275 research outputs found

    An Assessment of Blood Vessel Remodeling of Nanofibrous Poly(Δ-Caprolactone) Vascular Grafts in a Rat Animal Model

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    The development of an ideal vascular prosthesis represents an important challenge in terms of the treatment of cardiovascular diseases with respect to which new materials are being considered that have produced promising results following testing in animal models. This study focuses on nanofibrous polycaprolactone-based grafts assessed by means of histological techniques 10 days and 6 months following suturing as a replacement for the rat aorta. A novel stereological approach for the assessment of cellular distribution within the graft thickness was developed. The cellularization of the thickness of the graft was found to be homogeneous after 10 days and to have changed after 6 months, at which time the majority of cells was discovered in the inner layer where the regeneration of the vessel wall was found to have occurred. Six months following implantation, the endothelialization of the graft lumen was complete, and no vasa vasorum were found to be present. Newly formed tissue resembling native elastic arteries with concentric layers composed of smooth muscle cells, collagen, and elastin was found in the implanted polycaprolactone-based grafts. Moreover, the inner layer of the graft was seen to have developed structural similarities to the regular aortic wall. The grafts appeared to be well tolerated, and no severe adverse reaction was recorded with the exception of one case of cartilaginous metaplasia close to the junctional suture

    An fMRI investigation of the neural correlates underlying the autonomous sensory meridian response (ASMR)

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    Introduction: The "autonomous sensory meridian response" (ASMR) is a neologism used to describe an internal sensation of deep relaxation and pleasant head tingling which is often stimulated by gentle sounds, light touch, and personal attention. Methods: An fMRI-based methodology was employed to examine the brain activation of subjects prescreened for ASMR-receptivity (n=10) as they watched ASMR videos and identified specific moments of relaxation and tingling. Results: Subjects who experienced ASMR showed significant activation in regions associated with both reward (NAcc) and emotional arousal (dACC and Insula/IFG). Brain activation during ASMR showed similarities to patterns previously observed in musical frisson as well as affiliative behaviors. Conclusion: This is the first study to measure the activation of various brain regions during ASMR and these results may help to reveal the mechanistic underpinnings of this sensation

    Proximal tubular cell–specific ablation of carnitine acetyltransferase causes tubular disease and secondary glomerulosclerosis

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    © 2019 by the American Diabetes Association. Proximal tubular epithelial cells are highly energy demanding. Their energy need is covered mostly from mitochondrial fatty acid oxidation. Whether derailments in fatty acid metabolism and mitochondrial dysfunction are forerunners of tubular damage has been suggested but is not entirely clear. Here we modeled mitochondrial overload by creating mice lacking the enzyme carnitine acetyltransferase (CrAT) in the proximal tubules, thus limiting a primary mechanism to export carbons under conditions of substrate excess. Mice developed tubular disease and, interestingly, secondary glomerulosclerosis. This was accompanied by increased levels of apoptosis regulator and fibrosis markers, increased oxidative stress, and abnormal profiles of acylcarnitines and organic acids suggesting profound impairments in all major forms of nutrient metabolism. When mice with CrAT deletion were fed a high-fat diet, kidney disease was more severe and developed faster. Primary proximal tubular cells isolated from the knockout mice displayed energy deficit and impaired respiration before the onset of pathology, suggesting mitochondrial respiratory abnormalities as a potential underlying mechanism. Our findings support the hypothesis that derailments of mitochondrial energy metabolism may be causative to chronic kidney disease. Our results also suggest that tubular injury may be a primary event followed by secondary glomerulosclerosis, raising the possibility that focusing on normalizing tubular cell mitochondrial function and energy balance could be an important preventative strategy

    Reader and author gender and genre in Goodreads

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    This is an accepted manuscript of an article published by SAGE Publishing in Journal of Librarianship & Information Science on 01/05/2017, available online: https://doi.org/10.1177/0961000617709061 The accepted version of the publication may differ from the final published version.There are known gender differences in book preferences in terms of both genre and author gender but their extent and causes are not well understood. It is unclear whether reader preferences for author genders occur within any or all genres and whether readers evaluate books differently based on author genders within specific genres. This article exploits a major source of informal book reviews, the Goodreads.com website, to assess the influence of reader and author genders on book evaluations within genres. It uses a quantitative analysis of 201,560 books and their reviews, focusing on the top 50 user-specified genres. The results show strong gender differences in the ratings given by reviewers to books within genres, such as female reviewers rating contemporary romance more highly, with males preferring short stories. For most common book genres, reviewers give higher ratings to books authored by their own gender, confirming that gender bias is not confined to the literary elite. The main exception is the comic book, for which male reviewers prefer female authors, despite their scarcity. A word frequency analysis suggested that authors wrote, and reviewers valued, gendered aspects of books within a genre. For example, relationships and romance were disproportionately mentioned by women in mystery and fantasy novels. These results show that, perhaps for the first time, it is possible to get large scale evidence about the reception of books by typical readers, if they post reviews online

    Reviewing, indicating, and counting books for modern research evaluation systems

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    In this chapter, we focus on the specialists who have helped to improve the conditions for book assessments in research evaluation exercises, with empirically based data and insights supporting their greater integration. Our review highlights the research carried out by four types of expert communities, referred to as the monitors, the subject classifiers, the indexers and the indicator constructionists. Many challenges lie ahead for scholars affiliated with these communities, particularly the latter three. By acknowledging their unique, yet interrelated roles, we show where the greatest potential is for both quantitative and qualitative indicator advancements in book-inclusive evaluation systems.Comment: Forthcoming in Glanzel, W., Moed, H.F., Schmoch U., Thelwall, M. (2018). Springer Handbook of Science and Technology Indicators. Springer Some corrections made in subsection 'Publisher prestige or quality

    The High-Resolution Coronal Imager, Flight 2.1

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    The third flight of the High-Resolution Coronal Imager (Hi-C 2.1) occurred on May 29, 2018; the Sounding Rocket was launched from White Sands Missile Range in New Mexico. The instrument has been modified from its original configuration (Hi-C 1) to observe the solar corona in a passband that peaks near 172 Å, and uses a new, custom-built low-noise camera. The instrument targeted Active Region 12712, and captured 78 images at a cadence of 4.4 s (18:56:22 – 19:01:57 UT; 5 min and 35 s observing time). The image spatial resolution varies due to quasi-periodic motion blur from the rocket; sharp images contain resolved features of at least 0.47 arcsec. There are coordinated observations from multiple ground- and space-based telescopes providing an unprecedented opportunity to observe the mass and energy coupling between the chromosphere and the corona. Details of the instrument and the data set are presented in this paper

    Unworking Milton: Steps to a Georgics of the Mind

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    Traditionally read as a poem about laboring subjects who gain power through abstract and abstracting forms of bodily discipline, John Milton’s Paradise Lost (1667, 1674) more compellingly foregrounds the erotics of the Garden as a space where humans and nonhumans intra-act materially and sexually. Following Christopher Hill, who long ago pointed to not one but two revolutions in the history of seventeenth-century English radicalism—the first, ‘the one which succeeded[,] . . . the protestant ethic’; and the second, ‘the revolution which never happened,’ which sought ‘communal property, a far wider democracy[,] and rejected the protestant ethic’—I show how Milton’s Paradise Lost gives substance to ‘the revolution which never happened’ by imagining a commons, indeed a communism, in which human beings are not at the center of things, but rather constitute one part of the greater ecology of mind within Milton’s poem. In the space created by this ecological reimagining, plants assume a new agency. I call this reimagining ‘ecology to come.

    The general fault in our fault lines

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    Pervading global narratives suggest that political polarization is increasing, yet the accuracy of such group meta-perceptions has been drawn into question. A recent US study suggests that these beliefs are inaccurate and drive polarized beliefs about out-groups. However, it also found that informing people of inaccuracies reduces those negative beliefs. In this work, we explore whether these results generalize to other countries. To achieve this, we replicate two of the original experiments with 10,207 participants across 26 countries. We focus on local group divisions, which we refer to as fault lines. We find broad generalizability for both inaccurate meta-perceptions and reduced negative motive attribution through a simple disclosure intervention. We conclude that inaccurate and negative group meta-perceptions are exhibited in myriad contexts and that informing individuals of their misperceptions can yield positive benefits for intergroup relations. Such generalizability highlights a robust phenomenon with implications for political discourse worldwide

    A Tale of Four “Carp”: Invasion Potential and Ecological Niche Modeling

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    . We assessed the geographic potential of four Eurasian cyprinid fishes (common carp, tench, grass carp, black carp) as invaders in North America via ecological niche modeling (ENM). These “carp” represent four stages of invasion of the continent (a long-established invader with a wide distribution, a long-established invader with a limited distribution, a spreading invader whose distribution is expanding, and a newly introduced potential invader that is not yet established), and as such illustrate the progressive reduction of distributional disequilibrium over the history of species' invasions.We used ENM to estimate the potential distributional area for each species in North America using models based on native range distribution data. Environmental data layers for native and introduced ranges were imported from state, national, and international climate and environmental databases. Models were evaluated using independent validation data on native and invaded areas. We calculated omission error for the independent validation data for each species: all native range tests were highly successful (all omission values <7%); invaded-range predictions were predictive for common and grass carp (omission values 8.8 and 19.8%, respectively). Model omission was high for introduced tench populations (54.7%), but the model correctly identified some areas where the species has been successful; distributional predictions for black carp show that large portions of eastern North America are at risk.ENMs predicted potential ranges of carp species accurately even in regions where the species have not been present until recently. ENM can forecast species' potential geographic ranges with reasonable precision and within the short screening time required by proposed U.S. invasive species legislation
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