Meiofaunal ecology in harsh environments: refugia and stepping stones, a case study in a deglaciating Alpine area

Climate change and progressive glacier loss are leading to rapid ecological shifts in alpine aquatic systems. Rock glaciers and paraglacial features such as proglacial lakes, moraines, and taluses can alter the gradients of glacial influence along alpine river networks. Particularly relevant is the effect of rock glacial streams on invertebrates, although the hydrology and ecology of such high-elevation stream types is still scarcely known. We investigated the main meiofaunal component of benthic communities of different stream types in a deglaciating area of the Italian Alps, i.e., Crustacea Copepoda. We used an index of habitat mildness based on water temperature, channel stability, turbidity, and organic detritus, to measure the difference in community metrics over a gradient of habitat amelioration, driven by the mixing of distinct stream types (glacial, rock-glacial, snowmelt, mixed) and their interactions with paraglacial features. The composition of copepod communities of rock-glacial sites differed from the one of the other stream types, particularly it was very different from the kryal sites, and more similar to the rhithral and krenal ones. Under progressive deglaciation, rock glaciers and paraglacial features will increasingly influence the meiofaunal communities of alpine river networks. As they host a higher number of taxa and individuals than non-glacial locations, rock glacial streams may act as stepping stones facilitating colonization following glacier retreat. After glacier loss, rock glacial streams may represent climate refugia for cold adapted taxa and/or kryal specialists, because the slow thawing of their ice might sustain cold water conditions for a longer period of time

Técnica de criação de Anastrepha fraterculus (Wied., 1830) (Diptera: Tephritidae) em laboratório utilizando hospedeiro natural.

Uma técnica para criação de todas as fases de desenvolvimento da mosca-das-frutas sul-americana, Anastrepha fraterculus (Wied., 1830) (Diptera: Tephritidae), em laboratório (T 24 ± 2°C; UR 70 ± 10% e fotofase 16 horas) utilizando dieta natural foi avaliada e descrita. Os adultos foram criados em gaiolas plásticas de polietileno transparente (41 x 29,5 x 30 cm) e alimentados com dieta artificial contendo extrato de soja, açúcar mascavo e gérmen de trigo, nas proporções de 3:1:1, além de água. Em cada gaiola, foi utilizada uma densidade média de 167 ± 25 casais. As fêmeas ovipositaram em frutos de mamão-papaia (Carica papaya L.) trocados a intervalos de 48 horas e mantidos em caixas plásticas (37 x 14 x 29 cm) com fundo coberto por vermiculita. Sobre a camada de vermiculita, foi colocada uma tela plástica de malha de 2 mm, para facilitar a retirada dos restos de mamão desidratado após o desenvolvimento larval. As larvas completaram o desenvolvimento no mamão passando à fase de pupa após 15 ± 2 dias. Em cada mamão (401 ± 16 gramas), foram coletadas 168 ± 27 pupas, obtendo-se 385 ± 44 pupas (viabilidade de 95 ± 2%) por semana, com peso médio de 1,33 ± 0,05 gramas a cada 100 pupas. Os insetos obtidos podem ser destinados a condução de bioensaios ou na manutenção da criação. A metodologia descrita permite o desenvolvimento de uma geração (ovo-adulto) a cada 32 ± 2 dias, perfazendo aproximadamente 11 gerações/ano.bitstream/item/31529/1/bop015.pd

How the innovation diffusion models from the past can help us to explain marketing in the new media era

Even if the rhetoric of the Internet and the new digital media seems to have radically changed our technological environment, historical recurrences are relevant tools in order to analyze the future marketing. We propose a new multi-stage model able to bridge two different approaches, namely the adoption models à la Bass and the recent line of research concerning agent-based innovation diffusion models. Our technology allows us to find a closed form equation for awareness and adoption, taking into account heterogeneous population

A two-stage model for diffusion of innovations

The objective of this paper is to provide an analytical framework to study the whole process of diffusion of innovations, new products or ideas: we take into account knowledge transfer in a complex society, decisional process for adoption and key features in the spread of new technologies. For this purpose, we propose a probabilistic model based on an interacting population connected through new communication channels (such as social media) where potential adopters are linked with each other at different connection degrees. Our diffusion curve is the result of an emotion driven decision process following the awareness phase. Finally, we are able to recover stylized facts highlighted by the extant literature in the field

Preliminary results on the evolution of proglacial ponds in the deglaciating Alps

Deglaciation is one of the most evident effects of the ongoing climatic changes on the Alpine environment. One of its common consequences is the formation of new water bodies in the proglacial area, where proglacial lakes and ponds are increasingly relevant ecosystems for the mountain landscape. The EVERLAKE project focuses on a recent system of proglacial ponds that originated from the retreat of the Zufall/Cevedale Glacier (Plima catchment, Central/Eastern Italian Alps). The aims of the project are to: (i) provide a first hydroecological characterisation of these pond ecosystems from a physical, chemical and biological point of view; (ii) understand their evolutionary trend during the process of deglaciation, with a space-for-time substitution approach. Here, we present data collected during the ice-free season 2022, showing the seasonal development occurring in three ponds located along a gradient of distance from the Cevedale Glacier terminus (i.e., at 2700-2900 m a.s.l.). We monitored water level, temperature and electrical conductivity and assessed the origin of water through analyses of stable isotopes (δ2H, δ18O). Bathymetric measurements were performed to estimate the residence time of each waterbody. We also analysed basic water chemistry, concentrations of trace elements, benthic and planktonic chlorophyll-a and organic content. The biological communities of these poorly known aquatic ecosystems were characterised by adopting an integrated approach combining morphological observations of microalgae and 16S and 18S rRNA metabarcoding of eDNA from both benthic and planktonic samples. The ponds showed different ecological conditions related to their distance from the glacier margins

Plasmopara viticola infection affects mineral elements allocation and distribution in Vitis vinifera leaves

Plasmopara viticola is one of the most important pathogens infecting Vitis vinifera plants. The interactions among P. viticola and both susceptible and resistant grapevine plants have been extensively characterised, at transcriptomic, proteomic and metabolomic levels. However, the involvement of plants ionome in the response against the pathogen has been completely neglected so far. Therefore, this study was aimed at investigating the possible role of leaf ionomic modulation during compatible and incompatible interactions between P. viticola and grapevine plants. In susceptible cultivars, a dramatic redistribution of mineral elements has been observed, thus uncovering a possible role for mineral nutrients in the response against pathogens. On the contrary, the resistant cultivars did not present substantial rearrangement of mineral elements at leaf level, except for manganese (Mn) and iron (Fe). This might demonstrate that, resistant cultivars, albeit expressing the resistance gene, still exploit a pathogen response mechanism based on the local increase in the concentration of microelements, which are involved in the synthesis of secondary metabolites and reactive oxygen species. Moreover, these data also highlight the link between the mineral nutrition and plants\u2019 response to pathogens, further stressing that appropriate fertilization strategies can be fundamental for the expression of response mechanisms against pathogens

Inelastic Black Hole Scattering from Charged Scalar Amplitudes

We explain how the lowest-order classical gravitational radiation produced during the inelastic scattering of two Schwarzschild black holes in General Relativity can be obtained from a tree scattering amplitude in gauge theory coupled to scalar fields. The gauge calculation is related to gravity through the double copy. We remove unwanted scalar forces which can occur in the double copy by introducing a massless scalar in the gauge theory, which is treated as a ghost in the link to gravity. We hope these methods are a step towards a direct application of the double copy at higher orders in classical perturbation theory, with the potential to greatly streamline gravity calculations for phenomenological applications.Comment: 28 pages, 6 figure

The Kerr-Schild double copy in curved spacetime

We thank Tim Adamo, Ricardo Monteiro and Donal O’Connell for discussions and / or comments on the manuscript. CDW and NBA are supported by the U.K. Science and Technology Facilities Council (STFC). AL is funded by a Conacyt studentship, and thanks Queen Mary University of London for hospitalit

Biodegradable drifting fish aggregating devices: Current status and future prospects

The structure, materials and designs of drifting Fish Aggregating Devices (dFADs) have generally remained rudimentary and relatively unchanged since they first came into use in the 1980 s. However, more recently, dFADs have been increasing in dimensions and the prevailing use of plastic components. Abandoned, lost or discarded dFADs can therefore contribute to the global marine litter problem. Transitioning to biodegradable and non-toxic materials that have a faster rate of decomposition, and are free of toxins and heavy metals, relative to synthetic materials, has been prescribed as an important part of the solution to reducing marine pollution from industrial tuna fisheries that rely on dFADs. This review of the current state of dFADs considers aspects related to the use of biodegradable materials in their construction, including; regulations related to dFAD materials, trials of biodegradable designs and materials and future alternatives. During the last decade, regulatory measures at tuna Regional Fishery Management Organizations (tRFMOs) have gradually moved towards the clear recommendation to use biodegradable materials in dFAD construction together with other measures limiting the number of active dFADs and the use of netting materials. However, to provide operational guidance, more clarity is needed, starting with a standardised definition of biodegradable dFADs among tRFMOs. Research involving dFAD natural and synthetic materials is required, along with improved data collection for monitoring the transition of dFAD materials against specified standards for biodegradable dFADs. In addition, alternative and complementary actions need to be explored to contribute to minimising adverse effects of dFADs on the environment. Acknowledging the current difficulties for the implementation of fully biodegradable dFADs in tuna fisheries, a stepwise process towards the implementation of commercially viable biodegradable dFADs should be considered.Peer reviewe