Observation of Collider Muon Neutrinos with the SND@LHC Experiment

We report the direct observation of muon neutrino interactions with the SND@LHC detector at the Large Hadron Collider. A dataset of proton-proton collisions at √ s = 13.6 TeV collected by SND@LHC in 2022 is used, corresponding to an integrated luminosity of 36.8 fb − 1 . The search is based on information from the active electronic components of the SND@LHC detector, which covers the pseudorapidity region of 7.2 < η < 8.4 , inaccessible to the other experiments at the collider. Muon neutrino candidates are identified through their charged-current interaction topology, with a track propagating through the entire length of the muon detector. After selection cuts, 8 ν μ interaction candidate events remain with an estimated background of 0.086 events, yielding a significance of about 7 standard deviations for the observed ν μ signal

GENETIC STRUCTURE AND PHENOTYPIC VARIATION IN WILD POPULATIONS OF THE MEDICINAL TETRAPLOID SPECIES BROMELIA ANTIACANTHA (BROMELIACEAE)

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Premise of the study : The patterns of genetic structure in plant populations are mainly related to the species life history and breeding system, and knowledge of these patterns is necessary for the management, use, and conservation of biological diversity. Polyploidy is considered an important mode of evolution in plants, but few studies have evaluated genetic structure of polyploid populations. We studied the patterns of genetic structure and morphological variation of Bromelia antiacantha (Bromeliaceae) populations, a polyploid terrestrial species. Methods : Microsatellite markers and morphological analyses were used to explore patterns of genetic and morphological diversity in wild populations of B. antiacantha. Key results : The results of our simple-sequence repeat analyses supported that B. antiacantha is a polyploid species. The inbreeding coefficients were high and significant in all populations (F(IS) = 0.431), indicating homozygote excess. Bromelia antiacantha showed high levels of genetic differentiation among populations (F(ST) = 0.224) and therefore was highly structured. High morphological variation was observed in fruit phenotypic traits in the populations studied. Conclusions : The levels of genetic diversity and the pattern of the population's structure may be related to the low recruitment of seeds, clonal reproduction, and the population's colonization history. The genetic and morphological variability displayed in this study are important issues in planning the conservation and exploitation of this resource in a sustainable way.98915111519Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)PPGBM (Programa de Pos Graduacao em Genetica e Biologia Molecular-UFRGS)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq

Isolation and characterization of microsatellite loci in Pitcairnia albiflos (Bromeliaceae), an endemic bromeliad from the Atlantic Rainforest, and cross-amplification in other species

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Eight microsatellite markers were isolated from Pitcairnia albiflos, an endangered endemic bromeliad species restricted to 'inselberg' rock outcrops in the state of Rio de Janeiro, Brazil. The number of alleles observed for each locus ranged from two to 12. Average observed and expected heterozygosities were 0.408 and 0.663, respectively. The cross-amplification test in 16 taxa suggests that the markers will be useful in numerous related bromeliad species. The loci will be used to study genetic structure and reproductive biology in fragmented inselberg populations and the origin and maintenance of barriers to gene flow between sympatric Pitcairnia species.85980982Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Andrew W. Mellon FoundationConselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES

Biodiversity of zooplankton communities in the Upper Paraná River floodplain: interannual variation from long-term studies

We investigated the effect of interannual variation of hydrosedimentological regime and connectivity on the zooplankton biodiversity in the Upper Paraná River floodplain. Zooplankton samplings were undertaken between 2000 and 2007, in different environments of the floodplain, including connected and isolated floodplain lakes, backwaters, rivers and channels. The zooplankton included 541 species. Rotifers showed the highest species richness and abundance. Among the zooplankton species, 71 represent new occurrence records for the floodplain. The species accumulation curve showed a continuous increase in gamma diversity, demonstrating the importance of long-term research for accurate knowledge of biodiversity in heterogeneous and dynamic ecosystems, such as the floodplains. Interannual beta diversity among studied years indicated a lesser alteration in community composition in 2001, when a long limnophase period was observed. In most of the environments, the highest species richness values were related to the greatest flooding amplitudes. Flooding amplitude, which is associated with connectivity, favors faunal exchange amongst the environments and between the pelagic and littoral zones. This explains the occurrence of both planktonic and non-planktonic species within the community. On the other hand, mean zooplankton abundance values were higher when a long isolation period occurred. Differences between the potamophase and limnophase amplitude associated with connectivity among the environments were the most important factors for the structure and dynamics of the zooplankton community in the Upper Paraná River floodplain

A numerical approach to modelling size effects on the flexural ductility of RC beams

The problem of evaluating the rotation capacity of reinforced concrete (RC) beams in bending has been largely investigated from both the experimental and the analytical point of view during the last decades. Since the development of ductility is influenced by several design parameters, it is difficult to develop a predictive model that can fully describe the mechanical behaviour of RC beams. In particular, the role of the size-scale effect, which has been evidenced by some experimental tests, is not yet completely understood. One of the main reasons is the inadequacy of the traditional models based on ad hoc stress-strain constitutive laws. In the present paper, a new model based on the concept of strain localization is proposed, which is able to describe both cracking and crushing growths in RC beams during the loading process. In particular, the nonlinear behaviour of concrete in compression is modelled by the Overlapping Crack Model, which describes the strain localization due to crushing by means of a material interpenetration. With this algorithm in hand, it is possible to effectively capture the flexural behaviour of RC beams by varying the reinforcement percentage and/or the beam depth. An extensive comparison with experimental results demonstrates the effectiveness of the proposed approac