We study the relationship between urban sprawl and obesity. Using data that tracks individuals over time, we find no evidence that urban sprawl causes obesity. We show that previous findings of a positive relationship most likely reflect a failure to properly control for the fact the individuals who are more likely to be obese choose to live in more sprawling neighborhoods. Our results indicate that current interest in changing the built environment to counter the rise in obesity is misguided.

A possible mechanism of varicocele-induced infertility is believed to be elevation of testicular temperature. Sensitive needle thermistors were used to measure directly intratesticular and bilateral scrotal surface temperatures simultaneously in anesthetized infertile men with varicocele and control subjects. We found that intratesticular temperature is elevated significantly in humans with varicocele. In addition, we have shown that scrotal skin surface temperature is elevated in men with varicocele. Furthermore, we demonstrate that unilateral varicocele is associated with bilateral elevation of scrotal surface temperature. These findings confirm the results of animal studies revealing elevation of intratesticular temperature associated with varicocele and suggest bilateral elevation in unilateral varicocele.

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