy evolution, yet very little is known about the form of the dust-attenuation law in the distant Universe. Here, we model the spectral energy distributions (SEDs) of galaxies at z = 1.5--3 from CANDELS with rest-frame UV to near-IR imaging under different assumptions about the dust law, and compare the amount of inferred attenuated light with the observed infrared (IR) luminosities. Some individual galaxies show strong Bayesian evidence in preference of one dust law over another, and this preference agrees with their observed location on the plane of infrared excess (IRX, $L_{\text{TIR}}/L_{\text{UV}}$) and UV slope ($\beta$). We generalize the shape of the dust law with an empirical model, $A_{\lambda,\delta}=E(B-V)\ k_\lambda\ (\lambda/\lambda_V)^\delta$ where $k_\lambda$ is the dust law of Calzetti et al. (2000), and show that there exists a correlation between the color excess ${E(B-V)}$ and tilt $\delta$ with ${\delta=(0.62\pm0.05)\log(E(B-V))}$+ ${(0.26~\pm~0.02)}$. Galaxies with high color excess have a shallower, starburst-like law, and those with low color excess have a steeper, SMC-like law. Surprisingly, the galaxies in our sample show no correlation between the shape of the dust law and stellar mass, star-formation rate, or $\beta$. The change in the dust law with color excess is consistent with a model where attenuation is caused by by scattering, a mixed star-dust geometry, and/or trends with stellar population age, metallicity, and dust grain size. This rest-frame UV-to-near-IR method shows potential to constrain the dust law at even higher ($z>3$) redshifts.Comment: 20 pages, 18 figures, resubmitted to Ap

Adiposity, reproductive and metabolic health, and activity levels in zoo Asian elephant (Elephas maximus)

Acknowledgements The authors thank Dr Barbara Gower, Maryellen Williams, Heather Hunter and Cindy Zeng at the UAB NORC's Metabolism Core for their assistance with hormone assays and mass spectroscopy, and Dr Katie Edwards, Steve Paris and Niki Boisseau at SCBI for inflammatory and estradiol analyses. The authors thank African Lion Safari, Cincinnati Zoo & Botanical Garden, Columbus Zoo & Aquarium, Fort Worth Zoo, Little Rock Zoo, Oklahoma City Zoo, Oregon Zoo, Santa Barbara Zoo and Saint Louis Zoo for their participation in this study. Specifically, a very big thank you to the zoos' elephant keepers and elephants, who made this study possible and enjoyable. A special thank you to the Birmingham Zoo and Pat Flora and his elephant team for their continued support, help and input with method improvement. Funding This work was supported in part by the Smithsonian Institution, the UAB Nutrition Obesity Research Center (P30DK056336), the Diabetes Research Center (P30DK079626), the Nathan Shock Center on Aging (P30AG050886), and the National Heart, Lung, and Blood Institute (T32HL105349 to D.E.C.). Deposited in PMC for release after 12 months.Peer reviewedPublisher PD

Star formation rates and masses of z ~ 2 galaxies from multicolour photometry

Fitting synthetic spectral energy distributions (SED) to the multi-band photometry of galaxies to derive their star formation rates (SFR), stellar masses, ages, etc. requires making a priori assumptions about their star formation histories (SFH). A widely adopted parameterization of the SFH, the so-called tau-models where SFR goes as e^{-t/tau) is shown to lead to unrealistically low ages when applied to star forming galaxies at z ~ 2, a problem shared by other SFHs when the age is left as a free parameter in the fitting. This happens because the SED of such galaxies, at all wavelengths, is dominated by their youngest stellar populations, which outshine the older ones. Thus, the SED of such galaxies conveys little information on the beginning of star formation. To cope with this problem, we explore a variety of SFHs, such as constant SFR and inverted-tau models - with SFR as e^{+t/tau) - along with various priors on age, including assuming that star formation started at high redshift in all the galaxies. We find that inverted-tau models with such latter assumption give SFRs and extinctions in excellent agreement with the values derived using only the UV part of the SED. These models are also shown to accurately recover the SFRs and masses of mock galaxies at z ~ 2 constructed from semi-analytic models. All other explored SFH templates do not fulfil these two test. In particular, direct-tau models with unconstrained age in the fitting procedure overstimate SFRs and underestimate stellar mass, and would exacerbate an apparent mismatch between the cosmic evolution of the volume densities of SFR and stellar mass. We conclude that for high-redshift star forming galaxies an exponentially increasing SFR with a high formation redshift is preferable to other forms of the SFH so far adopted in the literature.Comment: 19 pages, 28 figures, Monthly Notices of the Royal Astronomical Society in pres

A Critical Assessment of Stellar Mass Measurement Methods

In this paper we perform a comprehensive study of the main sources of random and systematic errors in stellar mass measurement for galaxies using their Spectral Energy Distributions (SEDs). We use mock galaxy catalogs with simulated multi-waveband photometry (from U-band to mid-infrared) and known redshift, stellar mass, age and extinction for individual galaxies. Given different parameters affecting stellar mass measurement (photometric S/N ratios, SED fitting errors, systematic effects, the inherent degeneracies and correlated errors), we formulated different simulated galaxy catalogs to quantify these effects individually. We studied the sensitivity of stellar mass estimates to the codes/methods used, population synthesis models, star formation histories, nebular emission line contributions, photometric uncertainties, extinction and age. For each simulated galaxy, the difference between the input stellar masses and those estimated using different simulation catalogs, $\Delta\log(M)$, was calculated and used to identify the most fundamental parameters affecting stellar masses. We measured different components of the error budget, with the results listed as follows: (1). no significant bias was found among different codes/methods, with all having comparable scatter; (2). A source of error is found to be due to photometric uncertainties and low resolution in age and extinction grids; (3). The median of stellar masses among different methods provides a stable measure of the mass associated with any given galaxy; (4). The deviations in stellar mass strongly correlate with those in age, with a weaker correlation with extinction; (5). the scatter in the stellar masses due to free parameters are quantified, with the sensitivity of the stellar mass to both the population synthesis codes and inclusion of nebular emission lines studied.Comment: 33 pages, 20 Figures, Accepted for publication in Astrophysical Journa

Paediatric lymphoedema : An audit of patients seen by the paediatric and primary lymphoedema group of vascular European Reference Network (VASCERN)

Little is known about the overall prevalence of lymphoedema in children and the types of paediatric lymphoedema seen by specialist centres. Therefore, this study was aimed to provide a profile of children with primary or secondary lymphoedema seen by the expert centres of the paediatric and primary lymphoedema working group (PPL-WG) of VASCERN and to compare the profile between the different countries.A retrospective review of all children (aged up to 18 years) seen for the first time by the expert centres over one year (2019) was carried out. Lymphoedema-, patient- and genetics-related data was collected and described for the whole group and compared between the different European countries/UK.In 2019, a total of 181 new children were seen by eight expert centres. For primary lymphoedema, the phenotype was based on the St George's classification of lymphatic anomalies. The percentages diagnosed according to each category were: 7.2% for syndromic lymphoedema, 2.8% for systemic/visceral involvement, 30.4% for congenital, 35.9% for late-onset lymphoedema and 19.3% for vascular/lymphatic malformations. 4.4% had secondary lymphoedema. Nearly 10% of all children had had at least one episode of cellulitis. The median delay from onset of symptoms to being seen by an expert centre was 2.4 years. In 44.4% of the children with primary lymphoedema a genetic test was performed, of which 35.8% resulted in a molecular diagnosis. Across the different centres, there was a wide variety in distribution of the different categories of paediatric lymphoedema diagnosed and the frequency of genetic testing.In conclusion, this paper has demonstrated that there is a large delay between the onset of paediatric lymphoedema and the first visit in the expert centres and that an episode of cellulitis is a relatively common complication. Diagnostic variation across the centres may reflect different referral criteria. Access to genetic testing was limited in some centres. It is recommended that these issues are addressed in the future work of the PPL-WG to improve the referral to the expert centres and the consistency in service provision for paediatric lymphoedema in Europe.Peer reviewe