Star Formation and Clumps in Cosmological Galaxy Simulations with Radiation Pressure Feedback

Cosmological simulations of galaxies have typically produced too many stars at early times. We study the global and morphological effects of radiation pressure (RP) in eight pairs of high-resolution cosmological galaxy formation simulations. We find that the additional feedback suppresses star formation globally by a factor of ~2. Despite this reduction, the simulations still overproduce stars by a factor of ~2 with respect to the predictions provided by abundance matching methods for halos more massive than 5E11 Msun/h (Behroozi, Wechsler & Conroy 2013). We also study the morphological impact of radiation pressure on our simulations. In simulations with RP the average number of low mass clumps falls dramatically. Only clumps with stellar masses Mclump/Mdisk <= 5% are impacted by the inclusion of RP, and RP and no-RP clump counts above this range are comparable. The inclusion of RP depresses the contrast ratios of clumps by factors of a few for clump masses less than 5% of the disk masses. For more massive clumps, the differences between and RP and no-RP simulations diminish. We note however, that the simulations analyzed have disk stellar masses below about 2E10 Msun/h. By creating mock Hubble Space Telescope observations we find that the number of clumps is slightly reduced in simulations with RP. However, since massive clumps survive the inclusion of RP and are found in our mock observations, we do not find a disagreement between simulations of our clumpy galaxies and observations of clumpy galaxies. We demonstrate that clumps found in any single gas, stellar, or mock observation image are not necessarily clumps found in another map, and that there are few clumps common to multiple maps.Comment: 13 pages, 6 figures, submitted to MNRA

Top-down, decoupled control of constitutive parameters in electromagnetic metamaterials with dielectric resonators of internal anisotropy

A meta-atom platform providing decoupled tuning for the constitutive wave parameters remains as a challenging problem, since the proposition of Pendry. Here we propose an electromagnetic meta-atom design of internal anisotropy (ε_r ≠ ε_θ), as a pathway for decoupling of the effective- permittivity ε_(eff) and permeability μ_(eff). Deriving effective parameters for anisotropic meta-atom from the first principles, and then subsequent inverse-solving the obtained decoupled solution for a target set of ε_(eff) and μ_(eff), we also achieve an analytic, top-down determination for the internal structure of a meta-atom. To realize the anisotropy from isotropic materials, a particle of spatial permittivity modulation in r or θ direction is proposed. As an application example, a matched zero index dielectric meta-atom is demonstrated, to enable the super-funneling of a 50λ-wide flux through a sub-λ slit; unharnessing the flux collection limit dictated by the λ-zone

Effect of ethnicity, dietary intake and physical activity on plasma adiponectin concentrations among Malaysian patients with type 2 diabetes mellitus

Background: The Malaysian Health and morbidity Survey (2006) reported the highest prevalence of type 2 diabetes mellitus (T2DM) among the Indian population compared to the Malay and Chinese populations. Many studies have supported the important role of adiponectin in insulin-sensitizing, which is associated with T2DM. These studies have raised a research question whether the variation in prevalence is related to the adiponectin concentrations or the lifestyle factors. Objectives: The purpose of this study is to determine whether the adiponectin concentrations differ between the Malay, Chinese and the Indian populations with T2DM. It is to investigate the association of adiponectin concentrations with ethnicity, dietary intake and physical activity too. Materials and Methods: In this cross-sectional study, a total of 210 T2DM patients with mean (SD) age of 56.73 (10.23) years were recruited from Penang, Malaysia. Data on demographic background, medical history, anthropometry (weight, height, visceral fat, percentage of body fat and waist circumference), dietary intake (3 days 24 hours diet recall) and physical activity (International Physical Activity Questionnaire) were obtained accordingly. Plasma adiponectin and routine laboratory tests (fasting blood sugar, HbA1c, total cholesterol, LDL, HDL and triglyceride) were performed according to standard procedure. Results: After adjustment for physical activity and dietary intakes, the Indian population had significantly lower adiponectin concentrations (P = 0.003) when compared with the Malay and the Chinese populations, The Indian population also had significantly higher value of HbA1c (P = 0.017) and significantly lower HDL (P = 0.013). Plasma adiponectin concentrations was significantly associated with ethnicity (P = 0.011), dietary carbohydrate (P = 0.003) and physical activity total MET score (P = 0.026), after medical history, age, sex, total cholesterol and visceral fat adjusted. However, dietary carbohydrate and physical activity did not show significantly difference among the various ethnic groups. Conclusions: In conclusion, lower concentration of adiponectin in the Indian population when compared with the Malay and the Chinese populations is not associated with lifestyle factors. The possibility of adiponectin gene polymorphism should be discussed further

Modulation of Phenol Oxidation in Cofacial Dyads

The presentation of two phenols on a xanthene backbone is akin to the tyrosine dyad (Y[subscript 730] and Y[subscript 731]) of ribonucleotide reductase. X-ray crystallography reveals that the two phenol moieties are cofacially disposed at 4.35 Å. Cyclic voltammetry reveals that phenol oxidation is modulated within the dyad, which exhibits a splitting of one-electron waves with the second oxidation of the phenol dyad occurring at larger positive potential than that of a typical phenol. In contrast, a single phenol appended to a xanthene exhibits a two-electron process, consistent with reported oxidation pathways of phenols in acetonitrile. The perturbation of the phenol potential by stacking is reminiscent of a similar effect for guanines stacked within DNA base pairs.National Institutes of Health (U.S.) (GM5R01

Zebrafish Stem/Progenitor Factor msi2b Exhibits Two Phases of Activity Mediated by Different Splice Variants

The Musashi (Msi) family of RNA-binding proteins is important in stem and differentiating cells in many species. Here, we present a zebrafish gene/protein trap line gt(msi2b-citrine)(ct) (57) (a) that expresses a Citrine fusion protein with endogenous Msi2b. Our results reveal two phases of Msi2b expression: ubiquitous expression in progenitor cells in the early embryo and later, tissue-specific expression in differentiating cells in the olfactory organ, pineal gland, and subpopulations of neurons in the central nervous system (CNS). Interestingly, this division between early and late phases is paralleled by differential expression of msi2b alternative splicing products. Whereas the full-length and long variant v3 Msi2b predominate at early stages, the later expression of variants in differentiating tissues appears to be tissue specific. Using the gt(msi2b-citrine)(ct) (57) (a), we characterized tissue-specific expression of Msi2b with cellular resolution in subsets of differentiating cells in the olfactory organ, pineal gland, CNS, and ventral neural tube. By performing transcription activator-like effectors nuclease-mediated biallelic genome editing or morpholino knockdown of Msi2b in zebrafish, our results show that early inactivation of Msi2b results in severe embryonic defects including hypertrophy of the ventricles and shortening of the body, consistent with an important role in cell proliferation and survival. Moreover, specific inactivation of Msi2b full-length indicates that this species is essential for the early role of Msi2b. This line provides a valuable tool both for live imaging of the endogenous Msi2b at subcellular resolution and manipulation of Msi2b-expressing cells

As razões para indicação de tratamento precoce em pacientes de classe II

The tendency of indicating early treatment (before growth spurt) when dealing with Angle Class II cases has been noticed, although there is no definite scientific evidence to justify such decision. The aim of this study was to identify the advantages and disadvantages to this approach and which appliances are used for this purpose. For that purpose, a questionnaire containing full records of a Class II patient was sent to two professors of each Orthodontic graduate program in Brazil (n=96, total 192), from which 107 were properly answered. Results demonstrated that the most used appliances were the headgear (80.4%), maxillary splint (50%) and Bionator (44.4%). The benefits most often quoted were increase of patient self-esteem (78.5%) and reduction in the incidence of incisors trauma (63.6%), while the main disadvantage was saturation of patient compliance (73.8%). Considering early Class II treatment, there is still no unanimity as to treating in one or two stages or in selection of appliances. However, the orthodontists should consider the physical situation of the patient, severity of cases and susceptibility of trauma to the maxillary incisors. It is crucial that updated information is given to parents, in order to justify this approach.A tendência de indicação de tratamento precoce (antes de surto de crescimento) para casos de Classe II de Angle tem sido observada, embora não haja evidência científica para embasar tal decisão. O objetivo deste estudo foi identificar as vantagens e desvantagens da indicação e quais aparelhos são usados no tratamento. Foram enviados questionários (n=192) com a documentação completa de um paciente Classe II para dois professores de cada curso de especialização em Ortodontia no Brasil, os quais 107 foram respondidos. Os resultados demonstraram que os aparelhos mais usados foram: Extra-oral (80,4%), Thurow (50,0%) e Bionator (44,4%). Foram citados como maiores vantagens: aumento de auto-estima do paciente (78,5%) e a redução da incidência de trauma nos dentes incisivos (63,6%), por outro lado a principal desvantagem citada foi a saturação de cooperação do paciente (73,8%). Considerando o tratamento precoce de Classe II não houve o consenso se a correção deveria ser realizada em duas ou em uma única fase e nem a seleção do aparelho a ser utilizado. Porém os ortodontistas deveriam levar em consideração o estado psicológico do paciente, a severidade do caso clínico e a susceptibilidade a trauma dos incisivos superiores. É importante que os responsáveis sejam esclarecidos quanto à necessidade do tratamento precoce