Optimal uptake kinetics: physiological acclimation explains the pattern of nitrate uptake by phytoplankton in the ocean

Phytoplankton supply the base of the marine food web and drive the biogeochemical cycles of carbon and nutrients. Over much of the ocean, their growth is limited by their uptake of nitrogen (as nitrate), which has most commonly been described by the hyperbolic Michaelis-Menten (MM) equation. However, the lack of a theory to explain variations in MM constants has hindered our ability to predict the response of marine ecosystems to changes in environmental conditions. The MM equation fits data from short-term experiments well, but does not agree with steady-state experiments over wide ranges of nutrient concentrations. In contrast, the recently developed optimal uptake kinetics (OU) does agree with the latter and can also describe the observed pattern of MM half-saturation constants from field. experiments. OU kinetics explains the observed pattern of N uptake as the result of a general physiological trade-off between nutrient uptake capacity and affinity. The existence of a general trade-off would imply a relatively high degree of predictability in the response of nutrient uptake to changing nutrient concentrations and thus provide a basis for predicting effects of climate change on marine ecosystems and biogeochemical cycles

Effect of crowning radius on rolling contact fatigue strength for traction drive elements

A simulation of the rolling contact fatigue strength of a traction drive element was developed. This simulation accounts for both the distribution of sizes of inclusions in the element material and the influence of traction forces at the element surface. The shear strength of the matrix structure surrounding an inclusion was estimated with an equation. The hardness distribution and the Weibull distribution of inclusion dimensions, which are necessary parameters to calculate the rolling contact fatigue strength, were determined by observation of an actual test specimen. The purpose of this report is simulations to evaluate the effect of the crowning radius on the rolling contact fatigue strength and the torque capacity. The simulations were carried out by varying the crowning radius of the virtual roller. To consider the effect of the crowning radius, a simulated two-dimensional virtual roller, which has actual material properties, was modified to a roller multilayered toward the axial direction. The simulation assuming the actual roller led to a difference of 1.0% from the experimental rolling contact fatigue strength. This difference was 2.4 points smaller than the result for the two-dimensional virtual roller. The rolling contact fatigue strength decreased with increasing crowning radius for two reasons. One was the increase in the number of inclusions under the high stress due to the increasing crowning radius. The other was the expansion of the portion of the roller subject to high stresses down to a depth having small hardness. However, the torque capacity calculated from the contact force resulting in failure increased with the increasing crowning radius

Simulation of rolling contact fatigue strength for traction drive elements (comparison with fatigue test)

A simulation of the rolling contact fatigue strength of a traction drive element was developed. This simulation accounts for both the distribution of sizes of inclusio s in the element material and the influence of traction forces at the element surface. The shear strength of the matrix structure surrounding an inclusion was estimated with an equation. The purpose of this report is verifying the estimation accuracy of this simulation by comparing with the experimental result. The experiment was carried out by according to the 14 S-N testing method. The material of test rollers was carburized JIS SCM420H. The hardness distribution and the Weibull distribution of inclusion dimensions, which are necessary parameters of this simulation, were determined by observation of an actual test specimen. The calculated rolling contact fatigue strength in failure rate of 50% at 107 cycles was 750 MPa with a standard deviation of 35.4 MPa. The rolling contact fatigue strength of 1120 MPa with a standard deviation of 50.8 MPa was obtained as a result of experiment. The failure mode was considered to be flaking from the internal origination. The calculated standard deviation was about equal to the experimental result. Though there was 370 MPa difference between calculated and experimental fatigue strength. Including of the hardening of roller and the influence of compressive residual stress in the simulation and the determination of the depth of failure initiation will decrease above error

Spreading of Antarctic Bottom Water examined using the CFC-11 distribution simulated by an eddy-resolving OGCM

We have investigated the spreading and pathway of Antarctic Bottom Water(AABW) using the simulated distribution of chlorofluorocarbons(CFCs) in a global eddy-resolving(1/10°) OGCM. Our goal is understanding of the processes and pathways determining the distribution of CFCs in the Southern Ocean, where much of this tracer is entrained by formation of deep and bottom water. The simu- lated high CFC-11 water reveals the newly formed AABW around the Antarctic Continent. The main source regions of AABW in the model are in the Weddell Sea(60°- 30°W ), offshore of Wilkes Land(120°- 160°E ) and in the Ross Sea(170°E -160°W ). In our model, spreading of simulated CFC-11 in the deep Southern Ocean from the newly formed AABW regions is more similar to the observed distribution than in coarse-resolution models. In the Weddell Sea, the high CFC-11 water spreads eastward with the Antarctic Circumpolar Current(ACC) and flows northward to the Argentine Basin. The high CFC-11 water from Wilkes Land joins with the high CFC-11 water from the Ross Sea. Some of the high CFC-11 water from Wilkes Land flows northward toward New Zealand. The high CFC-11 water from the Ross Sea flows eastward with the ACC along the Mid Ocean Ridge and northward to the Southeast Pacific Basin

Development of Safety Measures of Bicycle Trafflc by Observation wffh Deep-Leamlng, Drive Recorder Data, Probe Blcycle wlth LIDAR, and Connected Simulators

This research outlines the development of evaluating safety measures for bicycle traffic using state-of-the-art technology, which was started since 2020 as a four-year project. The project is funded by the Commission on Advanced Road Technology in the Ministry of Land, Infrastructure, Transport and Tourism(MLIT). While Japan has a high bicycle modal share of 12% (2010), bicycle-related fatalities are relatively high among other countries in the IRTAD database (2019). Under these circumstances, since 2007, various measures for bicycle traffic measures have been implemented to improve the safe bicycle traffic environment, including the revision of the Road Traffic Act and the formulation of a national plan to promote bicycle use. However, serious accidents involving bicycles are remained in some specific cases. According to the government's traffic accident analysis results (2019), right-hook crash at signalized intersections are one of the most serious types of collision involving bicycles, along with accidents at unsignalized intersections involving vehicles turning left, rear-end collisions, and single vehicle accidents due to off-road deviation. In particular, proactive safety measures are required at signalized intersections along arterial roads, where electric personal mobility vehicles traveling at speeds of up to 20 km/h are expected to share with bicycles in the future. In order to evaluate safety measures for bicycle-vehicle crashes, this project set the following goals. 1) Identify factors influencing near-miss incidents and collisions through analysis of drive recorder data and accident statistical data. 2) Detailed analysis of traffic conditions from the cyclist's perspective using a probe bicycle equipped with a LiDAR sensor. 3) Development of an experimental environment using a connected simulator for evaluation of cooperative driving behavior. 4) Clarification of experimental conditions to evaluate different scenarios and conditions with and without intervention. 5) Proposal of effective interventions to improve crash cases based on experiments

Clinical utility of silk-elastin sponge in patients with chronic and acute skin ulcers: study protocol of a multi-center clinical trial

INTRODUCTION: Not only chronic but also some acute wounds have a risk of infection and become unhealed wounds. Silk-elastin sponge has been developed to treat chronic wounds that are susceptible to infection. Preclinical and clinical studies suggested that silk-elastin sponge is safe for humans and can promote granulation tissue formation by reducing bacterial growth in chronic wounds. The central aim of this trial is to evaluate the clinical utility and safety of silk-elastin sponge for the treatment of chronic and acute skin ulcers. METHODS: This study is a prospective, multicenter, single-arm, uncontrolled clinical trial. In this study, 20 patients with chronic ulcers and five with an acute one will be included; patients with wound infection will be excluded. Silk-elastin sponges are applied and covered with a dressing for 14 days. PLANNED OUTCOMES: The primary endpoint is the frequency of patients with chronic wounds in whom the investigator confirms the formation of a healthy wound bed at 14 days after the initial application of the study device. In addition, safety for acute wounds and handiness of the study device will be assessed. TRIAL REGISTRATION NUMBER: jRCT2052210072