The dynamics of carbon stored in xylem sapwood to drought-induced hydraulic stress in mature trees.

Climate-induced forest die-off is widespread in multiple biomes, strongly affecting the species composition, function and primary production in forest ecosystems. Hydraulic failure and carbon starvation in xylem sapwood are major hypotheses to explain drought-induced tree mortality. Because it is difficult to obtain enough field observations on drought-induced mortality in adult trees, the current understanding of the physiological mechanisms for tree die-offs is still controversial.

Accumulation of p53 via down-regulation of UBE2D family genes is a critical pathway for cadmium-induced renal toxicity.

Chronic cadmium (Cd) exposure can induce renal toxicity. In Cd renal toxicity, p53 is thought to be involved. Our previous studies showed that Cd down-regulated gene expression of the UBE2D (ubiquitin-conjugating enzyme E2D) family members.

Comparisons of energy cost and economical walking speed at various gradients in healthy, active younger and older adults.

Background/objective: Oxygen consumption during walking per unit distance ( ; mL/kg/m) is known to be greater for older adults than younger adults, although its underlying process is controversial.

Methods: We measured the values at six gait speeds from 30 m/min to 105 m/min on level ground and gradient slopes (±5%) in healthy younger and older male adults. A quadratic approximation was applied for a relationship between and gait speeds (; m/min).

Recovery of Physiological Traits in Saplings of Invasive Bischofia Tree Compared with Three Species Native to the Bonin Islands under Successive Drought and Irrigation Cycles.

Partial leaf shedding induced by hydraulic failure under prolonged drought can prevent excess water consumption, resulting in delayed recovery of carbon productivity following rainfall. To understand the manner of water use of invasive species in oceanic island forests under a fluctuating water regime, leaf shedding, multiple physiological traits, and the progress of embolism in the stem xylem under repeated drought-irrigation cycles were examined in the potted saplings of an invasive species, Bischofia javanica Blume, and three endemic native species, Schima mertensiana (Sieb. Et Zucc,) Koitz.

Effective use of high CO₂ efflux at the soil surface in a tropical understory plant.

Many terrestrial plants are C3 plants that evolved in the Mesozoic Era when atmospheric CO2 concentrations ([CO2]) were high. Given current conditions, C3 plants can no longer benefit from high ambient [CO2]. Kaempferia marginata Carey is a unique understory ginger plant in the tropical dry forests of Thailand.

Responses of the photosynthetic apparatus to winter conditions in broadleaved evergreen trees growing in warm temperate regions of Japan.

Photosynthetic characteristics of two broadleaved evergreen trees, Quercus myrsinaefolia and Machilus thunbergii, were compared in autumn and winter. The irradiance was similar in both seasons, but the air temperature was lower in winter. Under the winter conditions, net photosynthesis under natural sunlight (Anet) in both species dropped to 4 μmol CO2 m(-2) s(-1), and the quantum yield of photosystem II (PSII) photochemistry in dark-adapted leaves (Fv/Fm) also dropped to 0.