In explaining osmotic movement of water. it is customary in plant physiology to regard water movement between cells as taking place along gradients of diffusion pressure deficit or suction force. Efforts to describe water movement quantitatively are based on the assumption that the rate of water movement between two cells should be proportional to the difference between the diffusion pressure d...

INTRODUCTION A 45-year-old man presented with headache for two days. He described the quality of headache as throbbing, and it was unilateral. There was no history of fever, vomiting, blurred vision, ear discharge or trauma, no relevant past medical or drug history and no family history of note. On examination, he was afebrile with pulse 76/min, regular, blood pressure of 130/80mmHg. His pupils...

A9-year-old boy was shot with a pellet shotgun and developed a visual field deficit. Head CT revealed a pellet in the left ambien cistern, in the left posterior cerebral artery on catheter angiography (figure). Chest fluoroscopy revealed multiple thoracic pellets, including a mobile cardiac pellet (video on the Neurology® Web site at Neurology.org). There was no clear cardiac injury, patent for...

During exercise in the heat, sweat output often exceeds water intake, resulting in hypohydration, which is defined as a body fluid deficit. This fluid deficit is comprised of water loss from both the intracellular and extracellular fluid compartments. Hypohydration during exercise causes a greater heat storage and reduces endurance in comparison with euhydration levels. The greater heat storage...

We monitored sap flow and estimated diurnal changes in transpiration rates of two trembling aspen (Populus tremuloides Michx.) stands, located in the southern boreal forest and aspen parkland of Saskatchewan, Canada. In both stands during the peak growing season (June and July), sap flow during the day (0700-1700 h local time) increased linearly with vapor pressure deficit (VPD) from 0 to about...

Though the IEEE 802.11 standard has reached wide acceptance, its main access function, the Distributed Coordination Function (DCF), still suffers from some relevant problems coming from the specific features of the wireless channel. By means of simulation, we analyse the performance anomaly and the “inter-flow blocking” problems, highlighting the mechanisms that generate them. Starting from the...

Jt is now well established that myocardial dysfunction, once thought to be indicative of irreversible tissue damage, is in many cases reversible. This has led to the concepts of myocardial "stunning"1'2 and "hibernation."3 In both of these conditions, myocardial function is reversibly compromised; in stunning, myocardial function is decreased in response to a previous ischemic insult, and blood...

Reduced nephron endowment is associated with development of renal and cardiovascular disease. We hypothesized this may be attributable to impaired sodium homoeostasis by the remaining nephrons. The present study investigated whether a nephron deficit, induced by fetal uninephrectomy at 100 days gestation (term=150 days), resulted in (i) altered renal sodium handling both under basal conditions ...