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Polyploidy results from whole-genome duplication and is a unique form of heritable variation with pronounced evolutionary implications. Different ploidy levels, or cytotypes, can exist within a single species, and such systems provide an opportunity to assess how ploidy variation alters phenotypic novelty, adaptability, and fitness, which can, in turn, drive the development of unique ecological niches that promote the coexistence of multiple cytotypes. Switchgrass, Panicum virgatum, is a widespread, perennial C4 grass in North America with multiple naturally occurring cytotypes, primarily tetraploids (4×) and octoploids (8×). Using a combination of genomic, quantitative genetic, landscape, and niche modeling approaches, we detect divergent levels of genetic admixture, evidence of niche differentiation, and differential environmental sensitivity between switchgrass cytotypes. Taken together, these findings support a generalist (8×)–specialist (4×) trade-off. Our results indicate that the 8× represent a unique combination of genetic variation that has allowed the expansion of switchgrass’ ecological niche and thus putatively represents a valuable breeding resource.

Background Primary intestinal non-Hodgkin lymphoma (NHL) is a heterogeneous disease with regard to anatomic and histologic distribution. Thus, analyses focusing on primary intestinal NHL with large number of patients are warranted. Methods We retrospectively analyzed 581 patients from 16 hospitals in Korea for primary intestinal NHL in this retrospective analysis. We compared clinical features and treatment outcomes according to the anatomic site of involvement and histologic subtypes. Results B-cell lymphoma (n = 504, 86.7%) was more frequent than T-cell lymphoma (n = 77, 13.3%). Diffuse large B-cell lymphoma (DLBCL) was the most common subtype (n = 386, 66.4%), and extranodal marginal zone B-cell lymphoma of mucosa-associated lymphoid tissue (MALT) was the second most common subtype (n = 61, 10.5%). B-cell lymphoma mainly presented as localized disease (Lugano stage I/II) while T-cell lymphomas involved multiple intestinal sites. Thus, T-cell lymphoma had more unfavourable characteristics such as advanced stage at diagnosis, and the 5-year overall survival (OS) rate was significantly lower than B-cell lymphoma (28% versus 71%, P < 0.001). B symptoms were relatively uncommon (20.7%), and bone marrow invasion was a rare event (7.4%). The ileocecal region was the most commonly involved site (39.8%), followed by the small (27.9%) and large intestines (21.5%). Patients underwent surgery showed better OS than patients did not (5-year OS rate 77% versus 57%, P < 0.001). However, this beneficial effect of surgery was only statistically significant in patients with B-cell lymphomas (P < 0.001) not in T-cell lymphomas (P = 0.460). The comparison of survival based on the anatomic site of involvement showed that ileocecal regions had a better 5-year overall survival rate (72%) than other sites in consistent with that ileocecal region had higher proportion of patients with DLBCL who underwent surgery. Age > 60 years, performance status ≥ 2, elevated serum lactate dehydrogenase, Lugano stage IV, presence of B symptoms, and T-cell phenotype were independent prognostic factors for survival. Conclusions The survival of patients with ileocecal region involvement was better than that of patients with involvement at other sites, which might be related to histologic distribution, the proportion of tumor stage, and need for surgical resection.

Background The Brassicaceae family is an exemplary model for studying plant polyploidy. The Brassicaceae knowledge-base includes the well-annotated Arabidopsis thaliana reference sequence; well-established evidence for three rounds of whole genome duplication (WGD); and the conservation of genomic structure, with 24 conserved genomic blocks (GBs). The recently released Brassica rapa draft genome provides an ideal opportunity to update our knowledge of the conserved genomic structures in Brassica , and to study evolutionary innovations of the mesohexaploid plant, B. rapa . Results Three chronological B. rapa genomes (recent, young, and old) were reconstructed with sequence divergences, revealing a trace of recursive WGD events. A total of 636 fast evolving genes were unevenly distributed throughout the recent and young genomes. The representative Gene Ontology (GO) terms for these genes were ‘stress response’ and ‘development’ both through a change in protein modification or signaling, rather than by enhancing signal recognition. In retention patterns analysis, 98% of B. rapa genes were retained as collinear gene pairs; 77% of those were singly-retained in recent or young genomes resulting from death of the ancestral copies, while others were multi-retained as long retention genes. GO enrichments indicated that single retention genes mainly function in the interpretation of genetic information, whereas, multi-retention genes were biased toward signal response, especially regarding development and defense. In the recent genome, 13,302, 5,790, and 20 gene pairs were multi-retained following Brassica whole genome triplication (WGT) events with 2, 3, and 4 homoeologous copies, respectively. Enriched GO-slim terms from B. rapa homomoelogues imply that a major effect of the B. rapa WGT may have been to acquire environmental adaptability or to change the course of development. These homoeologues seem to more frequently undergo subfunctionalization with spatial expression patterns compared with other possible events including nonfunctionalization and neofunctionalization. Conclusion We refined Brassicaceae GB information using the latest genomic resources, and distinguished three chronologically ordered B. rapa genomes. B. rapa genes were categorized into fast evolving, single- and multi-retention genes, and long retention genes by their substitution rates and retention patterns. Representative functions of the categorized genes were elucidated, providing better understanding of B. rapa evolution and the Brassica genus.

Background The prognostic role of serum estrogen level in breast cancer patients is unclear. We investigated the prognostic importance of preoperative serum estradiol (E2) level in postmenopausal women according to their estrogen receptor (ER) status. Methods The medical records of 313 postmenopausal breast cancer patients who underwent surgery between 2006 and 2008 at a single institution were retrospectively evaluated. Patients who received neoadjuvant chemotherapy, synchronous bilateral breast cancer, or those with metastasis at diagnosis were excluded. Serum E2 and follicular stimulating hormone (FSH) levels were measured by radioimmunoassay and immunoradiometric assay, respectively, within 3 months prior to surgery. After a median follow-up of 52.0 months (11–77 months), 21 women were found to have metastatic disease. Results The overall, median E2 level was 13.0 pg/ml, and was slightly higher in ER-positive than ER-negative (p=0.69). The mean serum E2 level was significantly higher in patients with metastasis (17.41±8.34 pg/ml) than in those without metastasis (13.54±7.58 pg/ml) (p=0.02). Kaplan-Meier analysis using a cut-off of 13 pg/ml showed that, ER negative (p=0.02) but not ER positive (p>0.05) patients with higher E2 level showed significantly poorer metastasis-free survival. Multivariate analysis showed that, the high E2 level of ER negative tumors was an independent negative prognostic factor for metastasis- free survival (HR, 3.32; 95% CI, 1.05 to 10.51; p=0.04). Conclusions Higher preoperative serum E2 level had a negative prognostic effect in postmenopausal women with breast cancer, especially in the ER-negative subgroup.

It has long been considered that intron-containing (spliced) mRNAs are translationally more active than intronless mRNAs (identical mRNA not produced by splicing). The splicing-dependent translational enhancement is mediated, in part, by the exon junction complex (EJC). Nonetheless, the molecular mechanism by which each EJC component contributes to the translational enhancement remains unclear. Here, we demonstrate the previously unappreciated role of eukaryotic translation initiation factor 4AIII (eIF4AIII), a component of EJC, in the translation of mRNAs bound by the nuclear cap-binding complex (CBC), a heterodimer of cap-binding protein 80 (CBP80) and CBP20. eIF4AIII is recruited to the 5'-end of mRNAs bound by the CBC by direct interaction with the CBC-dependent translation initiation factor (CTIF); this recruitment of eIF4AIII is independent of the presence of introns (deposited EJCs after splicing). Polysome fractionation, tethering experiments, and in vitro reconstitution experiments using recombinant proteins show that eIF4AIII promotes efficient unwinding of secondary structures in 5'UTR, and consequently enhances CBC-dependent translation in vivo and in vitro. Therefore, our data provide evidence that eIF4AIII is a specific translation initiation factor for CBC-dependent translation.

Human bone marrow-derived mesenchymal stem cells (hBM-MSCs) are widely used in a number of cell therapies and have osteogenic differentiation capacity. Exposure to electromagnetic fields (EMFs) increases the osteogenic differentiation of hBM-MSCs. Nanomagnetic particles (MPs) also promote the differentiation potential of stem cells. In the present study, we investigated the effects of EMFs and MPs on the osteogenic differentiation of hBM-MSCs. hBM-MSCs were treated with 50 μg/ml of Fe3O4 MPs or exposed to a frequency of 45 Hz and an intensity of 1 mT EMF twice every 8 h per day for 7 days. MP incorporation, EMF exposure and MP incorporation with exposure to EMFs did not induce cytotoxic effects. A strong expression of osteogenic markers (osteocalcin, osteopontin and osteonectin) and von Kossa staining intensity was observed in the cells treated with MPs, the cells exposed to EMFs and in the cells treated with MPs and exposed to EMFs compared with the control group, as shown by immunohistochemical staining. Quantitative RT-PCR revealed that the mRNA expression levels of osteoblast markers [osteocalcin, osteopontin, osteonectin, collagen I, collagen III, bone morphogenetic protein 2 (BMP-2), bone sialoprotein (BSP) and runt-related transcription factor 2 (Runx-2)] were markedly increased in the cells treated with MPs and exposed to EMFs. Furthermore, the mRNA expression of calcium channels (CACNA1C, CACNA1E, CACNA1G and CACNA1I) was activated during osteogenic differentiation. The expression levels of osteogenesis-related proteins (BSP, BMP-2, osteopontin and osteonectin) and phosphorylated extracellular signal-regulated kinase (p-ERK) were increased in the cells treated with MPs, those exposed to EMFs and in the cells treated with MPs and exposed to EMFs compared with the control group, as shown by western blot analysis. Fluorescence-activated cell sorting (FACS) analysis was performed for the hBM-MSC markers, CD73, CD90 and CD105. The expression levels of hBM-MSC surface antigens were decreased in the cells treated with MPs, those exposed to EMFs and in the cells treated with MPs and exposed to EMFs compared with the control group. The cell numbers were determined to be approximately 3.4×105 cells in the control group, 3.7×105 cells in the MP-treated group, 3.1×105 cells in the group exposed to EMFs and 3.9×105 cells in the group treated with MPs and exposed to EMFs. The cell mitochondrial activity among the 4 experimental groups was similar. The hBM-MSCs treated with MPs and exposed to EMFs showed an increase in alkaline phosphatase (ALP) activity. Taken together, these results suggest that the treatment of hBM-MSCs with MPs or exposure to EMFs increases osteogenic differentiation, and that treatment with MPs in conjunction with EMF exposure is more effective in increasing osteogenic differentiation.

Intracellular cAMP and Ca^2＋ are involved in the regulation of steroidogenic activity in Leydig cells, which coordinate responses to luteinizing hormone （LH） and human ehorionic gonadotropin （hCG）. However, the identification of Ca^2＋ entry implicated in Leydig cell steroidogenesis is not well defined. The objective of this study was to identify the type of Ca^2＋ channel that affects Leydig cell steroidogenesis. In vitro steroidogenesis in the freshly dissociated Leydig cells of mice was induced by hCG incubation. The effects of mibefradil （a putative T-type Ca^2＋ channel blocker） on steroidogenesis were assessed using reverse transcription （RT）-polymerase chain reaction analysis for the steroidogenic acute regulatory protein （STAR） mRNA expression and testosterone production using radioimmunoassay. In the presence of 1.0 mmol L-1 extracellular Ca^2＋, hCG at 1 to 100 IU noticeably elevated both StAR mRNA level and testosterone secretion （P 〈 0.05）, and the stimulatory effects of hCG were markedly diminished by mibefradil in a dose-dependent manner （P 〈 0.05）. Moreover; the hCG-induced increase in testosterone production was completely removed when external Ca^2＋ was omitted, implying that Ca entry is needed for hCG-induced steroidogenesis. Furthermore, a patch-clamp study revealed the presence of mibefradil-sensitive Ca^24- currents seen at a concentration range that nearly paralleled those inhibiting steroidogenesis. Collectively, Our data provide evidence that hCG-stimulated steroidogenesis is mediated at least in part by Ca^2＋ entry carried out by the T-type Ca^2＋ channel in the Leydig cells of mice.

Background and Aims Climate warming and increased atmospheric nitrogen (N) deposition both have the potential to increase plant productivity over the next century, yet they can also increase decomposition and respiration. Our aim was to examine the extent to which warming and N addition can, on balance, alter net ecosystem CO₂ exchange (NEE) in a grass-dominated system. Methods We measured NEE responses to warming and N addition over two growing seasons in a temperate old field using steady-state flow-through chambers, which allowed for the integrated measurement of respiration and photoassimilation effects on net CO₂ flux over diel periods. We also assessed the relationship between NEE and plant biomass responses to the warming and N treatments. Results In both years, our study system was a net source of carbon (C) during the snow-free season. N addition did not significantly affect diel NEE or dark respiration in either year, despite a doubling in aboveground plant biomass in response to N addition in the second year, and a corresponding increase in peak daily net CO₂ photoassimilation in N addition plots. The warming treatment also had no significant effect on NEE, although the flow-through chambers required warming to be temporarily halted during NEE measurements. Conclusions Overall, our results both highlight the potential divergence of plant and soil responses to N addition and demonstrate the capacity for a grassdominated system to function as a net source of C in consecutive years.

We aim to provide an explanation for how the human brain might connect words for sentence formation. A novel approach to modeling syntactic representation is introduced, potentially showing the existence of universal syntactic structures for all natural languages. As the discovery of DNA's double helix structure shed light on the inner workings of genetics, we wish to introduce a basic understanding of how language might work in the human brain. It could be the brain's way of encoding and decoding knowledge. It also brings some insight into theories in linguistics, psychology, and cognitive science. After looking into the logic behind universal syntactic structures and the methodology of the modeling technique, we attempt to analyze corpora that showcase universality in the language process of different natural languages such as English and Korean. Lastly, we discuss the critical period hypothesis, universal grammar, and a few other assertions on language for the purpose of advancing our understanding of the human brain.

Various levels of governments in Canada have introduced different types of tax instruments in order to encourage the development of renewable energy. This paper will look at the challenges that render those tax instruments inefficient and/or ineffective. For the ease of discussion, I will divide the said challenges by a hypothetical timeline of “before” and “during” the implementation of renewable energy. “Before” the implementation, some of the current tax incentives are criticized to be ineffective because there are better policy substitutes. It is also found that the inherent characteristics of renewable energy sources themselves render policy instruments inefficient. “During” the implementation, the currently existing “unlevel playing field” with the conventional oil and gas industry is found to be the strongest factor that causes tax incentives on renewable energy ineffective; the introduction of a carbon tax is recommended here. Lastly, even the most comprehensive tax measures are found unable to completely address the “exogenous” factors.