Magnetic and mechanical effects of Mn substitutions in AlFe2B2

The mechanical and magnetic properties of the newly discovered MAB-phase class of materials based upon AlFe2B2 were investigated. The samples were synthesised from stoichiometric amounts of all constituent elements. X-ray diffraction shows that the main phase is orthorhombic with an elongated b-axis, similar to AlFe2B2. The low hardness and visual inspection of the samples after deformation indicate that these compounds are deformed via a delamination process. When substituting iron in AlFe2B2 with manganese, the magnetism in the system goes from being ferro- to antiferromagnetic via a disordered ferrimagnetic phase exhibited by AlFeMnB2. Density functional theory calculations indicate a weakening of the magnetic interactions among the transitions metal ions as iron is substituted by manganese in AlFe2B2. The Mn-Mn exchange interactions in AlMn2 B2 are found to be very small

Livestock abundance predicts vampire bat demography, immune profiles, and bacterial infection risk

Human activities create novel food resources that can alter wildlife–pathogen interactions. If resources amplify or dampen, pathogen transmission probably depends on both host ecology and pathogen biology, but studies that measure responses to provisioning across both scales are rare. We tested these relationships with a 4-year study of 369 common vampire bats across 10 sites in Peru and Belize that differ in the abundance of livestock, an important anthropogenic food source. We quantified innate and adaptive immunity from bats and assessed infection with two common bacteria. We predicted that abundant livestock could reduce starvation and foraging effort, allowing for greater investments in immunity. Bats from high-livestock sites had higher microbicidal activity and proportions of neutrophils but lower immunoglobulin G and proportions of lymphocytes, suggesting more investment in innate relative to adaptive immunity and either greater chronic stress or pathogen exposure. This relationship was most pronounced in reproductive bats, which were also more common in high-livestock sites, suggesting feedbacks between demographic correlates of provisioning and immunity. Infection with both Bartonella and haemoplasmas were correlated with similar immune profiles, and both pathogens tended to be less prevalent in high-livestock sites, although effects were weaker for haemoplasmas. These differing responses to provisioning might therefore reflect distinct transmission processes. Predicting how provisioning alters host–pathogen interactions requires considering how both within-host processes and transmission modes respond to resource shifts

Juvenile and young adult-onset systemic sclerosis share the same organ involvement in adulthood: data from the EUSTAR database

Objective. The aim of the present study was to explore the long-term outcome and clinical characteristics of adult patients with juvenile onset in the EULAR Scleroderma Trials and Research (EUSTAR) cohort and compare them with adult patients with onset between 20 and 40 years of age. Methods. From the EUSTAR SSc cohort two patient groups were analysed: patients with juvenile SSc (jSSc) who are adults at present, and patients diagnosed between the age of 20 and 40 years (aSSc). Demographic data of the patients, organ involvement and outcome of the disease were examined using the Minimal Essential Data Set database system. Results. From 5000 patients in the EUSTAR cohort, 60 patients (1.2%) with jSSc and 910 patients (18%) with aSSc were selected according the inclusion criteria. In the jSSc group, the mean age of disease onset was 12.4 years (range 2-15.9 years), and in the aSSc group, the mean age was 32 years (range 20-40 years). Disease subsets were similar. The antibody profile was also comparable except for ACAs, which were positive in 5% of the jSSc group and 26.9% of the aSSc group (P < 0.005). Organ involvement (lung, kidney, joint, muscle and heart) was similar in the two groups of patients at the time of the last follow-up. Conclusion. The subset distribution in the jSSc and aSSc cohorts was found to be similar. Only the frequency of ACAs was significantly lower in the jSSc, which supports the hypothesis that the SSc patients with paediatric onset in the adult cohort may represent a distinct subgroup of the complete cohort of paediatric patient