50 research outputs found

    A Battle Lost? Report on Two Centuries of Invasion and Management of Lantana camara L. in Australia, India and South Africa

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    Recent discussion on invasive species has invigorated the debate on strategies to manage these species. Lantana camara L., a shrub native to the American tropics, has become one of the worst weeds in recorded history. In Australia, India and South Africa, Lantana has become very widespread occupying millions of hectares of land. Here, we examine historical records to reconstruct invasion and management of Lantana over two centuries and ask: Can we fight the spread of invasive species or do we need to develop strategies for their adaptive management? We carried out extensive research of historical records constituting over 75% of records on invasion and management of this species in the three countries. The records indicate that governments in Australia, India and South Africa have taken aggressive measures to eradicate Lantana over the last two centuries, but these efforts have been largely unsuccessful. We found that despite control measures, the invasion trajectory of Lantana has continued upwards and that post-war land-use change might have been a possible trigger for this spread. A large majority of studies on invasive species address timescales of less than one year; and even fewer address timescales of >10 years. An understanding of species invasions over long time-scales is of paramount importance. While archival records may give only a partial picture of the spread and management of invasive species, in the absence of any other long-term dataset on the ecology of Lantana, our study provides an important insight into its invasion, spread and management over two centuries and across three continents. While the established paradigm is to expend available resources on attempting to eradicate invasive species, our findings suggest that in the future, conservationists will need to develop strategies for their adaptive management rather than fighting a losing battle

    CropPol: a dynamic, open and global database on crop pollination

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    Seventy five percent of the world's food crops benefit from insect pollination. Hence, there has been increased interest in how global change drivers impact this critical ecosystem service. Because standardized data on crop pollination are rarely available, we are limited in our capacity to understand the variation in pollination benefits to crop yield, as well as to anticipate changes in this service, develop predictions, and inform management actions. Here, we present CropPol, a dynamic, open and global database on crop pollination. It contains measurements recorded from 202 crop studies, covering 3,394 field observations, 2,552 yield measurements (i.e. berry weight, number of fruits and kg per hectare, among others), and 47,752 insect records from 48 commercial crops distributed around the globe. CropPol comprises 32 of the 87 leading global crops and commodities that are pollinator dependent. Malus domestica is the most represented crop (32 studies), followed by Brassica napus (22 studies), Vaccinium corymbosum (13 studies), and Citrullus lanatus (12 studies). The most abundant pollinator guilds recorded are honey bees (34.22% counts), bumblebees (19.19%), flies other than Syrphidae and Bombyliidae (13.18%), other wild bees (13.13%), beetles (10.97%), Syrphidae (4.87%), and Bombyliidae (0.05%). Locations comprise 34 countries distributed among Europe (76 studies), Northern America (60), Latin America and the Caribbean (29), Asia (20), Oceania (10), and Africa (7). Sampling spans three decades and is concentrated on 2001-05 (21 studies), 2006-10 (40), 2011-15 (88), and 2016-20 (50). This is the most comprehensive open global data set on measurements of crop flower visitors, crop pollinators and pollination to date, and we encourage researchers to add more datasets to this database in the future. This data set is released for non-commercial use only. Credits should be given to this paper (i.e., proper citation), and the products generated with this database should be shared under the same license terms (CC BY-NC-SA). This article is protected by copyright. All rights reserved

    The Effect Of Maternal Antibodies On Anti-Viral Immunity In Infant Mice

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    Infants are particularly vulnerable to infection and severe disease, yet we lack effective vaccines for this population. While maternal antibodies can provide protection, they also inhibit the infant’s de novo antibody response. Furthermore, maternal antibodies can exacerbate disease in some contexts. Thus we need better vaccination strategies to protect infants. Here, we establish mouse models of influenza virus- and flavivirus-specific maternal antibody transfer. We show that influenza virus-specific maternal antibodies protect infant mice from influenza disease and that Zika virus-specific maternal antibodies protect infants from Zika virus-mediated disease. Dengue virus-specific maternal antibodies neither protect from nor exacerbate disease during Zika virus infection of infant mice. We further demonstrate that influenza virus-specific maternal antibodies inhibit infants’ responses to conventional influenza vaccines. To solve this problem, we show that a novel vaccine, nucleoside-modified mRNA encapsulated in lipid nanoparticles (mRNA-LNP) encoding influenza hemagglutinin, overcomes maternal antibody inhibition by prolonged establishment of germinal centers. mRNA-LNP vaccination offers a promising means of eliciting protective immune responses in infants in the presence of maternal antibodies. These results have important implications for the design of vaccines for use in mothers and infants

    The Effect of Maternal Antibodies on Anti-viral Immunity in Infant Mice

    No full text
    Infants are particularly vulnerable to infection and severe disease, yet we lack effective vaccines for this population. While maternal antibodies can provide protection, they also inhibit the infant’s de novo antibody response. Furthermore, maternal antibodies can exacerbate disease in some contexts. Thus we need better vaccination strategies to protect infants. Here, we establish mouse models of influenza virus- and flavivirus-specific maternal antibody transfer. We show that influenza virus-specific maternal antibodies protect infant mice from influenza disease and that Zika virus-specific maternal antibodies protect infants from Zika virus-mediated disease. Dengue virus-specific maternal antibodies neither protect from nor exacerbate disease during Zika virus infection of infant mice. We further demonstrate that influenza virus-specific maternal antibodies inhibit infants’ responses to conventional influenza vaccines. To solve this problem, we show that a novel vaccine, nucleoside-modified mRNA encapsulated in lipid nanoparticles (mRNA-LNP) encoding influenza hemagglutinin, overcomes maternal antibody inhibition by prolonged establishment of germinal centers. mRNA-LNP vaccination offers a promising means of eliciting protective immune responses in infants in the presence of maternal antibodies. These results have important implications for the design of vaccines for use in mothers and infants

    The Effect Of Maternal Antibodies On Anti-Viral Immunity In Infant Mice

    No full text
    Infants are particularly vulnerable to infection and severe disease, yet we lack effective vaccines for this population. While maternal antibodies can provide protection, they also inhibit the infant’s de novo antibody response. Furthermore, maternal antibodies can exacerbate disease in some contexts. Thus we need better vaccination strategies to protect infants. Here, we establish mouse models of influenza virus- and flavivirus-specific maternal antibody transfer. We show that influenza virus-specific maternal antibodies protect infant mice from influenza disease and that Zika virus-specific maternal antibodies protect infants from Zika virus-mediated disease. Dengue virus-specific maternal antibodies neither protect from nor exacerbate disease during Zika virus infection of infant mice. We further demonstrate that influenza virus-specific maternal antibodies inhibit infants’ responses to conventional influenza vaccines. To solve this problem, we show that a novel vaccine, nucleoside-modified mRNA encapsulated in lipid nanoparticles (mRNA-LNP) encoding influenza hemagglutinin, overcomes maternal antibody inhibition by prolonged establishment of germinal centers. mRNA-LNP vaccination offers a promising means of eliciting protective immune responses in infants in the presence of maternal antibodies. These results have important implications for the design of vaccines for use in mothers and infants

    Identifying the optimal safety leader: a person-centered approach

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    PurposeThe research aimed to uncover leader profiles based on combinations of transformational (TFL), transactional (TAL) and passive leadership (PAL) and to examine how such constellations affect safety. Leader adaptability was tested as an antecedent of leader profiles.Design/methodology/approachUsing latent profile analysis, the effect of different leader profiles on workplace safety was investigated in two survey studies.FindingsIn total, four leader profiles emerged: “active,” “stable-moderate,” “passive-avoidant” and “inconsistent” leader. A stable-moderate leader profile was identified as the optimal leader profile for safety performance. Leader adaptability was identified as a predictor of leader profile membership.Practical implicationsSafety leadership development should focus on training managers in optimal combinations of leadership practices.Originality/valueThe research calls into question the existence of a transformational or transactional leader. The findings suggest that higher frequency of leadership practices is not always more beneficial for workplace safety
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