Фотолиз гетеросистем "азид свинца - кадмий"

Масс-спектрометрическим и спектрофотометрическим методами исследованы кинетические и спектральные закономерности формирования продуктов фотолиза гетеросистем PbN[6](Ам)-Cd в зависимости от интенсивности падающего света (1·10{13}…1·10{16} см{-2}·с{-1}).Создание гетеросистем PbN[6](Ам)-Cd наряду с уменьшением скорости фотолиза и фототока в области собственного поглощения PbN[6](Ам) приводит к расширению области спектральной чувствительности азида свинца, а предварительная обработка их светом lambda=365 нм - к увеличению скорости фотолиза. В результате анализа вольтамперных характеристик, контактной фотоЭДС, контактной разности потенциалов построена диаграмма энергетических зон и предложена модель фотолиза гетеросистем PbN[6](Ам)-Cd, включающая: генерацию, рекомбинацию, перераспределение неравновесных носителей в контактном поле, формирование микрогетерогенных систем PbN[6](Ам)-Pb (продукт фотолиза) и образование азота

Material Around the Centaur (2060) Chiron from the 2018 November 28 UT Stellar Occultation

A stellar occultation of Gaia DR3 2646598228351156352 by the Centaur (2060) Chiron was observed from the South African Astronomical Observatory on 2018 November 28 UT. Here we present a positive detection of material surrounding Chiron from the 74-in telescope for this event. Additionally, a global atmosphere is ruled out at the tens of mircobar level for several possible atmospheric compositions. There are multiple 3-sigma drops in the 74-in light curve: three during immersion and two during emersion. Occulting material is located between 242-270 km from the center of the nucleus in the sky plane. Assuming the ring-plane orientation proposed for Chiron from the 2011 occultation, the flux drops are located at 352, 344, and 316 km (immersion), and 357, and 364 km (emersion) from the center, with normal optical depths of 0.26, 0.36, and 0.22 (immersion) and 0.26 and 0.18 (emersion), and equivalent widths between 0.7-1.3 km. This detection is similar to the previously proposed two-ring system and is located within the error bars of that ring-pole plane; however, the normal optical depths are less than half of the previous values, and three features are detected on immersion. These results suggest that the properties of the surrounding material have evolved between the 2011, 2018, and 2022 observations.Comment: Accepted by the Planetary Science Journal 21 Oct. 2023; 13 pages, 9 figures, 4 table

Invasive alien species – framework for the identification of invasive alien species of EU concern

Invasive alien species (IAS) are considered to be one of the greatest threats to biodiversity, particularly through their interactions with other drivers of change (MEA 2005, GBO 2011). In recent years the European Commission (EC) has intensified their commitment to provide a comprehensive, problem-oriented, well-balanced and manageable solution to IAS in Europe. The text of a European Union (EU) Regulation is expected to be adopted soon. A core component of the Regulation is a list of “IAS of EU concern” that will be drawn up together with European Member States (MS), based on scientifically robust risk assessments as laid down in the Regulation. Risk assessment is the technical and objective process of evaluating biological or other scientific and economic evidence to identify potentially invasive alien species and determine the level of invasion risk associated with a species or pathway and specifically whether an alien species will become invasive. An effective and robust risk assessment method is seen as an essential component of IAS management (Shine, Kettunen et al. 2010) and a fundamental element of an early warning and information system in Europe (Genovesi, Scalera et al. 2010). The purpose of this project was to provide a review of available IAS risk analysis protocols and use this, coupled with expert opinion, to inform the development of minimum standards necessary to ensure effective risk assessment methods for the EU. Additionally we considered gaps in knowledge and scope of existing risk analysis methods. Thus, we provide recommendations for developing existing risk analysis methods within a framework of minimum standards. Methods compliant with the minimum standards will be of value for supporting the development of a draft list of “IAS of EU concern”. Such a list should include species that are already established within the EU but also be extended to a scoping study to consider species that are not yet established but that may present a significant threat to Europe in the near future. Task 1: Literature review and critical assessment of existing risk assessment methodologies on IAS The purpose of the review was to critically assess the scope, robustness and effectiveness of current risk assessment methods and to provide information for their further development in the context of the study particularly underpinning the derivation of minimum standards. More than 100 relevant publications were derived through a literature search. Only 70 publications provided original risk assessment protocols and their applications and of these 29 were selected through filtering to eliminate those which simply described the implementation of an existing protocol to a given geographic region or specific taxonomic groups without modification of the assessment protocol. These 29 protocols were examined further to derive key attributes of the risk assessment method to inform the development of minimum standards. Basic information for all 29 risk assessment methods was provided. Case studies for 14 of these protocols were included to provide further context for subsequent tasks. The 14 protocols included as case studies were selected on the basis of a number of criteria: relevance of the protocol to Europe, taxonomic breadth and/or geographic breadth, likely compliance with minimum standards and availability of experts with key involvement in the protocol to provide the case study. At both the international and regional-level as well as among countries, there is huge variation in how the risks posed by alien species are assessed. Indeed risk assessment protocols vary widely in approach, objective, implementation and taxa covered, the majority are based on qualitative methods, even though the need to develop quantitative risk assessments has been recognised. Major hurdles preventing the use of quantitative risk assessment methods are the lack of data and challenges in interpretation and communication. Two critical gaps were identified through this task: consideration of ecosystem services and evaluation of user-friendliness and consistency of outcomes. Very few risk assessment protocols reviewed specifically considered impacts on ecosystem services. Consistency in risk analysis has been recently discussed and assessed for pest risk analyses in the EU-funded project PRATIQUE and methods to improve consistency have been developed. PRATIQUE only considered the EPPO decision support scheme (EPPO DSS), however this work will be extended through consideration of additional risk assessments within the current EU-funded COST Action Alien Challenge. Task 2: Develop minimum standards for risk assessment methodologies The review of characteristics of risk assessments through task 1 resulted in a long-list of attributes. The derived attributes ranged from broad consideration of general characteristics including description of the species through to criteria relevant to the invasion process including likelihood of arrival, establishment and spread. Impacts were classified broadly and included biodiversity and socio-economic impacts alongside perspectives influencing impacts such as climate change. Additional consideration was given to implementation of the protocol including quality assurance and alignment with agreed international standards and policies such as the World Trade Organisation (WTO) and relevant EU Directives including the EU Marine Strategy Framework Directive (MSFD) and EU Water Framework Directive (WFD). From the long-list the core project team developed and selected a draft short-list of attributes that were considered to be relevant for performing risk assessments of IAS. The short-list of minimum standards was agreed by the project team and preliminarily reviewed through a pre-workshop survey in Task 3. Task 3: Risk assessment workshop The overarching aim of the risk assessment workshop (27-28th March 2014) was to peer-review the derived short-list of minimum standards. The derived minimum standards are required to underpin evaluation of existing risk assessments and ensure they are fit for the purpose of supporting the development of a list of “IAS of EU concern”. We aimed to distil the critical components of a risk assessment that, through expert opinion and consensus, are agreed necessary to achieve overarching, robust and rigorous assessment of the risk of an IAS, regardless of the specific approach taken. Additionally consideration was given to recognized international guidelines and recommendations with relevance to the development of minimum standards for risk assessments. The workshop included participants from the project team (23 experts from nine organisations) and 12 additional invited experts. The invited experts and those from within the team represented a breadth of expertise from a variety of perspectives including taxonomic (all taxa, including pathogens), environmental (freshwater, marine and terrestrial), impacts (environmental, socio-economic and health) and disciplines (ecologists, economist, conservation practitioners, scientists, policy-makers, risk assessors). Many of the experts had been actively involved in the development, testing and implementation of risk assessment protocols for IAS. The experts were invited to review and refine the list of attributes derived through Tasks 1 and 2 for inclusion as potential minimum standards. The long list of attributes of risk assessments derived through Task 1 and 2 were circulated in the form of a pre-workshop survey (using Survey Monkey) in which the experts were asked to rank the importance of each as a potential minimum standard on a scale of 1 (low importance) to 5 (high importance). Experts were also asked to provide additional attributes that were not apparent from the long-list. The pre-workshop survey revealed a high level of consensus between all experts for most of the attributes. However one-third of the experts stated that a totally new EU-wide risk assessment system tailored for the new IAS Regulation should be developed. Attributes aligning with socio-economic aspects also appeared to cause division in responses by the experts. Furthermore, questions relating to cost-benefit led to a high degree of uncertainty with more than a third of participants responding “unsure”. The disagreement or uncertainty expressed by respondents on these specific themes highlighted the need to ensure that socio-economic considerations were included as a substantial component of the workshop programme. Clarity is an overarching requirement of risk assessment protocols to ensure consistency. It is of utmost importance that a protocol asks questions that are sufficiently clear and understandable for assessors. This is essential to ensure that responses (accompanied by an indication of level of uncertainty) deliver similar assessments for the same species in the same area, irrespective of the identity of the assessors – as long as these have the necessary expertise or are provided with the necessary information. Fourteen criteria were agreed, through consensus methods, to represent the minimum standards. The minimum standards are: 1. Description (Taxonomy, invasion history, distribution range (native and introduced), geographic scope, socio-economic benefits) 2. Includes the likelihood of entry, establishment, spread and magnitude of impact 3. Includes description of the actual and potential distribution, spread and magnitude of impact 4. Has the capacity to assess multiple pathways of entry and spread in the assessment, both intentional and unintentional 5. Can broadly assess environmental impact with respect to biodiversity and ecosystem patterns and processes 6. Can broadly assess environmental impact with respect to ecosystem services 7. Broadly assesses adverse socio-economic impact 8. Includes status (threatened or protected) of species or habitat under threat 9. Includes possible effects of climate change in the foreseeable future 10. Can be completed even when there is a lack of data or associated information 11. Documents information sources 12. Provides a summary of the different components of the assessment in a consistent and interpretable form and an overall summary 13. Includes uncertainty 14. Includes quality assurance Task 4: Screening of existing risk assessment methodologies None of the analysed risk assessment protocols were fully compliant with the minimum standards. However, there were a number of protocols that appeared to be compliant with a sufficient number of the minimum standards or with the potential to be modified in accordance with the minimum standards to be included within Task 4. The GB NNRA, EPPO DSS, Harmonia+ and ENSARS were the risk assessment protocols that most closely met the minimum standards, they are further referred to as "substantially compliant risk assessments". The risk assessments undertaken with the GB NNRA and EPPO DSS were accessible and included a range of species. Harmonia+ has potential as a risk assessment protocol with broad taxonomic and geographic applicability. It is a comprehensive risk assessment protocol, however it has only recently been published and currently no species have been formally assessed using this method. ENSARS includes assessments for a number of species but these are not yet formally published. GB NNRA and Harmonia+ both currently lack inclusion of description of socio-economic benefits. However, experts representing these methods acknowledge a willingness to include this aspect as a priority in the future. The EPPO DSS and ENSARS already consider such benefits. Consideration of possible effects on climate change in the foreseeable future was lacking in most protocols. However, the GB NNRA does include climate change considerations. ENSARS, Harmonia+ and EPPO fail to include climate change considerations within their protocols but could easily include this aspect as a priority for updates in the future. Consideration of the effects of IAS on ecosystem services was almost consistently lacking in the risk assessment protocols. This was identified through the literature review (Tasks 1 and 2) but was confirmed through Task 4. IAS impacts on biodiversity, ecosystem patterns and processes, ecosystem services and related socio-economic implications are clearly interlinked. Therefore, there are foreseen to be overlaps in how these different impacts are determined in practice: the identification of impacts on biodiversity and ecosystem characteristics clearly forms the basis for impacts on ecosystem services whereas identifying the impacts on ecosystem services form a key conceptual basis for assessing the foreseen socio-economic impacts of IAS invasion. These overlaps – or synergies - should be taken into consideration when developing these three minimum standards further in the future. It is foreseen that a dedicated guidance on how to assess the impact on ecosystem services, in the context of EU risk assessments for IAS, would need to be developed. Task 5: Screening of potential “IAS of EU Concern” and proposal of a list Prioritisation of potential “IAS of EU concern” is essential to both target IAS interventions at the species constituting the highest risks and for allocating the limited resources available for invasion management based on feasibility of outcomes. The establishment of a risk analysis framework, in consultation with the EC, would ensure a coherent and coordinated response to risks of EU relevance which could be termed “IAS of EU concern”. The main objective of the study was to analyse a set of species that have been risk assessed using protocols meeting the minimum standards to develop the list of “IAS of EU concern”. As a result of the analysis in Task 4, it was apparent that none of the existing protocols screened, tested and discussed within Task 3 meet the full set of minimum standards. We proceeded with the analysis of the list of 80 species provided by the Commission against those protocols for risk assessment that were considered as “substantially compliant”. Due to the lack of risk assessment protocols compliant with the minimum standards, it was not possible to obtain a fully compliant list of proposed “IAS of EU concern” as initially foreseen. However, four risk assessment protocols, namely the EPPO DSS, ENSARS, GB NNRA and Harmonia+, were selected as they meet “most” minimum standards and included a breadth of species in existing assessments. The lists generated from the four selected protocols were thus cross-tabulated against the list of 80 species provided by the EC. It is important to note that some of the existing assessments (most notably within GB NNRA, ENSARS and Harmonia+) apply to a restricted area within Europe and so caution in extrapolating outcomes to a European-scale is required. In total 50 species are included within the draft list of proposed “IAS of EU concern” and these were identified through the “substantially compliant” risk assessments as posing a medium to high risk on biodiversity and/or human health and the economy. Of these 37 are from GB NNRA, 18 from EPPO and one from ENSARS. Seven of the species were assessed within more than one protocol. The list includes 14 species in addition to those within the original list provided by the EC. The draft list of proposed “IAS of EU concern” includes 25 plants, 12 vertebrates, 13 invertebrates of which most are found in the terrestrial and freshwater environments (24 and 20 respectively whereas only six marine species are included). The draft list is constrained by inclusion of only the IAS for which a “substantially compliant” risk assessment is available. Furthermore, there are inherent limitations of a list of proposed “IAS of EU concern” compiled on the basis of risk assessment protocols which do not fully comply with the agreed minimum standards. This is reflected in a number of shortcomings or inconsistencies resulting from the outcomes of the four protocols which were used to draft the list of proposed “IAS of EU concern”. Concluding remarks and key recommendations Available risk assessment protocols that meet the minimum standards are an important step in developing a list of “IAS of EU concern”. Refinements to existing risk assessment protocols are required to ensure they include consideration of ecosystem services, climate change and adverse impacts on socio-economic benefits. As these criteria are encompassed it will be necessary to critically test and evaluate the performance of these modified protocols as it is necessary to improve consistency of outcomes. Support should be given to enable developments to modify risk assessment protocols within their mandate to comply with the new EU Regulation. This should include the development of appropriate guidance on the interpretation and use of minimum standards where required. Additionally the importance of national impact assessment protocols should be recognised with consideration given to modifications of methods to provide a scientific basis for EU assessments. These assessments should serve as source to identify potential additional ‘IAS of EU concern’ and evaluation of the list. Impact assessments are not compliant with the minimum standards because of lack of consideration of mechanisms of introduction and establishment. However, impact assessments provide a detailed basis upon which to quantify the impacts of IAS and include aspects that could be considered for inclusion within full risk assessments. The risk assessment methods based on the protocol devised by EPPO DSS, namely GB NNRA and ENSARS, provide a basis on which to begin developing a list of ‘IAS of EU concern’. However, the breadth of species considered relevant is influenced by the original purposes of both protocols. Harmonia+ is a new and promising risk assessment method. It will be essential to consider the relevance of this protocol as one of the key players going forward. A critical issue exists in the simplification of extrapolating national or regional assessments to the total area of the EU. The EU is rich in biodiversity and is a highly heterogeneous and large territory and so risk assessments of IAS may differ substantially when different regions are considered. Consideration of European biogeographic regions as contex for existing national risk assessments protocols would be appropriate. It is essential to ensure that risk assessments undertaken for restricted regions within Europe (such as the GB NNRA, ENSARS and Harmonia+) have relevance to the EU as outlined above. Review of the applicability of such assessments for EU relevance is unlikely to be trivial for many IAS. Re-assessment of risks identified through national risk assessment protocols at the EU level (with consideration of biogeographic regions) through scientific experts should be prioritised. Further development of the list of proposed “IAS of EU concern” is necessary and should involve scientific experts based on the framework provided by the new EU Regulation. It will be essential to develop a process for consolidating the draft list of proposed “IAS of EU concern” through involvement of scientific experts. The list of proposed “IAS of EU concern” will need to be reviewed on a regular basis to ensure it remains current as the number of new arrivals escalates. Equally the knowledge underpinning our understanding of invasions and environmental change will improve and additional relevant concepts will emerge. Therefore, periodically it will be necessary not only to review the list of proposed “IAS of EU concern” but also the framework of minimum standards upon which it is based as, for example, understanding increases and evidence suggests the need to modify minimum standards or indeed include additional minimum standards. Consideration of the establishment of a formal procedure for evaluating the list of proposed “IAS of EU concern” after 2016 should be prioritised. It will be essential to provide support for cooperation between scientific experts (responsible for the risk assessments) and the Member State and stakeholder experts (responsible for the risk management and communication). Indeed before the final list of “IAS of EU concern” is determined risk management factors should be taken into account, such as how widespread the species is within the EU, what benefits are associated with the species and the cost-benefit of adding the species to the list of “IAS of EU concern"

Organogenesis and tumorigenesis: Insight from the JAK/STAT pathway in the Drosophila eye

The Janus kinase (JAK) signal transducer and activator of transcription (STAT) pathway is one of the main signaling pathways in eukaryotic cells. This pathway is used during diverse growth and developmental processes in multiple tissues to control cell proliferation, differentiation, survival, and apoptosis. In addition to its role during development, the JAK/STAT pathway has also been implicated in tumorigenesis. Drosophila melanogaster is a powerful genetic tool, and its eyes have been used extensively as a platform to study signaling pathways. Many reports have demonstrated that the JAK/STAT pathway plays pleiotropic roles in Drosophila eye development. Its functions and activation are decided by its interplay with other signal pathways and the epigenetic status. In this review, we focus on the functions and regulation of the JAK/STAT pathway during eye development and provide some insights into the study of this pathway in tumorigenesis. Developmental Dynamics 239:2522–2533, 2010. © 2010 Wiley-Liss, Inc

Integration of JAK/STAT receptor-ligand trafficking, signalling and gene expression in Drosophila melanogaster cells

The JAK/STAT pathway is an essential signalling cascade required for multiple processes during development and for adult homeostasis. A key question in understanding this pathway is how it is regulated in different cell contexts. Here we have examined how endocytic processing contributes to signalling by the single cytokine receptor, Domeless, in Drosophila melanogaster cells. We identify an evolutionarily conserved di-Leu motif that is required for Domeless internalisation and show that endocytosis is required for activation of a subset of Domeless targets. Our data indicate that endocytosis both qualitatively and quantitatively regulates Domeless signalling. STAT92E, the single STAT transcription factor in Drosophila, appears to be the target of endocytic regulation and our studies show that phosphorylation of STAT92E on Tyr704, while necessary, is not always sufficient for target transcription. Finally, we identify a conserved residue, Thr702, which is essential for Tyr704 phosphorylation. Taken together, our findings identify previously unknown aspects of JAK/STAT pathway regulation likely to play key roles in the spatial and temporal regulation of signalling in vivo

Coralline algae (Rhodophyta) in a changing world: integrating ecological, physiological, and geochemical responses to global change

Coralline algae are globally distributed benthic primary producers that secrete calcium carbonate skeletons. In the context of ocean acidification, they have received much recent attention due to the potential vulnerability of their high-Mg calcite skeletons and their many important ecological roles. Herein, we summarize what is known about coralline algal ecology and physiology, providing context to understand their responses to global climate change. We review the impacts of these changes, including ocean acidification, rising temperatures, and pollution, on coralline algal growth and calcification. We also assess the ongoing use of coralline algae as marine climate proxies via calibration of skeletal morphology and geochemistry to environmental conditions. Finally, we indicate critical gaps in our understanding of coralline algal calcification and physiology and highlight key areas for future research. These include analytical areas that recently have become more accessible, such as resolving phylogenetic relationships at all taxonomic ranks, elucidating the genes regulating algal photosynthesis and calcification, and calibrating skeletal geochemical metrics, as well as research directions that are broadly applicable to global change ecology, such as the importance of community-scale and long-term experiments in stress response

Hadron structure from lattice quantum chromodynamics

This is a review of hadron structure physics from lattice QCD. Throughout this report, we place emphasis on the contribution of lattice results to our understanding of a number of fundamental physics questions related to, e.g., the origin and distribution of the charge, magnetization, momentum and spin of hadrons. Following an introduction to some of the most important hadron structure observables, we summarize the methods and techniques employed for their calculation in lattice QCD. We briefly discuss the status of relevant chiral perturbation theory calculations needed for controlled extrapolations of the lattice results to the physical point. In the main part of this report, we give an overview of lattice calculations on hadron form factors, moments of (generalized) parton distributions, moments of hadron distribution amplitudes, and other important hadron structure observables. Whenever applicable, we compare with results from experiment and phenomenology, taking into account systematic uncertainties in the lattice computations. Finally, we discuss promising results based on new approaches, ideas and techniques, and close with remarks on future perspectives of the field.Comment: 189 pages, to be published in Physics Report

Assembly, organization, and function of the COPII coat

A full mechanistic understanding of how secretory cargo proteins are exported from the endoplasmic reticulum for passage through the early secretory pathway is essential for us to comprehend how cells are organized, maintain compartment identity, as well as how they selectively secrete proteins and other macromolecules to the extracellular space. This process depends on the function of a multi-subunit complex, the COPII coat. Here we describe progress towards a full mechanistic understanding of COPII coat function, including the latest findings in this area. Much of our understanding of how COPII functions and is regulated comes from studies of yeast genetics, biochemical reconstitution and single cell microscopy. New developments arising from clinical cases and model organism biology and genetics enable us to gain far greater insight in to the role of membrane traffic in the context of a whole organism as well as during embryogenesis and development. A significant outcome of such a full understanding is to reveal how the machinery and processes of membrane trafficking through the early secretory pathway fail in disease states