Deriving star formation histories: Inverting HR diagrams through a variational calculus maximum likelihood method

We introduce a new method for solving maximum likelihood problems through variational calculus, and apply it to the case of recovering an unknown star formation history, $SFR(t)$, from a resulting HR diagram. This approach allows a totally non-parametric solution which has the advantage of requiring no initial assumptions on the $SFR(t)$. As a full maximum likelihood statistical model is used, we take advantage of all the information available in the HR diagram, rather than concentrating on particular features such as turn off points or luminosity functions. We test the method using a series of synthetic HR diagrams produced from known $SFR(t)$, and find it to be quite successful under noise conditions comparable to those present in current observations. At this point we restrict the analysis to situations where the metallicity of the system is known, as is the case with the resolved populations of the dwarf spheroidal companions to the Milky Way or the solar neighbourhood Hipparcos data. We also include tests to quantify the way uncertainties in the assumed metallicity, binary fraction and IMF affect our inferences.Comment: 16 pages including 12 figures. Accepted for publication in MNRAS, appendix adde

Non-parametric star formation histories for 5 dwarf spheroidal galaxies of the local group

We use recent HST colour-magnitude diagrams of the resolved stellar populations of a sample of local dSph galaxies (Carina, LeoI, LeoII, Ursa Minor and Draco) to infer the star formation histories of these systems, $SFR(t)$. Applying a new variational calculus maximum likelihood method which includes a full Bayesian analysis and allows a non-parametric estimate of the function one is solving for, we infer the star formation histories of the systems studied. This method has the advantage of yielding an objective answer, as one need not assume {\it a priori} the form of the function one is trying to recover. The results are checked independently using Saha's $W$ statistic. The total luminosities of the systems are used to normalize the results into physical units and derive SN type II rates. We derive the luminosity weighted mean star formation history of this sample of galaxies.Comment: 14 pages including 7 figures. Accepted to MNRA

Mjanja Production Portfolio: Finding a Path as a Post-COVID Music Technologist

In order to be a leader in the field, the one needs to dedicate some time to cultivating the skills, connections, and behaviors exhibited by the leaders in the music industry. In order to accomplish this, the author positioned himself to work on original compositions and collaborations that would enhance his pre-existing skillset. Throughout the year, this project took many forms as a result of a number of factors – changing interests, available resources, and the global pandemic that affected every single person in 2020. The author compiled the best of those compositions into a portfolio that highlights the strong suits of his skillset.https://remix.berklee.edu/graduate-studies-production-technology/1194/thumbnail.jp

Sex and Symbol in Andalusian Comic Poetry

This paper presents a series of comic coplas written for public performance during carnival in agrotown in Seville Province, Andalusia. The songs date from the 1940s to the 1990s. Their production is a male prerogative: composed by male «maestros», they are sung by male troubadours. This is a specifically Andalusian genre of social burlesque that takes woman as its subject: wives, lovers, mothers-in-law. The lyrics use erotic imagery, genital tropes, and obscene allegories to covey the prevailing masculine ideology concerning sexuality, male-female politics, and domestic relations. The paper concludes with a brief interpretation of the style and symbolism of the Andalusian carnivalesque, borrowing from the critic Bakhtin's concept of «grotesque realism».Este artículo presenta unas coplas de chirigota compuestas por desempeño público durante el carnaval en una villa agraria de la provincia de Sevilla. Las coplas están compuestas entre los años 40 y 90. Representando un género folklórico burlesco social específicamente andaluz, las coplas son una prerrogativa solamente masculina, escritas por los «maestros de murga» e interpretadas por cantores masculinos («murguistas»). Basadas en imágenes eróticas, metáforas genitales y alegorías obscenas, las letras comunican una ideología masculina sobre la sexualidad, las relaciones entre el hombre y la mujer y la domesticidad. Concluye el artículo con una breve interpretación de las letras de chirigota, basándose el análisis en el concepto de «realismo grotesco» propuesto por el crítico ruso Bakhtin

Physicians & Surgeons - Malpractice - Standard of Care

The Supreme Judicial Court of Massachusetts has held that the locality rule in regard to the standard of care of physicians and surgeons is no longer applicable. Brune v. Belinkoff, ___ Mass. ___, 235 N.E.2d 793 (1968)