8,970 research outputs found
Natural environments and suicide mortality in the Netherlands: a cross-sectional, ecological study
Background:
Natural outdoor environments, such as green spaces (ie, grass, forests, or parks), blue spaces (ie, visible bodies of fresh or salt water), and coastal proximity, have been increasingly shown to promote mental health. However, little is known about how and the extent to which these natural environments are associated with suicide mortality. Our aim was to investigate whether the availability of green space and blue space within people's living environments and living next to the coast are protective against suicide mortality.
Methods:
In this cross-sectional, ecological study, we analysed officially confirmed deaths by suicide between 2005 and 2014 per municipality in the Netherlands. We calculated indexes to measure the proportion of green space and blue space per municipality and the coastal proximity of each municipality using a geographical information system. We fitted Bayesian hierarchical Poisson regressions to assess associations between suicide risk, green space, blue space, and coastal proximity, adjusted for risk and protective factors.
Findings:
Municipalities with a large proportion of green space (relative risk 0·879, 95% credibility interval 0·779–0·991) or a moderate proportion of green space (0·919, 0·846–0·998) showed a reduced suicide risk compared with municipalities with less green space. Green space did not differ according to urbanicity in relation to suicide. Neither blue space nor coastal proximity was associated with suicide risk. The geographical variation in the residual relative suicide risk was substantial and the south of the Netherlands was at high risk.
Interpretation:
Our findings support the notion that exposure to natural environments, particularly to greenery, might have a role in reducing suicide mortality. If confirmed by future studies on an individual level, the consideration of environmental exposures might enrich suicide prevention programmes
Imprints of Environment on Cluster and Field Late-type Galaxies at z~1
We present a comparison of late-type galaxies (Sa and later) in intermediate
redshift clusters and the field using ACS imaging of four cluster fields:
CL0152-1357, CL1056-0337 (MS1054), CL1604+4304, and CL1604+4321. Concentration,
asymmetry, and clumpiness parameters are calculated for each galaxy in blue
(F606W or F625W) and red (F775W or F814W) filters. Galaxy half-light radii,
disk scale lengths, color gradients, and overall color are compared. We find
marginally significant differences in the asymmetry distributions of spiral and
irregular galaxies in the X-ray luminous and X-ray faint clusters. The massive
clusters contain fewer galaxies with large asymmetries. The physical sizes of
the cluster and field populations are similar; no significant differences are
found in half-light radii or disk scale lengths. The most significant
difference is in rest-frame color. Late-type cluster galaxies are
significantly redder, magnitudes at rest-frame , than their
field counterparts. Moreover, the intermediate-redshift cluster galaxies tend
to have blue inward color gradients, in contrast to the field galaxies, but
similar to late-type galaxies in low redshift clusters. These blue inward color
gradients are likely to be the result of enhanced nuclear star formation rates
relative to the outer disk. Based on the significant rest-frame color
difference, we conclude that late-type cluster members at are not a
pristine infalling field population; some difference in past and/or current
star formation history is already present. This points to high redshift
``groups'', or filaments with densities similar to present-day groups, as the
sites where the first major effects of environment are imprinted.Comment: updated titl
Elaboration and characterization of Fe1–xO thin films sputter deposited from magnetite target
Majority of the authors report elaboration of iron oxide thin films by reactive magnetron sputtering from an iron target with Ar–O2 gas mixture. Instead of using the reactive sputtering of a metallic target we report here the preparation of Fe1–xOthin films, directly sputtered froma magnetite target in a pure argon gas flow with a bias power applied. This oxide is generally obtained at very low partial oxygen pressure and high temperature.We showed that bias sputtering which can be controlled very easily can lead to reducing conditions during deposition of oxide thin film on simple glass substrates. The proportion of wustite was directly adjusted bymodifying the power of the substrate polarization. Atomic force microscopy was used to observe these nanostructured layers. Mössbauer measurements and electrical properties versus bias polarization and annealing temperature are also reported
Statics and dynamics of single DNA molecules confined in nanochannels
The successful design of nanofluidic devices for the manipulation of biopolymers requires an understanding of how the predictions of soft condensed matter physics scale with device dimensions. Here we present measurements of DNA extended in nanochannels and show that below a critical width roughly twice the persistence length there is a crossover in the polymer physics
Highlighting the Mechanistic Relationship Between Perinatal Depression and Preeclampsia: A Scoping Review
Background: Although there is scientific literature supporting an association between depression and preeclampsia (PE), little is known about the underlying mechanistic pathways that may explain these observed associations. Thus, this study aimed to outline the relationship between depression and PE, and to highlight the underlying cardiovascular and metabolic risk factors that are common to both. Methods: A scoping review of the literature was conducted in Medline, Scopus, and Web of Science. Results: From 706 articles initially identified, 23 articles met the inclusion criteria and were included in this review. Although some studies reported a positive association between PE and postpartum depressive symptoms, challenges comparing different methodologies, measurement instruments and when measurements were administered, and patient populations do not permit a decisive conclusion. In addition, very few studies addressed potential underlying mechanisms that may be contributing to observed associations; thus, a secondary search was conducted to identify cardiovascular and metabolic risk factors that are common to both depression and PE. Conclusion: The cardiovascular and metabolic risk factors (i.e., increased inflammation and oxidative stress and decreased vascular and endothelial function) common to both depression and PE suggest that these factors may contribute as underlying mechanisms in both conditions. These similarities underscore the importance to better understand these mechanisms so preventative and therapeutic strategies could be developed to improve maternal health
Inheritance of physico-chemical properties and ROS generation by carbon quantum dots derived from pyrolytically carbonized bacterial sources
Bacteria are frequently used in industrial processes and nutrient supplementation to restore a healthy human microflora, but use of live bacteria is often troublesome. Here, we hypothesize that bacterially-derived carbon-quantum-dots obtained through pyrolytic carbonization inherit physico-chemical properties from probiotic and pathogenic source-bacteria. Carbon-quantum-dots carbonized at reaction-temperatures below 200 °C had negligible quantum-yields, while temperatures above 220 °C yielded poor water-suspendability. Fourier-transform infrared-spectroscopy demonstrated preservation of amide absorption bands in carbon-quantum-dots derived at intermediate temperatures. X-ray photoelectron-spectroscopy indicated that the at%N in carbon-quantum-dots increased with increasing amounts of protein in source-bacterial surfaces. Carbonization transformed hydrocarbon-like bacterial surface compounds into heterocyclic aromatic-carbon structures, evidenced by a broad infrared absorption band (920-900 cm−1) and the presence of carbon in C–C functionalities of carbon-quantum-dots. The chemical composition of bacterially-derived carbon-quantum-dots could be explained by the degradation temperatures of main bacterial cell surface compounds. All carbon-quantum-dots generated reactive-oxygen-species, most notably those derived from probiotic lactobacilli, carrying a high amount of surface protein. Concluding, amide functionalities in carbon-quantum-dots are inherited from surface proteins of source-bacteria, controlling reactive-oxygen-species generation. This paves the way for applications of bacterially-derived carbon-quantum-dots in which reactive-oxygen-species generation is essential, instead of hard-to-use live bacteria, such as in food supplementation or probiotic-assisted antibiotic therapy
Visualization of Bacterial Colonization and Cellular Layers in a Gut-on-a-Chip System Using Optical Coherence Tomography
Imaging of cellular layers in a gut-on-a-chip system has been confined to two-dimensional (2D)-imaging through conventional light microscopy and confocal laser scanning microscopy (CLSM) yielding three-dimensional- and 2D-cross-sectional reconstructions. However, CLSM requires staining and is unsuitable for longitudinal visualization. Here, we compare merits of optical coherence tomography (OCT) with those of CLSM and light microscopy for visualization of intestinal epithelial layers during protection by a probiotic Bifidobacterium breve strain and a simultaneous pathogen challenge by an Escherichia coli strain. OCT cross-sectional images yielded film thicknesses that coincided with end-point thicknesses derived from cross-sectional CLSM images. Light microscopy on histological sections of epithelial layers at the end-point yielded smaller layer thicknesses than OCT and CLSM. Protective effects of B. breve adhering to an epithelial layer against an E. coli challenge included the preservation of layer thickness and membrane surface coverage by epithelial cells. OCT does not require staining or sectioning, making OCT suitable for longitudinal visualization of biological films, but as a drawback, OCT does not allow an epithelial layer to be distinguished from bacterial biofilms adhering to it. Thus, OCT is ideal to longitudinally evaluate epithelial layers under probiotic protection and pathogen challenges, but proper image interpretation requires the application of a second method at the end-point to distinguish bacterial and epithelial films
The fine-tuning of TRAF2-GSTP1-1 interaction: effect of ligand binding and in situ detection of the complex
We provide the first biochemical evidence of a direct interaction between the glutathione transferase P1-1 (GSTP1-1) and the TRAF domain of TNF receptor-associated factor 2 (TRAF2), and describe how ligand binding modulates such an equilibrium. The dissociation constant of the heterocomplex is Kd¼0.3lM; however the binding affinity strongly decreases when the active site of GSTP1-1 is occupied by the substrate GSH (KdZ2.6lM) or is inactivated by oxidation (Kd¼1.7lM). This indicates that GSTP1-1’s TRAF2-binding region involves the GSH-binding site. The GSTP1-1 inhibitor NBDHEX further decreases the complex’s binding affinity, as compared with when GSH is the only ligand; this suggests that the hydrophobic portion of the GSTP1-1 active site also contributes to the interaction. We therefore hypothesize that TRAF2 binding inactivates GSTP1-1; however, analysis of the data, using a model taking into account the dimeric nature of GSTP1-1, suggests that GSTP1-1 engages only one subunit in the complex, whereas the second subunit maintains the catalytic activity or binds to other proteins. We also analyzed GSTP1-1’s association with TRAF2 at the cellular level. The TRAF2–GSTP1-1 complex was constitutively present in U-2OS cells, but strongly decreased in S, G2 and M phases. Thus the interaction appears regulated in a cell cycle-dependent manner. The variations in the levels of individual proteins seem too limited to explain the complex’s drastic decline observed in cells progressing from the G0/G1 to the S–G2–M phases. Moreover, GSH’s intracellular content was so high that it always saturated GSTP1-1. Interestingly, the addition of NBDHEX maintains the TRAF2–GSTP1-1 complex at low levels, thus causing a prolonged cell cycle arrest in the G2/M phase. Overall, these findings suggest that a reversible sequestration of TRAF2 into the complex may be crucial for cell cycle progression and that multiple factors are involved in the fine-tuning of this interactio
- …