Focal mechanisms in the southern Aegean from temporary seismic networks – implications for the regional stress field and ongoing deformation processes

The lateral variation of the stress field in the southern Aegean plate and the subducting Hellenic slab is determined from recordings of seismicity obtained with the CYCNET and EGELADOS networks in the years from 2002 to 2007. First motions from 7000 well-located microearthquakes were analysed to produce 540 well-constrained focal mechanisms. They were complemented by another 140 derived by waveform matching of records from larger events. Most of these earthquakes fall into 16 distinct spatial clusters distributed over the southern Aegean region. For each cluster, a stress inversion could be carried out yielding consistent estimates of the stress field and its spatial variation. At crustal levels, the stress field is generally dominated by a steeply dipping compressional principal stress direction except in places where coupling of the subducting slab and overlying plate come into play. Tensional principal stresses are generally subhorizontal. Just behind the forearc, the crust is under arc-parallel tension whereas in the volcanic areas around Kos, Columbo and Astypalea tensional and intermediate stresses are nearly degenerate. Further west and north, in the Santorini–Amorgos graben and in the area of the islands of Mykonos, Andros and Tinos, tensional stresses are significant and point around the NW–SE direction. Very similar stress fields are observed in western Turkey with the tensional axis rotated to NNE–SSW. Intermediate-depth earthquakes below 100 km in the Nisyros region indicate that the Hellenic slab experiences slab-parallel tension at these depths. The direction of tension is close to east–west and thus deviates from the local NW-oriented slab dip presumably owing to the segmentation of the slab. Beneath the Cretan sea, at shallower levels, the slab is under NW–SE compression. Tensional principal stresses in the crust exhibit very good alignment with extensional strain rate principal axes derived from GPS velocities except in volcanic areas, where both appear to be unrelated, and in the forearc where compressional principal stresses are very well aligned with compressional principal strain rates. This finding indicates that, except for volcanic areas, microseismic activity in the southern Aegean is not controlled by small-scale local stresses but rather reflects the regional stress field. The lateral and depth variations of the stress field reflect the various agents that influence tectonics in the Aegean: subduction of the Hellenic slab, incipient collision with continental African lithosphere, roll back of the slab in the southeast, segmentation of the slab, arc volcanism and extension of the Aegean crust

Social Portrait of the Family in the Light of New Socio-Political Trends

The issue regarding formation of a values-based attitude towards creating a family among modern youth is acquiring special relevance, since changes in moral guidelines have led to the intensification of negative phenomena such as: liberalisation of sexual morality, an increased number of divorces, illegitimate births, single-parent families, and the spread of social orphanhood. Due to the fact that the family is currently perceived as a structural component of the development of individual socio-economic trends, the purpose of the paper is to assess the levels of values-based attitudes towards family creation among students. In the course of the study, the following methods were used: diagnostic (questionnaires, the method of sentence completion, testing), that made it possible to identify the levels of formation of the attitude towards family creation among students; a theoretical method of analysis that allows a comprehensive study of the reasons that complicate the process of forming a values-based attitude regarding family creation. The novelty of the study is determined by the fact that a student family is understood as a family in which both spouses are full-time students of a higher education institution, that is, homogeneous in social status of a man and a woman. This is a young family in which the spouses are no more than 28 years old, and the length of family life does not exceed 5 years. The paper indicates that student families are the most progressive, since spouses are ready to accept everything new - in the organisation of life, in the arrangement of the family structure, and the like. Material motives in choosing a spouse in such families play a secondary role, especially in relation to the requirements from a woman to a man. The materials of the paper are of practical value for experimental verification of pedagogical conditions for the family creation among students in extracurricular activities

Clubroot resistance gene Rcr6 in Brassica nigra resides in a genomic region homologous to chromosome A08 in B. rapa

Background: Clubroot, caused by Plasmodiophora brassicae Woronin, is a very important disease of Brassica species. Management of clubroot relies heavily on genetic resistance. In a cross of Brassica nigra lines PI 219576 (highly resistant, R) × CR2748 (highly susceptible, S) to clubroot, all F1 plants were resistant to clubroot. There was a 1:1 ratio of R:S in the BC1 and 3R:1S in the F2, which indicated that a single dominant gene controlled clubroot resistance in PI 219576. This gene was designated Rcr6. Mapping of Rcr6 was performed using genome sequencing information from A-genome of B. rapa and B-genome of B. nigra though bulked segregant RNA sequencing (BSR-Seq) and further mapping with Kompetitive Allele Specific PCR (KASP) analysis. Results: Reads of R and S bulks from BSR-Seq were initially aligned onto B. rapa (A-genome; B. nigra has the B-genome) where Rcr6 was associated with chromosome A08. KASP analysis showed that Rcr6 was flanked by SNP markers homologous to the region of 14.8-15.4 Mb of chromosome A08. There were 190 genes annotated in this region, with five genes (Bra010552, Bra010588, Bra010589, Bra010590 and Bra010663) identified as encoding the toll-interleukin-1 receptor / nucleotide-binding site / leucine-rich-repeat (TIR-NBS-LRR; TNL) class of proteins. The reads from BSR-Seq were then aligned into a draft B-genome of B. nigra, where Rcr6 was mapped on chromosome B3. KASP analysis indicated that Rcr6 was located on chromosome B3 in a 0.5 Mb region from 6.1-6.6 Mb. Only one TNL gene homologous to the B. rapa gene Bra010663 was identified in the target region. This gene is a likely candidate for Rcr6. Subsequent analysis of the Rcr6 equivalent region based on a published B. nigra genome was performed. This gene is located into chromosome B7 of the published B-genome, homologous to BniB015819. Conclusion: Rcr6 was the first gene identified and mapped in the B-genome of Brassica species. It resides in a genomic region homologous to chromosome A08 of A-genome. Based on this finding, it could possibly integrate into A08 of B. napus using marker assisted selection with SNP markers tightly linked to Rcr6 developed in this study

Etude expérimentale d'un arc impulsionnel entre des contacts Ag et Ag-C

International audienc

Variations in rumen microbiota and host genome impacted feed efficiency in goat breeds

IntroductionImproving feed efficiency (FE) is a significant goal in animal breeding programs. Variations in FE and its relationship with rumen microbiota remain poorly understood across different goat breeds.MethodsThis study assessed the influence of the rumen microbiome and host genome on FE in 10 Shami (SH) goats and 10 Zaraibi (ZA) goats, all of which were fed the same diet. The animals were genotyped using the Illumina 65KSNP chip arrays v2, and their rumen bacteria and archaea were investigated using PCR-amplicon sequencing of the 16S rRNA gene.ResultsThe results showed that the ZA goats exhibited higher FE than the SH goats (p < 0.05) and a greater relative abundance (p < 0.05) of rumen bacterial groups that are involved in the degradation of cellulose and hemicelluloses, such as Bacteroidota and Fibrobacterota, along with genera such as Prevotella, Lachnospiraceae AC2044 group, Lachnospiraceae NK3A20 group, and Succiniclasticum, which are linked to carbohydrate and nitrogen metabolism pathways. In addition, breed differences were found to affect the proportions of milk fatty acids. The association analysis identified 26 genome windows containing several putative candidate genes, such as TMEM241, AP4S1, FTO, HYAL2, BBS2, CD52, CRYBG2, PIGV, WDTC1, EEF1A2, GBA2, FNIP1, ACSL6, STARD10, VPS26B, ACAD8, GLB1L3, NRN1L, LCAT, and SLC7A6. These genes contributed to FE traits in Egyptian goats, as they are involved in obesity, metabolism, and the transport of energy, vitamins, fatty acids, proteins, and lipids through diverse biological pathways.DiscussionThis study suggests that specific genetic markers and rumen microbial traits could be used to identify high-efficient individuals in Egyptian goat breeds, and improving breeding strategies for FE