Stellar (n,γ) cross sections of ²³Na

The cross section of the ²³Na(n,γ)²⁴Na reaction has been measured via the activation method at the Karlsruhe 3.7 MV Van de Graaff accelerator. NaCl samples were exposed to quasistellar neutron spectra at kT = 5.1 and 25 keV produced via the ¹⁸O(p,n)¹⁸F and ⁷Li(p,n)⁷Be reactions, respectively. The derived capture cross sections (σ)kT=5keV = 9.1 ± 0.3mb and (σ)kT=25keV = 2.03 ± 0.05 mb are significantly lower than reported in literature. These results were used to substantially revise the radiative width of the first ²³Na resonance and to establish an improved set of Maxwellian average cross sections. The implications of the lower capture cross section for current models of s-process nucleosynthesis are discussed

Legume tasters: symbiotic rhizobia host preference and smart inoculant formulations

Mutualistic interactions have great importance in ecology, with genetic infor-mation that takes shape through interactions within the symbiotic partners and between the partners and the environment. It is known that variation of the host-associated microbiome contributes to buffer adaptation challenges of the host’s physiology when facing varying environmental conditions. In agriculture, pivotal examples are symbiotic nitrogen-fixing rhizobia, known to contribute greatly to host (legume plants) adaptation and host productivity. A holistic view of increasing crop yield and resistance to biotic and abiotic stresses is that of microbiome engineering, the exploitation of a host-associated microbiome through its rationally designed manipulation with synthetic microbial commu-nities. However, several studies highlighted that the expression of the desired phenotype in the host resides in species-specific, even genotype-specific in-teractions between the symbiotic partners. Consequently, there is a need to dissect such an intimate level of interaction, aiming to identify the main ge-netic components in both partners playing a role in symbiotic differences/host preferences. In the present paper, while briefly reviewing the knowledge and the challenges in plant–microbe interaction and rhizobial studies, we aim to promote research on genotype x genotype interaction between rhizobia and host plants for a rational design of synthetic symbiotic nitrogen-fixing microbial communities to be used for sustainably improving leguminous plants yield

Stellar neutron capture cross sections of ²⁰ ²¹ ²²Ne

The stellar (n,γ) cross sections of the Ne isotopes are important for a number of astrophysical quests, i.e., for the interpretation of abundance patterns in presolar material or with respect to the s-process neutron balance in red giant stars. This paper presents resonance studies of experimental data in the keV range, which had not been fully analyzed before. The analyses were carried out with the R-matrix code sammy. With these results for the resonant part and by adding the components due to direct radiative capture, improved Maxwellian-averaged cross sections (MACS) could be determined. At kT=30keV thermal energy we obtain MACS values of 240±29,1263±160, and 53.2±2.7 μbarn for ²⁰Ne,²¹Ne, and ²²Ne, respectively. In earlier work the stellar rates of ²⁰Ne and ²¹Ne had been grossly overestimated. ²²Ne and ²⁰Ne are significant neutron poisons for the s process in stars because their very small MACS values are compensated by their large abundances

Co-design of immersive virtual learning environments. A pilot study involving people with intellectual disability and SLDs

This paper describes a pilot study conducted at the University of Macerata, within the project Inclusion 3.0. It aims to explore the possibility of using high-fidelity prototyping in a virtual laboratory to support the co-creation of an immersive virtual learning environment with people with disability and Specific Learning Disorders (SLDs), from the earliest design stages. The paper presents the results of the co-design process and discusses its implications in defining design requirements to ensure the accessibility of immersive solutions for cultural heritage

Robust Online Magnet Demagnetization Diagnosis in Asymmetrical Six-Phase AC Permanent Magnet Motor Drives

Rotor magnets are critical components, which in case of fault, directly affect the performance of drives based on permanent magnet synchronous motors. Thus, monitoring the rotor magnets status is essential to ensure both high level of efficiency and service continuity. The present study focuses on the investigation of a new full-time domain-based method for the diagnosis of incipient rotor magnet demagnetization in a vector-controlled asymmetrical six-phase surface-mounted ac permanent magnet synchronous motor. The proposed strategy evaluates the rotor magnet demagnetization using a fault index derived from the control signals synthetized in the 5th subspace, and already available in the control system platform. The main advantages of the proposed new strategy are its simplicity of implementation, and effectiveness even under time-varying operating conditions as the employed control signals in specific subspaces have a dc behavior. Extensive numerical simulations and experimental tests, carried out at different speed and load levels, have shown the validity of the proposed method, leading to an effective diagnostic procedure for a vector-controlled asymmetrical six-phase surface-mounted ac PMSM

Fine-scale spatial genetic structure and dispersal among Italian smooth newt populations in a rural landscape

Amphibians are particularly sensitive to habitat loss and fragmentation caused by the intensification and modernization of farming occurring in the second half of the twentieth century in the Mediterranean basin. However, artificial water bodies, associated with traditional husbandry, proved to be important surrogate for amphibian feeding and reproduction. Here, multilocus genotypes were used to investigate the spatial population structure of Lissotriton vulgaris meridionalis and the role of drinking troughs in supporting viable breeding populations within a rural landscape interested by traditional husbandry and agriculture. Our genetic analysis highlighted the conservation value and the potential stepping-stone function of artificial aquatic sites in the dispersal of the species and for the gene flow maintenance. Indeed, populations of drinking troughs show allelic richness and heterozygosity levels comparable to those from natural ponds and there is no great evidence of genetic bottlenecks. A complex system of artificial aquatic sites and few natural wetlands was identified sustaining a well-structured network of demes highly interconnected with themselves and natural aquatic sites. The conservation of the identified genetic clusters may be useful to prevent further population declines and future loss of genetic diversity within the study area characterized by scarce natural wetlands that frequently dried because of agricultural practices and strong seasonality. Site-specific protection measures are needed to contrast the progressive disappearance of drinking troughs observed in the last years in Italy because of the abandonment of traditional farming practices in favour of modern agriculture and intensive farming

Do not disturb the family: roles of colony size and human disturbance in the genetic structure of lesser kestrel

Dispersal and philopatry are fundamental processes influencing the genetic structure and persistence of populations and might be affected by isolation and habitat perturbation. Habitat degradation induced by human activities could have detrimental consequences on genetic structure of populations. Therefore, it is crucial to understand the role of human impacts in promoting or disrupting genetic structure. Here, we conducted a genetic analysis using 12 polymorphic microsatellite markers of 70 lesser kestrels (Falco naumanni) from 10 breeding colonies of two subpopulations in Sicily (southern Italy). Genetic differentiation between the two subpopulations was negligible, and linear distances played no role in the level of genetic relatedness recorded in the two sites. Linear distances between nests also resulted in no effects on the relatedness recorded within and between colonies in the largest subpopulation. Clusters of more versus less related individuals resulted when the two-dimensional positions of colonies (i.e., latitude and longitude) were tested as predictors of genetic proximity instead of linear distances. Specifically, analyses of colony features showed colony size and human disturbance as factors negatively affecting the relatedness among chicks from different nests. Regardless of colony size, less-related individuals were born in colonies located in the core of the agricultural plain, where we quantified a higher level of human disturbance. In contrast, more related individuals were in colonies that existed in the marginal, less disturbed, agricultural area. Given the high philopatry of this species, our results are consistent with disruption of colony fidelity related to intensification of agricultural practices. We discuss the possible implications of long-term effects of genetic variability in small and disturbed colonies on fitness and population viability

Defective production of interferon-γ and tumour necrosis factor-α by AIDS mononuclear cells after in vitro exposure to Rhodococcus equi

The production of interferon-γ and tumour necrosis factor-α was evaluated in the peripheral blood mononuclear cells (PBMCs) from healthy donors and AIDS patients after Rhodococcus equi infection in vitro. PBMCs from healthy donors secreted elevated levels of IFN-γ and TNF-α when challenged in vitro with killed R. equi, whereas the release of both cytokines was impaired in supernatant cultures from AIDS patients. We conclude that the failure of IFN-γ generation in AIDS patients in response to R. equi is not antigen-specific but it may reflect the global impairment of T-cell function. In such patients, however, the infection with R. equi, a facultative intracellular pathogen which survives and replicates within macrophages, may be responsible for the impairment in the TNF-α release, possibly enhancing the HIV-induced macrophage dysftmction