The path towards herd immunity: Predicting COVID-19 vaccination uptake through results from a stated choice study across six continents.

Despite unprecedented progress in developing COVID-19 vaccines, global vaccination levels needed to reach herd immunity remain a distant target, while new variants keep emerging. Obtaining near universal vaccine uptake relies on understanding and addressing vaccine resistance. Simple questions about vaccine acceptance however ignore that the vaccines being offered vary across countries and even population subgroups, and differ in terms of efficacy and side effects. By using advanced discrete choice models estimated on stated choice data collected in 18 countries/territories across six continents, we show a substantial influence of vaccine characteristics. Uptake increases if more efficacious vaccines (95% vs 60%) are offered (mean across study areas = 3.9%, range of 0.6%-8.1%) or if vaccines offer at least 12 months of protection (mean across study areas = 2.4%, range of 0.2%-5.8%), while an increase in severe side effects (from 0.001% to 0.01%) leads to reduced uptake (mean = -1.3%, range of -0.2% to -3.9%). Additionally, a large share of individuals (mean = 55.2%, range of 28%-75.8%) would delay vaccination by 3 months to obtain a more efficacious (95% vs 60%) vaccine, where this increases further if the low efficacy vaccine has a higher risk (0.01% instead of 0.001%) of severe side effects (mean = 65.9%, range of 41.4%-86.5%). Our work highlights that careful consideration of which vaccines to offer can be beneficial. In support of this, we provide an interactive tool to predict uptake in a country as a function of the vaccines being deployed, and also depending on the levels of infectiousness and severity of circulating variants of COVID-19.

Assessment of sustainable land management practices in Mediterranean rural regions.

Sustainable land management practices can be suitable vehicles to simultaneously address the causes and consequences of land degradation, desertification, and climate change in land managed systems. Here, we assess the potential of a variety of sustainable land management practices that, beyond addressing specific and local issues, assist in tackling Mediterranean Basin-wide land-use challenges. With this work, we aim to highlight those options that simultaneously promote local and regional Basin-wide adaptation. To do that, we developed a novel multi-objective assessment that evaluates the effectiveness of 104 practices adopted within the Mediterranean Basin and documented in the World Overview of Conservation Approaches and Technologies global database. Results indicate that agroforestry and green covers in perennial woody crops can promote multiple ecosystem services while addressing climate change adaptation. We further argue that these two practices together with reforestation, assist in regulating the hydrological cycle of the Basin and in maintaining its multifunctional landscape. Lastly, we reflect on potential biophysical and socio-economic barriers and opportunities associated with the implementation of the three practices. Our approach provides a Basin-wide integrated view that facilitates the coordination of sustainable management strategies across the Mediterranean region.

Physiological, anatomical and biomass partitioning responses to ozone in the Mediterranean endemic plant Lamottea dianae.

Ozone effects on the perennial forb Lamottea dianae were studied in an open-top chamber experiment. Ozone was found to induce reductions in CO2 assimilation and water use efficiency in the leaves of this species. These reductions were mainly related to a decline in the in vivo CO2 fixation capacity of Rubisco (V(c,max)), rather than to stomatal limitations or photoinhibitory damage (F(v):F(m)). In addition to chloroplast degeneration, other observed effects were callose accumulation, formation of pectinaceous wart-like cell wall exudates and phloem alterations. Moreover, ozone exposure significantly reduced root dry biomass. The possible relevance of these adverse effects for Mediterranean forbs is commented. These results show that endemic plants can be very sensitive to ozone, suggesting that risks associated with this pollutant should be taken into account for conservation purposes.

Responses of evergreen and deciduous Quercus species to enhanced ozone levels.

Plants of one evergreen oak (Quercus ilex) and three deciduous oaks (Q. faginea, with small leaves; Q. pyrenaica and Q. robur, with large leaves) were exposed both to filtered air and to enhanced ozone levels in Open-Top Chambers. Q. faginea and Q. pyrenaica were studied for the first time. Based on visible injury, gas exchange, chlorophyll content and biomass responses, Q. pyrenaica was the most sensitive species, and Q. ilex was the most tolerant, followed by Q. faginea. Functional leaf traits of the species were related to differences in sensitivity, while accumulated ozone flux via stomata (POD1.6) partly contributed to the observed differences. For risk assessment of Mediterranean vegetation, the diversity of responses detected in this study should be taken into account, applying appropriate critical levels.

Contrasting ozone sensitivity in related evergreen and deciduous shrubs.

Plant responses to enhanced ozone levels have been studied in two pairs of evergreen-deciduous species (Pistacia terebinthus vs. P. lentiscus; Viburnum lantana vs. V. tinus) in Open Top Chambers. Ozone induced widespread visible injury, significantly reduced CO(2) assimilation and stomatal conductance (g(s)), impaired Rubisco efficiency and regeneration capacity (V(c,max,)J(max)) and altered fluorescence parameters only in the deciduous species. Differences in stomatal conductance could not explain the observed differences in sensitivity. In control plants, deciduous species showed higher superoxide dismutase (SOD) activity than their evergreen counterparts, suggesting metabolic differences that could make them more prone to redox imbalances. Ozone induced increases in SOD and/or peroxidase activities in all the species, but only evergreens were able to cope with the oxidative stress. The relevancy of these results for the effective ozone flux approach and for the current ozone Critical Levels is also discussed.

Visible and microscopic needle alterations of mature Aleppo pine (Pinus halepensis) trees growing on an ozone gradient in eastern Spain.

Visible injuries and 42 microscopic features of tissue and cell structure were quantified in needles of mature Aleppo pine (Pinus halepensis) growing at four field sites located on a natural ozone gradient in eastern Spain. Principal component analysis was used to find out if the forest sites differed from each other, to determine the reasons for the site differences and to evaluate the relations between the parameters studied. In previous-year needles, the first principal component (PC) was described by changes typical of long-term ozone stress: high occurrence of microscopic changes indicating increased defence and faint chlorotic mottling, but low occurrence of ultrastructural changes related to photosynthesis and its storage products. The second PC was described by needle ageing or ontological senescence. Statistical differences between the sites in terms of ozone stress were found and were in line with measured ozone concentrations and the values of the ozone exposure index, AOT40. Symptoms of ozone stress were mild, i.e., not related to severe tissue damage. Results suggested that the faint chlorotic mottling can be attributed to certain forms of condensed tannins or small chloroplasts. In addition, a coastal site differed from mountainous sites by having a more mesomorphic needle anatomy.

Deciduous shrubs for ozone bioindication: Hibiscus syriacus as an example.

Ozone-like visible injury was detected on Hibiscus syriacus plants used as ornamental hedges. Weekly spray of the antiozonant ethylenediurea (EDU, 300ppm) confirmed that the injury was induced by ambient ozone. EDU induced a 75% reduction in visible injury. Injury was more severe on the western than on the eastern exposure of the hedge. This factor of variability should be considered in ozone biomonitoring programmes. Seeds were collected and seedlings were artificially exposed to ozone in filtered vs. not-filtered (+30ppb) Open-Top Chambers. The level of exposure inducing visible injury in the OTC seedlings was lower than that in the ambient-grown hedge. The occurrence of visible injury in the OTC confirmed that the ozone sensitivity was heritable and suggested that symptomatic plants of this deciduous shrub population can be successfully used as ozone bioindicators. EDU is recommended as a simple tool for diagnosing ambient ozone visible injury on field vegetation.

Ozone and forests in South-Western Europe--What have we learned?

Monitoring of forest condition and ozone (O3) at 83 sites in France, Italy, Luxenbourg, Spain and Switzerland resulted in a number of findings in relation to the knowledge of O3 exposure (concentration and cumulative AOT40), feasibility of the assessment of stomatal O3 flux and relationships between O3 and crown defoliation of beech and visible symptoms on native vegetation. However, the project provides evidence of issues to be addressed within the current monitoring system (data quality, validation sites and response indicators) and indications as to how the monitoring of O3 risk in the context of an effect-oriented monitoring program can be improved.

Ozone and forests in South-Western Europe.

The paper provides basic information about background, objectives and structure of O3SWE (Ozone at the permanent monitoring plots in South-Western Europe), an international co-operative project aimed at evaluating O3 concentrations, cumulative exposure, uptake and effects on forest vegetation in four countries of South-Western Europe (France, Italy, Luxenbourg, Spain and Switzerland). The project covers a total of 83 permanent plots of the EU and UN/ECE intensive forest monitoring programme and span over three years of investigation (2000-2002). The O3SWE project aims to demonstrate how, using data collected routinely in an intensive forest monitoring network, O3 exposure, flux and effects can be assessed and exceedances critically evaluated.

Tradescantia micronucleus test indicates genotoxic potential of traffic emissions in European cities.

Urban atmospheres contain complex mixtures of air pollutants including mutagenic and carcinogenic substances such as benzene, diesel soot, heavy metals and polycyclic aromatic hydrocarbons. In the frame of a European network for the assessment of air quality by the use of bioindicator plants, the Tradescantia micronucleus (Trad-MCN) test was applied to examine the genotoxicity of urban air pollution. Cuttings of Tradescantia clone #4430 were exposed to ambient air at 65 monitoring sites in 10 conurbations employing a standardised methodology. The tests revealed an elevated genotoxic potential mainly at those urban sites which were exposed to severe car traffic emissions. This bioassay proved to be a suitable tool to detect local 'hot spots' of mutagenic air pollution in urban areas. For its use in routine monitoring programmes, however, further standardisation of cultivation and exposure techniques is recommended in order to reduce the variability of results due to varying environmental conditions.

Studies on the structure of the plant wax nonacosan-10-ol, the main component of epicuticular wax conifers.

The main component presents in the epicuticular waxes of needles of Pinus halepensis and the most of conifers, the secondary alcohol nonacosan-10-ol, has been investigated by X-ray diffraction and differential scanning calorimetry. The results obtained from these physical techniques permitted to establish a definitive structural model of the molecular arrangement of this wax, basically in good agreement with the model formulated by other authors from theoretical formulations. Biological implications of the proposed structure have been also formulated.