Global DNA hypomethylation prevents consolidation of differentiation programs and allows reversion to the embryonic stem cell state.

DNA methylation patterns change dynamically during mammalian development and lineage specification, yet scarce information is available about how DNA methylation affects gene expression profiles upon differentiation. Here we determine genome-wide transcription profiles during undirected differentiation of severely hypomethylated (Dnmt1⁻/⁻) embryonic stem cells (ESCs) as well as ESCs completely devoid of DNA methylation (Dnmt1⁻/⁻;Dnmt3a⁻/⁻;Dnmt3b⁻/⁻ or TKO) and assay their potential to transit in and out of the ESC state. We find that the expression of only few genes mainly associated with germ line function and the X chromosome is affected in undifferentiated TKO ESCs. Upon initial differentiation as embryoid bodies (EBs) wild type, Dnmt1⁻/⁻ and TKO cells downregulate pluripotency associated genes and upregulate lineage specific genes, but their transcription profiles progressively diverge upon prolonged EB culture. While Oct4 protein levels are completely and homogeneously suppressed, transcription of Oct4 and Nanog is not completely silenced even at late stages in both Dnmt1⁻/⁻ and TKO EBs. Despite late wild type and Dnmt1⁻/⁻ EBs showing a much higher degree of concordant expression, after EB dissociation and replating under pluripotency promoting conditions both Dnmt1⁻/⁻ and TKO cells, but not wild type cells rapidly revert to expression profiles typical of undifferentiated ESCs. Thus, while DNA methylation seems not to be critical for initial activation of differentiation programs, it is crucial for permanent restriction of developmental fate during differentiation

Characterization of PvuRts1I endonuclease as a tool to investigate genomic 5–hydroxymethylcytosine

In mammalian genomes a sixth base, 5-hydroxymethylcytosine ( hm C), is generated by enzymatic oxidation of 5-methylcytosine ( m C). This discovery has raised fundamental questions about the functional relevance of hm C in mammalian genomes. Due to their very similar chemical structure, discrimination of the rare hm C against the far more abundant m C is technically challenging and to date no methods for direct sequencing of hm C have been reported. Here, we report on a purified recombinant endonuclease, PvuRts1I, which selectively cleaves hm C-containing sequences. We determined the consensus cleavage site of PvuRts1I as hm CN 11–12 /N 9–10 G and show first data on its potential to interrogate hm C patterns in mammalian genomes

Associations of university student life challenges with mental health and self-rated health: A longitudinal study with 6 months follow-up

Background: Mental health problems are highly prevalent among university students. Stress due to student life challenges may be a risk factor for poorer health. This study investigates to what extent student life challenges and changes therein are associated with mental health and self-rated health. Methods: In a longitudinal study with 568 Italian university students mental health was assessed using the Mental Health Inventory-5 (MHI-5) and self-rated health with a single item from the Short Form 36 Health Survey (SF36) (score ranges: 0-100) at baseline and at six months follow-up. Student life challenges were investigated using six subscales (score ranges: 1-4) of the Higher Education Stress Inventory (HESI). A between-within linear regression model was used to investigate whether a higher exposure to life challenges was associated with poorer health (between individuals) and whether changes in student life challenges were associated with changes in health (within individuals). Results: Higher exposure to student life challenges was associated with poorer mental health (b ranging from -5.3 to -10.3) and self-rated health (b ranging from -3.1 to -9.6). An increase in student life challenges within individuals was associated with poorer mental health and self-rated health, in particular for high workload (b up to -5.9), faculty shortcomings (b up to -5.7), and unsupportive climate (b up to -5.6). Discussion: Exposure to student life challenges and changes therein are associated with university students’ health. Our findings suggest that student life challenges may be a target for interventions to improve mental health and self-rated health among university students

Mental health among university students: The associations of effort-reward imbalance and overcommitment with psychological distress

Background: Mental health problems are highly prevalent among university students, but little is known about their underlying determinants. This study explores mental health among university students, the association between “effort-reward imbalance” (ERI), overcommitment and mental health, and to what extent ERI and overcommitment explain gender differences in mental health. Methods: Cross-sectional data were analyzed from 4760 Italian university students. The Kessler Psychological Distress Scale-10 was used to measure self-reported psychological distress, as an indicator of mental health, and the ERI – Student Questionnaire to measure effort, reward and overcommitment. The associations between ERI and overcommitment with psychological distress were estimated with multinomial logistic regression analyses. Results: 78.5% of the respondents experienced psychological distress, with 21.3%, 21.1%, and 36.1% reporting respectively mild, moderate and severe psychological distress. Female students were more likely to report moderate and severe psychological distress. ERI and overcommitment were strongly associated with severe psychological distress with ORs respectively up to 19.9 (95% CI: 12.2–32.5) and 22.2 (95% CI: 16.1–30.7). ERI and overcommitment explained part of the higher odds of severe psychological distress among female students comparing to males, attenuating the ORs from 2.3 (95% CI: 1.9–2.7) to 1.4 (95% CI: 1.2–1.7). Limitations: This cross-sectional study was performed on a large, but convenient sample. Discussion: More than one out of three students reported severe psychological distress. Decreasing ERI and overcommitment may be beneficial in the prevention of psychological distress among university students and may reduce gender differences in psychological distress. Longitudinal studies are needed to further investigate these associations

Dissidents and God-Talk in the Johannine Epistles

Peer reviewe

Employment and insurance outcomes and factors associated with employment among long-term thyroid cancer survivors:a population-based study from the PROFILES registry

Contains fulltext : 172452.pdf (Publisher’s version ) (Open Access)PURPOSE: To obtain insight into employment and insurance outcomes of thyroid cancer survivors and to examine the association between not having employment and other factors including quality of life. METHODS: In this cross-sectional population-based study, long-term thyroid cancer survivors from the Netherlands participated. Clinical data were collected from the cancer registry. Information on employment, insurance, socio-demographic characteristics, long-term side effects, and quality of life was collected with questionnaires. RESULTS: Of the 223 cancer survivors (response rate 87 %), 71 % were employed. Of the cancer survivors who tried to obtain insurance, 6 % reported problems with obtaining health care insurance, 62 % with life insurance, and 16 % with a mortgage. In a multivariate logistic regression analysis, higher age (OR 1.07, CI 1.02-1.11), higher level of fatigue (OR 1.07, CI 1.01-1.14), and lower educational level (OR 3.22, CI 1.46-7.09) were associated with not having employment. Employment was associated with higher quality of life. CONCLUSIONS: Many thyroid cancer survivors face problems when obtaining a life insurance, and older, fatigued, and lower educated thyroid cancer survivors may be at risk for not having employment

Double Spin Asymmetries A_NN and A_SS at sqrt{s}=200 GeV in Polarized Proton-Proton Elastic Scattering at RHIC

We present the first measurements of the double spin asymmetries A_NN and A_SS at sqrt{s}=200 GeV, obtained by the pp2pp experiment using polarized proton beams at the Relativistic Heavy Ion Collider (RHIC). The data were collected in the four momentum transfer t range 0.01<|t|<0.03 (GeV/c)^2. The measured asymmetries, which are consistent with zero, allow us to estimate upper limits on the double helicity-flip amplitudes phi_2 and phi_4 at small t as well as on the difference Delta(sigma_T) between the total cross sections for transversely polarized protons with antiparallel or parallel spin orientations.Comment: 13 pages with 3 figures. Final version accepted by Phys. Lett.

Sensitive enzymatic quantification of 5-hydroxymethylcytosine in genomic DNA

The recent discovery of genomic 5-hydroxymethylcytosine (hmC) and mutations affecting the respective Tet hydroxylases in leukemia raises fundamental questions about this epigenetic modification. We present a sensitive method for fast quantification of genomic hmC based on specific transfer of radiolabeled glucose to hmC by a purified glucosyltransferase. We determined hmC levels in various adult tissues and differentiating embryonic stem cells and show a correlation with differential expression of tet genes

Measurement of the neutron F2 structure function via spectator tagging with CLAS

We report on the first measurement of the F2 structure function of the neutron from semi-inclusive scattering of electrons from deuterium, with low-momentum protons detected in the backward hemisphere. Restricting the momentum of the spectator protons to < 100 MeV and their angles to < 100 degrees relative to the momentum transfer allows an interpretation of the process in terms of scattering from nearly on-shell neutrons. The F2n data collected cover the nucleon resonance and deep-inelastic regions over a wide range of Bjorken x for 0.65 < Q2 < 4.52 GeV2, with uncertainties from nuclear corrections estimated to be less than a few percent. These measurements provide the first determination of the neutron to proton structure function ratio F2n/F2p at 0.2 < x < 0.8 with little uncertainty due to nuclear effects.Comment: 6 pages, 3 page