Individuals Wearing Cleats Transitioning from Sitting to Standing Demonstrate a Significant Decrease in Blood Flow to the Foot

Plantar fasciopathy is a common foot condition with 10% prevalence in the general population. Plantar fasciosis (a type of fasciopathy) is considered a degenerative condition associated with cell death due to a lack of blood flow. Narrow, tight footwear, such as cleats, have been implicated as a potential contributing factors for the development of plantar fasciopathy and their direct influence on blood flow to the foot is currently unknown. PURPOSE: To investigate blood flow change in the anterior and posterior tibial arteries between sitting and standing in a cleated foot. METHODS: Eight individuals participated in this pilot study (weight=70.5 kg±12.9, height=1.8m±0.17). The participant put cleats on both feet, with a perceived tightness of 5/10 or greater on a VAS scale. Blood flow volume measurements of the anterior and posterior tibial arteries were taken simultaneously using pulse wave ultrasound, while the participant sat on a platform. These measurements were then repeated in the standing position on the same platform. Blood flow was measured in the dominate shod foot. A paired t-test was used to compare sitting to standing conditions within participants. RESULTS: In the anterior tibial artery, average volume flow changed from 6.25 ml/min (sitting) to 2.6 ml/min (standing), a 58% drop in blood flow (p=0.09). In the posterior tibial artery, volume flow decreased from an average of 11.25 ml/min to 3.95 ml/min, a decrease of 65% (p\u3c0.05). Total reduced blood flow between the two arteries decreased from 8.75 ml/min to 3.28 ml/min, a 63% drop (p\u3c0.05). CONCLUSION: There appears to be an important alteration of blood flow to the foot in individuals wearing cleats as they transition from a sitting to standing position. If this decrease in blood flow were to persist while wearing cleats, it may help explain the development of plantar fasciopathy observed in individuals wearing narrow, tight footwear

Stability of corn (\u3ci\u3eZea mays\u3c/i\u3e)- foxtail (\u3ci\u3eSetaria\u3c/i\u3e spp.) interference relationships

Variation in interference relationships have been shown for a number of crop-weed associations and may have an important effect on the implementation of decision support systems for weed management. Multiyear field experiments were conducted at eight locations to determine the stability of corn-foxtail interference relationships across years and locations. Two coefficients (I and A) of a rectangular hyperbola equation were estimated for each data set using nonlinear regression procedures. The I and A coefficients represent percent corn yield loss as foxtail density approaches zero and maximum percent corn yield loss, respectively. The coefficient I was stable across years at two locations and varied across years at four locations. Maximum yield loss (A) varied between years at one location. Both coefficients varied among locations. Although 3 to 4 foxtail plants m-1 row was a conservative estimate of the single-year economic threshold (Te) of foxtail density, variation in I and A resulted in a large variation in Te. Therefore, the utility of using common coefficient estimates to predict future crop yield loss from foxtail interference between years or among locations within a region is limited

Stability of corn (\u3ci\u3eZea mays\u3c/i\u3e)- foxtail (\u3ci\u3eSetaria\u3c/i\u3e spp.) interference relationships

Variation in interference relationships have been shown for a number of crop-weed associations and may have an important effect on the implementation of decision support systems for weed management. Multiyear field experiments were conducted at eight locations to determine the stability of corn-foxtail interference relationships across years and locations. Two coefficients (I and A) of a rectangular hyperbola equation were estimated for each data set using nonlinear regression procedures. The I and A coefficients represent percent corn yield loss as foxtail density approaches zero and maximum percent corn yield loss, respectively. The coefficient I was stable across years at two locations and varied across years at four locations. Maximum yield loss (A) varied between years at one location. Both coefficients varied among locations. Although 3 to 4 foxtail plants m-1 row was a conservative estimate of the single-year economic threshold (Te) of foxtail density, variation in I and A resulted in a large variation in Te. Therefore, the utility of using common coefficient estimates to predict future crop yield loss from foxtail interference between years or among locations within a region is limited

Stability of Corn (Zea mays)-Velvetleaf (Abutilon theophrasti) Interference Relationships

The crop-weed interference relationship is a critical component of bioeconomic weed management models. Multi-year field experiments were conducted at five locations to determine the stability of corn-velvetleaf interference relationships across years and locations. Two coefficients (I and A) of a hyperbolic equation were estimated for each data set using nonlinear regression procedures. The I and A coefficients represent percent corn yield loss as velvetleaf density approaches zero, and maximum percent corn yield loss, respectively. The coefficient I was stable across years at two locations, but varied across years at one location. The coefficient A did not vary across years within locations. Both coefficients, however, varied among locations. Results do not support the use of common coefficient estimates for all locations within a region

Revolutionary Effects of New Information Technologies

In markets with imperfect information and heterogeneity, the information technology affects the rate at which agents meet, which affects the distribution of production technologies across firms. Multiple equilibria may arise because the reservation utility and the lowest production technology in use affect each other. The adoption of novel information technologies may then entail a revolution in the sense of a move from an inefficient to an efficient equilibrium. Inefficient production technologies are swiftly removed even in sectors where the new information technology has only recently been introduced. The results apply to consumer products, labour, intermediates and institutions. Copyright 2006 Royal Economic Society.