Between approximately 17,500 and 15,000 years ago, the Atlantic meridional overturning circulation weakened substantially in response to meltwater discharges from disintegrating Northern Hemispheric ...glacial ice sheets. The global effects of this reorganization of poleward heat flow in the North Atlantic extended to Antarctica and the North Pacific. Here we present evidence from North Pacific paleo surface proxy data, a compilation of marine radiocarbon age ventilation records, and global climate model simulations to suggest that during the early stages of the Last Glacial Termination, deep water extending to a depth of approximately 2500 to 3000 meters was formed in the North Pacific. A switch of deepwater formation between the North Atlantic and the North Pacific played a key role in regulating poleward oceanic heat transport during the Last Glacial Termination.
As frequently added to adhesives, the mono-functional monomer 2-hydroxyethyl methacrylate (HEMA) acts as co-solvent and improves surface wetting. Nevertheless, HEMA promotes watersorption and ...hydrolysis at adhesive interfaces, affecting bond durability to dentin. This study investigated if two acrylamide co-monomer alternatives could replace HEMA in experimental adhesive-resin formulations as part of 3/2-step universal adhesives applied, respectively, in etch-and-rinse (E&R) and self-etch (SE) bonding modes.
Upon priming dentin with the 10-MDP-based Clearfil SE Bond 2’ primer (‘C-SE2p’; Kuraray Noritake), three experimental adhesive resins, consisting of 50 wt.% Bis-GMA, 15 wt.% TEGDMA, and either 35 wt.% diethyl acrylamide (‘DEAA’), hydroxyethyl acrylamide (‘HEAA’) or HEMA (‘HEMA+’), were applied. The control HEMA-free adhesive resin contained 60 wt.% Bis-GMA and 40 wt.% TEGDMA (‘HEMA−’). All adhesives were evaluated for ‘immediate’ and ‘aged’ micro-tensile bond strength (μTBS) to dentin upon, respectively, 1-week (1w) and 6-month (6m) water storage, TEM adhesive-dentin interfacial interaction, 24-h and 6m three-point bending, contact-angle wetting, viscosity and watersorption.
Linear mixed-effects model statistics revealed significantly better bonding performance of the adhesives applied in E&R than SE mode, except for DEAA_1w, with the highest μTBSs recorded for DEAA and HEMA− applied in SE mode. In E&R mode, aging did not significantly reduce DEAA’s μTBS. Best wetting on primed dentin was recorded for HEMA+, significantly better than DEAA, further HEAA and HEMA−, these directly related to their viscosity. HEAA absorbed significantly more water than all other adhesive-resin formulations. HEMA−>DEAA>HEAA>HEMA+ was the significant order for 6m bending strength.
The acrylamide co-monomer DEAA could replace HEMA, while HEAA not.
Evaluation of foraminiferal test dissolution in deep‐sea sediments facilitates reconstruction of seawater chemistry. Here we observed test dissolution processes of the planktic foraminifera ...Trilobatus sacculifer, Globigerinoides ruber, and Neogloboquadrina dutertrei from midlatitudes of the western North Pacific; in these three species, we tested the ability of a new dissolution index using data from X‐ray micro‐computed tomography scanning. Although the dissolution process of foraminiferal tests differed slightly among species, dissolution of all species was equally assessed by the calcite density distribution (%Low‐CT‐number calcite volume) calculated from the CT number histogram. In T. sacculifer and G. ruber, the test area density, a conventional proxy for assessing test condition based on weight measurement, is affected by variations in the thickness of the outermost chamber wall; thus, this conventional proxy can be affected by sea surface conditions during test calcification. In contrast, the relationship between the %Low‐CT‐number calcite volume of tests and the deep seawater calcite saturation state suggests that X‐ray micro‐computed tomography scanning is applicable for evaluating the intensity of foraminiferal test dissolution at the undersaturated deep seafloor in this area and is an invaluable proxy for detecting deep seawater carbonate ion concentration changes on glacial‐interglacial timescales.
Key Points
Dissolution process of planktic foraminiferal tests was observed by X‐ray micro‐computed tomography
Progression of test dissolution was assessed by using a new index based on X‐ray micro‐computed tomography‐number histograms
The conventional proxy of test area density is considered to be controlled by factors other than deep seawater saturation state
Studies on recruitment variability in Japanese sardine Sardinops melanostictus and Japanese anchovy Engraulis japonicus have focused on the mixed water region (MWR) and its southern waters in the ...western North Pacific. However, the availability of suitable prey for larval and juvenile sardines and anchovy in the MWR was poorly known. Here, we describe the feeding habits and prey environments of larval and juvenile Japanese sardine and Japanese anchovy in the MWR from 1970−2013, during a time of dramatic changes in sardine and anchovy stocks. Fish and zooplankton were sampled from April to July using a variety of nets. Larval and juvenile sardine and anchovy fed on similar prey, such as copepodites of calanoid (e.g. Paracalanus spp.) and poecilostomatoid (e.g. Corycaeus affinis and Oncaea spp.) copepods, except for between 1988 and 1991. The abundance of dominant copepod prey species varied with sea surface temperature, with P. parvus and C. affinis most abundant at approximately 16 to 17°C and Oncaea spp. at temperatures exceeding 20°C. Decreased abundance of P. parvus after 1988 coincided with poor sardine recruitment. Although larval and juvenile sardine and anchovy have similar diets in the MWR, temperature possibly affects the distribution and abundance of their prey, and consequently fish stocks in the Kuroshio-Oyashio ecosystem.
A medial meniscus posterior root tear (MMPRT) is defined as an injury to the posterior meniscal insertion on the tibia. In MMPRT, the medial meniscus (MM) hoop function is damaged, and the MM ...undergoes a medial extrusion into the interior from the superior articular surface of the tibia. However, the details of MM position and movement during knee joint movement are unclear in MMPRT cases. The present study aims to evaluate MM position and movement via magnetic resonance imaging (MRI) examination of the MM posterior extrusion (MMPE) at knee flexion angles of 10° and 90°. We hypothesized that, during knee flexion, the MM will shift to the posterior and the posterior extrusion will increase compared to that when the knee is extended.
Twenty-four patients were diagnosed with symptomatic MMPRT on open MRI examination. Preoperative MMPE, anteroposterior interval (API) of the MM, and MM medial extrusion (MMME) at knee flexion angles of 10° and 90° were measured.
For patients with MMPRT, the MMPE increased from −4.77±1.43mm to 3.79±1.17mm (p<0.001) when the knee flexion angle increased from 10° to 90°. Further, flexing the knee from 10° to 90° decreased the API of the MM from 20.19±4.22mm to 16.41±5.14mm (p<0.001). MMME showed no significant change between knee flexion angles of 10° and 90°.
This study demonstrated that, in cases of MMPRT, the MMPE clearly increases when the knee is flexed to 90°, while MMME does not change. Our results suggest that open MRI examination can be used to evaluate the dynamic position of the posterior MM by scanning the knee as it flexes to 90°.
IV: retrospective cohort study.
Immune thrombocytopenic purpura (ITP) is an autoimmune disease primarily caused by IgG anti-platelet autoantibodies. Activation of autoreactive CD4(+) T cells upon recognition of cryptic GPIIb/IIIa ...peptides presented by antigen-presenting cells (APCs) is a critical step for triggering and maintaining the pathogenic anti-platelet autoantibody response.
We investigated which APCs carry the cryptic peptides of GPIIb/IIIa that activate autoreactive CD4(+) T cells in ITP patients.
GPIIb/IIIa-reactive T-cell lines generated from ITP patients were cultured with autologous freshly isolated splenic macrophages, B cells or dendritic cells. To further investigate how the macrophages presented the antigenic GPIIb/IIIa peptides, we prepared macrophages from the peripheral blood monocytes of the same patients during remission.
Macrophages induced the proliferation of GPIIb/IIIa-reactive T-cell lines without an exogenous antigen, but B cells and dendritic cells required GPIIb/IIIa peptides to stimulate the T cells. Macrophages derived from peripheral blood during remission required an exogenous antigen to induce the GPIIb/IIIa-reactive T-cell line response, but could elicit a response without added antigen if they were preincubated with platelets from ITP patients with platelet-associated anti-GPIIb/IIIa antibodies or healthy platelets pretreated with ITP platelet eluates. The T-cell response was inhibited by anti-FcgammaRI antibody. Finally, cultured macrophages that captured opsonized platelets promoted anti-GPIIb/IIIa antibody production in mixed cultures of autologous GPIIb/IIIa-reactive T-cell lines and B cells.
Splenic macrophages that take up opsonized platelets via FcgammaRI are major APCs for cryptic GPIIb/IIIa peptides, and are central to the maintenance of anti-platelet autoantibody production in ITP patients.
A micromechanical resonator embedded with a nanomechanical resonator is developed whose dynamics can be captured by the coupled-Van der Pol–Duffing equations. Activating the nanomechanical resonator ...can dispersively shift the micromechanical resonance by more than 100 times its bandwidth and concurrently increase its energy dissipation rate to the point where it can even be deactivated. The coupled-Van der Pol–Duffing equations also suggest the possibility of self-oscillations. In the limit of strong excitation for the nanomechanical resonator, the dissipation in the micromechanical resonator can not only be reduced, resulting in a quality factor of >3× 106, it can even be eliminated entirely resulting in the micromechanical resonator spontaneously vibrating.
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