Money handling influences BMI: a survey of cashiers

Money is a recent phenomenon in the evolutionary history of man and therefore no separate brain centre to handle money is likely to have evolved. The brain areas activated by food reward and money reward are extensively overlapping. In an experimental set-up, hunger was demonstrated to influence money related decisions and money related thoughts to influence hunger. This suggests that the brain areas evolved for handling food related emotions are exapted to handle money and therefore there could be a neuronal cross-talk between food and money. If this is true then attitude and behavior related to money and wealth could influence obesity. We conducted a survey of 211 individuals working as full time cashiers in order to test whether ownership over the cash, the amount of cash handled per day and the duration of cash handling work affected their body mass index (BMI). Cashiers who had ownership over the money had a significantly higher age corrected mean BMI than salaried cashiers. The BMI correlated positively with duration of service as cashier even after correcting for age and duration of sedentary job in males. Among salaried cashiers of both sexes, bank cashiers whose mean daily cash handling was one or two orders of magnitude greater than that of shop cashiers, had a significantly higher BMI. The effects of amount of money handled per day, years of service as cashier and ownership over the money handled could be shown to influence BMI independent of each other. The results support the exaptation hypothesis and suggest that the changing economy and attitudes towards money may be a contributing factor to the current obesity epidemic

North American boreal forests are a large carbon source due to wildfires from 1986 to 2016

Wildfires are a major disturbance to forest carbon (C) balance through both immediate combustion emissions and post-fire ecosystem dynamics. Here we used a process-based biogeochemistry model, the Terrestrial Ecosystem Model (TEM), to simulate C budget in Alaska and Canada during 1986-2016, as impacted by fire disturbances. We extracted the data of difference Normalized Burn Ratio (dNBR) for fires from Landsat TM/ETM imagery and estimated the proportion of vegetation and soil C combustion. We observed that the region was a C source of 2.74 Pg C during the 31-year period. The observed C loss, 57.1 Tg C year(-1), was attributed to fire emissions, overwhelming the net ecosystem production (1.9 Tg C year(-1)) in the region. Our simulated direct emissions for Alaska and Canada are within the range of field measurements and other model estimates. As burn severity increased, combustion emission tended to switch from vegetation origin towards soil origin. When dNBR is below 300, fires increase soil temperature and decrease soil moisture and thus, enhance soil respiration. However, the post-fire soil respiration decreases for moderate or high burn severity. The proportion of post-fire soil emission in total emissions increased with burn severity. Net nitrogen mineralization gradually recovered after fire, enhancing net primary production. Net ecosystem production recovered fast under higher burn severities. The impact of fire disturbance on the C balance of northern ecosystems and the associated uncertainties can be better characterized with long-term, prior-, during- and post-disturbance data across the geospatial spectrum. Our findings suggest that the regional source of carbon to the atmosphere will persist if the observed forest wildfire occurrence and severity continues into the future.Peer reviewe

Impact of RoCE Congestion Control Policies on Distributed Training of DNNs

RDMA over Converged Ethernet (RoCE) has gained significant attraction for datacenter networks due to its compatibility with conventional Ethernet-based fabric. However, the RDMA protocol is efficient only on (nearly) lossless networks, emphasizing the vital role of congestion control on RoCE networks. Unfortunately, the native RoCE congestion control scheme, based on Priority Flow Control (PFC), suffers from many drawbacks such as unfairness, head-of-line-blocking, and deadlock. Therefore, in recent years many schemes have been proposed to provide additional congestion control for RoCE networks to minimize PFC drawbacks. However, these schemes are proposed for general datacenter environments. In contrast to the general datacenters that are built using commodity hardware and run general-purpose workloads, high-performance distributed training platforms deploy high-end accelerators and network components and exclusively run training workloads using collectives (All-Reduce, All-To-All) communication libraries for communication. Furthermore, these platforms usually have a private network, separating their communication traffic from the rest of the datacenter traffic. Scalable topology-aware collective algorithms are inherently designed to avoid incast patterns and balance traffic optimally. These distinct features necessitate revisiting previously proposed congestion control schemes for general-purpose datacenter environments. In this paper, we thoroughly analyze some of the SOTA RoCE congestion control schemes vs. PFC when running on distributed training platforms. Our results indicate that previously proposed RoCE congestion control schemes have little impact on the end-to-end performance of training workloads, motivating the necessity of designing an optimized, yet low-overhead, congestion control scheme based on the characteristics of distributed training platforms and workloads

IMECE2002-32487 AN ANTHROPOMETRIC ARM FOR THE HUMANOID ROBOT: DESIGN AND ANALYSIS OF THE TYCHE-ARM

Abstract: This paper is concerned with the development of an anthropometric robot arm for the humanoid robotTyche. The design was based on physiology and anthropometry of the human arm. The Tyche-arm uses a skew-pantograph mechanism, as the control device, that helps in magnifying the input. The link lengths of the structure are determined based on topological studies and avoidance of the singularity condition. A fault tolerant design for the linear actuator is incorporated in the design. The kinematic and dynamic analyses of the Tyche-arm are performed on the weight lifting activity, with the upper arm fixed in five different positions. The kinematic parameters, axial forces in the links and the torques for each joint are obtained and plotted with respect to time

Rising methane emissions from boreal lakes due to increasing ice-free days

Lakes account for about 10% of the boreal landscape and are responsible for approximately 30% of biogenic methane emissions that have been found to increase under changing climate. However, the quantification of this climate-sensitive methane source is fraught with large uncertainty under warming climate conditions. Only a few studies have addressed the mechanism of climate impact on the increase of northern lake methane emissions. This study uses a large observational dataset of lake methane concentrations in Finland to constrain methane emissions with an extant process-based lake biogeochemical model. We found that the total current diffusive emission from Finnish lakes is 0.12 +/- 0.03 Tg CH4 yr(-1) and will increase by 26%-59% by the end of this century depending on different warming scenarios. We discover that while warming lake water and sediment temperature plays an important role, the climate impact on ice-on periods is a key indicator of future emissions. We conclude that these boreal lakes remain a significant methane source under the warming climate within this century.peerReviewe

Nitrogen Addition Affects Nitrous Oxide Emissions of Rainfed Lucerne Grassland

Nitrous oxide (N2O) is a potent greenhouse gas. Assessing the N2O emission from lucerne grasslands with nitrogen addition will aid in estimating the annual N2O emissions of such agriculture areas, particularly following summer rainfall events in light of precipitation variation associated with global change. Here, we measured soil N2O emissions, soil temperature and water content of lucerne grasslands with four levels of nitrogen addition over 25 days, which included 10 rainfall events. Results showed that nitrogen addition was observed to increase soil NO3−-N content, but not significantly improve dry matter yield, height or leaf area index. Nitrogen addition and rainfall significantly affected N2O emissions, while the response of N2O emissions to increasing nitrogen input was not linear. Relative soil gas diffusivity (Dp/Do) and water-filled pore space (WFPS) were good indicators of N2O diurnal dynamics, and Dp/Do was able to explain slightly more of the variation in N2O emissions than WFPS. Collectively, nitrogen addition did not affect lucerne dry matter yield in a short term, while it induced soil N2O emissions when rainfall events alter soil water content, and Dp/Do could be a better proxy for predicting N2O emissions in rainfed lucerne grasslands