Experimental campylobacter jejuni infection of scid mice

Campylobacter jejuni was inoculated orally to C.B-17 scid/scid (severe combined immunodeficient) and C.B—17 immunocompetent mice. Groups of mice from each strain were pretreated with enrofloxacin in an attempt to increase colonisation. All mice were heavily colonised but neither clinical signs of illness nor histological lesions were observed. Results from our experiment indicate that specific humoral and cellular immunity are not directly involved in the protection against C. jejuni, since said mice were not more sensitive to the infection than C.B-17 rnice. Animals, treated as well as untreated with antibiotic, showed the same colonisation pattern which suggests that normal flora does not hamper establishing of this bacterium in the intestine. On the other hand this study shows that both C.B~l7 and scid mice may become inapparent carriers of C. jejuni

The spectral dimension of random brushes

We consider a class of random graphs, called random brushes, which are constructed by adding linear graphs of random lengths to the vertices of Z^d viewed as a graph. We prove that for d=2 all random brushes have spectral dimension d_s=2. For d=3 we have {5\over 2}\leq d_s\leq 3 and for d\geq 4 we have 3\leq d_s\leq d.Comment: 15 pages, 1 figur

Structure and magnetic properties of the cubic oxide fluoride BaFeO2F

Fluorination of the parent oxide, BaFeO3- δ, with polyvinylidine fluoride gives rise to a cubic compound with a = 4.0603(4) Å at 298K. 57Fe Mössbauer spectra confirmed that all the iron is present as Fe3+. Neutron diffraction data showed complete occupancy of the anion sites indicating a composition BaFeO2F, with a large displacement of the iron off-site. The magnetic ordering temperature was determined as TN = 645±5K. Neutron diffraction data at 4.2K established G-type antiferromagnetism with a magnetic moment per Fe3+ ion of 3.95μB. However, magnetisation measurements indicated the presence of a weak ferromagnetic moment which is assigned to the canting of the antiferromagnetic structure. 57Fe Mössbauer spectra in the temperature range 10 to 300K were fitted with a model of fluoride ion distribution that retains charge neutrality of the perovskite unit cel

Bringing Nordic mathematics education into the future : a review of the papers presented at the NORMA20 conference

The NORMA conferences held triennially gather academics from the Nordic area and beyond. The conferences offer a window into the key topics and outcomes of Nordic mathematics education research. This paper presents an analysis of the 73 regular papers presented at the NORMA20 conference held in Oslo in June 2021 and published in the conference pre- and proceedings. The analysis yields research questions, methods, and key findings for the educational levels spanning kindergarten through to higher education. The majority of the papers present research from primary school-level and pre- and in-service teacher education. Across the educational levels, teaching methods and classroom discourse emerged as the most frequent topics, dominated by empirical studies that applied qualitative methods.publishedVersio

A population-based study of stimulant drug treatment of ADHD and academic progress in children.

To access publisher's full text version of this article. Please click on the hyperlink in Additional Links field.We evaluated the hypothesis that later start of stimulant treatment of attention-deficit/hyperactivity disorder adversely affects academic progress in mathematics and language arts among 9- to 12-year-old children. We linked nationwide data from the Icelandic Medicines Registry and the Database of National Scholastic Examinations. The study population comprised 11,872 children born in 1994-1996 who took standardized tests in both fourth and seventh grade. We estimated the probability of academic decline (drop of ≥ 5.0 percentile points) according to drug exposure and timing of treatment start between examinations. To limit confounding by indication, we concentrated on children who started treatment either early or later, but at some point between fourth-grade and seventh-grade standardized tests. In contrast with nonmedicated children, children starting stimulant treatment between their fourth- and seventh-grade tests were more likely to decline in test performance. The crude probability of academic decline was 72.9% in mathematics and 42.9% in language arts for children with a treatment start 25 to 36 months after the fourth-grade test. Compared with those starting treatment earlier (≤ 12 months after tests), the multivariable adjusted risk ratio (RR) for decline was 1.7 (95% confidence interval [CI]: 1.2-2.4) in mathematics and 1.1 (95% CI: 0.7-1.8) in language arts. The adjusted RR of mathematics decline with later treatment was higher among girls (RR, 2.7; 95% CI: 1.2-6.0) than boys (RR, 1.4; 95% CI: 0.9-2.0). Later start of stimulant drug treatment of attention-deficit/hyperactivity disorder is associated with academic decline in mathematicsPfizer Novartis University of Iceland Icelandic Centre for Research (RANNIS

Condensation in nongeneric trees

We study nongeneric planar trees and prove the existence of a Gibbs measure on infinite trees obtained as a weak limit of the finite volume measures. It is shown that in the infinite volume limit there arises exactly one vertex of infinite degree and the rest of the tree is distributed like a subcritical Galton-Watson tree with mean offspring probability $m<1$. We calculate the rate of divergence of the degree of the highest order vertex of finite trees in the thermodynamic limit and show it goes like $(1-m)N$ where $N$ is the size of the tree. These trees have infinite spectral dimension with probability one but the spectral dimension calculated from the ensemble average of the generating function for return probabilities is given by $2\beta -2$ if the weight $w_n$ of a vertex of degree $n$ is asymptotic to $n^{-\beta}$.Comment: 57 pages, 14 figures. Minor change

State of fish populations in small forest lakes in the Norwegian, Finnish and Russian area

Appendix 9/15 of the publication "State of the environment in the Norwegian, Finnish and Russian border area 2007" (The Finnish Environment 6/2007)

The Storage and In-Use Stability of mRNA Vaccines and Therapeutics: Not A Cold Case

The remarkable impact of mRNA vaccines on mitigating disease and improving public health has been amply demonstrated during the COVID-19 pandemic. Many new mRNA-based vaccine and therapeutic candidates are in development, yet the current reality of their stability limitations requires their frozen storage. Numerous challenges remain to improve formulated mRNA stability and enable refrigerator storage, and this review provides an update on developments to tackle this multi-faceted stability challenge. We describe the chemistry underlying mRNA degradation during storage and highlight how lipid nanoparticle (LNP) formulations are a double-edged sword: while LNPs protect mRNA against enzymatic degradation, interactions with and between LNP excipients introduce additional risks for mRNA degradation. We also discuss strategies to improve mRNA stability both as a drug substance (DS) and a drug product (DP) including the (1) design of the mRNA molecule (nucleotide selection, primary and secondary structures), (2) physical state of the mRNA-LNP complexes, (3) formulation composition and purity of the components, and (4) DS and DP manufacturing processes. Finally, we summarize analytical control strategies to monitor and assure the stability of mRNA-based candidates, and advocate for an integrated analytical and formulation development approach to further improve their storage, transport, and in-use stability profiles

GPs' opinions of public and industrial information regarding drugs: a cross-sectional study

Background: General Practitioners {GP} in Sweden prescribe more than 50% of all prescriptions. Scientific knowledge on the opinions of GPs regarding drug information has been sparse. Such knowledge could be valuable when designing evidence-based drug information to GPs. GPs' opinions on public- and industry-provided drug information are presented in this article. Methods: A cross-sectional study using a questionnaire was answered by 368 GPs at 97 primary-health care centres {PHCC}. The centres were invited to participate by eight out of 29 drug and therapeutic committees {DTCs}. A multilevel model was used to analyse associations between opinions of GPs regarding drug information and whether the GPs worked in public sector or in a private enterprise, their age, sex, and work experience. PHCC and geographical area were included as random effects. Results: About 85% of the GPs perceived they received too much information from the industry, that the quality of public information was high and useful, and that the main task of public authorities was to increase the GPs' knowledge of drugs. Female GPs valued information from public authorities to a much greater extent than male GPs. Out of the GPs, 93% considered the main task of the industry was to promote sales. Differences between the GPs' opinions between PHCCs were generally more visible than differences between areas. Conclusions: Some kind of incentives could be considered for PHCCs that actively reduce drug promotion from the industry. That female GPs valued information from public authorities to a much greater extent than male GPs should be taken into consideration when designing evidence-based drug information from public authorities to make implementation easier