1,735,020 research outputs found
Intestinal organoids as the model for pathogen-host interactions
No full textThe intestinal epithelium is an important barrier against pathogens in the lumen. Tight junctions between epithelial cells reduce the possibility of pathogens to pass through the mucosa and infect the host. A kind of specialized epithelial cell, known as microfold cells (M cells), can sample antigens from the lumen and transfer them to submucosal immune cells. This cell type initiates a specific immune response characterized by the secretion of sIgA. This thesis focuses more particularly on the interaction of the epithelium with porcine enteric viruses.
In the first part, we focused on establishing a new research model for enteric viruses based on intestinal organoids. In this study, intestinal organoids were differentiated from crypt stem cells of porcine small intestines. After 2-week culture in Matrigel, the organoids were collected and plated into suspension culture without Matrigel. In this way, apical-out organoids were generated. We then investigated the infection of the apical-out organoids by the Transmissible gastroenteritis virus (TGEV). The results show that apical-out organoids are a physiological model for virus-epithelium interaction research.
To better understand the mechanisms behind the differentiation of M cells, we investigated inflammation-related M cell differentiation. We found that both dextran sulphate sodium (DSS) treatment and Salmonella choleraesuis (S. choleraesuis) infection promotes transcription of M cells-related genes in mice. In the MyD88-/- mice, DSS failed to enhance the differentiation of M cells. We further demonstrate that receptor activator of NF-κB ligand (RANKL) can stimulate M cell differentiation in both wild type and MyD88-/- murine intestinal organoids. However, in MyD88-/- organoids, the RANKL-induced up-regulation of the M cell related gene is attenuated. These results suggest that MyD88 plays an essential role in regulating colitis-related and RANKL-induced M cell differentiation.
These studies indicate that intestinal organoids are a physiological model to investigate intestinal mucosal immunity. These results will provide data for further study on M cells’ function in enteric virus’ invasion
Deterministic Approximate Counting of Polynomial Threshold Functions via a Derandomized Regularity Lemma
Full text linkWe study the problem of deterministically approximating the number of satisfying assignments of a polynomial threshold function (PTF) over Boolean space. We present and analyze a scheme for transforming such algorithms for PTFs over Gaussian space into algorithms for the more challenging and more standard setting of Boolean space. Applying this transformation to existing algorithms for Gaussian space leads to new algorithms for Boolean space that improve on prior state-of-the-art results due to Meka and Zuckerman [Meka and Zuckerman, 2013] and Kane [Kane, 2012]. Our approach is based on a bias-preserving derandomization of Meka and Zuckerman’s regularity lemma for polynomials [Meka and Zuckerman, 2013] using the [Rocco A. Servedio and Li-Yang Tan, 2018] pseudorandom generator for PTFs
Amphinemura hainana Li & Yang
No full textAmphinemura hainana Li & Yang Amphinemura hainana Li & Yang, 2008c:65. Holotype ♂ (Entomological Museum of China Agricultural University), Nantianchi, Jianfengling, Ledong, Hainan, China Material examined. Vietnam: Tuyen Quang, tributary Gam River, 7 km NE Pac Ban, 24 May 1996, ROM 963093, D. Currie, D. Darling, 1♂, 1♀ (ROM). Remarks. This species is one of the most widely distributed Asian members of the genus with populations now reported from Inner Mongolia to Hainan (Li & Yang 2008c) and northern Vietnam. Males are easily recognized by virtue of the notched inner paraproct lobes and especially by the posterior margin of tergum 10 being divided into a pair of upturned, falcate processes. The female has a distinctive, triangular but deeply divided subgenital plate (Li & Yang 2008c).Published as part of Stark, Bill P. & Sivec, Ignac, 2010, Eight New Species Of Amphinemura (Plecoptera: Nemouridae) From Vietnam, pp. 41-51 in Illiesia 6 (5) on pages 46-47, DOI: 10.5281/zenodo.475960
Hybos liupanshanus Li & Yang 2009
No full text9. Hybos liupanshanus Li & Yang, 2009 Hybos liupanshanus Li & Yang, 2009: 354. Type locality: China: Ningxia, Liupanshan Mountain. Distribution. China (Ningxia). Remarks. This species was described by Li & Yang (2009) from 4 ♂ and 1 ♀ collected in Ningxia. It may be separated from H. pallidus Yang & Yang by the hind tibia without dorsal seta at middle and the long narrow apical portion of the hypandrium and a finger-like lateral process near the base (Li & Yang 2009, fig. 4).Published as part of Li, Zhu, Wang, Ning & Yang, Ding, 2014, New species of Hybos Meigen from Northwest China (Diptera: Empidoidea, Hybotinae), pp. 166-180 in Zootaxa 3786 (2) on page 172, DOI: 10.11646/zootaxa.3786.2.5, http://zenodo.org/record/22962
Mesonemoura tritaenia Li & Yang 2007
No full textMesonemoura tritaenia Li & Yang, 2007 Mesonemoura tritaenia Li & Yang, 2007. Aquatic Insects, 29: 178. Type locality: Henan (Neixiang, Baotianman) Distribution. China (Henan).Published as part of Li, Weihai & Yang, Ding, 2009, A new species of the genus Mesonemoura (Plecoptera: Nemouridae) and a key to the males of species known from China, pp. 62-68 in Zootaxa 2231 on page 64, DOI: 10.5281/zenodo.19029
Mesonemoura nielamuensis Li & Yang 2007
No full textMesonemoura nielamuensis Li & Yang, 2007. Mesonemoura nielamuensis Li & Yang, 2007. Aquatic Insects, 29: 175. Type locality: Tibet (Nielamu, Youyiqiao) Distribution. China (Tibet).Published as part of Li, Weihai & Yang, Ding, 2009, A new species of the genus Mesonemoura (Plecoptera: Nemouridae) and a key to the males of species known from China, pp. 62-68 in Zootaxa 2231 on page 64, DOI: 10.5281/zenodo.19029
Amphinemura cordiformis Li & Yang
No full textAmphinemura cordiformis Li & Yang Amphinemura cordiformis Li & Yang, 2006. Zootaxa, 1154: 41‐48. Material examined. 11 ♂, China: Guizhou Province, Leigong Mountain, Lianhuaping, 17‐18 September 2005, Wang Zhi‐ Jie. Distribution. Guizhou Province (Leigong Mountain, Dashahe), China.Published as part of Wang, Zhi-Jie, Du, Yu-Zhou, Sivec, Ignac & Li, Zi-Zhong, 2006, Records And Descriptions Of Some Nemouride Species (Order: Plecoptera) From Leigong Mountain, Guizhou Province, China, pp. 50-56 in Illiesia 2 (7) on page 50, DOI: 10.5281/zenodo.475460
Financial literacy and economic security in later life
No full textAs more adults approach retirement, the risk of economic insecurity post-retirement has garnered increasing attention. Financial literacy has been linked to greater economic security as it signals the knowledge and skills needed to manage financial resources. Yet, nearly half of American older adults possess inadequate financial literacy, which is linked to greater risk of making poor investment decisions, failing to maximize retirement benefits, and accumulating less wealth near retirement. Although targeted financial education has been advocated as a means to promote financial literacy, its effect is shown to be limited. Recent studies suggest that long-term exposure to financial experience (e.g. managing pension plans) is associated with higher financial literacy as it provides older adults with decision-making opportunities and the incentive to self-educate to improve financial literacy. I discuss the implication of these findings and additional policy options that may help older adults improve financial literacy and in turn economic securit
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