Instantaneous frequencies in the Kuramoto model

Using the main results of the Kuramoto theory of globally coupled phase oscillators combined with methods from probability and generalized function theory in a geometric analysis, we extend Kuramoto's results and obtain a mathematical description of the instantaneous frequency (phase-velocity) distribution. Our result is validated against numerical simulations, and we illustrate it in cases where the natural frequencies have normal and Beta distributions. In both cases, we vary the coupling strength and compare systematically the distribution of time-averaged frequencies (a known result of Kuramoto theory) to that of instantaneous frequencies, focussing on their qualitative differences near the synchronized frequency and in their tails. For a class of natural frequency distributions with power-law tails, which includes the Cauchy-Lorentz distribution, we analyze rare events by means of an asymptotic formula obtained from a power series expansion of the instantaneous frequency distribution

Density of instantaneous frequencies in the Kuramoto-Sakaguchi model

We obtain a formula for the statistical distribution of instantaneous frequencies in the Kuramoto-Sakaguchi model. This work is based on the Kuramoto-Sakaguchi's theory of globally coupled phase oscillators, which we review in full detail by discussing its assumptions and showing all steps behind the derivation of its main results. Our formula is a stationary probability density function with a complex mathematical structure, is consistent with numerical simulations and gives a description of the stationary collective states of the Kuramoto-Sakaguchi model

Un examen actualizado de la percepción de las barreras para la implementación de la farmacogenómica y la utilidad de los pares fármaco/gen en América Latina y el Caribe

La farmacogenómica (PGx) se considera un campo emergente en los países en desarrollo. La investigación sobre PGx en la región de América Latina y el Caribe (ALC) sigue siendo escasa, con información limitada en algunas poblaciones. Por lo tanto, las extrapolaciones son complicadas, especialmente en poblaciones mixtas. En este trabajo, revisamos y analizamos el conocimiento farmacogenómico entre la comunidad científica y clínica de ALC y examinamos las barreras para la aplicación clínica. Realizamos una búsqueda de publicaciones y ensayos clínicos en este campo en todo el mundo y evaluamos la contribución de ALC. A continuación, realizamos una encuesta regional estructurada que evaluó una lista de 14 barreras potenciales para la aplicación clínica de biomarcadores en función de su importancia. Además, se analizó una lista emparejada de 54 genes/fármacos para determinar una asociación entre los biomarcadores y la respuesta a la medicina genómica. Esta encuesta se comparó con una encuesta anterior realizada en 2014 para evaluar el progreso en la región. Los resultados de la búsqueda indicaron que los países de América Latina y el Caribe han contribuido con el 3,44% del total de publicaciones y el 2,45% de los ensayos clínicos relacionados con PGx en todo el mundo hasta el momento. Un total de 106 profesionales de 17 países respondieron a la encuesta. Se identificaron seis grandes grupos de obstáculos. A pesar de los continuos esfuerzos de la región en la última década, la principal barrera para la implementación de PGx en ALC sigue siendo la misma, la "necesidad de directrices, procesos y protocolos para la aplicación clínica de la farmacogenética/farmacogenómica". Las cuestiones de coste-eficacia se consideran factores críticos en la región. Los puntos relacionados con la reticencia de los clínicos son actualmente menos relevantes. Según los resultados de la encuesta, los pares gen/fármaco mejor clasificados (96%-99%) y percibidos como importantes fueron CYP2D6/tamoxifeno, CYP3A5/tacrolimus, CYP2D6/opioides, DPYD/fluoropirimidinas, TMPT/tiopurinas, CYP2D6/antidepresivos tricíclicos, CYP2C19/antidepresivos tricíclicos, NUDT15/tiopurinas, CYP2B6/efavirenz y CYP2C19/clopidogrel. En conclusión, aunque la contribución global de los países de ALC sigue siendo baja en el campo del PGx, se ha observado una mejora relevante en la región. La percepción de la utilidad de las pruebas PGx en la comunidad biomédica ha cambiado drásticamente, aumentando la concienciación entre los médicos, lo que sugiere un futuro prometedor en las aplicaciones clínicas de PGx en ALC.Pharmacogenomics (PGx) is considered an emergent field in developing countries. Research on PGx in the Latin American and the Caribbean (LAC) region remains scarce, with limited information in some populations. Thus, extrapolations are complicated, especially in mixed populations. In this paper, we reviewed and analyzed pharmacogenomic knowledge among the LAC scientific and clinical community and examined barriers to clinical application. We performed a search for publications and clinical trials in the field worldwide and evaluated the contribution of LAC. Next, we conducted a regional structured survey that evaluated a list of 14 potential barriers to the clinical implementation of biomarkers based on their importance. In addition, a paired list of 54 genes/drugs was analyzed to determine an association between biomarkers and response to genomic medicine. This survey was compared to a previous survey performed in 2014 to assess progress in the region. The search results indicated that Latin American and Caribbean countries have contributed 3.44% of the total publications and 2.45% of the PGx-related clinical trials worldwide thus far. A total of 106 professionals from 17 countries answered the survey. Six major groups of barriers were identified. Despite the region’s continuous efforts in the last decade, the primary barrier to PGx implementation in LAC remains the same, the “need for guidelines, processes, and protocols for the clinical application of pharmacogenetics/pharmacogenomics”. Cost-effectiveness issues are considered critical factors in the region. Items related to the reluctance of clinicians are currently less relevant. Based on the survey results, the highest ranked (96%–99%) gene/drug pairs perceived as important were CYP2D6/tamoxifen, CYP3A5/tacrolimus, CYP2D6/opioids, DPYD/fluoropyrimidines, TMPT/thiopurines, CYP2D6/tricyclic antidepressants, CYP2C19/tricyclic antidepressants, NUDT15/thiopurines, CYP2B6/efavirenz, and CYP2C19/clopidogrel. In conclusion, although the global contribution of LAC countries remains low in the PGx field, a relevant improvement has been observed in the region. The perception of the usefulness of PGx tests in biomedical community has drastically changed, raising awareness among physicians, which suggests a promising future in the clinical applications of PGx in LAC

Artesãos, cartografia e império. A produção social de um instrumento náutico no mundo ibérico, 1500-1650

Explicar cómo y en qué condiciones fueron construidos algunos de los instrumentos científicos más emblemáticos del mundo moderno sigue siendo un desafío para los historiadores de la ciencia y de la tecnología. Este principio afecta también a los instrumentos náuticos. Así, el objetivo del presente artículo es considerar el “cómo” y el “en qué condiciones”, en un sentido amplio, analizando uno de estos artefactos: las cartas náuticas construidas durante la expansión marítima europea. Originalidad: La originalidad del texto no reside únicamente en llevar a cabo una reconstrucción de este instrumento en Portugal y España que aporte nuevos datos sobre su proceso de fabricación y sus fabricantes, sino también en arrojar luz sobre antiguos debates historiográficos que subyacen a la génesis de la ciencia moderna, tales como la difícil colaboración entre hombres prácticos y hombres teóricos; la aportación de comunidades de artesanos al mundo del conocimiento; el papel que los saberes prácticos tuvieron en el establecimiento de nuevas formas de estandarización en ciencia; la adopción de una metodología empírica para el dominio del mundo o la construcción de grandes imperios globales cimentados sobre la base del trabajo manual. Metodología: El análisis de estos debates requiere una aproximación metodológica que atienda a las categorías y los conceptos principales puestos en circulación tanto por la historia como por la filosofía de la ciencia más reciente. En definitiva, se trata de atender a las condiciones que permitieron el establecimiento de acuerdos (y también de controversias) epistemológicos entre diferentes comunidades de conocimiento tomando un instrumento náutico como “mediador”. Conclusiones: El artículo concluye que la consideración de las culturas empíricas del conocimiento y sus realizaciones materiales son una condición sine qua non para entender la génesis de la modernidad científica europea y la construcción de un mundo globalExplaining how and under what conditions some of the most emblematic scientific instruments of the modern world were built remains a challenge for historians of science and technology. This principle also affects nautical instruments. Thus, the objective of this article is to consider the “how” and the “under what conditions”, in a broad sense, by examining one of these devices: the nautical charts developed during the European maritime expansion. Originality: The originality of this article lies not only in the reconstruction of this instrument in Portugal and Spain, providing new information about its development process and its manufacturers, but also in shedding light on old historiographical debates that underlie the genesis of modern science, such as the difficult collaboration between practical men and theoretical men; the contribution of artisan communities to the world of knowledge; the role that practical knowledge played in the establishment of new forms of standardization in science; the adoption of an empirical methodology for achieving mastery of the world or the construction of large global empires founded upon manual labor. Methodology: Analyzing these debates requires a methodological approach that addresses the main categories and concepts put into circulation by the most recent history and philosophy of science. In short, unveiling the conditions that enabled the establishment of epistemological agreements (and also disputes) between different knowledge communities by taking a nautical instrument as “mediator.” Conclusions: The article concludes that examining empirical knowledge cultures and their material achievements are a sine qua non condition to understand the genesis of European scientific modernity and the construction of a global worldExplicar como e em que condições foram construídos alguns dos instrumentos científicos mais emblemáticos do mundo moderno continua sendo um desafio para os historiadores da ciência e da tecnologia. Esse princípio afeta também os instrumentos náuticos. Assim, o objetivo do presente artigo é considerar o “como” e o “em que condições”, em um sentido amplo, e analisar um desses artefatos: as cartas náuticas construídas durante a expansão marítima europeia. Originalidade: A originalidade do texto não reside unicamente na realização de uma reconstrução desse instrumento em Portugal e na Espanha de forma que traga novos dados sobre seu processo de fabricação e de seus fabricantes, mas também em lançar luz sobre antigos debates historiográficos que subjazem à gênese da ciência moderna, tais como a difícil colaboração entre homens práticos e homens teóricos, a contribuição de comunidades de artesãos ao mundo do conhecimento; o papel que os saberes práticos tiveram no estabelecimento de novas formas de padronização na ciência, a adoção de uma metodologia empírica para o domínio do mundo ou a construção de grandes impérios globais cimentados sobre a base do trabalho manual. Metodologia: A análise desses debates requer uma aproximação metodológica que atenda às categorias e aos principais conceitos colocados em circulação tanto pela história quanto pela filosofia da ciência mais recente. Definitivamente, trata-se de atender às condições que permitiram o estabelecimento de acordos (e também de controvérsias) epistemológicos entre diferentes comunidades de conhecimento tomando o instrumento náutico como “mediador”. Conclusões: O artigo conclui que a consideração das culturas empíricas do conhecimento e suas realizações materiais são uma condição sine qua non para entender a gênese da modernidade científica europeia e a construção de um mundo globa

Pervasive gaps in Amazonian ecological research

Biodiversity loss is one of the main challenges of our time,1,2 and attempts to address it require a clear un derstanding of how ecological communities respond to environmental change across time and space.3,4 While the increasing availability of global databases on ecological communities has advanced our knowledge of biodiversity sensitivity to environmental changes,5–7 vast areas of the tropics remain understudied.8–11 In the American tropics, Amazonia stands out as the world’s most diverse rainforest and the primary source of Neotropical biodiversity,12 but it remains among the least known forests in America and is often underrepre sented in biodiversity databases.13–15 To worsen this situation, human-induced modifications16,17 may elim inate pieces of the Amazon’s biodiversity puzzle before we can use them to understand how ecological com munities are responding. To increase generalization and applicability of biodiversity knowledge,18,19 it is thus crucial to reduce biases in ecological research, particularly in regions projected to face the most pronounced environmental changes. We integrate ecological community metadata of 7,694 sampling sites for multiple or ganism groups in a machine learning model framework to map the research probability across the Brazilian Amazonia, while identifying the region’s vulnerability to environmental change. 15%–18% of the most ne glected areas in ecological research are expected to experience severe climate or land use changes by 2050. This means that unless we take immediate action, we will not be able to establish their current status, much less monitor how it is changing and what is being lostinfo:eu-repo/semantics/publishedVersio

Factors influencing terrestriality in primates of the Americas and Madagascar

Among mammals, the order Primates is exceptional in having a high taxonomic richness in which the taxa are arboreal, semiterrestrial, or terrestrial. Although habitual terrestriality is pervasive among the apes and African and Asian monkeys (catarrhines), it is largely absent among monkeys of the Americas (platyrrhines), as well as galagos, lemurs, and lorises (strepsirrhines), which are mostly arboreal. Numerous ecological drivers and species-specific factors are suggested to set the conditions for an evolutionary shift from arboreality to terrestriality, and current environmental conditions may provide analogous scenarios to those transitional periods. Therefore, we investigated predominantly arboreal, diurnal primate genera from the Americas and Madagascar that lack fully terrestrial taxa, to determine whether ecological drivers (habitat canopy cover, predation risk, maximum temperature, precipitation, primate species richness, human population density, and distance to roads) or species-specific traits (bodymass, group size, and degree of frugivory) associate with increased terrestriality. We collated 150,961 observation hours across 2,227 months from 47 species at 20 sites in Madagascar and 48 sites in the Americas. Multiple factors were associated with ground use in these otherwise arboreal species, including increased temperature, a decrease in canopy cover, a dietary shift away from frugivory, and larger group size. These factors mostly explain intraspecific differences in terrestriality. As humanity modifies habitats and causes climate change, our results suggest that species already inhabiting hot, sparsely canopied sites, and exhibiting more generalized diets, are more likely to shift toward greater ground use

Outcomes from elective colorectal cancer surgery during the SARS-CoV-2 pandemic

This study aimed to describe the change in surgical practice and the impact of SARS-CoV-2 on mortality after surgical resection of colorectal cancer during the initial phases of the SARS-CoV-2 pandemic

A social and ecological assessment of tropical land uses at multiple scales: the Sustainable Amazon Network

Science has a critical role to play in guiding more sustainable development trajectories. Here, we present the Sustainable Amazon Network (Rede Amazonia Sustentavel, RAS): a multidisciplinary research initiative involving more than 30 partner organizations working to assess both social and ecological dimensions of land-use sustainability in eastern Brazilian Amazonia. The research approach adopted by RAS offers three advantages for addressing land-use sustainability problems: (i) the collection of synchronized and co-located ecological and socioeconomic data across broad gradients of past and present human use; (ii) a nested sampling design to aid comparison of ecological and socioeconomic conditions associated with different land uses across local, landscape and regional scales; and (iii) a strong engagement with a wide variety of actors and non-research institutions. Here, we elaborate on these key features, and identify the ways in which RAS can help in highlighting those problems in most urgent need of attention, and in guiding improvements in land-use sustainability in Amazonia and elsewhere in the tropics. We also discuss some of the practical lessons, limitations and realities faced during the development of the RAS initiative so far.Keywords: Social–ecological systems, Tropical forests, Land use, Interdisciplinary research, Sustainability, Trade-off