Borel complexity of sets of normal numbers via generic points in subshifts with specification

We study the Borel complexity of sets of normal numbers in several numeration systems. Taking a dynamical point of view, we offer a unified treatment for continued fraction expansions and base $r$ expansions, and their various generalisations: generalised L\"uroth series expansions and $\beta$-expansions. In fact, we consider subshifts over a countable alphabet generated by all possible expansions of numbers in $[0,1)$. Then normal numbers correspond to generic points of shift-invariant measures. It turns out that for these subshifts the set of generic points for a shift-invariant probability measure is precisely at the third level of the Borel hierarchy (it is a $\Pi^0_3$-complete set, meaning that it is a countable intersection of $F_\sigma$-sets, but it is not possible to write it as a countable union of $G_\delta$-sets). We also solve a problem of Sharkovsky--Sivak on the Borel complexity of the basin of statistical attraction. The crucial dynamical feature we need is a feeble form of specification. All expansions named above generate subshifts with this property. Hence the sets of normal numbers under consideration are $\Pi^0_3$-complete.Comment: A talk explaining this paper may be found at https://www.youtube.com/watch?v=g9va0ZzVIj

Opportunities and Obstacles in Adoption of Biodiversity-Enhancing Features on California Farms

The USDA National Organic Program requires the conservation of biodiversity and the maintenance or improvement of natural resources on organic farms. On-farm biodiversity-enhancing features such as border plantings can provide many of these ecosystem services. However, which practices farmers currently use to manage non-cropped edges, why and how they use these practices, and how subsidies and technical assistance affect farmers’ ability and willingness to manage farm edges for biodiversity are little studied topics. Our study set out to identify the range of practices currently used to manage non-cropped field edges, roadsides, pond edges, and banks of permanent watercourses (sloughs, canals, ditches) in a case study area in California. Secondary objectives were to gauge local farmers’ awareness of planted hedgerows and vegetated waterways and to gather preliminary information about the range of incentives and constraints to installing such features

Estimating direct and indirect rebound effects for UK households

Energy efficiency improvements by households lead to rebound effects that offset the potential energy and emissions savings. Direct rebound effects result from increased demand for cheaper energy services, while indirect rebound effects result from increased demand for other goods and services that also require energy to provide. Research to date has focused upon the former, but both are important for climate change. This study estimates the combined direct and indirect rebound effects from seven measures that improve the energy efficiency of UK dwellings. The methodology is based upon estimates of the income elasticity and greenhouse gas (GHG) intensity of 16 categories of household goods and services, and allows for the embodied emissions of the energy efficiency measures themselves. Rebound effects are measured in GHG terms and relate to the adoption of these measures by an average UK household. The study finds that the rebound effects from these measures are typically in the range 5-15% and arise mostly from indirect effects. This is largely because expenditure on gas and electricity is more GHG-intensive than expenditure on other goods and services. However, the anticipated shift towards a low carbon electricity system in the UK may lead to much larger rebound effects

A Fresh Look at Energy, Materials, and Labor in Agriculture

An understanding of agriculture's energy, material, and labor requirements is essential for achieving economic and ecological sustainability, and for assessing the effectiveness of relevant policy decisions (biofuel subsidies, regulations, labeling, etc.). Previous studies of energy, materials, and labor use in farming have been based on either unverified voluntary reporting or test plots, rather than on the high-resolution measurements of mass and energy flows. Here we present a recursive analysis of 1.25 million data points describing in unprecedented detail the resource transactions on a 60 ha farm functioning for over 6 years. This analysis highlights the importance of accounting for all types of materials, as well as capital equipment, non-field labor, and commuting. The superior energy efficiency of the farm's energy-saving methods, including green manure, crop rotation, composting, and short-duration grazing -- compared with conventional methods -- persists even when the higher labor requirements are taken into account. One of the farm's methods, however -- the use of horses for traction -- is shown to be highly inefficient compared with mechanical tractors

The TransPacific Gaze and Physical Cultural Studies: The consumption, experience and meaning of hip hop culture among New Zealand youth

As recentes análises acadêmicas da popularidade global do hip hop tem focado no seu papel em definir e expressar formas particulares de identidade. Entretanto, coincidindo com esse interesse estão as preocupações tanto de acadêmicos quanto políticos sobre aspectos específicos de alguns hip hop tem sido descritos como sendo: “materialista, misógino, homofóbico, racista, vulgar e violento” (Chang, 2007: 58). Consequentemente, visões públicas influenciadas pela mídia e por políticos tem levantado preocupações e até culpa direta ao hip hop por problemas sociais como gangues, atitudes negativas contra as mulheres e crime violento. Assim, temos uma forma popular global de cultura física que pode ser elemento chave da identidade e estilos de vida dos jovens contemporâneos; mas cada um tem também rotulado não apenas como uma ameaça, mas um potencial perigo para a sociedade. Raramente são os pontos positivos reconhecidos, particularmente aqueles que fazem parte de programas para jovens. Esse estudo examina como a cultura hip hop global/americana tem se manifestado na cultura jovem da Nova Zelândia, incluindo como ela influencia na aparência, comportamento, atividade física, esporte, moda, consumo e educação. A questão mais ampla dessa pesquisa se foca em: como a juventude da Nova Zelândia define, consome e dá sentido a cultura hip hop?Los análisis académicos recientes acerca de la popularidad mundial del hip hop se ha centrado en su papel en la definición y expresión de determinadas formas de identidad. Sin embargo, coincidiendo con este interés son las preocupaciones de los académicos y formuladores de políticas sobre aspectos particulares de algunos de los hip hop que ha sido descrito como: "materialista, misógino, homofóbico, racista, vulgar y violento" (Chang, 2007: 58). En consecuencia, la opinión del público, con la influencia de los medios de comunicación y los políticos, ha expresado su preocupación y la culpa, incluso dirigidos a hip hop para los problemas sociales como las pandillas, las actitudes negativas hacia las mujeres y los delitos violentos. Así pues, tenemos una forma global popular de la cultura física que puede ser una parte fundamental de la identidad de la juventud contemporánea y estilos de vida, pero que también se ha marcado no sólo como una amenaza, sino una amenaza potencial a la sociedad. Rara vez son los aspectos positivos del hip hop reconocidos, en particular aquellos en los programas de educación de la juventud. Este estudio examinase cómo la cultura hip hop mundial / América se ha manifestado en la cultura de Nueva Zelanda, los jóvenes, incluida la forma en que influye en la apariencia, el comportamiento, la actividad física, el deporte, la moda, el consumo y la educación. La pregunta general de investigación se centra en: cómo los jóvenes de Nueva Zelanda definir, utilizar y dar sentido a la cultura del hip hop?Recent scholarly analysis of hip hop’s global popularity has focused on its role in defining and expressing particular forms of identity. However, coinciding with this interest are concerns from both scholars and policy makers about particular aspects of some hip hop which has been described as being: “materialistic, misogynistic, homophobic, racist, vulgar and violent” (Chang, 2007: 58). Consequently, public views influenced by the media and politicians have raised concerns and even directed blame at hip hop for social problems such as gangs, negative attitudes towards women and violent crime. Thus we have a globally popular form of physical culture that may be a key part of contemporary youth identity and lifestyles; but which has also been labelled as not only a menace, but a potential threat to society. Rarely are the positives of hip hop recognised, particularly those within youth education programs.  This study examines how global/American hip hop culture has manifested itself within New Zealand youth culture, including how it influences appearance, behaviour, physical activity, sport, fashion, consumption and education. The overall research question focuses on how New Zealand youth define, consume and make sense of hip hop culture?

Critique of arXiv submission 2308.15623, "Discovery of Spherules of Likely Extrasolar Composition in the Pacific Ocean Site of the CNEOS 2014-01-08 (IM1) Bolide", by A. Loeb et al

Recently a manuscript by Loeb et al. was uploaded to arXiv (preprint 2308.15623) that asserted that the CNEOS bolide 2014-01-08 was interstellar; that spherules recovered from the seafloor near the airburst were associated with this bolide; that they had Fe isotopic ratios indicating origin as micrometeorites; that they had unusual chemical compositions enriched in Be, La and U, never seen before in micrometeorite spherules; that these compositions were formed in the magma ocean stage of a differentiated extrasolar planet; and that the Be abundance reflected passage through the interstellar medium. Despite not being peer-reviewed, this uploaded manuscript has been reported by media outlets as "published", and its conclusions have been widely distributed as fact. The purpose of this manuscript is to provide potential peer reviewers and the general public with an appreciation of the multiple fatal flaws with the manuscript's arguments. We discuss the published evidence that the 2014-01-08 bolide is not interstellar. We show that there is no statistical spatial correlation of a chemical signature or even number of recovered spherules with the 2014-01-08 bolide. We demonstrate that the Fe isotopic ratios decisively indicate an origin in our Solar System, with > 99.995% probability. We demonstrate that the unusual enrichments in La, U, etc., have in fact been observed in micrometeorites before and attributed to terrestrial contamination; and that the Be abundances are similarly consistent with those of ferromanganese nodules, after reacting with sea water. Far from being exotic particles from an extrasolar planet, the spherules collected and analyzed by Loeb et al. appear to be just like those found around the world, with a Solar System origin and compositions modified by tens of thousands of years residence at the ocean bottom