172 research outputs found

    The value of paleoecology as an aid to monitoring ecosystems and landscapes, chiefly with reference to North America

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    Paleoecological indicators are examined as to their accuracy in reconstructing past biotic communities and environmental conditions, their utility in answering important questions about such communities and conditions, and the temporal and spatial scales over which they are effective. Next, environmental problems susceptible of paleoecological analysis are considered, as are the ecosystem and landscape properties that can be inferred from such an analysis. The usefulness of paleoecology in anticipating ecological surprises is then discussed. Finally, a set of conclusions and recommendations is presented

    Origin of immature loggerhead sea turtles (Caretta caretta) at Hutchinson Island, Florida: evidence from mtDNA markers

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    Loggerhead sea turtles (Caretta caretta) are migratory, long-lived, and slow maturing. They are difficult to study because they are seen rarely and their habitats range over vast stretches of the ocean. Movements of immature turtles between pelagic and coastal developmental habitats are particularly difficult to investigate because of inadequate tagging technologies and the difficulty in capturing significant numbers of turtles at sea. However, genetic markers found in mitochondrial DNA (mtDNA) provide a basis for predicting the origin of juvenile turtles in developmental habitats. Mixed stock analysis was used to determine which nesting populations were contributing individuals to a foraging aggregation of immature loggerhead turtles (mean 63.3 cm straight carapace length [SCL]) captured in coastal waters off Hutchinson Island, Florida. The results indicated that at least three different western Atlantic loggerhead sea turtle subpopulations contribute to this group: south Florida (69%), Mexico (20%), and northeast Florida-North Carolina (10%). The conservation and management of these immature sea turtles is complicated by their multinational genetic demographics

    Visualization of microbe-dietary remnant interactions in digesta from pigs, by fluorescence in situ hybridization and staining methods; effects of a dietary arabinoxylan-rich wheat fraction

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    This study investigated how the addition of a specific hydrocolloid, arabinoxylan (AX), to the pig diets containing red meat, affected the gut microbiota in terms of changes to the bacterial community dynamics. Fluorescence in situ hybridization (FISH) was used to enumerate both broad groups and particular bacterial species, and showed systematic differences in pigs fed AX. In addition, the role of bacteria in the fermentation of dietary substrates was studied by visualizing direct associations between the bacteria and substrate particles. To achieve this, novel methods of combining histological staining or enzymatic labelling with FISH protocols were established. In this way, undigested and/or unfermented remnants of meat, endogenous mucin, and several plant cell wall hydrocolloids (cellulose, lignin and arabinoxylan) were distinguished, together with large intestine microbiota under brightfield and/or confocal laser scanning microscopy (CLSM). It was evident that no apparent direct associations occurred between specific classes or groups of bacteria and meat, mucin, lignin or AX remnants. In contrast, bacteria belonging to Clostridium clusters XIVa and XIVb formed a strong (P < 0.01) direct association with cellulose remnants in the pig digesta in the caecum

    The Promise of Prediction Markets

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    Prediction markets are markets for contracts that yield payments based on the outcome of an uncertain future event, such as a presidential election. Using these markets as forecasting tools could substantially improve decision making in the private and public sectors. We argue that U.S. regulators should lower barriers to the creation and design of prediction markets by creating a safe harbor for certain types of small stakes markets. We believe our proposed change has the potential to stimulate innovation in the design and use of prediction markets throughout the economy, and in the process to provide information that will benefit the private sector and government alike.Technology and Industry

    The Impact of Digital Storytelling on Social Agency: Early Experience at an Online University

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    Digital Storytelling\u27 is a term often used to refer to a number of different types of digital narrative including web-based stories, hypertexts, videoblogs and computer games. This emergent form of creative work has found an outlet in a wide variety of different domains ranging from community social history, to cookbooks, to the classroom. It is the latter domain that provides the focus for this paper, specifically the online classroom at the tertiary level...Early feedback from students suggests that listening to and telling \u27true stories\u27 was a compelling and emotionally-engaging experience, providing an opportunity for \u27transformative reflection\u27 (Lambert 2000). By including multimedia, learners were able to build upon the fundamentals, presenting content in an easy-to-absorb and compelling way. In terms of team assignments students learned to become more effective actors in collaborative work environments

    A Global Mitigation Hierarchy for Nature Conservation

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    Efforts to conserve biodiversity comprise a patchwork of international goals, national-level plans, and local interventions that, overall, are failing. We discuss the potential utility of applying the mitigation hierarchy, widely used during economic development activities, to all negative human impacts on biodiversity. Evaluating all biodiversity losses and gains through the mitigation hierarchy could help prioritize consideration of conservation goals and drive the empirical evaluation of conservation investments through the explicit consideration of counterfactual trends and ecosystem dynamics across scales. We explore the challenges in using this framework to achieve global conservation goals, including operationalization and monitoring and compliance, and we discuss solutions and research priorities. The mitigation hierarchy's conceptual power and ability to clarify thinking could provide the step change needed to integrate the multiple elements of conservation goals and interventions in order to achieve successful biodiversity outcomes

    Damaging variants in FOXI3 cause microtia and craniofacial microsomia

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    Q1Q1Pacientes con Microtia y Microsomía craneofacialPurpose: Craniofacial microsomia (CFM) represents a spectrum of craniofacial malformations, ranging from isolated microtia with or without aural atresia to underdevelopment of the mandible, maxilla, orbit, facial soft tissue, and/or facial nerve. The genetic causes of CFM remain largely unknown. Methods: We performed genome sequencing and linkage analysis in patients and families with microtia and CFM of unknown genetic etiology. The functional consequences of damaging missense variants were evaluated through expression of wild-type and mutant proteins in vitro. Results: We studied a 5-generation kindred with microtia, identifying a missense variant in FOXI3 (p.Arg236Trp) as the cause of disease (logarithm of the odds = 3.33). We subsequently identified 6 individuals from 3 additional kindreds with microtia-CFM spectrum phenotypes harboring damaging variants in FOXI3, a regulator of ectodermal and neural crest development. Missense variants in the nuclear localization sequence were identified in cases with isolated microtia with aural atresia and found to affect subcellular localization of FOXI3. Loss of function variants were found in patients with microtia and mandibular hypoplasia (CFM), suggesting dosage sensitivity of FOXI3. Conclusion: Damaging variants in FOXI3 are the second most frequent genetic cause of CFM, causing 1% of all cases, including 13% of familial cases in our cohort.https://orcid.org/0000-0003-3822-7780https://orcid.org/0000-0002-0729-6866Revista Internacional - IndexadaA1N
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