Multichannel seismic reflection data collected in July 2002 at the Endeavour Segment, Juan de Fuca Ridge, show a midcrustal reflector underlying all of the known high‐temperature hydrothermal vent ...fields in this area. On the basis of the character and geometry of this reflection, its similarity to events at other spreading centers, and its polarity, we identify this as a reflection from one or more crustal magma bodies rather than from a hydrothermal cracking front interface. The Endeavour magma chamber reflector is found under the central, topographically shallow section of the segment at two‐way traveltime (TWTT) values of 0.9–1.4 s (∼2.1–3.3 km) below the seafloor. It extends approximately 24 km along axis and is shallowest beneath the center of the segment and deepens toward the segment ends. On cross‐axis lines the axial magma chamber (AMC) reflector is only 0.4–1.2 km wide and appears to dip 8–36° to the east. While a magma chamber underlies all known Endeavour high‐temperature hydrothermal vent fields, AMC depth is not a dominant factor in determining vent fluid properties. The stacked and migrated seismic lines also show a strong layer 2a event at TWTT values of 0.30 ± 0.09 s (380 ± 120 m) below the seafloor on the along‐axis line and 0.38 ± 0.09 s (500 ± 110 m) on the cross‐axis lines. A weak Moho reflection is observed in a few locations at TWTT values of 1.9–2.4 s below the seafloor. By projecting hypocenters of well‐located microseismicity in this region onto the seismic sections, we find that most axial earthquakes are concentrated just above the magma chamber and distributed diffusely within this zone, indicating thermal‐related cracking. The presence of a partially molten crustal magma chamber argues against prior hypotheses that hydrothermal heat extraction at this intermediate spreading ridge is primarily driven by propagation of a cracking front down into a frozen magma chamber and indicates that magmatic heat plays a significant role in the hydrothermal system. Morphological and hydrothermal differences between the intermediate spreading Endeavour and fast spreading ridges are attributable to the greater depth of the Endeavour AMC and the corresponding possibility of axial faulting.
Background: Diabetes mellitus is a major risk factor for cardiovascular disease and is associated with a proinflammatory and prothrombotic state. We investigated whether CD40 ligand (L) expression ...and platelet–monocyte aggregation are increased in patients with type 1 diabetes.
Methods: Serum C-reactive protein (CRP) and soluble (s) CD40L concentrations, platelet surface CD40L expression and platelet–monocyte aggregates were measured in 22 patients with uncomplicated type 1 diabetes and 22 age- and sex-matched non-diabetic control subjects.
Results: In comparison to controls, patients with type 1 diabetes had higher serum CRP concentrations (3.29 ± 0.9
mg/L versus 0.99 ± 0.2
mg/L,
P = 0.01), serum sCD40L concentrations (10.0 ± 1.4
ng/mL versus 4.6 ± 0.6
ng/mL,
P = 0.006), and platelet surface expression of CD40L (13.8 ± 0.9% versus 8.5 ± 1.1%,
P < 0.001). Platelet–monocyte aggregates were also significantly elevated in type 1 diabetes (35.9 ± 3.3% versus 26.4 ± 2.9%,
P = 0.005;
n = 10). We also observed a significant correlation between plasma glucose and serum CRP (
r = 0.53,
P = 0.01) as well as platelet–monocyte aggregates (
r = 0.69,
P = 0.03).
Conclusions: Type 1 diabetes is associated with increased CD40L expression and platelet–monocyte aggregation, which may contribute to the proinflammatory and prothrombotic state as well as the accelerated atherogenesis associated with this disorder.
Lower parental education has been linked to adverse youth mental health outcomes. However, the relationship between parental education and youth suicidal behaviours remains unclear. We explored the ...association between parental education and youth suicidal ideation and attempts, and examined whether sociocultural contexts moderate such associations.
We conducted a systematic review and meta-analysis with a systematic literature search in PubMed, PsycINFO, Medline and Embase from 1900 to December 2020 for studies with participants aged 0-18, and provided quantitative data on the association between parental education and youth suicidal ideation and attempts (death included). Only articles published in English in peer-reviewed journals were considered. Two authors independently assessed eligibility of the articles. One author extracted data e.g. number of cases and non-cases in each parental education level, effect sizes in forms of odds ratios (ORs) or beta coefficients. We then calculated pooled ORs using a random-effects model and used moderator analysis to investigate heterogeneity.
We included a total of 59 articles (63 study samples, totalling 2 738 374 subjects) in the meta-analysis. Lower parental education was associated with youth suicidal attempts OR = 1.12, 95% Confidence Interval (CI) = 1.04-1.21 but not with suicidal ideation (OR = 1.05, 95% CI = 0.98-1.12). Geographical region and country income level moderated the associations. Lower parental education was associated with an increased risk of youth suicidal attempts in Northern America (OR = 1.26, 95% CI = 1.10-1.45), but with a decreased risk in Eastern and South-Eastern Asia (OR = 0.72, 95% CI = 0.54-0.96). An association of lower parental education and increased risk of youth suicidal ideation was present in high- income countries (HICs) (OR = 1.14, 95% CI = 1.05-1.25), and absent in low- and middle-income countries (LMICs) (OR = 0.91, 95% CI = 0.77-1.08).
The association between youth suicidal behaviours and parental education seems to differ across geographical and economical contexts, suggesting that cultural, psychosocial or biological factors may play a role in explaining this association. Although there was high heterogeneity in the studies reviewed, this evidence suggests that the role of familial sociodemographic characteristics in youth suicidality may not be universal. This highlights the need to consider cultural, as well as familial factors in the clinical assessment and management of youth's suicidal behaviours in our increasingly multicultural societies, as well as in developing prevention and intervention strategies for youth suicide.
In this study, the ability of porous silicon nanoparticles (PSi NPs) to entrap and deliver nitric oxide (NO) as an effective antibacterial agent is tested against different Gram-positive and ...Gram-negative bacteria. NO was entrapped inside PSi NPs functionalized by means of the thermal hydrocarbonization (THC) process. Subsequent reduction of nitrite in the presence of
d
-glucose led to the production of large NO payloads without reducing the biocompatibility of the PSi NPs with mammalian cells. The resulting PSi NPs demonstrated sustained release of NO and showed remarkable antibacterial efficiency and anti-biofilm-forming properties. These results will set the stage to develop antimicrobial nanoparticle formulations for applications in chronic wound treatment.
A record fuel hot-spot pressure P_{hs}=56±7 Gbar was inferred from x-ray and nuclear diagnostics for direct-drive inertial confinement fusion cryogenic, layered deuterium-tritium implosions on the ...60-beam, 30-kJ, 351-nm OMEGA Laser System. When hydrodynamically scaled to the energy of the National Ignition Facility, these implosions achieved a Lawson parameter ∼60% of the value required for ignition A. Bose et al., Phys. Rev. E 93, 011201(R) (2016), similar to indirect-drive implosions R. Betti et al., Phys. Rev. Lett. 114, 255003 (2015), and nearly half of the direct-drive ignition-threshold pressure. Relative to symmetric, one-dimensional simulations, the inferred hot-spot pressure is approximately 40% lower. Three-dimensional simulations suggest that low-mode distortion of the hot spot seeded by laser-drive nonuniformity and target-positioning error reduces target performance.
The changes in the mean-square charge radius (relative to 209Bi), magnetic dipole, and electric quadrupole moments of 187, 188, 189, 191Bi were measured using the in-source resonance-ionization ...spectroscopy technique at ISOLDE (CERN). A large staggering in radii was found in 187, 188, 189Big, manifested by a sharp radius increase for the ground state of 188Bi relative to the neighboring 187, 189Big. A large isomer shift was also observed for 188Bim. Both effects happen at the same neutron number, N = 105 , where the shape staggering and a similar isomer shift were observed in the mercury isotopes. Experimental results are reproduced by mean-field calculations where the ground or isomeric states were identified by the blocked quasiparticle configuration compatible with the observed spin, parity, and magnetic moment.
The determination of melt distribution in the crust and the nature of the crust–mantle boundary (the ‘Moho’) is fundamental to the understanding of crustal accretion processes at oceanic spreading ...centres. Upper-crustal magma chambers have been imaged beneath fast- and intermediate-spreading centres but it has been difficult to image structures beneath these magma sills. Using three-dimensional seismic reflection images, here we report the presence of Moho reflections beneath a crustal magma chamber at the 9° 03′ N overlapping spreading centre, East Pacific Rise. Our observations highlight the formation of the Moho at zero-aged crust. Over a distance of less than 7 km along the ridge crest, a rapid increase in two-way travel time of seismic waves between the magma chamber and Moho reflections is observed, which we suggest is due to a melt anomaly in the lower crust. The amplitude versus offset variation of reflections from the magma chamber shows a coincident region of higher melt fraction overlying this anomalous region, supporting the conclusion of additional melt at depth.
Terminal deletions of chromosome 10p result in a DiGeorge-like phenotype
that includes hypoparathyroidism, heart defects, immune deficiency, deafness
and renal malformations. Studies in patients with ...10p deletions
have defined two non-overlapping regions that contribute to this complex phenotype.
These are the DiGeorge critical region II (refs 1, 2), which is located on 10p13-14, and the region for the
hypoparathyroidism, sensorineural deafness, renal anomaly (HDR) syndrome (Mendelian Inheritance in Man number 146255), which
is located more telomeric (10p14-10pter). We have
performed deletion-mapping studies in two HDR patients, and here we define
a critical 200-kilobase region which contains the GATA3 gene.
This gene belongs to a family of zinc-finger transcription factors that are
involved in vertebrate embryonic development. Investigation
for GATA3 mutations in three other HDR probands identified one nonsense
mutation and two intragenic deletions that predicted a loss of function, as
confirmed by absence of DNA binding by the mutant GATA3 protein. These results
show that GATA3 is essential in the embryonic development of the parathyroids,
auditory system and kidneys, and indicate that other GATA family members may
be involved in the aetiology of human malformations.
PDF
