Search

The purpose of this study was to explore reliability and differences of jump kinetics related to different training load in college male athletes. The subjects were required to perform countermovement jump (CMJ) and loaded countermovement jump (LCMJ-0%, LCMJ-20% and LCMJ-80% of one-repetition maximum squat) three times for each load which were recorded by a force plate. One-way repeated measures ANOVA and the LSD post hoc method were employed to evaluate the results. The results reveled that jump kinetics-related parameters increased/decreased by the load. Compared with the loading jumps, the CMJ incorporate with an arm swing directly led to an increase in eccentric contraction duration during jumping. Most of the jump mechanical parameters under substantially different load conditions fall within the good to excellent reliability. It appears that the CMJ and CMJ with extra load were reliable in explore the kinetics related parameters. Keywords: countermovement jump, one-repetition maximum, arm swing, eccentric contraction

Cystic fibrosis (CF) is a progressive multi organ autosomal recessive disease with devastating impact on the lungs caused by derangements of the cystic fibrosis transmembrane conductance regulator (CFTR) gene. Morbidity and mortality in CF are largely caused by lung complications due to the triad of impaired mucociliary clearance, microbial infections and chronic inflammation. P. aeruginosa is a main respiratory pathogen in individuals with CF infecting most patients in later stages. Despite its recognized clinical impact, the molecular mechanisms that underlie P. aeruginosa pathogenesis and the host response to P. aeruginosa infection remain incompletely understood. The nuclear hormone receptor peroxisome proliferator-activated receptor gamma (PPARγ) an important modulator of inflammation and host defense, has shown to be reduced in CF airways. In this study we sought to investigate the upstream mechanisms repressing PPARγ expression and its impact on airway epithelial host defense. Endoplasmic Reticulum-stress (ER-stress) triggered unfolded protein response (UPR) activated by misfolded CFTR and P. aeruginosa infection contributed to attenuated expression of PPARγ. Specifically, the PERK signaling pathway lead to the enhanced expression of the CCAAT-enhancer-binding-protein homologous protein (CHOP). CHOP induction led to the repression of PPARγ expression. Mechanistically, we show that CHOP induction mediated PPARγ attenuation, impacted the innate immune function of normal, ΔF508 primary airway epithelial as well as bronchial epithelial cells by reducing expression of anti-microbial peptide (AMP) and paraoxanse-2 (PON-2), as well as enhancing IL-8 expression. Furthermore, mitochondrial reactive oxygen species production (mt-ROS) and ER stress positive feedforward loop also dysregulated mitochondrial bioenergetics. Additionally, our findings implicate that PPARγ agonist pioglitazone (PIO) has beneficial effect on the host at the multicellular level ranging from host defense to mitochondrial re-energization.

The innate immune response to

The primary objective of this study was to design a digging agility system that was used to analyze the effectiveness of 6 weeks of plyometric training on volleyball players. A total of 24 highly trained college male volleyball players were recruited for this study. The players were equally divided into a plyometric training group and a control group. The agility T-test, peak power output test, 10-meter sprint, and digging agility test were used to examine the effects of plyometric training on the digging agility of volleyball players. One-way analysis of covariance was conducted to examine the differences in the variables between groups. The results reveal that after 6 weeks of plyometric training, the plyometric training group had significant improvements on the agility T-test, digging agility test, and peak power output tests, with statistical power values all greater than 90%. The plyometric training group significantly improved by 2.68% on the agility T-test, 2.35% on the digging agility test, and 7.32% on the peak power output test. The results indicated that appropriate plyometric training can enhance the agility of lateral movements and peak output of vertical jumps, as well as enable players to rapidly complete movements during a moving defense.

The aim of this study was to examine the effects of different agility training methods on skill-related physical capabilities in young volleyball players. Twenty-seven young female volleyball players were randomly assigned to a shuttle-run training group (STG, n = 9), an agility-ladder training group (ATG, n = 9), and a control group (CG, n = 9). The intervention program was carried out three times a week for six weeks. Before and after the training period, participants’ 10 m sprint (10 MS), agility T-test, and digging agility test (DAT) performances were assessed. Within-group analysis showed significant improvements (p < 0.05) in the DAT, agility T-test, and 10 MS performance from pre- to post-test for the STG (6.08%, 2.64%, and 5.68%, respectively) and ATG (4.05%, 3.28%, and 3.27%, respectively). In the group analysis, there were significant differences (p < 0.05) between the STG and CG in the DAT and agility T-test. The STG and ATG were significantly superior to the CG in the 10 MS (p < 0.05). In conclusion, the results indicate that appropriate agility training can enhance the agility of lateral movements and speed of sprinting, as well as enable players to rapidly complete movements during a moving defense.

The innate immune response to P. aeruginosa pulmonary infections relies on a network of pattern recognition receptors, including intracellular inflammasome complexes, which can recognize both pathogen- and host-derived signals and subsequently promote downstream inflammatory signaling. Current evidence suggests that the inflammasome does not contribute to bacterial clearance and, in fact, that dysregulated inflammasome activation is harmful in acute and chronic P. aeruginosa lung infection. Given the role of mitochondrial damage signals in recruiting inflammasome signaling, we investigated whether mitochondrial-targeted therapies could attenuate inflammasome signaling in response to P. aeruginosa and decrease pathogenicity of infection. In particular, we investigated the small molecule, ZLN005, which transcriptionally activates peroxisome proliferator-activated receptor-γ coactivator-1α (PGC-1α), a master regulator of mitochondrial biogenesis, antioxidant defense, and cellular respiration. We demonstrate that P. aeruginosa infection promotes the expression of inflammasome components and attenuates several components of mitochondrial repair pathways in vitro in lung epithelial cells and in vivo in an acute pneumonia model. ZLN005 activates PGC-1α and its downstream effector, Sirtuin 3 (SIRT3), a mitochondrial-localized deacetylase important for cellular metabolic processes and for reactive oxygen species homeostasis. ZLN005 also attenuates inflammasome signaling induced by P. aeruginosa in bronchial epithelial cells and this action is dependent on ZLN005 activation of SIRT3. ZLN005 treatment reduces epithelial-barrier dysfunction caused by P. aeruginosa and decreases pathogenicity in an in vivo pneumonia model. Therapies that activate the PGC-1α—SIRT3 axis may provide a complementary approach in the treatment of P. aeruginosa infection.

The purpose of this research was to study the effects of a whole-body vibration (WBV) warm-up for improving fencers' performance on variables derived from a lunge reaction test, the 10-meter sprint, and the countermovement jump. We compared fencer performances at four time intervals: (a) preintervention, (b) immediately postintervention, (c) 1-minute postintervention, and (d) 2-minute postintervention. Study participants were 16 male fencers. The vibration frequency was 30 Hz, and its amplitude was two mm. After each WBV session, participants significantly improved their performance on all measures at both one and two minutes after the intervention. Specifically, lunge reaction tests scores improved by 5.50% and 7.34%, respectively, relative to preintevention testing ( p

Badminton atypical actions and hitting movements often occur during the game; therefore, many special footwork methods have been developed to facilitate the rapid movements required to hit the shuttlecock, including quick turning and jumping and quick directional change movements. Studies have shown that the majority of badminton sport injuries occur in the lower extremity joints of athletes. The purpose of this study was to investigate the influences of hitting motion and unanticipated hitting direction on landing mechanics after backhand lateral jump smashing and landing to analyze joint stiffness and torque changes in three lower extremity joints. Recruited sixteen badminton athletes.The capture frequency of the Vicon Motion System (300Hz), Kistler force platform (1500Hz) and Vicon Nexus Version 1.8.5 software were used simultaneously to capture the kinematic and kinetic parameter of backhand side lateral jump smash footwork. The swing actions were divided into two situations, shadow (footwork and racket swinging practice without targets) and hitting (footwork and stroke shuttlecock) actions, whereas the directions were divided into directional and non-directional. Two-way repeated measures ANOVA with the LSD correction was used to compare the differences among the four conditions. The significance level was set to a = 0.05. Results shown that, at the peak of torque, the ankle plantar flexion of the non-directional shadow (p < 0.05) were greater than that of directional shadow (p < 0.05); meantime, ankle torque change of non-directional shadow (p < 0.05) and directional hitting (p < 0.05) was lower than that of non-directional hitting, but the non-directional hitting was larger compared to non-directional shadow (p < 0.05) at the maximum vertical GRF. The hip extension at peak of torque of directional hitting were larger than that of non-directional shadow (p < 0.05). The shadow actions hip flexion angle was larger than that of directional hitting at initial contact, but the non-directional hitting hip abduction was has the significant difference among all the conditioning. The hip flexion angle of non-directional shadow was larger than that of directional hitting (p < 0.05), the hip abduction angle of the non-directional hitting was greater than that of non-directional shadow (p < 0.05) at the peak VGRF. Elite badminton players execute different training movements; the joint stiffness was in the same state. In the hitting actions has greater ankle and hip joint torque than shadow actions. The badminton player was change joint range of motion to adjust lower limbs stiffness.

The agility T-test and countermovement jump test have long been used to examine the agility of athletes. However, for some sports, newer systems of evaluation are being designed for specific movements. The goal of this study was to design a blocking agility system and apply it to analyzing the efficiency of 6 weeks of plyometric training on volleyball players. A total of 26 male volleyball players in Taiwan participated in the study. The participants were divided into a plyometric training group and a control group. The agility T -test, countermovement jump test, and blocking agility test were used to examine the influence of plyometric training on the blocking agility of volleyball players. A single-factor analysis of covariance was applied to obtain the variables for the two groups. There was no significant difference between the groups on the agility T -test. On the countermovement jump test and blocking agility test, the plyometric training group performed significantly better than the control group. Also, the power values of blocking agility were higher than 90%, which demonstrated very good validity. The results of this study indicate that appropriate plyometric training can increase the rate of force development for vertical jumps and significantly enhance the combined agility of volleyball players in terms of lateral-movement speed and quickness, which enable players to rapidly perform blocking actions.

Litterfall is important for returning nutrients and carbon to the forest floor, and microbes decompose the litterfall to release CO2 into the atmosphere. Litterfall is a pivotal component in the forest biogeochemical cycle, which is sensitive to climate variability and plant physiology. In this study, we combined field litterfall estimates and time series (2001–2011) climate (the Moderate Resolution Imaging Spectroradiometer (MODIS) land surface temperature (LST) and Tropical Rainfall Measuring Mission (TRMM) precipitations) and green vegetation (MODIS photosynthetically active vegetation cover (PV)) variables to estimate regional annual litterfall in tropical/subtropical forests in Taiwan. We found that time series MODIS LST- and PV-derived metrics, the annual accumulated MODIS LST, and coefficient of variation of PV, respectively, but not the TRMM precipitation variables were salient factors for the estimation (r2 = 0.548 and p

In volleyball matches, there are three minute intervals between sets. Therefore, the improvement of the muscle output ratio is one of the most import foundational physical elements for the players. The purpose of this study was to investigate the effects of plyometric training on the changes in electrical signals in the lower limb muscles of male college volleyball players during continuous blocking and to examine the benefits of plyometric training on blocking agility and maximum vertical jump height. In this study, twenty elite male college volleyball players were recruited and divided into a plyometric training group (PTG) and a control group (CG). The wireless electromyography was used for data acquisition, and the electrodes were applied to the left and right rectus femoris, biceps femoris, tibialis anterior, and gastrocnemius. The median frequency was used as the measurement of the electromyographic signals during the jumping blocks. This study used covariate analysis methods, with previously measured results used as covariates to perform a two-way analysis of covariance for the independent samples. Based on the results of this study, after 6 weeks of training, the median frequency of the rectus femoris (2.13% to 4.75% improved) and that of the tibialis anterior muscles (4.14% to 7.71% improved) were significantly lower in the PTG than in the CG. Additionally, the blocking agility increased by 6.26% and the maximum vertical jump height increased by 3.33% in the PTG compared to the CG. The findings provide important insights on the neuromuscular status for volleyball players during continuous blocking jumps. Six weeks of appropriate plyometric training can facilitate the performance of volleyball players.

Background/objective: The application of Micro-Electro-Mechanical Sensors (MEMS) as measurements of energy expenditure (EE) has certain disadvantages. For example, the inertial sensors cannot easily distinguish changes in ground slope during walking/running conditions, so the accuracy of EE calculation is biased. To resolve this issue, heart rate (HR) and heart rate reserve (HRR) were used as compensatory factors respectively to correct the classical empirical formula of the accelerometer analyzer for EE in this study. Methods: To explore the improvement of the accuracy of EE during uphill exercise and compare the correction levels between HR and HRR, oxygen uptake was used as a criterion measure (CM). Thirty healthy adult males wore an ActiGraph GT3X with the Polar HR monitor and Vmax indirect calorimeter during twelve treadmill activities (3 gradients and 4 speeds). Results: When the slopes were increased by 0%, 3%, and 6%, the measurement accuracy of the accelerometers, calculated by intraclass correlation coefficient (ICC), decreased by 0.877, 0.755, and 0.504, respectively (p

Questions: What are the effects of replacing mixed species natural forests withCryptomeria japonica plantations on understorey plant functional and speciesdiversity? What is the role of the understorey light environment in determiningunderstoreydiversityandcommunityinthetwotypesofforest?Location:SubtropicalnortheastTaiwan.Methods: We examined light environments using hemispherical photography,and diversity and composition of understorey plants of a 35-yr C. japonica plan-tationandanadjacentnaturalhardwoodforest.Results: Understorey plant species richness was similar in the two forests, butthe communities were different; only 18 of the 91 recorded understorey plantspecies occurred in both forests. Relative abundance of plants among differentfunctional groups differed between the two forests. Relative numbers of shade-tolerant and shade-intolerant seedling individuals were also different betweenthe two forest types with only one shade-intolerant seedling in the plantationcompared to 23 seedlings belonging to two species in the natural forest. In thenatural forest 11 species of tree seedling were found, while in the plantationonly five were found, and the seedling density was only one third of that in thenaturalforest. Acrossplots inbothforests,understorey plant richnessanddiver-sity were negatively correlated with direct sunlight but not indirect sunlight,possibly because direct light plays a more important role in understorey plantgrowth.Conclusions: We report lower species and functional diversity and higher lightavailabilityinanaturalhardwoodforestthananadjacent30-yrC. japonicaplan-tation,possiblyduetotheincreaseddominanceofshade-intolerantspeciesasso-ciated with higher light availability. To maintain plant diversity, managementefforts must be made to prevent localized losses of shade-adapted understoreyplants.IntroductionForest canopies are light-absorbing objects that efficientlyreduce light availability in the forest understorey (Kimmins1996), resulting in low light availability for understoryplant growth. In most forests there is high variability of un-derstorey light availability, which allows the co-existenceof plants with different light requirements (Canham et al.1990). Therefore, changes in light environments haveprofound effects on productivity and diversity of understo-rey vegetation (Menges 1985; Carol et al. 1992; Zipperlen& Press 1996; Williams et al. 1999; Myers et al. 2000).Changes in forest canopy structure can substantially affectunderstorey light environments, so management practicesleading to changes in canopy cover have major impacts onunderstorey light environments and plant diversity.Forestplantationsareexpandingattheexpenseofnatu-ral forests in many regions, such as South America

The objectives of this study were to assess volleyball speed and impact force and to analyse the differences between these properties. Three types of volleyballs were used in this study: MVA200, weighing 270 ± 10 g; Prototype Ball A (Type A), weighing 270 ± 10 g; and Prototype Ball B (Type B), weighing 340 ± 10 g. Vertically downward 3-m impact tests were conducted using a serving machine, force plate, and radar speed gun. Contact time, ball speed, mean force, peak force, total impulse, initial momentum, incident impulse, and lost momentum were calculated. Intraclass correlation coefficients were calculated to evaluate the reliability of the data, and one-way analysis of covariance and Scheffe’s post hoc analysis were used to analyse the variables of the three ball types. The paired samples t-test was used to compare the difference between initial momentum and incident impulse. The results indicated that the intraclass correlation coefficients of the three ball types were 0.998 (MVA200), 0.997 (Type A), and 0.999 (Type B). Type B considerably surpassed Type A and MVA200 in mechanical factors, and Type A was significantly superior to MVA200 in incident impulse and lost momentum. The results indicated that different volleyballs of the same size, weight, and internal air pressure have dissimilar mechanical features and implied that slight adjustment to ball structure can cause substantial changes in the specific characteristics. In addition, the mass increased the lost momentum, which might cause the ball to bounce unpredictably.

Background Using wearable inertial sensors to accurately estimate energy expenditure (EE) during an athletic training process is important. Due to the characteristics of inertial sensors, however, the positions in which they are worn can produce signals of different natures. To understand and solve this issue, this study used the heart rate reserve (HRR) as a compensation factor to modify the traditional empirical equation of the accelerometer EE sensor and examine the possibility of improving the estimation of energy expenditure for sensors worn in different positions. Methods Indirect calorimetry was used as the criterion measure (CM) to measure the EE of 90 healthy adults on a treadmill (five speeds: 4.8, 6.4, 8.0, 9.7, and 11.3 km/h). The measurement was simultaneously performed with the ActiGraph GT9X-Link (placed on the wrist and waist) with the Polar H10 Heart Rate Monitor. Results At the same exercise intensity, the EE measurements of the GT9X on the wrist and waist had significant differences from those of the CM (p < 0.05). By using multiple regression analysis—utilizing values from vector magnitudes (VM), body weight (BW) and HRR parameters—accuracy of EE estimation was greatly improved compared to traditional equation. Modified models explained a greater proportion of variance (R2) (wrist: 0.802; waist: 0.805) and demonstrated a good ICC (wrist: 0.863, waist: 0.889) compared to Freedson’s VM3 Combination equation (R2: wrist: 0.384, waist: 0.783; ICC: wrist: 0.073, waist: 0.868). Conclusions The EE estimation equation combining the VM of accelerometer measurements, BW and HRR greatly enhanced the accuracy of EE estimation based on data from accelerometers worn in different positions, particularly from those on the wrist.

Chinese fir (Cunninghamia lanceolata) is the most important forest plantation species in subtropical Asia and is rapidly replacing natural forests. Such land-use change may affect ecosystem nutrient cycling through changes in litterfall nutrient flux. Tropical cyclones often cause pulses of litterfall. Previous studies, however, have mostly focused on the effects of a single cyclone with little effort examining the effects of repeated cyclones. We examined litterfall in a natural hardwood forest and a Chinese-fir plantation in central Taiwan experiencing an average of one typhoon per year. The natural hardwood forest had 54 percent higher annual litterfall (11,400 kg/ha/yr) than the Chinese-fir plantation (7400 kg/ha/yr). Four typhoon-affected months (typhoon period) contributed to approximately 60 percent of the litterfall and litterfall element flux in the natural hardwood forest and 80 percent in the Chinese-fir plantation, with contributions from individual typhoons varied by more than twofold. Litterfall N and P concentrations were significantly higher in typhoon period than in non-typhoon period, likely the result of limited retranslocation. Precipitation was a better predictor of quantity of typhoon-associated litterfall than wind velocity. Both types of forests in southeastern China beyond the reach of typhoons have litterfall peaks in the dry season. In contrast, we measured higher litterfall during the typhoon period than during the dry season, suggesting that in regions with frequent cyclones, cyclones drive temporal variation of litterfall. Global climate change is affecting the frequency and intensity of cyclones; therefore, knowledge of typhoon-litterfall dynamics is indispensable for understanding the effects of climate change on ecosystem nutrient cycling. 台灣中部颱風擾動頻繁之天然闊葉林及杉木人工林枯落物及其營養元素通量 杉木是亞熱帶亞洲地區最重要的造林樹種,且正快速取代天然林而擴張中。此土地利用的改變,可能改變枯落物營養的通量進而影響生態系的營養循環。熱帶氣旋常造成大量的枯落物,但之前的研究多聚焦單一熱帶氣旋的影響,甚少探討重覆的熱帶氣旋擾動所造成的影響。台灣中部每年平均經歷一個颱風,本研究比較本區一天然闊葉林與一相鄰的杉木人工林的枯落物型態。結果顯示天然林的年枯落物量(11,400 kg/ha/yr)比杉木人工林(7,400 kg/ha/yr)高54%。四個受颱風影響的月份(颱風時期)的枯落物量及枯落物營養元通量,在天然林佔年總量的60%,在人工杉木林則佔80%,而不同颱風月間的差異達2倍。天然林落葉中氮與磷的濃度在颱風時期顯著高於非颱風時期,此應與颱風時期營養未充分再吸收有關。研究結果亦顯示降雨量比風速更能預測颱風造成的枯落物量。在中國東南部這兩類森林枯落物的高峰均在乾季,但本研究中颱風時期的枯落物量高於乾季,顯示在颱風頻繁的地區颱風擾動主導了枯落物在時間上的變動情形。全球氣候變遷正改變熱帶氣旋的頻率與強度,因此充分了解颱風與枯落物變動間的關係,為評估氣候變遷將如何影響生態系營養循環所不可或缺的一環。

There is a growing need to understand, and ultimately manage, carbon storage by forest ecosystems. Broad-leaved evergreen forests of Taiwan provide an outstanding opportunity to examine factors that regulate ecosystem carbon storage. We utilized data from three Taiwan Forest Dynamics Plots (FS, LHC, and PTY) in which every tree is identified, measured, tagged and mapped, to examine factors regulating carbon storage as estimated from aboveground biomass. Allometric equations were used to estimate the aboveground biomass of each tree, and a model building procedure was used to examine relationships between plot-level aboveground biomass (AGB; Mg/ha) and a suite of topographic and biotic factors. We found that our study sites have AGB values comparable to some of the most carbon dense forests in the world. Across all three sites, maximum biomass was contained in the taxonomic families Fagaceae, Lauraceae and Theaceae. In the FS site, we identified slope convexity (P = 0.03) and elevation (P < 0.001) as topographic predictors of AGB and found that maximum AGB was found in topographically flat areas. In FS, stem density (P < 0.001) was a significant biotic predictor of AGB and the maxima occurred at intermediate densities. In LHC, we found that convexity (P < 0.001) and slope (P < 0.001) were significantly related to AGB which was maximized along a topographic ridge in the plot. Species richness (P < 0.001) was a significant biotic predictor of AGB in LHC, and the relationship indicated slightly higher AGB at higher levels of species richness. The only significant factor related to AGB in PTY was species richness (P = 0.02). Further work is needed to seek a mechanistic understanding of topographic factors and species richness as drivers of carbon storage in forests.

BACKGROUND: Tea plants are always cultivated in acid soils in hilly regions and their growth can be dependent on to soluble aluminium (Al). The mechanism of Al detoxification and the influence of Al on phenolic compounds (i.e. catechin) in the roots of tea plants has remained obscure. This study aimed to investigate the influence of Al changes on the concentrations of phenolic substances in tea plants through hydroponic experiments. RESULTS: Tea plants were cultivated in nutrient solution containing 1.5 and 2.5 mmol L−1 Al, and these treatments enhanced the growth of new buds and roots. Aluminium stimulated the uptake of Ca, Mg, K and Mn, whereas the uptake of Fe, Cu and Zn was retarded. Moreover, total phenol concentrations in tea plant tissues increased with increasing Al concentrations. In general, catechin concentrations in leaves increased with increasing Al concentrations in the hydroponic experiments. High correlation coefficients were obtained between Al and (−)-ECG (r2 = 0.85, P < 0.01) and between Al and total phenols (r2 = 0.92, P < 0.01). CONCLUSIONS: The Al concentration in tea plants indeed increases catechin concentrations and plays an important role in the growth of tea plants. Copyright © 2011 Society of Chemical Industry

Strong tropical storms are known to affect forest structure, composition, and nutrient cycles in both tropical and temperate regions, although our understanding of these effects disproportionally comes from regions experiencing much lower cyclone frequency than many forests in the Northwest Pacific. We summarized the effects of typhoons on forest dynamics at Fushan Experimental Forest (FEF) in northeastern Taiwan, which averages 0.49 major typhoons annually, and compared their resistance and resilience to those of forests in other regions. Typhoons cause remarkably few tree falls at FEF; multiple typhoons in 1994 felled only 1.4% of canopy trees, demonstrating high structural resistance. The most important effect of typhoons in this ecosystem is defoliation, which maintains high understory light levels and enhances heterogeneity, sustaining diversity without large canopy gaps. The vulnerability of taller trees to being blown down has resulted in the short-stature FEF (mean canopy height is 10.2 m). As the FEF is P-limited and a large fraction of total annual P export occurs during typhoons, these storms may have the effect of reducing productivity over time. DIN and K+ export only remain elevated for days at FEF, in contrast to the several years observed in Puerto Rico. High resilience is also evident in the rapid recovery of leaf area following typhoons. Heavy defoliation and slow decomposition are among the processes responsible for the high resistance and resilience of FEF to typhoon disturbance. These key structural features may emerge in other forest ecosystems if the frequency of major storms increases with climate change.

Polyphenols (catechins) are vital biomolecules in tea plants, Camellia sinensis , which are well adapted to acid soils with high availability of phytotoxic Al species. Since the mechanism of Al resistance in tea plants by catechin remains obscure, this study investigates the influence of catechin on aluminum transformation. It is found that the pH of the suspensions decreased with aging. The hydrolytic precipitates of Al were subjected to surface area, X-ray diffraction (XRD), Fourier-transform infrared absorption spectroscopy (FT-IR), transmission electron microscopy (TEM), thermal, and chemical analyses. At the initial Al concentration of 2 × 10 − 2 M sample, in the absence of catechin for 180-d aging, only 59.7% of the Al is remained in the filtrate, including readily, moderately extractable and nonextractable fractions. However, in the presence of catechin, above 70.5% of the Al is present in the filtrate. The readily, moderately extractable and nonextractable Al fractions with 8-quinolinolate method are decreased with increasing concentrations of catechin after 180-d aging. Specific surface area of the Al precipitates increases with increasing concentrations of catechin. In the absence of catechin, the Al precipitates with prolonged aging are mostly crystalline gibbsite. X-ray diffraction analysis and TEM observations also show the structural distortion within the hydrolytic precipitates of Al in the presence of catechin. FT-IR spectra show that catechin substantially inhibits the formation of crystalline aluminum hydroxides. X-ray noncrystalline to poor-ordered hydrolytic reaction products of Al are formed in the presence of catechin. TEM images also show that the Al precipitates form under the perturbation of catechin are fine, shapeless and hollow colloids that are deformed and aggregated. Thermal analysis shows that the hydrolytic reaction products of Al lost their structural water gradually when catechin concentration is raised from 0 M (control) to 4.0 × 10 − 3 M, indicating that greater structural disorder occurs with increasing catechin concentration in the Al systems.

Climate and litter quality are primary drivers of terrestrial decomposition and, based on evidence from multisite experiments at regional and global scales, are universally factored into global decomposition models. In contrast, soil animals are considered key regulators of decomposition at local scales but their role at larger scales is unresolved. Soil animals are consequently excluded from global models of organic mineralization processes. Incomplete assessment of the roles of soil animals stems from the difficulties of manipulating invertebrate animals experimentally across large geographic gradients. This is compounded by deficient or inconsistent taxonomy. We report a global decomposition experiment to assess the importance of soil animals in C mineralization, in which a common grass litter substrate was exposed to natural decomposition in either control or reduced animal treatments across 30 sites distributed from 43°S to 68°N on six continents. Animals in the mesofaunal size range were recovered from the litter by Tullgren extraction and identified to common specifications, mostly at the ordinal level. The design of the trials enabled faunal contribution to be evaluated against abiotic parameters between sites. Soil animals increase decomposition rates in temperate and wet tropical climates, but have neutral effects where temperature or moisture constrain biological activity. Our findings highlight that faunal influences on decomposition are dependent on prevailing climatic conditions. We conclude that (1) inclusion of soil animals will improve the predictive capabilities of region- or biome-scale decomposition models, (2) soil animal influences on decomposition are important at the regional scale when attempting to predict global change scenarios, and (3) the statistical relationship between decomposition rates and climate, at the global scale, is robust against changes in soil faunal abundance and diversity.

The aims of this study were to make use of organo-clays (i.e., Cloisite-10A, Cloisite-15A, Cloisite-30B and Cloisite-93A), to remove p -nitrophenol, phenol and aniline of organic pollutants. The organo-clays were characterized by X-ray diffraction (XRD). Sorption isotherm, kinetic and pH effect of p -nitrophenol, phenol and aniline sorbed by four organo-clays were evaluated. The d -spacings (0 0 1) of the XRD peak of Cloisite-10A, Cloisite-15A, Cloisite-30B and Cloisite-93A are 1.98, 2.76, 1.93 and 2.64 nm, respectively. The d (0 0 1)-spacings of XRD indicated that these p -nitropheno, phenol and aniline could penetrate into the interlayer of clays and expand the d (0 0 1)-spacings. The linear sorption isotherm of constant partition was employed to describe the sorption isotherms of phenols sorbed by organo-clays through hydrophobic–hydrophobic chemical reactions. The parabolic diffusion and power-function of kinetic models were employed to describe properly the kinetic experiments. The rate limiting step of the p -nitrophenol sorption reactions on organo-clays were diffusion-controlled processes (i.e., 15A, 30B, 93A) and chemical-controlled process for 10A organo-clays. The pre-exponential factor of the p -nitrophenol sorbed by four organo-clays showed the trend as follows: 10A > 30B > 93A > 15A. The efficiency of these organo-clays in removing phenol compounds in water treatments merit further study.

Recent studies indicate that, especially in epiphytes, plant size has a strong influence on the ecophysiology of individual leaves of a plant. Extensive data sets that address this phenomenon, however, are limited to a few taxa of flowering plants. It was the purpose of this study to examine numerous physiological parameters in individuals of varying sizes of Asplenium nidus, a widespread epiphytic tropical fern, in a rain forest in northeastern Taiwan. Although stomatal dimensions and frond thickness did not vary with plant size, frond stomatal densities were higher in larger plants. Frond elemental concentration did not vary with plant size for nitrogen, magnesium, phosphorus, and sodium, while the concentrations of carbon, calcium, and potassium changed with plant size, though in different ways. The osmotic concentration of liquid expressed from the fronds did not change with plant size, nor did chlorophyll concentrations and chlorophyll a/b ratio. Fronds excised from smaller plants contained more wate...

The litterfall in a subtropical broadleaf forest within the Fushan Experimental Forest in northeastern Taiwan was monitored for 9 years. Mean annual litterfall was very sensitive to typhoon frequency and intensity, ranging from 3 to 11 Mg·ha–1·year–1. Litterfall was significantly higher in years with strong typhoons than in years without typhoons, and the number of strong typhoons explained 82% of interannual variation in litterfall. Nutrient-use efficiency (dry mass/nutrients in litterfall) was high for N, but low for P compared with other tropical forests. This result supports the idea that the study forest is P limited but not N limited. Nutrient loss via litterfall represents a large percentage of aboveground biomass, especially during years with strong typhoons (e.g., 19%–41%, 15%–40%, 5%–12%, for N, P, and K, respectively). Forests that experience infrequent wind disturbance (e.g., temperate or boreal forests) can gradually regain any lost nutrients prior to the next disturbance; this is different from the situation observed in the Fushan Experimental Forest. At Fu-shan the pattern of not responding to typhoons with a flush of new growth appears to be an adaptation to the frequency with which there are multiple typhoons affecting the forest in a single year. Nutrient loss in litterfall caused by frequent typhoon disturbances appears to limit tree growth and contributes to the very low canopy height of the Fushan Experimental Forest.

In 1996 and 1997 we examined the effects of typhoon disturbance on the understory light environment and sapling dynamics of the Fu-shan Experimental Forest, a subtropical rain forest in northeastern Taiwan. Mean understory light levels were approximately 30% of those in the open immediately following the two 1996 typhoons which affected the forest, yet in 1997, following two more typhoons, mean understory light levels were 10%–20% of those in the open. The decline of understory light levels to those present prior to the typhoons was more rapid in 1996 than in 1997, even though the two typhoons in 1996 were more intense than those in 1997. This difference might be the result of the timing of the typhoons. In 1996 the typhoons occurred earlier in the growing season, before August 1 rather than the middle and end of August in 1997. The regular defoliation caused by the frequent typhoons that impact Fu-shan (average of 1.4 per year) and the low stature of the forest (mean canopy height of 10.6 m), results in much higher light levels beneath the canopy (9%–30% of levels in the open) than those found in most tropical and temperate forests. As a result, understory light levels are not limiting the distribution of canopy tree saplings within the forest and there is no evidence that canopy gaps play an important role in canopy tree regeneration within the Fu-shan Experiment Forest. This is in contrast with the pattern reported for some tropical forests. With frequent typhoons impacting northeastern Taiwan, the forests of this region are perpetually recovering from wind disturbances.

We examined base cation leaching from the canopy of a subtropical rainforest in northeastern Taiwan. The forest is characterized by extremely low levels of base cations in both canopy vegetation and in the soils. The rates of canopy leaching of K+, Ca2+, and Mg2+ were very high, representing up to 30, 35, and 190%, respectively, of the amount stored in leaves. The rate of H+ retention in the canopy was close to the rate of base cation leaching, suggesting that cation leaching is neutralizing acid precipitation. The subtropical forest studied leached cations from the canopy throughout the year, unlike temperate deciduous forests, which are physiologically inert in the winter. The forest canopy of the subtropical forest we studied is impacted by acid deposition and fog throughout the winter because of frequent rainfall and high relative humidity. This continuous exposure to acid precipitation could cause more intense negative effects on the canopy of subtropical forests as compared with temperate forests exposed to similar pollution loads. We suggest that the low base status of subtropical forests growing on low base status soils may make them very vulnerable to the negative effects of air pollution.

Tea plants are always cultivated in acid soils in hilly regions and their growth can be dependent on to soluble aluminium (Al). The mechanism of Al detoxification and the influence of Al on phenolic compounds (i.e. catechin) in the roots of tea plants has remained obscure. This study aimed to investigate the influence of Al changes on the concentrations of phenolic substances in tea plants through hydroponic experiments.Tea plants were cultivated in nutrient solution containing 1.5 and 2.5 mmol L(-1) Al, and these treatments enhanced the growth of new buds and roots. Aluminium stimulated the uptake of Ca, Mg, K and Mn, whereas the uptake of Fe, Cu and Zn was retarded. Moreover, total phenol concentrations in tea plant tissues increased with increasing Al concentrations. In general, catechin concentrations in leaves increased with increasing Al concentrations in the hydroponic experiments. High correlation coefficients were obtained between Al and (-)-ECG (r(2) = 0.85, P0.01) and between Al and total phenols (r(2) = 0.92, P0.01).The Al concentration in tea plants indeed increases catechin concentrations and plays an important role in the growth of tea plants.

This study investigates the species of As and Pb (beudantite) residues present in the seriously contaminated agricultural rice soils of the Guandu Plain. Two pedons in the Guandu Plain agricultural soils, each pedon separated into five horizons (each of 20 cm) were collected for this study. Soil samples were packed into a column for leaching with simulated acid rains. Soil pH ranged from 5.1 to 7.1 with high base saturation. Soils can be classified as clay loam, mixed, thermic, Typic or Umbric Albaqualfs. The XRD analysis indicated the beudantite particles are present in clay fractions, showing high concentrations of As and Pb. This is because of 50-100 years ago irrigation water was introduced from Huang Gang Creek of hot springs containing high concentrations of As and Pb. Only low concentrations of As and Pb can be leached out with simulated acid rains (i.e., pHs 2 and 4), even through 40 pore volumes of leaching experiments. The sequential extraction experiments resulted in the high portions of As and Pb remaining in the amorphous, Fe and Al oxyhydroxides and residual fractions. Thus, the remediation of As and Pb in this agricultural rice paddy soils merits further study.