Although coevolution is acknowledged to occur in nature, coevolutionary patterns in symbioses not involving species-to-species relationships are poorly understood. Mycorrhizal plants are thought to ...be too generalist to coevolve with their symbiotic fungi; yet some plants, including some orchids, exhibit strikingly narrow mycorrhizal specificity. Here, we assess the evolutionary history of mycorrhizal specificity in the lady's slipper orchid genus, Cypripedium. We sampled 90 populations of 15 taxa across three continents, using DNA methods to identify fungal symbionts and quantify mycorrhizal specificity. We assessed phylogenetic relationships among sampled Cypripedium taxa, onto which we mapped mycorrhizal specificity. Cypripedium taxa associated almost exclusively with fungi within family Tulasnellaceae. Ancestral specificity appears to have been narrow, followed by a broadening after the divergence of C. debile. Specificity then narrowed, resulting in strikingly narrow specificity in most of the taxa in this study, with no taxon rewidening to the same extant as basal members of the genus. Sympatric taxa generally associated with different sets of fungi, and most clades of Cypripedium-mycorrhizal fungi were found throughout much of the northern hemisphere, suggesting that these evolutionary patterns in specificity are not the result of biogeographic lack of opportunity to associate with potential partners. Mycorrhizal specificity in genus Cypripedium appears to be an evolvable trait, and associations with particular fungi are phylogenetically conserved.
Abstract Background and aim The model for end-stage liver disease (MELD) is used to predict the outcome of patients with cirrhosis. Incorporation of serum sodium (Na) into MELD may further increase ...its prognostic ability. Two Na-containing MELD models, MELD-Na and MELDNa, were proposed to enhance the prognostic ability. This study compared the predictive accuracy of these models for acute decompensated hepatitis. Methods We investigated the outcome of 182 patients with acute decompensated hepatitis. Results Twenty (11%) patients died at 3 months. The MELD-Na and MELDNa both had significantly higher area under the receiver operating characteristic curve (AUC) in comparison to MELD (MELD-Na: 0.908, MELDNa: 0.895, MELD: 0.823, p = 0.004 and 0.001, respectively). Among 96 patients without specific antiviral treatment, the MELD-Na and MELDNa consistently had significantly higher AUC than the MELD (MELD-Na: 0.901, MELDNa: 0.882, MELD: 0.810, p = 0.008 and 0.004, respectively). Three independent indicators, pre-existing cirrhosis (odds ratio OR: 5.67, 95% confidence interval CI: 1.72–18.7), serum albumin <3.7 g/dL (OR: 5.68, 95% CI: 1.18–27.03) and serum sodium (Na) < 138 mequiv./L (OR: 10.0, 95% CI: 2.08–47.62), were associated with 3-month mortality. Conclusion MELD-Na and MELDNa provide better prognostic accuracy than the MELD for patients with acute decompensated hepatitis. The adequacy of liver reserve determines the outcome of these patients.
碩士
國立臺北教育大學
課程與教學研究所
98
The purpose of this research is to study M. Foucault’s viewpoint of the aesthetics of existence, and try to find the inspirations for curriculum aesthetics. After exploring M. ...Foucault’s viewpoint of the aesthetics of existence, researcher sum up three core concepts of the self-care, ethical subjects and technologies of the self skills, and practical approaches including limit experience , out of thinking and true game. Furthermore, researcher oriented dialogue on critical aesthetics through the core infrastructure, aesthetic ideas, practical approaches and in the form of freedom. And then, pointing out that the ultimate aesthetics of existence lies in care of the self. In addition, they exceed the implicit concept of ethics as well as practical outlook for the current criticism of aesthetics-oriented courses to provide another round of new thinking.
Finally, as a point of view of the revelation of the aesthetics curriculum, researcher believe that the program should be to arouse the s
碩士
國立中山大學
企業管理研究所
84
Because the game rule has changed in the industries, the
resource -based model becomes more popular when enterprises
diversify.Due to this reason, this research creates a ...practical
model of diver -sification, which combines the concept of core
competence and strategic intent. Practicing this model,
enterprises can get growth by means of using resources well and
diversifying in such a competitive environment. The research
obtains some conclusions listed below： 1 .In the industries,it
should be recognized that the game rule has become internal
resource-oriented which was external market-oriented before. 2
.Enterprises should be viewed as a portfolio of core compe
-tences instead of products. 3 .Diversification should be
viewed as a mean instead of a final object. 4 .The selection of
diversifying businesses should be judged by the criteria of
skill transfer or resource sharing in the present or future. 5
.Due to the fact that all long-lasting competitive advantages
are based on strong human
碩士
中國文化大學
國際貿易學系
104
Importance: Fan relationship management is one of important strategic issues for doing business. Few managing fan pages can survive without building and maintaining solid online ...and offline interpersonal interaction with their followers. Rather, relation-ship benefit and relationship quality have received relatively little attention in the Coser marketing literature; the goal of this study tries to fill this gap in the literature.
Purpose: This study investigates Coser fan page users and its members to develop a comprehensive research model for relationship establishing. In the online and offline context, the proposed model discusses two phases: firstly, the relationship benefit fac-tors whether effects on respondents’ perceptions of relationship quality building. Sec-ondly, dimensions of relationship quality whether enhance respondents’ perceptions of relational benefits which can develop loyalty intention and promote respondents’ word of mouth engagement towards Coser and its fan manage
A fundamental question that applies to all organisms is how barrier epithelia efficiently manage continuous contact with microorganisms. Here, we show that in
Drosophila an extracellular ...immune-regulated catalase (IRC) mediates a key host defense system that is needed during host-microbe interaction in the gastrointestinal tract. Strikingly, adult flies with severely reduced IRC expression show high mortality rates even after simple ingestion of microbe-contaminated foods. However, despite the central role that the NF-κB pathway plays in eliciting antimicrobial responses, NF-κB pathway mutant flies are totally resistant to such infections. These results imply that homeostasis of redox balance by IRC is one of the most critical factors affecting host survival during continuous host-microbe interaction in the gastrointestinal tract.
Aim
To evaluate the effect of 2,3,5,4′‐tetrahydroxystilbene‐2‐O‐β‐D‐glucoside (THSG) on cell proliferation and examine the mechanisms of THSG‐enhanced proliferative potential in human dental pulp ...stem cells (hDPSC).
Methodology
After treatment with THSG, hDPSC were collected. Cell viability was determined by MTS assay, while messenger RNA (mRNA) expressions of proliferation and stem cell markers were analyzed using real‐time PCR. Flow cytometry was also conducted to analysis protein expression of stem cell markers. A colony‐forming unit assay of hDPSC was carried out. Cellular telomerase activity was also identified using real‐time PCR. In addition, proliferation‐related proteins involved in the effects of THSG on hDPSC were analyzed by Western blotting. Data were analyzed using one‐way analysis of variance and two‐tailed Student's t‐test.
Results
Cell viability, colony‐forming rates and telomerase activities of hDPSCs were enhanced after THSG treatment. mRNA expressions of proliferation markers (including expressions of NAD+‐dependent histone deacetylase sirtuin 1 (SIRT1), proliferating cell nuclear antigen (PCNA), cyclin D1 and ribonucleotide reductase subunit M2 (RRM2)) increased significantly after THSG treatment (P < 0.05). Treatment with THSG for 3 h significantly augmented SIRT1 protein expression (P < 0.05). Furthermore, activities of proliferation‐related proteins (including AMP‐activated protein kinase (AMPK) and extracellular signal‐regulated kinase (ERK) had also significantly increased at 3 h (P < 0.05). After THSG treatment, increased gene and protein expressions of pluripotent‐like stem cell markers (including NANOG, OCT4, and SOX2) were observed.
Conclusions
2,3,5,4′‐Tetrahydroxystilbene‐2‐O‐β‐glucoside treatment enhanced the renewal ability and proliferative potential of hDPSCs via the AMPK/ERK/SIRT1 axis, which may provide a novel autogenic cell‐based therapeutic strategy in regenerative dentistry.
MicroRNAs (miRNAs) play important roles in tumorigenesis by regulating oncogenes and tumor-suppressor genes. In this study, miR-187 and miR-200a were found to be expressed at higher levels in ovarian ...cancers than in benign tumors. In patients with ovarian cancer, however, higher levels of miR-187 and miR-200a expression were paradoxically associated with better OS and recurrence-free survival. Further, multivariate analysis showed that miR-187 served as an independent prognostic factor for patients with ovarian cancer (n=176). Computational prediction and microarray results indicated that miR-187 directly targeted Disabled homolog-2 (Dab2), and luciferase reporter assays confirmed that the target site of miR-187 was located at the 3'-UTR of the Dab2 gene. Generally considered as a tumor-suppressor gene, Dab2 may actually promote tumor progression in advanced cancers through epithelial-to-mesenchymal transition (EMT). Ectopic expression of miR-187 in cancer cells promoted cell proliferation, but continued overexpression of miR-187 suppressed Dab2 and inhibited migration. Suppression of miR-187 upregulated Dab2, which, by inhibiting E-cadherin levels while stimulating vimentin and phospho-FAK levels, promoted EMT. Reduced ovarian cancer Dab2 histoscores correlated with high miR-187 levels and improved outcomes of patients. Collectively, these results demonstrate distinct dual roles of Dab2 in cell proliferation and tumor progression. In the initial steps of tumorigenesis, upregulated miR-187 suppresses Dab2, promoting cell proliferation. During the later stages, however, continued increased levels of miR-187 inhibits the Dab2-dependent EMT that is associated with tumor invasiveness, which is presumed to be the reason why cancers with high miR-187 levels were associated with better survivals.
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