The herbicide glyphosate, N-(phosphonomethyl) glycine, has been used extensively in the past 40years, under the assumption that side effects were minimal. However, in recent years, concerns have ...increased worldwide about the potential wide ranging direct and indirect health effects of the large scale use of glyphosate. In 2015, the World Health Organization reclassified glyphosate as probably carcinogenic to humans. A detailed overview is given of the scientific literature on the movement and residues of glyphosate and its breakdown product aminomethyl phosphonic acid (AMPA) in soil and water, their toxicity to macro- and microorganisms, their effects on microbial compositions and potential indirect effects on plant, animal and human health. Although the acute toxic effects of glyphosate and AMPA on mammals are low, there are animal data raising the possibility of health effects associated with chronic, ultra-low doses related to accumulation of these compounds in the environment. Intensive glyphosate use has led to the selection of glyphosate-resistant weeds and microorganisms. Shifts in microbial compositions due to selective pressure by glyphosate may have contributed to the proliferation of plant and animal pathogens. Research on a link between glyphosate and antibiotic resistance is still scarce but we hypothesize that the selection pressure for glyphosate-resistance in bacteria could lead to shifts in microbiome composition and increases in antibiotic resistance to clinically important antimicrobial agents. We recommend interdisciplinary research on the associations between low level chronic glyphosate exposure, distortions in microbial communities, expansion of antibiotic resistance and the emergence of animal, human and plant diseases. Independent research is needed to revisit the tolerance thresholds for glyphosate residues in water, food and animal feed taking all possible health risks into account.
Sources:
Antibiotic resistance papers: Cantas et al., 2013
Glyphosate use (relative area sprayed): USDA NASS, 2014. Display omitted
•Glyphosate and its degradation product AMPA have accumulated in the environment.•Chronic low dose effects on animals and humans have been documented recently.•Shifts in microbial community composition in soil, plants and animal guts resulted.•Glyphosate and antibiotic resistance have arisen in fungi and bacteria in parallel.•Glyphosate may serve as one of the drivers for antibiotic resistance.
Summary
The population-based cohort study used the Korean National Health Insurance claims database to evaluate the effect of anti-diabetic drugs on osteoporosis. The use of DPP-IV inhibitors does ...not increase the risk of osteoporosis compared with the use of sulfonylureas in patients with type 2 diabetes mellitus, while a weak association was found between thiazolidinediones and increased risk of osteoporosis.
Purpose
The current study aimed to evaluate the effect of dipeptidyl peptidase IV inhibitors (DPP-IVi), thiazolidinedione (TZD), and sulfonylurea (SU) on osteoporosis in patients with type 2 diabetes.
Methods
A population-based cohort study was conducted in the Republic of Korea using the Korean National Health Insurance claims database. Data from 2012 to 2017 for patients of 50–99 years of age who were prescribed DPP-IVi, TZD, or SU during 2013–2015 were extracted from the database. Based on pre-defined criteria, a total of 381,404 patients were analyzed after inverse probability of treatment weighting. The association between the study drugs and osteoporosis was estimated using Cox proportional hazards models. Data of 220,166 patients who were prescribed DPP-IVi, 18,630 who were prescribed TZD, and 142,608 patients who were prescribed SU were set.
Results
In the multivariate-adjusted analysis, the hazard ratio (HR) of osteoporosis in the DPP-IVi group was not significantly different from that of the SU group (HR: 0.97; 95% confidence interval (CI) 0.94–1.00), whereas the HR of osteoporosis in the TZD group was higher (HR: 1.13; 95% CI 1.06–1.20). In the subgroup analysis, the HRs of osteoporosis were higher with pioglitazone (HR: 1.14; 95% CI 1.06–1.23) in the TZD group and with glibenclamides (HR: 1.39; 95% CI 1.09–1.77) in the SU group, whereas drugs with lower HR in the DPP-IVi group were saxagliptin (HR: 0.93; 95% CI 0.87–0.99) and sitagliptin (HR: 0.93; 95% CI 0.89–0.97).
Conclusion
DPP-IV inhibitors do not increase the risk of osteoporosis compared with sulfonylureas in patients with type 2 diabetes mellitus, while a weak association was found between thiazolidinediones and increased risk of osteoporosis.
Pulp capping, or placing dental materials directly onto the vital pulp tissues of affected teeth, is a dental procedure that aims to regenerate reparative dentin. Several pulp capping materials are ...clinically being used, and calcium ion (Ca2+) released from these materials is known to mediate reparative dentin formation. ORAI1 is an essential pore subunit of store-operated Ca2+ entry (SOCE), which is a major Ca2+ influx pathway in most nonexcitable cells. Here, we evaluated the role of ORAI1 in mediating the odontogenic differentiation and mineralization of dental pulp stem cells (DPSCs). During the odontogenic differentiation of DPSCs, the expression of ORAI1 increased in a time-dependent manner. DPSCs knocked down with ORAI1 shRNA (DPSC/ORAI1sh) or overexpressed with dominant negative mutant ORAI1E106Q (DPSC/E106Q) exhibited the inhibition of Ca2+ influx and suppression of odontogenic differentiation and mineralization as demonstrated by alkaline phosphatase (ALP) activity/staining as well as alizarin red S staining when compared with DPSCs of their respective control groups (DPSC/CTLsh and DPSC/CTL). The gene expression for odontogenic differentiation markers such as osteocalcin, bone sialoprotein, and dentin matrix protein 1 (DMP1) was also suppressed. When DPSC/CTL or DPSC/E106Q cells were subcutaneously transplanted into nude mice, DPSC/CTL cells induced mineralized tissue formation with significant increases in ALP and DMP1 staining in vivo, whereas DPSC/E106Q cells did not. Collectively, our data showed that ORAI1 plays critical roles in the odontogenic differentiation and mineralization of DPSCs by regulating Ca2+ influx and that ORAI1 may be a therapeutic target to enhance reparative dentin formation.
Detailed dielectric measurements are reported for polycrystalline (
NH
4
)
3
H(
SO
4
)
2
at temperatures 10 K
<
T
<
100 K and frequencies 20 Hz
<
ν
<
3 MHz. Instead of the ferroelectric phase ...transition expected at 63 K, a typical dipole glass transition was observed at around 60 K. The frequency dependence of the complex dielectric permeability at
T
<
50 K was well described by a sum of two Cole–Cole functions. One of the two relaxators provides a background contribution to the dielectric dispersion. The most probable relaxation time for the main relaxator was best fitted to the modified Arrhenius law with
τ
0
=
3.5
×
10
-
13
s,
E
=
50
K
γ
, and
γ
=
0.37
.
Abstract
The object FRB 20180916B is a well-studied repeating fast radio burst source. Its proximity (∼150 Mpc), along with detailed studies of the bursts, has revealed many clues about its nature, ...including a 16.3 day periodicity in its activity. Here we report on the detection of 18 bursts using LOFAR at 110–188 MHz, by far the lowest-frequency detections of any FRB to date. Some bursts are seen down to the lowest observed frequency of 110 MHz, suggesting that their spectra extend even lower. These observations provide an order-of-magnitude stronger constraint on the optical depth due to free–free absorption in the source’s local environment. The absence of circular polarization and nearly flat polarization angle curves are consistent with burst properties seen at 300–1700 MHz. Compared with higher frequencies, the larger burst widths (∼40–160 ms at 150 MHz) and lower linear polarization fractions are likely due to scattering. We find ∼2–3 rad m
−2
variations in the Faraday rotation measure that may be correlated with the activity cycle of the source. We compare the LOFAR burst arrival times to those of 38 previously published and 22 newly detected bursts from the uGMRT (200–450 MHz) and CHIME/FRB (400–800 MHz). Simultaneous observations show five CHIME/FRB bursts when no emission is detected by LOFAR. We find that the burst activity is systematically delayed toward lower frequencies by about 3 days from 600 to 150 MHz. We discuss these results in the context of a model in which FRB 20180916B is an interacting binary system featuring a neutron star and high-mass stellar companion.
This study investigated the effect of 3D lattice models (D3Q19 and D3Q27 lattices) on the simulation results of wall-bounded turbulent flows in a circular pipe and in a square duct. The LES with the ...Smagorinsky subgrid-scale (SGS) model was adopted for the turbulence simulation. To improve the credibility of our results on the lattice model effect, a comprehensive sensitivity study was performed of boundary treatment techniques and collision models, as well as grid sizes in the simulation of the turbulent pipe flows. Through the turbulent circular pipe flow simulation, it was discovered that the D3Q27 lattice model could achieve the rotational invariance in terms of long-time-averaged turbulence statistics and generated the results comparable to the DNS data, while the D3Q19 lattice model broke the rotational invariance and produced unreasonable data. In the turbulent square duct flow simulation, the rotational invariance was evaluated by comparing the results before and after rotating the geometry by 45° about a center. As in the circular pipe flow simulation, the D3Q19 lattice model could not achieve the rotational invariance while the D3Q27 lattice model could. The D3Q19 lattice model also produced poor results compared to those from the D3Q27 lattice model. These defects of the D3Q19 lattice model could be explained by the planes consisting of 2D lattices with five velocities (called defective planes in this study) in the D3Q19 lattice model, based on White and Chong’s 14 hypothesis. The defective planes had a deficiency in the momentum transfer of flow and turbulence, thus breaking the rotational invariance and causing the inaccurate results for tested problems.
The age-hardening response and microstructural variation Mg–Zn and Mg–Zn–Al alloys were examined by hardness test, transmission electron microscopy (TEM) and three-dimensional atom probe. The samples ...were prepared by hot-extrusion after casting. The two-step aged samples exhibit enhanced age-hardening response at an earlier stage compared to the single-aged ones. TEM observations exhibited that the peak aged Mg–Zn samples had two kinds of precipitates: one was a rod along the
c-axis of the matrix phase; the other was a plate lying on the basal plane. The Mg–Zn–Al samples had rods and cuboidal precipitates. After two-step aging, the microstructure becomes finer for both the Mg–Zn and Mg–Zn–Al alloys. The rod-like precipitates were dominant in the peak aged Mg–Zn alloy, while the comparable number of rods and cuboidal precipitates were present in the Mg–Zn–Al alloy. Atom probe analyses for the samples pre-aged at 70
°C clearly showed the formation of Zn-rich zones.
This paper reviews key issues in the physical and numerical modelling of marine renewable energy systems, including wave energy devices, current turbines, and offshore wind turbines. The paper starts ...with an overview of the types of devices considered, and introduces some key studies in marine renewable energy modelling research. The development of new International Towing Tank Conference (ITTC) guidelines for model testing these devices is placed in the context of guidelines developed or under development by other international bodies as well as via research projects. Some particular challenges are introduced in the experimental and numerical modelling and testing of these devices, including the simulation of Power-Take-Off systems (PTOs) for physical models of all devices, approaches for numerical modelling of devices, and the correct modelling of wind load on offshore wind turbines. Finally, issues related to the uncertainty in performance prediction from model test results are discussed.The paper is based on the report of the International Towing Tank Conference specialist committee on Hydrodynamic Modelling of Marine Renewable Energy Devices to the 27th ITTC held in Copenhagen, Denmark in 2014 (ITTC Specialist Committee on Hydrodynamic Modelling of Marine Renewable Energy Devices, 2014a. Final Report and Recommendations to the 27th ITTC Proc. 27th International Towing Tank Conference, Copehagen, Denmark, vol. 2, pp. 680–725).
•We review techniques for hydrodynamic modelling of marine renewable energy devices.•We discuss new guidelines for model testing of marine renewable devices.•We introduce challenges for simulation of Power Take Off systems.•We discuss issues in simulating wind load in model tests of offshore wind turbines.•We address uncertainty of performance prediction in marine renewable device testing.
While there are persistent calls for developing more marine protected areas (MPAs) for Asian horseshoe crab conservation in response to population declines in Asia–Pacific region, most existing ...horseshoe crab MPAs were designated without prior comprehensive population assessment and habitat characterization. This study collected biological and habitat information in Hong Kong, in order to identify priority sites for conservation and management of Asian horseshoe crab populations. The territory-wide surveys at 18 spawning/nursery beaches displayed a persistently low mean juvenile density from 0.16 to 2.19 ind/100 m² in 2012 and 0.08 to 1.41 ind/100 m² in 2014. These density data were within the same range of that in 2002 and 2007 (0.10–1.97 ind/100 m²), apart from a low survey return of 0.08–0.31 ind/100 m² in 2004. The current population of juvenile T. tridentatus and C. rotundicauda in Hong Kong is estimated about 2100–4300 and 2400–3000 individuals, respectively. From the 2012–2014 data, no new recruitments of 1st–3rd instar juveniles were found, as the shores were occupied mostly by 6th–9th instar juveniles of prosomal width between 23 and 45 mm, in which considerably high mortality rates were noted. The present findings of existing small and discrete juvenile populations, coupled with relatively few recruits, suggest that the status of juvenile horseshoe crabs in Hong Kong is fragile and vulnerable to local extirpation, especially if no urgent protection measures are implemented. Based on available population data and habitat characteristics, three MPAs, ranging from 5 to 7 km², are proposed, so as to conserve over 60 and 70 % of the existing juvenile populations of T. tridentatus and C. rotundicauda, respectively. The approach adopted in this study may serve as a case study for proposing other horseshoe crab MPAs in Asia, where increasing human disturbances and over-harvest are imminent.
PDF
