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Fermi-LAT observations provide continuous and regularly-sampled measurements of gamma-ray photon flux for hundreds of blazars. Many of these light curves, spanning almost 15 years, have been thoroughly examined for periodicity in multiple studies. However, the possibility that blazars may exhibit irregularly repeating flaring patterns in their gamma-ray light curves has not been systematically explored. In this study, we aim to find repeating episodes of flaring activity in the 100 brightest blazars using Fermi-LAT light curves with various integration times. We use a Bayesian Blocks representation to convert the time series into strings of symbols and search for repeating sub-strings using a fuzzy search algorithm. As a result, we identify 27 repeated episodes in the gamma-ray light curves of 10 blazars. We find that the patterns are most likely produced in structured jets composed of a fast spine and a slower sheath. When individual emission features propagate in the spine, they scatter seed photons produced in the non-uniform sheath through the inverse Compton mechanism, resulting in a set of gamma-ray flares with a similar profile every such passage. Additionally, we explore the theoretically-predicted possibility that the spine-sheath structure facilitates the production of high-energy neutrinos in blazar jets. Using the catalogue of track-like events detected by the IceCube neutrino telescope, we find evidence supporting this hypothesis at a $3.5\sigma$ significance level., Comment: Submitted

The human gut microbiome produces a functional complex of biomolecules, including nucleic acids, (poly) peptides, structural molecules, and metabolites. This impacts human physiology in multiple ways, especially by triggering inflammatory pathways in disease. At present, much remains to be learned about the identity of key effectors and their causal roles.

The United Nations (UN) is a multilateral organization that addresses issues that transcend national boundaries. The UN Membership approved in 2015 “The 2030 Agenda for Sustainable Development”, which is built on 17 Sustainable Development Goals (SDGs) that serve as the guidelines to all countries - developed and developing - in a global partnership towards achieving a better world (UN, 2022). The UN Development Program (UNDP) is one of the 15 UN agencies that focus on international development to achieve the SDGs. The thesis studies factors determining UNDP SDG 16 (Peace, Justice and Strong Institutions) aid allocations for projects in countries with armed conflict or political instability (UNDP, 2019b). The topic’s relevance lies in the UNDP`s mission statement: “to eradicate poverty and reduce inequality. We help countries to develop policies, leadership skills, partnering abilities, institutional capabilities, and to build resilience to achieve the Sustainable Development Goals.” Thus, the multilateral organization’s transparency and criteria affecting the decision-making process behind the allocation of project funds is an important topic to research. The objective is to determine the factors that affect aid allocations under SDG 16 related to projects in countries with armed conflict or political instability during 2016-20. The research targets aid allocations for projects for peaceful resolution in countries with armed conflict or political instability as a dependent variable relying on the indicators of the recipient country`s requirements based on GDP per capita, number of victims during the years of conflict, and democracy indexes, etc. A panel data set of 150 observations covering 2016-2020 on 30 recipient countries and ten donor countries was collected to build an econometric model (fixed-effects and random-effects models), together with partial qualitative analysis on the data-generating stage to define the factors affecting the UNDP project aid allocations to recipient countries under SDG 16. The key findings of the thesis suggest, as expected, that there is insufficient understanding of the decision-making process in the UNDP allocation system. According to findings, the poorer countries with the larger territory and smaller populations tend to be chosen to receive aid for SDG 16 projects from the UNDP. The results suggest that conflict-specific variables, such as civilian casualties and the size of the country affected by conflict or political instability are considered during the aid allocation decision-making process, which was to be expected based on the specifics of the projects analyzed. Moreover, there is evidence, through both qualitative and quantitative methods to suggest that US interest levels in the country in conflict (e.g., Afghanistan) have a major influence on aid allocation within UNDP SDG 16 projects. Nevertheless, there is no evidence in the data that suggest there is an influence of the amount of monetary contribution by the top 10 donor countries on the aid allocation process for SDG 16 projects. M-ECON

Although the complex interactions between hosts and microbial associates are increasingly well documented, we still know little about how and why hosts shape microbial communities in nature. We characterized the leaf microbiota within 200 clonal accessions in eight field experiments and detected effects of both local environment and host genotype on community structure. Within environments, hosts’ genetics preferentially associate with a core of ubiquitous microbial hubs that, in turn, structure the community. These microbial hubs correlate with host performance, and a GWAS revealed strong candidate genes for the host factors impacting heritable hubs. Our results reveal how selection may act to enhance fitness through microbial associations and bolster the possibility of enhancing crop performance through these host factors. Text Hosts harbor complex microbial communities that are thought to impact health and development 1 . This is best studied in human hosts for which the microbiota has been implicated in a variety of diseases including obesity and cancer 2 . Efforts are thus underway to determine the host factors shaping these resident populations 3,4 and to use next-generation probiotics to inhibit colonization by pathogens 5 . Similarly, in agriculture, there is great hope of shaping the composition of the microbiota in order to mitigate disease and increase crop yield in a sustainable fashion. Indeed, the Food and Agriculture Organization of the United Nations has made the use of biological control and growth promoting microbial associations a clear priority for improving food production 6 . Plant associated microbes can be beneficial in many ways including improving access to nutrients, activating or priming the immune system, and competing with pathogens. For example, seeds inoculated with a combination of naturally occurring microbes were recently found to be protected from a sudden-wilt disease that emerged after continuous cropping 7 . Thus, it would be advantageous to breed crops that promote the growth of beneficial microbes under a variety of field conditions, a prospect that is made more likely by the demonstration of host genotypic effects on their microbiota 8–10 . That said, microbial communities are complex entities that are influenced by the combined impact of host factors, environment and microbe-microbe interactions 11 . As a consequence, the extent to which host plants can control microbial communities to their advantage, especially in a natural context, is unclear. Here, we combine large scale field experiments of plant genotypes grown in their natural environments, extensive microbial community analysis, and genome-wide association mapping to (i) disentangle how the influence of the host is distributed among microbial community members, and thus how host variation shapes the microbiota, (ii) propose plant genes and functions that correlate with variation in the microbiota across environmental conditions, and (iii) examine how key microbial associates impact plant fitness. Our motivation is to further the goal of generating plants with an enhanced ability to host beneficial microbial communities.

Reciprocal crosses between species often display an asymmetry in the fitness of F1 hybrids. This pattern, referred to as isolation asymmetry or Darwin's corollary to Haldane's rule, is a general feature of reproductive isolation in plants, yet factors determining its magnitude and direction remain unclear. We evaluated reciprocal species crosses between two naturally hybridizing diploid species of Arabidopsis to assess the degree of isolation asymmetry at different postmating life stages. We found that pollen from Arabidopsis arenosa will usually fertilize ovules from Arabidopsis lyrata; the reverse receptivity being less complete. Maternal A. lyrata parents set more F1 hybrid seed, but germinate at lower frequency, reversing the asymmetry. As predicted by theory, A. lyrata (the maternal parent with lower seed viability in crosses) exhibited accelerated chloroplast evolution, indicating that cytonuclear incompatibilities may play a role in reproductive isolation. However, this direction of asymmetrical reproductive isolation is not replicated in natural suture zones, where delayed hybrid breakdown of fertility at later developmental stages, or later‐acting selection against A. arenosa maternal hybrids (unrelated to hybrid fertility, e.g., substrate adaptation) may be responsible for an excess of A. lyrata maternal hybrids. Exogenous selection rather than cytonuclear incompatibilities thus shapes the asymmetrical postmating isolation in nature., Ecology and Evolution, 5 (8), ISSN:2045-7758