No abstract

In a warming climate, temperature-sensitive plants must move toward colder areas, that is, higher latitude or altitude, by seed dispersal [1]. Considering that the temperature drop with increasing altitude (-0.65°C per 100 m altitude) is one hundred to a thousand times larger than that of the equivalent latitudinal distance [2], vertical seed dispersal is probably a key process for plant escape from warming temperatures. In fact, plant geographical distributions are tracking global warming altitudinally rather than latitudinally, and the extent of tracking is considered to be large in plants with better-dispersed traits (e.g., lighter seeds in wind-dispersed plants) [1]. However, no study has evaluated vertical seed dispersal itself due to technical difficulty or high cost. Here, we show using a stable oxygen isotope that black bears disperse seeds of wild cherry over several hundred meters vertically, and that the dispersal direction is heavily biased towards the mountain tops. Mountain climbing by bears following spring-to-summer plant phenology is likely the cause of this biased seed dispersal. These results suggest that spring- and summer-fruiting plants dispersed by animals may have high potential to escape global warming. Our results also indicate that the direction of vertical seed dispersal can be unexpectedly biased, and highlight the importance of considering seed dispersal direction to understand plant responses to past and future climate change.

We examined the incidence rates of psychiatric disorders in end-stage renal failure patients on hemodialysis (HD) based on 4-year long-term follow-up. Among various psychiatric disorders, the frequency of three psychiatric disorders, dementia, delirium, and major depression, was relatively high. One-year incidence rate of whole psychiatric disorders was 10.6% (7.1% in non-aged and 13.7% in aged). One-year incidence rate of dementia in aged patients was 4.2% (dementia of the Alzheimer’s disease, 0.5%; multi-infarct dementia, 3.7%). One-year incidence rate of multi-infarct dementia in aged HD patients was 7.4 times as large as that in the elderly general populations, suggesting that aged HD patients tend to exhibit multi-infarct dementia. The high incidence rate may be closely related to advanced arteriosclerosis and other medical conditions. Psychiatric management is required for ESRD patients with three major psychiatric disorders, dementia, delirium, and major depression, in particular for aged patients with multi-infarct dementia who has received long-term HD therapy.

We investigated the influence of the extracellular nitric oxide (NO) level on male copulatory behavior. We confirmed the changes of nitrite ([Formula: see text]) and nitrate ([Formula: see text]) in the medial preoptic area (MPOA) by administration of the NO precursorl-arginine (l-Arg, 10 mM) or the NO synthase inhibitor N G-monomethyl-l-arginine (l-NMMA, 10 mM) via a dialysis probe. [Formula: see text] and[Formula: see text] were measured simultaneously by an in vivo microdialysis method coupled with the Griess reaction.l-Arg induced significant elevations of extracellular [Formula: see text]and [Formula: see text].l-NMMA significantly reduced[Formula: see text] and[Formula: see text] levels. We observed male copulatory behavior during infusion ofl-Arg orl-NMMA. The mount rate of male rats significantly increased during infusion ofl-Arg in the MPOA. Administration of l-NMMA reduced the mount rate. These findings suggested that the elevation of extracellular NO in the MPOA facilitates male copulatory behavior of rats, whereas the decrease of NO reduces their copulatory behavior.