121 research outputs found

    Release and Establishment of Megamelus scutellaris (Hemiptera: Delphacidae) on Waterhyacinth in Florida

    Get PDF
    More than 73,000 Megamelus scutellaris (Hemiptera: Delphacidae) were released in Florida over a 2 to 3 yr period at 10 sites in an attempt to establish sustainable populations on waterhyacinth, Eichhornia crassipes Mart. Solms (Commelinales: Pontederiaceae). Insect populations persisted at most sites including those furthest north and consecutive overwintering was confirmed in as many as three times at some sites. Establishment appeared to be promoted at sites with some cover or shading compared to open areas. Insects readily dispersed over short distances which made detection and monitoring difficultFil: Tipping, Philip W.. Invasive Plant Research Laboratory; Estados UnidosFil: Sosa, Alejandro Joaquín. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Fundación para el Estudio de Especies Invasivas; ArgentinaFil: Pokorny, Eileen N.. Invasive Plant Research Laboratory; Estados UnidosFil: Foley, Jeremiah. Invasive Plant Research Laboratory; Estados UnidosFil: Schmitz, Don C.. Florida Fish and Wildlife Conservation Commission; Estados UnidosFil: Lane, Jon S.. U.S. Army Corps of Engineers; Estados UnidosFil: Rodgers, Leroy. South Florida Water Management District; Estados UnidosFil: Mccloud, Lori. St. Johns River Water Management District; Estados UnidosFil: Livingston-Way, Pam. St. Johns River Water Management District; Estados UnidosFil: Cole, Matthew S.. St. Johns River Water Management District; Estados UnidosFil: Nichols, Gary. St. Johns River Water Management District; Estados Unido

    Fine Root Dynamics in Atlantic White Cedar (\u3ci\u3eChamaecyparis thyoides\u3c/i\u3e) Wetlands: Patterns of Ecosystem Development in Natural and Restoration Settings

    Get PDF
    This work addresses seasonal and successional factors of root dynamics in natural and restoration Atlantic white cedar (AWC) wetlands. Using minirhizotrons, fine root dynamics in a chronosequence of naturally-regenerating and restoration AWC wetlands were measured to compare ecosystem development trends with restoration conditions. A second study was conducted to compare fine root dynamics in AWC wetlands with contrasting hydroperiods. In addition, a technical study was conducted to determine the feasibility of estimating root biomass with indirect minirhizotron measurements. Root biomass estimates using minirhizotrons were significantly higher in naturally regenerating AWC wetlands and significantly lower in the restoration site relative to soil core estimates. Differences in root viability determinations between the two methods and overestimation of fine roots were identified as factors contributing to observed differences between the two methods. The chronosequence study revealed significant seasonal variation of root dynamics in the young naturally regenerating and restoration sites. The mature and intermediate-aged sites did not exhibit seasonal variability in root abundance or mortality. Root production was variable but not seasonally consistent. Results suggest that root dynamics become less seasonal as AWC communities shift from herbaceous to woody vegetation dominance. There was no apparent trend in fine root abundance along the chronosequence, suggesting that roots rapidly recover from tree harvest disturbances. Annual root length production measurements suggest increasing annual production with decreasing stand age. However, the combining of length: mass root relationships with minirhizotron measurements resulted in a reversal of this trend. These findings underscore the importance of supplementing minirhizotron data with root allometric relationships if comparing across vegetation gradients. Overall, results suggest that root contributions to soil organic matter may be substantially less in the restoration site relative to naturally regenerating sites. Root dynamics and rooting depths were similar between the persistently and variably flooded AWC wetlands. While results indicated higher root production in the shallow depths of the persistently flooded wetland, root abundance and mortality rates were similar between sites. These results are contrary to other investigations of belowground processes along hydrologic gradients in forested wetlands. Results suggest that AWC may express substantial morphological and physiological root plasticity in order to adapt to varied degrees of soil inundation

    The photodissociation and chemistry of CO isotopologues: applications to interstellar clouds and circumstellar disks

    Full text link
    Aims. Photodissociation by UV light is an important destruction mechanism for CO in many astrophysical environments, ranging from interstellar clouds to protoplanetary disks. The aim of this work is to gain a better understanding of the depth dependence and isotope-selective nature of this process. Methods. We present a photodissociation model based on recent spectroscopic data from the literature, which allows us to compute depth-dependent and isotope-selective photodissociation rates at higher accuracy than in previous work. The model includes self-shielding, mutual shielding and shielding by atomic and molecular hydrogen, and it is the first such model to include the rare isotopologues C17O and 13C17O. We couple it to a simple chemical network to analyse CO abundances in diffuse and translucent clouds, photon-dominated regions, and circumstellar disks. Results. The photodissociation rate in the unattenuated interstellar radiation field is 2.6e-10 s^-1, 30% higher than currently adopted values. Increasing the excitation temperature or the Doppler width can reduce the photodissociation rates and the isotopic selectivity by as much as a factor of three for temperatures above 100 K. The model reproduces column densities observed towards diffuse clouds and PDRs, and it offers an explanation for both the enhanced and the reduced N(12CO)/N(13CO) ratios seen in diffuse clouds. The photodissociation of C17O and 13C17O shows almost exactly the same depth dependence as that of C18O and 13C18O, respectively, so 17O and 18O are equally fractionated with respect to 16O. This supports the recent hypothesis that CO photodissociation in the solar nebula is responsible for the anomalous 17O and 18O abundances in meteorites.Comment: Accepted by A&

    Small Wins - Big Impact: Narratives from Behind the Scenes

    Get PDF
    All instructors, administrators, and researchers that have engaged in the endeavor to teach, oversee, and/or transform first-year engineering courses have a story to tell about their successes and struggles. In this workshop, we use narrative inquiry to listen to participants’ stories about first-year engineering programs. Based on the analyses of these stories and deduced patterns, a few key struggles will be teased out to guide this interactive workshop. All participants will then further tell their stories of relevant experiences. Our goal is to address struggles and disseminate successes with first-year engineering programs for adoption and adaptation. Our goal is that all attendees will leave this workshop with a better understanding of their own stories and key takeaways that they can apply to first-year engineering programs at their own institutions

    Considering the nutritional benefits and health implications of red meat in the era of meatless initiatives

    Get PDF
    Driven by perceived health and environmental benefits, initiatives to remove red meat from recommended eating patterns are increasingly being implemented in United States institutions, including schools and hospitals. While these efforts aim to address important issues, they may inadvertently lead to unintended consequences, particularly regarding essential nutrient intake for certain populations. This perspective considers the nutritional value of red meat, examines its potential health benefits, and highlights nutritional risks when intake is reduced or eliminated. Red meat is a nutrient-dense food that provides highly bioavailable protein and several essential micronutrients often lacking in the diet, including iron, zinc, and vitamin B12. These nutrients can be limited or absent in many plant-source foods as well as in some animal-source foods. Red meat’s micronutrient profile is especially valuable for young children and women of reproductive age, including pregnant women. In addition, the protein density of red meat is beneficial for individuals managing obesity and older adults at risk of sarcopenia. Many epidemiological studies suggest potential associations between excessive red meat consumption and increased risk of certain chronic diseases, but this evidence does not conclusively implicate red meat in the development or progression of chronic disease. The nutritional and health implications of reducing red meat consumption must be balanced against the low certainty of evidence used to discourage red meat intake when making dietary recommendations

    Mutations in HYAL2, Encoding Hyaluronidase 2, Cause a Syndrome of Orofacial Clefting and Cor Triatriatum Sinister in Humans and Mice.

    Get PDF
    Orofacial clefting is amongst the most common of birth defects, with both genetic and environmental components. Although numerous studies have been undertaken to investigate the complexities of the genetic etiology of this heterogeneous condition, this factor remains incompletely understood. Here, we describe mutations in the HYAL2 gene as a cause of syndromic orofacial clefting. HYAL2, encoding hyaluronidase 2, degrades extracellular hyaluronan, a critical component of the developing heart and palatal shelf matrix. Transfection assays demonstrated that the gene mutations destabilize the molecule, dramatically reducing HYAL2 protein levels. Consistent with the clinical presentation in affected individuals, investigations of Hyal2-/- mice revealed craniofacial abnormalities, including submucosal cleft palate. In addition, cor triatriatum sinister and hearing loss, identified in a proportion of Hyal2-/- mice, were also found as incompletely penetrant features in affected humans. Taken together our findings identify a new genetic cause of orofacial clefting in humans and mice, and define the first molecular cause of human cor triatriatum sinister, illustrating the fundamental importance of HYAL2 and hyaluronan turnover for normal human and mouse development

    Typha (Cattail) Invasion in North American Wetlands: Biology, Regional Problems, Impacts, Ecosystem Services, and Management

    Get PDF
    Typha is an iconic wetland plant found worldwide. Hybridization and anthropogenic disturbances have resulted in large increases in Typha abundance in wetland ecosystems throughout North America at a cost to native floral and faunal biodiversity. As demonstrated by three regional case studies, Typha is capable of rapidly colonizing habitats and forming monodominant vegetation stands due to traits such as robust size, rapid growth rate, and rhizomatic expansion. Increased nutrient inputs into wetlands and altered hydrologic regimes are among the principal anthropogenic drivers of Typha invasion. Typha is associated with a wide range of negative ecological impacts to wetland and agricultural systems, but also is linked with a variety of ecosystem services such as bioremediation and provisioning of biomass, as well as an assortment of traditional cultural uses. Numerous physical, chemical, and hydrologic control methods are used to manage invasive Typha, but results are inconsistent and multiple methods and repeated treatments often are required. While this review focuses on invasive Typha in North America, the literature cited comes from research on Typha and other invasive species from around the world. As such, many of the underlying concepts in this review are relevant to invasive species in other wetland ecosystems worldwide

    Oral abstracts of the 21st International AIDS Conference 18-22 July 2016, Durban, South Africa

    Get PDF
    The rate at which HIV-1 infected individuals progress to AIDS is highly variable and impacted by T cell immunity. CD8 T cell inhibitory molecules are up-regulated in HIV-1 infection and associate with immune dysfunction. We evaluated participants (n=122) recruited to the SPARTAC randomised clinical trial to determine whether CD8 T cell exhaustion markers PD-1, Lag-3 and Tim-3 were associated with immune activation and disease progression.Expression of PD-1, Tim-3, Lag-3 and CD38 on CD8 T cells from the closest pre-therapy time-point to seroconversion was measured by flow cytometry, and correlated with surrogate markers of HIV-1 disease (HIV-1 plasma viral load (pVL) and CD4 T cell count) and the trial endpoint (time to CD4 count <350 cells/μl or initiation of antiretroviral therapy). To explore the functional significance of these markers, co-expression of Eomes, T-bet and CD39 was assessed.Expression of PD-1 on CD8 and CD38 CD8 T cells correlated with pVL and CD4 count at baseline, and predicted time to the trial endpoint. Lag-3 expression was associated with pVL but not CD4 count. For all exhaustion markers, expression of CD38 on CD8 T cells increased the strength of associations. In Cox models, progression to the trial endpoint was most marked for PD-1/CD38 co-expressing cells, with evidence for a stronger effect within 12 weeks from confirmed diagnosis of PHI. The effect of PD-1 and Lag-3 expression on CD8 T cells retained statistical significance in Cox proportional hazards models including antiretroviral therapy and CD4 count, but not pVL as co-variants.Expression of ‘exhaustion’ or ‘immune checkpoint’ markers in early HIV-1 infection is associated with clinical progression and is impacted by immune activation and the duration of infection. New markers to identify exhausted T cells and novel interventions to reverse exhaustion may inform the development of novel immunotherapeutic approaches

    Edible films and coatings as carriers of living microorganisms: a new strategy towards biopreservation and healthier foods

    Get PDF
    Edible films and coatings have been extensively studied in recent years due to their unique properties and advantages over more traditional conservation techniques. Edible films and coatings improve shelf life and food quality, by providing a protective barrier against physical and mechanical damage, and by creating a controlled atmosphere and acting as a semipermeable barrier for gases, vapor, and water. Edible films and coatings are produced using naturally derived materials, such as polysaccharides, proteins, and lipids, or a mixture of these materials. These films and coatings also offer the possibility of incorporating different functional ingredients such as nutraceuticals, antioxidants, antimicrobials, flavoring, and coloring agents. Films and coatings are also able to incorporate living microorganisms. In the last decade, several works reported the incorporation of bacteria to confer probiotic or antimicrobial properties to these films and coatings. The incorporation of probiotic bacteria in films and coatings allows them to reach the consumers gut in adequate amounts to confer health benefits to the host, thus creating an added value to the food product. Also, other microorganisms, either bacteria or yeast, can be incorporated into edible films in a biocontrol approach to extend the shelf life of food products. The incorporation of yeasts in films and coatings has been suggested primarily for the control of the postharvest disease. This work provides a comprehensive review of the use of edible films and coatings for the incorporation of living microorganisms, aiming at the biopreservation and probiotic ability of food products.Ana Guimaraes received support through grant SFRH/BD/ 103245/2014 from the Portuguese Foundation for Science and Technology (FCT). Luís Abrunhosa was supported by grant UMINHO/BPD/51/2015 from project UID/BIO/04469/2013 financed by FCT/MEC (OE). This study was supported by FCT under the scope of the strategic funding of UID/BIO/04469/2013 unit and COMPETE 2020 (POCI-01-0145-FEDER-006684), and of BioTecNorte operation (NORTE-01-0145-FEDER000004) funded by European Regional Development Fund under the scope of Norte2020 - Programa Operacional Regional do Norte. Vectors used in Figure were designed by Freepik.info:eu-repo/semantics/publishedVersio
    corecore