Biodiversity shapes tree species aggregations in tropical forests

Spatial patterns of conspecific trees are considered as the consequences of biological interactions and environmental influences. They also reflect species interactions in plant communities. However, biological attributes are often neglected while deliberating the factors shaping species distributions. As rising attentions are paid to spatial patterns of tropical forest trees, we noticed that seven Center of Tropical Forest Sites and four Forest Dynamic Plots in Asia and America have presented analogously high proportions of species with aggregated conspecific individuals coincidently. This phenomenon is distinctive and repudiates fundamental ecology hypotheses which suggested dispersed distributions of conspecific tropical trees due to intensive density and natural enemy pressures in tropical forests. We believe that similar aggregation patterns shared by these tropical forests implies the existence of structuring forces in biogeographical scale instead of habitat heterogeneity in local community scales as scientists have considered. To approach the factors contributing to this cross-continent spatial pattern of trees, we obtained and reviewed ecosystem attributes, including topography, temperature, precipitation, biodiversity, density, and biomass, of these forests. Here we show that the proportions of aggregated species are actually constants independent of any ecosystem attributes regardless the nature of these tropical forests. However, local biodiversity are the major factor determining the number of aggregated species and the aggregation of large individuals of these forests. Aggregation of large trees declines along rising biodiversity, while the numbers of aggregated species increase permanently along lifting biodiversity. We propose a possible equilibrium and saturated status of the tropical forests in accommodating aggregated species. Furthermore, the tight correlations of biodiversity and species aggregation strongly imply the importance of overlooked biological interactions in shaping the spatial patterns in the tropical forests

Energy-Efficient Non-Orthogonal Transmission under Reliability and Finite Blocklength Constraints

This paper investigates an energy-efficient non-orthogonal transmission design problem for two downlink receivers that have strict reliability and finite blocklength (latency) constraints. The Shannon capacity formula widely used in traditional designs needs the assumption of infinite blocklength and thus is no longer appropriate. We adopt the newly finite blocklength coding capacity formula for explicitly specifying the trade-off between reliability and code blocklength. However, conventional successive interference cancellation (SIC) may become infeasible due to heterogeneous blocklengths. We thus consider several scenarios with different channel conditions and with/without SIC. By carefully examining the problem structure, we present in closed-form the optimal power and code blocklength for energy-efficient transmissions. Simulation results provide interesting insights into conditions for which non-orthogonal transmission is more energy efficient than the orthogonal transmission such as TDMA.Comment: accepted by IEEE GlobeCom workshop on URLLC, 201

Effects of orthographic consistency and homophone density on Chinese spoken word recognition

Studies of alphabetic language have shown that orthographic knowledge influences phonological processing during spoken word recognition. This study utilized the Event-Related Potentials (ERPs) to differentiate two types of phonology-to-orthography (P-to-O) mapping consistencies in Chinese, namely homophone density and orthographic consistency. The ERP data revealed an orthographic consistency effect in the frontal-centrally distributed N400, and a homophone density effect in central-posteriorly distributed late positive component (LPC). Further source analyses using the standardized low-resolution electromagnetic tomography (sLORETA) demonstrated that the orthographic effect was not only localized in the frontal and temporal-parietal regions for phonological processing, but also in the posterior visual cortex for orthographic processing, while the homophone density effect was found in middle temporal gyrus for lexical-semantic selection, and in the temporal-occipital junction for orthographic processing. These results suggest that orthographic information not only shapes the nature of phonological representations, but may also be activated during on-line spoken word recognition

The Application of Six Sigma Approach in Construction : A Case Study for Improving Precast Production Management

Six Sigma has been developed in the 1980s at Motorola; this approach is now extensively ap-plied in the manufacturing and other industries for improving productivity and profitability. In Taiwan, after 921 earthquake in 1999 and huge floods in 2009, the construction industry have realized that the importance of construction quality and harmony with the environment. The Six Sigma takes attention to the quality that customers concerned and also contribute to achieving efficiency and reduce costs. By the way, the thinking of Six Sigma approach should also be applied in the construction industry. Therefore, this paper will take the Six Sigma approach into the practice of precast construction management

The feedback consistency effect in Chinese character recognition:evidence from a psycholinguistic norm

Researchers have demonstrated the importance of phonology in literacy acquisition and in visual word recognition. For example, the spelling-to-sound consistency effect has been observed in visual word recognition tasks, in which the naming responses are faster and more accurate for words with the same letters that also have the same pronunciation (e.g. -ean is always pronounced /in/, as in lean, dean, and bean). In addition, some studies have reported a much less intuitive feedback consistency effect when a rime can be spelled in different ways (e.g. /ip/ in heap and deep) in lexical decision tasks. Such findings suggest that, with activation flowing back and forth between orthographic and phonological units during word processing, any inconsistency in the mappings between orthography and phonology should weaken the stability of the feedback loop, and, thus, should delay recognition. However, several studies have failed to show reliable feedback consistency in printed word recognition. One possible reason for this is that the feedback consistency is naturally confounded with many other variables, such as orthographic neighborhood or bigram frequency, as these variables are difficult to tease apart. Furthermore, there are challenges in designing factorial experiments that perfectly balance lexical stimuli on all factors besides feedback consistency. This study aims to examine the feedback consistency effect in reading Chinese characters by using a normative data of 3,423 Chinese phonograms. We collected the lexical decision time from 180 college students. A linear mixed model analysis was used to examine the feedback consistency effect by taking into account additional properties that may be confounded with feedback consistency, including character frequency, number of strokes, phonetic combinability, semantic combinability, semantic ambiguity, phonetic consistency, noun-to-verb ratios, and morphological boundedness. Some typical effects were observed, such as the more frequent and familiar a character, the faster one can decide it is a real character. More importantly, the linear mixed model analysis revealed a significant feedback consistency effect while controlling for other factors, which indicated that the pronunciation of phonograms might accommodate the organization of Chinese orthographic representation. Our study disentangled the feedback consistency from the many other factors, and supports the view that phonological activation would reverberate to orthographic representation in visual word recognition

Exploring Online Repeat Purchase Intentions: The Role of Habit

By focusing on online stores, this study investigates the repeat purchase intention of experienced online buyers. Prior research on online behavior continuance models perceived usefulness, trust, satisfaction, and perceived value as the major determinants of continued adoption or loyalty, overlooking the important role of habit. Building on previous work in other disciplines, we define habit in the context of online shopping as the extent to which buyers tend to shop online automatically because of learning. Using recent work on the continued usage of IS (IS continuance) and repeat purchase, we have developed a model suggesting that repeat purchase intention is not only a consequence of trust and switching cost, but also of habit. In particular, in our research model, we propose that online shopping habit moderate the influence of trust such that its importance in determining repeat purchase intention decreases as the online shopping behavior takes on a more habitual nature. Integrating prior research on habit, IS continuance, and repeat purchase further, we suggest how antecedents of repeat purchase intention relate to drivers of habitualization. Data collected from 462 of Yahoo!Kimo shopping center’s customers provide strong support for the research model. Results indicate that higher level of habit deflated trust’s effect on repeat purchase intention. The data also show that satisfaction and familiarity are key to habit formation and thus relevant in the context of online repeat purchase

Acute Paraparesis Caused by a Giant Cell Tumor of the Thoracic Spine

AbstractGiant cell tumor (GCT) is a benign but locally aggressive skeletal neoplasm of young adults. GCT located in the spine is relatively rare and may need a combination of surgical and adjunctive therapies. Here we present a patient who had intermittent thoracic back pain for two weeks and experienced an acute episode of decreased muscle power of both lower limbs. Magnetic resonance (MR) imaging examinations of the thoracic spine revealed that the patient had severe spinal canal compression caused by pathological fracture due to a tumor within the seventh thoracic vertebra. She underwent an emergent surgical intervention for total removal of the tumor and spinal reconstruction with autologous rib grafts and instruments. Postoperatively, the patient made an uneventful recovery of muscle power of bilateral lower limbs. She subsequently received adjuvant radiotherapy. In a follow-up period of 36 months, the patient had no clinical or radiological evidence of tumor recurrence. Even though spinal location for GCT is a rare event, it should be included in the differential diagnosis in patients with osteolytic lesions or pathological fractures of the vertebra, especially in young female patients sustaining no trauma who had a clinical history of persistent low back pain

Preparation and Characterization of Carrot Nanocellulose and Ethylene/Vinyl Acetate Copolymer-Based Green Composites

This study aims to investigate the effect of nanocellulose on the properties and physical foaming of ethylene/vinyl acetate (EVA) copolymer. The nanocellulose is prepared from waste carrot residue using the 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO) oxidation method (CT) and is further modified through suspension polymerization of methyl methacrylate (MMA) monomer (CM). The obtained nanocellulose samples (CT or CM) are added to EVA to create a series of nanocomposites. Moreover, the EVA and CM/EVA composite were further foamed using supercritical carbon dioxide physical foaming. TEM results show that the average diameters of CT and CM are 24.35 ± 3.15 nm and 30.45 ± 1.86 nm, respectively. The analysis of mechanical properties demonstrated that the tensile strength of pure EVA increased from 10.02 MPa to 13.01 MPa with the addition of only 0.2 wt% of CM. Furthermore, the addition of CM to EVA enhanced the melt strength of the polymer, leading to improvements in the physical foaming properties of the material. The results demonstrate that the pore size of the CM/EVA foam material is smaller than that of pure EVA foam. Additionally, the cell density of the CM/EVA foam material can reach 3.23 × 1011 cells/cm3