Orderly Spanning Trees with Applications

We introduce and study the {\em orderly spanning trees} of plane graphs. This algorithmic tool generalizes {\em canonical orderings}, which exist only for triconnected plane graphs. Although not every plane graph admits an orderly spanning tree, we provide an algorithm to compute an {\em orderly pair} for any connected planar graph $G$, consisting of a plane graph $H$ of $G$, and an orderly spanning tree of $H$. We also present several applications of orderly spanning trees: (1) a new constructive proof for Schnyder's Realizer Theorem, (2) the first area-optimal 2-visibility drawing of $G$, and (3) the best known encodings of $G$ with O(1)-time query support. All algorithms in this paper run in linear time.Comment: 25 pages, 7 figures, A preliminary version appeared in Proceedings of the 12th Annual ACM-SIAM Symposium on Discrete Algorithms (SODA 2001), Washington D.C., USA, January 7-9, 2001, pp. 506-51

Ginseng essence, a medicinal and edible herbal formulation, ameliorates carbon tetrachloride-induced oxidative stress and liver injury in rats

AbstractBackgroundGinseng essence (GE) is a formulation comprising four medicinal and edible herbs including ginseng (Panax ginseng), American ginseng (Panax quinquefolius), lotus seed (Nelumbo nucifera), and lily bulb (Lilium longiflorum). This study was aimed at investigating the hepatoprotective effect of GE against carbon tetrachloride (CCl4)-induced liver injury in rats.MethodsWe treated Wistar rats daily with low, medium, and high [0.625 g/kg body weight (bw), 1.25 g/kg bw, and 3.125 g/kg bw, respectively] doses of GE for 9 wk. After the 1st wk of treatment, rats were administered 20% CCl4 (1.5 mL/kg bw) two times a week to induce liver damage until the treatment ended.ResultsSerum biochemical analysis indicated that GE ameliorated the elevation of aspartate aminotransferase and alanine aminotransferase and albumin decline in CCl4-treated rats. Moreover, CCl4-induced accumulation of hepatic total cholesterol and triglyceride was inhibited. The hepatoprotective effects of GE involved enhancing the hepatic antioxidant defense system including glutathione, glutathione peroxidase, glutathione reductase, glutathione S-transferase, superoxide dismutase, and catalase. In addition, histological analysis using hematoxylin and eosin and Masson's trichrome staining showed that GE inhibited CCl4-induced hepatic inflammation and fibrosis. Furthermore, immunohistochemical staining of alpha-smooth muscle actin indicated that CCl4-triggered activation of hepatic stellate cells was reduced.ConclusionThese findings demonstrate that GE improves CCl4-induced liver inflammation and fibrosis by attenuating oxidative stress. Therefore, GE could be a promising hepatoprotective herbal formulation for future development of phytotherapy

Effects of human parvovirus B19 VP1 unique region protein on macrophage responses

<p>Abstract</p> <p>Background</p> <p>Activity of secreted phospholipase A (sPLA2) has been implicated in a wide range of cellular responses. However, little is known about the function of human parvovirus B19-VP1 unique region (VP1u) with sPLA2 activity on macrophage.</p> <p>Methods</p> <p>To investigate the roles of B19-VP1u in response to macrophage, phospholipase A2 activity, cell migration assay, phagocytosis activity, metalloproteinase assay, RT-PCR and immunoblotting were performed.</p> <p>Results</p> <p>In the present study, we report that migration, phagocytosis, IL-6, IL-1β mRNA, and MMP9 activity are significantly increased in RAW264.7 cells by B19-VP1u protein with sPLA2 activity, but not by B19-VP1uD175A protein that is mutated and lacks sPLA2 activity. Additionally, significant increases of phosphorylated ERK1/2 and JNK proteins were detected in macrophages that were treated with B19-VP1u protein, but not when they were treated with B19-VP1uD175A protein.</p> <p>Conclusion</p> <p>Taken together, our experimental results suggest that B19-VP1u with sPLA2 activity affects production of IL-6, IL-1β mRNA, and MMP9 activity, possibly through the involvement of ERK1/2 and JNK signaling pathways. These findings could provide clues in understanding the role of B19-VP1u and its sPLA2 enzymatic activity in B19 infection and B19-related diseases.</p

Anti-Cancer Effects of Protein Extracts from Calvatia lilacina, Pleurotus ostreatus and Volvariella volvacea

Calvatia lilacina (CL), Pleurotus ostreatus (PO) and Volvariella volvacea (VV) are widely distributed worldwide and commonly eaten as mushrooms. In this study, cell viabilities were evaluated for a human colorectal adenocarcinoma cell line (SW480 cells) and a human monocytic leukemia cell line (THP-1 cells). Apoptotic mechanisms induced by the protein extracts of PO and VV were evaluated for SW480 cells. The viabilities of THP-1 and SW480 cells decreased in a concentration-dependent manner after 24 h of treatment with the protein extracts of CL, PO or VV. Apoptosis analysis revealed that the percentage of SW480 cells in the SubG1 phase (a marker of apoptosis) was increased upon PO and VV protein-extract treatments, indicating that oligonucleosomal DNA fragmentation existed concomitantly with cellular death. The PO and VV protein extracts induced reactive oxygen species (ROS) production, glutathione (GSH) depletion and mitochondrial transmembrane potential (ΔΨm) loss in SW480 cells. Pretreatment with N-acetylcysteine, GSH or cyclosporine A partially prevented the apoptosis induced by PO protein extracts, but not that induced by VV extracts, in SW480 cells. The protein extracts of CL, PO and VV exhibited therapeutic efficacy against human colorectal adenocarcinoma cells and human monocytic leukemia cells. The PO protein extracts induced apoptosis in SW480 cells partially through ROS production, GSH depletion and mitochondrial dysfunction. Therefore, the protein extracts of these mushrooms could be considered an important source of new anti-cancer drugs

Observation of Temperature-Induced Crossover to an Orbital-Selective Mott Phase in Ax_{x}Fe2−y_{2-y}Se2_2 (A=K, Rb) Superconductors

In this work, we study the A$_{x}$Fe$_{2-y}$Se$_2$ (A=K, Rb) superconductors using angle-resolved photoemission spectroscopy. In the low temperature state, we observe an orbital-dependent renormalization for the bands near the Fermi level in which the dxy bands are heavily renormliazed compared to the dxz/dyz bands. Upon increasing temperature to above 150K, the system evolves into a state in which the dxy bands have diminished spectral weight while the dxz/dyz bands remain metallic. Combined with theoretical calculations, our observations can be consistently understood as a temperature induced crossover from a metallic state at low temperature to an orbital-selective Mott phase (OSMP) at high temperatures. Furthermore, the fact that the superconducting state of A$_{x}$Fe$_{2-y}$Se$_2$ is near the boundary of such an OSMP constraints the system to have sufficiently strong on-site Coulomb interactions and Hund's coupling, and hence highlight the non-trivial role of electron correlation in this family of iron superconductors

Non-leisure time physical activity is an independent predictor of longevity for a Taiwanese elderly population: an eight-year follow-up study

<p>Abstract</p> <p>Background</p> <p>The aim of this study is to determine the relationship between leisure time physical activity (LTPA) and non-leisure time physical activity (NLTPA) on mortality among the elderly in Taiwan.</p> <p>Methods</p> <p>This is a prospective observational cohort study. We analyzed the mortality data from a cohort of 876 non-institutionalized community-dwelling men and women aged 65 years or over, who were recruited by stratified clustering random sampling from Tainan city and participated in the 1996 Elderly Medication Survey. Information about activities and other variables were collected by structured interviews at baseline in the participants' home. The Cox proportional hazards model and crude death rate were applied to estimate mortality risk.</p> <p>Results</p> <p>Among the 876 participants, 312 died during the follow-up period (1996-2004). In the unadjusted Cox regression model, subjects aged over 75, having difficulty in carrying out activities of daily living (ADLs), a BMI less than 18.5, a history of diabetes mellitus or stroke, without LTPA or being inactive in NLTPA, were found to have a higher risk of eight-year mortality. With the adjustment for age, gender, education level, habitual smoking and drinking, living status, BMI and medical history, the mortality was found to be higher among the sedentary subjects, either defined by lack of LTPA or NLTPA, with the hazard ratio of 1.27 (95% confidence interval [CI] = 0.97-1.66) and 1.45 (95% CI = 1.07-1.97), respectively. Furthermore, when both LTPA and NLTPA were put into the model simultaneously, NLTPA (HR = 1.40; 95% CI = 1.03-1.91) but not LTPA (HR = 1.21, 95% CI = 0.92-1.59) significantly predicted mortality during eight-year follow-up. In addition, subjects who were actively engaged in NLTPA had a lower mortality risk especially in subjects without performing LTPA.</p> <p>Conclusions</p> <p>NLTPA is an independent predictor of longevity among older people in Taiwan. A physically active lifestyle, especially engaged in NLTPA, is associated with lower mortality risk in the elderly population. We thus suggest that encouraging older people to keep on engaging in customary NLTPA is good for their health.</p

Utilized mass spectrometry-based protein profiling system to identify potential biomarkers of hepatocellular carcinoma

AbstractHepatocellular carcinoma (HCC) is the most common malignant liver tumor. The purpose of this study is to characterize proteins secreted from the HepG2 cells, which may relate to cell differentiation and tumor metastasis. In the proteomic analysis, the secretome was identified by nano-high–performance liquid chromatography/electrospray ionization tandem mass spectrometry (nano-HPLC/ESIMS/MS) followed by peptide fragmentation pattern analysis. In this study, three proteins, p130Cas-associated protein (p130Cas/BCAR1), TAR DNA-binding protein 43 (TDP43/TARDBP) and translationally controlled tumor protein (TCTP/TPT1), were identified and confirmed by Western blotting, which showed significantly differential expression compared with the normal liver cells. Analyzing differential protein expressions in HepG2 cell by proteomic approaches suggests that p130Cas/BCAR1, TDP43/TARDBP and TCTP/TPT1 as key proteins and may serve as biomarkers for HCC

The relationships among Taiwanese youth’s polychronicity, multitasking behavior and perceived learning performance in online learning

BackgroundThe advancement of digital technology implies the importance of polychronic learning. Since polychronicity is not equivalent to multitasking behavior, they need to be considered separately. However, less research has been explored on how polychronicity is related to multitasking behavior in the educational field.ObjectiveTo explore the relationships among polychronicity, multitasking behavior and learning performance (including knowledge acquisition and learning satisfaction) in an online learning environment.MethodsThe relationship among variables was analyzed from 865 responses obtained from a questionnaire survey, and independent sample t tests and SEM analysis were used to examine the research hypotheses.ResultsCollege students showed a higher frequency of multitasking behavior, time tangibility and scheduling preference, and learning satisfaction in multitasking online learning environments than high school students. Additionally, college students were different from high school students on the paths of involvement with people to multitasking behavior (Δ χ2= 5.42, p = 0.02) and scheduling preference to learning satisfaction (Δχ2 = 9.54, p = 0.002).ConclusionThe relationship among polychronicity, multitasking behavior and perceived learning performance in an online learning environment varies by student educational stage