135 research outputs found
Comentario sobre la guerra del Paraguay en la provincia de Corrientes. Impactos políticos, daños, y consecuencias en la población civil de Dardo Ramírez Braschi
En los últimos años el avance de la historiografía correntina ha sido de magnitud. El aporte del conocimiento del pasado provincial fue innovador sobre todo en lo referente a períodos socio-políticos de los cuales nada sabíamos hasta hace muy poco.Esta evolución favorable desde todo punto de vista se produjo por la presencia de varios factores entre el que sobresale la importancia adquirida por Institutos estatales de relieve como ser el Instituto de Investigaciones Geohistóricas con sede en Resistencia, que aportó en abundancia trabajos científicos que enriquecieron de sobremanera la interpretación del pasado motivando a propios y extraños la profúndización de ese conocimiento
La cuestión de perspectiva en los orígenes de la Guerra del Paraguay. Una conversación entre Thomas Whigham, Juan Manuel Casal y Dardo Ramírez Braschi.
La Guerra de la Triple Alianza (1864-1870) se considera generalmente como un evento catalítico en la América del Sur del siglo XIX. Sus orígenes, sin embargo, todavía están muy disputados. En este conversatorio, tres historiadores de alta jerarquía (un argentino, un uruguayo y un norteamericano) discuten las causas del conflicto y, en particular, cómo la historiografía de la guerra ha sido afectada por varias interpretaciones nacionales. Los tres piden más esfuerzo y más estudios ajustados referentes a los orígenes de la guerra y, en particular, advierten contra las interpretaciones que carecen de evidencia documental. Las especulaciones provenientes de todas las direcciones son bienvenidas; sólo una lectura más cercana de los materiales documentales producirá el tipo superior de investigación que requiere el tema. Además, el progreso real depende de académicos de diferentes naciones y otras escuelas históricas que discuten la mejor manera de desarrollar esta área
Impacts of Coastal Land Use and Shoreline Armoring on Estuarine Ecosystems: an Introduction to a Special Issue
The nearshore land-water interface is an important ecological zone that faces anthropogenic pressure from development in coastal regions throughout the world. Coastal waters and estuaries like Chesapeake Bay receive and process land discharges loaded with anthropogenic nutrients and other pollutants that cause eutrophication, hypoxia, and other damage to shallow-water ecosystems. In addition, shorelines are increasingly armored with bulkhead (seawall), riprap, and other structures to protect human infrastructure against the threats of sea-level rise, storm surge, and erosion. Armoring can further influence estuarine and nearshore marine ecosystem functions by degrading water quality, spreading invasive species, and destroying ecologically valuable habitat. These detrimental effects on ecosystem function have ramifications for ecologically and economically important flora and fauna. This special issue of Estuaries and Coasts explores the interacting effects of coastal land use and shoreline armoring on estuarine and coastal marine ecosystems. The majority of papers focus on the Chesapeake Bay region, USA, where 50 major tributaries and an extensive watershed (similar to 167,000 km(2)), provide an ideal model to examine the impacts of human activities at scales ranging from the local shoreline to the entire watershed. The papers consider the influence of watershed land use and natural versus armored shorelines on ecosystem properties and processes as well as on key natural resources
The Commit to Be Fit framework: a community case study of a multi-level, holistic school-based wellness initiative in rural Virginia
BackgroundPublic health interventions that target children's physical, mental, and emotional health will enhance their ability to learn and grow. Although more complex, school initiatives that address multiple ecological levels and take a holistic view may be more effective and likely to lead to lasting change.AimsThis article presents the framework of Commit to Be Fit (C2BF) as an example of how schools can integrate multi-level and holistic approaches for health. This innovative school-based intervention includes activities addressing individual, home, school, and community to create a culture of wellness. We describe the implementation of C2BF and its basis in ecological models and give examples of activities across three components: cafeteria, classroom, and community. We discuss challenges and note that leadership engagement and alignment were critical elements for C2BF's success thus far.DiscussionC2BF uses a school-based multi-level approach to creating a culture of wellness and holistic health for students, teachers, and community members. C2BF is unique compared to other school-based programming and includes activities that address all eight domains posited for program sustainability within public health. Built to be flexible and adaptive, C2BF was able to successfully pivot during the COVID pandemic and also follow new science.ConclusionC2BF and other multi-level holistic approaches are more likely to achieve long-term change by utilizing strategies across the multiple levels of the ecological model to improve health and wellbeing
Cosmopolitan Species As Models for Ecophysiological Responses to Global Change: The Common Reed \u3cem\u3ePhragmites australis\u3c/em\u3e
Phragmites australis is a cosmopolitan grass and often the dominant species in the ecosystems it inhabits. Due to high intraspecific diversity and phenotypic plasticity, P. australis has an extensive ecological amplitude and a great capacity to acclimate to adverse environmental conditions; it can therefore offer valuable insights into plant responses to global change. Here we review the ecology and ecophysiology of prominent P. australis lineages and their responses to multiple forms of global change. Key findings of our review are that: (1) P. australis lineages are well-adapted to regions of their phylogeographic origin and therefore respond differently to changes in climatic conditions such as temperature or atmospheric CO2; (2) each lineage consists of populations that may occur in geographically different habitats and contain multiple genotypes; (3) the phenotypic plasticity of functional and fitness-related traits of a genotype determine the responses to global change factors; (4) genotypes with high plasticity to environmental drivers may acclimate or even vastly expand their ranges, genotypes of medium plasticity must acclimate or experience range-shifts, and those with low plasticity may face local extinction; (5) responses to ancillary types of global change, like shifting levels of soil salinity, flooding, and drought, are not consistent within lineages and depend on adaptation of individual genotypes. These patterns suggest that the diverse lineages of P. australis will undergo intense selective pressure in the face of global change such that the distributions and interactions of co-occurring lineages, as well as those of genotypes within-lineages, are very likely to be altered. We propose that the strong latitudinal clines within and between P. australis lineages can be a useful tool for predicting plant responses to climate change in general and present a conceptual framework for using P. australis lineages to predict plant responses to global change and its consequences
Cosmopolitan Species as Models for Ecophysiological Responses to Global Change: The Common Reed Phragmites australis
Phragmites australis is a cosmopolitan grass and often the dominant species in the ecosystems it inhabits. Due to high intraspecific diversity and phenotypic plasticity, P. australis has an extensive ecological amplitude and a great capacity to acclimate to adverse environmental conditions; it can therefore offer valuable insights into plant responses to global change. Here we review the ecology and ecophysiology of prominent P. australis lineages and their responses to multiple forms of global change. Key findings of our review are that: (1) P. australis lineages are well-adapted to regions of their phylogeographic origin and therefore respond differently to changes in climatic conditions such as temperature or atmospheric CO2; (2) each lineage consists of populations that may occur in geographically different habitats and contain multiple genotypes; (3) the phenotypic plasticity of functional and fitness-related traits of a genotype determine the responses to global change factors; (4) genotypes with high plasticity to environmental drivers may acclimate or even vastly expand their ranges, genotypes of medium plasticity must acclimate or experience range-shifts, and those with low plasticity may face local extinction; (5) responses to ancillary types of global change, like shifting levels of soil salinity, flooding, and drought, are not consistent within lineages and depend on adaptation of individual genotypes. These patterns suggest that the diverse lineages of P. australis will undergo intense selective pressure in the face of global change such that the distributions and interactions of co-occurring lineages, as well as those of genotypes within-lineages, are very likely to be altered. We propose that the strong latitudinal clines within and between P. australis lineages can be a useful tool for predicting plant responses to climate change in general and present a conceptual framework for using P. australis lineages to predict plant responses to global change and its consequences
One thousand plant transcriptomes and the phylogenomics of green plants
Abstract: Green plants (Viridiplantae) include around 450,000–500,000 species1, 2 of great diversity and have important roles in terrestrial and aquatic ecosystems. Here, as part of the One Thousand Plant Transcriptomes Initiative, we sequenced the vegetative transcriptomes of 1,124 species that span the diversity of plants in a broad sense (Archaeplastida), including green plants (Viridiplantae), glaucophytes (Glaucophyta) and red algae (Rhodophyta). Our analysis provides a robust phylogenomic framework for examining the evolution of green plants. Most inferred species relationships are well supported across multiple species tree and supermatrix analyses, but discordance among plastid and nuclear gene trees at a few important nodes highlights the complexity of plant genome evolution, including polyploidy, periods of rapid speciation, and extinction. Incomplete sorting of ancestral variation, polyploidization and massive expansions of gene families punctuate the evolutionary history of green plants. Notably, we find that large expansions of gene families preceded the origins of green plants, land plants and vascular plants, whereas whole-genome duplications are inferred to have occurred repeatedly throughout the evolution of flowering plants and ferns. The increasing availability of high-quality plant genome sequences and advances in functional genomics are enabling research on genome evolution across the green tree of life
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