Ambient vibration tests and analysis of a multiple-span elevated bridge

Peer reviewed

Forced and ambient vibration testing of full scale bridges : Project No. UNI/578

Preprint

Type 2 diabetes, but not obesity, prevalence is positively associated with ambient temperature

Acknowledgements This study was supported by the Strategic Priority Research Program of the Chinese Academy of Sciences (XDB13030000), the National Science foundation of China (microevolution program NSFC91431102) and the 1000 talents program. We are grateful to members of the Molecular Energetics group in Beijing and the Energetics group in Aberdeen, UK for valuable discussion of the data and analysis. All data analysed in this paper are already available in the public domain.

The role of acute ambient hypoxia in the regulation of myostatin

When exposed to chronic hypoxia by pathophysiological or environmental causes humans show muscle atrophy, challenging homeostasis and increasing mortality rate. Chronic hypoxia also presents with elevated myostatin peptide, a negative regulator of muscle size. This work induced acute hypoxia in healthy individuals; hypothesizing hypoxia would increase myostatin expression in both muscle and plasma in a concentration- and time-dependent manner. Hypoxia (1 % O2) reduced C2C12 myoblast migration and myotube size in vitro. Myotube atrophy was time-dependent, longer exposures showed greater atrophy. Intracellular myostatin peptide was decreased at every time point measured. Myostatin and downstream signalling pathways in muscle showed a high degree of percentage similarity between mouse and human, when amino acid sequences were directly compared. Healthy males (N = 8) were exposed to 20.9 % O2 or 11.9 % O2 for 2 hours. Following hypoxic exposure myostatin peptide was reduced in muscle but not plasma, relative to control conditions. A second cohort (N = 8) was exposed to 12.5 % O2 for 10 hours. Plasma myostatin was decreased following hypoxia, muscle myostatin trended towards increasing. A third cohort (N = 9; n = 8 lowlander, n = 1 Sherpa) was exposed to 10.7 % or 12.3 % O2 for 2 hours. Plasma myostatin was reduced at both concentrations with no difference between concentrations noted. In response to chronic hypoxia, individuals lose muscle mass. Counter to the hypothesis of an increase in myostatin in both muscle and plasma, here a consistent decrease in plasma myostatin following acute hypoxia is seen. Muscle myostatin shows a variable response, with decreasing intracellular expression seen following a 2 hour hypoxic exposure, and trends towards an increase following 10 hours of hypoxia. Decreases in plasma and muscle myostatin may represent myostatin’s movement towards peripheral compartments in these acute timeframes. Hypoxia alone is capable of altering myostatin in healthy individuals; the effects of hypoxia on myostatin appear to differ between the acute timeframes examined here and chronic exposures in environmental or disease models.

Increasing Ambient Temperature Reduces Emotional Well-Being

This study examines the impact of ambient temperature on emotional well-being in the U.S. population aged 18+. The U.S. is an interesting test case because of its resources, technology and variation in climate across different areas, which also allows us to examine whether adaptation to different climates could weaken or even eliminate the impact of heat on well-being. Using survey responses from 1.9 million Americans over the period from 2008 to 2013, we estimate the effect of temperature on well-being from exogenous day-to-day temperature variation within respondents’ area of residence and test whether this effect varies across areas with different climates. We find that increasing temperatures significantly reduce well-being. Compared to average daily temperatures in the 50–60 °F (10–16 °C) range, temperatures above 70 °F (21 °C) reduce positive emotions (e.g. joy, happiness), increase negative emotions (e.g. stress, anger), and increase fatigue (feeling tired, low energy). These effects are particularly strong among less educated and older Americans. However, there is no consistent evidence that heat effects on well-being differ across areas with mild and hot summers, suggesting limited variation in heat adaptation.

The current and potential applications of Ambient Mass Spectrometry in detecting food fraud

The adulteration of food has received substantial amounts of media attention in the last few years, with events such as the European horsemeat scandal in 2013 sending shockwaves through society. Almost all cases are motivated by the pursuit of profits and are often aided by long and complex supply chains. In the past few years, the rapid growth of ambient mass spectrometry (AMS) has been remarkable, with over thirty different ambient ionisation techniques available. Due to the increasing concerns of the food industry and regulators worldwide, AMS is now being utilised to investigate whether or not it can generate results which are faster yet comparable to those of conventional techniques. This article reviews some aspects of the adulteration of food and its impact on the economy and the public's health, the background to ambient mass spectrometry and the studies that have been undertaken to detect food adulteration using this technology.

Descriptions of Water Quality Parameters for Lakes in the Ambient Lake Monitoring Program

This fact sheet summarizes the water quality data collected as part of the Iowa Department of Natural Resources ambient lake monitoring program.

Ambient Lake Monitoring Program Summary

Summary of sites and parameters monitored as part of the Iowa Department of Natural Resources lake monitoring program.

Upper crustal structure of Madeira Island revealed from ambient noise tomography

We present the first image of the Madeira upper crustal structure, using ambient seismic noise tomography. 16 months of ambient noise, recorded in a dense network of 26 seismometers deployed across Madeira, allowed reconstructing Rayleigh wave Green's functions between receivers. Dispersion analysis was performed in the short period band from 1.0 to 4.0 s. Group velocity measurements were regionalized to obtain 2D tomographic images, with a lateral resolution of 2.0 km in central Madeira. Afterwards, the dispersion curves, extracted from each cell of the 2D group velocity maps, were inverted as a function of depth to obtain a 3D shear wave velocity model of the upper crust, from the surface to a depth of 2.0 km. The obtained 3D velocity model reveals features throughout the island that correlates well with surface geology and island evolution.

Ambient stored garlic is higher yielding than garlic stored at cooler temperatures

This experiment evaluated the effect of storage temperature on garlic emergence and yield. Six treatments, '5°C + heat', '5°C - heat', '15°C + heat', '15°C - heat', 'ambient + heat' and 'ambient - heat' were imposed. The heat treatment included a stepped heat treatment of between 30 and 38°C over a 42 day period. Highest emergence rate and yield was obtained for treatments stored under ambient conditions. Garlic stored at cool temperatures of either 5 or 15°C had poorer emergence and lower yields that were commercially unviable. Heat treatment had no observable effect on emergence or yield in ambient or 15°C treatments but in 5°C treatments, yield was significantly greater when the heat treatment was applied but nonetheless was still commercially unviable. The recommendations from this experiment are that in subtropical climates garlic seed-bulbs should be stored under ambient conditions. © ISHS.

An ecosystem of products and systems for ambient intelligence – the AAL4ALL users perspective

Texto completo em atas de encontros científicos internacionais com arbitragem

Effect of ambient levels of ozone on photosynthetic components and radical scavenging system in leaves of African cowpea varieties

Tropospheric ozone (O3), a main component of photochemical oxidants, adversely affects not only human health but also vegetation. To clarify the long-term effects of ambient levels of tropospheric ozone (O3) on photosynthetic components and radical scavenging system in the leaves of cowpea ( Vigna unguiculata L.), two African varieties, Blackeye and Asontem, were grown in open-top chambers and exposed to filtered air (FA), non-filtered air (NF) or non-filtered air with additional O3 of approximately 50 nl l-1. Ambient levels of O3 significantly reduced chlorophyll concentration, quantum yield and activity of ribulose 1,5-bisphosphate carboxylase/oxygenase (Rubisco), thus contributing to the reduction in net photosynthetic rate at the reproductive growth stage of both varieties; with no significant variety difference in the sensitivity to O3. The O3-induced significant reduction in catalase activity was observed in Blackeye at vegetative and reproductive growth stages; and in Asontem at reproductive growth stage. On the other hand, exposure to O3 significantly increased ascorbate peroxidase activity in Blackeye at reproductive stage and did not significantly affect that in Blackeye at vegetative growth stage and that in Asontem at both growth stages. At reproductive growth stage, activities of monodehydroascorbate reductase and glutathione reductase were significantly increased by the exposure to O3 in both varieties. The results obtained in this study suggest that, although ascorbate peroxidase, monodehydroascorbate reductase and glutathione reductase played important roles in scavenging O3-induced reactive oxygen species in the leaves, radical scavenging ability of these enzymes is not sufficient to avoid detrimental effects of ambient levels of O3 on photosynthesis in both African cowpea varieties.

Ambient Air Quality Monitoring in Metropolitan City of Lagos, Nigeria

Twenty one sampling locations were assessed for carbon monoxide (CO), carbondioxide (CO2), oxygen (O2), sulphur dioxide (SO2), nitrogen dioxide (NO2), nitrogen oxide (NO), suspended particulate matter (SPM) and noise level using air pollutants measurement methods approved by ASTM for each specific parameter. All equipments and meters were all properly pre-calibrated before each usage for quality assurance. Findings of the study showed that measured levels of noise (61.4 - 101.4 dBA), NO (0.0 - 3.0 ppm), NO2 (0.0 - 3.0 ppm), CO (1.0 – 42.0 ppm) and SPM (0.14 – 4.82 ppm) in all sampling areas were quite high and above regulatory limits however there was no significant difference except in SPM (at all the sampling points), and noise, NO2 and NO (only in major traffic intersection). Air quality index (AQI) indicates that the ambient air can be described as poor for SPM, varied from good to very poor for CO, while NO and NO2 are very good except at major traffic intersection where they were both poor and very poor (D-E). The results suggest that strict and appropriate vehicle emission management, industrial air pollution control coupled with close burning management of wastes should be considered in the study area to reduce the risks associated with these pollutants.

On estimating attenuation from the amplitude of the spectrally whitened ambient seismic field

International audience