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Decomposition is a key ecosystem function, and the rate of decomposition in forests affects their carbon storage potentials. Processes and factors determining leaf litter decomposition rates in dry-land and temperate forests are well understood, but these are generally poorly studied in tropical wetland forests, especially freshwater swamp forests (FSF). The home-field advantage (HFA) hypothesis predicts that soil microbes specialize in decomposing leaf litter produced by the tree species in their immediate vicinity. However, empirical support for the HFA is equivocal, and the HFA has never been tested in the highly heterogeneous and biodiverse ecosystems of tropical FSFs. We collected leaf litter from swamp and non-swamp tree species in a tropical FSF in Singapore and monitored the decomposition rates of these in swamp and non-swamp plots for a period of eight months. Leaf litter decomposed 3.7 times more slowly in swamp plots. Leaf litter from swamp tree species were significantly poorer in quality (higher C:N ratio) than those of non-swamp FSF tree species, but this had only a weak effect on decomposition rates. There was also only weak evidence for the HFA and only in non-swamp conditions. Our results show that while the leaf litter of tropical FSF swamp and non-swamp tree species differ significantly in chemical traits, litter decomposition rate is ultimately determined by local abiotic conditions, such as hydrology. Additionally, the high FSF tree diversity may prevent decomposer communities from specializing on any group of leaf litter types and thus limit the extent of HFA observed in such heterogeneous forests.

Background: While many reviews have been performed to attempt to provide conclusive evidence regarding the outcomes of mesenchymal stem cells (MSCs) in osteoarthritis treatment, the evidence for MSC treatment in osteoarthritis remains contentious, as these reviews have been limited by the heterogeneous evidence available. Purpose: To pool the results of treatment using intra-articular injections of MSCs without any adjuvant therapies for osteoarthritis. Study Design: Systematic review and meta-analysis. Methods: The review was conducted in accordance with the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. All clinical trials of level 1 or 2 evidence that reported clinical outcomes of patients with osteoarthritis of the knees treated using intra-articular injections of MSCs without any adjuvant therapies were included. Results: A total of 19 studies with 440 knees were included. All studies reported an improvement in the outcomes after intervention. The standardized mean differences (SMDs) for the visual analog scale (VAS) for pain at rest and upon exertion were –1.48 (95% CI, –1.85 to –1.11) and –2.25 (95% CI, –2.64 to –1.85), respectively. The SMDs for the total Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) and total Knee injury and Osteoarthritis Outcome Score were –1.19 (95% CI, –1.53 to –0.84) and 0.88 (95% CI, 0.66-1.10), respectively. Only the source of MSCs and whether the MSCs were cultured or uncultured were clinically important and statistically significant moderators of the treatment outcome. The use of bone marrow MSCs reduced the VAS for pain by 1.50 (95% CI, 0.04-2.96; P = .04) and reduced the total WOMAC by 23.2 (95% CI, 10.0-36.4; P < .01) as compared with adipose MSCs. The use of cultured MSCs reduced the VAS for pain by 2.19 (95% CI, 0.57-3.81; P < .01) and reduced the total WOMAC by 14.4 (95% CI, 1.21-27.5; P = .03) as compared with uncultured MSCs. Conclusion: Intra-articular injections of MSCs without any adjuvant therapies improves pain and function for osteoarthritis. Significantly better outcomes were obtained with the use of bone marrow MSCs as compared with adipose MSCs and with the use of cultured MSCs as opposed to uncultured MSCs.

Fire represents a mainstay for rural communities managing tropical landscapes. However, increasing uncontrolled fires in tropical landscapes because of land use and climate change pose a major threat to livelihoods, public health, and ecosystems. Peatlands in Southeast Asia are one such example of tropical landscapes that experience high flammability due to clearance of forests and excessive drainage for agriculture and forestry. The degradation of tropical peatland ecosystems increases their susceptibility to landscapes fires, which in turn increase the vulnerability of people and peatland conditions to future fires. To identify locations of tropical peatlands and surrounding communities that are vulnerable to fires, we conducted a socio-ecological vulnerability assessment and mapped the socio-ecological vulnerability of tropical peatlands to fires. We used an inductive approach to conceptualize and operationalize vulnerability and its associated dimensions of exposure, sensitivity, and adaptive capacity through empirical case studies in the literature, with a focus on tropical peatlands and fires in Indonesia. We present preliminary results of our mapped social and ecological vulnerability of Indonesia’s tropical peatlands to peat landscape fires. This would allow policymakers to identify places which display both high ecological and social vulnerability to fires and channel aid and mitigation efforts where they are most urgently needed.

Re-completion operations with hydraulic workover units (HWO) have been carried out extensively within the industry, showcasing the high level of efficiency and compact footprint offered by this type of equipment. In an offshore environment, with small jacket platforms, the benefits of the use of said equipment are much more relevant and significant in terms of overall positive impact on the projects. However, re-completions with control lines and sensors, or usually referred to as smart-well re-completions had not been performed with HWO units in the past. Having stated this premise, the challenge of performing the first smart well re-completion with an HWO unit presented itself with an additional hurdle, which was the fact that the tubing and control lines had to be cut instead of being able to pull from the production packer. This paper showcases the planning, execution, and results of re-completing a well in one of the top offshore gas-producing platforms in the country. Due to a smaller footprint and the advantage to continue the production from neighboring wells simultaneously, the HWO unit was selected as it represented the best overall value for the customer. The job was performed with additional support from a dynamically positioned (DP-2) vessel and a portable crane for efficient rig up and support during the intervention.

It has been known for decades that the application of pulsed direct current can significantly enhance the formability of metals. However, the detailed mechanisms of this effect have been difficult to separate from simple Joule heating. Here, we study the electroplastic deformation of Ti–Al (7 at.% Al), an alloy that is uniquely suited for uncoupling this behaviour because, contrary to most metals, it has inherently lower ductility at higher temperature. We find that during mechanical deformation, electropulsing enhances cross-slip, producing a wavy dislocation morphology, and enhances twinning, which is similar to what occurs during cryogenic deformation. As a consequence, dislocations are prevented from localizing into planar slip bands that would lead to the early failure of the alloy under tension. Our results demonstrate that this macroscopic electroplastic behaviour originates from defect-level microstructural reconfiguration that cannot be rationalized by simple Joule heating. Transmission electron microscopy reveals the electroplastic effects in a Ti–Al alloy, which can be uncoupled from Joule heating effects. Electropulsing during deformation enhances wavy slip of dislocations, reconfiguring the dislocation pattern, and hence increases the ductility.

Extinction is a key issue in the assessment of global biodiversity. However, many extinction rate measures do not account for species that went extinct before they could be discovered. The highly developed island city-state of Singapore has one of the best-documented tropical floras in the world. This allowed us to estimate the total rate of floristic extinctions in Singapore since 1822 after accounting for sampling effort and crypto extinctions by collating herbaria records. Our database comprised 34,224 specimens from 2076 native species, of which 464 species (22%) were considered nationally extinct. We assumed that undiscovered species had the same annual per-species extinction rates as discovered species and that no undiscovered species remained extant. With classical and Bayesian algorithms, we estimated that 304 (95% confidence interval, 213-414) and 412 (95% credible interval, 313-534) additional species went extinct before they could be discovered, respectively; corresponding total extinction rate estimates were 32% and 35% (range 30-38%). We detected violations of our 2 assumptions that could cause our extinction estimates, particularly the absolute numbers, to be biased downward. Thus, our estimates should be treated as lower bounds. Our results illustrate the possible magnitudes of plant extirpations that can be expected in the tropics as development continues.Tasa de Extinción de Plantas Descubiertas y No Descubiertas en Singapur Resumen La extinción es un tema importante para la valoración de la biodiversidad global. Sin embargo, muchas medidas de la tasa de extinción no consideran a las especies que se extinguieron antes de que pudieran ser descubiertas. Singapur, la ciudad-estado isleña altamente desarrollada, tiene una de las floras mejor documentadas del mundo. Esto nos permitió estimar la tasa total de las extinciones florísticas en Singapur desde 1822 después de considerar el esfuerzo de muestreo y las criptoextinciones cuando recopilamos los registros de herbarios. Nuestra base de datos incluyó 34,224 especímenes de unas 2,076 especies nativas, de las cuales 464 especies (22%) estaban consideradas como extintas a nivel nacional. Asumimos que las especies no descubiertas tuvieron la misma tasa anual de extinción por especie que las especies descubiertas y que ninguna especie no descubierta permanecía en existencia. Con algoritmos clásicos y bayesianos, respectivamente, estimamos que 304 (95% IC 213-414) y 412 (95% IC 313-534) especies adicionales se extinguieron antes de que fueran descubiertas; las estimaciones correspondientes de la tasa de extinción total fueron 32% y 35% (rango de 30-38%). Detectamos violaciones en nuestras dos suposiciones que podrían causar que nuestras estimaciones de extinción, particularmente los números absolutos, tuvieran un sesgo hacia abajo. Por lo tanto, nuestras estimaciones deberían ser tratadas como límites inferiores. Nuestros resultados ilustran las magnitudes posibles de las extirpaciones de plantas que pueden esperarse en los trópicos conforme el desarrollo continúa.物种灭绝是全球生物多样性评估的一个关键问题。然而, 许多灭绝率估计中并没有考虑到那些在被发现之前就已经灭绝的物种。高度发达的岛国新加坡拥有世界上记载最完整的热带植物群, 这使得我们能够通过整理草本植物记录来统计采样工作量和隐秘的灭绝事件, 以估计新加坡自1822 年以来植物灭绝的总速率。本研究的数据库包括来自 2076 个本地物种的 34, 224 个标本, 其中有 464 个物种 (22%) 被认为在全国范围内灭绝。我们假设未被发现的物种年均灭绝率与已发现物种相同, 且已没有未被发现的现存物种。利用经典算法和贝叶斯算法, 我们分别估计出 304 个 (95% 置信区间为 213 - 414) 和 412 个 (95% 可信区间为 313 - 534) 新物种在被发现之前就已经灭绝; 相应的总灭绝率估计分别为 32% 和 35% (范围为 30 - 38%) 。我们还发现存在违反上述两个假设的情况, 这可能导致我们对灭绝情况的估计值偏低, 特别是对绝对数值的估计。因此, 我们对灭绝情况的估计值应被视为下限。本研究表明, 随着热带地区的发展, 植物灭绝的规模可能会不断扩大。【翻译:胡怡思;审校:聂永刚】.

In this study, the microstructural characteristics and mechanical properties of Ti-1.0Fe alloy with equiaxed α + β microstructures were investigated in detail. Four different equiaxed α + β microstructures with β phase fraction ranging from 3 to 26 pct were obtained by hot deforming the martensite initial microstructure in α + β two-phase region with different deformation temperatures and cooling rates. The average nano-hardness of β grains was found to be much larger than that of α grains, which was attributed to the higher Fe concentration as well as nano-sized athermal ω precipitates inside the β grains. As a result, plastic strain partitioning occurred between the two phases during the tensile deformation, where the plastic strain within the soft α grains was much larger. With the increase of the β phase fraction, both yield and tensile strength of the samples increased, while at the same time, the total elongation gradually decreased. Most of the micro-cracks formed at the α/β interphase boundaries and propagated across the narrowest part of β phase. In the sample with the largest β phase fraction (26 pct), strain-induced β to α′ phase transformation occurred at the expense of initial athermal ω precipitates during the tensile deformation. This resulted into local nano-hardness variations between transformed and un-transformed β areas. Consequently, much more micro-cracks formed in this sample either at the boundaries between transformed and un-transformed β areas, or around the strain-induced α′ phase with a plate-like morphology. This explained the premature fracture shortly after necking in the sample with the largest β phase fraction.

With the development of switching power supplies, miniaturization and high efficiency become hot research issues, and decreasing high-frequency losses is an effective method to achieve it. In this article, the effect of different calcination temperature on the power losses of MnZn ferrites at high frequency (500 kHz) over a broad temperature range is reported. The MnZn ferrites samples were prepared by ceramic process and the effect of calcination temperature was analyzed. The raw materials were calcined at 775 ℃, 800 ℃, 825 ℃, 850 ℃, 875℃, 900 ℃, 925 ℃ and 950 ℃, and the regular fluctuations of particle size (as-calcined), density (as-sintered) and magnetic properties are presented in this work. It is shown that the samples calcined at 850 ℃ exhibit optimal microstructure and magnetic properties. The newly developed MnZn ferrites are characterized by sintered density of 4.61 g/cm³, initial permeability of 1223 (10 kHz/0.1 mT/25 ℃), saturation magnetic flux density of 488 mT (10 kHz/1200 A/m/25 ℃) and power losses of 68 mW/cm³ (500 kHz/50 mT/100 ℃).

Growth in individual size or biomass is a key demographic component in population models, with wide-ranging applications from quantifying species performance across abiotic or biotic conditions to assessing landscape-level dynamics under global change. In forest ecology, the responses of tree growth to biotic interactions are widely held to be crucial for understanding forest diversity, function, and structure. To date, most studies on plant–plant interactions only examine the additive competitive or facilitative interactions between species pairs; however, there is increasing evidence of non-additive, higher-order interactions (HOIs) impacting species demographic rates. When HOIs are present, the dynamics of a multi-species community cannot be fully understood or accurately predicted solely from pairwise outcomes because of how additional species ‘interfere’ with the direct, pairwise interactions. Such HOIs should be particularly prevalent where species show nonlinear functional responses to resource availability and resource-acquisition traits themselves are density dependent. With this in mind, we used data from a tropical secondary forest—a system that fulfills both of these conditions—to build a ontogenetic diameter-growth model for individuals across ten woody-plant species. We allowed both direct and indirect interactions within communities to influence the species-specific growth parameters in a generalized Lotka–Volterra model. Specifically, indirect interactions entered the model as higher-order quadratic terms, i.e. non-additive effects of conspecific and heterospecific neighbour size on the focal individual’s growth. For the whole community and for four out of ten focal species, the model that included HOIs had more statistical support than the model that included only direct interactions, despite the former containing a far greater number of parameters. HOIs had comparable effect sizes to direct interactions, and tended to further reduce the diameter growth rates of most species beyond what direct interactions had already reduced. In a simulation of successional stand dynamics, the inclusion of HOIs lead to rank swaps in species’ diameter hierarchies, even when community-level size distributions remained qualitatively similar. Our study highlights the implications, and discusses possible mechanisms, of non-additive density dependence in highly diverse and light-competitive tropical forests.

False lumen thrombosis (FLT) in typeBaortic dissection has been associated with the progression of dissection and treatment outcome. Existing computational models mostly assume rigid wall behavior which ignores the effect of flap motion on flow and thrombus formation within the FL. In this study, we have combined a fully coupled fluid–structure interaction (FSI) approach with a shear-driven thrombosis model described by a series of convection–diffusion reaction equations. The integrated FSI-thrombosis model has been applied to an idealized dissection geometry to investigate the interaction between vessel wall motion and growing thrombus. Our simulation results show that wall compliance and flap motion can influence the progression of FLT. The main difference between the rigid and FSI models is the continuous development of vortices near the tears caused by drastic flap motion up to 4.45 mm. Flap-induced high shear stress and shear rates around tears help to transport activated platelets further to the neighboring region, thus speeding up thrombus formation during the accelerated phase in the FSI models. Reducing flap mobility by increasing the Young’s modulus of the flap slows down the thrombus growth. Compared to the rigid model, the predicted thrombus volume is 25% larger using the FSI-thrombosis model with a relatively mobile flap. Furthermore, our FSI-thrombosis model can capture the gradual effect of thrombus growth on the flow field, leading to flow obstruction in the FL, increased blood viscosity and reduced flap motion. This model is a step closer toward simulating realistic thrombus growth in aortic dissection, by taking into account the effect of intimal flap and vessel wall motion.