Single-sex schools and science engagement

This paper considers whether single-sex schooling affects gendered patterns in the uptake of science courses in year 11 and the development of science-related career paths. In particular, the author is interested in exploring gender differences surrounding the life and physical sciences. The author explores these issues using data from the Longitudinal Surveys of Australian Youth. Differences in the uptake of life and physical science subjects by males and females occur across all schools. In girls-only schools girls are more likely to undertake physical science subjects than their female counterparts in co-educational schools, but there is no difference when it comes to planning a physical science career. On the other hand, boys in boys-only schools are no more likely to take up life science subjects than their male counterparts in co-educational schools, but they are more likely to plan life science careers

Constraining the vertical structure of the Milky Way rotation by microlensing in a finite-width global disk model

In this paper we model the vertical structure of mass distribution of the Milky Way galaxy in the framework of a finite-width global disk model. Assuming the Galactic rotation curve only, we test inside the solar orbit the predictions of the model for two measurable and unrelated to each other processes: the gravitational microlensing that allows to fix the disk width-scale by the best fit to measurements, and the vertical gradient of rotation modelled in the quasi-circular orbits approximation. The former is sensitive to the gravitating mass in compact objects and the latter is sensitive to all kinds of gravitating matter. The analysis points to a small width-scale of the considered disks and, at most, insignificant contribution of non-baryonic dark mater in the solar circle. The predicted high vertical gradient values in the rotation are consistent with the gradient measurements.Comment: 10 pages, 10 figure

Modeling vertical structure in circular velocity of spiral galaxy NGC 4244

We study the vertical gradient in azimuthal velocity of spiral galaxy NGC 4244 in a thin disk model. With surface density accounting for the rotation curve, we model the gradient properties in the approximation of quasi-circular orbits and find the predictions to be consistent with the gradient properties inferred from measurements. This consistency may suggest that the mass distribution in this galaxy is flattened.Comment: 5 pages, 6 figure

Velocity-density twin transforms in thin disk model

Ring mass density and the corresponding circular velocity in thin disk model are known to be integral transforms of one another. But it may be less familiar that the transforms can be reduced to one-fold integrals with identical weight functions. It may be of practical value that the integral for the surface density does not involve the velocity derivative, unlike the equivalent and widely known Toomre's formula.Comment: 3 pages; 1 figure (a separate file); v2: added a derivation of w(x) from an infinitely flattened spheroid; v3 improvement/correction of the derivation in v2 + minor corr. in the tex

The effect of low doses of glyphosate on reactive oxygen species production by human granulocytes

Glyphosate is the base of numerous herbicides used widely all over the world. Strong hepato- and nephrotoxicity of high doses of this reagent was reported in laboratory animal studies. In European Union countries the acceptable daily intake for humans is set at 0.5 mg/kg body weight. We investigated the effects of glyphosate on peripheral blood polymorphonuclear cells (PMNs) at relatively low concentrations of the reagent, from 0.01 mg/L to 10 mg/L (from ~0.06 μM to 59 μM). As the biological half-life of this compound in the human body is estimated to be 3 to 10 hours, we decided to incubate blood samples with glyphosate for a period of one hour. Such incubation caused a statistically significant increase of reactive oxygen species production in granulocytes stimulated with N-formylmethionine-leucyl-phenylalanine and Escherichia coli cells. This increase was not associated with the toxic effects of glyphosate or with increased phagocytic activity of granulocytes. The reagent, when applied at specified concentrations, did not induce a respiratory burst in granulocytes or affect the amount of production of reactive oxygen species in blood samples stimulated with 12-myristate phorbol 13-acetate. On the basis of the results obtained, it may be suggested that glyphosate affects signaling pathways leading to NADPH oxidase activation, independent of protein kinase C activation. Thus, it can be concluded that although low doses of glyphosate are not harmful to humans, synergistic effects of this compound with other environmental pollutants may be an important part of pathogenic mechanisms. DOI: http://dx.doi.org/10.5281/zenodo.842857

Adolescent occupational expectations: two decades of LSAY-based research

The fifth section of this publication contains four chapters that have a particular focus on employment and other labour market outcomes. The first chapter, Adolescent occupational expectations, is written by Dr Joanna Sikora. It draws on several studies, published between 2011 and 2018, that have used LSAY data to investigate the influences of educational plans, occupational plans, gender, and socioeconomic background on later outcomes. The main findings were: � 56% of boys and 66% of girls planned to become professionals at age 15 years, both of which are significantly higher than the actual proportions observed in the adult population � More than one quarter of participants had failed to achieve their occupational expectations at age 15 years by the time they were 25 years old, with similar proportions failing to realise their expectation of completing university � Students from lower socioeconomic backgrounds were more likely to downwardly adjust their educational and occupational expectations over time � Occupational uncertainty at age 15 increased the likelihood of occupational uncertainty at age 22 by 45% � The gender gap in expectations of STEM careers remained relatively stable between 1999 and 2015, with computing, engineering, and mathematics appealing to relatively few young women � Females were less likely than males to retain career plans concerning computing and engineering (19% vs. 32%)

Impact of antibiotics on the proliferation and differentiation of human adipose-derived mesenchymal stem cells

Adipose tissue is a promising source of mesenchymal stem cells. Their potential to differentiate and regenerate other types of tissues may be affected by several factors. This may be due to in vitro cell-culture conditions, especially the supplementation with antibiotics. The aim of our study was to evaluate the effects of a penicillin-streptomycin mixture (PS), amphotericin B (AmB), a complex of AmB with copper (II) ions (AmB-Cu2+) and various combinations of these antibiotics on the proliferation and differentiation of adipose-derived stem cells in vitro. Normal human adipose-derived stem cells (ADSC, Lonza) were routinely maintained in a Dulbecco’s Modified Eagle Medium (DMEM) that was either supplemented with selected antibiotics or without antibiotics. The ADSC that were used for the experiment were at the second passage. The effect of antibiotics on proliferation was analyzed using the 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide (MTT) and sulforhodamine-B (SRB) tests. Differentiation was evaluated based on Alizarin Red staining, Oil Red O staining and determination of the expression of ADSC, osteoblast and adipocyte markers by real-time RT-qPCR. The obtained results indicate that the influence of antibiotics on adipose-derived stem cells depends on the duration of exposure and on the combination of applied compounds. We show that antibiotics alter the proliferation of cells and also promote natural osteogenesis, and adipogenesis, and that this effect is also noticeable in stimulated osteogenesis