Experiments on the twisted vortex state in superfluid 3He-B

We have performed measurements and numerical simulations on a bundle of vortex lines which is expanding along a rotating column of initially vortex-free 3He-B. Expanding vortices form a propagating front: Within the front the superfluid is involved in rotation and behind the front the twisted vortex state forms, which eventually relaxes to the equilibrium vortex state. We have measured the magnitude of the twist and its relaxation rate as function of temperature above 0.3Tc. We also demonstrate that the integrity of the propagating vortex front results from axial superfluid flow, induced by the twist.Comment: prepared for proceedings of the QFS2007 symposium in Kaza

Internalization of a polysialic acid-binding Escherichia coli bacteriophage into eukaryotic neuroblastoma cells

Eukaryotic organisms are continuously exposed to bacteriophages, which are efficient gene transfer agents in bacteria. However, bacteriophages are considered not to pass the eukaryotic cell membrane and enter nonphagocytic cells. Here we report the binding and penetration of Escherichia coli PK1A2 bacteriophage into live eukaryotic neuroblastoma cells in vitro. The phage interacts with cell surface polysialic acid, which shares structural similarity with the bacterial phage receptor. Using fluorescence and electron microscopy, we show that phages are internalized via the endolysosomal route and persist inside the human cells up to one day without affecting cell viability. Phage capsid integrity is lost in lysosomes, and the phage DNA is eventually degraded. We did not detect the entry of phage DNA into the nucleus; however, we speculate that this might occur as a rare event, and propose that this potential mechanism could explain prokaryote-eukaryote gene flow.Peer reviewe

Structure of surface vortex sheet between two rotating 3He superfluids

We study a two-phase sample of superfluid 3He where vorticity exists in one phase (3He-A) but cannot penetrate across the interfacial boundary to a second coherent phase (3He-B). We calculate the bending of the vorticity into a surface vortex sheet on the interface and solve the internal structure of this new type of vortex sheet. The compression of the vorticity from three to two dimensions enforces a structure which is made up of half-quantum units, independently of the structure of the source vorticity in the bulk. These results are consistent with our NMR measurements.Comment: 4 pages, 4 figure

Superconducting Nb-film LC resonator

Sputtered Nb thin-film LC resonators for low frequencies at 0.5 MHz have been fabricated and tested in the temperature range 0.05--1 K in magnetic fields up to 30 mT. Their Q value increases towards decreasing temperature as sqrt(T) and reaches 10^3 at 0.05 K. As a function of magnetic field Q is unstable and displays variations up to 50%, which are reproducible from one field sweep to the next. These instabilities are attributed to dielectric losses in the plasma deposited SiO_2 insulation layer, since the thin-film coil alone reaches a Q > 10^5 at 0.05 K.Comment: 6 pages, 7 figures, submitted to Review of Scientific Instrument

Increase in outbreaks of gastroenteritis linked to bathing water in Finland in summer 2014

Peer reviewe

Comparative Long-term Adverse Effects Elicited by Invasive Group B and C Meningococcal Infections

No vaccine is universally active against serogroup B meningococci. A theoretical concern that serogroup B capsular polysaccharide may induce autoimmunity hampers vaccine development. We studied long-term complications in 120 survivors of meningococcal disease. No evidence of increased autoimmune, neurological, or psychiatric disease was noted

Family Partner: Study protocol for a pilot randomised study of a home-visitation intervention in Norway

Abstract Aim: Every year, about 5% of children in Norway experience severe child maltreatment and need support from the child welfare services. However, research-supported interventions for this group are lacking. The current study piloted an intensive home-visitation intervention, Family Partner, which aims to reduce child maltreatment among at-risk parents by improving parental skills, agency and trust in the welfare services, and children’s well-being. The randomised controlled trial piloted in this study examines the acceptability of the Family Partner intervention for staff and families and evaluates its feasibility for a full-scale randomised controlled trial. Methods: This protocol outlines a prospective, parallel, pilot randomised trial of the Family Partner intervention in three Norwegian municipal child welfare services. The participants are families with children under 12 years of age, where the parents are identified as having challenges. Families in the treatment group receive the Family Partner intervention, while families in the control group receive ordinary child welfare services. Data are collected at baseline, and at 3, 6, 12 and 18 months after recruitment. The pilot study monitor retention and adherence to inform the feasibility of a future full-scale randomised study. To assess the acceptability of the trial and intervention, a subsample of the participating families, as well as the family partners and representatives of the child welfare services in each municipality, are invited to complete qualitative interviews. Conclusions: The results will guide the design of a fully powered randomised controlled trial of the Family Partner intervention compared with ordinary child welfare services. Trial registration: ClinicalTrials.gov identifier: NCT04957394; Pilot Trial of Family Partner: a Child Maltreatment Prevention Intervention (FAMPART); registered on 12 July 2021

Interventions to reduce child maltreatment: A systematic review with a narrative synthesis

Abstract Child maltreatment has been a prominent topic on the political agenda for the past decade. However, while there are several types of interventions that can potentially benefit the prevention of child maltreatment, uncertainties remain regarding the transferability of these interventions to different contexts and their overall impact. Consequently, we conducted a systematic review of intervention studies aimed at preventing child maltreatment. We searched for studies published between 2016 and 2021, using predefined keywords from various bibliographical databases including PsycINFO, SocINDEX, Social Care Online, Web of Science, and ASSIA. The initial literature search yielded 3221 studies based on titles and abstracts, after removing duplicates. Out of these, 251 studies were screened based on full texts, resulting in the selection of 56 studies that met our inclusion criteria and were retained for extraction and analysis. The screening and data extraction processes were conducted by at least two independent reviewers. Given the heterogeneity of the included studies, we performed a narrative synthesis and categorized the 56 studies based on intervention type, control condition, outcomes, effects and quality. The results indicated that most of the studies employed individual randomization, with the control group most often receiving treatment as usual. Home visiting programs and educational interventions emerged as the most prevalent types of interventions. The review also demonstrated that a significant number of the included studies reported positive effects on one or more outcomes, such as indicators of maltreatment, suboptimal parenting practices, and problematic child behaviors. While nearly one-third of the studies did not report an effect size, those that did reported varying types of effect sizes. Additionally, only a few studies met the assessed quality criteria

Expression of neural cell adhesion molecule and polysialic acid in human bone marrow-derived mesenchymal stromal cells

BACKGROUND: In order to develop novel clinical applications and to gain insights into possible therapeutic mechanisms, detailed molecular characterization of human bone marrow-derived mesenchymal stromal cells (hBM-MSCs) is needed. Neural cell adhesion molecule (NCAM, CD56) is a transmembrane glycoprotein modulating cell–cell and cell–matrix interactions. An additional post-translational modification of NCAM is the α2,8-linked polysialic acid (polySia). Because of its background, NCAM is often considered a marker of neural lineage commitment. Generally, hBM-MSCs are considered to be devoid of NCAM expression, but more rigorous characterization is needed. METHODS: We have studied NCAM and polySia expression in five hBM-MSC lines at mRNA and protein levels. Cell surface localization was confirmed by immunofluorescence staining and expression frequency in the donor-specific lines by flow cytometry. For the detection of poorly immunogenic polySia, a fluorochrome-tagged catalytically defective enzyme was employed. RESULTS: All five known NCAM isoforms are expressed in these cells at mRNA level and the three main isoforms are present at protein level. Both polysialyltransferases, generally responsible for NCAM polysialylation, are expressed at mRNA level, but only very few cells express polySia at the cell surface. CONCLUSIONS: Our results underline the need for a careful control of methods and conditions in the characterization of MSCs. This study shows that, against the generally held view, clinical-grade hBM-MSCs do express NCAM. In contrast, although both polysialyltransferase genes are transcribed in these cells, very few express polySia at the cell surface. NCAM and polySia represent new candidate molecules for influencing MSC interactions.Peer reviewe