Sree Oh

The SAMI Galaxy Survey: revisiting galaxy classification through high-order stellar kinematics

Recent cosmological hydrodynamical simulations suggest that integral field spectroscopy can connect the high-order stellar kinematic moments h_3 (~skewness) and h_4 (~kurtosis) in galaxies to their cosmological assembly history. Here, we assess these results by measuring the stellar kinematics on a sample of 315 galaxies, without a morphological selection, using two-dimensional integral field data from the SAMI Galaxy Survey. Proxies for the spin parameter (λ_(R_e)) and ellipticity (e_e) are used to separate fast and slow rotators; there exists a good correspondence to regular and non-regular rotators, respectively, as also seen in earlier studies. We confirm that regular rotators show a strong h_3 versus V/σ anti-correlation, whereas quasi-regular and non-regular rotators show a more vertical relation in h_3 and V/σ. Motivated by recent cosmological simulations, we develop an alternative approach to kinematically classify galaxies from their individual h_3 versus V/σ signatures. Within the SAMI Galaxy Survey, we identify five classes of high-order stellar kinematic signatures using Gaussian mixture models. Class 1 corresponds to slow rotators, whereas Classes 2–5 correspond to fast rotators. We find that galaxies with similar λ_(R_e) - e_e values can show distinctly different h_3 - V/σ signatures. Class 5 objects are previously unidentified fast rotators that show a weak h_3 versus V/σ anti-correlation. From simulations, these objects are predicted to be disk-less galaxies formed by gas-poor mergers. From morphological examination, however, there is evidence for large stellar disks. Instead, Class 5 objects are more likely disturbed galaxies, have counter-rotating bulges, or bars in edge-on galaxies. Finally, we interpret the strong anti-correlation in h_3 versus V/σ as evidence for disks in most fast rotators, suggesting a dearth of gas-poor mergers among fast rotators.

Recessive dystrophic epidermolysis bullosa associated with dilated cardiomyopathy.

congenital FM. The patient was treated with mild-potency topical corticosteroids and, after 2 months, we observed a resolution of the lesion. Follicular mucinosis is an epithelial reaction pattern characterized by the accumulation of mucin within hair follicles. After the initial report by Pinkus, several publications proposed the existence of two main types of FM. The first type of FM (type I FM) occurs mostly in children and young adults, in the absence of cutaneous or extracutaneous disorders, and shows localized lesions with a tendency to resolve within 2 months to 2 years. The second type (type II FM) occurs in older patients and is associated with mycosis fungoides or Sézary syndrome. Follicular mucinosis is rare in the paediatric population. Most of the cases have a benign prognosis, and undergo a spontaneous resolution. However, cases have been reported in association with Hodgkin disease, other lymphomas and leukaemias. In our case, the favourable evolution under local corticosteroid therapy and the absence of recurrence after 6 months of follow-up favours type I FM. However, we cannot be sure that this evolution has been induced by corticosteroids; it also could be a spontaneous resolution. Nevertheless, a clinical follow-up is still ongoing as malignancies have also been associated with paediatric cases of FM and there are no clear-cut criteria to initially differentiate type I from type II FM. To the best of our knowledge, this is the first reported case of congenital follicular mucinosis.

COL7A1 mutational analysis in Korean patients with dystrophic epidermolysis bullosa

Dystrophic epidermolysis bullosa (DEB) is an inherited blistering skin disorder, characterized by mucocutaneous blistering, scarring and nail dystrophy following minor trauma. DEB is caused by mutations in the COL7A1 gene and occurs either as an autosomal dominant (DDEB, MIM 131750) or as a recessive (RDEB, MIM 226600) trait. The phenotypic variability results from the different types of mutations in COL7A1 and their positions within the gene. In most cases, RDEB has a more severe clinical presentation. The most severe type of DEB, the recessive Hallopeau–Siemens variant (HS-RDEB), is caused by the presence of mutations that lead to premature termination codons (PTCs) in both alleles, whereas the autosomal dominant cases are frequently caused by heterozygous glycine substitutions (GSs) within the collagenous triple helix. To date, more than 500 different mutations of COL7A1 have been reported. In this study, mutational analysis was performed in 18 distinct Korean families with DEB, and a computational study of each mutation was carried out.

Timing the evolution of quiescent and star-forming local galaxies

Constraining the star formation histories (SFHs) of individual galaxies is crucial to understanding the mechanisms that regulate their evolution. Here, we combine multi-wavelength (ultraviolet, optical, and infrared) measurements of a very large sample of galaxies (~230,000) at z<0.16, with physically motivated models of galaxy spectral energy distributions to extract constraints on galaxy physical parameters (such as stellar mass and star formation rate) as well as individual SFHs. In particular, we set constraints on the timescales in which galaxies form a certain percentage of their total stellar mass (namely, 10, 50 and 90%). The large statistics allows us to average such measurements over different populations of galaxies (quiescent and star-forming) and in narrow ranges of stellar mass. As in the downsizing scenario, we confirm that low-mass galaxies have more extended SFHs than high-mass galaxies. We also find that at the same observed stellar mass, galaxies that are now quiescent evolve more rapidly than galaxies that are currently still forming stars. This suggests that stellar mass is not the only driver of galaxy evolution, but plays along with other factors such as merger events and other environmental effects.

A novel homozygous keratin 14 mutation in a patient with autosomal recessive epidermolysis bullosa simplex and squamous cell carcinoma of the tongue

Epidermolysis bullosa simplex (EBS) is a group of inherited skin disorders characterized by lysis of basal keratinocytes leading to the development of intraepidermal blisters from mild trauma. 1 EBS is known to be an autosomal dominant disorder; however, a few recessive cases have been reported. In EBS, the risk of cutaneous malignancy is not higher than in the normal population. 2 We present a patient who showed generalized blistering after minor trauma followed by brownish reticulated hyperpigmentation and squamous cell carcinoma of the tongue. We identified a novel homozygous KRT14 mutation (E392X) inherited in an autosomal recessive fashion.

Coccygeal polypoid eccrine naevus

1 Friedman SJ, Butler DF. Syringoma presenting as milia. J Am Acad Dermatol 1987; 16:310–14. 2 Wang KH, Chu JS, Lin YH et al. Milium-like syringoma: a case study on histogenesis. J Cutan Pathol 2004; 31:336–40. 3 Zhu WY. Syringoma associated with milium-like lesions. J Am Acad Dermatol 1988; 19:360–1. 4 Butterworth T, Strean LP, Beerman H, Wood MG. Syringoma and mongolism. Arch Dermatol 1964; 90:482–7. 5 Maroon M, Tyler W, Marks VJ. Calcinosis cutis associated with syringomas: a transepidermal elimination disorder in a patient with Down syndrome. J Am Acad Dermatol 1990; 23:372–5. 6 Kanzaki T, Nakajima M. Milialike idiopathic calcinosis cutis and syringoma in Down’s syndrome. J Dermatol 1991; 18:616–68. 7 Schepis C, Siragusa M, Palazzo R et al. Perforating milia-like idiopathic calcinosis cutis and periorbital syringomas in a girl with Down syndrome. Pediatr Dermatol 1994; 11:258–60. 8 Schepis C, Siragusa M, Palazzo R et al. Milia-like idiopathic calcinosis cutis: an unusual dermatosis associated with Down syndrome. Br J Dermatol 1996; 134:143–6. 9 Katoh N, Okabayashi K, Wakabayashi S et al. Dystrophic calcinosis of the penis. J Dermatol 1993; 20:114–17. 10 Wilkinson TM, Mizelle CB, Morrell DS. Multiple milia-like dermal papules. Pediatr Dermatol 2004; 21:269–71.

The SAMI galaxy survey: galaxy interactions and kinematic anomalies in Abell 119

Galaxy mergers are important events that can determine the fate of a galaxy by changing its morphology, star formation activity and mass growth. Merger systems have commonly been identified from their disturbed morphologies, and we now can employ integral field spectroscopy to detect and analyze the impact of mergers on stellar kinematics as well. We visually classified galaxy morphology using deep images (µ_r = 28 mag arcsec^(-2)) taken by the Blanco 4 m telescope at the Cerro Tololo Inter-American Observatory. In this paper we investigate 63 bright (M_r < -19.3) spectroscopically selected galaxies in Abell 119, of which 53 are early type and 20 show a disturbed morphology by visual inspection. A misalignment between the major axes in the photometric image and the kinematic map is conspicuous in morphologically disturbed galaxies. Our sample is dominated by early-type galaxies, yet it shows a surprisingly tight Tully–Fisher relation except for the morphologically disturbed galaxies which show large deviations. Three out of the eight slow rotators in our sample are morphologically disturbed. The morphologically disturbed galaxies are generally more asymmetric, visually as well as kinematically. Our findings suggest that galaxy interactions, including mergers and perhaps fly-bys, play an important role in determining the orientation and magnitude of a galaxys angular momentum.

The demographics of galactic bulges in the SDSS database

We present a new database of our two-dimensional bulge-disk decompositions for 14,233 galaxies drawn from SDSS DR12 in order to examine the properties of bulges residing in the local universe (

Compound heterozygosity for a premature termination codon and missense mutation in the exon 10 of the uroporphyrinogen III cosynthase gene causes a severe phenotype of congenital erythropoietic porphyria

0.005 < z < 0.05

Color Dispersion as an Indicator of Stellar Population Complexity: Insights from the Pixel Color–Magnitude Diagrams of 32 Bright Galaxies in Abell 1139 and Abell 2589

). We performed decompositions in