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Item Fairness analysis of throughput and delay in WLAN environments with channel diversities(2011) Wang, Chiapin; Lo, Hao-Kai; Fang, Shih-HauItem Molecular genetic and biochemical evidence for adaptive evolution of leaf abaxial epicuticular wax crystals in the genus Lithocarpus (Fagaceae)(2018-09-17) Yang, Chih-Kai; Huang, Bing-Hong; Ho, Shao-Wei; Huang, Meng-Yuan; Wang, Jenn-Che; Gao, Jian; Liao, Pei-ChunAbstract Background Leaf epicuticular wax is an important functional trait for physiological regulation and pathogen defense. This study tests how selective pressure may have forced the trait of leaf abaxial epicuticular wax crystals (LAEWC) and whether the presence/absence of LAEWC is associated with other ecophysiological traits. Scanning Electron Microscopy was conducted to check for LAEWC in different Lithocarpus species. Four wax biosynthesis related genes, including two wax backbone genes ECERIFERUM 1 (CER1) and CER3, one regulatory gene CER7 and one transport gene CER5, were cloned and sequenced. Ecophysiological measurements of secondary metabolites, photosynthesis, water usage efficiency, and nutrition indices were also determined. Evolutionary hypotheses of leaf wax character transition associated with the evolution of those ecophysiological traits as well as species evolution were tested by maximum likelihood. Results Eight of 14 studied Lithocarpus species have obvious LAEWC appearing with various types of trichomes. Measurements of ecophysiological traits show no direct correlations with the presence/absence of LAEWC. However, the content of phenolic acids is significantly associated with the gene evolution of the wax biosynthetic backbone gene CER1, which was detected to be positively selected when LAEWC was gained during the late-Miocene-to-Pliocene period. Conclusions Changes of landmass and vegetation type accelerated the diversification of tropical and subtropical forest trees and certain herbivores during the late Miocene. As phenolic acids were long thought to be associated with defense against herbivories, co-occurrence of LAEWC and phenolic acids may suggest that LAEWC might be an adaptive defensive mechanism in Lithocarpus.Item Phylogeography of the Alcippe morrisonia (Aves: Timaliidae): long population history beyond late Pleistocene glaciations(2009-06-27) Song, Gang; Qu, Yanhua; Yin, Zuohua; Li, Shouhsien; Liu, Naifa; Lei, FuminAbstract Background The role of Pleistocene glacial oscillations in current biodiversity and distribution patterns varies with latitude, physical topology and population life history and has long been a topic of discussion. However, there had been little phylogeographical research in south China, where the geophysical complexity is associated with great biodiversity. A bird endemic in Southeast Asia, the Grey-cheeked Fulvetta, Alcippe morrisonia, has been reported to show deep genetic divergences among its seven subspecies. In the present study, we investigated the phylogeography of A. morrisonia to explore its population structure and evolutionary history, in order to gain insight into the effect of geological events on the speciation and diversity of birds endemic in south China. Results Mitochondrial genes cytochrome b (Cytb) and cytochrome c oxidase I (COI) were represented by 1236 nucleotide sites from 151 individuals from 29 localities. Phylogenetic analysis showed seven monophyletic clades congruent with the geographically separated groups, which were identified as major sources of molecular variance (90.92%) by AMOVA. TCS analysis revealed four disconnected networks, and that no haplotype was shared among the geographical groups. The common ancestor of these populations was dated to 11.6 Mya and several divergence events were estimated along the population evolutionary history. Isolation by distance was inferred by NCPA to be responsible for the current intra-population genetic pattern and gene flow among geographical groups was interrupted. A late Pleistocene demographic expansion was detected in the eastern geographical groups, while the expansion time (0.2–0.4 Mya) was earlier than the Last Glacial Maximum. Conclusion It is proposed that the complicated topology preserves high genetic diversity and ancient lineages for geographical groups of A. morrisonia in China mainland and its two major islands, and restricts gene exchange during climate oscillations. Isolation by distance seems to be an important factor of genetic structure formation within geographical populations. Although glacial influence to population fluctuation was observed in late Pleistocene, it seems that populations in eastern China were more susceptible to climate change, and all geographical groups were growing stably through the Last Glacial Maximum. Coalescence analysis suggested that the ancestor of A. morrisonia might be traced back to the late Miocene, and the current phylogeographical structure of A. morrisonia is more likely to be attributable to a series geological events than to Pleistocene glacial cycles.Item Diversifying selection of the anthocyanin biosynthetic downstream gene UFGT accelerates floral diversity of island Scutellaria species(2016-09-17) Huang, Bing-Hong; Chen, Yi-Wen; Huang, Chia-Lung; Gao, Jian; Liao, Pei-ChunAbstract Background Adaptive divergence, which usually explains rapid diversification within island species, might involve the positive selection of genes. Anthocyanin biosynthetic pathway (ABP) genes are important for floral diversity, and are related to stress resistance and pollination, which could be responsible for species diversification. Previous studies have shown that upstream genes of ABP are subject to selective constraints and have a slow evolutionary rate, while the constraints on downstream genes are lower. Results In this study, we confirmed these earlier observations of heterogeneous evolutionary rate in upstream gene CHS and the downstream gene UFGT, both of which were expressed in Scutellaria sp. inflorescence buds. We found a higher evolutionary rate and positive selection for UFGT. The codons under positive selection corresponded to the diversified regions, and the presence or absence of an α-helix might produce conformation changes in the Rossmann-like fold structure. The significantly high evolutionary rates for UFGT genes in Taiwanese lineages suggested rapid accumulation of amino acid mutations in island species. The results showed positive selection in closely related species and explained the high diversification of floral patterns in these recently diverged species. In contrast, non-synonymous mutation rate decreases in long-term divergent species could reduce mutational load and prevent the accumulation of deleterious mutations. Conclusions Together with the positive selection of transcription factors for ABP genes described in a previous study, these results confirmed that positive selection takes place at a translational level and suggested that the high divergence of ABP genes is related to the floral diversity in island Scutellaria species.Item Examination of effects of GSK3β phosphorylation, β-catenin phosphorylation, and β-catenin degradation on kinetics of Wnt signaling pathway using computational method(2009-07-22) Sun, Ying-ChiehAbstract Background Recent experiments have explored effects of activities of kinases other than the well-studied GSK3β, in wnt pathway signaling, particularly at the level of β-catenin. It has also been found that the kinase PKA attenuates β-catenin degradation. However, the effects of these kinases on the level and degradation of β-catenin and the resulting downstream transcription activity remain to be clarified. Furthermore, the effect of GSK3β phosphorylation on the β-catenin level has not been examined computationally. In the present study, the effects of phosphorylation of GSK3β and of phosphorylations and degradation of β-catenin on the kinetics of the wnt signaling pathway were examined computationally. Methods The well-known computational Lee-Heinrich kinetic model of the wnt pathway was modified to include these effects. The rate laws of reactions in the modified model were solved numerically to examine these effects on β-catenin level. Results The computations showed that the β-catenin level is almost linearly proportional to the phosphorylation activity of GSK3β. The dependence of β-catenin level on the phosphorylation and degradation of free β-catenin and downstream TCF activity can be analyzed with an approximate, simple function of kinetic parameters for added reaction steps associated with effects examined, rationalizing the experimental results. Conclusion The phosphorylations of β-catenin by kinases other than GSK3β involve free unphorphorylated β-catenin rather than GSK3β-phosphorylated β-catenin*. In order to account for the observed enhancement of TCF activity, the β-catenin dephosphorylation step is essential, and the kinetic parameters of β-catenin phosphorylation and degradation need to meet a condition described in the main text. These findings should be useful for future experiments.Item Performance evaluation on an air-cooled heat exchanger for alumina nanofluid under laminar flow(2011) Teng, Tun-Ping; Hung, Yi-Hsuan; Teng, Tun-Chien; Chen, Jyun-HongItem Relationships between stress, coping and depressive symptoms among overseas university preparatory Chinese students: a cross-sectional study(2011) Chou, Pi-Chi; Chao, Yu-Mei; Yang, Hao-Jan; Yeh, Gwo-Liang; Lee, TonyItem Prison sentencing increases the risk of unemployment among illegal heroin users in Taiwan(2020-10-12) Lee, Charles T; Huang, Chiu-Mieh; Chang, Li-Chun; Wang, Shih-Wen; Hsu, Hsiao-Pei; Liao, Jung-Yu; Guo, Jong-LongAbstract Background Previous studies have rarely explored the effect of type of sentencing on employment status among illegal heroin users, therefore, we aims to examine the association of the sentencing types and employment outcomes among illegal heroin users in Taiwan. Methods Participants with illegal heroin use were identified through the national prison register system and deferred prosecution system: 2406 with deferred prosecutions, 4741 with observation and rehabilitation, 15 compulsory rehabilitation and 1958 sentenced to prison in calendar 2011. Logistic regression models were built to estimate the effect of sentencing type on unemployment status at 2 years after release. Stratification analysis was conducted to determine the effect of sentencing type based on the offender’s employment status before sentencing. Results Illegal heroin users receiving a prison sentence were more than twice as likely to be unemployed 2 years later than those receiving deferred prosecution. The unemployment rate was also higher for those with observation and rehabilitation and compulsory rehabilitation than deferred prosecution in the 2 years following sentencing. Males, older users, without a job before sentencing, divorced or widowed and higher prior drug use criminal records were also higher risk of unemployment. Subgroup analysis by prior employment status revealed that being sentenced to prison, observation and rehabilitation and compulsory rehabilitation affected the subsequent employment status only for those heroin users with a job before sentencing. The strength of associations showed dose-dependent relationship between different sentencing types (sentenced to prison> compulsory rehabilitation> observation and rehabilitation) and employment outcomes. Conclusions Illegal heroin users who receive a prison sentence have a much higher risk of unemployment than those who receive deferred prosecution after controlling potential confounders, especially those who had a job before sentencing. The implication is the stronger freedom of punishment, the higher risk of unemployment outcomes. Our study support that illegal heroin user is legally regarded as a patient before being regarded as a criminal, so giving priority to quit addition rather than imprisonment.Item Structural, biochemical, and physiological characterization of photosynthesis in leaf-derived cup-shaped galls on Litsea acuminata(2015-02-21) Huang, Meng-Yuan; Huang, Wen-Dar; Chou, Hsueh-Mei; Chen, Chang-Chang; Chen, Pei-Ju; Chang, Yung-Ta; Yang, Chi-MingAbstract Background The source and sink relationships between insect-induced galls and host plant leaves are interesting. In this research, we collected cup-like galls induced by Bruggmanniella sp. (Diptera: Cecidomyiidae) on host leaves of Litsea acuminata and assessed them to investigate source-sink relationships between galls and host leaves. We characterized several of their photosynthetic characteristics including chlorophyll fluorescence (Fv/Fm), stomatal conductance, and photosynthetic capacity, biochemical components such as total soluble sugar, starches, free amino acids, and soluble proteins. The structural analyses were performed under confocal, light, and scanning electron microscopies. Results Compared with host leaves, galls exhibited slightly lower chlorophyll fluorescence; however, stomatal conductance and photosynthetic capacity were not detected at all. Galls accumulated higher total soluble sugars and free amino acids but less soluble proteins than host leaves. No stomata was observed on exterior or interior gall surfaces under light or scanning electron microscopy, but their inner surfaces were covered with fungal hyphae. Confocal imagery showed a gradient of chloroplasts distribution between gall outer and inner surfaces. Conclusions Our results strongly suggest that leaf-derived cecidomyiid galls are a type of chlorophyll-deficient non-leaf green tissue and consists on a novel sink in L. acuminate.Item Comparison of the osmoregulatory capabilities among three amphibious sea snakes (Laticauda spp.) in Taiwan(2013) Cheng, Yuan-Cheng; Tu, Ming-Chung; Tsai, Jyuan-Ru; Lin, Hui-Chen; Lin, Li-Yih