ACA chefs adopt a school: An evaluation

This document summarises an evaluation of a cooking in schools initiative called Chefs Adopt a School (CAAS) which is delivered by the Academy of Culinary Arts.1 At present, sessions are provided all over England from Cumbria to Cornwall subject to demand and resources (with a few sessions being delivered in Scotland too). Annually, 21,000 children take part in the initiative. Delivered by professional chefs, the programme aim is to teach children about food, food provenance, health, nutrition and cookery. The evaluation was informed by a rapid systematic review of the existing literature on cooking in schools. This research has been carried out at a time when cooking in schools is being put forward as a solution to improving diets and reducing obesity. It is currently the only evaluation of school cooking in the UK that measures outcomes that impact on health, such as: eating behaviour, cooking confidence and confidence asking for fruit, vegetables and ingredients at home. As such, it can inform future UK school cooking initiative interventions and evaluations. It also highlights the need to incorporate evaluation into school cooking initiatives, as findings provide valuable information necessary to fine tune an intervention. In the core programme, chefs link with local schools, usually primary, where they deliver 2-3 sessions to one year group within a school. This process is then repeated each year. Key issues covered include hygiene, healthy eating, an appreciation of food through the senses (particularly taste) and practical cooking/food preparation. The first session covers healthy eating and the sensory appreciation of food while the second and third sessions are practical

Revisiting the Hubble sequence in the SDSS DR7 spectroscopic sample: a publicly available bayesian automated classification

We present an automated morphological classification in 4 types (E,S0,Sab,Scd) of ~700.000 galaxies from the SDSS DR7 spectroscopic sample based on support vector machines. The main new property of the classification is that we associate to each galaxy a probability of being in the four morphological classes instead of assigning a single class. The classification is therefore better adapted to nature where we expect a continuos transition between different morphological types. The algorithm is trained with a visual classification and then compared to several independent visual classifications including the Galaxy Zoo first release catalog. We find a very good correlation between the automated classification and classical visual ones. The compiled catalog is intended for use in different applications and can be downloaded at http://gepicom04.obspm.fr/sdss_morphology/Morphology_2010.html and soon from the CasJobs database.Comment: A&A in press, english corrections from language editor adde

Galaxy size trends as a consequence of cosmology

We show that recently documented trends in galaxy sizes with mass and redshift can be understood in terms of the influence of underlying cosmic evolution; a holistic view which is complimentary to interpretations involving the accumulation of discreet evolutionary processes acting on individual objects. Using standard cosmology theory, supported with results from the Millennium simulations, we derive expected size trends for collapsed cosmic structures, emphasising the important distinction between these trends and the assembly paths of individual regions. We then argue that the observed variation in the stellar mass content of these structures can be understood to first order in terms of natural limitations of cooling and feedback. But whilst these relative masses vary by orders of magnitude, galaxy and host radii have been found to correlate linearly. We explain how these two aspects will lead to galaxy sizes that closely follow observed trends and their evolution, comparing directly with the COSMOS and SDSS surveys. Thus we conclude that the observed minimum radius for galaxies, the evolving trend in size as a function of mass for intermediate systems, and the observed increase in the sizes of massive galaxies, may all be considered an emergent consequence of the cosmic expansion.Comment: 14 pages, 13 figures. Accepted by MNRA

Comparing PyMorph and SDSS photometry. II. The differences are more than semantics and are not dominated by intracluster light

The Sloan Digital Sky Survey pipeline photometry underestimates the brightnesses of the most luminous galaxies. This is mainly because (i) the SDSS overestimates the sky background and (ii) single or two-component Sersic-based models better fit the surface brightness profile of galaxies, especially at high luminosities, than does the de Vaucouleurs model used by the SDSS pipeline. We use the PyMorph photometric reductions to isolate effect (ii) and show that it is the same in the full sample as in small group environments, and for satellites in the most massive clusters as well. None of these are expected to be significantly affected by intracluster light (ICL). We only see an additional effect for centrals in the most massive halos, but we argue that even this is not dominated by ICL. Hence, for the vast majority of galaxies, the differences between PyMorph and SDSS pipeline photometry cannot be ascribed to the semantics of whether or not one includes the ICL when describing the stellar mass of massive galaxies. Rather, they likely reflect differences in star formation or assembly histories. Failure to account for the SDSS underestimate has significantly biased most previous estimates of the SDSS luminosity and stellar mass functions, and therefore Halo Model estimates of the z ~ 0.1 relation between the mass of a halo and that of the galaxy at its center. We also show that when one studies correlations, at fixed group mass, with a quantity which was not used to define the groups, then selection effects appear. We show why such effects arise, and should not be mistaken for physical effects.Comment: 15 pages, 17 figures, accepted for publication in MNRAS. The PyMorph luminosities and stellar masses are available at https://www.physics.upenn.edu/~ameert/SDSS_PhotDec

The high mass end of the stellar mass function: Dependence on stellar population models and agreement between fits to the light profile

We quantify the systematic effects on the stellar mass function which arise from assumptions about the stellar population, as well as how one fits the light profiles of the most luminous galaxies at z ~ 0.1. When comparing results from the literature, we are careful to separate out these effects. Our analysis shows that while systematics in the estimated comoving number density which arise from different treatments of the stellar population remain of order < 0.5 dex, systematics in photometry are now about 0.1 dex, despite recent claims in the literature. Compared to these more recent analyses, previous work based on Sloan Digital Sky Survey (SDSS) pipeline photometry leads to underestimates of rho_*(> M_*) by factors of 3-10 in the mass range 10^11 - 10^11.6 M_Sun, but up to a factor of 100 at higher stellar masses. This impacts studies which match massive galaxies to dark matter halos. Although systematics which arise from different treatments of the stellar population remain of order < 0.5 dex, our finding that systematics in photometry now amount to only about 0.1 dex in the stellar mass density is a significant improvement with respect to a decade ago. Our results highlight the importance of using the same stellar population and photometric models whenever low and high redshift samples are compared.Comment: 18 pages, 17 figures, accepted for publication in MNRAS. The PyMorph luminosities and stellar masses are available at https://www.physics.upenn.edu/~ameert/SDSS_PhotDec

Soft clustering analysis of galaxy morphologies: A worked example with SDSS

Context: The huge and still rapidly growing amount of galaxies in modern sky surveys raises the need of an automated and objective classification method. Unsupervised learning algorithms are of particular interest, since they discover classes automatically. Aims: We briefly discuss the pitfalls of oversimplified classification methods and outline an alternative approach called "clustering analysis". Methods: We categorise different classification methods according to their capabilities. Based on this categorisation, we present a probabilistic classification algorithm that automatically detects the optimal classes preferred by the data. We explore the reliability of this algorithm in systematic tests. Using a small sample of bright galaxies from the SDSS, we demonstrate the performance of this algorithm in practice. We are able to disentangle the problems of classification and parametrisation of galaxy morphologies in this case. Results: We give physical arguments that a probabilistic classification scheme is necessary. The algorithm we present produces reasonable morphological classes and object-to-class assignments without any prior assumptions. Conclusions: There are sophisticated automated classification algorithms that meet all necessary requirements, but a lot of work is still needed on the interpretation of the results.Comment: 18 pages, 19 figures, 2 tables, submitted to A

Matrix factorizations for quantum complete intersections

We introduce twisted matrix factorizations for quantum complete intersections of codimension two. For such an algebra, we show that in a given dimension, almost all the indecomposable modules with bounded minimal projective resolutions correspond to such matrix factorizations.Comment: 13 page

Physiological responses of adipose tissue to different models of physical activity and inactivity

Childhood is a critical time of growth, and decisions made during this time lead to positive and negative health consequences, specifically pertaining to adiposity. There is convincing evidence that children who are overweight and obese are at higher risk for adult obesity and risk factors associated with obesity for their whole life course. Puberty is a critical time of adipose tissue expansion, and it is accepted by most that this is the age where the number of adipocytes is set for adulthood. Further it is believed that before puberty, adipose tissue expands by hyperplasia, while after puberty, adipose tissue expands by hypertrophy. The time leading up to puberty represents a critical time. Yet, little is known about the interaction between age, physical activity, and adipose tissue expansion in young, growing animals. Thus, I employed a unique model of childhood obesity to test whether: 1) seven days of decreased physical activity (wheel lock) in 49-56 day old rats and 70-77 day old rats would result in gains in visceral adipose mass seen in age-matched sedentary rats concurrent with an increase in adipocyte size and inflammatory mRNA expression (Chapter 2), and 2) glucocorticoid block would attenuate the visceral adipose depot gains seen with wheel lock in rats at sexual maturity (Chapter 3). Here, I present evidence that the age at which wheel lock occurs influences visceral adipose tissue growth and propose a mechanism for this growth at two ages of pre-pubertal growth (49-56 days of age and 70-77 days of age). Specifically, rats that undergo wheel lock for 7 days at 49-56 days of age show no differences in total body mass, mean adipocyte diameter, or mass of omental, epididymal, and perirenal adipose tissue depots compared to rats that remained physically active. However, rats that undergo wheel lock for 7 days at 70-77 days of age have an increased rate of body mass, fat mass, and % body fat gained and have increased depot mass and total number of adipocytes in epididymal and perirenal adipose tissue,

Letter to Sonora Dodd from The A. M. Davis Company, May 23, 1911

Letter to Sonora Dodd from the A. M. Davis Company, with envelope.https://digitalcommons.whitworth.edu/fathers-day-correspondence/1003/thumbnail.jp