Labor and women's nutrition : a study of energy expenditure, fertility, and nutritional status in Ghana

Economic approaches to health and nutrition have focused largely on measures of child nutrition and related variables (such as birth weight) as indicators of household production of nutritional outcomes. But when dealing with adult nutrition, economists have to address an issue that has generated tremendous controversy in the clinical nutrition literature. That issue is heterogeneity in an individual's energy expenditures. Preschoolers'energy expenditure also differs, but the differences are small enough to be ignored. Not so for adults, whose waking hours are devoted mostly to labor activities of which the energy costs vary enormously. Variables measuring time allocation to various types of labor tasks were used to proxy differences in energy expenditure. Parity has also been hypothesized to be an important determinant of female nutritional health in high fertility countries - with rapid reproductive cycling contributing to a cumulative nutritional decline. But the"maternal depletion syndrome"remains controversial. Much of the evidence to date has been impressionistic - or the results of studies based on small, nonrandom cohorts. Higgins and Alderman used a two-step instrumental variables technique to get consistent estimates of the structural parameters. Energy expenditure, as embodied in individual time allocations over the previous seven days, was found to be an important determinant of women's nutritional status. Time devoted to agricultural tasks, in particular, had a strong negative effect. The results also appear to confirm the existence of a maternal depletion syndrome. Perhaps more important, evidence was found of a substantial downward bias of the calorie-elasticity estimate when the energy expenditure proxies were excluded.Health Monitoring&Evaluation,Health Economics&Finance,Agricultural Knowledge&Information Systems,Environmental Economics&Policies,Economic Theory&Research

Millimeter-wave communication for a last-mile autonomous transport vehicle

Low-speed autonomous transport of passengers and goods is expected to have a strong, positive impact on the reliability and ease of travelling. Various advanced functions of the involved vehicles rely on the wireless exchange of information with other vehicles and the roadside infrastructure, thereby benefitting from the low latency and high throughput characteristics that 5G technology has to offer. This work presents an investigation of 5G millimeter-wave communication links for a low-speed autonomous vehicle, focusing on the effects of the antenna positions on both the received signal quality and the link performance. It is observed that the excess loss for communication with roadside infrastructure in front of the vehicle is nearly half-power beam width independent, and the increase of the root mean square delay spread plays a minor role in the resulting signal quality, as the absolute times are considerably shorter than the typical duration of 5G New Radio symbols. Near certain threshold levels, a reduction of the received power affects the link performance through an increased error vector magnitude of the received signal, and subsequent decrease of the achieved data throughput

Assessment of body composition by air-displacement plethysmography: influence of body temperature and moisture

BACKGROUND: To investigate the effect of body temperature and moisture on body fat (%fat), volume and density by air-displacement plethysmography (BOD POD). METHODS: %fat, body volume and density by the BOD POD before (BOD POD(BH)) and immediately following hydrostatic weighing (BOD POD(FH)) were performed in 32 healthy females (age (yr) 33 ± 11, weight (kg) 64 ± 14, height (cm) 167 ± 7). Body temperature and moisture were measured prior to BOD POD(BH )and prior to BOD POD(FH )with body moisture defined as the difference in body weight (kg) between the BOD POD(BH )and BOD POD(FH )measurements. RESULTS: BOD POD(FH )%fat (27.1%) and body volume (61.5 L) were significantly lower (P ≤ 0.001) and body density (1.0379 g/cm(3)) significantly higher (P ≤ 0.001) than BOD POD(BH )%fat (28.9%), body volume (61.7 L), and body density (1.0341 g/cm(3)). A significant increase in body temperature (~0.6°C; P ≤ 0.001) and body moisture (0.08 kg; P ≤ 0.01) were observed between BOD POD(BH )and BOD POD(FH). Body surface area was positively associated with the difference in %fat independent of changes in body temperature and moisture, r = 0.30, P < 0.05. CONCLUSION: These data demonstrate for the first time that increases in body heat and moisture result in an underestimation of body fat when using the BOD POD, however, the precise mechanism remains unidentified

The Value of Bt Corn in Southwest Kansas: A Monte Carlo Simulation Approach

While most Corn Belt farmers consider planting Bt corn to control European corn borer, southwestern Kansas farmers must also take into account an array of other insect pests, including corn rootworm, spider mites, and southwestern corn borer. This research uses a decision analysis framework to estimate the expected economic value of Bt corn in southwest Kansas. Mean per acre Bt values ranged from $12.49 to$34.60, well above the technology fee assumed to be $14 per unit, or$5.25 per acre at a seeding rate of 30,000 seeds per acre. The minimum value over all scenarios was $8.69 per acre. Using Monte Carlo simulation, it was shown that European and southwestern corn borer infestation probabilities, expected corn price, and expected pest-free yields are important determinants of the value of Bt corn.Bt corn, decision analysis, European corn borer, integrated pest management, Monte Carlo simulation, southwestern corn borer, Crop Production/Industries,

A grid-based coverage analysis of urban mmWave vehicular ad hoc networks

In this letter, a tractable coverage model, specifically designed for urban vehicular ad hoc networks, is presented to aid a better system designer. This is achieved through the use of a model based upon line processes, which simplifies the analysis. It is found, that even in crowded interferer scenarios, mmWave vehicular communications can establish reliable links with an SINR threshold of around 5 dB, with a coverage probability of approximately 0.8 at 50 m separation between a typical transmitter and a typical receiver. These results, and their inference towards the design and deployment of urban vehicular ad-hoc networks, may impact the developments of future vehicle- to-vehicle (V2V) applications and services

Traffic simulation of connected and autonomous freight vehicles to increase traffic throughput via road tunnel networks

This paper simulates traffic at the Dartford-Thurrock Crossing Tunnel, Kent, UK. Using a traffic simulation model, Connected and Autonomous Freight Vehicles (CAV-F) are simulated alongside conventional light goods vehicles, to determine the feasibility of increasing the traffic throughput at the tunnel. The results show that with the use of CAV-F, the overall traffic flow is increased by --33% from current flow of --5,000 vehicles/hr. With the reduction in the headway and standstill distance and increase in scope of intelligent connectivity and traffic speed limit, the average congestion and travel time are reduced even at a higher traffic concentration. By analysing the results, it has thus been possible to highlight the benefits to traffic management and road utilisation by introducing CAV-F into our road network, in the long term