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Given the high-level physiological functions and nutrient concentrations of bark that cover the entire trunks of huge trees, research into bark nutrient traits and the development of models that estimate the bark biomass of tropical trees is essential when it is sought to understand forest nutrient cycling and tree ecological traits. This study investigated the concentrations of six bark nutrients (nitrogen (N), phosphorus (P), potassium (K), calcium (Ca), magnesium (Mg), and sodium (Na)) by individual tree size and the soil nutrient concentrations for two major pioneer species (Macaranga gigantea and M. hosei) of Malaysia. To estimate bark biomass, allometric equations using tree diameter, height, and crown diameter were developed by combining previous data from adjacent forests with the present data. We found no significant relationship between tree size and most bark nutrient concentrations, though all nutrient concentrations of the two pioneer trees were significantly higher than those of primary forest tree species. Surprisingly, no relationship was found between the soil and bark nutrient concentrations for either species. All the size parameters used in the allometric equations accurately estimated bark biomass. There were no differences in equations between the two species when diameter served as an explanatory variable, but differences were apparent when height and crown diameter were so used. A comparison of allometric equations that yielded the bark biomasses of different types of forest showed that the bark biomass of the tropical secondary forest trees was less than half of that of tropical dry forest trees of the same diameter. Thus, the use of inappropriate equations and nutrient concentrations increases the possibility of serious errors in estimating bark biomass and forest nutrient cycles.

Phosphorus (P) limitation is pervasive in tropical forests. Here the authors analyse the dependence of photosynthesis on leaf N and P in tropical forests, and show that incorporating leaf P constraints in a terrestrial biosphere model enhances its predictive power.

To predict the dynamics of tropical rainforest ecosystems in response to climate change, it is necessary to understand the drought tolerance and related mechanisms of trees in tropical rainforests. In this study, we assessed the ecophysiological responses of seedlings of six dipterocarp species (Dipterocarpus pachyphyllus, Dryobalanops aromatica, Shorea beccariana, S. curtisii, S. parvifolia, and S. smithiana) to experimental short-term drought conditions. The seedlings were initially grown in plastic pots with sufficient irrigation; irrigation was then stopped to induce drought. Throughout the soil-drying period, we measured various ecophysiological parameters, such as maximum photosynthetic and transpiration rates, stomatal conductance, water-use efficiency, predawn water potential, the maximum quantum yield of photosystem II (Fv/Fm), leaf water characteristics (using pressure-volume curves), leaf water content, and total sugar and starch contents. In all six dipterocarp species studied, the Fv/Fm values dropped sharply when the soil water content fell below 8%. However, there were interspecific differences in physiological responses to such a decrease in soil water content: S. parvifolia and S. beccariana actively controlled their stomata during drought to reduce water consumption via an isohydric response, but showed an increase (S. parvifolia) or no change (S. beccariana) in leaf drought tolerance; Di. pachyphyllus and Dry. aromatica maintained photosynthesis and transpiration close to the wilting point during drought without reducing water consumption via an anisohydric response, and also increased their leaf drought tolerance over the drying period; and S. curtisii and S. smithiana maintained their photosynthetic capacity without stomatal closure, but showed no change or a slight decrease in leaf drought tolerance. Our results indicate that extreme drought can cause the death of dipterocarp seedlings via various drought response, which could substantially impact the future distribution, population dynamics, and structure of tropical rainforests.

Although leaf toughness is an essential plant adaptation to herbivore pressure and environmental stress, the relationships of leaf toughness with leaf anatomy and photosynthetic traits, and its spatial variations within tropical rainforests, remain poorly understood. We measured these traits in 103 tree species belonging to 27 families from the canopy to understory using a canopy crane system in a tropical rainforest in Sarawak, Malaysia. We focused on the leaf anatomical trait of bundle-sheath extensions (BSEs) around the vascular bundle due to their diverse ecophysiological functions. We divided the trees into heterobaric species with BSEs and homobaric species lacking BSEs, to investigate the relationships of leaf toughness with tree height, leaf functional traits such as carbon (C) and nitrogen (N) content, thickness, leaf mass per area (LMA) and the maximum photosynthetic rate (Pmax). Leaf toughness, LMA, thickness and C and N contents increased with height regardless of BSE presence. Heterobaric leaves had greater toughness than homobaric leaves, whereas leaf thickness, LMA and C were similar between the two leaf types throughout the height gradient. We found that standardized toughness per thickness or C was greater in heterobaric species, as BSEs consist mainly of fibrous tissue. Pmax was higher for heterobaric than homobaric leaves in the upper canopy presumably due to the functions of BSEs, including water conductivity, but did not differ with plant type in the lower layers. In other words, heterobaric species efficiently exploit the advantages of tougher leaves and higher Pmax by having BSEs. The increased proportion of heterobaric species, with their tougher leaves and higher Pmax, in the upper canopy is consistent with adaptation to physically stressful conditions in the tropical rainforest canopy, including high herbivore pressure and strong light.

The effects of climate change on forest ecosystems take on increasing importance more than ever. Information on plant traits is a powerful predictor of ecosystem dynamics and functioning. We reviewed the major ecological traits, such as foliar gas exchange and nutrients, xylem morphology and drought tolerance, of Cryptomeria japonica and Chamaecyparis obtusa, which are major timber species in East Asia, especially in Japan, by using a recently developed functional trait database for both species (SugiHinokiDB). Empirically, C. obtusa has been planted under drier conditions, whereas C. japonica, which grows faster but thought to be less drought tolerant, has been planted under wetter conditions. Our analysis generally support the empirical knowledge: The maximum photosynthetic rate, stomatal conductance, foliar nutrient content and soil-to-foliage hydraulic conductance were higher in C. japonica than in C. obtusa. In contrast, the foliar turgor loss point and xylem pressure corresponding to 50% conductivity, which indicate drought tolerance, were lower in C. obtusa and are consistent with the drier habitat of C. obtusa. Ontogenetic shifts were also observed; as the age and height of the trees increased, foliar nutrient concentrations, foliar minimum midday water potential and specific leaf area decreased in C. japonica, suggesting that nutrient and water limitation occurs with the growth. In C. obtusa, the ontogenetic shits of these foliar traits were less pronounced. Among the Cupressaceae worldwide, the drought tolerance of C. obtusa, as well as C. japonica, was not as high. This may be related to the fact that the Japanese archipelago has historically not been subjected to strong dryness. The maximum photosynthetic rate showed intermediate values within the family, indicating that C. japonica and C. obtusa exhibit relatively high growth rates in the Cupressaceae family, and this is thought to be the reason why they have been selected as economically suitable timber species in Japanese forestry. This study clearly demonstrated that the plant trait database provides us a promising opportunity to verify out empirical knowledge of plantation management and helps us to understand effect of climate change on plantation forests by using trait-based modelling.

Conservation of rare species is essential for maintaining ecosystem function. Quercus hondae is a rare evergreen oak species (Cyclobalanopsis) endemic to Japan. This species is found in several locations in Southwestern Japan; small populations remain in the tutelary forests of the Japanese shrine. To evaluate the genetic diversity and phylogeographic structure of this rare species, 11 microsatellite loci and chloroplast DNA sequences are analyzed for 12 populations of Q. hondae and 8 populations of the more widespread congeneric species, Q. glauca. It is found that heterozygosity at both the population and species level is substantially lower in Q. hondae than in Q. glauca. Genetic differentiation among populations of Q. hondae was high, in contrast to Q. glauca, in which populations exhibit largely insignificant differentiation. STRUCTURE analysis shows that at K = 7, the clusters largely corresponded to major predefined populations. This study suggests that there is little gene flow among extant Q. hondae populations and that Q. hondae is genetically differentiated due to the greater effect of genetic drift in small populations. This pattern is in sharp contrast to that of a more common congeneric species, which will be an important consideration in the conservation of Q. hondae.

As climate change progresses, it is becoming more crucial to understand how timber species respond to increased drought frequency and severity. Photosynthetic traits in a 40-year-old clonal Japanese cedar (Cryptomeria japonica) plantation were assessed under artificial drought stress using a roof to exclude rainfall and a control with no exclusion. C. japonica is a commercial tree that is native to Japan and has high growth on mesic sites. The maximum carboxylation rate (Vcmax), maximum electron transfer rate (Jmax), and dark respiration rate (Rd) in current-year shoots in the upper canopy were determined from spring to autumn over two growing seasons. In addition, the photosynthetic rate at light saturation (Pmax), stomatal conductance (gs), and intrinsic water use efficiency (WUEi) were measured in the morning and afternoon during the same period. Leaf mass per unit area (LMA) and nitrogen concentration (N) were also measured. The values of Vcmax, Jmax, Rd, N, and LMA did not differ between the two plots. By contrast, significantly lower Pmax and gs and higher WUEi were found in the drought plot, and the reduction in Pmax was accompanied by low gs values. Midday depressions in Pmax and gs were more pronounced in the drought plot relative to the control and were related to higher WUEi. Under drought conditions, mature Japanese cedar experienced little change in photosynthetic capacity, foliar N, or LMA, but they did tend to close the stomata to regulate transpiration, thus avoiding drought-induced damage to the photosynthetic machinery and improving WUEi.

Asymmetric addition of cyanotrimethylsilane with aldehydes enhanced by acyclic dipeptide esters and alpha-amino acid amides whose N-terminals were modified by 4-toluenesulfonyl, 1-methyl-2-acetylvinyl or (2-hydroxy-1-naphthyl)methylene groups was reported. The products of the reaction of benzaldehydes using several peptide-aluminum complexes were obtained in different yields and reaction times. Characterizations were done by 1H NMR analyses.

Background: Community-onset pneumonia (COP) is a combined concept of community acquired pneumonia and the previous classification of healthcare-associated pneumonia. Although ceftriaxone (CRO) is one of the treatment choices for COP, it is unclear whether 1 or 2 g CRO daily has better efficacy. We compared the effectiveness of 1 g with 2 g of CRO for COP treatment. We hypothesized that 1 g CRO would show non-inferiority over 2 g CRO.Methods: This study was an analysis of prospectively registered data of the patients with COP from four Japanese hospitals (the Adult Pneumonia Study Group-Japan: APSG-J). We included subjects who were initially treated solely with 1 or 2 g of CRO. The propensity score was estimated from the 33 pre-treatment variables, including age, sex, weight, pre-existing comorbidities, prescribed drugs, risk factors for aspiration pneumonia, vital signs, laboratory data, and a finding from chest xrays. The primary endpoint was the cure rate, for which a non-inferiority analysis was performed with a margin of 0.05. In addition, we performed three sensitivity analyses; using data limited to the group in which CRO solely was used until the completion of treatment, using data limited to inpatient cases, and performing a generalized linear mixed-effect logistic regression analysis to assess the primary outcome after adjusting for random hospital effects.Results: Of the 3817 adult subjects with pneumonia who were registered in the APSG-J study, 290 and 216 were initially treated solely with 1 or 2 g of CRO, respectively. Propensity score matching was used to extract 175 subjects in each group. The cure rate was 94.6 and 93.1% in the 1 and 2 g CRO groups, respectively (risk difference 1.5%; 95% confidence interval - 3.1 to 6.0; p = 0.009 for non-inferiority). The results of the sensitivity analyses were consistent with the primary result.Conclusions: The propensity score-matched analysis of multicenter cohort data from Japan revealed that the cure rate for COP patients treated with 1 g daily CRO was non-inferior to that of patients treated with 2 g daily CRO. [ABSTRACT FROM AUTHOR]

Climate change exposes vegetation to unusual levels of drought, risking a decline in productivity and an increase in mortality. It still remains unclear how trees and forests respond to such unusual drought, particularly Southeast Asian tropical rain forests. To understand leaf ecophysiological responses of tropical rain forest trees to soil drying, a rainfall exclusion experiment was conducted on mature canopy trees of Dryobalanops aromatica Gaertn.f. (Dipterocarpaceae) for 4 months in an aseasonal tropical rain forest in Sarawak, Malaysia. The rainfall was intercepted by using a soft vinyl chloride sheet. We compared the three control and three treatment trees with respect to leaf water use at the top of the crown, including stomatal conductance (gsmax), photosynthesis (Amax), leaf water potential (predawn: Ψpre; midday: Ψmid), leaf water potential at turgor loss point (πtlp), osmotic potential at full turgor (π100) and a bulk modulus of elasticity (ε). Measurements were taken using tree-tower and canopy-crane systems. During the experiment, the treatment trees suffered drought stress without evidence of canopy dieback in comparison with the control trees; e.g., Ψpre and Ψmid decreased with soil drying. Minimum values of Ψmid in the treatment trees decreased during the experiment, and were lower than πtlp in the control trees. However, the treatment trees also decreased their πtlp by osmotic adjustment, and the values were lower than the minimum values of their Ψmid. In addition, the treatment trees maintained gs and Amax especially in the morning, though at midday, values decreased to half those of the control trees. Decreasing leaf water potential by osmotic adjustment to maintain gs and Amax under soil drying in treatment trees was considered to represent anisohydric behavior. These results suggest that D. aromatica may have high leaf adaptability to drought by regulating leaf water consumption and maintaining turgor pressure to improve its leaf water relations. [ABSTRACT FROM AUTHOR]

To develop rehabilitation planting techniques in tropical degraded forests, we investigated (1) basic soil characteristics and light conditions; (2) growth and survival of seven dipterocarp seedlings over 81 months; and (3) the effect of environmental factors on the survival of seedlings grown in three degraded vegetations (grassland, secondary forest, and logged forest) in Sarawak, Malaysia. The soil was weakly acidic, and kaolin minerals dominated. The amount of exchangeable bases in surface soils, soil temperature (>35°C), and relative light intensity were all highest in the grassland. Seedling growth was also highest in the grassland, whereas many seedlings died there over 81 months. Growth and survivability were very similar in secondary and logged forests. The death of the seedlings in the grassland was attributable to an extremely high light intensity for all species. In contrast, the seedling growth rate in all species was also enhanced by light intensity. In conclusion, dipterocarp seedlings can be planted on highly degraded land such as grassland, although high light intensity limits their survival. Planting under nurse trees such as regenerated pioneer trees may be an effective method to enhance seedling survival under open conditions such as grassland. [ABSTRACT FROM AUTHOR]

In Japan, the population of elderly individuals (those sixty-five years of age and older) will increase to over 30 percent of the total population by 2030. The elderly commonly have chronic diseases that result in individuals being biologically and pharmacologically compromised. Dentists must have a reliable knowledge of basic clinical medicine for these individuals to be safely and effectively treated. The isolation of dental education from medical education may have been advantageous in the past for the development of dentistry as a profession; however, changes in people's life expectancy and lifestyles, as well as rapid advances in the biomedical sciences, require dentists to have a thorough foundation in biomedical science and clinical medicine not dissimilar from a physician in any other field of medicine. A reformation of dental education is necessary if optimum oral health care is to be provided for patients in the future. It is thus advocated that dentistry should become one specialty of medicine known as oral medicine, and we propose that the education of dentists should be modified to produce oral physicians. [ABSTRACT FROM AUTHOR]

An amendment to this paper has been published and can be accessed via a link at the top of the paper. [ABSTRACT FROM AUTHOR]

Photosynthetic rate, nitrogen concentration and morphological properties of canopy leaves were studied in 18 trees, comprising five dipterocarp species, in a tropical rain forest in Sarawak, Malaysia. Photosynthetic rate at light saturation (P max) differed significantly across species, varying from 7 to 18 µmol m–2 s–1. Leaf nitrogen concentration and morphological properties, such as leaf blade and palisade layer thickness, leaf mass per area (LMA) and surface area of mesophyll cells per unit leaf area (A mes/A), also varied significantly across species. Among the relationships with leaf characteristics, P max had the strongest correlation with leaf mesophyll parameters, such as palisade cell layer thickness (r 2 = 0.76, P < 0.001) and A mes/A (r 2 = 0.73, P < 0.001). Leaf nitrogen concentration and P max per unit area also had a significant but weaker correlation (r 2 = 0.46, P < 0.01), whereas P max had no correlation, or only weakly significant correlations, with leaf blade thickness and LMA. Shorea beccariana Burck, which had the highest P max of the species studied, also had the thickest palisade layer, with up to five or more layers. We conclude that interspecific variation in photosynthetic capacity in tropical rain forest canopies is influenced more by leaf mesophyll structure than by leaf thickness, LMA or leaf nitrogen concentration. [ABSTRACT FROM AUTHOR]

In this multiinstitute cooperative study, 143 patients were treated with either urokinase (UK) or combination of urokinase and dextran sulfate (UK-DS) within one to seven days following acute onset of cerebral thrombotic infarction. Of these, 81 randomized cases received a single dose of UK (2.83 × 105 units) by six-hour intravenous drip infusion and the remaining 62 received a combined dose of UK (2.84 × 105 units) and DS (3000mg) for only one day. Moderate to marked clinical improvements assessed during the seven-day study period were observed in 30.9% of the patients treated with UK and in 61.3% of those with UK-DS, the latter being significantly higher. Hemorrhagic phenomena appeared in 3.2% of the cases treated with UK-DS and in none of those with UK alone, but mortality was 1.6% in the former and 2.5% in the latter. UK-DS produced a prompt and sustained increase in plasma fibrinolytic activity with transient and relatively minor disturbance of the blood coagulation system. The results indicate that combined therapy with UK and DS is more effective than UK alone for acute cerebral thrombotic infarction. [ABSTRACT FROM AUTHOR]

To compare the clinical features associated with stroke in hypertensive patients with those in nonhypertensives, we analyzed the records and the autopsy findings of cases of cerebral infarction in the Hisayama prospective study from 1961 through 1973. Of the total 128 cases of cerebral infarction, 79 (61.7%) occurred in patients admitted as hypertensives. In addition, of the 17 normotensive subjects at entry, (29.4%) had blood pressure levels that shifted into the hypertension range while 13 of 18 (72.2%) with borderline hypertension at entry had blood pressure levels that changed into the hypertensive range before stroke. In reviewing clinical symptoms and autopsy findings we frequently found that small, deep cerebral infarction, most often located in basal ganglia, in hypertensive old persons. On the other hand, arrhythmia on ECG and focal infarcts on sytemic organs of the body were more often found in nonhypertensive patients with cerebtal infarction than in hypertensives. This suggested that embolism of cardiac origin may at least contribute to the development of cerebral infarction in nonhypertensive subjects. [ABSTRACT FROM AUTHOR]