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

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

Zika virus protection by a single low dose nucleoside modified mRNA vaccination

Zika virus (ZIKV) has recently emerged as an explosive pandemic associated with severe neuropathology in newborns and adults1. There are no ZIKV-specific treatments or preventatives; thus, development of a safe and effective vaccine is a high priority. Messenger RNA (mRNA) has emerged as a versatile and highly effective platform to deliver vaccine antigens and therapeutic proteins2,3. Here, we demonstrate that a single low-dose intradermal immunization with lipid nanoparticle-encapsulated nucleoside-modified mRNA (mRNA-LNP) encoding the pre-membrane and envelope (prM-E) glycoproteins of a 2013 ZIKV outbreak strain elicited potent and durable neutralizing antibody responses in mice and non-human primates. Immunization with 30 μg of nucleoside-modified ZIKV mRNA-LNPs protected mice from ZIKV challenges at 2 weeks or 5 months post-vaccination, and a single dose of 50 μg was sufficient to protect non-human primates from a challenge at 5 weeks post-vaccination. These data demonstrate that nucleoside-modified mRNA-LNPs elicit rapid and durable protective immunity and thus represent a new and promising vaccine candidate for the global fight against ZIKV

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

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

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

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

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

How fire and climate shaped grass-dominated vegetation and forest mosaics in northern South Africa during past millennia

Grassland and savanna are globally important ecosystems, both ecologically and economically. These grass-dominated systems are at risk from current and future climate change and increasing anthropogenic impact. Key questions for understanding the resilience and variability of grass-dominated ecosystems under current and future environmental conditions include: How have these systems responded to climate change and disturbance in the past? What are the principal driving agents responsible for their present-day composition and distribution? Do the palaeoecological data provide evidence for feedbacks between climate, fire and anthropogenic activities? In this study, the temporal dynamics of grassland, savanna and forest in the summer rainfall region of northern South Africa were reconstructed for the last ~6500 years. Palaeoecological techniques used include analyses of fossil pollen, charcoal and stable isotopes. Data from two sites located at the present-day grassland-savanna ecotone in Mpumalanga province of South Africa are reported. Results indicate that a mosaic of grassland, savanna and Podocarpus forest occupied the landscape throughout the late Holocene, with grassland and forest dominating higher altitudes, and savanna and forest lower altitudes. Podocarpus forest retreated and grass-dominated vegetation expanded its range around 1800 cal. yr BP at the lower altitude site (Lowveld) and 600 cal. yr BP at the higher altitude site (Highveld), representing a change from a stable state forest savanna/grassland mosaic to an increasingly grass-dominated system. Climatic stress, changes in fire regime and anthropogenic impact led to the vegetation transitions recorded, and resulted in changes in water and nutrient cycles. In an increasingly warm world, with fluctuating water availability and heightened anthropogenic use of natural resources, the future of grass-dominated ecosystems appears far from stable