102,877 research outputs found

    The effects of Bilirubin and Bilirubin-di-taurate on ischemia reperfusion injruy in a rat model of kidney transplantation

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    Background: Heme oxygenase-1 (HO-1) is the rate-limiting enzyme in the conversion of heme into biliverdin, carbon monoxide (CO) and free iron. Biliverdin is then subsequently reduced to bilirubin by the enzyme bilverdin reductase. In the past decades a lot of effort was conducted to investigate the beneficial effects of HO-1 and its end products biliverdin/bilirubin and CO. Due to intensive research, solid organ transplantation can nowadays be seen as clinical routine. However ischemia reperfusion injury (IR), acute rejection episodes and the occurrence of chronic rejection remain main problems. The severity of IRI can be seen as a prognostic factor for early graft function, immunogenecity of grafts as well as for long term graft survival. The goal of our experiments was to investigate the potential beneficial effects of bilirubin and biliverdin on ischemia reperfusion in a kidney transplantation model of the rat. Methods: Two different sets of experiments were performed: First, kidneys of Lewis rats were exposed to 60 minutes of warm ischemia by clamping the renal artery followed by a 24h reperfusion period. This model was used to find the optimal dosing regimen of bilirubin/biliverdin before the more clinical relevant model of kidney transplantation in the rat was performed. We found that three doses of 10mg/Kg bilirubin were the most effective dose regimen to protect kidneys from ischemia reperfusion injury. In the second set of experiments, kidney transplantation was performed in Lewis rats. Kidneys were harvested and stored in 4C cold UW-solution for 18h. Subsequently the kidneys were transplanted isotopically into the recipient rat. Time of warm ischemia was kept in all experiments constantly at 60 minutes. After 24h of reperfusion tissue samples and serum were harvested for further analyses. Results: Systemic treatment of bilirubin led to a significant amelioration of organ function after ischemia reperfusion injury as assessed by measuring serum creatinine levels and BUN levels after 24h of reperfusion. In addition treated animals showed increased eGFR and a better cell integrity as histomorphological analyses could demonstrate. Conclusion: Systemic treatment with bilirubin and bilverdin has beneficial effects on graft function after ischemia rerperfusion injury

    Experimental Determination and Validation of sUAS Moments of Inertia

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    The rise in use of small unmanned aerial systems (sUAS) in industry and research has resulted in a need to develop modeling and testing procedures which are feasible and cost effective for small-scale airframes. Computer models of these vehicles are based on a description of the underlying physical and aerodynamic characteristics of these vehicles which are often only roughly approximated in the design stage. One difficult to accurately obtain, yet highly important, physical characteristic of an aircraft is its inertia tensor. The aircraft’s inertia tensor is directly related to the dynamic motion about the pitch, roll, and yaw axes. Understanding this dynamic motion is the first step in control system design and validation. Utilizing previous work in experimental moment of inertia (MOI) testing and small-scale flight testing, this project developed a bifilar torsional pendulum capable of accurately and affordably measuring the inertia tensor of sUAS. In order to validate the bifilar pendulum measurements, flight tests were developed to experimentally obtain the MOI of the sUAS for comparison. Due to changes in Ohio State University policy after the outbreak of COVID-19, the planned flight tests could not be completed at this time. Future work should focus on the validation of the bifilar pendulum measurements along with determination and validation of MOI for non-primary axes.No embargoAcademic Major: Aeronautical and Astronautical Engineerin

    Was Television Responsible for a New Generation of Smokers?

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    Consumers’ response to mass media can be difficult to assess because individuals choose for themselves the amount of media they consume, and that choice may be correlated with their other consumption decisions. To avoid this selection problem, this article examines the introduction of television to the US, during which some cities gained access to television years before others. This natural experiment makes it possible to estimate the causal impact of television on the decision to start smoking, a consumer behavior with important public health implications. Difference-in-differences analyses of television’s introduction indicate that (1) television did cause people to start smoking, (2) 16- to 21-year-olds were particularly affected by television, and (3) much of the response to television occurred within a couple of years of its introduction. Our preferred estimates suggest that television increased the share of smokers in the population by 5–15 percentage points, generating roughly 11 million additional smokers between 1946 and 1970. More broadly, these results offer causal evidence that (1) mass media can have a large influence on consumers, potentially affecting their health, (2) media exerts an especially strong influence on teens, and (3) mass media can influence consumers more than typical changes in prices

    Bilingualism and the single route/dual route debate

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    The debate between single and dual route accounts of cognitive processes has been generated predominantly by the application of connectionist modeling techniques to two areas of psycholinguistics. This paper draws an analogy between this debate and bilingual language processing. A prominent question within bilingual word recognition is whether the bilingual has functionally separate lexicons for each language, or a single system able to recognize the words in both languages. Empirical evidence has been taken to support a model which includes two separate lexicons working in parallel (Smith, 1991; Gerard and Scarborough, 1989). However, a range of interference effects has been found between the bilingual’s two sets of lexical knowledge (Thomas, 1997a). Connectionist models have been put forward which suggest that a single representational resource may deal with these data, so long as words are coded according to language membership (Thomas, 1997a, 1997b, Dijkstra and van Heuven, 1998). This paper discusses the criteria which might be used to differentiate single route and dual route models. An empirical study is introduced to address one of these criteria, parallel access, with regard to bilingual word recognition. The study fails to find support for the dual route model

    A revision of Pediacus Shuckard (Coleoptera: Cucujidae) for America north of Mexico : with notes on other species

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    The genus Pediacus Shuckard is revised for America north of Mexico. Seven species are recorded: P. andrewsi Thomas, n. sp.; P. fuscus Erichson; P. gracilis Thomas, n. sp.; P. hesperoglaber Thomas, n. sp.; P. ommatodon Thomas, n. sp.; P. stephani Thomas, n. sp.; and P. subglaber LeConte, new status. The species are described and illustrated, and a key is presented for their identification. The described European and Neotropical species are reviewed and illustrated

    The Brontini of the world : a generic review of the tribe (Coleoptera: Silvanidae: Brontinae)

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    The genera of the tribe Brontini (Silvanidae: Brontinae) are reviewed. The tribe is considered here to be composed of 12 genera, Uleiota Latreille, Brontopriscus Sharp, and Dendrophagus Schönherr, plus nine new genera: Australodendrophagus, Australohyliota, Brontoliota, Dendrophagella, Macrohyliota, Megahyliota, Microhyliota, Parahyliota, and Protodendrophagus. Aplatamus Grouvelle is removed from the Brontini and placed in the Telephanini. Four new species are described: Protodendrophagus antipodes Thomas; Brontoliota indivisipennis Thomas; Brontoliota intermedius Thomas; and Brontoliota monteithi Thomas. Described species are assigned to genera with the following new combinations resulting: Australodendrophagus australis (Erichson); Australohyliota chilensis (Blanchard); Australohyliota macleayi (Olliff); Denrophagella capito (Pascoe); Macrohyliota truncatipennis (Heller); Macrohyliota bicolor Arrow; Macrohyliotagracilicornis (Arrow); Macrohyliota lucius (Pascoe); Macrohyliota militaris (Erichson); Macrohyliota spinicollis (Gory); Megahyliota feae (Grouvelle); Microhyliota integricollis (Fairmaire); Parahyliota africanus Grouvelle; Parahyliota alticola (Pal, Sen Gupta, and Crowson); Parahyliota atratus (Grouvelle); Parahyliota brevicollis (Arrow); Parahyliota cinamomeus (Fairmaire); Parahyliota costicollis (Reitter); Parahyliota fallax (Grouvelle); Parahyliota indicus (Arrow); Parahyliota pallidus (Arrow); Parahyliota puberulus (Reitter); Parahyliota serratus (Smith); Parahyliota serricollis (Candeze); Parahyliota siamensis (Arrow). Two new synonymies are proposed: Uleiota crenicollis Grouvelle (=Uleiota costicollis Grouvelle) and Uleiota texana Dajoz (=Uleiota dubius (Fabricius)). Uleiota truncatus Motschulsky, formerly treated as a subspecies of U. dubius (Fabricius), is elevated to a full species, new status

    A review of New World Laemophloeus Dejean (Coleoptera: Laemophloeidae) : 1., species with antennal club of more than three antennomeres

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    Five Neotropical species of Laemophloeus Dejean (s. str.) (Coleoptera: Laemophloeidae) with antennal clubs of more than three antennomeres are reviewed: L. buenavista Thomas, n.sp.; L. concinnus Thomas, n.sp.; L. germaini Grouvelle; L. macrognathus Reitter; and L. sexarticulatus Kessel. Diagnoses, descriptions of the new species, illustrations, and a key are provided. Laemophloeus prominens Hetschko, proposed as a replacement name for Laemophloeus notabilis Kessel, is synonymized under L. germaini, new synonymy

    Theories that develop

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    The target article represents a significant advance in the level of sophistication applied to models of bilingual word recognition, and Dijkstra and van Heuven are to be congratulated on this endeavour. Bearing in mind the success of the (computational) BIA model in capturing detailed patterns of experimental data, I look forward to future simulation results from the BIA+ when the proposals of this new framework are implemented. It is an essential step to draw a distinction between recognition systems and the decision mechanisms that drive responses, and the authors have provided a novel way of apportioning empirical evidence of context effects in bilingual word recognition across this divide. Given the explanatory weight now being placed on decision mechanisms rather than the word recognition system itself, perhaps indeed it is now time to make some simplifying assumptions about the recognition system and start building detailed computational models of the decision component of the system. Implementation will provide the clarity of theorisation and evaluation of theory viability that have been the hallmark of the BIA model thus far
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