The Surprising Computational Power of Nondeterministic Stack RNNs

Traditional recurrent neural networks (RNNs) have a fixed, finite number of memory cells. In theory (assuming bounded range and precision), this limits their formal language recognition power to regular languages, and in practice, RNNs have been shown to be unable to learn many context-free languages (CFLs). In order to expand the class of languages RNNs recognize, prior work has augmented RNNs with a nondeterministic stack data structure, putting them on par with pushdown automata and increasing their language recognition power to CFLs. Nondeterminism is needed for recognizing all CFLs (not just deterministic CFLs), but in this paper, we show that nondeterminism and the neural controller interact to produce two more unexpected abilities. First, the nondeterministic stack RNN can recognize not only CFLs, but also many non-context-free languages. Second, it can recognize languages with much larger alphabet sizes than one might expect given the size of its stack alphabet. Finally, to increase the information capacity in the stack and allow it to solve more complicated tasks with large alphabet sizes, we propose a new version of the nondeterministic stack that simulates stacks of vectors rather than discrete symbols. We demonstrate perplexity improvements with this new model on the Penn Treebank language modeling benchmark.Comment: 20 pages, 7 figures. Submitted to ICLR 202

Dance preservation archives: relationships, access, and technology

Organizations that archive dance documentation assert that the use of archival materials can benefit many aspects of the creative process as well as the education of future dancers and choreographers. This thesis explores the relationship between choreographers and archivists and how current technology has affected access. This research looks at four different types of organizations to examine the state of dance preservation. I gathered data through phone interviews and reviewed online archive databases of the New York Public Library for the Performing Arts, the Library of Congress, Jerome Lawrence and Robert E. Lee Theatre Research Institute at Ohio State University, and Jacob’s Pillow Dance. For archivists, keeping up with changing technology will be an ongoing challenge. Archivists will need to start working with choreographers and dance companies earlier in their careers to preserve digital materials before they disappear.M.S., Arts Administration -- Drexel University, 201

Apresentação

Nos últimos anos, detecta-se uma preocupação crescente com as políticas educativas pela integração das TICs na formação docente, tanto pela centralidade das novas tecnologias como estratégia de democratização do conhecimento como pelo papel fundamental que cumpre a formação docente, inicial e em serviço, para o melhoramento da qualidade educativa e das políticas de equidade. Isso se evidencia, entre outros documentos normativos, nas Metas Educativas 2021, que chamam a atenção para a necessidade de integrar as TICs curricularmente e avaliar seu impacto, assim como promover a capacitação dos professores e difundir as práticas inovadoras para novas audiências. Nas propostas recentes, sublinha-se a necessidade de ampliar os saberes dos docentes e de organizar redes de conhecimento e de práticas que apoiem a renovação pedagógica e curricular. De acordo com algumas pesquisas, a formação docente continuada em serviço revelou-se um território mais fértil do que a formação inicial para a incorporação das novas tecnologias, sobretudo naqueles países em que se implementaram políticas de equipamento massivo nas escolas e onde surgiu a necessidade de preparar os docentes em exercício. Esta oferta se organiza fundamentalmente através de plataformas virtuais, embora também se sustente em cursos presenciais e em materiais didáticos digitais que chegam física ou virtualmente às escolas. Entre as vantagens que oferece, incluem-se a expansão da oferta formativa em tempo e espaço, o adaptar-se às necessidades dos usuários, a possibilidade do trabalho de intercâmbio entre colegas e em equipe, o contato com especialistas e com materiais antes inacessíveis, a integração de múltiplas linguagens na produção de conhecimento, a adoção de formas não tradicionais de avaliação, o estreitamento da brecha tecnológica e geracional e sua contribuição para processos de difusão e de transferência do conhecimento ao criar outras redes de saberes..

Presentación

En los últimos años, existe una preocupación creciente de las políticas educativas por la integración de las tic en la formación docente, tanto por la centralidad de las nuevas tecnologías como estrategia de democratización del conocimiento, como por el rol fundamental que cumple la formación docente –inicial y en servicio– para el mejoramiento de la calidad educativa y las políticas de equidad. Ello se evidencia, entre otros documentos normativos, en las Metas Educativas 2021, que han propuesto la necesidad de integrar las tic a los currículos y evaluar su impacto, así como promover la capacitación de los profesores y difundir las prácticas innovadoras a nuevas audiencias. En las propuestas recientes se subraya la necesidad de ampliar los saberes de los docentes y de organizar redes de conocimiento y de prácticas que apoyen la renovación pedagógica y curricular. De acuerdo a algunas investigaciones, la formación docente continua o en servicio ha sido un territorio más fértil que la formación inicial para la incorporación de las nuevas tecnologías, sobre todo en aquellos países en los que se implementaron políticas de equipamiento masivo en las escuelas y surgió la necesidad de preparar a los docentes en ejercicio. Esta oferta se organiza fundamentalmente a través de plataformas virtuales, aunque también se sostiene en cursos presenciales y en materiales didácticos digitales que llegan física o virtualmente a las escuelas. Entre las ventajas que ofrece, se incluyen la expansión de la oferta formativa en tiempo y espacio, el adaptarse a las necesidades de los usuarios, la posibilidad del trabajo de intercambio entre colegas y en equipo, el contacto con especialistas y con materiales antes inaccesibles, la integración de múltiples lenguajes en la producción de conocimiento, la adopción de formas no tradicionales de evaluación, el achicamiento de la brecha tecnológica y generacional, y su aporte a procesos de difusión y transferencia del conocimiento al crear otras redes de saberes..

11 beta-Hydroxysteroid dehydrogenase type 1 contributes to the regulation of 7-oxysterol levels in the arterial wall through the inter-conversion of 7-ketocholesterol and 7 beta-hydroxycholesterol

AbstractThe atherogenic 7-oxysterols, 7-ketocholesterol (7-KC) and 7β-hydroxycholesterol (7βOHC), can directly impair arterial function. Inter-conversion of 7-KC and 7βOHC has recently been shown as a novel role for the glucocorticoid-metabolizing enzyme 11β-hydroxysteroid dehydrogenase type 1 (11β-HSD1). Since this enzyme is expressed in vascular smooth muscle cells, we addressed the hypothesis that inter-conversion of 7-KC and 7βOHC by 11β-HSD1 may contribute to regulation of arterial function.Incubation (4–24 h) of aortic rings with either 7-KC (25 μM) or 7βOHC (20 μM) had no effect on endothelium-dependent (acetylcholine) or -independent (sodium nitroprusside) relaxation. In contrast, exposure to 7-KC (but not to 7βOHC) attenuated noradrenaline-induced contraction (Emax) after 4 h (0.78 ± 0.28 vs 0.40 ± 0.08 mN/mm; p < 0.05) and 24 h (2.28 ± 0.34 vs 1.56 ± 0.48 mN/mm; p < 0.05). Both 7-oxysterols were detected by GCMS in the aortic wall of chow-fed C57Bl6/J mice, with concentrations of 7-KC (1.41 ± 0.81 ng/mg) higher (p = 0.05) than 7βOHC (0.16 ± 0.06 ng/mg). In isolated mouse aortic rings 11β-HSD1 was shown to act as an oxo-reductase, inter-converting 7-KC and 7βOHC. This activity was lost in aorta from 11β-HSD1−/− mice, which had low oxysterol levels. Renal homogenates from 11β-HSD1−/− mice were used to confirm that the type 2 isozyme of 11β-HSD does not inter-convert 7-KC and 7βOHC.These results demonstrate that 7-KC has greater effects than 7βOHC on vascular function, and that 11β-HSD1 can inter-convert 7-KC and 7βOHC in the arterial wall, contributing to the regulation of 7-oxysterol levels and potentially influencing vascular function. This mechanism may be important in the cardioprotective effects of 11β-HSD1 inhibitors

HMG-CoAR expression in male breast cancer: relationship with hormone receptors, Hippo transducers and survival outcomes

Male breast cancer (MBC) is a rare hormone-driven disease often associated with obesity. HMG-CoAR is the central enzyme of the mevalonate pathway, a molecular route deputed to produce cholesterol and steroid-based hormones. HMG-CoAR regulates the oncogenic Hippo transducers TAZ/YAP whose expression was previously associated with shorter survival in MBC. 225 MBC samples were immunostained for HMG-CoAR and 124 were considered eligible for exploring its relationship with hormone receptors (ER, PgR, AR), Hippo transducers and survival outcomes. HMG-CoAR was positively associated with the expression of hormone receptors (ER, PgR, AR) and Hippo transducers. Overall survival was longer in patients with HMG-CoAR-positive tumors compared with their negative counterparts (p = 0.031). Five- and 10-year survival outcomes were better in patients whose tumors expressed HMG-CoAR (p = 0.044 and p = 0.043). Uni- and multivariate analyses for 10-year survival suggested that HMG-CoAR expression is a protective factor (HR 0.50, 95% CI: 0.25–0.99, p = 0.048 and HR 0.53, 95% CI: 0.26–1.07, p = 0.078). Results were confirmed in a sensitivity analysis by excluding uncommon histotypes (multivariate Cox: HR 0.45, 95% CI: 0.21–0.97, p = 0.043). A positive relationship emerged between HMG-CoAR, hormone receptors and TAZ/YAP, suggesting a connection between the mevalonate pathway, the hormonal milieu and Hippo in MBC. Moreover, HMG-CoAR expression may be a favorable prognostic indicator

The Cholesterol Metabolite 25-Hydroxycholesterol Activates Estrogen Receptor α-Mediated Signaling in Cancer Cells and in Cardiomyocytes

The hydroxylated derivatives of cholesterol, such as the oxysterols, play important roles in lipid metabolism. In particular, 25-hydroxycholesterol (25 HC) has been implicated in a variety of metabolic events including cholesterol homeostasis and atherosclerosis. 25 HC is detectable in human plasma after ingestion of a meal rich in oxysterols and following a dietary cholesterol challenge. In addition, the levels of oxysterols, including 25 HC, have been found to be elevated in hypercholesterolemic serum.Here, we demonstrate that the estrogen receptor (ER) α mediates gene expression changes and growth responses induced by 25 HC in breast and ovarian cancer cells. Moreover, 25 HC exhibits the ERα-dependent ability like 17 β-estradiol (E2) to inhibit the up-regulation of HIF-1α and connective tissue growth factor by hypoxic conditions in cardiomyocytes and rat heart preparations and to prevent the hypoxia-induced apoptosis.The estrogen action exerted by 25 HC may be considered as an additional factor involved in the progression of breast and ovarian tumors. Moreover, the estrogen-like activity of 25 HC elicited in the cardiovascular system may play a role against hypoxic environments

Obesity and male breast cancer: Provocative parallels?

While rare compared to female breast cancer the incidence of male breast cancer (MBC) has increased in the last few decades. Without comprehensive epidemiological studies, the explanation for the increased incidence of MBC can only be speculated. Nevertheless, one of the most worrying global public health issues is the exponential rise in the number of overweight and obese people, especially in the developed world. Although obesity is not considered an established risk factor for MBC, studies have shown increased incidence among obese individuals. With this observation in mind, this article highlights the correlation between the increased incidence of MBC and the current trends in obesity as a growing problem in the 21st century, including how this may impact treatment. With MBC becoming more prominent we put forward the notion that, not only is obesity a risk factor for MBC, but that increasing obesity trends are a contributing factor to its increased incidence